diff --git a/kernel/.gitignore b/kernel/.gitignore
index 0f0dba6..5518835 100644
--- a/kernel/.gitignore
+++ b/kernel/.gitignore
@@ -1,7 +1,5 @@
-#
+# SPDX-License-Identifier: GPL-2.0-only
 /config_data
-# Generated files
-#
 kheaders.md5
 timeconst.h
 hz.bc
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index e0852dc..3de8fd1 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -101,7 +101,7 @@
 # unlock and unlock_irq functions are inlined when:
 #   - DEBUG_SPINLOCK=n and ARCH_INLINE_*LOCK=y
 #  or
-#   - DEBUG_SPINLOCK=n and PREEMPT=n
+#   - DEBUG_SPINLOCK=n and PREEMPTION=n
 #
 # unlock_bh and unlock_irqrestore functions are inlined when:
 #   - DEBUG_SPINLOCK=n and ARCH_INLINE_*LOCK=y
@@ -139,7 +139,7 @@
 
 config INLINE_SPIN_UNLOCK_IRQ
 	def_bool y
-	depends on !PREEMPT || ARCH_INLINE_SPIN_UNLOCK_IRQ
+	depends on !PREEMPTION || ARCH_INLINE_SPIN_UNLOCK_IRQ
 
 config INLINE_SPIN_UNLOCK_IRQRESTORE
 	def_bool y
@@ -168,7 +168,7 @@
 
 config INLINE_READ_UNLOCK
 	def_bool y
-	depends on !PREEMPT || ARCH_INLINE_READ_UNLOCK
+	depends on !PREEMPTION || ARCH_INLINE_READ_UNLOCK
 
 config INLINE_READ_UNLOCK_BH
 	def_bool y
@@ -176,7 +176,7 @@
 
 config INLINE_READ_UNLOCK_IRQ
 	def_bool y
-	depends on !PREEMPT || ARCH_INLINE_READ_UNLOCK_IRQ
+	depends on !PREEMPTION || ARCH_INLINE_READ_UNLOCK_IRQ
 
 config INLINE_READ_UNLOCK_IRQRESTORE
 	def_bool y
@@ -205,7 +205,7 @@
 
 config INLINE_WRITE_UNLOCK
 	def_bool y
-	depends on !PREEMPT || ARCH_INLINE_WRITE_UNLOCK
+	depends on !PREEMPTION || ARCH_INLINE_WRITE_UNLOCK
 
 config INLINE_WRITE_UNLOCK_BH
 	def_bool y
@@ -213,7 +213,7 @@
 
 config INLINE_WRITE_UNLOCK_IRQ
 	def_bool y
-	depends on !PREEMPT || ARCH_INLINE_WRITE_UNLOCK_IRQ
+	depends on !PREEMPTION || ARCH_INLINE_WRITE_UNLOCK_IRQ
 
 config INLINE_WRITE_UNLOCK_IRQRESTORE
 	def_bool y
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index deff972..bf82259 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -65,7 +65,7 @@
 	  preemptible priority-inheritance aware variants, enforcing
 	  interrupt threading and introducing mechanisms to break up long
 	  non-preemptible sections. This makes the kernel, except for very
-	  low level and critical code pathes (entry code, scheduler, low
+	  low level and critical code paths (entry code, scheduler, low
 	  level interrupt handling) fully preemptible and brings most
 	  execution contexts under scheduler control.
 
diff --git a/kernel/Makefile b/kernel/Makefile
index d038b0d..e7905bd 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -5,13 +5,14 @@
 
 obj-y     = fork.o exec_domain.o panic.o \
 	    cpu.o exit.o softirq.o resource.o \
-	    sysctl.o sysctl_binary.o capability.o ptrace.o user.o \
+	    sysctl.o capability.o ptrace.o user.o \
 	    signal.o sys.o umh.o workqueue.o pid.o task_work.o \
 	    extable.o params.o \
 	    kthread.o sys_ni.o nsproxy.o \
 	    notifier.o ksysfs.o cred.o reboot.o \
-	    async.o range.o smpboot.o ucount.o
+	    async.o range.o smpboot.o ucount.o regset.o
 
+obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o
 obj-$(CONFIG_MODULES) += kmod.o
 obj-$(CONFIG_MULTIUSER) += groups.o
 
@@ -23,17 +24,19 @@
 # Prevents flicker of uninteresting __do_softirq()/__local_bh_disable_ip()
 # in coverage traces.
 KCOV_INSTRUMENT_softirq.o := n
+# Avoid KCSAN instrumentation in softirq ("No shared variables, all the data
+# are CPU local" => assume no data races), to reduce overhead in interrupts.
+KCSAN_SANITIZE_softirq.o = n
 # These are called from save_stack_trace() on slub debug path,
 # and produce insane amounts of uninteresting coverage.
 KCOV_INSTRUMENT_module.o := n
 KCOV_INSTRUMENT_extable.o := n
+KCOV_INSTRUMENT_stacktrace.o := n
 # Don't self-instrument.
 KCOV_INSTRUMENT_kcov.o := n
 KASAN_SANITIZE_kcov.o := n
-CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-
-# cond_syscall is currently not LTO compatible
-CFLAGS_sys_ni.o = $(DISABLE_LTO)
+KCSAN_SANITIZE_kcov.o := n
+CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector
 
 obj-y += sched/
 obj-y += locking/
@@ -43,8 +46,9 @@
 obj-y += rcu/
 obj-y += livepatch/
 obj-y += dma/
+obj-y += entry/
 
-obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o
+obj-$(CONFIG_KCMP) += kcmp.o
 obj-$(CONFIG_FREEZER) += freezer.o
 obj-$(CONFIG_PROFILING) += profile.o
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
@@ -101,6 +105,9 @@
 obj-$(CONFIG_IRQ_WORK) += irq_work.o
 obj-$(CONFIG_CPU_PM) += cpu_pm.o
 obj-$(CONFIG_BPF) += bpf/
+obj-$(CONFIG_KCSAN) += kcsan/
+obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o
+obj-$(CONFIG_HAVE_STATIC_CALL_INLINE) += static_call.o
 
 obj-$(CONFIG_PERF_EVENTS) += events/
 
@@ -113,13 +120,18 @@
 
 obj-$(CONFIG_HAS_IOMEM) += iomem.o
 obj-$(CONFIG_RSEQ) += rseq.o
+obj-$(CONFIG_WATCH_QUEUE) += watch_queue.o
 
 obj-$(CONFIG_SYSCTL_KUNIT_TEST) += sysctl-test.o
 
+CFLAGS_stackleak.o += $(DISABLE_STACKLEAK_PLUGIN)
 obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o
 KASAN_SANITIZE_stackleak.o := n
+KCSAN_SANITIZE_stackleak.o := n
 KCOV_INSTRUMENT_stackleak.o := n
 
+obj-$(CONFIG_SCF_TORTURE_TEST) += scftorture.o
+
 $(obj)/configs.o: $(obj)/config_data.gz
 
 targets += config_data config_data.gz
diff --git a/kernel/acct.c b/kernel/acct.c
index 81f9831..f175df8 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -25,7 +25,7 @@
  *  Now we silently close acct_file on attempt to reopen. Cleaned sys_acct().
  *  XTerms and EMACS are manifestations of pure evil. 21/10/98, AV.
  *
- *  Fixed a nasty interaction with with sys_umount(). If the accointing
+ *  Fixed a nasty interaction with sys_umount(). If the accounting
  *  was suspeneded we failed to stop it on umount(). Messy.
  *  Another one: remount to readonly didn't stop accounting.
  *	Question: what should we do if we have CAP_SYS_ADMIN but not
@@ -40,7 +40,7 @@
  *  is one more bug... 10/11/98, AV.
  *
  *	Oh, fsck... Oopsable SMP race in do_process_acct() - we must hold
- * ->mmap_sem to walk the vma list of current->mm. Nasty, since it leaks
+ * ->mmap_lock to walk the vma list of current->mm. Nasty, since it leaks
  * a struct file opened for write. Fixed. 2/6/2000, AV.
  */
 
@@ -263,12 +263,12 @@
  * sys_acct - enable/disable process accounting
  * @name: file name for accounting records or NULL to shutdown accounting
  *
- * Returns 0 for success or negative errno values for failure.
- *
  * sys_acct() is the only system call needed to implement process
  * accounting. It takes the name of the file where accounting records
  * should be written. If the filename is NULL, accounting will be
  * shutdown.
+ *
+ * Returns: 0 for success or negative errno values for failure.
  */
 SYSCALL_DEFINE1(acct, const char __user *, name)
 {
@@ -416,6 +416,7 @@
 {
 	struct pacct_struct *pacct = &current->signal->pacct;
 	u64 elapsed, run_time;
+	time64_t btime;
 	struct tty_struct *tty;
 
 	/*
@@ -448,7 +449,8 @@
 	}
 #endif
 	do_div(elapsed, AHZ);
-	ac->ac_btime = get_seconds() - elapsed;
+	btime = ktime_get_real_seconds() - elapsed;
+	ac->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX);
 #if ACCT_VERSION==2
 	ac->ac_ahz = AHZ;
 #endif
@@ -539,13 +541,13 @@
 	if (group_dead && current->mm) {
 		struct vm_area_struct *vma;
 
-		down_read(&current->mm->mmap_sem);
+		mmap_read_lock(current->mm);
 		vma = current->mm->mmap;
 		while (vma) {
 			vsize += vma->vm_end - vma->vm_start;
 			vma = vma->vm_next;
 		}
-		up_read(&current->mm->mmap_sem);
+		mmap_read_unlock(current->mm);
 	}
 
 	spin_lock_irq(&current->sighand->siglock);
@@ -584,9 +586,7 @@
 }
 
 /**
- * acct_process
- *
- * handles process accounting for an exiting task
+ * acct_process - handles process accounting for an exiting task
  */
 void acct_process(void)
 {
diff --git a/kernel/async.c b/kernel/async.c
index 4f9c1d6..1746cd6 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -111,7 +111,7 @@
 	struct async_entry *entry =
 		container_of(work, struct async_entry, work);
 	unsigned long flags;
-	ktime_t uninitialized_var(calltime), delta, rettime;
+	ktime_t calltime, delta, rettime;
 
 	/* 1) run (and print duration) */
 	if (initcall_debug && system_state < SYSTEM_RUNNING) {
@@ -205,9 +205,6 @@
 	atomic_inc(&entry_count);
 	spin_unlock_irqrestore(&async_lock, flags);
 
-	/* mark that this task has queued an async job, used by module init */
-	current->flags |= PF_USED_ASYNC;
-
 	/* schedule for execution */
 	queue_work_node(node, system_unbound_wq, &entry->work);
 
@@ -287,7 +284,7 @@
  */
 void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *domain)
 {
-	ktime_t uninitialized_var(starttime), delta, endtime;
+	ktime_t starttime, delta, endtime;
 
 	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		pr_debug("async_waiting @ %i\n", task_pid_nr(current));
diff --git a/kernel/audit.c b/kernel/audit.c
index 05ae208..aeec86e 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -102,12 +102,13 @@
  * This struct is RCU protected; you must either hold the RCU lock for reading
  * or the associated spinlock for writing.
  */
-static struct auditd_connection {
+struct auditd_connection {
 	struct pid *pid;
 	u32 portid;
 	struct net *net;
 	struct rcu_head rcu;
-} *auditd_conn = NULL;
+};
+static struct auditd_connection __rcu *auditd_conn;
 static DEFINE_SPINLOCK(auditd_conn_lock);
 
 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
@@ -122,9 +123,9 @@
 static u32	audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
 
 /* The identity of the user shutting down the audit system. */
-kuid_t		audit_sig_uid = INVALID_UID;
-pid_t		audit_sig_pid = -1;
-u32		audit_sig_sid = 0;
+static kuid_t		audit_sig_uid = INVALID_UID;
+static pid_t		audit_sig_pid = -1;
+static u32		audit_sig_sid;
 
 /* Records can be lost in several ways:
    0) [suppressed in audit_alloc]
@@ -135,6 +136,11 @@
 */
 static atomic_t	audit_lost = ATOMIC_INIT(0);
 
+/* Monotonically increasing sum of time the kernel has spent
+ * waiting while the backlog limit is exceeded.
+ */
+static atomic_t audit_backlog_wait_time_actual = ATOMIC_INIT(0);
+
 /* Hash for inode-based rules */
 struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
 
@@ -535,20 +541,22 @@
 /**
  * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
  * @skb: audit record
+ * @error: error code (unused)
  *
  * Description:
  * This should only be used by the kauditd_thread when it fails to flush the
  * hold queue.
  */
-static void kauditd_rehold_skb(struct sk_buff *skb)
+static void kauditd_rehold_skb(struct sk_buff *skb, __always_unused int error)
 {
-	/* put the record back in the queue at the same place */
-	skb_queue_head(&audit_hold_queue, skb);
+	/* put the record back in the queue */
+	skb_queue_tail(&audit_hold_queue, skb);
 }
 
 /**
  * kauditd_hold_skb - Queue an audit record, waiting for auditd
  * @skb: audit record
+ * @error: error code
  *
  * Description:
  * Queue the audit record, waiting for an instance of auditd.  When this
@@ -558,19 +566,31 @@
  * and queue it, if we have room.  If we want to hold on to the record, but we
  * don't have room, record a record lost message.
  */
-static void kauditd_hold_skb(struct sk_buff *skb)
+static void kauditd_hold_skb(struct sk_buff *skb, int error)
 {
 	/* at this point it is uncertain if we will ever send this to auditd so
 	 * try to send the message via printk before we go any further */
 	kauditd_printk_skb(skb);
 
 	/* can we just silently drop the message? */
-	if (!audit_default) {
-		kfree_skb(skb);
-		return;
+	if (!audit_default)
+		goto drop;
+
+	/* the hold queue is only for when the daemon goes away completely,
+	 * not -EAGAIN failures; if we are in a -EAGAIN state requeue the
+	 * record on the retry queue unless it's full, in which case drop it
+	 */
+	if (error == -EAGAIN) {
+		if (!audit_backlog_limit ||
+		    skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
+			skb_queue_tail(&audit_retry_queue, skb);
+			return;
+		}
+		audit_log_lost("kauditd retry queue overflow");
+		goto drop;
 	}
 
-	/* if we have room, queue the message */
+	/* if we have room in the hold queue, queue the message */
 	if (!audit_backlog_limit ||
 	    skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
 		skb_queue_tail(&audit_hold_queue, skb);
@@ -579,24 +599,32 @@
 
 	/* we have no other options - drop the message */
 	audit_log_lost("kauditd hold queue overflow");
+drop:
 	kfree_skb(skb);
 }
 
 /**
  * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
  * @skb: audit record
+ * @error: error code (unused)
  *
  * Description:
  * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
  * but for some reason we are having problems sending it audit records so
  * queue the given record and attempt to resend.
  */
-static void kauditd_retry_skb(struct sk_buff *skb)
+static void kauditd_retry_skb(struct sk_buff *skb, __always_unused int error)
 {
-	/* NOTE: because records should only live in the retry queue for a
-	 * short period of time, before either being sent or moved to the hold
-	 * queue, we don't currently enforce a limit on this queue */
-	skb_queue_tail(&audit_retry_queue, skb);
+	if (!audit_backlog_limit ||
+	    skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
+		skb_queue_tail(&audit_retry_queue, skb);
+		return;
+	}
+
+	/* we have to drop the record, send it via printk as a last effort */
+	kauditd_printk_skb(skb);
+	audit_log_lost("kauditd retry queue overflow");
+	kfree_skb(skb);
 }
 
 /**
@@ -634,7 +662,7 @@
 	/* flush the retry queue to the hold queue, but don't touch the main
 	 * queue since we need to process that normally for multicast */
 	while ((skb = skb_dequeue(&audit_retry_queue)))
-		kauditd_hold_skb(skb);
+		kauditd_hold_skb(skb, -ECONNREFUSED);
 }
 
 /**
@@ -708,16 +736,18 @@
 			      struct sk_buff_head *queue,
 			      unsigned int retry_limit,
 			      void (*skb_hook)(struct sk_buff *skb),
-			      void (*err_hook)(struct sk_buff *skb))
+			      void (*err_hook)(struct sk_buff *skb, int error))
 {
 	int rc = 0;
-	struct sk_buff *skb;
-	static unsigned int failed = 0;
+	struct sk_buff *skb = NULL;
+	struct sk_buff *skb_tail;
+	unsigned int failed = 0;
 
 	/* NOTE: kauditd_thread takes care of all our locking, we just use
 	 *       the netlink info passed to us (e.g. sk and portid) */
 
-	while ((skb = skb_dequeue(queue))) {
+	skb_tail = skb_peek_tail(queue);
+	while ((skb != skb_tail) && (skb = skb_dequeue(queue))) {
 		/* call the skb_hook for each skb we touch */
 		if (skb_hook)
 			(*skb_hook)(skb);
@@ -725,36 +755,34 @@
 		/* can we send to anyone via unicast? */
 		if (!sk) {
 			if (err_hook)
-				(*err_hook)(skb);
+				(*err_hook)(skb, -ECONNREFUSED);
 			continue;
 		}
 
+retry:
 		/* grab an extra skb reference in case of error */
 		skb_get(skb);
 		rc = netlink_unicast(sk, skb, portid, 0);
 		if (rc < 0) {
-			/* fatal failure for our queue flush attempt? */
+			/* send failed - try a few times unless fatal error */
 			if (++failed >= retry_limit ||
 			    rc == -ECONNREFUSED || rc == -EPERM) {
-				/* yes - error processing for the queue */
 				sk = NULL;
 				if (err_hook)
-					(*err_hook)(skb);
-				if (!skb_hook)
-					goto out;
-				/* keep processing with the skb_hook */
+					(*err_hook)(skb, rc);
+				if (rc == -EAGAIN)
+					rc = 0;
+				/* continue to drain the queue */
 				continue;
 			} else
-				/* no - requeue to preserve ordering */
-				skb_queue_head(queue, skb);
+				goto retry;
 		} else {
-			/* it worked - drop the extra reference and continue */
+			/* skb sent - drop the extra reference and continue */
 			consume_skb(skb);
 			failed = 0;
 		}
 	}
 
-out:
 	return (rc >= 0 ? 0 : rc);
 }
 
@@ -830,7 +858,7 @@
 		rc = kauditd_send_queue(sk, portid,
 					&audit_hold_queue, UNICAST_RETRIES,
 					NULL, kauditd_rehold_skb);
-		if (ac && rc < 0) {
+		if (rc < 0) {
 			sk = NULL;
 			auditd_reset(ac);
 			goto main_queue;
@@ -840,7 +868,7 @@
 		rc = kauditd_send_queue(sk, portid,
 					&audit_retry_queue, UNICAST_RETRIES,
 					NULL, kauditd_hold_skb);
-		if (ac && rc < 0) {
+		if (rc < 0) {
 			sk = NULL;
 			auditd_reset(ac);
 			goto main_queue;
@@ -928,8 +956,7 @@
 	if (!reply)
 		return;
 
-	if (reply->skb)
-		kfree_skb(reply->skb);
+	kfree_skb(reply->skb);
 	if (reply->net)
 		put_net(reply->net);
 	kfree(reply);
@@ -1200,17 +1227,18 @@
 	case AUDIT_GET: {
 		struct audit_status	s;
 		memset(&s, 0, sizeof(s));
-		s.enabled		= audit_enabled;
-		s.failure		= audit_failure;
+		s.enabled		   = audit_enabled;
+		s.failure		   = audit_failure;
 		/* NOTE: use pid_vnr() so the PID is relative to the current
 		 *       namespace */
-		s.pid			= auditd_pid_vnr();
-		s.rate_limit		= audit_rate_limit;
-		s.backlog_limit		= audit_backlog_limit;
-		s.lost			= atomic_read(&audit_lost);
-		s.backlog		= skb_queue_len(&audit_queue);
-		s.feature_bitmap	= AUDIT_FEATURE_BITMAP_ALL;
-		s.backlog_wait_time	= audit_backlog_wait_time;
+		s.pid			   = auditd_pid_vnr();
+		s.rate_limit		   = audit_rate_limit;
+		s.backlog_limit		   = audit_backlog_limit;
+		s.lost			   = atomic_read(&audit_lost);
+		s.backlog		   = skb_queue_len(&audit_queue);
+		s.feature_bitmap	   = AUDIT_FEATURE_BITMAP_ALL;
+		s.backlog_wait_time	   = audit_backlog_wait_time;
+		s.backlog_wait_time_actual = atomic_read(&audit_backlog_wait_time_actual);
 		audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
 		break;
 	}
@@ -1314,6 +1342,12 @@
 			audit_log_config_change("lost", 0, lost, 1);
 			return lost;
 		}
+		if (s.mask == AUDIT_STATUS_BACKLOG_WAIT_TIME_ACTUAL) {
+			u32 actual = atomic_xchg(&audit_backlog_wait_time_actual, 0);
+
+			audit_log_config_change("backlog_wait_time_actual", 0, actual, 1);
+			return actual;
+		}
 		break;
 	}
 	case AUDIT_GET_FEATURE:
@@ -1530,22 +1564,76 @@
 		nlh = nlmsg_next(nlh, &len);
 	}
 	audit_ctl_unlock();
+
+	/* can't block with the ctrl lock, so penalize the sender now */
+	if (audit_backlog_limit &&
+	    (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
+		DECLARE_WAITQUEUE(wait, current);
+
+		/* wake kauditd to try and flush the queue */
+		wake_up_interruptible(&kauditd_wait);
+
+		add_wait_queue_exclusive(&audit_backlog_wait, &wait);
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(audit_backlog_wait_time);
+		remove_wait_queue(&audit_backlog_wait, &wait);
+	}
+}
+
+/* Log information about who is connecting to the audit multicast socket */
+static void audit_log_multicast(int group, const char *op, int err)
+{
+	const struct cred *cred;
+	struct tty_struct *tty;
+	char comm[sizeof(current->comm)];
+	struct audit_buffer *ab;
+
+	if (!audit_enabled)
+		return;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+	if (!ab)
+		return;
+
+	cred = current_cred();
+	tty = audit_get_tty();
+	audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
+			 task_pid_nr(current),
+			 from_kuid(&init_user_ns, cred->uid),
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 tty ? tty_name(tty) : "(none)",
+			 audit_get_sessionid(current));
+	audit_put_tty(tty);
+	audit_log_task_context(ab); /* subj= */
+	audit_log_format(ab, " comm=");
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));
+	audit_log_d_path_exe(ab, current->mm); /* exe= */
+	audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
+	audit_log_end(ab);
 }
 
 /* Run custom bind function on netlink socket group connect or bind requests. */
-static int audit_bind(struct net *net, int group)
+static int audit_multicast_bind(struct net *net, int group)
 {
-	if (!capable(CAP_AUDIT_READ))
-		return -EPERM;
+	int err = 0;
 
-	return 0;
+	if (!capable(CAP_AUDIT_READ))
+		err = -EPERM;
+	audit_log_multicast(group, "connect", err);
+	return err;
+}
+
+static void audit_multicast_unbind(struct net *net, int group)
+{
+	audit_log_multicast(group, "disconnect", 0);
 }
 
 static int __net_init audit_net_init(struct net *net)
 {
 	struct netlink_kernel_cfg cfg = {
 		.input	= audit_receive,
-		.bind	= audit_bind,
+		.bind	= audit_multicast_bind,
+		.unbind	= audit_multicast_unbind,
 		.flags	= NL_CFG_F_NONROOT_RECV,
 		.groups	= AUDIT_NLGRP_MAX,
 	};
@@ -1557,7 +1645,8 @@
 		audit_panic("cannot initialize netlink socket in namespace");
 		return -ENOMEM;
 	}
-	aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
+	/* limit the timeout in case auditd is blocked/stopped */
+	aunet->sk->sk_sndtimeo = HZ / 10;
 
 	return 0;
 }
@@ -1759,7 +1848,7 @@
 {
 	struct audit_buffer *ab;
 	struct timespec64 t;
-	unsigned int uninitialized_var(serial);
+	unsigned int serial;
 
 	if (audit_initialized != AUDIT_INITIALIZED)
 		return NULL;
@@ -1773,7 +1862,9 @@
 	 *    task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
 	 *    using a PID anchored in the caller's namespace
 	 * 2. generator holding the audit_cmd_mutex - we don't want to block
-	 *    while holding the mutex */
+	 *    while holding the mutex, although we do penalize the sender
+	 *    later in audit_receive() when it is safe to block
+	 */
 	if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
 		long stime = audit_backlog_wait_time;
 
@@ -1785,12 +1876,15 @@
 			/* sleep if we are allowed and we haven't exhausted our
 			 * backlog wait limit */
 			if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
+				long rtime = stime;
+
 				DECLARE_WAITQUEUE(wait, current);
 
 				add_wait_queue_exclusive(&audit_backlog_wait,
 							 &wait);
 				set_current_state(TASK_UNINTERRUPTIBLE);
-				stime = schedule_timeout(stime);
+				stime = schedule_timeout(rtime);
+				atomic_add(rtime - stime, &audit_backlog_wait_time_actual);
 				remove_wait_queue(&audit_backlog_wait, &wait);
 			} else {
 				if (audit_rate_check() && printk_ratelimit())
@@ -2038,13 +2132,13 @@
 	/* We will allow 11 spaces for ' (deleted)' to be appended */
 	pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
 	if (!pathname) {
-		audit_log_string(ab, "<no_memory>");
+		audit_log_format(ab, "\"<no_memory>\"");
 		return;
 	}
 	p = d_path(path, pathname, PATH_MAX+11);
 	if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
 		/* FIXME: can we save some information here? */
-		audit_log_string(ab, "<too_long>");
+		audit_log_format(ab, "\"<too_long>\"");
 	} else
 		audit_log_untrustedstring(ab, p);
 	kfree(pathname);
@@ -2168,18 +2262,19 @@
 EXPORT_SYMBOL(audit_log_task_info);
 
 /**
- * audit_log_link_denied - report a link restriction denial
- * @operation: specific link operation
+ * audit_log_path_denied - report a path restriction denial
+ * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc)
+ * @operation: specific operation name
  */
-void audit_log_link_denied(const char *operation)
+void audit_log_path_denied(int type, const char *operation)
 {
 	struct audit_buffer *ab;
 
 	if (!audit_enabled || audit_dummy_context())
 		return;
 
-	/* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK);
+	/* Generate log with subject, operation, outcome. */
+	ab = audit_log_start(audit_context(), GFP_KERNEL, type);
 	if (!ab)
 		return;
 	audit_log_format(ab, "op=%s", operation);
diff --git a/kernel/audit.h b/kernel/audit.h
index ddc2287..3b9c094 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -327,10 +327,6 @@
 
 extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
 
-extern pid_t audit_sig_pid;
-extern kuid_t audit_sig_uid;
-extern u32 audit_sig_sid;
-
 extern int audit_filter(int msgtype, unsigned int listtype);
 
 extern void audit_ctl_lock(void);
diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
index f0d2433..5b3f01d 100644
--- a/kernel/audit_fsnotify.c
+++ b/kernel/audit_fsnotify.c
@@ -36,7 +36,7 @@
 
 /* fsnotify events we care about. */
 #define AUDIT_FS_EVENTS (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\
-			 FS_MOVE_SELF | FS_EVENT_ON_CHILD)
+			 FS_MOVE_SELF)
 
 static void audit_fsnotify_mark_free(struct audit_fsnotify_mark *audit_mark)
 {
@@ -152,44 +152,31 @@
 }
 
 /* Update mark data in audit rules based on fsnotify events. */
-static int audit_mark_handle_event(struct fsnotify_group *group,
-				    struct inode *to_tell,
-				    u32 mask, const void *data, int data_type,
-				    const struct qstr *dname, u32 cookie,
-				    struct fsnotify_iter_info *iter_info)
+static int audit_mark_handle_event(struct fsnotify_mark *inode_mark, u32 mask,
+				   struct inode *inode, struct inode *dir,
+				   const struct qstr *dname, u32 cookie)
 {
-	struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);
 	struct audit_fsnotify_mark *audit_mark;
-	const struct inode *inode = NULL;
 
 	audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark);
 
-	BUG_ON(group != audit_fsnotify_group);
-
-	switch (data_type) {
-	case (FSNOTIFY_EVENT_PATH):
-		inode = ((const struct path *)data)->dentry->d_inode;
-		break;
-	case (FSNOTIFY_EVENT_INODE):
-		inode = (const struct inode *)data;
-		break;
-	default:
-		BUG();
+	if (WARN_ON_ONCE(inode_mark->group != audit_fsnotify_group) ||
+	    WARN_ON_ONCE(!inode))
 		return 0;
-	}
 
 	if (mask & (FS_CREATE|FS_MOVED_TO|FS_DELETE|FS_MOVED_FROM)) {
 		if (audit_compare_dname_path(dname, audit_mark->path, AUDIT_NAME_FULL))
 			return 0;
 		audit_update_mark(audit_mark, inode);
-	} else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF))
+	} else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF)) {
 		audit_autoremove_mark_rule(audit_mark);
+	}
 
 	return 0;
 }
 
 static const struct fsnotify_ops audit_mark_fsnotify_ops = {
-	.handle_event =	audit_mark_handle_event,
+	.handle_inode_event = audit_mark_handle_event,
 	.free_mark = audit_fsnotify_free_mark,
 };
 
diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 9dec631..3924120 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -188,11 +188,9 @@
 static struct audit_chunk *alloc_chunk(int count)
 {
 	struct audit_chunk *chunk;
-	size_t size;
 	int i;
 
-	size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
-	chunk = kzalloc(size, GFP_KERNEL);
+	chunk = kzalloc(struct_size(chunk, owners, count), GFP_KERNEL);
 	if (!chunk)
 		return NULL;
 
@@ -1037,11 +1035,9 @@
 		audit_schedule_prune();
 }
 
-static int audit_tree_handle_event(struct fsnotify_group *group,
-				   struct inode *to_tell,
-				   u32 mask, const void *data, int data_type,
-				   const struct qstr *file_name, u32 cookie,
-				   struct fsnotify_iter_info *iter_info)
+static int audit_tree_handle_event(struct fsnotify_mark *mark, u32 mask,
+				   struct inode *inode, struct inode *dir,
+				   const struct qstr *file_name, u32 cookie)
 {
 	return 0;
 }
@@ -1070,7 +1066,7 @@
 }
 
 static const struct fsnotify_ops audit_tree_ops = {
-	.handle_event = audit_tree_handle_event,
+	.handle_inode_event = audit_tree_handle_event,
 	.freeing_mark = audit_tree_freeing_mark,
 	.free_mark = audit_tree_destroy_watch,
 };
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 8a8fd73..2acf7ca 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -53,7 +53,7 @@
 
 /* fsnotify events we care about. */
 #define AUDIT_FS_WATCH (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\
-			FS_MOVE_SELF | FS_EVENT_ON_CHILD | FS_UNMOUNT)
+			FS_MOVE_SELF | FS_UNMOUNT)
 
 static void audit_free_parent(struct audit_parent *parent)
 {
@@ -464,32 +464,17 @@
 }
 
 /* Update watch data in audit rules based on fsnotify events. */
-static int audit_watch_handle_event(struct fsnotify_group *group,
-				    struct inode *to_tell,
-				    u32 mask, const void *data, int data_type,
-				    const struct qstr *dname, u32 cookie,
-				    struct fsnotify_iter_info *iter_info)
+static int audit_watch_handle_event(struct fsnotify_mark *inode_mark, u32 mask,
+				    struct inode *inode, struct inode *dir,
+				    const struct qstr *dname, u32 cookie)
 {
-	struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);
-	const struct inode *inode;
 	struct audit_parent *parent;
 
 	parent = container_of(inode_mark, struct audit_parent, mark);
 
-	BUG_ON(group != audit_watch_group);
-
-	switch (data_type) {
-	case (FSNOTIFY_EVENT_PATH):
-		inode = d_backing_inode(((const struct path *)data)->dentry);
-		break;
-	case (FSNOTIFY_EVENT_INODE):
-		inode = (const struct inode *)data;
-		break;
-	default:
-		BUG();
-		inode = NULL;
-		break;
-	}
+	if (WARN_ON_ONCE(inode_mark->group != audit_watch_group) ||
+	    WARN_ON_ONCE(!inode))
+		return 0;
 
 	if (mask & (FS_CREATE|FS_MOVED_TO) && inode)
 		audit_update_watch(parent, dname, inode->i_sb->s_dev, inode->i_ino, 0);
@@ -502,7 +487,7 @@
 }
 
 static const struct fsnotify_ops audit_watch_fsnotify_ops = {
-	.handle_event = 	audit_watch_handle_event,
+	.handle_inode_event =	audit_watch_handle_event,
 	.free_mark =		audit_watch_free_mark,
 };
 
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index a10e299..333b3bc 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -681,7 +681,7 @@
 				data->values[i] = AUDIT_UID_UNSET;
 				break;
 			}
-			/* fall through - if set */
+			fallthrough;	/* if set */
 		default:
 			data->values[i] = f->val;
 		}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4effe01..638f424 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -75,6 +75,7 @@
 #include <linux/uaccess.h>
 #include <linux/fsnotify_backend.h>
 #include <uapi/linux/limits.h>
+#include <uapi/linux/netfilter/nf_tables.h>
 
 #include "audit.h"
 
@@ -130,6 +131,34 @@
 	struct audit_chunk *c[31];
 };
 
+struct audit_nfcfgop_tab {
+	enum audit_nfcfgop	op;
+	const char		*s;
+};
+
+static const struct audit_nfcfgop_tab audit_nfcfgs[] = {
+	{ AUDIT_XT_OP_REGISTER,			"xt_register"		   },
+	{ AUDIT_XT_OP_REPLACE,			"xt_replace"		   },
+	{ AUDIT_XT_OP_UNREGISTER,		"xt_unregister"		   },
+	{ AUDIT_NFT_OP_TABLE_REGISTER,		"nft_register_table"	   },
+	{ AUDIT_NFT_OP_TABLE_UNREGISTER,	"nft_unregister_table"	   },
+	{ AUDIT_NFT_OP_CHAIN_REGISTER,		"nft_register_chain"	   },
+	{ AUDIT_NFT_OP_CHAIN_UNREGISTER,	"nft_unregister_chain"	   },
+	{ AUDIT_NFT_OP_RULE_REGISTER,		"nft_register_rule"	   },
+	{ AUDIT_NFT_OP_RULE_UNREGISTER,		"nft_unregister_rule"	   },
+	{ AUDIT_NFT_OP_SET_REGISTER,		"nft_register_set"	   },
+	{ AUDIT_NFT_OP_SET_UNREGISTER,		"nft_unregister_set"	   },
+	{ AUDIT_NFT_OP_SETELEM_REGISTER,	"nft_register_setelem"	   },
+	{ AUDIT_NFT_OP_SETELEM_UNREGISTER,	"nft_unregister_setelem"   },
+	{ AUDIT_NFT_OP_GEN_REGISTER,		"nft_register_gen"	   },
+	{ AUDIT_NFT_OP_OBJ_REGISTER,		"nft_register_obj"	   },
+	{ AUDIT_NFT_OP_OBJ_UNREGISTER,		"nft_unregister_obj"	   },
+	{ AUDIT_NFT_OP_OBJ_RESET,		"nft_reset_obj"		   },
+	{ AUDIT_NFT_OP_FLOWTABLE_REGISTER,	"nft_register_flowtable"   },
+	{ AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,	"nft_unregister_flowtable" },
+	{ AUDIT_NFT_OP_INVALID,			"nft_invalid"		   },
+};
+
 static int audit_match_perm(struct audit_context *ctx, int mask)
 {
 	unsigned n;
@@ -624,7 +653,7 @@
 			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
 			break;
 		case AUDIT_SADDR_FAM:
-			if (ctx->sockaddr)
+			if (ctx && ctx->sockaddr)
 				result = audit_comparator(ctx->sockaddr->ss_family,
 							  f->op, f->val);
 			break;
@@ -1865,6 +1894,20 @@
 	return NULL;
 }
 
+inline void _audit_getcwd(struct audit_context *context)
+{
+	if (!context->pwd.dentry)
+		get_fs_pwd(current->fs, &context->pwd);
+}
+
+void __audit_getcwd(void)
+{
+	struct audit_context *context = audit_context();
+
+	if (context->in_syscall)
+		_audit_getcwd(context);
+}
+
 /**
  * __audit_getname - add a name to the list
  * @name: name to add
@@ -1889,8 +1932,7 @@
 	name->aname = n;
 	name->refcnt++;
 
-	if (!context->pwd.dentry)
-		get_fs_pwd(current->fs, &context->pwd);
+	_audit_getcwd(context);
 }
 
 static inline int audit_copy_fcaps(struct audit_names *name,
@@ -2545,6 +2587,26 @@
 	audit_log_ntp_val(ad, "adjust",	AUDIT_NTP_ADJUST);
 }
 
+void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
+		       enum audit_nfcfgop op, gfp_t gfp)
+{
+	struct audit_buffer *ab;
+	char comm[sizeof(current->comm)];
+
+	ab = audit_log_start(audit_context(), gfp, AUDIT_NETFILTER_CFG);
+	if (!ab)
+		return;
+	audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
+			 name, af, nentries, audit_nfcfgs[op].s);
+
+	audit_log_format(ab, " pid=%u", task_pid_nr(current));
+	audit_log_task_context(ab); /* subj= */
+	audit_log_format(ab, " comm=");
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));
+	audit_log_end(ab);
+}
+EXPORT_SYMBOL_GPL(__audit_log_nfcfg);
+
 static void audit_log_task(struct audit_buffer *ab)
 {
 	kuid_t auid, uid;
diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c
index a2a97fa..370217d 100644
--- a/kernel/backtracetest.c
+++ b/kernel/backtracetest.c
@@ -29,7 +29,7 @@
 	complete(&backtrace_work);
 }
 
-static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);
+static DECLARE_TASKLET_OLD(backtrace_tasklet, &backtrace_test_irq_callback);
 
 static void backtrace_test_irq(void)
 {
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index b0d78bc..c1b9f71 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -6,18 +6,20 @@
 endif
 CFLAGS_core.o += $(call cc-disable-warning, override-init) $(cflags-nogcse-yy)
 
-obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o
+obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o map_iter.o task_iter.o prog_iter.o
 obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o
-obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o
+obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o
+obj-${CONFIG_BPF_LSM}	  += bpf_inode_storage.o
 obj-$(CONFIG_BPF_SYSCALL) += disasm.o
+obj-$(CONFIG_BPF_JIT) += trampoline.o
 obj-$(CONFIG_BPF_SYSCALL) += btf.o
+obj-$(CONFIG_BPF_JIT) += dispatcher.o
 ifeq ($(CONFIG_NET),y)
 obj-$(CONFIG_BPF_SYSCALL) += devmap.o
 obj-$(CONFIG_BPF_SYSCALL) += cpumap.o
-ifeq ($(CONFIG_XDP_SOCKETS),y)
-obj-$(CONFIG_BPF_SYSCALL) += xskmap.o
-endif
+obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o
 obj-$(CONFIG_BPF_SYSCALL) += offload.o
+obj-$(CONFIG_BPF_SYSCALL) += net_namespace.o
 endif
 ifeq ($(CONFIG_PERF_EVENTS),y)
 obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
@@ -29,3 +31,8 @@
 ifeq ($(CONFIG_SYSFS),y)
 obj-$(CONFIG_DEBUG_INFO_BTF) += sysfs_btf.o
 endif
+ifeq ($(CONFIG_BPF_JIT),y)
+obj-$(CONFIG_BPF_SYSCALL) += bpf_struct_ops.o
+obj-${CONFIG_BPF_LSM} += bpf_lsm.o
+endif
+obj-$(CONFIG_BPF_PRELOAD) += preload/
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 1c65ce0..36c68dc 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -10,11 +10,13 @@
 #include <linux/filter.h>
 #include <linux/perf_event.h>
 #include <uapi/linux/btf.h>
+#include <linux/rcupdate_trace.h>
 
 #include "map_in_map.h"
 
 #define ARRAY_CREATE_FLAG_MASK \
-	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
+	(BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
+	 BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)
 
 static void bpf_array_free_percpu(struct bpf_array *array)
 {
@@ -59,6 +61,14 @@
 	    (percpu && numa_node != NUMA_NO_NODE))
 		return -EINVAL;
 
+	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
+	    attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
+		return -EINVAL;
+
+	if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
+	    attr->map_flags & BPF_F_PRESERVE_ELEMS)
+		return -EINVAL;
+
 	if (attr->value_size > KMALLOC_MAX_SIZE)
 		/* if value_size is bigger, the user space won't be able to
 		 * access the elements.
@@ -73,7 +83,7 @@
 	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
 	int ret, numa_node = bpf_map_attr_numa_node(attr);
 	u32 elem_size, index_mask, max_entries;
-	bool unpriv = !capable(CAP_SYS_ADMIN);
+	bool bypass_spec_v1 = bpf_bypass_spec_v1();
 	u64 cost, array_size, mask64;
 	struct bpf_map_memory mem;
 	struct bpf_array *array;
@@ -91,7 +101,7 @@
 	mask64 -= 1;
 
 	index_mask = mask64;
-	if (unpriv) {
+	if (!bypass_spec_v1) {
 		/* round up array size to nearest power of 2,
 		 * since cpu will speculate within index_mask limits
 		 */
@@ -102,10 +112,19 @@
 	}
 
 	array_size = sizeof(*array);
-	if (percpu)
+	if (percpu) {
 		array_size += (u64) max_entries * sizeof(void *);
-	else
-		array_size += (u64) max_entries * elem_size;
+	} else {
+		/* rely on vmalloc() to return page-aligned memory and
+		 * ensure array->value is exactly page-aligned
+		 */
+		if (attr->map_flags & BPF_F_MMAPABLE) {
+			array_size = PAGE_ALIGN(array_size);
+			array_size += PAGE_ALIGN((u64) max_entries * elem_size);
+		} else {
+			array_size += (u64) max_entries * elem_size;
+		}
+	}
 
 	/* make sure there is no u32 overflow later in round_up() */
 	cost = array_size;
@@ -117,13 +136,26 @@
 		return ERR_PTR(ret);
 
 	/* allocate all map elements and zero-initialize them */
-	array = bpf_map_area_alloc(array_size, numa_node);
+	if (attr->map_flags & BPF_F_MMAPABLE) {
+		void *data;
+
+		/* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */
+		data = bpf_map_area_mmapable_alloc(array_size, numa_node);
+		if (!data) {
+			bpf_map_charge_finish(&mem);
+			return ERR_PTR(-ENOMEM);
+		}
+		array = data + PAGE_ALIGN(sizeof(struct bpf_array))
+			- offsetof(struct bpf_array, value);
+	} else {
+		array = bpf_map_area_alloc(array_size, numa_node);
+	}
 	if (!array) {
 		bpf_map_charge_finish(&mem);
 		return ERR_PTR(-ENOMEM);
 	}
 	array->index_mask = index_mask;
-	array->map.unpriv_array = unpriv;
+	array->map.bypass_spec_v1 = bypass_spec_v1;
 
 	/* copy mandatory map attributes */
 	bpf_map_init_from_attr(&array->map, attr);
@@ -182,7 +214,7 @@
 }
 
 /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
-static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
+static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
 {
 	struct bpf_array *array = container_of(map, struct bpf_array, map);
 	struct bpf_insn *insn = insn_buf;
@@ -191,9 +223,12 @@
 	const int map_ptr = BPF_REG_1;
 	const int index = BPF_REG_2;
 
+	if (map->map_flags & BPF_F_INNER_MAP)
+		return -EOPNOTSUPP;
+
 	*insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
 	*insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
-	if (map->unpriv_array) {
+	if (!map->bypass_spec_v1) {
 		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
 		*insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
 	} else {
@@ -350,22 +385,23 @@
 	return -EINVAL;
 }
 
+static void *array_map_vmalloc_addr(struct bpf_array *array)
+{
+	return (void *)round_down((unsigned long)array, PAGE_SIZE);
+}
+
 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */
 static void array_map_free(struct bpf_map *map)
 {
 	struct bpf_array *array = container_of(map, struct bpf_array, map);
 
-	/* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
-	 * so the programs (can be more than one that used this map) were
-	 * disconnected from events. Wait for outstanding programs to complete
-	 * and free the array
-	 */
-	synchronize_rcu();
-
 	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
 		bpf_array_free_percpu(array);
 
-	bpf_map_area_free(array);
+	if (array->map.map_flags & BPF_F_MMAPABLE)
+		bpf_map_area_free(array_map_vmalloc_addr(array));
+	else
+		bpf_map_area_free(array);
 }
 
 static void array_map_seq_show_elem(struct bpf_map *map, void *key,
@@ -444,7 +480,170 @@
 	return 0;
 }
 
+static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
+
+	if (!(map->map_flags & BPF_F_MMAPABLE))
+		return -EINVAL;
+
+	if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) >
+	    PAGE_ALIGN((u64)array->map.max_entries * array->elem_size))
+		return -EINVAL;
+
+	return remap_vmalloc_range(vma, array_map_vmalloc_addr(array),
+				   vma->vm_pgoff + pgoff);
+}
+
+static bool array_map_meta_equal(const struct bpf_map *meta0,
+				 const struct bpf_map *meta1)
+{
+	if (!bpf_map_meta_equal(meta0, meta1))
+		return false;
+	return meta0->map_flags & BPF_F_INNER_MAP ? true :
+	       meta0->max_entries == meta1->max_entries;
+}
+
+struct bpf_iter_seq_array_map_info {
+	struct bpf_map *map;
+	void *percpu_value_buf;
+	u32 index;
+};
+
+static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_array_map_info *info = seq->private;
+	struct bpf_map *map = info->map;
+	struct bpf_array *array;
+	u32 index;
+
+	if (info->index >= map->max_entries)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	array = container_of(map, struct bpf_array, map);
+	index = info->index & array->index_mask;
+	if (info->percpu_value_buf)
+	       return array->pptrs[index];
+	return array->value + array->elem_size * index;
+}
+
+static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_array_map_info *info = seq->private;
+	struct bpf_map *map = info->map;
+	struct bpf_array *array;
+	u32 index;
+
+	++*pos;
+	++info->index;
+	if (info->index >= map->max_entries)
+		return NULL;
+
+	array = container_of(map, struct bpf_array, map);
+	index = info->index & array->index_mask;
+	if (info->percpu_value_buf)
+	       return array->pptrs[index];
+	return array->value + array->elem_size * index;
+}
+
+static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
+{
+	struct bpf_iter_seq_array_map_info *info = seq->private;
+	struct bpf_iter__bpf_map_elem ctx = {};
+	struct bpf_map *map = info->map;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+	int off = 0, cpu = 0;
+	void __percpu **pptr;
+	u32 size;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, v == NULL);
+	if (!prog)
+		return 0;
+
+	ctx.meta = &meta;
+	ctx.map = info->map;
+	if (v) {
+		ctx.key = &info->index;
+
+		if (!info->percpu_value_buf) {
+			ctx.value = v;
+		} else {
+			pptr = v;
+			size = round_up(map->value_size, 8);
+			for_each_possible_cpu(cpu) {
+				bpf_long_memcpy(info->percpu_value_buf + off,
+						per_cpu_ptr(pptr, cpu),
+						size);
+				off += size;
+			}
+			ctx.value = info->percpu_value_buf;
+		}
+	}
+
+	return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int bpf_array_map_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_array_map_seq_show(seq, v);
+}
+
+static void bpf_array_map_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_array_map_seq_show(seq, NULL);
+}
+
+static int bpf_iter_init_array_map(void *priv_data,
+				   struct bpf_iter_aux_info *aux)
+{
+	struct bpf_iter_seq_array_map_info *seq_info = priv_data;
+	struct bpf_map *map = aux->map;
+	void *value_buf;
+	u32 buf_size;
+
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		buf_size = round_up(map->value_size, 8) * num_possible_cpus();
+		value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
+		if (!value_buf)
+			return -ENOMEM;
+
+		seq_info->percpu_value_buf = value_buf;
+	}
+
+	seq_info->map = map;
+	return 0;
+}
+
+static void bpf_iter_fini_array_map(void *priv_data)
+{
+	struct bpf_iter_seq_array_map_info *seq_info = priv_data;
+
+	kfree(seq_info->percpu_value_buf);
+}
+
+static const struct seq_operations bpf_array_map_seq_ops = {
+	.start	= bpf_array_map_seq_start,
+	.next	= bpf_array_map_seq_next,
+	.stop	= bpf_array_map_seq_stop,
+	.show	= bpf_array_map_seq_show,
+};
+
+static const struct bpf_iter_seq_info iter_seq_info = {
+	.seq_ops		= &bpf_array_map_seq_ops,
+	.init_seq_private	= bpf_iter_init_array_map,
+	.fini_seq_private	= bpf_iter_fini_array_map,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_array_map_info),
+};
+
+static int array_map_btf_id;
 const struct bpf_map_ops array_map_ops = {
+	.map_meta_equal = array_map_meta_equal,
 	.map_alloc_check = array_map_alloc_check,
 	.map_alloc = array_map_alloc,
 	.map_free = array_map_free,
@@ -455,11 +654,19 @@
 	.map_gen_lookup = array_map_gen_lookup,
 	.map_direct_value_addr = array_map_direct_value_addr,
 	.map_direct_value_meta = array_map_direct_value_meta,
+	.map_mmap = array_map_mmap,
 	.map_seq_show_elem = array_map_seq_show_elem,
 	.map_check_btf = array_map_check_btf,
+	.map_lookup_batch = generic_map_lookup_batch,
+	.map_update_batch = generic_map_update_batch,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &array_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
 };
 
+static int percpu_array_map_btf_id;
 const struct bpf_map_ops percpu_array_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = array_map_alloc_check,
 	.map_alloc = array_map_alloc,
 	.map_free = array_map_free,
@@ -469,6 +676,9 @@
 	.map_delete_elem = array_map_delete_elem,
 	.map_seq_show_elem = percpu_array_map_seq_show_elem,
 	.map_check_btf = array_map_check_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &percpu_array_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
 };
 
 static int fd_array_map_alloc_check(union bpf_attr *attr)
@@ -487,8 +697,6 @@
 	struct bpf_array *array = container_of(map, struct bpf_array, map);
 	int i;
 
-	synchronize_rcu();
-
 	/* make sure it's empty */
 	for (i = 0; i < array->map.max_entries; i++)
 		BUG_ON(array->ptrs[i] != NULL);
@@ -540,10 +748,17 @@
 	if (IS_ERR(new_ptr))
 		return PTR_ERR(new_ptr);
 
-	old_ptr = xchg(array->ptrs + index, new_ptr);
+	if (map->ops->map_poke_run) {
+		mutex_lock(&array->aux->poke_mutex);
+		old_ptr = xchg(array->ptrs + index, new_ptr);
+		map->ops->map_poke_run(map, index, old_ptr, new_ptr);
+		mutex_unlock(&array->aux->poke_mutex);
+	} else {
+		old_ptr = xchg(array->ptrs + index, new_ptr);
+	}
+
 	if (old_ptr)
 		map->ops->map_fd_put_ptr(old_ptr);
-
 	return 0;
 }
 
@@ -556,7 +771,15 @@
 	if (index >= array->map.max_entries)
 		return -E2BIG;
 
-	old_ptr = xchg(array->ptrs + index, NULL);
+	if (map->ops->map_poke_run) {
+		mutex_lock(&array->aux->poke_mutex);
+		old_ptr = xchg(array->ptrs + index, NULL);
+		map->ops->map_poke_run(map, index, old_ptr, NULL);
+		mutex_unlock(&array->aux->poke_mutex);
+	} else {
+		old_ptr = xchg(array->ptrs + index, NULL);
+	}
+
 	if (old_ptr) {
 		map->ops->map_fd_put_ptr(old_ptr);
 		return 0;
@@ -625,18 +848,234 @@
 	rcu_read_unlock();
 }
 
+struct prog_poke_elem {
+	struct list_head list;
+	struct bpf_prog_aux *aux;
+};
+
+static int prog_array_map_poke_track(struct bpf_map *map,
+				     struct bpf_prog_aux *prog_aux)
+{
+	struct prog_poke_elem *elem;
+	struct bpf_array_aux *aux;
+	int ret = 0;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	mutex_lock(&aux->poke_mutex);
+	list_for_each_entry(elem, &aux->poke_progs, list) {
+		if (elem->aux == prog_aux)
+			goto out;
+	}
+
+	elem = kmalloc(sizeof(*elem), GFP_KERNEL);
+	if (!elem) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	INIT_LIST_HEAD(&elem->list);
+	/* We must track the program's aux info at this point in time
+	 * since the program pointer itself may not be stable yet, see
+	 * also comment in prog_array_map_poke_run().
+	 */
+	elem->aux = prog_aux;
+
+	list_add_tail(&elem->list, &aux->poke_progs);
+out:
+	mutex_unlock(&aux->poke_mutex);
+	return ret;
+}
+
+static void prog_array_map_poke_untrack(struct bpf_map *map,
+					struct bpf_prog_aux *prog_aux)
+{
+	struct prog_poke_elem *elem, *tmp;
+	struct bpf_array_aux *aux;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	mutex_lock(&aux->poke_mutex);
+	list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
+		if (elem->aux == prog_aux) {
+			list_del_init(&elem->list);
+			kfree(elem);
+			break;
+		}
+	}
+	mutex_unlock(&aux->poke_mutex);
+}
+
+static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
+				    struct bpf_prog *old,
+				    struct bpf_prog *new)
+{
+	u8 *old_addr, *new_addr, *old_bypass_addr;
+	struct prog_poke_elem *elem;
+	struct bpf_array_aux *aux;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex));
+
+	list_for_each_entry(elem, &aux->poke_progs, list) {
+		struct bpf_jit_poke_descriptor *poke;
+		int i, ret;
+
+		for (i = 0; i < elem->aux->size_poke_tab; i++) {
+			poke = &elem->aux->poke_tab[i];
+
+			/* Few things to be aware of:
+			 *
+			 * 1) We can only ever access aux in this context, but
+			 *    not aux->prog since it might not be stable yet and
+			 *    there could be danger of use after free otherwise.
+			 * 2) Initially when we start tracking aux, the program
+			 *    is not JITed yet and also does not have a kallsyms
+			 *    entry. We skip these as poke->tailcall_target_stable
+			 *    is not active yet. The JIT will do the final fixup
+			 *    before setting it stable. The various
+			 *    poke->tailcall_target_stable are successively
+			 *    activated, so tail call updates can arrive from here
+			 *    while JIT is still finishing its final fixup for
+			 *    non-activated poke entries.
+			 * 3) On program teardown, the program's kallsym entry gets
+			 *    removed out of RCU callback, but we can only untrack
+			 *    from sleepable context, therefore bpf_arch_text_poke()
+			 *    might not see that this is in BPF text section and
+			 *    bails out with -EINVAL. As these are unreachable since
+			 *    RCU grace period already passed, we simply skip them.
+			 * 4) Also programs reaching refcount of zero while patching
+			 *    is in progress is okay since we're protected under
+			 *    poke_mutex and untrack the programs before the JIT
+			 *    buffer is freed. When we're still in the middle of
+			 *    patching and suddenly kallsyms entry of the program
+			 *    gets evicted, we just skip the rest which is fine due
+			 *    to point 3).
+			 * 5) Any other error happening below from bpf_arch_text_poke()
+			 *    is a unexpected bug.
+			 */
+			if (!READ_ONCE(poke->tailcall_target_stable))
+				continue;
+			if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
+				continue;
+			if (poke->tail_call.map != map ||
+			    poke->tail_call.key != key)
+				continue;
+
+			old_bypass_addr = old ? NULL : poke->bypass_addr;
+			old_addr = old ? (u8 *)old->bpf_func + poke->adj_off : NULL;
+			new_addr = new ? (u8 *)new->bpf_func + poke->adj_off : NULL;
+
+			if (new) {
+				ret = bpf_arch_text_poke(poke->tailcall_target,
+							 BPF_MOD_JUMP,
+							 old_addr, new_addr);
+				BUG_ON(ret < 0 && ret != -EINVAL);
+				if (!old) {
+					ret = bpf_arch_text_poke(poke->tailcall_bypass,
+								 BPF_MOD_JUMP,
+								 poke->bypass_addr,
+								 NULL);
+					BUG_ON(ret < 0 && ret != -EINVAL);
+				}
+			} else {
+				ret = bpf_arch_text_poke(poke->tailcall_bypass,
+							 BPF_MOD_JUMP,
+							 old_bypass_addr,
+							 poke->bypass_addr);
+				BUG_ON(ret < 0 && ret != -EINVAL);
+				/* let other CPUs finish the execution of program
+				 * so that it will not possible to expose them
+				 * to invalid nop, stack unwind, nop state
+				 */
+				if (!ret)
+					synchronize_rcu();
+				ret = bpf_arch_text_poke(poke->tailcall_target,
+							 BPF_MOD_JUMP,
+							 old_addr, NULL);
+				BUG_ON(ret < 0 && ret != -EINVAL);
+			}
+		}
+	}
+}
+
+static void prog_array_map_clear_deferred(struct work_struct *work)
+{
+	struct bpf_map *map = container_of(work, struct bpf_array_aux,
+					   work)->map;
+	bpf_fd_array_map_clear(map);
+	bpf_map_put(map);
+}
+
+static void prog_array_map_clear(struct bpf_map *map)
+{
+	struct bpf_array_aux *aux = container_of(map, struct bpf_array,
+						 map)->aux;
+	bpf_map_inc(map);
+	schedule_work(&aux->work);
+}
+
+static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_array_aux *aux;
+	struct bpf_map *map;
+
+	aux = kzalloc(sizeof(*aux), GFP_KERNEL);
+	if (!aux)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_WORK(&aux->work, prog_array_map_clear_deferred);
+	INIT_LIST_HEAD(&aux->poke_progs);
+	mutex_init(&aux->poke_mutex);
+	spin_lock_init(&aux->owner.lock);
+
+	map = array_map_alloc(attr);
+	if (IS_ERR(map)) {
+		kfree(aux);
+		return map;
+	}
+
+	container_of(map, struct bpf_array, map)->aux = aux;
+	aux->map = map;
+
+	return map;
+}
+
+static void prog_array_map_free(struct bpf_map *map)
+{
+	struct prog_poke_elem *elem, *tmp;
+	struct bpf_array_aux *aux;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
+		list_del_init(&elem->list);
+		kfree(elem);
+	}
+	kfree(aux);
+	fd_array_map_free(map);
+}
+
+/* prog_array->aux->{type,jited} is a runtime binding.
+ * Doing static check alone in the verifier is not enough.
+ * Thus, prog_array_map cannot be used as an inner_map
+ * and map_meta_equal is not implemented.
+ */
+static int prog_array_map_btf_id;
 const struct bpf_map_ops prog_array_map_ops = {
 	.map_alloc_check = fd_array_map_alloc_check,
-	.map_alloc = array_map_alloc,
-	.map_free = fd_array_map_free,
+	.map_alloc = prog_array_map_alloc,
+	.map_free = prog_array_map_free,
+	.map_poke_track = prog_array_map_poke_track,
+	.map_poke_untrack = prog_array_map_poke_untrack,
+	.map_poke_run = prog_array_map_poke_run,
 	.map_get_next_key = array_map_get_next_key,
 	.map_lookup_elem = fd_array_map_lookup_elem,
 	.map_delete_elem = fd_array_map_delete_elem,
 	.map_fd_get_ptr = prog_fd_array_get_ptr,
 	.map_fd_put_ptr = prog_fd_array_put_ptr,
 	.map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
-	.map_release_uref = bpf_fd_array_map_clear,
+	.map_release_uref = prog_array_map_clear,
 	.map_seq_show_elem = prog_array_map_seq_show_elem,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &prog_array_map_btf_id,
 };
 
 static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
@@ -706,6 +1145,9 @@
 	struct bpf_event_entry *ee;
 	int i;
 
+	if (map->map_flags & BPF_F_PRESERVE_ELEMS)
+		return;
+
 	rcu_read_lock();
 	for (i = 0; i < array->map.max_entries; i++) {
 		ee = READ_ONCE(array->ptrs[i]);
@@ -715,10 +1157,19 @@
 	rcu_read_unlock();
 }
 
+static void perf_event_fd_array_map_free(struct bpf_map *map)
+{
+	if (map->map_flags & BPF_F_PRESERVE_ELEMS)
+		bpf_fd_array_map_clear(map);
+	fd_array_map_free(map);
+}
+
+static int perf_event_array_map_btf_id;
 const struct bpf_map_ops perf_event_array_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = fd_array_map_alloc_check,
 	.map_alloc = array_map_alloc,
-	.map_free = fd_array_map_free,
+	.map_free = perf_event_fd_array_map_free,
 	.map_get_next_key = array_map_get_next_key,
 	.map_lookup_elem = fd_array_map_lookup_elem,
 	.map_delete_elem = fd_array_map_delete_elem,
@@ -726,6 +1177,8 @@
 	.map_fd_put_ptr = perf_event_fd_array_put_ptr,
 	.map_release = perf_event_fd_array_release,
 	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &perf_event_array_map_btf_id,
 };
 
 #ifdef CONFIG_CGROUPS
@@ -748,7 +1201,9 @@
 	fd_array_map_free(map);
 }
 
+static int cgroup_array_map_btf_id;
 const struct bpf_map_ops cgroup_array_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = fd_array_map_alloc_check,
 	.map_alloc = array_map_alloc,
 	.map_free = cgroup_fd_array_free,
@@ -758,6 +1213,8 @@
 	.map_fd_get_ptr = cgroup_fd_array_get_ptr,
 	.map_fd_put_ptr = cgroup_fd_array_put_ptr,
 	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &cgroup_array_map_btf_id,
 };
 #endif
 
@@ -800,7 +1257,7 @@
 	return READ_ONCE(*inner_map);
 }
 
-static u32 array_of_map_gen_lookup(struct bpf_map *map,
+static int array_of_map_gen_lookup(struct bpf_map *map,
 				   struct bpf_insn *insn_buf)
 {
 	struct bpf_array *array = container_of(map, struct bpf_array, map);
@@ -812,7 +1269,7 @@
 
 	*insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
 	*insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
-	if (map->unpriv_array) {
+	if (!map->bypass_spec_v1) {
 		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
 		*insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
 	} else {
@@ -831,6 +1288,7 @@
 	return insn - insn_buf;
 }
 
+static int array_of_maps_map_btf_id;
 const struct bpf_map_ops array_of_maps_map_ops = {
 	.map_alloc_check = fd_array_map_alloc_check,
 	.map_alloc = array_of_map_alloc,
@@ -843,4 +1301,6 @@
 	.map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
 	.map_gen_lookup = array_of_map_gen_lookup,
 	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &array_of_maps_map_btf_id,
 };
diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
new file mode 100644
index 0000000..a4ac48c
--- /dev/null
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Facebook
+ * Copyright 2020 Google LLC.
+ */
+
+#include <linux/rculist.h>
+#include <linux/list.h>
+#include <linux/hash.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/bpf.h>
+#include <linux/bpf_local_storage.h>
+#include <net/sock.h>
+#include <uapi/linux/sock_diag.h>
+#include <uapi/linux/btf.h>
+#include <linux/bpf_lsm.h>
+#include <linux/btf_ids.h>
+#include <linux/fdtable.h>
+
+DEFINE_BPF_STORAGE_CACHE(inode_cache);
+
+static struct bpf_local_storage __rcu **
+inode_storage_ptr(void *owner)
+{
+	struct inode *inode = owner;
+	struct bpf_storage_blob *bsb;
+
+	bsb = bpf_inode(inode);
+	if (!bsb)
+		return NULL;
+	return &bsb->storage;
+}
+
+static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode,
+							   struct bpf_map *map,
+							   bool cacheit_lockit)
+{
+	struct bpf_local_storage *inode_storage;
+	struct bpf_local_storage_map *smap;
+	struct bpf_storage_blob *bsb;
+
+	bsb = bpf_inode(inode);
+	if (!bsb)
+		return NULL;
+
+	inode_storage = rcu_dereference(bsb->storage);
+	if (!inode_storage)
+		return NULL;
+
+	smap = (struct bpf_local_storage_map *)map;
+	return bpf_local_storage_lookup(inode_storage, smap, cacheit_lockit);
+}
+
+void bpf_inode_storage_free(struct inode *inode)
+{
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage *local_storage;
+	bool free_inode_storage = false;
+	struct bpf_storage_blob *bsb;
+	struct hlist_node *n;
+
+	bsb = bpf_inode(inode);
+	if (!bsb)
+		return;
+
+	rcu_read_lock();
+
+	local_storage = rcu_dereference(bsb->storage);
+	if (!local_storage) {
+		rcu_read_unlock();
+		return;
+	}
+
+	/* Netiher the bpf_prog nor the bpf-map's syscall
+	 * could be modifying the local_storage->list now.
+	 * Thus, no elem can be added-to or deleted-from the
+	 * local_storage->list by the bpf_prog or by the bpf-map's syscall.
+	 *
+	 * It is racing with bpf_local_storage_map_free() alone
+	 * when unlinking elem from the local_storage->list and
+	 * the map's bucket->list.
+	 */
+	raw_spin_lock_bh(&local_storage->lock);
+	hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) {
+		/* Always unlink from map before unlinking from
+		 * local_storage.
+		 */
+		bpf_selem_unlink_map(selem);
+		free_inode_storage = bpf_selem_unlink_storage_nolock(
+			local_storage, selem, false);
+	}
+	raw_spin_unlock_bh(&local_storage->lock);
+	rcu_read_unlock();
+
+	/* free_inoode_storage should always be true as long as
+	 * local_storage->list was non-empty.
+	 */
+	if (free_inode_storage)
+		kfree_rcu(local_storage, rcu);
+}
+
+static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_local_storage_data *sdata;
+	struct file *f;
+	int fd;
+
+	fd = *(int *)key;
+	f = fget_raw(fd);
+	if (!f)
+		return ERR_PTR(-EBADF);
+
+	sdata = inode_storage_lookup(f->f_inode, map, true);
+	fput(f);
+	return sdata ? sdata->data : NULL;
+}
+
+static int bpf_fd_inode_storage_update_elem(struct bpf_map *map, void *key,
+					 void *value, u64 map_flags)
+{
+	struct bpf_local_storage_data *sdata;
+	struct file *f;
+	int fd;
+
+	fd = *(int *)key;
+	f = fget_raw(fd);
+	if (!f)
+		return -EBADF;
+	if (!inode_storage_ptr(f->f_inode)) {
+		fput(f);
+		return -EBADF;
+	}
+
+	sdata = bpf_local_storage_update(f->f_inode,
+					 (struct bpf_local_storage_map *)map,
+					 value, map_flags);
+	fput(f);
+	return PTR_ERR_OR_ZERO(sdata);
+}
+
+static int inode_storage_delete(struct inode *inode, struct bpf_map *map)
+{
+	struct bpf_local_storage_data *sdata;
+
+	sdata = inode_storage_lookup(inode, map, false);
+	if (!sdata)
+		return -ENOENT;
+
+	bpf_selem_unlink(SELEM(sdata));
+
+	return 0;
+}
+
+static int bpf_fd_inode_storage_delete_elem(struct bpf_map *map, void *key)
+{
+	struct file *f;
+	int fd, err;
+
+	fd = *(int *)key;
+	f = fget_raw(fd);
+	if (!f)
+		return -EBADF;
+
+	err = inode_storage_delete(f->f_inode, map);
+	fput(f);
+	return err;
+}
+
+BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,
+	   void *, value, u64, flags)
+{
+	struct bpf_local_storage_data *sdata;
+
+	if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))
+		return (unsigned long)NULL;
+
+	/* explicitly check that the inode_storage_ptr is not
+	 * NULL as inode_storage_lookup returns NULL in this case and
+	 * bpf_local_storage_update expects the owner to have a
+	 * valid storage pointer.
+	 */
+	if (!inode || !inode_storage_ptr(inode))
+		return (unsigned long)NULL;
+
+	sdata = inode_storage_lookup(inode, map, true);
+	if (sdata)
+		return (unsigned long)sdata->data;
+
+	/* This helper must only called from where the inode is gurranteed
+	 * to have a refcount and cannot be freed.
+	 */
+	if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) {
+		sdata = bpf_local_storage_update(
+			inode, (struct bpf_local_storage_map *)map, value,
+			BPF_NOEXIST);
+		return IS_ERR(sdata) ? (unsigned long)NULL :
+					     (unsigned long)sdata->data;
+	}
+
+	return (unsigned long)NULL;
+}
+
+BPF_CALL_2(bpf_inode_storage_delete,
+	   struct bpf_map *, map, struct inode *, inode)
+{
+	if (!inode)
+		return -EINVAL;
+
+	/* This helper must only called from where the inode is gurranteed
+	 * to have a refcount and cannot be freed.
+	 */
+	return inode_storage_delete(inode, map);
+}
+
+static int notsupp_get_next_key(struct bpf_map *map, void *key,
+				void *next_key)
+{
+	return -ENOTSUPP;
+}
+
+static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_local_storage_map *smap;
+
+	smap = bpf_local_storage_map_alloc(attr);
+	if (IS_ERR(smap))
+		return ERR_CAST(smap);
+
+	smap->cache_idx = bpf_local_storage_cache_idx_get(&inode_cache);
+	return &smap->map;
+}
+
+static void inode_storage_map_free(struct bpf_map *map)
+{
+	struct bpf_local_storage_map *smap;
+
+	smap = (struct bpf_local_storage_map *)map;
+	bpf_local_storage_cache_idx_free(&inode_cache, smap->cache_idx);
+	bpf_local_storage_map_free(smap);
+}
+
+static int inode_storage_map_btf_id;
+const struct bpf_map_ops inode_storage_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = bpf_local_storage_map_alloc_check,
+	.map_alloc = inode_storage_map_alloc,
+	.map_free = inode_storage_map_free,
+	.map_get_next_key = notsupp_get_next_key,
+	.map_lookup_elem = bpf_fd_inode_storage_lookup_elem,
+	.map_update_elem = bpf_fd_inode_storage_update_elem,
+	.map_delete_elem = bpf_fd_inode_storage_delete_elem,
+	.map_check_btf = bpf_local_storage_map_check_btf,
+	.map_btf_name = "bpf_local_storage_map",
+	.map_btf_id = &inode_storage_map_btf_id,
+	.map_owner_storage_ptr = inode_storage_ptr,
+};
+
+BTF_ID_LIST_SINGLE(bpf_inode_storage_btf_ids, struct, inode)
+
+const struct bpf_func_proto bpf_inode_storage_get_proto = {
+	.func		= bpf_inode_storage_get,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.arg2_btf_id	= &bpf_inode_storage_btf_ids[0],
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+const struct bpf_func_proto bpf_inode_storage_delete_proto = {
+	.func		= bpf_inode_storage_delete,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.arg2_btf_id	= &bpf_inode_storage_btf_ids[0],
+};
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
new file mode 100644
index 0000000..e8957e9
--- /dev/null
+++ b/kernel/bpf/bpf_iter.c
@@ -0,0 +1,663 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+
+#include <linux/fs.h>
+#include <linux/anon_inodes.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+
+struct bpf_iter_target_info {
+	struct list_head list;
+	const struct bpf_iter_reg *reg_info;
+	u32 btf_id;	/* cached value */
+};
+
+struct bpf_iter_link {
+	struct bpf_link link;
+	struct bpf_iter_aux_info aux;
+	struct bpf_iter_target_info *tinfo;
+};
+
+struct bpf_iter_priv_data {
+	struct bpf_iter_target_info *tinfo;
+	const struct bpf_iter_seq_info *seq_info;
+	struct bpf_prog *prog;
+	u64 session_id;
+	u64 seq_num;
+	bool done_stop;
+	u8 target_private[] __aligned(8);
+};
+
+static struct list_head targets = LIST_HEAD_INIT(targets);
+static DEFINE_MUTEX(targets_mutex);
+
+/* protect bpf_iter_link changes */
+static DEFINE_MUTEX(link_mutex);
+
+/* incremented on every opened seq_file */
+static atomic64_t session_id;
+
+static int prepare_seq_file(struct file *file, struct bpf_iter_link *link,
+			    const struct bpf_iter_seq_info *seq_info);
+
+static void bpf_iter_inc_seq_num(struct seq_file *seq)
+{
+	struct bpf_iter_priv_data *iter_priv;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+	iter_priv->seq_num++;
+}
+
+static void bpf_iter_dec_seq_num(struct seq_file *seq)
+{
+	struct bpf_iter_priv_data *iter_priv;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+	iter_priv->seq_num--;
+}
+
+static void bpf_iter_done_stop(struct seq_file *seq)
+{
+	struct bpf_iter_priv_data *iter_priv;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+	iter_priv->done_stop = true;
+}
+
+/* maximum visited objects before bailing out */
+#define MAX_ITER_OBJECTS	1000000
+
+/* bpf_seq_read, a customized and simpler version for bpf iterator.
+ * no_llseek is assumed for this file.
+ * The following are differences from seq_read():
+ *  . fixed buffer size (PAGE_SIZE)
+ *  . assuming no_llseek
+ *  . stop() may call bpf program, handling potential overflow there
+ */
+static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size,
+			    loff_t *ppos)
+{
+	struct seq_file *seq = file->private_data;
+	size_t n, offs, copied = 0;
+	int err = 0, num_objs = 0;
+	void *p;
+
+	mutex_lock(&seq->lock);
+
+	if (!seq->buf) {
+		seq->size = PAGE_SIZE << 3;
+		seq->buf = kvmalloc(seq->size, GFP_KERNEL);
+		if (!seq->buf) {
+			err = -ENOMEM;
+			goto done;
+		}
+	}
+
+	if (seq->count) {
+		n = min(seq->count, size);
+		err = copy_to_user(buf, seq->buf + seq->from, n);
+		if (err) {
+			err = -EFAULT;
+			goto done;
+		}
+		seq->count -= n;
+		seq->from += n;
+		copied = n;
+		goto done;
+	}
+
+	seq->from = 0;
+	p = seq->op->start(seq, &seq->index);
+	if (!p)
+		goto stop;
+	if (IS_ERR(p)) {
+		err = PTR_ERR(p);
+		seq->op->stop(seq, p);
+		seq->count = 0;
+		goto done;
+	}
+
+	err = seq->op->show(seq, p);
+	if (err > 0) {
+		/* object is skipped, decrease seq_num, so next
+		 * valid object can reuse the same seq_num.
+		 */
+		bpf_iter_dec_seq_num(seq);
+		seq->count = 0;
+	} else if (err < 0 || seq_has_overflowed(seq)) {
+		if (!err)
+			err = -E2BIG;
+		seq->op->stop(seq, p);
+		seq->count = 0;
+		goto done;
+	}
+
+	while (1) {
+		loff_t pos = seq->index;
+
+		num_objs++;
+		offs = seq->count;
+		p = seq->op->next(seq, p, &seq->index);
+		if (pos == seq->index) {
+			pr_info_ratelimited("buggy seq_file .next function %ps "
+				"did not updated position index\n",
+				seq->op->next);
+			seq->index++;
+		}
+
+		if (IS_ERR_OR_NULL(p))
+			break;
+
+		/* got a valid next object, increase seq_num */
+		bpf_iter_inc_seq_num(seq);
+
+		if (seq->count >= size)
+			break;
+
+		if (num_objs >= MAX_ITER_OBJECTS) {
+			if (offs == 0) {
+				err = -EAGAIN;
+				seq->op->stop(seq, p);
+				goto done;
+			}
+			break;
+		}
+
+		err = seq->op->show(seq, p);
+		if (err > 0) {
+			bpf_iter_dec_seq_num(seq);
+			seq->count = offs;
+		} else if (err < 0 || seq_has_overflowed(seq)) {
+			seq->count = offs;
+			if (offs == 0) {
+				if (!err)
+					err = -E2BIG;
+				seq->op->stop(seq, p);
+				goto done;
+			}
+			break;
+		}
+	}
+stop:
+	offs = seq->count;
+	/* bpf program called if !p */
+	seq->op->stop(seq, p);
+	if (!p) {
+		if (!seq_has_overflowed(seq)) {
+			bpf_iter_done_stop(seq);
+		} else {
+			seq->count = offs;
+			if (offs == 0) {
+				err = -E2BIG;
+				goto done;
+			}
+		}
+	}
+
+	n = min(seq->count, size);
+	err = copy_to_user(buf, seq->buf, n);
+	if (err) {
+		err = -EFAULT;
+		goto done;
+	}
+	copied = n;
+	seq->count -= n;
+	seq->from = n;
+done:
+	if (!copied)
+		copied = err;
+	else
+		*ppos += copied;
+	mutex_unlock(&seq->lock);
+	return copied;
+}
+
+static const struct bpf_iter_seq_info *
+__get_seq_info(struct bpf_iter_link *link)
+{
+	const struct bpf_iter_seq_info *seq_info;
+
+	if (link->aux.map) {
+		seq_info = link->aux.map->ops->iter_seq_info;
+		if (seq_info)
+			return seq_info;
+	}
+
+	return link->tinfo->reg_info->seq_info;
+}
+
+static int iter_open(struct inode *inode, struct file *file)
+{
+	struct bpf_iter_link *link = inode->i_private;
+
+	return prepare_seq_file(file, link, __get_seq_info(link));
+}
+
+static int iter_release(struct inode *inode, struct file *file)
+{
+	struct bpf_iter_priv_data *iter_priv;
+	struct seq_file *seq;
+
+	seq = file->private_data;
+	if (!seq)
+		return 0;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+
+	if (iter_priv->seq_info->fini_seq_private)
+		iter_priv->seq_info->fini_seq_private(seq->private);
+
+	bpf_prog_put(iter_priv->prog);
+	seq->private = iter_priv;
+
+	return seq_release_private(inode, file);
+}
+
+const struct file_operations bpf_iter_fops = {
+	.open		= iter_open,
+	.llseek		= no_llseek,
+	.read		= bpf_seq_read,
+	.release	= iter_release,
+};
+
+/* The argument reg_info will be cached in bpf_iter_target_info.
+ * The common practice is to declare target reg_info as
+ * a const static variable and passed as an argument to
+ * bpf_iter_reg_target().
+ */
+int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info)
+{
+	struct bpf_iter_target_info *tinfo;
+
+	tinfo = kzalloc(sizeof(*tinfo), GFP_KERNEL);
+	if (!tinfo)
+		return -ENOMEM;
+
+	tinfo->reg_info = reg_info;
+	INIT_LIST_HEAD(&tinfo->list);
+
+	mutex_lock(&targets_mutex);
+	list_add(&tinfo->list, &targets);
+	mutex_unlock(&targets_mutex);
+
+	return 0;
+}
+
+void bpf_iter_unreg_target(const struct bpf_iter_reg *reg_info)
+{
+	struct bpf_iter_target_info *tinfo;
+	bool found = false;
+
+	mutex_lock(&targets_mutex);
+	list_for_each_entry(tinfo, &targets, list) {
+		if (reg_info == tinfo->reg_info) {
+			list_del(&tinfo->list);
+			kfree(tinfo);
+			found = true;
+			break;
+		}
+	}
+	mutex_unlock(&targets_mutex);
+
+	WARN_ON(found == false);
+}
+
+static void cache_btf_id(struct bpf_iter_target_info *tinfo,
+			 struct bpf_prog *prog)
+{
+	tinfo->btf_id = prog->aux->attach_btf_id;
+}
+
+bool bpf_iter_prog_supported(struct bpf_prog *prog)
+{
+	const char *attach_fname = prog->aux->attach_func_name;
+	u32 prog_btf_id = prog->aux->attach_btf_id;
+	const char *prefix = BPF_ITER_FUNC_PREFIX;
+	struct bpf_iter_target_info *tinfo;
+	int prefix_len = strlen(prefix);
+	bool supported = false;
+
+	if (strncmp(attach_fname, prefix, prefix_len))
+		return false;
+
+	mutex_lock(&targets_mutex);
+	list_for_each_entry(tinfo, &targets, list) {
+		if (tinfo->btf_id && tinfo->btf_id == prog_btf_id) {
+			supported = true;
+			break;
+		}
+		if (!strcmp(attach_fname + prefix_len, tinfo->reg_info->target)) {
+			cache_btf_id(tinfo, prog);
+			supported = true;
+			break;
+		}
+	}
+	mutex_unlock(&targets_mutex);
+
+	if (supported) {
+		prog->aux->ctx_arg_info_size = tinfo->reg_info->ctx_arg_info_size;
+		prog->aux->ctx_arg_info = tinfo->reg_info->ctx_arg_info;
+	}
+
+	return supported;
+}
+
+static void bpf_iter_link_release(struct bpf_link *link)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+
+	if (iter_link->tinfo->reg_info->detach_target)
+		iter_link->tinfo->reg_info->detach_target(&iter_link->aux);
+}
+
+static void bpf_iter_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+
+	kfree(iter_link);
+}
+
+static int bpf_iter_link_replace(struct bpf_link *link,
+				 struct bpf_prog *new_prog,
+				 struct bpf_prog *old_prog)
+{
+	int ret = 0;
+
+	mutex_lock(&link_mutex);
+	if (old_prog && link->prog != old_prog) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+
+	if (link->prog->type != new_prog->type ||
+	    link->prog->expected_attach_type != new_prog->expected_attach_type ||
+	    link->prog->aux->attach_btf_id != new_prog->aux->attach_btf_id) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	old_prog = xchg(&link->prog, new_prog);
+	bpf_prog_put(old_prog);
+
+out_unlock:
+	mutex_unlock(&link_mutex);
+	return ret;
+}
+
+static void bpf_iter_link_show_fdinfo(const struct bpf_link *link,
+				      struct seq_file *seq)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+	bpf_iter_show_fdinfo_t show_fdinfo;
+
+	seq_printf(seq,
+		   "target_name:\t%s\n",
+		   iter_link->tinfo->reg_info->target);
+
+	show_fdinfo = iter_link->tinfo->reg_info->show_fdinfo;
+	if (show_fdinfo)
+		show_fdinfo(&iter_link->aux, seq);
+}
+
+static int bpf_iter_link_fill_link_info(const struct bpf_link *link,
+					struct bpf_link_info *info)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+	char __user *ubuf = u64_to_user_ptr(info->iter.target_name);
+	bpf_iter_fill_link_info_t fill_link_info;
+	u32 ulen = info->iter.target_name_len;
+	const char *target_name;
+	u32 target_len;
+
+	if (!ulen ^ !ubuf)
+		return -EINVAL;
+
+	target_name = iter_link->tinfo->reg_info->target;
+	target_len =  strlen(target_name);
+	info->iter.target_name_len = target_len + 1;
+
+	if (ubuf) {
+		if (ulen >= target_len + 1) {
+			if (copy_to_user(ubuf, target_name, target_len + 1))
+				return -EFAULT;
+		} else {
+			char zero = '\0';
+
+			if (copy_to_user(ubuf, target_name, ulen - 1))
+				return -EFAULT;
+			if (put_user(zero, ubuf + ulen - 1))
+				return -EFAULT;
+			return -ENOSPC;
+		}
+	}
+
+	fill_link_info = iter_link->tinfo->reg_info->fill_link_info;
+	if (fill_link_info)
+		return fill_link_info(&iter_link->aux, info);
+
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_iter_link_lops = {
+	.release = bpf_iter_link_release,
+	.dealloc = bpf_iter_link_dealloc,
+	.update_prog = bpf_iter_link_replace,
+	.show_fdinfo = bpf_iter_link_show_fdinfo,
+	.fill_link_info = bpf_iter_link_fill_link_info,
+};
+
+bool bpf_link_is_iter(struct bpf_link *link)
+{
+	return link->ops == &bpf_iter_link_lops;
+}
+
+int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	union bpf_iter_link_info __user *ulinfo;
+	struct bpf_link_primer link_primer;
+	struct bpf_iter_target_info *tinfo;
+	union bpf_iter_link_info linfo;
+	struct bpf_iter_link *link;
+	u32 prog_btf_id, linfo_len;
+	bool existed = false;
+	int err;
+
+	if (attr->link_create.target_fd || attr->link_create.flags)
+		return -EINVAL;
+
+	memset(&linfo, 0, sizeof(union bpf_iter_link_info));
+
+	ulinfo = u64_to_user_ptr(attr->link_create.iter_info);
+	linfo_len = attr->link_create.iter_info_len;
+	if (!ulinfo ^ !linfo_len)
+		return -EINVAL;
+
+	if (ulinfo) {
+		err = bpf_check_uarg_tail_zero(ulinfo, sizeof(linfo),
+					       linfo_len);
+		if (err)
+			return err;
+		linfo_len = min_t(u32, linfo_len, sizeof(linfo));
+		if (copy_from_user(&linfo, ulinfo, linfo_len))
+			return -EFAULT;
+	}
+
+	prog_btf_id = prog->aux->attach_btf_id;
+	mutex_lock(&targets_mutex);
+	list_for_each_entry(tinfo, &targets, list) {
+		if (tinfo->btf_id == prog_btf_id) {
+			existed = true;
+			break;
+		}
+	}
+	mutex_unlock(&targets_mutex);
+	if (!existed)
+		return -ENOENT;
+
+	link = kzalloc(sizeof(*link), GFP_USER | __GFP_NOWARN);
+	if (!link)
+		return -ENOMEM;
+
+	bpf_link_init(&link->link, BPF_LINK_TYPE_ITER, &bpf_iter_link_lops, prog);
+	link->tinfo = tinfo;
+
+	err  = bpf_link_prime(&link->link, &link_primer);
+	if (err) {
+		kfree(link);
+		return err;
+	}
+
+	if (tinfo->reg_info->attach_target) {
+		err = tinfo->reg_info->attach_target(prog, &linfo, &link->aux);
+		if (err) {
+			bpf_link_cleanup(&link_primer);
+			return err;
+		}
+	}
+
+	return bpf_link_settle(&link_primer);
+}
+
+static void init_seq_meta(struct bpf_iter_priv_data *priv_data,
+			  struct bpf_iter_target_info *tinfo,
+			  const struct bpf_iter_seq_info *seq_info,
+			  struct bpf_prog *prog)
+{
+	priv_data->tinfo = tinfo;
+	priv_data->seq_info = seq_info;
+	priv_data->prog = prog;
+	priv_data->session_id = atomic64_inc_return(&session_id);
+	priv_data->seq_num = 0;
+	priv_data->done_stop = false;
+}
+
+static int prepare_seq_file(struct file *file, struct bpf_iter_link *link,
+			    const struct bpf_iter_seq_info *seq_info)
+{
+	struct bpf_iter_priv_data *priv_data;
+	struct bpf_iter_target_info *tinfo;
+	struct bpf_prog *prog;
+	u32 total_priv_dsize;
+	struct seq_file *seq;
+	int err = 0;
+
+	mutex_lock(&link_mutex);
+	prog = link->link.prog;
+	bpf_prog_inc(prog);
+	mutex_unlock(&link_mutex);
+
+	tinfo = link->tinfo;
+	total_priv_dsize = offsetof(struct bpf_iter_priv_data, target_private) +
+			   seq_info->seq_priv_size;
+	priv_data = __seq_open_private(file, seq_info->seq_ops,
+				       total_priv_dsize);
+	if (!priv_data) {
+		err = -ENOMEM;
+		goto release_prog;
+	}
+
+	if (seq_info->init_seq_private) {
+		err = seq_info->init_seq_private(priv_data->target_private, &link->aux);
+		if (err)
+			goto release_seq_file;
+	}
+
+	init_seq_meta(priv_data, tinfo, seq_info, prog);
+	seq = file->private_data;
+	seq->private = priv_data->target_private;
+
+	return 0;
+
+release_seq_file:
+	seq_release_private(file->f_inode, file);
+	file->private_data = NULL;
+release_prog:
+	bpf_prog_put(prog);
+	return err;
+}
+
+int bpf_iter_new_fd(struct bpf_link *link)
+{
+	struct bpf_iter_link *iter_link;
+	struct file *file;
+	unsigned int flags;
+	int err, fd;
+
+	if (link->ops != &bpf_iter_link_lops)
+		return -EINVAL;
+
+	flags = O_RDONLY | O_CLOEXEC;
+	fd = get_unused_fd_flags(flags);
+	if (fd < 0)
+		return fd;
+
+	file = anon_inode_getfile("bpf_iter", &bpf_iter_fops, NULL, flags);
+	if (IS_ERR(file)) {
+		err = PTR_ERR(file);
+		goto free_fd;
+	}
+
+	iter_link = container_of(link, struct bpf_iter_link, link);
+	err = prepare_seq_file(file, iter_link, __get_seq_info(iter_link));
+	if (err)
+		goto free_file;
+
+	fd_install(fd, file);
+	return fd;
+
+free_file:
+	fput(file);
+free_fd:
+	put_unused_fd(fd);
+	return err;
+}
+
+struct bpf_prog *bpf_iter_get_info(struct bpf_iter_meta *meta, bool in_stop)
+{
+	struct bpf_iter_priv_data *iter_priv;
+	struct seq_file *seq;
+	void *seq_priv;
+
+	seq = meta->seq;
+	if (seq->file->f_op != &bpf_iter_fops)
+		return NULL;
+
+	seq_priv = seq->private;
+	iter_priv = container_of(seq_priv, struct bpf_iter_priv_data,
+				 target_private);
+
+	if (in_stop && iter_priv->done_stop)
+		return NULL;
+
+	meta->session_id = iter_priv->session_id;
+	meta->seq_num = iter_priv->seq_num;
+
+	return iter_priv->prog;
+}
+
+int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx)
+{
+	int ret;
+
+	rcu_read_lock();
+	migrate_disable();
+	ret = BPF_PROG_RUN(prog, ctx);
+	migrate_enable();
+	rcu_read_unlock();
+
+	/* bpf program can only return 0 or 1:
+	 *  0 : okay
+	 *  1 : retry the same object
+	 * The bpf_iter_run_prog() return value
+	 * will be seq_ops->show() return value.
+	 */
+	return ret == 0 ? 0 : -EAGAIN;
+}
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
new file mode 100644
index 0000000..5d3a7af
--- /dev/null
+++ b/kernel/bpf/bpf_local_storage.c
@@ -0,0 +1,600 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook  */
+#include <linux/rculist.h>
+#include <linux/list.h>
+#include <linux/hash.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/bpf.h>
+#include <linux/btf_ids.h>
+#include <linux/bpf_local_storage.h>
+#include <net/sock.h>
+#include <uapi/linux/sock_diag.h>
+#include <uapi/linux/btf.h>
+
+#define BPF_LOCAL_STORAGE_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_CLONE)
+
+static struct bpf_local_storage_map_bucket *
+select_bucket(struct bpf_local_storage_map *smap,
+	      struct bpf_local_storage_elem *selem)
+{
+	return &smap->buckets[hash_ptr(selem, smap->bucket_log)];
+}
+
+static int mem_charge(struct bpf_local_storage_map *smap, void *owner, u32 size)
+{
+	struct bpf_map *map = &smap->map;
+
+	if (!map->ops->map_local_storage_charge)
+		return 0;
+
+	return map->ops->map_local_storage_charge(smap, owner, size);
+}
+
+static void mem_uncharge(struct bpf_local_storage_map *smap, void *owner,
+			 u32 size)
+{
+	struct bpf_map *map = &smap->map;
+
+	if (map->ops->map_local_storage_uncharge)
+		map->ops->map_local_storage_uncharge(smap, owner, size);
+}
+
+static struct bpf_local_storage __rcu **
+owner_storage(struct bpf_local_storage_map *smap, void *owner)
+{
+	struct bpf_map *map = &smap->map;
+
+	return map->ops->map_owner_storage_ptr(owner);
+}
+
+static bool selem_linked_to_storage(const struct bpf_local_storage_elem *selem)
+{
+	return !hlist_unhashed(&selem->snode);
+}
+
+static bool selem_linked_to_map(const struct bpf_local_storage_elem *selem)
+{
+	return !hlist_unhashed(&selem->map_node);
+}
+
+struct bpf_local_storage_elem *
+bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner,
+		void *value, bool charge_mem)
+{
+	struct bpf_local_storage_elem *selem;
+
+	if (charge_mem && mem_charge(smap, owner, smap->elem_size))
+		return NULL;
+
+	selem = kzalloc(smap->elem_size, GFP_ATOMIC | __GFP_NOWARN);
+	if (selem) {
+		if (value)
+			memcpy(SDATA(selem)->data, value, smap->map.value_size);
+		return selem;
+	}
+
+	if (charge_mem)
+		mem_uncharge(smap, owner, smap->elem_size);
+
+	return NULL;
+}
+
+/* local_storage->lock must be held and selem->local_storage == local_storage.
+ * The caller must ensure selem->smap is still valid to be
+ * dereferenced for its smap->elem_size and smap->cache_idx.
+ */
+bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_storage,
+				     struct bpf_local_storage_elem *selem,
+				     bool uncharge_mem)
+{
+	struct bpf_local_storage_map *smap;
+	bool free_local_storage;
+	void *owner;
+
+	smap = rcu_dereference(SDATA(selem)->smap);
+	owner = local_storage->owner;
+
+	/* All uncharging on the owner must be done first.
+	 * The owner may be freed once the last selem is unlinked
+	 * from local_storage.
+	 */
+	if (uncharge_mem)
+		mem_uncharge(smap, owner, smap->elem_size);
+
+	free_local_storage = hlist_is_singular_node(&selem->snode,
+						    &local_storage->list);
+	if (free_local_storage) {
+		mem_uncharge(smap, owner, sizeof(struct bpf_local_storage));
+		local_storage->owner = NULL;
+
+		/* After this RCU_INIT, owner may be freed and cannot be used */
+		RCU_INIT_POINTER(*owner_storage(smap, owner), NULL);
+
+		/* local_storage is not freed now.  local_storage->lock is
+		 * still held and raw_spin_unlock_bh(&local_storage->lock)
+		 * will be done by the caller.
+		 *
+		 * Although the unlock will be done under
+		 * rcu_read_lock(),  it is more intutivie to
+		 * read if kfree_rcu(local_storage, rcu) is done
+		 * after the raw_spin_unlock_bh(&local_storage->lock).
+		 *
+		 * Hence, a "bool free_local_storage" is returned
+		 * to the caller which then calls the kfree_rcu()
+		 * after unlock.
+		 */
+	}
+	hlist_del_init_rcu(&selem->snode);
+	if (rcu_access_pointer(local_storage->cache[smap->cache_idx]) ==
+	    SDATA(selem))
+		RCU_INIT_POINTER(local_storage->cache[smap->cache_idx], NULL);
+
+	kfree_rcu(selem, rcu);
+
+	return free_local_storage;
+}
+
+static void __bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem)
+{
+	struct bpf_local_storage *local_storage;
+	bool free_local_storage = false;
+
+	if (unlikely(!selem_linked_to_storage(selem)))
+		/* selem has already been unlinked from sk */
+		return;
+
+	local_storage = rcu_dereference(selem->local_storage);
+	raw_spin_lock_bh(&local_storage->lock);
+	if (likely(selem_linked_to_storage(selem)))
+		free_local_storage = bpf_selem_unlink_storage_nolock(
+			local_storage, selem, true);
+	raw_spin_unlock_bh(&local_storage->lock);
+
+	if (free_local_storage)
+		kfree_rcu(local_storage, rcu);
+}
+
+void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage,
+				   struct bpf_local_storage_elem *selem)
+{
+	RCU_INIT_POINTER(selem->local_storage, local_storage);
+	hlist_add_head_rcu(&selem->snode, &local_storage->list);
+}
+
+void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)
+{
+	struct bpf_local_storage_map *smap;
+	struct bpf_local_storage_map_bucket *b;
+
+	if (unlikely(!selem_linked_to_map(selem)))
+		/* selem has already be unlinked from smap */
+		return;
+
+	smap = rcu_dereference(SDATA(selem)->smap);
+	b = select_bucket(smap, selem);
+	raw_spin_lock_bh(&b->lock);
+	if (likely(selem_linked_to_map(selem)))
+		hlist_del_init_rcu(&selem->map_node);
+	raw_spin_unlock_bh(&b->lock);
+}
+
+void bpf_selem_link_map(struct bpf_local_storage_map *smap,
+			struct bpf_local_storage_elem *selem)
+{
+	struct bpf_local_storage_map_bucket *b = select_bucket(smap, selem);
+
+	raw_spin_lock_bh(&b->lock);
+	RCU_INIT_POINTER(SDATA(selem)->smap, smap);
+	hlist_add_head_rcu(&selem->map_node, &b->list);
+	raw_spin_unlock_bh(&b->lock);
+}
+
+void bpf_selem_unlink(struct bpf_local_storage_elem *selem)
+{
+	/* Always unlink from map before unlinking from local_storage
+	 * because selem will be freed after successfully unlinked from
+	 * the local_storage.
+	 */
+	bpf_selem_unlink_map(selem);
+	__bpf_selem_unlink_storage(selem);
+}
+
+struct bpf_local_storage_data *
+bpf_local_storage_lookup(struct bpf_local_storage *local_storage,
+			 struct bpf_local_storage_map *smap,
+			 bool cacheit_lockit)
+{
+	struct bpf_local_storage_data *sdata;
+	struct bpf_local_storage_elem *selem;
+
+	/* Fast path (cache hit) */
+	sdata = rcu_dereference(local_storage->cache[smap->cache_idx]);
+	if (sdata && rcu_access_pointer(sdata->smap) == smap)
+		return sdata;
+
+	/* Slow path (cache miss) */
+	hlist_for_each_entry_rcu(selem, &local_storage->list, snode)
+		if (rcu_access_pointer(SDATA(selem)->smap) == smap)
+			break;
+
+	if (!selem)
+		return NULL;
+
+	sdata = SDATA(selem);
+	if (cacheit_lockit) {
+		/* spinlock is needed to avoid racing with the
+		 * parallel delete.  Otherwise, publishing an already
+		 * deleted sdata to the cache will become a use-after-free
+		 * problem in the next bpf_local_storage_lookup().
+		 */
+		raw_spin_lock_bh(&local_storage->lock);
+		if (selem_linked_to_storage(selem))
+			rcu_assign_pointer(local_storage->cache[smap->cache_idx],
+					   sdata);
+		raw_spin_unlock_bh(&local_storage->lock);
+	}
+
+	return sdata;
+}
+
+static int check_flags(const struct bpf_local_storage_data *old_sdata,
+		       u64 map_flags)
+{
+	if (old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST)
+		/* elem already exists */
+		return -EEXIST;
+
+	if (!old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_EXIST)
+		/* elem doesn't exist, cannot update it */
+		return -ENOENT;
+
+	return 0;
+}
+
+int bpf_local_storage_alloc(void *owner,
+			    struct bpf_local_storage_map *smap,
+			    struct bpf_local_storage_elem *first_selem)
+{
+	struct bpf_local_storage *prev_storage, *storage;
+	struct bpf_local_storage **owner_storage_ptr;
+	int err;
+
+	err = mem_charge(smap, owner, sizeof(*storage));
+	if (err)
+		return err;
+
+	storage = kzalloc(sizeof(*storage), GFP_ATOMIC | __GFP_NOWARN);
+	if (!storage) {
+		err = -ENOMEM;
+		goto uncharge;
+	}
+
+	INIT_HLIST_HEAD(&storage->list);
+	raw_spin_lock_init(&storage->lock);
+	storage->owner = owner;
+
+	bpf_selem_link_storage_nolock(storage, first_selem);
+	bpf_selem_link_map(smap, first_selem);
+
+	owner_storage_ptr =
+		(struct bpf_local_storage **)owner_storage(smap, owner);
+	/* Publish storage to the owner.
+	 * Instead of using any lock of the kernel object (i.e. owner),
+	 * cmpxchg will work with any kernel object regardless what
+	 * the running context is, bh, irq...etc.
+	 *
+	 * From now on, the owner->storage pointer (e.g. sk->sk_bpf_storage)
+	 * is protected by the storage->lock.  Hence, when freeing
+	 * the owner->storage, the storage->lock must be held before
+	 * setting owner->storage ptr to NULL.
+	 */
+	prev_storage = cmpxchg(owner_storage_ptr, NULL, storage);
+	if (unlikely(prev_storage)) {
+		bpf_selem_unlink_map(first_selem);
+		err = -EAGAIN;
+		goto uncharge;
+
+		/* Note that even first_selem was linked to smap's
+		 * bucket->list, first_selem can be freed immediately
+		 * (instead of kfree_rcu) because
+		 * bpf_local_storage_map_free() does a
+		 * synchronize_rcu() before walking the bucket->list.
+		 * Hence, no one is accessing selem from the
+		 * bucket->list under rcu_read_lock().
+		 */
+	}
+
+	return 0;
+
+uncharge:
+	kfree(storage);
+	mem_uncharge(smap, owner, sizeof(*storage));
+	return err;
+}
+
+/* sk cannot be going away because it is linking new elem
+ * to sk->sk_bpf_storage. (i.e. sk->sk_refcnt cannot be 0).
+ * Otherwise, it will become a leak (and other memory issues
+ * during map destruction).
+ */
+struct bpf_local_storage_data *
+bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
+			 void *value, u64 map_flags)
+{
+	struct bpf_local_storage_data *old_sdata = NULL;
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage *local_storage;
+	int err;
+
+	/* BPF_EXIST and BPF_NOEXIST cannot be both set */
+	if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST) ||
+	    /* BPF_F_LOCK can only be used in a value with spin_lock */
+	    unlikely((map_flags & BPF_F_LOCK) &&
+		     !map_value_has_spin_lock(&smap->map)))
+		return ERR_PTR(-EINVAL);
+
+	local_storage = rcu_dereference(*owner_storage(smap, owner));
+	if (!local_storage || hlist_empty(&local_storage->list)) {
+		/* Very first elem for the owner */
+		err = check_flags(NULL, map_flags);
+		if (err)
+			return ERR_PTR(err);
+
+		selem = bpf_selem_alloc(smap, owner, value, true);
+		if (!selem)
+			return ERR_PTR(-ENOMEM);
+
+		err = bpf_local_storage_alloc(owner, smap, selem);
+		if (err) {
+			kfree(selem);
+			mem_uncharge(smap, owner, smap->elem_size);
+			return ERR_PTR(err);
+		}
+
+		return SDATA(selem);
+	}
+
+	if ((map_flags & BPF_F_LOCK) && !(map_flags & BPF_NOEXIST)) {
+		/* Hoping to find an old_sdata to do inline update
+		 * such that it can avoid taking the local_storage->lock
+		 * and changing the lists.
+		 */
+		old_sdata =
+			bpf_local_storage_lookup(local_storage, smap, false);
+		err = check_flags(old_sdata, map_flags);
+		if (err)
+			return ERR_PTR(err);
+		if (old_sdata && selem_linked_to_storage(SELEM(old_sdata))) {
+			copy_map_value_locked(&smap->map, old_sdata->data,
+					      value, false);
+			return old_sdata;
+		}
+	}
+
+	raw_spin_lock_bh(&local_storage->lock);
+
+	/* Recheck local_storage->list under local_storage->lock */
+	if (unlikely(hlist_empty(&local_storage->list))) {
+		/* A parallel del is happening and local_storage is going
+		 * away.  It has just been checked before, so very
+		 * unlikely.  Return instead of retry to keep things
+		 * simple.
+		 */
+		err = -EAGAIN;
+		goto unlock_err;
+	}
+
+	old_sdata = bpf_local_storage_lookup(local_storage, smap, false);
+	err = check_flags(old_sdata, map_flags);
+	if (err)
+		goto unlock_err;
+
+	if (old_sdata && (map_flags & BPF_F_LOCK)) {
+		copy_map_value_locked(&smap->map, old_sdata->data, value,
+				      false);
+		selem = SELEM(old_sdata);
+		goto unlock;
+	}
+
+	/* local_storage->lock is held.  Hence, we are sure
+	 * we can unlink and uncharge the old_sdata successfully
+	 * later.  Hence, instead of charging the new selem now
+	 * and then uncharge the old selem later (which may cause
+	 * a potential but unnecessary charge failure),  avoid taking
+	 * a charge at all here (the "!old_sdata" check) and the
+	 * old_sdata will not be uncharged later during
+	 * bpf_selem_unlink_storage_nolock().
+	 */
+	selem = bpf_selem_alloc(smap, owner, value, !old_sdata);
+	if (!selem) {
+		err = -ENOMEM;
+		goto unlock_err;
+	}
+
+	/* First, link the new selem to the map */
+	bpf_selem_link_map(smap, selem);
+
+	/* Second, link (and publish) the new selem to local_storage */
+	bpf_selem_link_storage_nolock(local_storage, selem);
+
+	/* Third, remove old selem, SELEM(old_sdata) */
+	if (old_sdata) {
+		bpf_selem_unlink_map(SELEM(old_sdata));
+		bpf_selem_unlink_storage_nolock(local_storage, SELEM(old_sdata),
+						false);
+	}
+
+unlock:
+	raw_spin_unlock_bh(&local_storage->lock);
+	return SDATA(selem);
+
+unlock_err:
+	raw_spin_unlock_bh(&local_storage->lock);
+	return ERR_PTR(err);
+}
+
+u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache)
+{
+	u64 min_usage = U64_MAX;
+	u16 i, res = 0;
+
+	spin_lock(&cache->idx_lock);
+
+	for (i = 0; i < BPF_LOCAL_STORAGE_CACHE_SIZE; i++) {
+		if (cache->idx_usage_counts[i] < min_usage) {
+			min_usage = cache->idx_usage_counts[i];
+			res = i;
+
+			/* Found a free cache_idx */
+			if (!min_usage)
+				break;
+		}
+	}
+	cache->idx_usage_counts[res]++;
+
+	spin_unlock(&cache->idx_lock);
+
+	return res;
+}
+
+void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache,
+				      u16 idx)
+{
+	spin_lock(&cache->idx_lock);
+	cache->idx_usage_counts[idx]--;
+	spin_unlock(&cache->idx_lock);
+}
+
+void bpf_local_storage_map_free(struct bpf_local_storage_map *smap)
+{
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage_map_bucket *b;
+	unsigned int i;
+
+	/* Note that this map might be concurrently cloned from
+	 * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone
+	 * RCU read section to finish before proceeding. New RCU
+	 * read sections should be prevented via bpf_map_inc_not_zero.
+	 */
+	synchronize_rcu();
+
+	/* bpf prog and the userspace can no longer access this map
+	 * now.  No new selem (of this map) can be added
+	 * to the owner->storage or to the map bucket's list.
+	 *
+	 * The elem of this map can be cleaned up here
+	 * or when the storage is freed e.g.
+	 * by bpf_sk_storage_free() during __sk_destruct().
+	 */
+	for (i = 0; i < (1U << smap->bucket_log); i++) {
+		b = &smap->buckets[i];
+
+		rcu_read_lock();
+		/* No one is adding to b->list now */
+		while ((selem = hlist_entry_safe(
+				rcu_dereference_raw(hlist_first_rcu(&b->list)),
+				struct bpf_local_storage_elem, map_node))) {
+			bpf_selem_unlink(selem);
+			cond_resched_rcu();
+		}
+		rcu_read_unlock();
+	}
+
+	/* While freeing the storage we may still need to access the map.
+	 *
+	 * e.g. when bpf_sk_storage_free() has unlinked selem from the map
+	 * which then made the above while((selem = ...)) loop
+	 * exit immediately.
+	 *
+	 * However, while freeing the storage one still needs to access the
+	 * smap->elem_size to do the uncharging in
+	 * bpf_selem_unlink_storage_nolock().
+	 *
+	 * Hence, wait another rcu grace period for the storage to be freed.
+	 */
+	synchronize_rcu();
+
+	kvfree(smap->buckets);
+	kfree(smap);
+}
+
+int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
+{
+	if (attr->map_flags & ~BPF_LOCAL_STORAGE_CREATE_FLAG_MASK ||
+	    !(attr->map_flags & BPF_F_NO_PREALLOC) ||
+	    attr->max_entries ||
+	    attr->key_size != sizeof(int) || !attr->value_size ||
+	    /* Enforce BTF for userspace sk dumping */
+	    !attr->btf_key_type_id || !attr->btf_value_type_id)
+		return -EINVAL;
+
+	if (!bpf_capable())
+		return -EPERM;
+
+	if (attr->value_size > BPF_LOCAL_STORAGE_MAX_VALUE_SIZE)
+		return -E2BIG;
+
+	return 0;
+}
+
+struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_local_storage_map *smap;
+	unsigned int i;
+	u32 nbuckets;
+	u64 cost;
+	int ret;
+
+	smap = kzalloc(sizeof(*smap), GFP_USER | __GFP_NOWARN);
+	if (!smap)
+		return ERR_PTR(-ENOMEM);
+	bpf_map_init_from_attr(&smap->map, attr);
+
+	nbuckets = roundup_pow_of_two(num_possible_cpus());
+	/* Use at least 2 buckets, select_bucket() is undefined behavior with 1 bucket */
+	nbuckets = max_t(u32, 2, nbuckets);
+	smap->bucket_log = ilog2(nbuckets);
+	cost = sizeof(*smap->buckets) * nbuckets + sizeof(*smap);
+
+	ret = bpf_map_charge_init(&smap->map.memory, cost);
+	if (ret < 0) {
+		kfree(smap);
+		return ERR_PTR(ret);
+	}
+
+	smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets,
+				 GFP_USER | __GFP_NOWARN);
+	if (!smap->buckets) {
+		bpf_map_charge_finish(&smap->map.memory);
+		kfree(smap);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	for (i = 0; i < nbuckets; i++) {
+		INIT_HLIST_HEAD(&smap->buckets[i].list);
+		raw_spin_lock_init(&smap->buckets[i].lock);
+	}
+
+	smap->elem_size =
+		sizeof(struct bpf_local_storage_elem) + attr->value_size;
+
+	return smap;
+}
+
+int bpf_local_storage_map_check_btf(const struct bpf_map *map,
+				    const struct btf *btf,
+				    const struct btf_type *key_type,
+				    const struct btf_type *value_type)
+{
+	u32 int_data;
+
+	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
+		return -EINVAL;
+
+	int_data = *(u32 *)(key_type + 1);
+	if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
+		return -EINVAL;
+
+	return 0;
+}
diff --git a/kernel/bpf/bpf_lru_list.h b/kernel/bpf/bpf_lru_list.h
index f025046..6b12f06 100644
--- a/kernel/bpf/bpf_lru_list.h
+++ b/kernel/bpf/bpf_lru_list.h
@@ -30,7 +30,7 @@
 struct bpf_lru_list {
 	struct list_head lists[NR_BPF_LRU_LIST_T];
 	unsigned int counts[NR_BPF_LRU_LIST_COUNT];
-	/* The next inacitve list rotation starts from here */
+	/* The next inactive list rotation starts from here */
 	struct list_head *next_inactive_rotation;
 
 	raw_spinlock_t lock ____cacheline_aligned_in_smp;
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
new file mode 100644
index 0000000..56cc5a9
--- /dev/null
+++ b/kernel/bpf/bpf_lsm.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2020 Google LLC.
+ */
+
+#include <linux/filter.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/lsm_hooks.h>
+#include <linux/bpf_lsm.h>
+#include <linux/kallsyms.h>
+#include <linux/bpf_verifier.h>
+#include <net/bpf_sk_storage.h>
+#include <linux/bpf_local_storage.h>
+#include <linux/btf_ids.h>
+
+/* For every LSM hook that allows attachment of BPF programs, declare a nop
+ * function where a BPF program can be attached.
+ */
+#define LSM_HOOK(RET, DEFAULT, NAME, ...)	\
+noinline RET bpf_lsm_##NAME(__VA_ARGS__)	\
+{						\
+	return DEFAULT;				\
+}
+
+#include <linux/lsm_hook_defs.h>
+#undef LSM_HOOK
+
+#define LSM_HOOK(RET, DEFAULT, NAME, ...) BTF_ID(func, bpf_lsm_##NAME)
+BTF_SET_START(bpf_lsm_hooks)
+#include <linux/lsm_hook_defs.h>
+#undef LSM_HOOK
+BTF_SET_END(bpf_lsm_hooks)
+
+int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog,
+			const struct bpf_prog *prog)
+{
+	if (!prog->gpl_compatible) {
+		bpf_log(vlog,
+			"LSM programs must have a GPL compatible license\n");
+		return -EINVAL;
+	}
+
+	if (!btf_id_set_contains(&bpf_lsm_hooks, prog->aux->attach_btf_id)) {
+		bpf_log(vlog, "attach_btf_id %u points to wrong type name %s\n",
+			prog->aux->attach_btf_id, prog->aux->attach_func_name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct bpf_func_proto *
+bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_inode_storage_get:
+		return &bpf_inode_storage_get_proto;
+	case BPF_FUNC_inode_storage_delete:
+		return &bpf_inode_storage_delete_proto;
+	case BPF_FUNC_sk_storage_get:
+		return &bpf_sk_storage_get_proto;
+	case BPF_FUNC_sk_storage_delete:
+		return &bpf_sk_storage_delete_proto;
+	default:
+		return tracing_prog_func_proto(func_id, prog);
+	}
+}
+
+const struct bpf_prog_ops lsm_prog_ops = {
+};
+
+const struct bpf_verifier_ops lsm_verifier_ops = {
+	.get_func_proto = bpf_lsm_func_proto,
+	.is_valid_access = btf_ctx_access,
+};
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
new file mode 100644
index 0000000..ac283f9
--- /dev/null
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -0,0 +1,653 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019 Facebook */
+
+#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/btf.h>
+#include <linux/filter.h>
+#include <linux/slab.h>
+#include <linux/numa.h>
+#include <linux/seq_file.h>
+#include <linux/refcount.h>
+#include <linux/mutex.h>
+
+enum bpf_struct_ops_state {
+	BPF_STRUCT_OPS_STATE_INIT,
+	BPF_STRUCT_OPS_STATE_INUSE,
+	BPF_STRUCT_OPS_STATE_TOBEFREE,
+};
+
+#define BPF_STRUCT_OPS_COMMON_VALUE			\
+	refcount_t refcnt;				\
+	enum bpf_struct_ops_state state
+
+struct bpf_struct_ops_value {
+	BPF_STRUCT_OPS_COMMON_VALUE;
+	char data[] ____cacheline_aligned_in_smp;
+};
+
+struct bpf_struct_ops_map {
+	struct bpf_map map;
+	const struct bpf_struct_ops *st_ops;
+	/* protect map_update */
+	struct mutex lock;
+	/* progs has all the bpf_prog that is populated
+	 * to the func ptr of the kernel's struct
+	 * (in kvalue.data).
+	 */
+	struct bpf_prog **progs;
+	/* image is a page that has all the trampolines
+	 * that stores the func args before calling the bpf_prog.
+	 * A PAGE_SIZE "image" is enough to store all trampoline for
+	 * "progs[]".
+	 */
+	void *image;
+	/* uvalue->data stores the kernel struct
+	 * (e.g. tcp_congestion_ops) that is more useful
+	 * to userspace than the kvalue.  For example,
+	 * the bpf_prog's id is stored instead of the kernel
+	 * address of a func ptr.
+	 */
+	struct bpf_struct_ops_value *uvalue;
+	/* kvalue.data stores the actual kernel's struct
+	 * (e.g. tcp_congestion_ops) that will be
+	 * registered to the kernel subsystem.
+	 */
+	struct bpf_struct_ops_value kvalue;
+};
+
+#define VALUE_PREFIX "bpf_struct_ops_"
+#define VALUE_PREFIX_LEN (sizeof(VALUE_PREFIX) - 1)
+
+/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is
+ * the map's value exposed to the userspace and its btf-type-id is
+ * stored at the map->btf_vmlinux_value_type_id.
+ *
+ */
+#define BPF_STRUCT_OPS_TYPE(_name)				\
+extern struct bpf_struct_ops bpf_##_name;			\
+								\
+struct bpf_struct_ops_##_name {						\
+	BPF_STRUCT_OPS_COMMON_VALUE;				\
+	struct _name data ____cacheline_aligned_in_smp;		\
+};
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+
+enum {
+#define BPF_STRUCT_OPS_TYPE(_name) BPF_STRUCT_OPS_TYPE_##_name,
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+	__NR_BPF_STRUCT_OPS_TYPE,
+};
+
+static struct bpf_struct_ops * const bpf_struct_ops[] = {
+#define BPF_STRUCT_OPS_TYPE(_name)				\
+	[BPF_STRUCT_OPS_TYPE_##_name] = &bpf_##_name,
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+};
+
+const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = {
+};
+
+const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
+};
+
+static const struct btf_type *module_type;
+
+void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
+{
+	s32 type_id, value_id, module_id;
+	const struct btf_member *member;
+	struct bpf_struct_ops *st_ops;
+	const struct btf_type *t;
+	char value_name[128];
+	const char *mname;
+	u32 i, j;
+
+	/* Ensure BTF type is emitted for "struct bpf_struct_ops_##_name" */
+#define BPF_STRUCT_OPS_TYPE(_name) BTF_TYPE_EMIT(struct bpf_struct_ops_##_name);
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+
+	module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);
+	if (module_id < 0) {
+		pr_warn("Cannot find struct module in btf_vmlinux\n");
+		return;
+	}
+	module_type = btf_type_by_id(btf, module_id);
+
+	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
+		st_ops = bpf_struct_ops[i];
+
+		if (strlen(st_ops->name) + VALUE_PREFIX_LEN >=
+		    sizeof(value_name)) {
+			pr_warn("struct_ops name %s is too long\n",
+				st_ops->name);
+			continue;
+		}
+		sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name);
+
+		value_id = btf_find_by_name_kind(btf, value_name,
+						 BTF_KIND_STRUCT);
+		if (value_id < 0) {
+			pr_warn("Cannot find struct %s in btf_vmlinux\n",
+				value_name);
+			continue;
+		}
+
+		type_id = btf_find_by_name_kind(btf, st_ops->name,
+						BTF_KIND_STRUCT);
+		if (type_id < 0) {
+			pr_warn("Cannot find struct %s in btf_vmlinux\n",
+				st_ops->name);
+			continue;
+		}
+		t = btf_type_by_id(btf, type_id);
+		if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) {
+			pr_warn("Cannot support #%u members in struct %s\n",
+				btf_type_vlen(t), st_ops->name);
+			continue;
+		}
+
+		for_each_member(j, t, member) {
+			const struct btf_type *func_proto;
+
+			mname = btf_name_by_offset(btf, member->name_off);
+			if (!*mname) {
+				pr_warn("anon member in struct %s is not supported\n",
+					st_ops->name);
+				break;
+			}
+
+			if (btf_member_bitfield_size(t, member)) {
+				pr_warn("bit field member %s in struct %s is not supported\n",
+					mname, st_ops->name);
+				break;
+			}
+
+			func_proto = btf_type_resolve_func_ptr(btf,
+							       member->type,
+							       NULL);
+			if (func_proto &&
+			    btf_distill_func_proto(log, btf,
+						   func_proto, mname,
+						   &st_ops->func_models[j])) {
+				pr_warn("Error in parsing func ptr %s in struct %s\n",
+					mname, st_ops->name);
+				break;
+			}
+		}
+
+		if (j == btf_type_vlen(t)) {
+			if (st_ops->init(btf)) {
+				pr_warn("Error in init bpf_struct_ops %s\n",
+					st_ops->name);
+			} else {
+				st_ops->type_id = type_id;
+				st_ops->type = t;
+				st_ops->value_id = value_id;
+				st_ops->value_type = btf_type_by_id(btf,
+								    value_id);
+			}
+		}
+	}
+}
+
+extern struct btf *btf_vmlinux;
+
+static const struct bpf_struct_ops *
+bpf_struct_ops_find_value(u32 value_id)
+{
+	unsigned int i;
+
+	if (!value_id || !btf_vmlinux)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
+		if (bpf_struct_ops[i]->value_id == value_id)
+			return bpf_struct_ops[i];
+	}
+
+	return NULL;
+}
+
+const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id)
+{
+	unsigned int i;
+
+	if (!type_id || !btf_vmlinux)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
+		if (bpf_struct_ops[i]->type_id == type_id)
+			return bpf_struct_ops[i];
+	}
+
+	return NULL;
+}
+
+static int bpf_struct_ops_map_get_next_key(struct bpf_map *map, void *key,
+					   void *next_key)
+{
+	if (key && *(u32 *)key == 0)
+		return -ENOENT;
+
+	*(u32 *)next_key = 0;
+	return 0;
+}
+
+int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key,
+				       void *value)
+{
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+	struct bpf_struct_ops_value *uvalue, *kvalue;
+	enum bpf_struct_ops_state state;
+
+	if (unlikely(*(u32 *)key != 0))
+		return -ENOENT;
+
+	kvalue = &st_map->kvalue;
+	/* Pair with smp_store_release() during map_update */
+	state = smp_load_acquire(&kvalue->state);
+	if (state == BPF_STRUCT_OPS_STATE_INIT) {
+		memset(value, 0, map->value_size);
+		return 0;
+	}
+
+	/* No lock is needed.  state and refcnt do not need
+	 * to be updated together under atomic context.
+	 */
+	uvalue = (struct bpf_struct_ops_value *)value;
+	memcpy(uvalue, st_map->uvalue, map->value_size);
+	uvalue->state = state;
+	refcount_set(&uvalue->refcnt, refcount_read(&kvalue->refcnt));
+
+	return 0;
+}
+
+static void *bpf_struct_ops_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static void bpf_struct_ops_map_put_progs(struct bpf_struct_ops_map *st_map)
+{
+	const struct btf_type *t = st_map->st_ops->type;
+	u32 i;
+
+	for (i = 0; i < btf_type_vlen(t); i++) {
+		if (st_map->progs[i]) {
+			bpf_prog_put(st_map->progs[i]);
+			st_map->progs[i] = NULL;
+		}
+	}
+}
+
+static int check_zero_holes(const struct btf_type *t, void *data)
+{
+	const struct btf_member *member;
+	u32 i, moff, msize, prev_mend = 0;
+	const struct btf_type *mtype;
+
+	for_each_member(i, t, member) {
+		moff = btf_member_bit_offset(t, member) / 8;
+		if (moff > prev_mend &&
+		    memchr_inv(data + prev_mend, 0, moff - prev_mend))
+			return -EINVAL;
+
+		mtype = btf_type_by_id(btf_vmlinux, member->type);
+		mtype = btf_resolve_size(btf_vmlinux, mtype, &msize);
+		if (IS_ERR(mtype))
+			return PTR_ERR(mtype);
+		prev_mend = moff + msize;
+	}
+
+	if (t->size > prev_mend &&
+	    memchr_inv(data + prev_mend, 0, t->size - prev_mend))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
+					  void *value, u64 flags)
+{
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+	const struct bpf_struct_ops *st_ops = st_map->st_ops;
+	struct bpf_struct_ops_value *uvalue, *kvalue;
+	const struct btf_member *member;
+	const struct btf_type *t = st_ops->type;
+	struct bpf_tramp_progs *tprogs = NULL;
+	void *udata, *kdata;
+	int prog_fd, err = 0;
+	void *image;
+	u32 i;
+
+	if (flags)
+		return -EINVAL;
+
+	if (*(u32 *)key != 0)
+		return -E2BIG;
+
+	err = check_zero_holes(st_ops->value_type, value);
+	if (err)
+		return err;
+
+	uvalue = (struct bpf_struct_ops_value *)value;
+	err = check_zero_holes(t, uvalue->data);
+	if (err)
+		return err;
+
+	if (uvalue->state || refcount_read(&uvalue->refcnt))
+		return -EINVAL;
+
+	tprogs = kcalloc(BPF_TRAMP_MAX, sizeof(*tprogs), GFP_KERNEL);
+	if (!tprogs)
+		return -ENOMEM;
+
+	uvalue = (struct bpf_struct_ops_value *)st_map->uvalue;
+	kvalue = (struct bpf_struct_ops_value *)&st_map->kvalue;
+
+	mutex_lock(&st_map->lock);
+
+	if (kvalue->state != BPF_STRUCT_OPS_STATE_INIT) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
+	memcpy(uvalue, value, map->value_size);
+
+	udata = &uvalue->data;
+	kdata = &kvalue->data;
+	image = st_map->image;
+
+	for_each_member(i, t, member) {
+		const struct btf_type *mtype, *ptype;
+		struct bpf_prog *prog;
+		u32 moff;
+		u32 flags;
+
+		moff = btf_member_bit_offset(t, member) / 8;
+		ptype = btf_type_resolve_ptr(btf_vmlinux, member->type, NULL);
+		if (ptype == module_type) {
+			if (*(void **)(udata + moff))
+				goto reset_unlock;
+			*(void **)(kdata + moff) = BPF_MODULE_OWNER;
+			continue;
+		}
+
+		err = st_ops->init_member(t, member, kdata, udata);
+		if (err < 0)
+			goto reset_unlock;
+
+		/* The ->init_member() has handled this member */
+		if (err > 0)
+			continue;
+
+		/* If st_ops->init_member does not handle it,
+		 * we will only handle func ptrs and zero-ed members
+		 * here.  Reject everything else.
+		 */
+
+		/* All non func ptr member must be 0 */
+		if (!ptype || !btf_type_is_func_proto(ptype)) {
+			u32 msize;
+
+			mtype = btf_type_by_id(btf_vmlinux, member->type);
+			mtype = btf_resolve_size(btf_vmlinux, mtype, &msize);
+			if (IS_ERR(mtype)) {
+				err = PTR_ERR(mtype);
+				goto reset_unlock;
+			}
+
+			if (memchr_inv(udata + moff, 0, msize)) {
+				err = -EINVAL;
+				goto reset_unlock;
+			}
+
+			continue;
+		}
+
+		prog_fd = (int)(*(unsigned long *)(udata + moff));
+		/* Similar check as the attr->attach_prog_fd */
+		if (!prog_fd)
+			continue;
+
+		prog = bpf_prog_get(prog_fd);
+		if (IS_ERR(prog)) {
+			err = PTR_ERR(prog);
+			goto reset_unlock;
+		}
+		st_map->progs[i] = prog;
+
+		if (prog->type != BPF_PROG_TYPE_STRUCT_OPS ||
+		    prog->aux->attach_btf_id != st_ops->type_id ||
+		    prog->expected_attach_type != i) {
+			err = -EINVAL;
+			goto reset_unlock;
+		}
+
+		tprogs[BPF_TRAMP_FENTRY].progs[0] = prog;
+		tprogs[BPF_TRAMP_FENTRY].nr_progs = 1;
+		flags = st_ops->func_models[i].ret_size > 0 ?
+			BPF_TRAMP_F_RET_FENTRY_RET : 0;
+		err = arch_prepare_bpf_trampoline(NULL, image,
+						  st_map->image + PAGE_SIZE,
+						  &st_ops->func_models[i],
+						  flags, tprogs, NULL);
+		if (err < 0)
+			goto reset_unlock;
+
+		*(void **)(kdata + moff) = image;
+		image += err;
+
+		/* put prog_id to udata */
+		*(unsigned long *)(udata + moff) = prog->aux->id;
+	}
+
+	refcount_set(&kvalue->refcnt, 1);
+	bpf_map_inc(map);
+
+	set_memory_ro((long)st_map->image, 1);
+	set_memory_x((long)st_map->image, 1);
+	err = st_ops->reg(kdata);
+	if (likely(!err)) {
+		/* Pair with smp_load_acquire() during lookup_elem().
+		 * It ensures the above udata updates (e.g. prog->aux->id)
+		 * can be seen once BPF_STRUCT_OPS_STATE_INUSE is set.
+		 */
+		smp_store_release(&kvalue->state, BPF_STRUCT_OPS_STATE_INUSE);
+		goto unlock;
+	}
+
+	/* Error during st_ops->reg().  It is very unlikely since
+	 * the above init_member() should have caught it earlier
+	 * before reg().  The only possibility is if there was a race
+	 * in registering the struct_ops (under the same name) to
+	 * a sub-system through different struct_ops's maps.
+	 */
+	set_memory_nx((long)st_map->image, 1);
+	set_memory_rw((long)st_map->image, 1);
+	bpf_map_put(map);
+
+reset_unlock:
+	bpf_struct_ops_map_put_progs(st_map);
+	memset(uvalue, 0, map->value_size);
+	memset(kvalue, 0, map->value_size);
+unlock:
+	kfree(tprogs);
+	mutex_unlock(&st_map->lock);
+	return err;
+}
+
+static int bpf_struct_ops_map_delete_elem(struct bpf_map *map, void *key)
+{
+	enum bpf_struct_ops_state prev_state;
+	struct bpf_struct_ops_map *st_map;
+
+	st_map = (struct bpf_struct_ops_map *)map;
+	prev_state = cmpxchg(&st_map->kvalue.state,
+			     BPF_STRUCT_OPS_STATE_INUSE,
+			     BPF_STRUCT_OPS_STATE_TOBEFREE);
+	switch (prev_state) {
+	case BPF_STRUCT_OPS_STATE_INUSE:
+		st_map->st_ops->unreg(&st_map->kvalue.data);
+		if (refcount_dec_and_test(&st_map->kvalue.refcnt))
+			bpf_map_put(map);
+		return 0;
+	case BPF_STRUCT_OPS_STATE_TOBEFREE:
+		return -EINPROGRESS;
+	case BPF_STRUCT_OPS_STATE_INIT:
+		return -ENOENT;
+	default:
+		WARN_ON_ONCE(1);
+		/* Should never happen.  Treat it as not found. */
+		return -ENOENT;
+	}
+}
+
+static void bpf_struct_ops_map_seq_show_elem(struct bpf_map *map, void *key,
+					     struct seq_file *m)
+{
+	void *value;
+	int err;
+
+	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
+	if (!value)
+		return;
+
+	err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
+	if (!err) {
+		btf_type_seq_show(btf_vmlinux, map->btf_vmlinux_value_type_id,
+				  value, m);
+		seq_puts(m, "\n");
+	}
+
+	kfree(value);
+}
+
+static void bpf_struct_ops_map_free(struct bpf_map *map)
+{
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+
+	if (st_map->progs)
+		bpf_struct_ops_map_put_progs(st_map);
+	bpf_map_area_free(st_map->progs);
+	bpf_jit_free_exec(st_map->image);
+	bpf_map_area_free(st_map->uvalue);
+	bpf_map_area_free(st_map);
+}
+
+static int bpf_struct_ops_map_alloc_check(union bpf_attr *attr)
+{
+	if (attr->key_size != sizeof(unsigned int) || attr->max_entries != 1 ||
+	    attr->map_flags || !attr->btf_vmlinux_value_type_id)
+		return -EINVAL;
+	return 0;
+}
+
+static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
+{
+	const struct bpf_struct_ops *st_ops;
+	size_t map_total_size, st_map_size;
+	struct bpf_struct_ops_map *st_map;
+	const struct btf_type *t, *vt;
+	struct bpf_map_memory mem;
+	struct bpf_map *map;
+	int err;
+
+	if (!bpf_capable())
+		return ERR_PTR(-EPERM);
+
+	st_ops = bpf_struct_ops_find_value(attr->btf_vmlinux_value_type_id);
+	if (!st_ops)
+		return ERR_PTR(-ENOTSUPP);
+
+	vt = st_ops->value_type;
+	if (attr->value_size != vt->size)
+		return ERR_PTR(-EINVAL);
+
+	t = st_ops->type;
+
+	st_map_size = sizeof(*st_map) +
+		/* kvalue stores the
+		 * struct bpf_struct_ops_tcp_congestions_ops
+		 */
+		(vt->size - sizeof(struct bpf_struct_ops_value));
+	map_total_size = st_map_size +
+		/* uvalue */
+		sizeof(vt->size) +
+		/* struct bpf_progs **progs */
+		 btf_type_vlen(t) * sizeof(struct bpf_prog *);
+	err = bpf_map_charge_init(&mem, map_total_size);
+	if (err < 0)
+		return ERR_PTR(err);
+
+	st_map = bpf_map_area_alloc(st_map_size, NUMA_NO_NODE);
+	if (!st_map) {
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+	st_map->st_ops = st_ops;
+	map = &st_map->map;
+
+	st_map->uvalue = bpf_map_area_alloc(vt->size, NUMA_NO_NODE);
+	st_map->progs =
+		bpf_map_area_alloc(btf_type_vlen(t) * sizeof(struct bpf_prog *),
+				   NUMA_NO_NODE);
+	st_map->image = bpf_jit_alloc_exec(PAGE_SIZE);
+	if (!st_map->uvalue || !st_map->progs || !st_map->image) {
+		bpf_struct_ops_map_free(map);
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	mutex_init(&st_map->lock);
+	set_vm_flush_reset_perms(st_map->image);
+	bpf_map_init_from_attr(map, attr);
+	bpf_map_charge_move(&map->memory, &mem);
+
+	return map;
+}
+
+static int bpf_struct_ops_map_btf_id;
+const struct bpf_map_ops bpf_struct_ops_map_ops = {
+	.map_alloc_check = bpf_struct_ops_map_alloc_check,
+	.map_alloc = bpf_struct_ops_map_alloc,
+	.map_free = bpf_struct_ops_map_free,
+	.map_get_next_key = bpf_struct_ops_map_get_next_key,
+	.map_lookup_elem = bpf_struct_ops_map_lookup_elem,
+	.map_delete_elem = bpf_struct_ops_map_delete_elem,
+	.map_update_elem = bpf_struct_ops_map_update_elem,
+	.map_seq_show_elem = bpf_struct_ops_map_seq_show_elem,
+	.map_btf_name = "bpf_struct_ops_map",
+	.map_btf_id = &bpf_struct_ops_map_btf_id,
+};
+
+/* "const void *" because some subsystem is
+ * passing a const (e.g. const struct tcp_congestion_ops *)
+ */
+bool bpf_struct_ops_get(const void *kdata)
+{
+	struct bpf_struct_ops_value *kvalue;
+
+	kvalue = container_of(kdata, struct bpf_struct_ops_value, data);
+
+	return refcount_inc_not_zero(&kvalue->refcnt);
+}
+
+void bpf_struct_ops_put(const void *kdata)
+{
+	struct bpf_struct_ops_value *kvalue;
+
+	kvalue = container_of(kdata, struct bpf_struct_ops_value, data);
+	if (refcount_dec_and_test(&kvalue->refcnt)) {
+		struct bpf_struct_ops_map *st_map;
+
+		st_map = container_of(kvalue, struct bpf_struct_ops_map,
+				      kvalue);
+		bpf_map_put(&st_map->map);
+	}
+}
diff --git a/kernel/bpf/bpf_struct_ops_types.h b/kernel/bpf/bpf_struct_ops_types.h
new file mode 100644
index 0000000..066d83e
--- /dev/null
+++ b/kernel/bpf/bpf_struct_ops_types.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* internal file - do not include directly */
+
+#ifdef CONFIG_BPF_JIT
+#ifdef CONFIG_INET
+#include <net/tcp.h>
+BPF_STRUCT_OPS_TYPE(tcp_congestion_ops)
+#endif
+#endif
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index b03087f..dc497ea 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2,6 +2,8 @@
 /* Copyright (c) 2018 Facebook */
 
 #include <uapi/linux/btf.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
 #include <uapi/linux/types.h>
 #include <linux/seq_file.h>
 #include <linux/compiler.h>
@@ -16,6 +18,12 @@
 #include <linux/sort.h>
 #include <linux/bpf_verifier.h>
 #include <linux/btf.h>
+#include <linux/btf_ids.h>
+#include <linux/skmsg.h>
+#include <linux/perf_event.h>
+#include <linux/bsearch.h>
+#include <linux/btf_ids.h>
+#include <net/sock.h>
 
 /* BTF (BPF Type Format) is the meta data format which describes
  * the data types of BPF program/map.  Hence, it basically focus
@@ -175,21 +183,11 @@
  */
 #define BTF_MAX_SIZE (16 * 1024 * 1024)
 
-#define for_each_member(i, struct_type, member)			\
-	for (i = 0, member = btf_type_member(struct_type);	\
-	     i < btf_type_vlen(struct_type);			\
-	     i++, member++)
-
 #define for_each_member_from(i, from, struct_type, member)		\
 	for (i = from, member = btf_type_member(struct_type) + from;	\
 	     i < btf_type_vlen(struct_type);				\
 	     i++, member++)
 
-#define for_each_vsi(i, struct_type, member)			\
-	for (i = 0, member = btf_type_var_secinfo(struct_type);	\
-	     i < btf_type_vlen(struct_type);			\
-	     i++, member++)
-
 #define for_each_vsi_from(i, from, struct_type, member)				\
 	for (i = from, member = btf_type_var_secinfo(struct_type) + from;	\
 	     i < btf_type_vlen(struct_type);					\
@@ -276,6 +274,96 @@
 	[BTF_KIND_DATASEC]	= "DATASEC",
 };
 
+static const char *btf_type_str(const struct btf_type *t)
+{
+	return btf_kind_str[BTF_INFO_KIND(t->info)];
+}
+
+/* Chunk size we use in safe copy of data to be shown. */
+#define BTF_SHOW_OBJ_SAFE_SIZE		32
+
+/*
+ * This is the maximum size of a base type value (equivalent to a
+ * 128-bit int); if we are at the end of our safe buffer and have
+ * less than 16 bytes space we can't be assured of being able
+ * to copy the next type safely, so in such cases we will initiate
+ * a new copy.
+ */
+#define BTF_SHOW_OBJ_BASE_TYPE_SIZE	16
+
+/* Type name size */
+#define BTF_SHOW_NAME_SIZE		80
+
+/*
+ * Common data to all BTF show operations. Private show functions can add
+ * their own data to a structure containing a struct btf_show and consult it
+ * in the show callback.  See btf_type_show() below.
+ *
+ * One challenge with showing nested data is we want to skip 0-valued
+ * data, but in order to figure out whether a nested object is all zeros
+ * we need to walk through it.  As a result, we need to make two passes
+ * when handling structs, unions and arrays; the first path simply looks
+ * for nonzero data, while the second actually does the display.  The first
+ * pass is signalled by show->state.depth_check being set, and if we
+ * encounter a non-zero value we set show->state.depth_to_show to
+ * the depth at which we encountered it.  When we have completed the
+ * first pass, we will know if anything needs to be displayed if
+ * depth_to_show > depth.  See btf_[struct,array]_show() for the
+ * implementation of this.
+ *
+ * Another problem is we want to ensure the data for display is safe to
+ * access.  To support this, the anonymous "struct {} obj" tracks the data
+ * object and our safe copy of it.  We copy portions of the data needed
+ * to the object "copy" buffer, but because its size is limited to
+ * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
+ * traverse larger objects for display.
+ *
+ * The various data type show functions all start with a call to
+ * btf_show_start_type() which returns a pointer to the safe copy
+ * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
+ * raw data itself).  btf_show_obj_safe() is responsible for
+ * using copy_from_kernel_nofault() to update the safe data if necessary
+ * as we traverse the object's data.  skbuff-like semantics are
+ * used:
+ *
+ * - obj.head points to the start of the toplevel object for display
+ * - obj.size is the size of the toplevel object
+ * - obj.data points to the current point in the original data at
+ *   which our safe data starts.  obj.data will advance as we copy
+ *   portions of the data.
+ *
+ * In most cases a single copy will suffice, but larger data structures
+ * such as "struct task_struct" will require many copies.  The logic in
+ * btf_show_obj_safe() handles the logic that determines if a new
+ * copy_from_kernel_nofault() is needed.
+ */
+struct btf_show {
+	u64 flags;
+	void *target;	/* target of show operation (seq file, buffer) */
+	void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
+	const struct btf *btf;
+	/* below are used during iteration */
+	struct {
+		u8 depth;
+		u8 depth_to_show;
+		u8 depth_check;
+		u8 array_member:1,
+		   array_terminated:1;
+		u16 array_encoding;
+		u32 type_id;
+		int status;			/* non-zero for error */
+		const struct btf_type *type;
+		const struct btf_member *member;
+		char name[BTF_SHOW_NAME_SIZE];	/* space for member name/type */
+	} state;
+	struct {
+		u32 size;
+		void *head;
+		void *data;
+		u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
+	} obj;
+};
+
 struct btf_kind_operations {
 	s32 (*check_meta)(struct btf_verifier_env *env,
 			  const struct btf_type *t,
@@ -292,9 +380,9 @@
 				  const struct btf_type *member_type);
 	void (*log_details)(struct btf_verifier_env *env,
 			    const struct btf_type *t);
-	void (*seq_show)(const struct btf *btf, const struct btf_type *t,
+	void (*show)(const struct btf *btf, const struct btf_type *t,
 			 u32 type_id, void *data, u8 bits_offsets,
-			 struct seq_file *m);
+			 struct btf_show *show);
 };
 
 static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
@@ -336,16 +424,6 @@
 	return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
 }
 
-static bool btf_type_is_func(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
-}
-
-static bool btf_type_is_func_proto(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
-}
-
 static bool btf_type_nosize(const struct btf_type *t)
 {
 	return btf_type_is_void(t) || btf_type_is_fwd(t) ||
@@ -357,16 +435,6 @@
 	return !t || btf_type_nosize(t);
 }
 
-/* union is only a special case of struct:
- * all its offsetof(member) == 0
- */
-static bool btf_type_is_struct(const struct btf_type *t)
-{
-	u8 kind = BTF_INFO_KIND(t->info);
-
-	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
-}
-
 static bool __btf_type_is_struct(const struct btf_type *t)
 {
 	return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
@@ -377,26 +445,70 @@
 	return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
 }
 
-static bool btf_type_is_ptr(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
-}
-
-static bool btf_type_is_int(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
-}
-
-static bool btf_type_is_var(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
-}
-
 static bool btf_type_is_datasec(const struct btf_type *t)
 {
 	return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
 }
 
+s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
+{
+	const struct btf_type *t;
+	const char *tname;
+	u32 i;
+
+	for (i = 1; i <= btf->nr_types; i++) {
+		t = btf->types[i];
+		if (BTF_INFO_KIND(t->info) != kind)
+			continue;
+
+		tname = btf_name_by_offset(btf, t->name_off);
+		if (!strcmp(tname, name))
+			return i;
+	}
+
+	return -ENOENT;
+}
+
+const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
+					       u32 id, u32 *res_id)
+{
+	const struct btf_type *t = btf_type_by_id(btf, id);
+
+	while (btf_type_is_modifier(t)) {
+		id = t->type;
+		t = btf_type_by_id(btf, t->type);
+	}
+
+	if (res_id)
+		*res_id = id;
+
+	return t;
+}
+
+const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
+					    u32 id, u32 *res_id)
+{
+	const struct btf_type *t;
+
+	t = btf_type_skip_modifiers(btf, id, NULL);
+	if (!btf_type_is_ptr(t))
+		return NULL;
+
+	return btf_type_skip_modifiers(btf, t->type, res_id);
+}
+
+const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
+						 u32 id, u32 *res_id)
+{
+	const struct btf_type *ptype;
+
+	ptype = btf_type_resolve_ptr(btf, id, res_id);
+	if (ptype && btf_type_is_func_proto(ptype))
+		return ptype;
+
+	return NULL;
+}
+
 /* Types that act only as a source, not sink or intermediate
  * type when resolving.
  */
@@ -461,30 +573,6 @@
 		return "UNKN";
 }
 
-static u16 btf_type_vlen(const struct btf_type *t)
-{
-	return BTF_INFO_VLEN(t->info);
-}
-
-static bool btf_type_kflag(const struct btf_type *t)
-{
-	return BTF_INFO_KFLAG(t->info);
-}
-
-static u32 btf_member_bit_offset(const struct btf_type *struct_type,
-			     const struct btf_member *member)
-{
-	return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
-					   : member->offset;
-}
-
-static u32 btf_member_bitfield_size(const struct btf_type *struct_type,
-				    const struct btf_member *member)
-{
-	return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
-					   : 0;
-}
-
 static u32 btf_type_int(const struct btf_type *t)
 {
 	return *(u32 *)(t + 1);
@@ -495,11 +583,6 @@
 	return (const struct btf_array *)(t + 1);
 }
 
-static const struct btf_member *btf_type_member(const struct btf_type *t)
-{
-	return (const struct btf_member *)(t + 1);
-}
-
 static const struct btf_enum *btf_type_enum(const struct btf_type *t)
 {
 	return (const struct btf_enum *)(t + 1);
@@ -510,11 +593,6 @@
 	return (const struct btf_var *)(t + 1);
 }
 
-static const struct btf_var_secinfo *btf_type_var_secinfo(const struct btf_type *t)
-{
-	return (const struct btf_var_secinfo *)(t + 1);
-}
-
 static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
 {
 	return kind_ops[BTF_INFO_KIND(t->info)];
@@ -661,6 +739,488 @@
 	return true;
 }
 
+/* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
+static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
+						       u32 id)
+{
+	const struct btf_type *t = btf_type_by_id(btf, id);
+
+	while (btf_type_is_modifier(t) &&
+	       BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
+		id = t->type;
+		t = btf_type_by_id(btf, t->type);
+	}
+
+	return t;
+}
+
+#define BTF_SHOW_MAX_ITER	10
+
+#define BTF_KIND_BIT(kind)	(1ULL << kind)
+
+/*
+ * Populate show->state.name with type name information.
+ * Format of type name is
+ *
+ * [.member_name = ] (type_name)
+ */
+static const char *btf_show_name(struct btf_show *show)
+{
+	/* BTF_MAX_ITER array suffixes "[]" */
+	const char *array_suffixes = "[][][][][][][][][][]";
+	const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
+	/* BTF_MAX_ITER pointer suffixes "*" */
+	const char *ptr_suffixes = "**********";
+	const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
+	const char *name = NULL, *prefix = "", *parens = "";
+	const struct btf_member *m = show->state.member;
+	const struct btf_type *t = show->state.type;
+	const struct btf_array *array;
+	u32 id = show->state.type_id;
+	const char *member = NULL;
+	bool show_member = false;
+	u64 kinds = 0;
+	int i;
+
+	show->state.name[0] = '\0';
+
+	/*
+	 * Don't show type name if we're showing an array member;
+	 * in that case we show the array type so don't need to repeat
+	 * ourselves for each member.
+	 */
+	if (show->state.array_member)
+		return "";
+
+	/* Retrieve member name, if any. */
+	if (m) {
+		member = btf_name_by_offset(show->btf, m->name_off);
+		show_member = strlen(member) > 0;
+		id = m->type;
+	}
+
+	/*
+	 * Start with type_id, as we have resolved the struct btf_type *
+	 * via btf_modifier_show() past the parent typedef to the child
+	 * struct, int etc it is defined as.  In such cases, the type_id
+	 * still represents the starting type while the struct btf_type *
+	 * in our show->state points at the resolved type of the typedef.
+	 */
+	t = btf_type_by_id(show->btf, id);
+	if (!t)
+		return "";
+
+	/*
+	 * The goal here is to build up the right number of pointer and
+	 * array suffixes while ensuring the type name for a typedef
+	 * is represented.  Along the way we accumulate a list of
+	 * BTF kinds we have encountered, since these will inform later
+	 * display; for example, pointer types will not require an
+	 * opening "{" for struct, we will just display the pointer value.
+	 *
+	 * We also want to accumulate the right number of pointer or array
+	 * indices in the format string while iterating until we get to
+	 * the typedef/pointee/array member target type.
+	 *
+	 * We start by pointing at the end of pointer and array suffix
+	 * strings; as we accumulate pointers and arrays we move the pointer
+	 * or array string backwards so it will show the expected number of
+	 * '*' or '[]' for the type.  BTF_SHOW_MAX_ITER of nesting of pointers
+	 * and/or arrays and typedefs are supported as a precaution.
+	 *
+	 * We also want to get typedef name while proceeding to resolve
+	 * type it points to so that we can add parentheses if it is a
+	 * "typedef struct" etc.
+	 */
+	for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
+
+		switch (BTF_INFO_KIND(t->info)) {
+		case BTF_KIND_TYPEDEF:
+			if (!name)
+				name = btf_name_by_offset(show->btf,
+							       t->name_off);
+			kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
+			id = t->type;
+			break;
+		case BTF_KIND_ARRAY:
+			kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
+			parens = "[";
+			if (!t)
+				return "";
+			array = btf_type_array(t);
+			if (array_suffix > array_suffixes)
+				array_suffix -= 2;
+			id = array->type;
+			break;
+		case BTF_KIND_PTR:
+			kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
+			if (ptr_suffix > ptr_suffixes)
+				ptr_suffix -= 1;
+			id = t->type;
+			break;
+		default:
+			id = 0;
+			break;
+		}
+		if (!id)
+			break;
+		t = btf_type_skip_qualifiers(show->btf, id);
+	}
+	/* We may not be able to represent this type; bail to be safe */
+	if (i == BTF_SHOW_MAX_ITER)
+		return "";
+
+	if (!name)
+		name = btf_name_by_offset(show->btf, t->name_off);
+
+	switch (BTF_INFO_KIND(t->info)) {
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION:
+		prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
+			 "struct" : "union";
+		/* if it's an array of struct/union, parens is already set */
+		if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
+			parens = "{";
+		break;
+	case BTF_KIND_ENUM:
+		prefix = "enum";
+		break;
+	default:
+		break;
+	}
+
+	/* pointer does not require parens */
+	if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
+		parens = "";
+	/* typedef does not require struct/union/enum prefix */
+	if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
+		prefix = "";
+
+	if (!name)
+		name = "";
+
+	/* Even if we don't want type name info, we want parentheses etc */
+	if (show->flags & BTF_SHOW_NONAME)
+		snprintf(show->state.name, sizeof(show->state.name), "%s",
+			 parens);
+	else
+		snprintf(show->state.name, sizeof(show->state.name),
+			 "%s%s%s(%s%s%s%s%s%s)%s",
+			 /* first 3 strings comprise ".member = " */
+			 show_member ? "." : "",
+			 show_member ? member : "",
+			 show_member ? " = " : "",
+			 /* ...next is our prefix (struct, enum, etc) */
+			 prefix,
+			 strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
+			 /* ...this is the type name itself */
+			 name,
+			 /* ...suffixed by the appropriate '*', '[]' suffixes */
+			 strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
+			 array_suffix, parens);
+
+	return show->state.name;
+}
+
+static const char *__btf_show_indent(struct btf_show *show)
+{
+	const char *indents = "                                ";
+	const char *indent = &indents[strlen(indents)];
+
+	if ((indent - show->state.depth) >= indents)
+		return indent - show->state.depth;
+	return indents;
+}
+
+static const char *btf_show_indent(struct btf_show *show)
+{
+	return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
+}
+
+static const char *btf_show_newline(struct btf_show *show)
+{
+	return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
+}
+
+static const char *btf_show_delim(struct btf_show *show)
+{
+	if (show->state.depth == 0)
+		return "";
+
+	if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
+		BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
+		return "|";
+
+	return ",";
+}
+
+__printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
+{
+	va_list args;
+
+	if (!show->state.depth_check) {
+		va_start(args, fmt);
+		show->showfn(show, fmt, args);
+		va_end(args);
+	}
+}
+
+/* Macros are used here as btf_show_type_value[s]() prepends and appends
+ * format specifiers to the format specifier passed in; these do the work of
+ * adding indentation, delimiters etc while the caller simply has to specify
+ * the type value(s) in the format specifier + value(s).
+ */
+#define btf_show_type_value(show, fmt, value)				       \
+	do {								       \
+		if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) ||	       \
+		    show->state.depth == 0) {				       \
+			btf_show(show, "%s%s" fmt "%s%s",		       \
+				 btf_show_indent(show),			       \
+				 btf_show_name(show),			       \
+				 value, btf_show_delim(show),		       \
+				 btf_show_newline(show));		       \
+			if (show->state.depth > show->state.depth_to_show)     \
+				show->state.depth_to_show = show->state.depth; \
+		}							       \
+	} while (0)
+
+#define btf_show_type_values(show, fmt, ...)				       \
+	do {								       \
+		btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show),       \
+			 btf_show_name(show),				       \
+			 __VA_ARGS__, btf_show_delim(show),		       \
+			 btf_show_newline(show));			       \
+		if (show->state.depth > show->state.depth_to_show)	       \
+			show->state.depth_to_show = show->state.depth;	       \
+	} while (0)
+
+/* How much is left to copy to safe buffer after @data? */
+static int btf_show_obj_size_left(struct btf_show *show, void *data)
+{
+	return show->obj.head + show->obj.size - data;
+}
+
+/* Is object pointed to by @data of @size already copied to our safe buffer? */
+static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
+{
+	return data >= show->obj.data &&
+	       (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
+}
+
+/*
+ * If object pointed to by @data of @size falls within our safe buffer, return
+ * the equivalent pointer to the same safe data.  Assumes
+ * copy_from_kernel_nofault() has already happened and our safe buffer is
+ * populated.
+ */
+static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
+{
+	if (btf_show_obj_is_safe(show, data, size))
+		return show->obj.safe + (data - show->obj.data);
+	return NULL;
+}
+
+/*
+ * Return a safe-to-access version of data pointed to by @data.
+ * We do this by copying the relevant amount of information
+ * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
+ *
+ * If BTF_SHOW_UNSAFE is specified, just return data as-is; no
+ * safe copy is needed.
+ *
+ * Otherwise we need to determine if we have the required amount
+ * of data (determined by the @data pointer and the size of the
+ * largest base type we can encounter (represented by
+ * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
+ * that we will be able to print some of the current object,
+ * and if more is needed a copy will be triggered.
+ * Some objects such as structs will not fit into the buffer;
+ * in such cases additional copies when we iterate over their
+ * members may be needed.
+ *
+ * btf_show_obj_safe() is used to return a safe buffer for
+ * btf_show_start_type(); this ensures that as we recurse into
+ * nested types we always have safe data for the given type.
+ * This approach is somewhat wasteful; it's possible for example
+ * that when iterating over a large union we'll end up copying the
+ * same data repeatedly, but the goal is safety not performance.
+ * We use stack data as opposed to per-CPU buffers because the
+ * iteration over a type can take some time, and preemption handling
+ * would greatly complicate use of the safe buffer.
+ */
+static void *btf_show_obj_safe(struct btf_show *show,
+			       const struct btf_type *t,
+			       void *data)
+{
+	const struct btf_type *rt;
+	int size_left, size;
+	void *safe = NULL;
+
+	if (show->flags & BTF_SHOW_UNSAFE)
+		return data;
+
+	rt = btf_resolve_size(show->btf, t, &size);
+	if (IS_ERR(rt)) {
+		show->state.status = PTR_ERR(rt);
+		return NULL;
+	}
+
+	/*
+	 * Is this toplevel object? If so, set total object size and
+	 * initialize pointers.  Otherwise check if we still fall within
+	 * our safe object data.
+	 */
+	if (show->state.depth == 0) {
+		show->obj.size = size;
+		show->obj.head = data;
+	} else {
+		/*
+		 * If the size of the current object is > our remaining
+		 * safe buffer we _may_ need to do a new copy.  However
+		 * consider the case of a nested struct; it's size pushes
+		 * us over the safe buffer limit, but showing any individual
+		 * struct members does not.  In such cases, we don't need
+		 * to initiate a fresh copy yet; however we definitely need
+		 * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
+		 * in our buffer, regardless of the current object size.
+		 * The logic here is that as we resolve types we will
+		 * hit a base type at some point, and we need to be sure
+		 * the next chunk of data is safely available to display
+		 * that type info safely.  We cannot rely on the size of
+		 * the current object here because it may be much larger
+		 * than our current buffer (e.g. task_struct is 8k).
+		 * All we want to do here is ensure that we can print the
+		 * next basic type, which we can if either
+		 * - the current type size is within the safe buffer; or
+		 * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
+		 *   the safe buffer.
+		 */
+		safe = __btf_show_obj_safe(show, data,
+					   min(size,
+					       BTF_SHOW_OBJ_BASE_TYPE_SIZE));
+	}
+
+	/*
+	 * We need a new copy to our safe object, either because we haven't
+	 * yet copied and are intializing safe data, or because the data
+	 * we want falls outside the boundaries of the safe object.
+	 */
+	if (!safe) {
+		size_left = btf_show_obj_size_left(show, data);
+		if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
+			size_left = BTF_SHOW_OBJ_SAFE_SIZE;
+		show->state.status = copy_from_kernel_nofault(show->obj.safe,
+							      data, size_left);
+		if (!show->state.status) {
+			show->obj.data = data;
+			safe = show->obj.safe;
+		}
+	}
+
+	return safe;
+}
+
+/*
+ * Set the type we are starting to show and return a safe data pointer
+ * to be used for showing the associated data.
+ */
+static void *btf_show_start_type(struct btf_show *show,
+				 const struct btf_type *t,
+				 u32 type_id, void *data)
+{
+	show->state.type = t;
+	show->state.type_id = type_id;
+	show->state.name[0] = '\0';
+
+	return btf_show_obj_safe(show, t, data);
+}
+
+static void btf_show_end_type(struct btf_show *show)
+{
+	show->state.type = NULL;
+	show->state.type_id = 0;
+	show->state.name[0] = '\0';
+}
+
+static void *btf_show_start_aggr_type(struct btf_show *show,
+				      const struct btf_type *t,
+				      u32 type_id, void *data)
+{
+	void *safe_data = btf_show_start_type(show, t, type_id, data);
+
+	if (!safe_data)
+		return safe_data;
+
+	btf_show(show, "%s%s%s", btf_show_indent(show),
+		 btf_show_name(show),
+		 btf_show_newline(show));
+	show->state.depth++;
+	return safe_data;
+}
+
+static void btf_show_end_aggr_type(struct btf_show *show,
+				   const char *suffix)
+{
+	show->state.depth--;
+	btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix,
+		 btf_show_delim(show), btf_show_newline(show));
+	btf_show_end_type(show);
+}
+
+static void btf_show_start_member(struct btf_show *show,
+				  const struct btf_member *m)
+{
+	show->state.member = m;
+}
+
+static void btf_show_start_array_member(struct btf_show *show)
+{
+	show->state.array_member = 1;
+	btf_show_start_member(show, NULL);
+}
+
+static void btf_show_end_member(struct btf_show *show)
+{
+	show->state.member = NULL;
+}
+
+static void btf_show_end_array_member(struct btf_show *show)
+{
+	show->state.array_member = 0;
+	btf_show_end_member(show);
+}
+
+static void *btf_show_start_array_type(struct btf_show *show,
+				       const struct btf_type *t,
+				       u32 type_id,
+				       u16 array_encoding,
+				       void *data)
+{
+	show->state.array_encoding = array_encoding;
+	show->state.array_terminated = 0;
+	return btf_show_start_aggr_type(show, t, type_id, data);
+}
+
+static void btf_show_end_array_type(struct btf_show *show)
+{
+	show->state.array_encoding = 0;
+	show->state.array_terminated = 0;
+	btf_show_end_aggr_type(show, "]");
+}
+
+static void *btf_show_start_struct_type(struct btf_show *show,
+					const struct btf_type *t,
+					u32 type_id,
+					void *data)
+{
+	return btf_show_start_aggr_type(show, t, type_id, data);
+}
+
+static void btf_show_end_struct_type(struct btf_show *show)
+{
+	btf_show_end_aggr_type(show, "}");
+}
+
 __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
 					      const char *fmt, ...)
 {
@@ -698,6 +1258,13 @@
 	if (!bpf_verifier_log_needed(log))
 		return;
 
+	/* btf verifier prints all types it is processing via
+	 * btf_verifier_log_type(..., fmt = NULL).
+	 * Skip those prints for in-kernel BTF verification.
+	 */
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
+
 	__btf_verifier_log(log, "[%u] %s %s%s",
 			   env->log_type_id,
 			   btf_kind_str[kind],
@@ -735,6 +1302,8 @@
 	if (!bpf_verifier_log_needed(log))
 		return;
 
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
 	/* The CHECK_META phase already did a btf dump.
 	 *
 	 * If member is logged again, it must hit an error in
@@ -777,6 +1346,8 @@
 
 	if (!bpf_verifier_log_needed(log))
 		return;
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
 	if (env->phase != CHECK_META)
 		btf_verifier_log_type(env, datasec_type, NULL);
 
@@ -802,6 +1373,8 @@
 	if (!bpf_verifier_log_needed(log))
 		return;
 
+	if (log->level == BPF_LOG_KERNEL)
+		return;
 	hdr = &btf->hdr;
 	__btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
 	__btf_verifier_log(log, "version: %u\n", hdr->version);
@@ -1043,6 +1616,100 @@
 	return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
 }
 
+/* Resolve the size of a passed-in "type"
+ *
+ * type: is an array (e.g. u32 array[x][y])
+ * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
+ * *type_size: (x * y * sizeof(u32)).  Hence, *type_size always
+ *             corresponds to the return type.
+ * *elem_type: u32
+ * *elem_id: id of u32
+ * *total_nelems: (x * y).  Hence, individual elem size is
+ *                (*type_size / *total_nelems)
+ * *type_id: id of type if it's changed within the function, 0 if not
+ *
+ * type: is not an array (e.g. const struct X)
+ * return type: type "struct X"
+ * *type_size: sizeof(struct X)
+ * *elem_type: same as return type ("struct X")
+ * *elem_id: 0
+ * *total_nelems: 1
+ * *type_id: id of type if it's changed within the function, 0 if not
+ */
+static const struct btf_type *
+__btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+		   u32 *type_size, const struct btf_type **elem_type,
+		   u32 *elem_id, u32 *total_nelems, u32 *type_id)
+{
+	const struct btf_type *array_type = NULL;
+	const struct btf_array *array = NULL;
+	u32 i, size, nelems = 1, id = 0;
+
+	for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
+		switch (BTF_INFO_KIND(type->info)) {
+		/* type->size can be used */
+		case BTF_KIND_INT:
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION:
+		case BTF_KIND_ENUM:
+			size = type->size;
+			goto resolved;
+
+		case BTF_KIND_PTR:
+			size = sizeof(void *);
+			goto resolved;
+
+		/* Modifiers */
+		case BTF_KIND_TYPEDEF:
+		case BTF_KIND_VOLATILE:
+		case BTF_KIND_CONST:
+		case BTF_KIND_RESTRICT:
+			id = type->type;
+			type = btf_type_by_id(btf, type->type);
+			break;
+
+		case BTF_KIND_ARRAY:
+			if (!array_type)
+				array_type = type;
+			array = btf_type_array(type);
+			if (nelems && array->nelems > U32_MAX / nelems)
+				return ERR_PTR(-EINVAL);
+			nelems *= array->nelems;
+			type = btf_type_by_id(btf, array->type);
+			break;
+
+		/* type without size */
+		default:
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	return ERR_PTR(-EINVAL);
+
+resolved:
+	if (nelems && size > U32_MAX / nelems)
+		return ERR_PTR(-EINVAL);
+
+	*type_size = nelems * size;
+	if (total_nelems)
+		*total_nelems = nelems;
+	if (elem_type)
+		*elem_type = type;
+	if (elem_id)
+		*elem_id = array ? array->type : 0;
+	if (type_id && id)
+		*type_id = id;
+
+	return array_type ? : type;
+}
+
+const struct btf_type *
+btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+		 u32 *type_size)
+{
+	return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
+}
+
 /* The input param "type_id" must point to a needs_resolve type */
 static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
 						  u32 *type_id)
@@ -1143,11 +1810,11 @@
 	return -EINVAL;
 }
 
-static void btf_df_seq_show(const struct btf *btf, const struct btf_type *t,
-			    u32 type_id, void *data, u8 bits_offsets,
-			    struct seq_file *m)
+static void btf_df_show(const struct btf *btf, const struct btf_type *t,
+			u32 type_id, void *data, u8 bits_offsets,
+			struct btf_show *show)
 {
-	seq_printf(m, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
+	btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
 }
 
 static int btf_int_check_member(struct btf_verifier_env *env,
@@ -1320,7 +1987,7 @@
 			 btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
 }
 
-static void btf_int128_print(struct seq_file *m, void *data)
+static void btf_int128_print(struct btf_show *show, void *data)
 {
 	/* data points to a __int128 number.
 	 * Suppose
@@ -1339,9 +2006,10 @@
 	lower_num = *(u64 *)data;
 #endif
 	if (upper_num == 0)
-		seq_printf(m, "0x%llx", lower_num);
+		btf_show_type_value(show, "0x%llx", lower_num);
 	else
-		seq_printf(m, "0x%llx%016llx", upper_num, lower_num);
+		btf_show_type_values(show, "0x%llx%016llx", upper_num,
+				     lower_num);
 }
 
 static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
@@ -1385,8 +2053,8 @@
 #endif
 }
 
-static void btf_bitfield_seq_show(void *data, u8 bits_offset,
-				  u8 nr_bits, struct seq_file *m)
+static void btf_bitfield_show(void *data, u8 bits_offset,
+			      u8 nr_bits, struct btf_show *show)
 {
 	u16 left_shift_bits, right_shift_bits;
 	u8 nr_copy_bytes;
@@ -1406,14 +2074,14 @@
 	right_shift_bits = BITS_PER_U128 - nr_bits;
 
 	btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
-	btf_int128_print(m, print_num);
+	btf_int128_print(show, print_num);
 }
 
 
-static void btf_int_bits_seq_show(const struct btf *btf,
-				  const struct btf_type *t,
-				  void *data, u8 bits_offset,
-				  struct seq_file *m)
+static void btf_int_bits_show(const struct btf *btf,
+			      const struct btf_type *t,
+			      void *data, u8 bits_offset,
+			      struct btf_show *show)
 {
 	u32 int_data = btf_type_int(t);
 	u8 nr_bits = BTF_INT_BITS(int_data);
@@ -1426,55 +2094,77 @@
 	total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
 	data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
 	bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
-	btf_bitfield_seq_show(data, bits_offset, nr_bits, m);
+	btf_bitfield_show(data, bits_offset, nr_bits, show);
 }
 
-static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t,
-			     u32 type_id, void *data, u8 bits_offset,
-			     struct seq_file *m)
+static void btf_int_show(const struct btf *btf, const struct btf_type *t,
+			 u32 type_id, void *data, u8 bits_offset,
+			 struct btf_show *show)
 {
 	u32 int_data = btf_type_int(t);
 	u8 encoding = BTF_INT_ENCODING(int_data);
 	bool sign = encoding & BTF_INT_SIGNED;
 	u8 nr_bits = BTF_INT_BITS(int_data);
+	void *safe_data;
+
+	safe_data = btf_show_start_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
 
 	if (bits_offset || BTF_INT_OFFSET(int_data) ||
 	    BITS_PER_BYTE_MASKED(nr_bits)) {
-		btf_int_bits_seq_show(btf, t, data, bits_offset, m);
-		return;
+		btf_int_bits_show(btf, t, safe_data, bits_offset, show);
+		goto out;
 	}
 
 	switch (nr_bits) {
 	case 128:
-		btf_int128_print(m, data);
+		btf_int128_print(show, safe_data);
 		break;
 	case 64:
 		if (sign)
-			seq_printf(m, "%lld", *(s64 *)data);
+			btf_show_type_value(show, "%lld", *(s64 *)safe_data);
 		else
-			seq_printf(m, "%llu", *(u64 *)data);
+			btf_show_type_value(show, "%llu", *(u64 *)safe_data);
 		break;
 	case 32:
 		if (sign)
-			seq_printf(m, "%d", *(s32 *)data);
+			btf_show_type_value(show, "%d", *(s32 *)safe_data);
 		else
-			seq_printf(m, "%u", *(u32 *)data);
+			btf_show_type_value(show, "%u", *(u32 *)safe_data);
 		break;
 	case 16:
 		if (sign)
-			seq_printf(m, "%d", *(s16 *)data);
+			btf_show_type_value(show, "%d", *(s16 *)safe_data);
 		else
-			seq_printf(m, "%u", *(u16 *)data);
+			btf_show_type_value(show, "%u", *(u16 *)safe_data);
 		break;
 	case 8:
+		if (show->state.array_encoding == BTF_INT_CHAR) {
+			/* check for null terminator */
+			if (show->state.array_terminated)
+				break;
+			if (*(char *)data == '\0') {
+				show->state.array_terminated = 1;
+				break;
+			}
+			if (isprint(*(char *)data)) {
+				btf_show_type_value(show, "'%c'",
+						    *(char *)safe_data);
+				break;
+			}
+		}
 		if (sign)
-			seq_printf(m, "%d", *(s8 *)data);
+			btf_show_type_value(show, "%d", *(s8 *)safe_data);
 		else
-			seq_printf(m, "%u", *(u8 *)data);
+			btf_show_type_value(show, "%u", *(u8 *)safe_data);
 		break;
 	default:
-		btf_int_bits_seq_show(btf, t, data, bits_offset, m);
+		btf_int_bits_show(btf, t, safe_data, bits_offset, show);
+		break;
 	}
+out:
+	btf_show_end_type(show);
 }
 
 static const struct btf_kind_operations int_ops = {
@@ -1483,7 +2173,7 @@
 	.check_member = btf_int_check_member,
 	.check_kflag_member = btf_int_check_kflag_member,
 	.log_details = btf_int_log,
-	.seq_show = btf_int_seq_show,
+	.show = btf_int_show,
 };
 
 static int btf_modifier_check_member(struct btf_verifier_env *env,
@@ -1747,31 +2437,44 @@
 	return 0;
 }
 
-static void btf_modifier_seq_show(const struct btf *btf,
-				  const struct btf_type *t,
-				  u32 type_id, void *data,
-				  u8 bits_offset, struct seq_file *m)
+static void btf_modifier_show(const struct btf *btf,
+			      const struct btf_type *t,
+			      u32 type_id, void *data,
+			      u8 bits_offset, struct btf_show *show)
+{
+	if (btf->resolved_ids)
+		t = btf_type_id_resolve(btf, &type_id);
+	else
+		t = btf_type_skip_modifiers(btf, type_id, NULL);
+
+	btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
+}
+
+static void btf_var_show(const struct btf *btf, const struct btf_type *t,
+			 u32 type_id, void *data, u8 bits_offset,
+			 struct btf_show *show)
 {
 	t = btf_type_id_resolve(btf, &type_id);
 
-	btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
+	btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
 }
 
-static void btf_var_seq_show(const struct btf *btf, const struct btf_type *t,
-			     u32 type_id, void *data, u8 bits_offset,
-			     struct seq_file *m)
+static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
+			 u32 type_id, void *data, u8 bits_offset,
+			 struct btf_show *show)
 {
-	t = btf_type_id_resolve(btf, &type_id);
+	void *safe_data;
 
-	btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
-}
+	safe_data = btf_show_start_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
 
-static void btf_ptr_seq_show(const struct btf *btf, const struct btf_type *t,
-			     u32 type_id, void *data, u8 bits_offset,
-			     struct seq_file *m)
-{
-	/* It is a hashed value */
-	seq_printf(m, "%p", *(void **)data);
+	/* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
+	if (show->flags & BTF_SHOW_PTR_RAW)
+		btf_show_type_value(show, "0x%px", *(void **)safe_data);
+	else
+		btf_show_type_value(show, "0x%p", *(void **)safe_data);
+	btf_show_end_type(show);
 }
 
 static void btf_ref_type_log(struct btf_verifier_env *env,
@@ -1786,7 +2489,7 @@
 	.check_member = btf_modifier_check_member,
 	.check_kflag_member = btf_modifier_check_kflag_member,
 	.log_details = btf_ref_type_log,
-	.seq_show = btf_modifier_seq_show,
+	.show = btf_modifier_show,
 };
 
 static struct btf_kind_operations ptr_ops = {
@@ -1795,7 +2498,7 @@
 	.check_member = btf_ptr_check_member,
 	.check_kflag_member = btf_generic_check_kflag_member,
 	.log_details = btf_ref_type_log,
-	.seq_show = btf_ptr_seq_show,
+	.show = btf_ptr_show,
 };
 
 static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
@@ -1836,7 +2539,7 @@
 	.check_member = btf_df_check_member,
 	.check_kflag_member = btf_df_check_kflag_member,
 	.log_details = btf_fwd_type_log,
-	.seq_show = btf_df_seq_show,
+	.show = btf_df_show,
 };
 
 static int btf_array_check_member(struct btf_verifier_env *env,
@@ -1995,28 +2698,90 @@
 			 array->type, array->index_type, array->nelems);
 }
 
-static void btf_array_seq_show(const struct btf *btf, const struct btf_type *t,
-			       u32 type_id, void *data, u8 bits_offset,
-			       struct seq_file *m)
+static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
+			     u32 type_id, void *data, u8 bits_offset,
+			     struct btf_show *show)
 {
 	const struct btf_array *array = btf_type_array(t);
 	const struct btf_kind_operations *elem_ops;
 	const struct btf_type *elem_type;
-	u32 i, elem_size, elem_type_id;
+	u32 i, elem_size = 0, elem_type_id;
+	u16 encoding = 0;
 
 	elem_type_id = array->type;
-	elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
-	elem_ops = btf_type_ops(elem_type);
-	seq_puts(m, "[");
-	for (i = 0; i < array->nelems; i++) {
-		if (i)
-			seq_puts(m, ",");
+	elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL);
+	if (elem_type && btf_type_has_size(elem_type))
+		elem_size = elem_type->size;
 
-		elem_ops->seq_show(btf, elem_type, elem_type_id, data,
-				   bits_offset, m);
-		data += elem_size;
+	if (elem_type && btf_type_is_int(elem_type)) {
+		u32 int_type = btf_type_int(elem_type);
+
+		encoding = BTF_INT_ENCODING(int_type);
+
+		/*
+		 * BTF_INT_CHAR encoding never seems to be set for
+		 * char arrays, so if size is 1 and element is
+		 * printable as a char, we'll do that.
+		 */
+		if (elem_size == 1)
+			encoding = BTF_INT_CHAR;
 	}
-	seq_puts(m, "]");
+
+	if (!btf_show_start_array_type(show, t, type_id, encoding, data))
+		return;
+
+	if (!elem_type)
+		goto out;
+	elem_ops = btf_type_ops(elem_type);
+
+	for (i = 0; i < array->nelems; i++) {
+
+		btf_show_start_array_member(show);
+
+		elem_ops->show(btf, elem_type, elem_type_id, data,
+			       bits_offset, show);
+		data += elem_size;
+
+		btf_show_end_array_member(show);
+
+		if (show->state.array_terminated)
+			break;
+	}
+out:
+	btf_show_end_array_type(show);
+}
+
+static void btf_array_show(const struct btf *btf, const struct btf_type *t,
+			   u32 type_id, void *data, u8 bits_offset,
+			   struct btf_show *show)
+{
+	const struct btf_member *m = show->state.member;
+
+	/*
+	 * First check if any members would be shown (are non-zero).
+	 * See comments above "struct btf_show" definition for more
+	 * details on how this works at a high-level.
+	 */
+	if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
+		if (!show->state.depth_check) {
+			show->state.depth_check = show->state.depth + 1;
+			show->state.depth_to_show = 0;
+		}
+		__btf_array_show(btf, t, type_id, data, bits_offset, show);
+		show->state.member = m;
+
+		if (show->state.depth_check != show->state.depth + 1)
+			return;
+		show->state.depth_check = 0;
+
+		if (show->state.depth_to_show <= show->state.depth)
+			return;
+		/*
+		 * Reaching here indicates we have recursed and found
+		 * non-zero array member(s).
+		 */
+	}
+	__btf_array_show(btf, t, type_id, data, bits_offset, show);
 }
 
 static struct btf_kind_operations array_ops = {
@@ -2025,7 +2790,7 @@
 	.check_member = btf_array_check_member,
 	.check_kflag_member = btf_generic_check_kflag_member,
 	.log_details = btf_array_log,
-	.seq_show = btf_array_seq_show,
+	.show = btf_array_show,
 };
 
 static int btf_struct_check_member(struct btf_verifier_env *env,
@@ -2248,15 +3013,18 @@
 	return off;
 }
 
-static void btf_struct_seq_show(const struct btf *btf, const struct btf_type *t,
-				u32 type_id, void *data, u8 bits_offset,
-				struct seq_file *m)
+static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
+			      u32 type_id, void *data, u8 bits_offset,
+			      struct btf_show *show)
 {
-	const char *seq = BTF_INFO_KIND(t->info) == BTF_KIND_UNION ? "|" : ",";
 	const struct btf_member *member;
+	void *safe_data;
 	u32 i;
 
-	seq_puts(m, "{");
+	safe_data = btf_show_start_struct_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
+
 	for_each_member(i, t, member) {
 		const struct btf_type *member_type = btf_type_by_id(btf,
 								member->type);
@@ -2265,23 +3033,65 @@
 		u32 bytes_offset;
 		u8 bits8_offset;
 
-		if (i)
-			seq_puts(m, seq);
+		btf_show_start_member(show, member);
 
 		member_offset = btf_member_bit_offset(t, member);
 		bitfield_size = btf_member_bitfield_size(t, member);
 		bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
 		bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
 		if (bitfield_size) {
-			btf_bitfield_seq_show(data + bytes_offset, bits8_offset,
-					      bitfield_size, m);
+			safe_data = btf_show_start_type(show, member_type,
+							member->type,
+							data + bytes_offset);
+			if (safe_data)
+				btf_bitfield_show(safe_data,
+						  bits8_offset,
+						  bitfield_size, show);
+			btf_show_end_type(show);
 		} else {
 			ops = btf_type_ops(member_type);
-			ops->seq_show(btf, member_type, member->type,
-				      data + bytes_offset, bits8_offset, m);
+			ops->show(btf, member_type, member->type,
+				  data + bytes_offset, bits8_offset, show);
 		}
+
+		btf_show_end_member(show);
 	}
-	seq_puts(m, "}");
+
+	btf_show_end_struct_type(show);
+}
+
+static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
+			    u32 type_id, void *data, u8 bits_offset,
+			    struct btf_show *show)
+{
+	const struct btf_member *m = show->state.member;
+
+	/*
+	 * First check if any members would be shown (are non-zero).
+	 * See comments above "struct btf_show" definition for more
+	 * details on how this works at a high-level.
+	 */
+	if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
+		if (!show->state.depth_check) {
+			show->state.depth_check = show->state.depth + 1;
+			show->state.depth_to_show = 0;
+		}
+		__btf_struct_show(btf, t, type_id, data, bits_offset, show);
+		/* Restore saved member data here */
+		show->state.member = m;
+		if (show->state.depth_check != show->state.depth + 1)
+			return;
+		show->state.depth_check = 0;
+
+		if (show->state.depth_to_show <= show->state.depth)
+			return;
+		/*
+		 * Reaching here indicates we have recursed and found
+		 * non-zero child values.
+		 */
+	}
+
+	__btf_struct_show(btf, t, type_id, data, bits_offset, show);
 }
 
 static struct btf_kind_operations struct_ops = {
@@ -2290,7 +3100,7 @@
 	.check_member = btf_struct_check_member,
 	.check_kflag_member = btf_generic_check_kflag_member,
 	.log_details = btf_struct_log,
-	.seq_show = btf_struct_seq_show,
+	.show = btf_struct_show,
 };
 
 static int btf_enum_check_member(struct btf_verifier_env *env,
@@ -2405,7 +3215,8 @@
 			return -EINVAL;
 		}
 
-
+		if (env->log.level == BPF_LOG_KERNEL)
+			continue;
 		btf_verifier_log(env, "\t%s val=%d\n",
 				 __btf_name_by_offset(btf, enums[i].name_off),
 				 enums[i].val);
@@ -2420,24 +3231,35 @@
 	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
 }
 
-static void btf_enum_seq_show(const struct btf *btf, const struct btf_type *t,
-			      u32 type_id, void *data, u8 bits_offset,
-			      struct seq_file *m)
+static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
+			  u32 type_id, void *data, u8 bits_offset,
+			  struct btf_show *show)
 {
 	const struct btf_enum *enums = btf_type_enum(t);
 	u32 i, nr_enums = btf_type_vlen(t);
-	int v = *(int *)data;
+	void *safe_data;
+	int v;
+
+	safe_data = btf_show_start_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
+
+	v = *(int *)safe_data;
 
 	for (i = 0; i < nr_enums; i++) {
-		if (v == enums[i].val) {
-			seq_printf(m, "%s",
-				   __btf_name_by_offset(btf,
-							enums[i].name_off));
-			return;
-		}
+		if (v != enums[i].val)
+			continue;
+
+		btf_show_type_value(show, "%s",
+				    __btf_name_by_offset(btf,
+							 enums[i].name_off));
+
+		btf_show_end_type(show);
+		return;
 	}
 
-	seq_printf(m, "%d", v);
+	btf_show_type_value(show, "%d", v);
+	btf_show_end_type(show);
 }
 
 static struct btf_kind_operations enum_ops = {
@@ -2446,7 +3268,7 @@
 	.check_member = btf_enum_check_member,
 	.check_kflag_member = btf_enum_check_kflag_member,
 	.log_details = btf_enum_log,
-	.seq_show = btf_enum_seq_show,
+	.show = btf_enum_show,
 };
 
 static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
@@ -2533,7 +3355,7 @@
 	.check_member = btf_df_check_member,
 	.check_kflag_member = btf_df_check_kflag_member,
 	.log_details = btf_func_proto_log,
-	.seq_show = btf_df_seq_show,
+	.show = btf_df_show,
 };
 
 static s32 btf_func_check_meta(struct btf_verifier_env *env,
@@ -2546,8 +3368,8 @@
 		return -EINVAL;
 	}
 
-	if (btf_type_vlen(t)) {
-		btf_verifier_log_type(env, t, "vlen != 0");
+	if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
+		btf_verifier_log_type(env, t, "Invalid func linkage");
 		return -EINVAL;
 	}
 
@@ -2567,7 +3389,7 @@
 	.check_member = btf_df_check_member,
 	.check_kflag_member = btf_df_check_kflag_member,
 	.log_details = btf_ref_type_log,
-	.seq_show = btf_df_seq_show,
+	.show = btf_df_show,
 };
 
 static s32 btf_var_check_meta(struct btf_verifier_env *env,
@@ -2631,7 +3453,7 @@
 	.check_member		= btf_df_check_member,
 	.check_kflag_member	= btf_df_check_kflag_member,
 	.log_details		= btf_var_log,
-	.seq_show		= btf_var_seq_show,
+	.show			= btf_var_show,
 };
 
 static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
@@ -2757,24 +3579,28 @@
 	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
 }
 
-static void btf_datasec_seq_show(const struct btf *btf,
-				 const struct btf_type *t, u32 type_id,
-				 void *data, u8 bits_offset,
-				 struct seq_file *m)
+static void btf_datasec_show(const struct btf *btf,
+			     const struct btf_type *t, u32 type_id,
+			     void *data, u8 bits_offset,
+			     struct btf_show *show)
 {
 	const struct btf_var_secinfo *vsi;
 	const struct btf_type *var;
 	u32 i;
 
-	seq_printf(m, "section (\"%s\") = {", __btf_name_by_offset(btf, t->name_off));
+	if (!btf_show_start_type(show, t, type_id, data))
+		return;
+
+	btf_show_type_value(show, "section (\"%s\") = {",
+			    __btf_name_by_offset(btf, t->name_off));
 	for_each_vsi(i, t, vsi) {
 		var = btf_type_by_id(btf, vsi->type);
 		if (i)
-			seq_puts(m, ",");
-		btf_type_ops(var)->seq_show(btf, var, vsi->type,
-					    data + vsi->offset, bits_offset, m);
+			btf_show(show, ",");
+		btf_type_ops(var)->show(btf, var, vsi->type,
+					data + vsi->offset, bits_offset, show);
 	}
-	seq_puts(m, "}");
+	btf_show_end_type(show);
 }
 
 static const struct btf_kind_operations datasec_ops = {
@@ -2783,7 +3609,7 @@
 	.check_member		= btf_df_check_member,
 	.check_kflag_member	= btf_df_check_kflag_member,
 	.log_details		= btf_datasec_log,
-	.seq_show		= btf_datasec_seq_show,
+	.show			= btf_datasec_show,
 };
 
 static int btf_func_proto_check(struct btf_verifier_env *env,
@@ -3309,8 +4135,7 @@
 		log->len_total = log_size;
 
 		/* log attributes have to be sane */
-		if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
-		    !log->level || !log->ubuf) {
+		if (!bpf_verifier_log_attr_valid(log)) {
 			err = -EINVAL;
 			goto errout;
 		}
@@ -3367,12 +4192,1222 @@
 	return ERR_PTR(err);
 }
 
-void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
-		       struct seq_file *m)
+extern char __weak __start_BTF[];
+extern char __weak __stop_BTF[];
+extern struct btf *btf_vmlinux;
+
+#define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name)
+static union {
+	struct bpf_ctx_convert {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	prog_ctx_type _id##_prog; \
+	kern_ctx_type _id##_kern;
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+	} *__t;
+	/* 't' is written once under lock. Read many times. */
+	const struct btf_type *t;
+} bpf_ctx_convert;
+enum {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	__ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+	__ctx_convert_unused, /* to avoid empty enum in extreme .config */
+};
+static u8 bpf_ctx_convert_map[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	[_id] = __ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+	0, /* avoid empty array */
+};
+#undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
+
+static const struct btf_member *
+btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
+		      const struct btf_type *t, enum bpf_prog_type prog_type,
+		      int arg)
+{
+	const struct btf_type *conv_struct;
+	const struct btf_type *ctx_struct;
+	const struct btf_member *ctx_type;
+	const char *tname, *ctx_tname;
+
+	conv_struct = bpf_ctx_convert.t;
+	if (!conv_struct) {
+		bpf_log(log, "btf_vmlinux is malformed\n");
+		return NULL;
+	}
+	t = btf_type_by_id(btf, t->type);
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!btf_type_is_struct(t)) {
+		/* Only pointer to struct is supported for now.
+		 * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
+		 * is not supported yet.
+		 * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
+		 */
+		if (log->level & BPF_LOG_LEVEL)
+			bpf_log(log, "arg#%d type is not a struct\n", arg);
+		return NULL;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+	if (!tname) {
+		bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
+		return NULL;
+	}
+	/* prog_type is valid bpf program type. No need for bounds check. */
+	ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
+	/* ctx_struct is a pointer to prog_ctx_type in vmlinux.
+	 * Like 'struct __sk_buff'
+	 */
+	ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
+	if (!ctx_struct)
+		/* should not happen */
+		return NULL;
+	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
+	if (!ctx_tname) {
+		/* should not happen */
+		bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
+		return NULL;
+	}
+	/* only compare that prog's ctx type name is the same as
+	 * kernel expects. No need to compare field by field.
+	 * It's ok for bpf prog to do:
+	 * struct __sk_buff {};
+	 * int socket_filter_bpf_prog(struct __sk_buff *skb)
+	 * { // no fields of skb are ever used }
+	 */
+	if (strcmp(ctx_tname, tname))
+		return NULL;
+	return ctx_type;
+}
+
+static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
+#define BPF_LINK_TYPE(_id, _name)
+#define BPF_MAP_TYPE(_id, _ops) \
+	[_id] = &_ops,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+#undef BPF_LINK_TYPE
+#undef BPF_MAP_TYPE
+};
+
+static int btf_vmlinux_map_ids_init(const struct btf *btf,
+				    struct bpf_verifier_log *log)
+{
+	const struct bpf_map_ops *ops;
+	int i, btf_id;
+
+	for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) {
+		ops = btf_vmlinux_map_ops[i];
+		if (!ops || (!ops->map_btf_name && !ops->map_btf_id))
+			continue;
+		if (!ops->map_btf_name || !ops->map_btf_id) {
+			bpf_log(log, "map type %d is misconfigured\n", i);
+			return -EINVAL;
+		}
+		btf_id = btf_find_by_name_kind(btf, ops->map_btf_name,
+					       BTF_KIND_STRUCT);
+		if (btf_id < 0)
+			return btf_id;
+		*ops->map_btf_id = btf_id;
+	}
+
+	return 0;
+}
+
+static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
+				     struct btf *btf,
+				     const struct btf_type *t,
+				     enum bpf_prog_type prog_type,
+				     int arg)
+{
+	const struct btf_member *prog_ctx_type, *kern_ctx_type;
+
+	prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
+	if (!prog_ctx_type)
+		return -ENOENT;
+	kern_ctx_type = prog_ctx_type + 1;
+	return kern_ctx_type->type;
+}
+
+BTF_ID_LIST(bpf_ctx_convert_btf_id)
+BTF_ID(struct, bpf_ctx_convert)
+
+struct btf *btf_parse_vmlinux(void)
+{
+	struct btf_verifier_env *env = NULL;
+	struct bpf_verifier_log *log;
+	struct btf *btf = NULL;
+	int err;
+
+	env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
+	if (!env)
+		return ERR_PTR(-ENOMEM);
+
+	log = &env->log;
+	log->level = BPF_LOG_KERNEL;
+
+	btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
+	if (!btf) {
+		err = -ENOMEM;
+		goto errout;
+	}
+	env->btf = btf;
+
+	btf->data = __start_BTF;
+	btf->data_size = __stop_BTF - __start_BTF;
+
+	err = btf_parse_hdr(env);
+	if (err)
+		goto errout;
+
+	btf->nohdr_data = btf->data + btf->hdr.hdr_len;
+
+	err = btf_parse_str_sec(env);
+	if (err)
+		goto errout;
+
+	err = btf_check_all_metas(env);
+	if (err)
+		goto errout;
+
+	/* btf_parse_vmlinux() runs under bpf_verifier_lock */
+	bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);
+
+	/* find bpf map structs for map_ptr access checking */
+	err = btf_vmlinux_map_ids_init(btf, log);
+	if (err < 0)
+		goto errout;
+
+	bpf_struct_ops_init(btf, log);
+
+	btf_verifier_env_free(env);
+	refcount_set(&btf->refcnt, 1);
+	return btf;
+
+errout:
+	btf_verifier_env_free(env);
+	if (btf) {
+		kvfree(btf->types);
+		kfree(btf);
+	}
+	return ERR_PTR(err);
+}
+
+struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
+{
+	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
+
+	if (tgt_prog) {
+		return tgt_prog->aux->btf;
+	} else {
+		return btf_vmlinux;
+	}
+}
+
+static bool is_string_ptr(struct btf *btf, const struct btf_type *t)
+{
+	/* t comes in already as a pointer */
+	t = btf_type_by_id(btf, t->type);
+
+	/* allow const */
+	if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
+		t = btf_type_by_id(btf, t->type);
+
+	/* char, signed char, unsigned char */
+	return btf_type_is_int(t) && t->size == 1;
+}
+
+bool btf_ctx_access(int off, int size, enum bpf_access_type type,
+		    const struct bpf_prog *prog,
+		    struct bpf_insn_access_aux *info)
+{
+	const struct btf_type *t = prog->aux->attach_func_proto;
+	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
+	struct btf *btf = bpf_prog_get_target_btf(prog);
+	const char *tname = prog->aux->attach_func_name;
+	struct bpf_verifier_log *log = info->log;
+	const struct btf_param *args;
+	u32 nr_args, arg;
+	int i, ret;
+
+	if (off % 8) {
+		bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
+			tname, off);
+		return false;
+	}
+	arg = off / 8;
+	args = (const struct btf_param *)(t + 1);
+	/* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */
+	nr_args = t ? btf_type_vlen(t) : 5;
+	if (prog->aux->attach_btf_trace) {
+		/* skip first 'void *__data' argument in btf_trace_##name typedef */
+		args++;
+		nr_args--;
+	}
+
+	if (arg > nr_args) {
+		bpf_log(log, "func '%s' doesn't have %d-th argument\n",
+			tname, arg + 1);
+		return false;
+	}
+
+	if (arg == nr_args) {
+		switch (prog->expected_attach_type) {
+		case BPF_LSM_MAC:
+		case BPF_TRACE_FEXIT:
+			/* When LSM programs are attached to void LSM hooks
+			 * they use FEXIT trampolines and when attached to
+			 * int LSM hooks, they use MODIFY_RETURN trampolines.
+			 *
+			 * While the LSM programs are BPF_MODIFY_RETURN-like
+			 * the check:
+			 *
+			 *	if (ret_type != 'int')
+			 *		return -EINVAL;
+			 *
+			 * is _not_ done here. This is still safe as LSM hooks
+			 * have only void and int return types.
+			 */
+			if (!t)
+				return true;
+			t = btf_type_by_id(btf, t->type);
+			break;
+		case BPF_MODIFY_RETURN:
+			/* For now the BPF_MODIFY_RETURN can only be attached to
+			 * functions that return an int.
+			 */
+			if (!t)
+				return false;
+
+			t = btf_type_skip_modifiers(btf, t->type, NULL);
+			if (!btf_type_is_small_int(t)) {
+				bpf_log(log,
+					"ret type %s not allowed for fmod_ret\n",
+					btf_kind_str[BTF_INFO_KIND(t->info)]);
+				return false;
+			}
+			break;
+		default:
+			bpf_log(log, "func '%s' doesn't have %d-th argument\n",
+				tname, arg + 1);
+			return false;
+		}
+	} else {
+		if (!t)
+			/* Default prog with 5 args */
+			return true;
+		t = btf_type_by_id(btf, args[arg].type);
+	}
+
+	/* skip modifiers */
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (btf_type_is_small_int(t) || btf_type_is_enum(t))
+		/* accessing a scalar */
+		return true;
+	if (!btf_type_is_ptr(t)) {
+		bpf_log(log,
+			"func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
+			tname, arg,
+			__btf_name_by_offset(btf, t->name_off),
+			btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return false;
+	}
+
+	/* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */
+	for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
+		const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
+
+		if (ctx_arg_info->offset == off &&
+		    (ctx_arg_info->reg_type == PTR_TO_RDONLY_BUF_OR_NULL ||
+		     ctx_arg_info->reg_type == PTR_TO_RDWR_BUF_OR_NULL)) {
+			info->reg_type = ctx_arg_info->reg_type;
+			return true;
+		}
+	}
+
+	if (t->type == 0)
+		/* This is a pointer to void.
+		 * It is the same as scalar from the verifier safety pov.
+		 * No further pointer walking is allowed.
+		 */
+		return true;
+
+	if (is_string_ptr(btf, t))
+		return true;
+
+	/* this is a pointer to another type */
+	for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
+		const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
+
+		if (ctx_arg_info->offset == off) {
+			info->reg_type = ctx_arg_info->reg_type;
+			info->btf_id = ctx_arg_info->btf_id;
+			return true;
+		}
+	}
+
+	info->reg_type = PTR_TO_BTF_ID;
+	if (tgt_prog) {
+		enum bpf_prog_type tgt_type;
+
+		if (tgt_prog->type == BPF_PROG_TYPE_EXT)
+			tgt_type = tgt_prog->aux->saved_dst_prog_type;
+		else
+			tgt_type = tgt_prog->type;
+
+		ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg);
+		if (ret > 0) {
+			info->btf_id = ret;
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	info->btf_id = t->type;
+	t = btf_type_by_id(btf, t->type);
+	/* skip modifiers */
+	while (btf_type_is_modifier(t)) {
+		info->btf_id = t->type;
+		t = btf_type_by_id(btf, t->type);
+	}
+	if (!btf_type_is_struct(t)) {
+		bpf_log(log,
+			"func '%s' arg%d type %s is not a struct\n",
+			tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return false;
+	}
+	bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
+		tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
+		__btf_name_by_offset(btf, t->name_off));
+	return true;
+}
+
+enum bpf_struct_walk_result {
+	/* < 0 error */
+	WALK_SCALAR = 0,
+	WALK_PTR,
+	WALK_STRUCT,
+};
+
+static int btf_struct_walk(struct bpf_verifier_log *log,
+			   const struct btf_type *t, int off, int size,
+			   u32 *next_btf_id)
+{
+	u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
+	const struct btf_type *mtype, *elem_type = NULL;
+	const struct btf_member *member;
+	const char *tname, *mname;
+	u32 vlen, elem_id, mid;
+
+again:
+	tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
+	if (!btf_type_is_struct(t)) {
+		bpf_log(log, "Type '%s' is not a struct\n", tname);
+		return -EINVAL;
+	}
+
+	vlen = btf_type_vlen(t);
+	if (off + size > t->size) {
+		/* If the last element is a variable size array, we may
+		 * need to relax the rule.
+		 */
+		struct btf_array *array_elem;
+
+		if (vlen == 0)
+			goto error;
+
+		member = btf_type_member(t) + vlen - 1;
+		mtype = btf_type_skip_modifiers(btf_vmlinux, member->type,
+						NULL);
+		if (!btf_type_is_array(mtype))
+			goto error;
+
+		array_elem = (struct btf_array *)(mtype + 1);
+		if (array_elem->nelems != 0)
+			goto error;
+
+		moff = btf_member_bit_offset(t, member) / 8;
+		if (off < moff)
+			goto error;
+
+		/* Only allow structure for now, can be relaxed for
+		 * other types later.
+		 */
+		t = btf_type_skip_modifiers(btf_vmlinux, array_elem->type,
+					    NULL);
+		if (!btf_type_is_struct(t))
+			goto error;
+
+		off = (off - moff) % t->size;
+		goto again;
+
+error:
+		bpf_log(log, "access beyond struct %s at off %u size %u\n",
+			tname, off, size);
+		return -EACCES;
+	}
+
+	for_each_member(i, t, member) {
+		/* offset of the field in bytes */
+		moff = btf_member_bit_offset(t, member) / 8;
+		if (off + size <= moff)
+			/* won't find anything, field is already too far */
+			break;
+
+		if (btf_member_bitfield_size(t, member)) {
+			u32 end_bit = btf_member_bit_offset(t, member) +
+				btf_member_bitfield_size(t, member);
+
+			/* off <= moff instead of off == moff because clang
+			 * does not generate a BTF member for anonymous
+			 * bitfield like the ":16" here:
+			 * struct {
+			 *	int :16;
+			 *	int x:8;
+			 * };
+			 */
+			if (off <= moff &&
+			    BITS_ROUNDUP_BYTES(end_bit) <= off + size)
+				return WALK_SCALAR;
+
+			/* off may be accessing a following member
+			 *
+			 * or
+			 *
+			 * Doing partial access at either end of this
+			 * bitfield.  Continue on this case also to
+			 * treat it as not accessing this bitfield
+			 * and eventually error out as field not
+			 * found to keep it simple.
+			 * It could be relaxed if there was a legit
+			 * partial access case later.
+			 */
+			continue;
+		}
+
+		/* In case of "off" is pointing to holes of a struct */
+		if (off < moff)
+			break;
+
+		/* type of the field */
+		mid = member->type;
+		mtype = btf_type_by_id(btf_vmlinux, member->type);
+		mname = __btf_name_by_offset(btf_vmlinux, member->name_off);
+
+		mtype = __btf_resolve_size(btf_vmlinux, mtype, &msize,
+					   &elem_type, &elem_id, &total_nelems,
+					   &mid);
+		if (IS_ERR(mtype)) {
+			bpf_log(log, "field %s doesn't have size\n", mname);
+			return -EFAULT;
+		}
+
+		mtrue_end = moff + msize;
+		if (off >= mtrue_end)
+			/* no overlap with member, keep iterating */
+			continue;
+
+		if (btf_type_is_array(mtype)) {
+			u32 elem_idx;
+
+			/* __btf_resolve_size() above helps to
+			 * linearize a multi-dimensional array.
+			 *
+			 * The logic here is treating an array
+			 * in a struct as the following way:
+			 *
+			 * struct outer {
+			 *	struct inner array[2][2];
+			 * };
+			 *
+			 * looks like:
+			 *
+			 * struct outer {
+			 *	struct inner array_elem0;
+			 *	struct inner array_elem1;
+			 *	struct inner array_elem2;
+			 *	struct inner array_elem3;
+			 * };
+			 *
+			 * When accessing outer->array[1][0], it moves
+			 * moff to "array_elem2", set mtype to
+			 * "struct inner", and msize also becomes
+			 * sizeof(struct inner).  Then most of the
+			 * remaining logic will fall through without
+			 * caring the current member is an array or
+			 * not.
+			 *
+			 * Unlike mtype/msize/moff, mtrue_end does not
+			 * change.  The naming difference ("_true") tells
+			 * that it is not always corresponding to
+			 * the current mtype/msize/moff.
+			 * It is the true end of the current
+			 * member (i.e. array in this case).  That
+			 * will allow an int array to be accessed like
+			 * a scratch space,
+			 * i.e. allow access beyond the size of
+			 *      the array's element as long as it is
+			 *      within the mtrue_end boundary.
+			 */
+
+			/* skip empty array */
+			if (moff == mtrue_end)
+				continue;
+
+			msize /= total_nelems;
+			elem_idx = (off - moff) / msize;
+			moff += elem_idx * msize;
+			mtype = elem_type;
+			mid = elem_id;
+		}
+
+		/* the 'off' we're looking for is either equal to start
+		 * of this field or inside of this struct
+		 */
+		if (btf_type_is_struct(mtype)) {
+			/* our field must be inside that union or struct */
+			t = mtype;
+
+			/* return if the offset matches the member offset */
+			if (off == moff) {
+				*next_btf_id = mid;
+				return WALK_STRUCT;
+			}
+
+			/* adjust offset we're looking for */
+			off -= moff;
+			goto again;
+		}
+
+		if (btf_type_is_ptr(mtype)) {
+			const struct btf_type *stype;
+			u32 id;
+
+			if (msize != size || off != moff) {
+				bpf_log(log,
+					"cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
+					mname, moff, tname, off, size);
+				return -EACCES;
+			}
+			stype = btf_type_skip_modifiers(btf_vmlinux, mtype->type, &id);
+			if (btf_type_is_struct(stype)) {
+				*next_btf_id = id;
+				return WALK_PTR;
+			}
+		}
+
+		/* Allow more flexible access within an int as long as
+		 * it is within mtrue_end.
+		 * Since mtrue_end could be the end of an array,
+		 * that also allows using an array of int as a scratch
+		 * space. e.g. skb->cb[].
+		 */
+		if (off + size > mtrue_end) {
+			bpf_log(log,
+				"access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
+				mname, mtrue_end, tname, off, size);
+			return -EACCES;
+		}
+
+		return WALK_SCALAR;
+	}
+	bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
+	return -EINVAL;
+}
+
+int btf_struct_access(struct bpf_verifier_log *log,
+		      const struct btf_type *t, int off, int size,
+		      enum bpf_access_type atype __maybe_unused,
+		      u32 *next_btf_id)
+{
+	int err;
+	u32 id;
+
+	do {
+		err = btf_struct_walk(log, t, off, size, &id);
+
+		switch (err) {
+		case WALK_PTR:
+			/* If we found the pointer or scalar on t+off,
+			 * we're done.
+			 */
+			*next_btf_id = id;
+			return PTR_TO_BTF_ID;
+		case WALK_SCALAR:
+			return SCALAR_VALUE;
+		case WALK_STRUCT:
+			/* We found nested struct, so continue the search
+			 * by diving in it. At this point the offset is
+			 * aligned with the new type, so set it to 0.
+			 */
+			t = btf_type_by_id(btf_vmlinux, id);
+			off = 0;
+			break;
+		default:
+			/* It's either error or unknown return value..
+			 * scream and leave.
+			 */
+			if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value"))
+				return -EINVAL;
+			return err;
+		}
+	} while (t);
+
+	return -EINVAL;
+}
+
+bool btf_struct_ids_match(struct bpf_verifier_log *log,
+			  int off, u32 id, u32 need_type_id)
+{
+	const struct btf_type *type;
+	int err;
+
+	/* Are we already done? */
+	if (need_type_id == id && off == 0)
+		return true;
+
+again:
+	type = btf_type_by_id(btf_vmlinux, id);
+	if (!type)
+		return false;
+	err = btf_struct_walk(log, type, off, 1, &id);
+	if (err != WALK_STRUCT)
+		return false;
+
+	/* We found nested struct object. If it matches
+	 * the requested ID, we're done. Otherwise let's
+	 * continue the search with offset 0 in the new
+	 * type.
+	 */
+	if (need_type_id != id) {
+		off = 0;
+		goto again;
+	}
+
+	return true;
+}
+
+static int __get_type_size(struct btf *btf, u32 btf_id,
+			   const struct btf_type **bad_type)
+{
+	const struct btf_type *t;
+
+	if (!btf_id)
+		/* void */
+		return 0;
+	t = btf_type_by_id(btf, btf_id);
+	while (t && btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!t) {
+		*bad_type = btf->types[0];
+		return -EINVAL;
+	}
+	if (btf_type_is_ptr(t))
+		/* kernel size of pointer. Not BPF's size of pointer*/
+		return sizeof(void *);
+	if (btf_type_is_int(t) || btf_type_is_enum(t))
+		return t->size;
+	*bad_type = t;
+	return -EINVAL;
+}
+
+int btf_distill_func_proto(struct bpf_verifier_log *log,
+			   struct btf *btf,
+			   const struct btf_type *func,
+			   const char *tname,
+			   struct btf_func_model *m)
+{
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs;
+	int ret;
+
+	if (!func) {
+		/* BTF function prototype doesn't match the verifier types.
+		 * Fall back to 5 u64 args.
+		 */
+		for (i = 0; i < 5; i++)
+			m->arg_size[i] = 8;
+		m->ret_size = 8;
+		m->nr_args = 5;
+		return 0;
+	}
+	args = (const struct btf_param *)(func + 1);
+	nargs = btf_type_vlen(func);
+	if (nargs >= MAX_BPF_FUNC_ARGS) {
+		bpf_log(log,
+			"The function %s has %d arguments. Too many.\n",
+			tname, nargs);
+		return -EINVAL;
+	}
+	ret = __get_type_size(btf, func->type, &t);
+	if (ret < 0) {
+		bpf_log(log,
+			"The function %s return type %s is unsupported.\n",
+			tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return -EINVAL;
+	}
+	m->ret_size = ret;
+
+	for (i = 0; i < nargs; i++) {
+		if (i == nargs - 1 && args[i].type == 0) {
+			bpf_log(log,
+				"The function %s with variable args is unsupported.\n",
+				tname);
+			return -EINVAL;
+		}
+		ret = __get_type_size(btf, args[i].type, &t);
+		if (ret < 0) {
+			bpf_log(log,
+				"The function %s arg%d type %s is unsupported.\n",
+				tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+			return -EINVAL;
+		}
+		if (ret == 0) {
+			bpf_log(log,
+				"The function %s has malformed void argument.\n",
+				tname);
+			return -EINVAL;
+		}
+		m->arg_size[i] = ret;
+	}
+	m->nr_args = nargs;
+	return 0;
+}
+
+/* Compare BTFs of two functions assuming only scalars and pointers to context.
+ * t1 points to BTF_KIND_FUNC in btf1
+ * t2 points to BTF_KIND_FUNC in btf2
+ * Returns:
+ * EINVAL - function prototype mismatch
+ * EFAULT - verifier bug
+ * 0 - 99% match. The last 1% is validated by the verifier.
+ */
+static int btf_check_func_type_match(struct bpf_verifier_log *log,
+				     struct btf *btf1, const struct btf_type *t1,
+				     struct btf *btf2, const struct btf_type *t2)
+{
+	const struct btf_param *args1, *args2;
+	const char *fn1, *fn2, *s1, *s2;
+	u32 nargs1, nargs2, i;
+
+	fn1 = btf_name_by_offset(btf1, t1->name_off);
+	fn2 = btf_name_by_offset(btf2, t2->name_off);
+
+	if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) {
+		bpf_log(log, "%s() is not a global function\n", fn1);
+		return -EINVAL;
+	}
+	if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) {
+		bpf_log(log, "%s() is not a global function\n", fn2);
+		return -EINVAL;
+	}
+
+	t1 = btf_type_by_id(btf1, t1->type);
+	if (!t1 || !btf_type_is_func_proto(t1))
+		return -EFAULT;
+	t2 = btf_type_by_id(btf2, t2->type);
+	if (!t2 || !btf_type_is_func_proto(t2))
+		return -EFAULT;
+
+	args1 = (const struct btf_param *)(t1 + 1);
+	nargs1 = btf_type_vlen(t1);
+	args2 = (const struct btf_param *)(t2 + 1);
+	nargs2 = btf_type_vlen(t2);
+
+	if (nargs1 != nargs2) {
+		bpf_log(log, "%s() has %d args while %s() has %d args\n",
+			fn1, nargs1, fn2, nargs2);
+		return -EINVAL;
+	}
+
+	t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
+	t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
+	if (t1->info != t2->info) {
+		bpf_log(log,
+			"Return type %s of %s() doesn't match type %s of %s()\n",
+			btf_type_str(t1), fn1,
+			btf_type_str(t2), fn2);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < nargs1; i++) {
+		t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL);
+		t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL);
+
+		if (t1->info != t2->info) {
+			bpf_log(log, "arg%d in %s() is %s while %s() has %s\n",
+				i, fn1, btf_type_str(t1),
+				fn2, btf_type_str(t2));
+			return -EINVAL;
+		}
+		if (btf_type_has_size(t1) && t1->size != t2->size) {
+			bpf_log(log,
+				"arg%d in %s() has size %d while %s() has %d\n",
+				i, fn1, t1->size,
+				fn2, t2->size);
+			return -EINVAL;
+		}
+
+		/* global functions are validated with scalars and pointers
+		 * to context only. And only global functions can be replaced.
+		 * Hence type check only those types.
+		 */
+		if (btf_type_is_int(t1) || btf_type_is_enum(t1))
+			continue;
+		if (!btf_type_is_ptr(t1)) {
+			bpf_log(log,
+				"arg%d in %s() has unrecognized type\n",
+				i, fn1);
+			return -EINVAL;
+		}
+		t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
+		t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
+		if (!btf_type_is_struct(t1)) {
+			bpf_log(log,
+				"arg%d in %s() is not a pointer to context\n",
+				i, fn1);
+			return -EINVAL;
+		}
+		if (!btf_type_is_struct(t2)) {
+			bpf_log(log,
+				"arg%d in %s() is not a pointer to context\n",
+				i, fn2);
+			return -EINVAL;
+		}
+		/* This is an optional check to make program writing easier.
+		 * Compare names of structs and report an error to the user.
+		 * btf_prepare_func_args() already checked that t2 struct
+		 * is a context type. btf_prepare_func_args() will check
+		 * later that t1 struct is a context type as well.
+		 */
+		s1 = btf_name_by_offset(btf1, t1->name_off);
+		s2 = btf_name_by_offset(btf2, t2->name_off);
+		if (strcmp(s1, s2)) {
+			bpf_log(log,
+				"arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
+				i, fn1, s1, fn2, s2);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+/* Compare BTFs of given program with BTF of target program */
+int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,
+			 struct btf *btf2, const struct btf_type *t2)
+{
+	struct btf *btf1 = prog->aux->btf;
+	const struct btf_type *t1;
+	u32 btf_id = 0;
+
+	if (!prog->aux->func_info) {
+		bpf_log(log, "Program extension requires BTF\n");
+		return -EINVAL;
+	}
+
+	btf_id = prog->aux->func_info[0].type_id;
+	if (!btf_id)
+		return -EFAULT;
+
+	t1 = btf_type_by_id(btf1, btf_id);
+	if (!t1 || !btf_type_is_func(t1))
+		return -EFAULT;
+
+	return btf_check_func_type_match(log, btf1, t1, btf2, t2);
+}
+
+/* Compare BTF of a function with given bpf_reg_state.
+ * Returns:
+ * EFAULT - there is a verifier bug. Abort verification.
+ * EINVAL - there is a type mismatch or BTF is not available.
+ * 0 - BTF matches with what bpf_reg_state expects.
+ * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
+ */
+int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
+			     struct bpf_reg_state *reg)
+{
+	struct bpf_verifier_log *log = &env->log;
+	struct bpf_prog *prog = env->prog;
+	struct btf *btf = prog->aux->btf;
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs, btf_id;
+	const char *tname;
+
+	if (!prog->aux->func_info)
+		return -EINVAL;
+
+	btf_id = prog->aux->func_info[subprog].type_id;
+	if (!btf_id)
+		return -EFAULT;
+
+	if (prog->aux->func_info_aux[subprog].unreliable)
+		return -EINVAL;
+
+	t = btf_type_by_id(btf, btf_id);
+	if (!t || !btf_type_is_func(t)) {
+		/* These checks were already done by the verifier while loading
+		 * struct bpf_func_info
+		 */
+		bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
+			subprog);
+		return -EFAULT;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+
+	t = btf_type_by_id(btf, t->type);
+	if (!t || !btf_type_is_func_proto(t)) {
+		bpf_log(log, "Invalid BTF of func %s\n", tname);
+		return -EFAULT;
+	}
+	args = (const struct btf_param *)(t + 1);
+	nargs = btf_type_vlen(t);
+	if (nargs > 5) {
+		bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
+		goto out;
+	}
+	/* check that BTF function arguments match actual types that the
+	 * verifier sees.
+	 */
+	for (i = 0; i < nargs; i++) {
+		t = btf_type_by_id(btf, args[i].type);
+		while (btf_type_is_modifier(t))
+			t = btf_type_by_id(btf, t->type);
+		if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+			if (reg[i + 1].type == SCALAR_VALUE)
+				continue;
+			bpf_log(log, "R%d is not a scalar\n", i + 1);
+			goto out;
+		}
+		if (btf_type_is_ptr(t)) {
+			if (reg[i + 1].type == SCALAR_VALUE) {
+				bpf_log(log, "R%d is not a pointer\n", i + 1);
+				goto out;
+			}
+			/* If function expects ctx type in BTF check that caller
+			 * is passing PTR_TO_CTX.
+			 */
+			if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) {
+				if (reg[i + 1].type != PTR_TO_CTX) {
+					bpf_log(log,
+						"arg#%d expected pointer to ctx, but got %s\n",
+						i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+					goto out;
+				}
+				if (check_ctx_reg(env, &reg[i + 1], i + 1))
+					goto out;
+				continue;
+			}
+		}
+		bpf_log(log, "Unrecognized arg#%d type %s\n",
+			i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		goto out;
+	}
+	return 0;
+out:
+	/* Compiler optimizations can remove arguments from static functions
+	 * or mismatched type can be passed into a global function.
+	 * In such cases mark the function as unreliable from BTF point of view.
+	 */
+	prog->aux->func_info_aux[subprog].unreliable = true;
+	return -EINVAL;
+}
+
+/* Convert BTF of a function into bpf_reg_state if possible
+ * Returns:
+ * EFAULT - there is a verifier bug. Abort verification.
+ * EINVAL - cannot convert BTF.
+ * 0 - Successfully converted BTF into bpf_reg_state
+ * (either PTR_TO_CTX or SCALAR_VALUE).
+ */
+int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
+			  struct bpf_reg_state *reg)
+{
+	struct bpf_verifier_log *log = &env->log;
+	struct bpf_prog *prog = env->prog;
+	enum bpf_prog_type prog_type = prog->type;
+	struct btf *btf = prog->aux->btf;
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs, btf_id;
+	const char *tname;
+
+	if (!prog->aux->func_info ||
+	    prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
+		bpf_log(log, "Verifier bug\n");
+		return -EFAULT;
+	}
+
+	btf_id = prog->aux->func_info[subprog].type_id;
+	if (!btf_id) {
+		bpf_log(log, "Global functions need valid BTF\n");
+		return -EFAULT;
+	}
+
+	t = btf_type_by_id(btf, btf_id);
+	if (!t || !btf_type_is_func(t)) {
+		/* These checks were already done by the verifier while loading
+		 * struct bpf_func_info
+		 */
+		bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
+			subprog);
+		return -EFAULT;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+
+	if (log->level & BPF_LOG_LEVEL)
+		bpf_log(log, "Validating %s() func#%d...\n",
+			tname, subprog);
+
+	if (prog->aux->func_info_aux[subprog].unreliable) {
+		bpf_log(log, "Verifier bug in function %s()\n", tname);
+		return -EFAULT;
+	}
+	if (prog_type == BPF_PROG_TYPE_EXT)
+		prog_type = prog->aux->dst_prog->type;
+
+	t = btf_type_by_id(btf, t->type);
+	if (!t || !btf_type_is_func_proto(t)) {
+		bpf_log(log, "Invalid type of function %s()\n", tname);
+		return -EFAULT;
+	}
+	args = (const struct btf_param *)(t + 1);
+	nargs = btf_type_vlen(t);
+	if (nargs > 5) {
+		bpf_log(log, "Global function %s() with %d > 5 args. Buggy compiler.\n",
+			tname, nargs);
+		return -EINVAL;
+	}
+	/* check that function returns int */
+	t = btf_type_by_id(btf, t->type);
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!btf_type_is_int(t) && !btf_type_is_enum(t)) {
+		bpf_log(log,
+			"Global function %s() doesn't return scalar. Only those are supported.\n",
+			tname);
+		return -EINVAL;
+	}
+	/* Convert BTF function arguments into verifier types.
+	 * Only PTR_TO_CTX and SCALAR are supported atm.
+	 */
+	for (i = 0; i < nargs; i++) {
+		t = btf_type_by_id(btf, args[i].type);
+		while (btf_type_is_modifier(t))
+			t = btf_type_by_id(btf, t->type);
+		if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+			reg[i + 1].type = SCALAR_VALUE;
+			continue;
+		}
+		if (btf_type_is_ptr(t) &&
+		    btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
+			reg[i + 1].type = PTR_TO_CTX;
+			continue;
+		}
+		bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
+			i, btf_kind_str[BTF_INFO_KIND(t->info)], tname);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
+			  struct btf_show *show)
 {
 	const struct btf_type *t = btf_type_by_id(btf, type_id);
 
-	btf_type_ops(t)->seq_show(btf, t, type_id, obj, 0, m);
+	show->btf = btf;
+	memset(&show->state, 0, sizeof(show->state));
+	memset(&show->obj, 0, sizeof(show->obj));
+
+	btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
+}
+
+static void btf_seq_show(struct btf_show *show, const char *fmt,
+			 va_list args)
+{
+	seq_vprintf((struct seq_file *)show->target, fmt, args);
+}
+
+int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
+			    void *obj, struct seq_file *m, u64 flags)
+{
+	struct btf_show sseq;
+
+	sseq.target = m;
+	sseq.showfn = btf_seq_show;
+	sseq.flags = flags;
+
+	btf_type_show(btf, type_id, obj, &sseq);
+
+	return sseq.state.status;
+}
+
+void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
+		       struct seq_file *m)
+{
+	(void) btf_type_seq_show_flags(btf, type_id, obj, m,
+				       BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
+				       BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
+}
+
+struct btf_show_snprintf {
+	struct btf_show show;
+	int len_left;		/* space left in string */
+	int len;		/* length we would have written */
+};
+
+static void btf_snprintf_show(struct btf_show *show, const char *fmt,
+			      va_list args)
+{
+	struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
+	int len;
+
+	len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
+
+	if (len < 0) {
+		ssnprintf->len_left = 0;
+		ssnprintf->len = len;
+	} else if (len > ssnprintf->len_left) {
+		/* no space, drive on to get length we would have written */
+		ssnprintf->len_left = 0;
+		ssnprintf->len += len;
+	} else {
+		ssnprintf->len_left -= len;
+		ssnprintf->len += len;
+		show->target += len;
+	}
+}
+
+int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
+			   char *buf, int len, u64 flags)
+{
+	struct btf_show_snprintf ssnprintf;
+
+	ssnprintf.show.target = buf;
+	ssnprintf.show.flags = flags;
+	ssnprintf.show.showfn = btf_snprintf_show;
+	ssnprintf.len_left = len;
+	ssnprintf.len = 0;
+
+	btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf);
+
+	/* If we encontered an error, return it. */
+	if (ssnprintf.show.state.status)
+		return ssnprintf.show.state.status;
+
+	/* Otherwise return length we would have written */
+	return ssnprintf.len;
 }
 
 #ifdef CONFIG_PROC_FS
@@ -3512,3 +5547,15 @@
 {
 	return btf->id;
 }
+
+static int btf_id_cmp_func(const void *a, const void *b)
+{
+	const int *pa = a, *pb = b;
+
+	return *pa - *pb;
+}
+
+bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
+{
+	return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
+}
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index c2f0aa8..6aa9e10 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -28,6 +28,78 @@
 	percpu_ref_kill(&cgrp->bpf.refcnt);
 }
 
+static void bpf_cgroup_storages_free(struct bpf_cgroup_storage *storages[])
+{
+	enum bpf_cgroup_storage_type stype;
+
+	for_each_cgroup_storage_type(stype)
+		bpf_cgroup_storage_free(storages[stype]);
+}
+
+static int bpf_cgroup_storages_alloc(struct bpf_cgroup_storage *storages[],
+				     struct bpf_cgroup_storage *new_storages[],
+				     enum bpf_attach_type type,
+				     struct bpf_prog *prog,
+				     struct cgroup *cgrp)
+{
+	enum bpf_cgroup_storage_type stype;
+	struct bpf_cgroup_storage_key key;
+	struct bpf_map *map;
+
+	key.cgroup_inode_id = cgroup_id(cgrp);
+	key.attach_type = type;
+
+	for_each_cgroup_storage_type(stype) {
+		map = prog->aux->cgroup_storage[stype];
+		if (!map)
+			continue;
+
+		storages[stype] = cgroup_storage_lookup((void *)map, &key, false);
+		if (storages[stype])
+			continue;
+
+		storages[stype] = bpf_cgroup_storage_alloc(prog, stype);
+		if (IS_ERR(storages[stype])) {
+			bpf_cgroup_storages_free(new_storages);
+			return -ENOMEM;
+		}
+
+		new_storages[stype] = storages[stype];
+	}
+
+	return 0;
+}
+
+static void bpf_cgroup_storages_assign(struct bpf_cgroup_storage *dst[],
+				       struct bpf_cgroup_storage *src[])
+{
+	enum bpf_cgroup_storage_type stype;
+
+	for_each_cgroup_storage_type(stype)
+		dst[stype] = src[stype];
+}
+
+static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[],
+				     struct cgroup *cgrp,
+				     enum bpf_attach_type attach_type)
+{
+	enum bpf_cgroup_storage_type stype;
+
+	for_each_cgroup_storage_type(stype)
+		bpf_cgroup_storage_link(storages[stype], cgrp, attach_type);
+}
+
+/* Called when bpf_cgroup_link is auto-detached from dying cgroup.
+ * It drops cgroup and bpf_prog refcounts, and marks bpf_link as defunct. It
+ * doesn't free link memory, which will eventually be done by bpf_link's
+ * release() callback, when its last FD is closed.
+ */
+static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link)
+{
+	cgroup_put(link->cgroup);
+	link->cgroup = NULL;
+}
+
 /**
  * cgroup_bpf_release() - put references of all bpf programs and
  *                        release all cgroup bpf data
@@ -37,23 +109,24 @@
 {
 	struct cgroup *p, *cgrp = container_of(work, struct cgroup,
 					       bpf.release_work);
-	enum bpf_cgroup_storage_type stype;
 	struct bpf_prog_array *old_array;
+	struct list_head *storages = &cgrp->bpf.storages;
+	struct bpf_cgroup_storage *storage, *stmp;
+
 	unsigned int type;
 
 	mutex_lock(&cgroup_mutex);
 
 	for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) {
 		struct list_head *progs = &cgrp->bpf.progs[type];
-		struct bpf_prog_list *pl, *tmp;
+		struct bpf_prog_list *pl, *pltmp;
 
-		list_for_each_entry_safe(pl, tmp, progs, node) {
+		list_for_each_entry_safe(pl, pltmp, progs, node) {
 			list_del(&pl->node);
-			bpf_prog_put(pl->prog);
-			for_each_cgroup_storage_type(stype) {
-				bpf_cgroup_storage_unlink(pl->storage[stype]);
-				bpf_cgroup_storage_free(pl->storage[stype]);
-			}
+			if (pl->prog)
+				bpf_prog_put(pl->prog);
+			if (pl->link)
+				bpf_cgroup_link_auto_detach(pl->link);
 			kfree(pl);
 			static_branch_dec(&cgroup_bpf_enabled_key);
 		}
@@ -63,6 +136,11 @@
 		bpf_prog_array_free(old_array);
 	}
 
+	list_for_each_entry_safe(storage, stmp, storages, list_cg) {
+		bpf_cgroup_storage_unlink(storage);
+		bpf_cgroup_storage_free(storage);
+	}
+
 	mutex_unlock(&cgroup_mutex);
 
 	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
@@ -85,6 +163,18 @@
 	queue_work(system_wq, &cgrp->bpf.release_work);
 }
 
+/* Get underlying bpf_prog of bpf_prog_list entry, regardless if it's through
+ * link or direct prog.
+ */
+static struct bpf_prog *prog_list_prog(struct bpf_prog_list *pl)
+{
+	if (pl->prog)
+		return pl->prog;
+	if (pl->link)
+		return pl->link->link.prog;
+	return NULL;
+}
+
 /* count number of elements in the list.
  * it's slow but the list cannot be long
  */
@@ -94,7 +184,7 @@
 	u32 cnt = 0;
 
 	list_for_each_entry(pl, head, node) {
-		if (!pl->prog)
+		if (!prog_list_prog(pl))
 			continue;
 		cnt++;
 	}
@@ -106,8 +196,7 @@
  * if parent has overridable or multi-prog, allow attaching
  */
 static bool hierarchy_allows_attach(struct cgroup *cgrp,
-				    enum bpf_attach_type type,
-				    u32 new_flags)
+				    enum bpf_attach_type type)
 {
 	struct cgroup *p;
 
@@ -139,7 +228,7 @@
 				   enum bpf_attach_type type,
 				   struct bpf_prog_array **array)
 {
-	enum bpf_cgroup_storage_type stype;
+	struct bpf_prog_array_item *item;
 	struct bpf_prog_array *progs;
 	struct bpf_prog_list *pl;
 	struct cgroup *p = cgrp;
@@ -164,13 +253,13 @@
 			continue;
 
 		list_for_each_entry(pl, &p->bpf.progs[type], node) {
-			if (!pl->prog)
+			if (!prog_list_prog(pl))
 				continue;
 
-			progs->items[cnt].prog = pl->prog;
-			for_each_cgroup_storage_type(stype)
-				progs->items[cnt].cgroup_storage[stype] =
-					pl->storage[stype];
+			item = &progs->items[cnt];
+			item->prog = prog_list_prog(pl);
+			bpf_cgroup_storages_assign(item->cgroup_storage,
+						   pl->storage);
 			cnt++;
 		}
 	} while ((p = cgroup_parent(p)));
@@ -183,8 +272,8 @@
 				     enum bpf_attach_type type,
 				     struct bpf_prog_array *old_array)
 {
-	rcu_swap_protected(cgrp->bpf.effective[type], old_array,
-			   lockdep_is_held(&cgroup_mutex));
+	old_array = rcu_replace_pointer(cgrp->bpf.effective[type], old_array,
+					lockdep_is_held(&cgroup_mutex));
 	/* free prog array after grace period, since __cgroup_bpf_run_*()
 	 * might be still walking the array
 	 */
@@ -216,6 +305,8 @@
 	for (i = 0; i < NR; i++)
 		INIT_LIST_HEAD(&cgrp->bpf.progs[i]);
 
+	INIT_LIST_HEAD(&cgrp->bpf.storages);
+
 	for (i = 0; i < NR; i++)
 		if (compute_effective_progs(cgrp, i, &arrays[i]))
 			goto cleanup;
@@ -288,36 +379,85 @@
 
 #define BPF_CGROUP_MAX_PROGS 64
 
+static struct bpf_prog_list *find_attach_entry(struct list_head *progs,
+					       struct bpf_prog *prog,
+					       struct bpf_cgroup_link *link,
+					       struct bpf_prog *replace_prog,
+					       bool allow_multi)
+{
+	struct bpf_prog_list *pl;
+
+	/* single-attach case */
+	if (!allow_multi) {
+		if (list_empty(progs))
+			return NULL;
+		return list_first_entry(progs, typeof(*pl), node);
+	}
+
+	list_for_each_entry(pl, progs, node) {
+		if (prog && pl->prog == prog && prog != replace_prog)
+			/* disallow attaching the same prog twice */
+			return ERR_PTR(-EINVAL);
+		if (link && pl->link == link)
+			/* disallow attaching the same link twice */
+			return ERR_PTR(-EINVAL);
+	}
+
+	/* direct prog multi-attach w/ replacement case */
+	if (replace_prog) {
+		list_for_each_entry(pl, progs, node) {
+			if (pl->prog == replace_prog)
+				/* a match found */
+				return pl;
+		}
+		/* prog to replace not found for cgroup */
+		return ERR_PTR(-ENOENT);
+	}
+
+	return NULL;
+}
+
 /**
- * __cgroup_bpf_attach() - Attach the program to a cgroup, and
+ * __cgroup_bpf_attach() - Attach the program or the link to a cgroup, and
  *                         propagate the change to descendants
  * @cgrp: The cgroup which descendants to traverse
  * @prog: A program to attach
+ * @link: A link to attach
+ * @replace_prog: Previously attached program to replace if BPF_F_REPLACE is set
  * @type: Type of attach operation
  * @flags: Option flags
  *
+ * Exactly one of @prog or @link can be non-null.
  * Must be called with cgroup_mutex held.
  */
-int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
+int __cgroup_bpf_attach(struct cgroup *cgrp,
+			struct bpf_prog *prog, struct bpf_prog *replace_prog,
+			struct bpf_cgroup_link *link,
 			enum bpf_attach_type type, u32 flags)
 {
+	u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI));
 	struct list_head *progs = &cgrp->bpf.progs[type];
 	struct bpf_prog *old_prog = NULL;
 	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
-	struct bpf_cgroup_storage *old_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
-	enum bpf_cgroup_storage_type stype;
+	struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
 	struct bpf_prog_list *pl;
-	bool pl_was_allocated;
 	int err;
 
-	if ((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI))
+	if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) ||
+	    ((flags & BPF_F_REPLACE) && !(flags & BPF_F_ALLOW_MULTI)))
 		/* invalid combination */
 		return -EINVAL;
+	if (link && (prog || replace_prog))
+		/* only either link or prog/replace_prog can be specified */
+		return -EINVAL;
+	if (!!replace_prog != !!(flags & BPF_F_REPLACE))
+		/* replace_prog implies BPF_F_REPLACE, and vice versa */
+		return -EINVAL;
 
-	if (!hierarchy_allows_attach(cgrp, type, flags))
+	if (!hierarchy_allows_attach(cgrp, type))
 		return -EPERM;
 
-	if (!list_empty(progs) && cgrp->bpf.flags[type] != flags)
+	if (!list_empty(progs) && cgrp->bpf.flags[type] != saved_flags)
 		/* Disallow attaching non-overridable on top
 		 * of existing overridable in this cgroup.
 		 * Disallow attaching multi-prog if overridable or none
@@ -327,150 +467,224 @@
 	if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS)
 		return -E2BIG;
 
-	for_each_cgroup_storage_type(stype) {
-		storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
-		if (IS_ERR(storage[stype])) {
-			storage[stype] = NULL;
-			for_each_cgroup_storage_type(stype)
-				bpf_cgroup_storage_free(storage[stype]);
-			return -ENOMEM;
-		}
-	}
+	pl = find_attach_entry(progs, prog, link, replace_prog,
+			       flags & BPF_F_ALLOW_MULTI);
+	if (IS_ERR(pl))
+		return PTR_ERR(pl);
 
-	if (flags & BPF_F_ALLOW_MULTI) {
-		list_for_each_entry(pl, progs, node) {
-			if (pl->prog == prog) {
-				/* disallow attaching the same prog twice */
-				for_each_cgroup_storage_type(stype)
-					bpf_cgroup_storage_free(storage[stype]);
-				return -EINVAL;
-			}
-		}
+	if (bpf_cgroup_storages_alloc(storage, new_storage, type,
+				      prog ? : link->link.prog, cgrp))
+		return -ENOMEM;
 
+	if (pl) {
+		old_prog = pl->prog;
+	} else {
 		pl = kmalloc(sizeof(*pl), GFP_KERNEL);
 		if (!pl) {
-			for_each_cgroup_storage_type(stype)
-				bpf_cgroup_storage_free(storage[stype]);
+			bpf_cgroup_storages_free(new_storage);
 			return -ENOMEM;
 		}
-
-		pl_was_allocated = true;
-		pl->prog = prog;
-		for_each_cgroup_storage_type(stype)
-			pl->storage[stype] = storage[stype];
 		list_add_tail(&pl->node, progs);
-	} else {
-		if (list_empty(progs)) {
-			pl = kmalloc(sizeof(*pl), GFP_KERNEL);
-			if (!pl) {
-				for_each_cgroup_storage_type(stype)
-					bpf_cgroup_storage_free(storage[stype]);
-				return -ENOMEM;
-			}
-			pl_was_allocated = true;
-			list_add_tail(&pl->node, progs);
-		} else {
-			pl = list_first_entry(progs, typeof(*pl), node);
-			old_prog = pl->prog;
-			for_each_cgroup_storage_type(stype) {
-				old_storage[stype] = pl->storage[stype];
-				bpf_cgroup_storage_unlink(old_storage[stype]);
-			}
-			pl_was_allocated = false;
-		}
-		pl->prog = prog;
-		for_each_cgroup_storage_type(stype)
-			pl->storage[stype] = storage[stype];
 	}
 
-	cgrp->bpf.flags[type] = flags;
+	pl->prog = prog;
+	pl->link = link;
+	bpf_cgroup_storages_assign(pl->storage, storage);
+	cgrp->bpf.flags[type] = saved_flags;
 
 	err = update_effective_progs(cgrp, type);
 	if (err)
 		goto cleanup;
 
-	static_branch_inc(&cgroup_bpf_enabled_key);
-	for_each_cgroup_storage_type(stype) {
-		if (!old_storage[stype])
-			continue;
-		bpf_cgroup_storage_free(old_storage[stype]);
-	}
-	if (old_prog) {
+	if (old_prog)
 		bpf_prog_put(old_prog);
-		static_branch_dec(&cgroup_bpf_enabled_key);
-	}
-	for_each_cgroup_storage_type(stype)
-		bpf_cgroup_storage_link(storage[stype], cgrp, type);
+	else
+		static_branch_inc(&cgroup_bpf_enabled_key);
+	bpf_cgroup_storages_link(new_storage, cgrp, type);
 	return 0;
 
 cleanup:
-	/* and cleanup the prog list */
-	pl->prog = old_prog;
-	for_each_cgroup_storage_type(stype) {
-		bpf_cgroup_storage_free(pl->storage[stype]);
-		pl->storage[stype] = old_storage[stype];
-		bpf_cgroup_storage_link(old_storage[stype], cgrp, type);
+	if (old_prog) {
+		pl->prog = old_prog;
+		pl->link = NULL;
 	}
-	if (pl_was_allocated) {
+	bpf_cgroup_storages_free(new_storage);
+	if (!old_prog) {
 		list_del(&pl->node);
 		kfree(pl);
 	}
 	return err;
 }
 
+/* Swap updated BPF program for given link in effective program arrays across
+ * all descendant cgroups. This function is guaranteed to succeed.
+ */
+static void replace_effective_prog(struct cgroup *cgrp,
+				   enum bpf_attach_type type,
+				   struct bpf_cgroup_link *link)
+{
+	struct bpf_prog_array_item *item;
+	struct cgroup_subsys_state *css;
+	struct bpf_prog_array *progs;
+	struct bpf_prog_list *pl;
+	struct list_head *head;
+	struct cgroup *cg;
+	int pos;
+
+	css_for_each_descendant_pre(css, &cgrp->self) {
+		struct cgroup *desc = container_of(css, struct cgroup, self);
+
+		if (percpu_ref_is_zero(&desc->bpf.refcnt))
+			continue;
+
+		/* find position of link in effective progs array */
+		for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
+			if (pos && !(cg->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+				continue;
+
+			head = &cg->bpf.progs[type];
+			list_for_each_entry(pl, head, node) {
+				if (!prog_list_prog(pl))
+					continue;
+				if (pl->link == link)
+					goto found;
+				pos++;
+			}
+		}
+found:
+		BUG_ON(!cg);
+		progs = rcu_dereference_protected(
+				desc->bpf.effective[type],
+				lockdep_is_held(&cgroup_mutex));
+		item = &progs->items[pos];
+		WRITE_ONCE(item->prog, link->link.prog);
+	}
+}
+
 /**
- * __cgroup_bpf_detach() - Detach the program from a cgroup, and
- *                         propagate the change to descendants
+ * __cgroup_bpf_replace() - Replace link's program and propagate the change
+ *                          to descendants
  * @cgrp: The cgroup which descendants to traverse
- * @prog: A program to detach or NULL
- * @type: Type of detach operation
+ * @link: A link for which to replace BPF program
+ * @type: Type of attach operation
  *
  * Must be called with cgroup_mutex held.
  */
-int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
-			enum bpf_attach_type type)
+static int __cgroup_bpf_replace(struct cgroup *cgrp,
+				struct bpf_cgroup_link *link,
+				struct bpf_prog *new_prog)
 {
-	struct list_head *progs = &cgrp->bpf.progs[type];
-	enum bpf_cgroup_storage_type stype;
-	u32 flags = cgrp->bpf.flags[type];
-	struct bpf_prog *old_prog = NULL;
+	struct list_head *progs = &cgrp->bpf.progs[link->type];
+	struct bpf_prog *old_prog;
 	struct bpf_prog_list *pl;
-	int err;
+	bool found = false;
 
-	if (flags & BPF_F_ALLOW_MULTI) {
-		if (!prog)
-			/* to detach MULTI prog the user has to specify valid FD
-			 * of the program to be detached
-			 */
-			return -EINVAL;
-	} else {
-		if (list_empty(progs))
-			/* report error when trying to detach and nothing is attached */
-			return -ENOENT;
-	}
+	if (link->link.prog->type != new_prog->type)
+		return -EINVAL;
 
-	if (flags & BPF_F_ALLOW_MULTI) {
-		/* find the prog and detach it */
-		list_for_each_entry(pl, progs, node) {
-			if (pl->prog != prog)
-				continue;
-			old_prog = prog;
-			/* mark it deleted, so it's ignored while
-			 * recomputing effective
-			 */
-			pl->prog = NULL;
+	list_for_each_entry(pl, progs, node) {
+		if (pl->link == link) {
+			found = true;
 			break;
 		}
-		if (!old_prog)
-			return -ENOENT;
-	} else {
-		/* to maintain backward compatibility NONE and OVERRIDE cgroups
-		 * allow detaching with invalid FD (prog==NULL)
-		 */
-		pl = list_first_entry(progs, typeof(*pl), node);
-		old_prog = pl->prog;
-		pl->prog = NULL;
 	}
+	if (!found)
+		return -ENOENT;
+
+	old_prog = xchg(&link->link.prog, new_prog);
+	replace_effective_prog(cgrp, link->type, link);
+	bpf_prog_put(old_prog);
+	return 0;
+}
+
+static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,
+			      struct bpf_prog *old_prog)
+{
+	struct bpf_cgroup_link *cg_link;
+	int ret;
+
+	cg_link = container_of(link, struct bpf_cgroup_link, link);
+
+	mutex_lock(&cgroup_mutex);
+	/* link might have been auto-released by dying cgroup, so fail */
+	if (!cg_link->cgroup) {
+		ret = -ENOLINK;
+		goto out_unlock;
+	}
+	if (old_prog && link->prog != old_prog) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+	ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog);
+out_unlock:
+	mutex_unlock(&cgroup_mutex);
+	return ret;
+}
+
+static struct bpf_prog_list *find_detach_entry(struct list_head *progs,
+					       struct bpf_prog *prog,
+					       struct bpf_cgroup_link *link,
+					       bool allow_multi)
+{
+	struct bpf_prog_list *pl;
+
+	if (!allow_multi) {
+		if (list_empty(progs))
+			/* report error when trying to detach and nothing is attached */
+			return ERR_PTR(-ENOENT);
+
+		/* to maintain backward compatibility NONE and OVERRIDE cgroups
+		 * allow detaching with invalid FD (prog==NULL) in legacy mode
+		 */
+		return list_first_entry(progs, typeof(*pl), node);
+	}
+
+	if (!prog && !link)
+		/* to detach MULTI prog the user has to specify valid FD
+		 * of the program or link to be detached
+		 */
+		return ERR_PTR(-EINVAL);
+
+	/* find the prog or link and detach it */
+	list_for_each_entry(pl, progs, node) {
+		if (pl->prog == prog && pl->link == link)
+			return pl;
+	}
+	return ERR_PTR(-ENOENT);
+}
+
+/**
+ * __cgroup_bpf_detach() - Detach the program or link from a cgroup, and
+ *                         propagate the change to descendants
+ * @cgrp: The cgroup which descendants to traverse
+ * @prog: A program to detach or NULL
+ * @prog: A link to detach or NULL
+ * @type: Type of detach operation
+ *
+ * At most one of @prog or @link can be non-NULL.
+ * Must be called with cgroup_mutex held.
+ */
+int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+			struct bpf_cgroup_link *link, enum bpf_attach_type type)
+{
+	struct list_head *progs = &cgrp->bpf.progs[type];
+	u32 flags = cgrp->bpf.flags[type];
+	struct bpf_prog_list *pl;
+	struct bpf_prog *old_prog;
+	int err;
+
+	if (prog && link)
+		/* only one of prog or link can be specified */
+		return -EINVAL;
+
+	pl = find_detach_entry(progs, prog, link, flags & BPF_F_ALLOW_MULTI);
+	if (IS_ERR(pl))
+		return PTR_ERR(pl);
+
+	/* mark it deleted, so it's ignored while recomputing effective */
+	old_prog = pl->prog;
+	pl->prog = NULL;
+	pl->link = NULL;
 
 	err = update_effective_progs(cgrp, type);
 	if (err)
@@ -478,22 +692,19 @@
 
 	/* now can actually delete it from this cgroup list */
 	list_del(&pl->node);
-	for_each_cgroup_storage_type(stype) {
-		bpf_cgroup_storage_unlink(pl->storage[stype]);
-		bpf_cgroup_storage_free(pl->storage[stype]);
-	}
 	kfree(pl);
 	if (list_empty(progs))
 		/* last program was detached, reset flags to zero */
 		cgrp->bpf.flags[type] = 0;
-
-	bpf_prog_put(old_prog);
+	if (old_prog)
+		bpf_prog_put(old_prog);
 	static_branch_dec(&cgroup_bpf_enabled_key);
 	return 0;
 
 cleanup:
-	/* and restore back old_prog */
+	/* restore back prog or link */
 	pl->prog = old_prog;
+	pl->link = link;
 	return err;
 }
 
@@ -506,6 +717,7 @@
 	struct list_head *progs = &cgrp->bpf.progs[type];
 	u32 flags = cgrp->bpf.flags[type];
 	struct bpf_prog_array *effective;
+	struct bpf_prog *prog;
 	int cnt, ret = 0, i;
 
 	effective = rcu_dereference_protected(cgrp->bpf.effective[type],
@@ -536,7 +748,8 @@
 
 		i = 0;
 		list_for_each_entry(pl, progs, node) {
-			id = pl->prog->aux->id;
+			prog = prog_list_prog(pl);
+			id = prog->aux->id;
 			if (copy_to_user(prog_ids + i, &id, sizeof(id)))
 				return -EFAULT;
 			if (++i == cnt)
@@ -549,6 +762,7 @@
 int cgroup_bpf_prog_attach(const union bpf_attr *attr,
 			   enum bpf_prog_type ptype, struct bpf_prog *prog)
 {
+	struct bpf_prog *replace_prog = NULL;
 	struct cgroup *cgrp;
 	int ret;
 
@@ -556,8 +770,20 @@
 	if (IS_ERR(cgrp))
 		return PTR_ERR(cgrp);
 
-	ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type,
-				attr->attach_flags);
+	if ((attr->attach_flags & BPF_F_ALLOW_MULTI) &&
+	    (attr->attach_flags & BPF_F_REPLACE)) {
+		replace_prog = bpf_prog_get_type(attr->replace_bpf_fd, ptype);
+		if (IS_ERR(replace_prog)) {
+			cgroup_put(cgrp);
+			return PTR_ERR(replace_prog);
+		}
+	}
+
+	ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
+				attr->attach_type, attr->attach_flags);
+
+	if (replace_prog)
+		bpf_prog_put(replace_prog);
 	cgroup_put(cgrp);
 	return ret;
 }
@@ -576,7 +802,7 @@
 	if (IS_ERR(prog))
 		prog = NULL;
 
-	ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0);
+	ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type);
 	if (prog)
 		bpf_prog_put(prog);
 
@@ -584,6 +810,141 @@
 	return ret;
 }
 
+static void bpf_cgroup_link_release(struct bpf_link *link)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+	struct cgroup *cg;
+
+	/* link might have been auto-detached by dying cgroup already,
+	 * in that case our work is done here
+	 */
+	if (!cg_link->cgroup)
+		return;
+
+	mutex_lock(&cgroup_mutex);
+
+	/* re-check cgroup under lock again */
+	if (!cg_link->cgroup) {
+		mutex_unlock(&cgroup_mutex);
+		return;
+	}
+
+	WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
+				    cg_link->type));
+
+	cg = cg_link->cgroup;
+	cg_link->cgroup = NULL;
+
+	mutex_unlock(&cgroup_mutex);
+
+	cgroup_put(cg);
+}
+
+static void bpf_cgroup_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+
+	kfree(cg_link);
+}
+
+static int bpf_cgroup_link_detach(struct bpf_link *link)
+{
+	bpf_cgroup_link_release(link);
+
+	return 0;
+}
+
+static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link,
+					struct seq_file *seq)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+	u64 cg_id = 0;
+
+	mutex_lock(&cgroup_mutex);
+	if (cg_link->cgroup)
+		cg_id = cgroup_id(cg_link->cgroup);
+	mutex_unlock(&cgroup_mutex);
+
+	seq_printf(seq,
+		   "cgroup_id:\t%llu\n"
+		   "attach_type:\t%d\n",
+		   cg_id,
+		   cg_link->type);
+}
+
+static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
+					  struct bpf_link_info *info)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+	u64 cg_id = 0;
+
+	mutex_lock(&cgroup_mutex);
+	if (cg_link->cgroup)
+		cg_id = cgroup_id(cg_link->cgroup);
+	mutex_unlock(&cgroup_mutex);
+
+	info->cgroup.cgroup_id = cg_id;
+	info->cgroup.attach_type = cg_link->type;
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_cgroup_link_lops = {
+	.release = bpf_cgroup_link_release,
+	.dealloc = bpf_cgroup_link_dealloc,
+	.detach = bpf_cgroup_link_detach,
+	.update_prog = cgroup_bpf_replace,
+	.show_fdinfo = bpf_cgroup_link_show_fdinfo,
+	.fill_link_info = bpf_cgroup_link_fill_link_info,
+};
+
+int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	struct bpf_link_primer link_primer;
+	struct bpf_cgroup_link *link;
+	struct cgroup *cgrp;
+	int err;
+
+	if (attr->link_create.flags)
+		return -EINVAL;
+
+	cgrp = cgroup_get_from_fd(attr->link_create.target_fd);
+	if (IS_ERR(cgrp))
+		return PTR_ERR(cgrp);
+
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto out_put_cgroup;
+	}
+	bpf_link_init(&link->link, BPF_LINK_TYPE_CGROUP, &bpf_cgroup_link_lops,
+		      prog);
+	link->cgroup = cgrp;
+	link->type = attr->link_create.attach_type;
+
+	err  = bpf_link_prime(&link->link, &link_primer);
+	if (err) {
+		kfree(link);
+		goto out_put_cgroup;
+	}
+
+	err = cgroup_bpf_attach(cgrp, NULL, NULL, link, link->type,
+				BPF_F_ALLOW_MULTI);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		goto out_put_cgroup;
+	}
+
+	return bpf_link_settle(&link_primer);
+
+out_put_cgroup:
+	cgroup_put(cgrp);
+	return err;
+}
+
 int cgroup_bpf_prog_query(const union bpf_attr *attr,
 			  union bpf_attr __user *uattr)
 {
@@ -780,36 +1141,21 @@
 
 	return !allow;
 }
-EXPORT_SYMBOL(__cgroup_bpf_check_dev_permission);
 
 static const struct bpf_func_proto *
 cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
 	switch (func_id) {
-	case BPF_FUNC_map_lookup_elem:
-		return &bpf_map_lookup_elem_proto;
-	case BPF_FUNC_map_update_elem:
-		return &bpf_map_update_elem_proto;
-	case BPF_FUNC_map_delete_elem:
-		return &bpf_map_delete_elem_proto;
-	case BPF_FUNC_map_push_elem:
-		return &bpf_map_push_elem_proto;
-	case BPF_FUNC_map_pop_elem:
-		return &bpf_map_pop_elem_proto;
-	case BPF_FUNC_map_peek_elem:
-		return &bpf_map_peek_elem_proto;
 	case BPF_FUNC_get_current_uid_gid:
 		return &bpf_get_current_uid_gid_proto;
 	case BPF_FUNC_get_local_storage:
 		return &bpf_get_local_storage_proto;
 	case BPF_FUNC_get_current_cgroup_id:
 		return &bpf_get_current_cgroup_id_proto;
-	case BPF_FUNC_trace_printk:
-		if (capable(CAP_SYS_ADMIN))
-			return bpf_get_trace_printk_proto();
-		/* fall through */
+	case BPF_FUNC_perf_event_output:
+		return &bpf_event_output_data_proto;
 	default:
-		return NULL;
+		return bpf_base_func_proto(func_id);
 	}
 }
 
@@ -863,16 +1209,13 @@
  * @head: sysctl table header
  * @table: sysctl table
  * @write: sysctl is being read (= 0) or written (= 1)
- * @buf: pointer to buffer passed by user space
+ * @buf: pointer to buffer (in and out)
  * @pcount: value-result argument: value is size of buffer pointed to by @buf,
  *	result is size of @new_buf if program set new value, initial value
  *	otherwise
  * @ppos: value-result argument: value is position at which read from or write
  *	to sysctl is happening, result is new position if program overrode it,
  *	initial value otherwise
- * @new_buf: pointer to pointer to new buffer that will be allocated if program
- *	overrides new value provided by user space on sysctl write
- *	NOTE: it's caller responsibility to free *new_buf if it was set
  * @type: type of program to be executed
  *
  * Program is run when sysctl is being accessed, either read or written, and
@@ -883,8 +1226,7 @@
  */
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   struct ctl_table *table, int write,
-				   void __user *buf, size_t *pcount,
-				   loff_t *ppos, void **new_buf,
+				   char **buf, size_t *pcount, loff_t *ppos,
 				   enum bpf_attach_type type)
 {
 	struct bpf_sysctl_kern ctx = {
@@ -899,36 +1241,28 @@
 		.new_updated = 0,
 	};
 	struct cgroup *cgrp;
+	loff_t pos = 0;
 	int ret;
 
 	ctx.cur_val = kmalloc_track_caller(ctx.cur_len, GFP_KERNEL);
-	if (ctx.cur_val) {
-		mm_segment_t old_fs;
-		loff_t pos = 0;
-
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
-		if (table->proc_handler(table, 0, (void __user *)ctx.cur_val,
-					&ctx.cur_len, &pos)) {
-			/* Let BPF program decide how to proceed. */
-			ctx.cur_len = 0;
-		}
-		set_fs(old_fs);
-	} else {
+	if (!ctx.cur_val ||
+	    table->proc_handler(table, 0, ctx.cur_val, &ctx.cur_len, &pos)) {
 		/* Let BPF program decide how to proceed. */
 		ctx.cur_len = 0;
 	}
 
-	if (write && buf && *pcount) {
+	if (write && *buf && *pcount) {
 		/* BPF program should be able to override new value with a
 		 * buffer bigger than provided by user.
 		 */
 		ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
 		ctx.new_len = min_t(size_t, PAGE_SIZE, *pcount);
-		if (!ctx.new_val ||
-		    copy_from_user(ctx.new_val, buf, ctx.new_len))
+		if (ctx.new_val) {
+			memcpy(ctx.new_val, *buf, ctx.new_len);
+		} else {
 			/* Let BPF program decide how to proceed. */
 			ctx.new_len = 0;
+		}
 	}
 
 	rcu_read_lock();
@@ -939,7 +1273,8 @@
 	kfree(ctx.cur_val);
 
 	if (ret == 1 && ctx.new_updated) {
-		*new_buf = ctx.new_val;
+		kfree(*buf);
+		*buf = ctx.new_val;
 		*pcount = ctx.new_len;
 	} else {
 		kfree(ctx.new_val);
@@ -947,7 +1282,6 @@
 
 	return ret == 1 ? 0 : -EPERM;
 }
-EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl);
 
 #ifdef CONFIG_NET
 static bool __cgroup_bpf_prog_array_is_empty(struct cgroup *cgrp,
@@ -1066,7 +1400,6 @@
 	sockopt_free_buf(&ctx);
 	return ret;
 }
-EXPORT_SYMBOL(__cgroup_bpf_run_filter_setsockopt);
 
 int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
 				       int optname, char __user *optval,
@@ -1158,7 +1491,6 @@
 	sockopt_free_buf(&ctx);
 	return ret;
 }
-EXPORT_SYMBOL(__cgroup_bpf_run_filter_getsockopt);
 #endif
 
 static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
@@ -1370,7 +1702,7 @@
 		*insn++ = BPF_LDX_MEM(
 			BPF_SIZE(si->code), si->dst_reg, si->src_reg,
 			bpf_target_off(struct bpf_sysctl_kern, write,
-				       FIELD_SIZEOF(struct bpf_sysctl_kern,
+				       sizeof_field(struct bpf_sysctl_kern,
 						    write),
 				       target_size));
 		break;
@@ -1468,7 +1800,7 @@
 			return prog->expected_attach_type ==
 				BPF_CGROUP_GETSOCKOPT;
 		case offsetof(struct bpf_sockopt, optname):
-			/* fallthrough */
+			fallthrough;
 		case offsetof(struct bpf_sockopt, level):
 			if (size != size_default)
 				return false;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index d9a3d99..d3a1f25 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -25,11 +25,13 @@
 #include <linux/moduleloader.h>
 #include <linux/bpf.h>
 #include <linux/btf.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
 #include <linux/rbtree_latch.h>
 #include <linux/kallsyms.h>
 #include <linux/rcupdate.h>
 #include <linux/perf_event.h>
+#include <linux/extable.h>
+#include <linux/log2.h>
 
 #include <asm/barrier.h>
 #include <asm/unaligned.h>
@@ -82,7 +84,7 @@
 	struct bpf_prog *fp;
 
 	size = round_up(size, PAGE_SIZE);
-	fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
+	fp = __vmalloc(size, gfp_flags);
 	if (fp == NULL)
 		return NULL;
 
@@ -97,7 +99,9 @@
 	fp->aux->prog = fp;
 	fp->jit_requested = ebpf_jit_enabled();
 
-	INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
+	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
+	mutex_init(&fp->aux->used_maps_mutex);
+	mutex_init(&fp->aux->dst_mutex);
 
 	return fp;
 }
@@ -222,8 +226,6 @@
 	u32 pages, delta;
 	int ret;
 
-	BUG_ON(fp_old == NULL);
-
 	size = round_up(size, PAGE_SIZE);
 	pages = size / PAGE_SIZE;
 	if (pages <= fp_old->pages)
@@ -234,7 +236,7 @@
 	if (ret)
 		return NULL;
 
-	fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
+	fp = __vmalloc(size, gfp_flags);
 	if (fp == NULL) {
 		__bpf_prog_uncharge(fp_old->aux->user, delta);
 	} else {
@@ -255,7 +257,10 @@
 void __bpf_prog_free(struct bpf_prog *fp)
 {
 	if (fp->aux) {
+		mutex_destroy(&fp->aux->used_maps_mutex);
+		mutex_destroy(&fp->aux->dst_mutex);
 		free_percpu(fp->aux->stats);
+		kfree(fp->aux->poke_tab);
 		kfree(fp->aux);
 	}
 	vfree(fp);
@@ -263,10 +268,10 @@
 
 int bpf_prog_calc_tag(struct bpf_prog *fp)
 {
-	const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
+	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
 	u32 raw_size = bpf_prog_tag_scratch_size(fp);
-	u32 digest[SHA_DIGEST_WORDS];
-	u32 ws[SHA_WORKSPACE_WORDS];
+	u32 digest[SHA1_DIGEST_WORDS];
+	u32 ws[SHA1_WORKSPACE_WORDS];
 	u32 i, bsize, psize, blocks;
 	struct bpf_insn *dst;
 	bool was_ld_map;
@@ -278,7 +283,7 @@
 	if (!raw)
 		return -ENOMEM;
 
-	sha_init(digest);
+	sha1_init(digest);
 	memset(ws, 0, sizeof(ws));
 
 	/* We need to take out the map fd for the digest calculation
@@ -309,8 +314,8 @@
 	memset(&raw[psize], 0, raw_size - psize);
 	raw[psize++] = 0x80;
 
-	bsize  = round_up(psize, SHA_MESSAGE_BYTES);
-	blocks = bsize / SHA_MESSAGE_BYTES;
+	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
+	blocks = bsize / SHA1_BLOCK_SIZE;
 	todo   = raw;
 	if (bsize - psize >= sizeof(__be64)) {
 		bits = (__be64 *)(todo + bsize - sizeof(__be64));
@@ -321,12 +326,12 @@
 	*bits = cpu_to_be64((psize - 1) << 3);
 
 	while (blocks--) {
-		sha_transform(digest, todo, ws);
-		todo += SHA_MESSAGE_BYTES;
+		sha1_transform(digest, todo, ws);
+		todo += SHA1_BLOCK_SIZE;
 	}
 
 	result = (__force __be32 *)digest;
-	for (i = 0; i < SHA_DIGEST_WORDS; i++)
+	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
 		result[i] = cpu_to_be32(digest[i]);
 	memcpy(fp->tag, result, sizeof(fp->tag));
 
@@ -519,27 +524,28 @@
 
 #ifdef CONFIG_BPF_JIT
 /* All BPF JIT sysctl knobs here. */
-int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);
+int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
+int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 int bpf_jit_harden   __read_mostly;
-int bpf_jit_kallsyms __read_mostly;
 long bpf_jit_limit   __read_mostly;
+long bpf_jit_limit_max __read_mostly;
 
-static __always_inline void
-bpf_get_prog_addr_region(const struct bpf_prog *prog,
-			 unsigned long *symbol_start,
-			 unsigned long *symbol_end)
+static void
+bpf_prog_ksym_set_addr(struct bpf_prog *prog)
 {
 	const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
 	unsigned long addr = (unsigned long)hdr;
 
 	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
 
-	*symbol_start = addr;
-	*symbol_end   = addr + hdr->pages * PAGE_SIZE;
+	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
+	prog->aux->ksym.end   = addr + hdr->pages * PAGE_SIZE;
 }
 
-void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
+static void
+bpf_prog_ksym_set_name(struct bpf_prog *prog)
 {
+	char *sym = prog->aux->ksym.name;
 	const char *end = sym + KSYM_NAME_LEN;
 	const struct btf_type *type;
 	const char *func_name;
@@ -573,36 +579,27 @@
 		*sym = 0;
 }
 
-static __always_inline unsigned long
-bpf_get_prog_addr_start(struct latch_tree_node *n)
+static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
 {
-	unsigned long symbol_start, symbol_end;
-	const struct bpf_prog_aux *aux;
-
-	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
-	bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
-
-	return symbol_start;
+	return container_of(n, struct bpf_ksym, tnode)->start;
 }
 
 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
 					  struct latch_tree_node *b)
 {
-	return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);
+	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
 }
 
 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
 {
 	unsigned long val = (unsigned long)key;
-	unsigned long symbol_start, symbol_end;
-	const struct bpf_prog_aux *aux;
+	const struct bpf_ksym *ksym;
 
-	aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
-	bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
+	ksym = container_of(n, struct bpf_ksym, tnode);
 
-	if (val < symbol_start)
+	if (val < ksym->start)
 		return -1;
-	if (val >= symbol_end)
+	if (val >= ksym->end)
 		return  1;
 
 	return 0;
@@ -617,20 +614,29 @@
 static LIST_HEAD(bpf_kallsyms);
 static struct latch_tree_root bpf_tree __cacheline_aligned;
 
-static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
+void bpf_ksym_add(struct bpf_ksym *ksym)
 {
-	WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
-	list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
-	latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
+	spin_lock_bh(&bpf_lock);
+	WARN_ON_ONCE(!list_empty(&ksym->lnode));
+	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
+	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
+	spin_unlock_bh(&bpf_lock);
 }
 
-static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
+static void __bpf_ksym_del(struct bpf_ksym *ksym)
 {
-	if (list_empty(&aux->ksym_lnode))
+	if (list_empty(&ksym->lnode))
 		return;
 
-	latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
-	list_del_rcu(&aux->ksym_lnode);
+	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
+	list_del_rcu(&ksym->lnode);
+}
+
+void bpf_ksym_del(struct bpf_ksym *ksym)
+{
+	spin_lock_bh(&bpf_lock);
+	__bpf_ksym_del(ksym);
+	spin_unlock_bh(&bpf_lock);
 }
 
 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
@@ -640,19 +646,21 @@
 
 static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
 {
-	return list_empty(&fp->aux->ksym_lnode) ||
-	       fp->aux->ksym_lnode.prev == LIST_POISON2;
+	return list_empty(&fp->aux->ksym.lnode) ||
+	       fp->aux->ksym.lnode.prev == LIST_POISON2;
 }
 
 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 {
 	if (!bpf_prog_kallsyms_candidate(fp) ||
-	    !capable(CAP_SYS_ADMIN))
+	    !bpf_capable())
 		return;
 
-	spin_lock_bh(&bpf_lock);
-	bpf_prog_ksym_node_add(fp->aux);
-	spin_unlock_bh(&bpf_lock);
+	bpf_prog_ksym_set_addr(fp);
+	bpf_prog_ksym_set_name(fp);
+	fp->aux->ksym.prog = true;
+
+	bpf_ksym_add(&fp->aux->ksym);
 }
 
 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
@@ -660,36 +668,30 @@
 	if (!bpf_prog_kallsyms_candidate(fp))
 		return;
 
-	spin_lock_bh(&bpf_lock);
-	bpf_prog_ksym_node_del(fp->aux);
-	spin_unlock_bh(&bpf_lock);
+	bpf_ksym_del(&fp->aux->ksym);
 }
 
-static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
+static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
 {
 	struct latch_tree_node *n;
 
-	if (!bpf_jit_kallsyms_enabled())
-		return NULL;
-
 	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
-	return n ?
-	       container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
-	       NULL;
+	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
 }
 
 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 				 unsigned long *off, char *sym)
 {
-	unsigned long symbol_start, symbol_end;
-	struct bpf_prog *prog;
+	struct bpf_ksym *ksym;
 	char *ret = NULL;
 
 	rcu_read_lock();
-	prog = bpf_prog_kallsyms_find(addr);
-	if (prog) {
-		bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end);
-		bpf_get_prog_name(prog, sym);
+	ksym = bpf_ksym_find(addr);
+	if (ksym) {
+		unsigned long symbol_start = ksym->start;
+		unsigned long symbol_end = ksym->end;
+
+		strncpy(sym, ksym->name, KSYM_NAME_LEN);
 
 		ret = sym;
 		if (size)
@@ -707,16 +709,43 @@
 	bool ret;
 
 	rcu_read_lock();
-	ret = bpf_prog_kallsyms_find(addr) != NULL;
+	ret = bpf_ksym_find(addr) != NULL;
 	rcu_read_unlock();
 
 	return ret;
 }
 
+static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
+{
+	struct bpf_ksym *ksym = bpf_ksym_find(addr);
+
+	return ksym && ksym->prog ?
+	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
+	       NULL;
+}
+
+const struct exception_table_entry *search_bpf_extables(unsigned long addr)
+{
+	const struct exception_table_entry *e = NULL;
+	struct bpf_prog *prog;
+
+	rcu_read_lock();
+	prog = bpf_prog_ksym_find(addr);
+	if (!prog)
+		goto out;
+	if (!prog->aux->num_exentries)
+		goto out;
+
+	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
+out:
+	rcu_read_unlock();
+	return e;
+}
+
 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 		    char *sym)
 {
-	struct bpf_prog_aux *aux;
+	struct bpf_ksym *ksym;
 	unsigned int it = 0;
 	int ret = -ERANGE;
 
@@ -724,13 +753,13 @@
 		return ret;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
+	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
 		if (it++ != symnum)
 			continue;
 
-		bpf_get_prog_name(aux->prog, sym);
+		strncpy(sym, ksym->name, KSYM_NAME_LEN);
 
-		*value = (unsigned long)aux->prog->bpf_func;
+		*value = ksym->start;
 		*type  = BPF_SYM_ELF_TYPE;
 
 		ret = 0;
@@ -741,6 +770,40 @@
 	return ret;
 }
 
+int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
+				struct bpf_jit_poke_descriptor *poke)
+{
+	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
+	static const u32 poke_tab_max = 1024;
+	u32 slot = prog->aux->size_poke_tab;
+	u32 size = slot + 1;
+
+	if (size > poke_tab_max)
+		return -ENOSPC;
+	if (poke->tailcall_target || poke->tailcall_target_stable ||
+	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
+		return -EINVAL;
+
+	switch (poke->reason) {
+	case BPF_POKE_REASON_TAIL_CALL:
+		if (!poke->tail_call.map)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
+	if (!tab)
+		return -ENOMEM;
+
+	memcpy(&tab[slot], poke, sizeof(*poke));
+	prog->aux->size_poke_tab = size;
+	prog->aux->poke_tab = tab;
+
+	return slot;
+}
+
 static atomic_long_t bpf_jit_current;
 
 /* Can be overridden by an arch's JIT compiler if it has a custom,
@@ -759,17 +822,18 @@
 static int __init bpf_jit_charge_init(void)
 {
 	/* Only used as heuristic here to derive limit. */
-	bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
+	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
+	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2,
 					    PAGE_SIZE), LONG_MAX);
 	return 0;
 }
 pure_initcall(bpf_jit_charge_init);
 
-static int bpf_jit_charge_modmem(u32 pages)
+int bpf_jit_charge_modmem(u32 pages)
 {
 	if (atomic_long_add_return(pages, &bpf_jit_current) >
 	    (bpf_jit_limit >> PAGE_SHIFT)) {
-		if (!capable(CAP_SYS_ADMIN)) {
+		if (!bpf_capable()) {
 			atomic_long_sub(pages, &bpf_jit_current);
 			return -EPERM;
 		}
@@ -778,7 +842,7 @@
 	return 0;
 }
 
-static void bpf_jit_uncharge_modmem(u32 pages)
+void bpf_jit_uncharge_modmem(u32 pages)
 {
 	atomic_long_sub(pages, &bpf_jit_current);
 }
@@ -801,6 +865,9 @@
 	struct bpf_binary_header *hdr;
 	u32 size, hole, start, pages;
 
+	WARN_ON_ONCE(!is_power_of_2(alignment) ||
+		     alignment > BPF_IMAGE_ALIGNMENT);
+
 	/* Most of BPF filters are really small, but if some of them
 	 * fill a page, allow at least 128 extra bytes to insert a
 	 * random section of illegal instructions.
@@ -1031,7 +1098,7 @@
 	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
 	struct bpf_prog *fp;
 
-	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
+	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
 	if (fp != NULL) {
 		/* aux->prog still points to the fp_other one, so
 		 * when promoting the clone to the real program,
@@ -1292,6 +1359,12 @@
 }
 
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
+u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
+{
+	memset(dst, 0, size);
+	return -EFAULT;
+}
+
 /**
  *	__bpf_prog_run - run eBPF program on a given context
  *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
@@ -1312,6 +1385,10 @@
 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
 		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
 	};
 #undef BPF_INSN_3_LBL
 #undef BPF_INSN_2_LBL
@@ -1501,7 +1578,7 @@
 
 		/* ARG1 at this point is guaranteed to point to CTX from
 		 * the verifier side due to the fact that the tail call is
-		 * handeled like a helper, that is, bpf_tail_call_proto,
+		 * handled like a helper, that is, bpf_tail_call_proto,
 		 * where arg1_type is ARG_PTR_TO_CTX.
 		 */
 		insn = prog->insnsi;
@@ -1583,6 +1660,16 @@
 	LDST(W,  u32)
 	LDST(DW, u64)
 #undef LDST
+#define LDX_PROBE(SIZEOP, SIZE)							\
+	LDX_PROBE_MEM_##SIZEOP:							\
+		bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off));	\
+		CONT;
+	LDX_PROBE(B,  1)
+	LDX_PROBE(H,  2)
+	LDX_PROBE(W,  4)
+	LDX_PROBE(DW, 8)
+#undef LDX_PROBE
+
 	STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
 		atomic_add((u32) SRC, (atomic_t *)(unsigned long)
 			   (DST + insn->off));
@@ -1690,28 +1777,34 @@
 bool bpf_prog_array_compatible(struct bpf_array *array,
 			       const struct bpf_prog *fp)
 {
+	bool ret;
+
 	if (fp->kprobe_override)
 		return false;
 
-	if (!array->owner_prog_type) {
+	spin_lock(&array->aux->owner.lock);
+
+	if (!array->aux->owner.type) {
 		/* There's no owner yet where we could check for
 		 * compatibility.
 		 */
-		array->owner_prog_type = fp->type;
-		array->owner_jited = fp->jited;
-
-		return true;
+		array->aux->owner.type  = fp->type;
+		array->aux->owner.jited = fp->jited;
+		ret = true;
+	} else {
+		ret = array->aux->owner.type  == fp->type &&
+		      array->aux->owner.jited == fp->jited;
 	}
-
-	return array->owner_prog_type == fp->type &&
-	       array->owner_jited == fp->jited;
+	spin_unlock(&array->aux->owner.lock);
+	return ret;
 }
 
 static int bpf_check_tail_call(const struct bpf_prog *fp)
 {
 	struct bpf_prog_aux *aux = fp->aux;
-	int i;
+	int i, ret = 0;
 
+	mutex_lock(&aux->used_maps_mutex);
 	for (i = 0; i < aux->used_map_cnt; i++) {
 		struct bpf_map *map = aux->used_maps[i];
 		struct bpf_array *array;
@@ -1720,11 +1813,15 @@
 			continue;
 
 		array = container_of(map, struct bpf_array, map);
-		if (!bpf_prog_array_compatible(array, fp))
-			return -EINVAL;
+		if (!bpf_prog_array_compatible(array, fp)) {
+			ret = -EINVAL;
+			goto out;
+		}
 	}
 
-	return 0;
+out:
+	mutex_unlock(&aux->used_maps_mutex);
+	return ret;
 }
 
 static void bpf_prog_select_func(struct bpf_prog *fp)
@@ -1921,6 +2018,61 @@
 		}
 }
 
+/**
+ * bpf_prog_array_delete_safe_at() - Replaces the program at the given
+ *                                   index into the program array with
+ *                                   a dummy no-op program.
+ * @array: a bpf_prog_array
+ * @index: the index of the program to replace
+ *
+ * Skips over dummy programs, by not counting them, when calculating
+ * the position of the program to replace.
+ *
+ * Return:
+ * * 0		- Success
+ * * -EINVAL	- Invalid index value. Must be a non-negative integer.
+ * * -ENOENT	- Index out of range
+ */
+int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
+{
+	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
+}
+
+/**
+ * bpf_prog_array_update_at() - Updates the program at the given index
+ *                              into the program array.
+ * @array: a bpf_prog_array
+ * @index: the index of the program to update
+ * @prog: the program to insert into the array
+ *
+ * Skips over dummy programs, by not counting them, when calculating
+ * the position of the program to update.
+ *
+ * Return:
+ * * 0		- Success
+ * * -EINVAL	- Invalid index value. Must be a non-negative integer.
+ * * -ENOENT	- Index out of range
+ */
+int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
+			     struct bpf_prog *prog)
+{
+	struct bpf_prog_array_item *item;
+
+	if (unlikely(index < 0))
+		return -EINVAL;
+
+	for (item = array->items; item->prog; item++) {
+		if (item->prog == &dummy_bpf_prog.prog)
+			continue;
+		if (!index) {
+			WRITE_ONCE(item->prog, prog);
+			return 0;
+		}
+		index--;
+	}
+	return -ENOENT;
+}
+
 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
 			struct bpf_prog *exclude_prog,
 			struct bpf_prog *include_prog,
@@ -2005,20 +2157,49 @@
 								     : 0;
 }
 
+void __bpf_free_used_maps(struct bpf_prog_aux *aux,
+			  struct bpf_map **used_maps, u32 len)
+{
+	struct bpf_map *map;
+	u32 i;
+
+	for (i = 0; i < len; i++) {
+		map = used_maps[i];
+		if (map->ops->map_poke_untrack)
+			map->ops->map_poke_untrack(map, aux);
+		bpf_map_put(map);
+	}
+}
+
+static void bpf_free_used_maps(struct bpf_prog_aux *aux)
+{
+	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
+	kfree(aux->used_maps);
+}
+
 static void bpf_prog_free_deferred(struct work_struct *work)
 {
 	struct bpf_prog_aux *aux;
 	int i;
 
 	aux = container_of(work, struct bpf_prog_aux, work);
+	bpf_free_used_maps(aux);
 	if (bpf_prog_is_dev_bound(aux))
 		bpf_prog_offload_destroy(aux->prog);
 #ifdef CONFIG_PERF_EVENTS
 	if (aux->prog->has_callchain_buf)
 		put_callchain_buffers();
 #endif
-	for (i = 0; i < aux->func_cnt; i++)
+	if (aux->dst_trampoline)
+		bpf_trampoline_put(aux->dst_trampoline);
+	for (i = 0; i < aux->func_cnt; i++) {
+		/* We can just unlink the subprog poke descriptor table as
+		 * it was originally linked to the main program and is also
+		 * released along with it.
+		 */
+		aux->func[i]->aux->poke_tab = NULL;
 		bpf_jit_free(aux->func[i]);
+	}
 	if (aux->func_cnt) {
 		kfree(aux->func);
 		bpf_prog_unlock_free(aux->prog);
@@ -2032,6 +2213,8 @@
 {
 	struct bpf_prog_aux *aux = fp->aux;
 
+	if (aux->dst_prog)
+		bpf_prog_put(aux->dst_prog);
 	INIT_WORK(&aux->work, bpf_prog_free_deferred);
 	schedule_work(&aux->work);
 }
@@ -2063,6 +2246,11 @@
 	return res;
 }
 
+BPF_CALL_0(bpf_get_raw_cpu_id)
+{
+	return raw_smp_processor_id();
+}
+
 /* Weak definitions of helper functions in case we don't have bpf syscall. */
 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
@@ -2072,17 +2260,23 @@
 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
 const struct bpf_func_proto bpf_spin_lock_proto __weak;
 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
+const struct bpf_func_proto bpf_jiffies64_proto __weak;
 
 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
+const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
 
 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
+const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
+const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
+const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
 
 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
 {
@@ -2146,6 +2340,12 @@
 	return -EFAULT;
 }
 
+int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
+			      void *addr1, void *addr2)
+{
+	return -ENOTSUPP;
+}
+
 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 EXPORT_SYMBOL(bpf_stats_enabled_key);
 
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index a367fc8..c61a23b 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -52,7 +52,6 @@
 struct bpf_cpu_map_entry {
 	u32 cpu;    /* kthread CPU and map index */
 	int map_id; /* Back reference to map */
-	u32 qsize;  /* Queue size placeholder for map lookup */
 
 	/* XDP can run multiple RX-ring queues, need __percpu enqueue store */
 	struct xdp_bulk_queue __percpu *bulkq;
@@ -62,34 +61,40 @@
 	/* Queue with potential multi-producers, and single-consumer kthread */
 	struct ptr_ring *queue;
 	struct task_struct *kthread;
-	struct work_struct kthread_stop_wq;
+
+	struct bpf_cpumap_val value;
+	struct bpf_prog *prog;
 
 	atomic_t refcnt; /* Control when this struct can be free'ed */
 	struct rcu_head rcu;
+
+	struct work_struct kthread_stop_wq;
 };
 
 struct bpf_cpu_map {
 	struct bpf_map map;
 	/* Below members specific for map type */
 	struct bpf_cpu_map_entry **cpu_map;
-	struct list_head __percpu *flush_list;
 };
 
-static int bq_flush_to_queue(struct xdp_bulk_queue *bq, bool in_napi_ctx);
+static DEFINE_PER_CPU(struct list_head, cpu_map_flush_list);
 
 static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
 {
+	u32 value_size = attr->value_size;
 	struct bpf_cpu_map *cmap;
 	int err = -ENOMEM;
-	int ret, cpu;
 	u64 cost;
+	int ret;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!bpf_capable())
 		return ERR_PTR(-EPERM);
 
 	/* check sanity of attributes */
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
-	    attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE)
+	    (value_size != offsetofend(struct bpf_cpumap_val, qsize) &&
+	     value_size != offsetofend(struct bpf_cpumap_val, bpf_prog.fd)) ||
+	    attr->map_flags & ~BPF_F_NUMA_NODE)
 		return ERR_PTR(-EINVAL);
 
 	cmap = kzalloc(sizeof(*cmap), GFP_USER);
@@ -106,7 +111,6 @@
 
 	/* make sure page count doesn't overflow */
 	cost = (u64) cmap->map.max_entries * sizeof(struct bpf_cpu_map_entry *);
-	cost += sizeof(struct list_head) * num_possible_cpus();
 
 	/* Notice returns -EPERM on if map size is larger than memlock limit */
 	ret = bpf_map_charge_init(&cmap->map.memory, cost);
@@ -115,23 +119,14 @@
 		goto free_cmap;
 	}
 
-	cmap->flush_list = alloc_percpu(struct list_head);
-	if (!cmap->flush_list)
-		goto free_charge;
-
-	for_each_possible_cpu(cpu)
-		INIT_LIST_HEAD(per_cpu_ptr(cmap->flush_list, cpu));
-
 	/* Alloc array for possible remote "destination" CPUs */
 	cmap->cpu_map = bpf_map_area_alloc(cmap->map.max_entries *
 					   sizeof(struct bpf_cpu_map_entry *),
 					   cmap->map.numa_node);
 	if (!cmap->cpu_map)
-		goto free_percpu;
+		goto free_charge;
 
 	return &cmap->map;
-free_percpu:
-	free_percpu(cmap->flush_list);
 free_charge:
 	bpf_map_charge_finish(&cmap->map.memory);
 free_cmap:
@@ -160,8 +155,7 @@
 	kthread_stop(rcpu->kthread);
 }
 
-static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
-					 struct xdp_frame *xdpf,
+static struct sk_buff *cpu_map_build_skb(struct xdp_frame *xdpf,
 					 struct sk_buff *skb)
 {
 	unsigned int hard_start_headroom;
@@ -171,25 +165,10 @@
 	/* Part of headroom was reserved to xdpf */
 	hard_start_headroom = sizeof(struct xdp_frame) +  xdpf->headroom;
 
-	/* build_skb need to place skb_shared_info after SKB end, and
-	 * also want to know the memory "truesize".  Thus, need to
-	 * know the memory frame size backing xdp_buff.
-	 *
-	 * XDP was designed to have PAGE_SIZE frames, but this
-	 * assumption is not longer true with ixgbe and i40e.  It
-	 * would be preferred to set frame_size to 2048 or 4096
-	 * depending on the driver.
-	 *   frame_size = 2048;
-	 *   frame_len  = frame_size - sizeof(*xdp_frame);
-	 *
-	 * Instead, with info avail, skb_shared_info in placed after
-	 * packet len.  This, unfortunately fakes the truesize.
-	 * Another disadvantage of this approach, the skb_shared_info
-	 * is not at a fixed memory location, with mixed length
-	 * packets, which is bad for cache-line hotness.
+	/* Memory size backing xdp_frame data already have reserved
+	 * room for build_skb to place skb_shared_info in tailroom.
 	 */
-	frame_size = SKB_DATA_ALIGN(xdpf->len + hard_start_headroom) +
-		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+	frame_size = xdpf->frame_sz;
 
 	pkt_data_start = xdpf->data - hard_start_headroom;
 	skb = build_skb_around(skb, pkt_data_start, frame_size);
@@ -236,6 +215,8 @@
 static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
 {
 	if (atomic_dec_and_test(&rcpu->refcnt)) {
+		if (rcpu->prog)
+			bpf_prog_put(rcpu->prog);
 		/* The queue should be empty at this point */
 		__cpu_map_ring_cleanup(rcpu->queue);
 		ptr_ring_cleanup(rcpu->queue, NULL);
@@ -244,6 +225,75 @@
 	}
 }
 
+static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
+				    void **frames, int n,
+				    struct xdp_cpumap_stats *stats)
+{
+	struct xdp_rxq_info rxq;
+	struct xdp_buff xdp;
+	int i, nframes = 0;
+
+	if (!rcpu->prog)
+		return n;
+
+	rcu_read_lock_bh();
+
+	xdp_set_return_frame_no_direct();
+	xdp.rxq = &rxq;
+
+	for (i = 0; i < n; i++) {
+		struct xdp_frame *xdpf = frames[i];
+		u32 act;
+		int err;
+
+		rxq.dev = xdpf->dev_rx;
+		rxq.mem = xdpf->mem;
+		/* TODO: report queue_index to xdp_rxq_info */
+
+		xdp_convert_frame_to_buff(xdpf, &xdp);
+
+		act = bpf_prog_run_xdp(rcpu->prog, &xdp);
+		switch (act) {
+		case XDP_PASS:
+			err = xdp_update_frame_from_buff(&xdp, xdpf);
+			if (err < 0) {
+				xdp_return_frame(xdpf);
+				stats->drop++;
+			} else {
+				frames[nframes++] = xdpf;
+				stats->pass++;
+			}
+			break;
+		case XDP_REDIRECT:
+			err = xdp_do_redirect(xdpf->dev_rx, &xdp,
+					      rcpu->prog);
+			if (unlikely(err)) {
+				xdp_return_frame(xdpf);
+				stats->drop++;
+			} else {
+				stats->redirect++;
+			}
+			break;
+		default:
+			bpf_warn_invalid_xdp_action(act);
+			fallthrough;
+		case XDP_DROP:
+			xdp_return_frame(xdpf);
+			stats->drop++;
+			break;
+		}
+	}
+
+	if (stats->redirect)
+		xdp_do_flush_map();
+
+	xdp_clear_return_frame_no_direct();
+
+	rcu_read_unlock_bh(); /* resched point, may call do_softirq() */
+
+	return nframes;
+}
+
 #define CPUMAP_BATCH 8
 
 static int cpu_map_kthread_run(void *data)
@@ -258,11 +308,12 @@
 	 * kthread_stop signal until queue is empty.
 	 */
 	while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) {
+		struct xdp_cpumap_stats stats = {}; /* zero stats */
+		gfp_t gfp = __GFP_ZERO | GFP_ATOMIC;
 		unsigned int drops = 0, sched = 0;
 		void *frames[CPUMAP_BATCH];
 		void *skbs[CPUMAP_BATCH];
-		gfp_t gfp = __GFP_ZERO | GFP_ATOMIC;
-		int i, n, m;
+		int i, n, m, nframes;
 
 		/* Release CPU reschedule checks */
 		if (__ptr_ring_empty(rcpu->queue)) {
@@ -283,8 +334,8 @@
 		 * kthread CPU pinned. Lockless access to ptr_ring
 		 * consume side valid as no-resize allowed of queue.
 		 */
-		n = ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH);
-
+		n = __ptr_ring_consume_batched(rcpu->queue, frames,
+					       CPUMAP_BATCH);
 		for (i = 0; i < n; i++) {
 			void *f = frames[i];
 			struct page *page = virt_to_page(f);
@@ -296,20 +347,24 @@
 			prefetchw(page);
 		}
 
-		m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, n, skbs);
-		if (unlikely(m == 0)) {
-			for (i = 0; i < n; i++)
-				skbs[i] = NULL; /* effect: xdp_return_frame */
-			drops = n;
+		/* Support running another XDP prog on this CPU */
+		nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, n, &stats);
+		if (nframes) {
+			m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, nframes, skbs);
+			if (unlikely(m == 0)) {
+				for (i = 0; i < nframes; i++)
+					skbs[i] = NULL; /* effect: xdp_return_frame */
+				drops += nframes;
+			}
 		}
 
 		local_bh_disable();
-		for (i = 0; i < n; i++) {
+		for (i = 0; i < nframes; i++) {
 			struct xdp_frame *xdpf = frames[i];
 			struct sk_buff *skb = skbs[i];
 			int ret;
 
-			skb = cpu_map_build_skb(rcpu, xdpf, skb);
+			skb = cpu_map_build_skb(xdpf, skb);
 			if (!skb) {
 				xdp_return_frame(xdpf);
 				continue;
@@ -321,7 +376,7 @@
 				drops++;
 		}
 		/* Feedback loop via tracepoint */
-		trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched);
+		trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched, &stats);
 
 		local_bh_enable(); /* resched point, may call do_softirq() */
 	}
@@ -331,13 +386,38 @@
 	return 0;
 }
 
-static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu,
-						       int map_id)
+bool cpu_map_prog_allowed(struct bpf_map *map)
 {
+	return map->map_type == BPF_MAP_TYPE_CPUMAP &&
+	       map->value_size != offsetofend(struct bpf_cpumap_val, qsize);
+}
+
+static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu, int fd)
+{
+	struct bpf_prog *prog;
+
+	prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	if (prog->expected_attach_type != BPF_XDP_CPUMAP) {
+		bpf_prog_put(prog);
+		return -EINVAL;
+	}
+
+	rcpu->value.bpf_prog.id = prog->aux->id;
+	rcpu->prog = prog;
+
+	return 0;
+}
+
+static struct bpf_cpu_map_entry *
+__cpu_map_entry_alloc(struct bpf_cpumap_val *value, u32 cpu, int map_id)
+{
+	int numa, err, i, fd = value->bpf_prog.fd;
 	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
 	struct bpf_cpu_map_entry *rcpu;
 	struct xdp_bulk_queue *bq;
-	int numa, err, i;
 
 	/* Have map->numa_node, but choose node of redirect target CPU */
 	numa = cpu_to_node(cpu);
@@ -362,19 +442,22 @@
 	if (!rcpu->queue)
 		goto free_bulkq;
 
-	err = ptr_ring_init(rcpu->queue, qsize, gfp);
+	err = ptr_ring_init(rcpu->queue, value->qsize, gfp);
 	if (err)
 		goto free_queue;
 
 	rcpu->cpu    = cpu;
 	rcpu->map_id = map_id;
-	rcpu->qsize  = qsize;
+	rcpu->value.qsize  = value->qsize;
+
+	if (fd > 0 && __cpu_map_load_bpf_program(rcpu, fd))
+		goto free_ptr_ring;
 
 	/* Setup kthread */
 	rcpu->kthread = kthread_create_on_node(cpu_map_kthread_run, rcpu, numa,
 					       "cpumap/%d/map:%d", cpu, map_id);
 	if (IS_ERR(rcpu->kthread))
-		goto free_ptr_ring;
+		goto free_prog;
 
 	get_cpu_map_entry(rcpu); /* 1-refcnt for being in cmap->cpu_map[] */
 	get_cpu_map_entry(rcpu); /* 1-refcnt for kthread */
@@ -385,6 +468,9 @@
 
 	return rcpu;
 
+free_prog:
+	if (rcpu->prog)
+		bpf_prog_put(rcpu->prog);
 free_ptr_ring:
 	ptr_ring_cleanup(rcpu->queue, NULL);
 free_queue:
@@ -399,22 +485,14 @@
 static void __cpu_map_entry_free(struct rcu_head *rcu)
 {
 	struct bpf_cpu_map_entry *rcpu;
-	int cpu;
 
 	/* This cpu_map_entry have been disconnected from map and one
-	 * RCU graze-period have elapsed.  Thus, XDP cannot queue any
+	 * RCU grace-period have elapsed.  Thus, XDP cannot queue any
 	 * new packets and cannot change/set flush_needed that can
 	 * find this entry.
 	 */
 	rcpu = container_of(rcu, struct bpf_cpu_map_entry, rcu);
 
-	/* Flush remaining packets in percpu bulkq */
-	for_each_online_cpu(cpu) {
-		struct xdp_bulk_queue *bq = per_cpu_ptr(rcpu->bulkq, cpu);
-
-		/* No concurrent bq_enqueue can run at this point */
-		bq_flush_to_queue(bq, false);
-	}
 	free_percpu(rcpu->bulkq);
 	/* Cannot kthread_stop() here, last put free rcpu resources */
 	put_cpu_map_entry(rcpu);
@@ -436,7 +514,7 @@
  * percpu bulkq to queue.  Due to caller map_delete_elem() disable
  * preemption, cannot call kthread_stop() to make sure queue is empty.
  * Instead a work_queue is started for stopping kthread,
- * cpu_map_kthread_stop, which waits for an RCU graze period before
+ * cpu_map_kthread_stop, which waits for an RCU grace period before
  * stopping kthread, emptying the queue.
  */
 static void __cpu_map_entry_replace(struct bpf_cpu_map *cmap,
@@ -469,12 +547,12 @@
 			       u64 map_flags)
 {
 	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
+	struct bpf_cpumap_val cpumap_value = {};
 	struct bpf_cpu_map_entry *rcpu;
-
 	/* Array index key correspond to CPU number */
 	u32 key_cpu = *(u32 *)key;
-	/* Value is the queue size */
-	u32 qsize = *(u32 *)value;
+
+	memcpy(&cpumap_value, value, map->value_size);
 
 	if (unlikely(map_flags > BPF_EXIST))
 		return -EINVAL;
@@ -482,18 +560,18 @@
 		return -E2BIG;
 	if (unlikely(map_flags == BPF_NOEXIST))
 		return -EEXIST;
-	if (unlikely(qsize > 16384)) /* sanity limit on qsize */
+	if (unlikely(cpumap_value.qsize > 16384)) /* sanity limit on qsize */
 		return -EOVERFLOW;
 
 	/* Make sure CPU is a valid possible cpu */
 	if (key_cpu >= nr_cpumask_bits || !cpu_possible(key_cpu))
 		return -ENODEV;
 
-	if (qsize == 0) {
+	if (cpumap_value.qsize == 0) {
 		rcpu = NULL; /* Same as deleting */
 	} else {
 		/* Updating qsize cause re-allocation of bpf_cpu_map_entry */
-		rcpu = __cpu_map_entry_alloc(qsize, key_cpu, map->id);
+		rcpu = __cpu_map_entry_alloc(&cpumap_value, key_cpu, map->id);
 		if (!rcpu)
 			return -ENOMEM;
 		rcpu->cmap = cmap;
@@ -507,7 +585,6 @@
 static void cpu_map_free(struct bpf_map *map)
 {
 	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
-	int cpu;
 	u32 i;
 
 	/* At this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
@@ -522,18 +599,6 @@
 	bpf_clear_redirect_map(map);
 	synchronize_rcu();
 
-	/* To ensure all pending flush operations have completed wait for flush
-	 * list be empty on _all_ cpus. Because the above synchronize_rcu()
-	 * ensures the map is disconnected from the program we can assume no new
-	 * items will be added to the list.
-	 */
-	for_each_online_cpu(cpu) {
-		struct list_head *flush_list = per_cpu_ptr(cmap->flush_list, cpu);
-
-		while (!list_empty(flush_list))
-			cond_resched();
-	}
-
 	/* For cpu_map the remote CPUs can still be using the entries
 	 * (struct bpf_cpu_map_entry).
 	 */
@@ -544,10 +609,9 @@
 		if (!rcpu)
 			continue;
 
-		/* bq flush and cleanup happens after RCU graze-period */
+		/* bq flush and cleanup happens after RCU grace-period */
 		__cpu_map_entry_replace(cmap, i, NULL); /* call_rcu */
 	}
-	free_percpu(cmap->flush_list);
 	bpf_map_area_free(cmap->cpu_map);
 	kfree(cmap);
 }
@@ -569,7 +633,7 @@
 	struct bpf_cpu_map_entry *rcpu =
 		__cpu_map_lookup_elem(map, *(u32 *)key);
 
-	return rcpu ? &rcpu->qsize : NULL;
+	return rcpu ? &rcpu->value : NULL;
 }
 
 static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
@@ -589,7 +653,9 @@
 	return 0;
 }
 
+static int cpu_map_btf_id;
 const struct bpf_map_ops cpu_map_ops = {
+	.map_meta_equal		= bpf_map_meta_equal,
 	.map_alloc		= cpu_map_alloc,
 	.map_free		= cpu_map_free,
 	.map_delete_elem	= cpu_map_delete_elem,
@@ -597,9 +663,11 @@
 	.map_lookup_elem	= cpu_map_lookup_elem,
 	.map_get_next_key	= cpu_map_get_next_key,
 	.map_check_btf		= map_check_no_btf,
+	.map_btf_name		= "bpf_cpu_map",
+	.map_btf_id		= &cpu_map_btf_id,
 };
 
-static int bq_flush_to_queue(struct xdp_bulk_queue *bq, bool in_napi_ctx)
+static void bq_flush_to_queue(struct xdp_bulk_queue *bq)
 {
 	struct bpf_cpu_map_entry *rcpu = bq->obj;
 	unsigned int processed = 0, drops = 0;
@@ -608,7 +676,7 @@
 	int i;
 
 	if (unlikely(!bq->count))
-		return 0;
+		return;
 
 	q = rcpu->queue;
 	spin_lock(&q->producer_lock);
@@ -620,10 +688,7 @@
 		err = __ptr_ring_produce(q, xdpf);
 		if (err) {
 			drops++;
-			if (likely(in_napi_ctx))
-				xdp_return_frame_rx_napi(xdpf);
-			else
-				xdp_return_frame(xdpf);
+			xdp_return_frame_rx_napi(xdpf);
 		}
 		processed++;
 	}
@@ -634,19 +699,18 @@
 
 	/* Feedback loop via tracepoints */
 	trace_xdp_cpumap_enqueue(rcpu->map_id, processed, drops, to_cpu);
-	return 0;
 }
 
 /* Runs under RCU-read-side, plus in softirq under NAPI protection.
  * Thus, safe percpu variable access.
  */
-static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf)
+static void bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf)
 {
-	struct list_head *flush_list = this_cpu_ptr(rcpu->cmap->flush_list);
+	struct list_head *flush_list = this_cpu_ptr(&cpu_map_flush_list);
 	struct xdp_bulk_queue *bq = this_cpu_ptr(rcpu->bulkq);
 
 	if (unlikely(bq->count == CPU_MAP_BULK_SIZE))
-		bq_flush_to_queue(bq, true);
+		bq_flush_to_queue(bq);
 
 	/* Notice, xdp_buff/page MUST be queued here, long enough for
 	 * driver to code invoking us to finished, due to driver
@@ -661,8 +725,6 @@
 
 	if (!bq->flush_node.prev)
 		list_add(&bq->flush_node, flush_list);
-
-	return 0;
 }
 
 int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp,
@@ -670,7 +732,7 @@
 {
 	struct xdp_frame *xdpf;
 
-	xdpf = convert_to_xdp_frame(xdp);
+	xdpf = xdp_convert_buff_to_frame(xdp);
 	if (unlikely(!xdpf))
 		return -EOVERFLOW;
 
@@ -681,16 +743,26 @@
 	return 0;
 }
 
-void __cpu_map_flush(struct bpf_map *map)
+void __cpu_map_flush(void)
 {
-	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
-	struct list_head *flush_list = this_cpu_ptr(cmap->flush_list);
+	struct list_head *flush_list = this_cpu_ptr(&cpu_map_flush_list);
 	struct xdp_bulk_queue *bq, *tmp;
 
 	list_for_each_entry_safe(bq, tmp, flush_list, flush_node) {
-		bq_flush_to_queue(bq, true);
+		bq_flush_to_queue(bq);
 
 		/* If already running, costs spin_lock_irqsave + smb_mb */
 		wake_up_process(bq->obj->kthread);
 	}
 }
+
+static int __init cpu_map_init(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		INIT_LIST_HEAD(&per_cpu(cpu_map_flush_list, cpu));
+	return 0;
+}
+
+subsys_initcall(cpu_map_init);
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 6684696..0114982 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -52,14 +52,11 @@
 #define DEV_CREATE_FLAG_MASK \
 	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
 
-#define DEV_MAP_BULK_SIZE 16
-struct bpf_dtab_netdev;
-
-struct xdp_bulk_queue {
+struct xdp_dev_bulk_queue {
 	struct xdp_frame *q[DEV_MAP_BULK_SIZE];
 	struct list_head flush_node;
+	struct net_device *dev;
 	struct net_device *dev_rx;
-	struct bpf_dtab_netdev *obj;
 	unsigned int count;
 };
 
@@ -67,15 +64,15 @@
 	struct net_device *dev; /* must be first member, due to tracepoint */
 	struct hlist_node index_hlist;
 	struct bpf_dtab *dtab;
-	struct xdp_bulk_queue __percpu *bulkq;
+	struct bpf_prog *xdp_prog;
 	struct rcu_head rcu;
-	unsigned int idx; /* keep track of map index for tracepoint */
+	unsigned int idx;
+	struct bpf_devmap_val val;
 };
 
 struct bpf_dtab {
 	struct bpf_map map;
 	struct bpf_dtab_netdev **netdev_map; /* DEVMAP type only */
-	struct list_head __percpu *flush_list;
 	struct list_head list;
 
 	/* these are only used for DEVMAP_HASH type maps */
@@ -85,6 +82,7 @@
 	u32 n_buckets;
 };
 
+static DEFINE_PER_CPU(struct list_head, dev_flush_list);
 static DEFINE_SPINLOCK(dev_map_lock);
 static LIST_HEAD(dev_map_list);
 
@@ -94,7 +92,7 @@
 	int i;
 	struct hlist_head *hash;
 
-	hash = bpf_map_area_alloc(entries * sizeof(*hash), numa_node);
+	hash = bpf_map_area_alloc((u64) entries * sizeof(*hash), numa_node);
 	if (hash != NULL)
 		for (i = 0; i < entries; i++)
 			INIT_HLIST_HEAD(&hash[i]);
@@ -110,12 +108,18 @@
 
 static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
 {
-	int err, cpu;
-	u64 cost;
+	u32 valsize = attr->value_size;
+	u64 cost = 0;
+	int err;
 
-	/* check sanity of attributes */
+	/* check sanity of attributes. 2 value sizes supported:
+	 * 4 bytes: ifindex
+	 * 8 bytes: ifindex + prog fd
+	 */
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
-	    attr->value_size != 4 || attr->map_flags & ~DEV_CREATE_FLAG_MASK)
+	    (valsize != offsetofend(struct bpf_devmap_val, ifindex) &&
+	     valsize != offsetofend(struct bpf_devmap_val, bpf_prog.fd)) ||
+	    attr->map_flags & ~DEV_CREATE_FLAG_MASK)
 		return -EINVAL;
 
 	/* Lookup returns a pointer straight to dev->ifindex, so make sure the
@@ -126,9 +130,6 @@
 
 	bpf_map_init_from_attr(&dtab->map, attr);
 
-	/* make sure page count doesn't overflow */
-	cost = (u64) sizeof(struct list_head) * num_possible_cpus();
-
 	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
 		dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
 
@@ -144,32 +145,23 @@
 	if (err)
 		return -EINVAL;
 
-	dtab->flush_list = alloc_percpu(struct list_head);
-	if (!dtab->flush_list)
-		goto free_charge;
-
-	for_each_possible_cpu(cpu)
-		INIT_LIST_HEAD(per_cpu_ptr(dtab->flush_list, cpu));
-
 	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
 		dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets,
 							   dtab->map.numa_node);
 		if (!dtab->dev_index_head)
-			goto free_percpu;
+			goto free_charge;
 
 		spin_lock_init(&dtab->index_lock);
 	} else {
-		dtab->netdev_map = bpf_map_area_alloc(dtab->map.max_entries *
+		dtab->netdev_map = bpf_map_area_alloc((u64) dtab->map.max_entries *
 						      sizeof(struct bpf_dtab_netdev *),
 						      dtab->map.numa_node);
 		if (!dtab->netdev_map)
-			goto free_percpu;
+			goto free_charge;
 	}
 
 	return 0;
 
-free_percpu:
-	free_percpu(dtab->flush_list);
 free_charge:
 	bpf_map_charge_finish(&dtab->map.memory);
 	return -ENOMEM;
@@ -203,14 +195,16 @@
 static void dev_map_free(struct bpf_map *map)
 {
 	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
-	int i, cpu;
+	int i;
 
 	/* At this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
 	 * so the programs (can be more than one that used this map) were
-	 * disconnected from events. Wait for outstanding critical sections in
-	 * these programs to complete. The rcu critical section only guarantees
-	 * no further reads against netdev_map. It does __not__ ensure pending
-	 * flush operations (if any) are complete.
+	 * disconnected from events. The following synchronize_rcu() guarantees
+	 * both rcu read critical sections complete and waits for
+	 * preempt-disable regions (NAPI being the relevant context here) so we
+	 * are certain there will be no further reads against the netdev_map and
+	 * all flush operations are complete. Flush operations can only be done
+	 * from NAPI context for this reason.
 	 */
 
 	spin_lock(&dev_map_lock);
@@ -223,18 +217,6 @@
 	/* Make sure prior __dev_map_entry_free() have completed. */
 	rcu_barrier();
 
-	/* To ensure all pending flush operations have completed wait for flush
-	 * list to empty on _all_ cpus.
-	 * Because the above synchronize_rcu() ensures the map is disconnected
-	 * from the program we can assume no new items will be added.
-	 */
-	for_each_online_cpu(cpu) {
-		struct list_head *flush_list = per_cpu_ptr(dtab->flush_list, cpu);
-
-		while (!list_empty(flush_list))
-			cond_resched();
-	}
-
 	if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
 		for (i = 0; i < dtab->n_buckets; i++) {
 			struct bpf_dtab_netdev *dev;
@@ -245,7 +227,8 @@
 
 			hlist_for_each_entry_safe(dev, next, head, index_hlist) {
 				hlist_del_rcu(&dev->index_hlist);
-				free_percpu(dev->bulkq);
+				if (dev->xdp_prog)
+					bpf_prog_put(dev->xdp_prog);
 				dev_put(dev->dev);
 				kfree(dev);
 			}
@@ -260,7 +243,8 @@
 			if (!dev)
 				continue;
 
-			free_percpu(dev->bulkq);
+			if (dev->xdp_prog)
+				bpf_prog_put(dev->xdp_prog);
 			dev_put(dev->dev);
 			kfree(dev);
 		}
@@ -268,7 +252,6 @@
 		bpf_map_area_free(dtab->netdev_map);
 	}
 
-	free_percpu(dtab->flush_list);
 	kfree(dtab);
 }
 
@@ -348,16 +331,24 @@
 	return -ENOENT;
 }
 
-static int bq_xmit_all(struct xdp_bulk_queue *bq, u32 flags,
-		       bool in_napi_ctx)
+bool dev_map_can_have_prog(struct bpf_map *map)
 {
-	struct bpf_dtab_netdev *obj = bq->obj;
-	struct net_device *dev = obj->dev;
+	if ((map->map_type == BPF_MAP_TYPE_DEVMAP ||
+	     map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) &&
+	    map->value_size != offsetofend(struct bpf_devmap_val, ifindex))
+		return true;
+
+	return false;
+}
+
+static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags)
+{
+	struct net_device *dev = bq->dev;
 	int sent = 0, drops = 0, err = 0;
 	int i;
 
 	if (unlikely(!bq->count))
-		return 0;
+		return;
 
 	for (i = 0; i < bq->count; i++) {
 		struct xdp_frame *xdpf = bq->q[i];
@@ -375,11 +366,10 @@
 out:
 	bq->count = 0;
 
-	trace_xdp_devmap_xmit(&obj->dtab->map, obj->idx,
-			      sent, drops, bq->dev_rx, dev, err);
+	trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, drops, err);
 	bq->dev_rx = NULL;
 	__list_del_clearprev(&bq->flush_node);
-	return 0;
+	return;
 error:
 	/* If ndo_xdp_xmit fails with an errno, no frames have been
 	 * xmit'ed and it's our responsibility to them free all.
@@ -387,33 +377,29 @@
 	for (i = 0; i < bq->count; i++) {
 		struct xdp_frame *xdpf = bq->q[i];
 
-		/* RX path under NAPI protection, can return frames faster */
-		if (likely(in_napi_ctx))
-			xdp_return_frame_rx_napi(xdpf);
-		else
-			xdp_return_frame(xdpf);
+		xdp_return_frame_rx_napi(xdpf);
 		drops++;
 	}
 	goto out;
 }
 
-/* __dev_map_flush is called from xdp_do_flush_map() which _must_ be signaled
+/* __dev_flush is called from xdp_do_flush() which _must_ be signaled
  * from the driver before returning from its napi->poll() routine. The poll()
  * routine is called either from busy_poll context or net_rx_action signaled
  * from NET_RX_SOFTIRQ. Either way the poll routine must complete before the
  * net device can be torn down. On devmap tear down we ensure the flush list
  * is empty before completing to ensure all flush operations have completed.
+ * When drivers update the bpf program they may need to ensure any flush ops
+ * are also complete. Using synchronize_rcu or call_rcu will suffice for this
+ * because both wait for napi context to exit.
  */
-void __dev_map_flush(struct bpf_map *map)
+void __dev_flush(void)
 {
-	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
-	struct list_head *flush_list = this_cpu_ptr(dtab->flush_list);
-	struct xdp_bulk_queue *bq, *tmp;
+	struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
+	struct xdp_dev_bulk_queue *bq, *tmp;
 
-	rcu_read_lock();
 	list_for_each_entry_safe(bq, tmp, flush_list, flush_node)
-		bq_xmit_all(bq, XDP_XMIT_FLUSH, true);
-	rcu_read_unlock();
+		bq_xmit_all(bq, XDP_XMIT_FLUSH);
 }
 
 /* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or
@@ -435,15 +421,14 @@
 /* Runs under RCU-read-side, plus in softirq under NAPI protection.
  * Thus, safe percpu variable access.
  */
-static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf,
-		      struct net_device *dev_rx)
-
+static void bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf,
+		       struct net_device *dev_rx)
 {
-	struct list_head *flush_list = this_cpu_ptr(obj->dtab->flush_list);
-	struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq);
+	struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
+	struct xdp_dev_bulk_queue *bq = this_cpu_ptr(dev->xdp_bulkq);
 
 	if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
-		bq_xmit_all(bq, 0, true);
+		bq_xmit_all(bq, 0);
 
 	/* Ingress dev_rx will be the same for all xdp_frame's in
 	 * bulk_queue, because bq stored per-CPU and must be flushed
@@ -456,14 +441,11 @@
 
 	if (!bq->flush_node.prev)
 		list_add(&bq->flush_node, flush_list);
-
-	return 0;
 }
 
-int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
-		    struct net_device *dev_rx)
+static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+			       struct net_device *dev_rx)
 {
-	struct net_device *dev = dst->dev;
 	struct xdp_frame *xdpf;
 	int err;
 
@@ -474,11 +456,59 @@
 	if (unlikely(err))
 		return err;
 
-	xdpf = convert_to_xdp_frame(xdp);
+	xdpf = xdp_convert_buff_to_frame(xdp);
 	if (unlikely(!xdpf))
 		return -EOVERFLOW;
 
-	return bq_enqueue(dst, xdpf, dev_rx);
+	bq_enqueue(dev, xdpf, dev_rx);
+	return 0;
+}
+
+static struct xdp_buff *dev_map_run_prog(struct net_device *dev,
+					 struct xdp_buff *xdp,
+					 struct bpf_prog *xdp_prog)
+{
+	struct xdp_txq_info txq = { .dev = dev };
+	u32 act;
+
+	xdp_set_data_meta_invalid(xdp);
+	xdp->txq = &txq;
+
+	act = bpf_prog_run_xdp(xdp_prog, xdp);
+	switch (act) {
+	case XDP_PASS:
+		return xdp;
+	case XDP_DROP:
+		break;
+	default:
+		bpf_warn_invalid_xdp_action(act);
+		fallthrough;
+	case XDP_ABORTED:
+		trace_xdp_exception(dev, xdp_prog, act);
+		break;
+	}
+
+	xdp_return_buff(xdp);
+	return NULL;
+}
+
+int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+		    struct net_device *dev_rx)
+{
+	return __xdp_enqueue(dev, xdp, dev_rx);
+}
+
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
+		    struct net_device *dev_rx)
+{
+	struct net_device *dev = dst->dev;
+
+	if (dst->xdp_prog) {
+		xdp = dev_map_run_prog(dev, xdp, dst->xdp_prog);
+		if (!xdp)
+			return 0;
+	}
+	return __xdp_enqueue(dev, xdp, dev_rx);
 }
 
 int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
@@ -498,33 +528,15 @@
 static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
 {
 	struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key);
-	struct net_device *dev = obj ? obj->dev : NULL;
 
-	return dev ? &dev->ifindex : NULL;
+	return obj ? &obj->val : NULL;
 }
 
 static void *dev_map_hash_lookup_elem(struct bpf_map *map, void *key)
 {
 	struct bpf_dtab_netdev *obj = __dev_map_hash_lookup_elem(map,
 								*(u32 *)key);
-	struct net_device *dev = obj ? obj->dev : NULL;
-
-	return dev ? &dev->ifindex : NULL;
-}
-
-static void dev_map_flush_old(struct bpf_dtab_netdev *dev)
-{
-	if (dev->dev->netdev_ops->ndo_xdp_xmit) {
-		struct xdp_bulk_queue *bq;
-		int cpu;
-
-		rcu_read_lock();
-		for_each_online_cpu(cpu) {
-			bq = per_cpu_ptr(dev->bulkq, cpu);
-			bq_xmit_all(bq, XDP_XMIT_FLUSH, false);
-		}
-		rcu_read_unlock();
-	}
+	return obj ? &obj->val : NULL;
 }
 
 static void __dev_map_entry_free(struct rcu_head *rcu)
@@ -532,8 +544,8 @@
 	struct bpf_dtab_netdev *dev;
 
 	dev = container_of(rcu, struct bpf_dtab_netdev, rcu);
-	dev_map_flush_old(dev);
-	free_percpu(dev->bulkq);
+	if (dev->xdp_prog)
+		bpf_prog_put(dev->xdp_prog);
 	dev_put(dev->dev);
 	kfree(dev);
 }
@@ -548,12 +560,11 @@
 		return -EINVAL;
 
 	/* Use call_rcu() here to ensure any rcu critical sections have
-	 * completed, but this does not guarantee a flush has happened
-	 * yet. Because driver side rcu_read_lock/unlock only protects the
-	 * running XDP program. However, for pending flush operations the
-	 * dev and ctx are stored in another per cpu map. And additionally,
-	 * the driver tear down ensures all soft irqs are complete before
-	 * removing the net device in the case of dev_put equals zero.
+	 * completed as well as any flush operations because call_rcu
+	 * will wait for preempt-disable region to complete, NAPI in this
+	 * context.  And additionally, the driver tear down ensures all
+	 * soft irqs are complete before removing the net device in the
+	 * case of dev_put equals zero.
 	 */
 	old_dev = xchg(&dtab->netdev_map[k], NULL);
 	if (old_dev)
@@ -585,41 +596,49 @@
 
 static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
 						    struct bpf_dtab *dtab,
-						    u32 ifindex,
+						    struct bpf_devmap_val *val,
 						    unsigned int idx)
 {
-	gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN;
+	struct bpf_prog *prog = NULL;
 	struct bpf_dtab_netdev *dev;
-	struct xdp_bulk_queue *bq;
-	int cpu;
 
-	dev = kmalloc_node(sizeof(*dev), gfp, dtab->map.numa_node);
+	dev = kmalloc_node(sizeof(*dev), GFP_ATOMIC | __GFP_NOWARN,
+			   dtab->map.numa_node);
 	if (!dev)
 		return ERR_PTR(-ENOMEM);
 
-	dev->bulkq = __alloc_percpu_gfp(sizeof(*dev->bulkq),
-					sizeof(void *), gfp);
-	if (!dev->bulkq) {
-		kfree(dev);
-		return ERR_PTR(-ENOMEM);
-	}
+	dev->dev = dev_get_by_index(net, val->ifindex);
+	if (!dev->dev)
+		goto err_out;
 
-	for_each_possible_cpu(cpu) {
-		bq = per_cpu_ptr(dev->bulkq, cpu);
-		bq->obj = dev;
-	}
-
-	dev->dev = dev_get_by_index(net, ifindex);
-	if (!dev->dev) {
-		free_percpu(dev->bulkq);
-		kfree(dev);
-		return ERR_PTR(-EINVAL);
+	if (val->bpf_prog.fd > 0) {
+		prog = bpf_prog_get_type_dev(val->bpf_prog.fd,
+					     BPF_PROG_TYPE_XDP, false);
+		if (IS_ERR(prog))
+			goto err_put_dev;
+		if (prog->expected_attach_type != BPF_XDP_DEVMAP)
+			goto err_put_prog;
 	}
 
 	dev->idx = idx;
 	dev->dtab = dtab;
+	if (prog) {
+		dev->xdp_prog = prog;
+		dev->val.bpf_prog.id = prog->aux->id;
+	} else {
+		dev->xdp_prog = NULL;
+		dev->val.bpf_prog.id = 0;
+	}
+	dev->val.ifindex = val->ifindex;
 
 	return dev;
+err_put_prog:
+	bpf_prog_put(prog);
+err_put_dev:
+	dev_put(dev->dev);
+err_out:
+	kfree(dev);
+	return ERR_PTR(-EINVAL);
 }
 
 static int __dev_map_update_elem(struct net *net, struct bpf_map *map,
@@ -627,7 +646,7 @@
 {
 	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
 	struct bpf_dtab_netdev *dev, *old_dev;
-	u32 ifindex = *(u32 *)value;
+	struct bpf_devmap_val val = {};
 	u32 i = *(u32 *)key;
 
 	if (unlikely(map_flags > BPF_EXIST))
@@ -637,10 +656,16 @@
 	if (unlikely(map_flags == BPF_NOEXIST))
 		return -EEXIST;
 
-	if (!ifindex) {
+	/* already verified value_size <= sizeof val */
+	memcpy(&val, value, map->value_size);
+
+	if (!val.ifindex) {
 		dev = NULL;
+		/* can not specify fd if ifindex is 0 */
+		if (val.bpf_prog.fd > 0)
+			return -EINVAL;
 	} else {
-		dev = __dev_map_alloc_node(net, dtab, ifindex, i);
+		dev = __dev_map_alloc_node(net, dtab, &val, i);
 		if (IS_ERR(dev))
 			return PTR_ERR(dev);
 	}
@@ -668,12 +693,15 @@
 {
 	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
 	struct bpf_dtab_netdev *dev, *old_dev;
-	u32 ifindex = *(u32 *)value;
+	struct bpf_devmap_val val = {};
 	u32 idx = *(u32 *)key;
 	unsigned long flags;
 	int err = -EEXIST;
 
-	if (unlikely(map_flags > BPF_EXIST || !ifindex))
+	/* already verified value_size <= sizeof val */
+	memcpy(&val, value, map->value_size);
+
+	if (unlikely(map_flags > BPF_EXIST || !val.ifindex))
 		return -EINVAL;
 
 	spin_lock_irqsave(&dtab->index_lock, flags);
@@ -682,7 +710,7 @@
 	if (old_dev && (map_flags & BPF_NOEXIST))
 		goto out_err;
 
-	dev = __dev_map_alloc_node(net, dtab, ifindex, idx);
+	dev = __dev_map_alloc_node(net, dtab, &val, idx);
 	if (IS_ERR(dev)) {
 		err = PTR_ERR(dev);
 		goto out_err;
@@ -720,7 +748,9 @@
 					 map, key, value, map_flags);
 }
 
+static int dev_map_btf_id;
 const struct bpf_map_ops dev_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc = dev_map_alloc,
 	.map_free = dev_map_free,
 	.map_get_next_key = dev_map_get_next_key,
@@ -728,9 +758,13 @@
 	.map_update_elem = dev_map_update_elem,
 	.map_delete_elem = dev_map_delete_elem,
 	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_dtab",
+	.map_btf_id = &dev_map_btf_id,
 };
 
+static int dev_map_hash_map_btf_id;
 const struct bpf_map_ops dev_map_hash_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc = dev_map_alloc,
 	.map_free = dev_map_free,
 	.map_get_next_key = dev_map_hash_get_next_key,
@@ -738,6 +772,8 @@
 	.map_update_elem = dev_map_hash_update_elem,
 	.map_delete_elem = dev_map_hash_delete_elem,
 	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_dtab",
+	.map_btf_id = &dev_map_hash_map_btf_id,
 };
 
 static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab,
@@ -771,9 +807,21 @@
 {
 	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
 	struct bpf_dtab *dtab;
-	int i;
+	int i, cpu;
 
 	switch (event) {
+	case NETDEV_REGISTER:
+		if (!netdev->netdev_ops->ndo_xdp_xmit || netdev->xdp_bulkq)
+			break;
+
+		/* will be freed in free_netdev() */
+		netdev->xdp_bulkq = alloc_percpu(struct xdp_dev_bulk_queue);
+		if (!netdev->xdp_bulkq)
+			return NOTIFY_BAD;
+
+		for_each_possible_cpu(cpu)
+			per_cpu_ptr(netdev->xdp_bulkq, cpu)->dev = netdev;
+		break;
 	case NETDEV_UNREGISTER:
 		/* This rcu_read_lock/unlock pair is needed because
 		 * dev_map_list is an RCU list AND to ensure a delete
@@ -813,10 +861,15 @@
 
 static int __init dev_map_init(void)
 {
+	int cpu;
+
 	/* Assure tracepoint shadow struct _bpf_dtab_netdev is in sync */
 	BUILD_BUG_ON(offsetof(struct bpf_dtab_netdev, dev) !=
 		     offsetof(struct _bpf_dtab_netdev, dev));
 	register_netdevice_notifier(&dev_map_notifier);
+
+	for_each_possible_cpu(cpu)
+		INIT_LIST_HEAD(&per_cpu(dev_flush_list, cpu));
 	return 0;
 }
 
diff --git a/kernel/bpf/dispatcher.c b/kernel/bpf/dispatcher.c
new file mode 100644
index 0000000..2444bd1
--- /dev/null
+++ b/kernel/bpf/dispatcher.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2019 Intel Corporation. */
+
+#include <linux/hash.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+
+/* The BPF dispatcher is a multiway branch code generator. The
+ * dispatcher is a mechanism to avoid the performance penalty of an
+ * indirect call, which is expensive when retpolines are enabled. A
+ * dispatch client registers a BPF program into the dispatcher, and if
+ * there is available room in the dispatcher a direct call to the BPF
+ * program will be generated. All calls to the BPF programs called via
+ * the dispatcher will then be a direct call, instead of an
+ * indirect. The dispatcher hijacks a trampoline function it via the
+ * __fentry__ of the trampoline. The trampoline function has the
+ * following signature:
+ *
+ * unsigned int trampoline(const void *ctx, const struct bpf_insn *insnsi,
+ *                         unsigned int (*bpf_func)(const void *,
+ *                                                  const struct bpf_insn *));
+ */
+
+static struct bpf_dispatcher_prog *bpf_dispatcher_find_prog(
+	struct bpf_dispatcher *d, struct bpf_prog *prog)
+{
+	int i;
+
+	for (i = 0; i < BPF_DISPATCHER_MAX; i++) {
+		if (prog == d->progs[i].prog)
+			return &d->progs[i];
+	}
+	return NULL;
+}
+
+static struct bpf_dispatcher_prog *bpf_dispatcher_find_free(
+	struct bpf_dispatcher *d)
+{
+	return bpf_dispatcher_find_prog(d, NULL);
+}
+
+static bool bpf_dispatcher_add_prog(struct bpf_dispatcher *d,
+				    struct bpf_prog *prog)
+{
+	struct bpf_dispatcher_prog *entry;
+
+	if (!prog)
+		return false;
+
+	entry = bpf_dispatcher_find_prog(d, prog);
+	if (entry) {
+		refcount_inc(&entry->users);
+		return false;
+	}
+
+	entry = bpf_dispatcher_find_free(d);
+	if (!entry)
+		return false;
+
+	bpf_prog_inc(prog);
+	entry->prog = prog;
+	refcount_set(&entry->users, 1);
+	d->num_progs++;
+	return true;
+}
+
+static bool bpf_dispatcher_remove_prog(struct bpf_dispatcher *d,
+				       struct bpf_prog *prog)
+{
+	struct bpf_dispatcher_prog *entry;
+
+	if (!prog)
+		return false;
+
+	entry = bpf_dispatcher_find_prog(d, prog);
+	if (!entry)
+		return false;
+
+	if (refcount_dec_and_test(&entry->users)) {
+		entry->prog = NULL;
+		bpf_prog_put(prog);
+		d->num_progs--;
+		return true;
+	}
+	return false;
+}
+
+int __weak arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs)
+{
+	return -ENOTSUPP;
+}
+
+static int bpf_dispatcher_prepare(struct bpf_dispatcher *d, void *image)
+{
+	s64 ips[BPF_DISPATCHER_MAX] = {}, *ipsp = &ips[0];
+	int i;
+
+	for (i = 0; i < BPF_DISPATCHER_MAX; i++) {
+		if (d->progs[i].prog)
+			*ipsp++ = (s64)(uintptr_t)d->progs[i].prog->bpf_func;
+	}
+	return arch_prepare_bpf_dispatcher(image, &ips[0], d->num_progs);
+}
+
+static void bpf_dispatcher_update(struct bpf_dispatcher *d, int prev_num_progs)
+{
+	void *old, *new;
+	u32 noff;
+	int err;
+
+	if (!prev_num_progs) {
+		old = NULL;
+		noff = 0;
+	} else {
+		old = d->image + d->image_off;
+		noff = d->image_off ^ (PAGE_SIZE / 2);
+	}
+
+	new = d->num_progs ? d->image + noff : NULL;
+	if (new) {
+		if (bpf_dispatcher_prepare(d, new))
+			return;
+	}
+
+	err = bpf_arch_text_poke(d->func, BPF_MOD_JUMP, old, new);
+	if (err || !new)
+		return;
+
+	d->image_off = noff;
+}
+
+void bpf_dispatcher_change_prog(struct bpf_dispatcher *d, struct bpf_prog *from,
+				struct bpf_prog *to)
+{
+	bool changed = false;
+	int prev_num_progs;
+
+	if (from == to)
+		return;
+
+	mutex_lock(&d->mutex);
+	if (!d->image) {
+		d->image = bpf_jit_alloc_exec_page();
+		if (!d->image)
+			goto out;
+		bpf_image_ksym_add(d->image, &d->ksym);
+	}
+
+	prev_num_progs = d->num_progs;
+	changed |= bpf_dispatcher_remove_prog(d, from);
+	changed |= bpf_dispatcher_add_prog(d, to);
+
+	if (!changed)
+		goto out;
+
+	bpf_dispatcher_update(d, prev_num_progs);
+out:
+	mutex_unlock(&d->mutex);
+}
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 03a6758..6c444e8 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -9,6 +9,7 @@
 #include <linux/rculist_nulls.h>
 #include <linux/random.h>
 #include <uapi/linux/btf.h>
+#include <linux/rcupdate_trace.h>
 #include "percpu_freelist.h"
 #include "bpf_lru_list.h"
 #include "map_in_map.h"
@@ -17,9 +18,72 @@
 	(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE |	\
 	 BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED)
 
+#define BATCH_OPS(_name)			\
+	.map_lookup_batch =			\
+	_name##_map_lookup_batch,		\
+	.map_lookup_and_delete_batch =		\
+	_name##_map_lookup_and_delete_batch,	\
+	.map_update_batch =			\
+	generic_map_update_batch,		\
+	.map_delete_batch =			\
+	generic_map_delete_batch
+
+/*
+ * The bucket lock has two protection scopes:
+ *
+ * 1) Serializing concurrent operations from BPF programs on differrent
+ *    CPUs
+ *
+ * 2) Serializing concurrent operations from BPF programs and sys_bpf()
+ *
+ * BPF programs can execute in any context including perf, kprobes and
+ * tracing. As there are almost no limits where perf, kprobes and tracing
+ * can be invoked from the lock operations need to be protected against
+ * deadlocks. Deadlocks can be caused by recursion and by an invocation in
+ * the lock held section when functions which acquire this lock are invoked
+ * from sys_bpf(). BPF recursion is prevented by incrementing the per CPU
+ * variable bpf_prog_active, which prevents BPF programs attached to perf
+ * events, kprobes and tracing to be invoked before the prior invocation
+ * from one of these contexts completed. sys_bpf() uses the same mechanism
+ * by pinning the task to the current CPU and incrementing the recursion
+ * protection accross the map operation.
+ *
+ * This has subtle implications on PREEMPT_RT. PREEMPT_RT forbids certain
+ * operations like memory allocations (even with GFP_ATOMIC) from atomic
+ * contexts. This is required because even with GFP_ATOMIC the memory
+ * allocator calls into code pathes which acquire locks with long held lock
+ * sections. To ensure the deterministic behaviour these locks are regular
+ * spinlocks, which are converted to 'sleepable' spinlocks on RT. The only
+ * true atomic contexts on an RT kernel are the low level hardware
+ * handling, scheduling, low level interrupt handling, NMIs etc. None of
+ * these contexts should ever do memory allocations.
+ *
+ * As regular device interrupt handlers and soft interrupts are forced into
+ * thread context, the existing code which does
+ *   spin_lock*(); alloc(GPF_ATOMIC); spin_unlock*();
+ * just works.
+ *
+ * In theory the BPF locks could be converted to regular spinlocks as well,
+ * but the bucket locks and percpu_freelist locks can be taken from
+ * arbitrary contexts (perf, kprobes, tracepoints) which are required to be
+ * atomic contexts even on RT. These mechanisms require preallocated maps,
+ * so there is no need to invoke memory allocations within the lock held
+ * sections.
+ *
+ * BPF maps which need dynamic allocation are only used from (forced)
+ * thread context on RT and can therefore use regular spinlocks which in
+ * turn allows to invoke memory allocations from the lock held section.
+ *
+ * On a non RT kernel this distinction is neither possible nor required.
+ * spinlock maps to raw_spinlock and the extra code is optimized out by the
+ * compiler.
+ */
 struct bucket {
 	struct hlist_nulls_head head;
-	raw_spinlock_t lock;
+	union {
+		raw_spinlock_t raw_lock;
+		spinlock_t     lock;
+	};
 };
 
 struct bpf_htab {
@@ -46,6 +110,7 @@
 			union {
 				struct bpf_htab *htab;
 				struct pcpu_freelist_node fnode;
+				struct htab_elem *batch_flink;
 			};
 		};
 	};
@@ -54,9 +119,54 @@
 		struct bpf_lru_node lru_node;
 	};
 	u32 hash;
-	char key[0] __aligned(8);
+	char key[] __aligned(8);
 };
 
+static inline bool htab_is_prealloc(const struct bpf_htab *htab)
+{
+	return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
+}
+
+static inline bool htab_use_raw_lock(const struct bpf_htab *htab)
+{
+	return (!IS_ENABLED(CONFIG_PREEMPT_RT) || htab_is_prealloc(htab));
+}
+
+static void htab_init_buckets(struct bpf_htab *htab)
+{
+	unsigned i;
+
+	for (i = 0; i < htab->n_buckets; i++) {
+		INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
+		if (htab_use_raw_lock(htab))
+			raw_spin_lock_init(&htab->buckets[i].raw_lock);
+		else
+			spin_lock_init(&htab->buckets[i].lock);
+	}
+}
+
+static inline unsigned long htab_lock_bucket(const struct bpf_htab *htab,
+					     struct bucket *b)
+{
+	unsigned long flags;
+
+	if (htab_use_raw_lock(htab))
+		raw_spin_lock_irqsave(&b->raw_lock, flags);
+	else
+		spin_lock_irqsave(&b->lock, flags);
+	return flags;
+}
+
+static inline void htab_unlock_bucket(const struct bpf_htab *htab,
+				      struct bucket *b,
+				      unsigned long flags)
+{
+	if (htab_use_raw_lock(htab))
+		raw_spin_unlock_irqrestore(&b->raw_lock, flags);
+	else
+		spin_unlock_irqrestore(&b->lock, flags);
+}
+
 static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
 
 static bool htab_is_lru(const struct bpf_htab *htab)
@@ -71,11 +181,6 @@
 		htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
 }
 
-static bool htab_is_prealloc(const struct bpf_htab *htab)
-{
-	return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
-}
-
 static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
 				     void __percpu *pptr)
 {
@@ -116,6 +221,17 @@
 	bpf_map_area_free(htab->elems);
 }
 
+/* The LRU list has a lock (lru_lock). Each htab bucket has a lock
+ * (bucket_lock). If both locks need to be acquired together, the lock
+ * order is always lru_lock -> bucket_lock and this only happens in
+ * bpf_lru_list.c logic. For example, certain code path of
+ * bpf_lru_pop_free(), which is called by function prealloc_lru_pop(),
+ * will acquire lru_lock first followed by acquiring bucket_lock.
+ *
+ * In hashtab.c, to avoid deadlock, lock acquisition of
+ * bucket_lock followed by lru_lock is not allowed. In such cases,
+ * bucket_lock needs to be released first before acquiring lru_lock.
+ */
 static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
 					  u32 hash)
 {
@@ -244,9 +360,9 @@
 	BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) !=
 		     offsetof(struct htab_elem, hash_node.pprev));
 
-	if (lru && !capable(CAP_SYS_ADMIN))
+	if (lru && !bpf_capable())
 		/* LRU implementation is much complicated than other
-		 * maps.  Hence, limit to CAP_SYS_ADMIN for now.
+		 * maps.  Hence, limit to CAP_BPF.
 		 */
 		return -EPERM;
 
@@ -306,8 +422,8 @@
 	bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
 	bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
 	struct bpf_htab *htab;
-	int err, i;
 	u64 cost;
+	int err;
 
 	htab = kzalloc(sizeof(*htab), GFP_USER);
 	if (!htab)
@@ -369,10 +485,7 @@
 	else
 		htab->hashrnd = get_random_int();
 
-	for (i = 0; i < htab->n_buckets; i++) {
-		INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
-		raw_spin_lock_init(&htab->buckets[i].lock);
-	}
+	htab_init_buckets(htab);
 
 	if (prealloc) {
 		err = prealloc_init(htab);
@@ -465,8 +578,7 @@
 	struct htab_elem *l;
 	u32 hash, key_size;
 
-	/* Must be called with rcu_read_lock. */
-	WARN_ON_ONCE(!rcu_read_lock_held());
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
 
 	key_size = map->key_size;
 
@@ -500,7 +612,7 @@
  * bpf_prog
  *   __htab_map_lookup_elem
  */
-static u32 htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
+static int htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
 {
 	struct bpf_insn *insn = insn_buf;
 	const int ret = BPF_REG_0;
@@ -539,7 +651,7 @@
 	return __htab_lru_map_lookup_elem(map, key, false);
 }
 
-static u32 htab_lru_map_gen_lookup(struct bpf_map *map,
+static int htab_lru_map_gen_lookup(struct bpf_map *map,
 				   struct bpf_insn *insn_buf)
 {
 	struct bpf_insn *insn = insn_buf;
@@ -580,7 +692,7 @@
 	b = __select_bucket(htab, tgt_l->hash);
 	head = &b->head;
 
-	raw_spin_lock_irqsave(&b->lock, flags);
+	flags = htab_lock_bucket(htab, b);
 
 	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
 		if (l == tgt_l) {
@@ -588,7 +700,7 @@
 			break;
 		}
 
-	raw_spin_unlock_irqrestore(&b->lock, flags);
+	htab_unlock_bucket(htab, b, flags);
 
 	return l == tgt_l;
 }
@@ -855,7 +967,7 @@
 		/* unknown flags */
 		return -EINVAL;
 
-	WARN_ON_ONCE(!rcu_read_lock_held());
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
 
 	key_size = map->key_size;
 
@@ -886,8 +998,7 @@
 		 */
 	}
 
-	/* bpf_map_update_elem() can be called in_irq() */
-	raw_spin_lock_irqsave(&b->lock, flags);
+	flags = htab_lock_bucket(htab, b);
 
 	l_old = lookup_elem_raw(head, hash, key, key_size);
 
@@ -928,7 +1039,7 @@
 	}
 	ret = 0;
 err:
-	raw_spin_unlock_irqrestore(&b->lock, flags);
+	htab_unlock_bucket(htab, b, flags);
 	return ret;
 }
 
@@ -947,7 +1058,7 @@
 		/* unknown flags */
 		return -EINVAL;
 
-	WARN_ON_ONCE(!rcu_read_lock_held());
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
 
 	key_size = map->key_size;
 
@@ -966,8 +1077,7 @@
 		return -ENOMEM;
 	memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size);
 
-	/* bpf_map_update_elem() can be called in_irq() */
-	raw_spin_lock_irqsave(&b->lock, flags);
+	flags = htab_lock_bucket(htab, b);
 
 	l_old = lookup_elem_raw(head, hash, key, key_size);
 
@@ -986,7 +1096,7 @@
 	ret = 0;
 
 err:
-	raw_spin_unlock_irqrestore(&b->lock, flags);
+	htab_unlock_bucket(htab, b, flags);
 
 	if (ret)
 		bpf_lru_push_free(&htab->lru, &l_new->lru_node);
@@ -1021,8 +1131,7 @@
 	b = __select_bucket(htab, hash);
 	head = &b->head;
 
-	/* bpf_map_update_elem() can be called in_irq() */
-	raw_spin_lock_irqsave(&b->lock, flags);
+	flags = htab_lock_bucket(htab, b);
 
 	l_old = lookup_elem_raw(head, hash, key, key_size);
 
@@ -1045,7 +1154,7 @@
 	}
 	ret = 0;
 err:
-	raw_spin_unlock_irqrestore(&b->lock, flags);
+	htab_unlock_bucket(htab, b, flags);
 	return ret;
 }
 
@@ -1085,8 +1194,7 @@
 			return -ENOMEM;
 	}
 
-	/* bpf_map_update_elem() can be called in_irq() */
-	raw_spin_lock_irqsave(&b->lock, flags);
+	flags = htab_lock_bucket(htab, b);
 
 	l_old = lookup_elem_raw(head, hash, key, key_size);
 
@@ -1108,7 +1216,7 @@
 	}
 	ret = 0;
 err:
-	raw_spin_unlock_irqrestore(&b->lock, flags);
+	htab_unlock_bucket(htab, b, flags);
 	if (l_new)
 		bpf_lru_push_free(&htab->lru, &l_new->lru_node);
 	return ret;
@@ -1138,7 +1246,7 @@
 	u32 hash, key_size;
 	int ret = -ENOENT;
 
-	WARN_ON_ONCE(!rcu_read_lock_held());
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
 
 	key_size = map->key_size;
 
@@ -1146,7 +1254,7 @@
 	b = __select_bucket(htab, hash);
 	head = &b->head;
 
-	raw_spin_lock_irqsave(&b->lock, flags);
+	flags = htab_lock_bucket(htab, b);
 
 	l = lookup_elem_raw(head, hash, key, key_size);
 
@@ -1156,7 +1264,7 @@
 		ret = 0;
 	}
 
-	raw_spin_unlock_irqrestore(&b->lock, flags);
+	htab_unlock_bucket(htab, b, flags);
 	return ret;
 }
 
@@ -1170,7 +1278,7 @@
 	u32 hash, key_size;
 	int ret = -ENOENT;
 
-	WARN_ON_ONCE(!rcu_read_lock_held());
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
 
 	key_size = map->key_size;
 
@@ -1178,7 +1286,7 @@
 	b = __select_bucket(htab, hash);
 	head = &b->head;
 
-	raw_spin_lock_irqsave(&b->lock, flags);
+	flags = htab_lock_bucket(htab, b);
 
 	l = lookup_elem_raw(head, hash, key, key_size);
 
@@ -1187,7 +1295,7 @@
 		ret = 0;
 	}
 
-	raw_spin_unlock_irqrestore(&b->lock, flags);
+	htab_unlock_bucket(htab, b, flags);
 	if (l)
 		bpf_lru_push_free(&htab->lru, &l->lru_node);
 	return ret;
@@ -1214,12 +1322,10 @@
 {
 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 
-	/* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
-	 * so the programs (can be more than one that used this map) were
-	 * disconnected from events. Wait for outstanding critical sections in
-	 * these programs to complete
+	/* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback.
+	 * bpf_free_used_maps() is called after bpf prog is no longer executing.
+	 * There is no need to synchronize_rcu() here to protect map elements.
 	 */
-	synchronize_rcu();
 
 	/* some of free_htab_elem() callbacks for elements of this map may
 	 * not have executed. Wait for them.
@@ -1256,7 +1362,474 @@
 	rcu_read_unlock();
 }
 
+static int
+__htab_map_lookup_and_delete_batch(struct bpf_map *map,
+				   const union bpf_attr *attr,
+				   union bpf_attr __user *uattr,
+				   bool do_delete, bool is_lru_map,
+				   bool is_percpu)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	u32 bucket_cnt, total, key_size, value_size, roundup_key_size;
+	void *keys = NULL, *values = NULL, *value, *dst_key, *dst_val;
+	void __user *uvalues = u64_to_user_ptr(attr->batch.values);
+	void __user *ukeys = u64_to_user_ptr(attr->batch.keys);
+	void *ubatch = u64_to_user_ptr(attr->batch.in_batch);
+	u32 batch, max_count, size, bucket_size;
+	struct htab_elem *node_to_free = NULL;
+	u64 elem_map_flags, map_flags;
+	struct hlist_nulls_head *head;
+	struct hlist_nulls_node *n;
+	unsigned long flags = 0;
+	bool locked = false;
+	struct htab_elem *l;
+	struct bucket *b;
+	int ret = 0;
+
+	elem_map_flags = attr->batch.elem_flags;
+	if ((elem_map_flags & ~BPF_F_LOCK) ||
+	    ((elem_map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
+		return -EINVAL;
+
+	map_flags = attr->batch.flags;
+	if (map_flags)
+		return -EINVAL;
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
+	batch = 0;
+	if (ubatch && copy_from_user(&batch, ubatch, sizeof(batch)))
+		return -EFAULT;
+
+	if (batch >= htab->n_buckets)
+		return -ENOENT;
+
+	key_size = htab->map.key_size;
+	roundup_key_size = round_up(htab->map.key_size, 8);
+	value_size = htab->map.value_size;
+	size = round_up(value_size, 8);
+	if (is_percpu)
+		value_size = size * num_possible_cpus();
+	total = 0;
+	/* while experimenting with hash tables with sizes ranging from 10 to
+	 * 1000, it was observed that a bucket can have upto 5 entries.
+	 */
+	bucket_size = 5;
+
+alloc:
+	/* We cannot do copy_from_user or copy_to_user inside
+	 * the rcu_read_lock. Allocate enough space here.
+	 */
+	keys = kvmalloc_array(key_size, bucket_size, GFP_USER | __GFP_NOWARN);
+	values = kvmalloc_array(value_size, bucket_size, GFP_USER | __GFP_NOWARN);
+	if (!keys || !values) {
+		ret = -ENOMEM;
+		goto after_loop;
+	}
+
+again:
+	bpf_disable_instrumentation();
+	rcu_read_lock();
+again_nocopy:
+	dst_key = keys;
+	dst_val = values;
+	b = &htab->buckets[batch];
+	head = &b->head;
+	/* do not grab the lock unless need it (bucket_cnt > 0). */
+	if (locked)
+		flags = htab_lock_bucket(htab, b);
+
+	bucket_cnt = 0;
+	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
+		bucket_cnt++;
+
+	if (bucket_cnt && !locked) {
+		locked = true;
+		goto again_nocopy;
+	}
+
+	if (bucket_cnt > (max_count - total)) {
+		if (total == 0)
+			ret = -ENOSPC;
+		/* Note that since bucket_cnt > 0 here, it is implicit
+		 * that the locked was grabbed, so release it.
+		 */
+		htab_unlock_bucket(htab, b, flags);
+		rcu_read_unlock();
+		bpf_enable_instrumentation();
+		goto after_loop;
+	}
+
+	if (bucket_cnt > bucket_size) {
+		bucket_size = bucket_cnt;
+		/* Note that since bucket_cnt > 0 here, it is implicit
+		 * that the locked was grabbed, so release it.
+		 */
+		htab_unlock_bucket(htab, b, flags);
+		rcu_read_unlock();
+		bpf_enable_instrumentation();
+		kvfree(keys);
+		kvfree(values);
+		goto alloc;
+	}
+
+	/* Next block is only safe to run if you have grabbed the lock */
+	if (!locked)
+		goto next_batch;
+
+	hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
+		memcpy(dst_key, l->key, key_size);
+
+		if (is_percpu) {
+			int off = 0, cpu;
+			void __percpu *pptr;
+
+			pptr = htab_elem_get_ptr(l, map->key_size);
+			for_each_possible_cpu(cpu) {
+				bpf_long_memcpy(dst_val + off,
+						per_cpu_ptr(pptr, cpu), size);
+				off += size;
+			}
+		} else {
+			value = l->key + roundup_key_size;
+			if (elem_map_flags & BPF_F_LOCK)
+				copy_map_value_locked(map, dst_val, value,
+						      true);
+			else
+				copy_map_value(map, dst_val, value);
+			check_and_init_map_lock(map, dst_val);
+		}
+		if (do_delete) {
+			hlist_nulls_del_rcu(&l->hash_node);
+
+			/* bpf_lru_push_free() will acquire lru_lock, which
+			 * may cause deadlock. See comments in function
+			 * prealloc_lru_pop(). Let us do bpf_lru_push_free()
+			 * after releasing the bucket lock.
+			 */
+			if (is_lru_map) {
+				l->batch_flink = node_to_free;
+				node_to_free = l;
+			} else {
+				free_htab_elem(htab, l);
+			}
+		}
+		dst_key += key_size;
+		dst_val += value_size;
+	}
+
+	htab_unlock_bucket(htab, b, flags);
+	locked = false;
+
+	while (node_to_free) {
+		l = node_to_free;
+		node_to_free = node_to_free->batch_flink;
+		bpf_lru_push_free(&htab->lru, &l->lru_node);
+	}
+
+next_batch:
+	/* If we are not copying data, we can go to next bucket and avoid
+	 * unlocking the rcu.
+	 */
+	if (!bucket_cnt && (batch + 1 < htab->n_buckets)) {
+		batch++;
+		goto again_nocopy;
+	}
+
+	rcu_read_unlock();
+	bpf_enable_instrumentation();
+	if (bucket_cnt && (copy_to_user(ukeys + total * key_size, keys,
+	    key_size * bucket_cnt) ||
+	    copy_to_user(uvalues + total * value_size, values,
+	    value_size * bucket_cnt))) {
+		ret = -EFAULT;
+		goto after_loop;
+	}
+
+	total += bucket_cnt;
+	batch++;
+	if (batch >= htab->n_buckets) {
+		ret = -ENOENT;
+		goto after_loop;
+	}
+	goto again;
+
+after_loop:
+	if (ret == -EFAULT)
+		goto out;
+
+	/* copy # of entries and next batch */
+	ubatch = u64_to_user_ptr(attr->batch.out_batch);
+	if (copy_to_user(ubatch, &batch, sizeof(batch)) ||
+	    put_user(total, &uattr->batch.count))
+		ret = -EFAULT;
+
+out:
+	kvfree(keys);
+	kvfree(values);
+	return ret;
+}
+
+static int
+htab_percpu_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  false, true);
+}
+
+static int
+htab_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
+					const union bpf_attr *attr,
+					union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  false, true);
+}
+
+static int
+htab_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
+		      union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  false, false);
+}
+
+static int
+htab_map_lookup_and_delete_batch(struct bpf_map *map,
+				 const union bpf_attr *attr,
+				 union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  false, false);
+}
+
+static int
+htab_lru_percpu_map_lookup_batch(struct bpf_map *map,
+				 const union bpf_attr *attr,
+				 union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  true, true);
+}
+
+static int
+htab_lru_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
+					    const union bpf_attr *attr,
+					    union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  true, true);
+}
+
+static int
+htab_lru_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
+			  union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  true, false);
+}
+
+static int
+htab_lru_map_lookup_and_delete_batch(struct bpf_map *map,
+				     const union bpf_attr *attr,
+				     union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  true, false);
+}
+
+struct bpf_iter_seq_hash_map_info {
+	struct bpf_map *map;
+	struct bpf_htab *htab;
+	void *percpu_value_buf; // non-zero means percpu hash
+	u32 bucket_id;
+	u32 skip_elems;
+};
+
+static struct htab_elem *
+bpf_hash_map_seq_find_next(struct bpf_iter_seq_hash_map_info *info,
+			   struct htab_elem *prev_elem)
+{
+	const struct bpf_htab *htab = info->htab;
+	u32 skip_elems = info->skip_elems;
+	u32 bucket_id = info->bucket_id;
+	struct hlist_nulls_head *head;
+	struct hlist_nulls_node *n;
+	struct htab_elem *elem;
+	struct bucket *b;
+	u32 i, count;
+
+	if (bucket_id >= htab->n_buckets)
+		return NULL;
+
+	/* try to find next elem in the same bucket */
+	if (prev_elem) {
+		/* no update/deletion on this bucket, prev_elem should be still valid
+		 * and we won't skip elements.
+		 */
+		n = rcu_dereference_raw(hlist_nulls_next_rcu(&prev_elem->hash_node));
+		elem = hlist_nulls_entry_safe(n, struct htab_elem, hash_node);
+		if (elem)
+			return elem;
+
+		/* not found, unlock and go to the next bucket */
+		b = &htab->buckets[bucket_id++];
+		rcu_read_unlock();
+		skip_elems = 0;
+	}
+
+	for (i = bucket_id; i < htab->n_buckets; i++) {
+		b = &htab->buckets[i];
+		rcu_read_lock();
+
+		count = 0;
+		head = &b->head;
+		hlist_nulls_for_each_entry_rcu(elem, n, head, hash_node) {
+			if (count >= skip_elems) {
+				info->bucket_id = i;
+				info->skip_elems = count;
+				return elem;
+			}
+			count++;
+		}
+
+		rcu_read_unlock();
+		skip_elems = 0;
+	}
+
+	info->bucket_id = i;
+	info->skip_elems = 0;
+	return NULL;
+}
+
+static void *bpf_hash_map_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_hash_map_info *info = seq->private;
+	struct htab_elem *elem;
+
+	elem = bpf_hash_map_seq_find_next(info, NULL);
+	if (!elem)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return elem;
+}
+
+static void *bpf_hash_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_hash_map_info *info = seq->private;
+
+	++*pos;
+	++info->skip_elems;
+	return bpf_hash_map_seq_find_next(info, v);
+}
+
+static int __bpf_hash_map_seq_show(struct seq_file *seq, struct htab_elem *elem)
+{
+	struct bpf_iter_seq_hash_map_info *info = seq->private;
+	u32 roundup_key_size, roundup_value_size;
+	struct bpf_iter__bpf_map_elem ctx = {};
+	struct bpf_map *map = info->map;
+	struct bpf_iter_meta meta;
+	int ret = 0, off = 0, cpu;
+	struct bpf_prog *prog;
+	void __percpu *pptr;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, elem == NULL);
+	if (prog) {
+		ctx.meta = &meta;
+		ctx.map = info->map;
+		if (elem) {
+			roundup_key_size = round_up(map->key_size, 8);
+			ctx.key = elem->key;
+			if (!info->percpu_value_buf) {
+				ctx.value = elem->key + roundup_key_size;
+			} else {
+				roundup_value_size = round_up(map->value_size, 8);
+				pptr = htab_elem_get_ptr(elem, map->key_size);
+				for_each_possible_cpu(cpu) {
+					bpf_long_memcpy(info->percpu_value_buf + off,
+							per_cpu_ptr(pptr, cpu),
+							roundup_value_size);
+					off += roundup_value_size;
+				}
+				ctx.value = info->percpu_value_buf;
+			}
+		}
+		ret = bpf_iter_run_prog(prog, &ctx);
+	}
+
+	return ret;
+}
+
+static int bpf_hash_map_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_hash_map_seq_show(seq, v);
+}
+
+static void bpf_hash_map_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_hash_map_seq_show(seq, NULL);
+	else
+		rcu_read_unlock();
+}
+
+static int bpf_iter_init_hash_map(void *priv_data,
+				  struct bpf_iter_aux_info *aux)
+{
+	struct bpf_iter_seq_hash_map_info *seq_info = priv_data;
+	struct bpf_map *map = aux->map;
+	void *value_buf;
+	u32 buf_size;
+
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+		buf_size = round_up(map->value_size, 8) * num_possible_cpus();
+		value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
+		if (!value_buf)
+			return -ENOMEM;
+
+		seq_info->percpu_value_buf = value_buf;
+	}
+
+	seq_info->map = map;
+	seq_info->htab = container_of(map, struct bpf_htab, map);
+	return 0;
+}
+
+static void bpf_iter_fini_hash_map(void *priv_data)
+{
+	struct bpf_iter_seq_hash_map_info *seq_info = priv_data;
+
+	kfree(seq_info->percpu_value_buf);
+}
+
+static const struct seq_operations bpf_hash_map_seq_ops = {
+	.start	= bpf_hash_map_seq_start,
+	.next	= bpf_hash_map_seq_next,
+	.stop	= bpf_hash_map_seq_stop,
+	.show	= bpf_hash_map_seq_show,
+};
+
+static const struct bpf_iter_seq_info iter_seq_info = {
+	.seq_ops		= &bpf_hash_map_seq_ops,
+	.init_seq_private	= bpf_iter_init_hash_map,
+	.fini_seq_private	= bpf_iter_fini_hash_map,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_hash_map_info),
+};
+
+static int htab_map_btf_id;
 const struct bpf_map_ops htab_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
@@ -1266,9 +1839,15 @@
 	.map_delete_elem = htab_map_delete_elem,
 	.map_gen_lookup = htab_map_gen_lookup,
 	.map_seq_show_elem = htab_map_seq_show_elem,
+	BATCH_OPS(htab),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
 };
 
+static int htab_lru_map_btf_id;
 const struct bpf_map_ops htab_lru_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
@@ -1279,6 +1858,10 @@
 	.map_delete_elem = htab_lru_map_delete_elem,
 	.map_gen_lookup = htab_lru_map_gen_lookup,
 	.map_seq_show_elem = htab_map_seq_show_elem,
+	BATCH_OPS(htab_lru),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_lru_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
 };
 
 /* Called from eBPF program */
@@ -1383,7 +1966,9 @@
 	rcu_read_unlock();
 }
 
+static int htab_percpu_map_btf_id;
 const struct bpf_map_ops htab_percpu_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
@@ -1392,9 +1977,15 @@
 	.map_update_elem = htab_percpu_map_update_elem,
 	.map_delete_elem = htab_map_delete_elem,
 	.map_seq_show_elem = htab_percpu_map_seq_show_elem,
+	BATCH_OPS(htab_percpu),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_percpu_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
 };
 
+static int htab_lru_percpu_map_btf_id;
 const struct bpf_map_ops htab_lru_percpu_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
@@ -1403,6 +1994,10 @@
 	.map_update_elem = htab_lru_percpu_map_update_elem,
 	.map_delete_elem = htab_lru_map_delete_elem,
 	.map_seq_show_elem = htab_percpu_map_seq_show_elem,
+	BATCH_OPS(htab_lru_percpu),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_lru_percpu_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
 };
 
 static int fd_htab_map_alloc_check(union bpf_attr *attr)
@@ -1501,7 +2096,7 @@
 	return READ_ONCE(*inner_map);
 }
 
-static u32 htab_of_map_gen_lookup(struct bpf_map *map,
+static int htab_of_map_gen_lookup(struct bpf_map *map,
 				  struct bpf_insn *insn_buf)
 {
 	struct bpf_insn *insn = insn_buf;
@@ -1525,6 +2120,7 @@
 	fd_htab_map_free(map);
 }
 
+static int htab_of_maps_map_btf_id;
 const struct bpf_map_ops htab_of_maps_map_ops = {
 	.map_alloc_check = fd_htab_map_alloc_check,
 	.map_alloc = htab_of_map_alloc,
@@ -1537,4 +2133,6 @@
 	.map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
 	.map_gen_lookup = htab_of_map_gen_lookup,
 	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_of_maps_map_btf_id,
 };
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index a77d281..0efe7c7 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -11,6 +11,10 @@
 #include <linux/uidgid.h>
 #include <linux/filter.h>
 #include <linux/ctype.h>
+#include <linux/jiffies.h>
+#include <linux/pid_namespace.h>
+#include <linux/proc_ns.h>
+#include <linux/security.h>
 
 #include "../../lib/kstrtox.h"
 
@@ -148,7 +152,19 @@
 
 const struct bpf_func_proto bpf_ktime_get_ns_proto = {
 	.func		= bpf_ktime_get_ns,
-	.gpl_only	= true,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_ktime_get_boot_ns)
+{
+	/* NMI safe access to clock boottime */
+	return ktime_get_boot_fast_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
+	.func		= bpf_ktime_get_boot_ns,
+	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
 };
 
@@ -312,12 +328,23 @@
 	preempt_enable();
 }
 
+BPF_CALL_0(bpf_jiffies64)
+{
+	return get_jiffies_64();
+}
+
+const struct bpf_func_proto bpf_jiffies64_proto = {
+	.func		= bpf_jiffies64,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
 #ifdef CONFIG_CGROUPS
 BPF_CALL_0(bpf_get_current_cgroup_id)
 {
 	struct cgroup *cgrp = task_dfl_cgroup(current);
 
-	return cgrp->kn->id.id;
+	return cgroup_id(cgrp);
 }
 
 const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
@@ -326,9 +353,27 @@
 	.ret_type	= RET_INTEGER,
 };
 
+BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)
+{
+	struct cgroup *cgrp = task_dfl_cgroup(current);
+	struct cgroup *ancestor;
+
+	ancestor = cgroup_ancestor(cgrp, ancestor_level);
+	if (!ancestor)
+		return 0;
+	return cgroup_id(ancestor);
+}
+
+const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
+	.func		= bpf_get_current_ancestor_cgroup_id,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+};
+
 #ifdef CONFIG_CGROUP_BPF
-DECLARE_PER_CPU(struct bpf_cgroup_storage*,
-		bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
+DECLARE_PER_CPU(struct bpf_cgroup_storage_info,
+		bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]);
 
 BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
 {
@@ -337,10 +382,17 @@
 	 * verifier checks that its value is correct.
 	 */
 	enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
-	struct bpf_cgroup_storage *storage;
+	struct bpf_cgroup_storage *storage = NULL;
 	void *ptr;
+	int i;
 
-	storage = this_cpu_read(bpf_cgroup_storage[stype]);
+	for (i = BPF_CGROUP_STORAGE_NEST_MAX - 1; i >= 0; i--) {
+		if (likely(this_cpu_read(bpf_cgroup_storage_info[i].task) != current))
+			continue;
+
+		storage = this_cpu_read(bpf_cgroup_storage_info[i].storage[stype]);
+		break;
+	}
 
 	if (stype == BPF_CGROUP_STORAGE_SHARED)
 		ptr = &READ_ONCE(storage->buf)->data[0];
@@ -487,3 +539,213 @@
 	.arg4_type	= ARG_PTR_TO_LONG,
 };
 #endif
+
+BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
+	   struct bpf_pidns_info *, nsdata, u32, size)
+{
+	struct task_struct *task = current;
+	struct pid_namespace *pidns;
+	int err = -EINVAL;
+
+	if (unlikely(size != sizeof(struct bpf_pidns_info)))
+		goto clear;
+
+	if (unlikely((u64)(dev_t)dev != dev))
+		goto clear;
+
+	if (unlikely(!task))
+		goto clear;
+
+	pidns = task_active_pid_ns(task);
+	if (unlikely(!pidns)) {
+		err = -ENOENT;
+		goto clear;
+	}
+
+	if (!ns_match(&pidns->ns, (dev_t)dev, ino))
+		goto clear;
+
+	nsdata->pid = task_pid_nr_ns(task, pidns);
+	nsdata->tgid = task_tgid_nr_ns(task, pidns);
+	return 0;
+clear:
+	memset((void *)nsdata, 0, (size_t) size);
+	return err;
+}
+
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
+	.func		= bpf_get_ns_current_pid_tgid,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type      = ARG_PTR_TO_UNINIT_MEM,
+	.arg4_type      = ARG_CONST_SIZE,
+};
+
+static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
+	.func		= bpf_get_raw_cpu_id,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
+	   u64, flags, void *, data, u64, size)
+{
+	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
+		return -EINVAL;
+
+	return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
+}
+
+const struct bpf_func_proto bpf_event_output_data_proto =  {
+	.func		= bpf_event_output_data,
+	.gpl_only       = true,
+	.ret_type       = RET_INTEGER,
+	.arg1_type      = ARG_PTR_TO_CTX,
+	.arg2_type      = ARG_CONST_MAP_PTR,
+	.arg3_type      = ARG_ANYTHING,
+	.arg4_type      = ARG_PTR_TO_MEM,
+	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
+};
+
+BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
+	   const void __user *, user_ptr)
+{
+	int ret = copy_from_user(dst, user_ptr, size);
+
+	if (unlikely(ret)) {
+		memset(dst, 0, size);
+		ret = -EFAULT;
+	}
+
+	return ret;
+}
+
+const struct bpf_func_proto bpf_copy_from_user_proto = {
+	.func		= bpf_copy_from_user,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
+{
+	if (cpu >= nr_cpu_ids)
+		return (unsigned long)NULL;
+
+	return (unsigned long)per_cpu_ptr((const void __percpu *)ptr, cpu);
+}
+
+const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
+	.func		= bpf_per_cpu_ptr,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL,
+	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
+	.arg2_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
+{
+	return (unsigned long)this_cpu_ptr((const void __percpu *)percpu_ptr);
+}
+
+const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
+	.func		= bpf_this_cpu_ptr,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID,
+	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
+};
+
+const struct bpf_func_proto bpf_get_current_task_proto __weak;
+const struct bpf_func_proto bpf_probe_read_user_proto __weak;
+const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
+const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
+const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
+
+const struct bpf_func_proto *
+bpf_base_func_proto(enum bpf_func_id func_id)
+{
+	switch (func_id) {
+	case BPF_FUNC_map_lookup_elem:
+		return &bpf_map_lookup_elem_proto;
+	case BPF_FUNC_map_update_elem:
+		return &bpf_map_update_elem_proto;
+	case BPF_FUNC_map_delete_elem:
+		return &bpf_map_delete_elem_proto;
+	case BPF_FUNC_map_push_elem:
+		return &bpf_map_push_elem_proto;
+	case BPF_FUNC_map_pop_elem:
+		return &bpf_map_pop_elem_proto;
+	case BPF_FUNC_map_peek_elem:
+		return &bpf_map_peek_elem_proto;
+	case BPF_FUNC_get_prandom_u32:
+		return &bpf_get_prandom_u32_proto;
+	case BPF_FUNC_get_smp_processor_id:
+		return &bpf_get_raw_smp_processor_id_proto;
+	case BPF_FUNC_get_numa_node_id:
+		return &bpf_get_numa_node_id_proto;
+	case BPF_FUNC_tail_call:
+		return &bpf_tail_call_proto;
+	case BPF_FUNC_ktime_get_ns:
+		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_boot_ns:
+		return &bpf_ktime_get_boot_ns_proto;
+	case BPF_FUNC_ringbuf_output:
+		return &bpf_ringbuf_output_proto;
+	case BPF_FUNC_ringbuf_reserve:
+		return &bpf_ringbuf_reserve_proto;
+	case BPF_FUNC_ringbuf_submit:
+		return &bpf_ringbuf_submit_proto;
+	case BPF_FUNC_ringbuf_discard:
+		return &bpf_ringbuf_discard_proto;
+	case BPF_FUNC_ringbuf_query:
+		return &bpf_ringbuf_query_proto;
+	default:
+		break;
+	}
+
+	if (!bpf_capable())
+		return NULL;
+
+	switch (func_id) {
+	case BPF_FUNC_spin_lock:
+		return &bpf_spin_lock_proto;
+	case BPF_FUNC_spin_unlock:
+		return &bpf_spin_unlock_proto;
+	case BPF_FUNC_jiffies64:
+		return &bpf_jiffies64_proto;
+	case BPF_FUNC_per_cpu_ptr:
+		return &bpf_per_cpu_ptr_proto;
+	case BPF_FUNC_this_cpu_ptr:
+		return &bpf_this_cpu_ptr_proto;
+	default:
+		break;
+	}
+
+	if (!perfmon_capable())
+		return NULL;
+
+	switch (func_id) {
+	case BPF_FUNC_trace_printk:
+		return bpf_get_trace_printk_proto();
+	case BPF_FUNC_get_current_task:
+		return &bpf_get_current_task_proto;
+	case BPF_FUNC_probe_read_user:
+		return &bpf_probe_read_user_proto;
+	case BPF_FUNC_probe_read_kernel:
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_kernel_proto;
+	case BPF_FUNC_probe_read_user_str:
+		return &bpf_probe_read_user_str_proto;
+	case BPF_FUNC_probe_read_kernel_str:
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_kernel_str_proto;
+	case BPF_FUNC_snprintf_btf:
+		return &bpf_snprintf_btf_proto;
+	default:
+		return NULL;
+	}
+}
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 375d93e..6b14b4c 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -20,21 +20,26 @@
 #include <linux/filter.h>
 #include <linux/bpf.h>
 #include <linux/bpf_trace.h>
+#include "preload/bpf_preload.h"
 
 enum bpf_type {
 	BPF_TYPE_UNSPEC	= 0,
 	BPF_TYPE_PROG,
 	BPF_TYPE_MAP,
+	BPF_TYPE_LINK,
 };
 
 static void *bpf_any_get(void *raw, enum bpf_type type)
 {
 	switch (type) {
 	case BPF_TYPE_PROG:
-		raw = bpf_prog_inc(raw);
+		bpf_prog_inc(raw);
 		break;
 	case BPF_TYPE_MAP:
-		raw = bpf_map_inc(raw, true);
+		bpf_map_inc_with_uref(raw);
+		break;
+	case BPF_TYPE_LINK:
+		bpf_link_inc(raw);
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -53,6 +58,9 @@
 	case BPF_TYPE_MAP:
 		bpf_map_put_with_uref(raw);
 		break;
+	case BPF_TYPE_LINK:
+		bpf_link_put(raw);
+		break;
 	default:
 		WARN_ON_ONCE(1);
 		break;
@@ -63,20 +71,32 @@
 {
 	void *raw;
 
-	*type = BPF_TYPE_MAP;
 	raw = bpf_map_get_with_uref(ufd);
-	if (IS_ERR(raw)) {
-		*type = BPF_TYPE_PROG;
-		raw = bpf_prog_get(ufd);
+	if (!IS_ERR(raw)) {
+		*type = BPF_TYPE_MAP;
+		return raw;
 	}
 
-	return raw;
+	raw = bpf_prog_get(ufd);
+	if (!IS_ERR(raw)) {
+		*type = BPF_TYPE_PROG;
+		return raw;
+	}
+
+	raw = bpf_link_get_from_fd(ufd);
+	if (!IS_ERR(raw)) {
+		*type = BPF_TYPE_LINK;
+		return raw;
+	}
+
+	return ERR_PTR(-EINVAL);
 }
 
 static const struct inode_operations bpf_dir_iops;
 
 static const struct inode_operations bpf_prog_iops = { };
 static const struct inode_operations bpf_map_iops  = { };
+static const struct inode_operations bpf_link_iops  = { };
 
 static struct inode *bpf_get_inode(struct super_block *sb,
 				   const struct inode *dir,
@@ -114,6 +134,8 @@
 		*type = BPF_TYPE_PROG;
 	else if (inode->i_op == &bpf_map_iops)
 		*type = BPF_TYPE_MAP;
+	else if (inode->i_op == &bpf_link_iops)
+		*type = BPF_TYPE_LINK;
 	else
 		return -EACCES;
 
@@ -337,13 +359,23 @@
 			     &bpffs_map_fops : &bpffs_obj_fops);
 }
 
+static int bpf_mklink(struct dentry *dentry, umode_t mode, void *arg)
+{
+	struct bpf_link *link = arg;
+
+	return bpf_mkobj_ops(dentry, mode, arg, &bpf_link_iops,
+			     bpf_link_is_iter(link) ?
+			     &bpf_iter_fops : &bpffs_obj_fops);
+}
+
 static struct dentry *
 bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
 {
 	/* Dots in names (e.g. "/sys/fs/bpf/foo.bar") are reserved for future
-	 * extensions.
+	 * extensions. That allows popoulate_bpffs() create special files.
 	 */
-	if (strchr(dentry->d_name.name, '.'))
+	if ((dir->i_mode & S_IALLUGO) &&
+	    strchr(dentry->d_name.name, '.'))
 		return ERR_PTR(-EPERM);
 
 	return simple_lookup(dir, dentry, flags);
@@ -381,7 +413,28 @@
 	.unlink		= simple_unlink,
 };
 
-static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
+/* pin iterator link into bpffs */
+static int bpf_iter_link_pin_kernel(struct dentry *parent,
+				    const char *name, struct bpf_link *link)
+{
+	umode_t mode = S_IFREG | S_IRUSR;
+	struct dentry *dentry;
+	int ret;
+
+	inode_lock(parent->d_inode);
+	dentry = lookup_one_len(name, parent, strlen(name));
+	if (IS_ERR(dentry)) {
+		inode_unlock(parent->d_inode);
+		return PTR_ERR(dentry);
+	}
+	ret = bpf_mkobj_ops(dentry, mode, link, &bpf_link_iops,
+			    &bpf_iter_fops);
+	dput(dentry);
+	inode_unlock(parent->d_inode);
+	return ret;
+}
+
+static int bpf_obj_do_pin(const char __user *pathname, void *raw,
 			  enum bpf_type type)
 {
 	struct dentry *dentry;
@@ -390,7 +443,7 @@
 	umode_t mode;
 	int ret;
 
-	dentry = kern_path_create(AT_FDCWD, pathname->name, &path, 0);
+	dentry = user_path_create(AT_FDCWD, pathname, &path, 0);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
@@ -413,6 +466,9 @@
 	case BPF_TYPE_MAP:
 		ret = vfs_mkobj(dentry, mode, bpf_mkmap, raw);
 		break;
+	case BPF_TYPE_LINK:
+		ret = vfs_mkobj(dentry, mode, bpf_mklink, raw);
+		break;
 	default:
 		ret = -EPERM;
 	}
@@ -423,30 +479,22 @@
 
 int bpf_obj_pin_user(u32 ufd, const char __user *pathname)
 {
-	struct filename *pname;
 	enum bpf_type type;
 	void *raw;
 	int ret;
 
-	pname = getname(pathname);
-	if (IS_ERR(pname))
-		return PTR_ERR(pname);
-
 	raw = bpf_fd_probe_obj(ufd, &type);
-	if (IS_ERR(raw)) {
-		ret = PTR_ERR(raw);
-		goto out;
-	}
+	if (IS_ERR(raw))
+		return PTR_ERR(raw);
 
-	ret = bpf_obj_do_pin(pname, raw, type);
+	ret = bpf_obj_do_pin(pathname, raw, type);
 	if (ret != 0)
 		bpf_any_put(raw, type);
-out:
-	putname(pname);
+
 	return ret;
 }
 
-static void *bpf_obj_do_get(const struct filename *pathname,
+static void *bpf_obj_do_get(const char __user *pathname,
 			    enum bpf_type *type, int flags)
 {
 	struct inode *inode;
@@ -454,7 +502,7 @@
 	void *raw;
 	int ret;
 
-	ret = kern_path(pathname->name, LOOKUP_FOLLOW, &path);
+	ret = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW, &path);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -481,36 +529,29 @@
 int bpf_obj_get_user(const char __user *pathname, int flags)
 {
 	enum bpf_type type = BPF_TYPE_UNSPEC;
-	struct filename *pname;
-	int ret = -ENOENT;
 	int f_flags;
 	void *raw;
+	int ret;
 
 	f_flags = bpf_get_file_flag(flags);
 	if (f_flags < 0)
 		return f_flags;
 
-	pname = getname(pathname);
-	if (IS_ERR(pname))
-		return PTR_ERR(pname);
-
-	raw = bpf_obj_do_get(pname, &type, f_flags);
-	if (IS_ERR(raw)) {
-		ret = PTR_ERR(raw);
-		goto out;
-	}
+	raw = bpf_obj_do_get(pathname, &type, f_flags);
+	if (IS_ERR(raw))
+		return PTR_ERR(raw);
 
 	if (type == BPF_TYPE_PROG)
 		ret = bpf_prog_new_fd(raw);
 	else if (type == BPF_TYPE_MAP)
 		ret = bpf_map_new_fd(raw, f_flags);
+	else if (type == BPF_TYPE_LINK)
+		ret = (f_flags != O_RDWR) ? -EINVAL : bpf_link_new_fd(raw);
 	else
-		goto out;
+		return -ENOENT;
 
 	if (ret < 0)
 		bpf_any_put(raw, type);
-out:
-	putname(pname);
 	return ret;
 }
 
@@ -523,6 +564,8 @@
 
 	if (inode->i_op == &bpf_map_iops)
 		return ERR_PTR(-EINVAL);
+	if (inode->i_op == &bpf_link_iops)
+		return ERR_PTR(-EINVAL);
 	if (inode->i_op != &bpf_prog_iops)
 		return ERR_PTR(-EACCES);
 
@@ -535,7 +578,8 @@
 	if (!bpf_prog_get_ok(prog, &type, false))
 		return ERR_PTR(-EINVAL);
 
-	return bpf_prog_inc(prog);
+	bpf_prog_inc(prog);
+	return prog;
 }
 
 struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type)
@@ -587,16 +631,11 @@
 	OPT_MODE,
 };
 
-static const struct fs_parameter_spec bpf_param_specs[] = {
+static const struct fs_parameter_spec bpf_fs_parameters[] = {
 	fsparam_u32oct	("mode",			OPT_MODE),
 	{}
 };
 
-static const struct fs_parameter_description bpf_fs_parameters = {
-	.name		= "bpf",
-	.specs		= bpf_param_specs,
-};
-
 struct bpf_mount_opts {
 	umode_t mode;
 };
@@ -607,7 +646,7 @@
 	struct fs_parse_result result;
 	int opt;
 
-	opt = fs_parse(fc, &bpf_fs_parameters, param, &result);
+	opt = fs_parse(fc, bpf_fs_parameters, param, &result);
 	if (opt < 0)
 		/* We might like to report bad mount options here, but
 		 * traditionally we've ignored all mount options, so we'd
@@ -624,6 +663,91 @@
 	return 0;
 }
 
+struct bpf_preload_ops *bpf_preload_ops;
+EXPORT_SYMBOL_GPL(bpf_preload_ops);
+
+static bool bpf_preload_mod_get(void)
+{
+	/* If bpf_preload.ko wasn't loaded earlier then load it now.
+	 * When bpf_preload is built into vmlinux the module's __init
+	 * function will populate it.
+	 */
+	if (!bpf_preload_ops) {
+		request_module("bpf_preload");
+		if (!bpf_preload_ops)
+			return false;
+	}
+	/* And grab the reference, so the module doesn't disappear while the
+	 * kernel is interacting with the kernel module and its UMD.
+	 */
+	if (!try_module_get(bpf_preload_ops->owner)) {
+		pr_err("bpf_preload module get failed.\n");
+		return false;
+	}
+	return true;
+}
+
+static void bpf_preload_mod_put(void)
+{
+	if (bpf_preload_ops)
+		/* now user can "rmmod bpf_preload" if necessary */
+		module_put(bpf_preload_ops->owner);
+}
+
+static DEFINE_MUTEX(bpf_preload_lock);
+
+static int populate_bpffs(struct dentry *parent)
+{
+	struct bpf_preload_info objs[BPF_PRELOAD_LINKS] = {};
+	struct bpf_link *links[BPF_PRELOAD_LINKS] = {};
+	int err = 0, i;
+
+	/* grab the mutex to make sure the kernel interactions with bpf_preload
+	 * UMD are serialized
+	 */
+	mutex_lock(&bpf_preload_lock);
+
+	/* if bpf_preload.ko wasn't built into vmlinux then load it */
+	if (!bpf_preload_mod_get())
+		goto out;
+
+	if (!bpf_preload_ops->info.tgid) {
+		/* preload() will start UMD that will load BPF iterator programs */
+		err = bpf_preload_ops->preload(objs);
+		if (err)
+			goto out_put;
+		for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+			links[i] = bpf_link_by_id(objs[i].link_id);
+			if (IS_ERR(links[i])) {
+				err = PTR_ERR(links[i]);
+				goto out_put;
+			}
+		}
+		for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+			err = bpf_iter_link_pin_kernel(parent,
+						       objs[i].link_name, links[i]);
+			if (err)
+				goto out_put;
+			/* do not unlink successfully pinned links even
+			 * if later link fails to pin
+			 */
+			links[i] = NULL;
+		}
+		/* finish() will tell UMD process to exit */
+		err = bpf_preload_ops->finish();
+		if (err)
+			goto out_put;
+	}
+out_put:
+	bpf_preload_mod_put();
+out:
+	mutex_unlock(&bpf_preload_lock);
+	for (i = 0; i < BPF_PRELOAD_LINKS && err; i++)
+		if (!IS_ERR_OR_NULL(links[i]))
+			bpf_link_put(links[i]);
+	return err;
+}
+
 static int bpf_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	static const struct tree_descr bpf_rfiles[] = { { "" } };
@@ -640,8 +764,8 @@
 	inode = sb->s_root->d_inode;
 	inode->i_op = &bpf_dir_iops;
 	inode->i_mode &= ~S_IALLUGO;
+	populate_bpffs(sb->s_root);
 	inode->i_mode |= S_ISVTX | opts->mode;
-
 	return 0;
 }
 
@@ -683,7 +807,7 @@
 	.owner		= THIS_MODULE,
 	.name		= "bpf",
 	.init_fs_context = bpf_init_fs_context,
-	.parameters	= &bpf_fs_parameters,
+	.parameters	= bpf_fs_parameters,
 	.kill_sb	= kill_litter_super,
 };
 
@@ -691,6 +815,8 @@
 {
 	int ret;
 
+	mutex_init(&bpf_preload_lock);
+
 	ret = sysfs_create_mount_point(fs_kobj, "bpf");
 	if (ret)
 		return ret;
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index addd6fd..b139247 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -9,10 +9,13 @@
 #include <linux/slab.h>
 #include <uapi/linux/btf.h>
 
-DEFINE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
-
 #ifdef CONFIG_CGROUP_BPF
 
+DEFINE_PER_CPU(struct bpf_cgroup_storage_info,
+	       bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]);
+
+#include "../cgroup/cgroup-internal.h"
+
 #define LOCAL_STORAGE_CREATE_FLAG_MASK					\
 	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
@@ -20,7 +23,6 @@
 	struct bpf_map map;
 
 	spinlock_t lock;
-	struct bpf_prog *prog;
 	struct rb_root root;
 	struct list_head list;
 };
@@ -30,24 +32,41 @@
 	return container_of(map, struct bpf_cgroup_storage_map, map);
 }
 
-static int bpf_cgroup_storage_key_cmp(
-	const struct bpf_cgroup_storage_key *key1,
-	const struct bpf_cgroup_storage_key *key2)
+static bool attach_type_isolated(const struct bpf_map *map)
 {
-	if (key1->cgroup_inode_id < key2->cgroup_inode_id)
-		return -1;
-	else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
-		return 1;
-	else if (key1->attach_type < key2->attach_type)
-		return -1;
-	else if (key1->attach_type > key2->attach_type)
-		return 1;
+	return map->key_size == sizeof(struct bpf_cgroup_storage_key);
+}
+
+static int bpf_cgroup_storage_key_cmp(const struct bpf_cgroup_storage_map *map,
+				      const void *_key1, const void *_key2)
+{
+	if (attach_type_isolated(&map->map)) {
+		const struct bpf_cgroup_storage_key *key1 = _key1;
+		const struct bpf_cgroup_storage_key *key2 = _key2;
+
+		if (key1->cgroup_inode_id < key2->cgroup_inode_id)
+			return -1;
+		else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
+			return 1;
+		else if (key1->attach_type < key2->attach_type)
+			return -1;
+		else if (key1->attach_type > key2->attach_type)
+			return 1;
+	} else {
+		const __u64 *cgroup_inode_id1 = _key1;
+		const __u64 *cgroup_inode_id2 = _key2;
+
+		if (*cgroup_inode_id1 < *cgroup_inode_id2)
+			return -1;
+		else if (*cgroup_inode_id1 > *cgroup_inode_id2)
+			return 1;
+	}
 	return 0;
 }
 
-static struct bpf_cgroup_storage *cgroup_storage_lookup(
-	struct bpf_cgroup_storage_map *map, struct bpf_cgroup_storage_key *key,
-	bool locked)
+struct bpf_cgroup_storage *
+cgroup_storage_lookup(struct bpf_cgroup_storage_map *map,
+		      void *key, bool locked)
 {
 	struct rb_root *root = &map->root;
 	struct rb_node *node;
@@ -61,7 +80,7 @@
 
 		storage = container_of(node, struct bpf_cgroup_storage, node);
 
-		switch (bpf_cgroup_storage_key_cmp(key, &storage->key)) {
+		switch (bpf_cgroup_storage_key_cmp(map, key, &storage->key)) {
 		case -1:
 			node = node->rb_left;
 			break;
@@ -93,7 +112,7 @@
 		this = container_of(*new, struct bpf_cgroup_storage, node);
 
 		parent = *new;
-		switch (bpf_cgroup_storage_key_cmp(&storage->key, &this->key)) {
+		switch (bpf_cgroup_storage_key_cmp(map, &storage->key, &this->key)) {
 		case -1:
 			new = &((*new)->rb_left);
 			break;
@@ -111,10 +130,9 @@
 	return 0;
 }
 
-static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *_key)
+static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *key)
 {
 	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
-	struct bpf_cgroup_storage_key *key = _key;
 	struct bpf_cgroup_storage *storage;
 
 	storage = cgroup_storage_lookup(map, key, false);
@@ -124,17 +142,13 @@
 	return &READ_ONCE(storage->buf)->data[0];
 }
 
-static int cgroup_storage_update_elem(struct bpf_map *map, void *_key,
+static int cgroup_storage_update_elem(struct bpf_map *map, void *key,
 				      void *value, u64 flags)
 {
-	struct bpf_cgroup_storage_key *key = _key;
 	struct bpf_cgroup_storage *storage;
 	struct bpf_storage_buffer *new;
 
-	if (unlikely(flags & ~(BPF_F_LOCK | BPF_EXIST | BPF_NOEXIST)))
-		return -EINVAL;
-
-	if (unlikely(flags & BPF_NOEXIST))
+	if (unlikely(flags & ~(BPF_F_LOCK | BPF_EXIST)))
 		return -EINVAL;
 
 	if (unlikely((flags & BPF_F_LOCK) &&
@@ -167,11 +181,10 @@
 	return 0;
 }
 
-int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *_key,
+int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key,
 				   void *value)
 {
 	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
-	struct bpf_cgroup_storage_key *key = _key;
 	struct bpf_cgroup_storage *storage;
 	int cpu, off = 0;
 	u32 size;
@@ -197,11 +210,10 @@
 	return 0;
 }
 
-int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *_key,
+int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *key,
 				     void *value, u64 map_flags)
 {
 	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
-	struct bpf_cgroup_storage_key *key = _key;
 	struct bpf_cgroup_storage *storage;
 	int cpu, off = 0;
 	u32 size;
@@ -232,12 +244,10 @@
 	return 0;
 }
 
-static int cgroup_storage_get_next_key(struct bpf_map *_map, void *_key,
+static int cgroup_storage_get_next_key(struct bpf_map *_map, void *key,
 				       void *_next_key)
 {
 	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
-	struct bpf_cgroup_storage_key *key = _key;
-	struct bpf_cgroup_storage_key *next = _next_key;
 	struct bpf_cgroup_storage *storage;
 
 	spin_lock_bh(&map->lock);
@@ -250,17 +260,23 @@
 		if (!storage)
 			goto enoent;
 
-		storage = list_next_entry(storage, list);
+		storage = list_next_entry(storage, list_map);
 		if (!storage)
 			goto enoent;
 	} else {
 		storage = list_first_entry(&map->list,
-					 struct bpf_cgroup_storage, list);
+					 struct bpf_cgroup_storage, list_map);
 	}
 
 	spin_unlock_bh(&map->lock);
-	next->attach_type = storage->key.attach_type;
-	next->cgroup_inode_id = storage->key.cgroup_inode_id;
+
+	if (attach_type_isolated(&map->map)) {
+		struct bpf_cgroup_storage_key *next = _next_key;
+		*next = storage->key;
+	} else {
+		__u64 *next = _next_key;
+		*next = storage->key.cgroup_inode_id;
+	}
 	return 0;
 
 enoent:
@@ -275,7 +291,8 @@
 	struct bpf_map_memory mem;
 	int ret;
 
-	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
+	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
+	    attr->key_size != sizeof(__u64))
 		return ERR_PTR(-EINVAL);
 
 	if (attr->value_size == 0)
@@ -318,6 +335,17 @@
 static void cgroup_storage_map_free(struct bpf_map *_map)
 {
 	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
+	struct list_head *storages = &map->list;
+	struct bpf_cgroup_storage *storage, *stmp;
+
+	mutex_lock(&cgroup_mutex);
+
+	list_for_each_entry_safe(storage, stmp, storages, list_map) {
+		bpf_cgroup_storage_unlink(storage);
+		bpf_cgroup_storage_free(storage);
+	}
+
+	mutex_unlock(&cgroup_mutex);
 
 	WARN_ON(!RB_EMPTY_ROOT(&map->root));
 	WARN_ON(!list_empty(&map->list));
@@ -335,49 +363,63 @@
 				    const struct btf_type *key_type,
 				    const struct btf_type *value_type)
 {
-	struct btf_member *m;
-	u32 offset, size;
+	if (attach_type_isolated(map)) {
+		struct btf_member *m;
+		u32 offset, size;
 
-	/* Key is expected to be of struct bpf_cgroup_storage_key type,
-	 * which is:
-	 * struct bpf_cgroup_storage_key {
-	 *	__u64	cgroup_inode_id;
-	 *	__u32	attach_type;
-	 * };
-	 */
+		/* Key is expected to be of struct bpf_cgroup_storage_key type,
+		 * which is:
+		 * struct bpf_cgroup_storage_key {
+		 *	__u64	cgroup_inode_id;
+		 *	__u32	attach_type;
+		 * };
+		 */
 
-	/*
-	 * Key_type must be a structure with two fields.
-	 */
-	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ||
-	    BTF_INFO_VLEN(key_type->info) != 2)
-		return -EINVAL;
+		/*
+		 * Key_type must be a structure with two fields.
+		 */
+		if (BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ||
+		    BTF_INFO_VLEN(key_type->info) != 2)
+			return -EINVAL;
 
-	/*
-	 * The first field must be a 64 bit integer at 0 offset.
-	 */
-	m = (struct btf_member *)(key_type + 1);
-	size = FIELD_SIZEOF(struct bpf_cgroup_storage_key, cgroup_inode_id);
-	if (!btf_member_is_reg_int(btf, key_type, m, 0, size))
-		return -EINVAL;
+		/*
+		 * The first field must be a 64 bit integer at 0 offset.
+		 */
+		m = (struct btf_member *)(key_type + 1);
+		size = sizeof_field(struct bpf_cgroup_storage_key, cgroup_inode_id);
+		if (!btf_member_is_reg_int(btf, key_type, m, 0, size))
+			return -EINVAL;
 
-	/*
-	 * The second field must be a 32 bit integer at 64 bit offset.
-	 */
-	m++;
-	offset = offsetof(struct bpf_cgroup_storage_key, attach_type);
-	size = FIELD_SIZEOF(struct bpf_cgroup_storage_key, attach_type);
-	if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
-		return -EINVAL;
+		/*
+		 * The second field must be a 32 bit integer at 64 bit offset.
+		 */
+		m++;
+		offset = offsetof(struct bpf_cgroup_storage_key, attach_type);
+		size = sizeof_field(struct bpf_cgroup_storage_key, attach_type);
+		if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
+			return -EINVAL;
+	} else {
+		u32 int_data;
+
+		/*
+		 * Key is expected to be u64, which stores the cgroup_inode_id
+		 */
+
+		if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
+			return -EINVAL;
+
+		int_data = *(u32 *)(key_type + 1);
+		if (BTF_INT_BITS(int_data) != 64 || BTF_INT_OFFSET(int_data))
+			return -EINVAL;
+	}
 
 	return 0;
 }
 
-static void cgroup_storage_seq_show_elem(struct bpf_map *map, void *_key,
+static void cgroup_storage_seq_show_elem(struct bpf_map *map, void *key,
 					 struct seq_file *m)
 {
 	enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
-	struct bpf_cgroup_storage_key *key = _key;
 	struct bpf_cgroup_storage *storage;
 	int cpu;
 
@@ -409,6 +451,7 @@
 	rcu_read_unlock();
 }
 
+static int cgroup_storage_map_btf_id;
 const struct bpf_map_ops cgroup_storage_map_ops = {
 	.map_alloc = cgroup_storage_map_alloc,
 	.map_free = cgroup_storage_map_free,
@@ -418,43 +461,20 @@
 	.map_delete_elem = cgroup_storage_delete_elem,
 	.map_check_btf = cgroup_storage_check_btf,
 	.map_seq_show_elem = cgroup_storage_seq_show_elem,
+	.map_btf_name = "bpf_cgroup_storage_map",
+	.map_btf_id = &cgroup_storage_map_btf_id,
 };
 
-int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *_map)
+int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux, struct bpf_map *_map)
 {
 	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
-	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
-	int ret = -EBUSY;
 
-	spin_lock_bh(&map->lock);
+	if (aux->cgroup_storage[stype] &&
+	    aux->cgroup_storage[stype] != _map)
+		return -EBUSY;
 
-	if (map->prog && map->prog != prog)
-		goto unlock;
-	if (prog->aux->cgroup_storage[stype] &&
-	    prog->aux->cgroup_storage[stype] != _map)
-		goto unlock;
-
-	map->prog = prog;
-	prog->aux->cgroup_storage[stype] = _map;
-	ret = 0;
-unlock:
-	spin_unlock_bh(&map->lock);
-
-	return ret;
-}
-
-void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *_map)
-{
-	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
-	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
-
-	spin_lock_bh(&map->lock);
-	if (map->prog == prog) {
-		WARN_ON(prog->aux->cgroup_storage[stype] != _map);
-		map->prog = NULL;
-		prog->aux->cgroup_storage[stype] = NULL;
-	}
-	spin_unlock_bh(&map->lock);
+	aux->cgroup_storage[stype] = _map;
+	return 0;
 }
 
 static size_t bpf_cgroup_storage_calculate_size(struct bpf_map *map, u32 *pages)
@@ -569,13 +589,14 @@
 		return;
 
 	storage->key.attach_type = type;
-	storage->key.cgroup_inode_id = cgroup->kn->id.id;
+	storage->key.cgroup_inode_id = cgroup_id(cgroup);
 
 	map = storage->map;
 
 	spin_lock_bh(&map->lock);
 	WARN_ON(cgroup_storage_insert(map, storage));
-	list_add(&storage->list, &map->list);
+	list_add(&storage->list_map, &map->list);
+	list_add(&storage->list_cg, &cgroup->bpf.storages);
 	spin_unlock_bh(&map->lock);
 }
 
@@ -593,7 +614,8 @@
 	root = &map->root;
 	rb_erase(&storage->node, root);
 
-	list_del(&storage->list);
+	list_del(&storage->list_map);
+	list_del(&storage->list_cg);
 	spin_unlock_bh(&map->lock);
 }
 
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index 56e6c75..00e32f2 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -25,7 +25,7 @@
 	struct lpm_trie_node __rcu	*child[2];
 	u32				prefixlen;
 	u32				flags;
-	u8				data[0];
+	u8				data[];
 };
 
 struct lpm_trie {
@@ -34,7 +34,7 @@
 	size_t				n_entries;
 	size_t				max_prefixlen;
 	size_t				data_size;
-	raw_spinlock_t			lock;
+	spinlock_t			lock;
 };
 
 /* This trie implements a longest prefix match algorithm that can be used to
@@ -315,7 +315,7 @@
 	if (key->prefixlen > trie->max_prefixlen)
 		return -EINVAL;
 
-	raw_spin_lock_irqsave(&trie->lock, irq_flags);
+	spin_lock_irqsave(&trie->lock, irq_flags);
 
 	/* Allocate and fill a new node */
 
@@ -422,7 +422,7 @@
 		kfree(im_node);
 	}
 
-	raw_spin_unlock_irqrestore(&trie->lock, irq_flags);
+	spin_unlock_irqrestore(&trie->lock, irq_flags);
 
 	return ret;
 }
@@ -442,7 +442,7 @@
 	if (key->prefixlen > trie->max_prefixlen)
 		return -EINVAL;
 
-	raw_spin_lock_irqsave(&trie->lock, irq_flags);
+	spin_lock_irqsave(&trie->lock, irq_flags);
 
 	/* Walk the tree looking for an exact key/length match and keeping
 	 * track of the path we traverse.  We will need to know the node
@@ -518,7 +518,7 @@
 	kfree_rcu(node, rcu);
 
 out:
-	raw_spin_unlock_irqrestore(&trie->lock, irq_flags);
+	spin_unlock_irqrestore(&trie->lock, irq_flags);
 
 	return ret;
 }
@@ -543,7 +543,7 @@
 	u64 cost = sizeof(*trie), cost_per_node;
 	int ret;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!bpf_capable())
 		return ERR_PTR(-EPERM);
 
 	/* check sanity of attributes */
@@ -575,7 +575,7 @@
 	if (ret)
 		goto out_err;
 
-	raw_spin_lock_init(&trie->lock);
+	spin_lock_init(&trie->lock);
 
 	return &trie->map;
 out_err:
@@ -589,11 +589,6 @@
 	struct lpm_trie_node __rcu **slot;
 	struct lpm_trie_node *node;
 
-	/* Wait for outstanding programs to complete
-	 * update/lookup/delete/get_next_key and free the trie.
-	 */
-	synchronize_rcu();
-
 	/* Always start at the root and walk down to a node that has no
 	 * children. Then free that node, nullify its reference in the parent
 	 * and start over.
@@ -735,7 +730,9 @@
 	       -EINVAL : 0;
 }
 
+static int trie_map_btf_id;
 const struct bpf_map_ops trie_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc = trie_alloc,
 	.map_free = trie_free,
 	.map_get_next_key = trie_get_next_key,
@@ -743,4 +740,6 @@
 	.map_update_elem = trie_update_elem,
 	.map_delete_elem = trie_delete_elem,
 	.map_check_btf = trie_check_btf,
+	.map_btf_name = "lpm_trie",
+	.map_btf_id = &trie_map_btf_id,
 };
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
index fab4fb1..39ab0b6 100644
--- a/kernel/bpf/map_in_map.c
+++ b/kernel/bpf/map_in_map.c
@@ -17,23 +17,17 @@
 	if (IS_ERR(inner_map))
 		return inner_map;
 
-	/* prog_array->owner_prog_type and owner_jited
-	 * is a runtime binding.  Doing static check alone
-	 * in the verifier is not enough.
-	 */
-	if (inner_map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
-	    inner_map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE ||
-	    inner_map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
-		fdput(f);
-		return ERR_PTR(-ENOTSUPP);
-	}
-
 	/* Does not support >1 level map-in-map */
 	if (inner_map->inner_map_meta) {
 		fdput(f);
 		return ERR_PTR(-EINVAL);
 	}
 
+	if (!inner_map->ops->map_meta_equal) {
+		fdput(f);
+		return ERR_PTR(-ENOTSUPP);
+	}
+
 	if (map_value_has_spin_lock(inner_map)) {
 		fdput(f);
 		return ERR_PTR(-ENOTSUPP);
@@ -60,7 +54,7 @@
 	/* Misc members not needed in bpf_map_meta_equal() check. */
 	inner_map_meta->ops = inner_map->ops;
 	if (inner_map->ops == &array_map_ops) {
-		inner_map_meta->unpriv_array = inner_map->unpriv_array;
+		inner_map_meta->bypass_spec_v1 = inner_map->bypass_spec_v1;
 		container_of(inner_map_meta, struct bpf_array, map)->index_mask =
 		     container_of(inner_map, struct bpf_array, map)->index_mask;
 	}
@@ -81,15 +75,14 @@
 	return meta0->map_type == meta1->map_type &&
 		meta0->key_size == meta1->key_size &&
 		meta0->value_size == meta1->value_size &&
-		meta0->map_flags == meta1->map_flags &&
-		meta0->max_entries == meta1->max_entries;
+		meta0->map_flags == meta1->map_flags;
 }
 
 void *bpf_map_fd_get_ptr(struct bpf_map *map,
 			 struct file *map_file /* not used */,
 			 int ufd)
 {
-	struct bpf_map *inner_map;
+	struct bpf_map *inner_map, *inner_map_meta;
 	struct fd f;
 
 	f = fdget(ufd);
@@ -97,8 +90,9 @@
 	if (IS_ERR(inner_map))
 		return inner_map;
 
-	if (bpf_map_meta_equal(map->inner_map_meta, inner_map))
-		inner_map = bpf_map_inc(inner_map, false);
+	inner_map_meta = map->inner_map_meta;
+	if (inner_map_meta->ops->map_meta_equal(inner_map_meta, inner_map))
+		bpf_map_inc(inner_map);
 	else
 		inner_map = ERR_PTR(-EINVAL);
 
diff --git a/kernel/bpf/map_in_map.h b/kernel/bpf/map_in_map.h
index a507bf6..bcb7534 100644
--- a/kernel/bpf/map_in_map.h
+++ b/kernel/bpf/map_in_map.h
@@ -11,8 +11,6 @@
 
 struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd);
 void bpf_map_meta_free(struct bpf_map *map_meta);
-bool bpf_map_meta_equal(const struct bpf_map *meta0,
-			const struct bpf_map *meta1);
 void *bpf_map_fd_get_ptr(struct bpf_map *map, struct file *map_file,
 			 int ufd);
 void bpf_map_fd_put_ptr(void *ptr);
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
new file mode 100644
index 0000000..6a9542a
--- /dev/null
+++ b/kernel/bpf/map_iter.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+#include <linux/bpf.h>
+#include <linux/fs.h>
+#include <linux/filter.h>
+#include <linux/kernel.h>
+#include <linux/btf_ids.h>
+
+struct bpf_iter_seq_map_info {
+	u32 map_id;
+};
+
+static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_map_info *info = seq->private;
+	struct bpf_map *map;
+
+	map = bpf_map_get_curr_or_next(&info->map_id);
+	if (!map)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return map;
+}
+
+static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_map_info *info = seq->private;
+
+	++*pos;
+	++info->map_id;
+	bpf_map_put((struct bpf_map *)v);
+	return bpf_map_get_curr_or_next(&info->map_id);
+}
+
+struct bpf_iter__bpf_map {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct bpf_map *, map);
+};
+
+DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map)
+
+static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop)
+{
+	struct bpf_iter__bpf_map ctx;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+	int ret = 0;
+
+	ctx.meta = &meta;
+	ctx.map = v;
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (prog)
+		ret = bpf_iter_run_prog(prog, &ctx);
+
+	return ret;
+}
+
+static int bpf_map_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_map_seq_show(seq, v, false);
+}
+
+static void bpf_map_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_map_seq_show(seq, v, true);
+	else
+		bpf_map_put((struct bpf_map *)v);
+}
+
+static const struct seq_operations bpf_map_seq_ops = {
+	.start	= bpf_map_seq_start,
+	.next	= bpf_map_seq_next,
+	.stop	= bpf_map_seq_stop,
+	.show	= bpf_map_seq_show,
+};
+
+BTF_ID_LIST(btf_bpf_map_id)
+BTF_ID(struct, bpf_map)
+
+static const struct bpf_iter_seq_info bpf_map_seq_info = {
+	.seq_ops		= &bpf_map_seq_ops,
+	.init_seq_private	= NULL,
+	.fini_seq_private	= NULL,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_map_info),
+};
+
+static struct bpf_iter_reg bpf_map_reg_info = {
+	.target			= "bpf_map",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__bpf_map, map),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &bpf_map_seq_info,
+};
+
+static int bpf_iter_attach_map(struct bpf_prog *prog,
+			       union bpf_iter_link_info *linfo,
+			       struct bpf_iter_aux_info *aux)
+{
+	u32 key_acc_size, value_acc_size, key_size, value_size;
+	struct bpf_map *map;
+	bool is_percpu = false;
+	int err = -EINVAL;
+
+	if (!linfo->map.map_fd)
+		return -EBADF;
+
+	map = bpf_map_get_with_uref(linfo->map.map_fd);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+		is_percpu = true;
+	else if (map->map_type != BPF_MAP_TYPE_HASH &&
+		 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
+		 map->map_type != BPF_MAP_TYPE_ARRAY)
+		goto put_map;
+
+	key_acc_size = prog->aux->max_rdonly_access;
+	value_acc_size = prog->aux->max_rdwr_access;
+	key_size = map->key_size;
+	if (!is_percpu)
+		value_size = map->value_size;
+	else
+		value_size = round_up(map->value_size, 8) * num_possible_cpus();
+
+	if (key_acc_size > key_size || value_acc_size > value_size) {
+		err = -EACCES;
+		goto put_map;
+	}
+
+	aux->map = map;
+	return 0;
+
+put_map:
+	bpf_map_put_with_uref(map);
+	return err;
+}
+
+static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
+{
+	bpf_map_put_with_uref(aux->map);
+}
+
+void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
+			      struct seq_file *seq)
+{
+	seq_printf(seq, "map_id:\t%u\n", aux->map->id);
+}
+
+int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
+				struct bpf_link_info *info)
+{
+	info->iter.map.map_id = aux->map->id;
+	return 0;
+}
+
+DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,
+		     struct bpf_map *map, void *key, void *value)
+
+static const struct bpf_iter_reg bpf_map_elem_reg_info = {
+	.target			= "bpf_map_elem",
+	.attach_target		= bpf_iter_attach_map,
+	.detach_target		= bpf_iter_detach_map,
+	.show_fdinfo		= bpf_iter_map_show_fdinfo,
+	.fill_link_info		= bpf_iter_map_fill_link_info,
+	.ctx_arg_info_size	= 2,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__bpf_map_elem, key),
+		  PTR_TO_RDONLY_BUF_OR_NULL },
+		{ offsetof(struct bpf_iter__bpf_map_elem, value),
+		  PTR_TO_RDWR_BUF_OR_NULL },
+	},
+};
+
+static int __init bpf_map_iter_init(void)
+{
+	int ret;
+
+	bpf_map_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_map_id;
+	ret = bpf_iter_reg_target(&bpf_map_reg_info);
+	if (ret)
+		return ret;
+
+	return bpf_iter_reg_target(&bpf_map_elem_reg_info);
+}
+
+late_initcall(bpf_map_iter_init);
diff --git a/kernel/bpf/net_namespace.c b/kernel/bpf/net_namespace.c
new file mode 100644
index 0000000..542f275
--- /dev/null
+++ b/kernel/bpf/net_namespace.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <net/net_namespace.h>
+
+/*
+ * Functions to manage BPF programs attached to netns
+ */
+
+struct bpf_netns_link {
+	struct bpf_link	link;
+	enum bpf_attach_type type;
+	enum netns_bpf_attach_type netns_type;
+
+	/* We don't hold a ref to net in order to auto-detach the link
+	 * when netns is going away. Instead we rely on pernet
+	 * pre_exit callback to clear this pointer. Must be accessed
+	 * with netns_bpf_mutex held.
+	 */
+	struct net *net;
+	struct list_head node; /* node in list of links attached to net */
+};
+
+/* Protects updates to netns_bpf */
+DEFINE_MUTEX(netns_bpf_mutex);
+
+static void netns_bpf_attach_type_unneed(enum netns_bpf_attach_type type)
+{
+	switch (type) {
+#ifdef CONFIG_INET
+	case NETNS_BPF_SK_LOOKUP:
+		static_branch_dec(&bpf_sk_lookup_enabled);
+		break;
+#endif
+	default:
+		break;
+	}
+}
+
+static void netns_bpf_attach_type_need(enum netns_bpf_attach_type type)
+{
+	switch (type) {
+#ifdef CONFIG_INET
+	case NETNS_BPF_SK_LOOKUP:
+		static_branch_inc(&bpf_sk_lookup_enabled);
+		break;
+#endif
+	default:
+		break;
+	}
+}
+
+/* Must be called with netns_bpf_mutex held. */
+static void netns_bpf_run_array_detach(struct net *net,
+				       enum netns_bpf_attach_type type)
+{
+	struct bpf_prog_array *run_array;
+
+	run_array = rcu_replace_pointer(net->bpf.run_array[type], NULL,
+					lockdep_is_held(&netns_bpf_mutex));
+	bpf_prog_array_free(run_array);
+}
+
+static int link_index(struct net *net, enum netns_bpf_attach_type type,
+		      struct bpf_netns_link *link)
+{
+	struct bpf_netns_link *pos;
+	int i = 0;
+
+	list_for_each_entry(pos, &net->bpf.links[type], node) {
+		if (pos == link)
+			return i;
+		i++;
+	}
+	return -ENOENT;
+}
+
+static int link_count(struct net *net, enum netns_bpf_attach_type type)
+{
+	struct list_head *pos;
+	int i = 0;
+
+	list_for_each(pos, &net->bpf.links[type])
+		i++;
+	return i;
+}
+
+static void fill_prog_array(struct net *net, enum netns_bpf_attach_type type,
+			    struct bpf_prog_array *prog_array)
+{
+	struct bpf_netns_link *pos;
+	unsigned int i = 0;
+
+	list_for_each_entry(pos, &net->bpf.links[type], node) {
+		prog_array->items[i].prog = pos->link.prog;
+		i++;
+	}
+}
+
+static void bpf_netns_link_release(struct bpf_link *link)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	enum netns_bpf_attach_type type = net_link->netns_type;
+	struct bpf_prog_array *old_array, *new_array;
+	struct net *net;
+	int cnt, idx;
+
+	mutex_lock(&netns_bpf_mutex);
+
+	/* We can race with cleanup_net, but if we see a non-NULL
+	 * struct net pointer, pre_exit has not run yet and wait for
+	 * netns_bpf_mutex.
+	 */
+	net = net_link->net;
+	if (!net)
+		goto out_unlock;
+
+	/* Mark attach point as unused */
+	netns_bpf_attach_type_unneed(type);
+
+	/* Remember link position in case of safe delete */
+	idx = link_index(net, type, net_link);
+	list_del(&net_link->node);
+
+	cnt = link_count(net, type);
+	if (!cnt) {
+		netns_bpf_run_array_detach(net, type);
+		goto out_unlock;
+	}
+
+	old_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	new_array = bpf_prog_array_alloc(cnt, GFP_KERNEL);
+	if (!new_array) {
+		WARN_ON(bpf_prog_array_delete_safe_at(old_array, idx));
+		goto out_unlock;
+	}
+	fill_prog_array(net, type, new_array);
+	rcu_assign_pointer(net->bpf.run_array[type], new_array);
+	bpf_prog_array_free(old_array);
+
+out_unlock:
+	net_link->net = NULL;
+	mutex_unlock(&netns_bpf_mutex);
+}
+
+static int bpf_netns_link_detach(struct bpf_link *link)
+{
+	bpf_netns_link_release(link);
+	return 0;
+}
+
+static void bpf_netns_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+
+	kfree(net_link);
+}
+
+static int bpf_netns_link_update_prog(struct bpf_link *link,
+				      struct bpf_prog *new_prog,
+				      struct bpf_prog *old_prog)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	enum netns_bpf_attach_type type = net_link->netns_type;
+	struct bpf_prog_array *run_array;
+	struct net *net;
+	int idx, ret;
+
+	if (old_prog && old_prog != link->prog)
+		return -EPERM;
+	if (new_prog->type != link->prog->type)
+		return -EINVAL;
+
+	mutex_lock(&netns_bpf_mutex);
+
+	net = net_link->net;
+	if (!net || !check_net(net)) {
+		/* Link auto-detached or netns dying */
+		ret = -ENOLINK;
+		goto out_unlock;
+	}
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	idx = link_index(net, type, net_link);
+	ret = bpf_prog_array_update_at(run_array, idx, new_prog);
+	if (ret)
+		goto out_unlock;
+
+	old_prog = xchg(&link->prog, new_prog);
+	bpf_prog_put(old_prog);
+
+out_unlock:
+	mutex_unlock(&netns_bpf_mutex);
+	return ret;
+}
+
+static int bpf_netns_link_fill_info(const struct bpf_link *link,
+				    struct bpf_link_info *info)
+{
+	const struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	unsigned int inum = 0;
+	struct net *net;
+
+	mutex_lock(&netns_bpf_mutex);
+	net = net_link->net;
+	if (net && check_net(net))
+		inum = net->ns.inum;
+	mutex_unlock(&netns_bpf_mutex);
+
+	info->netns.netns_ino = inum;
+	info->netns.attach_type = net_link->type;
+	return 0;
+}
+
+static void bpf_netns_link_show_fdinfo(const struct bpf_link *link,
+				       struct seq_file *seq)
+{
+	struct bpf_link_info info = {};
+
+	bpf_netns_link_fill_info(link, &info);
+	seq_printf(seq,
+		   "netns_ino:\t%u\n"
+		   "attach_type:\t%u\n",
+		   info.netns.netns_ino,
+		   info.netns.attach_type);
+}
+
+static const struct bpf_link_ops bpf_netns_link_ops = {
+	.release = bpf_netns_link_release,
+	.dealloc = bpf_netns_link_dealloc,
+	.detach = bpf_netns_link_detach,
+	.update_prog = bpf_netns_link_update_prog,
+	.fill_link_info = bpf_netns_link_fill_info,
+	.show_fdinfo = bpf_netns_link_show_fdinfo,
+};
+
+/* Must be called with netns_bpf_mutex held. */
+static int __netns_bpf_prog_query(const union bpf_attr *attr,
+				  union bpf_attr __user *uattr,
+				  struct net *net,
+				  enum netns_bpf_attach_type type)
+{
+	__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
+	struct bpf_prog_array *run_array;
+	u32 prog_cnt = 0, flags = 0;
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	if (run_array)
+		prog_cnt = bpf_prog_array_length(run_array);
+
+	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
+		return -EFAULT;
+	if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
+		return -EFAULT;
+	if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
+		return 0;
+
+	return bpf_prog_array_copy_to_user(run_array, prog_ids,
+					   attr->query.prog_cnt);
+}
+
+int netns_bpf_prog_query(const union bpf_attr *attr,
+			 union bpf_attr __user *uattr)
+{
+	enum netns_bpf_attach_type type;
+	struct net *net;
+	int ret;
+
+	if (attr->query.query_flags)
+		return -EINVAL;
+
+	type = to_netns_bpf_attach_type(attr->query.attach_type);
+	if (type < 0)
+		return -EINVAL;
+
+	net = get_net_ns_by_fd(attr->query.target_fd);
+	if (IS_ERR(net))
+		return PTR_ERR(net);
+
+	mutex_lock(&netns_bpf_mutex);
+	ret = __netns_bpf_prog_query(attr, uattr, net, type);
+	mutex_unlock(&netns_bpf_mutex);
+
+	put_net(net);
+	return ret;
+}
+
+int netns_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	struct bpf_prog_array *run_array;
+	enum netns_bpf_attach_type type;
+	struct bpf_prog *attached;
+	struct net *net;
+	int ret;
+
+	if (attr->target_fd || attr->attach_flags || attr->replace_bpf_fd)
+		return -EINVAL;
+
+	type = to_netns_bpf_attach_type(attr->attach_type);
+	if (type < 0)
+		return -EINVAL;
+
+	net = current->nsproxy->net_ns;
+	mutex_lock(&netns_bpf_mutex);
+
+	/* Attaching prog directly is not compatible with links */
+	if (!list_empty(&net->bpf.links[type])) {
+		ret = -EEXIST;
+		goto out_unlock;
+	}
+
+	switch (type) {
+	case NETNS_BPF_FLOW_DISSECTOR:
+		ret = flow_dissector_bpf_prog_attach_check(net, prog);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	if (ret)
+		goto out_unlock;
+
+	attached = net->bpf.progs[type];
+	if (attached == prog) {
+		/* The same program cannot be attached twice */
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	if (run_array) {
+		WRITE_ONCE(run_array->items[0].prog, prog);
+	} else {
+		run_array = bpf_prog_array_alloc(1, GFP_KERNEL);
+		if (!run_array) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+		run_array->items[0].prog = prog;
+		rcu_assign_pointer(net->bpf.run_array[type], run_array);
+	}
+
+	net->bpf.progs[type] = prog;
+	if (attached)
+		bpf_prog_put(attached);
+
+out_unlock:
+	mutex_unlock(&netns_bpf_mutex);
+
+	return ret;
+}
+
+/* Must be called with netns_bpf_mutex held. */
+static int __netns_bpf_prog_detach(struct net *net,
+				   enum netns_bpf_attach_type type,
+				   struct bpf_prog *old)
+{
+	struct bpf_prog *attached;
+
+	/* Progs attached via links cannot be detached */
+	if (!list_empty(&net->bpf.links[type]))
+		return -EINVAL;
+
+	attached = net->bpf.progs[type];
+	if (!attached || attached != old)
+		return -ENOENT;
+	netns_bpf_run_array_detach(net, type);
+	net->bpf.progs[type] = NULL;
+	bpf_prog_put(attached);
+	return 0;
+}
+
+int netns_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
+{
+	enum netns_bpf_attach_type type;
+	struct bpf_prog *prog;
+	int ret;
+
+	if (attr->target_fd)
+		return -EINVAL;
+
+	type = to_netns_bpf_attach_type(attr->attach_type);
+	if (type < 0)
+		return -EINVAL;
+
+	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	mutex_lock(&netns_bpf_mutex);
+	ret = __netns_bpf_prog_detach(current->nsproxy->net_ns, type, prog);
+	mutex_unlock(&netns_bpf_mutex);
+
+	bpf_prog_put(prog);
+
+	return ret;
+}
+
+static int netns_bpf_max_progs(enum netns_bpf_attach_type type)
+{
+	switch (type) {
+	case NETNS_BPF_FLOW_DISSECTOR:
+		return 1;
+	case NETNS_BPF_SK_LOOKUP:
+		return 64;
+	default:
+		return 0;
+	}
+}
+
+static int netns_bpf_link_attach(struct net *net, struct bpf_link *link,
+				 enum netns_bpf_attach_type type)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	struct bpf_prog_array *run_array;
+	int cnt, err;
+
+	mutex_lock(&netns_bpf_mutex);
+
+	cnt = link_count(net, type);
+	if (cnt >= netns_bpf_max_progs(type)) {
+		err = -E2BIG;
+		goto out_unlock;
+	}
+	/* Links are not compatible with attaching prog directly */
+	if (net->bpf.progs[type]) {
+		err = -EEXIST;
+		goto out_unlock;
+	}
+
+	switch (type) {
+	case NETNS_BPF_FLOW_DISSECTOR:
+		err = flow_dissector_bpf_prog_attach_check(net, link->prog);
+		break;
+	case NETNS_BPF_SK_LOOKUP:
+		err = 0; /* nothing to check */
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+	if (err)
+		goto out_unlock;
+
+	run_array = bpf_prog_array_alloc(cnt + 1, GFP_KERNEL);
+	if (!run_array) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	list_add_tail(&net_link->node, &net->bpf.links[type]);
+
+	fill_prog_array(net, type, run_array);
+	run_array = rcu_replace_pointer(net->bpf.run_array[type], run_array,
+					lockdep_is_held(&netns_bpf_mutex));
+	bpf_prog_array_free(run_array);
+
+	/* Mark attach point as used */
+	netns_bpf_attach_type_need(type);
+
+out_unlock:
+	mutex_unlock(&netns_bpf_mutex);
+	return err;
+}
+
+int netns_bpf_link_create(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	enum netns_bpf_attach_type netns_type;
+	struct bpf_link_primer link_primer;
+	struct bpf_netns_link *net_link;
+	enum bpf_attach_type type;
+	struct net *net;
+	int err;
+
+	if (attr->link_create.flags)
+		return -EINVAL;
+
+	type = attr->link_create.attach_type;
+	netns_type = to_netns_bpf_attach_type(type);
+	if (netns_type < 0)
+		return -EINVAL;
+
+	net = get_net_ns_by_fd(attr->link_create.target_fd);
+	if (IS_ERR(net))
+		return PTR_ERR(net);
+
+	net_link = kzalloc(sizeof(*net_link), GFP_USER);
+	if (!net_link) {
+		err = -ENOMEM;
+		goto out_put_net;
+	}
+	bpf_link_init(&net_link->link, BPF_LINK_TYPE_NETNS,
+		      &bpf_netns_link_ops, prog);
+	net_link->net = net;
+	net_link->type = type;
+	net_link->netns_type = netns_type;
+
+	err = bpf_link_prime(&net_link->link, &link_primer);
+	if (err) {
+		kfree(net_link);
+		goto out_put_net;
+	}
+
+	err = netns_bpf_link_attach(net, &net_link->link, netns_type);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		goto out_put_net;
+	}
+
+	put_net(net);
+	return bpf_link_settle(&link_primer);
+
+out_put_net:
+	put_net(net);
+	return err;
+}
+
+static int __net_init netns_bpf_pernet_init(struct net *net)
+{
+	int type;
+
+	for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++)
+		INIT_LIST_HEAD(&net->bpf.links[type]);
+
+	return 0;
+}
+
+static void __net_exit netns_bpf_pernet_pre_exit(struct net *net)
+{
+	enum netns_bpf_attach_type type;
+	struct bpf_netns_link *net_link;
+
+	mutex_lock(&netns_bpf_mutex);
+	for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++) {
+		netns_bpf_run_array_detach(net, type);
+		list_for_each_entry(net_link, &net->bpf.links[type], node) {
+			net_link->net = NULL; /* auto-detach link */
+			netns_bpf_attach_type_unneed(type);
+		}
+		if (net->bpf.progs[type])
+			bpf_prog_put(net->bpf.progs[type]);
+	}
+	mutex_unlock(&netns_bpf_mutex);
+}
+
+static struct pernet_operations netns_bpf_pernet_ops __net_initdata = {
+	.init = netns_bpf_pernet_init,
+	.pre_exit = netns_bpf_pernet_pre_exit,
+};
+
+static int __init netns_bpf_init(void)
+{
+	return register_pernet_subsys(&netns_bpf_pernet_ops);
+}
+
+subsys_initcall(netns_bpf_init);
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 3668a0b..bd09290 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -302,14 +302,14 @@
 	struct inode *ns_inode;
 	struct path ns_path;
 	char __user *uinsns;
-	void *res;
+	int res;
 	u32 ulen;
 
 	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
-	if (IS_ERR(res)) {
+	if (res) {
 		if (!info->ifindex)
 			return -ENODEV;
-		return PTR_ERR(res);
+		return res;
 	}
 
 	down_read(&bpf_devs_lock);
@@ -526,13 +526,13 @@
 	};
 	struct inode *ns_inode;
 	struct path ns_path;
-	void *res;
+	int res;
 
 	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
-	if (IS_ERR(res)) {
+	if (res) {
 		if (!info->ifindex)
 			return -ENODEV;
-		return PTR_ERR(res);
+		return res;
 	}
 
 	ns_inode = ns_path.dentry->d_inode;
diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c
index 6e09014..3d897de 100644
--- a/kernel/bpf/percpu_freelist.c
+++ b/kernel/bpf/percpu_freelist.c
@@ -17,6 +17,8 @@
 		raw_spin_lock_init(&head->lock);
 		head->first = NULL;
 	}
+	raw_spin_lock_init(&s->extralist.lock);
+	s->extralist.first = NULL;
 	return 0;
 }
 
@@ -25,21 +27,65 @@
 	free_percpu(s->freelist);
 }
 
+static inline void pcpu_freelist_push_node(struct pcpu_freelist_head *head,
+					   struct pcpu_freelist_node *node)
+{
+	node->next = head->first;
+	head->first = node;
+}
+
 static inline void ___pcpu_freelist_push(struct pcpu_freelist_head *head,
 					 struct pcpu_freelist_node *node)
 {
 	raw_spin_lock(&head->lock);
-	node->next = head->first;
-	head->first = node;
+	pcpu_freelist_push_node(head, node);
 	raw_spin_unlock(&head->lock);
 }
 
+static inline bool pcpu_freelist_try_push_extra(struct pcpu_freelist *s,
+						struct pcpu_freelist_node *node)
+{
+	if (!raw_spin_trylock(&s->extralist.lock))
+		return false;
+
+	pcpu_freelist_push_node(&s->extralist, node);
+	raw_spin_unlock(&s->extralist.lock);
+	return true;
+}
+
+static inline void ___pcpu_freelist_push_nmi(struct pcpu_freelist *s,
+					     struct pcpu_freelist_node *node)
+{
+	int cpu, orig_cpu;
+
+	orig_cpu = cpu = raw_smp_processor_id();
+	while (1) {
+		struct pcpu_freelist_head *head;
+
+		head = per_cpu_ptr(s->freelist, cpu);
+		if (raw_spin_trylock(&head->lock)) {
+			pcpu_freelist_push_node(head, node);
+			raw_spin_unlock(&head->lock);
+			return;
+		}
+		cpu = cpumask_next(cpu, cpu_possible_mask);
+		if (cpu >= nr_cpu_ids)
+			cpu = 0;
+
+		/* cannot lock any per cpu lock, try extralist */
+		if (cpu == orig_cpu &&
+		    pcpu_freelist_try_push_extra(s, node))
+			return;
+	}
+}
+
 void __pcpu_freelist_push(struct pcpu_freelist *s,
 			struct pcpu_freelist_node *node)
 {
-	struct pcpu_freelist_head *head = this_cpu_ptr(s->freelist);
-
-	___pcpu_freelist_push(head, node);
+	if (in_nmi())
+		___pcpu_freelist_push_nmi(s, node);
+	else
+		___pcpu_freelist_push(this_cpu_ptr(s->freelist), node);
 }
 
 void pcpu_freelist_push(struct pcpu_freelist *s,
@@ -56,21 +102,16 @@
 			    u32 nr_elems)
 {
 	struct pcpu_freelist_head *head;
-	unsigned long flags;
 	int i, cpu, pcpu_entries;
 
 	pcpu_entries = nr_elems / num_possible_cpus() + 1;
 	i = 0;
 
-	/* disable irq to workaround lockdep false positive
-	 * in bpf usage pcpu_freelist_populate() will never race
-	 * with pcpu_freelist_push()
-	 */
-	local_irq_save(flags);
 	for_each_possible_cpu(cpu) {
 again:
 		head = per_cpu_ptr(s->freelist, cpu);
-		___pcpu_freelist_push(head, buf);
+		/* No locking required as this is not visible yet. */
+		pcpu_freelist_push_node(head, buf);
 		i++;
 		buf += elem_size;
 		if (i == nr_elems)
@@ -78,10 +119,9 @@
 		if (i % pcpu_entries)
 			goto again;
 	}
-	local_irq_restore(flags);
 }
 
-struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
+static struct pcpu_freelist_node *___pcpu_freelist_pop(struct pcpu_freelist *s)
 {
 	struct pcpu_freelist_head *head;
 	struct pcpu_freelist_node *node;
@@ -102,8 +142,59 @@
 		if (cpu >= nr_cpu_ids)
 			cpu = 0;
 		if (cpu == orig_cpu)
-			return NULL;
+			break;
 	}
+
+	/* per cpu lists are all empty, try extralist */
+	raw_spin_lock(&s->extralist.lock);
+	node = s->extralist.first;
+	if (node)
+		s->extralist.first = node->next;
+	raw_spin_unlock(&s->extralist.lock);
+	return node;
+}
+
+static struct pcpu_freelist_node *
+___pcpu_freelist_pop_nmi(struct pcpu_freelist *s)
+{
+	struct pcpu_freelist_head *head;
+	struct pcpu_freelist_node *node;
+	int orig_cpu, cpu;
+
+	orig_cpu = cpu = raw_smp_processor_id();
+	while (1) {
+		head = per_cpu_ptr(s->freelist, cpu);
+		if (raw_spin_trylock(&head->lock)) {
+			node = head->first;
+			if (node) {
+				head->first = node->next;
+				raw_spin_unlock(&head->lock);
+				return node;
+			}
+			raw_spin_unlock(&head->lock);
+		}
+		cpu = cpumask_next(cpu, cpu_possible_mask);
+		if (cpu >= nr_cpu_ids)
+			cpu = 0;
+		if (cpu == orig_cpu)
+			break;
+	}
+
+	/* cannot pop from per cpu lists, try extralist */
+	if (!raw_spin_trylock(&s->extralist.lock))
+		return NULL;
+	node = s->extralist.first;
+	if (node)
+		s->extralist.first = node->next;
+	raw_spin_unlock(&s->extralist.lock);
+	return node;
+}
+
+struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
+{
+	if (in_nmi())
+		return ___pcpu_freelist_pop_nmi(s);
+	return ___pcpu_freelist_pop(s);
 }
 
 struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s)
diff --git a/kernel/bpf/percpu_freelist.h b/kernel/bpf/percpu_freelist.h
index fbf8a8a..3c76553 100644
--- a/kernel/bpf/percpu_freelist.h
+++ b/kernel/bpf/percpu_freelist.h
@@ -13,6 +13,7 @@
 
 struct pcpu_freelist {
 	struct pcpu_freelist_head __percpu *freelist;
+	struct pcpu_freelist_head extralist;
 };
 
 struct pcpu_freelist_node {
diff --git a/kernel/bpf/preload/.gitignore b/kernel/bpf/preload/.gitignore
new file mode 100644
index 0000000..856a4c5
--- /dev/null
+++ b/kernel/bpf/preload/.gitignore
@@ -0,0 +1,4 @@
+/FEATURE-DUMP.libbpf
+/bpf_helper_defs.h
+/feature
+/bpf_preload_umd
diff --git a/kernel/bpf/preload/Kconfig b/kernel/bpf/preload/Kconfig
new file mode 100644
index 0000000..26bced2
--- /dev/null
+++ b/kernel/bpf/preload/Kconfig
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config USERMODE_DRIVER
+	bool
+	default n
+
+menuconfig BPF_PRELOAD
+	bool "Preload BPF file system with kernel specific program and map iterators"
+	depends on BPF
+	depends on BPF_SYSCALL
+	# The dependency on !COMPILE_TEST prevents it from being enabled
+	# in allmodconfig or allyesconfig configurations
+	depends on !COMPILE_TEST
+	select USERMODE_DRIVER
+	help
+	  This builds kernel module with several embedded BPF programs that are
+	  pinned into BPF FS mount point as human readable files that are
+	  useful in debugging and introspection of BPF programs and maps.
+
+if BPF_PRELOAD
+config BPF_PRELOAD_UMD
+	tristate "bpf_preload kernel module with user mode driver"
+	depends on CC_CAN_LINK
+	depends on m || CC_CAN_LINK_STATIC
+	default m
+	help
+	  This builds bpf_preload kernel module with embedded user mode driver.
+endif
diff --git a/kernel/bpf/preload/Makefile b/kernel/bpf/preload/Makefile
new file mode 100644
index 0000000..1951332
--- /dev/null
+++ b/kernel/bpf/preload/Makefile
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+
+LIBBPF_SRCS = $(srctree)/tools/lib/bpf/
+LIBBPF_A = $(obj)/libbpf.a
+LIBBPF_OUT = $(abspath $(obj))
+
+# Although not in use by libbpf's Makefile, set $(O) so that the "dummy" test
+# in tools/scripts/Makefile.include always succeeds when building the kernel
+# with $(O) pointing to a relative path, as in "make O=build bindeb-pkg".
+$(LIBBPF_A):
+	$(Q)$(MAKE) -C $(LIBBPF_SRCS) O=$(LIBBPF_OUT)/ OUTPUT=$(LIBBPF_OUT)/ $(LIBBPF_OUT)/libbpf.a
+
+userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \
+	-I $(srctree)/tools/lib/ -Wno-unused-result
+
+userprogs := bpf_preload_umd
+
+clean-files := $(userprogs) bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
+
+bpf_preload_umd-objs := iterators/iterators.o
+bpf_preload_umd-userldlibs := $(LIBBPF_A) -lelf -lz
+
+$(obj)/bpf_preload_umd: $(LIBBPF_A)
+
+$(obj)/bpf_preload_umd_blob.o: $(obj)/bpf_preload_umd
+
+obj-$(CONFIG_BPF_PRELOAD_UMD) += bpf_preload.o
+bpf_preload-objs += bpf_preload_kern.o bpf_preload_umd_blob.o
diff --git a/kernel/bpf/preload/bpf_preload.h b/kernel/bpf/preload/bpf_preload.h
new file mode 100644
index 0000000..2f99322
--- /dev/null
+++ b/kernel/bpf/preload/bpf_preload.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BPF_PRELOAD_H
+#define _BPF_PRELOAD_H
+
+#include <linux/usermode_driver.h>
+#include "iterators/bpf_preload_common.h"
+
+struct bpf_preload_ops {
+        struct umd_info info;
+	int (*preload)(struct bpf_preload_info *);
+	int (*finish)(void);
+	struct module *owner;
+};
+extern struct bpf_preload_ops *bpf_preload_ops;
+#define BPF_PRELOAD_LINKS 2
+#endif
diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c
new file mode 100644
index 0000000..53736e5
--- /dev/null
+++ b/kernel/bpf/preload/bpf_preload_kern.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pid.h>
+#include <linux/fs.h>
+#include <linux/sched/signal.h>
+#include "bpf_preload.h"
+
+extern char bpf_preload_umd_start;
+extern char bpf_preload_umd_end;
+
+static int preload(struct bpf_preload_info *obj);
+static int finish(void);
+
+static struct bpf_preload_ops umd_ops = {
+	.info.driver_name = "bpf_preload",
+	.preload = preload,
+	.finish = finish,
+	.owner = THIS_MODULE,
+};
+
+static int preload(struct bpf_preload_info *obj)
+{
+	int magic = BPF_PRELOAD_START;
+	loff_t pos = 0;
+	int i, err;
+	ssize_t n;
+
+	err = fork_usermode_driver(&umd_ops.info);
+	if (err)
+		return err;
+
+	/* send the start magic to let UMD proceed with loading BPF progs */
+	n = kernel_write(umd_ops.info.pipe_to_umh,
+			 &magic, sizeof(magic), &pos);
+	if (n != sizeof(magic))
+		return -EPIPE;
+
+	/* receive bpf_link IDs and names from UMD */
+	pos = 0;
+	for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+		n = kernel_read(umd_ops.info.pipe_from_umh,
+				&obj[i], sizeof(*obj), &pos);
+		if (n != sizeof(*obj))
+			return -EPIPE;
+	}
+	return 0;
+}
+
+static int finish(void)
+{
+	int magic = BPF_PRELOAD_END;
+	struct pid *tgid;
+	loff_t pos = 0;
+	ssize_t n;
+
+	/* send the last magic to UMD. It will do a normal exit. */
+	n = kernel_write(umd_ops.info.pipe_to_umh,
+			 &magic, sizeof(magic), &pos);
+	if (n != sizeof(magic))
+		return -EPIPE;
+
+	tgid = umd_ops.info.tgid;
+	if (tgid) {
+		wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
+		umd_cleanup_helper(&umd_ops.info);
+	}
+	return 0;
+}
+
+static int __init load_umd(void)
+{
+	int err;
+
+	err = umd_load_blob(&umd_ops.info, &bpf_preload_umd_start,
+			    &bpf_preload_umd_end - &bpf_preload_umd_start);
+	if (err)
+		return err;
+	bpf_preload_ops = &umd_ops;
+	return err;
+}
+
+static void __exit fini_umd(void)
+{
+	struct pid *tgid;
+
+	bpf_preload_ops = NULL;
+
+	/* kill UMD in case it's still there due to earlier error */
+	tgid = umd_ops.info.tgid;
+	if (tgid) {
+		kill_pid(tgid, SIGKILL, 1);
+
+		wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
+		umd_cleanup_helper(&umd_ops.info);
+	}
+	umd_unload_blob(&umd_ops.info);
+}
+late_initcall(load_umd);
+module_exit(fini_umd);
+MODULE_LICENSE("GPL");
diff --git a/kernel/bpf/preload/bpf_preload_umd_blob.S b/kernel/bpf/preload/bpf_preload_umd_blob.S
new file mode 100644
index 0000000..f1f4022
--- /dev/null
+++ b/kernel/bpf/preload/bpf_preload_umd_blob.S
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+	.section .init.rodata, "a"
+	.global bpf_preload_umd_start
+bpf_preload_umd_start:
+	.incbin "kernel/bpf/preload/bpf_preload_umd"
+	.global bpf_preload_umd_end
+bpf_preload_umd_end:
diff --git a/kernel/bpf/preload/iterators/.gitignore b/kernel/bpf/preload/iterators/.gitignore
new file mode 100644
index 0000000..ffdb702
--- /dev/null
+++ b/kernel/bpf/preload/iterators/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/.output
diff --git a/kernel/bpf/preload/iterators/Makefile b/kernel/bpf/preload/iterators/Makefile
new file mode 100644
index 0000000..28fa8c1
--- /dev/null
+++ b/kernel/bpf/preload/iterators/Makefile
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0
+OUTPUT := .output
+CLANG ?= clang
+LLC ?= llc
+LLVM_STRIP ?= llvm-strip
+DEFAULT_BPFTOOL := $(OUTPUT)/sbin/bpftool
+BPFTOOL ?= $(DEFAULT_BPFTOOL)
+LIBBPF_SRC := $(abspath ../../../../tools/lib/bpf)
+BPFOBJ := $(OUTPUT)/libbpf.a
+BPF_INCLUDE := $(OUTPUT)
+INCLUDES := -I$(OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../../../tools/lib)        \
+       -I$(abspath ../../../../tools/include/uapi)
+CFLAGS := -g -Wall
+
+abs_out := $(abspath $(OUTPUT))
+ifeq ($(V),1)
+Q =
+msg =
+else
+Q = @
+msg = @printf '  %-8s %s%s\n' "$(1)" "$(notdir $(2))" "$(if $(3), $(3))";
+MAKEFLAGS += --no-print-directory
+submake_extras := feature_display=0
+endif
+
+.DELETE_ON_ERROR:
+
+.PHONY: all clean
+
+all: iterators.skel.h
+
+clean:
+	$(call msg,CLEAN)
+	$(Q)rm -rf $(OUTPUT) iterators
+
+iterators.skel.h: $(OUTPUT)/iterators.bpf.o | $(BPFTOOL)
+	$(call msg,GEN-SKEL,$@)
+	$(Q)$(BPFTOOL) gen skeleton $< > $@
+
+
+$(OUTPUT)/iterators.bpf.o: iterators.bpf.c $(BPFOBJ) | $(OUTPUT)
+	$(call msg,BPF,$@)
+	$(Q)$(CLANG) -g -O2 -target bpf $(INCLUDES)			      \
+		 -c $(filter %.c,$^) -o $@ &&				      \
+	$(LLVM_STRIP) -g $@
+
+$(OUTPUT):
+	$(call msg,MKDIR,$@)
+	$(Q)mkdir -p $(OUTPUT)
+
+$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)
+	$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC)			       \
+		    OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
+
+$(DEFAULT_BPFTOOL):
+	$(Q)$(MAKE) $(submake_extras) -C ../../../../tools/bpf/bpftool			      \
+		    prefix= OUTPUT=$(abs_out)/ DESTDIR=$(abs_out) install
diff --git a/kernel/bpf/preload/iterators/README b/kernel/bpf/preload/iterators/README
new file mode 100644
index 0000000..7fd6d39
--- /dev/null
+++ b/kernel/bpf/preload/iterators/README
@@ -0,0 +1,4 @@
+WARNING:
+If you change "iterators.bpf.c" do "make -j" in this directory to rebuild "iterators.skel.h".
+Make sure to have clang 10 installed.
+See Documentation/bpf/bpf_devel_QA.rst
diff --git a/kernel/bpf/preload/iterators/bpf_preload_common.h b/kernel/bpf/preload/iterators/bpf_preload_common.h
new file mode 100644
index 0000000..8464d1a
--- /dev/null
+++ b/kernel/bpf/preload/iterators/bpf_preload_common.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BPF_PRELOAD_COMMON_H
+#define _BPF_PRELOAD_COMMON_H
+
+#define BPF_PRELOAD_START 0x5555
+#define BPF_PRELOAD_END 0xAAAA
+
+struct bpf_preload_info {
+	char link_name[16];
+	int link_id;
+};
+
+#endif
diff --git a/kernel/bpf/preload/iterators/iterators.bpf.c b/kernel/bpf/preload/iterators/iterators.bpf.c
new file mode 100644
index 0000000..52aa7b3
--- /dev/null
+++ b/kernel/bpf/preload/iterators/iterators.bpf.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)
+struct seq_file;
+struct bpf_iter_meta {
+	struct seq_file *seq;
+	__u64 session_id;
+	__u64 seq_num;
+};
+
+struct bpf_map {
+	__u32 id;
+	char name[16];
+	__u32 max_entries;
+};
+
+struct bpf_iter__bpf_map {
+	struct bpf_iter_meta *meta;
+	struct bpf_map *map;
+};
+
+struct btf_type {
+	__u32 name_off;
+};
+
+struct btf_header {
+	__u32   str_len;
+};
+
+struct btf {
+	const char *strings;
+	struct btf_type **types;
+	struct btf_header hdr;
+};
+
+struct bpf_prog_aux {
+	__u32 id;
+	char name[16];
+	const char *attach_func_name;
+	struct bpf_prog *dst_prog;
+	struct bpf_func_info *func_info;
+	struct btf *btf;
+};
+
+struct bpf_prog {
+	struct bpf_prog_aux *aux;
+};
+
+struct bpf_iter__bpf_prog {
+	struct bpf_iter_meta *meta;
+	struct bpf_prog *prog;
+};
+#pragma clang attribute pop
+
+static const char *get_name(struct btf *btf, long btf_id, const char *fallback)
+{
+	struct btf_type **types, *t;
+	unsigned int name_off;
+	const char *str;
+
+	if (!btf)
+		return fallback;
+	str = btf->strings;
+	types = btf->types;
+	bpf_probe_read_kernel(&t, sizeof(t), types + btf_id);
+	name_off = BPF_CORE_READ(t, name_off);
+	if (name_off >= btf->hdr.str_len)
+		return fallback;
+	return str + name_off;
+}
+
+SEC("iter/bpf_map")
+int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
+{
+	struct seq_file *seq = ctx->meta->seq;
+	__u64 seq_num = ctx->meta->seq_num;
+	struct bpf_map *map = ctx->map;
+
+	if (!map)
+		return 0;
+
+	if (seq_num == 0)
+		BPF_SEQ_PRINTF(seq, "  id name             max_entries\n");
+
+	BPF_SEQ_PRINTF(seq, "%4u %-16s%6d\n", map->id, map->name, map->max_entries);
+	return 0;
+}
+
+SEC("iter/bpf_prog")
+int dump_bpf_prog(struct bpf_iter__bpf_prog *ctx)
+{
+	struct seq_file *seq = ctx->meta->seq;
+	__u64 seq_num = ctx->meta->seq_num;
+	struct bpf_prog *prog = ctx->prog;
+	struct bpf_prog_aux *aux;
+
+	if (!prog)
+		return 0;
+
+	aux = prog->aux;
+	if (seq_num == 0)
+		BPF_SEQ_PRINTF(seq, "  id name             attached\n");
+
+	BPF_SEQ_PRINTF(seq, "%4u %-16s %s %s\n", aux->id,
+		       get_name(aux->btf, aux->func_info[0].type_id, aux->name),
+		       aux->attach_func_name, aux->dst_prog->aux->name);
+	return 0;
+}
+char LICENSE[] SEC("license") = "GPL";
diff --git a/kernel/bpf/preload/iterators/iterators.c b/kernel/bpf/preload/iterators/iterators.c
new file mode 100644
index 0000000..b7ff879
--- /dev/null
+++ b/kernel/bpf/preload/iterators/iterators.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <argp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include <sys/mount.h>
+#include "iterators.skel.h"
+#include "bpf_preload_common.h"
+
+int to_kernel = -1;
+int from_kernel = 0;
+
+static int send_link_to_kernel(struct bpf_link *link, const char *link_name)
+{
+	struct bpf_preload_info obj = {};
+	struct bpf_link_info info = {};
+	__u32 info_len = sizeof(info);
+	int err;
+
+	err = bpf_obj_get_info_by_fd(bpf_link__fd(link), &info, &info_len);
+	if (err)
+		return err;
+	obj.link_id = info.id;
+	if (strlen(link_name) >= sizeof(obj.link_name))
+		return -E2BIG;
+	strcpy(obj.link_name, link_name);
+	if (write(to_kernel, &obj, sizeof(obj)) != sizeof(obj))
+		return -EPIPE;
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit rlim = { RLIM_INFINITY, RLIM_INFINITY };
+	struct iterators_bpf *skel;
+	int err, magic;
+	int debug_fd;
+
+	debug_fd = open("/dev/console", O_WRONLY | O_NOCTTY | O_CLOEXEC);
+	if (debug_fd < 0)
+		return 1;
+	to_kernel = dup(1);
+	close(1);
+	dup(debug_fd);
+	/* now stdin and stderr point to /dev/console */
+
+	read(from_kernel, &magic, sizeof(magic));
+	if (magic != BPF_PRELOAD_START) {
+		printf("bad start magic %d\n", magic);
+		return 1;
+	}
+	setrlimit(RLIMIT_MEMLOCK, &rlim);
+	/* libbpf opens BPF object and loads it into the kernel */
+	skel = iterators_bpf__open_and_load();
+	if (!skel) {
+		/* iterators.skel.h is little endian.
+		 * libbpf doesn't support automatic little->big conversion
+		 * of BPF bytecode yet.
+		 * The program load will fail in such case.
+		 */
+		printf("Failed load could be due to wrong endianness\n");
+		return 1;
+	}
+	err = iterators_bpf__attach(skel);
+	if (err)
+		goto cleanup;
+
+	/* send two bpf_link IDs with names to the kernel */
+	err = send_link_to_kernel(skel->links.dump_bpf_map, "maps.debug");
+	if (err)
+		goto cleanup;
+	err = send_link_to_kernel(skel->links.dump_bpf_prog, "progs.debug");
+	if (err)
+		goto cleanup;
+
+	/* The kernel will proceed with pinnging the links in bpffs.
+	 * UMD will wait on read from pipe.
+	 */
+	read(from_kernel, &magic, sizeof(magic));
+	if (magic != BPF_PRELOAD_END) {
+		printf("bad final magic %d\n", magic);
+		err = -EINVAL;
+	}
+cleanup:
+	iterators_bpf__destroy(skel);
+
+	return err != 0;
+}
diff --git a/kernel/bpf/preload/iterators/iterators.skel.h b/kernel/bpf/preload/iterators/iterators.skel.h
new file mode 100644
index 0000000..cf9a6a9
--- /dev/null
+++ b/kernel/bpf/preload/iterators/iterators.skel.h
@@ -0,0 +1,412 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/* THIS FILE IS AUTOGENERATED! */
+#ifndef __ITERATORS_BPF_SKEL_H__
+#define __ITERATORS_BPF_SKEL_H__
+
+#include <stdlib.h>
+#include <bpf/libbpf.h>
+
+struct iterators_bpf {
+	struct bpf_object_skeleton *skeleton;
+	struct bpf_object *obj;
+	struct {
+		struct bpf_map *rodata;
+	} maps;
+	struct {
+		struct bpf_program *dump_bpf_map;
+		struct bpf_program *dump_bpf_prog;
+	} progs;
+	struct {
+		struct bpf_link *dump_bpf_map;
+		struct bpf_link *dump_bpf_prog;
+	} links;
+	struct iterators_bpf__rodata {
+		char dump_bpf_map____fmt[35];
+		char dump_bpf_map____fmt_1[14];
+		char dump_bpf_prog____fmt[32];
+		char dump_bpf_prog____fmt_2[17];
+	} *rodata;
+};
+
+static void
+iterators_bpf__destroy(struct iterators_bpf *obj)
+{
+	if (!obj)
+		return;
+	if (obj->skeleton)
+		bpf_object__destroy_skeleton(obj->skeleton);
+	free(obj);
+}
+
+static inline int
+iterators_bpf__create_skeleton(struct iterators_bpf *obj);
+
+static inline struct iterators_bpf *
+iterators_bpf__open_opts(const struct bpf_object_open_opts *opts)
+{
+	struct iterators_bpf *obj;
+
+	obj = (struct iterators_bpf *)calloc(1, sizeof(*obj));
+	if (!obj)
+		return NULL;
+	if (iterators_bpf__create_skeleton(obj))
+		goto err;
+	if (bpf_object__open_skeleton(obj->skeleton, opts))
+		goto err;
+
+	return obj;
+err:
+	iterators_bpf__destroy(obj);
+	return NULL;
+}
+
+static inline struct iterators_bpf *
+iterators_bpf__open(void)
+{
+	return iterators_bpf__open_opts(NULL);
+}
+
+static inline int
+iterators_bpf__load(struct iterators_bpf *obj)
+{
+	return bpf_object__load_skeleton(obj->skeleton);
+}
+
+static inline struct iterators_bpf *
+iterators_bpf__open_and_load(void)
+{
+	struct iterators_bpf *obj;
+
+	obj = iterators_bpf__open();
+	if (!obj)
+		return NULL;
+	if (iterators_bpf__load(obj)) {
+		iterators_bpf__destroy(obj);
+		return NULL;
+	}
+	return obj;
+}
+
+static inline int
+iterators_bpf__attach(struct iterators_bpf *obj)
+{
+	return bpf_object__attach_skeleton(obj->skeleton);
+}
+
+static inline void
+iterators_bpf__detach(struct iterators_bpf *obj)
+{
+	return bpf_object__detach_skeleton(obj->skeleton);
+}
+
+static inline int
+iterators_bpf__create_skeleton(struct iterators_bpf *obj)
+{
+	struct bpf_object_skeleton *s;
+
+	s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));
+	if (!s)
+		return -1;
+	obj->skeleton = s;
+
+	s->sz = sizeof(*s);
+	s->name = "iterators_bpf";
+	s->obj = &obj->obj;
+
+	/* maps */
+	s->map_cnt = 1;
+	s->map_skel_sz = sizeof(*s->maps);
+	s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);
+	if (!s->maps)
+		goto err;
+
+	s->maps[0].name = "iterator.rodata";
+	s->maps[0].map = &obj->maps.rodata;
+	s->maps[0].mmaped = (void **)&obj->rodata;
+
+	/* programs */
+	s->prog_cnt = 2;
+	s->prog_skel_sz = sizeof(*s->progs);
+	s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);
+	if (!s->progs)
+		goto err;
+
+	s->progs[0].name = "dump_bpf_map";
+	s->progs[0].prog = &obj->progs.dump_bpf_map;
+	s->progs[0].link = &obj->links.dump_bpf_map;
+
+	s->progs[1].name = "dump_bpf_prog";
+	s->progs[1].prog = &obj->progs.dump_bpf_prog;
+	s->progs[1].link = &obj->links.dump_bpf_prog;
+
+	s->data_sz = 7176;
+	s->data = (void *)"\
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+\0\0\0\0\0\0\0\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+
+	return 0;
+err:
+	bpf_object__destroy_skeleton(s);
+	return -1;
+}
+
+#endif /* __ITERATORS_BPF_SKEL_H__ */
diff --git a/kernel/bpf/prog_iter.c b/kernel/bpf/prog_iter.c
new file mode 100644
index 0000000..53a73c8
--- /dev/null
+++ b/kernel/bpf/prog_iter.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+#include <linux/bpf.h>
+#include <linux/fs.h>
+#include <linux/filter.h>
+#include <linux/kernel.h>
+#include <linux/btf_ids.h>
+
+struct bpf_iter_seq_prog_info {
+	u32 prog_id;
+};
+
+static void *bpf_prog_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_prog_info *info = seq->private;
+	struct bpf_prog *prog;
+
+	prog = bpf_prog_get_curr_or_next(&info->prog_id);
+	if (!prog)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return prog;
+}
+
+static void *bpf_prog_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_prog_info *info = seq->private;
+
+	++*pos;
+	++info->prog_id;
+	bpf_prog_put((struct bpf_prog *)v);
+	return bpf_prog_get_curr_or_next(&info->prog_id);
+}
+
+struct bpf_iter__bpf_prog {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct bpf_prog *, prog);
+};
+
+DEFINE_BPF_ITER_FUNC(bpf_prog, struct bpf_iter_meta *meta, struct bpf_prog *prog)
+
+static int __bpf_prog_seq_show(struct seq_file *seq, void *v, bool in_stop)
+{
+	struct bpf_iter__bpf_prog ctx;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+	int ret = 0;
+
+	ctx.meta = &meta;
+	ctx.prog = v;
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (prog)
+		ret = bpf_iter_run_prog(prog, &ctx);
+
+	return ret;
+}
+
+static int bpf_prog_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_prog_seq_show(seq, v, false);
+}
+
+static void bpf_prog_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_prog_seq_show(seq, v, true);
+	else
+		bpf_prog_put((struct bpf_prog *)v);
+}
+
+static const struct seq_operations bpf_prog_seq_ops = {
+	.start	= bpf_prog_seq_start,
+	.next	= bpf_prog_seq_next,
+	.stop	= bpf_prog_seq_stop,
+	.show	= bpf_prog_seq_show,
+};
+
+BTF_ID_LIST(btf_bpf_prog_id)
+BTF_ID(struct, bpf_prog)
+
+static const struct bpf_iter_seq_info bpf_prog_seq_info = {
+	.seq_ops		= &bpf_prog_seq_ops,
+	.init_seq_private	= NULL,
+	.fini_seq_private	= NULL,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_prog_info),
+};
+
+static struct bpf_iter_reg bpf_prog_reg_info = {
+	.target			= "bpf_prog",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__bpf_prog, prog),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &bpf_prog_seq_info,
+};
+
+static int __init bpf_prog_iter_init(void)
+{
+	bpf_prog_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_prog_id;
+	return bpf_iter_reg_target(&bpf_prog_reg_info);
+}
+
+late_initcall(bpf_prog_iter_init);
diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
index f697647..0ee2347 100644
--- a/kernel/bpf/queue_stack_maps.c
+++ b/kernel/bpf/queue_stack_maps.c
@@ -19,7 +19,7 @@
 	u32 head, tail;
 	u32 size; /* max_entries + 1 */
 
-	char elements[0] __aligned(8);
+	char elements[] __aligned(8);
 };
 
 static struct bpf_queue_stack *bpf_queue_stack(struct bpf_map *map)
@@ -45,7 +45,7 @@
 /* Called from syscall */
 static int queue_stack_map_alloc_check(union bpf_attr *attr)
 {
-	if (!capable(CAP_SYS_ADMIN))
+	if (!bpf_capable())
 		return -EPERM;
 
 	/* check sanity of attributes */
@@ -101,13 +101,6 @@
 {
 	struct bpf_queue_stack *qs = bpf_queue_stack(map);
 
-	/* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
-	 * so the programs (can be more than one that used this map) were
-	 * disconnected from events. Wait for outstanding critical sections in
-	 * these programs to complete
-	 */
-	synchronize_rcu();
-
 	bpf_map_area_free(qs);
 }
 
@@ -262,7 +255,9 @@
 	return -EINVAL;
 }
 
+static int queue_map_btf_id;
 const struct bpf_map_ops queue_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = queue_stack_map_alloc_check,
 	.map_alloc = queue_stack_map_alloc,
 	.map_free = queue_stack_map_free,
@@ -273,9 +268,13 @@
 	.map_pop_elem = queue_map_pop_elem,
 	.map_peek_elem = queue_map_peek_elem,
 	.map_get_next_key = queue_stack_map_get_next_key,
+	.map_btf_name = "bpf_queue_stack",
+	.map_btf_id = &queue_map_btf_id,
 };
 
+static int stack_map_btf_id;
 const struct bpf_map_ops stack_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = queue_stack_map_alloc_check,
 	.map_alloc = queue_stack_map_alloc,
 	.map_free = queue_stack_map_free,
@@ -286,4 +285,6 @@
 	.map_pop_elem = stack_map_pop_elem,
 	.map_peek_elem = stack_map_peek_elem,
 	.map_get_next_key = queue_stack_map_get_next_key,
+	.map_btf_name = "bpf_queue_stack",
+	.map_btf_id = &stack_map_btf_id,
 };
diff --git a/kernel/bpf/reuseport_array.c b/kernel/bpf/reuseport_array.c
index 50c083b..a55cd54 100644
--- a/kernel/bpf/reuseport_array.c
+++ b/kernel/bpf/reuseport_array.c
@@ -20,11 +20,14 @@
 /* The caller must hold the reuseport_lock */
 void bpf_sk_reuseport_detach(struct sock *sk)
 {
-	struct sock __rcu **socks;
+	uintptr_t sk_user_data;
 
 	write_lock_bh(&sk->sk_callback_lock);
-	socks = sk->sk_user_data;
-	if (socks) {
+	sk_user_data = (uintptr_t)sk->sk_user_data;
+	if (sk_user_data & SK_USER_DATA_BPF) {
+		struct sock __rcu **socks;
+
+		socks = (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
 		WRITE_ONCE(sk->sk_user_data, NULL);
 		/*
 		 * Do not move this NULL assignment outside of
@@ -96,8 +99,6 @@
 	struct sock *sk;
 	u32 i;
 
-	synchronize_rcu();
-
 	/*
 	 * ops->map_*_elem() will not be able to access this
 	 * array now. Hence, this function only races with
@@ -154,7 +155,7 @@
 	struct bpf_map_memory mem;
 	u64 array_size;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!bpf_capable())
 		return ERR_PTR(-EPERM);
 
 	array_size = sizeof(*array);
@@ -190,7 +191,7 @@
 	rcu_read_lock();
 	sk = reuseport_array_lookup_elem(map, key);
 	if (sk) {
-		*(u64 *)value = sock_gen_cookie(sk);
+		*(u64 *)value = __sock_gen_cookie(sk);
 		err = 0;
 	} else {
 		err = -ENOENT;
@@ -252,6 +253,7 @@
 	struct sock *free_osk = NULL, *osk, *nsk;
 	struct sock_reuseport *reuse;
 	u32 index = *(u32 *)key;
+	uintptr_t sk_user_data;
 	struct socket *socket;
 	int err, fd;
 
@@ -305,12 +307,9 @@
 	if (err)
 		goto put_file_unlock;
 
-	/* Ensure reuse->reuseport_id is set */
-	err = reuseport_get_id(reuse);
-	if (err < 0)
-		goto put_file_unlock;
-
-	WRITE_ONCE(nsk->sk_user_data, &array->ptrs[index]);
+	sk_user_data = (uintptr_t)&array->ptrs[index] | SK_USER_DATA_NOCOPY |
+		SK_USER_DATA_BPF;
+	WRITE_ONCE(nsk->sk_user_data, (void *)sk_user_data);
 	rcu_assign_pointer(array->ptrs[index], nsk);
 	free_osk = osk;
 	err = 0;
@@ -350,11 +349,15 @@
 	return 0;
 }
 
+static int reuseport_array_map_btf_id;
 const struct bpf_map_ops reuseport_array_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc_check = reuseport_array_alloc_check,
 	.map_alloc = reuseport_array_alloc,
 	.map_free = reuseport_array_free,
 	.map_lookup_elem = reuseport_array_lookup_elem,
 	.map_get_next_key = reuseport_array_get_next_key,
 	.map_delete_elem = reuseport_array_delete_elem,
+	.map_btf_name = "reuseport_array",
+	.map_btf_id = &reuseport_array_map_btf_id,
 };
diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c
new file mode 100644
index 0000000..1e4bf23
--- /dev/null
+++ b/kernel/bpf/ringbuf.c
@@ -0,0 +1,496 @@
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/err.h>
+#include <linux/irq_work.h>
+#include <linux/slab.h>
+#include <linux/filter.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <linux/poll.h>
+#include <linux/kmemleak.h>
+#include <uapi/linux/btf.h>
+
+#define RINGBUF_CREATE_FLAG_MASK (BPF_F_NUMA_NODE)
+
+/* non-mmap()'able part of bpf_ringbuf (everything up to consumer page) */
+#define RINGBUF_PGOFF \
+	(offsetof(struct bpf_ringbuf, consumer_pos) >> PAGE_SHIFT)
+/* consumer page and producer page */
+#define RINGBUF_POS_PAGES 2
+
+#define RINGBUF_MAX_RECORD_SZ (UINT_MAX/4)
+
+/* Maximum size of ring buffer area is limited by 32-bit page offset within
+ * record header, counted in pages. Reserve 8 bits for extensibility, and take
+ * into account few extra pages for consumer/producer pages and
+ * non-mmap()'able parts. This gives 64GB limit, which seems plenty for single
+ * ring buffer.
+ */
+#define RINGBUF_MAX_DATA_SZ \
+	(((1ULL << 24) - RINGBUF_POS_PAGES - RINGBUF_PGOFF) * PAGE_SIZE)
+
+struct bpf_ringbuf {
+	wait_queue_head_t waitq;
+	struct irq_work work;
+	u64 mask;
+	struct page **pages;
+	int nr_pages;
+	spinlock_t spinlock ____cacheline_aligned_in_smp;
+	/* Consumer and producer counters are put into separate pages to allow
+	 * mapping consumer page as r/w, but restrict producer page to r/o.
+	 * This protects producer position from being modified by user-space
+	 * application and ruining in-kernel position tracking.
+	 */
+	unsigned long consumer_pos __aligned(PAGE_SIZE);
+	unsigned long producer_pos __aligned(PAGE_SIZE);
+	char data[] __aligned(PAGE_SIZE);
+};
+
+struct bpf_ringbuf_map {
+	struct bpf_map map;
+	struct bpf_map_memory memory;
+	struct bpf_ringbuf *rb;
+};
+
+/* 8-byte ring buffer record header structure */
+struct bpf_ringbuf_hdr {
+	u32 len;
+	u32 pg_off;
+};
+
+static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node)
+{
+	const gfp_t flags = GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN |
+			    __GFP_ZERO;
+	int nr_meta_pages = RINGBUF_PGOFF + RINGBUF_POS_PAGES;
+	int nr_data_pages = data_sz >> PAGE_SHIFT;
+	int nr_pages = nr_meta_pages + nr_data_pages;
+	struct page **pages, *page;
+	struct bpf_ringbuf *rb;
+	size_t array_size;
+	int i;
+
+	/* Each data page is mapped twice to allow "virtual"
+	 * continuous read of samples wrapping around the end of ring
+	 * buffer area:
+	 * ------------------------------------------------------
+	 * | meta pages |  real data pages  |  same data pages  |
+	 * ------------------------------------------------------
+	 * |            | 1 2 3 4 5 6 7 8 9 | 1 2 3 4 5 6 7 8 9 |
+	 * ------------------------------------------------------
+	 * |            | TA             DA | TA             DA |
+	 * ------------------------------------------------------
+	 *                               ^^^^^^^
+	 *                                  |
+	 * Here, no need to worry about special handling of wrapped-around
+	 * data due to double-mapped data pages. This works both in kernel and
+	 * when mmap()'ed in user-space, simplifying both kernel and
+	 * user-space implementations significantly.
+	 */
+	array_size = (nr_meta_pages + 2 * nr_data_pages) * sizeof(*pages);
+	if (array_size > PAGE_SIZE)
+		pages = vmalloc_node(array_size, numa_node);
+	else
+		pages = kmalloc_node(array_size, flags, numa_node);
+	if (!pages)
+		return NULL;
+
+	for (i = 0; i < nr_pages; i++) {
+		page = alloc_pages_node(numa_node, flags, 0);
+		if (!page) {
+			nr_pages = i;
+			goto err_free_pages;
+		}
+		pages[i] = page;
+		if (i >= nr_meta_pages)
+			pages[nr_data_pages + i] = page;
+	}
+
+	rb = vmap(pages, nr_meta_pages + 2 * nr_data_pages,
+		  VM_MAP | VM_USERMAP, PAGE_KERNEL);
+	if (rb) {
+		kmemleak_not_leak(pages);
+		rb->pages = pages;
+		rb->nr_pages = nr_pages;
+		return rb;
+	}
+
+err_free_pages:
+	for (i = 0; i < nr_pages; i++)
+		__free_page(pages[i]);
+	kvfree(pages);
+	return NULL;
+}
+
+static void bpf_ringbuf_notify(struct irq_work *work)
+{
+	struct bpf_ringbuf *rb = container_of(work, struct bpf_ringbuf, work);
+
+	wake_up_all(&rb->waitq);
+}
+
+static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
+{
+	struct bpf_ringbuf *rb;
+
+	rb = bpf_ringbuf_area_alloc(data_sz, numa_node);
+	if (!rb)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&rb->spinlock);
+	init_waitqueue_head(&rb->waitq);
+	init_irq_work(&rb->work, bpf_ringbuf_notify);
+
+	rb->mask = data_sz - 1;
+	rb->consumer_pos = 0;
+	rb->producer_pos = 0;
+
+	return rb;
+}
+
+static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_ringbuf_map *rb_map;
+	u64 cost;
+	int err;
+
+	if (attr->map_flags & ~RINGBUF_CREATE_FLAG_MASK)
+		return ERR_PTR(-EINVAL);
+
+	if (attr->key_size || attr->value_size ||
+	    !is_power_of_2(attr->max_entries) ||
+	    !PAGE_ALIGNED(attr->max_entries))
+		return ERR_PTR(-EINVAL);
+
+#ifdef CONFIG_64BIT
+	/* on 32-bit arch, it's impossible to overflow record's hdr->pgoff */
+	if (attr->max_entries > RINGBUF_MAX_DATA_SZ)
+		return ERR_PTR(-E2BIG);
+#endif
+
+	rb_map = kzalloc(sizeof(*rb_map), GFP_USER);
+	if (!rb_map)
+		return ERR_PTR(-ENOMEM);
+
+	bpf_map_init_from_attr(&rb_map->map, attr);
+
+	cost = sizeof(struct bpf_ringbuf_map) +
+	       sizeof(struct bpf_ringbuf) +
+	       attr->max_entries;
+	err = bpf_map_charge_init(&rb_map->map.memory, cost);
+	if (err)
+		goto err_free_map;
+
+	rb_map->rb = bpf_ringbuf_alloc(attr->max_entries, rb_map->map.numa_node);
+	if (IS_ERR(rb_map->rb)) {
+		err = PTR_ERR(rb_map->rb);
+		goto err_uncharge;
+	}
+
+	return &rb_map->map;
+
+err_uncharge:
+	bpf_map_charge_finish(&rb_map->map.memory);
+err_free_map:
+	kfree(rb_map);
+	return ERR_PTR(err);
+}
+
+static void bpf_ringbuf_free(struct bpf_ringbuf *rb)
+{
+	/* copy pages pointer and nr_pages to local variable, as we are going
+	 * to unmap rb itself with vunmap() below
+	 */
+	struct page **pages = rb->pages;
+	int i, nr_pages = rb->nr_pages;
+
+	vunmap(rb);
+	for (i = 0; i < nr_pages; i++)
+		__free_page(pages[i]);
+	kvfree(pages);
+}
+
+static void ringbuf_map_free(struct bpf_map *map)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	bpf_ringbuf_free(rb_map->rb);
+	kfree(rb_map);
+}
+
+static void *ringbuf_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
+
+static int ringbuf_map_update_elem(struct bpf_map *map, void *key, void *value,
+				   u64 flags)
+{
+	return -ENOTSUPP;
+}
+
+static int ringbuf_map_delete_elem(struct bpf_map *map, void *key)
+{
+	return -ENOTSUPP;
+}
+
+static int ringbuf_map_get_next_key(struct bpf_map *map, void *key,
+				    void *next_key)
+{
+	return -ENOTSUPP;
+}
+
+static int ringbuf_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+
+	if (vma->vm_flags & VM_WRITE) {
+		/* allow writable mapping for the consumer_pos only */
+		if (vma->vm_pgoff != 0 || vma->vm_end - vma->vm_start != PAGE_SIZE)
+			return -EPERM;
+	} else {
+		vma->vm_flags &= ~VM_MAYWRITE;
+	}
+	/* remap_vmalloc_range() checks size and offset constraints */
+	return remap_vmalloc_range(vma, rb_map->rb,
+				   vma->vm_pgoff + RINGBUF_PGOFF);
+}
+
+static unsigned long ringbuf_avail_data_sz(struct bpf_ringbuf *rb)
+{
+	unsigned long cons_pos, prod_pos;
+
+	cons_pos = smp_load_acquire(&rb->consumer_pos);
+	prod_pos = smp_load_acquire(&rb->producer_pos);
+	return prod_pos - cons_pos;
+}
+
+static __poll_t ringbuf_map_poll(struct bpf_map *map, struct file *filp,
+				 struct poll_table_struct *pts)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	poll_wait(filp, &rb_map->rb->waitq, pts);
+
+	if (ringbuf_avail_data_sz(rb_map->rb))
+		return EPOLLIN | EPOLLRDNORM;
+	return 0;
+}
+
+static int ringbuf_map_btf_id;
+const struct bpf_map_ops ringbuf_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc = ringbuf_map_alloc,
+	.map_free = ringbuf_map_free,
+	.map_mmap = ringbuf_map_mmap,
+	.map_poll = ringbuf_map_poll,
+	.map_lookup_elem = ringbuf_map_lookup_elem,
+	.map_update_elem = ringbuf_map_update_elem,
+	.map_delete_elem = ringbuf_map_delete_elem,
+	.map_get_next_key = ringbuf_map_get_next_key,
+	.map_btf_name = "bpf_ringbuf_map",
+	.map_btf_id = &ringbuf_map_btf_id,
+};
+
+/* Given pointer to ring buffer record metadata and struct bpf_ringbuf itself,
+ * calculate offset from record metadata to ring buffer in pages, rounded
+ * down. This page offset is stored as part of record metadata and allows to
+ * restore struct bpf_ringbuf * from record pointer. This page offset is
+ * stored at offset 4 of record metadata header.
+ */
+static size_t bpf_ringbuf_rec_pg_off(struct bpf_ringbuf *rb,
+				     struct bpf_ringbuf_hdr *hdr)
+{
+	return ((void *)hdr - (void *)rb) >> PAGE_SHIFT;
+}
+
+/* Given pointer to ring buffer record header, restore pointer to struct
+ * bpf_ringbuf itself by using page offset stored at offset 4
+ */
+static struct bpf_ringbuf *
+bpf_ringbuf_restore_from_rec(struct bpf_ringbuf_hdr *hdr)
+{
+	unsigned long addr = (unsigned long)(void *)hdr;
+	unsigned long off = (unsigned long)hdr->pg_off << PAGE_SHIFT;
+
+	return (void*)((addr & PAGE_MASK) - off);
+}
+
+static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)
+{
+	unsigned long cons_pos, prod_pos, new_prod_pos, flags;
+	u32 len, pg_off;
+	struct bpf_ringbuf_hdr *hdr;
+
+	if (unlikely(size > RINGBUF_MAX_RECORD_SZ))
+		return NULL;
+
+	len = round_up(size + BPF_RINGBUF_HDR_SZ, 8);
+	if (len > rb->mask + 1)
+		return NULL;
+
+	cons_pos = smp_load_acquire(&rb->consumer_pos);
+
+	if (in_nmi()) {
+		if (!spin_trylock_irqsave(&rb->spinlock, flags))
+			return NULL;
+	} else {
+		spin_lock_irqsave(&rb->spinlock, flags);
+	}
+
+	prod_pos = rb->producer_pos;
+	new_prod_pos = prod_pos + len;
+
+	/* check for out of ringbuf space by ensuring producer position
+	 * doesn't advance more than (ringbuf_size - 1) ahead
+	 */
+	if (new_prod_pos - cons_pos > rb->mask) {
+		spin_unlock_irqrestore(&rb->spinlock, flags);
+		return NULL;
+	}
+
+	hdr = (void *)rb->data + (prod_pos & rb->mask);
+	pg_off = bpf_ringbuf_rec_pg_off(rb, hdr);
+	hdr->len = size | BPF_RINGBUF_BUSY_BIT;
+	hdr->pg_off = pg_off;
+
+	/* pairs with consumer's smp_load_acquire() */
+	smp_store_release(&rb->producer_pos, new_prod_pos);
+
+	spin_unlock_irqrestore(&rb->spinlock, flags);
+
+	return (void *)hdr + BPF_RINGBUF_HDR_SZ;
+}
+
+BPF_CALL_3(bpf_ringbuf_reserve, struct bpf_map *, map, u64, size, u64, flags)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	if (unlikely(flags))
+		return 0;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	return (unsigned long)__bpf_ringbuf_reserve(rb_map->rb, size);
+}
+
+const struct bpf_func_proto bpf_ringbuf_reserve_proto = {
+	.func		= bpf_ringbuf_reserve,
+	.ret_type	= RET_PTR_TO_ALLOC_MEM_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_CONST_ALLOC_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+static void bpf_ringbuf_commit(void *sample, u64 flags, bool discard)
+{
+	unsigned long rec_pos, cons_pos;
+	struct bpf_ringbuf_hdr *hdr;
+	struct bpf_ringbuf *rb;
+	u32 new_len;
+
+	hdr = sample - BPF_RINGBUF_HDR_SZ;
+	rb = bpf_ringbuf_restore_from_rec(hdr);
+	new_len = hdr->len ^ BPF_RINGBUF_BUSY_BIT;
+	if (discard)
+		new_len |= BPF_RINGBUF_DISCARD_BIT;
+
+	/* update record header with correct final size prefix */
+	xchg(&hdr->len, new_len);
+
+	/* if consumer caught up and is waiting for our record, notify about
+	 * new data availability
+	 */
+	rec_pos = (void *)hdr - (void *)rb->data;
+	cons_pos = smp_load_acquire(&rb->consumer_pos) & rb->mask;
+
+	if (flags & BPF_RB_FORCE_WAKEUP)
+		irq_work_queue(&rb->work);
+	else if (cons_pos == rec_pos && !(flags & BPF_RB_NO_WAKEUP))
+		irq_work_queue(&rb->work);
+}
+
+BPF_CALL_2(bpf_ringbuf_submit, void *, sample, u64, flags)
+{
+	bpf_ringbuf_commit(sample, flags, false /* discard */);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_ringbuf_submit_proto = {
+	.func		= bpf_ringbuf_submit,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_ALLOC_MEM,
+	.arg2_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_ringbuf_discard, void *, sample, u64, flags)
+{
+	bpf_ringbuf_commit(sample, flags, true /* discard */);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_ringbuf_discard_proto = {
+	.func		= bpf_ringbuf_discard,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_ALLOC_MEM,
+	.arg2_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_4(bpf_ringbuf_output, struct bpf_map *, map, void *, data, u64, size,
+	   u64, flags)
+{
+	struct bpf_ringbuf_map *rb_map;
+	void *rec;
+
+	if (unlikely(flags & ~(BPF_RB_NO_WAKEUP | BPF_RB_FORCE_WAKEUP)))
+		return -EINVAL;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	rec = __bpf_ringbuf_reserve(rb_map->rb, size);
+	if (!rec)
+		return -EAGAIN;
+
+	memcpy(rec, data, size);
+	bpf_ringbuf_commit(rec, flags, false /* discard */);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_ringbuf_output_proto = {
+	.func		= bpf_ringbuf_output,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_ringbuf_query, struct bpf_map *, map, u64, flags)
+{
+	struct bpf_ringbuf *rb;
+
+	rb = container_of(map, struct bpf_ringbuf_map, map)->rb;
+
+	switch (flags) {
+	case BPF_RB_AVAIL_DATA:
+		return ringbuf_avail_data_sz(rb);
+	case BPF_RB_RING_SIZE:
+		return rb->mask + 1;
+	case BPF_RB_CONS_POS:
+		return smp_load_acquire(&rb->consumer_pos);
+	case BPF_RB_PROD_POS:
+		return smp_load_acquire(&rb->producer_pos);
+	default:
+		return 0;
+	}
+}
+
+const struct bpf_func_proto bpf_ringbuf_query_proto = {
+	.func		= bpf_ringbuf_query,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_ANYTHING,
+};
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index fba2ade..56cd7e6 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -4,11 +4,13 @@
 #include <linux/bpf.h>
 #include <linux/jhash.h>
 #include <linux/filter.h>
+#include <linux/kernel.h>
 #include <linux/stacktrace.h>
 #include <linux/perf_event.h>
 #include <linux/elf.h>
 #include <linux/pagemap.h>
 #include <linux/irq_work.h>
+#include <linux/btf_ids.h>
 #include "percpu_freelist.h"
 
 #define STACK_CREATE_FLAG_MASK					\
@@ -33,16 +35,18 @@
 /* irq_work to run up_read() for build_id lookup in nmi context */
 struct stack_map_irq_work {
 	struct irq_work irq_work;
-	struct rw_semaphore *sem;
+	struct mm_struct *mm;
 };
 
 static void do_up_read(struct irq_work *entry)
 {
 	struct stack_map_irq_work *work;
 
+	if (WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_RT)))
+		return;
+
 	work = container_of(entry, struct stack_map_irq_work, irq_work);
-	up_read_non_owner(work->sem);
-	work->sem = NULL;
+	mmap_read_unlock_non_owner(work->mm);
 }
 
 static DEFINE_PER_CPU(struct stack_map_irq_work, up_read_work);
@@ -60,7 +64,8 @@
 
 static int prealloc_elems_and_freelist(struct bpf_stack_map *smap)
 {
-	u32 elem_size = sizeof(struct stack_map_bucket) + smap->map.value_size;
+	u64 elem_size = sizeof(struct stack_map_bucket) +
+			(u64)smap->map.value_size;
 	int err;
 
 	smap->elems = bpf_map_area_alloc(elem_size * smap->map.max_entries,
@@ -90,7 +95,7 @@
 	u64 cost, n_buckets;
 	int err;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!bpf_capable())
 		return ERR_PTR(-EPERM);
 
 	if (attr->map_flags & ~STACK_CREATE_FLAG_MASK)
@@ -211,11 +216,13 @@
 
 	phdr = (Elf32_Phdr *)(page_addr + sizeof(Elf32_Ehdr));
 
-	for (i = 0; i < ehdr->e_phnum; ++i)
-		if (phdr[i].p_type == PT_NOTE)
-			return stack_map_parse_build_id(page_addr, build_id,
-					page_addr + phdr[i].p_offset,
-					phdr[i].p_filesz);
+	for (i = 0; i < ehdr->e_phnum; ++i) {
+		if (phdr[i].p_type == PT_NOTE &&
+		    !stack_map_parse_build_id(page_addr, build_id,
+					      page_addr + phdr[i].p_offset,
+					      phdr[i].p_filesz))
+			return 0;
+	}
 	return -EINVAL;
 }
 
@@ -234,11 +241,13 @@
 
 	phdr = (Elf64_Phdr *)(page_addr + sizeof(Elf64_Ehdr));
 
-	for (i = 0; i < ehdr->e_phnum; ++i)
-		if (phdr[i].p_type == PT_NOTE)
-			return stack_map_parse_build_id(page_addr, build_id,
-					page_addr + phdr[i].p_offset,
-					phdr[i].p_filesz);
+	for (i = 0; i < ehdr->e_phnum; ++i) {
+		if (phdr[i].p_type == PT_NOTE &&
+		    !stack_map_parse_build_id(page_addr, build_id,
+					      page_addr + phdr[i].p_offset,
+					      phdr[i].p_filesz))
+			return 0;
+	}
 	return -EINVAL;
 }
 
@@ -290,10 +299,19 @@
 	struct stack_map_irq_work *work = NULL;
 
 	if (irqs_disabled()) {
-		work = this_cpu_ptr(&up_read_work);
-		if (work->irq_work.flags & IRQ_WORK_BUSY)
-			/* cannot queue more up_read, fallback */
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			work = this_cpu_ptr(&up_read_work);
+			if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY) {
+				/* cannot queue more up_read, fallback */
+				irq_work_busy = true;
+			}
+		} else {
+			/*
+			 * PREEMPT_RT does not allow to trylock mmap sem in
+			 * interrupt disabled context. Force the fallback code.
+			 */
 			irq_work_busy = true;
+		}
 	}
 
 	/*
@@ -307,7 +325,7 @@
 	 * with build_id.
 	 */
 	if (!user || !current || !current->mm || irq_work_busy ||
-	    down_read_trylock(&current->mm->mmap_sem) == 0) {
+	    !mmap_read_trylock_non_owner(current->mm)) {
 		/* cannot access current->mm, fall back to ips */
 		for (i = 0; i < trace_nr; i++) {
 			id_offs[i].status = BPF_STACK_BUILD_ID_IP;
@@ -332,24 +350,55 @@
 	}
 
 	if (!work) {
-		up_read(&current->mm->mmap_sem);
+		mmap_read_unlock_non_owner(current->mm);
 	} else {
-		work->sem = &current->mm->mmap_sem;
+		work->mm = current->mm;
 		irq_work_queue(&work->irq_work);
-		/*
-		 * The irq_work will release the mmap_sem with
-		 * up_read_non_owner(). The rwsem_release() is called
-		 * here to release the lock from lockdep's perspective.
-		 */
-		rwsem_release(&current->mm->mmap_sem.dep_map, 1, _RET_IP_);
 	}
 }
 
-BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map,
-	   u64, flags)
+static struct perf_callchain_entry *
+get_callchain_entry_for_task(struct task_struct *task, u32 init_nr)
+{
+#ifdef CONFIG_STACKTRACE
+	struct perf_callchain_entry *entry;
+	int rctx;
+
+	entry = get_callchain_entry(&rctx);
+
+	if (!entry)
+		return NULL;
+
+	entry->nr = init_nr +
+		stack_trace_save_tsk(task, (unsigned long *)(entry->ip + init_nr),
+				     sysctl_perf_event_max_stack - init_nr, 0);
+
+	/* stack_trace_save_tsk() works on unsigned long array, while
+	 * perf_callchain_entry uses u64 array. For 32-bit systems, it is
+	 * necessary to fix this mismatch.
+	 */
+	if (__BITS_PER_LONG != 64) {
+		unsigned long *from = (unsigned long *) entry->ip;
+		u64 *to = entry->ip;
+		int i;
+
+		/* copy data from the end to avoid using extra buffer */
+		for (i = entry->nr - 1; i >= (int)init_nr; i--)
+			to[i] = (u64)(from[i]);
+	}
+
+	put_callchain_entry(rctx);
+
+	return entry;
+#else /* CONFIG_STACKTRACE */
+	return NULL;
+#endif
+}
+
+static long __bpf_get_stackid(struct bpf_map *map,
+			      struct perf_callchain_entry *trace, u64 flags)
 {
 	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
-	struct perf_callchain_entry *trace;
 	struct stack_map_bucket *bucket, *new_bucket, *old_bucket;
 	u32 max_depth = map->value_size / stack_map_data_size(map);
 	/* stack_map_alloc() checks that max_depth <= sysctl_perf_event_max_stack */
@@ -357,21 +406,9 @@
 	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
 	u32 hash, id, trace_nr, trace_len;
 	bool user = flags & BPF_F_USER_STACK;
-	bool kernel = !user;
 	u64 *ips;
 	bool hash_matches;
 
-	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
-			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
-		return -EINVAL;
-
-	trace = get_perf_callchain(regs, init_nr, kernel, user,
-				   sysctl_perf_event_max_stack, false, false);
-
-	if (unlikely(!trace))
-		/* couldn't fetch the stack trace */
-		return -EFAULT;
-
 	/* get_perf_callchain() guarantees that trace->nr >= init_nr
 	 * and trace-nr <= sysctl_perf_event_max_stack, so trace_nr <= max_depth
 	 */
@@ -436,6 +473,30 @@
 	return id;
 }
 
+BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map,
+	   u64, flags)
+{
+	u32 max_depth = map->value_size / stack_map_data_size(map);
+	/* stack_map_alloc() checks that max_depth <= sysctl_perf_event_max_stack */
+	u32 init_nr = sysctl_perf_event_max_stack - max_depth;
+	bool user = flags & BPF_F_USER_STACK;
+	struct perf_callchain_entry *trace;
+	bool kernel = !user;
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
+		return -EINVAL;
+
+	trace = get_perf_callchain(regs, init_nr, kernel, user,
+				   sysctl_perf_event_max_stack, false, false);
+
+	if (unlikely(!trace))
+		/* couldn't fetch the stack trace */
+		return -EFAULT;
+
+	return __bpf_get_stackid(map, trace, flags);
+}
+
 const struct bpf_func_proto bpf_get_stackid_proto = {
 	.func		= bpf_get_stackid,
 	.gpl_only	= true,
@@ -445,8 +506,78 @@
 	.arg3_type	= ARG_ANYTHING,
 };
 
-BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size,
-	   u64, flags)
+static __u64 count_kernel_ip(struct perf_callchain_entry *trace)
+{
+	__u64 nr_kernel = 0;
+
+	while (nr_kernel < trace->nr) {
+		if (trace->ip[nr_kernel] == PERF_CONTEXT_USER)
+			break;
+		nr_kernel++;
+	}
+	return nr_kernel;
+}
+
+BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx,
+	   struct bpf_map *, map, u64, flags)
+{
+	struct perf_event *event = ctx->event;
+	struct perf_callchain_entry *trace;
+	bool kernel, user;
+	__u64 nr_kernel;
+	int ret;
+
+	/* perf_sample_data doesn't have callchain, use bpf_get_stackid */
+	if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
+		return bpf_get_stackid((unsigned long)(ctx->regs),
+				       (unsigned long) map, flags, 0, 0);
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
+		return -EINVAL;
+
+	user = flags & BPF_F_USER_STACK;
+	kernel = !user;
+
+	trace = ctx->data->callchain;
+	if (unlikely(!trace))
+		return -EFAULT;
+
+	nr_kernel = count_kernel_ip(trace);
+
+	if (kernel) {
+		__u64 nr = trace->nr;
+
+		trace->nr = nr_kernel;
+		ret = __bpf_get_stackid(map, trace, flags);
+
+		/* restore nr */
+		trace->nr = nr;
+	} else { /* user */
+		u64 skip = flags & BPF_F_SKIP_FIELD_MASK;
+
+		skip += nr_kernel;
+		if (skip > BPF_F_SKIP_FIELD_MASK)
+			return -EFAULT;
+
+		flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip;
+		ret = __bpf_get_stackid(map, trace, flags);
+	}
+	return ret;
+}
+
+const struct bpf_func_proto bpf_get_stackid_proto_pe = {
+	.func		= bpf_get_stackid_pe,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_CONST_MAP_PTR,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task,
+			    struct perf_callchain_entry *trace_in,
+			    void *buf, u32 size, u64 flags)
 {
 	u32 init_nr, trace_nr, copy_len, elem_size, num_elem;
 	bool user_build_id = flags & BPF_F_USER_BUILD_ID;
@@ -468,13 +599,24 @@
 	if (unlikely(size % elem_size))
 		goto clear;
 
+	/* cannot get valid user stack for task without user_mode regs */
+	if (task && user && !user_mode(regs))
+		goto err_fault;
+
 	num_elem = size / elem_size;
 	if (sysctl_perf_event_max_stack < num_elem)
 		init_nr = 0;
 	else
 		init_nr = sysctl_perf_event_max_stack - num_elem;
-	trace = get_perf_callchain(regs, init_nr, kernel, user,
-				   sysctl_perf_event_max_stack, false, false);
+
+	if (trace_in)
+		trace = trace_in;
+	else if (kernel && task)
+		trace = get_callchain_entry_for_task(task, init_nr);
+	else
+		trace = get_perf_callchain(regs, init_nr, kernel, user,
+					   sysctl_perf_event_max_stack,
+					   false, false);
 	if (unlikely(!trace))
 		goto err_fault;
 
@@ -502,6 +644,12 @@
 	return err;
 }
 
+BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size,
+	   u64, flags)
+{
+	return __bpf_get_stack(regs, NULL, NULL, buf, size, flags);
+}
+
 const struct bpf_func_proto bpf_get_stack_proto = {
 	.func		= bpf_get_stack,
 	.gpl_only	= true,
@@ -512,6 +660,99 @@
 	.arg4_type	= ARG_ANYTHING,
 };
 
+BPF_CALL_4(bpf_get_task_stack, struct task_struct *, task, void *, buf,
+	   u32, size, u64, flags)
+{
+	struct pt_regs *regs;
+	long res = -EINVAL;
+
+	if (!try_get_task_stack(task))
+		return -EFAULT;
+
+	regs = task_pt_regs(task);
+	if (regs)
+		res = __bpf_get_stack(regs, task, NULL, buf, size, flags);
+	put_task_stack(task);
+
+	return res;
+}
+
+BTF_ID_LIST_SINGLE(bpf_get_task_stack_btf_ids, struct, task_struct)
+
+const struct bpf_func_proto bpf_get_task_stack_proto = {
+	.func		= bpf_get_task_stack,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &bpf_get_task_stack_btf_ids[0],
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx,
+	   void *, buf, u32, size, u64, flags)
+{
+	struct pt_regs *regs = (struct pt_regs *)(ctx->regs);
+	struct perf_event *event = ctx->event;
+	struct perf_callchain_entry *trace;
+	bool kernel, user;
+	int err = -EINVAL;
+	__u64 nr_kernel;
+
+	if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
+		return __bpf_get_stack(regs, NULL, NULL, buf, size, flags);
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_USER_BUILD_ID)))
+		goto clear;
+
+	user = flags & BPF_F_USER_STACK;
+	kernel = !user;
+
+	err = -EFAULT;
+	trace = ctx->data->callchain;
+	if (unlikely(!trace))
+		goto clear;
+
+	nr_kernel = count_kernel_ip(trace);
+
+	if (kernel) {
+		__u64 nr = trace->nr;
+
+		trace->nr = nr_kernel;
+		err = __bpf_get_stack(regs, NULL, trace, buf, size, flags);
+
+		/* restore nr */
+		trace->nr = nr;
+	} else { /* user */
+		u64 skip = flags & BPF_F_SKIP_FIELD_MASK;
+
+		skip += nr_kernel;
+		if (skip > BPF_F_SKIP_FIELD_MASK)
+			goto clear;
+
+		flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip;
+		err = __bpf_get_stack(regs, NULL, trace, buf, size, flags);
+	}
+	return err;
+
+clear:
+	memset(buf, 0, size);
+	return err;
+
+}
+
+const struct bpf_func_proto bpf_get_stack_proto_pe = {
+	.func		= bpf_get_stack_pe,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
 /* Called from eBPF program */
 static void *stack_map_lookup_elem(struct bpf_map *map, void *key)
 {
@@ -601,16 +842,15 @@
 {
 	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
 
-	/* wait for bpf programs to complete before freeing stack map */
-	synchronize_rcu();
-
 	bpf_map_area_free(smap->elems);
 	pcpu_freelist_destroy(&smap->freelist);
 	bpf_map_area_free(smap);
 	put_callchain_buffers();
 }
 
+static int stack_trace_map_btf_id;
 const struct bpf_map_ops stack_trace_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc = stack_map_alloc,
 	.map_free = stack_map_free,
 	.map_get_next_key = stack_map_get_next_key,
@@ -618,6 +858,8 @@
 	.map_update_elem = stack_map_update_elem,
 	.map_delete_elem = stack_map_delete_elem,
 	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_stack_map",
+	.map_btf_id = &stack_trace_map_btf_id,
 };
 
 static int __init stack_map_init(void)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index bf03d04..419dbc3 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4,6 +4,7 @@
 #include <linux/bpf.h>
 #include <linux/bpf_trace.h>
 #include <linux/bpf_lirc.h>
+#include <linux/bpf_verifier.h>
 #include <linux/btf.h>
 #include <linux/syscalls.h>
 #include <linux/slab.h>
@@ -23,13 +24,21 @@
 #include <linux/timekeeping.h>
 #include <linux/ctype.h>
 #include <linux/nospec.h>
+#include <linux/audit.h>
+#include <uapi/linux/btf.h>
+#include <linux/pgtable.h>
+#include <linux/bpf_lsm.h>
+#include <linux/poll.h>
+#include <linux/bpf-netns.h>
+#include <linux/rcupdate_trace.h>
 
-#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
-			   (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
-			   (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
-			   (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
+#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
+			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
+			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
+#define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
-#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))
+#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
+			IS_FD_HASH(map))
 
 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
 
@@ -38,16 +47,21 @@
 static DEFINE_SPINLOCK(prog_idr_lock);
 static DEFINE_IDR(map_idr);
 static DEFINE_SPINLOCK(map_idr_lock);
+static DEFINE_IDR(link_idr);
+static DEFINE_SPINLOCK(link_idr_lock);
 
-int sysctl_unprivileged_bpf_disabled __read_mostly;
+int sysctl_unprivileged_bpf_disabled __read_mostly =
+	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
 
 static const struct bpf_map_ops * const bpf_map_types[] = {
-#define BPF_PROG_TYPE(_id, _ops)
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
 #define BPF_MAP_TYPE(_id, _ops) \
 	[_id] = &_ops,
+#define BPF_LINK_TYPE(_id, _name)
 #include <linux/bpf_types.h>
 #undef BPF_PROG_TYPE
 #undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
 };
 
 /*
@@ -63,35 +77,23 @@
 			     size_t expected_size,
 			     size_t actual_size)
 {
-	unsigned char __user *addr;
-	unsigned char __user *end;
-	unsigned char val;
-	int err;
+	unsigned char __user *addr = uaddr + expected_size;
+	int res;
 
 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
 		return -E2BIG;
 
-	if (unlikely(!access_ok(uaddr, actual_size)))
-		return -EFAULT;
-
 	if (actual_size <= expected_size)
 		return 0;
 
-	addr = uaddr + expected_size;
-	end  = uaddr + actual_size;
-
-	for (; addr < end; addr++) {
-		err = get_user(val, addr);
-		if (err)
-			return err;
-		if (val)
-			return -E2BIG;
-	}
-
-	return 0;
+	res = check_zeroed_user(addr, actual_size - expected_size);
+	if (res < 0)
+		return res;
+	return res ? 0 : -E2BIG;
 }
 
 const struct bpf_map_ops bpf_map_offload_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
 	.map_alloc = bpf_map_offload_map_alloc,
 	.map_free = bpf_map_offload_map_free,
 	.map_check_btf = map_check_no_btf,
@@ -126,7 +128,162 @@
 	return map;
 }
 
-void *bpf_map_area_alloc(u64 size, int numa_node)
+static void bpf_map_write_active_inc(struct bpf_map *map)
+{
+	atomic64_inc(&map->writecnt);
+}
+
+static void bpf_map_write_active_dec(struct bpf_map *map)
+{
+	atomic64_dec(&map->writecnt);
+}
+
+bool bpf_map_write_active(const struct bpf_map *map)
+{
+	return atomic64_read(&map->writecnt) != 0;
+}
+
+static u32 bpf_map_value_size(struct bpf_map *map)
+{
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
+		return round_up(map->value_size, 8) * num_possible_cpus();
+	else if (IS_FD_MAP(map))
+		return sizeof(u32);
+	else
+		return  map->value_size;
+}
+
+static void maybe_wait_bpf_programs(struct bpf_map *map)
+{
+	/* Wait for any running BPF programs to complete so that
+	 * userspace, when we return to it, knows that all programs
+	 * that could be running use the new map value.
+	 */
+	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
+	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
+		synchronize_rcu();
+}
+
+static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
+				void *value, __u64 flags)
+{
+	int err;
+
+	/* Need to create a kthread, thus must support schedule */
+	if (bpf_map_is_dev_bound(map)) {
+		return bpf_map_offload_update_elem(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
+		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		return map->ops->map_update_elem(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
+		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+		return sock_map_update_elem_sys(map, key, value, flags);
+	} else if (IS_FD_PROG_ARRAY(map)) {
+		return bpf_fd_array_map_update_elem(map, f.file, key, value,
+						    flags);
+	}
+
+	bpf_disable_instrumentation();
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+		err = bpf_percpu_hash_update(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		err = bpf_percpu_array_update(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
+		err = bpf_percpu_cgroup_storage_update(map, key, value,
+						       flags);
+	} else if (IS_FD_ARRAY(map)) {
+		rcu_read_lock();
+		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
+						   flags);
+		rcu_read_unlock();
+	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+		rcu_read_lock();
+		err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
+						  flags);
+		rcu_read_unlock();
+	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
+		/* rcu_read_lock() is not needed */
+		err = bpf_fd_reuseport_array_update_elem(map, key, value,
+							 flags);
+	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
+		   map->map_type == BPF_MAP_TYPE_STACK) {
+		err = map->ops->map_push_elem(map, value, flags);
+	} else {
+		rcu_read_lock();
+		err = map->ops->map_update_elem(map, key, value, flags);
+		rcu_read_unlock();
+	}
+	bpf_enable_instrumentation();
+	maybe_wait_bpf_programs(map);
+
+	return err;
+}
+
+static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
+			      __u64 flags)
+{
+	void *ptr;
+	int err;
+
+	if (bpf_map_is_dev_bound(map))
+		return bpf_map_offload_lookup_elem(map, key, value);
+
+	bpf_disable_instrumentation();
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+		err = bpf_percpu_hash_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		err = bpf_percpu_array_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
+		err = bpf_percpu_cgroup_storage_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
+		err = bpf_stackmap_copy(map, key, value);
+	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
+		err = bpf_fd_array_map_lookup_elem(map, key, value);
+	} else if (IS_FD_HASH(map)) {
+		err = bpf_fd_htab_map_lookup_elem(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
+		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
+		   map->map_type == BPF_MAP_TYPE_STACK) {
+		err = map->ops->map_peek_elem(map, value);
+	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		/* struct_ops map requires directly updating "value" */
+		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
+	} else {
+		rcu_read_lock();
+		if (map->ops->map_lookup_elem_sys_only)
+			ptr = map->ops->map_lookup_elem_sys_only(map, key);
+		else
+			ptr = map->ops->map_lookup_elem(map, key);
+		if (IS_ERR(ptr)) {
+			err = PTR_ERR(ptr);
+		} else if (!ptr) {
+			err = -ENOENT;
+		} else {
+			err = 0;
+			if (flags & BPF_F_LOCK)
+				/* lock 'ptr' and copy everything but lock */
+				copy_map_value_locked(map, value, ptr, true);
+			else
+				copy_map_value(map, value, ptr);
+			/* mask lock, since value wasn't zero inited */
+			check_and_init_map_lock(map, value);
+		}
+		rcu_read_unlock();
+	}
+
+	bpf_enable_instrumentation();
+	maybe_wait_bpf_programs(map);
+
+	return err;
+}
+
+static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
 {
 	/* We really just want to fail instead of triggering OOM killer
 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
@@ -138,22 +295,39 @@
 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
 	 */
 
-	const gfp_t flags = __GFP_NOWARN | __GFP_ZERO;
+	const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO;
+	unsigned int flags = 0;
+	unsigned long align = 1;
 	void *area;
 
 	if (size >= SIZE_MAX)
 		return NULL;
 
-	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
-		area = kmalloc_node(size, GFP_USER | __GFP_NORETRY | flags,
+	/* kmalloc()'ed memory can't be mmap()'ed */
+	if (mmapable) {
+		BUG_ON(!PAGE_ALIGNED(size));
+		align = SHMLBA;
+		flags = VM_USERMAP;
+	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
+		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
 				    numa_node);
 		if (area != NULL)
 			return area;
 	}
 
-	return __vmalloc_node_flags_caller(size, numa_node,
-					   GFP_KERNEL | __GFP_RETRY_MAYFAIL |
-					   flags, __builtin_return_address(0));
+	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
+			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
+			flags, numa_node, __builtin_return_address(0));
+}
+
+void *bpf_map_area_alloc(u64 size, int numa_node)
+{
+	return __bpf_map_area_alloc(size, numa_node, false);
+}
+
+void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
+{
+	return __bpf_map_area_alloc(size, numa_node, true);
 }
 
 void bpf_map_area_free(void *area)
@@ -313,7 +487,7 @@
 
 static void bpf_map_put_uref(struct bpf_map *map)
 {
-	if (atomic_dec_and_test(&map->usercnt)) {
+	if (atomic64_dec_and_test(&map->usercnt)) {
 		if (map->ops->map_release_uref)
 			map->ops->map_release_uref(map);
 	}
@@ -324,7 +498,7 @@
  */
 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
 {
-	if (atomic_dec_and_test(&map->refcnt)) {
+	if (atomic64_dec_and_test(&map->refcnt)) {
 		/* bpf_map_free_id() must be called first */
 		bpf_map_free_id(map, do_idr_lock);
 		btf_put(map->btf);
@@ -373,13 +547,14 @@
 {
 	const struct bpf_map *map = filp->private_data;
 	const struct bpf_array *array;
-	u32 owner_prog_type = 0;
-	u32 owner_jited = 0;
+	u32 type = 0, jited = 0;
 
 	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
 		array = container_of(map, struct bpf_array, map);
-		owner_prog_type = array->owner_prog_type;
-		owner_jited = array->owner_jited;
+		spin_lock(&array->aux->owner.lock);
+		type  = array->aux->owner.type;
+		jited = array->aux->owner.jited;
+		spin_unlock(&array->aux->owner.lock);
 	}
 
 	seq_printf(m,
@@ -399,12 +574,9 @@
 		   map->memory.pages * 1ULL << PAGE_SHIFT,
 		   map->id,
 		   READ_ONCE(map->frozen));
-
-	if (owner_prog_type) {
-		seq_printf(m, "owner_prog_type:\t%u\n",
-			   owner_prog_type);
-		seq_printf(m, "owner_jited:\t%u\n",
-			   owner_jited);
+	if (type) {
+		seq_printf(m, "owner_prog_type:\t%u\n", type);
+		seq_printf(m, "owner_jited:\t%u\n", jited);
 	}
 }
 #endif
@@ -427,6 +599,87 @@
 	return -EINVAL;
 }
 
+/* called for any extra memory-mapped regions (except initial) */
+static void bpf_map_mmap_open(struct vm_area_struct *vma)
+{
+	struct bpf_map *map = vma->vm_file->private_data;
+
+	if (vma->vm_flags & VM_MAYWRITE)
+		bpf_map_write_active_inc(map);
+}
+
+/* called for all unmapped memory region (including initial) */
+static void bpf_map_mmap_close(struct vm_area_struct *vma)
+{
+	struct bpf_map *map = vma->vm_file->private_data;
+
+	if (vma->vm_flags & VM_MAYWRITE)
+		bpf_map_write_active_dec(map);
+}
+
+static const struct vm_operations_struct bpf_map_default_vmops = {
+	.open		= bpf_map_mmap_open,
+	.close		= bpf_map_mmap_close,
+};
+
+static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct bpf_map *map = filp->private_data;
+	int err;
+
+	if (!map->ops->map_mmap || map_value_has_spin_lock(map))
+		return -ENOTSUPP;
+
+	if (!(vma->vm_flags & VM_SHARED))
+		return -EINVAL;
+
+	mutex_lock(&map->freeze_mutex);
+
+	if (vma->vm_flags & VM_WRITE) {
+		if (map->frozen) {
+			err = -EPERM;
+			goto out;
+		}
+		/* map is meant to be read-only, so do not allow mapping as
+		 * writable, because it's possible to leak a writable page
+		 * reference and allows user-space to still modify it after
+		 * freezing, while verifier will assume contents do not change
+		 */
+		if (map->map_flags & BPF_F_RDONLY_PROG) {
+			err = -EACCES;
+			goto out;
+		}
+	}
+
+	/* set default open/close callbacks */
+	vma->vm_ops = &bpf_map_default_vmops;
+	vma->vm_private_data = map;
+	vma->vm_flags &= ~VM_MAYEXEC;
+	if (!(vma->vm_flags & VM_WRITE))
+		/* disallow re-mapping with PROT_WRITE */
+		vma->vm_flags &= ~VM_MAYWRITE;
+
+	err = map->ops->map_mmap(map, vma);
+	if (err)
+		goto out;
+
+	if (vma->vm_flags & VM_MAYWRITE)
+		bpf_map_write_active_inc(map);
+out:
+	mutex_unlock(&map->freeze_mutex);
+	return err;
+}
+
+static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
+{
+	struct bpf_map *map = filp->private_data;
+
+	if (map->ops->map_poll)
+		return map->ops->map_poll(map, filp, pts);
+
+	return EPOLLERR;
+}
+
 const struct file_operations bpf_map_fops = {
 #ifdef CONFIG_PROC_FS
 	.show_fdinfo	= bpf_map_show_fdinfo,
@@ -434,6 +687,8 @@
 	.release	= bpf_map_release,
 	.read		= bpf_dummy_read,
 	.write		= bpf_dummy_write,
+	.mmap		= bpf_map_mmap,
+	.poll		= bpf_map_poll,
 };
 
 int bpf_map_new_fd(struct bpf_map *map, int flags)
@@ -467,14 +722,15 @@
 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
 
-/* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes.
- * Return 0 on success and < 0 on error.
+/* dst and src must have at least "size" number of bytes.
+ * Return strlen on success and < 0 on error.
  */
-static int bpf_obj_name_cpy(char *dst, const char *src)
+int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
 {
-	const char *end = src + BPF_OBJ_NAME_LEN;
+	const char *end = src + size;
+	const char *orig_src = src;
 
-	memset(dst, 0, BPF_OBJ_NAME_LEN);
+	memset(dst, 0, size);
 	/* Copy all isalnum(), '_' and '.' chars. */
 	while (src < end && *src) {
 		if (!isalnum(*src) &&
@@ -483,11 +739,11 @@
 		*dst++ = *src++;
 	}
 
-	/* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */
+	/* No '\0' found in "size" number of bytes */
 	if (src == end)
 		return -EINVAL;
 
-	return 0;
+	return src - orig_src;
 }
 
 int map_check_no_btf(const struct bpf_map *map,
@@ -528,7 +784,8 @@
 		if (map->map_type != BPF_MAP_TYPE_HASH &&
 		    map->map_type != BPF_MAP_TYPE_ARRAY &&
 		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
-		    map->map_type != BPF_MAP_TYPE_SK_STORAGE)
+		    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
+		    map->map_type != BPF_MAP_TYPE_INODE_STORAGE)
 			return -ENOTSUPP;
 		if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
 		    map->value_size) {
@@ -545,7 +802,7 @@
 	return ret;
 }
 
-#define BPF_MAP_CREATE_LAST_FIELD btf_value_type_id
+#define BPF_MAP_CREATE_LAST_FIELD btf_vmlinux_value_type_id
 /* called via syscall */
 static int map_create(union bpf_attr *attr)
 {
@@ -559,6 +816,14 @@
 	if (err)
 		return -EINVAL;
 
+	if (attr->btf_vmlinux_value_type_id) {
+		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
+		    attr->btf_key_type_id || attr->btf_value_type_id)
+			return -EINVAL;
+	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
+		return -EINVAL;
+	}
+
 	f_flags = bpf_get_file_flag(attr->map_flags);
 	if (f_flags < 0)
 		return f_flags;
@@ -573,39 +838,44 @@
 	if (IS_ERR(map))
 		return PTR_ERR(map);
 
-	err = bpf_obj_name_cpy(map->name, attr->map_name);
-	if (err)
+	err = bpf_obj_name_cpy(map->name, attr->map_name,
+			       sizeof(attr->map_name));
+	if (err < 0)
 		goto free_map;
 
-	atomic_set(&map->refcnt, 1);
-	atomic_set(&map->usercnt, 1);
+	atomic64_set(&map->refcnt, 1);
+	atomic64_set(&map->usercnt, 1);
+	mutex_init(&map->freeze_mutex);
 
-	if (attr->btf_key_type_id || attr->btf_value_type_id) {
+	map->spin_lock_off = -EINVAL;
+	if (attr->btf_key_type_id || attr->btf_value_type_id ||
+	    /* Even the map's value is a kernel's struct,
+	     * the bpf_prog.o must have BTF to begin with
+	     * to figure out the corresponding kernel's
+	     * counter part.  Thus, attr->btf_fd has
+	     * to be valid also.
+	     */
+	    attr->btf_vmlinux_value_type_id) {
 		struct btf *btf;
 
-		if (!attr->btf_value_type_id) {
-			err = -EINVAL;
-			goto free_map;
-		}
-
 		btf = btf_get_by_fd(attr->btf_fd);
 		if (IS_ERR(btf)) {
 			err = PTR_ERR(btf);
 			goto free_map;
 		}
+		map->btf = btf;
 
-		err = map_check_btf(map, btf, attr->btf_key_type_id,
-				    attr->btf_value_type_id);
-		if (err) {
-			btf_put(btf);
-			goto free_map;
+		if (attr->btf_value_type_id) {
+			err = map_check_btf(map, btf, attr->btf_key_type_id,
+					    attr->btf_value_type_id);
+			if (err)
+				goto free_map;
 		}
 
-		map->btf = btf;
 		map->btf_key_type_id = attr->btf_key_type_id;
 		map->btf_value_type_id = attr->btf_value_type_id;
-	} else {
-		map->spin_lock_off = -EINVAL;
+		map->btf_vmlinux_value_type_id =
+			attr->btf_vmlinux_value_type_id;
 	}
 
 	err = security_bpf_map_alloc(map);
@@ -655,21 +925,34 @@
 	return f.file->private_data;
 }
 
-/* prog's and map's refcnt limit */
-#define BPF_MAX_REFCNT 32768
-
-struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
+void bpf_map_inc(struct bpf_map *map)
 {
-	if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
-		atomic_dec(&map->refcnt);
-		return ERR_PTR(-EBUSY);
-	}
-	if (uref)
-		atomic_inc(&map->usercnt);
-	return map;
+	atomic64_inc(&map->refcnt);
 }
 EXPORT_SYMBOL_GPL(bpf_map_inc);
 
+void bpf_map_inc_with_uref(struct bpf_map *map)
+{
+	atomic64_inc(&map->refcnt);
+	atomic64_inc(&map->usercnt);
+}
+EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
+
+struct bpf_map *bpf_map_get(u32 ufd)
+{
+	struct fd f = fdget(ufd);
+	struct bpf_map *map;
+
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return map;
+
+	bpf_map_inc(map);
+	fdput(f);
+
+	return map;
+}
+
 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
 {
 	struct fd f = fdget(ufd);
@@ -679,38 +962,30 @@
 	if (IS_ERR(map))
 		return map;
 
-	map = bpf_map_inc(map, true);
+	bpf_map_inc_with_uref(map);
 	fdput(f);
 
 	return map;
 }
 
 /* map_idr_lock should have been held */
-static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map,
-					      bool uref)
+static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
 {
 	int refold;
 
-	refold = atomic_fetch_add_unless(&map->refcnt, 1, 0);
-
-	if (refold >= BPF_MAX_REFCNT) {
-		__bpf_map_put(map, false);
-		return ERR_PTR(-EBUSY);
-	}
-
+	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
 	if (!refold)
 		return ERR_PTR(-ENOENT);
-
 	if (uref)
-		atomic_inc(&map->usercnt);
+		atomic64_inc(&map->usercnt);
 
 	return map;
 }
 
-struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
+struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
 {
 	spin_lock_bh(&map_idr_lock);
-	map = __bpf_map_inc_not_zero(map, uref);
+	map = __bpf_map_inc_not_zero(map, false);
 	spin_unlock_bh(&map_idr_lock);
 
 	return map;
@@ -742,7 +1017,7 @@
 	void __user *uvalue = u64_to_user_ptr(attr->value);
 	int ufd = attr->map_fd;
 	struct bpf_map *map;
-	void *key, *value, *ptr;
+	void *key, *value;
 	u32 value_size;
 	struct fd f;
 	int err;
@@ -774,72 +1049,14 @@
 		goto err_put;
 	}
 
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
-	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
-		value_size = round_up(map->value_size, 8) * num_possible_cpus();
-	else if (IS_FD_MAP(map))
-		value_size = sizeof(u32);
-	else
-		value_size = map->value_size;
+	value_size = bpf_map_value_size(map);
 
 	err = -ENOMEM;
 	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
-	if (bpf_map_is_dev_bound(map)) {
-		err = bpf_map_offload_lookup_elem(map, key, value);
-		goto done;
-	}
-
-	preempt_disable();
-	this_cpu_inc(bpf_prog_active);
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
-		err = bpf_percpu_hash_copy(map, key, value);
-	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
-		err = bpf_percpu_array_copy(map, key, value);
-	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
-		err = bpf_percpu_cgroup_storage_copy(map, key, value);
-	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
-		err = bpf_stackmap_copy(map, key, value);
-	} else if (IS_FD_ARRAY(map)) {
-		err = bpf_fd_array_map_lookup_elem(map, key, value);
-	} else if (IS_FD_HASH(map)) {
-		err = bpf_fd_htab_map_lookup_elem(map, key, value);
-	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
-		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
-	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
-		   map->map_type == BPF_MAP_TYPE_STACK) {
-		err = map->ops->map_peek_elem(map, value);
-	} else {
-		rcu_read_lock();
-		if (map->ops->map_lookup_elem_sys_only)
-			ptr = map->ops->map_lookup_elem_sys_only(map, key);
-		else
-			ptr = map->ops->map_lookup_elem(map, key);
-		if (IS_ERR(ptr)) {
-			err = PTR_ERR(ptr);
-		} else if (!ptr) {
-			err = -ENOENT;
-		} else {
-			err = 0;
-			if (attr->flags & BPF_F_LOCK)
-				/* lock 'ptr' and copy everything but lock */
-				copy_map_value_locked(map, value, ptr, true);
-			else
-				copy_map_value(map, value, ptr);
-			/* mask lock, since value wasn't zero inited */
-			check_and_init_map_lock(map, value);
-		}
-		rcu_read_unlock();
-	}
-	this_cpu_dec(bpf_prog_active);
-	preempt_enable();
-
-done:
+	err = bpf_map_copy_value(map, key, value, attr->flags);
 	if (err)
 		goto free_value;
 
@@ -858,16 +1075,6 @@
 	return err;
 }
 
-static void maybe_wait_bpf_programs(struct bpf_map *map)
-{
-	/* Wait for any running BPF programs to complete so that
-	 * userspace, when we return to it, knows that all programs
-	 * that could be running use the new map value.
-	 */
-	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
-	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
-		synchronize_rcu();
-}
 
 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
 
@@ -889,6 +1096,7 @@
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
+	bpf_map_write_active_inc(map);
 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
@@ -923,61 +1131,14 @@
 	if (copy_from_user(value, uvalue, value_size) != 0)
 		goto free_value;
 
-	/* Need to create a kthread, thus must support schedule */
-	if (bpf_map_is_dev_bound(map)) {
-		err = bpf_map_offload_update_elem(map, key, value, attr->flags);
-		goto out;
-	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
-		   map->map_type == BPF_MAP_TYPE_SOCKHASH ||
-		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
-		err = map->ops->map_update_elem(map, key, value, attr->flags);
-		goto out;
-	}
+	err = bpf_map_update_value(map, f, key, value, attr->flags);
 
-	/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
-	 * inside bpf map update or delete otherwise deadlocks are possible
-	 */
-	preempt_disable();
-	__this_cpu_inc(bpf_prog_active);
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
-		err = bpf_percpu_hash_update(map, key, value, attr->flags);
-	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
-		err = bpf_percpu_array_update(map, key, value, attr->flags);
-	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
-		err = bpf_percpu_cgroup_storage_update(map, key, value,
-						       attr->flags);
-	} else if (IS_FD_ARRAY(map)) {
-		rcu_read_lock();
-		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
-						   attr->flags);
-		rcu_read_unlock();
-	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
-		rcu_read_lock();
-		err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
-						  attr->flags);
-		rcu_read_unlock();
-	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
-		/* rcu_read_lock() is not needed */
-		err = bpf_fd_reuseport_array_update_elem(map, key, value,
-							 attr->flags);
-	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
-		   map->map_type == BPF_MAP_TYPE_STACK) {
-		err = map->ops->map_push_elem(map, value, attr->flags);
-	} else {
-		rcu_read_lock();
-		err = map->ops->map_update_elem(map, key, value, attr->flags);
-		rcu_read_unlock();
-	}
-	__this_cpu_dec(bpf_prog_active);
-	preempt_enable();
-	maybe_wait_bpf_programs(map);
-out:
 free_value:
 	kfree(value);
 free_key:
 	kfree(key);
 err_put:
+	bpf_map_write_active_dec(map);
 	fdput(f);
 	return err;
 }
@@ -1000,6 +1161,7 @@
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
+	bpf_map_write_active_inc(map);
 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
@@ -1014,19 +1176,23 @@
 	if (bpf_map_is_dev_bound(map)) {
 		err = bpf_map_offload_delete_elem(map, key);
 		goto out;
+	} else if (IS_FD_PROG_ARRAY(map) ||
+		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		/* These maps require sleepable context */
+		err = map->ops->map_delete_elem(map, key);
+		goto out;
 	}
 
-	preempt_disable();
-	__this_cpu_inc(bpf_prog_active);
+	bpf_disable_instrumentation();
 	rcu_read_lock();
 	err = map->ops->map_delete_elem(map, key);
 	rcu_read_unlock();
-	__this_cpu_dec(bpf_prog_active);
-	preempt_enable();
+	bpf_enable_instrumentation();
 	maybe_wait_bpf_programs(map);
 out:
 	kfree(key);
 err_put:
+	bpf_map_write_active_dec(map);
 	fdput(f);
 	return err;
 }
@@ -1098,6 +1264,222 @@
 	return err;
 }
 
+int generic_map_delete_batch(struct bpf_map *map,
+			     const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	void __user *keys = u64_to_user_ptr(attr->batch.keys);
+	u32 cp, max_count;
+	int err = 0;
+	void *key;
+
+	if (attr->batch.elem_flags & ~BPF_F_LOCK)
+		return -EINVAL;
+
+	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map)) {
+		return -EINVAL;
+	}
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
+	if (!key)
+		return -ENOMEM;
+
+	for (cp = 0; cp < max_count; cp++) {
+		err = -EFAULT;
+		if (copy_from_user(key, keys + cp * map->key_size,
+				   map->key_size))
+			break;
+
+		if (bpf_map_is_dev_bound(map)) {
+			err = bpf_map_offload_delete_elem(map, key);
+			break;
+		}
+
+		bpf_disable_instrumentation();
+		rcu_read_lock();
+		err = map->ops->map_delete_elem(map, key);
+		rcu_read_unlock();
+		bpf_enable_instrumentation();
+		maybe_wait_bpf_programs(map);
+		if (err)
+			break;
+		cond_resched();
+	}
+	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
+		err = -EFAULT;
+
+	kfree(key);
+	return err;
+}
+
+int generic_map_update_batch(struct bpf_map *map,
+			     const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	void __user *values = u64_to_user_ptr(attr->batch.values);
+	void __user *keys = u64_to_user_ptr(attr->batch.keys);
+	u32 value_size, cp, max_count;
+	int ufd = attr->batch.map_fd;
+	void *key, *value;
+	struct fd f;
+	int err = 0;
+
+	if (attr->batch.elem_flags & ~BPF_F_LOCK)
+		return -EINVAL;
+
+	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map)) {
+		return -EINVAL;
+	}
+
+	value_size = bpf_map_value_size(map);
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
+	if (!key)
+		return -ENOMEM;
+
+	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	if (!value) {
+		kfree(key);
+		return -ENOMEM;
+	}
+
+	f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
+	for (cp = 0; cp < max_count; cp++) {
+		err = -EFAULT;
+		if (copy_from_user(key, keys + cp * map->key_size,
+		    map->key_size) ||
+		    copy_from_user(value, values + cp * value_size, value_size))
+			break;
+
+		err = bpf_map_update_value(map, f, key, value,
+					   attr->batch.elem_flags);
+
+		if (err)
+			break;
+		cond_resched();
+	}
+
+	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
+		err = -EFAULT;
+
+	kfree(value);
+	kfree(key);
+	fdput(f);
+	return err;
+}
+
+#define MAP_LOOKUP_RETRIES 3
+
+int generic_map_lookup_batch(struct bpf_map *map,
+				    const union bpf_attr *attr,
+				    union bpf_attr __user *uattr)
+{
+	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
+	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
+	void __user *values = u64_to_user_ptr(attr->batch.values);
+	void __user *keys = u64_to_user_ptr(attr->batch.keys);
+	void *buf, *buf_prevkey, *prev_key, *key, *value;
+	int err, retry = MAP_LOOKUP_RETRIES;
+	u32 value_size, cp, max_count;
+
+	if (attr->batch.elem_flags & ~BPF_F_LOCK)
+		return -EINVAL;
+
+	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map))
+		return -EINVAL;
+
+	value_size = bpf_map_value_size(map);
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
+	buf_prevkey = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
+	if (!buf_prevkey)
+		return -ENOMEM;
+
+	buf = kmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
+	if (!buf) {
+		kfree(buf_prevkey);
+		return -ENOMEM;
+	}
+
+	err = -EFAULT;
+	prev_key = NULL;
+	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
+		goto free_buf;
+	key = buf;
+	value = key + map->key_size;
+	if (ubatch)
+		prev_key = buf_prevkey;
+
+	for (cp = 0; cp < max_count;) {
+		rcu_read_lock();
+		err = map->ops->map_get_next_key(map, prev_key, key);
+		rcu_read_unlock();
+		if (err)
+			break;
+		err = bpf_map_copy_value(map, key, value,
+					 attr->batch.elem_flags);
+
+		if (err == -ENOENT) {
+			if (retry) {
+				retry--;
+				continue;
+			}
+			err = -EINTR;
+			break;
+		}
+
+		if (err)
+			goto free_buf;
+
+		if (copy_to_user(keys + cp * map->key_size, key,
+				 map->key_size)) {
+			err = -EFAULT;
+			goto free_buf;
+		}
+		if (copy_to_user(values + cp * value_size, value, value_size)) {
+			err = -EFAULT;
+			goto free_buf;
+		}
+
+		if (!prev_key)
+			prev_key = buf_prevkey;
+
+		swap(prev_key, key);
+		retry = MAP_LOOKUP_RETRIES;
+		cp++;
+		cond_resched();
+	}
+
+	if (err == -EFAULT)
+		goto free_buf;
+
+	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
+		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
+		err = -EFAULT;
+
+free_buf:
+	kfree(buf_prevkey);
+	kfree(buf);
+	return err;
+}
+
 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD value
 
 static int map_lookup_and_delete_elem(union bpf_attr *attr)
@@ -1118,6 +1500,7 @@
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
+	bpf_map_write_active_inc(map);
 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
@@ -1159,6 +1542,7 @@
 free_key:
 	kfree(key);
 err_put:
+	bpf_map_write_active_dec(map);
 	fdput(f);
 	return err;
 }
@@ -1178,28 +1562,42 @@
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
+
+	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		fdput(f);
+		return -ENOTSUPP;
+	}
+
+	mutex_lock(&map->freeze_mutex);
+	if (bpf_map_write_active(map)) {
+		err = -EBUSY;
+		goto err_put;
+	}
 	if (READ_ONCE(map->frozen)) {
 		err = -EBUSY;
 		goto err_put;
 	}
-	if (!capable(CAP_SYS_ADMIN)) {
+	if (!bpf_capable()) {
 		err = -EPERM;
 		goto err_put;
 	}
 
 	WRITE_ONCE(map->frozen, true);
 err_put:
+	mutex_unlock(&map->freeze_mutex);
 	fdput(f);
 	return err;
 }
 
 static const struct bpf_prog_ops * const bpf_prog_types[] = {
-#define BPF_PROG_TYPE(_id, _name) \
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
 	[_id] = & _name ## _prog_ops,
 #define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name)
 #include <linux/bpf_types.h>
 #undef BPF_PROG_TYPE
 #undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
 };
 
 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
@@ -1221,23 +1619,34 @@
 	return 0;
 }
 
-/* drop refcnt on maps used by eBPF program and free auxilary data */
-static void free_used_maps(struct bpf_prog_aux *aux)
+enum bpf_audit {
+	BPF_AUDIT_LOAD,
+	BPF_AUDIT_UNLOAD,
+	BPF_AUDIT_MAX,
+};
+
+static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
+	[BPF_AUDIT_LOAD]   = "LOAD",
+	[BPF_AUDIT_UNLOAD] = "UNLOAD",
+};
+
+static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
 {
-	enum bpf_cgroup_storage_type stype;
-	int i;
+	struct audit_context *ctx = NULL;
+	struct audit_buffer *ab;
 
-	for_each_cgroup_storage_type(stype) {
-		if (!aux->cgroup_storage[stype])
-			continue;
-		bpf_cgroup_storage_release(aux->prog,
-					   aux->cgroup_storage[stype]);
-	}
-
-	for (i = 0; i < aux->used_map_cnt; i++)
-		bpf_map_put(aux->used_maps[i]);
-
-	kfree(aux->used_maps);
+	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
+		return;
+	if (audit_enabled == AUDIT_OFF)
+		return;
+	if (op == BPF_AUDIT_LOAD)
+		ctx = audit_context();
+	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
+	if (unlikely(!ab))
+		return;
+	audit_log_format(ab, "prog-id=%u op=%s",
+			 prog->aux->id, bpf_audit_str[op]);
+	audit_log_end(ab);
 }
 
 int __bpf_prog_charge(struct user_struct *user, u32 pages)
@@ -1333,7 +1742,7 @@
 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
 
 	kvfree(aux->func_info);
-	free_used_maps(aux);
+	kfree(aux->func_info_aux);
 	bpf_prog_uncharge_memlock(aux->prog);
 	security_bpf_prog_free(aux);
 	bpf_prog_free(aux->prog);
@@ -1345,16 +1754,21 @@
 	btf_put(prog->aux->btf);
 	bpf_prog_free_linfo(prog);
 
-	if (deferred)
-		call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
-	else
+	if (deferred) {
+		if (prog->aux->sleepable)
+			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
+		else
+			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
+	} else {
 		__bpf_prog_put_rcu(&prog->aux->rcu);
+	}
 }
 
 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
 {
-	if (atomic_dec_and_test(&prog->aux->refcnt)) {
+	if (atomic64_dec_and_test(&prog->aux->refcnt)) {
 		perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
+		bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
 		/* bpf_prog_free_id() must be called first */
 		bpf_prog_free_id(prog, do_idr_lock);
 		__bpf_prog_put_noref(prog, true);
@@ -1459,13 +1873,9 @@
 	return f.file->private_data;
 }
 
-struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
+void bpf_prog_add(struct bpf_prog *prog, int i)
 {
-	if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
-		atomic_sub(i, &prog->aux->refcnt);
-		return ERR_PTR(-EBUSY);
-	}
-	return prog;
+	atomic64_add(i, &prog->aux->refcnt);
 }
 EXPORT_SYMBOL_GPL(bpf_prog_add);
 
@@ -1476,13 +1886,13 @@
 	 * path holds a reference to the program, thus atomic_sub() can
 	 * be safely used in such cases!
 	 */
-	WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
+	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
 }
 EXPORT_SYMBOL_GPL(bpf_prog_sub);
 
-struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
+void bpf_prog_inc(struct bpf_prog *prog)
 {
-	return bpf_prog_add(prog, 1);
+	atomic64_inc(&prog->aux->refcnt);
 }
 EXPORT_SYMBOL_GPL(bpf_prog_inc);
 
@@ -1491,12 +1901,7 @@
 {
 	int refold;
 
-	refold = atomic_fetch_add_unless(&prog->aux->refcnt, 1, 0);
-
-	if (refold >= BPF_MAX_REFCNT) {
-		__bpf_prog_put(prog, false);
-		return ERR_PTR(-EBUSY);
-	}
+	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
 
 	if (!refold)
 		return ERR_PTR(-ENOENT);
@@ -1534,7 +1939,7 @@
 		goto out;
 	}
 
-	prog = bpf_prog_inc(prog);
+	bpf_prog_inc(prog);
 out:
 	fdput(f);
 	return prog;
@@ -1579,13 +1984,34 @@
 }
 
 static int
-bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
-				enum bpf_attach_type expected_attach_type)
+bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
+			   enum bpf_attach_type expected_attach_type,
+			   u32 btf_id, u32 prog_fd)
 {
+	if (btf_id) {
+		if (btf_id > BTF_MAX_TYPE)
+			return -EINVAL;
+
+		switch (prog_type) {
+		case BPF_PROG_TYPE_TRACING:
+		case BPF_PROG_TYPE_LSM:
+		case BPF_PROG_TYPE_STRUCT_OPS:
+		case BPF_PROG_TYPE_EXT:
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (prog_fd && prog_type != BPF_PROG_TYPE_TRACING &&
+	    prog_type != BPF_PROG_TYPE_EXT)
+		return -EINVAL;
+
 	switch (prog_type) {
 	case BPF_PROG_TYPE_CGROUP_SOCK:
 		switch (expected_attach_type) {
 		case BPF_CGROUP_INET_SOCK_CREATE:
+		case BPF_CGROUP_INET_SOCK_RELEASE:
 		case BPF_CGROUP_INET4_POST_BIND:
 		case BPF_CGROUP_INET6_POST_BIND:
 			return 0;
@@ -1598,6 +2024,10 @@
 		case BPF_CGROUP_INET6_BIND:
 		case BPF_CGROUP_INET4_CONNECT:
 		case BPF_CGROUP_INET6_CONNECT:
+		case BPF_CGROUP_INET4_GETPEERNAME:
+		case BPF_CGROUP_INET6_GETPEERNAME:
+		case BPF_CGROUP_INET4_GETSOCKNAME:
+		case BPF_CGROUP_INET6_GETSOCKNAME:
 		case BPF_CGROUP_UDP4_SENDMSG:
 		case BPF_CGROUP_UDP6_SENDMSG:
 		case BPF_CGROUP_UDP4_RECVMSG:
@@ -1622,13 +2052,70 @@
 		default:
 			return -EINVAL;
 		}
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		if (expected_attach_type == BPF_SK_LOOKUP)
+			return 0;
+		return -EINVAL;
+	case BPF_PROG_TYPE_EXT:
+		if (expected_attach_type)
+			return -EINVAL;
+		fallthrough;
 	default:
 		return 0;
 	}
 }
 
+static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
+{
+	switch (prog_type) {
+	case BPF_PROG_TYPE_SCHED_CLS:
+	case BPF_PROG_TYPE_SCHED_ACT:
+	case BPF_PROG_TYPE_XDP:
+	case BPF_PROG_TYPE_LWT_IN:
+	case BPF_PROG_TYPE_LWT_OUT:
+	case BPF_PROG_TYPE_LWT_XMIT:
+	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
+	case BPF_PROG_TYPE_SK_SKB:
+	case BPF_PROG_TYPE_SK_MSG:
+	case BPF_PROG_TYPE_LIRC_MODE2:
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_SOCK_OPS:
+	case BPF_PROG_TYPE_EXT: /* extends any prog */
+		return true;
+	case BPF_PROG_TYPE_CGROUP_SKB:
+		/* always unpriv */
+	case BPF_PROG_TYPE_SK_REUSEPORT:
+		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
+	default:
+		return false;
+	}
+}
+
+static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
+{
+	switch (prog_type) {
+	case BPF_PROG_TYPE_KPROBE:
+	case BPF_PROG_TYPE_TRACEPOINT:
+	case BPF_PROG_TYPE_PERF_EVENT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
+	case BPF_PROG_TYPE_TRACING:
+	case BPF_PROG_TYPE_LSM:
+	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
+	case BPF_PROG_TYPE_EXT: /* extends any prog */
+		return true;
+	default:
+		return false;
+	}
+}
+
 /* last field in 'union bpf_attr' used by this command */
-#define	BPF_PROG_LOAD_LAST_FIELD line_info_cnt
+#define	BPF_PROG_LOAD_LAST_FIELD attach_prog_fd
 
 static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
 {
@@ -1644,12 +2131,13 @@
 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
 				 BPF_F_ANY_ALIGNMENT |
 				 BPF_F_TEST_STATE_FREQ |
+				 BPF_F_SLEEPABLE |
 				 BPF_F_TEST_RND_HI32))
 		return -EINVAL;
 
 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
-	    !capable(CAP_SYS_ADMIN))
+	    !bpf_capable())
 		return -EPERM;
 
 	/* copy eBPF program license from user space */
@@ -1662,15 +2150,22 @@
 	is_gpl = license_is_gpl_compatible(license);
 
 	if (attr->insn_cnt == 0 ||
-	    attr->insn_cnt > (capable(CAP_SYS_ADMIN) ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
+	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
 		return -E2BIG;
 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
-	    !capable(CAP_SYS_ADMIN))
+	    !bpf_capable())
+		return -EPERM;
+
+	if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (is_perfmon_prog_type(type) && !perfmon_capable())
 		return -EPERM;
 
 	bpf_prog_load_fixup_attach_type(attr);
-	if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type))
+	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
+				       attr->attach_btf_id,
+				       attr->attach_prog_fd))
 		return -EINVAL;
 
 	/* plain bpf_prog allocation */
@@ -1679,8 +2174,20 @@
 		return -ENOMEM;
 
 	prog->expected_attach_type = attr->expected_attach_type;
+	prog->aux->attach_btf_id = attr->attach_btf_id;
+	if (attr->attach_prog_fd) {
+		struct bpf_prog *dst_prog;
+
+		dst_prog = bpf_prog_get(attr->attach_prog_fd);
+		if (IS_ERR(dst_prog)) {
+			err = PTR_ERR(dst_prog);
+			goto free_prog_nouncharge;
+		}
+		prog->aux->dst_prog = dst_prog;
+	}
 
 	prog->aux->offload_requested = !!attr->prog_ifindex;
+	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
 
 	err = security_bpf_prog_alloc(prog->aux);
 	if (err)
@@ -1700,7 +2207,7 @@
 	prog->orig_prog = NULL;
 	prog->jited = 0;
 
-	atomic_set(&prog->aux->refcnt, 1);
+	atomic64_set(&prog->aux->refcnt, 1);
 	prog->gpl_compatible = is_gpl ? 1 : 0;
 
 	if (bpf_prog_is_dev_bound(prog->aux)) {
@@ -1715,8 +2222,9 @@
 		goto free_prog;
 
 	prog->aux->load_time = ktime_get_boottime_ns();
-	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
-	if (err)
+	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
+			       sizeof(attr->prog_name));
+	if (err < 0)
 		goto free_prog;
 
 	/* run eBPF verifier */
@@ -1748,6 +2256,7 @@
 	 */
 	bpf_prog_kallsyms_add(prog);
 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
+	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
 
 	err = bpf_prog_new_fd(prog);
 	if (err < 0)
@@ -1790,87 +2299,610 @@
 				attr->file_flags);
 }
 
-struct bpf_raw_tracepoint {
-	struct bpf_raw_event_map *btp;
-	struct bpf_prog *prog;
-};
-
-static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp)
+void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
+		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
 {
-	struct bpf_raw_tracepoint *raw_tp = filp->private_data;
+	atomic64_set(&link->refcnt, 1);
+	link->type = type;
+	link->id = 0;
+	link->ops = ops;
+	link->prog = prog;
+}
 
-	if (raw_tp->prog) {
-		bpf_probe_unregister(raw_tp->btp, raw_tp->prog);
-		bpf_prog_put(raw_tp->prog);
+static void bpf_link_free_id(int id)
+{
+	if (!id)
+		return;
+
+	spin_lock_bh(&link_idr_lock);
+	idr_remove(&link_idr, id);
+	spin_unlock_bh(&link_idr_lock);
+}
+
+/* Clean up bpf_link and corresponding anon_inode file and FD. After
+ * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
+ * anon_inode's release() call. This helper marksbpf_link as
+ * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
+ * is not decremented, it's the responsibility of a calling code that failed
+ * to complete bpf_link initialization.
+ */
+void bpf_link_cleanup(struct bpf_link_primer *primer)
+{
+	primer->link->prog = NULL;
+	bpf_link_free_id(primer->id);
+	fput(primer->file);
+	put_unused_fd(primer->fd);
+}
+
+void bpf_link_inc(struct bpf_link *link)
+{
+	atomic64_inc(&link->refcnt);
+}
+
+/* bpf_link_free is guaranteed to be called from process context */
+static void bpf_link_free(struct bpf_link *link)
+{
+	bpf_link_free_id(link->id);
+	if (link->prog) {
+		/* detach BPF program, clean up used resources */
+		link->ops->release(link);
+		bpf_prog_put(link->prog);
 	}
-	bpf_put_raw_tracepoint(raw_tp->btp);
-	kfree(raw_tp);
+	/* free bpf_link and its containing memory */
+	link->ops->dealloc(link);
+}
+
+static void bpf_link_put_deferred(struct work_struct *work)
+{
+	struct bpf_link *link = container_of(work, struct bpf_link, work);
+
+	bpf_link_free(link);
+}
+
+/* bpf_link_put can be called from atomic context, but ensures that resources
+ * are freed from process context
+ */
+void bpf_link_put(struct bpf_link *link)
+{
+	if (!atomic64_dec_and_test(&link->refcnt))
+		return;
+
+	if (in_atomic()) {
+		INIT_WORK(&link->work, bpf_link_put_deferred);
+		schedule_work(&link->work);
+	} else {
+		bpf_link_free(link);
+	}
+}
+
+static int bpf_link_release(struct inode *inode, struct file *filp)
+{
+	struct bpf_link *link = filp->private_data;
+
+	bpf_link_put(link);
 	return 0;
 }
 
-static const struct file_operations bpf_raw_tp_fops = {
-	.release	= bpf_raw_tracepoint_release,
+#ifdef CONFIG_PROC_FS
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
+#define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
+static const char *bpf_link_type_strs[] = {
+	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
+#include <linux/bpf_types.h>
+};
+#undef BPF_PROG_TYPE
+#undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
+
+static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
+{
+	const struct bpf_link *link = filp->private_data;
+	const struct bpf_prog *prog = link->prog;
+	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
+
+	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
+	seq_printf(m,
+		   "link_type:\t%s\n"
+		   "link_id:\t%u\n"
+		   "prog_tag:\t%s\n"
+		   "prog_id:\t%u\n",
+		   bpf_link_type_strs[link->type],
+		   link->id,
+		   prog_tag,
+		   prog->aux->id);
+	if (link->ops->show_fdinfo)
+		link->ops->show_fdinfo(link, m);
+}
+#endif
+
+static const struct file_operations bpf_link_fops = {
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= bpf_link_show_fdinfo,
+#endif
+	.release	= bpf_link_release,
 	.read		= bpf_dummy_read,
 	.write		= bpf_dummy_write,
 };
 
+static int bpf_link_alloc_id(struct bpf_link *link)
+{
+	int id;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock_bh(&link_idr_lock);
+	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
+	spin_unlock_bh(&link_idr_lock);
+	idr_preload_end();
+
+	return id;
+}
+
+/* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
+ * reserving unused FD and allocating ID from link_idr. This is to be paired
+ * with bpf_link_settle() to install FD and ID and expose bpf_link to
+ * user-space, if bpf_link is successfully attached. If not, bpf_link and
+ * pre-allocated resources are to be freed with bpf_cleanup() call. All the
+ * transient state is passed around in struct bpf_link_primer.
+ * This is preferred way to create and initialize bpf_link, especially when
+ * there are complicated and expensive operations inbetween creating bpf_link
+ * itself and attaching it to BPF hook. By using bpf_link_prime() and
+ * bpf_link_settle() kernel code using bpf_link doesn't have to perform
+ * expensive (and potentially failing) roll back operations in a rare case
+ * that file, FD, or ID can't be allocated.
+ */
+int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
+{
+	struct file *file;
+	int fd, id;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+
+
+	id = bpf_link_alloc_id(link);
+	if (id < 0) {
+		put_unused_fd(fd);
+		return id;
+	}
+
+	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
+	if (IS_ERR(file)) {
+		bpf_link_free_id(id);
+		put_unused_fd(fd);
+		return PTR_ERR(file);
+	}
+
+	primer->link = link;
+	primer->file = file;
+	primer->fd = fd;
+	primer->id = id;
+	return 0;
+}
+
+int bpf_link_settle(struct bpf_link_primer *primer)
+{
+	/* make bpf_link fetchable by ID */
+	spin_lock_bh(&link_idr_lock);
+	primer->link->id = primer->id;
+	spin_unlock_bh(&link_idr_lock);
+	/* make bpf_link fetchable by FD */
+	fd_install(primer->fd, primer->file);
+	/* pass through installed FD */
+	return primer->fd;
+}
+
+int bpf_link_new_fd(struct bpf_link *link)
+{
+	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
+}
+
+struct bpf_link *bpf_link_get_from_fd(u32 ufd)
+{
+	struct fd f = fdget(ufd);
+	struct bpf_link *link;
+
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+	if (f.file->f_op != &bpf_link_fops) {
+		fdput(f);
+		return ERR_PTR(-EINVAL);
+	}
+
+	link = f.file->private_data;
+	bpf_link_inc(link);
+	fdput(f);
+
+	return link;
+}
+
+struct bpf_tracing_link {
+	struct bpf_link link;
+	enum bpf_attach_type attach_type;
+	struct bpf_trampoline *trampoline;
+	struct bpf_prog *tgt_prog;
+};
+
+static void bpf_tracing_link_release(struct bpf_link *link)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog,
+						tr_link->trampoline));
+
+	bpf_trampoline_put(tr_link->trampoline);
+
+	/* tgt_prog is NULL if target is a kernel function */
+	if (tr_link->tgt_prog)
+		bpf_prog_put(tr_link->tgt_prog);
+}
+
+static void bpf_tracing_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	kfree(tr_link);
+}
+
+static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
+					 struct seq_file *seq)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	seq_printf(seq,
+		   "attach_type:\t%d\n",
+		   tr_link->attach_type);
+}
+
+static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
+					   struct bpf_link_info *info)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	info->tracing.attach_type = tr_link->attach_type;
+
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_tracing_link_lops = {
+	.release = bpf_tracing_link_release,
+	.dealloc = bpf_tracing_link_dealloc,
+	.show_fdinfo = bpf_tracing_link_show_fdinfo,
+	.fill_link_info = bpf_tracing_link_fill_link_info,
+};
+
+static int bpf_tracing_prog_attach(struct bpf_prog *prog,
+				   int tgt_prog_fd,
+				   u32 btf_id)
+{
+	struct bpf_link_primer link_primer;
+	struct bpf_prog *tgt_prog = NULL;
+	struct bpf_trampoline *tr = NULL;
+	struct bpf_tracing_link *link;
+	u64 key = 0;
+	int err;
+
+	switch (prog->type) {
+	case BPF_PROG_TYPE_TRACING:
+		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
+		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
+		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		break;
+	case BPF_PROG_TYPE_EXT:
+		if (prog->expected_attach_type != 0) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		break;
+	case BPF_PROG_TYPE_LSM:
+		if (prog->expected_attach_type != BPF_LSM_MAC) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		break;
+	default:
+		err = -EINVAL;
+		goto out_put_prog;
+	}
+
+	if (!!tgt_prog_fd != !!btf_id) {
+		err = -EINVAL;
+		goto out_put_prog;
+	}
+
+	if (tgt_prog_fd) {
+		/* For now we only allow new targets for BPF_PROG_TYPE_EXT */
+		if (prog->type != BPF_PROG_TYPE_EXT) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+
+		tgt_prog = bpf_prog_get(tgt_prog_fd);
+		if (IS_ERR(tgt_prog)) {
+			err = PTR_ERR(tgt_prog);
+			tgt_prog = NULL;
+			goto out_put_prog;
+		}
+
+		key = bpf_trampoline_compute_key(tgt_prog, btf_id);
+	}
+
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto out_put_prog;
+	}
+	bpf_link_init(&link->link, BPF_LINK_TYPE_TRACING,
+		      &bpf_tracing_link_lops, prog);
+	link->attach_type = prog->expected_attach_type;
+
+	mutex_lock(&prog->aux->dst_mutex);
+
+	/* There are a few possible cases here:
+	 *
+	 * - if prog->aux->dst_trampoline is set, the program was just loaded
+	 *   and not yet attached to anything, so we can use the values stored
+	 *   in prog->aux
+	 *
+	 * - if prog->aux->dst_trampoline is NULL, the program has already been
+         *   attached to a target and its initial target was cleared (below)
+	 *
+	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
+	 *   target_btf_id using the link_create API.
+	 *
+	 * - if tgt_prog == NULL when this function was called using the old
+         *   raw_tracepoint_open API, and we need a target from prog->aux
+         *
+         * The combination of no saved target in prog->aux, and no target
+         * specified on load is illegal, and we reject that here.
+	 */
+	if (!prog->aux->dst_trampoline && !tgt_prog) {
+		err = -ENOENT;
+		goto out_unlock;
+	}
+
+	if (!prog->aux->dst_trampoline ||
+	    (key && key != prog->aux->dst_trampoline->key)) {
+		/* If there is no saved target, or the specified target is
+		 * different from the destination specified at load time, we
+		 * need a new trampoline and a check for compatibility
+		 */
+		struct bpf_attach_target_info tgt_info = {};
+
+		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
+					      &tgt_info);
+		if (err)
+			goto out_unlock;
+
+		tr = bpf_trampoline_get(key, &tgt_info);
+		if (!tr) {
+			err = -ENOMEM;
+			goto out_unlock;
+		}
+	} else {
+		/* The caller didn't specify a target, or the target was the
+		 * same as the destination supplied during program load. This
+		 * means we can reuse the trampoline and reference from program
+		 * load time, and there is no need to allocate a new one. This
+		 * can only happen once for any program, as the saved values in
+		 * prog->aux are cleared below.
+		 */
+		tr = prog->aux->dst_trampoline;
+		tgt_prog = prog->aux->dst_prog;
+	}
+
+	err = bpf_link_prime(&link->link, &link_primer);
+	if (err)
+		goto out_unlock;
+
+	err = bpf_trampoline_link_prog(prog, tr);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		link = NULL;
+		goto out_unlock;
+	}
+
+	link->tgt_prog = tgt_prog;
+	link->trampoline = tr;
+
+	/* Always clear the trampoline and target prog from prog->aux to make
+	 * sure the original attach destination is not kept alive after a
+	 * program is (re-)attached to another target.
+	 */
+	if (prog->aux->dst_prog &&
+	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
+		/* got extra prog ref from syscall, or attaching to different prog */
+		bpf_prog_put(prog->aux->dst_prog);
+	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
+		/* we allocated a new trampoline, so free the old one */
+		bpf_trampoline_put(prog->aux->dst_trampoline);
+
+	prog->aux->dst_prog = NULL;
+	prog->aux->dst_trampoline = NULL;
+	mutex_unlock(&prog->aux->dst_mutex);
+
+	return bpf_link_settle(&link_primer);
+out_unlock:
+	if (tr && tr != prog->aux->dst_trampoline)
+		bpf_trampoline_put(tr);
+	mutex_unlock(&prog->aux->dst_mutex);
+	kfree(link);
+out_put_prog:
+	if (tgt_prog_fd && tgt_prog)
+		bpf_prog_put(tgt_prog);
+	return err;
+}
+
+struct bpf_raw_tp_link {
+	struct bpf_link link;
+	struct bpf_raw_event_map *btp;
+};
+
+static void bpf_raw_tp_link_release(struct bpf_link *link)
+{
+	struct bpf_raw_tp_link *raw_tp =
+		container_of(link, struct bpf_raw_tp_link, link);
+
+	bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
+	bpf_put_raw_tracepoint(raw_tp->btp);
+}
+
+static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_raw_tp_link *raw_tp =
+		container_of(link, struct bpf_raw_tp_link, link);
+
+	kfree(raw_tp);
+}
+
+static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
+					struct seq_file *seq)
+{
+	struct bpf_raw_tp_link *raw_tp_link =
+		container_of(link, struct bpf_raw_tp_link, link);
+
+	seq_printf(seq,
+		   "tp_name:\t%s\n",
+		   raw_tp_link->btp->tp->name);
+}
+
+static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
+					  struct bpf_link_info *info)
+{
+	struct bpf_raw_tp_link *raw_tp_link =
+		container_of(link, struct bpf_raw_tp_link, link);
+	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
+	const char *tp_name = raw_tp_link->btp->tp->name;
+	u32 ulen = info->raw_tracepoint.tp_name_len;
+	size_t tp_len = strlen(tp_name);
+
+	if (!ulen ^ !ubuf)
+		return -EINVAL;
+
+	info->raw_tracepoint.tp_name_len = tp_len + 1;
+
+	if (!ubuf)
+		return 0;
+
+	if (ulen >= tp_len + 1) {
+		if (copy_to_user(ubuf, tp_name, tp_len + 1))
+			return -EFAULT;
+	} else {
+		char zero = '\0';
+
+		if (copy_to_user(ubuf, tp_name, ulen - 1))
+			return -EFAULT;
+		if (put_user(zero, ubuf + ulen - 1))
+			return -EFAULT;
+		return -ENOSPC;
+	}
+
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_raw_tp_link_lops = {
+	.release = bpf_raw_tp_link_release,
+	.dealloc = bpf_raw_tp_link_dealloc,
+	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
+	.fill_link_info = bpf_raw_tp_link_fill_link_info,
+};
+
 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
 
 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
 {
-	struct bpf_raw_tracepoint *raw_tp;
+	struct bpf_link_primer link_primer;
+	struct bpf_raw_tp_link *link;
 	struct bpf_raw_event_map *btp;
 	struct bpf_prog *prog;
-	char tp_name[128];
-	int tp_fd, err;
+	const char *tp_name;
+	char buf[128];
+	int err;
 
-	if (strncpy_from_user(tp_name, u64_to_user_ptr(attr->raw_tracepoint.name),
-			      sizeof(tp_name) - 1) < 0)
-		return -EFAULT;
-	tp_name[sizeof(tp_name) - 1] = 0;
-
-	btp = bpf_get_raw_tracepoint(tp_name);
-	if (!btp)
-		return -ENOENT;
-
-	raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER);
-	if (!raw_tp) {
-		err = -ENOMEM;
-		goto out_put_btp;
-	}
-	raw_tp->btp = btp;
+	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
+		return -EINVAL;
 
 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
-	if (IS_ERR(prog)) {
-		err = PTR_ERR(prog);
-		goto out_free_tp;
-	}
-	if (prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT &&
-	    prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE) {
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	switch (prog->type) {
+	case BPF_PROG_TYPE_TRACING:
+	case BPF_PROG_TYPE_EXT:
+	case BPF_PROG_TYPE_LSM:
+		if (attr->raw_tracepoint.name) {
+			/* The attach point for this category of programs
+			 * should be specified via btf_id during program load.
+			 */
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		if (prog->type == BPF_PROG_TYPE_TRACING &&
+		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
+			tp_name = prog->aux->attach_func_name;
+			break;
+		}
+		err = bpf_tracing_prog_attach(prog, 0, 0);
+		if (err >= 0)
+			return err;
+		goto out_put_prog;
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
+		if (strncpy_from_user(buf,
+				      u64_to_user_ptr(attr->raw_tracepoint.name),
+				      sizeof(buf) - 1) < 0) {
+			err = -EFAULT;
+			goto out_put_prog;
+		}
+		buf[sizeof(buf) - 1] = 0;
+		tp_name = buf;
+		break;
+	default:
 		err = -EINVAL;
 		goto out_put_prog;
 	}
 
-	err = bpf_probe_register(raw_tp->btp, prog);
-	if (err)
-		goto out_put_prog;
-
-	raw_tp->prog = prog;
-	tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp,
-				 O_CLOEXEC);
-	if (tp_fd < 0) {
-		bpf_probe_unregister(raw_tp->btp, prog);
-		err = tp_fd;
+	btp = bpf_get_raw_tracepoint(tp_name);
+	if (!btp) {
+		err = -ENOENT;
 		goto out_put_prog;
 	}
-	return tp_fd;
 
-out_put_prog:
-	bpf_prog_put(prog);
-out_free_tp:
-	kfree(raw_tp);
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto out_put_btp;
+	}
+	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
+		      &bpf_raw_tp_link_lops, prog);
+	link->btp = btp;
+
+	err = bpf_link_prime(&link->link, &link_primer);
+	if (err) {
+		kfree(link);
+		goto out_put_btp;
+	}
+
+	err = bpf_probe_register(link->btp, prog);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		goto out_put_btp;
+	}
+
+	return bpf_link_settle(&link_primer);
+
 out_put_btp:
 	bpf_put_raw_tracepoint(btp);
+out_put_prog:
+	bpf_prog_put(prog);
 	return err;
 }
 
@@ -1881,8 +2913,14 @@
 	case BPF_PROG_TYPE_CGROUP_SOCK:
 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_SK_LOOKUP:
 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
 	case BPF_PROG_TYPE_CGROUP_SKB:
+		if (!capable(CAP_NET_ADMIN))
+			/* cg-skb progs can be loaded by unpriv user.
+			 * check permissions at attach time.
+			 */
+			return -EPERM;
 		return prog->enforce_expected_attach_type &&
 			prog->expected_attach_type != attach_type ?
 			-EINVAL : 0;
@@ -1891,10 +2929,64 @@
 	}
 }
 
-#define BPF_PROG_ATTACH_LAST_FIELD attach_flags
+static enum bpf_prog_type
+attach_type_to_prog_type(enum bpf_attach_type attach_type)
+{
+	switch (attach_type) {
+	case BPF_CGROUP_INET_INGRESS:
+	case BPF_CGROUP_INET_EGRESS:
+		return BPF_PROG_TYPE_CGROUP_SKB;
+	case BPF_CGROUP_INET_SOCK_CREATE:
+	case BPF_CGROUP_INET_SOCK_RELEASE:
+	case BPF_CGROUP_INET4_POST_BIND:
+	case BPF_CGROUP_INET6_POST_BIND:
+		return BPF_PROG_TYPE_CGROUP_SOCK;
+	case BPF_CGROUP_INET4_BIND:
+	case BPF_CGROUP_INET6_BIND:
+	case BPF_CGROUP_INET4_CONNECT:
+	case BPF_CGROUP_INET6_CONNECT:
+	case BPF_CGROUP_INET4_GETPEERNAME:
+	case BPF_CGROUP_INET6_GETPEERNAME:
+	case BPF_CGROUP_INET4_GETSOCKNAME:
+	case BPF_CGROUP_INET6_GETSOCKNAME:
+	case BPF_CGROUP_UDP4_SENDMSG:
+	case BPF_CGROUP_UDP6_SENDMSG:
+	case BPF_CGROUP_UDP4_RECVMSG:
+	case BPF_CGROUP_UDP6_RECVMSG:
+		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
+	case BPF_CGROUP_SOCK_OPS:
+		return BPF_PROG_TYPE_SOCK_OPS;
+	case BPF_CGROUP_DEVICE:
+		return BPF_PROG_TYPE_CGROUP_DEVICE;
+	case BPF_SK_MSG_VERDICT:
+		return BPF_PROG_TYPE_SK_MSG;
+	case BPF_SK_SKB_STREAM_PARSER:
+	case BPF_SK_SKB_STREAM_VERDICT:
+		return BPF_PROG_TYPE_SK_SKB;
+	case BPF_LIRC_MODE2:
+		return BPF_PROG_TYPE_LIRC_MODE2;
+	case BPF_FLOW_DISSECTOR:
+		return BPF_PROG_TYPE_FLOW_DISSECTOR;
+	case BPF_CGROUP_SYSCTL:
+		return BPF_PROG_TYPE_CGROUP_SYSCTL;
+	case BPF_CGROUP_GETSOCKOPT:
+	case BPF_CGROUP_SETSOCKOPT:
+		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
+	case BPF_TRACE_ITER:
+		return BPF_PROG_TYPE_TRACING;
+	case BPF_SK_LOOKUP:
+		return BPF_PROG_TYPE_SK_LOOKUP;
+	case BPF_XDP:
+		return BPF_PROG_TYPE_XDP;
+	default:
+		return BPF_PROG_TYPE_UNSPEC;
+	}
+}
+
+#define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd
 
 #define BPF_F_ATTACH_MASK \
-	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
+	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)
 
 static int bpf_prog_attach(const union bpf_attr *attr)
 {
@@ -1902,64 +2994,15 @@
 	struct bpf_prog *prog;
 	int ret;
 
-	if (!capable(CAP_NET_ADMIN))
-		return -EPERM;
-
 	if (CHECK_ATTR(BPF_PROG_ATTACH))
 		return -EINVAL;
 
 	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
 		return -EINVAL;
 
-	switch (attr->attach_type) {
-	case BPF_CGROUP_INET_INGRESS:
-	case BPF_CGROUP_INET_EGRESS:
-		ptype = BPF_PROG_TYPE_CGROUP_SKB;
-		break;
-	case BPF_CGROUP_INET_SOCK_CREATE:
-	case BPF_CGROUP_INET4_POST_BIND:
-	case BPF_CGROUP_INET6_POST_BIND:
-		ptype = BPF_PROG_TYPE_CGROUP_SOCK;
-		break;
-	case BPF_CGROUP_INET4_BIND:
-	case BPF_CGROUP_INET6_BIND:
-	case BPF_CGROUP_INET4_CONNECT:
-	case BPF_CGROUP_INET6_CONNECT:
-	case BPF_CGROUP_UDP4_SENDMSG:
-	case BPF_CGROUP_UDP6_SENDMSG:
-	case BPF_CGROUP_UDP4_RECVMSG:
-	case BPF_CGROUP_UDP6_RECVMSG:
-		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
-		break;
-	case BPF_CGROUP_SOCK_OPS:
-		ptype = BPF_PROG_TYPE_SOCK_OPS;
-		break;
-	case BPF_CGROUP_DEVICE:
-		ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
-		break;
-	case BPF_SK_MSG_VERDICT:
-		ptype = BPF_PROG_TYPE_SK_MSG;
-		break;
-	case BPF_SK_SKB_STREAM_PARSER:
-	case BPF_SK_SKB_STREAM_VERDICT:
-		ptype = BPF_PROG_TYPE_SK_SKB;
-		break;
-	case BPF_LIRC_MODE2:
-		ptype = BPF_PROG_TYPE_LIRC_MODE2;
-		break;
-	case BPF_FLOW_DISSECTOR:
-		ptype = BPF_PROG_TYPE_FLOW_DISSECTOR;
-		break;
-	case BPF_CGROUP_SYSCTL:
-		ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
-		break;
-	case BPF_CGROUP_GETSOCKOPT:
-	case BPF_CGROUP_SETSOCKOPT:
-		ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;
-		break;
-	default:
+	ptype = attach_type_to_prog_type(attr->attach_type);
+	if (ptype == BPF_PROG_TYPE_UNSPEC)
 		return -EINVAL;
-	}
 
 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
 	if (IS_ERR(prog))
@@ -1979,10 +3022,19 @@
 		ret = lirc_prog_attach(attr, prog);
 		break;
 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
-		ret = skb_flow_dissector_bpf_prog_attach(attr, prog);
+		ret = netns_bpf_prog_attach(attr, prog);
+		break;
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SKB:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_SOCK_OPS:
+		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
 		break;
 	default:
-		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
+		ret = -EINVAL;
 	}
 
 	if (ret)
@@ -1996,59 +3048,30 @@
 {
 	enum bpf_prog_type ptype;
 
-	if (!capable(CAP_NET_ADMIN))
-		return -EPERM;
-
 	if (CHECK_ATTR(BPF_PROG_DETACH))
 		return -EINVAL;
 
-	switch (attr->attach_type) {
-	case BPF_CGROUP_INET_INGRESS:
-	case BPF_CGROUP_INET_EGRESS:
-		ptype = BPF_PROG_TYPE_CGROUP_SKB;
-		break;
-	case BPF_CGROUP_INET_SOCK_CREATE:
-	case BPF_CGROUP_INET4_POST_BIND:
-	case BPF_CGROUP_INET6_POST_BIND:
-		ptype = BPF_PROG_TYPE_CGROUP_SOCK;
-		break;
-	case BPF_CGROUP_INET4_BIND:
-	case BPF_CGROUP_INET6_BIND:
-	case BPF_CGROUP_INET4_CONNECT:
-	case BPF_CGROUP_INET6_CONNECT:
-	case BPF_CGROUP_UDP4_SENDMSG:
-	case BPF_CGROUP_UDP6_SENDMSG:
-	case BPF_CGROUP_UDP4_RECVMSG:
-	case BPF_CGROUP_UDP6_RECVMSG:
-		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
-		break;
-	case BPF_CGROUP_SOCK_OPS:
-		ptype = BPF_PROG_TYPE_SOCK_OPS;
-		break;
-	case BPF_CGROUP_DEVICE:
-		ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
-		break;
-	case BPF_SK_MSG_VERDICT:
-		return sock_map_prog_detach(attr, BPF_PROG_TYPE_SK_MSG);
-	case BPF_SK_SKB_STREAM_PARSER:
-	case BPF_SK_SKB_STREAM_VERDICT:
-		return sock_map_prog_detach(attr, BPF_PROG_TYPE_SK_SKB);
-	case BPF_LIRC_MODE2:
+	ptype = attach_type_to_prog_type(attr->attach_type);
+
+	switch (ptype) {
+	case BPF_PROG_TYPE_SK_MSG:
+	case BPF_PROG_TYPE_SK_SKB:
+		return sock_map_prog_detach(attr, ptype);
+	case BPF_PROG_TYPE_LIRC_MODE2:
 		return lirc_prog_detach(attr);
-	case BPF_FLOW_DISSECTOR:
-		return skb_flow_dissector_bpf_prog_detach(attr);
-	case BPF_CGROUP_SYSCTL:
-		ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
-		break;
-	case BPF_CGROUP_GETSOCKOPT:
-	case BPF_CGROUP_SETSOCKOPT:
-		ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;
-		break;
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+		return netns_bpf_prog_detach(attr, ptype);
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SKB:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_SOCK_OPS:
+		return cgroup_bpf_prog_detach(attr, ptype);
 	default:
 		return -EINVAL;
 	}
-
-	return cgroup_bpf_prog_detach(attr, ptype);
 }
 
 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
@@ -2067,12 +3090,17 @@
 	case BPF_CGROUP_INET_INGRESS:
 	case BPF_CGROUP_INET_EGRESS:
 	case BPF_CGROUP_INET_SOCK_CREATE:
+	case BPF_CGROUP_INET_SOCK_RELEASE:
 	case BPF_CGROUP_INET4_BIND:
 	case BPF_CGROUP_INET6_BIND:
 	case BPF_CGROUP_INET4_POST_BIND:
 	case BPF_CGROUP_INET6_POST_BIND:
 	case BPF_CGROUP_INET4_CONNECT:
 	case BPF_CGROUP_INET6_CONNECT:
+	case BPF_CGROUP_INET4_GETPEERNAME:
+	case BPF_CGROUP_INET6_GETPEERNAME:
+	case BPF_CGROUP_INET4_GETSOCKNAME:
+	case BPF_CGROUP_INET6_GETSOCKNAME:
 	case BPF_CGROUP_UDP4_SENDMSG:
 	case BPF_CGROUP_UDP6_SENDMSG:
 	case BPF_CGROUP_UDP4_RECVMSG:
@@ -2082,19 +3110,18 @@
 	case BPF_CGROUP_SYSCTL:
 	case BPF_CGROUP_GETSOCKOPT:
 	case BPF_CGROUP_SETSOCKOPT:
-		break;
+		return cgroup_bpf_prog_query(attr, uattr);
 	case BPF_LIRC_MODE2:
 		return lirc_prog_query(attr, uattr);
 	case BPF_FLOW_DISSECTOR:
-		return skb_flow_dissector_prog_query(attr, uattr);
+	case BPF_SK_LOOKUP:
+		return netns_bpf_prog_query(attr, uattr);
 	default:
 		return -EINVAL;
 	}
-
-	return cgroup_bpf_prog_query(attr, uattr);
 }
 
-#define BPF_PROG_TEST_RUN_LAST_FIELD test.ctx_out
+#define BPF_PROG_TEST_RUN_LAST_FIELD test.cpu
 
 static int bpf_prog_test_run(const union bpf_attr *attr,
 			     union bpf_attr __user *uattr)
@@ -2102,8 +3129,6 @@
 	struct bpf_prog *prog;
 	int ret = -ENOTSUPP;
 
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
 		return -EINVAL;
 
@@ -2154,8 +3179,63 @@
 	return err;
 }
 
+struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
+{
+	struct bpf_map *map;
+
+	spin_lock_bh(&map_idr_lock);
+again:
+	map = idr_get_next(&map_idr, id);
+	if (map) {
+		map = __bpf_map_inc_not_zero(map, false);
+		if (IS_ERR(map)) {
+			(*id)++;
+			goto again;
+		}
+	}
+	spin_unlock_bh(&map_idr_lock);
+
+	return map;
+}
+
+struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
+{
+	struct bpf_prog *prog;
+
+	spin_lock_bh(&prog_idr_lock);
+again:
+	prog = idr_get_next(&prog_idr, id);
+	if (prog) {
+		prog = bpf_prog_inc_not_zero(prog);
+		if (IS_ERR(prog)) {
+			(*id)++;
+			goto again;
+		}
+	}
+	spin_unlock_bh(&prog_idr_lock);
+
+	return prog;
+}
+
 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
 
+struct bpf_prog *bpf_prog_by_id(u32 id)
+{
+	struct bpf_prog *prog;
+
+	if (!id)
+		return ERR_PTR(-ENOENT);
+
+	spin_lock_bh(&prog_idr_lock);
+	prog = idr_find(&prog_idr, id);
+	if (prog)
+		prog = bpf_prog_inc_not_zero(prog);
+	else
+		prog = ERR_PTR(-ENOENT);
+	spin_unlock_bh(&prog_idr_lock);
+	return prog;
+}
+
 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
 {
 	struct bpf_prog *prog;
@@ -2168,14 +3248,7 @@
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	spin_lock_bh(&prog_idr_lock);
-	prog = idr_find(&prog_idr, id);
-	if (prog)
-		prog = bpf_prog_inc_not_zero(prog);
-	else
-		prog = ERR_PTR(-ENOENT);
-	spin_unlock_bh(&prog_idr_lock);
-
+	prog = bpf_prog_by_id(id);
 	if (IS_ERR(prog))
 		return PTR_ERR(prog);
 
@@ -2231,21 +3304,25 @@
 	const struct bpf_map *map;
 	int i;
 
+	mutex_lock(&prog->aux->used_maps_mutex);
 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
 		map = prog->aux->used_maps[i];
 		if (map == (void *)addr) {
 			*type = BPF_PSEUDO_MAP_FD;
-			return map;
+			goto out;
 		}
 		if (!map->ops->map_direct_value_meta)
 			continue;
 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
 			*type = BPF_PSEUDO_MAP_VALUE;
-			return map;
+			goto out;
 		}
 	}
+	map = NULL;
 
-	return NULL;
+out:
+	mutex_unlock(&prog->aux->used_maps_mutex);
+	return map;
 }
 
 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
@@ -2255,6 +3332,7 @@
 	struct bpf_insn *insns;
 	u32 off, type;
 	u64 imm;
+	u8 code;
 	int i;
 
 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
@@ -2263,21 +3341,27 @@
 		return insns;
 
 	for (i = 0; i < prog->len; i++) {
-		if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
+		code = insns[i].code;
+
+		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
 			insns[i].code = BPF_JMP | BPF_CALL;
 			insns[i].imm = BPF_FUNC_tail_call;
 			/* fall-through */
 		}
-		if (insns[i].code == (BPF_JMP | BPF_CALL) ||
-		    insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
-			if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
+		if (code == (BPF_JMP | BPF_CALL) ||
+		    code == (BPF_JMP | BPF_CALL_ARGS)) {
+			if (code == (BPF_JMP | BPF_CALL_ARGS))
 				insns[i].code = BPF_JMP | BPF_CALL;
 			if (!bpf_dump_raw_ok(f_cred))
 				insns[i].imm = 0;
 			continue;
 		}
+		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
+			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
+			continue;
+		}
 
-		if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
+		if (code != (BPF_LD | BPF_IMM | BPF_DW))
 			continue;
 
 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
@@ -2356,6 +3440,7 @@
 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
 
+	mutex_lock(&prog->aux->used_maps_mutex);
 	ulen = info.nr_map_ids;
 	info.nr_map_ids = prog->aux->used_map_cnt;
 	ulen = min_t(u32, info.nr_map_ids, ulen);
@@ -2365,9 +3450,12 @@
 
 		for (i = 0; i < ulen; i++)
 			if (put_user(prog->aux->used_maps[i]->id,
-				     &user_map_ids[i]))
+				     &user_map_ids[i])) {
+				mutex_unlock(&prog->aux->used_maps_mutex);
 				return -EFAULT;
+			}
 	}
+	mutex_unlock(&prog->aux->used_maps_mutex);
 
 	err = set_info_rec_size(&info);
 	if (err)
@@ -2377,7 +3465,7 @@
 	info.run_time_ns = stats.nsecs;
 	info.run_cnt = stats.cnt;
 
-	if (!capable(CAP_SYS_ADMIN)) {
+	if (!bpf_capable()) {
 		info.jited_prog_len = 0;
 		info.xlated_prog_len = 0;
 		info.nr_jited_ksyms = 0;
@@ -2630,6 +3718,7 @@
 		info.btf_key_type_id = map->btf_key_type_id;
 		info.btf_value_type_id = map->btf_value_type_id;
 	}
+	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
 
 	if (bpf_map_is_dev_bound(map)) {
 		err = bpf_map_offload_info_fill(&info, map);
@@ -2660,6 +3749,43 @@
 	return btf_get_info_by_fd(btf, attr, uattr);
 }
 
+static int bpf_link_get_info_by_fd(struct file *file,
+				  struct bpf_link *link,
+				  const union bpf_attr *attr,
+				  union bpf_attr __user *uattr)
+{
+	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
+	struct bpf_link_info info;
+	u32 info_len = attr->info.info_len;
+	int err;
+
+	err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
+	if (err)
+		return err;
+	info_len = min_t(u32, sizeof(info), info_len);
+
+	memset(&info, 0, sizeof(info));
+	if (copy_from_user(&info, uinfo, info_len))
+		return -EFAULT;
+
+	info.type = link->type;
+	info.id = link->id;
+	info.prog_id = link->prog->aux->id;
+
+	if (link->ops->fill_link_info) {
+		err = link->ops->fill_link_info(link, &info);
+		if (err)
+			return err;
+	}
+
+	if (copy_to_user(uinfo, &info, info_len) ||
+	    put_user(info_len, &uattr->info.info_len))
+		return -EFAULT;
+
+	return 0;
+}
+
+
 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
 
 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
@@ -2684,6 +3810,9 @@
 					     uattr);
 	else if (f.file->f_op == &btf_fops)
 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
+	else if (f.file->f_op == &bpf_link_fops)
+		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
+					      attr, uattr);
 	else
 		err = -EINVAL;
 
@@ -2698,7 +3827,7 @@
 	if (CHECK_ATTR(BPF_BTF_LOAD))
 		return -EINVAL;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!bpf_capable())
 		return -EPERM;
 
 	return btf_new_fd(attr);
@@ -2808,15 +3937,21 @@
 	if (err)
 		goto out;
 
-	if (file->f_op == &bpf_raw_tp_fops) {
-		struct bpf_raw_tracepoint *raw_tp = file->private_data;
-		struct bpf_raw_event_map *btp = raw_tp->btp;
+	if (file->f_op == &bpf_link_fops) {
+		struct bpf_link *link = file->private_data;
 
-		err = bpf_task_fd_query_copy(attr, uattr,
-					     raw_tp->prog->aux->id,
-					     BPF_FD_TYPE_RAW_TRACEPOINT,
-					     btp->tp->name, 0, 0);
-		goto put_file;
+		if (link->ops == &bpf_raw_tp_link_lops) {
+			struct bpf_raw_tp_link *raw_tp =
+				container_of(link, struct bpf_raw_tp_link, link);
+			struct bpf_raw_event_map *btp = raw_tp->btp;
+
+			err = bpf_task_fd_query_copy(attr, uattr,
+						     raw_tp->link.prog->aux->id,
+						     BPF_FD_TYPE_RAW_TRACEPOINT,
+						     btp->tp->name, 0, 0);
+			goto put_file;
+		}
+		goto out_not_supp;
 	}
 
 	event = perf_get_event(file);
@@ -2836,6 +3971,7 @@
 		goto put_file;
 	}
 
+out_not_supp:
 	err = -ENOTSUPP;
 put_file:
 	fput(file);
@@ -2843,12 +3979,411 @@
 	return err;
 }
 
+#define BPF_MAP_BATCH_LAST_FIELD batch.flags
+
+#define BPF_DO_BATCH(fn)			\
+	do {					\
+		if (!fn) {			\
+			err = -ENOTSUPP;	\
+			goto err_put;		\
+		}				\
+		err = fn(map, attr, uattr);	\
+	} while (0)
+
+static int bpf_map_do_batch(const union bpf_attr *attr,
+			    union bpf_attr __user *uattr,
+			    int cmd)
+{
+	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
+			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
+	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
+	struct bpf_map *map;
+	int err, ufd;
+	struct fd f;
+
+	if (CHECK_ATTR(BPF_MAP_BATCH))
+		return -EINVAL;
+
+	ufd = attr->batch.map_fd;
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	if (has_write)
+		bpf_map_write_active_inc(map);
+	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
+		err = -EPERM;
+		goto err_put;
+	}
+	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	if (cmd == BPF_MAP_LOOKUP_BATCH)
+		BPF_DO_BATCH(map->ops->map_lookup_batch);
+	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
+		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
+	else if (cmd == BPF_MAP_UPDATE_BATCH)
+		BPF_DO_BATCH(map->ops->map_update_batch);
+	else
+		BPF_DO_BATCH(map->ops->map_delete_batch);
+err_put:
+	if (has_write)
+		bpf_map_write_active_dec(map);
+	fdput(f);
+	return err;
+}
+
+static int tracing_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	if (attr->link_create.attach_type != prog->expected_attach_type)
+		return -EINVAL;
+
+	if (prog->expected_attach_type == BPF_TRACE_ITER)
+		return bpf_iter_link_attach(attr, prog);
+	else if (prog->type == BPF_PROG_TYPE_EXT)
+		return bpf_tracing_prog_attach(prog,
+					       attr->link_create.target_fd,
+					       attr->link_create.target_btf_id);
+	return -EINVAL;
+}
+
+#define BPF_LINK_CREATE_LAST_FIELD link_create.iter_info_len
+static int link_create(union bpf_attr *attr)
+{
+	enum bpf_prog_type ptype;
+	struct bpf_prog *prog;
+	int ret;
+
+	if (CHECK_ATTR(BPF_LINK_CREATE))
+		return -EINVAL;
+
+	prog = bpf_prog_get(attr->link_create.prog_fd);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	ret = bpf_prog_attach_check_attach_type(prog,
+						attr->link_create.attach_type);
+	if (ret)
+		goto out;
+
+	if (prog->type == BPF_PROG_TYPE_EXT) {
+		ret = tracing_bpf_link_attach(attr, prog);
+		goto out;
+	}
+
+	ptype = attach_type_to_prog_type(attr->link_create.attach_type);
+	if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	switch (ptype) {
+	case BPF_PROG_TYPE_CGROUP_SKB:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_SOCK_OPS:
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+		ret = cgroup_bpf_link_attach(attr, prog);
+		break;
+	case BPF_PROG_TYPE_TRACING:
+		ret = tracing_bpf_link_attach(attr, prog);
+		break;
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		ret = netns_bpf_link_create(attr, prog);
+		break;
+#ifdef CONFIG_NET
+	case BPF_PROG_TYPE_XDP:
+		ret = bpf_xdp_link_attach(attr, prog);
+		break;
+#endif
+	default:
+		ret = -EINVAL;
+	}
+
+out:
+	if (ret < 0)
+		bpf_prog_put(prog);
+	return ret;
+}
+
+#define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
+
+static int link_update(union bpf_attr *attr)
+{
+	struct bpf_prog *old_prog = NULL, *new_prog;
+	struct bpf_link *link;
+	u32 flags;
+	int ret;
+
+	if (CHECK_ATTR(BPF_LINK_UPDATE))
+		return -EINVAL;
+
+	flags = attr->link_update.flags;
+	if (flags & ~BPF_F_REPLACE)
+		return -EINVAL;
+
+	link = bpf_link_get_from_fd(attr->link_update.link_fd);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
+	if (IS_ERR(new_prog)) {
+		ret = PTR_ERR(new_prog);
+		goto out_put_link;
+	}
+
+	if (flags & BPF_F_REPLACE) {
+		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
+		if (IS_ERR(old_prog)) {
+			ret = PTR_ERR(old_prog);
+			old_prog = NULL;
+			goto out_put_progs;
+		}
+	} else if (attr->link_update.old_prog_fd) {
+		ret = -EINVAL;
+		goto out_put_progs;
+	}
+
+	if (link->ops->update_prog)
+		ret = link->ops->update_prog(link, new_prog, old_prog);
+	else
+		ret = -EINVAL;
+
+out_put_progs:
+	if (old_prog)
+		bpf_prog_put(old_prog);
+	if (ret)
+		bpf_prog_put(new_prog);
+out_put_link:
+	bpf_link_put(link);
+	return ret;
+}
+
+#define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
+
+static int link_detach(union bpf_attr *attr)
+{
+	struct bpf_link *link;
+	int ret;
+
+	if (CHECK_ATTR(BPF_LINK_DETACH))
+		return -EINVAL;
+
+	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	if (link->ops->detach)
+		ret = link->ops->detach(link);
+	else
+		ret = -EOPNOTSUPP;
+
+	bpf_link_put(link);
+	return ret;
+}
+
+static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
+{
+	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
+}
+
+struct bpf_link *bpf_link_by_id(u32 id)
+{
+	struct bpf_link *link;
+
+	if (!id)
+		return ERR_PTR(-ENOENT);
+
+	spin_lock_bh(&link_idr_lock);
+	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
+	link = idr_find(&link_idr, id);
+	if (link) {
+		if (link->id)
+			link = bpf_link_inc_not_zero(link);
+		else
+			link = ERR_PTR(-EAGAIN);
+	} else {
+		link = ERR_PTR(-ENOENT);
+	}
+	spin_unlock_bh(&link_idr_lock);
+	return link;
+}
+
+#define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
+
+static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
+{
+	struct bpf_link *link;
+	u32 id = attr->link_id;
+	int fd;
+
+	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	link = bpf_link_by_id(id);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	fd = bpf_link_new_fd(link);
+	if (fd < 0)
+		bpf_link_put(link);
+
+	return fd;
+}
+
+DEFINE_MUTEX(bpf_stats_enabled_mutex);
+
+static int bpf_stats_release(struct inode *inode, struct file *file)
+{
+	mutex_lock(&bpf_stats_enabled_mutex);
+	static_key_slow_dec(&bpf_stats_enabled_key.key);
+	mutex_unlock(&bpf_stats_enabled_mutex);
+	return 0;
+}
+
+static const struct file_operations bpf_stats_fops = {
+	.release = bpf_stats_release,
+};
+
+static int bpf_enable_runtime_stats(void)
+{
+	int fd;
+
+	mutex_lock(&bpf_stats_enabled_mutex);
+
+	/* Set a very high limit to avoid overflow */
+	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
+		mutex_unlock(&bpf_stats_enabled_mutex);
+		return -EBUSY;
+	}
+
+	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
+	if (fd >= 0)
+		static_key_slow_inc(&bpf_stats_enabled_key.key);
+
+	mutex_unlock(&bpf_stats_enabled_mutex);
+	return fd;
+}
+
+#define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
+
+static int bpf_enable_stats(union bpf_attr *attr)
+{
+
+	if (CHECK_ATTR(BPF_ENABLE_STATS))
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	switch (attr->enable_stats.type) {
+	case BPF_STATS_RUN_TIME:
+		return bpf_enable_runtime_stats();
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+#define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
+
+static int bpf_iter_create(union bpf_attr *attr)
+{
+	struct bpf_link *link;
+	int err;
+
+	if (CHECK_ATTR(BPF_ITER_CREATE))
+		return -EINVAL;
+
+	if (attr->iter_create.flags)
+		return -EINVAL;
+
+	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	err = bpf_iter_new_fd(link);
+	bpf_link_put(link);
+
+	return err;
+}
+
+#define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
+
+static int bpf_prog_bind_map(union bpf_attr *attr)
+{
+	struct bpf_prog *prog;
+	struct bpf_map *map;
+	struct bpf_map **used_maps_old, **used_maps_new;
+	int i, ret = 0;
+
+	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
+		return -EINVAL;
+
+	if (attr->prog_bind_map.flags)
+		return -EINVAL;
+
+	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	map = bpf_map_get(attr->prog_bind_map.map_fd);
+	if (IS_ERR(map)) {
+		ret = PTR_ERR(map);
+		goto out_prog_put;
+	}
+
+	mutex_lock(&prog->aux->used_maps_mutex);
+
+	used_maps_old = prog->aux->used_maps;
+
+	for (i = 0; i < prog->aux->used_map_cnt; i++)
+		if (used_maps_old[i] == map) {
+			bpf_map_put(map);
+			goto out_unlock;
+		}
+
+	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
+				      sizeof(used_maps_new[0]),
+				      GFP_KERNEL);
+	if (!used_maps_new) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
+
+	memcpy(used_maps_new, used_maps_old,
+	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
+	used_maps_new[prog->aux->used_map_cnt] = map;
+
+	prog->aux->used_map_cnt++;
+	prog->aux->used_maps = used_maps_new;
+
+	kfree(used_maps_old);
+
+out_unlock:
+	mutex_unlock(&prog->aux->used_maps_mutex);
+
+	if (ret)
+		bpf_map_put(map);
+out_prog_put:
+	bpf_prog_put(prog);
+	return ret;
+}
+
 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
 {
 	union bpf_attr attr;
 	int err;
 
-	if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))
+	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
 		return -EPERM;
 
 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
@@ -2941,6 +4476,44 @@
 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
 		err = map_lookup_and_delete_elem(&attr);
 		break;
+	case BPF_MAP_LOOKUP_BATCH:
+		err = bpf_map_do_batch(&attr, uattr, BPF_MAP_LOOKUP_BATCH);
+		break;
+	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
+		err = bpf_map_do_batch(&attr, uattr,
+				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
+		break;
+	case BPF_MAP_UPDATE_BATCH:
+		err = bpf_map_do_batch(&attr, uattr, BPF_MAP_UPDATE_BATCH);
+		break;
+	case BPF_MAP_DELETE_BATCH:
+		err = bpf_map_do_batch(&attr, uattr, BPF_MAP_DELETE_BATCH);
+		break;
+	case BPF_LINK_CREATE:
+		err = link_create(&attr);
+		break;
+	case BPF_LINK_UPDATE:
+		err = link_update(&attr);
+		break;
+	case BPF_LINK_GET_FD_BY_ID:
+		err = bpf_link_get_fd_by_id(&attr);
+		break;
+	case BPF_LINK_GET_NEXT_ID:
+		err = bpf_obj_get_next_id(&attr, uattr,
+					  &link_idr, &link_idr_lock);
+		break;
+	case BPF_ENABLE_STATS:
+		err = bpf_enable_stats(&attr);
+		break;
+	case BPF_ITER_CREATE:
+		err = bpf_iter_create(&attr);
+		break;
+	case BPF_LINK_DETACH:
+		err = link_detach(&attr);
+		break;
+	case BPF_PROG_BIND_MAP:
+		err = bpf_prog_bind_map(&attr);
+		break;
 	default:
 		err = -EINVAL;
 		break;
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
new file mode 100644
index 0000000..f3d3a56
--- /dev/null
+++ b/kernel/bpf/task_iter.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/pid_namespace.h>
+#include <linux/fs.h>
+#include <linux/fdtable.h>
+#include <linux/filter.h>
+#include <linux/btf_ids.h>
+
+struct bpf_iter_seq_task_common {
+	struct pid_namespace *ns;
+};
+
+struct bpf_iter_seq_task_info {
+	/* The first field must be struct bpf_iter_seq_task_common.
+	 * this is assumed by {init, fini}_seq_pidns() callback functions.
+	 */
+	struct bpf_iter_seq_task_common common;
+	u32 tid;
+};
+
+static struct task_struct *task_seq_get_next(struct pid_namespace *ns,
+					     u32 *tid,
+					     bool skip_if_dup_files)
+{
+	struct task_struct *task = NULL;
+	struct pid *pid;
+
+	rcu_read_lock();
+retry:
+	pid = find_ge_pid(*tid, ns);
+	if (pid) {
+		*tid = pid_nr_ns(pid, ns);
+		task = get_pid_task(pid, PIDTYPE_PID);
+		if (!task) {
+			++*tid;
+			goto retry;
+		} else if (skip_if_dup_files && task->tgid != task->pid &&
+			   task->files == task->group_leader->files) {
+			put_task_struct(task);
+			task = NULL;
+			++*tid;
+			goto retry;
+		}
+	}
+	rcu_read_unlock();
+
+	return task;
+}
+
+static void *task_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_task_info *info = seq->private;
+	struct task_struct *task;
+
+	task = task_seq_get_next(info->common.ns, &info->tid, false);
+	if (!task)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return task;
+}
+
+static void *task_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_task_info *info = seq->private;
+	struct task_struct *task;
+
+	++*pos;
+	++info->tid;
+	put_task_struct((struct task_struct *)v);
+	task = task_seq_get_next(info->common.ns, &info->tid, false);
+	if (!task)
+		return NULL;
+
+	return task;
+}
+
+struct bpf_iter__task {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct task_struct *, task);
+};
+
+DEFINE_BPF_ITER_FUNC(task, struct bpf_iter_meta *meta, struct task_struct *task)
+
+static int __task_seq_show(struct seq_file *seq, struct task_struct *task,
+			   bool in_stop)
+{
+	struct bpf_iter_meta meta;
+	struct bpf_iter__task ctx;
+	struct bpf_prog *prog;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (!prog)
+		return 0;
+
+	meta.seq = seq;
+	ctx.meta = &meta;
+	ctx.task = task;
+	return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int task_seq_show(struct seq_file *seq, void *v)
+{
+	return __task_seq_show(seq, v, false);
+}
+
+static void task_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__task_seq_show(seq, v, true);
+	else
+		put_task_struct((struct task_struct *)v);
+}
+
+static const struct seq_operations task_seq_ops = {
+	.start	= task_seq_start,
+	.next	= task_seq_next,
+	.stop	= task_seq_stop,
+	.show	= task_seq_show,
+};
+
+struct bpf_iter_seq_task_file_info {
+	/* The first field must be struct bpf_iter_seq_task_common.
+	 * this is assumed by {init, fini}_seq_pidns() callback functions.
+	 */
+	struct bpf_iter_seq_task_common common;
+	struct task_struct *task;
+	struct files_struct *files;
+	u32 tid;
+	u32 fd;
+};
+
+static struct file *
+task_file_seq_get_next(struct bpf_iter_seq_task_file_info *info)
+{
+	struct pid_namespace *ns = info->common.ns;
+	u32 curr_tid = info->tid, max_fds;
+	struct files_struct *curr_files;
+	struct task_struct *curr_task;
+	int curr_fd = info->fd;
+
+	/* If this function returns a non-NULL file object,
+	 * it held a reference to the task/files_struct/file.
+	 * Otherwise, it does not hold any reference.
+	 */
+again:
+	if (info->task) {
+		curr_task = info->task;
+		curr_files = info->files;
+		curr_fd = info->fd;
+	} else {
+		curr_task = task_seq_get_next(ns, &curr_tid, true);
+		if (!curr_task) {
+			info->task = NULL;
+			info->files = NULL;
+			info->tid = curr_tid;
+			return NULL;
+		}
+
+		curr_files = get_files_struct(curr_task);
+		if (!curr_files) {
+			put_task_struct(curr_task);
+			curr_tid = curr_tid + 1;
+			info->fd = 0;
+			goto again;
+		}
+
+		info->files = curr_files;
+		info->task = curr_task;
+		if (curr_tid == info->tid) {
+			curr_fd = info->fd;
+		} else {
+			info->tid = curr_tid;
+			curr_fd = 0;
+		}
+	}
+
+	rcu_read_lock();
+	max_fds = files_fdtable(curr_files)->max_fds;
+	for (; curr_fd < max_fds; curr_fd++) {
+		struct file *f;
+
+		f = fcheck_files(curr_files, curr_fd);
+		if (!f)
+			continue;
+		if (!get_file_rcu(f))
+			continue;
+
+		/* set info->fd */
+		info->fd = curr_fd;
+		rcu_read_unlock();
+		return f;
+	}
+
+	/* the current task is done, go to the next task */
+	rcu_read_unlock();
+	put_files_struct(curr_files);
+	put_task_struct(curr_task);
+	info->task = NULL;
+	info->files = NULL;
+	info->fd = 0;
+	curr_tid = ++(info->tid);
+	goto again;
+}
+
+static void *task_file_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+	struct file *file;
+
+	info->task = NULL;
+	info->files = NULL;
+	file = task_file_seq_get_next(info);
+	if (file && *pos == 0)
+		++*pos;
+
+	return file;
+}
+
+static void *task_file_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+
+	++*pos;
+	++info->fd;
+	fput((struct file *)v);
+	return task_file_seq_get_next(info);
+}
+
+struct bpf_iter__task_file {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct task_struct *, task);
+	u32 fd __aligned(8);
+	__bpf_md_ptr(struct file *, file);
+};
+
+DEFINE_BPF_ITER_FUNC(task_file, struct bpf_iter_meta *meta,
+		     struct task_struct *task, u32 fd,
+		     struct file *file)
+
+static int __task_file_seq_show(struct seq_file *seq, struct file *file,
+				bool in_stop)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+	struct bpf_iter__task_file ctx;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (!prog)
+		return 0;
+
+	ctx.meta = &meta;
+	ctx.task = info->task;
+	ctx.fd = info->fd;
+	ctx.file = file;
+	return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int task_file_seq_show(struct seq_file *seq, void *v)
+{
+	return __task_file_seq_show(seq, v, false);
+}
+
+static void task_file_seq_stop(struct seq_file *seq, void *v)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+
+	if (!v) {
+		(void)__task_file_seq_show(seq, v, true);
+	} else {
+		fput((struct file *)v);
+		put_files_struct(info->files);
+		put_task_struct(info->task);
+		info->files = NULL;
+		info->task = NULL;
+	}
+}
+
+static int init_seq_pidns(void *priv_data, struct bpf_iter_aux_info *aux)
+{
+	struct bpf_iter_seq_task_common *common = priv_data;
+
+	common->ns = get_pid_ns(task_active_pid_ns(current));
+	return 0;
+}
+
+static void fini_seq_pidns(void *priv_data)
+{
+	struct bpf_iter_seq_task_common *common = priv_data;
+
+	put_pid_ns(common->ns);
+}
+
+static const struct seq_operations task_file_seq_ops = {
+	.start	= task_file_seq_start,
+	.next	= task_file_seq_next,
+	.stop	= task_file_seq_stop,
+	.show	= task_file_seq_show,
+};
+
+BTF_ID_LIST(btf_task_file_ids)
+BTF_ID(struct, task_struct)
+BTF_ID(struct, file)
+
+static const struct bpf_iter_seq_info task_seq_info = {
+	.seq_ops		= &task_seq_ops,
+	.init_seq_private	= init_seq_pidns,
+	.fini_seq_private	= fini_seq_pidns,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_task_info),
+};
+
+static struct bpf_iter_reg task_reg_info = {
+	.target			= "task",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__task, task),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &task_seq_info,
+};
+
+static const struct bpf_iter_seq_info task_file_seq_info = {
+	.seq_ops		= &task_file_seq_ops,
+	.init_seq_private	= init_seq_pidns,
+	.fini_seq_private	= fini_seq_pidns,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_task_file_info),
+};
+
+static struct bpf_iter_reg task_file_reg_info = {
+	.target			= "task_file",
+	.ctx_arg_info_size	= 2,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__task_file, task),
+		  PTR_TO_BTF_ID_OR_NULL },
+		{ offsetof(struct bpf_iter__task_file, file),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &task_file_seq_info,
+};
+
+static int __init task_iter_init(void)
+{
+	int ret;
+
+	task_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0];
+	ret = bpf_iter_reg_target(&task_reg_info);
+	if (ret)
+		return ret;
+
+	task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0];
+	task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[1];
+	return bpf_iter_reg_target(&task_file_reg_info);
+}
+late_initcall(task_iter_init);
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index d4f335a..ceac528 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -194,3 +194,18 @@
 	str[min(size - 1, (size_t)64)] = 0;
 	return 64;
 }
+
+struct tnum tnum_subreg(struct tnum a)
+{
+	return tnum_cast(a, 4);
+}
+
+struct tnum tnum_clear_subreg(struct tnum a)
+{
+	return tnum_lshift(tnum_rshift(a, 32), 32);
+}
+
+struct tnum tnum_const_subreg(struct tnum a, u32 value)
+{
+	return tnum_or(tnum_clear_subreg(a), tnum_const(value));
+}
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
new file mode 100644
index 0000000..986dabc
--- /dev/null
+++ b/kernel/bpf/trampoline.c
@@ -0,0 +1,571 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019 Facebook */
+#include <linux/hash.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/ftrace.h>
+#include <linux/rbtree_latch.h>
+#include <linux/perf_event.h>
+#include <linux/btf.h>
+#include <linux/rcupdate_trace.h>
+#include <linux/rcupdate_wait.h>
+
+/* dummy _ops. The verifier will operate on target program's ops. */
+const struct bpf_verifier_ops bpf_extension_verifier_ops = {
+};
+const struct bpf_prog_ops bpf_extension_prog_ops = {
+};
+
+/* btf_vmlinux has ~22k attachable functions. 1k htab is enough. */
+#define TRAMPOLINE_HASH_BITS 10
+#define TRAMPOLINE_TABLE_SIZE (1 << TRAMPOLINE_HASH_BITS)
+
+static struct hlist_head trampoline_table[TRAMPOLINE_TABLE_SIZE];
+
+/* serializes access to trampoline_table */
+static DEFINE_MUTEX(trampoline_mutex);
+
+void *bpf_jit_alloc_exec_page(void)
+{
+	void *image;
+
+	image = bpf_jit_alloc_exec(PAGE_SIZE);
+	if (!image)
+		return NULL;
+
+	set_vm_flush_reset_perms(image);
+	/* Keep image as writeable. The alternative is to keep flipping ro/rw
+	 * everytime new program is attached or detached.
+	 */
+	set_memory_x((long)image, 1);
+	return image;
+}
+
+void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym)
+{
+	ksym->start = (unsigned long) data;
+	ksym->end = ksym->start + PAGE_SIZE;
+	bpf_ksym_add(ksym);
+	perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
+			   PAGE_SIZE, false, ksym->name);
+}
+
+void bpf_image_ksym_del(struct bpf_ksym *ksym)
+{
+	bpf_ksym_del(ksym);
+	perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
+			   PAGE_SIZE, true, ksym->name);
+}
+
+static struct bpf_trampoline *bpf_trampoline_lookup(u64 key)
+{
+	struct bpf_trampoline *tr;
+	struct hlist_head *head;
+	int i;
+
+	mutex_lock(&trampoline_mutex);
+	head = &trampoline_table[hash_64(key, TRAMPOLINE_HASH_BITS)];
+	hlist_for_each_entry(tr, head, hlist) {
+		if (tr->key == key) {
+			refcount_inc(&tr->refcnt);
+			goto out;
+		}
+	}
+	tr = kzalloc(sizeof(*tr), GFP_KERNEL);
+	if (!tr)
+		goto out;
+
+	tr->key = key;
+	INIT_HLIST_NODE(&tr->hlist);
+	hlist_add_head(&tr->hlist, head);
+	refcount_set(&tr->refcnt, 1);
+	mutex_init(&tr->mutex);
+	for (i = 0; i < BPF_TRAMP_MAX; i++)
+		INIT_HLIST_HEAD(&tr->progs_hlist[i]);
+out:
+	mutex_unlock(&trampoline_mutex);
+	return tr;
+}
+
+static int is_ftrace_location(void *ip)
+{
+	long addr;
+
+	addr = ftrace_location((long)ip);
+	if (!addr)
+		return 0;
+	if (WARN_ON_ONCE(addr != (long)ip))
+		return -EFAULT;
+	return 1;
+}
+
+static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)
+{
+	void *ip = tr->func.addr;
+	int ret;
+
+	if (tr->func.ftrace_managed)
+		ret = unregister_ftrace_direct((long)ip, (long)old_addr);
+	else
+		ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, NULL);
+	return ret;
+}
+
+static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_addr)
+{
+	void *ip = tr->func.addr;
+	int ret;
+
+	if (tr->func.ftrace_managed)
+		ret = modify_ftrace_direct((long)ip, (long)old_addr, (long)new_addr);
+	else
+		ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, new_addr);
+	return ret;
+}
+
+/* first time registering */
+static int register_fentry(struct bpf_trampoline *tr, void *new_addr)
+{
+	void *ip = tr->func.addr;
+	int ret;
+
+	ret = is_ftrace_location(ip);
+	if (ret < 0)
+		return ret;
+	tr->func.ftrace_managed = ret;
+
+	if (tr->func.ftrace_managed)
+		ret = register_ftrace_direct((long)ip, (long)new_addr);
+	else
+		ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, NULL, new_addr);
+	return ret;
+}
+
+static struct bpf_tramp_progs *
+bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total)
+{
+	const struct bpf_prog_aux *aux;
+	struct bpf_tramp_progs *tprogs;
+	struct bpf_prog **progs;
+	int kind;
+
+	*total = 0;
+	tprogs = kcalloc(BPF_TRAMP_MAX, sizeof(*tprogs), GFP_KERNEL);
+	if (!tprogs)
+		return ERR_PTR(-ENOMEM);
+
+	for (kind = 0; kind < BPF_TRAMP_MAX; kind++) {
+		tprogs[kind].nr_progs = tr->progs_cnt[kind];
+		*total += tr->progs_cnt[kind];
+		progs = tprogs[kind].progs;
+
+		hlist_for_each_entry(aux, &tr->progs_hlist[kind], tramp_hlist)
+			*progs++ = aux->prog;
+	}
+	return tprogs;
+}
+
+static void __bpf_tramp_image_put_deferred(struct work_struct *work)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(work, struct bpf_tramp_image, work);
+	bpf_image_ksym_del(&im->ksym);
+	bpf_jit_free_exec(im->image);
+	bpf_jit_uncharge_modmem(1);
+	percpu_ref_exit(&im->pcref);
+	kfree_rcu(im, rcu);
+}
+
+/* callback, fexit step 3 or fentry step 2 */
+static void __bpf_tramp_image_put_rcu(struct rcu_head *rcu)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(rcu, struct bpf_tramp_image, rcu);
+	INIT_WORK(&im->work, __bpf_tramp_image_put_deferred);
+	schedule_work(&im->work);
+}
+
+/* callback, fexit step 2. Called after percpu_ref_kill confirms. */
+static void __bpf_tramp_image_release(struct percpu_ref *pcref)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(pcref, struct bpf_tramp_image, pcref);
+	call_rcu_tasks(&im->rcu, __bpf_tramp_image_put_rcu);
+}
+
+/* callback, fexit or fentry step 1 */
+static void __bpf_tramp_image_put_rcu_tasks(struct rcu_head *rcu)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(rcu, struct bpf_tramp_image, rcu);
+	if (im->ip_after_call)
+		/* the case of fmod_ret/fexit trampoline and CONFIG_PREEMPTION=y */
+		percpu_ref_kill(&im->pcref);
+	else
+		/* the case of fentry trampoline */
+		call_rcu_tasks(&im->rcu, __bpf_tramp_image_put_rcu);
+}
+
+static void bpf_tramp_image_put(struct bpf_tramp_image *im)
+{
+	/* The trampoline image that calls original function is using:
+	 * rcu_read_lock_trace to protect sleepable bpf progs
+	 * rcu_read_lock to protect normal bpf progs
+	 * percpu_ref to protect trampoline itself
+	 * rcu tasks to protect trampoline asm not covered by percpu_ref
+	 * (which are few asm insns before __bpf_tramp_enter and
+	 *  after __bpf_tramp_exit)
+	 *
+	 * The trampoline is unreachable before bpf_tramp_image_put().
+	 *
+	 * First, patch the trampoline to avoid calling into fexit progs.
+	 * The progs will be freed even if the original function is still
+	 * executing or sleeping.
+	 * In case of CONFIG_PREEMPT=y use call_rcu_tasks() to wait on
+	 * first few asm instructions to execute and call into
+	 * __bpf_tramp_enter->percpu_ref_get.
+	 * Then use percpu_ref_kill to wait for the trampoline and the original
+	 * function to finish.
+	 * Then use call_rcu_tasks() to make sure few asm insns in
+	 * the trampoline epilogue are done as well.
+	 *
+	 * In !PREEMPT case the task that got interrupted in the first asm
+	 * insns won't go through an RCU quiescent state which the
+	 * percpu_ref_kill will be waiting for. Hence the first
+	 * call_rcu_tasks() is not necessary.
+	 */
+	if (im->ip_after_call) {
+		int err = bpf_arch_text_poke(im->ip_after_call, BPF_MOD_JUMP,
+					     NULL, im->ip_epilogue);
+		WARN_ON(err);
+		if (IS_ENABLED(CONFIG_PREEMPTION))
+			call_rcu_tasks(&im->rcu, __bpf_tramp_image_put_rcu_tasks);
+		else
+			percpu_ref_kill(&im->pcref);
+		return;
+	}
+
+	/* The trampoline without fexit and fmod_ret progs doesn't call original
+	 * function and doesn't use percpu_ref.
+	 * Use call_rcu_tasks_trace() to wait for sleepable progs to finish.
+	 * Then use call_rcu_tasks() to wait for the rest of trampoline asm
+	 * and normal progs.
+	 */
+	call_rcu_tasks_trace(&im->rcu, __bpf_tramp_image_put_rcu_tasks);
+}
+
+static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key, u32 idx)
+{
+	struct bpf_tramp_image *im;
+	struct bpf_ksym *ksym;
+	void *image;
+	int err = -ENOMEM;
+
+	im = kzalloc(sizeof(*im), GFP_KERNEL);
+	if (!im)
+		goto out;
+
+	err = bpf_jit_charge_modmem(1);
+	if (err)
+		goto out_free_im;
+
+	err = -ENOMEM;
+	im->image = image = bpf_jit_alloc_exec_page();
+	if (!image)
+		goto out_uncharge;
+
+	err = percpu_ref_init(&im->pcref, __bpf_tramp_image_release, 0, GFP_KERNEL);
+	if (err)
+		goto out_free_image;
+
+	ksym = &im->ksym;
+	INIT_LIST_HEAD_RCU(&ksym->lnode);
+	snprintf(ksym->name, KSYM_NAME_LEN, "bpf_trampoline_%llu_%u", key, idx);
+	bpf_image_ksym_add(image, ksym);
+	return im;
+
+out_free_image:
+	bpf_jit_free_exec(im->image);
+out_uncharge:
+	bpf_jit_uncharge_modmem(1);
+out_free_im:
+	kfree(im);
+out:
+	return ERR_PTR(err);
+}
+
+static int bpf_trampoline_update(struct bpf_trampoline *tr)
+{
+	struct bpf_tramp_image *im;
+	struct bpf_tramp_progs *tprogs;
+	u32 flags = BPF_TRAMP_F_RESTORE_REGS;
+	int err, total;
+
+	tprogs = bpf_trampoline_get_progs(tr, &total);
+	if (IS_ERR(tprogs))
+		return PTR_ERR(tprogs);
+
+	if (total == 0) {
+		err = unregister_fentry(tr, tr->cur_image->image);
+		bpf_tramp_image_put(tr->cur_image);
+		tr->cur_image = NULL;
+		tr->selector = 0;
+		goto out;
+	}
+
+	im = bpf_tramp_image_alloc(tr->key, tr->selector);
+	if (IS_ERR(im)) {
+		err = PTR_ERR(im);
+		goto out;
+	}
+
+	if (tprogs[BPF_TRAMP_FEXIT].nr_progs ||
+	    tprogs[BPF_TRAMP_MODIFY_RETURN].nr_progs)
+		flags = BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME;
+
+	err = arch_prepare_bpf_trampoline(im, im->image, im->image + PAGE_SIZE,
+					  &tr->func.model, flags, tprogs,
+					  tr->func.addr);
+	if (err < 0)
+		goto out;
+
+	WARN_ON(tr->cur_image && tr->selector == 0);
+	WARN_ON(!tr->cur_image && tr->selector);
+	if (tr->cur_image)
+		/* progs already running at this address */
+		err = modify_fentry(tr, tr->cur_image->image, im->image);
+	else
+		/* first time registering */
+		err = register_fentry(tr, im->image);
+	if (err)
+		goto out;
+	if (tr->cur_image)
+		bpf_tramp_image_put(tr->cur_image);
+	tr->cur_image = im;
+	tr->selector++;
+out:
+	kfree(tprogs);
+	return err;
+}
+
+static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog)
+{
+	switch (prog->expected_attach_type) {
+	case BPF_TRACE_FENTRY:
+		return BPF_TRAMP_FENTRY;
+	case BPF_MODIFY_RETURN:
+		return BPF_TRAMP_MODIFY_RETURN;
+	case BPF_TRACE_FEXIT:
+		return BPF_TRAMP_FEXIT;
+	case BPF_LSM_MAC:
+		if (!prog->aux->attach_func_proto->type)
+			/* The function returns void, we cannot modify its
+			 * return value.
+			 */
+			return BPF_TRAMP_FEXIT;
+		else
+			return BPF_TRAMP_MODIFY_RETURN;
+	default:
+		return BPF_TRAMP_REPLACE;
+	}
+}
+
+int bpf_trampoline_link_prog(struct bpf_prog *prog, struct bpf_trampoline *tr)
+{
+	enum bpf_tramp_prog_type kind;
+	int err = 0;
+	int cnt;
+
+	kind = bpf_attach_type_to_tramp(prog);
+	mutex_lock(&tr->mutex);
+	if (tr->extension_prog) {
+		/* cannot attach fentry/fexit if extension prog is attached.
+		 * cannot overwrite extension prog either.
+		 */
+		err = -EBUSY;
+		goto out;
+	}
+	cnt = tr->progs_cnt[BPF_TRAMP_FENTRY] + tr->progs_cnt[BPF_TRAMP_FEXIT];
+	if (kind == BPF_TRAMP_REPLACE) {
+		/* Cannot attach extension if fentry/fexit are in use. */
+		if (cnt) {
+			err = -EBUSY;
+			goto out;
+		}
+		tr->extension_prog = prog;
+		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,
+					 prog->bpf_func);
+		goto out;
+	}
+	if (cnt >= BPF_MAX_TRAMP_PROGS) {
+		err = -E2BIG;
+		goto out;
+	}
+	if (!hlist_unhashed(&prog->aux->tramp_hlist)) {
+		/* prog already linked */
+		err = -EBUSY;
+		goto out;
+	}
+	hlist_add_head(&prog->aux->tramp_hlist, &tr->progs_hlist[kind]);
+	tr->progs_cnt[kind]++;
+	err = bpf_trampoline_update(tr);
+	if (err) {
+		hlist_del(&prog->aux->tramp_hlist);
+		tr->progs_cnt[kind]--;
+	}
+out:
+	mutex_unlock(&tr->mutex);
+	return err;
+}
+
+/* bpf_trampoline_unlink_prog() should never fail. */
+int bpf_trampoline_unlink_prog(struct bpf_prog *prog, struct bpf_trampoline *tr)
+{
+	enum bpf_tramp_prog_type kind;
+	int err;
+
+	kind = bpf_attach_type_to_tramp(prog);
+	mutex_lock(&tr->mutex);
+	if (kind == BPF_TRAMP_REPLACE) {
+		WARN_ON_ONCE(!tr->extension_prog);
+		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP,
+					 tr->extension_prog->bpf_func, NULL);
+		tr->extension_prog = NULL;
+		goto out;
+	}
+	hlist_del(&prog->aux->tramp_hlist);
+	tr->progs_cnt[kind]--;
+	err = bpf_trampoline_update(tr);
+out:
+	mutex_unlock(&tr->mutex);
+	return err;
+}
+
+struct bpf_trampoline *bpf_trampoline_get(u64 key,
+					  struct bpf_attach_target_info *tgt_info)
+{
+	struct bpf_trampoline *tr;
+
+	tr = bpf_trampoline_lookup(key);
+	if (!tr)
+		return NULL;
+
+	mutex_lock(&tr->mutex);
+	if (tr->func.addr)
+		goto out;
+
+	memcpy(&tr->func.model, &tgt_info->fmodel, sizeof(tgt_info->fmodel));
+	tr->func.addr = (void *)tgt_info->tgt_addr;
+out:
+	mutex_unlock(&tr->mutex);
+	return tr;
+}
+
+void bpf_trampoline_put(struct bpf_trampoline *tr)
+{
+	if (!tr)
+		return;
+	mutex_lock(&trampoline_mutex);
+	if (!refcount_dec_and_test(&tr->refcnt))
+		goto out;
+	WARN_ON_ONCE(mutex_is_locked(&tr->mutex));
+	if (WARN_ON_ONCE(!hlist_empty(&tr->progs_hlist[BPF_TRAMP_FENTRY])))
+		goto out;
+	if (WARN_ON_ONCE(!hlist_empty(&tr->progs_hlist[BPF_TRAMP_FEXIT])))
+		goto out;
+	/* This code will be executed even when the last bpf_tramp_image
+	 * is alive. All progs are detached from the trampoline and the
+	 * trampoline image is patched with jmp into epilogue to skip
+	 * fexit progs. The fentry-only trampoline will be freed via
+	 * multiple rcu callbacks.
+	 */
+	hlist_del(&tr->hlist);
+	kfree(tr);
+out:
+	mutex_unlock(&trampoline_mutex);
+}
+
+/* The logic is similar to BPF_PROG_RUN, but with an explicit
+ * rcu_read_lock() and migrate_disable() which are required
+ * for the trampoline. The macro is split into
+ * call _bpf_prog_enter
+ * call prog->bpf_func
+ * call __bpf_prog_exit
+ */
+u64 notrace __bpf_prog_enter(void)
+	__acquires(RCU)
+{
+	u64 start = 0;
+
+	rcu_read_lock();
+	migrate_disable();
+	if (static_branch_unlikely(&bpf_stats_enabled_key))
+		start = sched_clock();
+	return start;
+}
+
+void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start)
+	__releases(RCU)
+{
+	struct bpf_prog_stats *stats;
+
+	if (static_branch_unlikely(&bpf_stats_enabled_key) &&
+	    /* static_key could be enabled in __bpf_prog_enter
+	     * and disabled in __bpf_prog_exit.
+	     * And vice versa.
+	     * Hence check that 'start' is not zero.
+	     */
+	    start) {
+		stats = this_cpu_ptr(prog->aux->stats);
+		u64_stats_update_begin(&stats->syncp);
+		stats->cnt++;
+		stats->nsecs += sched_clock() - start;
+		u64_stats_update_end(&stats->syncp);
+	}
+	migrate_enable();
+	rcu_read_unlock();
+}
+
+void notrace __bpf_prog_enter_sleepable(void)
+{
+	rcu_read_lock_trace();
+	might_fault();
+}
+
+void notrace __bpf_prog_exit_sleepable(void)
+{
+	rcu_read_unlock_trace();
+}
+
+void notrace __bpf_tramp_enter(struct bpf_tramp_image *tr)
+{
+	percpu_ref_get(&tr->pcref);
+}
+
+void notrace __bpf_tramp_exit(struct bpf_tramp_image *tr)
+{
+	percpu_ref_put(&tr->pcref);
+}
+
+int __weak
+arch_prepare_bpf_trampoline(struct bpf_tramp_image *tr, void *image, void *image_end,
+			    const struct btf_func_model *m, u32 flags,
+			    struct bpf_tramp_progs *tprogs,
+			    void *orig_call)
+{
+	return -ENOTSUPP;
+}
+
+static int __init init_trampolines(void)
+{
+	int i;
+
+	for (i = 0; i < TRAMPOLINE_TABLE_SIZE; i++)
+		INIT_HLIST_HEAD(&trampoline_table[i]);
+	return 0;
+}
+late_initcall(init_trampolines);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 60383b2..015bf2b 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -19,16 +19,21 @@
 #include <linux/sort.h>
 #include <linux/perf_event.h>
 #include <linux/ctype.h>
+#include <linux/error-injection.h>
+#include <linux/bpf_lsm.h>
+#include <linux/btf_ids.h>
 
 #include "disasm.h"
 
 static const struct bpf_verifier_ops * const bpf_verifier_ops[] = {
-#define BPF_PROG_TYPE(_id, _name) \
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
 	[_id] = & _name ## _verifier_ops,
 #define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name)
 #include <linux/bpf_types.h>
 #undef BPF_PROG_TYPE
 #undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
 };
 
 /* bpf_check() is a static code analyzer that walks eBPF program
@@ -166,11 +171,16 @@
 	int insn_idx;
 	int prev_insn_idx;
 	struct bpf_verifier_stack_elem *next;
+	/* length of verifier log at the time this state was pushed on stack */
+	u32 log_pos;
 };
 
 #define BPF_COMPLEXITY_LIMIT_JMP_SEQ	8192
 #define BPF_COMPLEXITY_LIMIT_STATES	64
 
+#define BPF_MAP_KEY_POISON	(1ULL << 63)
+#define BPF_MAP_KEY_SEEN	(1ULL << 62)
+
 #define BPF_MAP_PTR_UNPRIV	1UL
 #define BPF_MAP_PTR_POISON	((void *)((0xeB9FUL << 1) +	\
 					  POISON_POINTER_DELTA))
@@ -178,12 +188,12 @@
 
 static bool bpf_map_ptr_poisoned(const struct bpf_insn_aux_data *aux)
 {
-	return BPF_MAP_PTR(aux->map_state) == BPF_MAP_PTR_POISON;
+	return BPF_MAP_PTR(aux->map_ptr_state) == BPF_MAP_PTR_POISON;
 }
 
 static bool bpf_map_ptr_unpriv(const struct bpf_insn_aux_data *aux)
 {
-	return aux->map_state & BPF_MAP_PTR_UNPRIV;
+	return aux->map_ptr_state & BPF_MAP_PTR_UNPRIV;
 }
 
 static void bpf_map_ptr_store(struct bpf_insn_aux_data *aux,
@@ -191,8 +201,31 @@
 {
 	BUILD_BUG_ON((unsigned long)BPF_MAP_PTR_POISON & BPF_MAP_PTR_UNPRIV);
 	unpriv |= bpf_map_ptr_unpriv(aux);
-	aux->map_state = (unsigned long)map |
-			 (unpriv ? BPF_MAP_PTR_UNPRIV : 0UL);
+	aux->map_ptr_state = (unsigned long)map |
+			     (unpriv ? BPF_MAP_PTR_UNPRIV : 0UL);
+}
+
+static bool bpf_map_key_poisoned(const struct bpf_insn_aux_data *aux)
+{
+	return aux->map_key_state & BPF_MAP_KEY_POISON;
+}
+
+static bool bpf_map_key_unseen(const struct bpf_insn_aux_data *aux)
+{
+	return !(aux->map_key_state & BPF_MAP_KEY_SEEN);
+}
+
+static u64 bpf_map_key_immediate(const struct bpf_insn_aux_data *aux)
+{
+	return aux->map_key_state & ~(BPF_MAP_KEY_SEEN | BPF_MAP_KEY_POISON);
+}
+
+static void bpf_map_key_store(struct bpf_insn_aux_data *aux, u64 state)
+{
+	bool poisoned = bpf_map_key_poisoned(aux);
+
+	aux->map_key_state = state | BPF_MAP_KEY_SEEN |
+			     (poisoned ? BPF_MAP_KEY_POISON : 0ULL);
 }
 
 struct bpf_call_arg_meta {
@@ -201,11 +234,16 @@
 	bool pkt_access;
 	int regno;
 	int access_size;
+	int mem_size;
 	u64 msize_max_value;
 	int ref_obj_id;
 	int func_id;
+	u32 btf_id;
+	u32 ret_btf_id;
 };
 
+struct btf *btf_vmlinux;
+
 static DEFINE_MUTEX(bpf_verifier_lock);
 
 static const struct bpf_line_info *
@@ -242,12 +280,28 @@
 	n = min(log->len_total - log->len_used - 1, n);
 	log->kbuf[n] = '\0';
 
+	if (log->level == BPF_LOG_KERNEL) {
+		pr_err("BPF:%s\n", log->kbuf);
+		return;
+	}
 	if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1))
 		log->len_used += n;
 	else
 		log->ubuf = NULL;
 }
 
+static void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos)
+{
+	char zero = 0;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	log->len_used = new_pos;
+	if (put_user(zero, log->ubuf + new_pos))
+		log->ubuf = NULL;
+}
+
 /* log_level controls verbosity level of eBPF verifier.
  * bpf_verifier_log_write() is used to dump the verification trace to the log,
  * so the user can figure out what's wrong with the program
@@ -279,6 +333,19 @@
 	va_end(args);
 }
 
+__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
+			    const char *fmt, ...)
+{
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	va_start(args, fmt);
+	bpf_verifier_vlog(log, fmt, args);
+	va_end(args);
+}
+
 static const char *ltrim(const char *s)
 {
 	while (isspace(*s))
@@ -329,12 +396,24 @@
 		type == PTR_TO_XDP_SOCK;
 }
 
+static bool reg_type_not_null(enum bpf_reg_type type)
+{
+	return type == PTR_TO_SOCKET ||
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_MAP_VALUE ||
+		type == PTR_TO_SOCK_COMMON;
+}
+
 static bool reg_type_may_be_null(enum bpf_reg_type type)
 {
 	return type == PTR_TO_MAP_VALUE_OR_NULL ||
 	       type == PTR_TO_SOCKET_OR_NULL ||
 	       type == PTR_TO_SOCK_COMMON_OR_NULL ||
-	       type == PTR_TO_TCP_SOCK_OR_NULL;
+	       type == PTR_TO_TCP_SOCK_OR_NULL ||
+	       type == PTR_TO_BTF_ID_OR_NULL ||
+	       type == PTR_TO_MEM_OR_NULL ||
+	       type == PTR_TO_RDONLY_BUF_OR_NULL ||
+	       type == PTR_TO_RDWR_BUF_OR_NULL;
 }
 
 static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
@@ -348,7 +427,9 @@
 	return type == PTR_TO_SOCKET ||
 		type == PTR_TO_SOCKET_OR_NULL ||
 		type == PTR_TO_TCP_SOCK ||
-		type == PTR_TO_TCP_SOCK_OR_NULL;
+		type == PTR_TO_TCP_SOCK_OR_NULL ||
+		type == PTR_TO_MEM ||
+		type == PTR_TO_MEM_OR_NULL;
 }
 
 static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
@@ -356,26 +437,63 @@
 	return type == ARG_PTR_TO_SOCK_COMMON;
 }
 
+static bool arg_type_may_be_null(enum bpf_arg_type type)
+{
+	return type == ARG_PTR_TO_MAP_VALUE_OR_NULL ||
+	       type == ARG_PTR_TO_MEM_OR_NULL ||
+	       type == ARG_PTR_TO_CTX_OR_NULL ||
+	       type == ARG_PTR_TO_SOCKET_OR_NULL ||
+	       type == ARG_PTR_TO_ALLOC_MEM_OR_NULL;
+}
+
 /* Determine whether the function releases some resources allocated by another
  * function call. The first reference type argument will be assumed to be
  * released by release_reference().
  */
 static bool is_release_function(enum bpf_func_id func_id)
 {
-	return func_id == BPF_FUNC_sk_release;
+	return func_id == BPF_FUNC_sk_release ||
+	       func_id == BPF_FUNC_ringbuf_submit ||
+	       func_id == BPF_FUNC_ringbuf_discard;
 }
 
-static bool is_acquire_function(enum bpf_func_id func_id)
+static bool may_be_acquire_function(enum bpf_func_id func_id)
 {
 	return func_id == BPF_FUNC_sk_lookup_tcp ||
 		func_id == BPF_FUNC_sk_lookup_udp ||
-		func_id == BPF_FUNC_skc_lookup_tcp;
+		func_id == BPF_FUNC_skc_lookup_tcp ||
+		func_id == BPF_FUNC_map_lookup_elem ||
+	        func_id == BPF_FUNC_ringbuf_reserve;
+}
+
+static bool is_acquire_function(enum bpf_func_id func_id,
+				const struct bpf_map *map)
+{
+	enum bpf_map_type map_type = map ? map->map_type : BPF_MAP_TYPE_UNSPEC;
+
+	if (func_id == BPF_FUNC_sk_lookup_tcp ||
+	    func_id == BPF_FUNC_sk_lookup_udp ||
+	    func_id == BPF_FUNC_skc_lookup_tcp ||
+	    func_id == BPF_FUNC_ringbuf_reserve)
+		return true;
+
+	if (func_id == BPF_FUNC_map_lookup_elem &&
+	    (map_type == BPF_MAP_TYPE_SOCKMAP ||
+	     map_type == BPF_MAP_TYPE_SOCKHASH))
+		return true;
+
+	return false;
 }
 
 static bool is_ptr_cast_function(enum bpf_func_id func_id)
 {
 	return func_id == BPF_FUNC_tcp_sock ||
-		func_id == BPF_FUNC_sk_fullsock;
+		func_id == BPF_FUNC_sk_fullsock ||
+		func_id == BPF_FUNC_skc_to_tcp_sock ||
+		func_id == BPF_FUNC_skc_to_tcp6_sock ||
+		func_id == BPF_FUNC_skc_to_udp6_sock ||
+		func_id == BPF_FUNC_skc_to_tcp_timewait_sock ||
+		func_id == BPF_FUNC_skc_to_tcp_request_sock;
 }
 
 /* string representation of 'enum bpf_reg_type' */
@@ -399,6 +517,15 @@
 	[PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null",
 	[PTR_TO_TP_BUFFER]	= "tp_buffer",
 	[PTR_TO_XDP_SOCK]	= "xdp_sock",
+	[PTR_TO_BTF_ID]		= "ptr_",
+	[PTR_TO_BTF_ID_OR_NULL]	= "ptr_or_null_",
+	[PTR_TO_PERCPU_BTF_ID]	= "percpu_ptr_",
+	[PTR_TO_MEM]		= "mem",
+	[PTR_TO_MEM_OR_NULL]	= "mem_or_null",
+	[PTR_TO_RDONLY_BUF]	= "rdonly_buf",
+	[PTR_TO_RDONLY_BUF_OR_NULL] = "rdonly_buf_or_null",
+	[PTR_TO_RDWR_BUF]	= "rdwr_buf",
+	[PTR_TO_RDWR_BUF_OR_NULL] = "rdwr_buf_or_null",
 };
 
 static char slot_type_char[] = {
@@ -429,6 +556,12 @@
 	return cur->frame[reg->frameno];
 }
 
+const char *kernel_type_name(u32 id)
+{
+	return btf_name_by_offset(btf_vmlinux,
+				  btf_type_by_id(btf_vmlinux, id)->name_off);
+}
+
 static void print_verifier_state(struct bpf_verifier_env *env,
 				 const struct bpf_func_state *state)
 {
@@ -453,6 +586,10 @@
 			/* reg->off should be 0 for SCALAR_VALUE */
 			verbose(env, "%lld", reg->var_off.value + reg->off);
 		} else {
+			if (t == PTR_TO_BTF_ID ||
+			    t == PTR_TO_BTF_ID_OR_NULL ||
+			    t == PTR_TO_PERCPU_BTF_ID)
+				verbose(env, "%s", kernel_type_name(reg->btf_id));
 			verbose(env, "(id=%d", reg->id);
 			if (reg_type_may_be_refcounted_or_null(t))
 				verbose(env, ",ref_obj_id=%d", reg->ref_obj_id);
@@ -493,6 +630,22 @@
 					tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
 					verbose(env, ",var_off=%s", tn_buf);
 				}
+				if (reg->s32_min_value != reg->smin_value &&
+				    reg->s32_min_value != S32_MIN)
+					verbose(env, ",s32_min_value=%d",
+						(int)(reg->s32_min_value));
+				if (reg->s32_max_value != reg->smax_value &&
+				    reg->s32_max_value != S32_MAX)
+					verbose(env, ",s32_max_value=%d",
+						(int)(reg->s32_max_value));
+				if (reg->u32_min_value != reg->umin_value &&
+				    reg->u32_min_value != U32_MIN)
+					verbose(env, ",u32_min_value=%d",
+						(int)(reg->u32_min_value));
+				if (reg->u32_max_value != reg->umax_value &&
+				    reg->u32_max_value != U32_MAX)
+					verbose(env, ",u32_max_value=%d",
+						(int)(reg->u32_max_value));
 			}
 			verbose(env, ")");
 		}
@@ -773,7 +926,7 @@
 }
 
 static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx,
-		     int *insn_idx)
+		     int *insn_idx, bool pop_log)
 {
 	struct bpf_verifier_state *cur = env->cur_state;
 	struct bpf_verifier_stack_elem *elem, *head = env->head;
@@ -787,6 +940,8 @@
 		if (err)
 			return err;
 	}
+	if (pop_log)
+		bpf_vlog_reset(&env->log, head->log_pos);
 	if (insn_idx)
 		*insn_idx = head->insn_idx;
 	if (prev_insn_idx)
@@ -814,6 +969,7 @@
 	elem->insn_idx = insn_idx;
 	elem->prev_insn_idx = prev_insn_idx;
 	elem->next = env->head;
+	elem->log_pos = env->log.len_used;
 	env->head = elem;
 	env->stack_size++;
 	err = copy_verifier_state(&elem->st, cur);
@@ -842,7 +998,7 @@
 	free_verifier_state(env->cur_state, true);
 	env->cur_state = NULL;
 	/* pop all elements and return */
-	while (!pop_stack(env, NULL, NULL));
+	while (!pop_stack(env, NULL, NULL, false));
 	return NULL;
 }
 
@@ -854,6 +1010,21 @@
 static void __mark_reg_not_init(const struct bpf_verifier_env *env,
 				struct bpf_reg_state *reg);
 
+/* This helper doesn't clear reg->id */
+static void ___mark_reg_known(struct bpf_reg_state *reg, u64 imm)
+{
+	reg->var_off = tnum_const(imm);
+	reg->smin_value = (s64)imm;
+	reg->smax_value = (s64)imm;
+	reg->umin_value = imm;
+	reg->umax_value = imm;
+
+	reg->s32_min_value = (s32)imm;
+	reg->s32_max_value = (s32)imm;
+	reg->u32_min_value = (u32)imm;
+	reg->u32_max_value = (u32)imm;
+}
+
 /* Mark the unknown part of a register (variable offset or scalar value) as
  * known to have the value @imm.
  */
@@ -862,11 +1033,16 @@
 	/* Clear id, off, and union(map_ptr, range) */
 	memset(((u8 *)reg) + sizeof(reg->type), 0,
 	       offsetof(struct bpf_reg_state, var_off) - sizeof(reg->type));
-	reg->var_off = tnum_const(imm);
-	reg->smin_value = (s64)imm;
-	reg->smax_value = (s64)imm;
-	reg->umin_value = imm;
-	reg->umax_value = imm;
+	___mark_reg_known(reg, imm);
+}
+
+static void __mark_reg32_known(struct bpf_reg_state *reg, u64 imm)
+{
+	reg->var_off = tnum_const_subreg(reg->var_off, imm);
+	reg->s32_min_value = (s32)imm;
+	reg->s32_max_value = (s32)imm;
+	reg->u32_min_value = (u32)imm;
+	reg->u32_max_value = (u32)imm;
 }
 
 /* Mark the 'variable offset' part of a register as zero.  This should be
@@ -921,8 +1097,52 @@
 	       tnum_equals_const(reg->var_off, 0);
 }
 
-/* Attempts to improve min/max values based on var_off information */
-static void __update_reg_bounds(struct bpf_reg_state *reg)
+/* Reset the min/max bounds of a register */
+static void __mark_reg_unbounded(struct bpf_reg_state *reg)
+{
+	reg->smin_value = S64_MIN;
+	reg->smax_value = S64_MAX;
+	reg->umin_value = 0;
+	reg->umax_value = U64_MAX;
+
+	reg->s32_min_value = S32_MIN;
+	reg->s32_max_value = S32_MAX;
+	reg->u32_min_value = 0;
+	reg->u32_max_value = U32_MAX;
+}
+
+static void __mark_reg64_unbounded(struct bpf_reg_state *reg)
+{
+	reg->smin_value = S64_MIN;
+	reg->smax_value = S64_MAX;
+	reg->umin_value = 0;
+	reg->umax_value = U64_MAX;
+}
+
+static void __mark_reg32_unbounded(struct bpf_reg_state *reg)
+{
+	reg->s32_min_value = S32_MIN;
+	reg->s32_max_value = S32_MAX;
+	reg->u32_min_value = 0;
+	reg->u32_max_value = U32_MAX;
+}
+
+static void __update_reg32_bounds(struct bpf_reg_state *reg)
+{
+	struct tnum var32_off = tnum_subreg(reg->var_off);
+
+	/* min signed is max(sign bit) | min(other bits) */
+	reg->s32_min_value = max_t(s32, reg->s32_min_value,
+			var32_off.value | (var32_off.mask & S32_MIN));
+	/* max signed is min(sign bit) | max(other bits) */
+	reg->s32_max_value = min_t(s32, reg->s32_max_value,
+			var32_off.value | (var32_off.mask & S32_MAX));
+	reg->u32_min_value = max_t(u32, reg->u32_min_value, (u32)var32_off.value);
+	reg->u32_max_value = min(reg->u32_max_value,
+				 (u32)(var32_off.value | var32_off.mask));
+}
+
+static void __update_reg64_bounds(struct bpf_reg_state *reg)
 {
 	/* min signed is max(sign bit) | min(other bits) */
 	reg->smin_value = max_t(s64, reg->smin_value,
@@ -935,8 +1155,48 @@
 			      reg->var_off.value | reg->var_off.mask);
 }
 
+static void __update_reg_bounds(struct bpf_reg_state *reg)
+{
+	__update_reg32_bounds(reg);
+	__update_reg64_bounds(reg);
+}
+
 /* Uses signed min/max values to inform unsigned, and vice-versa */
-static void __reg_deduce_bounds(struct bpf_reg_state *reg)
+static void __reg32_deduce_bounds(struct bpf_reg_state *reg)
+{
+	/* Learn sign from signed bounds.
+	 * If we cannot cross the sign boundary, then signed and unsigned bounds
+	 * are the same, so combine.  This works even in the negative case, e.g.
+	 * -3 s<= x s<= -1 implies 0xf...fd u<= x u<= 0xf...ff.
+	 */
+	if (reg->s32_min_value >= 0 || reg->s32_max_value < 0) {
+		reg->s32_min_value = reg->u32_min_value =
+			max_t(u32, reg->s32_min_value, reg->u32_min_value);
+		reg->s32_max_value = reg->u32_max_value =
+			min_t(u32, reg->s32_max_value, reg->u32_max_value);
+		return;
+	}
+	/* Learn sign from unsigned bounds.  Signed bounds cross the sign
+	 * boundary, so we must be careful.
+	 */
+	if ((s32)reg->u32_max_value >= 0) {
+		/* Positive.  We can't learn anything from the smin, but smax
+		 * is positive, hence safe.
+		 */
+		reg->s32_min_value = reg->u32_min_value;
+		reg->s32_max_value = reg->u32_max_value =
+			min_t(u32, reg->s32_max_value, reg->u32_max_value);
+	} else if ((s32)reg->u32_min_value < 0) {
+		/* Negative.  We can't learn anything from the smax, but smin
+		 * is negative, hence safe.
+		 */
+		reg->s32_min_value = reg->u32_min_value =
+			max_t(u32, reg->s32_min_value, reg->u32_min_value);
+		reg->s32_max_value = reg->u32_max_value;
+	}
+}
+
+static void __reg64_deduce_bounds(struct bpf_reg_state *reg)
 {
 	/* Learn sign from signed bounds.
 	 * If we cannot cross the sign boundary, then signed and unsigned bounds
@@ -970,21 +1230,108 @@
 	}
 }
 
+static void __reg_deduce_bounds(struct bpf_reg_state *reg)
+{
+	__reg32_deduce_bounds(reg);
+	__reg64_deduce_bounds(reg);
+}
+
 /* Attempts to improve var_off based on unsigned min/max information */
 static void __reg_bound_offset(struct bpf_reg_state *reg)
 {
-	reg->var_off = tnum_intersect(reg->var_off,
-				      tnum_range(reg->umin_value,
-						 reg->umax_value));
+	struct tnum var64_off = tnum_intersect(reg->var_off,
+					       tnum_range(reg->umin_value,
+							  reg->umax_value));
+	struct tnum var32_off = tnum_intersect(tnum_subreg(reg->var_off),
+						tnum_range(reg->u32_min_value,
+							   reg->u32_max_value));
+
+	reg->var_off = tnum_or(tnum_clear_subreg(var64_off), var32_off);
 }
 
-/* Reset the min/max bounds of a register */
-static void __mark_reg_unbounded(struct bpf_reg_state *reg)
+static bool __reg32_bound_s64(s32 a)
 {
-	reg->smin_value = S64_MIN;
-	reg->smax_value = S64_MAX;
-	reg->umin_value = 0;
-	reg->umax_value = U64_MAX;
+	return a >= 0 && a <= S32_MAX;
+}
+
+static void __reg_assign_32_into_64(struct bpf_reg_state *reg)
+{
+	reg->umin_value = reg->u32_min_value;
+	reg->umax_value = reg->u32_max_value;
+
+	/* Attempt to pull 32-bit signed bounds into 64-bit bounds but must
+	 * be positive otherwise set to worse case bounds and refine later
+	 * from tnum.
+	 */
+	if (__reg32_bound_s64(reg->s32_min_value) &&
+	    __reg32_bound_s64(reg->s32_max_value)) {
+		reg->smin_value = reg->s32_min_value;
+		reg->smax_value = reg->s32_max_value;
+	} else {
+		reg->smin_value = 0;
+		reg->smax_value = U32_MAX;
+	}
+}
+
+static void __reg_combine_32_into_64(struct bpf_reg_state *reg)
+{
+	/* special case when 64-bit register has upper 32-bit register
+	 * zeroed. Typically happens after zext or <<32, >>32 sequence
+	 * allowing us to use 32-bit bounds directly,
+	 */
+	if (tnum_equals_const(tnum_clear_subreg(reg->var_off), 0)) {
+		__reg_assign_32_into_64(reg);
+	} else {
+		/* Otherwise the best we can do is push lower 32bit known and
+		 * unknown bits into register (var_off set from jmp logic)
+		 * then learn as much as possible from the 64-bit tnum
+		 * known and unknown bits. The previous smin/smax bounds are
+		 * invalid here because of jmp32 compare so mark them unknown
+		 * so they do not impact tnum bounds calculation.
+		 */
+		__mark_reg64_unbounded(reg);
+		__update_reg_bounds(reg);
+	}
+
+	/* Intersecting with the old var_off might have improved our bounds
+	 * slightly.  e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
+	 * then new var_off is (0; 0x7f...fc) which improves our umax.
+	 */
+	__reg_deduce_bounds(reg);
+	__reg_bound_offset(reg);
+	__update_reg_bounds(reg);
+}
+
+static bool __reg64_bound_s32(s64 a)
+{
+	return a >= S32_MIN && a <= S32_MAX;
+}
+
+static bool __reg64_bound_u32(u64 a)
+{
+	return a >= U32_MIN && a <= U32_MAX;
+}
+
+static void __reg_combine_64_into_32(struct bpf_reg_state *reg)
+{
+	__mark_reg32_unbounded(reg);
+
+	if (__reg64_bound_s32(reg->smin_value) && __reg64_bound_s32(reg->smax_value)) {
+		reg->s32_min_value = (s32)reg->smin_value;
+		reg->s32_max_value = (s32)reg->smax_value;
+	}
+	if (__reg64_bound_u32(reg->umin_value) && __reg64_bound_u32(reg->umax_value)) {
+		reg->u32_min_value = (u32)reg->umin_value;
+		reg->u32_max_value = (u32)reg->umax_value;
+	}
+
+	/* Intersecting with the old var_off might have improved our bounds
+	 * slightly.  e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
+	 * then new var_off is (0; 0x7f...fc) which improves our umax.
+	 */
+	__reg_deduce_bounds(reg);
+	__reg_bound_offset(reg);
+	__update_reg_bounds(reg);
 }
 
 /* Mark a register as having a completely unknown (scalar) value. */
@@ -999,8 +1346,7 @@
 	reg->type = SCALAR_VALUE;
 	reg->var_off = tnum_unknown;
 	reg->frameno = 0;
-	reg->precise = env->subprog_cnt > 1 || !env->allow_ptr_leaks ?
-		       true : false;
+	reg->precise = env->subprog_cnt > 1 || !env->bpf_capable;
 	__mark_reg_unbounded(reg);
 }
 
@@ -1037,6 +1383,19 @@
 	__mark_reg_not_init(env, regs + regno);
 }
 
+static void mark_btf_ld_reg(struct bpf_verifier_env *env,
+			    struct bpf_reg_state *regs, u32 regno,
+			    enum bpf_reg_type reg_type, u32 btf_id)
+{
+	if (reg_type == SCALAR_VALUE) {
+		mark_reg_unknown(env, regs, regno);
+		return;
+	}
+	mark_reg_known_zero(env, regs, regno);
+	regs[regno].type = PTR_TO_BTF_ID;
+	regs[regno].btf_id = btf_id;
+}
+
 #define DEF_NOT_SUBREG	(0)
 static void init_reg_state(struct bpf_verifier_env *env,
 			   struct bpf_func_state *state)
@@ -1055,10 +1414,6 @@
 	regs[BPF_REG_FP].type = PTR_TO_STACK;
 	mark_reg_known_zero(env, regs, BPF_REG_FP);
 	regs[BPF_REG_FP].frameno = state->frameno;
-
-	/* 1st arg to a function */
-	regs[BPF_REG_1].type = PTR_TO_CTX;
-	mark_reg_known_zero(env, regs, BPF_REG_1);
 }
 
 #define BPF_MAIN_FUNC (-1)
@@ -1136,8 +1491,9 @@
 			continue;
 		if (insn[i].src_reg != BPF_PSEUDO_CALL)
 			continue;
-		if (!env->allow_ptr_leaks) {
-			verbose(env, "function calls to other bpf functions are allowed for root only\n");
+		if (!env->bpf_capable) {
+			verbose(env,
+				"function calls to other bpf functions are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
 			return -EPERM;
 		}
 		ret = add_subprog(env, i + insn[i].imm + 1);
@@ -1164,6 +1520,9 @@
 		    insn[i].imm == BPF_FUNC_tail_call &&
 		    insn[i].src_reg != BPF_PSEUDO_CALL)
 			subprog[cur_subprog].has_tail_call = true;
+		if (BPF_CLASS(code) == BPF_LD &&
+		    (BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND))
+			subprog[cur_subprog].has_ld_abs = true;
 		if (BPF_CLASS(code) != BPF_JMP && BPF_CLASS(code) != BPF_JMP32)
 			goto next;
 		if (BPF_OP(code) == BPF_EXIT || BPF_OP(code) == BPF_CALL)
@@ -1675,8 +2034,7 @@
 	bool new_marks = false;
 	int i, err;
 
-	if (!env->allow_ptr_leaks)
-		/* backtracking is root only for now */
+	if (!env->bpf_capable)
 		return 0;
 
 	func = st->frame[st->curframe];
@@ -1853,6 +2211,15 @@
 	case PTR_TO_TCP_SOCK:
 	case PTR_TO_TCP_SOCK_OR_NULL:
 	case PTR_TO_XDP_SOCK:
+	case PTR_TO_BTF_ID:
+	case PTR_TO_BTF_ID_OR_NULL:
+	case PTR_TO_RDONLY_BUF:
+	case PTR_TO_RDONLY_BUF_OR_NULL:
+	case PTR_TO_RDWR_BUF:
+	case PTR_TO_RDWR_BUF_OR_NULL:
+	case PTR_TO_PERCPU_BTF_ID:
+	case PTR_TO_MEM:
+	case PTR_TO_MEM_OR_NULL:
 		return true;
 	default:
 		return false;
@@ -1870,6 +2237,20 @@
 	return reg->type == SCALAR_VALUE && tnum_is_const(reg->var_off);
 }
 
+static bool __is_scalar_unbounded(struct bpf_reg_state *reg)
+{
+	return tnum_is_unknown(reg->var_off) &&
+	       reg->smin_value == S64_MIN && reg->smax_value == S64_MAX &&
+	       reg->umin_value == 0 && reg->umax_value == U64_MAX &&
+	       reg->s32_min_value == S32_MIN && reg->s32_max_value == S32_MAX &&
+	       reg->u32_min_value == 0 && reg->u32_max_value == U32_MAX;
+}
+
+static bool register_is_bounded(struct bpf_reg_state *reg)
+{
+	return reg->type == SCALAR_VALUE && !__is_scalar_unbounded(reg);
+}
+
 static bool __is_pointer_value(bool allow_ptr_leaks,
 			       const struct bpf_reg_state *reg)
 {
@@ -1891,12 +2272,14 @@
 		state->stack[spi].slot_type[i] = STACK_SPILL;
 }
 
-/* check_stack_read/write functions track spill/fill of registers,
+/* check_stack_{read,write}_fixed_off functions track spill/fill of registers,
  * stack boundary and alignment are checked in check_mem_access()
  */
-static int check_stack_write(struct bpf_verifier_env *env,
-			     struct bpf_func_state *state, /* func where register points to */
-			     int off, int size, int value_regno, int insn_idx)
+static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
+				       /* stack frame we're writing to */
+				       struct bpf_func_state *state,
+				       int off, int size, int value_regno,
+				       int insn_idx)
 {
 	struct bpf_func_state *cur; /* state of the current function */
 	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE, err;
@@ -1920,7 +2303,7 @@
 	cur = env->cur_state->frame[env->cur_state->curframe];
 	if (value_regno >= 0)
 		reg = &cur->regs[value_regno];
-	if (!env->allow_ptr_leaks) {
+	if (!env->bypass_spec_v4) {
 		bool sanitize = reg && is_spillable_regtype(reg->type);
 
 		for (i = 0; i < size; i++) {
@@ -1934,8 +2317,8 @@
 			env->insn_aux_data[insn_idx].sanitize_stack_spill = true;
 	}
 
-	if (reg && size == BPF_REG_SIZE && register_is_const(reg) &&
-	    !register_is_null(reg) && env->allow_ptr_leaks) {
+	if (reg && size == BPF_REG_SIZE && register_is_bounded(reg) &&
+	    !register_is_null(reg) && env->bpf_capable) {
 		if (dst_reg != BPF_REG_FP) {
 			/* The backtracking logic can only recognize explicit
 			 * stack slot address like [fp - 8]. Other spill of
@@ -1998,9 +2381,175 @@
 	return 0;
 }
 
-static int check_stack_read(struct bpf_verifier_env *env,
-			    struct bpf_func_state *reg_state /* func where register points to */,
-			    int off, int size, int value_regno)
+/* Write the stack: 'stack[ptr_regno + off] = value_regno'. 'ptr_regno' is
+ * known to contain a variable offset.
+ * This function checks whether the write is permitted and conservatively
+ * tracks the effects of the write, considering that each stack slot in the
+ * dynamic range is potentially written to.
+ *
+ * 'off' includes 'regno->off'.
+ * 'value_regno' can be -1, meaning that an unknown value is being written to
+ * the stack.
+ *
+ * Spilled pointers in range are not marked as written because we don't know
+ * what's going to be actually written. This means that read propagation for
+ * future reads cannot be terminated by this write.
+ *
+ * For privileged programs, uninitialized stack slots are considered
+ * initialized by this write (even though we don't know exactly what offsets
+ * are going to be written to). The idea is that we don't want the verifier to
+ * reject future reads that access slots written to through variable offsets.
+ */
+static int check_stack_write_var_off(struct bpf_verifier_env *env,
+				     /* func where register points to */
+				     struct bpf_func_state *state,
+				     int ptr_regno, int off, int size,
+				     int value_regno, int insn_idx)
+{
+	struct bpf_func_state *cur; /* state of the current function */
+	int min_off, max_off;
+	int i, err;
+	struct bpf_reg_state *ptr_reg = NULL, *value_reg = NULL;
+	bool writing_zero = false;
+	/* set if the fact that we're writing a zero is used to let any
+	 * stack slots remain STACK_ZERO
+	 */
+	bool zero_used = false;
+
+	cur = env->cur_state->frame[env->cur_state->curframe];
+	ptr_reg = &cur->regs[ptr_regno];
+	min_off = ptr_reg->smin_value + off;
+	max_off = ptr_reg->smax_value + off + size;
+	if (value_regno >= 0)
+		value_reg = &cur->regs[value_regno];
+	if (value_reg && register_is_null(value_reg))
+		writing_zero = true;
+
+	err = realloc_func_state(state, round_up(-min_off, BPF_REG_SIZE),
+				 state->acquired_refs, true);
+	if (err)
+		return err;
+
+
+	/* Variable offset writes destroy any spilled pointers in range. */
+	for (i = min_off; i < max_off; i++) {
+		u8 new_type, *stype;
+		int slot, spi;
+
+		slot = -i - 1;
+		spi = slot / BPF_REG_SIZE;
+		stype = &state->stack[spi].slot_type[slot % BPF_REG_SIZE];
+
+		if (!env->allow_ptr_leaks
+				&& *stype != NOT_INIT
+				&& *stype != SCALAR_VALUE) {
+			/* Reject the write if there's are spilled pointers in
+			 * range. If we didn't reject here, the ptr status
+			 * would be erased below (even though not all slots are
+			 * actually overwritten), possibly opening the door to
+			 * leaks.
+			 */
+			verbose(env, "spilled ptr in range of var-offset stack write; insn %d, ptr off: %d",
+				insn_idx, i);
+			return -EINVAL;
+		}
+
+		/* Erase all spilled pointers. */
+		state->stack[spi].spilled_ptr.type = NOT_INIT;
+
+		/* Update the slot type. */
+		new_type = STACK_MISC;
+		if (writing_zero && *stype == STACK_ZERO) {
+			new_type = STACK_ZERO;
+			zero_used = true;
+		}
+		/* If the slot is STACK_INVALID, we check whether it's OK to
+		 * pretend that it will be initialized by this write. The slot
+		 * might not actually be written to, and so if we mark it as
+		 * initialized future reads might leak uninitialized memory.
+		 * For privileged programs, we will accept such reads to slots
+		 * that may or may not be written because, if we're reject
+		 * them, the error would be too confusing.
+		 */
+		if (*stype == STACK_INVALID && !env->allow_uninit_stack) {
+			verbose(env, "uninit stack in range of var-offset write prohibited for !root; insn %d, off: %d",
+					insn_idx, i);
+			return -EINVAL;
+		}
+		*stype = new_type;
+	}
+	if (zero_used) {
+		/* backtracking doesn't work for STACK_ZERO yet. */
+		err = mark_chain_precision(env, value_regno);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+/* When register 'dst_regno' is assigned some values from stack[min_off,
+ * max_off), we set the register's type according to the types of the
+ * respective stack slots. If all the stack values are known to be zeros, then
+ * so is the destination reg. Otherwise, the register is considered to be
+ * SCALAR. This function does not deal with register filling; the caller must
+ * ensure that all spilled registers in the stack range have been marked as
+ * read.
+ */
+static void mark_reg_stack_read(struct bpf_verifier_env *env,
+				/* func where src register points to */
+				struct bpf_func_state *ptr_state,
+				int min_off, int max_off, int dst_regno)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	int i, slot, spi;
+	u8 *stype;
+	int zeros = 0;
+
+	for (i = min_off; i < max_off; i++) {
+		slot = -i - 1;
+		spi = slot / BPF_REG_SIZE;
+		stype = ptr_state->stack[spi].slot_type;
+		if (stype[slot % BPF_REG_SIZE] != STACK_ZERO)
+			break;
+		zeros++;
+	}
+	if (zeros == max_off - min_off) {
+		/* any access_size read into register is zero extended,
+		 * so the whole register == const_zero
+		 */
+		__mark_reg_const_zero(&state->regs[dst_regno]);
+		/* backtracking doesn't support STACK_ZERO yet,
+		 * so mark it precise here, so that later
+		 * backtracking can stop here.
+		 * Backtracking may not need this if this register
+		 * doesn't participate in pointer adjustment.
+		 * Forward propagation of precise flag is not
+		 * necessary either. This mark is only to stop
+		 * backtracking. Any register that contributed
+		 * to const 0 was marked precise before spill.
+		 */
+		state->regs[dst_regno].precise = true;
+	} else {
+		/* have read misc data from the stack */
+		mark_reg_unknown(env, state->regs, dst_regno);
+	}
+	state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
+}
+
+/* Read the stack at 'off' and put the results into the register indicated by
+ * 'dst_regno'. It handles reg filling if the addressed stack slot is a
+ * spilled reg.
+ *
+ * 'dst_regno' can be -1, meaning that the read value is not going to a
+ * register.
+ *
+ * The access is assumed to be within the current stack bounds.
+ */
+static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
+				      /* func where src register points to */
+				      struct bpf_func_state *reg_state,
+				      int off, int size, int dst_regno)
 {
 	struct bpf_verifier_state *vstate = env->cur_state;
 	struct bpf_func_state *state = vstate->frame[vstate->curframe];
@@ -2008,11 +2557,6 @@
 	struct bpf_reg_state *reg;
 	u8 *stype;
 
-	if (reg_state->allocated_stack <= slot) {
-		verbose(env, "invalid read from stack off %d+0 size %d\n",
-			off, size);
-		return -EACCES;
-	}
 	stype = reg_state->stack[spi].slot_type;
 	reg = &reg_state->stack[spi].spilled_ptr;
 
@@ -2023,9 +2567,9 @@
 				verbose(env, "invalid size of register fill\n");
 				return -EACCES;
 			}
-			if (value_regno >= 0) {
-				mark_reg_unknown(env, state->regs, value_regno);
-				state->regs[value_regno].live |= REG_LIVE_WRITTEN;
+			if (dst_regno >= 0) {
+				mark_reg_unknown(env, state->regs, dst_regno);
+				state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
 			}
 			mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
 			return 0;
@@ -2037,16 +2581,16 @@
 			}
 		}
 
-		if (value_regno >= 0) {
+		if (dst_regno >= 0) {
 			/* restore register state from stack */
-			state->regs[value_regno] = *reg;
+			state->regs[dst_regno] = *reg;
 			/* mark reg as written since spilled pointer state likely
 			 * has its liveness marks cleared by is_state_visited()
 			 * which resets stack/reg liveness for state transitions
 			 */
-			state->regs[value_regno].live |= REG_LIVE_WRITTEN;
+			state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
 		} else if (__is_pointer_value(env->allow_ptr_leaks, reg)) {
-			/* If value_regno==-1, the caller is asking us whether
+			/* If dst_regno==-1, the caller is asking us whether
 			 * it is acceptable to use this value as a SCALAR_VALUE
 			 * (e.g. for XADD).
 			 * We must not allow unprivileged callers to do that
@@ -2058,70 +2602,167 @@
 		}
 		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
 	} else {
-		int zeros = 0;
+		u8 type;
 
 		for (i = 0; i < size; i++) {
-			if (stype[(slot - i) % BPF_REG_SIZE] == STACK_MISC)
+			type = stype[(slot - i) % BPF_REG_SIZE];
+			if (type == STACK_MISC)
 				continue;
-			if (stype[(slot - i) % BPF_REG_SIZE] == STACK_ZERO) {
-				zeros++;
+			if (type == STACK_ZERO)
 				continue;
-			}
 			verbose(env, "invalid read from stack off %d+%d size %d\n",
 				off, i, size);
 			return -EACCES;
 		}
 		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
-		if (value_regno >= 0) {
-			if (zeros == size) {
-				/* any size read into register is zero extended,
-				 * so the whole register == const_zero
-				 */
-				__mark_reg_const_zero(&state->regs[value_regno]);
-				/* backtracking doesn't support STACK_ZERO yet,
-				 * so mark it precise here, so that later
-				 * backtracking can stop here.
-				 * Backtracking may not need this if this register
-				 * doesn't participate in pointer adjustment.
-				 * Forward propagation of precise flag is not
-				 * necessary either. This mark is only to stop
-				 * backtracking. Any register that contributed
-				 * to const 0 was marked precise before spill.
-				 */
-				state->regs[value_regno].precise = true;
-			} else {
-				/* have read misc data from the stack */
-				mark_reg_unknown(env, state->regs, value_regno);
-			}
-			state->regs[value_regno].live |= REG_LIVE_WRITTEN;
-		}
+		if (dst_regno >= 0)
+			mark_reg_stack_read(env, reg_state, off, off + size, dst_regno);
 	}
 	return 0;
 }
 
-static int check_stack_access(struct bpf_verifier_env *env,
-			      const struct bpf_reg_state *reg,
-			      int off, int size)
+enum stack_access_src {
+	ACCESS_DIRECT = 1,  /* the access is performed by an instruction */
+	ACCESS_HELPER = 2,  /* the access is performed by a helper */
+};
+
+static int check_stack_range_initialized(struct bpf_verifier_env *env,
+					 int regno, int off, int access_size,
+					 bool zero_size_allowed,
+					 enum stack_access_src type,
+					 struct bpf_call_arg_meta *meta);
+
+static struct bpf_reg_state *reg_state(struct bpf_verifier_env *env, int regno)
 {
-	/* Stack accesses must be at a fixed offset, so that we
-	 * can determine what type of data were returned. See
-	 * check_stack_read().
+	return cur_regs(env) + regno;
+}
+
+/* Read the stack at 'ptr_regno + off' and put the result into the register
+ * 'dst_regno'.
+ * 'off' includes the pointer register's fixed offset(i.e. 'ptr_regno.off'),
+ * but not its variable offset.
+ * 'size' is assumed to be <= reg size and the access is assumed to be aligned.
+ *
+ * As opposed to check_stack_read_fixed_off, this function doesn't deal with
+ * filling registers (i.e. reads of spilled register cannot be detected when
+ * the offset is not fixed). We conservatively mark 'dst_regno' as containing
+ * SCALAR_VALUE. That's why we assert that the 'ptr_regno' has a variable
+ * offset; for a fixed offset check_stack_read_fixed_off should be used
+ * instead.
+ */
+static int check_stack_read_var_off(struct bpf_verifier_env *env,
+				    int ptr_regno, int off, int size, int dst_regno)
+{
+	/* The state of the source register. */
+	struct bpf_reg_state *reg = reg_state(env, ptr_regno);
+	struct bpf_func_state *ptr_state = func(env, reg);
+	int err;
+	int min_off, max_off;
+
+	/* Note that we pass a NULL meta, so raw access will not be permitted.
 	 */
-	if (!tnum_is_const(reg->var_off)) {
+	err = check_stack_range_initialized(env, ptr_regno, off, size,
+					    false, ACCESS_DIRECT, NULL);
+	if (err)
+		return err;
+
+	min_off = reg->smin_value + off;
+	max_off = reg->smax_value + off;
+	mark_reg_stack_read(env, ptr_state, min_off, max_off + size, dst_regno);
+	return 0;
+}
+
+/* check_stack_read dispatches to check_stack_read_fixed_off or
+ * check_stack_read_var_off.
+ *
+ * The caller must ensure that the offset falls within the allocated stack
+ * bounds.
+ *
+ * 'dst_regno' is a register which will receive the value from the stack. It
+ * can be -1, meaning that the read value is not going to a register.
+ */
+static int check_stack_read(struct bpf_verifier_env *env,
+			    int ptr_regno, int off, int size,
+			    int dst_regno)
+{
+	struct bpf_reg_state *reg = reg_state(env, ptr_regno);
+	struct bpf_func_state *state = func(env, reg);
+	int err;
+	/* Some accesses are only permitted with a static offset. */
+	bool var_off = !tnum_is_const(reg->var_off);
+
+	/* The offset is required to be static when reads don't go to a
+	 * register, in order to not leak pointers (see
+	 * check_stack_read_fixed_off).
+	 */
+	if (dst_regno < 0 && var_off) {
 		char tn_buf[48];
 
 		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-		verbose(env, "variable stack access var_off=%s off=%d size=%d\n",
+		verbose(env, "variable offset stack pointer cannot be passed into helper function; var_off=%s off=%d size=%d\n",
 			tn_buf, off, size);
 		return -EACCES;
 	}
+	/* Variable offset is prohibited for unprivileged mode for simplicity
+	 * since it requires corresponding support in Spectre masking for stack
+	 * ALU. See also retrieve_ptr_limit().
+	 */
+	if (!env->bypass_spec_v1 && var_off) {
+		char tn_buf[48];
 
-	if (off >= 0 || off < -MAX_BPF_STACK) {
-		verbose(env, "invalid stack off=%d size=%d\n", off, size);
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env, "R%d variable offset stack access prohibited for !root, var_off=%s\n",
+				ptr_regno, tn_buf);
 		return -EACCES;
 	}
 
-	return 0;
+	if (!var_off) {
+		off += reg->var_off.value;
+		err = check_stack_read_fixed_off(env, state, off, size,
+						 dst_regno);
+	} else {
+		/* Variable offset stack reads need more conservative handling
+		 * than fixed offset ones. Note that dst_regno >= 0 on this
+		 * branch.
+		 */
+		err = check_stack_read_var_off(env, ptr_regno, off, size,
+					       dst_regno);
+	}
+	return err;
+}
+
+
+/* check_stack_write dispatches to check_stack_write_fixed_off or
+ * check_stack_write_var_off.
+ *
+ * 'ptr_regno' is the register used as a pointer into the stack.
+ * 'off' includes 'ptr_regno->off', but not its variable offset (if any).
+ * 'value_regno' is the register whose value we're writing to the stack. It can
+ * be -1, meaning that we're not writing from a register.
+ *
+ * The caller must ensure that the offset falls within the maximum stack size.
+ */
+static int check_stack_write(struct bpf_verifier_env *env,
+			     int ptr_regno, int off, int size,
+			     int value_regno, int insn_idx)
+{
+	struct bpf_reg_state *reg = reg_state(env, ptr_regno);
+	struct bpf_func_state *state = func(env, reg);
+	int err;
+
+	if (tnum_is_const(reg->var_off)) {
+		off += reg->var_off.value;
+		err = check_stack_write_fixed_off(env, state, off, size,
+						  value_regno, insn_idx);
+	} else {
+		/* Variable offset stack reads need more conservative handling
+		 * than fixed offset ones.
+		 */
+		err = check_stack_write_var_off(env, state,
+						ptr_regno, off, size,
+						value_regno, insn_idx);
+	}
+	return err;
 }
 
 static int check_map_access_type(struct bpf_verifier_env *env, u32 regno,
@@ -2146,32 +2787,49 @@
 	return 0;
 }
 
-/* check read/write into map element returned by bpf_map_lookup_elem() */
-static int __check_map_access(struct bpf_verifier_env *env, u32 regno, int off,
-			      int size, bool zero_size_allowed)
+/* check read/write into memory region (e.g., map value, ringbuf sample, etc) */
+static int __check_mem_access(struct bpf_verifier_env *env, int regno,
+			      int off, int size, u32 mem_size,
+			      bool zero_size_allowed)
 {
-	struct bpf_reg_state *regs = cur_regs(env);
-	struct bpf_map *map = regs[regno].map_ptr;
+	bool size_ok = size > 0 || (size == 0 && zero_size_allowed);
+	struct bpf_reg_state *reg;
 
-	if (off < 0 || size < 0 || (size == 0 && !zero_size_allowed) ||
-	    off + size > map->value_size) {
+	if (off >= 0 && size_ok && (u64)off + size <= mem_size)
+		return 0;
+
+	reg = &cur_regs(env)[regno];
+	switch (reg->type) {
+	case PTR_TO_MAP_VALUE:
 		verbose(env, "invalid access to map value, value_size=%d off=%d size=%d\n",
-			map->value_size, off, size);
-		return -EACCES;
+			mem_size, off, size);
+		break;
+	case PTR_TO_PACKET:
+	case PTR_TO_PACKET_META:
+	case PTR_TO_PACKET_END:
+		verbose(env, "invalid access to packet, off=%d size=%d, R%d(id=%d,off=%d,r=%d)\n",
+			off, size, regno, reg->id, off, mem_size);
+		break;
+	case PTR_TO_MEM:
+	default:
+		verbose(env, "invalid access to memory, mem_size=%u off=%d size=%d\n",
+			mem_size, off, size);
 	}
-	return 0;
+
+	return -EACCES;
 }
 
-/* check read/write into a map element with possible variable offset */
-static int check_map_access(struct bpf_verifier_env *env, u32 regno,
-			    int off, int size, bool zero_size_allowed)
+/* check read/write into a memory region with possible variable offset */
+static int check_mem_region_access(struct bpf_verifier_env *env, u32 regno,
+				   int off, int size, u32 mem_size,
+				   bool zero_size_allowed)
 {
 	struct bpf_verifier_state *vstate = env->cur_state;
 	struct bpf_func_state *state = vstate->frame[vstate->curframe];
 	struct bpf_reg_state *reg = &state->regs[regno];
 	int err;
 
-	/* We may have adjusted the register to this map value, so we
+	/* We may have adjusted the register pointing to memory region, so we
 	 * need to try adding each of min_value and max_value to off
 	 * to make sure our theoretical access will be safe.
 	 */
@@ -2192,10 +2850,10 @@
 			regno);
 		return -EACCES;
 	}
-	err = __check_map_access(env, regno, reg->smin_value + off, size,
-				 zero_size_allowed);
+	err = __check_mem_access(env, regno, reg->smin_value + off, size,
+				 mem_size, zero_size_allowed);
 	if (err) {
-		verbose(env, "R%d min value is outside of the array range\n",
+		verbose(env, "R%d min value is outside of the allowed memory range\n",
 			regno);
 		return err;
 	}
@@ -2205,18 +2863,38 @@
 	 * If reg->umax_value + off could overflow, treat that as unbounded too.
 	 */
 	if (reg->umax_value >= BPF_MAX_VAR_OFF) {
-		verbose(env, "R%d unbounded memory access, make sure to bounds check any array access into a map\n",
+		verbose(env, "R%d unbounded memory access, make sure to bounds check any such access\n",
 			regno);
 		return -EACCES;
 	}
-	err = __check_map_access(env, regno, reg->umax_value + off, size,
-				 zero_size_allowed);
-	if (err)
-		verbose(env, "R%d max value is outside of the array range\n",
+	err = __check_mem_access(env, regno, reg->umax_value + off, size,
+				 mem_size, zero_size_allowed);
+	if (err) {
+		verbose(env, "R%d max value is outside of the allowed memory range\n",
 			regno);
+		return err;
+	}
 
-	if (map_value_has_spin_lock(reg->map_ptr)) {
-		u32 lock = reg->map_ptr->spin_lock_off;
+	return 0;
+}
+
+/* check read/write into a map element with possible variable offset */
+static int check_map_access(struct bpf_verifier_env *env, u32 regno,
+			    int off, int size, bool zero_size_allowed)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *reg = &state->regs[regno];
+	struct bpf_map *map = reg->map_ptr;
+	int err;
+
+	err = check_mem_region_access(env, regno, off, size, map->value_size,
+				      zero_size_allowed);
+	if (err)
+		return err;
+
+	if (map_value_has_spin_lock(map)) {
+		u32 lock = map->spin_lock_off;
 
 		/* if any part of struct bpf_spin_lock can be touched by
 		 * load/store reject this program.
@@ -2234,11 +2912,18 @@
 
 #define MAX_PACKET_OFF 0xffff
 
+static enum bpf_prog_type resolve_prog_type(struct bpf_prog *prog)
+{
+	return prog->aux->dst_prog ? prog->aux->dst_prog->type : prog->type;
+}
+
 static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
 				       const struct bpf_call_arg_meta *meta,
 				       enum bpf_access_type t)
 {
-	switch (env->prog->type) {
+	enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
+
+	switch (prog_type) {
 	/* Program types only with direct read access go here! */
 	case BPF_PROG_TYPE_LWT_IN:
 	case BPF_PROG_TYPE_LWT_OUT:
@@ -2248,7 +2933,7 @@
 	case BPF_PROG_TYPE_CGROUP_SKB:
 		if (t == BPF_WRITE)
 			return false;
-		/* fallthrough */
+		fallthrough;
 
 	/* Program types with direct read + write access go here! */
 	case BPF_PROG_TYPE_SCHED_CLS:
@@ -2274,21 +2959,6 @@
 	}
 }
 
-static int __check_packet_access(struct bpf_verifier_env *env, u32 regno,
-				 int off, int size, bool zero_size_allowed)
-{
-	struct bpf_reg_state *regs = cur_regs(env);
-	struct bpf_reg_state *reg = &regs[regno];
-
-	if (off < 0 || size < 0 || (size == 0 && !zero_size_allowed) ||
-	    (u64)off + size > reg->range) {
-		verbose(env, "invalid access to packet, off=%d size=%d, R%d(id=%d,off=%d,r=%d)\n",
-			off, size, regno, reg->id, reg->off, reg->range);
-		return -EACCES;
-	}
-	return 0;
-}
-
 static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off,
 			       int size, bool zero_size_allowed)
 {
@@ -2309,16 +2979,17 @@
 			regno);
 		return -EACCES;
 	}
-	err = __check_packet_access(env, regno, off, size, zero_size_allowed);
+	err = __check_mem_access(env, regno, off, size, reg->range,
+				 zero_size_allowed);
 	if (err) {
 		verbose(env, "R%d offset is outside of the packet\n", regno);
 		return err;
 	}
 
-	/* __check_packet_access has made sure "off + size - 1" is within u16.
+	/* __check_mem_access has made sure "off + size - 1" is within u16.
 	 * reg->umax_value can't be bigger than MAX_PACKET_OFF which is 0xffff,
 	 * otherwise find_good_pkt_pointers would have refused to set range info
-	 * that __check_packet_access would have rejected this pkt access.
+	 * that __check_mem_access would have rejected this pkt access.
 	 * Therefore, "off + reg->umax_value + size - 1" won't overflow u32.
 	 */
 	env->prog->aux->max_pkt_offset =
@@ -2330,10 +3001,12 @@
 
 /* check access to 'struct bpf_context' fields.  Supports fixed offsets only */
 static int check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int off, int size,
-			    enum bpf_access_type t, enum bpf_reg_type *reg_type)
+			    enum bpf_access_type t, enum bpf_reg_type *reg_type,
+			    u32 *btf_id)
 {
 	struct bpf_insn_access_aux info = {
 		.reg_type = *reg_type,
+		.log = &env->log,
 	};
 
 	if (env->ops->is_valid_access &&
@@ -2347,7 +3020,10 @@
 		 */
 		*reg_type = info.reg_type;
 
-		env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size;
+		if (*reg_type == PTR_TO_BTF_ID || *reg_type == PTR_TO_BTF_ID_OR_NULL)
+			*btf_id = info.btf_id;
+		else
+			env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size;
 		/* remember the offset of last byte accessed in ctx */
 		if (env->prog->aux->max_ctx_offset < off + size)
 			env->prog->aux->max_ctx_offset = off + size;
@@ -2415,11 +3091,6 @@
 	return -EACCES;
 }
 
-static struct bpf_reg_state *reg_state(struct bpf_verifier_env *env, int regno)
-{
-	return cur_regs(env) + regno;
-}
-
 static bool is_pointer_value(struct bpf_verifier_env *env, int regno)
 {
 	return __is_pointer_value(env->allow_ptr_leaks, reg_state(env, regno));
@@ -2538,8 +3209,8 @@
 		break;
 	case PTR_TO_STACK:
 		pointer_desc = "stack ";
-		/* The stack spill tracking logic in check_stack_write()
-		 * and check_stack_read() relies on stack accesses being
+		/* The stack spill tracking logic in check_stack_write_fixed_off()
+		 * and check_stack_read_fixed_off() relies on stack accesses being
 		 * aligned.
 		 */
 		strict = true;
@@ -2588,8 +3259,10 @@
 	int depth = 0, frame = 0, idx = 0, i = 0, subprog_end;
 	struct bpf_subprog_info *subprog = env->subprog_info;
 	struct bpf_insn *insn = env->prog->insnsi;
+	bool tail_call_reachable = false;
 	int ret_insn[MAX_CALL_FRAMES];
 	int ret_prog[MAX_CALL_FRAMES];
+	int j;
 
 process_func:
 	/* protect against potential stack overflow that might happen when
@@ -2645,6 +3318,10 @@
 				  i);
 			return -EFAULT;
 		}
+
+		if (subprog[idx].has_tail_call)
+			tail_call_reachable = true;
+
 		frame++;
 		if (frame >= MAX_CALL_FRAMES) {
 			verbose(env, "the call stack of %d frames is too deep !\n",
@@ -2653,6 +3330,17 @@
 		}
 		goto process_func;
 	}
+	/* if tail call got detected across bpf2bpf calls then mark each of the
+	 * currently present subprog frames as tail call reachable subprogs;
+	 * this info will be utilized by JIT so that we will be preserving the
+	 * tail call counter throughout bpf2bpf calls combined with tailcalls
+	 */
+	if (tail_call_reachable)
+		for (j = 0; j < frame; j++)
+			subprog[ret_prog[j]].tail_call_reachable = true;
+	if (subprog[0].tail_call_reachable)
+		env->prog->aux->tail_call_reachable = true;
+
 	/* end of for() loop means the last insn of the 'subprog'
 	 * was reached. Doesn't matter whether it was JA or EXIT
 	 */
@@ -2681,8 +3369,8 @@
 }
 #endif
 
-static int check_ctx_reg(struct bpf_verifier_env *env,
-			 const struct bpf_reg_state *reg, int regno)
+int check_ctx_reg(struct bpf_verifier_env *env,
+		  const struct bpf_reg_state *reg, int regno)
 {
 	/* Access to ctx or passing it to a helper is only allowed in
 	 * its original, unmodified form.
@@ -2705,14 +3393,15 @@
 	return 0;
 }
 
-static int check_tp_buffer_access(struct bpf_verifier_env *env,
-				  const struct bpf_reg_state *reg,
-				  int regno, int off, int size)
+static int __check_buffer_access(struct bpf_verifier_env *env,
+				 const char *buf_info,
+				 const struct bpf_reg_state *reg,
+				 int regno, int off, int size)
 {
 	if (off < 0) {
 		verbose(env,
-			"R%d invalid tracepoint buffer access: off=%d, size=%d",
-			regno, off, size);
+			"R%d invalid %s buffer access: off=%d, size=%d\n",
+			regno, buf_info, off, size);
 		return -EACCES;
 	}
 	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
@@ -2720,16 +3409,55 @@
 
 		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
 		verbose(env,
-			"R%d invalid variable buffer offset: off=%d, var_off=%s",
+			"R%d invalid variable buffer offset: off=%d, var_off=%s\n",
 			regno, off, tn_buf);
 		return -EACCES;
 	}
+
+	return 0;
+}
+
+static int check_tp_buffer_access(struct bpf_verifier_env *env,
+				  const struct bpf_reg_state *reg,
+				  int regno, int off, int size)
+{
+	int err;
+
+	err = __check_buffer_access(env, "tracepoint", reg, regno, off, size);
+	if (err)
+		return err;
+
 	if (off + size > env->prog->aux->max_tp_access)
 		env->prog->aux->max_tp_access = off + size;
 
 	return 0;
 }
 
+static int check_buffer_access(struct bpf_verifier_env *env,
+			       const struct bpf_reg_state *reg,
+			       int regno, int off, int size,
+			       bool zero_size_allowed,
+			       const char *buf_info,
+			       u32 *max_access)
+{
+	int err;
+
+	err = __check_buffer_access(env, buf_info, reg, regno, off, size);
+	if (err)
+		return err;
+
+	if (off + size > *max_access)
+		*max_access = off + size;
+
+	return 0;
+}
+
+/* BPF architecture zero extends alu32 ops into 64-bit registesr */
+static void zext_32_to_64(struct bpf_reg_state *reg)
+{
+	reg->var_off = tnum_subreg(reg->var_off);
+	__reg_assign_32_into_64(reg);
+}
 
 /* truncate register to smaller size (in bytes)
  * must be called with size < BPF_REG_SIZE
@@ -2752,11 +3480,34 @@
 	}
 	reg->smin_value = reg->umin_value;
 	reg->smax_value = reg->umax_value;
+
+	/* If size is smaller than 32bit register the 32bit register
+	 * values are also truncated so we push 64-bit bounds into
+	 * 32-bit bounds. Above were truncated < 32-bits already.
+	 */
+	if (size >= 4)
+		return;
+	__reg_combine_64_into_32(reg);
 }
 
 static bool bpf_map_is_rdonly(const struct bpf_map *map)
 {
-	return (map->map_flags & BPF_F_RDONLY_PROG) && map->frozen;
+	/* A map is considered read-only if the following condition are true:
+	 *
+	 * 1) BPF program side cannot change any of the map content. The
+	 *    BPF_F_RDONLY_PROG flag is throughout the lifetime of a map
+	 *    and was set at map creation time.
+	 * 2) The map value(s) have been initialized from user space by a
+	 *    loader and then "frozen", such that no new map update/delete
+	 *    operations from syscall side are possible for the rest of
+	 *    the map's lifetime from that point onwards.
+	 * 3) Any parallel/pending map update/delete operations from syscall
+	 *    side have been completed. Only after that point, it's safe to
+	 *    assume that map value(s) are immutable.
+	 */
+	return (map->map_flags & BPF_F_RDONLY_PROG) &&
+	       READ_ONCE(map->frozen) &&
+	       !bpf_map_write_active(map);
 }
 
 static int bpf_map_direct_read(struct bpf_map *map, int off, int size, u64 *val)
@@ -2789,6 +3540,197 @@
 	return 0;
 }
 
+static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
+				   struct bpf_reg_state *regs,
+				   int regno, int off, int size,
+				   enum bpf_access_type atype,
+				   int value_regno)
+{
+	struct bpf_reg_state *reg = regs + regno;
+	const struct btf_type *t = btf_type_by_id(btf_vmlinux, reg->btf_id);
+	const char *tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+	u32 btf_id;
+	int ret;
+
+	if (off < 0) {
+		verbose(env,
+			"R%d is ptr_%s invalid negative access: off=%d\n",
+			regno, tname, off);
+		return -EACCES;
+	}
+	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env,
+			"R%d is ptr_%s invalid variable offset: off=%d, var_off=%s\n",
+			regno, tname, off, tn_buf);
+		return -EACCES;
+	}
+
+	if (env->ops->btf_struct_access) {
+		ret = env->ops->btf_struct_access(&env->log, t, off, size,
+						  atype, &btf_id);
+	} else {
+		if (atype != BPF_READ) {
+			verbose(env, "only read is supported\n");
+			return -EACCES;
+		}
+
+		ret = btf_struct_access(&env->log, t, off, size, atype,
+					&btf_id);
+	}
+
+	if (ret < 0)
+		return ret;
+
+	if (atype == BPF_READ && value_regno >= 0)
+		mark_btf_ld_reg(env, regs, value_regno, ret, btf_id);
+
+	return 0;
+}
+
+static int check_ptr_to_map_access(struct bpf_verifier_env *env,
+				   struct bpf_reg_state *regs,
+				   int regno, int off, int size,
+				   enum bpf_access_type atype,
+				   int value_regno)
+{
+	struct bpf_reg_state *reg = regs + regno;
+	struct bpf_map *map = reg->map_ptr;
+	const struct btf_type *t;
+	const char *tname;
+	u32 btf_id;
+	int ret;
+
+	if (!btf_vmlinux) {
+		verbose(env, "map_ptr access not supported without CONFIG_DEBUG_INFO_BTF\n");
+		return -ENOTSUPP;
+	}
+
+	if (!map->ops->map_btf_id || !*map->ops->map_btf_id) {
+		verbose(env, "map_ptr access not supported for map type %d\n",
+			map->map_type);
+		return -ENOTSUPP;
+	}
+
+	t = btf_type_by_id(btf_vmlinux, *map->ops->map_btf_id);
+	tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+
+	if (!env->allow_ptr_to_map_access) {
+		verbose(env,
+			"%s access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN\n",
+			tname);
+		return -EPERM;
+	}
+
+	if (off < 0) {
+		verbose(env, "R%d is %s invalid negative access: off=%d\n",
+			regno, tname, off);
+		return -EACCES;
+	}
+
+	if (atype != BPF_READ) {
+		verbose(env, "only read from %s is supported\n", tname);
+		return -EACCES;
+	}
+
+	ret = btf_struct_access(&env->log, t, off, size, atype, &btf_id);
+	if (ret < 0)
+		return ret;
+
+	if (value_regno >= 0)
+		mark_btf_ld_reg(env, regs, value_regno, ret, btf_id);
+
+	return 0;
+}
+
+/* Check that the stack access at the given offset is within bounds. The
+ * maximum valid offset is -1.
+ *
+ * The minimum valid offset is -MAX_BPF_STACK for writes, and
+ * -state->allocated_stack for reads.
+ */
+static int check_stack_slot_within_bounds(int off,
+					  struct bpf_func_state *state,
+					  enum bpf_access_type t)
+{
+	int min_valid_off;
+
+	if (t == BPF_WRITE)
+		min_valid_off = -MAX_BPF_STACK;
+	else
+		min_valid_off = -state->allocated_stack;
+
+	if (off < min_valid_off || off > -1)
+		return -EACCES;
+	return 0;
+}
+
+/* Check that the stack access at 'regno + off' falls within the maximum stack
+ * bounds.
+ *
+ * 'off' includes `regno->offset`, but not its dynamic part (if any).
+ */
+static int check_stack_access_within_bounds(
+		struct bpf_verifier_env *env,
+		int regno, int off, int access_size,
+		enum stack_access_src src, enum bpf_access_type type)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_reg_state *reg = regs + regno;
+	struct bpf_func_state *state = func(env, reg);
+	int min_off, max_off;
+	int err;
+	char *err_extra;
+
+	if (src == ACCESS_HELPER)
+		/* We don't know if helpers are reading or writing (or both). */
+		err_extra = " indirect access to";
+	else if (type == BPF_READ)
+		err_extra = " read from";
+	else
+		err_extra = " write to";
+
+	if (tnum_is_const(reg->var_off)) {
+		min_off = reg->var_off.value + off;
+		if (access_size > 0)
+			max_off = min_off + access_size - 1;
+		else
+			max_off = min_off;
+	} else {
+		if (reg->smax_value >= BPF_MAX_VAR_OFF ||
+		    reg->smin_value <= -BPF_MAX_VAR_OFF) {
+			verbose(env, "invalid unbounded variable-offset%s stack R%d\n",
+				err_extra, regno);
+			return -EACCES;
+		}
+		min_off = reg->smin_value + off;
+		if (access_size > 0)
+			max_off = reg->smax_value + off + access_size - 1;
+		else
+			max_off = min_off;
+	}
+
+	err = check_stack_slot_within_bounds(min_off, state, type);
+	if (!err)
+		err = check_stack_slot_within_bounds(max_off, state, type);
+
+	if (err) {
+		if (tnum_is_const(reg->var_off)) {
+			verbose(env, "invalid%s stack R%d off=%d size=%d\n",
+				err_extra, regno, off, access_size);
+		} else {
+			char tn_buf[48];
+
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "invalid variable-offset%s stack R%d var_off=%s size=%d\n",
+				err_extra, regno, tn_buf, access_size);
+		}
+	}
+	return err;
+}
+
 /* check whether memory at (regno + off) is accessible for t = (read | write)
  * if t==write, value_regno is a register which value is stored into memory
  * if t==read, value_regno is a register which will receive the value from memory
@@ -2847,8 +3789,19 @@
 				mark_reg_unknown(env, regs, value_regno);
 			}
 		}
+	} else if (reg->type == PTR_TO_MEM) {
+		if (t == BPF_WRITE && value_regno >= 0 &&
+		    is_pointer_value(env, value_regno)) {
+			verbose(env, "R%d leaks addr into mem\n", value_regno);
+			return -EACCES;
+		}
+		err = check_mem_region_access(env, regno, off, size,
+					      reg->mem_size, false);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
 	} else if (reg->type == PTR_TO_CTX) {
 		enum bpf_reg_type reg_type = SCALAR_VALUE;
+		u32 btf_id = 0;
 
 		if (t == BPF_WRITE && value_regno >= 0 &&
 		    is_pointer_value(env, value_regno)) {
@@ -2860,7 +3813,9 @@
 		if (err < 0)
 			return err;
 
-		err = check_ctx_access(env, insn_idx, off, size, t, &reg_type);
+		err = check_ctx_access(env, insn_idx, off, size, t, &reg_type, &btf_id);
+		if (err)
+			verbose_linfo(env, insn_idx, "; ");
 		if (!err && t == BPF_READ && value_regno >= 0) {
 			/* ctx access returns either a scalar, or a
 			 * PTR_TO_PACKET[_META,_END]. In the latter
@@ -2879,13 +3834,16 @@
 				 * a sub-register.
 				 */
 				regs[value_regno].subreg_def = DEF_NOT_SUBREG;
+				if (reg_type == PTR_TO_BTF_ID ||
+				    reg_type == PTR_TO_BTF_ID_OR_NULL)
+					regs[value_regno].btf_id = btf_id;
 			}
 			regs[value_regno].type = reg_type;
 		}
 
 	} else if (reg->type == PTR_TO_STACK) {
-		off += reg->var_off.value;
-		err = check_stack_access(env, reg, off, size);
+		/* Basic bounds checks. */
+		err = check_stack_access_within_bounds(env, regno, off, size, ACCESS_DIRECT, t);
 		if (err)
 			return err;
 
@@ -2894,12 +3852,12 @@
 		if (err)
 			return err;
 
-		if (t == BPF_WRITE)
-			err = check_stack_write(env, state, off, size,
-						value_regno, insn_idx);
-		else
-			err = check_stack_read(env, state, off, size,
+		if (t == BPF_READ)
+			err = check_stack_read(env, regno, off, size,
 					       value_regno);
+		else
+			err = check_stack_write(env, regno, off, size,
+						value_regno, insn_idx);
 	} else if (reg_is_pkt_pointer(reg)) {
 		if (t == BPF_WRITE && !may_access_direct_pkt_data(env, NULL, t)) {
 			verbose(env, "cannot write into packet\n");
@@ -2938,6 +3896,29 @@
 		err = check_tp_buffer_access(env, reg, regno, off, size);
 		if (!err && t == BPF_READ && value_regno >= 0)
 			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_BTF_ID) {
+		err = check_ptr_to_btf_access(env, regs, regno, off, size, t,
+					      value_regno);
+	} else if (reg->type == CONST_PTR_TO_MAP) {
+		err = check_ptr_to_map_access(env, regs, regno, off, size, t,
+					      value_regno);
+	} else if (reg->type == PTR_TO_RDONLY_BUF) {
+		if (t == BPF_WRITE) {
+			verbose(env, "R%d cannot write into %s\n",
+				regno, reg_type_str[reg->type]);
+			return -EACCES;
+		}
+		err = check_buffer_access(env, reg, regno, off, size, false,
+					  "rdonly",
+					  &env->prog->aux->max_rdonly_access);
+		if (!err && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_RDWR_BUF) {
+		err = check_buffer_access(env, reg, regno, off, size, false,
+					  "rdwr",
+					  &env->prog->aux->max_rdwr_access);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
 	} else {
 		verbose(env, "R%d invalid mem access '%s'\n", regno,
 			reg_type_str[reg->type]);
@@ -2998,73 +3979,65 @@
 				BPF_SIZE(insn->code), BPF_WRITE, -1, true);
 }
 
-static int __check_stack_boundary(struct bpf_verifier_env *env, u32 regno,
-				  int off, int access_size,
-				  bool zero_size_allowed)
-{
-	struct bpf_reg_state *reg = reg_state(env, regno);
-
-	if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
-	    access_size < 0 || (access_size == 0 && !zero_size_allowed)) {
-		if (tnum_is_const(reg->var_off)) {
-			verbose(env, "invalid stack type R%d off=%d access_size=%d\n",
-				regno, off, access_size);
-		} else {
-			char tn_buf[48];
-
-			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-			verbose(env, "invalid stack type R%d var_off=%s access_size=%d\n",
-				regno, tn_buf, access_size);
-		}
-		return -EACCES;
-	}
-	return 0;
-}
-
-/* when register 'regno' is passed into function that will read 'access_size'
- * bytes from that pointer, make sure that it's within stack boundary
- * and all elements of stack are initialized.
- * Unlike most pointer bounds-checking functions, this one doesn't take an
- * 'off' argument, so it has to add in reg->off itself.
+/* When register 'regno' is used to read the stack (either directly or through
+ * a helper function) make sure that it's within stack boundary and, depending
+ * on the access type, that all elements of the stack are initialized.
+ *
+ * 'off' includes 'regno->off', but not its dynamic part (if any).
+ *
+ * All registers that have been spilled on the stack in the slots within the
+ * read offsets are marked as read.
  */
-static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
-				int access_size, bool zero_size_allowed,
-				struct bpf_call_arg_meta *meta)
+static int check_stack_range_initialized(
+		struct bpf_verifier_env *env, int regno, int off,
+		int access_size, bool zero_size_allowed,
+		enum stack_access_src type, struct bpf_call_arg_meta *meta)
 {
 	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_func_state *state = func(env, reg);
 	int err, min_off, max_off, i, j, slot, spi;
+	char *err_extra = type == ACCESS_HELPER ? " indirect" : "";
+	enum bpf_access_type bounds_check_type;
+	/* Some accesses can write anything into the stack, others are
+	 * read-only.
+	 */
+	bool clobber = false;
 
-	if (reg->type != PTR_TO_STACK) {
-		/* Allow zero-byte read from NULL, regardless of pointer type */
-		if (zero_size_allowed && access_size == 0 &&
-		    register_is_null(reg))
-			return 0;
-
-		verbose(env, "R%d type=%s expected=%s\n", regno,
-			reg_type_str[reg->type],
-			reg_type_str[PTR_TO_STACK]);
+	if (access_size == 0 && !zero_size_allowed) {
+		verbose(env, "invalid zero-sized read\n");
 		return -EACCES;
 	}
 
+	if (type == ACCESS_HELPER) {
+		/* The bounds checks for writes are more permissive than for
+		 * reads. However, if raw_mode is not set, we'll do extra
+		 * checks below.
+		 */
+		bounds_check_type = BPF_WRITE;
+		clobber = true;
+	} else {
+		bounds_check_type = BPF_READ;
+	}
+	err = check_stack_access_within_bounds(env, regno, off, access_size,
+					       type, bounds_check_type);
+	if (err)
+		return err;
+
+
 	if (tnum_is_const(reg->var_off)) {
-		min_off = max_off = reg->var_off.value + reg->off;
-		err = __check_stack_boundary(env, regno, min_off, access_size,
-					     zero_size_allowed);
-		if (err)
-			return err;
+		min_off = max_off = reg->var_off.value + off;
 	} else {
 		/* Variable offset is prohibited for unprivileged mode for
 		 * simplicity since it requires corresponding support in
 		 * Spectre masking for stack ALU.
 		 * See also retrieve_ptr_limit().
 		 */
-		if (!env->allow_ptr_leaks) {
+		if (!env->bypass_spec_v1) {
 			char tn_buf[48];
 
 			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-			verbose(env, "R%d indirect variable offset stack access prohibited for !root, var_off=%s\n",
-				regno, tn_buf);
+			verbose(env, "R%d%s variable offset stack access prohibited for !root, var_off=%s\n",
+				regno, err_extra, tn_buf);
 			return -EACCES;
 		}
 		/* Only initialized buffer on stack is allowed to be accessed
@@ -3076,28 +4049,8 @@
 		if (meta && meta->raw_mode)
 			meta = NULL;
 
-		if (reg->smax_value >= BPF_MAX_VAR_OFF ||
-		    reg->smax_value <= -BPF_MAX_VAR_OFF) {
-			verbose(env, "R%d unbounded indirect variable offset stack access\n",
-				regno);
-			return -EACCES;
-		}
-		min_off = reg->smin_value + reg->off;
-		max_off = reg->smax_value + reg->off;
-		err = __check_stack_boundary(env, regno, min_off, access_size,
-					     zero_size_allowed);
-		if (err) {
-			verbose(env, "R%d min value is outside of stack bound\n",
-				regno);
-			return err;
-		}
-		err = __check_stack_boundary(env, regno, max_off, access_size,
-					     zero_size_allowed);
-		if (err) {
-			verbose(env, "R%d max value is outside of stack bound\n",
-				regno);
-			return err;
-		}
+		min_off = reg->smin_value + off;
+		max_off = reg->smax_value + off;
 	}
 
 	if (meta && meta->raw_mode) {
@@ -3117,28 +4070,38 @@
 		if (*stype == STACK_MISC)
 			goto mark;
 		if (*stype == STACK_ZERO) {
-			/* helper can write anything into the stack */
-			*stype = STACK_MISC;
+			if (clobber) {
+				/* helper can write anything into the stack */
+				*stype = STACK_MISC;
+			}
 			goto mark;
 		}
+
 		if (state->stack[spi].slot_type[0] == STACK_SPILL &&
-		    state->stack[spi].spilled_ptr.type == SCALAR_VALUE) {
-			__mark_reg_unknown(env, &state->stack[spi].spilled_ptr);
-			for (j = 0; j < BPF_REG_SIZE; j++)
-				state->stack[spi].slot_type[j] = STACK_MISC;
+		    state->stack[spi].spilled_ptr.type == PTR_TO_BTF_ID)
+			goto mark;
+
+		if (state->stack[spi].slot_type[0] == STACK_SPILL &&
+		    (state->stack[spi].spilled_ptr.type == SCALAR_VALUE ||
+		     env->allow_ptr_leaks)) {
+			if (clobber) {
+				__mark_reg_unknown(env, &state->stack[spi].spilled_ptr);
+				for (j = 0; j < BPF_REG_SIZE; j++)
+					state->stack[spi].slot_type[j] = STACK_MISC;
+			}
 			goto mark;
 		}
 
 err:
 		if (tnum_is_const(reg->var_off)) {
-			verbose(env, "invalid indirect read from stack off %d+%d size %d\n",
-				min_off, i - min_off, access_size);
+			verbose(env, "invalid%s read from stack R%d off %d+%d size %d\n",
+				err_extra, regno, min_off, i - min_off, access_size);
 		} else {
 			char tn_buf[48];
 
 			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-			verbose(env, "invalid indirect read from stack var_off %s+%d size %d\n",
-				tn_buf, i - min_off, access_size);
+			verbose(env, "invalid%s read from stack R%d var_off %s+%d size %d\n",
+				err_extra, regno, tn_buf, i - min_off, access_size);
 		}
 		return -EACCES;
 mark:
@@ -3170,9 +4133,37 @@
 			return -EACCES;
 		return check_map_access(env, regno, reg->off, access_size,
 					zero_size_allowed);
-	default: /* scalar_value|ptr_to_stack or invalid ptr */
-		return check_stack_boundary(env, regno, access_size,
-					    zero_size_allowed, meta);
+	case PTR_TO_MEM:
+		return check_mem_region_access(env, regno, reg->off,
+					       access_size, reg->mem_size,
+					       zero_size_allowed);
+	case PTR_TO_RDONLY_BUF:
+		if (meta && meta->raw_mode)
+			return -EACCES;
+		return check_buffer_access(env, reg, regno, reg->off,
+					   access_size, zero_size_allowed,
+					   "rdonly",
+					   &env->prog->aux->max_rdonly_access);
+	case PTR_TO_RDWR_BUF:
+		return check_buffer_access(env, reg, regno, reg->off,
+					   access_size, zero_size_allowed,
+					   "rdwr",
+					   &env->prog->aux->max_rdwr_access);
+	case PTR_TO_STACK:
+		return check_stack_range_initialized(
+				env,
+				regno, reg->off, access_size,
+				zero_size_allowed, ACCESS_HELPER, meta);
+	default: /* scalar_value or invalid ptr */
+		/* Allow zero-byte read from NULL, regardless of pointer type */
+		if (zero_size_allowed && access_size == 0 &&
+		    register_is_null(reg))
+			return 0;
+
+		verbose(env, "R%d type=%s expected=%s\n", regno,
+			reg_type_str[reg->type],
+			reg_type_str[PTR_TO_STACK]);
+		return -EACCES;
 	}
 }
 
@@ -3204,10 +4195,6 @@
 	struct bpf_map *map = reg->map_ptr;
 	u64 val = reg->var_off.value;
 
-	if (reg->type != PTR_TO_MAP_VALUE) {
-		verbose(env, "R%d is not a pointer to map_value\n", regno);
-		return -EINVAL;
-	}
 	if (!is_const) {
 		verbose(env,
 			"R%d doesn't have constant offset. bpf_spin_lock has to be at the constant offset\n",
@@ -3274,6 +4261,11 @@
 	       type == ARG_CONST_SIZE_OR_ZERO;
 }
 
+static bool arg_type_is_alloc_size(enum bpf_arg_type type)
+{
+	return type == ARG_CONST_ALLOC_SIZE_OR_ZERO;
+}
+
 static bool arg_type_is_int_ptr(enum bpf_arg_type type)
 {
 	return type == ARG_PTR_TO_INT ||
@@ -3290,12 +4282,194 @@
 	return -EINVAL;
 }
 
-static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
+static int resolve_map_arg_type(struct bpf_verifier_env *env,
+				 const struct bpf_call_arg_meta *meta,
+				 enum bpf_arg_type *arg_type)
+{
+	if (!meta->map_ptr) {
+		/* kernel subsystem misconfigured verifier */
+		verbose(env, "invalid map_ptr to access map->type\n");
+		return -EACCES;
+	}
+
+	switch (meta->map_ptr->map_type) {
+	case BPF_MAP_TYPE_SOCKMAP:
+	case BPF_MAP_TYPE_SOCKHASH:
+		if (*arg_type == ARG_PTR_TO_MAP_VALUE) {
+			*arg_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON;
+		} else {
+			verbose(env, "invalid arg_type for sockmap/sockhash\n");
+			return -EINVAL;
+		}
+		break;
+
+	default:
+		break;
+	}
+	return 0;
+}
+
+struct bpf_reg_types {
+	const enum bpf_reg_type types[10];
+	u32 *btf_id;
+};
+
+static const struct bpf_reg_types map_key_value_types = {
+	.types = {
+		PTR_TO_STACK,
+		PTR_TO_PACKET,
+		PTR_TO_PACKET_META,
+		PTR_TO_MAP_VALUE,
+	},
+};
+
+static const struct bpf_reg_types sock_types = {
+	.types = {
+		PTR_TO_SOCK_COMMON,
+		PTR_TO_SOCKET,
+		PTR_TO_TCP_SOCK,
+		PTR_TO_XDP_SOCK,
+	},
+};
+
+#ifdef CONFIG_NET
+static const struct bpf_reg_types btf_id_sock_common_types = {
+	.types = {
+		PTR_TO_SOCK_COMMON,
+		PTR_TO_SOCKET,
+		PTR_TO_TCP_SOCK,
+		PTR_TO_XDP_SOCK,
+		PTR_TO_BTF_ID,
+	},
+	.btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
+};
+#endif
+
+static const struct bpf_reg_types mem_types = {
+	.types = {
+		PTR_TO_STACK,
+		PTR_TO_PACKET,
+		PTR_TO_PACKET_META,
+		PTR_TO_MAP_VALUE,
+		PTR_TO_MEM,
+		PTR_TO_RDONLY_BUF,
+		PTR_TO_RDWR_BUF,
+	},
+};
+
+static const struct bpf_reg_types int_ptr_types = {
+	.types = {
+		PTR_TO_STACK,
+		PTR_TO_PACKET,
+		PTR_TO_PACKET_META,
+		PTR_TO_MAP_VALUE,
+	},
+};
+
+static const struct bpf_reg_types fullsock_types = { .types = { PTR_TO_SOCKET } };
+static const struct bpf_reg_types scalar_types = { .types = { SCALAR_VALUE } };
+static const struct bpf_reg_types context_types = { .types = { PTR_TO_CTX } };
+static const struct bpf_reg_types alloc_mem_types = { .types = { PTR_TO_MEM } };
+static const struct bpf_reg_types const_map_ptr_types = { .types = { CONST_PTR_TO_MAP } };
+static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } };
+static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } };
+static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_PERCPU_BTF_ID } };
+
+static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = {
+	[ARG_PTR_TO_MAP_KEY]		= &map_key_value_types,
+	[ARG_PTR_TO_MAP_VALUE]		= &map_key_value_types,
+	[ARG_PTR_TO_UNINIT_MAP_VALUE]	= &map_key_value_types,
+	[ARG_PTR_TO_MAP_VALUE_OR_NULL]	= &map_key_value_types,
+	[ARG_CONST_SIZE]		= &scalar_types,
+	[ARG_CONST_SIZE_OR_ZERO]	= &scalar_types,
+	[ARG_CONST_ALLOC_SIZE_OR_ZERO]	= &scalar_types,
+	[ARG_CONST_MAP_PTR]		= &const_map_ptr_types,
+	[ARG_PTR_TO_CTX]		= &context_types,
+	[ARG_PTR_TO_CTX_OR_NULL]	= &context_types,
+	[ARG_PTR_TO_SOCK_COMMON]	= &sock_types,
+#ifdef CONFIG_NET
+	[ARG_PTR_TO_BTF_ID_SOCK_COMMON]	= &btf_id_sock_common_types,
+#endif
+	[ARG_PTR_TO_SOCKET]		= &fullsock_types,
+	[ARG_PTR_TO_SOCKET_OR_NULL]	= &fullsock_types,
+	[ARG_PTR_TO_BTF_ID]		= &btf_ptr_types,
+	[ARG_PTR_TO_SPIN_LOCK]		= &spin_lock_types,
+	[ARG_PTR_TO_MEM]		= &mem_types,
+	[ARG_PTR_TO_MEM_OR_NULL]	= &mem_types,
+	[ARG_PTR_TO_UNINIT_MEM]		= &mem_types,
+	[ARG_PTR_TO_ALLOC_MEM]		= &alloc_mem_types,
+	[ARG_PTR_TO_ALLOC_MEM_OR_NULL]	= &alloc_mem_types,
+	[ARG_PTR_TO_INT]		= &int_ptr_types,
+	[ARG_PTR_TO_LONG]		= &int_ptr_types,
+	[ARG_PTR_TO_PERCPU_BTF_ID]	= &percpu_btf_ptr_types,
+};
+
+static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
 			  enum bpf_arg_type arg_type,
-			  struct bpf_call_arg_meta *meta)
+			  const u32 *arg_btf_id)
 {
 	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
-	enum bpf_reg_type expected_type, type = reg->type;
+	enum bpf_reg_type expected, type = reg->type;
+	const struct bpf_reg_types *compatible;
+	int i, j;
+
+	compatible = compatible_reg_types[arg_type];
+	if (!compatible) {
+		verbose(env, "verifier internal error: unsupported arg type %d\n", arg_type);
+		return -EFAULT;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(compatible->types); i++) {
+		expected = compatible->types[i];
+		if (expected == NOT_INIT)
+			break;
+
+		if (type == expected)
+			goto found;
+	}
+
+	verbose(env, "R%d type=%s expected=", regno, reg_type_str[type]);
+	for (j = 0; j + 1 < i; j++)
+		verbose(env, "%s, ", reg_type_str[compatible->types[j]]);
+	verbose(env, "%s\n", reg_type_str[compatible->types[j]]);
+	return -EACCES;
+
+found:
+	if (type == PTR_TO_BTF_ID) {
+		if (!arg_btf_id) {
+			if (!compatible->btf_id) {
+				verbose(env, "verifier internal error: missing arg compatible BTF ID\n");
+				return -EFAULT;
+			}
+			arg_btf_id = compatible->btf_id;
+		}
+
+		if (!btf_struct_ids_match(&env->log, reg->off, reg->btf_id,
+					  *arg_btf_id)) {
+			verbose(env, "R%d is of type %s but %s is expected\n",
+				regno, kernel_type_name(reg->btf_id),
+				kernel_type_name(*arg_btf_id));
+			return -EACCES;
+		}
+
+		if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+			verbose(env, "R%d is a pointer to in-kernel struct with non-zero offset\n",
+				regno);
+			return -EACCES;
+		}
+	}
+
+	return 0;
+}
+
+static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
+			  struct bpf_call_arg_meta *meta,
+			  const struct bpf_func_proto *fn)
+{
+	u32 regno = BPF_REG_1 + arg;
+	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	enum bpf_arg_type arg_type = fn->arg_type[arg];
+	enum bpf_reg_type type = reg->type;
 	int err = 0;
 
 	if (arg_type == ARG_DONTCARE)
@@ -3320,86 +4494,39 @@
 		return -EACCES;
 	}
 
-	if (arg_type == ARG_PTR_TO_MAP_KEY ||
-	    arg_type == ARG_PTR_TO_MAP_VALUE ||
+	if (arg_type == ARG_PTR_TO_MAP_VALUE ||
 	    arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE ||
 	    arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL) {
-		expected_type = PTR_TO_STACK;
-		if (register_is_null(reg) &&
-		    arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL)
-			/* final test in check_stack_boundary() */;
-		else if (!type_is_pkt_pointer(type) &&
-			 type != PTR_TO_MAP_VALUE &&
-			 type != expected_type)
-			goto err_type;
-	} else if (arg_type == ARG_CONST_SIZE ||
-		   arg_type == ARG_CONST_SIZE_OR_ZERO) {
-		expected_type = SCALAR_VALUE;
-		if (type != expected_type)
-			goto err_type;
-	} else if (arg_type == ARG_CONST_MAP_PTR) {
-		expected_type = CONST_PTR_TO_MAP;
-		if (type != expected_type)
-			goto err_type;
-	} else if (arg_type == ARG_PTR_TO_CTX) {
-		expected_type = PTR_TO_CTX;
-		if (type != expected_type)
-			goto err_type;
+		err = resolve_map_arg_type(env, meta, &arg_type);
+		if (err)
+			return err;
+	}
+
+	if (register_is_null(reg) && arg_type_may_be_null(arg_type))
+		/* A NULL register has a SCALAR_VALUE type, so skip
+		 * type checking.
+		 */
+		goto skip_type_check;
+
+	err = check_reg_type(env, regno, arg_type, fn->arg_btf_id[arg]);
+	if (err)
+		return err;
+
+	if (type == PTR_TO_CTX) {
 		err = check_ctx_reg(env, reg, regno);
 		if (err < 0)
 			return err;
-	} else if (arg_type == ARG_PTR_TO_SOCK_COMMON) {
-		expected_type = PTR_TO_SOCK_COMMON;
-		/* Any sk pointer can be ARG_PTR_TO_SOCK_COMMON */
-		if (!type_is_sk_pointer(type))
-			goto err_type;
-		if (reg->ref_obj_id) {
-			if (meta->ref_obj_id) {
-				verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n",
-					regno, reg->ref_obj_id,
-					meta->ref_obj_id);
-				return -EFAULT;
-			}
-			meta->ref_obj_id = reg->ref_obj_id;
-		}
-	} else if (arg_type == ARG_PTR_TO_SOCKET) {
-		expected_type = PTR_TO_SOCKET;
-		if (type != expected_type)
-			goto err_type;
-	} else if (arg_type == ARG_PTR_TO_SPIN_LOCK) {
-		if (meta->func_id == BPF_FUNC_spin_lock) {
-			if (process_spin_lock(env, regno, true))
-				return -EACCES;
-		} else if (meta->func_id == BPF_FUNC_spin_unlock) {
-			if (process_spin_lock(env, regno, false))
-				return -EACCES;
-		} else {
-			verbose(env, "verifier internal error\n");
+	}
+
+skip_type_check:
+	if (reg->ref_obj_id) {
+		if (meta->ref_obj_id) {
+			verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n",
+				regno, reg->ref_obj_id,
+				meta->ref_obj_id);
 			return -EFAULT;
 		}
-	} else if (arg_type_is_mem_ptr(arg_type)) {
-		expected_type = PTR_TO_STACK;
-		/* One exception here. In case function allows for NULL to be
-		 * passed in as argument, it's a SCALAR_VALUE type. Final test
-		 * happens during stack boundary checking.
-		 */
-		if (register_is_null(reg) &&
-		    arg_type == ARG_PTR_TO_MEM_OR_NULL)
-			/* final test in check_stack_boundary() */;
-		else if (!type_is_pkt_pointer(type) &&
-			 type != PTR_TO_MAP_VALUE &&
-			 type != expected_type)
-			goto err_type;
-		meta->raw_mode = arg_type == ARG_PTR_TO_UNINIT_MEM;
-	} else if (arg_type_is_int_ptr(arg_type)) {
-		expected_type = PTR_TO_STACK;
-		if (!type_is_pkt_pointer(type) &&
-		    type != PTR_TO_MAP_VALUE &&
-		    type != expected_type)
-			goto err_type;
-	} else {
-		verbose(env, "unsupported arg_type %d\n", arg_type);
-		return -EFAULT;
+		meta->ref_obj_id = reg->ref_obj_id;
 	}
 
 	if (arg_type == ARG_CONST_MAP_PTR) {
@@ -3438,11 +4565,38 @@
 		err = check_helper_mem_access(env, regno,
 					      meta->map_ptr->value_size, false,
 					      meta);
+	} else if (arg_type == ARG_PTR_TO_PERCPU_BTF_ID) {
+		if (!reg->btf_id) {
+			verbose(env, "Helper has invalid btf_id in R%d\n", regno);
+			return -EACCES;
+		}
+		meta->ret_btf_id = reg->btf_id;
+	} else if (arg_type == ARG_PTR_TO_SPIN_LOCK) {
+		if (meta->func_id == BPF_FUNC_spin_lock) {
+			if (process_spin_lock(env, regno, true))
+				return -EACCES;
+		} else if (meta->func_id == BPF_FUNC_spin_unlock) {
+			if (process_spin_lock(env, regno, false))
+				return -EACCES;
+		} else {
+			verbose(env, "verifier internal error\n");
+			return -EFAULT;
+		}
+	} else if (arg_type_is_mem_ptr(arg_type)) {
+		/* The access to this pointer is only checked when we hit the
+		 * next is_mem_size argument below.
+		 */
+		meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MEM);
 	} else if (arg_type_is_mem_size(arg_type)) {
 		bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO);
 
-		/* remember the mem_size which may be used later
-		 * to refine return values.
+		/* This is used to refine r0 return value bounds for helpers
+		 * that enforce this value as an upper bound on return values.
+		 * See do_refine_retval_range() for helpers that can refine
+		 * the return value. C type of helper is u32 so we pull register
+		 * bound from umax_value however, if negative verifier errors
+		 * out. Only upper bounds can be learned because retval is an
+		 * int type and negative retvals are allowed.
 		 */
 		meta->msize_max_value = reg->umax_value;
 
@@ -3481,6 +4635,13 @@
 					      zero_size_allowed, meta);
 		if (!err)
 			err = mark_chain_precision(env, regno);
+	} else if (arg_type_is_alloc_size(arg_type)) {
+		if (!tnum_is_const(reg->var_off)) {
+			verbose(env, "R%d unbounded size, use 'var &= const' or 'if (var < const)'\n",
+				regno);
+			return -EACCES;
+		}
+		meta->mem_size = reg->var_off.value;
 	} else if (arg_type_is_int_ptr(arg_type)) {
 		int size = int_ptr_type_to_size(arg_type);
 
@@ -3491,10 +4652,43 @@
 	}
 
 	return err;
-err_type:
-	verbose(env, "R%d type=%s expected=%s\n", regno,
-		reg_type_str[type], reg_type_str[expected_type]);
-	return -EACCES;
+}
+
+static bool may_update_sockmap(struct bpf_verifier_env *env, int func_id)
+{
+	enum bpf_attach_type eatype = env->prog->expected_attach_type;
+	enum bpf_prog_type type = resolve_prog_type(env->prog);
+
+	if (func_id != BPF_FUNC_map_update_elem)
+		return false;
+
+	/* It's not possible to get access to a locked struct sock in these
+	 * contexts, so updating is safe.
+	 */
+	switch (type) {
+	case BPF_PROG_TYPE_TRACING:
+		if (eatype == BPF_TRACE_ITER)
+			return true;
+		break;
+	case BPF_PROG_TYPE_SOCKET_FILTER:
+	case BPF_PROG_TYPE_SCHED_CLS:
+	case BPF_PROG_TYPE_SCHED_ACT:
+	case BPF_PROG_TYPE_XDP:
+	case BPF_PROG_TYPE_SK_REUSEPORT:
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		return true;
+	default:
+		break;
+	}
+
+	verbose(env, "cannot update sockmap in this context\n");
+	return false;
+}
+
+static bool allow_tail_call_in_subprogs(struct bpf_verifier_env *env)
+{
+	return env->prog->jit_requested && IS_ENABLED(CONFIG_X86_64);
 }
 
 static int check_map_func_compatibility(struct bpf_verifier_env *env,
@@ -3512,7 +4706,15 @@
 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
 		if (func_id != BPF_FUNC_perf_event_read &&
 		    func_id != BPF_FUNC_perf_event_output &&
-		    func_id != BPF_FUNC_perf_event_read_value)
+		    func_id != BPF_FUNC_skb_output &&
+		    func_id != BPF_FUNC_perf_event_read_value &&
+		    func_id != BPF_FUNC_xdp_output)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_RINGBUF:
+		if (func_id != BPF_FUNC_ringbuf_output &&
+		    func_id != BPF_FUNC_ringbuf_reserve &&
+		    func_id != BPF_FUNC_ringbuf_query)
 			goto error;
 		break;
 	case BPF_MAP_TYPE_STACK_TRACE:
@@ -3556,14 +4758,20 @@
 		if (func_id != BPF_FUNC_sk_redirect_map &&
 		    func_id != BPF_FUNC_sock_map_update &&
 		    func_id != BPF_FUNC_map_delete_elem &&
-		    func_id != BPF_FUNC_msg_redirect_map)
+		    func_id != BPF_FUNC_msg_redirect_map &&
+		    func_id != BPF_FUNC_sk_select_reuseport &&
+		    func_id != BPF_FUNC_map_lookup_elem &&
+		    !may_update_sockmap(env, func_id))
 			goto error;
 		break;
 	case BPF_MAP_TYPE_SOCKHASH:
 		if (func_id != BPF_FUNC_sk_redirect_hash &&
 		    func_id != BPF_FUNC_sock_hash_update &&
 		    func_id != BPF_FUNC_map_delete_elem &&
-		    func_id != BPF_FUNC_msg_redirect_hash)
+		    func_id != BPF_FUNC_msg_redirect_hash &&
+		    func_id != BPF_FUNC_sk_select_reuseport &&
+		    func_id != BPF_FUNC_map_lookup_elem &&
+		    !may_update_sockmap(env, func_id))
 			goto error;
 		break;
 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
@@ -3582,6 +4790,11 @@
 		    func_id != BPF_FUNC_sk_storage_delete)
 			goto error;
 		break;
+	case BPF_MAP_TYPE_INODE_STORAGE:
+		if (func_id != BPF_FUNC_inode_storage_get &&
+		    func_id != BPF_FUNC_inode_storage_delete)
+			goto error;
+		break;
 	default:
 		break;
 	}
@@ -3591,17 +4804,25 @@
 	case BPF_FUNC_tail_call:
 		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
 			goto error;
-		if (env->subprog_cnt > 1) {
-			verbose(env, "tail_calls are not allowed in programs with bpf-to-bpf calls\n");
+		if (env->subprog_cnt > 1 && !allow_tail_call_in_subprogs(env)) {
+			verbose(env, "tail_calls are not allowed in non-JITed programs with bpf-to-bpf calls\n");
 			return -EINVAL;
 		}
 		break;
 	case BPF_FUNC_perf_event_read:
 	case BPF_FUNC_perf_event_output:
 	case BPF_FUNC_perf_event_read_value:
+	case BPF_FUNC_skb_output:
+	case BPF_FUNC_xdp_output:
 		if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
 			goto error;
 		break;
+	case BPF_FUNC_ringbuf_output:
+	case BPF_FUNC_ringbuf_reserve:
+	case BPF_FUNC_ringbuf_query:
+		if (map->map_type != BPF_MAP_TYPE_RINGBUF)
+			goto error;
+		break;
 	case BPF_FUNC_get_stackid:
 		if (map->map_type != BPF_MAP_TYPE_STACK_TRACE)
 			goto error;
@@ -3636,7 +4857,9 @@
 			goto error;
 		break;
 	case BPF_FUNC_sk_select_reuseport:
-		if (map->map_type != BPF_MAP_TYPE_REUSEPORT_SOCKARRAY)
+		if (map->map_type != BPF_MAP_TYPE_REUSEPORT_SOCKARRAY &&
+		    map->map_type != BPF_MAP_TYPE_SOCKMAP &&
+		    map->map_type != BPF_MAP_TYPE_SOCKHASH)
 			goto error;
 		break;
 	case BPF_FUNC_map_peek_elem:
@@ -3651,6 +4874,11 @@
 		if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
 			goto error;
 		break;
+	case BPF_FUNC_inode_storage_get:
+	case BPF_FUNC_inode_storage_delete:
+		if (map->map_type != BPF_MAP_TYPE_INODE_STORAGE)
+			goto error;
+		break;
 	default:
 		break;
 	}
@@ -3729,7 +4957,7 @@
 	/* A reference acquiring function cannot acquire
 	 * another refcounted ptr.
 	 */
-	if (is_acquire_function(func_id) && count)
+	if (may_be_acquire_function(func_id) && count)
 		return false;
 
 	/* We only support one arg being unreferenced at the moment,
@@ -3738,10 +4966,26 @@
 	return count <= 1;
 }
 
+static bool check_btf_id_ok(const struct bpf_func_proto *fn)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(fn->arg_type); i++) {
+		if (fn->arg_type[i] == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i])
+			return false;
+
+		if (fn->arg_type[i] != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i])
+			return false;
+	}
+
+	return true;
+}
+
 static int check_func_proto(const struct bpf_func_proto *fn, int func_id)
 {
 	return check_raw_mode_ok(fn) &&
 	       check_arg_pair_ok(fn) &&
+	       check_btf_id_ok(fn) &&
 	       check_refcount_ok(fn, func_id) ? 0 : -EINVAL;
 }
 
@@ -3814,12 +5058,26 @@
 	return 0;
 }
 
+static void clear_caller_saved_regs(struct bpf_verifier_env *env,
+				    struct bpf_reg_state *regs)
+{
+	int i;
+
+	/* after the call registers r0 - r5 were scratched */
+	for (i = 0; i < CALLER_SAVED_REGS; i++) {
+		mark_reg_not_init(env, regs, caller_saved[i]);
+		check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK);
+	}
+}
+
 static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 			   int *insn_idx)
 {
 	struct bpf_verifier_state *state = env->cur_state;
+	struct bpf_func_info_aux *func_info_aux;
 	struct bpf_func_state *caller, *callee;
 	int i, err, subprog, target_insn;
+	bool is_global = false;
 
 	if (state->curframe + 1 >= MAX_CALL_FRAMES) {
 		verbose(env, "the call stack of %d frames is too deep\n",
@@ -3842,6 +5100,33 @@
 		return -EFAULT;
 	}
 
+	func_info_aux = env->prog->aux->func_info_aux;
+	if (func_info_aux)
+		is_global = func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
+	err = btf_check_func_arg_match(env, subprog, caller->regs);
+	if (err == -EFAULT)
+		return err;
+	if (is_global) {
+		if (err) {
+			verbose(env, "Caller passes invalid args into func#%d\n",
+				subprog);
+			return err;
+		} else {
+			if (env->log.level & BPF_LOG_LEVEL)
+				verbose(env,
+					"Func#%d is global and valid. Skipping.\n",
+					subprog);
+			clear_caller_saved_regs(env, caller->regs);
+
+			/* All global functions return a 64-bit SCALAR_VALUE */
+			mark_reg_unknown(env, caller->regs, BPF_REG_0);
+			caller->regs[BPF_REG_0].subreg_def = DEF_NOT_SUBREG;
+
+			/* continue with next insn after call */
+			return 0;
+		}
+	}
+
 	callee = kzalloc(sizeof(*callee), GFP_KERNEL);
 	if (!callee)
 		return -ENOMEM;
@@ -3868,11 +5153,7 @@
 	for (i = BPF_REG_1; i <= BPF_REG_5; i++)
 		callee->regs[i] = caller->regs[i];
 
-	/* after the call registers r0 - r5 were scratched */
-	for (i = 0; i < CALLER_SAVED_REGS; i++) {
-		mark_reg_not_init(env, caller->regs, caller_saved[i]);
-		check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK);
-	}
+	clear_caller_saved_regs(env, caller->regs);
 
 	/* only increment it after check_reg_arg() finished */
 	state->curframe++;
@@ -3932,44 +5213,26 @@
 	return 0;
 }
 
-static int do_refine_retval_range(struct bpf_verifier_env *env,
-				  struct bpf_reg_state *regs, int ret_type,
-				  int func_id, struct bpf_call_arg_meta *meta)
+static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
+				   int func_id,
+				   struct bpf_call_arg_meta *meta)
 {
 	struct bpf_reg_state *ret_reg = &regs[BPF_REG_0];
-	struct bpf_reg_state tmp_reg = *ret_reg;
-	bool ret;
 
 	if (ret_type != RET_INTEGER ||
 	    (func_id != BPF_FUNC_get_stack &&
-	     func_id != BPF_FUNC_probe_read_str))
-		return 0;
+	     func_id != BPF_FUNC_probe_read_str &&
+	     func_id != BPF_FUNC_probe_read_kernel_str &&
+	     func_id != BPF_FUNC_probe_read_user_str))
+		return;
 
-	/* Error case where ret is in interval [S32MIN, -1]. */
-	ret_reg->smin_value = S32_MIN;
-	ret_reg->smax_value = -1;
-
-	__reg_deduce_bounds(ret_reg);
-	__reg_bound_offset(ret_reg);
-	__update_reg_bounds(ret_reg);
-
-	ret = push_stack(env, env->insn_idx + 1, env->insn_idx, false);
-	if (!ret)
-		return -EFAULT;
-
-	*ret_reg = tmp_reg;
-
-	/* Success case where ret is in range [0, msize_max_value]. */
-	ret_reg->smin_value = 0;
 	ret_reg->smax_value = meta->msize_max_value;
-	ret_reg->umin_value = ret_reg->smin_value;
-	ret_reg->umax_value = ret_reg->smax_value;
-
+	ret_reg->s32_max_value = meta->msize_max_value;
+	ret_reg->smin_value = -MAX_ERRNO;
+	ret_reg->s32_min_value = -MAX_ERRNO;
 	__reg_deduce_bounds(ret_reg);
 	__reg_bound_offset(ret_reg);
 	__update_reg_bounds(ret_reg);
-
-	return 0;
 }
 
 static int
@@ -4006,12 +5269,51 @@
 		return -EACCES;
 	}
 
-	if (!BPF_MAP_PTR(aux->map_state))
+	if (!BPF_MAP_PTR(aux->map_ptr_state))
 		bpf_map_ptr_store(aux, meta->map_ptr,
-				  meta->map_ptr->unpriv_array);
-	else if (BPF_MAP_PTR(aux->map_state) != meta->map_ptr)
+				  !meta->map_ptr->bypass_spec_v1);
+	else if (BPF_MAP_PTR(aux->map_ptr_state) != meta->map_ptr)
 		bpf_map_ptr_store(aux, BPF_MAP_PTR_POISON,
-				  meta->map_ptr->unpriv_array);
+				  !meta->map_ptr->bypass_spec_v1);
+	return 0;
+}
+
+static int
+record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
+		int func_id, int insn_idx)
+{
+	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
+	struct bpf_reg_state *regs = cur_regs(env), *reg;
+	struct bpf_map *map = meta->map_ptr;
+	struct tnum range;
+	u64 val;
+	int err;
+
+	if (func_id != BPF_FUNC_tail_call)
+		return 0;
+	if (!map || map->map_type != BPF_MAP_TYPE_PROG_ARRAY) {
+		verbose(env, "kernel subsystem misconfigured verifier\n");
+		return -EINVAL;
+	}
+
+	range = tnum_range(0, map->max_entries - 1);
+	reg = &regs[BPF_REG_3];
+
+	if (!register_is_const(reg) || !tnum_in(range, reg->var_off)) {
+		bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
+		return 0;
+	}
+
+	err = mark_chain_precision(env, BPF_REG_3);
+	if (err)
+		return err;
+
+	val = reg->var_off.value;
+	if (bpf_map_key_unseen(aux))
+		bpf_map_key_store(aux, val);
+	else if (!bpf_map_key_poisoned(aux) &&
+		  bpf_map_key_immediate(aux) != val)
+		bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
 	return 0;
 }
 
@@ -4056,6 +5358,11 @@
 		return -EINVAL;
 	}
 
+	if (fn->allowed && !fn->allowed(env->prog)) {
+		verbose(env, "helper call is not allowed in probe\n");
+		return -EINVAL;
+	}
+
 	/* With LD_ABS/IND some JITs save/restore skb from r1. */
 	changes_data = bpf_helper_changes_pkt_data(fn->func);
 	if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) {
@@ -4076,23 +5383,17 @@
 
 	meta.func_id = func_id;
 	/* check args */
-	err = check_func_arg(env, BPF_REG_1, fn->arg1_type, &meta);
-	if (err)
-		return err;
-	err = check_func_arg(env, BPF_REG_2, fn->arg2_type, &meta);
-	if (err)
-		return err;
-	err = check_func_arg(env, BPF_REG_3, fn->arg3_type, &meta);
-	if (err)
-		return err;
-	err = check_func_arg(env, BPF_REG_4, fn->arg4_type, &meta);
-	if (err)
-		return err;
-	err = check_func_arg(env, BPF_REG_5, fn->arg5_type, &meta);
+	for (i = 0; i < 5; i++) {
+		err = check_func_arg(env, i, &meta, fn);
+		if (err)
+			return err;
+	}
+
+	err = record_func_map(env, &meta, func_id, insn_idx);
 	if (err)
 		return err;
 
-	err = record_func_map(env, &meta, func_id, insn_idx);
+	err = record_func_key(env, &meta, func_id, insn_idx);
 	if (err)
 		return err;
 
@@ -4167,30 +5468,74 @@
 				regs[BPF_REG_0].id = ++env->id_gen;
 		} else {
 			regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
-			regs[BPF_REG_0].id = ++env->id_gen;
 		}
 	} else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
-		regs[BPF_REG_0].id = ++env->id_gen;
 	} else if (fn->ret_type == RET_PTR_TO_SOCK_COMMON_OR_NULL) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON_OR_NULL;
-		regs[BPF_REG_0].id = ++env->id_gen;
 	} else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
-		regs[BPF_REG_0].id = ++env->id_gen;
+	} else if (fn->ret_type == RET_PTR_TO_ALLOC_MEM_OR_NULL) {
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL;
+		regs[BPF_REG_0].mem_size = meta.mem_size;
+	} else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL ||
+		   fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID) {
+		const struct btf_type *t;
+
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		t = btf_type_skip_modifiers(btf_vmlinux, meta.ret_btf_id, NULL);
+		if (!btf_type_is_struct(t)) {
+			u32 tsize;
+			const struct btf_type *ret;
+			const char *tname;
+
+			/* resolve the type size of ksym. */
+			ret = btf_resolve_size(btf_vmlinux, t, &tsize);
+			if (IS_ERR(ret)) {
+				tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+				verbose(env, "unable to resolve the size of type '%s': %ld\n",
+					tname, PTR_ERR(ret));
+				return -EINVAL;
+			}
+			regs[BPF_REG_0].type =
+				fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+				PTR_TO_MEM : PTR_TO_MEM_OR_NULL;
+			regs[BPF_REG_0].mem_size = tsize;
+		} else {
+			regs[BPF_REG_0].type =
+				fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+				PTR_TO_BTF_ID : PTR_TO_BTF_ID_OR_NULL;
+			regs[BPF_REG_0].btf_id = meta.ret_btf_id;
+		}
+	} else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL) {
+		int ret_btf_id;
+
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_BTF_ID_OR_NULL;
+		ret_btf_id = *fn->ret_btf_id;
+		if (ret_btf_id == 0) {
+			verbose(env, "invalid return type %d of func %s#%d\n",
+				fn->ret_type, func_id_name(func_id), func_id);
+			return -EINVAL;
+		}
+		regs[BPF_REG_0].btf_id = ret_btf_id;
 	} else {
 		verbose(env, "unknown return type %d of func %s#%d\n",
 			fn->ret_type, func_id_name(func_id), func_id);
 		return -EINVAL;
 	}
 
+	if (reg_type_may_be_null(regs[BPF_REG_0].type))
+		regs[BPF_REG_0].id = ++env->id_gen;
+
 	if (is_ptr_cast_function(func_id)) {
 		/* For release_reference() */
 		regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id;
-	} else if (is_acquire_function(func_id)) {
+	} else if (is_acquire_function(func_id, meta.map_ptr)) {
 		int id = acquire_reference_state(env, insn_idx);
 
 		if (id < 0)
@@ -4201,15 +5546,15 @@
 		regs[BPF_REG_0].ref_obj_id = id;
 	}
 
-	err = do_refine_retval_range(env, regs, fn->ret_type, func_id, &meta);
-	if (err)
-		return err;
+	do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
 
 	err = check_map_func_compatibility(env, meta.map_ptr, func_id);
 	if (err)
 		return err;
 
-	if (func_id == BPF_FUNC_get_stack && !env->prog->has_callchain_buf) {
+	if ((func_id == BPF_FUNC_get_stack ||
+	     func_id == BPF_FUNC_get_task_stack) &&
+	    !env->prog->has_callchain_buf) {
 		const char *err_str;
 
 #ifdef CONFIG_PERF_EVENTS
@@ -4227,6 +5572,9 @@
 		env->prog->has_callchain_buf = true;
 	}
 
+	if (func_id == BPF_FUNC_get_stackid || func_id == BPF_FUNC_get_stack)
+		env->prog->call_get_stack = true;
+
 	if (changes_data)
 		clear_all_pkt_pointers(env);
 	return 0;
@@ -4242,6 +5590,16 @@
 	return res < a;
 }
 
+static bool signed_add32_overflows(s32 a, s32 b)
+{
+	/* Do the add in u32, where overflow is well-defined */
+	s32 res = (s32)((u32)a + (u32)b);
+
+	if (b < 0)
+		return res > a;
+	return res < a;
+}
+
 static bool signed_sub_overflows(s64 a, s64 b)
 {
 	/* Do the sub in u64, where overflow is well-defined */
@@ -4252,6 +5610,16 @@
 	return res > a;
 }
 
+static bool signed_sub32_overflows(s32 a, s32 b)
+{
+	/* Do the sub in u32, where overflow is well-defined */
+	s32 res = (s32)((u32)a - (u32)b);
+
+	if (b < 0)
+		return res < a;
+	return res > a;
+}
+
 static bool check_reg_sane_offset(struct bpf_verifier_env *env,
 				  const struct bpf_reg_state *reg,
 				  enum bpf_reg_type type)
@@ -4334,7 +5702,7 @@
 static bool can_skip_alu_sanitation(const struct bpf_verifier_env *env,
 				    const struct bpf_insn *insn)
 {
-	return env->allow_ptr_leaks || BPF_SRC(insn->code) == BPF_K;
+	return env->bypass_spec_v1 || BPF_SRC(insn->code) == BPF_K;
 }
 
 static int update_alu_sanitation_state(struct bpf_insn_aux_data *aux,
@@ -4502,7 +5870,7 @@
 	 * rewrite/sanitize them.
 	 */
 	if (!vstate->speculative)
-		env->insn_aux_data[env->insn_idx].seen = true;
+		env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
 }
 
 static int sanitize_err(struct bpf_verifier_env *env,
@@ -4544,6 +5912,40 @@
 	return -EACCES;
 }
 
+/* check that stack access falls within stack limits and that 'reg' doesn't
+ * have a variable offset.
+ *
+ * Variable offset is prohibited for unprivileged mode for simplicity since it
+ * requires corresponding support in Spectre masking for stack ALU.  See also
+ * retrieve_ptr_limit().
+ *
+ *
+ * 'off' includes 'reg->off'.
+ */
+static int check_stack_access_for_ptr_arithmetic(
+				struct bpf_verifier_env *env,
+				int regno,
+				const struct bpf_reg_state *reg,
+				int off)
+{
+	if (!tnum_is_const(reg->var_off)) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env, "R%d variable stack access prohibited for !root, var_off=%s off=%d\n",
+			regno, tn_buf, off);
+		return -EACCES;
+	}
+
+	if (off >= 0 || off < -MAX_BPF_STACK) {
+		verbose(env, "R%d stack pointer arithmetic goes out of range, "
+			"prohibited for !root; off=%d\n", regno, off);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
 static int sanitize_check_bounds(struct bpf_verifier_env *env,
 				 const struct bpf_insn *insn,
 				 const struct bpf_reg_state *dst_reg)
@@ -4553,17 +5955,14 @@
 	/* For unprivileged we require that resulting offset must be in bounds
 	 * in order to be able to sanitize access later on.
 	 */
-	if (env->allow_ptr_leaks)
+	if (env->bypass_spec_v1)
 		return 0;
 
 	switch (dst_reg->type) {
 	case PTR_TO_STACK:
-		if (check_stack_access(env, dst_reg, dst_reg->off +
-				       dst_reg->var_off.value, 1)) {
-			verbose(env, "R%d stack pointer arithmetic goes out of range, "
-				"prohibited for !root\n", dst);
+		if (check_stack_access_for_ptr_arithmetic(env, dst, dst_reg,
+					dst_reg->off + dst_reg->var_off.value))
 			return -EACCES;
-		}
 		break;
 	case PTR_TO_MAP_VALUE:
 		if (check_map_access(env, dst, dst_reg->off, 1, false)) {
@@ -4615,6 +6014,11 @@
 
 	if (BPF_CLASS(insn->code) != BPF_ALU64) {
 		/* 32-bit ALU ops on pointers produce (meaningless) scalars */
+		if (opcode == BPF_SUB && env->allow_ptr_leaks) {
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
+
 		verbose(env,
 			"R%d 32-bit pointer arithmetic prohibited\n",
 			dst);
@@ -4630,19 +6034,19 @@
 		/* smin_val represents the known value */
 		if (known && smin_val == 0 && opcode == BPF_ADD)
 			break;
-		/* fall-through */
+		fallthrough;
 	case PTR_TO_PACKET_END:
 	case PTR_TO_SOCKET:
-	case PTR_TO_SOCKET_OR_NULL:
 	case PTR_TO_SOCK_COMMON:
-	case PTR_TO_SOCK_COMMON_OR_NULL:
 	case PTR_TO_TCP_SOCK:
-	case PTR_TO_TCP_SOCK_OR_NULL:
 	case PTR_TO_XDP_SOCK:
+reject:
 		verbose(env, "R%d pointer arithmetic on %s prohibited\n",
 			dst, reg_type_str[ptr_reg->type]);
 		return -EACCES;
 	default:
+		if (reg_type_may_be_null(ptr_reg->type))
+			goto reject;
 		break;
 	}
 
@@ -4656,6 +6060,9 @@
 	    !check_reg_sane_offset(env, ptr_reg, ptr_reg->type))
 		return -EINVAL;
 
+	/* pointer types do not carry 32-bit bounds at the moment. */
+	__mark_reg32_unbounded(dst_reg);
+
 	if (sanitize_needed(opcode)) {
 		ret = sanitize_ptr_alu(env, insn, ptr_reg, off_reg, dst_reg,
 				       &info, false);
@@ -4807,6 +6214,573 @@
 	return 0;
 }
 
+static void scalar32_min_max_add(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	s32 smax_val = src_reg->s32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (signed_add32_overflows(dst_reg->s32_min_value, smin_val) ||
+	    signed_add32_overflows(dst_reg->s32_max_value, smax_val)) {
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value += smin_val;
+		dst_reg->s32_max_value += smax_val;
+	}
+	if (dst_reg->u32_min_value + umin_val < umin_val ||
+	    dst_reg->u32_max_value + umax_val < umax_val) {
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		dst_reg->u32_min_value += umin_val;
+		dst_reg->u32_max_value += umax_val;
+	}
+}
+
+static void scalar_min_max_add(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	s64 smin_val = src_reg->smin_value;
+	s64 smax_val = src_reg->smax_value;
+	u64 umin_val = src_reg->umin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
+	    signed_add_overflows(dst_reg->smax_value, smax_val)) {
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		dst_reg->smin_value += smin_val;
+		dst_reg->smax_value += smax_val;
+	}
+	if (dst_reg->umin_value + umin_val < umin_val ||
+	    dst_reg->umax_value + umax_val < umax_val) {
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+	} else {
+		dst_reg->umin_value += umin_val;
+		dst_reg->umax_value += umax_val;
+	}
+}
+
+static void scalar32_min_max_sub(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	s32 smax_val = src_reg->s32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (signed_sub32_overflows(dst_reg->s32_min_value, smax_val) ||
+	    signed_sub32_overflows(dst_reg->s32_max_value, smin_val)) {
+		/* Overflow possible, we know nothing */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value -= smax_val;
+		dst_reg->s32_max_value -= smin_val;
+	}
+	if (dst_reg->u32_min_value < umax_val) {
+		/* Overflow possible, we know nothing */
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		/* Cannot overflow (as long as bounds are consistent) */
+		dst_reg->u32_min_value -= umax_val;
+		dst_reg->u32_max_value -= umin_val;
+	}
+}
+
+static void scalar_min_max_sub(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	s64 smin_val = src_reg->smin_value;
+	s64 smax_val = src_reg->smax_value;
+	u64 umin_val = src_reg->umin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
+	    signed_sub_overflows(dst_reg->smax_value, smin_val)) {
+		/* Overflow possible, we know nothing */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		dst_reg->smin_value -= smax_val;
+		dst_reg->smax_value -= smin_val;
+	}
+	if (dst_reg->umin_value < umax_val) {
+		/* Overflow possible, we know nothing */
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+	} else {
+		/* Cannot overflow (as long as bounds are consistent) */
+		dst_reg->umin_value -= umax_val;
+		dst_reg->umax_value -= umin_val;
+	}
+}
+
+static void scalar32_min_max_mul(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (smin_val < 0 || dst_reg->s32_min_value < 0) {
+		/* Ain't nobody got time to multiply that sign */
+		__mark_reg32_unbounded(dst_reg);
+		return;
+	}
+	/* Both values are positive, so we can work with unsigned and
+	 * copy the result to signed (unless it exceeds S32_MAX).
+	 */
+	if (umax_val > U16_MAX || dst_reg->u32_max_value > U16_MAX) {
+		/* Potential overflow, we know nothing */
+		__mark_reg32_unbounded(dst_reg);
+		return;
+	}
+	dst_reg->u32_min_value *= umin_val;
+	dst_reg->u32_max_value *= umax_val;
+	if (dst_reg->u32_max_value > S32_MAX) {
+		/* Overflow possible, we know nothing */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
+}
+
+static void scalar_min_max_mul(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	s64 smin_val = src_reg->smin_value;
+	u64 umin_val = src_reg->umin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (smin_val < 0 || dst_reg->smin_value < 0) {
+		/* Ain't nobody got time to multiply that sign */
+		__mark_reg64_unbounded(dst_reg);
+		return;
+	}
+	/* Both values are positive, so we can work with unsigned and
+	 * copy the result to signed (unless it exceeds S64_MAX).
+	 */
+	if (umax_val > U32_MAX || dst_reg->umax_value > U32_MAX) {
+		/* Potential overflow, we know nothing */
+		__mark_reg64_unbounded(dst_reg);
+		return;
+	}
+	dst_reg->umin_value *= umin_val;
+	dst_reg->umax_value *= umax_val;
+	if (dst_reg->umax_value > S64_MAX) {
+		/* Overflow possible, we know nothing */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	}
+}
+
+static void scalar32_min_max_and(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (src_known && dst_known) {
+		__mark_reg32_known(dst_reg, var32_off.value);
+		return;
+	}
+
+	/* We get our minimum from the var_off, since that's inherently
+	 * bitwise.  Our maximum is the minimum of the operands' maxima.
+	 */
+	dst_reg->u32_min_value = var32_off.value;
+	dst_reg->u32_max_value = min(dst_reg->u32_max_value, umax_val);
+	if (dst_reg->s32_min_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ANDing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		/* ANDing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
+}
+
+static void scalar_min_max_and(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
+	s64 smin_val = src_reg->smin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (src_known && dst_known) {
+		__mark_reg_known(dst_reg, dst_reg->var_off.value);
+		return;
+	}
+
+	/* We get our minimum from the var_off, since that's inherently
+	 * bitwise.  Our maximum is the minimum of the operands' maxima.
+	 */
+	dst_reg->umin_value = dst_reg->var_off.value;
+	dst_reg->umax_value = min(dst_reg->umax_value, umax_val);
+	if (dst_reg->smin_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ANDing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		/* ANDing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	}
+	/* We may learn something more from the var_off */
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_or(struct bpf_reg_state *dst_reg,
+				struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umin_val = src_reg->u32_min_value;
+
+	if (src_known && dst_known) {
+		__mark_reg32_known(dst_reg, var32_off.value);
+		return;
+	}
+
+	/* We get our maximum from the var_off, and our minimum is the
+	 * maximum of the operands' minima
+	 */
+	dst_reg->u32_min_value = max(dst_reg->u32_min_value, umin_val);
+	dst_reg->u32_max_value = var32_off.value | var32_off.mask;
+	if (dst_reg->s32_min_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ORing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		/* ORing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
+}
+
+static void scalar_min_max_or(struct bpf_reg_state *dst_reg,
+			      struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
+	s64 smin_val = src_reg->smin_value;
+	u64 umin_val = src_reg->umin_value;
+
+	if (src_known && dst_known) {
+		__mark_reg_known(dst_reg, dst_reg->var_off.value);
+		return;
+	}
+
+	/* We get our maximum from the var_off, and our minimum is the
+	 * maximum of the operands' minima
+	 */
+	dst_reg->umin_value = max(dst_reg->umin_value, umin_val);
+	dst_reg->umax_value = dst_reg->var_off.value | dst_reg->var_off.mask;
+	if (dst_reg->smin_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ORing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		/* ORing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	}
+	/* We may learn something more from the var_off */
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_xor(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->s32_min_value;
+
+	if (src_known && dst_known) {
+		__mark_reg32_known(dst_reg, var32_off.value);
+		return;
+	}
+
+	/* We get both minimum and maximum from the var32_off. */
+	dst_reg->u32_min_value = var32_off.value;
+	dst_reg->u32_max_value = var32_off.value | var32_off.mask;
+
+	if (dst_reg->s32_min_value >= 0 && smin_val >= 0) {
+		/* XORing two positive sign numbers gives a positive,
+		 * so safe to cast u32 result into s32.
+		 */
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	} else {
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	}
+}
+
+static void scalar_min_max_xor(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
+	s64 smin_val = src_reg->smin_value;
+
+	if (src_known && dst_known) {
+		/* dst_reg->var_off.value has been updated earlier */
+		__mark_reg_known(dst_reg, dst_reg->var_off.value);
+		return;
+	}
+
+	/* We get both minimum and maximum from the var_off. */
+	dst_reg->umin_value = dst_reg->var_off.value;
+	dst_reg->umax_value = dst_reg->var_off.value | dst_reg->var_off.mask;
+
+	if (dst_reg->smin_value >= 0 && smin_val >= 0) {
+		/* XORing two positive sign numbers gives a positive,
+		 * so safe to cast u64 result into s64.
+		 */
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	} else {
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	}
+
+	__update_reg_bounds(dst_reg);
+}
+
+static void __scalar32_min_max_lsh(struct bpf_reg_state *dst_reg,
+				   u64 umin_val, u64 umax_val)
+{
+	/* We lose all sign bit information (except what we can pick
+	 * up from var_off)
+	 */
+	dst_reg->s32_min_value = S32_MIN;
+	dst_reg->s32_max_value = S32_MAX;
+	/* If we might shift our top bit out, then we know nothing */
+	if (umax_val > 31 || dst_reg->u32_max_value > 1ULL << (31 - umax_val)) {
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		dst_reg->u32_min_value <<= umin_val;
+		dst_reg->u32_max_value <<= umax_val;
+	}
+}
+
+static void scalar32_min_max_lsh(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	u32 umax_val = src_reg->u32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	/* u32 alu operation will zext upper bits */
+	struct tnum subreg = tnum_subreg(dst_reg->var_off);
+
+	__scalar32_min_max_lsh(dst_reg, umin_val, umax_val);
+	dst_reg->var_off = tnum_subreg(tnum_lshift(subreg, umin_val));
+	/* Not required but being careful mark reg64 bounds as unknown so
+	 * that we are forced to pick them up from tnum and zext later and
+	 * if some path skips this step we are still safe.
+	 */
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void __scalar64_min_max_lsh(struct bpf_reg_state *dst_reg,
+				   u64 umin_val, u64 umax_val)
+{
+	/* Special case <<32 because it is a common compiler pattern to sign
+	 * extend subreg by doing <<32 s>>32. In this case if 32bit bounds are
+	 * positive we know this shift will also be positive so we can track
+	 * bounds correctly. Otherwise we lose all sign bit information except
+	 * what we can pick up from var_off. Perhaps we can generalize this
+	 * later to shifts of any length.
+	 */
+	if (umin_val == 32 && umax_val == 32 && dst_reg->s32_max_value >= 0)
+		dst_reg->smax_value = (s64)dst_reg->s32_max_value << 32;
+	else
+		dst_reg->smax_value = S64_MAX;
+
+	if (umin_val == 32 && umax_val == 32 && dst_reg->s32_min_value >= 0)
+		dst_reg->smin_value = (s64)dst_reg->s32_min_value << 32;
+	else
+		dst_reg->smin_value = S64_MIN;
+
+	/* If we might shift our top bit out, then we know nothing */
+	if (dst_reg->umax_value > 1ULL << (63 - umax_val)) {
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+	} else {
+		dst_reg->umin_value <<= umin_val;
+		dst_reg->umax_value <<= umax_val;
+	}
+}
+
+static void scalar_min_max_lsh(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	u64 umax_val = src_reg->umax_value;
+	u64 umin_val = src_reg->umin_value;
+
+	/* scalar64 calc uses 32bit unshifted bounds so must be called first */
+	__scalar64_min_max_lsh(dst_reg, umin_val, umax_val);
+	__scalar32_min_max_lsh(dst_reg, umin_val, umax_val);
+
+	dst_reg->var_off = tnum_lshift(dst_reg->var_off, umin_val);
+	/* We may learn something more from the var_off */
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_rsh(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	struct tnum subreg = tnum_subreg(dst_reg->var_off);
+	u32 umax_val = src_reg->u32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+
+	/* BPF_RSH is an unsigned shift.  If the value in dst_reg might
+	 * be negative, then either:
+	 * 1) src_reg might be zero, so the sign bit of the result is
+	 *    unknown, so we lose our signed bounds
+	 * 2) it's known negative, thus the unsigned bounds capture the
+	 *    signed bounds
+	 * 3) the signed bounds cross zero, so they tell us nothing
+	 *    about the result
+	 * If the value in dst_reg is known nonnegative, then again the
+	 * unsigned bounts capture the signed bounds.
+	 * Thus, in all cases it suffices to blow away our signed bounds
+	 * and rely on inferring new ones from the unsigned bounds and
+	 * var_off of the result.
+	 */
+	dst_reg->s32_min_value = S32_MIN;
+	dst_reg->s32_max_value = S32_MAX;
+
+	dst_reg->var_off = tnum_rshift(subreg, umin_val);
+	dst_reg->u32_min_value >>= umax_val;
+	dst_reg->u32_max_value >>= umin_val;
+
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void scalar_min_max_rsh(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	u64 umax_val = src_reg->umax_value;
+	u64 umin_val = src_reg->umin_value;
+
+	/* BPF_RSH is an unsigned shift.  If the value in dst_reg might
+	 * be negative, then either:
+	 * 1) src_reg might be zero, so the sign bit of the result is
+	 *    unknown, so we lose our signed bounds
+	 * 2) it's known negative, thus the unsigned bounds capture the
+	 *    signed bounds
+	 * 3) the signed bounds cross zero, so they tell us nothing
+	 *    about the result
+	 * If the value in dst_reg is known nonnegative, then again the
+	 * unsigned bounts capture the signed bounds.
+	 * Thus, in all cases it suffices to blow away our signed bounds
+	 * and rely on inferring new ones from the unsigned bounds and
+	 * var_off of the result.
+	 */
+	dst_reg->smin_value = S64_MIN;
+	dst_reg->smax_value = S64_MAX;
+	dst_reg->var_off = tnum_rshift(dst_reg->var_off, umin_val);
+	dst_reg->umin_value >>= umax_val;
+	dst_reg->umax_value >>= umin_val;
+
+	/* Its not easy to operate on alu32 bounds here because it depends
+	 * on bits being shifted in. Take easy way out and mark unbounded
+	 * so we can recalculate later from tnum.
+	 */
+	__mark_reg32_unbounded(dst_reg);
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_arsh(struct bpf_reg_state *dst_reg,
+				  struct bpf_reg_state *src_reg)
+{
+	u64 umin_val = src_reg->u32_min_value;
+
+	/* Upon reaching here, src_known is true and
+	 * umax_val is equal to umin_val.
+	 */
+	dst_reg->s32_min_value = (u32)(((s32)dst_reg->s32_min_value) >> umin_val);
+	dst_reg->s32_max_value = (u32)(((s32)dst_reg->s32_max_value) >> umin_val);
+
+	dst_reg->var_off = tnum_arshift(tnum_subreg(dst_reg->var_off), umin_val, 32);
+
+	/* blow away the dst_reg umin_value/umax_value and rely on
+	 * dst_reg var_off to refine the result.
+	 */
+	dst_reg->u32_min_value = 0;
+	dst_reg->u32_max_value = U32_MAX;
+
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void scalar_min_max_arsh(struct bpf_reg_state *dst_reg,
+				struct bpf_reg_state *src_reg)
+{
+	u64 umin_val = src_reg->umin_value;
+
+	/* Upon reaching here, src_known is true and umax_val is equal
+	 * to umin_val.
+	 */
+	dst_reg->smin_value >>= umin_val;
+	dst_reg->smax_value >>= umin_val;
+
+	dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val, 64);
+
+	/* blow away the dst_reg umin_value/umax_value and rely on
+	 * dst_reg var_off to refine the result.
+	 */
+	dst_reg->umin_value = 0;
+	dst_reg->umax_value = U64_MAX;
+
+	/* Its not easy to operate on alu32 bounds here because it depends
+	 * on bits being shifted in from upper 32-bits. Take easy way out
+	 * and mark unbounded so we can recalculate later from tnum.
+	 */
+	__mark_reg32_unbounded(dst_reg);
+	__update_reg_bounds(dst_reg);
+}
+
 /* WARNING: This function does calculations on 64-bit values, but the actual
  * execution may occur on 32-bit values. Therefore, things like bitshifts
  * need extra checks in the 32-bit case.
@@ -4818,35 +6792,47 @@
 {
 	struct bpf_reg_state *regs = cur_regs(env);
 	u8 opcode = BPF_OP(insn->code);
-	bool src_known, dst_known;
+	bool src_known;
 	s64 smin_val, smax_val;
 	u64 umin_val, umax_val;
+	s32 s32_min_val, s32_max_val;
+	u32 u32_min_val, u32_max_val;
 	u64 insn_bitness = (BPF_CLASS(insn->code) == BPF_ALU64) ? 64 : 32;
+	bool alu32 = (BPF_CLASS(insn->code) != BPF_ALU64);
 	int ret;
 
-	if (insn_bitness == 32) {
-		/* Relevant for 32-bit RSH: Information can propagate towards
-		 * LSB, so it isn't sufficient to only truncate the output to
-		 * 32 bits.
-		 */
-		coerce_reg_to_size(dst_reg, 4);
-		coerce_reg_to_size(&src_reg, 4);
-	}
-
 	smin_val = src_reg.smin_value;
 	smax_val = src_reg.smax_value;
 	umin_val = src_reg.umin_value;
 	umax_val = src_reg.umax_value;
-	src_known = tnum_is_const(src_reg.var_off);
-	dst_known = tnum_is_const(dst_reg->var_off);
 
-	if ((src_known && (smin_val != smax_val || umin_val != umax_val)) ||
-	    smin_val > smax_val || umin_val > umax_val) {
-		/* Taint dst register if offset had invalid bounds derived from
-		 * e.g. dead branches.
-		 */
-		__mark_reg_unknown(env, dst_reg);
-		return 0;
+	s32_min_val = src_reg.s32_min_value;
+	s32_max_val = src_reg.s32_max_value;
+	u32_min_val = src_reg.u32_min_value;
+	u32_max_val = src_reg.u32_max_value;
+
+	if (alu32) {
+		src_known = tnum_subreg_is_const(src_reg.var_off);
+		if ((src_known &&
+		     (s32_min_val != s32_max_val || u32_min_val != u32_max_val)) ||
+		    s32_min_val > s32_max_val || u32_min_val > u32_max_val) {
+			/* Taint dst register if offset had invalid bounds
+			 * derived from e.g. dead branches.
+			 */
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
+	} else {
+		src_known = tnum_is_const(src_reg.var_off);
+		if ((src_known &&
+		     (smin_val != smax_val || umin_val != umax_val)) ||
+		    smin_val > smax_val || umin_val > umax_val) {
+			/* Taint dst register if offset had invalid bounds
+			 * derived from e.g. dead branches.
+			 */
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
 	}
 
 	if (!src_known &&
@@ -4861,132 +6847,50 @@
 			return sanitize_err(env, insn, ret, NULL, NULL);
 	}
 
+	/* Calculate sign/unsigned bounds and tnum for alu32 and alu64 bit ops.
+	 * There are two classes of instructions: The first class we track both
+	 * alu32 and alu64 sign/unsigned bounds independently this provides the
+	 * greatest amount of precision when alu operations are mixed with jmp32
+	 * operations. These operations are BPF_ADD, BPF_SUB, BPF_MUL, BPF_ADD,
+	 * and BPF_OR. This is possible because these ops have fairly easy to
+	 * understand and calculate behavior in both 32-bit and 64-bit alu ops.
+	 * See alu32 verifier tests for examples. The second class of
+	 * operations, BPF_LSH, BPF_RSH, and BPF_ARSH, however are not so easy
+	 * with regards to tracking sign/unsigned bounds because the bits may
+	 * cross subreg boundaries in the alu64 case. When this happens we mark
+	 * the reg unbounded in the subreg bound space and use the resulting
+	 * tnum to calculate an approximation of the sign/unsigned bounds.
+	 */
 	switch (opcode) {
 	case BPF_ADD:
-		if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
-		    signed_add_overflows(dst_reg->smax_value, smax_val)) {
-			dst_reg->smin_value = S64_MIN;
-			dst_reg->smax_value = S64_MAX;
-		} else {
-			dst_reg->smin_value += smin_val;
-			dst_reg->smax_value += smax_val;
-		}
-		if (dst_reg->umin_value + umin_val < umin_val ||
-		    dst_reg->umax_value + umax_val < umax_val) {
-			dst_reg->umin_value = 0;
-			dst_reg->umax_value = U64_MAX;
-		} else {
-			dst_reg->umin_value += umin_val;
-			dst_reg->umax_value += umax_val;
-		}
+		scalar32_min_max_add(dst_reg, &src_reg);
+		scalar_min_max_add(dst_reg, &src_reg);
 		dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off);
 		break;
 	case BPF_SUB:
-		if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
-		    signed_sub_overflows(dst_reg->smax_value, smin_val)) {
-			/* Overflow possible, we know nothing */
-			dst_reg->smin_value = S64_MIN;
-			dst_reg->smax_value = S64_MAX;
-		} else {
-			dst_reg->smin_value -= smax_val;
-			dst_reg->smax_value -= smin_val;
-		}
-		if (dst_reg->umin_value < umax_val) {
-			/* Overflow possible, we know nothing */
-			dst_reg->umin_value = 0;
-			dst_reg->umax_value = U64_MAX;
-		} else {
-			/* Cannot overflow (as long as bounds are consistent) */
-			dst_reg->umin_value -= umax_val;
-			dst_reg->umax_value -= umin_val;
-		}
+		scalar32_min_max_sub(dst_reg, &src_reg);
+		scalar_min_max_sub(dst_reg, &src_reg);
 		dst_reg->var_off = tnum_sub(dst_reg->var_off, src_reg.var_off);
 		break;
 	case BPF_MUL:
 		dst_reg->var_off = tnum_mul(dst_reg->var_off, src_reg.var_off);
-		if (smin_val < 0 || dst_reg->smin_value < 0) {
-			/* Ain't nobody got time to multiply that sign */
-			__mark_reg_unbounded(dst_reg);
-			__update_reg_bounds(dst_reg);
-			break;
-		}
-		/* Both values are positive, so we can work with unsigned and
-		 * copy the result to signed (unless it exceeds S64_MAX).
-		 */
-		if (umax_val > U32_MAX || dst_reg->umax_value > U32_MAX) {
-			/* Potential overflow, we know nothing */
-			__mark_reg_unbounded(dst_reg);
-			/* (except what we can learn from the var_off) */
-			__update_reg_bounds(dst_reg);
-			break;
-		}
-		dst_reg->umin_value *= umin_val;
-		dst_reg->umax_value *= umax_val;
-		if (dst_reg->umax_value > S64_MAX) {
-			/* Overflow possible, we know nothing */
-			dst_reg->smin_value = S64_MIN;
-			dst_reg->smax_value = S64_MAX;
-		} else {
-			dst_reg->smin_value = dst_reg->umin_value;
-			dst_reg->smax_value = dst_reg->umax_value;
-		}
+		scalar32_min_max_mul(dst_reg, &src_reg);
+		scalar_min_max_mul(dst_reg, &src_reg);
 		break;
 	case BPF_AND:
-		if (src_known && dst_known) {
-			__mark_reg_known(dst_reg, dst_reg->var_off.value &
-						  src_reg.var_off.value);
-			break;
-		}
-		/* We get our minimum from the var_off, since that's inherently
-		 * bitwise.  Our maximum is the minimum of the operands' maxima.
-		 */
 		dst_reg->var_off = tnum_and(dst_reg->var_off, src_reg.var_off);
-		dst_reg->umin_value = dst_reg->var_off.value;
-		dst_reg->umax_value = min(dst_reg->umax_value, umax_val);
-		if (dst_reg->smin_value < 0 || smin_val < 0) {
-			/* Lose signed bounds when ANDing negative numbers,
-			 * ain't nobody got time for that.
-			 */
-			dst_reg->smin_value = S64_MIN;
-			dst_reg->smax_value = S64_MAX;
-		} else {
-			/* ANDing two positives gives a positive, so safe to
-			 * cast result into s64.
-			 */
-			dst_reg->smin_value = dst_reg->umin_value;
-			dst_reg->smax_value = dst_reg->umax_value;
-		}
-		/* We may learn something more from the var_off */
-		__update_reg_bounds(dst_reg);
+		scalar32_min_max_and(dst_reg, &src_reg);
+		scalar_min_max_and(dst_reg, &src_reg);
 		break;
 	case BPF_OR:
-		if (src_known && dst_known) {
-			__mark_reg_known(dst_reg, dst_reg->var_off.value |
-						  src_reg.var_off.value);
-			break;
-		}
-		/* We get our maximum from the var_off, and our minimum is the
-		 * maximum of the operands' minima
-		 */
 		dst_reg->var_off = tnum_or(dst_reg->var_off, src_reg.var_off);
-		dst_reg->umin_value = max(dst_reg->umin_value, umin_val);
-		dst_reg->umax_value = dst_reg->var_off.value |
-				      dst_reg->var_off.mask;
-		if (dst_reg->smin_value < 0 || smin_val < 0) {
-			/* Lose signed bounds when ORing negative numbers,
-			 * ain't nobody got time for that.
-			 */
-			dst_reg->smin_value = S64_MIN;
-			dst_reg->smax_value = S64_MAX;
-		} else {
-			/* ORing two positives gives a positive, so safe to
-			 * cast result into s64.
-			 */
-			dst_reg->smin_value = dst_reg->umin_value;
-			dst_reg->smax_value = dst_reg->umax_value;
-		}
-		/* We may learn something more from the var_off */
-		__update_reg_bounds(dst_reg);
+		scalar32_min_max_or(dst_reg, &src_reg);
+		scalar_min_max_or(dst_reg, &src_reg);
+		break;
+	case BPF_XOR:
+		dst_reg->var_off = tnum_xor(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_xor(dst_reg, &src_reg);
+		scalar_min_max_xor(dst_reg, &src_reg);
 		break;
 	case BPF_LSH:
 		if (umax_val >= insn_bitness) {
@@ -4996,22 +6900,10 @@
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
 		}
-		/* We lose all sign bit information (except what we can pick
-		 * up from var_off)
-		 */
-		dst_reg->smin_value = S64_MIN;
-		dst_reg->smax_value = S64_MAX;
-		/* If we might shift our top bit out, then we know nothing */
-		if (dst_reg->umax_value > 1ULL << (63 - umax_val)) {
-			dst_reg->umin_value = 0;
-			dst_reg->umax_value = U64_MAX;
-		} else {
-			dst_reg->umin_value <<= umin_val;
-			dst_reg->umax_value <<= umax_val;
-		}
-		dst_reg->var_off = tnum_lshift(dst_reg->var_off, umin_val);
-		/* We may learn something more from the var_off */
-		__update_reg_bounds(dst_reg);
+		if (alu32)
+			scalar32_min_max_lsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_lsh(dst_reg, &src_reg);
 		break;
 	case BPF_RSH:
 		if (umax_val >= insn_bitness) {
@@ -5021,27 +6913,10 @@
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
 		}
-		/* BPF_RSH is an unsigned shift.  If the value in dst_reg might
-		 * be negative, then either:
-		 * 1) src_reg might be zero, so the sign bit of the result is
-		 *    unknown, so we lose our signed bounds
-		 * 2) it's known negative, thus the unsigned bounds capture the
-		 *    signed bounds
-		 * 3) the signed bounds cross zero, so they tell us nothing
-		 *    about the result
-		 * If the value in dst_reg is known nonnegative, then again the
-		 * unsigned bounts capture the signed bounds.
-		 * Thus, in all cases it suffices to blow away our signed bounds
-		 * and rely on inferring new ones from the unsigned bounds and
-		 * var_off of the result.
-		 */
-		dst_reg->smin_value = S64_MIN;
-		dst_reg->smax_value = S64_MAX;
-		dst_reg->var_off = tnum_rshift(dst_reg->var_off, umin_val);
-		dst_reg->umin_value >>= umax_val;
-		dst_reg->umax_value >>= umin_val;
-		/* We may learn something more from the var_off */
-		__update_reg_bounds(dst_reg);
+		if (alu32)
+			scalar32_min_max_rsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_rsh(dst_reg, &src_reg);
 		break;
 	case BPF_ARSH:
 		if (umax_val >= insn_bitness) {
@@ -5051,38 +6926,21 @@
 			mark_reg_unknown(env, regs, insn->dst_reg);
 			break;
 		}
-
-		/* Upon reaching here, src_known is true and
-		 * umax_val is equal to umin_val.
-		 */
-		if (insn_bitness == 32) {
-			dst_reg->smin_value = (u32)(((s32)dst_reg->smin_value) >> umin_val);
-			dst_reg->smax_value = (u32)(((s32)dst_reg->smax_value) >> umin_val);
-		} else {
-			dst_reg->smin_value >>= umin_val;
-			dst_reg->smax_value >>= umin_val;
-		}
-
-		dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val,
-						insn_bitness);
-
-		/* blow away the dst_reg umin_value/umax_value and rely on
-		 * dst_reg var_off to refine the result.
-		 */
-		dst_reg->umin_value = 0;
-		dst_reg->umax_value = U64_MAX;
-		__update_reg_bounds(dst_reg);
+		if (alu32)
+			scalar32_min_max_arsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_arsh(dst_reg, &src_reg);
 		break;
 	default:
 		mark_reg_unknown(env, regs, insn->dst_reg);
 		break;
 	}
 
-	if (BPF_CLASS(insn->code) != BPF_ALU64) {
-		/* 32-bit ALU ops are (32,32)->32 */
-		coerce_reg_to_size(dst_reg, 4);
-	}
+	/* ALU32 ops are zero extended into 64bit register */
+	if (alu32)
+		zext_32_to_64(dst_reg);
 
+	__update_reg_bounds(dst_reg);
 	__reg_deduce_bounds(dst_reg);
 	__reg_bound_offset(dst_reg);
 	return 0;
@@ -5105,6 +6963,11 @@
 	src_reg = NULL;
 	if (dst_reg->type != SCALAR_VALUE)
 		ptr_reg = dst_reg;
+	else
+		/* Make sure ID is cleared otherwise dst_reg min/max could be
+		 * incorrectly propagated into other registers by find_equal_scalars()
+		 */
+		dst_reg->id = 0;
 	if (BPF_SRC(insn->code) == BPF_X) {
 		src_reg = &regs[insn->src_reg];
 		if (src_reg->type != SCALAR_VALUE) {
@@ -5238,6 +7101,12 @@
 				/* case: R1 = R2
 				 * copy register state to dest reg
 				 */
+				if (src_reg->type == SCALAR_VALUE && !src_reg->id)
+					/* Assign src and dst registers the same ID
+					 * that will be used by find_equal_scalars()
+					 * to propagate min/max range.
+					 */
+					src_reg->id = ++env->id_gen;
 				*dst_reg = *src_reg;
 				dst_reg->live |= REG_LIVE_WRITTEN;
 				dst_reg->subreg_def = DEF_NOT_SUBREG;
@@ -5250,13 +7119,22 @@
 					return -EACCES;
 				} else if (src_reg->type == SCALAR_VALUE) {
 					*dst_reg = *src_reg;
+					/* Make sure ID is cleared otherwise
+					 * dst_reg min/max could be incorrectly
+					 * propagated into src_reg by find_equal_scalars()
+					 */
+					dst_reg->id = 0;
 					dst_reg->live |= REG_LIVE_WRITTEN;
 					dst_reg->subreg_def = env->insn_idx + 1;
 				} else {
 					mark_reg_unknown(env, regs,
 							 insn->dst_reg);
 				}
-				coerce_reg_to_size(dst_reg, 4);
+				zext_32_to_64(dst_reg);
+
+				__update_reg_bounds(dst_reg);
+				__reg_deduce_bounds(dst_reg);
+				__reg_bound_offset(dst_reg);
 			}
 		} else {
 			/* case: R = imm
@@ -5372,7 +7250,7 @@
 
 	new_range = dst_reg->off;
 	if (range_right_open)
-		new_range--;
+		new_range++;
 
 	/* Examples for register markings:
 	 *
@@ -5426,56 +7304,84 @@
 					 new_range);
 }
 
-/* compute branch direction of the expression "if (reg opcode val) goto target;"
- * and return:
- *  1 - branch will be taken and "goto target" will be executed
- *  0 - branch will not be taken and fall-through to next insn
- * -1 - unknown. Example: "if (reg < 5)" is unknown when register value range [0,10]
- */
-static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
-			   bool is_jmp32)
+static int is_branch32_taken(struct bpf_reg_state *reg, u32 val, u8 opcode)
 {
-	struct bpf_reg_state reg_lo;
-	s64 sval;
+	struct tnum subreg = tnum_subreg(reg->var_off);
+	s32 sval = (s32)val;
 
-	if (__is_pointer_value(false, reg))
-		return -1;
-
-	if (is_jmp32) {
-		reg_lo = *reg;
-		reg = &reg_lo;
-		/* For JMP32, only low 32 bits are compared, coerce_reg_to_size
-		 * could truncate high bits and update umin/umax according to
-		 * information of low bits.
-		 */
-		coerce_reg_to_size(reg, 4);
-		/* smin/smax need special handling. For example, after coerce,
-		 * if smin_value is 0x00000000ffffffffLL, the value is -1 when
-		 * used as operand to JMP32. It is a negative number from s32's
-		 * point of view, while it is a positive number when seen as
-		 * s64. The smin/smax are kept as s64, therefore, when used with
-		 * JMP32, they need to be transformed into s32, then sign
-		 * extended back to s64.
-		 *
-		 * Also, smin/smax were copied from umin/umax. If umin/umax has
-		 * different sign bit, then min/max relationship doesn't
-		 * maintain after casting into s32, for this case, set smin/smax
-		 * to safest range.
-		 */
-		if ((reg->umax_value ^ reg->umin_value) &
-		    (1ULL << 31)) {
-			reg->smin_value = S32_MIN;
-			reg->smax_value = S32_MAX;
-		}
-		reg->smin_value = (s64)(s32)reg->smin_value;
-		reg->smax_value = (s64)(s32)reg->smax_value;
-
-		val = (u32)val;
-		sval = (s64)(s32)val;
-	} else {
-		sval = (s64)val;
+	switch (opcode) {
+	case BPF_JEQ:
+		if (tnum_is_const(subreg))
+			return !!tnum_equals_const(subreg, val);
+		break;
+	case BPF_JNE:
+		if (tnum_is_const(subreg))
+			return !tnum_equals_const(subreg, val);
+		break;
+	case BPF_JSET:
+		if ((~subreg.mask & subreg.value) & val)
+			return 1;
+		if (!((subreg.mask | subreg.value) & val))
+			return 0;
+		break;
+	case BPF_JGT:
+		if (reg->u32_min_value > val)
+			return 1;
+		else if (reg->u32_max_value <= val)
+			return 0;
+		break;
+	case BPF_JSGT:
+		if (reg->s32_min_value > sval)
+			return 1;
+		else if (reg->s32_max_value <= sval)
+			return 0;
+		break;
+	case BPF_JLT:
+		if (reg->u32_max_value < val)
+			return 1;
+		else if (reg->u32_min_value >= val)
+			return 0;
+		break;
+	case BPF_JSLT:
+		if (reg->s32_max_value < sval)
+			return 1;
+		else if (reg->s32_min_value >= sval)
+			return 0;
+		break;
+	case BPF_JGE:
+		if (reg->u32_min_value >= val)
+			return 1;
+		else if (reg->u32_max_value < val)
+			return 0;
+		break;
+	case BPF_JSGE:
+		if (reg->s32_min_value >= sval)
+			return 1;
+		else if (reg->s32_max_value < sval)
+			return 0;
+		break;
+	case BPF_JLE:
+		if (reg->u32_max_value <= val)
+			return 1;
+		else if (reg->u32_min_value > val)
+			return 0;
+		break;
+	case BPF_JSLE:
+		if (reg->s32_max_value <= sval)
+			return 1;
+		else if (reg->s32_min_value > sval)
+			return 0;
+		break;
 	}
 
+	return -1;
+}
+
+
+static int is_branch64_taken(struct bpf_reg_state *reg, u64 val, u8 opcode)
+{
+	s64 sval = (s64)val;
+
 	switch (opcode) {
 	case BPF_JEQ:
 		if (tnum_is_const(reg->var_off))
@@ -5500,7 +7406,7 @@
 	case BPF_JSGT:
 		if (reg->smin_value > sval)
 			return 1;
-		else if (reg->smax_value < sval)
+		else if (reg->smax_value <= sval)
 			return 0;
 		break;
 	case BPF_JLT:
@@ -5544,91 +7450,39 @@
 	return -1;
 }
 
-/* Generate min value of the high 32-bit from TNUM info. */
-static u64 gen_hi_min(struct tnum var)
-{
-	return var.value & ~0xffffffffULL;
-}
-
-/* Generate max value of the high 32-bit from TNUM info. */
-static u64 gen_hi_max(struct tnum var)
-{
-	return (var.value | var.mask) & ~0xffffffffULL;
-}
-
-/* Return true if VAL is compared with a s64 sign extended from s32, and they
- * are with the same signedness.
+/* compute branch direction of the expression "if (reg opcode val) goto target;"
+ * and return:
+ *  1 - branch will be taken and "goto target" will be executed
+ *  0 - branch will not be taken and fall-through to next insn
+ * -1 - unknown. Example: "if (reg < 5)" is unknown when register value
+ *      range [0,10]
  */
-static bool cmp_val_with_extended_s64(s64 sval, struct bpf_reg_state *reg)
+static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
+			   bool is_jmp32)
 {
-	return ((s32)sval >= 0 &&
-		reg->smin_value >= 0 && reg->smax_value <= S32_MAX) ||
-	       ((s32)sval < 0 &&
-		reg->smax_value <= 0 && reg->smin_value >= S32_MIN);
-}
+	if (__is_pointer_value(false, reg)) {
+		if (!reg_type_not_null(reg->type))
+			return -1;
 
-/* Constrain the possible values of @reg with unsigned upper bound @bound.
- * If @is_exclusive, @bound is an exclusive limit, otherwise it is inclusive.
- * If @is_jmp32, @bound is a 32-bit value that only constrains the low 32 bits
- * of @reg.
- */
-static void set_upper_bound(struct bpf_reg_state *reg, u64 bound, bool is_jmp32,
-			    bool is_exclusive)
-{
-	if (is_exclusive) {
-		/* There are no values for `reg` that make `reg<0` true. */
-		if (bound == 0)
-			return;
-		bound--;
-	}
-	if (is_jmp32) {
-		/* Constrain the register's value in the tnum representation.
-		 * For 64-bit comparisons this happens later in
-		 * __reg_bound_offset(), but for 32-bit comparisons, we can be
-		 * more precise than what can be derived from the updated
-		 * numeric bounds.
+		/* If pointer is valid tests against zero will fail so we can
+		 * use this to direct branch taken.
 		 */
-		struct tnum t = tnum_range(0, bound);
+		if (val != 0)
+			return -1;
 
-		t.mask |= ~0xffffffffULL; /* upper half is unknown */
-		reg->var_off = tnum_intersect(reg->var_off, t);
-
-		/* Compute the 64-bit bound from the 32-bit bound. */
-		bound += gen_hi_max(reg->var_off);
+		switch (opcode) {
+		case BPF_JEQ:
+			return 0;
+		case BPF_JNE:
+			return 1;
+		default:
+			return -1;
+		}
 	}
-	reg->umax_value = min(reg->umax_value, bound);
-}
 
-/* Constrain the possible values of @reg with unsigned lower bound @bound.
- * If @is_exclusive, @bound is an exclusive limit, otherwise it is inclusive.
- * If @is_jmp32, @bound is a 32-bit value that only constrains the low 32 bits
- * of @reg.
- */
-static void set_lower_bound(struct bpf_reg_state *reg, u64 bound, bool is_jmp32,
-			    bool is_exclusive)
-{
-	if (is_exclusive) {
-		/* There are no values for `reg` that make `reg>MAX` true. */
-		if (bound == (is_jmp32 ? U32_MAX : U64_MAX))
-			return;
-		bound++;
-	}
-	if (is_jmp32) {
-		/* Constrain the register's value in the tnum representation.
-		 * For 64-bit comparisons this happens later in
-		 * __reg_bound_offset(), but for 32-bit comparisons, we can be
-		 * more precise than what can be derived from the updated
-		 * numeric bounds.
-		 */
-		struct tnum t = tnum_range(bound, U32_MAX);
-
-		t.mask |= ~0xffffffffULL; /* upper half is unknown */
-		reg->var_off = tnum_intersect(reg->var_off, t);
-
-		/* Compute the 64-bit bound from the 32-bit bound. */
-		bound += gen_hi_min(reg->var_off);
-	}
-	reg->umin_value = max(reg->umin_value, bound);
+	if (is_jmp32)
+		return is_branch32_taken(reg, val, opcode);
+	return is_branch64_taken(reg, val, opcode);
 }
 
 /* Adjusts the register min/max values in the case that the dst_reg is the
@@ -5637,10 +7491,16 @@
  * In JEQ/JNE cases we also adjust the var_off values.
  */
 static void reg_set_min_max(struct bpf_reg_state *true_reg,
-			    struct bpf_reg_state *false_reg, u64 val,
+			    struct bpf_reg_state *false_reg,
+			    u64 val, u32 val32,
 			    u8 opcode, bool is_jmp32)
 {
-	s64 sval;
+	struct tnum false_32off = tnum_subreg(false_reg->var_off);
+	struct tnum false_64off = false_reg->var_off;
+	struct tnum true_32off = tnum_subreg(true_reg->var_off);
+	struct tnum true_64off = true_reg->var_off;
+	s64 sval = (s64)val;
+	s32 sval32 = (s32)val32;
 
 	/* If the dst_reg is a pointer, we can't learn anything about its
 	 * variable offset from the compare (unless src_reg were a pointer into
@@ -5651,9 +7511,6 @@
 	if (__is_pointer_value(false, false_reg))
 		return;
 
-	val = is_jmp32 ? (u32)val : val;
-	sval = is_jmp32 ? (s64)(s32)val : (s64)val;
-
 	switch (opcode) {
 	case BPF_JEQ:
 	case BPF_JNE:
@@ -5661,179 +7518,158 @@
 		struct bpf_reg_state *reg =
 			opcode == BPF_JEQ ? true_reg : false_reg;
 
-		/* For BPF_JEQ, if this is false we know nothing Jon Snow, but
-		 * if it is true we know the value for sure. Likewise for
-		 * BPF_JNE.
+		/* JEQ/JNE comparison doesn't change the register equivalence.
+		 * r1 = r2;
+		 * if (r1 == 42) goto label;
+		 * ...
+		 * label: // here both r1 and r2 are known to be 42.
+		 *
+		 * Hence when marking register as known preserve it's ID.
 		 */
-		if (is_jmp32) {
-			u64 old_v = reg->var_off.value;
-			u64 hi_mask = ~0xffffffffULL;
-
-			reg->var_off.value = (old_v & hi_mask) | val;
-			reg->var_off.mask &= hi_mask;
-		} else {
-			__mark_reg_known(reg, val);
-		}
+		if (is_jmp32)
+			__mark_reg32_known(reg, val32);
+		else
+			___mark_reg_known(reg, val);
 		break;
 	}
 	case BPF_JSET:
-		false_reg->var_off = tnum_and(false_reg->var_off,
-					      tnum_const(~val));
-		if (is_power_of_2(val))
-			true_reg->var_off = tnum_or(true_reg->var_off,
-						    tnum_const(val));
+		if (is_jmp32) {
+			false_32off = tnum_and(false_32off, tnum_const(~val32));
+			if (is_power_of_2(val32))
+				true_32off = tnum_or(true_32off,
+						     tnum_const(val32));
+		} else {
+			false_64off = tnum_and(false_64off, tnum_const(~val));
+			if (is_power_of_2(val))
+				true_64off = tnum_or(true_64off,
+						     tnum_const(val));
+		}
 		break;
 	case BPF_JGE:
 	case BPF_JGT:
 	{
-		set_upper_bound(false_reg, val, is_jmp32, opcode == BPF_JGE);
-		set_lower_bound(true_reg, val, is_jmp32, opcode == BPF_JGT);
+		if (is_jmp32) {
+			u32 false_umax = opcode == BPF_JGT ? val32  : val32 - 1;
+			u32 true_umin = opcode == BPF_JGT ? val32 + 1 : val32;
+
+			false_reg->u32_max_value = min(false_reg->u32_max_value,
+						       false_umax);
+			true_reg->u32_min_value = max(true_reg->u32_min_value,
+						      true_umin);
+		} else {
+			u64 false_umax = opcode == BPF_JGT ? val    : val - 1;
+			u64 true_umin = opcode == BPF_JGT ? val + 1 : val;
+
+			false_reg->umax_value = min(false_reg->umax_value, false_umax);
+			true_reg->umin_value = max(true_reg->umin_value, true_umin);
+		}
 		break;
 	}
 	case BPF_JSGE:
 	case BPF_JSGT:
 	{
-		s64 false_smax = opcode == BPF_JSGT ? sval    : sval - 1;
-		s64 true_smin = opcode == BPF_JSGT ? sval + 1 : sval;
+		if (is_jmp32) {
+			s32 false_smax = opcode == BPF_JSGT ? sval32    : sval32 - 1;
+			s32 true_smin = opcode == BPF_JSGT ? sval32 + 1 : sval32;
 
-		/* If the full s64 was not sign-extended from s32 then don't
-		 * deduct further info.
-		 */
-		if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg))
-			break;
-		false_reg->smax_value = min(false_reg->smax_value, false_smax);
-		true_reg->smin_value = max(true_reg->smin_value, true_smin);
+			false_reg->s32_max_value = min(false_reg->s32_max_value, false_smax);
+			true_reg->s32_min_value = max(true_reg->s32_min_value, true_smin);
+		} else {
+			s64 false_smax = opcode == BPF_JSGT ? sval    : sval - 1;
+			s64 true_smin = opcode == BPF_JSGT ? sval + 1 : sval;
+
+			false_reg->smax_value = min(false_reg->smax_value, false_smax);
+			true_reg->smin_value = max(true_reg->smin_value, true_smin);
+		}
 		break;
 	}
 	case BPF_JLE:
 	case BPF_JLT:
 	{
-		set_lower_bound(false_reg, val, is_jmp32, opcode == BPF_JLE);
-		set_upper_bound(true_reg, val, is_jmp32, opcode == BPF_JLT);
+		if (is_jmp32) {
+			u32 false_umin = opcode == BPF_JLT ? val32  : val32 + 1;
+			u32 true_umax = opcode == BPF_JLT ? val32 - 1 : val32;
+
+			false_reg->u32_min_value = max(false_reg->u32_min_value,
+						       false_umin);
+			true_reg->u32_max_value = min(true_reg->u32_max_value,
+						      true_umax);
+		} else {
+			u64 false_umin = opcode == BPF_JLT ? val    : val + 1;
+			u64 true_umax = opcode == BPF_JLT ? val - 1 : val;
+
+			false_reg->umin_value = max(false_reg->umin_value, false_umin);
+			true_reg->umax_value = min(true_reg->umax_value, true_umax);
+		}
 		break;
 	}
 	case BPF_JSLE:
 	case BPF_JSLT:
 	{
-		s64 false_smin = opcode == BPF_JSLT ? sval    : sval + 1;
-		s64 true_smax = opcode == BPF_JSLT ? sval - 1 : sval;
+		if (is_jmp32) {
+			s32 false_smin = opcode == BPF_JSLT ? sval32    : sval32 + 1;
+			s32 true_smax = opcode == BPF_JSLT ? sval32 - 1 : sval32;
 
-		if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg))
-			break;
-		false_reg->smin_value = max(false_reg->smin_value, false_smin);
-		true_reg->smax_value = min(true_reg->smax_value, true_smax);
+			false_reg->s32_min_value = max(false_reg->s32_min_value, false_smin);
+			true_reg->s32_max_value = min(true_reg->s32_max_value, true_smax);
+		} else {
+			s64 false_smin = opcode == BPF_JSLT ? sval    : sval + 1;
+			s64 true_smax = opcode == BPF_JSLT ? sval - 1 : sval;
+
+			false_reg->smin_value = max(false_reg->smin_value, false_smin);
+			true_reg->smax_value = min(true_reg->smax_value, true_smax);
+		}
 		break;
 	}
 	default:
-		break;
+		return;
 	}
 
-	__reg_deduce_bounds(false_reg);
-	__reg_deduce_bounds(true_reg);
-	/* We might have learned some bits from the bounds. */
-	__reg_bound_offset(false_reg);
-	__reg_bound_offset(true_reg);
-	/* Intersecting with the old var_off might have improved our bounds
-	 * slightly.  e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
-	 * then new var_off is (0; 0x7f...fc) which improves our umax.
-	 */
-	__update_reg_bounds(false_reg);
-	__update_reg_bounds(true_reg);
+	if (is_jmp32) {
+		false_reg->var_off = tnum_or(tnum_clear_subreg(false_64off),
+					     tnum_subreg(false_32off));
+		true_reg->var_off = tnum_or(tnum_clear_subreg(true_64off),
+					    tnum_subreg(true_32off));
+		__reg_combine_32_into_64(false_reg);
+		__reg_combine_32_into_64(true_reg);
+	} else {
+		false_reg->var_off = false_64off;
+		true_reg->var_off = true_64off;
+		__reg_combine_64_into_32(false_reg);
+		__reg_combine_64_into_32(true_reg);
+	}
 }
 
 /* Same as above, but for the case that dst_reg holds a constant and src_reg is
  * the variable reg.
  */
 static void reg_set_min_max_inv(struct bpf_reg_state *true_reg,
-				struct bpf_reg_state *false_reg, u64 val,
+				struct bpf_reg_state *false_reg,
+				u64 val, u32 val32,
 				u8 opcode, bool is_jmp32)
 {
-	s64 sval;
-
-	if (__is_pointer_value(false, false_reg))
-		return;
-
-	val = is_jmp32 ? (u32)val : val;
-	sval = is_jmp32 ? (s64)(s32)val : (s64)val;
-
-	switch (opcode) {
-	case BPF_JEQ:
-	case BPF_JNE:
-	{
-		struct bpf_reg_state *reg =
-			opcode == BPF_JEQ ? true_reg : false_reg;
-
-		if (is_jmp32) {
-			u64 old_v = reg->var_off.value;
-			u64 hi_mask = ~0xffffffffULL;
-
-			reg->var_off.value = (old_v & hi_mask) | val;
-			reg->var_off.mask &= hi_mask;
-		} else {
-			__mark_reg_known(reg, val);
-		}
-		break;
-	}
-	case BPF_JSET:
-		false_reg->var_off = tnum_and(false_reg->var_off,
-					      tnum_const(~val));
-		if (is_power_of_2(val))
-			true_reg->var_off = tnum_or(true_reg->var_off,
-						    tnum_const(val));
-		break;
-	case BPF_JGE:
-	case BPF_JGT:
-	{
-		set_lower_bound(false_reg, val, is_jmp32, opcode == BPF_JGE);
-		set_upper_bound(true_reg, val, is_jmp32, opcode == BPF_JGT);
-		break;
-	}
-	case BPF_JSGE:
-	case BPF_JSGT:
-	{
-		s64 false_smin = opcode == BPF_JSGT ? sval    : sval + 1;
-		s64 true_smax = opcode == BPF_JSGT ? sval - 1 : sval;
-
-		if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg))
-			break;
-		false_reg->smin_value = max(false_reg->smin_value, false_smin);
-		true_reg->smax_value = min(true_reg->smax_value, true_smax);
-		break;
-	}
-	case BPF_JLE:
-	case BPF_JLT:
-	{
-		set_upper_bound(false_reg, val, is_jmp32, opcode == BPF_JLE);
-		set_lower_bound(true_reg, val, is_jmp32, opcode == BPF_JLT);
-		break;
-	}
-	case BPF_JSLE:
-	case BPF_JSLT:
-	{
-		s64 false_smax = opcode == BPF_JSLT ? sval    : sval - 1;
-		s64 true_smin = opcode == BPF_JSLT ? sval + 1 : sval;
-
-		if (is_jmp32 && !cmp_val_with_extended_s64(sval, false_reg))
-			break;
-		false_reg->smax_value = min(false_reg->smax_value, false_smax);
-		true_reg->smin_value = max(true_reg->smin_value, true_smin);
-		break;
-	}
-	default:
-		break;
-	}
-
-	__reg_deduce_bounds(false_reg);
-	__reg_deduce_bounds(true_reg);
-	/* We might have learned some bits from the bounds. */
-	__reg_bound_offset(false_reg);
-	__reg_bound_offset(true_reg);
-	/* Intersecting with the old var_off might have improved our bounds
-	 * slightly.  e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
-	 * then new var_off is (0; 0x7f...fc) which improves our umax.
+	/* How can we transform "a <op> b" into "b <op> a"? */
+	static const u8 opcode_flip[16] = {
+		/* these stay the same */
+		[BPF_JEQ  >> 4] = BPF_JEQ,
+		[BPF_JNE  >> 4] = BPF_JNE,
+		[BPF_JSET >> 4] = BPF_JSET,
+		/* these swap "lesser" and "greater" (L and G in the opcodes) */
+		[BPF_JGE  >> 4] = BPF_JLE,
+		[BPF_JGT  >> 4] = BPF_JLT,
+		[BPF_JLE  >> 4] = BPF_JGE,
+		[BPF_JLT  >> 4] = BPF_JGT,
+		[BPF_JSGE >> 4] = BPF_JSLE,
+		[BPF_JSGT >> 4] = BPF_JSLT,
+		[BPF_JSLE >> 4] = BPF_JSGE,
+		[BPF_JSLT >> 4] = BPF_JSGT
+	};
+	opcode = opcode_flip[opcode >> 4];
+	/* This uses zero as "not present in table"; luckily the zero opcode,
+	 * BPF_JA, can't get here.
 	 */
-	__update_reg_bounds(false_reg);
-	__update_reg_bounds(true_reg);
+	if (opcode)
+		reg_set_min_max(true_reg, false_reg, val, val32, opcode, is_jmp32);
 }
 
 /* Regs are known to be equal, so intersect their min/max/var_off */
@@ -5887,26 +7723,31 @@
 				 struct bpf_reg_state *reg, u32 id,
 				 bool is_null)
 {
-	if (reg_type_may_be_null(reg->type) && reg->id == id) {
-		/* Old offset (both fixed and variable parts) should
-		 * have been known-zero, because we don't allow pointer
-		 * arithmetic on pointers that might be NULL.
-		 */
+	if (reg_type_may_be_null(reg->type) && reg->id == id &&
+	    !WARN_ON_ONCE(!reg->id)) {
 		if (WARN_ON_ONCE(reg->smin_value || reg->smax_value ||
 				 !tnum_equals_const(reg->var_off, 0) ||
 				 reg->off)) {
-			__mark_reg_known_zero(reg);
-			reg->off = 0;
+			/* Old offset (both fixed and variable parts) should
+			 * have been known-zero, because we don't allow pointer
+			 * arithmetic on pointers that might be NULL. If we
+			 * see this happening, don't convert the register.
+			 */
+			return;
 		}
 		if (is_null) {
 			reg->type = SCALAR_VALUE;
 		} else if (reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
-			if (reg->map_ptr->inner_map_meta) {
+			const struct bpf_map *map = reg->map_ptr;
+
+			if (map->inner_map_meta) {
 				reg->type = CONST_PTR_TO_MAP;
-				reg->map_ptr = reg->map_ptr->inner_map_meta;
-			} else if (reg->map_ptr->map_type ==
-				   BPF_MAP_TYPE_XSKMAP) {
+				reg->map_ptr = map->inner_map_meta;
+			} else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
 				reg->type = PTR_TO_XDP_SOCK;
+			} else if (map->map_type == BPF_MAP_TYPE_SOCKMAP ||
+				   map->map_type == BPF_MAP_TYPE_SOCKHASH) {
+				reg->type = PTR_TO_SOCKET;
 			} else {
 				reg->type = PTR_TO_MAP_VALUE;
 			}
@@ -5916,6 +7757,14 @@
 			reg->type = PTR_TO_SOCK_COMMON;
 		} else if (reg->type == PTR_TO_TCP_SOCK_OR_NULL) {
 			reg->type = PTR_TO_TCP_SOCK;
+		} else if (reg->type == PTR_TO_BTF_ID_OR_NULL) {
+			reg->type = PTR_TO_BTF_ID;
+		} else if (reg->type == PTR_TO_MEM_OR_NULL) {
+			reg->type = PTR_TO_MEM;
+		} else if (reg->type == PTR_TO_RDONLY_BUF_OR_NULL) {
+			reg->type = PTR_TO_RDONLY_BUF;
+		} else if (reg->type == PTR_TO_RDWR_BUF_OR_NULL) {
+			reg->type = PTR_TO_RDWR_BUF;
 		}
 		if (is_null) {
 			/* We don't need id and ref_obj_id from this point
@@ -6072,6 +7921,30 @@
 	return true;
 }
 
+static void find_equal_scalars(struct bpf_verifier_state *vstate,
+			       struct bpf_reg_state *known_reg)
+{
+	struct bpf_func_state *state;
+	struct bpf_reg_state *reg;
+	int i, j;
+
+	for (i = 0; i <= vstate->curframe; i++) {
+		state = vstate->frame[i];
+		for (j = 0; j < MAX_BPF_REG; j++) {
+			reg = &state->regs[j];
+			if (reg->type == SCALAR_VALUE && reg->id == known_reg->id)
+				*reg = *known_reg;
+		}
+
+		bpf_for_each_spilled_reg(j, state, reg) {
+			if (!reg)
+				continue;
+			if (reg->type == SCALAR_VALUE && reg->id == known_reg->id)
+				*reg = *known_reg;
+		}
+	}
+}
+
 static int check_cond_jmp_op(struct bpf_verifier_env *env,
 			     struct bpf_insn *insn, int *insn_idx)
 {
@@ -6122,15 +7995,28 @@
 	dst_reg = &regs[insn->dst_reg];
 	is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
 
-	if (BPF_SRC(insn->code) == BPF_K)
-		pred = is_branch_taken(dst_reg, insn->imm,
-				       opcode, is_jmp32);
-	else if (src_reg->type == SCALAR_VALUE &&
-		 tnum_is_const(src_reg->var_off))
-		pred = is_branch_taken(dst_reg, src_reg->var_off.value,
-				       opcode, is_jmp32);
+	if (BPF_SRC(insn->code) == BPF_K) {
+		pred = is_branch_taken(dst_reg, insn->imm, opcode, is_jmp32);
+	} else if (src_reg->type == SCALAR_VALUE &&
+		   is_jmp32 && tnum_is_const(tnum_subreg(src_reg->var_off))) {
+		pred = is_branch_taken(dst_reg,
+				       tnum_subreg(src_reg->var_off).value,
+				       opcode,
+				       is_jmp32);
+	} else if (src_reg->type == SCALAR_VALUE &&
+		   !is_jmp32 && tnum_is_const(src_reg->var_off)) {
+		pred = is_branch_taken(dst_reg,
+				       src_reg->var_off.value,
+				       opcode,
+				       is_jmp32);
+	}
+
 	if (pred >= 0) {
-		err = mark_chain_precision(env, insn->dst_reg);
+		/* If we get here with a dst_reg pointer type it is because
+		 * above is_branch_taken() special cased the 0 comparison.
+		 */
+		if (!__is_pointer_value(false, dst_reg))
+			err = mark_chain_precision(env, insn->dst_reg);
 		if (BPF_SRC(insn->code) == BPF_X && !err)
 			err = mark_chain_precision(env, insn->src_reg);
 		if (err)
@@ -6142,7 +8028,7 @@
 		 * the fall-through branch for simulation under speculative
 		 * execution.
 		 */
-		if (!env->allow_ptr_leaks &&
+		if (!env->bypass_spec_v1 &&
 		    !sanitize_speculative_path(env, insn, *insn_idx + 1,
 					       *insn_idx))
 			return -EFAULT;
@@ -6153,7 +8039,7 @@
 		 * program will go. If needed, push the goto branch for
 		 * simulation under speculative execution.
 		 */
-		if (!env->allow_ptr_leaks &&
+		if (!env->bypass_spec_v1 &&
 		    !sanitize_speculative_path(env, insn,
 					       *insn_idx + insn->off + 1,
 					       *insn_idx))
@@ -6176,32 +8062,24 @@
 	 */
 	if (BPF_SRC(insn->code) == BPF_X) {
 		struct bpf_reg_state *src_reg = &regs[insn->src_reg];
-		struct bpf_reg_state lo_reg0 = *dst_reg;
-		struct bpf_reg_state lo_reg1 = *src_reg;
-		struct bpf_reg_state *src_lo, *dst_lo;
-
-		dst_lo = &lo_reg0;
-		src_lo = &lo_reg1;
-		coerce_reg_to_size(dst_lo, 4);
-		coerce_reg_to_size(src_lo, 4);
 
 		if (dst_reg->type == SCALAR_VALUE &&
 		    src_reg->type == SCALAR_VALUE) {
 			if (tnum_is_const(src_reg->var_off) ||
-			    (is_jmp32 && tnum_is_const(src_lo->var_off)))
+			    (is_jmp32 &&
+			     tnum_is_const(tnum_subreg(src_reg->var_off))))
 				reg_set_min_max(&other_branch_regs[insn->dst_reg],
 						dst_reg,
-						is_jmp32
-						? src_lo->var_off.value
-						: src_reg->var_off.value,
+						src_reg->var_off.value,
+						tnum_subreg(src_reg->var_off).value,
 						opcode, is_jmp32);
 			else if (tnum_is_const(dst_reg->var_off) ||
-				 (is_jmp32 && tnum_is_const(dst_lo->var_off)))
+				 (is_jmp32 &&
+				  tnum_is_const(tnum_subreg(dst_reg->var_off))))
 				reg_set_min_max_inv(&other_branch_regs[insn->src_reg],
 						    src_reg,
-						    is_jmp32
-						    ? dst_lo->var_off.value
-						    : dst_reg->var_off.value,
+						    dst_reg->var_off.value,
+						    tnum_subreg(dst_reg->var_off).value,
 						    opcode, is_jmp32);
 			else if (!is_jmp32 &&
 				 (opcode == BPF_JEQ || opcode == BPF_JNE))
@@ -6209,10 +8087,23 @@
 				reg_combine_min_max(&other_branch_regs[insn->src_reg],
 						    &other_branch_regs[insn->dst_reg],
 						    src_reg, dst_reg, opcode);
+			if (src_reg->id &&
+			    !WARN_ON_ONCE(src_reg->id != other_branch_regs[insn->src_reg].id)) {
+				find_equal_scalars(this_branch, src_reg);
+				find_equal_scalars(other_branch, &other_branch_regs[insn->src_reg]);
+			}
+
 		}
 	} else if (dst_reg->type == SCALAR_VALUE) {
 		reg_set_min_max(&other_branch_regs[insn->dst_reg],
-					dst_reg, insn->imm, opcode, is_jmp32);
+					dst_reg, insn->imm, (u32)insn->imm,
+					opcode, is_jmp32);
+	}
+
+	if (dst_reg->type == SCALAR_VALUE && dst_reg->id &&
+	    !WARN_ON_ONCE(dst_reg->id != other_branch_regs[insn->dst_reg].id)) {
+		find_equal_scalars(this_branch, dst_reg);
+		find_equal_scalars(other_branch, &other_branch_regs[insn->dst_reg]);
 	}
 
 	/* detect if R == 0 where R is returned from bpf_map_lookup_elem().
@@ -6246,6 +8137,7 @@
 {
 	struct bpf_insn_aux_data *aux = cur_aux(env);
 	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_reg_state *dst_reg;
 	struct bpf_map *map;
 	int err;
 
@@ -6262,25 +8154,45 @@
 	if (err)
 		return err;
 
+	dst_reg = &regs[insn->dst_reg];
 	if (insn->src_reg == 0) {
 		u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
 
-		regs[insn->dst_reg].type = SCALAR_VALUE;
+		dst_reg->type = SCALAR_VALUE;
 		__mark_reg_known(&regs[insn->dst_reg], imm);
 		return 0;
 	}
 
+	if (insn->src_reg == BPF_PSEUDO_BTF_ID) {
+		mark_reg_known_zero(env, regs, insn->dst_reg);
+
+		dst_reg->type = aux->btf_var.reg_type;
+		switch (dst_reg->type) {
+		case PTR_TO_MEM:
+			dst_reg->mem_size = aux->btf_var.mem_size;
+			break;
+		case PTR_TO_BTF_ID:
+		case PTR_TO_PERCPU_BTF_ID:
+			dst_reg->btf_id = aux->btf_var.btf_id;
+			break;
+		default:
+			verbose(env, "bpf verifier is misconfigured\n");
+			return -EFAULT;
+		}
+		return 0;
+	}
+
 	map = env->used_maps[aux->map_index];
 	mark_reg_known_zero(env, regs, insn->dst_reg);
-	regs[insn->dst_reg].map_ptr = map;
+	dst_reg->map_ptr = map;
 
 	if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) {
-		regs[insn->dst_reg].type = PTR_TO_MAP_VALUE;
-		regs[insn->dst_reg].off = aux->map_off;
+		dst_reg->type = PTR_TO_MAP_VALUE;
+		dst_reg->off = aux->map_off;
 		if (map_value_has_spin_lock(map))
-			regs[insn->dst_reg].id = ++env->id_gen;
+			dst_reg->id = ++env->id_gen;
 	} else if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
-		regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
+		dst_reg->type = CONST_PTR_TO_MAP;
 	} else {
 		verbose(env, "bpf verifier is misconfigured\n");
 		return -EINVAL;
@@ -6323,7 +8235,7 @@
 	u8 mode = BPF_MODE(insn->code);
 	int i, err;
 
-	if (!may_access_skb(env->prog->type)) {
+	if (!may_access_skb(resolve_prog_type(env->prog))) {
 		verbose(env, "BPF_LD_[ABS|IND] instructions not allowed for this program type\n");
 		return -EINVAL;
 	}
@@ -6333,18 +8245,6 @@
 		return -EINVAL;
 	}
 
-	if (env->subprog_cnt > 1) {
-		/* when program has LD_ABS insn JITs and interpreter assume
-		 * that r1 == ctx == skb which is not the case for callees
-		 * that can have arbitrary arguments. It's problematic
-		 * for main prog as well since JITs would need to analyze
-		 * all functions in order to make proper register save/restore
-		 * decisions in the main prog. Hence disallow LD_ABS with calls
-		 */
-		verbose(env, "BPF_LD_[ABS|IND] instructions cannot be mixed with bpf-to-bpf calls\n");
-		return -EINVAL;
-	}
-
 	if (insn->dst_reg != BPF_REG_0 || insn->off != 0 ||
 	    BPF_SIZE(insn->code) == BPF_DW ||
 	    (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) {
@@ -6408,13 +8308,53 @@
 static int check_return_code(struct bpf_verifier_env *env)
 {
 	struct tnum enforce_attach_type_range = tnum_unknown;
+	const struct bpf_prog *prog = env->prog;
 	struct bpf_reg_state *reg;
 	struct tnum range = tnum_range(0, 1);
+	enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
+	int err;
+	const bool is_subprog = env->cur_state->frame[0]->subprogno;
 
-	switch (env->prog->type) {
+	/* LSM and struct_ops func-ptr's return type could be "void" */
+	if (!is_subprog &&
+	    (prog_type == BPF_PROG_TYPE_STRUCT_OPS ||
+	     prog_type == BPF_PROG_TYPE_LSM) &&
+	    !prog->aux->attach_func_proto->type)
+		return 0;
+
+	/* eBPF calling convetion is such that R0 is used
+	 * to return the value from eBPF program.
+	 * Make sure that it's readable at this time
+	 * of bpf_exit, which means that program wrote
+	 * something into it earlier
+	 */
+	err = check_reg_arg(env, BPF_REG_0, SRC_OP);
+	if (err)
+		return err;
+
+	if (is_pointer_value(env, BPF_REG_0)) {
+		verbose(env, "R0 leaks addr as return value\n");
+		return -EACCES;
+	}
+
+	reg = cur_regs(env) + BPF_REG_0;
+	if (is_subprog) {
+		if (reg->type != SCALAR_VALUE) {
+			verbose(env, "At subprogram exit the register R0 is not a scalar value (%s)\n",
+				reg_type_str[reg->type]);
+			return -EINVAL;
+		}
+		return 0;
+	}
+
+	switch (prog_type) {
 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
 		if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG ||
-		    env->prog->expected_attach_type == BPF_CGROUP_UDP6_RECVMSG)
+		    env->prog->expected_attach_type == BPF_CGROUP_UDP6_RECVMSG ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET4_GETPEERNAME ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET6_GETPEERNAME ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET4_GETSOCKNAME ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET6_GETSOCKNAME)
 			range = tnum_range(1, 1);
 		break;
 	case BPF_PROG_TYPE_CGROUP_SKB:
@@ -6429,11 +8369,37 @@
 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
 		break;
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+		if (!env->prog->aux->attach_btf_id)
+			return 0;
+		range = tnum_const(0);
+		break;
+	case BPF_PROG_TYPE_TRACING:
+		switch (env->prog->expected_attach_type) {
+		case BPF_TRACE_FENTRY:
+		case BPF_TRACE_FEXIT:
+			range = tnum_const(0);
+			break;
+		case BPF_TRACE_RAW_TP:
+		case BPF_MODIFY_RETURN:
+			return 0;
+		case BPF_TRACE_ITER:
+			break;
+		default:
+			return -ENOTSUPP;
+		}
+		break;
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		range = tnum_range(SK_DROP, SK_PASS);
+		break;
+	case BPF_PROG_TYPE_EXT:
+		/* freplace program can return anything as its return value
+		 * depends on the to-be-replaced kernel func or bpf program.
+		 */
 	default:
 		return 0;
 	}
 
-	reg = cur_regs(env) + BPF_REG_0;
 	if (reg->type != SCALAR_VALUE) {
 		verbose(env, "At program exit the register R0 is not a known value (%s)\n",
 			reg_type_str[reg->type]);
@@ -6557,7 +8523,7 @@
 		insn_stack[env->cfg.cur_stack++] = w;
 		return 1;
 	} else if ((insn_state[w] & 0xF0) == DISCOVERED) {
-		if (loop_ok && env->allow_ptr_leaks)
+		if (loop_ok && env->bpf_capable)
 			return 0;
 		verbose_linfo(env, t, "%d: ", t);
 		verbose_linfo(env, w, "%d: ", w);
@@ -6700,6 +8666,23 @@
 	return ret;
 }
 
+static int check_abnormal_return(struct bpf_verifier_env *env)
+{
+	int i;
+
+	for (i = 1; i < env->subprog_cnt; i++) {
+		if (env->subprog_info[i].has_ld_abs) {
+			verbose(env, "LD_ABS is not allowed in subprogs without BTF\n");
+			return -EINVAL;
+		}
+		if (env->subprog_info[i].has_tail_call) {
+			verbose(env, "tail_call is not allowed in subprogs without BTF\n");
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
 /* The minimum supported BTF func info size */
 #define MIN_BPF_FUNCINFO_SIZE	8
 #define MAX_FUNCINFO_REC_SIZE	252
@@ -6708,19 +8691,24 @@
 			  const union bpf_attr *attr,
 			  union bpf_attr __user *uattr)
 {
+	const struct btf_type *type, *func_proto, *ret_type;
 	u32 i, nfuncs, urec_size, min_size;
 	u32 krec_size = sizeof(struct bpf_func_info);
 	struct bpf_func_info *krecord;
-	const struct btf_type *type;
+	struct bpf_func_info_aux *info_aux = NULL;
 	struct bpf_prog *prog;
 	const struct btf *btf;
 	void __user *urecord;
 	u32 prev_offset = 0;
-	int ret = 0;
+	bool scalar_return;
+	int ret = -ENOMEM;
 
 	nfuncs = attr->func_info_cnt;
-	if (!nfuncs)
+	if (!nfuncs) {
+		if (check_abnormal_return(env))
+			return -EINVAL;
 		return 0;
+	}
 
 	if (nfuncs != env->subprog_cnt) {
 		verbose(env, "number of funcs in func_info doesn't match number of subprogs\n");
@@ -6744,6 +8732,9 @@
 	krecord = kvcalloc(nfuncs, krec_size, GFP_KERNEL | __GFP_NOWARN);
 	if (!krecord)
 		return -ENOMEM;
+	info_aux = kcalloc(nfuncs, sizeof(*info_aux), GFP_KERNEL | __GFP_NOWARN);
+	if (!info_aux)
+		goto err_free;
 
 	for (i = 0; i < nfuncs; i++) {
 		ret = bpf_check_uarg_tail_zero(urecord, krec_size, urec_size);
@@ -6765,34 +8756,48 @@
 		}
 
 		/* check insn_off */
+		ret = -EINVAL;
 		if (i == 0) {
 			if (krecord[i].insn_off) {
 				verbose(env,
 					"nonzero insn_off %u for the first func info record",
 					krecord[i].insn_off);
-				ret = -EINVAL;
 				goto err_free;
 			}
 		} else if (krecord[i].insn_off <= prev_offset) {
 			verbose(env,
 				"same or smaller insn offset (%u) than previous func info record (%u)",
 				krecord[i].insn_off, prev_offset);
-			ret = -EINVAL;
 			goto err_free;
 		}
 
 		if (env->subprog_info[i].start != krecord[i].insn_off) {
 			verbose(env, "func_info BTF section doesn't match subprog layout in BPF program\n");
-			ret = -EINVAL;
 			goto err_free;
 		}
 
 		/* check type_id */
 		type = btf_type_by_id(btf, krecord[i].type_id);
-		if (!type || BTF_INFO_KIND(type->info) != BTF_KIND_FUNC) {
+		if (!type || !btf_type_is_func(type)) {
 			verbose(env, "invalid type id %d in func info",
 				krecord[i].type_id);
-			ret = -EINVAL;
+			goto err_free;
+		}
+		info_aux[i].linkage = BTF_INFO_VLEN(type->info);
+
+		func_proto = btf_type_by_id(btf, type->type);
+		if (unlikely(!func_proto || !btf_type_is_func_proto(func_proto)))
+			/* btf_func_check() already verified it during BTF load */
+			goto err_free;
+		ret_type = btf_type_skip_modifiers(btf, func_proto->type, NULL);
+		scalar_return =
+			btf_type_is_small_int(ret_type) || btf_type_is_enum(ret_type);
+		if (i && !scalar_return && env->subprog_info[i].has_ld_abs) {
+			verbose(env, "LD_ABS is only allowed in functions that return 'int'.\n");
+			goto err_free;
+		}
+		if (i && !scalar_return && env->subprog_info[i].has_tail_call) {
+			verbose(env, "tail_call is only allowed in functions that return 'int'.\n");
 			goto err_free;
 		}
 
@@ -6802,22 +8807,25 @@
 
 	prog->aux->func_info = krecord;
 	prog->aux->func_info_cnt = nfuncs;
+	prog->aux->func_info_aux = info_aux;
 	return 0;
 
 err_free:
 	kvfree(krecord);
+	kfree(info_aux);
 	return ret;
 }
 
 static void adjust_btf_func(struct bpf_verifier_env *env)
 {
+	struct bpf_prog_aux *aux = env->prog->aux;
 	int i;
 
-	if (!env->prog->aux->func_info)
+	if (!aux->func_info)
 		return;
 
 	for (i = 0; i < env->subprog_cnt; i++)
-		env->prog->aux->func_info[i].insn_off = env->subprog_info[i].start;
+		aux->func_info[i].insn_off = env->subprog_info[i].start;
 }
 
 #define MIN_BPF_LINEINFO_SIZE	(offsetof(struct bpf_line_info, line_col) + \
@@ -6839,6 +8847,8 @@
 	nr_linfo = attr->line_info_cnt;
 	if (!nr_linfo)
 		return 0;
+	if (nr_linfo > INT_MAX / sizeof(struct bpf_line_info))
+		return -EINVAL;
 
 	rec_size = attr->line_info_rec_size;
 	if (rec_size < MIN_BPF_LINEINFO_SIZE ||
@@ -6953,8 +8963,11 @@
 	struct btf *btf;
 	int err;
 
-	if (!attr->func_info_cnt && !attr->line_info_cnt)
+	if (!attr->func_info_cnt && !attr->line_info_cnt) {
+		if (check_abnormal_return(env))
+			return -EINVAL;
 		return 0;
+	}
 
 	btf = btf_get_by_fd(attr->prog_btf_fd);
 	if (IS_ERR(btf))
@@ -6979,7 +8992,11 @@
 	return old->umin_value <= cur->umin_value &&
 	       old->umax_value >= cur->umax_value &&
 	       old->smin_value <= cur->smin_value &&
-	       old->smax_value >= cur->smax_value;
+	       old->smax_value >= cur->smax_value &&
+	       old->u32_min_value <= cur->u32_min_value &&
+	       old->u32_max_value >= cur->u32_max_value &&
+	       old->s32_min_value <= cur->s32_min_value &&
+	       old->s32_max_value >= cur->s32_max_value;
 }
 
 /* If in the old state two registers had the same id, then they need to have
@@ -7263,7 +9280,7 @@
 		if (old->stack[spi].slot_type[i % BPF_REG_SIZE] !=
 		    cur->stack[spi].slot_type[i % BPF_REG_SIZE])
 			/* Ex: old explored (safe) state has STACK_SPILL in
-			 * this stack slot, but current has has STACK_MISC ->
+			 * this stack slot, but current has STACK_MISC ->
 			 * this verifier states are not equivalent,
 			 * return false to continue verification of this path
 			 */
@@ -7644,7 +9661,7 @@
 	if (env->max_states_per_insn < states_cnt)
 		env->max_states_per_insn = states_cnt;
 
-	if (!env->allow_ptr_leaks && states_cnt > BPF_COMPLEXITY_LIMIT_STATES)
+	if (!env->bpf_capable && states_cnt > BPF_COMPLEXITY_LIMIT_STATES)
 		return push_jmp_history(env, cur);
 
 	if (!add_new_state)
@@ -7730,6 +9747,8 @@
 	case PTR_TO_TCP_SOCK:
 	case PTR_TO_TCP_SOCK_OR_NULL:
 	case PTR_TO_XDP_SOCK:
+	case PTR_TO_BTF_ID:
+	case PTR_TO_BTF_ID_OR_NULL:
 		return false;
 	default:
 		return true;
@@ -7756,32 +9775,14 @@
 
 static int do_check(struct bpf_verifier_env *env)
 {
-	struct bpf_verifier_state *state;
+	bool pop_log = !(env->log.level & BPF_LOG_LEVEL2);
+	struct bpf_verifier_state *state = env->cur_state;
 	struct bpf_insn *insns = env->prog->insnsi;
 	struct bpf_reg_state *regs;
 	int insn_cnt = env->prog->len;
 	bool do_print_state = false;
 	int prev_insn_idx = -1;
 
-	env->prev_linfo = NULL;
-
-	state = kzalloc(sizeof(struct bpf_verifier_state), GFP_KERNEL);
-	if (!state)
-		return -ENOMEM;
-	state->curframe = 0;
-	state->speculative = false;
-	state->branches = 1;
-	state->frame[0] = kzalloc(sizeof(struct bpf_func_state), GFP_KERNEL);
-	if (!state->frame[0]) {
-		kfree(state);
-		return -ENOMEM;
-	}
-	env->cur_state = state;
-	init_func_state(env, state->frame[0],
-			BPF_MAIN_FUNC /* callsite */,
-			0 /* frameno */,
-			0 /* subprogno, zero == main subprog */);
-
 	for (;;) {
 		struct bpf_insn *insn;
 		u8 class;
@@ -8045,28 +10046,13 @@
 				if (err)
 					return err;
 
-				/* eBPF calling convetion is such that R0 is used
-				 * to return the value from eBPF program.
-				 * Make sure that it's readable at this time
-				 * of bpf_exit, which means that program wrote
-				 * something into it earlier
-				 */
-				err = check_reg_arg(env, BPF_REG_0, SRC_OP);
-				if (err)
-					return err;
-
-				if (is_pointer_value(env, BPF_REG_0)) {
-					verbose(env, "R0 leaks addr as return value\n");
-					return -EACCES;
-				}
-
 				err = check_return_code(env);
 				if (err)
 					return err;
 process_bpf_exit:
 				update_branch_counts(env, env->cur_state);
 				err = pop_stack(env, &prev_insn_idx,
-						&env->insn_idx);
+						&env->insn_idx, pop_log);
 				if (err < 0) {
 					if (err != -ENOENT)
 						return err;
@@ -8107,7 +10093,93 @@
 		env->insn_idx++;
 	}
 
-	env->prog->aux->stack_depth = env->subprog_info[0].stack_depth;
+	return 0;
+}
+
+/* replace pseudo btf_id with kernel symbol address */
+static int check_pseudo_btf_id(struct bpf_verifier_env *env,
+			       struct bpf_insn *insn,
+			       struct bpf_insn_aux_data *aux)
+{
+	const struct btf_var_secinfo *vsi;
+	const struct btf_type *datasec;
+	const struct btf_type *t;
+	const char *sym_name;
+	bool percpu = false;
+	u32 type, id = insn->imm;
+	s32 datasec_id;
+	u64 addr;
+	int i;
+
+	if (!btf_vmlinux) {
+		verbose(env, "kernel is missing BTF, make sure CONFIG_DEBUG_INFO_BTF=y is specified in Kconfig.\n");
+		return -EINVAL;
+	}
+
+	if (insn[1].imm != 0) {
+		verbose(env, "reserved field (insn[1].imm) is used in pseudo_btf_id ldimm64 insn.\n");
+		return -EINVAL;
+	}
+
+	t = btf_type_by_id(btf_vmlinux, id);
+	if (!t) {
+		verbose(env, "ldimm64 insn specifies invalid btf_id %d.\n", id);
+		return -ENOENT;
+	}
+
+	if (!btf_type_is_var(t)) {
+		verbose(env, "pseudo btf_id %d in ldimm64 isn't KIND_VAR.\n",
+			id);
+		return -EINVAL;
+	}
+
+	sym_name = btf_name_by_offset(btf_vmlinux, t->name_off);
+	addr = kallsyms_lookup_name(sym_name);
+	if (!addr) {
+		verbose(env, "ldimm64 failed to find the address for kernel symbol '%s'.\n",
+			sym_name);
+		return -ENOENT;
+	}
+
+	datasec_id = btf_find_by_name_kind(btf_vmlinux, ".data..percpu",
+					   BTF_KIND_DATASEC);
+	if (datasec_id > 0) {
+		datasec = btf_type_by_id(btf_vmlinux, datasec_id);
+		for_each_vsi(i, datasec, vsi) {
+			if (vsi->type == id) {
+				percpu = true;
+				break;
+			}
+		}
+	}
+
+	insn[0].imm = (u32)addr;
+	insn[1].imm = addr >> 32;
+
+	type = t->type;
+	t = btf_type_skip_modifiers(btf_vmlinux, type, NULL);
+	if (percpu) {
+		aux->btf_var.reg_type = PTR_TO_PERCPU_BTF_ID;
+		aux->btf_var.btf_id = type;
+	} else if (!btf_type_is_struct(t)) {
+		const struct btf_type *ret;
+		const char *tname;
+		u32 tsize;
+
+		/* resolve the type size of ksym. */
+		ret = btf_resolve_size(btf_vmlinux, t, &tsize);
+		if (IS_ERR(ret)) {
+			tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+			verbose(env, "ldimm64 unable to resolve the size of type '%s': %ld\n",
+				tname, PTR_ERR(ret));
+			return -EINVAL;
+		}
+		aux->btf_var.reg_type = PTR_TO_MEM;
+		aux->btf_var.mem_size = tsize;
+	} else {
+		aux->btf_var.reg_type = PTR_TO_BTF_ID;
+		aux->btf_var.btf_id = type;
+	}
 	return 0;
 }
 
@@ -8132,30 +10204,53 @@
 	}
 }
 
+static bool is_preallocated_map(struct bpf_map *map)
+{
+	if (!check_map_prealloc(map))
+		return false;
+	if (map->inner_map_meta && !check_map_prealloc(map->inner_map_meta))
+		return false;
+	return true;
+}
+
 static int check_map_prog_compatibility(struct bpf_verifier_env *env,
 					struct bpf_map *map,
 					struct bpf_prog *prog)
 
 {
-	/* Make sure that BPF_PROG_TYPE_PERF_EVENT programs only use
-	 * preallocated hash maps, since doing memory allocation
-	 * in overflow_handler can crash depending on where nmi got
-	 * triggered.
+	enum bpf_prog_type prog_type = resolve_prog_type(prog);
+	/*
+	 * Validate that trace type programs use preallocated hash maps.
+	 *
+	 * For programs attached to PERF events this is mandatory as the
+	 * perf NMI can hit any arbitrary code sequence.
+	 *
+	 * All other trace types using preallocated hash maps are unsafe as
+	 * well because tracepoint or kprobes can be inside locked regions
+	 * of the memory allocator or at a place where a recursion into the
+	 * memory allocator would see inconsistent state.
+	 *
+	 * On RT enabled kernels run-time allocation of all trace type
+	 * programs is strictly prohibited due to lock type constraints. On
+	 * !RT kernels it is allowed for backwards compatibility reasons for
+	 * now, but warnings are emitted so developers are made aware of
+	 * the unsafety and can fix their programs before this is enforced.
 	 */
-	if (prog->type == BPF_PROG_TYPE_PERF_EVENT) {
-		if (!check_map_prealloc(map)) {
+	if (is_tracing_prog_type(prog_type) && !is_preallocated_map(map)) {
+		if (prog_type == BPF_PROG_TYPE_PERF_EVENT) {
 			verbose(env, "perf_event programs can only use preallocated hash map\n");
 			return -EINVAL;
 		}
-		if (map->inner_map_meta &&
-		    !check_map_prealloc(map->inner_map_meta)) {
-			verbose(env, "perf_event programs can only use preallocated inner hash map\n");
+		if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			verbose(env, "trace type programs can only use preallocated hash map\n");
 			return -EINVAL;
 		}
+		WARN_ONCE(1, "trace type BPF program uses run-time allocation\n");
+		verbose(env, "trace type programs with run-time allocated hash maps are unsafe. Switch to preallocated hash maps.\n");
 	}
 
-	if ((is_tracing_prog_type(prog->type) ||
-	     prog->type == BPF_PROG_TYPE_SOCKET_FILTER) &&
+	if ((is_tracing_prog_type(prog_type) ||
+	     prog_type == BPF_PROG_TYPE_SOCKET_FILTER) &&
 	    map_value_has_spin_lock(map)) {
 		verbose(env, "tracing progs cannot use bpf_spin_lock yet\n");
 		return -EINVAL;
@@ -8167,6 +10262,28 @@
 		return -EINVAL;
 	}
 
+	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		verbose(env, "bpf_struct_ops map cannot be used in prog\n");
+		return -EINVAL;
+	}
+
+	if (prog->aux->sleepable)
+		switch (map->map_type) {
+		case BPF_MAP_TYPE_HASH:
+		case BPF_MAP_TYPE_LRU_HASH:
+		case BPF_MAP_TYPE_ARRAY:
+			if (!is_preallocated_map(map)) {
+				verbose(env,
+					"Sleepable programs can only use preallocated hash maps\n");
+				return -EINVAL;
+			}
+			break;
+		default:
+			verbose(env,
+				"Sleepable programs can only use array and hash maps\n");
+			return -EINVAL;
+		}
+
 	return 0;
 }
 
@@ -8176,10 +10293,14 @@
 		map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
 }
 
-/* look for pseudo eBPF instructions that access map FDs and
- * replace them with actual map pointers
+/* find and rewrite pseudo imm in ld_imm64 instructions:
+ *
+ * 1. if it accesses map FD, replace it with actual map pointer.
+ * 2. if it accesses btf_id of a VAR, replace it with pointer to the var.
+ *
+ * NOTE: btf_vmlinux is required for converting pseudo btf_id.
  */
-static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
+static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
 {
 	struct bpf_insn *insn = env->prog->insnsi;
 	int insn_cnt = env->prog->len;
@@ -8220,6 +10341,14 @@
 				/* valid generic load 64-bit imm */
 				goto next_insn;
 
+			if (insn[0].src_reg == BPF_PSEUDO_BTF_ID) {
+				aux = &env->insn_aux_data[i];
+				err = check_pseudo_btf_id(env, insn, aux);
+				if (err)
+					return err;
+				goto next_insn;
+			}
+
 			/* In final convert_pseudo_ld_imm64() step, this is
 			 * converted into regular 64-bit imm load insn.
 			 */
@@ -8298,17 +10427,13 @@
 			 * will be used by the valid program until it's unloaded
 			 * and all maps are released in free_used_maps()
 			 */
-			map = bpf_map_inc(map, false);
-			if (IS_ERR(map)) {
-				fdput(f);
-				return PTR_ERR(map);
-			}
+			bpf_map_inc(map);
 
 			aux->map_index = env->used_map_cnt;
 			env->used_maps[env->used_map_cnt++] = map;
 
 			if (bpf_map_is_cgroup_storage(map) &&
-			    bpf_cgroup_storage_assign(env->prog, map)) {
+			    bpf_cgroup_storage_assign(env->prog->aux, map)) {
 				verbose(env, "only one cgroup storage of each type is allowed\n");
 				fdput(f);
 				return -EBUSY;
@@ -8338,18 +10463,8 @@
 /* drop refcnt of maps used by the rejected program */
 static void release_maps(struct bpf_verifier_env *env)
 {
-	enum bpf_cgroup_storage_type stype;
-	int i;
-
-	for_each_cgroup_storage_type(stype) {
-		if (!env->prog->aux->cgroup_storage[stype])
-			continue;
-		bpf_cgroup_storage_release(env->prog,
-			env->prog->aux->cgroup_storage[stype]);
-	}
-
-	for (i = 0; i < env->used_map_cnt; i++)
-		bpf_map_put(env->used_maps[i]);
+	__bpf_free_used_maps(env->prog->aux, env->used_maps,
+			     env->used_map_cnt);
 }
 
 /* convert pseudo BPF_LD_IMM64 into generic BPF_LD_IMM64 */
@@ -8374,7 +10489,7 @@
 {
 	struct bpf_insn_aux_data *old_data = env->insn_aux_data;
 	struct bpf_insn *insn = new_prog->insnsi;
-	bool old_seen = old_data[off].seen;
+	u32 old_seen = old_data[off].seen;
 	u32 prog_len;
 	int i;
 
@@ -8414,6 +10529,20 @@
 	}
 }
 
+static void adjust_poke_descs(struct bpf_prog *prog, u32 off, u32 len)
+{
+	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
+	int i, sz = prog->aux->size_poke_tab;
+	struct bpf_jit_poke_descriptor *desc;
+
+	for (i = 0; i < sz; i++) {
+		desc = &tab[i];
+		if (desc->insn_idx <= off)
+			continue;
+		desc->insn_idx += len - 1;
+	}
+}
+
 static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
 					    const struct bpf_insn *patch, u32 len)
 {
@@ -8438,6 +10567,7 @@
 	}
 	adjust_insn_aux_data(env, new_data, new_prog, off, len);
 	adjust_subprog_starts(env, off, len);
+	adjust_poke_descs(new_prog, off, len);
 	return new_prog;
 }
 
@@ -8880,6 +11010,16 @@
 		case PTR_TO_XDP_SOCK:
 			convert_ctx_access = bpf_xdp_sock_convert_ctx_access;
 			break;
+		case PTR_TO_BTF_ID:
+			if (type == BPF_READ) {
+				insn->code = BPF_LDX | BPF_PROBE_MEM |
+					BPF_SIZE((insn)->code);
+				env->prog->aux->num_exentries++;
+			} else if (resolve_prog_type(env->prog) != BPF_PROG_TYPE_STRUCT_OPS) {
+				verbose(env, "Writes through BTF pointers are not allowed\n");
+				return -EINVAL;
+			}
+			continue;
 		default:
 			continue;
 		}
@@ -8964,9 +11104,10 @@
 {
 	struct bpf_prog *prog = env->prog, **func, *tmp;
 	int i, j, subprog_start, subprog_end = 0, len, subprog;
+	struct bpf_map *map_ptr;
 	struct bpf_insn *insn;
 	void *old_bpf_func;
-	int err;
+	int err, num_exentries;
 
 	if (env->subprog_cnt <= 1)
 		return 0;
@@ -9027,9 +11168,20 @@
 			goto out_free;
 		func[i]->is_func = 1;
 		func[i]->aux->func_idx = i;
-		/* the btf and func_info will be freed only at prog->aux */
+		/* Below members will be freed only at prog->aux */
 		func[i]->aux->btf = prog->aux->btf;
 		func[i]->aux->func_info = prog->aux->func_info;
+		func[i]->aux->poke_tab = prog->aux->poke_tab;
+		func[i]->aux->size_poke_tab = prog->aux->size_poke_tab;
+
+		for (j = 0; j < prog->aux->size_poke_tab; j++) {
+			struct bpf_jit_poke_descriptor *poke;
+
+			poke = &prog->aux->poke_tab[j];
+			if (poke->insn_idx < subprog_end &&
+			    poke->insn_idx >= subprog_start)
+				poke->aux = func[i]->aux;
+		}
 
 		/* Use bpf_prog_F_tag to indicate functions in stack traces.
 		 * Long term would need debug info to populate names
@@ -9041,6 +11193,15 @@
 		func[i]->aux->nr_linfo = prog->aux->nr_linfo;
 		func[i]->aux->jited_linfo = prog->aux->jited_linfo;
 		func[i]->aux->linfo_idx = env->subprog_info[i].linfo_idx;
+		num_exentries = 0;
+		insn = func[i]->insnsi;
+		for (j = 0; j < func[i]->len; j++, insn++) {
+			if (BPF_CLASS(insn->code) == BPF_LDX &&
+			    BPF_MODE(insn->code) == BPF_PROBE_MEM)
+				num_exentries++;
+		}
+		func[i]->aux->num_exentries = num_exentries;
+		func[i]->aux->tail_call_reachable = env->subprog_info[i].tail_call_reachable;
 		func[i] = bpf_int_jit_compile(func[i]);
 		if (!func[i]->jited) {
 			err = -ENOTSUPP;
@@ -9048,6 +11209,7 @@
 		}
 		cond_resched();
 	}
+
 	/* at this point all bpf functions were successfully JITed
 	 * now populate all bpf_calls with correct addresses and
 	 * run last pass of JIT
@@ -9116,9 +11278,24 @@
 	bpf_prog_free_unused_jited_linfo(prog);
 	return 0;
 out_free:
-	for (i = 0; i < env->subprog_cnt; i++)
-		if (func[i])
-			bpf_jit_free(func[i]);
+	/* We failed JIT'ing, so at this point we need to unregister poke
+	 * descriptors from subprogs, so that kernel is not attempting to
+	 * patch it anymore as we're freeing the subprog JIT memory.
+	 */
+	for (i = 0; i < prog->aux->size_poke_tab; i++) {
+		map_ptr = prog->aux->poke_tab[i].tail_call.map;
+		map_ptr->ops->map_poke_untrack(map_ptr, prog->aux);
+	}
+	/* At this point we're guaranteed that poke descriptors are not
+	 * live anymore. We can just unlink its descriptor table as it's
+	 * released with the main prog.
+	 */
+	for (i = 0; i < env->subprog_cnt; i++) {
+		if (!func[i])
+			continue;
+		func[i]->aux->poke_tab = NULL;
+		bpf_jit_free(func[i]);
+	}
 	kfree(func);
 out_undo_insn:
 	/* cleanup main prog to be interpreted */
@@ -9152,6 +11329,13 @@
 			return err;
 	}
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
+	if (env->subprog_cnt > 1 && env->prog->aux->tail_call_reachable) {
+		/* When JIT fails the progs with bpf2bpf calls and tail_calls
+		 * have to be rejected, since interpreter doesn't support them yet.
+		 */
+		verbose(env, "tail_calls are not allowed in non-JITed programs with bpf-to-bpf calls\n");
+		return -EINVAL;
+	}
 	for (i = 0; i < prog->len; i++, insn++) {
 		if (insn->code != (BPF_JMP | BPF_CALL) ||
 		    insn->src_reg != BPF_PSEUDO_CALL)
@@ -9174,6 +11358,7 @@
 static int fixup_bpf_calls(struct bpf_verifier_env *env)
 {
 	struct bpf_prog *prog = env->prog;
+	bool expect_blinding = bpf_jit_blinding_enabled(prog);
 	struct bpf_insn *insn = prog->insnsi;
 	const struct bpf_func_proto *fn;
 	const int insn_cnt = prog->len;
@@ -9182,7 +11367,7 @@
 	struct bpf_insn insn_buf[16];
 	struct bpf_prog *new_prog;
 	struct bpf_map *map_ptr;
-	int i, cnt, delta = 0;
+	int i, ret, cnt, delta = 0;
 
 	for (i = 0; i < insn_cnt; i++, insn++) {
 		if (insn->code == (BPF_ALU64 | BPF_MOD | BPF_X) ||
@@ -9315,8 +11500,9 @@
 			 * the program array.
 			 */
 			prog->cb_access = 1;
-			env->prog->aux->stack_depth = MAX_BPF_STACK;
-			env->prog->aux->max_pkt_offset = MAX_PACKET_OFF;
+			if (!allow_tail_call_in_subprogs(env))
+				prog->aux->stack_depth = MAX_BPF_STACK;
+			prog->aux->max_pkt_offset = MAX_PACKET_OFF;
 
 			/* mark bpf_tail_call as different opcode to avoid
 			 * conditional branch in the interpeter for every normal
@@ -9327,6 +11513,28 @@
 			insn->code = BPF_JMP | BPF_TAIL_CALL;
 
 			aux = &env->insn_aux_data[i + delta];
+			if (env->bpf_capable && !expect_blinding &&
+			    prog->jit_requested &&
+			    !bpf_map_key_poisoned(aux) &&
+			    !bpf_map_ptr_poisoned(aux) &&
+			    !bpf_map_ptr_unpriv(aux)) {
+				struct bpf_jit_poke_descriptor desc = {
+					.reason = BPF_POKE_REASON_TAIL_CALL,
+					.tail_call.map = BPF_MAP_PTR(aux->map_ptr_state),
+					.tail_call.key = bpf_map_key_immediate(aux),
+					.insn_idx = i + delta,
+				};
+
+				ret = bpf_jit_add_poke_descriptor(prog, &desc);
+				if (ret < 0) {
+					verbose(env, "adding tail call poke descriptor failed\n");
+					return ret;
+				}
+
+				insn->imm = ret + 1;
+				continue;
+			}
+
 			if (!bpf_map_ptr_unpriv(aux))
 				continue;
 
@@ -9341,7 +11549,7 @@
 				return -EINVAL;
 			}
 
-			map_ptr = BPF_MAP_PTR(aux->map_state);
+			map_ptr = BPF_MAP_PTR(aux->map_ptr_state);
 			insn_buf[0] = BPF_JMP_IMM(BPF_JGE, BPF_REG_3,
 						  map_ptr->max_entries, 2);
 			insn_buf[1] = BPF_ALU32_IMM(BPF_AND, BPF_REG_3,
@@ -9375,12 +11583,14 @@
 			if (bpf_map_ptr_poisoned(aux))
 				goto patch_call_imm;
 
-			map_ptr = BPF_MAP_PTR(aux->map_state);
+			map_ptr = BPF_MAP_PTR(aux->map_ptr_state);
 			ops = map_ptr->ops;
 			if (insn->imm == BPF_FUNC_map_lookup_elem &&
 			    ops->map_gen_lookup) {
 				cnt = ops->map_gen_lookup(map_ptr, insn_buf);
-				if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf)) {
+				if (cnt == -EOPNOTSUPP)
+					goto patch_map_ops_generic;
+				if (cnt <= 0 || cnt >= ARRAY_SIZE(insn_buf)) {
 					verbose(env, "bpf verifier is misconfigured\n");
 					return -EINVAL;
 				}
@@ -9410,7 +11620,7 @@
 				     (int (*)(struct bpf_map *map, void *value))NULL));
 			BUILD_BUG_ON(!__same_type(ops->map_peek_elem,
 				     (int (*)(struct bpf_map *map, void *value))NULL));
-
+patch_map_ops_generic:
 			switch (insn->imm) {
 			case BPF_FUNC_map_lookup_elem:
 				insn->imm = BPF_CAST_CALL(ops->map_lookup_elem) -
@@ -9441,6 +11651,30 @@
 			goto patch_call_imm;
 		}
 
+		if (prog->jit_requested && BITS_PER_LONG == 64 &&
+		    insn->imm == BPF_FUNC_jiffies64) {
+			struct bpf_insn ld_jiffies_addr[2] = {
+				BPF_LD_IMM64(BPF_REG_0,
+					     (unsigned long)&jiffies),
+			};
+
+			insn_buf[0] = ld_jiffies_addr[0];
+			insn_buf[1] = ld_jiffies_addr[1];
+			insn_buf[2] = BPF_LDX_MEM(BPF_DW, BPF_REG_0,
+						  BPF_REG_0, 0);
+			cnt = 3;
+
+			new_prog = bpf_patch_insn_data(env, i + delta, insn_buf,
+						       cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
 patch_call_imm:
 		fn = env->ops->get_func_proto(insn->imm, env->prog);
 		/* all functions that have prototype and verifier allowed
@@ -9455,6 +11689,23 @@
 		insn->imm = fn->func - __bpf_call_base;
 	}
 
+	/* Since poke tab is now finalized, publish aux to tracker. */
+	for (i = 0; i < prog->aux->size_poke_tab; i++) {
+		map_ptr = prog->aux->poke_tab[i].tail_call.map;
+		if (!map_ptr->ops->map_poke_track ||
+		    !map_ptr->ops->map_poke_untrack ||
+		    !map_ptr->ops->map_poke_run) {
+			verbose(env, "bpf verifier is misconfigured\n");
+			return -EINVAL;
+		}
+
+		ret = map_ptr->ops->map_poke_track(map_ptr, prog->aux);
+		if (ret < 0) {
+			verbose(env, "tracking tail call prog failed\n");
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -9470,6 +11721,7 @@
 		kfree(sl);
 		sl = sln;
 	}
+	env->free_list = NULL;
 
 	if (!env->explored_states)
 		return;
@@ -9483,11 +11735,136 @@
 			kfree(sl);
 			sl = sln;
 		}
+		env->explored_states[i] = NULL;
+	}
+}
+
+static int do_check_common(struct bpf_verifier_env *env, int subprog)
+{
+	bool pop_log = !(env->log.level & BPF_LOG_LEVEL2);
+	struct bpf_verifier_state *state;
+	struct bpf_reg_state *regs;
+	int ret, i;
+
+	env->prev_linfo = NULL;
+	env->pass_cnt++;
+
+	state = kzalloc(sizeof(struct bpf_verifier_state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+	state->curframe = 0;
+	state->speculative = false;
+	state->branches = 1;
+	state->frame[0] = kzalloc(sizeof(struct bpf_func_state), GFP_KERNEL);
+	if (!state->frame[0]) {
+		kfree(state);
+		return -ENOMEM;
+	}
+	env->cur_state = state;
+	init_func_state(env, state->frame[0],
+			BPF_MAIN_FUNC /* callsite */,
+			0 /* frameno */,
+			subprog);
+
+	regs = state->frame[state->curframe]->regs;
+	if (subprog || env->prog->type == BPF_PROG_TYPE_EXT) {
+		ret = btf_prepare_func_args(env, subprog, regs);
+		if (ret)
+			goto out;
+		for (i = BPF_REG_1; i <= BPF_REG_5; i++) {
+			if (regs[i].type == PTR_TO_CTX)
+				mark_reg_known_zero(env, regs, i);
+			else if (regs[i].type == SCALAR_VALUE)
+				mark_reg_unknown(env, regs, i);
+		}
+	} else {
+		/* 1st arg to a function */
+		regs[BPF_REG_1].type = PTR_TO_CTX;
+		mark_reg_known_zero(env, regs, BPF_REG_1);
+		ret = btf_check_func_arg_match(env, subprog, regs);
+		if (ret == -EFAULT)
+			/* unlikely verifier bug. abort.
+			 * ret == 0 and ret < 0 are sadly acceptable for
+			 * main() function due to backward compatibility.
+			 * Like socket filter program may be written as:
+			 * int bpf_prog(struct pt_regs *ctx)
+			 * and never dereference that ctx in the program.
+			 * 'struct pt_regs' is a type mismatch for socket
+			 * filter that should be using 'struct __sk_buff'.
+			 */
+			goto out;
 	}
 
-	kvfree(env->explored_states);
+	ret = do_check(env);
+out:
+	/* check for NULL is necessary, since cur_state can be freed inside
+	 * do_check() under memory pressure.
+	 */
+	if (env->cur_state) {
+		free_verifier_state(env->cur_state, true);
+		env->cur_state = NULL;
+	}
+	while (!pop_stack(env, NULL, NULL, false));
+	if (!ret && pop_log)
+		bpf_vlog_reset(&env->log, 0);
+	free_states(env);
+	return ret;
 }
 
+/* Verify all global functions in a BPF program one by one based on their BTF.
+ * All global functions must pass verification. Otherwise the whole program is rejected.
+ * Consider:
+ * int bar(int);
+ * int foo(int f)
+ * {
+ *    return bar(f);
+ * }
+ * int bar(int b)
+ * {
+ *    ...
+ * }
+ * foo() will be verified first for R1=any_scalar_value. During verification it
+ * will be assumed that bar() already verified successfully and call to bar()
+ * from foo() will be checked for type match only. Later bar() will be verified
+ * independently to check that it's safe for R1=any_scalar_value.
+ */
+static int do_check_subprogs(struct bpf_verifier_env *env)
+{
+	struct bpf_prog_aux *aux = env->prog->aux;
+	int i, ret;
+
+	if (!aux->func_info)
+		return 0;
+
+	for (i = 1; i < env->subprog_cnt; i++) {
+		if (aux->func_info_aux[i].linkage != BTF_FUNC_GLOBAL)
+			continue;
+		env->insn_idx = env->subprog_info[i].start;
+		WARN_ON_ONCE(env->insn_idx == 0);
+		ret = do_check_common(env, i);
+		if (ret) {
+			return ret;
+		} else if (env->log.level & BPF_LOG_LEVEL) {
+			verbose(env,
+				"Func#%d is safe for any args that match its prototype\n",
+				i);
+		}
+	}
+	return 0;
+}
+
+static int do_check_main(struct bpf_verifier_env *env)
+{
+	int ret;
+
+	env->insn_idx = 0;
+	ret = do_check_common(env, 0);
+	if (!ret)
+		env->prog->aux->stack_depth = env->subprog_info[0].stack_depth;
+	return ret;
+}
+
+
 static void print_verification_stats(struct bpf_verifier_env *env)
 {
 	int i;
@@ -9512,6 +11889,419 @@
 		env->peak_states, env->longest_mark_read_walk);
 }
 
+static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
+{
+	const struct btf_type *t, *func_proto;
+	const struct bpf_struct_ops *st_ops;
+	const struct btf_member *member;
+	struct bpf_prog *prog = env->prog;
+	u32 btf_id, member_idx;
+	const char *mname;
+
+	if (!prog->gpl_compatible) {
+		verbose(env, "struct ops programs must have a GPL compatible license\n");
+		return -EINVAL;
+	}
+
+	btf_id = prog->aux->attach_btf_id;
+	st_ops = bpf_struct_ops_find(btf_id);
+	if (!st_ops) {
+		verbose(env, "attach_btf_id %u is not a supported struct\n",
+			btf_id);
+		return -ENOTSUPP;
+	}
+
+	t = st_ops->type;
+	member_idx = prog->expected_attach_type;
+	if (member_idx >= btf_type_vlen(t)) {
+		verbose(env, "attach to invalid member idx %u of struct %s\n",
+			member_idx, st_ops->name);
+		return -EINVAL;
+	}
+
+	member = &btf_type_member(t)[member_idx];
+	mname = btf_name_by_offset(btf_vmlinux, member->name_off);
+	func_proto = btf_type_resolve_func_ptr(btf_vmlinux, member->type,
+					       NULL);
+	if (!func_proto) {
+		verbose(env, "attach to invalid member %s(@idx %u) of struct %s\n",
+			mname, member_idx, st_ops->name);
+		return -EINVAL;
+	}
+
+	if (st_ops->check_member) {
+		int err = st_ops->check_member(t, member);
+
+		if (err) {
+			verbose(env, "attach to unsupported member %s of struct %s\n",
+				mname, st_ops->name);
+			return err;
+		}
+	}
+
+	prog->aux->attach_func_proto = func_proto;
+	prog->aux->attach_func_name = mname;
+	env->ops = st_ops->verifier_ops;
+
+	return 0;
+}
+#define SECURITY_PREFIX "security_"
+
+static int check_attach_modify_return(unsigned long addr, const char *func_name)
+{
+	if (within_error_injection_list(addr) ||
+	    !strncmp(SECURITY_PREFIX, func_name, sizeof(SECURITY_PREFIX) - 1))
+		return 0;
+
+	return -EINVAL;
+}
+
+/* non exhaustive list of sleepable bpf_lsm_*() functions */
+BTF_SET_START(btf_sleepable_lsm_hooks)
+#ifdef CONFIG_BPF_LSM
+BTF_ID(func, bpf_lsm_bprm_committed_creds)
+#else
+BTF_ID_UNUSED
+#endif
+BTF_SET_END(btf_sleepable_lsm_hooks)
+
+static int check_sleepable_lsm_hook(u32 btf_id)
+{
+	return btf_id_set_contains(&btf_sleepable_lsm_hooks, btf_id);
+}
+
+/* list of non-sleepable functions that are otherwise on
+ * ALLOW_ERROR_INJECTION list
+ */
+BTF_SET_START(btf_non_sleepable_error_inject)
+/* Three functions below can be called from sleepable and non-sleepable context.
+ * Assume non-sleepable from bpf safety point of view.
+ */
+BTF_ID(func, __add_to_page_cache_locked)
+BTF_ID(func, should_fail_alloc_page)
+BTF_ID(func, should_failslab)
+BTF_SET_END(btf_non_sleepable_error_inject)
+
+static int check_non_sleepable_error_inject(u32 btf_id)
+{
+	return btf_id_set_contains(&btf_non_sleepable_error_inject, btf_id);
+}
+
+int bpf_check_attach_target(struct bpf_verifier_log *log,
+			    const struct bpf_prog *prog,
+			    const struct bpf_prog *tgt_prog,
+			    u32 btf_id,
+			    struct bpf_attach_target_info *tgt_info)
+{
+	bool prog_extension = prog->type == BPF_PROG_TYPE_EXT;
+	const char prefix[] = "btf_trace_";
+	int ret = 0, subprog = -1, i;
+	const struct btf_type *t;
+	bool conservative = true;
+	const char *tname;
+	struct btf *btf;
+	long addr = 0;
+
+	if (!btf_id) {
+		bpf_log(log, "Tracing programs must provide btf_id\n");
+		return -EINVAL;
+	}
+	btf = tgt_prog ? tgt_prog->aux->btf : btf_vmlinux;
+	if (!btf) {
+		bpf_log(log,
+			"FENTRY/FEXIT program can only be attached to another program annotated with BTF\n");
+		return -EINVAL;
+	}
+	t = btf_type_by_id(btf, btf_id);
+	if (!t) {
+		bpf_log(log, "attach_btf_id %u is invalid\n", btf_id);
+		return -EINVAL;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+	if (!tname) {
+		bpf_log(log, "attach_btf_id %u doesn't have a name\n", btf_id);
+		return -EINVAL;
+	}
+	if (tgt_prog) {
+		struct bpf_prog_aux *aux = tgt_prog->aux;
+
+		for (i = 0; i < aux->func_info_cnt; i++)
+			if (aux->func_info[i].type_id == btf_id) {
+				subprog = i;
+				break;
+			}
+		if (subprog == -1) {
+			bpf_log(log, "Subprog %s doesn't exist\n", tname);
+			return -EINVAL;
+		}
+		conservative = aux->func_info_aux[subprog].unreliable;
+		if (prog_extension) {
+			if (conservative) {
+				bpf_log(log,
+					"Cannot replace static functions\n");
+				return -EINVAL;
+			}
+			if (!prog->jit_requested) {
+				bpf_log(log,
+					"Extension programs should be JITed\n");
+				return -EINVAL;
+			}
+		}
+		if (!tgt_prog->jited) {
+			bpf_log(log, "Can attach to only JITed progs\n");
+			return -EINVAL;
+		}
+		if (tgt_prog->type == prog->type) {
+			/* Cannot fentry/fexit another fentry/fexit program.
+			 * Cannot attach program extension to another extension.
+			 * It's ok to attach fentry/fexit to extension program.
+			 */
+			bpf_log(log, "Cannot recursively attach\n");
+			return -EINVAL;
+		}
+		if (tgt_prog->type == BPF_PROG_TYPE_TRACING &&
+		    prog_extension &&
+		    (tgt_prog->expected_attach_type == BPF_TRACE_FENTRY ||
+		     tgt_prog->expected_attach_type == BPF_TRACE_FEXIT)) {
+			/* Program extensions can extend all program types
+			 * except fentry/fexit. The reason is the following.
+			 * The fentry/fexit programs are used for performance
+			 * analysis, stats and can be attached to any program
+			 * type except themselves. When extension program is
+			 * replacing XDP function it is necessary to allow
+			 * performance analysis of all functions. Both original
+			 * XDP program and its program extension. Hence
+			 * attaching fentry/fexit to BPF_PROG_TYPE_EXT is
+			 * allowed. If extending of fentry/fexit was allowed it
+			 * would be possible to create long call chain
+			 * fentry->extension->fentry->extension beyond
+			 * reasonable stack size. Hence extending fentry is not
+			 * allowed.
+			 */
+			bpf_log(log, "Cannot extend fentry/fexit\n");
+			return -EINVAL;
+		}
+	} else {
+		if (prog_extension) {
+			bpf_log(log, "Cannot replace kernel functions\n");
+			return -EINVAL;
+		}
+	}
+
+	switch (prog->expected_attach_type) {
+	case BPF_TRACE_RAW_TP:
+		if (tgt_prog) {
+			bpf_log(log,
+				"Only FENTRY/FEXIT progs are attachable to another BPF prog\n");
+			return -EINVAL;
+		}
+		if (!btf_type_is_typedef(t)) {
+			bpf_log(log, "attach_btf_id %u is not a typedef\n",
+				btf_id);
+			return -EINVAL;
+		}
+		if (strncmp(prefix, tname, sizeof(prefix) - 1)) {
+			bpf_log(log, "attach_btf_id %u points to wrong type name %s\n",
+				btf_id, tname);
+			return -EINVAL;
+		}
+		tname += sizeof(prefix) - 1;
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_ptr(t))
+			/* should never happen in valid vmlinux build */
+			return -EINVAL;
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_func_proto(t))
+			/* should never happen in valid vmlinux build */
+			return -EINVAL;
+
+		break;
+	case BPF_TRACE_ITER:
+		if (!btf_type_is_func(t)) {
+			bpf_log(log, "attach_btf_id %u is not a function\n",
+				btf_id);
+			return -EINVAL;
+		}
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_func_proto(t))
+			return -EINVAL;
+		ret = btf_distill_func_proto(log, btf, t, tname, &tgt_info->fmodel);
+		if (ret)
+			return ret;
+		break;
+	default:
+		if (!prog_extension)
+			return -EINVAL;
+		fallthrough;
+	case BPF_MODIFY_RETURN:
+	case BPF_LSM_MAC:
+	case BPF_TRACE_FENTRY:
+	case BPF_TRACE_FEXIT:
+		if (!btf_type_is_func(t)) {
+			bpf_log(log, "attach_btf_id %u is not a function\n",
+				btf_id);
+			return -EINVAL;
+		}
+		if (prog_extension &&
+		    btf_check_type_match(log, prog, btf, t))
+			return -EINVAL;
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_func_proto(t))
+			return -EINVAL;
+
+		if ((prog->aux->saved_dst_prog_type || prog->aux->saved_dst_attach_type) &&
+		    (!tgt_prog || prog->aux->saved_dst_prog_type != tgt_prog->type ||
+		     prog->aux->saved_dst_attach_type != tgt_prog->expected_attach_type))
+			return -EINVAL;
+
+		if (tgt_prog && conservative)
+			t = NULL;
+
+		ret = btf_distill_func_proto(log, btf, t, tname, &tgt_info->fmodel);
+		if (ret < 0)
+			return ret;
+
+		if (tgt_prog) {
+			if (subprog == 0)
+				addr = (long) tgt_prog->bpf_func;
+			else
+				addr = (long) tgt_prog->aux->func[subprog]->bpf_func;
+		} else {
+			addr = kallsyms_lookup_name(tname);
+			if (!addr) {
+				bpf_log(log,
+					"The address of function %s cannot be found\n",
+					tname);
+				return -ENOENT;
+			}
+		}
+
+		if (prog->aux->sleepable) {
+			ret = -EINVAL;
+			switch (prog->type) {
+			case BPF_PROG_TYPE_TRACING:
+				/* fentry/fexit/fmod_ret progs can be sleepable only if they are
+				 * attached to ALLOW_ERROR_INJECTION and are not in denylist.
+				 */
+				if (!check_non_sleepable_error_inject(btf_id) &&
+				    within_error_injection_list(addr))
+					ret = 0;
+				break;
+			case BPF_PROG_TYPE_LSM:
+				/* LSM progs check that they are attached to bpf_lsm_*() funcs.
+				 * Only some of them are sleepable.
+				 */
+				if (check_sleepable_lsm_hook(btf_id))
+					ret = 0;
+				break;
+			default:
+				break;
+			}
+			if (ret) {
+				bpf_log(log, "%s is not sleepable\n", tname);
+				return ret;
+			}
+		} else if (prog->expected_attach_type == BPF_MODIFY_RETURN) {
+			if (tgt_prog) {
+				bpf_log(log, "can't modify return codes of BPF programs\n");
+				return -EINVAL;
+			}
+			ret = check_attach_modify_return(addr, tname);
+			if (ret) {
+				bpf_log(log, "%s() is not modifiable\n", tname);
+				return ret;
+			}
+		}
+
+		break;
+	}
+	tgt_info->tgt_addr = addr;
+	tgt_info->tgt_name = tname;
+	tgt_info->tgt_type = t;
+	return 0;
+}
+
+static int check_attach_btf_id(struct bpf_verifier_env *env)
+{
+	struct bpf_prog *prog = env->prog;
+	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
+	struct bpf_attach_target_info tgt_info = {};
+	u32 btf_id = prog->aux->attach_btf_id;
+	struct bpf_trampoline *tr;
+	int ret;
+	u64 key;
+
+	if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING &&
+	    prog->type != BPF_PROG_TYPE_LSM) {
+		verbose(env, "Only fentry/fexit/fmod_ret and lsm programs can be sleepable\n");
+		return -EINVAL;
+	}
+
+	if (prog->type == BPF_PROG_TYPE_STRUCT_OPS)
+		return check_struct_ops_btf_id(env);
+
+	if (prog->type != BPF_PROG_TYPE_TRACING &&
+	    prog->type != BPF_PROG_TYPE_LSM &&
+	    prog->type != BPF_PROG_TYPE_EXT)
+		return 0;
+
+	ret = bpf_check_attach_target(&env->log, prog, tgt_prog, btf_id, &tgt_info);
+	if (ret)
+		return ret;
+
+	if (tgt_prog && prog->type == BPF_PROG_TYPE_EXT) {
+		/* to make freplace equivalent to their targets, they need to
+		 * inherit env->ops and expected_attach_type for the rest of the
+		 * verification
+		 */
+		env->ops = bpf_verifier_ops[tgt_prog->type];
+		prog->expected_attach_type = tgt_prog->expected_attach_type;
+	}
+
+	/* store info about the attachment target that will be used later */
+	prog->aux->attach_func_proto = tgt_info.tgt_type;
+	prog->aux->attach_func_name = tgt_info.tgt_name;
+
+	if (tgt_prog) {
+		prog->aux->saved_dst_prog_type = tgt_prog->type;
+		prog->aux->saved_dst_attach_type = tgt_prog->expected_attach_type;
+	}
+
+	if (prog->expected_attach_type == BPF_TRACE_RAW_TP) {
+		prog->aux->attach_btf_trace = true;
+		return 0;
+	} else if (prog->expected_attach_type == BPF_TRACE_ITER) {
+		if (!bpf_iter_prog_supported(prog))
+			return -EINVAL;
+		return 0;
+	}
+
+	if (prog->type == BPF_PROG_TYPE_LSM) {
+		ret = bpf_lsm_verify_prog(&env->log, prog);
+		if (ret < 0)
+			return ret;
+	}
+
+	key = bpf_trampoline_compute_key(tgt_prog, btf_id);
+	tr = bpf_trampoline_get(key, &tgt_info);
+	if (!tr)
+		return -ENOMEM;
+
+	prog->aux->dst_trampoline = tr;
+	return 0;
+}
+
+struct btf *bpf_get_btf_vmlinux(void)
+{
+	if (!btf_vmlinux && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
+		mutex_lock(&bpf_verifier_lock);
+		if (!btf_vmlinux)
+			btf_vmlinux = btf_parse_vmlinux();
+		mutex_unlock(&bpf_verifier_lock);
+	}
+	return btf_vmlinux;
+}
+
 int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 	      union bpf_attr __user *uattr)
 {
@@ -9543,7 +12333,9 @@
 		env->insn_aux_data[i].orig_idx = i;
 	env->prog = *prog;
 	env->ops = bpf_verifier_ops[env->prog->type];
-	is_priv = capable(CAP_SYS_ADMIN);
+	is_priv = bpf_capable();
+
+	bpf_get_btf_vmlinux();
 
 	/* grab the mutex to protect few globals used by verifier */
 	if (!is_priv)
@@ -9557,11 +12349,18 @@
 		log->ubuf = (char __user *) (unsigned long) attr->log_buf;
 		log->len_total = attr->log_size;
 
-		ret = -EINVAL;
 		/* log attributes have to be sane */
-		if (log->len_total < 128 || log->len_total > UINT_MAX >> 2 ||
-		    !log->level || !log->ubuf || log->level & ~BPF_LOG_MASK)
+		if (!bpf_verifier_log_attr_valid(log)) {
+			ret = -EINVAL;
 			goto err_unlock;
+		}
+	}
+
+	if (IS_ERR(btf_vmlinux)) {
+		/* Either gcc or pahole or kernel are broken. */
+		verbose(env, "in-kernel BTF is malformed\n");
+		ret = PTR_ERR(btf_vmlinux);
+		goto skip_full_check;
 	}
 
 	env->strict_alignment = !!(attr->prog_flags & BPF_F_STRICT_ALIGNMENT);
@@ -9570,21 +12369,16 @@
 	if (attr->prog_flags & BPF_F_ANY_ALIGNMENT)
 		env->strict_alignment = false;
 
-	env->allow_ptr_leaks = is_priv;
+	env->allow_ptr_leaks = bpf_allow_ptr_leaks();
+	env->allow_uninit_stack = bpf_allow_uninit_stack();
+	env->allow_ptr_to_map_access = bpf_allow_ptr_to_map_access();
+	env->bypass_spec_v1 = bpf_bypass_spec_v1();
+	env->bypass_spec_v4 = bpf_bypass_spec_v4();
+	env->bpf_capable = bpf_capable();
 
 	if (is_priv)
 		env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;
 
-	ret = replace_map_fd_with_map_ptr(env);
-	if (ret < 0)
-		goto skip_full_check;
-
-	if (bpf_prog_is_dev_bound(env->prog->aux)) {
-		ret = bpf_prog_offload_verifier_prep(env->prog);
-		if (ret)
-			goto skip_full_check;
-	}
-
 	env->explored_states = kvcalloc(state_htab_size(env),
 				       sizeof(struct bpf_verifier_state_list *),
 				       GFP_USER);
@@ -9600,22 +12394,32 @@
 	if (ret < 0)
 		goto skip_full_check;
 
+	ret = check_attach_btf_id(env);
+	if (ret)
+		goto skip_full_check;
+
+	ret = resolve_pseudo_ldimm64(env);
+	if (ret < 0)
+		goto skip_full_check;
+
+	if (bpf_prog_is_dev_bound(env->prog->aux)) {
+		ret = bpf_prog_offload_verifier_prep(env->prog);
+		if (ret)
+			goto skip_full_check;
+	}
+
 	ret = check_cfg(env);
 	if (ret < 0)
 		goto skip_full_check;
 
-	ret = do_check(env);
-	if (env->cur_state) {
-		free_verifier_state(env->cur_state, true);
-		env->cur_state = NULL;
-	}
+	ret = do_check_subprogs(env);
+	ret = ret ?: do_check_main(env);
 
 	if (ret == 0 && bpf_prog_is_dev_bound(env->prog->aux))
 		ret = bpf_prog_offload_finalize(env);
 
 skip_full_check:
-	while (!pop_stack(env, NULL, NULL));
-	free_states(env);
+	kvfree(env->explored_states);
 
 	if (ret == 0)
 		ret = check_max_stack_depth(env);
@@ -9692,6 +12496,13 @@
 		 * them now. Otherwise free_used_maps() will release them.
 		 */
 		release_maps(env);
+
+	/* extension progs temporarily inherit the attach_type of their targets
+	   for verification purposes, so set it back to zero before returning
+	 */
+	if (env->prog->type == BPF_PROG_TYPE_EXT)
+		env->prog->expected_attach_type = 0;
+
 	*prog = env->prog;
 err_unlock:
 	if (!is_priv)
diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c
deleted file mode 100644
index 82a1ffe..0000000
--- a/kernel/bpf/xskmap.c
+++ /dev/null
@@ -1,319 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/* XSKMAP used for AF_XDP sockets
- * Copyright(c) 2018 Intel Corporation.
- */
-
-#include <linux/bpf.h>
-#include <linux/capability.h>
-#include <net/xdp_sock.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-
-struct xsk_map {
-	struct bpf_map map;
-	struct xdp_sock **xsk_map;
-	struct list_head __percpu *flush_list;
-	spinlock_t lock; /* Synchronize map updates */
-};
-
-int xsk_map_inc(struct xsk_map *map)
-{
-	struct bpf_map *m = &map->map;
-
-	m = bpf_map_inc(m, false);
-	return PTR_ERR_OR_ZERO(m);
-}
-
-void xsk_map_put(struct xsk_map *map)
-{
-	bpf_map_put(&map->map);
-}
-
-static struct xsk_map_node *xsk_map_node_alloc(struct xsk_map *map,
-					       struct xdp_sock **map_entry)
-{
-	struct xsk_map_node *node;
-	int err;
-
-	node = kzalloc(sizeof(*node), GFP_ATOMIC | __GFP_NOWARN);
-	if (!node)
-		return ERR_PTR(-ENOMEM);
-
-	err = xsk_map_inc(map);
-	if (err) {
-		kfree(node);
-		return ERR_PTR(err);
-	}
-
-	node->map = map;
-	node->map_entry = map_entry;
-	return node;
-}
-
-static void xsk_map_node_free(struct xsk_map_node *node)
-{
-	xsk_map_put(node->map);
-	kfree(node);
-}
-
-static void xsk_map_sock_add(struct xdp_sock *xs, struct xsk_map_node *node)
-{
-	spin_lock_bh(&xs->map_list_lock);
-	list_add_tail(&node->node, &xs->map_list);
-	spin_unlock_bh(&xs->map_list_lock);
-}
-
-static void xsk_map_sock_delete(struct xdp_sock *xs,
-				struct xdp_sock **map_entry)
-{
-	struct xsk_map_node *n, *tmp;
-
-	spin_lock_bh(&xs->map_list_lock);
-	list_for_each_entry_safe(n, tmp, &xs->map_list, node) {
-		if (map_entry == n->map_entry) {
-			list_del(&n->node);
-			xsk_map_node_free(n);
-		}
-	}
-	spin_unlock_bh(&xs->map_list_lock);
-}
-
-static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
-{
-	struct xsk_map *m;
-	int cpu, err;
-	u64 cost;
-
-	if (!capable(CAP_NET_ADMIN))
-		return ERR_PTR(-EPERM);
-
-	if (attr->max_entries == 0 || attr->key_size != 4 ||
-	    attr->value_size != 4 ||
-	    attr->map_flags & ~(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY))
-		return ERR_PTR(-EINVAL);
-
-	m = kzalloc(sizeof(*m), GFP_USER);
-	if (!m)
-		return ERR_PTR(-ENOMEM);
-
-	bpf_map_init_from_attr(&m->map, attr);
-	spin_lock_init(&m->lock);
-
-	cost = (u64)m->map.max_entries * sizeof(struct xdp_sock *);
-	cost += sizeof(struct list_head) * num_possible_cpus();
-
-	/* Notice returns -EPERM on if map size is larger than memlock limit */
-	err = bpf_map_charge_init(&m->map.memory, cost);
-	if (err)
-		goto free_m;
-
-	err = -ENOMEM;
-
-	m->flush_list = alloc_percpu(struct list_head);
-	if (!m->flush_list)
-		goto free_charge;
-
-	for_each_possible_cpu(cpu)
-		INIT_LIST_HEAD(per_cpu_ptr(m->flush_list, cpu));
-
-	m->xsk_map = bpf_map_area_alloc(m->map.max_entries *
-					sizeof(struct xdp_sock *),
-					m->map.numa_node);
-	if (!m->xsk_map)
-		goto free_percpu;
-	return &m->map;
-
-free_percpu:
-	free_percpu(m->flush_list);
-free_charge:
-	bpf_map_charge_finish(&m->map.memory);
-free_m:
-	kfree(m);
-	return ERR_PTR(err);
-}
-
-static void xsk_map_free(struct bpf_map *map)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-
-	bpf_clear_redirect_map(map);
-	synchronize_net();
-	free_percpu(m->flush_list);
-	bpf_map_area_free(m->xsk_map);
-	kfree(m);
-}
-
-static int xsk_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	u32 index = key ? *(u32 *)key : U32_MAX;
-	u32 *next = next_key;
-
-	if (index >= m->map.max_entries) {
-		*next = 0;
-		return 0;
-	}
-
-	if (index == m->map.max_entries - 1)
-		return -ENOENT;
-	*next = index + 1;
-	return 0;
-}
-
-struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map, u32 key)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	struct xdp_sock *xs;
-
-	if (key >= map->max_entries)
-		return NULL;
-
-	xs = READ_ONCE(m->xsk_map[key]);
-	return xs;
-}
-
-int __xsk_map_redirect(struct bpf_map *map, struct xdp_buff *xdp,
-		       struct xdp_sock *xs)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	struct list_head *flush_list = this_cpu_ptr(m->flush_list);
-	int err;
-
-	err = xsk_rcv(xs, xdp);
-	if (err)
-		return err;
-
-	if (!xs->flush_node.prev)
-		list_add(&xs->flush_node, flush_list);
-
-	return 0;
-}
-
-void __xsk_map_flush(struct bpf_map *map)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	struct list_head *flush_list = this_cpu_ptr(m->flush_list);
-	struct xdp_sock *xs, *tmp;
-
-	list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
-		xsk_flush(xs);
-		__list_del_clearprev(&xs->flush_node);
-	}
-}
-
-static void *xsk_map_lookup_elem(struct bpf_map *map, void *key)
-{
-	WARN_ON_ONCE(!rcu_read_lock_held());
-	return __xsk_map_lookup_elem(map, *(u32 *)key);
-}
-
-static void *xsk_map_lookup_elem_sys_only(struct bpf_map *map, void *key)
-{
-	return ERR_PTR(-EOPNOTSUPP);
-}
-
-static int xsk_map_update_elem(struct bpf_map *map, void *key, void *value,
-			       u64 map_flags)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	struct xdp_sock *xs, *old_xs, **map_entry;
-	u32 i = *(u32 *)key, fd = *(u32 *)value;
-	struct xsk_map_node *node;
-	struct socket *sock;
-	int err;
-
-	if (unlikely(map_flags > BPF_EXIST))
-		return -EINVAL;
-	if (unlikely(i >= m->map.max_entries))
-		return -E2BIG;
-
-	sock = sockfd_lookup(fd, &err);
-	if (!sock)
-		return err;
-
-	if (sock->sk->sk_family != PF_XDP) {
-		sockfd_put(sock);
-		return -EOPNOTSUPP;
-	}
-
-	xs = (struct xdp_sock *)sock->sk;
-
-	if (!xsk_is_setup_for_bpf_map(xs)) {
-		sockfd_put(sock);
-		return -EOPNOTSUPP;
-	}
-
-	map_entry = &m->xsk_map[i];
-	node = xsk_map_node_alloc(m, map_entry);
-	if (IS_ERR(node)) {
-		sockfd_put(sock);
-		return PTR_ERR(node);
-	}
-
-	spin_lock_bh(&m->lock);
-	old_xs = READ_ONCE(*map_entry);
-	if (old_xs == xs) {
-		err = 0;
-		goto out;
-	} else if (old_xs && map_flags == BPF_NOEXIST) {
-		err = -EEXIST;
-		goto out;
-	} else if (!old_xs && map_flags == BPF_EXIST) {
-		err = -ENOENT;
-		goto out;
-	}
-	xsk_map_sock_add(xs, node);
-	WRITE_ONCE(*map_entry, xs);
-	if (old_xs)
-		xsk_map_sock_delete(old_xs, map_entry);
-	spin_unlock_bh(&m->lock);
-	sockfd_put(sock);
-	return 0;
-
-out:
-	spin_unlock_bh(&m->lock);
-	sockfd_put(sock);
-	xsk_map_node_free(node);
-	return err;
-}
-
-static int xsk_map_delete_elem(struct bpf_map *map, void *key)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	struct xdp_sock *old_xs, **map_entry;
-	int k = *(u32 *)key;
-
-	if (k >= map->max_entries)
-		return -EINVAL;
-
-	spin_lock_bh(&m->lock);
-	map_entry = &m->xsk_map[k];
-	old_xs = xchg(map_entry, NULL);
-	if (old_xs)
-		xsk_map_sock_delete(old_xs, map_entry);
-	spin_unlock_bh(&m->lock);
-
-	return 0;
-}
-
-void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
-			     struct xdp_sock **map_entry)
-{
-	spin_lock_bh(&map->lock);
-	if (READ_ONCE(*map_entry) == xs) {
-		WRITE_ONCE(*map_entry, NULL);
-		xsk_map_sock_delete(xs, map_entry);
-	}
-	spin_unlock_bh(&map->lock);
-}
-
-const struct bpf_map_ops xsk_map_ops = {
-	.map_alloc = xsk_map_alloc,
-	.map_free = xsk_map_free,
-	.map_get_next_key = xsk_map_get_next_key,
-	.map_lookup_elem = xsk_map_lookup_elem,
-	.map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only,
-	.map_update_elem = xsk_map_update_elem,
-	.map_delete_elem = xsk_map_delete_elem,
-	.map_check_btf = map_check_no_btf,
-};
diff --git a/kernel/capability.c b/kernel/capability.c
index 1444f39..de7eac9 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -93,7 +93,7 @@
 		break;
 	case _LINUX_CAPABILITY_VERSION_2:
 		warn_deprecated_v2();
-		/* fall through - v3 is otherwise equivalent to v2. */
+		fallthrough;	/* v3 is otherwise equivalent to v2 */
 	case _LINUX_CAPABILITY_VERSION_3:
 		*tocopy = _LINUX_CAPABILITY_U32S_3;
 		break;
@@ -418,7 +418,7 @@
 /**
  * ns_capable_setid - Determine if the current task has a superior capability
  * in effect, while signalling that this check is being done from within a
- * setid syscall.
+ * setid or setgroups syscall.
  * @ns:  The usernamespace we want the capability in
  * @cap: The capability to be tested for
  *
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
index 809e34a..6e36e85 100644
--- a/kernel/cgroup/cgroup-internal.h
+++ b/kernel/cgroup/cgroup-internal.h
@@ -7,7 +7,7 @@
 #include <linux/workqueue.h>
 #include <linux/list.h>
 #include <linux/refcount.h>
-#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 
 #define TRACE_CGROUP_PATH_LEN 1024
 extern spinlock_t trace_cgroup_path_lock;
@@ -65,6 +65,25 @@
 	return container_of(kfc, struct cgroup_fs_context, kfc);
 }
 
+struct cgroup_pidlist;
+
+struct cgroup_file_ctx {
+	struct cgroup_namespace	*ns;
+
+	struct {
+		void			*trigger;
+	} psi;
+
+	struct {
+		bool			started;
+		struct css_task_iter	iter;
+	} procs;
+
+	struct {
+		struct cgroup_pidlist	*pidlist;
+	} procs1;
+};
+
 /*
  * A cgroup can be associated with multiple css_sets as different tasks may
  * belong to different cgroups on different hierarchies.  In the other
@@ -231,9 +250,10 @@
 
 int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader,
 		       bool threadgroup);
-struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup)
+struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup,
+					     bool *locked)
 	__acquires(&cgroup_threadgroup_rwsem);
-void cgroup_procs_write_finish(struct task_struct *task)
+void cgroup_procs_write_finish(struct task_struct *task, bool locked)
 	__releases(&cgroup_threadgroup_rwsem);
 
 void cgroup_lock_and_drain_offline(struct cgroup *cgrp);
@@ -264,7 +284,7 @@
  */
 extern struct cftype cgroup1_base_files[];
 extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops;
-extern const struct fs_parameter_description cgroup1_fs_parameters;
+extern const struct fs_parameter_spec cgroup1_fs_parameters[];
 
 int proc_cgroupstats_show(struct seq_file *m, void *v);
 bool cgroup1_ssid_disabled(int ssid);
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 2d0ef61..8f0ea12 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -18,8 +18,6 @@
 
 #include <trace/events/cgroup.h>
 
-#define cg_invalf(fc, fmt, ...) invalf(fc, fmt, ## __VA_ARGS__)
-
 /*
  * pidlists linger the following amount before being destroyed.  The goal
  * is avoiding frequent destruction in the middle of consecutive read calls
@@ -40,10 +38,7 @@
  */
 static struct workqueue_struct *cgroup_pidlist_destroy_wq;
 
-/*
- * Protects cgroup_subsys->release_agent_path.  Modifying it also requires
- * cgroup_mutex.  Reading requires either cgroup_mutex or this spinlock.
- */
+/* protects cgroup_subsys->release_agent_path */
 static DEFINE_SPINLOCK(release_agent_path_lock);
 
 bool cgroup1_ssid_disabled(int ssid)
@@ -398,6 +393,7 @@
 	 * next pid to display, if any
 	 */
 	struct kernfs_open_file *of = s->private;
+	struct cgroup_file_ctx *ctx = of->priv;
 	struct cgroup *cgrp = seq_css(s)->cgroup;
 	struct cgroup_pidlist *l;
 	enum cgroup_filetype type = seq_cft(s)->private;
@@ -407,25 +403,24 @@
 	mutex_lock(&cgrp->pidlist_mutex);
 
 	/*
-	 * !NULL @of->priv indicates that this isn't the first start()
-	 * after open.  If the matching pidlist is around, we can use that.
-	 * Look for it.  Note that @of->priv can't be used directly.  It
-	 * could already have been destroyed.
+	 * !NULL @ctx->procs1.pidlist indicates that this isn't the first
+	 * start() after open. If the matching pidlist is around, we can use
+	 * that. Look for it. Note that @ctx->procs1.pidlist can't be used
+	 * directly. It could already have been destroyed.
 	 */
-	if (of->priv)
-		of->priv = cgroup_pidlist_find(cgrp, type);
+	if (ctx->procs1.pidlist)
+		ctx->procs1.pidlist = cgroup_pidlist_find(cgrp, type);
 
 	/*
 	 * Either this is the first start() after open or the matching
 	 * pidlist has been destroyed inbetween.  Create a new one.
 	 */
-	if (!of->priv) {
-		ret = pidlist_array_load(cgrp, type,
-					 (struct cgroup_pidlist **)&of->priv);
+	if (!ctx->procs1.pidlist) {
+		ret = pidlist_array_load(cgrp, type, &ctx->procs1.pidlist);
 		if (ret)
 			return ERR_PTR(ret);
 	}
-	l = of->priv;
+	l = ctx->procs1.pidlist;
 
 	if (pid) {
 		int end = l->length;
@@ -453,7 +448,8 @@
 static void cgroup_pidlist_stop(struct seq_file *s, void *v)
 {
 	struct kernfs_open_file *of = s->private;
-	struct cgroup_pidlist *l = of->priv;
+	struct cgroup_file_ctx *ctx = of->priv;
+	struct cgroup_pidlist *l = ctx->procs1.pidlist;
 
 	if (l)
 		mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork,
@@ -464,7 +460,8 @@
 static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
 {
 	struct kernfs_open_file *of = s->private;
-	struct cgroup_pidlist *l = of->priv;
+	struct cgroup_file_ctx *ctx = of->priv;
+	struct cgroup_pidlist *l = ctx->procs1.pidlist;
 	pid_t *p = v;
 	pid_t *end = l->list + l->length;
 	/*
@@ -496,12 +493,13 @@
 	struct task_struct *task;
 	const struct cred *cred, *tcred;
 	ssize_t ret;
+	bool locked;
 
 	cgrp = cgroup_kn_lock_live(of->kn, false);
 	if (!cgrp)
 		return -ENODEV;
 
-	task = cgroup_procs_write_start(buf, threadgroup);
+	task = cgroup_procs_write_start(buf, threadgroup, &locked);
 	ret = PTR_ERR_OR_ZERO(task);
 	if (ret)
 		goto out_unlock;
@@ -523,7 +521,7 @@
 	ret = cgroup_attach_task(cgrp, task, threadgroup);
 
 out_finish:
-	cgroup_procs_write_finish(task);
+	cgroup_procs_write_finish(task, locked);
 out_unlock:
 	cgroup_kn_unlock(of->kn);
 
@@ -546,9 +544,19 @@
 					  char *buf, size_t nbytes, loff_t off)
 {
 	struct cgroup *cgrp;
+	struct cgroup_file_ctx *ctx;
 
 	BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
 
+	/*
+	 * Release agent gets called with all capabilities,
+	 * require capabilities to set release agent.
+	 */
+	ctx = of->priv;
+	if ((ctx->ns->user_ns != &init_user_ns) ||
+	    !file_ns_capable(of->file, &init_user_ns, CAP_SYS_ADMIN))
+		return -EPERM;
+
 	cgrp = cgroup_kn_lock_live(of->kn, false);
 	if (!cgrp)
 		return -ENODEV;
@@ -776,22 +784,29 @@
 {
 	struct cgroup *cgrp =
 		container_of(work, struct cgroup, release_agent_work);
-	char *pathbuf = NULL, *agentbuf = NULL;
+	char *pathbuf, *agentbuf;
 	char *argv[3], *envp[3];
 	int ret;
 
-	mutex_lock(&cgroup_mutex);
+	/* snoop agent path and exit early if empty */
+	if (!cgrp->root->release_agent_path[0])
+		return;
 
+	/* prepare argument buffers */
 	pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
-	agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
-	if (!pathbuf || !agentbuf || !strlen(agentbuf))
-		goto out;
+	agentbuf = kmalloc(PATH_MAX, GFP_KERNEL);
+	if (!pathbuf || !agentbuf)
+		goto out_free;
 
-	spin_lock_irq(&css_set_lock);
-	ret = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
-	spin_unlock_irq(&css_set_lock);
+	spin_lock(&release_agent_path_lock);
+	strlcpy(agentbuf, cgrp->root->release_agent_path, PATH_MAX);
+	spin_unlock(&release_agent_path_lock);
+	if (!agentbuf[0])
+		goto out_free;
+
+	ret = cgroup_path_ns(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
 	if (ret < 0 || ret >= PATH_MAX)
-		goto out;
+		goto out_free;
 
 	argv[0] = agentbuf;
 	argv[1] = pathbuf;
@@ -802,11 +817,7 @@
 	envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
 	envp[2] = NULL;
 
-	mutex_unlock(&cgroup_mutex);
 	call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
-	goto out_free;
-out:
-	mutex_unlock(&cgroup_mutex);
 out_free:
 	kfree(agentbuf);
 	kfree(pathbuf);
@@ -891,7 +902,7 @@
 	Opt_xattr,
 };
 
-static const struct fs_parameter_spec cgroup1_param_specs[] = {
+const struct fs_parameter_spec cgroup1_fs_parameters[] = {
 	fsparam_flag  ("all",		Opt_all),
 	fsparam_flag  ("clone_children", Opt_clone_children),
 	fsparam_flag  ("cpuset_v2_mode", Opt_cpuset_v2_mode),
@@ -903,11 +914,6 @@
 	{}
 };
 
-const struct fs_parameter_description cgroup1_fs_parameters = {
-	.name		= "cgroup1",
-	.specs		= cgroup1_param_specs,
-};
-
 int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
 	struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
@@ -915,7 +921,7 @@
 	struct fs_parse_result result;
 	int opt, i;
 
-	opt = fs_parse(fc, &cgroup1_fs_parameters, param, &result);
+	opt = fs_parse(fc, cgroup1_fs_parameters, param, &result);
 	if (opt == -ENOPARAM) {
 		if (strcmp(param->key, "source") == 0) {
 			if (param->type != fs_value_is_string)
@@ -929,10 +935,13 @@
 		for_each_subsys(ss, i) {
 			if (strcmp(param->key, ss->legacy_name))
 				continue;
+			if (!cgroup_ssid_enabled(i) || cgroup1_ssid_disabled(i))
+				return invalfc(fc, "Disabled controller '%s'",
+					       param->key);
 			ctx->subsys_mask |= (1 << i);
 			return 0;
 		}
-		return cg_invalf(fc, "cgroup1: Unknown subsys name '%s'", param->key);
+		return invalfc(fc, "Unknown subsys name '%s'", param->key);
 	}
 	if (opt < 0)
 		return opt;
@@ -960,7 +969,13 @@
 	case Opt_release_agent:
 		/* Specifying two release agents is forbidden */
 		if (ctx->release_agent)
-			return cg_invalf(fc, "cgroup1: release_agent respecified");
+			return invalfc(fc, "release_agent respecified");
+		/*
+		 * Release agent gets called with all capabilities,
+		 * require capabilities to set release agent.
+		 */
+		if ((fc->user_ns != &init_user_ns) || !capable(CAP_SYS_ADMIN))
+			return invalfc(fc, "Setting release_agent not allowed");
 		ctx->release_agent = param->string;
 		param->string = NULL;
 		break;
@@ -970,9 +985,9 @@
 			return -ENOENT;
 		/* Can't specify an empty name */
 		if (!param->size)
-			return cg_invalf(fc, "cgroup1: Empty name");
+			return invalfc(fc, "Empty name");
 		if (param->size > MAX_CGROUP_ROOT_NAMELEN - 1)
-			return cg_invalf(fc, "cgroup1: Name too long");
+			return invalfc(fc, "Name too long");
 		/* Must match [\w.-]+ */
 		for (i = 0; i < param->size; i++) {
 			char c = param->string[i];
@@ -980,11 +995,11 @@
 				continue;
 			if ((c == '.') || (c == '-') || (c == '_'))
 				continue;
-			return cg_invalf(fc, "cgroup1: Invalid name");
+			return invalfc(fc, "Invalid name");
 		}
 		/* Specifying two names is forbidden */
 		if (ctx->name)
-			return cg_invalf(fc, "cgroup1: name respecified");
+			return invalfc(fc, "name respecified");
 		ctx->name = param->string;
 		param->string = NULL;
 		break;
@@ -1019,7 +1034,7 @@
 	if (ctx->all_ss) {
 		/* Mutually exclusive option 'all' + subsystem name */
 		if (ctx->subsys_mask)
-			return cg_invalf(fc, "cgroup1: subsys name conflicts with all");
+			return invalfc(fc, "subsys name conflicts with all");
 		/* 'all' => select all the subsystems */
 		ctx->subsys_mask = enabled;
 	}
@@ -1029,7 +1044,7 @@
 	 * empty hierarchies must have a name).
 	 */
 	if (!ctx->subsys_mask && !ctx->name)
-		return cg_invalf(fc, "cgroup1: Need name or subsystem set");
+		return invalfc(fc, "Need name or subsystem set");
 
 	/*
 	 * Option noprefix was introduced just for backward compatibility
@@ -1037,11 +1052,11 @@
 	 * the cpuset subsystem.
 	 */
 	if ((ctx->flags & CGRP_ROOT_NOPREFIX) && (ctx->subsys_mask & mask))
-		return cg_invalf(fc, "cgroup1: noprefix used incorrectly");
+		return invalfc(fc, "noprefix used incorrectly");
 
 	/* Can't specify "none" and some subsystems */
 	if (ctx->subsys_mask && ctx->none)
-		return cg_invalf(fc, "cgroup1: none used incorrectly");
+		return invalfc(fc, "none used incorrectly");
 
 	return 0;
 }
@@ -1071,7 +1086,7 @@
 	/* Don't allow flags or name to change at remount */
 	if ((ctx->flags ^ root->flags) ||
 	    (ctx->name && strcmp(ctx->name, root->name))) {
-		cg_invalf(fc, "option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"",
+		errorfc(fc, "option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"",
 		       ctx->flags, ctx->name ?: "", root->flags, root->name);
 		ret = -EINVAL;
 		goto out_unlock;
@@ -1188,7 +1203,7 @@
 	 * can't create new one without subsys specification.
 	 */
 	if (!ctx->subsys_mask && !ctx->none)
-		return cg_invalf(fc, "cgroup1: No subsys list or none specified");
+		return invalfc(fc, "No subsys list or none specified");
 
 	/* Hierarchies may only be created in the initial cgroup namespace. */
 	if (ctx->ns != &init_cgroup_ns)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index ede370e..3f8447a 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -153,11 +153,7 @@
 
 static DEFINE_PER_CPU(struct cgroup_rstat_cpu, cgrp_dfl_root_rstat_cpu);
 
-/*
- * The default hierarchy, reserved for the subsystems that are otherwise
- * unattached - it never has more than a single cgroup, and all tasks are
- * part of that cgroup.
- */
+/* the default hierarchy */
 struct cgroup_root cgrp_dfl_root = { .cgrp.rstat_cpu = &cgrp_dfl_root_rstat_cpu };
 EXPORT_SYMBOL_GPL(cgrp_dfl_root);
 
@@ -251,9 +247,6 @@
  * cases where a subsystem should behave differnetly depending on the
  * interface version.
  *
- * The set of behaviors which change on the default hierarchy are still
- * being determined and the mount option is prefixed with __DEVEL__.
- *
  * List of changed behaviors:
  *
  * - Mount options "noprefix", "xattr", "clone_children", "release_agent"
@@ -899,8 +892,7 @@
 		/*
 		 * We are synchronized through cgroup_threadgroup_rwsem
 		 * against PF_EXITING setting such that we can't race
-		 * against cgroup_exit() changing the css_set to
-		 * init_css_set and dropping the old one.
+		 * against cgroup_exit()/cgroup_free() dropping the css_set.
 		 */
 		WARN_ON_ONCE(task->flags & PF_EXITING);
 
@@ -1309,10 +1301,7 @@
 
 void cgroup_free_root(struct cgroup_root *root)
 {
-	if (root) {
-		idr_destroy(&root->cgroup_idr);
-		kfree(root);
-	}
+	kfree(root);
 }
 
 static void cgroup_destroy_root(struct cgroup_root *root)
@@ -1374,6 +1363,8 @@
 	cset = current->nsproxy->cgroup_ns->root_cset;
 	if (cset == &init_css_set) {
 		res = &root->cgrp;
+	} else if (root == &cgrp_dfl_root) {
+		res = cset->dfl_cgrp;
 	} else {
 		struct cgrp_cset_link *link;
 
@@ -1430,9 +1421,8 @@
 				     struct cgroup_root *root)
 {
 	/*
-	 * No need to lock the task - since we hold cgroup_mutex the
-	 * task can't change groups, so the only thing that can happen
-	 * is that it exits and its css is set back to init_css_set.
+	 * No need to lock the task - since we hold css_set_lock the
+	 * task can't change groups.
 	 */
 	return cset_cgroup_from_root(task_css_set(task), root);
 }
@@ -1721,6 +1711,7 @@
 	struct cgroup *dcgrp = &dst_root->cgrp;
 	struct cgroup_subsys *ss;
 	int ssid, i, ret;
+	u16 dfl_disable_ss_mask = 0;
 
 	lockdep_assert_held(&cgroup_mutex);
 
@@ -1737,8 +1728,28 @@
 		/* can't move between two non-dummy roots either */
 		if (ss->root != &cgrp_dfl_root && dst_root != &cgrp_dfl_root)
 			return -EBUSY;
+
+		/*
+		 * Collect ssid's that need to be disabled from default
+		 * hierarchy.
+		 */
+		if (ss->root == &cgrp_dfl_root)
+			dfl_disable_ss_mask |= 1 << ssid;
+
 	} while_each_subsys_mask();
 
+	if (dfl_disable_ss_mask) {
+		struct cgroup *scgrp = &cgrp_dfl_root.cgrp;
+
+		/*
+		 * Controllers from default hierarchy that need to be rebound
+		 * are all disabled together in one go.
+		 */
+		cgrp_dfl_root.subsys_mask &= ~dfl_disable_ss_mask;
+		WARN_ON(cgroup_apply_control(scgrp));
+		cgroup_finalize_control(scgrp, 0);
+	}
+
 	do_each_subsys_mask(ss, ssid, ss_mask) {
 		struct cgroup_root *src_root = ss->root;
 		struct cgroup *scgrp = &src_root->cgrp;
@@ -1747,10 +1758,12 @@
 
 		WARN_ON(!css || cgroup_css(dcgrp, ss));
 
-		/* disable from the source */
-		src_root->subsys_mask &= ~(1 << ssid);
-		WARN_ON(cgroup_apply_control(scgrp));
-		cgroup_finalize_control(scgrp, 0);
+		if (src_root != &cgrp_dfl_root) {
+			/* disable from the source */
+			src_root->subsys_mask &= ~(1 << ssid);
+			WARN_ON(cgroup_apply_control(scgrp));
+			cgroup_finalize_control(scgrp, 0);
+		}
 
 		/* rebind */
 		RCU_INIT_POINTER(scgrp->subsys[ssid], NULL);
@@ -1816,27 +1829,24 @@
 enum cgroup2_param {
 	Opt_nsdelegate,
 	Opt_memory_localevents,
+	Opt_memory_recursiveprot,
 	nr__cgroup2_params
 };
 
-static const struct fs_parameter_spec cgroup2_param_specs[] = {
+static const struct fs_parameter_spec cgroup2_fs_parameters[] = {
 	fsparam_flag("nsdelegate",		Opt_nsdelegate),
 	fsparam_flag("memory_localevents",	Opt_memory_localevents),
+	fsparam_flag("memory_recursiveprot",	Opt_memory_recursiveprot),
 	{}
 };
 
-static const struct fs_parameter_description cgroup2_fs_parameters = {
-	.name		= "cgroup2",
-	.specs		= cgroup2_param_specs,
-};
-
 static int cgroup2_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
 	struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
 	struct fs_parse_result result;
 	int opt;
 
-	opt = fs_parse(fc, &cgroup2_fs_parameters, param, &result);
+	opt = fs_parse(fc, cgroup2_fs_parameters, param, &result);
 	if (opt < 0)
 		return opt;
 
@@ -1847,6 +1857,9 @@
 	case Opt_memory_localevents:
 		ctx->flags |= CGRP_ROOT_MEMORY_LOCAL_EVENTS;
 		return 0;
+	case Opt_memory_recursiveprot:
+		ctx->flags |= CGRP_ROOT_MEMORY_RECURSIVE_PROT;
+		return 0;
 	}
 	return -EINVAL;
 }
@@ -1863,6 +1876,11 @@
 			cgrp_dfl_root.flags |= CGRP_ROOT_MEMORY_LOCAL_EVENTS;
 		else
 			cgrp_dfl_root.flags &= ~CGRP_ROOT_MEMORY_LOCAL_EVENTS;
+
+		if (root_flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)
+			cgrp_dfl_root.flags |= CGRP_ROOT_MEMORY_RECURSIVE_PROT;
+		else
+			cgrp_dfl_root.flags &= ~CGRP_ROOT_MEMORY_RECURSIVE_PROT;
 	}
 }
 
@@ -1872,6 +1890,8 @@
 		seq_puts(seq, ",nsdelegate");
 	if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
 		seq_puts(seq, ",memory_localevents");
+	if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)
+		seq_puts(seq, ",memory_recursiveprot");
 	return 0;
 }
 
@@ -1883,65 +1903,6 @@
 	return 0;
 }
 
-/*
- * To reduce the fork() overhead for systems that are not actually using
- * their cgroups capability, we don't maintain the lists running through
- * each css_set to its tasks until we see the list actually used - in other
- * words after the first mount.
- */
-static bool use_task_css_set_links __read_mostly;
-
-void cgroup_enable_task_cg_lists(void)
-{
-	struct task_struct *p, *g;
-
-	/*
-	 * We need tasklist_lock because RCU is not safe against
-	 * while_each_thread(). Besides, a forking task that has passed
-	 * cgroup_post_fork() without seeing use_task_css_set_links = 1
-	 * is not guaranteed to have its child immediately visible in the
-	 * tasklist if we walk through it with RCU.
-	 */
-	read_lock(&tasklist_lock);
-	spin_lock_irq(&css_set_lock);
-
-	if (use_task_css_set_links)
-		goto out_unlock;
-
-	use_task_css_set_links = true;
-
-	do_each_thread(g, p) {
-		WARN_ON_ONCE(!list_empty(&p->cg_list) ||
-			     task_css_set(p) != &init_css_set);
-
-		/*
-		 * We should check if the process is exiting, otherwise
-		 * it will race with cgroup_exit() in that the list
-		 * entry won't be deleted though the process has exited.
-		 * Do it while holding siglock so that we don't end up
-		 * racing against cgroup_exit().
-		 *
-		 * Interrupts were already disabled while acquiring
-		 * the css_set_lock, so we do not need to disable it
-		 * again when acquiring the sighand->siglock here.
-		 */
-		spin_lock(&p->sighand->siglock);
-		if (!(p->flags & PF_EXITING)) {
-			struct css_set *cset = task_css_set(p);
-
-			if (!css_set_populated(cset))
-				css_set_update_populated(cset, true);
-			list_add_tail(&p->cg_list, &cset->tasks);
-			get_css_set(cset);
-			cset->nr_tasks++;
-		}
-		spin_unlock(&p->sighand->siglock);
-	} while_each_thread(g, p);
-out_unlock:
-	spin_unlock_irq(&css_set_lock);
-	read_unlock(&tasklist_lock);
-}
-
 static void init_cgroup_housekeeping(struct cgroup *cgrp)
 {
 	struct cgroup_subsys *ss;
@@ -1976,7 +1937,6 @@
 	atomic_set(&root->nr_cgrps, 1);
 	cgrp->root = root;
 	init_cgroup_housekeeping(cgrp);
-	idr_init(&root->cgroup_idr);
 
 	root->flags = ctx->flags;
 	if (ctx->release_agent)
@@ -1997,12 +1957,6 @@
 
 	lockdep_assert_held(&cgroup_mutex);
 
-	ret = cgroup_idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_KERNEL);
-	if (ret < 0)
-		goto out;
-	root_cgrp->id = ret;
-	root_cgrp->ancestor_ids[0] = ret;
-
 	ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release,
 			      0, GFP_KERNEL);
 	if (ret)
@@ -2028,13 +1982,16 @@
 
 	root->kf_root = kernfs_create_root(kf_sops,
 					   KERNFS_ROOT_CREATE_DEACTIVATED |
-					   KERNFS_ROOT_SUPPORT_EXPORTOP,
+					   KERNFS_ROOT_SUPPORT_EXPORTOP |
+					   KERNFS_ROOT_SUPPORT_USER_XATTR,
 					   root_cgrp);
 	if (IS_ERR(root->kf_root)) {
 		ret = PTR_ERR(root->kf_root);
 		goto exit_root_id;
 	}
 	root_cgrp->kn = root->kf_root->kn;
+	WARN_ON_ONCE(cgroup_ino(root_cgrp) != 1);
+	root_cgrp->ancestor_ids[0] = cgroup_id(root_cgrp);
 
 	ret = css_populate_dir(&root_cgrp->self);
 	if (ret)
@@ -2072,7 +2029,6 @@
 	BUG_ON(!list_empty(&root_cgrp->self.children));
 	BUG_ON(atomic_read(&root->nr_cgrps) != 1);
 
-	kernfs_activate(root_cgrp->kn);
 	ret = 0;
 	goto out;
 
@@ -2188,13 +2144,6 @@
 	if (!ctx)
 		return -ENOMEM;
 
-	/*
-	 * The first time anyone tries to mount a cgroup, enable the list
-	 * linking each css_set to its tasks and fix up all existing tasks.
-	 */
-	if (!use_task_css_set_links)
-		cgroup_enable_task_cg_lists();
-
 	ctx->ns = current->nsproxy->cgroup_ns;
 	get_cgroup_ns(ctx->ns);
 	fc->fs_private = &ctx->kfc;
@@ -2221,8 +2170,10 @@
 	 * And don't kill the default root.
 	 */
 	if (list_empty(&root->cgrp.self.children) && root != &cgrp_dfl_root &&
-	    !percpu_ref_is_dying(&root->cgrp.self.refcnt))
+	    !percpu_ref_is_dying(&root->cgrp.self.refcnt)) {
+		cgroup_bpf_offline(&root->cgrp);
 		percpu_ref_kill(&root->cgrp.self.refcnt);
+	}
 	cgroup_put(&root->cgrp);
 	kernfs_kill_sb(sb);
 }
@@ -2230,7 +2181,7 @@
 struct file_system_type cgroup_fs_type = {
 	.name			= "cgroup",
 	.init_fs_context	= cgroup_init_fs_context,
-	.parameters		= &cgroup1_fs_parameters,
+	.parameters		= cgroup1_fs_parameters,
 	.kill_sb		= cgroup_kill_sb,
 	.fs_flags		= FS_USERNS_MOUNT,
 };
@@ -2238,7 +2189,7 @@
 static struct file_system_type cgroup2_fs_type = {
 	.name			= "cgroup2",
 	.init_fs_context	= cgroup_init_fs_context,
-	.parameters		= &cgroup2_fs_parameters,
+	.parameters		= cgroup2_fs_parameters,
 	.kill_sb		= cgroup_kill_sb,
 	.fs_flags		= FS_USERNS_MOUNT,
 };
@@ -2372,9 +2323,8 @@
 	if (task->flags & PF_EXITING)
 		return;
 
-	/* leave @task alone if post_fork() hasn't linked it yet */
-	if (list_empty(&task->cg_list))
-		return;
+	/* cgroup_threadgroup_rwsem protects racing against forks */
+	WARN_ON_ONCE(list_empty(&task->cg_list));
 
 	cset = task_css_set(task);
 	if (!cset->mg_src_cgrp)
@@ -2794,11 +2744,7 @@
 {
 	DEFINE_CGROUP_MGCTX(mgctx);
 	struct task_struct *task;
-	int ret;
-
-	ret = cgroup_migrate_vet_dst(dst_cgrp);
-	if (ret)
-		return ret;
+	int ret = 0;
 
 	/* look up all src csets */
 	spin_lock_irq(&css_set_lock);
@@ -2825,7 +2771,8 @@
 	return ret;
 }
 
-struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup)
+struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup,
+					     bool *locked)
 	__acquires(&cgroup_threadgroup_rwsem)
 {
 	struct task_struct *tsk;
@@ -2834,7 +2781,21 @@
 	if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
 		return ERR_PTR(-EINVAL);
 
-	percpu_down_write(&cgroup_threadgroup_rwsem);
+	/*
+	 * If we migrate a single thread, we don't care about threadgroup
+	 * stability. If the thread is `current`, it won't exit(2) under our
+	 * hands or change PID through exec(2). We exclude
+	 * cgroup_update_dfl_csses and other cgroup_{proc,thread}s_write
+	 * callers by cgroup_mutex.
+	 * Therefore, we can skip the global lock.
+	 */
+	lockdep_assert_held(&cgroup_mutex);
+	if (pid || threadgroup) {
+		percpu_down_write(&cgroup_threadgroup_rwsem);
+		*locked = true;
+	} else {
+		*locked = false;
+	}
 
 	rcu_read_lock();
 	if (pid) {
@@ -2865,13 +2826,16 @@
 	goto out_unlock_rcu;
 
 out_unlock_threadgroup:
-	percpu_up_write(&cgroup_threadgroup_rwsem);
+	if (*locked) {
+		percpu_up_write(&cgroup_threadgroup_rwsem);
+		*locked = false;
+	}
 out_unlock_rcu:
 	rcu_read_unlock();
 	return tsk;
 }
 
-void cgroup_procs_write_finish(struct task_struct *task)
+void cgroup_procs_write_finish(struct task_struct *task, bool locked)
 	__releases(&cgroup_threadgroup_rwsem)
 {
 	struct cgroup_subsys *ss;
@@ -2880,7 +2844,8 @@
 	/* release reference from cgroup_procs_write_start() */
 	put_task_struct(task);
 
-	percpu_up_write(&cgroup_threadgroup_rwsem);
+	if (locked)
+		percpu_up_write(&cgroup_threadgroup_rwsem);
 	for_each_subsys(ss, ssid)
 		if (ss->post_attach)
 			ss->post_attach();
@@ -3602,22 +3567,22 @@
 #ifdef CONFIG_PSI
 static int cgroup_io_pressure_show(struct seq_file *seq, void *v)
 {
-	struct cgroup *cgroup = seq_css(seq)->cgroup;
-	struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
+	struct cgroup *cgrp = seq_css(seq)->cgroup;
+	struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
 
 	return psi_show(seq, psi, PSI_IO);
 }
 static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)
 {
-	struct cgroup *cgroup = seq_css(seq)->cgroup;
-	struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
+	struct cgroup *cgrp = seq_css(seq)->cgroup;
+	struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
 
 	return psi_show(seq, psi, PSI_MEM);
 }
 static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)
 {
-	struct cgroup *cgroup = seq_css(seq)->cgroup;
-	struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
+	struct cgroup *cgrp = seq_css(seq)->cgroup;
+	struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
 
 	return psi_show(seq, psi, PSI_CPU);
 }
@@ -3625,6 +3590,7 @@
 static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
 					  size_t nbytes, enum psi_res res)
 {
+	struct cgroup_file_ctx *ctx = of->priv;
 	struct psi_trigger *new;
 	struct cgroup *cgrp;
 	struct psi_group *psi;
@@ -3636,6 +3602,12 @@
 	cgroup_get(cgrp);
 	cgroup_kn_unlock(of->kn);
 
+	/* Allow only one trigger per file descriptor */
+	if (ctx->psi.trigger) {
+		cgroup_put(cgrp);
+		return -EBUSY;
+	}
+
 	psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
 	new = psi_trigger_create(psi, buf, nbytes, res);
 	if (IS_ERR(new)) {
@@ -3643,8 +3615,7 @@
 		return PTR_ERR(new);
 	}
 
-	psi_trigger_replace(&of->priv, new);
-
+	smp_store_release(&ctx->psi.trigger, new);
 	cgroup_put(cgrp);
 
 	return nbytes;
@@ -3674,12 +3645,15 @@
 static __poll_t cgroup_pressure_poll(struct kernfs_open_file *of,
 					  poll_table *pt)
 {
-	return psi_trigger_poll(&of->priv, of->file, pt);
+	struct cgroup_file_ctx *ctx = of->priv;
+	return psi_trigger_poll(&ctx->psi.trigger, of->file, pt);
 }
 
 static void cgroup_pressure_release(struct kernfs_open_file *of)
 {
-	psi_trigger_replace(&of->priv, NULL);
+	struct cgroup_file_ctx *ctx = of->priv;
+
+	psi_trigger_destroy(ctx->psi.trigger);
 }
 #endif /* CONFIG_PSI */
 
@@ -3720,29 +3694,51 @@
 static int cgroup_file_open(struct kernfs_open_file *of)
 {
 	struct cftype *cft = of->kn->priv;
+	struct cgroup_file_ctx *ctx;
+	int ret;
 
-	if (cft->open)
-		return cft->open(of);
-	return 0;
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->ns = current->nsproxy->cgroup_ns;
+	get_cgroup_ns(ctx->ns);
+	of->priv = ctx;
+
+	if (!cft->open)
+		return 0;
+
+	ret = cft->open(of);
+	if (ret) {
+		put_cgroup_ns(ctx->ns);
+		kfree(ctx);
+	}
+	return ret;
 }
 
 static void cgroup_file_release(struct kernfs_open_file *of)
 {
 	struct cftype *cft = of->kn->priv;
+	struct cgroup_file_ctx *ctx = of->priv;
 
 	if (cft->release)
 		cft->release(of);
+	put_cgroup_ns(ctx->ns);
+	kfree(ctx);
 }
 
 static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf,
 				 size_t nbytes, loff_t off)
 {
-	struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
+	struct cgroup_file_ctx *ctx = of->priv;
 	struct cgroup *cgrp = of->kn->parent->priv;
 	struct cftype *cft = of->kn->priv;
 	struct cgroup_subsys_state *css;
 	int ret;
 
+	if (!nbytes)
+		return 0;
+
 	/*
 	 * If namespaces are delegation boundaries, disallow writes to
 	 * files in an non-init namespace root from inside the namespace
@@ -3751,7 +3747,7 @@
 	 */
 	if ((cgrp->root->flags & CGRP_ROOT_NS_DELEGATE) &&
 	    !(cft->flags & CFTYPE_NS_DELEGATABLE) &&
-	    ns != &init_cgroup_ns && ns->root_cset->dfl_cgrp == cgrp)
+	    ctx->ns != &init_cgroup_ns && ctx->ns->root_cset->dfl_cgrp == cgrp)
 		return -EPERM;
 
 	if (cft->write)
@@ -4211,7 +4207,8 @@
 	} else if (likely(!(pos->flags & CSS_RELEASED))) {
 		next = list_entry_rcu(pos->sibling.next, struct cgroup_subsys_state, sibling);
 	} else {
-		list_for_each_entry_rcu(next, &parent->children, sibling)
+		list_for_each_entry_rcu(next, &parent->children, sibling,
+					lockdep_is_held(&cgroup_mutex))
 			if (next->serial_nr > pos->serial_nr)
 				break;
 	}
@@ -4454,29 +4451,24 @@
 
 	lockdep_assert_held(&css_set_lock);
 
-	/* Advance to the next non-empty css_set */
-	do {
-		cset = css_task_iter_next_css_set(it);
-		if (!cset) {
-			it->task_pos = NULL;
-			return;
+	/* Advance to the next non-empty css_set and find first non-empty tasks list*/
+	while ((cset = css_task_iter_next_css_set(it))) {
+		if (!list_empty(&cset->tasks)) {
+			it->cur_tasks_head = &cset->tasks;
+			break;
+		} else if (!list_empty(&cset->mg_tasks)) {
+			it->cur_tasks_head = &cset->mg_tasks;
+			break;
+		} else if (!list_empty(&cset->dying_tasks)) {
+			it->cur_tasks_head = &cset->dying_tasks;
+			break;
 		}
-	} while (!css_set_populated(cset) && list_empty(&cset->dying_tasks));
-
-	if (!list_empty(&cset->tasks)) {
-		it->task_pos = cset->tasks.next;
-		it->cur_tasks_head = &cset->tasks;
-	} else if (!list_empty(&cset->mg_tasks)) {
-		it->task_pos = cset->mg_tasks.next;
-		it->cur_tasks_head = &cset->mg_tasks;
-	} else {
-		it->task_pos = cset->dying_tasks.next;
-		it->cur_tasks_head = &cset->dying_tasks;
 	}
-
-	it->tasks_head = &cset->tasks;
-	it->mg_tasks_head = &cset->mg_tasks;
-	it->dying_tasks_head = &cset->dying_tasks;
+	if (!cset) {
+		it->task_pos = NULL;
+		return;
+	}
+	it->task_pos = it->cur_tasks_head->next;
 
 	/*
 	 * We don't keep css_sets locked across iteration steps and thus
@@ -4521,24 +4513,24 @@
 repeat:
 	if (it->task_pos) {
 		/*
-		 * Advance iterator to find next entry.  cset->tasks is
-		 * consumed first and then ->mg_tasks.  After ->mg_tasks,
-		 * we move onto the next cset.
+		 * Advance iterator to find next entry. We go through cset
+		 * tasks, mg_tasks and dying_tasks, when consumed we move onto
+		 * the next cset.
 		 */
 		if (it->flags & CSS_TASK_ITER_SKIPPED)
 			it->flags &= ~CSS_TASK_ITER_SKIPPED;
 		else
 			it->task_pos = it->task_pos->next;
 
-		if (it->task_pos == it->tasks_head) {
-			it->task_pos = it->mg_tasks_head->next;
-			it->cur_tasks_head = it->mg_tasks_head;
+		if (it->task_pos == &it->cur_cset->tasks) {
+			it->cur_tasks_head = &it->cur_cset->mg_tasks;
+			it->task_pos = it->cur_tasks_head->next;
 		}
-		if (it->task_pos == it->mg_tasks_head) {
-			it->task_pos = it->dying_tasks_head->next;
-			it->cur_tasks_head = it->dying_tasks_head;
+		if (it->task_pos == &it->cur_cset->mg_tasks) {
+			it->cur_tasks_head = &it->cur_cset->dying_tasks;
+			it->task_pos = it->cur_tasks_head->next;
 		}
-		if (it->task_pos == it->dying_tasks_head)
+		if (it->task_pos == &it->cur_cset->dying_tasks)
 			css_task_iter_advance_css_set(it);
 	} else {
 		/* called from start, proceed to the first cset */
@@ -4556,12 +4548,12 @@
 			goto repeat;
 
 		/* and dying leaders w/o live member threads */
-		if (it->cur_tasks_head == it->dying_tasks_head &&
+		if (it->cur_tasks_head == &it->cur_cset->dying_tasks &&
 		    !atomic_read(&task->signal->live))
 			goto repeat;
 	} else {
 		/* skip all dying ones */
-		if (it->cur_tasks_head == it->dying_tasks_head)
+		if (it->cur_tasks_head == &it->cur_cset->dying_tasks)
 			goto repeat;
 	}
 }
@@ -4580,9 +4572,6 @@
 void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,
 			 struct css_task_iter *it)
 {
-	/* no one should try to iterate before mounting cgroups */
-	WARN_ON_ONCE(!use_task_css_set_links);
-
 	memset(it, 0, sizeof(*it));
 
 	spin_lock_irq(&css_set_lock);
@@ -4659,21 +4648,21 @@
 
 static void cgroup_procs_release(struct kernfs_open_file *of)
 {
-	if (of->priv) {
-		css_task_iter_end(of->priv);
-		kfree(of->priv);
-	}
+	struct cgroup_file_ctx *ctx = of->priv;
+
+	if (ctx->procs.started)
+		css_task_iter_end(&ctx->procs.iter);
 }
 
 static void *cgroup_procs_next(struct seq_file *s, void *v, loff_t *pos)
 {
 	struct kernfs_open_file *of = s->private;
-	struct css_task_iter *it = of->priv;
+	struct cgroup_file_ctx *ctx = of->priv;
 
 	if (pos)
 		(*pos)++;
 
-	return css_task_iter_next(it);
+	return css_task_iter_next(&ctx->procs.iter);
 }
 
 static void *__cgroup_procs_start(struct seq_file *s, loff_t *pos,
@@ -4681,21 +4670,18 @@
 {
 	struct kernfs_open_file *of = s->private;
 	struct cgroup *cgrp = seq_css(s)->cgroup;
-	struct css_task_iter *it = of->priv;
+	struct cgroup_file_ctx *ctx = of->priv;
+	struct css_task_iter *it = &ctx->procs.iter;
 
 	/*
 	 * When a seq_file is seeked, it's always traversed sequentially
 	 * from position 0, so we can simply keep iterating on !0 *pos.
 	 */
-	if (!it) {
+	if (!ctx->procs.started) {
 		if (WARN_ON_ONCE((*pos)))
 			return ERR_PTR(-EINVAL);
-
-		it = kzalloc(sizeof(*it), GFP_KERNEL);
-		if (!it)
-			return ERR_PTR(-ENOMEM);
-		of->priv = it;
 		css_task_iter_start(&cgrp->self, iter_flags, it);
+		ctx->procs.started = true;
 	} else if (!(*pos)) {
 		css_task_iter_end(it);
 		css_task_iter_start(&cgrp->self, iter_flags, it);
@@ -4728,13 +4714,28 @@
 	return 0;
 }
 
+static int cgroup_may_write(const struct cgroup *cgrp, struct super_block *sb)
+{
+	int ret;
+	struct inode *inode;
+
+	lockdep_assert_held(&cgroup_mutex);
+
+	inode = kernfs_get_inode(sb, cgrp->procs_file.kn);
+	if (!inode)
+		return -ENOMEM;
+
+	ret = inode_permission(inode, MAY_WRITE);
+	iput(inode);
+	return ret;
+}
+
 static int cgroup_procs_write_permission(struct cgroup *src_cgrp,
 					 struct cgroup *dst_cgrp,
-					 struct super_block *sb)
+					 struct super_block *sb,
+					 struct cgroup_namespace *ns)
 {
-	struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
 	struct cgroup *com_cgrp = src_cgrp;
-	struct inode *inode;
 	int ret;
 
 	lockdep_assert_held(&cgroup_mutex);
@@ -4744,12 +4745,7 @@
 		com_cgrp = cgroup_parent(com_cgrp);
 
 	/* %current should be authorized to migrate to the common ancestor */
-	inode = kernfs_get_inode(sb, com_cgrp->procs_file.kn);
-	if (!inode)
-		return -ENOMEM;
-
-	ret = inode_permission(inode, MAY_WRITE);
-	iput(inode);
+	ret = cgroup_may_write(com_cgrp, sb);
 	if (ret)
 		return ret;
 
@@ -4765,18 +4761,41 @@
 	return 0;
 }
 
+static int cgroup_attach_permissions(struct cgroup *src_cgrp,
+				     struct cgroup *dst_cgrp,
+				     struct super_block *sb, bool threadgroup,
+				     struct cgroup_namespace *ns)
+{
+	int ret = 0;
+
+	ret = cgroup_procs_write_permission(src_cgrp, dst_cgrp, sb, ns);
+	if (ret)
+		return ret;
+
+	ret = cgroup_migrate_vet_dst(dst_cgrp);
+	if (ret)
+		return ret;
+
+	if (!threadgroup && (src_cgrp->dom_cgrp != dst_cgrp->dom_cgrp))
+		ret = -EOPNOTSUPP;
+
+	return ret;
+}
+
 static ssize_t cgroup_procs_write(struct kernfs_open_file *of,
 				  char *buf, size_t nbytes, loff_t off)
 {
+	struct cgroup_file_ctx *ctx = of->priv;
 	struct cgroup *src_cgrp, *dst_cgrp;
 	struct task_struct *task;
 	ssize_t ret;
+	bool locked;
 
 	dst_cgrp = cgroup_kn_lock_live(of->kn, false);
 	if (!dst_cgrp)
 		return -ENODEV;
 
-	task = cgroup_procs_write_start(buf, true);
+	task = cgroup_procs_write_start(buf, true, &locked);
 	ret = PTR_ERR_OR_ZERO(task);
 	if (ret)
 		goto out_unlock;
@@ -4786,15 +4805,16 @@
 	src_cgrp = task_cgroup_from_root(task, &cgrp_dfl_root);
 	spin_unlock_irq(&css_set_lock);
 
-	ret = cgroup_procs_write_permission(src_cgrp, dst_cgrp,
-					    of->file->f_path.dentry->d_sb);
+	ret = cgroup_attach_permissions(src_cgrp, dst_cgrp,
+					of->file->f_path.dentry->d_sb, true,
+					ctx->ns);
 	if (ret)
 		goto out_finish;
 
 	ret = cgroup_attach_task(dst_cgrp, task, true);
 
 out_finish:
-	cgroup_procs_write_finish(task);
+	cgroup_procs_write_finish(task, locked);
 out_unlock:
 	cgroup_kn_unlock(of->kn);
 
@@ -4809,9 +4829,11 @@
 static ssize_t cgroup_threads_write(struct kernfs_open_file *of,
 				    char *buf, size_t nbytes, loff_t off)
 {
+	struct cgroup_file_ctx *ctx = of->priv;
 	struct cgroup *src_cgrp, *dst_cgrp;
 	struct task_struct *task;
 	ssize_t ret;
+	bool locked;
 
 	buf = strstrip(buf);
 
@@ -4819,7 +4841,7 @@
 	if (!dst_cgrp)
 		return -ENODEV;
 
-	task = cgroup_procs_write_start(buf, false);
+	task = cgroup_procs_write_start(buf, false, &locked);
 	ret = PTR_ERR_OR_ZERO(task);
 	if (ret)
 		goto out_unlock;
@@ -4830,20 +4852,16 @@
 	spin_unlock_irq(&css_set_lock);
 
 	/* thread migrations follow the cgroup.procs delegation rule */
-	ret = cgroup_procs_write_permission(src_cgrp, dst_cgrp,
-					    of->file->f_path.dentry->d_sb);
+	ret = cgroup_attach_permissions(src_cgrp, dst_cgrp,
+					of->file->f_path.dentry->d_sb, false,
+					ctx->ns);
 	if (ret)
 		goto out_finish;
 
-	/* and must be contained in the same domain */
-	ret = -EOPNOTSUPP;
-	if (src_cgrp->dom_cgrp != dst_cgrp->dom_cgrp)
-		goto out_finish;
-
 	ret = cgroup_attach_task(dst_cgrp, task, false);
 
 out_finish:
-	cgroup_procs_write_finish(task);
+	cgroup_procs_write_finish(task, locked);
 out_unlock:
 	cgroup_kn_unlock(of->kn);
 
@@ -4915,7 +4933,6 @@
 	},
 	{
 		.name = "cpu.stat",
-		.flags = CFTYPE_NOT_ON_ROOT,
 		.seq_show = cpu_stat_show,
 	},
 #ifdef CONFIG_PSI
@@ -5053,9 +5070,6 @@
 			tcgrp->nr_dying_descendants--;
 		spin_unlock_irq(&css_set_lock);
 
-		cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
-		cgrp->id = -1;
-
 		/*
 		 * There are two control paths which try to determine
 		 * cgroup from dentry without going through kernfs -
@@ -5220,10 +5234,12 @@
  * it isn't associated with its kernfs_node and doesn't have the control
  * mask applied.
  */
-static struct cgroup *cgroup_create(struct cgroup *parent)
+static struct cgroup *cgroup_create(struct cgroup *parent, const char *name,
+				    umode_t mode)
 {
 	struct cgroup_root *root = parent->root;
 	struct cgroup *cgrp, *tcgrp;
+	struct kernfs_node *kn;
 	int level = parent->level + 1;
 	int ret;
 
@@ -5243,15 +5259,13 @@
 			goto out_cancel_ref;
 	}
 
-	/*
-	 * Temporarily set the pointer to NULL, so idr_find() won't return
-	 * a half-baked cgroup.
-	 */
-	cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_KERNEL);
-	if (cgrp->id < 0) {
-		ret = -ENOMEM;
+	/* create the directory */
+	kn = kernfs_create_dir(parent->kn, name, mode, cgrp);
+	if (IS_ERR(kn)) {
+		ret = PTR_ERR(kn);
 		goto out_stat_exit;
 	}
+	cgrp->kn = kn;
 
 	init_cgroup_housekeeping(cgrp);
 
@@ -5261,7 +5275,7 @@
 
 	ret = psi_cgroup_alloc(cgrp);
 	if (ret)
-		goto out_idr_free;
+		goto out_kernfs_remove;
 
 	ret = cgroup_bpf_inherit(cgrp);
 	if (ret)
@@ -5285,7 +5299,7 @@
 
 	spin_lock_irq(&css_set_lock);
 	for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) {
-		cgrp->ancestor_ids[tcgrp->level] = tcgrp->id;
+		cgrp->ancestor_ids[tcgrp->level] = cgroup_id(tcgrp);
 
 		if (tcgrp != cgrp) {
 			tcgrp->nr_descendants++;
@@ -5315,12 +5329,6 @@
 	cgroup_get_live(parent);
 
 	/*
-	 * @cgrp is now fully operational.  If something fails after this
-	 * point, it'll be released via the normal destruction path.
-	 */
-	cgroup_idr_replace(&root->cgroup_idr, cgrp, cgrp->id);
-
-	/*
 	 * On the default hierarchy, a child doesn't automatically inherit
 	 * subtree_control from the parent.  Each is configured manually.
 	 */
@@ -5333,8 +5341,8 @@
 
 out_psi_free:
 	psi_cgroup_free(cgrp);
-out_idr_free:
-	cgroup_idr_remove(&root->cgroup_idr, cgrp->id);
+out_kernfs_remove:
+	kernfs_remove(cgrp->kn);
 out_stat_exit:
 	if (cgroup_on_dfl(parent))
 		cgroup_rstat_exit(cgrp);
@@ -5371,7 +5379,6 @@
 int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode)
 {
 	struct cgroup *parent, *cgrp;
-	struct kernfs_node *kn;
 	int ret;
 
 	/* do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable */
@@ -5387,27 +5394,19 @@
 		goto out_unlock;
 	}
 
-	cgrp = cgroup_create(parent);
+	cgrp = cgroup_create(parent, name, mode);
 	if (IS_ERR(cgrp)) {
 		ret = PTR_ERR(cgrp);
 		goto out_unlock;
 	}
 
-	/* create the directory */
-	kn = kernfs_create_dir(parent->kn, name, mode, cgrp);
-	if (IS_ERR(kn)) {
-		ret = PTR_ERR(kn);
-		goto out_destroy;
-	}
-	cgrp->kn = kn;
-
 	/*
 	 * This extra ref will be put in cgroup_free_fn() and guarantees
 	 * that @cgrp->kn is always accessible.
 	 */
-	kernfs_get(kn);
+	kernfs_get(cgrp->kn);
 
-	ret = cgroup_kn_set_ugid(kn);
+	ret = cgroup_kn_set_ugid(cgrp->kn);
 	if (ret)
 		goto out_destroy;
 
@@ -5422,7 +5421,7 @@
 	TRACE_CGROUP_PATH(mkdir, cgrp);
 
 	/* let's create and online css's */
-	kernfs_activate(kn);
+	kernfs_activate(cgrp->kn);
 
 	ret = 0;
 	goto out_unlock;
@@ -5846,12 +5845,11 @@
 }
 core_initcall(cgroup_wq_init);
 
-void cgroup_path_from_kernfs_id(const union kernfs_node_id *id,
-					char *buf, size_t buflen)
+void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
 {
 	struct kernfs_node *kn;
 
-	kn = kernfs_get_node_by_id(cgrp_dfl_root.kf_root, id);
+	kn = kernfs_find_and_get_node_by_id(cgrp_dfl_root.kf_root, id);
 	if (!kn)
 		return;
 	kernfs_path(kn, buf, buflen);
@@ -5941,8 +5939,7 @@
  * @child: pointer to task_struct of forking parent process.
  *
  * A task is associated with the init_css_set until cgroup_post_fork()
- * attaches it to the parent's css_set.  Empty cg_list indicates that
- * @child isn't holding reference to its css_set.
+ * attaches it to the target css_set.
  */
 void cgroup_fork(struct task_struct *child)
 {
@@ -5950,21 +5947,173 @@
 	INIT_LIST_HEAD(&child->cg_list);
 }
 
+static struct cgroup *cgroup_get_from_file(struct file *f)
+{
+	struct cgroup_subsys_state *css;
+	struct cgroup *cgrp;
+
+	css = css_tryget_online_from_dir(f->f_path.dentry, NULL);
+	if (IS_ERR(css))
+		return ERR_CAST(css);
+
+	cgrp = css->cgroup;
+	if (!cgroup_on_dfl(cgrp)) {
+		cgroup_put(cgrp);
+		return ERR_PTR(-EBADF);
+	}
+
+	return cgrp;
+}
+
+/**
+ * cgroup_css_set_fork - find or create a css_set for a child process
+ * @kargs: the arguments passed to create the child process
+ *
+ * This functions finds or creates a new css_set which the child
+ * process will be attached to in cgroup_post_fork(). By default,
+ * the child process will be given the same css_set as its parent.
+ *
+ * If CLONE_INTO_CGROUP is specified this function will try to find an
+ * existing css_set which includes the requested cgroup and if not create
+ * a new css_set that the child will be attached to later. If this function
+ * succeeds it will hold cgroup_threadgroup_rwsem on return. If
+ * CLONE_INTO_CGROUP is requested this function will grab cgroup mutex
+ * before grabbing cgroup_threadgroup_rwsem and will hold a reference
+ * to the target cgroup.
+ */
+static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
+	__acquires(&cgroup_mutex) __acquires(&cgroup_threadgroup_rwsem)
+{
+	int ret;
+	struct cgroup *dst_cgrp = NULL;
+	struct css_set *cset;
+	struct super_block *sb;
+	struct file *f;
+
+	if (kargs->flags & CLONE_INTO_CGROUP)
+		mutex_lock(&cgroup_mutex);
+
+	cgroup_threadgroup_change_begin(current);
+
+	spin_lock_irq(&css_set_lock);
+	cset = task_css_set(current);
+	get_css_set(cset);
+	spin_unlock_irq(&css_set_lock);
+
+	if (!(kargs->flags & CLONE_INTO_CGROUP)) {
+		kargs->cset = cset;
+		return 0;
+	}
+
+	f = fget_raw(kargs->cgroup);
+	if (!f) {
+		ret = -EBADF;
+		goto err;
+	}
+	sb = f->f_path.dentry->d_sb;
+
+	dst_cgrp = cgroup_get_from_file(f);
+	if (IS_ERR(dst_cgrp)) {
+		ret = PTR_ERR(dst_cgrp);
+		dst_cgrp = NULL;
+		goto err;
+	}
+
+	if (cgroup_is_dead(dst_cgrp)) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	/*
+	 * Verify that we the target cgroup is writable for us. This is
+	 * usually done by the vfs layer but since we're not going through
+	 * the vfs layer here we need to do it "manually".
+	 */
+	ret = cgroup_may_write(dst_cgrp, sb);
+	if (ret)
+		goto err;
+
+	ret = cgroup_attach_permissions(cset->dfl_cgrp, dst_cgrp, sb,
+					!(kargs->flags & CLONE_THREAD),
+					current->nsproxy->cgroup_ns);
+	if (ret)
+		goto err;
+
+	kargs->cset = find_css_set(cset, dst_cgrp);
+	if (!kargs->cset) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	put_css_set(cset);
+	fput(f);
+	kargs->cgrp = dst_cgrp;
+	return ret;
+
+err:
+	cgroup_threadgroup_change_end(current);
+	mutex_unlock(&cgroup_mutex);
+	if (f)
+		fput(f);
+	if (dst_cgrp)
+		cgroup_put(dst_cgrp);
+	put_css_set(cset);
+	if (kargs->cset)
+		put_css_set(kargs->cset);
+	return ret;
+}
+
+/**
+ * cgroup_css_set_put_fork - drop references we took during fork
+ * @kargs: the arguments passed to create the child process
+ *
+ * Drop references to the prepared css_set and target cgroup if
+ * CLONE_INTO_CGROUP was requested.
+ */
+static void cgroup_css_set_put_fork(struct kernel_clone_args *kargs)
+	__releases(&cgroup_threadgroup_rwsem) __releases(&cgroup_mutex)
+{
+	cgroup_threadgroup_change_end(current);
+
+	if (kargs->flags & CLONE_INTO_CGROUP) {
+		struct cgroup *cgrp = kargs->cgrp;
+		struct css_set *cset = kargs->cset;
+
+		mutex_unlock(&cgroup_mutex);
+
+		if (cset) {
+			put_css_set(cset);
+			kargs->cset = NULL;
+		}
+
+		if (cgrp) {
+			cgroup_put(cgrp);
+			kargs->cgrp = NULL;
+		}
+	}
+}
+
 /**
  * cgroup_can_fork - called on a new task before the process is exposed
- * @child: the task in question.
+ * @child: the child process
  *
- * This calls the subsystem can_fork() callbacks. If the can_fork() callback
- * returns an error, the fork aborts with that error code. This allows for
- * a cgroup subsystem to conditionally allow or deny new forks.
+ * This prepares a new css_set for the child process which the child will
+ * be attached to in cgroup_post_fork().
+ * This calls the subsystem can_fork() callbacks. If the cgroup_can_fork()
+ * callback returns an error, the fork aborts with that error code. This
+ * allows for a cgroup subsystem to conditionally allow or deny new forks.
  */
-int cgroup_can_fork(struct task_struct *child)
+int cgroup_can_fork(struct task_struct *child, struct kernel_clone_args *kargs)
 {
 	struct cgroup_subsys *ss;
 	int i, j, ret;
 
+	ret = cgroup_css_set_fork(kargs);
+	if (ret)
+		return ret;
+
 	do_each_subsys_mask(ss, i, have_canfork_callback) {
-		ret = ss->can_fork(child);
+		ret = ss->can_fork(child, kargs->cset);
 		if (ret)
 			goto out_revert;
 	} while_each_subsys_mask();
@@ -5976,98 +6125,87 @@
 		if (j >= i)
 			break;
 		if (ss->cancel_fork)
-			ss->cancel_fork(child);
+			ss->cancel_fork(child, kargs->cset);
 	}
 
+	cgroup_css_set_put_fork(kargs);
+
 	return ret;
 }
 
 /**
  * cgroup_cancel_fork - called if a fork failed after cgroup_can_fork()
- * @child: the task in question
+ * @child: the child process
+ * @kargs: the arguments passed to create the child process
  *
  * This calls the cancel_fork() callbacks if a fork failed *after*
- * cgroup_can_fork() succeded.
+ * cgroup_can_fork() succeded and cleans up references we took to
+ * prepare a new css_set for the child process in cgroup_can_fork().
  */
-void cgroup_cancel_fork(struct task_struct *child)
+void cgroup_cancel_fork(struct task_struct *child,
+			struct kernel_clone_args *kargs)
 {
 	struct cgroup_subsys *ss;
 	int i;
 
 	for_each_subsys(ss, i)
 		if (ss->cancel_fork)
-			ss->cancel_fork(child);
+			ss->cancel_fork(child, kargs->cset);
+
+	cgroup_css_set_put_fork(kargs);
 }
 
 /**
- * cgroup_post_fork - called on a new task after adding it to the task list
- * @child: the task in question
+ * cgroup_post_fork - finalize cgroup setup for the child process
+ * @child: the child process
  *
- * Adds the task to the list running through its css_set if necessary and
- * call the subsystem fork() callbacks.  Has to be after the task is
- * visible on the task list in case we race with the first call to
- * cgroup_task_iter_start() - to guarantee that the new task ends up on its
- * list.
+ * Attach the child process to its css_set calling the subsystem fork()
+ * callbacks.
  */
-void cgroup_post_fork(struct task_struct *child)
+void cgroup_post_fork(struct task_struct *child,
+		      struct kernel_clone_args *kargs)
+	__releases(&cgroup_threadgroup_rwsem) __releases(&cgroup_mutex)
 {
 	struct cgroup_subsys *ss;
+	struct css_set *cset;
 	int i;
 
-	/*
-	 * This may race against cgroup_enable_task_cg_lists().  As that
-	 * function sets use_task_css_set_links before grabbing
-	 * tasklist_lock and we just went through tasklist_lock to add
-	 * @child, it's guaranteed that either we see the set
-	 * use_task_css_set_links or cgroup_enable_task_cg_lists() sees
-	 * @child during its iteration.
-	 *
-	 * If we won the race, @child is associated with %current's
-	 * css_set.  Grabbing css_set_lock guarantees both that the
-	 * association is stable, and, on completion of the parent's
-	 * migration, @child is visible in the source of migration or
-	 * already in the destination cgroup.  This guarantee is necessary
-	 * when implementing operations which need to migrate all tasks of
-	 * a cgroup to another.
-	 *
-	 * Note that if we lose to cgroup_enable_task_cg_lists(), @child
-	 * will remain in init_css_set.  This is safe because all tasks are
-	 * in the init_css_set before cg_links is enabled and there's no
-	 * operation which transfers all tasks out of init_css_set.
-	 */
-	if (use_task_css_set_links) {
-		struct css_set *cset;
+	cset = kargs->cset;
+	kargs->cset = NULL;
 
-		spin_lock_irq(&css_set_lock);
-		cset = task_css_set(current);
-		if (list_empty(&child->cg_list)) {
-			get_css_set(cset);
-			cset->nr_tasks++;
-			css_set_move_task(child, NULL, cset, false);
-		}
+	spin_lock_irq(&css_set_lock);
+
+	/* init tasks are special, only link regular threads */
+	if (likely(child->pid)) {
+		WARN_ON_ONCE(!list_empty(&child->cg_list));
+		cset->nr_tasks++;
+		css_set_move_task(child, NULL, cset, false);
+	} else {
+		put_css_set(cset);
+		cset = NULL;
+	}
+
+	/*
+	 * If the cgroup has to be frozen, the new task has too.  Let's set
+	 * the JOBCTL_TRAP_FREEZE jobctl bit to get the task into the
+	 * frozen state.
+	 */
+	if (unlikely(cgroup_task_freeze(child))) {
+		spin_lock(&child->sighand->siglock);
+		WARN_ON_ONCE(child->frozen);
+		child->jobctl |= JOBCTL_TRAP_FREEZE;
+		spin_unlock(&child->sighand->siglock);
 
 		/*
-		 * If the cgroup has to be frozen, the new task has too.
-		 * Let's set the JOBCTL_TRAP_FREEZE jobctl bit to get
-		 * the task into the frozen state.
+		 * Calling cgroup_update_frozen() isn't required here,
+		 * because it will be called anyway a bit later from
+		 * do_freezer_trap(). So we avoid cgroup's transient switch
+		 * from the frozen state and back.
 		 */
-		if (unlikely(cgroup_task_freeze(child))) {
-			spin_lock(&child->sighand->siglock);
-			WARN_ON_ONCE(child->frozen);
-			child->jobctl |= JOBCTL_TRAP_FREEZE;
-			spin_unlock(&child->sighand->siglock);
-
-			/*
-			 * Calling cgroup_update_frozen() isn't required here,
-			 * because it will be called anyway a bit later
-			 * from do_freezer_trap(). So we avoid cgroup's
-			 * transient switch from the frozen state and back.
-			 */
-		}
-
-		spin_unlock_irq(&css_set_lock);
 	}
 
+	spin_unlock_irq(&css_set_lock);
+
 	/*
 	 * Call ss->fork().  This must happen after @child is linked on
 	 * css_set; otherwise, @child might change state between ->fork()
@@ -6076,26 +6214,25 @@
 	do_each_subsys_mask(ss, i, have_fork_callback) {
 		ss->fork(child);
 	} while_each_subsys_mask();
+
+	/* Make the new cset the root_cset of the new cgroup namespace. */
+	if (kargs->flags & CLONE_NEWCGROUP) {
+		struct css_set *rcset = child->nsproxy->cgroup_ns->root_cset;
+
+		get_css_set(cset);
+		child->nsproxy->cgroup_ns->root_cset = cset;
+		put_css_set(rcset);
+	}
+
+	cgroup_css_set_put_fork(kargs);
 }
 
 /**
  * cgroup_exit - detach cgroup from exiting task
  * @tsk: pointer to task_struct of exiting process
  *
- * Description: Detach cgroup from @tsk and release it.
+ * Description: Detach cgroup from @tsk.
  *
- * Note that cgroups marked notify_on_release force every task in
- * them to take the global cgroup_mutex mutex when exiting.
- * This could impact scaling on very large systems.  Be reluctant to
- * use notify_on_release cgroups where very high task exit scaling
- * is required on large systems.
- *
- * We set the exiting tasks cgroup to the root cgroup (top_cgroup).  We
- * call cgroup_exit() while the task is still competent to handle
- * notify_on_release(), then leave the task attached to the root cgroup in
- * each hierarchy for the remainder of its exit.  No need to bother with
- * init_css_set refcnting.  init_css_set never goes away and we can't race
- * with migration path - PF_EXITING is visible to migration path.
  */
 void cgroup_exit(struct task_struct *tsk)
 {
@@ -6103,26 +6240,19 @@
 	struct css_set *cset;
 	int i;
 
-	/*
-	 * Unlink from @tsk from its css_set.  As migration path can't race
-	 * with us, we can check css_set and cg_list without synchronization.
-	 */
+	spin_lock_irq(&css_set_lock);
+
+	WARN_ON_ONCE(list_empty(&tsk->cg_list));
 	cset = task_css_set(tsk);
+	css_set_move_task(tsk, cset, NULL, false);
+	list_add_tail(&tsk->cg_list, &cset->dying_tasks);
+	cset->nr_tasks--;
 
-	if (!list_empty(&tsk->cg_list)) {
-		spin_lock_irq(&css_set_lock);
-		css_set_move_task(tsk, cset, NULL, false);
-		list_add_tail(&tsk->cg_list, &cset->dying_tasks);
-		cset->nr_tasks--;
+	WARN_ON_ONCE(cgroup_task_frozen(tsk));
+	if (unlikely(cgroup_task_freeze(tsk)))
+		cgroup_update_frozen(task_dfl_cgroup(tsk));
 
-		WARN_ON_ONCE(cgroup_task_frozen(tsk));
-		if (unlikely(cgroup_task_freeze(tsk)))
-			cgroup_update_frozen(task_dfl_cgroup(tsk));
-
-		spin_unlock_irq(&css_set_lock);
-	} else {
-		get_css_set(cset);
-	}
+	spin_unlock_irq(&css_set_lock);
 
 	/* see cgroup_post_fork() for details */
 	do_each_subsys_mask(ss, i, have_exit_callback) {
@@ -6139,12 +6269,10 @@
 		ss->release(task);
 	} while_each_subsys_mask();
 
-	if (use_task_css_set_links) {
-		spin_lock_irq(&css_set_lock);
-		css_set_skip_task_iters(task_css_set(task), task);
-		list_del_init(&task->cg_list);
-		spin_unlock_irq(&css_set_lock);
-	}
+	spin_lock_irq(&css_set_lock);
+	css_set_skip_task_iters(task_css_set(task), task);
+	list_del_init(&task->cg_list);
+	spin_unlock_irq(&css_set_lock);
 }
 
 void cgroup_free(struct task_struct *task)
@@ -6286,7 +6414,6 @@
  */
 struct cgroup *cgroup_get_from_fd(int fd)
 {
-	struct cgroup_subsys_state *css;
 	struct cgroup *cgrp;
 	struct file *f;
 
@@ -6294,17 +6421,8 @@
 	if (!f)
 		return ERR_PTR(-EBADF);
 
-	css = css_tryget_online_from_dir(f->f_path.dentry, NULL);
+	cgrp = cgroup_get_from_file(f);
 	fput(f);
-	if (IS_ERR(css))
-		return ERR_CAST(css);
-
-	cgrp = css->cgroup;
-	if (!cgroup_on_dfl(cgrp)) {
-		cgroup_put(cgrp);
-		return ERR_PTR(-EBADF);
-	}
-
 	return cgrp;
 }
 EXPORT_SYMBOL_GPL(cgroup_get_from_fd);
@@ -6432,26 +6550,31 @@
 #endif	/* CONFIG_SOCK_CGROUP_DATA */
 
 #ifdef CONFIG_CGROUP_BPF
-int cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
-		      enum bpf_attach_type type, u32 flags)
+int cgroup_bpf_attach(struct cgroup *cgrp,
+		      struct bpf_prog *prog, struct bpf_prog *replace_prog,
+		      struct bpf_cgroup_link *link,
+		      enum bpf_attach_type type,
+		      u32 flags)
 {
 	int ret;
 
 	mutex_lock(&cgroup_mutex);
-	ret = __cgroup_bpf_attach(cgrp, prog, type, flags);
+	ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags);
 	mutex_unlock(&cgroup_mutex);
 	return ret;
 }
+
 int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
-		      enum bpf_attach_type type, u32 flags)
+		      enum bpf_attach_type type)
 {
 	int ret;
 
 	mutex_lock(&cgroup_mutex);
-	ret = __cgroup_bpf_detach(cgrp, prog, type);
+	ret = __cgroup_bpf_detach(cgrp, prog, NULL, type);
 	mutex_unlock(&cgroup_mutex);
 	return ret;
 }
+
 int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
 		     union bpf_attr __user *uattr)
 {
@@ -6509,7 +6632,10 @@
 static ssize_t features_show(struct kobject *kobj, struct kobj_attribute *attr,
 			     char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "nsdelegate\nmemory_localevents\n");
+	return snprintf(buf, PAGE_SIZE,
+			"nsdelegate\n"
+			"memory_localevents\n"
+			"memory_recursiveprot\n");
 }
 static struct kobj_attribute cgroup_features_attr = __ATTR_RO(features);
 
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index badfa8f..0aa224c 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -358,8 +358,12 @@
 static DECLARE_WAIT_QUEUE_HEAD(cpuset_attach_wq);
 
 /*
- * Cgroup v2 behavior is used when on default hierarchy or the
- * cgroup_v2_mode flag is set.
+ * Cgroup v2 behavior is used on the "cpus" and "mems" control files when
+ * on default hierarchy or when the cpuset_v2_mode flag is set by mounting
+ * the v1 cpuset cgroup filesystem with the "cpuset_v2_mode" mount option.
+ * With v2 behavior, "cpus" and "mems" are always what the users have
+ * requested and won't be changed by hotplug events. Only the effective
+ * cpus or mems will be affected.
  */
 static inline bool is_in_v2_mode(void)
 {
@@ -386,7 +390,7 @@
 			 * The top cpuset doesn't have any online cpu as a
 			 * consequence of a race between cpuset_hotplug_work
 			 * and cpu hotplug notifier.  But we know the top
-			 * cpuset's effective_cpus is on its way to to be
+			 * cpuset's effective_cpus is on its way to be
 			 * identical to cpu_online_mask.
 			 */
 			cpumask_copy(pmask, cpu_online_mask);
@@ -929,8 +933,6 @@
 	lockdep_assert_cpus_held();
 	lockdep_assert_held(&sched_domains_mutex);
 
-	cgroup_enable_task_cg_lists();
-
 	rcu_read_lock();
 
 	/*
@@ -1112,7 +1114,7 @@
  * cpus_allowed can be granted or an error code will be returned.
  *
  * For partcmd_disable, the cpuset is being transofrmed from a partition
- * root back to a non-partition root. any CPUs in cpus_allowed that are in
+ * root back to a non-partition root. Any CPUs in cpus_allowed that are in
  * parent's subparts_cpus will be taken away from that cpumask and put back
  * into parent's effective_cpus. 0 should always be returned.
  *
@@ -1146,6 +1148,7 @@
 	struct cpuset *parent = parent_cs(cpuset);
 	int adding;	/* Moving cpus from effective_cpus to subparts_cpus */
 	int deleting;	/* Moving cpus from subparts_cpus to effective_cpus */
+	int new_prs;
 	bool part_error = false;	/* Partition error? */
 
 	percpu_rwsem_assert_held(&cpuset_rwsem);
@@ -1181,6 +1184,7 @@
 	 * A cpumask update cannot make parent's effective_cpus become empty.
 	 */
 	adding = deleting = false;
+	new_prs = cpuset->partition_root_state;
 	if (cmd == partcmd_enable) {
 		cpumask_copy(tmp->addmask, cpuset->cpus_allowed);
 		adding = true;
@@ -1223,7 +1227,7 @@
 		/*
 		 * partcmd_update w/o newmask:
 		 *
-		 * addmask = cpus_allowed & parent->effectiveb_cpus
+		 * addmask = cpus_allowed & parent->effective_cpus
 		 *
 		 * Note that parent's subparts_cpus may have been
 		 * pre-shrunk in case there is a change in the cpu list.
@@ -1245,11 +1249,11 @@
 		switch (cpuset->partition_root_state) {
 		case PRS_ENABLED:
 			if (part_error)
-				cpuset->partition_root_state = PRS_ERROR;
+				new_prs = PRS_ERROR;
 			break;
 		case PRS_ERROR:
 			if (!part_error)
-				cpuset->partition_root_state = PRS_ENABLED;
+				new_prs = PRS_ENABLED;
 			break;
 		}
 		/*
@@ -1258,10 +1262,10 @@
 		part_error = (prev_prs == PRS_ERROR);
 	}
 
-	if (!part_error && (cpuset->partition_root_state == PRS_ERROR))
+	if (!part_error && (new_prs == PRS_ERROR))
 		return 0;	/* Nothing need to be done */
 
-	if (cpuset->partition_root_state == PRS_ERROR) {
+	if (new_prs == PRS_ERROR) {
 		/*
 		 * Remove all its cpus from parent's subparts_cpus.
 		 */
@@ -1270,7 +1274,7 @@
 				       parent->subparts_cpus);
 	}
 
-	if (!adding && !deleting)
+	if (!adding && !deleting && (new_prs == cpuset->partition_root_state))
 		return 0;
 
 	/*
@@ -1297,6 +1301,9 @@
 	}
 
 	parent->nr_subparts_cpus = cpumask_weight(parent->subparts_cpus);
+
+	if (cpuset->partition_root_state != new_prs)
+		cpuset->partition_root_state = new_prs;
 	spin_unlock_irq(&callback_lock);
 
 	return cmd == partcmd_update;
@@ -1319,6 +1326,7 @@
 	struct cpuset *cp;
 	struct cgroup_subsys_state *pos_css;
 	bool need_rebuild_sched_domains = false;
+	int new_prs;
 
 	rcu_read_lock();
 	cpuset_for_each_descendant_pre(cp, pos_css, cs) {
@@ -1358,17 +1366,18 @@
 		 * update_tasks_cpumask() again for tasks in the parent
 		 * cpuset if the parent's subparts_cpus changes.
 		 */
-		if ((cp != cs) && cp->partition_root_state) {
+		new_prs = cp->partition_root_state;
+		if ((cp != cs) && new_prs) {
 			switch (parent->partition_root_state) {
 			case PRS_DISABLED:
 				/*
 				 * If parent is not a partition root or an
-				 * invalid partition root, clear the state
-				 * state and the CS_CPU_EXCLUSIVE flag.
+				 * invalid partition root, clear its state
+				 * and its CS_CPU_EXCLUSIVE flag.
 				 */
 				WARN_ON_ONCE(cp->partition_root_state
 					     != PRS_ERROR);
-				cp->partition_root_state = 0;
+				new_prs = PRS_DISABLED;
 
 				/*
 				 * clear_bit() is an atomic operation and
@@ -1389,11 +1398,7 @@
 				/*
 				 * When parent is invalid, it has to be too.
 				 */
-				cp->partition_root_state = PRS_ERROR;
-				if (cp->nr_subparts_cpus) {
-					cp->nr_subparts_cpus = 0;
-					cpumask_clear(cp->subparts_cpus);
-				}
+				new_prs = PRS_ERROR;
 				break;
 			}
 		}
@@ -1405,8 +1410,7 @@
 		spin_lock_irq(&callback_lock);
 
 		cpumask_copy(cp->effective_cpus, tmp->new_cpus);
-		if (cp->nr_subparts_cpus &&
-		   (cp->partition_root_state != PRS_ENABLED)) {
+		if (cp->nr_subparts_cpus && (new_prs != PRS_ENABLED)) {
 			cp->nr_subparts_cpus = 0;
 			cpumask_clear(cp->subparts_cpus);
 		} else if (cp->nr_subparts_cpus) {
@@ -1433,6 +1437,10 @@
 					= cpumask_weight(cp->subparts_cpus);
 			}
 		}
+
+		if (new_prs != cp->partition_root_state)
+			cp->partition_root_state = new_prs;
+
 		spin_unlock_irq(&callback_lock);
 
 		WARN_ON(!is_in_v2_mode() &&
@@ -1473,10 +1481,15 @@
 	struct cpuset *sibling;
 	struct cgroup_subsys_state *pos_css;
 
+	percpu_rwsem_assert_held(&cpuset_rwsem);
+
 	/*
 	 * Check all its siblings and call update_cpumasks_hier()
 	 * if their use_parent_ecpus flag is set in order for them
 	 * to use the right effective_cpus value.
+	 *
+	 * The update_cpumasks_hier() function may sleep. So we have to
+	 * release the RCU read lock before calling it.
 	 */
 	rcu_read_lock();
 	cpuset_for_each_child(sibling, pos_css, parent) {
@@ -1484,8 +1497,13 @@
 			continue;
 		if (!sibling->use_parent_ecpus)
 			continue;
+		if (!css_tryget_online(&sibling->css))
+			continue;
 
+		rcu_read_unlock();
 		update_cpumasks_hier(sibling, tmp);
+		rcu_read_lock();
+		css_put(&sibling->css);
 	}
 	rcu_read_unlock();
 }
@@ -1558,8 +1576,7 @@
 	 * Make sure that subparts_cpus is a subset of cpus_allowed.
 	 */
 	if (cs->nr_subparts_cpus) {
-		cpumask_andnot(cs->subparts_cpus, cs->subparts_cpus,
-			       cs->cpus_allowed);
+		cpumask_and(cs->subparts_cpus, cs->subparts_cpus, cs->cpus_allowed);
 		cs->nr_subparts_cpus = cpumask_weight(cs->subparts_cpus);
 	}
 	spin_unlock_irq(&callback_lock);
@@ -1676,7 +1693,7 @@
 	guarantee_online_mems(cs, &newmems);
 
 	/*
-	 * The mpol_rebind_mm() call takes mmap_sem, which we couldn't
+	 * The mpol_rebind_mm() call takes mmap_lock, which we couldn't
 	 * take while holding tasklist_lock.  Forks can happen - the
 	 * mpol_dup() cpuset_being_rebound check will catch such forks,
 	 * and rebind their vma mempolicies too.  Because we still hold
@@ -1781,7 +1798,7 @@
  *
  * Call with cpuset_mutex held. May take callback_lock during call.
  * Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
- * lock each such tasks mm->mmap_sem, scan its vma's and rebind
+ * lock each such tasks mm->mmap_lock, scan its vma's and rebind
  * their mempolicies to the cpusets new mems_allowed.
  */
 static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
@@ -1935,34 +1952,32 @@
 
 /*
  * update_prstate - update partititon_root_state
- * cs:	the cpuset to update
- * val: 0 - disabled, 1 - enabled
+ * cs: the cpuset to update
+ * new_prs: new partition root state
  *
  * Call with cpuset_mutex held.
  */
-static int update_prstate(struct cpuset *cs, int val)
+static int update_prstate(struct cpuset *cs, int new_prs)
 {
-	int err;
+	int err, old_prs = cs->partition_root_state;
 	struct cpuset *parent = parent_cs(cs);
-	struct tmpmasks tmp;
+	struct tmpmasks tmpmask;
 
-	if ((val != 0) && (val != 1))
-		return -EINVAL;
-	if (val == cs->partition_root_state)
+	if (old_prs == new_prs)
 		return 0;
 
 	/*
 	 * Cannot force a partial or invalid partition root to a full
 	 * partition root.
 	 */
-	if (val && cs->partition_root_state)
+	if (new_prs && (old_prs == PRS_ERROR))
 		return -EINVAL;
 
-	if (alloc_cpumasks(NULL, &tmp))
+	if (alloc_cpumasks(NULL, &tmpmask))
 		return -ENOMEM;
 
 	err = -EINVAL;
-	if (!cs->partition_root_state) {
+	if (!old_prs) {
 		/*
 		 * Turning on partition root requires setting the
 		 * CS_CPU_EXCLUSIVE bit implicitly as well and cpus_allowed
@@ -1976,31 +1991,27 @@
 			goto out;
 
 		err = update_parent_subparts_cpumask(cs, partcmd_enable,
-						     NULL, &tmp);
+						     NULL, &tmpmask);
 		if (err) {
 			update_flag(CS_CPU_EXCLUSIVE, cs, 0);
 			goto out;
 		}
-		cs->partition_root_state = PRS_ENABLED;
 	} else {
 		/*
 		 * Turning off partition root will clear the
 		 * CS_CPU_EXCLUSIVE bit.
 		 */
-		if (cs->partition_root_state == PRS_ERROR) {
-			cs->partition_root_state = 0;
+		if (old_prs == PRS_ERROR) {
 			update_flag(CS_CPU_EXCLUSIVE, cs, 0);
 			err = 0;
 			goto out;
 		}
 
 		err = update_parent_subparts_cpumask(cs, partcmd_disable,
-						     NULL, &tmp);
+						     NULL, &tmpmask);
 		if (err)
 			goto out;
 
-		cs->partition_root_state = 0;
-
 		/* Turning off CS_CPU_EXCLUSIVE will not return error */
 		update_flag(CS_CPU_EXCLUSIVE, cs, 0);
 	}
@@ -2013,11 +2024,17 @@
 		update_tasks_cpumask(parent);
 
 	if (parent->child_ecpus_count)
-		update_sibling_cpumasks(parent, cs, &tmp);
+		update_sibling_cpumasks(parent, cs, &tmpmask);
 
 	rebuild_sched_domains_locked();
 out:
-	free_cpumasks(NULL, &tmp);
+	if (!err) {
+		spin_lock_irq(&callback_lock);
+		cs->partition_root_state = new_prs;
+		spin_unlock_irq(&callback_lock);
+	}
+
+	free_cpumasks(NULL, &tmpmask);
 	return err;
 }
 
@@ -2195,6 +2212,7 @@
 	cgroup_taskset_first(tset, &css);
 	cs = css_cs(css);
 
+	cpus_read_lock();
 	percpu_down_write(&cpuset_rwsem);
 
 	/* prepare for attach */
@@ -2250,6 +2268,7 @@
 		wake_up(&cpuset_attach_wq);
 
 	percpu_up_write(&cpuset_rwsem);
+	cpus_read_unlock();
 }
 
 /* The various types of files and directories in a cpuset file system */
@@ -3058,7 +3077,7 @@
 		goto retry;
 	}
 
-	parent =  parent_cs(cs);
+	parent = parent_cs(cs);
 	compute_effective_cpumask(&new_cpus, cs, parent);
 	nodes_and(new_mems, cs->mems_allowed, parent->effective_mems);
 
@@ -3080,8 +3099,10 @@
 	if (is_partition_root(cs) && (cpumask_empty(&new_cpus) ||
 	   (parent->partition_root_state == PRS_ERROR))) {
 		if (cs->nr_subparts_cpus) {
+			spin_lock_irq(&callback_lock);
 			cs->nr_subparts_cpus = 0;
 			cpumask_clear(cs->subparts_cpus);
+			spin_unlock_irq(&callback_lock);
 			compute_effective_cpumask(&new_cpus, cs, parent);
 		}
 
@@ -3095,7 +3116,9 @@
 		     cpumask_empty(&new_cpus)) {
 			update_parent_subparts_cpumask(cs, partcmd_disable,
 						       NULL, tmp);
+			spin_lock_irq(&callback_lock);
 			cs->partition_root_state = PRS_ERROR;
+			spin_unlock_irq(&callback_lock);
 		}
 		cpuset_force_rebuild();
 	}
diff --git a/kernel/cgroup/namespace.c b/kernel/cgroup/namespace.c
index b05f1dd..812a61a 100644
--- a/kernel/cgroup/namespace.c
+++ b/kernel/cgroup/namespace.c
@@ -95,11 +95,12 @@
 	return container_of(ns, struct cgroup_namespace, ns);
 }
 
-static int cgroupns_install(struct nsproxy *nsproxy, struct ns_common *ns)
+static int cgroupns_install(struct nsset *nsset, struct ns_common *ns)
 {
+	struct nsproxy *nsproxy = nsset->nsproxy;
 	struct cgroup_namespace *cgroup_ns = to_cg_ns(ns);
 
-	if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) ||
+	if (!ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN) ||
 	    !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN))
 		return -EPERM;
 
diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c
index 138059e..511af87 100644
--- a/kernel/cgroup/pids.c
+++ b/kernel/cgroup/pids.c
@@ -33,6 +33,7 @@
 #include <linux/atomic.h>
 #include <linux/cgroup.h>
 #include <linux/slab.h>
+#include <linux/sched/task.h>
 
 #define PIDS_MAX (PID_MAX_LIMIT + 1ULL)
 #define PIDS_MAX_STR "max"
@@ -214,13 +215,16 @@
  * task_css_check(true) in pids_can_fork() and pids_cancel_fork() relies
  * on cgroup_threadgroup_change_begin() held by the copy_process().
  */
-static int pids_can_fork(struct task_struct *task)
+static int pids_can_fork(struct task_struct *task, struct css_set *cset)
 {
 	struct cgroup_subsys_state *css;
 	struct pids_cgroup *pids;
 	int err;
 
-	css = task_css_check(current, pids_cgrp_id, true);
+	if (cset)
+		css = cset->subsys[pids_cgrp_id];
+	else
+		css = task_css_check(current, pids_cgrp_id, true);
 	pids = css_pids(css);
 	err = pids_try_charge(pids, 1);
 	if (err) {
@@ -235,12 +239,15 @@
 	return err;
 }
 
-static void pids_cancel_fork(struct task_struct *task)
+static void pids_cancel_fork(struct task_struct *task, struct css_set *cset)
 {
 	struct cgroup_subsys_state *css;
 	struct pids_cgroup *pids;
 
-	css = task_css_check(current, pids_cgrp_id, true);
+	if (cset)
+		css = cset->subsys[pids_cgrp_id];
+	else
+		css = task_css_check(current, pids_cgrp_id, true);
 	pids = css_pids(css);
 	pids_uncharge(pids, 1);
 }
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index 4a942d4..89ca9b6 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -64,7 +64,6 @@
 
 	raw_spin_unlock_irqrestore(cpu_lock, flags);
 }
-EXPORT_SYMBOL_GPL(cgroup_rstat_updated);
 
 /**
  * cgroup_rstat_cpu_pop_updated - iterate and dismantle rstat_cpu updated tree
@@ -294,44 +293,48 @@
  * Functions for cgroup basic resource statistics implemented on top of
  * rstat.
  */
-static void cgroup_base_stat_accumulate(struct cgroup_base_stat *dst_bstat,
-					struct cgroup_base_stat *src_bstat)
+static void cgroup_base_stat_add(struct cgroup_base_stat *dst_bstat,
+				 struct cgroup_base_stat *src_bstat)
 {
 	dst_bstat->cputime.utime += src_bstat->cputime.utime;
 	dst_bstat->cputime.stime += src_bstat->cputime.stime;
 	dst_bstat->cputime.sum_exec_runtime += src_bstat->cputime.sum_exec_runtime;
 }
 
+static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat,
+				 struct cgroup_base_stat *src_bstat)
+{
+	dst_bstat->cputime.utime -= src_bstat->cputime.utime;
+	dst_bstat->cputime.stime -= src_bstat->cputime.stime;
+	dst_bstat->cputime.sum_exec_runtime -= src_bstat->cputime.sum_exec_runtime;
+}
+
 static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu)
 {
 	struct cgroup *parent = cgroup_parent(cgrp);
 	struct cgroup_rstat_cpu *rstatc = cgroup_rstat_cpu(cgrp, cpu);
-	struct task_cputime *last_cputime = &rstatc->last_bstat.cputime;
-	struct task_cputime cputime;
-	struct cgroup_base_stat delta;
+	struct cgroup_base_stat cur, delta;
 	unsigned seq;
 
 	/* fetch the current per-cpu values */
 	do {
 		seq = __u64_stats_fetch_begin(&rstatc->bsync);
-		cputime = rstatc->bstat.cputime;
+		cur.cputime = rstatc->bstat.cputime;
 	} while (__u64_stats_fetch_retry(&rstatc->bsync, seq));
 
-	/* calculate the delta to propgate */
-	delta.cputime.utime = cputime.utime - last_cputime->utime;
-	delta.cputime.stime = cputime.stime - last_cputime->stime;
-	delta.cputime.sum_exec_runtime = cputime.sum_exec_runtime -
-					 last_cputime->sum_exec_runtime;
-	*last_cputime = cputime;
+	/* propagate percpu delta to global */
+	delta = cur;
+	cgroup_base_stat_sub(&delta, &rstatc->last_bstat);
+	cgroup_base_stat_add(&cgrp->bstat, &delta);
+	cgroup_base_stat_add(&rstatc->last_bstat, &delta);
 
-	/* transfer the pending stat into delta */
-	cgroup_base_stat_accumulate(&delta, &cgrp->pending_bstat);
-	memset(&cgrp->pending_bstat, 0, sizeof(cgrp->pending_bstat));
-
-	/* propagate delta into the global stat and the parent's pending */
-	cgroup_base_stat_accumulate(&cgrp->bstat, &delta);
-	if (parent)
-		cgroup_base_stat_accumulate(&parent->pending_bstat, &delta);
+	/* propagate global delta to parent */
+	if (parent) {
+		delta = cgrp->bstat;
+		cgroup_base_stat_sub(&delta, &cgrp->last_bstat);
+		cgroup_base_stat_add(&parent->bstat, &delta);
+		cgroup_base_stat_add(&cgrp->last_bstat, &delta);
+	}
 }
 
 static struct cgroup_rstat_cpu *
@@ -385,18 +388,60 @@
 	cgroup_base_stat_cputime_account_end(cgrp, rstatc);
 }
 
+/*
+ * compute the cputime for the root cgroup by getting the per cpu data
+ * at a global level, then categorizing the fields in a manner consistent
+ * with how it is done by __cgroup_account_cputime_field for each bit of
+ * cpu time attributed to a cgroup.
+ */
+static void root_cgroup_cputime(struct task_cputime *cputime)
+{
+	int i;
+
+	cputime->stime = 0;
+	cputime->utime = 0;
+	cputime->sum_exec_runtime = 0;
+	for_each_possible_cpu(i) {
+		struct kernel_cpustat kcpustat;
+		u64 *cpustat = kcpustat.cpustat;
+		u64 user = 0;
+		u64 sys = 0;
+
+		kcpustat_cpu_fetch(&kcpustat, i);
+
+		user += cpustat[CPUTIME_USER];
+		user += cpustat[CPUTIME_NICE];
+		cputime->utime += user;
+
+		sys += cpustat[CPUTIME_SYSTEM];
+		sys += cpustat[CPUTIME_IRQ];
+		sys += cpustat[CPUTIME_SOFTIRQ];
+		cputime->stime += sys;
+
+		cputime->sum_exec_runtime += user;
+		cputime->sum_exec_runtime += sys;
+		cputime->sum_exec_runtime += cpustat[CPUTIME_STEAL];
+	}
+}
+
 void cgroup_base_stat_cputime_show(struct seq_file *seq)
 {
 	struct cgroup *cgrp = seq_css(seq)->cgroup;
 	u64 usage, utime, stime;
+	struct task_cputime cputime;
 
-	if (!cgroup_parent(cgrp))
-		return;
-
-	cgroup_rstat_flush_hold(cgrp);
-	usage = cgrp->bstat.cputime.sum_exec_runtime;
-	cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime, &utime, &stime);
-	cgroup_rstat_flush_release();
+	if (cgroup_parent(cgrp)) {
+		cgroup_rstat_flush_hold(cgrp);
+		usage = cgrp->bstat.cputime.sum_exec_runtime;
+		cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime,
+			       &utime, &stime);
+		cgroup_rstat_flush_release();
+	} else {
+		root_cgroup_cputime(&cputime);
+		usage = cputime.sum_exec_runtime;
+		utime = cputime.utime;
+		stime = cputime.stime;
+	}
 
 	do_div(usage, NSEC_PER_USEC);
 	do_div(utime, NSEC_PER_USEC);
diff --git a/kernel/compat.c b/kernel/compat.c
index a2bc1d6..05adfd6 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -26,94 +26,6 @@
 
 #include <linux/uaccess.h>
 
-static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv)
-{
-	return (!access_ok(ctv, sizeof(*ctv)) ||
-			__get_user(tv->tv_sec, &ctv->tv_sec) ||
-			__get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
-}
-
-static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv)
-{
-	return (!access_ok(ctv, sizeof(*ctv)) ||
-			__put_user(tv->tv_sec, &ctv->tv_sec) ||
-			__put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
-}
-
-static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts)
-{
-	return (!access_ok(cts, sizeof(*cts)) ||
-			__get_user(ts->tv_sec, &cts->tv_sec) ||
-			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
-}
-
-static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts)
-{
-	return (!access_ok(cts, sizeof(*cts)) ||
-			__put_user(ts->tv_sec, &cts->tv_sec) ||
-			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
-}
-
-int compat_get_timeval(struct timeval *tv, const void __user *utv)
-{
-	if (COMPAT_USE_64BIT_TIME)
-		return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
-	else
-		return __compat_get_timeval(tv, utv);
-}
-EXPORT_SYMBOL_GPL(compat_get_timeval);
-
-int compat_put_timeval(const struct timeval *tv, void __user *utv)
-{
-	if (COMPAT_USE_64BIT_TIME)
-		return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
-	else
-		return __compat_put_timeval(tv, utv);
-}
-EXPORT_SYMBOL_GPL(compat_put_timeval);
-
-int compat_get_timespec(struct timespec *ts, const void __user *uts)
-{
-	if (COMPAT_USE_64BIT_TIME)
-		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
-	else
-		return __compat_get_timespec(ts, uts);
-}
-EXPORT_SYMBOL_GPL(compat_get_timespec);
-
-int compat_put_timespec(const struct timespec *ts, void __user *uts)
-{
-	if (COMPAT_USE_64BIT_TIME)
-		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
-	else
-		return __compat_put_timespec(ts, uts);
-}
-EXPORT_SYMBOL_GPL(compat_put_timespec);
-
-int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i)
-{
-	struct compat_itimerval v32;
-
-	if (copy_from_user(&v32, i, sizeof(struct compat_itimerval)))
-		return -EFAULT;
-	o->it_interval.tv_sec = v32.it_interval.tv_sec;
-	o->it_interval.tv_usec = v32.it_interval.tv_usec;
-	o->it_value.tv_sec = v32.it_value.tv_sec;
-	o->it_value.tv_usec = v32.it_value.tv_usec;
-	return 0;
-}
-
-int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i)
-{
-	struct compat_itimerval v32;
-
-	v32.it_interval.tv_sec = i->it_interval.tv_sec;
-	v32.it_interval.tv_usec = i->it_interval.tv_usec;
-	v32.it_value.tv_sec = i->it_value.tv_sec;
-	v32.it_value.tv_usec = i->it_value.tv_usec;
-	return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0;
-}
-
 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
 
 /*
@@ -287,7 +199,7 @@
 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
 
-	if (!user_access_begin(umask, bitmap_size / 8))
+	if (!user_read_access_begin(umask, bitmap_size / 8))
 		return -EFAULT;
 
 	while (nr_compat_longs > 1) {
@@ -299,11 +211,11 @@
 	}
 	if (nr_compat_longs)
 		unsafe_get_user(*mask, umask++, Efault);
-	user_access_end();
+	user_read_access_end();
 	return 0;
 
 Efault:
-	user_access_end();
+	user_read_access_end();
 	return -EFAULT;
 }
 
@@ -316,7 +228,7 @@
 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
 
-	if (!user_access_begin(umask, bitmap_size / 8))
+	if (!user_write_access_begin(umask, bitmap_size / 8))
 		return -EFAULT;
 
 	while (nr_compat_longs > 1) {
@@ -327,10 +239,10 @@
 	}
 	if (nr_compat_longs)
 		unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
-	user_access_end();
+	user_write_access_end();
 	return 0;
 Efault:
-	user_access_end();
+	user_write_access_end();
 	return -EFAULT;
 }
 
@@ -343,11 +255,11 @@
 		return -EFAULT;
 	switch (_NSIG_WORDS) {
 	case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
-		/* fall through */
+		fallthrough;
 	case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
-		/* fall through */
+		fallthrough;
 	case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
-		/* fall through */
+		fallthrough;
 	case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
 	}
 #else
diff --git a/kernel/configs.c b/kernel/configs.c
index c09ea4c..a28c79c 100644
--- a/kernel/configs.c
+++ b/kernel/configs.c
@@ -47,10 +47,9 @@
 				       &kernel_config_data);
 }
 
-static const struct file_operations ikconfig_file_ops = {
-	.owner = THIS_MODULE,
-	.read = ikconfig_read_current,
-	.llseek = default_llseek,
+static const struct proc_ops config_gz_proc_ops = {
+	.proc_read	= ikconfig_read_current,
+	.proc_lseek	= default_llseek,
 };
 
 static int __init ikconfig_init(void)
@@ -59,7 +58,7 @@
 
 	/* create the current config file */
 	entry = proc_create("config.gz", S_IFREG | S_IRUGO, NULL,
-			    &ikconfig_file_ops);
+			    &config_gz_proc_ops);
 	if (!entry)
 		return -ENOMEM;
 
diff --git a/kernel/configs/tiny.config b/kernel/configs/tiny.config
index 7fa0c4a..8a44b93 100644
--- a/kernel/configs/tiny.config
+++ b/kernel/configs/tiny.config
@@ -6,7 +6,6 @@
 CONFIG_KERNEL_XZ=y
 # CONFIG_KERNEL_LZO is not set
 # CONFIG_KERNEL_LZ4 is not set
-CONFIG_OPTIMIZE_INLINING=y
 # CONFIG_SLAB is not set
 # CONFIG_SLUB is not set
 CONFIG_SLOB=y
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index be01a4d..36a98c4 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -25,13 +25,13 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/context_tracking.h>
 
-DEFINE_STATIC_KEY_FALSE(context_tracking_enabled);
-EXPORT_SYMBOL_GPL(context_tracking_enabled);
+DEFINE_STATIC_KEY_FALSE(context_tracking_key);
+EXPORT_SYMBOL_GPL(context_tracking_key);
 
 DEFINE_PER_CPU(struct context_tracking, context_tracking);
 EXPORT_SYMBOL_GPL(context_tracking);
 
-static bool context_tracking_recursion_enter(void)
+static noinstr bool context_tracking_recursion_enter(void)
 {
 	int recursion;
 
@@ -45,7 +45,7 @@
 	return false;
 }
 
-static void context_tracking_recursion_exit(void)
+static __always_inline void context_tracking_recursion_exit(void)
 {
 	__this_cpu_dec(context_tracking.recursion);
 }
@@ -59,7 +59,7 @@
  * instructions to execute won't use any RCU read side critical section
  * because this function sets RCU in extended quiescent state.
  */
-void __context_tracking_enter(enum ctx_state state)
+void noinstr __context_tracking_enter(enum ctx_state state)
 {
 	/* Kernel threads aren't supposed to go to userspace */
 	WARN_ON_ONCE(!current->mm);
@@ -77,8 +77,10 @@
 			 * on the tick.
 			 */
 			if (state == CONTEXT_USER) {
+				instrumentation_begin();
 				trace_user_enter(0);
 				vtime_user_enter(current);
+				instrumentation_end();
 			}
 			rcu_user_enter();
 		}
@@ -99,7 +101,6 @@
 	}
 	context_tracking_recursion_exit();
 }
-NOKPROBE_SYMBOL(__context_tracking_enter);
 EXPORT_SYMBOL_GPL(__context_tracking_enter);
 
 void context_tracking_enter(enum ctx_state state)
@@ -142,7 +143,7 @@
  * This call supports re-entrancy. This way it can be called from any exception
  * handler without needing to know if we came from userspace or not.
  */
-void __context_tracking_exit(enum ctx_state state)
+void noinstr __context_tracking_exit(enum ctx_state state)
 {
 	if (!context_tracking_recursion_enter())
 		return;
@@ -155,15 +156,16 @@
 			 */
 			rcu_user_exit();
 			if (state == CONTEXT_USER) {
+				instrumentation_begin();
 				vtime_user_exit(current);
 				trace_user_exit(0);
+				instrumentation_end();
 			}
 		}
 		__this_cpu_write(context_tracking.state, CONTEXT_KERNEL);
 	}
 	context_tracking_recursion_exit();
 }
-NOKPROBE_SYMBOL(__context_tracking_exit);
 EXPORT_SYMBOL_GPL(__context_tracking_exit);
 
 void context_tracking_exit(enum ctx_state state)
@@ -192,17 +194,19 @@
 
 	if (!per_cpu(context_tracking.active, cpu)) {
 		per_cpu(context_tracking.active, cpu) = true;
-		static_branch_inc(&context_tracking_enabled);
+		static_branch_inc(&context_tracking_key);
 	}
 
 	if (initialized)
 		return;
 
+#ifdef CONFIG_HAVE_TIF_NOHZ
 	/*
 	 * Set TIF_NOHZ to init/0 and let it propagate to all tasks through fork
 	 * This assumes that init is the only task at this early boot stage.
 	 */
 	set_tsk_thread_flag(&init_task, TIF_NOHZ);
+#endif
 	WARN_ON_ONCE(!tasklist_empty());
 
 	initialized = true;
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 06c0094..c06ced1 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -31,6 +31,7 @@
 #include <linux/smpboot.h>
 #include <linux/relay.h>
 #include <linux/slab.h>
+#include <linux/scs.h>
 #include <linux/percpu-rwsem.h>
 #include <linux/cpuset.h>
 
@@ -333,12 +334,12 @@
 
 static void lockdep_acquire_cpus_lock(void)
 {
-	rwsem_acquire(&cpu_hotplug_lock.rw_sem.dep_map, 0, 0, _THIS_IP_);
+	rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_);
 }
 
 static void lockdep_release_cpus_lock(void)
 {
-	rwsem_release(&cpu_hotplug_lock.rw_sem.dep_map, 1, _THIS_IP_);
+	rwsem_release(&cpu_hotplug_lock.dep_map, _THIS_IP_);
 }
 
 /*
@@ -434,7 +435,7 @@
 	/*
 	 * On x86 it's required to boot all logical CPUs at least once so
 	 * that the init code can get a chance to set CR4.MCE on each
-	 * CPU. Otherwise, a broadacasted MCE observing CR4.MCE=0b on any
+	 * CPU. Otherwise, a broadcasted MCE observing CR4.MCE=0b on any
 	 * core will shutdown the machine.
 	 */
 	return !cpumask_test_cpu(cpu, &cpus_booted_once_mask);
@@ -552,6 +553,12 @@
 	int ret;
 
 	/*
+	 * Reset stale stack state from the last time this CPU was online.
+	 */
+	scs_task_reset(idle);
+	kasan_unpoison_task_stack(idle);
+
+	/*
 	 * Some architectures have to walk the irq descriptors to
 	 * setup the vector space for the cpu which comes online.
 	 * Prevent irq alloc/free across the bringup.
@@ -1109,7 +1116,7 @@
 	return _cpu_down(cpu, 0, target);
 }
 
-static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
+static int cpu_down(unsigned int cpu, enum cpuhp_state target)
 {
 	int err;
 
@@ -1119,11 +1126,72 @@
 	return err;
 }
 
-int cpu_down(unsigned int cpu)
+/**
+ * cpu_device_down - Bring down a cpu device
+ * @dev: Pointer to the cpu device to offline
+ *
+ * This function is meant to be used by device core cpu subsystem only.
+ *
+ * Other subsystems should use remove_cpu() instead.
+ */
+int cpu_device_down(struct device *dev)
 {
-	return do_cpu_down(cpu, CPUHP_OFFLINE);
+	return cpu_down(dev->id, CPUHP_OFFLINE);
 }
-EXPORT_SYMBOL(cpu_down);
+
+int remove_cpu(unsigned int cpu)
+{
+	int ret;
+
+	lock_device_hotplug();
+	ret = device_offline(get_cpu_device(cpu));
+	unlock_device_hotplug();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(remove_cpu);
+
+void smp_shutdown_nonboot_cpus(unsigned int primary_cpu)
+{
+	unsigned int cpu;
+	int error;
+
+	cpu_maps_update_begin();
+
+	/*
+	 * Make certain the cpu I'm about to reboot on is online.
+	 *
+	 * This is inline to what migrate_to_reboot_cpu() already do.
+	 */
+	if (!cpu_online(primary_cpu))
+		primary_cpu = cpumask_first(cpu_online_mask);
+
+	for_each_online_cpu(cpu) {
+		if (cpu == primary_cpu)
+			continue;
+
+		error = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
+		if (error) {
+			pr_err("Failed to offline CPU%d - error=%d",
+				cpu, error);
+			break;
+		}
+	}
+
+	/*
+	 * Ensure all but the reboot CPU are offline.
+	 */
+	BUG_ON(num_online_cpus() > 1);
+
+	/*
+	 * Make sure the CPUs won't be enabled by someone else after this
+	 * point. Kexec will reboot to a new kernel shortly resetting
+	 * everything along the way.
+	 */
+	cpu_hotplug_disabled++;
+
+	cpu_maps_update_done();
+}
 
 #else
 #define takedown_cpu		NULL
@@ -1192,8 +1260,8 @@
 	}
 
 	/*
-	 * The caller of do_cpu_up might have raced with another
-	 * caller. Ignore it for now.
+	 * The caller of cpu_up() might have raced with another
+	 * caller. Nothing to do.
 	 */
 	if (st->state >= target)
 		goto out;
@@ -1238,7 +1306,7 @@
 	return ret;
 }
 
-static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
+static int cpu_up(unsigned int cpu, enum cpuhp_state target)
 {
 	int err = 0;
 
@@ -1272,16 +1340,70 @@
 	return err;
 }
 
-int cpu_up(unsigned int cpu)
+/**
+ * cpu_device_up - Bring up a cpu device
+ * @dev: Pointer to the cpu device to online
+ *
+ * This function is meant to be used by device core cpu subsystem only.
+ *
+ * Other subsystems should use add_cpu() instead.
+ */
+int cpu_device_up(struct device *dev)
 {
-	return do_cpu_up(cpu, CPUHP_ONLINE);
+	return cpu_up(dev->id, CPUHP_ONLINE);
 }
-EXPORT_SYMBOL_GPL(cpu_up);
+
+int add_cpu(unsigned int cpu)
+{
+	int ret;
+
+	lock_device_hotplug();
+	ret = device_online(get_cpu_device(cpu));
+	unlock_device_hotplug();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(add_cpu);
+
+/**
+ * bringup_hibernate_cpu - Bring up the CPU that we hibernated on
+ * @sleep_cpu: The cpu we hibernated on and should be brought up.
+ *
+ * On some architectures like arm64, we can hibernate on any CPU, but on
+ * wake up the CPU we hibernated on might be offline as a side effect of
+ * using maxcpus= for example.
+ */
+int bringup_hibernate_cpu(unsigned int sleep_cpu)
+{
+	int ret;
+
+	if (!cpu_online(sleep_cpu)) {
+		pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n");
+		ret = cpu_up(sleep_cpu, CPUHP_ONLINE);
+		if (ret) {
+			pr_err("Failed to bring hibernate-CPU up!\n");
+			return ret;
+		}
+	}
+	return 0;
+}
+
+void bringup_nonboot_cpus(unsigned int setup_max_cpus)
+{
+	unsigned int cpu;
+
+	for_each_present_cpu(cpu) {
+		if (num_online_cpus() >= setup_max_cpus)
+			break;
+		if (!cpu_online(cpu))
+			cpu_up(cpu, CPUHP_ONLINE);
+	}
+}
 
 #ifdef CONFIG_PM_SLEEP_SMP
 static cpumask_var_t frozen_cpus;
 
-int __freeze_secondary_cpus(int primary, bool suspend)
+int freeze_secondary_cpus(int primary)
 {
 	int cpu, error = 0;
 
@@ -1306,7 +1428,7 @@
 		if (cpu == primary)
 			continue;
 
-		if (suspend && pm_wakeup_pending()) {
+		if (pm_wakeup_pending()) {
 			pr_info("Wakeup pending. Abort CPU freeze\n");
 			error = -EBUSY;
 			break;
@@ -1330,8 +1452,8 @@
 
 	/*
 	 * Make sure the CPUs won't be enabled by someone else. We need to do
-	 * this even in case of failure as all disable_nonboot_cpus() users are
-	 * supposed to do enable_nonboot_cpus() on the failure path.
+	 * this even in case of failure as all freeze_secondary_cpus() users are
+	 * supposed to do thaw_secondary_cpus() on the failure path.
 	 */
 	cpu_hotplug_disabled++;
 
@@ -1339,15 +1461,15 @@
 	return error;
 }
 
-void __weak arch_enable_nonboot_cpus_begin(void)
+void __weak arch_thaw_secondary_cpus_begin(void)
 {
 }
 
-void __weak arch_enable_nonboot_cpus_end(void)
+void __weak arch_thaw_secondary_cpus_end(void)
 {
 }
 
-void enable_nonboot_cpus(void)
+void thaw_secondary_cpus(void)
 {
 	int cpu, error;
 
@@ -1359,7 +1481,7 @@
 
 	pr_info("Enabling non-boot CPUs ...\n");
 
-	arch_enable_nonboot_cpus_begin();
+	arch_thaw_secondary_cpus_begin();
 
 	for_each_cpu(cpu, frozen_cpus) {
 		trace_suspend_resume(TPS("CPU_ON"), cpu, true);
@@ -1372,7 +1494,7 @@
 		pr_warn("Error taking CPU%d up: %d\n", cpu, error);
 	}
 
-	arch_enable_nonboot_cpus_end();
+	arch_thaw_secondary_cpus_end();
 
 	cpumask_clear(frozen_cpus);
 out:
@@ -2097,9 +2219,9 @@
 		goto out;
 
 	if (st->state < target)
-		ret = do_cpu_up(dev->id, target);
+		ret = cpu_up(dev->id, target);
 	else
-		ret = do_cpu_down(dev->id, target);
+		ret = cpu_down(dev->id, target);
 out:
 	unlock_device_hotplug();
 	return ret ? ret : count;
diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c
index 44a2593..246efc7 100644
--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -13,20 +13,46 @@
 #include <linux/spinlock.h>
 #include <linux/syscore_ops.h>
 
-static ATOMIC_NOTIFIER_HEAD(cpu_pm_notifier_chain);
+/*
+ * atomic_notifiers use a spinlock_t, which can block under PREEMPT_RT.
+ * Notifications for cpu_pm will be issued by the idle task itself, which can
+ * never block, IOW it requires using a raw_spinlock_t.
+ */
+static struct {
+	struct raw_notifier_head chain;
+	raw_spinlock_t lock;
+} cpu_pm_notifier = {
+	.chain = RAW_NOTIFIER_INIT(cpu_pm_notifier.chain),
+	.lock  = __RAW_SPIN_LOCK_UNLOCKED(cpu_pm_notifier.lock),
+};
 
-static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls)
+static int cpu_pm_notify(enum cpu_pm_event event)
 {
 	int ret;
 
 	/*
-	 * __atomic_notifier_call_chain has a RCU read critical section, which
-	 * could be disfunctional in cpu idle. Copy RCU_NONIDLE code to let
-	 * RCU know this.
+	 * This introduces a RCU read critical section, which could be
+	 * disfunctional in cpu idle. Copy RCU_NONIDLE code to let RCU know
+	 * this.
 	 */
 	rcu_irq_enter_irqson();
-	ret = __atomic_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL,
-		nr_to_call, nr_calls);
+	rcu_read_lock();
+	ret = raw_notifier_call_chain(&cpu_pm_notifier.chain, event, NULL);
+	rcu_read_unlock();
+	rcu_irq_exit_irqson();
+
+	return notifier_to_errno(ret);
+}
+
+static int cpu_pm_notify_robust(enum cpu_pm_event event_up, enum cpu_pm_event event_down)
+{
+	unsigned long flags;
+	int ret;
+
+	rcu_irq_enter_irqson();
+	raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags);
+	ret = raw_notifier_call_chain_robust(&cpu_pm_notifier.chain, event_up, event_down, NULL);
+	raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags);
 	rcu_irq_exit_irqson();
 
 	return notifier_to_errno(ret);
@@ -39,12 +65,17 @@
  * Add a driver to a list of drivers that are notified about
  * CPU and CPU cluster low power entry and exit.
  *
- * This function may sleep, and has the same return conditions as
- * raw_notifier_chain_register.
+ * This function has the same return conditions as raw_notifier_chain_register.
  */
 int cpu_pm_register_notifier(struct notifier_block *nb)
 {
-	return atomic_notifier_chain_register(&cpu_pm_notifier_chain, nb);
+	unsigned long flags;
+	int ret;
+
+	raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags);
+	ret = raw_notifier_chain_register(&cpu_pm_notifier.chain, nb);
+	raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(cpu_pm_register_notifier);
 
@@ -54,12 +85,17 @@
  *
  * Remove a driver from the CPU PM notifier list.
  *
- * This function may sleep, and has the same return conditions as
- * raw_notifier_chain_unregister.
+ * This function has the same return conditions as raw_notifier_chain_unregister.
  */
 int cpu_pm_unregister_notifier(struct notifier_block *nb)
 {
-	return atomic_notifier_chain_unregister(&cpu_pm_notifier_chain, nb);
+	unsigned long flags;
+	int ret;
+
+	raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags);
+	ret = raw_notifier_chain_unregister(&cpu_pm_notifier.chain, nb);
+	raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier);
 
@@ -80,18 +116,7 @@
  */
 int cpu_pm_enter(void)
 {
-	int nr_calls = 0;
-	int ret = 0;
-
-	ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls);
-	if (ret)
-		/*
-		 * Inform listeners (nr_calls - 1) about failure of CPU PM
-		 * PM entry who are notified earlier to prepare for it.
-		 */
-		cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL);
-
-	return ret;
+	return cpu_pm_notify_robust(CPU_PM_ENTER, CPU_PM_ENTER_FAILED);
 }
 EXPORT_SYMBOL_GPL(cpu_pm_enter);
 
@@ -109,7 +134,7 @@
  */
 int cpu_pm_exit(void)
 {
-	return cpu_pm_notify(CPU_PM_EXIT, -1, NULL);
+	return cpu_pm_notify(CPU_PM_EXIT);
 }
 EXPORT_SYMBOL_GPL(cpu_pm_exit);
 
@@ -131,18 +156,7 @@
  */
 int cpu_cluster_pm_enter(void)
 {
-	int nr_calls = 0;
-	int ret = 0;
-
-	ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls);
-	if (ret)
-		/*
-		 * Inform listeners (nr_calls - 1) about failure of CPU cluster
-		 * PM entry who are notified earlier to prepare for it.
-		 */
-		cpu_pm_notify(CPU_CLUSTER_PM_ENTER_FAILED, nr_calls - 1, NULL);
-
-	return ret;
+	return cpu_pm_notify_robust(CPU_CLUSTER_PM_ENTER, CPU_CLUSTER_PM_ENTER_FAILED);
 }
 EXPORT_SYMBOL_GPL(cpu_cluster_pm_enter);
 
@@ -163,7 +177,7 @@
  */
 int cpu_cluster_pm_exit(void)
 {
-	return cpu_pm_notify(CPU_CLUSTER_PM_EXIT, -1, NULL);
+	return cpu_pm_notify(CPU_CLUSTER_PM_EXIT);
 }
 EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit);
 
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 9f1557b..4a5fed2 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -11,6 +11,8 @@
 #include <asm/page.h>
 #include <asm/sections.h>
 
+#include <crypto/sha.h>
+
 /* vmcoreinfo stuff */
 unsigned char *vmcoreinfo_data;
 size_t vmcoreinfo_size;
@@ -376,6 +378,53 @@
 }
 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 
+#define NOTES_SIZE (&__stop_notes - &__start_notes)
+#define BUILD_ID_MAX SHA1_DIGEST_SIZE
+#define NT_GNU_BUILD_ID 3
+
+struct elf_note_section {
+	struct elf_note	n_hdr;
+	u8 n_data[];
+};
+
+/*
+ * Add build ID from .notes section as generated by the GNU ld(1)
+ * or LLVM lld(1) --build-id option.
+ */
+static void add_build_id_vmcoreinfo(void)
+{
+	char build_id[BUILD_ID_MAX * 2 + 1];
+	int n_remain = NOTES_SIZE;
+
+	while (n_remain >= sizeof(struct elf_note)) {
+		const struct elf_note_section *note_sec =
+			&__start_notes + NOTES_SIZE - n_remain;
+		const u32 n_namesz = note_sec->n_hdr.n_namesz;
+
+		if (note_sec->n_hdr.n_type == NT_GNU_BUILD_ID &&
+		    n_namesz != 0 &&
+		    !strcmp((char *)&note_sec->n_data[0], "GNU")) {
+			if (note_sec->n_hdr.n_descsz <= BUILD_ID_MAX) {
+				const u32 n_descsz = note_sec->n_hdr.n_descsz;
+				const u8 *s = &note_sec->n_data[n_namesz];
+
+				s = PTR_ALIGN(s, 4);
+				bin2hex(build_id, s, n_descsz);
+				build_id[2 * n_descsz] = '\0';
+				VMCOREINFO_BUILD_ID(build_id);
+				return;
+			}
+			pr_warn("Build ID is too large to include in vmcoreinfo: %u > %u\n",
+				note_sec->n_hdr.n_descsz,
+				BUILD_ID_MAX);
+			return;
+		}
+		n_remain -= sizeof(struct elf_note) +
+			ALIGN(note_sec->n_hdr.n_namesz, 4) +
+			ALIGN(note_sec->n_hdr.n_descsz, 4);
+	}
+}
+
 static int __init crash_save_vmcoreinfo_init(void)
 {
 	vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
@@ -394,6 +443,7 @@
 	}
 
 	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
+	add_build_id_vmcoreinfo();
 	VMCOREINFO_PAGESIZE(PAGE_SIZE);
 
 	VMCOREINFO_SYMBOL(init_uts_ns);
@@ -413,6 +463,8 @@
 	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
 	VMCOREINFO_STRUCT_SIZE(mem_section);
 	VMCOREINFO_OFFSET(mem_section, section_mem_map);
+	VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
+	VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
 #endif
 	VMCOREINFO_STRUCT_SIZE(page);
 	VMCOREINFO_STRUCT_SIZE(pglist_data);
diff --git a/kernel/crash_dump.c b/kernel/crash_dump.c
index 9c23ae0..92da322 100644
--- a/kernel/crash_dump.c
+++ b/kernel/crash_dump.c
@@ -6,12 +6,6 @@
 #include <linux/export.h>
 
 /*
- * If we have booted due to a crash, max_pfn will be a very low value. We need
- * to know the amount of memory that the previous kernel used.
- */
-unsigned long saved_max_pfn;
-
-/*
  * stores the physical address of elf header of crash image
  *
  * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
diff --git a/kernel/cred.c b/kernel/cred.c
index 809a985..421b114 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -315,6 +315,9 @@
 	new->process_keyring = NULL;
 #endif
 
+	new->suid = new->fsuid = new->euid;
+	new->sgid = new->fsgid = new->egid;
+
 	return new;
 }
 
@@ -675,8 +678,6 @@
  * The caller may change these controls afterwards if desired.
  *
  * Returns the new credentials or NULL if out of memory.
- *
- * Does not take, and does not return holding current->cred_replace_mutex.
  */
 struct cred *prepare_kernel_cred(struct task_struct *daemon)
 {
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 097ab02..8661eb2 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -67,9 +67,7 @@
 
 struct debuggerinfo_struct kgdb_info[NR_CPUS];
 
-/**
- * kgdb_connected - Is a host GDB connected to us?
- */
+/* kgdb_connected - Is a host GDB connected to us? */
 int				kgdb_connected;
 EXPORT_SYMBOL_GPL(kgdb_connected);
 
@@ -82,7 +80,7 @@
 struct kgdb_io		*dbg_io_ops;
 static DEFINE_SPINLOCK(kgdb_registration_lock);
 
-/* Action for the reboot notifiter, a global allow kdb to change it */
+/* Action for the reboot notifier, a global allow kdb to change it */
 static int kgdbreboot;
 /* kgdb console driver is loaded */
 static int kgdb_con_registered;
@@ -157,31 +155,37 @@
 
 /*
  * Weak aliases for breakpoint management,
- * can be overriden by architectures when needed:
+ * can be overridden by architectures when needed:
  */
 int __weak kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
 {
 	int err;
 
-	err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
+	err = copy_from_kernel_nofault(bpt->saved_instr, (char *)bpt->bpt_addr,
 				BREAK_INSTR_SIZE);
 	if (err)
 		return err;
-	err = probe_kernel_write((char *)bpt->bpt_addr,
+	err = copy_to_kernel_nofault((char *)bpt->bpt_addr,
 				 arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE);
 	return err;
 }
+NOKPROBE_SYMBOL(kgdb_arch_set_breakpoint);
 
 int __weak kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
 {
-	return probe_kernel_write((char *)bpt->bpt_addr,
+	return copy_to_kernel_nofault((char *)bpt->bpt_addr,
 				  (char *)bpt->saved_instr, BREAK_INSTR_SIZE);
 }
+NOKPROBE_SYMBOL(kgdb_arch_remove_breakpoint);
 
 int __weak kgdb_validate_break_address(unsigned long addr)
 {
 	struct kgdb_bkpt tmp;
 	int err;
+
+	if (kgdb_within_blocklist(addr))
+		return -EINVAL;
+
 	/* Validate setting the breakpoint and then removing it.  If the
 	 * remove fails, the kernel needs to emit a bad message because we
 	 * are deep trouble not being able to put things back the way we
@@ -202,6 +206,7 @@
 {
 	return instruction_pointer(regs);
 }
+NOKPROBE_SYMBOL(kgdb_arch_pc);
 
 int __weak kgdb_arch_init(void)
 {
@@ -212,6 +217,7 @@
 {
 	return 0;
 }
+NOKPROBE_SYMBOL(kgdb_skipexception);
 
 #ifdef CONFIG_SMP
 
@@ -233,6 +239,7 @@
 	 */
 	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
 }
+NOKPROBE_SYMBOL(kgdb_call_nmi_hook);
 
 void __weak kgdb_roundup_cpus(void)
 {
@@ -266,6 +273,7 @@
 			kgdb_info[cpu].rounding_up = false;
 	}
 }
+NOKPROBE_SYMBOL(kgdb_roundup_cpus);
 
 #endif
 
@@ -292,6 +300,7 @@
 	/* Force flush instruction cache if it was outside the mm */
 	flush_icache_range(addr, addr + BREAK_INSTR_SIZE);
 }
+NOKPROBE_SYMBOL(kgdb_flush_swbreak_addr);
 
 /*
  * SW breakpoint management:
@@ -319,6 +328,7 @@
 	}
 	return ret;
 }
+NOKPROBE_SYMBOL(dbg_activate_sw_breakpoints);
 
 int dbg_set_sw_break(unsigned long addr)
 {
@@ -382,6 +392,7 @@
 	}
 	return ret;
 }
+NOKPROBE_SYMBOL(dbg_deactivate_sw_breakpoints);
 
 int dbg_remove_sw_break(unsigned long addr)
 {
@@ -409,6 +420,18 @@
 	return 0;
 }
 
+int kgdb_has_hit_break(unsigned long addr)
+{
+	int i;
+
+	for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+		if (kgdb_break[i].state == BP_ACTIVE &&
+		    kgdb_break[i].bpt_addr == addr)
+			return 1;
+	}
+	return 0;
+}
+
 int dbg_remove_all_break(void)
 {
 	int error;
@@ -433,6 +456,48 @@
 	return 0;
 }
 
+void kgdb_free_init_mem(void)
+{
+	int i;
+
+	/* Clear init memory breakpoints. */
+	for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+		if (init_section_contains((void *)kgdb_break[i].bpt_addr, 0))
+			kgdb_break[i].state = BP_UNDEFINED;
+	}
+}
+
+#ifdef CONFIG_KGDB_KDB
+void kdb_dump_stack_on_cpu(int cpu)
+{
+	if (cpu == raw_smp_processor_id() || !IS_ENABLED(CONFIG_SMP)) {
+		dump_stack();
+		return;
+	}
+
+	if (!(kgdb_info[cpu].exception_state & DCPU_IS_SLAVE)) {
+		kdb_printf("ERROR: Task on cpu %d didn't stop in the debugger\n",
+			   cpu);
+		return;
+	}
+
+	/*
+	 * In general, architectures don't support dumping the stack of a
+	 * "running" process that's not the current one.  From the point of
+	 * view of the Linux, kernel processes that are looping in the kgdb
+	 * slave loop are still "running".  There's also no API (that actually
+	 * works across all architectures) that can do a stack crawl based
+	 * on registers passed as a parameter.
+	 *
+	 * Solve this conundrum by asking slave CPUs to do the backtrace
+	 * themselves.
+	 */
+	kgdb_info[cpu].exception_state |= DCPU_WANT_BT;
+	while (kgdb_info[cpu].exception_state & DCPU_WANT_BT)
+		cpu_relax();
+}
+#endif
+
 /*
  * Return true if there is a valid kgdb I/O module.  Also if no
  * debugger is attached a message can be printed to the console about
@@ -460,6 +525,7 @@
 	}
 	return 1;
 }
+NOKPROBE_SYMBOL(kgdb_io_ready);
 
 static int kgdb_reenter_check(struct kgdb_state *ks)
 {
@@ -507,6 +573,7 @@
 
 	return 1;
 }
+NOKPROBE_SYMBOL(kgdb_reenter_check);
 
 static void dbg_touch_watchdogs(void)
 {
@@ -514,6 +581,7 @@
 	clocksource_touch_watchdog();
 	rcu_cpu_stall_reset();
 }
+NOKPROBE_SYMBOL(dbg_touch_watchdogs);
 
 static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
 		int exception_state)
@@ -574,6 +642,9 @@
 				atomic_xchg(&kgdb_active, cpu);
 				break;
 			}
+		} else if (kgdb_info[cpu].exception_state & DCPU_WANT_BT) {
+			dump_stack();
+			kgdb_info[cpu].exception_state &= ~DCPU_WANT_BT;
 		} else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
 			if (!raw_spin_is_locked(&dbg_slave_lock))
 				goto return_normal;
@@ -700,6 +771,8 @@
 		}
 	}
 
+	dbg_activate_sw_breakpoints();
+
 	/* Call the I/O driver's post_exception routine */
 	if (dbg_io_ops->post_exception)
 		dbg_io_ops->post_exception();
@@ -742,6 +815,7 @@
 
 	return kgdb_info[cpu].ret_state;
 }
+NOKPROBE_SYMBOL(kgdb_cpu_enter);
 
 /*
  * kgdb_handle_exception() - main entry point from a kernel exception
@@ -786,6 +860,7 @@
 		arch_kgdb_ops.enable_nmi(1);
 	return ret;
 }
+NOKPROBE_SYMBOL(kgdb_handle_exception);
 
 /*
  * GDB places a breakpoint at this function to know dynamically loaded objects.
@@ -820,6 +895,7 @@
 #endif
 	return 1;
 }
+NOKPROBE_SYMBOL(kgdb_nmicallback);
 
 int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code,
 							atomic_t *send_ready)
@@ -845,6 +921,7 @@
 #endif
 	return 1;
 }
+NOKPROBE_SYMBOL(kgdb_nmicallin);
 
 static void kgdb_console_write(struct console *co, const char *s,
    unsigned count)
@@ -901,7 +978,7 @@
 	kgdb_breakpoint();
 }
 
-static struct sysrq_key_op sysrq_dbg_op = {
+static const struct sysrq_key_op sysrq_dbg_op = {
 	.handler	= sysrq_handle_dbg,
 	.help_msg	= "debug(g)",
 	.action_msg	= "DEBUG",
@@ -927,6 +1004,14 @@
 	kgdb_breakpoint();
 }
 
+static void kgdb_initial_breakpoint(void)
+{
+	kgdb_break_asap = 0;
+
+	pr_crit("Waiting for connection from remote gdb...\n");
+	kgdb_breakpoint();
+}
+
 void __weak kgdb_arch_late(void)
 {
 }
@@ -937,6 +1022,9 @@
 	if (kgdb_io_module_registered)
 		kgdb_arch_late();
 	kdb_init(KDB_INIT_FULL);
+
+	if (kgdb_io_module_registered && kgdb_break_asap)
+		kgdb_initial_breakpoint();
 }
 
 static int
@@ -1019,7 +1107,7 @@
 	atomic_set(&kgdb_break_tasklet_var, 0);
 }
 
-static DECLARE_TASKLET(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt, 0);
+static DECLARE_TASKLET_OLD(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt);
 
 void kgdb_schedule_breakpoint(void)
 {
@@ -1032,14 +1120,6 @@
 }
 EXPORT_SYMBOL_GPL(kgdb_schedule_breakpoint);
 
-static void kgdb_initial_breakpoint(void)
-{
-	kgdb_break_asap = 0;
-
-	pr_crit("Waiting for connection from remote gdb...\n");
-	kgdb_breakpoint();
-}
-
 /**
  *	kgdb_register_io_module - register KGDB IO module
  *	@new_dbg_io_ops: the io ops vector
@@ -1048,15 +1128,22 @@
  */
 int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
 {
+	struct kgdb_io *old_dbg_io_ops;
 	int err;
 
 	spin_lock(&kgdb_registration_lock);
 
-	if (dbg_io_ops) {
-		spin_unlock(&kgdb_registration_lock);
+	old_dbg_io_ops = dbg_io_ops;
+	if (old_dbg_io_ops) {
+		if (!old_dbg_io_ops->deinit) {
+			spin_unlock(&kgdb_registration_lock);
 
-		pr_err("Another I/O driver is already registered with KGDB\n");
-		return -EBUSY;
+			pr_err("KGDB I/O driver %s can't replace %s.\n",
+				new_dbg_io_ops->name, old_dbg_io_ops->name);
+			return -EBUSY;
+		}
+		pr_info("Replacing I/O driver %s with %s\n",
+			old_dbg_io_ops->name, new_dbg_io_ops->name);
 	}
 
 	if (new_dbg_io_ops->init) {
@@ -1071,12 +1158,18 @@
 
 	spin_unlock(&kgdb_registration_lock);
 
+	if (old_dbg_io_ops) {
+		old_dbg_io_ops->deinit();
+		return 0;
+	}
+
 	pr_info("Registered I/O driver %s\n", new_dbg_io_ops->name);
 
 	/* Arm KGDB now. */
 	kgdb_register_callbacks();
 
-	if (kgdb_break_asap)
+	if (kgdb_break_asap &&
+	    (!dbg_is_early || IS_ENABLED(CONFIG_ARCH_HAS_EARLY_DEBUG)))
 		kgdb_initial_breakpoint();
 
 	return 0;
@@ -1106,6 +1199,9 @@
 
 	spin_unlock(&kgdb_registration_lock);
 
+	if (old_dbg_io_ops->deinit)
+		old_dbg_io_ops->deinit();
+
 	pr_info("Unregistered I/O driver %s, debugger disabled\n",
 		old_dbg_io_ops->name);
 }
@@ -1146,7 +1242,8 @@
 	kgdb_break_asap = 1;
 
 	kdb_init(KDB_INIT_EARLY);
-	if (kgdb_io_module_registered)
+	if (kgdb_io_module_registered &&
+	    IS_ENABLED(CONFIG_ARCH_HAS_EARLY_DEBUG))
 		kgdb_initial_breakpoint();
 
 	return 0;
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index b4a7c32..cd22b5f 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -33,7 +33,7 @@
 #define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */
 #define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */
 #define DCPU_IS_SLAVE    0x4 /* Slave cpu enter exception */
-#define DCPU_SSTEP       0x8 /* CPU is single stepping */
+#define DCPU_WANT_BT     0x8 /* Slave cpu should backtrace then clear flag */
 
 struct debuggerinfo_struct {
 	void			*debuggerinfo;
@@ -76,6 +76,7 @@
 extern int kdb_parse(const char *cmdstr);
 extern int kdb_common_init_state(struct kgdb_state *ks);
 extern int kdb_common_deinit_state(void);
+extern void kdb_dump_stack_on_cpu(int cpu);
 #else /* ! CONFIG_KGDB_KDB */
 static inline int kdb_stub(struct kgdb_state *ks)
 {
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index 4b280fc..a77df59 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -247,7 +247,7 @@
 	 */
 	tmp = buf + count;
 
-	err = probe_kernel_read(tmp, mem, count);
+	err = copy_from_kernel_nofault(tmp, mem, count);
 	if (err)
 		return NULL;
 	while (count > 0) {
@@ -283,7 +283,7 @@
 		*tmp_raw |= hex_to_bin(*tmp_hex--) << 4;
 	}
 
-	return probe_kernel_write(mem, tmp_raw, count);
+	return copy_to_kernel_nofault(mem, tmp_raw, count);
 }
 
 /*
@@ -335,7 +335,7 @@
 		size++;
 	}
 
-	return probe_kernel_write(mem, c, size);
+	return copy_to_kernel_nofault(mem, c, size);
 }
 
 #if DBG_MAX_REG_NUM > 0
@@ -725,7 +725,7 @@
 			}
 		}
 
-		do_each_thread(g, p) {
+		for_each_process_thread(g, p) {
 			if (i >= ks->thr_query && !finished) {
 				int_to_threadref(thref, p->pid);
 				ptr = pack_threadid(ptr, thref);
@@ -735,7 +735,7 @@
 					finished = 1;
 			}
 			i++;
-		} while_each_thread(g, p);
+		}
 
 		*(--ptr) = '\0';
 		break;
@@ -792,6 +792,19 @@
 		}
 		break;
 #endif
+#ifdef CONFIG_HAVE_ARCH_KGDB_QXFER_PKT
+	case 'S':
+		if (!strncmp(remcom_in_buffer, "qSupported:", 11))
+			strcpy(remcom_out_buffer, kgdb_arch_gdb_stub_feature);
+		break;
+	case 'X':
+		if (!strncmp(remcom_in_buffer, "qXfer:", 6))
+			kgdb_arch_handle_qxfer_pkt(remcom_in_buffer,
+						   remcom_out_buffer);
+		break;
+#endif
+	default:
+		break;
 	}
 }
 
@@ -1033,14 +1046,14 @@
 				return DBG_PASS_EVENT;
 			}
 #endif
-			/* Fall through */
+			fallthrough;
 		case 'C': /* Exception passing */
 			tmp = gdb_cmd_exception_pass(ks);
 			if (tmp > 0)
 				goto default_handle;
 			if (tmp == 0)
 				break;
-			/* Fall through - on tmp < 0 */
+			fallthrough;	/* on tmp < 0 */
 		case 'c': /* Continue packet */
 		case 's': /* Single step packet */
 			if (kgdb_contthread && kgdb_contthread != current) {
@@ -1048,8 +1061,7 @@
 				error_packet(remcom_out_buffer, -EINVAL);
 				break;
 			}
-			dbg_activate_sw_breakpoints();
-			/* Fall through - to default processing */
+			fallthrough;	/* to default processing */
 		default:
 default_handle:
 			error = kgdb_arch_handle_exception(ks->ex_vector,
diff --git a/kernel/debug/kdb/.gitignore b/kernel/debug/kdb/.gitignore
index 396d12e..df25954 100644
--- a/kernel/debug/kdb/.gitignore
+++ b/kernel/debug/kdb/.gitignore
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
 gen-kdb_cmds.c
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index 62c301a..ec49401 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -307,6 +307,15 @@
 		return KDB_BADINT;
 
 	/*
+	 * This check is redundant (since the breakpoint machinery should
+	 * be doing the same check during kdb_bp_install) but gives the
+	 * user immediate feedback.
+	 */
+	diag = kgdb_validate_break_address(template.bp_addr);
+	if (diag)
+		return diag;
+
+	/*
 	 * Find an empty bp structure to allocate
 	 */
 	for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; bpno++, bp++) {
@@ -412,7 +421,6 @@
 		 * assume that the breakpoint number is desired.
 		 */
 		if (addr < KDB_MAXBPT) {
-			bp = &kdb_breakpoints[addr];
 			lowbp = highbp = addr;
 			highbp++;
 		} else {
diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c
index 7e2379a..1f9f0e4 100644
--- a/kernel/debug/kdb/kdb_bt.c
+++ b/kernel/debug/kdb/kdb_bt.c
@@ -21,22 +21,18 @@
 
 static void kdb_show_stack(struct task_struct *p, void *addr)
 {
-	int old_lvl = console_loglevel;
-	console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
 	kdb_trap_printk++;
-	kdb_set_current_task(p);
-	if (addr) {
-		show_stack((struct task_struct *)p, addr);
-	} else if (kdb_current_regs) {
-#ifdef CONFIG_X86
-		show_stack(p, &kdb_current_regs->sp);
-#else
-		show_stack(p, NULL);
-#endif
+
+	if (!addr && kdb_task_has_cpu(p)) {
+		int old_lvl = console_loglevel;
+
+		console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
+		kdb_dump_stack_on_cpu(kdb_process_cpu(p));
+		console_loglevel = old_lvl;
 	} else {
-		show_stack(p, NULL);
+		show_stack(p, addr, KERN_EMERG);
 	}
-	console_loglevel = old_lvl;
+
 	kdb_trap_printk--;
 }
 
@@ -78,12 +74,12 @@
  */
 
 static int
-kdb_bt1(struct task_struct *p, unsigned long mask,
-	int argcount, int btaprompt)
+kdb_bt1(struct task_struct *p, unsigned long mask, bool btaprompt)
 {
-	char buffer[2];
-	if (kdb_getarea(buffer[0], (unsigned long)p) ||
-	    kdb_getarea(buffer[0], (unsigned long)(p+1)-1))
+	char ch;
+
+	if (kdb_getarea(ch, (unsigned long)p) ||
+	    kdb_getarea(ch, (unsigned long)(p+1)-1))
 		return KDB_BADADDR;
 	if (!kdb_task_state(p, mask))
 		return 0;
@@ -91,22 +87,46 @@
 	kdb_ps1(p);
 	kdb_show_stack(p, NULL);
 	if (btaprompt) {
-		kdb_getstr(buffer, sizeof(buffer),
-			   "Enter <q> to end, <cr> to continue:");
-		if (buffer[0] == 'q') {
-			kdb_printf("\n");
+		kdb_printf("Enter <q> to end, <cr> or <space> to continue:");
+		do {
+			ch = kdb_getchar();
+		} while (!strchr("\r\n q", ch));
+		kdb_printf("\n");
+
+		/* reset the pager */
+		kdb_nextline = 1;
+
+		if (ch == 'q')
 			return 1;
-		}
 	}
 	touch_nmi_watchdog();
 	return 0;
 }
 
+static void
+kdb_bt_cpu(unsigned long cpu)
+{
+	struct task_struct *kdb_tsk;
+
+	if (cpu >= num_possible_cpus() || !cpu_online(cpu)) {
+		kdb_printf("WARNING: no process for cpu %ld\n", cpu);
+		return;
+	}
+
+	/* If a CPU failed to round up we could be here */
+	kdb_tsk = KDB_TSK(cpu);
+	if (!kdb_tsk) {
+		kdb_printf("WARNING: no task for cpu %ld\n", cpu);
+		return;
+	}
+
+	kdb_bt1(kdb_tsk, ~0UL, false);
+}
+
 int
 kdb_bt(int argc, const char **argv)
 {
 	int diag;
-	int argcount = 5;
 	int btaprompt = 1;
 	int nextarg;
 	unsigned long addr;
@@ -125,18 +145,18 @@
 		/* Run the active tasks first */
 		for_each_online_cpu(cpu) {
 			p = kdb_curr_task(cpu);
-			if (kdb_bt1(p, mask, argcount, btaprompt))
+			if (kdb_bt1(p, mask, btaprompt))
 				return 0;
 		}
 		/* Now the inactive tasks */
-		kdb_do_each_thread(g, p) {
+		for_each_process_thread(g, p) {
 			if (KDB_FLAG(CMD_INTERRUPT))
 				return 0;
 			if (task_curr(p))
 				continue;
-			if (kdb_bt1(p, mask, argcount, btaprompt))
+			if (kdb_bt1(p, mask, btaprompt))
 				return 0;
-		} kdb_while_each_thread(g, p);
+		}
 	} else if (strcmp(argv[0], "btp") == 0) {
 		struct task_struct *p;
 		unsigned long pid;
@@ -146,10 +166,8 @@
 		if (diag)
 			return diag;
 		p = find_task_by_pid_ns(pid, &init_pid_ns);
-		if (p) {
-			kdb_set_current_task(p);
-			return kdb_bt1(p, ~0UL, argcount, 0);
-		}
+		if (p)
+			return kdb_bt1(p, ~0UL, false);
 		kdb_printf("No process with pid == %ld found\n", pid);
 		return 0;
 	} else if (strcmp(argv[0], "btt") == 0) {
@@ -158,12 +176,9 @@
 		diag = kdbgetularg((char *)argv[1], &addr);
 		if (diag)
 			return diag;
-		kdb_set_current_task((struct task_struct *)addr);
-		return kdb_bt1((struct task_struct *)addr, ~0UL, argcount, 0);
+		return kdb_bt1((struct task_struct *)addr, ~0UL, false);
 	} else if (strcmp(argv[0], "btc") == 0) {
 		unsigned long cpu = ~0;
-		struct task_struct *save_current_task = kdb_current_task;
-		char buf[80];
 		if (argc > 1)
 			return KDB_ARGCOUNT;
 		if (argc == 1) {
@@ -171,35 +186,21 @@
 			if (diag)
 				return diag;
 		}
-		/* Recursive use of kdb_parse, do not use argv after
-		 * this point */
-		argv = NULL;
 		if (cpu != ~0) {
-			if (cpu >= num_possible_cpus() || !cpu_online(cpu)) {
-				kdb_printf("no process for cpu %ld\n", cpu);
-				return 0;
+			kdb_bt_cpu(cpu);
+		} else {
+			/*
+			 * Recursive use of kdb_parse, do not use argv after
+			 * this point.
+			 */
+			argv = NULL;
+			kdb_printf("btc: cpu status: ");
+			kdb_parse("cpu\n");
+			for_each_online_cpu(cpu) {
+				kdb_bt_cpu(cpu);
+				touch_nmi_watchdog();
 			}
-			sprintf(buf, "btt 0x%px\n", KDB_TSK(cpu));
-			kdb_parse(buf);
-			return 0;
 		}
-		kdb_printf("btc: cpu status: ");
-		kdb_parse("cpu\n");
-		for_each_online_cpu(cpu) {
-			void *kdb_tsk = KDB_TSK(cpu);
-
-			/* If a CPU failed to round up we could be here */
-			if (!kdb_tsk) {
-				kdb_printf("WARNING: no task for cpu %ld\n",
-					   cpu);
-				continue;
-			}
-
-			sprintf(buf, "btt 0x%px\n", kdb_tsk);
-			kdb_parse(buf);
-			touch_nmi_watchdog();
-		}
-		kdb_set_current_task(save_current_task);
 		return 0;
 	} else {
 		if (argc) {
@@ -211,7 +212,7 @@
 			kdb_show_stack(kdb_current_task, (void *)addr);
 			return 0;
 		} else {
-			return kdb_bt1(kdb_current_task, ~0UL, argcount, 0);
+			return kdb_bt1(kdb_current_task, ~0UL, false);
 		}
 	}
 
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index 53a0df6..0220afd 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -147,7 +147,6 @@
 		return DBG_PASS_EVENT;
 	}
 	kdb_bp_install(ks->linux_regs);
-	dbg_activate_sw_breakpoints();
 	/* Set the exit state to a single step or a continue */
 	if (KDB_STATE(DOING_SS))
 		gdbstub_state(ks, "s");
@@ -167,7 +166,6 @@
 		 * differently vs the gdbstub
 		 */
 		kgdb_single_step = 0;
-		dbg_deactivate_sw_breakpoints();
 		return DBG_SWITCH_CPU_EVENT;
 	}
 	return kgdb_info[ks->cpu].ret_state;
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 4682179..6735ac3 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -49,14 +49,88 @@
 	return 0;
 }
 
-static int kdb_read_get_key(char *buffer, size_t bufsize)
+/**
+ * kdb_handle_escape() - validity check on an accumulated escape sequence.
+ * @buf:	Accumulated escape characters to be examined. Note that buf
+ *		is not a string, it is an array of characters and need not be
+ *		nil terminated.
+ * @sz:		Number of accumulated escape characters.
+ *
+ * Return: -1 if the escape sequence is unwanted, 0 if it is incomplete,
+ * otherwise it returns a mapped key value to pass to the upper layers.
+ */
+static int kdb_handle_escape(char *buf, size_t sz)
+{
+	char *lastkey = buf + sz - 1;
+
+	switch (sz) {
+	case 1:
+		if (*lastkey == '\e')
+			return 0;
+		break;
+
+	case 2: /* \e<something> */
+		if (*lastkey == '[')
+			return 0;
+		break;
+
+	case 3:
+		switch (*lastkey) {
+		case 'A': /* \e[A, up arrow */
+			return 16;
+		case 'B': /* \e[B, down arrow */
+			return 14;
+		case 'C': /* \e[C, right arrow */
+			return 6;
+		case 'D': /* \e[D, left arrow */
+			return 2;
+		case '1': /* \e[<1,3,4>], may be home, del, end */
+		case '3':
+		case '4':
+			return 0;
+		}
+		break;
+
+	case 4:
+		if (*lastkey == '~') {
+			switch (buf[2]) {
+			case '1': /* \e[1~, home */
+				return 1;
+			case '3': /* \e[3~, del */
+				return 4;
+			case '4': /* \e[4~, end */
+				return 5;
+			}
+		}
+		break;
+	}
+
+	return -1;
+}
+
+/**
+ * kdb_getchar() - Read a single character from a kdb console (or consoles).
+ *
+ * Other than polling the various consoles that are currently enabled,
+ * most of the work done in this function is dealing with escape sequences.
+ *
+ * An escape key could be the start of a vt100 control sequence such as \e[D
+ * (left arrow) or it could be a character in its own right.  The standard
+ * method for detecting the difference is to wait for 2 seconds to see if there
+ * are any other characters.  kdb is complicated by the lack of a timer service
+ * (interrupts are off), by multiple input sources. Escape sequence processing
+ * has to be done as states in the polling loop.
+ *
+ * Return: The key pressed or a control code derived from an escape sequence.
+ */
+char kdb_getchar(void)
 {
 #define ESCAPE_UDELAY 1000
 #define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
-	char escape_data[5];	/* longest vt100 escape sequence is 4 bytes */
-	char *ped = escape_data;
+	char buf[4];	/* longest vt100 escape sequence is 4 bytes */
+	char *pbuf = buf;
 	int escape_delay = 0;
-	get_char_func *f, *f_escape = NULL;
+	get_char_func *f, *f_prev = NULL;
 	int key;
 
 	for (f = &kdb_poll_funcs[0]; ; ++f) {
@@ -65,109 +139,37 @@
 			touch_nmi_watchdog();
 			f = &kdb_poll_funcs[0];
 		}
-		if (escape_delay == 2) {
-			*ped = '\0';
-			ped = escape_data;
-			--escape_delay;
-		}
-		if (escape_delay == 1) {
-			key = *ped++;
-			if (!*ped)
-				--escape_delay;
-			break;
-		}
+
 		key = (*f)();
 		if (key == -1) {
 			if (escape_delay) {
 				udelay(ESCAPE_UDELAY);
-				--escape_delay;
+				if (--escape_delay == 0)
+					return '\e';
 			}
 			continue;
 		}
-		if (bufsize <= 2) {
-			if (key == '\r')
-				key = '\n';
-			*buffer++ = key;
-			*buffer = '\0';
-			return -1;
-		}
-		if (escape_delay == 0 && key == '\e') {
+
+		/*
+		 * When the first character is received (or we get a change
+		 * input source) we set ourselves up to handle an escape
+		 * sequences (just in case).
+		 */
+		if (f_prev != f) {
+			f_prev = f;
+			pbuf = buf;
 			escape_delay = ESCAPE_DELAY;
-			ped = escape_data;
-			f_escape = f;
 		}
-		if (escape_delay) {
-			*ped++ = key;
-			if (f_escape != f) {
-				escape_delay = 2;
-				continue;
-			}
-			if (ped - escape_data == 1) {
-				/* \e */
-				continue;
-			} else if (ped - escape_data == 2) {
-				/* \e<something> */
-				if (key != '[')
-					escape_delay = 2;
-				continue;
-			} else if (ped - escape_data == 3) {
-				/* \e[<something> */
-				int mapkey = 0;
-				switch (key) {
-				case 'A': /* \e[A, up arrow */
-					mapkey = 16;
-					break;
-				case 'B': /* \e[B, down arrow */
-					mapkey = 14;
-					break;
-				case 'C': /* \e[C, right arrow */
-					mapkey = 6;
-					break;
-				case 'D': /* \e[D, left arrow */
-					mapkey = 2;
-					break;
-				case '1': /* dropthrough */
-				case '3': /* dropthrough */
-				/* \e[<1,3,4>], may be home, del, end */
-				case '4':
-					mapkey = -1;
-					break;
-				}
-				if (mapkey != -1) {
-					if (mapkey > 0) {
-						escape_data[0] = mapkey;
-						escape_data[1] = '\0';
-					}
-					escape_delay = 2;
-				}
-				continue;
-			} else if (ped - escape_data == 4) {
-				/* \e[<1,3,4><something> */
-				int mapkey = 0;
-				if (key == '~') {
-					switch (escape_data[2]) {
-					case '1': /* \e[1~, home */
-						mapkey = 1;
-						break;
-					case '3': /* \e[3~, del */
-						mapkey = 4;
-						break;
-					case '4': /* \e[4~, end */
-						mapkey = 5;
-						break;
-					}
-				}
-				if (mapkey > 0) {
-					escape_data[0] = mapkey;
-					escape_data[1] = '\0';
-				}
-				escape_delay = 2;
-				continue;
-			}
-		}
-		break;	/* A key to process */
+
+		*pbuf++ = key;
+		key = kdb_handle_escape(buf, pbuf - buf);
+		if (key < 0) /* no escape sequence; return best character */
+			return buf[pbuf - buf == 2 ? 1 : 0];
+		if (key > 0)
+			return key;
 	}
-	return key;
+
+	unreachable();
 }
 
 /*
@@ -188,17 +190,7 @@
  *	function.  It is not reentrant - it relies on the fact
  *	that while kdb is running on only one "master debug" cpu.
  * Remarks:
- *
- * The buffer size must be >= 2.  A buffer size of 2 means that the caller only
- * wants a single key.
- *
- * An escape key could be the start of a vt100 control sequence such as \e[D
- * (left arrow) or it could be a character in its own right.  The standard
- * method for detecting the difference is to wait for 2 seconds to see if there
- * are any other characters.  kdb is complicated by the lack of a timer service
- * (interrupts are off), by multiple input sources and by the need to sometimes
- * return after just one key.  Escape sequence processing has to be done as
- * states in the polling loop.
+ *	The buffer size must be >= 2.
  */
 
 static char *kdb_read(char *buffer, size_t bufsize)
@@ -233,9 +225,7 @@
 	*cp = '\0';
 	kdb_printf("%s", buffer);
 poll_again:
-	key = kdb_read_get_key(buffer, bufsize);
-	if (key == -1)
-		return buffer;
+	key = kdb_getchar();
 	if (key != 9)
 		tab = 0;
 	switch (key) {
@@ -552,6 +542,44 @@
 	return 0;
 }
 
+static void kdb_msg_write(const char *msg, int msg_len)
+{
+	struct console *c;
+	const char *cp;
+	int len;
+
+	if (msg_len == 0)
+		return;
+
+	cp = msg;
+	len = msg_len;
+
+	while (len--) {
+		dbg_io_ops->write_char(*cp);
+		cp++;
+	}
+
+	for_each_console(c) {
+		if (!(c->flags & CON_ENABLED))
+			continue;
+		if (c == dbg_io_ops->cons)
+			continue;
+		/*
+		 * Set oops_in_progress to encourage the console drivers to
+		 * disregard their internal spin locks: in the current calling
+		 * context the risk of deadlock is a bigger problem than risks
+		 * due to re-entering the console driver. We operate directly on
+		 * oops_in_progress rather than using bust_spinlocks() because
+		 * the calls bust_spinlocks() makes on exit are not appropriate
+		 * for this calling context.
+		 */
+		++oops_in_progress;
+		c->write(c, msg, msg_len);
+		--oops_in_progress;
+		touch_nmi_watchdog();
+	}
+}
+
 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 {
 	int diag;
@@ -563,8 +591,7 @@
 	int this_cpu, old_cpu;
 	char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
 	char *moreprompt = "more> ";
-	struct console *c = console_drivers;
-	unsigned long uninitialized_var(flags);
+	unsigned long flags;
 
 	/* Serialize kdb_printf if multiple cpus try to write at once.
 	 * But if any cpu goes recursive in kdb, just print the output,
@@ -701,23 +728,11 @@
 	 */
 	retlen = strlen(kdb_buffer);
 	cp = (char *) printk_skip_headers(kdb_buffer);
-	if (!dbg_kdb_mode && kgdb_connected) {
+	if (!dbg_kdb_mode && kgdb_connected)
 		gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
-	} else {
-		if (dbg_io_ops && !dbg_io_ops->is_console) {
-			len = retlen - (cp - kdb_buffer);
-			cp2 = cp;
-			while (len--) {
-				dbg_io_ops->write_char(*cp2);
-				cp2++;
-			}
-		}
-		while (c) {
-			c->write(c, cp, retlen - (cp - kdb_buffer));
-			touch_nmi_watchdog();
-			c = c->next;
-		}
-	}
+	else
+		kdb_msg_write(cp, retlen - (cp - kdb_buffer));
+
 	if (logging) {
 		saved_loglevel = console_loglevel;
 		console_loglevel = CONSOLE_LOGLEVEL_SILENT;
@@ -750,7 +765,7 @@
 
 	/* check for having reached the LINES number of printed lines */
 	if (kdb_nextline >= linecount) {
-		char buf1[16] = "";
+		char ch;
 
 		/* Watch out for recursion here.  Any routine that calls
 		 * kdb_printf will come back through here.  And kdb_read
@@ -766,58 +781,43 @@
 			moreprompt = "more> ";
 
 		kdb_input_flush();
-		c = console_drivers;
-
-		if (dbg_io_ops && !dbg_io_ops->is_console) {
-			len = strlen(moreprompt);
-			cp = moreprompt;
-			while (len--) {
-				dbg_io_ops->write_char(*cp);
-				cp++;
-			}
-		}
-		while (c) {
-			c->write(c, moreprompt, strlen(moreprompt));
-			touch_nmi_watchdog();
-			c = c->next;
-		}
+		kdb_msg_write(moreprompt, strlen(moreprompt));
 
 		if (logging)
 			printk("%s", moreprompt);
 
-		kdb_read(buf1, 2); /* '2' indicates to return
-				    * immediately after getting one key. */
+		ch = kdb_getchar();
 		kdb_nextline = 1;	/* Really set output line 1 */
 
 		/* empty and reset the buffer: */
 		kdb_buffer[0] = '\0';
 		next_avail = kdb_buffer;
 		size_avail = sizeof(kdb_buffer);
-		if ((buf1[0] == 'q') || (buf1[0] == 'Q')) {
+		if ((ch == 'q') || (ch == 'Q')) {
 			/* user hit q or Q */
 			KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
 			KDB_STATE_CLEAR(PAGER);
 			/* end of command output; back to normal mode */
 			kdb_grepping_flag = 0;
 			kdb_printf("\n");
-		} else if (buf1[0] == ' ') {
+		} else if (ch == ' ') {
 			kdb_printf("\r");
 			suspend_grep = 1; /* for this recursion */
-		} else if (buf1[0] == '\n') {
+		} else if (ch == '\n' || ch == '\r') {
 			kdb_nextline = linecount - 1;
 			kdb_printf("\r");
 			suspend_grep = 1; /* for this recursion */
-		} else if (buf1[0] == '/' && !kdb_grepping_flag) {
+		} else if (ch == '/' && !kdb_grepping_flag) {
 			kdb_printf("\r");
 			kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
 				   kdbgetenv("SEARCHPROMPT") ?: "search> ");
 			*strchrnul(kdb_grep_string, '\n') = '\0';
 			kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
 			suspend_grep = 1; /* for this recursion */
-		} else if (buf1[0] && buf1[0] != '\n') {
-			/* user hit something other than enter */
+		} else if (ch) {
+			/* user hit something unexpected */
 			suspend_grep = 1; /* for this recursion */
-			if (buf1[0] != '/')
+			if (ch != '/')
 				kdb_printf(
 				    "\nOnly 'q', 'Q' or '/' are processed at "
 				    "more prompt, input ignored\n");
diff --git a/kernel/debug/kdb/kdb_keyboard.c b/kernel/debug/kdb/kdb_keyboard.c
index 750497b..f877a0a 100644
--- a/kernel/debug/kdb/kdb_keyboard.c
+++ b/kernel/debug/kdb/kdb_keyboard.c
@@ -173,11 +173,11 @@
 	case KT_LATIN:
 		if (isprint(keychar))
 			break;		/* printable characters */
-		/* fall through */
+		fallthrough;
 	case KT_SPEC:
 		if (keychar == K_ENTER)
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		return -1;	/* ignore unprintables */
 	}
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 4567fe9..930ac1b 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -62,7 +62,7 @@
 /*
  * Kernel debugger state flags
  */
-int kdb_flags;
+unsigned int kdb_flags;
 
 /*
  * kdb_lock protects updates to kdb_initial_cpu.  Used to
@@ -73,7 +73,6 @@
 int kdb_state;			/* General KDB state */
 
 struct task_struct *kdb_current_task;
-EXPORT_SYMBOL(kdb_current_task);
 struct pt_regs *kdb_current_regs;
 
 const char *kdb_diemsg;
@@ -400,6 +399,13 @@
 		return KDB_ARGCOUNT;
 
 	/*
+	 * Censor sensitive variables
+	 */
+	if (strcmp(argv[1], "PROMPT") == 0 &&
+	    !kdb_check_flags(KDB_ENABLE_MEM_READ, kdb_cmd_enabled, false))
+		return KDB_NOPERM;
+
+	/*
 	 * Check for internal variables
 	 */
 	if (strcmp(argv[1], "KDBDEBUG") == 0) {
@@ -412,8 +418,7 @@
 				    argv[2]);
 			return 0;
 		}
-		kdb_flags = (kdb_flags &
-			     ~(KDB_DEBUG_FLAG_MASK << KDB_DEBUG_FLAG_SHIFT))
+		kdb_flags = (kdb_flags & ~KDB_DEBUG(MASK))
 			| (debugflags << KDB_DEBUG_FLAG_SHIFT);
 
 		return 0;
@@ -1102,13 +1107,14 @@
 	switch (*cmd) {
 	case CTRL_P:
 		if (cmdptr != cmd_tail)
-			cmdptr = (cmdptr-1) % KDB_CMD_HISTORY_COUNT;
-		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
+			cmdptr = (cmdptr + KDB_CMD_HISTORY_COUNT - 1) %
+				 KDB_CMD_HISTORY_COUNT;
+		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
 		return 1;
 	case CTRL_N:
 		if (cmdptr != cmd_head)
 			cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT;
-		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
+		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
 		return 1;
 	}
 	return 0;
@@ -1139,7 +1145,7 @@
 	console_loglevel = old_lvl;
 }
 
-void kdb_set_current_task(struct task_struct *p)
+static void kdb_set_current_task(struct task_struct *p)
 {
 	kdb_current_task = p;
 
@@ -1299,12 +1305,9 @@
 		*(cmd_hist[cmd_head]) = '\0';
 
 do_full_getstr:
-#if defined(CONFIG_SMP)
+		/* PROMPT can only be set if we have MEM_READ permission. */
 		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
 			 raw_smp_processor_id());
-#else
-		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"));
-#endif
 		if (defcmd_in_progress)
 			strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
 
@@ -1315,7 +1318,7 @@
 		if (*cmdbuf != '\n') {
 			if (*cmdbuf < 32) {
 				if (cmdptr == cmd_head) {
-					strncpy(cmd_hist[cmd_head], cmd_cur,
+					strscpy(cmd_hist[cmd_head], cmd_cur,
 						CMD_BUFLEN);
 					*(cmd_hist[cmd_head] +
 					  strlen(cmd_hist[cmd_head])-1) = '\0';
@@ -1325,7 +1328,7 @@
 				cmdbuf = cmd_cur;
 				goto do_full_getstr;
 			} else {
-				strncpy(cmd_hist[cmd_head], cmd_cur,
+				strscpy(cmd_hist[cmd_head], cmd_cur,
 					CMD_BUFLEN);
 			}
 
@@ -2078,7 +2081,8 @@
 	}
 
 	if (KDB_DEBUG(MASK))
-		kdb_printf("KDBFLAGS=0x%x\n", kdb_flags);
+		kdb_printf("KDBDEBUG=0x%x\n",
+			(kdb_flags & KDB_DEBUG(MASK)) >> KDB_DEBUG_FLAG_SHIFT);
 
 	return 0;
 }
@@ -2295,10 +2299,10 @@
 		if (kdb_task_state(p, mask_I))
 			++idle;
 	}
-	kdb_do_each_thread(g, p) {
+	for_each_process_thread(g, p) {
 		if (kdb_task_state(p, mask_M))
 			++daemon;
-	} kdb_while_each_thread(g, p);
+	}
 	if (idle || daemon) {
 		if (idle)
 			kdb_printf("%d idle process%s (state I)%s\n",
@@ -2322,7 +2326,8 @@
 	int cpu;
 	unsigned long tmp;
 
-	if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
+	if (!p ||
+	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
 		return;
 
 	cpu = kdb_process_cpu(p);
@@ -2365,12 +2370,12 @@
 	}
 	kdb_printf("\n");
 	/* Now the real tasks */
-	kdb_do_each_thread(g, p) {
+	for_each_process_thread(g, p) {
 		if (KDB_FLAG(CMD_INTERRUPT))
 			return 0;
 		if (kdb_task_state(p, mask))
 			kdb_ps1(p);
-	} kdb_while_each_thread(g, p);
+	}
 
 	return 0;
 }
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index ad53b19..8187421 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -210,6 +210,7 @@
 extern void kdb_print_nameval(const char *name, unsigned long val);
 extern void kdb_send_sig(struct task_struct *p, int sig);
 extern void kdb_meminfo_proc_show(void);
+extern char kdb_getchar(void);
 extern char *kdb_getstr(char *, size_t, const char *);
 extern void kdb_gdb_state_pass(char *buf);
 
@@ -229,18 +230,14 @@
 
 #define kdb_task_has_cpu(p) (task_curr(p))
 
-/* Simplify coexistence with NPTL */
-#define	kdb_do_each_thread(g, p) do_each_thread(g, p)
-#define	kdb_while_each_thread(g, p) while_each_thread(g, p)
-
 #define GFP_KDB (in_dbg_master() ? GFP_ATOMIC : GFP_KERNEL)
 
 extern void *debug_kmalloc(size_t size, gfp_t flags);
 extern void debug_kfree(void *);
 extern void debug_kusage(void);
 
-extern void kdb_set_current_task(struct task_struct *);
 extern struct task_struct *kdb_current_task;
+extern struct pt_regs *kdb_current_regs;
 
 #ifdef CONFIG_KDB_KEYBOARD
 extern void kdb_kbd_cleanup_state(void);
diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
index b8e6306..6226502 100644
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -325,7 +325,7 @@
  */
 int kdb_getarea_size(void *res, unsigned long addr, size_t size)
 {
-	int ret = probe_kernel_read((char *)res, (char *)addr, size);
+	int ret = copy_from_kernel_nofault((char *)res, (char *)addr, size);
 	if (ret) {
 		if (!KDB_STATE(SUPPRESS)) {
 			kdb_printf("kdb_getarea: Bad address 0x%lx\n", addr);
@@ -350,7 +350,7 @@
  */
 int kdb_putarea_size(unsigned long addr, void *res, size_t size)
 {
-	int ret = probe_kernel_read((char *)addr, (char *)res, size);
+	int ret = copy_from_kernel_nofault((char *)addr, (char *)res, size);
 	if (ret) {
 		if (!KDB_STATE(SUPPRESS)) {
 			kdb_printf("kdb_putarea: Bad address 0x%lx\n", addr);
@@ -432,7 +432,7 @@
 				*word = w8;
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	default:
 		diag = KDB_BADWIDTH;
 		kdb_printf("kdb_getphysword: bad width %ld\n", (long) size);
@@ -481,7 +481,7 @@
 				*word = w8;
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	default:
 		diag = KDB_BADWIDTH;
 		kdb_printf("kdb_getword: bad width %ld\n", (long) size);
@@ -525,7 +525,7 @@
 			diag = kdb_putarea(addr, w8);
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	default:
 		diag = KDB_BADWIDTH;
 		kdb_printf("kdb_putword: bad width %ld\n", (long) size);
@@ -624,7 +624,8 @@
 	char state;
 	unsigned long tmp;
 
-	if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
+	if (!p ||
+	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
 		return 'E';
 
 	cpu = kdb_process_cpu(p);
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 73c5c2b..c99de4a 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -1,10 +1,25 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+config NO_DMA
+	bool
+
 config HAS_DMA
 	bool
 	depends on !NO_DMA
 	default y
 
+config DMA_OPS
+	depends on HAS_DMA
+	bool
+
+#
+# IOMMU drivers that can bypass the IOMMU code and optionally use the direct
+# mapping fast path should select this option and set the dma_ops_bypass
+# flag in struct device where applicable
+#
+config DMA_OPS_BYPASS
+	bool
+
 config NEED_SG_DMA_LENGTH
 	bool
 
@@ -29,6 +44,12 @@
 config ARCH_HAS_DMA_WRITE_COMBINE
 	bool
 
+#
+# Select if the architectures provides the arch_dma_mark_clean hook
+#
+config ARCH_HAS_DMA_MARK_CLEAN
+	bool
+
 config DMA_DECLARE_COHERENT
 	bool
 
@@ -51,31 +72,40 @@
 config ARCH_HAS_DMA_PREP_COHERENT
 	bool
 
-config ARCH_HAS_DMA_COHERENT_TO_PFN
-	bool
-
 config ARCH_HAS_FORCE_DMA_UNENCRYPTED
 	bool
 
-config DMA_NONCOHERENT_CACHE_SYNC
-	bool
-
 config DMA_VIRT_OPS
 	bool
 	depends on HAS_DMA
+	select DMA_OPS
 
 config SWIOTLB
 	bool
 	select NEED_DMA_MAP_STATE
 
-config DMA_REMAP
-	depends on MMU
+#
+# Should be selected if we can mmap non-coherent mappings to userspace.
+# The only thing that is really required is a way to set an uncached bit
+# in the pagetables
+#
+config DMA_NONCOHERENT_MMAP
+	default y if !MMU
+	bool
+
+config DMA_COHERENT_POOL
 	select GENERIC_ALLOCATOR
 	bool
 
+config DMA_REMAP
+	bool
+	depends on MMU
+	select DMA_NONCOHERENT_MMAP
+
 config DMA_DIRECT_REMAP
 	bool
 	select DMA_REMAP
+	select DMA_COHERENT_POOL
 
 config DMA_CMA
 	bool "DMA Contiguous Memory Allocator"
@@ -88,10 +118,21 @@
 	  You can disable CMA by specifying "cma=0" on the kernel's command
 	  line.
 
-	  For more information see <include/linux/dma-contiguous.h>.
+	  For more information see <kernel/dma/contiguous.c>.
 	  If unsure, say "n".
 
 if  DMA_CMA
+
+config DMA_PERNUMA_CMA
+	bool "Enable separate DMA Contiguous Memory Area for each NUMA Node"
+	default NUMA && ARM64
+	help
+	  Enable this option to get pernuma CMA areas so that devices like
+	  ARM64 SMMU can get local memory by DMA coherent APIs.
+
+	  You can set the size of pernuma CMA by specifying "cma_pernuma=size"
+	  on the kernel's command line.
+
 comment "Default contiguous memory area size:"
 
 config CMA_SIZE_MBYTES
@@ -136,7 +177,7 @@
 
 config CMA_ALIGNMENT
 	int "Maximum PAGE_SIZE order of alignment for contiguous buffers"
-	range 4 12
+	range 2 12
 	default 8
 	help
 	  DMA mapping framework by default aligns all buffers to the smallest
@@ -163,11 +204,6 @@
 	  drivers like double-freeing of DMA mappings or freeing mappings that
 	  were never allocated.
 
-	  This also attempts to catch cases where a page owned by DMA is
-	  accessed by the cpu in a way that could cause data corruption.  For
-	  example, this enables cow_user_page() to check that the source page is
-	  not undergoing DMA.
-
 	  This option causes a performance degradation.  Use only if you want to
 	  debug device drivers and dma interactions.
 
diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile
index d237cf3..dc755ab 100644
--- a/kernel/dma/Makefile
+++ b/kernel/dma/Makefile
@@ -1,9 +1,12 @@
 # SPDX-License-Identifier: GPL-2.0
 
-obj-$(CONFIG_HAS_DMA)			+= mapping.o direct.o dummy.o
+obj-$(CONFIG_HAS_DMA)			+= mapping.o direct.o
+obj-$(CONFIG_DMA_OPS)			+= ops_helpers.o
+obj-$(CONFIG_DMA_OPS)			+= dummy.o
 obj-$(CONFIG_DMA_CMA)			+= contiguous.o
 obj-$(CONFIG_DMA_DECLARE_COHERENT)	+= coherent.o
 obj-$(CONFIG_DMA_VIRT_OPS)		+= virt.o
 obj-$(CONFIG_DMA_API_DEBUG)		+= debug.o
 obj-$(CONFIG_SWIOTLB)			+= swiotlb.o
+obj-$(CONFIG_DMA_COHERENT_POOL)		+= pool.o
 obj-$(CONFIG_DMA_REMAP)			+= remap.o
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index 2a0c498..5b5b6c7 100644
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -7,7 +7,8 @@
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
+#include <linux/dma-map-ops.h>
 
 struct dma_coherent_mem {
 	void		*virt_base;
@@ -32,9 +33,8 @@
 					     struct dma_coherent_mem * mem)
 {
 	if (mem->use_dev_dma_pfn_offset)
-		return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
-	else
-		return mem->device_base;
+		return phys_to_dma(dev, PFN_PHYS(mem->pfn_base));
+	return mem->device_base;
 }
 
 static int dma_init_coherent_memory(phys_addr_t phys_addr,
@@ -107,6 +107,23 @@
 	return 0;
 }
 
+/*
+ * Declare a region of memory to be handed out by dma_alloc_coherent() when it
+ * is asked for coherent memory for this device.  This shall only be used
+ * from platform code, usually based on the device tree description.
+ * 
+ * phys_addr is the CPU physical address to which the memory is currently
+ * assigned (this will be ioremapped so the CPU can access the region).
+ *
+ * device_addr is the DMA address the device needs to be programmed with to
+ * actually address this memory (this will be handed out as the dma_addr_t in
+ * dma_alloc_coherent()).
+ *
+ * size is the size of the area (must be a multiple of PAGE_SIZE).
+ *
+ * As a simplification for the platforms, only *one* such region of memory may
+ * be declared per device.
+ */
 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
 				dma_addr_t device_addr, size_t size)
 {
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 69cfb43..16b95ff 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -5,6 +5,34 @@
  * Written by:
  *	Marek Szyprowski <m.szyprowski@samsung.com>
  *	Michal Nazarewicz <mina86@mina86.com>
+ *
+ * Contiguous Memory Allocator
+ *
+ *   The Contiguous Memory Allocator (CMA) makes it possible to
+ *   allocate big contiguous chunks of memory after the system has
+ *   booted.
+ *
+ * Why is it needed?
+ *
+ *   Various devices on embedded systems have no scatter-getter and/or
+ *   IO map support and require contiguous blocks of memory to
+ *   operate.  They include devices such as cameras, hardware video
+ *   coders, etc.
+ *
+ *   Such devices often require big memory buffers (a full HD frame
+ *   is, for instance, more then 2 mega pixels large, i.e. more than 6
+ *   MB of memory), which makes mechanisms such as kmalloc() or
+ *   alloc_page() ineffective.
+ *
+ *   At the same time, a solution where a big memory region is
+ *   reserved for a device is suboptimal since often more memory is
+ *   reserved then strictly required and, moreover, the memory is
+ *   inaccessible to page system even if device drivers don't use it.
+ *
+ *   CMA tries to solve this issue by operating on memory regions
+ *   where only movable pages can be allocated from.  This way, kernel
+ *   can use the memory for pagecache and when device driver requests
+ *   it, allocated pages can be migrated.
  */
 
 #define pr_fmt(fmt) "cma: " fmt
@@ -16,12 +44,11 @@
 #endif
 
 #include <asm/page.h>
-#include <asm/dma-contiguous.h>
 
 #include <linux/memblock.h>
 #include <linux/err.h>
 #include <linux/sizes.h>
-#include <linux/dma-contiguous.h>
+#include <linux/dma-map-ops.h>
 #include <linux/cma.h>
 
 #ifdef CONFIG_CMA_SIZE_MBYTES
@@ -42,10 +69,11 @@
  * Users, who want to set the size of global CMA area for their system
  * should use cma= kernel parameter.
  */
-static const phys_addr_t size_bytes = (phys_addr_t)CMA_SIZE_MBYTES * SZ_1M;
-static phys_addr_t size_cmdline = -1;
-static phys_addr_t base_cmdline;
-static phys_addr_t limit_cmdline;
+static const phys_addr_t size_bytes __initconst =
+	(phys_addr_t)CMA_SIZE_MBYTES * SZ_1M;
+static phys_addr_t  size_cmdline __initdata = -1;
+static phys_addr_t base_cmdline __initdata;
+static phys_addr_t limit_cmdline __initdata;
 
 static int __init early_cma(char *p)
 {
@@ -68,20 +96,24 @@
 }
 early_param("cma", early_cma);
 
+#ifdef CONFIG_DMA_PERNUMA_CMA
+
+static struct cma *dma_contiguous_pernuma_area[MAX_NUMNODES];
+static phys_addr_t pernuma_size_bytes __initdata;
+
+static int __init early_cma_pernuma(char *p)
+{
+	pernuma_size_bytes = memparse(p, &p);
+	return 0;
+}
+early_param("cma_pernuma", early_cma_pernuma);
+#endif
+
 #ifdef CONFIG_CMA_SIZE_PERCENTAGE
 
 static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
 {
-	struct memblock_region *reg;
-	unsigned long total_pages = 0;
-
-	/*
-	 * We cannot use memblock_phys_mem_size() here, because
-	 * memblock_analyze() has not been called yet.
-	 */
-	for_each_memblock(memory, reg)
-		total_pages += memblock_region_memory_end_pfn(reg) -
-			       memblock_region_memory_base_pfn(reg);
+	unsigned long total_pages = PHYS_PFN(memblock_phys_mem_size());
 
 	return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
 }
@@ -95,6 +127,34 @@
 
 #endif
 
+#ifdef CONFIG_DMA_PERNUMA_CMA
+void __init dma_pernuma_cma_reserve(void)
+{
+	int nid;
+
+	if (!pernuma_size_bytes)
+		return;
+
+	for_each_online_node(nid) {
+		int ret;
+		char name[CMA_MAX_NAME];
+		struct cma **cma = &dma_contiguous_pernuma_area[nid];
+
+		snprintf(name, sizeof(name), "pernuma%d", nid);
+		ret = cma_declare_contiguous_nid(0, pernuma_size_bytes, 0, 0,
+						 0, false, name, cma, nid);
+		if (ret) {
+			pr_warn("%s: reservation failed: err %d, node %d", __func__,
+				ret, nid);
+			continue;
+		}
+
+		pr_debug("%s: reserved %llu MiB on node %d\n", __func__,
+			(unsigned long long)pernuma_size_bytes / SZ_1M, nid);
+	}
+}
+#endif
+
 /**
  * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling
  * @limit: End address of the reserved memory (optional, 0 for any).
@@ -142,6 +202,11 @@
 	}
 }
 
+void __weak
+dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
+{
+}
+
 /**
  * dma_contiguous_reserve_area() - reserve custom contiguous area
  * @size: Size of the reserved area (in bytes),
@@ -214,40 +279,58 @@
 	return cma_release(dev_get_cma_area(dev), pages, count);
 }
 
+static struct page *cma_alloc_aligned(struct cma *cma, size_t size, gfp_t gfp)
+{
+	unsigned int align = min(get_order(size), CONFIG_CMA_ALIGNMENT);
+
+	return cma_alloc(cma, size >> PAGE_SHIFT, align, gfp & __GFP_NOWARN);
+}
+
 /**
  * dma_alloc_contiguous() - allocate contiguous pages
  * @dev:   Pointer to device for which the allocation is performed.
  * @size:  Requested allocation size.
  * @gfp:   Allocation flags.
  *
- * This function allocates contiguous memory buffer for specified device. It
- * first tries to use device specific contiguous memory area if available or
- * the default global one, then tries a fallback allocation of normal pages.
+ * tries to use device specific contiguous memory area if available, or it
+ * tries to use per-numa cma, if the allocation fails, it will fallback to
+ * try default global one.
  *
- * Note that it byapss one-page size of allocations from the global area as
- * the addresses within one page are always contiguous, so there is no need
- * to waste CMA pages for that kind; it also helps reduce fragmentations.
+ * Note that it bypass one-page size of allocations from the per-numa and
+ * global area as the addresses within one page are always contiguous, so
+ * there is no need to waste CMA pages for that kind; it also helps reduce
+ * fragmentations.
  */
 struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
 {
-	size_t count = size >> PAGE_SHIFT;
-	struct page *page = NULL;
-	struct cma *cma = NULL;
-
-	if (dev && dev->cma_area)
-		cma = dev->cma_area;
-	else if (count > 1)
-		cma = dma_contiguous_default_area;
+#ifdef CONFIG_DMA_PERNUMA_CMA
+	int nid = dev_to_node(dev);
+#endif
 
 	/* CMA can be used only in the context which permits sleeping */
-	if (cma && gfpflags_allow_blocking(gfp)) {
-		size_t align = get_order(size);
-		size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT);
+	if (!gfpflags_allow_blocking(gfp))
+		return NULL;
+	if (dev->cma_area)
+		return cma_alloc_aligned(dev->cma_area, size, gfp);
+	if (size <= PAGE_SIZE)
+		return NULL;
 
-		page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);
+#ifdef CONFIG_DMA_PERNUMA_CMA
+	if (nid != NUMA_NO_NODE && !(gfp & (GFP_DMA | GFP_DMA32))) {
+		struct cma *cma = dma_contiguous_pernuma_area[nid];
+		struct page *page;
+
+		if (cma) {
+			page = cma_alloc_aligned(cma, size, gfp);
+			if (page)
+				return page;
+		}
 	}
+#endif
+	if (!dma_contiguous_default_area)
+		return NULL;
 
-	return page;
+	return cma_alloc_aligned(dma_contiguous_default_area, size, gfp);
 }
 
 /**
@@ -263,9 +346,27 @@
  */
 void dma_free_contiguous(struct device *dev, struct page *page, size_t size)
 {
-	if (!cma_release(dev_get_cma_area(dev), page,
-			 PAGE_ALIGN(size) >> PAGE_SHIFT))
-		__free_pages(page, get_order(size));
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	/* if dev has its own cma, free page from there */
+	if (dev->cma_area) {
+		if (cma_release(dev->cma_area, page, count))
+			return;
+	} else {
+		/*
+		 * otherwise, page is from either per-numa cma or default cma
+		 */
+#ifdef CONFIG_DMA_PERNUMA_CMA
+		if (cma_release(dma_contiguous_pernuma_area[page_to_nid(page)],
+					page, count))
+			return;
+#endif
+		if (cma_release(dma_contiguous_default_area, page, count))
+			return;
+	}
+
+	/* not in any cma, free from buddy */
+	__free_pages(page, get_order(size));
 }
 
 /*
@@ -281,14 +382,14 @@
 
 static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev)
 {
-	dev_set_cma_area(dev, rmem->priv);
+	dev->cma_area = rmem->priv;
 	return 0;
 }
 
 static void rmem_cma_device_release(struct reserved_mem *rmem,
 				    struct device *dev)
 {
-	dev_set_cma_area(dev, NULL);
+	dev->cma_area = NULL;
 }
 
 static const struct reserved_mem_ops rmem_cma_ops = {
@@ -301,9 +402,16 @@
 	phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
 	phys_addr_t mask = align - 1;
 	unsigned long node = rmem->fdt_node;
+	bool default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
 	struct cma *cma;
 	int err;
 
+	if (size_cmdline != -1 && default_cma) {
+		pr_info("Reserved memory: bypass %s node, using cmdline CMA params instead\n",
+			rmem->name);
+		return -EBUSY;
+	}
+
 	if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
 	    of_get_flat_dt_prop(node, "no-map", NULL))
 		return -EINVAL;
@@ -321,8 +429,8 @@
 	/* Architecture specific contiguous memory fixup. */
 	dma_contiguous_early_fixup(rmem->base, rmem->size);
 
-	if (of_get_flat_dt_prop(node, "linux,cma-default", NULL))
-		dma_contiguous_set_default(cma);
+	if (default_cma)
+		dma_contiguous_default_area = cma;
 
 	rmem->ops = &rmem_cma_ops;
 	rmem->priv = cma;
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 01e893c..10d07ac 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -9,10 +9,9 @@
 
 #include <linux/sched/task_stack.h>
 #include <linux/scatterlist.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
 #include <linux/sched/task.h>
 #include <linux/stacktrace.h>
-#include <linux/dma-debug.h>
 #include <linux/spinlock.h>
 #include <linux/vmalloc.h>
 #include <linux/debugfs.h>
@@ -24,10 +23,10 @@
 #include <linux/ctype.h>
 #include <linux/list.h>
 #include <linux/slab.h>
-
 #include <asm/sections.h>
+#include "debug.h"
 
-#define HASH_SIZE       1024ULL
+#define HASH_SIZE       16384ULL
 #define HASH_FN_SHIFT   13
 #define HASH_FN_MASK    (HASH_SIZE - 1)
 
@@ -54,40 +53,40 @@
  * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
  * @list: node on pre-allocated free_entries list
  * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
- * @type: single, page, sg, coherent
- * @pfn: page frame of the start address
- * @offset: offset of mapping relative to pfn
  * @size: length of the mapping
+ * @type: single, page, sg, coherent
  * @direction: enum dma_data_direction
  * @sg_call_ents: 'nents' from dma_map_sg
  * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
+ * @pfn: page frame of the start address
+ * @offset: offset of mapping relative to pfn
  * @map_err_type: track whether dma_mapping_error() was checked
  * @stacktrace: support backtraces when a violation is detected
  */
 struct dma_debug_entry {
 	struct list_head list;
 	struct device    *dev;
-	int              type;
-	unsigned long	 pfn;
-	size_t		 offset;
 	u64              dev_addr;
 	u64              size;
+	int              type;
 	int              direction;
 	int		 sg_call_ents;
 	int		 sg_mapped_ents;
+	unsigned long	 pfn;
+	size_t		 offset;
 	enum map_err_types  map_err_type;
 #ifdef CONFIG_STACKTRACE
 	unsigned int	stack_len;
 	unsigned long	stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
 #endif
-};
+} ____cacheline_aligned_in_smp;
 
 typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
 
 struct hash_bucket {
 	struct list_head list;
 	spinlock_t lock;
-} ____cacheline_aligned_in_smp;
+};
 
 /* Hash list to save the allocated dma addresses */
 static struct hash_bucket dma_entry_hash[HASH_SIZE];
@@ -144,8 +143,12 @@
 	[dma_debug_resource] = "resource",
 };
 
-static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
-				   "DMA_FROM_DEVICE", "DMA_NONE" };
+static const char *dir2name[] = {
+	[DMA_BIDIRECTIONAL]	= "DMA_BIDIRECTIONAL",
+	[DMA_TO_DEVICE]		= "DMA_TO_DEVICE",
+	[DMA_FROM_DEVICE]	= "DMA_FROM_DEVICE",
+	[DMA_NONE]		= "DMA_NONE",
+};
 
 /*
  * The access to some variables in this macro is racy. We can't use atomic_t
@@ -164,7 +167,7 @@
 {
 #ifdef CONFIG_STACKTRACE
 	if (entry) {
-		pr_warning("Mapped at:\n");
+		pr_warn("Mapped at:\n");
 		stack_trace_print(entry->stack_entries, entry->stack_len, 0);
 	}
 #endif
@@ -258,12 +261,10 @@
  * Give up exclusive access to the hash bucket
  */
 static void put_hash_bucket(struct hash_bucket *bucket,
-			    unsigned long *flags)
+			    unsigned long flags)
 	__releases(&bucket->lock)
 {
-	unsigned long __flags = *flags;
-
-	spin_unlock_irqrestore(&bucket->lock, __flags);
+	spin_unlock_irqrestore(&bucket->lock, flags);
 }
 
 static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
@@ -362,7 +363,7 @@
 		/*
 		 * Nothing found, go back a hash bucket
 		 */
-		put_hash_bucket(*bucket, flags);
+		put_hash_bucket(*bucket, *flags);
 		range          += (1 << HASH_FN_SHIFT);
 		index.dev_addr -= (1 << HASH_FN_SHIFT);
 		*bucket = get_hash_bucket(&index, flags);
@@ -446,9 +447,6 @@
  * dma_active_cacheline entry to track per event.  dma_map_sg(), on the
  * other hand, consumes a single dma_debug_entry, but inserts 'nents'
  * entries into the tree.
- *
- * At any time debug_dma_assert_idle() can be called to trigger a
- * warning if any cachelines in the given page are in the active set.
  */
 static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
 static DEFINE_SPINLOCK(radix_lock);
@@ -495,10 +493,7 @@
 	overlap = active_cacheline_set_overlap(cln, ++overlap);
 
 	/* If we overflowed the overlap counter then we're potentially
-	 * leaking dma-mappings.  Otherwise, if maps and unmaps are
-	 * balanced then this overflow may cause false negatives in
-	 * debug_dma_assert_idle() as the cacheline may be marked idle
-	 * prematurely.
+	 * leaking dma-mappings.
 	 */
 	WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
 		  pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
@@ -553,53 +548,6 @@
 	spin_unlock_irqrestore(&radix_lock, flags);
 }
 
-/**
- * debug_dma_assert_idle() - assert that a page is not undergoing dma
- * @page: page to lookup in the dma_active_cacheline tree
- *
- * Place a call to this routine in cases where the cpu touching the page
- * before the dma completes (page is dma_unmapped) will lead to data
- * corruption.
- */
-void debug_dma_assert_idle(struct page *page)
-{
-	static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
-	struct dma_debug_entry *entry = NULL;
-	void **results = (void **) &ents;
-	unsigned int nents, i;
-	unsigned long flags;
-	phys_addr_t cln;
-
-	if (dma_debug_disabled())
-		return;
-
-	if (!page)
-		return;
-
-	cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
-	spin_lock_irqsave(&radix_lock, flags);
-	nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
-				       CACHELINES_PER_PAGE);
-	for (i = 0; i < nents; i++) {
-		phys_addr_t ent_cln = to_cacheline_number(ents[i]);
-
-		if (ent_cln == cln) {
-			entry = ents[i];
-			break;
-		} else if (ent_cln >= cln + CACHELINES_PER_PAGE)
-			break;
-	}
-	spin_unlock_irqrestore(&radix_lock, flags);
-
-	if (!entry)
-		return;
-
-	cln = to_cacheline_number(entry);
-	err_printk(entry->dev, entry,
-		   "cpu touching an active dma mapped cacheline [cln=%pa]\n",
-		   &cln);
-}
-
 /*
  * Wrapper function for adding an entry to the hash.
  * This function takes care of locking itself.
@@ -612,7 +560,7 @@
 
 	bucket = get_hash_bucket(entry, &flags);
 	hash_bucket_add(bucket, entry);
-	put_hash_bucket(bucket, &flags);
+	put_hash_bucket(bucket, flags);
 
 	rc = active_cacheline_insert(entry);
 	if (rc == -ENOMEM) {
@@ -658,7 +606,7 @@
 	return entry;
 }
 
-void __dma_entry_alloc_check_leak(void)
+static void __dma_entry_alloc_check_leak(void)
 {
 	u32 tmp = nr_total_entries % nr_prealloc_entries;
 
@@ -887,7 +835,7 @@
 static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
 {
 	struct device *dev = data;
-	struct dma_debug_entry *uninitialized_var(entry);
+	struct dma_debug_entry *entry;
 	int count;
 
 	if (dma_debug_disabled())
@@ -1006,7 +954,7 @@
 
 	if (!entry) {
 		/* must drop lock before calling dma_mapping_error */
-		put_hash_bucket(bucket, &flags);
+		put_hash_bucket(bucket, flags);
 
 		if (dma_mapping_error(ref->dev, ref->dev_addr)) {
 			err_printk(ref->dev, NULL,
@@ -1074,7 +1022,7 @@
 	/*
 	 * Drivers should use dma_mapping_error() to check the returned
 	 * addresses of dma_map_single() and dma_map_page().
-	 * If not, print this warning message. See Documentation/DMA-API.txt.
+	 * If not, print this warning message. See Documentation/core-api/dma-api.rst.
 	 */
 	if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
 		err_printk(ref->dev, entry,
@@ -1088,7 +1036,7 @@
 	hash_bucket_del(entry);
 	dma_entry_free(entry);
 
-	put_hash_bucket(bucket, &flags);
+	put_hash_bucket(bucket, flags);
 }
 
 static void check_for_stack(struct device *dev,
@@ -1208,7 +1156,7 @@
 	}
 
 out:
-	put_hash_bucket(bucket, &flags);
+	put_hash_bucket(bucket, flags);
 }
 
 static void check_sg_segment(struct device *dev, struct scatterlist *sg)
@@ -1271,7 +1219,7 @@
 	entry->dev       = dev;
 	entry->type      = dma_debug_single;
 	entry->pfn	 = page_to_pfn(page);
-	entry->offset	 = offset,
+	entry->offset	 = offset;
 	entry->dev_addr  = dma_addr;
 	entry->size      = size;
 	entry->direction = direction;
@@ -1287,7 +1235,6 @@
 
 	add_dma_entry(entry);
 }
-EXPORT_SYMBOL(debug_dma_map_page);
 
 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
@@ -1323,7 +1270,7 @@
 		}
 	}
 
-	put_hash_bucket(bucket, &flags);
+	put_hash_bucket(bucket, flags);
 }
 EXPORT_SYMBOL(debug_dma_mapping_error);
 
@@ -1342,7 +1289,6 @@
 		return;
 	check_unmap(&ref);
 }
-EXPORT_SYMBOL(debug_dma_unmap_page);
 
 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
 		      int nents, int mapped_ents, int direction)
@@ -1354,6 +1300,12 @@
 	if (unlikely(dma_debug_disabled()))
 		return;
 
+	for_each_sg(sg, s, nents, i) {
+		check_for_stack(dev, sg_page(s), s->offset);
+		if (!PageHighMem(sg_page(s)))
+			check_for_illegal_area(dev, sg_virt(s), s->length);
+	}
+
 	for_each_sg(sg, s, mapped_ents, i) {
 		entry = dma_entry_alloc();
 		if (!entry)
@@ -1362,25 +1314,18 @@
 		entry->type           = dma_debug_sg;
 		entry->dev            = dev;
 		entry->pfn	      = page_to_pfn(sg_page(s));
-		entry->offset	      = s->offset,
+		entry->offset	      = s->offset;
 		entry->size           = sg_dma_len(s);
 		entry->dev_addr       = sg_dma_address(s);
 		entry->direction      = direction;
 		entry->sg_call_ents   = nents;
 		entry->sg_mapped_ents = mapped_ents;
 
-		check_for_stack(dev, sg_page(s), s->offset);
-
-		if (!PageHighMem(sg_page(s))) {
-			check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
-		}
-
 		check_sg_segment(dev, s);
 
 		add_dma_entry(entry);
 	}
 }
-EXPORT_SYMBOL(debug_dma_map_sg);
 
 static int get_nr_mapped_entries(struct device *dev,
 				 struct dma_debug_entry *ref)
@@ -1396,7 +1341,7 @@
 
 	if (entry)
 		mapped_ents = entry->sg_mapped_ents;
-	put_hash_bucket(bucket, &flags);
+	put_hash_bucket(bucket, flags);
 
 	return mapped_ents;
 }
@@ -1432,7 +1377,6 @@
 		check_unmap(&ref);
 	}
 }
-EXPORT_SYMBOL(debug_dma_unmap_sg);
 
 void debug_dma_alloc_coherent(struct device *dev, size_t size,
 			      dma_addr_t dma_addr, void *virt)
@@ -1518,7 +1462,6 @@
 
 	add_dma_entry(entry);
 }
-EXPORT_SYMBOL(debug_dma_map_resource);
 
 void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
 			      size_t size, int direction)
@@ -1536,7 +1479,6 @@
 
 	check_unmap(&ref);
 }
-EXPORT_SYMBOL(debug_dma_unmap_resource);
 
 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 				   size_t size, int direction)
@@ -1555,7 +1497,6 @@
 
 	check_sync(dev, &ref, true);
 }
-EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
 
 void debug_dma_sync_single_for_device(struct device *dev,
 				      dma_addr_t dma_handle, size_t size,
@@ -1575,7 +1516,6 @@
 
 	check_sync(dev, &ref, false);
 }
-EXPORT_SYMBOL(debug_dma_sync_single_for_device);
 
 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 			       int nelems, int direction)
@@ -1608,7 +1548,6 @@
 		check_sync(dev, &ref, true);
 	}
 }
-EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
 
 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 				  int nelems, int direction)
@@ -1640,7 +1579,6 @@
 		check_sync(dev, &ref, false);
 	}
 }
-EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
 
 static int __init dma_debug_driver_setup(char *str)
 {
diff --git a/kernel/dma/debug.h b/kernel/dma/debug.h
new file mode 100644
index 0000000..83643b3
--- /dev/null
+++ b/kernel/dma/debug.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2008 Advanced Micro Devices, Inc.
+ *
+ * Author: Joerg Roedel <joerg.roedel@amd.com>
+ */
+
+#ifndef _KERNEL_DMA_DEBUG_H
+#define _KERNEL_DMA_DEBUG_H
+
+#ifdef CONFIG_DMA_API_DEBUG
+extern void debug_dma_map_page(struct device *dev, struct page *page,
+			       size_t offset, size_t size,
+			       int direction, dma_addr_t dma_addr);
+
+extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
+				 size_t size, int direction);
+
+extern void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
+			     int nents, int mapped_ents, int direction);
+
+extern void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
+			       int nelems, int dir);
+
+extern void debug_dma_alloc_coherent(struct device *dev, size_t size,
+				     dma_addr_t dma_addr, void *virt);
+
+extern void debug_dma_free_coherent(struct device *dev, size_t size,
+				    void *virt, dma_addr_t addr);
+
+extern void debug_dma_map_resource(struct device *dev, phys_addr_t addr,
+				   size_t size, int direction,
+				   dma_addr_t dma_addr);
+
+extern void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
+				     size_t size, int direction);
+
+extern void debug_dma_sync_single_for_cpu(struct device *dev,
+					  dma_addr_t dma_handle, size_t size,
+					  int direction);
+
+extern void debug_dma_sync_single_for_device(struct device *dev,
+					     dma_addr_t dma_handle,
+					     size_t size, int direction);
+
+extern void debug_dma_sync_sg_for_cpu(struct device *dev,
+				      struct scatterlist *sg,
+				      int nelems, int direction);
+
+extern void debug_dma_sync_sg_for_device(struct device *dev,
+					 struct scatterlist *sg,
+					 int nelems, int direction);
+#else /* CONFIG_DMA_API_DEBUG */
+static inline void debug_dma_map_page(struct device *dev, struct page *page,
+				      size_t offset, size_t size,
+				      int direction, dma_addr_t dma_addr)
+{
+}
+
+static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
+					size_t size, int direction)
+{
+}
+
+static inline void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
+				    int nents, int mapped_ents, int direction)
+{
+}
+
+static inline void debug_dma_unmap_sg(struct device *dev,
+				      struct scatterlist *sglist,
+				      int nelems, int dir)
+{
+}
+
+static inline void debug_dma_alloc_coherent(struct device *dev, size_t size,
+					    dma_addr_t dma_addr, void *virt)
+{
+}
+
+static inline void debug_dma_free_coherent(struct device *dev, size_t size,
+					   void *virt, dma_addr_t addr)
+{
+}
+
+static inline void debug_dma_map_resource(struct device *dev, phys_addr_t addr,
+					  size_t size, int direction,
+					  dma_addr_t dma_addr)
+{
+}
+
+static inline void debug_dma_unmap_resource(struct device *dev,
+					    dma_addr_t dma_addr, size_t size,
+					    int direction)
+{
+}
+
+static inline void debug_dma_sync_single_for_cpu(struct device *dev,
+						 dma_addr_t dma_handle,
+						 size_t size, int direction)
+{
+}
+
+static inline void debug_dma_sync_single_for_device(struct device *dev,
+						    dma_addr_t dma_handle,
+						    size_t size, int direction)
+{
+}
+
+static inline void debug_dma_sync_sg_for_cpu(struct device *dev,
+					     struct scatterlist *sg,
+					     int nelems, int direction)
+{
+}
+
+static inline void debug_dma_sync_sg_for_device(struct device *dev,
+						struct scatterlist *sg,
+						int nelems, int direction)
+{
+}
+#endif /* CONFIG_DMA_API_DEBUG */
+#endif /* _KERNEL_DMA_DEBUG_H */
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 0a093a6..06c1115 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -1,48 +1,41 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright (C) 2018 Christoph Hellwig.
+ * Copyright (C) 2018-2020 Christoph Hellwig.
  *
  * DMA operations that map physical memory directly without using an IOMMU.
  */
 #include <linux/memblock.h> /* for max_pfn */
 #include <linux/export.h>
 #include <linux/mm.h>
-#include <linux/dma-direct.h>
+#include <linux/dma-map-ops.h>
 #include <linux/scatterlist.h>
-#include <linux/dma-contiguous.h>
-#include <linux/dma-noncoherent.h>
 #include <linux/pfn.h>
+#include <linux/vmalloc.h>
 #include <linux/set_memory.h>
-#include <linux/swiotlb.h>
+#include <linux/slab.h>
+#include "direct.h"
 
 /*
- * Most architectures use ZONE_DMA for the first 16 Megabytes, but
- * some use it for entirely different regions:
+ * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use
+ * it for entirely different regions. In that case the arch code needs to
+ * override the variable below for dma-direct to work properly.
  */
-#ifndef ARCH_ZONE_DMA_BITS
-#define ARCH_ZONE_DMA_BITS 24
-#endif
-
-static void report_addr(struct device *dev, dma_addr_t dma_addr, size_t size)
-{
-	if (!dev->dma_mask) {
-		dev_err_once(dev, "DMA map on device without dma_mask\n");
-	} else if (*dev->dma_mask >= DMA_BIT_MASK(32) || dev->bus_dma_mask) {
-		dev_err_once(dev,
-			"overflow %pad+%zu of DMA mask %llx bus mask %llx\n",
-			&dma_addr, size, *dev->dma_mask, dev->bus_dma_mask);
-	}
-	WARN_ON_ONCE(1);
-}
+unsigned int zone_dma_bits __ro_after_init = 24;
 
 static inline dma_addr_t phys_to_dma_direct(struct device *dev,
 		phys_addr_t phys)
 {
 	if (force_dma_unencrypted(dev))
-		return __phys_to_dma(dev, phys);
+		return phys_to_dma_unencrypted(dev, phys);
 	return phys_to_dma(dev, phys);
 }
 
+static inline struct page *dma_direct_to_page(struct device *dev,
+		dma_addr_t dma_addr)
+{
+	return pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_addr)));
+}
+
 u64 dma_direct_get_required_mask(struct device *dev)
 {
 	phys_addr_t phys = (phys_addr_t)(max_pfn - 1) << PAGE_SHIFT;
@@ -51,16 +44,10 @@
 	return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
 }
 
-static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
-		u64 *phys_mask)
+static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
+				  u64 *phys_limit)
 {
-	if (dev->bus_dma_mask && dev->bus_dma_mask < dma_mask)
-		dma_mask = dev->bus_dma_mask;
-
-	if (force_dma_unencrypted(dev))
-		*phys_mask = __dma_to_phys(dev, dma_mask);
-	else
-		*phys_mask = dma_to_phys(dev, dma_mask);
+	u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit);
 
 	/*
 	 * Optimistically try the zone that the physical address mask falls
@@ -70,48 +57,49 @@
 	 * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
 	 * zones.
 	 */
-	if (*phys_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
+	*phys_limit = dma_to_phys(dev, dma_limit);
+	if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits))
 		return GFP_DMA;
-	if (*phys_mask <= DMA_BIT_MASK(32))
+	if (*phys_limit <= DMA_BIT_MASK(32))
 		return GFP_DMA32;
 	return 0;
 }
 
 static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
 {
-	return phys_to_dma_direct(dev, phys) + size - 1 <=
-			min_not_zero(dev->coherent_dma_mask, dev->bus_dma_mask);
+	dma_addr_t dma_addr = phys_to_dma_direct(dev, phys);
+
+	if (dma_addr == DMA_MAPPING_ERROR)
+		return false;
+	return dma_addr + size - 1 <=
+		min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
 }
 
-struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
+		gfp_t gfp)
 {
-	size_t alloc_size = PAGE_ALIGN(size);
 	int node = dev_to_node(dev);
 	struct page *page = NULL;
-	u64 phys_mask;
+	u64 phys_limit;
 
-	if (attrs & DMA_ATTR_NO_WARN)
-		gfp |= __GFP_NOWARN;
+	WARN_ON_ONCE(!PAGE_ALIGNED(size));
 
-	/* we always manually zero the memory once we are done: */
-	gfp &= ~__GFP_ZERO;
-	gfp |= __dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
-			&phys_mask);
-	page = dma_alloc_contiguous(dev, alloc_size, gfp);
+	gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
+					   &phys_limit);
+	page = dma_alloc_contiguous(dev, size, gfp);
 	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
-		dma_free_contiguous(dev, page, alloc_size);
+		dma_free_contiguous(dev, page, size);
 		page = NULL;
 	}
 again:
 	if (!page)
-		page = alloc_pages_node(node, gfp, get_order(alloc_size));
+		page = alloc_pages_node(node, gfp, get_order(size));
 	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
 		dma_free_contiguous(dev, page, size);
 		page = NULL;
 
 		if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
-		    phys_mask < DMA_BIT_MASK(64) &&
+		    phys_limit < DMA_BIT_MASK(64) &&
 		    !(gfp & (GFP_DMA32 | GFP_DMA))) {
 			gfp |= GFP_DMA32;
 			goto again;
@@ -126,26 +114,88 @@
 	return page;
 }
 
-void *dma_direct_alloc_pages(struct device *dev, size_t size,
+static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, gfp_t gfp)
+{
+	struct page *page;
+	u64 phys_mask;
+	void *ret;
+
+	gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
+					   &phys_mask);
+	page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok);
+	if (!page)
+		return NULL;
+	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
+	return ret;
+}
+
+void *dma_direct_alloc(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
 	struct page *page;
 	void *ret;
+	int err;
 
-	page = __dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs);
-	if (!page)
-		return NULL;
+	size = PAGE_ALIGN(size);
+	if (attrs & DMA_ATTR_NO_WARN)
+		gfp |= __GFP_NOWARN;
 
 	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
 	    !force_dma_unencrypted(dev)) {
+		page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);
+		if (!page)
+			return NULL;
 		/* remove any dirty cache lines on the kernel alias */
 		if (!PageHighMem(page))
 			arch_dma_prep_coherent(page, size);
-		*dma_handle = phys_to_dma(dev, page_to_phys(page));
+		*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
 		/* return the page pointer as the opaque cookie */
 		return page;
 	}
 
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
+	    !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
+	    !dev_is_dma_coherent(dev))
+		return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
+
+	/*
+	 * Remapping or decrypting memory may block. If either is required and
+	 * we can't block, allocate the memory from the atomic pools.
+	 */
+	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
+	    !gfpflags_allow_blocking(gfp) &&
+	    (force_dma_unencrypted(dev) ||
+	     (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !dev_is_dma_coherent(dev))))
+		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
+
+	/* we always manually zero the memory once we are done */
+	page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);
+	if (!page)
+		return NULL;
+
+	if ((IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
+	     !dev_is_dma_coherent(dev)) ||
+	    (IS_ENABLED(CONFIG_DMA_REMAP) && PageHighMem(page))) {
+		/* remove any dirty cache lines on the kernel alias */
+		arch_dma_prep_coherent(page, size);
+
+		/* create a coherent mapping */
+		ret = dma_common_contiguous_remap(page, size,
+				dma_pgprot(dev, PAGE_KERNEL, attrs),
+				__builtin_return_address(0));
+		if (!ret)
+			goto out_free_pages;
+		if (force_dma_unencrypted(dev)) {
+			err = set_memory_decrypted((unsigned long)ret,
+						   1 << get_order(size));
+			if (err)
+				goto out_free_pages;
+		}
+		memset(ret, 0, size);
+		goto done;
+	}
+
 	if (PageHighMem(page)) {
 		/*
 		 * Depending on the cma= arguments and per-arch setup
@@ -154,88 +204,136 @@
 		 * so log an error and fail.
 		 */
 		dev_info(dev, "Rejecting highmem page from CMA.\n");
-		__dma_direct_free_pages(dev, size, page);
-		return NULL;
+		goto out_free_pages;
 	}
 
 	ret = page_address(page);
 	if (force_dma_unencrypted(dev)) {
-		set_memory_decrypted((unsigned long)ret, 1 << get_order(size));
-		*dma_handle = __phys_to_dma(dev, page_to_phys(page));
-	} else {
-		*dma_handle = phys_to_dma(dev, page_to_phys(page));
+		err = set_memory_decrypted((unsigned long)ret,
+					   1 << get_order(size));
+		if (err)
+			goto out_free_pages;
 	}
+
 	memset(ret, 0, size);
 
-	if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
-	    dma_alloc_need_uncached(dev, attrs)) {
+	if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
+	    !dev_is_dma_coherent(dev)) {
 		arch_dma_prep_coherent(page, size);
-		ret = uncached_kernel_address(ret);
+		ret = arch_dma_set_uncached(ret, size);
+		if (IS_ERR(ret))
+			goto out_encrypt_pages;
 	}
-
+done:
+	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
 	return ret;
-}
 
-void __dma_direct_free_pages(struct device *dev, size_t size, struct page *page)
-{
+out_encrypt_pages:
+	if (force_dma_unencrypted(dev)) {
+		err = set_memory_encrypted((unsigned long)page_address(page),
+					   1 << get_order(size));
+		/* If memory cannot be re-encrypted, it must be leaked */
+		if (err)
+			return NULL;
+	}
+out_free_pages:
 	dma_free_contiguous(dev, page, size);
+	return NULL;
 }
 
-void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
-		dma_addr_t dma_addr, unsigned long attrs)
+void dma_direct_free(struct device *dev, size_t size,
+		void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs)
 {
 	unsigned int page_order = get_order(size);
 
 	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
 	    !force_dma_unencrypted(dev)) {
 		/* cpu_addr is a struct page cookie, not a kernel address */
-		__dma_direct_free_pages(dev, size, cpu_addr);
+		dma_free_contiguous(dev, cpu_addr, size);
 		return;
 	}
 
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
+	    !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
+	    !dev_is_dma_coherent(dev)) {
+		arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);
+		return;
+	}
+
+	/* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */
+	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
+	    dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size)))
+		return;
+
 	if (force_dma_unencrypted(dev))
 		set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order);
 
-	if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
-	    dma_alloc_need_uncached(dev, attrs))
-		cpu_addr = cached_kernel_address(cpu_addr);
-	__dma_direct_free_pages(dev, size, virt_to_page(cpu_addr));
+	if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr))
+		vunmap(cpu_addr);
+	else if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_CLEAR_UNCACHED))
+		arch_dma_clear_uncached(cpu_addr, size);
+
+	dma_free_contiguous(dev, dma_direct_to_page(dev, dma_addr), size);
 }
 
-void *dma_direct_alloc(struct device *dev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
 {
-	if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
-	    dma_alloc_need_uncached(dev, attrs))
-		return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
-	return dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs);
+	struct page *page;
+	void *ret;
+
+	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
+	    force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp))
+		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
+
+	page = __dma_direct_alloc_pages(dev, size, gfp);
+	if (!page)
+		return NULL;
+	if (PageHighMem(page)) {
+		/*
+		 * Depending on the cma= arguments and per-arch setup
+		 * dma_alloc_contiguous could return highmem pages.
+		 * Without remapping there is no way to return them here,
+		 * so log an error and fail.
+		 */
+		dev_info(dev, "Rejecting highmem page from CMA.\n");
+		goto out_free_pages;
+	}
+
+	ret = page_address(page);
+	if (force_dma_unencrypted(dev)) {
+		if (set_memory_decrypted((unsigned long)ret,
+				1 << get_order(size)))
+			goto out_free_pages;
+	}
+	memset(ret, 0, size);
+	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
+	return page;
+out_free_pages:
+	dma_free_contiguous(dev, page, size);
+	return NULL;
 }
 
-void dma_direct_free(struct device *dev, size_t size,
-		void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs)
+void dma_direct_free_pages(struct device *dev, size_t size,
+		struct page *page, dma_addr_t dma_addr,
+		enum dma_data_direction dir)
 {
-	if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
-	    dma_alloc_need_uncached(dev, attrs))
-		arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);
-	else
-		dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs);
+	unsigned int page_order = get_order(size);
+	void *vaddr = page_address(page);
+
+	/* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */
+	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
+	    dma_free_from_pool(dev, vaddr, size))
+		return;
+
+	if (force_dma_unencrypted(dev))
+		set_memory_encrypted((unsigned long)vaddr, 1 << page_order);
+
+	dma_free_contiguous(dev, page, size);
 }
 
 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
     defined(CONFIG_SWIOTLB)
-void dma_direct_sync_single_for_device(struct device *dev,
-		dma_addr_t addr, size_t size, enum dma_data_direction dir)
-{
-	phys_addr_t paddr = dma_to_phys(dev, addr);
-
-	if (unlikely(is_swiotlb_buffer(paddr)))
-		swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_DEVICE);
-
-	if (!dev_is_dma_coherent(dev))
-		arch_sync_dma_for_device(dev, paddr, size, dir);
-}
-EXPORT_SYMBOL(dma_direct_sync_single_for_device);
-
 void dma_direct_sync_sg_for_device(struct device *dev,
 		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
 {
@@ -250,31 +348,15 @@
 					dir, SYNC_FOR_DEVICE);
 
 		if (!dev_is_dma_coherent(dev))
-			arch_sync_dma_for_device(dev, paddr, sg->length,
+			arch_sync_dma_for_device(paddr, sg->length,
 					dir);
 	}
 }
-EXPORT_SYMBOL(dma_direct_sync_sg_for_device);
 #endif
 
 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
     defined(CONFIG_SWIOTLB)
-void dma_direct_sync_single_for_cpu(struct device *dev,
-		dma_addr_t addr, size_t size, enum dma_data_direction dir)
-{
-	phys_addr_t paddr = dma_to_phys(dev, addr);
-
-	if (!dev_is_dma_coherent(dev)) {
-		arch_sync_dma_for_cpu(dev, paddr, size, dir);
-		arch_sync_dma_for_cpu_all(dev);
-	}
-
-	if (unlikely(is_swiotlb_buffer(paddr)))
-		swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);
-}
-EXPORT_SYMBOL(dma_direct_sync_single_for_cpu);
-
 void dma_direct_sync_sg_for_cpu(struct device *dev,
 		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
 {
@@ -285,30 +367,19 @@
 		phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg));
 
 		if (!dev_is_dma_coherent(dev))
-			arch_sync_dma_for_cpu(dev, paddr, sg->length, dir);
+			arch_sync_dma_for_cpu(paddr, sg->length, dir);
 
 		if (unlikely(is_swiotlb_buffer(paddr)))
 			swiotlb_tbl_sync_single(dev, paddr, sg->length, dir,
 					SYNC_FOR_CPU);
+
+		if (dir == DMA_FROM_DEVICE)
+			arch_dma_mark_clean(paddr, sg->length);
 	}
 
 	if (!dev_is_dma_coherent(dev))
-		arch_sync_dma_for_cpu_all(dev);
+		arch_sync_dma_for_cpu_all();
 }
-EXPORT_SYMBOL(dma_direct_sync_sg_for_cpu);
-
-void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
-		size_t size, enum dma_data_direction dir, unsigned long attrs)
-{
-	phys_addr_t phys = dma_to_phys(dev, addr);
-
-	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
-
-	if (unlikely(is_swiotlb_buffer(phys)))
-		swiotlb_tbl_unmap_single(dev, phys, size, size, dir, attrs);
-}
-EXPORT_SYMBOL(dma_direct_unmap_page);
 
 void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
 		int nents, enum dma_data_direction dir, unsigned long attrs)
@@ -320,35 +391,8 @@
 		dma_direct_unmap_page(dev, sg->dma_address, sg_dma_len(sg), dir,
 			     attrs);
 }
-EXPORT_SYMBOL(dma_direct_unmap_sg);
 #endif
 
-static inline bool dma_direct_possible(struct device *dev, dma_addr_t dma_addr,
-		size_t size)
-{
-	return swiotlb_force != SWIOTLB_FORCE &&
-		dma_capable(dev, dma_addr, size);
-}
-
-dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
-		unsigned long offset, size_t size, enum dma_data_direction dir,
-		unsigned long attrs)
-{
-	phys_addr_t phys = page_to_phys(page) + offset;
-	dma_addr_t dma_addr = phys_to_dma(dev, phys);
-
-	if (unlikely(!dma_direct_possible(dev, dma_addr, size)) &&
-	    !swiotlb_map(dev, &phys, &dma_addr, size, dir, attrs)) {
-		report_addr(dev, dma_addr, size);
-		return DMA_MAPPING_ERROR;
-	}
-
-	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-		arch_sync_dma_for_device(dev, phys, size, dir);
-	return dma_addr;
-}
-EXPORT_SYMBOL(dma_direct_map_page);
-
 int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 		enum dma_data_direction dir, unsigned long attrs)
 {
@@ -369,45 +413,83 @@
 	dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
 	return 0;
 }
-EXPORT_SYMBOL(dma_direct_map_sg);
 
 dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	dma_addr_t dma_addr = paddr;
 
-	if (unlikely(!dma_capable(dev, dma_addr, size))) {
-		report_addr(dev, dma_addr, size);
+	if (unlikely(!dma_capable(dev, dma_addr, size, false))) {
+		dev_err_once(dev,
+			     "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
+			     &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
+		WARN_ON_ONCE(1);
 		return DMA_MAPPING_ERROR;
 	}
 
 	return dma_addr;
 }
-EXPORT_SYMBOL(dma_direct_map_resource);
 
-/*
- * Because 32-bit DMA masks are so common we expect every architecture to be
- * able to satisfy them - either by not supporting more physical memory, or by
- * providing a ZONE_DMA32.  If neither is the case, the architecture needs to
- * use an IOMMU instead of the direct mapping.
- */
+int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs)
+{
+	struct page *page = dma_direct_to_page(dev, dma_addr);
+	int ret;
+
+	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (!ret)
+		sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+	return ret;
+}
+
+bool dma_direct_can_mmap(struct device *dev)
+{
+	return dev_is_dma_coherent(dev) ||
+		IS_ENABLED(CONFIG_DMA_NONCOHERENT_MMAP);
+}
+
+int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs)
+{
+	unsigned long user_count = vma_pages(vma);
+	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned long pfn = PHYS_PFN(dma_to_phys(dev, dma_addr));
+	int ret = -ENXIO;
+
+	vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
+
+	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
+		return ret;
+
+	if (vma->vm_pgoff >= count || user_count > count - vma->vm_pgoff)
+		return -ENXIO;
+	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+			user_count << PAGE_SHIFT, vma->vm_page_prot);
+}
+
 int dma_direct_supported(struct device *dev, u64 mask)
 {
-	u64 min_mask;
-
-	if (IS_ENABLED(CONFIG_ZONE_DMA))
-		min_mask = DMA_BIT_MASK(ARCH_ZONE_DMA_BITS);
-	else
-		min_mask = DMA_BIT_MASK(32);
-
-	min_mask = min_t(u64, min_mask, (max_pfn - 1) << PAGE_SHIFT);
+	u64 min_mask = (max_pfn - 1) << PAGE_SHIFT;
 
 	/*
-	 * This check needs to be against the actual bit mask value, so
-	 * use __phys_to_dma() here so that the SME encryption mask isn't
+	 * Because 32-bit DMA masks are so common we expect every architecture
+	 * to be able to satisfy them - either by not supporting more physical
+	 * memory, or by providing a ZONE_DMA32.  If neither is the case, the
+	 * architecture needs to use an IOMMU instead of the direct mapping.
+	 */
+	if (mask >= DMA_BIT_MASK(32))
+		return 1;
+
+	/*
+	 * This check needs to be against the actual bit mask value, so use
+	 * phys_to_dma_unencrypted() here so that the SME encryption mask isn't
 	 * part of the check.
 	 */
-	return mask >= __phys_to_dma(dev, min_mask);
+	if (IS_ENABLED(CONFIG_ZONE_DMA))
+		min_mask = min_t(u64, min_mask, DMA_BIT_MASK(zone_dma_bits));
+	return mask >= phys_to_dma_unencrypted(dev, min_mask);
 }
 
 size_t dma_direct_max_mapping_size(struct device *dev)
@@ -418,3 +500,51 @@
 		return swiotlb_max_mapping_size(dev);
 	return SIZE_MAX;
 }
+
+bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr)
+{
+	return !dev_is_dma_coherent(dev) ||
+		is_swiotlb_buffer(dma_to_phys(dev, dma_addr));
+}
+
+/**
+ * dma_direct_set_offset - Assign scalar offset for a single DMA range.
+ * @dev:	device pointer; needed to "own" the alloced memory.
+ * @cpu_start:  beginning of memory region covered by this offset.
+ * @dma_start:  beginning of DMA/PCI region covered by this offset.
+ * @size:	size of the region.
+ *
+ * This is for the simple case of a uniform offset which cannot
+ * be discovered by "dma-ranges".
+ *
+ * It returns -ENOMEM if out of memory, -EINVAL if a map
+ * already exists, 0 otherwise.
+ *
+ * Note: any call to this from a driver is a bug.  The mapping needs
+ * to be described by the device tree or other firmware interfaces.
+ */
+int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
+			 dma_addr_t dma_start, u64 size)
+{
+	struct bus_dma_region *map;
+	u64 offset = (u64)cpu_start - (u64)dma_start;
+
+	if (dev->dma_range_map) {
+		dev_err(dev, "attempt to add DMA range to existing map\n");
+		return -EINVAL;
+	}
+
+	if (!offset)
+		return 0;
+
+	map = kcalloc(2, sizeof(*map), GFP_KERNEL);
+	if (!map)
+		return -ENOMEM;
+	map[0].cpu_start = cpu_start;
+	map[0].dma_start = dma_start;
+	map[0].offset = offset;
+	map[0].size = size;
+	dev->dma_range_map = map;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dma_direct_set_offset);
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
new file mode 100644
index 0000000..b986155
--- /dev/null
+++ b/kernel/dma/direct.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 Christoph Hellwig.
+ *
+ * DMA operations that map physical memory directly without using an IOMMU.
+ */
+#ifndef _KERNEL_DMA_DIRECT_H
+#define _KERNEL_DMA_DIRECT_H
+
+#include <linux/dma-direct.h>
+
+int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs);
+bool dma_direct_can_mmap(struct device *dev);
+int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs);
+bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
+int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
+		enum dma_data_direction dir, unsigned long attrs);
+size_t dma_direct_max_mapping_size(struct device *dev);
+
+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
+    defined(CONFIG_SWIOTLB)
+void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir);
+#else
+static inline void dma_direct_sync_sg_for_device(struct device *dev,
+		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
+{
+}
+#endif
+
+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
+    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
+    defined(CONFIG_SWIOTLB)
+void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir, unsigned long attrs);
+void dma_direct_sync_sg_for_cpu(struct device *dev,
+		struct scatterlist *sgl, int nents, enum dma_data_direction dir);
+#else
+static inline void dma_direct_unmap_sg(struct device *dev,
+		struct scatterlist *sgl, int nents, enum dma_data_direction dir,
+		unsigned long attrs)
+{
+}
+static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
+		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
+{
+}
+#endif
+
+static inline void dma_direct_sync_single_for_device(struct device *dev,
+		dma_addr_t addr, size_t size, enum dma_data_direction dir)
+{
+	phys_addr_t paddr = dma_to_phys(dev, addr);
+
+	if (unlikely(is_swiotlb_buffer(paddr)))
+		swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_DEVICE);
+
+	if (!dev_is_dma_coherent(dev))
+		arch_sync_dma_for_device(paddr, size, dir);
+}
+
+static inline void dma_direct_sync_single_for_cpu(struct device *dev,
+		dma_addr_t addr, size_t size, enum dma_data_direction dir)
+{
+	phys_addr_t paddr = dma_to_phys(dev, addr);
+
+	if (!dev_is_dma_coherent(dev)) {
+		arch_sync_dma_for_cpu(paddr, size, dir);
+		arch_sync_dma_for_cpu_all();
+	}
+
+	if (unlikely(is_swiotlb_buffer(paddr)))
+		swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);
+
+	if (dir == DMA_FROM_DEVICE)
+		arch_dma_mark_clean(paddr, size);
+}
+
+static inline dma_addr_t dma_direct_map_page(struct device *dev,
+		struct page *page, unsigned long offset, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	phys_addr_t phys = page_to_phys(page) + offset;
+	dma_addr_t dma_addr = phys_to_dma(dev, phys);
+
+	if (unlikely(swiotlb_force == SWIOTLB_FORCE))
+		return swiotlb_map(dev, phys, size, dir, attrs);
+
+	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
+		if (swiotlb_force != SWIOTLB_NO_FORCE)
+			return swiotlb_map(dev, phys, size, dir, attrs);
+
+		dev_WARN_ONCE(dev, 1,
+			     "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
+			     &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
+		return DMA_MAPPING_ERROR;
+	}
+
+	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		arch_sync_dma_for_device(phys, size, dir);
+	return dma_addr;
+}
+
+static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+	phys_addr_t phys = dma_to_phys(dev, addr);
+
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
+
+	if (unlikely(is_swiotlb_buffer(phys)))
+		swiotlb_tbl_unmap_single(dev, phys, size, size, dir, attrs);
+}
+#endif /* _KERNEL_DMA_DIRECT_H */
diff --git a/kernel/dma/dummy.c b/kernel/dma/dummy.c
index 0560764..eacd4c5 100644
--- a/kernel/dma/dummy.c
+++ b/kernel/dma/dummy.c
@@ -2,7 +2,7 @@
 /*
  * Dummy DMA ops that always fail.
  */
-#include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
 
 static int dma_dummy_mmap(struct device *dev, struct vm_area_struct *vma,
 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
@@ -36,4 +36,3 @@
 	.map_sg                 = dma_dummy_map_sg,
 	.dma_supported          = dma_dummy_supported,
 };
-EXPORT_SYMBOL(dma_dummy_ops);
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 8682a53..51bb8fa 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -7,13 +7,14 @@
  */
 #include <linux/memblock.h> /* for max_pfn */
 #include <linux/acpi.h>
-#include <linux/dma-direct.h>
-#include <linux/dma-noncoherent.h>
+#include <linux/dma-map-ops.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
 #include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
+#include "debug.h"
+#include "direct.h"
 
 /*
  * Managed DMA API
@@ -105,37 +106,207 @@
 }
 EXPORT_SYMBOL(dmam_alloc_attrs);
 
-/*
- * Create scatter-list for the already allocated DMA buffer.
- */
-int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
-		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		 unsigned long attrs)
+static bool dma_go_direct(struct device *dev, dma_addr_t mask,
+		const struct dma_map_ops *ops)
 {
-	struct page *page;
-	int ret;
-
-	if (!dev_is_dma_coherent(dev)) {
-		unsigned long pfn;
-
-		if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
-			return -ENXIO;
-
-		/* If the PFN is not valid, we do not have a struct page */
-		pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
-		if (!pfn_valid(pfn))
-			return -ENXIO;
-		page = pfn_to_page(pfn);
-	} else {
-		page = virt_to_page(cpu_addr);
-	}
-
-	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
-	if (!ret)
-		sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
-	return ret;
+	if (likely(!ops))
+		return true;
+#ifdef CONFIG_DMA_OPS_BYPASS
+	if (dev->dma_ops_bypass)
+		return min_not_zero(mask, dev->bus_dma_limit) >=
+			    dma_direct_get_required_mask(dev);
+#endif
+	return false;
 }
 
+
+/*
+ * Check if the devices uses a direct mapping for streaming DMA operations.
+ * This allows IOMMU drivers to set a bypass mode if the DMA mask is large
+ * enough.
+ */
+static inline bool dma_alloc_direct(struct device *dev,
+		const struct dma_map_ops *ops)
+{
+	return dma_go_direct(dev, dev->coherent_dma_mask, ops);
+}
+
+static inline bool dma_map_direct(struct device *dev,
+		const struct dma_map_ops *ops)
+{
+	return dma_go_direct(dev, *dev->dma_mask, ops);
+}
+
+dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
+		size_t offset, size_t size, enum dma_data_direction dir,
+		unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	dma_addr_t addr;
+
+	BUG_ON(!valid_dma_direction(dir));
+
+	if (WARN_ON_ONCE(!dev->dma_mask))
+		return DMA_MAPPING_ERROR;
+
+	if (dma_map_direct(dev, ops))
+		addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
+	else
+		addr = ops->map_page(dev, page, offset, size, dir, attrs);
+	debug_dma_map_page(dev, page, offset, size, dir, addr);
+
+	return addr;
+}
+EXPORT_SYMBOL(dma_map_page_attrs);
+
+void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (dma_map_direct(dev, ops))
+		dma_direct_unmap_page(dev, addr, size, dir, attrs);
+	else if (ops->unmap_page)
+		ops->unmap_page(dev, addr, size, dir, attrs);
+	debug_dma_unmap_page(dev, addr, size, dir);
+}
+EXPORT_SYMBOL(dma_unmap_page_attrs);
+
+/*
+ * dma_maps_sg_attrs returns 0 on error and > 0 on success.
+ * It should never return a value < 0.
+ */
+int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	int ents;
+
+	BUG_ON(!valid_dma_direction(dir));
+
+	if (WARN_ON_ONCE(!dev->dma_mask))
+		return 0;
+
+	if (dma_map_direct(dev, ops))
+		ents = dma_direct_map_sg(dev, sg, nents, dir, attrs);
+	else
+		ents = ops->map_sg(dev, sg, nents, dir, attrs);
+	BUG_ON(ents < 0);
+	debug_dma_map_sg(dev, sg, nents, ents, dir);
+
+	return ents;
+}
+EXPORT_SYMBOL(dma_map_sg_attrs);
+
+void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
+				      int nents, enum dma_data_direction dir,
+				      unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	debug_dma_unmap_sg(dev, sg, nents, dir);
+	if (dma_map_direct(dev, ops))
+		dma_direct_unmap_sg(dev, sg, nents, dir, attrs);
+	else if (ops->unmap_sg)
+		ops->unmap_sg(dev, sg, nents, dir, attrs);
+}
+EXPORT_SYMBOL(dma_unmap_sg_attrs);
+
+dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	dma_addr_t addr = DMA_MAPPING_ERROR;
+
+	BUG_ON(!valid_dma_direction(dir));
+
+	if (WARN_ON_ONCE(!dev->dma_mask))
+		return DMA_MAPPING_ERROR;
+
+	/* Don't allow RAM to be mapped */
+	if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr))))
+		return DMA_MAPPING_ERROR;
+
+	if (dma_map_direct(dev, ops))
+		addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
+	else if (ops->map_resource)
+		addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
+
+	debug_dma_map_resource(dev, phys_addr, size, dir, addr);
+	return addr;
+}
+EXPORT_SYMBOL(dma_map_resource);
+
+void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (!dma_map_direct(dev, ops) && ops->unmap_resource)
+		ops->unmap_resource(dev, addr, size, dir, attrs);
+	debug_dma_unmap_resource(dev, addr, size, dir);
+}
+EXPORT_SYMBOL(dma_unmap_resource);
+
+void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
+		enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (dma_map_direct(dev, ops))
+		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
+	else if (ops->sync_single_for_cpu)
+		ops->sync_single_for_cpu(dev, addr, size, dir);
+	debug_dma_sync_single_for_cpu(dev, addr, size, dir);
+}
+EXPORT_SYMBOL(dma_sync_single_for_cpu);
+
+void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
+		size_t size, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (dma_map_direct(dev, ops))
+		dma_direct_sync_single_for_device(dev, addr, size, dir);
+	else if (ops->sync_single_for_device)
+		ops->sync_single_for_device(dev, addr, size, dir);
+	debug_dma_sync_single_for_device(dev, addr, size, dir);
+}
+EXPORT_SYMBOL(dma_sync_single_for_device);
+
+void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+		    int nelems, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (dma_map_direct(dev, ops))
+		dma_direct_sync_sg_for_cpu(dev, sg, nelems, dir);
+	else if (ops->sync_sg_for_cpu)
+		ops->sync_sg_for_cpu(dev, sg, nelems, dir);
+	debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir);
+}
+EXPORT_SYMBOL(dma_sync_sg_for_cpu);
+
+void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+		       int nelems, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (dma_map_direct(dev, ops))
+		dma_direct_sync_sg_for_device(dev, sg, nelems, dir);
+	else if (ops->sync_sg_for_device)
+		ops->sync_sg_for_device(dev, sg, nelems, dir);
+	debug_dma_sync_sg_for_device(dev, sg, nelems, dir);
+}
+EXPORT_SYMBOL(dma_sync_sg_for_device);
+
 /*
  * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
  * that the intention is to allow exporting memory allocated via the
@@ -153,8 +324,8 @@
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_is_direct(ops))
-		return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr,
+	if (dma_alloc_direct(dev, ops))
+		return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr,
 				size, attrs);
 	if (!ops->get_sgtable)
 		return -ENXIO;
@@ -171,9 +342,7 @@
 {
 	if (force_dma_unencrypted(dev))
 		prot = pgprot_decrypted(prot);
-	if (dev_is_dma_coherent(dev) ||
-	    (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
-             (attrs & DMA_ATTR_NON_CONSISTENT)))
+	if (dev_is_dma_coherent(dev))
 		return prot;
 #ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
 	if (attrs & DMA_ATTR_WRITE_COMBINE)
@@ -183,47 +352,6 @@
 }
 #endif /* CONFIG_MMU */
 
-/*
- * Create userspace mapping for the DMA-coherent memory.
- */
-int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
-		void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		unsigned long attrs)
-{
-#ifdef CONFIG_MMU
-	unsigned long user_count = vma_pages(vma);
-	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	unsigned long off = vma->vm_pgoff;
-	unsigned long pfn;
-	int ret = -ENXIO;
-
-	vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
-
-	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
-		return ret;
-
-	if (off >= count || user_count > count - off)
-		return -ENXIO;
-
-	if (!dev_is_dma_coherent(dev)) {
-		if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
-			return -ENXIO;
-
-		/* If the PFN is not valid, we do not have a struct page */
-		pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
-		if (!pfn_valid(pfn))
-			return -ENXIO;
-	} else {
-		pfn = page_to_pfn(virt_to_page(cpu_addr));
-	}
-
-	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
-			user_count << PAGE_SHIFT, vma->vm_page_prot);
-#else
-	return -ENXIO;
-#endif /* CONFIG_MMU */
-}
-
 /**
  * dma_can_mmap - check if a given device supports dma_mmap_*
  * @dev: device to check
@@ -235,12 +363,8 @@
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_is_direct(ops)) {
-		return IS_ENABLED(CONFIG_MMU) &&
-		       (dev_is_dma_coherent(dev) ||
-			IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN));
-	}
-
+	if (dma_alloc_direct(dev, ops))
+		return dma_direct_can_mmap(dev);
 	return ops->mmap != NULL;
 }
 EXPORT_SYMBOL_GPL(dma_can_mmap);
@@ -264,8 +388,8 @@
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_is_direct(ops))
-		return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size,
+	if (dma_alloc_direct(dev, ops))
+		return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size,
 				attrs);
 	if (!ops->mmap)
 		return -ENXIO;
@@ -277,7 +401,7 @@
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_is_direct(ops))
+	if (dma_alloc_direct(dev, ops))
 		return dma_direct_get_required_mask(dev);
 	if (ops->get_required_mask)
 		return ops->get_required_mask(dev);
@@ -308,7 +432,7 @@
 	/* let the implementation decide on the zone to allocate from: */
 	flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
 
-	if (dma_is_direct(ops))
+	if (dma_alloc_direct(dev, ops))
 		cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
 	else if (ops->alloc)
 		cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
@@ -340,18 +464,102 @@
 		return;
 
 	debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
-	if (dma_is_direct(ops))
+	if (dma_alloc_direct(dev, ops))
 		dma_direct_free(dev, size, cpu_addr, dma_handle, attrs);
 	else if (ops->free)
 		ops->free(dev, size, cpu_addr, dma_handle, attrs);
 }
 EXPORT_SYMBOL(dma_free_attrs);
 
+struct page *dma_alloc_pages(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	struct page *page;
+
+	if (WARN_ON_ONCE(!dev->coherent_dma_mask))
+		return NULL;
+	if (WARN_ON_ONCE(gfp & (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM)))
+		return NULL;
+
+	size = PAGE_ALIGN(size);
+	if (dma_alloc_direct(dev, ops))
+		page = dma_direct_alloc_pages(dev, size, dma_handle, dir, gfp);
+	else if (ops->alloc_pages)
+		page = ops->alloc_pages(dev, size, dma_handle, dir, gfp);
+	else
+		return NULL;
+
+	debug_dma_map_page(dev, page, 0, size, dir, *dma_handle);
+
+	return page;
+}
+EXPORT_SYMBOL_GPL(dma_alloc_pages);
+
+void dma_free_pages(struct device *dev, size_t size, struct page *page,
+		dma_addr_t dma_handle, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	size = PAGE_ALIGN(size);
+	debug_dma_unmap_page(dev, dma_handle, size, dir);
+
+	if (dma_alloc_direct(dev, ops))
+		dma_direct_free_pages(dev, size, page, dma_handle, dir);
+	else if (ops->free_pages)
+		ops->free_pages(dev, size, page, dma_handle, dir);
+}
+EXPORT_SYMBOL_GPL(dma_free_pages);
+
+void *dma_alloc_noncoherent(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	void *vaddr;
+
+	if (!ops || !ops->alloc_noncoherent) {
+		struct page *page;
+
+		page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
+		if (!page)
+			return NULL;
+		return page_address(page);
+	}
+
+	size = PAGE_ALIGN(size);
+	vaddr = ops->alloc_noncoherent(dev, size, dma_handle, dir, gfp);
+	if (vaddr)
+		debug_dma_map_page(dev, virt_to_page(vaddr), 0, size, dir,
+				   *dma_handle);
+	return vaddr;
+}
+EXPORT_SYMBOL_GPL(dma_alloc_noncoherent);
+
+void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
+		dma_addr_t dma_handle, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (!ops || !ops->free_noncoherent) {
+		dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
+		return;
+	}
+
+	size = PAGE_ALIGN(size);
+	debug_dma_unmap_page(dev, dma_handle, size, dir);
+	ops->free_noncoherent(dev, size, vaddr, dma_handle, dir);
+}
+EXPORT_SYMBOL_GPL(dma_free_noncoherent);
+
 int dma_supported(struct device *dev, u64 mask)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (dma_is_direct(ops))
+	/*
+	 * ->dma_supported sets the bypass flag, so we must always call
+	 * into the method here unless the device is truly direct mapped.
+	 */
+	if (!ops)
 		return dma_direct_supported(dev, mask);
 	if (!ops->dma_supported)
 		return 1;
@@ -400,26 +608,12 @@
 EXPORT_SYMBOL(dma_set_coherent_mask);
 #endif
 
-void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
-		enum dma_data_direction dir)
-{
-	const struct dma_map_ops *ops = get_dma_ops(dev);
-
-	BUG_ON(!valid_dma_direction(dir));
-
-	if (dma_is_direct(ops))
-		arch_dma_cache_sync(dev, vaddr, size, dir);
-	else if (ops->cache_sync)
-		ops->cache_sync(dev, vaddr, size, dir);
-}
-EXPORT_SYMBOL(dma_cache_sync);
-
 size_t dma_max_mapping_size(struct device *dev)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 	size_t size = SIZE_MAX;
 
-	if (dma_is_direct(ops))
+	if (dma_map_direct(dev, ops))
 		size = dma_direct_max_mapping_size(dev);
 	else if (ops && ops->max_mapping_size)
 		size = ops->max_mapping_size(dev);
@@ -428,6 +622,16 @@
 }
 EXPORT_SYMBOL_GPL(dma_max_mapping_size);
 
+bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (dma_map_direct(dev, ops))
+		return dma_direct_need_sync(dev, dma_addr);
+	return ops->sync_single_for_cpu || ops->sync_single_for_device;
+}
+EXPORT_SYMBOL_GPL(dma_need_sync);
+
 unsigned long dma_get_merge_boundary(struct device *dev)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c
new file mode 100644
index 0000000..af4a6ef
--- /dev/null
+++ b/kernel/dma/ops_helpers.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helpers for DMA ops implementations.  These generally rely on the fact that
+ * the allocated memory contains normal pages in the direct kernel mapping.
+ */
+#include <linux/dma-map-ops.h>
+
+static struct page *dma_common_vaddr_to_page(void *cpu_addr)
+{
+	if (is_vmalloc_addr(cpu_addr))
+		return vmalloc_to_page(cpu_addr);
+	return virt_to_page(cpu_addr);
+}
+
+/*
+ * Create scatter-list for the already allocated DMA buffer.
+ */
+int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
+		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		 unsigned long attrs)
+{
+	struct page *page = dma_common_vaddr_to_page(cpu_addr);
+	int ret;
+
+	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (!ret)
+		sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+	return ret;
+}
+
+/*
+ * Create userspace mapping for the DMA-coherent memory.
+ */
+int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs)
+{
+#ifdef CONFIG_MMU
+	unsigned long user_count = vma_pages(vma);
+	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned long off = vma->vm_pgoff;
+	struct page *page = dma_common_vaddr_to_page(cpu_addr);
+	int ret = -ENXIO;
+
+	vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
+
+	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
+		return ret;
+
+	if (off >= count || user_count > count - off)
+		return -ENXIO;
+
+	return remap_pfn_range(vma, vma->vm_start,
+			page_to_pfn(page) + vma->vm_pgoff,
+			user_count << PAGE_SHIFT, vma->vm_page_prot);
+#else
+	return -ENXIO;
+#endif /* CONFIG_MMU */
+}
+
+struct page *dma_common_alloc_pages(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	struct page *page;
+
+	page = dma_alloc_contiguous(dev, size, gfp);
+	if (!page)
+		page = alloc_pages_node(dev_to_node(dev), gfp, get_order(size));
+	if (!page)
+		return NULL;
+
+	*dma_handle = ops->map_page(dev, page, 0, size, dir,
+				    DMA_ATTR_SKIP_CPU_SYNC);
+	if (*dma_handle == DMA_MAPPING_ERROR) {
+		dma_free_contiguous(dev, page, size);
+		return NULL;
+	}
+
+	memset(page_address(page), 0, size);
+	return page;
+}
+
+void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
+		dma_addr_t dma_handle, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (ops->unmap_page)
+		ops->unmap_page(dev, dma_handle, size, dir,
+				DMA_ATTR_SKIP_CPU_SYNC);
+	dma_free_contiguous(dev, page, size);
+}
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
new file mode 100644
index 0000000..b9082b5
--- /dev/null
+++ b/kernel/dma/pool.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2020 Google LLC
+ */
+#include <linux/cma.h>
+#include <linux/debugfs.h>
+#include <linux/dma-map-ops.h>
+#include <linux/dma-direct.h>
+#include <linux/init.h>
+#include <linux/genalloc.h>
+#include <linux/set_memory.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+static struct gen_pool *atomic_pool_dma __ro_after_init;
+static unsigned long pool_size_dma;
+static struct gen_pool *atomic_pool_dma32 __ro_after_init;
+static unsigned long pool_size_dma32;
+static struct gen_pool *atomic_pool_kernel __ro_after_init;
+static unsigned long pool_size_kernel;
+
+/* Size can be defined by the coherent_pool command line */
+static size_t atomic_pool_size;
+
+/* Dynamic background expansion when the atomic pool is near capacity */
+static struct work_struct atomic_pool_work;
+
+static int __init early_coherent_pool(char *p)
+{
+	atomic_pool_size = memparse(p, &p);
+	return 0;
+}
+early_param("coherent_pool", early_coherent_pool);
+
+static void __init dma_atomic_pool_debugfs_init(void)
+{
+	struct dentry *root;
+
+	root = debugfs_create_dir("dma_pools", NULL);
+	if (IS_ERR_OR_NULL(root))
+		return;
+
+	debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
+	debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
+	debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
+}
+
+static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
+{
+	if (gfp & __GFP_DMA)
+		pool_size_dma += size;
+	else if (gfp & __GFP_DMA32)
+		pool_size_dma32 += size;
+	else
+		pool_size_kernel += size;
+}
+
+static bool cma_in_zone(gfp_t gfp)
+{
+	unsigned long size;
+	phys_addr_t end;
+	struct cma *cma;
+
+	cma = dev_get_cma_area(NULL);
+	if (!cma)
+		return false;
+
+	size = cma_get_size(cma);
+	if (!size)
+		return false;
+
+	/* CMA can't cross zone boundaries, see cma_activate_area() */
+	end = cma_get_base(cma) + size - 1;
+	if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
+		return end <= DMA_BIT_MASK(zone_dma_bits);
+	if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
+		return end <= DMA_BIT_MASK(32);
+	return true;
+}
+
+static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
+			      gfp_t gfp)
+{
+	unsigned int order;
+	struct page *page = NULL;
+	void *addr;
+	int ret = -ENOMEM;
+
+	/* Cannot allocate larger than MAX_ORDER-1 */
+	order = min(get_order(pool_size), MAX_ORDER-1);
+
+	do {
+		pool_size = 1 << (PAGE_SHIFT + order);
+		if (cma_in_zone(gfp))
+			page = dma_alloc_from_contiguous(NULL, 1 << order,
+							 order, false);
+		if (!page)
+			page = alloc_pages(gfp, order);
+	} while (!page && order-- > 0);
+	if (!page)
+		goto out;
+
+	arch_dma_prep_coherent(page, pool_size);
+
+#ifdef CONFIG_DMA_DIRECT_REMAP
+	addr = dma_common_contiguous_remap(page, pool_size,
+					   pgprot_dmacoherent(PAGE_KERNEL),
+					   __builtin_return_address(0));
+	if (!addr)
+		goto free_page;
+#else
+	addr = page_to_virt(page);
+#endif
+	/*
+	 * Memory in the atomic DMA pools must be unencrypted, the pools do not
+	 * shrink so no re-encryption occurs in dma_direct_free().
+	 */
+	ret = set_memory_decrypted((unsigned long)page_to_virt(page),
+				   1 << order);
+	if (ret)
+		goto remove_mapping;
+	ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
+				pool_size, NUMA_NO_NODE);
+	if (ret)
+		goto encrypt_mapping;
+
+	dma_atomic_pool_size_add(gfp, pool_size);
+	return 0;
+
+encrypt_mapping:
+	ret = set_memory_encrypted((unsigned long)page_to_virt(page),
+				   1 << order);
+	if (WARN_ON_ONCE(ret)) {
+		/* Decrypt succeeded but encrypt failed, purposely leak */
+		goto out;
+	}
+remove_mapping:
+#ifdef CONFIG_DMA_DIRECT_REMAP
+	dma_common_free_remap(addr, pool_size);
+#endif
+free_page: __maybe_unused
+	__free_pages(page, order);
+out:
+	return ret;
+}
+
+static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
+{
+	if (pool && gen_pool_avail(pool) < atomic_pool_size)
+		atomic_pool_expand(pool, gen_pool_size(pool), gfp);
+}
+
+static void atomic_pool_work_fn(struct work_struct *work)
+{
+	if (IS_ENABLED(CONFIG_ZONE_DMA))
+		atomic_pool_resize(atomic_pool_dma,
+				   GFP_KERNEL | GFP_DMA);
+	if (IS_ENABLED(CONFIG_ZONE_DMA32))
+		atomic_pool_resize(atomic_pool_dma32,
+				   GFP_KERNEL | GFP_DMA32);
+	atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
+}
+
+static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
+						      gfp_t gfp)
+{
+	struct gen_pool *pool;
+	int ret;
+
+	pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
+	if (!pool)
+		return NULL;
+
+	gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
+
+	ret = atomic_pool_expand(pool, pool_size, gfp);
+	if (ret) {
+		gen_pool_destroy(pool);
+		pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n",
+		       pool_size >> 10, &gfp);
+		return NULL;
+	}
+
+	pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
+		gen_pool_size(pool) >> 10, &gfp);
+	return pool;
+}
+
+static int __init dma_atomic_pool_init(void)
+{
+	int ret = 0;
+
+	/*
+	 * If coherent_pool was not used on the command line, default the pool
+	 * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1.
+	 */
+	if (!atomic_pool_size) {
+		unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
+		pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
+		atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
+	}
+	INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);
+
+	atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
+						    GFP_KERNEL);
+	if (!atomic_pool_kernel)
+		ret = -ENOMEM;
+	if (has_managed_dma()) {
+		atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
+						GFP_KERNEL | GFP_DMA);
+		if (!atomic_pool_dma)
+			ret = -ENOMEM;
+	}
+	if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
+		atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
+						GFP_KERNEL | GFP_DMA32);
+		if (!atomic_pool_dma32)
+			ret = -ENOMEM;
+	}
+
+	dma_atomic_pool_debugfs_init();
+	return ret;
+}
+postcore_initcall(dma_atomic_pool_init);
+
+static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
+{
+	if (prev == NULL) {
+		if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
+			return atomic_pool_dma32;
+		if (atomic_pool_dma && (gfp & GFP_DMA))
+			return atomic_pool_dma;
+		return atomic_pool_kernel;
+	}
+	if (prev == atomic_pool_kernel)
+		return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
+	if (prev == atomic_pool_dma32)
+		return atomic_pool_dma;
+	return NULL;
+}
+
+static struct page *__dma_alloc_from_pool(struct device *dev, size_t size,
+		struct gen_pool *pool, void **cpu_addr,
+		bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
+{
+	unsigned long addr;
+	phys_addr_t phys;
+
+	addr = gen_pool_alloc(pool, size);
+	if (!addr)
+		return NULL;
+
+	phys = gen_pool_virt_to_phys(pool, addr);
+	if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
+		gen_pool_free(pool, addr, size);
+		return NULL;
+	}
+
+	if (gen_pool_avail(pool) < atomic_pool_size)
+		schedule_work(&atomic_pool_work);
+
+	*cpu_addr = (void *)addr;
+	memset(*cpu_addr, 0, size);
+	return pfn_to_page(__phys_to_pfn(phys));
+}
+
+struct page *dma_alloc_from_pool(struct device *dev, size_t size,
+		void **cpu_addr, gfp_t gfp,
+		bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
+{
+	struct gen_pool *pool = NULL;
+	struct page *page;
+
+	while ((pool = dma_guess_pool(pool, gfp))) {
+		page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
+					     phys_addr_ok);
+		if (page)
+			return page;
+	}
+
+	WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
+	return NULL;
+}
+
+bool dma_free_from_pool(struct device *dev, void *start, size_t size)
+{
+	struct gen_pool *pool = NULL;
+
+	while ((pool = dma_guess_pool(pool, 0))) {
+		if (!gen_pool_has_addr(pool, (unsigned long)start, size))
+			continue;
+		gen_pool_free(pool, (unsigned long)start, size);
+		return true;
+	}
+
+	return false;
+}
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index c00b925..905c3fa 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -1,13 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright (C) 2012 ARM Ltd.
  * Copyright (c) 2014 The Linux Foundation
  */
-#include <linux/dma-direct.h>
-#include <linux/dma-noncoherent.h>
-#include <linux/dma-contiguous.h>
-#include <linux/init.h>
-#include <linux/genalloc.h>
+#include <linux/dma-map-ops.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
@@ -20,23 +15,6 @@
 	return area->pages;
 }
 
-static struct vm_struct *__dma_common_pages_remap(struct page **pages,
-			size_t size, pgprot_t prot, const void *caller)
-{
-	struct vm_struct *area;
-
-	area = get_vm_area_caller(size, VM_DMA_COHERENT, caller);
-	if (!area)
-		return NULL;
-
-	if (map_vm_area(area, prot, pages)) {
-		vunmap(area->addr);
-		return NULL;
-	}
-
-	return area;
-}
-
 /*
  * Remaps an array of PAGE_SIZE pages into another vm_area.
  * Cannot be used in non-sleeping contexts
@@ -44,15 +22,13 @@
 void *dma_common_pages_remap(struct page **pages, size_t size,
 			 pgprot_t prot, const void *caller)
 {
-	struct vm_struct *area;
+	void *vaddr;
 
-	area = __dma_common_pages_remap(pages, size, prot, caller);
-	if (!area)
-		return NULL;
-
-	area->pages = pages;
-
-	return area->addr;
+	vaddr = vmap(pages, PAGE_ALIGN(size) >> PAGE_SHIFT,
+		     VM_DMA_COHERENT, prot);
+	if (vaddr)
+		find_vm_area(vaddr)->pages = pages;
+	return vaddr;
 }
 
 /*
@@ -62,24 +38,20 @@
 void *dma_common_contiguous_remap(struct page *page, size_t size,
 			pgprot_t prot, const void *caller)
 {
-	int i;
+	int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	struct page **pages;
-	struct vm_struct *area;
+	void *vaddr;
+	int i;
 
-	pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
+	pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
 	if (!pages)
 		return NULL;
-
-	for (i = 0; i < (size >> PAGE_SHIFT); i++)
+	for (i = 0; i < count; i++)
 		pages[i] = nth_page(page, i);
-
-	area = __dma_common_pages_remap(pages, size, prot, caller);
-
+	vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);
 	kfree(pages);
 
-	if (!area)
-		return NULL;
-	return area->addr;
+	return vaddr;
 }
 
 /*
@@ -97,172 +69,3 @@
 	unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
 	vunmap(cpu_addr);
 }
-
-#ifdef CONFIG_DMA_DIRECT_REMAP
-static struct gen_pool *atomic_pool __ro_after_init;
-
-#define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K
-static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
-
-static int __init early_coherent_pool(char *p)
-{
-	atomic_pool_size = memparse(p, &p);
-	return 0;
-}
-early_param("coherent_pool", early_coherent_pool);
-
-static gfp_t dma_atomic_pool_gfp(void)
-{
-	if (IS_ENABLED(CONFIG_ZONE_DMA))
-		return GFP_DMA;
-	if (IS_ENABLED(CONFIG_ZONE_DMA32))
-		return GFP_DMA32;
-	return GFP_KERNEL;
-}
-
-static int __init dma_atomic_pool_init(void)
-{
-	unsigned int pool_size_order = get_order(atomic_pool_size);
-	unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
-	struct page *page;
-	void *addr;
-	int ret;
-
-	if (dev_get_cma_area(NULL))
-		page = dma_alloc_from_contiguous(NULL, nr_pages,
-						 pool_size_order, false);
-	else
-		page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order);
-	if (!page)
-		goto out;
-
-	arch_dma_prep_coherent(page, atomic_pool_size);
-
-	atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
-	if (!atomic_pool)
-		goto free_page;
-
-	addr = dma_common_contiguous_remap(page, atomic_pool_size,
-					   pgprot_dmacoherent(PAGE_KERNEL),
-					   __builtin_return_address(0));
-	if (!addr)
-		goto destroy_genpool;
-
-	ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
-				page_to_phys(page), atomic_pool_size, -1);
-	if (ret)
-		goto remove_mapping;
-	gen_pool_set_algo(atomic_pool, gen_pool_first_fit_order_align, NULL);
-
-	pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
-		atomic_pool_size / 1024);
-	return 0;
-
-remove_mapping:
-	dma_common_free_remap(addr, atomic_pool_size);
-destroy_genpool:
-	gen_pool_destroy(atomic_pool);
-	atomic_pool = NULL;
-free_page:
-	if (!dma_release_from_contiguous(NULL, page, nr_pages))
-		__free_pages(page, pool_size_order);
-out:
-	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
-		atomic_pool_size / 1024);
-	return -ENOMEM;
-}
-postcore_initcall(dma_atomic_pool_init);
-
-bool dma_in_atomic_pool(void *start, size_t size)
-{
-	if (unlikely(!atomic_pool))
-		return false;
-
-	return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
-}
-
-void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
-{
-	unsigned long val;
-	void *ptr = NULL;
-
-	if (!atomic_pool) {
-		WARN(1, "coherent pool not initialised!\n");
-		return NULL;
-	}
-
-	val = gen_pool_alloc(atomic_pool, size);
-	if (val) {
-		phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
-
-		*ret_page = pfn_to_page(__phys_to_pfn(phys));
-		ptr = (void *)val;
-		memset(ptr, 0, size);
-	}
-
-	return ptr;
-}
-
-bool dma_free_from_pool(void *start, size_t size)
-{
-	if (!dma_in_atomic_pool(start, size))
-		return false;
-	gen_pool_free(atomic_pool, (unsigned long)start, size);
-	return true;
-}
-
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
-		gfp_t flags, unsigned long attrs)
-{
-	struct page *page = NULL;
-	void *ret;
-
-	size = PAGE_ALIGN(size);
-
-	if (!gfpflags_allow_blocking(flags)) {
-		ret = dma_alloc_from_pool(size, &page, flags);
-		if (!ret)
-			return NULL;
-		goto done;
-	}
-
-	page = __dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs);
-	if (!page)
-		return NULL;
-
-	/* remove any dirty cache lines on the kernel alias */
-	arch_dma_prep_coherent(page, size);
-
-	/* create a coherent mapping */
-	ret = dma_common_contiguous_remap(page, size,
-			dma_pgprot(dev, PAGE_KERNEL, attrs),
-			__builtin_return_address(0));
-	if (!ret) {
-		__dma_direct_free_pages(dev, size, page);
-		return ret;
-	}
-
-	memset(ret, 0, size);
-done:
-	*dma_handle = phys_to_dma(dev, page_to_phys(page));
-	return ret;
-}
-
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, unsigned long attrs)
-{
-	if (!dma_free_from_pool(vaddr, PAGE_ALIGN(size))) {
-		phys_addr_t phys = dma_to_phys(dev, dma_handle);
-		struct page *page = pfn_to_page(__phys_to_pfn(phys));
-
-		vunmap(vaddr);
-		__dma_direct_free_pages(dev, size, page);
-	}
-}
-
-long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
-		dma_addr_t dma_addr)
-{
-	return __phys_to_pfn(dma_to_phys(dev, dma_addr));
-}
-#endif /* CONFIG_DMA_DIRECT_REMAP */
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index f99b79d..0ed0e1f 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -22,6 +22,7 @@
 
 #include <linux/cache.h>
 #include <linux/dma-direct.h>
+#include <linux/dma-map-ops.h>
 #include <linux/mm.h>
 #include <linux/export.h>
 #include <linux/spinlock.h>
@@ -49,9 +50,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/swiotlb.h>
 
-#define OFFSET(val,align) ((unsigned long)	\
-	                   ( (val) & ( (align) - 1)))
-
 #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
 
 /*
@@ -92,7 +90,7 @@
  * Max segment that we can provide which (if pages are contingous) will
  * not be bounced (unless SWIOTLB_FORCE is set).
  */
-unsigned int max_segment;
+static unsigned int max_segment;
 
 /*
  * We need to save away the original address corresponding to a mapped entry
@@ -171,12 +169,20 @@
 		return;
 	}
 
-	pr_info("mapped [mem %#010llx-%#010llx] (%luMB)\n",
-	       (unsigned long long)io_tlb_start,
-	       (unsigned long long)io_tlb_end,
+	pr_info("mapped [mem %pa-%pa] (%luMB)\n", &io_tlb_start, &io_tlb_end,
 	       bytes >> 20);
 }
 
+static inline unsigned long io_tlb_offset(unsigned long val)
+{
+	return val & (IO_TLB_SEGSIZE - 1);
+}
+
+static inline unsigned long nr_slots(u64 val)
+{
+	return DIV_ROUND_UP(val, IO_TLB_SIZE);
+}
+
 /*
  * Early SWIOTLB allocation may be too early to allow an architecture to
  * perform the desired operations.  This function allows the architecture to
@@ -226,7 +232,7 @@
 		      __func__, alloc_size, PAGE_SIZE);
 
 	for (i = 0; i < io_tlb_nslabs; i++) {
-		io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+		io_tlb_list[i] = IO_TLB_SEGSIZE - io_tlb_offset(i);
 		io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
 	}
 	io_tlb_index = 0;
@@ -360,7 +366,7 @@
 		goto cleanup4;
 
 	for (i = 0; i < io_tlb_nslabs; i++) {
-		io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+		io_tlb_list[i] = IO_TLB_SEGSIZE - io_tlb_offset(i);
 		io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
 	}
 	io_tlb_index = 0;
@@ -446,22 +452,120 @@
 	}
 }
 
-phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
-				   dma_addr_t tbl_dma_addr,
-				   phys_addr_t orig_addr,
-				   size_t mapping_size,
-				   size_t alloc_size,
-				   enum dma_data_direction dir,
-				   unsigned long attrs)
+#define slot_addr(start, idx)	((start) + ((idx) << IO_TLB_SHIFT))
+
+/*
+ * Return the offset into a iotlb slot required to keep the device happy.
+ */
+static unsigned int swiotlb_align_offset(struct device *dev, u64 addr)
 {
+	return addr & dma_get_min_align_mask(dev) & (IO_TLB_SIZE - 1);
+}
+
+/*
+ * Carefully handle integer overflow which can occur when boundary_mask == ~0UL.
+ */
+static inline unsigned long get_max_slots(unsigned long boundary_mask)
+{
+	if (boundary_mask == ~0UL)
+		return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
+	return nr_slots(boundary_mask + 1);
+}
+
+static unsigned int wrap_index(unsigned int index)
+{
+	if (index >= io_tlb_nslabs)
+		return 0;
+	return index;
+}
+
+/*
+ * Find a suitable number of IO TLB entries size that will fit this request and
+ * allocate a buffer from that IO TLB pool.
+ */
+static int find_slots(struct device *dev, phys_addr_t orig_addr,
+		size_t alloc_size)
+{
+	unsigned long boundary_mask = dma_get_seg_boundary(dev);
+	dma_addr_t tbl_dma_addr =
+		phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask;
+	unsigned long max_slots = get_max_slots(boundary_mask);
+	unsigned int iotlb_align_mask =
+		dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
+	unsigned int nslots = nr_slots(alloc_size), stride;
+	unsigned int index, wrap, count = 0, i;
 	unsigned long flags;
+
+	BUG_ON(!nslots);
+
+	/*
+	 * For mappings with an alignment requirement don't bother looping to
+	 * unaligned slots once we found an aligned one.  For allocations of
+	 * PAGE_SIZE or larger only look for page aligned allocations.
+	 */
+	stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1;
+	if (alloc_size >= PAGE_SIZE)
+		stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT));
+
+	spin_lock_irqsave(&io_tlb_lock, flags);
+	if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
+		goto not_found;
+
+	index = wrap = wrap_index(ALIGN(io_tlb_index, stride));
+	do {
+		if ((slot_addr(tbl_dma_addr, index) & iotlb_align_mask) !=
+		    (orig_addr & iotlb_align_mask)) {
+			index = wrap_index(index + 1);
+			continue;
+		}
+
+		/*
+		 * If we find a slot that indicates we have 'nslots' number of
+		 * contiguous buffers, we allocate the buffers from that slot
+		 * and mark the entries as '0' indicating unavailable.
+		 */
+		if (!iommu_is_span_boundary(index, nslots,
+					    nr_slots(tbl_dma_addr),
+					    max_slots)) {
+			if (io_tlb_list[index] >= nslots)
+				goto found;
+		}
+		index = wrap_index(index + stride);
+	} while (index != wrap);
+
+not_found:
+	spin_unlock_irqrestore(&io_tlb_lock, flags);
+	return -1;
+
+found:
+	for (i = index; i < index + nslots; i++)
+		io_tlb_list[i] = 0;
+	for (i = index - 1;
+	     io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
+	     io_tlb_list[i]; i--)
+		io_tlb_list[i] = ++count;
+
+	/*
+	 * Update the indices to avoid searching in the next round.
+	 */
+	if (index + nslots < io_tlb_nslabs)
+		io_tlb_index = index + nslots;
+	else
+		io_tlb_index = 0;
+	io_tlb_used += nslots;
+
+	spin_unlock_irqrestore(&io_tlb_lock, flags);
+	return index;
+}
+
+phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
+		size_t mapping_size, size_t alloc_size,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	unsigned int offset = swiotlb_align_offset(dev, orig_addr);
+	unsigned int i;
+	int index;
 	phys_addr_t tlb_addr;
-	unsigned int nslots, stride, index, wrap;
-	int i;
-	unsigned long mask;
-	unsigned long offset_slots;
-	unsigned long max_slots;
-	unsigned long tmp_io_tlb_used;
 
 	if (no_iotlb_memory)
 		panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
@@ -470,111 +574,32 @@
 		pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n");
 
 	if (mapping_size > alloc_size) {
-		dev_warn_once(hwdev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)",
+		dev_warn_once(dev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)",
 			      mapping_size, alloc_size);
 		return (phys_addr_t)DMA_MAPPING_ERROR;
 	}
 
-	mask = dma_get_seg_boundary(hwdev);
-
-	tbl_dma_addr &= mask;
-
-	offset_slots = ALIGN(tbl_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
-
-	/*
-	 * Carefully handle integer overflow which can occur when mask == ~0UL.
-	 */
-	max_slots = mask + 1
-		    ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
-		    : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
-
-	/*
-	 * For mappings greater than or equal to a page, we limit the stride
-	 * (and hence alignment) to a page size.
-	 */
-	nslots = ALIGN(alloc_size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
-	if (alloc_size >= PAGE_SIZE)
-		stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
-	else
-		stride = 1;
-
-	BUG_ON(!nslots);
-
-	/*
-	 * Find suitable number of IO TLB entries size that will fit this
-	 * request and allocate a buffer from that IO TLB pool.
-	 */
-	spin_lock_irqsave(&io_tlb_lock, flags);
-
-	if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
-		goto not_found;
-
-	index = ALIGN(io_tlb_index, stride);
-	if (index >= io_tlb_nslabs)
-		index = 0;
-	wrap = index;
-
-	do {
-		while (iommu_is_span_boundary(index, nslots, offset_slots,
-					      max_slots)) {
-			index += stride;
-			if (index >= io_tlb_nslabs)
-				index = 0;
-			if (index == wrap)
-				goto not_found;
-		}
-
-		/*
-		 * If we find a slot that indicates we have 'nslots' number of
-		 * contiguous buffers, we allocate the buffers from that slot
-		 * and mark the entries as '0' indicating unavailable.
-		 */
-		if (io_tlb_list[index] >= nslots) {
-			int count = 0;
-
-			for (i = index; i < (int) (index + nslots); i++)
-				io_tlb_list[i] = 0;
-			for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
-				io_tlb_list[i] = ++count;
-			tlb_addr = io_tlb_start + (index << IO_TLB_SHIFT);
-
-			/*
-			 * Update the indices to avoid searching in the next
-			 * round.
-			 */
-			io_tlb_index = ((index + nslots) < io_tlb_nslabs
-					? (index + nslots) : 0);
-
-			goto found;
-		}
-		index += stride;
-		if (index >= io_tlb_nslabs)
-			index = 0;
-	} while (index != wrap);
-
-not_found:
-	tmp_io_tlb_used = io_tlb_used;
-
-	spin_unlock_irqrestore(&io_tlb_lock, flags);
-	if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
-		dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
-			 alloc_size, io_tlb_nslabs, tmp_io_tlb_used);
-	return (phys_addr_t)DMA_MAPPING_ERROR;
-found:
-	io_tlb_used += nslots;
-	spin_unlock_irqrestore(&io_tlb_lock, flags);
+	index = find_slots(dev, orig_addr, alloc_size + offset);
+	if (index == -1) {
+		if (!(attrs & DMA_ATTR_NO_WARN))
+			dev_warn_ratelimited(dev,
+	"swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
+				 alloc_size, io_tlb_nslabs, io_tlb_used);
+		return (phys_addr_t)DMA_MAPPING_ERROR;
+	}
 
 	/*
 	 * Save away the mapping from the original address to the DMA address.
 	 * This is needed when we sync the memory.  Then we sync the buffer if
 	 * needed.
 	 */
-	for (i = 0; i < nslots; i++)
-		io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT);
+	for (i = 0; i < nr_slots(alloc_size + offset); i++)
+		io_tlb_orig_addr[index + i] = slot_addr(orig_addr, i);
+
+	tlb_addr = slot_addr(io_tlb_start, index) + offset;
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
 	    (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
 		swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE);
-
 	return tlb_addr;
 }
 
@@ -586,8 +611,9 @@
 			      enum dma_data_direction dir, unsigned long attrs)
 {
 	unsigned long flags;
-	int i, count, nslots = ALIGN(alloc_size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
-	int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
+	unsigned int offset = swiotlb_align_offset(hwdev, tlb_addr);
+	int i, count, nslots = nr_slots(alloc_size + offset);
+	int index = (tlb_addr - offset - io_tlb_start) >> IO_TLB_SHIFT;
 	phys_addr_t orig_addr = io_tlb_orig_addr[index];
 
 	/*
@@ -605,26 +631,29 @@
 	 * with slots below and above the pool being returned.
 	 */
 	spin_lock_irqsave(&io_tlb_lock, flags);
-	{
-		count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
-			 io_tlb_list[index + nslots] : 0);
-		/*
-		 * Step 1: return the slots to the free list, merging the
-		 * slots with superceeding slots
-		 */
-		for (i = index + nslots - 1; i >= index; i--) {
-			io_tlb_list[i] = ++count;
-			io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
-		}
-		/*
-		 * Step 2: merge the returned slots with the preceding slots,
-		 * if available (non zero)
-		 */
-		for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
-			io_tlb_list[i] = ++count;
+	if (index + nslots < ALIGN(index + 1, IO_TLB_SEGSIZE))
+		count = io_tlb_list[index + nslots];
+	else
+		count = 0;
 
-		io_tlb_used -= nslots;
+	/*
+	 * Step 1: return the slots to the free list, merging the slots with
+	 * superceeding slots
+	 */
+	for (i = index + nslots - 1; i >= index; i--) {
+		io_tlb_list[i] = ++count;
+		io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
 	}
+
+	/*
+	 * Step 2: merge the returned slots with the preceding slots, if
+	 * available (non zero)
+	 */
+	for (i = index - 1;
+	     io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && io_tlb_list[i];
+	     i--)
+		io_tlb_list[i] = ++count;
+	io_tlb_used -= nslots;
 	spin_unlock_irqrestore(&io_tlb_lock, flags);
 }
 
@@ -637,7 +666,9 @@
 
 	if (orig_addr == INVALID_PHYS_ADDR)
 		return;
-	orig_addr += (unsigned long)tlb_addr & ((1 << IO_TLB_SHIFT) - 1);
+
+	orig_addr += (tlb_addr & (IO_TLB_SIZE - 1)) -
+		swiotlb_align_offset(hwdev, orig_addr);
 
 	switch (target) {
 	case SYNC_FOR_CPU:
@@ -660,40 +691,42 @@
 }
 
 /*
- * Create a swiotlb mapping for the buffer at @phys, and in case of DMAing
+ * Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing
  * to the device copy the data into it as well.
  */
-bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
-		size_t size, enum dma_data_direction dir, unsigned long attrs)
+dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
 {
-	trace_swiotlb_bounced(dev, *dma_addr, size, swiotlb_force);
+	phys_addr_t swiotlb_addr;
+	dma_addr_t dma_addr;
 
-	if (unlikely(swiotlb_force == SWIOTLB_NO_FORCE)) {
-		dev_warn_ratelimited(dev,
-			"Cannot do DMA to address %pa\n", phys);
-		return false;
-	}
+	trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size,
+			      swiotlb_force);
 
-	/* Oh well, have to allocate and map a bounce buffer. */
-	*phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start),
-			*phys, size, size, dir, attrs);
-	if (*phys == (phys_addr_t)DMA_MAPPING_ERROR)
-		return false;
+	swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, dir,
+			attrs);
+	if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
+		return DMA_MAPPING_ERROR;
 
 	/* Ensure that the address returned is DMA'ble */
-	*dma_addr = __phys_to_dma(dev, *phys);
-	if (unlikely(!dma_capable(dev, *dma_addr, size))) {
-		swiotlb_tbl_unmap_single(dev, *phys, size, size, dir,
+	dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr);
+	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
+		swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, size, dir,
 			attrs | DMA_ATTR_SKIP_CPU_SYNC);
-		return false;
+		dev_WARN_ONCE(dev, 1,
+			"swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
+			&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
+		return DMA_MAPPING_ERROR;
 	}
 
-	return true;
+	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		arch_sync_dma_for_device(swiotlb_addr, size, dir);
+	return dma_addr;
 }
 
 size_t swiotlb_max_mapping_size(struct device *dev)
 {
-	return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE;
+	return ((size_t)IO_TLB_SIZE) * IO_TLB_SEGSIZE;
 }
 
 bool is_swiotlb_active(void)
diff --git a/kernel/dma/virt.c b/kernel/dma/virt.c
index ebe1288..59d3231 100644
--- a/kernel/dma/virt.c
+++ b/kernel/dma/virt.c
@@ -4,7 +4,7 @@
  */
 #include <linux/export.h>
 #include <linux/mm.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
 #include <linux/scatterlist.h>
 
 static void *dma_virt_alloc(struct device *dev, size_t size,
@@ -55,5 +55,7 @@
 	.free			= dma_virt_free,
 	.map_page		= dma_virt_map_page,
 	.map_sg			= dma_virt_map_sg,
+	.alloc_pages		= dma_common_alloc_pages,
+	.free_pages		= dma_common_free_pages,
 };
 EXPORT_SYMBOL(dma_virt_ops);
diff --git a/kernel/entry/Makefile b/kernel/entry/Makefile
new file mode 100644
index 0000000..34c8a3f
--- /dev/null
+++ b/kernel/entry/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Prevent the noinstr section from being pestered by sanitizer and other goodies
+# as long as these things cannot be disabled per function.
+KASAN_SANITIZE := n
+UBSAN_SANITIZE := n
+KCOV_INSTRUMENT := n
+
+CFLAGS_REMOVE_common.o	 = -fstack-protector -fstack-protector-strong
+CFLAGS_common.o		+= -fno-stack-protector
+
+obj-$(CONFIG_GENERIC_ENTRY) 		+= common.o
+obj-$(CONFIG_KVM_XFER_TO_GUEST_WORK)	+= kvm.o
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
new file mode 100644
index 0000000..e289e67
--- /dev/null
+++ b/kernel/entry/common.c
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/context_tracking.h>
+#include <linux/entry-common.h>
+#include <linux/livepatch.h>
+#include <linux/audit.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+/**
+ * enter_from_user_mode - Establish state when coming from user mode
+ *
+ * Syscall/interrupt entry disables interrupts, but user mode is traced as
+ * interrupts enabled. Also with NO_HZ_FULL RCU might be idle.
+ *
+ * 1) Tell lockdep that interrupts are disabled
+ * 2) Invoke context tracking if enabled to reactivate RCU
+ * 3) Trace interrupts off state
+ */
+static __always_inline void enter_from_user_mode(struct pt_regs *regs)
+{
+	arch_check_user_regs(regs);
+	lockdep_hardirqs_off(CALLER_ADDR0);
+
+	CT_WARN_ON(ct_state() != CONTEXT_USER);
+	user_exit_irqoff();
+
+	instrumentation_begin();
+	trace_hardirqs_off_finish();
+	instrumentation_end();
+}
+
+static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
+{
+	if (unlikely(audit_context())) {
+		unsigned long args[6];
+
+		syscall_get_arguments(current, regs, args);
+		audit_syscall_entry(syscall, args[0], args[1], args[2], args[3]);
+	}
+}
+
+static long syscall_trace_enter(struct pt_regs *regs, long syscall,
+				unsigned long ti_work)
+{
+	long ret = 0;
+
+	/* Handle ptrace */
+	if (ti_work & (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU)) {
+		ret = arch_syscall_enter_tracehook(regs);
+		if (ret || (ti_work & _TIF_SYSCALL_EMU))
+			return -1L;
+	}
+
+	/* Do seccomp after ptrace, to catch any tracer changes. */
+	if (ti_work & _TIF_SECCOMP) {
+		ret = __secure_computing(NULL);
+		if (ret == -1L)
+			return ret;
+	}
+
+	/* Either of the above might have changed the syscall number */
+	syscall = syscall_get_nr(current, regs);
+
+	if (unlikely(ti_work & _TIF_SYSCALL_TRACEPOINT))
+		trace_sys_enter(regs, syscall);
+
+	syscall_enter_audit(regs, syscall);
+
+	return ret ? : syscall;
+}
+
+static __always_inline long
+__syscall_enter_from_user_work(struct pt_regs *regs, long syscall)
+{
+	unsigned long ti_work;
+
+	ti_work = READ_ONCE(current_thread_info()->flags);
+	if (ti_work & SYSCALL_ENTER_WORK)
+		syscall = syscall_trace_enter(regs, syscall, ti_work);
+
+	return syscall;
+}
+
+long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall)
+{
+	return __syscall_enter_from_user_work(regs, syscall);
+}
+
+noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall)
+{
+	long ret;
+
+	enter_from_user_mode(regs);
+
+	instrumentation_begin();
+	local_irq_enable();
+	ret = __syscall_enter_from_user_work(regs, syscall);
+	instrumentation_end();
+
+	return ret;
+}
+
+noinstr void syscall_enter_from_user_mode_prepare(struct pt_regs *regs)
+{
+	enter_from_user_mode(regs);
+	instrumentation_begin();
+	local_irq_enable();
+	instrumentation_end();
+}
+
+/**
+ * exit_to_user_mode - Fixup state when exiting to user mode
+ *
+ * Syscall/interupt exit enables interrupts, but the kernel state is
+ * interrupts disabled when this is invoked. Also tell RCU about it.
+ *
+ * 1) Trace interrupts on state
+ * 2) Invoke context tracking if enabled to adjust RCU state
+ * 3) Invoke architecture specific last minute exit code, e.g. speculation
+ *    mitigations, etc.
+ * 4) Tell lockdep that interrupts are enabled
+ */
+static __always_inline void exit_to_user_mode(void)
+{
+	instrumentation_begin();
+	trace_hardirqs_on_prepare();
+	lockdep_hardirqs_on_prepare(CALLER_ADDR0);
+	instrumentation_end();
+
+	user_enter_irqoff();
+	arch_exit_to_user_mode();
+	lockdep_hardirqs_on(CALLER_ADDR0);
+}
+
+/* Workaround to allow gradual conversion of architecture code */
+void __weak arch_do_signal(struct pt_regs *regs) { }
+
+static unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
+					    unsigned long ti_work)
+{
+	/*
+	 * Before returning to user space ensure that all pending work
+	 * items have been completed.
+	 */
+	while (ti_work & EXIT_TO_USER_MODE_WORK) {
+
+		local_irq_enable_exit_to_user(ti_work);
+
+		if (ti_work & _TIF_NEED_RESCHED)
+			schedule();
+
+		if (ti_work & _TIF_UPROBE)
+			uprobe_notify_resume(regs);
+
+		if (ti_work & _TIF_PATCH_PENDING)
+			klp_update_patch_state(current);
+
+		if (ti_work & _TIF_SIGPENDING)
+			arch_do_signal(regs);
+
+		if (ti_work & _TIF_NOTIFY_RESUME) {
+			tracehook_notify_resume(regs);
+			rseq_handle_notify_resume(NULL, regs);
+		}
+
+		/* Architecture specific TIF work */
+		arch_exit_to_user_mode_work(regs, ti_work);
+
+		/*
+		 * Disable interrupts and reevaluate the work flags as they
+		 * might have changed while interrupts and preemption was
+		 * enabled above.
+		 */
+		local_irq_disable_exit_to_user();
+		ti_work = READ_ONCE(current_thread_info()->flags);
+	}
+
+	/* Return the latest work state for arch_exit_to_user_mode() */
+	return ti_work;
+}
+
+static void exit_to_user_mode_prepare(struct pt_regs *regs)
+{
+	unsigned long ti_work = READ_ONCE(current_thread_info()->flags);
+
+	lockdep_assert_irqs_disabled();
+
+	if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK))
+		ti_work = exit_to_user_mode_loop(regs, ti_work);
+
+	arch_exit_to_user_mode_prepare(regs, ti_work);
+
+	/* Ensure that the address limit is intact and no locks are held */
+	addr_limit_user_check();
+	lockdep_assert_irqs_disabled();
+	lockdep_sys_exit();
+}
+
+#ifndef _TIF_SINGLESTEP
+static inline bool report_single_step(unsigned long ti_work)
+{
+	return false;
+}
+#else
+/*
+ * If TIF_SYSCALL_EMU is set, then the only reason to report is when
+ * TIF_SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP).  This syscall
+ * instruction has been already reported in syscall_enter_from_user_mode().
+ */
+#define SYSEMU_STEP	(_TIF_SINGLESTEP | _TIF_SYSCALL_EMU)
+
+static inline bool report_single_step(unsigned long ti_work)
+{
+	return (ti_work & SYSEMU_STEP) == _TIF_SINGLESTEP;
+}
+#endif
+
+static void syscall_exit_work(struct pt_regs *regs, unsigned long ti_work)
+{
+	bool step;
+
+	audit_syscall_exit(regs);
+
+	if (ti_work & _TIF_SYSCALL_TRACEPOINT)
+		trace_sys_exit(regs, syscall_get_return_value(current, regs));
+
+	step = report_single_step(ti_work);
+	if (step || ti_work & _TIF_SYSCALL_TRACE)
+		arch_syscall_exit_tracehook(regs, step);
+}
+
+/*
+ * Syscall specific exit to user mode preparation. Runs with interrupts
+ * enabled.
+ */
+static void syscall_exit_to_user_mode_prepare(struct pt_regs *regs)
+{
+	u32 cached_flags = READ_ONCE(current_thread_info()->flags);
+	unsigned long nr = syscall_get_nr(current, regs);
+
+	CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
+
+	if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
+		if (WARN(irqs_disabled(), "syscall %lu left IRQs disabled", nr))
+			local_irq_enable();
+	}
+
+	rseq_syscall(regs);
+
+	/*
+	 * Do one-time syscall specific work. If these work items are
+	 * enabled, we want to run them exactly once per syscall exit with
+	 * interrupts enabled.
+	 */
+	if (unlikely(cached_flags & SYSCALL_EXIT_WORK))
+		syscall_exit_work(regs, cached_flags);
+}
+
+__visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs)
+{
+	instrumentation_begin();
+	syscall_exit_to_user_mode_prepare(regs);
+	local_irq_disable_exit_to_user();
+	exit_to_user_mode_prepare(regs);
+	instrumentation_end();
+	exit_to_user_mode();
+}
+
+noinstr void irqentry_enter_from_user_mode(struct pt_regs *regs)
+{
+	enter_from_user_mode(regs);
+}
+
+noinstr void irqentry_exit_to_user_mode(struct pt_regs *regs)
+{
+	instrumentation_begin();
+	exit_to_user_mode_prepare(regs);
+	instrumentation_end();
+	exit_to_user_mode();
+}
+
+noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
+{
+	irqentry_state_t ret = {
+		.exit_rcu = false,
+	};
+
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+		return ret;
+	}
+
+	/*
+	 * If this entry hit the idle task invoke rcu_irq_enter() whether
+	 * RCU is watching or not.
+	 *
+	 * Interupts can nest when the first interrupt invokes softirq
+	 * processing on return which enables interrupts.
+	 *
+	 * Scheduler ticks in the idle task can mark quiescent state and
+	 * terminate a grace period, if and only if the timer interrupt is
+	 * not nested into another interrupt.
+	 *
+	 * Checking for rcu_is_watching() here would prevent the nesting
+	 * interrupt to invoke rcu_irq_enter(). If that nested interrupt is
+	 * the tick then rcu_flavor_sched_clock_irq() would wrongfully
+	 * assume that it is the first interupt and eventually claim
+	 * quiescient state and end grace periods prematurely.
+	 *
+	 * Unconditionally invoke rcu_irq_enter() so RCU state stays
+	 * consistent.
+	 *
+	 * TINY_RCU does not support EQS, so let the compiler eliminate
+	 * this part when enabled.
+	 */
+	if (!IS_ENABLED(CONFIG_TINY_RCU) && is_idle_task(current)) {
+		/*
+		 * If RCU is not watching then the same careful
+		 * sequence vs. lockdep and tracing is required
+		 * as in irq_enter_from_user_mode().
+		 */
+		lockdep_hardirqs_off(CALLER_ADDR0);
+		rcu_irq_enter();
+		instrumentation_begin();
+		trace_hardirqs_off_finish();
+		instrumentation_end();
+
+		ret.exit_rcu = true;
+		return ret;
+	}
+
+	/*
+	 * If RCU is watching then RCU only wants to check whether it needs
+	 * to restart the tick in NOHZ mode. rcu_irq_enter_check_tick()
+	 * already contains a warning when RCU is not watching, so no point
+	 * in having another one here.
+	 */
+	lockdep_hardirqs_off(CALLER_ADDR0);
+	instrumentation_begin();
+	rcu_irq_enter_check_tick();
+	trace_hardirqs_off_finish();
+	instrumentation_end();
+
+	return ret;
+}
+
+void irqentry_exit_cond_resched(void)
+{
+	if (!preempt_count()) {
+		/* Sanity check RCU and thread stack */
+		rcu_irq_exit_check_preempt();
+		if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
+			WARN_ON_ONCE(!on_thread_stack());
+		if (need_resched())
+			preempt_schedule_irq();
+	}
+}
+
+noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state)
+{
+	lockdep_assert_irqs_disabled();
+
+	/* Check whether this returns to user mode */
+	if (user_mode(regs)) {
+		irqentry_exit_to_user_mode(regs);
+	} else if (!regs_irqs_disabled(regs)) {
+		/*
+		 * If RCU was not watching on entry this needs to be done
+		 * carefully and needs the same ordering of lockdep/tracing
+		 * and RCU as the return to user mode path.
+		 */
+		if (state.exit_rcu) {
+			instrumentation_begin();
+			/* Tell the tracer that IRET will enable interrupts */
+			trace_hardirqs_on_prepare();
+			lockdep_hardirqs_on_prepare(CALLER_ADDR0);
+			instrumentation_end();
+			rcu_irq_exit();
+			lockdep_hardirqs_on(CALLER_ADDR0);
+			return;
+		}
+
+		instrumentation_begin();
+		if (IS_ENABLED(CONFIG_PREEMPTION))
+			irqentry_exit_cond_resched();
+		/* Covers both tracing and lockdep */
+		trace_hardirqs_on();
+		instrumentation_end();
+	} else {
+		/*
+		 * IRQ flags state is correct already. Just tell RCU if it
+		 * was not watching on entry.
+		 */
+		if (state.exit_rcu)
+			rcu_irq_exit();
+	}
+}
+
+irqentry_state_t noinstr irqentry_nmi_enter(struct pt_regs *regs)
+{
+	irqentry_state_t irq_state;
+
+	irq_state.lockdep = lockdep_hardirqs_enabled();
+
+	__nmi_enter();
+	lockdep_hardirqs_off(CALLER_ADDR0);
+	lockdep_hardirq_enter();
+	rcu_nmi_enter();
+
+	instrumentation_begin();
+	trace_hardirqs_off_finish();
+	ftrace_nmi_enter();
+	instrumentation_end();
+
+	return irq_state;
+}
+
+void noinstr irqentry_nmi_exit(struct pt_regs *regs, irqentry_state_t irq_state)
+{
+	instrumentation_begin();
+	ftrace_nmi_exit();
+	if (irq_state.lockdep) {
+		trace_hardirqs_on_prepare();
+		lockdep_hardirqs_on_prepare(CALLER_ADDR0);
+	}
+	instrumentation_end();
+
+	rcu_nmi_exit();
+	lockdep_hardirq_exit();
+	if (irq_state.lockdep)
+		lockdep_hardirqs_on(CALLER_ADDR0);
+	__nmi_exit();
+}
diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
new file mode 100644
index 0000000..2a3139d
--- /dev/null
+++ b/kernel/entry/kvm.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/entry-kvm.h>
+#include <linux/kvm_host.h>
+
+static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
+{
+	do {
+		int ret;
+
+		if (ti_work & _TIF_SIGPENDING) {
+			kvm_handle_signal_exit(vcpu);
+			return -EINTR;
+		}
+
+		if (ti_work & _TIF_NEED_RESCHED)
+			schedule();
+
+		if (ti_work & _TIF_NOTIFY_RESUME) {
+			tracehook_notify_resume(NULL);
+			rseq_handle_notify_resume(NULL, NULL);
+		}
+
+		ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
+		if (ret)
+			return ret;
+
+		ti_work = READ_ONCE(current_thread_info()->flags);
+	} while (ti_work & XFER_TO_GUEST_MODE_WORK || need_resched());
+	return 0;
+}
+
+int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
+{
+	unsigned long ti_work;
+
+	/*
+	 * This is invoked from the outer guest loop with interrupts and
+	 * preemption enabled.
+	 *
+	 * KVM invokes xfer_to_guest_mode_work_pending() with interrupts
+	 * disabled in the inner loop before going into guest mode. No need
+	 * to disable interrupts here.
+	 */
+	ti_work = READ_ONCE(current_thread_info()->flags);
+	if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
+		return 0;
+
+	return xfer_to_guest_mode_work(vcpu, ti_work);
+}
+EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index c2b41a2..58cbe35 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -16,7 +16,7 @@
 
 struct callchain_cpus_entries {
 	struct rcu_head			rcu_head;
-	struct perf_callchain_entry	*cpu_entries[0];
+	struct perf_callchain_entry	*cpu_entries[];
 };
 
 int sysctl_perf_event_max_stack __read_mostly = PERF_MAX_STACK_DEPTH;
@@ -149,7 +149,7 @@
 	}
 }
 
-static struct perf_callchain_entry *get_callchain_entry(int *rctx)
+struct perf_callchain_entry *get_callchain_entry(int *rctx)
 {
 	int cpu;
 	struct callchain_cpus_entries *entries;
@@ -159,8 +159,10 @@
 		return NULL;
 
 	entries = rcu_dereference(callchain_cpus_entries);
-	if (!entries)
+	if (!entries) {
+		put_recursion_context(this_cpu_ptr(callchain_recursion), *rctx);
 		return NULL;
+	}
 
 	cpu = smp_processor_id();
 
@@ -168,7 +170,7 @@
 		(*rctx * perf_callchain_entry__sizeof()));
 }
 
-static void
+void
 put_callchain_entry(int rctx)
 {
 	put_recursion_context(this_cpu_ptr(callchain_recursion), rctx);
@@ -183,11 +185,8 @@
 	int rctx;
 
 	entry = get_callchain_entry(&rctx);
-	if (rctx == -1)
-		return NULL;
-
 	if (!entry)
-		goto exit_put;
+		return NULL;
 
 	ctx.entry     = entry;
 	ctx.max_stack = max_stack;
@@ -218,10 +217,9 @@
 			if (add_mark)
 				perf_callchain_store_context(&ctx, PERF_CONTEXT_USER);
 
-			fs = get_fs();
-			set_fs(USER_DS);
+			fs = force_uaccess_begin();
 			perf_callchain_user(&ctx, regs);
-			set_fs(fs);
+			force_uaccess_end(fs);
 		}
 	}
 
@@ -236,7 +234,7 @@
  * sysctl_perf_event_max_contexts_per_stack.
  */
 int perf_event_max_stack_handler(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *value = table->data;
 	int new_value = *value, ret;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1993a74..c8b3f94 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -28,6 +28,7 @@
 #include <linux/export.h>
 #include <linux/vmalloc.h>
 #include <linux/hardirq.h>
+#include <linux/hugetlb.h>
 #include <linux/rculist.h>
 #include <linux/uaccess.h>
 #include <linux/syscalls.h>
@@ -49,6 +50,7 @@
 #include <linux/sched/mm.h>
 #include <linux/proc_ns.h>
 #include <linux/mount.h>
+#include <linux/min_heap.h>
 
 #include "internal.h"
 
@@ -264,7 +266,7 @@
 	if (!event->parent) {
 		/*
 		 * If this is a !child event, we must hold ctx::mutex to
-		 * stabilize the the event->ctx relation. See
+		 * stabilize the event->ctx relation. See
 		 * perf_event_ctx_lock().
 		 */
 		lockdep_assert_held(&ctx->mutex);
@@ -392,6 +394,8 @@
 static atomic_t nr_switch_events __read_mostly;
 static atomic_t nr_ksymbol_events __read_mostly;
 static atomic_t nr_bpf_events __read_mostly;
+static atomic_t nr_cgroup_events __read_mostly;
+static atomic_t nr_text_poke_events __read_mostly;
 
 static LIST_HEAD(pmus);
 static DEFINE_MUTEX(pmus_lock);
@@ -440,8 +444,7 @@
 static bool perf_rotate_context(struct perf_cpu_context *cpuctx);
 
 int perf_proc_update_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	int perf_cpu = sysctl_perf_cpu_time_max_percent;
@@ -465,8 +468,7 @@
 int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
 
 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 
@@ -671,6 +673,23 @@
 	WRITE_ONCE(event->state, state);
 }
 
+/*
+ * UP store-release, load-acquire
+ */
+
+#define __store_release(ptr, val)					\
+do {									\
+	barrier();							\
+	WRITE_ONCE(*(ptr), (val));					\
+} while (0)
+
+#define __load_acquire(ptr)						\
+({									\
+	__unqual_scalar_typeof(*(ptr)) ___p = READ_ONCE(*(ptr));	\
+	barrier();							\
+	___p;								\
+})
+
 #ifdef CONFIG_CGROUP_PERF
 
 static inline bool
@@ -716,34 +735,51 @@
 	return t->time;
 }
 
-static inline void __update_cgrp_time(struct perf_cgroup *cgrp)
+static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now)
 {
-	struct perf_cgroup_info *info;
-	u64 now;
+	struct perf_cgroup_info *t;
 
-	now = perf_clock();
-
-	info = this_cpu_ptr(cgrp->info);
-
-	info->time += now - info->timestamp;
-	info->timestamp = now;
+	t = per_cpu_ptr(event->cgrp->info, event->cpu);
+	if (!__load_acquire(&t->active))
+		return t->time;
+	now += READ_ONCE(t->timeoffset);
+	return now;
 }
 
-static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
+static inline void __update_cgrp_time(struct perf_cgroup_info *info, u64 now, bool adv)
+{
+	if (adv)
+		info->time += now - info->timestamp;
+	info->timestamp = now;
+	/*
+	 * see update_context_time()
+	 */
+	WRITE_ONCE(info->timeoffset, info->time - info->timestamp);
+}
+
+static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx, bool final)
 {
 	struct perf_cgroup *cgrp = cpuctx->cgrp;
 	struct cgroup_subsys_state *css;
+	struct perf_cgroup_info *info;
 
 	if (cgrp) {
+		u64 now = perf_clock();
+
 		for (css = &cgrp->css; css; css = css->parent) {
 			cgrp = container_of(css, struct perf_cgroup, css);
-			__update_cgrp_time(cgrp);
+			info = this_cpu_ptr(cgrp->info);
+
+			__update_cgrp_time(info, now, true);
+			if (final)
+				__store_release(&info->active, 0);
 		}
 	}
 }
 
 static inline void update_cgrp_time_from_event(struct perf_event *event)
 {
+	struct perf_cgroup_info *info;
 	struct perf_cgroup *cgrp;
 
 	/*
@@ -757,8 +793,10 @@
 	/*
 	 * Do not update time when cgroup is not active
 	 */
-	if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup))
-		__update_cgrp_time(event->cgrp);
+	if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup)) {
+		info = this_cpu_ptr(event->cgrp->info);
+		__update_cgrp_time(info, perf_clock(), true);
+	}
 }
 
 static inline void
@@ -782,7 +820,8 @@
 	for (css = &cgrp->css; css; css = css->parent) {
 		cgrp = container_of(css, struct perf_cgroup, css);
 		info = this_cpu_ptr(cgrp->info);
-		info->timestamp = ctx->timestamp;
+		__update_cgrp_time(info, ctx->timestamp, false);
+		__store_release(&info->active, 1);
 	}
 }
 
@@ -799,7 +838,7 @@
  */
 static void perf_cgroup_switch(struct task_struct *task, int mode)
 {
-	struct perf_cpu_context *cpuctx;
+	struct perf_cpu_context *cpuctx, *tmp;
 	struct list_head *list;
 	unsigned long flags;
 
@@ -810,7 +849,7 @@
 	local_irq_save(flags);
 
 	list = this_cpu_ptr(&cgrp_cpuctx_list);
-	list_for_each_entry(cpuctx, list, cgrp_cpuctx_entry) {
+	list_for_each_entry_safe(cpuctx, tmp, list, cgrp_cpuctx_entry) {
 		WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0);
 
 		perf_ctx_lock(cpuctx, cpuctx->task_ctx);
@@ -897,6 +936,47 @@
 	rcu_read_unlock();
 }
 
+static int perf_cgroup_ensure_storage(struct perf_event *event,
+				struct cgroup_subsys_state *css)
+{
+	struct perf_cpu_context *cpuctx;
+	struct perf_event **storage;
+	int cpu, heap_size, ret = 0;
+
+	/*
+	 * Allow storage to have sufficent space for an iterator for each
+	 * possibly nested cgroup plus an iterator for events with no cgroup.
+	 */
+	for (heap_size = 1; css; css = css->parent)
+		heap_size++;
+
+	for_each_possible_cpu(cpu) {
+		cpuctx = per_cpu_ptr(event->pmu->pmu_cpu_context, cpu);
+		if (heap_size <= cpuctx->heap_size)
+			continue;
+
+		storage = kmalloc_node(heap_size * sizeof(struct perf_event *),
+				       GFP_KERNEL, cpu_to_node(cpu));
+		if (!storage) {
+			ret = -ENOMEM;
+			break;
+		}
+
+		raw_spin_lock_irq(&cpuctx->ctx.lock);
+		if (cpuctx->heap_size < heap_size) {
+			swap(cpuctx->heap, storage);
+			if (storage == cpuctx->heap_default)
+				storage = NULL;
+			cpuctx->heap_size = heap_size;
+		}
+		raw_spin_unlock_irq(&cpuctx->ctx.lock);
+
+		kfree(storage);
+	}
+
+	return ret;
+}
+
 static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 				      struct perf_event_attr *attr,
 				      struct perf_event *group_leader)
@@ -916,6 +996,10 @@
 		goto out;
 	}
 
+	ret = perf_cgroup_ensure_storage(event, css);
+	if (ret)
+		goto out;
+
 	cgrp = container_of(css, struct perf_cgroup, css);
 	event->cgrp = cgrp;
 
@@ -934,32 +1018,18 @@
 }
 
 static inline void
-perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
-{
-	struct perf_cgroup_info *t;
-	t = per_cpu_ptr(event->cgrp->info, event->cpu);
-	event->shadow_ctx_time = now - t->timestamp;
-}
-
-/*
- * Update cpuctx->cgrp so that it is set when first cgroup event is added and
- * cleared when last cgroup event is removed.
- */
-static inline void
-list_update_cgroup_event(struct perf_event *event,
-			 struct perf_event_context *ctx, bool add)
+perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
 {
 	struct perf_cpu_context *cpuctx;
-	struct list_head *cpuctx_entry;
 
 	if (!is_cgroup_event(event))
 		return;
 
 	/*
 	 * Because cgroup events are always per-cpu events,
-	 * this will always be called from the right CPU.
+	 * @ctx == &cpuctx->ctx.
 	 */
-	cpuctx = __get_cpu_context(ctx);
+	cpuctx = container_of(ctx, struct perf_cpu_context, ctx);
 
 	/*
 	 * Since setting cpuctx->cgrp is conditional on the current @cgrp
@@ -967,27 +1037,41 @@
 	 * because if the first would mismatch, the second would not try again
 	 * and we would leave cpuctx->cgrp unset.
 	 */
-	if (add && !cpuctx->cgrp) {
+	if (ctx->is_active && !cpuctx->cgrp) {
 		struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);
 
 		if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup))
 			cpuctx->cgrp = cgrp;
 	}
 
-	if (add && ctx->nr_cgroups++)
-		return;
-	else if (!add && --ctx->nr_cgroups)
+	if (ctx->nr_cgroups++)
 		return;
 
-	/* no cgroup running */
-	if (!add)
+	list_add(&cpuctx->cgrp_cpuctx_entry,
+			per_cpu_ptr(&cgrp_cpuctx_list, event->cpu));
+}
+
+static inline void
+perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
+{
+	struct perf_cpu_context *cpuctx;
+
+	if (!is_cgroup_event(event))
+		return;
+
+	/*
+	 * Because cgroup events are always per-cpu events,
+	 * @ctx == &cpuctx->ctx.
+	 */
+	cpuctx = container_of(ctx, struct perf_cpu_context, ctx);
+
+	if (--ctx->nr_cgroups)
+		return;
+
+	if (ctx->is_active && cpuctx->cgrp)
 		cpuctx->cgrp = NULL;
 
-	cpuctx_entry = &cpuctx->cgrp_cpuctx_entry;
-	if (add)
-		list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list));
-	else
-		list_del(cpuctx_entry);
+	list_del(&cpuctx->cgrp_cpuctx_entry);
 }
 
 #else /* !CONFIG_CGROUP_PERF */
@@ -1010,7 +1094,8 @@
 {
 }
 
-static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
+static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx,
+						bool final)
 {
 }
 
@@ -1042,22 +1127,25 @@
 {
 }
 
-static inline void
-perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
-{
-}
-
 static inline u64 perf_cgroup_event_time(struct perf_event *event)
 {
 	return 0;
 }
 
+static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now)
+{
+	return 0;
+}
+
 static inline void
-list_update_cgroup_event(struct perf_event *event,
-			 struct perf_event_context *ctx, bool add)
+perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
 {
 }
 
+static inline void
+perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
+{
+}
 #endif
 
 /*
@@ -1181,12 +1269,26 @@
 	refcount_inc(&ctx->refcount);
 }
 
+static void *alloc_task_ctx_data(struct pmu *pmu)
+{
+	if (pmu->task_ctx_cache)
+		return kmem_cache_zalloc(pmu->task_ctx_cache, GFP_KERNEL);
+
+	return NULL;
+}
+
+static void free_task_ctx_data(struct pmu *pmu, void *task_ctx_data)
+{
+	if (pmu->task_ctx_cache && task_ctx_data)
+		kmem_cache_free(pmu->task_ctx_cache, task_ctx_data);
+}
+
 static void free_ctx(struct rcu_head *head)
 {
 	struct perf_event_context *ctx;
 
 	ctx = container_of(head, struct perf_event_context, rcu_head);
-	kfree(ctx->task_ctx_data);
+	free_task_ctx_data(ctx->pmu, ctx->task_ctx_data);
 	kfree(ctx);
 }
 
@@ -1228,7 +1330,7 @@
  * life-time rules separate them. That is an exiting task cannot fork, and a
  * spawning task cannot (yet) exit.
  *
- * But remember that that these are parent<->child context relations, and
+ * But remember that these are parent<->child context relations, and
  * migration does not affect children, therefore these two orderings should not
  * interact.
  *
@@ -1260,7 +1362,7 @@
  *	    perf_event::child_mutex;
  *	      perf_event_context::lock
  *	    perf_event::mmap_mutex
- *	    mmap_sem
+ *	    mmap_lock
  *	      perf_addr_filters_head::lock
  *
  *    cpu_hotplug_lock
@@ -1367,7 +1469,7 @@
 /*
  * Get the perf_event_context for a task and lock it.
  *
- * This has to cope with with the fact that until it is locked,
+ * This has to cope with the fact that until it is locked,
  * the context could get moved to another task.
  */
 static struct perf_event_context *
@@ -1452,22 +1554,59 @@
 /*
  * Update the record of the current time in a context.
  */
-static void update_context_time(struct perf_event_context *ctx)
+static void __update_context_time(struct perf_event_context *ctx, bool adv)
 {
 	u64 now = perf_clock();
 
-	ctx->time += now - ctx->timestamp;
+	if (adv)
+		ctx->time += now - ctx->timestamp;
 	ctx->timestamp = now;
+
+	/*
+	 * The above: time' = time + (now - timestamp), can be re-arranged
+	 * into: time` = now + (time - timestamp), which gives a single value
+	 * offset to compute future time without locks on.
+	 *
+	 * See perf_event_time_now(), which can be used from NMI context where
+	 * it's (obviously) not possible to acquire ctx->lock in order to read
+	 * both the above values in a consistent manner.
+	 */
+	WRITE_ONCE(ctx->timeoffset, ctx->time - ctx->timestamp);
+}
+
+static void update_context_time(struct perf_event_context *ctx)
+{
+	__update_context_time(ctx, true);
 }
 
 static u64 perf_event_time(struct perf_event *event)
 {
 	struct perf_event_context *ctx = event->ctx;
 
+	if (unlikely(!ctx))
+		return 0;
+
 	if (is_cgroup_event(event))
 		return perf_cgroup_event_time(event);
 
-	return ctx ? ctx->time : 0;
+	return ctx->time;
+}
+
+static u64 perf_event_time_now(struct perf_event *event, u64 now)
+{
+	struct perf_event_context *ctx = event->ctx;
+
+	if (unlikely(!ctx))
+		return 0;
+
+	if (is_cgroup_event(event))
+		return perf_cgroup_event_time_now(event, now);
+
+	if (!(__load_acquire(&ctx->is_active) & EVENT_TIME))
+		return ctx->time;
+
+	now += READ_ONCE(ctx->timeoffset);
+	return now;
 }
 
 static enum event_type_t get_event_type(struct perf_event *event)
@@ -1536,6 +1675,30 @@
 	if (left->cpu > right->cpu)
 		return false;
 
+#ifdef CONFIG_CGROUP_PERF
+	if (left->cgrp != right->cgrp) {
+		if (!left->cgrp || !left->cgrp->css.cgroup) {
+			/*
+			 * Left has no cgroup but right does, no cgroups come
+			 * first.
+			 */
+			return true;
+		}
+		if (!right->cgrp || !right->cgrp->css.cgroup) {
+			/*
+			 * Right has no cgroup but left does, no cgroups come
+			 * first.
+			 */
+			return false;
+		}
+		/* Two dissimilar cgroups, order by id. */
+		if (left->cgrp->css.cgroup->kn->id < right->cgrp->css.cgroup->kn->id)
+			return true;
+
+		return false;
+	}
+#endif
+
 	if (left->group_index < right->group_index)
 		return true;
 	if (left->group_index > right->group_index)
@@ -1615,25 +1778,48 @@
 }
 
 /*
- * Get the leftmost event in the @cpu subtree.
+ * Get the leftmost event in the cpu/cgroup subtree.
  */
 static struct perf_event *
-perf_event_groups_first(struct perf_event_groups *groups, int cpu)
+perf_event_groups_first(struct perf_event_groups *groups, int cpu,
+			struct cgroup *cgrp)
 {
 	struct perf_event *node_event = NULL, *match = NULL;
 	struct rb_node *node = groups->tree.rb_node;
+#ifdef CONFIG_CGROUP_PERF
+	u64 node_cgrp_id, cgrp_id = 0;
+
+	if (cgrp)
+		cgrp_id = cgrp->kn->id;
+#endif
 
 	while (node) {
 		node_event = container_of(node, struct perf_event, group_node);
 
 		if (cpu < node_event->cpu) {
 			node = node->rb_left;
-		} else if (cpu > node_event->cpu) {
-			node = node->rb_right;
-		} else {
-			match = node_event;
-			node = node->rb_left;
+			continue;
 		}
+		if (cpu > node_event->cpu) {
+			node = node->rb_right;
+			continue;
+		}
+#ifdef CONFIG_CGROUP_PERF
+		node_cgrp_id = 0;
+		if (node_event->cgrp && node_event->cgrp->css.cgroup)
+			node_cgrp_id = node_event->cgrp->css.cgroup->kn->id;
+
+		if (cgrp_id < node_cgrp_id) {
+			node = node->rb_left;
+			continue;
+		}
+		if (cgrp_id > node_cgrp_id) {
+			node = node->rb_right;
+			continue;
+		}
+#endif
+		match = node_event;
+		node = node->rb_left;
 	}
 
 	return match;
@@ -1646,12 +1832,26 @@
 perf_event_groups_next(struct perf_event *event)
 {
 	struct perf_event *next;
+#ifdef CONFIG_CGROUP_PERF
+	u64 curr_cgrp_id = 0;
+	u64 next_cgrp_id = 0;
+#endif
 
 	next = rb_entry_safe(rb_next(&event->group_node), typeof(*event), group_node);
-	if (next && next->cpu == event->cpu)
-		return next;
+	if (next == NULL || next->cpu != event->cpu)
+		return NULL;
 
-	return NULL;
+#ifdef CONFIG_CGROUP_PERF
+	if (event->cgrp && event->cgrp->css.cgroup)
+		curr_cgrp_id = event->cgrp->css.cgroup->kn->id;
+
+	if (next->cgrp && next->cgrp->css.cgroup)
+		next_cgrp_id = next->cgrp->css.cgroup->kn->id;
+
+	if (curr_cgrp_id != next_cgrp_id)
+		return NULL;
+#endif
+	return next;
 }
 
 /*
@@ -1687,13 +1887,14 @@
 		add_event_to_groups(event, ctx);
 	}
 
-	list_update_cgroup_event(event, ctx, true);
-
 	list_add_rcu(&event->event_entry, &ctx->event_list);
 	ctx->nr_events++;
 	if (event->attr.inherit_stat)
 		ctx->nr_stat++;
 
+	if (event->state > PERF_EVENT_STATE_OFF)
+		perf_cgroup_event_enable(event, ctx);
+
 	ctx->generation++;
 }
 
@@ -1759,6 +1960,9 @@
 	if (sample_type & PERF_SAMPLE_PHYS_ADDR)
 		size += sizeof(data->phys_addr);
 
+	if (sample_type & PERF_SAMPLE_CGROUP)
+		size += sizeof(data->cgroup);
+
 	event->header_size = size;
 }
 
@@ -1869,8 +2073,6 @@
 
 	event->attach_state &= ~PERF_ATTACH_CONTEXT;
 
-	list_update_cgroup_event(event, ctx, false);
-
 	ctx->nr_events--;
 	if (event->attr.inherit_stat)
 		ctx->nr_stat--;
@@ -1887,8 +2089,10 @@
 	 * of error state is by explicit re-enabling
 	 * of the event
 	 */
-	if (event->state > PERF_EVENT_STATE_OFF)
+	if (event->state > PERF_EVENT_STATE_OFF) {
+		perf_cgroup_event_disable(event, ctx);
 		perf_event_set_state(event, PERF_EVENT_STATE_OFF);
+	}
 
 	ctx->generation++;
 }
@@ -1947,6 +2151,11 @@
 	}
 }
 
+static bool perf_need_aux_event(struct perf_event *event)
+{
+	return !!event->attr.aux_output || !!event->attr.aux_sample_size;
+}
+
 static int perf_get_aux_event(struct perf_event *event,
 			      struct perf_event *group_leader)
 {
@@ -1959,7 +2168,17 @@
 	if (!group_leader)
 		return 0;
 
-	if (!perf_aux_output_match(event, group_leader))
+	/*
+	 * aux_output and aux_sample_size are mutually exclusive.
+	 */
+	if (event->attr.aux_output && event->attr.aux_sample_size)
+		return 0;
+
+	if (event->attr.aux_output &&
+	    !perf_aux_output_match(event, group_leader))
+		return 0;
+
+	if (event->attr.aux_sample_size && !group_leader->pmu->snapshot_aux)
 		return 0;
 
 	if (!atomic_long_inc_not_zero(&group_leader->refcount))
@@ -1976,8 +2195,30 @@
 	return 1;
 }
 
+static inline struct list_head *get_event_list(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	return event->attr.pinned ? &ctx->pinned_active : &ctx->flexible_active;
+}
+
+/*
+ * Events that have PERF_EV_CAP_SIBLING require being part of a group and
+ * cannot exist on their own, schedule them out and move them into the ERROR
+ * state. Also see _perf_event_enable(), it will not be able to recover
+ * this ERROR state.
+ */
+static inline void perf_remove_sibling_event(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+
+	event_sched_out(event, cpuctx, ctx);
+	perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
+}
+
 static void perf_group_detach(struct perf_event *event)
 {
+	struct perf_event *leader = event->group_leader;
 	struct perf_event *sibling, *tmp;
 	struct perf_event_context *ctx = event->ctx;
 
@@ -1996,7 +2237,7 @@
 	/*
 	 * If this is a sibling, remove it from its group.
 	 */
-	if (event->group_leader != event) {
+	if (leader != event) {
 		list_del_init(&event->sibling_list);
 		event->group_leader->nr_siblings--;
 		goto out;
@@ -2009,6 +2250,9 @@
 	 */
 	list_for_each_entry_safe(sibling, tmp, &event->sibling_list, sibling_list) {
 
+		if (sibling->event_caps & PERF_EV_CAP_SIBLING)
+			perf_remove_sibling_event(sibling);
+
 		sibling->group_leader = sibling;
 		list_del_init(&sibling->sibling_list);
 
@@ -2018,22 +2262,18 @@
 		if (!RB_EMPTY_NODE(&event->group_node)) {
 			add_event_to_groups(sibling, event->ctx);
 
-			if (sibling->state == PERF_EVENT_STATE_ACTIVE) {
-				struct list_head *list = sibling->attr.pinned ?
-					&ctx->pinned_active : &ctx->flexible_active;
-
-				list_add_tail(&sibling->active_list, list);
-			}
+			if (sibling->state == PERF_EVENT_STATE_ACTIVE)
+				list_add_tail(&sibling->active_list, get_event_list(sibling));
 		}
 
 		WARN_ON_ONCE(sibling->ctx != event->ctx);
 	}
 
 out:
-	perf_event__header_size(event->group_leader);
-
-	for_each_sibling_event(tmp, event->group_leader)
+	for_each_sibling_event(tmp, leader)
 		perf_event__header_size(tmp);
+
+	perf_event__header_size(leader);
 }
 
 static bool is_orphaned_event(struct perf_event *event)
@@ -2102,6 +2342,7 @@
 
 	if (READ_ONCE(event->pending_disable) >= 0) {
 		WRITE_ONCE(event->pending_disable, -1);
+		perf_cgroup_event_disable(event, ctx);
 		state = PERF_EVENT_STATE_OFF;
 	}
 	perf_event_set_state(event, state);
@@ -2139,9 +2380,6 @@
 		event_sched_out(event, cpuctx, ctx);
 
 	perf_pmu_enable(ctx->pmu);
-
-	if (group_event->attr.exclusive)
-		cpuctx->exclusive = 0;
 }
 
 #define DETACH_GROUP	0x01UL
@@ -2162,7 +2400,7 @@
 
 	if (ctx->is_active & EVENT_TIME) {
 		update_context_time(ctx);
-		update_cgrp_time_from_cpuctx(cpuctx);
+		update_cgrp_time_from_cpuctx(cpuctx, false);
 	}
 
 	event_sched_out(event, cpuctx, ctx);
@@ -2171,6 +2409,9 @@
 	list_del_event(event, ctx);
 
 	if (!ctx->nr_events && ctx->is_active) {
+		if (ctx == &cpuctx->ctx)
+			update_cgrp_time_from_cpuctx(cpuctx, true);
+
 		ctx->is_active = 0;
 		ctx->rotate_necessary = 0;
 		if (ctx->task) {
@@ -2239,6 +2480,7 @@
 		event_sched_out(event, cpuctx, ctx);
 
 	perf_event_set_state(event, PERF_EVENT_STATE_OFF);
+	perf_cgroup_event_disable(event, ctx);
 }
 
 /*
@@ -2295,40 +2537,6 @@
 	irq_work_queue(&event->pending);
 }
 
-static void perf_set_shadow_time(struct perf_event *event,
-				 struct perf_event_context *ctx)
-{
-	/*
-	 * use the correct time source for the time snapshot
-	 *
-	 * We could get by without this by leveraging the
-	 * fact that to get to this function, the caller
-	 * has most likely already called update_context_time()
-	 * and update_cgrp_time_xx() and thus both timestamp
-	 * are identical (or very close). Given that tstamp is,
-	 * already adjusted for cgroup, we could say that:
-	 *    tstamp - ctx->timestamp
-	 * is equivalent to
-	 *    tstamp - cgrp->timestamp.
-	 *
-	 * Then, in perf_output_read(), the calculation would
-	 * work with no changes because:
-	 * - event is guaranteed scheduled in
-	 * - no scheduled out in between
-	 * - thus the timestamp would be the same
-	 *
-	 * But this is a bit hairy.
-	 *
-	 * So instead, we have an explicit cgroup call to remain
-	 * within the time time source all along. We believe it
-	 * is cleaner and simpler to understand.
-	 */
-	if (is_cgroup_event(event))
-		perf_cgroup_set_shadow_time(event, event->tstamp);
-	else
-		event->shadow_ctx_time = event->tstamp - ctx->timestamp;
-}
-
 #define MAX_INTERRUPTS (~0ULL)
 
 static void perf_log_throttle(struct perf_event *event, int enable);
@@ -2341,6 +2549,8 @@
 {
 	int ret = 0;
 
+	WARN_ON_ONCE(event->ctx != ctx);
+
 	lockdep_assert_held(&ctx->lock);
 
 	if (event->state <= PERF_EVENT_STATE_OFF)
@@ -2367,8 +2577,6 @@
 
 	perf_pmu_disable(event->pmu);
 
-	perf_set_shadow_time(event, ctx);
-
 	perf_log_itrace_start(event);
 
 	if (event->pmu->add(event, PERF_EF_START)) {
@@ -2407,11 +2615,8 @@
 
 	pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
 
-	if (event_sched_in(group_event, cpuctx, ctx)) {
-		pmu->cancel_txn(pmu);
-		perf_mux_hrtimer_restart(cpuctx);
-		return -EAGAIN;
-	}
+	if (event_sched_in(group_event, cpuctx, ctx))
+		goto error;
 
 	/*
 	 * Schedule in siblings as one group (if any):
@@ -2440,10 +2645,8 @@
 	}
 	event_sched_out(group_event, cpuctx, ctx);
 
+error:
 	pmu->cancel_txn(pmu);
-
-	perf_mux_hrtimer_restart(cpuctx);
-
 	return -EAGAIN;
 }
 
@@ -2469,7 +2672,7 @@
 	 * If this group is exclusive and there are already
 	 * events on the CPU, it can't go on.
 	 */
-	if (event->attr.exclusive && cpuctx->active_oncpu)
+	if (event->attr.exclusive && !list_empty(get_event_list(event)))
 		return 0;
 	/*
 	 * Otherwise, try to add it if all previous groups were able
@@ -2620,7 +2823,7 @@
 	}
 
 #ifdef CONFIG_CGROUP_PERF
-	if (is_cgroup_event(event)) {
+	if (event->state > PERF_EVENT_STATE_OFF && is_cgroup_event(event)) {
 		/*
 		 * If the current cgroup doesn't match the event's
 		 * cgroup, we should not try to schedule it.
@@ -2673,6 +2876,25 @@
 	 */
 	smp_store_release(&event->ctx, ctx);
 
+	/*
+	 * perf_event_attr::disabled events will not run and can be initialized
+	 * without IPI. Except when this is the first event for the context, in
+	 * that case we need the magic of the IPI to set ctx->is_active.
+	 *
+	 * The IOC_ENABLE that is sure to follow the creation of a disabled
+	 * event will issue the IPI and reprogram the hardware.
+	 */
+	if (__perf_effective_state(event) == PERF_EVENT_STATE_OFF && ctx->nr_events) {
+		raw_spin_lock_irq(&ctx->lock);
+		if (ctx->task == TASK_TOMBSTONE) {
+			raw_spin_unlock_irq(&ctx->lock);
+			return;
+		}
+		add_event_to_ctx(event, ctx);
+		raw_spin_unlock_irq(&ctx->lock);
+		return;
+	}
+
 	if (!task) {
 		cpu_function_call(cpu, __perf_install_in_context, event);
 		return;
@@ -2761,6 +2983,7 @@
 		ctx_sched_out(ctx, cpuctx, EVENT_TIME);
 
 	perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
+	perf_cgroup_event_enable(event, ctx);
 
 	if (!ctx->is_active)
 		return;
@@ -2802,6 +3025,7 @@
 	raw_spin_lock_irq(&ctx->lock);
 	if (event->state >= PERF_EVENT_STATE_INACTIVE ||
 	    event->state <  PERF_EVENT_STATE_ERROR) {
+out:
 		raw_spin_unlock_irq(&ctx->lock);
 		return;
 	}
@@ -2813,8 +3037,16 @@
 	 * has gone back into error state, as distinct from the task having
 	 * been scheduled away before the cross-call arrived.
 	 */
-	if (event->state == PERF_EVENT_STATE_ERROR)
+	if (event->state == PERF_EVENT_STATE_ERROR) {
+		/*
+		 * Detached SIBLING events cannot leave ERROR state.
+		 */
+		if (event->event_caps & PERF_EV_CAP_SIBLING &&
+		    event->group_leader == event)
+			goto out;
+
 		event->state = PERF_EVENT_STATE_OFF;
+	}
 	raw_spin_unlock_irq(&ctx->lock);
 
 	event_function_call(event, __perf_event_enable, NULL);
@@ -2918,7 +3150,7 @@
  *     pre-existing mappings, called once when new filters arrive via SET_FILTER
  *     ioctl;
  * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
- *     registered mapping, called for every new mmap(), with mm::mmap_sem down
+ *     registered mapping, called for every new mmap(), with mm::mmap_lock down
  *     for reading;
  * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
  *     of exec.
@@ -3018,16 +3250,6 @@
 		return;
 	}
 
-	ctx->is_active &= ~event_type;
-	if (!(ctx->is_active & EVENT_ALL))
-		ctx->is_active = 0;
-
-	if (ctx->task) {
-		WARN_ON_ONCE(cpuctx->task_ctx != ctx);
-		if (!ctx->is_active)
-			cpuctx->task_ctx = NULL;
-	}
-
 	/*
 	 * Always update time if it was set; not only when it changes.
 	 * Otherwise we can 'forget' to update time for any but the last
@@ -3041,7 +3263,22 @@
 	if (is_active & EVENT_TIME) {
 		/* update (and stop) ctx time */
 		update_context_time(ctx);
-		update_cgrp_time_from_cpuctx(cpuctx);
+		update_cgrp_time_from_cpuctx(cpuctx, ctx == &cpuctx->ctx);
+		/*
+		 * CPU-release for the below ->is_active store,
+		 * see __load_acquire() in perf_event_time_now()
+		 */
+		barrier();
+	}
+
+	ctx->is_active &= ~event_type;
+	if (!(ctx->is_active & EVENT_ALL))
+		ctx->is_active = 0;
+
+	if (ctx->task) {
+		WARN_ON_ONCE(cpuctx->task_ctx != ctx);
+		if (!ctx->is_active)
+			cpuctx->task_ctx = NULL;
 	}
 
 	is_active ^= ctx->is_active; /* changed bits */
@@ -3179,10 +3416,12 @@
 	struct perf_event_context *parent, *next_parent;
 	struct perf_cpu_context *cpuctx;
 	int do_switch = 1;
+	struct pmu *pmu;
 
 	if (likely(!ctx))
 		return;
 
+	pmu = ctx->pmu;
 	cpuctx = __get_cpu_context(ctx);
 	if (!cpuctx->task_ctx)
 		return;
@@ -3212,10 +3451,27 @@
 		raw_spin_lock(&ctx->lock);
 		raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
 		if (context_equiv(ctx, next_ctx)) {
+
 			WRITE_ONCE(ctx->task, next);
 			WRITE_ONCE(next_ctx->task, task);
 
-			swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
+			perf_pmu_disable(pmu);
+
+			if (cpuctx->sched_cb_usage && pmu->sched_task)
+				pmu->sched_task(ctx, false);
+
+			/*
+			 * PMU specific parts of task perf context can require
+			 * additional synchronization. As an example of such
+			 * synchronization see implementation details of Intel
+			 * LBR call stack data profiling;
+			 */
+			if (pmu->swap_task_ctx)
+				pmu->swap_task_ctx(ctx, next_ctx);
+			else
+				swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
+
+			perf_pmu_enable(pmu);
 
 			/*
 			 * RCU_INIT_POINTER here is safe because we've not
@@ -3239,7 +3495,13 @@
 
 	if (do_switch) {
 		raw_spin_lock(&ctx->lock);
+		perf_pmu_disable(pmu);
+
+		if (cpuctx->sched_cb_usage && pmu->sched_task)
+			pmu->sched_task(ctx, false);
 		task_ctx_sched_out(cpuctx, ctx, EVENT_ALL);
+
+		perf_pmu_enable(pmu);
 		raw_spin_unlock(&ctx->lock);
 	}
 }
@@ -3275,29 +3537,39 @@
  * PEBS requires this to provide PID/TID information. This requires we flush
  * all queued PEBS records before we context switch to a new task.
  */
+static void __perf_pmu_sched_task(struct perf_cpu_context *cpuctx, bool sched_in)
+{
+	struct pmu *pmu;
+
+	pmu = cpuctx->ctx.pmu; /* software PMUs will not have sched_task */
+
+	if (WARN_ON_ONCE(!pmu->sched_task))
+		return;
+
+	perf_ctx_lock(cpuctx, cpuctx->task_ctx);
+	perf_pmu_disable(pmu);
+
+	pmu->sched_task(cpuctx->task_ctx, sched_in);
+
+	perf_pmu_enable(pmu);
+	perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
+}
+
 static void perf_pmu_sched_task(struct task_struct *prev,
 				struct task_struct *next,
 				bool sched_in)
 {
 	struct perf_cpu_context *cpuctx;
-	struct pmu *pmu;
 
 	if (prev == next)
 		return;
 
 	list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) {
-		pmu = cpuctx->ctx.pmu; /* software PMUs will not have sched_task */
-
-		if (WARN_ON_ONCE(!pmu->sched_task))
+		/* will be handled in perf_event_context_sched_in/out */
+		if (cpuctx->task_ctx)
 			continue;
 
-		perf_ctx_lock(cpuctx, cpuctx->task_ctx);
-		perf_pmu_disable(pmu);
-
-		pmu->sched_task(cpuctx->task_ctx, sched_in);
-
-		perf_pmu_enable(pmu);
-		perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
+		__perf_pmu_sched_task(cpuctx, sched_in);
 	}
 }
 
@@ -3350,46 +3622,133 @@
 	ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
 }
 
-static int visit_groups_merge(struct perf_event_groups *groups, int cpu,
-			      int (*func)(struct perf_event *, void *), void *data)
+static bool perf_less_group_idx(const void *l, const void *r)
 {
-	struct perf_event **evt, *evt1, *evt2;
+	const struct perf_event *le = *(const struct perf_event **)l;
+	const struct perf_event *re = *(const struct perf_event **)r;
+
+	return le->group_index < re->group_index;
+}
+
+static void swap_ptr(void *l, void *r)
+{
+	void **lp = l, **rp = r;
+
+	swap(*lp, *rp);
+}
+
+static const struct min_heap_callbacks perf_min_heap = {
+	.elem_size = sizeof(struct perf_event *),
+	.less = perf_less_group_idx,
+	.swp = swap_ptr,
+};
+
+static void __heap_add(struct min_heap *heap, struct perf_event *event)
+{
+	struct perf_event **itrs = heap->data;
+
+	if (event) {
+		itrs[heap->nr] = event;
+		heap->nr++;
+	}
+}
+
+static noinline int visit_groups_merge(struct perf_cpu_context *cpuctx,
+				struct perf_event_groups *groups, int cpu,
+				int (*func)(struct perf_event *, void *),
+				void *data)
+{
+#ifdef CONFIG_CGROUP_PERF
+	struct cgroup_subsys_state *css = NULL;
+#endif
+	/* Space for per CPU and/or any CPU event iterators. */
+	struct perf_event *itrs[2];
+	struct min_heap event_heap;
+	struct perf_event **evt;
 	int ret;
 
-	evt1 = perf_event_groups_first(groups, -1);
-	evt2 = perf_event_groups_first(groups, cpu);
+	if (cpuctx) {
+		event_heap = (struct min_heap){
+			.data = cpuctx->heap,
+			.nr = 0,
+			.size = cpuctx->heap_size,
+		};
 
-	while (evt1 || evt2) {
-		if (evt1 && evt2) {
-			if (evt1->group_index < evt2->group_index)
-				evt = &evt1;
-			else
-				evt = &evt2;
-		} else if (evt1) {
-			evt = &evt1;
-		} else {
-			evt = &evt2;
-		}
+		lockdep_assert_held(&cpuctx->ctx.lock);
 
+#ifdef CONFIG_CGROUP_PERF
+		if (cpuctx->cgrp)
+			css = &cpuctx->cgrp->css;
+#endif
+	} else {
+		event_heap = (struct min_heap){
+			.data = itrs,
+			.nr = 0,
+			.size = ARRAY_SIZE(itrs),
+		};
+		/* Events not within a CPU context may be on any CPU. */
+		__heap_add(&event_heap, perf_event_groups_first(groups, -1, NULL));
+	}
+	evt = event_heap.data;
+
+	__heap_add(&event_heap, perf_event_groups_first(groups, cpu, NULL));
+
+#ifdef CONFIG_CGROUP_PERF
+	for (; css; css = css->parent)
+		__heap_add(&event_heap, perf_event_groups_first(groups, cpu, css->cgroup));
+#endif
+
+	min_heapify_all(&event_heap, &perf_min_heap);
+
+	while (event_heap.nr) {
 		ret = func(*evt, data);
 		if (ret)
 			return ret;
 
 		*evt = perf_event_groups_next(*evt);
+		if (*evt)
+			min_heapify(&event_heap, 0, &perf_min_heap);
+		else
+			min_heap_pop(&event_heap, &perf_min_heap);
 	}
 
 	return 0;
 }
 
-struct sched_in_data {
-	struct perf_event_context *ctx;
-	struct perf_cpu_context *cpuctx;
-	int can_add_hw;
-};
-
-static int pinned_sched_in(struct perf_event *event, void *data)
+/*
+ * Because the userpage is strictly per-event (there is no concept of context,
+ * so there cannot be a context indirection), every userpage must be updated
+ * when context time starts :-(
+ *
+ * IOW, we must not miss EVENT_TIME edges.
+ */
+static inline bool event_update_userpage(struct perf_event *event)
 {
-	struct sched_in_data *sid = data;
+	if (likely(!atomic_read(&event->mmap_count)))
+		return false;
+
+	perf_event_update_time(event);
+	perf_event_update_userpage(event);
+
+	return true;
+}
+
+static inline void group_update_userpage(struct perf_event *group_event)
+{
+	struct perf_event *event;
+
+	if (!event_update_userpage(group_event))
+		return;
+
+	for_each_sibling_event(event, group_event)
+		event_update_userpage(event);
+}
+
+static int merge_sched_in(struct perf_event *event, void *data)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+	int *can_add_hw = data;
 
 	if (event->state <= PERF_EVENT_STATE_OFF)
 		return 0;
@@ -3397,39 +3756,21 @@
 	if (!event_filter_match(event))
 		return 0;
 
-	if (group_can_go_on(event, sid->cpuctx, sid->can_add_hw)) {
-		if (!group_sched_in(event, sid->cpuctx, sid->ctx))
-			list_add_tail(&event->active_list, &sid->ctx->pinned_active);
+	if (group_can_go_on(event, cpuctx, *can_add_hw)) {
+		if (!group_sched_in(event, cpuctx, ctx))
+			list_add_tail(&event->active_list, get_event_list(event));
 	}
 
-	/*
-	 * If this pinned group hasn't been scheduled,
-	 * put it in error state.
-	 */
-	if (event->state == PERF_EVENT_STATE_INACTIVE)
-		perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
-
-	return 0;
-}
-
-static int flexible_sched_in(struct perf_event *event, void *data)
-{
-	struct sched_in_data *sid = data;
-
-	if (event->state <= PERF_EVENT_STATE_OFF)
-		return 0;
-
-	if (!event_filter_match(event))
-		return 0;
-
-	if (group_can_go_on(event, sid->cpuctx, sid->can_add_hw)) {
-		int ret = group_sched_in(event, sid->cpuctx, sid->ctx);
-		if (ret) {
-			sid->can_add_hw = 0;
-			sid->ctx->rotate_necessary = 1;
-			return 0;
+	if (event->state == PERF_EVENT_STATE_INACTIVE) {
+		*can_add_hw = 0;
+		if (event->attr.pinned) {
+			perf_cgroup_event_disable(event, ctx);
+			perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
+		} else {
+			ctx->rotate_necessary = 1;
+			perf_mux_hrtimer_restart(cpuctx);
+			group_update_userpage(event);
 		}
-		list_add_tail(&event->active_list, &sid->ctx->flexible_active);
 	}
 
 	return 0;
@@ -3439,30 +3780,28 @@
 ctx_pinned_sched_in(struct perf_event_context *ctx,
 		    struct perf_cpu_context *cpuctx)
 {
-	struct sched_in_data sid = {
-		.ctx = ctx,
-		.cpuctx = cpuctx,
-		.can_add_hw = 1,
-	};
+	int can_add_hw = 1;
 
-	visit_groups_merge(&ctx->pinned_groups,
+	if (ctx != &cpuctx->ctx)
+		cpuctx = NULL;
+
+	visit_groups_merge(cpuctx, &ctx->pinned_groups,
 			   smp_processor_id(),
-			   pinned_sched_in, &sid);
+			   merge_sched_in, &can_add_hw);
 }
 
 static void
 ctx_flexible_sched_in(struct perf_event_context *ctx,
 		      struct perf_cpu_context *cpuctx)
 {
-	struct sched_in_data sid = {
-		.ctx = ctx,
-		.cpuctx = cpuctx,
-		.can_add_hw = 1,
-	};
+	int can_add_hw = 1;
 
-	visit_groups_merge(&ctx->flexible_groups,
+	if (ctx != &cpuctx->ctx)
+		cpuctx = NULL;
+
+	visit_groups_merge(cpuctx, &ctx->flexible_groups,
 			   smp_processor_id(),
-			   flexible_sched_in, &sid);
+			   merge_sched_in, &can_add_hw);
 }
 
 static void
@@ -3472,13 +3811,23 @@
 	     struct task_struct *task)
 {
 	int is_active = ctx->is_active;
-	u64 now;
 
 	lockdep_assert_held(&ctx->lock);
 
 	if (likely(!ctx->nr_events))
 		return;
 
+	if (is_active ^ EVENT_TIME) {
+		/* start ctx time */
+		__update_context_time(ctx, false);
+		perf_cgroup_set_timestamp(task, ctx);
+		/*
+		 * CPU-release for the below ->is_active store,
+		 * see __load_acquire() in perf_event_time_now()
+		 */
+		barrier();
+	}
+
 	ctx->is_active |= (event_type | EVENT_TIME);
 	if (ctx->task) {
 		if (!is_active)
@@ -3489,13 +3838,6 @@
 
 	is_active ^= ctx->is_active; /* changed bits */
 
-	if (is_active & EVENT_TIME) {
-		/* start ctx time */
-		now = perf_clock();
-		ctx->timestamp = now;
-		perf_cgroup_set_timestamp(task, ctx);
-	}
-
 	/*
 	 * First go through the list and put on any pinned groups
 	 * in order to give them the best chance of going on.
@@ -3521,10 +3863,14 @@
 					struct task_struct *task)
 {
 	struct perf_cpu_context *cpuctx;
+	struct pmu *pmu = ctx->pmu;
 
 	cpuctx = __get_cpu_context(ctx);
-	if (cpuctx->task_ctx == ctx)
+	if (cpuctx->task_ctx == ctx) {
+		if (cpuctx->sched_cb_usage)
+			__perf_pmu_sched_task(cpuctx, true);
 		return;
+	}
 
 	perf_ctx_lock(cpuctx, ctx);
 	/*
@@ -3534,7 +3880,7 @@
 	if (!ctx->nr_events)
 		goto unlock;
 
-	perf_pmu_disable(ctx->pmu);
+	perf_pmu_disable(pmu);
 	/*
 	 * We want to keep the following priority order:
 	 * cpu pinned (that don't need to move), task pinned,
@@ -3546,7 +3892,11 @@
 	if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree))
 		cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
 	perf_event_sched_in(cpuctx, ctx, task);
-	perf_pmu_enable(ctx->pmu);
+
+	if (cpuctx->sched_cb_usage && pmu->sched_task)
+		pmu->sched_task(cpuctx->task_ctx, true);
+
+	perf_pmu_enable(pmu);
 
 unlock:
 	perf_ctx_unlock(cpuctx, ctx);
@@ -4023,6 +4373,18 @@
 	return local64_read(&event->count) + atomic64_read(&event->child_count);
 }
 
+static void calc_timer_values(struct perf_event *event,
+				u64 *now,
+				u64 *enabled,
+				u64 *running)
+{
+	u64 ctx_time;
+
+	*now = perf_clock();
+	ctx_time = perf_event_time_now(event, *now);
+	__perf_update_times(event, ctx_time, enabled, running);
+}
+
 /*
  * NMI-safe method to read a local event, that is an event that
  * is:
@@ -4082,10 +4444,9 @@
 
 	*value = local64_read(&event->count);
 	if (enabled || running) {
-		u64 now = event->shadow_ctx_time + perf_clock();
-		u64 __enabled, __running;
+		u64 __enabled, __running, __now;;
 
-		__perf_update_times(event, now, &__enabled, &__running);
+		calc_timer_values(event, &__now, &__enabled, &__running);
 		if (enabled)
 			*enabled = __enabled;
 		if (running)
@@ -4243,8 +4604,9 @@
 
 	if (!task) {
 		/* Must be root to operate on a CPU event: */
-		if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
-			return ERR_PTR(-EACCES);
+		err = perf_allow_cpu(&event->attr);
+		if (err)
+			return ERR_PTR(err);
 
 		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
 		ctx = &cpuctx->ctx;
@@ -4262,7 +4624,7 @@
 		goto errout;
 
 	if (event->attach_state & PERF_ATTACH_TASK_DATA) {
-		task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL);
+		task_ctx_data = alloc_task_ctx_data(pmu);
 		if (!task_ctx_data) {
 			err = -ENOMEM;
 			goto errout;
@@ -4320,11 +4682,11 @@
 		}
 	}
 
-	kfree(task_ctx_data);
+	free_task_ctx_data(pmu, task_ctx_data);
 	return ctx;
 
 errout:
-	kfree(task_ctx_data);
+	free_task_ctx_data(pmu, task_ctx_data);
 	return ERR_PTR(err);
 }
 
@@ -4343,7 +4705,7 @@
 }
 
 static void ring_buffer_attach(struct perf_event *event,
-			       struct ring_buffer *rb);
+			       struct perf_buffer *rb);
 
 static void detach_sb_event(struct perf_event *event)
 {
@@ -4367,7 +4729,7 @@
 	if (attr->mmap || attr->mmap_data || attr->mmap2 ||
 	    attr->comm || attr->comm_exec ||
 	    attr->task || attr->ksymbol ||
-	    attr->context_switch ||
+	    attr->context_switch || attr->text_poke ||
 	    attr->bpf_event)
 		return true;
 	return false;
@@ -4417,7 +4779,7 @@
 	if (event->parent)
 		return;
 
-	if (event->attach_state & PERF_ATTACH_TASK)
+	if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB))
 		dec = true;
 	if (event->attr.mmap || event->attr.mmap_data)
 		atomic_dec(&nr_mmap_events);
@@ -4425,6 +4787,8 @@
 		atomic_dec(&nr_comm_events);
 	if (event->attr.namespaces)
 		atomic_dec(&nr_namespaces_events);
+	if (event->attr.cgroup)
+		atomic_dec(&nr_cgroup_events);
 	if (event->attr.task)
 		atomic_dec(&nr_task_events);
 	if (event->attr.freq)
@@ -4441,6 +4805,8 @@
 		atomic_dec(&nr_ksymbol_events);
 	if (event->attr.bpf_event)
 		atomic_dec(&nr_bpf_events);
+	if (event->attr.text_poke)
+		atomic_dec(&nr_text_poke_events);
 
 	if (dec) {
 		if (!atomic_add_unless(&perf_sched_count, -1, 1))
@@ -4555,6 +4921,8 @@
 
 	unaccount_event(event);
 
+	security_perf_event_free(event);
+
 	if (event->rb) {
 		/*
 		 * Can happen when we close an event with re-directed output.
@@ -5008,6 +5376,10 @@
 	struct perf_event_context *ctx;
 	int ret;
 
+	ret = security_perf_event_read(event);
+	if (ret)
+		return ret;
+
 	ctx = perf_event_ctx_lock(event);
 	ret = __perf_read(event, buf, count);
 	perf_event_ctx_unlock(event, ctx);
@@ -5018,7 +5390,7 @@
 static __poll_t perf_poll(struct file *file, poll_table *wait)
 {
 	struct perf_event *event = file->private_data;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	__poll_t events = EPOLLHUP;
 
 	poll_wait(file, &event->waitq, wait);
@@ -5045,6 +5417,24 @@
 	perf_event_update_userpage(event);
 }
 
+/* Assume it's not an event with inherit set. */
+u64 perf_event_pause(struct perf_event *event, bool reset)
+{
+	struct perf_event_context *ctx;
+	u64 count;
+
+	ctx = perf_event_ctx_lock(event);
+	WARN_ON_ONCE(event->attr.inherit);
+	_perf_event_disable(event);
+	count = local64_read(&event->count);
+	if (reset)
+		local64_set(&event->count, 0);
+	perf_event_ctx_unlock(event, ctx);
+
+	return count;
+}
+EXPORT_SYMBOL_GPL(perf_event_pause);
+
 /*
  * Holding the top-level event's child_mutex means that any
  * descendant process that has inherited this event will block
@@ -5122,16 +5512,11 @@
 	return event->pmu->check_period(event, value);
 }
 
-static int perf_event_period(struct perf_event *event, u64 __user *arg)
+static int _perf_event_period(struct perf_event *event, u64 value)
 {
-	u64 value;
-
 	if (!is_sampling_event(event))
 		return -EINVAL;
 
-	if (copy_from_user(&value, arg, sizeof(value)))
-		return -EFAULT;
-
 	if (!value)
 		return -EINVAL;
 
@@ -5149,6 +5534,19 @@
 	return 0;
 }
 
+int perf_event_period(struct perf_event *event, u64 value)
+{
+	struct perf_event_context *ctx;
+	int ret;
+
+	ctx = perf_event_ctx_lock(event);
+	ret = _perf_event_period(event, value);
+	perf_event_ctx_unlock(event, ctx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(perf_event_period);
+
 static const struct file_operations perf_fops;
 
 static inline int perf_fget_light(int fd, struct fd *p)
@@ -5192,8 +5590,14 @@
 		return _perf_event_refresh(event, arg);
 
 	case PERF_EVENT_IOC_PERIOD:
-		return perf_event_period(event, (u64 __user *)arg);
+	{
+		u64 value;
 
+		if (copy_from_user(&value, (u64 __user *)arg, sizeof(value)))
+			return -EFAULT;
+
+		return _perf_event_period(event, value);
+	}
 	case PERF_EVENT_IOC_ID:
 	{
 		u64 id = primary_event_id(event);
@@ -5228,7 +5632,7 @@
 		return perf_event_set_bpf_prog(event, arg);
 
 	case PERF_EVENT_IOC_PAUSE_OUTPUT: {
-		struct ring_buffer *rb;
+		struct perf_buffer *rb;
 
 		rcu_read_lock();
 		rb = rcu_dereference(event->rb);
@@ -5272,6 +5676,11 @@
 	struct perf_event_context *ctx;
 	long ret;
 
+	/* Treat ioctl like writes as it is likely a mutating operation. */
+	ret = security_perf_event_write(event);
+	if (ret)
+		return ret;
+
 	ctx = perf_event_ctx_lock(event);
 	ret = _perf_ioctl(event, cmd, arg);
 	perf_event_ctx_unlock(event, ctx);
@@ -5344,22 +5753,10 @@
 	return event->pmu->event_idx(event);
 }
 
-static void calc_timer_values(struct perf_event *event,
-				u64 *now,
-				u64 *enabled,
-				u64 *running)
-{
-	u64 ctx_time;
-
-	*now = perf_clock();
-	ctx_time = event->shadow_ctx_time + *now;
-	__perf_update_times(event, ctx_time, enabled, running);
-}
-
 static void perf_event_init_userpage(struct perf_event *event)
 {
 	struct perf_event_mmap_page *userpg;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5391,7 +5788,7 @@
 void perf_event_update_userpage(struct perf_event *event)
 {
 	struct perf_event_mmap_page *userpg;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	u64 enabled, running, now;
 
 	rcu_read_lock();
@@ -5442,7 +5839,7 @@
 static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
 {
 	struct perf_event *event = vmf->vma->vm_file->private_data;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	vm_fault_t ret = VM_FAULT_SIGBUS;
 
 	if (vmf->flags & FAULT_FLAG_MKWRITE) {
@@ -5475,11 +5872,13 @@
 }
 
 static void ring_buffer_attach(struct perf_event *event,
-			       struct ring_buffer *rb)
+			       struct perf_buffer *rb)
 {
-	struct ring_buffer *old_rb = NULL;
+	struct perf_buffer *old_rb = NULL;
 	unsigned long flags;
 
+	WARN_ON_ONCE(event->parent);
+
 	if (event->rb) {
 		/*
 		 * Should be impossible, we set this when removing
@@ -5535,7 +5934,10 @@
 
 static void ring_buffer_wakeup(struct perf_event *event)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
+
+	if (event->parent)
+		event = event->parent;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5546,9 +5948,12 @@
 	rcu_read_unlock();
 }
 
-struct ring_buffer *ring_buffer_get(struct perf_event *event)
+struct perf_buffer *ring_buffer_get(struct perf_event *event)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
+
+	if (event->parent)
+		event = event->parent;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5561,7 +5966,7 @@
 	return rb;
 }
 
-void ring_buffer_put(struct ring_buffer *rb)
+void ring_buffer_put(struct perf_buffer *rb)
 {
 	if (!refcount_dec_and_test(&rb->refcount))
 		return;
@@ -5598,7 +6003,7 @@
 static void perf_mmap_close(struct vm_area_struct *vma)
 {
 	struct perf_event *event = vma->vm_file->private_data;
-	struct ring_buffer *rb = ring_buffer_get(event);
+	struct perf_buffer *rb = ring_buffer_get(event);
 	struct user_struct *mmap_user = rb->mmap_user;
 	int mmap_locked = rb->mmap_locked;
 	unsigned long size = perf_data_size(rb);
@@ -5718,8 +6123,8 @@
 	struct perf_event *event = file->private_data;
 	unsigned long user_locked, user_lock_limit;
 	struct user_struct *user = current_user();
+	struct perf_buffer *rb = NULL;
 	unsigned long locked, lock_limit;
-	struct ring_buffer *rb = NULL;
 	unsigned long vma_size;
 	unsigned long nr_pages;
 	long user_extra = 0, extra = 0;
@@ -5736,6 +6141,10 @@
 	if (!(vma->vm_flags & VM_SHARED))
 		return -EINVAL;
 
+	ret = security_perf_event_read(event);
+	if (ret)
+		return ret;
+
 	vma_size = vma->vm_end - vma->vm_start;
 
 	if (vma->vm_pgoff == 0) {
@@ -5850,13 +6259,7 @@
 		user_locked = user_lock_limit;
 	user_locked += user_extra;
 
-	if (user_locked <= user_lock_limit) {
-		/* charge all to locked_vm */
-	} else if (atomic_long_read(&user->locked_vm) >= user_lock_limit) {
-		/* charge all to pinned_vm */
-		extra = user_extra;
-		user_extra = 0;
-	} else {
+	if (user_locked > user_lock_limit) {
 		/*
 		 * charge locked_vm until it hits user_lock_limit;
 		 * charge the rest from pinned_vm
@@ -5869,7 +6272,7 @@
 	lock_limit >>= PAGE_SHIFT;
 	locked = atomic64_read(&vma->vm_mm->pinned_vm) + extra;
 
-	if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
+	if ((locked > lock_limit) && perf_is_paranoid() &&
 		!capable(CAP_IPC_LOCK)) {
 		ret = -EPERM;
 		goto unlock;
@@ -5896,6 +6299,7 @@
 
 		ring_buffer_attach(event, rb);
 
+		perf_event_update_time(event);
 		perf_event_init_userpage(event);
 		perf_event_update_userpage(event);
 	} else {
@@ -6045,18 +6449,25 @@
  * Later on, we might change it to a list if there is
  * another virtualization implementation supporting the callbacks.
  */
-struct perf_guest_info_callbacks *perf_guest_cbs;
+struct perf_guest_info_callbacks __rcu *perf_guest_cbs;
 
 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
 {
-	perf_guest_cbs = cbs;
+	if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs)))
+		return -EBUSY;
+
+	rcu_assign_pointer(perf_guest_cbs, cbs);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
 
 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
 {
-	perf_guest_cbs = NULL;
+	if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs) != cbs))
+		return -EINVAL;
+
+	rcu_assign_pointer(perf_guest_cbs, NULL);
+	synchronize_rcu();
 	return 0;
 }
 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
@@ -6078,14 +6489,13 @@
 }
 
 static void perf_sample_regs_user(struct perf_regs *regs_user,
-				  struct pt_regs *regs,
-				  struct pt_regs *regs_user_copy)
+				  struct pt_regs *regs)
 {
 	if (user_mode(regs)) {
 		regs_user->abi = perf_reg_abi(current);
 		regs_user->regs = regs;
 	} else if (!(current->flags & PF_KTHREAD)) {
-		perf_get_regs_user(regs_user, regs, regs_user_copy);
+		perf_get_regs_user(regs_user, regs);
 	} else {
 		regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
 		regs_user->regs = NULL;
@@ -6186,10 +6596,9 @@
 
 		/* Data. */
 		sp = perf_user_stack_pointer(regs);
-		fs = get_fs();
-		set_fs(USER_DS);
+		fs = force_uaccess_begin();
 		rem = __output_copy_user(handle, (void *) sp, dump_size);
-		set_fs(fs);
+		force_uaccess_end(fs);
 		dyn_size = dump_size - rem;
 
 		perf_output_skip(handle, rem);
@@ -6199,6 +6608,122 @@
 	}
 }
 
+static unsigned long perf_prepare_sample_aux(struct perf_event *event,
+					  struct perf_sample_data *data,
+					  size_t size)
+{
+	struct perf_event *sampler = event->aux_event;
+	struct perf_buffer *rb;
+
+	data->aux_size = 0;
+
+	if (!sampler)
+		goto out;
+
+	if (WARN_ON_ONCE(READ_ONCE(sampler->state) != PERF_EVENT_STATE_ACTIVE))
+		goto out;
+
+	if (WARN_ON_ONCE(READ_ONCE(sampler->oncpu) != smp_processor_id()))
+		goto out;
+
+	rb = ring_buffer_get(sampler);
+	if (!rb)
+		goto out;
+
+	/*
+	 * If this is an NMI hit inside sampling code, don't take
+	 * the sample. See also perf_aux_sample_output().
+	 */
+	if (READ_ONCE(rb->aux_in_sampling)) {
+		data->aux_size = 0;
+	} else {
+		size = min_t(size_t, size, perf_aux_size(rb));
+		data->aux_size = ALIGN(size, sizeof(u64));
+	}
+	ring_buffer_put(rb);
+
+out:
+	return data->aux_size;
+}
+
+long perf_pmu_snapshot_aux(struct perf_buffer *rb,
+			   struct perf_event *event,
+			   struct perf_output_handle *handle,
+			   unsigned long size)
+{
+	unsigned long flags;
+	long ret;
+
+	/*
+	 * Normal ->start()/->stop() callbacks run in IRQ mode in scheduler
+	 * paths. If we start calling them in NMI context, they may race with
+	 * the IRQ ones, that is, for example, re-starting an event that's just
+	 * been stopped, which is why we're using a separate callback that
+	 * doesn't change the event state.
+	 *
+	 * IRQs need to be disabled to prevent IPIs from racing with us.
+	 */
+	local_irq_save(flags);
+	/*
+	 * Guard against NMI hits inside the critical section;
+	 * see also perf_prepare_sample_aux().
+	 */
+	WRITE_ONCE(rb->aux_in_sampling, 1);
+	barrier();
+
+	ret = event->pmu->snapshot_aux(event, handle, size);
+
+	barrier();
+	WRITE_ONCE(rb->aux_in_sampling, 0);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+static void perf_aux_sample_output(struct perf_event *event,
+				   struct perf_output_handle *handle,
+				   struct perf_sample_data *data)
+{
+	struct perf_event *sampler = event->aux_event;
+	struct perf_buffer *rb;
+	unsigned long pad;
+	long size;
+
+	if (WARN_ON_ONCE(!sampler || !data->aux_size))
+		return;
+
+	rb = ring_buffer_get(sampler);
+	if (!rb)
+		return;
+
+	size = perf_pmu_snapshot_aux(rb, sampler, handle, data->aux_size);
+
+	/*
+	 * An error here means that perf_output_copy() failed (returned a
+	 * non-zero surplus that it didn't copy), which in its current
+	 * enlightened implementation is not possible. If that changes, we'd
+	 * like to know.
+	 */
+	if (WARN_ON_ONCE(size < 0))
+		goto out_put;
+
+	/*
+	 * The pad comes from ALIGN()ing data->aux_size up to u64 in
+	 * perf_prepare_sample_aux(), so should not be more than that.
+	 */
+	pad = data->aux_size - size;
+	if (WARN_ON_ONCE(pad >= sizeof(u64)))
+		pad = 8;
+
+	if (pad) {
+		u64 zero = 0;
+		perf_output_copy(handle, &zero, pad);
+	}
+
+out_put:
+	ring_buffer_put(rb);
+}
+
 static void __perf_event_header__init_id(struct perf_event_header *header,
 					 struct perf_sample_data *data,
 					 struct perf_event *event)
@@ -6368,6 +6893,11 @@
 		perf_output_read_one(handle, event, enabled, running);
 }
 
+static inline bool perf_sample_save_hw_index(struct perf_event *event)
+{
+	return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX;
+}
+
 void perf_output_sample(struct perf_output_handle *handle,
 			struct perf_event_header *header,
 			struct perf_sample_data *data,
@@ -6456,6 +6986,8 @@
 			     * sizeof(struct perf_branch_entry);
 
 			perf_output_put(handle, data->br_stack->nr);
+			if (perf_sample_save_hw_index(event))
+				perf_output_put(handle, data->br_stack->hw_idx);
 			perf_output_copy(handle, data->br_stack->entries, size);
 		} else {
 			/*
@@ -6518,11 +7050,21 @@
 	if (sample_type & PERF_SAMPLE_PHYS_ADDR)
 		perf_output_put(handle, data->phys_addr);
 
+	if (sample_type & PERF_SAMPLE_CGROUP)
+		perf_output_put(handle, data->cgroup);
+
+	if (sample_type & PERF_SAMPLE_AUX) {
+		perf_output_put(handle, data->aux_size);
+
+		if (data->aux_size)
+			perf_aux_sample_output(event, handle, data);
+	}
+
 	if (!event->attr.watermark) {
 		int wakeup_events = event->attr.wakeup_events;
 
 		if (wakeup_events) {
-			struct ring_buffer *rb = handle->rb;
+			struct perf_buffer *rb = handle->rb;
 			int events = local_inc_return(&rb->events);
 
 			if (events >= wakeup_events) {
@@ -6536,7 +7078,6 @@
 static u64 perf_virt_to_phys(u64 virt)
 {
 	u64 phys_addr = 0;
-	struct page *p = NULL;
 
 	if (!virt)
 		return 0;
@@ -6551,18 +7092,19 @@
 		 * Walking the pages tables for user address.
 		 * Interrupts are disabled, so it prevents any tear down
 		 * of the page tables.
-		 * Try IRQ-safe __get_user_pages_fast first.
+		 * Try IRQ-safe get_user_page_fast_only first.
 		 * If failed, leave phys_addr as 0.
 		 */
 		if (current->mm != NULL) {
+			struct page *p;
+
 			pagefault_disable();
-			if (__get_user_pages_fast(virt, 1, 0, &p) == 1)
+			if (get_user_page_fast_only(virt, 0, &p)) {
 				phys_addr = page_to_phys(p) + virt % PAGE_SIZE;
+				put_page(p);
+			}
 			pagefault_enable();
 		}
-
-		if (p)
-			put_page(p);
 	}
 
 	return phys_addr;
@@ -6645,6 +7187,9 @@
 	if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
 		int size = sizeof(u64); /* nr */
 		if (data->br_stack) {
+			if (perf_sample_save_hw_index(event))
+				size += sizeof(u64);
+
 			size += data->br_stack->nr
 			      * sizeof(struct perf_branch_entry);
 		}
@@ -6652,8 +7197,7 @@
 	}
 
 	if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
-		perf_sample_regs_user(&data->regs_user, regs,
-				      &data->regs_user_copy);
+		perf_sample_regs_user(&data->regs_user, regs);
 
 	if (sample_type & PERF_SAMPLE_REGS_USER) {
 		/* regs dump ABI info */
@@ -6709,6 +7253,45 @@
 
 	if (sample_type & PERF_SAMPLE_PHYS_ADDR)
 		data->phys_addr = perf_virt_to_phys(data->addr);
+
+#ifdef CONFIG_CGROUP_PERF
+	if (sample_type & PERF_SAMPLE_CGROUP) {
+		struct cgroup *cgrp;
+
+		/* protected by RCU */
+		cgrp = task_css_check(current, perf_event_cgrp_id, 1)->cgroup;
+		data->cgroup = cgroup_id(cgrp);
+	}
+#endif
+
+	if (sample_type & PERF_SAMPLE_AUX) {
+		u64 size;
+
+		header->size += sizeof(u64); /* size */
+
+		/*
+		 * Given the 16bit nature of header::size, an AUX sample can
+		 * easily overflow it, what with all the preceding sample bits.
+		 * Make sure this doesn't happen by using up to U16_MAX bytes
+		 * per sample in total (rounded down to 8 byte boundary).
+		 */
+		size = min_t(size_t, U16_MAX - header->size,
+			     event->attr.aux_sample_size);
+		size = rounddown(size, 8);
+		size = perf_prepare_sample_aux(event, data, size);
+
+		WARN_ON_ONCE(size + header->size > U16_MAX);
+		header->size += size;
+	}
+	/*
+	 * If you're adding more sample types here, you likely need to do
+	 * something about the overflowing header::size, like repurpose the
+	 * lowest 3 bits of size, which should be always zero at the moment.
+	 * This raises a more important question, do we really need 512k sized
+	 * samples and why, so good argumentation is in order for whatever you
+	 * do here next.
+	 */
+	WARN_ON_ONCE(header->size & 7);
 }
 
 static __always_inline int
@@ -6716,6 +7299,7 @@
 		    struct perf_sample_data *data,
 		    struct pt_regs *regs,
 		    int (*output_begin)(struct perf_output_handle *,
+					struct perf_sample_data *,
 					struct perf_event *,
 					unsigned int))
 {
@@ -6728,7 +7312,7 @@
 
 	perf_prepare_sample(&header, data, event, regs);
 
-	err = output_begin(&handle, event, header.size);
+	err = output_begin(&handle, data, event, header.size);
 	if (err)
 		goto exit;
 
@@ -6794,7 +7378,7 @@
 	int ret;
 
 	perf_event_header__init_id(&read_event.header, &sample, event);
-	ret = perf_output_begin(&handle, event, read_event.header.size);
+	ret = perf_output_begin(&handle, &sample, event, read_event.header.size);
 	if (ret)
 		return;
 
@@ -6939,7 +7523,7 @@
 }
 
 struct remote_output {
-	struct ring_buffer	*rb;
+	struct perf_buffer	*rb;
 	int			err;
 };
 
@@ -6947,7 +7531,7 @@
 {
 	struct perf_event *parent = event->parent;
 	struct remote_output *ro = data;
-	struct ring_buffer *rb = ro->rb;
+	struct perf_buffer *rb = ro->rb;
 	struct stop_event_data sd = {
 		.event	= event,
 	};
@@ -7063,7 +7647,7 @@
 
 	perf_event_header__init_id(&task_event->event_id.header, &sample, event);
 
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				task_event->event_id.header.size);
 	if (ret)
 		goto out;
@@ -7166,7 +7750,7 @@
 		return;
 
 	perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				comm_event->event_id.header.size);
 
 	if (ret)
@@ -7266,7 +7850,7 @@
 
 	perf_event_header__init_id(&namespaces_event->event_id.header,
 				   &sample, event);
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				namespaces_event->event_id.header.size);
 	if (ret)
 		goto out;
@@ -7291,7 +7875,7 @@
 {
 	struct path ns_path;
 	struct inode *ns_inode;
-	void *error;
+	int error;
 
 	error = ns_get_path(&ns_path, task, ns_ops);
 	if (!error) {
@@ -7361,6 +7945,105 @@
 }
 
 /*
+ * cgroup tracking
+ */
+#ifdef CONFIG_CGROUP_PERF
+
+struct perf_cgroup_event {
+	char				*path;
+	int				path_size;
+	struct {
+		struct perf_event_header	header;
+		u64				id;
+		char				path[];
+	} event_id;
+};
+
+static int perf_event_cgroup_match(struct perf_event *event)
+{
+	return event->attr.cgroup;
+}
+
+static void perf_event_cgroup_output(struct perf_event *event, void *data)
+{
+	struct perf_cgroup_event *cgroup_event = data;
+	struct perf_output_handle handle;
+	struct perf_sample_data sample;
+	u16 header_size = cgroup_event->event_id.header.size;
+	int ret;
+
+	if (!perf_event_cgroup_match(event))
+		return;
+
+	perf_event_header__init_id(&cgroup_event->event_id.header,
+				   &sample, event);
+	ret = perf_output_begin(&handle, &sample, event,
+				cgroup_event->event_id.header.size);
+	if (ret)
+		goto out;
+
+	perf_output_put(&handle, cgroup_event->event_id);
+	__output_copy(&handle, cgroup_event->path, cgroup_event->path_size);
+
+	perf_event__output_id_sample(event, &handle, &sample);
+
+	perf_output_end(&handle);
+out:
+	cgroup_event->event_id.header.size = header_size;
+}
+
+static void perf_event_cgroup(struct cgroup *cgrp)
+{
+	struct perf_cgroup_event cgroup_event;
+	char path_enomem[16] = "//enomem";
+	char *pathname;
+	size_t size;
+
+	if (!atomic_read(&nr_cgroup_events))
+		return;
+
+	cgroup_event = (struct perf_cgroup_event){
+		.event_id  = {
+			.header = {
+				.type = PERF_RECORD_CGROUP,
+				.misc = 0,
+				.size = sizeof(cgroup_event.event_id),
+			},
+			.id = cgroup_id(cgrp),
+		},
+	};
+
+	pathname = kmalloc(PATH_MAX, GFP_KERNEL);
+	if (pathname == NULL) {
+		cgroup_event.path = path_enomem;
+	} else {
+		/* just to be sure to have enough space for alignment */
+		cgroup_path(cgrp, pathname, PATH_MAX - sizeof(u64));
+		cgroup_event.path = pathname;
+	}
+
+	/*
+	 * Since our buffer works in 8 byte units we need to align our string
+	 * size to a multiple of 8. However, we must guarantee the tail end is
+	 * zero'd out to avoid leaking random bits to userspace.
+	 */
+	size = strlen(cgroup_event.path) + 1;
+	while (!IS_ALIGNED(size, sizeof(u64)))
+		cgroup_event.path[size++] = '\0';
+
+	cgroup_event.event_id.header.size += size;
+	cgroup_event.path_size = size;
+
+	perf_iterate_sb(perf_event_cgroup_output,
+			&cgroup_event,
+			NULL);
+
+	kfree(pathname);
+}
+
+#endif
+
+/*
  * mmap tracking
  */
 
@@ -7420,7 +8103,7 @@
 	}
 
 	perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				mmap_event->event_id.header.size);
 	if (ret)
 		goto out;
@@ -7480,7 +8163,7 @@
 		flags |= MAP_EXECUTABLE;
 	if (vma->vm_flags & VM_LOCKED)
 		flags |= MAP_LOCKED;
-	if (vma->vm_flags & VM_HUGETLB)
+	if (is_vm_hugetlb_page(vma))
 		flags |= MAP_HUGETLB;
 
 	if (file) {
@@ -7730,7 +8413,7 @@
 	int ret;
 
 	perf_event_header__init_id(&rec.header, &sample, event);
-	ret = perf_output_begin(&handle, event, rec.header.size);
+	ret = perf_output_begin(&handle, &sample, event, rec.header.size);
 
 	if (ret)
 		return;
@@ -7764,7 +8447,7 @@
 
 	perf_event_header__init_id(&lost_samples_event.header, &sample, event);
 
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				lost_samples_event.header.size);
 	if (ret)
 		return;
@@ -7819,7 +8502,7 @@
 
 	perf_event_header__init_id(&se->event_id.header, &sample, event);
 
-	ret = perf_output_begin(&handle, event, se->event_id.header.size);
+	ret = perf_output_begin(&handle, &sample, event, se->event_id.header.size);
 	if (ret)
 		return;
 
@@ -7894,7 +8577,7 @@
 
 	perf_event_header__init_id(&throttle_event.header, &sample, event);
 
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				throttle_event.header.size);
 	if (ret)
 		return;
@@ -7937,7 +8620,7 @@
 
 	perf_event_header__init_id(&ksymbol_event->event_id.header,
 				   &sample, event);
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, &sample, event,
 				ksymbol_event->event_id.header.size);
 	if (ret)
 		return;
@@ -8027,7 +8710,7 @@
 
 	perf_event_header__init_id(&bpf_event->event_id.header,
 				   &sample, event);
-	ret = perf_output_begin(&handle, event,
+	ret = perf_output_begin(&handle, data, event,
 				bpf_event->event_id.header.size);
 	if (ret)
 		return;
@@ -8042,23 +8725,22 @@
 					 enum perf_bpf_event_type type)
 {
 	bool unregister = type == PERF_BPF_EVENT_PROG_UNLOAD;
-	char sym[KSYM_NAME_LEN];
 	int i;
 
 	if (prog->aux->func_cnt == 0) {
-		bpf_get_prog_name(prog, sym);
 		perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF,
 				   (u64)(unsigned long)prog->bpf_func,
-				   prog->jited_len, unregister, sym);
+				   prog->jited_len, unregister,
+				   prog->aux->ksym.name);
 	} else {
 		for (i = 0; i < prog->aux->func_cnt; i++) {
 			struct bpf_prog *subprog = prog->aux->func[i];
 
-			bpf_get_prog_name(subprog, sym);
 			perf_event_ksymbol(
 				PERF_RECORD_KSYMBOL_TYPE_BPF,
 				(u64)(unsigned long)subprog->bpf_func,
-				subprog->jited_len, unregister, sym);
+				subprog->jited_len, unregister,
+				prog->aux->ksym.name);
 		}
 	}
 }
@@ -8105,6 +8787,90 @@
 	perf_iterate_sb(perf_event_bpf_output, &bpf_event, NULL);
 }
 
+struct perf_text_poke_event {
+	const void		*old_bytes;
+	const void		*new_bytes;
+	size_t			pad;
+	u16			old_len;
+	u16			new_len;
+
+	struct {
+		struct perf_event_header	header;
+
+		u64				addr;
+	} event_id;
+};
+
+static int perf_event_text_poke_match(struct perf_event *event)
+{
+	return event->attr.text_poke;
+}
+
+static void perf_event_text_poke_output(struct perf_event *event, void *data)
+{
+	struct perf_text_poke_event *text_poke_event = data;
+	struct perf_output_handle handle;
+	struct perf_sample_data sample;
+	u64 padding = 0;
+	int ret;
+
+	if (!perf_event_text_poke_match(event))
+		return;
+
+	perf_event_header__init_id(&text_poke_event->event_id.header, &sample, event);
+
+	ret = perf_output_begin(&handle, &sample, event,
+				text_poke_event->event_id.header.size);
+	if (ret)
+		return;
+
+	perf_output_put(&handle, text_poke_event->event_id);
+	perf_output_put(&handle, text_poke_event->old_len);
+	perf_output_put(&handle, text_poke_event->new_len);
+
+	__output_copy(&handle, text_poke_event->old_bytes, text_poke_event->old_len);
+	__output_copy(&handle, text_poke_event->new_bytes, text_poke_event->new_len);
+
+	if (text_poke_event->pad)
+		__output_copy(&handle, &padding, text_poke_event->pad);
+
+	perf_event__output_id_sample(event, &handle, &sample);
+
+	perf_output_end(&handle);
+}
+
+void perf_event_text_poke(const void *addr, const void *old_bytes,
+			  size_t old_len, const void *new_bytes, size_t new_len)
+{
+	struct perf_text_poke_event text_poke_event;
+	size_t tot, pad;
+
+	if (!atomic_read(&nr_text_poke_events))
+		return;
+
+	tot  = sizeof(text_poke_event.old_len) + old_len;
+	tot += sizeof(text_poke_event.new_len) + new_len;
+	pad  = ALIGN(tot, sizeof(u64)) - tot;
+
+	text_poke_event = (struct perf_text_poke_event){
+		.old_bytes    = old_bytes,
+		.new_bytes    = new_bytes,
+		.pad          = pad,
+		.old_len      = old_len,
+		.new_len      = new_len,
+		.event_id  = {
+			.header = {
+				.type = PERF_RECORD_TEXT_POKE,
+				.misc = PERF_RECORD_MISC_KERNEL,
+				.size = sizeof(text_poke_event.event_id) + tot + pad,
+			},
+			.addr = (unsigned long)addr,
+		},
+	};
+
+	perf_iterate_sb(perf_event_text_poke_output, &text_poke_event, NULL);
+}
+
 void perf_event_itrace_started(struct perf_event *event)
 {
 	event->attach_state |= PERF_ATTACH_ITRACE;
@@ -8135,7 +8901,7 @@
 	rec.tid	= perf_event_tid(event, current);
 
 	perf_event_header__init_id(&rec.header, &sample, event);
-	ret = perf_output_begin(&handle, event, rec.header.size);
+	ret = perf_output_begin(&handle, &sample, event, rec.header.size);
 
 	if (ret)
 		return;
@@ -8884,7 +9650,7 @@
 	if (event->attr.type != perf_kprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
@@ -8944,7 +9710,7 @@
 	if (event->attr.type != perf_uprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
@@ -8993,7 +9759,6 @@
 	int ret = 0;
 
 	ctx.regs = perf_arch_bpf_user_pt_regs(regs);
-	preempt_disable();
 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
 		goto out;
 	rcu_read_lock();
@@ -9001,7 +9766,6 @@
 	rcu_read_unlock();
 out:
 	__this_cpu_dec(bpf_prog_active);
-	preempt_enable();
 	if (!ret)
 		return;
 
@@ -9023,6 +9787,24 @@
 	if (IS_ERR(prog))
 		return PTR_ERR(prog);
 
+	if (event->attr.precise_ip &&
+	    prog->call_get_stack &&
+	    (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY) ||
+	     event->attr.exclude_callchain_kernel ||
+	     event->attr.exclude_callchain_user)) {
+		/*
+		 * On perf_event with precise_ip, calling bpf_get_stack()
+		 * may trigger unwinder warnings and occasional crashes.
+		 * bpf_get_[stack|stackid] works around this issue by using
+		 * callchain attached to perf_sample_data. If the
+		 * perf_event does not full (kernel and user) callchain
+		 * attached to perf_sample_data, do not allow attaching BPF
+		 * program that calls bpf_get_[stack|stackid].
+		 */
+		bpf_prog_put(prog);
+		return -EPROTO;
+	}
+
 	event->prog = prog;
 	event->orig_overflow_handler = READ_ONCE(event->overflow_handler);
 	WRITE_ONCE(event->overflow_handler, bpf_overflow_handler);
@@ -9221,7 +10003,7 @@
 /*
  * Scan through mm's vmas and see if one of them matches the
  * @filter; if so, adjust filter's address range.
- * Called with mm::mmap_sem down for reading.
+ * Called with mm::mmap_lock down for reading.
  */
 static void perf_addr_filter_apply(struct perf_addr_filter *filter,
 				   struct mm_struct *mm,
@@ -9263,7 +10045,7 @@
 		if (!mm)
 			goto restart;
 
-		down_read(&mm->mmap_sem);
+		mmap_read_lock(mm);
 	}
 
 	raw_spin_lock_irqsave(&ifh->lock, flags);
@@ -9289,7 +10071,7 @@
 	raw_spin_unlock_irqrestore(&ifh->lock, flags);
 
 	if (ifh->nr_file_filters) {
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 
 		mmput(mm);
 	}
@@ -9396,7 +10178,7 @@
 		case IF_SRC_KERNELADDR:
 		case IF_SRC_KERNEL:
 			kernel = 1;
-			/* fall through */
+			fallthrough;
 
 		case IF_SRC_FILEADDR:
 		case IF_SRC_FILE:
@@ -10065,7 +10847,7 @@
 
 int perf_pmu_register(struct pmu *pmu, const char *name, int type)
 {
-	int cpu, ret;
+	int cpu, ret, max = PERF_TYPE_MAX;
 
 	mutex_lock(&pmus_lock);
 	ret = -ENOMEM;
@@ -10078,12 +10860,17 @@
 		goto skip_type;
 	pmu->name = name;
 
-	if (type < 0) {
-		type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
-		if (type < 0) {
-			ret = type;
+	if (type != PERF_TYPE_SOFTWARE) {
+		if (type >= 0)
+			max = type;
+
+		ret = idr_alloc(&pmu_idr, pmu, max, 0, GFP_KERNEL);
+		if (ret < 0)
 			goto free_pdc;
-		}
+
+		WARN_ON(type >= 0 && ret != type);
+
+		type = ret;
 	}
 	pmu->type = type;
 
@@ -10129,6 +10916,9 @@
 		cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask);
 
 		__perf_mux_hrtimer_init(cpuctx, cpu);
+
+		cpuctx->heap_size = ARRAY_SIZE(cpuctx->heap_default);
+		cpuctx->heap = cpuctx->heap_default;
 	}
 
 got_cpu_context:
@@ -10160,7 +10950,16 @@
 	if (!pmu->event_idx)
 		pmu->event_idx = perf_event_idx_default;
 
-	list_add_rcu(&pmu->entry, &pmus);
+	/*
+	 * Ensure the TYPE_SOFTWARE PMUs are at the head of the list,
+	 * since these cannot be in the IDR. This way the linear search
+	 * is fast, provided a valid software event is provided.
+	 */
+	if (type == PERF_TYPE_SOFTWARE || !name)
+		list_add_rcu(&pmu->entry, &pmus);
+	else
+		list_add_tail_rcu(&pmu->entry, &pmus);
+
 	atomic_set(&pmu->exclusive_cnt, 0);
 	ret = 0;
 unlock:
@@ -10173,7 +10972,7 @@
 	put_device(pmu->dev);
 
 free_idr:
-	if (pmu->type >= PERF_TYPE_MAX)
+	if (pmu->type != PERF_TYPE_SOFTWARE)
 		idr_remove(&pmu_idr, pmu->type);
 
 free_pdc:
@@ -10195,7 +10994,7 @@
 	synchronize_rcu();
 
 	free_percpu(pmu->pmu_disable_count);
-	if (pmu->type >= PERF_TYPE_MAX)
+	if (pmu->type != PERF_TYPE_SOFTWARE)
 		idr_remove(&pmu_idr, pmu->type);
 	if (pmu_bus_running) {
 		if (pmu->nr_addr_filters)
@@ -10265,9 +11064,8 @@
 
 static struct pmu *perf_init_event(struct perf_event *event)
 {
+	int idx, type, ret;
 	struct pmu *pmu;
-	int idx;
-	int ret;
 
 	idx = srcu_read_lock(&pmus_srcu);
 
@@ -10279,17 +11077,32 @@
 			goto unlock;
 	}
 
+	/*
+	 * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
+	 * are often aliases for PERF_TYPE_RAW.
+	 */
+	type = event->attr.type;
+	if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE)
+		type = PERF_TYPE_RAW;
+
+again:
 	rcu_read_lock();
-	pmu = idr_find(&pmu_idr, event->attr.type);
+	pmu = idr_find(&pmu_idr, type);
 	rcu_read_unlock();
 	if (pmu) {
 		ret = perf_try_init_event(pmu, event);
+		if (ret == -ENOENT && event->attr.type != type) {
+			type = event->attr.type;
+			goto again;
+		}
+
 		if (ret)
 			pmu = ERR_PTR(ret);
+
 		goto unlock;
 	}
 
-	list_for_each_entry_rcu(pmu, &pmus, entry) {
+	list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) {
 		ret = perf_try_init_event(pmu, event);
 		if (!ret)
 			goto unlock;
@@ -10365,7 +11178,7 @@
 	if (event->parent)
 		return;
 
-	if (event->attach_state & PERF_ATTACH_TASK)
+	if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB))
 		inc = true;
 	if (event->attr.mmap || event->attr.mmap_data)
 		atomic_inc(&nr_mmap_events);
@@ -10373,6 +11186,8 @@
 		atomic_inc(&nr_comm_events);
 	if (event->attr.namespaces)
 		atomic_inc(&nr_namespaces_events);
+	if (event->attr.cgroup)
+		atomic_inc(&nr_cgroup_events);
 	if (event->attr.task)
 		atomic_inc(&nr_task_events);
 	if (event->attr.freq)
@@ -10389,6 +11204,8 @@
 		atomic_inc(&nr_ksymbol_events);
 	if (event->attr.bpf_event)
 		atomic_inc(&nr_bpf_events);
+	if (event->attr.text_poke)
+		atomic_inc(&nr_text_poke_events);
 
 	if (inc) {
 		/*
@@ -10508,12 +11325,9 @@
 		context = parent_event->overflow_handler_context;
 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
 		if (overflow_handler == bpf_overflow_handler) {
-			struct bpf_prog *prog = bpf_prog_inc(parent_event->prog);
+			struct bpf_prog *prog = parent_event->prog;
 
-			if (IS_ERR(prog)) {
-				err = PTR_ERR(prog);
-				goto err_ns;
-			}
+			bpf_prog_inc(prog);
 			event->prog = prog;
 			event->orig_overflow_handler =
 				parent_event->orig_overflow_handler;
@@ -10554,12 +11368,6 @@
 	if (!has_branch_stack(event))
 		event->attr.branch_sample_type = 0;
 
-	if (cgroup_fd != -1) {
-		err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
-		if (err)
-			goto err_ns;
-	}
-
 	pmu = perf_init_event(event);
 	if (IS_ERR(pmu)) {
 		err = PTR_ERR(pmu);
@@ -10581,6 +11389,12 @@
 		goto err_pmu;
 	}
 
+	if (cgroup_fd != -1) {
+		err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
+		if (err)
+			goto err_pmu;
+	}
+
 	err = exclusive_event_init(event);
 	if (err)
 		goto err_pmu;
@@ -10620,11 +11434,20 @@
 		}
 	}
 
+	err = security_perf_event_alloc(event);
+	if (err)
+		goto err_callchain_buffer;
+
 	/* symmetric to unaccount_event() in _free_event() */
 	account_event(event);
 
 	return event;
 
+err_callchain_buffer:
+	if (!event->parent) {
+		if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
+			put_callchain_buffers();
+	}
 err_addr_filters:
 	kfree(event->addr_filter_ranges);
 
@@ -10632,12 +11455,12 @@
 	exclusive_event_destroy(event);
 
 err_pmu:
+	if (is_cgroup_event(event))
+		perf_detach_cgroup(event);
 	if (event->destroy)
 		event->destroy(event);
 	module_put(pmu->module);
 err_ns:
-	if (is_cgroup_event(event))
-		perf_detach_cgroup(event);
 	if (event->ns)
 		put_pid_ns(event->ns);
 	if (event->hw.target)
@@ -10675,7 +11498,7 @@
 
 	attr->size = size;
 
-	if (attr->__reserved_1 || attr->__reserved_2)
+	if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
 		return -EINVAL;
 
 	if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
@@ -10713,9 +11536,11 @@
 			attr->branch_sample_type = mask;
 		}
 		/* privileged levels capture (kernel, hv): check permissions */
-		if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
-		    && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
-			return -EACCES;
+		if (mask & PERF_SAMPLE_BRANCH_PERM_PLM) {
+			ret = perf_allow_kernel(attr);
+			if (ret)
+				return ret;
+		}
 	}
 
 	if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
@@ -10744,6 +11569,12 @@
 
 	if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
 		ret = perf_reg_validate(attr->sample_regs_intr);
+
+#ifndef CONFIG_CGROUP_PERF
+	if (attr->sample_type & PERF_SAMPLE_CGROUP)
+		return -EINVAL;
+#endif
+
 out:
 	return ret;
 
@@ -10756,7 +11587,7 @@
 static int
 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
 {
-	struct ring_buffer *rb = NULL;
+	struct perf_buffer *rb = NULL;
 	int ret = -EINVAL;
 
 	if (!output_event)
@@ -10913,7 +11744,7 @@
 	struct perf_event *group_leader = NULL, *output_event = NULL;
 	struct perf_event *event, *sibling;
 	struct perf_event_attr attr;
-	struct perf_event_context *ctx, *uninitialized_var(gctx);
+	struct perf_event_context *ctx, *gctx;
 	struct file *event_file = NULL;
 	struct fd group = {NULL, 0};
 	struct task_struct *task = NULL;
@@ -10928,17 +11759,23 @@
 	if (flags & ~PERF_FLAG_ALL)
 		return -EINVAL;
 
+	/* Do we allow access to perf_event_open(2) ? */
+	err = security_perf_event_open(&attr, PERF_SECURITY_OPEN);
+	if (err)
+		return err;
+
 	err = perf_copy_attr(attr_uptr, &attr);
 	if (err)
 		return err;
 
 	if (!attr.exclude_kernel) {
-		if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
-			return -EACCES;
+		err = perf_allow_kernel(&attr);
+		if (err)
+			return err;
 	}
 
 	if (attr.namespaces) {
-		if (!capable(CAP_SYS_ADMIN))
+		if (!perfmon_capable())
 			return -EACCES;
 	}
 
@@ -10951,9 +11788,11 @@
 	}
 
 	/* Only privileged users can get physical addresses */
-	if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
-	    perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
-		return -EACCES;
+	if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR)) {
+		err = perf_allow_kernel(&attr);
+		if (err)
+			return err;
+	}
 
 	/* REGS_INTR can leak data, lockdown must prevent this */
 	if (attr.sample_type & PERF_SAMPLE_REGS_INTR) {
@@ -11143,7 +11982,7 @@
 		 * perf_event_exit_task() that could imply).
 		 */
 		err = -EACCES;
-		if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
+		if (!perfmon_capable() && !ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
 			goto err_cred;
 	}
 
@@ -11215,7 +12054,7 @@
 		}
 	}
 
-	if (event->attr.aux_output && !perf_get_aux_event(event, group_leader)) {
+	if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader)) {
 		err = -EINVAL;
 		goto err_locked;
 	}
@@ -11642,7 +12481,7 @@
  * When a child task exits, feed back event values to parent events.
  *
  * Can be called with exec_update_lock held when called from
- * install_exec_creds().
+ * setup_new_exec().
  */
 void perf_event_exit_task(struct task_struct *child)
 {
@@ -11831,8 +12670,7 @@
 	    !child_ctx->task_ctx_data) {
 		struct pmu *pmu = child_event->pmu;
 
-		child_ctx->task_ctx_data = kzalloc(pmu->task_ctx_size,
-						   GFP_KERNEL);
+		child_ctx->task_ctx_data = alloc_task_ctx_data(pmu);
 		if (!child_ctx->task_ctx_data) {
 			free_event(child_event);
 			return ERR_PTR(-ENOMEM);
@@ -12333,6 +13171,12 @@
 	kfree(jc);
 }
 
+static int perf_cgroup_css_online(struct cgroup_subsys_state *css)
+{
+	perf_event_cgroup(css->cgroup);
+	return 0;
+}
+
 static int __perf_cgroup_move(void *info)
 {
 	struct task_struct *task = info;
@@ -12354,6 +13198,7 @@
 struct cgroup_subsys perf_event_cgrp_subsys = {
 	.css_alloc	= perf_cgroup_css_alloc,
 	.css_free	= perf_cgroup_css_free,
+	.css_online	= perf_cgroup_css_online,
 	.attach		= perf_cgroup_attach,
 	/*
 	 * Implicitly enable on dfl hierarchy so that perf events can
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 3cc8416..b48d703 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -213,6 +213,15 @@
 		list_del(&bp->hw.bp_list);
 }
 
+__weak int arch_reserve_bp_slot(struct perf_event *bp)
+{
+	return 0;
+}
+
+__weak void arch_release_bp_slot(struct perf_event *bp)
+{
+}
+
 /*
  * Function to perform processor-specific cleanup during unregistration
  */
@@ -270,6 +279,7 @@
 	struct bp_busy_slots slots = {0};
 	enum bp_type_idx type;
 	int weight;
+	int ret;
 
 	/* We couldn't initialize breakpoint constraints on boot */
 	if (!constraints_initialized)
@@ -294,6 +304,10 @@
 	if (slots.pinned + (!!slots.flexible) > nr_slots[type])
 		return -ENOSPC;
 
+	ret = arch_reserve_bp_slot(bp);
+	if (ret)
+		return ret;
+
 	toggle_bp_slot(bp, true, type, weight);
 
 	return 0;
@@ -317,6 +331,8 @@
 	enum bp_type_idx type;
 	int weight;
 
+	arch_release_bp_slot(bp);
+
 	type = find_slot_idx(bp_type);
 	weight = hw_breakpoint_weight(bp);
 	toggle_bp_slot(bp, false, type, weight);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 6e87b35..228801e 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -10,7 +10,7 @@
 
 #define RING_BUFFER_WRITABLE		0x01
 
-struct ring_buffer {
+struct perf_buffer {
 	refcount_t			refcount;
 	struct rcu_head			rcu_head;
 #ifdef CONFIG_PERF_USE_VMALLOC
@@ -50,24 +50,25 @@
 	unsigned long			aux_mmap_locked;
 	void				(*free_aux)(void *);
 	refcount_t			aux_refcount;
+	int				aux_in_sampling;
 	void				**aux_pages;
 	void				*aux_priv;
 
 	struct perf_event_mmap_page	*user_page;
-	void				*data_pages[0];
+	void				*data_pages[];
 };
 
-extern void rb_free(struct ring_buffer *rb);
+extern void rb_free(struct perf_buffer *rb);
 
 static inline void rb_free_rcu(struct rcu_head *rcu_head)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 
-	rb = container_of(rcu_head, struct ring_buffer, rcu_head);
+	rb = container_of(rcu_head, struct perf_buffer, rcu_head);
 	rb_free(rb);
 }
 
-static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
+static inline void rb_toggle_paused(struct perf_buffer *rb, bool pause)
 {
 	if (!pause && rb->nr_pages)
 		rb->paused = 0;
@@ -75,16 +76,16 @@
 		rb->paused = 1;
 }
 
-extern struct ring_buffer *
+extern struct perf_buffer *
 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
 extern void perf_event_wakeup(struct perf_event *event);
-extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
+extern int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
 			pgoff_t pgoff, int nr_pages, long watermark, int flags);
-extern void rb_free_aux(struct ring_buffer *rb);
-extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
-extern void ring_buffer_put(struct ring_buffer *rb);
+extern void rb_free_aux(struct perf_buffer *rb);
+extern struct perf_buffer *ring_buffer_get(struct perf_event *event);
+extern void ring_buffer_put(struct perf_buffer *rb);
 
-static inline bool rb_has_aux(struct ring_buffer *rb)
+static inline bool rb_has_aux(struct perf_buffer *rb)
 {
 	return !!rb->aux_nr_pages;
 }
@@ -93,7 +94,7 @@
 			  unsigned long size, u64 flags);
 
 extern struct page *
-perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
+perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff);
 
 #ifdef CONFIG_PERF_USE_VMALLOC
 /*
@@ -102,25 +103,25 @@
  * Required for architectures that have d-cache aliasing issues.
  */
 
-static inline int page_order(struct ring_buffer *rb)
+static inline int page_order(struct perf_buffer *rb)
 {
 	return rb->page_order;
 }
 
 #else
 
-static inline int page_order(struct ring_buffer *rb)
+static inline int page_order(struct perf_buffer *rb)
 {
 	return 0;
 }
 #endif
 
-static inline unsigned long perf_data_size(struct ring_buffer *rb)
+static inline unsigned long perf_data_size(struct perf_buffer *rb)
 {
 	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 }
 
-static inline unsigned long perf_aux_size(struct ring_buffer *rb)
+static inline unsigned long perf_aux_size(struct perf_buffer *rb)
 {
 	return rb->aux_nr_pages << PAGE_SHIFT;
 }
@@ -140,7 +141,7 @@
 			buf += written;					\
 		handle->size -= written;				\
 		if (!handle->size) {					\
-			struct ring_buffer *rb = handle->rb;		\
+			struct perf_buffer *rb = handle->rb;	\
 									\
 			handle->page++;					\
 			handle->page &= rb->nr_pages - 1;		\
@@ -204,16 +205,12 @@
 
 static inline int get_recursion_context(int *recursion)
 {
-	int rctx;
+	unsigned int pc = preempt_count();
+	unsigned char rctx = 0;
 
-	if (unlikely(in_nmi()))
-		rctx = 3;
-	else if (in_irq())
-		rctx = 2;
-	else if (in_serving_softirq())
-		rctx = 1;
-	else
-		rctx = 0;
+	rctx += !!(pc & (NMI_MASK));
+	rctx += !!(pc & (NMI_MASK | HARDIRQ_MASK));
+	rctx += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET));
 
 	if (recursion[rctx])
 		return -1;
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index ffb59a4..ef91ae7 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -35,7 +35,7 @@
  */
 static void perf_output_get_handle(struct perf_output_handle *handle)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 
 	preempt_disable();
 
@@ -49,7 +49,7 @@
 
 static void perf_output_put_handle(struct perf_output_handle *handle)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 	unsigned long head;
 	unsigned int nest;
 
@@ -147,10 +147,11 @@
 
 static __always_inline int
 __perf_output_begin(struct perf_output_handle *handle,
+		    struct perf_sample_data *data,
 		    struct perf_event *event, unsigned int size,
 		    bool backward)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	unsigned long tail, offset, head;
 	int have_lost, page_shift;
 	struct {
@@ -237,18 +238,16 @@
 	handle->size = (1UL << page_shift) - offset;
 
 	if (unlikely(have_lost)) {
-		struct perf_sample_data sample_data;
-
 		lost_event.header.size = sizeof(lost_event);
 		lost_event.header.type = PERF_RECORD_LOST;
 		lost_event.header.misc = 0;
 		lost_event.id          = event->id;
 		lost_event.lost        = local_xchg(&rb->lost, 0);
 
-		perf_event_header__init_id(&lost_event.header,
-					   &sample_data, event);
+		/* XXX mostly redundant; @data is already fully initializes */
+		perf_event_header__init_id(&lost_event.header, data, event);
 		perf_output_put(handle, lost_event);
-		perf_event__output_id_sample(event, handle, &sample_data);
+		perf_event__output_id_sample(event, handle, data);
 	}
 
 	return 0;
@@ -263,22 +262,25 @@
 }
 
 int perf_output_begin_forward(struct perf_output_handle *handle,
-			     struct perf_event *event, unsigned int size)
+			      struct perf_sample_data *data,
+			      struct perf_event *event, unsigned int size)
 {
-	return __perf_output_begin(handle, event, size, false);
+	return __perf_output_begin(handle, data, event, size, false);
 }
 
 int perf_output_begin_backward(struct perf_output_handle *handle,
+			       struct perf_sample_data *data,
 			       struct perf_event *event, unsigned int size)
 {
-	return __perf_output_begin(handle, event, size, true);
+	return __perf_output_begin(handle, data, event, size, true);
 }
 
 int perf_output_begin(struct perf_output_handle *handle,
+		      struct perf_sample_data *data,
 		      struct perf_event *event, unsigned int size)
 {
 
-	return __perf_output_begin(handle, event, size,
+	return __perf_output_begin(handle, data, event, size,
 				   unlikely(is_write_backward(event)));
 }
 
@@ -301,7 +303,7 @@
 }
 
 static void
-ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
+ring_buffer_init(struct perf_buffer *rb, long watermark, int flags)
 {
 	long max_size = perf_data_size(rb);
 
@@ -361,7 +363,7 @@
 {
 	struct perf_event *output_event = event;
 	unsigned long aux_head, aux_tail;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	unsigned int nest;
 
 	if (output_event->parent)
@@ -449,7 +451,7 @@
 }
 EXPORT_SYMBOL_GPL(perf_aux_output_begin);
 
-static __always_inline bool rb_need_aux_wakeup(struct ring_buffer *rb)
+static __always_inline bool rb_need_aux_wakeup(struct perf_buffer *rb)
 {
 	if (rb->aux_overwrite)
 		return false;
@@ -475,7 +477,7 @@
 void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
 {
 	bool wakeup = !!(handle->aux_flags & PERF_AUX_FLAG_TRUNCATED);
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 	unsigned long aux_head;
 
 	/* in overwrite mode, driver provides aux_head via handle */
@@ -532,7 +534,7 @@
  */
 int perf_aux_output_skip(struct perf_output_handle *handle, unsigned long size)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 
 	if (size > handle->size)
 		return -ENOSPC;
@@ -562,6 +564,42 @@
 }
 EXPORT_SYMBOL_GPL(perf_get_aux);
 
+/*
+ * Copy out AUX data from an AUX handle.
+ */
+long perf_output_copy_aux(struct perf_output_handle *aux_handle,
+			  struct perf_output_handle *handle,
+			  unsigned long from, unsigned long to)
+{
+	struct perf_buffer *rb = aux_handle->rb;
+	unsigned long tocopy, remainder, len = 0;
+	void *addr;
+
+	from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
+	to &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
+
+	do {
+		tocopy = PAGE_SIZE - offset_in_page(from);
+		if (to > from)
+			tocopy = min(tocopy, to - from);
+		if (!tocopy)
+			break;
+
+		addr = rb->aux_pages[from >> PAGE_SHIFT];
+		addr += offset_in_page(from);
+
+		remainder = perf_output_copy(handle, addr, tocopy);
+		if (remainder)
+			return -EFAULT;
+
+		len += tocopy;
+		from += tocopy;
+		from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
+	} while (to != from);
+
+	return len;
+}
+
 #define PERF_AUX_GFP	(GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY)
 
 static struct page *rb_alloc_aux_page(int node, int order)
@@ -590,7 +628,7 @@
 	return page;
 }
 
-static void rb_free_aux_page(struct ring_buffer *rb, int idx)
+static void rb_free_aux_page(struct perf_buffer *rb, int idx)
 {
 	struct page *page = virt_to_page(rb->aux_pages[idx]);
 
@@ -599,7 +637,7 @@
 	__free_page(page);
 }
 
-static void __rb_free_aux(struct ring_buffer *rb)
+static void __rb_free_aux(struct perf_buffer *rb)
 {
 	int pg;
 
@@ -626,7 +664,7 @@
 	}
 }
 
-int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
+int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
 		 pgoff_t pgoff, int nr_pages, long watermark, int flags)
 {
 	bool overwrite = !(flags & RING_BUFFER_WRITABLE);
@@ -717,7 +755,7 @@
 	return ret;
 }
 
-void rb_free_aux(struct ring_buffer *rb)
+void rb_free_aux(struct perf_buffer *rb)
 {
 	if (refcount_dec_and_test(&rb->aux_refcount))
 		__rb_free_aux(rb);
@@ -730,7 +768,7 @@
  */
 
 static struct page *
-__perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+__perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff)
 {
 	if (pgoff > rb->nr_pages)
 		return NULL;
@@ -754,13 +792,21 @@
 	return page_address(page);
 }
 
-struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+static void perf_mmap_free_page(void *addr)
 {
-	struct ring_buffer *rb;
+	struct page *page = virt_to_page(addr);
+
+	page->mapping = NULL;
+	__free_page(page);
+}
+
+struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+{
+	struct perf_buffer *rb;
 	unsigned long size;
 	int i;
 
-	size = sizeof(struct ring_buffer);
+	size = sizeof(struct perf_buffer);
 	size += nr_pages * sizeof(void *);
 
 	if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
@@ -788,9 +834,9 @@
 
 fail_data_pages:
 	for (i--; i >= 0; i--)
-		free_page((unsigned long)rb->data_pages[i]);
+		perf_mmap_free_page(rb->data_pages[i]);
 
-	free_page((unsigned long)rb->user_page);
+	perf_mmap_free_page(rb->user_page);
 
 fail_user_page:
 	kfree(rb);
@@ -799,32 +845,24 @@
 	return NULL;
 }
 
-static void perf_mmap_free_page(unsigned long addr)
-{
-	struct page *page = virt_to_page((void *)addr);
-
-	page->mapping = NULL;
-	__free_page(page);
-}
-
-void rb_free(struct ring_buffer *rb)
+void rb_free(struct perf_buffer *rb)
 {
 	int i;
 
-	perf_mmap_free_page((unsigned long)rb->user_page);
+	perf_mmap_free_page(rb->user_page);
 	for (i = 0; i < rb->nr_pages; i++)
-		perf_mmap_free_page((unsigned long)rb->data_pages[i]);
+		perf_mmap_free_page(rb->data_pages[i]);
 	kfree(rb);
 }
 
 #else
-static int data_page_nr(struct ring_buffer *rb)
+static int data_page_nr(struct perf_buffer *rb)
 {
 	return rb->nr_pages << page_order(rb);
 }
 
 static struct page *
-__perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+__perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff)
 {
 	/* The '>' counts in the user page. */
 	if (pgoff > data_page_nr(rb))
@@ -842,11 +880,11 @@
 
 static void rb_free_work(struct work_struct *work)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	void *base;
 	int i, nr;
 
-	rb = container_of(work, struct ring_buffer, work);
+	rb = container_of(work, struct perf_buffer, work);
 	nr = data_page_nr(rb);
 
 	base = rb->user_page;
@@ -858,18 +896,18 @@
 	kfree(rb);
 }
 
-void rb_free(struct ring_buffer *rb)
+void rb_free(struct perf_buffer *rb)
 {
 	schedule_work(&rb->work);
 }
 
-struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	unsigned long size;
 	void *all_buf;
 
-	size = sizeof(struct ring_buffer);
+	size = sizeof(struct perf_buffer);
 	size += sizeof(void *);
 
 	rb = kzalloc(size, GFP_KERNEL);
@@ -903,7 +941,7 @@
 #endif
 
 struct page *
-perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff)
 {
 	if (rb->aux_nr_pages) {
 		/* above AUX space */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index a793bd2..e1bbb3b 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -162,14 +162,12 @@
 	};
 	int err;
 	struct mmu_notifier_range range;
-	struct mem_cgroup *memcg;
 
 	mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, addr,
 				addr + PAGE_SIZE);
 
 	if (new_page) {
-		err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL,
-					    &memcg, false);
+		err = mem_cgroup_charge(new_page, vma->vm_mm, GFP_KERNEL);
 		if (err)
 			return err;
 	}
@@ -179,18 +177,14 @@
 
 	mmu_notifier_invalidate_range_start(&range);
 	err = -EAGAIN;
-	if (!page_vma_mapped_walk(&pvmw)) {
-		if (new_page)
-			mem_cgroup_cancel_charge(new_page, memcg, false);
+	if (!page_vma_mapped_walk(&pvmw))
 		goto unlock;
-	}
 	VM_BUG_ON_PAGE(addr != pvmw.address, old_page);
 
 	if (new_page) {
 		get_page(new_page);
 		page_add_new_anon_rmap(new_page, vma, addr, false);
-		mem_cgroup_commit_charge(new_page, memcg, false, false);
-		lru_cache_add_active_or_unevictable(new_page, vma);
+		lru_cache_add_inactive_or_unevictable(new_page, vma);
 	} else
 		/* no new page, just dec_mm_counter for old_page */
 		dec_mm_counter(mm, MM_ANONPAGES);
@@ -382,7 +376,7 @@
 	if (!vaddr || !d)
 		return -EINVAL;
 
-	ret = get_user_pages_remote(NULL, mm, vaddr, 1,
+	ret = get_user_pages_remote(mm, vaddr, 1,
 			FOLL_WRITE, &page, &vma, NULL);
 	if (unlikely(ret <= 0)) {
 		/*
@@ -463,7 +457,7 @@
  * @vaddr: the virtual address to store the opcode.
  * @opcode: opcode to be written at @vaddr.
  *
- * Called with mm->mmap_sem held for write.
+ * Called with mm->mmap_lock held for write.
  * Return 0 (success) or a negative errno.
  */
 int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
@@ -483,7 +477,7 @@
 	if (is_register)
 		gup_flags |= FOLL_SPLIT_PMD;
 	/* Read the page with vaddr into memory */
-	ret = get_user_pages_remote(NULL, mm, vaddr, 1, gup_flags,
+	ret = get_user_pages_remote(mm, vaddr, 1, gup_flags,
 				    &old_page, &vma, NULL);
 	if (ret <= 0)
 		return ret;
@@ -1060,7 +1054,7 @@
 		if (err && is_register)
 			goto free;
 
-		down_write(&mm->mmap_sem);
+		mmap_write_lock(mm);
 		vma = find_vma(mm, info->vaddr);
 		if (!vma || !valid_vma(vma, is_register) ||
 		    file_inode(vma->vm_file) != uprobe->inode)
@@ -1082,7 +1076,7 @@
 		}
 
  unlock:
-		up_write(&mm->mmap_sem);
+		mmap_write_unlock(mm);
  free:
 		mmput(mm);
 		info = free_map_info(info);
@@ -1246,7 +1240,7 @@
 	struct vm_area_struct *vma;
 	int err = 0;
 
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
 		unsigned long vaddr;
 		loff_t offset;
@@ -1263,7 +1257,7 @@
 		vaddr = offset_to_vaddr(vma, uprobe->offset);
 		err |= remove_breakpoint(uprobe, mm, vaddr);
 	}
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	return err;
 }
@@ -1360,7 +1354,7 @@
 }
 
 /*
- * Called from mmap_region/vma_adjust with mm->mmap_sem acquired.
+ * Called from mmap_region/vma_adjust with mm->mmap_lock acquired.
  *
  * Currently we ignore all errors and always return 0, the callers
  * can't handle the failure anyway.
@@ -1450,7 +1444,7 @@
 	struct vm_area_struct *vma;
 	int ret;
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	if (mm->uprobes_state.xol_area) {
@@ -1462,7 +1456,7 @@
 		/* Try to map as high as possible, this is only a hint. */
 		area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE,
 						PAGE_SIZE, 0, 0);
-		if (area->vaddr & ~PAGE_MASK) {
+		if (IS_ERR_VALUE(area->vaddr)) {
 			ret = area->vaddr;
 			goto fail;
 		}
@@ -1480,7 +1474,7 @@
 	/* pairs with get_xol_area() */
 	smp_store_release(&mm->uprobes_state.xol_area, area); /* ^^^ */
  fail:
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 
 	return ret;
 }
@@ -1679,7 +1673,7 @@
 	copy_to_page(page, vaddr, src, len);
 
 	/*
-	 * We probably need flush_icache_user_range() but it needs vma.
+	 * We probably need flush_icache_user_page() but it needs vma.
 	 * This should work on most of architectures by default. If
 	 * architecture needs to do something different it can define
 	 * its own version of the function.
@@ -1741,7 +1735,7 @@
 }
 
 /*
- * Allocate a uprobe_task object for the task if if necessary.
+ * Allocate a uprobe_task object for the task if necessary.
  * Called when the thread hits a breakpoint.
  *
  * Returns:
@@ -1829,7 +1823,7 @@
 
 	t->utask->dup_xol_addr = area->vaddr;
 	init_task_work(&t->utask->dup_xol_work, dup_xol_work);
-	task_work_add(t, &t->utask->dup_xol_work, true);
+	task_work_add(t, &t->utask->dup_xol_work, TWA_RESUME);
 }
 
 /*
@@ -2035,7 +2029,7 @@
 	 * but we treat this as a 'remote' access since it is
 	 * essentially a kernel access to the memory.
 	 */
-	result = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &page,
+	result = get_user_pages_remote(mm, vaddr, 1, FOLL_FORCE, &page,
 			NULL, NULL);
 	if (result < 0)
 		return result;
@@ -2053,7 +2047,7 @@
 	struct uprobe *uprobe = NULL;
 	struct vm_area_struct *vma;
 
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 	vma = find_vma(mm, bp_vaddr);
 	if (vma && vma->vm_start <= bp_vaddr) {
 		if (valid_vma(vma, false)) {
@@ -2071,7 +2065,7 @@
 
 	if (!uprobe && test_and_clear_bit(MMF_RECALC_UPROBES, &mm->flags))
 		mmf_recalc_uprobes(mm);
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	return uprobe;
 }
@@ -2195,7 +2189,7 @@
 {
 	struct uprobe *uprobe;
 	unsigned long bp_vaddr;
-	int uninitialized_var(is_swbp);
+	int is_swbp;
 
 	bp_vaddr = uprobe_get_swbp_addr(regs);
 	if (bp_vaddr == get_trampoline_vaddr())
diff --git a/kernel/exit.c b/kernel/exit.c
index ece6477..d13d67f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -63,10 +63,10 @@
 #include <linux/random.h>
 #include <linux/rcuwait.h>
 #include <linux/compat.h>
+#include <linux/io_uring.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
-#include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 
 static void __unhash_process(struct task_struct *p, bool group_dead)
@@ -94,7 +94,7 @@
 	struct signal_struct *sig = tsk->signal;
 	bool group_dead = thread_group_leader(tsk);
 	struct sighand_struct *sighand;
-	struct tty_struct *uninitialized_var(tty);
+	struct tty_struct *tty;
 	u64 utime, stime;
 
 	sighand = rcu_dereference_check(tsk->sighand,
@@ -103,17 +103,8 @@
 
 #ifdef CONFIG_POSIX_TIMERS
 	posix_cpu_timers_exit(tsk);
-	if (group_dead) {
+	if (group_dead)
 		posix_cpu_timers_exit_group(tsk);
-	} else {
-		/*
-		 * This can only happen if the caller is de_thread().
-		 * FIXME: this is the temporary hack, we should teach
-		 * posix-cpu-timers to handle this case correctly.
-		 */
-		if (unlikely(has_group_leader_pid(tsk)))
-			posix_cpu_timers_exit_group(tsk);
-	}
 #endif
 
 	if (group_dead) {
@@ -191,6 +182,7 @@
 void release_task(struct task_struct *p)
 {
 	struct task_struct *leader;
+	struct pid *thread_pid;
 	int zap_leader;
 repeat:
 	/* don't need to get the RCU readlock here - the process is dead and
@@ -199,11 +191,11 @@
 	atomic_dec(&__task_cred(p)->user->processes);
 	rcu_read_unlock();
 
-	proc_flush_task(p);
 	cgroup_release(p);
 
 	write_lock_irq(&tasklist_lock);
 	ptrace_release_task(p);
+	thread_pid = get_pid(p->thread_pid);
 	__exit_signal(p);
 
 	/*
@@ -226,6 +218,9 @@
 	}
 
 	write_unlock_irq(&tasklist_lock);
+	seccomp_filter_release(p);
+	proc_flush_pid(thread_pid);
+	put_pid(thread_pid);
 	release_thread(p);
 	put_task_struct_rcu_user(p);
 
@@ -234,8 +229,9 @@
 		goto repeat;
 }
 
-void rcuwait_wake_up(struct rcuwait *w)
+int rcuwait_wake_up(struct rcuwait *w)
 {
+	int ret = 0;
 	struct task_struct *task;
 
 	rcu_read_lock();
@@ -243,7 +239,7 @@
 	/*
 	 * Order condition vs @task, such that everything prior to the load
 	 * of @task is visible. This is the condition as to why the user called
-	 * rcuwait_trywake() in the first place. Pairs with set_current_state()
+	 * rcuwait_wake() in the first place. Pairs with set_current_state()
 	 * barrier (A) in rcuwait_wait_event().
 	 *
 	 *    WAIT                WAKE
@@ -255,9 +251,12 @@
 
 	task = rcu_dereference(w->task);
 	if (task)
-		wake_up_process(task);
+		ret = wake_up_process(task);
 	rcu_read_unlock();
+
+	return ret;
 }
+EXPORT_SYMBOL_GPL(rcuwait_wake_up);
 
 /*
  * Determine if a process group is "orphaned", according to the POSIX
@@ -443,17 +442,17 @@
 	sync_mm_rss(mm);
 	/*
 	 * Serialize with any possible pending coredump.
-	 * We must hold mmap_sem around checking core_state
+	 * We must hold mmap_lock around checking core_state
 	 * and clearing tsk->mm.  The core-inducing thread
 	 * will increment ->nr_threads for each thread in the
 	 * group with ->mm != NULL.
 	 */
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 	core_state = mm->core_state;
 	if (core_state) {
 		struct core_thread self;
 
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 
 		self.task = current;
 		if (self.task->flags & PF_SIGNALED)
@@ -474,14 +473,14 @@
 			freezable_schedule();
 		}
 		__set_current_state(TASK_RUNNING);
-		down_read(&mm->mmap_sem);
+		mmap_read_lock(mm);
 	}
 	mmgrab(mm);
 	BUG_ON(mm != current->active_mm);
 	/* more a memory barrier than a real lock */
 	task_lock(current);
 	current->mm = NULL;
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 	enter_lazy_tlb(mm, current);
 	task_unlock(current);
 	mm_update_next_owner(mm);
@@ -622,8 +621,8 @@
 	reaper = find_new_reaper(father, reaper);
 	list_for_each_entry(p, &father->children, sibling) {
 		for_each_thread(p, t) {
-			t->real_parent = reaper;
-			BUG_ON((!t->ptrace) != (t->parent == father));
+			RCU_INIT_POINTER(t->real_parent, reaper);
+			BUG_ON((!t->ptrace) != (rcu_access_pointer(t->parent) == father));
 			if (likely(!t->ptrace))
 				t->parent = t->real_parent;
 			if (t->pdeath_signal)
@@ -737,7 +736,7 @@
 	 * mm_release()->clear_child_tid() from writing to a user-controlled
 	 * kernel address.
 	 */
-	set_fs(USER_DS);
+	force_uaccess_begin();
 
 	if (unlikely(in_atomic())) {
 		pr_info("note: %s[%d] exited with preempt_count %d\n",
@@ -764,6 +763,7 @@
 		schedule();
 	}
 
+	io_uring_files_cancel(tsk->files);
 	exit_signals(tsk);  /* sets PF_EXITING */
 
 	/* sync mm's RSS info before statistics gathering */
@@ -810,7 +810,6 @@
 	exit_task_namespaces(tsk);
 	exit_task_work(tsk);
 	exit_thread(tsk);
-	exit_umh(tsk);
 
 	/*
 	 * Flush inherited counters to the parent - before the parent
@@ -1423,7 +1422,7 @@
 void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
 {
 	__wake_up_sync_key(&parent->signal->wait_chldexit,
-				TASK_INTERRUPTIBLE, 1, p);
+			   TASK_INTERRUPTIBLE, p);
 }
 
 static long do_wait(struct wait_opts *wo)
@@ -1445,7 +1444,7 @@
 	 */
 	wo->notask_error = -ECHILD;
 	if ((wo->wo_type < PIDTYPE_MAX) &&
-	   (!wo->wo_pid || hlist_empty(&wo->wo_pid->tasks[wo->wo_type])))
+	   (!wo->wo_pid || !pid_has_task(wo->wo_pid, wo->wo_type)))
 		goto notask;
 
 	set_current_state(TASK_INTERRUPTIBLE);
@@ -1480,23 +1479,6 @@
 	return retval;
 }
 
-static struct pid *pidfd_get_pid(unsigned int fd)
-{
-	struct fd f;
-	struct pid *pid;
-
-	f = fdget(fd);
-	if (!f.file)
-		return ERR_PTR(-EBADF);
-
-	pid = pidfd_pid(f.file);
-	if (!IS_ERR(pid))
-		get_pid(pid);
-
-	fdput(f);
-	return pid;
-}
-
 static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
 			  int options, struct rusage *ru)
 {
@@ -1504,6 +1486,7 @@
 	struct pid *pid = NULL;
 	enum pid_type type;
 	long ret;
+	unsigned int f_flags = 0;
 
 	if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED|
 			__WNOTHREAD|__WCLONE|__WALL))
@@ -1537,9 +1520,10 @@
 		if (upid < 0)
 			return -EINVAL;
 
-		pid = pidfd_get_pid(upid);
+		pid = pidfd_get_pid(upid, &f_flags);
 		if (IS_ERR(pid))
 			return PTR_ERR(pid);
+
 		break;
 	default:
 		return -EINVAL;
@@ -1550,7 +1534,12 @@
 	wo.wo_flags	= options;
 	wo.wo_info	= infop;
 	wo.wo_rusage	= ru;
+	if (f_flags & O_NONBLOCK)
+		wo.wo_flags |= WNOHANG;
+
 	ret = do_wait(&wo);
+	if (!ret && !(options & WNOHANG) && (f_flags & O_NONBLOCK))
+		ret = -EAGAIN;
 
 	put_pid(pid);
 	return ret;
@@ -1573,7 +1562,7 @@
 	if (!infop)
 		return err;
 
-	if (!user_access_begin(infop, sizeof(*infop)))
+	if (!user_write_access_begin(infop, sizeof(*infop)))
 		return -EFAULT;
 
 	unsafe_put_user(signo, &infop->si_signo, Efault);
@@ -1582,10 +1571,10 @@
 	unsafe_put_user(info.pid, &infop->si_pid, Efault);
 	unsafe_put_user(info.uid, &infop->si_uid, Efault);
 	unsafe_put_user(info.status, &infop->si_status, Efault);
-	user_access_end();
+	user_write_access_end();
 	return err;
 Efault:
-	user_access_end();
+	user_write_access_end();
 	return -EFAULT;
 }
 
@@ -1632,6 +1621,22 @@
 	return ret;
 }
 
+int kernel_wait(pid_t pid, int *stat)
+{
+	struct wait_opts wo = {
+		.wo_type	= PIDTYPE_PID,
+		.wo_pid		= find_get_pid(pid),
+		.wo_flags	= WEXITED,
+	};
+	int ret;
+
+	ret = do_wait(&wo);
+	if (ret > 0 && wo.wo_stat)
+		*stat = wo.wo_stat;
+	put_pid(wo.wo_pid);
+	return ret;
+}
+
 SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
 		int, options, struct rusage __user *, ru)
 {
@@ -1700,7 +1705,7 @@
 	if (!infop)
 		return err;
 
-	if (!user_access_begin(infop, sizeof(*infop)))
+	if (!user_write_access_begin(infop, sizeof(*infop)))
 		return -EFAULT;
 
 	unsafe_put_user(signo, &infop->si_signo, Efault);
@@ -1709,14 +1714,38 @@
 	unsafe_put_user(info.pid, &infop->si_pid, Efault);
 	unsafe_put_user(info.uid, &infop->si_uid, Efault);
 	unsafe_put_user(info.status, &infop->si_status, Efault);
-	user_access_end();
+	user_write_access_end();
 	return err;
 Efault:
-	user_access_end();
+	user_write_access_end();
 	return -EFAULT;
 }
 #endif
 
+/**
+ * thread_group_exited - check that a thread group has exited
+ * @pid: tgid of thread group to be checked.
+ *
+ * Test if the thread group represented by tgid has exited (all
+ * threads are zombies, dead or completely gone).
+ *
+ * Return: true if the thread group has exited. false otherwise.
+ */
+bool thread_group_exited(struct pid *pid)
+{
+	struct task_struct *task;
+	bool exited;
+
+	rcu_read_lock();
+	task = pid_task(pid, PIDTYPE_PID);
+	exited = !task ||
+		(READ_ONCE(task->exit_state) && thread_group_empty(task));
+	rcu_read_unlock();
+
+	return exited;
+}
+EXPORT_SYMBOL(thread_group_exited);
+
 __weak void abort(void)
 {
 	BUG();
diff --git a/kernel/extable.c b/kernel/extable.c
index f6c9406..b0ea5eb 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -34,7 +34,8 @@
 /* Sort the kernel's built-in exception table */
 void __init sort_main_extable(void)
 {
-	if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) {
+	if (main_extable_sort_needed &&
+	    &__stop___ex_table > &__start___ex_table) {
 		pr_notice("Sorting __ex_table...\n");
 		sort_extable(__start___ex_table, __stop___ex_table);
 	}
@@ -56,6 +57,8 @@
 	e = search_kernel_exception_table(addr);
 	if (!e)
 		e = search_module_extables(addr);
+	if (!e)
+		e = search_bpf_extables(addr);
 	return e;
 }
 
@@ -129,8 +132,9 @@
 	 * triggers a stack trace, or a WARN() that happens during
 	 * coming back from idle, or cpu on or offlining.
 	 *
-	 * is_module_text_address() as well as the kprobe slots
-	 * and is_bpf_text_address() require RCU to be watching.
+	 * is_module_text_address() as well as the kprobe slots,
+	 * is_bpf_text_address() and is_bpf_image_address require
+	 * RCU to be watching.
 	 */
 	no_rcu = !rcu_is_watching();
 
diff --git a/kernel/fork.c b/kernel/fork.c
index cf2cebd..a78c0b0 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -40,7 +40,6 @@
 #include <linux/binfmts.h>
 #include <linux/mman.h>
 #include <linux/mmu_notifier.h>
-#include <linux/hmm.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/vmacache.h>
@@ -94,8 +93,10 @@
 #include <linux/livepatch.h>
 #include <linux/thread_info.h>
 #include <linux/stackleak.h>
+#include <linux/kasan.h>
+#include <linux/scs.h>
+#include <linux/io_uring.h>
 
-#include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <linux/uaccess.h>
 #include <asm/mmu_context.h>
@@ -224,6 +225,9 @@
 		if (!s)
 			continue;
 
+		/* Clear the KASAN shadow of the stack. */
+		kasan_unpoison_shadow(s->addr, THREAD_SIZE);
+
 		/* Clear stale pointers from reused stack. */
 		memset(s->addr, 0, THREAD_SIZE);
 
@@ -258,7 +262,7 @@
 					     THREAD_SIZE_ORDER);
 
 	if (likely(page)) {
-		tsk->stack = page_address(page);
+		tsk->stack = kasan_reset_tag(page_address(page));
 		return tsk->stack;
 	}
 	return NULL;
@@ -273,13 +277,8 @@
 	if (vm) {
 		int i;
 
-		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
-			mod_memcg_page_state(vm->pages[i],
-					     MEMCG_KERNEL_STACK_KB,
-					     -(int)(PAGE_SIZE / 1024));
-
-			memcg_kmem_uncharge(vm->pages[i], 0);
-		}
+		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
+			memcg_kmem_uncharge_page(vm->pages[i], 0);
 
 		for (i = 0; i < NR_CACHED_STACKS; i++) {
 			if (this_cpu_cmpxchg(cached_stacks[i],
@@ -304,6 +303,7 @@
 {
 	unsigned long *stack;
 	stack = kmem_cache_alloc_node(thread_stack_cache, THREADINFO_GFP, node);
+	stack = kasan_reset_tag(stack);
 	tsk->stack = stack;
 	return stack;
 }
@@ -356,8 +356,15 @@
 	struct vm_area_struct *new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
 
 	if (new) {
-		*new = *orig;
+		ASSERT_EXCLUSIVE_WRITER(orig->vm_flags);
+		ASSERT_EXCLUSIVE_WRITER(orig->vm_file);
+		/*
+		 * orig->shared.rb may be modified concurrently, but the clone
+		 * will be reinitialized.
+		 */
+		*new = data_race(*orig);
 		INIT_LIST_HEAD(&new->anon_vma_chain);
+		new->vm_next = new->vm_prev = NULL;
 	}
 	return new;
 }
@@ -372,31 +379,14 @@
 	void *stack = task_stack_page(tsk);
 	struct vm_struct *vm = task_stack_vm_area(tsk);
 
-	BUILD_BUG_ON(IS_ENABLED(CONFIG_VMAP_STACK) && PAGE_SIZE % 1024 != 0);
 
-	if (vm) {
-		int i;
-
-		BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
-
-		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
-			mod_zone_page_state(page_zone(vm->pages[i]),
-					    NR_KERNEL_STACK_KB,
-					    PAGE_SIZE / 1024 * account);
-		}
-	} else {
-		/*
-		 * All stack pages are in the same zone and belong to the
-		 * same memcg.
-		 */
-		struct page *first_page = virt_to_page(stack);
-
-		mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB,
-				    THREAD_SIZE / 1024 * account);
-
-		mod_memcg_obj_state(stack, MEMCG_KERNEL_STACK_KB,
-				    account * (THREAD_SIZE / 1024));
-	}
+	/* All stack pages are in the same node. */
+	if (vm)
+		mod_lruvec_page_state(vm->pages[0], NR_KERNEL_STACK_KB,
+				      account * (THREAD_SIZE / 1024));
+	else
+		mod_lruvec_slab_state(stack, NR_KERNEL_STACK_KB,
+				      account * (THREAD_SIZE / 1024));
 }
 
 static int memcg_charge_kernel_stack(struct task_struct *tsk)
@@ -405,23 +395,23 @@
 	struct vm_struct *vm = task_stack_vm_area(tsk);
 	int ret;
 
+	BUILD_BUG_ON(IS_ENABLED(CONFIG_VMAP_STACK) && PAGE_SIZE % 1024 != 0);
+
 	if (vm) {
 		int i;
 
+		BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
+
 		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
 			/*
-			 * If memcg_kmem_charge() fails, page->mem_cgroup
-			 * pointer is NULL, and both memcg_kmem_uncharge()
-			 * and mod_memcg_page_state() in free_thread_stack()
-			 * will ignore this page. So it's safe.
+			 * If memcg_kmem_charge_page() fails, page->mem_cgroup
+			 * pointer is NULL, and memcg_kmem_uncharge_page() in
+			 * free_thread_stack() will ignore this page.
 			 */
-			ret = memcg_kmem_charge(vm->pages[i], GFP_KERNEL, 0);
+			ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL,
+						     0);
 			if (ret)
 				return ret;
-
-			mod_memcg_page_state(vm->pages[i],
-					     MEMCG_KERNEL_STACK_KB,
-					     PAGE_SIZE / 1024);
 		}
 	}
 #endif
@@ -451,6 +441,8 @@
 
 void free_task(struct task_struct *tsk)
 {
+	scs_release(tsk);
+
 #ifndef CONFIG_THREAD_INFO_IN_TASK
 	/*
 	 * The task is finally done with both the stack and thread_info,
@@ -466,7 +458,6 @@
 #endif
 	rt_mutex_debug_task_free(tsk);
 	ftrace_graph_exit_task(tsk);
-	put_seccomp_filter(tsk);
 	arch_release_task_struct(tsk);
 	if (tsk->flags & PF_KTHREAD)
 		free_kthread_struct(tsk);
@@ -485,7 +476,7 @@
 	LIST_HEAD(uf);
 
 	uprobe_start_dup_mmap();
-	if (down_write_killable(&oldmm->mmap_sem)) {
+	if (mmap_write_lock_killable(oldmm)) {
 		retval = -EINTR;
 		goto fail_uprobe_end;
 	}
@@ -494,7 +485,7 @@
 	/*
 	 * Not linked in yet - no deadlock potential:
 	 */
-	down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
+	mmap_write_lock_nested(mm, SINGLE_DEPTH_NESTING);
 
 	/* No ordering required: file already has been exposed. */
 	RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm));
@@ -549,14 +540,15 @@
 		if (retval)
 			goto fail_nomem_anon_vma_fork;
 		if (tmp->vm_flags & VM_WIPEONFORK) {
-			/* VM_WIPEONFORK gets a clean slate in the child. */
+			/*
+			 * VM_WIPEONFORK gets a clean slate in the child.
+			 * Don't prepare anon_vma until fault since we don't
+			 * copy page for current vma.
+			 */
 			tmp->anon_vma = NULL;
-			if (anon_vma_prepare(tmp))
-				goto fail_nomem_anon_vma_fork;
 		} else if (anon_vma_fork(tmp, mpnt))
 			goto fail_nomem_anon_vma_fork;
 		tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT);
-		tmp->vm_next = tmp->vm_prev = NULL;
 		file = tmp->vm_file;
 		if (file) {
 			struct inode *inode = file_inode(file);
@@ -564,10 +556,10 @@
 
 			get_file(file);
 			if (tmp->vm_flags & VM_DENYWRITE)
-				atomic_dec(&inode->i_writecount);
+				put_write_access(inode);
 			i_mmap_lock_write(mapping);
 			if (tmp->vm_flags & VM_SHARED)
-				atomic_inc(&mapping->i_mmap_writable);
+				mapping_allow_writable(mapping);
 			flush_dcache_mmap_lock(mapping);
 			/* insert tmp into the share list, just after mpnt */
 			vma_interval_tree_insert_after(tmp, mpnt,
@@ -598,7 +590,7 @@
 
 		mm->map_count++;
 		if (!(tmp->vm_flags & VM_WIPEONFORK))
-			retval = copy_page_range(mm, oldmm, mpnt);
+			retval = copy_page_range(tmp, mpnt);
 
 		if (tmp->vm_ops && tmp->vm_ops->open)
 			tmp->vm_ops->open(tmp);
@@ -609,9 +601,9 @@
 	/* a new mm has just been created */
 	retval = arch_dup_mmap(oldmm, mm);
 out:
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	flush_tlb_mm(oldmm);
-	up_write(&oldmm->mmap_sem);
+	mmap_write_unlock(oldmm);
 	dup_userfaultfd_complete(&uf);
 fail_uprobe_end:
 	uprobe_end_dup_mmap();
@@ -641,9 +633,9 @@
 #else
 static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 {
-	down_write(&oldmm->mmap_sem);
+	mmap_write_lock(oldmm);
 	RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm));
-	up_write(&oldmm->mmap_sem);
+	mmap_write_unlock(oldmm);
 	return 0;
 }
 #define mm_alloc_pgd(mm)	(0)
@@ -689,7 +681,7 @@
 	WARN_ON_ONCE(mm == current->active_mm);
 	mm_free_pgd(mm);
 	destroy_context(mm);
-	mmu_notifier_mm_destroy(mm);
+	mmu_notifier_subscriptions_destroy(mm);
 	check_mm(mm);
 	put_user_ns(mm->user_ns);
 	free_mm(mm);
@@ -737,6 +729,7 @@
 	WARN_ON(refcount_read(&tsk->usage));
 	WARN_ON(tsk == current);
 
+	io_uring_free(tsk);
 	cgroup_free(tsk);
 	task_numa_free(tsk, true);
 	security_task_free(tsk);
@@ -834,6 +827,8 @@
 			  NULL, free_vm_stack_cache);
 #endif
 
+	scs_init();
+
 	lockdep_init_task(&init_task);
 	uprobes_init();
 }
@@ -893,6 +888,10 @@
 	if (err)
 		goto free_stack;
 
+	err = scs_prepare(tsk, node);
+	if (err)
+		goto free_stack;
+
 #ifdef CONFIG_SECCOMP
 	/*
 	 * We must handle setting up seccomp filters once we're under
@@ -993,6 +992,13 @@
 #endif
 }
 
+static void mm_init_pasid(struct mm_struct *mm)
+{
+#ifdef CONFIG_IOMMU_SUPPORT
+	mm->pasid = INIT_PASID;
+#endif
+}
+
 static void mm_init_uprobes_state(struct mm_struct *mm)
 {
 #ifdef CONFIG_UPROBES
@@ -1008,12 +1014,14 @@
 	mm->vmacache_seqnum = 0;
 	atomic_set(&mm->mm_users, 1);
 	atomic_set(&mm->mm_count, 1);
-	init_rwsem(&mm->mmap_sem);
+	seqcount_init(&mm->write_protect_seq);
+	mmap_init_lock(mm);
 	INIT_LIST_HEAD(&mm->mmlist);
 	mm->core_state = NULL;
 	mm_pgtables_bytes_init(mm);
 	mm->map_count = 0;
 	mm->locked_vm = 0;
+	atomic_set(&mm->has_pinned, 0);
 	atomic64_set(&mm->pinned_vm, 0);
 	memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
 	spin_lock_init(&mm->page_table_lock);
@@ -1021,8 +1029,9 @@
 	mm_init_cpumask(mm);
 	mm_init_aio(mm);
 	mm_init_owner(mm, p);
+	mm_init_pasid(mm);
 	RCU_INIT_POINTER(mm->exe_file, NULL);
-	mmu_notifier_mm_init(mm);
+	mmu_notifier_subscriptions_init(mm);
 	init_tlb_flush_pending(mm);
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
 	mm->pmd_huge_pte = NULL;
@@ -1461,7 +1470,7 @@
 		goto out;
 	}
 
-	newf = dup_fd(oldf, &error);
+	newf = dup_fd(oldf, NR_OPEN_MAX, &error);
 	if (!newf)
 		goto out;
 
@@ -1506,7 +1515,7 @@
 		return 0;
 	}
 	sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
-	rcu_assign_pointer(tsk->sighand, sig);
+	RCU_INIT_POINTER(tsk->sighand, sig);
 	if (!sig)
 		return -ENOMEM;
 
@@ -1514,6 +1523,11 @@
 	spin_lock_irq(&current->sighand->siglock);
 	memcpy(sig->action, current->sighand->action, sizeof(sig->action));
 	spin_unlock_irq(&current->sighand->siglock);
+
+	/* Reset all signal handler not set to SIG_IGN to SIG_DFL. */
+	if (clone_flags & CLONE_CLEAR_SIGHAND)
+		flush_signal_handlers(tsk, 0);
+
 	return 0;
 }
 
@@ -1673,6 +1687,11 @@
 	INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
 	p->rcu_tasks_idle_cpu = -1;
 #endif /* #ifdef CONFIG_TASKS_RCU */
+#ifdef CONFIG_TASKS_TRACE_RCU
+	p->trc_reader_nesting = 0;
+	p->trc_reader_special.s = 0;
+	INIT_LIST_HEAD(&p->trc_holdout_list);
+#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
 }
 
 struct pid *pidfd_pid(const struct file *file)
@@ -1693,12 +1712,68 @@
 }
 
 #ifdef CONFIG_PROC_FS
+/**
+ * pidfd_show_fdinfo - print information about a pidfd
+ * @m: proc fdinfo file
+ * @f: file referencing a pidfd
+ *
+ * Pid:
+ * This function will print the pid that a given pidfd refers to in the
+ * pid namespace of the procfs instance.
+ * If the pid namespace of the process is not a descendant of the pid
+ * namespace of the procfs instance 0 will be shown as its pid. This is
+ * similar to calling getppid() on a process whose parent is outside of
+ * its pid namespace.
+ *
+ * NSpid:
+ * If pid namespaces are supported then this function will also print
+ * the pid of a given pidfd refers to for all descendant pid namespaces
+ * starting from the current pid namespace of the instance, i.e. the
+ * Pid field and the first entry in the NSpid field will be identical.
+ * If the pid namespace of the process is not a descendant of the pid
+ * namespace of the procfs instance 0 will be shown as its first NSpid
+ * entry and no others will be shown.
+ * Note that this differs from the Pid and NSpid fields in
+ * /proc/<pid>/status where Pid and NSpid are always shown relative to
+ * the  pid namespace of the procfs instance. The difference becomes
+ * obvious when sending around a pidfd between pid namespaces from a
+ * different branch of the tree, i.e. where no ancestoral relation is
+ * present between the pid namespaces:
+ * - create two new pid namespaces ns1 and ns2 in the initial pid
+ *   namespace (also take care to create new mount namespaces in the
+ *   new pid namespace and mount procfs)
+ * - create a process with a pidfd in ns1
+ * - send pidfd from ns1 to ns2
+ * - read /proc/self/fdinfo/<pidfd> and observe that both Pid and NSpid
+ *   have exactly one entry, which is 0
+ */
 static void pidfd_show_fdinfo(struct seq_file *m, struct file *f)
 {
-	struct pid_namespace *ns = proc_pid_ns(file_inode(m->file));
 	struct pid *pid = f->private_data;
+	struct pid_namespace *ns;
+	pid_t nr = -1;
 
-	seq_put_decimal_ull(m, "Pid:\t", pid_nr_ns(pid, ns));
+	if (likely(pid_has_task(pid, PIDTYPE_PID))) {
+		ns = proc_pid_ns(file_inode(m->file)->i_sb);
+		nr = pid_nr_ns(pid, ns);
+	}
+
+	seq_put_decimal_ll(m, "Pid:\t", nr);
+
+#ifdef CONFIG_PID_NS
+	seq_put_decimal_ll(m, "\nNSpid:\t", nr);
+	if (nr > 0) {
+		int i;
+
+		/* If nr is non-zero it means that 'pid' is valid and that
+		 * ns, i.e. the pid namespace associated with the procfs
+		 * instance, is in the pid namespace hierarchy of pid.
+		 * Start at one below the already printed level.
+		 */
+		for (i = ns->level + 1; i <= pid->level; i++)
+			seq_put_decimal_ll(m, "\t", pid->numbers[i].nr);
+	}
+#endif
 	seq_putc(m, '\n');
 }
 #endif
@@ -1708,22 +1783,18 @@
  */
 static __poll_t pidfd_poll(struct file *file, struct poll_table_struct *pts)
 {
-	struct task_struct *task;
 	struct pid *pid = file->private_data;
 	__poll_t poll_flags = 0;
 
 	poll_wait(file, &pid->wait_pidfd, pts);
 
-	rcu_read_lock();
-	task = pid_task(pid, PIDTYPE_PID);
 	/*
 	 * Inform pollers only when the whole thread group exits.
 	 * If the thread group leader exits before all other threads in the
 	 * group, then poll(2) should block, similar to the wait(2) family.
 	 */
-	if (!task || (task->exit_state && thread_group_empty(task)))
+	if (thread_group_exited(pid))
 		poll_flags = EPOLLIN | EPOLLRDNORM;
-	rcu_read_unlock();
 
 	return poll_flags;
 }
@@ -1789,6 +1860,7 @@
 	struct multiprocess_signals delayed;
 	struct file *pidfile = NULL;
 	u64 clone_flags = args->flags;
+	struct nsproxy *nsp = current->nsproxy;
 
 	/*
 	 * Don't allow sharing the root directory with processes in a different
@@ -1831,8 +1903,16 @@
 	 */
 	if (clone_flags & CLONE_THREAD) {
 		if ((clone_flags & (CLONE_NEWUSER | CLONE_NEWPID)) ||
-		    (task_active_pid_ns(current) !=
-				current->nsproxy->pid_ns_for_children))
+		    (task_active_pid_ns(current) != nsp->pid_ns_for_children))
+			return ERR_PTR(-EINVAL);
+	}
+
+	/*
+	 * If the new process will be in a different time namespace
+	 * do not allow it to share VM or a thread group with the forking task.
+	 */
+	if (clone_flags & (CLONE_THREAD | CLONE_VM)) {
+		if (nsp->time_ns != nsp->time_ns_for_children)
 			return ERR_PTR(-EINVAL);
 	}
 
@@ -1885,8 +1965,8 @@
 
 	rt_mutex_init_task(p);
 
+	lockdep_assert_irqs_enabled();
 #ifdef CONFIG_PROVE_LOCKING
-	DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
 	DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
 #endif
 	retval = -EAGAIN;
@@ -1908,7 +1988,7 @@
 	 * to stop root fork bombs.
 	 */
 	retval = -EAGAIN;
-	if (nr_threads >= max_threads)
+	if (data_race(nr_threads >= max_threads))
 		goto bad_fork_cleanup_count;
 
 	delayacct_tsk_init(p);	/* Must remain after dup_task_struct() */
@@ -1934,6 +2014,10 @@
 	p->vtime.state = VTIME_INACTIVE;
 #endif
 
+#ifdef CONFIG_IO_URING
+	p->io_uring = NULL;
+#endif
+
 #if defined(SPLIT_RSS_COUNTING)
 	memset(&p->rss_stat, 0, sizeof(p->rss_stat));
 #endif
@@ -1963,22 +2047,14 @@
 #ifdef CONFIG_CPUSETS
 	p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
 	p->cpuset_slab_spread_rotor = NUMA_NO_NODE;
-	seqcount_init(&p->mems_allowed_seq);
+	seqcount_spinlock_init(&p->mems_allowed_seq, &p->alloc_lock);
 #endif
 #ifdef CONFIG_TRACE_IRQFLAGS
-	p->irq_events = 0;
-	p->hardirqs_enabled = 0;
-	p->hardirq_enable_ip = 0;
-	p->hardirq_enable_event = 0;
-	p->hardirq_disable_ip = _THIS_IP_;
-	p->hardirq_disable_event = 0;
-	p->softirqs_enabled = 1;
-	p->softirq_enable_ip = _THIS_IP_;
-	p->softirq_enable_event = 0;
-	p->softirq_disable_ip = 0;
-	p->softirq_disable_event = 0;
-	p->hardirq_context = 0;
-	p->softirq_context = 0;
+	memset(&p->irqtrace, 0, sizeof(p->irqtrace));
+	p->irqtrace.hardirq_disable_ip	= _THIS_IP_;
+	p->irqtrace.softirq_enable_ip	= _THIS_IP_;
+	p->softirqs_enabled		= 1;
+	p->softirq_context		= 0;
 #endif
 
 	p->pagefault_disabled = 0;
@@ -2035,15 +2111,15 @@
 	retval = copy_io(clone_flags, p);
 	if (retval)
 		goto bad_fork_cleanup_namespaces;
-	retval = copy_thread_tls(clone_flags, args->stack, args->stack_size, p,
-				 args->tls);
+	retval = copy_thread(clone_flags, args->stack, args->stack_size, p, args->tls);
 	if (retval)
 		goto bad_fork_cleanup_io;
 
 	stackleak_task_init(p);
 
 	if (pid != &init_struct_pid) {
-		pid = alloc_pid(p->nsproxy->pid_ns_for_children);
+		pid = alloc_pid(p->nsproxy->pid_ns_for_children, args->set_tid,
+				args->set_tid_size);
 		if (IS_ERR(pid)) {
 			retval = PTR_ERR(pid);
 			goto bad_fork_cleanup_thread;
@@ -2115,17 +2191,17 @@
 	p->pdeath_signal = 0;
 	INIT_LIST_HEAD(&p->thread_group);
 	p->task_works = NULL;
+	clear_posix_cputimers_work(p);
 
-	cgroup_threadgroup_change_begin(current);
 	/*
 	 * Ensure that the cgroup subsystem policies allow the new process to be
-	 * forked. It should be noted the the new process's css_set can be changed
+	 * forked. It should be noted that the new process's css_set can be changed
 	 * between here and cgroup_post_fork() if an organisation operation is in
 	 * progress.
 	 */
-	retval = cgroup_can_fork(p);
+	retval = cgroup_can_fork(p, args);
 	if (retval)
-		goto bad_fork_cgroup_threadgroup_change_end;
+		goto bad_fork_put_pidfd;
 
 	/*
 	 * From this point on we must avoid any synchronous user-space
@@ -2136,7 +2212,7 @@
 	 */
 
 	p->start_time = ktime_get_ns();
-	p->real_start_time = ktime_get_boottime_ns();
+	p->start_boottime = ktime_get_boottime_ns();
 
 	/*
 	 * Make it visible to the rest of the system, but dont wake it up yet.
@@ -2182,10 +2258,6 @@
 		goto bad_fork_cancel_cgroup;
 	}
 
-	/* past the last point of failure */
-	if (pidfile)
-		fd_install(pidfd, pidfile);
-
 	init_task_pid_links(p);
 	if (likely(p->pid)) {
 		ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
@@ -2234,9 +2306,12 @@
 	syscall_tracepoint_update(p);
 	write_unlock_irq(&tasklist_lock);
 
+	if (pidfile)
+		fd_install(pidfd, pidfile);
+
 	proc_fork_connector(p);
-	cgroup_post_fork(p);
-	cgroup_threadgroup_change_end(current);
+	sched_post_fork(p, args);
+	cgroup_post_fork(p, args);
 	perf_event_fork(p);
 
 	trace_task_newtask(p, clone_flags);
@@ -2249,9 +2324,7 @@
 bad_fork_cancel_cgroup:
 	spin_unlock(&current->sighand->siglock);
 	write_unlock_irq(&tasklist_lock);
-	cgroup_cancel_fork(p);
-bad_fork_cgroup_threadgroup_change_end:
-	cgroup_threadgroup_change_end(current);
+	cgroup_cancel_fork(p, args);
 bad_fork_put_pidfd:
 	if (clone_flags & CLONE_PIDFD) {
 		fput(pidfile);
@@ -2320,7 +2393,7 @@
 	}
 }
 
-struct task_struct *fork_idle(int cpu)
+struct task_struct * __init fork_idle(int cpu)
 {
 	struct task_struct *task;
 	struct kernel_clone_args args = {
@@ -2349,14 +2422,28 @@
  *
  * args->exit_signal is expected to be checked for sanity by the caller.
  */
-long _do_fork(struct kernel_clone_args *args)
+pid_t kernel_clone(struct kernel_clone_args *args)
 {
 	u64 clone_flags = args->flags;
 	struct completion vfork;
 	struct pid *pid;
 	struct task_struct *p;
 	int trace = 0;
-	long nr;
+	pid_t nr;
+
+	/*
+	 * For legacy clone() calls, CLONE_PIDFD uses the parent_tid argument
+	 * to return the pidfd. Hence, CLONE_PIDFD and CLONE_PARENT_SETTID are
+	 * mutually exclusive. With clone3() CLONE_PIDFD has grown a separate
+	 * field in struct clone_args and it still doesn't make sense to have
+	 * them both point at the same memory location. Performing this check
+	 * here has the advantage that we don't need to have a separate helper
+	 * to check for legacy clone().
+	 */
+	if ((args->flags & CLONE_PIDFD) &&
+	    (args->flags & CLONE_PARENT_SETTID) &&
+	    (args->pidfd == args->parent_tid))
+		return -EINVAL;
 
 	/*
 	 * Determine whether and which event to report to ptracer.  When
@@ -2415,42 +2502,6 @@
 	return nr;
 }
 
-bool legacy_clone_args_valid(const struct kernel_clone_args *kargs)
-{
-	/* clone(CLONE_PIDFD) uses parent_tidptr to return a pidfd */
-	if ((kargs->flags & CLONE_PIDFD) &&
-	    (kargs->flags & CLONE_PARENT_SETTID))
-		return false;
-
-	return true;
-}
-
-#ifndef CONFIG_HAVE_COPY_THREAD_TLS
-/* For compatibility with architectures that call do_fork directly rather than
- * using the syscall entry points below. */
-long do_fork(unsigned long clone_flags,
-	      unsigned long stack_start,
-	      unsigned long stack_size,
-	      int __user *parent_tidptr,
-	      int __user *child_tidptr)
-{
-	struct kernel_clone_args args = {
-		.flags		= (lower_32_bits(clone_flags) & ~CSIGNAL),
-		.pidfd		= parent_tidptr,
-		.child_tid	= child_tidptr,
-		.parent_tid	= parent_tidptr,
-		.exit_signal	= (lower_32_bits(clone_flags) & CSIGNAL),
-		.stack		= stack_start,
-		.stack_size	= stack_size,
-	};
-
-	if (!legacy_clone_args_valid(&args))
-		return -EINVAL;
-
-	return _do_fork(&args);
-}
-#endif
-
 /*
  * Create a kernel thread.
  */
@@ -2464,7 +2515,7 @@
 		.stack_size	= (unsigned long)arg,
 	};
 
-	return _do_fork(&args);
+	return kernel_clone(&args);
 }
 
 #ifdef __ARCH_WANT_SYS_FORK
@@ -2475,7 +2526,7 @@
 		.exit_signal = SIGCHLD,
 	};
 
-	return _do_fork(&args);
+	return kernel_clone(&args);
 #else
 	/* can not support in nommu mode */
 	return -EINVAL;
@@ -2491,7 +2542,7 @@
 		.exit_signal	= SIGCHLD,
 	};
 
-	return _do_fork(&args);
+	return kernel_clone(&args);
 }
 #endif
 
@@ -2529,30 +2580,27 @@
 		.tls		= tls,
 	};
 
-	if (!legacy_clone_args_valid(&args))
-		return -EINVAL;
-
-	return _do_fork(&args);
+	return kernel_clone(&args);
 }
 #endif
 
 #ifdef __ARCH_WANT_SYS_CLONE3
 
-/*
- * copy_thread implementations handle CLONE_SETTLS by reading the TLS value from
- * the registers containing the syscall arguments for clone. This doesn't work
- * with clone3 since the TLS value is passed in clone_args instead.
- */
-#ifndef CONFIG_HAVE_COPY_THREAD_TLS
-#error clone3 requires copy_thread_tls support in arch
-#endif
-
 noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
 					      struct clone_args __user *uargs,
 					      size_t usize)
 {
 	int err;
 	struct clone_args args;
+	pid_t *kset_tid = kargs->set_tid;
+
+	BUILD_BUG_ON(offsetofend(struct clone_args, tls) !=
+		     CLONE_ARGS_SIZE_VER0);
+	BUILD_BUG_ON(offsetofend(struct clone_args, set_tid_size) !=
+		     CLONE_ARGS_SIZE_VER1);
+	BUILD_BUG_ON(offsetofend(struct clone_args, cgroup) !=
+		     CLONE_ARGS_SIZE_VER2);
+	BUILD_BUG_ON(sizeof(struct clone_args) != CLONE_ARGS_SIZE_VER2);
 
 	if (unlikely(usize > PAGE_SIZE))
 		return -E2BIG;
@@ -2563,6 +2611,15 @@
 	if (err)
 		return err;
 
+	if (unlikely(args.set_tid_size > MAX_PID_NS_LEVEL))
+		return -EINVAL;
+
+	if (unlikely(!args.set_tid && args.set_tid_size > 0))
+		return -EINVAL;
+
+	if (unlikely(args.set_tid && args.set_tid_size == 0))
+		return -EINVAL;
+
 	/*
 	 * Verify that higher 32bits of exit_signal are unset and that
 	 * it is a valid signal
@@ -2571,6 +2628,10 @@
 		     !valid_signal(args.exit_signal)))
 		return -EINVAL;
 
+	if ((args.flags & CLONE_INTO_CGROUP) &&
+	    (args.cgroup > INT_MAX || usize < CLONE_ARGS_SIZE_VER2))
+		return -EINVAL;
+
 	*kargs = (struct kernel_clone_args){
 		.flags		= args.flags,
 		.pidfd		= u64_to_user_ptr(args.pidfd),
@@ -2580,8 +2641,17 @@
 		.stack		= args.stack,
 		.stack_size	= args.stack_size,
 		.tls		= args.tls,
+		.set_tid_size	= args.set_tid_size,
+		.cgroup		= args.cgroup,
 	};
 
+	if (args.set_tid &&
+		copy_from_user(kset_tid, u64_to_user_ptr(args.set_tid),
+			(kargs->set_tid_size * sizeof(pid_t))))
+		return -EFAULT;
+
+	kargs->set_tid = kset_tid;
+
 	return 0;
 }
 
@@ -2615,11 +2685,9 @@
 
 static bool clone3_args_valid(struct kernel_clone_args *kargs)
 {
-	/*
-	 * All lower bits of the flag word are taken.
-	 * Verify that no other unknown flags are passed along.
-	 */
-	if (kargs->flags & ~CLONE_LEGACY_FLAGS)
+	/* Verify that no unknown flags are passed along. */
+	if (kargs->flags &
+	    ~(CLONE_LEGACY_FLAGS | CLONE_CLEAR_SIGHAND | CLONE_INTO_CGROUP))
 		return false;
 
 	/*
@@ -2629,6 +2697,10 @@
 	if (kargs->flags & (CLONE_DETACHED | CSIGNAL))
 		return false;
 
+	if ((kargs->flags & (CLONE_SIGHAND | CLONE_CLEAR_SIGHAND)) ==
+	    (CLONE_SIGHAND | CLONE_CLEAR_SIGHAND))
+		return false;
+
 	if ((kargs->flags & (CLONE_THREAD | CLONE_PARENT)) &&
 	    kargs->exit_signal)
 		return false;
@@ -2655,6 +2727,9 @@
 	int err;
 
 	struct kernel_clone_args kargs;
+	pid_t set_tid[MAX_PID_NS_LEVEL];
+
+	kargs.set_tid = set_tid;
 
 	err = copy_clone_args_from_user(&kargs, uargs, size);
 	if (err)
@@ -2663,7 +2738,7 @@
 	if (!clone3_args_valid(&kargs))
 		return -EINVAL;
 
-	return _do_fork(&kargs);
+	return kernel_clone(&kargs);
 }
 #endif
 
@@ -2758,7 +2833,8 @@
 	if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
 				CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
 				CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET|
-				CLONE_NEWUSER|CLONE_NEWPID|CLONE_NEWCGROUP))
+				CLONE_NEWUSER|CLONE_NEWPID|CLONE_NEWCGROUP|
+				CLONE_NEWTIME))
 		return -EINVAL;
 	/*
 	 * Not implemented, but pretend it works if there is nothing
@@ -2806,14 +2882,15 @@
 /*
  * Unshare file descriptor table if it is being shared
  */
-static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp)
+int unshare_fd(unsigned long unshare_flags, unsigned int max_fds,
+	       struct files_struct **new_fdp)
 {
 	struct files_struct *fd = current->files;
 	int error = 0;
 
 	if ((unshare_flags & CLONE_FILES) &&
 	    (fd && atomic_read(&fd->count) > 1)) {
-		*new_fdp = dup_fd(fd, &error);
+		*new_fdp = dup_fd(fd, max_fds, &error);
 		if (!*new_fdp)
 			return error;
 	}
@@ -2824,7 +2901,7 @@
 /*
  * unshare allows a process to 'unshare' part of the process
  * context which was originally shared using clone.  copy_*
- * functions used by do_fork() cannot be used here directly
+ * functions used by kernel_clone() cannot be used here directly
  * because they modify an inactive task_struct that is being
  * constructed. Here we are modifying the current, active,
  * task_struct.
@@ -2873,7 +2950,7 @@
 	err = unshare_fs(unshare_flags, &new_fs);
 	if (err)
 		goto bad_unshare_out;
-	err = unshare_fd(unshare_flags, &new_fd);
+	err = unshare_fd(unshare_flags, NR_OPEN_MAX, &new_fd);
 	if (err)
 		goto bad_unshare_cleanup_fs;
 	err = unshare_userns(unshare_flags, &new_cred);
@@ -2962,7 +3039,7 @@
 	struct files_struct *copy = NULL;
 	int error;
 
-	error = unshare_fd(CLONE_FILES, &copy);
+	error = unshare_fd(CLONE_FILES, NR_OPEN_MAX, &copy);
 	if (error || !copy) {
 		*displaced = NULL;
 		return error;
@@ -2975,7 +3052,7 @@
 }
 
 int sysctl_max_threads(struct ctl_table *table, int write,
-		       void __user *buffer, size_t *lenp, loff_t *ppos)
+		       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	int ret;
diff --git a/kernel/futex.c b/kernel/futex.c
index f82879a..98a6e1b 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -32,30 +32,13 @@
  *  "But they come in a choice of three flavours!"
  */
 #include <linux/compat.h>
-#include <linux/slab.h>
-#include <linux/poll.h>
-#include <linux/fs.h>
-#include <linux/file.h>
 #include <linux/jhash.h>
-#include <linux/init.h>
-#include <linux/futex.h>
-#include <linux/mount.h>
 #include <linux/pagemap.h>
 #include <linux/syscalls.h>
-#include <linux/signal.h>
-#include <linux/export.h>
-#include <linux/magic.h>
-#include <linux/pid.h>
-#include <linux/nsproxy.h>
-#include <linux/ptrace.h>
-#include <linux/sched/rt.h>
-#include <linux/sched/wake_q.h>
-#include <linux/sched/mm.h>
-#include <linux/hugetlb.h>
 #include <linux/freezer.h>
 #include <linux/memblock.h>
 #include <linux/fault-inject.h>
-#include <linux/refcount.h>
+#include <linux/time_namespace.h>
 
 #include <asm/futex.h>
 
@@ -135,8 +118,7 @@
  *
  * Where (A) orders the waiters increment and the futex value read through
  * atomic operations (see hb_waiters_inc) and where (B) orders the write
- * to futex and the waiters read -- this is done by the barriers for both
- * shared and private futexes in get_futex_key_refs().
+ * to futex and the waiters read (see hb_waiters_pending()).
  *
  * This yields the following case (where X:=waiters, Y:=futex):
  *
@@ -331,17 +313,6 @@
 static inline void compat_exit_robust_list(struct task_struct *curr) { }
 #endif
 
-static inline void futex_get_mm(union futex_key *key)
-{
-	mmgrab(key->private.mm);
-	/*
-	 * Ensure futex_get_mm() implies a full barrier such that
-	 * get_futex_key() implies a full barrier. This is relied upon
-	 * as smp_mb(); (B), see the ordering comment above.
-	 */
-	smp_mb__after_atomic();
-}
-
 /*
  * Reflects a new waiter being added to the waitqueue.
  */
@@ -370,6 +341,10 @@
 static inline int hb_waiters_pending(struct futex_hash_bucket *hb)
 {
 #ifdef CONFIG_SMP
+	/*
+	 * Full barrier (B), see the ordering comment above.
+	 */
+	smp_mb();
 	return atomic_read(&hb->waiters);
 #else
 	return 1;
@@ -407,69 +382,6 @@
 		&& key1->both.offset == key2->both.offset);
 }
 
-/*
- * Take a reference to the resource addressed by a key.
- * Can be called while holding spinlocks.
- *
- */
-static void get_futex_key_refs(union futex_key *key)
-{
-	if (!key->both.ptr)
-		return;
-
-	/*
-	 * On MMU less systems futexes are always "private" as there is no per
-	 * process address space. We need the smp wmb nevertheless - yes,
-	 * arch/blackfin has MMU less SMP ...
-	 */
-	if (!IS_ENABLED(CONFIG_MMU)) {
-		smp_mb(); /* explicit smp_mb(); (B) */
-		return;
-	}
-
-	switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
-	case FUT_OFF_INODE:
-		smp_mb();		/* explicit smp_mb(); (B) */
-		break;
-	case FUT_OFF_MMSHARED:
-		futex_get_mm(key); /* implies smp_mb(); (B) */
-		break;
-	default:
-		/*
-		 * Private futexes do not hold reference on an inode or
-		 * mm, therefore the only purpose of calling get_futex_key_refs
-		 * is because we need the barrier for the lockless waiter check.
-		 */
-		smp_mb(); /* explicit smp_mb(); (B) */
-	}
-}
-
-/*
- * Drop a reference to the resource addressed by a key.
- * The hash bucket spinlock must not be held. This is
- * a no-op for private futexes, see comment in the get
- * counterpart.
- */
-static void drop_futex_key_refs(union futex_key *key)
-{
-	if (!key->both.ptr) {
-		/* If we're here then we tried to put a key we failed to get */
-		WARN_ON_ONCE(1);
-		return;
-	}
-
-	if (!IS_ENABLED(CONFIG_MMU))
-		return;
-
-	switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
-	case FUT_OFF_INODE:
-		break;
-	case FUT_OFF_MMSHARED:
-		mmdrop(key->private.mm);
-		break;
-	}
-}
-
 enum futex_access {
 	FUTEX_READ,
 	FUTEX_WRITE
@@ -547,7 +459,7 @@
 /**
  * get_futex_key() - Get parameters which are the keys for a futex
  * @uaddr:	virtual address of the futex
- * @fshared:	0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
+ * @fshared:	false for a PROCESS_PRIVATE futex, true for PROCESS_SHARED
  * @key:	address where result is stored.
  * @rw:		mapping needs to be read/write (values: FUTEX_READ,
  *              FUTEX_WRITE)
@@ -557,10 +469,13 @@
  * The key words are stored in @key on success.
  *
  * For shared mappings (when @fshared), the key is:
+ *
  *   ( inode->i_sequence, page->index, offset_within_page )
+ *
  * [ also see get_inode_sequence_number() ]
  *
  * For private mappings (or when !@fshared), the key is:
+ *
  *   ( current->mm, address, 0 )
  *
  * This allows (cross process, where applicable) identification of the futex
@@ -568,8 +483,8 @@
  *
  * lock_page() might sleep, the caller should not hold a spinlock.
  */
-static int
-get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, enum futex_access rw)
+static int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key,
+			 enum futex_access rw)
 {
 	unsigned long address = (unsigned long)uaddr;
 	struct mm_struct *mm = current->mm;
@@ -601,13 +516,12 @@
 	if (!fshared) {
 		key->private.mm = mm;
 		key->private.address = address;
-		get_futex_key_refs(key);  /* implies smp_mb(); (B) */
 		return 0;
 	}
 
 again:
 	/* Ignore any VERIFY_READ mapping (futex common case) */
-	if (unlikely(should_fail_futex(fshared)))
+	if (unlikely(should_fail_futex(true)))
 		return -EFAULT;
 
 	err = get_user_pages_fast(address, 1, FOLL_WRITE, &page);
@@ -695,7 +609,7 @@
 		 * A RO anonymous page will never change and thus doesn't make
 		 * sense for futex operations.
 		 */
-		if (unlikely(should_fail_futex(fshared)) || ro) {
+		if (unlikely(should_fail_futex(true)) || ro) {
 			err = -EFAULT;
 			goto out;
 		}
@@ -741,18 +655,11 @@
 		rcu_read_unlock();
 	}
 
-	get_futex_key_refs(key); /* implies smp_mb(); (B) */
-
 out:
 	put_page(page);
 	return err;
 }
 
-static inline void put_futex_key(union futex_key *key)
-{
-	drop_futex_key_refs(key);
-}
-
 /**
  * fault_in_user_writeable() - Fault in user address and verify RW access
  * @uaddr:	pointer to faulting user space address
@@ -770,10 +677,10 @@
 	struct mm_struct *mm = current->mm;
 	int ret;
 
-	down_read(&mm->mmap_sem);
-	ret = fixup_user_fault(current, mm, (unsigned long)uaddr,
+	mmap_read_lock(mm);
+	ret = fixup_user_fault(mm, (unsigned long)uaddr,
 			       FAULT_FLAG_WRITE, NULL);
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	return ret < 0 ? ret : 0;
 }
@@ -1027,7 +934,7 @@
  * [10] Found  | Found    | task      | !=taskTID | 0/1    | Invalid
  *
  * [1]	Indicates that the kernel can acquire the futex atomically. We
- *	came came here due to a stale FUTEX_WAITERS/FUTEX_OWNER_DIED bit.
+ *	came here due to a stale FUTEX_WAITERS/FUTEX_OWNER_DIED bit.
  *
  * [2]	Valid, if TID does not belong to a kernel thread. If no matching
  *      thread is found then it indicates that the owner TID has died.
@@ -1214,6 +1121,7 @@
 
 /**
  * wait_for_owner_exiting - Block until the owner has exited
+ * @ret: owner's current futex lock status
  * @exiting:	Pointer to the exiting task
  *
  * Caller must hold a refcount on @exiting.
@@ -1416,7 +1324,7 @@
 static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval)
 {
 	int err;
-	u32 uninitialized_var(curval);
+	u32 curval;
 
 	if (unlikely(should_fail_futex(true)))
 		return -EFAULT;
@@ -1576,7 +1484,7 @@
 
 	/*
 	 * Queue the task for later wakeup for after we've released
-	 * the hb->lock. wake_q_add() grabs reference to p.
+	 * the hb->lock.
 	 */
 	wake_q_add_safe(wake_q, p);
 }
@@ -1586,7 +1494,7 @@
  */
 static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_state)
 {
-	u32 uninitialized_var(curval), newval;
+	u32 curval, newval;
 	struct task_struct *new_owner;
 	bool postunlock = false;
 	DEFINE_WAKE_Q(wake_q);
@@ -1692,13 +1600,13 @@
 
 	ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key, FUTEX_READ);
 	if (unlikely(ret != 0))
-		goto out;
+		return ret;
 
 	hb = hash_futex(&key);
 
 	/* Make sure we really have tasks to wakeup */
 	if (!hb_waiters_pending(hb))
-		goto out_put_key;
+		return ret;
 
 	spin_lock(&hb->lock);
 
@@ -1721,9 +1629,6 @@
 
 	spin_unlock(&hb->lock);
 	wake_up_q(&wake_q);
-out_put_key:
-	put_futex_key(&key);
-out:
 	return ret;
 }
 
@@ -1749,10 +1654,9 @@
 		oparg = 1 << oparg;
 	}
 
-	if (!access_ok(uaddr, sizeof(u32)))
-		return -EFAULT;
-
+	pagefault_disable();
 	ret = arch_futex_atomic_op_inuser(op, oparg, &oldval, uaddr);
+	pagefault_enable();
 	if (ret)
 		return ret;
 
@@ -1791,10 +1695,10 @@
 retry:
 	ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ);
 	if (unlikely(ret != 0))
-		goto out;
+		return ret;
 	ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE);
 	if (unlikely(ret != 0))
-		goto out_put_key1;
+		return ret;
 
 	hb1 = hash_futex(&key1);
 	hb2 = hash_futex(&key2);
@@ -1812,13 +1716,13 @@
 			 * an MMU, but we might get them from range checking
 			 */
 			ret = op_ret;
-			goto out_put_keys;
+			return ret;
 		}
 
 		if (op_ret == -EFAULT) {
 			ret = fault_in_user_writeable(uaddr2);
 			if (ret)
-				goto out_put_keys;
+				return ret;
 		}
 
 		if (!(flags & FLAGS_SHARED)) {
@@ -1826,8 +1730,6 @@
 			goto retry_private;
 		}
 
-		put_futex_key(&key2);
-		put_futex_key(&key1);
 		cond_resched();
 		goto retry;
 	}
@@ -1863,11 +1765,6 @@
 out_unlock:
 	double_unlock_hb(hb1, hb2);
 	wake_up_q(&wake_q);
-out_put_keys:
-	put_futex_key(&key2);
-out_put_key1:
-	put_futex_key(&key1);
-out:
 	return ret;
 }
 
@@ -1894,7 +1791,6 @@
 		plist_add(&q->list, &hb2->chain);
 		q->lock_ptr = &hb2->lock;
 	}
-	get_futex_key_refs(key2);
 	q->key = *key2;
 }
 
@@ -1916,7 +1812,6 @@
 void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
 			   struct futex_hash_bucket *hb)
 {
-	get_futex_key_refs(key);
 	q->key = *key;
 
 	__unqueue_futex(q);
@@ -2027,7 +1922,7 @@
 			 u32 *cmpval, int requeue_pi)
 {
 	union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
-	int drop_count = 0, task_count = 0, ret;
+	int task_count = 0, ret;
 	struct futex_pi_state *pi_state = NULL;
 	struct futex_hash_bucket *hb1, *hb2;
 	struct futex_q *this, *next;
@@ -2076,20 +1971,18 @@
 retry:
 	ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ);
 	if (unlikely(ret != 0))
-		goto out;
+		return ret;
 	ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2,
 			    requeue_pi ? FUTEX_WRITE : FUTEX_READ);
 	if (unlikely(ret != 0))
-		goto out_put_key1;
+		return ret;
 
 	/*
 	 * The check above which compares uaddrs is not sufficient for
 	 * shared futexes. We need to compare the keys:
 	 */
-	if (requeue_pi && match_futex(&key1, &key2)) {
-		ret = -EINVAL;
-		goto out_put_keys;
-	}
+	if (requeue_pi && match_futex(&key1, &key2))
+		return -EINVAL;
 
 	hb1 = hash_futex(&key1);
 	hb2 = hash_futex(&key2);
@@ -2109,13 +2002,11 @@
 
 			ret = get_user(curval, uaddr1);
 			if (ret)
-				goto out_put_keys;
+				return ret;
 
 			if (!(flags & FLAGS_SHARED))
 				goto retry_private;
 
-			put_futex_key(&key2);
-			put_futex_key(&key1);
 			goto retry;
 		}
 		if (curval != *cmpval) {
@@ -2148,7 +2039,6 @@
 		 */
 		if (ret > 0) {
 			WARN_ON(pi_state);
-			drop_count++;
 			task_count++;
 			/*
 			 * If we acquired the lock, then the user space value
@@ -2175,12 +2065,10 @@
 		case -EFAULT:
 			double_unlock_hb(hb1, hb2);
 			hb_waiters_dec(hb2);
-			put_futex_key(&key2);
-			put_futex_key(&key1);
 			ret = fault_in_user_writeable(uaddr2);
 			if (!ret)
 				goto retry;
-			goto out;
+			return ret;
 		case -EBUSY:
 		case -EAGAIN:
 			/*
@@ -2191,8 +2079,6 @@
 			 */
 			double_unlock_hb(hb1, hb2);
 			hb_waiters_dec(hb2);
-			put_futex_key(&key2);
-			put_futex_key(&key1);
 			/*
 			 * Handle the case where the owner is in the middle of
 			 * exiting. Wait for the exit to complete otherwise
@@ -2268,7 +2154,6 @@
 				 * doing so.
 				 */
 				requeue_pi_wake_futex(this, &key2, hb2);
-				drop_count++;
 				continue;
 			} else if (ret) {
 				/*
@@ -2289,7 +2174,6 @@
 			}
 		}
 		requeue_futex(this, hb1, hb2, &key2);
-		drop_count++;
 	}
 
 	/*
@@ -2303,21 +2187,6 @@
 	double_unlock_hb(hb1, hb2);
 	wake_up_q(&wake_q);
 	hb_waiters_dec(hb2);
-
-	/*
-	 * drop_futex_key_refs() must be called outside the spinlocks. During
-	 * the requeue we moved futex_q's from the hash bucket at key1 to the
-	 * one at key2 and updated their key pointer.  We no longer need to
-	 * hold the references to key1.
-	 */
-	while (--drop_count >= 0)
-		drop_futex_key_refs(&key1);
-
-out_put_keys:
-	put_futex_key(&key2);
-out_put_key1:
-	put_futex_key(&key1);
-out:
 	return ret ? ret : task_count;
 }
 
@@ -2442,7 +2311,6 @@
 		ret = 1;
 	}
 
-	drop_futex_key_refs(&q->key);
 	return ret;
 }
 
@@ -2466,9 +2334,9 @@
 static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
 				  struct task_struct *argowner)
 {
-	u32 uval, uninitialized_var(curval), newval, newtid;
 	struct futex_pi_state *pi_state = q->pi_state;
 	struct task_struct *oldowner, *newowner;
+	u32 uval, curval, newval, newtid;
 	int err = 0;
 
 	oldowner = pi_state->owner;
@@ -2797,12 +2665,11 @@
 
 		ret = get_user(uval, uaddr);
 		if (ret)
-			goto out;
+			return ret;
 
 		if (!(flags & FLAGS_SHARED))
 			goto retry_private;
 
-		put_futex_key(&q->key);
 		goto retry;
 	}
 
@@ -2811,9 +2678,6 @@
 		ret = -EWOULDBLOCK;
 	}
 
-out:
-	if (ret)
-		put_futex_key(&q->key);
 	return ret;
 }
 
@@ -2956,7 +2820,6 @@
 			 * - EAGAIN: The user space value changed.
 			 */
 			queue_unlock(hb);
-			put_futex_key(&q.key);
 			/*
 			 * Handle the case where the owner is in the middle of
 			 * exiting. Wait for the exit to complete otherwise
@@ -3049,14 +2912,11 @@
 
 	/* Unqueue and drop the lock */
 	unqueue_me_pi(&q);
-
-	goto out_put_key;
+	goto out;
 
 out_unlock_put_key:
 	queue_unlock(hb);
 
-out_put_key:
-	put_futex_key(&q.key);
 out:
 	if (to) {
 		hrtimer_cancel(&to->timer);
@@ -3069,12 +2929,11 @@
 
 	ret = fault_in_user_writeable(uaddr);
 	if (ret)
-		goto out_put_key;
+		goto out;
 
 	if (!(flags & FLAGS_SHARED))
 		goto retry_private;
 
-	put_futex_key(&q.key);
 	goto retry;
 }
 
@@ -3085,7 +2944,7 @@
  */
 static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
 {
-	u32 uninitialized_var(curval), uval, vpid = task_pid_vnr(current);
+	u32 curval, uval, vpid = task_pid_vnr(current);
 	union futex_key key = FUTEX_KEY_INIT;
 	struct futex_hash_bucket *hb;
 	struct futex_q *top_waiter;
@@ -3203,16 +3062,13 @@
 out_unlock:
 	spin_unlock(&hb->lock);
 out_putkey:
-	put_futex_key(&key);
 	return ret;
 
 pi_retry:
-	put_futex_key(&key);
 	cond_resched();
 	goto retry;
 
 pi_faulted:
-	put_futex_key(&key);
 
 	ret = fault_in_user_writeable(uaddr);
 	if (!ret)
@@ -3353,7 +3209,7 @@
 	 */
 	ret = futex_wait_setup(uaddr, val, flags, &q, &hb);
 	if (ret)
-		goto out_key2;
+		goto out;
 
 	/*
 	 * The check above which compares uaddrs is not sufficient for
@@ -3362,7 +3218,7 @@
 	if (match_futex(&q.key, &key2)) {
 		queue_unlock(hb);
 		ret = -EINVAL;
-		goto out_put_keys;
+		goto out;
 	}
 
 	/* Queue the futex_q, drop the hb lock, wait for wakeup. */
@@ -3372,7 +3228,7 @@
 	ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
 	spin_unlock(&hb->lock);
 	if (ret)
-		goto out_put_keys;
+		goto out;
 
 	/*
 	 * In order for us to be here, we know our q.key == key2, and since
@@ -3448,11 +3304,6 @@
 		ret = -EWOULDBLOCK;
 	}
 
-out_put_keys:
-	put_futex_key(&q.key);
-out_key2:
-	put_futex_key(&key2);
-
 out:
 	if (to) {
 		hrtimer_cancel(&to->timer);
@@ -3553,7 +3404,7 @@
 static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr,
 			      bool pi, bool pending_op)
 {
-	u32 uval, uninitialized_var(nval), mval;
+	u32 uval, nval, mval;
 	int err;
 
 	/* Futex address must be 32bit aligned */
@@ -3683,7 +3534,7 @@
 	struct robust_list_head __user *head = curr->robust_list;
 	struct robust_list __user *entry, *next_entry, *pending;
 	unsigned int limit = ROBUST_LIST_LIMIT, pi, pip;
-	unsigned int uninitialized_var(next_pi);
+	unsigned int next_pi;
 	unsigned long futex_offset;
 	int rc;
 
@@ -3879,12 +3730,12 @@
 	switch (cmd) {
 	case FUTEX_WAIT:
 		val3 = FUTEX_BITSET_MATCH_ANY;
-		/* fall through */
+		fallthrough;
 	case FUTEX_WAIT_BITSET:
 		return futex_wait(uaddr, flags, val, timeout, val3);
 	case FUTEX_WAKE:
 		val3 = FUTEX_BITSET_MATCH_ANY;
-		/* fall through */
+		fallthrough;
 	case FUTEX_WAKE_BITSET:
 		return futex_wake(uaddr, flags, val, val3);
 	case FUTEX_REQUEUE:
@@ -3932,6 +3783,8 @@
 		t = timespec64_to_ktime(ts);
 		if (cmd == FUTEX_WAIT)
 			t = ktime_add_safe(ktime_get(), t);
+		else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME))
+			t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
 		tp = &t;
 	}
 	/*
@@ -3982,7 +3835,7 @@
 	struct compat_robust_list_head __user *head = curr->compat_robust_list;
 	struct robust_list __user *entry, *next_entry, *pending;
 	unsigned int limit = ROBUST_LIST_LIMIT, pi, pip;
-	unsigned int uninitialized_var(next_pi);
+	unsigned int next_pi;
 	compat_uptr_t uentry, next_uentry, upending;
 	compat_long_t futex_offset;
 	int rc;
@@ -4124,6 +3977,8 @@
 		t = timespec64_to_ktime(ts);
 		if (cmd == FUTEX_WAIT)
 			t = ktime_add_safe(ktime_get(), t);
+		else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME))
+			t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
 		tp = &t;
 	}
 	if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index 3941a9c..3110c77 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -6,7 +6,7 @@
 	depends on DEBUG_FS
 	select CONSTRUCTORS if !UML
 	default n
-	---help---
+	help
 	This option enables gcov-based code profiling (e.g. for code coverage
 	measurements).
 
@@ -42,7 +42,7 @@
 	depends on GCOV_KERNEL
 	depends on ARCH_HAS_GCOV_PROFILE_ALL
 	default n
-	---help---
+	help
 	This options activates profiling for the entire kernel.
 
 	If unsure, say N.
@@ -51,28 +51,4 @@
 	larger and run slower. Also be sure to exclude files from profiling
 	which are not linked to the kernel image to prevent linker errors.
 
-choice
-	prompt "Specify GCOV format"
-	depends on GCOV_KERNEL
-	depends on CC_IS_GCC
-	---help---
-	The gcov format is usually determined by the GCC version, and the
-	default is chosen according to your GCC version. However, there are
-	exceptions where format changes are integrated in lower-version GCCs.
-	In such a case, change this option to adjust the format used in the
-	kernel accordingly.
-
-config GCOV_FORMAT_3_4
-	bool "GCC 3.4 format"
-	depends on GCC_VERSION < 40700
-	---help---
-	Select this option to use the format defined by GCC 3.4.
-
-config GCOV_FORMAT_4_7
-	bool "GCC 4.7 format"
-	---help---
-	Select this option to use the format defined by GCC 4.7.
-
-endchoice
-
 endmenu
diff --git a/kernel/gcov/Makefile b/kernel/gcov/Makefile
index d66a74b..16f8ecc 100644
--- a/kernel/gcov/Makefile
+++ b/kernel/gcov/Makefile
@@ -2,6 +2,5 @@
 ccflags-y := -DSRCTREE='"$(srctree)"' -DOBJTREE='"$(objtree)"'
 
 obj-y := base.o fs.o
-obj-$(CONFIG_GCOV_FORMAT_3_4) += gcc_base.o gcc_3_4.o
-obj-$(CONFIG_GCOV_FORMAT_4_7) += gcc_base.o gcc_4_7.o
+obj-$(CONFIG_CC_IS_GCC) += gcc_base.o gcc_4_7.o
 obj-$(CONFIG_CC_IS_CLANG) += clang.o
diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c
index cc4ee48..82babf5 100644
--- a/kernel/gcov/fs.c
+++ b/kernel/gcov/fs.c
@@ -58,7 +58,7 @@
 	struct dentry *dentry;
 	struct dentry **links;
 	int num_loaded;
-	char name[0];
+	char name[];
 };
 
 static const char objtree[] = OBJTREE;
diff --git a/kernel/gcov/gcc_3_4.c b/kernel/gcov/gcc_3_4.c
deleted file mode 100644
index 801ee4b..0000000
--- a/kernel/gcov/gcc_3_4.c
+++ /dev/null
@@ -1,573 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- *  This code provides functions to handle gcc's profiling data format
- *  introduced with gcc 3.4. Future versions of gcc may change the gcov
- *  format (as happened before), so all format-specific information needs
- *  to be kept modular and easily exchangeable.
- *
- *  This file is based on gcc-internal definitions. Functions and data
- *  structures are defined to be compatible with gcc counterparts.
- *  For a better understanding, refer to gcc source: gcc/gcov-io.h.
- *
- *    Copyright IBM Corp. 2009
- *    Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
- *
- *    Uses gcc-internal data definitions.
- */
-
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <linux/seq_file.h>
-#include <linux/vmalloc.h>
-#include "gcov.h"
-
-#define GCOV_COUNTERS		5
-
-static struct gcov_info *gcov_info_head;
-
-/**
- * struct gcov_fn_info - profiling meta data per function
- * @ident: object file-unique function identifier
- * @checksum: function checksum
- * @n_ctrs: number of values per counter type belonging to this function
- *
- * This data is generated by gcc during compilation and doesn't change
- * at run-time.
- */
-struct gcov_fn_info {
-	unsigned int ident;
-	unsigned int checksum;
-	unsigned int n_ctrs[0];
-};
-
-/**
- * struct gcov_ctr_info - profiling data per counter type
- * @num: number of counter values for this type
- * @values: array of counter values for this type
- * @merge: merge function for counter values of this type (unused)
- *
- * This data is generated by gcc during compilation and doesn't change
- * at run-time with the exception of the values array.
- */
-struct gcov_ctr_info {
-	unsigned int	num;
-	gcov_type	*values;
-	void		(*merge)(gcov_type *, unsigned int);
-};
-
-/**
- * struct gcov_info - profiling data per object file
- * @version: gcov version magic indicating the gcc version used for compilation
- * @next: list head for a singly-linked list
- * @stamp: time stamp
- * @filename: name of the associated gcov data file
- * @n_functions: number of instrumented functions
- * @functions: function data
- * @ctr_mask: mask specifying which counter types are active
- * @counts: counter data per counter type
- *
- * This data is generated by gcc during compilation and doesn't change
- * at run-time with the exception of the next pointer.
- */
-struct gcov_info {
-	unsigned int			version;
-	struct gcov_info		*next;
-	unsigned int			stamp;
-	const char			*filename;
-	unsigned int			n_functions;
-	const struct gcov_fn_info	*functions;
-	unsigned int			ctr_mask;
-	struct gcov_ctr_info		counts[0];
-};
-
-/**
- * gcov_info_filename - return info filename
- * @info: profiling data set
- */
-const char *gcov_info_filename(struct gcov_info *info)
-{
-	return info->filename;
-}
-
-/**
- * gcov_info_version - return info version
- * @info: profiling data set
- */
-unsigned int gcov_info_version(struct gcov_info *info)
-{
-	return info->version;
-}
-
-/**
- * gcov_info_next - return next profiling data set
- * @info: profiling data set
- *
- * Returns next gcov_info following @info or first gcov_info in the chain if
- * @info is %NULL.
- */
-struct gcov_info *gcov_info_next(struct gcov_info *info)
-{
-	if (!info)
-		return gcov_info_head;
-
-	return info->next;
-}
-
-/**
- * gcov_info_link - link/add profiling data set to the list
- * @info: profiling data set
- */
-void gcov_info_link(struct gcov_info *info)
-{
-	info->next = gcov_info_head;
-	gcov_info_head = info;
-}
-
-/**
- * gcov_info_unlink - unlink/remove profiling data set from the list
- * @prev: previous profiling data set
- * @info: profiling data set
- */
-void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
-{
-	if (prev)
-		prev->next = info->next;
-	else
-		gcov_info_head = info->next;
-}
-
-/**
- * gcov_info_within_module - check if a profiling data set belongs to a module
- * @info: profiling data set
- * @mod: module
- *
- * Returns true if profiling data belongs module, false otherwise.
- */
-bool gcov_info_within_module(struct gcov_info *info, struct module *mod)
-{
-	return within_module((unsigned long)info, mod);
-}
-
-/* Symbolic links to be created for each profiling data file. */
-const struct gcov_link gcov_link[] = {
-	{ OBJ_TREE, "gcno" },	/* Link to .gcno file in $(objtree). */
-	{ 0, NULL},
-};
-
-/*
- * Determine whether a counter is active. Based on gcc magic. Doesn't change
- * at run-time.
- */
-static int counter_active(struct gcov_info *info, unsigned int type)
-{
-	return (1 << type) & info->ctr_mask;
-}
-
-/* Determine number of active counters. Based on gcc magic. */
-static unsigned int num_counter_active(struct gcov_info *info)
-{
-	unsigned int i;
-	unsigned int result = 0;
-
-	for (i = 0; i < GCOV_COUNTERS; i++) {
-		if (counter_active(info, i))
-			result++;
-	}
-	return result;
-}
-
-/**
- * gcov_info_reset - reset profiling data to zero
- * @info: profiling data set
- */
-void gcov_info_reset(struct gcov_info *info)
-{
-	unsigned int active = num_counter_active(info);
-	unsigned int i;
-
-	for (i = 0; i < active; i++) {
-		memset(info->counts[i].values, 0,
-		       info->counts[i].num * sizeof(gcov_type));
-	}
-}
-
-/**
- * gcov_info_is_compatible - check if profiling data can be added
- * @info1: first profiling data set
- * @info2: second profiling data set
- *
- * Returns non-zero if profiling data can be added, zero otherwise.
- */
-int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2)
-{
-	return (info1->stamp == info2->stamp);
-}
-
-/**
- * gcov_info_add - add up profiling data
- * @dest: profiling data set to which data is added
- * @source: profiling data set which is added
- *
- * Adds profiling counts of @source to @dest.
- */
-void gcov_info_add(struct gcov_info *dest, struct gcov_info *source)
-{
-	unsigned int i;
-	unsigned int j;
-
-	for (i = 0; i < num_counter_active(dest); i++) {
-		for (j = 0; j < dest->counts[i].num; j++) {
-			dest->counts[i].values[j] +=
-				source->counts[i].values[j];
-		}
-	}
-}
-
-/* Get size of function info entry. Based on gcc magic. */
-static size_t get_fn_size(struct gcov_info *info)
-{
-	size_t size;
-
-	size = sizeof(struct gcov_fn_info) + num_counter_active(info) *
-	       sizeof(unsigned int);
-	if (__alignof__(struct gcov_fn_info) > sizeof(unsigned int))
-		size = ALIGN(size, __alignof__(struct gcov_fn_info));
-	return size;
-}
-
-/* Get address of function info entry. Based on gcc magic. */
-static struct gcov_fn_info *get_fn_info(struct gcov_info *info, unsigned int fn)
-{
-	return (struct gcov_fn_info *)
-		((char *) info->functions + fn * get_fn_size(info));
-}
-
-/**
- * gcov_info_dup - duplicate profiling data set
- * @info: profiling data set to duplicate
- *
- * Return newly allocated duplicate on success, %NULL on error.
- */
-struct gcov_info *gcov_info_dup(struct gcov_info *info)
-{
-	struct gcov_info *dup;
-	unsigned int i;
-	unsigned int active;
-
-	/* Duplicate gcov_info. */
-	active = num_counter_active(info);
-	dup = kzalloc(struct_size(dup, counts, active), GFP_KERNEL);
-	if (!dup)
-		return NULL;
-	dup->version		= info->version;
-	dup->stamp		= info->stamp;
-	dup->n_functions	= info->n_functions;
-	dup->ctr_mask		= info->ctr_mask;
-	/* Duplicate filename. */
-	dup->filename		= kstrdup(info->filename, GFP_KERNEL);
-	if (!dup->filename)
-		goto err_free;
-	/* Duplicate table of functions. */
-	dup->functions = kmemdup(info->functions, info->n_functions *
-				 get_fn_size(info), GFP_KERNEL);
-	if (!dup->functions)
-		goto err_free;
-	/* Duplicate counter arrays. */
-	for (i = 0; i < active ; i++) {
-		struct gcov_ctr_info *ctr = &info->counts[i];
-		size_t size = ctr->num * sizeof(gcov_type);
-
-		dup->counts[i].num = ctr->num;
-		dup->counts[i].merge = ctr->merge;
-		dup->counts[i].values = vmalloc(size);
-		if (!dup->counts[i].values)
-			goto err_free;
-		memcpy(dup->counts[i].values, ctr->values, size);
-	}
-	return dup;
-
-err_free:
-	gcov_info_free(dup);
-	return NULL;
-}
-
-/**
- * gcov_info_free - release memory for profiling data set duplicate
- * @info: profiling data set duplicate to free
- */
-void gcov_info_free(struct gcov_info *info)
-{
-	unsigned int active = num_counter_active(info);
-	unsigned int i;
-
-	for (i = 0; i < active ; i++)
-		vfree(info->counts[i].values);
-	kfree(info->functions);
-	kfree(info->filename);
-	kfree(info);
-}
-
-/**
- * struct type_info - iterator helper array
- * @ctr_type: counter type
- * @offset: index of the first value of the current function for this type
- *
- * This array is needed to convert the in-memory data format into the in-file
- * data format:
- *
- * In-memory:
- *   for each counter type
- *     for each function
- *       values
- *
- * In-file:
- *   for each function
- *     for each counter type
- *       values
- *
- * See gcc source gcc/gcov-io.h for more information on data organization.
- */
-struct type_info {
-	int ctr_type;
-	unsigned int offset;
-};
-
-/**
- * struct gcov_iterator - specifies current file position in logical records
- * @info: associated profiling data
- * @record: record type
- * @function: function number
- * @type: counter type
- * @count: index into values array
- * @num_types: number of counter types
- * @type_info: helper array to get values-array offset for current function
- */
-struct gcov_iterator {
-	struct gcov_info *info;
-
-	int record;
-	unsigned int function;
-	unsigned int type;
-	unsigned int count;
-
-	int num_types;
-	struct type_info type_info[0];
-};
-
-static struct gcov_fn_info *get_func(struct gcov_iterator *iter)
-{
-	return get_fn_info(iter->info, iter->function);
-}
-
-static struct type_info *get_type(struct gcov_iterator *iter)
-{
-	return &iter->type_info[iter->type];
-}
-
-/**
- * gcov_iter_new - allocate and initialize profiling data iterator
- * @info: profiling data set to be iterated
- *
- * Return file iterator on success, %NULL otherwise.
- */
-struct gcov_iterator *gcov_iter_new(struct gcov_info *info)
-{
-	struct gcov_iterator *iter;
-
-	iter = kzalloc(struct_size(iter, type_info, num_counter_active(info)),
-		       GFP_KERNEL);
-	if (iter)
-		iter->info = info;
-
-	return iter;
-}
-
-/**
- * gcov_iter_free - release memory for iterator
- * @iter: file iterator to free
- */
-void gcov_iter_free(struct gcov_iterator *iter)
-{
-	kfree(iter);
-}
-
-/**
- * gcov_iter_get_info - return profiling data set for given file iterator
- * @iter: file iterator
- */
-struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter)
-{
-	return iter->info;
-}
-
-/**
- * gcov_iter_start - reset file iterator to starting position
- * @iter: file iterator
- */
-void gcov_iter_start(struct gcov_iterator *iter)
-{
-	int i;
-
-	iter->record = 0;
-	iter->function = 0;
-	iter->type = 0;
-	iter->count = 0;
-	iter->num_types = 0;
-	for (i = 0; i < GCOV_COUNTERS; i++) {
-		if (counter_active(iter->info, i)) {
-			iter->type_info[iter->num_types].ctr_type = i;
-			iter->type_info[iter->num_types++].offset = 0;
-		}
-	}
-}
-
-/* Mapping of logical record number to actual file content. */
-#define RECORD_FILE_MAGIC	0
-#define RECORD_GCOV_VERSION	1
-#define RECORD_TIME_STAMP	2
-#define RECORD_FUNCTION_TAG	3
-#define RECORD_FUNCTON_TAG_LEN	4
-#define RECORD_FUNCTION_IDENT	5
-#define RECORD_FUNCTION_CHECK	6
-#define RECORD_COUNT_TAG	7
-#define RECORD_COUNT_LEN	8
-#define RECORD_COUNT		9
-
-/**
- * gcov_iter_next - advance file iterator to next logical record
- * @iter: file iterator
- *
- * Return zero if new position is valid, non-zero if iterator has reached end.
- */
-int gcov_iter_next(struct gcov_iterator *iter)
-{
-	switch (iter->record) {
-	case RECORD_FILE_MAGIC:
-	case RECORD_GCOV_VERSION:
-	case RECORD_FUNCTION_TAG:
-	case RECORD_FUNCTON_TAG_LEN:
-	case RECORD_FUNCTION_IDENT:
-	case RECORD_COUNT_TAG:
-		/* Advance to next record */
-		iter->record++;
-		break;
-	case RECORD_COUNT:
-		/* Advance to next count */
-		iter->count++;
-		/* fall through */
-	case RECORD_COUNT_LEN:
-		if (iter->count < get_func(iter)->n_ctrs[iter->type]) {
-			iter->record = 9;
-			break;
-		}
-		/* Advance to next counter type */
-		get_type(iter)->offset += iter->count;
-		iter->count = 0;
-		iter->type++;
-		/* fall through */
-	case RECORD_FUNCTION_CHECK:
-		if (iter->type < iter->num_types) {
-			iter->record = 7;
-			break;
-		}
-		/* Advance to next function */
-		iter->type = 0;
-		iter->function++;
-		/* fall through */
-	case RECORD_TIME_STAMP:
-		if (iter->function < iter->info->n_functions)
-			iter->record = 3;
-		else
-			iter->record = -1;
-		break;
-	}
-	/* Check for EOF. */
-	if (iter->record == -1)
-		return -EINVAL;
-	else
-		return 0;
-}
-
-/**
- * seq_write_gcov_u32 - write 32 bit number in gcov format to seq_file
- * @seq: seq_file handle
- * @v: value to be stored
- *
- * Number format defined by gcc: numbers are recorded in the 32 bit
- * unsigned binary form of the endianness of the machine generating the
- * file.
- */
-static int seq_write_gcov_u32(struct seq_file *seq, u32 v)
-{
-	return seq_write(seq, &v, sizeof(v));
-}
-
-/**
- * seq_write_gcov_u64 - write 64 bit number in gcov format to seq_file
- * @seq: seq_file handle
- * @v: value to be stored
- *
- * Number format defined by gcc: numbers are recorded in the 32 bit
- * unsigned binary form of the endianness of the machine generating the
- * file. 64 bit numbers are stored as two 32 bit numbers, the low part
- * first.
- */
-static int seq_write_gcov_u64(struct seq_file *seq, u64 v)
-{
-	u32 data[2];
-
-	data[0] = (v & 0xffffffffUL);
-	data[1] = (v >> 32);
-	return seq_write(seq, data, sizeof(data));
-}
-
-/**
- * gcov_iter_write - write data for current pos to seq_file
- * @iter: file iterator
- * @seq: seq_file handle
- *
- * Return zero on success, non-zero otherwise.
- */
-int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq)
-{
-	int rc = -EINVAL;
-
-	switch (iter->record) {
-	case RECORD_FILE_MAGIC:
-		rc = seq_write_gcov_u32(seq, GCOV_DATA_MAGIC);
-		break;
-	case RECORD_GCOV_VERSION:
-		rc = seq_write_gcov_u32(seq, iter->info->version);
-		break;
-	case RECORD_TIME_STAMP:
-		rc = seq_write_gcov_u32(seq, iter->info->stamp);
-		break;
-	case RECORD_FUNCTION_TAG:
-		rc = seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION);
-		break;
-	case RECORD_FUNCTON_TAG_LEN:
-		rc = seq_write_gcov_u32(seq, 2);
-		break;
-	case RECORD_FUNCTION_IDENT:
-		rc = seq_write_gcov_u32(seq, get_func(iter)->ident);
-		break;
-	case RECORD_FUNCTION_CHECK:
-		rc = seq_write_gcov_u32(seq, get_func(iter)->checksum);
-		break;
-	case RECORD_COUNT_TAG:
-		rc = seq_write_gcov_u32(seq,
-			GCOV_TAG_FOR_COUNTER(get_type(iter)->ctr_type));
-		break;
-	case RECORD_COUNT_LEN:
-		rc = seq_write_gcov_u32(seq,
-				get_func(iter)->n_ctrs[iter->type] * 2);
-		break;
-	case RECORD_COUNT:
-		rc = seq_write_gcov_u64(seq,
-			iter->info->counts[iter->type].
-				values[iter->count + get_type(iter)->offset]);
-		break;
-	}
-	return rc;
-}
diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c
index 60c7be5..53c67c8 100644
--- a/kernel/gcov/gcc_4_7.c
+++ b/kernel/gcov/gcc_4_7.c
@@ -70,7 +70,7 @@
 	unsigned int ident;
 	unsigned int lineno_checksum;
 	unsigned int cfg_checksum;
-	struct gcov_ctr_info ctrs[0];
+	struct gcov_ctr_info ctrs[];
 };
 
 /**
diff --git a/kernel/groups.c b/kernel/groups.c
index daae2f2..fe7e638 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -20,7 +20,7 @@
 	len = sizeof(struct group_info) + sizeof(kgid_t) * gidsetsize;
 	gi = kmalloc(len, GFP_KERNEL_ACCOUNT|__GFP_NOWARN|__GFP_NORETRY);
 	if (!gi)
-		gi = __vmalloc(len, GFP_KERNEL_ACCOUNT, PAGE_KERNEL);
+		gi = __vmalloc(len, GFP_KERNEL_ACCOUNT);
 	if (!gi)
 		return NULL;
 
@@ -178,7 +178,7 @@
 {
 	struct user_namespace *user_ns = current_user_ns();
 
-	return ns_capable(user_ns, CAP_SETGID) &&
+	return ns_capable_setid(user_ns, CAP_SETGID) &&
 		userns_may_setgroups(user_ns);
 }
 
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 14a625c..396ebae 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -53,9 +53,18 @@
 static int __read_mostly did_panic;
 static bool hung_task_show_lock;
 static bool hung_task_call_panic;
+static bool hung_task_show_all_bt;
 
 static struct task_struct *watchdog_task;
 
+#ifdef CONFIG_SMP
+/*
+ * Should we dump all CPUs backtraces in a hung task event?
+ * Defaults to 0, can be changed via sysctl.
+ */
+unsigned int __read_mostly sysctl_hung_task_all_cpu_backtrace;
+#endif /* CONFIG_SMP */
+
 /*
  * Should we panic (and reboot, if panic_timeout= is set) when a
  * hung task is detected:
@@ -63,16 +72,6 @@
 unsigned int __read_mostly sysctl_hung_task_panic =
 				CONFIG_BOOTPARAM_HUNG_TASK_PANIC_VALUE;
 
-static int __init hung_task_panic_setup(char *str)
-{
-	int rc = kstrtouint(str, 0, &sysctl_hung_task_panic);
-
-	if (rc)
-		return rc;
-	return 1;
-}
-__setup("hung_task_panic=", hung_task_panic_setup);
-
 static int
 hung_task_panic(struct notifier_block *this, unsigned long event, void *ptr)
 {
@@ -137,6 +136,9 @@
 			" disables this message.\n");
 		sched_show_task(t);
 		hung_task_show_lock = true;
+
+		if (sysctl_hung_task_all_cpu_backtrace)
+			hung_task_show_all_bt = true;
 	}
 
 	touch_nmi_watchdog();
@@ -201,10 +203,14 @@
 	rcu_read_unlock();
 	if (hung_task_show_lock)
 		debug_show_all_locks();
-	if (hung_task_call_panic) {
+
+	if (hung_task_show_all_bt) {
+		hung_task_show_all_bt = false;
 		trigger_all_cpu_backtrace();
-		panic("hung_task: blocked tasks");
 	}
+
+	if (hung_task_call_panic)
+		panic("hung_task: blocked tasks");
 }
 
 static long hung_timeout_jiffies(unsigned long last_checked,
@@ -219,8 +225,7 @@
  * Process updating of timeout sysctl
  */
 int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
-				  void __user *buffer,
-				  size_t *lenp, loff_t *ppos)
+				  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 4e11120..164a031 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -43,14 +43,14 @@
 config AUTO_IRQ_AFFINITY
        bool
 
+# Interrupt injection mechanism
+config GENERIC_IRQ_INJECTION
+	bool
+
 # Tasklet based software resend for pending interrupts on enable_irq()
 config HARDIRQS_SW_RESEND
        bool
 
-# Preflow handler support for fasteoi (sparc64)
-config IRQ_PREFLOW_FASTEOI
-       bool
-
 # Edge style eoi based handler (cell)
 config IRQ_EDGE_EOI_HANDLER
        bool
@@ -68,6 +68,7 @@
 config IRQ_SIM
 	bool
 	select IRQ_WORK
+	select IRQ_DOMAIN
 
 # Support for hierarchical irq domains
 config IRQ_DOMAIN_HIERARCHY
@@ -114,7 +115,7 @@
 
 config SPARSE_IRQ
 	bool "Support sparse irq numbering" if MAY_HAVE_SPARSE_IRQ
-	---help---
+	help
 
 	  Sparse irq numbering is useful for distro kernels that want
 	  to define a high CONFIG_NR_CPUS value but still want to have
@@ -128,8 +129,9 @@
 config GENERIC_IRQ_DEBUGFS
 	bool "Expose irq internals in debugfs"
 	depends on DEBUG_FS
+	select GENERIC_IRQ_INJECTION
 	default n
-	---help---
+	help
 
 	  Exposes internal state information through debugfs. Mostly for
 	  developers and debugging of hard to diagnose interrupt problems.
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 856f029..0b70811 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -281,7 +281,7 @@
 		}
 	}
 	if (resend)
-		check_irq_resend(desc);
+		check_irq_resend(desc, false);
 
 	return ret;
 }
@@ -659,16 +659,6 @@
 }
 EXPORT_SYMBOL_GPL(handle_level_irq);
 
-#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
-static inline void preflow_handler(struct irq_desc *desc)
-{
-	if (desc->preflow_handler)
-		desc->preflow_handler(&desc->irq_data);
-}
-#else
-static inline void preflow_handler(struct irq_desc *desc) { }
-#endif
-
 static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
 {
 	if (!(desc->istate & IRQS_ONESHOT)) {
@@ -724,7 +714,6 @@
 	if (desc->istate & IRQS_ONESHOT)
 		mask_irq(desc);
 
-	preflow_handler(desc);
 	handle_irq_event(desc);
 
 	cond_unmask_eoi_irq(desc, chip);
@@ -959,6 +948,33 @@
 }
 
 /**
+ * handle_percpu_devid_fasteoi_ipi - Per CPU local IPI handler with per cpu
+ *				     dev ids
+ * @desc:	the interrupt description structure for this irq
+ *
+ * The biggest difference with the IRQ version is that the interrupt is
+ * EOIed early, as the IPI could result in a context switch, and we need to
+ * make sure the IPI can fire again. We also assume that the arch code has
+ * registered an action. If not, we are positively doomed.
+ */
+void handle_percpu_devid_fasteoi_ipi(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct irqaction *action = desc->action;
+	unsigned int irq = irq_desc_get_irq(desc);
+	irqreturn_t res;
+
+	__kstat_incr_irqs_this_cpu(desc);
+
+	if (chip->irq_eoi)
+		chip->irq_eoi(&desc->irq_data);
+
+	trace_irq_handler_entry(irq, action);
+	res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
+	trace_irq_handler_exit(irq, action, res);
+}
+
+/**
  * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu
  *				     dev ids
  * @desc:	the interrupt description structure for this irq
@@ -1234,7 +1250,6 @@
 	/* Start handling the irq */
 	desc->irq_data.chip->irq_ack(&desc->irq_data);
 
-	preflow_handler(desc);
 	handle_irq_event(desc);
 
 	cond_unmask_eoi_irq(desc, chip);
@@ -1284,7 +1299,6 @@
 	if (desc->istate & IRQS_ONESHOT)
 		mask_irq(desc);
 
-	preflow_handler(desc);
 	handle_irq_event(desc);
 
 	cond_unmask_eoi_irq(desc, chip);
@@ -1301,6 +1315,50 @@
 #endif /* CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS */
 
 /**
+ * irq_chip_set_parent_state - set the state of a parent interrupt.
+ *
+ * @data: Pointer to interrupt specific data
+ * @which: State to be restored (one of IRQCHIP_STATE_*)
+ * @val: Value corresponding to @which
+ *
+ * Conditional success, if the underlying irqchip does not implement it.
+ */
+int irq_chip_set_parent_state(struct irq_data *data,
+			      enum irqchip_irq_state which,
+			      bool val)
+{
+	data = data->parent_data;
+
+	if (!data || !data->chip->irq_set_irqchip_state)
+		return 0;
+
+	return data->chip->irq_set_irqchip_state(data, which, val);
+}
+EXPORT_SYMBOL_GPL(irq_chip_set_parent_state);
+
+/**
+ * irq_chip_get_parent_state - get the state of a parent interrupt.
+ *
+ * @data: Pointer to interrupt specific data
+ * @which: one of IRQCHIP_STATE_* the caller wants to know
+ * @state: a pointer to a boolean where the state is to be stored
+ *
+ * Conditional success, if the underlying irqchip does not implement it.
+ */
+int irq_chip_get_parent_state(struct irq_data *data,
+			      enum irqchip_irq_state which,
+			      bool *state)
+{
+	data = data->parent_data;
+
+	if (!data || !data->chip->irq_get_irqchip_state)
+		return 0;
+
+	return data->chip->irq_get_irqchip_state(data, which, state);
+}
+EXPORT_SYMBOL_GPL(irq_chip_get_parent_state);
+
+/**
  * irq_chip_enable_parent - Enable the parent interrupt (defaults to unmask if
  * NULL)
  * @data:	Pointer to interrupt specific data
@@ -1437,6 +1495,7 @@
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(irq_chip_retrigger_hierarchy);
 
 /**
  * irq_chip_set_vcpu_affinity_parent - Set vcpu affinity on the parent interrupt
@@ -1451,7 +1510,7 @@
 
 	return -ENOSYS;
 }
-
+EXPORT_SYMBOL_GPL(irq_chip_set_vcpu_affinity_parent);
 /**
  * irq_chip_set_wake_parent - Set/reset wake-up on the parent interrupt
  * @data:	Pointer to interrupt specific data
@@ -1512,18 +1571,17 @@
  */
 int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 {
-	struct irq_data *pos = NULL;
+	struct irq_data *pos;
 
-#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
-	for (; data; data = data->parent_data)
-#endif
+	for (pos = NULL; !pos && data; data = irqd_get_parent_data(data)) {
 		if (data->chip && data->chip->irq_compose_msi_msg)
 			pos = data;
+	}
+
 	if (!pos)
 		return -ENOSYS;
 
 	pos->chip->irq_compose_msi_msg(pos, msg);
-
 	return 0;
 }
 
diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c
index 6c7ca2e..02236b1 100644
--- a/kernel/irq/cpuhotplug.c
+++ b/kernel/irq/cpuhotplug.c
@@ -12,6 +12,7 @@
 #include <linux/interrupt.h>
 #include <linux/ratelimit.h>
 #include <linux/irq.h>
+#include <linux/sched/isolation.h>
 
 #include "internals.h"
 
@@ -171,6 +172,20 @@
 	}
 }
 
+static bool hk_should_isolate(struct irq_data *data, unsigned int cpu)
+{
+	const struct cpumask *hk_mask;
+
+	if (!housekeeping_enabled(HK_FLAG_MANAGED_IRQ))
+		return false;
+
+	hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
+	if (cpumask_subset(irq_data_get_effective_affinity_mask(data), hk_mask))
+		return false;
+
+	return cpumask_test_cpu(cpu, hk_mask);
+}
+
 static void irq_restore_affinity_of_irq(struct irq_desc *desc, unsigned int cpu)
 {
 	struct irq_data *data = irq_desc_get_irq_data(desc);
@@ -188,9 +203,11 @@
 	/*
 	 * If the interrupt can only be directed to a single target
 	 * CPU then it is already assigned to a CPU in the affinity
-	 * mask. No point in trying to move it around.
+	 * mask. No point in trying to move it around unless the
+	 * isolation mechanism requests to move it to an upcoming
+	 * housekeeping CPU.
 	 */
-	if (!irqd_is_single_target(data))
+	if (!irqd_is_single_target(data) || hk_should_isolate(data, cpu))
 		irq_set_affinity_locked(data, affinity, false);
 }
 
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
index d44c8fd..e4cff35 100644
--- a/kernel/irq/debugfs.c
+++ b/kernel/irq/debugfs.c
@@ -57,6 +57,7 @@
 	BIT_MASK_DESCR(IRQCHIP_EOI_THREADED),
 	BIT_MASK_DESCR(IRQCHIP_SUPPORTS_LEVEL_MSI),
 	BIT_MASK_DESCR(IRQCHIP_SUPPORTS_NMI),
+	BIT_MASK_DESCR(IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND),
 };
 
 static void
@@ -112,6 +113,7 @@
 	BIT_MASK_DESCR(IRQD_AFFINITY_SET),
 	BIT_MASK_DESCR(IRQD_SETAFFINITY_PENDING),
 	BIT_MASK_DESCR(IRQD_AFFINITY_MANAGED),
+	BIT_MASK_DESCR(IRQD_AFFINITY_ON_ACTIVATE),
 	BIT_MASK_DESCR(IRQD_MANAGED_SHUTDOWN),
 	BIT_MASK_DESCR(IRQD_CAN_RESERVE),
 	BIT_MASK_DESCR(IRQD_MSI_NOMASK_QUIRK),
@@ -120,6 +122,12 @@
 
 	BIT_MASK_DESCR(IRQD_WAKEUP_STATE),
 	BIT_MASK_DESCR(IRQD_WAKEUP_ARMED),
+
+	BIT_MASK_DESCR(IRQD_DEFAULT_TRIGGER_SET),
+
+	BIT_MASK_DESCR(IRQD_HANDLE_ENFORCE_IRQCTX),
+
+	BIT_MASK_DESCR(IRQD_IRQ_ENABLED_ON_SUSPEND),
 };
 
 static const struct irq_bit_descr irqdesc_states[] = {
@@ -131,6 +139,7 @@
 	BIT_MASK_DESCR(_IRQ_PER_CPU_DEVID),
 	BIT_MASK_DESCR(_IRQ_IS_POLLED),
 	BIT_MASK_DESCR(_IRQ_DISABLE_UNLAZY),
+	BIT_MASK_DESCR(_IRQ_HIDDEN),
 };
 
 static const struct irq_bit_descr irqdesc_istates[] = {
@@ -190,40 +199,7 @@
 		return -EFAULT;
 
 	if (!strncmp(buf, "trigger", size)) {
-		unsigned long flags;
-		int err;
-
-		/* Try the HW interface first */
-		err = irq_set_irqchip_state(irq_desc_get_irq(desc),
-					    IRQCHIP_STATE_PENDING, true);
-		if (!err)
-			return count;
-
-		/*
-		 * Otherwise, try to inject via the resend interface,
-		 * which may or may not succeed.
-		 */
-		chip_bus_lock(desc);
-		raw_spin_lock_irqsave(&desc->lock, flags);
-
-		/*
-		 * Don't allow injection when the interrupt is:
-		 *  - Level or NMI type
-		 *  - not activated
-		 *  - replaying already
-		 */
-		if (irq_settings_is_level(desc) ||
-		    !irqd_is_activated(&desc->irq_data) ||
-		    (desc->istate & (IRQS_NMI | IRQS_REPLAY))) {
-			err = -EINVAL;
-		} else {
-			desc->istate |= IRQS_PENDING;
-			check_irq_resend(desc);
-			err = 0;
-		}
-
-		raw_spin_unlock_irqrestore(&desc->lock, flags);
-		chip_bus_sync_unlock(desc);
+		int err = irq_inject_interrupt(irq_desc_get_irq(desc));
 
 		return err ? err : count;
 	}
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index a4ace61..762a928 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -145,6 +145,13 @@
 	for_each_action_of_desc(desc, action) {
 		irqreturn_t res;
 
+		/*
+		 * If this IRQ would be threaded under force_irqthreads, mark it so.
+		 */
+		if (irq_settings_can_thread(desc) &&
+		    !(action->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)))
+			lockdep_hardirq_threaded();
+
 		trace_irq_handler_entry(irq, action);
 		res = action->handler(irq, action->dev_id);
 		trace_irq_handler_exit(irq, action, res);
@@ -166,7 +173,7 @@
 
 			__irq_wake_thread(desc, action);
 
-			/* Fall through - to add to randomness */
+			fallthrough;	/* to add to randomness */
 		case IRQ_HANDLED:
 			*flags |= action->flags;
 			break;
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index c9d8eb7..5436352 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -108,7 +108,7 @@
 irqreturn_t handle_irq_event(struct irq_desc *desc);
 
 /* Resending of interrupts :*/
-void check_irq_resend(struct irq_desc *desc);
+int check_irq_resend(struct irq_desc *desc, bool inject);
 bool irq_wait_for_poll(struct irq_desc *desc);
 void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action);
 
@@ -425,6 +425,10 @@
 {
 	return desc->pending_mask;
 }
+static inline bool handle_enforce_irqctx(struct irq_data *data)
+{
+	return irqd_is_handle_enforce_irqctx(data);
+}
 bool irq_fixup_move_pending(struct irq_desc *desc, bool force_clear);
 #else /* CONFIG_GENERIC_PENDING_IRQ */
 static inline bool irq_can_move_pcntxt(struct irq_data *data)
@@ -451,6 +455,10 @@
 {
 	return false;
 }
+static inline bool handle_enforce_irqctx(struct irq_data *data)
+{
+	return false;
+}
 #endif /* !CONFIG_GENERIC_PENDING_IRQ */
 
 #if !defined(CONFIG_IRQ_DOMAIN) || !defined(CONFIG_IRQ_DOMAIN_HIERARCHY)
@@ -465,6 +473,15 @@
 }
 #endif
 
+static inline struct irq_data *irqd_get_parent_data(struct irq_data *irqd)
+{
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+	return irqd->parent_data;
+#else
+	return NULL;
+#endif
+}
+
 #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
 #include <linux/debugfs.h>
 
diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
index b992f88..4800660 100644
--- a/kernel/irq/irq_sim.c
+++ b/kernel/irq/irq_sim.c
@@ -1,14 +1,31 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl>
+ * Copyright (C) 2020 Bartosz Golaszewski <bgolaszewski@baylibre.com>
  */
 
-#include <linux/slab.h>
-#include <linux/irq_sim.h>
 #include <linux/irq.h>
+#include <linux/irq_sim.h>
+#include <linux/irq_work.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+struct irq_sim_work_ctx {
+	struct irq_work		work;
+	int			irq_base;
+	unsigned int		irq_count;
+	unsigned long		*pending;
+	struct irq_domain	*domain;
+};
+
+struct irq_sim_irq_ctx {
+	int			irqnum;
+	bool			enabled;
+	struct irq_sim_work_ctx	*work_ctx;
+};
 
 struct irq_sim_devres {
-	struct irq_sim		*sim;
+	struct irq_domain	*domain;
 };
 
 static void irq_sim_irqmask(struct irq_data *data)
@@ -36,159 +53,205 @@
 	return 0;
 }
 
+static int irq_sim_get_irqchip_state(struct irq_data *data,
+				     enum irqchip_irq_state which, bool *state)
+{
+	struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
+	irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+	switch (which) {
+	case IRQCHIP_STATE_PENDING:
+		if (irq_ctx->enabled)
+			*state = test_bit(hwirq, irq_ctx->work_ctx->pending);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int irq_sim_set_irqchip_state(struct irq_data *data,
+				     enum irqchip_irq_state which, bool state)
+{
+	struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
+	irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+	switch (which) {
+	case IRQCHIP_STATE_PENDING:
+		if (irq_ctx->enabled) {
+			assign_bit(hwirq, irq_ctx->work_ctx->pending, state);
+			if (state)
+				irq_work_queue(&irq_ctx->work_ctx->work);
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static struct irq_chip irq_sim_irqchip = {
-	.name		= "irq_sim",
-	.irq_mask	= irq_sim_irqmask,
-	.irq_unmask	= irq_sim_irqunmask,
-	.irq_set_type	= irq_sim_set_type,
+	.name			= "irq_sim",
+	.irq_mask		= irq_sim_irqmask,
+	.irq_unmask		= irq_sim_irqunmask,
+	.irq_set_type		= irq_sim_set_type,
+	.irq_get_irqchip_state	= irq_sim_get_irqchip_state,
+	.irq_set_irqchip_state	= irq_sim_set_irqchip_state,
 };
 
 static void irq_sim_handle_irq(struct irq_work *work)
 {
 	struct irq_sim_work_ctx *work_ctx;
 	unsigned int offset = 0;
-	struct irq_sim *sim;
 	int irqnum;
 
 	work_ctx = container_of(work, struct irq_sim_work_ctx, work);
-	sim = container_of(work_ctx, struct irq_sim, work_ctx);
 
-	while (!bitmap_empty(work_ctx->pending, sim->irq_count)) {
+	while (!bitmap_empty(work_ctx->pending, work_ctx->irq_count)) {
 		offset = find_next_bit(work_ctx->pending,
-				       sim->irq_count, offset);
+				       work_ctx->irq_count, offset);
 		clear_bit(offset, work_ctx->pending);
-		irqnum = irq_sim_irqnum(sim, offset);
+		irqnum = irq_find_mapping(work_ctx->domain, offset);
 		handle_simple_irq(irq_to_desc(irqnum));
 	}
 }
 
-/**
- * irq_sim_init - Initialize the interrupt simulator: allocate a range of
- *                dummy interrupts.
- *
- * @sim:        The interrupt simulator object to initialize.
- * @num_irqs:   Number of interrupts to allocate
- *
- * On success: return the base of the allocated interrupt range.
- * On failure: a negative errno.
- */
-int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs)
+static int irq_sim_domain_map(struct irq_domain *domain,
+			      unsigned int virq, irq_hw_number_t hw)
 {
-	int i;
+	struct irq_sim_work_ctx *work_ctx = domain->host_data;
+	struct irq_sim_irq_ctx *irq_ctx;
 
-	sim->irqs = kmalloc_array(num_irqs, sizeof(*sim->irqs), GFP_KERNEL);
-	if (!sim->irqs)
+	irq_ctx = kzalloc(sizeof(*irq_ctx), GFP_KERNEL);
+	if (!irq_ctx)
 		return -ENOMEM;
 
-	sim->irq_base = irq_alloc_descs(-1, 0, num_irqs, 0);
-	if (sim->irq_base < 0) {
-		kfree(sim->irqs);
-		return sim->irq_base;
-	}
+	irq_set_chip(virq, &irq_sim_irqchip);
+	irq_set_chip_data(virq, irq_ctx);
+	irq_set_handler(virq, handle_simple_irq);
+	irq_modify_status(virq, IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
+	irq_ctx->work_ctx = work_ctx;
 
-	sim->work_ctx.pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
-	if (!sim->work_ctx.pending) {
-		kfree(sim->irqs);
-		irq_free_descs(sim->irq_base, num_irqs);
-		return -ENOMEM;
-	}
-
-	for (i = 0; i < num_irqs; i++) {
-		sim->irqs[i].irqnum = sim->irq_base + i;
-		sim->irqs[i].enabled = false;
-		irq_set_chip(sim->irq_base + i, &irq_sim_irqchip);
-		irq_set_chip_data(sim->irq_base + i, &sim->irqs[i]);
-		irq_set_handler(sim->irq_base + i, &handle_simple_irq);
-		irq_modify_status(sim->irq_base + i,
-				  IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
-	}
-
-	init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq);
-	sim->irq_count = num_irqs;
-
-	return sim->irq_base;
+	return 0;
 }
-EXPORT_SYMBOL_GPL(irq_sim_init);
+
+static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq)
+{
+	struct irq_sim_irq_ctx *irq_ctx;
+	struct irq_data *irqd;
+
+	irqd = irq_domain_get_irq_data(domain, virq);
+	irq_ctx = irq_data_get_irq_chip_data(irqd);
+
+	irq_set_handler(virq, NULL);
+	irq_domain_reset_irq_data(irqd);
+	kfree(irq_ctx);
+}
+
+static const struct irq_domain_ops irq_sim_domain_ops = {
+	.map		= irq_sim_domain_map,
+	.unmap		= irq_sim_domain_unmap,
+};
 
 /**
- * irq_sim_fini - Deinitialize the interrupt simulator: free the interrupt
- *                descriptors and allocated memory.
+ * irq_domain_create_sim - Create a new interrupt simulator irq_domain and
+ *                         allocate a range of dummy interrupts.
  *
- * @sim:        The interrupt simulator to tear down.
+ * @fnode:      struct fwnode_handle to be associated with this domain.
+ * @num_irqs:   Number of interrupts to allocate.
+ *
+ * On success: return a new irq_domain object.
+ * On failure: a negative errno wrapped with ERR_PTR().
  */
-void irq_sim_fini(struct irq_sim *sim)
+struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
+					 unsigned int num_irqs)
 {
-	irq_work_sync(&sim->work_ctx.work);
-	bitmap_free(sim->work_ctx.pending);
-	irq_free_descs(sim->irq_base, sim->irq_count);
-	kfree(sim->irqs);
-}
-EXPORT_SYMBOL_GPL(irq_sim_fini);
+	struct irq_sim_work_ctx *work_ctx;
 
-static void devm_irq_sim_release(struct device *dev, void *res)
+	work_ctx = kmalloc(sizeof(*work_ctx), GFP_KERNEL);
+	if (!work_ctx)
+		goto err_out;
+
+	work_ctx->pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
+	if (!work_ctx->pending)
+		goto err_free_work_ctx;
+
+	work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs,
+						    &irq_sim_domain_ops,
+						    work_ctx);
+	if (!work_ctx->domain)
+		goto err_free_bitmap;
+
+	work_ctx->irq_count = num_irqs;
+	init_irq_work(&work_ctx->work, irq_sim_handle_irq);
+
+	return work_ctx->domain;
+
+err_free_bitmap:
+	bitmap_free(work_ctx->pending);
+err_free_work_ctx:
+	kfree(work_ctx);
+err_out:
+	return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(irq_domain_create_sim);
+
+/**
+ * irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free
+ *                         the interrupt descriptors and allocated memory.
+ *
+ * @domain:     The interrupt simulator domain to tear down.
+ */
+void irq_domain_remove_sim(struct irq_domain *domain)
+{
+	struct irq_sim_work_ctx *work_ctx = domain->host_data;
+
+	irq_work_sync(&work_ctx->work);
+	bitmap_free(work_ctx->pending);
+	kfree(work_ctx);
+
+	irq_domain_remove(domain);
+}
+EXPORT_SYMBOL_GPL(irq_domain_remove_sim);
+
+static void devm_irq_domain_release_sim(struct device *dev, void *res)
 {
 	struct irq_sim_devres *this = res;
 
-	irq_sim_fini(this->sim);
+	irq_domain_remove_sim(this->domain);
 }
 
 /**
- * irq_sim_init - Initialize the interrupt simulator for a managed device.
+ * devm_irq_domain_create_sim - Create a new interrupt simulator for
+ *                              a managed device.
  *
  * @dev:        Device to initialize the simulator object for.
- * @sim:        The interrupt simulator object to initialize.
+ * @fnode:      struct fwnode_handle to be associated with this domain.
  * @num_irqs:   Number of interrupts to allocate
  *
- * On success: return the base of the allocated interrupt range.
- * On failure: a negative errno.
+ * On success: return a new irq_domain object.
+ * On failure: a negative errno wrapped with ERR_PTR().
  */
-int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
-		      unsigned int num_irqs)
+struct irq_domain *devm_irq_domain_create_sim(struct device *dev,
+					      struct fwnode_handle *fwnode,
+					      unsigned int num_irqs)
 {
 	struct irq_sim_devres *dr;
-	int rv;
 
-	dr = devres_alloc(devm_irq_sim_release, sizeof(*dr), GFP_KERNEL);
+	dr = devres_alloc(devm_irq_domain_release_sim,
+			  sizeof(*dr), GFP_KERNEL);
 	if (!dr)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	rv = irq_sim_init(sim, num_irqs);
-	if (rv < 0) {
+	dr->domain = irq_domain_create_sim(fwnode, num_irqs);
+	if (IS_ERR(dr->domain)) {
 		devres_free(dr);
-		return rv;
+		return dr->domain;
 	}
 
-	dr->sim = sim;
 	devres_add(dev, dr);
-
-	return rv;
+	return dr->domain;
 }
-EXPORT_SYMBOL_GPL(devm_irq_sim_init);
-
-/**
- * irq_sim_fire - Enqueue an interrupt.
- *
- * @sim:        The interrupt simulator object.
- * @offset:     Offset of the simulated interrupt which should be fired.
- */
-void irq_sim_fire(struct irq_sim *sim, unsigned int offset)
-{
-	if (sim->irqs[offset].enabled) {
-		set_bit(offset, sim->work_ctx.pending);
-		irq_work_queue(&sim->work_ctx.work);
-	}
-}
-EXPORT_SYMBOL_GPL(irq_sim_fire);
-
-/**
- * irq_sim_irqnum - Get the allocated number of a dummy interrupt.
- *
- * @sim:        The interrupt simulator object.
- * @offset:     Offset of the simulated interrupt for which to retrieve
- *              the number.
- */
-int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset)
-{
-	return sim->irqs[offset].irqnum;
-}
-EXPORT_SYMBOL_GPL(irq_sim_irqnum);
+EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 9be995f..1a77236 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -638,9 +638,15 @@
 int generic_handle_irq(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
+	struct irq_data *data;
 
 	if (!desc)
 		return -EINVAL;
+
+	data = irq_desc_get_irq_data(desc);
+	if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
+		return -EPERM;
+
 	generic_handle_irq_desc(desc);
 	return 0;
 }
@@ -750,7 +756,7 @@
 EXPORT_SYMBOL_GPL(irq_free_descs);
 
 /**
- * irq_alloc_descs - allocate and initialize a range of irq descriptors
+ * __irq_alloc_descs - allocate and initialize a range of irq descriptors
  * @irq:	Allocate for specific irq number if irq >= 0
  * @from:	Start the search from this irq number
  * @cnt:	Number of consecutive irqs to allocate.
@@ -891,6 +897,7 @@
 }
 
 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
+	__releases(&desc->lock)
 {
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 	if (bus)
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 5e03cbe..c6b419d 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -46,11 +46,11 @@
 EXPORT_SYMBOL_GPL(irqchip_fwnode_ops);
 
 /**
- * irq_domain_alloc_fwnode - Allocate a fwnode_handle suitable for
+ * __irq_domain_alloc_fwnode - Allocate a fwnode_handle suitable for
  *                           identifying an irq domain
  * @type:	Type of irqchip_fwnode. See linux/irqdomain.h
- * @name:	Optional user provided domain name
  * @id:		Optional user provided id if name != NULL
+ * @name:	Optional user provided domain name
  * @pa:		Optional user-provided physical address
  *
  * Allocate a struct irqchip_fwid, and return a poiner to the embedded
@@ -132,18 +132,17 @@
 				    const struct irq_domain_ops *ops,
 				    void *host_data)
 {
-	struct device_node *of_node = to_of_node(fwnode);
 	struct irqchip_fwid *fwid;
 	struct irq_domain *domain;
 
 	static atomic_t unknown_domains;
 
 	domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
-			      GFP_KERNEL, of_node_to_nid(of_node));
+			      GFP_KERNEL, of_node_to_nid(to_of_node(fwnode)));
 	if (!domain)
 		return NULL;
 
-	if (fwnode && is_fwnode_irqchip(fwnode)) {
+	if (is_fwnode_irqchip(fwnode)) {
 		fwid = container_of(fwnode, struct irqchip_fwid, fwnode);
 
 		switch (fwid->type) {
@@ -162,30 +161,16 @@
 			domain->name = fwid->name;
 			break;
 		}
-#ifdef CONFIG_ACPI
-	} else if (is_acpi_device_node(fwnode)) {
-		struct acpi_buffer buf = {
-			.length = ACPI_ALLOCATE_BUFFER,
-		};
-		acpi_handle handle;
-
-		handle = acpi_device_handle(to_acpi_device_node(fwnode));
-		if (acpi_get_name(handle, ACPI_FULL_PATHNAME, &buf) == AE_OK) {
-			domain->name = buf.pointer;
-			domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
-		}
-
-		domain->fwnode = fwnode;
-#endif
-	} else if (of_node) {
+	} else if (is_of_node(fwnode) || is_acpi_device_node(fwnode) ||
+		   is_software_node(fwnode)) {
 		char *name;
 
 		/*
-		 * DT paths contain '/', which debugfs is legitimately
+		 * fwnode paths contain '/', which debugfs is legitimately
 		 * unhappy about. Replace them with ':', which does
 		 * the trick and is not as offensive as '\'...
 		 */
-		name = kasprintf(GFP_KERNEL, "%pOF", of_node);
+		name = kasprintf(GFP_KERNEL, "%pfw", fwnode);
 		if (!name) {
 			kfree(domain);
 			return NULL;
@@ -210,7 +195,7 @@
 		domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
 	}
 
-	of_node_get(of_node);
+	fwnode_handle_get(fwnode);
 
 	/* Fill structure */
 	INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
@@ -259,7 +244,7 @@
 
 	pr_debug("Removed domain %s\n", domain->name);
 
-	of_node_put(irq_domain_get_of_node(domain));
+	fwnode_handle_put(domain->fwnode);
 	if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
 		kfree(domain->name);
 	kfree(domain);
@@ -296,6 +281,7 @@
 
 	mutex_unlock(&irq_domain_mutex);
 }
+EXPORT_SYMBOL_GPL(irq_domain_update_bus_token);
 
 /**
  * irq_domain_add_simple() - Register an irq_domain and optionally map a range of irqs
@@ -990,6 +976,23 @@
 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
 
 /**
+ * irq_domain_translate_onecell() - Generic translate for direct one cell
+ * bindings
+ */
+int irq_domain_translate_onecell(struct irq_domain *d,
+				 struct irq_fwspec *fwspec,
+				 unsigned long *out_hwirq,
+				 unsigned int *out_type)
+{
+	if (WARN_ON(fwspec->param_count < 1))
+		return -EINVAL;
+	*out_hwirq = fwspec->param[0];
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_translate_onecell);
+
+/**
  * irq_domain_translate_twocell() - Generic translate for direct two cell
  * bindings
  *
@@ -1033,6 +1036,18 @@
 	return virq;
 }
 
+/**
+ * irq_domain_reset_irq_data - Clear hwirq, chip and chip_data in @irq_data
+ * @irq_data:	The pointer to irq_data
+ */
+void irq_domain_reset_irq_data(struct irq_data *irq_data)
+{
+	irq_data->hwirq = 0;
+	irq_data->chip = &no_irq_chip;
+	irq_data->chip_data = NULL;
+}
+EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);
+
 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
 /**
  * irq_domain_create_hierarchy - Add a irqdomain into the hierarchy
@@ -1124,6 +1139,17 @@
 	return irq_data;
 }
 
+static void __irq_domain_free_hierarchy(struct irq_data *irq_data)
+{
+	struct irq_data *tmp;
+
+	while (irq_data) {
+		tmp = irq_data;
+		irq_data = irq_data->parent_data;
+		kfree(tmp);
+	}
+}
+
 static void irq_domain_free_irq_data(unsigned int virq, unsigned int nr_irqs)
 {
 	struct irq_data *irq_data, *tmp;
@@ -1135,12 +1161,83 @@
 		irq_data->parent_data = NULL;
 		irq_data->domain = NULL;
 
-		while (tmp) {
-			irq_data = tmp;
-			tmp = tmp->parent_data;
-			kfree(irq_data);
+		__irq_domain_free_hierarchy(tmp);
+	}
+}
+
+/**
+ * irq_domain_disconnect_hierarchy - Mark the first unused level of a hierarchy
+ * @domain:	IRQ domain from which the hierarchy is to be disconnected
+ * @virq:	IRQ number where the hierarchy is to be trimmed
+ *
+ * Marks the @virq level belonging to @domain as disconnected.
+ * Returns -EINVAL if @virq doesn't have a valid irq_data pointing
+ * to @domain.
+ *
+ * Its only use is to be able to trim levels of hierarchy that do not
+ * have any real meaning for this interrupt, and that the driver marks
+ * as such from its .alloc() callback.
+ */
+int irq_domain_disconnect_hierarchy(struct irq_domain *domain,
+				    unsigned int virq)
+{
+	struct irq_data *irqd;
+
+	irqd = irq_domain_get_irq_data(domain, virq);
+	if (!irqd)
+		return -EINVAL;
+
+	irqd->chip = ERR_PTR(-ENOTCONN);
+	return 0;
+}
+
+static int irq_domain_trim_hierarchy(unsigned int virq)
+{
+	struct irq_data *tail, *irqd, *irq_data;
+
+	irq_data = irq_get_irq_data(virq);
+	tail = NULL;
+
+	/* The first entry must have a valid irqchip */
+	if (!irq_data->chip || IS_ERR(irq_data->chip))
+		return -EINVAL;
+
+	/*
+	 * Validate that the irq_data chain is sane in the presence of
+	 * a hierarchy trimming marker.
+	 */
+	for (irqd = irq_data->parent_data; irqd; irq_data = irqd, irqd = irqd->parent_data) {
+		/* Can't have a valid irqchip after a trim marker */
+		if (irqd->chip && tail)
+			return -EINVAL;
+
+		/* Can't have an empty irqchip before a trim marker */
+		if (!irqd->chip && !tail)
+			return -EINVAL;
+
+		if (IS_ERR(irqd->chip)) {
+			/* Only -ENOTCONN is a valid trim marker */
+			if (PTR_ERR(irqd->chip) != -ENOTCONN)
+				return -EINVAL;
+
+			tail = irq_data;
 		}
 	}
+
+	/* No trim marker, nothing to do */
+	if (!tail)
+		return 0;
+
+	pr_info("IRQ%d: trimming hierarchy from %s\n",
+		virq, tail->parent_data->domain->name);
+
+	/* Sever the inner part of the hierarchy...  */
+	irqd = tail;
+	tail = tail->parent_data;
+	irqd->parent_data = NULL;
+	__irq_domain_free_hierarchy(tail);
+
+	return 0;
 }
 
 static int irq_domain_alloc_irq_data(struct irq_domain *domain,
@@ -1234,18 +1331,6 @@
 EXPORT_SYMBOL(irq_domain_set_info);
 
 /**
- * irq_domain_reset_irq_data - Clear hwirq, chip and chip_data in @irq_data
- * @irq_data:	The pointer to irq_data
- */
-void irq_domain_reset_irq_data(struct irq_data *irq_data)
-{
-	irq_data->hwirq = 0;
-	irq_data->chip = &no_irq_chip;
-	irq_data->chip_data = NULL;
-}
-EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);
-
-/**
  * irq_domain_free_irqs_common - Clear irq_data and free the parent
  * @domain:	Interrupt domain to match
  * @virq:	IRQ number to start with
@@ -1369,6 +1454,15 @@
 		mutex_unlock(&irq_domain_mutex);
 		goto out_free_irq_data;
 	}
+
+	for (i = 0; i < nr_irqs; i++) {
+		ret = irq_domain_trim_hierarchy(virq + i);
+		if (ret) {
+			mutex_unlock(&irq_domain_mutex);
+			goto out_free_irq_data;
+		}
+	}
+	
 	for (i = 0; i < nr_irqs; i++)
 		irq_domain_insert_irq(virq + i);
 	mutex_unlock(&irq_domain_mutex);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 918fe05..79dc02b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -18,6 +18,7 @@
 #include <linux/sched.h>
 #include <linux/sched/rt.h>
 #include <linux/sched/task.h>
+#include <linux/sched/isolation.h>
 #include <uapi/linux/sched/types.h>
 #include <linux/task_work.h>
 
@@ -227,12 +228,50 @@
 	if (!chip || !chip->irq_set_affinity)
 		return -EINVAL;
 
-	ret = chip->irq_set_affinity(data, mask, force);
+	/*
+	 * If this is a managed interrupt and housekeeping is enabled on
+	 * it check whether the requested affinity mask intersects with
+	 * a housekeeping CPU. If so, then remove the isolated CPUs from
+	 * the mask and just keep the housekeeping CPU(s). This prevents
+	 * the affinity setter from routing the interrupt to an isolated
+	 * CPU to avoid that I/O submitted from a housekeeping CPU causes
+	 * interrupts on an isolated one.
+	 *
+	 * If the masks do not intersect or include online CPU(s) then
+	 * keep the requested mask. The isolated target CPUs are only
+	 * receiving interrupts when the I/O operation was submitted
+	 * directly from them.
+	 *
+	 * If all housekeeping CPUs in the affinity mask are offline, the
+	 * interrupt will be migrated by the CPU hotplug code once a
+	 * housekeeping CPU which belongs to the affinity mask comes
+	 * online.
+	 */
+	if (irqd_affinity_is_managed(data) &&
+	    housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
+		const struct cpumask *hk_mask, *prog_mask;
+
+		static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
+		static struct cpumask tmp_mask;
+
+		hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
+
+		raw_spin_lock(&tmp_mask_lock);
+		cpumask_and(&tmp_mask, mask, hk_mask);
+		if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
+			prog_mask = mask;
+		else
+			prog_mask = &tmp_mask;
+		ret = chip->irq_set_affinity(data, prog_mask, force);
+		raw_spin_unlock(&tmp_mask_lock);
+	} else {
+		ret = chip->irq_set_affinity(data, mask, force);
+	}
 	switch (ret) {
 	case IRQ_SET_MASK_OK:
 	case IRQ_SET_MASK_OK_DONE:
 		cpumask_copy(desc->irq_common_data.affinity, mask);
-		/* fall through */
+		fallthrough;
 	case IRQ_SET_MASK_OK_NOCOPY:
 		irq_validate_effective_affinity(data);
 		irq_set_thread_affinity(desc);
@@ -722,6 +761,13 @@
  *
  *	Wakeup mode lets this IRQ wake the system from sleep
  *	states like "suspend to RAM".
+ *
+ *	Note: irq enable/disable state is completely orthogonal
+ *	to the enable/disable state of irq wake. An irq can be
+ *	disabled with disable_irq() and still wake the system as
+ *	long as the irq has wake enabled. If this does not hold,
+ *	then the underlying irq chip and the related driver need
+ *	to be investigated.
  */
 int irq_set_irq_wake(unsigned int irq, unsigned int on)
 {
@@ -822,7 +868,7 @@
 	case IRQ_SET_MASK_OK_DONE:
 		irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
 		irqd_set(&desc->irq_data, flags);
-		/* fall through */
+		fallthrough;
 
 	case IRQ_SET_MASK_OK_NOCOPY:
 		flags = irqd_get_trigger_type(&desc->irq_data);
@@ -1120,7 +1166,7 @@
 		handler_fn = irq_thread_fn;
 
 	init_task_work(&on_exit_work, irq_thread_dtor);
-	task_work_add(current, &on_exit_work, false);
+	task_work_add(current, &on_exit_work, TWA_NONE);
 
 	irq_thread_check_affinity(desc, action);
 
@@ -1266,9 +1312,6 @@
 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
 {
 	struct task_struct *t;
-	struct sched_param param = {
-		.sched_priority = MAX_USER_RT_PRIO/2,
-	};
 
 	if (!secondary) {
 		t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
@@ -1276,13 +1319,12 @@
 	} else {
 		t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
 				   new->name);
-		param.sched_priority -= 1;
 	}
 
 	if (IS_ERR(t))
 		return PTR_ERR(t);
 
-	sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
+	sched_set_fifo(t);
 
 	/*
 	 * We keep the reference to the task struct even if
@@ -1534,8 +1576,8 @@
 		 * has. The type flags are unreliable as the
 		 * underlying chip implementation can override them.
 		 */
-		pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
-		       irq);
+		pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
+		       new->name, irq);
 		ret = -EINVAL;
 		goto out_unlock;
 	}
@@ -1685,34 +1727,6 @@
 	return ret;
 }
 
-/**
- *	setup_irq - setup an interrupt
- *	@irq: Interrupt line to setup
- *	@act: irqaction for the interrupt
- *
- * Used to statically setup interrupts in the early boot process.
- */
-int setup_irq(unsigned int irq, struct irqaction *act)
-{
-	int retval;
-	struct irq_desc *desc = irq_to_desc(irq);
-
-	if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
-		return -EINVAL;
-
-	retval = irq_chip_pm_get(&desc->irq_data);
-	if (retval < 0)
-		return retval;
-
-	retval = __setup_irq(irq, desc, act);
-
-	if (retval)
-		irq_chip_pm_put(&desc->irq_data);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(setup_irq);
-
 /*
  * Internal function to unregister an irqaction - used to free
  * regular and special interrupts that are part of the architecture.
@@ -1854,22 +1868,6 @@
 }
 
 /**
- *	remove_irq - free an interrupt
- *	@irq: Interrupt line to free
- *	@act: irqaction for the interrupt
- *
- * Used to remove interrupts statically setup by the early boot process.
- */
-void remove_irq(unsigned int irq, struct irqaction *act)
-{
-	struct irq_desc *desc = irq_to_desc(irq);
-
-	if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
-		__free_irq(desc, act->dev_id);
-}
-EXPORT_SYMBOL_GPL(remove_irq);
-
-/**
  *	free_irq - free an interrupt allocated with request_irq
  *	@irq: Interrupt line to free
  *	@dev_id: Device identity to free
@@ -2658,6 +2656,8 @@
 
 	do {
 		chip = irq_data_get_irq_chip(data);
+		if (WARN_ON_ONCE(!chip))
+			return -ENODEV;
 		if (chip->irq_get_irqchip_state)
 			break;
 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
@@ -2735,6 +2735,10 @@
 
 	do {
 		chip = irq_data_get_irq_chip(data);
+		if (WARN_ON_ONCE(!chip)) {
+			err = -ENODEV;
+			goto out_unlock;
+		}
 		if (chip->irq_set_irqchip_state)
 			break;
 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
@@ -2747,6 +2751,7 @@
 	if (data)
 		err = chip->irq_set_irqchip_state(data, which, val);
 
+out_unlock:
 	irq_put_desc_busunlock(desc, flags);
 	return err;
 }
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index b7e4c59..d217acc 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -187,7 +187,6 @@
 	.deactivate	= msi_domain_deactivate,
 };
 
-#ifdef GENERIC_MSI_DOMAIN_OPS
 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
 						msi_alloc_info_t *arg)
 {
@@ -206,11 +205,6 @@
 {
 	arg->desc = desc;
 }
-#else
-#define msi_domain_ops_get_hwirq	NULL
-#define msi_domain_ops_prepare		NULL
-#define msi_domain_ops_set_desc		NULL
-#endif /* !GENERIC_MSI_DOMAIN_OPS */
 
 static int msi_domain_ops_init(struct irq_domain *domain,
 			       struct msi_domain_info *info,
@@ -235,11 +229,13 @@
 }
 
 static struct msi_domain_ops msi_domain_ops_default = {
-	.get_hwirq	= msi_domain_ops_get_hwirq,
-	.msi_init	= msi_domain_ops_init,
-	.msi_check	= msi_domain_ops_check,
-	.msi_prepare	= msi_domain_ops_prepare,
-	.set_desc	= msi_domain_ops_set_desc,
+	.get_hwirq		= msi_domain_ops_get_hwirq,
+	.msi_init		= msi_domain_ops_init,
+	.msi_check		= msi_domain_ops_check,
+	.msi_prepare		= msi_domain_ops_prepare,
+	.set_desc		= msi_domain_ops_set_desc,
+	.domain_alloc_irqs	= __msi_domain_alloc_irqs,
+	.domain_free_irqs	= __msi_domain_free_irqs,
 };
 
 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
@@ -251,6 +247,14 @@
 		return;
 	}
 
+	if (ops->domain_alloc_irqs == NULL)
+		ops->domain_alloc_irqs = msi_domain_ops_default.domain_alloc_irqs;
+	if (ops->domain_free_irqs == NULL)
+		ops->domain_free_irqs = msi_domain_ops_default.domain_free_irqs;
+
+	if (!(info->flags & MSI_FLAG_USE_DEF_DOM_OPS))
+		return;
+
 	if (ops->get_hwirq == NULL)
 		ops->get_hwirq = msi_domain_ops_default.get_hwirq;
 	if (ops->msi_init == NULL)
@@ -284,8 +288,7 @@
 {
 	struct irq_domain *domain;
 
-	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
-		msi_domain_update_dom_ops(info);
+	msi_domain_update_dom_ops(info);
 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 		msi_domain_update_chip_ops(info);
 
@@ -370,8 +373,13 @@
 {
 	struct msi_desc *desc;
 
-	if (domain->bus_token != DOMAIN_BUS_PCI_MSI)
+	switch(domain->bus_token) {
+	case DOMAIN_BUS_PCI_MSI:
+	case DOMAIN_BUS_VMD_MSI:
+		break;
+	default:
 		return false;
+	}
 
 	if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
 		return false;
@@ -387,17 +395,8 @@
 	return desc->msi_attrib.is_msix || desc->msi_attrib.maskbit;
 }
 
-/**
- * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
- * @domain:	The domain to allocate from
- * @dev:	Pointer to device struct of the device for which the interrupts
- *		are allocated
- * @nvec:	The number of interrupts to allocate
- *
- * Returns 0 on success or an error code.
- */
-int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
-			  int nvec)
+int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+			    int nvec)
 {
 	struct msi_domain_info *info = domain->host_data;
 	struct msi_domain_ops *ops = info->ops;
@@ -482,12 +481,24 @@
 }
 
 /**
- * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
- * @domain:	The domain to managing the interrupts
+ * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
+ * @domain:	The domain to allocate from
  * @dev:	Pointer to device struct of the device for which the interrupts
- *		are free
+ *		are allocated
+ * @nvec:	The number of interrupts to allocate
+ *
+ * Returns 0 on success or an error code.
  */
-void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+			  int nvec)
+{
+	struct msi_domain_info *info = domain->host_data;
+	struct msi_domain_ops *ops = info->ops;
+
+	return ops->domain_alloc_irqs(domain, dev, nvec);
+}
+
+void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
 {
 	struct irq_data *irq_data;
 	struct msi_desc *desc;
@@ -513,6 +524,20 @@
 }
 
 /**
+ * __msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
+ * @domain:	The domain to managing the interrupts
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are free
+ */
+void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+{
+	struct msi_domain_info *info = domain->host_data;
+	struct msi_domain_ops *ops = info->ops;
+
+	return ops->domain_free_irqs(domain, dev);
+}
+
+/**
  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
  * @domain:	The interrupt domain to retrieve data from
  *
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index c6c7e18..ce0adb2 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -69,12 +69,26 @@
 
 static bool suspend_device_irq(struct irq_desc *desc)
 {
+	unsigned long chipflags = irq_desc_get_chip(desc)->flags;
+	struct irq_data *irqd = &desc->irq_data;
+
 	if (!desc->action || irq_desc_is_chained(desc) ||
 	    desc->no_suspend_depth)
 		return false;
 
-	if (irqd_is_wakeup_set(&desc->irq_data)) {
-		irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
+	if (irqd_is_wakeup_set(irqd)) {
+		irqd_set(irqd, IRQD_WAKEUP_ARMED);
+
+		if ((chipflags & IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND) &&
+		     irqd_irq_disabled(irqd)) {
+			/*
+			 * Interrupt marked for wakeup is in disabled state.
+			 * Enable interrupt here to unmask/enable in irqchip
+			 * to be able to resume with such interrupts.
+			 */
+			__enable_irq(desc);
+			irqd_set(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND);
+		}
 		/*
 		 * We return true here to force the caller to issue
 		 * synchronize_irq(). We need to make sure that the
@@ -93,7 +107,7 @@
 	 * chip level. The chip implementation indicates that with
 	 * IRQCHIP_MASK_ON_SUSPEND.
 	 */
-	if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
+	if (chipflags & IRQCHIP_MASK_ON_SUSPEND)
 		mask_irq(desc);
 	return true;
 }
@@ -137,7 +151,19 @@
 
 static void resume_irq(struct irq_desc *desc)
 {
-	irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
+	struct irq_data *irqd = &desc->irq_data;
+
+	irqd_clear(irqd, IRQD_WAKEUP_ARMED);
+
+	if (irqd_is_enabled_on_suspend(irqd)) {
+		/*
+		 * Interrupt marked for wakeup was enabled during suspend
+		 * entry. Disable such interrupts to restore them back to
+		 * original state.
+		 */
+		__disable_irq(desc);
+		irqd_clear(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND);
+	}
 
 	if (desc->istate & IRQS_SUSPENDED)
 		goto resume;
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index f5958c5..72513ed 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -198,20 +198,20 @@
 	return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
 }
 
-static const struct file_operations irq_affinity_proc_fops = {
-	.open		= irq_affinity_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-	.write		= irq_affinity_proc_write,
+static const struct proc_ops irq_affinity_proc_ops = {
+	.proc_open	= irq_affinity_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
+	.proc_write	= irq_affinity_proc_write,
 };
 
-static const struct file_operations irq_affinity_list_proc_fops = {
-	.open		= irq_affinity_list_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-	.write		= irq_affinity_list_proc_write,
+static const struct proc_ops irq_affinity_list_proc_ops = {
+	.proc_open	= irq_affinity_list_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
+	.proc_write	= irq_affinity_list_proc_write,
 };
 
 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
@@ -268,12 +268,12 @@
 	return single_open(file, default_affinity_show, PDE_DATA(inode));
 }
 
-static const struct file_operations default_affinity_proc_fops = {
-	.open		= default_affinity_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-	.write		= default_affinity_write,
+static const struct proc_ops default_affinity_proc_ops = {
+	.proc_open	= default_affinity_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
+	.proc_write	= default_affinity_write,
 };
 
 static int irq_node_proc_show(struct seq_file *m, void *v)
@@ -364,7 +364,7 @@
 #ifdef CONFIG_SMP
 	/* create /proc/irq/<irq>/smp_affinity */
 	proc_create_data("smp_affinity", 0644, desc->dir,
-			 &irq_affinity_proc_fops, irqp);
+			 &irq_affinity_proc_ops, irqp);
 
 	/* create /proc/irq/<irq>/affinity_hint */
 	proc_create_single_data("affinity_hint", 0444, desc->dir,
@@ -372,7 +372,7 @@
 
 	/* create /proc/irq/<irq>/smp_affinity_list */
 	proc_create_data("smp_affinity_list", 0644, desc->dir,
-			 &irq_affinity_list_proc_fops, irqp);
+			 &irq_affinity_list_proc_ops, irqp);
 
 	proc_create_single_data("node", 0444, desc->dir, irq_node_proc_show,
 			irqp);
@@ -423,7 +423,7 @@
 {
 #ifdef CONFIG_SMP
 	proc_create("irq/default_smp_affinity", 0644, NULL,
-		    &default_affinity_proc_fops);
+		    &default_affinity_proc_ops);
 #endif
 }
 
@@ -485,7 +485,7 @@
 
 	rcu_read_lock();
 	desc = irq_to_desc(i);
-	if (!desc)
+	if (!desc || irq_settings_is_hidden(desc))
 		goto outsparse;
 
 	if (desc->kstat_irqs)
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index 98c04ca..8ccd32a 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -45,58 +45,140 @@
 }
 
 /* Tasklet to handle resend: */
-static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
+static DECLARE_TASKLET_OLD(resend_tasklet, resend_irqs);
 
+static int irq_sw_resend(struct irq_desc *desc)
+{
+	unsigned int irq = irq_desc_get_irq(desc);
+
+	/*
+	 * Validate whether this interrupt can be safely injected from
+	 * non interrupt context
+	 */
+	if (handle_enforce_irqctx(&desc->irq_data))
+		return -EINVAL;
+
+	/*
+	 * If the interrupt is running in the thread context of the parent
+	 * irq we need to be careful, because we cannot trigger it
+	 * directly.
+	 */
+	if (irq_settings_is_nested_thread(desc)) {
+		/*
+		 * If the parent_irq is valid, we retrigger the parent,
+		 * otherwise we do nothing.
+		 */
+		if (!desc->parent_irq)
+			return -EINVAL;
+		irq = desc->parent_irq;
+	}
+
+	/* Set it pending and activate the softirq: */
+	set_bit(irq, irqs_resend);
+	tasklet_schedule(&resend_tasklet);
+	return 0;
+}
+
+#else
+static int irq_sw_resend(struct irq_desc *desc)
+{
+	return -EINVAL;
+}
 #endif
 
+static int try_retrigger(struct irq_desc *desc)
+{
+	if (desc->irq_data.chip->irq_retrigger)
+		return desc->irq_data.chip->irq_retrigger(&desc->irq_data);
+
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+	return irq_chip_retrigger_hierarchy(&desc->irq_data);
+#else
+	return 0;
+#endif
+}
+
 /*
  * IRQ resend
  *
  * Is called with interrupts disabled and desc->lock held.
  */
-void check_irq_resend(struct irq_desc *desc)
+int check_irq_resend(struct irq_desc *desc, bool inject)
 {
+	int err = 0;
+
 	/*
-	 * We do not resend level type interrupts. Level type
-	 * interrupts are resent by hardware when they are still
-	 * active. Clear the pending bit so suspend/resume does not
-	 * get confused.
+	 * We do not resend level type interrupts. Level type interrupts
+	 * are resent by hardware when they are still active. Clear the
+	 * pending bit so suspend/resume does not get confused.
 	 */
 	if (irq_settings_is_level(desc)) {
 		desc->istate &= ~IRQS_PENDING;
-		return;
+		return -EINVAL;
 	}
+
 	if (desc->istate & IRQS_REPLAY)
-		return;
-	if (desc->istate & IRQS_PENDING) {
-		desc->istate &= ~IRQS_PENDING;
+		return -EBUSY;
+
+	if (!(desc->istate & IRQS_PENDING) && !inject)
+		return 0;
+
+	desc->istate &= ~IRQS_PENDING;
+
+	if (!try_retrigger(desc))
+		err = irq_sw_resend(desc);
+
+	/* If the retrigger was successfull, mark it with the REPLAY bit */
+	if (!err)
 		desc->istate |= IRQS_REPLAY;
-
-		if (!desc->irq_data.chip->irq_retrigger ||
-		    !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
-#ifdef CONFIG_HARDIRQS_SW_RESEND
-			unsigned int irq = irq_desc_get_irq(desc);
-
-			/*
-			 * If the interrupt is running in the thread
-			 * context of the parent irq we need to be
-			 * careful, because we cannot trigger it
-			 * directly.
-			 */
-			if (irq_settings_is_nested_thread(desc)) {
-				/*
-				 * If the parent_irq is valid, we
-				 * retrigger the parent, otherwise we
-				 * do nothing.
-				 */
-				if (!desc->parent_irq)
-					return;
-				irq = desc->parent_irq;
-			}
-			/* Set it pending and activate the softirq: */
-			set_bit(irq, irqs_resend);
-			tasklet_schedule(&resend_tasklet);
-#endif
-		}
-	}
+	return err;
 }
+
+#ifdef CONFIG_GENERIC_IRQ_INJECTION
+/**
+ * irq_inject_interrupt - Inject an interrupt for testing/error injection
+ * @irq:	The interrupt number
+ *
+ * This function must only be used for debug and testing purposes!
+ *
+ * Especially on x86 this can cause a premature completion of an interrupt
+ * affinity change causing the interrupt line to become stale. Very
+ * unlikely, but possible.
+ *
+ * The injection can fail for various reasons:
+ * - Interrupt is not activated
+ * - Interrupt is NMI type or currently replaying
+ * - Interrupt is level type
+ * - Interrupt does not support hardware retrigger and software resend is
+ *   either not enabled or not possible for the interrupt.
+ */
+int irq_inject_interrupt(unsigned int irq)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+	int err;
+
+	/* Try the state injection hardware interface first */
+	if (!irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, true))
+		return 0;
+
+	/* That failed, try via the resend mechanism */
+	desc = irq_get_desc_buslock(irq, &flags, 0);
+	if (!desc)
+		return -EINVAL;
+
+	/*
+	 * Only try to inject when the interrupt is:
+	 *  - not NMI type
+	 *  - activated
+	 */
+	if ((desc->istate & IRQS_NMI) || !irqd_is_activated(&desc->irq_data))
+		err = -EINVAL;
+	else
+		err = check_irq_resend(desc, true);
+
+	irq_put_desc_busunlock(desc, flags);
+	return err;
+}
+EXPORT_SYMBOL_GPL(irq_inject_interrupt);
+#endif
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index e43795c..403378b 100644
--- a/kernel/irq/settings.h
+++ b/kernel/irq/settings.h
@@ -17,6 +17,7 @@
 	_IRQ_PER_CPU_DEVID	= IRQ_PER_CPU_DEVID,
 	_IRQ_IS_POLLED		= IRQ_IS_POLLED,
 	_IRQ_DISABLE_UNLAZY	= IRQ_DISABLE_UNLAZY,
+	_IRQ_HIDDEN		= IRQ_HIDDEN,
 	_IRQF_MODIFY_MASK	= IRQF_MODIFY_MASK,
 };
 
@@ -31,6 +32,7 @@
 #define IRQ_PER_CPU_DEVID	GOT_YOU_MORON
 #define IRQ_IS_POLLED		GOT_YOU_MORON
 #define IRQ_DISABLE_UNLAZY	GOT_YOU_MORON
+#define IRQ_HIDDEN		GOT_YOU_MORON
 #undef IRQF_MODIFY_MASK
 #define IRQF_MODIFY_MASK	GOT_YOU_MORON
 
@@ -167,3 +169,8 @@
 {
 	desc->status_use_accessors &= ~_IRQ_DISABLE_UNLAZY;
 }
+
+static inline bool irq_settings_is_hidden(struct irq_desc *desc)
+{
+	return desc->status_use_accessors & _IRQ_HIDDEN;
+}
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 2ed97a7..f865e5f 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -34,6 +34,7 @@
  * true and let the handler run.
  */
 bool irq_wait_for_poll(struct irq_desc *desc)
+	__must_hold(&desc->lock)
 {
 	if (WARN_ONCE(irq_poll_cpu == smp_processor_id(),
 		      "irq poll in progress on cpu %d for irq %d\n",
diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c
index 7ccc8ed..1f98116 100644
--- a/kernel/irq/timings.c
+++ b/kernel/irq/timings.c
@@ -609,7 +609,7 @@
 
 	/*
 	 * Some platforms can have the same private interrupt per cpu,
-	 * so this function may be be called several times with the
+	 * so this function may be called several times with the
 	 * same interrupt number. Just bail out in case the per cpu
 	 * stat structure is already allocated.
 	 */
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index d42acaf..eca8396 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -29,24 +29,16 @@
  */
 static bool irq_work_claim(struct irq_work *work)
 {
-	unsigned long flags, oflags, nflags;
+	int oflags;
 
+	oflags = atomic_fetch_or(IRQ_WORK_CLAIMED | CSD_TYPE_IRQ_WORK, &work->flags);
 	/*
-	 * Start with our best wish as a premise but only trust any
-	 * flag value after cmpxchg() result.
+	 * If the work is already pending, no need to raise the IPI.
+	 * The pairing atomic_fetch_andnot() in irq_work_run() makes sure
+	 * everything we did before is visible.
 	 */
-	flags = work->flags & ~IRQ_WORK_PENDING;
-	for (;;) {
-		nflags = flags | IRQ_WORK_CLAIMED;
-		oflags = cmpxchg(&work->flags, flags, nflags);
-		if (oflags == flags)
-			break;
-		if (oflags & IRQ_WORK_PENDING)
-			return false;
-		flags = oflags;
-		cpu_relax();
-	}
-
+	if (oflags & IRQ_WORK_PENDING)
+		return false;
 	return true;
 }
 
@@ -61,7 +53,7 @@
 static void __irq_work_queue_local(struct irq_work *work)
 {
 	/* If the work is "lazy", handle it from next tick if any */
-	if (work->flags & IRQ_WORK_LAZY) {
+	if (atomic_read(&work->flags) & IRQ_WORK_LAZY) {
 		if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) &&
 		    tick_nohz_tick_stopped())
 			arch_irq_work_raise();
@@ -110,8 +102,7 @@
 	if (cpu != smp_processor_id()) {
 		/* Arch remote IPI send/receive backend aren't NMI safe */
 		WARN_ON_ONCE(in_nmi());
-		if (llist_add(&work->llnode, &per_cpu(raised_list, cpu)))
-			arch_send_call_function_single_ipi(cpu);
+		__smp_call_single_queue(cpu, &work->llnode);
 	} else {
 		__irq_work_queue_local(work);
 	}
@@ -139,11 +130,35 @@
 	return true;
 }
 
+void irq_work_single(void *arg)
+{
+	struct irq_work *work = arg;
+	int flags;
+
+	/*
+	 * Clear the PENDING bit, after this point the @work
+	 * can be re-used.
+	 * Make it immediately visible so that other CPUs trying
+	 * to claim that work don't rely on us to handle their data
+	 * while we are in the middle of the func.
+	 */
+	flags = atomic_fetch_andnot(IRQ_WORK_PENDING, &work->flags);
+
+	lockdep_irq_work_enter(work);
+	work->func(work);
+	lockdep_irq_work_exit(work);
+	/*
+	 * Clear the BUSY bit and return to the free state if
+	 * no-one else claimed it meanwhile.
+	 */
+	flags &= ~IRQ_WORK_PENDING;
+	(void)atomic_cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY);
+}
+
 static void irq_work_run_list(struct llist_head *list)
 {
 	struct irq_work *work, *tmp;
 	struct llist_node *llnode;
-	unsigned long flags;
 
 	BUG_ON(!irqs_disabled());
 
@@ -151,24 +166,8 @@
 		return;
 
 	llnode = llist_del_all(list);
-	llist_for_each_entry_safe(work, tmp, llnode, llnode) {
-		/*
-		 * Clear the PENDING bit, after this point the @work
-		 * can be re-used.
-		 * Make it immediately visible so that other CPUs trying
-		 * to claim that work don't rely on us to handle their data
-		 * while we are in the middle of the func.
-		 */
-		flags = work->flags & ~IRQ_WORK_PENDING;
-		xchg(&work->flags, flags);
-
-		work->func(work);
-		/*
-		 * Clear the BUSY bit and return to the free state if
-		 * no-one else claimed it meanwhile.
-		 */
-		(void)cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY);
-	}
+	llist_for_each_entry_safe(work, tmp, llnode, llnode)
+		irq_work_single(work);
 }
 
 /*
@@ -199,7 +198,7 @@
 {
 	lockdep_assert_irqs_enabled();
 
-	while (work->flags & IRQ_WORK_BUSY)
+	while (atomic_read(&work->flags) & IRQ_WORK_BUSY)
 		cpu_relax();
 }
 EXPORT_SYMBOL_GPL(irq_work_sync);
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index cdb3ffa..4ae693c 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -19,7 +19,7 @@
 #include <linux/cpu.h>
 #include <asm/sections.h>
 
-/* mutex to protect coming/going of the the jump_label table */
+/* mutex to protect coming/going of the jump_label table */
 static DEFINE_MUTEX(jump_label_mutex);
 
 void jump_label_lock(void)
@@ -316,14 +316,16 @@
 }
 
 static int __jump_label_text_reserved(struct jump_entry *iter_start,
-		struct jump_entry *iter_stop, void *start, void *end)
+		struct jump_entry *iter_stop, void *start, void *end, bool init)
 {
 	struct jump_entry *iter;
 
 	iter = iter_start;
 	while (iter < iter_stop) {
-		if (addr_conflict(iter, start, end))
-			return 1;
+		if (init || !jump_entry_is_init(iter)) {
+			if (addr_conflict(iter, start, end))
+				return 1;
+		}
 		iter++;
 	}
 
@@ -407,6 +409,14 @@
 		return false;
 
 	if (!kernel_text_address(jump_entry_code(entry))) {
+		/*
+		 * This skips patching built-in __exit, which
+		 * is part of init_section_contains() but is
+		 * not part of kernel_text_address().
+		 *
+		 * Skipping built-in __exit is fine since it
+		 * will never be executed.
+		 */
 		WARN_ONCE(!jump_entry_is_init(entry),
 			  "can't patch jump_label at %pS",
 			  (void *)jump_entry_code(entry));
@@ -539,19 +549,25 @@
 static int __jump_label_mod_text_reserved(void *start, void *end)
 {
 	struct module *mod;
+	int ret;
 
 	preempt_disable();
 	mod = __module_text_address((unsigned long)start);
 	WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
+	if (!try_module_get(mod))
+		mod = NULL;
 	preempt_enable();
 
 	if (!mod)
 		return 0;
 
-
-	return __jump_label_text_reserved(mod->jump_entries,
+	ret = __jump_label_text_reserved(mod->jump_entries,
 				mod->jump_entries + mod->num_jump_entries,
-				start, end);
+				start, end, mod->state == MODULE_STATE_COMING);
+
+	module_put(mod);
+
+	return ret;
 }
 
 static void __jump_label_mod_update(struct static_key *key)
@@ -772,8 +788,9 @@
  */
 int jump_label_text_reserved(void *start, void *end)
 {
+	bool init = system_state < SYSTEM_RUNNING;
 	int ret = __jump_label_text_reserved(__start___jump_table,
-			__stop___jump_table, start, end);
+			__stop___jump_table, start, end, init);
 
 	if (ret)
 		return ret;
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 61f9d78..fe9de06 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/filter.h>
 #include <linux/ftrace.h>
+#include <linux/kprobes.h>
 #include <linux/compiler.h>
 
 /*
@@ -39,12 +40,12 @@
  * has one (eg: FRV).
  */
 extern const unsigned int kallsyms_num_syms
-__attribute__((weak, section(".rodata")));
+__section(".rodata") __attribute__((weak));
 
 extern const unsigned long kallsyms_relative_base
-__attribute__((weak, section(".rodata")));
+__section(".rodata") __attribute__((weak));
 
-extern const u8 kallsyms_token_table[] __weak;
+extern const char kallsyms_token_table[] __weak;
 extern const u16 kallsyms_token_index[] __weak;
 
 extern const unsigned int kallsyms_markers[] __weak;
@@ -58,7 +59,8 @@
 					   char *result, size_t maxlen)
 {
 	int len, skipped_first = 0;
-	const u8 *tptr, *data;
+	const char *tptr;
+	const u8 *data;
 
 	/* Get the compressed symbol length from the first symbol byte. */
 	data = &kallsyms_names[off];
@@ -174,7 +176,6 @@
 	}
 	return module_kallsyms_lookup_name(name);
 }
-EXPORT_SYMBOL_GPL(kallsyms_lookup_name);
 
 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
 				      unsigned long),
@@ -193,7 +194,6 @@
 	}
 	return module_kallsyms_on_each_symbol(fn, data);
 }
-EXPORT_SYMBOL_GPL(kallsyms_on_each_symbol);
 
 static unsigned long get_symbol_pos(unsigned long addr,
 				    unsigned long *symbolsize,
@@ -438,6 +438,7 @@
 	loff_t pos_arch_end;
 	loff_t pos_mod_end;
 	loff_t pos_ftrace_mod_end;
+	loff_t pos_bpf_end;
 	unsigned long value;
 	unsigned int nameoff; /* If iterating in core kernel symbols. */
 	char type;
@@ -481,6 +482,11 @@
 	return 1;
 }
 
+/*
+ * ftrace_mod_get_kallsym() may also get symbols for pages allocated for ftrace
+ * purposes. In that case "__builtin__ftrace" is used as a module name, even
+ * though "__builtin__ftrace" is not a module.
+ */
 static int get_ksymbol_ftrace_mod(struct kallsym_iter *iter)
 {
 	int ret = ftrace_mod_get_kallsym(iter->pos - iter->pos_mod_end,
@@ -497,11 +503,33 @@
 
 static int get_ksymbol_bpf(struct kallsym_iter *iter)
 {
+	int ret;
+
 	strlcpy(iter->module_name, "bpf", MODULE_NAME_LEN);
 	iter->exported = 0;
-	return bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end,
-			       &iter->value, &iter->type,
-			       iter->name) < 0 ? 0 : 1;
+	ret = bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end,
+			      &iter->value, &iter->type,
+			      iter->name);
+	if (ret < 0) {
+		iter->pos_bpf_end = iter->pos;
+		return 0;
+	}
+
+	return 1;
+}
+
+/*
+ * This uses "__builtin__kprobes" as a module name for symbols for pages
+ * allocated for kprobes' purposes, even though "__builtin__kprobes" is not a
+ * module.
+ */
+static int get_ksymbol_kprobe(struct kallsym_iter *iter)
+{
+	strlcpy(iter->module_name, "__builtin__kprobes", MODULE_NAME_LEN);
+	iter->exported = 0;
+	return kprobe_get_kallsym(iter->pos - iter->pos_bpf_end,
+				  &iter->value, &iter->type,
+				  iter->name) < 0 ? 0 : 1;
 }
 
 /* Returns space to next name. */
@@ -528,6 +556,7 @@
 		iter->pos_arch_end = 0;
 		iter->pos_mod_end = 0;
 		iter->pos_ftrace_mod_end = 0;
+		iter->pos_bpf_end = 0;
 	}
 }
 
@@ -552,7 +581,11 @@
 	    get_ksymbol_ftrace_mod(iter))
 		return 1;
 
-	return get_ksymbol_bpf(iter);
+	if ((!iter->pos_bpf_end || iter->pos_bpf_end > pos) &&
+	    get_ksymbol_bpf(iter))
+		return 1;
+
+	return get_ksymbol_kprobe(iter);
 }
 
 /* Returns false if pos at or past end of file. */
@@ -651,12 +684,12 @@
 	case 0:
 		if (kallsyms_for_perf())
 			return true;
-	/* fallthrough */
+		fallthrough;
 	case 1:
 		if (security_capable(cred, &init_user_ns, CAP_SYSLOG,
 				     CAP_OPT_NOAUDIT) == 0)
 			return true;
-	/* fallthrough */
+		fallthrough;
 	default:
 		return false;
 	}
@@ -703,16 +736,16 @@
 }
 #endif	/* CONFIG_KGDB_KDB */
 
-static const struct file_operations kallsyms_operations = {
-	.open = kallsyms_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = seq_release_private,
+static const struct proc_ops kallsyms_proc_ops = {
+	.proc_open	= kallsyms_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release_private,
 };
 
 static int __init kallsyms_init(void)
 {
-	proc_create("kallsyms", 0444, NULL, &kallsyms_operations);
+	proc_create("kallsyms", 0444, NULL, &kallsyms_proc_ops);
 	return 0;
 }
 device_initcall(kallsyms_init);
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 2ee3872..6b8368b 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -9,6 +9,7 @@
 #include <linux/types.h>
 #include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/hashtable.h>
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/preempt.h>
@@ -21,8 +22,11 @@
 #include <linux/uaccess.h>
 #include <linux/kcov.h>
 #include <linux/refcount.h>
+#include <linux/log2.h>
 #include <asm/setup.h>
 
+#define kcov_debug(fmt, ...) pr_debug("%s: " fmt, __func__, ##__VA_ARGS__)
+
 /* Number of 64-bit words written per one comparison: */
 #define KCOV_WORDS_PER_CMP 4
 
@@ -44,28 +48,119 @@
 	 * Reference counter. We keep one for:
 	 *  - opened file descriptor
 	 *  - task with enabled coverage (we can't unwire it from another task)
+	 *  - each code section for remote coverage collection
 	 */
 	refcount_t		refcount;
 	/* The lock protects mode, size, area and t. */
 	spinlock_t		lock;
 	enum kcov_mode		mode;
-	/* Size of arena (in long's for KCOV_MODE_TRACE). */
-	unsigned		size;
+	/* Size of arena (in long's). */
+	unsigned int		size;
 	/* Coverage buffer shared with user space. */
 	void			*area;
 	/* Task for which we collect coverage, or NULL. */
 	struct task_struct	*t;
+	/* Collecting coverage from remote (background) threads. */
+	bool			remote;
+	/* Size of remote area (in long's). */
+	unsigned int		remote_size;
+	/*
+	 * Sequence is incremented each time kcov is reenabled, used by
+	 * kcov_remote_stop(), see the comment there.
+	 */
+	int			sequence;
 };
 
+struct kcov_remote_area {
+	struct list_head	list;
+	unsigned int		size;
+};
+
+struct kcov_remote {
+	u64			handle;
+	struct kcov		*kcov;
+	struct hlist_node	hnode;
+};
+
+static DEFINE_SPINLOCK(kcov_remote_lock);
+static DEFINE_HASHTABLE(kcov_remote_map, 4);
+static struct list_head kcov_remote_areas = LIST_HEAD_INIT(kcov_remote_areas);
+
+struct kcov_percpu_data {
+	void			*irq_area;
+
+	unsigned int		saved_mode;
+	unsigned int		saved_size;
+	void			*saved_area;
+	struct kcov		*saved_kcov;
+	int			saved_sequence;
+};
+
+static DEFINE_PER_CPU(struct kcov_percpu_data, kcov_percpu_data);
+
+/* Must be called with kcov_remote_lock locked. */
+static struct kcov_remote *kcov_remote_find(u64 handle)
+{
+	struct kcov_remote *remote;
+
+	hash_for_each_possible(kcov_remote_map, remote, hnode, handle) {
+		if (remote->handle == handle)
+			return remote;
+	}
+	return NULL;
+}
+
+/* Must be called with kcov_remote_lock locked. */
+static struct kcov_remote *kcov_remote_add(struct kcov *kcov, u64 handle)
+{
+	struct kcov_remote *remote;
+
+	if (kcov_remote_find(handle))
+		return ERR_PTR(-EEXIST);
+	remote = kmalloc(sizeof(*remote), GFP_ATOMIC);
+	if (!remote)
+		return ERR_PTR(-ENOMEM);
+	remote->handle = handle;
+	remote->kcov = kcov;
+	hash_add(kcov_remote_map, &remote->hnode, handle);
+	return remote;
+}
+
+/* Must be called with kcov_remote_lock locked. */
+static struct kcov_remote_area *kcov_remote_area_get(unsigned int size)
+{
+	struct kcov_remote_area *area;
+	struct list_head *pos;
+
+	list_for_each(pos, &kcov_remote_areas) {
+		area = list_entry(pos, struct kcov_remote_area, list);
+		if (area->size == size) {
+			list_del(&area->list);
+			return area;
+		}
+	}
+	return NULL;
+}
+
+/* Must be called with kcov_remote_lock locked. */
+static void kcov_remote_area_put(struct kcov_remote_area *area,
+					unsigned int size)
+{
+	INIT_LIST_HEAD(&area->list);
+	area->size = size;
+	list_add(&area->list, &kcov_remote_areas);
+}
+
 static notrace bool check_kcov_mode(enum kcov_mode needed_mode, struct task_struct *t)
 {
 	unsigned int mode;
 
 	/*
 	 * We are interested in code coverage as a function of a syscall inputs,
-	 * so we ignore code executed in interrupts.
+	 * so we ignore code executed in interrupts, unless we are in a remote
+	 * coverage collection section in a softirq.
 	 */
-	if (!in_task())
+	if (!in_task() && !(in_serving_softirq() && t->kcov_softirq))
 		return false;
 	mode = READ_ONCE(t->kcov_mode);
 	/*
@@ -73,7 +168,7 @@
 	 * in_interrupt() returns false (e.g. preempt_schedule_irq()).
 	 * READ_ONCE()/barrier() effectively provides load-acquire wrt
 	 * interrupts, there are paired barrier()/WRITE_ONCE() in
-	 * kcov_ioctl_locked().
+	 * kcov_start().
 	 */
 	barrier();
 	return mode == needed_mode;
@@ -227,6 +322,80 @@
 EXPORT_SYMBOL(__sanitizer_cov_trace_switch);
 #endif /* ifdef CONFIG_KCOV_ENABLE_COMPARISONS */
 
+static void kcov_start(struct task_struct *t, struct kcov *kcov,
+			unsigned int size, void *area, enum kcov_mode mode,
+			int sequence)
+{
+	kcov_debug("t = %px, size = %u, area = %px\n", t, size, area);
+	t->kcov = kcov;
+	/* Cache in task struct for performance. */
+	t->kcov_size = size;
+	t->kcov_area = area;
+	t->kcov_sequence = sequence;
+	/* See comment in check_kcov_mode(). */
+	barrier();
+	WRITE_ONCE(t->kcov_mode, mode);
+}
+
+static void kcov_stop(struct task_struct *t)
+{
+	WRITE_ONCE(t->kcov_mode, KCOV_MODE_DISABLED);
+	barrier();
+	t->kcov = NULL;
+	t->kcov_size = 0;
+	t->kcov_area = NULL;
+}
+
+static void kcov_task_reset(struct task_struct *t)
+{
+	kcov_stop(t);
+	t->kcov_sequence = 0;
+	t->kcov_handle = 0;
+}
+
+void kcov_task_init(struct task_struct *t)
+{
+	kcov_task_reset(t);
+	t->kcov_handle = current->kcov_handle;
+}
+
+static void kcov_reset(struct kcov *kcov)
+{
+	kcov->t = NULL;
+	kcov->mode = KCOV_MODE_INIT;
+	kcov->remote = false;
+	kcov->remote_size = 0;
+	kcov->sequence++;
+}
+
+static void kcov_remote_reset(struct kcov *kcov)
+{
+	int bkt;
+	struct kcov_remote *remote;
+	struct hlist_node *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&kcov_remote_lock, flags);
+	hash_for_each_safe(kcov_remote_map, bkt, tmp, remote, hnode) {
+		if (remote->kcov != kcov)
+			continue;
+		hash_del(&remote->hnode);
+		kfree(remote);
+	}
+	/* Do reset before unlock to prevent races with kcov_remote_start(). */
+	kcov_reset(kcov);
+	spin_unlock_irqrestore(&kcov_remote_lock, flags);
+}
+
+static void kcov_disable(struct task_struct *t, struct kcov *kcov)
+{
+	kcov_task_reset(t);
+	if (kcov->remote)
+		kcov_remote_reset(kcov);
+	else
+		kcov_reset(kcov);
+}
+
 static void kcov_get(struct kcov *kcov)
 {
 	refcount_inc(&kcov->refcount);
@@ -235,37 +404,52 @@
 static void kcov_put(struct kcov *kcov)
 {
 	if (refcount_dec_and_test(&kcov->refcount)) {
+		kcov_remote_reset(kcov);
 		vfree(kcov->area);
 		kfree(kcov);
 	}
 }
 
-void kcov_task_init(struct task_struct *t)
-{
-	WRITE_ONCE(t->kcov_mode, KCOV_MODE_DISABLED);
-	barrier();
-	t->kcov_size = 0;
-	t->kcov_area = NULL;
-	t->kcov = NULL;
-}
-
 void kcov_task_exit(struct task_struct *t)
 {
 	struct kcov *kcov;
+	unsigned long flags;
 
 	kcov = t->kcov;
 	if (kcov == NULL)
 		return;
-	spin_lock(&kcov->lock);
+
+	spin_lock_irqsave(&kcov->lock, flags);
+	kcov_debug("t = %px, kcov->t = %px\n", t, kcov->t);
+	/*
+	 * For KCOV_ENABLE devices we want to make sure that t->kcov->t == t,
+	 * which comes down to:
+	 *        WARN_ON(!kcov->remote && kcov->t != t);
+	 *
+	 * For KCOV_REMOTE_ENABLE devices, the exiting task is either:
+	 *
+	 * 1. A remote task between kcov_remote_start() and kcov_remote_stop().
+	 *    In this case we should print a warning right away, since a task
+	 *    shouldn't be exiting when it's in a kcov coverage collection
+	 *    section. Here t points to the task that is collecting remote
+	 *    coverage, and t->kcov->t points to the thread that created the
+	 *    kcov device. Which means that to detect this case we need to
+	 *    check that t != t->kcov->t, and this gives us the following:
+	 *        WARN_ON(kcov->remote && kcov->t != t);
+	 *
+	 * 2. The task that created kcov exiting without calling KCOV_DISABLE,
+	 *    and then again we make sure that t->kcov->t == t:
+	 *        WARN_ON(kcov->remote && kcov->t != t);
+	 *
+	 * By combining all three checks into one we get:
+	 */
 	if (WARN_ON(kcov->t != t)) {
-		spin_unlock(&kcov->lock);
+		spin_unlock_irqrestore(&kcov->lock, flags);
 		return;
 	}
 	/* Just to not leave dangling references behind. */
-	kcov_task_init(t);
-	kcov->t = NULL;
-	kcov->mode = KCOV_MODE_INIT;
-	spin_unlock(&kcov->lock);
+	kcov_disable(t, kcov);
+	spin_unlock_irqrestore(&kcov->lock, flags);
 	kcov_put(kcov);
 }
 
@@ -276,12 +460,13 @@
 	struct kcov *kcov = vma->vm_file->private_data;
 	unsigned long size, off;
 	struct page *page;
+	unsigned long flags;
 
 	area = vmalloc_user(vma->vm_end - vma->vm_start);
 	if (!area)
 		return -ENOMEM;
 
-	spin_lock(&kcov->lock);
+	spin_lock_irqsave(&kcov->lock, flags);
 	size = kcov->size * sizeof(unsigned long);
 	if (kcov->mode != KCOV_MODE_INIT || vma->vm_pgoff != 0 ||
 	    vma->vm_end - vma->vm_start != size) {
@@ -291,7 +476,7 @@
 	if (!kcov->area) {
 		kcov->area = area;
 		vma->vm_flags |= VM_DONTEXPAND;
-		spin_unlock(&kcov->lock);
+		spin_unlock_irqrestore(&kcov->lock, flags);
 		for (off = 0; off < size; off += PAGE_SIZE) {
 			page = vmalloc_to_page(kcov->area + off);
 			if (vm_insert_page(vma, vma->vm_start + off, page))
@@ -300,7 +485,7 @@
 		return 0;
 	}
 exit:
-	spin_unlock(&kcov->lock);
+	spin_unlock_irqrestore(&kcov->lock, flags);
 	vfree(area);
 	return res;
 }
@@ -313,6 +498,7 @@
 	if (!kcov)
 		return -ENOMEM;
 	kcov->mode = KCOV_MODE_DISABLED;
+	kcov->sequence = 1;
 	refcount_set(&kcov->refcount, 1);
 	spin_lock_init(&kcov->lock);
 	filep->private_data = kcov;
@@ -325,6 +511,20 @@
 	return 0;
 }
 
+static int kcov_get_mode(unsigned long arg)
+{
+	if (arg == KCOV_TRACE_PC)
+		return KCOV_MODE_TRACE_PC;
+	else if (arg == KCOV_TRACE_CMP)
+#ifdef CONFIG_KCOV_ENABLE_COMPARISONS
+		return KCOV_MODE_TRACE_CMP;
+#else
+		return -ENOTSUPP;
+#endif
+	else
+		return -EINVAL;
+}
+
 /*
  * Fault in a lazily-faulted vmalloc area before it can be used by
  * __santizer_cov_trace_pc(), to avoid recursion issues if any code on the
@@ -340,11 +540,32 @@
 		READ_ONCE(area[offset]);
 }
 
+static inline bool kcov_check_handle(u64 handle, bool common_valid,
+				bool uncommon_valid, bool zero_valid)
+{
+	if (handle & ~(KCOV_SUBSYSTEM_MASK | KCOV_INSTANCE_MASK))
+		return false;
+	switch (handle & KCOV_SUBSYSTEM_MASK) {
+	case KCOV_SUBSYSTEM_COMMON:
+		return (handle & KCOV_INSTANCE_MASK) ?
+			common_valid : zero_valid;
+	case KCOV_SUBSYSTEM_USB:
+		return uncommon_valid;
+	default:
+		return false;
+	}
+	return false;
+}
+
 static int kcov_ioctl_locked(struct kcov *kcov, unsigned int cmd,
 			     unsigned long arg)
 {
 	struct task_struct *t;
 	unsigned long size, unused;
+	int mode, i;
+	struct kcov_remote_arg *remote_arg;
+	struct kcov_remote *remote;
+	unsigned long flags;
 
 	switch (cmd) {
 	case KCOV_INIT_TRACE:
@@ -378,26 +599,15 @@
 		t = current;
 		if (kcov->t != NULL || t->kcov != NULL)
 			return -EBUSY;
-		if (arg == KCOV_TRACE_PC)
-			kcov->mode = KCOV_MODE_TRACE_PC;
-		else if (arg == KCOV_TRACE_CMP)
-#ifdef CONFIG_KCOV_ENABLE_COMPARISONS
-			kcov->mode = KCOV_MODE_TRACE_CMP;
-#else
-		return -ENOTSUPP;
-#endif
-		else
-			return -EINVAL;
+		mode = kcov_get_mode(arg);
+		if (mode < 0)
+			return mode;
 		kcov_fault_in_area(kcov);
-		/* Cache in task struct for performance. */
-		t->kcov_size = kcov->size;
-		t->kcov_area = kcov->area;
-		/* See comment in check_kcov_mode(). */
-		barrier();
-		WRITE_ONCE(t->kcov_mode, kcov->mode);
-		t->kcov = kcov;
+		kcov->mode = mode;
+		kcov_start(t, kcov, kcov->size, kcov->area, kcov->mode,
+				kcov->sequence);
 		kcov->t = t;
-		/* This is put either in kcov_task_exit() or in KCOV_DISABLE. */
+		/* Put either in kcov_task_exit() or in KCOV_DISABLE. */
 		kcov_get(kcov);
 		return 0;
 	case KCOV_DISABLE:
@@ -408,11 +618,65 @@
 		t = current;
 		if (WARN_ON(kcov->t != t))
 			return -EINVAL;
-		kcov_task_init(t);
-		kcov->t = NULL;
-		kcov->mode = KCOV_MODE_INIT;
+		kcov_disable(t, kcov);
 		kcov_put(kcov);
 		return 0;
+	case KCOV_REMOTE_ENABLE:
+		if (kcov->mode != KCOV_MODE_INIT || !kcov->area)
+			return -EINVAL;
+		t = current;
+		if (kcov->t != NULL || t->kcov != NULL)
+			return -EBUSY;
+		remote_arg = (struct kcov_remote_arg *)arg;
+		mode = kcov_get_mode(remote_arg->trace_mode);
+		if (mode < 0)
+			return mode;
+		if (remote_arg->area_size > LONG_MAX / sizeof(unsigned long))
+			return -EINVAL;
+		kcov->mode = mode;
+		t->kcov = kcov;
+		kcov->t = t;
+		kcov->remote = true;
+		kcov->remote_size = remote_arg->area_size;
+		spin_lock_irqsave(&kcov_remote_lock, flags);
+		for (i = 0; i < remote_arg->num_handles; i++) {
+			if (!kcov_check_handle(remote_arg->handles[i],
+						false, true, false)) {
+				spin_unlock_irqrestore(&kcov_remote_lock,
+							flags);
+				kcov_disable(t, kcov);
+				return -EINVAL;
+			}
+			remote = kcov_remote_add(kcov, remote_arg->handles[i]);
+			if (IS_ERR(remote)) {
+				spin_unlock_irqrestore(&kcov_remote_lock,
+							flags);
+				kcov_disable(t, kcov);
+				return PTR_ERR(remote);
+			}
+		}
+		if (remote_arg->common_handle) {
+			if (!kcov_check_handle(remote_arg->common_handle,
+						true, false, false)) {
+				spin_unlock_irqrestore(&kcov_remote_lock,
+							flags);
+				kcov_disable(t, kcov);
+				return -EINVAL;
+			}
+			remote = kcov_remote_add(kcov,
+					remote_arg->common_handle);
+			if (IS_ERR(remote)) {
+				spin_unlock_irqrestore(&kcov_remote_lock,
+							flags);
+				kcov_disable(t, kcov);
+				return PTR_ERR(remote);
+			}
+			t->kcov_handle = remote_arg->common_handle;
+		}
+		spin_unlock_irqrestore(&kcov_remote_lock, flags);
+		/* Put either in kcov_task_exit() or in KCOV_DISABLE. */
+		kcov_get(kcov);
+		return 0;
 	default:
 		return -ENOTTY;
 	}
@@ -422,11 +686,36 @@
 {
 	struct kcov *kcov;
 	int res;
+	struct kcov_remote_arg *remote_arg = NULL;
+	unsigned int remote_num_handles;
+	unsigned long remote_arg_size;
+	unsigned long flags;
+
+	if (cmd == KCOV_REMOTE_ENABLE) {
+		if (get_user(remote_num_handles, (unsigned __user *)(arg +
+				offsetof(struct kcov_remote_arg, num_handles))))
+			return -EFAULT;
+		if (remote_num_handles > KCOV_REMOTE_MAX_HANDLES)
+			return -EINVAL;
+		remote_arg_size = struct_size(remote_arg, handles,
+					remote_num_handles);
+		remote_arg = memdup_user((void __user *)arg, remote_arg_size);
+		if (IS_ERR(remote_arg))
+			return PTR_ERR(remote_arg);
+		if (remote_arg->num_handles != remote_num_handles) {
+			kfree(remote_arg);
+			return -EINVAL;
+		}
+		arg = (unsigned long)remote_arg;
+	}
 
 	kcov = filep->private_data;
-	spin_lock(&kcov->lock);
+	spin_lock_irqsave(&kcov->lock, flags);
 	res = kcov_ioctl_locked(kcov, cmd, arg);
-	spin_unlock(&kcov->lock);
+	spin_unlock_irqrestore(&kcov->lock, flags);
+
+	kfree(remote_arg);
+
 	return res;
 }
 
@@ -438,8 +727,318 @@
 	.release        = kcov_close,
 };
 
+/*
+ * kcov_remote_start() and kcov_remote_stop() can be used to annotate a section
+ * of code in a kernel background thread or in a softirq to allow kcov to be
+ * used to collect coverage from that part of code.
+ *
+ * The handle argument of kcov_remote_start() identifies a code section that is
+ * used for coverage collection. A userspace process passes this handle to
+ * KCOV_REMOTE_ENABLE ioctl to make the used kcov device start collecting
+ * coverage for the code section identified by this handle.
+ *
+ * The usage of these annotations in the kernel code is different depending on
+ * the type of the kernel thread whose code is being annotated.
+ *
+ * For global kernel threads that are spawned in a limited number of instances
+ * (e.g. one USB hub_event() worker thread is spawned per USB HCD) and for
+ * softirqs, each instance must be assigned a unique 4-byte instance id. The
+ * instance id is then combined with a 1-byte subsystem id to get a handle via
+ * kcov_remote_handle(subsystem_id, instance_id).
+ *
+ * For local kernel threads that are spawned from system calls handler when a
+ * user interacts with some kernel interface (e.g. vhost workers), a handle is
+ * passed from a userspace process as the common_handle field of the
+ * kcov_remote_arg struct (note, that the user must generate a handle by using
+ * kcov_remote_handle() with KCOV_SUBSYSTEM_COMMON as the subsystem id and an
+ * arbitrary 4-byte non-zero number as the instance id). This common handle
+ * then gets saved into the task_struct of the process that issued the
+ * KCOV_REMOTE_ENABLE ioctl. When this process issues system calls that spawn
+ * kernel threads, the common handle must be retrieved via kcov_common_handle()
+ * and passed to the spawned threads via custom annotations. Those kernel
+ * threads must in turn be annotated with kcov_remote_start(common_handle) and
+ * kcov_remote_stop(). All of the threads that are spawned by the same process
+ * obtain the same handle, hence the name "common".
+ *
+ * See Documentation/dev-tools/kcov.rst for more details.
+ *
+ * Internally, kcov_remote_start() looks up the kcov device associated with the
+ * provided handle, allocates an area for coverage collection, and saves the
+ * pointers to kcov and area into the current task_struct to allow coverage to
+ * be collected via __sanitizer_cov_trace_pc().
+ * In turns kcov_remote_stop() clears those pointers from task_struct to stop
+ * collecting coverage and copies all collected coverage into the kcov area.
+ */
+
+static inline bool kcov_mode_enabled(unsigned int mode)
+{
+	return (mode & ~KCOV_IN_CTXSW) != KCOV_MODE_DISABLED;
+}
+
+static void kcov_remote_softirq_start(struct task_struct *t)
+{
+	struct kcov_percpu_data *data = this_cpu_ptr(&kcov_percpu_data);
+	unsigned int mode;
+
+	mode = READ_ONCE(t->kcov_mode);
+	barrier();
+	if (kcov_mode_enabled(mode)) {
+		data->saved_mode = mode;
+		data->saved_size = t->kcov_size;
+		data->saved_area = t->kcov_area;
+		data->saved_sequence = t->kcov_sequence;
+		data->saved_kcov = t->kcov;
+		kcov_stop(t);
+	}
+}
+
+static void kcov_remote_softirq_stop(struct task_struct *t)
+{
+	struct kcov_percpu_data *data = this_cpu_ptr(&kcov_percpu_data);
+
+	if (data->saved_kcov) {
+		kcov_start(t, data->saved_kcov, data->saved_size,
+				data->saved_area, data->saved_mode,
+				data->saved_sequence);
+		data->saved_mode = 0;
+		data->saved_size = 0;
+		data->saved_area = NULL;
+		data->saved_sequence = 0;
+		data->saved_kcov = NULL;
+	}
+}
+
+void kcov_remote_start(u64 handle)
+{
+	struct task_struct *t = current;
+	struct kcov_remote *remote;
+	struct kcov *kcov;
+	unsigned int mode;
+	void *area;
+	unsigned int size;
+	int sequence;
+	unsigned long flags;
+
+	if (WARN_ON(!kcov_check_handle(handle, true, true, true)))
+		return;
+	if (!in_task() && !in_serving_softirq())
+		return;
+
+	local_irq_save(flags);
+
+	/*
+	 * Check that kcov_remote_start() is not called twice in background
+	 * threads nor called by user tasks (with enabled kcov).
+	 */
+	mode = READ_ONCE(t->kcov_mode);
+	if (WARN_ON(in_task() && kcov_mode_enabled(mode))) {
+		local_irq_restore(flags);
+		return;
+	}
+	/*
+	 * Check that kcov_remote_start() is not called twice in softirqs.
+	 * Note, that kcov_remote_start() can be called from a softirq that
+	 * happened while collecting coverage from a background thread.
+	 */
+	if (WARN_ON(in_serving_softirq() && t->kcov_softirq)) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	spin_lock(&kcov_remote_lock);
+	remote = kcov_remote_find(handle);
+	if (!remote) {
+		spin_unlock_irqrestore(&kcov_remote_lock, flags);
+		return;
+	}
+	kcov_debug("handle = %llx, context: %s\n", handle,
+			in_task() ? "task" : "softirq");
+	kcov = remote->kcov;
+	/* Put in kcov_remote_stop(). */
+	kcov_get(kcov);
+	/*
+	 * Read kcov fields before unlock to prevent races with
+	 * KCOV_DISABLE / kcov_remote_reset().
+	 */
+	mode = kcov->mode;
+	sequence = kcov->sequence;
+	if (in_task()) {
+		size = kcov->remote_size;
+		area = kcov_remote_area_get(size);
+	} else {
+		size = CONFIG_KCOV_IRQ_AREA_SIZE;
+		area = this_cpu_ptr(&kcov_percpu_data)->irq_area;
+	}
+	spin_unlock_irqrestore(&kcov_remote_lock, flags);
+
+	/* Can only happen when in_task(). */
+	if (!area) {
+		area = vmalloc(size * sizeof(unsigned long));
+		if (!area) {
+			kcov_put(kcov);
+			return;
+		}
+	}
+
+	local_irq_save(flags);
+
+	/* Reset coverage size. */
+	*(u64 *)area = 0;
+
+	if (in_serving_softirq()) {
+		kcov_remote_softirq_start(t);
+		t->kcov_softirq = 1;
+	}
+	kcov_start(t, kcov, size, area, mode, sequence);
+
+	local_irq_restore(flags);
+
+}
+EXPORT_SYMBOL(kcov_remote_start);
+
+static void kcov_move_area(enum kcov_mode mode, void *dst_area,
+				unsigned int dst_area_size, void *src_area)
+{
+	u64 word_size = sizeof(unsigned long);
+	u64 count_size, entry_size_log;
+	u64 dst_len, src_len;
+	void *dst_entries, *src_entries;
+	u64 dst_occupied, dst_free, bytes_to_move, entries_moved;
+
+	kcov_debug("%px %u <= %px %lu\n",
+		dst_area, dst_area_size, src_area, *(unsigned long *)src_area);
+
+	switch (mode) {
+	case KCOV_MODE_TRACE_PC:
+		dst_len = READ_ONCE(*(unsigned long *)dst_area);
+		src_len = *(unsigned long *)src_area;
+		count_size = sizeof(unsigned long);
+		entry_size_log = __ilog2_u64(sizeof(unsigned long));
+		break;
+	case KCOV_MODE_TRACE_CMP:
+		dst_len = READ_ONCE(*(u64 *)dst_area);
+		src_len = *(u64 *)src_area;
+		count_size = sizeof(u64);
+		BUILD_BUG_ON(!is_power_of_2(KCOV_WORDS_PER_CMP));
+		entry_size_log = __ilog2_u64(sizeof(u64) * KCOV_WORDS_PER_CMP);
+		break;
+	default:
+		WARN_ON(1);
+		return;
+	}
+
+	/* As arm can't divide u64 integers use log of entry size. */
+	if (dst_len > ((dst_area_size * word_size - count_size) >>
+				entry_size_log))
+		return;
+	dst_occupied = count_size + (dst_len << entry_size_log);
+	dst_free = dst_area_size * word_size - dst_occupied;
+	bytes_to_move = min(dst_free, src_len << entry_size_log);
+	dst_entries = dst_area + dst_occupied;
+	src_entries = src_area + count_size;
+	memcpy(dst_entries, src_entries, bytes_to_move);
+	entries_moved = bytes_to_move >> entry_size_log;
+
+	switch (mode) {
+	case KCOV_MODE_TRACE_PC:
+		WRITE_ONCE(*(unsigned long *)dst_area, dst_len + entries_moved);
+		break;
+	case KCOV_MODE_TRACE_CMP:
+		WRITE_ONCE(*(u64 *)dst_area, dst_len + entries_moved);
+		break;
+	default:
+		break;
+	}
+}
+
+/* See the comment before kcov_remote_start() for usage details. */
+void kcov_remote_stop(void)
+{
+	struct task_struct *t = current;
+	struct kcov *kcov;
+	unsigned int mode;
+	void *area;
+	unsigned int size;
+	int sequence;
+	unsigned long flags;
+
+	if (!in_task() && !in_serving_softirq())
+		return;
+
+	local_irq_save(flags);
+
+	mode = READ_ONCE(t->kcov_mode);
+	barrier();
+	if (!kcov_mode_enabled(mode)) {
+		local_irq_restore(flags);
+		return;
+	}
+	/*
+	 * When in softirq, check if the corresponding kcov_remote_start()
+	 * actually found the remote handle and started collecting coverage.
+	 */
+	if (in_serving_softirq() && !t->kcov_softirq) {
+		local_irq_restore(flags);
+		return;
+	}
+	/* Make sure that kcov_softirq is only set when in softirq. */
+	if (WARN_ON(!in_serving_softirq() && t->kcov_softirq)) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	kcov = t->kcov;
+	area = t->kcov_area;
+	size = t->kcov_size;
+	sequence = t->kcov_sequence;
+
+	kcov_stop(t);
+	if (in_serving_softirq()) {
+		t->kcov_softirq = 0;
+		kcov_remote_softirq_stop(t);
+	}
+
+	spin_lock(&kcov->lock);
+	/*
+	 * KCOV_DISABLE could have been called between kcov_remote_start()
+	 * and kcov_remote_stop(), hence the sequence check.
+	 */
+	if (sequence == kcov->sequence && kcov->remote)
+		kcov_move_area(kcov->mode, kcov->area, kcov->size, area);
+	spin_unlock(&kcov->lock);
+
+	if (in_task()) {
+		spin_lock(&kcov_remote_lock);
+		kcov_remote_area_put(area, size);
+		spin_unlock(&kcov_remote_lock);
+	}
+
+	local_irq_restore(flags);
+
+	/* Get in kcov_remote_start(). */
+	kcov_put(kcov);
+}
+EXPORT_SYMBOL(kcov_remote_stop);
+
+/* See the comment before kcov_remote_start() for usage details. */
+u64 kcov_common_handle(void)
+{
+	return current->kcov_handle;
+}
+EXPORT_SYMBOL(kcov_common_handle);
+
 static int __init kcov_init(void)
 {
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		void *area = vmalloc(CONFIG_KCOV_IRQ_AREA_SIZE *
+				sizeof(unsigned long));
+		if (!area)
+			return -ENOMEM;
+		per_cpu_ptr(&kcov_percpu_data, cpu)->irq_area = area;
+	}
+
 	/*
 	 * The kcov debugfs file won't ever get removed and thus,
 	 * there is no need to protect it against removal races. The
diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile
new file mode 100644
index 0000000..65ca553
--- /dev/null
+++ b/kernel/kcsan/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+KCSAN_SANITIZE := n
+KCOV_INSTRUMENT := n
+UBSAN_SANITIZE := n
+
+CFLAGS_REMOVE_core.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_debugfs.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE)
+
+CFLAGS_core.o := $(call cc-option,-fno-conserve-stack) \
+	-fno-stack-protector -DDISABLE_BRANCH_PROFILING
+
+obj-y := core.o debugfs.o report.o
+obj-$(CONFIG_KCSAN_SELFTEST) += selftest.o
+
+CFLAGS_kcsan-test.o := $(CFLAGS_KCSAN) -g -fno-omit-frame-pointer
+obj-$(CONFIG_KCSAN_TEST) += kcsan-test.o
diff --git a/kernel/kcsan/atomic.h b/kernel/kcsan/atomic.h
new file mode 100644
index 0000000..75fe701
--- /dev/null
+++ b/kernel/kcsan/atomic.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _KERNEL_KCSAN_ATOMIC_H
+#define _KERNEL_KCSAN_ATOMIC_H
+
+#include <linux/types.h>
+
+/*
+ * Special rules for certain memory where concurrent conflicting accesses are
+ * common, however, the current convention is to not mark them; returns true if
+ * access to @ptr should be considered atomic. Called from slow-path.
+ */
+static bool kcsan_is_atomic_special(const volatile void *ptr)
+{
+	return false;
+}
+
+#endif /* _KERNEL_KCSAN_ATOMIC_H */
diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c
new file mode 100644
index 0000000..23e7acb
--- /dev/null
+++ b/kernel/kcsan/core.c
@@ -0,0 +1,1047 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "kcsan: " fmt
+
+#include <linux/atomic.h>
+#include <linux/bug.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/preempt.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+
+#include "atomic.h"
+#include "encoding.h"
+#include "kcsan.h"
+
+static bool kcsan_early_enable = IS_ENABLED(CONFIG_KCSAN_EARLY_ENABLE);
+unsigned int kcsan_udelay_task = CONFIG_KCSAN_UDELAY_TASK;
+unsigned int kcsan_udelay_interrupt = CONFIG_KCSAN_UDELAY_INTERRUPT;
+static long kcsan_skip_watch = CONFIG_KCSAN_SKIP_WATCH;
+static bool kcsan_interrupt_watcher = IS_ENABLED(CONFIG_KCSAN_INTERRUPT_WATCHER);
+
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "kcsan."
+module_param_named(early_enable, kcsan_early_enable, bool, 0);
+module_param_named(udelay_task, kcsan_udelay_task, uint, 0644);
+module_param_named(udelay_interrupt, kcsan_udelay_interrupt, uint, 0644);
+module_param_named(skip_watch, kcsan_skip_watch, long, 0644);
+module_param_named(interrupt_watcher, kcsan_interrupt_watcher, bool, 0444);
+
+bool kcsan_enabled;
+
+/* Per-CPU kcsan_ctx for interrupts */
+static DEFINE_PER_CPU(struct kcsan_ctx, kcsan_cpu_ctx) = {
+	.disable_count		= 0,
+	.atomic_next		= 0,
+	.atomic_nest_count	= 0,
+	.in_flat_atomic		= false,
+	.access_mask		= 0,
+	.scoped_accesses	= {LIST_POISON1, NULL},
+};
+
+/*
+ * Helper macros to index into adjacent slots, starting from address slot
+ * itself, followed by the right and left slots.
+ *
+ * The purpose is 2-fold:
+ *
+ *	1. if during insertion the address slot is already occupied, check if
+ *	   any adjacent slots are free;
+ *	2. accesses that straddle a slot boundary due to size that exceeds a
+ *	   slot's range may check adjacent slots if any watchpoint matches.
+ *
+ * Note that accesses with very large size may still miss a watchpoint; however,
+ * given this should be rare, this is a reasonable trade-off to make, since this
+ * will avoid:
+ *
+ *	1. excessive contention between watchpoint checks and setup;
+ *	2. larger number of simultaneous watchpoints without sacrificing
+ *	   performance.
+ *
+ * Example: SLOT_IDX values for KCSAN_CHECK_ADJACENT=1, where i is [0, 1, 2]:
+ *
+ *   slot=0:  [ 1,  2,  0]
+ *   slot=9:  [10, 11,  9]
+ *   slot=63: [64, 65, 63]
+ */
+#define SLOT_IDX(slot, i) (slot + ((i + KCSAN_CHECK_ADJACENT) % NUM_SLOTS))
+
+/*
+ * SLOT_IDX_FAST is used in the fast-path. Not first checking the address's primary
+ * slot (middle) is fine if we assume that races occur rarely. The set of
+ * indices {SLOT_IDX(slot, i) | i in [0, NUM_SLOTS)} is equivalent to
+ * {SLOT_IDX_FAST(slot, i) | i in [0, NUM_SLOTS)}.
+ */
+#define SLOT_IDX_FAST(slot, i) (slot + i)
+
+/*
+ * Watchpoints, with each entry encoded as defined in encoding.h: in order to be
+ * able to safely update and access a watchpoint without introducing locking
+ * overhead, we encode each watchpoint as a single atomic long. The initial
+ * zero-initialized state matches INVALID_WATCHPOINT.
+ *
+ * Add NUM_SLOTS-1 entries to account for overflow; this helps avoid having to
+ * use more complicated SLOT_IDX_FAST calculation with modulo in the fast-path.
+ */
+static atomic_long_t watchpoints[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS-1];
+
+/*
+ * Instructions to skip watching counter, used in should_watch(). We use a
+ * per-CPU counter to avoid excessive contention.
+ */
+static DEFINE_PER_CPU(long, kcsan_skip);
+
+/* For kcsan_prandom_u32_max(). */
+static DEFINE_PER_CPU(u32, kcsan_rand_state);
+
+static __always_inline atomic_long_t *find_watchpoint(unsigned long addr,
+						      size_t size,
+						      bool expect_write,
+						      long *encoded_watchpoint)
+{
+	const int slot = watchpoint_slot(addr);
+	const unsigned long addr_masked = addr & WATCHPOINT_ADDR_MASK;
+	atomic_long_t *watchpoint;
+	unsigned long wp_addr_masked;
+	size_t wp_size;
+	bool is_write;
+	int i;
+
+	BUILD_BUG_ON(CONFIG_KCSAN_NUM_WATCHPOINTS < NUM_SLOTS);
+
+	for (i = 0; i < NUM_SLOTS; ++i) {
+		watchpoint = &watchpoints[SLOT_IDX_FAST(slot, i)];
+		*encoded_watchpoint = atomic_long_read(watchpoint);
+		if (!decode_watchpoint(*encoded_watchpoint, &wp_addr_masked,
+				       &wp_size, &is_write))
+			continue;
+
+		if (expect_write && !is_write)
+			continue;
+
+		/* Check if the watchpoint matches the access. */
+		if (matching_access(wp_addr_masked, wp_size, addr_masked, size))
+			return watchpoint;
+	}
+
+	return NULL;
+}
+
+static inline atomic_long_t *
+insert_watchpoint(unsigned long addr, size_t size, bool is_write)
+{
+	const int slot = watchpoint_slot(addr);
+	const long encoded_watchpoint = encode_watchpoint(addr, size, is_write);
+	atomic_long_t *watchpoint;
+	int i;
+
+	/* Check slot index logic, ensuring we stay within array bounds. */
+	BUILD_BUG_ON(SLOT_IDX(0, 0) != KCSAN_CHECK_ADJACENT);
+	BUILD_BUG_ON(SLOT_IDX(0, KCSAN_CHECK_ADJACENT+1) != 0);
+	BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS-1, KCSAN_CHECK_ADJACENT) != ARRAY_SIZE(watchpoints)-1);
+	BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS-1, KCSAN_CHECK_ADJACENT+1) != ARRAY_SIZE(watchpoints) - NUM_SLOTS);
+
+	for (i = 0; i < NUM_SLOTS; ++i) {
+		long expect_val = INVALID_WATCHPOINT;
+
+		/* Try to acquire this slot. */
+		watchpoint = &watchpoints[SLOT_IDX(slot, i)];
+		if (atomic_long_try_cmpxchg_relaxed(watchpoint, &expect_val, encoded_watchpoint))
+			return watchpoint;
+	}
+
+	return NULL;
+}
+
+/*
+ * Return true if watchpoint was successfully consumed, false otherwise.
+ *
+ * This may return false if:
+ *
+ *	1. another thread already consumed the watchpoint;
+ *	2. the thread that set up the watchpoint already removed it;
+ *	3. the watchpoint was removed and then re-used.
+ */
+static __always_inline bool
+try_consume_watchpoint(atomic_long_t *watchpoint, long encoded_watchpoint)
+{
+	return atomic_long_try_cmpxchg_relaxed(watchpoint, &encoded_watchpoint, CONSUMED_WATCHPOINT);
+}
+
+/* Return true if watchpoint was not touched, false if already consumed. */
+static inline bool consume_watchpoint(atomic_long_t *watchpoint)
+{
+	return atomic_long_xchg_relaxed(watchpoint, CONSUMED_WATCHPOINT) != CONSUMED_WATCHPOINT;
+}
+
+/* Remove the watchpoint -- its slot may be reused after. */
+static inline void remove_watchpoint(atomic_long_t *watchpoint)
+{
+	atomic_long_set(watchpoint, INVALID_WATCHPOINT);
+}
+
+static __always_inline struct kcsan_ctx *get_ctx(void)
+{
+	/*
+	 * In interrupts, use raw_cpu_ptr to avoid unnecessary checks, that would
+	 * also result in calls that generate warnings in uaccess regions.
+	 */
+	return in_task() ? &current->kcsan_ctx : raw_cpu_ptr(&kcsan_cpu_ctx);
+}
+
+/* Check scoped accesses; never inline because this is a slow-path! */
+static noinline void kcsan_check_scoped_accesses(void)
+{
+	struct kcsan_ctx *ctx = get_ctx();
+	struct list_head *prev_save = ctx->scoped_accesses.prev;
+	struct kcsan_scoped_access *scoped_access;
+
+	ctx->scoped_accesses.prev = NULL;  /* Avoid recursion. */
+	list_for_each_entry(scoped_access, &ctx->scoped_accesses, list)
+		__kcsan_check_access(scoped_access->ptr, scoped_access->size, scoped_access->type);
+	ctx->scoped_accesses.prev = prev_save;
+}
+
+/* Rules for generic atomic accesses. Called from fast-path. */
+static __always_inline bool
+is_atomic(const volatile void *ptr, size_t size, int type, struct kcsan_ctx *ctx)
+{
+	if (type & KCSAN_ACCESS_ATOMIC)
+		return true;
+
+	/*
+	 * Unless explicitly declared atomic, never consider an assertion access
+	 * as atomic. This allows using them also in atomic regions, such as
+	 * seqlocks, without implicitly changing their semantics.
+	 */
+	if (type & KCSAN_ACCESS_ASSERT)
+		return false;
+
+	if (IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC) &&
+	    (type & KCSAN_ACCESS_WRITE) && size <= sizeof(long) &&
+	    !(type & KCSAN_ACCESS_COMPOUND) && IS_ALIGNED((unsigned long)ptr, size))
+		return true; /* Assume aligned writes up to word size are atomic. */
+
+	if (ctx->atomic_next > 0) {
+		/*
+		 * Because we do not have separate contexts for nested
+		 * interrupts, in case atomic_next is set, we simply assume that
+		 * the outer interrupt set atomic_next. In the worst case, we
+		 * will conservatively consider operations as atomic. This is a
+		 * reasonable trade-off to make, since this case should be
+		 * extremely rare; however, even if extremely rare, it could
+		 * lead to false positives otherwise.
+		 */
+		if ((hardirq_count() >> HARDIRQ_SHIFT) < 2)
+			--ctx->atomic_next; /* in task, or outer interrupt */
+		return true;
+	}
+
+	return ctx->atomic_nest_count > 0 || ctx->in_flat_atomic;
+}
+
+static __always_inline bool
+should_watch(const volatile void *ptr, size_t size, int type, struct kcsan_ctx *ctx)
+{
+	/*
+	 * Never set up watchpoints when memory operations are atomic.
+	 *
+	 * Need to check this first, before kcsan_skip check below: (1) atomics
+	 * should not count towards skipped instructions, and (2) to actually
+	 * decrement kcsan_atomic_next for consecutive instruction stream.
+	 */
+	if (is_atomic(ptr, size, type, ctx))
+		return false;
+
+	if (this_cpu_dec_return(kcsan_skip) >= 0)
+		return false;
+
+	/*
+	 * NOTE: If we get here, kcsan_skip must always be reset in slow path
+	 * via reset_kcsan_skip() to avoid underflow.
+	 */
+
+	/* this operation should be watched */
+	return true;
+}
+
+/*
+ * Returns a pseudo-random number in interval [0, ep_ro). Simple linear
+ * congruential generator, using constants from "Numerical Recipes".
+ */
+static u32 kcsan_prandom_u32_max(u32 ep_ro)
+{
+	u32 state = this_cpu_read(kcsan_rand_state);
+
+	state = 1664525 * state + 1013904223;
+	this_cpu_write(kcsan_rand_state, state);
+
+	return state % ep_ro;
+}
+
+static inline void reset_kcsan_skip(void)
+{
+	long skip_count = kcsan_skip_watch -
+			  (IS_ENABLED(CONFIG_KCSAN_SKIP_WATCH_RANDOMIZE) ?
+				   kcsan_prandom_u32_max(kcsan_skip_watch) :
+				   0);
+	this_cpu_write(kcsan_skip, skip_count);
+}
+
+static __always_inline bool kcsan_is_enabled(void)
+{
+	return READ_ONCE(kcsan_enabled) && get_ctx()->disable_count == 0;
+}
+
+/* Introduce delay depending on context and configuration. */
+static void delay_access(int type)
+{
+	unsigned int delay = in_task() ? kcsan_udelay_task : kcsan_udelay_interrupt;
+	/* For certain access types, skew the random delay to be longer. */
+	unsigned int skew_delay_order =
+		(type & (KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_ASSERT)) ? 1 : 0;
+
+	delay -= IS_ENABLED(CONFIG_KCSAN_DELAY_RANDOMIZE) ?
+			       kcsan_prandom_u32_max(delay >> skew_delay_order) :
+			       0;
+	udelay(delay);
+}
+
+void kcsan_save_irqtrace(struct task_struct *task)
+{
+#ifdef CONFIG_TRACE_IRQFLAGS
+	task->kcsan_save_irqtrace = task->irqtrace;
+#endif
+}
+
+void kcsan_restore_irqtrace(struct task_struct *task)
+{
+#ifdef CONFIG_TRACE_IRQFLAGS
+	task->irqtrace = task->kcsan_save_irqtrace;
+#endif
+}
+
+/*
+ * Pull everything together: check_access() below contains the performance
+ * critical operations; the fast-path (including check_access) functions should
+ * all be inlinable by the instrumentation functions.
+ *
+ * The slow-path (kcsan_found_watchpoint, kcsan_setup_watchpoint) are
+ * non-inlinable -- note that, we prefix these with "kcsan_" to ensure they can
+ * be filtered from the stacktrace, as well as give them unique names for the
+ * UACCESS whitelist of objtool. Each function uses user_access_save/restore(),
+ * since they do not access any user memory, but instrumentation is still
+ * emitted in UACCESS regions.
+ */
+
+static noinline void kcsan_found_watchpoint(const volatile void *ptr,
+					    size_t size,
+					    int type,
+					    atomic_long_t *watchpoint,
+					    long encoded_watchpoint)
+{
+	unsigned long flags;
+	bool consumed;
+
+	if (!kcsan_is_enabled())
+		return;
+
+	/*
+	 * The access_mask check relies on value-change comparison. To avoid
+	 * reporting a race where e.g. the writer set up the watchpoint, but the
+	 * reader has access_mask!=0, we have to ignore the found watchpoint.
+	 */
+	if (get_ctx()->access_mask != 0)
+		return;
+
+	/*
+	 * Consume the watchpoint as soon as possible, to minimize the chances
+	 * of !consumed. Consuming the watchpoint must always be guarded by
+	 * kcsan_is_enabled() check, as otherwise we might erroneously
+	 * triggering reports when disabled.
+	 */
+	consumed = try_consume_watchpoint(watchpoint, encoded_watchpoint);
+
+	/* keep this after try_consume_watchpoint */
+	flags = user_access_save();
+
+	if (consumed) {
+		kcsan_save_irqtrace(current);
+		kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_MAYBE,
+			     KCSAN_REPORT_CONSUMED_WATCHPOINT,
+			     watchpoint - watchpoints);
+		kcsan_restore_irqtrace(current);
+	} else {
+		/*
+		 * The other thread may not print any diagnostics, as it has
+		 * already removed the watchpoint, or another thread consumed
+		 * the watchpoint before this thread.
+		 */
+		atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_REPORT_RACES]);
+	}
+
+	if ((type & KCSAN_ACCESS_ASSERT) != 0)
+		atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_ASSERT_FAILURES]);
+	else
+		atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_DATA_RACES]);
+
+	user_access_restore(flags);
+}
+
+static noinline void
+kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type)
+{
+	const bool is_write = (type & KCSAN_ACCESS_WRITE) != 0;
+	const bool is_assert = (type & KCSAN_ACCESS_ASSERT) != 0;
+	atomic_long_t *watchpoint;
+	union {
+		u8 _1;
+		u16 _2;
+		u32 _4;
+		u64 _8;
+	} expect_value;
+	unsigned long access_mask;
+	enum kcsan_value_change value_change = KCSAN_VALUE_CHANGE_MAYBE;
+	unsigned long ua_flags = user_access_save();
+	unsigned long irq_flags = 0;
+
+	/*
+	 * Always reset kcsan_skip counter in slow-path to avoid underflow; see
+	 * should_watch().
+	 */
+	reset_kcsan_skip();
+
+	if (!kcsan_is_enabled())
+		goto out;
+
+	/*
+	 * Special atomic rules: unlikely to be true, so we check them here in
+	 * the slow-path, and not in the fast-path in is_atomic(). Call after
+	 * kcsan_is_enabled(), as we may access memory that is not yet
+	 * initialized during early boot.
+	 */
+	if (!is_assert && kcsan_is_atomic_special(ptr))
+		goto out;
+
+	if (!check_encodable((unsigned long)ptr, size)) {
+		atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_UNENCODABLE_ACCESSES]);
+		goto out;
+	}
+
+	/*
+	 * Save and restore the IRQ state trace touched by KCSAN, since KCSAN's
+	 * runtime is entered for every memory access, and potentially useful
+	 * information is lost if dirtied by KCSAN.
+	 */
+	kcsan_save_irqtrace(current);
+	if (!kcsan_interrupt_watcher)
+		local_irq_save(irq_flags);
+
+	watchpoint = insert_watchpoint((unsigned long)ptr, size, is_write);
+	if (watchpoint == NULL) {
+		/*
+		 * Out of capacity: the size of 'watchpoints', and the frequency
+		 * with which should_watch() returns true should be tweaked so
+		 * that this case happens very rarely.
+		 */
+		atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_NO_CAPACITY]);
+		goto out_unlock;
+	}
+
+	atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_SETUP_WATCHPOINTS]);
+	atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_USED_WATCHPOINTS]);
+
+	/*
+	 * Read the current value, to later check and infer a race if the data
+	 * was modified via a non-instrumented access, e.g. from a device.
+	 */
+	expect_value._8 = 0;
+	switch (size) {
+	case 1:
+		expect_value._1 = READ_ONCE(*(const u8 *)ptr);
+		break;
+	case 2:
+		expect_value._2 = READ_ONCE(*(const u16 *)ptr);
+		break;
+	case 4:
+		expect_value._4 = READ_ONCE(*(const u32 *)ptr);
+		break;
+	case 8:
+		expect_value._8 = READ_ONCE(*(const u64 *)ptr);
+		break;
+	default:
+		break; /* ignore; we do not diff the values */
+	}
+
+	if (IS_ENABLED(CONFIG_KCSAN_DEBUG)) {
+		kcsan_disable_current();
+		pr_err("watching %s, size: %zu, addr: %px [slot: %d, encoded: %lx]\n",
+		       is_write ? "write" : "read", size, ptr,
+		       watchpoint_slot((unsigned long)ptr),
+		       encode_watchpoint((unsigned long)ptr, size, is_write));
+		kcsan_enable_current();
+	}
+
+	/*
+	 * Delay this thread, to increase probability of observing a racy
+	 * conflicting access.
+	 */
+	delay_access(type);
+
+	/*
+	 * Re-read value, and check if it is as expected; if not, we infer a
+	 * racy access.
+	 */
+	access_mask = get_ctx()->access_mask;
+	switch (size) {
+	case 1:
+		expect_value._1 ^= READ_ONCE(*(const u8 *)ptr);
+		if (access_mask)
+			expect_value._1 &= (u8)access_mask;
+		break;
+	case 2:
+		expect_value._2 ^= READ_ONCE(*(const u16 *)ptr);
+		if (access_mask)
+			expect_value._2 &= (u16)access_mask;
+		break;
+	case 4:
+		expect_value._4 ^= READ_ONCE(*(const u32 *)ptr);
+		if (access_mask)
+			expect_value._4 &= (u32)access_mask;
+		break;
+	case 8:
+		expect_value._8 ^= READ_ONCE(*(const u64 *)ptr);
+		if (access_mask)
+			expect_value._8 &= (u64)access_mask;
+		break;
+	default:
+		break; /* ignore; we do not diff the values */
+	}
+
+	/* Were we able to observe a value-change? */
+	if (expect_value._8 != 0)
+		value_change = KCSAN_VALUE_CHANGE_TRUE;
+
+	/* Check if this access raced with another. */
+	if (!consume_watchpoint(watchpoint)) {
+		/*
+		 * Depending on the access type, map a value_change of MAYBE to
+		 * TRUE (always report) or FALSE (never report).
+		 */
+		if (value_change == KCSAN_VALUE_CHANGE_MAYBE) {
+			if (access_mask != 0) {
+				/*
+				 * For access with access_mask, we require a
+				 * value-change, as it is likely that races on
+				 * ~access_mask bits are expected.
+				 */
+				value_change = KCSAN_VALUE_CHANGE_FALSE;
+			} else if (size > 8 || is_assert) {
+				/* Always assume a value-change. */
+				value_change = KCSAN_VALUE_CHANGE_TRUE;
+			}
+		}
+
+		/*
+		 * No need to increment 'data_races' counter, as the racing
+		 * thread already did.
+		 *
+		 * Count 'assert_failures' for each failed ASSERT access,
+		 * therefore both this thread and the racing thread may
+		 * increment this counter.
+		 */
+		if (is_assert && value_change == KCSAN_VALUE_CHANGE_TRUE)
+			atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_ASSERT_FAILURES]);
+
+		kcsan_report(ptr, size, type, value_change, KCSAN_REPORT_RACE_SIGNAL,
+			     watchpoint - watchpoints);
+	} else if (value_change == KCSAN_VALUE_CHANGE_TRUE) {
+		/* Inferring a race, since the value should not have changed. */
+
+		atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN]);
+		if (is_assert)
+			atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_ASSERT_FAILURES]);
+
+		if (IS_ENABLED(CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN) || is_assert)
+			kcsan_report(ptr, size, type, KCSAN_VALUE_CHANGE_TRUE,
+				     KCSAN_REPORT_RACE_UNKNOWN_ORIGIN,
+				     watchpoint - watchpoints);
+	}
+
+	/*
+	 * Remove watchpoint; must be after reporting, since the slot may be
+	 * reused after this point.
+	 */
+	remove_watchpoint(watchpoint);
+	atomic_long_dec(&kcsan_counters[KCSAN_COUNTER_USED_WATCHPOINTS]);
+out_unlock:
+	if (!kcsan_interrupt_watcher)
+		local_irq_restore(irq_flags);
+	kcsan_restore_irqtrace(current);
+out:
+	user_access_restore(ua_flags);
+}
+
+static __always_inline void check_access(const volatile void *ptr, size_t size,
+					 int type)
+{
+	const bool is_write = (type & KCSAN_ACCESS_WRITE) != 0;
+	atomic_long_t *watchpoint;
+	long encoded_watchpoint;
+
+	/*
+	 * Do nothing for 0 sized check; this comparison will be optimized out
+	 * for constant sized instrumentation (__tsan_{read,write}N).
+	 */
+	if (unlikely(size == 0))
+		return;
+
+	/*
+	 * Avoid user_access_save in fast-path: find_watchpoint is safe without
+	 * user_access_save, as the address that ptr points to is only used to
+	 * check if a watchpoint exists; ptr is never dereferenced.
+	 */
+	watchpoint = find_watchpoint((unsigned long)ptr, size, !is_write,
+				     &encoded_watchpoint);
+	/*
+	 * It is safe to check kcsan_is_enabled() after find_watchpoint in the
+	 * slow-path, as long as no state changes that cause a race to be
+	 * detected and reported have occurred until kcsan_is_enabled() is
+	 * checked.
+	 */
+
+	if (unlikely(watchpoint != NULL))
+		kcsan_found_watchpoint(ptr, size, type, watchpoint,
+				       encoded_watchpoint);
+	else {
+		struct kcsan_ctx *ctx = get_ctx(); /* Call only once in fast-path. */
+
+		if (unlikely(should_watch(ptr, size, type, ctx)))
+			kcsan_setup_watchpoint(ptr, size, type);
+		else if (unlikely(ctx->scoped_accesses.prev))
+			kcsan_check_scoped_accesses();
+	}
+}
+
+/* === Public interface ===================================================== */
+
+void __init kcsan_init(void)
+{
+	int cpu;
+
+	BUG_ON(!in_task());
+
+	for_each_possible_cpu(cpu)
+		per_cpu(kcsan_rand_state, cpu) = (u32)get_cycles();
+
+	/*
+	 * We are in the init task, and no other tasks should be running;
+	 * WRITE_ONCE without memory barrier is sufficient.
+	 */
+	if (kcsan_early_enable) {
+		pr_info("enabled early\n");
+		WRITE_ONCE(kcsan_enabled, true);
+	}
+}
+
+/* === Exported interface =================================================== */
+
+void kcsan_disable_current(void)
+{
+	++get_ctx()->disable_count;
+}
+EXPORT_SYMBOL(kcsan_disable_current);
+
+void kcsan_enable_current(void)
+{
+	if (get_ctx()->disable_count-- == 0) {
+		/*
+		 * Warn if kcsan_enable_current() calls are unbalanced with
+		 * kcsan_disable_current() calls, which causes disable_count to
+		 * become negative and should not happen.
+		 */
+		kcsan_disable_current(); /* restore to 0, KCSAN still enabled */
+		kcsan_disable_current(); /* disable to generate warning */
+		WARN(1, "Unbalanced %s()", __func__);
+		kcsan_enable_current();
+	}
+}
+EXPORT_SYMBOL(kcsan_enable_current);
+
+void kcsan_enable_current_nowarn(void)
+{
+	if (get_ctx()->disable_count-- == 0)
+		kcsan_disable_current();
+}
+EXPORT_SYMBOL(kcsan_enable_current_nowarn);
+
+void kcsan_nestable_atomic_begin(void)
+{
+	/*
+	 * Do *not* check and warn if we are in a flat atomic region: nestable
+	 * and flat atomic regions are independent from each other.
+	 * See include/linux/kcsan.h: struct kcsan_ctx comments for more
+	 * comments.
+	 */
+
+	++get_ctx()->atomic_nest_count;
+}
+EXPORT_SYMBOL(kcsan_nestable_atomic_begin);
+
+void kcsan_nestable_atomic_end(void)
+{
+	if (get_ctx()->atomic_nest_count-- == 0) {
+		/*
+		 * Warn if kcsan_nestable_atomic_end() calls are unbalanced with
+		 * kcsan_nestable_atomic_begin() calls, which causes
+		 * atomic_nest_count to become negative and should not happen.
+		 */
+		kcsan_nestable_atomic_begin(); /* restore to 0 */
+		kcsan_disable_current(); /* disable to generate warning */
+		WARN(1, "Unbalanced %s()", __func__);
+		kcsan_enable_current();
+	}
+}
+EXPORT_SYMBOL(kcsan_nestable_atomic_end);
+
+void kcsan_flat_atomic_begin(void)
+{
+	get_ctx()->in_flat_atomic = true;
+}
+EXPORT_SYMBOL(kcsan_flat_atomic_begin);
+
+void kcsan_flat_atomic_end(void)
+{
+	get_ctx()->in_flat_atomic = false;
+}
+EXPORT_SYMBOL(kcsan_flat_atomic_end);
+
+void kcsan_atomic_next(int n)
+{
+	get_ctx()->atomic_next = n;
+}
+EXPORT_SYMBOL(kcsan_atomic_next);
+
+void kcsan_set_access_mask(unsigned long mask)
+{
+	get_ctx()->access_mask = mask;
+}
+EXPORT_SYMBOL(kcsan_set_access_mask);
+
+struct kcsan_scoped_access *
+kcsan_begin_scoped_access(const volatile void *ptr, size_t size, int type,
+			  struct kcsan_scoped_access *sa)
+{
+	struct kcsan_ctx *ctx = get_ctx();
+
+	__kcsan_check_access(ptr, size, type);
+
+	ctx->disable_count++; /* Disable KCSAN, in case list debugging is on. */
+
+	INIT_LIST_HEAD(&sa->list);
+	sa->ptr = ptr;
+	sa->size = size;
+	sa->type = type;
+
+	if (!ctx->scoped_accesses.prev) /* Lazy initialize list head. */
+		INIT_LIST_HEAD(&ctx->scoped_accesses);
+	list_add(&sa->list, &ctx->scoped_accesses);
+
+	ctx->disable_count--;
+	return sa;
+}
+EXPORT_SYMBOL(kcsan_begin_scoped_access);
+
+void kcsan_end_scoped_access(struct kcsan_scoped_access *sa)
+{
+	struct kcsan_ctx *ctx = get_ctx();
+
+	if (WARN(!ctx->scoped_accesses.prev, "Unbalanced %s()?", __func__))
+		return;
+
+	ctx->disable_count++; /* Disable KCSAN, in case list debugging is on. */
+
+	list_del(&sa->list);
+	if (list_empty(&ctx->scoped_accesses))
+		/*
+		 * Ensure we do not enter kcsan_check_scoped_accesses()
+		 * slow-path if unnecessary, and avoids requiring list_empty()
+		 * in the fast-path (to avoid a READ_ONCE() and potential
+		 * uaccess warning).
+		 */
+		ctx->scoped_accesses.prev = NULL;
+
+	ctx->disable_count--;
+
+	__kcsan_check_access(sa->ptr, sa->size, sa->type);
+}
+EXPORT_SYMBOL(kcsan_end_scoped_access);
+
+void __kcsan_check_access(const volatile void *ptr, size_t size, int type)
+{
+	check_access(ptr, size, type);
+}
+EXPORT_SYMBOL(__kcsan_check_access);
+
+/*
+ * KCSAN uses the same instrumentation that is emitted by supported compilers
+ * for ThreadSanitizer (TSAN).
+ *
+ * When enabled, the compiler emits instrumentation calls (the functions
+ * prefixed with "__tsan" below) for all loads and stores that it generated;
+ * inline asm is not instrumented.
+ *
+ * Note that, not all supported compiler versions distinguish aligned/unaligned
+ * accesses, but e.g. recent versions of Clang do. We simply alias the unaligned
+ * version to the generic version, which can handle both.
+ */
+
+#define DEFINE_TSAN_READ_WRITE(size)                                           \
+	void __tsan_read##size(void *ptr);                                     \
+	void __tsan_read##size(void *ptr)                                      \
+	{                                                                      \
+		check_access(ptr, size, 0);                                    \
+	}                                                                      \
+	EXPORT_SYMBOL(__tsan_read##size);                                      \
+	void __tsan_unaligned_read##size(void *ptr)                            \
+		__alias(__tsan_read##size);                                    \
+	EXPORT_SYMBOL(__tsan_unaligned_read##size);                            \
+	void __tsan_write##size(void *ptr);                                    \
+	void __tsan_write##size(void *ptr)                                     \
+	{                                                                      \
+		check_access(ptr, size, KCSAN_ACCESS_WRITE);                   \
+	}                                                                      \
+	EXPORT_SYMBOL(__tsan_write##size);                                     \
+	void __tsan_unaligned_write##size(void *ptr)                           \
+		__alias(__tsan_write##size);                                   \
+	EXPORT_SYMBOL(__tsan_unaligned_write##size);                           \
+	void __tsan_read_write##size(void *ptr);                               \
+	void __tsan_read_write##size(void *ptr)                                \
+	{                                                                      \
+		check_access(ptr, size,                                        \
+			     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE);      \
+	}                                                                      \
+	EXPORT_SYMBOL(__tsan_read_write##size);                                \
+	void __tsan_unaligned_read_write##size(void *ptr)                      \
+		__alias(__tsan_read_write##size);                              \
+	EXPORT_SYMBOL(__tsan_unaligned_read_write##size)
+
+DEFINE_TSAN_READ_WRITE(1);
+DEFINE_TSAN_READ_WRITE(2);
+DEFINE_TSAN_READ_WRITE(4);
+DEFINE_TSAN_READ_WRITE(8);
+DEFINE_TSAN_READ_WRITE(16);
+
+void __tsan_read_range(void *ptr, size_t size);
+void __tsan_read_range(void *ptr, size_t size)
+{
+	check_access(ptr, size, 0);
+}
+EXPORT_SYMBOL(__tsan_read_range);
+
+void __tsan_write_range(void *ptr, size_t size);
+void __tsan_write_range(void *ptr, size_t size)
+{
+	check_access(ptr, size, KCSAN_ACCESS_WRITE);
+}
+EXPORT_SYMBOL(__tsan_write_range);
+
+/*
+ * Use of explicit volatile is generally disallowed [1], however, volatile is
+ * still used in various concurrent context, whether in low-level
+ * synchronization primitives or for legacy reasons.
+ * [1] https://lwn.net/Articles/233479/
+ *
+ * We only consider volatile accesses atomic if they are aligned and would pass
+ * the size-check of compiletime_assert_rwonce_type().
+ */
+#define DEFINE_TSAN_VOLATILE_READ_WRITE(size)                                  \
+	void __tsan_volatile_read##size(void *ptr);                            \
+	void __tsan_volatile_read##size(void *ptr)                             \
+	{                                                                      \
+		const bool is_atomic = size <= sizeof(long long) &&            \
+				       IS_ALIGNED((unsigned long)ptr, size);   \
+		if (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS) && is_atomic)      \
+			return;                                                \
+		check_access(ptr, size, is_atomic ? KCSAN_ACCESS_ATOMIC : 0);  \
+	}                                                                      \
+	EXPORT_SYMBOL(__tsan_volatile_read##size);                             \
+	void __tsan_unaligned_volatile_read##size(void *ptr)                   \
+		__alias(__tsan_volatile_read##size);                           \
+	EXPORT_SYMBOL(__tsan_unaligned_volatile_read##size);                   \
+	void __tsan_volatile_write##size(void *ptr);                           \
+	void __tsan_volatile_write##size(void *ptr)                            \
+	{                                                                      \
+		const bool is_atomic = size <= sizeof(long long) &&            \
+				       IS_ALIGNED((unsigned long)ptr, size);   \
+		if (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS) && is_atomic)      \
+			return;                                                \
+		check_access(ptr, size,                                        \
+			     KCSAN_ACCESS_WRITE |                              \
+				     (is_atomic ? KCSAN_ACCESS_ATOMIC : 0));   \
+	}                                                                      \
+	EXPORT_SYMBOL(__tsan_volatile_write##size);                            \
+	void __tsan_unaligned_volatile_write##size(void *ptr)                  \
+		__alias(__tsan_volatile_write##size);                          \
+	EXPORT_SYMBOL(__tsan_unaligned_volatile_write##size)
+
+DEFINE_TSAN_VOLATILE_READ_WRITE(1);
+DEFINE_TSAN_VOLATILE_READ_WRITE(2);
+DEFINE_TSAN_VOLATILE_READ_WRITE(4);
+DEFINE_TSAN_VOLATILE_READ_WRITE(8);
+DEFINE_TSAN_VOLATILE_READ_WRITE(16);
+
+/*
+ * The below are not required by KCSAN, but can still be emitted by the
+ * compiler.
+ */
+void __tsan_func_entry(void *call_pc);
+void __tsan_func_entry(void *call_pc)
+{
+}
+EXPORT_SYMBOL(__tsan_func_entry);
+void __tsan_func_exit(void);
+void __tsan_func_exit(void)
+{
+}
+EXPORT_SYMBOL(__tsan_func_exit);
+void __tsan_init(void);
+void __tsan_init(void)
+{
+}
+EXPORT_SYMBOL(__tsan_init);
+
+/*
+ * Instrumentation for atomic builtins (__atomic_*, __sync_*).
+ *
+ * Normal kernel code _should not_ be using them directly, but some
+ * architectures may implement some or all atomics using the compilers'
+ * builtins.
+ *
+ * Note: If an architecture decides to fully implement atomics using the
+ * builtins, because they are implicitly instrumented by KCSAN (and KASAN,
+ * etc.), implementing the ARCH_ATOMIC interface (to get instrumentation via
+ * atomic-instrumented) is no longer necessary.
+ *
+ * TSAN instrumentation replaces atomic accesses with calls to any of the below
+ * functions, whose job is to also execute the operation itself.
+ */
+
+#define DEFINE_TSAN_ATOMIC_LOAD_STORE(bits)                                                        \
+	u##bits __tsan_atomic##bits##_load(const u##bits *ptr, int memorder);                      \
+	u##bits __tsan_atomic##bits##_load(const u##bits *ptr, int memorder)                       \
+	{                                                                                          \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE, KCSAN_ACCESS_ATOMIC);              \
+		}                                                                                  \
+		return __atomic_load_n(ptr, memorder);                                             \
+	}                                                                                          \
+	EXPORT_SYMBOL(__tsan_atomic##bits##_load);                                                 \
+	void __tsan_atomic##bits##_store(u##bits *ptr, u##bits v, int memorder);                   \
+	void __tsan_atomic##bits##_store(u##bits *ptr, u##bits v, int memorder)                    \
+	{                                                                                          \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC);                    \
+		}                                                                                  \
+		__atomic_store_n(ptr, v, memorder);                                                \
+	}                                                                                          \
+	EXPORT_SYMBOL(__tsan_atomic##bits##_store)
+
+#define DEFINE_TSAN_ATOMIC_RMW(op, bits, suffix)                                                   \
+	u##bits __tsan_atomic##bits##_##op(u##bits *ptr, u##bits v, int memorder);                 \
+	u##bits __tsan_atomic##bits##_##op(u##bits *ptr, u##bits v, int memorder)                  \
+	{                                                                                          \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE |                  \
+					     KCSAN_ACCESS_ATOMIC);                                 \
+		}                                                                                  \
+		return __atomic_##op##suffix(ptr, v, memorder);                                    \
+	}                                                                                          \
+	EXPORT_SYMBOL(__tsan_atomic##bits##_##op)
+
+/*
+ * Note: CAS operations are always classified as write, even in case they
+ * fail. We cannot perform check_access() after a write, as it might lead to
+ * false positives, in cases such as:
+ *
+ *	T0: __atomic_compare_exchange_n(&p->flag, &old, 1, ...)
+ *
+ *	T1: if (__atomic_load_n(&p->flag, ...)) {
+ *		modify *p;
+ *		p->flag = 0;
+ *	    }
+ *
+ * The only downside is that, if there are 3 threads, with one CAS that
+ * succeeds, another CAS that fails, and an unmarked racing operation, we may
+ * point at the wrong CAS as the source of the race. However, if we assume that
+ * all CAS can succeed in some other execution, the data race is still valid.
+ */
+#define DEFINE_TSAN_ATOMIC_CMPXCHG(bits, strength, weak)                                           \
+	int __tsan_atomic##bits##_compare_exchange_##strength(u##bits *ptr, u##bits *exp,          \
+							      u##bits val, int mo, int fail_mo);   \
+	int __tsan_atomic##bits##_compare_exchange_##strength(u##bits *ptr, u##bits *exp,          \
+							      u##bits val, int mo, int fail_mo)    \
+	{                                                                                          \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE |                  \
+					     KCSAN_ACCESS_ATOMIC);                                 \
+		}                                                                                  \
+		return __atomic_compare_exchange_n(ptr, exp, val, weak, mo, fail_mo);              \
+	}                                                                                          \
+	EXPORT_SYMBOL(__tsan_atomic##bits##_compare_exchange_##strength)
+
+#define DEFINE_TSAN_ATOMIC_CMPXCHG_VAL(bits)                                                       \
+	u##bits __tsan_atomic##bits##_compare_exchange_val(u##bits *ptr, u##bits exp, u##bits val, \
+							   int mo, int fail_mo);                   \
+	u##bits __tsan_atomic##bits##_compare_exchange_val(u##bits *ptr, u##bits exp, u##bits val, \
+							   int mo, int fail_mo)                    \
+	{                                                                                          \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE |                  \
+					     KCSAN_ACCESS_ATOMIC);                                 \
+		}                                                                                  \
+		__atomic_compare_exchange_n(ptr, &exp, val, 0, mo, fail_mo);                       \
+		return exp;                                                                        \
+	}                                                                                          \
+	EXPORT_SYMBOL(__tsan_atomic##bits##_compare_exchange_val)
+
+#define DEFINE_TSAN_ATOMIC_OPS(bits)                                                               \
+	DEFINE_TSAN_ATOMIC_LOAD_STORE(bits);                                                       \
+	DEFINE_TSAN_ATOMIC_RMW(exchange, bits, _n);                                                \
+	DEFINE_TSAN_ATOMIC_RMW(fetch_add, bits, );                                                 \
+	DEFINE_TSAN_ATOMIC_RMW(fetch_sub, bits, );                                                 \
+	DEFINE_TSAN_ATOMIC_RMW(fetch_and, bits, );                                                 \
+	DEFINE_TSAN_ATOMIC_RMW(fetch_or, bits, );                                                  \
+	DEFINE_TSAN_ATOMIC_RMW(fetch_xor, bits, );                                                 \
+	DEFINE_TSAN_ATOMIC_RMW(fetch_nand, bits, );                                                \
+	DEFINE_TSAN_ATOMIC_CMPXCHG(bits, strong, 0);                                               \
+	DEFINE_TSAN_ATOMIC_CMPXCHG(bits, weak, 1);                                                 \
+	DEFINE_TSAN_ATOMIC_CMPXCHG_VAL(bits)
+
+DEFINE_TSAN_ATOMIC_OPS(8);
+DEFINE_TSAN_ATOMIC_OPS(16);
+DEFINE_TSAN_ATOMIC_OPS(32);
+DEFINE_TSAN_ATOMIC_OPS(64);
+
+void __tsan_atomic_thread_fence(int memorder);
+void __tsan_atomic_thread_fence(int memorder)
+{
+	__atomic_thread_fence(memorder);
+}
+EXPORT_SYMBOL(__tsan_atomic_thread_fence);
+
+void __tsan_atomic_signal_fence(int memorder);
+void __tsan_atomic_signal_fence(int memorder) { }
+EXPORT_SYMBOL(__tsan_atomic_signal_fence);
diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
new file mode 100644
index 0000000..62a52be
--- /dev/null
+++ b/kernel/kcsan/debugfs.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "kcsan: " fmt
+
+#include <linux/atomic.h>
+#include <linux/bsearch.h>
+#include <linux/bug.h>
+#include <linux/debugfs.h>
+#include <linux/init.h>
+#include <linux/kallsyms.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+
+#include "kcsan.h"
+
+atomic_long_t kcsan_counters[KCSAN_COUNTER_COUNT];
+static const char *const counter_names[] = {
+	[KCSAN_COUNTER_USED_WATCHPOINTS]		= "used_watchpoints",
+	[KCSAN_COUNTER_SETUP_WATCHPOINTS]		= "setup_watchpoints",
+	[KCSAN_COUNTER_DATA_RACES]			= "data_races",
+	[KCSAN_COUNTER_ASSERT_FAILURES]			= "assert_failures",
+	[KCSAN_COUNTER_NO_CAPACITY]			= "no_capacity",
+	[KCSAN_COUNTER_REPORT_RACES]			= "report_races",
+	[KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN]		= "races_unknown_origin",
+	[KCSAN_COUNTER_UNENCODABLE_ACCESSES]		= "unencodable_accesses",
+	[KCSAN_COUNTER_ENCODING_FALSE_POSITIVES]	= "encoding_false_positives",
+};
+static_assert(ARRAY_SIZE(counter_names) == KCSAN_COUNTER_COUNT);
+
+/*
+ * Addresses for filtering functions from reporting. This list can be used as a
+ * whitelist or blacklist.
+ */
+static struct {
+	unsigned long	*addrs;		/* array of addresses */
+	size_t		size;		/* current size */
+	int		used;		/* number of elements used */
+	bool		sorted;		/* if elements are sorted */
+	bool		whitelist;	/* if list is a blacklist or whitelist */
+} report_filterlist = {
+	.addrs		= NULL,
+	.size		= 8,		/* small initial size */
+	.used		= 0,
+	.sorted		= false,
+	.whitelist	= false,	/* default is blacklist */
+};
+static DEFINE_SPINLOCK(report_filterlist_lock);
+
+/*
+ * The microbenchmark allows benchmarking KCSAN core runtime only. To run
+ * multiple threads, pipe 'microbench=<iters>' from multiple tasks into the
+ * debugfs file. This will not generate any conflicts, and tests fast-path only.
+ */
+static noinline void microbenchmark(unsigned long iters)
+{
+	const struct kcsan_ctx ctx_save = current->kcsan_ctx;
+	const bool was_enabled = READ_ONCE(kcsan_enabled);
+	cycles_t cycles;
+
+	/* We may have been called from an atomic region; reset context. */
+	memset(&current->kcsan_ctx, 0, sizeof(current->kcsan_ctx));
+	/*
+	 * Disable to benchmark fast-path for all accesses, and (expected
+	 * negligible) call into slow-path, but never set up watchpoints.
+	 */
+	WRITE_ONCE(kcsan_enabled, false);
+
+	pr_info("%s begin | iters: %lu\n", __func__, iters);
+
+	cycles = get_cycles();
+	while (iters--) {
+		unsigned long addr = iters & ((PAGE_SIZE << 8) - 1);
+		int type = !(iters & 0x7f) ? KCSAN_ACCESS_ATOMIC :
+				(!(iters & 0xf) ? KCSAN_ACCESS_WRITE : 0);
+		__kcsan_check_access((void *)addr, sizeof(long), type);
+	}
+	cycles = get_cycles() - cycles;
+
+	pr_info("%s end   | cycles: %llu\n", __func__, cycles);
+
+	WRITE_ONCE(kcsan_enabled, was_enabled);
+	/* restore context */
+	current->kcsan_ctx = ctx_save;
+}
+
+static int cmp_filterlist_addrs(const void *rhs, const void *lhs)
+{
+	const unsigned long a = *(const unsigned long *)rhs;
+	const unsigned long b = *(const unsigned long *)lhs;
+
+	return a < b ? -1 : a == b ? 0 : 1;
+}
+
+bool kcsan_skip_report_debugfs(unsigned long func_addr)
+{
+	unsigned long symbolsize, offset;
+	unsigned long flags;
+	bool ret = false;
+
+	if (!kallsyms_lookup_size_offset(func_addr, &symbolsize, &offset))
+		return false;
+	func_addr -= offset; /* Get function start */
+
+	spin_lock_irqsave(&report_filterlist_lock, flags);
+	if (report_filterlist.used == 0)
+		goto out;
+
+	/* Sort array if it is unsorted, and then do a binary search. */
+	if (!report_filterlist.sorted) {
+		sort(report_filterlist.addrs, report_filterlist.used,
+		     sizeof(unsigned long), cmp_filterlist_addrs, NULL);
+		report_filterlist.sorted = true;
+	}
+	ret = !!bsearch(&func_addr, report_filterlist.addrs,
+			report_filterlist.used, sizeof(unsigned long),
+			cmp_filterlist_addrs);
+	if (report_filterlist.whitelist)
+		ret = !ret;
+
+out:
+	spin_unlock_irqrestore(&report_filterlist_lock, flags);
+	return ret;
+}
+
+static void set_report_filterlist_whitelist(bool whitelist)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&report_filterlist_lock, flags);
+	report_filterlist.whitelist = whitelist;
+	spin_unlock_irqrestore(&report_filterlist_lock, flags);
+}
+
+/* Returns 0 on success, error-code otherwise. */
+static ssize_t insert_report_filterlist(const char *func)
+{
+	unsigned long flags;
+	unsigned long addr = kallsyms_lookup_name(func);
+	ssize_t ret = 0;
+
+	if (!addr) {
+		pr_err("could not find function: '%s'\n", func);
+		return -ENOENT;
+	}
+
+	spin_lock_irqsave(&report_filterlist_lock, flags);
+
+	if (report_filterlist.addrs == NULL) {
+		/* initial allocation */
+		report_filterlist.addrs =
+			kmalloc_array(report_filterlist.size,
+				      sizeof(unsigned long), GFP_ATOMIC);
+		if (report_filterlist.addrs == NULL) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	} else if (report_filterlist.used == report_filterlist.size) {
+		/* resize filterlist */
+		size_t new_size = report_filterlist.size * 2;
+		unsigned long *new_addrs =
+			krealloc(report_filterlist.addrs,
+				 new_size * sizeof(unsigned long), GFP_ATOMIC);
+
+		if (new_addrs == NULL) {
+			/* leave filterlist itself untouched */
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		report_filterlist.size = new_size;
+		report_filterlist.addrs = new_addrs;
+	}
+
+	/* Note: deduplicating should be done in userspace. */
+	report_filterlist.addrs[report_filterlist.used++] =
+		kallsyms_lookup_name(func);
+	report_filterlist.sorted = false;
+
+out:
+	spin_unlock_irqrestore(&report_filterlist_lock, flags);
+
+	return ret;
+}
+
+static int show_info(struct seq_file *file, void *v)
+{
+	int i;
+	unsigned long flags;
+
+	/* show stats */
+	seq_printf(file, "enabled: %i\n", READ_ONCE(kcsan_enabled));
+	for (i = 0; i < KCSAN_COUNTER_COUNT; ++i) {
+		seq_printf(file, "%s: %ld\n", counter_names[i],
+			   atomic_long_read(&kcsan_counters[i]));
+	}
+
+	/* show filter functions, and filter type */
+	spin_lock_irqsave(&report_filterlist_lock, flags);
+	seq_printf(file, "\n%s functions: %s\n",
+		   report_filterlist.whitelist ? "whitelisted" : "blacklisted",
+		   report_filterlist.used == 0 ? "none" : "");
+	for (i = 0; i < report_filterlist.used; ++i)
+		seq_printf(file, " %ps\n", (void *)report_filterlist.addrs[i]);
+	spin_unlock_irqrestore(&report_filterlist_lock, flags);
+
+	return 0;
+}
+
+static int debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, show_info, NULL);
+}
+
+static ssize_t
+debugfs_write(struct file *file, const char __user *buf, size_t count, loff_t *off)
+{
+	char kbuf[KSYM_NAME_LEN];
+	char *arg;
+	int read_len = count < (sizeof(kbuf) - 1) ? count : (sizeof(kbuf) - 1);
+
+	if (copy_from_user(kbuf, buf, read_len))
+		return -EFAULT;
+	kbuf[read_len] = '\0';
+	arg = strstrip(kbuf);
+
+	if (!strcmp(arg, "on")) {
+		WRITE_ONCE(kcsan_enabled, true);
+	} else if (!strcmp(arg, "off")) {
+		WRITE_ONCE(kcsan_enabled, false);
+	} else if (str_has_prefix(arg, "microbench=")) {
+		unsigned long iters;
+
+		if (kstrtoul(&arg[strlen("microbench=")], 0, &iters))
+			return -EINVAL;
+		microbenchmark(iters);
+	} else if (!strcmp(arg, "whitelist")) {
+		set_report_filterlist_whitelist(true);
+	} else if (!strcmp(arg, "blacklist")) {
+		set_report_filterlist_whitelist(false);
+	} else if (arg[0] == '!') {
+		ssize_t ret = insert_report_filterlist(&arg[1]);
+
+		if (ret < 0)
+			return ret;
+	} else {
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static const struct file_operations debugfs_ops =
+{
+	.read	 = seq_read,
+	.open	 = debugfs_open,
+	.write	 = debugfs_write,
+	.release = single_release
+};
+
+static int __init kcsan_debugfs_init(void)
+{
+	debugfs_create_file("kcsan", 0644, NULL, NULL, &debugfs_ops);
+	return 0;
+}
+
+late_initcall(kcsan_debugfs_init);
diff --git a/kernel/kcsan/encoding.h b/kernel/kcsan/encoding.h
new file mode 100644
index 0000000..1a6db2f
--- /dev/null
+++ b/kernel/kcsan/encoding.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _KERNEL_KCSAN_ENCODING_H
+#define _KERNEL_KCSAN_ENCODING_H
+
+#include <linux/bits.h>
+#include <linux/log2.h>
+#include <linux/mm.h>
+
+#include "kcsan.h"
+
+#define SLOT_RANGE PAGE_SIZE
+
+#define INVALID_WATCHPOINT  0
+#define CONSUMED_WATCHPOINT 1
+
+/*
+ * The maximum useful size of accesses for which we set up watchpoints is the
+ * max range of slots we check on an access.
+ */
+#define MAX_ENCODABLE_SIZE (SLOT_RANGE * (1 + KCSAN_CHECK_ADJACENT))
+
+/*
+ * Number of bits we use to store size info.
+ */
+#define WATCHPOINT_SIZE_BITS bits_per(MAX_ENCODABLE_SIZE)
+/*
+ * This encoding for addresses discards the upper (1 for is-write + SIZE_BITS);
+ * however, most 64-bit architectures do not use the full 64-bit address space.
+ * Also, in order for a false positive to be observable 2 things need to happen:
+ *
+ *	1. different addresses but with the same encoded address race;
+ *	2. and both map onto the same watchpoint slots;
+ *
+ * Both these are assumed to be very unlikely. However, in case it still
+ * happens, the report logic will filter out the false positive (see report.c).
+ */
+#define WATCHPOINT_ADDR_BITS (BITS_PER_LONG-1 - WATCHPOINT_SIZE_BITS)
+
+/*
+ * Masks to set/retrieve the encoded data.
+ */
+#define WATCHPOINT_WRITE_MASK BIT(BITS_PER_LONG-1)
+#define WATCHPOINT_SIZE_MASK                                                   \
+	GENMASK(BITS_PER_LONG-2, BITS_PER_LONG-2 - WATCHPOINT_SIZE_BITS)
+#define WATCHPOINT_ADDR_MASK                                                   \
+	GENMASK(BITS_PER_LONG-3 - WATCHPOINT_SIZE_BITS, 0)
+
+static inline bool check_encodable(unsigned long addr, size_t size)
+{
+	return size <= MAX_ENCODABLE_SIZE;
+}
+
+static inline long
+encode_watchpoint(unsigned long addr, size_t size, bool is_write)
+{
+	return (long)((is_write ? WATCHPOINT_WRITE_MASK : 0) |
+		      (size << WATCHPOINT_ADDR_BITS) |
+		      (addr & WATCHPOINT_ADDR_MASK));
+}
+
+static __always_inline bool decode_watchpoint(long watchpoint,
+					      unsigned long *addr_masked,
+					      size_t *size,
+					      bool *is_write)
+{
+	if (watchpoint == INVALID_WATCHPOINT ||
+	    watchpoint == CONSUMED_WATCHPOINT)
+		return false;
+
+	*addr_masked =    (unsigned long)watchpoint & WATCHPOINT_ADDR_MASK;
+	*size	     =   ((unsigned long)watchpoint & WATCHPOINT_SIZE_MASK) >> WATCHPOINT_ADDR_BITS;
+	*is_write    = !!((unsigned long)watchpoint & WATCHPOINT_WRITE_MASK);
+
+	return true;
+}
+
+/*
+ * Return watchpoint slot for an address.
+ */
+static __always_inline int watchpoint_slot(unsigned long addr)
+{
+	return (addr / PAGE_SIZE) % CONFIG_KCSAN_NUM_WATCHPOINTS;
+}
+
+static __always_inline bool matching_access(unsigned long addr1, size_t size1,
+					    unsigned long addr2, size_t size2)
+{
+	unsigned long end_range1 = addr1 + size1 - 1;
+	unsigned long end_range2 = addr2 + size2 - 1;
+
+	return addr1 <= end_range2 && addr2 <= end_range1;
+}
+
+#endif /* _KERNEL_KCSAN_ENCODING_H */
diff --git a/kernel/kcsan/kcsan-test.c b/kernel/kcsan/kcsan-test.c
new file mode 100644
index 0000000..ebe7fd2
--- /dev/null
+++ b/kernel/kcsan/kcsan-test.c
@@ -0,0 +1,1207 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KCSAN test with various race scenarious to test runtime behaviour. Since the
+ * interface with which KCSAN's reports are obtained is via the console, this is
+ * the output we should verify. For each test case checks the presence (or
+ * absence) of generated reports. Relies on 'console' tracepoint to capture
+ * reports as they appear in the kernel log.
+ *
+ * Makes use of KUnit for test organization, and the Torture framework for test
+ * thread control.
+ *
+ * Copyright (C) 2020, Google LLC.
+ * Author: Marco Elver <elver@google.com>
+ */
+
+#include <kunit/test.h>
+#include <linux/jiffies.h>
+#include <linux/kcsan-checks.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/seqlock.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/torture.h>
+#include <linux/tracepoint.h>
+#include <linux/types.h>
+#include <trace/events/printk.h>
+
+#ifdef CONFIG_CC_HAS_TSAN_COMPOUND_READ_BEFORE_WRITE
+#define __KCSAN_ACCESS_RW(alt) (KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE)
+#else
+#define __KCSAN_ACCESS_RW(alt) (alt)
+#endif
+
+/* Points to current test-case memory access "kernels". */
+static void (*access_kernels[2])(void);
+
+static struct task_struct **threads; /* Lists of threads. */
+static unsigned long end_time;       /* End time of test. */
+
+/* Report as observed from console. */
+static struct {
+	spinlock_t lock;
+	int nlines;
+	char lines[3][512];
+} observed = {
+	.lock = __SPIN_LOCK_UNLOCKED(observed.lock),
+};
+
+/* Setup test checking loop. */
+static __no_kcsan inline void
+begin_test_checks(void (*func1)(void), void (*func2)(void))
+{
+	kcsan_disable_current();
+
+	/*
+	 * Require at least as long as KCSAN_REPORT_ONCE_IN_MS, to ensure at
+	 * least one race is reported.
+	 */
+	end_time = jiffies + msecs_to_jiffies(CONFIG_KCSAN_REPORT_ONCE_IN_MS + 500);
+
+	/* Signal start; release potential initialization of shared data. */
+	smp_store_release(&access_kernels[0], func1);
+	smp_store_release(&access_kernels[1], func2);
+}
+
+/* End test checking loop. */
+static __no_kcsan inline bool
+end_test_checks(bool stop)
+{
+	if (!stop && time_before(jiffies, end_time)) {
+		/* Continue checking */
+		might_sleep();
+		return false;
+	}
+
+	kcsan_enable_current();
+	return true;
+}
+
+/*
+ * Probe for console output: checks if a race was reported, and obtains observed
+ * lines of interest.
+ */
+__no_kcsan
+static void probe_console(void *ignore, const char *buf, size_t len)
+{
+	unsigned long flags;
+	int nlines;
+
+	/*
+	 * Note that KCSAN reports under a global lock, so we do not risk the
+	 * possibility of having multiple reports interleaved. If that were the
+	 * case, we'd expect tests to fail.
+	 */
+
+	spin_lock_irqsave(&observed.lock, flags);
+	nlines = observed.nlines;
+
+	if (strnstr(buf, "BUG: KCSAN: ", len) && strnstr(buf, "test_", len)) {
+		/*
+		 * KCSAN report and related to the test.
+		 *
+		 * The provided @buf is not NUL-terminated; copy no more than
+		 * @len bytes and let strscpy() add the missing NUL-terminator.
+		 */
+		strscpy(observed.lines[0], buf, min(len + 1, sizeof(observed.lines[0])));
+		nlines = 1;
+	} else if ((nlines == 1 || nlines == 2) && strnstr(buf, "bytes by", len)) {
+		strscpy(observed.lines[nlines++], buf, min(len + 1, sizeof(observed.lines[0])));
+
+		if (strnstr(buf, "race at unknown origin", len)) {
+			if (WARN_ON(nlines != 2))
+				goto out;
+
+			/* No second line of interest. */
+			strcpy(observed.lines[nlines++], "<none>");
+		}
+	}
+
+out:
+	WRITE_ONCE(observed.nlines, nlines); /* Publish new nlines. */
+	spin_unlock_irqrestore(&observed.lock, flags);
+}
+
+/* Check if a report related to the test exists. */
+__no_kcsan
+static bool report_available(void)
+{
+	return READ_ONCE(observed.nlines) == ARRAY_SIZE(observed.lines);
+}
+
+/* Report information we expect in a report. */
+struct expect_report {
+	/* Access information of both accesses. */
+	struct {
+		void *fn;    /* Function pointer to expected function of top frame. */
+		void *addr;  /* Address of access; unchecked if NULL. */
+		size_t size; /* Size of access; unchecked if @addr is NULL. */
+		int type;    /* Access type, see KCSAN_ACCESS definitions. */
+	} access[2];
+};
+
+/* Check observed report matches information in @r. */
+__no_kcsan
+static bool report_matches(const struct expect_report *r)
+{
+	const bool is_assert = (r->access[0].type | r->access[1].type) & KCSAN_ACCESS_ASSERT;
+	bool ret = false;
+	unsigned long flags;
+	typeof(observed.lines) expect;
+	const char *end;
+	char *cur;
+	int i;
+
+	/* Doubled-checked locking. */
+	if (!report_available())
+		return false;
+
+	/* Generate expected report contents. */
+
+	/* Title */
+	cur = expect[0];
+	end = &expect[0][sizeof(expect[0]) - 1];
+	cur += scnprintf(cur, end - cur, "BUG: KCSAN: %s in ",
+			 is_assert ? "assert: race" : "data-race");
+	if (r->access[1].fn) {
+		char tmp[2][64];
+		int cmp;
+
+		/* Expect lexographically sorted function names in title. */
+		scnprintf(tmp[0], sizeof(tmp[0]), "%pS", r->access[0].fn);
+		scnprintf(tmp[1], sizeof(tmp[1]), "%pS", r->access[1].fn);
+		cmp = strcmp(tmp[0], tmp[1]);
+		cur += scnprintf(cur, end - cur, "%ps / %ps",
+				 cmp < 0 ? r->access[0].fn : r->access[1].fn,
+				 cmp < 0 ? r->access[1].fn : r->access[0].fn);
+	} else {
+		scnprintf(cur, end - cur, "%pS", r->access[0].fn);
+		/* The exact offset won't match, remove it. */
+		cur = strchr(expect[0], '+');
+		if (cur)
+			*cur = '\0';
+	}
+
+	/* Access 1 */
+	cur = expect[1];
+	end = &expect[1][sizeof(expect[1]) - 1];
+	if (!r->access[1].fn)
+		cur += scnprintf(cur, end - cur, "race at unknown origin, with ");
+
+	/* Access 1 & 2 */
+	for (i = 0; i < 2; ++i) {
+		const int ty = r->access[i].type;
+		const char *const access_type =
+			(ty & KCSAN_ACCESS_ASSERT) ?
+				      ((ty & KCSAN_ACCESS_WRITE) ?
+					       "assert no accesses" :
+					       "assert no writes") :
+				      ((ty & KCSAN_ACCESS_WRITE) ?
+					       ((ty & KCSAN_ACCESS_COMPOUND) ?
+							"read-write" :
+							"write") :
+					       "read");
+		const char *const access_type_aux =
+			(ty & KCSAN_ACCESS_ATOMIC) ?
+				      " (marked)" :
+				      ((ty & KCSAN_ACCESS_SCOPED) ? " (scoped)" : "");
+
+		if (i == 1) {
+			/* Access 2 */
+			cur = expect[2];
+			end = &expect[2][sizeof(expect[2]) - 1];
+
+			if (!r->access[1].fn) {
+				/* Dummy string if no second access is available. */
+				strcpy(cur, "<none>");
+				break;
+			}
+		}
+
+		cur += scnprintf(cur, end - cur, "%s%s to ", access_type,
+				 access_type_aux);
+
+		if (r->access[i].addr) /* Address is optional. */
+			cur += scnprintf(cur, end - cur, "0x%px of %zu bytes",
+					 r->access[i].addr, r->access[i].size);
+	}
+
+	spin_lock_irqsave(&observed.lock, flags);
+	if (!report_available())
+		goto out; /* A new report is being captured. */
+
+	/* Finally match expected output to what we actually observed. */
+	ret = strstr(observed.lines[0], expect[0]) &&
+	      /* Access info may appear in any order. */
+	      ((strstr(observed.lines[1], expect[1]) &&
+		strstr(observed.lines[2], expect[2])) ||
+	       (strstr(observed.lines[1], expect[2]) &&
+		strstr(observed.lines[2], expect[1])));
+out:
+	spin_unlock_irqrestore(&observed.lock, flags);
+	return ret;
+}
+
+/* ===== Test kernels ===== */
+
+static long test_sink;
+static long test_var;
+/* @test_array should be large enough to fall into multiple watchpoint slots. */
+static long test_array[3 * PAGE_SIZE / sizeof(long)];
+static struct {
+	long val[8];
+} test_struct;
+static DEFINE_SEQLOCK(test_seqlock);
+
+/*
+ * Helper to avoid compiler optimizing out reads, and to generate source values
+ * for writes.
+ */
+__no_kcsan
+static noinline void sink_value(long v) { WRITE_ONCE(test_sink, v); }
+
+static noinline void test_kernel_read(void) { sink_value(test_var); }
+
+static noinline void test_kernel_write(void)
+{
+	test_var = READ_ONCE_NOCHECK(test_sink) + 1;
+}
+
+static noinline void test_kernel_write_nochange(void) { test_var = 42; }
+
+/* Suffixed by value-change exception filter. */
+static noinline void test_kernel_write_nochange_rcu(void) { test_var = 42; }
+
+static noinline void test_kernel_read_atomic(void)
+{
+	sink_value(READ_ONCE(test_var));
+}
+
+static noinline void test_kernel_write_atomic(void)
+{
+	WRITE_ONCE(test_var, READ_ONCE_NOCHECK(test_sink) + 1);
+}
+
+static noinline void test_kernel_atomic_rmw(void)
+{
+	/* Use builtin, so we can set up the "bad" atomic/non-atomic scenario. */
+	__atomic_fetch_add(&test_var, 1, __ATOMIC_RELAXED);
+}
+
+__no_kcsan
+static noinline void test_kernel_write_uninstrumented(void) { test_var++; }
+
+static noinline void test_kernel_data_race(void) { data_race(test_var++); }
+
+static noinline void test_kernel_assert_writer(void)
+{
+	ASSERT_EXCLUSIVE_WRITER(test_var);
+}
+
+static noinline void test_kernel_assert_access(void)
+{
+	ASSERT_EXCLUSIVE_ACCESS(test_var);
+}
+
+#define TEST_CHANGE_BITS 0xff00ff00
+
+static noinline void test_kernel_change_bits(void)
+{
+	if (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {
+		/*
+		 * Avoid race of unknown origin for this test, just pretend they
+		 * are atomic.
+		 */
+		kcsan_nestable_atomic_begin();
+		test_var ^= TEST_CHANGE_BITS;
+		kcsan_nestable_atomic_end();
+	} else
+		WRITE_ONCE(test_var, READ_ONCE(test_var) ^ TEST_CHANGE_BITS);
+}
+
+static noinline void test_kernel_assert_bits_change(void)
+{
+	ASSERT_EXCLUSIVE_BITS(test_var, TEST_CHANGE_BITS);
+}
+
+static noinline void test_kernel_assert_bits_nochange(void)
+{
+	ASSERT_EXCLUSIVE_BITS(test_var, ~TEST_CHANGE_BITS);
+}
+
+/* To check that scoped assertions do trigger anywhere in scope. */
+static noinline void test_enter_scope(void)
+{
+	int x = 0;
+
+	/* Unrelated accesses to scoped assert. */
+	READ_ONCE(test_sink);
+	kcsan_check_read(&x, sizeof(x));
+}
+
+static noinline void test_kernel_assert_writer_scoped(void)
+{
+	ASSERT_EXCLUSIVE_WRITER_SCOPED(test_var);
+	test_enter_scope();
+}
+
+static noinline void test_kernel_assert_access_scoped(void)
+{
+	ASSERT_EXCLUSIVE_ACCESS_SCOPED(test_var);
+	test_enter_scope();
+}
+
+static noinline void test_kernel_rmw_array(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(test_array); ++i)
+		test_array[i]++;
+}
+
+static noinline void test_kernel_write_struct(void)
+{
+	kcsan_check_write(&test_struct, sizeof(test_struct));
+	kcsan_disable_current();
+	test_struct.val[3]++; /* induce value change */
+	kcsan_enable_current();
+}
+
+static noinline void test_kernel_write_struct_part(void)
+{
+	test_struct.val[3] = 42;
+}
+
+static noinline void test_kernel_read_struct_zero_size(void)
+{
+	kcsan_check_read(&test_struct.val[3], 0);
+}
+
+static noinline void test_kernel_jiffies_reader(void)
+{
+	sink_value((long)jiffies);
+}
+
+static noinline void test_kernel_seqlock_reader(void)
+{
+	unsigned int seq;
+
+	do {
+		seq = read_seqbegin(&test_seqlock);
+		sink_value(test_var);
+	} while (read_seqretry(&test_seqlock, seq));
+}
+
+static noinline void test_kernel_seqlock_writer(void)
+{
+	unsigned long flags;
+
+	write_seqlock_irqsave(&test_seqlock, flags);
+	test_var++;
+	write_sequnlock_irqrestore(&test_seqlock, flags);
+}
+
+static noinline void test_kernel_atomic_builtins(void)
+{
+	/*
+	 * Generate concurrent accesses, expecting no reports, ensuring KCSAN
+	 * treats builtin atomics as actually atomic.
+	 */
+	__atomic_load_n(&test_var, __ATOMIC_RELAXED);
+}
+
+/* ===== Test cases ===== */
+
+/* Simple test with normal data race. */
+__no_kcsan
+static void test_basic(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_write, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+		},
+	};
+	static const struct expect_report never = {
+		.access = {
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+		},
+	};
+	bool match_expect = false;
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_write, test_kernel_read);
+	do {
+		match_expect |= report_matches(&expect);
+		match_never = report_matches(&never);
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+/*
+ * Stress KCSAN with lots of concurrent races on different addresses until
+ * timeout.
+ */
+__no_kcsan
+static void test_concurrent_races(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			/* NULL will match any address. */
+			{ test_kernel_rmw_array, NULL, 0, __KCSAN_ACCESS_RW(KCSAN_ACCESS_WRITE) },
+			{ test_kernel_rmw_array, NULL, 0, __KCSAN_ACCESS_RW(0) },
+		},
+	};
+	static const struct expect_report never = {
+		.access = {
+			{ test_kernel_rmw_array, NULL, 0, 0 },
+			{ test_kernel_rmw_array, NULL, 0, 0 },
+		},
+	};
+	bool match_expect = false;
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_rmw_array, test_kernel_rmw_array);
+	do {
+		match_expect |= report_matches(&expect);
+		match_never |= report_matches(&never);
+	} while (!end_test_checks(false));
+	KUNIT_EXPECT_TRUE(test, match_expect); /* Sanity check matches exist. */
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+/* Test the KCSAN_REPORT_VALUE_CHANGE_ONLY option. */
+__no_kcsan
+static void test_novalue_change(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_write_nochange, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_write_nochange, test_kernel_read);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY))
+		KUNIT_EXPECT_FALSE(test, match_expect);
+	else
+		KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+/*
+ * Test that the rules where the KCSAN_REPORT_VALUE_CHANGE_ONLY option should
+ * never apply work.
+ */
+__no_kcsan
+static void test_novalue_change_exception(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_write_nochange_rcu, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_write_nochange_rcu, test_kernel_read);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+/* Test that data races of unknown origin are reported. */
+__no_kcsan
+static void test_unknown_origin(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+			{ NULL },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_write_uninstrumented, test_kernel_read);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	if (IS_ENABLED(CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN))
+		KUNIT_EXPECT_TRUE(test, match_expect);
+	else
+		KUNIT_EXPECT_FALSE(test, match_expect);
+}
+
+/* Test KCSAN_ASSUME_PLAIN_WRITES_ATOMIC if it is selected. */
+__no_kcsan
+static void test_write_write_assume_atomic(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_write, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+			{ test_kernel_write, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_write, test_kernel_write);
+	do {
+		sink_value(READ_ONCE(test_var)); /* induce value-change */
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	if (IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC))
+		KUNIT_EXPECT_FALSE(test, match_expect);
+	else
+		KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+/*
+ * Test that data races with writes larger than word-size are always reported,
+ * even if KCSAN_ASSUME_PLAIN_WRITES_ATOMIC is selected.
+ */
+__no_kcsan
+static void test_write_write_struct(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_write_struct, &test_struct, sizeof(test_struct), KCSAN_ACCESS_WRITE },
+			{ test_kernel_write_struct, &test_struct, sizeof(test_struct), KCSAN_ACCESS_WRITE },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_write_struct, test_kernel_write_struct);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+/*
+ * Test that data races where only one write is larger than word-size are always
+ * reported, even if KCSAN_ASSUME_PLAIN_WRITES_ATOMIC is selected.
+ */
+__no_kcsan
+static void test_write_write_struct_part(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_write_struct, &test_struct, sizeof(test_struct), KCSAN_ACCESS_WRITE },
+			{ test_kernel_write_struct_part, &test_struct.val[3], sizeof(test_struct.val[3]), KCSAN_ACCESS_WRITE },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_write_struct, test_kernel_write_struct_part);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+/* Test that races with atomic accesses never result in reports. */
+__no_kcsan
+static void test_read_atomic_write_atomic(struct kunit *test)
+{
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_read_atomic, test_kernel_write_atomic);
+	do {
+		match_never = report_available();
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+/* Test that a race with an atomic and plain access result in reports. */
+__no_kcsan
+static void test_read_plain_atomic_write(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+			{ test_kernel_write_atomic, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC },
+		},
+	};
+	bool match_expect = false;
+
+	if (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS))
+		return;
+
+	begin_test_checks(test_kernel_read, test_kernel_write_atomic);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+/* Test that atomic RMWs generate correct report. */
+__no_kcsan
+static void test_read_plain_atomic_rmw(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+			{ test_kernel_atomic_rmw, &test_var, sizeof(test_var),
+				KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC },
+		},
+	};
+	bool match_expect = false;
+
+	if (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS))
+		return;
+
+	begin_test_checks(test_kernel_read, test_kernel_atomic_rmw);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+/* Zero-sized accesses should never cause data race reports. */
+__no_kcsan
+static void test_zero_size_access(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_write_struct, &test_struct, sizeof(test_struct), KCSAN_ACCESS_WRITE },
+			{ test_kernel_write_struct, &test_struct, sizeof(test_struct), KCSAN_ACCESS_WRITE },
+		},
+	};
+	const struct expect_report never = {
+		.access = {
+			{ test_kernel_write_struct, &test_struct, sizeof(test_struct), KCSAN_ACCESS_WRITE },
+			{ test_kernel_read_struct_zero_size, &test_struct.val[3], 0, 0 },
+		},
+	};
+	bool match_expect = false;
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_write_struct, test_kernel_read_struct_zero_size);
+	do {
+		match_expect |= report_matches(&expect);
+		match_never = report_matches(&never);
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_TRUE(test, match_expect); /* Sanity check. */
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+/* Test the data_race() macro. */
+__no_kcsan
+static void test_data_race(struct kunit *test)
+{
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_data_race, test_kernel_data_race);
+	do {
+		match_never = report_available();
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+__no_kcsan
+static void test_assert_exclusive_writer(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_assert_writer, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT },
+			{ test_kernel_write_nochange, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_assert_writer, test_kernel_write_nochange);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+__no_kcsan
+static void test_assert_exclusive_access(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_assert_access, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE },
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_assert_access, test_kernel_read);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+__no_kcsan
+static void test_assert_exclusive_access_writer(struct kunit *test)
+{
+	const struct expect_report expect_access_writer = {
+		.access = {
+			{ test_kernel_assert_access, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE },
+			{ test_kernel_assert_writer, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT },
+		},
+	};
+	const struct expect_report expect_access_access = {
+		.access = {
+			{ test_kernel_assert_access, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE },
+			{ test_kernel_assert_access, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE },
+		},
+	};
+	const struct expect_report never = {
+		.access = {
+			{ test_kernel_assert_writer, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT },
+			{ test_kernel_assert_writer, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT },
+		},
+	};
+	bool match_expect_access_writer = false;
+	bool match_expect_access_access = false;
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_assert_access, test_kernel_assert_writer);
+	do {
+		match_expect_access_writer |= report_matches(&expect_access_writer);
+		match_expect_access_access |= report_matches(&expect_access_access);
+		match_never |= report_matches(&never);
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_TRUE(test, match_expect_access_writer);
+	KUNIT_EXPECT_TRUE(test, match_expect_access_access);
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+__no_kcsan
+static void test_assert_exclusive_bits_change(struct kunit *test)
+{
+	const struct expect_report expect = {
+		.access = {
+			{ test_kernel_assert_bits_change, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT },
+			{ test_kernel_change_bits, &test_var, sizeof(test_var),
+				KCSAN_ACCESS_WRITE | (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS) ? 0 : KCSAN_ACCESS_ATOMIC) },
+		},
+	};
+	bool match_expect = false;
+
+	begin_test_checks(test_kernel_assert_bits_change, test_kernel_change_bits);
+	do {
+		match_expect = report_matches(&expect);
+	} while (!end_test_checks(match_expect));
+	KUNIT_EXPECT_TRUE(test, match_expect);
+}
+
+__no_kcsan
+static void test_assert_exclusive_bits_nochange(struct kunit *test)
+{
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_assert_bits_nochange, test_kernel_change_bits);
+	do {
+		match_never = report_available();
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+__no_kcsan
+static void test_assert_exclusive_writer_scoped(struct kunit *test)
+{
+	const struct expect_report expect_start = {
+		.access = {
+			{ test_kernel_assert_writer_scoped, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_SCOPED },
+			{ test_kernel_write_nochange, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+		},
+	};
+	const struct expect_report expect_anywhere = {
+		.access = {
+			{ test_enter_scope, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_SCOPED },
+			{ test_kernel_write_nochange, &test_var, sizeof(test_var), KCSAN_ACCESS_WRITE },
+		},
+	};
+	bool match_expect_start = false;
+	bool match_expect_anywhere = false;
+
+	begin_test_checks(test_kernel_assert_writer_scoped, test_kernel_write_nochange);
+	do {
+		match_expect_start |= report_matches(&expect_start);
+		match_expect_anywhere |= report_matches(&expect_anywhere);
+	} while (!end_test_checks(match_expect_start && match_expect_anywhere));
+	KUNIT_EXPECT_TRUE(test, match_expect_start);
+	KUNIT_EXPECT_TRUE(test, match_expect_anywhere);
+}
+
+__no_kcsan
+static void test_assert_exclusive_access_scoped(struct kunit *test)
+{
+	const struct expect_report expect_start1 = {
+		.access = {
+			{ test_kernel_assert_access_scoped, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_SCOPED },
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+		},
+	};
+	const struct expect_report expect_start2 = {
+		.access = { expect_start1.access[0], expect_start1.access[0] },
+	};
+	const struct expect_report expect_inscope = {
+		.access = {
+			{ test_enter_scope, &test_var, sizeof(test_var), KCSAN_ACCESS_ASSERT | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_SCOPED },
+			{ test_kernel_read, &test_var, sizeof(test_var), 0 },
+		},
+	};
+	bool match_expect_start = false;
+	bool match_expect_inscope = false;
+
+	begin_test_checks(test_kernel_assert_access_scoped, test_kernel_read);
+	end_time += msecs_to_jiffies(1000); /* This test requires a bit more time. */
+	do {
+		match_expect_start |= report_matches(&expect_start1) || report_matches(&expect_start2);
+		match_expect_inscope |= report_matches(&expect_inscope);
+	} while (!end_test_checks(match_expect_start && match_expect_inscope));
+	KUNIT_EXPECT_TRUE(test, match_expect_start);
+	KUNIT_EXPECT_TRUE(test, match_expect_inscope);
+}
+
+/*
+ * jiffies is special (declared to be volatile) and its accesses are typically
+ * not marked; this test ensures that the compiler nor KCSAN gets confused about
+ * jiffies's declaration on different architectures.
+ */
+__no_kcsan
+static void test_jiffies_noreport(struct kunit *test)
+{
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_jiffies_reader, test_kernel_jiffies_reader);
+	do {
+		match_never = report_available();
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+/* Test that racing accesses in seqlock critical sections are not reported. */
+__no_kcsan
+static void test_seqlock_noreport(struct kunit *test)
+{
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_seqlock_reader, test_kernel_seqlock_writer);
+	do {
+		match_never = report_available();
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+/*
+ * Test atomic builtins work and required instrumentation functions exist. We
+ * also test that KCSAN understands they're atomic by racing with them via
+ * test_kernel_atomic_builtins(), and expect no reports.
+ *
+ * The atomic builtins _SHOULD NOT_ be used in normal kernel code!
+ */
+static void test_atomic_builtins(struct kunit *test)
+{
+	bool match_never = false;
+
+	begin_test_checks(test_kernel_atomic_builtins, test_kernel_atomic_builtins);
+	do {
+		long tmp;
+
+		kcsan_enable_current();
+
+		__atomic_store_n(&test_var, 42L, __ATOMIC_RELAXED);
+		KUNIT_EXPECT_EQ(test, 42L, __atomic_load_n(&test_var, __ATOMIC_RELAXED));
+
+		KUNIT_EXPECT_EQ(test, 42L, __atomic_exchange_n(&test_var, 20, __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, 20L, test_var);
+
+		tmp = 20L;
+		KUNIT_EXPECT_TRUE(test, __atomic_compare_exchange_n(&test_var, &tmp, 30L,
+								    0, __ATOMIC_RELAXED,
+								    __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, tmp, 20L);
+		KUNIT_EXPECT_EQ(test, test_var, 30L);
+		KUNIT_EXPECT_FALSE(test, __atomic_compare_exchange_n(&test_var, &tmp, 40L,
+								     1, __ATOMIC_RELAXED,
+								     __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, tmp, 30L);
+		KUNIT_EXPECT_EQ(test, test_var, 30L);
+
+		KUNIT_EXPECT_EQ(test, 30L, __atomic_fetch_add(&test_var, 1, __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, 31L, __atomic_fetch_sub(&test_var, 1, __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, 30L, __atomic_fetch_and(&test_var, 0xf, __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, 14L, __atomic_fetch_xor(&test_var, 0xf, __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, 1L, __atomic_fetch_or(&test_var, 0xf0, __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, 241L, __atomic_fetch_nand(&test_var, 0xf, __ATOMIC_RELAXED));
+		KUNIT_EXPECT_EQ(test, -2L, test_var);
+
+		__atomic_thread_fence(__ATOMIC_SEQ_CST);
+		__atomic_signal_fence(__ATOMIC_SEQ_CST);
+
+		kcsan_disable_current();
+
+		match_never = report_available();
+	} while (!end_test_checks(match_never));
+	KUNIT_EXPECT_FALSE(test, match_never);
+}
+
+/*
+ * Each test case is run with different numbers of threads. Until KUnit supports
+ * passing arguments for each test case, we encode #threads in the test case
+ * name (read by get_num_threads()). [The '-' was chosen as a stylistic
+ * preference to separate test name and #threads.]
+ *
+ * The thread counts are chosen to cover potentially interesting boundaries and
+ * corner cases (range 2-5), and then stress the system with larger counts.
+ */
+#define KCSAN_KUNIT_CASE(test_name)                                            \
+	{ .run_case = test_name, .name = #test_name "-02" },                   \
+	{ .run_case = test_name, .name = #test_name "-03" },                   \
+	{ .run_case = test_name, .name = #test_name "-04" },                   \
+	{ .run_case = test_name, .name = #test_name "-05" },                   \
+	{ .run_case = test_name, .name = #test_name "-08" },                   \
+	{ .run_case = test_name, .name = #test_name "-16" }
+
+static struct kunit_case kcsan_test_cases[] = {
+	KCSAN_KUNIT_CASE(test_basic),
+	KCSAN_KUNIT_CASE(test_concurrent_races),
+	KCSAN_KUNIT_CASE(test_novalue_change),
+	KCSAN_KUNIT_CASE(test_novalue_change_exception),
+	KCSAN_KUNIT_CASE(test_unknown_origin),
+	KCSAN_KUNIT_CASE(test_write_write_assume_atomic),
+	KCSAN_KUNIT_CASE(test_write_write_struct),
+	KCSAN_KUNIT_CASE(test_write_write_struct_part),
+	KCSAN_KUNIT_CASE(test_read_atomic_write_atomic),
+	KCSAN_KUNIT_CASE(test_read_plain_atomic_write),
+	KCSAN_KUNIT_CASE(test_read_plain_atomic_rmw),
+	KCSAN_KUNIT_CASE(test_zero_size_access),
+	KCSAN_KUNIT_CASE(test_data_race),
+	KCSAN_KUNIT_CASE(test_assert_exclusive_writer),
+	KCSAN_KUNIT_CASE(test_assert_exclusive_access),
+	KCSAN_KUNIT_CASE(test_assert_exclusive_access_writer),
+	KCSAN_KUNIT_CASE(test_assert_exclusive_bits_change),
+	KCSAN_KUNIT_CASE(test_assert_exclusive_bits_nochange),
+	KCSAN_KUNIT_CASE(test_assert_exclusive_writer_scoped),
+	KCSAN_KUNIT_CASE(test_assert_exclusive_access_scoped),
+	KCSAN_KUNIT_CASE(test_jiffies_noreport),
+	KCSAN_KUNIT_CASE(test_seqlock_noreport),
+	KCSAN_KUNIT_CASE(test_atomic_builtins),
+	{},
+};
+
+/* ===== End test cases ===== */
+
+/* Get number of threads encoded in test name. */
+static bool __no_kcsan
+get_num_threads(const char *test, int *nthreads)
+{
+	int len = strlen(test);
+
+	if (WARN_ON(len < 3))
+		return false;
+
+	*nthreads = test[len - 1] - '0';
+	*nthreads += (test[len - 2] - '0') * 10;
+
+	if (WARN_ON(*nthreads < 0))
+		return false;
+
+	return true;
+}
+
+/* Concurrent accesses from interrupts. */
+__no_kcsan
+static void access_thread_timer(struct timer_list *timer)
+{
+	static atomic_t cnt = ATOMIC_INIT(0);
+	unsigned int idx;
+	void (*func)(void);
+
+	idx = (unsigned int)atomic_inc_return(&cnt) % ARRAY_SIZE(access_kernels);
+	/* Acquire potential initialization. */
+	func = smp_load_acquire(&access_kernels[idx]);
+	if (func)
+		func();
+}
+
+/* The main loop for each thread. */
+__no_kcsan
+static int access_thread(void *arg)
+{
+	struct timer_list timer;
+	unsigned int cnt = 0;
+	unsigned int idx;
+	void (*func)(void);
+
+	timer_setup_on_stack(&timer, access_thread_timer, 0);
+	do {
+		might_sleep();
+
+		if (!timer_pending(&timer))
+			mod_timer(&timer, jiffies + 1);
+		else {
+			/* Iterate through all kernels. */
+			idx = cnt++ % ARRAY_SIZE(access_kernels);
+			/* Acquire potential initialization. */
+			func = smp_load_acquire(&access_kernels[idx]);
+			if (func)
+				func();
+		}
+	} while (!torture_must_stop());
+	del_timer_sync(&timer);
+	destroy_timer_on_stack(&timer);
+
+	torture_kthread_stopping("access_thread");
+	return 0;
+}
+
+__no_kcsan
+static int test_init(struct kunit *test)
+{
+	unsigned long flags;
+	int nthreads;
+	int i;
+
+	spin_lock_irqsave(&observed.lock, flags);
+	for (i = 0; i < ARRAY_SIZE(observed.lines); ++i)
+		observed.lines[i][0] = '\0';
+	observed.nlines = 0;
+	spin_unlock_irqrestore(&observed.lock, flags);
+
+	if (!torture_init_begin((char *)test->name, 1))
+		return -EBUSY;
+
+	if (!get_num_threads(test->name, &nthreads))
+		goto err;
+
+	if (WARN_ON(threads))
+		goto err;
+
+	for (i = 0; i < ARRAY_SIZE(access_kernels); ++i) {
+		if (WARN_ON(access_kernels[i]))
+			goto err;
+	}
+
+	if (!IS_ENABLED(CONFIG_PREEMPT) || !IS_ENABLED(CONFIG_KCSAN_INTERRUPT_WATCHER)) {
+		/*
+		 * Without any preemption, keep 2 CPUs free for other tasks, one
+		 * of which is the main test case function checking for
+		 * completion or failure.
+		 */
+		const int min_unused_cpus = IS_ENABLED(CONFIG_PREEMPT_NONE) ? 2 : 0;
+		const int min_required_cpus = 2 + min_unused_cpus;
+
+		if (num_online_cpus() < min_required_cpus) {
+			pr_err("%s: too few online CPUs (%u < %d) for test",
+			       test->name, num_online_cpus(), min_required_cpus);
+			goto err;
+		} else if (nthreads > num_online_cpus() - min_unused_cpus) {
+			nthreads = num_online_cpus() - min_unused_cpus;
+			pr_warn("%s: limiting number of threads to %d\n",
+				test->name, nthreads);
+		}
+	}
+
+	if (nthreads) {
+		threads = kcalloc(nthreads + 1, sizeof(struct task_struct *),
+				  GFP_KERNEL);
+		if (WARN_ON(!threads))
+			goto err;
+
+		threads[nthreads] = NULL;
+		for (i = 0; i < nthreads; ++i) {
+			if (torture_create_kthread(access_thread, NULL,
+						   threads[i]))
+				goto err;
+		}
+	}
+
+	torture_init_end();
+
+	return 0;
+
+err:
+	kfree(threads);
+	threads = NULL;
+	torture_init_end();
+	return -EINVAL;
+}
+
+__no_kcsan
+static void test_exit(struct kunit *test)
+{
+	struct task_struct **stop_thread;
+	int i;
+
+	if (torture_cleanup_begin())
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(access_kernels); ++i)
+		WRITE_ONCE(access_kernels[i], NULL);
+
+	if (threads) {
+		for (stop_thread = threads; *stop_thread; stop_thread++)
+			torture_stop_kthread(reader_thread, *stop_thread);
+
+		kfree(threads);
+		threads = NULL;
+	}
+
+	torture_cleanup_end();
+}
+
+static struct kunit_suite kcsan_test_suite = {
+	.name = "kcsan-test",
+	.test_cases = kcsan_test_cases,
+	.init = test_init,
+	.exit = test_exit,
+};
+static struct kunit_suite *kcsan_test_suites[] = { &kcsan_test_suite, NULL };
+
+__no_kcsan
+static void register_tracepoints(struct tracepoint *tp, void *ignore)
+{
+	check_trace_callback_type_console(probe_console);
+	if (!strcmp(tp->name, "console"))
+		WARN_ON(tracepoint_probe_register(tp, probe_console, NULL));
+}
+
+__no_kcsan
+static void unregister_tracepoints(struct tracepoint *tp, void *ignore)
+{
+	if (!strcmp(tp->name, "console"))
+		tracepoint_probe_unregister(tp, probe_console, NULL);
+}
+
+/*
+ * We only want to do tracepoints setup and teardown once, therefore we have to
+ * customize the init and exit functions and cannot rely on kunit_test_suite().
+ */
+static int __init kcsan_test_init(void)
+{
+	/*
+	 * Because we want to be able to build the test as a module, we need to
+	 * iterate through all known tracepoints, since the static registration
+	 * won't work here.
+	 */
+	for_each_kernel_tracepoint(register_tracepoints, NULL);
+	return __kunit_test_suites_init(kcsan_test_suites);
+}
+
+static void kcsan_test_exit(void)
+{
+	__kunit_test_suites_exit(kcsan_test_suites);
+	for_each_kernel_tracepoint(unregister_tracepoints, NULL);
+	tracepoint_synchronize_unregister();
+}
+
+late_initcall(kcsan_test_init);
+module_exit(kcsan_test_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Marco Elver <elver@google.com>");
diff --git a/kernel/kcsan/kcsan.h b/kernel/kcsan/kcsan.h
new file mode 100644
index 0000000..87ccdb3
--- /dev/null
+++ b/kernel/kcsan/kcsan.h
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. For more info please
+ * see Documentation/dev-tools/kcsan.rst.
+ */
+
+#ifndef _KERNEL_KCSAN_KCSAN_H
+#define _KERNEL_KCSAN_KCSAN_H
+
+#include <linux/atomic.h>
+#include <linux/kcsan.h>
+#include <linux/sched.h>
+
+/* The number of adjacent watchpoints to check. */
+#define KCSAN_CHECK_ADJACENT 1
+#define NUM_SLOTS (1 + 2*KCSAN_CHECK_ADJACENT)
+
+extern unsigned int kcsan_udelay_task;
+extern unsigned int kcsan_udelay_interrupt;
+
+/*
+ * Globally enable and disable KCSAN.
+ */
+extern bool kcsan_enabled;
+
+/*
+ * Save/restore IRQ flags state trace dirtied by KCSAN.
+ */
+void kcsan_save_irqtrace(struct task_struct *task);
+void kcsan_restore_irqtrace(struct task_struct *task);
+
+/*
+ * Statistics counters displayed via debugfs; should only be modified in
+ * slow-paths.
+ */
+enum kcsan_counter_id {
+	/*
+	 * Number of watchpoints currently in use.
+	 */
+	KCSAN_COUNTER_USED_WATCHPOINTS,
+
+	/*
+	 * Total number of watchpoints set up.
+	 */
+	KCSAN_COUNTER_SETUP_WATCHPOINTS,
+
+	/*
+	 * Total number of data races.
+	 */
+	KCSAN_COUNTER_DATA_RACES,
+
+	/*
+	 * Total number of ASSERT failures due to races. If the observed race is
+	 * due to two conflicting ASSERT type accesses, then both will be
+	 * counted.
+	 */
+	KCSAN_COUNTER_ASSERT_FAILURES,
+
+	/*
+	 * Number of times no watchpoints were available.
+	 */
+	KCSAN_COUNTER_NO_CAPACITY,
+
+	/*
+	 * A thread checking a watchpoint raced with another checking thread;
+	 * only one will be reported.
+	 */
+	KCSAN_COUNTER_REPORT_RACES,
+
+	/*
+	 * Observed data value change, but writer thread unknown.
+	 */
+	KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN,
+
+	/*
+	 * The access cannot be encoded to a valid watchpoint.
+	 */
+	KCSAN_COUNTER_UNENCODABLE_ACCESSES,
+
+	/*
+	 * Watchpoint encoding caused a watchpoint to fire on mismatching
+	 * accesses.
+	 */
+	KCSAN_COUNTER_ENCODING_FALSE_POSITIVES,
+
+	KCSAN_COUNTER_COUNT, /* number of counters */
+};
+extern atomic_long_t kcsan_counters[KCSAN_COUNTER_COUNT];
+
+/*
+ * Returns true if data races in the function symbol that maps to func_addr
+ * (offsets are ignored) should *not* be reported.
+ */
+extern bool kcsan_skip_report_debugfs(unsigned long func_addr);
+
+/*
+ * Value-change states.
+ */
+enum kcsan_value_change {
+	/*
+	 * Did not observe a value-change, however, it is valid to report the
+	 * race, depending on preferences.
+	 */
+	KCSAN_VALUE_CHANGE_MAYBE,
+
+	/*
+	 * Did not observe a value-change, and it is invalid to report the race.
+	 */
+	KCSAN_VALUE_CHANGE_FALSE,
+
+	/*
+	 * The value was observed to change, and the race should be reported.
+	 */
+	KCSAN_VALUE_CHANGE_TRUE,
+};
+
+enum kcsan_report_type {
+	/*
+	 * The thread that set up the watchpoint and briefly stalled was
+	 * signalled that another thread triggered the watchpoint.
+	 */
+	KCSAN_REPORT_RACE_SIGNAL,
+
+	/*
+	 * A thread found and consumed a matching watchpoint.
+	 */
+	KCSAN_REPORT_CONSUMED_WATCHPOINT,
+
+	/*
+	 * No other thread was observed to race with the access, but the data
+	 * value before and after the stall differs.
+	 */
+	KCSAN_REPORT_RACE_UNKNOWN_ORIGIN,
+};
+
+/*
+ * Print a race report from thread that encountered the race.
+ */
+extern void kcsan_report(const volatile void *ptr, size_t size, int access_type,
+			 enum kcsan_value_change value_change,
+			 enum kcsan_report_type type, int watchpoint_idx);
+
+#endif /* _KERNEL_KCSAN_KCSAN_H */
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
new file mode 100644
index 0000000..d3bf87e
--- /dev/null
+++ b/kernel/kcsan/report.c
@@ -0,0 +1,642 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/debug_locks.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/lockdep.h>
+#include <linux/preempt.h>
+#include <linux/printk.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/stacktrace.h>
+
+#include "kcsan.h"
+#include "encoding.h"
+
+/*
+ * Max. number of stack entries to show in the report.
+ */
+#define NUM_STACK_ENTRIES 64
+
+/* Common access info. */
+struct access_info {
+	const volatile void	*ptr;
+	size_t			size;
+	int			access_type;
+	int			task_pid;
+	int			cpu_id;
+};
+
+/*
+ * Other thread info: communicated from other racing thread to thread that set
+ * up the watchpoint, which then prints the complete report atomically.
+ */
+struct other_info {
+	struct access_info	ai;
+	unsigned long		stack_entries[NUM_STACK_ENTRIES];
+	int			num_stack_entries;
+
+	/*
+	 * Optionally pass @current. Typically we do not need to pass @current
+	 * via @other_info since just @task_pid is sufficient. Passing @current
+	 * has additional overhead.
+	 *
+	 * To safely pass @current, we must either use get_task_struct/
+	 * put_task_struct, or stall the thread that populated @other_info.
+	 *
+	 * We cannot rely on get_task_struct/put_task_struct in case
+	 * release_report() races with a task being released, and would have to
+	 * free it in release_report(). This may result in deadlock if we want
+	 * to use KCSAN on the allocators.
+	 *
+	 * Since we also want to reliably print held locks for
+	 * CONFIG_KCSAN_VERBOSE, the current implementation stalls the thread
+	 * that populated @other_info until it has been consumed.
+	 */
+	struct task_struct	*task;
+};
+
+/*
+ * To never block any producers of struct other_info, we need as many elements
+ * as we have watchpoints (upper bound on concurrent races to report).
+ */
+static struct other_info other_infos[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS-1];
+
+/*
+ * Information about reported races; used to rate limit reporting.
+ */
+struct report_time {
+	/*
+	 * The last time the race was reported.
+	 */
+	unsigned long time;
+
+	/*
+	 * The frames of the 2 threads; if only 1 thread is known, one frame
+	 * will be 0.
+	 */
+	unsigned long frame1;
+	unsigned long frame2;
+};
+
+/*
+ * Since we also want to be able to debug allocators with KCSAN, to avoid
+ * deadlock, report_times cannot be dynamically resized with krealloc in
+ * rate_limit_report.
+ *
+ * Therefore, we use a fixed-size array, which at most will occupy a page. This
+ * still adequately rate limits reports, assuming that a) number of unique data
+ * races is not excessive, and b) occurrence of unique races within the
+ * same time window is limited.
+ */
+#define REPORT_TIMES_MAX (PAGE_SIZE / sizeof(struct report_time))
+#define REPORT_TIMES_SIZE                                                      \
+	(CONFIG_KCSAN_REPORT_ONCE_IN_MS > REPORT_TIMES_MAX ?                   \
+		 REPORT_TIMES_MAX :                                            \
+		 CONFIG_KCSAN_REPORT_ONCE_IN_MS)
+static struct report_time report_times[REPORT_TIMES_SIZE];
+
+/*
+ * Spinlock serializing report generation, and access to @other_infos. Although
+ * it could make sense to have a finer-grained locking story for @other_infos,
+ * report generation needs to be serialized either way, so not much is gained.
+ */
+static DEFINE_RAW_SPINLOCK(report_lock);
+
+/*
+ * Checks if the race identified by thread frames frame1 and frame2 has
+ * been reported since (now - KCSAN_REPORT_ONCE_IN_MS).
+ */
+static bool rate_limit_report(unsigned long frame1, unsigned long frame2)
+{
+	struct report_time *use_entry = &report_times[0];
+	unsigned long invalid_before;
+	int i;
+
+	BUILD_BUG_ON(CONFIG_KCSAN_REPORT_ONCE_IN_MS != 0 && REPORT_TIMES_SIZE == 0);
+
+	if (CONFIG_KCSAN_REPORT_ONCE_IN_MS == 0)
+		return false;
+
+	invalid_before = jiffies - msecs_to_jiffies(CONFIG_KCSAN_REPORT_ONCE_IN_MS);
+
+	/* Check if a matching race report exists. */
+	for (i = 0; i < REPORT_TIMES_SIZE; ++i) {
+		struct report_time *rt = &report_times[i];
+
+		/*
+		 * Must always select an entry for use to store info as we
+		 * cannot resize report_times; at the end of the scan, use_entry
+		 * will be the oldest entry, which ideally also happened before
+		 * KCSAN_REPORT_ONCE_IN_MS ago.
+		 */
+		if (time_before(rt->time, use_entry->time))
+			use_entry = rt;
+
+		/*
+		 * Initially, no need to check any further as this entry as well
+		 * as following entries have never been used.
+		 */
+		if (rt->time == 0)
+			break;
+
+		/* Check if entry expired. */
+		if (time_before(rt->time, invalid_before))
+			continue; /* before KCSAN_REPORT_ONCE_IN_MS ago */
+
+		/* Reported recently, check if race matches. */
+		if ((rt->frame1 == frame1 && rt->frame2 == frame2) ||
+		    (rt->frame1 == frame2 && rt->frame2 == frame1))
+			return true;
+	}
+
+	use_entry->time = jiffies;
+	use_entry->frame1 = frame1;
+	use_entry->frame2 = frame2;
+	return false;
+}
+
+/*
+ * Special rules to skip reporting.
+ */
+static bool
+skip_report(enum kcsan_value_change value_change, unsigned long top_frame)
+{
+	/* Should never get here if value_change==FALSE. */
+	WARN_ON_ONCE(value_change == KCSAN_VALUE_CHANGE_FALSE);
+
+	/*
+	 * The first call to skip_report always has value_change==TRUE, since we
+	 * cannot know the value written of an instrumented access. For the 2nd
+	 * call there are 6 cases with CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY:
+	 *
+	 * 1. read watchpoint, conflicting write (value_change==TRUE): report;
+	 * 2. read watchpoint, conflicting write (value_change==MAYBE): skip;
+	 * 3. write watchpoint, conflicting write (value_change==TRUE): report;
+	 * 4. write watchpoint, conflicting write (value_change==MAYBE): skip;
+	 * 5. write watchpoint, conflicting read (value_change==MAYBE): skip;
+	 * 6. write watchpoint, conflicting read (value_change==TRUE): report;
+	 *
+	 * Cases 1-4 are intuitive and expected; case 5 ensures we do not report
+	 * data races where the write may have rewritten the same value; case 6
+	 * is possible either if the size is larger than what we check value
+	 * changes for or the access type is KCSAN_ACCESS_ASSERT.
+	 */
+	if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) &&
+	    value_change == KCSAN_VALUE_CHANGE_MAYBE) {
+		/*
+		 * The access is a write, but the data value did not change.
+		 *
+		 * We opt-out of this filter for certain functions at request of
+		 * maintainers.
+		 */
+		char buf[64];
+		int len = scnprintf(buf, sizeof(buf), "%ps", (void *)top_frame);
+
+		if (!strnstr(buf, "rcu_", len) &&
+		    !strnstr(buf, "_rcu", len) &&
+		    !strnstr(buf, "_srcu", len))
+			return true;
+	}
+
+	return kcsan_skip_report_debugfs(top_frame);
+}
+
+static const char *get_access_type(int type)
+{
+	if (type & KCSAN_ACCESS_ASSERT) {
+		if (type & KCSAN_ACCESS_SCOPED) {
+			if (type & KCSAN_ACCESS_WRITE)
+				return "assert no accesses (scoped)";
+			else
+				return "assert no writes (scoped)";
+		} else {
+			if (type & KCSAN_ACCESS_WRITE)
+				return "assert no accesses";
+			else
+				return "assert no writes";
+		}
+	}
+
+	switch (type) {
+	case 0:
+		return "read";
+	case KCSAN_ACCESS_ATOMIC:
+		return "read (marked)";
+	case KCSAN_ACCESS_WRITE:
+		return "write";
+	case KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC:
+		return "write (marked)";
+	case KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE:
+		return "read-write";
+	case KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC:
+		return "read-write (marked)";
+	case KCSAN_ACCESS_SCOPED:
+		return "read (scoped)";
+	case KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_ATOMIC:
+		return "read (marked, scoped)";
+	case KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_WRITE:
+		return "write (scoped)";
+	case KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC:
+		return "write (marked, scoped)";
+	default:
+		BUG();
+	}
+}
+
+static const char *get_bug_type(int type)
+{
+	return (type & KCSAN_ACCESS_ASSERT) != 0 ? "assert: race" : "data-race";
+}
+
+/* Return thread description: in task or interrupt. */
+static const char *get_thread_desc(int task_id)
+{
+	if (task_id != -1) {
+		static char buf[32]; /* safe: protected by report_lock */
+
+		snprintf(buf, sizeof(buf), "task %i", task_id);
+		return buf;
+	}
+	return "interrupt";
+}
+
+/* Helper to skip KCSAN-related functions in stack-trace. */
+static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries)
+{
+	char buf[64];
+	char *cur;
+	int len, skip;
+
+	for (skip = 0; skip < num_entries; ++skip) {
+		len = scnprintf(buf, sizeof(buf), "%ps", (void *)stack_entries[skip]);
+
+		/* Never show tsan_* or {read,write}_once_size. */
+		if (strnstr(buf, "tsan_", len) ||
+		    strnstr(buf, "_once_size", len))
+			continue;
+
+		cur = strnstr(buf, "kcsan_", len);
+		if (cur) {
+			cur += strlen("kcsan_");
+			if (!str_has_prefix(cur, "test"))
+				continue; /* KCSAN runtime function. */
+			/* KCSAN related test. */
+		}
+
+		/*
+		 * No match for runtime functions -- @skip entries to skip to
+		 * get to first frame of interest.
+		 */
+		break;
+	}
+
+	return skip;
+}
+
+/* Compares symbolized strings of addr1 and addr2. */
+static int sym_strcmp(void *addr1, void *addr2)
+{
+	char buf1[64];
+	char buf2[64];
+
+	snprintf(buf1, sizeof(buf1), "%pS", addr1);
+	snprintf(buf2, sizeof(buf2), "%pS", addr2);
+
+	return strncmp(buf1, buf2, sizeof(buf1));
+}
+
+static void print_verbose_info(struct task_struct *task)
+{
+	if (!task)
+		return;
+
+	/* Restore IRQ state trace for printing. */
+	kcsan_restore_irqtrace(task);
+
+	pr_err("\n");
+	debug_show_held_locks(task);
+	print_irqtrace_events(task);
+}
+
+/*
+ * Returns true if a report was generated, false otherwise.
+ */
+static bool print_report(enum kcsan_value_change value_change,
+			 enum kcsan_report_type type,
+			 const struct access_info *ai,
+			 const struct other_info *other_info)
+{
+	unsigned long stack_entries[NUM_STACK_ENTRIES] = { 0 };
+	int num_stack_entries = stack_trace_save(stack_entries, NUM_STACK_ENTRIES, 1);
+	int skipnr = get_stack_skipnr(stack_entries, num_stack_entries);
+	unsigned long this_frame = stack_entries[skipnr];
+	unsigned long other_frame = 0;
+	int other_skipnr = 0; /* silence uninit warnings */
+
+	/*
+	 * Must check report filter rules before starting to print.
+	 */
+	if (skip_report(KCSAN_VALUE_CHANGE_TRUE, stack_entries[skipnr]))
+		return false;
+
+	if (type == KCSAN_REPORT_RACE_SIGNAL) {
+		other_skipnr = get_stack_skipnr(other_info->stack_entries,
+						other_info->num_stack_entries);
+		other_frame = other_info->stack_entries[other_skipnr];
+
+		/* @value_change is only known for the other thread */
+		if (skip_report(value_change, other_frame))
+			return false;
+	}
+
+	if (rate_limit_report(this_frame, other_frame))
+		return false;
+
+	/* Print report header. */
+	pr_err("==================================================================\n");
+	switch (type) {
+	case KCSAN_REPORT_RACE_SIGNAL: {
+		int cmp;
+
+		/*
+		 * Order functions lexographically for consistent bug titles.
+		 * Do not print offset of functions to keep title short.
+		 */
+		cmp = sym_strcmp((void *)other_frame, (void *)this_frame);
+		pr_err("BUG: KCSAN: %s in %ps / %ps\n",
+		       get_bug_type(ai->access_type | other_info->ai.access_type),
+		       (void *)(cmp < 0 ? other_frame : this_frame),
+		       (void *)(cmp < 0 ? this_frame : other_frame));
+	} break;
+
+	case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN:
+		pr_err("BUG: KCSAN: %s in %pS\n", get_bug_type(ai->access_type),
+		       (void *)this_frame);
+		break;
+
+	default:
+		BUG();
+	}
+
+	pr_err("\n");
+
+	/* Print information about the racing accesses. */
+	switch (type) {
+	case KCSAN_REPORT_RACE_SIGNAL:
+		pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n",
+		       get_access_type(other_info->ai.access_type), other_info->ai.ptr,
+		       other_info->ai.size, get_thread_desc(other_info->ai.task_pid),
+		       other_info->ai.cpu_id);
+
+		/* Print the other thread's stack trace. */
+		stack_trace_print(other_info->stack_entries + other_skipnr,
+				  other_info->num_stack_entries - other_skipnr,
+				  0);
+
+		if (IS_ENABLED(CONFIG_KCSAN_VERBOSE))
+			print_verbose_info(other_info->task);
+
+		pr_err("\n");
+		pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n",
+		       get_access_type(ai->access_type), ai->ptr, ai->size,
+		       get_thread_desc(ai->task_pid), ai->cpu_id);
+		break;
+
+	case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN:
+		pr_err("race at unknown origin, with %s to 0x%px of %zu bytes by %s on cpu %i:\n",
+		       get_access_type(ai->access_type), ai->ptr, ai->size,
+		       get_thread_desc(ai->task_pid), ai->cpu_id);
+		break;
+
+	default:
+		BUG();
+	}
+	/* Print stack trace of this thread. */
+	stack_trace_print(stack_entries + skipnr, num_stack_entries - skipnr,
+			  0);
+
+	if (IS_ENABLED(CONFIG_KCSAN_VERBOSE))
+		print_verbose_info(current);
+
+	/* Print report footer. */
+	pr_err("\n");
+	pr_err("Reported by Kernel Concurrency Sanitizer on:\n");
+	dump_stack_print_info(KERN_DEFAULT);
+	pr_err("==================================================================\n");
+
+	return true;
+}
+
+static void release_report(unsigned long *flags, struct other_info *other_info)
+{
+	if (other_info)
+		/*
+		 * Use size to denote valid/invalid, since KCSAN entirely
+		 * ignores 0-sized accesses.
+		 */
+		other_info->ai.size = 0;
+
+	raw_spin_unlock_irqrestore(&report_lock, *flags);
+}
+
+/*
+ * Sets @other_info->task and awaits consumption of @other_info.
+ *
+ * Precondition: report_lock is held.
+ * Postcondition: report_lock is held.
+ */
+static void set_other_info_task_blocking(unsigned long *flags,
+					 const struct access_info *ai,
+					 struct other_info *other_info)
+{
+	/*
+	 * We may be instrumenting a code-path where current->state is already
+	 * something other than TASK_RUNNING.
+	 */
+	const bool is_running = current->state == TASK_RUNNING;
+	/*
+	 * To avoid deadlock in case we are in an interrupt here and this is a
+	 * race with a task on the same CPU (KCSAN_INTERRUPT_WATCHER), provide a
+	 * timeout to ensure this works in all contexts.
+	 *
+	 * Await approximately the worst case delay of the reporting thread (if
+	 * we are not interrupted).
+	 */
+	int timeout = max(kcsan_udelay_task, kcsan_udelay_interrupt);
+
+	other_info->task = current;
+	do {
+		if (is_running) {
+			/*
+			 * Let lockdep know the real task is sleeping, to print
+			 * the held locks (recall we turned lockdep off, so
+			 * locking/unlocking @report_lock won't be recorded).
+			 */
+			set_current_state(TASK_UNINTERRUPTIBLE);
+		}
+		raw_spin_unlock_irqrestore(&report_lock, *flags);
+		/*
+		 * We cannot call schedule() since we also cannot reliably
+		 * determine if sleeping here is permitted -- see in_atomic().
+		 */
+
+		udelay(1);
+		raw_spin_lock_irqsave(&report_lock, *flags);
+		if (timeout-- < 0) {
+			/*
+			 * Abort. Reset @other_info->task to NULL, since it
+			 * appears the other thread is still going to consume
+			 * it. It will result in no verbose info printed for
+			 * this task.
+			 */
+			other_info->task = NULL;
+			break;
+		}
+		/*
+		 * If invalid, or @ptr nor @current matches, then @other_info
+		 * has been consumed and we may continue. If not, retry.
+		 */
+	} while (other_info->ai.size && other_info->ai.ptr == ai->ptr &&
+		 other_info->task == current);
+	if (is_running)
+		set_current_state(TASK_RUNNING);
+}
+
+/* Populate @other_info; requires that the provided @other_info not in use. */
+static void prepare_report_producer(unsigned long *flags,
+				    const struct access_info *ai,
+				    struct other_info *other_info)
+{
+	raw_spin_lock_irqsave(&report_lock, *flags);
+
+	/*
+	 * The same @other_infos entry cannot be used concurrently, because
+	 * there is a one-to-one mapping to watchpoint slots (@watchpoints in
+	 * core.c), and a watchpoint is only released for reuse after reporting
+	 * is done by the consumer of @other_info. Therefore, it is impossible
+	 * for another concurrent prepare_report_producer() to set the same
+	 * @other_info, and are guaranteed exclusivity for the @other_infos
+	 * entry pointed to by @other_info.
+	 *
+	 * To check this property holds, size should never be non-zero here,
+	 * because every consumer of struct other_info resets size to 0 in
+	 * release_report().
+	 */
+	WARN_ON(other_info->ai.size);
+
+	other_info->ai = *ai;
+	other_info->num_stack_entries = stack_trace_save(other_info->stack_entries, NUM_STACK_ENTRIES, 2);
+
+	if (IS_ENABLED(CONFIG_KCSAN_VERBOSE))
+		set_other_info_task_blocking(flags, ai, other_info);
+
+	raw_spin_unlock_irqrestore(&report_lock, *flags);
+}
+
+/* Awaits producer to fill @other_info and then returns. */
+static bool prepare_report_consumer(unsigned long *flags,
+				    const struct access_info *ai,
+				    struct other_info *other_info)
+{
+
+	raw_spin_lock_irqsave(&report_lock, *flags);
+	while (!other_info->ai.size) { /* Await valid @other_info. */
+		raw_spin_unlock_irqrestore(&report_lock, *flags);
+		cpu_relax();
+		raw_spin_lock_irqsave(&report_lock, *flags);
+	}
+
+	/* Should always have a matching access based on watchpoint encoding. */
+	if (WARN_ON(!matching_access((unsigned long)other_info->ai.ptr & WATCHPOINT_ADDR_MASK, other_info->ai.size,
+				     (unsigned long)ai->ptr & WATCHPOINT_ADDR_MASK, ai->size)))
+		goto discard;
+
+	if (!matching_access((unsigned long)other_info->ai.ptr, other_info->ai.size,
+			     (unsigned long)ai->ptr, ai->size)) {
+		/*
+		 * If the actual accesses to not match, this was a false
+		 * positive due to watchpoint encoding.
+		 */
+		atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_ENCODING_FALSE_POSITIVES]);
+		goto discard;
+	}
+
+	return true;
+
+discard:
+	release_report(flags, other_info);
+	return false;
+}
+
+/*
+ * Depending on the report type either sets @other_info and returns false, or
+ * awaits @other_info and returns true. If @other_info is not required for the
+ * report type, simply acquires @report_lock and returns true.
+ */
+static noinline bool prepare_report(unsigned long *flags,
+				    enum kcsan_report_type type,
+				    const struct access_info *ai,
+				    struct other_info *other_info)
+{
+	switch (type) {
+	case KCSAN_REPORT_CONSUMED_WATCHPOINT:
+		prepare_report_producer(flags, ai, other_info);
+		return false;
+	case KCSAN_REPORT_RACE_SIGNAL:
+		return prepare_report_consumer(flags, ai, other_info);
+	default:
+		/* @other_info not required; just acquire @report_lock. */
+		raw_spin_lock_irqsave(&report_lock, *flags);
+		return true;
+	}
+}
+
+void kcsan_report(const volatile void *ptr, size_t size, int access_type,
+		  enum kcsan_value_change value_change,
+		  enum kcsan_report_type type, int watchpoint_idx)
+{
+	unsigned long flags = 0;
+	const struct access_info ai = {
+		.ptr		= ptr,
+		.size		= size,
+		.access_type	= access_type,
+		.task_pid	= in_task() ? task_pid_nr(current) : -1,
+		.cpu_id		= raw_smp_processor_id()
+	};
+	struct other_info *other_info = type == KCSAN_REPORT_RACE_UNKNOWN_ORIGIN
+					? NULL : &other_infos[watchpoint_idx];
+
+	kcsan_disable_current();
+	if (WARN_ON(watchpoint_idx < 0 || watchpoint_idx >= ARRAY_SIZE(other_infos)))
+		goto out;
+
+	/*
+	 * Because we may generate reports when we're in scheduler code, the use
+	 * of printk() could deadlock. Until such time that all printing code
+	 * called in print_report() is scheduler-safe, accept the risk, and just
+	 * get our message out. As such, also disable lockdep to hide the
+	 * warning, and avoid disabling lockdep for the rest of the kernel.
+	 */
+	lockdep_off();
+
+	if (prepare_report(&flags, type, &ai, other_info)) {
+		/*
+		 * Never report if value_change is FALSE, only if we it is
+		 * either TRUE or MAYBE. In case of MAYBE, further filtering may
+		 * be done once we know the full stack trace in print_report().
+		 */
+		bool reported = value_change != KCSAN_VALUE_CHANGE_FALSE &&
+				print_report(value_change, type, &ai, other_info);
+
+		if (reported && panic_on_warn)
+			panic("panic_on_warn set ...\n");
+
+		release_report(&flags, other_info);
+	}
+
+	lockdep_on();
+out:
+	kcsan_enable_current();
+}
diff --git a/kernel/kcsan/selftest.c b/kernel/kcsan/selftest.c
new file mode 100644
index 0000000..d98bc20
--- /dev/null
+++ b/kernel/kcsan/selftest.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "kcsan: " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/types.h>
+
+#include "encoding.h"
+
+#define ITERS_PER_TEST 2000
+
+/* Test requirements. */
+static bool test_requires(void)
+{
+	/* random should be initialized for the below tests */
+	return prandom_u32() + prandom_u32() != 0;
+}
+
+/*
+ * Test watchpoint encode and decode: check that encoding some access's info,
+ * and then subsequent decode preserves the access's info.
+ */
+static bool test_encode_decode(void)
+{
+	int i;
+
+	for (i = 0; i < ITERS_PER_TEST; ++i) {
+		size_t size = prandom_u32_max(MAX_ENCODABLE_SIZE) + 1;
+		bool is_write = !!prandom_u32_max(2);
+		unsigned long addr;
+
+		prandom_bytes(&addr, sizeof(addr));
+		if (WARN_ON(!check_encodable(addr, size)))
+			return false;
+
+		/* Encode and decode */
+		{
+			const long encoded_watchpoint =
+				encode_watchpoint(addr, size, is_write);
+			unsigned long verif_masked_addr;
+			size_t verif_size;
+			bool verif_is_write;
+
+			/* Check special watchpoints */
+			if (WARN_ON(decode_watchpoint(
+				    INVALID_WATCHPOINT, &verif_masked_addr,
+				    &verif_size, &verif_is_write)))
+				return false;
+			if (WARN_ON(decode_watchpoint(
+				    CONSUMED_WATCHPOINT, &verif_masked_addr,
+				    &verif_size, &verif_is_write)))
+				return false;
+
+			/* Check decoding watchpoint returns same data */
+			if (WARN_ON(!decode_watchpoint(
+				    encoded_watchpoint, &verif_masked_addr,
+				    &verif_size, &verif_is_write)))
+				return false;
+			if (WARN_ON(verif_masked_addr !=
+				    (addr & WATCHPOINT_ADDR_MASK)))
+				goto fail;
+			if (WARN_ON(verif_size != size))
+				goto fail;
+			if (WARN_ON(is_write != verif_is_write))
+				goto fail;
+
+			continue;
+fail:
+			pr_err("%s fail: %s %zu bytes @ %lx -> encoded: %lx -> %s %zu bytes @ %lx\n",
+			       __func__, is_write ? "write" : "read", size,
+			       addr, encoded_watchpoint,
+			       verif_is_write ? "write" : "read", verif_size,
+			       verif_masked_addr);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/* Test access matching function. */
+static bool test_matching_access(void)
+{
+	if (WARN_ON(!matching_access(10, 1, 10, 1)))
+		return false;
+	if (WARN_ON(!matching_access(10, 2, 11, 1)))
+		return false;
+	if (WARN_ON(!matching_access(10, 1, 9, 2)))
+		return false;
+	if (WARN_ON(matching_access(10, 1, 11, 1)))
+		return false;
+	if (WARN_ON(matching_access(9, 1, 10, 1)))
+		return false;
+
+	/*
+	 * An access of size 0 could match another access, as demonstrated here.
+	 * Rather than add more comparisons to 'matching_access()', which would
+	 * end up in the fast-path for *all* checks, check_access() simply
+	 * returns for all accesses of size 0.
+	 */
+	if (WARN_ON(!matching_access(8, 8, 12, 0)))
+		return false;
+
+	return true;
+}
+
+static int __init kcsan_selftest(void)
+{
+	int passed = 0;
+	int total = 0;
+
+#define RUN_TEST(do_test)                                                      \
+	do {                                                                   \
+		++total;                                                       \
+		if (do_test())                                                 \
+			++passed;                                              \
+		else                                                           \
+			pr_err("selftest: " #do_test " failed");               \
+	} while (0)
+
+	RUN_TEST(test_requires);
+	RUN_TEST(test_encode_decode);
+	RUN_TEST(test_matching_access);
+
+	pr_info("selftest: %d/%d tests passed\n", passed, total);
+	if (passed != total)
+		panic("selftests failed");
+	return 0;
+}
+postcore_initcall(kcsan_selftest);
diff --git a/kernel/kexec.c b/kernel/kexec.c
index bc933c0..c82c6c0 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -159,6 +159,10 @@
 
 	kimage_terminate(image);
 
+	ret = machine_kexec_post_load(image);
+	if (ret)
+		goto out;
+
 	/* Install the new kernel and uninstall the old */
 	image = xchg(dest_image, image);
 
@@ -201,7 +205,7 @@
 		return -EPERM;
 
 	/* Permit LSMs and IMA to fail the kexec */
-	result = security_kernel_load_data(LOADING_KEXEC_IMAGE);
+	result = security_kernel_load_data(LOADING_KEXEC_IMAGE, false);
 	if (result < 0)
 		return result;
 
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index d65b0fc..c589c7a 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -36,7 +36,7 @@
 #include <linux/syscore_ops.h>
 #include <linux/compiler.h>
 #include <linux/hugetlb.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -109,7 +109,7 @@
  * defined more restrictively in <asm/kexec.h>.
  *
  * The code for the transition from the current kernel to the
- * the new kernel is placed in the control_code_buffer, whose size
+ * new kernel is placed in the control_code_buffer, whose size
  * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
  * page of memory is necessary, but some architectures require more.
  * Because this memory must be identity mapped in the transition from
@@ -589,6 +589,12 @@
 	kimage_free_page_list(&image->unusable_pages);
 
 }
+
+int __weak machine_kexec_post_load(struct kimage *image)
+{
+	return 0;
+}
+
 void kimage_terminate(struct kimage *image)
 {
 	if (*image->entry != 0)
@@ -1170,7 +1176,7 @@
 		 * CPU hotplug again; so re-enable it here.
 		 */
 		cpu_hotplug_enable();
-		pr_emerg("Starting new kernel\n");
+		pr_notice("Starting new kernel\n");
 		machine_shutdown();
 	}
 
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b17998f..aea9104 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -24,6 +24,7 @@
 #include <linux/elf.h>
 #include <linux/elfcore.h>
 #include <linux/kernel.h>
+#include <linux/kernel_read_file.h>
 #include <linux/syscalls.h>
 #include <linux/vmalloc.h>
 #include "kexec_internal.h"
@@ -186,34 +187,19 @@
 static int
 kimage_validate_signature(struct kimage *image)
 {
-	const char *reason;
 	int ret;
 
 	ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
 					   image->kernel_buf_len);
-	switch (ret) {
-	case 0:
-		break;
+	if (ret) {
 
-		/* Certain verification errors are non-fatal if we're not
-		 * checking errors, provided we aren't mandating that there
-		 * must be a valid signature.
-		 */
-	case -ENODATA:
-		reason = "kexec of unsigned image";
-		goto decide;
-	case -ENOPKG:
-		reason = "kexec of image with unsupported crypto";
-		goto decide;
-	case -ENOKEY:
-		reason = "kexec of image with unavailable key";
-	decide:
 		if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
-			pr_notice("%s rejected\n", reason);
+			pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
 			return ret;
 		}
 
-		/* If IMA is guaranteed to appraise a signature on the kexec
+		/*
+		 * If IMA is guaranteed to appraise a signature on the kexec
 		 * image, permit it even if the kernel is otherwise locked
 		 * down.
 		 */
@@ -221,17 +207,10 @@
 		    security_locked_down(LOCKDOWN_KEXEC))
 			return -EPERM;
 
-		return 0;
-
-		/* All other errors are fatal, including nomem, unparseable
-		 * signatures and signature check failures - even if signatures
-		 * aren't required.
-		 */
-	default:
-		pr_notice("kernel signature verification failed (%d).\n", ret);
+		pr_debug("kernel signature verification failed (%d).\n", ret);
 	}
 
-	return ret;
+	return 0;
 }
 #endif
 
@@ -246,13 +225,12 @@
 {
 	int ret;
 	void *ldata;
-	loff_t size;
 
-	ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
-				       &size, INT_MAX, READING_KEXEC_IMAGE);
-	if (ret)
+	ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
+				       INT_MAX, NULL, READING_KEXEC_IMAGE);
+	if (ret < 0)
 		return ret;
-	image->kernel_buf_len = size;
+	image->kernel_buf_len = ret;
 
 	/* Call arch image probe handlers */
 	ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
@@ -268,12 +246,13 @@
 #endif
 	/* It is possible that there no initramfs is being loaded */
 	if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
-		ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
-					       &size, INT_MAX,
+		ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
+					       INT_MAX, NULL,
 					       READING_KEXEC_INITRAMFS);
-		if (ret)
+		if (ret < 0)
 			goto out;
-		image->initrd_buf_len = size;
+		image->initrd_buf_len = ret;
+		ret = 0;
 	}
 
 	if (cmdline_len) {
@@ -292,7 +271,7 @@
 			goto out;
 		}
 
-		ima_kexec_cmdline(image->cmdline_buf,
+		ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
 				  image->cmdline_buf_len - 1);
 	}
 
@@ -446,6 +425,10 @@
 
 	kimage_terminate(image);
 
+	ret = machine_kexec_post_load(image);
+	if (ret)
+		goto out;
+
 	/*
 	 * Free up any temporary buffers allocated which are not needed
 	 * after image has been loaded
@@ -541,6 +524,11 @@
 	unsigned long sz = end - start + 1;
 
 	/* Returning 0 will take to next memory range */
+
+	/* Don't use memory that will be detected and handled by a driver. */
+	if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
+		return 0;
+
 	if (sz < kbuf->memsz)
 		return 0;
 
@@ -654,6 +642,19 @@
 }
 
 /**
+ * arch_kexec_locate_mem_hole - Find free memory to place the segments.
+ * @kbuf:                       Parameters for the memory search.
+ *
+ * On success, kbuf->mem will have the start address of the memory region found.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
+{
+	return kexec_locate_mem_hole(kbuf);
+}
+
+/**
  * kexec_add_buffer - place a buffer in a kexec segment
  * @kbuf:	Buffer contents and memory parameters.
  *
@@ -665,7 +666,6 @@
  */
 int kexec_add_buffer(struct kexec_buf *kbuf)
 {
-
 	struct kexec_segment *ksegment;
 	int ret;
 
@@ -693,7 +693,7 @@
 	kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
-	ret = kexec_locate_mem_hole(kbuf);
+	ret = arch_kexec_locate_mem_hole(kbuf);
 	if (ret)
 		return ret;
 
@@ -1177,24 +1177,26 @@
 			    unsigned long long mstart, unsigned long long mend)
 {
 	int i, j;
-	unsigned long long start, end;
+	unsigned long long start, end, p_start, p_end;
 	struct crash_mem_range temp_range = {0, 0};
 
 	for (i = 0; i < mem->nr_ranges; i++) {
 		start = mem->ranges[i].start;
 		end = mem->ranges[i].end;
+		p_start = mstart;
+		p_end = mend;
 
 		if (mstart > end || mend < start)
 			continue;
 
 		/* Truncate any area outside of range */
 		if (mstart < start)
-			mstart = start;
+			p_start = start;
 		if (mend > end)
-			mend = end;
+			p_end = end;
 
 		/* Found completely overlapping range */
-		if (mstart == start && mend == end) {
+		if (p_start == start && p_end == end) {
 			mem->ranges[i].start = 0;
 			mem->ranges[i].end = 0;
 			if (i < mem->nr_ranges - 1) {
@@ -1205,20 +1207,29 @@
 					mem->ranges[j].end =
 							mem->ranges[j+1].end;
 				}
+
+				/*
+				 * Continue to check if there are another overlapping ranges
+				 * from the current position because of shifting the above
+				 * mem ranges.
+				 */
+				i--;
+				mem->nr_ranges--;
+				continue;
 			}
 			mem->nr_ranges--;
 			return 0;
 		}
 
-		if (mstart > start && mend < end) {
+		if (p_start > start && p_end < end) {
 			/* Split original range */
-			mem->ranges[i].end = mstart - 1;
-			temp_range.start = mend + 1;
+			mem->ranges[i].end = p_start - 1;
+			temp_range.start = p_end + 1;
 			temp_range.end = end;
-		} else if (mstart != start)
-			mem->ranges[i].end = mstart - 1;
+		} else if (p_start != start)
+			mem->ranges[i].end = p_start - 1;
 		else
-			mem->ranges[i].start = mend + 1;
+			mem->ranges[i].start = p_end + 1;
 		break;
 	}
 
@@ -1255,7 +1266,7 @@
 	unsigned long long notes_addr;
 	unsigned long mstart, mend;
 
-	/* extra phdr for vmcoreinfo elf note */
+	/* extra phdr for vmcoreinfo ELF note */
 	nr_phdr = nr_cpus + 1;
 	nr_phdr += mem->nr_ranges;
 
@@ -1263,7 +1274,7 @@
 	 * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
 	 * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
 	 * I think this is required by tools like gdb. So same physical
-	 * memory will be mapped in two elf headers. One will contain kernel
+	 * memory will be mapped in two ELF headers. One will contain kernel
 	 * text virtual addresses and other will have __va(physical) addresses.
 	 */
 
@@ -1290,7 +1301,7 @@
 	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
 	ehdr->e_phentsize = sizeof(Elf64_Phdr);
 
-	/* Prepare one phdr of type PT_NOTE for each present cpu */
+	/* Prepare one phdr of type PT_NOTE for each present CPU */
 	for_each_present_cpu(cpu) {
 		phdr->p_type = PT_NOTE;
 		notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
@@ -1311,7 +1322,7 @@
 	if (kernel_map) {
 		phdr->p_type = PT_LOAD;
 		phdr->p_flags = PF_R|PF_W|PF_X;
-		phdr->p_vaddr = (Elf64_Addr)_text;
+		phdr->p_vaddr = (unsigned long) _text;
 		phdr->p_filesz = phdr->p_memsz = _end - _text;
 		phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
 		ehdr->e_phnum++;
@@ -1328,14 +1339,14 @@
 		phdr->p_offset  = mstart;
 
 		phdr->p_paddr = mstart;
-		phdr->p_vaddr = (unsigned long long) __va(mstart);
+		phdr->p_vaddr = (unsigned long) __va(mstart);
 		phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
 		phdr->p_align = 0;
 		ehdr->e_phnum++;
-		phdr++;
-		pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
+		pr_debug("Crash PT_LOAD ELF header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
 			phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
 			ehdr->e_phnum, phdr->p_offset);
+		phdr++;
 	}
 
 	*addr = buf;
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index 48aaf2a..39d30cc 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -13,6 +13,8 @@
 int kimage_is_destination_range(struct kimage *image,
 				unsigned long start, unsigned long end);
 
+int machine_kexec_post_load(struct kimage *image);
+
 extern struct mutex kexec_mutex;
 
 #ifdef CONFIG_KEXEC_FILE
diff --git a/kernel/kmod.c b/kernel/kmod.c
index a2de58d..3cd075c 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -35,10 +35,9 @@
  *		       (u64) THREAD_SIZE * 8UL);
  *
  * If you need less than 50 threads would mean we're dealing with systems
- * smaller than 3200 pages. This assuems you are capable of having ~13M memory,
- * and this would only be an be an upper limit, after which the OOM killer
- * would take effect. Systems like these are very unlikely if modules are
- * enabled.
+ * smaller than 3200 pages. This assumes you are capable of having ~13M memory,
+ * and this would only be an upper limit, after which the OOM killer would take
+ * effect. Systems like these are very unlikely if modules are enabled.
  */
 #define MAX_KMOD_CONCURRENT 50
 static atomic_t kmod_concurrent_max = ATOMIC_INIT(MAX_KMOD_CONCURRENT);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a7812c1..cdea59a 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -35,6 +35,8 @@
 #include <linux/ftrace.h>
 #include <linux/cpu.h>
 #include <linux/jump_label.h>
+#include <linux/perf_event.h>
+#include <linux/static_call.h>
 
 #include <asm/sections.h>
 #include <asm/cacheflush.h>
@@ -46,6 +48,11 @@
 
 
 static int kprobes_initialized;
+/* kprobe_table can be accessed by
+ * - Normal hlist traversal and RCU add/del under kprobe_mutex is held.
+ * Or
+ * - RCU hlist traversal under disabling preempt (breakpoint handlers)
+ */
 static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
 static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
 
@@ -118,6 +125,7 @@
 	.mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex),
 	.alloc = alloc_insn_page,
 	.free = free_insn_page,
+	.sym = KPROBE_INSN_PAGE_SYM,
 	.pages = LIST_HEAD_INIT(kprobe_insn_slots.pages),
 	.insn_size = MAX_INSN_SIZE,
 	.nr_garbage = 0,
@@ -183,6 +191,10 @@
 	kip->cache = c;
 	list_add_rcu(&kip->list, &c->pages);
 	slot = kip->insns;
+
+	/* Record the perf ksymbol register event after adding the page */
+	perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, (unsigned long)kip->insns,
+			   PAGE_SIZE, false, c->sym);
 out:
 	mutex_unlock(&c->mutex);
 	return slot;
@@ -201,6 +213,13 @@
 		 * next time somebody inserts a probe.
 		 */
 		if (!list_is_singular(&kip->list)) {
+			/*
+			 * Record perf ksymbol unregister event before removing
+			 * the page.
+			 */
+			perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+					   (unsigned long)kip->insns, PAGE_SIZE, true,
+					   kip->cache->sym);
 			list_del_rcu(&kip->list);
 			synchronize_rcu();
 			kip->cache->free(kip->insns);
@@ -290,12 +309,34 @@
 	return ret;
 }
 
+int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum,
+			     unsigned long *value, char *type, char *sym)
+{
+	struct kprobe_insn_page *kip;
+	int ret = -ERANGE;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(kip, &c->pages, list) {
+		if ((*symnum)--)
+			continue;
+		strlcpy(sym, c->sym, KSYM_NAME_LEN);
+		*type = 't';
+		*value = (unsigned long)kip->insns;
+		ret = 0;
+		break;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
 #ifdef CONFIG_OPTPROBES
 /* For optimized_kprobe buffer */
 struct kprobe_insn_cache kprobe_optinsn_slots = {
 	.mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex),
 	.alloc = alloc_insn_page,
 	.free = free_insn_page,
+	.sym = KPROBE_OPTINSN_PAGE_SYM,
 	.pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages),
 	/* .insn_size is initialized later */
 	.nr_garbage = 0,
@@ -558,8 +599,6 @@
 	mutex_lock(&kprobe_mutex);
 	cpus_read_lock();
 	mutex_lock(&text_mutex);
-	/* Lock modules while optimizing kprobes */
-	mutex_lock(&module_mutex);
 
 	/*
 	 * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed)
@@ -584,7 +623,6 @@
 	/* Step 4: Free cleaned kprobes after quiesence period */
 	do_free_cleaned_kprobes();
 
-	mutex_unlock(&module_mutex);
 	mutex_unlock(&text_mutex);
 	cpus_read_unlock();
 
@@ -670,8 +708,6 @@
 	lockdep_assert_cpus_held();
 	arch_unoptimize_kprobe(op);
 	op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
-	if (kprobe_disabled(&op->kp))
-		arch_disarm_kprobe(&op->kp);
 }
 
 /* Unoptimize a kprobe if p is optimized */
@@ -835,7 +871,6 @@
 	cpus_read_unlock();
 }
 
-#ifdef CONFIG_SYSCTL
 static void optimize_all_kprobes(void)
 {
 	struct hlist_head *head;
@@ -851,7 +886,7 @@
 	kprobes_allow_optimization = true;
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, head, hlist)
+		hlist_for_each_entry(p, head, hlist)
 			if (!kprobe_disabled(p))
 				optimize_kprobe(p);
 	}
@@ -861,6 +896,7 @@
 	mutex_unlock(&kprobe_mutex);
 }
 
+#ifdef CONFIG_SYSCTL
 static void unoptimize_all_kprobes(void)
 {
 	struct hlist_head *head;
@@ -878,7 +914,7 @@
 	kprobes_allow_optimization = false;
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, head, hlist) {
+		hlist_for_each_entry(p, head, hlist) {
 			if (!kprobe_disabled(p))
 				unoptimize_kprobe(p, false);
 		}
@@ -894,7 +930,7 @@
 static DEFINE_MUTEX(kprobe_sysctl_mutex);
 int sysctl_kprobes_optimization;
 int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
-				      void __user *buffer, size_t *length,
+				      void *buffer, size_t *length,
 				      loff_t *ppos)
 {
 	int ret;
@@ -1188,8 +1224,7 @@
 }
 NOKPROBE_SYMBOL(kprobes_inc_nmissed_count);
 
-void recycle_rp_inst(struct kretprobe_instance *ri,
-		     struct hlist_head *head)
+static void recycle_rp_inst(struct kretprobe_instance *ri)
 {
 	struct kretprobe *rp = ri->rp;
 
@@ -1201,12 +1236,11 @@
 		hlist_add_head(&ri->hlist, &rp->free_instances);
 		raw_spin_unlock(&rp->lock);
 	} else
-		/* Unregistering */
-		hlist_add_head(&ri->hlist, head);
+		kfree_rcu(ri, rcu);
 }
 NOKPROBE_SYMBOL(recycle_rp_inst);
 
-void kretprobe_hash_lock(struct task_struct *tsk,
+static void kretprobe_hash_lock(struct task_struct *tsk,
 			 struct hlist_head **head, unsigned long *flags)
 __acquires(hlist_lock)
 {
@@ -1215,7 +1249,13 @@
 
 	*head = &kretprobe_inst_table[hash];
 	hlist_lock = kretprobe_table_lock_ptr(hash);
-	raw_spin_lock_irqsave(hlist_lock, *flags);
+	/*
+	 * Nested is a workaround that will soon not be needed.
+	 * There's other protections that make sure the same lock
+	 * is not taken on the same CPU that lockdep is unaware of.
+	 * Differentiate when it is taken in NMI context.
+	 */
+	raw_spin_lock_irqsave_nested(hlist_lock, *flags, !!in_nmi());
 }
 NOKPROBE_SYMBOL(kretprobe_hash_lock);
 
@@ -1224,11 +1264,17 @@
 __acquires(hlist_lock)
 {
 	raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
-	raw_spin_lock_irqsave(hlist_lock, *flags);
+	/*
+	 * Nested is a workaround that will soon not be needed.
+	 * There's other protections that make sure the same lock
+	 * is not taken on the same CPU that lockdep is unaware of.
+	 * Differentiate when it is taken in NMI context.
+	 */
+	raw_spin_lock_irqsave_nested(hlist_lock, *flags, !!in_nmi());
 }
 NOKPROBE_SYMBOL(kretprobe_table_lock);
 
-void kretprobe_hash_unlock(struct task_struct *tsk,
+static void kretprobe_hash_unlock(struct task_struct *tsk,
 			   unsigned long *flags)
 __releases(hlist_lock)
 {
@@ -1249,7 +1295,7 @@
 }
 NOKPROBE_SYMBOL(kretprobe_table_unlock);
 
-struct kprobe kprobe_busy = {
+static struct kprobe kprobe_busy = {
 	.addr = (void *) get_kprobe,
 };
 
@@ -1278,7 +1324,7 @@
 void kprobe_flush_task(struct task_struct *tk)
 {
 	struct kretprobe_instance *ri;
-	struct hlist_head *head, empty_rp;
+	struct hlist_head *head;
 	struct hlist_node *tmp;
 	unsigned long hash, flags = 0;
 
@@ -1288,19 +1334,14 @@
 
 	kprobe_busy_begin();
 
-	INIT_HLIST_HEAD(&empty_rp);
 	hash = hash_ptr(tk, KPROBE_HASH_BITS);
 	head = &kretprobe_inst_table[hash];
 	kretprobe_table_lock(hash, &flags);
 	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
 		if (ri->task == tk)
-			recycle_rp_inst(ri, &empty_rp);
+			recycle_rp_inst(ri);
 	}
 	kretprobe_table_unlock(hash, &flags);
-	hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
-		hlist_del(&ri->hlist);
-		kfree(ri);
-	}
 
 	kprobe_busy_end();
 }
@@ -1324,7 +1365,8 @@
 	struct hlist_node *next;
 	struct hlist_head *head;
 
-	/* No race here */
+	/* To avoid recursive kretprobe by NMI, set kprobe busy here */
+	kprobe_busy_begin();
 	for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
 		kretprobe_table_lock(hash, &flags);
 		head = &kretprobe_inst_table[hash];
@@ -1334,6 +1376,8 @@
 		}
 		kretprobe_table_unlock(hash, &flags);
 	}
+	kprobe_busy_end();
+
 	free_rp_inst(rp);
 }
 NOKPROBE_SYMBOL(cleanup_rp_inst);
@@ -1536,12 +1580,14 @@
 {
 	struct kprobe *ap, *list_p;
 
+	lockdep_assert_held(&kprobe_mutex);
+
 	ap = get_kprobe(p->addr);
 	if (unlikely(!ap))
 		return NULL;
 
 	if (p != ap) {
-		list_for_each_entry_rcu(list_p, &ap->list, list)
+		list_for_each_entry(list_p, &ap->list, list)
 			if (list_p == p)
 			/* kprobe p is a valid probe */
 				goto valid;
@@ -1597,6 +1643,7 @@
 	if (!kernel_text_address((unsigned long) p->addr) ||
 	    within_kprobe_blacklist((unsigned long) p->addr) ||
 	    jump_label_text_reserved(p->addr, p->addr) ||
+	    static_call_text_reserved(p->addr, p->addr) ||
 	    find_bug((unsigned long)p->addr)) {
 		ret = -EINVAL;
 		goto out;
@@ -1706,7 +1753,9 @@
 {
 	struct kprobe *kp;
 
-	list_for_each_entry_rcu(kp, &ap->list, list)
+	lockdep_assert_held(&kprobe_mutex);
+
+	list_for_each_entry(kp, &ap->list, list)
 		if (!kprobe_disabled(kp))
 			/*
 			 * There is an active probe on the list.
@@ -1785,7 +1834,7 @@
 	else {
 		/* If disabling probe has special handlers, update aggrprobe */
 		if (p->post_handler && !kprobe_gone(p)) {
-			list_for_each_entry_rcu(list_p, &ap->list, list) {
+			list_for_each_entry(list_p, &ap->list, list) {
 				if ((list_p != p) && (list_p->post_handler))
 					goto noclean;
 			}
@@ -1888,6 +1937,97 @@
 }
 
 #ifdef CONFIG_KRETPROBES
+
+unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
+					     void *trampoline_address,
+					     void *frame_pointer)
+{
+	struct kretprobe_instance *ri = NULL, *last = NULL;
+	struct hlist_head *head;
+	struct hlist_node *tmp;
+	unsigned long flags;
+	kprobe_opcode_t *correct_ret_addr = NULL;
+	bool skipped = false;
+
+	kretprobe_hash_lock(current, &head, &flags);
+
+	/*
+	 * It is possible to have multiple instances associated with a given
+	 * task either because multiple functions in the call path have
+	 * return probes installed on them, and/or more than one
+	 * return probe was registered for a target function.
+	 *
+	 * We can handle this because:
+	 *     - instances are always pushed into the head of the list
+	 *     - when multiple return probes are registered for the same
+	 *	 function, the (chronologically) first instance's ret_addr
+	 *	 will be the real return address, and all the rest will
+	 *	 point to kretprobe_trampoline.
+	 */
+	hlist_for_each_entry(ri, head, hlist) {
+		if (ri->task != current)
+			/* another task is sharing our hash bucket */
+			continue;
+		/*
+		 * Return probes must be pushed on this hash list correct
+		 * order (same as return order) so that it can be popped
+		 * correctly. However, if we find it is pushed it incorrect
+		 * order, this means we find a function which should not be
+		 * probed, because the wrong order entry is pushed on the
+		 * path of processing other kretprobe itself.
+		 */
+		if (ri->fp != frame_pointer) {
+			if (!skipped)
+				pr_warn("kretprobe is stacked incorrectly. Trying to fixup.\n");
+			skipped = true;
+			continue;
+		}
+
+		correct_ret_addr = ri->ret_addr;
+		if (skipped)
+			pr_warn("%ps must be blacklisted because of incorrect kretprobe order\n",
+				ri->rp->kp.addr);
+
+		if (correct_ret_addr != trampoline_address)
+			/*
+			 * This is the real return address. Any other
+			 * instances associated with this task are for
+			 * other calls deeper on the call stack
+			 */
+			break;
+	}
+
+	BUG_ON(!correct_ret_addr || (correct_ret_addr == trampoline_address));
+	last = ri;
+
+	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
+		if (ri->task != current)
+			/* another task is sharing our hash bucket */
+			continue;
+		if (ri->fp != frame_pointer)
+			continue;
+
+		if (ri->rp && ri->rp->handler) {
+			struct kprobe *prev = kprobe_running();
+
+			__this_cpu_write(current_kprobe, &ri->rp->kp);
+			ri->ret_addr = correct_ret_addr;
+			ri->rp->handler(ri, regs);
+			__this_cpu_write(current_kprobe, prev);
+		}
+
+		recycle_rp_inst(ri);
+
+		if (ri == last)
+			break;
+	}
+
+	kretprobe_hash_unlock(current, &flags);
+
+	return (unsigned long)correct_ret_addr;
+}
+NOKPROBE_SYMBOL(__kretprobe_trampoline_handler)
+
 /*
  * This kprobe pre_handler is registered with every kretprobe. When probe
  * hits it will set up the return probe.
@@ -1898,20 +2038,14 @@
 	unsigned long hash, flags = 0;
 	struct kretprobe_instance *ri;
 
-	/*
-	 * To avoid deadlocks, prohibit return probing in NMI contexts,
-	 * just skip the probe and increase the (inexact) 'nmissed'
-	 * statistical counter, so that the user is informed that
-	 * something happened:
-	 */
-	if (unlikely(in_nmi())) {
-		rp->nmissed++;
-		return 0;
-	}
-
 	/* TODO: consider to only swap the RA after the last pre_handler fired */
 	hash = hash_ptr(current, KPROBE_HASH_BITS);
-	raw_spin_lock_irqsave(&rp->lock, flags);
+	/*
+	 * Nested is a workaround that will soon not be needed.
+	 * There's other protections that make sure the same lock
+	 * is not taken on the same CPU that lockdep is unaware of.
+	 */
+	raw_spin_lock_irqsave_nested(&rp->lock, flags, 1);
 	if (!hlist_empty(&rp->free_instances)) {
 		ri = hlist_entry(rp->free_instances.first,
 				struct kretprobe_instance, hlist);
@@ -1922,7 +2056,7 @@
 		ri->task = current;
 
 		if (rp->entry_handler && rp->entry_handler(ri, regs)) {
-			raw_spin_lock_irqsave(&rp->lock, flags);
+			raw_spin_lock_irqsave_nested(&rp->lock, flags, 1);
 			hlist_add_head(&ri->hlist, &rp->free_instances);
 			raw_spin_unlock_irqrestore(&rp->lock, flags);
 			return 0;
@@ -2003,6 +2137,9 @@
 		}
 	}
 
+	if (rp->data_size > KRETPROBE_MAX_DATA_SIZE)
+		return -E2BIG;
+
 	rp->kp.pre_handler = pre_handler_kretprobe;
 	rp->kp.post_handler = NULL;
 	rp->kp.fault_handler = NULL;
@@ -2119,6 +2256,8 @@
 {
 	struct kprobe *kp;
 
+	lockdep_assert_held(&kprobe_mutex);
+
 	if (WARN_ON_ONCE(kprobe_gone(p)))
 		return;
 
@@ -2128,7 +2267,7 @@
 		 * If this is an aggr_kprobe, we have to list all the
 		 * chained probes and mark them GONE.
 		 */
-		list_for_each_entry_rcu(kp, &p->list, list)
+		list_for_each_entry(kp, &p->list, list)
 			kp->flags |= KPROBE_FLAG_GONE;
 		p->post_handler = NULL;
 		kill_optimized_kprobe(p);
@@ -2247,6 +2386,46 @@
 	return 0;
 }
 
+/* Remove all symbols in given area from kprobe blacklist */
+static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end)
+{
+	struct kprobe_blacklist_entry *ent, *n;
+
+	list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) {
+		if (ent->start_addr < start || ent->start_addr >= end)
+			continue;
+		list_del(&ent->list);
+		kfree(ent);
+	}
+}
+
+static void kprobe_remove_ksym_blacklist(unsigned long entry)
+{
+	kprobe_remove_area_blacklist(entry, entry + 1);
+}
+
+int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value,
+				   char *type, char *sym)
+{
+	return -ERANGE;
+}
+
+int kprobe_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
+		       char *sym)
+{
+#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
+	if (!kprobe_cache_get_kallsym(&kprobe_insn_slots, &symnum, value, type, sym))
+		return 0;
+#ifdef CONFIG_OPTPROBES
+	if (!kprobe_cache_get_kallsym(&kprobe_optinsn_slots, &symnum, value, type, sym))
+		return 0;
+#endif
+#endif
+	if (!arch_kprobe_get_kallsym(&symnum, value, type, sym))
+		return 0;
+	return -ERANGE;
+}
+
 int __init __weak arch_populate_kprobe_blacklist(void)
 {
 	return 0;
@@ -2279,10 +2458,62 @@
 	/* Symbols in __kprobes_text are blacklisted */
 	ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start,
 					(unsigned long)__kprobes_text_end);
+	if (ret)
+		return ret;
+
+	/* Symbols in noinstr section are blacklisted */
+	ret = kprobe_add_area_blacklist((unsigned long)__noinstr_text_start,
+					(unsigned long)__noinstr_text_end);
 
 	return ret ? : arch_populate_kprobe_blacklist();
 }
 
+static void add_module_kprobe_blacklist(struct module *mod)
+{
+	unsigned long start, end;
+	int i;
+
+	if (mod->kprobe_blacklist) {
+		for (i = 0; i < mod->num_kprobe_blacklist; i++)
+			kprobe_add_ksym_blacklist(mod->kprobe_blacklist[i]);
+	}
+
+	start = (unsigned long)mod->kprobes_text_start;
+	if (start) {
+		end = start + mod->kprobes_text_size;
+		kprobe_add_area_blacklist(start, end);
+	}
+
+	start = (unsigned long)mod->noinstr_text_start;
+	if (start) {
+		end = start + mod->noinstr_text_size;
+		kprobe_add_area_blacklist(start, end);
+	}
+}
+
+static void remove_module_kprobe_blacklist(struct module *mod)
+{
+	unsigned long start, end;
+	int i;
+
+	if (mod->kprobe_blacklist) {
+		for (i = 0; i < mod->num_kprobe_blacklist; i++)
+			kprobe_remove_ksym_blacklist(mod->kprobe_blacklist[i]);
+	}
+
+	start = (unsigned long)mod->kprobes_text_start;
+	if (start) {
+		end = start + mod->kprobes_text_size;
+		kprobe_remove_area_blacklist(start, end);
+	}
+
+	start = (unsigned long)mod->noinstr_text_start;
+	if (start) {
+		end = start + mod->noinstr_text_size;
+		kprobe_remove_area_blacklist(start, end);
+	}
+}
+
 /* Module notifier call back, checking kprobes on the module */
 static int kprobes_module_callback(struct notifier_block *nb,
 				   unsigned long val, void *data)
@@ -2293,6 +2524,11 @@
 	unsigned int i;
 	int checkcore = (val == MODULE_STATE_GOING);
 
+	if (val == MODULE_STATE_COMING) {
+		mutex_lock(&kprobe_mutex);
+		add_module_kprobe_blacklist(mod);
+		mutex_unlock(&kprobe_mutex);
+	}
 	if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE)
 		return NOTIFY_DONE;
 
@@ -2305,7 +2541,7 @@
 	mutex_lock(&kprobe_mutex);
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, head, hlist) {
+		hlist_for_each_entry(p, head, hlist) {
 			if (kprobe_gone(p))
 				continue;
 
@@ -2327,6 +2563,8 @@
 			}
 		}
 	}
+	if (val == MODULE_STATE_GOING)
+		remove_module_kprobe_blacklist(mod);
 	mutex_unlock(&kprobe_mutex);
 	return NOTIFY_DONE;
 }
@@ -2392,18 +2630,14 @@
 		}
 	}
 
-#if defined(CONFIG_OPTPROBES)
-#if defined(__ARCH_WANT_KPROBES_INSN_SLOT)
-	/* Init kprobe_optinsn_slots */
-	kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE;
-#endif
-	/* By default, kprobes can be optimized */
-	kprobes_allow_optimization = true;
-#endif
-
 	/* By default, kprobes are armed */
 	kprobes_all_disarmed = false;
 
+#if defined(CONFIG_OPTPROBES) && defined(__ARCH_WANT_KPROBES_INSN_SLOT)
+	/* Init kprobe_optinsn_slots for allocation */
+	kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE;
+#endif
+
 	err = arch_init_kprobes();
 	if (!err)
 		err = register_die_notifier(&kprobe_exceptions_nb);
@@ -2416,7 +2650,22 @@
 		init_test_probes();
 	return err;
 }
-subsys_initcall(init_kprobes);
+early_initcall(init_kprobes);
+
+#if defined(CONFIG_OPTPROBES)
+static int __init init_optprobes(void)
+{
+	/*
+	 * Enable kprobe optimization - this kicks the optimizer which
+	 * depends on synchronize_rcu_tasks() and ksoftirqd, that is
+	 * not spawned in early initcall. So delay the optimization.
+	 */
+	optimize_all_kprobes();
+
+	return 0;
+}
+subsys_initcall(init_optprobes);
+#endif
 
 #ifdef CONFIG_DEBUG_FS
 static void report_probe(struct seq_file *pi, struct kprobe *p,
@@ -2492,28 +2741,19 @@
 	return 0;
 }
 
-static const struct seq_operations kprobes_seq_ops = {
+static const struct seq_operations kprobes_sops = {
 	.start = kprobe_seq_start,
 	.next  = kprobe_seq_next,
 	.stop  = kprobe_seq_stop,
 	.show  = show_kprobe_addr
 };
 
-static int kprobes_open(struct inode *inode, struct file *filp)
-{
-	return seq_open(filp, &kprobes_seq_ops);
-}
-
-static const struct file_operations debugfs_kprobes_operations = {
-	.open           = kprobes_open,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.release        = seq_release,
-};
+DEFINE_SEQ_ATTRIBUTE(kprobes);
 
 /* kprobes/blacklist -- shows which functions can not be probed */
 static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos)
 {
+	mutex_lock(&kprobe_mutex);
 	return seq_list_start(&kprobe_blacklist, *pos);
 }
 
@@ -2540,24 +2780,18 @@
 	return 0;
 }
 
-static const struct seq_operations kprobe_blacklist_seq_ops = {
-	.start = kprobe_blacklist_seq_start,
-	.next  = kprobe_blacklist_seq_next,
-	.stop  = kprobe_seq_stop,	/* Reuse void function */
-	.show  = kprobe_blacklist_seq_show,
-};
-
-static int kprobe_blacklist_open(struct inode *inode, struct file *filp)
+static void kprobe_blacklist_seq_stop(struct seq_file *f, void *v)
 {
-	return seq_open(filp, &kprobe_blacklist_seq_ops);
+	mutex_unlock(&kprobe_mutex);
 }
 
-static const struct file_operations debugfs_kprobe_blacklist_ops = {
-	.open           = kprobe_blacklist_open,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.release        = seq_release,
+static const struct seq_operations kprobe_blacklist_sops = {
+	.start = kprobe_blacklist_seq_start,
+	.next  = kprobe_blacklist_seq_next,
+	.stop  = kprobe_blacklist_seq_stop,
+	.show  = kprobe_blacklist_seq_show,
 };
+DEFINE_SEQ_ATTRIBUTE(kprobe_blacklist);
 
 static int arm_all_kprobes(void)
 {
@@ -2582,7 +2816,7 @@
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
 		/* Arm all kprobes on a best-effort basis */
-		hlist_for_each_entry_rcu(p, head, hlist) {
+		hlist_for_each_entry(p, head, hlist) {
 			if (!kprobe_disabled(p)) {
 				err = arm_kprobe(p);
 				if (err)  {
@@ -2625,7 +2859,7 @@
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
 		/* Disarm all kprobes on a best-effort basis */
-		hlist_for_each_entry_rcu(p, head, hlist) {
+		hlist_for_each_entry(p, head, hlist) {
 			if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) {
 				err = disarm_kprobe(p, false);
 				if (err) {
@@ -2712,17 +2946,15 @@
 static int __init debugfs_kprobe_init(void)
 {
 	struct dentry *dir;
-	unsigned int value = 1;
 
 	dir = debugfs_create_dir("kprobes", NULL);
 
-	debugfs_create_file("list", 0400, dir, NULL,
-			    &debugfs_kprobes_operations);
+	debugfs_create_file("list", 0400, dir, NULL, &kprobes_fops);
 
-	debugfs_create_file("enabled", 0600, dir, &value, &fops_kp);
+	debugfs_create_file("enabled", 0600, dir, NULL, &fops_kp);
 
 	debugfs_create_file("blacklist", 0400, dir, NULL,
-			    &debugfs_kprobe_blacklist_ops);
+			    &kprobe_blacklist_fops);
 
 	return 0;
 }
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 63f7eb3..508fe52 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -1,13 +1,17 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /* Kernel thread helper functions.
  *   Copyright (C) 2004 IBM Corporation, Rusty Russell.
+ *   Copyright (C) 2009 Red Hat, Inc.
  *
  * Creation is done via kthreadd, so that we get a clean environment
  * even if we're invoked from userspace (think modprobe, hotplug cpu,
  * etc.).
  */
 #include <uapi/linux/sched/types.h>
+#include <linux/mm.h>
+#include <linux/mmu_context.h>
 #include <linux/sched.h>
+#include <linux/sched/mm.h>
 #include <linux/sched/task.h>
 #include <linux/kthread.h>
 #include <linux/completion.h>
@@ -23,8 +27,10 @@
 #include <linux/ptrace.h>
 #include <linux/uaccess.h>
 #include <linux/numa.h>
+#include <linux/sched/isolation.h>
 #include <trace/events/sched.h>
 
+
 static DEFINE_SPINLOCK(kthread_create_lock);
 static LIST_HEAD(kthread_create_list);
 struct task_struct *kthreadd_task;
@@ -46,7 +52,9 @@
 struct kthread {
 	unsigned long flags;
 	unsigned int cpu;
+	int (*threadfn)(void *);
 	void *data;
+	mm_segment_t oldfs;
 	struct completion parked;
 	struct completion exited;
 #ifdef CONFIG_BLK_CGROUP
@@ -172,6 +180,21 @@
 EXPORT_SYMBOL_GPL(kthread_freezable_should_stop);
 
 /**
+ * kthread_func - return the function specified on kthread creation
+ * @task: kthread task in question
+ *
+ * Returns NULL if the task is not a kthread.
+ */
+void *kthread_func(struct task_struct *task)
+{
+	struct kthread *kthread = __to_kthread(task);
+	if (kthread)
+		return kthread->threadfn;
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(kthread_func);
+
+/**
  * kthread_data - return data value specified on kthread creation
  * @task: kthread task in question
  *
@@ -183,6 +206,7 @@
 {
 	return to_kthread(task)->data;
 }
+EXPORT_SYMBOL_GPL(kthread_data);
 
 /**
  * kthread_probe_data - speculative version of kthread_data()
@@ -199,7 +223,7 @@
 	void *data = NULL;
 
 	if (kthread)
-		probe_kernel_read(&data, &kthread->data, sizeof(data));
+		copy_from_kernel_nofault(&data, &kthread->data, sizeof(data));
 	return data;
 }
 
@@ -264,6 +288,7 @@
 		do_exit(-ENOMEM);
 	}
 
+	self->threadfn = threadfn;
 	self->data = data;
 	init_completion(&self->exited);
 	init_completion(&self->parked);
@@ -380,7 +405,8 @@
 		 * The kernel thread should not inherit these properties.
 		 */
 		sched_setscheduler_nocheck(task, SCHED_NORMAL, &param);
-		set_cpus_allowed_ptr(task, cpu_all_mask);
+		set_cpus_allowed_ptr(task,
+				     housekeeping_cpumask(HK_FLAG_KTHREAD));
 	}
 	kfree(create);
 	return task;
@@ -475,7 +501,6 @@
  *	     to "name.*%u". Code fills in cpu number.
  *
  * Description: This helper function creates and names a kernel thread
- * The thread will be woken and put into park mode.
  */
 struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
 					  void *data, unsigned int cpu,
@@ -630,7 +655,7 @@
 	/* Setup a clean context for our children to inherit. */
 	set_task_comm(tsk, "kthreadd");
 	ignore_signals(tsk);
-	set_cpus_allowed_ptr(tsk, cpu_all_mask);
+	set_cpus_allowed_ptr(tsk, housekeeping_cpumask(HK_FLAG_KTHREAD));
 	set_mems_allowed(node_states[N_MEMORY]);
 
 	current->flags |= PF_NOFREEZE;
@@ -796,7 +821,7 @@
 
 /**
  * kthread_create_worker_on_cpu - create a kthread worker and bind it
- *	it to a given CPU and the associated NUMA node.
+ *	to a given CPU and the associated NUMA node.
  * @cpu: CPU number
  * @flags: flags modifying the default behavior of the worker
  * @namefmt: printf-style name for the kthread worker (task).
@@ -1279,6 +1304,65 @@
 }
 EXPORT_SYMBOL(kthread_destroy_worker);
 
+/**
+ * kthread_use_mm - make the calling kthread operate on an address space
+ * @mm: address space to operate on
+ */
+void kthread_use_mm(struct mm_struct *mm)
+{
+	struct mm_struct *active_mm;
+	struct task_struct *tsk = current;
+
+	WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD));
+	WARN_ON_ONCE(tsk->mm);
+
+	task_lock(tsk);
+	/* Hold off tlb flush IPIs while switching mm's */
+	local_irq_disable();
+	active_mm = tsk->active_mm;
+	if (active_mm != mm) {
+		mmgrab(mm);
+		tsk->active_mm = mm;
+	}
+	tsk->mm = mm;
+	switch_mm_irqs_off(active_mm, mm, tsk);
+	local_irq_enable();
+	task_unlock(tsk);
+#ifdef finish_arch_post_lock_switch
+	finish_arch_post_lock_switch();
+#endif
+
+	if (active_mm != mm)
+		mmdrop(active_mm);
+
+	to_kthread(tsk)->oldfs = force_uaccess_begin();
+}
+EXPORT_SYMBOL_GPL(kthread_use_mm);
+
+/**
+ * kthread_unuse_mm - reverse the effect of kthread_use_mm()
+ * @mm: address space to operate on
+ */
+void kthread_unuse_mm(struct mm_struct *mm)
+{
+	struct task_struct *tsk = current;
+
+	WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD));
+	WARN_ON_ONCE(!tsk->mm);
+
+	force_uaccess_end(to_kthread(tsk)->oldfs);
+
+	task_lock(tsk);
+	sync_mm_rss(mm);
+	local_irq_disable();
+	tsk->mm = NULL;
+	/* active_mm is still 'mm' */
+	enter_lazy_tlb(mm, tsk);
+	local_irq_enable();
+	task_unlock(tsk);
+}
+EXPORT_SYMBOL_GPL(kthread_unuse_mm);
+
 #ifdef CONFIG_BLK_CGROUP
 /**
  * kthread_associate_blkcg - associate blkcg to current kthread
@@ -1292,9 +1376,11 @@
  */
 void kthread_associate_blkcg(struct cgroup_subsys_state *css)
 {
-	struct kthread *kthread = __to_kthread(current);
+	struct kthread *kthread;
 
-
+	if (!(current->flags & PF_KTHREAD))
+		return;
+	kthread = to_kthread(current);
 	if (!kthread)
 		return;
 
@@ -1316,10 +1402,13 @@
  */
 struct cgroup_subsys_state *kthread_blkcg(void)
 {
-	struct kthread *kthread = __to_kthread(current);
+	struct kthread *kthread;
 
-	if (kthread)
-		return kthread->blkcg_css;
+	if (current->flags & PF_KTHREAD) {
+		kthread = to_kthread(current);
+		if (kthread)
+			return kthread->blkcg_css;
+	}
 	return NULL;
 }
 EXPORT_SYMBOL(kthread_blkcg);
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index e3acead..166d7bf 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -255,22 +255,22 @@
 	return single_open(filp, lstats_show, NULL);
 }
 
-static const struct file_operations lstats_fops = {
-	.open		= lstats_open,
-	.read		= seq_read,
-	.write		= lstats_write,
-	.llseek		= seq_lseek,
-	.release	= single_release,
+static const struct proc_ops lstats_proc_ops = {
+	.proc_open	= lstats_open,
+	.proc_read	= seq_read,
+	.proc_write	= lstats_write,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
 };
 
 static int __init init_lstats_procfs(void)
 {
-	proc_create("latency_stats", 0644, NULL, &lstats_fops);
+	proc_create("latency_stats", 0644, NULL, &lstats_proc_ops);
 	return 0;
 }
 
-int sysctl_latencytop(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+int sysctl_latencytop(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int err;
 
diff --git a/kernel/livepatch/Makefile b/kernel/livepatch/Makefile
index cf9b5bc..cf03d4b 100644
--- a/kernel/livepatch/Makefile
+++ b/kernel/livepatch/Makefile
@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_LIVEPATCH) += livepatch.o
 
-livepatch-objs := core.o patch.o shadow.o transition.o
+livepatch-objs := core.o patch.o shadow.o state.o transition.o
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index ab4a460..f76fdb9 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -22,6 +22,7 @@
 #include <asm/cacheflush.h>
 #include "core.h"
 #include "patch.h"
+#include "state.h"
 #include "transition.h"
 
 /*
@@ -190,18 +191,21 @@
 	return -EINVAL;
 }
 
-static int klp_resolve_symbols(Elf_Shdr *relasec, struct module *pmod)
+static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
+			       unsigned int symndx, Elf_Shdr *relasec,
+			       const char *sec_objname)
 {
-	int i, cnt, vmlinux, ret;
-	char objname[MODULE_NAME_LEN];
-	char symname[KSYM_NAME_LEN];
-	char *strtab = pmod->core_kallsyms.strtab;
+	int i, cnt, ret;
+	char sym_objname[MODULE_NAME_LEN];
+	char sym_name[KSYM_NAME_LEN];
 	Elf_Rela *relas;
 	Elf_Sym *sym;
 	unsigned long sympos, addr;
+	bool sym_vmlinux;
+	bool sec_vmlinux = !strcmp(sec_objname, "vmlinux");
 
 	/*
-	 * Since the field widths for objname and symname in the sscanf()
+	 * Since the field widths for sym_objname and sym_name in the sscanf()
 	 * call are hard-coded and correspond to MODULE_NAME_LEN and
 	 * KSYM_NAME_LEN respectively, we must make sure that MODULE_NAME_LEN
 	 * and KSYM_NAME_LEN have the values we expect them to have.
@@ -215,27 +219,40 @@
 	relas = (Elf_Rela *) relasec->sh_addr;
 	/* For each rela in this klp relocation section */
 	for (i = 0; i < relasec->sh_size / sizeof(Elf_Rela); i++) {
-		sym = pmod->core_kallsyms.symtab + ELF_R_SYM(relas[i].r_info);
+		sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
 		if (sym->st_shndx != SHN_LIVEPATCH) {
 			pr_err("symbol %s is not marked as a livepatch symbol\n",
 			       strtab + sym->st_name);
 			return -EINVAL;
 		}
 
-		/* Format: .klp.sym.objname.symname,sympos */
+		/* Format: .klp.sym.sym_objname.sym_name,sympos */
 		cnt = sscanf(strtab + sym->st_name,
 			     ".klp.sym.%55[^.].%127[^,],%lu",
-			     objname, symname, &sympos);
+			     sym_objname, sym_name, &sympos);
 		if (cnt != 3) {
 			pr_err("symbol %s has an incorrectly formatted name\n",
 			       strtab + sym->st_name);
 			return -EINVAL;
 		}
 
+		sym_vmlinux = !strcmp(sym_objname, "vmlinux");
+
+		/*
+		 * Prevent module-specific KLP rela sections from referencing
+		 * vmlinux symbols.  This helps prevent ordering issues with
+		 * module special section initializations.  Presumably such
+		 * symbols are exported and normal relas can be used instead.
+		 */
+		if (!sec_vmlinux && sym_vmlinux) {
+			pr_err("invalid access to vmlinux symbol '%s' from module-specific livepatch relocation section",
+			       sym_name);
+			return -EINVAL;
+		}
+
 		/* klp_find_object_symbol() treats a NULL objname as vmlinux */
-		vmlinux = !strcmp(objname, "vmlinux");
-		ret = klp_find_object_symbol(vmlinux ? NULL : objname,
-					     symname, sympos, &addr);
+		ret = klp_find_object_symbol(sym_vmlinux ? NULL : sym_objname,
+					     sym_name, sympos, &addr);
 		if (ret)
 			return ret;
 
@@ -245,54 +262,59 @@
 	return 0;
 }
 
-static int klp_write_object_relocations(struct module *pmod,
-					struct klp_object *obj)
+/*
+ * At a high-level, there are two types of klp relocation sections: those which
+ * reference symbols which live in vmlinux; and those which reference symbols
+ * which live in other modules.  This function is called for both types:
+ *
+ * 1) When a klp module itself loads, the module code calls this function to
+ *    write vmlinux-specific klp relocations (.klp.rela.vmlinux.* sections).
+ *    These relocations are written to the klp module text to allow the patched
+ *    code/data to reference unexported vmlinux symbols.  They're written as
+ *    early as possible to ensure that other module init code (.e.g.,
+ *    jump_label_apply_nops) can access any unexported vmlinux symbols which
+ *    might be referenced by the klp module's special sections.
+ *
+ * 2) When a to-be-patched module loads -- or is already loaded when a
+ *    corresponding klp module loads -- klp code calls this function to write
+ *    module-specific klp relocations (.klp.rela.{module}.* sections).  These
+ *    are written to the klp module text to allow the patched code/data to
+ *    reference symbols which live in the to-be-patched module or one of its
+ *    module dependencies.  Exported symbols are supported, in addition to
+ *    unexported symbols, in order to enable late module patching, which allows
+ *    the to-be-patched module to be loaded and patched sometime *after* the
+ *    klp module is loaded.
+ */
+int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs,
+			     const char *shstrtab, const char *strtab,
+			     unsigned int symndx, unsigned int secndx,
+			     const char *objname)
 {
-	int i, cnt, ret = 0;
-	const char *objname, *secname;
+	int cnt, ret;
 	char sec_objname[MODULE_NAME_LEN];
-	Elf_Shdr *sec;
+	Elf_Shdr *sec = sechdrs + secndx;
 
-	if (WARN_ON(!klp_is_object_loaded(obj)))
+	/*
+	 * Format: .klp.rela.sec_objname.section_name
+	 * See comment in klp_resolve_symbols() for an explanation
+	 * of the selected field width value.
+	 */
+	cnt = sscanf(shstrtab + sec->sh_name, ".klp.rela.%55[^.]",
+		     sec_objname);
+	if (cnt != 1) {
+		pr_err("section %s has an incorrectly formatted name\n",
+		       shstrtab + sec->sh_name);
 		return -EINVAL;
-
-	objname = klp_is_module(obj) ? obj->name : "vmlinux";
-
-	/* For each klp relocation section */
-	for (i = 1; i < pmod->klp_info->hdr.e_shnum; i++) {
-		sec = pmod->klp_info->sechdrs + i;
-		secname = pmod->klp_info->secstrings + sec->sh_name;
-		if (!(sec->sh_flags & SHF_RELA_LIVEPATCH))
-			continue;
-
-		/*
-		 * Format: .klp.rela.sec_objname.section_name
-		 * See comment in klp_resolve_symbols() for an explanation
-		 * of the selected field width value.
-		 */
-		cnt = sscanf(secname, ".klp.rela.%55[^.]", sec_objname);
-		if (cnt != 1) {
-			pr_err("section %s has an incorrectly formatted name\n",
-			       secname);
-			ret = -EINVAL;
-			break;
-		}
-
-		if (strcmp(objname, sec_objname))
-			continue;
-
-		ret = klp_resolve_symbols(sec, pmod);
-		if (ret)
-			break;
-
-		ret = apply_relocate_add(pmod->klp_info->sechdrs,
-					 pmod->core_kallsyms.strtab,
-					 pmod->klp_info->symndx, i, pmod);
-		if (ret)
-			break;
 	}
 
-	return ret;
+	if (strcmp(objname ? objname : "vmlinux", sec_objname))
+		return 0;
+
+	ret = klp_resolve_symbols(sechdrs, strtab, symndx, sec, sec_objname);
+	if (ret)
+		return ret;
+
+	return apply_relocate_add(sechdrs, strtab, symndx, secndx, pmod);
 }
 
 /*
@@ -632,7 +654,7 @@
  * The operation must be completed by calling klp_free_patch_finish()
  * outside klp_mutex.
  */
-void klp_free_patch_start(struct klp_patch *patch)
+static void klp_free_patch_start(struct klp_patch *patch)
 {
 	if (!list_empty(&patch->list))
 		list_del(&patch->list);
@@ -677,6 +699,23 @@
 	klp_free_patch_finish(patch);
 }
 
+void klp_free_patch_async(struct klp_patch *patch)
+{
+	klp_free_patch_start(patch);
+	schedule_work(&patch->free_work);
+}
+
+void klp_free_replaced_patches_async(struct klp_patch *new_patch)
+{
+	struct klp_patch *old_patch, *tmp_patch;
+
+	klp_for_each_patch_safe(old_patch, tmp_patch) {
+		if (old_patch == new_patch)
+			return;
+		klp_free_patch_async(old_patch);
+	}
+}
+
 static int klp_init_func(struct klp_object *obj, struct klp_func *func)
 {
 	if (!func->old_name)
@@ -706,10 +745,27 @@
 			   func->old_sympos ? func->old_sympos : 1);
 }
 
-/* Arches may override this to finish any remaining arch-specific tasks */
-void __weak arch_klp_init_object_loaded(struct klp_patch *patch,
-					struct klp_object *obj)
+static int klp_apply_object_relocs(struct klp_patch *patch,
+				   struct klp_object *obj)
 {
+	int i, ret;
+	struct klp_modinfo *info = patch->mod->klp_info;
+
+	for (i = 1; i < info->hdr.e_shnum; i++) {
+		Elf_Shdr *sec = info->sechdrs + i;
+
+		if (!(sec->sh_flags & SHF_RELA_LIVEPATCH))
+			continue;
+
+		ret = klp_apply_section_relocs(patch->mod, info->sechdrs,
+					       info->secstrings,
+					       patch->mod->core_kallsyms.strtab,
+					       info->symndx, i, obj->name);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 /* parts of the initialization that is done only when the object is loaded */
@@ -719,21 +775,18 @@
 	struct klp_func *func;
 	int ret;
 
-	mutex_lock(&text_mutex);
-
-	module_disable_ro(patch->mod);
-	ret = klp_write_object_relocations(patch->mod, obj);
-	if (ret) {
-		module_enable_ro(patch->mod, true);
-		mutex_unlock(&text_mutex);
-		return ret;
+	if (klp_is_module(obj)) {
+		/*
+		 * Only write module-specific relocations here
+		 * (.klp.rela.{module}.*).  vmlinux-specific relocations were
+		 * written earlier during the initialization of the klp module
+		 * itself.
+		 */
+		ret = klp_apply_object_relocs(patch, obj);
+		if (ret)
+			return ret;
 	}
 
-	arch_klp_init_object_loaded(patch, obj);
-	module_enable_ro(patch->mod, true);
-
-	mutex_unlock(&text_mutex);
-
 	klp_for_each_func(obj, func) {
 		ret = klp_find_object_symbol(obj->name, func->old_name,
 					     func->old_sympos,
@@ -992,6 +1045,13 @@
 
 	mutex_lock(&klp_mutex);
 
+	if (!klp_is_patch_compatible(patch)) {
+		pr_err("Livepatch patch (%s) is not compatible with the already installed livepatches.\n",
+			patch->mod->name);
+		mutex_unlock(&klp_mutex);
+		return -EINVAL;
+	}
+
 	ret = klp_init_patch_early(patch);
 	if (ret) {
 		mutex_unlock(&klp_mutex);
@@ -1022,12 +1082,13 @@
 EXPORT_SYMBOL_GPL(klp_enable_patch);
 
 /*
- * This function removes replaced patches.
+ * This function unpatches objects from the replaced livepatches.
  *
  * We could be pretty aggressive here. It is called in the situation where
- * these structures are no longer accessible. All functions are redirected
- * by the klp_transition_patch. They use either a new code or they are in
- * the original code because of the special nop function patches.
+ * these structures are no longer accessed from the ftrace handler.
+ * All functions are redirected by the klp_transition_patch. They
+ * use either a new code or they are in the original code because
+ * of the special nop function patches.
  *
  * The only exception is when the transition was forced. In this case,
  * klp_ftrace_handler() might still see the replaced patch on the stack.
@@ -1035,18 +1096,16 @@
  * thanks to RCU. We only have to keep the patches on the system. Also
  * this is handled transparently by patch->module_put.
  */
-void klp_discard_replaced_patches(struct klp_patch *new_patch)
+void klp_unpatch_replaced_patches(struct klp_patch *new_patch)
 {
-	struct klp_patch *old_patch, *tmp_patch;
+	struct klp_patch *old_patch;
 
-	klp_for_each_patch_safe(old_patch, tmp_patch) {
+	klp_for_each_patch(old_patch) {
 		if (old_patch == new_patch)
 			return;
 
 		old_patch->enabled = false;
 		klp_unpatch_objects(old_patch);
-		klp_free_patch_start(old_patch);
-		schedule_work(&old_patch->free_work);
 	}
 }
 
@@ -1115,6 +1174,11 @@
 	if (WARN_ON(mod->state != MODULE_STATE_COMING))
 		return -EINVAL;
 
+	if (!strcmp(mod->name, "vmlinux")) {
+		pr_err("vmlinux.ko: invalid module name");
+		return -EINVAL;
+	}
+
 	mutex_lock(&klp_mutex);
 	/*
 	 * Each module has to know that klp_module_coming()
diff --git a/kernel/livepatch/core.h b/kernel/livepatch/core.h
index ec43a40..38209c7 100644
--- a/kernel/livepatch/core.h
+++ b/kernel/livepatch/core.h
@@ -13,8 +13,9 @@
 #define klp_for_each_patch(patch)	\
 	list_for_each_entry(patch, &klp_patches, list)
 
-void klp_free_patch_start(struct klp_patch *patch);
-void klp_discard_replaced_patches(struct klp_patch *new_patch);
+void klp_free_patch_async(struct klp_patch *patch);
+void klp_free_replaced_patches_async(struct klp_patch *new_patch);
+void klp_unpatch_replaced_patches(struct klp_patch *new_patch);
 void klp_discard_nops(struct klp_patch *new_patch);
 
 static inline bool klp_is_object_loaded(struct klp_object *obj)
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index bd43537..b552cf2 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -196,7 +196,8 @@
 		ops->fops.func = klp_ftrace_handler;
 		ops->fops.flags = FTRACE_OPS_FL_SAVE_REGS |
 				  FTRACE_OPS_FL_DYNAMIC |
-				  FTRACE_OPS_FL_IPMODIFY;
+				  FTRACE_OPS_FL_IPMODIFY |
+				  FTRACE_OPS_FL_PERMANENT;
 
 		list_add(&ops->node, &klp_ops);
 
diff --git a/kernel/livepatch/state.c b/kernel/livepatch/state.c
new file mode 100644
index 0000000..2565d03
--- /dev/null
+++ b/kernel/livepatch/state.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * system_state.c - State of the system modified by livepatches
+ *
+ * Copyright (C) 2019 SUSE
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/livepatch.h>
+#include "core.h"
+#include "state.h"
+#include "transition.h"
+
+#define klp_for_each_state(patch, state)		\
+	for (state = patch->states; state && state->id; state++)
+
+/**
+ * klp_get_state() - get information about system state modified by
+ *	the given patch
+ * @patch:	livepatch that modifies the given system state
+ * @id:		custom identifier of the modified system state
+ *
+ * Checks whether the given patch modifies the given system state.
+ *
+ * The function can be called either from pre/post (un)patch
+ * callbacks or from the kernel code added by the livepatch.
+ *
+ * Return: pointer to struct klp_state when found, otherwise NULL.
+ */
+struct klp_state *klp_get_state(struct klp_patch *patch, unsigned long id)
+{
+	struct klp_state *state;
+
+	klp_for_each_state(patch, state) {
+		if (state->id == id)
+			return state;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(klp_get_state);
+
+/**
+ * klp_get_prev_state() - get information about system state modified by
+ *	the already installed livepatches
+ * @id:		custom identifier of the modified system state
+ *
+ * Checks whether already installed livepatches modify the given
+ * system state.
+ *
+ * The same system state can be modified by more non-cumulative
+ * livepatches. It is expected that the latest livepatch has
+ * the most up-to-date information.
+ *
+ * The function can be called only during transition when a new
+ * livepatch is being enabled or when such a transition is reverted.
+ * It is typically called only from pre/post (un)patch
+ * callbacks.
+ *
+ * Return: pointer to the latest struct klp_state from already
+ *	installed livepatches, NULL when not found.
+ */
+struct klp_state *klp_get_prev_state(unsigned long id)
+{
+	struct klp_patch *patch;
+	struct klp_state *state, *last_state = NULL;
+
+	if (WARN_ON_ONCE(!klp_transition_patch))
+		return NULL;
+
+	klp_for_each_patch(patch) {
+		if (patch == klp_transition_patch)
+			goto out;
+
+		state = klp_get_state(patch, id);
+		if (state)
+			last_state = state;
+	}
+
+out:
+	return last_state;
+}
+EXPORT_SYMBOL_GPL(klp_get_prev_state);
+
+/* Check if the patch is able to deal with the existing system state. */
+static bool klp_is_state_compatible(struct klp_patch *patch,
+				    struct klp_state *old_state)
+{
+	struct klp_state *state;
+
+	state = klp_get_state(patch, old_state->id);
+
+	/* A cumulative livepatch must handle all already modified states. */
+	if (!state)
+		return !patch->replace;
+
+	return state->version >= old_state->version;
+}
+
+/*
+ * Check that the new livepatch will not break the existing system states.
+ * Cumulative patches must handle all already modified states.
+ * Non-cumulative patches can touch already modified states.
+ */
+bool klp_is_patch_compatible(struct klp_patch *patch)
+{
+	struct klp_patch *old_patch;
+	struct klp_state *old_state;
+
+	klp_for_each_patch(old_patch) {
+		klp_for_each_state(old_patch, old_state) {
+			if (!klp_is_state_compatible(patch, old_state))
+				return false;
+		}
+	}
+
+	return true;
+}
diff --git a/kernel/livepatch/state.h b/kernel/livepatch/state.h
new file mode 100644
index 0000000..49d9c16
--- /dev/null
+++ b/kernel/livepatch/state.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LIVEPATCH_STATE_H
+#define _LIVEPATCH_STATE_H
+
+#include <linux/livepatch.h>
+
+bool klp_is_patch_compatible(struct klp_patch *patch);
+
+#endif /* _LIVEPATCH_STATE_H */
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index cdf318d..f6310f8 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -78,7 +78,7 @@
 		 klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
 
 	if (klp_transition_patch->replace && klp_target_state == KLP_PATCHED) {
-		klp_discard_replaced_patches(klp_transition_patch);
+		klp_unpatch_replaced_patches(klp_transition_patch);
 		klp_discard_nops(klp_transition_patch);
 	}
 
@@ -446,14 +446,14 @@
 	klp_complete_transition();
 
 	/*
-	 * It would make more sense to free the patch in
+	 * It would make more sense to free the unused patches in
 	 * klp_complete_transition() but it is called also
 	 * from klp_cancel_transition().
 	 */
-	if (!patch->enabled) {
-		klp_free_patch_start(patch);
-		schedule_work(&patch->free_work);
-	}
+	if (!patch->enabled)
+		klp_free_patch_async(patch);
+	else if (patch->replace)
+		klp_free_replaced_patches_async(patch);
 }
 
 /*
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index 45452fa..6d11cfb 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -5,6 +5,9 @@
 
 obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
 
+# Avoid recursion lockdep -> KCSAN -> ... -> lockdep.
+KCSAN_SANITIZE_lockdep.o := n
+
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_lockdep_proc.o = $(CC_FLAGS_FTRACE)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 3ec8fd2..af4b354 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -76,6 +76,23 @@
 #define lock_stat 0
 #endif
 
+DEFINE_PER_CPU(unsigned int, lockdep_recursion);
+EXPORT_PER_CPU_SYMBOL_GPL(lockdep_recursion);
+
+static __always_inline bool lockdep_enabled(void)
+{
+	if (!debug_locks)
+		return false;
+
+	if (this_cpu_read(lockdep_recursion))
+		return false;
+
+	if (current->lockdep_recursion)
+		return false;
+
+	return true;
+}
+
 /*
  * lockdep_lock: protects the lockdep graph, the hashes and the
  *               class/list/hash allocators.
@@ -84,12 +101,41 @@
  * to use a raw spinlock - we really dont want the spinlock
  * code to recurse back into the lockdep code...
  */
-static arch_spinlock_t lockdep_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
+static arch_spinlock_t __lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
+static struct task_struct *__owner;
+
+static inline void lockdep_lock(void)
+{
+	DEBUG_LOCKS_WARN_ON(!irqs_disabled());
+
+	__this_cpu_inc(lockdep_recursion);
+	arch_spin_lock(&__lock);
+	__owner = current;
+}
+
+static inline void lockdep_unlock(void)
+{
+	DEBUG_LOCKS_WARN_ON(!irqs_disabled());
+
+	if (debug_locks && DEBUG_LOCKS_WARN_ON(__owner != current))
+		return;
+
+	__owner = NULL;
+	arch_spin_unlock(&__lock);
+	__this_cpu_dec(lockdep_recursion);
+}
+
+static inline bool lockdep_assert_locked(void)
+{
+	return DEBUG_LOCKS_WARN_ON(__owner != current);
+}
+
 static struct task_struct *lockdep_selftest_task_struct;
 
+
 static int graph_lock(void)
 {
-	arch_spin_lock(&lockdep_lock);
+	lockdep_lock();
 	/*
 	 * Make sure that if another CPU detected a bug while
 	 * walking the graph we dont change it (while the other
@@ -97,27 +143,15 @@
 	 * dropped already)
 	 */
 	if (!debug_locks) {
-		arch_spin_unlock(&lockdep_lock);
+		lockdep_unlock();
 		return 0;
 	}
-	/* prevent any recursions within lockdep from causing deadlocks */
-	current->lockdep_recursion++;
 	return 1;
 }
 
-static inline int graph_unlock(void)
+static inline void graph_unlock(void)
 {
-	if (debug_locks && !arch_spin_is_locked(&lockdep_lock)) {
-		/*
-		 * The lockdep graph lock isn't locked while we expect it to
-		 * be, we're confused now, bye!
-		 */
-		return DEBUG_LOCKS_WARN_ON(1);
-	}
-
-	current->lockdep_recursion--;
-	arch_spin_unlock(&lockdep_lock);
-	return 0;
+	lockdep_unlock();
 }
 
 /*
@@ -128,7 +162,7 @@
 {
 	int ret = debug_locks_off();
 
-	arch_spin_unlock(&lockdep_lock);
+	lockdep_unlock();
 
 	return ret;
 }
@@ -147,6 +181,7 @@
 #define KEYHASH_SIZE		(1UL << KEYHASH_BITS)
 static struct hlist_head lock_keys_hash[KEYHASH_SIZE];
 unsigned long nr_lock_classes;
+unsigned long nr_zapped_classes;
 #ifndef CONFIG_DEBUG_LOCKDEP
 static
 #endif
@@ -356,6 +391,21 @@
 static struct hlist_head chainhash_table[CHAINHASH_SIZE];
 
 /*
+ * the id of held_lock
+ */
+static inline u16 hlock_id(struct held_lock *hlock)
+{
+	BUILD_BUG_ON(MAX_LOCKDEP_KEYS_BITS + 2 > 16);
+
+	return (hlock->class_idx | (hlock->read << MAX_LOCKDEP_KEYS_BITS));
+}
+
+static inline unsigned int chain_hlock_class_idx(u16 hlock_id)
+{
+	return hlock_id & (MAX_LOCKDEP_KEYS - 1);
+}
+
+/*
  * The hash key of the lock dependency chains is a hash itself too:
  * it's a hash of all locks taken up to that lock, including that lock.
  * It's a 64-bit hash, because it's important for the keys to be
@@ -377,17 +427,16 @@
 	task->lockdep_recursion = 0;
 }
 
-void lockdep_off(void)
+static __always_inline void lockdep_recursion_inc(void)
 {
-	current->lockdep_recursion++;
+	__this_cpu_inc(lockdep_recursion);
 }
-EXPORT_SYMBOL(lockdep_off);
 
-void lockdep_on(void)
+static __always_inline void lockdep_recursion_finish(void)
 {
-	current->lockdep_recursion--;
+	if (WARN_ON_ONCE(__this_cpu_dec_return(lockdep_recursion)))
+		__this_cpu_write(lockdep_recursion, 0);
 }
-EXPORT_SYMBOL(lockdep_on);
 
 void lockdep_set_selftest_task(struct task_struct *task)
 {
@@ -460,7 +509,7 @@
 	struct hlist_node	hash_entry;
 	u32			hash;
 	u32			nr_entries;
-	unsigned long		entries[0] __aligned(sizeof(unsigned long));
+	unsigned long		entries[] __aligned(sizeof(unsigned long));
 };
 #define LOCK_TRACE_SIZE_IN_LONGS				\
 	(sizeof(struct lock_trace) / sizeof(unsigned long))
@@ -575,6 +624,9 @@
 #include "lockdep_states.h"
 #undef LOCKDEP_STATE
 	[LOCK_USED] = "INITIAL USE",
+	[LOCK_USED_READ] = "INITIAL READ USE",
+	/* abused as string storage for verify_lock_unused() */
+	[LOCK_USAGE_STATES] = "IN-NMI",
 };
 #endif
 
@@ -653,7 +705,9 @@
 
 	printk(KERN_CONT " (");
 	__print_lock_name(class);
-	printk(KERN_CONT "){%s}", usage);
+	printk(KERN_CONT "){%s}-{%d:%d}", usage,
+			class->wait_type_outer ?: class->wait_type_inner,
+			class->wait_type_inner);
 }
 
 static void print_lockdep_cache(struct lockdep_map *lock)
@@ -787,7 +841,8 @@
 	return count + 1;
 }
 
-static inline struct lock_class *
+/* used from NMI context -- must be lockless */
+static noinstr struct lock_class *
 look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
 {
 	struct lockdep_subclass_key *key;
@@ -795,12 +850,14 @@
 	struct lock_class *class;
 
 	if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
+		instrumentation_begin();
 		debug_locks_off();
 		printk(KERN_ERR
 			"BUG: looking up invalid subclass: %u\n", subclass);
 		printk(KERN_ERR
 			"turning off the locking correctness validator.\n");
 		dump_stack();
+		instrumentation_end();
 		return NULL;
 	}
 
@@ -830,7 +887,7 @@
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
 		return NULL;
 
-	hlist_for_each_entry_rcu(class, hash_head, hash_entry) {
+	hlist_for_each_entry_rcu_notrace(class, hash_head, hash_entry) {
 		if (class->key == key) {
 			/*
 			 * Huh! same key, different name? Did someone trample
@@ -1071,13 +1128,15 @@
 
 #endif /* CONFIG_DEBUG_LOCKDEP */
 
+static void init_chain_block_buckets(void);
+
 /*
  * Initialize the lock_classes[] array elements, the free_lock_classes list
  * and also the delayed_free structure.
  */
 static void init_data_structures_once(void)
 {
-	static bool ds_initialized, rcu_head_initialized;
+	static bool __read_mostly ds_initialized, rcu_head_initialized;
 	int i;
 
 	if (likely(rcu_head_initialized))
@@ -1101,6 +1160,7 @@
 		INIT_LIST_HEAD(&lock_classes[i].locks_after);
 		INIT_LIST_HEAD(&lock_classes[i].locks_before);
 	}
+	init_chain_block_buckets();
 }
 
 static inline struct hlist_head *keyhashentry(const struct lock_class_key *key)
@@ -1231,6 +1291,9 @@
 	WARN_ON_ONCE(!list_empty(&class->locks_before));
 	WARN_ON_ONCE(!list_empty(&class->locks_after));
 	class->name_version = count_matching_names(class);
+	class->wait_type_inner = lock->wait_type_inner;
+	class->wait_type_outer = lock->wait_type_outer;
+	class->lock_type = lock->lock_type;
 	/*
 	 * We use RCU's safe list-add method to make
 	 * parallel walking of the hash-list safe:
@@ -1302,7 +1365,7 @@
  */
 static int add_lock_to_list(struct lock_class *this,
 			    struct lock_class *links_to, struct list_head *head,
-			    unsigned long ip, int distance,
+			    unsigned long ip, u16 distance, u8 dep,
 			    const struct lock_trace *trace)
 {
 	struct lock_list *entry;
@@ -1316,6 +1379,7 @@
 
 	entry->class = this;
 	entry->links_to = links_to;
+	entry->dep = dep;
 	entry->distance = distance;
 	entry->trace = trace;
 	/*
@@ -1403,23 +1467,19 @@
 	return (cq->rear - cq->front) & CQ_MASK;
 }
 
-static inline void mark_lock_accessed(struct lock_list *lock,
-					struct lock_list *parent)
+static inline void mark_lock_accessed(struct lock_list *lock)
 {
-	unsigned long nr;
-
-	nr = lock - list_entries;
-	WARN_ON(nr >= ARRAY_SIZE(list_entries)); /* Out-of-bounds, input fail */
-	lock->parent = parent;
 	lock->class->dep_gen_id = lockdep_dependency_gen_id;
 }
 
+static inline void visit_lock_entry(struct lock_list *lock,
+				    struct lock_list *parent)
+{
+	lock->parent = parent;
+}
+
 static inline unsigned long lock_accessed(struct lock_list *lock)
 {
-	unsigned long nr;
-
-	nr = lock - list_entries;
-	WARN_ON(nr >= ARRAY_SIZE(list_entries)); /* Out-of-bounds, input fail */
 	return lock->class->dep_gen_id == lockdep_dependency_gen_id;
 }
 
@@ -1453,85 +1513,283 @@
 
 	return lock_class + offset;
 }
+/*
+ * Return values of a bfs search:
+ *
+ * BFS_E* indicates an error
+ * BFS_R* indicates a result (match or not)
+ *
+ * BFS_EINVALIDNODE: Find a invalid node in the graph.
+ *
+ * BFS_EQUEUEFULL: The queue is full while doing the bfs.
+ *
+ * BFS_RMATCH: Find the matched node in the graph, and put that node into
+ *             *@target_entry.
+ *
+ * BFS_RNOMATCH: Haven't found the matched node and keep *@target_entry
+ *               _unchanged_.
+ */
+enum bfs_result {
+	BFS_EINVALIDNODE = -2,
+	BFS_EQUEUEFULL = -1,
+	BFS_RMATCH = 0,
+	BFS_RNOMATCH = 1,
+};
 
 /*
- * Forward- or backward-dependency search, used for both circular dependency
- * checking and hardirq-unsafe/softirq-unsafe checking.
+ * bfs_result < 0 means error
  */
-static int __bfs(struct lock_list *source_entry,
-		 void *data,
-		 int (*match)(struct lock_list *entry, void *data),
-		 struct lock_list **target_entry,
-		 int offset)
+static inline bool bfs_error(enum bfs_result res)
 {
-	struct lock_list *entry;
-	struct lock_list *lock;
-	struct list_head *head;
+	return res < 0;
+}
+
+/*
+ * DEP_*_BIT in lock_list::dep
+ *
+ * For dependency @prev -> @next:
+ *
+ *   SR: @prev is shared reader (->read != 0) and @next is recursive reader
+ *       (->read == 2)
+ *   ER: @prev is exclusive locker (->read == 0) and @next is recursive reader
+ *   SN: @prev is shared reader and @next is non-recursive locker (->read != 2)
+ *   EN: @prev is exclusive locker and @next is non-recursive locker
+ *
+ * Note that we define the value of DEP_*_BITs so that:
+ *   bit0 is prev->read == 0
+ *   bit1 is next->read != 2
+ */
+#define DEP_SR_BIT (0 + (0 << 1)) /* 0 */
+#define DEP_ER_BIT (1 + (0 << 1)) /* 1 */
+#define DEP_SN_BIT (0 + (1 << 1)) /* 2 */
+#define DEP_EN_BIT (1 + (1 << 1)) /* 3 */
+
+#define DEP_SR_MASK (1U << (DEP_SR_BIT))
+#define DEP_ER_MASK (1U << (DEP_ER_BIT))
+#define DEP_SN_MASK (1U << (DEP_SN_BIT))
+#define DEP_EN_MASK (1U << (DEP_EN_BIT))
+
+static inline unsigned int
+__calc_dep_bit(struct held_lock *prev, struct held_lock *next)
+{
+	return (prev->read == 0) + ((next->read != 2) << 1);
+}
+
+static inline u8 calc_dep(struct held_lock *prev, struct held_lock *next)
+{
+	return 1U << __calc_dep_bit(prev, next);
+}
+
+/*
+ * calculate the dep_bit for backwards edges. We care about whether @prev is
+ * shared and whether @next is recursive.
+ */
+static inline unsigned int
+__calc_dep_bitb(struct held_lock *prev, struct held_lock *next)
+{
+	return (next->read != 2) + ((prev->read == 0) << 1);
+}
+
+static inline u8 calc_depb(struct held_lock *prev, struct held_lock *next)
+{
+	return 1U << __calc_dep_bitb(prev, next);
+}
+
+/*
+ * Initialize a lock_list entry @lock belonging to @class as the root for a BFS
+ * search.
+ */
+static inline void __bfs_init_root(struct lock_list *lock,
+				   struct lock_class *class)
+{
+	lock->class = class;
+	lock->parent = NULL;
+	lock->only_xr = 0;
+}
+
+/*
+ * Initialize a lock_list entry @lock based on a lock acquisition @hlock as the
+ * root for a BFS search.
+ *
+ * ->only_xr of the initial lock node is set to @hlock->read == 2, to make sure
+ * that <prev> -> @hlock and @hlock -> <whatever __bfs() found> is not -(*R)->
+ * and -(S*)->.
+ */
+static inline void bfs_init_root(struct lock_list *lock,
+				 struct held_lock *hlock)
+{
+	__bfs_init_root(lock, hlock_class(hlock));
+	lock->only_xr = (hlock->read == 2);
+}
+
+/*
+ * Similar to bfs_init_root() but initialize the root for backwards BFS.
+ *
+ * ->only_xr of the initial lock node is set to @hlock->read != 0, to make sure
+ * that <next> -> @hlock and @hlock -> <whatever backwards BFS found> is not
+ * -(*S)-> and -(R*)-> (reverse order of -(*R)-> and -(S*)->).
+ */
+static inline void bfs_init_rootb(struct lock_list *lock,
+				  struct held_lock *hlock)
+{
+	__bfs_init_root(lock, hlock_class(hlock));
+	lock->only_xr = (hlock->read != 0);
+}
+
+static inline struct lock_list *__bfs_next(struct lock_list *lock, int offset)
+{
+	if (!lock || !lock->parent)
+		return NULL;
+
+	return list_next_or_null_rcu(get_dep_list(lock->parent, offset),
+				     &lock->entry, struct lock_list, entry);
+}
+
+/*
+ * Breadth-First Search to find a strong path in the dependency graph.
+ *
+ * @source_entry: the source of the path we are searching for.
+ * @data: data used for the second parameter of @match function
+ * @match: match function for the search
+ * @target_entry: pointer to the target of a matched path
+ * @offset: the offset to struct lock_class to determine whether it is
+ *          locks_after or locks_before
+ *
+ * We may have multiple edges (considering different kinds of dependencies,
+ * e.g. ER and SN) between two nodes in the dependency graph. But
+ * only the strong dependency path in the graph is relevant to deadlocks. A
+ * strong dependency path is a dependency path that doesn't have two adjacent
+ * dependencies as -(*R)-> -(S*)->, please see:
+ *
+ *         Documentation/locking/lockdep-design.rst
+ *
+ * for more explanation of the definition of strong dependency paths
+ *
+ * In __bfs(), we only traverse in the strong dependency path:
+ *
+ *     In lock_list::only_xr, we record whether the previous dependency only
+ *     has -(*R)-> in the search, and if it does (prev only has -(*R)->), we
+ *     filter out any -(S*)-> in the current dependency and after that, the
+ *     ->only_xr is set according to whether we only have -(*R)-> left.
+ */
+static enum bfs_result __bfs(struct lock_list *source_entry,
+			     void *data,
+			     bool (*match)(struct lock_list *entry, void *data),
+			     struct lock_list **target_entry,
+			     int offset)
+{
 	struct circular_queue *cq = &lock_cq;
-	int ret = 1;
+	struct lock_list *lock = NULL;
+	struct lock_list *entry;
+	struct list_head *head;
+	unsigned int cq_depth;
+	bool first;
 
-	if (match(source_entry, data)) {
-		*target_entry = source_entry;
-		ret = 0;
-		goto exit;
-	}
-
-	head = get_dep_list(source_entry, offset);
-	if (list_empty(head))
-		goto exit;
+	lockdep_assert_locked();
 
 	__cq_init(cq);
 	__cq_enqueue(cq, source_entry);
 
-	while ((lock = __cq_dequeue(cq))) {
+	while ((lock = __bfs_next(lock, offset)) || (lock = __cq_dequeue(cq))) {
+		if (!lock->class)
+			return BFS_EINVALIDNODE;
 
-		if (!lock->class) {
-			ret = -2;
-			goto exit;
+		/*
+		 * Step 1: check whether we already finish on this one.
+		 *
+		 * If we have visited all the dependencies from this @lock to
+		 * others (iow, if we have visited all lock_list entries in
+		 * @lock->class->locks_{after,before}) we skip, otherwise go
+		 * and visit all the dependencies in the list and mark this
+		 * list accessed.
+		 */
+		if (lock_accessed(lock))
+			continue;
+		else
+			mark_lock_accessed(lock);
+
+		/*
+		 * Step 2: check whether prev dependency and this form a strong
+		 *         dependency path.
+		 */
+		if (lock->parent) { /* Parent exists, check prev dependency */
+			u8 dep = lock->dep;
+			bool prev_only_xr = lock->parent->only_xr;
+
+			/*
+			 * Mask out all -(S*)-> if we only have *R in previous
+			 * step, because -(*R)-> -(S*)-> don't make up a strong
+			 * dependency.
+			 */
+			if (prev_only_xr)
+				dep &= ~(DEP_SR_MASK | DEP_SN_MASK);
+
+			/* If nothing left, we skip */
+			if (!dep)
+				continue;
+
+			/* If there are only -(*R)-> left, set that for the next step */
+			lock->only_xr = !(dep & (DEP_SN_MASK | DEP_EN_MASK));
 		}
 
+		/*
+		 * Step 3: we haven't visited this and there is a strong
+		 *         dependency path to this, so check with @match.
+		 */
+		if (match(lock, data)) {
+			*target_entry = lock;
+			return BFS_RMATCH;
+		}
+
+		/*
+		 * Step 4: if not match, expand the path by adding the
+		 *         forward or backwards dependencis in the search
+		 *
+		 */
+		first = true;
 		head = get_dep_list(lock, offset);
-
-		DEBUG_LOCKS_WARN_ON(!irqs_disabled());
-
 		list_for_each_entry_rcu(entry, head, entry) {
-			if (!lock_accessed(entry)) {
-				unsigned int cq_depth;
-				mark_lock_accessed(entry, lock);
-				if (match(entry, data)) {
-					*target_entry = entry;
-					ret = 0;
-					goto exit;
-				}
+			visit_lock_entry(entry, lock);
 
-				if (__cq_enqueue(cq, entry)) {
-					ret = -1;
-					goto exit;
-				}
-				cq_depth = __cq_get_elem_count(cq);
-				if (max_bfs_queue_depth < cq_depth)
-					max_bfs_queue_depth = cq_depth;
-			}
+			/*
+			 * Note we only enqueue the first of the list into the
+			 * queue, because we can always find a sibling
+			 * dependency from one (see __bfs_next()), as a result
+			 * the space of queue is saved.
+			 */
+			if (!first)
+				continue;
+
+			first = false;
+
+			if (__cq_enqueue(cq, entry))
+				return BFS_EQUEUEFULL;
+
+			cq_depth = __cq_get_elem_count(cq);
+			if (max_bfs_queue_depth < cq_depth)
+				max_bfs_queue_depth = cq_depth;
 		}
 	}
-exit:
-	return ret;
+
+	return BFS_RNOMATCH;
 }
 
-static inline int __bfs_forwards(struct lock_list *src_entry,
-			void *data,
-			int (*match)(struct lock_list *entry, void *data),
-			struct lock_list **target_entry)
+static inline enum bfs_result
+__bfs_forwards(struct lock_list *src_entry,
+	       void *data,
+	       bool (*match)(struct lock_list *entry, void *data),
+	       struct lock_list **target_entry)
 {
 	return __bfs(src_entry, data, match, target_entry,
 		     offsetof(struct lock_class, locks_after));
 
 }
 
-static inline int __bfs_backwards(struct lock_list *src_entry,
-			void *data,
-			int (*match)(struct lock_list *entry, void *data),
-			struct lock_list **target_entry)
+static inline enum bfs_result
+__bfs_backwards(struct lock_list *src_entry,
+		void *data,
+		bool (*match)(struct lock_list *entry, void *data),
+		struct lock_list **target_entry)
 {
 	return __bfs(src_entry, data, match, target_entry,
 		     offsetof(struct lock_class, locks_before));
@@ -1641,15 +1899,72 @@
 	print_circular_bug_entry(entry, depth);
 }
 
-static inline int class_equal(struct lock_list *entry, void *data)
+/*
+ * We are about to add A -> B into the dependency graph, and in __bfs() a
+ * strong dependency path A -> .. -> B is found: hlock_class equals
+ * entry->class.
+ *
+ * If A -> .. -> B can replace A -> B in any __bfs() search (means the former
+ * is _stronger_ than or equal to the latter), we consider A -> B as redundant.
+ * For example if A -> .. -> B is -(EN)-> (i.e. A -(E*)-> .. -(*N)-> B), and A
+ * -> B is -(ER)-> or -(EN)->, then we don't need to add A -> B into the
+ * dependency graph, as any strong path ..-> A -> B ->.. we can get with
+ * having dependency A -> B, we could already get a equivalent path ..-> A ->
+ * .. -> B -> .. with A -> .. -> B. Therefore A -> B is reduntant.
+ *
+ * We need to make sure both the start and the end of A -> .. -> B is not
+ * weaker than A -> B. For the start part, please see the comment in
+ * check_redundant(). For the end part, we need:
+ *
+ * Either
+ *
+ *     a) A -> B is -(*R)-> (everything is not weaker than that)
+ *
+ * or
+ *
+ *     b) A -> .. -> B is -(*N)-> (nothing is stronger than this)
+ *
+ */
+static inline bool hlock_equal(struct lock_list *entry, void *data)
 {
-	return entry->class == data;
+	struct held_lock *hlock = (struct held_lock *)data;
+
+	return hlock_class(hlock) == entry->class && /* Found A -> .. -> B */
+	       (hlock->read == 2 ||  /* A -> B is -(*R)-> */
+		!entry->only_xr); /* A -> .. -> B is -(*N)-> */
+}
+
+/*
+ * We are about to add B -> A into the dependency graph, and in __bfs() a
+ * strong dependency path A -> .. -> B is found: hlock_class equals
+ * entry->class.
+ *
+ * We will have a deadlock case (conflict) if A -> .. -> B -> A is a strong
+ * dependency cycle, that means:
+ *
+ * Either
+ *
+ *     a) B -> A is -(E*)->
+ *
+ * or
+ *
+ *     b) A -> .. -> B is -(*N)-> (i.e. A -> .. -(*N)-> B)
+ *
+ * as then we don't have -(*R)-> -(S*)-> in the cycle.
+ */
+static inline bool hlock_conflict(struct lock_list *entry, void *data)
+{
+	struct held_lock *hlock = (struct held_lock *)data;
+
+	return hlock_class(hlock) == entry->class && /* Found A -> .. -> B */
+	       (hlock->read == 0 || /* B -> A is -(E*)-> */
+		!entry->only_xr); /* A -> .. -> B is -(*N)-> */
 }
 
 static noinline void print_circular_bug(struct lock_list *this,
-					struct lock_list *target,
-					struct held_lock *check_src,
-					struct held_lock *check_tgt)
+				struct lock_list *target,
+				struct held_lock *check_src,
+				struct held_lock *check_tgt)
 {
 	struct task_struct *curr = current;
 	struct lock_list *parent;
@@ -1696,16 +2011,16 @@
 	WARN(1, "lockdep bfs error:%d\n", ret);
 }
 
-static int noop_count(struct lock_list *entry, void *data)
+static bool noop_count(struct lock_list *entry, void *data)
 {
 	(*(unsigned long *)data)++;
-	return 0;
+	return false;
 }
 
 static unsigned long __lockdep_count_forward_deps(struct lock_list *this)
 {
 	unsigned long  count = 0;
-	struct lock_list *uninitialized_var(target_entry);
+	struct lock_list *target_entry;
 
 	__bfs_forwards(this, (void *)&count, noop_count, &target_entry);
 
@@ -1716,15 +2031,12 @@
 	unsigned long ret, flags;
 	struct lock_list this;
 
-	this.parent = NULL;
-	this.class = class;
+	__bfs_init_root(&this, class);
 
 	raw_local_irq_save(flags);
-	current->lockdep_recursion = 1;
-	arch_spin_lock(&lockdep_lock);
+	lockdep_lock();
 	ret = __lockdep_count_forward_deps(&this);
-	arch_spin_unlock(&lockdep_lock);
-	current->lockdep_recursion = 0;
+	lockdep_unlock();
 	raw_local_irq_restore(flags);
 
 	return ret;
@@ -1733,7 +2045,7 @@
 static unsigned long __lockdep_count_backward_deps(struct lock_list *this)
 {
 	unsigned long  count = 0;
-	struct lock_list *uninitialized_var(target_entry);
+	struct lock_list *target_entry;
 
 	__bfs_backwards(this, (void *)&count, noop_count, &target_entry);
 
@@ -1745,15 +2057,12 @@
 	unsigned long ret, flags;
 	struct lock_list this;
 
-	this.parent = NULL;
-	this.class = class;
+	__bfs_init_root(&this, class);
 
 	raw_local_irq_save(flags);
-	current->lockdep_recursion = 1;
-	arch_spin_lock(&lockdep_lock);
+	lockdep_lock();
 	ret = __lockdep_count_backward_deps(&this);
-	arch_spin_unlock(&lockdep_lock);
-	current->lockdep_recursion = 0;
+	lockdep_unlock();
 	raw_local_irq_restore(flags);
 
 	return ret;
@@ -1761,18 +2070,18 @@
 
 /*
  * Check that the dependency graph starting at <src> can lead to
- * <target> or not. Print an error and return 0 if it does.
+ * <target> or not.
  */
-static noinline int
-check_path(struct lock_class *target, struct lock_list *src_entry,
+static noinline enum bfs_result
+check_path(struct held_lock *target, struct lock_list *src_entry,
+	   bool (*match)(struct lock_list *entry, void *data),
 	   struct lock_list **target_entry)
 {
-	int ret;
+	enum bfs_result ret;
 
-	ret = __bfs_forwards(src_entry, (void *)target, class_equal,
-			     target_entry);
+	ret = __bfs_forwards(src_entry, target, match, target_entry);
 
-	if (unlikely(ret < 0))
+	if (unlikely(bfs_error(ret)))
 		print_bfs_bug(ret);
 
 	return ret;
@@ -1783,24 +2092,23 @@
  * lead to <target>. If it can, there is a circle when adding
  * <target> -> <src> dependency.
  *
- * Print an error and return 0 if it does.
+ * Print an error and return BFS_RMATCH if it does.
  */
-static noinline int
+static noinline enum bfs_result
 check_noncircular(struct held_lock *src, struct held_lock *target,
 		  struct lock_trace **const trace)
 {
-	int ret;
-	struct lock_list *uninitialized_var(target_entry);
-	struct lock_list src_entry = {
-		.class = hlock_class(src),
-		.parent = NULL,
-	};
+	enum bfs_result ret;
+	struct lock_list *target_entry;
+	struct lock_list src_entry;
+
+	bfs_init_root(&src_entry, src);
 
 	debug_atomic_inc(nr_cyclic_checks);
 
-	ret = check_path(hlock_class(target), &src_entry, &target_entry);
+	ret = check_path(target, &src_entry, hlock_conflict, &target_entry);
 
-	if (unlikely(!ret)) {
+	if (unlikely(ret == BFS_RMATCH)) {
 		if (!*trace) {
 			/*
 			 * If save_trace fails here, the printing might
@@ -1822,27 +2130,35 @@
  * <target> or not. If it can, <src> -> <target> dependency is already
  * in the graph.
  *
- * Print an error and return 2 if it does or 1 if it does not.
+ * Return BFS_RMATCH if it does, or BFS_RMATCH if it does not, return BFS_E* if
+ * any error appears in the bfs search.
  */
-static noinline int
+static noinline enum bfs_result
 check_redundant(struct held_lock *src, struct held_lock *target)
 {
-	int ret;
-	struct lock_list *uninitialized_var(target_entry);
-	struct lock_list src_entry = {
-		.class = hlock_class(src),
-		.parent = NULL,
-	};
+	enum bfs_result ret;
+	struct lock_list *target_entry;
+	struct lock_list src_entry;
+
+	bfs_init_root(&src_entry, src);
+	/*
+	 * Special setup for check_redundant().
+	 *
+	 * To report redundant, we need to find a strong dependency path that
+	 * is equal to or stronger than <src> -> <target>. So if <src> is E,
+	 * we need to let __bfs() only search for a path starting at a -(E*)->,
+	 * we achieve this by setting the initial node's ->only_xr to true in
+	 * that case. And if <prev> is S, we set initial ->only_xr to false
+	 * because both -(S*)-> (equal) and -(E*)-> (stronger) are redundant.
+	 */
+	src_entry.only_xr = src->read == 0;
 
 	debug_atomic_inc(nr_redundant_checks);
 
-	ret = check_path(hlock_class(target), &src_entry, &target_entry);
+	ret = check_path(target, &src_entry, hlock_equal, &target_entry);
 
-	if (!ret) {
+	if (ret == BFS_RMATCH)
 		debug_atomic_inc(nr_redundant);
-		ret = 2;
-	} else if (ret < 0)
-		ret = 0;
 
 	return ret;
 }
@@ -1850,39 +2166,86 @@
 
 #ifdef CONFIG_TRACE_IRQFLAGS
 
-static inline int usage_accumulate(struct lock_list *entry, void *mask)
-{
-	*(unsigned long *)mask |= entry->class->usage_mask;
-
-	return 0;
-}
-
 /*
  * Forwards and backwards subgraph searching, for the purposes of
  * proving that two subgraphs can be connected by a new dependency
  * without creating any illegal irq-safe -> irq-unsafe lock dependency.
+ *
+ * A irq safe->unsafe deadlock happens with the following conditions:
+ *
+ * 1) We have a strong dependency path A -> ... -> B
+ *
+ * 2) and we have ENABLED_IRQ usage of B and USED_IN_IRQ usage of A, therefore
+ *    irq can create a new dependency B -> A (consider the case that a holder
+ *    of B gets interrupted by an irq whose handler will try to acquire A).
+ *
+ * 3) the dependency circle A -> ... -> B -> A we get from 1) and 2) is a
+ *    strong circle:
+ *
+ *      For the usage bits of B:
+ *        a) if A -> B is -(*N)->, then B -> A could be any type, so any
+ *           ENABLED_IRQ usage suffices.
+ *        b) if A -> B is -(*R)->, then B -> A must be -(E*)->, so only
+ *           ENABLED_IRQ_*_READ usage suffices.
+ *
+ *      For the usage bits of A:
+ *        c) if A -> B is -(E*)->, then B -> A could be any type, so any
+ *           USED_IN_IRQ usage suffices.
+ *        d) if A -> B is -(S*)->, then B -> A must be -(*N)->, so only
+ *           USED_IN_IRQ_*_READ usage suffices.
  */
 
-static inline int usage_match(struct lock_list *entry, void *mask)
+/*
+ * There is a strong dependency path in the dependency graph: A -> B, and now
+ * we need to decide which usage bit of A should be accumulated to detect
+ * safe->unsafe bugs.
+ *
+ * Note that usage_accumulate() is used in backwards search, so ->only_xr
+ * stands for whether A -> B only has -(S*)-> (in this case ->only_xr is true).
+ *
+ * As above, if only_xr is false, which means A -> B has -(E*)-> dependency
+ * path, any usage of A should be considered. Otherwise, we should only
+ * consider _READ usage.
+ */
+static inline bool usage_accumulate(struct lock_list *entry, void *mask)
 {
-	return entry->class->usage_mask & *(unsigned long *)mask;
+	if (!entry->only_xr)
+		*(unsigned long *)mask |= entry->class->usage_mask;
+	else /* Mask out _READ usage bits */
+		*(unsigned long *)mask |= (entry->class->usage_mask & LOCKF_IRQ);
+
+	return false;
+}
+
+/*
+ * There is a strong dependency path in the dependency graph: A -> B, and now
+ * we need to decide which usage bit of B conflicts with the usage bits of A,
+ * i.e. which usage bit of B may introduce safe->unsafe deadlocks.
+ *
+ * As above, if only_xr is false, which means A -> B has -(*N)-> dependency
+ * path, any usage of B should be considered. Otherwise, we should only
+ * consider _READ usage.
+ */
+static inline bool usage_match(struct lock_list *entry, void *mask)
+{
+	if (!entry->only_xr)
+		return !!(entry->class->usage_mask & *(unsigned long *)mask);
+	else /* Mask out _READ usage bits */
+		return !!((entry->class->usage_mask & LOCKF_IRQ) & *(unsigned long *)mask);
 }
 
 /*
  * Find a node in the forwards-direction dependency sub-graph starting
  * at @root->class that matches @bit.
  *
- * Return 0 if such a node exists in the subgraph, and put that node
+ * Return BFS_MATCH if such a node exists in the subgraph, and put that node
  * into *@target_entry.
- *
- * Return 1 otherwise and keep *@target_entry unchanged.
- * Return <0 on error.
  */
-static int
+static enum bfs_result
 find_usage_forwards(struct lock_list *root, unsigned long usage_mask,
 			struct lock_list **target_entry)
 {
-	int result;
+	enum bfs_result result;
 
 	debug_atomic_inc(nr_find_usage_forwards_checks);
 
@@ -1894,18 +2257,12 @@
 /*
  * Find a node in the backwards-direction dependency sub-graph starting
  * at @root->class that matches @bit.
- *
- * Return 0 if such a node exists in the subgraph, and put that node
- * into *@target_entry.
- *
- * Return 1 otherwise and keep *@target_entry unchanged.
- * Return <0 on error.
  */
-static int
+static enum bfs_result
 find_usage_backwards(struct lock_list *root, unsigned long usage_mask,
 			struct lock_list **target_entry)
 {
-	int result;
+	enum bfs_result result;
 
 	debug_atomic_inc(nr_find_usage_backwards_checks);
 
@@ -1925,7 +2282,7 @@
 #endif
 	printk(KERN_CONT " {\n");
 
-	for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
+	for (bit = 0; bit < LOCK_TRACE_STATES; bit++) {
 		if (class->usage_mask & (1 << bit)) {
 			int len = depth;
 
@@ -2152,9 +2509,9 @@
 	pr_warn("-----------------------------------------------------\n");
 	pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
 		curr->comm, task_pid_nr(curr),
-		curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
+		lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
 		curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
-		curr->hardirqs_enabled,
+		lockdep_hardirqs_enabled(),
 		curr->softirqs_enabled);
 	print_lock(next);
 
@@ -2269,17 +2626,39 @@
 }
 
 /*
- * As above, we clear bitnr0 (LOCK_*_READ off) with bitmask ops. First, for all
- * bits with bitnr0 set (LOCK_*_READ), add those with bitnr0 cleared (LOCK_*).
- * And then mask out all bitnr0.
+ * Note that a LOCK_ENABLED_IRQ_*_READ usage and a LOCK_USED_IN_IRQ_*_READ
+ * usage may cause deadlock too, for example:
+ *
+ * P1				P2
+ * <irq disabled>
+ * write_lock(l1);		<irq enabled>
+ *				read_lock(l2);
+ * write_lock(l2);
+ * 				<in irq>
+ * 				read_lock(l1);
+ *
+ * , in above case, l1 will be marked as LOCK_USED_IN_IRQ_HARDIRQ_READ and l2
+ * will marked as LOCK_ENABLE_IRQ_HARDIRQ_READ, and this is a possible
+ * deadlock.
+ *
+ * In fact, all of the following cases may cause deadlocks:
+ *
+ * 	 LOCK_USED_IN_IRQ_* -> LOCK_ENABLED_IRQ_*
+ * 	 LOCK_USED_IN_IRQ_*_READ -> LOCK_ENABLED_IRQ_*
+ * 	 LOCK_USED_IN_IRQ_* -> LOCK_ENABLED_IRQ_*_READ
+ * 	 LOCK_USED_IN_IRQ_*_READ -> LOCK_ENABLED_IRQ_*_READ
+ *
+ * As a result, to calculate the "exclusive mask", first we invert the
+ * direction (USED_IN/ENABLED) of the original mask, and 1) for all bits with
+ * bitnr0 set (LOCK_*_READ), add those with bitnr0 cleared (LOCK_*). 2) for all
+ * bits with bitnr0 cleared (LOCK_*_READ), add those with bitnr0 set (LOCK_*).
  */
 static unsigned long exclusive_mask(unsigned long mask)
 {
 	unsigned long excl = invert_dir_mask(mask);
 
-	/* Strip read */
 	excl |= (excl & LOCKF_IRQ_READ) >> LOCK_USAGE_READ_MASK;
-	excl &= ~LOCKF_IRQ_READ;
+	excl |= (excl & LOCKF_IRQ) << LOCK_USAGE_READ_MASK;
 
 	return excl;
 }
@@ -2296,6 +2675,7 @@
 	unsigned long excl = invert_dir_mask(mask);
 
 	/* Include read in existing usages */
+	excl |= (excl & LOCKF_IRQ_READ) >> LOCK_USAGE_READ_MASK;
 	excl |= (excl & LOCKF_IRQ) << LOCK_USAGE_READ_MASK;
 
 	return excl;
@@ -2310,14 +2690,24 @@
 				enum lock_usage_bit *bitp,
 				enum lock_usage_bit *excl_bitp)
 {
-	int bit, excl;
+	int bit, excl, excl_read;
 
 	for_each_set_bit(bit, &mask, LOCK_USED) {
+		/*
+		 * exclusive_bit() strips the read bit, however,
+		 * LOCK_ENABLED_IRQ_*_READ may cause deadlocks too, so we need
+		 * to search excl | LOCK_USAGE_READ_MASK as well.
+		 */
 		excl = exclusive_bit(bit);
+		excl_read = excl | LOCK_USAGE_READ_MASK;
 		if (excl_mask & lock_flag(excl)) {
 			*bitp = bit;
 			*excl_bitp = excl;
 			return 0;
+		} else if (excl_mask & lock_flag(excl_read)) {
+			*bitp = bit;
+			*excl_bitp = excl_read;
+			return 0;
 		}
 	}
 	return -1;
@@ -2334,20 +2724,19 @@
 {
 	unsigned long usage_mask = 0, forward_mask, backward_mask;
 	enum lock_usage_bit forward_bit = 0, backward_bit = 0;
-	struct lock_list *uninitialized_var(target_entry1);
-	struct lock_list *uninitialized_var(target_entry);
+	struct lock_list *target_entry1;
+	struct lock_list *target_entry;
 	struct lock_list this, that;
-	int ret;
+	enum bfs_result ret;
 
 	/*
 	 * Step 1: gather all hard/soft IRQs usages backward in an
 	 * accumulated usage mask.
 	 */
-	this.parent = NULL;
-	this.class = hlock_class(prev);
+	bfs_init_rootb(&this, prev);
 
 	ret = __bfs_backwards(&this, &usage_mask, usage_accumulate, NULL);
-	if (ret < 0) {
+	if (bfs_error(ret)) {
 		print_bfs_bug(ret);
 		return 0;
 	}
@@ -2362,16 +2751,15 @@
 	 */
 	forward_mask = exclusive_mask(usage_mask);
 
-	that.parent = NULL;
-	that.class = hlock_class(next);
+	bfs_init_root(&that, next);
 
 	ret = find_usage_forwards(&that, forward_mask, &target_entry1);
-	if (ret < 0) {
+	if (bfs_error(ret)) {
 		print_bfs_bug(ret);
 		return 0;
 	}
-	if (ret == 1)
-		return ret;
+	if (ret == BFS_RNOMATCH)
+		return 1;
 
 	/*
 	 * Step 3: we found a bad match! Now retrieve a lock from the backward
@@ -2391,11 +2779,11 @@
 	backward_mask = original_mask(target_entry1->class->usage_mask & LOCKF_ENABLED_IRQ_ALL);
 
 	ret = find_usage_backwards(&this, backward_mask, &target_entry);
-	if (ret < 0) {
+	if (bfs_error(ret)) {
 		print_bfs_bug(ret);
 		return 0;
 	}
-	if (DEBUG_LOCKS_WARN_ON(ret == 1))
+	if (DEBUG_LOCKS_WARN_ON(ret == BFS_RNOMATCH))
 		return 1;
 
 	/*
@@ -2497,7 +2885,9 @@
  * (Note that this has to be done separately, because the graph cannot
  * detect such classes of deadlocks.)
  *
- * Returns: 0 on deadlock detected, 1 on OK, 2 on recursive read
+ * Returns: 0 on deadlock detected, 1 on OK, 2 if another lock with the same
+ * lock class is held but nest_lock is also held, i.e. we rely on the
+ * nest_lock to avoid the deadlock.
  */
 static int
 check_deadlock(struct task_struct *curr, struct held_lock *next)
@@ -2520,7 +2910,7 @@
 		 * lock class (i.e. read_lock(lock)+read_lock(lock)):
 		 */
 		if ((next->read == 2) && prev->read)
-			return 2;
+			continue;
 
 		/*
 		 * We're holding the nest_lock, which serializes this lock's
@@ -2559,11 +2949,11 @@
  */
 static int
 check_prev_add(struct task_struct *curr, struct held_lock *prev,
-	       struct held_lock *next, int distance,
+	       struct held_lock *next, u16 distance,
 	       struct lock_trace **const trace)
 {
 	struct lock_list *entry;
-	int ret;
+	enum bfs_result ret;
 
 	if (!hlock_class(prev)->key || !hlock_class(next)->key) {
 		/*
@@ -2594,23 +2984,13 @@
 	 * in the graph whose neighbours are to be checked.
 	 */
 	ret = check_noncircular(next, prev, trace);
-	if (unlikely(ret <= 0))
+	if (unlikely(bfs_error(ret) || ret == BFS_RMATCH))
 		return 0;
 
 	if (!check_irq_usage(curr, prev, next))
 		return 0;
 
 	/*
-	 * For recursive read-locks we do all the dependency checks,
-	 * but we dont store read-triggered dependencies (only
-	 * write-triggered dependencies). This ensures that only the
-	 * write-side dependencies matter, and that if for example a
-	 * write-lock never takes any other locks, then the reads are
-	 * equivalent to a NOP.
-	 */
-	if (next->read == 2 || prev->read == 2)
-		return 1;
-	/*
 	 * Is the <prev> -> <next> dependency already present?
 	 *
 	 * (this may occur even though this is a new chain: consider
@@ -2622,7 +3002,35 @@
 		if (entry->class == hlock_class(next)) {
 			if (distance == 1)
 				entry->distance = 1;
-			return 1;
+			entry->dep |= calc_dep(prev, next);
+
+			/*
+			 * Also, update the reverse dependency in @next's
+			 * ->locks_before list.
+			 *
+			 *  Here we reuse @entry as the cursor, which is fine
+			 *  because we won't go to the next iteration of the
+			 *  outer loop:
+			 *
+			 *  For normal cases, we return in the inner loop.
+			 *
+			 *  If we fail to return, we have inconsistency, i.e.
+			 *  <prev>::locks_after contains <next> while
+			 *  <next>::locks_before doesn't contain <prev>. In
+			 *  that case, we return after the inner and indicate
+			 *  something is wrong.
+			 */
+			list_for_each_entry(entry, &hlock_class(next)->locks_before, entry) {
+				if (entry->class == hlock_class(prev)) {
+					if (distance == 1)
+						entry->distance = 1;
+					entry->dep |= calc_depb(prev, next);
+					return 1;
+				}
+			}
+
+			/* <prev> is not found in <next>::locks_before */
+			return 0;
 		}
 	}
 
@@ -2631,8 +3039,10 @@
 	 * Is the <prev> -> <next> link redundant?
 	 */
 	ret = check_redundant(prev, next);
-	if (ret != 1)
-		return ret;
+	if (bfs_error(ret))
+		return 0;
+	else if (ret == BFS_RMATCH)
+		return 2;
 #endif
 
 	if (!*trace) {
@@ -2647,14 +3057,18 @@
 	 */
 	ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
 			       &hlock_class(prev)->locks_after,
-			       next->acquire_ip, distance, *trace);
+			       next->acquire_ip, distance,
+			       calc_dep(prev, next),
+			       *trace);
 
 	if (!ret)
 		return 0;
 
 	ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
 			       &hlock_class(next)->locks_before,
-			       next->acquire_ip, distance, *trace);
+			       next->acquire_ip, distance,
+			       calc_depb(prev, next),
+			       *trace);
 	if (!ret)
 		return 0;
 
@@ -2690,16 +3104,11 @@
 		goto out_bug;
 
 	for (;;) {
-		int distance = curr->lockdep_depth - depth + 1;
+		u16 distance = curr->lockdep_depth - depth + 1;
 		hlock = curr->held_locks + depth - 1;
 
-		/*
-		 * Only non-recursive-read entries get new dependencies
-		 * added:
-		 */
-		if (hlock->read != 2 && hlock->check) {
-			int ret = check_prev_add(curr, hlock, next, distance,
-						 &trace);
+		if (hlock->check) {
+			int ret = check_prev_add(curr, hlock, next, distance, &trace);
 			if (!ret)
 				return 0;
 
@@ -2743,12 +3152,242 @@
 
 struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
 static DECLARE_BITMAP(lock_chains_in_use, MAX_LOCKDEP_CHAINS);
-int nr_chain_hlocks;
 static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+unsigned long nr_zapped_lock_chains;
+unsigned int nr_free_chain_hlocks;	/* Free chain_hlocks in buckets */
+unsigned int nr_lost_chain_hlocks;	/* Lost chain_hlocks */
+unsigned int nr_large_chain_blocks;	/* size > MAX_CHAIN_BUCKETS */
+
+/*
+ * The first 2 chain_hlocks entries in the chain block in the bucket
+ * list contains the following meta data:
+ *
+ *   entry[0]:
+ *     Bit    15 - always set to 1 (it is not a class index)
+ *     Bits 0-14 - upper 15 bits of the next block index
+ *   entry[1]    - lower 16 bits of next block index
+ *
+ * A next block index of all 1 bits means it is the end of the list.
+ *
+ * On the unsized bucket (bucket-0), the 3rd and 4th entries contain
+ * the chain block size:
+ *
+ *   entry[2] - upper 16 bits of the chain block size
+ *   entry[3] - lower 16 bits of the chain block size
+ */
+#define MAX_CHAIN_BUCKETS	16
+#define CHAIN_BLK_FLAG		(1U << 15)
+#define CHAIN_BLK_LIST_END	0xFFFFU
+
+static int chain_block_buckets[MAX_CHAIN_BUCKETS];
+
+static inline int size_to_bucket(int size)
+{
+	if (size > MAX_CHAIN_BUCKETS)
+		return 0;
+
+	return size - 1;
+}
+
+/*
+ * Iterate all the chain blocks in a bucket.
+ */
+#define for_each_chain_block(bucket, prev, curr)		\
+	for ((prev) = -1, (curr) = chain_block_buckets[bucket];	\
+	     (curr) >= 0;					\
+	     (prev) = (curr), (curr) = chain_block_next(curr))
+
+/*
+ * next block or -1
+ */
+static inline int chain_block_next(int offset)
+{
+	int next = chain_hlocks[offset];
+
+	WARN_ON_ONCE(!(next & CHAIN_BLK_FLAG));
+
+	if (next == CHAIN_BLK_LIST_END)
+		return -1;
+
+	next &= ~CHAIN_BLK_FLAG;
+	next <<= 16;
+	next |= chain_hlocks[offset + 1];
+
+	return next;
+}
+
+/*
+ * bucket-0 only
+ */
+static inline int chain_block_size(int offset)
+{
+	return (chain_hlocks[offset + 2] << 16) | chain_hlocks[offset + 3];
+}
+
+static inline void init_chain_block(int offset, int next, int bucket, int size)
+{
+	chain_hlocks[offset] = (next >> 16) | CHAIN_BLK_FLAG;
+	chain_hlocks[offset + 1] = (u16)next;
+
+	if (size && !bucket) {
+		chain_hlocks[offset + 2] = size >> 16;
+		chain_hlocks[offset + 3] = (u16)size;
+	}
+}
+
+static inline void add_chain_block(int offset, int size)
+{
+	int bucket = size_to_bucket(size);
+	int next = chain_block_buckets[bucket];
+	int prev, curr;
+
+	if (unlikely(size < 2)) {
+		/*
+		 * We can't store single entries on the freelist. Leak them.
+		 *
+		 * One possible way out would be to uniquely mark them, other
+		 * than with CHAIN_BLK_FLAG, such that we can recover them when
+		 * the block before it is re-added.
+		 */
+		if (size)
+			nr_lost_chain_hlocks++;
+		return;
+	}
+
+	nr_free_chain_hlocks += size;
+	if (!bucket) {
+		nr_large_chain_blocks++;
+
+		/*
+		 * Variable sized, sort large to small.
+		 */
+		for_each_chain_block(0, prev, curr) {
+			if (size >= chain_block_size(curr))
+				break;
+		}
+		init_chain_block(offset, curr, 0, size);
+		if (prev < 0)
+			chain_block_buckets[0] = offset;
+		else
+			init_chain_block(prev, offset, 0, 0);
+		return;
+	}
+	/*
+	 * Fixed size, add to head.
+	 */
+	init_chain_block(offset, next, bucket, size);
+	chain_block_buckets[bucket] = offset;
+}
+
+/*
+ * Only the first block in the list can be deleted.
+ *
+ * For the variable size bucket[0], the first block (the largest one) is
+ * returned, broken up and put back into the pool. So if a chain block of
+ * length > MAX_CHAIN_BUCKETS is ever used and zapped, it will just be
+ * queued up after the primordial chain block and never be used until the
+ * hlock entries in the primordial chain block is almost used up. That
+ * causes fragmentation and reduce allocation efficiency. That can be
+ * monitored by looking at the "large chain blocks" number in lockdep_stats.
+ */
+static inline void del_chain_block(int bucket, int size, int next)
+{
+	nr_free_chain_hlocks -= size;
+	chain_block_buckets[bucket] = next;
+
+	if (!bucket)
+		nr_large_chain_blocks--;
+}
+
+static void init_chain_block_buckets(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_CHAIN_BUCKETS; i++)
+		chain_block_buckets[i] = -1;
+
+	add_chain_block(0, ARRAY_SIZE(chain_hlocks));
+}
+
+/*
+ * Return offset of a chain block of the right size or -1 if not found.
+ *
+ * Fairly simple worst-fit allocator with the addition of a number of size
+ * specific free lists.
+ */
+static int alloc_chain_hlocks(int req)
+{
+	int bucket, curr, size;
+
+	/*
+	 * We rely on the MSB to act as an escape bit to denote freelist
+	 * pointers. Make sure this bit isn't set in 'normal' class_idx usage.
+	 */
+	BUILD_BUG_ON((MAX_LOCKDEP_KEYS-1) & CHAIN_BLK_FLAG);
+
+	init_data_structures_once();
+
+	if (nr_free_chain_hlocks < req)
+		return -1;
+
+	/*
+	 * We require a minimum of 2 (u16) entries to encode a freelist
+	 * 'pointer'.
+	 */
+	req = max(req, 2);
+	bucket = size_to_bucket(req);
+	curr = chain_block_buckets[bucket];
+
+	if (bucket) {
+		if (curr >= 0) {
+			del_chain_block(bucket, req, chain_block_next(curr));
+			return curr;
+		}
+		/* Try bucket 0 */
+		curr = chain_block_buckets[0];
+	}
+
+	/*
+	 * The variable sized freelist is sorted by size; the first entry is
+	 * the largest. Use it if it fits.
+	 */
+	if (curr >= 0) {
+		size = chain_block_size(curr);
+		if (likely(size >= req)) {
+			del_chain_block(0, size, chain_block_next(curr));
+			add_chain_block(curr + req, size - req);
+			return curr;
+		}
+	}
+
+	/*
+	 * Last resort, split a block in a larger sized bucket.
+	 */
+	for (size = MAX_CHAIN_BUCKETS; size > req; size--) {
+		bucket = size_to_bucket(size);
+		curr = chain_block_buckets[bucket];
+		if (curr < 0)
+			continue;
+
+		del_chain_block(bucket, size, chain_block_next(curr));
+		add_chain_block(curr + req, size - req);
+		return curr;
+	}
+
+	return -1;
+}
+
+static inline void free_chain_hlocks(int base, int size)
+{
+	add_chain_block(base, max(size, 2));
+}
 
 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
 {
-	return lock_classes + chain_hlocks[chain->base + i];
+	u16 chain_hlock = chain_hlocks[chain->base + i];
+	unsigned int class_idx = chain_hlock_class_idx(chain_hlock);
+
+	return lock_classes + class_idx;
 }
 
 /*
@@ -2774,12 +3413,12 @@
 /*
  * Returns the next chain_key iteration
  */
-static u64 print_chain_key_iteration(int class_idx, u64 chain_key)
+static u64 print_chain_key_iteration(u16 hlock_id, u64 chain_key)
 {
-	u64 new_chain_key = iterate_chain_key(chain_key, class_idx);
+	u64 new_chain_key = iterate_chain_key(chain_key, hlock_id);
 
-	printk(" class_idx:%d -> chain_key:%016Lx",
-		class_idx,
+	printk(" hlock_id:%d -> chain_key:%016Lx",
+		(unsigned int)hlock_id,
 		(unsigned long long)new_chain_key);
 	return new_chain_key;
 }
@@ -2796,12 +3435,12 @@
 		hlock_next->irq_context);
 	for (; i < depth; i++) {
 		hlock = curr->held_locks + i;
-		chain_key = print_chain_key_iteration(hlock->class_idx, chain_key);
+		chain_key = print_chain_key_iteration(hlock_id(hlock), chain_key);
 
 		print_lock(hlock);
 	}
 
-	print_chain_key_iteration(hlock_next->class_idx, chain_key);
+	print_chain_key_iteration(hlock_id(hlock_next), chain_key);
 	print_lock(hlock_next);
 }
 
@@ -2809,14 +3448,14 @@
 {
 	int i;
 	u64 chain_key = INITIAL_CHAIN_KEY;
-	int class_id;
+	u16 hlock_id;
 
 	printk("depth: %u\n", chain->depth);
 	for (i = 0; i < chain->depth; i++) {
-		class_id = chain_hlocks[chain->base + i];
-		chain_key = print_chain_key_iteration(class_id, chain_key);
+		hlock_id = chain_hlocks[chain->base + i];
+		chain_key = print_chain_key_iteration(hlock_id, chain_key);
 
-		print_lock_name(lock_classes + class_id);
+		print_lock_name(lock_classes + chain_hlock_class_idx(hlock_id));
 		printk("\n");
 	}
 }
@@ -2865,7 +3504,7 @@
 	}
 
 	for (j = 0; j < chain->depth - 1; j++, i++) {
-		id = curr->held_locks[i].class_idx;
+		id = hlock_id(&curr->held_locks[i]);
 
 		if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) {
 			print_collision(curr, hlock, chain);
@@ -2914,7 +3553,6 @@
 				  struct held_lock *hlock,
 				  u64 chain_key)
 {
-	struct lock_class *class = hlock_class(hlock);
 	struct hlist_head *hash_head = chainhashentry(chain_key);
 	struct lock_chain *chain;
 	int i, j;
@@ -2924,7 +3562,7 @@
 	 * disabled to make this an IRQ-safe lock.. for recursion reasons
 	 * lockdep won't complain about its own locking errors.
 	 */
-	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
+	if (lockdep_assert_locked())
 		return 0;
 
 	chain = alloc_lock_chain();
@@ -2945,15 +3583,8 @@
 	BUILD_BUG_ON((1UL << 6)  <= ARRAY_SIZE(curr->held_locks));
 	BUILD_BUG_ON((1UL << 8*sizeof(chain_hlocks[0])) <= ARRAY_SIZE(lock_classes));
 
-	if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
-		chain->base = nr_chain_hlocks;
-		for (j = 0; j < chain->depth - 1; j++, i++) {
-			int lock_id = curr->held_locks[i].class_idx;
-			chain_hlocks[chain->base + j] = lock_id;
-		}
-		chain_hlocks[chain->base + j] = class - lock_classes;
-		nr_chain_hlocks += chain->depth;
-	} else {
+	j = alloc_chain_hlocks(chain->depth);
+	if (j < 0) {
 		if (!debug_locks_off_graph_unlock())
 			return 0;
 
@@ -2962,6 +3593,13 @@
 		return 0;
 	}
 
+	chain->base = j;
+	for (j = 0; j < chain->depth - 1; j++, i++) {
+		int lock_id = hlock_id(curr->held_locks + i);
+
+		chain_hlocks[chain->base + j] = lock_id;
+	}
+	chain_hlocks[chain->base + j] = hlock_id(hlock);
 	hlist_add_head_rcu(&chain->entry, hash_head);
 	debug_atomic_inc(chain_lookup_misses);
 	inc_chains(chain->irq_context);
@@ -3077,15 +3715,12 @@
 		if (!ret)
 			return 0;
 		/*
-		 * Mark recursive read, as we jump over it when
-		 * building dependencies (just like we jump over
-		 * trylock entries):
-		 */
-		if (ret == 2)
-			hlock->read = 2;
-		/*
 		 * Add dependency only if this lock is not the head
-		 * of the chain, and if it's not a secondary read-lock:
+		 * of the chain, and if the new lock introduces no more
+		 * lock dependency (because we already hold a lock with the
+		 * same lock class) nor deadlock (because the nest_lock
+		 * serializes nesting locks), see the comments for
+		 * check_deadlock().
 		 */
 		if (!chain_head && ret != 2) {
 			if (!check_prevs_add(curr, hlock))
@@ -3108,6 +3743,8 @@
 {
 	return 1;
 }
+
+static void init_chain_block_buckets(void)	{ }
 #endif /* CONFIG_PROVE_LOCKING */
 
 /*
@@ -3146,7 +3783,7 @@
 		if (prev_hlock && (prev_hlock->irq_context !=
 							hlock->irq_context))
 			chain_key = INITIAL_CHAIN_KEY;
-		chain_key = iterate_chain_key(chain_key, hlock->class_idx);
+		chain_key = iterate_chain_key(chain_key, hlock_id(hlock));
 		prev_hlock = hlock;
 	}
 	if (chain_key != curr->curr_chain_key) {
@@ -3188,7 +3825,7 @@
 print_usage_bug(struct task_struct *curr, struct held_lock *this,
 		enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
 {
-	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
+	if (!debug_locks_off() || debug_locks_silent)
 		return;
 
 	pr_warn("\n");
@@ -3202,10 +3839,10 @@
 
 	pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
 		curr->comm, task_pid_nr(curr),
-		trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
-		trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
-		trace_hardirqs_enabled(curr),
-		trace_softirqs_enabled(curr));
+		lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
+		lockdep_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
+		lockdep_hardirqs_enabled(),
+		lockdep_softirqs_enabled(curr));
 	print_lock(this);
 
 	pr_warn("{%s} state was registered at:\n", usage_str[prev_bit]);
@@ -3229,6 +3866,7 @@
 	    enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
 {
 	if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit))) {
+		graph_unlock();
 		print_usage_bug(curr, this, bad_bit, new_bit);
 		return 0;
 	}
@@ -3305,24 +3943,32 @@
  */
 static int
 check_usage_forwards(struct task_struct *curr, struct held_lock *this,
-		     enum lock_usage_bit bit, const char *irqclass)
+		     enum lock_usage_bit bit)
 {
-	int ret;
+	enum bfs_result ret;
 	struct lock_list root;
-	struct lock_list *uninitialized_var(target_entry);
+	struct lock_list *target_entry;
+	enum lock_usage_bit read_bit = bit + LOCK_USAGE_READ_MASK;
+	unsigned usage_mask = lock_flag(bit) | lock_flag(read_bit);
 
-	root.parent = NULL;
-	root.class = hlock_class(this);
-	ret = find_usage_forwards(&root, lock_flag(bit), &target_entry);
-	if (ret < 0) {
+	bfs_init_root(&root, this);
+	ret = find_usage_forwards(&root, usage_mask, &target_entry);
+	if (bfs_error(ret)) {
 		print_bfs_bug(ret);
 		return 0;
 	}
-	if (ret == 1)
-		return ret;
+	if (ret == BFS_RNOMATCH)
+		return 1;
 
-	print_irq_inversion_bug(curr, &root, target_entry,
-				this, 1, irqclass);
+	/* Check whether write or read usage is the match */
+	if (target_entry->class->usage_mask & lock_flag(bit)) {
+		print_irq_inversion_bug(curr, &root, target_entry,
+					this, 1, state_name(bit));
+	} else {
+		print_irq_inversion_bug(curr, &root, target_entry,
+					this, 1, state_name(read_bit));
+	}
+
 	return 0;
 }
 
@@ -3332,42 +3978,52 @@
  */
 static int
 check_usage_backwards(struct task_struct *curr, struct held_lock *this,
-		      enum lock_usage_bit bit, const char *irqclass)
+		      enum lock_usage_bit bit)
 {
-	int ret;
+	enum bfs_result ret;
 	struct lock_list root;
-	struct lock_list *uninitialized_var(target_entry);
+	struct lock_list *target_entry;
+	enum lock_usage_bit read_bit = bit + LOCK_USAGE_READ_MASK;
+	unsigned usage_mask = lock_flag(bit) | lock_flag(read_bit);
 
-	root.parent = NULL;
-	root.class = hlock_class(this);
-	ret = find_usage_backwards(&root, lock_flag(bit), &target_entry);
-	if (ret < 0) {
+	bfs_init_rootb(&root, this);
+	ret = find_usage_backwards(&root, usage_mask, &target_entry);
+	if (bfs_error(ret)) {
 		print_bfs_bug(ret);
 		return 0;
 	}
-	if (ret == 1)
-		return ret;
+	if (ret == BFS_RNOMATCH)
+		return 1;
 
-	print_irq_inversion_bug(curr, &root, target_entry,
-				this, 0, irqclass);
+	/* Check whether write or read usage is the match */
+	if (target_entry->class->usage_mask & lock_flag(bit)) {
+		print_irq_inversion_bug(curr, &root, target_entry,
+					this, 0, state_name(bit));
+	} else {
+		print_irq_inversion_bug(curr, &root, target_entry,
+					this, 0, state_name(read_bit));
+	}
+
 	return 0;
 }
 
 void print_irqtrace_events(struct task_struct *curr)
 {
-	printk("irq event stamp: %u\n", curr->irq_events);
+	const struct irqtrace_events *trace = &curr->irqtrace;
+
+	printk("irq event stamp: %u\n", trace->irq_events);
 	printk("hardirqs last  enabled at (%u): [<%px>] %pS\n",
-		curr->hardirq_enable_event, (void *)curr->hardirq_enable_ip,
-		(void *)curr->hardirq_enable_ip);
+		trace->hardirq_enable_event, (void *)trace->hardirq_enable_ip,
+		(void *)trace->hardirq_enable_ip);
 	printk("hardirqs last disabled at (%u): [<%px>] %pS\n",
-		curr->hardirq_disable_event, (void *)curr->hardirq_disable_ip,
-		(void *)curr->hardirq_disable_ip);
+		trace->hardirq_disable_event, (void *)trace->hardirq_disable_ip,
+		(void *)trace->hardirq_disable_ip);
 	printk("softirqs last  enabled at (%u): [<%px>] %pS\n",
-		curr->softirq_enable_event, (void *)curr->softirq_enable_ip,
-		(void *)curr->softirq_enable_ip);
+		trace->softirq_enable_event, (void *)trace->softirq_enable_ip,
+		(void *)trace->softirq_enable_ip);
 	printk("softirqs last disabled at (%u): [<%px>] %pS\n",
-		curr->softirq_disable_event, (void *)curr->softirq_disable_ip,
-		(void *)curr->softirq_disable_ip);
+		trace->softirq_disable_event, (void *)trace->softirq_disable_ip,
+		(void *)trace->softirq_disable_ip);
 }
 
 static int HARDIRQ_verbose(struct lock_class *class)
@@ -3386,8 +4042,6 @@
 	return 0;
 }
 
-#define STRICT_READ_CHECKS	1
-
 static int (*state_verbose_f[])(struct lock_class *class) = {
 #define LOCKDEP_STATE(__STATE) \
 	__STATE##_verbose,
@@ -3413,16 +4067,6 @@
 	int dir = new_bit & LOCK_USAGE_DIR_MASK;
 
 	/*
-	 * mark USED_IN has to look forwards -- to ensure no dependency
-	 * has ENABLED state, which would allow recursion deadlocks.
-	 *
-	 * mark ENABLED has to look backwards -- to ensure no dependee
-	 * has USED_IN state, which, again, would allow  recursion deadlocks.
-	 */
-	check_usage_f usage = dir ?
-		check_usage_backwards : check_usage_forwards;
-
-	/*
 	 * Validate that this particular lock does not have conflicting
 	 * usage states.
 	 */
@@ -3430,23 +4074,30 @@
 		return 0;
 
 	/*
+	 * Check for read in write conflicts
+	 */
+	if (!read && !valid_state(curr, this, new_bit,
+				  excl_bit + LOCK_USAGE_READ_MASK))
+		return 0;
+
+
+	/*
 	 * Validate that the lock dependencies don't have conflicting usage
 	 * states.
 	 */
-	if ((!read || STRICT_READ_CHECKS) &&
-			!usage(curr, this, excl_bit, state_name(new_bit & ~LOCK_USAGE_READ_MASK)))
-		return 0;
-
-	/*
-	 * Check for read in write conflicts
-	 */
-	if (!read) {
-		if (!valid_state(curr, this, new_bit, excl_bit + LOCK_USAGE_READ_MASK))
+	if (dir) {
+		/*
+		 * mark ENABLED has to look backwards -- to ensure no dependee
+		 * has USED_IN state, which, again, would allow  recursion deadlocks.
+		 */
+		if (!check_usage_backwards(curr, this, excl_bit))
 			return 0;
-
-		if (STRICT_READ_CHECKS &&
-			!usage(curr, this, excl_bit + LOCK_USAGE_READ_MASK,
-				state_name(new_bit + LOCK_USAGE_READ_MASK)))
+	} else {
+		/*
+		 * mark USED_IN has to look forwards -- to ensure no dependency
+		 * has ENABLED state, which would allow recursion deadlocks.
+		 */
+		if (!check_usage_forwards(curr, this, excl_bit))
 			return 0;
 	}
 
@@ -3487,13 +4138,10 @@
 /*
  * Hardirqs will be enabled:
  */
-static void __trace_hardirqs_on_caller(unsigned long ip)
+static void __trace_hardirqs_on_caller(void)
 {
 	struct task_struct *curr = current;
 
-	/* we'll do an OFF -> ON transition: */
-	curr->hardirqs_enabled = 1;
-
 	/*
 	 * We are going to turn hardirqs on, so set the
 	 * usage bit for all held locks:
@@ -3506,20 +4154,33 @@
 	 * this bit from being set before)
 	 */
 	if (curr->softirqs_enabled)
-		if (!mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ))
-			return;
-
-	curr->hardirq_enable_ip = ip;
-	curr->hardirq_enable_event = ++curr->irq_events;
-	debug_atomic_inc(hardirqs_on_events);
+		mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ);
 }
 
-void lockdep_hardirqs_on(unsigned long ip)
+/**
+ * lockdep_hardirqs_on_prepare - Prepare for enabling interrupts
+ * @ip:		Caller address
+ *
+ * Invoked before a possible transition to RCU idle from exit to user or
+ * guest mode. This ensures that all RCU operations are done before RCU
+ * stops watching. After the RCU transition lockdep_hardirqs_on() has to be
+ * invoked to set the final state.
+ */
+void lockdep_hardirqs_on_prepare(unsigned long ip)
 {
-	if (unlikely(!debug_locks || current->lockdep_recursion))
+	if (unlikely(!debug_locks))
 		return;
 
-	if (unlikely(current->hardirqs_enabled)) {
+	/*
+	 * NMIs do not (and cannot) track lock dependencies, nothing to do.
+	 */
+	if (unlikely(in_nmi()))
+		return;
+
+	if (unlikely(this_cpu_read(lockdep_recursion)))
+		return;
+
+	if (unlikely(lockdep_hardirqs_enabled())) {
 		/*
 		 * Neither irq nor preemption are disabled here
 		 * so this is racy by nature but losing one hit
@@ -3547,23 +4208,98 @@
 	 * Can't allow enabling interrupts while in an interrupt handler,
 	 * that's general bad form and such. Recursion, limited stack etc..
 	 */
-	if (DEBUG_LOCKS_WARN_ON(current->hardirq_context))
+	if (DEBUG_LOCKS_WARN_ON(lockdep_hardirq_context()))
 		return;
 
-	current->lockdep_recursion = 1;
-	__trace_hardirqs_on_caller(ip);
-	current->lockdep_recursion = 0;
+	current->hardirq_chain_key = current->curr_chain_key;
+
+	lockdep_recursion_inc();
+	__trace_hardirqs_on_caller();
+	lockdep_recursion_finish();
 }
-NOKPROBE_SYMBOL(lockdep_hardirqs_on);
+EXPORT_SYMBOL_GPL(lockdep_hardirqs_on_prepare);
+
+void noinstr lockdep_hardirqs_on(unsigned long ip)
+{
+	struct irqtrace_events *trace = &current->irqtrace;
+
+	if (unlikely(!debug_locks))
+		return;
+
+	/*
+	 * NMIs can happen in the middle of local_irq_{en,dis}able() where the
+	 * tracking state and hardware state are out of sync.
+	 *
+	 * NMIs must save lockdep_hardirqs_enabled() to restore IRQ state from,
+	 * and not rely on hardware state like normal interrupts.
+	 */
+	if (unlikely(in_nmi())) {
+		if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
+			return;
+
+		/*
+		 * Skip:
+		 *  - recursion check, because NMI can hit lockdep;
+		 *  - hardware state check, because above;
+		 *  - chain_key check, see lockdep_hardirqs_on_prepare().
+		 */
+		goto skip_checks;
+	}
+
+	if (unlikely(this_cpu_read(lockdep_recursion)))
+		return;
+
+	if (lockdep_hardirqs_enabled()) {
+		/*
+		 * Neither irq nor preemption are disabled here
+		 * so this is racy by nature but losing one hit
+		 * in a stat is not a big deal.
+		 */
+		__debug_atomic_inc(redundant_hardirqs_on);
+		return;
+	}
+
+	/*
+	 * We're enabling irqs and according to our state above irqs weren't
+	 * already enabled, yet we find the hardware thinks they are in fact
+	 * enabled.. someone messed up their IRQ state tracing.
+	 */
+	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
+		return;
+
+	/*
+	 * Ensure the lock stack remained unchanged between
+	 * lockdep_hardirqs_on_prepare() and lockdep_hardirqs_on().
+	 */
+	DEBUG_LOCKS_WARN_ON(current->hardirq_chain_key !=
+			    current->curr_chain_key);
+
+skip_checks:
+	/* we'll do an OFF -> ON transition: */
+	__this_cpu_write(hardirqs_enabled, 1);
+	trace->hardirq_enable_ip = ip;
+	trace->hardirq_enable_event = ++trace->irq_events;
+	debug_atomic_inc(hardirqs_on_events);
+}
+EXPORT_SYMBOL_GPL(lockdep_hardirqs_on);
 
 /*
  * Hardirqs were disabled:
  */
-void lockdep_hardirqs_off(unsigned long ip)
+void noinstr lockdep_hardirqs_off(unsigned long ip)
 {
-	struct task_struct *curr = current;
+	if (unlikely(!debug_locks))
+		return;
 
-	if (unlikely(!debug_locks || current->lockdep_recursion))
+	/*
+	 * Matching lockdep_hardirqs_on(), allow NMIs in the middle of lockdep;
+	 * they will restore the software state. This ensures the software
+	 * state is consistent inside NMIs as well.
+	 */
+	if (in_nmi()) {
+		if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
+			return;
+	} else if (__this_cpu_read(lockdep_recursion))
 		return;
 
 	/*
@@ -3573,27 +4309,30 @@
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
 		return;
 
-	if (curr->hardirqs_enabled) {
+	if (lockdep_hardirqs_enabled()) {
+		struct irqtrace_events *trace = &current->irqtrace;
+
 		/*
 		 * We have done an ON -> OFF transition:
 		 */
-		curr->hardirqs_enabled = 0;
-		curr->hardirq_disable_ip = ip;
-		curr->hardirq_disable_event = ++curr->irq_events;
+		__this_cpu_write(hardirqs_enabled, 0);
+		trace->hardirq_disable_ip = ip;
+		trace->hardirq_disable_event = ++trace->irq_events;
 		debug_atomic_inc(hardirqs_off_events);
-	} else
+	} else {
 		debug_atomic_inc(redundant_hardirqs_off);
+	}
 }
-NOKPROBE_SYMBOL(lockdep_hardirqs_off);
+EXPORT_SYMBOL_GPL(lockdep_hardirqs_off);
 
 /*
  * Softirqs will be enabled:
  */
-void trace_softirqs_on(unsigned long ip)
+void lockdep_softirqs_on(unsigned long ip)
 {
-	struct task_struct *curr = current;
+	struct irqtrace_events *trace = &current->irqtrace;
 
-	if (unlikely(!debug_locks || current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return;
 
 	/*
@@ -3603,37 +4342,35 @@
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
 		return;
 
-	if (curr->softirqs_enabled) {
+	if (current->softirqs_enabled) {
 		debug_atomic_inc(redundant_softirqs_on);
 		return;
 	}
 
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	/*
 	 * We'll do an OFF -> ON transition:
 	 */
-	curr->softirqs_enabled = 1;
-	curr->softirq_enable_ip = ip;
-	curr->softirq_enable_event = ++curr->irq_events;
+	current->softirqs_enabled = 1;
+	trace->softirq_enable_ip = ip;
+	trace->softirq_enable_event = ++trace->irq_events;
 	debug_atomic_inc(softirqs_on_events);
 	/*
 	 * We are going to turn softirqs on, so set the
 	 * usage bit for all held locks, if hardirqs are
 	 * enabled too:
 	 */
-	if (curr->hardirqs_enabled)
-		mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ);
-	current->lockdep_recursion = 0;
+	if (lockdep_hardirqs_enabled())
+		mark_held_locks(current, LOCK_ENABLED_SOFTIRQ);
+	lockdep_recursion_finish();
 }
 
 /*
  * Softirqs were disabled:
  */
-void trace_softirqs_off(unsigned long ip)
+void lockdep_softirqs_off(unsigned long ip)
 {
-	struct task_struct *curr = current;
-
-	if (unlikely(!debug_locks || current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return;
 
 	/*
@@ -3642,13 +4379,15 @@
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
 		return;
 
-	if (curr->softirqs_enabled) {
+	if (current->softirqs_enabled) {
+		struct irqtrace_events *trace = &current->irqtrace;
+
 		/*
 		 * We have done an ON -> OFF transition:
 		 */
-		curr->softirqs_enabled = 0;
-		curr->softirq_disable_ip = ip;
-		curr->softirq_disable_event = ++curr->irq_events;
+		current->softirqs_enabled = 0;
+		trace->softirq_disable_ip = ip;
+		trace->softirq_disable_event = ++trace->irq_events;
 		debug_atomic_inc(softirqs_off_events);
 		/*
 		 * Whoops, we wanted softirqs off, so why aren't they?
@@ -3670,7 +4409,7 @@
 	 */
 	if (!hlock->trylock) {
 		if (hlock->read) {
-			if (curr->hardirq_context)
+			if (lockdep_hardirq_context())
 				if (!mark_lock(curr, hlock,
 						LOCK_USED_IN_HARDIRQ_READ))
 					return 0;
@@ -3679,7 +4418,7 @@
 						LOCK_USED_IN_SOFTIRQ_READ))
 					return 0;
 		} else {
-			if (curr->hardirq_context)
+			if (lockdep_hardirq_context())
 				if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ))
 					return 0;
 			if (curr->softirq_context)
@@ -3717,7 +4456,7 @@
 
 static inline unsigned int task_irq_context(struct task_struct *task)
 {
-	return LOCK_CHAIN_HARDIRQ_CONTEXT * !!task->hardirq_context +
+	return LOCK_CHAIN_HARDIRQ_CONTEXT * !!lockdep_hardirq_context() +
 	       LOCK_CHAIN_SOFTIRQ_CONTEXT * !!task->softirq_context;
 }
 
@@ -3750,13 +4489,18 @@
 static int mark_lock(struct task_struct *curr, struct held_lock *this,
 			     enum lock_usage_bit new_bit)
 {
-	unsigned int new_mask = 1 << new_bit, ret = 1;
+	unsigned int new_mask, ret = 1;
 
 	if (new_bit >= LOCK_USAGE_STATES) {
 		DEBUG_LOCKS_WARN_ON(1);
 		return 0;
 	}
 
+	if (new_bit == LOCK_USED && this->read)
+		new_bit = LOCK_USED_READ;
+
+	new_mask = 1 << new_bit;
+
 	/*
 	 * If already set then do not dirty the cacheline,
 	 * nor do any checks:
@@ -3769,26 +4513,26 @@
 	/*
 	 * Make sure we didn't race:
 	 */
-	if (unlikely(hlock_class(this)->usage_mask & new_mask)) {
-		graph_unlock();
-		return 1;
-	}
+	if (unlikely(hlock_class(this)->usage_mask & new_mask))
+		goto unlock;
+
+	if (!hlock_class(this)->usage_mask)
+		debug_atomic_dec(nr_unused_locks);
 
 	hlock_class(this)->usage_mask |= new_mask;
 
-	if (!(hlock_class(this)->usage_traces[new_bit] = save_trace()))
-		return 0;
+	if (new_bit < LOCK_TRACE_STATES) {
+		if (!(hlock_class(this)->usage_traces[new_bit] = save_trace()))
+			return 0;
+	}
 
-	switch (new_bit) {
-	case LOCK_USED:
-		debug_atomic_dec(nr_unused_locks);
-		break;
-	default:
+	if (new_bit < LOCK_USED) {
 		ret = mark_lock_irq(curr, this, new_bit);
 		if (!ret)
 			return 0;
 	}
 
+unlock:
 	graph_unlock();
 
 	/*
@@ -3804,6 +4548,124 @@
 	return ret;
 }
 
+static inline short task_wait_context(struct task_struct *curr)
+{
+	/*
+	 * Set appropriate wait type for the context; for IRQs we have to take
+	 * into account force_irqthread as that is implied by PREEMPT_RT.
+	 */
+	if (lockdep_hardirq_context()) {
+		/*
+		 * Check if force_irqthreads will run us threaded.
+		 */
+		if (curr->hardirq_threaded || curr->irq_config)
+			return LD_WAIT_CONFIG;
+
+		return LD_WAIT_SPIN;
+	} else if (curr->softirq_context) {
+		/*
+		 * Softirqs are always threaded.
+		 */
+		return LD_WAIT_CONFIG;
+	}
+
+	return LD_WAIT_MAX;
+}
+
+static int
+print_lock_invalid_wait_context(struct task_struct *curr,
+				struct held_lock *hlock)
+{
+	short curr_inner;
+
+	if (!debug_locks_off())
+		return 0;
+	if (debug_locks_silent)
+		return 0;
+
+	pr_warn("\n");
+	pr_warn("=============================\n");
+	pr_warn("[ BUG: Invalid wait context ]\n");
+	print_kernel_ident();
+	pr_warn("-----------------------------\n");
+
+	pr_warn("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));
+	print_lock(hlock);
+
+	pr_warn("other info that might help us debug this:\n");
+
+	curr_inner = task_wait_context(curr);
+	pr_warn("context-{%d:%d}\n", curr_inner, curr_inner);
+
+	lockdep_print_held_locks(curr);
+
+	pr_warn("stack backtrace:\n");
+	dump_stack();
+
+	return 0;
+}
+
+/*
+ * Verify the wait_type context.
+ *
+ * This check validates we takes locks in the right wait-type order; that is it
+ * ensures that we do not take mutexes inside spinlocks and do not attempt to
+ * acquire spinlocks inside raw_spinlocks and the sort.
+ *
+ * The entire thing is slightly more complex because of RCU, RCU is a lock that
+ * can be taken from (pretty much) any context but also has constraints.
+ * However when taken in a stricter environment the RCU lock does not loosen
+ * the constraints.
+ *
+ * Therefore we must look for the strictest environment in the lock stack and
+ * compare that to the lock we're trying to acquire.
+ */
+static int check_wait_context(struct task_struct *curr, struct held_lock *next)
+{
+	u8 next_inner = hlock_class(next)->wait_type_inner;
+	u8 next_outer = hlock_class(next)->wait_type_outer;
+	u8 curr_inner;
+	int depth;
+
+	if (!next_inner || next->trylock)
+		return 0;
+
+	if (!next_outer)
+		next_outer = next_inner;
+
+	/*
+	 * Find start of current irq_context..
+	 */
+	for (depth = curr->lockdep_depth - 1; depth >= 0; depth--) {
+		struct held_lock *prev = curr->held_locks + depth;
+		if (prev->irq_context != next->irq_context)
+			break;
+	}
+	depth++;
+
+	curr_inner = task_wait_context(curr);
+
+	for (; depth < curr->lockdep_depth; depth++) {
+		struct held_lock *prev = curr->held_locks + depth;
+		u8 prev_inner = hlock_class(prev)->wait_type_inner;
+
+		if (prev_inner) {
+			/*
+			 * We can have a bigger inner than a previous one
+			 * when outer is smaller than inner, as with RCU.
+			 *
+			 * Also due to trylocks.
+			 */
+			curr_inner = min(curr_inner, prev_inner);
+		}
+	}
+
+	if (next_outer > curr_inner)
+		return print_lock_invalid_wait_context(curr, next);
+
+	return 0;
+}
+
 #else /* CONFIG_PROVE_LOCKING */
 
 static inline int
@@ -3823,13 +4685,20 @@
 	return 0;
 }
 
+static inline int check_wait_context(struct task_struct *curr,
+				     struct held_lock *next)
+{
+	return 0;
+}
+
 #endif /* CONFIG_PROVE_LOCKING */
 
 /*
  * Initialize a lock instance's lock-class mapping info:
  */
-void lockdep_init_map(struct lockdep_map *lock, const char *name,
-		      struct lock_class_key *key, int subclass)
+void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
+			    struct lock_class_key *key, int subclass,
+			    u8 inner, u8 outer, u8 lock_type)
 {
 	int i;
 
@@ -3850,6 +4719,10 @@
 
 	lock->name = name;
 
+	lock->wait_type_outer = outer;
+	lock->wait_type_inner = inner;
+	lock->lock_type = lock_type;
+
 	/*
 	 * No key, no joy, we need to hash something.
 	 */
@@ -3873,17 +4746,17 @@
 	if (subclass) {
 		unsigned long flags;
 
-		if (DEBUG_LOCKS_WARN_ON(current->lockdep_recursion))
+		if (DEBUG_LOCKS_WARN_ON(!lockdep_enabled()))
 			return;
 
 		raw_local_irq_save(flags);
-		current->lockdep_recursion = 1;
+		lockdep_recursion_inc();
 		register_lock_class(lock, subclass, 1);
-		current->lockdep_recursion = 0;
+		lockdep_recursion_finish();
 		raw_local_irq_restore(flags);
 	}
 }
-EXPORT_SYMBOL_GPL(lockdep_init_map);
+EXPORT_SYMBOL_GPL(lockdep_init_map_type);
 
 struct lock_class_key __lockdep_no_validate__;
 EXPORT_SYMBOL_GPL(__lockdep_no_validate__);
@@ -3984,7 +4857,7 @@
 
 	class_idx = class - lock_classes;
 
-	if (depth) {
+	if (depth) { /* we're holding locks */
 		hlock = curr->held_locks + depth - 1;
 		if (hlock->class_idx == class_idx && nest_lock) {
 			if (!references)
@@ -4026,6 +4899,9 @@
 #endif
 	hlock->pin_count = pin_count;
 
+	if (check_wait_context(curr, hlock))
+		return 0;
+
 	/* Initialize the lock usage bit */
 	if (!mark_usage(curr, hlock, check))
 		return 0;
@@ -4061,7 +4937,7 @@
 		chain_key = INITIAL_CHAIN_KEY;
 		chain_head = 1;
 	}
-	chain_key = iterate_chain_key(chain_key, class_idx);
+	chain_key = iterate_chain_key(chain_key, hlock_id(hlock));
 
 	if (nest_lock && !__lock_is_held(nest_lock, -1)) {
 		print_lock_nested_lock_not_held(curr, hlock, ip);
@@ -4120,7 +4996,7 @@
 		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
 	pr_cont(") at:\n");
-	print_ip_sym(ip);
+	print_ip_sym(KERN_WARNING, ip);
 	pr_warn("but there are no more locks to release!\n");
 	pr_warn("\nother info that might help us debug this:\n");
 	lockdep_print_held_locks(curr);
@@ -4129,8 +5005,8 @@
 	dump_stack();
 }
 
-static int match_held_lock(const struct held_lock *hlock,
-					const struct lockdep_map *lock)
+static noinstr int match_held_lock(const struct held_lock *hlock,
+				   const struct lockdep_map *lock)
 {
 	if (hlock->instance == lock)
 		return 1;
@@ -4261,7 +5137,9 @@
 		return 0;
 	}
 
-	lockdep_init_map(lock, name, key, 0);
+	lockdep_init_map_waits(lock, name, key, 0,
+			       lock->wait_type_inner,
+			       lock->wait_type_outer);
 	class = register_lock_class(lock, subclass, 0);
 	hlock->class_idx = class - lock_classes;
 
@@ -4329,11 +5207,9 @@
 }
 
 /*
- * Remove the lock to the list of currently held locks - this gets
+ * Remove the lock from the list of currently held locks - this gets
  * called on mutex_unlock()/spin_unlock*() (or on a failed
  * mutex_lock_interruptible()).
- *
- * @nested is an hysterical artifact, needs a tree wide cleanup.
  */
 static int
 __lock_release(struct lockdep_map *lock, unsigned long ip)
@@ -4417,7 +5293,7 @@
 	return 0;
 }
 
-static nokprobe_inline
+static __always_inline
 int __lock_is_held(const struct lockdep_map *lock, int read)
 {
 	struct task_struct *curr = current;
@@ -4427,7 +5303,7 @@
 		struct held_lock *hlock = curr->held_locks + i;
 
 		if (match_held_lock(hlock, lock)) {
-			if (read == -1 || hlock->read == read)
+			if (read == -1 || !!hlock->read == read)
 				return 1;
 
 			return 0;
@@ -4515,18 +5391,21 @@
 /*
  * Check whether we follow the irq-flags state precisely:
  */
-static void check_flags(unsigned long flags)
+static noinstr void check_flags(unsigned long flags)
 {
 #if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP)
 	if (!debug_locks)
 		return;
 
+	/* Get the warning out..  */
+	instrumentation_begin();
+
 	if (irqs_disabled_flags(flags)) {
-		if (DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)) {
+		if (DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())) {
 			printk("possible reason: unannotated irqs-off.\n");
 		}
 	} else {
-		if (DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled)) {
+		if (DEBUG_LOCKS_WARN_ON(!lockdep_hardirqs_enabled())) {
 			printk("possible reason: unannotated irqs-on.\n");
 		}
 	}
@@ -4548,6 +5427,8 @@
 
 	if (!debug_locks)
 		print_irqtrace_events(current);
+
+	instrumentation_end();
 #endif
 }
 
@@ -4557,15 +5438,15 @@
 {
 	unsigned long flags;
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return;
 
 	raw_local_irq_save(flags);
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	check_flags(flags);
 	if (__lock_set_class(lock, name, key, subclass, ip))
 		check_chain_key(current);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_set_class);
@@ -4574,19 +5455,71 @@
 {
 	unsigned long flags;
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return;
 
 	raw_local_irq_save(flags);
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	check_flags(flags);
 	if (__lock_downgrade(lock, ip))
 		check_chain_key(current);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_downgrade);
 
+/* NMI context !!! */
+static void verify_lock_unused(struct lockdep_map *lock, struct held_lock *hlock, int subclass)
+{
+#ifdef CONFIG_PROVE_LOCKING
+	struct lock_class *class = look_up_lock_class(lock, subclass);
+	unsigned long mask = LOCKF_USED;
+
+	/* if it doesn't have a class (yet), it certainly hasn't been used yet */
+	if (!class)
+		return;
+
+	/*
+	 * READ locks only conflict with USED, such that if we only ever use
+	 * READ locks, there is no deadlock possible -- RCU.
+	 */
+	if (!hlock->read)
+		mask |= LOCKF_USED_READ;
+
+	if (!(class->usage_mask & mask))
+		return;
+
+	hlock->class_idx = class - lock_classes;
+
+	print_usage_bug(current, hlock, LOCK_USED, LOCK_USAGE_STATES);
+#endif
+}
+
+static bool lockdep_nmi(void)
+{
+	if (raw_cpu_read(lockdep_recursion))
+		return false;
+
+	if (!in_nmi())
+		return false;
+
+	return true;
+}
+
+/*
+ * read_lock() is recursive if:
+ * 1. We force lockdep think this way in selftests or
+ * 2. The implementation is not queued read/write lock or
+ * 3. The locker is at an in_interrupt() context.
+ */
+bool read_lock_is_recursive(void)
+{
+	return force_read_lock_recursive ||
+	       !IS_ENABLED(CONFIG_QUEUED_RWLOCKS) ||
+	       in_interrupt();
+}
+EXPORT_SYMBOL_GPL(read_lock_is_recursive);
+
 /*
  * We are not always called with irqs disabled - do that here,
  * and also avoid lockdep recursion:
@@ -4597,54 +5530,76 @@
 {
 	unsigned long flags;
 
-	if (unlikely(current->lockdep_recursion))
+	trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
+
+	if (!debug_locks)
 		return;
 
+	if (unlikely(!lockdep_enabled())) {
+		/* XXX allow trylock from NMI ?!? */
+		if (lockdep_nmi() && !trylock) {
+			struct held_lock hlock;
+
+			hlock.acquire_ip = ip;
+			hlock.instance = lock;
+			hlock.nest_lock = nest_lock;
+			hlock.irq_context = 2; // XXX
+			hlock.trylock = trylock;
+			hlock.read = read;
+			hlock.check = check;
+			hlock.hardirqs_off = true;
+			hlock.references = 0;
+
+			verify_lock_unused(lock, &hlock, subclass);
+		}
+		return;
+	}
+
 	raw_local_irq_save(flags);
 	check_flags(flags);
 
-	current->lockdep_recursion = 1;
-	trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
+	lockdep_recursion_inc();
 	__lock_acquire(lock, subclass, trylock, read, check,
 		       irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_acquire);
 
-void lock_release(struct lockdep_map *lock, int nested,
-			  unsigned long ip)
+void lock_release(struct lockdep_map *lock, unsigned long ip)
 {
 	unsigned long flags;
 
-	if (unlikely(current->lockdep_recursion))
+	trace_lock_release(lock, ip);
+
+	if (unlikely(!lockdep_enabled()))
 		return;
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
-	current->lockdep_recursion = 1;
-	trace_lock_release(lock, ip);
+
+	lockdep_recursion_inc();
 	if (__lock_release(lock, ip))
 		check_chain_key(current);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_release);
 
-int lock_is_held_type(const struct lockdep_map *lock, int read)
+noinstr int lock_is_held_type(const struct lockdep_map *lock, int read)
 {
 	unsigned long flags;
 	int ret = 0;
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return 1; /* avoid false negative lockdep_assert_held() */
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
 
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	ret = __lock_is_held(lock, read);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 
 	return ret;
@@ -4657,15 +5612,15 @@
 	struct pin_cookie cookie = NIL_COOKIE;
 	unsigned long flags;
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return cookie;
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
 
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	cookie = __lock_pin_lock(lock);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 
 	return cookie;
@@ -4676,15 +5631,15 @@
 {
 	unsigned long flags;
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return;
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
 
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	__lock_repin_lock(lock, cookie);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_repin_lock);
@@ -4693,15 +5648,15 @@
 {
 	unsigned long flags;
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lockdep_enabled()))
 		return;
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
 
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	__lock_unpin_lock(lock, cookie);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_unpin_lock);
@@ -4725,7 +5680,7 @@
 		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
 	pr_cont(") at:\n");
-	print_ip_sym(ip);
+	print_ip_sym(KERN_WARNING, ip);
 	pr_warn("but there are no locks held!\n");
 	pr_warn("\nother info that might help us debug this:\n");
 	lockdep_print_held_locks(curr);
@@ -4809,8 +5764,6 @@
 		hlock->holdtime_stamp = now;
 	}
 
-	trace_lock_acquired(lock, ip);
-
 	stats = get_lock_stats(hlock_class(hlock));
 	if (waittime) {
 		if (hlock->read)
@@ -4829,18 +5782,16 @@
 {
 	unsigned long flags;
 
-	if (unlikely(!lock_stat || !debug_locks))
-		return;
+	trace_lock_contended(lock, ip);
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lock_stat || !lockdep_enabled()))
 		return;
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
-	current->lockdep_recursion = 1;
-	trace_lock_contended(lock, ip);
+	lockdep_recursion_inc();
 	__lock_contended(lock, ip);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_contended);
@@ -4849,17 +5800,16 @@
 {
 	unsigned long flags;
 
-	if (unlikely(!lock_stat || !debug_locks))
-		return;
+	trace_lock_acquired(lock, ip);
 
-	if (unlikely(current->lockdep_recursion))
+	if (unlikely(!lock_stat || !lockdep_enabled()))
 		return;
 
 	raw_local_irq_save(flags);
 	check_flags(flags);
-	current->lockdep_recursion = 1;
+	lockdep_recursion_inc();
 	__lock_acquired(lock, ip);
-	current->lockdep_recursion = 0;
+	lockdep_recursion_finish();
 	raw_local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(lock_acquired);
@@ -4893,36 +5843,24 @@
 					 struct lock_class *class)
 {
 #ifdef CONFIG_PROVE_LOCKING
-	struct lock_chain *new_chain;
-	u64 chain_key;
 	int i;
 
 	for (i = chain->base; i < chain->base + chain->depth; i++) {
-		if (chain_hlocks[i] != class - lock_classes)
+		if (chain_hlock_class_idx(chain_hlocks[i]) != class - lock_classes)
 			continue;
-		/* The code below leaks one chain_hlock[] entry. */
-		if (--chain->depth > 0) {
-			memmove(&chain_hlocks[i], &chain_hlocks[i + 1],
-				(chain->base + chain->depth - i) *
-				sizeof(chain_hlocks[0]));
-		}
 		/*
 		 * Each lock class occurs at most once in a lock chain so once
 		 * we found a match we can break out of this loop.
 		 */
-		goto recalc;
+		goto free_lock_chain;
 	}
 	/* Since the chain has not been modified, return. */
 	return;
 
-recalc:
-	chain_key = INITIAL_CHAIN_KEY;
-	for (i = chain->base; i < chain->base + chain->depth; i++)
-		chain_key = iterate_chain_key(chain_key, chain_hlocks[i]);
-	if (chain->depth && chain->chain_key == chain_key)
-		return;
+free_lock_chain:
+	free_chain_hlocks(chain->base, chain->depth);
 	/* Overwrite the chain key for concurrent RCU readers. */
-	WRITE_ONCE(chain->chain_key, chain_key);
+	WRITE_ONCE(chain->chain_key, INITIAL_CHAIN_KEY);
 	dec_chains(chain->irq_context);
 
 	/*
@@ -4931,22 +5869,7 @@
 	 */
 	hlist_del_rcu(&chain->entry);
 	__set_bit(chain - lock_chains, pf->lock_chains_being_freed);
-	if (chain->depth == 0)
-		return;
-	/*
-	 * If the modified lock chain matches an existing lock chain, drop
-	 * the modified lock chain.
-	 */
-	if (lookup_chain_cache(chain_key))
-		return;
-	new_chain = alloc_lock_chain();
-	if (WARN_ON_ONCE(!new_chain)) {
-		debug_locks_off();
-		return;
-	}
-	*new_chain = *chain;
-	hlist_add_head_rcu(&new_chain->entry, chainhashentry(chain_key));
-	inc_chains(new_chain->irq_context);
+	nr_zapped_lock_chains++;
 #endif
 }
 
@@ -5002,6 +5925,7 @@
 	}
 
 	remove_class_from_lock_chains(pf, class);
+	nr_zapped_classes++;
 }
 
 static void reinit_class(struct lock_class *class)
@@ -5086,8 +6010,7 @@
 		return;
 
 	raw_local_irq_save(flags);
-	arch_spin_lock(&lockdep_lock);
-	current->lockdep_recursion = 1;
+	lockdep_lock();
 
 	/* closed head */
 	pf = delayed_free.pf + (delayed_free.index ^ 1);
@@ -5099,8 +6022,7 @@
 	 */
 	call_rcu_zapped(delayed_free.pf + delayed_free.index);
 
-	current->lockdep_recursion = 0;
-	arch_spin_unlock(&lockdep_lock);
+	lockdep_unlock();
 	raw_local_irq_restore(flags);
 }
 
@@ -5145,13 +6067,11 @@
 	init_data_structures_once();
 
 	raw_local_irq_save(flags);
-	arch_spin_lock(&lockdep_lock);
-	current->lockdep_recursion = 1;
+	lockdep_lock();
 	pf = get_pending_free();
 	__lockdep_free_key_range(pf, start, size);
 	call_rcu_zapped(pf);
-	current->lockdep_recursion = 0;
-	arch_spin_unlock(&lockdep_lock);
+	lockdep_unlock();
 	raw_local_irq_restore(flags);
 
 	/*
@@ -5173,10 +6093,10 @@
 	init_data_structures_once();
 
 	raw_local_irq_save(flags);
-	arch_spin_lock(&lockdep_lock);
+	lockdep_lock();
 	__lockdep_free_key_range(pf, start, size);
 	__free_zapped_classes(pf);
-	arch_spin_unlock(&lockdep_lock);
+	lockdep_unlock();
 	raw_local_irq_restore(flags);
 }
 
@@ -5272,10 +6192,10 @@
 	unsigned long flags;
 
 	raw_local_irq_save(flags);
-	arch_spin_lock(&lockdep_lock);
+	lockdep_lock();
 	__lockdep_reset_lock(pf, lock);
 	__free_zapped_classes(pf);
-	arch_spin_unlock(&lockdep_lock);
+	lockdep_unlock();
 	raw_local_irq_restore(flags);
 }
 
@@ -5531,9 +6451,7 @@
 	pr_warn("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
 	       !rcu_lockdep_current_cpu_online()
 			? "RCU used illegally from offline CPU!\n"
-			: !rcu_is_watching()
-				? "RCU used illegally from idle CPU!\n"
-				: "",
+			: "",
 	       rcu_scheduler_active, debug_locks);
 
 	/*
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index a525368..de49f9e 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -19,9 +19,13 @@
 #include "lockdep_states.h"
 #undef LOCKDEP_STATE
 	LOCK_USED,
-	LOCK_USAGE_STATES
+	LOCK_USED_READ,
+	LOCK_USAGE_STATES,
 };
 
+/* states after LOCK_USED_READ are not traced and printed */
+static_assert(LOCK_TRACE_STATES == LOCK_USAGE_STATES);
+
 #define LOCK_USAGE_READ_MASK 1
 #define LOCK_USAGE_DIR_MASK  2
 #define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK))
@@ -40,6 +44,7 @@
 #include "lockdep_states.h"
 #undef LOCKDEP_STATE
 	__LOCKF(USED)
+	__LOCKF(USED_READ)
 };
 
 #define LOCKDEP_STATE(__STATE)	LOCKF_ENABLED_##__STATE |
@@ -119,7 +124,7 @@
 extern struct list_head all_lock_classes;
 extern struct lock_chain lock_chains[];
 
-#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
+#define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)
 
 extern void get_usage_chars(struct lock_class *class,
 			    char usage[LOCK_USAGE_CHARS]);
@@ -130,17 +135,21 @@
 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
 
 extern unsigned long nr_lock_classes;
+extern unsigned long nr_zapped_classes;
+extern unsigned long nr_zapped_lock_chains;
 extern unsigned long nr_list_entries;
 long lockdep_next_lockchain(long i);
 unsigned long lock_chain_count(void);
-extern int nr_chain_hlocks;
 extern unsigned long nr_stack_trace_entries;
 
 extern unsigned int nr_hardirq_chains;
 extern unsigned int nr_softirq_chains;
 extern unsigned int nr_process_chains;
-extern unsigned int max_lockdep_depth;
+extern unsigned int nr_free_chain_hlocks;
+extern unsigned int nr_lost_chain_hlocks;
+extern unsigned int nr_large_chain_blocks;
 
+extern unsigned int max_lockdep_depth;
 extern unsigned int max_bfs_queue_depth;
 
 #ifdef CONFIG_PROVE_LOCKING
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 581f818..02ef87f 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -128,15 +128,22 @@
 	struct lock_chain *chain = v;
 	struct lock_class *class;
 	int i;
+	static const char * const irq_strs[] = {
+		[0]			     = "0",
+		[LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq",
+		[LOCK_CHAIN_SOFTIRQ_CONTEXT] = "softirq",
+		[LOCK_CHAIN_SOFTIRQ_CONTEXT|
+		 LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq|softirq",
+	};
 
 	if (v == SEQ_START_TOKEN) {
-		if (nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)
+		if (!nr_free_chain_hlocks)
 			seq_printf(m, "(buggered) ");
 		seq_printf(m, "all lock chains:\n");
 		return 0;
 	}
 
-	seq_printf(m, "irq_context: %d\n", chain->irq_context);
+	seq_printf(m, "irq_context: %s\n", irq_strs[chain->irq_context]);
 
 	for (i = 0; i < chain->depth; i++) {
 		class = lock_chain_get_class(chain, i);
@@ -271,8 +278,12 @@
 #ifdef CONFIG_PROVE_LOCKING
 	seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
 			lock_chain_count(), MAX_LOCKDEP_CHAINS);
-	seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",
-			nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
+	seq_printf(m, " dependency chain hlocks used:  %11lu [max: %lu]\n",
+			MAX_LOCKDEP_CHAIN_HLOCKS -
+			(nr_free_chain_hlocks + nr_lost_chain_hlocks),
+			MAX_LOCKDEP_CHAIN_HLOCKS);
+	seq_printf(m, " dependency chain hlocks lost:  %11u\n",
+			nr_lost_chain_hlocks);
 #endif
 
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -336,6 +347,18 @@
 	seq_printf(m, " debug_locks:                   %11u\n",
 			debug_locks);
 
+	/*
+	 * Zappped classes and lockdep data buffers reuse statistics.
+	 */
+	seq_puts(m, "\n");
+	seq_printf(m, " zapped classes:                %11lu\n",
+			nr_zapped_classes);
+#ifdef CONFIG_PROVE_LOCKING
+	seq_printf(m, " zapped lock chains:            %11lu\n",
+			nr_zapped_lock_chains);
+	seq_printf(m, " large chain blocks:            %11u\n",
+			nr_large_chain_blocks);
+#endif
 	return 0;
 }
 
@@ -643,12 +666,12 @@
 	return seq_release(inode, file);
 }
 
-static const struct file_operations proc_lock_stat_operations = {
-	.open		= lock_stat_open,
-	.write		= lock_stat_write,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= lock_stat_release,
+static const struct proc_ops lock_stat_proc_ops = {
+	.proc_open	= lock_stat_open,
+	.proc_write	= lock_stat_write,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= lock_stat_release,
 };
 #endif /* CONFIG_LOCK_STAT */
 
@@ -660,8 +683,7 @@
 #endif
 	proc_create_single("lockdep_stats", S_IRUSR, NULL, lockdep_stats_show);
 #ifdef CONFIG_LOCK_STAT
-	proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL,
-		    &proc_lock_stat_operations);
+	proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL, &lock_stat_proc_ops);
 #endif
 
 	return 0;
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index e095628..62d215b 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -16,7 +16,6 @@
 #include <linux/kthread.h>
 #include <linux/sched/rt.h>
 #include <linux/spinlock.h>
-#include <linux/rwlock.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
 #include <linux/smp.h>
@@ -437,8 +436,6 @@
 
 static void torture_rtmutex_boost(struct torture_random_state *trsp)
 {
-	int policy;
-	struct sched_param param;
 	const unsigned int factor = 50000; /* yes, quite arbitrary */
 
 	if (!rt_task(current)) {
@@ -449,8 +446,7 @@
 		 */
 		if (trsp && !(torture_random(trsp) %
 			      (cxt.nrealwriters_stress * factor))) {
-			policy = SCHED_FIFO;
-			param.sched_priority = MAX_RT_PRIO - 1;
+			sched_set_fifo(current);
 		} else /* common case, do nothing */
 			return;
 	} else {
@@ -463,13 +459,10 @@
 		 */
 		if (!trsp || !(torture_random(trsp) %
 			       (cxt.nrealwriters_stress * factor * 2))) {
-			policy = SCHED_NORMAL;
-			param.sched_priority = 0;
+			sched_set_normal(current, 0);
 		} else /* common case, do nothing */
 			return;
 	}
-
-	sched_setscheduler_nocheck(current, policy, &param);
 }
 
 static void torture_rtmutex_delay(struct torture_random_state *trsp)
@@ -573,7 +566,7 @@
 #include <linux/percpu-rwsem.h>
 static struct percpu_rw_semaphore pcpu_rwsem;
 
-void torture_percpu_rwsem_init(void)
+static void torture_percpu_rwsem_init(void)
 {
 	BUG_ON(percpu_init_rwsem(&pcpu_rwsem));
 }
@@ -619,7 +612,7 @@
 static int lock_torture_writer(void *arg)
 {
 	struct lock_stress_stats *lwsp = arg;
-	static DEFINE_TORTURE_RANDOM(rand);
+	DEFINE_TORTURE_RANDOM(rand);
 
 	VERBOSE_TOROUT_STRING("lock_torture_writer task started");
 	set_user_nice(current, MAX_NICE);
@@ -632,13 +625,13 @@
 		cxt.cur_ops->writelock();
 		if (WARN_ON_ONCE(lock_is_write_held))
 			lwsp->n_lock_fail++;
-		lock_is_write_held = 1;
+		lock_is_write_held = true;
 		if (WARN_ON_ONCE(lock_is_read_held))
 			lwsp->n_lock_fail++; /* rare, but... */
 
 		lwsp->n_lock_acquired++;
 		cxt.cur_ops->write_delay(&rand);
-		lock_is_write_held = 0;
+		lock_is_write_held = false;
 		cxt.cur_ops->writeunlock();
 
 		stutter_wait("lock_torture_writer");
@@ -656,7 +649,7 @@
 static int lock_torture_reader(void *arg)
 {
 	struct lock_stress_stats *lrsp = arg;
-	static DEFINE_TORTURE_RANDOM(rand);
+	DEFINE_TORTURE_RANDOM(rand);
 
 	VERBOSE_TOROUT_STRING("lock_torture_reader task started");
 	set_user_nice(current, MAX_NICE);
@@ -666,13 +659,13 @@
 			schedule_timeout_uninterruptible(1);
 
 		cxt.cur_ops->readlock();
-		lock_is_read_held = 1;
+		lock_is_read_held = true;
 		if (WARN_ON_ONCE(lock_is_write_held))
 			lrsp->n_lock_fail++; /* rare, but... */
 
 		lrsp->n_lock_acquired++;
 		cxt.cur_ops->read_delay(&rand);
-		lock_is_read_held = 0;
+		lock_is_read_held = false;
 		cxt.cur_ops->readunlock();
 
 		stutter_wait("lock_torture_reader");
@@ -687,7 +680,7 @@
 static void __torture_print_stats(char *page,
 				  struct lock_stress_stats *statp, bool write)
 {
-	bool fail = 0;
+	bool fail = false;
 	int i, n_stress;
 	long max = 0, min = statp ? statp[0].n_lock_acquired : 0;
 	long long sum = 0;
@@ -705,7 +698,8 @@
 	page += sprintf(page,
 			"%s:  Total: %lld  Max/Min: %ld/%ld %s  Fail: %d %s\n",
 			write ? "Writes" : "Reads ",
-			sum, max, min, max / 2 > min ? "???" : "",
+			sum, max, min,
+			!onoff_interval && max / 2 > min ? "???" : "",
 			fail, fail ? "!!!" : "");
 	if (fail)
 		atomic_inc(&cxt.n_lock_torture_errors);
@@ -889,22 +883,22 @@
 		cxt.nrealwriters_stress = 2 * num_online_cpus();
 
 #ifdef CONFIG_DEBUG_MUTEXES
-	if (strncmp(torture_type, "mutex", 5) == 0)
+	if (str_has_prefix(torture_type, "mutex"))
 		cxt.debug_lock = true;
 #endif
 #ifdef CONFIG_DEBUG_RT_MUTEXES
-	if (strncmp(torture_type, "rtmutex", 7) == 0)
+	if (str_has_prefix(torture_type, "rtmutex"))
 		cxt.debug_lock = true;
 #endif
 #ifdef CONFIG_DEBUG_SPINLOCK
-	if ((strncmp(torture_type, "spin", 4) == 0) ||
-	    (strncmp(torture_type, "rw_lock", 7) == 0))
+	if ((str_has_prefix(torture_type, "spin")) ||
+	    (str_has_prefix(torture_type, "rw_lock")))
 		cxt.debug_lock = true;
 #endif
 
 	/* Initialize the statistics so that each run gets its own numbers. */
 	if (nwriters_stress) {
-		lock_is_write_held = 0;
+		lock_is_write_held = false;
 		cxt.lwsa = kmalloc_array(cxt.nrealwriters_stress,
 					 sizeof(*cxt.lwsa),
 					 GFP_KERNEL);
@@ -935,7 +929,7 @@
 		}
 
 		if (nreaders_stress) {
-			lock_is_read_held = 0;
+			lock_is_read_held = false;
 			cxt.lrsa = kmalloc_array(cxt.nrealreaders_stress,
 						 sizeof(*cxt.lrsa),
 						 GFP_KERNEL);
diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index 4fe4091..db93015 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -85,7 +85,7 @@
 	 * Make sure we are not reinitializing a held lock:
 	 */
 	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
-	lockdep_init_map(&lock->dep_map, name, key, 0);
+	lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP);
 #endif
 	lock->magic = lock;
 }
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index b02fff2..8606190 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -1097,7 +1097,7 @@
 err_early_kill:
 	spin_unlock(&lock->wait_lock);
 	debug_mutex_free_waiter(&waiter);
-	mutex_release(&lock->dep_map, 1, ip);
+	mutex_release(&lock->dep_map, ip);
 	preempt_enable();
 	return ret;
 }
@@ -1231,7 +1231,7 @@
 	DEFINE_WAKE_Q(wake_q);
 	unsigned long owner;
 
-	mutex_release(&lock->dep_map, 1, ip);
+	mutex_release(&lock->dep_map, ip);
 
 	/*
 	 * Release the lock before (potentially) taking the spinlock such that
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 6ef600a..1de006e 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -134,20 +134,17 @@
 	 * cmpxchg in an attempt to undo our queueing.
 	 */
 
-	while (!READ_ONCE(node->locked)) {
-		/*
-		 * If we need to reschedule bail... so we can block.
-		 * Use vcpu_is_preempted() to avoid waiting for a preempted
-		 * lock holder:
-		 */
-		if (need_resched() || vcpu_is_preempted(node_cpu(node->prev)))
-			goto unqueue;
+	/*
+	 * Wait to acquire the lock or cancelation. Note that need_resched()
+	 * will come with an IPI, which will wake smp_cond_load_relaxed() if it
+	 * is implemented with a monitor-wait. vcpu_is_preempted() relies on
+	 * polling, be careful.
+	 */
+	if (smp_cond_load_relaxed(&node->locked, VAL || need_resched() ||
+				  vcpu_is_preempted(node_cpu(node->prev))))
+		return true;
 
-		cpu_relax();
-	}
-	return true;
-
-unqueue:
+	/* unqueue */
 	/*
 	 * Step - A  -- stabilize @prev
 	 *
@@ -157,7 +154,11 @@
 	 */
 
 	for (;;) {
-		if (prev->next == node &&
+		/*
+		 * cpu_relax() below implies a compiler barrier which would
+		 * prevent this comparison being optimized away.
+		 */
+		if (data_race(prev->next) == node &&
 		    cmpxchg(&prev->next, node, NULL) == node)
 			break;
 
diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c
index 364d38a..70a32a5 100644
--- a/kernel/locking/percpu-rwsem.c
+++ b/kernel/locking/percpu-rwsem.c
@@ -1,27 +1,29 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #include <linux/atomic.h>
-#include <linux/rwsem.h>
 #include <linux/percpu.h>
+#include <linux/wait.h>
 #include <linux/lockdep.h>
 #include <linux/percpu-rwsem.h>
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
+#include <linux/sched/task.h>
 #include <linux/errno.h>
 
-#include "rwsem.h"
-
 int __percpu_init_rwsem(struct percpu_rw_semaphore *sem,
-			const char *name, struct lock_class_key *rwsem_key)
+			const char *name, struct lock_class_key *key)
 {
 	sem->read_count = alloc_percpu(int);
 	if (unlikely(!sem->read_count))
 		return -ENOMEM;
 
-	/* ->rw_sem represents the whole percpu_rw_semaphore for lockdep */
 	rcu_sync_init(&sem->rss);
-	__init_rwsem(&sem->rw_sem, name, rwsem_key);
 	rcuwait_init(&sem->writer);
-	sem->readers_block = 0;
+	init_waitqueue_head(&sem->waiters);
+	atomic_set(&sem->block, 0);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	debug_check_no_locks_freed((void *)sem, sizeof(*sem));
+	lockdep_init_map(&sem->dep_map, name, key, 0);
+#endif
 	return 0;
 }
 EXPORT_SYMBOL_GPL(__percpu_init_rwsem);
@@ -41,74 +43,141 @@
 }
 EXPORT_SYMBOL_GPL(percpu_free_rwsem);
 
-int __percpu_down_read(struct percpu_rw_semaphore *sem, int try)
+static bool __percpu_down_read_trylock(struct percpu_rw_semaphore *sem)
 {
+	this_cpu_inc(*sem->read_count);
+
 	/*
 	 * Due to having preemption disabled the decrement happens on
 	 * the same CPU as the increment, avoiding the
 	 * increment-on-one-CPU-and-decrement-on-another problem.
 	 *
-	 * If the reader misses the writer's assignment of readers_block, then
-	 * the writer is guaranteed to see the reader's increment.
+	 * If the reader misses the writer's assignment of sem->block, then the
+	 * writer is guaranteed to see the reader's increment.
 	 *
 	 * Conversely, any readers that increment their sem->read_count after
-	 * the writer looks are guaranteed to see the readers_block value,
-	 * which in turn means that they are guaranteed to immediately
-	 * decrement their sem->read_count, so that it doesn't matter that the
-	 * writer missed them.
+	 * the writer looks are guaranteed to see the sem->block value, which
+	 * in turn means that they are guaranteed to immediately decrement
+	 * their sem->read_count, so that it doesn't matter that the writer
+	 * missed them.
 	 */
 
 	smp_mb(); /* A matches D */
 
 	/*
-	 * If !readers_block the critical section starts here, matched by the
+	 * If !sem->block the critical section starts here, matched by the
 	 * release in percpu_up_write().
 	 */
-	if (likely(!smp_load_acquire(&sem->readers_block)))
+	if (likely(!atomic_read_acquire(&sem->block)))
+		return true;
+
+	this_cpu_dec(*sem->read_count);
+
+	/* Prod writer to re-evaluate readers_active_check() */
+	rcuwait_wake_up(&sem->writer);
+
+	return false;
+}
+
+static inline bool __percpu_down_write_trylock(struct percpu_rw_semaphore *sem)
+{
+	if (atomic_read(&sem->block))
+		return false;
+
+	return atomic_xchg(&sem->block, 1) == 0;
+}
+
+static bool __percpu_rwsem_trylock(struct percpu_rw_semaphore *sem, bool reader)
+{
+	if (reader) {
+		bool ret;
+
+		preempt_disable();
+		ret = __percpu_down_read_trylock(sem);
+		preempt_enable();
+
+		return ret;
+	}
+	return __percpu_down_write_trylock(sem);
+}
+
+/*
+ * The return value of wait_queue_entry::func means:
+ *
+ *  <0 - error, wakeup is terminated and the error is returned
+ *   0 - no wakeup, a next waiter is tried
+ *  >0 - woken, if EXCLUSIVE, counted towards @nr_exclusive.
+ *
+ * We use EXCLUSIVE for both readers and writers to preserve FIFO order,
+ * and play games with the return value to allow waking multiple readers.
+ *
+ * Specifically, we wake readers until we've woken a single writer, or until a
+ * trylock fails.
+ */
+static int percpu_rwsem_wake_function(struct wait_queue_entry *wq_entry,
+				      unsigned int mode, int wake_flags,
+				      void *key)
+{
+	bool reader = wq_entry->flags & WQ_FLAG_CUSTOM;
+	struct percpu_rw_semaphore *sem = key;
+	struct task_struct *p;
+
+	/* concurrent against percpu_down_write(), can get stolen */
+	if (!__percpu_rwsem_trylock(sem, reader))
 		return 1;
 
+	p = get_task_struct(wq_entry->private);
+	list_del_init(&wq_entry->entry);
+	smp_store_release(&wq_entry->private, NULL);
+
+	wake_up_process(p);
+	put_task_struct(p);
+
+	return !reader; /* wake (readers until) 1 writer */
+}
+
+static void percpu_rwsem_wait(struct percpu_rw_semaphore *sem, bool reader)
+{
+	DEFINE_WAIT_FUNC(wq_entry, percpu_rwsem_wake_function);
+	bool wait;
+
+	spin_lock_irq(&sem->waiters.lock);
 	/*
-	 * Per the above comment; we still have preemption disabled and
-	 * will thus decrement on the same CPU as we incremented.
+	 * Serialize against the wakeup in percpu_up_write(), if we fail
+	 * the trylock, the wakeup must see us on the list.
 	 */
-	__percpu_up_read(sem);
+	wait = !__percpu_rwsem_trylock(sem, reader);
+	if (wait) {
+		wq_entry.flags |= WQ_FLAG_EXCLUSIVE | reader * WQ_FLAG_CUSTOM;
+		__add_wait_queue_entry_tail(&sem->waiters, &wq_entry);
+	}
+	spin_unlock_irq(&sem->waiters.lock);
+
+	while (wait) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (!smp_load_acquire(&wq_entry.private))
+			break;
+		schedule();
+	}
+	__set_current_state(TASK_RUNNING);
+}
+
+bool __percpu_down_read(struct percpu_rw_semaphore *sem, bool try)
+{
+	if (__percpu_down_read_trylock(sem))
+		return true;
 
 	if (try)
-		return 0;
+		return false;
 
-	/*
-	 * We either call schedule() in the wait, or we'll fall through
-	 * and reschedule on the preempt_enable() in percpu_down_read().
-	 */
-	preempt_enable_no_resched();
-
-	/*
-	 * Avoid lockdep for the down/up_read() we already have them.
-	 */
-	__down_read(&sem->rw_sem);
-	this_cpu_inc(*sem->read_count);
-	__up_read(&sem->rw_sem);
-
+	preempt_enable();
+	percpu_rwsem_wait(sem, /* .reader = */ true);
 	preempt_disable();
-	return 1;
+
+	return true;
 }
 EXPORT_SYMBOL_GPL(__percpu_down_read);
 
-void __percpu_up_read(struct percpu_rw_semaphore *sem)
-{
-	smp_mb(); /* B matches C */
-	/*
-	 * In other words, if they see our decrement (presumably to aggregate
-	 * zero, as that is the only time it matters) they will also see our
-	 * critical section.
-	 */
-	__this_cpu_dec(*sem->read_count);
-
-	/* Prod writer to recheck readers_active */
-	rcuwait_wake_up(&sem->writer);
-}
-EXPORT_SYMBOL_GPL(__percpu_up_read);
-
 #define per_cpu_sum(var)						\
 ({									\
 	typeof(var) __sum = 0;						\
@@ -124,6 +193,8 @@
  * zero.  If this sum is zero, then it is stable due to the fact that if any
  * newly arriving readers increment a given counter, they will immediately
  * decrement that same counter.
+ *
+ * Assumes sem->block is set.
  */
 static bool readers_active_check(struct percpu_rw_semaphore *sem)
 {
@@ -142,32 +213,36 @@
 
 void percpu_down_write(struct percpu_rw_semaphore *sem)
 {
+	might_sleep();
+	rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
+
 	/* Notify readers to take the slow path. */
 	rcu_sync_enter(&sem->rss);
 
-	down_write(&sem->rw_sem);
+	/*
+	 * Try set sem->block; this provides writer-writer exclusion.
+	 * Having sem->block set makes new readers block.
+	 */
+	if (!__percpu_down_write_trylock(sem))
+		percpu_rwsem_wait(sem, /* .reader = */ false);
+
+	/* smp_mb() implied by __percpu_down_write_trylock() on success -- D matches A */
 
 	/*
-	 * Notify new readers to block; up until now, and thus throughout the
-	 * longish rcu_sync_enter() above, new readers could still come in.
-	 */
-	WRITE_ONCE(sem->readers_block, 1);
-
-	smp_mb(); /* D matches A */
-
-	/*
-	 * If they don't see our writer of readers_block, then we are
-	 * guaranteed to see their sem->read_count increment, and therefore
-	 * will wait for them.
+	 * If they don't see our store of sem->block, then we are guaranteed to
+	 * see their sem->read_count increment, and therefore will wait for
+	 * them.
 	 */
 
-	/* Wait for all now active readers to complete. */
-	rcuwait_wait_event(&sem->writer, readers_active_check(sem));
+	/* Wait for all active readers to complete. */
+	rcuwait_wait_event(&sem->writer, readers_active_check(sem), TASK_UNINTERRUPTIBLE);
 }
 EXPORT_SYMBOL_GPL(percpu_down_write);
 
 void percpu_up_write(struct percpu_rw_semaphore *sem)
 {
+	rwsem_release(&sem->dep_map, _RET_IP_);
+
 	/*
 	 * Signal the writer is done, no fast path yet.
 	 *
@@ -178,12 +253,12 @@
 	 * Therefore we force it through the slow path which guarantees an
 	 * acquire and thereby guarantees the critical section's consistency.
 	 */
-	smp_store_release(&sem->readers_block, 0);
+	atomic_set_release(&sem->block, 0);
 
 	/*
-	 * Release the write lock, this will allow readers back in the game.
+	 * Prod any pending reader/writer to make progress.
 	 */
-	up_write(&sem->rw_sem);
+	__wake_up(&sem->waiters, TASK_NORMAL, 1, sem);
 
 	/*
 	 * Once this completes (at least one RCU-sched grace period hence) the
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 2473f10..cbff6ba 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -31,14 +31,15 @@
 /*
  * The basic principle of a queue-based spinlock can best be understood
  * by studying a classic queue-based spinlock implementation called the
- * MCS lock. The paper below provides a good description for this kind
- * of lock.
+ * MCS lock. A copy of the original MCS lock paper ("Algorithms for Scalable
+ * Synchronization on Shared-Memory Multiprocessors by Mellor-Crummey and
+ * Scott") is available at
  *
- * http://www.cise.ufl.edu/tr/DOC/REP-1992-71.pdf
+ * https://bugzilla.kernel.org/show_bug.cgi?id=206115
  *
- * This queued spinlock implementation is based on the MCS lock, however to make
- * it fit the 4 bytes we assume spinlock_t to be, and preserve its existing
- * API, we must modify it somehow.
+ * This queued spinlock implementation is based on the MCS lock, however to
+ * make it fit the 4 bytes we assume spinlock_t to be, and preserve its
+ * existing API, we must modify it somehow.
  *
  * In particular; where the traditional MCS lock consists of a tail pointer
  * (8 bytes) and needs the next pointer (another 8 bytes) of its own node to
@@ -580,4 +581,11 @@
 #include "qspinlock_paravirt.h"
 #include "qspinlock.c"
 
+bool nopvspin __initdata;
+static __init int parse_nopvspin(char *arg)
+{
+	nopvspin = true;
+	return 0;
+}
+early_param("nopvspin", parse_nopvspin);
 #endif
diff --git a/kernel/locking/rtmutex-debug.c b/kernel/locking/rtmutex-debug.c
index fd4fe1f..36e6910 100644
--- a/kernel/locking/rtmutex-debug.c
+++ b/kernel/locking/rtmutex-debug.c
@@ -125,7 +125,7 @@
 
 	printk("\n%s/%d's [blocked] stackdump:\n\n",
 		task->comm, task_pid_nr(task));
-	show_stack(task, NULL);
+	show_stack(task, NULL, KERN_DEFAULT);
 	printk("\n%s/%d's [current] stackdump:\n\n",
 		current->comm, task_pid_nr(current));
 	dump_stack();
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 734698a..f00dd92 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -57,7 +57,7 @@
 	if (rt_mutex_has_waiters(lock))
 		val |= RT_MUTEX_HAS_WAITERS;
 
-	lock->owner = (struct task_struct *)val;
+	WRITE_ONCE(lock->owner, (struct task_struct *)val);
 }
 
 static inline void clear_rt_mutex_waiters(struct rt_mutex *lock)
@@ -141,7 +141,6 @@
  * set up.
  */
 #ifndef CONFIG_DEBUG_RT_MUTEXES
-# define rt_mutex_cmpxchg_relaxed(l,c,n) (cmpxchg_relaxed(&l->owner, c, n) == c)
 # define rt_mutex_cmpxchg_acquire(l,c,n) (cmpxchg_acquire(&l->owner, c, n) == c)
 # define rt_mutex_cmpxchg_release(l,c,n) (cmpxchg_release(&l->owner, c, n) == c)
 
@@ -202,7 +201,6 @@
 }
 
 #else
-# define rt_mutex_cmpxchg_relaxed(l,c,n)	(0)
 # define rt_mutex_cmpxchg_acquire(l,c,n)	(0)
 # define rt_mutex_cmpxchg_release(l,c,n)	(0)
 
@@ -1440,7 +1438,7 @@
 }
 
 /*
- * Performs the wakeup of the the top-waiter and re-enables preemption.
+ * Performs the wakeup of the top-waiter and re-enables preemption.
  */
 void rt_mutex_postunlock(struct wake_q_head *wake_q)
 {
@@ -1517,7 +1515,7 @@
 	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
 	ret = rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
 	if (ret)
-		mutex_release(&lock->dep_map, 1, _RET_IP_);
+		mutex_release(&lock->dep_map, _RET_IP_);
 
 	return ret;
 }
@@ -1561,7 +1559,7 @@
 				       RT_MUTEX_MIN_CHAINWALK,
 				       rt_mutex_slowlock);
 	if (ret)
-		mutex_release(&lock->dep_map, 1, _RET_IP_);
+		mutex_release(&lock->dep_map, _RET_IP_);
 
 	return ret;
 }
@@ -1600,7 +1598,7 @@
  */
 void __sched rt_mutex_unlock(struct rt_mutex *lock)
 {
-	mutex_release(&lock->dep_map, 1, _RET_IP_);
+	mutex_release(&lock->dep_map, _RET_IP_);
 	rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_unlock);
@@ -1834,7 +1832,7 @@
  *			been started.
  * @waiter:		the pre-initialized rt_mutex_waiter
  *
- * Wait for the the lock acquisition started on our behalf by
+ * Wait for the lock acquisition started on our behalf by
  * rt_mutex_start_proxy_lock(). Upon failure, the caller must call
  * rt_mutex_cleanup_proxy_lock().
  *
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 5d54ff3..cc5cc88 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -28,7 +28,6 @@
 #include <linux/rwsem.h>
 #include <linux/atomic.h>
 
-#include "rwsem.h"
 #include "lock_events.h"
 
 /*
@@ -329,7 +328,7 @@
 	 * Make sure we are not reinitializing a held semaphore:
 	 */
 	debug_check_no_locks_freed((void *)sem, sizeof(*sem));
-	lockdep_init_map(&sem->dep_map, name, key, 0);
+	lockdep_init_map_wait(&sem->dep_map, name, key, 0, LD_WAIT_SLEEP);
 #endif
 #ifdef CONFIG_DEBUG_RWSEMS
 	sem->magic = sem;
@@ -660,8 +659,6 @@
 	unsigned long flags;
 	bool ret = true;
 
-	BUILD_BUG_ON(!(RWSEM_OWNER_UNKNOWN & RWSEM_NONSPINNABLE));
-
 	if (need_resched()) {
 		lockevent_inc(rwsem_opt_fail);
 		return false;
@@ -1180,7 +1177,7 @@
 
 		/*
 		 * If there were already threads queued before us and:
-		 *  1) there are no no active locks, wake the front
+		 *  1) there are no active locks, wake the front
 		 *     queued process(es) as the handoff bit might be set.
 		 *  2) there are no active writers and some readers, the lock
 		 *     must be read owned; so we try to wake any read lock
@@ -1338,7 +1335,7 @@
 /*
  * lock for reading
  */
-inline void __down_read(struct rw_semaphore *sem)
+static inline void __down_read(struct rw_semaphore *sem)
 {
 	if (!rwsem_read_trylock(sem)) {
 		rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE);
@@ -1438,7 +1435,7 @@
 /*
  * unlock after reading
  */
-inline void __up_read(struct rw_semaphore *sem)
+static inline void __up_read(struct rw_semaphore *sem)
 {
 	long tmp;
 
@@ -1516,7 +1513,7 @@
 	rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
 
 	if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_interruptible)) {
-		rwsem_release(&sem->dep_map, 1, _RET_IP_);
+		rwsem_release(&sem->dep_map, _RET_IP_);
 		return -EINTR;
 	}
 
@@ -1530,7 +1527,7 @@
 	rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
 
 	if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_killable)) {
-		rwsem_release(&sem->dep_map, 1, _RET_IP_);
+		rwsem_release(&sem->dep_map, _RET_IP_);
 		return -EINTR;
 	}
 
@@ -1572,7 +1569,7 @@
 
 	if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock,
 				  __down_write_killable)) {
-		rwsem_release(&sem->dep_map, 1, _RET_IP_);
+		rwsem_release(&sem->dep_map, _RET_IP_);
 		return -EINTR;
 	}
 
@@ -1599,7 +1596,7 @@
  */
 void up_read(struct rw_semaphore *sem)
 {
-	rwsem_release(&sem->dep_map, 1, _RET_IP_);
+	rwsem_release(&sem->dep_map, _RET_IP_);
 	__up_read(sem);
 }
 EXPORT_SYMBOL(up_read);
@@ -1609,7 +1606,7 @@
  */
 void up_write(struct rw_semaphore *sem)
 {
-	rwsem_release(&sem->dep_map, 1, _RET_IP_);
+	rwsem_release(&sem->dep_map, _RET_IP_);
 	__up_write(sem);
 }
 EXPORT_SYMBOL(up_write);
@@ -1640,7 +1637,7 @@
 	rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_);
 
 	if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_killable)) {
-		rwsem_release(&sem->dep_map, 1, _RET_IP_);
+		rwsem_release(&sem->dep_map, _RET_IP_);
 		return -EINTR;
 	}
 
@@ -1679,7 +1676,7 @@
 
 	if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock,
 				  __down_write_killable)) {
-		rwsem_release(&sem->dep_map, 1, _RET_IP_);
+		rwsem_release(&sem->dep_map, _RET_IP_);
 		return -EINTR;
 	}
 
diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h
index 2534ce4..e69de29 100644
--- a/kernel/locking/rwsem.h
+++ b/kernel/locking/rwsem.h
@@ -1,10 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-#ifndef __INTERNAL_RWSEM_H
-#define __INTERNAL_RWSEM_H
-#include <linux/rwsem.h>
-
-extern void __down_read(struct rw_semaphore *sem);
-extern void __up_read(struct rw_semaphore *sem);
-
-#endif /* __INTERNAL_RWSEM_H */
diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c
index d9dd94d..9aa855a 100644
--- a/kernel/locking/semaphore.c
+++ b/kernel/locking/semaphore.c
@@ -119,7 +119,7 @@
  * @sem: the semaphore to be acquired
  *
  * Try to acquire the semaphore atomically.  Returns 0 if the semaphore has
- * been acquired successfully or 1 if it it cannot be acquired.
+ * been acquired successfully or 1 if it cannot be acquired.
  *
  * NOTE: This return value is inverted from both spin_trylock and
  * mutex_trylock!  Be careful about this when converting code.
diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c
index 472dd46..b9d9308 100644
--- a/kernel/locking/spinlock_debug.c
+++ b/kernel/locking/spinlock_debug.c
@@ -14,14 +14,14 @@
 #include <linux/export.h>
 
 void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
-			  struct lock_class_key *key)
+			  struct lock_class_key *key, short inner)
 {
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	/*
 	 * Make sure we are not reinitializing a held lock:
 	 */
 	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
-	lockdep_init_map(&lock->dep_map, name, key, 0);
+	lockdep_init_map_wait(&lock->dep_map, name, key, 0, inner);
 #endif
 	lock->raw_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
 	lock->magic = SPINLOCK_MAGIC;
@@ -39,7 +39,7 @@
 	 * Make sure we are not reinitializing a held lock:
 	 */
 	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
-	lockdep_init_map(&lock->dep_map, name, key, 0);
+	lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_CONFIG);
 #endif
 	lock->raw_lock = (arch_rwlock_t) __ARCH_RW_LOCK_UNLOCKED;
 	lock->magic = RWLOCK_MAGIC;
diff --git a/kernel/module.c b/kernel/module.c
index 59d487b..5f44031 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4,6 +4,9 @@
    Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
 
 */
+
+#define INCLUDE_VERMAGIC
+
 #include <linux/export.h>
 #include <linux/extable.h>
 #include <linux/moduleloader.h>
@@ -15,6 +18,7 @@
 #include <linux/fs.h>
 #include <linux/sysfs.h>
 #include <linux/kernel.h>
+#include <linux/kernel_read_file.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/elf.h>
@@ -1411,7 +1415,7 @@
 	char *imported_namespace;
 
 	namespace = kernel_symbol_namespace(sym);
-	if (namespace) {
+	if (namespace && namespace[0]) {
 		imported_namespace = get_modinfo(info, "import_ns");
 		while (imported_namespace) {
 			if (strcmp(namespace, imported_namespace) == 0)
@@ -1547,7 +1551,7 @@
 struct module_sect_attrs {
 	struct attribute_group grp;
 	unsigned int nsections;
-	struct module_sect_attr attrs[0];
+	struct module_sect_attr attrs[];
 };
 
 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
@@ -1660,7 +1664,7 @@
 struct module_notes_attrs {
 	struct kobject *dir;
 	unsigned int notes;
-	struct bin_attribute attrs[0];
+	struct bin_attribute attrs[];
 };
 
 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
@@ -1993,7 +1997,6 @@
 	mod_sysfs_fini(mod);
 }
 
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
 /*
  * LKM RO/NX protection: protect module's text/ro-data
  * from modification and any data from execution.
@@ -2007,6 +2010,14 @@
  *
  * These values are always page-aligned (as is base)
  */
+
+/*
+ * Since some arches are moving towards PAGE_KERNEL module allocations instead
+ * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
+ * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
+ * whether we are strict.
+ */
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
 static void frob_text(const struct module_layout *layout,
 		      int (*set_memory)(unsigned long start, int num_pages))
 {
@@ -2016,6 +2027,15 @@
 		   layout->text_size >> PAGE_SHIFT);
 }
 
+static void module_enable_x(const struct module *mod)
+{
+	frob_text(&mod->core_layout, set_memory_x);
+	frob_text(&mod->init_layout, set_memory_x);
+}
+#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+static void module_enable_x(const struct module *mod) { }
+#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+
 #ifdef CONFIG_STRICT_MODULE_RWX
 static void frob_rodata(const struct module_layout *layout,
 			int (*set_memory)(unsigned long start, int num_pages))
@@ -2047,20 +2067,7 @@
 		   (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
 }
 
-/* livepatching wants to disable read-only so it can frob module. */
-void module_disable_ro(const struct module *mod)
-{
-	if (!rodata_enabled)
-		return;
-
-	frob_text(&mod->core_layout, set_memory_rw);
-	frob_rodata(&mod->core_layout, set_memory_rw);
-	frob_ro_after_init(&mod->core_layout, set_memory_rw);
-	frob_text(&mod->init_layout, set_memory_rw);
-	frob_rodata(&mod->init_layout, set_memory_rw);
-}
-
-void module_enable_ro(const struct module *mod, bool after_init)
+static void module_enable_ro(const struct module *mod, bool after_init)
 {
 	if (!rodata_enabled)
 		return;
@@ -2086,62 +2093,32 @@
 	frob_writable_data(&mod->init_layout, set_memory_nx);
 }
 
-/* Iterate through all modules and set each module's text as RW */
-void set_all_modules_text_rw(void)
+static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+				       char *secstrings, struct module *mod)
 {
-	struct module *mod;
+	const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
+	int i;
 
-	if (!rodata_enabled)
-		return;
-
-	mutex_lock(&module_mutex);
-	list_for_each_entry_rcu(mod, &modules, list) {
-		if (mod->state == MODULE_STATE_UNFORMED)
-			continue;
-
-		frob_text(&mod->core_layout, set_memory_rw);
-		frob_text(&mod->init_layout, set_memory_rw);
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
+			pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
+				mod->name, secstrings + sechdrs[i].sh_name, i);
+			return -ENOEXEC;
+		}
 	}
-	mutex_unlock(&module_mutex);
+
+	return 0;
 }
 
-/* Iterate through all modules and set each module's text as RO */
-void set_all_modules_text_ro(void)
-{
-	struct module *mod;
-
-	if (!rodata_enabled)
-		return;
-
-	mutex_lock(&module_mutex);
-	list_for_each_entry_rcu(mod, &modules, list) {
-		/*
-		 * Ignore going modules since it's possible that ro
-		 * protection has already been disabled, otherwise we'll
-		 * run into protection faults at module deallocation.
-		 */
-		if (mod->state == MODULE_STATE_UNFORMED ||
-			mod->state == MODULE_STATE_GOING)
-			continue;
-
-		frob_text(&mod->core_layout, set_memory_ro);
-		frob_text(&mod->init_layout, set_memory_ro);
-	}
-	mutex_unlock(&module_mutex);
-}
 #else /* !CONFIG_STRICT_MODULE_RWX */
 static void module_enable_nx(const struct module *mod) { }
-#endif /*  CONFIG_STRICT_MODULE_RWX */
-static void module_enable_x(const struct module *mod)
+static void module_enable_ro(const struct module *mod, bool after_init) {}
+static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+				       char *secstrings, struct module *mod)
 {
-	frob_text(&mod->core_layout, set_memory_x);
-	frob_text(&mod->init_layout, set_memory_x);
+	return 0;
 }
-#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-static void module_enable_nx(const struct module *mod) { }
-static void module_enable_x(const struct module *mod) { }
-#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-
+#endif /*  CONFIG_STRICT_MODULE_RWX */
 
 #ifdef CONFIG_LIVEPATCH
 /*
@@ -2444,11 +2421,13 @@
 		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
 			continue;
 
-		/* Livepatch relocation sections are applied by livepatch */
 		if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
-			continue;
-
-		if (info->sechdrs[i].sh_type == SHT_REL)
+			err = klp_apply_section_relocs(mod, info->sechdrs,
+						       info->secstrings,
+						       info->strtab,
+						       info->index.sym, i,
+						       NULL);
+		else if (info->sechdrs[i].sh_type == SHT_REL)
 			err = apply_relocate(info->sechdrs, info->strtab,
 					     info->index.sym, i, mod);
 		else if (info->sechdrs[i].sh_type == SHT_RELA)
@@ -2510,7 +2489,7 @@
 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
 			    || (s->sh_flags & masks[m][1])
 			    || s->sh_entsize != ~0UL
-			    || strstarts(sname, ".init"))
+			    || module_init_section(sname))
 				continue;
 			s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
 			pr_debug("\t%s\n", sname);
@@ -2543,7 +2522,7 @@
 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
 			    || (s->sh_flags & masks[m][1])
 			    || s->sh_entsize != ~0UL
-			    || !strstarts(sname, ".init"))
+			    || !module_init_section(sname))
 				continue;
 			s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
 					 | INIT_OFFSET_MASK);
@@ -2875,7 +2854,14 @@
 
 void * __weak module_alloc(unsigned long size)
 {
-	return vmalloc_exec(size);
+	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
+			GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
+			NUMA_NO_NODE, __builtin_return_address(0));
+}
+
+bool __weak module_init_section(const char *name)
+{
+	return strstarts(name, ".init");
 }
 
 bool __weak module_exit_section(const char *name)
@@ -3143,22 +3129,27 @@
 	if (info->len < sizeof(*(info->hdr)))
 		return -ENOEXEC;
 
-	err = security_kernel_load_data(LOADING_MODULE);
+	err = security_kernel_load_data(LOADING_MODULE, true);
 	if (err)
 		return err;
 
 	/* Suck in entire file: we'll want most of it. */
-	info->hdr = __vmalloc(info->len,
-			GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
+	info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
 	if (!info->hdr)
 		return -ENOMEM;
 
 	if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
-		vfree(info->hdr);
-		return -EFAULT;
+		err = -EFAULT;
+		goto out;
 	}
 
-	return 0;
+	err = security_kernel_post_load_data((char *)info->hdr, info->len,
+					     LOADING_MODULE, "init_module");
+out:
+	if (err)
+		vfree(info->hdr);
+
+	return err;
 }
 
 static void free_copy(struct load_info *info)
@@ -3342,6 +3333,9 @@
 	}
 #endif
 
+	mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
+						&mod->noinstr_text_size);
+
 #ifdef CONFIG_TRACEPOINTS
 	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
 					     sizeof(*mod->tracepoints_ptrs),
@@ -3377,7 +3371,7 @@
 #endif
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 	/* sechdrs[0].sh_size is always zero */
-	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
+	mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
 					     sizeof(*mod->ftrace_callsites),
 					     &mod->num_ftrace_callsites);
 #endif
@@ -3386,13 +3380,25 @@
 					    sizeof(*mod->ei_funcs),
 					    &mod->num_ei_funcs);
 #endif
+#ifdef CONFIG_KPROBES
+	mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
+						&mod->kprobes_text_size);
+	mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
+						sizeof(unsigned long),
+						&mod->num_kprobe_blacklist);
+#endif
+#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
+	mod->static_call_sites = section_objs(info, ".static_call_sites",
+					      sizeof(*mod->static_call_sites),
+					      &mod->num_static_call_sites);
+#endif
 	mod->extable = section_objs(info, "__ex_table",
 				    sizeof(*mod->extable), &mod->num_exentries);
 
 	if (section_addr(info, "__obsparm"))
 		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
 
-	info->debug = section_objs(info, "__verbose",
+	info->debug = section_objs(info, "__dyndbg",
 				   sizeof(*info->debug), &info->num_debug);
 
 	return 0;
@@ -3504,12 +3510,6 @@
 
 static void flush_module_icache(const struct module *mod)
 {
-	mm_segment_t old_fs;
-
-	/* flush the icache in correct context */
-	old_fs = get_fs();
-	set_fs(KERNEL_DS);
-
 	/*
 	 * Flush the instruction cache, since we've played with text.
 	 * Do it before processing of module parameters, so the module
@@ -3521,8 +3521,6 @@
 				   + mod->init_layout.size);
 	flush_icache_range((unsigned long)mod->core_layout.base,
 			   (unsigned long)mod->core_layout.base + mod->core_layout.size);
-
-	set_fs(old_fs);
 }
 
 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
@@ -3570,6 +3568,11 @@
 	if (err < 0)
 		return ERR_PTR(err);
 
+	err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
+					  info->secstrings, info->mod);
+	if (err < 0)
+		return ERR_PTR(err);
+
 	/* We will do a special allocation for per-cpu sections later. */
 	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
 
@@ -3711,12 +3714,6 @@
 	}
 	freeinit->module_init = mod->init_layout.base;
 
-	/*
-	 * We want to find out whether @mod uses async during init.  Clear
-	 * PF_USED_ASYNC.  async_schedule*() will set it.
-	 */
-	current->flags &= ~PF_USED_ASYNC;
-
 	do_mod_ctors(mod);
 	/* Start the module */
 	if (mod->init != NULL)
@@ -3742,22 +3739,13 @@
 
 	/*
 	 * We need to finish all async code before the module init sequence
-	 * is done.  This has potential to deadlock.  For example, a newly
-	 * detected block device can trigger request_module() of the
-	 * default iosched from async probing task.  Once userland helper
-	 * reaches here, async_synchronize_full() will wait on the async
-	 * task waiting on request_module() and deadlock.
+	 * is done. This has potential to deadlock if synchronous module
+	 * loading is requested from async (which is not allowed!).
 	 *
-	 * This deadlock is avoided by perfomring async_synchronize_full()
-	 * iff module init queued any async jobs.  This isn't a full
-	 * solution as it will deadlock the same if module loading from
-	 * async jobs nests more than once; however, due to the various
-	 * constraints, this hack seems to be the best option for now.
-	 * Please refer to the following thread for details.
-	 *
-	 * http://thread.gmane.org/gmane.linux.kernel/1420814
+	 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
+	 * request_module() from async workers") for more details.
 	 */
-	if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
+	if (!mod->async_probe_requested)
 		async_synchronize_full();
 
 	ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
@@ -3901,9 +3889,13 @@
 	if (err)
 		return err;
 
-	blocking_notifier_call_chain(&module_notify_list,
-				     MODULE_STATE_COMING, mod);
-	return 0;
+	err = blocking_notifier_call_chain_robust(&module_notify_list,
+			MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
+	err = notifier_to_errno(err);
+	if (err)
+		klp_module_going(mod);
+
+	return err;
 }
 
 static int unknown_module_param_cb(char *param, char *val, const char *modname,
@@ -3973,6 +3965,7 @@
 	 */
 	if (blacklisted(info->name)) {
 		err = -EPERM;
+		pr_err("Module %s is blacklisted\n", info->name);
 		goto free_copy;
 	}
 
@@ -4170,8 +4163,7 @@
 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
 {
 	struct load_info info = { };
-	loff_t size;
-	void *hdr;
+	void *hdr = NULL;
 	int err;
 
 	err = may_init_module();
@@ -4184,12 +4176,12 @@
 		      |MODULE_INIT_IGNORE_VERMAGIC))
 		return -EINVAL;
 
-	err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
+	err = kernel_read_file_from_fd(fd, 0, &hdr, INT_MAX, NULL,
 				       READING_MODULE);
-	if (err)
+	if (err < 0)
 		return err;
 	info.hdr = hdr;
-	info.len = size;
+	info.len = err;
 
 	return load_module(&info, uargs, flags);
 }
@@ -4568,16 +4560,17 @@
 	return err;
 }
 
-static const struct file_operations proc_modules_operations = {
-	.open		= modules_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
+static const struct proc_ops modules_proc_ops = {
+	.proc_flags	= PROC_ENTRY_PERMANENT,
+	.proc_open	= modules_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
 };
 
 static int __init proc_modules_init(void)
 {
-	proc_create("modules", 0, NULL, &proc_modules_operations);
+	proc_create("modules", 0, NULL, &modules_proc_ops);
 	return 0;
 }
 module_init(proc_modules_init);
diff --git a/kernel/notifier.c b/kernel/notifier.c
index f6d5ffe..1b019cb 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -36,21 +36,6 @@
 	return 0;
 }
 
-static int notifier_chain_cond_register(struct notifier_block **nl,
-		struct notifier_block *n)
-{
-	while ((*nl) != NULL) {
-		if ((*nl) == n)
-			return 0;
-		if (n->priority > (*nl)->priority)
-			break;
-		nl = &((*nl)->next);
-	}
-	n->next = *nl;
-	rcu_assign_pointer(*nl, n);
-	return 0;
-}
-
 static int notifier_chain_unregister(struct notifier_block **nl,
 		struct notifier_block *n)
 {
@@ -109,6 +94,34 @@
 }
 NOKPROBE_SYMBOL(notifier_call_chain);
 
+/**
+ * notifier_call_chain_robust - Inform the registered notifiers about an event
+ *                              and rollback on error.
+ * @nl:		Pointer to head of the blocking notifier chain
+ * @val_up:	Value passed unmodified to the notifier function
+ * @val_down:	Value passed unmodified to the notifier function when recovering
+ *              from an error on @val_up
+ * @v		Pointer passed unmodified to the notifier function
+ *
+ * NOTE:	It is important the @nl chain doesn't change between the two
+ *		invocations of notifier_call_chain() such that we visit the
+ *		exact same notifier callbacks; this rules out any RCU usage.
+ *
+ * Returns:	the return value of the @val_up call.
+ */
+static int notifier_call_chain_robust(struct notifier_block **nl,
+				     unsigned long val_up, unsigned long val_down,
+				     void *v)
+{
+	int ret, nr = 0;
+
+	ret = notifier_call_chain(nl, val_up, v, -1, &nr);
+	if (ret & NOTIFY_STOP_MASK)
+		notifier_call_chain(nl, val_down, v, nr-1, NULL);
+
+	return ret;
+}
+
 /*
  *	Atomic notifier chain routines.  Registration and unregistration
  *	use a spinlock, and call_chain is synchronized by RCU (no locks).
@@ -159,13 +172,30 @@
 }
 EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
 
+int atomic_notifier_call_chain_robust(struct atomic_notifier_head *nh,
+		unsigned long val_up, unsigned long val_down, void *v)
+{
+	unsigned long flags;
+	int ret;
+
+	/*
+	 * Musn't use RCU; because then the notifier list can
+	 * change between the up and down traversal.
+	 */
+	spin_lock_irqsave(&nh->lock, flags);
+	ret = notifier_call_chain_robust(&nh->head, val_up, val_down, v);
+	spin_unlock_irqrestore(&nh->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(atomic_notifier_call_chain_robust);
+NOKPROBE_SYMBOL(atomic_notifier_call_chain_robust);
+
 /**
- *	__atomic_notifier_call_chain - Call functions in an atomic notifier chain
+ *	atomic_notifier_call_chain - Call functions in an atomic notifier chain
  *	@nh: Pointer to head of the atomic notifier chain
  *	@val: Value passed unmodified to notifier function
  *	@v: Pointer passed unmodified to notifier function
- *	@nr_to_call: See the comment for notifier_call_chain.
- *	@nr_calls: See the comment for notifier_call_chain.
  *
  *	Calls each function in a notifier chain in turn.  The functions
  *	run in an atomic context, so they must not block.
@@ -178,24 +208,16 @@
  *	Otherwise the return value is the return value
  *	of the last notifier function called.
  */
-int __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
-				 unsigned long val, void *v,
-				 int nr_to_call, int *nr_calls)
+int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
+			       unsigned long val, void *v)
 {
 	int ret;
 
 	rcu_read_lock();
-	ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
+	ret = notifier_call_chain(&nh->head, val, v, -1, NULL);
 	rcu_read_unlock();
-	return ret;
-}
-EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain);
-NOKPROBE_SYMBOL(__atomic_notifier_call_chain);
 
-int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
-			       unsigned long val, void *v)
-{
-	return __atomic_notifier_call_chain(nh, val, v, -1, NULL);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(atomic_notifier_call_chain);
 NOKPROBE_SYMBOL(atomic_notifier_call_chain);
@@ -236,29 +258,6 @@
 EXPORT_SYMBOL_GPL(blocking_notifier_chain_register);
 
 /**
- *	blocking_notifier_chain_cond_register - Cond add notifier to a blocking notifier chain
- *	@nh: Pointer to head of the blocking notifier chain
- *	@n: New entry in notifier chain
- *
- *	Adds a notifier to a blocking notifier chain, only if not already
- *	present in the chain.
- *	Must be called in process context.
- *
- *	Currently always returns zero.
- */
-int blocking_notifier_chain_cond_register(struct blocking_notifier_head *nh,
-		struct notifier_block *n)
-{
-	int ret;
-
-	down_write(&nh->rwsem);
-	ret = notifier_chain_cond_register(&nh->head, n);
-	up_write(&nh->rwsem);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(blocking_notifier_chain_cond_register);
-
-/**
  *	blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain
  *	@nh: Pointer to head of the blocking notifier chain
  *	@n: Entry to remove from notifier chain
@@ -288,13 +287,30 @@
 }
 EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister);
 
+int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh,
+		unsigned long val_up, unsigned long val_down, void *v)
+{
+	int ret = NOTIFY_DONE;
+
+	/*
+	 * We check the head outside the lock, but if this access is
+	 * racy then it does not matter what the result of the test
+	 * is, we re-check the list after having taken the lock anyway:
+	 */
+	if (rcu_access_pointer(nh->head)) {
+		down_read(&nh->rwsem);
+		ret = notifier_call_chain_robust(&nh->head, val_up, val_down, v);
+		up_read(&nh->rwsem);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(blocking_notifier_call_chain_robust);
+
 /**
- *	__blocking_notifier_call_chain - Call functions in a blocking notifier chain
+ *	blocking_notifier_call_chain - Call functions in a blocking notifier chain
  *	@nh: Pointer to head of the blocking notifier chain
  *	@val: Value passed unmodified to notifier function
  *	@v: Pointer passed unmodified to notifier function
- *	@nr_to_call: See comment for notifier_call_chain.
- *	@nr_calls: See comment for notifier_call_chain.
  *
  *	Calls each function in a notifier chain in turn.  The functions
  *	run in a process context, so they are allowed to block.
@@ -306,9 +322,8 @@
  *	Otherwise the return value is the return value
  *	of the last notifier function called.
  */
-int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
-				   unsigned long val, void *v,
-				   int nr_to_call, int *nr_calls)
+int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
+		unsigned long val, void *v)
 {
 	int ret = NOTIFY_DONE;
 
@@ -319,19 +334,11 @@
 	 */
 	if (rcu_access_pointer(nh->head)) {
 		down_read(&nh->rwsem);
-		ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
-					nr_calls);
+		ret = notifier_call_chain(&nh->head, val, v, -1, NULL);
 		up_read(&nh->rwsem);
 	}
 	return ret;
 }
-EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain);
-
-int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
-		unsigned long val, void *v)
-{
-	return __blocking_notifier_call_chain(nh, val, v, -1, NULL);
-}
 EXPORT_SYMBOL_GPL(blocking_notifier_call_chain);
 
 /*
@@ -373,13 +380,18 @@
 }
 EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister);
 
+int raw_notifier_call_chain_robust(struct raw_notifier_head *nh,
+		unsigned long val_up, unsigned long val_down, void *v)
+{
+	return notifier_call_chain_robust(&nh->head, val_up, val_down, v);
+}
+EXPORT_SYMBOL_GPL(raw_notifier_call_chain_robust);
+
 /**
- *	__raw_notifier_call_chain - Call functions in a raw notifier chain
+ *	raw_notifier_call_chain - Call functions in a raw notifier chain
  *	@nh: Pointer to head of the raw notifier chain
  *	@val: Value passed unmodified to notifier function
  *	@v: Pointer passed unmodified to notifier function
- *	@nr_to_call: See comment for notifier_call_chain.
- *	@nr_calls: See comment for notifier_call_chain
  *
  *	Calls each function in a notifier chain in turn.  The functions
  *	run in an undefined context.
@@ -392,18 +404,10 @@
  *	Otherwise the return value is the return value
  *	of the last notifier function called.
  */
-int __raw_notifier_call_chain(struct raw_notifier_head *nh,
-			      unsigned long val, void *v,
-			      int nr_to_call, int *nr_calls)
-{
-	return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
-}
-EXPORT_SYMBOL_GPL(__raw_notifier_call_chain);
-
 int raw_notifier_call_chain(struct raw_notifier_head *nh,
 		unsigned long val, void *v)
 {
-	return __raw_notifier_call_chain(nh, val, v, -1, NULL);
+	return notifier_call_chain(&nh->head, val, v, -1, NULL);
 }
 EXPORT_SYMBOL_GPL(raw_notifier_call_chain);
 
@@ -475,12 +479,10 @@
 EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister);
 
 /**
- *	__srcu_notifier_call_chain - Call functions in an SRCU notifier chain
+ *	srcu_notifier_call_chain - Call functions in an SRCU notifier chain
  *	@nh: Pointer to head of the SRCU notifier chain
  *	@val: Value passed unmodified to notifier function
  *	@v: Pointer passed unmodified to notifier function
- *	@nr_to_call: See comment for notifier_call_chain.
- *	@nr_calls: See comment for notifier_call_chain
  *
  *	Calls each function in a notifier chain in turn.  The functions
  *	run in a process context, so they are allowed to block.
@@ -492,25 +494,17 @@
  *	Otherwise the return value is the return value
  *	of the last notifier function called.
  */
-int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
-			       unsigned long val, void *v,
-			       int nr_to_call, int *nr_calls)
+int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
+		unsigned long val, void *v)
 {
 	int ret;
 	int idx;
 
 	idx = srcu_read_lock(&nh->srcu);
-	ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
+	ret = notifier_call_chain(&nh->head, val, v, -1, NULL);
 	srcu_read_unlock(&nh->srcu, idx);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain);
-
-int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
-		unsigned long val, void *v)
-{
-	return __srcu_notifier_call_chain(nh, val, v, -1, NULL);
-}
 EXPORT_SYMBOL_GPL(srcu_notifier_call_chain);
 
 /**
@@ -557,7 +551,6 @@
 
 int register_die_notifier(struct notifier_block *nb)
 {
-	vmalloc_sync_mappings();
 	return atomic_notifier_chain_register(&die_chain, nb);
 }
 EXPORT_SYMBOL_GPL(register_die_notifier);
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index c815f58..12dd41b 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -18,6 +18,9 @@
 #include <linux/pid_namespace.h>
 #include <net/net_namespace.h>
 #include <linux/ipc_namespace.h>
+#include <linux/time_namespace.h>
+#include <linux/fs_struct.h>
+#include <linux/proc_fs.h>
 #include <linux/proc_ns.h>
 #include <linux/file.h>
 #include <linux/syscalls.h>
@@ -40,6 +43,10 @@
 #ifdef CONFIG_CGROUPS
 	.cgroup_ns		= &init_cgroup_ns,
 #endif
+#ifdef CONFIG_TIME_NS
+	.time_ns		= &init_time_ns,
+	.time_ns_for_children	= &init_time_ns,
+#endif
 };
 
 static inline struct nsproxy *create_nsproxy(void)
@@ -106,8 +113,18 @@
 		goto out_net;
 	}
 
+	new_nsp->time_ns_for_children = copy_time_ns(flags, user_ns,
+					tsk->nsproxy->time_ns_for_children);
+	if (IS_ERR(new_nsp->time_ns_for_children)) {
+		err = PTR_ERR(new_nsp->time_ns_for_children);
+		goto out_time;
+	}
+	new_nsp->time_ns = get_time_ns(tsk->nsproxy->time_ns);
+
 	return new_nsp;
 
+out_time:
+	put_net(new_nsp->net_ns);
 out_net:
 	put_cgroup_ns(new_nsp->cgroup_ns);
 out_cgroup:
@@ -136,15 +153,16 @@
 	struct nsproxy *old_ns = tsk->nsproxy;
 	struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
 	struct nsproxy *new_ns;
+	int ret;
 
 	if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
 			      CLONE_NEWPID | CLONE_NEWNET |
-			      CLONE_NEWCGROUP)))) {
-		get_nsproxy(old_ns);
-		return 0;
-	}
-
-	if (!ns_capable(user_ns, CAP_SYS_ADMIN))
+			      CLONE_NEWCGROUP | CLONE_NEWTIME)))) {
+		if (likely(old_ns->time_ns_for_children == old_ns->time_ns)) {
+			get_nsproxy(old_ns);
+			return 0;
+		}
+	} else if (!ns_capable(user_ns, CAP_SYS_ADMIN))
 		return -EPERM;
 
 	/*
@@ -162,6 +180,12 @@
 	if (IS_ERR(new_ns))
 		return  PTR_ERR(new_ns);
 
+	ret = timens_on_fork(new_ns, tsk);
+	if (ret) {
+		free_nsproxy(new_ns);
+		return ret;
+	}
+
 	tsk->nsproxy = new_ns;
 	return 0;
 }
@@ -176,6 +200,10 @@
 		put_ipc_ns(ns->ipc_ns);
 	if (ns->pid_ns_for_children)
 		put_pid_ns(ns->pid_ns_for_children);
+	if (ns->time_ns)
+		put_time_ns(ns->time_ns);
+	if (ns->time_ns_for_children)
+		put_time_ns(ns->time_ns_for_children);
 	put_cgroup_ns(ns->cgroup_ns);
 	put_net(ns->net_ns);
 	kmem_cache_free(nsproxy_cachep, ns);
@@ -192,7 +220,8 @@
 	int err = 0;
 
 	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
-			       CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP)))
+			       CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP |
+			       CLONE_NEWTIME)))
 		return 0;
 
 	user_ns = new_cred ? new_cred->user_ns : current_user_ns();
@@ -230,37 +259,313 @@
 	switch_task_namespaces(p, NULL);
 }
 
-SYSCALL_DEFINE2(setns, int, fd, int, nstype)
+static int check_setns_flags(unsigned long flags)
 {
-	struct task_struct *tsk = current;
-	struct nsproxy *new_nsproxy;
+	if (!flags || (flags & ~(CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
+				 CLONE_NEWNET | CLONE_NEWTIME | CLONE_NEWUSER |
+				 CLONE_NEWPID | CLONE_NEWCGROUP)))
+		return -EINVAL;
+
+#ifndef CONFIG_USER_NS
+	if (flags & CLONE_NEWUSER)
+		return -EINVAL;
+#endif
+#ifndef CONFIG_PID_NS
+	if (flags & CLONE_NEWPID)
+		return -EINVAL;
+#endif
+#ifndef CONFIG_UTS_NS
+	if (flags & CLONE_NEWUTS)
+		return -EINVAL;
+#endif
+#ifndef CONFIG_IPC_NS
+	if (flags & CLONE_NEWIPC)
+		return -EINVAL;
+#endif
+#ifndef CONFIG_CGROUPS
+	if (flags & CLONE_NEWCGROUP)
+		return -EINVAL;
+#endif
+#ifndef CONFIG_NET_NS
+	if (flags & CLONE_NEWNET)
+		return -EINVAL;
+#endif
+#ifndef CONFIG_TIME_NS
+	if (flags & CLONE_NEWTIME)
+		return -EINVAL;
+#endif
+
+	return 0;
+}
+
+static void put_nsset(struct nsset *nsset)
+{
+	unsigned flags = nsset->flags;
+
+	if (flags & CLONE_NEWUSER)
+		put_cred(nsset_cred(nsset));
+	/*
+	 * We only created a temporary copy if we attached to more than just
+	 * the mount namespace.
+	 */
+	if (nsset->fs && (flags & CLONE_NEWNS) && (flags & ~CLONE_NEWNS))
+		free_fs_struct(nsset->fs);
+	if (nsset->nsproxy)
+		free_nsproxy(nsset->nsproxy);
+}
+
+static int prepare_nsset(unsigned flags, struct nsset *nsset)
+{
+	struct task_struct *me = current;
+
+	nsset->nsproxy = create_new_namespaces(0, me, current_user_ns(), me->fs);
+	if (IS_ERR(nsset->nsproxy))
+		return PTR_ERR(nsset->nsproxy);
+
+	if (flags & CLONE_NEWUSER)
+		nsset->cred = prepare_creds();
+	else
+		nsset->cred = current_cred();
+	if (!nsset->cred)
+		goto out;
+
+	/* Only create a temporary copy of fs_struct if we really need to. */
+	if (flags == CLONE_NEWNS) {
+		nsset->fs = me->fs;
+	} else if (flags & CLONE_NEWNS) {
+		nsset->fs = copy_fs_struct(me->fs);
+		if (!nsset->fs)
+			goto out;
+	}
+
+	nsset->flags = flags;
+	return 0;
+
+out:
+	put_nsset(nsset);
+	return -ENOMEM;
+}
+
+static inline int validate_ns(struct nsset *nsset, struct ns_common *ns)
+{
+	return ns->ops->install(nsset, ns);
+}
+
+/*
+ * This is the inverse operation to unshare().
+ * Ordering is equivalent to the standard ordering used everywhere else
+ * during unshare and process creation. The switch to the new set of
+ * namespaces occurs at the point of no return after installation of
+ * all requested namespaces was successful in commit_nsset().
+ */
+static int validate_nsset(struct nsset *nsset, struct pid *pid)
+{
+	int ret = 0;
+	unsigned flags = nsset->flags;
+	struct user_namespace *user_ns = NULL;
+	struct pid_namespace *pid_ns = NULL;
+	struct nsproxy *nsp;
+	struct task_struct *tsk;
+
+	/* Take a "snapshot" of the target task's namespaces. */
+	rcu_read_lock();
+	tsk = pid_task(pid, PIDTYPE_PID);
+	if (!tsk) {
+		rcu_read_unlock();
+		return -ESRCH;
+	}
+
+	if (!ptrace_may_access(tsk, PTRACE_MODE_READ_REALCREDS)) {
+		rcu_read_unlock();
+		return -EPERM;
+	}
+
+	task_lock(tsk);
+	nsp = tsk->nsproxy;
+	if (nsp)
+		get_nsproxy(nsp);
+	task_unlock(tsk);
+	if (!nsp) {
+		rcu_read_unlock();
+		return -ESRCH;
+	}
+
+#ifdef CONFIG_PID_NS
+	if (flags & CLONE_NEWPID) {
+		pid_ns = task_active_pid_ns(tsk);
+		if (unlikely(!pid_ns)) {
+			rcu_read_unlock();
+			ret = -ESRCH;
+			goto out;
+		}
+		get_pid_ns(pid_ns);
+	}
+#endif
+
+#ifdef CONFIG_USER_NS
+	if (flags & CLONE_NEWUSER)
+		user_ns = get_user_ns(__task_cred(tsk)->user_ns);
+#endif
+	rcu_read_unlock();
+
+	/*
+	 * Install requested namespaces. The caller will have
+	 * verified earlier that the requested namespaces are
+	 * supported on this kernel. We don't report errors here
+	 * if a namespace is requested that isn't supported.
+	 */
+#ifdef CONFIG_USER_NS
+	if (flags & CLONE_NEWUSER) {
+		ret = validate_ns(nsset, &user_ns->ns);
+		if (ret)
+			goto out;
+	}
+#endif
+
+	if (flags & CLONE_NEWNS) {
+		ret = validate_ns(nsset, from_mnt_ns(nsp->mnt_ns));
+		if (ret)
+			goto out;
+	}
+
+#ifdef CONFIG_UTS_NS
+	if (flags & CLONE_NEWUTS) {
+		ret = validate_ns(nsset, &nsp->uts_ns->ns);
+		if (ret)
+			goto out;
+	}
+#endif
+
+#ifdef CONFIG_IPC_NS
+	if (flags & CLONE_NEWIPC) {
+		ret = validate_ns(nsset, &nsp->ipc_ns->ns);
+		if (ret)
+			goto out;
+	}
+#endif
+
+#ifdef CONFIG_PID_NS
+	if (flags & CLONE_NEWPID) {
+		ret = validate_ns(nsset, &pid_ns->ns);
+		if (ret)
+			goto out;
+	}
+#endif
+
+#ifdef CONFIG_CGROUPS
+	if (flags & CLONE_NEWCGROUP) {
+		ret = validate_ns(nsset, &nsp->cgroup_ns->ns);
+		if (ret)
+			goto out;
+	}
+#endif
+
+#ifdef CONFIG_NET_NS
+	if (flags & CLONE_NEWNET) {
+		ret = validate_ns(nsset, &nsp->net_ns->ns);
+		if (ret)
+			goto out;
+	}
+#endif
+
+#ifdef CONFIG_TIME_NS
+	if (flags & CLONE_NEWTIME) {
+		ret = validate_ns(nsset, &nsp->time_ns->ns);
+		if (ret)
+			goto out;
+	}
+#endif
+
+out:
+	if (pid_ns)
+		put_pid_ns(pid_ns);
+	if (nsp)
+		put_nsproxy(nsp);
+	put_user_ns(user_ns);
+
+	return ret;
+}
+
+/*
+ * This is the point of no return. There are just a few namespaces
+ * that do some actual work here and it's sufficiently minimal that
+ * a separate ns_common operation seems unnecessary for now.
+ * Unshare is doing the same thing. If we'll end up needing to do
+ * more in a given namespace or a helper here is ultimately not
+ * exported anymore a simple commit handler for each namespace
+ * should be added to ns_common.
+ */
+static void commit_nsset(struct nsset *nsset)
+{
+	unsigned flags = nsset->flags;
+	struct task_struct *me = current;
+
+#ifdef CONFIG_USER_NS
+	if (flags & CLONE_NEWUSER) {
+		/* transfer ownership */
+		commit_creds(nsset_cred(nsset));
+		nsset->cred = NULL;
+	}
+#endif
+
+	/* We only need to commit if we have used a temporary fs_struct. */
+	if ((flags & CLONE_NEWNS) && (flags & ~CLONE_NEWNS)) {
+		set_fs_root(me->fs, &nsset->fs->root);
+		set_fs_pwd(me->fs, &nsset->fs->pwd);
+	}
+
+#ifdef CONFIG_IPC_NS
+	if (flags & CLONE_NEWIPC)
+		exit_sem(me);
+#endif
+
+#ifdef CONFIG_TIME_NS
+	if (flags & CLONE_NEWTIME)
+		timens_commit(me, nsset->nsproxy->time_ns);
+#endif
+
+	/* transfer ownership */
+	switch_task_namespaces(me, nsset->nsproxy);
+	nsset->nsproxy = NULL;
+}
+
+SYSCALL_DEFINE2(setns, int, fd, int, flags)
+{
 	struct file *file;
-	struct ns_common *ns;
-	int err;
+	struct ns_common *ns = NULL;
+	struct nsset nsset = {};
+	int err = 0;
 
-	file = proc_ns_fget(fd);
-	if (IS_ERR(file))
-		return PTR_ERR(file);
+	file = fget(fd);
+	if (!file)
+		return -EBADF;
 
-	err = -EINVAL;
-	ns = get_proc_ns(file_inode(file));
-	if (nstype && (ns->ops->type != nstype))
-		goto out;
-
-	new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
-	if (IS_ERR(new_nsproxy)) {
-		err = PTR_ERR(new_nsproxy);
-		goto out;
+	if (proc_ns_file(file)) {
+		ns = get_proc_ns(file_inode(file));
+		if (flags && (ns->ops->type != flags))
+			err = -EINVAL;
+		flags = ns->ops->type;
+	} else if (!IS_ERR(pidfd_pid(file))) {
+		err = check_setns_flags(flags);
+	} else {
+		err = -EINVAL;
 	}
-
-	err = ns->ops->install(new_nsproxy, ns);
-	if (err) {
-		free_nsproxy(new_nsproxy);
+	if (err)
 		goto out;
-	}
-	switch_task_namespaces(tsk, new_nsproxy);
 
-	perf_event_namespaces(tsk);
+	err = prepare_nsset(flags, &nsset);
+	if (err)
+		goto out;
+
+	if (proc_ns_file(file))
+		err = validate_ns(&nsset, ns);
+	else
+		err = validate_nsset(&nsset, file->private_data);
+	if (!err) {
+		commit_nsset(&nsset);
+		perf_event_namespaces(current);
+	}
+	put_nsset(&nsset);
 out:
 	fput(file);
 	return err;
diff --git a/kernel/padata.c b/kernel/padata.c
index 92a4867..d4d3ba6 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -2,11 +2,14 @@
 /*
  * padata.c - generic interface to process data streams in parallel
  *
- * See Documentation/padata.txt for an api documentation.
+ * See Documentation/core-api/padata.rst for more information.
  *
  * Copyright (C) 2008, 2009 secunet Security Networks AG
  * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
  *
+ * Copyright (c) 2020 Oracle and/or its affiliates.
+ * Author: Daniel Jordan <daniel.m.jordan@oracle.com>
+ *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
@@ -21,6 +24,7 @@
  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <linux/completion.h>
 #include <linux/export.h>
 #include <linux/cpumask.h>
 #include <linux/err.h>
@@ -31,11 +35,30 @@
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/rcupdate.h>
-#include <linux/module.h>
 
-#define MAX_OBJ_NUM 1000
+#define	PADATA_WORK_ONSTACK	1	/* Work's memory is on stack */
+
+struct padata_work {
+	struct work_struct	pw_work;
+	struct list_head	pw_list;  /* padata_free_works linkage */
+	void			*pw_data;
+};
+
+static DEFINE_SPINLOCK(padata_works_lock);
+static struct padata_work *padata_works;
+static LIST_HEAD(padata_free_works);
+
+struct padata_mt_job_state {
+	spinlock_t		lock;
+	struct completion	completion;
+	struct padata_mt_job	*job;
+	int			nworks;
+	int			nworks_fini;
+	unsigned long		chunk_size;
+};
 
 static void padata_free_pd(struct parallel_data *pd);
+static void __init padata_mt_helper(struct work_struct *work);
 
 static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
 {
@@ -59,30 +82,82 @@
 	return padata_index_to_cpu(pd, cpu_index);
 }
 
+static struct padata_work *padata_work_alloc(void)
+{
+	struct padata_work *pw;
+
+	lockdep_assert_held(&padata_works_lock);
+
+	if (list_empty(&padata_free_works))
+		return NULL;	/* No more work items allowed to be queued. */
+
+	pw = list_first_entry(&padata_free_works, struct padata_work, pw_list);
+	list_del(&pw->pw_list);
+	return pw;
+}
+
+static void padata_work_init(struct padata_work *pw, work_func_t work_fn,
+			     void *data, int flags)
+{
+	if (flags & PADATA_WORK_ONSTACK)
+		INIT_WORK_ONSTACK(&pw->pw_work, work_fn);
+	else
+		INIT_WORK(&pw->pw_work, work_fn);
+	pw->pw_data = data;
+}
+
+static int __init padata_work_alloc_mt(int nworks, void *data,
+				       struct list_head *head)
+{
+	int i;
+
+	spin_lock(&padata_works_lock);
+	/* Start at 1 because the current task participates in the job. */
+	for (i = 1; i < nworks; ++i) {
+		struct padata_work *pw = padata_work_alloc();
+
+		if (!pw)
+			break;
+		padata_work_init(pw, padata_mt_helper, data, 0);
+		list_add(&pw->pw_list, head);
+	}
+	spin_unlock(&padata_works_lock);
+
+	return i;
+}
+
+static void padata_work_free(struct padata_work *pw)
+{
+	lockdep_assert_held(&padata_works_lock);
+	list_add(&pw->pw_list, &padata_free_works);
+}
+
+static void __init padata_works_free(struct list_head *works)
+{
+	struct padata_work *cur, *next;
+
+	if (list_empty(works))
+		return;
+
+	spin_lock(&padata_works_lock);
+	list_for_each_entry_safe(cur, next, works, pw_list) {
+		list_del(&cur->pw_list);
+		padata_work_free(cur);
+	}
+	spin_unlock(&padata_works_lock);
+}
+
 static void padata_parallel_worker(struct work_struct *parallel_work)
 {
-	struct padata_parallel_queue *pqueue;
-	LIST_HEAD(local_list);
+	struct padata_work *pw = container_of(parallel_work, struct padata_work,
+					      pw_work);
+	struct padata_priv *padata = pw->pw_data;
 
 	local_bh_disable();
-	pqueue = container_of(parallel_work,
-			      struct padata_parallel_queue, work);
-
-	spin_lock(&pqueue->parallel.lock);
-	list_replace_init(&pqueue->parallel.list, &local_list);
-	spin_unlock(&pqueue->parallel.lock);
-
-	while (!list_empty(&local_list)) {
-		struct padata_priv *padata;
-
-		padata = list_entry(local_list.next,
-				    struct padata_priv, list);
-
-		list_del_init(&padata->list);
-
-		padata->parallel(padata);
-	}
-
+	padata->parallel(padata);
+	spin_lock(&padata_works_lock);
+	padata_work_free(pw);
+	spin_unlock(&padata_works_lock);
 	local_bh_enable();
 }
 
@@ -99,14 +174,16 @@
  * The parallelization callback function will run with BHs off.
  * Note: Every object which is parallelized by padata_do_parallel
  * must be seen by padata_do_serial.
+ *
+ * Return: 0 on success or else negative error code.
  */
 int padata_do_parallel(struct padata_shell *ps,
 		       struct padata_priv *padata, int *cb_cpu)
 {
 	struct padata_instance *pinst = ps->pinst;
-	int i, cpu, cpu_index, target_cpu, err;
-	struct padata_parallel_queue *queue;
+	int i, cpu, cpu_index, err;
 	struct parallel_data *pd;
+	struct padata_work *pw;
 
 	rcu_read_lock_bh();
 
@@ -134,25 +211,26 @@
 	if ((pinst->flags & PADATA_RESET))
 		goto out;
 
-	if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
-		goto out;
-
-	err = 0;
 	atomic_inc(&pd->refcnt);
 	padata->pd = pd;
 	padata->cb_cpu = *cb_cpu;
 
-	padata->seq_nr = atomic_inc_return(&pd->seq_nr);
-	target_cpu = padata_cpu_hash(pd, padata->seq_nr);
-	padata->cpu = target_cpu;
-	queue = per_cpu_ptr(pd->pqueue, target_cpu);
+	spin_lock(&padata_works_lock);
+	padata->seq_nr = ++pd->seq_nr;
+	pw = padata_work_alloc();
+	spin_unlock(&padata_works_lock);
 
-	spin_lock(&queue->parallel.lock);
-	list_add_tail(&padata->list, &queue->parallel.list);
-	spin_unlock(&queue->parallel.lock);
+	rcu_read_unlock_bh();
 
-	queue_work(pinst->parallel_wq, &queue->work);
+	if (pw) {
+		padata_work_init(pw, padata_parallel_worker, padata, 0);
+		queue_work(pinst->parallel_wq, &pw->pw_work);
+	} else {
+		/* Maximum works limit exceeded, run in the current task. */
+		padata->parallel(padata);
+	}
 
+	return 0;
 out:
 	rcu_read_unlock_bh();
 
@@ -163,25 +241,21 @@
 /*
  * padata_find_next - Find the next object that needs serialization.
  *
- * Return values are:
- *
- * A pointer to the control struct of the next object that needs
- * serialization, if present in one of the percpu reorder queues.
- *
- * NULL, if the next object that needs serialization will
- *  be parallel processed by another cpu and is not yet present in
- *  the cpu's reorder queue.
+ * Return:
+ * * A pointer to the control struct of the next object that needs
+ *   serialization, if present in one of the percpu reorder queues.
+ * * NULL, if the next object that needs serialization will
+ *   be parallel processed by another cpu and is not yet present in
+ *   the cpu's reorder queue.
  */
 static struct padata_priv *padata_find_next(struct parallel_data *pd,
 					    bool remove_object)
 {
-	struct padata_parallel_queue *next_queue;
 	struct padata_priv *padata;
 	struct padata_list *reorder;
 	int cpu = pd->cpu;
 
-	next_queue = per_cpu_ptr(pd->pqueue, cpu);
-	reorder = &next_queue->reorder;
+	reorder = per_cpu_ptr(pd->reorder_list, cpu);
 
 	spin_lock(&reorder->lock);
 	if (list_empty(&reorder->list)) {
@@ -202,7 +276,6 @@
 
 	if (remove_object) {
 		list_del_init(&padata->list);
-		atomic_dec(&pd->reorder_objects);
 		++pd->processed;
 		pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false);
 	}
@@ -217,7 +290,7 @@
 	int cb_cpu;
 	struct padata_priv *padata;
 	struct padata_serial_queue *squeue;
-	struct padata_parallel_queue *next_queue;
+	struct padata_list *reorder;
 
 	/*
 	 * We need to ensure that only one cpu can work on dequeueing of
@@ -261,13 +334,12 @@
 	 *
 	 * Ensure reorder queue is read after pd->lock is dropped so we see
 	 * new objects from another task in padata_do_serial.  Pairs with
-	 * smp_mb__after_atomic in padata_do_serial.
+	 * smp_mb in padata_do_serial.
 	 */
 	smp_mb();
 
-	next_queue = per_cpu_ptr(pd->pqueue, pd->cpu);
-	if (!list_empty(&next_queue->reorder.list) &&
-	    padata_find_next(pd, false))
+	reorder = per_cpu_ptr(pd->reorder_list, pd->cpu);
+	if (!list_empty(&reorder->list) && padata_find_next(pd, false))
 		queue_work(pinst->serial_wq, &pd->reorder_work);
 }
 
@@ -326,25 +398,24 @@
 void padata_do_serial(struct padata_priv *padata)
 {
 	struct parallel_data *pd = padata->pd;
-	struct padata_parallel_queue *pqueue = per_cpu_ptr(pd->pqueue,
-							   padata->cpu);
+	int hashed_cpu = padata_cpu_hash(pd, padata->seq_nr);
+	struct padata_list *reorder = per_cpu_ptr(pd->reorder_list, hashed_cpu);
 	struct padata_priv *cur;
 
-	spin_lock(&pqueue->reorder.lock);
+	spin_lock(&reorder->lock);
 	/* Sort in ascending order of sequence number. */
-	list_for_each_entry_reverse(cur, &pqueue->reorder.list, list)
+	list_for_each_entry_reverse(cur, &reorder->list, list)
 		if (cur->seq_nr < padata->seq_nr)
 			break;
 	list_add(&padata->list, &cur->list);
-	atomic_inc(&pd->reorder_objects);
-	spin_unlock(&pqueue->reorder.lock);
+	spin_unlock(&reorder->lock);
 
 	/*
 	 * Ensure the addition to the reorder list is ordered correctly
 	 * with the trylock of pd->lock in padata_reorder.  Pairs with smp_mb
 	 * in padata_reorder.
 	 */
-	smp_mb__after_atomic();
+	smp_mb();
 
 	padata_reorder(pd);
 }
@@ -367,26 +438,96 @@
 	return err;
 }
 
-static int pd_setup_cpumasks(struct parallel_data *pd,
-			     const struct cpumask *pcpumask,
-			     const struct cpumask *cbcpumask)
+static void __init padata_mt_helper(struct work_struct *w)
 {
-	int err = -ENOMEM;
+	struct padata_work *pw = container_of(w, struct padata_work, pw_work);
+	struct padata_mt_job_state *ps = pw->pw_data;
+	struct padata_mt_job *job = ps->job;
+	bool done;
 
-	if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
-		goto out;
-	if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
-		goto free_pcpu_mask;
+	spin_lock(&ps->lock);
 
-	cpumask_copy(pd->cpumask.pcpu, pcpumask);
-	cpumask_copy(pd->cpumask.cbcpu, cbcpumask);
+	while (job->size > 0) {
+		unsigned long start, size, end;
 
-	return 0;
+		start = job->start;
+		/* So end is chunk size aligned if enough work remains. */
+		size = roundup(start + 1, ps->chunk_size) - start;
+		size = min(size, job->size);
+		end = start + size;
 
-free_pcpu_mask:
-	free_cpumask_var(pd->cpumask.pcpu);
-out:
-	return err;
+		job->start = end;
+		job->size -= size;
+
+		spin_unlock(&ps->lock);
+		job->thread_fn(start, end, job->fn_arg);
+		spin_lock(&ps->lock);
+	}
+
+	++ps->nworks_fini;
+	done = (ps->nworks_fini == ps->nworks);
+	spin_unlock(&ps->lock);
+
+	if (done)
+		complete(&ps->completion);
+}
+
+/**
+ * padata_do_multithreaded - run a multithreaded job
+ * @job: Description of the job.
+ *
+ * See the definition of struct padata_mt_job for more details.
+ */
+void __init padata_do_multithreaded(struct padata_mt_job *job)
+{
+	/* In case threads finish at different times. */
+	static const unsigned long load_balance_factor = 4;
+	struct padata_work my_work, *pw;
+	struct padata_mt_job_state ps;
+	LIST_HEAD(works);
+	int nworks;
+
+	if (job->size == 0)
+		return;
+
+	/* Ensure at least one thread when size < min_chunk. */
+	nworks = max(job->size / job->min_chunk, 1ul);
+	nworks = min(nworks, job->max_threads);
+
+	if (nworks == 1) {
+		/* Single thread, no coordination needed, cut to the chase. */
+		job->thread_fn(job->start, job->start + job->size, job->fn_arg);
+		return;
+	}
+
+	spin_lock_init(&ps.lock);
+	init_completion(&ps.completion);
+	ps.job	       = job;
+	ps.nworks      = padata_work_alloc_mt(nworks, &ps, &works);
+	ps.nworks_fini = 0;
+
+	/*
+	 * Chunk size is the amount of work a helper does per call to the
+	 * thread function.  Load balance large jobs between threads by
+	 * increasing the number of chunks, guarantee at least the minimum
+	 * chunk size from the caller, and honor the caller's alignment.
+	 */
+	ps.chunk_size = job->size / (ps.nworks * load_balance_factor);
+	ps.chunk_size = max(ps.chunk_size, job->min_chunk);
+	ps.chunk_size = roundup(ps.chunk_size, job->align);
+
+	list_for_each_entry(pw, &works, pw_list)
+		queue_work(system_unbound_wq, &pw->pw_work);
+
+	/* Use the current thread, which saves starting a workqueue worker. */
+	padata_work_init(&my_work, padata_mt_helper, &ps, PADATA_WORK_ONSTACK);
+	padata_mt_helper(&my_work.pw_work);
+
+	/* Wait for all the helpers to finish. */
+	wait_for_completion(&ps.completion);
+
+	destroy_work_on_stack(&my_work.pw_work);
+	padata_works_free(&works);
 }
 
 static void __padata_list_init(struct padata_list *pd_list)
@@ -409,19 +550,15 @@
 	}
 }
 
-/* Initialize all percpu queues used by parallel workers */
-static void padata_init_pqueues(struct parallel_data *pd)
+/* Initialize per-CPU reorder lists */
+static void padata_init_reorder_list(struct parallel_data *pd)
 {
 	int cpu;
-	struct padata_parallel_queue *pqueue;
+	struct padata_list *list;
 
 	for_each_cpu(cpu, pd->cpumask.pcpu) {
-		pqueue = per_cpu_ptr(pd->pqueue, cpu);
-
-		__padata_list_init(&pqueue->reorder);
-		__padata_list_init(&pqueue->parallel);
-		INIT_WORK(&pqueue->work, padata_parallel_worker);
-		atomic_set(&pqueue->num_obj, 0);
+		list = per_cpu_ptr(pd->reorder_list, cpu);
+		__padata_list_init(list);
 	}
 }
 
@@ -429,33 +566,33 @@
 static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 {
 	struct padata_instance *pinst = ps->pinst;
-	const struct cpumask *cbcpumask;
-	const struct cpumask *pcpumask;
 	struct parallel_data *pd;
 
-	cbcpumask = pinst->rcpumask.cbcpu;
-	pcpumask = pinst->rcpumask.pcpu;
-
 	pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
 	if (!pd)
 		goto err;
 
-	pd->pqueue = alloc_percpu(struct padata_parallel_queue);
-	if (!pd->pqueue)
+	pd->reorder_list = alloc_percpu(struct padata_list);
+	if (!pd->reorder_list)
 		goto err_free_pd;
 
 	pd->squeue = alloc_percpu(struct padata_serial_queue);
 	if (!pd->squeue)
-		goto err_free_pqueue;
+		goto err_free_reorder_list;
 
 	pd->ps = ps;
-	if (pd_setup_cpumasks(pd, pcpumask, cbcpumask))
-		goto err_free_squeue;
 
-	padata_init_pqueues(pd);
+	if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
+		goto err_free_squeue;
+	if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
+		goto err_free_pcpu;
+
+	cpumask_and(pd->cpumask.pcpu, pinst->cpumask.pcpu, cpu_online_mask);
+	cpumask_and(pd->cpumask.cbcpu, pinst->cpumask.cbcpu, cpu_online_mask);
+
+	padata_init_reorder_list(pd);
 	padata_init_squeues(pd);
-	atomic_set(&pd->seq_nr, -1);
-	atomic_set(&pd->reorder_objects, 0);
+	pd->seq_nr = -1;
 	atomic_set(&pd->refcnt, 1);
 	spin_lock_init(&pd->lock);
 	pd->cpu = cpumask_first(pd->cpumask.pcpu);
@@ -463,10 +600,12 @@
 
 	return pd;
 
+err_free_pcpu:
+	free_cpumask_var(pd->cpumask.pcpu);
 err_free_squeue:
 	free_percpu(pd->squeue);
-err_free_pqueue:
-	free_percpu(pd->pqueue);
+err_free_reorder_list:
+	free_percpu(pd->reorder_list);
 err_free_pd:
 	kfree(pd);
 err:
@@ -477,7 +616,7 @@
 {
 	free_cpumask_var(pd->cpumask.pcpu);
 	free_cpumask_var(pd->cpumask.cbcpu);
-	free_percpu(pd->pqueue);
+	free_percpu(pd->reorder_list);
 	free_percpu(pd->squeue);
 	kfree(pd);
 }
@@ -514,24 +653,11 @@
 
 static int padata_replace(struct padata_instance *pinst)
 {
-	int notification_mask = 0;
 	struct padata_shell *ps;
 	int err = 0;
 
 	pinst->flags |= PADATA_RESET;
 
-	cpumask_copy(pinst->omask, pinst->rcpumask.pcpu);
-	cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu,
-		    cpu_online_mask);
-	if (!cpumask_equal(pinst->omask, pinst->rcpumask.pcpu))
-		notification_mask |= PADATA_CPU_PARALLEL;
-
-	cpumask_copy(pinst->omask, pinst->rcpumask.cbcpu);
-	cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu,
-		    cpu_online_mask);
-	if (!cpumask_equal(pinst->omask, pinst->rcpumask.cbcpu))
-		notification_mask |= PADATA_CPU_SERIAL;
-
 	list_for_each_entry(ps, &pinst->pslist, list) {
 		err = padata_replace_one(ps);
 		if (err)
@@ -544,48 +670,11 @@
 		if (atomic_dec_and_test(&ps->opd->refcnt))
 			padata_free_pd(ps->opd);
 
-	if (notification_mask)
-		blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
-					     notification_mask,
-					     &pinst->cpumask);
-
 	pinst->flags &= ~PADATA_RESET;
 
 	return err;
 }
 
-/**
- * padata_register_cpumask_notifier - Registers a notifier that will be called
- *                             if either pcpu or cbcpu or both cpumasks change.
- *
- * @pinst: A poineter to padata instance
- * @nblock: A pointer to notifier block.
- */
-int padata_register_cpumask_notifier(struct padata_instance *pinst,
-				     struct notifier_block *nblock)
-{
-	return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
-						nblock);
-}
-EXPORT_SYMBOL(padata_register_cpumask_notifier);
-
-/**
- * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
- *        registered earlier  using padata_register_cpumask_notifier
- *
- * @pinst: A pointer to data instance.
- * @nlock: A pointer to notifier block.
- */
-int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
-				       struct notifier_block *nblock)
-{
-	return blocking_notifier_chain_unregister(
-		&pinst->cpumask_change_notifier,
-		nblock);
-}
-EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
-
-
 /* If cpumask contains no active cpu, we mark the instance as invalid. */
 static bool padata_validate_cpumask(struct padata_instance *pinst,
 				    const struct cpumask *cpumask)
@@ -629,13 +718,14 @@
 }
 
 /**
- * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
- *                     equivalent to @cpumask.
- *
+ * padata_set_cpumask - Sets specified by @cpumask_type cpumask to the value
+ *                      equivalent to @cpumask.
  * @pinst: padata instance
  * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
  *                to parallel and serial cpumasks respectively.
  * @cpumask: the cpumask to use
+ *
+ * Return: 0 on success or negative error code
  */
 int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 		       cpumask_var_t cpumask)
@@ -669,41 +759,6 @@
 }
 EXPORT_SYMBOL(padata_set_cpumask);
 
-/**
- * padata_start - start the parallel processing
- *
- * @pinst: padata instance to start
- */
-int padata_start(struct padata_instance *pinst)
-{
-	int err = 0;
-
-	mutex_lock(&pinst->lock);
-
-	if (pinst->flags & PADATA_INVALID)
-		err = -EINVAL;
-
-	__padata_start(pinst);
-
-	mutex_unlock(&pinst->lock);
-
-	return err;
-}
-EXPORT_SYMBOL(padata_start);
-
-/**
- * padata_stop - stop the parallel processing
- *
- * @pinst: padata instance to stop
- */
-void padata_stop(struct padata_instance *pinst)
-{
-	mutex_lock(&pinst->lock);
-	__padata_stop(pinst);
-	mutex_unlock(&pinst->lock);
-}
-EXPORT_SYMBOL(padata_stop);
-
 #ifdef CONFIG_HOTPLUG_CPU
 
 static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
@@ -736,41 +791,6 @@
 	return err;
 }
 
- /**
- * padata_remove_cpu - remove a cpu from the one or both(serial and parallel)
- *                     padata cpumasks.
- *
- * @pinst: padata instance
- * @cpu: cpu to remove
- * @mask: bitmask specifying from which cpumask @cpu should be removed
- *        The @mask may be any combination of the following flags:
- *          PADATA_CPU_SERIAL   - serial cpumask
- *          PADATA_CPU_PARALLEL - parallel cpumask
- */
-int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask)
-{
-	int err;
-
-	if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
-		return -EINVAL;
-
-	mutex_lock(&pinst->lock);
-
-	get_online_cpus();
-	if (mask & PADATA_CPU_SERIAL)
-		cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu);
-	if (mask & PADATA_CPU_PARALLEL)
-		cpumask_clear_cpu(cpu, pinst->cpumask.pcpu);
-
-	err = __padata_remove_cpu(pinst, cpu);
-	put_online_cpus();
-
-	mutex_unlock(&pinst->lock);
-
-	return err;
-}
-EXPORT_SYMBOL(padata_remove_cpu);
-
 static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
 {
 	return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) ||
@@ -820,10 +840,6 @@
 
 	WARN_ON(!list_empty(&pinst->pslist));
 
-	padata_stop(pinst);
-	free_cpumask_var(pinst->omask);
-	free_cpumask_var(pinst->rcpumask.cbcpu);
-	free_cpumask_var(pinst->rcpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
 	destroy_workqueue(pinst->serial_wq);
@@ -958,16 +974,12 @@
 };
 
 /**
- * padata_alloc - allocate and initialize a padata instance and specify
- *                cpumasks for serial and parallel workers.
- *
+ * padata_alloc - allocate and initialize a padata instance
  * @name: used to identify the instance
- * @pcpumask: cpumask that will be used for padata parallelization
- * @cbcpumask: cpumask that will be used for padata serialization
+ *
+ * Return: new instance on success, NULL on error
  */
-static struct padata_instance *padata_alloc(const char *name,
-					    const struct cpumask *pcpumask,
-					    const struct cpumask *cbcpumask)
+struct padata_instance *padata_alloc(const char *name)
 {
 	struct padata_instance *pinst;
 
@@ -993,30 +1005,17 @@
 		free_cpumask_var(pinst->cpumask.pcpu);
 		goto err_free_serial_wq;
 	}
-	if (!padata_validate_cpumask(pinst, pcpumask) ||
-	    !padata_validate_cpumask(pinst, cbcpumask))
-		goto err_free_masks;
-
-	if (!alloc_cpumask_var(&pinst->rcpumask.pcpu, GFP_KERNEL))
-		goto err_free_masks;
-	if (!alloc_cpumask_var(&pinst->rcpumask.cbcpu, GFP_KERNEL))
-		goto err_free_rcpumask_pcpu;
-	if (!alloc_cpumask_var(&pinst->omask, GFP_KERNEL))
-		goto err_free_rcpumask_cbcpu;
 
 	INIT_LIST_HEAD(&pinst->pslist);
 
-	cpumask_copy(pinst->cpumask.pcpu, pcpumask);
-	cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
-	cpumask_and(pinst->rcpumask.pcpu, pcpumask, cpu_online_mask);
-	cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask);
+	cpumask_copy(pinst->cpumask.pcpu, cpu_possible_mask);
+	cpumask_copy(pinst->cpumask.cbcpu, cpu_possible_mask);
 
 	if (padata_setup_cpumasks(pinst))
-		goto err_free_omask;
+		goto err_free_masks;
 
-	pinst->flags = 0;
+	__padata_start(pinst);
 
-	BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
 	kobject_init(&pinst->kobj, &padata_attr_type);
 	mutex_init(&pinst->lock);
 
@@ -1031,12 +1030,6 @@
 
 	return pinst;
 
-err_free_omask:
-	free_cpumask_var(pinst->omask);
-err_free_rcpumask_cbcpu:
-	free_cpumask_var(pinst->rcpumask.cbcpu);
-err_free_rcpumask_pcpu:
-	free_cpumask_var(pinst->rcpumask.pcpu);
 err_free_masks:
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
@@ -1050,24 +1043,12 @@
 err:
 	return NULL;
 }
-
-/**
- * padata_alloc_possible - Allocate and initialize padata instance.
- *                         Use the cpu_possible_mask for serial and
- *                         parallel workers.
- *
- * @name: used to identify the instance
- */
-struct padata_instance *padata_alloc_possible(const char *name)
-{
-	return padata_alloc(name, cpu_possible_mask, cpu_possible_mask);
-}
-EXPORT_SYMBOL(padata_alloc_possible);
+EXPORT_SYMBOL(padata_alloc);
 
 /**
  * padata_free - free a padata instance
  *
- * @padata_inst: padata instance to free
+ * @pinst: padata instance to free
  */
 void padata_free(struct padata_instance *pinst)
 {
@@ -1079,6 +1060,8 @@
  * padata_alloc_shell - Allocate and initialize padata shell.
  *
  * @pinst: Parent padata_instance object.
+ *
+ * Return: new shell on success, NULL on error
  */
 struct padata_shell *padata_alloc_shell(struct padata_instance *pinst)
 {
@@ -1119,43 +1102,53 @@
  */
 void padata_free_shell(struct padata_shell *ps)
 {
-	struct padata_instance *pinst = ps->pinst;
+	if (!ps)
+		return;
 
-	mutex_lock(&pinst->lock);
+	mutex_lock(&ps->pinst->lock);
 	list_del(&ps->list);
 	padata_free_pd(rcu_dereference_protected(ps->pd, 1));
-	mutex_unlock(&pinst->lock);
+	mutex_unlock(&ps->pinst->lock);
 
 	kfree(ps);
 }
 EXPORT_SYMBOL(padata_free_shell);
 
-#ifdef CONFIG_HOTPLUG_CPU
-
-static __init int padata_driver_init(void)
+void __init padata_init(void)
 {
+	unsigned int i, possible_cpus;
+#ifdef CONFIG_HOTPLUG_CPU
 	int ret;
 
 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online",
 				      padata_cpu_online, NULL);
 	if (ret < 0)
-		return ret;
+		goto err;
 	hp_online = ret;
 
 	ret = cpuhp_setup_state_multi(CPUHP_PADATA_DEAD, "padata:dead",
 				      NULL, padata_cpu_dead);
-	if (ret < 0) {
-		cpuhp_remove_multi_state(hp_online);
-		return ret;
-	}
-	return 0;
-}
-module_init(padata_driver_init);
-
-static __exit void padata_driver_exit(void)
-{
-	cpuhp_remove_multi_state(CPUHP_PADATA_DEAD);
-	cpuhp_remove_multi_state(hp_online);
-}
-module_exit(padata_driver_exit);
+	if (ret < 0)
+		goto remove_online_state;
 #endif
+
+	possible_cpus = num_possible_cpus();
+	padata_works = kmalloc_array(possible_cpus, sizeof(struct padata_work),
+				     GFP_KERNEL);
+	if (!padata_works)
+		goto remove_dead_state;
+
+	for (i = 0; i < possible_cpus; ++i)
+		list_add(&padata_works[i].pw_list, &padata_free_works);
+
+	return;
+
+remove_dead_state:
+#ifdef CONFIG_HOTPLUG_CPU
+	cpuhp_remove_multi_state(CPUHP_PADATA_DEAD);
+remove_online_state:
+	cpuhp_remove_multi_state(hp_online);
+err:
+#endif
+	pr_warn("padata: initialization failed\n");
+}
diff --git a/kernel/panic.c b/kernel/panic.c
index f470a03..332736a 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -36,6 +36,14 @@
 #define PANIC_TIMER_STEP 100
 #define PANIC_BLINK_SPD 18
 
+#ifdef CONFIG_SMP
+/*
+ * Should we dump all CPUs backtraces in an oops event?
+ * Defaults to 0, can be changed via sysctl.
+ */
+unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
+#endif /* CONFIG_SMP */
+
 int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
 static unsigned long tainted_mask =
 	IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
@@ -44,6 +52,8 @@
 static DEFINE_SPINLOCK(pause_on_oops_lock);
 bool crash_kexec_post_notifiers;
 int panic_on_warn __read_mostly;
+unsigned long panic_on_taint;
+bool panic_on_taint_nousertaint = false;
 
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
@@ -434,6 +444,11 @@
 		pr_warn("Disabling lock debugging due to kernel taint\n");
 
 	set_bit(flag, &tainted_mask);
+
+	if (tainted_mask & panic_on_taint) {
+		panic_on_taint = 0;
+		panic("panic_on_taint set ...");
+	}
 }
 EXPORT_SYMBOL(add_taint);
 
@@ -490,7 +505,7 @@
  * Return true if the calling CPU is allowed to print oops-related info.
  * This is a bit racy..
  */
-int oops_may_print(void)
+bool oops_may_print(void)
 {
 	return pause_on_oops_flag == 0;
 }
@@ -515,6 +530,9 @@
 	/* can't trust the integrity of the kernel anymore: */
 	debug_locks_off();
 	do_oops_enter_exit();
+
+	if (sysctl_oops_all_cpu_backtrace)
+		trigger_all_cpu_backtrace();
 }
 
 /*
@@ -533,7 +551,7 @@
 }
 late_initcall(init_oops_id);
 
-void print_oops_end_marker(void)
+static void print_oops_end_marker(void)
 {
 	init_oops_id();
 	pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
@@ -571,6 +589,11 @@
 	if (args)
 		vprintk(args->fmt, args->args);
 
+	print_modules();
+
+	if (regs)
+		show_regs(regs);
+
 	if (panic_on_warn) {
 		/*
 		 * This thread may hit another WARN() in the panic path.
@@ -582,11 +605,7 @@
 		panic("panic_on_warn set ...\n");
 	}
 
-	print_modules();
-
-	if (regs)
-		show_regs(regs);
-	else
+	if (!regs)
 		dump_stack();
 
 	print_irqtrace_events(current);
@@ -662,26 +681,17 @@
  * Called when gcc's -fstack-protector feature is used, and
  * gcc detects corruption of the on-stack canary value
  */
-__visible void __stack_chk_fail(void)
+__visible noinstr void __stack_chk_fail(void)
 {
+	instrumentation_begin();
 	panic("stack-protector: Kernel stack is corrupted in: %pB",
 		__builtin_return_address(0));
+	instrumentation_end();
 }
 EXPORT_SYMBOL(__stack_chk_fail);
 
 #endif
 
-#ifdef CONFIG_ARCH_HAS_REFCOUNT
-void refcount_error_report(struct pt_regs *regs, const char *err)
-{
-	WARN_RATELIMIT(1, "refcount_t %s at %pB in %s[%d], uid/euid: %u/%u\n",
-		err, (void *)instruction_pointer(regs),
-		current->comm, task_pid_nr(current),
-		from_kuid_munged(&init_user_ns, current_uid()),
-		from_kuid_munged(&init_user_ns, current_euid()));
-}
-#endif
-
 core_param(panic, panic_timeout, int, 0644);
 core_param(panic_print, panic_print, ulong, 0644);
 core_param(pause_on_oops, pause_on_oops, int, 0644);
@@ -697,3 +707,30 @@
 	return 0;
 }
 early_param("oops", oops_setup);
+
+static int __init panic_on_taint_setup(char *s)
+{
+	char *taint_str;
+
+	if (!s)
+		return -EINVAL;
+
+	taint_str = strsep(&s, ",");
+	if (kstrtoul(taint_str, 16, &panic_on_taint))
+		return -EINVAL;
+
+	/* make sure panic_on_taint doesn't hold out-of-range TAINT flags */
+	panic_on_taint &= TAINT_FLAGS_MAX;
+
+	if (!panic_on_taint)
+		return -EINVAL;
+
+	if (s && !strcmp(s, "nousertaint"))
+		panic_on_taint_nousertaint = true;
+
+	pr_info("panic_on_taint: bitmask=0x%lx nousertaint_mode=%sabled\n",
+		panic_on_taint, panic_on_taint_nousertaint ? "en" : "dis");
+
+	return 0;
+}
+early_param("panic_on_taint", panic_on_taint_setup);
diff --git a/kernel/params.c b/kernel/params.c
index 8e56f8b..164d793 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -233,14 +233,15 @@
 	EXPORT_SYMBOL(param_ops_##name)
 
 
-STANDARD_PARAM_DEF(byte,	unsigned char,		"%hhu", kstrtou8);
-STANDARD_PARAM_DEF(short,	short,			"%hi",  kstrtos16);
-STANDARD_PARAM_DEF(ushort,	unsigned short,		"%hu",  kstrtou16);
-STANDARD_PARAM_DEF(int,		int,			"%i",   kstrtoint);
-STANDARD_PARAM_DEF(uint,	unsigned int,		"%u",   kstrtouint);
-STANDARD_PARAM_DEF(long,	long,			"%li",  kstrtol);
-STANDARD_PARAM_DEF(ulong,	unsigned long,		"%lu",  kstrtoul);
-STANDARD_PARAM_DEF(ullong,	unsigned long long,	"%llu", kstrtoull);
+STANDARD_PARAM_DEF(byte,	unsigned char,		"%hhu",		kstrtou8);
+STANDARD_PARAM_DEF(short,	short,			"%hi",		kstrtos16);
+STANDARD_PARAM_DEF(ushort,	unsigned short,		"%hu",		kstrtou16);
+STANDARD_PARAM_DEF(int,		int,			"%i",		kstrtoint);
+STANDARD_PARAM_DEF(uint,	unsigned int,		"%u",		kstrtouint);
+STANDARD_PARAM_DEF(long,	long,			"%li",		kstrtol);
+STANDARD_PARAM_DEF(ulong,	unsigned long,		"%lu",		kstrtoul);
+STANDARD_PARAM_DEF(ullong,	unsigned long long,	"%llu",		kstrtoull);
+STANDARD_PARAM_DEF(hexint,	unsigned int,		"%#08x", 	kstrtouint);
 
 int param_set_charp(const char *val, const struct kernel_param *kp)
 {
@@ -529,7 +530,7 @@
 {
 	unsigned int num;
 	struct attribute_group grp;
-	struct param_attribute attrs[0];
+	struct param_attribute attrs[];
 };
 
 #ifdef CONFIG_SYSFS
diff --git a/kernel/pid.c b/kernel/pid.c
index 0a9f2e4..4856818 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -42,6 +42,8 @@
 #include <linux/sched/signal.h>
 #include <linux/sched/task.h>
 #include <linux/idr.h>
+#include <net/sock.h>
+#include <uapi/linux/pidfd.h>
 
 struct pid init_struct_pid = {
 	.count		= REFCOUNT_INIT(1),
@@ -144,9 +146,6 @@
 			/* Handle a fork failure of the first process */
 			WARN_ON(ns->child_reaper);
 			ns->pid_allocated = 0;
-			/* fall through */
-		case 0:
-			schedule_work(&ns->proc_work);
 			break;
 		}
 
@@ -157,7 +156,8 @@
 	call_rcu(&pid->rcu, delayed_put_pid);
 }
 
-struct pid *alloc_pid(struct pid_namespace *ns)
+struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid,
+		      size_t set_tid_size)
 {
 	struct pid *pid;
 	enum pid_type type;
@@ -166,6 +166,17 @@
 	struct upid *upid;
 	int retval = -ENOMEM;
 
+	/*
+	 * set_tid_size contains the size of the set_tid array. Starting at
+	 * the most nested currently active PID namespace it tells alloc_pid()
+	 * which PID to set for a process in that most nested PID namespace
+	 * up to set_tid_size PID namespaces. It does not have to set the PID
+	 * for a process in all nested PID namespaces but set_tid_size must
+	 * never be greater than the current ns->level + 1.
+	 */
+	if (set_tid_size > ns->level + 1)
+		return ERR_PTR(-EINVAL);
+
 	pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);
 	if (!pid)
 		return ERR_PTR(retval);
@@ -174,24 +185,54 @@
 	pid->level = ns->level;
 
 	for (i = ns->level; i >= 0; i--) {
-		int pid_min = 1;
+		int tid = 0;
+
+		if (set_tid_size) {
+			tid = set_tid[ns->level - i];
+
+			retval = -EINVAL;
+			if (tid < 1 || tid >= pid_max)
+				goto out_free;
+			/*
+			 * Also fail if a PID != 1 is requested and
+			 * no PID 1 exists.
+			 */
+			if (tid != 1 && !tmp->child_reaper)
+				goto out_free;
+			retval = -EPERM;
+			if (!checkpoint_restore_ns_capable(tmp->user_ns))
+				goto out_free;
+			set_tid_size--;
+		}
 
 		idr_preload(GFP_KERNEL);
 		spin_lock_irq(&pidmap_lock);
 
-		/*
-		 * init really needs pid 1, but after reaching the maximum
-		 * wrap back to RESERVED_PIDS
-		 */
-		if (idr_get_cursor(&tmp->idr) > RESERVED_PIDS)
-			pid_min = RESERVED_PIDS;
+		if (tid) {
+			nr = idr_alloc(&tmp->idr, NULL, tid,
+				       tid + 1, GFP_ATOMIC);
+			/*
+			 * If ENOSPC is returned it means that the PID is
+			 * alreay in use. Return EEXIST in that case.
+			 */
+			if (nr == -ENOSPC)
+				nr = -EEXIST;
+		} else {
+			int pid_min = 1;
+			/*
+			 * init really needs pid 1, but after reaching the
+			 * maximum wrap back to RESERVED_PIDS
+			 */
+			if (idr_get_cursor(&tmp->idr) > RESERVED_PIDS)
+				pid_min = RESERVED_PIDS;
 
-		/*
-		 * Store a null pointer so find_pid_ns does not find
-		 * a partially initialized PID (see below).
-		 */
-		nr = idr_alloc_cyclic(&tmp->idr, NULL, pid_min,
-				      pid_max, GFP_ATOMIC);
+			/*
+			 * Store a null pointer so find_pid_ns does not find
+			 * a partially initialized PID (see below).
+			 */
+			nr = idr_alloc_cyclic(&tmp->idr, NULL, pid_min,
+					      pid_max, GFP_ATOMIC);
+		}
 		spin_unlock_irq(&pidmap_lock);
 		idr_preload_end();
 
@@ -205,17 +246,24 @@
 		tmp = tmp->parent;
 	}
 
-	if (unlikely(is_child_reaper(pid))) {
-		if (pid_ns_prepare_proc(ns))
-			goto out_free;
-	}
+	/*
+	 * ENOMEM is not the most obvious choice especially for the case
+	 * where the child subreaper has already exited and the pid
+	 * namespace denies the creation of any new processes. But ENOMEM
+	 * is what we have exposed to userspace for a long time and it is
+	 * documented behavior for pid namespaces. So we can't easily
+	 * change it even if there were an error code better suited.
+	 */
+	retval = -ENOMEM;
 
 	get_pid_ns(ns);
 	refcount_set(&pid->count, 1);
+	spin_lock_init(&pid->lock);
 	for (type = 0; type < PIDTYPE_MAX; ++type)
 		INIT_HLIST_HEAD(&pid->tasks[type]);
 
 	init_waitqueue_head(&pid->wait_pidfd);
+	INIT_HLIST_HEAD(&pid->inodes);
 
 	upid = pid->numbers + ns->level;
 	spin_lock_irq(&pidmap_lock);
@@ -299,7 +347,7 @@
 	*pid_ptr = new;
 
 	for (tmp = PIDTYPE_MAX; --tmp >= 0; )
-		if (!hlist_empty(&pid->tasks[tmp]))
+		if (pid_has_task(pid, tmp))
 			return;
 
 	free_pid(pid);
@@ -317,6 +365,25 @@
 	attach_pid(task, type);
 }
 
+void exchange_tids(struct task_struct *left, struct task_struct *right)
+{
+	struct pid *pid1 = left->thread_pid;
+	struct pid *pid2 = right->thread_pid;
+	struct hlist_head *head1 = &pid1->tasks[PIDTYPE_PID];
+	struct hlist_head *head2 = &pid2->tasks[PIDTYPE_PID];
+
+	/* Swap the single entry tid lists */
+	hlists_swap_heads_rcu(head1, head2);
+
+	/* Swap the per task_struct pid */
+	rcu_assign_pointer(left->thread_pid, pid2);
+	rcu_assign_pointer(right->thread_pid, pid1);
+
+	/* Swap the cached value */
+	WRITE_ONCE(left->pid, pid_nr(pid2));
+	WRITE_ONCE(right->pid, pid_nr(pid1));
+}
+
 /* transfer_pid is an optimization of attach_pid(new), detach_pid(old) */
 void transfer_pid(struct task_struct *old, struct task_struct *new,
 			   enum pid_type type)
@@ -430,8 +497,7 @@
 	rcu_read_lock();
 	if (!ns)
 		ns = task_active_pid_ns(current);
-	if (likely(pid_alive(task)))
-		nr = pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns);
+	nr = pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns);
 	rcu_read_unlock();
 
 	return nr;
@@ -454,10 +520,30 @@
 	return idr_get_next(&ns->idr, &nr);
 }
 
+struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)
+{
+	struct fd f;
+	struct pid *pid;
+
+	f = fdget(fd);
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+
+	pid = pidfd_pid(f.file);
+	if (!IS_ERR(pid)) {
+		get_pid(pid);
+		*flags = f.file->f_flags;
+	}
+
+	fdput(f);
+	return pid;
+}
+
 /**
  * pidfd_create() - Create a new pid file descriptor.
  *
- * @pid:  struct pid that the pidfd will reference
+ * @pid:   struct pid that the pidfd will reference
+ * @flags: flags to pass
  *
  * This creates a new pid file descriptor with the O_CLOEXEC flag set.
  *
@@ -467,12 +553,12 @@
  * Return: On success, a cloexec pidfd is returned.
  *         On error, a negative errno number will be returned.
  */
-static int pidfd_create(struct pid *pid)
+static int pidfd_create(struct pid *pid, unsigned int flags)
 {
 	int fd;
 
 	fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid),
-			      O_RDWR | O_CLOEXEC);
+			      flags | O_RDWR | O_CLOEXEC);
 	if (fd < 0)
 		put_pid(pid);
 
@@ -497,10 +583,10 @@
  */
 SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
 {
-	int fd, ret;
+	int fd;
 	struct pid *p;
 
-	if (flags)
+	if (flags & ~PIDFD_NONBLOCK)
 		return -EINVAL;
 
 	if (pid <= 0)
@@ -510,13 +596,11 @@
 	if (!p)
 		return -ESRCH;
 
-	ret = 0;
-	rcu_read_lock();
-	if (!pid_task(p, PIDTYPE_TGID))
-		ret = -EINVAL;
-	rcu_read_unlock();
+	if (pid_has_task(p, PIDTYPE_TGID))
+		fd = pidfd_create(p, flags);
+	else
+		fd = -EINVAL;
 
-	fd = ret ?: pidfd_create(p);
 	put_pid(p);
 	return fd;
 }
@@ -538,3 +622,84 @@
 	init_pid_ns.pid_cachep = KMEM_CACHE(pid,
 			SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT);
 }
+
+static struct file *__pidfd_fget(struct task_struct *task, int fd)
+{
+	struct file *file;
+	int ret;
+
+	ret = down_read_killable(&task->signal->exec_update_lock);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS))
+		file = fget_task(task, fd);
+	else
+		file = ERR_PTR(-EPERM);
+
+	up_read(&task->signal->exec_update_lock);
+
+	return file ?: ERR_PTR(-EBADF);
+}
+
+static int pidfd_getfd(struct pid *pid, int fd)
+{
+	struct task_struct *task;
+	struct file *file;
+	int ret;
+
+	task = get_pid_task(pid, PIDTYPE_PID);
+	if (!task)
+		return -ESRCH;
+
+	file = __pidfd_fget(task, fd);
+	put_task_struct(task);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	ret = receive_fd(file, O_CLOEXEC);
+	fput(file);
+
+	return ret;
+}
+
+/**
+ * sys_pidfd_getfd() - Get a file descriptor from another process
+ *
+ * @pidfd:	the pidfd file descriptor of the process
+ * @fd:		the file descriptor number to get
+ * @flags:	flags on how to get the fd (reserved)
+ *
+ * This syscall gets a copy of a file descriptor from another process
+ * based on the pidfd, and file descriptor number. It requires that
+ * the calling process has the ability to ptrace the process represented
+ * by the pidfd. The process which is having its file descriptor copied
+ * is otherwise unaffected.
+ *
+ * Return: On success, a cloexec file descriptor is returned.
+ *         On error, a negative errno number will be returned.
+ */
+SYSCALL_DEFINE3(pidfd_getfd, int, pidfd, int, fd,
+		unsigned int, flags)
+{
+	struct pid *pid;
+	struct fd f;
+	int ret;
+
+	/* flags is currently unused - make sure it's unset */
+	if (flags)
+		return -EINVAL;
+
+	f = fdget(pidfd);
+	if (!f.file)
+		return -EBADF;
+
+	pid = pidfd_pid(f.file);
+	if (IS_ERR(pid))
+		ret = PTR_ERR(pid);
+	else
+		ret = pidfd_getfd(pid, fd);
+
+	fdput(f);
+	return ret;
+}
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index f264153..ef8733e 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -26,8 +26,6 @@
 
 static DEFINE_MUTEX(pid_caches_mutex);
 static struct kmem_cache *pid_ns_cachep;
-/* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */
-#define MAX_PID_NS_LEVEL 32
 /* Write once array, filled from the beginning. */
 static struct kmem_cache *pid_cache[MAX_PID_NS_LEVEL];
 
@@ -60,12 +58,6 @@
 	return READ_ONCE(*pkc);
 }
 
-static void proc_cleanup_work(struct work_struct *work)
-{
-	struct pid_namespace *ns = container_of(work, struct pid_namespace, proc_work);
-	pid_ns_release_proc(ns);
-}
-
 static struct ucounts *inc_pid_namespaces(struct user_namespace *ns)
 {
 	return inc_ucount(ns, current_euid(), UCOUNT_PID_NAMESPACES);
@@ -117,7 +109,6 @@
 	ns->user_ns = get_user_ns(user_ns);
 	ns->ucounts = ucounts;
 	ns->pid_allocated = PIDNS_ADDING;
-	INIT_WORK(&ns->proc_work, proc_cleanup_work);
 
 	return ns;
 
@@ -234,20 +225,27 @@
 	} while (rc != -ECHILD);
 
 	/*
-	 * kernel_wait4() above can't reap the EXIT_DEAD children but we do not
-	 * really care, we could reparent them to the global init. We could
-	 * exit and reap ->child_reaper even if it is not the last thread in
-	 * this pid_ns, free_pid(pid_allocated == 0) calls proc_cleanup_work(),
-	 * pid_ns can not go away until proc_kill_sb() drops the reference.
+	 * kernel_wait4() misses EXIT_DEAD children, and EXIT_ZOMBIE
+	 * process whose parents processes are outside of the pid
+	 * namespace.  Such processes are created with setns()+fork().
 	 *
-	 * But this ns can also have other tasks injected by setns()+fork().
-	 * Again, ignoring the user visible semantics we do not really need
-	 * to wait until they are all reaped, but they can be reparented to
-	 * us and thus we need to ensure that pid->child_reaper stays valid
-	 * until they all go away. See free_pid()->wake_up_process().
+	 * If those EXIT_ZOMBIE processes are not reaped by their
+	 * parents before their parents exit, they will be reparented
+	 * to pid_ns->child_reaper.  Thus pidns->child_reaper needs to
+	 * stay valid until they all go away.
 	 *
-	 * We rely on ignored SIGCHLD, an injected zombie must be autoreaped
-	 * if reparented.
+	 * The code relies on the pid_ns->child_reaper ignoring
+	 * SIGCHILD to cause those EXIT_ZOMBIE processes to be
+	 * autoreaped if reparented.
+	 *
+	 * Semantically it is also desirable to wait for EXIT_ZOMBIE
+	 * processes before allowing the child_reaper to be reaped, as
+	 * that gives the invariant that when the init process of a
+	 * pid namespace is reaped all of the processes in the pid
+	 * namespace are gone.
+	 *
+	 * Once all of the other tasks are gone from the pid_namespace
+	 * free_pid() will awaken this task.
 	 */
 	for (;;) {
 		set_current_state(TASK_INTERRUPTIBLE);
@@ -266,13 +264,13 @@
 
 #ifdef CONFIG_CHECKPOINT_RESTORE
 static int pid_ns_ctl_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct pid_namespace *pid_ns = task_active_pid_ns(current);
 	struct ctl_table tmp = *table;
 	int ret, next;
 
-	if (write && !ns_capable(pid_ns->user_ns, CAP_SYS_ADMIN))
+	if (write && !checkpoint_restore_ns_capable(pid_ns->user_ns))
 		return -EPERM;
 
 	/*
@@ -381,13 +379,14 @@
 	put_pid_ns(to_pid_ns(ns));
 }
 
-static int pidns_install(struct nsproxy *nsproxy, struct ns_common *ns)
+static int pidns_install(struct nsset *nsset, struct ns_common *ns)
 {
+	struct nsproxy *nsproxy = nsset->nsproxy;
 	struct pid_namespace *active = task_active_pid_ns(current);
 	struct pid_namespace *ancestor, *new = to_pid_ns(ns);
 
 	if (!ns_capable(new->user_ns, CAP_SYS_ADMIN) ||
-	    !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
+	    !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
 		return -EPERM;
 
 	/*
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index d3667b4..a7320f0 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -3,7 +3,7 @@
 	bool "Suspend to RAM and standby"
 	depends on ARCH_SUSPEND_POSSIBLE
 	default y
-	---help---
+	help
 	  Allow the system to enter sleep states in which main memory is
 	  powered and thus its contents are preserved, such as the
 	  suspend-to-RAM state (e.g. the ACPI S3 state).
@@ -27,7 +27,10 @@
 	  Skip the kernel sys_sync() before freezing user processes.
 	  Some systems prefer not to pay this cost on every invocation
 	  of suspend, or they are content with invoking sync() from
-	  user-space before invoking suspend.  Say Y if that's your case.
+	  user-space before invoking suspend.  There's a run-time switch
+	  at '/sys/power/sync_on_suspend' to configure this behaviour.
+	  This setting changes the default for the run-tim switch. Say Y
+	  to change the default to disable the kernel sys_sync().
 
 config HIBERNATE_CALLBACKS
 	bool
@@ -39,7 +42,7 @@
 	select LZO_COMPRESS
 	select LZO_DECOMPRESS
 	select CRC32
-	---help---
+	help
 	  Enable the suspend to disk (STD) functionality, which is usually
 	  called "hibernation" in user interfaces.  STD checkpoints the
 	  system and powers it off; and restores that checkpoint on reboot.
@@ -77,14 +80,23 @@
 
 	  For more information take a look at <file:Documentation/power/swsusp.rst>.
 
-config ARCH_SAVE_PAGE_KEYS
-	bool
+config HIBERNATION_SNAPSHOT_DEV
+	bool "Userspace snapshot device"
+	depends on HIBERNATION
+	default y
+	help
+	  Device used by the uswsusp tools.
+
+	  Say N if no snapshotting from userspace is needed, this also
+	  reduces the attack surface of the kernel.
+
+	  If in doubt, say Y.
 
 config PM_STD_PARTITION
 	string "Default resume partition"
 	depends on HIBERNATION
 	default ""
-	---help---
+	help
 	  The default resume partition is the partition that the suspend-
 	  to-disk implementation will look for a suspended disk image. 
 
@@ -119,7 +131,7 @@
 	def_bool y
 	depends on PM_SLEEP_SMP
 	depends on ARCH_SUSPEND_NONZERO_CPU
-	---help---
+	help
 	If an arch can suspend (for suspend, hibernate, kexec, etc) on a
 	non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This
 	will allow nohz_full mask to include CPU0.
@@ -128,7 +140,7 @@
 	bool "Opportunistic sleep"
 	depends on PM_SLEEP
 	default n
-	---help---
+	help
 	Allow the kernel to trigger a system transition into a global sleep
 	state automatically whenever there are no active wakeup sources.
 
@@ -136,7 +148,7 @@
 	bool "User space wakeup sources interface"
 	depends on PM_SLEEP
 	default n
-	---help---
+	help
 	Allow user space to create, activate and deactivate wakeup source
 	objects with the help of a sysfs-based interface.
 
@@ -153,7 +165,7 @@
 
 config PM
 	bool "Device power management core functionality"
-	---help---
+	help
 	  Enable functionality allowing I/O devices to be put into energy-saving
 	  (low power) states, for example after a specified period of inactivity
 	  (autosuspended), and woken up in response to a hardware-generated
@@ -167,7 +179,7 @@
 config PM_DEBUG
 	bool "Power Management Debug Support"
 	depends on PM
-	---help---
+	help
 	This option enables various debugging support in the Power Management
 	code. This is helpful when debugging and reporting PM bugs, like
 	suspend support.
@@ -175,7 +187,7 @@
 config PM_ADVANCED_DEBUG
 	bool "Extra PM attributes in sysfs for low-level debugging/testing"
 	depends on PM_DEBUG
-	---help---
+	help
 	Add extra sysfs attributes allowing one to access some Power Management
 	fields of device objects from user space.  If you are not a kernel
 	developer interested in debugging/testing Power Management, say "no".
@@ -183,7 +195,7 @@
 config PM_TEST_SUSPEND
 	bool "Test suspend/resume and wakealarm during bootup"
 	depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
-	---help---
+	help
 	This option will let you suspend your machine during bootup, and
 	make it wake up a few seconds later using an RTC wakeup alarm.
 	Enable this with a kernel parameter like "test_suspend=mem".
@@ -198,7 +210,7 @@
 config DPM_WATCHDOG
 	bool "Device suspend/resume watchdog"
 	depends on PM_DEBUG && PSTORE && EXPERT
-	---help---
+	help
 	  Sets up a watchdog timer to capture drivers that are
 	  locked up attempting to suspend/resume a device.
 	  A detected lockup causes system panic with message
@@ -231,7 +243,7 @@
 	depends on PM_SLEEP_DEBUG
 	depends on X86
 	select PM_TRACE
-	---help---
+	help
 	This enables some cheesy code to save the last PM event point in the
 	RTC across reboots, so that you can debug a machine that just hangs
 	during suspend (or more commonly, during resume).
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index e7e47d9..5899260 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -10,7 +10,8 @@
 obj-$(CONFIG_FREEZER)		+= process.o
 obj-$(CONFIG_SUSPEND)		+= suspend.o
 obj-$(CONFIG_PM_TEST_SUSPEND)	+= suspend_test.o
-obj-$(CONFIG_HIBERNATION)	+= hibernate.o snapshot.o swap.o user.o
+obj-$(CONFIG_HIBERNATION)	+= hibernate.o snapshot.o swap.o
+obj-$(CONFIG_HIBERNATION_SNAPSHOT_DEV) += user.o
 obj-$(CONFIG_PM_AUTOSLEEP)	+= autosleep.o
 obj-$(CONFIG_PM_WAKELOCKS)	+= wakelock.o
 
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
index 7ef35eb..119b929 100644
--- a/kernel/power/energy_model.c
+++ b/kernel/power/energy_model.c
@@ -1,9 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Energy Model of CPUs
+ * Energy Model of devices
  *
- * Copyright (c) 2018, Arm ltd.
+ * Copyright (c) 2018-2020, Arm ltd.
  * Written by: Quentin Perret, Arm ltd.
+ * Improvements provided by: Lukasz Luba, Arm ltd.
  */
 
 #define pr_fmt(fmt) "energy_model: " fmt
@@ -15,30 +16,32 @@
 #include <linux/sched/topology.h>
 #include <linux/slab.h>
 
-/* Mapping of each CPU to the performance domain to which it belongs. */
-static DEFINE_PER_CPU(struct em_perf_domain *, em_data);
-
 /*
  * Mutex serializing the registrations of performance domains and letting
  * callbacks defined by drivers sleep.
  */
 static DEFINE_MUTEX(em_pd_mutex);
 
+static bool _is_cpu_device(struct device *dev)
+{
+	return (dev->bus == &cpu_subsys);
+}
+
 #ifdef CONFIG_DEBUG_FS
 static struct dentry *rootdir;
 
-static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd)
+static void em_debug_create_ps(struct em_perf_state *ps, struct dentry *pd)
 {
 	struct dentry *d;
 	char name[24];
 
-	snprintf(name, sizeof(name), "cs:%lu", cs->frequency);
+	snprintf(name, sizeof(name), "ps:%lu", ps->frequency);
 
-	/* Create per-cs directory */
+	/* Create per-ps directory */
 	d = debugfs_create_dir(name, pd);
-	debugfs_create_ulong("frequency", 0444, d, &cs->frequency);
-	debugfs_create_ulong("power", 0444, d, &cs->power);
-	debugfs_create_ulong("cost", 0444, d, &cs->cost);
+	debugfs_create_ulong("frequency", 0444, d, &ps->frequency);
+	debugfs_create_ulong("power", 0444, d, &ps->power);
+	debugfs_create_ulong("cost", 0444, d, &ps->cost);
 }
 
 static int em_debug_cpus_show(struct seq_file *s, void *unused)
@@ -49,22 +52,30 @@
 }
 DEFINE_SHOW_ATTRIBUTE(em_debug_cpus);
 
-static void em_debug_create_pd(struct em_perf_domain *pd, int cpu)
+static void em_debug_create_pd(struct device *dev)
 {
 	struct dentry *d;
-	char name[8];
 	int i;
 
-	snprintf(name, sizeof(name), "pd%d", cpu);
-
 	/* Create the directory of the performance domain */
-	d = debugfs_create_dir(name, rootdir);
+	d = debugfs_create_dir(dev_name(dev), rootdir);
 
-	debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops);
+	if (_is_cpu_device(dev))
+		debugfs_create_file("cpus", 0444, d, dev->em_pd->cpus,
+				    &em_debug_cpus_fops);
 
-	/* Create a sub-directory for each capacity state */
-	for (i = 0; i < pd->nr_cap_states; i++)
-		em_debug_create_cs(&pd->table[i], d);
+	/* Create a sub-directory for each performance state */
+	for (i = 0; i < dev->em_pd->nr_perf_states; i++)
+		em_debug_create_ps(&dev->em_pd->table[i], d);
+
+}
+
+static void em_debug_remove_pd(struct device *dev)
+{
+	struct dentry *debug_dir;
+
+	debug_dir = debugfs_lookup(dev_name(dev), rootdir);
+	debugfs_remove_recursive(debug_dir);
 }
 
 static int __init em_debug_init(void)
@@ -76,119 +87,164 @@
 }
 fs_initcall(em_debug_init);
 #else /* CONFIG_DEBUG_FS */
-static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {}
+static void em_debug_create_pd(struct device *dev) {}
+static void em_debug_remove_pd(struct device *dev) {}
 #endif
-static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states,
-						struct em_data_callback *cb)
+
+static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
+				int nr_states, struct em_data_callback *cb)
 {
-	unsigned long opp_eff, prev_opp_eff = ULONG_MAX;
-	unsigned long power, freq, prev_freq = 0;
-	int i, ret, cpu = cpumask_first(span);
-	struct em_cap_state *table;
-	struct em_perf_domain *pd;
+	unsigned long power, freq, prev_freq = 0, prev_cost = ULONG_MAX;
+	struct em_perf_state *table;
+	int i, ret;
 	u64 fmax;
 
-	if (!cb->active_power)
-		return NULL;
-
-	pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL);
-	if (!pd)
-		return NULL;
-
 	table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL);
 	if (!table)
-		goto free_pd;
+		return -ENOMEM;
 
-	/* Build the list of capacity states for this performance domain */
+	/* Build the list of performance states for this performance domain */
 	for (i = 0, freq = 0; i < nr_states; i++, freq++) {
 		/*
 		 * active_power() is a driver callback which ceils 'freq' to
-		 * lowest capacity state of 'cpu' above 'freq' and updates
+		 * lowest performance state of 'dev' above 'freq' and updates
 		 * 'power' and 'freq' accordingly.
 		 */
-		ret = cb->active_power(&power, &freq, cpu);
+		ret = cb->active_power(&power, &freq, dev);
 		if (ret) {
-			pr_err("pd%d: invalid cap. state: %d\n", cpu, ret);
-			goto free_cs_table;
+			dev_err(dev, "EM: invalid perf. state: %d\n",
+				ret);
+			goto free_ps_table;
 		}
 
 		/*
 		 * We expect the driver callback to increase the frequency for
-		 * higher capacity states.
+		 * higher performance states.
 		 */
 		if (freq <= prev_freq) {
-			pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq);
-			goto free_cs_table;
+			dev_err(dev, "EM: non-increasing freq: %lu\n",
+				freq);
+			goto free_ps_table;
 		}
 
 		/*
 		 * The power returned by active_state() is expected to be
 		 * positive, in milli-watts and to fit into 16 bits.
 		 */
-		if (!power || power > EM_CPU_MAX_POWER) {
-			pr_err("pd%d: invalid power: %lu\n", cpu, power);
-			goto free_cs_table;
+		if (!power || power > EM_MAX_POWER) {
+			dev_err(dev, "EM: invalid power: %lu\n",
+				power);
+			goto free_ps_table;
 		}
 
 		table[i].power = power;
 		table[i].frequency = prev_freq = freq;
-
-		/*
-		 * The hertz/watts efficiency ratio should decrease as the
-		 * frequency grows on sane platforms. But this isn't always
-		 * true in practice so warn the user if a higher OPP is more
-		 * power efficient than a lower one.
-		 */
-		opp_eff = freq / power;
-		if (opp_eff >= prev_opp_eff)
-			pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_cap_state %d >= em_cap_state%d\n",
-					cpu, i, i - 1);
-		prev_opp_eff = opp_eff;
 	}
 
-	/* Compute the cost of each capacity_state. */
+	/* Compute the cost of each performance state. */
 	fmax = (u64) table[nr_states - 1].frequency;
-	for (i = 0; i < nr_states; i++) {
+	for (i = nr_states - 1; i >= 0; i--) {
 		unsigned long power_res = em_scale_power(table[i].power);
 
 		table[i].cost = div64_u64(fmax * power_res,
 					  table[i].frequency);
+		if (table[i].cost >= prev_cost) {
+			dev_dbg(dev, "EM: OPP:%lu is inefficient\n",
+				table[i].frequency);
+		} else {
+			prev_cost = table[i].cost;
+		}
 	}
 
 	pd->table = table;
-	pd->nr_cap_states = nr_states;
-	cpumask_copy(to_cpumask(pd->cpus), span);
+	pd->nr_perf_states = nr_states;
 
-	em_debug_create_pd(pd, cpu);
+	return 0;
 
-	return pd;
-
-free_cs_table:
+free_ps_table:
 	kfree(table);
-free_pd:
-	kfree(pd);
-
-	return NULL;
+	return -EINVAL;
 }
 
+static int em_create_pd(struct device *dev, int nr_states,
+			struct em_data_callback *cb, cpumask_t *cpus)
+{
+	struct em_perf_domain *pd;
+	struct device *cpu_dev;
+	int cpu, ret;
+
+	if (_is_cpu_device(dev)) {
+		pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL);
+		if (!pd)
+			return -ENOMEM;
+
+		cpumask_copy(em_span_cpus(pd), cpus);
+	} else {
+		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+		if (!pd)
+			return -ENOMEM;
+	}
+
+	ret = em_create_perf_table(dev, pd, nr_states, cb);
+	if (ret) {
+		kfree(pd);
+		return ret;
+	}
+
+	if (_is_cpu_device(dev))
+		for_each_cpu(cpu, cpus) {
+			cpu_dev = get_cpu_device(cpu);
+			cpu_dev->em_pd = pd;
+		}
+
+	dev->em_pd = pd;
+
+	return 0;
+}
+
+/**
+ * em_pd_get() - Return the performance domain for a device
+ * @dev : Device to find the performance domain for
+ *
+ * Returns the performance domain to which @dev belongs, or NULL if it doesn't
+ * exist.
+ */
+struct em_perf_domain *em_pd_get(struct device *dev)
+{
+	if (IS_ERR_OR_NULL(dev))
+		return NULL;
+
+	return dev->em_pd;
+}
+EXPORT_SYMBOL_GPL(em_pd_get);
+
 /**
  * em_cpu_get() - Return the performance domain for a CPU
  * @cpu : CPU to find the performance domain for
  *
- * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't
+ * Returns the performance domain to which @cpu belongs, or NULL if it doesn't
  * exist.
  */
 struct em_perf_domain *em_cpu_get(int cpu)
 {
-	return READ_ONCE(per_cpu(em_data, cpu));
+	struct device *cpu_dev;
+
+	cpu_dev = get_cpu_device(cpu);
+	if (!cpu_dev)
+		return NULL;
+
+	return em_pd_get(cpu_dev);
 }
 EXPORT_SYMBOL_GPL(em_cpu_get);
 
 /**
- * em_register_perf_domain() - Register the Energy Model of a performance domain
- * @span	: Mask of CPUs in the performance domain
- * @nr_states	: Number of capacity states to register
+ * em_dev_register_perf_domain() - Register the Energy Model (EM) for a device
+ * @dev		: Device for which the EM is to register
+ * @nr_states	: Number of performance states to register
  * @cb		: Callback functions providing the data of the Energy Model
+ * @cpus	: Pointer to cpumask_t, which in case of a CPU device is
+ *		obligatory. It can be taken from i.e. 'policy->cpus'. For other
+ *		type of devices this should be set to NULL.
  *
  * Create Energy Model tables for a performance domain using the callbacks
  * defined in cb.
@@ -198,14 +254,13 @@
  *
  * Return 0 on success
  */
-int em_register_perf_domain(cpumask_t *span, unsigned int nr_states,
-						struct em_data_callback *cb)
+int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
+				struct em_data_callback *cb, cpumask_t *cpus)
 {
 	unsigned long cap, prev_cap = 0;
-	struct em_perf_domain *pd;
-	int cpu, ret = 0;
+	int cpu, ret;
 
-	if (!span || !nr_states || !cb)
+	if (!dev || !nr_states || !cb)
 		return -EINVAL;
 
 	/*
@@ -214,47 +269,79 @@
 	 */
 	mutex_lock(&em_pd_mutex);
 
-	for_each_cpu(cpu, span) {
-		/* Make sure we don't register again an existing domain. */
-		if (READ_ONCE(per_cpu(em_data, cpu))) {
-			ret = -EEXIST;
-			goto unlock;
-		}
-
-		/*
-		 * All CPUs of a domain must have the same micro-architecture
-		 * since they all share the same table.
-		 */
-		cap = arch_scale_cpu_capacity(cpu);
-		if (prev_cap && prev_cap != cap) {
-			pr_err("CPUs of %*pbl must have the same capacity\n",
-							cpumask_pr_args(span));
-			ret = -EINVAL;
-			goto unlock;
-		}
-		prev_cap = cap;
-	}
-
-	/* Create the performance domain and add it to the Energy Model. */
-	pd = em_create_pd(span, nr_states, cb);
-	if (!pd) {
-		ret = -EINVAL;
+	if (dev->em_pd) {
+		ret = -EEXIST;
 		goto unlock;
 	}
 
-	for_each_cpu(cpu, span) {
-		/*
-		 * The per-cpu array can be read concurrently from em_cpu_get().
-		 * The barrier enforces the ordering needed to make sure readers
-		 * can only access well formed em_perf_domain structs.
-		 */
-		smp_store_release(per_cpu_ptr(&em_data, cpu), pd);
+	if (_is_cpu_device(dev)) {
+		if (!cpus) {
+			dev_err(dev, "EM: invalid CPU mask\n");
+			ret = -EINVAL;
+			goto unlock;
+		}
+
+		for_each_cpu(cpu, cpus) {
+			if (em_cpu_get(cpu)) {
+				dev_err(dev, "EM: exists for CPU%d\n", cpu);
+				ret = -EEXIST;
+				goto unlock;
+			}
+			/*
+			 * All CPUs of a domain must have the same
+			 * micro-architecture since they all share the same
+			 * table.
+			 */
+			cap = arch_scale_cpu_capacity(cpu);
+			if (prev_cap && prev_cap != cap) {
+				dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n",
+					cpumask_pr_args(cpus));
+
+				ret = -EINVAL;
+				goto unlock;
+			}
+			prev_cap = cap;
+		}
 	}
 
-	pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span));
+	ret = em_create_pd(dev, nr_states, cb, cpus);
+	if (ret)
+		goto unlock;
+
+	em_debug_create_pd(dev);
+	dev_info(dev, "EM: created perf domain\n");
+
 unlock:
 	mutex_unlock(&em_pd_mutex);
-
 	return ret;
 }
-EXPORT_SYMBOL_GPL(em_register_perf_domain);
+EXPORT_SYMBOL_GPL(em_dev_register_perf_domain);
+
+/**
+ * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device
+ * @dev		: Device for which the EM is registered
+ *
+ * Unregister the EM for the specified @dev (but not a CPU device).
+ */
+void em_dev_unregister_perf_domain(struct device *dev)
+{
+	if (IS_ERR_OR_NULL(dev) || !dev->em_pd)
+		return;
+
+	if (_is_cpu_device(dev))
+		return;
+
+	/*
+	 * The mutex separates all register/unregister requests and protects
+	 * from potential clean-up/setup issues in the debugfs directories.
+	 * The debugfs directory name is the same as device's name.
+	 */
+	mutex_lock(&em_pd_mutex);
+	em_debug_remove_pd(dev);
+
+	kfree(dev->em_pd->table);
+	kfree(dev->em_pd);
+	dev->em_pd = NULL;
+	mutex_unlock(&em_pd_mutex);
+}
+EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 69c4cd4..bf640fd 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -9,7 +9,7 @@
  * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
  */
 
-#define pr_fmt(fmt) "PM: " fmt
+#define pr_fmt(fmt) "PM: hibernation: " fmt
 
 #include <linux/export.h>
 #include <linux/suspend.h>
@@ -67,6 +67,18 @@
 
 static const struct platform_hibernation_ops *hibernation_ops;
 
+static atomic_t hibernate_atomic = ATOMIC_INIT(1);
+
+bool hibernate_acquire(void)
+{
+	return atomic_add_unless(&hibernate_atomic, -1, 0);
+}
+
+void hibernate_release(void)
+{
+	atomic_inc(&hibernate_atomic);
+}
+
 bool hibernation_available(void)
 {
 	return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
@@ -106,7 +118,7 @@
 #ifdef CONFIG_PM_DEBUG
 static void hibernation_debug_sleep(void)
 {
-	pr_info("hibernation debug: Waiting for 5 seconds.\n");
+	pr_info("debug: Waiting for 5 seconds.\n");
 	mdelay(5000);
 }
 
@@ -277,7 +289,7 @@
 
 	error = dpm_suspend_end(PMSG_FREEZE);
 	if (error) {
-		pr_err("Some devices failed to power down, aborting hibernation\n");
+		pr_err("Some devices failed to power down, aborting\n");
 		return error;
 	}
 
@@ -295,7 +307,7 @@
 
 	error = syscore_suspend();
 	if (error) {
-		pr_err("Some system devices failed to power down, aborting hibernation\n");
+		pr_err("Some system devices failed to power down, aborting\n");
 		goto Enable_irqs;
 	}
 
@@ -310,7 +322,7 @@
 	restore_processor_state();
 	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 	if (error)
-		pr_err("Error %d creating hibernation image\n", error);
+		pr_err("Error %d creating image\n", error);
 
 	if (!in_suspend) {
 		events_check_enabled = false;
@@ -647,7 +659,7 @@
 		break;
 	case HIBERNATION_PLATFORM:
 		hibernation_platform_enter();
-		/* Fall through */
+		fallthrough;
 	case HIBERNATION_SHUTDOWN:
 		if (pm_power_off)
 			kernel_power_off();
@@ -676,11 +688,11 @@
 		goto Unlock;
 
 	error = swsusp_read(&flags);
-	swsusp_close(FMODE_READ);
+	swsusp_close(FMODE_READ | FMODE_EXCL);
 	if (!error)
-		hibernation_restore(flags & SF_PLATFORM_MODE);
+		error = hibernation_restore(flags & SF_PLATFORM_MODE);
 
-	pr_err("Failed to load hibernation image, recovering.\n");
+	pr_err("Failed to load image, recovering.\n");
 	swsusp_free();
 	free_basic_memory_bitmaps();
  Unlock:
@@ -694,8 +706,8 @@
  */
 int hibernate(void)
 {
-	int error, nr_calls = 0;
 	bool snapshot_test = false;
+	int error;
 
 	if (!hibernation_available()) {
 		pm_pr_dbg("Hibernation not available.\n");
@@ -704,18 +716,16 @@
 
 	lock_system_sleep();
 	/* The snapshot device should not be opened while we're running */
-	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+	if (!hibernate_acquire()) {
 		error = -EBUSY;
 		goto Unlock;
 	}
 
 	pr_info("hibernation entry\n");
 	pm_prepare_console();
-	error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
-	if (error) {
-		nr_calls--;
-		goto Exit;
-	}
+	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
+	if (error)
+		goto Restore;
 
 	ksys_sync_helper();
 
@@ -743,7 +753,7 @@
 		else
 		        flags |= SF_CRC32_MODE;
 
-		pm_pr_dbg("Writing image.\n");
+		pm_pr_dbg("Writing hibernation image.\n");
 		error = swsusp_write(flags);
 		swsusp_free();
 		if (!error) {
@@ -755,7 +765,7 @@
 		in_suspend = 0;
 		pm_restore_gfp_mask();
 	} else {
-		pm_pr_dbg("Image restored successfully.\n");
+		pm_pr_dbg("Hibernation image restored successfully.\n");
 	}
 
  Free_bitmaps:
@@ -773,9 +783,10 @@
 	/* Don't bother checking whether freezer_test_done is true */
 	freezer_test_done = false;
  Exit:
-	__pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
+	pm_notifier_call_chain(PM_POST_HIBERNATION);
+ Restore:
 	pm_restore_console();
-	atomic_inc(&snapshot_device_available);
+	hibernate_release();
  Unlock:
 	unlock_system_sleep();
 	pr_info("hibernation exit\n");
@@ -783,6 +794,102 @@
 	return error;
 }
 
+/**
+ * hibernate_quiet_exec - Execute a function with all devices frozen.
+ * @func: Function to execute.
+ * @data: Data pointer to pass to @func.
+ *
+ * Return the @func return value or an error code if it cannot be executed.
+ */
+int hibernate_quiet_exec(int (*func)(void *data), void *data)
+{
+	int error;
+
+	lock_system_sleep();
+
+	if (!hibernate_acquire()) {
+		error = -EBUSY;
+		goto unlock;
+	}
+
+	pm_prepare_console();
+
+	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
+	if (error)
+		goto restore;
+
+	error = freeze_processes();
+	if (error)
+		goto exit;
+
+	lock_device_hotplug();
+
+	pm_suspend_clear_flags();
+
+	error = platform_begin(true);
+	if (error)
+		goto thaw;
+
+	error = freeze_kernel_threads();
+	if (error)
+		goto thaw;
+
+	error = dpm_prepare(PMSG_FREEZE);
+	if (error)
+		goto dpm_complete;
+
+	suspend_console();
+
+	error = dpm_suspend(PMSG_FREEZE);
+	if (error)
+		goto dpm_resume;
+
+	error = dpm_suspend_end(PMSG_FREEZE);
+	if (error)
+		goto dpm_resume;
+
+	error = platform_pre_snapshot(true);
+	if (error)
+		goto skip;
+
+	error = func(data);
+
+skip:
+	platform_finish(true);
+
+	dpm_resume_start(PMSG_THAW);
+
+dpm_resume:
+	dpm_resume(PMSG_THAW);
+
+	resume_console();
+
+dpm_complete:
+	dpm_complete(PMSG_THAW);
+
+	thaw_kernel_threads();
+
+thaw:
+	platform_end(true);
+
+	unlock_device_hotplug();
+
+	thaw_processes();
+
+exit:
+	pm_notifier_call_chain(PM_POST_HIBERNATION);
+
+restore:
+	pm_restore_console();
+
+	hibernate_release();
+
+unlock:
+	unlock_system_sleep();
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 
 /**
  * software_resume - Resume from a saved hibernation image.
@@ -801,7 +908,7 @@
  */
 static int software_resume(void)
 {
-	int error, nr_calls = 0;
+	int error;
 
 	/*
 	 * If the user said "noresume".. bail out early.
@@ -869,21 +976,19 @@
 		goto Unlock;
 
 	/* The snapshot device should not be opened while we're running */
-	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+	if (!hibernate_acquire()) {
 		error = -EBUSY;
-		swsusp_close(FMODE_READ);
+		swsusp_close(FMODE_READ | FMODE_EXCL);
 		goto Unlock;
 	}
 
 	pr_info("resume from hibernation\n");
 	pm_prepare_console();
-	error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
-	if (error) {
-		nr_calls--;
-		goto Close_Finish;
-	}
+	error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
+	if (error)
+		goto Restore;
 
-	pm_pr_dbg("Preparing processes for restore.\n");
+	pm_pr_dbg("Preparing processes for hibernation restore.\n");
 	error = freeze_processes();
 	if (error)
 		goto Close_Finish;
@@ -897,17 +1002,18 @@
 	error = load_image_and_restore();
 	thaw_processes();
  Finish:
-	__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
+	pm_notifier_call_chain(PM_POST_RESTORE);
+ Restore:
 	pm_restore_console();
-	pr_info("resume from hibernation failed (%d)\n", error);
-	atomic_inc(&snapshot_device_available);
+	pr_info("resume failed (%d)\n", error);
+	hibernate_release();
 	/* For success case, the suspend path will release the lock */
  Unlock:
 	mutex_unlock(&system_transition_mutex);
 	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
 	return error;
  Close_Finish:
-	swsusp_close(FMODE_READ);
+	swsusp_close(FMODE_READ | FMODE_EXCL);
 	goto Finish;
 }
 
@@ -1039,7 +1145,7 @@
 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
 			   char *buf)
 {
-	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
+	return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
 		       MINOR(swsusp_resume_device));
 }
 
@@ -1064,7 +1170,8 @@
 	lock_system_sleep();
 	swsusp_resume_device = res;
 	unlock_system_sleep();
-	pm_pr_dbg("Configured resume from disk to %u\n", swsusp_resume_device);
+	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
+		  swsusp_resume_device);
 	noresume = 0;
 	software_resume();
 	return n;
@@ -1138,7 +1245,7 @@
 
 power_attr(reserved_size);
 
-static struct attribute * g[] = {
+static struct attribute *g[] = {
 	&disk_attr.attr,
 	&resume_offset_attr.attr,
 	&resume_attr.attr,
@@ -1166,7 +1273,7 @@
 	if (noresume)
 		return 1;
 
-	strncpy( resume_file, str, 255 );
+	strncpy(resume_file, str, 255);
 	return 1;
 }
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index e26de7a..d6140ed 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -80,18 +80,18 @@
 }
 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
 
-int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
+int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down)
 {
 	int ret;
 
-	ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
-						nr_to_call, nr_calls);
+	ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, val_down, NULL);
 
 	return notifier_to_errno(ret);
 }
+
 int pm_notifier_call_chain(unsigned long val)
 {
-	return __pm_notifier_call_chain(val, -1, NULL);
+	return blocking_notifier_call_chain(&pm_chain_head, val, NULL);
 }
 
 /* If set, devices may be suspended and resumed asynchronously. */
@@ -190,6 +190,38 @@
 }
 
 power_attr(mem_sleep);
+
+/*
+ * sync_on_suspend: invoke ksys_sync_helper() before suspend.
+ *
+ * show() returns whether ksys_sync_helper() is invoked before suspend.
+ * store() accepts 0 or 1.  0 disables ksys_sync_helper() and 1 enables it.
+ */
+bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
+
+static ssize_t sync_on_suspend_show(struct kobject *kobj,
+				   struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", sync_on_suspend_enabled);
+}
+
+static ssize_t sync_on_suspend_store(struct kobject *kobj,
+				    struct kobj_attribute *attr,
+				    const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	if (val > 1)
+		return -EINVAL;
+
+	sync_on_suspend_enabled = !!val;
+	return n;
+}
+
+power_attr(sync_on_suspend);
 #endif /* CONFIG_SUSPEND */
 
 #ifdef CONFIG_PM_SLEEP_DEBUG
@@ -472,7 +504,10 @@
 					struct kobj_attribute *attr,
 					char *buf)
 {
-	return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
+	if (!pm_wakeup_irq())
+		return -ENODATA;
+
+	return sprintf(buf, "%u\n", pm_wakeup_irq());
 }
 
 power_attr_ro(pm_wakeup_irq);
@@ -503,6 +538,13 @@
 
 power_attr(pm_debug_messages);
 
+static int __init pm_debug_messages_setup(char *str)
+{
+	pm_debug_messages_on = true;
+	return 1;
+}
+__setup("pm_debug_messages", pm_debug_messages_setup);
+
 /**
  * __pm_pr_dbg - Print a suspend debug message to the kernel log.
  * @defer: Whether or not to use printk_deferred() to print the message.
@@ -855,6 +897,7 @@
 	&wakeup_count_attr.attr,
 #ifdef CONFIG_SUSPEND
 	&mem_sleep_attr.attr,
+	&sync_on_suspend_attr.attr,
 #endif
 #ifdef CONFIG_PM_AUTOSLEEP
 	&autosleep_attr.attr,
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 44bee46..24f12d5 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -32,7 +32,7 @@
 	return arch_hibernation_header_save(info, MAX_ARCH_HEADER_SIZE);
 }
 
-static inline char *check_image_kernel(struct swsusp_info *info)
+static inline const char *check_image_kernel(struct swsusp_info *info)
 {
 	return arch_hibernation_header_restore(info) ?
 			"architecture specific data" : NULL;
@@ -154,8 +154,8 @@
 extern void snapshot_write_finalize(struct snapshot_handle *handle);
 extern int snapshot_image_loaded(struct snapshot_handle *handle);
 
-/* If unset, the snapshot device cannot be open. */
-extern atomic_t snapshot_device_available;
+extern bool hibernate_acquire(void);
+extern void hibernate_release(void);
 
 extern sector_t alloc_swapdev_block(int swap);
 extern void free_all_swap_pages(int swap);
@@ -179,7 +179,7 @@
 extern int swsusp_unmark(void);
 #endif
 
-struct timeval;
+struct __kernel_old_timeval;
 /* kernel/power/swsusp.c */
 extern void swsusp_show_speed(ktime_t, ktime_t, unsigned int, char *);
 
@@ -210,8 +210,7 @@
 
 #ifdef CONFIG_PM_SLEEP
 /* kernel/power/main.c */
-extern int __pm_notifier_call_chain(unsigned long val, int nr_to_call,
-				    int *nr_calls);
+extern int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down);
 extern int pm_notifier_call_chain(unsigned long val);
 #endif
 
diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c
index 6d47528..562aa0e 100644
--- a/kernel/power/poweroff.c
+++ b/kernel/power/poweroff.c
@@ -29,7 +29,7 @@
 	schedule_work_on(cpumask_first(cpu_online_mask), &poweroff_work);
 }
 
-static struct sysrq_key_op	sysrq_poweroff_op = {
+static const struct sysrq_key_op	sysrq_poweroff_op = {
 	.handler        = handle_poweroff,
 	.help_msg       = "poweroff(o)",
 	.action_msg     = "Power Off",
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 4b6a54d..b9faa36 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -134,7 +134,7 @@
 	if (!pm_freezing)
 		atomic_inc(&system_freezing_cnt);
 
-	pm_wakeup_clear(true);
+	pm_wakeup_clear(0);
 	pr_info("Freezing user space processes ... ");
 	pm_freezing = true;
 	error = try_to_freeze_tasks(true);
@@ -146,7 +146,7 @@
 	BUG_ON(in_atomic());
 
 	/*
-	 * Now that the whole userspace is frozen we need to disbale
+	 * Now that the whole userspace is frozen we need to disable
 	 * the OOM killer to disallow any further interference with
 	 * killable tasks. There is no guarantee oom victims will
 	 * ever reach a point they go away we have to wait with a timeout.
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index a45cba7..ec7e1e8 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -1,31 +1,21 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * This module exposes the interface to kernel space for specifying
- * QoS dependencies.  It provides infrastructure for registration of:
+ * Power Management Quality of Service (PM QoS) support base.
  *
- * Dependents on a QoS value : register requests
- * Watchers of QoS value : get notified when target QoS value changes
+ * Copyright (C) 2020 Intel Corporation
  *
- * This QoS design is best effort based.  Dependents register their QoS needs.
- * Watchers register to keep track of the current QoS needs of the system.
+ * Authors:
+ *	Mark Gross <mgross@linux.intel.com>
+ *	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  *
- * There are 3 basic classes of QoS parameter: latency, timeout, throughput
- * each have defined units:
- * latency: usec
- * timeout: usec <-- currently not used.
- * throughput: kbs (kilo byte / sec)
+ * Provided here is an interface for specifying PM QoS dependencies.  It allows
+ * entities depending on QoS constraints to register their requests which are
+ * aggregated as appropriate to produce effective constraints (target values)
+ * that can be monitored by entities needing to respect them, either by polling
+ * or through a built-in notification mechanism.
  *
- * There are lists of pm_qos_objects each one wrapping requests, notifiers
- *
- * User mode requests on a QOS parameter register themselves to the
- * subsystem by opening the device node /dev/... and writing there request to
- * the node.  As long as the process holds a file handle open to the node the
- * client continues to be accounted for.  Upon file release the usermode
- * request is removed and a new qos target is computed.  This way when the
- * request that the application has is cleaned up when closes the file
- * pointer or exits the pm_qos_object will get an opportunity to clean up.
- *
- * Mark Gross <mgross@linux.intel.com>
+ * In addition to the basic functionality, more specific interfaces for managing
+ * global CPU latency QoS requests and frequency QoS requests are provided.
  */
 
 /*#define DEBUG*/
@@ -54,56 +44,19 @@
  * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
  * held, taken with _irqsave.  One lock to rule them all
  */
-struct pm_qos_object {
-	struct pm_qos_constraints *constraints;
-	struct miscdevice pm_qos_power_miscdev;
-	char *name;
-};
-
 static DEFINE_SPINLOCK(pm_qos_lock);
 
-static struct pm_qos_object null_pm_qos;
-
-static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
-static struct pm_qos_constraints cpu_dma_constraints = {
-	.list = PLIST_HEAD_INIT(cpu_dma_constraints.list),
-	.target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
-	.default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
-	.no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
-	.type = PM_QOS_MIN,
-	.notifiers = &cpu_dma_lat_notifier,
-};
-static struct pm_qos_object cpu_dma_pm_qos = {
-	.constraints = &cpu_dma_constraints,
-	.name = "cpu_dma_latency",
-};
-
-static struct pm_qos_object *pm_qos_array[] = {
-	&null_pm_qos,
-	&cpu_dma_pm_qos,
-};
-
-static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
-		size_t count, loff_t *f_pos);
-static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
-		size_t count, loff_t *f_pos);
-static int pm_qos_power_open(struct inode *inode, struct file *filp);
-static int pm_qos_power_release(struct inode *inode, struct file *filp);
-
-static const struct file_operations pm_qos_power_fops = {
-	.write = pm_qos_power_write,
-	.read = pm_qos_power_read,
-	.open = pm_qos_power_open,
-	.release = pm_qos_power_release,
-	.llseek = noop_llseek,
-};
-
-/* unlocked internal variant */
-static inline int pm_qos_get_value(struct pm_qos_constraints *c)
+/**
+ * pm_qos_read_value - Return the current effective constraint value.
+ * @c: List of PM QoS constraint requests.
+ */
+s32 pm_qos_read_value(struct pm_qos_constraints *c)
 {
-	struct plist_node *node;
-	int total_value = 0;
+	return READ_ONCE(c->target_value);
+}
 
+static int pm_qos_get_value(struct pm_qos_constraints *c)
+{
 	if (plist_head_empty(&c->list))
 		return c->no_constraint_value;
 
@@ -114,111 +67,42 @@
 	case PM_QOS_MAX:
 		return plist_last(&c->list)->prio;
 
-	case PM_QOS_SUM:
-		plist_for_each(node, &c->list)
-			total_value += node->prio;
-
-		return total_value;
-
 	default:
-		/* runtime check for not using enum */
-		BUG();
+		WARN(1, "Unknown PM QoS type in %s\n", __func__);
 		return PM_QOS_DEFAULT_VALUE;
 	}
 }
 
-s32 pm_qos_read_value(struct pm_qos_constraints *c)
+static void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
 {
-	return c->target_value;
+	WRITE_ONCE(c->target_value, value);
 }
 
-static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
-{
-	c->target_value = value;
-}
-
-static int pm_qos_debug_show(struct seq_file *s, void *unused)
-{
-	struct pm_qos_object *qos = (struct pm_qos_object *)s->private;
-	struct pm_qos_constraints *c;
-	struct pm_qos_request *req;
-	char *type;
-	unsigned long flags;
-	int tot_reqs = 0;
-	int active_reqs = 0;
-
-	if (IS_ERR_OR_NULL(qos)) {
-		pr_err("%s: bad qos param!\n", __func__);
-		return -EINVAL;
-	}
-	c = qos->constraints;
-	if (IS_ERR_OR_NULL(c)) {
-		pr_err("%s: Bad constraints on qos?\n", __func__);
-		return -EINVAL;
-	}
-
-	/* Lock to ensure we have a snapshot */
-	spin_lock_irqsave(&pm_qos_lock, flags);
-	if (plist_head_empty(&c->list)) {
-		seq_puts(s, "Empty!\n");
-		goto out;
-	}
-
-	switch (c->type) {
-	case PM_QOS_MIN:
-		type = "Minimum";
-		break;
-	case PM_QOS_MAX:
-		type = "Maximum";
-		break;
-	case PM_QOS_SUM:
-		type = "Sum";
-		break;
-	default:
-		type = "Unknown";
-	}
-
-	plist_for_each_entry(req, &c->list, node) {
-		char *state = "Default";
-
-		if ((req->node).prio != c->default_value) {
-			active_reqs++;
-			state = "Active";
-		}
-		tot_reqs++;
-		seq_printf(s, "%d: %d: %s\n", tot_reqs,
-			   (req->node).prio, state);
-	}
-
-	seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n",
-		   type, pm_qos_get_value(c), active_reqs, tot_reqs);
-
-out:
-	spin_unlock_irqrestore(&pm_qos_lock, flags);
-	return 0;
-}
-
-DEFINE_SHOW_ATTRIBUTE(pm_qos_debug);
-
 /**
- * pm_qos_update_target - manages the constraints list and calls the notifiers
- *  if needed
- * @c: constraints data struct
- * @node: request to add to the list, to update or to remove
- * @action: action to take on the constraints list
- * @value: value of the request to add or update
+ * pm_qos_update_target - Update a list of PM QoS constraint requests.
+ * @c: List of PM QoS requests.
+ * @node: Target list entry.
+ * @action: Action to carry out (add, update or remove).
+ * @value: New request value for the target list entry.
  *
- * This function returns 1 if the aggregated constraint value has changed, 0
- *  otherwise.
+ * Update the given list of PM QoS constraint requests, @c, by carrying an
+ * @action involving the @node list entry and @value on it.
+ *
+ * The recognized values of @action are PM_QOS_ADD_REQ (store @value in @node
+ * and add it to the list), PM_QOS_UPDATE_REQ (remove @node from the list, store
+ * @value in it and add it to the list again), and PM_QOS_REMOVE_REQ (remove
+ * @node from the list, ignore @value).
+ *
+ * Return: 1 if the aggregate constraint value has changed, 0  otherwise.
  */
 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 			 enum pm_qos_req_action action, int value)
 {
-	unsigned long flags;
 	int prev_value, curr_value, new_value;
-	int ret;
+	unsigned long flags;
 
 	spin_lock_irqsave(&pm_qos_lock, flags);
+
 	prev_value = pm_qos_get_value(c);
 	if (value == PM_QOS_DEFAULT_VALUE)
 		new_value = c->default_value;
@@ -231,12 +115,11 @@
 		break;
 	case PM_QOS_UPDATE_REQ:
 		/*
-		 * to change the list, we atomically remove, reinit
-		 * with new value and add, then see if the extremal
-		 * changed
+		 * To change the list, atomically remove, reinit with new value
+		 * and add, then see if the aggregate has changed.
 		 */
 		plist_del(node, &c->list);
-		/* fall through */
+		fallthrough;
 	case PM_QOS_ADD_REQ:
 		plist_node_init(node, new_value);
 		plist_add(node, &c->list);
@@ -252,16 +135,14 @@
 	spin_unlock_irqrestore(&pm_qos_lock, flags);
 
 	trace_pm_qos_update_target(action, prev_value, curr_value);
-	if (prev_value != curr_value) {
-		ret = 1;
-		if (c->notifiers)
-			blocking_notifier_call_chain(c->notifiers,
-						     (unsigned long)curr_value,
-						     NULL);
-	} else {
-		ret = 0;
-	}
-	return ret;
+
+	if (prev_value == curr_value)
+		return 0;
+
+	if (c->notifiers)
+		blocking_notifier_call_chain(c->notifiers, curr_value, NULL);
+
+	return 1;
 }
 
 /**
@@ -283,14 +164,12 @@
 
 /**
  * pm_qos_update_flags - Update a set of PM QoS flags.
- * @pqf: Set of flags to update.
+ * @pqf: Set of PM QoS flags to update.
  * @req: Request to add to the set, to modify, or to remove from the set.
  * @action: Action to take on the set.
  * @val: Value of the request to add or modify.
  *
- * Update the given set of PM QoS flags and call notifiers if the aggregate
- * value has changed.  Returns 1 if the aggregate constraint value has changed,
- * 0 otherwise.
+ * Return: 1 if the aggregate constraint value has changed, 0 otherwise.
  */
 bool pm_qos_update_flags(struct pm_qos_flags *pqf,
 			 struct pm_qos_flags_request *req,
@@ -309,7 +188,7 @@
 		break;
 	case PM_QOS_UPDATE_REQ:
 		pm_qos_flags_remove_req(pqf, req);
-		/* fall through */
+		fallthrough;
 	case PM_QOS_ADD_REQ:
 		req->flags = val;
 		INIT_LIST_HEAD(&req->node);
@@ -326,288 +205,180 @@
 	spin_unlock_irqrestore(&pm_qos_lock, irqflags);
 
 	trace_pm_qos_update_flags(action, prev_value, curr_value);
+
 	return prev_value != curr_value;
 }
 
+#ifdef CONFIG_CPU_IDLE
+/* Definitions related to the CPU latency QoS. */
+
+static struct pm_qos_constraints cpu_latency_constraints = {
+	.list = PLIST_HEAD_INIT(cpu_latency_constraints.list),
+	.target_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.default_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.no_constraint_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.type = PM_QOS_MIN,
+};
+
 /**
- * pm_qos_request - returns current system wide qos expectation
- * @pm_qos_class: identification of which qos value is requested
- *
- * This function returns the current target value.
+ * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit.
  */
-int pm_qos_request(int pm_qos_class)
+s32 cpu_latency_qos_limit(void)
 {
-	return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints);
-}
-EXPORT_SYMBOL_GPL(pm_qos_request);
-
-int pm_qos_request_active(struct pm_qos_request *req)
-{
-	return req->pm_qos_class != 0;
-}
-EXPORT_SYMBOL_GPL(pm_qos_request_active);
-
-static void __pm_qos_update_request(struct pm_qos_request *req,
-			   s32 new_value)
-{
-	trace_pm_qos_update_request(req->pm_qos_class, new_value);
-
-	if (new_value != req->node.prio)
-		pm_qos_update_target(
-			pm_qos_array[req->pm_qos_class]->constraints,
-			&req->node, PM_QOS_UPDATE_REQ, new_value);
+	return pm_qos_read_value(&cpu_latency_constraints);
 }
 
 /**
- * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
- * @work: work struct for the delayed work (timeout)
+ * cpu_latency_qos_request_active - Check the given PM QoS request.
+ * @req: PM QoS request to check.
  *
- * This cancels the timeout request by falling back to the default at timeout.
+ * Return: 'true' if @req has been added to the CPU latency QoS list, 'false'
+ * otherwise.
  */
-static void pm_qos_work_fn(struct work_struct *work)
+bool cpu_latency_qos_request_active(struct pm_qos_request *req)
 {
-	struct pm_qos_request *req = container_of(to_delayed_work(work),
-						  struct pm_qos_request,
-						  work);
+	return req->qos == &cpu_latency_constraints;
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_request_active);
 
-	__pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
+static void cpu_latency_qos_apply(struct pm_qos_request *req,
+				  enum pm_qos_req_action action, s32 value)
+{
+	int ret = pm_qos_update_target(req->qos, &req->node, action, value);
+	if (ret > 0)
+		wake_up_all_idle_cpus();
 }
 
 /**
- * pm_qos_add_request - inserts new qos request into the list
- * @req: pointer to a preallocated handle
- * @pm_qos_class: identifies which list of qos request to use
- * @value: defines the qos request
+ * cpu_latency_qos_add_request - Add new CPU latency QoS request.
+ * @req: Pointer to a preallocated handle.
+ * @value: Requested constraint value.
  *
- * This function inserts a new entry in the pm_qos_class list of requested qos
- * performance characteristics.  It recomputes the aggregate QoS expectations
- * for the pm_qos_class of parameters and initializes the pm_qos_request
- * handle.  Caller needs to save this handle for later use in updates and
- * removal.
+ * Use @value to initialize the request handle pointed to by @req, insert it as
+ * a new entry to the CPU latency QoS list and recompute the effective QoS
+ * constraint for that list.
+ *
+ * Callers need to save the handle for later use in updates and removal of the
+ * QoS request represented by it.
  */
-
-void pm_qos_add_request(struct pm_qos_request *req,
-			int pm_qos_class, s32 value)
-{
-	if (!req) /*guard against callers passing in null */
-		return;
-
-	if (pm_qos_request_active(req)) {
-		WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n");
-		return;
-	}
-	req->pm_qos_class = pm_qos_class;
-	INIT_DELAYED_WORK(&req->work, pm_qos_work_fn);
-	trace_pm_qos_add_request(pm_qos_class, value);
-	pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints,
-			     &req->node, PM_QOS_ADD_REQ, value);
-}
-EXPORT_SYMBOL_GPL(pm_qos_add_request);
-
-/**
- * pm_qos_update_request - modifies an existing qos request
- * @req : handle to list element holding a pm_qos request to use
- * @value: defines the qos request
- *
- * Updates an existing qos request for the pm_qos_class of parameters along
- * with updating the target pm_qos_class value.
- *
- * Attempts are made to make this code callable on hot code paths.
- */
-void pm_qos_update_request(struct pm_qos_request *req,
-			   s32 new_value)
-{
-	if (!req) /*guard against callers passing in null */
-		return;
-
-	if (!pm_qos_request_active(req)) {
-		WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n");
-		return;
-	}
-
-	cancel_delayed_work_sync(&req->work);
-	__pm_qos_update_request(req, new_value);
-}
-EXPORT_SYMBOL_GPL(pm_qos_update_request);
-
-/**
- * pm_qos_update_request_timeout - modifies an existing qos request temporarily.
- * @req : handle to list element holding a pm_qos request to use
- * @new_value: defines the temporal qos request
- * @timeout_us: the effective duration of this qos request in usecs.
- *
- * After timeout_us, this qos request is cancelled automatically.
- */
-void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
-				   unsigned long timeout_us)
+void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value)
 {
 	if (!req)
 		return;
-	if (WARN(!pm_qos_request_active(req),
-		 "%s called for unknown object.", __func__))
-		return;
 
-	cancel_delayed_work_sync(&req->work);
-
-	trace_pm_qos_update_request_timeout(req->pm_qos_class,
-					    new_value, timeout_us);
-	if (new_value != req->node.prio)
-		pm_qos_update_target(
-			pm_qos_array[req->pm_qos_class]->constraints,
-			&req->node, PM_QOS_UPDATE_REQ, new_value);
-
-	schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us));
-}
-
-/**
- * pm_qos_remove_request - modifies an existing qos request
- * @req: handle to request list element
- *
- * Will remove pm qos request from the list of constraints and
- * recompute the current target value for the pm_qos_class.  Call this
- * on slow code paths.
- */
-void pm_qos_remove_request(struct pm_qos_request *req)
-{
-	if (!req) /*guard against callers passing in null */
-		return;
-		/* silent return to keep pcm code cleaner */
-
-	if (!pm_qos_request_active(req)) {
-		WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n");
+	if (cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for already added request\n", __func__);
 		return;
 	}
 
-	cancel_delayed_work_sync(&req->work);
+	trace_pm_qos_add_request(value);
 
-	trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE);
-	pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
-			     &req->node, PM_QOS_REMOVE_REQ,
-			     PM_QOS_DEFAULT_VALUE);
+	req->qos = &cpu_latency_constraints;
+	cpu_latency_qos_apply(req, PM_QOS_ADD_REQ, value);
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_add_request);
+
+/**
+ * cpu_latency_qos_update_request - Modify existing CPU latency QoS request.
+ * @req : QoS request to update.
+ * @new_value: New requested constraint value.
+ *
+ * Use @new_value to update the QoS request represented by @req in the CPU
+ * latency QoS list along with updating the effective constraint value for that
+ * list.
+ */
+void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value)
+{
+	if (!req)
+		return;
+
+	if (!cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for unknown object\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_update_request(new_value);
+
+	if (new_value == req->node.prio)
+		return;
+
+	cpu_latency_qos_apply(req, PM_QOS_UPDATE_REQ, new_value);
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_update_request);
+
+/**
+ * cpu_latency_qos_remove_request - Remove existing CPU latency QoS request.
+ * @req: QoS request to remove.
+ *
+ * Remove the CPU latency QoS request represented by @req from the CPU latency
+ * QoS list along with updating the effective constraint value for that list.
+ */
+void cpu_latency_qos_remove_request(struct pm_qos_request *req)
+{
+	if (!req)
+		return;
+
+	if (!cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for unknown object\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_remove_request(PM_QOS_DEFAULT_VALUE);
+
+	cpu_latency_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
 	memset(req, 0, sizeof(*req));
 }
-EXPORT_SYMBOL_GPL(pm_qos_remove_request);
+EXPORT_SYMBOL_GPL(cpu_latency_qos_remove_request);
 
-/**
- * pm_qos_add_notifier - sets notification entry for changes to target value
- * @pm_qos_class: identifies which qos target changes should be notified.
- * @notifier: notifier block managed by caller.
- *
- * will register the notifier into a notification chain that gets called
- * upon changes to the pm_qos_class target value.
- */
-int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
-{
-	int retval;
+/* User space interface to the CPU latency QoS via misc device. */
 
-	retval = blocking_notifier_chain_register(
-			pm_qos_array[pm_qos_class]->constraints->notifiers,
-			notifier);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(pm_qos_add_notifier);
-
-/**
- * pm_qos_remove_notifier - deletes notification entry from chain.
- * @pm_qos_class: identifies which qos target changes are notified.
- * @notifier: notifier block to be removed.
- *
- * will remove the notifier from the notification chain that gets called
- * upon changes to the pm_qos_class target value.
- */
-int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
-{
-	int retval;
-
-	retval = blocking_notifier_chain_unregister(
-			pm_qos_array[pm_qos_class]->constraints->notifiers,
-			notifier);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
-
-/* User space interface to PM QoS classes via misc devices */
-static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d)
-{
-	qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
-	qos->pm_qos_power_miscdev.name = qos->name;
-	qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
-
-	debugfs_create_file(qos->name, S_IRUGO, d, (void *)qos,
-			    &pm_qos_debug_fops);
-
-	return misc_register(&qos->pm_qos_power_miscdev);
-}
-
-static int find_pm_qos_object_by_minor(int minor)
-{
-	int pm_qos_class;
-
-	for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY;
-		pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) {
-		if (minor ==
-			pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor)
-			return pm_qos_class;
-	}
-	return -1;
-}
-
-static int pm_qos_power_open(struct inode *inode, struct file *filp)
-{
-	long pm_qos_class;
-
-	pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
-	if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) {
-		struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL);
-		if (!req)
-			return -ENOMEM;
-
-		pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
-		filp->private_data = req;
-
-		return 0;
-	}
-	return -EPERM;
-}
-
-static int pm_qos_power_release(struct inode *inode, struct file *filp)
+static int cpu_latency_qos_open(struct inode *inode, struct file *filp)
 {
 	struct pm_qos_request *req;
 
-	req = filp->private_data;
-	pm_qos_remove_request(req);
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	cpu_latency_qos_add_request(req, PM_QOS_DEFAULT_VALUE);
+	filp->private_data = req;
+
+	return 0;
+}
+
+static int cpu_latency_qos_release(struct inode *inode, struct file *filp)
+{
+	struct pm_qos_request *req = filp->private_data;
+
+	filp->private_data = NULL;
+
+	cpu_latency_qos_remove_request(req);
 	kfree(req);
 
 	return 0;
 }
 
-
-static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
-		size_t count, loff_t *f_pos)
+static ssize_t cpu_latency_qos_read(struct file *filp, char __user *buf,
+				    size_t count, loff_t *f_pos)
 {
-	s32 value;
-	unsigned long flags;
 	struct pm_qos_request *req = filp->private_data;
+	unsigned long flags;
+	s32 value;
 
-	if (!req)
-		return -EINVAL;
-	if (!pm_qos_request_active(req))
+	if (!req || !cpu_latency_qos_request_active(req))
 		return -EINVAL;
 
 	spin_lock_irqsave(&pm_qos_lock, flags);
-	value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints);
+	value = pm_qos_get_value(&cpu_latency_constraints);
 	spin_unlock_irqrestore(&pm_qos_lock, flags);
 
 	return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32));
 }
 
-static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
-		size_t count, loff_t *f_pos)
+static ssize_t cpu_latency_qos_write(struct file *filp, const char __user *buf,
+				     size_t count, loff_t *f_pos)
 {
 	s32 value;
-	struct pm_qos_request *req;
 
 	if (count == sizeof(s32)) {
 		if (copy_from_user(&value, buf, sizeof(s32)))
@@ -620,36 +391,38 @@
 			return ret;
 	}
 
-	req = filp->private_data;
-	pm_qos_update_request(req, value);
+	cpu_latency_qos_update_request(filp->private_data, value);
 
 	return count;
 }
 
+static const struct file_operations cpu_latency_qos_fops = {
+	.write = cpu_latency_qos_write,
+	.read = cpu_latency_qos_read,
+	.open = cpu_latency_qos_open,
+	.release = cpu_latency_qos_release,
+	.llseek = noop_llseek,
+};
 
-static int __init pm_qos_power_init(void)
+static struct miscdevice cpu_latency_qos_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "cpu_dma_latency",
+	.fops = &cpu_latency_qos_fops,
+};
+
+static int __init cpu_latency_qos_init(void)
 {
-	int ret = 0;
-	int i;
-	struct dentry *d;
+	int ret;
 
-	BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);
-
-	d = debugfs_create_dir("pm_qos", NULL);
-
-	for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
-		ret = register_pm_qos_misc(pm_qos_array[i], d);
-		if (ret < 0) {
-			pr_err("%s: %s setup failed\n",
-			       __func__, pm_qos_array[i]->name);
-			return ret;
-		}
-	}
+	ret = misc_register(&cpu_latency_qos_miscdev);
+	if (ret < 0)
+		pr_err("%s: %s setup failed\n", __func__,
+		       cpu_latency_qos_miscdev.name);
 
 	return ret;
 }
-
-late_initcall(pm_qos_power_init);
+late_initcall(cpu_latency_qos_init);
+#endif /* CONFIG_CPU_IDLE */
 
 /* Definitions related to the frequency QoS below. */
 
@@ -714,8 +487,10 @@
  * @req: Constraint request to apply.
  * @action: Action to perform (add/update/remove).
  * @value: Value to assign to the QoS request.
+ *
+ * This is only meant to be called from inside pm_qos, not drivers.
  */
-static int freq_qos_apply(struct freq_qos_request *req,
+int freq_qos_apply(struct freq_qos_request *req,
 			  enum pm_qos_req_action action, s32 value)
 {
 	int ret;
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index d65f2d5..1da013f 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -8,7 +8,7 @@
  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
  */
 
-#define pr_fmt(fmt) "PM: " fmt
+#define pr_fmt(fmt) "PM: hibernation: " fmt
 
 #include <linux/version.h>
 #include <linux/module.h>
@@ -34,7 +34,6 @@
 
 #include <linux/uaccess.h>
 #include <asm/mmu_context.h>
-#include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 #include <asm/io.h>
 
@@ -736,7 +735,7 @@
 	 */
 
 	/*
-	 * If the zone we wish to scan is the the current zone and the
+	 * If the zone we wish to scan is the current zone and the
 	 * pfn falls into the current node then we do not need to walk
 	 * the tree.
 	 */
@@ -945,8 +944,7 @@
  * Register a range of page frames the contents of which should not be saved
  * during hibernation (to be used in the early initialization code).
  */
-void __init __register_nosave_region(unsigned long start_pfn,
-				     unsigned long end_pfn, int use_kmalloc)
+void __init register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
 {
 	struct nosave_region *region;
 
@@ -962,18 +960,12 @@
 			goto Report;
 		}
 	}
-	if (use_kmalloc) {
-		/* During init, this shouldn't fail */
-		region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
-		BUG_ON(!region);
-	} else {
-		/* This allocation cannot fail */
-		region = memblock_alloc(sizeof(struct nosave_region),
-					SMP_CACHE_BYTES);
-		if (!region)
-			panic("%s: Failed to allocate %zu bytes\n", __func__,
-			      sizeof(struct nosave_region));
-	}
+	/* This allocation cannot fail */
+	region = memblock_alloc(sizeof(struct nosave_region),
+				SMP_CACHE_BYTES);
+	if (!region)
+		panic("%s: Failed to allocate %zu bytes\n", __func__,
+		      sizeof(struct nosave_region));
 	region->start_pfn = start_pfn;
 	region->end_pfn = end_pfn;
 	list_add_tail(&region->list, &nosave_regions);
@@ -1566,9 +1558,7 @@
  */
 static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
 {
-	x *= multiplier;
-	do_div(x, base);
-	return (unsigned long)x;
+	return div64_u64(x * multiplier, base);
 }
 
 static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
@@ -1666,7 +1656,7 @@
 {
 	unsigned long size;
 
-	size = global_node_page_state(NR_SLAB_RECLAIMABLE)
+	size = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B)
 		+ global_node_page_state(NR_ACTIVE_ANON)
 		+ global_node_page_state(NR_INACTIVE_ANON)
 		+ global_node_page_state(NR_ACTIVE_FILE)
@@ -1683,7 +1673,7 @@
  * hibernation for allocations made while saving the image and for device
  * drivers, in case they need to allocate memory from their hibernation
  * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
- * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
+ * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
  * /sys/power/reserved_size, respectively).  To make this happen, we compute the
  * total number of available page frames and allocate at least
  *
@@ -1705,16 +1695,20 @@
 	ktime_t start, stop;
 	int error;
 
-	pr_info("Preallocating image memory... ");
+	pr_info("Preallocating image memory\n");
 	start = ktime_get();
 
 	error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
-	if (error)
+	if (error) {
+		pr_err("Cannot allocate original bitmap\n");
 		goto err_out;
+	}
 
 	error = memory_bm_create(&copy_bm, GFP_IMAGE, PG_ANY);
-	if (error)
+	if (error) {
+		pr_err("Cannot allocate copy bitmap\n");
 		goto err_out;
+	}
 
 	alloc_normal = 0;
 	alloc_highmem = 0;
@@ -1742,9 +1736,6 @@
 	count += highmem;
 	count -= totalreserve_pages;
 
-	/* Add number of pages required for page keys (s390 only). */
-	size += page_key_additional_pages(saveable);
-
 	/* Compute the maximum number of saveable pages to leave in memory. */
 	max_size = (count - (size + PAGES_FOR_IO)) / 2
 			- 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
@@ -1804,8 +1795,11 @@
 		alloc -= pages;
 		pages += pages_highmem;
 		pages_highmem = preallocate_image_highmem(alloc);
-		if (pages_highmem < alloc)
+		if (pages_highmem < alloc) {
+			pr_err("Image allocation is %lu pages short\n",
+				alloc - pages_highmem);
 			goto err_out;
+		}
 		pages += pages_highmem;
 		/*
 		 * size is the desired number of saveable pages to leave in
@@ -1836,13 +1830,12 @@
 
  out:
 	stop = ktime_get();
-	pr_cont("done (allocated %lu pages)\n", pages);
+	pr_info("Allocated %lu pages for snapshot\n", pages);
 	swsusp_show_speed(start, stop, pages, "Allocated");
 
 	return 0;
 
  err_out:
-	pr_cont("\n");
 	swsusp_free();
 	return -ENOMEM;
 }
@@ -1976,7 +1969,7 @@
 {
 	unsigned int nr_pages, nr_highmem;
 
-	pr_info("Creating hibernation image:\n");
+	pr_info("Creating image:\n");
 
 	drain_local_pages(NULL);
 	nr_pages = count_data_pages();
@@ -2010,7 +2003,7 @@
 	nr_copy_pages = nr_pages;
 	nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
 
-	pr_info("Hibernation image created (%d pages copied)\n", nr_pages);
+	pr_info("Image created (%d pages copied)\n", nr_pages);
 
 	return 0;
 }
@@ -2023,7 +2016,7 @@
 	return 0;
 }
 
-static char *check_image_kernel(struct swsusp_info *info)
+static const char *check_image_kernel(struct swsusp_info *info)
 {
 	if (info->version_code != LINUX_VERSION_CODE)
 		return "kernel version";
@@ -2071,8 +2064,6 @@
 		buf[j] = memory_bm_next_pfn(bm);
 		if (unlikely(buf[j] == BM_END_OF_MAP))
 			break;
-		/* Save page key for data page (s390 only). */
-		page_key_read(buf + j);
 	}
 }
 
@@ -2178,7 +2169,7 @@
 
 static int check_header(struct swsusp_info *info)
 {
-	char *reason;
+	const char *reason;
 
 	reason = check_image_kernel(info);
 	if (!reason && info->num_physpages != get_num_physpages())
@@ -2222,9 +2213,6 @@
 		if (unlikely(buf[j] == BM_END_OF_MAP))
 			break;
 
-		/* Extract and buffer page key for data page (s390 only). */
-		page_key_memorize(buf + j);
-
 		if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
 			memory_bm_set_bit(bm, buf[j]);
 		else
@@ -2619,11 +2607,6 @@
 		if (error)
 			return error;
 
-		/* Allocate buffer for page keys. */
-		error = page_key_alloc(nr_copy_pages);
-		if (error)
-			return error;
-
 		hibernate_restore_protection_begin();
 	} else if (handle->cur <= nr_meta_pages + 1) {
 		error = unpack_orig_pfns(buffer, &copy_bm);
@@ -2645,8 +2628,6 @@
 		}
 	} else {
 		copy_last_highmem_page();
-		/* Restore page key for data page (s390 only). */
-		page_key_write(handle->buffer);
 		hibernate_restore_protect_page(handle->buffer);
 		handle->buffer = get_buffer(&orig_bm, &ca);
 		if (IS_ERR(handle->buffer))
@@ -2669,9 +2650,6 @@
 void snapshot_write_finalize(struct snapshot_handle *handle)
 {
 	copy_last_highmem_page();
-	/* Restore page key for data page (s390 only). */
-	page_key_write(handle->buffer);
-	page_key_free();
 	hibernate_restore_protect_page(handle->buffer);
 	/* Do that only if we have loaded the image entirely */
 	if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 27f149f..4aa4d5d 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -138,8 +138,6 @@
 			break;
 		}
 
-		pm_wakeup_clear(false);
-
 		s2idle_enter();
 	}
 
@@ -342,18 +340,16 @@
  */
 static int suspend_prepare(suspend_state_t state)
 {
-	int error, nr_calls = 0;
+	int error;
 
 	if (!sleep_state_supported(state))
 		return -EPERM;
 
 	pm_prepare_console();
 
-	error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
-	if (error) {
-		nr_calls--;
-		goto Finish;
-	}
+	error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
+	if (error)
+		goto Restore;
 
 	trace_suspend_resume(TPS("freeze_processes"), 0, true);
 	error = suspend_freeze_processes();
@@ -363,8 +359,8 @@
 
 	suspend_stats.failed_freeze++;
 	dpm_save_failed_step(SUSPEND_FREEZE);
- Finish:
-	__pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
+	pm_notifier_call_chain(PM_POST_SUSPEND);
+ Restore:
 	pm_restore_console();
 	return error;
 }
@@ -565,7 +561,7 @@
 	if (state == PM_SUSPEND_TO_IDLE)
 		s2idle_begin();
 
-	if (!IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC)) {
+	if (sync_on_suspend_enabled) {
 		trace_suspend_resume(TPS("sync_filesystems"), 0, true);
 		ksys_sync_helper();
 		trace_suspend_resume(TPS("sync_filesystems"), 0, false);
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 60564b5..e1ed58a 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -70,7 +70,7 @@
 	static char info_test[] __initdata =
 		KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
 
-	unsigned long		now;
+	time64_t		now;
 	struct rtc_wkalrm	alm;
 	int			status;
 
@@ -81,10 +81,10 @@
 		printk(err_readtime, dev_name(&rtc->dev), status);
 		return;
 	}
-	rtc_tm_to_time(&alm.time, &now);
+	now = rtc_tm_to_time64(&alm.time);
 
 	memset(&alm, 0, sizeof alm);
-	rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
+	rtc_time64_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
 	alm.enabled = true;
 
 	status = rtc_set_alarm(rtc, &alm);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 0516c42..25e7cb9 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -226,6 +226,7 @@
 	atomic_t		count;
 	wait_queue_head_t	wait;
 	blk_status_t		error;
+	struct blk_plug		plug;
 };
 
 static void hib_init_batch(struct hib_bio_batch *hb)
@@ -233,6 +234,12 @@
 	atomic_set(&hb->count, 0);
 	init_waitqueue_head(&hb->wait);
 	hb->error = BLK_STS_OK;
+	blk_start_plug(&hb->plug);
+}
+
+static void hib_finish_batch(struct hib_bio_batch *hb)
+{
+	blk_finish_plug(&hb->plug);
 }
 
 static void hib_end_io(struct bio *bio)
@@ -292,8 +299,12 @@
 	return error;
 }
 
-static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
+static int hib_wait_io(struct hib_bio_batch *hb)
 {
+	/*
+	 * We are relying on the behavior of blk_plug that a thread with
+	 * a plug will flush the plug list before sleeping.
+	 */
 	wait_event(hb->wait, atomic_read(&hb->count) == 0);
 	return blk_status_to_errno(hb->error);
 }
@@ -335,26 +346,23 @@
 {
 	int res;
 
-	res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
-			&hib_resume_bdev);
+	if (swsusp_resume_device)
+		res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
+	else
+		res = find_first_swap(&swsusp_resume_device);
 	if (res < 0)
 		return res;
-
 	root_swap = res;
-	res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
-	if (res)
-		return res;
+
+	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE,
+			NULL);
+	if (IS_ERR(hib_resume_bdev))
+		return PTR_ERR(hib_resume_bdev);
 
 	res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 	if (res < 0)
 		blkdev_put(hib_resume_bdev, FMODE_WRITE);
 
-	/*
-	 * Update the resume device to the one actually used,
-	 * so the test_resume mode can use it in case it is
-	 * invoked from hibernate() to test the snapshot.
-	 */
-	swsusp_resume_device = hib_resume_bdev->bd_dev;
 	return res;
 }
 
@@ -561,6 +569,7 @@
 		nr_pages++;
 	}
 	err2 = hib_wait_io(&hb);
+	hib_finish_batch(&hb);
 	stop = ktime_get();
 	if (!ret)
 		ret = err2;
@@ -854,6 +863,7 @@
 		pr_info("Image saving done\n");
 	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 out_clean:
+	hib_finish_batch(&hb);
 	if (crc) {
 		if (crc->thr)
 			kthread_stop(crc->thr);
@@ -1084,6 +1094,7 @@
 		nr_pages++;
 	}
 	err2 = hib_wait_io(&hb);
+	hib_finish_batch(&hb);
 	stop = ktime_get();
 	if (!ret)
 		ret = err2;
@@ -1447,6 +1458,7 @@
 	}
 	swsusp_show_speed(start, stop, nr_to_read, "Read");
 out_clean:
+	hib_finish_batch(&hb);
 	for (i = 0; i < ring_size; i++)
 		free_page((unsigned long)page[i]);
 	if (crc) {
@@ -1509,9 +1521,10 @@
 int swsusp_check(void)
 {
 	int error;
+	void *holder;
 
 	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
-					    FMODE_READ, NULL);
+					    FMODE_READ | FMODE_EXCL, &holder);
 	if (!IS_ERR(hib_resume_bdev)) {
 		set_blocksize(hib_resume_bdev, PAGE_SIZE);
 		clear_page(swsusp_header);
@@ -1533,7 +1546,7 @@
 
 put:
 		if (error)
-			blkdev_put(hib_resume_bdev, FMODE_READ);
+			blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL);
 		else
 			pr_debug("Image signature found, resuming\n");
 	} else {
@@ -1590,7 +1603,7 @@
 }
 #endif
 
-static int swsusp_header_init(void)
+static int __init swsusp_header_init(void)
 {
 	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
 	if (!swsusp_header)
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 7743895..740723b 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -27,8 +27,6 @@
 #include "power.h"
 
 
-#define SNAPSHOT_MINOR	231
-
 static struct snapshot_data {
 	struct snapshot_handle handle;
 	int swap;
@@ -37,27 +35,31 @@
 	bool ready;
 	bool platform_support;
 	bool free_bitmaps;
+	dev_t dev;
 } snapshot_state;
 
-atomic_t snapshot_device_available = ATOMIC_INIT(1);
+int is_hibernate_resume_dev(dev_t dev)
+{
+	return hibernation_available() && snapshot_state.dev == dev;
+}
 
 static int snapshot_open(struct inode *inode, struct file *filp)
 {
 	struct snapshot_data *data;
-	int error, nr_calls = 0;
+	int error;
 
 	if (!hibernation_available())
 		return -EPERM;
 
 	lock_system_sleep();
 
-	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+	if (!hibernate_acquire()) {
 		error = -EBUSY;
 		goto Unlock;
 	}
 
 	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
-		atomic_inc(&snapshot_device_available);
+		hibernate_release();
 		error = -ENOSYS;
 		goto Unlock;
 	}
@@ -67,13 +69,10 @@
 	memset(&data->handle, 0, sizeof(struct snapshot_handle));
 	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
 		/* Hibernating.  The image device should be accessible. */
-		data->swap = swsusp_resume_device ?
-			swap_type_of(swsusp_resume_device, 0, NULL) : -1;
+		data->swap = swap_type_of(swsusp_resume_device, 0);
 		data->mode = O_RDONLY;
 		data->free_bitmaps = false;
-		error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
-		if (error)
-			__pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
+		error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 	} else {
 		/*
 		 * Resuming.  We may need to wait for the image device to
@@ -83,22 +82,19 @@
 
 		data->swap = -1;
 		data->mode = O_WRONLY;
-		error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
+		error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
 		if (!error) {
 			error = create_basic_memory_bitmaps();
 			data->free_bitmaps = !error;
-		} else
-			nr_calls--;
-
-		if (error)
-			__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
+		}
 	}
 	if (error)
-		atomic_inc(&snapshot_device_available);
+		hibernate_release();
 
 	data->frozen = false;
 	data->ready = false;
 	data->platform_support = false;
+	data->dev = 0;
 
  Unlock:
 	unlock_system_sleep();
@@ -114,6 +110,7 @@
 
 	swsusp_free();
 	data = filp->private_data;
+	data->dev = 0;
 	free_all_swap_pages(data->swap);
 	if (data->frozen) {
 		pm_restore_gfp_mask();
@@ -124,7 +121,7 @@
 	}
 	pm_notifier_call_chain(data->mode == O_RDONLY ?
 			PM_POST_HIBERNATION : PM_POST_RESTORE);
-	atomic_inc(&snapshot_device_available);
+	hibernate_release();
 
 	unlock_system_sleep();
 
@@ -198,6 +195,47 @@
 	return res;
 }
 
+struct compat_resume_swap_area {
+	compat_loff_t offset;
+	u32 dev;
+} __packed;
+
+static int snapshot_set_swap_area(struct snapshot_data *data,
+		void __user *argp)
+{
+	sector_t offset;
+	dev_t swdev;
+
+	if (swsusp_swap_in_use())
+		return -EPERM;
+
+	if (in_compat_syscall()) {
+		struct compat_resume_swap_area swap_area;
+
+		if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
+			return -EFAULT;
+		swdev = new_decode_dev(swap_area.dev);
+		offset = swap_area.offset;
+	} else {
+		struct resume_swap_area swap_area;
+
+		if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
+			return -EFAULT;
+		swdev = new_decode_dev(swap_area.dev);
+		offset = swap_area.offset;
+	}
+
+	/*
+	 * User space encodes device types as two-byte values,
+	 * so we need to recode them
+	 */
+	data->swap = swap_type_of(swdev, offset);
+	if (data->swap < 0)
+		return swdev ? -ENODEV : -EINVAL;
+	data->dev = swdev;
+	return 0;
+}
+
 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
 							unsigned long arg)
 {
@@ -353,34 +391,7 @@
 		break;
 
 	case SNAPSHOT_SET_SWAP_AREA:
-		if (swsusp_swap_in_use()) {
-			error = -EPERM;
-		} else {
-			struct resume_swap_area swap_area;
-			dev_t swdev;
-
-			error = copy_from_user(&swap_area, (void __user *)arg,
-					sizeof(struct resume_swap_area));
-			if (error) {
-				error = -EFAULT;
-				break;
-			}
-
-			/*
-			 * User space encodes device types as two-byte values,
-			 * so we need to recode them
-			 */
-			swdev = new_decode_dev(swap_area.dev);
-			if (swdev) {
-				offset = swap_area.offset;
-				data->swap = swap_type_of(swdev, offset, NULL);
-				if (data->swap < 0)
-					error = -ENODEV;
-			} else {
-				data->swap = -1;
-				error = -EINVAL;
-			}
-		}
+		error = snapshot_set_swap_area(data, (void __user *)arg);
 		break;
 
 	default:
@@ -395,12 +406,6 @@
 }
 
 #ifdef CONFIG_COMPAT
-
-struct compat_resume_swap_area {
-	compat_loff_t offset;
-	u32 dev;
-} __packed;
-
 static long
 snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
@@ -409,49 +414,15 @@
 	switch (cmd) {
 	case SNAPSHOT_GET_IMAGE_SIZE:
 	case SNAPSHOT_AVAIL_SWAP_SIZE:
-	case SNAPSHOT_ALLOC_SWAP_PAGE: {
-		compat_loff_t __user *uoffset = compat_ptr(arg);
-		loff_t offset;
-		mm_segment_t old_fs;
-		int err;
-
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
-		err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
-		set_fs(old_fs);
-		if (!err && put_user(offset, uoffset))
-			err = -EFAULT;
-		return err;
-	}
-
+	case SNAPSHOT_ALLOC_SWAP_PAGE:
 	case SNAPSHOT_CREATE_IMAGE:
+	case SNAPSHOT_SET_SWAP_AREA:
 		return snapshot_ioctl(file, cmd,
 				      (unsigned long) compat_ptr(arg));
-
-	case SNAPSHOT_SET_SWAP_AREA: {
-		struct compat_resume_swap_area __user *u_swap_area =
-			compat_ptr(arg);
-		struct resume_swap_area swap_area;
-		mm_segment_t old_fs;
-		int err;
-
-		err = get_user(swap_area.offset, &u_swap_area->offset);
-		err |= get_user(swap_area.dev, &u_swap_area->dev);
-		if (err)
-			return -EFAULT;
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
-		err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
-				     (unsigned long) &swap_area);
-		set_fs(old_fs);
-		return err;
-	}
-
 	default:
 		return snapshot_ioctl(file, cmd, arg);
 	}
 }
-
 #endif /* CONFIG_COMPAT */
 
 static const struct file_operations snapshot_fops = {
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
index 105df4d..52571dc 100644
--- a/kernel/power/wakelock.c
+++ b/kernel/power/wakelock.c
@@ -39,23 +39,20 @@
 {
 	struct rb_node *node;
 	struct wakelock *wl;
-	char *str = buf;
-	char *end = buf + PAGE_SIZE;
+	int len = 0;
 
 	mutex_lock(&wakelocks_lock);
 
 	for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) {
 		wl = rb_entry(node, struct wakelock, node);
 		if (wl->ws->active == show_active)
-			str += scnprintf(str, end - str, "%s ", wl->name);
+			len += sysfs_emit_at(buf, len, "%s ", wl->name);
 	}
-	if (str > buf)
-		str--;
 
-	str += scnprintf(str, end - str, "\n");
+	len += sysfs_emit_at(buf, len, "\n");
 
 	mutex_unlock(&wakelocks_lock);
-	return (str - buf);
+	return len;
 }
 
 #if CONFIG_PM_WAKELOCKS_LIMIT > 0
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index 4d052fc..eee3dc9 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -2,3 +2,4 @@
 obj-y	= printk.o
 obj-$(CONFIG_PRINTK)	+= printk_safe.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
+obj-$(CONFIG_PRINTK)	+= printk_ringbuffer.o
diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h
index 11f19c4..3ca74ad 100644
--- a/kernel/printk/console_cmdline.h
+++ b/kernel/printk/console_cmdline.h
@@ -6,6 +6,7 @@
 {
 	char	name[16];			/* Name of the driver	    */
 	int	index;				/* Minor dev. to use	    */
+	bool	user_specified;			/* Specified by command line vs. platform */
 	char	*options;			/* Options for the driver   */
 #ifdef CONFIG_A11Y_BRAILLE_CONSOLE
 	char	*brl_options;			/* Options for braille driver */
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
index b2b0f52..3a8fd49 100644
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -6,15 +6,17 @@
 
 #ifdef CONFIG_PRINTK
 
-#define PRINTK_SAFE_CONTEXT_MASK	 0x3fffffff
-#define PRINTK_NMI_DIRECT_CONTEXT_MASK	 0x40000000
-#define PRINTK_NMI_CONTEXT_MASK		 0x80000000
+#define PRINTK_SAFE_CONTEXT_MASK	0x007ffffff
+#define PRINTK_NMI_DIRECT_CONTEXT_MASK	0x008000000
+#define PRINTK_NMI_CONTEXT_MASK		0xff0000000
+
+#define PRINTK_NMI_CONTEXT_OFFSET	0x010000000
 
 extern raw_spinlock_t logbuf_lock;
 
-__printf(5, 0)
+__printf(4, 0)
 int vprintk_store(int facility, int level,
-		  const char *dict, size_t dictlen,
+		  const struct dev_printk_info *dev_info,
 		  const char *fmt, va_list args);
 
 __printf(1, 0) int vprintk_default(const char *fmt, va_list args);
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5569ef6..85351a1 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -35,7 +35,6 @@
 #include <linux/memblock.h>
 #include <linux/syscalls.h>
 #include <linux/crash_core.h>
-#include <linux/kdb.h>
 #include <linux/ratelimit.h>
 #include <linux/kmsg_dump.h>
 #include <linux/syslog.h>
@@ -56,6 +55,7 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/printk.h>
 
+#include "printk_ringbuffer.h"
 #include "console_cmdline.h"
 #include "braille.h"
 #include "internal.h"
@@ -173,7 +173,7 @@
 char devkmsg_log_str[DEVKMSG_STR_MAX_SIZE] = "ratelimit";
 
 int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
-			      void __user *buffer, size_t *lenp, loff_t *ppos)
+			      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char old_str[DEVKMSG_STR_MAX_SIZE];
 	unsigned int old;
@@ -248,7 +248,7 @@
 {
 	unsigned long flags;
 
-	mutex_release(&console_lock_dep_map, 1, ip);
+	mutex_release(&console_lock_dep_map, ip);
 
 	printk_safe_enter_irqsave(flags);
 	up(&console_sem);
@@ -280,6 +280,7 @@
 static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
 
 static int preferred_console = -1;
+static bool has_preferred_console;
 int console_set_on_cmdline;
 EXPORT_SYMBOL(console_set_on_cmdline);
 
@@ -294,30 +295,22 @@
 static int console_msg_format = MSG_FORMAT_DEFAULT;
 
 /*
- * The printk log buffer consists of a chain of concatenated variable
- * length records. Every record starts with a record header, containing
- * the overall length of the record.
+ * The printk log buffer consists of a sequenced collection of records, each
+ * containing variable length message text. Every record also contains its
+ * own meta-data (@info).
  *
- * The heads to the first and last entry in the buffer, as well as the
- * sequence numbers of these entries are maintained when messages are
- * stored.
+ * Every record meta-data carries the timestamp in microseconds, as well as
+ * the standard userspace syslog level and syslog facility. The usual kernel
+ * messages use LOG_KERN; userspace-injected messages always carry a matching
+ * syslog facility, by default LOG_USER. The origin of every message can be
+ * reliably determined that way.
  *
- * If the heads indicate available messages, the length in the header
- * tells the start next message. A length == 0 for the next message
- * indicates a wrap-around to the beginning of the buffer.
+ * The human readable log message of a record is available in @text, the
+ * length of the message text in @text_len. The stored message is not
+ * terminated.
  *
- * Every record carries the monotonic timestamp in microseconds, as well as
- * the standard userspace syslog level and syslog facility. The usual
- * kernel messages use LOG_KERN; userspace-injected messages always carry
- * a matching syslog facility, by default LOG_USER. The origin of every
- * message can be reliably determined that way.
- *
- * The human readable log message directly follows the message header. The
- * length of the message text is stored in the header, the stored message
- * is not terminated.
- *
- * Optionally, a message can carry a dictionary of properties (key/value pairs),
- * to provide userspace with a machine-readable message context.
+ * Optionally, a record can carry a dictionary of properties (key/value
+ * pairs), to provide userspace with a machine-readable message context.
  *
  * Examples for well-defined, commonly used property names are:
  *   DEVICE=b12:8               device identifier
@@ -327,25 +320,22 @@
  *                                +sound:card0  subsystem:devname
  *   SUBSYSTEM=pci              driver-core subsystem name
  *
- * Valid characters in property names are [a-zA-Z0-9.-_]. The plain text value
- * follows directly after a '=' character. Every property is terminated by
- * a '\0' character. The last property is not terminated.
+ * Valid characters in property names are [a-zA-Z0-9.-_]. Property names
+ * and values are terminated by a '\0' character.
  *
- * Example of a message structure:
- *   0000  ff 8f 00 00 00 00 00 00      monotonic time in nsec
- *   0008  34 00                        record is 52 bytes long
- *   000a        0b 00                  text is 11 bytes long
- *   000c              1f 00            dictionary is 23 bytes long
- *   000e                    03 00      LOG_KERN (facility) LOG_ERR (level)
- *   0010  69 74 27 73 20 61 20 6c      "it's a l"
- *         69 6e 65                     "ine"
- *   001b           44 45 56 49 43      "DEVIC"
- *         45 3d 62 38 3a 32 00 44      "E=b8:2\0D"
- *         52 49 56 45 52 3d 62 75      "RIVER=bu"
- *         67                           "g"
- *   0032     00 00 00                  padding to next message header
+ * Example of record values:
+ *   record.text_buf                = "it's a line" (unterminated)
+ *   record.info.seq                = 56
+ *   record.info.ts_nsec            = 36863
+ *   record.info.text_len           = 11
+ *   record.info.facility           = 0 (LOG_KERN)
+ *   record.info.flags              = 0
+ *   record.info.level              = 3 (LOG_ERR)
+ *   record.info.caller_id          = 299 (task 299)
+ *   record.info.dev_info.subsystem = "pci" (terminated)
+ *   record.info.dev_info.device    = "+pci:0000:00:01.0" (terminated)
  *
- * The 'struct printk_log' buffer header must never be directly exported to
+ * The 'struct printk_info' buffer must never be directly exported to
  * userspace, it is a kernel-private implementation detail that might
  * need to be changed in the future, when the requirements change.
  *
@@ -365,23 +355,6 @@
 	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
 };
 
-struct printk_log {
-	u64 ts_nsec;		/* timestamp in nanoseconds */
-	u16 len;		/* length of entire record */
-	u16 text_len;		/* length of text buffer */
-	u16 dict_len;		/* length of dictionary buffer */
-	u8 facility;		/* syslog facility */
-	u8 flags:5;		/* internal record flags */
-	u8 level:3;		/* syslog level */
-#ifdef CONFIG_PRINTK_CALLER
-	u32 caller_id;            /* thread id or processor id */
-#endif
-}
-#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
-__packed __aligned(4)
-#endif
-;
-
 /*
  * The logbuf_lock protects kmsg buffer, indices, counters.  This can be taken
  * within the scheduler's rq lock. It must be released before calling
@@ -421,26 +394,16 @@
 DECLARE_WAIT_QUEUE_HEAD(log_wait);
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
 static u64 syslog_seq;
-static u32 syslog_idx;
 static size_t syslog_partial;
 static bool syslog_time;
 
-/* index and sequence number of the first record stored in the buffer */
-static u64 log_first_seq;
-static u32 log_first_idx;
-
-/* index and sequence number of the next record to store in the buffer */
-static u64 log_next_seq;
-static u32 log_next_idx;
-
 /* the next printk record to write to the console */
 static u64 console_seq;
-static u32 console_idx;
 static u64 exclusive_console_stop_seq;
+static unsigned long console_dropped;
 
 /* the next printk record to read after the last 'clear' command */
 static u64 clear_seq;
-static u32 clear_idx;
 
 #ifdef CONFIG_PRINTK_CALLER
 #define PREFIX_MAX		48
@@ -453,7 +416,7 @@
 #define LOG_FACILITY(v)		((v) >> 3 & 0xff)
 
 /* record buffer */
-#define LOG_ALIGN __alignof__(struct printk_log)
+#define LOG_ALIGN __alignof__(unsigned long)
 #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
 #define LOG_BUF_LEN_MAX (u32)(1 << 31)
 static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
@@ -461,6 +424,23 @@
 static u32 log_buf_len = __LOG_BUF_LEN;
 
 /*
+ * Define the average message size. This only affects the number of
+ * descriptors that will be available. Underestimating is better than
+ * overestimating (too many available descriptors is better than not enough).
+ */
+#define PRB_AVGBITS 5	/* 32 character average length */
+
+#if CONFIG_LOG_BUF_SHIFT <= PRB_AVGBITS
+#error CONFIG_LOG_BUF_SHIFT value too small.
+#endif
+_DEFINE_PRINTKRB(printk_rb_static, CONFIG_LOG_BUF_SHIFT - PRB_AVGBITS,
+		 PRB_AVGBITS, &__log_buf[0]);
+
+static struct printk_ringbuffer printk_rb_dynamic;
+
+static struct printk_ringbuffer *prb = &printk_rb_static;
+
+/*
  * We cannot access per-CPU data (e.g. per-CPU flush irq_work) before
  * per_cpu_areas are initialised. This variable is set to true when
  * it's safe to access per-CPU data.
@@ -484,108 +464,6 @@
 	return log_buf_len;
 }
 
-/* human readable text of the record */
-static char *log_text(const struct printk_log *msg)
-{
-	return (char *)msg + sizeof(struct printk_log);
-}
-
-/* optional key/value pair dictionary attached to the record */
-static char *log_dict(const struct printk_log *msg)
-{
-	return (char *)msg + sizeof(struct printk_log) + msg->text_len;
-}
-
-/* get record by index; idx must point to valid msg */
-static struct printk_log *log_from_idx(u32 idx)
-{
-	struct printk_log *msg = (struct printk_log *)(log_buf + idx);
-
-	/*
-	 * A length == 0 record is the end of buffer marker. Wrap around and
-	 * read the message at the start of the buffer.
-	 */
-	if (!msg->len)
-		return (struct printk_log *)log_buf;
-	return msg;
-}
-
-/* get next record; idx must point to valid msg */
-static u32 log_next(u32 idx)
-{
-	struct printk_log *msg = (struct printk_log *)(log_buf + idx);
-
-	/* length == 0 indicates the end of the buffer; wrap */
-	/*
-	 * A length == 0 record is the end of buffer marker. Wrap around and
-	 * read the message at the start of the buffer as *this* one, and
-	 * return the one after that.
-	 */
-	if (!msg->len) {
-		msg = (struct printk_log *)log_buf;
-		return msg->len;
-	}
-	return idx + msg->len;
-}
-
-/*
- * Check whether there is enough free space for the given message.
- *
- * The same values of first_idx and next_idx mean that the buffer
- * is either empty or full.
- *
- * If the buffer is empty, we must respect the position of the indexes.
- * They cannot be reset to the beginning of the buffer.
- */
-static int logbuf_has_space(u32 msg_size, bool empty)
-{
-	u32 free;
-
-	if (log_next_idx > log_first_idx || empty)
-		free = max(log_buf_len - log_next_idx, log_first_idx);
-	else
-		free = log_first_idx - log_next_idx;
-
-	/*
-	 * We need space also for an empty header that signalizes wrapping
-	 * of the buffer.
-	 */
-	return free >= msg_size + sizeof(struct printk_log);
-}
-
-static int log_make_free_space(u32 msg_size)
-{
-	while (log_first_seq < log_next_seq &&
-	       !logbuf_has_space(msg_size, false)) {
-		/* drop old messages until we have enough contiguous space */
-		log_first_idx = log_next(log_first_idx);
-		log_first_seq++;
-	}
-
-	if (clear_seq < log_first_seq) {
-		clear_seq = log_first_seq;
-		clear_idx = log_first_idx;
-	}
-
-	/* sequence numbers are equal, so the log buffer is empty */
-	if (logbuf_has_space(msg_size, log_first_seq == log_next_seq))
-		return 0;
-
-	return -ENOMEM;
-}
-
-/* compute the message size including the padding bytes */
-static u32 msg_used_size(u16 text_len, u16 dict_len, u32 *pad_len)
-{
-	u32 size;
-
-	size = sizeof(struct printk_log) + text_len + dict_len;
-	*pad_len = (-size) & (LOG_ALIGN - 1);
-	size += *pad_len;
-
-	return size;
-}
-
 /*
  * Define how much of the log buffer we could take at maximum. The value
  * must be greater than two. Note that only half of the buffer is available
@@ -594,84 +472,69 @@
 #define MAX_LOG_TAKE_PART 4
 static const char trunc_msg[] = "<truncated>";
 
-static u32 truncate_msg(u16 *text_len, u16 *trunc_msg_len,
-			u16 *dict_len, u32 *pad_len)
+static void truncate_msg(u16 *text_len, u16 *trunc_msg_len)
 {
 	/*
 	 * The message should not take the whole buffer. Otherwise, it might
 	 * get removed too soon.
 	 */
 	u32 max_text_len = log_buf_len / MAX_LOG_TAKE_PART;
+
 	if (*text_len > max_text_len)
 		*text_len = max_text_len;
-	/* enable the warning message */
+
+	/* enable the warning message (if there is room) */
 	*trunc_msg_len = strlen(trunc_msg);
-	/* disable the "dict" completely */
-	*dict_len = 0;
-	/* compute the size again, count also the warning message */
-	return msg_used_size(*text_len + *trunc_msg_len, 0, pad_len);
+	if (*text_len >= *trunc_msg_len)
+		*text_len -= *trunc_msg_len;
+	else
+		*trunc_msg_len = 0;
 }
 
 /* insert record into the buffer, discard old ones, update heads */
 static int log_store(u32 caller_id, int facility, int level,
 		     enum log_flags flags, u64 ts_nsec,
-		     const char *dict, u16 dict_len,
+		     const struct dev_printk_info *dev_info,
 		     const char *text, u16 text_len)
 {
-	struct printk_log *msg;
-	u32 size, pad_len;
+	struct prb_reserved_entry e;
+	struct printk_record r;
 	u16 trunc_msg_len = 0;
 
-	/* number of '\0' padding bytes to next message */
-	size = msg_used_size(text_len, dict_len, &pad_len);
+	prb_rec_init_wr(&r, text_len);
 
-	if (log_make_free_space(size)) {
+	if (!prb_reserve(&e, prb, &r)) {
 		/* truncate the message if it is too long for empty buffer */
-		size = truncate_msg(&text_len, &trunc_msg_len,
-				    &dict_len, &pad_len);
+		truncate_msg(&text_len, &trunc_msg_len);
+		prb_rec_init_wr(&r, text_len + trunc_msg_len);
 		/* survive when the log buffer is too small for trunc_msg */
-		if (log_make_free_space(size))
+		if (!prb_reserve(&e, prb, &r))
 			return 0;
 	}
 
-	if (log_next_idx + size + sizeof(struct printk_log) > log_buf_len) {
-		/*
-		 * This message + an additional empty header does not fit
-		 * at the end of the buffer. Add an empty header with len == 0
-		 * to signify a wrap around.
-		 */
-		memset(log_buf + log_next_idx, 0, sizeof(struct printk_log));
-		log_next_idx = 0;
-	}
-
 	/* fill message */
-	msg = (struct printk_log *)(log_buf + log_next_idx);
-	memcpy(log_text(msg), text, text_len);
-	msg->text_len = text_len;
-	if (trunc_msg_len) {
-		memcpy(log_text(msg) + text_len, trunc_msg, trunc_msg_len);
-		msg->text_len += trunc_msg_len;
-	}
-	memcpy(log_dict(msg), dict, dict_len);
-	msg->dict_len = dict_len;
-	msg->facility = facility;
-	msg->level = level & 7;
-	msg->flags = flags & 0x1f;
+	memcpy(&r.text_buf[0], text, text_len);
+	if (trunc_msg_len)
+		memcpy(&r.text_buf[text_len], trunc_msg, trunc_msg_len);
+	r.info->text_len = text_len + trunc_msg_len;
+	r.info->facility = facility;
+	r.info->level = level & 7;
+	r.info->flags = flags & 0x1f;
 	if (ts_nsec > 0)
-		msg->ts_nsec = ts_nsec;
+		r.info->ts_nsec = ts_nsec;
 	else
-		msg->ts_nsec = local_clock();
-#ifdef CONFIG_PRINTK_CALLER
-	msg->caller_id = caller_id;
-#endif
-	memset(log_dict(msg) + dict_len, 0, pad_len);
-	msg->len = size;
+		r.info->ts_nsec = local_clock();
+	r.info->caller_id = caller_id;
+	if (dev_info)
+		memcpy(&r.info->dev_info, dev_info, sizeof(r.info->dev_info));
 
-	/* insert message */
-	log_next_idx += msg->len;
-	log_next_seq++;
+	/* A message without a trailing newline can be continued. */
+	if (!(flags & LOG_NEWLINE))
+		prb_commit(&e);
+	else
+		prb_final_commit(&e);
 
-	return msg->text_len;
+	return (text_len + trunc_msg_len);
 }
 
 int dmesg_restrict = IS_ENABLED(CONFIG_SECURITY_DMESG_RESTRICT);
@@ -723,13 +586,13 @@
 		*(*pp)++ = c;
 }
 
-static ssize_t msg_print_ext_header(char *buf, size_t size,
-				    struct printk_log *msg, u64 seq)
+static ssize_t info_print_ext_header(char *buf, size_t size,
+				     struct printk_info *info)
 {
-	u64 ts_usec = msg->ts_nsec;
+	u64 ts_usec = info->ts_nsec;
 	char caller[20];
 #ifdef CONFIG_PRINTK_CALLER
-	u32 id = msg->caller_id;
+	u32 id = info->caller_id;
 
 	snprintf(caller, sizeof(caller), ",caller=%c%u",
 		 id & 0x80000000 ? 'C' : 'T', id & ~0x80000000);
@@ -740,13 +603,13 @@
 	do_div(ts_usec, 1000);
 
 	return scnprintf(buf, size, "%u,%llu,%llu,%c%s;",
-			 (msg->facility << 3) | msg->level, seq, ts_usec,
-			 msg->flags & LOG_CONT ? 'c' : '-', caller);
+			 (info->facility << 3) | info->level, info->seq,
+			 ts_usec, info->flags & LOG_CONT ? 'c' : '-', caller);
 }
 
-static ssize_t msg_print_ext_body(char *buf, size_t size,
-				  char *dict, size_t dict_len,
-				  char *text, size_t text_len)
+static ssize_t msg_add_ext_text(char *buf, size_t size,
+				const char *text, size_t text_len,
+				unsigned char endc)
 {
 	char *p = buf, *e = buf + size;
 	size_t i;
@@ -760,45 +623,56 @@
 		else
 			append_char(&p, e, c);
 	}
-	append_char(&p, e, '\n');
-
-	if (dict_len) {
-		bool line = true;
-
-		for (i = 0; i < dict_len; i++) {
-			unsigned char c = dict[i];
-
-			if (line) {
-				append_char(&p, e, ' ');
-				line = false;
-			}
-
-			if (c == '\0') {
-				append_char(&p, e, '\n');
-				line = true;
-				continue;
-			}
-
-			if (c < ' ' || c >= 127 || c == '\\') {
-				p += scnprintf(p, e - p, "\\x%02x", c);
-				continue;
-			}
-
-			append_char(&p, e, c);
-		}
-		append_char(&p, e, '\n');
-	}
+	append_char(&p, e, endc);
 
 	return p - buf;
 }
 
+static ssize_t msg_add_dict_text(char *buf, size_t size,
+				 const char *key, const char *val)
+{
+	size_t val_len = strlen(val);
+	ssize_t len;
+
+	if (!val_len)
+		return 0;
+
+	len = msg_add_ext_text(buf, size, "", 0, ' ');	/* dict prefix */
+	len += msg_add_ext_text(buf + len, size - len, key, strlen(key), '=');
+	len += msg_add_ext_text(buf + len, size - len, val, val_len, '\n');
+
+	return len;
+}
+
+static ssize_t msg_print_ext_body(char *buf, size_t size,
+				  char *text, size_t text_len,
+				  struct dev_printk_info *dev_info)
+{
+	ssize_t len;
+
+	len = msg_add_ext_text(buf, size, text, text_len, '\n');
+
+	if (!dev_info)
+		goto out;
+
+	len += msg_add_dict_text(buf + len, size - len, "SUBSYSTEM",
+				 dev_info->subsystem);
+	len += msg_add_dict_text(buf + len, size - len, "DEVICE",
+				 dev_info->device);
+out:
+	return len;
+}
+
 /* /dev/kmsg - userspace message inject/listen interface */
 struct devkmsg_user {
 	u64 seq;
-	u32 idx;
 	struct ratelimit_state rs;
 	struct mutex lock;
 	char buf[CONSOLE_EXT_LOG_MAX];
+
+	struct printk_info info;
+	char text_buf[CONSOLE_EXT_LOG_MAX];
+	struct printk_record record;
 };
 
 static __printf(3, 4) __cold
@@ -808,7 +682,7 @@
 	int r;
 
 	va_start(args, fmt);
-	r = vprintk_emit(facility, level, NULL, 0, fmt, args);
+	r = vprintk_emit(facility, level, NULL, fmt, args);
 	va_end(args);
 
 	return r;
@@ -881,7 +755,7 @@
 			    size_t count, loff_t *ppos)
 {
 	struct devkmsg_user *user = file->private_data;
-	struct printk_log *msg;
+	struct printk_record *r = &user->record;
 	size_t len;
 	ssize_t ret;
 
@@ -893,7 +767,7 @@
 		return ret;
 
 	logbuf_lock_irq();
-	while (user->seq == log_next_seq) {
+	if (!prb_read_valid(prb, user->seq, r)) {
 		if (file->f_flags & O_NONBLOCK) {
 			ret = -EAGAIN;
 			logbuf_unlock_irq();
@@ -902,30 +776,26 @@
 
 		logbuf_unlock_irq();
 		ret = wait_event_interruptible(log_wait,
-					       user->seq != log_next_seq);
+					prb_read_valid(prb, user->seq, r));
 		if (ret)
 			goto out;
 		logbuf_lock_irq();
 	}
 
-	if (user->seq < log_first_seq) {
+	if (r->info->seq != user->seq) {
 		/* our last seen message is gone, return error and reset */
-		user->idx = log_first_idx;
-		user->seq = log_first_seq;
+		user->seq = r->info->seq;
 		ret = -EPIPE;
 		logbuf_unlock_irq();
 		goto out;
 	}
 
-	msg = log_from_idx(user->idx);
-	len = msg_print_ext_header(user->buf, sizeof(user->buf),
-				   msg, user->seq);
+	len = info_print_ext_header(user->buf, sizeof(user->buf), r->info);
 	len += msg_print_ext_body(user->buf + len, sizeof(user->buf) - len,
-				  log_dict(msg), msg->dict_len,
-				  log_text(msg), msg->text_len);
+				  &r->text_buf[0], r->info->text_len,
+				  &r->info->dev_info);
 
-	user->idx = log_next(user->idx);
-	user->seq++;
+	user->seq = r->info->seq + 1;
 	logbuf_unlock_irq();
 
 	if (len > count) {
@@ -943,6 +813,14 @@
 	return ret;
 }
 
+/*
+ * Be careful when modifying this function!!!
+ *
+ * Only few operations are supported because the device works only with the
+ * entire variable length messages (records). Non-standard values are
+ * returned in the other cases and has been this way for quite some time.
+ * User space applications might depend on this behavior.
+ */
 static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 {
 	struct devkmsg_user *user = file->private_data;
@@ -957,8 +835,7 @@
 	switch (whence) {
 	case SEEK_SET:
 		/* the first record */
-		user->idx = log_first_idx;
-		user->seq = log_first_seq;
+		user->seq = prb_first_valid_seq(prb);
 		break;
 	case SEEK_DATA:
 		/*
@@ -966,13 +843,11 @@
 		 * like issued by 'dmesg -c'. Reading /dev/kmsg itself
 		 * changes no global state, and does not clear anything.
 		 */
-		user->idx = clear_idx;
 		user->seq = clear_seq;
 		break;
 	case SEEK_END:
 		/* after the last record */
-		user->idx = log_next_idx;
-		user->seq = log_next_seq;
+		user->seq = prb_next_seq(prb);
 		break;
 	default:
 		ret = -EINVAL;
@@ -984,6 +859,7 @@
 static __poll_t devkmsg_poll(struct file *file, poll_table *wait)
 {
 	struct devkmsg_user *user = file->private_data;
+	struct printk_info info;
 	__poll_t ret = 0;
 
 	if (!user)
@@ -992,9 +868,9 @@
 	poll_wait(file, &log_wait, wait);
 
 	logbuf_lock_irq();
-	if (user->seq < log_next_seq) {
+	if (prb_read_valid_info(prb, user->seq, &info, NULL)) {
 		/* return error when data has vanished underneath us */
-		if (user->seq < log_first_seq)
+		if (info.seq != user->seq)
 			ret = EPOLLIN|EPOLLRDNORM|EPOLLERR|EPOLLPRI;
 		else
 			ret = EPOLLIN|EPOLLRDNORM;
@@ -1029,9 +905,11 @@
 
 	mutex_init(&user->lock);
 
+	prb_rec_init_rd(&user->record, &user->info,
+			&user->text_buf[0], sizeof(user->text_buf));
+
 	logbuf_lock_irq();
-	user->idx = log_first_idx;
-	user->seq = log_first_seq;
+	user->seq = prb_first_valid_seq(prb);
 	logbuf_unlock_irq();
 
 	file->private_data = user;
@@ -1072,23 +950,58 @@
  */
 void log_buf_vmcoreinfo_setup(void)
 {
-	VMCOREINFO_SYMBOL(log_buf);
-	VMCOREINFO_SYMBOL(log_buf_len);
-	VMCOREINFO_SYMBOL(log_first_idx);
-	VMCOREINFO_SYMBOL(clear_idx);
-	VMCOREINFO_SYMBOL(log_next_idx);
+	struct dev_printk_info *dev_info = NULL;
+
+	VMCOREINFO_SYMBOL(prb);
+	VMCOREINFO_SYMBOL(printk_rb_static);
+	VMCOREINFO_SYMBOL(clear_seq);
+
 	/*
-	 * Export struct printk_log size and field offsets. User space tools can
+	 * Export struct size and field offsets. User space tools can
 	 * parse it and detect any changes to structure down the line.
 	 */
-	VMCOREINFO_STRUCT_SIZE(printk_log);
-	VMCOREINFO_OFFSET(printk_log, ts_nsec);
-	VMCOREINFO_OFFSET(printk_log, len);
-	VMCOREINFO_OFFSET(printk_log, text_len);
-	VMCOREINFO_OFFSET(printk_log, dict_len);
-#ifdef CONFIG_PRINTK_CALLER
-	VMCOREINFO_OFFSET(printk_log, caller_id);
-#endif
+
+	VMCOREINFO_STRUCT_SIZE(printk_ringbuffer);
+	VMCOREINFO_OFFSET(printk_ringbuffer, desc_ring);
+	VMCOREINFO_OFFSET(printk_ringbuffer, text_data_ring);
+	VMCOREINFO_OFFSET(printk_ringbuffer, fail);
+
+	VMCOREINFO_STRUCT_SIZE(prb_desc_ring);
+	VMCOREINFO_OFFSET(prb_desc_ring, count_bits);
+	VMCOREINFO_OFFSET(prb_desc_ring, descs);
+	VMCOREINFO_OFFSET(prb_desc_ring, infos);
+	VMCOREINFO_OFFSET(prb_desc_ring, head_id);
+	VMCOREINFO_OFFSET(prb_desc_ring, tail_id);
+
+	VMCOREINFO_STRUCT_SIZE(prb_desc);
+	VMCOREINFO_OFFSET(prb_desc, state_var);
+	VMCOREINFO_OFFSET(prb_desc, text_blk_lpos);
+
+	VMCOREINFO_STRUCT_SIZE(prb_data_blk_lpos);
+	VMCOREINFO_OFFSET(prb_data_blk_lpos, begin);
+	VMCOREINFO_OFFSET(prb_data_blk_lpos, next);
+
+	VMCOREINFO_STRUCT_SIZE(printk_info);
+	VMCOREINFO_OFFSET(printk_info, seq);
+	VMCOREINFO_OFFSET(printk_info, ts_nsec);
+	VMCOREINFO_OFFSET(printk_info, text_len);
+	VMCOREINFO_OFFSET(printk_info, caller_id);
+	VMCOREINFO_OFFSET(printk_info, dev_info);
+
+	VMCOREINFO_STRUCT_SIZE(dev_printk_info);
+	VMCOREINFO_OFFSET(dev_printk_info, subsystem);
+	VMCOREINFO_LENGTH(printk_info_subsystem, sizeof(dev_info->subsystem));
+	VMCOREINFO_OFFSET(dev_printk_info, device);
+	VMCOREINFO_LENGTH(printk_info_device, sizeof(dev_info->device));
+
+	VMCOREINFO_STRUCT_SIZE(prb_data_ring);
+	VMCOREINFO_OFFSET(prb_data_ring, size_bits);
+	VMCOREINFO_OFFSET(prb_data_ring, data);
+	VMCOREINFO_OFFSET(prb_data_ring, head_lpos);
+	VMCOREINFO_OFFSET(prb_data_ring, tail_lpos);
+
+	VMCOREINFO_SIZE(atomic_long_t);
+	VMCOREINFO_TYPE_OFFSET(atomic_long_t, counter);
 }
 #endif
 
@@ -1166,11 +1079,46 @@
 	__printk_percpu_data_ready = true;
 }
 
+static unsigned int __init add_to_rb(struct printk_ringbuffer *rb,
+				     struct printk_record *r)
+{
+	struct prb_reserved_entry e;
+	struct printk_record dest_r;
+
+	prb_rec_init_wr(&dest_r, r->info->text_len);
+
+	if (!prb_reserve(&e, rb, &dest_r))
+		return 0;
+
+	memcpy(&dest_r.text_buf[0], &r->text_buf[0], r->info->text_len);
+	dest_r.info->text_len = r->info->text_len;
+	dest_r.info->facility = r->info->facility;
+	dest_r.info->level = r->info->level;
+	dest_r.info->flags = r->info->flags;
+	dest_r.info->ts_nsec = r->info->ts_nsec;
+	dest_r.info->caller_id = r->info->caller_id;
+	memcpy(&dest_r.info->dev_info, &r->info->dev_info, sizeof(dest_r.info->dev_info));
+
+	prb_final_commit(&e);
+
+	return prb_record_text_space(&e);
+}
+
+static char setup_text_buf[LOG_LINE_MAX] __initdata;
+
 void __init setup_log_buf(int early)
 {
+	struct printk_info *new_infos;
+	unsigned int new_descs_count;
+	struct prb_desc *new_descs;
+	struct printk_info info;
+	struct printk_record r;
+	size_t new_descs_size;
+	size_t new_infos_size;
 	unsigned long flags;
 	char *new_log_buf;
 	unsigned int free;
+	u64 seq;
 
 	/*
 	 * Some archs call setup_log_buf() multiple times - first is very
@@ -1189,24 +1137,75 @@
 	if (!new_log_buf_len)
 		return;
 
-	new_log_buf = memblock_alloc(new_log_buf_len, LOG_ALIGN);
-	if (unlikely(!new_log_buf)) {
-		pr_err("log_buf_len: %lu bytes not available\n",
-			new_log_buf_len);
+	new_descs_count = new_log_buf_len >> PRB_AVGBITS;
+	if (new_descs_count == 0) {
+		pr_err("new_log_buf_len: %lu too small\n", new_log_buf_len);
 		return;
 	}
 
+	new_log_buf = memblock_alloc(new_log_buf_len, LOG_ALIGN);
+	if (unlikely(!new_log_buf)) {
+		pr_err("log_buf_len: %lu text bytes not available\n",
+		       new_log_buf_len);
+		return;
+	}
+
+	new_descs_size = new_descs_count * sizeof(struct prb_desc);
+	new_descs = memblock_alloc(new_descs_size, LOG_ALIGN);
+	if (unlikely(!new_descs)) {
+		pr_err("log_buf_len: %zu desc bytes not available\n",
+		       new_descs_size);
+		goto err_free_log_buf;
+	}
+
+	new_infos_size = new_descs_count * sizeof(struct printk_info);
+	new_infos = memblock_alloc(new_infos_size, LOG_ALIGN);
+	if (unlikely(!new_infos)) {
+		pr_err("log_buf_len: %zu info bytes not available\n",
+		       new_infos_size);
+		goto err_free_descs;
+	}
+
+	prb_rec_init_rd(&r, &info, &setup_text_buf[0], sizeof(setup_text_buf));
+
+	prb_init(&printk_rb_dynamic,
+		 new_log_buf, ilog2(new_log_buf_len),
+		 new_descs, ilog2(new_descs_count),
+		 new_infos);
+
 	logbuf_lock_irqsave(flags);
+
 	log_buf_len = new_log_buf_len;
 	log_buf = new_log_buf;
 	new_log_buf_len = 0;
-	free = __LOG_BUF_LEN - log_next_idx;
-	memcpy(log_buf, __log_buf, __LOG_BUF_LEN);
+
+	free = __LOG_BUF_LEN;
+	prb_for_each_record(0, &printk_rb_static, seq, &r)
+		free -= add_to_rb(&printk_rb_dynamic, &r);
+
+	/*
+	 * This is early enough that everything is still running on the
+	 * boot CPU and interrupts are disabled. So no new messages will
+	 * appear during the transition to the dynamic buffer.
+	 */
+	prb = &printk_rb_dynamic;
+
 	logbuf_unlock_irqrestore(flags);
 
+	if (seq != prb_next_seq(&printk_rb_static)) {
+		pr_err("dropped %llu messages\n",
+		       prb_next_seq(&printk_rb_static) - seq);
+	}
+
 	pr_info("log_buf_len: %u bytes\n", log_buf_len);
 	pr_info("early log buf free: %u(%u%%)\n",
 		free, (free * 100) / __LOG_BUF_LEN);
+	return;
+
+err_free_descs:
+	memblock_free(__pa(new_descs), new_descs_size);
+err_free_log_buf:
+	memblock_free(__pa(new_log_buf), new_log_buf_len);
 }
 
 static bool __read_mostly ignore_loglevel;
@@ -1313,18 +1312,18 @@
 #define print_caller(id, buf) 0
 #endif
 
-static size_t print_prefix(const struct printk_log *msg, bool syslog,
-			   bool time, char *buf)
+static size_t info_print_prefix(const struct printk_info  *info, bool syslog,
+				bool time, char *buf)
 {
 	size_t len = 0;
 
 	if (syslog)
-		len = print_syslog((msg->facility << 3) | msg->level, buf);
+		len = print_syslog((info->facility << 3) | info->level, buf);
 
 	if (time)
-		len += print_time(msg->ts_nsec, buf + len);
+		len += print_time(info->ts_nsec, buf + len);
 
-	len += print_caller(msg->caller_id, buf + len);
+	len += print_caller(info->caller_id, buf + len);
 
 	if (IS_ENABLED(CONFIG_PRINTK_CALLER) || time) {
 		buf[len++] = ' ';
@@ -1334,72 +1333,168 @@
 	return len;
 }
 
-static size_t msg_print_text(const struct printk_log *msg, bool syslog,
-			     bool time, char *buf, size_t size)
+/*
+ * Prepare the record for printing. The text is shifted within the given
+ * buffer to avoid a need for another one. The following operations are
+ * done:
+ *
+ *   - Add prefix for each line.
+ *   - Drop truncated lines that no longer fit into the buffer.
+ *   - Add the trailing newline that has been removed in vprintk_store().
+ *   - Add a string terminator.
+ *
+ * Since the produced string is always terminated, the maximum possible
+ * return value is @r->text_buf_size - 1;
+ *
+ * Return: The length of the updated/prepared text, including the added
+ * prefixes and the newline. The terminator is not counted. The dropped
+ * line(s) are not counted.
+ */
+static size_t record_print_text(struct printk_record *r, bool syslog,
+				bool time)
 {
-	const char *text = log_text(msg);
-	size_t text_size = msg->text_len;
-	size_t len = 0;
+	size_t text_len = r->info->text_len;
+	size_t buf_size = r->text_buf_size;
+	char *text = r->text_buf;
 	char prefix[PREFIX_MAX];
-	const size_t prefix_len = print_prefix(msg, syslog, time, prefix);
+	bool truncated = false;
+	size_t prefix_len;
+	size_t line_len;
+	size_t len = 0;
+	char *next;
 
-	do {
-		const char *next = memchr(text, '\n', text_size);
-		size_t text_len;
+	/*
+	 * If the message was truncated because the buffer was not large
+	 * enough, treat the available text as if it were the full text.
+	 */
+	if (text_len > buf_size)
+		text_len = buf_size;
 
+	prefix_len = info_print_prefix(r->info, syslog, time, prefix);
+
+	/*
+	 * @text_len: bytes of unprocessed text
+	 * @line_len: bytes of current line _without_ newline
+	 * @text:     pointer to beginning of current line
+	 * @len:      number of bytes prepared in r->text_buf
+	 */
+	for (;;) {
+		next = memchr(text, '\n', text_len);
 		if (next) {
-			text_len = next - text;
-			next++;
-			text_size -= next - text;
+			line_len = next - text;
 		} else {
-			text_len = text_size;
+			/* Drop truncated line(s). */
+			if (truncated)
+				break;
+			line_len = text_len;
 		}
 
-		if (buf) {
-			if (prefix_len + text_len + 1 >= size - len)
+		/*
+		 * Truncate the text if there is not enough space to add the
+		 * prefix and a trailing newline and a terminator.
+		 */
+		if (len + prefix_len + text_len + 1 + 1 > buf_size) {
+			/* Drop even the current line if no space. */
+			if (len + prefix_len + line_len + 1 + 1 > buf_size)
 				break;
 
-			memcpy(buf + len, prefix, prefix_len);
-			len += prefix_len;
-			memcpy(buf + len, text, text_len);
-			len += text_len;
-			buf[len++] = '\n';
-		} else {
-			/* SYSLOG_ACTION_* buffer size only calculation */
-			len += prefix_len + text_len + 1;
+			text_len = buf_size - len - prefix_len - 1 - 1;
+			truncated = true;
 		}
 
-		text = next;
-	} while (text);
+		memmove(text + prefix_len, text, text_len);
+		memcpy(text, prefix, prefix_len);
+
+		/*
+		 * Increment the prepared length to include the text and
+		 * prefix that were just moved+copied. Also increment for the
+		 * newline at the end of this line. If this is the last line,
+		 * there is no newline, but it will be added immediately below.
+		 */
+		len += prefix_len + line_len + 1;
+		if (text_len == line_len) {
+			/*
+			 * This is the last line. Add the trailing newline
+			 * removed in vprintk_store().
+			 */
+			text[prefix_len + line_len] = '\n';
+			break;
+		}
+
+		/*
+		 * Advance beyond the added prefix and the related line with
+		 * its newline.
+		 */
+		text += prefix_len + line_len + 1;
+
+		/*
+		 * The remaining text has only decreased by the line with its
+		 * newline.
+		 *
+		 * Note that @text_len can become zero. It happens when @text
+		 * ended with a newline (either due to truncation or the
+		 * original string ending with "\n\n"). The loop is correctly
+		 * repeated and (if not truncated) an empty line with a prefix
+		 * will be prepared.
+		 */
+		text_len -= line_len + 1;
+	}
+
+	/*
+	 * If a buffer was provided, it will be terminated. Space for the
+	 * string terminator is guaranteed to be available. The terminator is
+	 * not counted in the return value.
+	 */
+	if (buf_size > 0)
+		r->text_buf[len] = 0;
 
 	return len;
 }
 
+static size_t get_record_print_text_size(struct printk_info *info,
+					 unsigned int line_count,
+					 bool syslog, bool time)
+{
+	char prefix[PREFIX_MAX];
+	size_t prefix_len;
+
+	prefix_len = info_print_prefix(info, syslog, time, prefix);
+
+	/*
+	 * Each line will be preceded with a prefix. The intermediate
+	 * newlines are already within the text, but a final trailing
+	 * newline will be added.
+	 */
+	return ((prefix_len * line_count) + info->text_len + 1);
+}
+
 static int syslog_print(char __user *buf, int size)
 {
+	struct printk_info info;
+	struct printk_record r;
 	char *text;
-	struct printk_log *msg;
 	int len = 0;
 
 	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
 	if (!text)
 		return -ENOMEM;
 
+	prb_rec_init_rd(&r, &info, text, LOG_LINE_MAX + PREFIX_MAX);
+
 	while (size > 0) {
 		size_t n;
 		size_t skip;
 
 		logbuf_lock_irq();
-		if (syslog_seq < log_first_seq) {
-			/* messages are gone, move to first one */
-			syslog_seq = log_first_seq;
-			syslog_idx = log_first_idx;
-			syslog_partial = 0;
-		}
-		if (syslog_seq == log_next_seq) {
+		if (!prb_read_valid(prb, syslog_seq, &r)) {
 			logbuf_unlock_irq();
 			break;
 		}
+		if (r.info->seq != syslog_seq) {
+			/* message is gone, move to next valid one */
+			syslog_seq = r.info->seq;
+			syslog_partial = 0;
+		}
 
 		/*
 		 * To keep reading/counting partial line consistent,
@@ -1409,13 +1504,10 @@
 			syslog_time = printk_time;
 
 		skip = syslog_partial;
-		msg = log_from_idx(syslog_idx);
-		n = msg_print_text(msg, true, syslog_time, text,
-				   LOG_LINE_MAX + PREFIX_MAX);
+		n = record_print_text(&r, true, syslog_time);
 		if (n - syslog_partial <= size) {
 			/* message fits into buffer, move forward */
-			syslog_idx = log_next(syslog_idx);
-			syslog_seq++;
+			syslog_seq = r.info->seq + 1;
 			n -= syslog_partial;
 			syslog_partial = 0;
 		} else if (!len){
@@ -1446,11 +1538,12 @@
 
 static int syslog_print_all(char __user *buf, int size, bool clear)
 {
+	struct printk_info info;
+	unsigned int line_count;
+	struct printk_record r;
 	char *text;
 	int len = 0;
-	u64 next_seq;
 	u64 seq;
-	u32 idx;
 	bool time;
 
 	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
@@ -1463,38 +1556,28 @@
 	 * Find first record that fits, including all following records,
 	 * into the user-provided buffer for this dump.
 	 */
-	seq = clear_seq;
-	idx = clear_idx;
-	while (seq < log_next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
-
-		len += msg_print_text(msg, true, time, NULL, 0);
-		idx = log_next(idx);
-		seq++;
-	}
+	prb_for_each_info(clear_seq, prb, seq, &info, &line_count)
+		len += get_record_print_text_size(&info, line_count, true, time);
 
 	/* move first record forward until length fits into the buffer */
-	seq = clear_seq;
-	idx = clear_idx;
-	while (len > size && seq < log_next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
-
-		len -= msg_print_text(msg, true, time, NULL, 0);
-		idx = log_next(idx);
-		seq++;
+	prb_for_each_info(clear_seq, prb, seq, &info, &line_count) {
+		if (len <= size)
+			break;
+		len -= get_record_print_text_size(&info, line_count, true, time);
 	}
 
-	/* last message fitting into this dump */
-	next_seq = log_next_seq;
+	prb_rec_init_rd(&r, &info, text, LOG_LINE_MAX + PREFIX_MAX);
 
 	len = 0;
-	while (len >= 0 && seq < next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
-		int textlen = msg_print_text(msg, true, time, text,
-					     LOG_LINE_MAX + PREFIX_MAX);
+	prb_for_each_record(seq, prb, seq, &r) {
+		int textlen;
 
-		idx = log_next(idx);
-		seq++;
+		textlen = record_print_text(&r, true, time);
+
+		if (len + textlen > size) {
+			seq--;
+			break;
+		}
 
 		logbuf_unlock_irq();
 		if (copy_to_user(buf + len, text, textlen))
@@ -1503,17 +1586,12 @@
 			len += textlen;
 		logbuf_lock_irq();
 
-		if (seq < log_first_seq) {
-			/* messages are gone, move to next one */
-			seq = log_first_seq;
-			idx = log_first_idx;
-		}
+		if (len < 0)
+			break;
 	}
 
-	if (clear) {
-		clear_seq = log_next_seq;
-		clear_idx = log_next_idx;
-	}
+	if (clear)
+		clear_seq = seq;
 	logbuf_unlock_irq();
 
 	kfree(text);
@@ -1523,13 +1601,13 @@
 static void syslog_clear(void)
 {
 	logbuf_lock_irq();
-	clear_seq = log_next_seq;
-	clear_idx = log_next_idx;
+	clear_seq = prb_next_seq(prb);
 	logbuf_unlock_irq();
 }
 
 int do_syslog(int type, char __user *buf, int len, int source)
 {
+	struct printk_info info;
 	bool clear = false;
 	static int saved_console_loglevel = LOGLEVEL_DEFAULT;
 	int error;
@@ -1551,7 +1629,7 @@
 		if (!access_ok(buf, len))
 			return -EFAULT;
 		error = wait_event_interruptible(log_wait,
-						 syslog_seq != log_next_seq);
+				prb_read_valid(prb, syslog_seq, NULL));
 		if (error)
 			return error;
 		error = syslog_print(buf, len);
@@ -1559,7 +1637,7 @@
 	/* Read/clear last kernel messages */
 	case SYSLOG_ACTION_READ_CLEAR:
 		clear = true;
-		/* FALL THRU */
+		fallthrough;
 	/* Read last kernel messages */
 	case SYSLOG_ACTION_READ_ALL:
 		if (!buf || len < 0)
@@ -1600,10 +1678,14 @@
 	/* Number of chars in the log buffer */
 	case SYSLOG_ACTION_SIZE_UNREAD:
 		logbuf_lock_irq();
-		if (syslog_seq < log_first_seq) {
+		if (!prb_read_valid_info(prb, syslog_seq, &info, NULL)) {
+			/* No unread messages. */
+			logbuf_unlock_irq();
+			return 0;
+		}
+		if (info.seq != syslog_seq) {
 			/* messages are gone, move to first one */
-			syslog_seq = log_first_seq;
-			syslog_idx = log_first_idx;
+			syslog_seq = info.seq;
 			syslog_partial = 0;
 		}
 		if (source == SYSLOG_FROM_PROC) {
@@ -1612,20 +1694,17 @@
 			 * for pending data, not the size; return the count of
 			 * records, not the length.
 			 */
-			error = log_next_seq - syslog_seq;
+			error = prb_next_seq(prb) - syslog_seq;
 		} else {
-			u64 seq = syslog_seq;
-			u32 idx = syslog_idx;
 			bool time = syslog_partial ? syslog_time : printk_time;
+			unsigned int line_count;
+			u64 seq;
 
-			while (seq < log_next_seq) {
-				struct printk_log *msg = log_from_idx(idx);
-
-				error += msg_print_text(msg, true, time, NULL,
-							0);
+			prb_for_each_info(syslog_seq, prb, seq, &info,
+					  &line_count) {
+				error += get_record_print_text_size(&info, line_count,
+								    true, time);
 				time = printk_time;
-				idx = log_next(idx);
-				seq++;
 			}
 			error -= syslog_partial;
 		}
@@ -1707,20 +1786,20 @@
 	raw_spin_unlock(&console_owner_lock);
 
 	if (!waiter) {
-		spin_release(&console_owner_dep_map, 1, _THIS_IP_);
+		spin_release(&console_owner_dep_map, _THIS_IP_);
 		return 0;
 	}
 
 	/* The waiter is now free to continue */
 	WRITE_ONCE(console_waiter, false);
 
-	spin_release(&console_owner_dep_map, 1, _THIS_IP_);
+	spin_release(&console_owner_dep_map, _THIS_IP_);
 
 	/*
 	 * Hand off console_lock to waiter. The waiter will perform
 	 * the up(). After this, the waiter is the console_lock owner.
 	 */
-	mutex_release(&console_lock_dep_map, 1, _THIS_IP_);
+	mutex_release(&console_lock_dep_map, _THIS_IP_);
 	return 1;
 }
 
@@ -1774,7 +1853,7 @@
 	/* Owner will clear console_waiter on hand off */
 	while (READ_ONCE(console_waiter))
 		cpu_relax();
-	spin_release(&console_owner_dep_map, 1, _THIS_IP_);
+	spin_release(&console_owner_dep_map, _THIS_IP_);
 
 	printk_safe_exit_irqrestore(flags);
 	/*
@@ -1796,6 +1875,8 @@
 static void call_console_drivers(const char *ext_text, size_t ext_len,
 				 const char *text, size_t len)
 {
+	static char dropped_text[64];
+	size_t dropped_len = 0;
 	struct console *con;
 
 	trace_console_rcuidle(text, len);
@@ -1803,6 +1884,13 @@
 	if (!console_drivers)
 		return;
 
+	if (console_dropped) {
+		dropped_len = snprintf(dropped_text, sizeof(dropped_text),
+				       "** %lu printk messages dropped **\n",
+				       console_dropped);
+		console_dropped = 0;
+	}
+
 	for_each_console(con) {
 		if (exclusive_console && con != exclusive_console)
 			continue;
@@ -1815,8 +1903,11 @@
 			continue;
 		if (con->flags & CON_EXTENDED)
 			con->write(con, ext_text, ext_len);
-		else
+		else {
+			if (dropped_len)
+				con->write(con, dropped_text, dropped_len);
 			con->write(con, text, len);
+		}
 	}
 }
 
@@ -1840,97 +1931,38 @@
 		0x80000000 + raw_smp_processor_id();
 }
 
-/*
- * Continuation lines are buffered, and not committed to the record buffer
- * until the line is complete, or a race forces it. The line fragments
- * though, are printed immediately to the consoles to ensure everything has
- * reached the console in case of a kernel crash.
- */
-static struct cont {
-	char buf[LOG_LINE_MAX];
-	size_t len;			/* length == 0 means unused buffer */
-	u32 caller_id;			/* printk_caller_id() of first print */
-	u64 ts_nsec;			/* time of first print */
-	u8 level;			/* log level of first message */
-	u8 facility;			/* log facility of first message */
-	enum log_flags flags;		/* prefix, newline flags */
-} cont;
-
-static void cont_flush(void)
-{
-	if (cont.len == 0)
-		return;
-
-	log_store(cont.caller_id, cont.facility, cont.level, cont.flags,
-		  cont.ts_nsec, NULL, 0, cont.buf, cont.len);
-	cont.len = 0;
-}
-
-static bool cont_add(u32 caller_id, int facility, int level,
-		     enum log_flags flags, const char *text, size_t len)
-{
-	/* If the line gets too long, split it up in separate records. */
-	if (cont.len + len > sizeof(cont.buf)) {
-		cont_flush();
-		return false;
-	}
-
-	if (!cont.len) {
-		cont.facility = facility;
-		cont.level = level;
-		cont.caller_id = caller_id;
-		cont.ts_nsec = local_clock();
-		cont.flags = flags;
-	}
-
-	memcpy(cont.buf + cont.len, text, len);
-	cont.len += len;
-
-	// The original flags come from the first line,
-	// but later continuations can add a newline.
-	if (flags & LOG_NEWLINE) {
-		cont.flags |= LOG_NEWLINE;
-		cont_flush();
-	}
-
-	return true;
-}
-
-static size_t log_output(int facility, int level, enum log_flags lflags, const char *dict, size_t dictlen, char *text, size_t text_len)
+static size_t log_output(int facility, int level, enum log_flags lflags,
+			 const struct dev_printk_info *dev_info,
+			 char *text, size_t text_len)
 {
 	const u32 caller_id = printk_caller_id();
 
-	/*
-	 * If an earlier line was buffered, and we're a continuation
-	 * write from the same context, try to add it to the buffer.
-	 */
-	if (cont.len) {
-		if (cont.caller_id == caller_id && (lflags & LOG_CONT)) {
-			if (cont_add(caller_id, facility, level, lflags, text, text_len))
-				return text_len;
-		}
-		/* Otherwise, make sure it's flushed */
-		cont_flush();
-	}
+	if (lflags & LOG_CONT) {
+		struct prb_reserved_entry e;
+		struct printk_record r;
 
-	/* Skip empty continuation lines that couldn't be added - they just flush */
-	if (!text_len && (lflags & LOG_CONT))
-		return 0;
-
-	/* If it doesn't end in a newline, try to buffer the current line */
-	if (!(lflags & LOG_NEWLINE)) {
-		if (cont_add(caller_id, facility, level, lflags, text, text_len))
+		prb_rec_init_wr(&r, text_len);
+		if (prb_reserve_in_last(&e, prb, &r, caller_id, LOG_LINE_MAX)) {
+			memcpy(&r.text_buf[r.info->text_len], text, text_len);
+			r.info->text_len += text_len;
+			if (lflags & LOG_NEWLINE) {
+				r.info->flags |= LOG_NEWLINE;
+				prb_final_commit(&e);
+			} else {
+				prb_commit(&e);
+			}
 			return text_len;
+		}
 	}
 
 	/* Store it in the record log */
 	return log_store(caller_id, facility, level, lflags, 0,
-			 dict, dictlen, text, text_len);
+			 dev_info, text, text_len);
 }
 
 /* Must be called under logbuf_lock. */
 int vprintk_store(int facility, int level,
-		  const char *dict, size_t dictlen,
+		  const struct dev_printk_info *dev_info,
 		  const char *fmt, va_list args)
 {
 	static char textbuf[LOG_LINE_MAX];
@@ -1972,21 +2004,19 @@
 	if (level == LOGLEVEL_DEFAULT)
 		level = default_message_loglevel;
 
-	if (dict)
+	if (dev_info)
 		lflags |= LOG_NEWLINE;
 
-	return log_output(facility, level, lflags,
-			  dict, dictlen, text, text_len);
+	return log_output(facility, level, lflags, dev_info, text, text_len);
 }
 
 asmlinkage int vprintk_emit(int facility, int level,
-			    const char *dict, size_t dictlen,
+			    const struct dev_printk_info *dev_info,
 			    const char *fmt, va_list args)
 {
 	int printed_len;
-	bool in_sched = false, pending_output;
+	bool in_sched = false;
 	unsigned long flags;
-	u64 curr_log_seq;
 
 	/* Suppress unimportant messages after panic happens */
 	if (unlikely(suppress_printk))
@@ -2002,13 +2032,11 @@
 
 	/* This stops the holder of console_sem just where we want him */
 	logbuf_lock_irqsave(flags);
-	curr_log_seq = log_next_seq;
-	printed_len = vprintk_store(facility, level, dict, dictlen, fmt, args);
-	pending_output = (curr_log_seq != log_next_seq);
+	printed_len = vprintk_store(facility, level, dev_info, fmt, args);
 	logbuf_unlock_irqrestore(flags);
 
 	/* If called from the scheduler, we can not call up(). */
-	if (!in_sched && pending_output) {
+	if (!in_sched) {
 		/*
 		 * Disable preemption to avoid being preempted while holding
 		 * console_sem which would prevent anyone from printing to
@@ -2025,8 +2053,7 @@
 		preempt_enable();
 	}
 
-	if (pending_output)
-		wake_up_klogd();
+	wake_up_klogd();
 	return printed_len;
 }
 EXPORT_SYMBOL(vprintk_emit);
@@ -2039,18 +2066,7 @@
 
 int vprintk_default(const char *fmt, va_list args)
 {
-	int r;
-
-#ifdef CONFIG_KGDB_KDB
-	/* Allow to pass printk() to kdb but avoid a recursion. */
-	if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0)) {
-		r = vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args);
-		return r;
-	}
-#endif
-	r = vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
-
-	return r;
+	return vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, fmt, args);
 }
 EXPORT_SYMBOL_GPL(vprintk_default);
 
@@ -2094,30 +2110,31 @@
 #define PREFIX_MAX		0
 #define printk_time		false
 
+#define prb_read_valid(rb, seq, r)	false
+#define prb_first_valid_seq(rb)		0
+
 static u64 syslog_seq;
-static u32 syslog_idx;
 static u64 console_seq;
-static u32 console_idx;
 static u64 exclusive_console_stop_seq;
-static u64 log_first_seq;
-static u32 log_first_idx;
-static u64 log_next_seq;
-static char *log_text(const struct printk_log *msg) { return NULL; }
-static char *log_dict(const struct printk_log *msg) { return NULL; }
-static struct printk_log *log_from_idx(u32 idx) { return NULL; }
-static u32 log_next(u32 idx) { return 0; }
-static ssize_t msg_print_ext_header(char *buf, size_t size,
-				    struct printk_log *msg,
-				    u64 seq) { return 0; }
+static unsigned long console_dropped;
+
+static size_t record_print_text(const struct printk_record *r,
+				bool syslog, bool time)
+{
+	return 0;
+}
+static ssize_t info_print_ext_header(char *buf, size_t size,
+				     struct printk_info *info)
+{
+	return 0;
+}
 static ssize_t msg_print_ext_body(char *buf, size_t size,
-				  char *dict, size_t dict_len,
-				  char *text, size_t text_len) { return 0; }
+				  char *text, size_t text_len,
+				  struct dev_printk_info *dev_info) { return 0; }
 static void console_lock_spinning_enable(void) { }
 static int console_lock_spinning_disable_and_check(void) { return 0; }
 static void call_console_drivers(const char *ext_text, size_t ext_len,
 				 const char *text, size_t len) {}
-static size_t msg_print_text(const struct printk_log *msg, bool syslog,
-			     bool time, char *buf, size_t size) { return 0; }
 static bool suppress_message_printing(int level) { return false; }
 
 #endif /* CONFIG_PRINTK */
@@ -2143,7 +2160,7 @@
 #endif
 
 static int __add_preferred_console(char *name, int idx, char *options,
-				   char *brl_options)
+				   char *brl_options, bool user_specified)
 {
 	struct console_cmdline *c;
 	int i;
@@ -2158,6 +2175,8 @@
 		if (strcmp(c->name, name) == 0 && c->index == idx) {
 			if (!brl_options)
 				preferred_console = i;
+			if (user_specified)
+				c->user_specified = true;
 			return 0;
 		}
 	}
@@ -2167,6 +2186,7 @@
 		preferred_console = i;
 	strlcpy(c->name, name, sizeof(c->name));
 	c->options = options;
+	c->user_specified = user_specified;
 	braille_set_options(c, brl_options);
 
 	c->index = idx;
@@ -2193,8 +2213,15 @@
 	char *s, *options, *brl_options = NULL;
 	int idx;
 
-	if (str[0] == 0)
+	/*
+	 * console="" or console=null have been suggested as a way to
+	 * disable console output. Use ttynull that has been created
+	 * for exacly this purpose.
+	 */
+	if (str[0] == 0 || strcmp(str, "null") == 0) {
+		__add_preferred_console("ttynull", 0, NULL, NULL, true);
 		return 1;
+	}
 
 	if (_braille_console_setup(&str, &brl_options))
 		return 1;
@@ -2224,7 +2251,7 @@
 	idx = simple_strtoul(s, NULL, 10);
 	*s = 0;
 
-	__add_preferred_console(buf, idx, options, brl_options);
+	__add_preferred_console(buf, idx, options, brl_options, true);
 	console_set_on_cmdline = 1;
 	return 1;
 }
@@ -2245,7 +2272,7 @@
  */
 int add_preferred_console(char *name, int idx, char *options)
 {
-	return __add_preferred_console(name, idx, options, NULL);
+	return __add_preferred_console(name, idx, options, NULL, false);
 }
 
 bool console_suspend_enabled = true;
@@ -2401,12 +2428,16 @@
 	static char text[LOG_LINE_MAX + PREFIX_MAX];
 	unsigned long flags;
 	bool do_cond_resched, retry;
+	struct printk_info info;
+	struct printk_record r;
 
 	if (console_suspended) {
 		up_console_sem();
 		return;
 	}
 
+	prb_rec_init_rd(&r, &info, text, sizeof(text));
+
 	/*
 	 * Console drivers are called with interrupts disabled, so
 	 * @console_may_schedule should be cleared before; however, we may
@@ -2419,7 +2450,7 @@
 	 *
 	 * console_trylock() is not able to detect the preemptive
 	 * context reliably. Therefore the value must be stored before
-	 * and cleared after the the "again" goto label.
+	 * and cleared after the "again" goto label.
 	 */
 	do_cond_resched = console_may_schedule;
 again:
@@ -2437,35 +2468,26 @@
 	}
 
 	for (;;) {
-		struct printk_log *msg;
 		size_t ext_len = 0;
 		size_t len;
 
 		printk_safe_enter_irqsave(flags);
 		raw_spin_lock(&logbuf_lock);
-		if (console_seq < log_first_seq) {
-			len = sprintf(text,
-				      "** %llu printk messages dropped **\n",
-				      log_first_seq - console_seq);
-
-			/* messages are gone, move to first one */
-			console_seq = log_first_seq;
-			console_idx = log_first_idx;
-		} else {
-			len = 0;
-		}
 skip:
-		if (console_seq == log_next_seq)
+		if (!prb_read_valid(prb, console_seq, &r))
 			break;
 
-		msg = log_from_idx(console_idx);
-		if (suppress_message_printing(msg->level)) {
+		if (console_seq != r.info->seq) {
+			console_dropped += r.info->seq - console_seq;
+			console_seq = r.info->seq;
+		}
+
+		if (suppress_message_printing(r.info->level)) {
 			/*
 			 * Skip record we have buffered and already printed
 			 * directly to the console when we received it, and
 			 * record that has level above the console loglevel.
 			 */
-			console_idx = log_next(console_idx);
 			console_seq++;
 			goto skip;
 		}
@@ -2476,19 +2498,23 @@
 			exclusive_console = NULL;
 		}
 
-		len += msg_print_text(msg,
-				console_msg_format & MSG_FORMAT_SYSLOG,
-				printk_time, text + len, sizeof(text) - len);
+		/*
+		 * Handle extended console text first because later
+		 * record_print_text() will modify the record buffer in-place.
+		 */
 		if (nr_ext_console_drivers) {
-			ext_len = msg_print_ext_header(ext_text,
+			ext_len = info_print_ext_header(ext_text,
 						sizeof(ext_text),
-						msg, console_seq);
+						r.info);
 			ext_len += msg_print_ext_body(ext_text + ext_len,
 						sizeof(ext_text) - ext_len,
-						log_dict(msg), msg->dict_len,
-						log_text(msg), msg->text_len);
+						&r.text_buf[0],
+						r.info->text_len,
+						&r.info->dev_info);
 		}
-		console_idx = log_next(console_idx);
+		len = record_print_text(&r,
+				console_msg_format & MSG_FORMAT_SYSLOG,
+				printk_time);
 		console_seq++;
 		raw_spin_unlock(&logbuf_lock);
 
@@ -2528,7 +2554,7 @@
 	 * flush, no worries.
 	 */
 	raw_spin_lock(&logbuf_lock);
-	retry = console_seq != log_next_seq;
+	retry = prb_read_valid(prb, console_seq, NULL);
 	raw_spin_unlock(&logbuf_lock);
 	printk_safe_exit_irqrestore(flags);
 
@@ -2597,8 +2623,7 @@
 		unsigned long flags;
 
 		logbuf_lock_irqsave(flags);
-		console_seq = log_first_seq;
-		console_idx = log_first_idx;
+		console_seq = prb_first_valid_seq(prb);
 		logbuf_unlock_irqrestore(flags);
 	}
 	console_unlock();
@@ -2658,6 +2683,63 @@
 early_param("keep_bootcon", keep_bootcon_setup);
 
 /*
+ * This is called by register_console() to try to match
+ * the newly registered console with any of the ones selected
+ * by either the command line or add_preferred_console() and
+ * setup/enable it.
+ *
+ * Care need to be taken with consoles that are statically
+ * enabled such as netconsole
+ */
+static int try_enable_new_console(struct console *newcon, bool user_specified)
+{
+	struct console_cmdline *c;
+	int i, err;
+
+	for (i = 0, c = console_cmdline;
+	     i < MAX_CMDLINECONSOLES && c->name[0];
+	     i++, c++) {
+		if (c->user_specified != user_specified)
+			continue;
+		if (!newcon->match ||
+		    newcon->match(newcon, c->name, c->index, c->options) != 0) {
+			/* default matching */
+			BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
+			if (strcmp(c->name, newcon->name) != 0)
+				continue;
+			if (newcon->index >= 0 &&
+			    newcon->index != c->index)
+				continue;
+			if (newcon->index < 0)
+				newcon->index = c->index;
+
+			if (_braille_register_console(newcon, c))
+				return 0;
+
+			if (newcon->setup &&
+			    (err = newcon->setup(newcon, c->options)) != 0)
+				return err;
+		}
+		newcon->flags |= CON_ENABLED;
+		if (i == preferred_console) {
+			newcon->flags |= CON_CONSDEV;
+			has_preferred_console = true;
+		}
+		return 0;
+	}
+
+	/*
+	 * Some consoles, such as pstore and netconsole, can be enabled even
+	 * without matching. Accept the pre-enabled consoles only when match()
+	 * and setup() had a chance to be called.
+	 */
+	if (newcon->flags & CON_ENABLED && c->user_specified ==	user_specified)
+		return 0;
+
+	return -ENOENT;
+}
+
+/*
  * The console driver calls this routine during kernel initialization
  * to register the console printing procedure with printk() and to
  * print any messages that were printed by the kernel before the
@@ -2678,25 +2760,21 @@
  */
 void register_console(struct console *newcon)
 {
-	int i;
 	unsigned long flags;
 	struct console *bcon = NULL;
-	struct console_cmdline *c;
-	static bool has_preferred;
+	int err;
 
-	if (console_drivers)
-		for_each_console(bcon)
-			if (WARN(bcon == newcon,
-					"console '%s%d' already registered\n",
-					bcon->name, bcon->index))
-				return;
+	for_each_console(bcon) {
+		if (WARN(bcon == newcon, "console '%s%d' already registered\n",
+					 bcon->name, bcon->index))
+			return;
+	}
 
 	/*
 	 * before we register a new CON_BOOT console, make sure we don't
 	 * already have a valid console
 	 */
-	if (console_drivers && newcon->flags & CON_BOOT) {
-		/* find the last or real console */
+	if (newcon->flags & CON_BOOT) {
 		for_each_console(bcon) {
 			if (!(bcon->flags & CON_BOOT)) {
 				pr_info("Too late to register bootconsole %s%d\n",
@@ -2709,15 +2787,15 @@
 	if (console_drivers && console_drivers->flags & CON_BOOT)
 		bcon = console_drivers;
 
-	if (!has_preferred || bcon || !console_drivers)
-		has_preferred = preferred_console >= 0;
+	if (!has_preferred_console || bcon || !console_drivers)
+		has_preferred_console = preferred_console >= 0;
 
 	/*
 	 *	See if we want to use this console driver. If we
 	 *	didn't select a console we take the first one
 	 *	that registers here.
 	 */
-	if (!has_preferred) {
+	if (!has_preferred_console) {
 		if (newcon->index < 0)
 			newcon->index = 0;
 		if (newcon->setup == NULL ||
@@ -2725,47 +2803,20 @@
 			newcon->flags |= CON_ENABLED;
 			if (newcon->device) {
 				newcon->flags |= CON_CONSDEV;
-				has_preferred = true;
+				has_preferred_console = true;
 			}
 		}
 	}
 
-	/*
-	 *	See if this console matches one we selected on
-	 *	the command line.
-	 */
-	for (i = 0, c = console_cmdline;
-	     i < MAX_CMDLINECONSOLES && c->name[0];
-	     i++, c++) {
-		if (!newcon->match ||
-		    newcon->match(newcon, c->name, c->index, c->options) != 0) {
-			/* default matching */
-			BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
-			if (strcmp(c->name, newcon->name) != 0)
-				continue;
-			if (newcon->index >= 0 &&
-			    newcon->index != c->index)
-				continue;
-			if (newcon->index < 0)
-				newcon->index = c->index;
+	/* See if this console matches one we selected on the command line */
+	err = try_enable_new_console(newcon, true);
 
-			if (_braille_register_console(newcon, c))
-				return;
+	/* If not, try to match against the platform default(s) */
+	if (err == -ENOENT)
+		err = try_enable_new_console(newcon, false);
 
-			if (newcon->setup &&
-			    newcon->setup(newcon, c->options) != 0)
-				break;
-		}
-
-		newcon->flags |= CON_ENABLED;
-		if (i == preferred_console) {
-			newcon->flags |= CON_CONSDEV;
-			has_preferred = true;
-		}
-		break;
-	}
-
-	if (!(newcon->flags & CON_ENABLED))
+	/* printk() messages are not printed to the Braille console. */
+	if (err || newcon->flags & CON_BRL)
 		return;
 
 	/*
@@ -2787,6 +2838,8 @@
 		console_drivers = newcon;
 		if (newcon->next)
 			newcon->next->flags &= ~CON_CONSDEV;
+		/* Ensure this flag is always set for the head of the list */
+		newcon->flags |= CON_CONSDEV;
 	} else {
 		newcon->next = console_drivers->next;
 		console_drivers->next = newcon;
@@ -2813,7 +2866,6 @@
 		exclusive_console = newcon;
 		exclusive_console_stop_seq = console_seq;
 		console_seq = syslog_seq;
-		console_idx = syslog_idx;
 		logbuf_unlock_irqrestore(flags);
 	}
 	console_unlock();
@@ -2844,7 +2896,7 @@
 
 int unregister_console(struct console *console)
 {
-        struct console *a, *b;
+	struct console *con;
 	int res;
 
 	pr_info("%sconsole [%s%d] disabled\n",
@@ -2852,26 +2904,30 @@
 		console->name, console->index);
 
 	res = _braille_unregister_console(console);
-	if (res)
+	if (res < 0)
 		return res;
+	if (res > 0)
+		return 0;
 
-	res = 1;
+	res = -ENODEV;
 	console_lock();
 	if (console_drivers == console) {
 		console_drivers=console->next;
 		res = 0;
-	} else if (console_drivers) {
-		for (a=console_drivers->next, b=console_drivers ;
-		     a; b=a, a=b->next) {
-			if (a == console) {
-				b->next = a->next;
+	} else {
+		for_each_console(con) {
+			if (con->next == console) {
+				con->next = console->next;
 				res = 0;
 				break;
 			}
 		}
 	}
 
-	if (!res && (console->flags & CON_EXTENDED))
+	if (res)
+		goto out_disable_unlock;
+
+	if (console->flags & CON_EXTENDED)
 		nr_ext_console_drivers--;
 
 	/*
@@ -2884,6 +2940,16 @@
 	console->flags &= ~CON_ENABLED;
 	console_unlock();
 	console_sysfs_notify();
+
+	if (console->exit)
+		res = console->exit(console);
+
+	return res;
+
+out_disable_unlock:
+	console->flags &= ~CON_ENABLED;
+	console_unlock();
+
 	return res;
 }
 EXPORT_SYMBOL(unregister_console);
@@ -2992,7 +3058,7 @@
 
 static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = {
 	.func = wake_up_klogd_work_func,
-	.flags = IRQ_WORK_LAZY,
+	.flags = ATOMIC_INIT(IRQ_WORK_LAZY),
 };
 
 void wake_up_klogd(void)
@@ -3023,7 +3089,7 @@
 {
 	int r;
 
-	r = vprintk_emit(0, LOGLEVEL_SCHED, NULL, 0, fmt, args);
+	r = vprintk_emit(0, LOGLEVEL_SCHED, NULL, fmt, args);
 	defer_console_output();
 
 	return r;
@@ -3138,6 +3204,23 @@
 static bool always_kmsg_dump;
 module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
 
+const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason)
+{
+	switch (reason) {
+	case KMSG_DUMP_PANIC:
+		return "Panic";
+	case KMSG_DUMP_OOPS:
+		return "Oops";
+	case KMSG_DUMP_EMERG:
+		return "Emergency";
+	case KMSG_DUMP_SHUTDOWN:
+		return "Shutdown";
+	default:
+		return "Unknown";
+	}
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_reason_str);
+
 /**
  * kmsg_dump - dump kernel log to kernel message dumpers.
  * @reason: the reason (oops, panic etc) for dumping
@@ -3151,12 +3234,19 @@
 	struct kmsg_dumper *dumper;
 	unsigned long flags;
 
-	if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
-		return;
-
 	rcu_read_lock();
 	list_for_each_entry_rcu(dumper, &dump_list, list) {
-		if (dumper->max_reason && reason > dumper->max_reason)
+		enum kmsg_dump_reason max_reason = dumper->max_reason;
+
+		/*
+		 * If client has not provided a specific max_reason, default
+		 * to KMSG_DUMP_OOPS, unless always_kmsg_dump was set.
+		 */
+		if (max_reason == KMSG_DUMP_UNDEF) {
+			max_reason = always_kmsg_dump ? KMSG_DUMP_MAX :
+							KMSG_DUMP_OOPS;
+		}
+		if (reason > max_reason)
 			continue;
 
 		/* initialize iterator with data about the stored records */
@@ -3164,9 +3254,7 @@
 
 		logbuf_lock_irqsave(flags);
 		dumper->cur_seq = clear_seq;
-		dumper->cur_idx = clear_idx;
-		dumper->next_seq = log_next_seq;
-		dumper->next_idx = log_next_idx;
+		dumper->next_seq = prb_next_seq(prb);
 		logbuf_unlock_irqrestore(flags);
 
 		/* invoke dumper which will iterate over records */
@@ -3200,28 +3288,33 @@
 bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
 			       char *line, size_t size, size_t *len)
 {
-	struct printk_log *msg;
+	struct printk_info info;
+	unsigned int line_count;
+	struct printk_record r;
 	size_t l = 0;
 	bool ret = false;
 
+	prb_rec_init_rd(&r, &info, line, size);
+
 	if (!dumper->active)
 		goto out;
 
-	if (dumper->cur_seq < log_first_seq) {
-		/* messages are gone, move to first available one */
-		dumper->cur_seq = log_first_seq;
-		dumper->cur_idx = log_first_idx;
+	/* Read text or count text lines? */
+	if (line) {
+		if (!prb_read_valid(prb, dumper->cur_seq, &r))
+			goto out;
+		l = record_print_text(&r, syslog, printk_time);
+	} else {
+		if (!prb_read_valid_info(prb, dumper->cur_seq,
+					 &info, &line_count)) {
+			goto out;
+		}
+		l = get_record_print_text_size(&info, line_count, syslog,
+					       printk_time);
+
 	}
 
-	/* last entry */
-	if (dumper->cur_seq >= log_next_seq)
-		goto out;
-
-	msg = log_from_idx(dumper->cur_idx);
-	l = msg_print_text(msg, syslog, printk_time, line, size);
-
-	dumper->cur_idx = log_next(dumper->cur_idx);
-	dumper->cur_seq++;
+	dumper->cur_seq = r.info->seq + 1;
 	ret = true;
 out:
 	if (len)
@@ -3269,7 +3362,7 @@
  * @len: length of line placed into buffer
  *
  * Start at the end of the kmsg buffer and fill the provided buffer
- * with as many of the the *youngest* kmsg records that fit into it.
+ * with as many of the *youngest* kmsg records that fit into it.
  * If the buffer is large enough, all available kmsg records will be
  * copied with a single call.
  *
@@ -3282,23 +3375,27 @@
 bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 			  char *buf, size_t size, size_t *len)
 {
+	struct printk_info info;
+	unsigned int line_count;
+	struct printk_record r;
 	unsigned long flags;
 	u64 seq;
-	u32 idx;
 	u64 next_seq;
-	u32 next_idx;
 	size_t l = 0;
 	bool ret = false;
 	bool time = printk_time;
 
-	if (!dumper->active)
+	prb_rec_init_rd(&r, &info, buf, size);
+
+	if (!dumper->active || !buf || !size)
 		goto out;
 
 	logbuf_lock_irqsave(flags);
-	if (dumper->cur_seq < log_first_seq) {
-		/* messages are gone, move to first available one */
-		dumper->cur_seq = log_first_seq;
-		dumper->cur_idx = log_first_idx;
+	if (prb_read_valid_info(prb, dumper->cur_seq, &info, NULL)) {
+		if (info.seq != dumper->cur_seq) {
+			/* messages are gone, move to first available one */
+			dumper->cur_seq = info.seq;
+		}
 	}
 
 	/* last entry */
@@ -3309,41 +3406,41 @@
 
 	/* calculate length of entire buffer */
 	seq = dumper->cur_seq;
-	idx = dumper->cur_idx;
-	while (seq < dumper->next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
-
-		l += msg_print_text(msg, true, time, NULL, 0);
-		idx = log_next(idx);
-		seq++;
+	while (prb_read_valid_info(prb, seq, &info, &line_count)) {
+		if (r.info->seq >= dumper->next_seq)
+			break;
+		l += get_record_print_text_size(&info, line_count, syslog, time);
+		seq = r.info->seq + 1;
 	}
 
 	/* move first record forward until length fits into the buffer */
 	seq = dumper->cur_seq;
-	idx = dumper->cur_idx;
-	while (l >= size && seq < dumper->next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
-
-		l -= msg_print_text(msg, true, time, NULL, 0);
-		idx = log_next(idx);
-		seq++;
+	while (l >= size && prb_read_valid_info(prb, seq,
+						&info, &line_count)) {
+		if (r.info->seq >= dumper->next_seq)
+			break;
+		l -= get_record_print_text_size(&info, line_count, syslog, time);
+		seq = r.info->seq + 1;
 	}
 
 	/* last message in next interation */
 	next_seq = seq;
-	next_idx = idx;
 
+	/* actually read text into the buffer now */
 	l = 0;
-	while (seq < dumper->next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
+	while (prb_read_valid(prb, seq, &r)) {
+		if (r.info->seq >= dumper->next_seq)
+			break;
 
-		l += msg_print_text(msg, syslog, time, buf + l, size - l);
-		idx = log_next(idx);
-		seq++;
+		l += record_print_text(&r, syslog, time);
+
+		/* adjust record to store to remaining buffer space */
+		prb_rec_init_rd(&r, &info, buf + l, size - l);
+
+		seq = r.info->seq + 1;
 	}
 
 	dumper->next_seq = next_seq;
-	dumper->next_idx = next_idx;
 	ret = true;
 	logbuf_unlock_irqrestore(flags);
 out:
@@ -3354,7 +3451,7 @@
 EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
 
 /**
- * kmsg_dump_rewind_nolock - reset the interator (unlocked version)
+ * kmsg_dump_rewind_nolock - reset the iterator (unlocked version)
  * @dumper: registered kmsg dumper
  *
  * Reset the dumper's iterator so that kmsg_dump_get_line() and
@@ -3366,13 +3463,11 @@
 void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
 {
 	dumper->cur_seq = clear_seq;
-	dumper->cur_idx = clear_idx;
-	dumper->next_seq = log_next_seq;
-	dumper->next_idx = log_next_idx;
+	dumper->next_seq = prb_next_seq(prb);
 }
 
 /**
- * kmsg_dump_rewind - reset the interator
+ * kmsg_dump_rewind - reset the iterator
  * @dumper: registered kmsg dumper
  *
  * Reset the dumper's iterator so that kmsg_dump_get_line() and
diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
new file mode 100644
index 0000000..617dd63
--- /dev/null
+++ b/kernel/printk/printk_ringbuffer.c
@@ -0,0 +1,2084 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <linux/irqflags.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/bug.h>
+#include "printk_ringbuffer.h"
+
+/**
+ * DOC: printk_ringbuffer overview
+ *
+ * Data Structure
+ * --------------
+ * The printk_ringbuffer is made up of 3 internal ringbuffers:
+ *
+ *   desc_ring
+ *     A ring of descriptors and their meta data (such as sequence number,
+ *     timestamp, loglevel, etc.) as well as internal state information about
+ *     the record and logical positions specifying where in the other
+ *     ringbuffer the text strings are located.
+ *
+ *   text_data_ring
+ *     A ring of data blocks. A data block consists of an unsigned long
+ *     integer (ID) that maps to a desc_ring index followed by the text
+ *     string of the record.
+ *
+ * The internal state information of a descriptor is the key element to allow
+ * readers and writers to locklessly synchronize access to the data.
+ *
+ * Implementation
+ * --------------
+ *
+ * Descriptor Ring
+ * ~~~~~~~~~~~~~~~
+ * The descriptor ring is an array of descriptors. A descriptor contains
+ * essential meta data to track the data of a printk record using
+ * blk_lpos structs pointing to associated text data blocks (see
+ * "Data Rings" below). Each descriptor is assigned an ID that maps
+ * directly to index values of the descriptor array and has a state. The ID
+ * and the state are bitwise combined into a single descriptor field named
+ * @state_var, allowing ID and state to be synchronously and atomically
+ * updated.
+ *
+ * Descriptors have four states:
+ *
+ *   reserved
+ *     A writer is modifying the record.
+ *
+ *   committed
+ *     The record and all its data are written. A writer can reopen the
+ *     descriptor (transitioning it back to reserved), but in the committed
+ *     state the data is consistent.
+ *
+ *   finalized
+ *     The record and all its data are complete and available for reading. A
+ *     writer cannot reopen the descriptor.
+ *
+ *   reusable
+ *     The record exists, but its text and/or meta data may no longer be
+ *     available.
+ *
+ * Querying the @state_var of a record requires providing the ID of the
+ * descriptor to query. This can yield a possible fifth (pseudo) state:
+ *
+ *   miss
+ *     The descriptor being queried has an unexpected ID.
+ *
+ * The descriptor ring has a @tail_id that contains the ID of the oldest
+ * descriptor and @head_id that contains the ID of the newest descriptor.
+ *
+ * When a new descriptor should be created (and the ring is full), the tail
+ * descriptor is invalidated by first transitioning to the reusable state and
+ * then invalidating all tail data blocks up to and including the data blocks
+ * associated with the tail descriptor (for the text ring). Then
+ * @tail_id is advanced, followed by advancing @head_id. And finally the
+ * @state_var of the new descriptor is initialized to the new ID and reserved
+ * state.
+ *
+ * The @tail_id can only be advanced if the new @tail_id would be in the
+ * committed or reusable queried state. This makes it possible that a valid
+ * sequence number of the tail is always available.
+ *
+ * Descriptor Finalization
+ * ~~~~~~~~~~~~~~~~~~~~~~~
+ * When a writer calls the commit function prb_commit(), record data is
+ * fully stored and is consistent within the ringbuffer. However, a writer can
+ * reopen that record, claiming exclusive access (as with prb_reserve()), and
+ * modify that record. When finished, the writer must again commit the record.
+ *
+ * In order for a record to be made available to readers (and also become
+ * recyclable for writers), it must be finalized. A finalized record cannot be
+ * reopened and can never become "unfinalized". Record finalization can occur
+ * in three different scenarios:
+ *
+ *   1) A writer can simultaneously commit and finalize its record by calling
+ *      prb_final_commit() instead of prb_commit().
+ *
+ *   2) When a new record is reserved and the previous record has been
+ *      committed via prb_commit(), that previous record is automatically
+ *      finalized.
+ *
+ *   3) When a record is committed via prb_commit() and a newer record
+ *      already exists, the record being committed is automatically finalized.
+ *
+ * Data Ring
+ * ~~~~~~~~~
+ * The text data ring is a byte array composed of data blocks. Data blocks are
+ * referenced by blk_lpos structs that point to the logical position of the
+ * beginning of a data block and the beginning of the next adjacent data
+ * block. Logical positions are mapped directly to index values of the byte
+ * array ringbuffer.
+ *
+ * Each data block consists of an ID followed by the writer data. The ID is
+ * the identifier of a descriptor that is associated with the data block. A
+ * given data block is considered valid if all of the following conditions
+ * are met:
+ *
+ *   1) The descriptor associated with the data block is in the committed
+ *      or finalized queried state.
+ *
+ *   2) The blk_lpos struct within the descriptor associated with the data
+ *      block references back to the same data block.
+ *
+ *   3) The data block is within the head/tail logical position range.
+ *
+ * If the writer data of a data block would extend beyond the end of the
+ * byte array, only the ID of the data block is stored at the logical
+ * position and the full data block (ID and writer data) is stored at the
+ * beginning of the byte array. The referencing blk_lpos will point to the
+ * ID before the wrap and the next data block will be at the logical
+ * position adjacent the full data block after the wrap.
+ *
+ * Data rings have a @tail_lpos that points to the beginning of the oldest
+ * data block and a @head_lpos that points to the logical position of the
+ * next (not yet existing) data block.
+ *
+ * When a new data block should be created (and the ring is full), tail data
+ * blocks will first be invalidated by putting their associated descriptors
+ * into the reusable state and then pushing the @tail_lpos forward beyond
+ * them. Then the @head_lpos is pushed forward and is associated with a new
+ * descriptor. If a data block is not valid, the @tail_lpos cannot be
+ * advanced beyond it.
+ *
+ * Info Array
+ * ~~~~~~~~~~
+ * The general meta data of printk records are stored in printk_info structs,
+ * stored in an array with the same number of elements as the descriptor ring.
+ * Each info corresponds to the descriptor of the same index in the
+ * descriptor ring. Info validity is confirmed by evaluating the corresponding
+ * descriptor before and after loading the info.
+ *
+ * Usage
+ * -----
+ * Here are some simple examples demonstrating writers and readers. For the
+ * examples a global ringbuffer (test_rb) is available (which is not the
+ * actual ringbuffer used by printk)::
+ *
+ *	DEFINE_PRINTKRB(test_rb, 15, 5);
+ *
+ * This ringbuffer allows up to 32768 records (2 ^ 15) and has a size of
+ * 1 MiB (2 ^ (15 + 5)) for text data.
+ *
+ * Sample writer code::
+ *
+ *	const char *textstr = "message text";
+ *	struct prb_reserved_entry e;
+ *	struct printk_record r;
+ *
+ *	// specify how much to allocate
+ *	prb_rec_init_wr(&r, strlen(textstr) + 1);
+ *
+ *	if (prb_reserve(&e, &test_rb, &r)) {
+ *		snprintf(r.text_buf, r.text_buf_size, "%s", textstr);
+ *
+ *		r.info->text_len = strlen(textstr);
+ *		r.info->ts_nsec = local_clock();
+ *		r.info->caller_id = printk_caller_id();
+ *
+ *		// commit and finalize the record
+ *		prb_final_commit(&e);
+ *	}
+ *
+ * Note that additional writer functions are available to extend a record
+ * after it has been committed but not yet finalized. This can be done as
+ * long as no new records have been reserved and the caller is the same.
+ *
+ * Sample writer code (record extending)::
+ *
+ *		// alternate rest of previous example
+ *
+ *		r.info->text_len = strlen(textstr);
+ *		r.info->ts_nsec = local_clock();
+ *		r.info->caller_id = printk_caller_id();
+ *
+ *		// commit the record (but do not finalize yet)
+ *		prb_commit(&e);
+ *	}
+ *
+ *	...
+ *
+ *	// specify additional 5 bytes text space to extend
+ *	prb_rec_init_wr(&r, 5);
+ *
+ *	// try to extend, but only if it does not exceed 32 bytes
+ *	if (prb_reserve_in_last(&e, &test_rb, &r, printk_caller_id()), 32) {
+ *		snprintf(&r.text_buf[r.info->text_len],
+ *			 r.text_buf_size - r.info->text_len, "hello");
+ *
+ *		r.info->text_len += 5;
+ *
+ *		// commit and finalize the record
+ *		prb_final_commit(&e);
+ *	}
+ *
+ * Sample reader code::
+ *
+ *	struct printk_info info;
+ *	struct printk_record r;
+ *	char text_buf[32];
+ *	u64 seq;
+ *
+ *	prb_rec_init_rd(&r, &info, &text_buf[0], sizeof(text_buf));
+ *
+ *	prb_for_each_record(0, &test_rb, &seq, &r) {
+ *		if (info.seq != seq)
+ *			pr_warn("lost %llu records\n", info.seq - seq);
+ *
+ *		if (info.text_len > r.text_buf_size) {
+ *			pr_warn("record %llu text truncated\n", info.seq);
+ *			text_buf[r.text_buf_size - 1] = 0;
+ *		}
+ *
+ *		pr_info("%llu: %llu: %s\n", info.seq, info.ts_nsec,
+ *			&text_buf[0]);
+ *	}
+ *
+ * Note that additional less convenient reader functions are available to
+ * allow complex record access.
+ *
+ * ABA Issues
+ * ~~~~~~~~~~
+ * To help avoid ABA issues, descriptors are referenced by IDs (array index
+ * values combined with tagged bits counting array wraps) and data blocks are
+ * referenced by logical positions (array index values combined with tagged
+ * bits counting array wraps). However, on 32-bit systems the number of
+ * tagged bits is relatively small such that an ABA incident is (at least
+ * theoretically) possible. For example, if 4 million maximally sized (1KiB)
+ * printk messages were to occur in NMI context on a 32-bit system, the
+ * interrupted context would not be able to recognize that the 32-bit integer
+ * completely wrapped and thus represents a different data block than the one
+ * the interrupted context expects.
+ *
+ * To help combat this possibility, additional state checking is performed
+ * (such as using cmpxchg() even though set() would suffice). These extra
+ * checks are commented as such and will hopefully catch any ABA issue that
+ * a 32-bit system might experience.
+ *
+ * Memory Barriers
+ * ~~~~~~~~~~~~~~~
+ * Multiple memory barriers are used. To simplify proving correctness and
+ * generating litmus tests, lines of code related to memory barriers
+ * (loads, stores, and the associated memory barriers) are labeled::
+ *
+ *	LMM(function:letter)
+ *
+ * Comments reference the labels using only the "function:letter" part.
+ *
+ * The memory barrier pairs and their ordering are:
+ *
+ *   desc_reserve:D / desc_reserve:B
+ *     push descriptor tail (id), then push descriptor head (id)
+ *
+ *   desc_reserve:D / data_push_tail:B
+ *     push data tail (lpos), then set new descriptor reserved (state)
+ *
+ *   desc_reserve:D / desc_push_tail:C
+ *     push descriptor tail (id), then set new descriptor reserved (state)
+ *
+ *   desc_reserve:D / prb_first_seq:C
+ *     push descriptor tail (id), then set new descriptor reserved (state)
+ *
+ *   desc_reserve:F / desc_read:D
+ *     set new descriptor id and reserved (state), then allow writer changes
+ *
+ *   data_alloc:A (or data_realloc:A) / desc_read:D
+ *     set old descriptor reusable (state), then modify new data block area
+ *
+ *   data_alloc:A (or data_realloc:A) / data_push_tail:B
+ *     push data tail (lpos), then modify new data block area
+ *
+ *   _prb_commit:B / desc_read:B
+ *     store writer changes, then set new descriptor committed (state)
+ *
+ *   desc_reopen_last:A / _prb_commit:B
+ *     set descriptor reserved (state), then read descriptor data
+ *
+ *   _prb_commit:B / desc_reserve:D
+ *     set new descriptor committed (state), then check descriptor head (id)
+ *
+ *   data_push_tail:D / data_push_tail:A
+ *     set descriptor reusable (state), then push data tail (lpos)
+ *
+ *   desc_push_tail:B / desc_reserve:D
+ *     set descriptor reusable (state), then push descriptor tail (id)
+ */
+
+#define DATA_SIZE(data_ring)		_DATA_SIZE((data_ring)->size_bits)
+#define DATA_SIZE_MASK(data_ring)	(DATA_SIZE(data_ring) - 1)
+
+#define DESCS_COUNT(desc_ring)		_DESCS_COUNT((desc_ring)->count_bits)
+#define DESCS_COUNT_MASK(desc_ring)	(DESCS_COUNT(desc_ring) - 1)
+
+/* Determine the data array index from a logical position. */
+#define DATA_INDEX(data_ring, lpos)	((lpos) & DATA_SIZE_MASK(data_ring))
+
+/* Determine the desc array index from an ID or sequence number. */
+#define DESC_INDEX(desc_ring, n)	((n) & DESCS_COUNT_MASK(desc_ring))
+
+/* Determine how many times the data array has wrapped. */
+#define DATA_WRAPS(data_ring, lpos)	((lpos) >> (data_ring)->size_bits)
+
+/* Determine if a logical position refers to a data-less block. */
+#define LPOS_DATALESS(lpos)		((lpos) & 1UL)
+#define BLK_DATALESS(blk)		(LPOS_DATALESS((blk)->begin) && \
+					 LPOS_DATALESS((blk)->next))
+
+/* Get the logical position at index 0 of the current wrap. */
+#define DATA_THIS_WRAP_START_LPOS(data_ring, lpos) \
+((lpos) & ~DATA_SIZE_MASK(data_ring))
+
+/* Get the ID for the same index of the previous wrap as the given ID. */
+#define DESC_ID_PREV_WRAP(desc_ring, id) \
+DESC_ID((id) - DESCS_COUNT(desc_ring))
+
+/*
+ * A data block: mapped directly to the beginning of the data block area
+ * specified as a logical position within the data ring.
+ *
+ * @id:   the ID of the associated descriptor
+ * @data: the writer data
+ *
+ * Note that the size of a data block is only known by its associated
+ * descriptor.
+ */
+struct prb_data_block {
+	unsigned long	id;
+	char		data[];
+};
+
+/*
+ * Return the descriptor associated with @n. @n can be either a
+ * descriptor ID or a sequence number.
+ */
+static struct prb_desc *to_desc(struct prb_desc_ring *desc_ring, u64 n)
+{
+	return &desc_ring->descs[DESC_INDEX(desc_ring, n)];
+}
+
+/*
+ * Return the printk_info associated with @n. @n can be either a
+ * descriptor ID or a sequence number.
+ */
+static struct printk_info *to_info(struct prb_desc_ring *desc_ring, u64 n)
+{
+	return &desc_ring->infos[DESC_INDEX(desc_ring, n)];
+}
+
+static struct prb_data_block *to_block(struct prb_data_ring *data_ring,
+				       unsigned long begin_lpos)
+{
+	return (void *)&data_ring->data[DATA_INDEX(data_ring, begin_lpos)];
+}
+
+/*
+ * Increase the data size to account for data block meta data plus any
+ * padding so that the adjacent data block is aligned on the ID size.
+ */
+static unsigned int to_blk_size(unsigned int size)
+{
+	struct prb_data_block *db = NULL;
+
+	size += sizeof(*db);
+	size = ALIGN(size, sizeof(db->id));
+	return size;
+}
+
+/*
+ * Sanity checker for reserve size. The ringbuffer code assumes that a data
+ * block does not exceed the maximum possible size that could fit within the
+ * ringbuffer. This function provides that basic size check so that the
+ * assumption is safe.
+ */
+static bool data_check_size(struct prb_data_ring *data_ring, unsigned int size)
+{
+	struct prb_data_block *db = NULL;
+
+	if (size == 0)
+		return true;
+
+	/*
+	 * Ensure the alignment padded size could possibly fit in the data
+	 * array. The largest possible data block must still leave room for
+	 * at least the ID of the next block.
+	 */
+	size = to_blk_size(size);
+	if (size > DATA_SIZE(data_ring) - sizeof(db->id))
+		return false;
+
+	return true;
+}
+
+/* Query the state of a descriptor. */
+static enum desc_state get_desc_state(unsigned long id,
+				      unsigned long state_val)
+{
+	if (id != DESC_ID(state_val))
+		return desc_miss;
+
+	return DESC_STATE(state_val);
+}
+
+/*
+ * Get a copy of a specified descriptor and return its queried state. If the
+ * descriptor is in an inconsistent state (miss or reserved), the caller can
+ * only expect the descriptor's @state_var field to be valid.
+ *
+ * The sequence number and caller_id can be optionally retrieved. Like all
+ * non-state_var data, they are only valid if the descriptor is in a
+ * consistent state.
+ */
+static enum desc_state desc_read(struct prb_desc_ring *desc_ring,
+				 unsigned long id, struct prb_desc *desc_out,
+				 u64 *seq_out, u32 *caller_id_out)
+{
+	struct printk_info *info = to_info(desc_ring, id);
+	struct prb_desc *desc = to_desc(desc_ring, id);
+	atomic_long_t *state_var = &desc->state_var;
+	enum desc_state d_state;
+	unsigned long state_val;
+
+	/* Check the descriptor state. */
+	state_val = atomic_long_read(state_var); /* LMM(desc_read:A) */
+	d_state = get_desc_state(id, state_val);
+	if (d_state == desc_miss || d_state == desc_reserved) {
+		/*
+		 * The descriptor is in an inconsistent state. Set at least
+		 * @state_var so that the caller can see the details of
+		 * the inconsistent state.
+		 */
+		goto out;
+	}
+
+	/*
+	 * Guarantee the state is loaded before copying the descriptor
+	 * content. This avoids copying obsolete descriptor content that might
+	 * not apply to the descriptor state. This pairs with _prb_commit:B.
+	 *
+	 * Memory barrier involvement:
+	 *
+	 * If desc_read:A reads from _prb_commit:B, then desc_read:C reads
+	 * from _prb_commit:A.
+	 *
+	 * Relies on:
+	 *
+	 * WMB from _prb_commit:A to _prb_commit:B
+	 *    matching
+	 * RMB from desc_read:A to desc_read:C
+	 */
+	smp_rmb(); /* LMM(desc_read:B) */
+
+	/*
+	 * Copy the descriptor data. The data is not valid until the
+	 * state has been re-checked. A memcpy() for all of @desc
+	 * cannot be used because of the atomic_t @state_var field.
+	 */
+	memcpy(&desc_out->text_blk_lpos, &desc->text_blk_lpos,
+	       sizeof(desc_out->text_blk_lpos)); /* LMM(desc_read:C) */
+	if (seq_out)
+		*seq_out = info->seq; /* also part of desc_read:C */
+	if (caller_id_out)
+		*caller_id_out = info->caller_id; /* also part of desc_read:C */
+
+	/*
+	 * 1. Guarantee the descriptor content is loaded before re-checking
+	 *    the state. This avoids reading an obsolete descriptor state
+	 *    that may not apply to the copied content. This pairs with
+	 *    desc_reserve:F.
+	 *
+	 *    Memory barrier involvement:
+	 *
+	 *    If desc_read:C reads from desc_reserve:G, then desc_read:E
+	 *    reads from desc_reserve:F.
+	 *
+	 *    Relies on:
+	 *
+	 *    WMB from desc_reserve:F to desc_reserve:G
+	 *       matching
+	 *    RMB from desc_read:C to desc_read:E
+	 *
+	 * 2. Guarantee the record data is loaded before re-checking the
+	 *    state. This avoids reading an obsolete descriptor state that may
+	 *    not apply to the copied data. This pairs with data_alloc:A and
+	 *    data_realloc:A.
+	 *
+	 *    Memory barrier involvement:
+	 *
+	 *    If copy_data:A reads from data_alloc:B, then desc_read:E
+	 *    reads from desc_make_reusable:A.
+	 *
+	 *    Relies on:
+	 *
+	 *    MB from desc_make_reusable:A to data_alloc:B
+	 *       matching
+	 *    RMB from desc_read:C to desc_read:E
+	 *
+	 *    Note: desc_make_reusable:A and data_alloc:B can be different
+	 *          CPUs. However, the data_alloc:B CPU (which performs the
+	 *          full memory barrier) must have previously seen
+	 *          desc_make_reusable:A.
+	 */
+	smp_rmb(); /* LMM(desc_read:D) */
+
+	/*
+	 * The data has been copied. Return the current descriptor state,
+	 * which may have changed since the load above.
+	 */
+	state_val = atomic_long_read(state_var); /* LMM(desc_read:E) */
+	d_state = get_desc_state(id, state_val);
+out:
+	atomic_long_set(&desc_out->state_var, state_val);
+	return d_state;
+}
+
+/*
+ * Take a specified descriptor out of the finalized state by attempting
+ * the transition from finalized to reusable. Either this context or some
+ * other context will have been successful.
+ */
+static void desc_make_reusable(struct prb_desc_ring *desc_ring,
+			       unsigned long id)
+{
+	unsigned long val_finalized = DESC_SV(id, desc_finalized);
+	unsigned long val_reusable = DESC_SV(id, desc_reusable);
+	struct prb_desc *desc = to_desc(desc_ring, id);
+	atomic_long_t *state_var = &desc->state_var;
+
+	atomic_long_cmpxchg_relaxed(state_var, val_finalized,
+				    val_reusable); /* LMM(desc_make_reusable:A) */
+}
+
+/*
+ * Given the text data ring, put the associated descriptor of each
+ * data block from @lpos_begin until @lpos_end into the reusable state.
+ *
+ * If there is any problem making the associated descriptor reusable, either
+ * the descriptor has not yet been finalized or another writer context has
+ * already pushed the tail lpos past the problematic data block. Regardless,
+ * on error the caller can re-load the tail lpos to determine the situation.
+ */
+static bool data_make_reusable(struct printk_ringbuffer *rb,
+			       struct prb_data_ring *data_ring,
+			       unsigned long lpos_begin,
+			       unsigned long lpos_end,
+			       unsigned long *lpos_out)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	struct prb_data_block *blk;
+	enum desc_state d_state;
+	struct prb_desc desc;
+	struct prb_data_blk_lpos *blk_lpos = &desc.text_blk_lpos;
+	unsigned long id;
+
+	/* Loop until @lpos_begin has advanced to or beyond @lpos_end. */
+	while ((lpos_end - lpos_begin) - 1 < DATA_SIZE(data_ring)) {
+		blk = to_block(data_ring, lpos_begin);
+
+		/*
+		 * Load the block ID from the data block. This is a data race
+		 * against a writer that may have newly reserved this data
+		 * area. If the loaded value matches a valid descriptor ID,
+		 * the blk_lpos of that descriptor will be checked to make
+		 * sure it points back to this data block. If the check fails,
+		 * the data area has been recycled by another writer.
+		 */
+		id = blk->id; /* LMM(data_make_reusable:A) */
+
+		d_state = desc_read(desc_ring, id, &desc,
+				    NULL, NULL); /* LMM(data_make_reusable:B) */
+
+		switch (d_state) {
+		case desc_miss:
+		case desc_reserved:
+		case desc_committed:
+			return false;
+		case desc_finalized:
+			/*
+			 * This data block is invalid if the descriptor
+			 * does not point back to it.
+			 */
+			if (blk_lpos->begin != lpos_begin)
+				return false;
+			desc_make_reusable(desc_ring, id);
+			break;
+		case desc_reusable:
+			/*
+			 * This data block is invalid if the descriptor
+			 * does not point back to it.
+			 */
+			if (blk_lpos->begin != lpos_begin)
+				return false;
+			break;
+		}
+
+		/* Advance @lpos_begin to the next data block. */
+		lpos_begin = blk_lpos->next;
+	}
+
+	*lpos_out = lpos_begin;
+	return true;
+}
+
+/*
+ * Advance the data ring tail to at least @lpos. This function puts
+ * descriptors into the reusable state if the tail is pushed beyond
+ * their associated data block.
+ */
+static bool data_push_tail(struct printk_ringbuffer *rb,
+			   struct prb_data_ring *data_ring,
+			   unsigned long lpos)
+{
+	unsigned long tail_lpos_new;
+	unsigned long tail_lpos;
+	unsigned long next_lpos;
+
+	/* If @lpos is from a data-less block, there is nothing to do. */
+	if (LPOS_DATALESS(lpos))
+		return true;
+
+	/*
+	 * Any descriptor states that have transitioned to reusable due to the
+	 * data tail being pushed to this loaded value will be visible to this
+	 * CPU. This pairs with data_push_tail:D.
+	 *
+	 * Memory barrier involvement:
+	 *
+	 * If data_push_tail:A reads from data_push_tail:D, then this CPU can
+	 * see desc_make_reusable:A.
+	 *
+	 * Relies on:
+	 *
+	 * MB from desc_make_reusable:A to data_push_tail:D
+	 *    matches
+	 * READFROM from data_push_tail:D to data_push_tail:A
+	 *    thus
+	 * READFROM from desc_make_reusable:A to this CPU
+	 */
+	tail_lpos = atomic_long_read(&data_ring->tail_lpos); /* LMM(data_push_tail:A) */
+
+	/*
+	 * Loop until the tail lpos is at or beyond @lpos. This condition
+	 * may already be satisfied, resulting in no full memory barrier
+	 * from data_push_tail:D being performed. However, since this CPU
+	 * sees the new tail lpos, any descriptor states that transitioned to
+	 * the reusable state must already be visible.
+	 */
+	while ((lpos - tail_lpos) - 1 < DATA_SIZE(data_ring)) {
+		/*
+		 * Make all descriptors reusable that are associated with
+		 * data blocks before @lpos.
+		 */
+		if (!data_make_reusable(rb, data_ring, tail_lpos, lpos,
+					&next_lpos)) {
+			/*
+			 * 1. Guarantee the block ID loaded in
+			 *    data_make_reusable() is performed before
+			 *    reloading the tail lpos. The failed
+			 *    data_make_reusable() may be due to a newly
+			 *    recycled data area causing the tail lpos to
+			 *    have been previously pushed. This pairs with
+			 *    data_alloc:A and data_realloc:A.
+			 *
+			 *    Memory barrier involvement:
+			 *
+			 *    If data_make_reusable:A reads from data_alloc:B,
+			 *    then data_push_tail:C reads from
+			 *    data_push_tail:D.
+			 *
+			 *    Relies on:
+			 *
+			 *    MB from data_push_tail:D to data_alloc:B
+			 *       matching
+			 *    RMB from data_make_reusable:A to
+			 *    data_push_tail:C
+			 *
+			 *    Note: data_push_tail:D and data_alloc:B can be
+			 *          different CPUs. However, the data_alloc:B
+			 *          CPU (which performs the full memory
+			 *          barrier) must have previously seen
+			 *          data_push_tail:D.
+			 *
+			 * 2. Guarantee the descriptor state loaded in
+			 *    data_make_reusable() is performed before
+			 *    reloading the tail lpos. The failed
+			 *    data_make_reusable() may be due to a newly
+			 *    recycled descriptor causing the tail lpos to
+			 *    have been previously pushed. This pairs with
+			 *    desc_reserve:D.
+			 *
+			 *    Memory barrier involvement:
+			 *
+			 *    If data_make_reusable:B reads from
+			 *    desc_reserve:F, then data_push_tail:C reads
+			 *    from data_push_tail:D.
+			 *
+			 *    Relies on:
+			 *
+			 *    MB from data_push_tail:D to desc_reserve:F
+			 *       matching
+			 *    RMB from data_make_reusable:B to
+			 *    data_push_tail:C
+			 *
+			 *    Note: data_push_tail:D and desc_reserve:F can
+			 *          be different CPUs. However, the
+			 *          desc_reserve:F CPU (which performs the
+			 *          full memory barrier) must have previously
+			 *          seen data_push_tail:D.
+			 */
+			smp_rmb(); /* LMM(data_push_tail:B) */
+
+			tail_lpos_new = atomic_long_read(&data_ring->tail_lpos
+							); /* LMM(data_push_tail:C) */
+			if (tail_lpos_new == tail_lpos)
+				return false;
+
+			/* Another CPU pushed the tail. Try again. */
+			tail_lpos = tail_lpos_new;
+			continue;
+		}
+
+		/*
+		 * Guarantee any descriptor states that have transitioned to
+		 * reusable are stored before pushing the tail lpos. A full
+		 * memory barrier is needed since other CPUs may have made
+		 * the descriptor states reusable. This pairs with
+		 * data_push_tail:A.
+		 */
+		if (atomic_long_try_cmpxchg(&data_ring->tail_lpos, &tail_lpos,
+					    next_lpos)) { /* LMM(data_push_tail:D) */
+			break;
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Advance the desc ring tail. This function advances the tail by one
+ * descriptor, thus invalidating the oldest descriptor. Before advancing
+ * the tail, the tail descriptor is made reusable and all data blocks up to
+ * and including the descriptor's data block are invalidated (i.e. the data
+ * ring tail is pushed past the data block of the descriptor being made
+ * reusable).
+ */
+static bool desc_push_tail(struct printk_ringbuffer *rb,
+			   unsigned long tail_id)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	enum desc_state d_state;
+	struct prb_desc desc;
+
+	d_state = desc_read(desc_ring, tail_id, &desc, NULL, NULL);
+
+	switch (d_state) {
+	case desc_miss:
+		/*
+		 * If the ID is exactly 1 wrap behind the expected, it is
+		 * in the process of being reserved by another writer and
+		 * must be considered reserved.
+		 */
+		if (DESC_ID(atomic_long_read(&desc.state_var)) ==
+		    DESC_ID_PREV_WRAP(desc_ring, tail_id)) {
+			return false;
+		}
+
+		/*
+		 * The ID has changed. Another writer must have pushed the
+		 * tail and recycled the descriptor already. Success is
+		 * returned because the caller is only interested in the
+		 * specified tail being pushed, which it was.
+		 */
+		return true;
+	case desc_reserved:
+	case desc_committed:
+		return false;
+	case desc_finalized:
+		desc_make_reusable(desc_ring, tail_id);
+		break;
+	case desc_reusable:
+		break;
+	}
+
+	/*
+	 * Data blocks must be invalidated before their associated
+	 * descriptor can be made available for recycling. Invalidating
+	 * them later is not possible because there is no way to trust
+	 * data blocks once their associated descriptor is gone.
+	 */
+
+	if (!data_push_tail(rb, &rb->text_data_ring, desc.text_blk_lpos.next))
+		return false;
+
+	/*
+	 * Check the next descriptor after @tail_id before pushing the tail
+	 * to it because the tail must always be in a finalized or reusable
+	 * state. The implementation of prb_first_seq() relies on this.
+	 *
+	 * A successful read implies that the next descriptor is less than or
+	 * equal to @head_id so there is no risk of pushing the tail past the
+	 * head.
+	 */
+	d_state = desc_read(desc_ring, DESC_ID(tail_id + 1), &desc,
+			    NULL, NULL); /* LMM(desc_push_tail:A) */
+
+	if (d_state == desc_finalized || d_state == desc_reusable) {
+		/*
+		 * Guarantee any descriptor states that have transitioned to
+		 * reusable are stored before pushing the tail ID. This allows
+		 * verifying the recycled descriptor state. A full memory
+		 * barrier is needed since other CPUs may have made the
+		 * descriptor states reusable. This pairs with desc_reserve:D.
+		 */
+		atomic_long_cmpxchg(&desc_ring->tail_id, tail_id,
+				    DESC_ID(tail_id + 1)); /* LMM(desc_push_tail:B) */
+	} else {
+		/*
+		 * Guarantee the last state load from desc_read() is before
+		 * reloading @tail_id in order to see a new tail ID in the
+		 * case that the descriptor has been recycled. This pairs
+		 * with desc_reserve:D.
+		 *
+		 * Memory barrier involvement:
+		 *
+		 * If desc_push_tail:A reads from desc_reserve:F, then
+		 * desc_push_tail:D reads from desc_push_tail:B.
+		 *
+		 * Relies on:
+		 *
+		 * MB from desc_push_tail:B to desc_reserve:F
+		 *    matching
+		 * RMB from desc_push_tail:A to desc_push_tail:D
+		 *
+		 * Note: desc_push_tail:B and desc_reserve:F can be different
+		 *       CPUs. However, the desc_reserve:F CPU (which performs
+		 *       the full memory barrier) must have previously seen
+		 *       desc_push_tail:B.
+		 */
+		smp_rmb(); /* LMM(desc_push_tail:C) */
+
+		/*
+		 * Re-check the tail ID. The descriptor following @tail_id is
+		 * not in an allowed tail state. But if the tail has since
+		 * been moved by another CPU, then it does not matter.
+		 */
+		if (atomic_long_read(&desc_ring->tail_id) == tail_id) /* LMM(desc_push_tail:D) */
+			return false;
+	}
+
+	return true;
+}
+
+/* Reserve a new descriptor, invalidating the oldest if necessary. */
+static bool desc_reserve(struct printk_ringbuffer *rb, unsigned long *id_out)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	unsigned long prev_state_val;
+	unsigned long id_prev_wrap;
+	struct prb_desc *desc;
+	unsigned long head_id;
+	unsigned long id;
+
+	head_id = atomic_long_read(&desc_ring->head_id); /* LMM(desc_reserve:A) */
+
+	do {
+		id = DESC_ID(head_id + 1);
+		id_prev_wrap = DESC_ID_PREV_WRAP(desc_ring, id);
+
+		/*
+		 * Guarantee the head ID is read before reading the tail ID.
+		 * Since the tail ID is updated before the head ID, this
+		 * guarantees that @id_prev_wrap is never ahead of the tail
+		 * ID. This pairs with desc_reserve:D.
+		 *
+		 * Memory barrier involvement:
+		 *
+		 * If desc_reserve:A reads from desc_reserve:D, then
+		 * desc_reserve:C reads from desc_push_tail:B.
+		 *
+		 * Relies on:
+		 *
+		 * MB from desc_push_tail:B to desc_reserve:D
+		 *    matching
+		 * RMB from desc_reserve:A to desc_reserve:C
+		 *
+		 * Note: desc_push_tail:B and desc_reserve:D can be different
+		 *       CPUs. However, the desc_reserve:D CPU (which performs
+		 *       the full memory barrier) must have previously seen
+		 *       desc_push_tail:B.
+		 */
+		smp_rmb(); /* LMM(desc_reserve:B) */
+
+		if (id_prev_wrap == atomic_long_read(&desc_ring->tail_id
+						    )) { /* LMM(desc_reserve:C) */
+			/*
+			 * Make space for the new descriptor by
+			 * advancing the tail.
+			 */
+			if (!desc_push_tail(rb, id_prev_wrap))
+				return false;
+		}
+
+		/*
+		 * 1. Guarantee the tail ID is read before validating the
+		 *    recycled descriptor state. A read memory barrier is
+		 *    sufficient for this. This pairs with desc_push_tail:B.
+		 *
+		 *    Memory barrier involvement:
+		 *
+		 *    If desc_reserve:C reads from desc_push_tail:B, then
+		 *    desc_reserve:E reads from desc_make_reusable:A.
+		 *
+		 *    Relies on:
+		 *
+		 *    MB from desc_make_reusable:A to desc_push_tail:B
+		 *       matching
+		 *    RMB from desc_reserve:C to desc_reserve:E
+		 *
+		 *    Note: desc_make_reusable:A and desc_push_tail:B can be
+		 *          different CPUs. However, the desc_push_tail:B CPU
+		 *          (which performs the full memory barrier) must have
+		 *          previously seen desc_make_reusable:A.
+		 *
+		 * 2. Guarantee the tail ID is stored before storing the head
+		 *    ID. This pairs with desc_reserve:B.
+		 *
+		 * 3. Guarantee any data ring tail changes are stored before
+		 *    recycling the descriptor. Data ring tail changes can
+		 *    happen via desc_push_tail()->data_push_tail(). A full
+		 *    memory barrier is needed since another CPU may have
+		 *    pushed the data ring tails. This pairs with
+		 *    data_push_tail:B.
+		 *
+		 * 4. Guarantee a new tail ID is stored before recycling the
+		 *    descriptor. A full memory barrier is needed since
+		 *    another CPU may have pushed the tail ID. This pairs
+		 *    with desc_push_tail:C and this also pairs with
+		 *    prb_first_seq:C.
+		 *
+		 * 5. Guarantee the head ID is stored before trying to
+		 *    finalize the previous descriptor. This pairs with
+		 *    _prb_commit:B.
+		 */
+	} while (!atomic_long_try_cmpxchg(&desc_ring->head_id, &head_id,
+					  id)); /* LMM(desc_reserve:D) */
+
+	desc = to_desc(desc_ring, id);
+
+	/*
+	 * If the descriptor has been recycled, verify the old state val.
+	 * See "ABA Issues" about why this verification is performed.
+	 */
+	prev_state_val = atomic_long_read(&desc->state_var); /* LMM(desc_reserve:E) */
+	if (prev_state_val &&
+	    get_desc_state(id_prev_wrap, prev_state_val) != desc_reusable) {
+		WARN_ON_ONCE(1);
+		return false;
+	}
+
+	/*
+	 * Assign the descriptor a new ID and set its state to reserved.
+	 * See "ABA Issues" about why cmpxchg() instead of set() is used.
+	 *
+	 * Guarantee the new descriptor ID and state is stored before making
+	 * any other changes. A write memory barrier is sufficient for this.
+	 * This pairs with desc_read:D.
+	 */
+	if (!atomic_long_try_cmpxchg(&desc->state_var, &prev_state_val,
+			DESC_SV(id, desc_reserved))) { /* LMM(desc_reserve:F) */
+		WARN_ON_ONCE(1);
+		return false;
+	}
+
+	/* Now data in @desc can be modified: LMM(desc_reserve:G) */
+
+	*id_out = id;
+	return true;
+}
+
+/* Determine the end of a data block. */
+static unsigned long get_next_lpos(struct prb_data_ring *data_ring,
+				   unsigned long lpos, unsigned int size)
+{
+	unsigned long begin_lpos;
+	unsigned long next_lpos;
+
+	begin_lpos = lpos;
+	next_lpos = lpos + size;
+
+	/* First check if the data block does not wrap. */
+	if (DATA_WRAPS(data_ring, begin_lpos) == DATA_WRAPS(data_ring, next_lpos))
+		return next_lpos;
+
+	/* Wrapping data blocks store their data at the beginning. */
+	return (DATA_THIS_WRAP_START_LPOS(data_ring, next_lpos) + size);
+}
+
+/*
+ * Allocate a new data block, invalidating the oldest data block(s)
+ * if necessary. This function also associates the data block with
+ * a specified descriptor.
+ */
+static char *data_alloc(struct printk_ringbuffer *rb,
+			struct prb_data_ring *data_ring, unsigned int size,
+			struct prb_data_blk_lpos *blk_lpos, unsigned long id)
+{
+	struct prb_data_block *blk;
+	unsigned long begin_lpos;
+	unsigned long next_lpos;
+
+	if (size == 0) {
+		/* Specify a data-less block. */
+		blk_lpos->begin = NO_LPOS;
+		blk_lpos->next = NO_LPOS;
+		return NULL;
+	}
+
+	size = to_blk_size(size);
+
+	begin_lpos = atomic_long_read(&data_ring->head_lpos);
+
+	do {
+		next_lpos = get_next_lpos(data_ring, begin_lpos, size);
+
+		if (!data_push_tail(rb, data_ring, next_lpos - DATA_SIZE(data_ring))) {
+			/* Failed to allocate, specify a data-less block. */
+			blk_lpos->begin = FAILED_LPOS;
+			blk_lpos->next = FAILED_LPOS;
+			return NULL;
+		}
+
+		/*
+		 * 1. Guarantee any descriptor states that have transitioned
+		 *    to reusable are stored before modifying the newly
+		 *    allocated data area. A full memory barrier is needed
+		 *    since other CPUs may have made the descriptor states
+		 *    reusable. See data_push_tail:A about why the reusable
+		 *    states are visible. This pairs with desc_read:D.
+		 *
+		 * 2. Guarantee any updated tail lpos is stored before
+		 *    modifying the newly allocated data area. Another CPU may
+		 *    be in data_make_reusable() and is reading a block ID
+		 *    from this area. data_make_reusable() can handle reading
+		 *    a garbage block ID value, but then it must be able to
+		 *    load a new tail lpos. A full memory barrier is needed
+		 *    since other CPUs may have updated the tail lpos. This
+		 *    pairs with data_push_tail:B.
+		 */
+	} while (!atomic_long_try_cmpxchg(&data_ring->head_lpos, &begin_lpos,
+					  next_lpos)); /* LMM(data_alloc:A) */
+
+	blk = to_block(data_ring, begin_lpos);
+	blk->id = id; /* LMM(data_alloc:B) */
+
+	if (DATA_WRAPS(data_ring, begin_lpos) != DATA_WRAPS(data_ring, next_lpos)) {
+		/* Wrapping data blocks store their data at the beginning. */
+		blk = to_block(data_ring, 0);
+
+		/*
+		 * Store the ID on the wrapped block for consistency.
+		 * The printk_ringbuffer does not actually use it.
+		 */
+		blk->id = id;
+	}
+
+	blk_lpos->begin = begin_lpos;
+	blk_lpos->next = next_lpos;
+
+	return &blk->data[0];
+}
+
+/*
+ * Try to resize an existing data block associated with the descriptor
+ * specified by @id. If the resized data block should become wrapped, it
+ * copies the old data to the new data block. If @size yields a data block
+ * with the same or less size, the data block is left as is.
+ *
+ * Fail if this is not the last allocated data block or if there is not
+ * enough space or it is not possible make enough space.
+ *
+ * Return a pointer to the beginning of the entire data buffer or NULL on
+ * failure.
+ */
+static char *data_realloc(struct printk_ringbuffer *rb,
+			  struct prb_data_ring *data_ring, unsigned int size,
+			  struct prb_data_blk_lpos *blk_lpos, unsigned long id)
+{
+	struct prb_data_block *blk;
+	unsigned long head_lpos;
+	unsigned long next_lpos;
+	bool wrapped;
+
+	/* Reallocation only works if @blk_lpos is the newest data block. */
+	head_lpos = atomic_long_read(&data_ring->head_lpos);
+	if (head_lpos != blk_lpos->next)
+		return NULL;
+
+	/* Keep track if @blk_lpos was a wrapping data block. */
+	wrapped = (DATA_WRAPS(data_ring, blk_lpos->begin) != DATA_WRAPS(data_ring, blk_lpos->next));
+
+	size = to_blk_size(size);
+
+	next_lpos = get_next_lpos(data_ring, blk_lpos->begin, size);
+
+	/* If the data block does not increase, there is nothing to do. */
+	if (head_lpos - next_lpos < DATA_SIZE(data_ring)) {
+		if (wrapped)
+			blk = to_block(data_ring, 0);
+		else
+			blk = to_block(data_ring, blk_lpos->begin);
+		return &blk->data[0];
+	}
+
+	if (!data_push_tail(rb, data_ring, next_lpos - DATA_SIZE(data_ring)))
+		return NULL;
+
+	/* The memory barrier involvement is the same as data_alloc:A. */
+	if (!atomic_long_try_cmpxchg(&data_ring->head_lpos, &head_lpos,
+				     next_lpos)) { /* LMM(data_realloc:A) */
+		return NULL;
+	}
+
+	blk = to_block(data_ring, blk_lpos->begin);
+
+	if (DATA_WRAPS(data_ring, blk_lpos->begin) != DATA_WRAPS(data_ring, next_lpos)) {
+		struct prb_data_block *old_blk = blk;
+
+		/* Wrapping data blocks store their data at the beginning. */
+		blk = to_block(data_ring, 0);
+
+		/*
+		 * Store the ID on the wrapped block for consistency.
+		 * The printk_ringbuffer does not actually use it.
+		 */
+		blk->id = id;
+
+		if (!wrapped) {
+			/*
+			 * Since the allocated space is now in the newly
+			 * created wrapping data block, copy the content
+			 * from the old data block.
+			 */
+			memcpy(&blk->data[0], &old_blk->data[0],
+			       (blk_lpos->next - blk_lpos->begin) - sizeof(blk->id));
+		}
+	}
+
+	blk_lpos->next = next_lpos;
+
+	return &blk->data[0];
+}
+
+/* Return the number of bytes used by a data block. */
+static unsigned int space_used(struct prb_data_ring *data_ring,
+			       struct prb_data_blk_lpos *blk_lpos)
+{
+	/* Data-less blocks take no space. */
+	if (BLK_DATALESS(blk_lpos))
+		return 0;
+
+	if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next)) {
+		/* Data block does not wrap. */
+		return (DATA_INDEX(data_ring, blk_lpos->next) -
+			DATA_INDEX(data_ring, blk_lpos->begin));
+	}
+
+	/*
+	 * For wrapping data blocks, the trailing (wasted) space is
+	 * also counted.
+	 */
+	return (DATA_INDEX(data_ring, blk_lpos->next) +
+		DATA_SIZE(data_ring) - DATA_INDEX(data_ring, blk_lpos->begin));
+}
+
+/*
+ * Given @blk_lpos, return a pointer to the writer data from the data block
+ * and calculate the size of the data part. A NULL pointer is returned if
+ * @blk_lpos specifies values that could never be legal.
+ *
+ * This function (used by readers) performs strict validation on the lpos
+ * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
+ * triggered if an internal error is detected.
+ */
+static const char *get_data(struct prb_data_ring *data_ring,
+			    struct prb_data_blk_lpos *blk_lpos,
+			    unsigned int *data_size)
+{
+	struct prb_data_block *db;
+
+	/* Data-less data block description. */
+	if (BLK_DATALESS(blk_lpos)) {
+		if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
+			*data_size = 0;
+			return "";
+		}
+		return NULL;
+	}
+
+	/* Regular data block: @begin less than @next and in same wrap. */
+	if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&
+	    blk_lpos->begin < blk_lpos->next) {
+		db = to_block(data_ring, blk_lpos->begin);
+		*data_size = blk_lpos->next - blk_lpos->begin;
+
+	/* Wrapping data block: @begin is one wrap behind @next. */
+	} else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==
+		   DATA_WRAPS(data_ring, blk_lpos->next)) {
+		db = to_block(data_ring, 0);
+		*data_size = DATA_INDEX(data_ring, blk_lpos->next);
+
+	/* Illegal block description. */
+	} else {
+		WARN_ON_ONCE(1);
+		return NULL;
+	}
+
+	/* A valid data block will always be aligned to the ID size. */
+	if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||
+	    WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {
+		return NULL;
+	}
+
+	/* A valid data block will always have at least an ID. */
+	if (WARN_ON_ONCE(*data_size < sizeof(db->id)))
+		return NULL;
+
+	/* Subtract block ID space from size to reflect data size. */
+	*data_size -= sizeof(db->id);
+
+	return &db->data[0];
+}
+
+/*
+ * Attempt to transition the newest descriptor from committed back to reserved
+ * so that the record can be modified by a writer again. This is only possible
+ * if the descriptor is not yet finalized and the provided @caller_id matches.
+ */
+static struct prb_desc *desc_reopen_last(struct prb_desc_ring *desc_ring,
+					 u32 caller_id, unsigned long *id_out)
+{
+	unsigned long prev_state_val;
+	enum desc_state d_state;
+	struct prb_desc desc;
+	struct prb_desc *d;
+	unsigned long id;
+	u32 cid;
+
+	id = atomic_long_read(&desc_ring->head_id);
+
+	/*
+	 * To reduce unnecessarily reopening, first check if the descriptor
+	 * state and caller ID are correct.
+	 */
+	d_state = desc_read(desc_ring, id, &desc, NULL, &cid);
+	if (d_state != desc_committed || cid != caller_id)
+		return NULL;
+
+	d = to_desc(desc_ring, id);
+
+	prev_state_val = DESC_SV(id, desc_committed);
+
+	/*
+	 * Guarantee the reserved state is stored before reading any
+	 * record data. A full memory barrier is needed because @state_var
+	 * modification is followed by reading. This pairs with _prb_commit:B.
+	 *
+	 * Memory barrier involvement:
+	 *
+	 * If desc_reopen_last:A reads from _prb_commit:B, then
+	 * prb_reserve_in_last:A reads from _prb_commit:A.
+	 *
+	 * Relies on:
+	 *
+	 * WMB from _prb_commit:A to _prb_commit:B
+	 *    matching
+	 * MB If desc_reopen_last:A to prb_reserve_in_last:A
+	 */
+	if (!atomic_long_try_cmpxchg(&d->state_var, &prev_state_val,
+			DESC_SV(id, desc_reserved))) { /* LMM(desc_reopen_last:A) */
+		return NULL;
+	}
+
+	*id_out = id;
+	return d;
+}
+
+/**
+ * prb_reserve_in_last() - Re-reserve and extend the space in the ringbuffer
+ *                         used by the newest record.
+ *
+ * @e:         The entry structure to setup.
+ * @rb:        The ringbuffer to re-reserve and extend data in.
+ * @r:         The record structure to allocate buffers for.
+ * @caller_id: The caller ID of the caller (reserving writer).
+ * @max_size:  Fail if the extended size would be greater than this.
+ *
+ * This is the public function available to writers to re-reserve and extend
+ * data.
+ *
+ * The writer specifies the text size to extend (not the new total size) by
+ * setting the @text_buf_size field of @r. To ensure proper initialization
+ * of @r, prb_rec_init_wr() should be used.
+ *
+ * This function will fail if @caller_id does not match the caller ID of the
+ * newest record. In that case the caller must reserve new data using
+ * prb_reserve().
+ *
+ * Context: Any context. Disables local interrupts on success.
+ * Return: true if text data could be extended, otherwise false.
+ *
+ * On success:
+ *
+ *   - @r->text_buf points to the beginning of the entire text buffer.
+ *
+ *   - @r->text_buf_size is set to the new total size of the buffer.
+ *
+ *   - @r->info is not touched so that @r->info->text_len could be used
+ *     to append the text.
+ *
+ *   - prb_record_text_space() can be used on @e to query the new
+ *     actually used space.
+ *
+ * Important: All @r->info fields will already be set with the current values
+ *            for the record. I.e. @r->info->text_len will be less than
+ *            @text_buf_size. Writers can use @r->info->text_len to know
+ *            where concatenation begins and writers should update
+ *            @r->info->text_len after concatenating.
+ */
+bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer *rb,
+			 struct printk_record *r, u32 caller_id, unsigned int max_size)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	struct printk_info *info;
+	unsigned int data_size;
+	struct prb_desc *d;
+	unsigned long id;
+
+	local_irq_save(e->irqflags);
+
+	/* Transition the newest descriptor back to the reserved state. */
+	d = desc_reopen_last(desc_ring, caller_id, &id);
+	if (!d) {
+		local_irq_restore(e->irqflags);
+		goto fail_reopen;
+	}
+
+	/* Now the writer has exclusive access: LMM(prb_reserve_in_last:A) */
+
+	info = to_info(desc_ring, id);
+
+	/*
+	 * Set the @e fields here so that prb_commit() can be used if
+	 * anything fails from now on.
+	 */
+	e->rb = rb;
+	e->id = id;
+
+	/*
+	 * desc_reopen_last() checked the caller_id, but there was no
+	 * exclusive access at that point. The descriptor may have
+	 * changed since then.
+	 */
+	if (caller_id != info->caller_id)
+		goto fail;
+
+	if (BLK_DATALESS(&d->text_blk_lpos)) {
+		if (WARN_ON_ONCE(info->text_len != 0)) {
+			pr_warn_once("wrong text_len value (%hu, expecting 0)\n",
+				     info->text_len);
+			info->text_len = 0;
+		}
+
+		if (!data_check_size(&rb->text_data_ring, r->text_buf_size))
+			goto fail;
+
+		if (r->text_buf_size > max_size)
+			goto fail;
+
+		r->text_buf = data_alloc(rb, &rb->text_data_ring, r->text_buf_size,
+					 &d->text_blk_lpos, id);
+	} else {
+		if (!get_data(&rb->text_data_ring, &d->text_blk_lpos, &data_size))
+			goto fail;
+
+		/*
+		 * Increase the buffer size to include the original size. If
+		 * the meta data (@text_len) is not sane, use the full data
+		 * block size.
+		 */
+		if (WARN_ON_ONCE(info->text_len > data_size)) {
+			pr_warn_once("wrong text_len value (%hu, expecting <=%u)\n",
+				     info->text_len, data_size);
+			info->text_len = data_size;
+		}
+		r->text_buf_size += info->text_len;
+
+		if (!data_check_size(&rb->text_data_ring, r->text_buf_size))
+			goto fail;
+
+		if (r->text_buf_size > max_size)
+			goto fail;
+
+		r->text_buf = data_realloc(rb, &rb->text_data_ring, r->text_buf_size,
+					   &d->text_blk_lpos, id);
+	}
+	if (r->text_buf_size && !r->text_buf)
+		goto fail;
+
+	r->info = info;
+
+	e->text_space = space_used(&rb->text_data_ring, &d->text_blk_lpos);
+
+	return true;
+fail:
+	prb_commit(e);
+	/* prb_commit() re-enabled interrupts. */
+fail_reopen:
+	/* Make it clear to the caller that the re-reserve failed. */
+	memset(r, 0, sizeof(*r));
+	return false;
+}
+
+/*
+ * Attempt to finalize a specified descriptor. If this fails, the descriptor
+ * is either already final or it will finalize itself when the writer commits.
+ */
+static void desc_make_final(struct prb_desc_ring *desc_ring, unsigned long id)
+{
+	unsigned long prev_state_val = DESC_SV(id, desc_committed);
+	struct prb_desc *d = to_desc(desc_ring, id);
+
+	atomic_long_cmpxchg_relaxed(&d->state_var, prev_state_val,
+			DESC_SV(id, desc_finalized)); /* LMM(desc_make_final:A) */
+}
+
+/**
+ * prb_reserve() - Reserve space in the ringbuffer.
+ *
+ * @e:  The entry structure to setup.
+ * @rb: The ringbuffer to reserve data in.
+ * @r:  The record structure to allocate buffers for.
+ *
+ * This is the public function available to writers to reserve data.
+ *
+ * The writer specifies the text size to reserve by setting the
+ * @text_buf_size field of @r. To ensure proper initialization of @r,
+ * prb_rec_init_wr() should be used.
+ *
+ * Context: Any context. Disables local interrupts on success.
+ * Return: true if at least text data could be allocated, otherwise false.
+ *
+ * On success, the fields @info and @text_buf of @r will be set by this
+ * function and should be filled in by the writer before committing. Also
+ * on success, prb_record_text_space() can be used on @e to query the actual
+ * space used for the text data block.
+ *
+ * Important: @info->text_len needs to be set correctly by the writer in
+ *            order for data to be readable and/or extended. Its value
+ *            is initialized to 0.
+ */
+bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb,
+		 struct printk_record *r)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	struct printk_info *info;
+	struct prb_desc *d;
+	unsigned long id;
+	u64 seq;
+
+	if (!data_check_size(&rb->text_data_ring, r->text_buf_size))
+		goto fail;
+
+	/*
+	 * Descriptors in the reserved state act as blockers to all further
+	 * reservations once the desc_ring has fully wrapped. Disable
+	 * interrupts during the reserve/commit window in order to minimize
+	 * the likelihood of this happening.
+	 */
+	local_irq_save(e->irqflags);
+
+	if (!desc_reserve(rb, &id)) {
+		/* Descriptor reservation failures are tracked. */
+		atomic_long_inc(&rb->fail);
+		local_irq_restore(e->irqflags);
+		goto fail;
+	}
+
+	d = to_desc(desc_ring, id);
+	info = to_info(desc_ring, id);
+
+	/*
+	 * All @info fields (except @seq) are cleared and must be filled in
+	 * by the writer. Save @seq before clearing because it is used to
+	 * determine the new sequence number.
+	 */
+	seq = info->seq;
+	memset(info, 0, sizeof(*info));
+
+	/*
+	 * Set the @e fields here so that prb_commit() can be used if
+	 * text data allocation fails.
+	 */
+	e->rb = rb;
+	e->id = id;
+
+	/*
+	 * Initialize the sequence number if it has "never been set".
+	 * Otherwise just increment it by a full wrap.
+	 *
+	 * @seq is considered "never been set" if it has a value of 0,
+	 * _except_ for @infos[0], which was specially setup by the ringbuffer
+	 * initializer and therefore is always considered as set.
+	 *
+	 * See the "Bootstrap" comment block in printk_ringbuffer.h for
+	 * details about how the initializer bootstraps the descriptors.
+	 */
+	if (seq == 0 && DESC_INDEX(desc_ring, id) != 0)
+		info->seq = DESC_INDEX(desc_ring, id);
+	else
+		info->seq = seq + DESCS_COUNT(desc_ring);
+
+	/*
+	 * New data is about to be reserved. Once that happens, previous
+	 * descriptors are no longer able to be extended. Finalize the
+	 * previous descriptor now so that it can be made available to
+	 * readers. (For seq==0 there is no previous descriptor.)
+	 */
+	if (info->seq > 0)
+		desc_make_final(desc_ring, DESC_ID(id - 1));
+
+	r->text_buf = data_alloc(rb, &rb->text_data_ring, r->text_buf_size,
+				 &d->text_blk_lpos, id);
+	/* If text data allocation fails, a data-less record is committed. */
+	if (r->text_buf_size && !r->text_buf) {
+		prb_commit(e);
+		/* prb_commit() re-enabled interrupts. */
+		goto fail;
+	}
+
+	r->info = info;
+
+	/* Record full text space used by record. */
+	e->text_space = space_used(&rb->text_data_ring, &d->text_blk_lpos);
+
+	return true;
+fail:
+	/* Make it clear to the caller that the reserve failed. */
+	memset(r, 0, sizeof(*r));
+	return false;
+}
+
+/* Commit the data (possibly finalizing it) and restore interrupts. */
+static void _prb_commit(struct prb_reserved_entry *e, unsigned long state_val)
+{
+	struct prb_desc_ring *desc_ring = &e->rb->desc_ring;
+	struct prb_desc *d = to_desc(desc_ring, e->id);
+	unsigned long prev_state_val = DESC_SV(e->id, desc_reserved);
+
+	/* Now the writer has finished all writing: LMM(_prb_commit:A) */
+
+	/*
+	 * Set the descriptor as committed. See "ABA Issues" about why
+	 * cmpxchg() instead of set() is used.
+	 *
+	 * 1  Guarantee all record data is stored before the descriptor state
+	 *    is stored as committed. A write memory barrier is sufficient
+	 *    for this. This pairs with desc_read:B and desc_reopen_last:A.
+	 *
+	 * 2. Guarantee the descriptor state is stored as committed before
+	 *    re-checking the head ID in order to possibly finalize this
+	 *    descriptor. This pairs with desc_reserve:D.
+	 *
+	 *    Memory barrier involvement:
+	 *
+	 *    If prb_commit:A reads from desc_reserve:D, then
+	 *    desc_make_final:A reads from _prb_commit:B.
+	 *
+	 *    Relies on:
+	 *
+	 *    MB _prb_commit:B to prb_commit:A
+	 *       matching
+	 *    MB desc_reserve:D to desc_make_final:A
+	 */
+	if (!atomic_long_try_cmpxchg(&d->state_var, &prev_state_val,
+			DESC_SV(e->id, state_val))) { /* LMM(_prb_commit:B) */
+		WARN_ON_ONCE(1);
+	}
+
+	/* Restore interrupts, the reserve/commit window is finished. */
+	local_irq_restore(e->irqflags);
+}
+
+/**
+ * prb_commit() - Commit (previously reserved) data to the ringbuffer.
+ *
+ * @e: The entry containing the reserved data information.
+ *
+ * This is the public function available to writers to commit data.
+ *
+ * Note that the data is not yet available to readers until it is finalized.
+ * Finalizing happens automatically when space for the next record is
+ * reserved.
+ *
+ * See prb_final_commit() for a version of this function that finalizes
+ * immediately.
+ *
+ * Context: Any context. Enables local interrupts.
+ */
+void prb_commit(struct prb_reserved_entry *e)
+{
+	struct prb_desc_ring *desc_ring = &e->rb->desc_ring;
+	unsigned long head_id;
+
+	_prb_commit(e, desc_committed);
+
+	/*
+	 * If this descriptor is no longer the head (i.e. a new record has
+	 * been allocated), extending the data for this record is no longer
+	 * allowed and therefore it must be finalized.
+	 */
+	head_id = atomic_long_read(&desc_ring->head_id); /* LMM(prb_commit:A) */
+	if (head_id != e->id)
+		desc_make_final(desc_ring, e->id);
+}
+
+/**
+ * prb_final_commit() - Commit and finalize (previously reserved) data to
+ *                      the ringbuffer.
+ *
+ * @e: The entry containing the reserved data information.
+ *
+ * This is the public function available to writers to commit+finalize data.
+ *
+ * By finalizing, the data is made immediately available to readers.
+ *
+ * This function should only be used if there are no intentions of extending
+ * this data using prb_reserve_in_last().
+ *
+ * Context: Any context. Enables local interrupts.
+ */
+void prb_final_commit(struct prb_reserved_entry *e)
+{
+	_prb_commit(e, desc_finalized);
+}
+
+/*
+ * Count the number of lines in provided text. All text has at least 1 line
+ * (even if @text_size is 0). Each '\n' processed is counted as an additional
+ * line.
+ */
+static unsigned int count_lines(const char *text, unsigned int text_size)
+{
+	unsigned int next_size = text_size;
+	unsigned int line_count = 1;
+	const char *next = text;
+
+	while (next_size) {
+		next = memchr(next, '\n', next_size);
+		if (!next)
+			break;
+		line_count++;
+		next++;
+		next_size = text_size - (next - text);
+	}
+
+	return line_count;
+}
+
+/*
+ * Given @blk_lpos, copy an expected @len of data into the provided buffer.
+ * If @line_count is provided, count the number of lines in the data.
+ *
+ * This function (used by readers) performs strict validation on the data
+ * size to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
+ * triggered if an internal error is detected.
+ */
+static bool copy_data(struct prb_data_ring *data_ring,
+		      struct prb_data_blk_lpos *blk_lpos, u16 len, char *buf,
+		      unsigned int buf_size, unsigned int *line_count)
+{
+	unsigned int data_size;
+	const char *data;
+
+	/* Caller might not want any data. */
+	if ((!buf || !buf_size) && !line_count)
+		return true;
+
+	data = get_data(data_ring, blk_lpos, &data_size);
+	if (!data)
+		return false;
+
+	/*
+	 * Actual cannot be less than expected. It can be more than expected
+	 * because of the trailing alignment padding.
+	 *
+	 * Note that invalid @len values can occur because the caller loads
+	 * the value during an allowed data race.
+	 */
+	if (data_size < (unsigned int)len)
+		return false;
+
+	/* Caller interested in the line count? */
+	if (line_count)
+		*line_count = count_lines(data, len);
+
+	/* Caller interested in the data content? */
+	if (!buf || !buf_size)
+		return true;
+
+	data_size = min_t(u16, buf_size, len);
+
+	memcpy(&buf[0], data, data_size); /* LMM(copy_data:A) */
+	return true;
+}
+
+/*
+ * This is an extended version of desc_read(). It gets a copy of a specified
+ * descriptor. However, it also verifies that the record is finalized and has
+ * the sequence number @seq. On success, 0 is returned.
+ *
+ * Error return values:
+ * -EINVAL: A finalized record with sequence number @seq does not exist.
+ * -ENOENT: A finalized record with sequence number @seq exists, but its data
+ *          is not available. This is a valid record, so readers should
+ *          continue with the next record.
+ */
+static int desc_read_finalized_seq(struct prb_desc_ring *desc_ring,
+				   unsigned long id, u64 seq,
+				   struct prb_desc *desc_out)
+{
+	struct prb_data_blk_lpos *blk_lpos = &desc_out->text_blk_lpos;
+	enum desc_state d_state;
+	u64 s;
+
+	d_state = desc_read(desc_ring, id, desc_out, &s, NULL);
+
+	/*
+	 * An unexpected @id (desc_miss) or @seq mismatch means the record
+	 * does not exist. A descriptor in the reserved or committed state
+	 * means the record does not yet exist for the reader.
+	 */
+	if (d_state == desc_miss ||
+	    d_state == desc_reserved ||
+	    d_state == desc_committed ||
+	    s != seq) {
+		return -EINVAL;
+	}
+
+	/*
+	 * A descriptor in the reusable state may no longer have its data
+	 * available; report it as existing but with lost data. Or the record
+	 * may actually be a record with lost data.
+	 */
+	if (d_state == desc_reusable ||
+	    (blk_lpos->begin == FAILED_LPOS && blk_lpos->next == FAILED_LPOS)) {
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+/*
+ * Copy the ringbuffer data from the record with @seq to the provided
+ * @r buffer. On success, 0 is returned.
+ *
+ * See desc_read_finalized_seq() for error return values.
+ */
+static int prb_read(struct printk_ringbuffer *rb, u64 seq,
+		    struct printk_record *r, unsigned int *line_count)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	struct printk_info *info = to_info(desc_ring, seq);
+	struct prb_desc *rdesc = to_desc(desc_ring, seq);
+	atomic_long_t *state_var = &rdesc->state_var;
+	struct prb_desc desc;
+	unsigned long id;
+	int err;
+
+	/* Extract the ID, used to specify the descriptor to read. */
+	id = DESC_ID(atomic_long_read(state_var));
+
+	/* Get a local copy of the correct descriptor (if available). */
+	err = desc_read_finalized_seq(desc_ring, id, seq, &desc);
+
+	/*
+	 * If @r is NULL, the caller is only interested in the availability
+	 * of the record.
+	 */
+	if (err || !r)
+		return err;
+
+	/* If requested, copy meta data. */
+	if (r->info)
+		memcpy(r->info, info, sizeof(*(r->info)));
+
+	/* Copy text data. If it fails, this is a data-less record. */
+	if (!copy_data(&rb->text_data_ring, &desc.text_blk_lpos, info->text_len,
+		       r->text_buf, r->text_buf_size, line_count)) {
+		return -ENOENT;
+	}
+
+	/* Ensure the record is still finalized and has the same @seq. */
+	return desc_read_finalized_seq(desc_ring, id, seq, &desc);
+}
+
+/* Get the sequence number of the tail descriptor. */
+static u64 prb_first_seq(struct printk_ringbuffer *rb)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	enum desc_state d_state;
+	struct prb_desc desc;
+	unsigned long id;
+	u64 seq;
+
+	for (;;) {
+		id = atomic_long_read(&rb->desc_ring.tail_id); /* LMM(prb_first_seq:A) */
+
+		d_state = desc_read(desc_ring, id, &desc, &seq, NULL); /* LMM(prb_first_seq:B) */
+
+		/*
+		 * This loop will not be infinite because the tail is
+		 * _always_ in the finalized or reusable state.
+		 */
+		if (d_state == desc_finalized || d_state == desc_reusable)
+			break;
+
+		/*
+		 * Guarantee the last state load from desc_read() is before
+		 * reloading @tail_id in order to see a new tail in the case
+		 * that the descriptor has been recycled. This pairs with
+		 * desc_reserve:D.
+		 *
+		 * Memory barrier involvement:
+		 *
+		 * If prb_first_seq:B reads from desc_reserve:F, then
+		 * prb_first_seq:A reads from desc_push_tail:B.
+		 *
+		 * Relies on:
+		 *
+		 * MB from desc_push_tail:B to desc_reserve:F
+		 *    matching
+		 * RMB prb_first_seq:B to prb_first_seq:A
+		 */
+		smp_rmb(); /* LMM(prb_first_seq:C) */
+	}
+
+	return seq;
+}
+
+/*
+ * Non-blocking read of a record. Updates @seq to the last finalized record
+ * (which may have no data available).
+ *
+ * See the description of prb_read_valid() and prb_read_valid_info()
+ * for details.
+ */
+static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
+			    struct printk_record *r, unsigned int *line_count)
+{
+	u64 tail_seq;
+	int err;
+
+	while ((err = prb_read(rb, *seq, r, line_count))) {
+		tail_seq = prb_first_seq(rb);
+
+		if (*seq < tail_seq) {
+			/*
+			 * Behind the tail. Catch up and try again. This
+			 * can happen for -ENOENT and -EINVAL cases.
+			 */
+			*seq = tail_seq;
+
+		} else if (err == -ENOENT) {
+			/* Record exists, but no data available. Skip. */
+			(*seq)++;
+
+		} else {
+			/* Non-existent/non-finalized record. Must stop. */
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/**
+ * prb_read_valid() - Non-blocking read of a requested record or (if gone)
+ *                    the next available record.
+ *
+ * @rb:  The ringbuffer to read from.
+ * @seq: The sequence number of the record to read.
+ * @r:   A record data buffer to store the read record to.
+ *
+ * This is the public function available to readers to read a record.
+ *
+ * The reader provides the @info and @text_buf buffers of @r to be
+ * filled in. Any of the buffer pointers can be set to NULL if the reader
+ * is not interested in that data. To ensure proper initialization of @r,
+ * prb_rec_init_rd() should be used.
+ *
+ * Context: Any context.
+ * Return: true if a record was read, otherwise false.
+ *
+ * On success, the reader must check r->info.seq to see which record was
+ * actually read. This allows the reader to detect dropped records.
+ *
+ * Failure means @seq refers to a not yet written record.
+ */
+bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
+		    struct printk_record *r)
+{
+	return _prb_read_valid(rb, &seq, r, NULL);
+}
+
+/**
+ * prb_read_valid_info() - Non-blocking read of meta data for a requested
+ *                         record or (if gone) the next available record.
+ *
+ * @rb:         The ringbuffer to read from.
+ * @seq:        The sequence number of the record to read.
+ * @info:       A buffer to store the read record meta data to.
+ * @line_count: A buffer to store the number of lines in the record text.
+ *
+ * This is the public function available to readers to read only the
+ * meta data of a record.
+ *
+ * The reader provides the @info, @line_count buffers to be filled in.
+ * Either of the buffer pointers can be set to NULL if the reader is not
+ * interested in that data.
+ *
+ * Context: Any context.
+ * Return: true if a record's meta data was read, otherwise false.
+ *
+ * On success, the reader must check info->seq to see which record meta data
+ * was actually read. This allows the reader to detect dropped records.
+ *
+ * Failure means @seq refers to a not yet written record.
+ */
+bool prb_read_valid_info(struct printk_ringbuffer *rb, u64 seq,
+			 struct printk_info *info, unsigned int *line_count)
+{
+	struct printk_record r;
+
+	prb_rec_init_rd(&r, info, NULL, 0);
+
+	return _prb_read_valid(rb, &seq, &r, line_count);
+}
+
+/**
+ * prb_first_valid_seq() - Get the sequence number of the oldest available
+ *                         record.
+ *
+ * @rb: The ringbuffer to get the sequence number from.
+ *
+ * This is the public function available to readers to see what the
+ * first/oldest valid sequence number is.
+ *
+ * This provides readers a starting point to begin iterating the ringbuffer.
+ *
+ * Context: Any context.
+ * Return: The sequence number of the first/oldest record or, if the
+ *         ringbuffer is empty, 0 is returned.
+ */
+u64 prb_first_valid_seq(struct printk_ringbuffer *rb)
+{
+	u64 seq = 0;
+
+	if (!_prb_read_valid(rb, &seq, NULL, NULL))
+		return 0;
+
+	return seq;
+}
+
+/**
+ * prb_next_seq() - Get the sequence number after the last available record.
+ *
+ * @rb:  The ringbuffer to get the sequence number from.
+ *
+ * This is the public function available to readers to see what the next
+ * newest sequence number available to readers will be.
+ *
+ * This provides readers a sequence number to jump to if all currently
+ * available records should be skipped.
+ *
+ * Context: Any context.
+ * Return: The sequence number of the next newest (not yet available) record
+ *         for readers.
+ */
+u64 prb_next_seq(struct printk_ringbuffer *rb)
+{
+	u64 seq = 0;
+
+	/* Search forward from the oldest descriptor. */
+	while (_prb_read_valid(rb, &seq, NULL, NULL))
+		seq++;
+
+	return seq;
+}
+
+/**
+ * prb_init() - Initialize a ringbuffer to use provided external buffers.
+ *
+ * @rb:       The ringbuffer to initialize.
+ * @text_buf: The data buffer for text data.
+ * @textbits: The size of @text_buf as a power-of-2 value.
+ * @descs:    The descriptor buffer for ringbuffer records.
+ * @descbits: The count of @descs items as a power-of-2 value.
+ * @infos:    The printk_info buffer for ringbuffer records.
+ *
+ * This is the public function available to writers to setup a ringbuffer
+ * during runtime using provided buffers.
+ *
+ * This must match the initialization of DEFINE_PRINTKRB().
+ *
+ * Context: Any context.
+ */
+void prb_init(struct printk_ringbuffer *rb,
+	      char *text_buf, unsigned int textbits,
+	      struct prb_desc *descs, unsigned int descbits,
+	      struct printk_info *infos)
+{
+	memset(descs, 0, _DESCS_COUNT(descbits) * sizeof(descs[0]));
+	memset(infos, 0, _DESCS_COUNT(descbits) * sizeof(infos[0]));
+
+	rb->desc_ring.count_bits = descbits;
+	rb->desc_ring.descs = descs;
+	rb->desc_ring.infos = infos;
+	atomic_long_set(&rb->desc_ring.head_id, DESC0_ID(descbits));
+	atomic_long_set(&rb->desc_ring.tail_id, DESC0_ID(descbits));
+
+	rb->text_data_ring.size_bits = textbits;
+	rb->text_data_ring.data = text_buf;
+	atomic_long_set(&rb->text_data_ring.head_lpos, BLK0_LPOS(textbits));
+	atomic_long_set(&rb->text_data_ring.tail_lpos, BLK0_LPOS(textbits));
+
+	atomic_long_set(&rb->fail, 0);
+
+	atomic_long_set(&(descs[_DESCS_COUNT(descbits) - 1].state_var), DESC0_SV(descbits));
+	descs[_DESCS_COUNT(descbits) - 1].text_blk_lpos.begin = FAILED_LPOS;
+	descs[_DESCS_COUNT(descbits) - 1].text_blk_lpos.next = FAILED_LPOS;
+
+	infos[0].seq = -(u64)_DESCS_COUNT(descbits);
+	infos[_DESCS_COUNT(descbits) - 1].seq = 0;
+}
+
+/**
+ * prb_record_text_space() - Query the full actual used ringbuffer space for
+ *                           the text data of a reserved entry.
+ *
+ * @e: The successfully reserved entry to query.
+ *
+ * This is the public function available to writers to see how much actual
+ * space is used in the ringbuffer to store the text data of the specified
+ * entry.
+ *
+ * This function is only valid if @e has been successfully reserved using
+ * prb_reserve().
+ *
+ * Context: Any context.
+ * Return: The size in bytes used by the text data of the associated record.
+ */
+unsigned int prb_record_text_space(struct prb_reserved_entry *e)
+{
+	return e->text_space;
+}
diff --git a/kernel/printk/printk_ringbuffer.h b/kernel/printk/printk_ringbuffer.h
new file mode 100644
index 0000000..5dc9d02
--- /dev/null
+++ b/kernel/printk/printk_ringbuffer.h
@@ -0,0 +1,382 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _KERNEL_PRINTK_RINGBUFFER_H
+#define _KERNEL_PRINTK_RINGBUFFER_H
+
+#include <linux/atomic.h>
+#include <linux/dev_printk.h>
+
+/*
+ * Meta information about each stored message.
+ *
+ * All fields are set by the printk code except for @seq, which is
+ * set by the ringbuffer code.
+ */
+struct printk_info {
+	u64	seq;		/* sequence number */
+	u64	ts_nsec;	/* timestamp in nanoseconds */
+	u16	text_len;	/* length of text message */
+	u8	facility;	/* syslog facility */
+	u8	flags:5;	/* internal record flags */
+	u8	level:3;	/* syslog level */
+	u32	caller_id;	/* thread id or processor id */
+
+	struct dev_printk_info	dev_info;
+};
+
+/*
+ * A structure providing the buffers, used by writers and readers.
+ *
+ * Writers:
+ * Using prb_rec_init_wr(), a writer sets @text_buf_size before calling
+ * prb_reserve(). On success, prb_reserve() sets @info and @text_buf to
+ * buffers reserved for that writer.
+ *
+ * Readers:
+ * Using prb_rec_init_rd(), a reader sets all fields before calling
+ * prb_read_valid(). Note that the reader provides the @info and @text_buf,
+ * buffers. On success, the struct pointed to by @info will be filled and
+ * the char array pointed to by @text_buf will be filled with text data.
+ */
+struct printk_record {
+	struct printk_info	*info;
+	char			*text_buf;
+	unsigned int		text_buf_size;
+};
+
+/* Specifies the logical position and span of a data block. */
+struct prb_data_blk_lpos {
+	unsigned long	begin;
+	unsigned long	next;
+};
+
+/*
+ * A descriptor: the complete meta-data for a record.
+ *
+ * @state_var: A bitwise combination of descriptor ID and descriptor state.
+ */
+struct prb_desc {
+	atomic_long_t			state_var;
+	struct prb_data_blk_lpos	text_blk_lpos;
+};
+
+/* A ringbuffer of "ID + data" elements. */
+struct prb_data_ring {
+	unsigned int	size_bits;
+	char		*data;
+	atomic_long_t	head_lpos;
+	atomic_long_t	tail_lpos;
+};
+
+/* A ringbuffer of "struct prb_desc" elements. */
+struct prb_desc_ring {
+	unsigned int		count_bits;
+	struct prb_desc		*descs;
+	struct printk_info	*infos;
+	atomic_long_t		head_id;
+	atomic_long_t		tail_id;
+};
+
+/*
+ * The high level structure representing the printk ringbuffer.
+ *
+ * @fail: Count of failed prb_reserve() calls where not even a data-less
+ *        record was created.
+ */
+struct printk_ringbuffer {
+	struct prb_desc_ring	desc_ring;
+	struct prb_data_ring	text_data_ring;
+	atomic_long_t		fail;
+};
+
+/*
+ * Used by writers as a reserve/commit handle.
+ *
+ * @rb:         Ringbuffer where the entry is reserved.
+ * @irqflags:   Saved irq flags to restore on entry commit.
+ * @id:         ID of the reserved descriptor.
+ * @text_space: Total occupied buffer space in the text data ring, including
+ *              ID, alignment padding, and wrapping data blocks.
+ *
+ * This structure is an opaque handle for writers. Its contents are only
+ * to be used by the ringbuffer implementation.
+ */
+struct prb_reserved_entry {
+	struct printk_ringbuffer	*rb;
+	unsigned long			irqflags;
+	unsigned long			id;
+	unsigned int			text_space;
+};
+
+/* The possible responses of a descriptor state-query. */
+enum desc_state {
+	desc_miss	=  -1,	/* ID mismatch (pseudo state) */
+	desc_reserved	= 0x0,	/* reserved, in use by writer */
+	desc_committed	= 0x1,	/* committed by writer, could get reopened */
+	desc_finalized	= 0x2,	/* committed, no further modification allowed */
+	desc_reusable	= 0x3,	/* free, not yet used by any writer */
+};
+
+#define _DATA_SIZE(sz_bits)	(1UL << (sz_bits))
+#define _DESCS_COUNT(ct_bits)	(1U << (ct_bits))
+#define DESC_SV_BITS		(sizeof(unsigned long) * 8)
+#define DESC_FLAGS_SHIFT	(DESC_SV_BITS - 2)
+#define DESC_FLAGS_MASK		(3UL << DESC_FLAGS_SHIFT)
+#define DESC_STATE(sv)		(3UL & (sv >> DESC_FLAGS_SHIFT))
+#define DESC_SV(id, state)	(((unsigned long)state << DESC_FLAGS_SHIFT) | id)
+#define DESC_ID_MASK		(~DESC_FLAGS_MASK)
+#define DESC_ID(sv)		((sv) & DESC_ID_MASK)
+#define FAILED_LPOS		0x1
+#define NO_LPOS			0x3
+
+#define FAILED_BLK_LPOS	\
+{				\
+	.begin	= FAILED_LPOS,	\
+	.next	= FAILED_LPOS,	\
+}
+
+/*
+ * Descriptor Bootstrap
+ *
+ * The descriptor array is minimally initialized to allow immediate usage
+ * by readers and writers. The requirements that the descriptor array
+ * initialization must satisfy:
+ *
+ *   Req1
+ *     The tail must point to an existing (committed or reusable) descriptor.
+ *     This is required by the implementation of prb_first_seq().
+ *
+ *   Req2
+ *     Readers must see that the ringbuffer is initially empty.
+ *
+ *   Req3
+ *     The first record reserved by a writer is assigned sequence number 0.
+ *
+ * To satisfy Req1, the tail initially points to a descriptor that is
+ * minimally initialized (having no data block, i.e. data-less with the
+ * data block's lpos @begin and @next values set to FAILED_LPOS).
+ *
+ * To satisfy Req2, the initial tail descriptor is initialized to the
+ * reusable state. Readers recognize reusable descriptors as existing
+ * records, but skip over them.
+ *
+ * To satisfy Req3, the last descriptor in the array is used as the initial
+ * head (and tail) descriptor. This allows the first record reserved by a
+ * writer (head + 1) to be the first descriptor in the array. (Only the first
+ * descriptor in the array could have a valid sequence number of 0.)
+ *
+ * The first time a descriptor is reserved, it is assigned a sequence number
+ * with the value of the array index. A "first time reserved" descriptor can
+ * be recognized because it has a sequence number of 0 but does not have an
+ * index of 0. (Only the first descriptor in the array could have a valid
+ * sequence number of 0.) After the first reservation, all future reservations
+ * (recycling) simply involve incrementing the sequence number by the array
+ * count.
+ *
+ *   Hack #1
+ *     Only the first descriptor in the array is allowed to have the sequence
+ *     number 0. In this case it is not possible to recognize if it is being
+ *     reserved the first time (set to index value) or has been reserved
+ *     previously (increment by the array count). This is handled by _always_
+ *     incrementing the sequence number by the array count when reserving the
+ *     first descriptor in the array. In order to satisfy Req3, the sequence
+ *     number of the first descriptor in the array is initialized to minus
+ *     the array count. Then, upon the first reservation, it is incremented
+ *     to 0, thus satisfying Req3.
+ *
+ *   Hack #2
+ *     prb_first_seq() can be called at any time by readers to retrieve the
+ *     sequence number of the tail descriptor. However, due to Req2 and Req3,
+ *     initially there are no records to report the sequence number of
+ *     (sequence numbers are u64 and there is nothing less than 0). To handle
+ *     this, the sequence number of the initial tail descriptor is initialized
+ *     to 0. Technically this is incorrect, because there is no record with
+ *     sequence number 0 (yet) and the tail descriptor is not the first
+ *     descriptor in the array. But it allows prb_read_valid() to correctly
+ *     report the existence of a record for _any_ given sequence number at all
+ *     times. Bootstrapping is complete when the tail is pushed the first
+ *     time, thus finally pointing to the first descriptor reserved by a
+ *     writer, which has the assigned sequence number 0.
+ */
+
+/*
+ * Initiating Logical Value Overflows
+ *
+ * Both logical position (lpos) and ID values can be mapped to array indexes
+ * but may experience overflows during the lifetime of the system. To ensure
+ * that printk_ringbuffer can handle the overflows for these types, initial
+ * values are chosen that map to the correct initial array indexes, but will
+ * result in overflows soon.
+ *
+ *   BLK0_LPOS
+ *     The initial @head_lpos and @tail_lpos for data rings. It is at index
+ *     0 and the lpos value is such that it will overflow on the first wrap.
+ *
+ *   DESC0_ID
+ *     The initial @head_id and @tail_id for the desc ring. It is at the last
+ *     index of the descriptor array (see Req3 above) and the ID value is such
+ *     that it will overflow on the second wrap.
+ */
+#define BLK0_LPOS(sz_bits)	(-(_DATA_SIZE(sz_bits)))
+#define DESC0_ID(ct_bits)	DESC_ID(-(_DESCS_COUNT(ct_bits) + 1))
+#define DESC0_SV(ct_bits)	DESC_SV(DESC0_ID(ct_bits), desc_reusable)
+
+/*
+ * Define a ringbuffer with an external text data buffer. The same as
+ * DEFINE_PRINTKRB() but requires specifying an external buffer for the
+ * text data.
+ *
+ * Note: The specified external buffer must be of the size:
+ *       2 ^ (descbits + avgtextbits)
+ */
+#define _DEFINE_PRINTKRB(name, descbits, avgtextbits, text_buf)			\
+static struct prb_desc _##name##_descs[_DESCS_COUNT(descbits)] = {				\
+	/* the initial head and tail */								\
+	[_DESCS_COUNT(descbits) - 1] = {							\
+		/* reusable */									\
+		.state_var	= ATOMIC_INIT(DESC0_SV(descbits)),				\
+		/* no associated data block */							\
+		.text_blk_lpos	= FAILED_BLK_LPOS,						\
+	},											\
+};												\
+static struct printk_info _##name##_infos[_DESCS_COUNT(descbits)] = {				\
+	/* this will be the first record reserved by a writer */				\
+	[0] = {											\
+		/* will be incremented to 0 on the first reservation */				\
+		.seq = -(u64)_DESCS_COUNT(descbits),						\
+	},											\
+	/* the initial head and tail */								\
+	[_DESCS_COUNT(descbits) - 1] = {							\
+		/* reports the first seq value during the bootstrap phase */			\
+		.seq = 0,									\
+	},											\
+};												\
+static struct printk_ringbuffer name = {							\
+	.desc_ring = {										\
+		.count_bits	= descbits,							\
+		.descs		= &_##name##_descs[0],						\
+		.infos		= &_##name##_infos[0],						\
+		.head_id	= ATOMIC_INIT(DESC0_ID(descbits)),				\
+		.tail_id	= ATOMIC_INIT(DESC0_ID(descbits)),				\
+	},											\
+	.text_data_ring = {									\
+		.size_bits	= (avgtextbits) + (descbits),					\
+		.data		= text_buf,							\
+		.head_lpos	= ATOMIC_LONG_INIT(BLK0_LPOS((avgtextbits) + (descbits))),	\
+		.tail_lpos	= ATOMIC_LONG_INIT(BLK0_LPOS((avgtextbits) + (descbits))),	\
+	},											\
+	.fail			= ATOMIC_LONG_INIT(0),						\
+}
+
+/**
+ * DEFINE_PRINTKRB() - Define a ringbuffer.
+ *
+ * @name:        The name of the ringbuffer variable.
+ * @descbits:    The number of descriptors as a power-of-2 value.
+ * @avgtextbits: The average text data size per record as a power-of-2 value.
+ *
+ * This is a macro for defining a ringbuffer and all internal structures
+ * such that it is ready for immediate use. See _DEFINE_PRINTKRB() for a
+ * variant where the text data buffer can be specified externally.
+ */
+#define DEFINE_PRINTKRB(name, descbits, avgtextbits)				\
+static char _##name##_text[1U << ((avgtextbits) + (descbits))]			\
+			__aligned(__alignof__(unsigned long));			\
+_DEFINE_PRINTKRB(name, descbits, avgtextbits, &_##name##_text[0])
+
+/* Writer Interface */
+
+/**
+ * prb_rec_init_wd() - Initialize a buffer for writing records.
+ *
+ * @r:             The record to initialize.
+ * @text_buf_size: The needed text buffer size.
+ */
+static inline void prb_rec_init_wr(struct printk_record *r,
+				   unsigned int text_buf_size)
+{
+	r->info = NULL;
+	r->text_buf = NULL;
+	r->text_buf_size = text_buf_size;
+}
+
+bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb,
+		 struct printk_record *r);
+bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer *rb,
+			 struct printk_record *r, u32 caller_id, unsigned int max_size);
+void prb_commit(struct prb_reserved_entry *e);
+void prb_final_commit(struct prb_reserved_entry *e);
+
+void prb_init(struct printk_ringbuffer *rb,
+	      char *text_buf, unsigned int text_buf_size,
+	      struct prb_desc *descs, unsigned int descs_count_bits,
+	      struct printk_info *infos);
+unsigned int prb_record_text_space(struct prb_reserved_entry *e);
+
+/* Reader Interface */
+
+/**
+ * prb_rec_init_rd() - Initialize a buffer for reading records.
+ *
+ * @r:             The record to initialize.
+ * @info:          A buffer to store record meta-data.
+ * @text_buf:      A buffer to store text data.
+ * @text_buf_size: The size of @text_buf.
+ *
+ * Initialize all the fields that a reader is interested in. All arguments
+ * (except @r) are optional. Only record data for arguments that are
+ * non-NULL or non-zero will be read.
+ */
+static inline void prb_rec_init_rd(struct printk_record *r,
+				   struct printk_info *info,
+				   char *text_buf, unsigned int text_buf_size)
+{
+	r->info = info;
+	r->text_buf = text_buf;
+	r->text_buf_size = text_buf_size;
+}
+
+/**
+ * prb_for_each_record() - Iterate over the records of a ringbuffer.
+ *
+ * @from: The sequence number to begin with.
+ * @rb:   The ringbuffer to iterate over.
+ * @s:    A u64 to store the sequence number on each iteration.
+ * @r:    A printk_record to store the record on each iteration.
+ *
+ * This is a macro for conveniently iterating over a ringbuffer.
+ * Note that @s may not be the sequence number of the record on each
+ * iteration. For the sequence number, @r->info->seq should be checked.
+ *
+ * Context: Any context.
+ */
+#define prb_for_each_record(from, rb, s, r) \
+for ((s) = from; prb_read_valid(rb, s, r); (s) = (r)->info->seq + 1)
+
+/**
+ * prb_for_each_info() - Iterate over the meta data of a ringbuffer.
+ *
+ * @from: The sequence number to begin with.
+ * @rb:   The ringbuffer to iterate over.
+ * @s:    A u64 to store the sequence number on each iteration.
+ * @i:    A printk_info to store the record meta data on each iteration.
+ * @lc:   An unsigned int to store the text line count of each record.
+ *
+ * This is a macro for conveniently iterating over a ringbuffer.
+ * Note that @s may not be the sequence number of the record on each
+ * iteration. For the sequence number, @r->info->seq should be checked.
+ *
+ * Context: Any context.
+ */
+#define prb_for_each_info(from, rb, s, i, lc) \
+for ((s) = from; prb_read_valid_info(rb, s, i, lc); (s) = (i)->seq + 1)
+
+bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
+		    struct printk_record *r);
+bool prb_read_valid_info(struct printk_ringbuffer *rb, u64 seq,
+			 struct printk_info *info, unsigned int *line_count);
+
+u64 prb_first_valid_seq(struct printk_ringbuffer *rb);
+u64 prb_next_seq(struct printk_ringbuffer *rb);
+
+#endif /* _KERNEL_PRINTK_RINGBUFFER_H */
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 6cfc5a0..2e9e3ed 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -6,10 +6,12 @@
 #include <linux/preempt.h>
 #include <linux/spinlock.h>
 #include <linux/debug_locks.h>
+#include <linux/kdb.h>
 #include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/irq_work.h>
 #include <linux/printk.h>
+#include <linux/kprobes.h>
 
 #include "internal.h"
 
@@ -20,7 +22,7 @@
  * is later flushed into the main ring buffer via IRQ work.
  *
  * The alternative implementation is chosen transparently
- * by examinig current printk() context mask stored in @printk_context
+ * by examining current printk() context mask stored in @printk_context
  * per-CPU variable.
  *
  * The implementation allows to flush the strings also from another CPU.
@@ -301,14 +303,14 @@
 	return printk_safe_log_store(s, fmt, args);
 }
 
-void notrace printk_nmi_enter(void)
+void noinstr printk_nmi_enter(void)
 {
-	this_cpu_or(printk_context, PRINTK_NMI_CONTEXT_MASK);
+	this_cpu_add(printk_context, PRINTK_NMI_CONTEXT_OFFSET);
 }
 
-void notrace printk_nmi_exit(void)
+void noinstr printk_nmi_exit(void)
 {
-	this_cpu_and(printk_context, ~PRINTK_NMI_CONTEXT_MASK);
+	this_cpu_sub(printk_context, PRINTK_NMI_CONTEXT_OFFSET);
 }
 
 /*
@@ -367,6 +369,12 @@
 
 __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
 {
+#ifdef CONFIG_KGDB_KDB
+	/* Allow to pass printk() to kdb but avoid a recursion. */
+	if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0))
+		return vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args);
+#endif
+
 	/*
 	 * Try to use the main logbuf even in NMI. But avoid calling console
 	 * drivers that might have their own locks.
@@ -375,7 +383,7 @@
 	    raw_spin_trylock(&logbuf_lock)) {
 		int len;
 
-		len = vprintk_store(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
+		len = vprintk_store(0, LOGLEVEL_DEFAULT, NULL, fmt, args);
 		raw_spin_unlock(&logbuf_lock);
 		defer_console_output();
 		return len;
diff --git a/kernel/profile.c b/kernel/profile.c
index af7c94b..b47fe52 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -41,7 +41,8 @@
 #define NR_PROFILE_GRP		(NR_PROFILE_HIT/PROFILE_GRPSZ)
 
 static atomic_t *prof_buffer;
-static unsigned long prof_len, prof_shift;
+static unsigned long prof_len;
+static unsigned short int prof_shift;
 
 int prof_on __read_mostly;
 EXPORT_SYMBOL_GPL(prof_on);
@@ -67,8 +68,8 @@
 		if (str[strlen(sleepstr)] == ',')
 			str += strlen(sleepstr) + 1;
 		if (get_option(&str, &par))
-			prof_shift = par;
-		pr_info("kernel sleep profiling enabled (shift: %ld)\n",
+			prof_shift = clamp(par, 0, BITS_PER_LONG - 1);
+		pr_info("kernel sleep profiling enabled (shift: %u)\n",
 			prof_shift);
 #else
 		pr_warn("kernel sleep profiling requires CONFIG_SCHEDSTATS\n");
@@ -78,21 +79,21 @@
 		if (str[strlen(schedstr)] == ',')
 			str += strlen(schedstr) + 1;
 		if (get_option(&str, &par))
-			prof_shift = par;
-		pr_info("kernel schedule profiling enabled (shift: %ld)\n",
+			prof_shift = clamp(par, 0, BITS_PER_LONG - 1);
+		pr_info("kernel schedule profiling enabled (shift: %u)\n",
 			prof_shift);
 	} else if (!strncmp(str, kvmstr, strlen(kvmstr))) {
 		prof_on = KVM_PROFILING;
 		if (str[strlen(kvmstr)] == ',')
 			str += strlen(kvmstr) + 1;
 		if (get_option(&str, &par))
-			prof_shift = par;
-		pr_info("kernel KVM profiling enabled (shift: %ld)\n",
+			prof_shift = clamp(par, 0, BITS_PER_LONG - 1);
+		pr_info("kernel KVM profiling enabled (shift: %u)\n",
 			prof_shift);
 	} else if (get_option(&str, &par)) {
-		prof_shift = par;
+		prof_shift = clamp(par, 0, BITS_PER_LONG - 1);
 		prof_on = CPU_PROFILING;
-		pr_info("kernel profiling enabled (shift: %ld)\n",
+		pr_info("kernel profiling enabled (shift: %u)\n",
 			prof_shift);
 	}
 	return 1;
@@ -336,7 +337,7 @@
 	struct page *page;
 	int i;
 
-	if (prof_cpu_mask != NULL)
+	if (cpumask_available(prof_cpu_mask))
 		cpumask_clear_cpu(cpu, prof_cpu_mask);
 
 	for (i = 0; i < 2; i++) {
@@ -373,7 +374,7 @@
 
 static int profile_online_cpu(unsigned int cpu)
 {
-	if (prof_cpu_mask != NULL)
+	if (cpumask_available(prof_cpu_mask))
 		cpumask_set_cpu(cpu, prof_cpu_mask);
 
 	return 0;
@@ -403,7 +404,7 @@
 {
 	struct pt_regs *regs = get_irq_regs();
 
-	if (!user_mode(regs) && prof_cpu_mask != NULL &&
+	if (!user_mode(regs) && cpumask_available(prof_cpu_mask) &&
 	    cpumask_test_cpu(smp_processor_id(), prof_cpu_mask))
 		profile_hit(type, (void *)profile_pc(regs));
 }
@@ -442,18 +443,18 @@
 	return err;
 }
 
-static const struct file_operations prof_cpu_mask_proc_fops = {
-	.open		= prof_cpu_mask_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-	.write		= prof_cpu_mask_proc_write,
+static const struct proc_ops prof_cpu_mask_proc_ops = {
+	.proc_open	= prof_cpu_mask_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
+	.proc_write	= prof_cpu_mask_proc_write,
 };
 
 void create_prof_cpu_mask(void)
 {
 	/* create /proc/irq/prof_cpu_mask */
-	proc_create("irq/prof_cpu_mask", 0600, NULL, &prof_cpu_mask_proc_fops);
+	proc_create("irq/prof_cpu_mask", 0600, NULL, &prof_cpu_mask_proc_ops);
 }
 
 /*
@@ -468,7 +469,7 @@
 	unsigned long p = *ppos;
 	ssize_t read;
 	char *pnt;
-	unsigned int sample_step = 1 << prof_shift;
+	unsigned long sample_step = 1UL << prof_shift;
 
 	profile_flip_buffers();
 	if (p >= (prof_len+1)*sizeof(unsigned int))
@@ -517,10 +518,10 @@
 	return count;
 }
 
-static const struct file_operations proc_profile_operations = {
-	.read		= read_profile,
-	.write		= write_profile,
-	.llseek		= default_llseek,
+static const struct proc_ops profile_proc_ops = {
+	.proc_read	= read_profile,
+	.proc_write	= write_profile,
+	.proc_lseek	= default_llseek,
 };
 
 int __ref create_proc_profile(void)
@@ -548,7 +549,7 @@
 	err = 0;
 #endif
 	entry = proc_create("profile", S_IWUSR | S_IRUGO,
-			    NULL, &proc_profile_operations);
+			    NULL, &profile_proc_ops);
 	if (!entry)
 		goto err_state_onl;
 	proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t));
diff --git a/kernel/range.c b/kernel/range.c
index d84de67..56435f9 100644
--- a/kernel/range.c
+++ b/kernel/range.c
@@ -2,8 +2,9 @@
 /*
  * Range add and subtract
  */
-#include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/minmax.h>
+#include <linux/printk.h>
 #include <linux/sort.h>
 #include <linux/string.h>
 #include <linux/range.h>
diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
index 7644eda..b71e21f 100644
--- a/kernel/rcu/Kconfig
+++ b/kernel/rcu/Kconfig
@@ -7,7 +7,7 @@
 
 config TREE_RCU
 	bool
-	default y if !PREEMPTION && SMP
+	default y if SMP
 	help
 	  This option selects the RCU implementation that is
 	  designed for very large SMP system with hundreds or
@@ -17,6 +17,7 @@
 config PREEMPT_RCU
 	bool
 	default y if PREEMPTION
+	select TREE_RCU
 	help
 	  This option selects the RCU implementation that is
 	  designed for very large SMP systems with hundreds or
@@ -69,16 +70,40 @@
 	help
 	  This option selects the full-fledged version of SRCU.
 
+config TASKS_RCU_GENERIC
+	def_bool TASKS_RCU || TASKS_RUDE_RCU || TASKS_TRACE_RCU
+	select SRCU
+	help
+	  This option enables generic infrastructure code supporting
+	  task-based RCU implementations.  Not for manual selection.
+
 config TASKS_RCU
 	def_bool PREEMPTION
-	select SRCU
 	help
 	  This option enables a task-based RCU implementation that uses
 	  only voluntary context switch (not preemption!), idle, and
-	  user-mode execution as quiescent states.
+	  user-mode execution as quiescent states.  Not for manual selection.
+
+config TASKS_RUDE_RCU
+	def_bool 0
+	help
+	  This option enables a task-based RCU implementation that uses
+	  only context switch (including preemption) and user-mode
+	  execution as quiescent states.  It forces IPIs and context
+	  switches on all online CPUs, including idle ones, so use
+	  with caution.
+
+config TASKS_TRACE_RCU
+	def_bool 0
+	help
+	  This option enables a task-based RCU implementation that uses
+	  explicit rcu_read_lock_trace() read-side markers, and allows
+	  these readers to appear in the idle loop as well as on the CPU
+	  hotplug code paths.  It can force IPIs on online CPUs, including
+	  idle ones, so use with caution.
 
 config RCU_STALL_COMMON
-	def_bool ( TREE_RCU || PREEMPT_RCU )
+	def_bool TREE_RCU
 	help
 	  This option enables RCU CPU stall code that is common between
 	  the TINY and TREE variants of RCU.  The purpose is to allow
@@ -86,13 +111,13 @@
 	  making these warnings mandatory for the tree variants.
 
 config RCU_NEED_SEGCBLIST
-	def_bool ( TREE_RCU || PREEMPT_RCU || TREE_SRCU )
+	def_bool ( TREE_RCU || TREE_SRCU )
 
 config RCU_FANOUT
 	int "Tree-based hierarchical RCU fanout value"
 	range 2 64 if 64BIT
 	range 2 32 if !64BIT
-	depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
+	depends on TREE_RCU && RCU_EXPERT
 	default 64 if 64BIT
 	default 32 if !64BIT
 	help
@@ -110,10 +135,12 @@
 
 config RCU_FANOUT_LEAF
 	int "Tree-based hierarchical RCU leaf-level fanout value"
-	range 2 64 if 64BIT
-	range 2 32 if !64BIT
-	depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
-	default 16
+	range 2 64 if 64BIT && !RCU_STRICT_GRACE_PERIOD
+	range 2 32 if !64BIT && !RCU_STRICT_GRACE_PERIOD
+	range 2 3 if RCU_STRICT_GRACE_PERIOD
+	depends on TREE_RCU && RCU_EXPERT
+	default 16 if !RCU_STRICT_GRACE_PERIOD
+	default 2 if RCU_STRICT_GRACE_PERIOD
 	help
 	  This option controls the leaf-level fanout of hierarchical
 	  implementations of RCU, and allows trading off cache misses
@@ -187,7 +214,7 @@
 
 config RCU_NOCB_CPU
 	bool "Offload RCU callback processing from boot-selected CPUs"
-	depends on TREE_RCU || PREEMPT_RCU
+	depends on TREE_RCU
 	depends on RCU_EXPERT || NO_HZ_FULL
 	default n
 	help
@@ -200,8 +227,8 @@
 	  specified at boot time by the rcu_nocbs parameter.  For each
 	  such CPU, a kthread ("rcuox/N") will be created to invoke
 	  callbacks, where the "N" is the CPU being offloaded, and where
-	  the "p" for RCU-preempt (PREEMPT kernels) and "s" for RCU-sched
-	  (!PREEMPT kernels).  Nothing prevents this kthread from running
+	  the "p" for RCU-preempt (PREEMPTION kernels) and "s" for RCU-sched
+	  (!PREEMPTION kernels).  Nothing prevents this kthread from running
 	  on the specified CPUs, but (1) the kthreads may be preempted
 	  between each callback, and (2) affinity or cgroups can be used
 	  to force the kthreads to run on whatever set of CPUs is desired.
@@ -209,4 +236,22 @@
 	  Say Y here if you want to help to debug reduced OS jitter.
 	  Say N here if you are unsure.
 
+config TASKS_TRACE_RCU_READ_MB
+	bool "Tasks Trace RCU readers use memory barriers in user and idle"
+	depends on RCU_EXPERT
+	default PREEMPT_RT || NR_CPUS < 8
+	help
+	  Use this option to further reduce the number of IPIs sent
+	  to CPUs executing in userspace or idle during tasks trace
+	  RCU grace periods.  Given that a reasonable setting of
+	  the rcupdate.rcu_task_ipi_delay kernel boot parameter
+	  eliminates such IPIs for many workloads, proper setting
+	  of this Kconfig option is important mostly for aggressive
+	  real-time installations and for battery-powered devices,
+	  hence the default chosen above.
+
+	  Say Y here if you hate IPIs.
+	  Say N here if you hate read-side memory barriers.
+	  Take the default if you are unsure.
+
 endmenu # "RCU Subsystem"
diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
index 4aa02ee..1942c1f 100644
--- a/kernel/rcu/Kconfig.debug
+++ b/kernel/rcu/Kconfig.debug
@@ -23,12 +23,14 @@
 	tristate
 	default n
 
-config RCU_PERF_TEST
+config RCU_SCALE_TEST
 	tristate "performance tests for RCU"
 	depends on DEBUG_KERNEL
 	select TORTURE_TEST
 	select SRCU
 	select TASKS_RCU
+	select TASKS_RUDE_RCU
+	select TASKS_TRACE_RCU
 	default n
 	help
 	  This option provides a kernel module that runs performance
@@ -46,6 +48,8 @@
 	select TORTURE_TEST
 	select SRCU
 	select TASKS_RCU
+	select TASKS_RUDE_RCU
+	select TASKS_TRACE_RCU
 	default n
 	help
 	  This option provides a kernel module that runs torture tests
@@ -57,6 +61,25 @@
 	  Say M if you want the RCU torture tests to build as a module.
 	  Say N if you are unsure.
 
+config RCU_REF_SCALE_TEST
+	tristate "Scalability tests for read-side synchronization (RCU and others)"
+	depends on DEBUG_KERNEL
+	select TORTURE_TEST
+	select SRCU
+	select TASKS_RCU
+	select TASKS_RUDE_RCU
+	select TASKS_TRACE_RCU
+	default n
+	help
+	  This option provides a kernel module that runs performance tests
+	  useful comparing RCU with various read-side synchronization mechanisms.
+	  The kernel module may be built after the fact on the running kernel to be
+	  tested, if desired.
+
+	  Say Y here if you want these performance tests built into the kernel.
+	  Say M if you want to build it as a module instead.
+	  Say N if you are unsure.
+
 config RCU_CPU_STALL_TIMEOUT
 	int "RCU CPU stall timeout in seconds"
 	depends on RCU_STALL_COMMON
@@ -91,4 +114,19 @@
 	  Say N here if you need ultimate kernel/user switch latencies
 	  Say Y if you are unsure
 
+config RCU_STRICT_GRACE_PERIOD
+	bool "Provide debug RCU implementation with short grace periods"
+	depends on DEBUG_KERNEL && RCU_EXPERT
+	default n
+	select PREEMPT_COUNT if PREEMPT=n
+	help
+	  Select this option to build an RCU variant that is strict about
+	  grace periods, making them as short as it can.  This limits
+	  scalability, destroys real-time response, degrades battery
+	  lifetime and kills performance.  Don't try this on large
+	  machines, as in systems with more than about 10 or 20 CPUs.
+	  But in conjunction with tools like KASAN, it can be helpful
+	  when looking for certain types of RCU usage bugs, for example,
+	  too-short RCU read-side critical sections.
+
 endmenu # "RCU Debugging"
diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile
index 020e8b6..0cfb009 100644
--- a/kernel/rcu/Makefile
+++ b/kernel/rcu/Makefile
@@ -3,12 +3,16 @@
 # and is generally not a function of system call inputs.
 KCOV_INSTRUMENT := n
 
+ifeq ($(CONFIG_KCSAN),y)
+KBUILD_CFLAGS += -g -fno-omit-frame-pointer
+endif
+
 obj-y += update.o sync.o
 obj-$(CONFIG_TREE_SRCU) += srcutree.o
 obj-$(CONFIG_TINY_SRCU) += srcutiny.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
-obj-$(CONFIG_RCU_PERF_TEST) += rcuperf.o
+obj-$(CONFIG_RCU_SCALE_TEST) += rcuscale.o
+obj-$(CONFIG_RCU_REF_SCALE_TEST) += refscale.o
 obj-$(CONFIG_TREE_RCU) += tree.o
-obj-$(CONFIG_PREEMPT_RCU) += tree.o
 obj-$(CONFIG_TINY_RCU) += tiny.o
 obj-$(CONFIG_RCU_NEED_SEGCBLIST) += rcu_segcblist.o
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 7fd1c18..fcf95d1 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -167,7 +167,7 @@
 # define STATE_RCU_HEAD_READY	0
 # define STATE_RCU_HEAD_QUEUED	1
 
-extern struct debug_obj_descr rcuhead_debug_descr;
+extern const struct debug_obj_descr rcuhead_debug_descr;
 
 static inline int debug_rcu_head_queue(struct rcu_head *head)
 {
@@ -198,31 +198,11 @@
 }
 #endif	/* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
 
-void kfree(const void *);
+extern int rcu_cpu_stall_suppress_at_boot;
 
-/*
- * Reclaim the specified callback, either by invoking it (non-lazy case)
- * or freeing it directly (lazy case).  Return true if lazy, false otherwise.
- */
-static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head)
+static inline bool rcu_stall_is_suppressed_at_boot(void)
 {
-	rcu_callback_t f;
-	unsigned long offset = (unsigned long)head->func;
-
-	rcu_lock_acquire(&rcu_callback_map);
-	if (__is_kfree_rcu_offset(offset)) {
-		trace_rcu_invoke_kfree_callback(rn, head, offset);
-		kfree((void *)head - offset);
-		rcu_lock_release(&rcu_callback_map);
-		return true;
-	} else {
-		trace_rcu_invoke_callback(rn, head);
-		f = head->func;
-		WRITE_ONCE(head->func, (rcu_callback_t)0L);
-		f(head);
-		rcu_lock_release(&rcu_callback_map);
-		return false;
-	}
+	return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended();
 }
 
 #ifdef CONFIG_RCU_STALL_COMMON
@@ -232,6 +212,11 @@
 extern int rcu_cpu_stall_timeout;
 int rcu_jiffies_till_stall_check(void);
 
+static inline bool rcu_stall_is_suppressed(void)
+{
+	return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress;
+}
+
 #define rcu_ftrace_dump_stall_suppress() \
 do { \
 	if (!rcu_cpu_stall_suppress) \
@@ -245,6 +230,11 @@
 } while (0)
 
 #else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */
+
+static inline bool rcu_stall_is_suppressed(void)
+{
+	return rcu_stall_is_suppressed_at_boot();
+}
 #define rcu_ftrace_dump_stall_suppress()
 #define rcu_ftrace_dump_stall_unsuppress()
 #endif /* #ifdef CONFIG_RCU_STALL_COMMON */
@@ -281,7 +271,7 @@
  */
 extern void resched_cpu(int cpu);
 
-#if defined(SRCU) || !defined(TINY_RCU)
+#if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU)
 
 #include <linux/rcu_node_tree.h>
 
@@ -299,6 +289,8 @@
 {
 	int i;
 
+	for (i = 0; i < RCU_NUM_LVLS; i++)
+		levelspread[i] = INT_MIN;
 	if (rcu_fanout_exact) {
 		levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
 		for (i = rcu_num_lvls - 2; i >= 0; i--)
@@ -352,7 +344,8 @@
  * Iterate over all possible CPUs in a leaf RCU node.
  */
 #define for_each_leaf_node_possible_cpu(rnp, cpu) \
-	for ((cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \
+	for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
+	     (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \
 	     (cpu) <= rnp->grphi; \
 	     (cpu) = cpumask_next((cpu), cpu_possible_mask))
 
@@ -362,7 +355,8 @@
 #define rcu_find_next_bit(rnp, cpu, mask) \
 	((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu)))
 #define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \
-	for ((cpu) = rcu_find_next_bit((rnp), 0, (mask)); \
+	for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
+	     (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \
 	     (cpu) <= rnp->grphi; \
 	     (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask)))
 
@@ -418,7 +412,7 @@
 #define raw_lockdep_assert_held_rcu_node(p)				\
 	lockdep_assert_held(&ACCESS_PRIVATE(p, lock))
 
-#endif /* #if defined(SRCU) || !defined(TINY_RCU) */
+#endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */
 
 #ifdef CONFIG_SRCU
 void srcu_init(void);
@@ -439,6 +433,7 @@
 void rcu_expedite_gp(void);
 void rcu_unexpedite_gp(void);
 void rcupdate_announce_bootup_oddness(void);
+void show_rcu_tasks_gp_kthreads(void);
 void rcu_request_urgent_qs_task(struct task_struct *t);
 #endif /* #else #ifdef CONFIG_TINY_RCU */
 
@@ -449,20 +444,22 @@
 enum rcutorture_type {
 	RCU_FLAVOR,
 	RCU_TASKS_FLAVOR,
+	RCU_TASKS_RUDE_FLAVOR,
+	RCU_TASKS_TRACING_FLAVOR,
 	RCU_TRIVIAL_FLAVOR,
 	SRCU_FLAVOR,
 	INVALID_RCU_FLAVOR
 };
 
-#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
+#if defined(CONFIG_TREE_RCU)
 void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
 			    unsigned long *gp_seq);
-void rcutorture_record_progress(unsigned long vernum);
 void do_trace_rcu_torture_read(const char *rcutorturename,
 			       struct rcu_head *rhp,
 			       unsigned long secs,
 			       unsigned long c_old,
 			       unsigned long c);
+void rcu_gp_set_torture_wait(int duration);
 #else
 static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
 					  int *flags, unsigned long *gp_seq)
@@ -470,7 +467,6 @@
 	*flags = 0;
 	*gp_seq = 0;
 }
-static inline void rcutorture_record_progress(unsigned long vernum) { }
 #ifdef CONFIG_RCU_TRACE
 void do_trace_rcu_torture_read(const char *rcutorturename,
 			       struct rcu_head *rhp,
@@ -481,6 +477,7 @@
 #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
 	do { } while (0)
 #endif
+static inline void rcu_gp_set_torture_wait(int duration) { }
 #endif
 
 #if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
@@ -508,6 +505,7 @@
 #endif
 
 #ifdef CONFIG_TINY_RCU
+static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; }
 static inline unsigned long rcu_get_gp_seq(void) { return 0; }
 static inline unsigned long rcu_exp_batches_completed(void) { return 0; }
 static inline unsigned long
@@ -517,6 +515,7 @@
 static inline int rcu_get_gp_kthreads_prio(void) { return 0; }
 static inline void rcu_fwd_progress_check(unsigned long j) { }
 #else /* #ifdef CONFIG_TINY_RCU */
+bool rcu_dynticks_zero_in_eqs(int cpu, int *vp);
 unsigned long rcu_get_gp_seq(void);
 unsigned long rcu_exp_batches_completed(void);
 unsigned long srcu_batches_completed(struct srcu_struct *sp);
diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c
index 495c58c..2d2a6b6 100644
--- a/kernel/rcu/rcu_segcblist.c
+++ b/kernel/rcu/rcu_segcblist.c
@@ -20,14 +20,10 @@
 	rclp->head = NULL;
 	rclp->tail = &rclp->head;
 	rclp->len = 0;
-	rclp->len_lazy = 0;
 }
 
 /*
  * Enqueue an rcu_head structure onto the specified callback list.
- * This function assumes that the callback is non-lazy because it
- * is intended for use by no-CBs CPUs, which do not distinguish
- * between lazy and non-lazy RCU callbacks.
  */
 void rcu_cblist_enqueue(struct rcu_cblist *rclp, struct rcu_head *rhp)
 {
@@ -54,7 +50,6 @@
 	else
 		drclp->tail = &drclp->head;
 	drclp->len = srclp->len;
-	drclp->len_lazy = srclp->len_lazy;
 	if (!rhp) {
 		rcu_cblist_init(srclp);
 	} else {
@@ -62,16 +57,12 @@
 		srclp->head = rhp;
 		srclp->tail = &rhp->next;
 		WRITE_ONCE(srclp->len, 1);
-		srclp->len_lazy = 0;
 	}
 }
 
 /*
  * Dequeue the oldest rcu_head structure from the specified callback
- * list.  This function assumes that the callback is non-lazy, but
- * the caller can later invoke rcu_cblist_dequeued_lazy() if it
- * finds otherwise (and if it cares about laziness).  This allows
- * different users to have different ways of determining laziness.
+ * list.
  */
 struct rcu_head *rcu_cblist_dequeue(struct rcu_cblist *rclp)
 {
@@ -88,7 +79,7 @@
 }
 
 /* Set the length of an rcu_segcblist structure. */
-void rcu_segcblist_set_len(struct rcu_segcblist *rsclp, long v)
+static void rcu_segcblist_set_len(struct rcu_segcblist *rsclp, long v)
 {
 #ifdef CONFIG_RCU_NOCB_CPU
 	atomic_long_set(&rsclp->len, v);
@@ -104,7 +95,7 @@
  * This increase is fully ordered with respect to the callers accesses
  * both before and after.
  */
-void rcu_segcblist_add_len(struct rcu_segcblist *rsclp, long v)
+static void rcu_segcblist_add_len(struct rcu_segcblist *rsclp, long v)
 {
 #ifdef CONFIG_RCU_NOCB_CPU
 	smp_mb__before_atomic(); /* Up to the caller! */
@@ -134,7 +125,7 @@
  * with the actual number of callbacks on the structure.  This exchange is
  * fully ordered with respect to the callers accesses both before and after.
  */
-long rcu_segcblist_xchg_len(struct rcu_segcblist *rsclp, long v)
+static long rcu_segcblist_xchg_len(struct rcu_segcblist *rsclp, long v)
 {
 #ifdef CONFIG_RCU_NOCB_CPU
 	return atomic_long_xchg(&rsclp->len, v);
@@ -161,7 +152,6 @@
 	for (i = 0; i < RCU_CBLIST_NSEGS; i++)
 		rsclp->tails[i] = &rsclp->head;
 	rcu_segcblist_set_len(rsclp, 0);
-	rsclp->len_lazy = 0;
 	rsclp->enabled = 1;
 }
 
@@ -173,7 +163,6 @@
 {
 	WARN_ON_ONCE(!rcu_segcblist_empty(rsclp));
 	WARN_ON_ONCE(rcu_segcblist_n_cbs(rsclp));
-	WARN_ON_ONCE(rcu_segcblist_n_lazy_cbs(rsclp));
 	rsclp->enabled = 0;
 }
 
@@ -193,7 +182,7 @@
 bool rcu_segcblist_ready_cbs(struct rcu_segcblist *rsclp)
 {
 	return rcu_segcblist_is_enabled(rsclp) &&
-	       &rsclp->head != rsclp->tails[RCU_DONE_TAIL];
+	       &rsclp->head != READ_ONCE(rsclp->tails[RCU_DONE_TAIL]);
 }
 
 /*
@@ -253,11 +242,9 @@
  * absolutely not OK for it to ever miss posting a callback.
  */
 void rcu_segcblist_enqueue(struct rcu_segcblist *rsclp,
-			   struct rcu_head *rhp, bool lazy)
+			   struct rcu_head *rhp)
 {
 	rcu_segcblist_inc_len(rsclp);
-	if (lazy)
-		rsclp->len_lazy++;
 	smp_mb(); /* Ensure counts are updated before callback is enqueued. */
 	rhp->next = NULL;
 	WRITE_ONCE(*rsclp->tails[RCU_NEXT_TAIL], rhp);
@@ -275,15 +262,13 @@
  * period.  You have been warned.
  */
 bool rcu_segcblist_entrain(struct rcu_segcblist *rsclp,
-			   struct rcu_head *rhp, bool lazy)
+			   struct rcu_head *rhp)
 {
 	int i;
 
 	if (rcu_segcblist_n_cbs(rsclp) == 0)
 		return false;
 	rcu_segcblist_inc_len(rsclp);
-	if (lazy)
-		rsclp->len_lazy++;
 	smp_mb(); /* Ensure counts are updated before callback is entrained. */
 	rhp->next = NULL;
 	for (i = RCU_NEXT_TAIL; i > RCU_DONE_TAIL; i--)
@@ -307,8 +292,6 @@
 void rcu_segcblist_extract_count(struct rcu_segcblist *rsclp,
 					       struct rcu_cblist *rclp)
 {
-	rclp->len_lazy += rsclp->len_lazy;
-	rsclp->len_lazy = 0;
 	rclp->len = rcu_segcblist_xchg_len(rsclp, 0);
 }
 
@@ -361,9 +344,7 @@
 void rcu_segcblist_insert_count(struct rcu_segcblist *rsclp,
 				struct rcu_cblist *rclp)
 {
-	rsclp->len_lazy += rclp->len_lazy;
 	rcu_segcblist_add_len(rsclp, rclp->len);
-	rclp->len_lazy = 0;
 	rclp->len = 0;
 }
 
@@ -400,8 +381,6 @@
 		return; /* Nothing to do. */
 	WRITE_ONCE(*rsclp->tails[RCU_NEXT_TAIL], rclp->head);
 	WRITE_ONCE(rsclp->tails[RCU_NEXT_TAIL], rclp->tail);
-	rclp->head = NULL;
-	rclp->tail = &rclp->head;
 }
 
 /*
@@ -496,8 +475,16 @@
 	 * Also advance to the oldest segment of callbacks whose
 	 * ->gp_seq[] completion is at or after that passed in via "seq",
 	 * skipping any empty segments.
+	 *
+	 * Note that segment "i" (and any lower-numbered segments
+	 * containing older callbacks) will be unaffected, and their
+	 * grace-period numbers remain unchanged.  For example, if i ==
+	 * WAIT_TAIL, then neither WAIT_TAIL nor DONE_TAIL will be touched.
+	 * Instead, the CBs in NEXT_TAIL will be merged with those in
+	 * NEXT_READY_TAIL and the grace-period number of NEXT_READY_TAIL
+	 * would be updated.  NEXT_TAIL would then be empty.
 	 */
-	if (++i >= RCU_NEXT_TAIL)
+	if (rcu_segcblist_restempty(rsclp, i) || ++i >= RCU_NEXT_TAIL)
 		return false;
 
 	/*
diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index 815c2fd..5c293af 100644
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -15,15 +15,6 @@
 	return READ_ONCE(rclp->len);
 }
 
-/*
- * Account for the fact that a previously dequeued callback turned out
- * to be marked as lazy.
- */
-static inline void rcu_cblist_dequeued_lazy(struct rcu_cblist *rclp)
-{
-	rclp->len_lazy--;
-}
-
 void rcu_cblist_init(struct rcu_cblist *rclp);
 void rcu_cblist_enqueue(struct rcu_cblist *rclp, struct rcu_head *rhp);
 void rcu_cblist_flush_enqueue(struct rcu_cblist *drclp,
@@ -59,18 +50,6 @@
 #endif
 }
 
-/* Return number of lazy callbacks in segmented callback list. */
-static inline long rcu_segcblist_n_lazy_cbs(struct rcu_segcblist *rsclp)
-{
-	return rsclp->len_lazy;
-}
-
-/* Return number of lazy callbacks in segmented callback list. */
-static inline long rcu_segcblist_n_nonlazy_cbs(struct rcu_segcblist *rsclp)
-{
-	return rcu_segcblist_n_cbs(rsclp) - rsclp->len_lazy;
-}
-
 /*
  * Is the specified rcu_segcblist enabled, for example, not corresponding
  * to an offline CPU?
@@ -106,9 +85,9 @@
 struct rcu_head *rcu_segcblist_first_pend_cb(struct rcu_segcblist *rsclp);
 bool rcu_segcblist_nextgp(struct rcu_segcblist *rsclp, unsigned long *lp);
 void rcu_segcblist_enqueue(struct rcu_segcblist *rsclp,
-			   struct rcu_head *rhp, bool lazy);
+			   struct rcu_head *rhp);
 bool rcu_segcblist_entrain(struct rcu_segcblist *rsclp,
-			   struct rcu_head *rhp, bool lazy);
+			   struct rcu_head *rhp);
 void rcu_segcblist_extract_count(struct rcu_segcblist *rsclp,
 				 struct rcu_cblist *rclp);
 void rcu_segcblist_extract_done_cbs(struct rcu_segcblist *rsclp,
diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
deleted file mode 100644
index 5a879d0..0000000
--- a/kernel/rcu/rcuperf.c
+++ /dev/null
@@ -1,702 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Read-Copy Update module-based performance-test facility
- *
- * Copyright (C) IBM Corporation, 2015
- *
- * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
- */
-
-#define pr_fmt(fmt) fmt
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/kthread.h>
-#include <linux/err.h>
-#include <linux/spinlock.h>
-#include <linux/smp.h>
-#include <linux/rcupdate.h>
-#include <linux/interrupt.h>
-#include <linux/sched.h>
-#include <uapi/linux/sched/types.h>
-#include <linux/atomic.h>
-#include <linux/bitops.h>
-#include <linux/completion.h>
-#include <linux/moduleparam.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/reboot.h>
-#include <linux/freezer.h>
-#include <linux/cpu.h>
-#include <linux/delay.h>
-#include <linux/stat.h>
-#include <linux/srcu.h>
-#include <linux/slab.h>
-#include <asm/byteorder.h>
-#include <linux/torture.h>
-#include <linux/vmalloc.h>
-
-#include "rcu.h"
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
-
-#define PERF_FLAG "-perf:"
-#define PERFOUT_STRING(s) \
-	pr_alert("%s" PERF_FLAG " %s\n", perf_type, s)
-#define VERBOSE_PERFOUT_STRING(s) \
-	do { if (verbose) pr_alert("%s" PERF_FLAG " %s\n", perf_type, s); } while (0)
-#define VERBOSE_PERFOUT_ERRSTRING(s) \
-	do { if (verbose) pr_alert("%s" PERF_FLAG "!!! %s\n", perf_type, s); } while (0)
-
-/*
- * The intended use cases for the nreaders and nwriters module parameters
- * are as follows:
- *
- * 1.	Specify only the nr_cpus kernel boot parameter.  This will
- *	set both nreaders and nwriters to the value specified by
- *	nr_cpus for a mixed reader/writer test.
- *
- * 2.	Specify the nr_cpus kernel boot parameter, but set
- *	rcuperf.nreaders to zero.  This will set nwriters to the
- *	value specified by nr_cpus for an update-only test.
- *
- * 3.	Specify the nr_cpus kernel boot parameter, but set
- *	rcuperf.nwriters to zero.  This will set nreaders to the
- *	value specified by nr_cpus for a read-only test.
- *
- * Various other use cases may of course be specified.
- */
-
-#ifdef MODULE
-# define RCUPERF_SHUTDOWN 0
-#else
-# define RCUPERF_SHUTDOWN 1
-#endif
-
-torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives");
-torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader");
-torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
-torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
-torture_param(int, nreaders, -1, "Number of RCU reader threads");
-torture_param(int, nwriters, -1, "Number of RCU updater threads");
-torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
-	      "Shutdown at end of performance tests.");
-torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
-torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
-
-static char *perf_type = "rcu";
-module_param(perf_type, charp, 0444);
-MODULE_PARM_DESC(perf_type, "Type of RCU to performance-test (rcu, srcu, ...)");
-
-static int nrealreaders;
-static int nrealwriters;
-static struct task_struct **writer_tasks;
-static struct task_struct **reader_tasks;
-static struct task_struct *shutdown_task;
-
-static u64 **writer_durations;
-static int *writer_n_durations;
-static atomic_t n_rcu_perf_reader_started;
-static atomic_t n_rcu_perf_writer_started;
-static atomic_t n_rcu_perf_writer_finished;
-static wait_queue_head_t shutdown_wq;
-static u64 t_rcu_perf_writer_started;
-static u64 t_rcu_perf_writer_finished;
-static unsigned long b_rcu_perf_writer_started;
-static unsigned long b_rcu_perf_writer_finished;
-static DEFINE_PER_CPU(atomic_t, n_async_inflight);
-
-static int rcu_perf_writer_state;
-#define RTWS_INIT		0
-#define RTWS_ASYNC		1
-#define RTWS_BARRIER		2
-#define RTWS_EXP_SYNC		3
-#define RTWS_SYNC		4
-#define RTWS_IDLE		5
-#define RTWS_STOPPING		6
-
-#define MAX_MEAS 10000
-#define MIN_MEAS 100
-
-/*
- * Operations vector for selecting different types of tests.
- */
-
-struct rcu_perf_ops {
-	int ptype;
-	void (*init)(void);
-	void (*cleanup)(void);
-	int (*readlock)(void);
-	void (*readunlock)(int idx);
-	unsigned long (*get_gp_seq)(void);
-	unsigned long (*gp_diff)(unsigned long new, unsigned long old);
-	unsigned long (*exp_completed)(void);
-	void (*async)(struct rcu_head *head, rcu_callback_t func);
-	void (*gp_barrier)(void);
-	void (*sync)(void);
-	void (*exp_sync)(void);
-	const char *name;
-};
-
-static struct rcu_perf_ops *cur_ops;
-
-/*
- * Definitions for rcu perf testing.
- */
-
-static int rcu_perf_read_lock(void) __acquires(RCU)
-{
-	rcu_read_lock();
-	return 0;
-}
-
-static void rcu_perf_read_unlock(int idx) __releases(RCU)
-{
-	rcu_read_unlock();
-}
-
-static unsigned long __maybe_unused rcu_no_completed(void)
-{
-	return 0;
-}
-
-static void rcu_sync_perf_init(void)
-{
-}
-
-static struct rcu_perf_ops rcu_ops = {
-	.ptype		= RCU_FLAVOR,
-	.init		= rcu_sync_perf_init,
-	.readlock	= rcu_perf_read_lock,
-	.readunlock	= rcu_perf_read_unlock,
-	.get_gp_seq	= rcu_get_gp_seq,
-	.gp_diff	= rcu_seq_diff,
-	.exp_completed	= rcu_exp_batches_completed,
-	.async		= call_rcu,
-	.gp_barrier	= rcu_barrier,
-	.sync		= synchronize_rcu,
-	.exp_sync	= synchronize_rcu_expedited,
-	.name		= "rcu"
-};
-
-/*
- * Definitions for srcu perf testing.
- */
-
-DEFINE_STATIC_SRCU(srcu_ctl_perf);
-static struct srcu_struct *srcu_ctlp = &srcu_ctl_perf;
-
-static int srcu_perf_read_lock(void) __acquires(srcu_ctlp)
-{
-	return srcu_read_lock(srcu_ctlp);
-}
-
-static void srcu_perf_read_unlock(int idx) __releases(srcu_ctlp)
-{
-	srcu_read_unlock(srcu_ctlp, idx);
-}
-
-static unsigned long srcu_perf_completed(void)
-{
-	return srcu_batches_completed(srcu_ctlp);
-}
-
-static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func)
-{
-	call_srcu(srcu_ctlp, head, func);
-}
-
-static void srcu_rcu_barrier(void)
-{
-	srcu_barrier(srcu_ctlp);
-}
-
-static void srcu_perf_synchronize(void)
-{
-	synchronize_srcu(srcu_ctlp);
-}
-
-static void srcu_perf_synchronize_expedited(void)
-{
-	synchronize_srcu_expedited(srcu_ctlp);
-}
-
-static struct rcu_perf_ops srcu_ops = {
-	.ptype		= SRCU_FLAVOR,
-	.init		= rcu_sync_perf_init,
-	.readlock	= srcu_perf_read_lock,
-	.readunlock	= srcu_perf_read_unlock,
-	.get_gp_seq	= srcu_perf_completed,
-	.gp_diff	= rcu_seq_diff,
-	.exp_completed	= srcu_perf_completed,
-	.async		= srcu_call_rcu,
-	.gp_barrier	= srcu_rcu_barrier,
-	.sync		= srcu_perf_synchronize,
-	.exp_sync	= srcu_perf_synchronize_expedited,
-	.name		= "srcu"
-};
-
-static struct srcu_struct srcud;
-
-static void srcu_sync_perf_init(void)
-{
-	srcu_ctlp = &srcud;
-	init_srcu_struct(srcu_ctlp);
-}
-
-static void srcu_sync_perf_cleanup(void)
-{
-	cleanup_srcu_struct(srcu_ctlp);
-}
-
-static struct rcu_perf_ops srcud_ops = {
-	.ptype		= SRCU_FLAVOR,
-	.init		= srcu_sync_perf_init,
-	.cleanup	= srcu_sync_perf_cleanup,
-	.readlock	= srcu_perf_read_lock,
-	.readunlock	= srcu_perf_read_unlock,
-	.get_gp_seq	= srcu_perf_completed,
-	.gp_diff	= rcu_seq_diff,
-	.exp_completed	= srcu_perf_completed,
-	.async		= srcu_call_rcu,
-	.gp_barrier	= srcu_rcu_barrier,
-	.sync		= srcu_perf_synchronize,
-	.exp_sync	= srcu_perf_synchronize_expedited,
-	.name		= "srcud"
-};
-
-/*
- * Definitions for RCU-tasks perf testing.
- */
-
-static int tasks_perf_read_lock(void)
-{
-	return 0;
-}
-
-static void tasks_perf_read_unlock(int idx)
-{
-}
-
-static struct rcu_perf_ops tasks_ops = {
-	.ptype		= RCU_TASKS_FLAVOR,
-	.init		= rcu_sync_perf_init,
-	.readlock	= tasks_perf_read_lock,
-	.readunlock	= tasks_perf_read_unlock,
-	.get_gp_seq	= rcu_no_completed,
-	.gp_diff	= rcu_seq_diff,
-	.async		= call_rcu_tasks,
-	.gp_barrier	= rcu_barrier_tasks,
-	.sync		= synchronize_rcu_tasks,
-	.exp_sync	= synchronize_rcu_tasks,
-	.name		= "tasks"
-};
-
-static unsigned long rcuperf_seq_diff(unsigned long new, unsigned long old)
-{
-	if (!cur_ops->gp_diff)
-		return new - old;
-	return cur_ops->gp_diff(new, old);
-}
-
-/*
- * If performance tests complete, wait for shutdown to commence.
- */
-static void rcu_perf_wait_shutdown(void)
-{
-	cond_resched_tasks_rcu_qs();
-	if (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters)
-		return;
-	while (!torture_must_stop())
-		schedule_timeout_uninterruptible(1);
-}
-
-/*
- * RCU perf reader kthread.  Repeatedly does empty RCU read-side
- * critical section, minimizing update-side interference.
- */
-static int
-rcu_perf_reader(void *arg)
-{
-	unsigned long flags;
-	int idx;
-	long me = (long)arg;
-
-	VERBOSE_PERFOUT_STRING("rcu_perf_reader task started");
-	set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
-	set_user_nice(current, MAX_NICE);
-	atomic_inc(&n_rcu_perf_reader_started);
-
-	do {
-		local_irq_save(flags);
-		idx = cur_ops->readlock();
-		cur_ops->readunlock(idx);
-		local_irq_restore(flags);
-		rcu_perf_wait_shutdown();
-	} while (!torture_must_stop());
-	torture_kthread_stopping("rcu_perf_reader");
-	return 0;
-}
-
-/*
- * Callback function for asynchronous grace periods from rcu_perf_writer().
- */
-static void rcu_perf_async_cb(struct rcu_head *rhp)
-{
-	atomic_dec(this_cpu_ptr(&n_async_inflight));
-	kfree(rhp);
-}
-
-/*
- * RCU perf writer kthread.  Repeatedly does a grace period.
- */
-static int
-rcu_perf_writer(void *arg)
-{
-	int i = 0;
-	int i_max;
-	long me = (long)arg;
-	struct rcu_head *rhp = NULL;
-	struct sched_param sp;
-	bool started = false, done = false, alldone = false;
-	u64 t;
-	u64 *wdp;
-	u64 *wdpp = writer_durations[me];
-
-	VERBOSE_PERFOUT_STRING("rcu_perf_writer task started");
-	WARN_ON(!wdpp);
-	set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
-	sp.sched_priority = 1;
-	sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
-
-	if (holdoff)
-		schedule_timeout_uninterruptible(holdoff * HZ);
-
-	/*
-	 * Wait until rcu_end_inkernel_boot() is called for normal GP tests
-	 * so that RCU is not always expedited for normal GP tests.
-	 * The system_state test is approximate, but works well in practice.
-	 */
-	while (!gp_exp && system_state != SYSTEM_RUNNING)
-		schedule_timeout_uninterruptible(1);
-
-	t = ktime_get_mono_fast_ns();
-	if (atomic_inc_return(&n_rcu_perf_writer_started) >= nrealwriters) {
-		t_rcu_perf_writer_started = t;
-		if (gp_exp) {
-			b_rcu_perf_writer_started =
-				cur_ops->exp_completed() / 2;
-		} else {
-			b_rcu_perf_writer_started = cur_ops->get_gp_seq();
-		}
-	}
-
-	do {
-		if (writer_holdoff)
-			udelay(writer_holdoff);
-		wdp = &wdpp[i];
-		*wdp = ktime_get_mono_fast_ns();
-		if (gp_async) {
-retry:
-			if (!rhp)
-				rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
-			if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) {
-				rcu_perf_writer_state = RTWS_ASYNC;
-				atomic_inc(this_cpu_ptr(&n_async_inflight));
-				cur_ops->async(rhp, rcu_perf_async_cb);
-				rhp = NULL;
-			} else if (!kthread_should_stop()) {
-				rcu_perf_writer_state = RTWS_BARRIER;
-				cur_ops->gp_barrier();
-				goto retry;
-			} else {
-				kfree(rhp); /* Because we are stopping. */
-			}
-		} else if (gp_exp) {
-			rcu_perf_writer_state = RTWS_EXP_SYNC;
-			cur_ops->exp_sync();
-		} else {
-			rcu_perf_writer_state = RTWS_SYNC;
-			cur_ops->sync();
-		}
-		rcu_perf_writer_state = RTWS_IDLE;
-		t = ktime_get_mono_fast_ns();
-		*wdp = t - *wdp;
-		i_max = i;
-		if (!started &&
-		    atomic_read(&n_rcu_perf_writer_started) >= nrealwriters)
-			started = true;
-		if (!done && i >= MIN_MEAS) {
-			done = true;
-			sp.sched_priority = 0;
-			sched_setscheduler_nocheck(current,
-						   SCHED_NORMAL, &sp);
-			pr_alert("%s%s rcu_perf_writer %ld has %d measurements\n",
-				 perf_type, PERF_FLAG, me, MIN_MEAS);
-			if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
-			    nrealwriters) {
-				schedule_timeout_interruptible(10);
-				rcu_ftrace_dump(DUMP_ALL);
-				PERFOUT_STRING("Test complete");
-				t_rcu_perf_writer_finished = t;
-				if (gp_exp) {
-					b_rcu_perf_writer_finished =
-						cur_ops->exp_completed() / 2;
-				} else {
-					b_rcu_perf_writer_finished =
-						cur_ops->get_gp_seq();
-				}
-				if (shutdown) {
-					smp_mb(); /* Assign before wake. */
-					wake_up(&shutdown_wq);
-				}
-			}
-		}
-		if (done && !alldone &&
-		    atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters)
-			alldone = true;
-		if (started && !alldone && i < MAX_MEAS - 1)
-			i++;
-		rcu_perf_wait_shutdown();
-	} while (!torture_must_stop());
-	if (gp_async) {
-		rcu_perf_writer_state = RTWS_BARRIER;
-		cur_ops->gp_barrier();
-	}
-	rcu_perf_writer_state = RTWS_STOPPING;
-	writer_n_durations[me] = i_max;
-	torture_kthread_stopping("rcu_perf_writer");
-	return 0;
-}
-
-static void
-rcu_perf_print_module_parms(struct rcu_perf_ops *cur_ops, const char *tag)
-{
-	pr_alert("%s" PERF_FLAG
-		 "--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n",
-		 perf_type, tag, nrealreaders, nrealwriters, verbose, shutdown);
-}
-
-static void
-rcu_perf_cleanup(void)
-{
-	int i;
-	int j;
-	int ngps = 0;
-	u64 *wdp;
-	u64 *wdpp;
-
-	/*
-	 * Would like warning at start, but everything is expedited
-	 * during the mid-boot phase, so have to wait till the end.
-	 */
-	if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp)
-		VERBOSE_PERFOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
-	if (rcu_gp_is_normal() && gp_exp)
-		VERBOSE_PERFOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
-	if (gp_exp && gp_async)
-		VERBOSE_PERFOUT_ERRSTRING("No expedited async GPs, so went with async!");
-
-	if (torture_cleanup_begin())
-		return;
-	if (!cur_ops) {
-		torture_cleanup_end();
-		return;
-	}
-
-	if (reader_tasks) {
-		for (i = 0; i < nrealreaders; i++)
-			torture_stop_kthread(rcu_perf_reader,
-					     reader_tasks[i]);
-		kfree(reader_tasks);
-	}
-
-	if (writer_tasks) {
-		for (i = 0; i < nrealwriters; i++) {
-			torture_stop_kthread(rcu_perf_writer,
-					     writer_tasks[i]);
-			if (!writer_n_durations)
-				continue;
-			j = writer_n_durations[i];
-			pr_alert("%s%s writer %d gps: %d\n",
-				 perf_type, PERF_FLAG, i, j);
-			ngps += j;
-		}
-		pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n",
-			 perf_type, PERF_FLAG,
-			 t_rcu_perf_writer_started, t_rcu_perf_writer_finished,
-			 t_rcu_perf_writer_finished -
-			 t_rcu_perf_writer_started,
-			 ngps,
-			 rcuperf_seq_diff(b_rcu_perf_writer_finished,
-					  b_rcu_perf_writer_started));
-		for (i = 0; i < nrealwriters; i++) {
-			if (!writer_durations)
-				break;
-			if (!writer_n_durations)
-				continue;
-			wdpp = writer_durations[i];
-			if (!wdpp)
-				continue;
-			for (j = 0; j <= writer_n_durations[i]; j++) {
-				wdp = &wdpp[j];
-				pr_alert("%s%s %4d writer-duration: %5d %llu\n",
-					perf_type, PERF_FLAG,
-					i, j, *wdp);
-				if (j % 100 == 0)
-					schedule_timeout_uninterruptible(1);
-			}
-			kfree(writer_durations[i]);
-		}
-		kfree(writer_tasks);
-		kfree(writer_durations);
-		kfree(writer_n_durations);
-	}
-
-	/* Do torture-type-specific cleanup operations.  */
-	if (cur_ops->cleanup != NULL)
-		cur_ops->cleanup();
-
-	torture_cleanup_end();
-}
-
-/*
- * Return the number if non-negative.  If -1, the number of CPUs.
- * If less than -1, that much less than the number of CPUs, but
- * at least one.
- */
-static int compute_real(int n)
-{
-	int nr;
-
-	if (n >= 0) {
-		nr = n;
-	} else {
-		nr = num_online_cpus() + 1 + n;
-		if (nr <= 0)
-			nr = 1;
-	}
-	return nr;
-}
-
-/*
- * RCU perf shutdown kthread.  Just waits to be awakened, then shuts
- * down system.
- */
-static int
-rcu_perf_shutdown(void *arg)
-{
-	do {
-		wait_event(shutdown_wq,
-			   atomic_read(&n_rcu_perf_writer_finished) >=
-			   nrealwriters);
-	} while (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters);
-	smp_mb(); /* Wake before output. */
-	rcu_perf_cleanup();
-	kernel_power_off();
-	return -EINVAL;
-}
-
-static int __init
-rcu_perf_init(void)
-{
-	long i;
-	int firsterr = 0;
-	static struct rcu_perf_ops *perf_ops[] = {
-		&rcu_ops, &srcu_ops, &srcud_ops, &tasks_ops,
-	};
-
-	if (!torture_init_begin(perf_type, verbose))
-		return -EBUSY;
-
-	/* Process args and tell the world that the perf'er is on the job. */
-	for (i = 0; i < ARRAY_SIZE(perf_ops); i++) {
-		cur_ops = perf_ops[i];
-		if (strcmp(perf_type, cur_ops->name) == 0)
-			break;
-	}
-	if (i == ARRAY_SIZE(perf_ops)) {
-		pr_alert("rcu-perf: invalid perf type: \"%s\"\n", perf_type);
-		pr_alert("rcu-perf types:");
-		for (i = 0; i < ARRAY_SIZE(perf_ops); i++)
-			pr_cont(" %s", perf_ops[i]->name);
-		pr_cont("\n");
-		WARN_ON(!IS_MODULE(CONFIG_RCU_PERF_TEST));
-		firsterr = -EINVAL;
-		cur_ops = NULL;
-		goto unwind;
-	}
-	if (cur_ops->init)
-		cur_ops->init();
-
-	nrealwriters = compute_real(nwriters);
-	nrealreaders = compute_real(nreaders);
-	atomic_set(&n_rcu_perf_reader_started, 0);
-	atomic_set(&n_rcu_perf_writer_started, 0);
-	atomic_set(&n_rcu_perf_writer_finished, 0);
-	rcu_perf_print_module_parms(cur_ops, "Start of test");
-
-	/* Start up the kthreads. */
-
-	if (shutdown) {
-		init_waitqueue_head(&shutdown_wq);
-		firsterr = torture_create_kthread(rcu_perf_shutdown, NULL,
-						  shutdown_task);
-		if (firsterr)
-			goto unwind;
-		schedule_timeout_uninterruptible(1);
-	}
-	reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
-			       GFP_KERNEL);
-	if (reader_tasks == NULL) {
-		VERBOSE_PERFOUT_ERRSTRING("out of memory");
-		firsterr = -ENOMEM;
-		goto unwind;
-	}
-	for (i = 0; i < nrealreaders; i++) {
-		firsterr = torture_create_kthread(rcu_perf_reader, (void *)i,
-						  reader_tasks[i]);
-		if (firsterr)
-			goto unwind;
-	}
-	while (atomic_read(&n_rcu_perf_reader_started) < nrealreaders)
-		schedule_timeout_uninterruptible(1);
-	writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]),
-			       GFP_KERNEL);
-	writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations),
-				   GFP_KERNEL);
-	writer_n_durations =
-		kcalloc(nrealwriters, sizeof(*writer_n_durations),
-			GFP_KERNEL);
-	if (!writer_tasks || !writer_durations || !writer_n_durations) {
-		VERBOSE_PERFOUT_ERRSTRING("out of memory");
-		firsterr = -ENOMEM;
-		goto unwind;
-	}
-	for (i = 0; i < nrealwriters; i++) {
-		writer_durations[i] =
-			kcalloc(MAX_MEAS, sizeof(*writer_durations[i]),
-				GFP_KERNEL);
-		if (!writer_durations[i]) {
-			firsterr = -ENOMEM;
-			goto unwind;
-		}
-		firsterr = torture_create_kthread(rcu_perf_writer, (void *)i,
-						  writer_tasks[i]);
-		if (firsterr)
-			goto unwind;
-	}
-	torture_init_end();
-	return 0;
-
-unwind:
-	torture_init_end();
-	rcu_perf_cleanup();
-	return firsterr;
-}
-
-module_init(rcu_perf_init);
-module_exit(rcu_perf_cleanup);
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
new file mode 100644
index 0000000..2819b95
--- /dev/null
+++ b/kernel/rcu/rcuscale.c
@@ -0,0 +1,853 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Read-Copy Update module-based scalability-test facility
+ *
+ * Copyright (C) IBM Corporation, 2015
+ *
+ * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
+ */
+
+#define pr_fmt(fmt) fmt
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/rcupdate.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <uapi/linux/sched/types.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/freezer.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/stat.h>
+#include <linux/srcu.h>
+#include <linux/slab.h>
+#include <asm/byteorder.h>
+#include <linux/torture.h>
+#include <linux/vmalloc.h>
+
+#include "rcu.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
+
+#define SCALE_FLAG "-scale:"
+#define SCALEOUT_STRING(s) \
+	pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s)
+#define VERBOSE_SCALEOUT_STRING(s) \
+	do { if (verbose) pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s); } while (0)
+#define VERBOSE_SCALEOUT_ERRSTRING(s) \
+	do { if (verbose) pr_alert("%s" SCALE_FLAG "!!! %s\n", scale_type, s); } while (0)
+
+/*
+ * The intended use cases for the nreaders and nwriters module parameters
+ * are as follows:
+ *
+ * 1.	Specify only the nr_cpus kernel boot parameter.  This will
+ *	set both nreaders and nwriters to the value specified by
+ *	nr_cpus for a mixed reader/writer test.
+ *
+ * 2.	Specify the nr_cpus kernel boot parameter, but set
+ *	rcuscale.nreaders to zero.  This will set nwriters to the
+ *	value specified by nr_cpus for an update-only test.
+ *
+ * 3.	Specify the nr_cpus kernel boot parameter, but set
+ *	rcuscale.nwriters to zero.  This will set nreaders to the
+ *	value specified by nr_cpus for a read-only test.
+ *
+ * Various other use cases may of course be specified.
+ *
+ * Note that this test's readers are intended only as a test load for
+ * the writers.  The reader scalability statistics will be overly
+ * pessimistic due to the per-critical-section interrupt disabling,
+ * test-end checks, and the pair of calls through pointers.
+ */
+
+#ifdef MODULE
+# define RCUSCALE_SHUTDOWN 0
+#else
+# define RCUSCALE_SHUTDOWN 1
+#endif
+
+torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives");
+torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader");
+torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
+torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
+torture_param(int, nreaders, -1, "Number of RCU reader threads");
+torture_param(int, nwriters, -1, "Number of RCU updater threads");
+torture_param(bool, shutdown, RCUSCALE_SHUTDOWN,
+	      "Shutdown at end of scalability tests.");
+torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
+torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
+torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() scale test?");
+torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
+
+static char *scale_type = "rcu";
+module_param(scale_type, charp, 0444);
+MODULE_PARM_DESC(scale_type, "Type of RCU to scalability-test (rcu, srcu, ...)");
+
+static int nrealreaders;
+static int nrealwriters;
+static struct task_struct **writer_tasks;
+static struct task_struct **reader_tasks;
+static struct task_struct *shutdown_task;
+
+static u64 **writer_durations;
+static int *writer_n_durations;
+static atomic_t n_rcu_scale_reader_started;
+static atomic_t n_rcu_scale_writer_started;
+static atomic_t n_rcu_scale_writer_finished;
+static wait_queue_head_t shutdown_wq;
+static u64 t_rcu_scale_writer_started;
+static u64 t_rcu_scale_writer_finished;
+static unsigned long b_rcu_gp_test_started;
+static unsigned long b_rcu_gp_test_finished;
+static DEFINE_PER_CPU(atomic_t, n_async_inflight);
+
+#define MAX_MEAS 10000
+#define MIN_MEAS 100
+
+/*
+ * Operations vector for selecting different types of tests.
+ */
+
+struct rcu_scale_ops {
+	int ptype;
+	void (*init)(void);
+	void (*cleanup)(void);
+	int (*readlock)(void);
+	void (*readunlock)(int idx);
+	unsigned long (*get_gp_seq)(void);
+	unsigned long (*gp_diff)(unsigned long new, unsigned long old);
+	unsigned long (*exp_completed)(void);
+	void (*async)(struct rcu_head *head, rcu_callback_t func);
+	void (*gp_barrier)(void);
+	void (*sync)(void);
+	void (*exp_sync)(void);
+	const char *name;
+};
+
+static struct rcu_scale_ops *cur_ops;
+
+/*
+ * Definitions for rcu scalability testing.
+ */
+
+static int rcu_scale_read_lock(void) __acquires(RCU)
+{
+	rcu_read_lock();
+	return 0;
+}
+
+static void rcu_scale_read_unlock(int idx) __releases(RCU)
+{
+	rcu_read_unlock();
+}
+
+static unsigned long __maybe_unused rcu_no_completed(void)
+{
+	return 0;
+}
+
+static void rcu_sync_scale_init(void)
+{
+}
+
+static struct rcu_scale_ops rcu_ops = {
+	.ptype		= RCU_FLAVOR,
+	.init		= rcu_sync_scale_init,
+	.readlock	= rcu_scale_read_lock,
+	.readunlock	= rcu_scale_read_unlock,
+	.get_gp_seq	= rcu_get_gp_seq,
+	.gp_diff	= rcu_seq_diff,
+	.exp_completed	= rcu_exp_batches_completed,
+	.async		= call_rcu,
+	.gp_barrier	= rcu_barrier,
+	.sync		= synchronize_rcu,
+	.exp_sync	= synchronize_rcu_expedited,
+	.name		= "rcu"
+};
+
+/*
+ * Definitions for srcu scalability testing.
+ */
+
+DEFINE_STATIC_SRCU(srcu_ctl_scale);
+static struct srcu_struct *srcu_ctlp = &srcu_ctl_scale;
+
+static int srcu_scale_read_lock(void) __acquires(srcu_ctlp)
+{
+	return srcu_read_lock(srcu_ctlp);
+}
+
+static void srcu_scale_read_unlock(int idx) __releases(srcu_ctlp)
+{
+	srcu_read_unlock(srcu_ctlp, idx);
+}
+
+static unsigned long srcu_scale_completed(void)
+{
+	return srcu_batches_completed(srcu_ctlp);
+}
+
+static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func)
+{
+	call_srcu(srcu_ctlp, head, func);
+}
+
+static void srcu_rcu_barrier(void)
+{
+	srcu_barrier(srcu_ctlp);
+}
+
+static void srcu_scale_synchronize(void)
+{
+	synchronize_srcu(srcu_ctlp);
+}
+
+static void srcu_scale_synchronize_expedited(void)
+{
+	synchronize_srcu_expedited(srcu_ctlp);
+}
+
+static struct rcu_scale_ops srcu_ops = {
+	.ptype		= SRCU_FLAVOR,
+	.init		= rcu_sync_scale_init,
+	.readlock	= srcu_scale_read_lock,
+	.readunlock	= srcu_scale_read_unlock,
+	.get_gp_seq	= srcu_scale_completed,
+	.gp_diff	= rcu_seq_diff,
+	.exp_completed	= srcu_scale_completed,
+	.async		= srcu_call_rcu,
+	.gp_barrier	= srcu_rcu_barrier,
+	.sync		= srcu_scale_synchronize,
+	.exp_sync	= srcu_scale_synchronize_expedited,
+	.name		= "srcu"
+};
+
+static struct srcu_struct srcud;
+
+static void srcu_sync_scale_init(void)
+{
+	srcu_ctlp = &srcud;
+	init_srcu_struct(srcu_ctlp);
+}
+
+static void srcu_sync_scale_cleanup(void)
+{
+	cleanup_srcu_struct(srcu_ctlp);
+}
+
+static struct rcu_scale_ops srcud_ops = {
+	.ptype		= SRCU_FLAVOR,
+	.init		= srcu_sync_scale_init,
+	.cleanup	= srcu_sync_scale_cleanup,
+	.readlock	= srcu_scale_read_lock,
+	.readunlock	= srcu_scale_read_unlock,
+	.get_gp_seq	= srcu_scale_completed,
+	.gp_diff	= rcu_seq_diff,
+	.exp_completed	= srcu_scale_completed,
+	.async		= srcu_call_rcu,
+	.gp_barrier	= srcu_rcu_barrier,
+	.sync		= srcu_scale_synchronize,
+	.exp_sync	= srcu_scale_synchronize_expedited,
+	.name		= "srcud"
+};
+
+/*
+ * Definitions for RCU-tasks scalability testing.
+ */
+
+static int tasks_scale_read_lock(void)
+{
+	return 0;
+}
+
+static void tasks_scale_read_unlock(int idx)
+{
+}
+
+static struct rcu_scale_ops tasks_ops = {
+	.ptype		= RCU_TASKS_FLAVOR,
+	.init		= rcu_sync_scale_init,
+	.readlock	= tasks_scale_read_lock,
+	.readunlock	= tasks_scale_read_unlock,
+	.get_gp_seq	= rcu_no_completed,
+	.gp_diff	= rcu_seq_diff,
+	.async		= call_rcu_tasks,
+	.gp_barrier	= rcu_barrier_tasks,
+	.sync		= synchronize_rcu_tasks,
+	.exp_sync	= synchronize_rcu_tasks,
+	.name		= "tasks"
+};
+
+static unsigned long rcuscale_seq_diff(unsigned long new, unsigned long old)
+{
+	if (!cur_ops->gp_diff)
+		return new - old;
+	return cur_ops->gp_diff(new, old);
+}
+
+/*
+ * If scalability tests complete, wait for shutdown to commence.
+ */
+static void rcu_scale_wait_shutdown(void)
+{
+	cond_resched_tasks_rcu_qs();
+	if (atomic_read(&n_rcu_scale_writer_finished) < nrealwriters)
+		return;
+	while (!torture_must_stop())
+		schedule_timeout_uninterruptible(1);
+}
+
+/*
+ * RCU scalability reader kthread.  Repeatedly does empty RCU read-side
+ * critical section, minimizing update-side interference.  However, the
+ * point of this test is not to evaluate reader scalability, but instead
+ * to serve as a test load for update-side scalability testing.
+ */
+static int
+rcu_scale_reader(void *arg)
+{
+	unsigned long flags;
+	int idx;
+	long me = (long)arg;
+
+	VERBOSE_SCALEOUT_STRING("rcu_scale_reader task started");
+	set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
+	set_user_nice(current, MAX_NICE);
+	atomic_inc(&n_rcu_scale_reader_started);
+
+	do {
+		local_irq_save(flags);
+		idx = cur_ops->readlock();
+		cur_ops->readunlock(idx);
+		local_irq_restore(flags);
+		rcu_scale_wait_shutdown();
+	} while (!torture_must_stop());
+	torture_kthread_stopping("rcu_scale_reader");
+	return 0;
+}
+
+/*
+ * Callback function for asynchronous grace periods from rcu_scale_writer().
+ */
+static void rcu_scale_async_cb(struct rcu_head *rhp)
+{
+	atomic_dec(this_cpu_ptr(&n_async_inflight));
+	kfree(rhp);
+}
+
+/*
+ * RCU scale writer kthread.  Repeatedly does a grace period.
+ */
+static int
+rcu_scale_writer(void *arg)
+{
+	int i = 0;
+	int i_max;
+	long me = (long)arg;
+	struct rcu_head *rhp = NULL;
+	bool started = false, done = false, alldone = false;
+	u64 t;
+	u64 *wdp;
+	u64 *wdpp = writer_durations[me];
+
+	VERBOSE_SCALEOUT_STRING("rcu_scale_writer task started");
+	WARN_ON(!wdpp);
+	set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
+	sched_set_fifo_low(current);
+
+	if (holdoff)
+		schedule_timeout_uninterruptible(holdoff * HZ);
+
+	/*
+	 * Wait until rcu_end_inkernel_boot() is called for normal GP tests
+	 * so that RCU is not always expedited for normal GP tests.
+	 * The system_state test is approximate, but works well in practice.
+	 */
+	while (!gp_exp && system_state != SYSTEM_RUNNING)
+		schedule_timeout_uninterruptible(1);
+
+	t = ktime_get_mono_fast_ns();
+	if (atomic_inc_return(&n_rcu_scale_writer_started) >= nrealwriters) {
+		t_rcu_scale_writer_started = t;
+		if (gp_exp) {
+			b_rcu_gp_test_started =
+				cur_ops->exp_completed() / 2;
+		} else {
+			b_rcu_gp_test_started = cur_ops->get_gp_seq();
+		}
+	}
+
+	do {
+		if (writer_holdoff)
+			udelay(writer_holdoff);
+		wdp = &wdpp[i];
+		*wdp = ktime_get_mono_fast_ns();
+		if (gp_async) {
+retry:
+			if (!rhp)
+				rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
+			if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) {
+				atomic_inc(this_cpu_ptr(&n_async_inflight));
+				cur_ops->async(rhp, rcu_scale_async_cb);
+				rhp = NULL;
+			} else if (!kthread_should_stop()) {
+				cur_ops->gp_barrier();
+				goto retry;
+			} else {
+				kfree(rhp); /* Because we are stopping. */
+			}
+		} else if (gp_exp) {
+			cur_ops->exp_sync();
+		} else {
+			cur_ops->sync();
+		}
+		t = ktime_get_mono_fast_ns();
+		*wdp = t - *wdp;
+		i_max = i;
+		if (!started &&
+		    atomic_read(&n_rcu_scale_writer_started) >= nrealwriters)
+			started = true;
+		if (!done && i >= MIN_MEAS) {
+			done = true;
+			sched_set_normal(current, 0);
+			pr_alert("%s%s rcu_scale_writer %ld has %d measurements\n",
+				 scale_type, SCALE_FLAG, me, MIN_MEAS);
+			if (atomic_inc_return(&n_rcu_scale_writer_finished) >=
+			    nrealwriters) {
+				schedule_timeout_interruptible(10);
+				rcu_ftrace_dump(DUMP_ALL);
+				SCALEOUT_STRING("Test complete");
+				t_rcu_scale_writer_finished = t;
+				if (gp_exp) {
+					b_rcu_gp_test_finished =
+						cur_ops->exp_completed() / 2;
+				} else {
+					b_rcu_gp_test_finished =
+						cur_ops->get_gp_seq();
+				}
+				if (shutdown) {
+					smp_mb(); /* Assign before wake. */
+					wake_up(&shutdown_wq);
+				}
+			}
+		}
+		if (done && !alldone &&
+		    atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters)
+			alldone = true;
+		if (started && !alldone && i < MAX_MEAS - 1)
+			i++;
+		rcu_scale_wait_shutdown();
+	} while (!torture_must_stop());
+	if (gp_async) {
+		cur_ops->gp_barrier();
+	}
+	writer_n_durations[me] = i_max;
+	torture_kthread_stopping("rcu_scale_writer");
+	return 0;
+}
+
+static void
+rcu_scale_print_module_parms(struct rcu_scale_ops *cur_ops, const char *tag)
+{
+	pr_alert("%s" SCALE_FLAG
+		 "--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n",
+		 scale_type, tag, nrealreaders, nrealwriters, verbose, shutdown);
+}
+
+static void
+rcu_scale_cleanup(void)
+{
+	int i;
+	int j;
+	int ngps = 0;
+	u64 *wdp;
+	u64 *wdpp;
+
+	/*
+	 * Would like warning at start, but everything is expedited
+	 * during the mid-boot phase, so have to wait till the end.
+	 */
+	if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp)
+		VERBOSE_SCALEOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
+	if (rcu_gp_is_normal() && gp_exp)
+		VERBOSE_SCALEOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
+	if (gp_exp && gp_async)
+		VERBOSE_SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!");
+
+	if (torture_cleanup_begin())
+		return;
+	if (!cur_ops) {
+		torture_cleanup_end();
+		return;
+	}
+
+	if (reader_tasks) {
+		for (i = 0; i < nrealreaders; i++)
+			torture_stop_kthread(rcu_scale_reader,
+					     reader_tasks[i]);
+		kfree(reader_tasks);
+	}
+
+	if (writer_tasks) {
+		for (i = 0; i < nrealwriters; i++) {
+			torture_stop_kthread(rcu_scale_writer,
+					     writer_tasks[i]);
+			if (!writer_n_durations)
+				continue;
+			j = writer_n_durations[i];
+			pr_alert("%s%s writer %d gps: %d\n",
+				 scale_type, SCALE_FLAG, i, j);
+			ngps += j;
+		}
+		pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n",
+			 scale_type, SCALE_FLAG,
+			 t_rcu_scale_writer_started, t_rcu_scale_writer_finished,
+			 t_rcu_scale_writer_finished -
+			 t_rcu_scale_writer_started,
+			 ngps,
+			 rcuscale_seq_diff(b_rcu_gp_test_finished,
+					   b_rcu_gp_test_started));
+		for (i = 0; i < nrealwriters; i++) {
+			if (!writer_durations)
+				break;
+			if (!writer_n_durations)
+				continue;
+			wdpp = writer_durations[i];
+			if (!wdpp)
+				continue;
+			for (j = 0; j <= writer_n_durations[i]; j++) {
+				wdp = &wdpp[j];
+				pr_alert("%s%s %4d writer-duration: %5d %llu\n",
+					scale_type, SCALE_FLAG,
+					i, j, *wdp);
+				if (j % 100 == 0)
+					schedule_timeout_uninterruptible(1);
+			}
+			kfree(writer_durations[i]);
+		}
+		kfree(writer_tasks);
+		kfree(writer_durations);
+		kfree(writer_n_durations);
+	}
+
+	/* Do torture-type-specific cleanup operations.  */
+	if (cur_ops->cleanup != NULL)
+		cur_ops->cleanup();
+
+	torture_cleanup_end();
+}
+
+/*
+ * Return the number if non-negative.  If -1, the number of CPUs.
+ * If less than -1, that much less than the number of CPUs, but
+ * at least one.
+ */
+static int compute_real(int n)
+{
+	int nr;
+
+	if (n >= 0) {
+		nr = n;
+	} else {
+		nr = num_online_cpus() + 1 + n;
+		if (nr <= 0)
+			nr = 1;
+	}
+	return nr;
+}
+
+/*
+ * RCU scalability shutdown kthread.  Just waits to be awakened, then shuts
+ * down system.
+ */
+static int
+rcu_scale_shutdown(void *arg)
+{
+	wait_event(shutdown_wq,
+		   atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters);
+	smp_mb(); /* Wake before output. */
+	rcu_scale_cleanup();
+	kernel_power_off();
+	return -EINVAL;
+}
+
+/*
+ * kfree_rcu() scalability tests: Start a kfree_rcu() loop on all CPUs for number
+ * of iterations and measure total time and number of GP for all iterations to complete.
+ */
+
+torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu().");
+torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration.");
+torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees.");
+
+static struct task_struct **kfree_reader_tasks;
+static int kfree_nrealthreads;
+static atomic_t n_kfree_scale_thread_started;
+static atomic_t n_kfree_scale_thread_ended;
+
+struct kfree_obj {
+	char kfree_obj[8];
+	struct rcu_head rh;
+};
+
+static int
+kfree_scale_thread(void *arg)
+{
+	int i, loop = 0;
+	long me = (long)arg;
+	struct kfree_obj *alloc_ptr;
+	u64 start_time, end_time;
+	long long mem_begin, mem_during = 0;
+
+	VERBOSE_SCALEOUT_STRING("kfree_scale_thread task started");
+	set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
+	set_user_nice(current, MAX_NICE);
+
+	start_time = ktime_get_mono_fast_ns();
+
+	if (atomic_inc_return(&n_kfree_scale_thread_started) >= kfree_nrealthreads) {
+		if (gp_exp)
+			b_rcu_gp_test_started = cur_ops->exp_completed() / 2;
+		else
+			b_rcu_gp_test_started = cur_ops->get_gp_seq();
+	}
+
+	do {
+		if (!mem_during) {
+			mem_during = mem_begin = si_mem_available();
+		} else if (loop % (kfree_loops / 4) == 0) {
+			mem_during = (mem_during + si_mem_available()) / 2;
+		}
+
+		for (i = 0; i < kfree_alloc_num; i++) {
+			alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
+			if (!alloc_ptr)
+				return -ENOMEM;
+
+			kfree_rcu(alloc_ptr, rh);
+		}
+
+		cond_resched();
+	} while (!torture_must_stop() && ++loop < kfree_loops);
+
+	if (atomic_inc_return(&n_kfree_scale_thread_ended) >= kfree_nrealthreads) {
+		end_time = ktime_get_mono_fast_ns();
+
+		if (gp_exp)
+			b_rcu_gp_test_finished = cur_ops->exp_completed() / 2;
+		else
+			b_rcu_gp_test_finished = cur_ops->get_gp_seq();
+
+		pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n",
+		       (unsigned long long)(end_time - start_time), kfree_loops,
+		       rcuscale_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started),
+		       (mem_begin - mem_during) >> (20 - PAGE_SHIFT));
+
+		if (shutdown) {
+			smp_mb(); /* Assign before wake. */
+			wake_up(&shutdown_wq);
+		}
+	}
+
+	torture_kthread_stopping("kfree_scale_thread");
+	return 0;
+}
+
+static void
+kfree_scale_cleanup(void)
+{
+	int i;
+
+	if (torture_cleanup_begin())
+		return;
+
+	if (kfree_reader_tasks) {
+		for (i = 0; i < kfree_nrealthreads; i++)
+			torture_stop_kthread(kfree_scale_thread,
+					     kfree_reader_tasks[i]);
+		kfree(kfree_reader_tasks);
+	}
+
+	torture_cleanup_end();
+}
+
+/*
+ * shutdown kthread.  Just waits to be awakened, then shuts down system.
+ */
+static int
+kfree_scale_shutdown(void *arg)
+{
+	wait_event(shutdown_wq,
+		   atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads);
+
+	smp_mb(); /* Wake before output. */
+
+	kfree_scale_cleanup();
+	kernel_power_off();
+	return -EINVAL;
+}
+
+static int __init
+kfree_scale_init(void)
+{
+	long i;
+	int firsterr = 0;
+
+	kfree_nrealthreads = compute_real(kfree_nthreads);
+	/* Start up the kthreads. */
+	if (shutdown) {
+		init_waitqueue_head(&shutdown_wq);
+		firsterr = torture_create_kthread(kfree_scale_shutdown, NULL,
+						  shutdown_task);
+		if (firsterr)
+			goto unwind;
+		schedule_timeout_uninterruptible(1);
+	}
+
+	pr_alert("kfree object size=%zu\n", kfree_mult * sizeof(struct kfree_obj));
+
+	kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]),
+			       GFP_KERNEL);
+	if (kfree_reader_tasks == NULL) {
+		firsterr = -ENOMEM;
+		goto unwind;
+	}
+
+	for (i = 0; i < kfree_nrealthreads; i++) {
+		firsterr = torture_create_kthread(kfree_scale_thread, (void *)i,
+						  kfree_reader_tasks[i]);
+		if (firsterr)
+			goto unwind;
+	}
+
+	while (atomic_read(&n_kfree_scale_thread_started) < kfree_nrealthreads)
+		schedule_timeout_uninterruptible(1);
+
+	torture_init_end();
+	return 0;
+
+unwind:
+	torture_init_end();
+	kfree_scale_cleanup();
+	return firsterr;
+}
+
+static int __init
+rcu_scale_init(void)
+{
+	long i;
+	int firsterr = 0;
+	static struct rcu_scale_ops *scale_ops[] = {
+		&rcu_ops, &srcu_ops, &srcud_ops, &tasks_ops,
+	};
+
+	if (!torture_init_begin(scale_type, verbose))
+		return -EBUSY;
+
+	/* Process args and announce that the scalability'er is on the job. */
+	for (i = 0; i < ARRAY_SIZE(scale_ops); i++) {
+		cur_ops = scale_ops[i];
+		if (strcmp(scale_type, cur_ops->name) == 0)
+			break;
+	}
+	if (i == ARRAY_SIZE(scale_ops)) {
+		pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type);
+		pr_alert("rcu-scale types:");
+		for (i = 0; i < ARRAY_SIZE(scale_ops); i++)
+			pr_cont(" %s", scale_ops[i]->name);
+		pr_cont("\n");
+		WARN_ON(!IS_MODULE(CONFIG_RCU_SCALE_TEST));
+		firsterr = -EINVAL;
+		cur_ops = NULL;
+		goto unwind;
+	}
+	if (cur_ops->init)
+		cur_ops->init();
+
+	if (kfree_rcu_test)
+		return kfree_scale_init();
+
+	nrealwriters = compute_real(nwriters);
+	nrealreaders = compute_real(nreaders);
+	atomic_set(&n_rcu_scale_reader_started, 0);
+	atomic_set(&n_rcu_scale_writer_started, 0);
+	atomic_set(&n_rcu_scale_writer_finished, 0);
+	rcu_scale_print_module_parms(cur_ops, "Start of test");
+
+	/* Start up the kthreads. */
+
+	if (shutdown) {
+		init_waitqueue_head(&shutdown_wq);
+		firsterr = torture_create_kthread(rcu_scale_shutdown, NULL,
+						  shutdown_task);
+		if (firsterr)
+			goto unwind;
+		schedule_timeout_uninterruptible(1);
+	}
+	reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
+			       GFP_KERNEL);
+	if (reader_tasks == NULL) {
+		VERBOSE_SCALEOUT_ERRSTRING("out of memory");
+		firsterr = -ENOMEM;
+		goto unwind;
+	}
+	for (i = 0; i < nrealreaders; i++) {
+		firsterr = torture_create_kthread(rcu_scale_reader, (void *)i,
+						  reader_tasks[i]);
+		if (firsterr)
+			goto unwind;
+	}
+	while (atomic_read(&n_rcu_scale_reader_started) < nrealreaders)
+		schedule_timeout_uninterruptible(1);
+	writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]),
+			       GFP_KERNEL);
+	writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations),
+				   GFP_KERNEL);
+	writer_n_durations =
+		kcalloc(nrealwriters, sizeof(*writer_n_durations),
+			GFP_KERNEL);
+	if (!writer_tasks || !writer_durations || !writer_n_durations) {
+		VERBOSE_SCALEOUT_ERRSTRING("out of memory");
+		firsterr = -ENOMEM;
+		goto unwind;
+	}
+	for (i = 0; i < nrealwriters; i++) {
+		writer_durations[i] =
+			kcalloc(MAX_MEAS, sizeof(*writer_durations[i]),
+				GFP_KERNEL);
+		if (!writer_durations[i]) {
+			firsterr = -ENOMEM;
+			goto unwind;
+		}
+		firsterr = torture_create_kthread(rcu_scale_writer, (void *)i,
+						  writer_tasks[i]);
+		if (firsterr)
+			goto unwind;
+	}
+	torture_init_end();
+	return 0;
+
+unwind:
+	torture_init_end();
+	rcu_scale_cleanup();
+	return firsterr;
+}
+
+module_init(rcu_scale_init);
+module_exit(rcu_scale_cleanup);
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 3c9feca..6c1aea4 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -7,7 +7,7 @@
  * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
  *	  Josh Triplett <josh@joshtriplett.org>
  *
- * See also:  Documentation/RCU/torture.txt
+ * See also:  Documentation/RCU/torture.rst
  */
 
 #define pr_fmt(fmt) fmt
@@ -20,7 +20,7 @@
 #include <linux/err.h>
 #include <linux/spinlock.h>
 #include <linux/smp.h>
-#include <linux/rcupdate.h>
+#include <linux/rcupdate_wait.h>
 #include <linux/interrupt.h>
 #include <linux/sched/signal.h>
 #include <uapi/linux/sched/types.h>
@@ -44,13 +44,14 @@
 #include <linux/sched/debug.h>
 #include <linux/sched/sysctl.h>
 #include <linux/oom.h>
+#include <linux/tick.h>
+#include <linux/rcupdate_trace.h>
 
 #include "rcu.h"
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
 
-
 /* Bits for ->extendables field, extendables param, and related definitions. */
 #define RCUTORTURE_RDR_SHIFT	 8	/* Put SRCU index in upper bits. */
 #define RCUTORTURE_RDR_MASK	 ((1 << RCUTORTURE_RDR_SHIFT) - 1)
@@ -86,6 +87,7 @@
 	     "Use normal (non-expedited) GP wait primitives");
 torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives");
 torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
+torture_param(int, leakpointer, 0, "Leak pointer dereferences from readers");
 torture_param(int, n_barrier_cbs, 0,
 	     "# of callbacks/kthreads for barrier testing");
 torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
@@ -95,12 +97,19 @@
 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
 torture_param(int, onoff_interval, 0,
 	     "Time between CPU hotplugs (jiffies), 0=disable");
+torture_param(int, read_exit_delay, 13,
+	      "Delay between read-then-exit episodes (s)");
+torture_param(int, read_exit_burst, 16,
+	      "# of read-then-exit bursts per episode, zero to disable");
 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
 torture_param(int, stall_cpu_holdoff, 10,
 	     "Time to wait before starting stall (s).");
 torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling.");
+torture_param(int, stall_cpu_block, 0, "Sleep while stalling.");
+torture_param(int, stall_gp_kthread, 0,
+	      "Grace-period kthread stall duration (s).");
 torture_param(int, stat_interval, 60,
 	     "Number of seconds between stats printk()s");
 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
@@ -129,6 +138,7 @@
 static struct task_struct *fwd_prog_task;
 static struct task_struct **barrier_cbs_tasks;
 static struct task_struct *barrier_task;
+static struct task_struct *read_exit_task;
 
 #define RCU_TORTURE_PIPE_LEN 10
 
@@ -160,8 +170,10 @@
 static atomic_long_t n_rcu_torture_timers;
 static long n_barrier_attempts;
 static long n_barrier_successes; /* did rcu_barrier test succeed? */
+static unsigned long n_read_exits;
 static struct list_head rcu_torture_removed;
 static unsigned long shutdown_jiffies;
+static unsigned long start_gp_seq;
 
 static int rcu_torture_writer_state;
 #define RTWS_FIXED_DELAY	0
@@ -338,7 +350,7 @@
 	 * period, and we want a long delay occasionally to trigger
 	 * force_quiescent_state. */
 
-	if (!rcu_fwd_cb_nodelay &&
+	if (!READ_ONCE(rcu_fwd_cb_nodelay) &&
 	    !(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
 		started = cur_ops->get_gp_seq();
 		ts = rcu_trace_clock_local();
@@ -374,11 +386,12 @@
 {
 	int i;
 
-	i = rp->rtort_pipe_count;
+	i = READ_ONCE(rp->rtort_pipe_count);
 	if (i > RCU_TORTURE_PIPE_LEN)
 		i = RCU_TORTURE_PIPE_LEN;
 	atomic_inc(&rcu_torture_wcount[i]);
-	if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
+	WRITE_ONCE(rp->rtort_pipe_count, i + 1);
+	if (rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
 		rp->rtort_mbtest = 0;
 		return true;
 	}
@@ -663,6 +676,11 @@
 	call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
 }
 
+static void synchronize_rcu_mult_test(void)
+{
+	synchronize_rcu_mult(call_rcu_tasks, call_rcu);
+}
+
 static struct rcu_torture_ops tasks_ops = {
 	.ttype		= RCU_TASKS_FLAVOR,
 	.init		= rcu_sync_torture_init,
@@ -672,7 +690,7 @@
 	.get_gp_seq	= rcu_no_completed,
 	.deferred_free	= rcu_tasks_torture_deferred_free,
 	.sync		= synchronize_rcu_tasks,
-	.exp_sync	= synchronize_rcu_tasks,
+	.exp_sync	= synchronize_rcu_mult_test,
 	.call		= call_rcu_tasks,
 	.cb_barrier	= rcu_barrier_tasks,
 	.fqs		= NULL,
@@ -723,6 +741,72 @@
 	.name		= "trivial"
 };
 
+/*
+ * Definitions for rude RCU-tasks torture testing.
+ */
+
+static void rcu_tasks_rude_torture_deferred_free(struct rcu_torture *p)
+{
+	call_rcu_tasks_rude(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops tasks_rude_ops = {
+	.ttype		= RCU_TASKS_RUDE_FLAVOR,
+	.init		= rcu_sync_torture_init,
+	.readlock	= rcu_torture_read_lock_trivial,
+	.read_delay	= rcu_read_delay,  /* just reuse rcu's version. */
+	.readunlock	= rcu_torture_read_unlock_trivial,
+	.get_gp_seq	= rcu_no_completed,
+	.deferred_free	= rcu_tasks_rude_torture_deferred_free,
+	.sync		= synchronize_rcu_tasks_rude,
+	.exp_sync	= synchronize_rcu_tasks_rude,
+	.call		= call_rcu_tasks_rude,
+	.cb_barrier	= rcu_barrier_tasks_rude,
+	.fqs		= NULL,
+	.stats		= NULL,
+	.irq_capable	= 1,
+	.name		= "tasks-rude"
+};
+
+/*
+ * Definitions for tracing RCU-tasks torture testing.
+ */
+
+static int tasks_tracing_torture_read_lock(void)
+{
+	rcu_read_lock_trace();
+	return 0;
+}
+
+static void tasks_tracing_torture_read_unlock(int idx)
+{
+	rcu_read_unlock_trace();
+}
+
+static void rcu_tasks_tracing_torture_deferred_free(struct rcu_torture *p)
+{
+	call_rcu_tasks_trace(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops tasks_tracing_ops = {
+	.ttype		= RCU_TASKS_TRACING_FLAVOR,
+	.init		= rcu_sync_torture_init,
+	.readlock	= tasks_tracing_torture_read_lock,
+	.read_delay	= srcu_read_delay,  /* just reuse srcu's version. */
+	.readunlock	= tasks_tracing_torture_read_unlock,
+	.get_gp_seq	= rcu_no_completed,
+	.deferred_free	= rcu_tasks_tracing_torture_deferred_free,
+	.sync		= synchronize_rcu_tasks_trace,
+	.exp_sync	= synchronize_rcu_tasks_trace,
+	.call		= call_rcu_tasks_trace,
+	.cb_barrier	= rcu_barrier_tasks_trace,
+	.fqs		= NULL,
+	.stats		= NULL,
+	.irq_capable	= 1,
+	.slow_gps	= 1,
+	.name		= "tasks-tracing"
+};
+
 static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
 {
 	if (!cur_ops->gp_diff)
@@ -732,7 +816,7 @@
 
 static bool __maybe_unused torturing_tasks(void)
 {
-	return cur_ops == &tasks_ops;
+	return cur_ops == &tasks_ops || cur_ops == &tasks_rude_ops;
 }
 
 /*
@@ -800,16 +884,11 @@
 	unsigned long endtime;
 	unsigned long oldstarttime;
 	struct rcu_boost_inflight rbi = { .inflight = 0 };
-	struct sched_param sp;
 
 	VERBOSE_TOROUT_STRING("rcu_torture_boost started");
 
 	/* Set real-time priority. */
-	sp.sched_priority = 1;
-	if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
-		VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
-		n_rcu_torture_boost_rterror++;
-	}
+	sched_set_fifo_low(current);
 
 	init_rcu_head_on_stack(&rbi.rcu);
 	/* Each pass through the following loop does one boost-test cycle. */
@@ -831,7 +910,7 @@
 
 		/* Wait for the next test interval. */
 		oldstarttime = boost_starttime;
-		while (ULONG_CMP_LT(jiffies, oldstarttime)) {
+		while (time_before(jiffies, oldstarttime)) {
 			schedule_timeout_interruptible(oldstarttime - jiffies);
 			stutter_wait("rcu_torture_boost");
 			if (torture_must_stop())
@@ -841,7 +920,7 @@
 		/* Do one boost-test interval. */
 		endtime = oldstarttime + test_boost_duration * HZ;
 		call_rcu_time = jiffies;
-		while (ULONG_CMP_LT(jiffies, endtime)) {
+		while (time_before(jiffies, endtime)) {
 			/* If we don't have a callback in flight, post one. */
 			if (!smp_load_acquire(&rbi.inflight)) {
 				/* RCU core before ->inflight = 1. */
@@ -912,7 +991,7 @@
 	VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
 	do {
 		fqs_resume_time = jiffies + fqs_stutter * HZ;
-		while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
+		while (time_before(jiffies, fqs_resume_time) &&
 		       !kthread_should_stop()) {
 			schedule_timeout_interruptible(1);
 		}
@@ -1014,7 +1093,8 @@
 			if (i > RCU_TORTURE_PIPE_LEN)
 				i = RCU_TORTURE_PIPE_LEN;
 			atomic_inc(&rcu_torture_wcount[i]);
-			old_rp->rtort_pipe_count++;
+			WRITE_ONCE(old_rp->rtort_pipe_count,
+				   old_rp->rtort_pipe_count + 1);
 			switch (synctype[torture_random(&rand) % nsynctypes]) {
 			case RTWS_DEF_FREE:
 				rcu_torture_writer_state = RTWS_DEF_FREE;
@@ -1066,7 +1146,8 @@
 		if (stutter_wait("rcu_torture_writer") &&
 		    !READ_ONCE(rcu_fwd_cb_nodelay) &&
 		    !cur_ops->slow_gps &&
-		    !torture_must_stop())
+		    !torture_must_stop() &&
+		    rcu_inkernel_boot_has_ended())
 			for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)
 				if (list_empty(&rcu_tortures[i].rtort_free) &&
 				    rcu_access_pointer(rcu_torture_current) !=
@@ -1075,6 +1156,7 @@
 					WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
 				}
 	} while (!torture_must_stop());
+	rcu_torture_current = NULL;  // Let stats task know that we are done.
 	/* Reset expediting back to unexpedited. */
 	if (expediting > 0)
 		expediting = -expediting;
@@ -1143,6 +1225,7 @@
 				  struct torture_random_state *trsp,
 				  struct rt_read_seg *rtrsp)
 {
+	unsigned long flags;
 	int idxnew = -1;
 	int idxold = *readstate;
 	int statesnew = ~*readstate & newstate;
@@ -1155,30 +1238,43 @@
 	/* First, put new protection in place to avoid critical-section gap. */
 	if (statesnew & RCUTORTURE_RDR_BH)
 		local_bh_disable();
+	if (statesnew & RCUTORTURE_RDR_RBH)
+		rcu_read_lock_bh();
 	if (statesnew & RCUTORTURE_RDR_IRQ)
 		local_irq_disable();
 	if (statesnew & RCUTORTURE_RDR_PREEMPT)
 		preempt_disable();
-	if (statesnew & RCUTORTURE_RDR_RBH)
-		rcu_read_lock_bh();
 	if (statesnew & RCUTORTURE_RDR_SCHED)
 		rcu_read_lock_sched();
 	if (statesnew & RCUTORTURE_RDR_RCU)
 		idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT;
 
-	/* Next, remove old protection, irq first due to bh conflict. */
+	/*
+	 * Next, remove old protection, in decreasing order of strength
+	 * to avoid unlock paths that aren't safe in the stronger
+	 * context. Namely: BH can not be enabled with disabled interrupts.
+	 * Additionally PREEMPT_RT requires that BH is enabled in preemptible
+	 * context.
+	 */
 	if (statesold & RCUTORTURE_RDR_IRQ)
 		local_irq_enable();
-	if (statesold & RCUTORTURE_RDR_BH)
-		local_bh_enable();
 	if (statesold & RCUTORTURE_RDR_PREEMPT)
 		preempt_enable();
-	if (statesold & RCUTORTURE_RDR_RBH)
-		rcu_read_unlock_bh();
 	if (statesold & RCUTORTURE_RDR_SCHED)
 		rcu_read_unlock_sched();
-	if (statesold & RCUTORTURE_RDR_RCU)
+	if (statesold & RCUTORTURE_RDR_BH)
+		local_bh_enable();
+	if (statesold & RCUTORTURE_RDR_RBH)
+		rcu_read_unlock_bh();
+	if (statesold & RCUTORTURE_RDR_RCU) {
+		bool lockit = !statesnew && !(torture_random(trsp) & 0xffff);
+
+		if (lockit)
+			raw_spin_lock_irqsave(&current->pi_lock, flags);
 		cur_ops->readunlock(idxold >> RCUTORTURE_RDR_SHIFT);
+		if (lockit)
+			raw_spin_unlock_irqrestore(&current->pi_lock, flags);
+	}
 
 	/* Delay if neither beginning nor end and there was a change. */
 	if ((statesnew || statesold) && *readstate && newstate)
@@ -1212,6 +1308,9 @@
 	int mask = rcutorture_extend_mask_max();
 	unsigned long randmask1 = torture_random(trsp) >> 8;
 	unsigned long randmask2 = randmask1 >> 3;
+	unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED;
+	unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ;
+	unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
 
 	WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT);
 	/* Mostly only one bit (need preemption!), sometimes lots of bits. */
@@ -1219,11 +1318,26 @@
 		mask = mask & randmask2;
 	else
 		mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS));
-	/* Can't enable bh w/irq disabled. */
-	if ((mask & RCUTORTURE_RDR_IRQ) &&
-	    ((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) ||
-	     (!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH))))
-		mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
+
+	/*
+	 * Can't enable bh w/irq disabled.
+	 */
+	if (mask & RCUTORTURE_RDR_IRQ)
+		mask |= oldmask & bhs;
+
+	/*
+	 * Ideally these sequences would be detected in debug builds
+	 * (regardless of RT), but until then don't stop testing
+	 * them on non-RT.
+	 */
+	if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		/* Can't modify BH in atomic context */
+		if (oldmask & preempts_irq)
+			mask &= ~bhs;
+		if ((oldmask | mask) & preempts_irq)
+			mask |= oldmask & bhs;
+	}
+
 	return mask ?: RCUTORTURE_RDR_RCU;
 }
 
@@ -1271,6 +1385,7 @@
 	struct rt_read_seg *rtrsp1;
 	unsigned long long ts;
 
+	WARN_ON_ONCE(!rcu_is_watching());
 	newstate = rcutorture_extend_mask(readstate, trsp);
 	rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++);
 	started = cur_ops->get_gp_seq();
@@ -1279,6 +1394,7 @@
 				  rcu_read_lock_bh_held() ||
 				  rcu_read_lock_sched_held() ||
 				  srcu_read_lock_held(srcu_ctlp) ||
+				  rcu_read_lock_trace_held() ||
 				  torturing_tasks());
 	if (p == NULL) {
 		/* Wait for rcu_torture_writer to get underway */
@@ -1289,7 +1405,7 @@
 		atomic_inc(&n_rcu_torture_mberror);
 	rtrsp = rcutorture_loop_extend(&readstate, trsp, rtrsp);
 	preempt_disable();
-	pipe_count = p->rtort_pipe_count;
+	pipe_count = READ_ONCE(p->rtort_pipe_count);
 	if (pipe_count > RCU_TORTURE_PIPE_LEN) {
 		/* Should not happen, but... */
 		pipe_count = RCU_TORTURE_PIPE_LEN;
@@ -1310,6 +1426,9 @@
 	preempt_enable();
 	rcutorture_one_extend(&readstate, 0, trsp, rtrsp);
 	WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK);
+	// This next splat is expected behavior if leakpointer, especially
+	// for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels.
+	WARN_ON_ONCE(leakpointer && READ_ONCE(p->rtort_pipe_count) > 1);
 
 	/* If error or close call, record the sequence of reader protections. */
 	if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) {
@@ -1363,15 +1482,15 @@
 	set_user_nice(current, MAX_NICE);
 	if (irqreader && cur_ops->irq_capable)
 		timer_setup_on_stack(&t, rcu_torture_timer, 0);
-
+	tick_dep_set_task(current, TICK_DEP_BIT_RCU);
 	do {
 		if (irqreader && cur_ops->irq_capable) {
 			if (!timer_pending(&t))
 				mod_timer(&t, jiffies + 1);
 		}
-		if (!rcu_torture_one_read(&rand))
+		if (!rcu_torture_one_read(&rand) && !torture_must_stop())
 			schedule_timeout_interruptible(HZ);
-		if (time_after(jiffies, lastsleep)) {
+		if (time_after(jiffies, lastsleep) && !torture_must_stop()) {
 			schedule_timeout_interruptible(1);
 			lastsleep = jiffies + 10;
 		}
@@ -1383,6 +1502,7 @@
 		del_timer_sync(&t);
 		destroy_timer_on_stack(&t);
 	}
+	tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
 	torture_kthread_stopping("rcu_torture_reader");
 	return 0;
 }
@@ -1402,14 +1522,15 @@
 	int i;
 	long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
 	long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
+	struct rcu_torture *rtcp;
 	static unsigned long rtcv_snap = ULONG_MAX;
 	static bool splatted;
 	struct task_struct *wtp;
 
 	for_each_possible_cpu(cpu) {
 		for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
-			pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
-			batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
+			pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]);
+			batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]);
 		}
 	}
 	for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
@@ -1418,9 +1539,10 @@
 	}
 
 	pr_alert("%s%s ", torture_type, TORTURE_FLAG);
+	rtcp = rcu_access_pointer(rcu_torture_current);
 	pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
-		rcu_torture_current,
-		rcu_torture_current ? "ver" : "VER",
+		rtcp,
+		rtcp && !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER",
 		rcu_torture_current_version,
 		list_empty(&rcu_torture_freelist),
 		atomic_read(&n_rcu_torture_alloc),
@@ -1436,21 +1558,25 @@
 		n_rcu_torture_boosts,
 		atomic_long_read(&n_rcu_torture_timers));
 	torture_onoff_stats();
-	pr_cont("barrier: %ld/%ld:%ld\n",
-		n_barrier_successes,
-		n_barrier_attempts,
-		n_rcu_torture_barrier_error);
+	pr_cont("barrier: %ld/%ld:%ld ",
+		data_race(n_barrier_successes),
+		data_race(n_barrier_attempts),
+		data_race(n_rcu_torture_barrier_error));
+	pr_cont("read-exits: %ld\n", data_race(n_read_exits));
 
 	pr_alert("%s%s ", torture_type, TORTURE_FLAG);
-	if (atomic_read(&n_rcu_torture_mberror) != 0 ||
-	    n_rcu_torture_barrier_error != 0 ||
-	    n_rcu_torture_boost_ktrerror != 0 ||
-	    n_rcu_torture_boost_rterror != 0 ||
-	    n_rcu_torture_boost_failure != 0 ||
+	if (atomic_read(&n_rcu_torture_mberror) ||
+	    n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror ||
+	    n_rcu_torture_boost_rterror || n_rcu_torture_boost_failure ||
 	    i > 1) {
 		pr_cont("%s", "!!! ");
 		atomic_inc(&n_rcu_torture_error);
-		WARN_ON_ONCE(1);
+		WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror));
+		WARN_ON_ONCE(n_rcu_torture_barrier_error);  // rcu_barrier()
+		WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread
+		WARN_ON_ONCE(n_rcu_torture_boost_rterror); // can't set RT prio
+		WARN_ON_ONCE(n_rcu_torture_boost_failure); // RCU boost failed
+		WARN_ON_ONCE(i > 1); // Too-short grace period
 	}
 	pr_cont("Reader Pipe: ");
 	for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
@@ -1473,7 +1599,8 @@
 	if (cur_ops->stats)
 		cur_ops->stats();
 	if (rtcv_snap == rcu_torture_current_version &&
-	    rcu_torture_current != NULL) {
+	    rcu_access_pointer(rcu_torture_current) &&
+	    !rcu_stall_is_suppressed()) {
 		int __maybe_unused flags = 0;
 		unsigned long __maybe_unused gp_seq = 0;
 
@@ -1525,16 +1652,20 @@
 		 "test_boost=%d/%d test_boost_interval=%d "
 		 "test_boost_duration=%d shutdown_secs=%d "
 		 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
+		 "stall_cpu_block=%d "
 		 "n_barrier_cbs=%d "
-		 "onoff_interval=%d onoff_holdoff=%d\n",
+		 "onoff_interval=%d onoff_holdoff=%d "
+		 "read_exit_delay=%d read_exit_burst=%d\n",
 		 torture_type, tag, nrealreaders, nfakewriters,
 		 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
 		 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
 		 test_boost, cur_ops->can_boost,
 		 test_boost_interval, test_boost_duration, shutdown_secs,
 		 stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff,
+		 stall_cpu_block,
 		 n_barrier_cbs,
-		 onoff_interval, onoff_holdoff);
+		 onoff_interval, onoff_holdoff,
+		 read_exit_delay, read_exit_burst);
 }
 
 static int rcutorture_booster_cleanup(unsigned int cpu)
@@ -1588,6 +1719,7 @@
  */
 static int rcu_torture_stall(void *args)
 {
+	int idx;
 	unsigned long stop_at;
 
 	VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
@@ -1596,26 +1728,37 @@
 		schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
 		VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
 	}
-	if (!kthread_should_stop()) {
+	if (!kthread_should_stop() && stall_gp_kthread > 0) {
+		VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall");
+		rcu_gp_set_torture_wait(stall_gp_kthread * HZ);
+		for (idx = 0; idx < stall_gp_kthread + 2; idx++) {
+			if (kthread_should_stop())
+				break;
+			schedule_timeout_uninterruptible(HZ);
+		}
+	}
+	if (!kthread_should_stop() && stall_cpu > 0) {
+		VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall");
 		stop_at = ktime_get_seconds() + stall_cpu;
 		/* RCU CPU stall is expected behavior in following code. */
-		rcu_read_lock();
+		idx = cur_ops->readlock();
 		if (stall_cpu_irqsoff)
 			local_irq_disable();
-		else
+		else if (!stall_cpu_block)
 			preempt_disable();
 		pr_alert("rcu_torture_stall start on CPU %d.\n",
-			 smp_processor_id());
+			 raw_smp_processor_id());
 		while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
 				    stop_at))
-			continue;  /* Induce RCU CPU stall warning. */
+			if (stall_cpu_block)
+				schedule_timeout_uninterruptible(HZ);
 		if (stall_cpu_irqsoff)
 			local_irq_enable();
-		else
+		else if (!stall_cpu_block)
 			preempt_enable();
-		rcu_read_unlock();
-		pr_alert("rcu_torture_stall end.\n");
+		cur_ops->readunlock(idx);
 	}
+	pr_alert("rcu_torture_stall end.\n");
 	torture_shutdown_absorb("rcu_torture_stall");
 	while (!kthread_should_stop())
 		schedule_timeout_interruptible(10 * HZ);
@@ -1625,7 +1768,7 @@
 /* Spawn CPU-stall kthread, if stall_cpu specified. */
 static int __init rcu_torture_stall_init(void)
 {
-	if (stall_cpu <= 0)
+	if (stall_cpu <= 0 && stall_gp_kthread <= 0)
 		return 0;
 	return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
 }
@@ -1656,43 +1799,53 @@
 struct rcu_fwd_cb {
 	struct rcu_head rh;
 	struct rcu_fwd_cb *rfc_next;
+	struct rcu_fwd *rfc_rfp;
 	int rfc_gps;
 };
-static DEFINE_SPINLOCK(rcu_fwd_lock);
-static struct rcu_fwd_cb *rcu_fwd_cb_head;
-static struct rcu_fwd_cb **rcu_fwd_cb_tail = &rcu_fwd_cb_head;
-static long n_launders_cb;
-static unsigned long rcu_fwd_startat;
-static bool rcu_fwd_emergency_stop;
+
 #define MAX_FWD_CB_JIFFIES	(8 * HZ) /* Maximum CB test duration. */
 #define MIN_FWD_CB_LAUNDERS	3	/* This many CB invocations to count. */
 #define MIN_FWD_CBS_LAUNDERED	100	/* Number of counted CBs. */
 #define FWD_CBS_HIST_DIV	10	/* Histogram buckets/second. */
+#define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV))
+
 struct rcu_launder_hist {
 	long n_launders;
 	unsigned long launder_gp_seq;
 };
-#define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV))
-static struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST];
-static unsigned long rcu_launder_gp_seq_start;
 
-static void rcu_torture_fwd_cb_hist(void)
+struct rcu_fwd {
+	spinlock_t rcu_fwd_lock;
+	struct rcu_fwd_cb *rcu_fwd_cb_head;
+	struct rcu_fwd_cb **rcu_fwd_cb_tail;
+	long n_launders_cb;
+	unsigned long rcu_fwd_startat;
+	struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST];
+	unsigned long rcu_launder_gp_seq_start;
+};
+
+static DEFINE_MUTEX(rcu_fwd_mutex);
+static struct rcu_fwd *rcu_fwds;
+static bool rcu_fwd_emergency_stop;
+
+static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
 {
 	unsigned long gps;
 	unsigned long gps_old;
 	int i;
 	int j;
 
-	for (i = ARRAY_SIZE(n_launders_hist) - 1; i > 0; i--)
-		if (n_launders_hist[i].n_launders > 0)
+	for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--)
+		if (rfp->n_launders_hist[i].n_launders > 0)
 			break;
 	pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):",
-		 __func__, jiffies - rcu_fwd_startat);
-	gps_old = rcu_launder_gp_seq_start;
+		 __func__, jiffies - rfp->rcu_fwd_startat);
+	gps_old = rfp->rcu_launder_gp_seq_start;
 	for (j = 0; j <= i; j++) {
-		gps = n_launders_hist[j].launder_gp_seq;
+		gps = rfp->n_launders_hist[j].launder_gp_seq;
 		pr_cont(" %ds/%d: %ld:%ld",
-			j + 1, FWD_CBS_HIST_DIV, n_launders_hist[j].n_launders,
+			j + 1, FWD_CBS_HIST_DIV,
+			rfp->n_launders_hist[j].n_launders,
 			rcutorture_seq_diff(gps, gps_old));
 		gps_old = gps;
 	}
@@ -1706,65 +1859,72 @@
 	int i;
 	struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh);
 	struct rcu_fwd_cb **rfcpp;
+	struct rcu_fwd *rfp = rfcp->rfc_rfp;
 
 	rfcp->rfc_next = NULL;
 	rfcp->rfc_gps++;
-	spin_lock_irqsave(&rcu_fwd_lock, flags);
-	rfcpp = rcu_fwd_cb_tail;
-	rcu_fwd_cb_tail = &rfcp->rfc_next;
+	spin_lock_irqsave(&rfp->rcu_fwd_lock, flags);
+	rfcpp = rfp->rcu_fwd_cb_tail;
+	rfp->rcu_fwd_cb_tail = &rfcp->rfc_next;
 	WRITE_ONCE(*rfcpp, rfcp);
-	WRITE_ONCE(n_launders_cb, n_launders_cb + 1);
-	i = ((jiffies - rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV));
-	if (i >= ARRAY_SIZE(n_launders_hist))
-		i = ARRAY_SIZE(n_launders_hist) - 1;
-	n_launders_hist[i].n_launders++;
-	n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq();
-	spin_unlock_irqrestore(&rcu_fwd_lock, flags);
+	WRITE_ONCE(rfp->n_launders_cb, rfp->n_launders_cb + 1);
+	i = ((jiffies - rfp->rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV));
+	if (i >= ARRAY_SIZE(rfp->n_launders_hist))
+		i = ARRAY_SIZE(rfp->n_launders_hist) - 1;
+	rfp->n_launders_hist[i].n_launders++;
+	rfp->n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq();
+	spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags);
 }
 
 // Give the scheduler a chance, even on nohz_full CPUs.
 static void rcu_torture_fwd_prog_cond_resched(unsigned long iter)
 {
-	if (IS_ENABLED(CONFIG_PREEMPT) && IS_ENABLED(CONFIG_NO_HZ_FULL)) {
+	if (IS_ENABLED(CONFIG_PREEMPTION) && IS_ENABLED(CONFIG_NO_HZ_FULL)) {
 		// Real call_rcu() floods hit userspace, so emulate that.
 		if (need_resched() || (iter & 0xfff))
 			schedule();
-	} else {
-		// No userspace emulation: CB invocation throttles call_rcu()
-		cond_resched();
+		return;
 	}
+	// No userspace emulation: CB invocation throttles call_rcu()
+	cond_resched();
 }
 
 /*
  * Free all callbacks on the rcu_fwd_cb_head list, either because the
  * test is over or because we hit an OOM event.
  */
-static unsigned long rcu_torture_fwd_prog_cbfree(void)
+static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd *rfp)
 {
 	unsigned long flags;
 	unsigned long freed = 0;
 	struct rcu_fwd_cb *rfcp;
 
 	for (;;) {
-		spin_lock_irqsave(&rcu_fwd_lock, flags);
-		rfcp = rcu_fwd_cb_head;
+		spin_lock_irqsave(&rfp->rcu_fwd_lock, flags);
+		rfcp = rfp->rcu_fwd_cb_head;
 		if (!rfcp) {
-			spin_unlock_irqrestore(&rcu_fwd_lock, flags);
+			spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags);
 			break;
 		}
-		rcu_fwd_cb_head = rfcp->rfc_next;
-		if (!rcu_fwd_cb_head)
-			rcu_fwd_cb_tail = &rcu_fwd_cb_head;
-		spin_unlock_irqrestore(&rcu_fwd_lock, flags);
+		rfp->rcu_fwd_cb_head = rfcp->rfc_next;
+		if (!rfp->rcu_fwd_cb_head)
+			rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head;
+		spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags);
 		kfree(rfcp);
 		freed++;
 		rcu_torture_fwd_prog_cond_resched(freed);
+		if (tick_nohz_full_enabled()) {
+			local_irq_save(flags);
+			rcu_momentary_dyntick_idle();
+			local_irq_restore(flags);
+		}
 	}
 	return freed;
 }
 
 /* Carry out need_resched()/cond_resched() forward-progress testing. */
-static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)
+static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
+				    int *tested, int *tested_tries)
 {
 	unsigned long cver;
 	unsigned long dur;
@@ -1794,8 +1954,8 @@
 	sd = cur_ops->stall_dur() + 1;
 	sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div;
 	dur = sd4 + torture_random(&trs) % (sd - sd4);
-	WRITE_ONCE(rcu_fwd_startat, jiffies);
-	stopat = rcu_fwd_startat + dur;
+	WRITE_ONCE(rfp->rcu_fwd_startat, jiffies);
+	stopat = rfp->rcu_fwd_startat + dur;
 	while (time_before(jiffies, stopat) &&
 	       !shutdown_time_arrived() &&
 	       !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) {
@@ -1803,7 +1963,7 @@
 		udelay(10);
 		cur_ops->readunlock(idx);
 		if (!fwd_progress_need_resched || need_resched())
-			rcu_torture_fwd_prog_cond_resched(1);
+			cond_resched();
 	}
 	(*tested_tries)++;
 	if (!time_before(jiffies, stopat) &&
@@ -1830,9 +1990,10 @@
 }
 
 /* Carry out call_rcu() forward-progress testing. */
-static void rcu_torture_fwd_prog_cr(void)
+static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
 {
 	unsigned long cver;
+	unsigned long flags;
 	unsigned long gps;
 	int i;
 	long n_launders;
@@ -1853,22 +2014,23 @@
 	/* Loop continuously posting RCU callbacks. */
 	WRITE_ONCE(rcu_fwd_cb_nodelay, true);
 	cur_ops->sync(); /* Later readers see above write. */
-	WRITE_ONCE(rcu_fwd_startat, jiffies);
-	stopat = rcu_fwd_startat + MAX_FWD_CB_JIFFIES;
+	WRITE_ONCE(rfp->rcu_fwd_startat, jiffies);
+	stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES;
 	n_launders = 0;
-	n_launders_cb = 0;
+	rfp->n_launders_cb = 0; // Hoist initialization for multi-kthread
 	n_launders_sa = 0;
 	n_max_cbs = 0;
 	n_max_gps = 0;
-	for (i = 0; i < ARRAY_SIZE(n_launders_hist); i++)
-		n_launders_hist[i].n_launders = 0;
+	for (i = 0; i < ARRAY_SIZE(rfp->n_launders_hist); i++)
+		rfp->n_launders_hist[i].n_launders = 0;
 	cver = READ_ONCE(rcu_torture_current_version);
 	gps = cur_ops->get_gp_seq();
-	rcu_launder_gp_seq_start = gps;
+	rfp->rcu_launder_gp_seq_start = gps;
+	tick_dep_set_task(current, TICK_DEP_BIT_RCU);
 	while (time_before(jiffies, stopat) &&
 	       !shutdown_time_arrived() &&
 	       !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) {
-		rfcp = READ_ONCE(rcu_fwd_cb_head);
+		rfcp = READ_ONCE(rfp->rcu_fwd_cb_head);
 		rfcpn = NULL;
 		if (rfcp)
 			rfcpn = READ_ONCE(rfcp->rfc_next);
@@ -1876,7 +2038,7 @@
 			if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS &&
 			    ++n_max_gps >= MIN_FWD_CBS_LAUNDERED)
 				break;
-			rcu_fwd_cb_head = rfcpn;
+			rfp->rcu_fwd_cb_head = rfcpn;
 			n_launders++;
 			n_launders_sa++;
 		} else {
@@ -1888,29 +2050,36 @@
 			n_max_cbs++;
 			n_launders_sa = 0;
 			rfcp->rfc_gps = 0;
+			rfcp->rfc_rfp = rfp;
 		}
 		cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr);
 		rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs);
+		if (tick_nohz_full_enabled()) {
+			local_irq_save(flags);
+			rcu_momentary_dyntick_idle();
+			local_irq_restore(flags);
+		}
 	}
 	stoppedat = jiffies;
-	n_launders_cb_snap = READ_ONCE(n_launders_cb);
+	n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb);
 	cver = READ_ONCE(rcu_torture_current_version) - cver;
 	gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps);
 	cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */
-	(void)rcu_torture_fwd_prog_cbfree();
+	(void)rcu_torture_fwd_prog_cbfree(rfp);
 
 	if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) &&
 	    !shutdown_time_arrived()) {
 		WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED);
 		pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n",
 			 __func__,
-			 stoppedat - rcu_fwd_startat, jiffies - stoppedat,
+			 stoppedat - rfp->rcu_fwd_startat, jiffies - stoppedat,
 			 n_launders + n_max_cbs - n_launders_cb_snap,
 			 n_launders, n_launders_sa,
 			 n_max_gps, n_max_cbs, cver, gps);
-		rcu_torture_fwd_cb_hist();
+		rcu_torture_fwd_cb_hist(rfp);
 	}
 	schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */
+	tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
 	WRITE_ONCE(rcu_fwd_cb_nodelay, false);
 }
 
@@ -1922,23 +2091,32 @@
 static int rcutorture_oom_notify(struct notifier_block *self,
 				 unsigned long notused, void *nfreed)
 {
+	struct rcu_fwd *rfp;
+
+	mutex_lock(&rcu_fwd_mutex);
+	rfp = rcu_fwds;
+	if (!rfp) {
+		mutex_unlock(&rcu_fwd_mutex);
+		return NOTIFY_OK;
+	}
 	WARN(1, "%s invoked upon OOM during forward-progress testing.\n",
 	     __func__);
-	rcu_torture_fwd_cb_hist();
-	rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rcu_fwd_startat)) / 2);
+	rcu_torture_fwd_cb_hist(rfp);
+	rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp->rcu_fwd_startat)) / 2);
 	WRITE_ONCE(rcu_fwd_emergency_stop, true);
 	smp_mb(); /* Emergency stop before free and wait to avoid hangs. */
 	pr_info("%s: Freed %lu RCU callbacks.\n",
-		__func__, rcu_torture_fwd_prog_cbfree());
+		__func__, rcu_torture_fwd_prog_cbfree(rfp));
 	rcu_barrier();
 	pr_info("%s: Freed %lu RCU callbacks.\n",
-		__func__, rcu_torture_fwd_prog_cbfree());
+		__func__, rcu_torture_fwd_prog_cbfree(rfp));
 	rcu_barrier();
 	pr_info("%s: Freed %lu RCU callbacks.\n",
-		__func__, rcu_torture_fwd_prog_cbfree());
+		__func__, rcu_torture_fwd_prog_cbfree(rfp));
 	smp_mb(); /* Frees before return to avoid redoing OOM. */
 	(*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */
 	pr_info("%s returning after OOM processing.\n", __func__);
+	mutex_unlock(&rcu_fwd_mutex);
 	return NOTIFY_OK;
 }
 
@@ -1949,6 +2127,7 @@
 /* Carry out grace-period forward-progress testing. */
 static int rcu_torture_fwd_prog(void *args)
 {
+	struct rcu_fwd *rfp = args;
 	int tested = 0;
 	int tested_tries = 0;
 
@@ -1959,10 +2138,11 @@
 	do {
 		schedule_timeout_interruptible(fwd_progress_holdoff * HZ);
 		WRITE_ONCE(rcu_fwd_emergency_stop, false);
-		register_oom_notifier(&rcutorture_oom_nb);
-		rcu_torture_fwd_prog_nr(&tested, &tested_tries);
-		rcu_torture_fwd_prog_cr();
-		unregister_oom_notifier(&rcutorture_oom_nb);
+		if (!IS_ENABLED(CONFIG_TINY_RCU) ||
+		    rcu_inkernel_boot_has_ended())
+			rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries);
+		if (rcu_inkernel_boot_has_ended())
+			rcu_torture_fwd_prog_cr(rfp);
 
 		/* Avoid slow periods, better to test when busy. */
 		stutter_wait("rcu_torture_fwd_prog");
@@ -1977,6 +2157,8 @@
 /* If forward-progress checking is requested and feasible, spawn the thread. */
 static int __init rcu_torture_fwd_prog_init(void)
 {
+	struct rcu_fwd *rfp;
+
 	if (!fwd_progress)
 		return 0; /* Not requested, so don't do it. */
 	if (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0 ||
@@ -1995,8 +2177,29 @@
 		fwd_progress_holdoff = 1;
 	if (fwd_progress_div <= 0)
 		fwd_progress_div = 4;
-	return torture_create_kthread(rcu_torture_fwd_prog,
-				      NULL, fwd_prog_task);
+	rfp = kzalloc(sizeof(*rfp), GFP_KERNEL);
+	if (!rfp)
+		return -ENOMEM;
+	spin_lock_init(&rfp->rcu_fwd_lock);
+	rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head;
+	mutex_lock(&rcu_fwd_mutex);
+	rcu_fwds = rfp;
+	mutex_unlock(&rcu_fwd_mutex);
+	register_oom_notifier(&rcutorture_oom_nb);
+	return torture_create_kthread(rcu_torture_fwd_prog, rfp, fwd_prog_task);
+}
+
+static void rcu_torture_fwd_prog_cleanup(void)
+{
+	struct rcu_fwd *rfp;
+
+	torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task);
+	rfp = rcu_fwds;
+	mutex_lock(&rcu_fwd_mutex);
+	rcu_fwds = NULL;
+	mutex_unlock(&rcu_fwd_mutex);
+	unregister_oom_notifier(&rcutorture_oom_nb);
+	kfree(rfp);
 }
 
 /* Callback function for RCU barrier testing. */
@@ -2005,11 +2208,19 @@
 	atomic_inc(&barrier_cbs_invoked);
 }
 
+/* IPI handler to get callback posted on desired CPU, if online. */
+static void rcu_torture_barrier1cb(void *rcu_void)
+{
+	struct rcu_head *rhp = rcu_void;
+
+	cur_ops->call(rhp, rcu_torture_barrier_cbf);
+}
+
 /* kthread function to register callbacks used to test RCU barriers. */
 static int rcu_torture_barrier_cbs(void *arg)
 {
 	long myid = (long)arg;
-	bool lastphase = 0;
+	bool lastphase = false;
 	bool newphase;
 	struct rcu_head rcu;
 
@@ -2028,9 +2239,11 @@
 		 * The above smp_load_acquire() ensures barrier_phase load
 		 * is ordered before the following ->call().
 		 */
-		local_irq_disable(); /* Just to test no-irq call_rcu(). */
-		cur_ops->call(&rcu, rcu_torture_barrier_cbf);
-		local_irq_enable();
+		if (smp_call_function_single(myid, rcu_torture_barrier1cb,
+					     &rcu, 1)) {
+			// IPI failed, so use direct call from current CPU.
+			cur_ops->call(&rcu, rcu_torture_barrier_cbf);
+		}
 		if (atomic_dec_and_test(&barrier_cbs_count))
 			wake_up(&barrier_wq);
 	} while (!torture_must_stop());
@@ -2066,7 +2279,21 @@
 			pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
 			       atomic_read(&barrier_cbs_invoked),
 			       n_barrier_cbs);
-			WARN_ON_ONCE(1);
+			WARN_ON(1);
+			// Wait manually for the remaining callbacks
+			i = 0;
+			do {
+				if (WARN_ON(i++ > HZ))
+					i = INT_MIN;
+				schedule_timeout_interruptible(1);
+				cur_ops->cb_barrier();
+			} while (atomic_read(&barrier_cbs_invoked) !=
+				 n_barrier_cbs &&
+				 !torture_must_stop());
+			smp_mb(); // Can't trust ordering if broken.
+			if (!torture_must_stop())
+				pr_err("Recovered: barrier_cbs_invoked = %d\n",
+				       atomic_read(&barrier_cbs_invoked));
 		} else {
 			n_barrier_successes++;
 		}
@@ -2156,6 +2383,99 @@
 	return true;
 }
 
+static bool read_exit_child_stop;
+static bool read_exit_child_stopped;
+static wait_queue_head_t read_exit_wq;
+
+// Child kthread which just does an rcutorture reader and exits.
+static int rcu_torture_read_exit_child(void *trsp_in)
+{
+	struct torture_random_state *trsp = trsp_in;
+
+	set_user_nice(current, MAX_NICE);
+	// Minimize time between reading and exiting.
+	while (!kthread_should_stop())
+		schedule_timeout_uninterruptible(1);
+	(void)rcu_torture_one_read(trsp);
+	return 0;
+}
+
+// Parent kthread which creates and destroys read-exit child kthreads.
+static int rcu_torture_read_exit(void *unused)
+{
+	int count = 0;
+	bool errexit = false;
+	int i;
+	struct task_struct *tsp;
+	DEFINE_TORTURE_RANDOM(trs);
+
+	// Allocate and initialize.
+	set_user_nice(current, MAX_NICE);
+	VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of test");
+
+	// Each pass through this loop does one read-exit episode.
+	do {
+		if (++count > read_exit_burst) {
+			VERBOSE_TOROUT_STRING("rcu_torture_read_exit: End of episode");
+			rcu_barrier(); // Wait for task_struct free, avoid OOM.
+			for (i = 0; i < read_exit_delay; i++) {
+				schedule_timeout_uninterruptible(HZ);
+				if (READ_ONCE(read_exit_child_stop))
+					break;
+			}
+			if (!READ_ONCE(read_exit_child_stop))
+				VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of episode");
+			count = 0;
+		}
+		if (READ_ONCE(read_exit_child_stop))
+			break;
+		// Spawn child.
+		tsp = kthread_run(rcu_torture_read_exit_child,
+				     &trs, "%s",
+				     "rcu_torture_read_exit_child");
+		if (IS_ERR(tsp)) {
+			VERBOSE_TOROUT_ERRSTRING("out of memory");
+			errexit = true;
+			tsp = NULL;
+			break;
+		}
+		cond_resched();
+		kthread_stop(tsp);
+		n_read_exits ++;
+		stutter_wait("rcu_torture_read_exit");
+	} while (!errexit && !READ_ONCE(read_exit_child_stop));
+
+	// Clean up and exit.
+	smp_store_release(&read_exit_child_stopped, true); // After reaping.
+	smp_mb(); // Store before wakeup.
+	wake_up(&read_exit_wq);
+	while (!torture_must_stop())
+		schedule_timeout_uninterruptible(1);
+	torture_kthread_stopping("rcu_torture_read_exit");
+	return 0;
+}
+
+static int rcu_torture_read_exit_init(void)
+{
+	if (read_exit_burst <= 0)
+		return -EINVAL;
+	init_waitqueue_head(&read_exit_wq);
+	read_exit_child_stop = false;
+	read_exit_child_stopped = false;
+	return torture_create_kthread(rcu_torture_read_exit, NULL,
+				      read_exit_task);
+}
+
+static void rcu_torture_read_exit_cleanup(void)
+{
+	if (!read_exit_task)
+		return;
+	WRITE_ONCE(read_exit_child_stop, true);
+	smp_mb(); // Above write before wait.
+	wait_event(read_exit_wq, smp_load_acquire(&read_exit_child_stopped));
+	torture_stop_kthread(rcutorture_read_exit, read_exit_task);
+}
+
 static enum cpuhp_state rcutor_hp;
 
 static void
@@ -2177,8 +2497,9 @@
 	}
 
 	show_rcu_gp_kthreads();
+	rcu_torture_read_exit_cleanup();
 	rcu_torture_barrier_cleanup();
-	torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task);
+	rcu_torture_fwd_prog_cleanup();
 	torture_stop_kthread(rcu_torture_stall, stall_task);
 	torture_stop_kthread(rcu_torture_writer, writer_task);
 
@@ -2188,7 +2509,6 @@
 					     reader_tasks[i]);
 		kfree(reader_tasks);
 	}
-	rcu_torture_current = NULL;
 
 	if (fakewriter_tasks) {
 		for (i = 0; i < nfakewriters; i++) {
@@ -2201,8 +2521,9 @@
 
 	rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
 	srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
-	pr_alert("%s:  End-test grace-period state: g%lu f%#x\n",
-		 cur_ops->name, gp_seq, flags);
+	pr_alert("%s:  End-test grace-period state: g%ld f%#x total-gps=%ld\n",
+		 cur_ops->name, (long)gp_seq, flags,
+		 rcutorture_seq_diff(gp_seq, start_gp_seq));
 	torture_stop_kthread(rcu_torture_stats, stats_task);
 	torture_stop_kthread(rcu_torture_fqs, fqs_task);
 	if (rcu_torture_can_boost())
@@ -2326,9 +2647,12 @@
 	long i;
 	int cpu;
 	int firsterr = 0;
+	int flags = 0;
+	unsigned long gp_seq = 0;
 	static struct rcu_torture_ops *torture_ops[] = {
 		&rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
-		&busted_srcud_ops, &tasks_ops, &trivial_ops,
+		&busted_srcud_ops, &tasks_ops, &tasks_rude_ops,
+		&tasks_tracing_ops, &trivial_ops,
 	};
 
 	if (!torture_init_begin(torture_type, verbose))
@@ -2367,6 +2691,11 @@
 			nrealreaders = 1;
 	}
 	rcu_torture_print_module_parms(cur_ops, "Start of test");
+	rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
+	srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
+	start_gp_seq = gp_seq;
+	pr_alert("%s:  Start-test grace-period state: g%ld f%#x\n",
+		 cur_ops->name, (long)gp_seq, flags);
 
 	/* Set up the freelist. */
 
@@ -2499,6 +2828,9 @@
 	firsterr = rcu_torture_barrier_init();
 	if (firsterr)
 		goto unwind;
+	firsterr = rcu_torture_read_exit_init();
+	if (firsterr)
+		goto unwind;
 	if (object_debug)
 		rcu_test_debug_objects();
 	torture_init_end();
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
new file mode 100644
index 0000000..952595c
--- /dev/null
+++ b/kernel/rcu/refscale.c
@@ -0,0 +1,719 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Scalability test comparing RCU vs other mechanisms
+// for acquiring references on objects.
+//
+// Copyright (C) Google, 2020.
+//
+// Author: Joel Fernandes <joel@joelfernandes.org>
+
+#define pr_fmt(fmt) fmt
+
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kthread.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/notifier.h>
+#include <linux/percpu.h>
+#include <linux/rcupdate.h>
+#include <linux/rcupdate_trace.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/stat.h>
+#include <linux/srcu.h>
+#include <linux/slab.h>
+#include <linux/torture.h>
+#include <linux/types.h>
+
+#include "rcu.h"
+
+#define SCALE_FLAG "-ref-scale: "
+
+#define SCALEOUT(s, x...) \
+	pr_alert("%s" SCALE_FLAG s, scale_type, ## x)
+
+#define VERBOSE_SCALEOUT(s, x...) \
+	do { if (verbose) pr_alert("%s" SCALE_FLAG s, scale_type, ## x); } while (0)
+
+#define VERBOSE_SCALEOUT_ERRSTRING(s, x...) \
+	do { if (verbose) pr_alert("%s" SCALE_FLAG "!!! " s, scale_type, ## x); } while (0)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joel Fernandes (Google) <joel@joelfernandes.org>");
+
+static char *scale_type = "rcu";
+module_param(scale_type, charp, 0444);
+MODULE_PARM_DESC(scale_type, "Type of test (rcu, srcu, refcnt, rwsem, rwlock.");
+
+torture_param(int, verbose, 0, "Enable verbose debugging printk()s");
+
+// Wait until there are multiple CPUs before starting test.
+torture_param(int, holdoff, IS_BUILTIN(CONFIG_RCU_REF_SCALE_TEST) ? 10 : 0,
+	      "Holdoff time before test start (s)");
+// Number of loops per experiment, all readers execute operations concurrently.
+torture_param(long, loops, 10000, "Number of loops per experiment.");
+// Number of readers, with -1 defaulting to about 75% of the CPUs.
+torture_param(int, nreaders, -1, "Number of readers, -1 for 75% of CPUs.");
+// Number of runs.
+torture_param(int, nruns, 30, "Number of experiments to run.");
+// Reader delay in nanoseconds, 0 for no delay.
+torture_param(int, readdelay, 0, "Read-side delay in nanoseconds.");
+
+#ifdef MODULE
+# define REFSCALE_SHUTDOWN 0
+#else
+# define REFSCALE_SHUTDOWN 1
+#endif
+
+torture_param(bool, shutdown, REFSCALE_SHUTDOWN,
+	      "Shutdown at end of scalability tests.");
+
+struct reader_task {
+	struct task_struct *task;
+	int start_reader;
+	wait_queue_head_t wq;
+	u64 last_duration_ns;
+};
+
+static struct task_struct *shutdown_task;
+static wait_queue_head_t shutdown_wq;
+
+static struct task_struct *main_task;
+static wait_queue_head_t main_wq;
+static int shutdown_start;
+
+static struct reader_task *reader_tasks;
+
+// Number of readers that are part of the current experiment.
+static atomic_t nreaders_exp;
+
+// Use to wait for all threads to start.
+static atomic_t n_init;
+static atomic_t n_started;
+static atomic_t n_warmedup;
+static atomic_t n_cooleddown;
+
+// Track which experiment is currently running.
+static int exp_idx;
+
+// Operations vector for selecting different types of tests.
+struct ref_scale_ops {
+	void (*init)(void);
+	void (*cleanup)(void);
+	void (*readsection)(const int nloops);
+	void (*delaysection)(const int nloops, const int udl, const int ndl);
+	const char *name;
+};
+
+static struct ref_scale_ops *cur_ops;
+
+static void un_delay(const int udl, const int ndl)
+{
+	if (udl)
+		udelay(udl);
+	if (ndl)
+		ndelay(ndl);
+}
+
+static void ref_rcu_read_section(const int nloops)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		rcu_read_lock();
+		rcu_read_unlock();
+	}
+}
+
+static void ref_rcu_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		rcu_read_lock();
+		un_delay(udl, ndl);
+		rcu_read_unlock();
+	}
+}
+
+static void rcu_sync_scale_init(void)
+{
+}
+
+static struct ref_scale_ops rcu_ops = {
+	.init		= rcu_sync_scale_init,
+	.readsection	= ref_rcu_read_section,
+	.delaysection	= ref_rcu_delay_section,
+	.name		= "rcu"
+};
+
+// Definitions for SRCU ref scale testing.
+DEFINE_STATIC_SRCU(srcu_refctl_scale);
+static struct srcu_struct *srcu_ctlp = &srcu_refctl_scale;
+
+static void srcu_ref_scale_read_section(const int nloops)
+{
+	int i;
+	int idx;
+
+	for (i = nloops; i >= 0; i--) {
+		idx = srcu_read_lock(srcu_ctlp);
+		srcu_read_unlock(srcu_ctlp, idx);
+	}
+}
+
+static void srcu_ref_scale_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+	int idx;
+
+	for (i = nloops; i >= 0; i--) {
+		idx = srcu_read_lock(srcu_ctlp);
+		un_delay(udl, ndl);
+		srcu_read_unlock(srcu_ctlp, idx);
+	}
+}
+
+static struct ref_scale_ops srcu_ops = {
+	.init		= rcu_sync_scale_init,
+	.readsection	= srcu_ref_scale_read_section,
+	.delaysection	= srcu_ref_scale_delay_section,
+	.name		= "srcu"
+};
+
+// Definitions for RCU Tasks ref scale testing: Empty read markers.
+// These definitions also work for RCU Rude readers.
+static void rcu_tasks_ref_scale_read_section(const int nloops)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--)
+		continue;
+}
+
+static void rcu_tasks_ref_scale_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--)
+		un_delay(udl, ndl);
+}
+
+static struct ref_scale_ops rcu_tasks_ops = {
+	.init		= rcu_sync_scale_init,
+	.readsection	= rcu_tasks_ref_scale_read_section,
+	.delaysection	= rcu_tasks_ref_scale_delay_section,
+	.name		= "rcu-tasks"
+};
+
+// Definitions for RCU Tasks Trace ref scale testing.
+static void rcu_trace_ref_scale_read_section(const int nloops)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		rcu_read_lock_trace();
+		rcu_read_unlock_trace();
+	}
+}
+
+static void rcu_trace_ref_scale_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		rcu_read_lock_trace();
+		un_delay(udl, ndl);
+		rcu_read_unlock_trace();
+	}
+}
+
+static struct ref_scale_ops rcu_trace_ops = {
+	.init		= rcu_sync_scale_init,
+	.readsection	= rcu_trace_ref_scale_read_section,
+	.delaysection	= rcu_trace_ref_scale_delay_section,
+	.name		= "rcu-trace"
+};
+
+// Definitions for reference count
+static atomic_t refcnt;
+
+static void ref_refcnt_section(const int nloops)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		atomic_inc(&refcnt);
+		atomic_dec(&refcnt);
+	}
+}
+
+static void ref_refcnt_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		atomic_inc(&refcnt);
+		un_delay(udl, ndl);
+		atomic_dec(&refcnt);
+	}
+}
+
+static struct ref_scale_ops refcnt_ops = {
+	.init		= rcu_sync_scale_init,
+	.readsection	= ref_refcnt_section,
+	.delaysection	= ref_refcnt_delay_section,
+	.name		= "refcnt"
+};
+
+// Definitions for rwlock
+static rwlock_t test_rwlock;
+
+static void ref_rwlock_init(void)
+{
+	rwlock_init(&test_rwlock);
+}
+
+static void ref_rwlock_section(const int nloops)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		read_lock(&test_rwlock);
+		read_unlock(&test_rwlock);
+	}
+}
+
+static void ref_rwlock_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		read_lock(&test_rwlock);
+		un_delay(udl, ndl);
+		read_unlock(&test_rwlock);
+	}
+}
+
+static struct ref_scale_ops rwlock_ops = {
+	.init		= ref_rwlock_init,
+	.readsection	= ref_rwlock_section,
+	.delaysection	= ref_rwlock_delay_section,
+	.name		= "rwlock"
+};
+
+// Definitions for rwsem
+static struct rw_semaphore test_rwsem;
+
+static void ref_rwsem_init(void)
+{
+	init_rwsem(&test_rwsem);
+}
+
+static void ref_rwsem_section(const int nloops)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		down_read(&test_rwsem);
+		up_read(&test_rwsem);
+	}
+}
+
+static void ref_rwsem_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		down_read(&test_rwsem);
+		un_delay(udl, ndl);
+		up_read(&test_rwsem);
+	}
+}
+
+static struct ref_scale_ops rwsem_ops = {
+	.init		= ref_rwsem_init,
+	.readsection	= ref_rwsem_section,
+	.delaysection	= ref_rwsem_delay_section,
+	.name		= "rwsem"
+};
+
+static void rcu_scale_one_reader(void)
+{
+	if (readdelay <= 0)
+		cur_ops->readsection(loops);
+	else
+		cur_ops->delaysection(loops, readdelay / 1000, readdelay % 1000);
+}
+
+// Reader kthread.  Repeatedly does empty RCU read-side
+// critical section, minimizing update-side interference.
+static int
+ref_scale_reader(void *arg)
+{
+	unsigned long flags;
+	long me = (long)arg;
+	struct reader_task *rt = &(reader_tasks[me]);
+	u64 start;
+	s64 duration;
+
+	VERBOSE_SCALEOUT("ref_scale_reader %ld: task started", me);
+	set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
+	set_user_nice(current, MAX_NICE);
+	atomic_inc(&n_init);
+	if (holdoff)
+		schedule_timeout_interruptible(holdoff * HZ);
+repeat:
+	VERBOSE_SCALEOUT("ref_scale_reader %ld: waiting to start next experiment on cpu %d", me, smp_processor_id());
+
+	// Wait for signal that this reader can start.
+	wait_event(rt->wq, (atomic_read(&nreaders_exp) && smp_load_acquire(&rt->start_reader)) ||
+			   torture_must_stop());
+
+	if (torture_must_stop())
+		goto end;
+
+	// Make sure that the CPU is affinitized appropriately during testing.
+	WARN_ON_ONCE(smp_processor_id() != me);
+
+	WRITE_ONCE(rt->start_reader, 0);
+	if (!atomic_dec_return(&n_started))
+		while (atomic_read_acquire(&n_started))
+			cpu_relax();
+
+	VERBOSE_SCALEOUT("ref_scale_reader %ld: experiment %d started", me, exp_idx);
+
+
+	// To reduce noise, do an initial cache-warming invocation, check
+	// in, and then keep warming until everyone has checked in.
+	rcu_scale_one_reader();
+	if (!atomic_dec_return(&n_warmedup))
+		while (atomic_read_acquire(&n_warmedup))
+			rcu_scale_one_reader();
+	// Also keep interrupts disabled.  This also has the effect
+	// of preventing entries into slow path for rcu_read_unlock().
+	local_irq_save(flags);
+	start = ktime_get_mono_fast_ns();
+
+	rcu_scale_one_reader();
+
+	duration = ktime_get_mono_fast_ns() - start;
+	local_irq_restore(flags);
+
+	rt->last_duration_ns = WARN_ON_ONCE(duration < 0) ? 0 : duration;
+	// To reduce runtime-skew noise, do maintain-load invocations until
+	// everyone is done.
+	if (!atomic_dec_return(&n_cooleddown))
+		while (atomic_read_acquire(&n_cooleddown))
+			rcu_scale_one_reader();
+
+	if (atomic_dec_and_test(&nreaders_exp))
+		wake_up(&main_wq);
+
+	VERBOSE_SCALEOUT("ref_scale_reader %ld: experiment %d ended, (readers remaining=%d)",
+			me, exp_idx, atomic_read(&nreaders_exp));
+
+	if (!torture_must_stop())
+		goto repeat;
+end:
+	torture_kthread_stopping("ref_scale_reader");
+	return 0;
+}
+
+static void reset_readers(void)
+{
+	int i;
+	struct reader_task *rt;
+
+	for (i = 0; i < nreaders; i++) {
+		rt = &(reader_tasks[i]);
+
+		rt->last_duration_ns = 0;
+	}
+}
+
+// Print the results of each reader and return the sum of all their durations.
+static u64 process_durations(int n)
+{
+	int i;
+	struct reader_task *rt;
+	char buf1[64];
+	char *buf;
+	u64 sum = 0;
+
+	buf = kmalloc(128 + nreaders * 32, GFP_KERNEL);
+	if (!buf)
+		return 0;
+	buf[0] = 0;
+	sprintf(buf, "Experiment #%d (Format: <THREAD-NUM>:<Total loop time in ns>)",
+		exp_idx);
+
+	for (i = 0; i < n && !torture_must_stop(); i++) {
+		rt = &(reader_tasks[i]);
+		sprintf(buf1, "%d: %llu\t", i, rt->last_duration_ns);
+
+		if (i % 5 == 0)
+			strcat(buf, "\n");
+		strcat(buf, buf1);
+
+		sum += rt->last_duration_ns;
+	}
+	strcat(buf, "\n");
+
+	SCALEOUT("%s\n", buf);
+
+	kfree(buf);
+	return sum;
+}
+
+// The main_func is the main orchestrator, it performs a bunch of
+// experiments.  For every experiment, it orders all the readers
+// involved to start and waits for them to finish the experiment. It
+// then reads their timestamps and starts the next experiment. Each
+// experiment progresses from 1 concurrent reader to N of them at which
+// point all the timestamps are printed.
+static int main_func(void *arg)
+{
+	bool errexit = false;
+	int exp, r;
+	char buf1[64];
+	char *buf;
+	u64 *result_avg;
+
+	set_cpus_allowed_ptr(current, cpumask_of(nreaders % nr_cpu_ids));
+	set_user_nice(current, MAX_NICE);
+
+	VERBOSE_SCALEOUT("main_func task started");
+	result_avg = kzalloc(nruns * sizeof(*result_avg), GFP_KERNEL);
+	buf = kzalloc(64 + nruns * 32, GFP_KERNEL);
+	if (!result_avg || !buf) {
+		VERBOSE_SCALEOUT_ERRSTRING("out of memory");
+		errexit = true;
+	}
+	if (holdoff)
+		schedule_timeout_interruptible(holdoff * HZ);
+
+	// Wait for all threads to start.
+	atomic_inc(&n_init);
+	while (atomic_read(&n_init) < nreaders + 1)
+		schedule_timeout_uninterruptible(1);
+
+	// Start exp readers up per experiment
+	for (exp = 0; exp < nruns && !torture_must_stop(); exp++) {
+		if (errexit)
+			break;
+		if (torture_must_stop())
+			goto end;
+
+		reset_readers();
+		atomic_set(&nreaders_exp, nreaders);
+		atomic_set(&n_started, nreaders);
+		atomic_set(&n_warmedup, nreaders);
+		atomic_set(&n_cooleddown, nreaders);
+
+		exp_idx = exp;
+
+		for (r = 0; r < nreaders; r++) {
+			smp_store_release(&reader_tasks[r].start_reader, 1);
+			wake_up(&reader_tasks[r].wq);
+		}
+
+		VERBOSE_SCALEOUT("main_func: experiment started, waiting for %d readers",
+				nreaders);
+
+		wait_event(main_wq,
+			   !atomic_read(&nreaders_exp) || torture_must_stop());
+
+		VERBOSE_SCALEOUT("main_func: experiment ended");
+
+		if (torture_must_stop())
+			goto end;
+
+		result_avg[exp] = div_u64(1000 * process_durations(nreaders), nreaders * loops);
+	}
+
+	// Print the average of all experiments
+	SCALEOUT("END OF TEST. Calculating average duration per loop (nanoseconds)...\n");
+
+	if (!errexit) {
+		buf[0] = 0;
+		strcat(buf, "\n");
+		strcat(buf, "Runs\tTime(ns)\n");
+	}
+
+	for (exp = 0; exp < nruns; exp++) {
+		u64 avg;
+		u32 rem;
+
+		if (errexit)
+			break;
+		avg = div_u64_rem(result_avg[exp], 1000, &rem);
+		sprintf(buf1, "%d\t%llu.%03u\n", exp + 1, avg, rem);
+		strcat(buf, buf1);
+	}
+
+	if (!errexit)
+		SCALEOUT("%s", buf);
+
+	// This will shutdown everything including us.
+	if (shutdown) {
+		shutdown_start = 1;
+		wake_up(&shutdown_wq);
+	}
+
+	// Wait for torture to stop us
+	while (!torture_must_stop())
+		schedule_timeout_uninterruptible(1);
+
+end:
+	torture_kthread_stopping("main_func");
+	kfree(result_avg);
+	kfree(buf);
+	return 0;
+}
+
+static void
+ref_scale_print_module_parms(struct ref_scale_ops *cur_ops, const char *tag)
+{
+	pr_alert("%s" SCALE_FLAG
+		 "--- %s:  verbose=%d shutdown=%d holdoff=%d loops=%ld nreaders=%d nruns=%d readdelay=%d\n", scale_type, tag,
+		 verbose, shutdown, holdoff, loops, nreaders, nruns, readdelay);
+}
+
+static void
+ref_scale_cleanup(void)
+{
+	int i;
+
+	if (torture_cleanup_begin())
+		return;
+
+	if (!cur_ops) {
+		torture_cleanup_end();
+		return;
+	}
+
+	if (reader_tasks) {
+		for (i = 0; i < nreaders; i++)
+			torture_stop_kthread("ref_scale_reader",
+					     reader_tasks[i].task);
+	}
+	kfree(reader_tasks);
+
+	torture_stop_kthread("main_task", main_task);
+	kfree(main_task);
+
+	// Do scale-type-specific cleanup operations.
+	if (cur_ops->cleanup != NULL)
+		cur_ops->cleanup();
+
+	torture_cleanup_end();
+}
+
+// Shutdown kthread.  Just waits to be awakened, then shuts down system.
+static int
+ref_scale_shutdown(void *arg)
+{
+	wait_event(shutdown_wq, shutdown_start);
+
+	smp_mb(); // Wake before output.
+	ref_scale_cleanup();
+	kernel_power_off();
+
+	return -EINVAL;
+}
+
+static int __init
+ref_scale_init(void)
+{
+	long i;
+	int firsterr = 0;
+	static struct ref_scale_ops *scale_ops[] = {
+		&rcu_ops, &srcu_ops, &rcu_trace_ops, &rcu_tasks_ops,
+		&refcnt_ops, &rwlock_ops, &rwsem_ops,
+	};
+
+	if (!torture_init_begin(scale_type, verbose))
+		return -EBUSY;
+
+	for (i = 0; i < ARRAY_SIZE(scale_ops); i++) {
+		cur_ops = scale_ops[i];
+		if (strcmp(scale_type, cur_ops->name) == 0)
+			break;
+	}
+	if (i == ARRAY_SIZE(scale_ops)) {
+		pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type);
+		pr_alert("rcu-scale types:");
+		for (i = 0; i < ARRAY_SIZE(scale_ops); i++)
+			pr_cont(" %s", scale_ops[i]->name);
+		pr_cont("\n");
+		WARN_ON(!IS_MODULE(CONFIG_RCU_REF_SCALE_TEST));
+		firsterr = -EINVAL;
+		cur_ops = NULL;
+		goto unwind;
+	}
+	if (cur_ops->init)
+		cur_ops->init();
+
+	ref_scale_print_module_parms(cur_ops, "Start of test");
+
+	// Shutdown task
+	if (shutdown) {
+		init_waitqueue_head(&shutdown_wq);
+		firsterr = torture_create_kthread(ref_scale_shutdown, NULL,
+						  shutdown_task);
+		if (firsterr)
+			goto unwind;
+		schedule_timeout_uninterruptible(1);
+	}
+
+	// Reader tasks (default to ~75% of online CPUs).
+	if (nreaders < 0)
+		nreaders = (num_online_cpus() >> 1) + (num_online_cpus() >> 2);
+	reader_tasks = kcalloc(nreaders, sizeof(reader_tasks[0]),
+			       GFP_KERNEL);
+	if (!reader_tasks) {
+		VERBOSE_SCALEOUT_ERRSTRING("out of memory");
+		firsterr = -ENOMEM;
+		goto unwind;
+	}
+
+	VERBOSE_SCALEOUT("Starting %d reader threads\n", nreaders);
+
+	for (i = 0; i < nreaders; i++) {
+		firsterr = torture_create_kthread(ref_scale_reader, (void *)i,
+						  reader_tasks[i].task);
+		if (firsterr)
+			goto unwind;
+
+		init_waitqueue_head(&(reader_tasks[i].wq));
+	}
+
+	// Main Task
+	init_waitqueue_head(&main_wq);
+	firsterr = torture_create_kthread(main_func, NULL, main_task);
+	if (firsterr)
+		goto unwind;
+
+	torture_init_end();
+	return 0;
+
+unwind:
+	torture_init_end();
+	ref_scale_cleanup();
+	return firsterr;
+}
+
+module_init(ref_scale_init);
+module_exit(ref_scale_cleanup);
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 44d6606..26344dc 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -34,6 +34,7 @@
 	ssp->srcu_gp_running = false;
 	ssp->srcu_gp_waiting = false;
 	ssp->srcu_idx = 0;
+	ssp->srcu_idx_max = 0;
 	INIT_WORK(&ssp->srcu_work, srcu_drive_gp);
 	INIT_LIST_HEAD(&ssp->srcu_work.entry);
 	return 0;
@@ -84,6 +85,8 @@
 	WARN_ON(ssp->srcu_gp_waiting);
 	WARN_ON(ssp->srcu_cb_head);
 	WARN_ON(&ssp->srcu_cb_head != ssp->srcu_cb_tail);
+	WARN_ON(ssp->srcu_idx != ssp->srcu_idx_max);
+	WARN_ON(ssp->srcu_idx & 0x1);
 }
 EXPORT_SYMBOL_GPL(cleanup_srcu_struct);
 
@@ -103,7 +106,7 @@
 
 /*
  * Workqueue handler to drive one grace period and invoke any callbacks
- * that become ready as a result.  Single-CPU and !PREEMPT operation
+ * that become ready as a result.  Single-CPU and !PREEMPTION operation
  * means that we get away with murder on synchronization.  ;-)
  */
 void srcu_drive_gp(struct work_struct *wp)
@@ -114,7 +117,7 @@
 	struct srcu_struct *ssp;
 
 	ssp = container_of(wp, struct srcu_struct, srcu_work);
-	if (ssp->srcu_gp_running || !READ_ONCE(ssp->srcu_cb_head))
+	if (ssp->srcu_gp_running || USHORT_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
 		return; /* Already running or nothing to do. */
 
 	/* Remove recently arrived callbacks and wait for readers. */
@@ -124,11 +127,12 @@
 	ssp->srcu_cb_head = NULL;
 	ssp->srcu_cb_tail = &ssp->srcu_cb_head;
 	local_irq_enable();
-	idx = ssp->srcu_idx;
-	WRITE_ONCE(ssp->srcu_idx, !ssp->srcu_idx);
+	idx = (ssp->srcu_idx & 0x2) / 2;
+	WRITE_ONCE(ssp->srcu_idx, ssp->srcu_idx + 1);
 	WRITE_ONCE(ssp->srcu_gp_waiting, true);  /* srcu_read_unlock() wakes! */
 	swait_event_exclusive(ssp->srcu_wq, !READ_ONCE(ssp->srcu_lock_nesting[idx]));
 	WRITE_ONCE(ssp->srcu_gp_waiting, false); /* srcu_read_unlock() cheap. */
+	WRITE_ONCE(ssp->srcu_idx, ssp->srcu_idx + 1);
 
 	/* Invoke the callbacks we removed above. */
 	while (lh) {
@@ -146,11 +150,27 @@
 	 * straighten that out.
 	 */
 	WRITE_ONCE(ssp->srcu_gp_running, false);
-	if (READ_ONCE(ssp->srcu_cb_head))
+	if (USHORT_CMP_LT(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
 		schedule_work(&ssp->srcu_work);
 }
 EXPORT_SYMBOL_GPL(srcu_drive_gp);
 
+static void srcu_gp_start_if_needed(struct srcu_struct *ssp)
+{
+	unsigned short cookie;
+
+	cookie = get_state_synchronize_srcu(ssp);
+	if (USHORT_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie))
+		return;
+	WRITE_ONCE(ssp->srcu_idx_max, cookie);
+	if (!READ_ONCE(ssp->srcu_gp_running)) {
+		if (likely(srcu_init_done))
+			schedule_work(&ssp->srcu_work);
+		else if (list_empty(&ssp->srcu_work.entry))
+			list_add(&ssp->srcu_work.entry, &srcu_boot_list);
+	}
+}
+
 /*
  * Enqueue an SRCU callback on the specified srcu_struct structure,
  * initiating grace-period processing if it is not already running.
@@ -166,12 +186,7 @@
 	*ssp->srcu_cb_tail = rhp;
 	ssp->srcu_cb_tail = &rhp->next;
 	local_irq_restore(flags);
-	if (!READ_ONCE(ssp->srcu_gp_running)) {
-		if (likely(srcu_init_done))
-			schedule_work(&ssp->srcu_work);
-		else if (list_empty(&ssp->srcu_work.entry))
-			list_add(&ssp->srcu_work.entry, &srcu_boot_list);
-	}
+	srcu_gp_start_if_needed(ssp);
 }
 EXPORT_SYMBOL_GPL(call_srcu);
 
@@ -190,6 +205,48 @@
 }
 EXPORT_SYMBOL_GPL(synchronize_srcu);
 
+/*
+ * get_state_synchronize_srcu - Provide an end-of-grace-period cookie
+ */
+unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp)
+{
+	unsigned long ret;
+
+	barrier();
+	ret = (READ_ONCE(ssp->srcu_idx) + 3) & ~0x1;
+	barrier();
+	return ret & USHRT_MAX;
+}
+EXPORT_SYMBOL_GPL(get_state_synchronize_srcu);
+
+/*
+ * start_poll_synchronize_srcu - Provide cookie and start grace period
+ *
+ * The difference between this and get_state_synchronize_srcu() is that
+ * this function ensures that the poll_state_synchronize_srcu() will
+ * eventually return the value true.
+ */
+unsigned long start_poll_synchronize_srcu(struct srcu_struct *ssp)
+{
+	unsigned long ret = get_state_synchronize_srcu(ssp);
+
+	srcu_gp_start_if_needed(ssp);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(start_poll_synchronize_srcu);
+
+/*
+ * poll_state_synchronize_srcu - Has cookie's grace period ended?
+ */
+bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie)
+{
+	bool ret = USHORT_CMP_GE(READ_ONCE(ssp->srcu_idx), cookie);
+
+	barrier();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(poll_state_synchronize_srcu);
+
 /* Lockdep diagnostics.  */
 void __init rcu_scheduler_starting(void)
 {
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 21115ff..b882166 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -5,7 +5,7 @@
  * Copyright (C) IBM Corporation, 2006
  * Copyright (C) Fujitsu, 2012
  *
- * Author: Paul McKenney <paulmck@linux.ibm.com>
+ * Authors: Paul McKenney <paulmck@linux.ibm.com>
  *	   Lai Jiangshan <laijs@cn.fujitsu.com>
  *
  * For detailed explanation of Read-Copy Update mechanism see -
@@ -453,7 +453,7 @@
 	spin_unlock_rcu_node(sdp);  /* Interrupts remain disabled. */
 	smp_mb(); /* Order prior store to ->srcu_gp_seq_needed vs. GP start. */
 	rcu_seq_start(&ssp->srcu_gp_seq);
-	state = rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq));
+	state = rcu_seq_state(ssp->srcu_gp_seq);
 	WARN_ON_ONCE(state != SRCU_STATE_SCAN1);
 }
 
@@ -537,7 +537,7 @@
 	rcu_seq_end(&ssp->srcu_gp_seq);
 	gpseq = rcu_seq_current(&ssp->srcu_gp_seq);
 	if (ULONG_CMP_LT(ssp->srcu_gp_seq_needed_exp, gpseq))
-		ssp->srcu_gp_seq_needed_exp = gpseq;
+		WRITE_ONCE(ssp->srcu_gp_seq_needed_exp, gpseq);
 	spin_unlock_irq_rcu_node(ssp);
 	mutex_unlock(&ssp->srcu_gp_mutex);
 	/* A new grace period can start at this point.  But only one. */
@@ -553,7 +553,7 @@
 		snp->srcu_have_cbs[idx] = gpseq;
 		rcu_seq_set_state(&snp->srcu_have_cbs[idx], 1);
 		if (ULONG_CMP_LT(snp->srcu_gp_seq_needed_exp, gpseq))
-			snp->srcu_gp_seq_needed_exp = gpseq;
+			WRITE_ONCE(snp->srcu_gp_seq_needed_exp, gpseq);
 		mask = snp->srcu_data_have_cbs[idx];
 		snp->srcu_data_have_cbs[idx] = 0;
 		spin_unlock_irq_rcu_node(snp);
@@ -617,7 +617,7 @@
 	}
 	spin_lock_irqsave_rcu_node(ssp, flags);
 	if (ULONG_CMP_LT(ssp->srcu_gp_seq_needed_exp, s))
-		ssp->srcu_gp_seq_needed_exp = s;
+		WRITE_ONCE(ssp->srcu_gp_seq_needed_exp, s);
 	spin_unlock_irqrestore_rcu_node(ssp, flags);
 }
 
@@ -663,7 +663,7 @@
 		if (snp == sdp->mynode)
 			snp->srcu_data_have_cbs[idx] |= sdp->grpmask;
 		if (!do_norm && ULONG_CMP_LT(snp->srcu_gp_seq_needed_exp, s))
-			snp->srcu_gp_seq_needed_exp = s;
+			WRITE_ONCE(snp->srcu_gp_seq_needed_exp, s);
 		spin_unlock_irqrestore_rcu_node(snp, flags);
 	}
 
@@ -677,7 +677,7 @@
 		smp_store_release(&ssp->srcu_gp_seq_needed, s); /*^^^*/
 	}
 	if (!do_norm && ULONG_CMP_LT(ssp->srcu_gp_seq_needed_exp, s))
-		ssp->srcu_gp_seq_needed_exp = s;
+		WRITE_ONCE(ssp->srcu_gp_seq_needed_exp, s);
 
 	/* If grace period not already done and none in progress, start it. */
 	if (!rcu_seq_done(&ssp->srcu_gp_seq, s) &&
@@ -756,7 +756,7 @@
  * it, if this function was preempted for enough time for the counters
  * to wrap, it really doesn't matter whether or not we expedite the grace
  * period.  The extra overhead of a needlessly expedited grace period is
- * negligible when amoritized over that time period, and the extra latency
+ * negligible when amortized over that time period, and the extra latency
  * of a needlessly non-expedited grace period is similarly negligible.
  */
 static bool srcu_might_be_idle(struct srcu_struct *ssp)
@@ -767,14 +767,15 @@
 	unsigned long t;
 	unsigned long tlast;
 
+	check_init_srcu_struct(ssp);
 	/* If the local srcu_data structure has callbacks, not idle.  */
-	local_irq_save(flags);
-	sdp = this_cpu_ptr(ssp->sda);
+	sdp = raw_cpu_ptr(ssp->sda);
+	spin_lock_irqsave_rcu_node(sdp, flags);
 	if (rcu_segcblist_pend_cbs(&sdp->srcu_cblist)) {
-		local_irq_restore(flags);
+		spin_unlock_irqrestore_rcu_node(sdp, flags);
 		return false; /* Callbacks already present, so not idle. */
 	}
-	local_irq_restore(flags);
+	spin_unlock_irqrestore_rcu_node(sdp, flags);
 
 	/*
 	 * No local callbacks, so probabalistically probe global state.
@@ -808,6 +809,46 @@
 }
 
 /*
+ * Start an SRCU grace period, and also queue the callback if non-NULL.
+ */
+static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp,
+					     struct rcu_head *rhp, bool do_norm)
+{
+	unsigned long flags;
+	int idx;
+	bool needexp = false;
+	bool needgp = false;
+	unsigned long s;
+	struct srcu_data *sdp;
+
+	check_init_srcu_struct(ssp);
+	idx = srcu_read_lock(ssp);
+	sdp = raw_cpu_ptr(ssp->sda);
+	spin_lock_irqsave_rcu_node(sdp, flags);
+	if (rhp)
+		rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp);
+	rcu_segcblist_advance(&sdp->srcu_cblist,
+			      rcu_seq_current(&ssp->srcu_gp_seq));
+	s = rcu_seq_snap(&ssp->srcu_gp_seq);
+	(void)rcu_segcblist_accelerate(&sdp->srcu_cblist, s);
+	if (ULONG_CMP_LT(sdp->srcu_gp_seq_needed, s)) {
+		sdp->srcu_gp_seq_needed = s;
+		needgp = true;
+	}
+	if (!do_norm && ULONG_CMP_LT(sdp->srcu_gp_seq_needed_exp, s)) {
+		sdp->srcu_gp_seq_needed_exp = s;
+		needexp = true;
+	}
+	spin_unlock_irqrestore_rcu_node(sdp, flags);
+	if (needgp)
+		srcu_funnel_gp_start(ssp, sdp, s, do_norm);
+	else if (needexp)
+		srcu_funnel_exp_start(ssp, sdp->mynode, s);
+	srcu_read_unlock(ssp, idx);
+	return s;
+}
+
+/*
  * Enqueue an SRCU callback on the srcu_data structure associated with
  * the current CPU and the specified srcu_struct structure, initiating
  * grace-period processing if it is not already running.
@@ -838,14 +879,6 @@
 static void __call_srcu(struct srcu_struct *ssp, struct rcu_head *rhp,
 			rcu_callback_t func, bool do_norm)
 {
-	unsigned long flags;
-	int idx;
-	bool needexp = false;
-	bool needgp = false;
-	unsigned long s;
-	struct srcu_data *sdp;
-
-	check_init_srcu_struct(ssp);
 	if (debug_rcu_head_queue(rhp)) {
 		/* Probable double call_srcu(), so leak the callback. */
 		WRITE_ONCE(rhp->func, srcu_leak_callback);
@@ -853,29 +886,7 @@
 		return;
 	}
 	rhp->func = func;
-	idx = srcu_read_lock(ssp);
-	local_irq_save(flags);
-	sdp = this_cpu_ptr(ssp->sda);
-	spin_lock_rcu_node(sdp);
-	rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp, false);
-	rcu_segcblist_advance(&sdp->srcu_cblist,
-			      rcu_seq_current(&ssp->srcu_gp_seq));
-	s = rcu_seq_snap(&ssp->srcu_gp_seq);
-	(void)rcu_segcblist_accelerate(&sdp->srcu_cblist, s);
-	if (ULONG_CMP_LT(sdp->srcu_gp_seq_needed, s)) {
-		sdp->srcu_gp_seq_needed = s;
-		needgp = true;
-	}
-	if (!do_norm && ULONG_CMP_LT(sdp->srcu_gp_seq_needed_exp, s)) {
-		sdp->srcu_gp_seq_needed_exp = s;
-		needexp = true;
-	}
-	spin_unlock_irqrestore_rcu_node(sdp, flags);
-	if (needgp)
-		srcu_funnel_gp_start(ssp, sdp, s, do_norm);
-	else if (needexp)
-		srcu_funnel_exp_start(ssp, sdp->mynode, s);
-	srcu_read_unlock(ssp, idx);
+	(void)srcu_gp_start_if_needed(ssp, rhp, do_norm);
 }
 
 /**
@@ -1004,6 +1015,62 @@
 }
 EXPORT_SYMBOL_GPL(synchronize_srcu);
 
+/**
+ * get_state_synchronize_srcu - Provide an end-of-grace-period cookie
+ * @ssp: srcu_struct to provide cookie for.
+ *
+ * This function returns a cookie that can be passed to
+ * poll_state_synchronize_srcu(), which will return true if a full grace
+ * period has elapsed in the meantime.  It is the caller's responsibility
+ * to make sure that grace period happens, for example, by invoking
+ * call_srcu() after return from get_state_synchronize_srcu().
+ */
+unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp)
+{
+	// Any prior manipulation of SRCU-protected data must happen
+	// before the load from ->srcu_gp_seq.
+	smp_mb();
+	return rcu_seq_snap(&ssp->srcu_gp_seq);
+}
+EXPORT_SYMBOL_GPL(get_state_synchronize_srcu);
+
+/**
+ * start_poll_synchronize_srcu - Provide cookie and start grace period
+ * @ssp: srcu_struct to provide cookie for.
+ *
+ * This function returns a cookie that can be passed to
+ * poll_state_synchronize_srcu(), which will return true if a full grace
+ * period has elapsed in the meantime.  Unlike get_state_synchronize_srcu(),
+ * this function also ensures that any needed SRCU grace period will be
+ * started.  This convenience does come at a cost in terms of CPU overhead.
+ */
+unsigned long start_poll_synchronize_srcu(struct srcu_struct *ssp)
+{
+	return srcu_gp_start_if_needed(ssp, NULL, true);
+}
+EXPORT_SYMBOL_GPL(start_poll_synchronize_srcu);
+
+/**
+ * poll_state_synchronize_srcu - Has cookie's grace period ended?
+ * @ssp: srcu_struct to provide cookie for.
+ * @cookie: Return value from get_state_synchronize_srcu() or start_poll_synchronize_srcu().
+ *
+ * This function takes the cookie that was returned from either
+ * get_state_synchronize_srcu() or start_poll_synchronize_srcu(), and
+ * returns @true if an SRCU grace period elapsed since the time that the
+ * cookie was created.
+ */
+bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie)
+{
+	if (!rcu_seq_done(&ssp->srcu_gp_seq, cookie))
+		return false;
+	// Ensure that the end of the SRCU grace period happens before
+	// any subsequent code that the caller might execute.
+	smp_mb(); // ^^^
+	return true;
+}
+EXPORT_SYMBOL_GPL(poll_state_synchronize_srcu);
+
 /*
  * Callback function for srcu_barrier() use.
  */
@@ -1056,7 +1123,7 @@
 		sdp->srcu_barrier_head.func = srcu_barrier_cb;
 		debug_rcu_head_queue(&sdp->srcu_barrier_head);
 		if (!rcu_segcblist_entrain(&sdp->srcu_cblist,
-					   &sdp->srcu_barrier_head, 0)) {
+					   &sdp->srcu_barrier_head)) {
 			debug_rcu_head_unqueue(&sdp->srcu_barrier_head);
 			atomic_dec(&ssp->srcu_barrier_cpu_cnt);
 		}
@@ -1082,7 +1149,7 @@
  */
 unsigned long srcu_batches_completed(struct srcu_struct *ssp)
 {
-	return ssp->srcu_idx;
+	return READ_ONCE(ssp->srcu_idx);
 }
 EXPORT_SYMBOL_GPL(srcu_batches_completed);
 
@@ -1133,7 +1200,9 @@
 			return; /* readers present, retry later. */
 		}
 		srcu_flip(ssp);
+		spin_lock_irq_rcu_node(ssp);
 		rcu_seq_set_state(&ssp->srcu_gp_seq, SRCU_STATE_SCAN2);
+		spin_unlock_irq_rcu_node(ssp);
 	}
 
 	if (rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)) == SRCU_STATE_SCAN2) {
@@ -1269,8 +1338,8 @@
 		struct srcu_data *sdp;
 
 		sdp = per_cpu_ptr(ssp->sda, cpu);
-		u0 = sdp->srcu_unlock_count[!idx];
-		u1 = sdp->srcu_unlock_count[idx];
+		u0 = data_race(sdp->srcu_unlock_count[!idx]);
+		u1 = data_race(sdp->srcu_unlock_count[idx]);
 
 		/*
 		 * Make sure that a lock is always counted if the corresponding
@@ -1278,8 +1347,8 @@
 		 */
 		smp_rmb();
 
-		l0 = sdp->srcu_lock_count[!idx];
-		l1 = sdp->srcu_lock_count[idx];
+		l0 = data_race(sdp->srcu_lock_count[!idx]);
+		l1 = data_race(sdp->srcu_lock_count[idx]);
 
 		c0 = l0 - u0;
 		c1 = l1 - u1;
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
new file mode 100644
index 0000000..7c05c5a
--- /dev/null
+++ b/kernel/rcu/tasks.h
@@ -0,0 +1,1249 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Task-based RCU implementations.
+ *
+ * Copyright (C) 2020 Paul E. McKenney
+ */
+
+#ifdef CONFIG_TASKS_RCU_GENERIC
+
+////////////////////////////////////////////////////////////////////////
+//
+// Generic data structures.
+
+struct rcu_tasks;
+typedef void (*rcu_tasks_gp_func_t)(struct rcu_tasks *rtp);
+typedef void (*pregp_func_t)(void);
+typedef void (*pertask_func_t)(struct task_struct *t, struct list_head *hop);
+typedef void (*postscan_func_t)(struct list_head *hop);
+typedef void (*holdouts_func_t)(struct list_head *hop, bool ndrpt, bool *frptp);
+typedef void (*postgp_func_t)(struct rcu_tasks *rtp);
+
+/**
+ * Definition for a Tasks-RCU-like mechanism.
+ * @cbs_head: Head of callback list.
+ * @cbs_tail: Tail pointer for callback list.
+ * @cbs_wq: Wait queue allowning new callback to get kthread's attention.
+ * @cbs_lock: Lock protecting callback list.
+ * @kthread_ptr: This flavor's grace-period/callback-invocation kthread.
+ * @gp_func: This flavor's grace-period-wait function.
+ * @gp_state: Grace period's most recent state transition (debugging).
+ * @gp_sleep: Per-grace-period sleep to prevent CPU-bound looping.
+ * @init_fract: Initial backoff sleep interval.
+ * @gp_jiffies: Time of last @gp_state transition.
+ * @gp_start: Most recent grace-period start in jiffies.
+ * @n_gps: Number of grace periods completed since boot.
+ * @n_ipis: Number of IPIs sent to encourage grace periods to end.
+ * @n_ipis_fails: Number of IPI-send failures.
+ * @pregp_func: This flavor's pre-grace-period function (optional).
+ * @pertask_func: This flavor's per-task scan function (optional).
+ * @postscan_func: This flavor's post-task scan function (optional).
+ * @holdout_func: This flavor's holdout-list scan function (optional).
+ * @postgp_func: This flavor's post-grace-period function (optional).
+ * @call_func: This flavor's call_rcu()-equivalent function.
+ * @name: This flavor's textual name.
+ * @kname: This flavor's kthread name.
+ */
+struct rcu_tasks {
+	struct rcu_head *cbs_head;
+	struct rcu_head **cbs_tail;
+	struct wait_queue_head cbs_wq;
+	raw_spinlock_t cbs_lock;
+	int gp_state;
+	int gp_sleep;
+	int init_fract;
+	unsigned long gp_jiffies;
+	unsigned long gp_start;
+	unsigned long n_gps;
+	unsigned long n_ipis;
+	unsigned long n_ipis_fails;
+	struct task_struct *kthread_ptr;
+	rcu_tasks_gp_func_t gp_func;
+	pregp_func_t pregp_func;
+	pertask_func_t pertask_func;
+	postscan_func_t postscan_func;
+	holdouts_func_t holdouts_func;
+	postgp_func_t postgp_func;
+	call_rcu_func_t call_func;
+	char *name;
+	char *kname;
+};
+
+#define DEFINE_RCU_TASKS(rt_name, gp, call, n)				\
+static struct rcu_tasks rt_name =					\
+{									\
+	.cbs_tail = &rt_name.cbs_head,					\
+	.cbs_wq = __WAIT_QUEUE_HEAD_INITIALIZER(rt_name.cbs_wq),	\
+	.cbs_lock = __RAW_SPIN_LOCK_UNLOCKED(rt_name.cbs_lock),		\
+	.gp_func = gp,							\
+	.call_func = call,						\
+	.name = n,							\
+	.kname = #rt_name,						\
+}
+
+/* Track exiting tasks in order to allow them to be waited for. */
+DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu);
+
+/* Avoid IPIing CPUs early in the grace period. */
+#define RCU_TASK_IPI_DELAY (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB) ? HZ / 2 : 0)
+static int rcu_task_ipi_delay __read_mostly = RCU_TASK_IPI_DELAY;
+module_param(rcu_task_ipi_delay, int, 0644);
+
+/* Control stall timeouts.  Disable with <= 0, otherwise jiffies till stall. */
+#define RCU_TASK_STALL_TIMEOUT (HZ * 60 * 10)
+static int rcu_task_stall_timeout __read_mostly = RCU_TASK_STALL_TIMEOUT;
+module_param(rcu_task_stall_timeout, int, 0644);
+
+/* RCU tasks grace-period state for debugging. */
+#define RTGS_INIT		 0
+#define RTGS_WAIT_WAIT_CBS	 1
+#define RTGS_WAIT_GP		 2
+#define RTGS_PRE_WAIT_GP	 3
+#define RTGS_SCAN_TASKLIST	 4
+#define RTGS_POST_SCAN_TASKLIST	 5
+#define RTGS_WAIT_SCAN_HOLDOUTS	 6
+#define RTGS_SCAN_HOLDOUTS	 7
+#define RTGS_POST_GP		 8
+#define RTGS_WAIT_READERS	 9
+#define RTGS_INVOKE_CBS		10
+#define RTGS_WAIT_CBS		11
+#ifndef CONFIG_TINY_RCU
+static const char * const rcu_tasks_gp_state_names[] = {
+	"RTGS_INIT",
+	"RTGS_WAIT_WAIT_CBS",
+	"RTGS_WAIT_GP",
+	"RTGS_PRE_WAIT_GP",
+	"RTGS_SCAN_TASKLIST",
+	"RTGS_POST_SCAN_TASKLIST",
+	"RTGS_WAIT_SCAN_HOLDOUTS",
+	"RTGS_SCAN_HOLDOUTS",
+	"RTGS_POST_GP",
+	"RTGS_WAIT_READERS",
+	"RTGS_INVOKE_CBS",
+	"RTGS_WAIT_CBS",
+};
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+////////////////////////////////////////////////////////////////////////
+//
+// Generic code.
+
+/* Record grace-period phase and time. */
+static void set_tasks_gp_state(struct rcu_tasks *rtp, int newstate)
+{
+	rtp->gp_state = newstate;
+	rtp->gp_jiffies = jiffies;
+}
+
+#ifndef CONFIG_TINY_RCU
+/* Return state name. */
+static const char *tasks_gp_state_getname(struct rcu_tasks *rtp)
+{
+	int i = data_race(rtp->gp_state); // Let KCSAN detect update races
+	int j = READ_ONCE(i); // Prevent the compiler from reading twice
+
+	if (j >= ARRAY_SIZE(rcu_tasks_gp_state_names))
+		return "???";
+	return rcu_tasks_gp_state_names[j];
+}
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+// Enqueue a callback for the specified flavor of Tasks RCU.
+static void call_rcu_tasks_generic(struct rcu_head *rhp, rcu_callback_t func,
+				   struct rcu_tasks *rtp)
+{
+	unsigned long flags;
+	bool needwake;
+
+	rhp->next = NULL;
+	rhp->func = func;
+	raw_spin_lock_irqsave(&rtp->cbs_lock, flags);
+	needwake = !rtp->cbs_head;
+	WRITE_ONCE(*rtp->cbs_tail, rhp);
+	rtp->cbs_tail = &rhp->next;
+	raw_spin_unlock_irqrestore(&rtp->cbs_lock, flags);
+	/* We can't create the thread unless interrupts are enabled. */
+	if (needwake && READ_ONCE(rtp->kthread_ptr))
+		wake_up(&rtp->cbs_wq);
+}
+
+// Wait for a grace period for the specified flavor of Tasks RCU.
+static void synchronize_rcu_tasks_generic(struct rcu_tasks *rtp)
+{
+	/* Complain if the scheduler has not started.  */
+	RCU_LOCKDEP_WARN(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE,
+			 "synchronize_rcu_tasks called too soon");
+
+	/* Wait for the grace period. */
+	wait_rcu_gp(rtp->call_func);
+}
+
+/* RCU-tasks kthread that detects grace periods and invokes callbacks. */
+static int __noreturn rcu_tasks_kthread(void *arg)
+{
+	unsigned long flags;
+	struct rcu_head *list;
+	struct rcu_head *next;
+	struct rcu_tasks *rtp = arg;
+
+	/* Run on housekeeping CPUs by default.  Sysadm can move if desired. */
+	housekeeping_affine(current, HK_FLAG_RCU);
+	WRITE_ONCE(rtp->kthread_ptr, current); // Let GPs start!
+
+	/*
+	 * Each pass through the following loop makes one check for
+	 * newly arrived callbacks, and, if there are some, waits for
+	 * one RCU-tasks grace period and then invokes the callbacks.
+	 * This loop is terminated by the system going down.  ;-)
+	 */
+	for (;;) {
+		set_tasks_gp_state(rtp, RTGS_WAIT_CBS);
+
+		/* Pick up any new callbacks. */
+		raw_spin_lock_irqsave(&rtp->cbs_lock, flags);
+		smp_mb__after_spinlock(); // Order updates vs. GP.
+		list = rtp->cbs_head;
+		rtp->cbs_head = NULL;
+		rtp->cbs_tail = &rtp->cbs_head;
+		raw_spin_unlock_irqrestore(&rtp->cbs_lock, flags);
+
+		/* If there were none, wait a bit and start over. */
+		if (!list) {
+			wait_event_interruptible(rtp->cbs_wq,
+						 READ_ONCE(rtp->cbs_head));
+			if (!rtp->cbs_head) {
+				WARN_ON(signal_pending(current));
+				set_tasks_gp_state(rtp, RTGS_WAIT_WAIT_CBS);
+				schedule_timeout_idle(HZ/10);
+			}
+			continue;
+		}
+
+		// Wait for one grace period.
+		set_tasks_gp_state(rtp, RTGS_WAIT_GP);
+		rtp->gp_start = jiffies;
+		rtp->gp_func(rtp);
+		rtp->n_gps++;
+
+		/* Invoke the callbacks. */
+		set_tasks_gp_state(rtp, RTGS_INVOKE_CBS);
+		while (list) {
+			next = list->next;
+			local_bh_disable();
+			list->func(list);
+			local_bh_enable();
+			list = next;
+			cond_resched();
+		}
+		/* Paranoid sleep to keep this from entering a tight loop */
+		schedule_timeout_idle(rtp->gp_sleep);
+	}
+}
+
+/* Spawn RCU-tasks grace-period kthread. */
+static void __init rcu_spawn_tasks_kthread_generic(struct rcu_tasks *rtp)
+{
+	struct task_struct *t;
+
+	t = kthread_run(rcu_tasks_kthread, rtp, "%s_kthread", rtp->kname);
+	if (WARN_ONCE(IS_ERR(t), "%s: Could not start %s grace-period kthread, OOM is now expected behavior\n", __func__, rtp->name))
+		return;
+	smp_mb(); /* Ensure others see full kthread. */
+}
+
+#ifndef CONFIG_TINY_RCU
+
+/*
+ * Print any non-default Tasks RCU settings.
+ */
+static void __init rcu_tasks_bootup_oddness(void)
+{
+#if defined(CONFIG_TASKS_RCU) || defined(CONFIG_TASKS_TRACE_RCU)
+	if (rcu_task_stall_timeout != RCU_TASK_STALL_TIMEOUT)
+		pr_info("\tTasks-RCU CPU stall warnings timeout set to %d (rcu_task_stall_timeout).\n", rcu_task_stall_timeout);
+#endif /* #ifdef CONFIG_TASKS_RCU */
+#ifdef CONFIG_TASKS_RCU
+	pr_info("\tTrampoline variant of Tasks RCU enabled.\n");
+#endif /* #ifdef CONFIG_TASKS_RCU */
+#ifdef CONFIG_TASKS_RUDE_RCU
+	pr_info("\tRude variant of Tasks RCU enabled.\n");
+#endif /* #ifdef CONFIG_TASKS_RUDE_RCU */
+#ifdef CONFIG_TASKS_TRACE_RCU
+	pr_info("\tTracing variant of Tasks RCU enabled.\n");
+#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
+}
+
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+#ifndef CONFIG_TINY_RCU
+/* Dump out rcutorture-relevant state common to all RCU-tasks flavors. */
+static void show_rcu_tasks_generic_gp_kthread(struct rcu_tasks *rtp, char *s)
+{
+	pr_info("%s: %s(%d) since %lu g:%lu i:%lu/%lu %c%c %s\n",
+		rtp->kname,
+		tasks_gp_state_getname(rtp), data_race(rtp->gp_state),
+		jiffies - data_race(rtp->gp_jiffies),
+		data_race(rtp->n_gps),
+		data_race(rtp->n_ipis_fails), data_race(rtp->n_ipis),
+		".k"[!!data_race(rtp->kthread_ptr)],
+		".C"[!!data_race(rtp->cbs_head)],
+		s);
+}
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+static void exit_tasks_rcu_finish_trace(struct task_struct *t);
+
+#if defined(CONFIG_TASKS_RCU) || defined(CONFIG_TASKS_TRACE_RCU)
+
+////////////////////////////////////////////////////////////////////////
+//
+// Shared code between task-list-scanning variants of Tasks RCU.
+
+/* Wait for one RCU-tasks grace period. */
+static void rcu_tasks_wait_gp(struct rcu_tasks *rtp)
+{
+	struct task_struct *g, *t;
+	unsigned long lastreport;
+	LIST_HEAD(holdouts);
+	int fract;
+
+	set_tasks_gp_state(rtp, RTGS_PRE_WAIT_GP);
+	rtp->pregp_func();
+
+	/*
+	 * There were callbacks, so we need to wait for an RCU-tasks
+	 * grace period.  Start off by scanning the task list for tasks
+	 * that are not already voluntarily blocked.  Mark these tasks
+	 * and make a list of them in holdouts.
+	 */
+	set_tasks_gp_state(rtp, RTGS_SCAN_TASKLIST);
+	rcu_read_lock();
+	for_each_process_thread(g, t)
+		rtp->pertask_func(t, &holdouts);
+	rcu_read_unlock();
+
+	set_tasks_gp_state(rtp, RTGS_POST_SCAN_TASKLIST);
+	rtp->postscan_func(&holdouts);
+
+	/*
+	 * Each pass through the following loop scans the list of holdout
+	 * tasks, removing any that are no longer holdouts.  When the list
+	 * is empty, we are done.
+	 */
+	lastreport = jiffies;
+
+	// Start off with initial wait and slowly back off to 1 HZ wait.
+	fract = rtp->init_fract;
+	if (fract > HZ)
+		fract = HZ;
+
+	for (;;) {
+		bool firstreport;
+		bool needreport;
+		int rtst;
+
+		if (list_empty(&holdouts))
+			break;
+
+		/* Slowly back off waiting for holdouts */
+		set_tasks_gp_state(rtp, RTGS_WAIT_SCAN_HOLDOUTS);
+		schedule_timeout_idle(HZ/fract);
+
+		if (fract > 1)
+			fract--;
+
+		rtst = READ_ONCE(rcu_task_stall_timeout);
+		needreport = rtst > 0 && time_after(jiffies, lastreport + rtst);
+		if (needreport)
+			lastreport = jiffies;
+		firstreport = true;
+		WARN_ON(signal_pending(current));
+		set_tasks_gp_state(rtp, RTGS_SCAN_HOLDOUTS);
+		rtp->holdouts_func(&holdouts, needreport, &firstreport);
+	}
+
+	set_tasks_gp_state(rtp, RTGS_POST_GP);
+	rtp->postgp_func(rtp);
+}
+
+#endif /* #if defined(CONFIG_TASKS_RCU) || defined(CONFIG_TASKS_TRACE_RCU) */
+
+#ifdef CONFIG_TASKS_RCU
+
+////////////////////////////////////////////////////////////////////////
+//
+// Simple variant of RCU whose quiescent states are voluntary context
+// switch, cond_resched_rcu_qs(), user-space execution, and idle.
+// As such, grace periods can take one good long time.  There are no
+// read-side primitives similar to rcu_read_lock() and rcu_read_unlock()
+// because this implementation is intended to get the system into a safe
+// state for some of the manipulations involved in tracing and the like.
+// Finally, this implementation does not support high call_rcu_tasks()
+// rates from multiple CPUs.  If this is required, per-CPU callback lists
+// will be needed.
+
+/* Pre-grace-period preparation. */
+static void rcu_tasks_pregp_step(void)
+{
+	/*
+	 * Wait for all pre-existing t->on_rq and t->nvcsw transitions
+	 * to complete.  Invoking synchronize_rcu() suffices because all
+	 * these transitions occur with interrupts disabled.  Without this
+	 * synchronize_rcu(), a read-side critical section that started
+	 * before the grace period might be incorrectly seen as having
+	 * started after the grace period.
+	 *
+	 * This synchronize_rcu() also dispenses with the need for a
+	 * memory barrier on the first store to t->rcu_tasks_holdout,
+	 * as it forces the store to happen after the beginning of the
+	 * grace period.
+	 */
+	synchronize_rcu();
+}
+
+/* Per-task initial processing. */
+static void rcu_tasks_pertask(struct task_struct *t, struct list_head *hop)
+{
+	if (t != current && READ_ONCE(t->on_rq) && !is_idle_task(t)) {
+		get_task_struct(t);
+		t->rcu_tasks_nvcsw = READ_ONCE(t->nvcsw);
+		WRITE_ONCE(t->rcu_tasks_holdout, true);
+		list_add(&t->rcu_tasks_holdout_list, hop);
+	}
+}
+
+/* Processing between scanning taskslist and draining the holdout list. */
+static void rcu_tasks_postscan(struct list_head *hop)
+{
+	/*
+	 * Wait for tasks that are in the process of exiting.  This
+	 * does only part of the job, ensuring that all tasks that were
+	 * previously exiting reach the point where they have disabled
+	 * preemption, allowing the later synchronize_rcu() to finish
+	 * the job.
+	 */
+	synchronize_srcu(&tasks_rcu_exit_srcu);
+}
+
+/* See if tasks are still holding out, complain if so. */
+static void check_holdout_task(struct task_struct *t,
+			       bool needreport, bool *firstreport)
+{
+	int cpu;
+
+	if (!READ_ONCE(t->rcu_tasks_holdout) ||
+	    t->rcu_tasks_nvcsw != READ_ONCE(t->nvcsw) ||
+	    !READ_ONCE(t->on_rq) ||
+	    (IS_ENABLED(CONFIG_NO_HZ_FULL) &&
+	     !is_idle_task(t) && t->rcu_tasks_idle_cpu >= 0)) {
+		WRITE_ONCE(t->rcu_tasks_holdout, false);
+		list_del_init(&t->rcu_tasks_holdout_list);
+		put_task_struct(t);
+		return;
+	}
+	rcu_request_urgent_qs_task(t);
+	if (!needreport)
+		return;
+	if (*firstreport) {
+		pr_err("INFO: rcu_tasks detected stalls on tasks:\n");
+		*firstreport = false;
+	}
+	cpu = task_cpu(t);
+	pr_alert("%p: %c%c nvcsw: %lu/%lu holdout: %d idle_cpu: %d/%d\n",
+		 t, ".I"[is_idle_task(t)],
+		 "N."[cpu < 0 || !tick_nohz_full_cpu(cpu)],
+		 t->rcu_tasks_nvcsw, t->nvcsw, t->rcu_tasks_holdout,
+		 t->rcu_tasks_idle_cpu, cpu);
+	sched_show_task(t);
+}
+
+/* Scan the holdout lists for tasks no longer holding out. */
+static void check_all_holdout_tasks(struct list_head *hop,
+				    bool needreport, bool *firstreport)
+{
+	struct task_struct *t, *t1;
+
+	list_for_each_entry_safe(t, t1, hop, rcu_tasks_holdout_list) {
+		check_holdout_task(t, needreport, firstreport);
+		cond_resched();
+	}
+}
+
+/* Finish off the Tasks-RCU grace period. */
+static void rcu_tasks_postgp(struct rcu_tasks *rtp)
+{
+	/*
+	 * Because ->on_rq and ->nvcsw are not guaranteed to have a full
+	 * memory barriers prior to them in the schedule() path, memory
+	 * reordering on other CPUs could cause their RCU-tasks read-side
+	 * critical sections to extend past the end of the grace period.
+	 * However, because these ->nvcsw updates are carried out with
+	 * interrupts disabled, we can use synchronize_rcu() to force the
+	 * needed ordering on all such CPUs.
+	 *
+	 * This synchronize_rcu() also confines all ->rcu_tasks_holdout
+	 * accesses to be within the grace period, avoiding the need for
+	 * memory barriers for ->rcu_tasks_holdout accesses.
+	 *
+	 * In addition, this synchronize_rcu() waits for exiting tasks
+	 * to complete their final preempt_disable() region of execution,
+	 * cleaning up after the synchronize_srcu() above.
+	 */
+	synchronize_rcu();
+}
+
+void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func);
+DEFINE_RCU_TASKS(rcu_tasks, rcu_tasks_wait_gp, call_rcu_tasks, "RCU Tasks");
+
+/**
+ * call_rcu_tasks() - Queue an RCU for invocation task-based grace period
+ * @rhp: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all currently executing RCU
+ * read-side critical sections have completed. call_rcu_tasks() assumes
+ * that the read-side critical sections end at a voluntary context
+ * switch (not a preemption!), cond_resched_rcu_qs(), entry into idle,
+ * or transition to usermode execution.  As such, there are no read-side
+ * primitives analogous to rcu_read_lock() and rcu_read_unlock() because
+ * this primitive is intended to determine that all tasks have passed
+ * through a safe state, not so much for data-strcuture synchronization.
+ *
+ * See the description of call_rcu() for more detailed information on
+ * memory ordering guarantees.
+ */
+void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func)
+{
+	call_rcu_tasks_generic(rhp, func, &rcu_tasks);
+}
+EXPORT_SYMBOL_GPL(call_rcu_tasks);
+
+/**
+ * synchronize_rcu_tasks - wait until an rcu-tasks grace period has elapsed.
+ *
+ * Control will return to the caller some time after a full rcu-tasks
+ * grace period has elapsed, in other words after all currently
+ * executing rcu-tasks read-side critical sections have elapsed.  These
+ * read-side critical sections are delimited by calls to schedule(),
+ * cond_resched_tasks_rcu_qs(), idle execution, userspace execution, calls
+ * to synchronize_rcu_tasks(), and (in theory, anyway) cond_resched().
+ *
+ * This is a very specialized primitive, intended only for a few uses in
+ * tracing and other situations requiring manipulation of function
+ * preambles and profiling hooks.  The synchronize_rcu_tasks() function
+ * is not (yet) intended for heavy use from multiple CPUs.
+ *
+ * See the description of synchronize_rcu() for more detailed information
+ * on memory ordering guarantees.
+ */
+void synchronize_rcu_tasks(void)
+{
+	synchronize_rcu_tasks_generic(&rcu_tasks);
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu_tasks);
+
+/**
+ * rcu_barrier_tasks - Wait for in-flight call_rcu_tasks() callbacks.
+ *
+ * Although the current implementation is guaranteed to wait, it is not
+ * obligated to, for example, if there are no pending callbacks.
+ */
+void rcu_barrier_tasks(void)
+{
+	/* There is only one callback queue, so this is easy.  ;-) */
+	synchronize_rcu_tasks();
+}
+EXPORT_SYMBOL_GPL(rcu_barrier_tasks);
+
+static int __init rcu_spawn_tasks_kthread(void)
+{
+	rcu_tasks.gp_sleep = HZ / 10;
+	rcu_tasks.init_fract = 10;
+	rcu_tasks.pregp_func = rcu_tasks_pregp_step;
+	rcu_tasks.pertask_func = rcu_tasks_pertask;
+	rcu_tasks.postscan_func = rcu_tasks_postscan;
+	rcu_tasks.holdouts_func = check_all_holdout_tasks;
+	rcu_tasks.postgp_func = rcu_tasks_postgp;
+	rcu_spawn_tasks_kthread_generic(&rcu_tasks);
+	return 0;
+}
+
+#ifndef CONFIG_TINY_RCU
+static void show_rcu_tasks_classic_gp_kthread(void)
+{
+	show_rcu_tasks_generic_gp_kthread(&rcu_tasks, "");
+}
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+/* Do the srcu_read_lock() for the above synchronize_srcu().  */
+void exit_tasks_rcu_start(void) __acquires(&tasks_rcu_exit_srcu)
+{
+	preempt_disable();
+	current->rcu_tasks_idx = __srcu_read_lock(&tasks_rcu_exit_srcu);
+	preempt_enable();
+}
+
+/* Do the srcu_read_unlock() for the above synchronize_srcu().  */
+void exit_tasks_rcu_finish(void) __releases(&tasks_rcu_exit_srcu)
+{
+	struct task_struct *t = current;
+
+	preempt_disable();
+	__srcu_read_unlock(&tasks_rcu_exit_srcu, t->rcu_tasks_idx);
+	preempt_enable();
+	exit_tasks_rcu_finish_trace(t);
+}
+
+#else /* #ifdef CONFIG_TASKS_RCU */
+static inline void show_rcu_tasks_classic_gp_kthread(void) { }
+void exit_tasks_rcu_start(void) { }
+void exit_tasks_rcu_finish(void) { exit_tasks_rcu_finish_trace(current); }
+#endif /* #else #ifdef CONFIG_TASKS_RCU */
+
+#ifdef CONFIG_TASKS_RUDE_RCU
+
+////////////////////////////////////////////////////////////////////////
+//
+// "Rude" variant of Tasks RCU, inspired by Steve Rostedt's trick of
+// passing an empty function to schedule_on_each_cpu().  This approach
+// provides an asynchronous call_rcu_tasks_rude() API and batching
+// of concurrent calls to the synchronous synchronize_rcu_rude() API.
+// This sends IPIs far and wide and induces otherwise unnecessary context
+// switches on all online CPUs, whether idle or not.
+
+// Empty function to allow workqueues to force a context switch.
+static void rcu_tasks_be_rude(struct work_struct *work)
+{
+}
+
+// Wait for one rude RCU-tasks grace period.
+static void rcu_tasks_rude_wait_gp(struct rcu_tasks *rtp)
+{
+	rtp->n_ipis += cpumask_weight(cpu_online_mask);
+	schedule_on_each_cpu(rcu_tasks_be_rude);
+}
+
+void call_rcu_tasks_rude(struct rcu_head *rhp, rcu_callback_t func);
+DEFINE_RCU_TASKS(rcu_tasks_rude, rcu_tasks_rude_wait_gp, call_rcu_tasks_rude,
+		 "RCU Tasks Rude");
+
+/**
+ * call_rcu_tasks_rude() - Queue a callback rude task-based grace period
+ * @rhp: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all currently executing RCU
+ * read-side critical sections have completed. call_rcu_tasks_rude()
+ * assumes that the read-side critical sections end at context switch,
+ * cond_resched_rcu_qs(), or transition to usermode execution.  As such,
+ * there are no read-side primitives analogous to rcu_read_lock() and
+ * rcu_read_unlock() because this primitive is intended to determine
+ * that all tasks have passed through a safe state, not so much for
+ * data-strcuture synchronization.
+ *
+ * See the description of call_rcu() for more detailed information on
+ * memory ordering guarantees.
+ */
+void call_rcu_tasks_rude(struct rcu_head *rhp, rcu_callback_t func)
+{
+	call_rcu_tasks_generic(rhp, func, &rcu_tasks_rude);
+}
+EXPORT_SYMBOL_GPL(call_rcu_tasks_rude);
+
+/**
+ * synchronize_rcu_tasks_rude - wait for a rude rcu-tasks grace period
+ *
+ * Control will return to the caller some time after a rude rcu-tasks
+ * grace period has elapsed, in other words after all currently
+ * executing rcu-tasks read-side critical sections have elapsed.  These
+ * read-side critical sections are delimited by calls to schedule(),
+ * cond_resched_tasks_rcu_qs(), userspace execution, and (in theory,
+ * anyway) cond_resched().
+ *
+ * This is a very specialized primitive, intended only for a few uses in
+ * tracing and other situations requiring manipulation of function preambles
+ * and profiling hooks.  The synchronize_rcu_tasks_rude() function is not
+ * (yet) intended for heavy use from multiple CPUs.
+ *
+ * See the description of synchronize_rcu() for more detailed information
+ * on memory ordering guarantees.
+ */
+void synchronize_rcu_tasks_rude(void)
+{
+	synchronize_rcu_tasks_generic(&rcu_tasks_rude);
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu_tasks_rude);
+
+/**
+ * rcu_barrier_tasks_rude - Wait for in-flight call_rcu_tasks_rude() callbacks.
+ *
+ * Although the current implementation is guaranteed to wait, it is not
+ * obligated to, for example, if there are no pending callbacks.
+ */
+void rcu_barrier_tasks_rude(void)
+{
+	/* There is only one callback queue, so this is easy.  ;-) */
+	synchronize_rcu_tasks_rude();
+}
+EXPORT_SYMBOL_GPL(rcu_barrier_tasks_rude);
+
+static int __init rcu_spawn_tasks_rude_kthread(void)
+{
+	rcu_tasks_rude.gp_sleep = HZ / 10;
+	rcu_spawn_tasks_kthread_generic(&rcu_tasks_rude);
+	return 0;
+}
+
+#ifndef CONFIG_TINY_RCU
+static void show_rcu_tasks_rude_gp_kthread(void)
+{
+	show_rcu_tasks_generic_gp_kthread(&rcu_tasks_rude, "");
+}
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+#else /* #ifdef CONFIG_TASKS_RUDE_RCU */
+static void show_rcu_tasks_rude_gp_kthread(void) {}
+#endif /* #else #ifdef CONFIG_TASKS_RUDE_RCU */
+
+////////////////////////////////////////////////////////////////////////
+//
+// Tracing variant of Tasks RCU.  This variant is designed to be used
+// to protect tracing hooks, including those of BPF.  This variant
+// therefore:
+//
+// 1.	Has explicit read-side markers to allow finite grace periods
+//	in the face of in-kernel loops for PREEMPT=n builds.
+//
+// 2.	Protects code in the idle loop, exception entry/exit, and
+//	CPU-hotplug code paths, similar to the capabilities of SRCU.
+//
+// 3.	Avoids expensive read-side instruction, having overhead similar
+//	to that of Preemptible RCU.
+//
+// There are of course downsides.  The grace-period code can send IPIs to
+// CPUs, even when those CPUs are in the idle loop or in nohz_full userspace.
+// It is necessary to scan the full tasklist, much as for Tasks RCU.  There
+// is a single callback queue guarded by a single lock, again, much as for
+// Tasks RCU.  If needed, these downsides can be at least partially remedied.
+//
+// Perhaps most important, this variant of RCU does not affect the vanilla
+// flavors, rcu_preempt and rcu_sched.  The fact that RCU Tasks Trace
+// readers can operate from idle, offline, and exception entry/exit in no
+// way allows rcu_preempt and rcu_sched readers to also do so.
+
+// The lockdep state must be outside of #ifdef to be useful.
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key rcu_lock_trace_key;
+struct lockdep_map rcu_trace_lock_map =
+	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_trace", &rcu_lock_trace_key);
+EXPORT_SYMBOL_GPL(rcu_trace_lock_map);
+#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+
+#ifdef CONFIG_TASKS_TRACE_RCU
+
+static atomic_t trc_n_readers_need_end;		// Number of waited-for readers.
+static DECLARE_WAIT_QUEUE_HEAD(trc_wait);	// List of holdout tasks.
+
+// Record outstanding IPIs to each CPU.  No point in sending two...
+static DEFINE_PER_CPU(bool, trc_ipi_to_cpu);
+
+// The number of detections of task quiescent state relying on
+// heavyweight readers executing explicit memory barriers.
+static unsigned long n_heavy_reader_attempts;
+static unsigned long n_heavy_reader_updates;
+static unsigned long n_heavy_reader_ofl_updates;
+
+void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func);
+DEFINE_RCU_TASKS(rcu_tasks_trace, rcu_tasks_wait_gp, call_rcu_tasks_trace,
+		 "RCU Tasks Trace");
+
+/*
+ * This irq_work handler allows rcu_read_unlock_trace() to be invoked
+ * while the scheduler locks are held.
+ */
+static void rcu_read_unlock_iw(struct irq_work *iwp)
+{
+	wake_up(&trc_wait);
+}
+static DEFINE_IRQ_WORK(rcu_tasks_trace_iw, rcu_read_unlock_iw);
+
+/* If we are the last reader, wake up the grace-period kthread. */
+void rcu_read_unlock_trace_special(struct task_struct *t, int nesting)
+{
+	int nq = t->trc_reader_special.b.need_qs;
+
+	if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB) &&
+	    t->trc_reader_special.b.need_mb)
+		smp_mb(); // Pairs with update-side barriers.
+	// Update .need_qs before ->trc_reader_nesting for irq/NMI handlers.
+	if (nq)
+		WRITE_ONCE(t->trc_reader_special.b.need_qs, false);
+	WRITE_ONCE(t->trc_reader_nesting, nesting);
+	if (nq && atomic_dec_and_test(&trc_n_readers_need_end))
+		irq_work_queue(&rcu_tasks_trace_iw);
+}
+EXPORT_SYMBOL_GPL(rcu_read_unlock_trace_special);
+
+/* Add a task to the holdout list, if it is not already on the list. */
+static void trc_add_holdout(struct task_struct *t, struct list_head *bhp)
+{
+	if (list_empty(&t->trc_holdout_list)) {
+		get_task_struct(t);
+		list_add(&t->trc_holdout_list, bhp);
+	}
+}
+
+/* Remove a task from the holdout list, if it is in fact present. */
+static void trc_del_holdout(struct task_struct *t)
+{
+	if (!list_empty(&t->trc_holdout_list)) {
+		list_del_init(&t->trc_holdout_list);
+		put_task_struct(t);
+	}
+}
+
+/* IPI handler to check task state. */
+static void trc_read_check_handler(void *t_in)
+{
+	struct task_struct *t = current;
+	struct task_struct *texp = t_in;
+
+	// If the task is no longer running on this CPU, leave.
+	if (unlikely(texp != t)) {
+		if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end)))
+			wake_up(&trc_wait);
+		goto reset_ipi; // Already on holdout list, so will check later.
+	}
+
+	// If the task is not in a read-side critical section, and
+	// if this is the last reader, awaken the grace-period kthread.
+	if (likely(!t->trc_reader_nesting)) {
+		if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end)))
+			wake_up(&trc_wait);
+		// Mark as checked after decrement to avoid false
+		// positives on the above WARN_ON_ONCE().
+		WRITE_ONCE(t->trc_reader_checked, true);
+		goto reset_ipi;
+	}
+	// If we are racing with an rcu_read_unlock_trace(), try again later.
+	if (unlikely(t->trc_reader_nesting < 0)) {
+		if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end)))
+			wake_up(&trc_wait);
+		goto reset_ipi;
+	}
+	WRITE_ONCE(t->trc_reader_checked, true);
+
+	// Get here if the task is in a read-side critical section.  Set
+	// its state so that it will awaken the grace-period kthread upon
+	// exit from that critical section.
+	WARN_ON_ONCE(t->trc_reader_special.b.need_qs);
+	WRITE_ONCE(t->trc_reader_special.b.need_qs, true);
+
+reset_ipi:
+	// Allow future IPIs to be sent on CPU and for task.
+	// Also order this IPI handler against any later manipulations of
+	// the intended task.
+	smp_store_release(&per_cpu(trc_ipi_to_cpu, smp_processor_id()), false); // ^^^
+	smp_store_release(&texp->trc_ipi_to_cpu, -1); // ^^^
+}
+
+/* Callback function for scheduler to check locked-down task.  */
+static bool trc_inspect_reader(struct task_struct *t, void *arg)
+{
+	int cpu = task_cpu(t);
+	bool in_qs = false;
+	bool ofl = cpu_is_offline(cpu);
+
+	if (task_curr(t)) {
+		WARN_ON_ONCE(ofl && !is_idle_task(t));
+
+		// If no chance of heavyweight readers, do it the hard way.
+		if (!ofl && !IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB))
+			return false;
+
+		// If heavyweight readers are enabled on the remote task,
+		// we can inspect its state despite its currently running.
+		// However, we cannot safely change its state.
+		n_heavy_reader_attempts++;
+		if (!ofl && // Check for "running" idle tasks on offline CPUs.
+		    !rcu_dynticks_zero_in_eqs(cpu, &t->trc_reader_nesting))
+			return false; // No quiescent state, do it the hard way.
+		n_heavy_reader_updates++;
+		if (ofl)
+			n_heavy_reader_ofl_updates++;
+		in_qs = true;
+	} else {
+		in_qs = likely(!t->trc_reader_nesting);
+	}
+
+	// Mark as checked so that the grace-period kthread will
+	// remove it from the holdout list.
+	t->trc_reader_checked = true;
+
+	if (in_qs)
+		return true;  // Already in quiescent state, done!!!
+
+	// The task is in a read-side critical section, so set up its
+	// state so that it will awaken the grace-period kthread upon exit
+	// from that critical section.
+	atomic_inc(&trc_n_readers_need_end); // One more to wait on.
+	WARN_ON_ONCE(t->trc_reader_special.b.need_qs);
+	WRITE_ONCE(t->trc_reader_special.b.need_qs, true);
+	return true;
+}
+
+/* Attempt to extract the state for the specified task. */
+static void trc_wait_for_one_reader(struct task_struct *t,
+				    struct list_head *bhp)
+{
+	int cpu;
+
+	// If a previous IPI is still in flight, let it complete.
+	if (smp_load_acquire(&t->trc_ipi_to_cpu) != -1) // Order IPI
+		return;
+
+	// The current task had better be in a quiescent state.
+	if (t == current) {
+		t->trc_reader_checked = true;
+		WARN_ON_ONCE(t->trc_reader_nesting);
+		return;
+	}
+
+	// Attempt to nail down the task for inspection.
+	get_task_struct(t);
+	if (try_invoke_on_locked_down_task(t, trc_inspect_reader, NULL)) {
+		put_task_struct(t);
+		return;
+	}
+	put_task_struct(t);
+
+	// If currently running, send an IPI, either way, add to list.
+	trc_add_holdout(t, bhp);
+	if (task_curr(t) &&
+	    time_after(jiffies + 1, rcu_tasks_trace.gp_start + rcu_task_ipi_delay)) {
+		// The task is currently running, so try IPIing it.
+		cpu = task_cpu(t);
+
+		// If there is already an IPI outstanding, let it happen.
+		if (per_cpu(trc_ipi_to_cpu, cpu) || t->trc_ipi_to_cpu >= 0)
+			return;
+
+		atomic_inc(&trc_n_readers_need_end);
+		per_cpu(trc_ipi_to_cpu, cpu) = true;
+		t->trc_ipi_to_cpu = cpu;
+		rcu_tasks_trace.n_ipis++;
+		if (smp_call_function_single(cpu,
+					     trc_read_check_handler, t, 0)) {
+			// Just in case there is some other reason for
+			// failure than the target CPU being offline.
+			rcu_tasks_trace.n_ipis_fails++;
+			per_cpu(trc_ipi_to_cpu, cpu) = false;
+			t->trc_ipi_to_cpu = cpu;
+			if (atomic_dec_and_test(&trc_n_readers_need_end)) {
+				WARN_ON_ONCE(1);
+				wake_up(&trc_wait);
+			}
+		}
+	}
+}
+
+/* Initialize for a new RCU-tasks-trace grace period. */
+static void rcu_tasks_trace_pregp_step(void)
+{
+	int cpu;
+
+	// Allow for fast-acting IPIs.
+	atomic_set(&trc_n_readers_need_end, 1);
+
+	// There shouldn't be any old IPIs, but...
+	for_each_possible_cpu(cpu)
+		WARN_ON_ONCE(per_cpu(trc_ipi_to_cpu, cpu));
+
+	// Disable CPU hotplug across the tasklist scan.
+	// This also waits for all readers in CPU-hotplug code paths.
+	cpus_read_lock();
+}
+
+/* Do first-round processing for the specified task. */
+static void rcu_tasks_trace_pertask(struct task_struct *t,
+				    struct list_head *hop)
+{
+	// During early boot when there is only the one boot CPU, there
+	// is no idle task for the other CPUs. Just return.
+	if (unlikely(t == NULL))
+		return;
+
+	WRITE_ONCE(t->trc_reader_special.b.need_qs, false);
+	WRITE_ONCE(t->trc_reader_checked, false);
+	t->trc_ipi_to_cpu = -1;
+	trc_wait_for_one_reader(t, hop);
+}
+
+/*
+ * Do intermediate processing between task and holdout scans and
+ * pick up the idle tasks.
+ */
+static void rcu_tasks_trace_postscan(struct list_head *hop)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		rcu_tasks_trace_pertask(idle_task(cpu), hop);
+
+	// Re-enable CPU hotplug now that the tasklist scan has completed.
+	cpus_read_unlock();
+
+	// Wait for late-stage exiting tasks to finish exiting.
+	// These might have passed the call to exit_tasks_rcu_finish().
+	synchronize_rcu();
+	// Any tasks that exit after this point will set ->trc_reader_checked.
+}
+
+/* Show the state of a task stalling the current RCU tasks trace GP. */
+static void show_stalled_task_trace(struct task_struct *t, bool *firstreport)
+{
+	int cpu;
+
+	if (*firstreport) {
+		pr_err("INFO: rcu_tasks_trace detected stalls on tasks:\n");
+		*firstreport = false;
+	}
+	// FIXME: This should attempt to use try_invoke_on_nonrunning_task().
+	cpu = task_cpu(t);
+	pr_alert("P%d: %c%c%c nesting: %d%c cpu: %d\n",
+		 t->pid,
+		 ".I"[READ_ONCE(t->trc_ipi_to_cpu) > 0],
+		 ".i"[is_idle_task(t)],
+		 ".N"[cpu > 0 && tick_nohz_full_cpu(cpu)],
+		 t->trc_reader_nesting,
+		 " N"[!!t->trc_reader_special.b.need_qs],
+		 cpu);
+	sched_show_task(t);
+}
+
+/* List stalled IPIs for RCU tasks trace. */
+static void show_stalled_ipi_trace(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		if (per_cpu(trc_ipi_to_cpu, cpu))
+			pr_alert("\tIPI outstanding to CPU %d\n", cpu);
+}
+
+/* Do one scan of the holdout list. */
+static void check_all_holdout_tasks_trace(struct list_head *hop,
+					  bool needreport, bool *firstreport)
+{
+	struct task_struct *g, *t;
+
+	// Disable CPU hotplug across the holdout list scan.
+	cpus_read_lock();
+
+	list_for_each_entry_safe(t, g, hop, trc_holdout_list) {
+		// If safe and needed, try to check the current task.
+		if (READ_ONCE(t->trc_ipi_to_cpu) == -1 &&
+		    !READ_ONCE(t->trc_reader_checked))
+			trc_wait_for_one_reader(t, hop);
+
+		// If check succeeded, remove this task from the list.
+		if (READ_ONCE(t->trc_reader_checked))
+			trc_del_holdout(t);
+		else if (needreport)
+			show_stalled_task_trace(t, firstreport);
+	}
+
+	// Re-enable CPU hotplug now that the holdout list scan has completed.
+	cpus_read_unlock();
+
+	if (needreport) {
+		if (firstreport)
+			pr_err("INFO: rcu_tasks_trace detected stalls? (Late IPI?)\n");
+		show_stalled_ipi_trace();
+	}
+}
+
+/* Wait for grace period to complete and provide ordering. */
+static void rcu_tasks_trace_postgp(struct rcu_tasks *rtp)
+{
+	bool firstreport;
+	struct task_struct *g, *t;
+	LIST_HEAD(holdouts);
+	long ret;
+
+	// Remove the safety count.
+	smp_mb__before_atomic();  // Order vs. earlier atomics
+	atomic_dec(&trc_n_readers_need_end);
+	smp_mb__after_atomic();  // Order vs. later atomics
+
+	// Wait for readers.
+	set_tasks_gp_state(rtp, RTGS_WAIT_READERS);
+	for (;;) {
+		ret = wait_event_idle_exclusive_timeout(
+				trc_wait,
+				atomic_read(&trc_n_readers_need_end) == 0,
+				READ_ONCE(rcu_task_stall_timeout));
+		if (ret)
+			break;  // Count reached zero.
+		// Stall warning time, so make a list of the offenders.
+		rcu_read_lock();
+		for_each_process_thread(g, t)
+			if (READ_ONCE(t->trc_reader_special.b.need_qs))
+				trc_add_holdout(t, &holdouts);
+		rcu_read_unlock();
+		firstreport = true;
+		list_for_each_entry_safe(t, g, &holdouts, trc_holdout_list) {
+			if (READ_ONCE(t->trc_reader_special.b.need_qs))
+				show_stalled_task_trace(t, &firstreport);
+			trc_del_holdout(t); // Release task_struct reference.
+		}
+		if (firstreport)
+			pr_err("INFO: rcu_tasks_trace detected stalls? (Counter/taskslist mismatch?)\n");
+		show_stalled_ipi_trace();
+		pr_err("\t%d holdouts\n", atomic_read(&trc_n_readers_need_end));
+	}
+	smp_mb(); // Caller's code must be ordered after wakeup.
+		  // Pairs with pretty much every ordering primitive.
+}
+
+/* Report any needed quiescent state for this exiting task. */
+static void exit_tasks_rcu_finish_trace(struct task_struct *t)
+{
+	WRITE_ONCE(t->trc_reader_checked, true);
+	WARN_ON_ONCE(t->trc_reader_nesting);
+	WRITE_ONCE(t->trc_reader_nesting, 0);
+	if (WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs)))
+		rcu_read_unlock_trace_special(t, 0);
+}
+
+/**
+ * call_rcu_tasks_trace() - Queue a callback trace task-based grace period
+ * @rhp: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all currently executing RCU
+ * read-side critical sections have completed. call_rcu_tasks_trace()
+ * assumes that the read-side critical sections end at context switch,
+ * cond_resched_rcu_qs(), or transition to usermode execution.  As such,
+ * there are no read-side primitives analogous to rcu_read_lock() and
+ * rcu_read_unlock() because this primitive is intended to determine
+ * that all tasks have passed through a safe state, not so much for
+ * data-strcuture synchronization.
+ *
+ * See the description of call_rcu() for more detailed information on
+ * memory ordering guarantees.
+ */
+void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func)
+{
+	call_rcu_tasks_generic(rhp, func, &rcu_tasks_trace);
+}
+EXPORT_SYMBOL_GPL(call_rcu_tasks_trace);
+
+/**
+ * synchronize_rcu_tasks_trace - wait for a trace rcu-tasks grace period
+ *
+ * Control will return to the caller some time after a trace rcu-tasks
+ * grace period has elapsed, in other words after all currently executing
+ * rcu-tasks read-side critical sections have elapsed.  These read-side
+ * critical sections are delimited by calls to rcu_read_lock_trace()
+ * and rcu_read_unlock_trace().
+ *
+ * This is a very specialized primitive, intended only for a few uses in
+ * tracing and other situations requiring manipulation of function preambles
+ * and profiling hooks.  The synchronize_rcu_tasks_trace() function is not
+ * (yet) intended for heavy use from multiple CPUs.
+ *
+ * See the description of synchronize_rcu() for more detailed information
+ * on memory ordering guarantees.
+ */
+void synchronize_rcu_tasks_trace(void)
+{
+	RCU_LOCKDEP_WARN(lock_is_held(&rcu_trace_lock_map), "Illegal synchronize_rcu_tasks_trace() in RCU Tasks Trace read-side critical section");
+	synchronize_rcu_tasks_generic(&rcu_tasks_trace);
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu_tasks_trace);
+
+/**
+ * rcu_barrier_tasks_trace - Wait for in-flight call_rcu_tasks_trace() callbacks.
+ *
+ * Although the current implementation is guaranteed to wait, it is not
+ * obligated to, for example, if there are no pending callbacks.
+ */
+void rcu_barrier_tasks_trace(void)
+{
+	/* There is only one callback queue, so this is easy.  ;-) */
+	synchronize_rcu_tasks_trace();
+}
+EXPORT_SYMBOL_GPL(rcu_barrier_tasks_trace);
+
+static int __init rcu_spawn_tasks_trace_kthread(void)
+{
+	if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB)) {
+		rcu_tasks_trace.gp_sleep = HZ / 10;
+		rcu_tasks_trace.init_fract = 10;
+	} else {
+		rcu_tasks_trace.gp_sleep = HZ / 200;
+		if (rcu_tasks_trace.gp_sleep <= 0)
+			rcu_tasks_trace.gp_sleep = 1;
+		rcu_tasks_trace.init_fract = HZ / 5;
+		if (rcu_tasks_trace.init_fract <= 0)
+			rcu_tasks_trace.init_fract = 1;
+	}
+	rcu_tasks_trace.pregp_func = rcu_tasks_trace_pregp_step;
+	rcu_tasks_trace.pertask_func = rcu_tasks_trace_pertask;
+	rcu_tasks_trace.postscan_func = rcu_tasks_trace_postscan;
+	rcu_tasks_trace.holdouts_func = check_all_holdout_tasks_trace;
+	rcu_tasks_trace.postgp_func = rcu_tasks_trace_postgp;
+	rcu_spawn_tasks_kthread_generic(&rcu_tasks_trace);
+	return 0;
+}
+
+#ifndef CONFIG_TINY_RCU
+static void show_rcu_tasks_trace_gp_kthread(void)
+{
+	char buf[64];
+
+	sprintf(buf, "N%d h:%lu/%lu/%lu", atomic_read(&trc_n_readers_need_end),
+		data_race(n_heavy_reader_ofl_updates),
+		data_race(n_heavy_reader_updates),
+		data_race(n_heavy_reader_attempts));
+	show_rcu_tasks_generic_gp_kthread(&rcu_tasks_trace, buf);
+}
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+#else /* #ifdef CONFIG_TASKS_TRACE_RCU */
+static void exit_tasks_rcu_finish_trace(struct task_struct *t) { }
+static inline void show_rcu_tasks_trace_gp_kthread(void) {}
+#endif /* #else #ifdef CONFIG_TASKS_TRACE_RCU */
+
+#ifndef CONFIG_TINY_RCU
+void show_rcu_tasks_gp_kthreads(void)
+{
+	show_rcu_tasks_classic_gp_kthread();
+	show_rcu_tasks_rude_gp_kthread();
+	show_rcu_tasks_trace_gp_kthread();
+}
+#endif /* #ifndef CONFIG_TINY_RCU */
+
+void __init rcu_init_tasks_generic(void)
+{
+#ifdef CONFIG_TASKS_RCU
+	rcu_spawn_tasks_kthread();
+#endif
+
+#ifdef CONFIG_TASKS_RUDE_RCU
+	rcu_spawn_tasks_rude_kthread();
+#endif
+
+#ifdef CONFIG_TASKS_TRACE_RCU
+	rcu_spawn_tasks_trace_kthread();
+#endif
+}
+
+#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
+static inline void rcu_tasks_bootup_oddness(void) {}
+void show_rcu_tasks_gp_kthreads(void) {}
+#endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 477b4eb..aa897c3 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -22,6 +22,8 @@
 #include <linux/time.h>
 #include <linux/cpu.h>
 #include <linux/prefetch.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
 
 #include "rcu.h"
 
@@ -73,6 +75,31 @@
 	}
 }
 
+/*
+ * Reclaim the specified callback, either by invoking it for non-kfree cases or
+ * freeing it directly (for kfree). Return true if kfreeing, false otherwise.
+ */
+static inline bool rcu_reclaim_tiny(struct rcu_head *head)
+{
+	rcu_callback_t f;
+	unsigned long offset = (unsigned long)head->func;
+
+	rcu_lock_acquire(&rcu_callback_map);
+	if (__is_kvfree_rcu_offset(offset)) {
+		trace_rcu_invoke_kvfree_callback("", head, offset);
+		kvfree((void *)head - offset);
+		rcu_lock_release(&rcu_callback_map);
+		return true;
+	}
+
+	trace_rcu_invoke_callback("", head);
+	f = head->func;
+	WRITE_ONCE(head->func, (rcu_callback_t)0L);
+	f(head);
+	rcu_lock_release(&rcu_callback_map);
+	return false;
+}
+
 /* Invoke the RCU callbacks whose grace period has elapsed.  */
 static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
 {
@@ -100,7 +127,7 @@
 		prefetch(next);
 		debug_rcu_head_unqueue(list);
 		local_bh_disable();
-		__rcu_reclaim("", list);
+		rcu_reclaim_tiny(list);
 		local_bh_enable();
 		list = next;
 	}
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 11ae274..844c358 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1,12 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Read-Copy Update mechanism for mutual exclusion
+ * Read-Copy Update mechanism for mutual exclusion (tree-based version)
  *
  * Copyright IBM Corporation, 2008
  *
  * Authors: Dipankar Sarma <dipankar@in.ibm.com>
  *	    Manfred Spraul <manfred@colorfullife.com>
- *	    Paul E. McKenney <paulmck@linux.ibm.com> Hierarchical version
+ *	    Paul E. McKenney <paulmck@linux.ibm.com>
  *
  * Based on the original work by Paul McKenney <paulmck@linux.ibm.com>
  * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
@@ -43,7 +43,6 @@
 #include <uapi/linux/sched/types.h>
 #include <linux/prefetch.h>
 #include <linux/delay.h>
-#include <linux/stop_machine.h>
 #include <linux/random.h>
 #include <linux/trace_events.h>
 #include <linux/suspend.h>
@@ -55,8 +54,12 @@
 #include <linux/oom.h>
 #include <linux/smpboot.h>
 #include <linux/jiffies.h>
+#include <linux/slab.h>
 #include <linux/sched/isolation.h>
 #include <linux/sched/clock.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/kasan.h>
 #include "../time/tick-internal.h"
 
 #include "tree.h"
@@ -75,16 +78,13 @@
  */
 #define RCU_DYNTICK_CTRL_MASK 0x1
 #define RCU_DYNTICK_CTRL_CTR  (RCU_DYNTICK_CTRL_MASK + 1)
-#ifndef rcu_eqs_special_exit
-#define rcu_eqs_special_exit() do { } while (0)
-#endif
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, rcu_data) = {
 	.dynticks_nesting = 1,
 	.dynticks_nmi_nesting = DYNTICK_IRQ_NONIDLE,
 	.dynticks = ATOMIC_INIT(RCU_DYNTICK_CTRL_CTR),
 };
-struct rcu_state rcu_state = {
+static struct rcu_state rcu_state = {
 	.level = { &rcu_state.node[0] },
 	.gp_state = RCU_GP_IDLE,
 	.gp_seq = (0UL - 300UL) << RCU_SEQ_CTR_SHIFT,
@@ -100,7 +100,7 @@
 static bool dump_tree;
 module_param(dump_tree, bool, 0444);
 /* By default, use RCU_SOFTIRQ instead of rcuc kthreads. */
-static bool use_softirq = 1;
+static bool use_softirq = true;
 module_param(use_softirq, bool, 0444);
 /* Control rcu_node-tree auto-balancing at boot time. */
 static bool rcu_fanout_exact;
@@ -150,6 +150,7 @@
 static void invoke_rcu_core(void);
 static void rcu_report_exp_rdp(struct rcu_data *rdp);
 static void sync_sched_exp_online_cleanup(int cpu);
+static void check_cb_ovld_locked(struct rcu_data *rdp, struct rcu_node *rnp);
 
 /* rcuc/rcub kthread realtime priority */
 static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0;
@@ -164,6 +165,21 @@
 static int gp_cleanup_delay;
 module_param(gp_cleanup_delay, int, 0444);
 
+// Add delay to rcu_read_unlock() for strict grace periods.
+static int rcu_unlock_delay;
+#ifdef CONFIG_RCU_STRICT_GRACE_PERIOD
+module_param(rcu_unlock_delay, int, 0444);
+#endif
+
+/*
+ * This rcu parameter is runtime-read-only. It reflects
+ * a minimum allowed number of objects which can be cached
+ * per-CPU. Object size is equal to one page. This value
+ * can be changed at boot time.
+ */
+static int rcu_min_cached_objs = 5;
+module_param(rcu_min_cached_objs, int, 0444);
+
 /* Retrieve RCU kthreads priority for rcutorture */
 int rcu_get_gp_kthreads_prio(void)
 {
@@ -188,7 +204,7 @@
  * held, but the bit corresponding to the current CPU will be stable
  * in most contexts.
  */
-unsigned long rcu_rnp_online_cpus(struct rcu_node *rnp)
+static unsigned long rcu_rnp_online_cpus(struct rcu_node *rnp)
 {
 	return READ_ONCE(rnp->qsmaskinitnext);
 }
@@ -224,9 +240,11 @@
 
 /*
  * Record entry into an extended quiescent state.  This is only to be
- * called when not already in an extended quiescent state.
+ * called when not already in an extended quiescent state, that is,
+ * RCU is watching prior to the call to this function and is no longer
+ * watching upon return.
  */
-static void rcu_dynticks_eqs_enter(void)
+static noinstr void rcu_dynticks_eqs_enter(void)
 {
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 	int seq;
@@ -236,8 +254,9 @@
 	 * critical sections, and we also must force ordering with the
 	 * next idle sojourn.
 	 */
-	seq = atomic_add_return(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks);
-	/* Better be in an extended quiescent state! */
+	rcu_dynticks_task_trace_enter();  // Before ->dynticks update!
+	seq = arch_atomic_add_return(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks);
+	// RCU is no longer watching.  Better be in extended quiescent state!
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
 		     (seq & RCU_DYNTICK_CTRL_CTR));
 	/* Better not have special action (TLB flush) pending! */
@@ -247,9 +266,10 @@
 
 /*
  * Record exit from an extended quiescent state.  This is only to be
- * called from an extended quiescent state.
+ * called from an extended quiescent state, that is, RCU is not watching
+ * prior to the call to this function and is watching upon return.
  */
-static void rcu_dynticks_eqs_exit(void)
+static noinstr void rcu_dynticks_eqs_exit(void)
 {
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 	int seq;
@@ -259,14 +279,14 @@
 	 * and we also must force ordering with the next RCU read-side
 	 * critical section.
 	 */
-	seq = atomic_add_return(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks);
+	seq = arch_atomic_add_return(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks);
+	// RCU is now watching.  Better not be in an extended quiescent state!
+	rcu_dynticks_task_trace_exit();  // After ->dynticks update!
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
 		     !(seq & RCU_DYNTICK_CTRL_CTR));
 	if (seq & RCU_DYNTICK_CTRL_MASK) {
-		atomic_andnot(RCU_DYNTICK_CTRL_MASK, &rdp->dynticks);
+		arch_atomic_andnot(RCU_DYNTICK_CTRL_MASK, &rdp->dynticks);
 		smp_mb__after_atomic(); /* _exit after clearing mask. */
-		/* Prefer duplicate flushes to losing a flush. */
-		rcu_eqs_special_exit();
 	}
 }
 
@@ -294,18 +314,18 @@
  *
  * No ordering, as we are sampling CPU-local information.
  */
-bool rcu_dynticks_curr_cpu_in_eqs(void)
+static __always_inline bool rcu_dynticks_curr_cpu_in_eqs(void)
 {
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 
-	return !(atomic_read(&rdp->dynticks) & RCU_DYNTICK_CTRL_CTR);
+	return !(arch_atomic_read(&rdp->dynticks) & RCU_DYNTICK_CTRL_CTR);
 }
 
 /*
  * Snapshot the ->dynticks counter with full ordering so as to allow
  * stable comparison of this counter with past and future snapshots.
  */
-int rcu_dynticks_snap(struct rcu_data *rdp)
+static int rcu_dynticks_snap(struct rcu_data *rdp)
 {
 	int snap = atomic_add_return(0, &rdp->dynticks);
 
@@ -332,6 +352,28 @@
 }
 
 /*
+ * Return true if the referenced integer is zero while the specified
+ * CPU remains within a single extended quiescent state.
+ */
+bool rcu_dynticks_zero_in_eqs(int cpu, int *vp)
+{
+	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
+	int snap;
+
+	// If not quiescent, force back to earlier extended quiescent state.
+	snap = atomic_read(&rdp->dynticks) & ~(RCU_DYNTICK_CTRL_MASK |
+					       RCU_DYNTICK_CTRL_CTR);
+
+	smp_rmb(); // Order ->dynticks and *vp reads.
+	if (READ_ONCE(*vp))
+		return false;  // Non-zero, so report failure;
+	smp_rmb(); // Order *vp read and ->dynticks re-read.
+
+	// If still in the same extended quiescent state, we are good!
+	return snap == (atomic_read(&rdp->dynticks) & ~RCU_DYNTICK_CTRL_MASK);
+}
+
+/*
  * Set the special (bottom) bit of the specified CPU so that it
  * will take special action (such as flushing its TLB) on the
  * next exit from an extended quiescent state.  Returns true if
@@ -342,14 +384,17 @@
 {
 	int old;
 	int new;
+	int new_old;
 	struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
 
+	new_old = atomic_read(&rdp->dynticks);
 	do {
-		old = atomic_read(&rdp->dynticks);
+		old = new_old;
 		if (old & RCU_DYNTICK_CTRL_CTR)
 			return false;
 		new = old | RCU_DYNTICK_CTRL_MASK;
-	} while (atomic_cmpxchg(&rdp->dynticks, old, new) != old);
+		new_old = atomic_cmpxchg(&rdp->dynticks, old, new);
+	} while (new_old != old);
 	return true;
 }
 
@@ -364,7 +409,7 @@
  *
  * The caller must have disabled interrupts and must not be idle.
  */
-static void __maybe_unused rcu_momentary_dyntick_idle(void)
+notrace void rcu_momentary_dyntick_idle(void)
 {
 	int special;
 
@@ -375,18 +420,26 @@
 	WARN_ON_ONCE(!(special & RCU_DYNTICK_CTRL_CTR));
 	rcu_preempt_deferred_qs(current);
 }
+EXPORT_SYMBOL_GPL(rcu_momentary_dyntick_idle);
 
 /**
- * rcu_is_cpu_rrupt_from_idle - see if interrupted from idle
+ * rcu_is_cpu_rrupt_from_idle - see if 'interrupted' from idle
  *
  * If the current CPU is idle and running at a first-level (not nested)
- * interrupt from idle, return true.  The caller must have at least
- * disabled preemption.
+ * interrupt, or directly, from idle, return true.
+ *
+ * The caller must have at least disabled IRQs.
  */
 static int rcu_is_cpu_rrupt_from_idle(void)
 {
-	/* Called only from within the scheduling-clock interrupt */
-	lockdep_assert_in_irq();
+	long nesting;
+
+	/*
+	 * Usually called from the tick; but also used from smp_function_call()
+	 * for expedited grace periods. This latter can result in running from
+	 * the idle task, instead of an actual IPI.
+	 */
+	lockdep_assert_irqs_disabled();
 
 	/* Check for counter underflows */
 	RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nesting) < 0,
@@ -395,26 +448,38 @@
 			 "RCU dynticks_nmi_nesting counter underflow/zero!");
 
 	/* Are we at first interrupt nesting level? */
-	if (__this_cpu_read(rcu_data.dynticks_nmi_nesting) != 1)
+	nesting = __this_cpu_read(rcu_data.dynticks_nmi_nesting);
+	if (nesting > 1)
 		return false;
 
+	/*
+	 * If we're not in an interrupt, we must be in the idle task!
+	 */
+	WARN_ON_ONCE(!nesting && !is_idle_task(current));
+
 	/* Does CPU appear to be idle from an RCU standpoint? */
 	return __this_cpu_read(rcu_data.dynticks_nesting) == 0;
 }
 
-#define DEFAULT_RCU_BLIMIT 10     /* Maximum callbacks per rcu_do_batch ... */
-#define DEFAULT_MAX_RCU_BLIMIT 10000 /* ... even during callback flood. */
+#define DEFAULT_RCU_BLIMIT (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) ? 1000 : 10)
+				// Maximum callbacks per rcu_do_batch ...
+#define DEFAULT_MAX_RCU_BLIMIT 10000 // ... even during callback flood.
 static long blimit = DEFAULT_RCU_BLIMIT;
-#define DEFAULT_RCU_QHIMARK 10000 /* If this many pending, ignore blimit. */
+#define DEFAULT_RCU_QHIMARK 10000 // If this many pending, ignore blimit.
 static long qhimark = DEFAULT_RCU_QHIMARK;
-#define DEFAULT_RCU_QLOMARK 100   /* Once only this many pending, use blimit. */
+#define DEFAULT_RCU_QLOMARK 100   // Once only this many pending, use blimit.
 static long qlowmark = DEFAULT_RCU_QLOMARK;
+#define DEFAULT_RCU_QOVLD_MULT 2
+#define DEFAULT_RCU_QOVLD (DEFAULT_RCU_QOVLD_MULT * DEFAULT_RCU_QHIMARK)
+static long qovld = DEFAULT_RCU_QOVLD; // If this many pending, hammer QS.
+static long qovld_calc = -1;	  // No pre-initialization lock acquisitions!
 
 module_param(blimit, long, 0444);
 module_param(qhimark, long, 0444);
 module_param(qlowmark, long, 0444);
+module_param(qovld, long, 0444);
 
-static ulong jiffies_till_first_fqs = ULONG_MAX;
+static ulong jiffies_till_first_fqs = IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) ? 0 : ULONG_MAX;
 static ulong jiffies_till_next_fqs = ULONG_MAX;
 static bool rcu_kick_kthreads;
 static int rcu_divisor = 7;
@@ -496,7 +561,7 @@
 module_param(rcu_kick_kthreads, bool, 0644);
 
 static void force_qs_rnp(int (*f)(struct rcu_data *rdp));
-static int rcu_pending(void);
+static int rcu_pending(int user);
 
 /*
  * Return the number of RCU GPs completed thus far for debug & stats.
@@ -528,16 +593,6 @@
 }
 
 /*
- * Convert a ->gp_state value to a character string.
- */
-static const char *gp_state_getname(short gs)
-{
-	if (gs < 0 || gs >= ARRAY_SIZE(gp_state_names))
-		return "???";
-	return gp_state_names[gs];
-}
-
-/*
  * Send along grace-period-related data for rcutorture diagnostics.
  */
 void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
@@ -562,7 +617,7 @@
  * the possibility of usermode upcalls having messed up our count
  * of interrupt nesting level during the prior busy period.
  */
-static void rcu_eqs_enter(bool user)
+static noinstr void rcu_eqs_enter(bool user)
 {
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 
@@ -571,18 +626,27 @@
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
 		     rdp->dynticks_nesting == 0);
 	if (rdp->dynticks_nesting != 1) {
+		// RCU will still be watching, so just do accounting and leave.
 		rdp->dynticks_nesting--;
 		return;
 	}
 
 	lockdep_assert_irqs_disabled();
+	instrumentation_begin();
 	trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, atomic_read(&rdp->dynticks));
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
 	rdp = this_cpu_ptr(&rcu_data);
 	rcu_prepare_for_idle();
 	rcu_preempt_deferred_qs(current);
+
+	// instrumentation for the noinstr rcu_dynticks_eqs_enter()
+	instrument_atomic_write(&rdp->dynticks, sizeof(rdp->dynticks));
+
+	instrumentation_end();
 	WRITE_ONCE(rdp->dynticks_nesting, 0); /* Avoid irq-access tearing. */
+	// RCU is watching here ...
 	rcu_dynticks_eqs_enter();
+	// ... but is no longer watching here.
 	rcu_dynticks_task_enter();
 }
 
@@ -602,6 +666,7 @@
 	lockdep_assert_irqs_disabled();
 	rcu_eqs_enter(false);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_enter);
 
 #ifdef CONFIG_NO_HZ_FULL
 /**
@@ -615,7 +680,7 @@
  * If you add or remove a call to rcu_user_enter(), be sure to test with
  * CONFIG_RCU_EQS_DEBUG=y.
  */
-void rcu_user_enter(void)
+noinstr void rcu_user_enter(void)
 {
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 
@@ -629,19 +694,22 @@
 }
 #endif /* CONFIG_NO_HZ_FULL */
 
-/*
+/**
+ * rcu_nmi_exit - inform RCU of exit from NMI context
+ *
  * If we are returning from the outermost NMI handler that interrupted an
  * RCU-idle period, update rdp->dynticks and rdp->dynticks_nmi_nesting
  * to let the RCU grace-period handling know that the CPU is back to
  * being RCU-idle.
  *
- * If you add or remove a call to rcu_nmi_exit_common(), be sure to test
+ * If you add or remove a call to rcu_nmi_exit(), be sure to test
  * with CONFIG_RCU_EQS_DEBUG=y.
  */
-static __always_inline void rcu_nmi_exit_common(bool irq)
+noinstr void rcu_nmi_exit(void)
 {
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 
+	instrumentation_begin();
 	/*
 	 * Check for ->dynticks_nmi_nesting underflow and bad ->dynticks.
 	 * (We are exiting an NMI handler, so RCU better be paying attention
@@ -659,6 +727,7 @@
 				  atomic_read(&rdp->dynticks));
 		WRITE_ONCE(rdp->dynticks_nmi_nesting, /* No store tearing. */
 			   rdp->dynticks_nmi_nesting - 2);
+		instrumentation_end();
 		return;
 	}
 
@@ -666,27 +735,22 @@
 	trace_rcu_dyntick(TPS("Startirq"), rdp->dynticks_nmi_nesting, 0, atomic_read(&rdp->dynticks));
 	WRITE_ONCE(rdp->dynticks_nmi_nesting, 0); /* Avoid store tearing. */
 
-	if (irq)
+	if (!in_nmi())
 		rcu_prepare_for_idle();
 
+	// instrumentation for the noinstr rcu_dynticks_eqs_enter()
+	instrument_atomic_write(&rdp->dynticks, sizeof(rdp->dynticks));
+	instrumentation_end();
+
+	// RCU is watching here ...
 	rcu_dynticks_eqs_enter();
+	// ... but is no longer watching here.
 
-	if (irq)
+	if (!in_nmi())
 		rcu_dynticks_task_enter();
 }
 
 /**
- * rcu_nmi_exit - inform RCU of exit from NMI context
- *
- * If you add or remove a call to rcu_nmi_exit(), be sure to test
- * with CONFIG_RCU_EQS_DEBUG=y.
- */
-void rcu_nmi_exit(void)
-{
-	rcu_nmi_exit_common(false);
-}
-
-/**
  * rcu_irq_exit - inform RCU that current CPU is exiting irq towards idle
  *
  * Exit from an interrupt handler, which might possibly result in entering
@@ -705,12 +769,52 @@
  * If you add or remove a call to rcu_irq_exit(), be sure to test with
  * CONFIG_RCU_EQS_DEBUG=y.
  */
-void rcu_irq_exit(void)
+void noinstr rcu_irq_exit(void)
 {
 	lockdep_assert_irqs_disabled();
-	rcu_nmi_exit_common(true);
+	rcu_nmi_exit();
 }
 
+/**
+ * rcu_irq_exit_preempt - Inform RCU that current CPU is exiting irq
+ *			  towards in kernel preemption
+ *
+ * Same as rcu_irq_exit() but has a sanity check that scheduling is safe
+ * from RCU point of view. Invoked from return from interrupt before kernel
+ * preemption.
+ */
+void rcu_irq_exit_preempt(void)
+{
+	lockdep_assert_irqs_disabled();
+	rcu_nmi_exit();
+
+	RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nesting) <= 0,
+			 "RCU dynticks_nesting counter underflow/zero!");
+	RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nmi_nesting) !=
+			 DYNTICK_IRQ_NONIDLE,
+			 "Bad RCU  dynticks_nmi_nesting counter\n");
+	RCU_LOCKDEP_WARN(rcu_dynticks_curr_cpu_in_eqs(),
+			 "RCU in extended quiescent state!");
+}
+
+#ifdef CONFIG_PROVE_RCU
+/**
+ * rcu_irq_exit_check_preempt - Validate that scheduling is possible
+ */
+void rcu_irq_exit_check_preempt(void)
+{
+	lockdep_assert_irqs_disabled();
+
+	RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nesting) <= 0,
+			 "RCU dynticks_nesting counter underflow/zero!");
+	RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nmi_nesting) !=
+			 DYNTICK_IRQ_NONIDLE,
+			 "Bad RCU  dynticks_nmi_nesting counter\n");
+	RCU_LOCKDEP_WARN(rcu_dynticks_curr_cpu_in_eqs(),
+			 "RCU in extended quiescent state!");
+}
+#endif /* #ifdef CONFIG_PROVE_RCU */
+
 /*
  * Wrapper for rcu_irq_exit() where interrupts are enabled.
  *
@@ -734,7 +838,7 @@
  * allow for the possibility of usermode upcalls messing up our count of
  * interrupt nesting level during the busy period that is just now starting.
  */
-static void rcu_eqs_exit(bool user)
+static void noinstr rcu_eqs_exit(bool user)
 {
 	struct rcu_data *rdp;
 	long oldval;
@@ -744,17 +848,26 @@
 	oldval = rdp->dynticks_nesting;
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && oldval < 0);
 	if (oldval) {
+		// RCU was already watching, so just do accounting and leave.
 		rdp->dynticks_nesting++;
 		return;
 	}
 	rcu_dynticks_task_exit();
+	// RCU is not watching here ...
 	rcu_dynticks_eqs_exit();
+	// ... but is watching here.
+	instrumentation_begin();
+
+	// instrumentation for the noinstr rcu_dynticks_eqs_exit()
+	instrument_atomic_write(&rdp->dynticks, sizeof(rdp->dynticks));
+
 	rcu_cleanup_after_idle();
 	trace_rcu_dyntick(TPS("End"), rdp->dynticks_nesting, 1, atomic_read(&rdp->dynticks));
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
 	WRITE_ONCE(rdp->dynticks_nesting, 1);
 	WARN_ON_ONCE(rdp->dynticks_nmi_nesting);
 	WRITE_ONCE(rdp->dynticks_nmi_nesting, DYNTICK_IRQ_NONIDLE);
+	instrumentation_end();
 }
 
 /**
@@ -774,6 +887,7 @@
 	rcu_eqs_exit(false);
 	local_irq_restore(flags);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_exit);
 
 #ifdef CONFIG_NO_HZ_FULL
 /**
@@ -785,15 +899,75 @@
  * If you add or remove a call to rcu_user_exit(), be sure to test with
  * CONFIG_RCU_EQS_DEBUG=y.
  */
-void rcu_user_exit(void)
+void noinstr rcu_user_exit(void)
 {
 	rcu_eqs_exit(1);
 }
+
+/**
+ * __rcu_irq_enter_check_tick - Enable scheduler tick on CPU if RCU needs it.
+ *
+ * The scheduler tick is not normally enabled when CPUs enter the kernel
+ * from nohz_full userspace execution.  After all, nohz_full userspace
+ * execution is an RCU quiescent state and the time executing in the kernel
+ * is quite short.  Except of course when it isn't.  And it is not hard to
+ * cause a large system to spend tens of seconds or even minutes looping
+ * in the kernel, which can cause a number of problems, include RCU CPU
+ * stall warnings.
+ *
+ * Therefore, if a nohz_full CPU fails to report a quiescent state
+ * in a timely manner, the RCU grace-period kthread sets that CPU's
+ * ->rcu_urgent_qs flag with the expectation that the next interrupt or
+ * exception will invoke this function, which will turn on the scheduler
+ * tick, which will enable RCU to detect that CPU's quiescent states,
+ * for example, due to cond_resched() calls in CONFIG_PREEMPT=n kernels.
+ * The tick will be disabled once a quiescent state is reported for
+ * this CPU.
+ *
+ * Of course, in carefully tuned systems, there might never be an
+ * interrupt or exception.  In that case, the RCU grace-period kthread
+ * will eventually cause one to happen.  However, in less carefully
+ * controlled environments, this function allows RCU to get what it
+ * needs without creating otherwise useless interruptions.
+ */
+void __rcu_irq_enter_check_tick(void)
+{
+	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
+
+	// If we're here from NMI there's nothing to do.
+	if (in_nmi())
+		return;
+
+	RCU_LOCKDEP_WARN(rcu_dynticks_curr_cpu_in_eqs(),
+			 "Illegal rcu_irq_enter_check_tick() from extended quiescent state");
+
+	if (!tick_nohz_full_cpu(rdp->cpu) ||
+	    !READ_ONCE(rdp->rcu_urgent_qs) ||
+	    READ_ONCE(rdp->rcu_forced_tick)) {
+		// RCU doesn't need nohz_full help from this CPU, or it is
+		// already getting that help.
+		return;
+	}
+
+	// We get here only when not in an extended quiescent state and
+	// from interrupts (as opposed to NMIs).  Therefore, (1) RCU is
+	// already watching and (2) The fact that we are in an interrupt
+	// handler and that the rcu_node lock is an irq-disabled lock
+	// prevents self-deadlock.  So we can safely recheck under the lock.
+	// Note that the nohz_full state currently cannot change.
+	raw_spin_lock_rcu_node(rdp->mynode);
+	if (rdp->rcu_urgent_qs && !rdp->rcu_forced_tick) {
+		// A nohz_full CPU is in the kernel and RCU needs a
+		// quiescent state.  Turn on the tick!
+		WRITE_ONCE(rdp->rcu_forced_tick, true);
+		tick_dep_set_cpu(rdp->cpu, TICK_DEP_BIT_RCU);
+	}
+	raw_spin_unlock_rcu_node(rdp->mynode);
+}
 #endif /* CONFIG_NO_HZ_FULL */
 
 /**
- * rcu_nmi_enter_common - inform RCU of entry to NMI context
- * @irq: Is this call from rcu_irq_enter?
+ * rcu_nmi_enter - inform RCU of entry to NMI context
  *
  * If the CPU was idle from RCU's viewpoint, update rdp->dynticks and
  * rdp->dynticks_nmi_nesting to let the RCU grace-period handling know
@@ -801,13 +975,13 @@
  * long as the nesting level does not overflow an int.  (You will probably
  * run out of stack space first.)
  *
- * If you add or remove a call to rcu_nmi_enter_common(), be sure to test
+ * If you add or remove a call to rcu_nmi_enter(), be sure to test
  * with CONFIG_RCU_EQS_DEBUG=y.
  */
-static __always_inline void rcu_nmi_enter_common(bool irq)
+noinstr void rcu_nmi_enter(void)
 {
-	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 	long incby = 2;
+	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 
 	/* Complain about underflow. */
 	WARN_ON_ONCE(rdp->dynticks_nmi_nesting < 0);
@@ -822,34 +996,43 @@
 	 */
 	if (rcu_dynticks_curr_cpu_in_eqs()) {
 
-		if (irq)
+		if (!in_nmi())
 			rcu_dynticks_task_exit();
 
+		// RCU is not watching here ...
 		rcu_dynticks_eqs_exit();
+		// ... but is watching here.
 
-		if (irq)
+		if (!in_nmi()) {
+			instrumentation_begin();
 			rcu_cleanup_after_idle();
+			instrumentation_end();
+		}
+
+		instrumentation_begin();
+		// instrumentation for the noinstr rcu_dynticks_curr_cpu_in_eqs()
+		instrument_atomic_read(&rdp->dynticks, sizeof(rdp->dynticks));
+		// instrumentation for the noinstr rcu_dynticks_eqs_exit()
+		instrument_atomic_write(&rdp->dynticks, sizeof(rdp->dynticks));
 
 		incby = 1;
+	} else if (!in_nmi()) {
+		instrumentation_begin();
+		rcu_irq_enter_check_tick();
+	} else  {
+		instrumentation_begin();
 	}
+
 	trace_rcu_dyntick(incby == 1 ? TPS("Endirq") : TPS("++="),
 			  rdp->dynticks_nmi_nesting,
 			  rdp->dynticks_nmi_nesting + incby, atomic_read(&rdp->dynticks));
+	instrumentation_end();
 	WRITE_ONCE(rdp->dynticks_nmi_nesting, /* Prevent store tearing. */
 		   rdp->dynticks_nmi_nesting + incby);
 	barrier();
 }
 
 /**
- * rcu_nmi_enter - inform RCU of entry to NMI context
- */
-void rcu_nmi_enter(void)
-{
-	rcu_nmi_enter_common(false);
-}
-NOKPROBE_SYMBOL(rcu_nmi_enter);
-
-/**
  * rcu_irq_enter - inform RCU that current CPU is entering irq away from idle
  *
  * Enter an interrupt handler, which might possibly result in exiting
@@ -871,10 +1054,10 @@
  * If you add or remove a call to rcu_irq_enter(), be sure to test with
  * CONFIG_RCU_EQS_DEBUG=y.
  */
-void rcu_irq_enter(void)
+noinstr void rcu_irq_enter(void)
 {
 	lockdep_assert_irqs_disabled();
-	rcu_nmi_enter_common(true);
+	rcu_nmi_enter();
 }
 
 /*
@@ -892,6 +1075,22 @@
 	local_irq_restore(flags);
 }
 
+/*
+ * If any sort of urgency was applied to the current CPU (for example,
+ * the scheduler-clock interrupt was enabled on a nohz_full CPU) in order
+ * to get to a quiescent state, disable it.
+ */
+static void rcu_disable_urgency_upon_qs(struct rcu_data *rdp)
+{
+	raw_lockdep_assert_held_rcu_node(rdp->mynode);
+	WRITE_ONCE(rdp->rcu_urgent_qs, false);
+	WRITE_ONCE(rdp->rcu_need_heavy_qs, false);
+	if (tick_nohz_full_cpu(rdp->cpu) && rdp->rcu_forced_tick) {
+		tick_dep_clear_cpu(rdp->cpu, TICK_DEP_BIT_RCU);
+		WRITE_ONCE(rdp->rcu_forced_tick, false);
+	}
+}
+
 /**
  * rcu_is_watching - see if RCU thinks that the current CPU is not idle
  *
@@ -899,8 +1098,11 @@
  * CPU can safely enter RCU read-side critical sections.  In other words,
  * if the current CPU is not in its idle loop or is in an interrupt or
  * NMI handler, return true.
+ *
+ * Make notrace because it can be called by the internal functions of
+ * ftrace, and making this notrace removes unnecessary recursion calls.
  */
-bool notrace rcu_is_watching(void)
+notrace bool rcu_is_watching(void)
 {
 	bool ret;
 
@@ -952,12 +1154,12 @@
 
 	if (in_nmi() || !rcu_scheduler_fully_active)
 		return true;
-	preempt_disable();
+	preempt_disable_notrace();
 	rdp = this_cpu_ptr(&rcu_data);
 	rnp = rdp->mynode;
 	if (rdp->grpmask & rcu_rnp_online_cpus(rnp))
 		ret = true;
-	preempt_enable();
+	preempt_enable_notrace();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(rcu_lockdep_current_cpu_online);
@@ -1024,13 +1226,28 @@
 		return 1;
 	}
 
-	/* If waiting too long on an offline CPU, complain. */
-	if (!(rdp->grpmask & rcu_rnp_online_cpus(rnp)) &&
-	    time_after(jiffies, rcu_state.gp_start + HZ)) {
+	/*
+	 * Complain if a CPU that is considered to be offline from RCU's
+	 * perspective has not yet reported a quiescent state.  After all,
+	 * the offline CPU should have reported a quiescent state during
+	 * the CPU-offline process, or, failing that, by rcu_gp_init()
+	 * if it ran concurrently with either the CPU going offline or the
+	 * last task on a leaf rcu_node structure exiting its RCU read-side
+	 * critical section while all CPUs corresponding to that structure
+	 * are offline.  This added warning detects bugs in any of these
+	 * code paths.
+	 *
+	 * The rcu_node structure's ->lock is held here, which excludes
+	 * the relevant portions the CPU-hotplug code, the grace-period
+	 * initialization code, and the rcu_read_unlock() code paths.
+	 *
+	 * For more detail, please refer to the "Hotplug CPU" section
+	 * of RCU's Requirements documentation.
+	 */
+	if (WARN_ON_ONCE(!(rdp->grpmask & rcu_rnp_online_cpus(rnp)))) {
 		bool onl;
 		struct rcu_node *rnp1;
 
-		WARN_ON(1);  /* Offline CPUs are supposed to report QS! */
 		pr_info("%s: grp: %d-%d level: %d ->gp_seq %ld ->completedqs %ld\n",
 			__func__, rnp->grplo, rnp->grphi, rnp->level,
 			(long)rnp->gp_seq, (long)rnp->completedqs);
@@ -1061,7 +1278,8 @@
 	rnhqp = &per_cpu(rcu_data.rcu_need_heavy_qs, rdp->cpu);
 	if (!READ_ONCE(*rnhqp) &&
 	    (time_after(jiffies, rcu_state.gp_start + jtsq * 2) ||
-	     time_after(jiffies, rcu_state.jiffies_resched))) {
+	     time_after(jiffies, rcu_state.jiffies_resched) ||
+	     rcu_state.cbovld)) {
 		WRITE_ONCE(*rnhqp, true);
 		/* Store rcu_need_heavy_qs before rcu_urgent_qs. */
 		smp_store_release(ruqp, true);
@@ -1078,8 +1296,9 @@
 	 * So hit them over the head with the resched_cpu() hammer!
 	 */
 	if (tick_nohz_full_cpu(rdp->cpu) &&
-		   time_after(jiffies,
-			      READ_ONCE(rdp->last_fqs_resched) + jtsq * 3)) {
+	    (time_after(jiffies, READ_ONCE(rdp->last_fqs_resched) + jtsq * 3) ||
+	     rcu_state.cbovld)) {
+		WRITE_ONCE(*ruqp, true);
 		resched_cpu(rdp->cpu);
 		WRITE_ONCE(rdp->last_fqs_resched, jiffies);
 	}
@@ -1101,6 +1320,7 @@
 		    !rdp->rcu_iw_pending && rdp->rcu_iw_gp_seq != rnp->gp_seq &&
 		    (rnp->ffmask & rdp->grpmask)) {
 			init_irq_work(&rdp->rcu_iw, rcu_iw_handler);
+			atomic_set(&rdp->rcu_iw.flags, IRQ_WORK_HARD_IRQ);
 			rdp->rcu_iw_pending = true;
 			rdp->rcu_iw_gp_seq = rnp->gp_seq;
 			irq_work_queue_on(&rdp->rcu_iw, rdp->cpu);
@@ -1114,8 +1334,9 @@
 static void trace_rcu_this_gp(struct rcu_node *rnp, struct rcu_data *rdp,
 			      unsigned long gp_seq_req, const char *s)
 {
-	trace_rcu_future_grace_period(rcu_state.name, rnp->gp_seq, gp_seq_req,
-				      rnp->level, rnp->grplo, rnp->grphi, s);
+	trace_rcu_future_grace_period(rcu_state.name, READ_ONCE(rnp->gp_seq),
+				      gp_seq_req, rnp->level,
+				      rnp->grplo, rnp->grphi, s);
 }
 
 /*
@@ -1162,7 +1383,7 @@
 					  TPS("Prestarted"));
 			goto unlock_out;
 		}
-		rnp->gp_seq_needed = gp_seq_req;
+		WRITE_ONCE(rnp->gp_seq_needed, gp_seq_req);
 		if (rcu_seq_state(rcu_seq_current(&rnp->gp_seq))) {
 			/*
 			 * We just marked the leaf or internal node, and a
@@ -1187,18 +1408,18 @@
 	}
 	trace_rcu_this_gp(rnp, rdp, gp_seq_req, TPS("Startedroot"));
 	WRITE_ONCE(rcu_state.gp_flags, rcu_state.gp_flags | RCU_GP_FLAG_INIT);
-	rcu_state.gp_req_activity = jiffies;
-	if (!rcu_state.gp_kthread) {
+	WRITE_ONCE(rcu_state.gp_req_activity, jiffies);
+	if (!READ_ONCE(rcu_state.gp_kthread)) {
 		trace_rcu_this_gp(rnp, rdp, gp_seq_req, TPS("NoGPkthread"));
 		goto unlock_out;
 	}
-	trace_rcu_grace_period(rcu_state.name, READ_ONCE(rcu_state.gp_seq), TPS("newreq"));
+	trace_rcu_grace_period(rcu_state.name, data_race(rcu_state.gp_seq), TPS("newreq"));
 	ret = true;  /* Caller must wake GP kthread. */
 unlock_out:
 	/* Push furthest requested GP to leaf node and rcu_data structure. */
 	if (ULONG_CMP_LT(gp_seq_req, rnp->gp_seq_needed)) {
-		rnp_start->gp_seq_needed = rnp->gp_seq_needed;
-		rdp->gp_seq_needed = rnp->gp_seq_needed;
+		WRITE_ONCE(rnp_start->gp_seq_needed, rnp->gp_seq_needed);
+		WRITE_ONCE(rdp->gp_seq_needed, rnp->gp_seq_needed);
 	}
 	if (rnp != rnp_start)
 		raw_spin_unlock_rcu_node(rnp);
@@ -1223,12 +1444,13 @@
 }
 
 /*
- * Awaken the grace-period kthread.  Don't do a self-awaken (unless in
- * an interrupt or softirq handler), and don't bother awakening when there
- * is nothing for the grace-period kthread to do (as in several CPUs raced
- * to awaken, and we lost), and finally don't try to awaken a kthread that
- * has not yet been created.  If all those checks are passed, track some
- * debug information and awaken.
+ * Awaken the grace-period kthread.  Don't do a self-awaken (unless in an
+ * interrupt or softirq handler, in which case we just might immediately
+ * sleep upon return, resulting in a grace-period hang), and don't bother
+ * awakening when there is nothing for the grace-period kthread to do
+ * (as in several CPUs raced to awaken, we lost), and finally don't try
+ * to awaken a kthread that has not yet been created.  If all those checks
+ * are passed, track some debug information and awaken.
  *
  * So why do the self-wakeup when in an interrupt or softirq handler
  * in the grace-period kthread's context?  Because the kthread might have
@@ -1238,10 +1460,10 @@
  */
 static void rcu_gp_kthread_wake(void)
 {
-	if ((current == rcu_state.gp_kthread &&
-	     !in_irq() && !in_serving_softirq()) ||
-	    !READ_ONCE(rcu_state.gp_flags) ||
-	    !rcu_state.gp_kthread)
+	struct task_struct *t = READ_ONCE(rcu_state.gp_kthread);
+
+	if ((current == t && !in_irq() && !in_serving_softirq()) ||
+	    !READ_ONCE(rcu_state.gp_flags) || !t)
 		return;
 	WRITE_ONCE(rcu_state.gp_wake_time, jiffies);
 	WRITE_ONCE(rcu_state.gp_wake_seq, READ_ONCE(rcu_state.gp_seq));
@@ -1288,9 +1510,10 @@
 
 	/* Trace depending on how much we were able to accelerate. */
 	if (rcu_segcblist_restempty(&rdp->cblist, RCU_WAIT_TAIL))
-		trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("AccWaitCB"));
+		trace_rcu_grace_period(rcu_state.name, gp_seq_req, TPS("AccWaitCB"));
 	else
-		trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("AccReadyCB"));
+		trace_rcu_grace_period(rcu_state.name, gp_seq_req, TPS("AccReadyCB"));
+
 	return ret;
 }
 
@@ -1309,7 +1532,7 @@
 
 	rcu_lockdep_assert_cblist_protected(rdp);
 	c = rcu_seq_snap(&rcu_state.gp_seq);
-	if (!rdp->gpwrap && ULONG_CMP_GE(rdp->gp_seq_needed, c)) {
+	if (!READ_ONCE(rdp->gpwrap) && ULONG_CMP_GE(rdp->gp_seq_needed, c)) {
 		/* Old request still live, so mark recent callbacks. */
 		(void)rcu_segcblist_accelerate(&rdp->cblist, c);
 		return;
@@ -1358,14 +1581,28 @@
 						  struct rcu_data *rdp)
 {
 	rcu_lockdep_assert_cblist_protected(rdp);
-	if (!rcu_seq_state(rcu_seq_current(&rnp->gp_seq)) ||
-	    !raw_spin_trylock_rcu_node(rnp))
+	if (!rcu_seq_state(rcu_seq_current(&rnp->gp_seq)) || !raw_spin_trylock_rcu_node(rnp))
 		return;
-	WARN_ON_ONCE(rcu_advance_cbs(rnp, rdp));
+	// The grace period cannot end while we hold the rcu_node lock.
+	if (rcu_seq_state(rcu_seq_current(&rnp->gp_seq)))
+		WARN_ON_ONCE(rcu_advance_cbs(rnp, rdp));
 	raw_spin_unlock_rcu_node(rnp);
 }
 
 /*
+ * In CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels, attempt to generate a
+ * quiescent state.  This is intended to be invoked when the CPU notices
+ * a new grace period.
+ */
+static void rcu_strict_gp_check_qs(void)
+{
+	if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD)) {
+		rcu_read_lock();
+		rcu_read_unlock();
+	}
+}
+
+/*
  * Update CPU-local rcu_data state to record the beginnings and ends of
  * grace periods.  The caller must hold the ->lock of the leaf rcu_node
  * structure corresponding to the current CPU, and must have irqs disabled.
@@ -1374,7 +1611,7 @@
 static bool __note_gp_changes(struct rcu_node *rnp, struct rcu_data *rdp)
 {
 	bool ret = false;
-	bool need_gp;
+	bool need_qs;
 	const bool offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
 			       rcu_segcblist_is_offloaded(&rdp->cblist);
 
@@ -1388,10 +1625,13 @@
 	    unlikely(READ_ONCE(rdp->gpwrap))) {
 		if (!offloaded)
 			ret = rcu_advance_cbs(rnp, rdp); /* Advance CBs. */
+		rdp->core_needs_qs = false;
 		trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("cpuend"));
 	} else {
 		if (!offloaded)
 			ret = rcu_accelerate_cbs(rnp, rdp); /* Recent CBs. */
+		if (rdp->core_needs_qs)
+			rdp->core_needs_qs = !!(rnp->qsmask & rdp->grpmask);
 	}
 
 	/* Now handle the beginnings of any new-to-this-CPU grace periods. */
@@ -1403,14 +1643,14 @@
 		 * go looking for one.
 		 */
 		trace_rcu_grace_period(rcu_state.name, rnp->gp_seq, TPS("cpustart"));
-		need_gp = !!(rnp->qsmask & rdp->grpmask);
-		rdp->cpu_no_qs.b.norm = need_gp;
-		rdp->core_needs_qs = need_gp;
+		need_qs = !!(rnp->qsmask & rdp->grpmask);
+		rdp->cpu_no_qs.b.norm = need_qs;
+		rdp->core_needs_qs = need_qs;
 		zero_cpu_stall_ticks(rdp);
 	}
 	rdp->gp_seq = rnp->gp_seq;  /* Remember new grace-period state. */
 	if (ULONG_CMP_LT(rdp->gp_seq_needed, rnp->gp_seq_needed) || rdp->gpwrap)
-		rdp->gp_seq_needed = rnp->gp_seq_needed;
+		WRITE_ONCE(rdp->gp_seq_needed, rnp->gp_seq_needed);
 	WRITE_ONCE(rdp->gpwrap, false);
 	rcu_gpnum_ovf(rnp, rdp);
 	return ret;
@@ -1432,6 +1672,7 @@
 	}
 	needwake = __note_gp_changes(rnp, rdp);
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+	rcu_strict_gp_check_qs();
 	if (needwake)
 		rcu_gp_kthread_wake();
 }
@@ -1441,7 +1682,41 @@
 	if (delay > 0 &&
 	    !(rcu_seq_ctr(rcu_state.gp_seq) %
 	      (rcu_num_nodes * PER_RCU_NODE_PERIOD * delay)))
-		schedule_timeout_uninterruptible(delay);
+		schedule_timeout_idle(delay);
+}
+
+static unsigned long sleep_duration;
+
+/* Allow rcutorture to stall the grace-period kthread. */
+void rcu_gp_set_torture_wait(int duration)
+{
+	if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST) && duration > 0)
+		WRITE_ONCE(sleep_duration, duration);
+}
+EXPORT_SYMBOL_GPL(rcu_gp_set_torture_wait);
+
+/* Actually implement the aforementioned wait. */
+static void rcu_gp_torture_wait(void)
+{
+	unsigned long duration;
+
+	if (!IS_ENABLED(CONFIG_RCU_TORTURE_TEST))
+		return;
+	duration = xchg(&sleep_duration, 0UL);
+	if (duration > 0) {
+		pr_alert("%s: Waiting %lu jiffies\n", __func__, duration);
+		schedule_timeout_idle(duration);
+		pr_alert("%s: Wait complete\n", __func__);
+	}
+}
+
+/*
+ * Handler for on_each_cpu() to invoke the target CPU's RCU core
+ * processing.
+ */
+static void rcu_strict_gp_boundary(void *unused)
+{
+	invoke_rcu_core();
 }
 
 /*
@@ -1477,14 +1752,18 @@
 	record_gp_stall_check_time();
 	/* Record GP times before starting GP, hence rcu_seq_start(). */
 	rcu_seq_start(&rcu_state.gp_seq);
+	ASSERT_EXCLUSIVE_WRITER(rcu_state.gp_seq);
 	trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq, TPS("start"));
 	raw_spin_unlock_irq_rcu_node(rnp);
 
 	/*
-	 * Apply per-leaf buffered online and offline operations to the
-	 * rcu_node tree.  Note that this new grace period need not wait
-	 * for subsequent online CPUs, and that quiescent-state forcing
-	 * will handle subsequent offline CPUs.
+	 * Apply per-leaf buffered online and offline operations to
+	 * the rcu_node tree. Note that this new grace period need not
+	 * wait for subsequent online CPUs, and that RCU hooks in the CPU
+	 * offlining path, when combined with checks in this function,
+	 * will handle CPUs that are currently going offline or that will
+	 * go offline later.  Please also refer to "Hotplug CPU" section
+	 * of RCU's Requirements documentation.
 	 */
 	rcu_state.gp_state = RCU_GP_ONOFF;
 	rcu_for_each_leaf_node(rnp) {
@@ -1571,6 +1850,10 @@
 		WRITE_ONCE(rcu_state.gp_activity, jiffies);
 	}
 
+	// If strict, make all CPUs aware of new grace period.
+	if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD))
+		on_each_cpu(rcu_strict_gp_boundary, NULL, 0);
+
 	return true;
 }
 
@@ -1582,12 +1865,16 @@
 {
 	struct rcu_node *rnp = rcu_get_root();
 
-	/* Someone like call_rcu() requested a force-quiescent-state scan. */
+	// If under overload conditions, force an immediate FQS scan.
+	if (*gfp & RCU_GP_FLAG_OVLD)
+		return true;
+
+	// Someone like call_rcu() requested a force-quiescent-state scan.
 	*gfp = READ_ONCE(rcu_state.gp_flags);
 	if (*gfp & RCU_GP_FLAG_FQS)
 		return true;
 
-	/* The current grace period has completed. */
+	// The current grace period has completed.
 	if (!READ_ONCE(rnp->qsmask) && !rcu_preempt_blocked_readers_cgp(rnp))
 		return true;
 
@@ -1602,7 +1889,7 @@
 	struct rcu_node *rnp = rcu_get_root();
 
 	WRITE_ONCE(rcu_state.gp_activity, jiffies);
-	rcu_state.n_force_qs++;
+	WRITE_ONCE(rcu_state.n_force_qs, rcu_state.n_force_qs + 1);
 	if (first_time) {
 		/* Collect dyntick-idle snapshots. */
 		force_qs_rnp(dyntick_save_progress_counter);
@@ -1625,13 +1912,15 @@
 static void rcu_gp_fqs_loop(void)
 {
 	bool first_gp_fqs;
-	int gf;
+	int gf = 0;
 	unsigned long j;
 	int ret;
 	struct rcu_node *rnp = rcu_get_root();
 
 	first_gp_fqs = true;
 	j = READ_ONCE(jiffies_till_first_fqs);
+	if (rcu_state.cbovld)
+		gf = RCU_GP_FLAG_OVLD;
 	ret = 0;
 	for (;;) {
 		if (!ret) {
@@ -1639,12 +1928,12 @@
 			WRITE_ONCE(rcu_state.jiffies_kick_kthreads,
 				   jiffies + (j ? 3 * j : 2));
 		}
-		trace_rcu_grace_period(rcu_state.name,
-				       READ_ONCE(rcu_state.gp_seq),
+		trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq,
 				       TPS("fqswait"));
 		rcu_state.gp_state = RCU_GP_WAIT_FQS;
 		ret = swait_event_idle_timeout_exclusive(
 				rcu_state.gp_wq, rcu_gp_fqs_check_wake(&gf), j);
+		rcu_gp_torture_wait();
 		rcu_state.gp_state = RCU_GP_DOING_FQS;
 		/* Locking provides needed memory barriers. */
 		/* If grace period done, leave loop. */
@@ -1652,15 +1941,17 @@
 		    !rcu_preempt_blocked_readers_cgp(rnp))
 			break;
 		/* If time for quiescent-state forcing, do it. */
-		if (ULONG_CMP_GE(jiffies, rcu_state.jiffies_force_qs) ||
-		    (gf & RCU_GP_FLAG_FQS)) {
-			trace_rcu_grace_period(rcu_state.name,
-					       READ_ONCE(rcu_state.gp_seq),
+		if (!time_after(rcu_state.jiffies_force_qs, jiffies) ||
+		    (gf & (RCU_GP_FLAG_FQS | RCU_GP_FLAG_OVLD))) {
+			trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq,
 					       TPS("fqsstart"));
 			rcu_gp_fqs(first_gp_fqs);
-			first_gp_fqs = false;
-			trace_rcu_grace_period(rcu_state.name,
-					       READ_ONCE(rcu_state.gp_seq),
+			gf = 0;
+			if (first_gp_fqs) {
+				first_gp_fqs = false;
+				gf = rcu_state.cbovld ? RCU_GP_FLAG_OVLD : 0;
+			}
+			trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq,
 					       TPS("fqsend"));
 			cond_resched_tasks_rcu_qs();
 			WRITE_ONCE(rcu_state.gp_activity, jiffies);
@@ -1671,8 +1962,7 @@
 			cond_resched_tasks_rcu_qs();
 			WRITE_ONCE(rcu_state.gp_activity, jiffies);
 			WARN_ON(signal_pending(current));
-			trace_rcu_grace_period(rcu_state.name,
-					       READ_ONCE(rcu_state.gp_seq),
+			trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq,
 					       TPS("fqswaitsig"));
 			ret = 1; /* Keep old FQS timing. */
 			j = jiffies;
@@ -1680,6 +1970,7 @@
 				j = 1;
 			else
 				j = rcu_state.jiffies_force_qs - j;
+			gf = 0;
 		}
 	}
 }
@@ -1689,8 +1980,9 @@
  */
 static void rcu_gp_cleanup(void)
 {
-	unsigned long gp_duration;
+	int cpu;
 	bool needgp = false;
+	unsigned long gp_duration;
 	unsigned long new_gp_seq;
 	bool offloaded;
 	struct rcu_data *rdp;
@@ -1736,6 +2028,12 @@
 			needgp = __note_gp_changes(rnp, rdp) || needgp;
 		/* smp_mb() provided by prior unlock-lock pair. */
 		needgp = rcu_future_gp_cleanup(rnp) || needgp;
+		// Reset overload indication for CPUs no longer overloaded
+		if (rcu_is_leaf_node(rnp))
+			for_each_leaf_node_cpu_mask(rnp, cpu, rnp->cbovldmask) {
+				rdp = per_cpu_ptr(&rcu_data, cpu);
+				check_cb_ovld_locked(rdp, rnp);
+			}
 		sq = rcu_nocb_gp_get(rnp);
 		raw_spin_unlock_irq_rcu_node(rnp);
 		rcu_nocb_gp_cleanup(sq);
@@ -1749,6 +2047,7 @@
 	/* Declare grace period done, trace first to use old GP number. */
 	trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq, TPS("end"));
 	rcu_seq_end(&rcu_state.gp_seq);
+	ASSERT_EXCLUSIVE_WRITER(rcu_state.gp_seq);
 	rcu_state.gp_state = RCU_GP_IDLE;
 	/* Check for GP requests since above loop. */
 	rdp = this_cpu_ptr(&rcu_data);
@@ -1762,15 +2061,19 @@
 		    rcu_segcblist_is_offloaded(&rdp->cblist);
 	if ((offloaded || !rcu_accelerate_cbs(rnp, rdp)) && needgp) {
 		WRITE_ONCE(rcu_state.gp_flags, RCU_GP_FLAG_INIT);
-		rcu_state.gp_req_activity = jiffies;
+		WRITE_ONCE(rcu_state.gp_req_activity, jiffies);
 		trace_rcu_grace_period(rcu_state.name,
-				       READ_ONCE(rcu_state.gp_seq),
+				       rcu_state.gp_seq,
 				       TPS("newreq"));
 	} else {
 		WRITE_ONCE(rcu_state.gp_flags,
 			   rcu_state.gp_flags & RCU_GP_FLAG_INIT);
 	}
 	raw_spin_unlock_irq_rcu_node(rnp);
+
+	// If strict, make all CPUs aware of the end of the old grace period.
+	if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD))
+		on_each_cpu(rcu_strict_gp_boundary, NULL, 0);
 }
 
 /*
@@ -1783,13 +2086,13 @@
 
 		/* Handle grace-period start. */
 		for (;;) {
-			trace_rcu_grace_period(rcu_state.name,
-					       READ_ONCE(rcu_state.gp_seq),
+			trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq,
 					       TPS("reqwait"));
 			rcu_state.gp_state = RCU_GP_WAIT_GPS;
 			swait_event_idle_exclusive(rcu_state.gp_wq,
 					 READ_ONCE(rcu_state.gp_flags) &
 					 RCU_GP_FLAG_INIT);
+			rcu_gp_torture_wait();
 			rcu_state.gp_state = RCU_GP_DONE_GPS;
 			/* Locking provides needed memory barrier. */
 			if (rcu_gp_init())
@@ -1797,8 +2100,7 @@
 			cond_resched_tasks_rcu_qs();
 			WRITE_ONCE(rcu_state.gp_activity, jiffies);
 			WARN_ON(signal_pending(current));
-			trace_rcu_grace_period(rcu_state.name,
-					       READ_ONCE(rcu_state.gp_seq),
+			trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq,
 					       TPS("reqwaitsig"));
 		}
 
@@ -1869,7 +2171,7 @@
 		WARN_ON_ONCE(oldmask); /* Any child must be all zeroed! */
 		WARN_ON_ONCE(!rcu_is_leaf_node(rnp) &&
 			     rcu_preempt_blocked_readers_cgp(rnp));
-		rnp->qsmask &= ~mask;
+		WRITE_ONCE(rnp->qsmask, rnp->qsmask & ~mask);
 		trace_rcu_quiescent_state_report(rcu_state.name, rnp->gp_seq,
 						 mask, rnp->qsmask, rnp->level,
 						 rnp->grplo, rnp->grphi,
@@ -1892,7 +2194,7 @@
 		rnp_c = rnp;
 		rnp = rnp->parent;
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
-		oldmask = rnp_c->qsmask;
+		oldmask = READ_ONCE(rnp_c->qsmask);
 	}
 
 	/*
@@ -1919,7 +2221,7 @@
 	struct rcu_node *rnp_p;
 
 	raw_lockdep_assert_held_rcu_node(rnp);
-	if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPTION)) ||
+	if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT_RCU)) ||
 	    WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)) ||
 	    rnp->qsmask != 0) {
 		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
@@ -1950,7 +2252,7 @@
  * structure.  This must be called from the specified CPU.
  */
 static void
-rcu_report_qs_rdp(int cpu, struct rcu_data *rdp)
+rcu_report_qs_rdp(struct rcu_data *rdp)
 {
 	unsigned long flags;
 	unsigned long mask;
@@ -1959,6 +2261,7 @@
 			       rcu_segcblist_is_offloaded(&rdp->cblist);
 	struct rcu_node *rnp;
 
+	WARN_ON_ONCE(rdp->cpu != smp_processor_id());
 	rnp = rdp->mynode;
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	if (rdp->cpu_no_qs.b.norm || rdp->gp_seq != rnp->gp_seq ||
@@ -1986,6 +2289,7 @@
 		if (!offloaded)
 			needwake = rcu_accelerate_cbs(rnp, rdp);
 
+		rcu_disable_urgency_upon_qs(rdp);
 		rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
 		/* ^^^ Released rnp->lock */
 		if (needwake)
@@ -2023,7 +2327,7 @@
 	 * Tell RCU we are done (but rcu_report_qs_rdp() will be the
 	 * judge of that).
 	 */
-	rcu_report_qs_rdp(rdp->cpu, rdp);
+	rcu_report_qs_rdp(rdp);
 }
 
 /*
@@ -2040,7 +2344,7 @@
 		return 0;
 
 	blkd = !!(rnp->qsmask & rdp->grpmask);
-	trace_rcu_grace_period(rcu_state.name, rnp->gp_seq,
+	trace_rcu_grace_period(rcu_state.name, READ_ONCE(rnp->gp_seq),
 			       blkd ? TPS("cpuofl") : TPS("cpuofl-bgp"));
 	return 0;
 }
@@ -2108,6 +2412,9 @@
 	rcu_boost_kthread_setaffinity(rnp, -1);
 	/* Do any needed no-CB deferred wakeups from this CPU. */
 	do_nocb_deferred_wakeup(per_cpu_ptr(&rcu_data, cpu));
+
+	// Stop-machine done, so allow nohz_full to disable tick.
+	tick_dep_clear(TICK_DEP_BIT_RCU);
 	return 0;
 }
 
@@ -2117,6 +2424,7 @@
  */
 static void rcu_do_batch(struct rcu_data *rdp)
 {
+	int div;
 	unsigned long flags;
 	const bool offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
 			       rcu_segcblist_is_offloaded(&rdp->cblist);
@@ -2128,7 +2436,6 @@
 	/* If no callbacks are ready, just return. */
 	if (!rcu_segcblist_ready_cbs(&rdp->cblist)) {
 		trace_rcu_batch_start(rcu_state.name,
-				      rcu_segcblist_n_lazy_cbs(&rdp->cblist),
 				      rcu_segcblist_n_cbs(&rdp->cblist), 0);
 		trace_rcu_batch_end(rcu_state.name, 0,
 				    !rcu_segcblist_empty(&rdp->cblist),
@@ -2146,11 +2453,16 @@
 	rcu_nocb_lock(rdp);
 	WARN_ON_ONCE(cpu_is_offline(smp_processor_id()));
 	pending = rcu_segcblist_n_cbs(&rdp->cblist);
-	bl = max(rdp->blimit, pending >> rcu_divisor);
-	if (unlikely(bl > 100))
-		tlimit = local_clock() + rcu_resched_ns;
+	div = READ_ONCE(rcu_divisor);
+	div = div < 0 ? 7 : div > sizeof(long) * 8 - 2 ? sizeof(long) * 8 - 2 : div;
+	bl = max(rdp->blimit, pending >> div);
+	if (unlikely(bl > 100)) {
+		long rrn = READ_ONCE(rcu_resched_ns);
+
+		rrn = rrn < NSEC_PER_MSEC ? NSEC_PER_MSEC : rrn > NSEC_PER_SEC ? NSEC_PER_SEC : rrn;
+		tlimit = local_clock() + rrn;
+	}
 	trace_rcu_batch_start(rcu_state.name,
-			      rcu_segcblist_n_lazy_cbs(&rdp->cblist),
 			      rcu_segcblist_n_cbs(&rdp->cblist), bl);
 	rcu_segcblist_extract_done_cbs(&rdp->cblist, &rcl);
 	if (offloaded)
@@ -2158,11 +2470,22 @@
 	rcu_nocb_unlock_irqrestore(rdp, flags);
 
 	/* Invoke callbacks. */
+	tick_dep_set_task(current, TICK_DEP_BIT_RCU);
 	rhp = rcu_cblist_dequeue(&rcl);
 	for (; rhp; rhp = rcu_cblist_dequeue(&rcl)) {
+		rcu_callback_t f;
+
 		debug_rcu_head_unqueue(rhp);
-		if (__rcu_reclaim(rcu_state.name, rhp))
-			rcu_cblist_dequeued_lazy(&rcl);
+
+		rcu_lock_acquire(&rcu_callback_map);
+		trace_rcu_invoke_callback(rcu_state.name, rhp);
+
+		f = rhp->func;
+		WRITE_ONCE(rhp->func, (rcu_callback_t)0L);
+		f(rhp);
+
+		rcu_lock_release(&rcu_callback_map);
+
 		/*
 		 * Stop only if limit reached and CPU has something to do.
 		 * Note: The rcl structure counts down from zero.
@@ -2191,6 +2514,7 @@
 	local_irq_save(flags);
 	rcu_nocb_lock(rdp);
 	count = -rcl.len;
+	rdp->n_cbs_invoked += count;
 	trace_rcu_batch_end(rcu_state.name, count, !!rcl.head, need_resched(),
 			    is_idle_task(current), rcu_is_callbacks_kthread());
 
@@ -2207,7 +2531,7 @@
 	/* Reset ->qlen_last_fqs_check trigger if enough CBs have drained. */
 	if (count == 0 && rdp->qlen_last_fqs_check != 0) {
 		rdp->qlen_last_fqs_check = 0;
-		rdp->n_force_qs_snap = rcu_state.n_force_qs;
+		rdp->n_force_qs_snap = READ_ONCE(rcu_state.n_force_qs);
 	} else if (count < rdp->qlen_last_fqs_check - qhimark)
 		rdp->qlen_last_fqs_check = count;
 
@@ -2224,6 +2548,7 @@
 	/* Re-invoke RCU core processing if there are callbacks remaining. */
 	if (!offloaded && rcu_segcblist_ready_cbs(&rdp->cblist))
 		invoke_rcu_core();
+	tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
 }
 
 /*
@@ -2237,6 +2562,7 @@
 void rcu_sched_clock_irq(int user)
 {
 	trace_rcu_utilization(TPS("Start scheduler-tick"));
+	lockdep_assert_irqs_disabled();
 	raw_cpu_inc(rcu_data.ticks_this_gp);
 	/* The load-acquire pairs with the store-release setting to true. */
 	if (smp_load_acquire(this_cpu_ptr(&rcu_data.rcu_urgent_qs))) {
@@ -2248,8 +2574,9 @@
 		__this_cpu_write(rcu_data.rcu_urgent_qs, false);
 	}
 	rcu_flavor_sched_clock_irq(user);
-	if (rcu_pending())
+	if (rcu_pending(user))
 		invoke_rcu_core();
+	lockdep_assert_irqs_disabled();
 
 	trace_rcu_utilization(TPS("End scheduler-tick"));
 }
@@ -2266,15 +2593,18 @@
 	int cpu;
 	unsigned long flags;
 	unsigned long mask;
+	struct rcu_data *rdp;
 	struct rcu_node *rnp;
 
+	rcu_state.cbovld = rcu_state.cbovldnext;
+	rcu_state.cbovldnext = false;
 	rcu_for_each_leaf_node(rnp) {
 		cond_resched_tasks_rcu_qs();
 		mask = 0;
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
+		rcu_state.cbovldnext |= !!rnp->cbovldmask;
 		if (rnp->qsmask == 0) {
-			if (!IS_ENABLED(CONFIG_PREEMPTION) ||
-			    rcu_preempt_blocked_readers_cgp(rnp)) {
+			if (rcu_preempt_blocked_readers_cgp(rnp)) {
 				/*
 				 * No point in scanning bits because they
 				 * are all zero.  But we might need to
@@ -2287,11 +2617,11 @@
 			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			continue;
 		}
-		for_each_leaf_node_possible_cpu(rnp, cpu) {
-			unsigned long bit = leaf_node_cpu_bit(rnp, cpu);
-			if ((rnp->qsmask & bit) != 0) {
-				if (f(per_cpu_ptr(&rcu_data, cpu)))
-					mask |= bit;
+		for_each_leaf_node_cpu_mask(rnp, cpu, rnp->qsmask) {
+			rdp = per_cpu_ptr(&rcu_data, cpu);
+			if (f(rdp)) {
+				mask |= rdp->grpmask;
+				rcu_disable_urgency_upon_qs(rdp);
 			}
 		}
 		if (mask != 0) {
@@ -2319,7 +2649,7 @@
 	rnp = __this_cpu_read(rcu_data.mynode);
 	for (; rnp != NULL; rnp = rnp->parent) {
 		ret = (READ_ONCE(rcu_state.gp_flags) & RCU_GP_FLAG_FQS) ||
-		      !raw_spin_trylock(&rnp->fqslock);
+		       !raw_spin_trylock(&rnp->fqslock);
 		if (rnp_old != NULL)
 			raw_spin_unlock(&rnp_old->fqslock);
 		if (ret)
@@ -2342,6 +2672,14 @@
 }
 EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
 
+// Workqueue handler for an RCU reader for kernels enforcing struct RCU
+// grace periods.
+static void strict_work_handler(struct work_struct *work)
+{
+	rcu_read_lock();
+	rcu_read_unlock();
+}
+
 /* Perform RCU core processing work for the current CPU.  */
 static __latent_entropy void rcu_core(void)
 {
@@ -2386,6 +2724,10 @@
 	/* Do any needed deferred wakeups of rcuo kthreads. */
 	do_nocb_deferred_wakeup(rdp);
 	trace_rcu_utilization(TPS("End RCU core"));
+
+	// If strict GPs, schedule an RCU reader in a clean environment.
+	if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD))
+		queue_work_on(rdp->cpu, rcu_gp_wq, &rdp->strict_work);
 }
 
 static void rcu_core_si(struct softirq_action *h)
@@ -2450,8 +2792,8 @@
 	char work, *workp = this_cpu_ptr(&rcu_data.rcu_cpu_has_work);
 	int spincnt;
 
+	trace_rcu_utilization(TPS("Start CPU kthread@rcu_run"));
 	for (spincnt = 0; spincnt < 10; spincnt++) {
-		trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
 		local_bh_disable();
 		*statusp = RCU_KTHREAD_RUNNING;
 		local_irq_disable();
@@ -2469,7 +2811,7 @@
 	}
 	*statusp = RCU_KTHREAD_YIELDING;
 	trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
-	schedule_timeout_interruptible(2);
+	schedule_timeout_idle(2);
 	trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
 	*statusp = RCU_KTHREAD_WAITING;
 }
@@ -2535,10 +2877,10 @@
 		} else {
 			/* Give the grace period a kick. */
 			rdp->blimit = DEFAULT_MAX_RCU_BLIMIT;
-			if (rcu_state.n_force_qs == rdp->n_force_qs_snap &&
+			if (READ_ONCE(rcu_state.n_force_qs) == rdp->n_force_qs_snap &&
 			    rcu_segcblist_first_pend_cb(&rdp->cblist) != head)
 				rcu_force_quiescent_state();
-			rdp->n_force_qs_snap = rcu_state.n_force_qs;
+			rdp->n_force_qs_snap = READ_ONCE(rcu_state.n_force_qs);
 			rdp->qlen_last_fqs_check = rcu_segcblist_n_cbs(&rdp->cblist);
 		}
 	}
@@ -2552,13 +2894,50 @@
 }
 
 /*
- * Helper function for call_rcu() and friends.  The cpu argument will
- * normally be -1, indicating "currently running CPU".  It may specify
- * a CPU only if that CPU is a no-CBs CPU.  Currently, only rcu_barrier()
- * is expected to specify a CPU.
+ * Check and if necessary update the leaf rcu_node structure's
+ * ->cbovldmask bit corresponding to the current CPU based on that CPU's
+ * number of queued RCU callbacks.  The caller must hold the leaf rcu_node
+ * structure's ->lock.
  */
+static void check_cb_ovld_locked(struct rcu_data *rdp, struct rcu_node *rnp)
+{
+	raw_lockdep_assert_held_rcu_node(rnp);
+	if (qovld_calc <= 0)
+		return; // Early boot and wildcard value set.
+	if (rcu_segcblist_n_cbs(&rdp->cblist) >= qovld_calc)
+		WRITE_ONCE(rnp->cbovldmask, rnp->cbovldmask | rdp->grpmask);
+	else
+		WRITE_ONCE(rnp->cbovldmask, rnp->cbovldmask & ~rdp->grpmask);
+}
+
+/*
+ * Check and if necessary update the leaf rcu_node structure's
+ * ->cbovldmask bit corresponding to the current CPU based on that CPU's
+ * number of queued RCU callbacks.  No locks need be held, but the
+ * caller must have disabled interrupts.
+ *
+ * Note that this function ignores the possibility that there are a lot
+ * of callbacks all of which have already seen the end of their respective
+ * grace periods.  This omission is due to the need for no-CBs CPUs to
+ * be holding ->nocb_lock to do this check, which is too heavy for a
+ * common-case operation.
+ */
+static void check_cb_ovld(struct rcu_data *rdp)
+{
+	struct rcu_node *const rnp = rdp->mynode;
+
+	if (qovld_calc <= 0 ||
+	    ((rcu_segcblist_n_cbs(&rdp->cblist) >= qovld_calc) ==
+	     !!(READ_ONCE(rnp->cbovldmask) & rdp->grpmask)))
+		return; // Early boot wildcard value or already set correctly.
+	raw_spin_lock_rcu_node(rnp);
+	check_cb_ovld_locked(rdp, rnp);
+	raw_spin_unlock_rcu_node(rnp);
+}
+
+/* Helper function for call_rcu() and friends.  */
 static void
-__call_rcu(struct rcu_head *head, rcu_callback_t func, bool lazy)
+__call_rcu(struct rcu_head *head, rcu_callback_t func)
 {
 	unsigned long flags;
 	struct rcu_data *rdp;
@@ -2581,6 +2960,7 @@
 	head->func = func;
 	head->next = NULL;
 	local_irq_save(flags);
+	kasan_record_aux_stack(head);
 	rdp = this_cpu_ptr(&rcu_data);
 
 	/* Add the callback to our list. */
@@ -2593,18 +2973,18 @@
 		if (rcu_segcblist_empty(&rdp->cblist))
 			rcu_segcblist_init(&rdp->cblist);
 	}
+
+	check_cb_ovld(rdp);
 	if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags))
 		return; // Enqueued onto ->nocb_bypass, so just leave.
-	/* If we get here, rcu_nocb_try_bypass() acquired ->nocb_lock. */
-	rcu_segcblist_enqueue(&rdp->cblist, head, lazy);
-	if (__is_kfree_rcu_offset((unsigned long)func))
-		trace_rcu_kfree_callback(rcu_state.name, head,
+	// If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
+	rcu_segcblist_enqueue(&rdp->cblist, head);
+	if (__is_kvfree_rcu_offset((unsigned long)func))
+		trace_rcu_kvfree_callback(rcu_state.name, head,
 					 (unsigned long)func,
-					 rcu_segcblist_n_lazy_cbs(&rdp->cblist),
 					 rcu_segcblist_n_cbs(&rdp->cblist));
 	else
 		trace_rcu_callback(rcu_state.name, head,
-				   rcu_segcblist_n_lazy_cbs(&rdp->cblist),
 				   rcu_segcblist_n_cbs(&rdp->cblist));
 
 	/* Go handle any RCU core processing required. */
@@ -2654,28 +3034,583 @@
  */
 void call_rcu(struct rcu_head *head, rcu_callback_t func)
 {
-	__call_rcu(head, func, 0);
+	__call_rcu(head, func);
 }
 EXPORT_SYMBOL_GPL(call_rcu);
 
-/*
- * Queue an RCU callback for lazy invocation after a grace period.
- * This will likely be later named something like "call_rcu_lazy()",
- * but this change will require some way of tagging the lazy RCU
- * callbacks in the list of pending callbacks. Until then, this
- * function may only be called from __kfree_rcu().
+
+/* Maximum number of jiffies to wait before draining a batch. */
+#define KFREE_DRAIN_JIFFIES (HZ / 50)
+#define KFREE_N_BATCHES 2
+#define FREE_N_CHANNELS 2
+
+/**
+ * struct kvfree_rcu_bulk_data - single block to store kvfree_rcu() pointers
+ * @nr_records: Number of active pointers in the array
+ * @next: Next bulk object in the block chain
+ * @records: Array of the kvfree_rcu() pointers
  */
-void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
+struct kvfree_rcu_bulk_data {
+	unsigned long nr_records;
+	struct kvfree_rcu_bulk_data *next;
+	void *records[];
+};
+
+/*
+ * This macro defines how many entries the "records" array
+ * will contain. It is based on the fact that the size of
+ * kvfree_rcu_bulk_data structure becomes exactly one page.
+ */
+#define KVFREE_BULK_MAX_ENTR \
+	((PAGE_SIZE - sizeof(struct kvfree_rcu_bulk_data)) / sizeof(void *))
+
+/**
+ * struct kfree_rcu_cpu_work - single batch of kfree_rcu() requests
+ * @rcu_work: Let queue_rcu_work() invoke workqueue handler after grace period
+ * @head_free: List of kfree_rcu() objects waiting for a grace period
+ * @bkvhead_free: Bulk-List of kvfree_rcu() objects waiting for a grace period
+ * @krcp: Pointer to @kfree_rcu_cpu structure
+ */
+
+struct kfree_rcu_cpu_work {
+	struct rcu_work rcu_work;
+	struct rcu_head *head_free;
+	struct kvfree_rcu_bulk_data *bkvhead_free[FREE_N_CHANNELS];
+	struct kfree_rcu_cpu *krcp;
+};
+
+/**
+ * struct kfree_rcu_cpu - batch up kfree_rcu() requests for RCU grace period
+ * @head: List of kfree_rcu() objects not yet waiting for a grace period
+ * @bkvhead: Bulk-List of kvfree_rcu() objects not yet waiting for a grace period
+ * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period
+ * @lock: Synchronize access to this structure
+ * @monitor_work: Promote @head to @head_free after KFREE_DRAIN_JIFFIES
+ * @monitor_todo: Tracks whether a @monitor_work delayed work is pending
+ * @initialized: The @rcu_work fields have been initialized
+ * @count: Number of objects for which GP not started
+ * @bkvcache:
+ *	A simple cache list that contains objects for reuse purpose.
+ *	In order to save some per-cpu space the list is singular.
+ *	Even though it is lockless an access has to be protected by the
+ *	per-cpu lock.
+ * @page_cache_work: A work to refill the cache when it is empty
+ * @work_in_progress: Indicates that page_cache_work is running
+ * @hrtimer: A hrtimer for scheduling a page_cache_work
+ * @nr_bkv_objs: number of allocated objects at @bkvcache.
+ *
+ * This is a per-CPU structure.  The reason that it is not included in
+ * the rcu_data structure is to permit this code to be extracted from
+ * the RCU files.  Such extraction could allow further optimization of
+ * the interactions with the slab allocators.
+ */
+struct kfree_rcu_cpu {
+	struct rcu_head *head;
+	struct kvfree_rcu_bulk_data *bkvhead[FREE_N_CHANNELS];
+	struct kfree_rcu_cpu_work krw_arr[KFREE_N_BATCHES];
+	raw_spinlock_t lock;
+	struct delayed_work monitor_work;
+	bool monitor_todo;
+	bool initialized;
+	int count;
+
+	struct work_struct page_cache_work;
+	atomic_t work_in_progress;
+	struct hrtimer hrtimer;
+
+	struct llist_head bkvcache;
+	int nr_bkv_objs;
+};
+
+static DEFINE_PER_CPU(struct kfree_rcu_cpu, krc) = {
+	.lock = __RAW_SPIN_LOCK_UNLOCKED(krc.lock),
+};
+
+static __always_inline void
+debug_rcu_bhead_unqueue(struct kvfree_rcu_bulk_data *bhead)
 {
-	__call_rcu(head, func, 1);
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+	int i;
+
+	for (i = 0; i < bhead->nr_records; i++)
+		debug_rcu_head_unqueue((struct rcu_head *)(bhead->records[i]));
+#endif
 }
-EXPORT_SYMBOL_GPL(kfree_call_rcu);
+
+static inline struct kfree_rcu_cpu *
+krc_this_cpu_lock(unsigned long *flags)
+{
+	struct kfree_rcu_cpu *krcp;
+
+	local_irq_save(*flags);	// For safely calling this_cpu_ptr().
+	krcp = this_cpu_ptr(&krc);
+	raw_spin_lock(&krcp->lock);
+
+	return krcp;
+}
+
+static inline void
+krc_this_cpu_unlock(struct kfree_rcu_cpu *krcp, unsigned long flags)
+{
+	raw_spin_unlock(&krcp->lock);
+	local_irq_restore(flags);
+}
+
+static inline struct kvfree_rcu_bulk_data *
+get_cached_bnode(struct kfree_rcu_cpu *krcp)
+{
+	if (!krcp->nr_bkv_objs)
+		return NULL;
+
+	krcp->nr_bkv_objs--;
+	return (struct kvfree_rcu_bulk_data *)
+		llist_del_first(&krcp->bkvcache);
+}
+
+static inline bool
+put_cached_bnode(struct kfree_rcu_cpu *krcp,
+	struct kvfree_rcu_bulk_data *bnode)
+{
+	// Check the limit.
+	if (krcp->nr_bkv_objs >= rcu_min_cached_objs)
+		return false;
+
+	llist_add((struct llist_node *) bnode, &krcp->bkvcache);
+	krcp->nr_bkv_objs++;
+	return true;
+
+}
+
+/*
+ * This function is invoked in workqueue context after a grace period.
+ * It frees all the objects queued on ->bhead_free or ->head_free.
+ */
+static void kfree_rcu_work(struct work_struct *work)
+{
+	unsigned long flags;
+	struct kvfree_rcu_bulk_data *bkvhead[FREE_N_CHANNELS], *bnext;
+	struct rcu_head *head, *next;
+	struct kfree_rcu_cpu *krcp;
+	struct kfree_rcu_cpu_work *krwp;
+	int i, j;
+
+	krwp = container_of(to_rcu_work(work),
+			    struct kfree_rcu_cpu_work, rcu_work);
+	krcp = krwp->krcp;
+
+	raw_spin_lock_irqsave(&krcp->lock, flags);
+	// Channels 1 and 2.
+	for (i = 0; i < FREE_N_CHANNELS; i++) {
+		bkvhead[i] = krwp->bkvhead_free[i];
+		krwp->bkvhead_free[i] = NULL;
+	}
+
+	// Channel 3.
+	head = krwp->head_free;
+	krwp->head_free = NULL;
+	raw_spin_unlock_irqrestore(&krcp->lock, flags);
+
+	// Handle two first channels.
+	for (i = 0; i < FREE_N_CHANNELS; i++) {
+		for (; bkvhead[i]; bkvhead[i] = bnext) {
+			bnext = bkvhead[i]->next;
+			debug_rcu_bhead_unqueue(bkvhead[i]);
+
+			rcu_lock_acquire(&rcu_callback_map);
+			if (i == 0) { // kmalloc() / kfree().
+				trace_rcu_invoke_kfree_bulk_callback(
+					rcu_state.name, bkvhead[i]->nr_records,
+					bkvhead[i]->records);
+
+				kfree_bulk(bkvhead[i]->nr_records,
+					bkvhead[i]->records);
+			} else { // vmalloc() / vfree().
+				for (j = 0; j < bkvhead[i]->nr_records; j++) {
+					trace_rcu_invoke_kvfree_callback(
+						rcu_state.name,
+						bkvhead[i]->records[j], 0);
+
+					vfree(bkvhead[i]->records[j]);
+				}
+			}
+			rcu_lock_release(&rcu_callback_map);
+
+			raw_spin_lock_irqsave(&krcp->lock, flags);
+			if (put_cached_bnode(krcp, bkvhead[i]))
+				bkvhead[i] = NULL;
+			raw_spin_unlock_irqrestore(&krcp->lock, flags);
+
+			if (bkvhead[i])
+				free_page((unsigned long) bkvhead[i]);
+
+			cond_resched_tasks_rcu_qs();
+		}
+	}
+
+	/*
+	 * Emergency case only. It can happen under low memory
+	 * condition when an allocation gets failed, so the "bulk"
+	 * path can not be temporary maintained.
+	 */
+	for (; head; head = next) {
+		unsigned long offset = (unsigned long)head->func;
+		void *ptr = (void *)head - offset;
+
+		next = head->next;
+		debug_rcu_head_unqueue((struct rcu_head *)ptr);
+		rcu_lock_acquire(&rcu_callback_map);
+		trace_rcu_invoke_kvfree_callback(rcu_state.name, head, offset);
+
+		if (!WARN_ON_ONCE(!__is_kvfree_rcu_offset(offset)))
+			kvfree(ptr);
+
+		rcu_lock_release(&rcu_callback_map);
+		cond_resched_tasks_rcu_qs();
+	}
+}
+
+/*
+ * Schedule the kfree batch RCU work to run in workqueue context after a GP.
+ *
+ * This function is invoked by kfree_rcu_monitor() when the KFREE_DRAIN_JIFFIES
+ * timeout has been reached.
+ */
+static inline bool queue_kfree_rcu_work(struct kfree_rcu_cpu *krcp)
+{
+	struct kfree_rcu_cpu_work *krwp;
+	bool repeat = false;
+	int i, j;
+
+	lockdep_assert_held(&krcp->lock);
+
+	for (i = 0; i < KFREE_N_BATCHES; i++) {
+		krwp = &(krcp->krw_arr[i]);
+
+		/*
+		 * Try to detach bkvhead or head and attach it over any
+		 * available corresponding free channel. It can be that
+		 * a previous RCU batch is in progress, it means that
+		 * immediately to queue another one is not possible so
+		 * return false to tell caller to retry.
+		 */
+		if ((krcp->bkvhead[0] && !krwp->bkvhead_free[0]) ||
+			(krcp->bkvhead[1] && !krwp->bkvhead_free[1]) ||
+				(krcp->head && !krwp->head_free)) {
+			// Channel 1 corresponds to SLAB ptrs.
+			// Channel 2 corresponds to vmalloc ptrs.
+			for (j = 0; j < FREE_N_CHANNELS; j++) {
+				if (!krwp->bkvhead_free[j]) {
+					krwp->bkvhead_free[j] = krcp->bkvhead[j];
+					krcp->bkvhead[j] = NULL;
+				}
+			}
+
+			// Channel 3 corresponds to emergency path.
+			if (!krwp->head_free) {
+				krwp->head_free = krcp->head;
+				krcp->head = NULL;
+			}
+
+			WRITE_ONCE(krcp->count, 0);
+
+			/*
+			 * One work is per one batch, so there are three
+			 * "free channels", the batch can handle. It can
+			 * be that the work is in the pending state when
+			 * channels have been detached following by each
+			 * other.
+			 */
+			queue_rcu_work(system_wq, &krwp->rcu_work);
+		}
+
+		// Repeat if any "free" corresponding channel is still busy.
+		if (krcp->bkvhead[0] || krcp->bkvhead[1] || krcp->head)
+			repeat = true;
+	}
+
+	return !repeat;
+}
+
+static inline void kfree_rcu_drain_unlock(struct kfree_rcu_cpu *krcp,
+					  unsigned long flags)
+{
+	// Attempt to start a new batch.
+	krcp->monitor_todo = false;
+	if (queue_kfree_rcu_work(krcp)) {
+		// Success! Our job is done here.
+		raw_spin_unlock_irqrestore(&krcp->lock, flags);
+		return;
+	}
+
+	// Previous RCU batch still in progress, try again later.
+	krcp->monitor_todo = true;
+	schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
+	raw_spin_unlock_irqrestore(&krcp->lock, flags);
+}
+
+/*
+ * This function is invoked after the KFREE_DRAIN_JIFFIES timeout.
+ * It invokes kfree_rcu_drain_unlock() to attempt to start another batch.
+ */
+static void kfree_rcu_monitor(struct work_struct *work)
+{
+	unsigned long flags;
+	struct kfree_rcu_cpu *krcp = container_of(work, struct kfree_rcu_cpu,
+						 monitor_work.work);
+
+	raw_spin_lock_irqsave(&krcp->lock, flags);
+	if (krcp->monitor_todo)
+		kfree_rcu_drain_unlock(krcp, flags);
+	else
+		raw_spin_unlock_irqrestore(&krcp->lock, flags);
+}
+
+static enum hrtimer_restart
+schedule_page_work_fn(struct hrtimer *t)
+{
+	struct kfree_rcu_cpu *krcp =
+		container_of(t, struct kfree_rcu_cpu, hrtimer);
+
+	queue_work(system_highpri_wq, &krcp->page_cache_work);
+	return HRTIMER_NORESTART;
+}
+
+static void fill_page_cache_func(struct work_struct *work)
+{
+	struct kvfree_rcu_bulk_data *bnode;
+	struct kfree_rcu_cpu *krcp =
+		container_of(work, struct kfree_rcu_cpu,
+			page_cache_work);
+	unsigned long flags;
+	bool pushed;
+	int i;
+
+	for (i = 0; i < rcu_min_cached_objs; i++) {
+		bnode = (struct kvfree_rcu_bulk_data *)
+			__get_free_page(GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
+
+		if (bnode) {
+			raw_spin_lock_irqsave(&krcp->lock, flags);
+			pushed = put_cached_bnode(krcp, bnode);
+			raw_spin_unlock_irqrestore(&krcp->lock, flags);
+
+			if (!pushed) {
+				free_page((unsigned long) bnode);
+				break;
+			}
+		}
+	}
+
+	atomic_set(&krcp->work_in_progress, 0);
+}
+
+static void
+run_page_cache_worker(struct kfree_rcu_cpu *krcp)
+{
+	if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING &&
+			!atomic_xchg(&krcp->work_in_progress, 1)) {
+		hrtimer_init(&krcp->hrtimer, CLOCK_MONOTONIC,
+			HRTIMER_MODE_REL);
+		krcp->hrtimer.function = schedule_page_work_fn;
+		hrtimer_start(&krcp->hrtimer, 0, HRTIMER_MODE_REL);
+	}
+}
+
+static inline bool
+kvfree_call_rcu_add_ptr_to_bulk(struct kfree_rcu_cpu *krcp, void *ptr)
+{
+	struct kvfree_rcu_bulk_data *bnode;
+	int idx;
+
+	if (unlikely(!krcp->initialized))
+		return false;
+
+	lockdep_assert_held(&krcp->lock);
+	idx = !!is_vmalloc_addr(ptr);
+
+	/* Check if a new block is required. */
+	if (!krcp->bkvhead[idx] ||
+			krcp->bkvhead[idx]->nr_records == KVFREE_BULK_MAX_ENTR) {
+		bnode = get_cached_bnode(krcp);
+		/* Switch to emergency path. */
+		if (!bnode)
+			return false;
+
+		/* Initialize the new block. */
+		bnode->nr_records = 0;
+		bnode->next = krcp->bkvhead[idx];
+
+		/* Attach it to the head. */
+		krcp->bkvhead[idx] = bnode;
+	}
+
+	/* Finally insert. */
+	krcp->bkvhead[idx]->records
+		[krcp->bkvhead[idx]->nr_records++] = ptr;
+
+	return true;
+}
+
+/*
+ * Queue a request for lazy invocation of appropriate free routine after a
+ * grace period. Please note there are three paths are maintained, two are the
+ * main ones that use array of pointers interface and third one is emergency
+ * one, that is used only when the main path can not be maintained temporary,
+ * due to memory pressure.
+ *
+ * Each kvfree_call_rcu() request is added to a batch. The batch will be drained
+ * every KFREE_DRAIN_JIFFIES number of jiffies. All the objects in the batch will
+ * be free'd in workqueue context. This allows us to: batch requests together to
+ * reduce the number of grace periods during heavy kfree_rcu()/kvfree_rcu() load.
+ */
+void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
+{
+	unsigned long flags;
+	struct kfree_rcu_cpu *krcp;
+	bool success;
+	void *ptr;
+
+	if (head) {
+		ptr = (void *) head - (unsigned long) func;
+	} else {
+		/*
+		 * Please note there is a limitation for the head-less
+		 * variant, that is why there is a clear rule for such
+		 * objects: it can be used from might_sleep() context
+		 * only. For other places please embed an rcu_head to
+		 * your data.
+		 */
+		might_sleep();
+		ptr = (unsigned long *) func;
+	}
+
+	krcp = krc_this_cpu_lock(&flags);
+
+	// Queue the object but don't yet schedule the batch.
+	if (debug_rcu_head_queue(ptr)) {
+		// Probable double kfree_rcu(), just leak.
+		WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n",
+			  __func__, head);
+
+		// Mark as success and leave.
+		success = true;
+		goto unlock_return;
+	}
+
+	success = kvfree_call_rcu_add_ptr_to_bulk(krcp, ptr);
+	if (!success) {
+		run_page_cache_worker(krcp);
+
+		if (head == NULL)
+			// Inline if kvfree_rcu(one_arg) call.
+			goto unlock_return;
+
+		head->func = func;
+		head->next = krcp->head;
+		krcp->head = head;
+		success = true;
+	}
+
+	WRITE_ONCE(krcp->count, krcp->count + 1);
+
+	// Set timer to drain after KFREE_DRAIN_JIFFIES.
+	if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING &&
+	    !krcp->monitor_todo) {
+		krcp->monitor_todo = true;
+		schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
+	}
+
+unlock_return:
+	krc_this_cpu_unlock(krcp, flags);
+
+	/*
+	 * Inline kvfree() after synchronize_rcu(). We can do
+	 * it from might_sleep() context only, so the current
+	 * CPU can pass the QS state.
+	 */
+	if (!success) {
+		debug_rcu_head_unqueue((struct rcu_head *) ptr);
+		synchronize_rcu();
+		kvfree(ptr);
+	}
+}
+EXPORT_SYMBOL_GPL(kvfree_call_rcu);
+
+static unsigned long
+kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	int cpu;
+	unsigned long count = 0;
+
+	/* Snapshot count of all CPUs */
+	for_each_possible_cpu(cpu) {
+		struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
+
+		count += READ_ONCE(krcp->count);
+	}
+
+	return count;
+}
+
+static unsigned long
+kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	int cpu, freed = 0;
+	unsigned long flags;
+
+	for_each_possible_cpu(cpu) {
+		int count;
+		struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
+
+		count = krcp->count;
+		raw_spin_lock_irqsave(&krcp->lock, flags);
+		if (krcp->monitor_todo)
+			kfree_rcu_drain_unlock(krcp, flags);
+		else
+			raw_spin_unlock_irqrestore(&krcp->lock, flags);
+
+		sc->nr_to_scan -= count;
+		freed += count;
+
+		if (sc->nr_to_scan <= 0)
+			break;
+	}
+
+	return freed == 0 ? SHRINK_STOP : freed;
+}
+
+static struct shrinker kfree_rcu_shrinker = {
+	.count_objects = kfree_rcu_shrink_count,
+	.scan_objects = kfree_rcu_shrink_scan,
+	.batch = 0,
+	.seeks = DEFAULT_SEEKS,
+};
+
+void __init kfree_rcu_scheduler_running(void)
+{
+	int cpu;
+	unsigned long flags;
+
+	for_each_possible_cpu(cpu) {
+		struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
+
+		raw_spin_lock_irqsave(&krcp->lock, flags);
+		if (!krcp->head || krcp->monitor_todo) {
+			raw_spin_unlock_irqrestore(&krcp->lock, flags);
+			continue;
+		}
+		krcp->monitor_todo = true;
+		schedule_delayed_work_on(cpu, &krcp->monitor_work,
+					 KFREE_DRAIN_JIFFIES);
+		raw_spin_unlock_irqrestore(&krcp->lock, flags);
+	}
+}
 
 /*
  * During early boot, any blocking grace-period wait automatically
- * implies a grace period.  Later on, this is never the case for PREEMPT.
+ * implies a grace period.  Later on, this is never the case for PREEMPTION.
  *
- * Howevr, because a context switch is a grace period for !PREEMPT, any
+ * Howevr, because a context switch is a grace period for !PREEMPTION, any
  * blocking grace-period wait automatically implies a grace period if
  * there is only one CPU online at any point time during execution of
  * either synchronize_rcu() or synchronize_rcu_expedited().  It is OK to
@@ -2792,11 +3727,14 @@
  * CPU-local state are performed first.  However, we must check for CPU
  * stalls first, else we might not get a chance.
  */
-static int rcu_pending(void)
+static int rcu_pending(int user)
 {
+	bool gp_in_progress;
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 	struct rcu_node *rnp = rdp->mynode;
 
+	lockdep_assert_irqs_disabled();
+
 	/* Check for CPU stalls, if enabled. */
 	check_cpu_stall(rdp);
 
@@ -2804,12 +3742,13 @@
 	if (rcu_nocb_need_deferred_wakeup(rdp))
 		return 1;
 
-	/* Is this CPU a NO_HZ_FULL CPU that should ignore RCU? */
-	if (rcu_nohz_full_cpu())
+	/* Is this a nohz_full CPU in userspace or idle?  (Ignore RCU if so.) */
+	if ((user || rcu_is_cpu_rrupt_from_idle()) && rcu_nohz_full_cpu())
 		return 0;
 
 	/* Is the RCU core waiting for a quiescent state from this CPU? */
-	if (rdp->core_needs_qs && !rdp->cpu_no_qs.b.norm)
+	gp_in_progress = rcu_gp_in_progress();
+	if (rdp->core_needs_qs && !rdp->cpu_no_qs.b.norm && gp_in_progress)
 		return 1;
 
 	/* Does this CPU have callbacks ready to invoke? */
@@ -2817,8 +3756,7 @@
 		return 1;
 
 	/* Has RCU gone idle with this CPU needing another grace period? */
-	if (!rcu_gp_in_progress() &&
-	    rcu_segcblist_is_enabled(&rdp->cblist) &&
+	if (!gp_in_progress && rcu_segcblist_is_enabled(&rdp->cblist) &&
 	    (!IS_ENABLED(CONFIG_RCU_NOCB_CPU) ||
 	     !rcu_segcblist_is_offloaded(&rdp->cblist)) &&
 	    !rcu_segcblist_restempty(&rdp->cblist, RCU_NEXT_READY_TAIL))
@@ -2846,36 +3784,44 @@
 /*
  * RCU callback function for rcu_barrier().  If we are last, wake
  * up the task executing rcu_barrier().
+ *
+ * Note that the value of rcu_state.barrier_sequence must be captured
+ * before the atomic_dec_and_test().  Otherwise, if this CPU is not last,
+ * other CPUs might count the value down to zero before this CPU gets
+ * around to invoking rcu_barrier_trace(), which might result in bogus
+ * data from the next instance of rcu_barrier().
  */
 static void rcu_barrier_callback(struct rcu_head *rhp)
 {
+	unsigned long __maybe_unused s = rcu_state.barrier_sequence;
+
 	if (atomic_dec_and_test(&rcu_state.barrier_cpu_count)) {
-		rcu_barrier_trace(TPS("LastCB"), -1,
-				   rcu_state.barrier_sequence);
+		rcu_barrier_trace(TPS("LastCB"), -1, s);
 		complete(&rcu_state.barrier_completion);
 	} else {
-		rcu_barrier_trace(TPS("CB"), -1, rcu_state.barrier_sequence);
+		rcu_barrier_trace(TPS("CB"), -1, s);
 	}
 }
 
 /*
  * Called with preemption disabled, and from cross-cpu IRQ context.
  */
-static void rcu_barrier_func(void *unused)
+static void rcu_barrier_func(void *cpu_in)
 {
-	struct rcu_data *rdp = raw_cpu_ptr(&rcu_data);
+	uintptr_t cpu = (uintptr_t)cpu_in;
+	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
 
 	rcu_barrier_trace(TPS("IRQ"), -1, rcu_state.barrier_sequence);
 	rdp->barrier_head.func = rcu_barrier_callback;
 	debug_rcu_head_queue(&rdp->barrier_head);
 	rcu_nocb_lock(rdp);
 	WARN_ON_ONCE(!rcu_nocb_flush_bypass(rdp, NULL, jiffies));
-	if (rcu_segcblist_entrain(&rdp->cblist, &rdp->barrier_head, 0)) {
+	if (rcu_segcblist_entrain(&rdp->cblist, &rdp->barrier_head)) {
 		atomic_inc(&rcu_state.barrier_cpu_count);
 	} else {
 		debug_rcu_head_unqueue(&rdp->barrier_head);
 		rcu_barrier_trace(TPS("IRQNQ"), -1,
-				   rcu_state.barrier_sequence);
+				  rcu_state.barrier_sequence);
 	}
 	rcu_nocb_unlock(rdp);
 }
@@ -2890,7 +3836,7 @@
  */
 void rcu_barrier(void)
 {
-	int cpu;
+	uintptr_t cpu;
 	struct rcu_data *rdp;
 	unsigned long s = rcu_seq_snap(&rcu_state.barrier_sequence);
 
@@ -2902,7 +3848,7 @@
 	/* Did someone else do our work for us? */
 	if (rcu_seq_done(&rcu_state.barrier_sequence, s)) {
 		rcu_barrier_trace(TPS("EarlyExit"), -1,
-				   rcu_state.barrier_sequence);
+				  rcu_state.barrier_sequence);
 		smp_mb(); /* caller's subsequent code after above check. */
 		mutex_unlock(&rcu_state.barrier_mutex);
 		return;
@@ -2913,13 +3859,14 @@
 	rcu_barrier_trace(TPS("Inc1"), -1, rcu_state.barrier_sequence);
 
 	/*
-	 * Initialize the count to one rather than to zero in order to
-	 * avoid a too-soon return to zero in case of a short grace period
-	 * (or preemption of this task).  Exclude CPU-hotplug operations
-	 * to ensure that no offline CPU has callbacks queued.
+	 * Initialize the count to two rather than to zero in order
+	 * to avoid a too-soon return to zero in case of an immediate
+	 * invocation of the just-enqueued callback (or preemption of
+	 * this task).  Exclude CPU-hotplug operations to ensure that no
+	 * offline non-offloaded CPU has callbacks queued.
 	 */
 	init_completion(&rcu_state.barrier_completion);
-	atomic_set(&rcu_state.barrier_cpu_count, 1);
+	atomic_set(&rcu_state.barrier_cpu_count, 2);
 	get_online_cpus();
 
 	/*
@@ -2929,16 +3876,26 @@
 	 */
 	for_each_possible_cpu(cpu) {
 		rdp = per_cpu_ptr(&rcu_data, cpu);
-		if (!cpu_online(cpu) &&
+		if (cpu_is_offline(cpu) &&
 		    !rcu_segcblist_is_offloaded(&rdp->cblist))
 			continue;
-		if (rcu_segcblist_n_cbs(&rdp->cblist)) {
+		if (rcu_segcblist_n_cbs(&rdp->cblist) && cpu_online(cpu)) {
 			rcu_barrier_trace(TPS("OnlineQ"), cpu,
-					   rcu_state.barrier_sequence);
-			smp_call_function_single(cpu, rcu_barrier_func, NULL, 1);
+					  rcu_state.barrier_sequence);
+			smp_call_function_single(cpu, rcu_barrier_func, (void *)cpu, 1);
+		} else if (rcu_segcblist_n_cbs(&rdp->cblist) &&
+			   cpu_is_offline(cpu)) {
+			rcu_barrier_trace(TPS("OfflineNoCBQ"), cpu,
+					  rcu_state.barrier_sequence);
+			local_irq_disable();
+			rcu_barrier_func((void *)cpu);
+			local_irq_enable();
+		} else if (cpu_is_offline(cpu)) {
+			rcu_barrier_trace(TPS("OfflineNoCBNoQ"), cpu,
+					  rcu_state.barrier_sequence);
 		} else {
 			rcu_barrier_trace(TPS("OnlineNQ"), cpu,
-					   rcu_state.barrier_sequence);
+					  rcu_state.barrier_sequence);
 		}
 	}
 	put_online_cpus();
@@ -2947,7 +3904,7 @@
 	 * Now that we have an rcu_barrier_callback() callback on each
 	 * CPU, and thus each counted, remove the initial count.
 	 */
-	if (atomic_dec_and_test(&rcu_state.barrier_cpu_count))
+	if (atomic_sub_and_test(2, &rcu_state.barrier_cpu_count))
 		complete(&rcu_state.barrier_completion);
 
 	/* Wait for all rcu_barrier_callback() callbacks to be invoked. */
@@ -3000,6 +3957,7 @@
 
 	/* Set up local state, ensuring consistent view of global state. */
 	rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu);
+	INIT_WORK(&rdp->strict_work, strict_work_handler);
 	WARN_ON_ONCE(rdp->dynticks_nesting != 1);
 	WARN_ON_ONCE(rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp)));
 	rdp->rcu_ofl_gp_seq = rcu_state.gp_seq;
@@ -3029,7 +3987,7 @@
 	/* Set up local state, ensuring consistent view of global state. */
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	rdp->qlen_last_fqs_check = 0;
-	rdp->n_force_qs_snap = rcu_state.n_force_qs;
+	rdp->n_force_qs_snap = READ_ONCE(rcu_state.n_force_qs);
 	rdp->blimit = blimit;
 	if (rcu_segcblist_empty(&rdp->cblist) && /* No early-boot CBs? */
 	    !rcu_segcblist_is_offloaded(&rdp->cblist))
@@ -3046,12 +4004,12 @@
 	rnp = rdp->mynode;
 	raw_spin_lock_rcu_node(rnp);		/* irqs already disabled. */
 	rdp->beenonline = true;	 /* We have now been online. */
-	rdp->gp_seq = rnp->gp_seq;
-	rdp->gp_seq_needed = rnp->gp_seq;
+	rdp->gp_seq = READ_ONCE(rnp->gp_seq);
+	rdp->gp_seq_needed = rdp->gp_seq;
 	rdp->cpu_no_qs.b.norm = true;
 	rdp->core_needs_qs = false;
 	rdp->rcu_iw_pending = false;
-	rdp->rcu_iw_gp_seq = rnp->gp_seq - 1;
+	rdp->rcu_iw_gp_seq = rdp->gp_seq - 1;
 	trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("cpuonl"));
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	rcu_prepare_kthreads(cpu);
@@ -3089,6 +4047,9 @@
 		return 0; /* Too early in boot for scheduler work. */
 	sync_sched_exp_online_cleanup(cpu);
 	rcutree_affinity_setting(cpu, -1);
+
+	// Stop-machine done, so allow nohz_full to disable tick.
+	tick_dep_clear(TICK_DEP_BIT_RCU);
 	return 0;
 }
 
@@ -3109,11 +4070,12 @@
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 	rcutree_affinity_setting(cpu, cpu);
+
+	// nohz_full CPUs need the tick for stop-machine to work quickly
+	tick_dep_set(TICK_DEP_BIT_RCU);
 	return 0;
 }
 
-static DEFINE_PER_CPU(int, rcu_cpu_started);
-
 /*
  * Mark the specified CPU as being online so that subsequent grace periods
  * (both expedited and normal) will wait on it.  Note that this means that
@@ -3129,31 +4091,29 @@
 {
 	unsigned long flags;
 	unsigned long mask;
-	int nbits;
-	unsigned long oldmask;
 	struct rcu_data *rdp;
 	struct rcu_node *rnp;
-
-	if (per_cpu(rcu_cpu_started, cpu))
-		return;
-
-	per_cpu(rcu_cpu_started, cpu) = 1;
+	bool newcpu;
 
 	rdp = per_cpu_ptr(&rcu_data, cpu);
+	if (rdp->cpu_started)
+		return;
+	rdp->cpu_started = true;
+
 	rnp = rdp->mynode;
 	mask = rdp->grpmask;
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
-	rnp->qsmaskinitnext |= mask;
-	oldmask = rnp->expmaskinitnext;
+	WRITE_ONCE(rnp->qsmaskinitnext, rnp->qsmaskinitnext | mask);
+	newcpu = !(rnp->expmaskinitnext & mask);
 	rnp->expmaskinitnext |= mask;
-	oldmask ^= rnp->expmaskinitnext;
-	nbits = bitmap_weight(&oldmask, BITS_PER_LONG);
 	/* Allow lockless access for expedited grace periods. */
-	smp_store_release(&rcu_state.ncpus, rcu_state.ncpus + nbits); /* ^^^ */
+	smp_store_release(&rcu_state.ncpus, rcu_state.ncpus + newcpu); /* ^^^ */
+	ASSERT_EXCLUSIVE_WRITER(rcu_state.ncpus);
 	rcu_gpnum_ovf(rnp, rdp); /* Offline-induced counter wrap? */
 	rdp->rcu_onl_gp_seq = READ_ONCE(rcu_state.gp_seq);
 	rdp->rcu_onl_gp_flags = READ_ONCE(rcu_state.gp_flags);
 	if (rnp->qsmask & mask) { /* RCU waiting on incoming CPU? */
+		rcu_disable_urgency_upon_qs(rdp);
 		/* Report QS -after- changing ->qsmaskinitnext! */
 		rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
 	} else {
@@ -3194,11 +4154,11 @@
 		rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	}
-	rnp->qsmaskinitnext &= ~mask;
+	WRITE_ONCE(rnp->qsmaskinitnext, rnp->qsmaskinitnext & ~mask);
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	raw_spin_unlock(&rcu_state.ofl_lock);
 
-	per_cpu(rcu_cpu_started, cpu) = 0;
+	rdp->cpu_started = false;
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -3309,7 +4269,10 @@
 	}
 	rnp = rcu_get_root();
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
-	rcu_state.gp_kthread = t;
+	WRITE_ONCE(rcu_state.gp_activity, jiffies);
+	WRITE_ONCE(rcu_state.gp_req_activity, jiffies);
+	// Reset .gp_activity and .gp_req_activity before setting .gp_kthread.
+	smp_store_release(&rcu_state.gp_kthread, t);  /* ^^^ */
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	wake_up_process(t);
 	rcu_spawn_nocb_kthreads();
@@ -3539,12 +4502,34 @@
 struct workqueue_struct *rcu_gp_wq;
 struct workqueue_struct *rcu_par_gp_wq;
 
+static void __init kfree_rcu_batch_init(void)
+{
+	int cpu;
+	int i;
+
+	for_each_possible_cpu(cpu) {
+		struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
+
+		for (i = 0; i < KFREE_N_BATCHES; i++) {
+			INIT_RCU_WORK(&krcp->krw_arr[i].rcu_work, kfree_rcu_work);
+			krcp->krw_arr[i].krcp = krcp;
+		}
+
+		INIT_DELAYED_WORK(&krcp->monitor_work, kfree_rcu_monitor);
+		INIT_WORK(&krcp->page_cache_work, fill_page_cache_func);
+		krcp->initialized = true;
+	}
+	if (register_shrinker(&kfree_rcu_shrinker))
+		pr_err("Failed to register kfree_rcu() shrinker!\n");
+}
+
 void __init rcu_init(void)
 {
 	int cpu;
 
 	rcu_early_boot_tests();
 
+	kfree_rcu_batch_init();
 	rcu_bootup_announce();
 	rcu_init_geometry();
 	rcu_init_one();
@@ -3571,6 +4556,13 @@
 	rcu_par_gp_wq = alloc_workqueue("rcu_par_gp", WQ_MEM_RECLAIM, 0);
 	WARN_ON(!rcu_par_gp_wq);
 	srcu_init();
+
+	/* Fill in default value for rcutree.qovld boot parameter. */
+	/* -After- the rcu_node ->lock fields are initialized! */
+	if (qovld < 0)
+		qovld_calc = DEFAULT_RCU_QOVLD_MULT * qhimark;
+	else
+		qovld_calc = qovld;
 }
 
 #include "tree_stall.h"
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index c612f30..e4f66b8 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -16,7 +16,6 @@
 #include <linux/cpumask.h>
 #include <linux/seqlock.h>
 #include <linux/swait.h>
-#include <linux/stop_machine.h>
 #include <linux/rcu_node_tree.h>
 
 #include "rcu_segcblist.h"
@@ -42,7 +41,7 @@
 	raw_spinlock_t __private lock;	/* Root rcu_node's lock protects */
 					/*  some rcu_state fields as well as */
 					/*  following. */
-	unsigned long gp_seq;	/* Track rsp->rcu_gp_seq. */
+	unsigned long gp_seq;	/* Track rsp->gp_seq. */
 	unsigned long gp_seq_needed; /* Track furthest future GP request. */
 	unsigned long completedqs; /* All QSes done for this node. */
 	unsigned long qsmask;	/* CPUs or groups that need to switch in */
@@ -69,12 +68,14 @@
 				/* Online CPUs for next expedited GP. */
 				/*  Any CPU that has ever been online will */
 				/*  have its bit set. */
+	unsigned long cbovldmask;
+				/* CPUs experiencing callback overload. */
 	unsigned long ffmask;	/* Fully functional CPUs. */
 	unsigned long grpmask;	/* Mask to apply to parent qsmask. */
 				/*  Only one bit will be set in this mask. */
-	int	grplo;		/* lowest-numbered CPU or group here. */
-	int	grphi;		/* highest-numbered CPU or group here. */
-	u8	grpnum;		/* CPU/group number for next level up. */
+	int	grplo;		/* lowest-numbered CPU here. */
+	int	grphi;		/* highest-numbered CPU here. */
+	u8	grpnum;		/* group number for next level up. */
 	u8	level;		/* root is at level 0. */
 	bool	wait_blkd_tasks;/* Necessary to wait for blocked tasks to */
 				/*  exit RCU read-side critical sections */
@@ -148,13 +149,14 @@
 /* Per-CPU data for read-copy update. */
 struct rcu_data {
 	/* 1) quiescent-state and grace-period handling : */
-	unsigned long	gp_seq;		/* Track rsp->rcu_gp_seq counter. */
+	unsigned long	gp_seq;		/* Track rsp->gp_seq counter. */
 	unsigned long	gp_seq_needed;	/* Track furthest future GP request. */
 	union rcu_noqs	cpu_no_qs;	/* No QSes yet for this CPU. */
 	bool		core_needs_qs;	/* Core waits for quiesc state. */
 	bool		beenonline;	/* CPU online at least once. */
 	bool		gpwrap;		/* Possible ->gp_seq wrap. */
 	bool		exp_deferred_qs; /* This CPU awaiting a deferred QS? */
+	bool		cpu_started;	/* RCU watching this onlining CPU. */
 	struct rcu_node *mynode;	/* This CPU's leaf of hierarchy */
 	unsigned long grpmask;		/* Mask to apply to leaf qsmask. */
 	unsigned long	ticks_this_gp;	/* The number of scheduling-clock */
@@ -163,6 +165,7 @@
 					/* period it is aware of. */
 	struct irq_work defer_qs_iw;	/* Obtain later scheduler attention. */
 	bool defer_qs_iw_pending;	/* Scheduler attention pending? */
+	struct work_struct strict_work;	/* Schedule readers for strict GPs. */
 
 	/* 2) batch handling */
 	struct rcu_segcblist cblist;	/* Segmented callback list, with */
@@ -170,6 +173,7 @@
 					/* different grace periods. */
 	long		qlen_last_fqs_check;
 					/* qlen at last check for QS forcing */
+	unsigned long	n_cbs_invoked;	/* # callbacks invoked since boot. */
 	unsigned long	n_force_qs_snap;
 					/* did other CPU force QS recently? */
 	long		blimit;		/* Upper limit on a processed batch */
@@ -181,8 +185,9 @@
 	atomic_t dynticks;		/* Even value for idle, else odd. */
 	bool rcu_need_heavy_qs;		/* GP old, so heavy quiescent state! */
 	bool rcu_urgent_qs;		/* GP old need light quiescent state. */
+	bool rcu_forced_tick;		/* Forced tick to provide QS. */
+	bool rcu_forced_tick_exp;	/*   ... provide QS to expedited GP. */
 #ifdef CONFIG_RCU_FAST_NO_HZ
-	bool all_lazy;			/* All CPU's CBs lazy at idle start? */
 	unsigned long last_accelerate;	/* Last jiffy CBs were accelerated. */
 	unsigned long last_advance_all;	/* Last jiffy CBs were all advanced. */
 	int tick_nohz_enabled_snap;	/* Previously seen value from sysfs. */
@@ -299,6 +304,8 @@
 	u8	boost ____cacheline_internodealigned_in_smp;
 						/* Subject to priority boost. */
 	unsigned long gp_seq;			/* Grace-period sequence #. */
+	unsigned long gp_max;			/* Maximum GP duration in */
+						/*  jiffies. */
 	struct task_struct *gp_kthread;		/* Task for grace periods. */
 	struct swait_queue_head gp_wq;		/* Where GP task waits. */
 	short gp_flags;				/* Commands for GP task. */
@@ -321,6 +328,8 @@
 	atomic_t expedited_need_qs;		/* # CPUs left to check in. */
 	struct swait_queue_head expedited_wq;	/* Wait for check-ins. */
 	int ncpus_snap;				/* # CPUs seen last time. */
+	u8 cbovld;				/* Callback overload now? */
+	u8 cbovldnext;				/* ^        ^  next time? */
 
 	unsigned long jiffies_force_qs;		/* Time at which to invoke */
 						/*  force_quiescent_state(). */
@@ -342,8 +351,6 @@
 						/*  a reluctant CPU. */
 	unsigned long n_force_qs_gpstart;	/* Snapshot of n_force_qs at */
 						/*  GP start. */
-	unsigned long gp_max;			/* Maximum GP duration in */
-						/*  jiffies. */
 	const char *name;			/* Name of structure. */
 	char abbr;				/* Abbreviated name. */
 
@@ -355,6 +362,7 @@
 /* Values for rcu_state structure's gp_flags field. */
 #define RCU_GP_FLAG_INIT 0x1	/* Need grace-period initialization. */
 #define RCU_GP_FLAG_FQS  0x2	/* Need grace-period quiescent-state forcing. */
+#define RCU_GP_FLAG_OVLD 0x4	/* Experiencing callback overload. */
 
 /* Values for rcu_state structure's gp_state field. */
 #define RCU_GP_IDLE	 0	/* Initial state and no GP in progress. */
@@ -367,18 +375,6 @@
 #define RCU_GP_CLEANUP   7	/* Grace-period cleanup started. */
 #define RCU_GP_CLEANED   8	/* Grace-period cleanup complete. */
 
-static const char * const gp_state_names[] = {
-	"RCU_GP_IDLE",
-	"RCU_GP_WAIT_GPS",
-	"RCU_GP_DONE_GPS",
-	"RCU_GP_ONOFF",
-	"RCU_GP_INIT",
-	"RCU_GP_WAIT_FQS",
-	"RCU_GP_DOING_FQS",
-	"RCU_GP_CLEANUP",
-	"RCU_GP_CLEANED",
-};
-
 /*
  * In order to export the rcu_state name to the tracing tools, it
  * needs to be added in the __tracepoint_string section.
@@ -402,8 +398,6 @@
 #define RCU_NAME rcu_name
 #endif /* #else #ifdef CONFIG_TRACING */
 
-int rcu_dynticks_snap(struct rcu_data *rdp);
-
 /* Forward declarations for tree_plugin.h */
 static void rcu_bootup_announce(void);
 static void rcu_qs(void);
@@ -414,7 +408,6 @@
 static int rcu_print_task_exp_stall(struct rcu_node *rnp);
 static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
 static void rcu_flavor_sched_clock_irq(int user);
-void call_rcu(struct rcu_head *head, rcu_callback_t func);
 static void dump_blkd_tasks(struct rcu_node *rnp, int ncheck);
 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
 static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
@@ -465,6 +458,8 @@
 static bool rcu_nohz_full_cpu(void);
 static void rcu_dynticks_task_enter(void);
 static void rcu_dynticks_task_exit(void);
+static void rcu_dynticks_task_trace_enter(void);
+static void rcu_dynticks_task_trace_exit(void);
 
 /* Forward declarations for tree_stall.h */
 static void record_gp_stall_check_time(void);
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index df90d4d..0dc1634 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -21,7 +21,7 @@
 }
 
 /*
- * Return then value that expedited-grace-period counter will have
+ * Return the value that the expedited-grace-period counter will have
  * at the end of the current grace period.
  */
 static __maybe_unused unsigned long rcu_exp_gp_seq_endval(void)
@@ -39,7 +39,9 @@
 }
 
 /*
- * Take a snapshot of the expedited-grace-period counter.
+ * Take a snapshot of the expedited-grace-period counter, which is the
+ * earliest value that will indicate that a full grace period has
+ * elapsed since the current time.
  */
 static unsigned long rcu_exp_gp_seq_snap(void)
 {
@@ -143,31 +145,26 @@
  * Return non-zero if there is no RCU expedited grace period in progress
  * for the specified rcu_node structure, in other words, if all CPUs and
  * tasks covered by the specified rcu_node structure have done their bit
- * for the current expedited grace period.  Works only for preemptible
- * RCU -- other RCU implementation use other means.
- *
- * Caller must hold the specificed rcu_node structure's ->lock
+ * for the current expedited grace period.
  */
-static bool sync_rcu_preempt_exp_done(struct rcu_node *rnp)
+static bool sync_rcu_exp_done(struct rcu_node *rnp)
 {
 	raw_lockdep_assert_held_rcu_node(rnp);
-
-	return rnp->exp_tasks == NULL &&
+	return READ_ONCE(rnp->exp_tasks) == NULL &&
 	       READ_ONCE(rnp->expmask) == 0;
 }
 
 /*
- * Like sync_rcu_preempt_exp_done(), but this function assumes the caller
- * doesn't hold the rcu_node's ->lock, and will acquire and release the lock
- * itself
+ * Like sync_rcu_exp_done(), but where the caller does not hold the
+ * rcu_node's ->lock.
  */
-static bool sync_rcu_preempt_exp_done_unlocked(struct rcu_node *rnp)
+static bool sync_rcu_exp_done_unlocked(struct rcu_node *rnp)
 {
 	unsigned long flags;
 	bool ret;
 
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
-	ret = sync_rcu_preempt_exp_done(rnp);
+	ret = sync_rcu_exp_done(rnp);
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 	return ret;
@@ -181,8 +178,6 @@
  * which the task was queued or to one of that rcu_node structure's ancestors,
  * recursively up the tree.  (Calm down, calm down, we do the recursion
  * iteratively!)
- *
- * Caller must hold the specified rcu_node structure's ->lock.
  */
 static void __rcu_report_exp_rnp(struct rcu_node *rnp,
 				 bool wake, unsigned long flags)
@@ -190,8 +185,9 @@
 {
 	unsigned long mask;
 
+	raw_lockdep_assert_held_rcu_node(rnp);
 	for (;;) {
-		if (!sync_rcu_preempt_exp_done(rnp)) {
+		if (!sync_rcu_exp_done(rnp)) {
 			if (!rnp->expmask)
 				rcu_initiate_boost(rnp, flags);
 			else
@@ -234,7 +230,9 @@
 static void rcu_report_exp_cpu_mult(struct rcu_node *rnp,
 				    unsigned long mask, bool wake)
 {
+	int cpu;
 	unsigned long flags;
+	struct rcu_data *rdp;
 
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	if (!(rnp->expmask & mask)) {
@@ -242,6 +240,13 @@
 		return;
 	}
 	WRITE_ONCE(rnp->expmask, rnp->expmask & ~mask);
+	for_each_leaf_node_cpu_mask(rnp, cpu, mask) {
+		rdp = per_cpu_ptr(&rcu_data, cpu);
+		if (!IS_ENABLED(CONFIG_NO_HZ_FULL) || !rdp->rcu_forced_tick_exp)
+			continue;
+		rdp->rcu_forced_tick_exp = false;
+		tick_dep_clear_cpu(cpu, TICK_DEP_BIT_RCU_EXP);
+	}
 	__rcu_report_exp_rnp(rnp, wake, flags); /* Releases rnp->lock. */
 }
 
@@ -309,7 +314,7 @@
 				   sync_exp_work_done(s));
 			return true;
 		}
-		rnp->exp_seq_rq = s; /* Followers can wait on us. */
+		WRITE_ONCE(rnp->exp_seq_rq, s); /* Followers can wait on us. */
 		spin_unlock(&rnp->exp_lock);
 		trace_rcu_exp_funnel_lock(rcu_state.name, rnp->level,
 					  rnp->grplo, rnp->grphi, TPS("nxtlvl"));
@@ -345,8 +350,8 @@
 	/* Each pass checks a CPU for identity, offline, and idle. */
 	mask_ofl_test = 0;
 	for_each_leaf_node_cpu_mask(rnp, cpu, rnp->expmask) {
-		unsigned long mask = leaf_node_cpu_bit(rnp, cpu);
 		struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
+		unsigned long mask = rdp->grpmask;
 		int snap;
 
 		if (raw_smp_processor_id() == cpu ||
@@ -368,13 +373,13 @@
 	 * until such time as the ->expmask bits are cleared.
 	 */
 	if (rcu_preempt_has_tasks(rnp))
-		rnp->exp_tasks = rnp->blkd_tasks.next;
+		WRITE_ONCE(rnp->exp_tasks, rnp->blkd_tasks.next);
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 	/* IPI the remaining CPUs for expedited quiescent state. */
 	for_each_leaf_node_cpu_mask(rnp, cpu, mask_ofl_ipi) {
-		unsigned long mask = leaf_node_cpu_bit(rnp, cpu);
 		struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
+		unsigned long mask = rdp->grpmask;
 
 retry_ipi:
 		if (rcu_dynticks_in_eqs_since(rdp, rdp->exp_dynticks_snap)) {
@@ -382,15 +387,16 @@
 			continue;
 		}
 		if (get_cpu() == cpu) {
+			mask_ofl_test |= mask;
 			put_cpu();
 			continue;
 		}
 		ret = smp_call_function_single(cpu, rcu_exp_handler, NULL, 0);
 		put_cpu();
-		if (!ret) {
-			mask_ofl_ipi &= ~mask;
+		/* The CPU will report the QS in response to the IPI. */
+		if (!ret)
 			continue;
-		}
+
 		/* Failed, raced with CPU hotplug operation. */
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
 		if ((rnp->qsmaskinitnext & mask) &&
@@ -398,16 +404,15 @@
 			/* Online, so delay for a bit and try again. */
 			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 			trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("selectofl"));
-			schedule_timeout_uninterruptible(1);
+			schedule_timeout_idle(1);
 			goto retry_ipi;
 		}
-		/* CPU really is offline, so we can ignore it. */
-		if (!(rnp->expmask & mask))
-			mask_ofl_ipi &= ~mask;
+		/* CPU really is offline, so we must report its QS. */
+		if (rnp->expmask & mask)
+			mask_ofl_test |= mask;
 		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	}
 	/* Report quiescent states for those that went offline. */
-	mask_ofl_test |= mask_ofl_ipi;
 	if (mask_ofl_test)
 		rcu_report_exp_cpu_mult(rnp, mask_ofl_test, false);
 }
@@ -454,30 +459,67 @@
 			flush_work(&rnp->rew.rew_work);
 }
 
-static void synchronize_sched_expedited_wait(void)
+/*
+ * Wait for the expedited grace period to elapse, within time limit.
+ * If the time limit is exceeded without the grace period elapsing,
+ * return false, otherwise return true.
+ */
+static bool synchronize_rcu_expedited_wait_once(long tlimit)
+{
+	int t;
+	struct rcu_node *rnp_root = rcu_get_root();
+
+	t = swait_event_timeout_exclusive(rcu_state.expedited_wq,
+					  sync_rcu_exp_done_unlocked(rnp_root),
+					  tlimit);
+	// Workqueues should not be signaled.
+	if (t > 0 || sync_rcu_exp_done_unlocked(rnp_root))
+		return true;
+	WARN_ON(t < 0);  /* workqueues should not be signaled. */
+	return false;
+}
+
+/*
+ * Wait for the expedited grace period to elapse, issuing any needed
+ * RCU CPU stall warnings along the way.
+ */
+static void synchronize_rcu_expedited_wait(void)
 {
 	int cpu;
+	unsigned long j;
 	unsigned long jiffies_stall;
 	unsigned long jiffies_start;
 	unsigned long mask;
 	int ndetected;
+	struct rcu_data *rdp;
 	struct rcu_node *rnp;
 	struct rcu_node *rnp_root = rcu_get_root();
-	int ret;
 
 	trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("startwait"));
 	jiffies_stall = rcu_jiffies_till_stall_check();
 	jiffies_start = jiffies;
+	if (tick_nohz_full_enabled() && rcu_inkernel_boot_has_ended()) {
+		if (synchronize_rcu_expedited_wait_once(1))
+			return;
+		rcu_for_each_leaf_node(rnp) {
+			for_each_leaf_node_cpu_mask(rnp, cpu, rnp->expmask) {
+				rdp = per_cpu_ptr(&rcu_data, cpu);
+				if (rdp->rcu_forced_tick_exp)
+					continue;
+				rdp->rcu_forced_tick_exp = true;
+				tick_dep_set_cpu(cpu, TICK_DEP_BIT_RCU_EXP);
+			}
+		}
+		j = READ_ONCE(jiffies_till_first_fqs);
+		if (synchronize_rcu_expedited_wait_once(j + HZ))
+			return;
+		WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_RT));
+	}
 
 	for (;;) {
-		ret = swait_event_timeout_exclusive(
-				rcu_state.expedited_wq,
-				sync_rcu_preempt_exp_done_unlocked(rnp_root),
-				jiffies_stall);
-		if (ret > 0 || sync_rcu_preempt_exp_done_unlocked(rnp_root))
+		if (synchronize_rcu_expedited_wait_once(jiffies_stall))
 			return;
-		WARN_ON(ret < 0);  /* workqueues should not be signaled. */
-		if (rcu_cpu_stall_suppress)
+		if (rcu_stall_is_suppressed())
 			continue;
 		panic_on_rcu_stall();
 		pr_err("INFO: %s detected expedited stalls on CPUs/tasks: {",
@@ -501,19 +543,19 @@
 		}
 		pr_cont(" } %lu jiffies s: %lu root: %#lx/%c\n",
 			jiffies - jiffies_start, rcu_state.expedited_sequence,
-			READ_ONCE(rnp_root->expmask),
-			".T"[!!rnp_root->exp_tasks]);
+			data_race(rnp_root->expmask),
+			".T"[!!data_race(rnp_root->exp_tasks)]);
 		if (ndetected) {
 			pr_err("blocking rcu_node structures:");
 			rcu_for_each_node_breadth_first(rnp) {
 				if (rnp == rnp_root)
 					continue; /* printed unconditionally */
-				if (sync_rcu_preempt_exp_done_unlocked(rnp))
+				if (sync_rcu_exp_done_unlocked(rnp))
 					continue;
 				pr_cont(" l=%u:%d-%d:%#lx/%c",
 					rnp->level, rnp->grplo, rnp->grphi,
-					READ_ONCE(rnp->expmask),
-					".T"[!!rnp->exp_tasks]);
+					data_race(rnp->expmask),
+					".T"[!!data_race(rnp->exp_tasks)]);
 			}
 			pr_cont("\n");
 		}
@@ -539,7 +581,7 @@
 {
 	struct rcu_node *rnp;
 
-	synchronize_sched_expedited_wait();
+	synchronize_rcu_expedited_wait();
 
 	// Switch over to wakeup mode, allowing the next GP to proceed.
 	// End the previous grace period only after acquiring the mutex
@@ -553,7 +595,7 @@
 			spin_lock(&rnp->exp_lock);
 			/* Recheck, avoid hang in case someone just arrived. */
 			if (ULONG_CMP_LT(rnp->exp_seq_rq, s))
-				rnp->exp_seq_rq = s;
+				WRITE_ONCE(rnp->exp_seq_rq, s);
 			spin_unlock(&rnp->exp_lock);
 		}
 		smp_mb(); /* All above changes before wakeup. */
@@ -598,6 +640,7 @@
  */
 static void rcu_exp_handler(void *unused)
 {
+	int depth = rcu_preempt_depth();
 	unsigned long flags;
 	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 	struct rcu_node *rnp = rdp->mynode;
@@ -608,7 +651,7 @@
 	 * critical section.  If also enabled or idle, immediately
 	 * report the quiescent state, otherwise defer.
 	 */
-	if (!t->rcu_read_lock_nesting) {
+	if (!depth) {
 		if (!(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK)) ||
 		    rcu_dynticks_curr_cpu_in_eqs()) {
 			rcu_report_exp_rdp(rdp);
@@ -632,7 +675,7 @@
 	 * can have caused this quiescent state to already have been
 	 * reported, so we really do need to check ->expmask.
 	 */
-	if (t->rcu_read_lock_nesting > 0) {
+	if (depth > 0) {
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
 		if (rnp->expmask & rdp->grpmask) {
 			rdp->exp_deferred_qs = true;
@@ -642,33 +685,11 @@
 		return;
 	}
 
-	/*
-	 * The final and least likely case is where the interrupted
-	 * code was just about to or just finished exiting the RCU-preempt
-	 * read-side critical section, and no, we can't tell which.
-	 * So either way, set ->deferred_qs to flag later code that
-	 * a quiescent state is required.
-	 *
-	 * If the CPU is fully enabled (or if some buggy RCU-preempt
-	 * read-side critical section is being used from idle), just
-	 * invoke rcu_preempt_deferred_qs() to immediately report the
-	 * quiescent state.  We cannot use rcu_read_unlock_special()
-	 * because we are in an interrupt handler, which will cause that
-	 * function to take an early exit without doing anything.
-	 *
-	 * Otherwise, force a context switch after the CPU enables everything.
-	 */
-	rdp->exp_deferred_qs = true;
-	if (!(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK)) ||
-	    WARN_ON_ONCE(rcu_dynticks_curr_cpu_in_eqs())) {
-		rcu_preempt_deferred_qs(t);
-	} else {
-		set_tsk_need_resched(t);
-		set_preempt_need_resched();
-	}
+	// Finally, negative nesting depth should not happen.
+	WARN_ON_ONCE(1);
 }
 
-/* PREEMPT=y, so no PREEMPT=n expedited grace period to clean up after. */
+/* PREEMPTION=y, so no PREEMPTION=n expedited grace period to clean up after. */
 static void sync_sched_exp_online_cleanup(int cpu)
 {
 }
@@ -680,17 +701,20 @@
  */
 static int rcu_print_task_exp_stall(struct rcu_node *rnp)
 {
-	struct task_struct *t;
+	unsigned long flags;
 	int ndetected = 0;
+	struct task_struct *t;
 
-	if (!rnp->exp_tasks)
+	if (!READ_ONCE(rnp->exp_tasks))
 		return 0;
+	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	t = list_entry(rnp->exp_tasks->prev,
 		       struct task_struct, rcu_node_entry);
 	list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) {
 		pr_cont(" P%d", t->pid);
 		ndetected++;
 	}
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	return ndetected;
 }
 
@@ -709,11 +733,9 @@
 /* Invoked on each online non-idle CPU for expedited quiescent state. */
 static void rcu_exp_handler(void *unused)
 {
-	struct rcu_data *rdp;
-	struct rcu_node *rnp;
+	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
+	struct rcu_node *rnp = rdp->mynode;
 
-	rdp = this_cpu_ptr(&rcu_data);
-	rnp = rdp->mynode;
 	if (!(READ_ONCE(rnp->expmask) & rdp->grpmask) ||
 	    __this_cpu_read(rcu_data.cpu_no_qs.b.exp))
 		return;
@@ -738,7 +760,7 @@
 	my_cpu = get_cpu();
 	/* Quiescent state either not needed or already requested, leave. */
 	if (!(READ_ONCE(rnp->expmask) & rdp->grpmask) ||
-	    __this_cpu_read(rcu_data.cpu_no_qs.b.exp)) {
+	    rdp->cpu_no_qs.b.exp) {
 		put_cpu();
 		return;
 	}
@@ -783,7 +805,7 @@
  * implementations, it is still unfriendly to real-time workloads, so is
  * thus not recommended for any sort of common-case code.  In fact, if
  * you are using synchronize_rcu_expedited() in a loop, please restructure
- * your code to batch your updates, and then Use a single synchronize_rcu()
+ * your code to batch your updates, and then use a single synchronize_rcu()
  * instead.
  *
  * This has the same semantics as (but is more brutal than) synchronize_rcu().
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index a71a4a2..f5ba074 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -36,6 +36,8 @@
 		pr_info("\tRCU dyntick-idle grace-period acceleration is enabled.\n");
 	if (IS_ENABLED(CONFIG_PROVE_RCU))
 		pr_info("\tRCU lockdep checking is enabled.\n");
+	if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD))
+		pr_info("\tRCU strict (and thus non-scalable) grace periods enabled.\n");
 	if (RCU_NUM_LVLS >= 4)
 		pr_info("\tFour(or more)-level hierarchy is enabled.\n");
 	if (RCU_FANOUT_LEAF != 16)
@@ -56,6 +58,8 @@
 		pr_info("\tBoot-time adjustment of callback high-water mark to %ld.\n", qhimark);
 	if (qlowmark != DEFAULT_RCU_QLOMARK)
 		pr_info("\tBoot-time adjustment of callback low-water mark to %ld.\n", qlowmark);
+	if (qovld != DEFAULT_RCU_QOVLD)
+		pr_info("\tBoot-time adjustment of callback overload level to %ld.\n", qovld);
 	if (jiffies_till_first_fqs != ULONG_MAX)
 		pr_info("\tBoot-time adjustment of first FQS scan delay to %ld jiffies.\n", jiffies_till_first_fqs);
 	if (jiffies_till_next_fqs != ULONG_MAX)
@@ -224,7 +228,7 @@
 		WARN_ON_ONCE(rnp->completedqs == rnp->gp_seq);
 	}
 	if (!rnp->exp_tasks && (blkd_state & RCU_EXP_BLKD))
-		rnp->exp_tasks = &t->rcu_node_entry;
+		WRITE_ONCE(rnp->exp_tasks, &t->rcu_node_entry);
 	WARN_ON_ONCE(!(blkd_state & RCU_GP_BLKD) !=
 		     !(rnp->qsmask & rdp->grpmask));
 	WARN_ON_ONCE(!(blkd_state & RCU_EXP_BLKD) !=
@@ -290,8 +294,8 @@
 
 	trace_rcu_utilization(TPS("Start context switch"));
 	lockdep_assert_irqs_disabled();
-	WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0);
-	if (t->rcu_read_lock_nesting > 0 &&
+	WARN_ON_ONCE(!preempt && rcu_preempt_depth() > 0);
+	if (rcu_preempt_depth() > 0 &&
 	    !t->rcu_read_unlock_special.b.blocked) {
 
 		/* Possibly blocking in an RCU read-side critical section. */
@@ -329,6 +333,7 @@
 	rcu_qs();
 	if (rdp->exp_deferred_qs)
 		rcu_report_exp_rdp(rdp);
+	rcu_tasks_qs(current, preempt);
 	trace_rcu_utilization(TPS("End context switch"));
 }
 EXPORT_SYMBOL_GPL(rcu_note_context_switch);
@@ -343,11 +348,24 @@
 	return READ_ONCE(rnp->gp_tasks) != NULL;
 }
 
-/* Bias and limit values for ->rcu_read_lock_nesting. */
-#define RCU_NEST_BIAS INT_MAX
-#define RCU_NEST_NMAX (-INT_MAX / 2)
+/* limit value for ->rcu_read_lock_nesting. */
 #define RCU_NEST_PMAX (INT_MAX / 2)
 
+static void rcu_preempt_read_enter(void)
+{
+	current->rcu_read_lock_nesting++;
+}
+
+static int rcu_preempt_read_exit(void)
+{
+	return --current->rcu_read_lock_nesting;
+}
+
+static void rcu_preempt_depth_set(int val)
+{
+	current->rcu_read_lock_nesting = val;
+}
+
 /*
  * Preemptible RCU implementation for rcu_read_lock().
  * Just increment ->rcu_read_lock_nesting, shared state will be updated
@@ -355,9 +373,11 @@
  */
 void __rcu_read_lock(void)
 {
-	current->rcu_read_lock_nesting++;
+	rcu_preempt_read_enter();
 	if (IS_ENABLED(CONFIG_PROVE_LOCKING))
-		WARN_ON_ONCE(current->rcu_read_lock_nesting > RCU_NEST_PMAX);
+		WARN_ON_ONCE(rcu_preempt_depth() > RCU_NEST_PMAX);
+	if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) && rcu_state.gp_kthread)
+		WRITE_ONCE(current->rcu_read_unlock_special.b.need_qs, true);
 	barrier();  /* critical section after entry code. */
 }
 EXPORT_SYMBOL_GPL(__rcu_read_lock);
@@ -373,21 +393,15 @@
 {
 	struct task_struct *t = current;
 
-	if (t->rcu_read_lock_nesting != 1) {
-		--t->rcu_read_lock_nesting;
-	} else {
+	if (rcu_preempt_read_exit() == 0) {
 		barrier();  /* critical section before exit code. */
-		t->rcu_read_lock_nesting = -RCU_NEST_BIAS;
-		barrier();  /* assign before ->rcu_read_unlock_special load */
 		if (unlikely(READ_ONCE(t->rcu_read_unlock_special.s)))
 			rcu_read_unlock_special(t);
-		barrier();  /* ->rcu_read_unlock_special load before assign */
-		t->rcu_read_lock_nesting = 0;
 	}
 	if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
-		int rrln = t->rcu_read_lock_nesting;
+		int rrln = rcu_preempt_depth();
 
-		WARN_ON_ONCE(rrln < 0 && rrln > RCU_NEST_NMAX);
+		WARN_ON_ONCE(rrln < 0 || rrln > RCU_NEST_PMAX);
 	}
 }
 EXPORT_SYMBOL_GPL(__rcu_read_unlock);
@@ -444,13 +458,13 @@
 		local_irq_restore(flags);
 		return;
 	}
-	t->rcu_read_unlock_special.b.deferred_qs = false;
+	t->rcu_read_unlock_special.s = 0;
 	if (special.b.need_qs) {
-		rcu_qs();
-		t->rcu_read_unlock_special.b.need_qs = false;
-		if (!t->rcu_read_unlock_special.s && !rdp->exp_deferred_qs) {
-			local_irq_restore(flags);
-			return;
+		if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD)) {
+			rcu_report_qs_rdp(rdp);
+			udelay(rcu_unlock_delay);
+		} else {
+			rcu_qs();
 		}
 	}
 
@@ -460,17 +474,11 @@
 	 * tasks are handled when removing the task from the
 	 * blocked-tasks list below.
 	 */
-	if (rdp->exp_deferred_qs) {
+	if (rdp->exp_deferred_qs)
 		rcu_report_exp_rdp(rdp);
-		if (!t->rcu_read_unlock_special.s) {
-			local_irq_restore(flags);
-			return;
-		}
-	}
 
 	/* Clean up if blocked during RCU read-side critical section. */
 	if (special.b.blocked) {
-		t->rcu_read_unlock_special.b.blocked = false;
 
 		/*
 		 * Remove this task from the list it blocked on.  The task
@@ -485,7 +493,7 @@
 		empty_norm = !rcu_preempt_blocked_readers_cgp(rnp);
 		WARN_ON_ONCE(rnp->completedqs == rnp->gp_seq &&
 			     (!empty_norm || rnp->qsmask));
-		empty_exp = sync_rcu_preempt_exp_done(rnp);
+		empty_exp = sync_rcu_exp_done(rnp);
 		smp_mb(); /* ensure expedited fastpath sees end of RCU c-s. */
 		np = rcu_next_node_entry(t, rnp);
 		list_del_init(&t->rcu_node_entry);
@@ -495,12 +503,12 @@
 		if (&t->rcu_node_entry == rnp->gp_tasks)
 			WRITE_ONCE(rnp->gp_tasks, np);
 		if (&t->rcu_node_entry == rnp->exp_tasks)
-			rnp->exp_tasks = np;
+			WRITE_ONCE(rnp->exp_tasks, np);
 		if (IS_ENABLED(CONFIG_RCU_BOOST)) {
 			/* Snapshot ->boost_mtx ownership w/rnp->lock held. */
 			drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx) == t;
 			if (&t->rcu_node_entry == rnp->boost_tasks)
-				rnp->boost_tasks = np;
+				WRITE_ONCE(rnp->boost_tasks, np);
 		}
 
 		/*
@@ -509,7 +517,7 @@
 		 * Note that rcu_report_unblock_qs_rnp() releases rnp->lock,
 		 * so we must take a snapshot of the expedited state.
 		 */
-		empty_exp_now = sync_rcu_preempt_exp_done(rnp);
+		empty_exp_now = sync_rcu_exp_done(rnp);
 		if (!empty_norm && !rcu_preempt_blocked_readers_cgp(rnp)) {
 			trace_rcu_quiescent_state_report(TPS("preempt_rcu"),
 							 rnp->gp_seq,
@@ -523,16 +531,17 @@
 			raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		}
 
-		/* Unboost if we were boosted. */
-		if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex)
-			rt_mutex_futex_unlock(&rnp->boost_mtx);
-
 		/*
 		 * If this was the last task on the expedited lists,
 		 * then we need to report up the rcu_node hierarchy.
 		 */
 		if (!empty_exp && empty_exp_now)
 			rcu_report_exp_rnp(rnp, true);
+
+		/* Unboost if we were boosted. */
+		if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex)
+			rt_mutex_futex_unlock(&rnp->boost_mtx);
+
 	} else {
 		local_irq_restore(flags);
 	}
@@ -551,7 +560,7 @@
 {
 	return (__this_cpu_read(rcu_data.exp_deferred_qs) ||
 		READ_ONCE(t->rcu_read_unlock_special.s)) &&
-	       t->rcu_read_lock_nesting <= 0;
+	       rcu_preempt_depth() == 0;
 }
 
 /*
@@ -564,16 +573,11 @@
 static void rcu_preempt_deferred_qs(struct task_struct *t)
 {
 	unsigned long flags;
-	bool couldrecurse = t->rcu_read_lock_nesting >= 0;
 
 	if (!rcu_preempt_need_deferred_qs(t))
 		return;
-	if (couldrecurse)
-		t->rcu_read_lock_nesting -= RCU_NEST_BIAS;
 	local_irq_save(flags);
 	rcu_preempt_deferred_qs_irqrestore(t, flags);
-	if (couldrecurse)
-		t->rcu_read_lock_nesting += RCU_NEST_BIAS;
 }
 
 /*
@@ -610,24 +614,22 @@
 		struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
 		struct rcu_node *rnp = rdp->mynode;
 
-		t->rcu_read_unlock_special.b.exp_hint = false;
-		exp = (t->rcu_blocked_node && t->rcu_blocked_node->exp_tasks) ||
-		      (rdp->grpmask & READ_ONCE(rnp->expmask)) ||
-		      tick_nohz_full_cpu(rdp->cpu);
+		exp = (t->rcu_blocked_node &&
+		       READ_ONCE(t->rcu_blocked_node->exp_tasks)) ||
+		      (rdp->grpmask & READ_ONCE(rnp->expmask));
 		// Need to defer quiescent state until everything is enabled.
-		if (irqs_were_disabled && use_softirq &&
-		    (in_interrupt() ||
-		     (exp && !t->rcu_read_unlock_special.b.deferred_qs))) {
-			// Using softirq, safe to awaken, and we get
-			// no help from enabling irqs, unlike bh/preempt.
+		if (use_softirq && (in_irq() || (exp && !irqs_were_disabled))) {
+			// Using softirq, safe to awaken, and either the
+			// wakeup is free or there is an expedited GP.
 			raise_softirq_irqoff(RCU_SOFTIRQ);
 		} else {
 			// Enabling BH or preempt does reschedule, so...
-			// Also if no expediting or NO_HZ_FULL, slow is OK.
+			// Also if no expediting, slow is OK.
+			// Plus nohz_full CPUs eventually get tick enabled.
 			set_tsk_need_resched(current);
 			set_preempt_need_resched();
 			if (IS_ENABLED(CONFIG_IRQ_WORK) && irqs_were_disabled &&
-			    !rdp->defer_qs_iw_pending && exp) {
+			    !rdp->defer_qs_iw_pending && exp && cpu_online(rdp->cpu)) {
 				// Get scheduler to re-evaluate and call hooks.
 				// If !IRQ_WORK, FQS scan will eventually IPI.
 				init_irq_work(&rdp->defer_qs_iw,
@@ -636,11 +638,9 @@
 				irq_work_queue_on(&rdp->defer_qs_iw, rdp->cpu);
 			}
 		}
-		t->rcu_read_unlock_special.b.deferred_qs = true;
 		local_irq_restore(flags);
 		return;
 	}
-	WRITE_ONCE(t->rcu_read_unlock_special.b.exp_hint, false);
 	rcu_preempt_deferred_qs_irqrestore(t, flags);
 }
 
@@ -648,8 +648,7 @@
  * Check that the list of blocked tasks for the newly completed grace
  * period is in fact empty.  It is a serious bug to complete a grace
  * period that still has RCU readers blocked!  This function must be
- * invoked -before- updating this rnp's ->gp_seq, and the rnp's ->lock
- * must be held by the caller.
+ * invoked -before- updating this rnp's ->gp_seq.
  *
  * Also, if there are blocked tasks on the list, they automatically
  * block the newly created grace period, so set up ->gp_tasks accordingly.
@@ -659,6 +658,7 @@
 	struct task_struct *t;
 
 	RCU_LOCKDEP_WARN(preemptible(), "rcu_preempt_check_blocked_tasks() invoked with preemption enabled!!!\n");
+	raw_lockdep_assert_held_rcu_node(rnp);
 	if (WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)))
 		dump_blkd_tasks(rnp, 10);
 	if (rcu_preempt_has_tasks(rnp) &&
@@ -683,10 +683,11 @@
 {
 	struct task_struct *t = current;
 
+	lockdep_assert_irqs_disabled();
 	if (user || rcu_is_cpu_rrupt_from_idle()) {
 		rcu_note_voluntary_context_switch(current);
 	}
-	if (t->rcu_read_lock_nesting > 0 ||
+	if (rcu_preempt_depth() > 0 ||
 	    (preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK))) {
 		/* No QS, force context switch if deferred. */
 		if (rcu_preempt_need_deferred_qs(t)) {
@@ -696,13 +697,13 @@
 	} else if (rcu_preempt_need_deferred_qs(t)) {
 		rcu_preempt_deferred_qs(t); /* Report deferred QS. */
 		return;
-	} else if (!t->rcu_read_lock_nesting) {
+	} else if (!WARN_ON_ONCE(rcu_preempt_depth())) {
 		rcu_qs(); /* Report immediate QS. */
 		return;
 	}
 
 	/* If GP is oldish, ask for help from rcu_read_unlock_special(). */
-	if (t->rcu_read_lock_nesting > 0 &&
+	if (rcu_preempt_depth() > 0 &&
 	    __this_cpu_read(rcu_data.core_needs_qs) &&
 	    __this_cpu_read(rcu_data.cpu_no_qs.b.norm) &&
 	    !t->rcu_read_unlock_special.b.need_qs &&
@@ -723,11 +724,11 @@
 	struct task_struct *t = current;
 
 	if (unlikely(!list_empty(&current->rcu_node_entry))) {
-		t->rcu_read_lock_nesting = 1;
+		rcu_preempt_depth_set(1);
 		barrier();
 		WRITE_ONCE(t->rcu_read_unlock_special.b.blocked, true);
-	} else if (unlikely(t->rcu_read_lock_nesting)) {
-		t->rcu_read_lock_nesting = 1;
+	} else if (unlikely(rcu_preempt_depth())) {
+		rcu_preempt_depth_set(1);
 	} else {
 		return;
 	}
@@ -752,13 +753,13 @@
 	raw_lockdep_assert_held_rcu_node(rnp);
 	pr_info("%s: grp: %d-%d level: %d ->gp_seq %ld ->completedqs %ld\n",
 		__func__, rnp->grplo, rnp->grphi, rnp->level,
-		(long)rnp->gp_seq, (long)rnp->completedqs);
+		(long)READ_ONCE(rnp->gp_seq), (long)rnp->completedqs);
 	for (rnp1 = rnp; rnp1; rnp1 = rnp1->parent)
 		pr_info("%s: %d:%d ->qsmask %#lx ->qsmaskinit %#lx ->qsmaskinitnext %#lx\n",
 			__func__, rnp1->grplo, rnp1->grphi, rnp1->qsmask, rnp1->qsmaskinit, rnp1->qsmaskinitnext);
 	pr_info("%s: ->gp_tasks %p ->boost_tasks %p ->exp_tasks %p\n",
-		__func__, READ_ONCE(rnp->gp_tasks), rnp->boost_tasks,
-		rnp->exp_tasks);
+		__func__, READ_ONCE(rnp->gp_tasks), data_race(rnp->boost_tasks),
+		READ_ONCE(rnp->exp_tasks));
 	pr_info("%s: ->blkd_tasks", __func__);
 	i = 0;
 	list_for_each(lhp, &rnp->blkd_tasks) {
@@ -780,6 +781,24 @@
 #else /* #ifdef CONFIG_PREEMPT_RCU */
 
 /*
+ * If strict grace periods are enabled, and if the calling
+ * __rcu_read_unlock() marks the beginning of a quiescent state, immediately
+ * report that quiescent state and, if requested, spin for a bit.
+ */
+void rcu_read_unlock_strict(void)
+{
+	struct rcu_data *rdp;
+
+	if (!IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) ||
+	   irqs_disabled() || preempt_count() || !rcu_state.gp_kthread)
+		return;
+	rdp = this_cpu_ptr(&rcu_data);
+	rcu_report_qs_rdp(rdp);
+	udelay(rcu_unlock_delay);
+}
+EXPORT_SYMBOL_GPL(rcu_read_unlock_strict);
+
+/*
  * Tell them what RCU they are running.
  */
 static void __init rcu_bootup_announce(void)
@@ -789,7 +808,7 @@
 }
 
 /*
- * Note a quiescent state for PREEMPT=n.  Because we do not need to know
+ * Note a quiescent state for PREEMPTION=n.  Because we do not need to know
  * how many quiescent states passed, just if there was at least one since
  * the start of the grace period, this just sets a flag.  The caller must
  * have disabled preemption.
@@ -839,7 +858,7 @@
 EXPORT_SYMBOL_GPL(rcu_all_qs);
 
 /*
- * Note a PREEMPT=n context switch.  The caller must have disabled interrupts.
+ * Note a PREEMPTION=n context switch. The caller must have disabled interrupts.
  */
 void rcu_note_context_switch(bool preempt)
 {
@@ -851,8 +870,7 @@
 	this_cpu_write(rcu_data.rcu_urgent_qs, false);
 	if (unlikely(raw_cpu_read(rcu_data.rcu_need_heavy_qs)))
 		rcu_momentary_dyntick_idle();
-	if (!preempt)
-		rcu_tasks_qs(current);
+	rcu_tasks_qs(current, preempt);
 out:
 	trace_rcu_utilization(TPS("End context switch"));
 }
@@ -1031,20 +1049,21 @@
 
 	trace_rcu_utilization(TPS("Start boost kthread@init"));
 	for (;;) {
-		rnp->boost_kthread_status = RCU_KTHREAD_WAITING;
+		WRITE_ONCE(rnp->boost_kthread_status, RCU_KTHREAD_WAITING);
 		trace_rcu_utilization(TPS("End boost kthread@rcu_wait"));
-		rcu_wait(rnp->boost_tasks || rnp->exp_tasks);
+		rcu_wait(READ_ONCE(rnp->boost_tasks) ||
+			 READ_ONCE(rnp->exp_tasks));
 		trace_rcu_utilization(TPS("Start boost kthread@rcu_wait"));
-		rnp->boost_kthread_status = RCU_KTHREAD_RUNNING;
+		WRITE_ONCE(rnp->boost_kthread_status, RCU_KTHREAD_RUNNING);
 		more2boost = rcu_boost(rnp);
 		if (more2boost)
 			spincnt++;
 		else
 			spincnt = 0;
 		if (spincnt > 10) {
-			rnp->boost_kthread_status = RCU_KTHREAD_YIELDING;
+			WRITE_ONCE(rnp->boost_kthread_status, RCU_KTHREAD_YIELDING);
 			trace_rcu_utilization(TPS("End boost kthread@rcu_yield"));
-			schedule_timeout_interruptible(2);
+			schedule_timeout_idle(2);
 			trace_rcu_utilization(TPS("Start boost kthread@rcu_yield"));
 			spincnt = 0;
 		}
@@ -1076,12 +1095,12 @@
 	    (rnp->gp_tasks != NULL &&
 	     rnp->boost_tasks == NULL &&
 	     rnp->qsmask == 0 &&
-	     ULONG_CMP_GE(jiffies, rnp->boost_time))) {
+	     (!time_after(rnp->boost_time, jiffies) || rcu_state.cbovld))) {
 		if (rnp->exp_tasks == NULL)
-			rnp->boost_tasks = rnp->gp_tasks;
+			WRITE_ONCE(rnp->boost_tasks, rnp->gp_tasks);
 		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		rcu_wake_cond(rnp->boost_kthread_task,
-			      rnp->boost_kthread_status);
+			      READ_ONCE(rnp->boost_kthread_status));
 	} else {
 		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	}
@@ -1263,10 +1282,9 @@
 /*
  * This code is invoked when a CPU goes idle, at which point we want
  * to have the CPU do everything required for RCU so that it can enter
- * the energy-efficient dyntick-idle mode.  This is handled by a
- * state machine implemented by rcu_prepare_for_idle() below.
+ * the energy-efficient dyntick-idle mode.
  *
- * The following three proprocessor symbols control this state machine:
+ * The following preprocessor symbol controls this:
  *
  * RCU_IDLE_GP_DELAY gives the number of jiffies that a CPU is permitted
  *	to sleep in dyntick-idle mode with RCU callbacks pending.  This
@@ -1275,21 +1293,15 @@
  *	number, be warned: Setting RCU_IDLE_GP_DELAY too high can hang your
  *	system.  And if you are -that- concerned about energy efficiency,
  *	just power the system down and be done with it!
- * RCU_IDLE_LAZY_GP_DELAY gives the number of jiffies that a CPU is
- *	permitted to sleep in dyntick-idle mode with only lazy RCU
- *	callbacks pending.  Setting this too high can OOM your system.
  *
- * The values below work well in practice.  If future workloads require
+ * The value below works well in practice.  If future workloads require
  * adjustment, they can be converted into kernel config parameters, though
  * making the state machine smarter might be a better option.
  */
 #define RCU_IDLE_GP_DELAY 4		/* Roughly one grace period. */
-#define RCU_IDLE_LAZY_GP_DELAY (6 * HZ)	/* Roughly six seconds. */
 
 static int rcu_idle_gp_delay = RCU_IDLE_GP_DELAY;
 module_param(rcu_idle_gp_delay, int, 0644);
-static int rcu_idle_lazy_gp_delay = RCU_IDLE_LAZY_GP_DELAY;
-module_param(rcu_idle_lazy_gp_delay, int, 0644);
 
 /*
  * Try to advance callbacks on the current CPU, but only if it has been
@@ -1328,8 +1340,7 @@
 /*
  * Allow the CPU to enter dyntick-idle mode unless it has callbacks ready
  * to invoke.  If the CPU has callbacks, try to advance them.  Tell the
- * caller to set the timeout based on whether or not there are non-lazy
- * callbacks.
+ * caller about what to set the timeout.
  *
  * The caller must have disabled interrupts.
  */
@@ -1355,25 +1366,18 @@
 	}
 	rdp->last_accelerate = jiffies;
 
-	/* Request timer delay depending on laziness, and round. */
-	rdp->all_lazy = !rcu_segcblist_n_nonlazy_cbs(&rdp->cblist);
-	if (rdp->all_lazy) {
-		dj = round_jiffies(rcu_idle_lazy_gp_delay + jiffies) - jiffies;
-	} else {
-		dj = round_up(rcu_idle_gp_delay + jiffies,
-			       rcu_idle_gp_delay) - jiffies;
-	}
+	/* Request timer and round. */
+	dj = round_up(rcu_idle_gp_delay + jiffies, rcu_idle_gp_delay) - jiffies;
+
 	*nextevt = basemono + dj * TICK_NSEC;
 	return 0;
 }
 
 /*
- * Prepare a CPU for idle from an RCU perspective.  The first major task
- * is to sense whether nohz mode has been enabled or disabled via sysfs.
- * The second major task is to check to see if a non-lazy callback has
- * arrived at a CPU that previously had only lazy callbacks.  The third
- * major task is to accelerate (that is, assign grace-period numbers to)
- * any recently arrived callbacks.
+ * Prepare a CPU for idle from an RCU perspective.  The first major task is to
+ * sense whether nohz mode has been enabled or disabled via sysfs.  The second
+ * major task is to accelerate (that is, assign grace-period numbers to) any
+ * recently arrived callbacks.
  *
  * The caller must have disabled interrupts.
  */
@@ -1400,17 +1404,6 @@
 		return;
 
 	/*
-	 * If a non-lazy callback arrived at a CPU having only lazy
-	 * callbacks, invoke RCU core for the side-effect of recalculating
-	 * idle duration on re-entry to idle.
-	 */
-	if (rdp->all_lazy && rcu_segcblist_n_nonlazy_cbs(&rdp->cblist)) {
-		rdp->all_lazy = false;
-		invoke_rcu_core();
-		return;
-	}
-
-	/*
 	 * If we have not yet accelerated this jiffy, accelerate all
 	 * callbacks on this CPU.
 	 */
@@ -1511,6 +1504,7 @@
  * flag the contention.
  */
 static void rcu_nocb_bypass_lock(struct rcu_data *rdp)
+	__acquires(&rdp->nocb_bypass_lock)
 {
 	lockdep_assert_irqs_disabled();
 	if (raw_spin_trylock(&rdp->nocb_bypass_lock))
@@ -1554,6 +1548,7 @@
  * Release the specified rcu_data structure's ->nocb_bypass_lock.
  */
 static void rcu_nocb_bypass_unlock(struct rcu_data *rdp)
+	__releases(&rdp->nocb_bypass_lock)
 {
 	lockdep_assert_irqs_disabled();
 	raw_spin_unlock(&rdp->nocb_bypass_lock);
@@ -1602,8 +1597,7 @@
 static void rcu_lockdep_assert_cblist_protected(struct rcu_data *rdp)
 {
 	lockdep_assert_irqs_disabled();
-	if (rcu_segcblist_is_offloaded(&rdp->cblist) &&
-	    cpu_online(rdp->cpu))
+	if (rcu_segcblist_is_offloaded(&rdp->cblist))
 		lockdep_assert_held(&rdp->nocb_lock);
 }
 
@@ -1653,7 +1647,11 @@
 		rcu_nocb_unlock_irqrestore(rdp, flags);
 		return;
 	}
-	del_timer(&rdp->nocb_timer);
+
+	if (READ_ONCE(rdp->nocb_defer_wakeup) > RCU_NOCB_WAKE_NOT) {
+		WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
+		del_timer(&rdp->nocb_timer);
+	}
 	rcu_nocb_unlock_irqrestore(rdp, flags);
 	raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags);
 	if (force || READ_ONCE(rdp_gp->nocb_gp_sleep)) {
@@ -1955,12 +1953,14 @@
 	struct rcu_data *rdp;
 	struct rcu_node *rnp;
 	unsigned long wait_gp_seq = 0; // Suppress "use uninitialized" warning.
+	bool wasempty = false;
 
 	/*
 	 * Each pass through the following loop checks for CBs and for the
 	 * nearest grace period (if any) to wait for next.  The CB kthreads
 	 * and the global grace-period kthread are awakened if needed.
 	 */
+	WARN_ON_ONCE(my_rdp->nocb_gp_rdp != my_rdp);
 	for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_cb_rdp) {
 		trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("Check"));
 		rcu_nocb_lock_irqsave(rdp, flags);
@@ -1994,10 +1994,13 @@
 		     rcu_seq_done(&rnp->gp_seq, cur_gp_seq))) {
 			raw_spin_lock_rcu_node(rnp); /* irqs disabled. */
 			needwake_gp = rcu_advance_cbs(rnp, rdp);
+			wasempty = rcu_segcblist_restempty(&rdp->cblist,
+							   RCU_NEXT_READY_TAIL);
 			raw_spin_unlock_rcu_node(rnp); /* irqs disabled. */
 		}
 		// Need to wait on some grace period?
-		WARN_ON_ONCE(!rcu_segcblist_restempty(&rdp->cblist,
+		WARN_ON_ONCE(wasempty &&
+			     !rcu_segcblist_restempty(&rdp->cblist,
 						      RCU_NEXT_READY_TAIL));
 		if (rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq)) {
 			if (!needwait_gp ||
@@ -2037,7 +2040,7 @@
 		/* Polling, so trace if first poll in the series. */
 		if (gotcbs)
 			trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Poll"));
-		schedule_timeout_interruptible(1);
+		schedule_timeout_idle(1);
 	} else if (!needwait_gp) {
 		/* Wait for callbacks to appear. */
 		trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Sleep"));
@@ -2166,7 +2169,6 @@
 		return;
 	}
 	ndw = READ_ONCE(rdp->nocb_defer_wakeup);
-	WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
 	wake_nocb_gp(rdp, ndw == RCU_NOCB_WAKE_FORCE, flags);
 	trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DeferredWake"));
 }
@@ -2448,13 +2450,12 @@
 		return;
 
 	waslocked = raw_spin_is_locked(&rdp->nocb_gp_lock);
-	wastimer = timer_pending(&rdp->nocb_timer);
+	wastimer = timer_pending(&rdp->nocb_bypass_timer);
 	wassleep = swait_active(&rdp->nocb_gp_wq);
-	if (!rdp->nocb_defer_wakeup && !rdp->nocb_gp_sleep &&
-	    !waslocked && !wastimer && !wassleep)
+	if (!rdp->nocb_gp_sleep && !waslocked && !wastimer && !wassleep)
 		return;  /* Nothing untowards. */
 
-	pr_info("   !!! %c%c%c%c %c\n",
+	pr_info("   nocb GP activity on CB-only CPU!!! %c%c%c%c %c\n",
 		"lL"[waslocked],
 		"dD"[!!rdp->nocb_defer_wakeup],
 		"tT"[wastimer],
@@ -2559,7 +2560,7 @@
 #ifdef CONFIG_NO_HZ_FULL
 	if (tick_nohz_full_cpu(smp_processor_id()) &&
 	    (!rcu_gp_in_progress() ||
-	     ULONG_CMP_LT(jiffies, READ_ONCE(rcu_state.gp_start) + HZ)))
+	     time_before(jiffies, READ_ONCE(rcu_state.gp_start) + HZ)))
 		return true;
 #endif /* #ifdef CONFIG_NO_HZ_FULL */
 	return false;
@@ -2576,7 +2577,7 @@
 }
 
 /* Record the current task on dyntick-idle entry. */
-static void rcu_dynticks_task_enter(void)
+static __always_inline void rcu_dynticks_task_enter(void)
 {
 #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL)
 	WRITE_ONCE(current->rcu_tasks_idle_cpu, smp_processor_id());
@@ -2584,9 +2585,27 @@
 }
 
 /* Record no current task on dyntick-idle exit. */
-static void rcu_dynticks_task_exit(void)
+static __always_inline void rcu_dynticks_task_exit(void)
 {
 #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL)
 	WRITE_ONCE(current->rcu_tasks_idle_cpu, -1);
 #endif /* #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL) */
 }
+
+/* Turn on heavyweight RCU tasks trace readers on idle/user entry. */
+static __always_inline void rcu_dynticks_task_trace_enter(void)
+{
+#ifdef CONFIG_TASKS_TRACE_RCU
+	if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB))
+		current->trc_reader_special.b.need_mb = true;
+#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
+}
+
+/* Turn off heavyweight RCU tasks trace readers on idle/user exit. */
+static __always_inline void rcu_dynticks_task_trace_exit(void)
+{
+#ifdef CONFIG_TASKS_TRACE_RCU
+	if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB))
+		current->trc_reader_special.b.need_mb = false;
+#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
+}
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index b8c9744..251a9af 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -17,10 +17,12 @@
 int sysctl_panic_on_rcu_stall __read_mostly;
 
 #ifdef CONFIG_PROVE_RCU
-#define RCU_STALL_DELAY_DELTA	       (5 * HZ)
+#define RCU_STALL_DELAY_DELTA		(5 * HZ)
 #else
-#define RCU_STALL_DELAY_DELTA	       0
+#define RCU_STALL_DELAY_DELTA		0
 #endif
+#define RCU_STALL_MIGHT_DIV		8
+#define RCU_STALL_MIGHT_MIN		(2 * HZ)
 
 /* Limit-check stall timeouts specified at boottime and runtime. */
 int rcu_jiffies_till_stall_check(void)
@@ -42,6 +44,36 @@
 }
 EXPORT_SYMBOL_GPL(rcu_jiffies_till_stall_check);
 
+/**
+ * rcu_gp_might_be_stalled - Is it likely that the grace period is stalled?
+ *
+ * Returns @true if the current grace period is sufficiently old that
+ * it is reasonable to assume that it might be stalled.  This can be
+ * useful when deciding whether to allocate memory to enable RCU-mediated
+ * freeing on the one hand or just invoking synchronize_rcu() on the other.
+ * The latter is preferable when the grace period is stalled.
+ *
+ * Note that sampling of the .gp_start and .gp_seq fields must be done
+ * carefully to avoid false positives at the beginnings and ends of
+ * grace periods.
+ */
+bool rcu_gp_might_be_stalled(void)
+{
+	unsigned long d = rcu_jiffies_till_stall_check() / RCU_STALL_MIGHT_DIV;
+	unsigned long j = jiffies;
+
+	if (d < RCU_STALL_MIGHT_MIN)
+		d = RCU_STALL_MIGHT_MIN;
+	smp_mb(); // jiffies before .gp_seq to avoid false positives.
+	if (!rcu_gp_in_progress())
+		return false;
+	// Long delays at this point avoids false positive, but a delay
+	// of ULONG_MAX/4 jiffies voids your no-false-positive warranty.
+	smp_mb(); // .gp_seq before second .gp_start
+	// And ditto here.
+	return !time_before(j, READ_ONCE(rcu_state.gp_start) + d);
+}
+
 /* Don't do RCU CPU stall warnings during long sysrq printouts. */
 void rcu_sysrq_start(void)
 {
@@ -104,10 +136,10 @@
 	unsigned long j = jiffies;
 	unsigned long j1;
 
-	rcu_state.gp_start = j;
+	WRITE_ONCE(rcu_state.gp_start, j);
 	j1 = rcu_jiffies_till_stall_check();
-	/* Record ->gp_start before ->jiffies_stall. */
-	smp_store_release(&rcu_state.jiffies_stall, j + j1); /* ^^^ */
+	smp_mb(); // ->gp_start before ->jiffies_stall and caller's ->gp_seq.
+	WRITE_ONCE(rcu_state.jiffies_stall, j + j1);
 	rcu_state.jiffies_resched = j + j1 / 2;
 	rcu_state.n_force_qs_gpstart = READ_ONCE(rcu_state.n_force_qs);
 }
@@ -128,7 +160,7 @@
 {
 	unsigned long j;
 
-	if (!rcu_kick_kthreads)
+	if (!READ_ONCE(rcu_kick_kthreads))
 		return;
 	j = READ_ONCE(rcu_state.jiffies_kick_kthreads);
 	if (time_after(jiffies, j) && rcu_state.gp_kthread &&
@@ -165,7 +197,7 @@
 //
 // Printing RCU CPU stall warnings
 
-#ifdef CONFIG_PREEMPTION
+#ifdef CONFIG_PREEMPT_RCU
 
 /*
  * Dump detailed information for all tasks blocking the current RCU
@@ -194,30 +226,78 @@
 	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 }
 
+// Communicate task state back to the RCU CPU stall warning request.
+struct rcu_stall_chk_rdr {
+	int nesting;
+	union rcu_special rs;
+	bool on_blkd_list;
+};
+
+/*
+ * Report out the state of a not-running task that is stalling the
+ * current RCU grace period.
+ */
+static bool check_slow_task(struct task_struct *t, void *arg)
+{
+	struct rcu_stall_chk_rdr *rscrp = arg;
+
+	if (task_curr(t))
+		return false; // It is running, so decline to inspect it.
+	rscrp->nesting = t->rcu_read_lock_nesting;
+	rscrp->rs = t->rcu_read_unlock_special;
+	rscrp->on_blkd_list = !list_empty(&t->rcu_node_entry);
+	return true;
+}
+
 /*
  * Scan the current list of tasks blocked within RCU read-side critical
- * sections, printing out the tid of each.
+ * sections, printing out the tid of each of the first few of them.
  */
-static int rcu_print_task_stall(struct rcu_node *rnp)
+static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags)
+	__releases(rnp->lock)
 {
-	struct task_struct *t;
+	int i = 0;
 	int ndetected = 0;
+	struct rcu_stall_chk_rdr rscr;
+	struct task_struct *t;
+	struct task_struct *ts[8];
 
-	if (!rcu_preempt_blocked_readers_cgp(rnp))
+	lockdep_assert_irqs_disabled();
+	if (!rcu_preempt_blocked_readers_cgp(rnp)) {
+		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 		return 0;
+	}
 	pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):",
 	       rnp->level, rnp->grplo, rnp->grphi);
 	t = list_entry(rnp->gp_tasks->prev,
 		       struct task_struct, rcu_node_entry);
 	list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) {
-		pr_cont(" P%d", t->pid);
+		get_task_struct(t);
+		ts[i++] = t;
+		if (i >= ARRAY_SIZE(ts))
+			break;
+	}
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+	while (i) {
+		t = ts[--i];
+		if (!try_invoke_on_locked_down_task(t, check_slow_task, &rscr))
+			pr_cont(" P%d", t->pid);
+		else
+			pr_cont(" P%d/%d:%c%c%c%c",
+				t->pid, rscr.nesting,
+				".b"[rscr.rs.b.blocked],
+				".q"[rscr.rs.b.need_qs],
+				".e"[rscr.rs.b.exp_hint],
+				".l"[rscr.on_blkd_list]);
+		lockdep_assert_irqs_disabled();
+		put_task_struct(t);
 		ndetected++;
 	}
 	pr_cont("\n");
 	return ndetected;
 }
 
-#else /* #ifdef CONFIG_PREEMPTION */
+#else /* #ifdef CONFIG_PREEMPT_RCU */
 
 /*
  * Because preemptible RCU does not exist, we never have to check for
@@ -231,11 +311,12 @@
  * Because preemptible RCU does not exist, we never have to check for
  * tasks blocked within RCU read-side critical sections.
  */
-static int rcu_print_task_stall(struct rcu_node *rnp)
+static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags)
 {
+	raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 	return 0;
 }
-#endif /* #else #ifdef CONFIG_PREEMPTION */
+#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
 
 /*
  * Dump stacks of all tasks running on stalled CPUs.  First try using
@@ -265,11 +346,9 @@
 {
 	struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
 
-	sprintf(cp, "last_accelerate: %04lx/%04lx, Nonlazy posted: %c%c%c",
+	sprintf(cp, "last_accelerate: %04lx/%04lx dyntick_enabled: %d",
 		rdp->last_accelerate & 0xffff, jiffies & 0xffff,
-		".l"[rdp->all_lazy],
-		".L"[!rcu_segcblist_n_nonlazy_cbs(&rdp->cblist)],
-		".D"[!!rdp->tick_nohz_enabled_snap]);
+		!!rdp->tick_nohz_enabled_snap);
 }
 
 #else /* #ifdef CONFIG_RCU_FAST_NO_HZ */
@@ -281,6 +360,38 @@
 
 #endif /* #else #ifdef CONFIG_RCU_FAST_NO_HZ */
 
+static const char * const gp_state_names[] = {
+	[RCU_GP_IDLE] = "RCU_GP_IDLE",
+	[RCU_GP_WAIT_GPS] = "RCU_GP_WAIT_GPS",
+	[RCU_GP_DONE_GPS] = "RCU_GP_DONE_GPS",
+	[RCU_GP_ONOFF] = "RCU_GP_ONOFF",
+	[RCU_GP_INIT] = "RCU_GP_INIT",
+	[RCU_GP_WAIT_FQS] = "RCU_GP_WAIT_FQS",
+	[RCU_GP_DOING_FQS] = "RCU_GP_DOING_FQS",
+	[RCU_GP_CLEANUP] = "RCU_GP_CLEANUP",
+	[RCU_GP_CLEANED] = "RCU_GP_CLEANED",
+};
+
+/*
+ * Convert a ->gp_state value to a character string.
+ */
+static const char *gp_state_getname(short gs)
+{
+	if (gs < 0 || gs >= ARRAY_SIZE(gp_state_names))
+		return "???";
+	return gp_state_names[gs];
+}
+
+/* Is the RCU grace-period kthread being starved of CPU time? */
+static bool rcu_is_gp_kthread_starving(unsigned long *jp)
+{
+	unsigned long j = jiffies - READ_ONCE(rcu_state.gp_activity);
+
+	if (jp)
+		*jp = j;
+	return j > 2 * HZ;
+}
+
 /*
  * Print out diagnostic information for the specified stalled CPU.
  *
@@ -295,6 +406,7 @@
 static void print_cpu_stall_info(int cpu)
 {
 	unsigned long delta;
+	bool falsepositive;
 	char fast_no_hz[72];
 	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
 	char *ticks_title;
@@ -315,7 +427,9 @@
 	}
 	print_cpu_stall_fast_no_hz(fast_no_hz, cpu);
 	delta = rcu_seq_ctr(rdp->mynode->gp_seq - rdp->rcu_iw_gp_seq);
-	pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%#lx softirq=%u/%u fqs=%ld %s\n",
+	falsepositive = rcu_is_gp_kthread_starving(NULL) &&
+			rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp));
+	pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%#lx softirq=%u/%u fqs=%ld %s%s\n",
 	       cpu,
 	       "O."[!!cpu_online(cpu)],
 	       "o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)],
@@ -327,8 +441,9 @@
 	       rcu_dynticks_snap(rdp) & 0xfff,
 	       rdp->dynticks_nesting, rdp->dynticks_nmi_nesting,
 	       rdp->softirq_snap, kstat_softirqs_cpu(RCU_SOFTIRQ, cpu),
-	       READ_ONCE(rcu_state.n_force_qs) - rcu_state.n_force_qs_gpstart,
-	       fast_no_hz);
+	       data_race(rcu_state.n_force_qs) - rcu_state.n_force_qs_gpstart,
+	       fast_no_hz,
+	       falsepositive ? " (false positive?)" : "");
 }
 
 /* Complain about starvation of grace-period kthread.  */
@@ -337,15 +452,15 @@
 	struct task_struct *gpk = rcu_state.gp_kthread;
 	unsigned long j;
 
-	j = jiffies - READ_ONCE(rcu_state.gp_activity);
-	if (j > 2 * HZ) {
+	if (rcu_is_gp_kthread_starving(&j)) {
 		pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#lx ->cpu=%d\n",
 		       rcu_state.name, j,
 		       (long)rcu_seq_current(&rcu_state.gp_seq),
-		       READ_ONCE(rcu_state.gp_flags),
+		       data_race(rcu_state.gp_flags),
 		       gp_state_getname(rcu_state.gp_state), rcu_state.gp_state,
 		       gpk ? gpk->state : ~0, gpk ? task_cpu(gpk) : -1);
 		if (gpk) {
+			pr_err("\tUnless %s kthread gets sufficient CPU time, OOM is now expected behavior.\n", rcu_state.name);
 			pr_err("RCU grace-period kthread stack dump:\n");
 			sched_show_task(gpk);
 			wake_up_process(gpk);
@@ -353,7 +468,7 @@
 	}
 }
 
-static void print_other_cpu_stall(unsigned long gp_seq)
+static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps)
 {
 	int cpu;
 	unsigned long flags;
@@ -363,20 +478,21 @@
 	struct rcu_node *rnp;
 	long totqlen = 0;
 
+	lockdep_assert_irqs_disabled();
+
 	/* Kick and suppress, if so configured. */
 	rcu_stall_kick_kthreads();
-	if (rcu_cpu_stall_suppress)
+	if (rcu_stall_is_suppressed())
 		return;
 
 	/*
 	 * OK, time to rat on our buddy...
-	 * See Documentation/RCU/stallwarn.txt for info on how to debug
+	 * See Documentation/RCU/stallwarn.rst for info on how to debug
 	 * RCU CPU stall warnings.
 	 */
 	pr_err("INFO: %s detected stalls on CPUs/tasks:\n", rcu_state.name);
 	rcu_for_each_leaf_node(rnp) {
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
-		ndetected += rcu_print_task_stall(rnp);
 		if (rnp->qsmask != 0) {
 			for_each_leaf_node_possible_cpu(rnp, cpu)
 				if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu)) {
@@ -384,13 +500,14 @@
 					ndetected++;
 				}
 		}
-		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+		ndetected += rcu_print_task_stall(rnp, flags); // Releases rnp->lock.
+		lockdep_assert_irqs_disabled();
 	}
 
 	for_each_possible_cpu(cpu)
 		totqlen += rcu_get_n_cbs_cpu(cpu);
 	pr_cont("\t(detected by %d, t=%ld jiffies, g=%ld, q=%lu)\n",
-	       smp_processor_id(), (long)(jiffies - rcu_state.gp_start),
+	       smp_processor_id(), (long)(jiffies - gps),
 	       (long)rcu_seq_current(&rcu_state.gp_seq), totqlen);
 	if (ndetected) {
 		rcu_dump_cpu_stacks();
@@ -403,13 +520,11 @@
 			pr_err("INFO: Stall ended before state dump start\n");
 		} else {
 			j = jiffies;
-			gpa = READ_ONCE(rcu_state.gp_activity);
+			gpa = data_race(rcu_state.gp_activity);
 			pr_err("All QSes seen, last %s kthread activity %ld (%ld-%ld), jiffies_till_next_fqs=%ld, root ->qsmask %#lx\n",
 			       rcu_state.name, j - gpa, j, gpa,
-			       READ_ONCE(jiffies_till_next_fqs),
+			       data_race(jiffies_till_next_fqs),
 			       rcu_get_root()->qsmask);
-			/* In this case, the current CPU might be at fault. */
-			sched_show_task(current);
 		}
 	}
 	/* Rewrite if needed in case of slow consoles. */
@@ -424,7 +539,7 @@
 	rcu_force_quiescent_state();  /* Kick them all. */
 }
 
-static void print_cpu_stall(void)
+static void print_cpu_stall(unsigned long gps)
 {
 	int cpu;
 	unsigned long flags;
@@ -432,14 +547,16 @@
 	struct rcu_node *rnp = rcu_get_root();
 	long totqlen = 0;
 
+	lockdep_assert_irqs_disabled();
+
 	/* Kick and suppress, if so configured. */
 	rcu_stall_kick_kthreads();
-	if (rcu_cpu_stall_suppress)
+	if (rcu_stall_is_suppressed())
 		return;
 
 	/*
 	 * OK, time to rat on ourselves...
-	 * See Documentation/RCU/stallwarn.txt for info on how to debug
+	 * See Documentation/RCU/stallwarn.rst for info on how to debug
 	 * RCU CPU stall warnings.
 	 */
 	pr_err("INFO: %s self-detected stall on CPU\n", rcu_state.name);
@@ -449,7 +566,7 @@
 	for_each_possible_cpu(cpu)
 		totqlen += rcu_get_n_cbs_cpu(cpu);
 	pr_cont("\t(t=%lu jiffies g=%ld q=%lu)\n",
-		jiffies - rcu_state.gp_start,
+		jiffies - gps,
 		(long)rcu_seq_current(&rcu_state.gp_seq), totqlen);
 
 	rcu_check_gp_kthread_starvation();
@@ -486,7 +603,8 @@
 	unsigned long js;
 	struct rcu_node *rnp;
 
-	if ((rcu_cpu_stall_suppress && !rcu_kick_kthreads) ||
+	lockdep_assert_irqs_disabled();
+	if ((rcu_stall_is_suppressed() && !READ_ONCE(rcu_kick_kthreads)) ||
 	    !rcu_gp_in_progress())
 		return;
 	rcu_stall_kick_kthreads();
@@ -536,8 +654,8 @@
 			return;
 
 		/* We haven't checked in, so go dump stack. */
-		print_cpu_stall();
-		if (rcu_cpu_stall_ftrace_dump)
+		print_cpu_stall(gps);
+		if (READ_ONCE(rcu_cpu_stall_ftrace_dump))
 			rcu_ftrace_dump(DUMP_ALL);
 
 	} else if (rcu_gp_in_progress() &&
@@ -553,8 +671,8 @@
 			return;
 
 		/* They had a few time units to dump stack, so complain. */
-		print_other_cpu_stall(gs2);
-		if (rcu_cpu_stall_ftrace_dump)
+		print_other_cpu_stall(gs2, gps);
+		if (READ_ONCE(rcu_cpu_stall_ftrace_dump))
 			rcu_ftrace_dump(DUMP_ALL);
 	}
 }
@@ -569,6 +687,7 @@
  */
 void show_rcu_gp_kthreads(void)
 {
+	unsigned long cbs = 0;
 	int cpu;
 	unsigned long j;
 	unsigned long ja;
@@ -576,43 +695,46 @@
 	unsigned long jw;
 	struct rcu_data *rdp;
 	struct rcu_node *rnp;
+	struct task_struct *t = READ_ONCE(rcu_state.gp_kthread);
 
 	j = jiffies;
-	ja = j - READ_ONCE(rcu_state.gp_activity);
-	jr = j - READ_ONCE(rcu_state.gp_req_activity);
-	jw = j - READ_ONCE(rcu_state.gp_wake_time);
+	ja = j - data_race(rcu_state.gp_activity);
+	jr = j - data_race(rcu_state.gp_req_activity);
+	jw = j - data_race(rcu_state.gp_wake_time);
 	pr_info("%s: wait state: %s(%d) ->state: %#lx delta ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_flags %#x\n",
 		rcu_state.name, gp_state_getname(rcu_state.gp_state),
-		rcu_state.gp_state,
-		rcu_state.gp_kthread ? rcu_state.gp_kthread->state : 0x1ffffL,
-		ja, jr, jw, (long)READ_ONCE(rcu_state.gp_wake_seq),
-		(long)READ_ONCE(rcu_state.gp_seq),
-		(long)READ_ONCE(rcu_get_root()->gp_seq_needed),
-		READ_ONCE(rcu_state.gp_flags));
+		rcu_state.gp_state, t ? t->state : 0x1ffffL,
+		ja, jr, jw, (long)data_race(rcu_state.gp_wake_seq),
+		(long)data_race(rcu_state.gp_seq),
+		(long)data_race(rcu_get_root()->gp_seq_needed),
+		data_race(rcu_state.gp_flags));
 	rcu_for_each_node_breadth_first(rnp) {
-		if (ULONG_CMP_GE(rcu_state.gp_seq, rnp->gp_seq_needed))
+		if (ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq),
+				 READ_ONCE(rnp->gp_seq_needed)))
 			continue;
 		pr_info("\trcu_node %d:%d ->gp_seq %ld ->gp_seq_needed %ld\n",
-			rnp->grplo, rnp->grphi, (long)rnp->gp_seq,
-			(long)rnp->gp_seq_needed);
+			rnp->grplo, rnp->grphi, (long)data_race(rnp->gp_seq),
+			(long)data_race(rnp->gp_seq_needed));
 		if (!rcu_is_leaf_node(rnp))
 			continue;
 		for_each_leaf_node_possible_cpu(rnp, cpu) {
 			rdp = per_cpu_ptr(&rcu_data, cpu);
-			if (rdp->gpwrap ||
-			    ULONG_CMP_GE(rcu_state.gp_seq,
-					 rdp->gp_seq_needed))
+			if (READ_ONCE(rdp->gpwrap) ||
+			    ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq),
+					 READ_ONCE(rdp->gp_seq_needed)))
 				continue;
 			pr_info("\tcpu %d ->gp_seq_needed %ld\n",
-				cpu, (long)rdp->gp_seq_needed);
+				cpu, (long)data_race(rdp->gp_seq_needed));
 		}
 	}
 	for_each_possible_cpu(cpu) {
 		rdp = per_cpu_ptr(&rcu_data, cpu);
+		cbs += data_race(rdp->n_cbs_invoked);
 		if (rcu_segcblist_is_offloaded(&rdp->cblist))
 			show_rcu_nocb_state(rdp);
 	}
-	/* sched_show_task(rcu_state.gp_kthread); */
+	pr_info("RCU callbacks invoked since boot: %lu\n", cbs);
+	show_rcu_tasks_gp_kthreads();
 }
 EXPORT_SYMBOL_GPL(show_rcu_gp_kthreads);
 
@@ -629,7 +751,9 @@
 	static atomic_t warned = ATOMIC_INIT(0);
 
 	if (!IS_ENABLED(CONFIG_PROVE_RCU) || rcu_gp_in_progress() ||
-	    ULONG_CMP_GE(rnp_root->gp_seq, rnp_root->gp_seq_needed))
+	    ULONG_CMP_GE(READ_ONCE(rnp_root->gp_seq),
+			 READ_ONCE(rnp_root->gp_seq_needed)) ||
+	    !smp_load_acquire(&rcu_state.gp_kthread)) // Get stable kthread.
 		return;
 	j = jiffies; /* Expensive access, and in common case don't get here. */
 	if (time_before(j, READ_ONCE(rcu_state.gp_req_activity) + gpssdelay) ||
@@ -640,7 +764,8 @@
 	raw_spin_lock_irqsave_rcu_node(rnp, flags);
 	j = jiffies;
 	if (rcu_gp_in_progress() ||
-	    ULONG_CMP_GE(rnp_root->gp_seq, rnp_root->gp_seq_needed) ||
+	    ULONG_CMP_GE(READ_ONCE(rnp_root->gp_seq),
+			 READ_ONCE(rnp_root->gp_seq_needed)) ||
 	    time_before(j, READ_ONCE(rcu_state.gp_req_activity) + gpssdelay) ||
 	    time_before(j, READ_ONCE(rcu_state.gp_activity) + gpssdelay) ||
 	    atomic_read(&warned)) {
@@ -653,9 +778,10 @@
 		raw_spin_lock_rcu_node(rnp_root); /* irqs already disabled. */
 	j = jiffies;
 	if (rcu_gp_in_progress() ||
-	    ULONG_CMP_GE(rnp_root->gp_seq, rnp_root->gp_seq_needed) ||
-	    time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
-	    time_before(j, rcu_state.gp_activity + gpssdelay) ||
+	    ULONG_CMP_GE(READ_ONCE(rnp_root->gp_seq),
+			 READ_ONCE(rnp_root->gp_seq_needed)) ||
+	    time_before(j, READ_ONCE(rcu_state.gp_req_activity) + gpssdelay) ||
+	    time_before(j, READ_ONCE(rcu_state.gp_activity) + gpssdelay) ||
 	    atomic_xchg(&warned, 1)) {
 		if (rnp_root != rnp)
 			/* irqs remain disabled. */
@@ -722,7 +848,7 @@
 	show_rcu_gp_kthreads();
 }
 
-static struct sysrq_key_op sysrq_rcudump_op = {
+static const struct sysrq_key_op sysrq_rcudump_op = {
 	.handler = sysrq_show_rcu,
 	.help_msg = "show-rcu(y)",
 	.action_msg = "Show RCU tree",
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 1861103..849f0aa 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -40,6 +40,9 @@
 #include <linux/rcupdate_wait.h>
 #include <linux/sched/isolation.h>
 #include <linux/kprobes.h>
+#include <linux/slab.h>
+#include <linux/irq_work.h>
+#include <linux/rcupdate_trace.h>
 
 #define CREATE_TRACE_POINTS
 
@@ -51,9 +54,7 @@
 #define MODULE_PARAM_PREFIX "rcupdate."
 
 #ifndef CONFIG_TINY_RCU
-extern int rcu_expedited; /* from sysctl */
 module_param(rcu_expedited, int, 0);
-extern int rcu_normal; /* from sysctl */
 module_param(rcu_normal, int, 0);
 static int rcu_normal_after_boot;
 module_param(rcu_normal_after_boot, int, 0);
@@ -64,12 +65,12 @@
  * rcu_read_lock_held_common() - might we be in RCU-sched read-side critical section?
  * @ret:	Best guess answer if lockdep cannot be relied on
  *
- * Returns true if lockdep must be ignored, in which case *ret contains
+ * Returns true if lockdep must be ignored, in which case ``*ret`` contains
  * the best guess described below.  Otherwise returns false, in which
- * case *ret tells the caller nothing and the caller should instead
+ * case ``*ret`` tells the caller nothing and the caller should instead
  * consult lockdep.
  *
- * If CONFIG_DEBUG_LOCK_ALLOC is selected, set *ret to nonzero iff in an
+ * If CONFIG_DEBUG_LOCK_ALLOC is selected, set ``*ret`` to nonzero iff in an
  * RCU-sched read-side critical section.  In absence of
  * CONFIG_DEBUG_LOCK_ALLOC, this assumes we are in an RCU-sched read-side
  * critical section unless it can prove otherwise.  Note that disabling
@@ -83,7 +84,7 @@
  *
  * Note that if the CPU is in the idle loop from an RCU point of view (ie:
  * that we are in the section between rcu_idle_enter() and rcu_idle_exit())
- * then rcu_read_lock_held() sets *ret to false even if the CPU did an
+ * then rcu_read_lock_held() sets ``*ret`` to false even if the CPU did an
  * rcu_read_lock().  The reason for this is that RCU ignores CPUs that are
  * in such a section, considering these as in extended quiescent state,
  * so such a CPU is effectively never in an RCU read-side critical section
@@ -99,15 +100,15 @@
 static bool rcu_read_lock_held_common(bool *ret)
 {
 	if (!debug_lockdep_rcu_enabled()) {
-		*ret = 1;
+		*ret = true;
 		return true;
 	}
 	if (!rcu_is_watching()) {
-		*ret = 0;
+		*ret = false;
 		return true;
 	}
 	if (!rcu_lockdep_current_cpu_online()) {
-		*ret = 0;
+		*ret = false;
 		return true;
 	}
 	return false;
@@ -184,6 +185,8 @@
 }
 EXPORT_SYMBOL_GPL(rcu_unexpedite_gp);
 
+static bool rcu_boot_ended __read_mostly;
+
 /*
  * Inform RCU of the end of the in-kernel boot sequence.
  */
@@ -192,8 +195,18 @@
 	rcu_unexpedite_gp();
 	if (rcu_normal_after_boot)
 		WRITE_ONCE(rcu_normal, 1);
+	rcu_boot_ended = true;
 }
 
+/*
+ * Let rcutorture know when it is OK to turn it up to eleven.
+ */
+bool rcu_inkernel_boot_has_ended(void)
+{
+	return rcu_boot_ended;
+}
+EXPORT_SYMBOL_GPL(rcu_inkernel_boot_has_ended);
+
 #endif /* #ifndef CONFIG_TINY_RCU */
 
 /*
@@ -218,6 +231,7 @@
 {
 	rcu_test_sync_prims();
 	rcu_scheduler_active = RCU_SCHEDULER_RUNNING;
+	kfree_rcu_scheduler_running();
 	rcu_test_sync_prims();
 	return 0;
 }
@@ -227,32 +241,44 @@
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 static struct lock_class_key rcu_lock_key;
-struct lockdep_map rcu_lock_map =
-	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
+struct lockdep_map rcu_lock_map = {
+	.name = "rcu_read_lock",
+	.key = &rcu_lock_key,
+	.wait_type_outer = LD_WAIT_FREE,
+	.wait_type_inner = LD_WAIT_CONFIG, /* XXX PREEMPT_RCU ? */
+};
 EXPORT_SYMBOL_GPL(rcu_lock_map);
 
 static struct lock_class_key rcu_bh_lock_key;
-struct lockdep_map rcu_bh_lock_map =
-	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_bh", &rcu_bh_lock_key);
+struct lockdep_map rcu_bh_lock_map = {
+	.name = "rcu_read_lock_bh",
+	.key = &rcu_bh_lock_key,
+	.wait_type_outer = LD_WAIT_FREE,
+	.wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_LOCK also makes BH preemptible */
+};
 EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
 
 static struct lock_class_key rcu_sched_lock_key;
-struct lockdep_map rcu_sched_lock_map =
-	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_sched", &rcu_sched_lock_key);
+struct lockdep_map rcu_sched_lock_map = {
+	.name = "rcu_read_lock_sched",
+	.key = &rcu_sched_lock_key,
+	.wait_type_outer = LD_WAIT_FREE,
+	.wait_type_inner = LD_WAIT_SPIN,
+};
 EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
 
+// Tell lockdep when RCU callbacks are being invoked.
 static struct lock_class_key rcu_callback_key;
 struct lockdep_map rcu_callback_map =
 	STATIC_LOCKDEP_MAP_INIT("rcu_callback", &rcu_callback_key);
 EXPORT_SYMBOL_GPL(rcu_callback_map);
 
-int notrace debug_lockdep_rcu_enabled(void)
+noinstr int notrace debug_lockdep_rcu_enabled(void)
 {
-	return rcu_scheduler_active != RCU_SCHEDULER_INACTIVE && debug_locks &&
+	return rcu_scheduler_active != RCU_SCHEDULER_INACTIVE && READ_ONCE(debug_locks) &&
 	       current->lockdep_recursion == 0;
 }
 EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
-NOKPROBE_SYMBOL(debug_lockdep_rcu_enabled);
 
 /**
  * rcu_read_lock_held() - might we be in RCU read-side critical section?
@@ -353,13 +379,14 @@
 			might_sleep();
 			continue;
 		}
-		init_rcu_head_on_stack(&rs_array[i].head);
-		init_completion(&rs_array[i].completion);
 		for (j = 0; j < i; j++)
 			if (crcu_array[j] == crcu_array[i])
 				break;
-		if (j == i)
+		if (j == i) {
+			init_rcu_head_on_stack(&rs_array[i].head);
+			init_completion(&rs_array[i].completion);
 			(crcu_array[i])(&rs_array[i].head, wakeme_after_rcu);
+		}
 	}
 
 	/* Wait for all callbacks to be invoked. */
@@ -370,9 +397,10 @@
 		for (j = 0; j < i; j++)
 			if (crcu_array[j] == crcu_array[i])
 				break;
-		if (j == i)
+		if (j == i) {
 			wait_for_completion(&rs_array[i].completion);
-		destroy_rcu_head_on_stack(&rs_array[i].head);
+			destroy_rcu_head_on_stack(&rs_array[i].head);
+		}
 	}
 }
 EXPORT_SYMBOL_GPL(__wait_rcu_gp);
@@ -428,14 +456,14 @@
 }
 EXPORT_SYMBOL_GPL(destroy_rcu_head_on_stack);
 
-struct debug_obj_descr rcuhead_debug_descr = {
+const struct debug_obj_descr rcuhead_debug_descr = {
 	.name = "rcu_head",
 	.is_static_object = rcuhead_is_static_object,
 };
 EXPORT_SYMBOL_GPL(rcuhead_debug_descr);
 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
 
-#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU) || defined(CONFIG_RCU_TRACE)
+#if defined(CONFIG_TREE_RCU) || defined(CONFIG_RCU_TRACE)
 void do_trace_rcu_torture_read(const char *rcutorturename, struct rcu_head *rhp,
 			       unsigned long secs,
 			       unsigned long c_old, unsigned long c)
@@ -464,376 +492,18 @@
 #ifdef CONFIG_RCU_STALL_COMMON
 int rcu_cpu_stall_ftrace_dump __read_mostly;
 module_param(rcu_cpu_stall_ftrace_dump, int, 0644);
-int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */
+int rcu_cpu_stall_suppress __read_mostly; // !0 = suppress stall warnings.
 EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress);
 module_param(rcu_cpu_stall_suppress, int, 0644);
 int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT;
 module_param(rcu_cpu_stall_timeout, int, 0644);
 #endif /* #ifdef CONFIG_RCU_STALL_COMMON */
 
-#ifdef CONFIG_TASKS_RCU
-
-/*
- * Simple variant of RCU whose quiescent states are voluntary context
- * switch, cond_resched_rcu_qs(), user-space execution, and idle.
- * As such, grace periods can take one good long time.  There are no
- * read-side primitives similar to rcu_read_lock() and rcu_read_unlock()
- * because this implementation is intended to get the system into a safe
- * state for some of the manipulations involved in tracing and the like.
- * Finally, this implementation does not support high call_rcu_tasks()
- * rates from multiple CPUs.  If this is required, per-CPU callback lists
- * will be needed.
- */
-
-/* Global list of callbacks and associated lock. */
-static struct rcu_head *rcu_tasks_cbs_head;
-static struct rcu_head **rcu_tasks_cbs_tail = &rcu_tasks_cbs_head;
-static DECLARE_WAIT_QUEUE_HEAD(rcu_tasks_cbs_wq);
-static DEFINE_RAW_SPINLOCK(rcu_tasks_cbs_lock);
-
-/* Track exiting tasks in order to allow them to be waited for. */
-DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu);
-
-/* Control stall timeouts.  Disable with <= 0, otherwise jiffies till stall. */
-#define RCU_TASK_STALL_TIMEOUT (HZ * 60 * 10)
-static int rcu_task_stall_timeout __read_mostly = RCU_TASK_STALL_TIMEOUT;
-module_param(rcu_task_stall_timeout, int, 0644);
-
-static struct task_struct *rcu_tasks_kthread_ptr;
-
-/**
- * call_rcu_tasks() - Queue an RCU for invocation task-based grace period
- * @rhp: structure to be used for queueing the RCU updates.
- * @func: actual callback function to be invoked after the grace period
- *
- * The callback function will be invoked some time after a full grace
- * period elapses, in other words after all currently executing RCU
- * read-side critical sections have completed. call_rcu_tasks() assumes
- * that the read-side critical sections end at a voluntary context
- * switch (not a preemption!), cond_resched_rcu_qs(), entry into idle,
- * or transition to usermode execution.  As such, there are no read-side
- * primitives analogous to rcu_read_lock() and rcu_read_unlock() because
- * this primitive is intended to determine that all tasks have passed
- * through a safe state, not so much for data-strcuture synchronization.
- *
- * See the description of call_rcu() for more detailed information on
- * memory ordering guarantees.
- */
-void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func)
-{
-	unsigned long flags;
-	bool needwake;
-
-	rhp->next = NULL;
-	rhp->func = func;
-	raw_spin_lock_irqsave(&rcu_tasks_cbs_lock, flags);
-	needwake = !rcu_tasks_cbs_head;
-	*rcu_tasks_cbs_tail = rhp;
-	rcu_tasks_cbs_tail = &rhp->next;
-	raw_spin_unlock_irqrestore(&rcu_tasks_cbs_lock, flags);
-	/* We can't create the thread unless interrupts are enabled. */
-	if (needwake && READ_ONCE(rcu_tasks_kthread_ptr))
-		wake_up(&rcu_tasks_cbs_wq);
-}
-EXPORT_SYMBOL_GPL(call_rcu_tasks);
-
-/**
- * synchronize_rcu_tasks - wait until an rcu-tasks grace period has elapsed.
- *
- * Control will return to the caller some time after a full rcu-tasks
- * grace period has elapsed, in other words after all currently
- * executing rcu-tasks read-side critical sections have elapsed.  These
- * read-side critical sections are delimited by calls to schedule(),
- * cond_resched_tasks_rcu_qs(), idle execution, userspace execution, calls
- * to synchronize_rcu_tasks(), and (in theory, anyway) cond_resched().
- *
- * This is a very specialized primitive, intended only for a few uses in
- * tracing and other situations requiring manipulation of function
- * preambles and profiling hooks.  The synchronize_rcu_tasks() function
- * is not (yet) intended for heavy use from multiple CPUs.
- *
- * Note that this guarantee implies further memory-ordering guarantees.
- * On systems with more than one CPU, when synchronize_rcu_tasks() returns,
- * each CPU is guaranteed to have executed a full memory barrier since the
- * end of its last RCU-tasks read-side critical section whose beginning
- * preceded the call to synchronize_rcu_tasks().  In addition, each CPU
- * having an RCU-tasks read-side critical section that extends beyond
- * the return from synchronize_rcu_tasks() is guaranteed to have executed
- * a full memory barrier after the beginning of synchronize_rcu_tasks()
- * and before the beginning of that RCU-tasks read-side critical section.
- * Note that these guarantees include CPUs that are offline, idle, or
- * executing in user mode, as well as CPUs that are executing in the kernel.
- *
- * Furthermore, if CPU A invoked synchronize_rcu_tasks(), which returned
- * to its caller on CPU B, then both CPU A and CPU B are guaranteed
- * to have executed a full memory barrier during the execution of
- * synchronize_rcu_tasks() -- even if CPU A and CPU B are the same CPU
- * (but again only if the system has more than one CPU).
- */
-void synchronize_rcu_tasks(void)
-{
-	/* Complain if the scheduler has not started.  */
-	RCU_LOCKDEP_WARN(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE,
-			 "synchronize_rcu_tasks called too soon");
-
-	/* Wait for the grace period. */
-	wait_rcu_gp(call_rcu_tasks);
-}
-EXPORT_SYMBOL_GPL(synchronize_rcu_tasks);
-
-/**
- * rcu_barrier_tasks - Wait for in-flight call_rcu_tasks() callbacks.
- *
- * Although the current implementation is guaranteed to wait, it is not
- * obligated to, for example, if there are no pending callbacks.
- */
-void rcu_barrier_tasks(void)
-{
-	/* There is only one callback queue, so this is easy.  ;-) */
-	synchronize_rcu_tasks();
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_tasks);
-
-/* See if tasks are still holding out, complain if so. */
-static void check_holdout_task(struct task_struct *t,
-			       bool needreport, bool *firstreport)
-{
-	int cpu;
-
-	if (!READ_ONCE(t->rcu_tasks_holdout) ||
-	    t->rcu_tasks_nvcsw != READ_ONCE(t->nvcsw) ||
-	    !READ_ONCE(t->on_rq) ||
-	    (IS_ENABLED(CONFIG_NO_HZ_FULL) &&
-	     !is_idle_task(t) && t->rcu_tasks_idle_cpu >= 0)) {
-		WRITE_ONCE(t->rcu_tasks_holdout, false);
-		list_del_init(&t->rcu_tasks_holdout_list);
-		put_task_struct(t);
-		return;
-	}
-	rcu_request_urgent_qs_task(t);
-	if (!needreport)
-		return;
-	if (*firstreport) {
-		pr_err("INFO: rcu_tasks detected stalls on tasks:\n");
-		*firstreport = false;
-	}
-	cpu = task_cpu(t);
-	pr_alert("%p: %c%c nvcsw: %lu/%lu holdout: %d idle_cpu: %d/%d\n",
-		 t, ".I"[is_idle_task(t)],
-		 "N."[cpu < 0 || !tick_nohz_full_cpu(cpu)],
-		 t->rcu_tasks_nvcsw, t->nvcsw, t->rcu_tasks_holdout,
-		 t->rcu_tasks_idle_cpu, cpu);
-	sched_show_task(t);
-}
-
-/* RCU-tasks kthread that detects grace periods and invokes callbacks. */
-static int __noreturn rcu_tasks_kthread(void *arg)
-{
-	unsigned long flags;
-	struct task_struct *g, *t;
-	unsigned long lastreport;
-	struct rcu_head *list;
-	struct rcu_head *next;
-	LIST_HEAD(rcu_tasks_holdouts);
-	int fract;
-
-	/* Run on housekeeping CPUs by default.  Sysadm can move if desired. */
-	housekeeping_affine(current, HK_FLAG_RCU);
-
-	/*
-	 * Each pass through the following loop makes one check for
-	 * newly arrived callbacks, and, if there are some, waits for
-	 * one RCU-tasks grace period and then invokes the callbacks.
-	 * This loop is terminated by the system going down.  ;-)
-	 */
-	for (;;) {
-
-		/* Pick up any new callbacks. */
-		raw_spin_lock_irqsave(&rcu_tasks_cbs_lock, flags);
-		list = rcu_tasks_cbs_head;
-		rcu_tasks_cbs_head = NULL;
-		rcu_tasks_cbs_tail = &rcu_tasks_cbs_head;
-		raw_spin_unlock_irqrestore(&rcu_tasks_cbs_lock, flags);
-
-		/* If there were none, wait a bit and start over. */
-		if (!list) {
-			wait_event_interruptible(rcu_tasks_cbs_wq,
-						 rcu_tasks_cbs_head);
-			if (!rcu_tasks_cbs_head) {
-				WARN_ON(signal_pending(current));
-				schedule_timeout_interruptible(HZ/10);
-			}
-			continue;
-		}
-
-		/*
-		 * Wait for all pre-existing t->on_rq and t->nvcsw
-		 * transitions to complete.  Invoking synchronize_rcu()
-		 * suffices because all these transitions occur with
-		 * interrupts disabled.  Without this synchronize_rcu(),
-		 * a read-side critical section that started before the
-		 * grace period might be incorrectly seen as having started
-		 * after the grace period.
-		 *
-		 * This synchronize_rcu() also dispenses with the
-		 * need for a memory barrier on the first store to
-		 * ->rcu_tasks_holdout, as it forces the store to happen
-		 * after the beginning of the grace period.
-		 */
-		synchronize_rcu();
-
-		/*
-		 * There were callbacks, so we need to wait for an
-		 * RCU-tasks grace period.  Start off by scanning
-		 * the task list for tasks that are not already
-		 * voluntarily blocked.  Mark these tasks and make
-		 * a list of them in rcu_tasks_holdouts.
-		 */
-		rcu_read_lock();
-		for_each_process_thread(g, t) {
-			if (t != current && READ_ONCE(t->on_rq) &&
-			    !is_idle_task(t)) {
-				get_task_struct(t);
-				t->rcu_tasks_nvcsw = READ_ONCE(t->nvcsw);
-				WRITE_ONCE(t->rcu_tasks_holdout, true);
-				list_add(&t->rcu_tasks_holdout_list,
-					 &rcu_tasks_holdouts);
-			}
-		}
-		rcu_read_unlock();
-
-		/*
-		 * Wait for tasks that are in the process of exiting.
-		 * This does only part of the job, ensuring that all
-		 * tasks that were previously exiting reach the point
-		 * where they have disabled preemption, allowing the
-		 * later synchronize_rcu() to finish the job.
-		 */
-		synchronize_srcu(&tasks_rcu_exit_srcu);
-
-		/*
-		 * Each pass through the following loop scans the list
-		 * of holdout tasks, removing any that are no longer
-		 * holdouts.  When the list is empty, we are done.
-		 */
-		lastreport = jiffies;
-
-		/* Start off with HZ/10 wait and slowly back off to 1 HZ wait*/
-		fract = 10;
-
-		for (;;) {
-			bool firstreport;
-			bool needreport;
-			int rtst;
-			struct task_struct *t1;
-
-			if (list_empty(&rcu_tasks_holdouts))
-				break;
-
-			/* Slowly back off waiting for holdouts */
-			schedule_timeout_interruptible(HZ/fract);
-
-			if (fract > 1)
-				fract--;
-
-			rtst = READ_ONCE(rcu_task_stall_timeout);
-			needreport = rtst > 0 &&
-				     time_after(jiffies, lastreport + rtst);
-			if (needreport)
-				lastreport = jiffies;
-			firstreport = true;
-			WARN_ON(signal_pending(current));
-			list_for_each_entry_safe(t, t1, &rcu_tasks_holdouts,
-						rcu_tasks_holdout_list) {
-				check_holdout_task(t, needreport, &firstreport);
-				cond_resched();
-			}
-		}
-
-		/*
-		 * Because ->on_rq and ->nvcsw are not guaranteed
-		 * to have a full memory barriers prior to them in the
-		 * schedule() path, memory reordering on other CPUs could
-		 * cause their RCU-tasks read-side critical sections to
-		 * extend past the end of the grace period.  However,
-		 * because these ->nvcsw updates are carried out with
-		 * interrupts disabled, we can use synchronize_rcu()
-		 * to force the needed ordering on all such CPUs.
-		 *
-		 * This synchronize_rcu() also confines all
-		 * ->rcu_tasks_holdout accesses to be within the grace
-		 * period, avoiding the need for memory barriers for
-		 * ->rcu_tasks_holdout accesses.
-		 *
-		 * In addition, this synchronize_rcu() waits for exiting
-		 * tasks to complete their final preempt_disable() region
-		 * of execution, cleaning up after the synchronize_srcu()
-		 * above.
-		 */
-		synchronize_rcu();
-
-		/* Invoke the callbacks. */
-		while (list) {
-			next = list->next;
-			local_bh_disable();
-			list->func(list);
-			local_bh_enable();
-			list = next;
-			cond_resched();
-		}
-		/* Paranoid sleep to keep this from entering a tight loop */
-		schedule_timeout_uninterruptible(HZ/10);
-	}
-}
-
-/* Spawn rcu_tasks_kthread() at core_initcall() time. */
-static int __init rcu_spawn_tasks_kthread(void)
-{
-	struct task_struct *t;
-
-	t = kthread_run(rcu_tasks_kthread, NULL, "rcu_tasks_kthread");
-	if (WARN_ONCE(IS_ERR(t), "%s: Could not start Tasks-RCU grace-period kthread, OOM is now expected behavior\n", __func__))
-		return 0;
-	smp_mb(); /* Ensure others see full kthread. */
-	WRITE_ONCE(rcu_tasks_kthread_ptr, t);
-	return 0;
-}
-core_initcall(rcu_spawn_tasks_kthread);
-
-/* Do the srcu_read_lock() for the above synchronize_srcu().  */
-void exit_tasks_rcu_start(void)
-{
-	preempt_disable();
-	current->rcu_tasks_idx = __srcu_read_lock(&tasks_rcu_exit_srcu);
-	preempt_enable();
-}
-
-/* Do the srcu_read_unlock() for the above synchronize_srcu().  */
-void exit_tasks_rcu_finish(void)
-{
-	preempt_disable();
-	__srcu_read_unlock(&tasks_rcu_exit_srcu, current->rcu_tasks_idx);
-	preempt_enable();
-}
-
-#endif /* #ifdef CONFIG_TASKS_RCU */
-
-#ifndef CONFIG_TINY_RCU
-
-/*
- * Print any non-default Tasks RCU settings.
- */
-static void __init rcu_tasks_bootup_oddness(void)
-{
-#ifdef CONFIG_TASKS_RCU
-	if (rcu_task_stall_timeout != RCU_TASK_STALL_TIMEOUT)
-		pr_info("\tTasks-RCU CPU stall warnings timeout set to %d (rcu_task_stall_timeout).\n", rcu_task_stall_timeout);
-	else
-		pr_info("\tTasks RCU enabled.\n");
-#endif /* #ifdef CONFIG_TASKS_RCU */
-}
-
-#endif /* #ifndef CONFIG_TINY_RCU */
+// Suppress boot-time RCU CPU stall warnings and rcutorture writer stall
+// warnings.  Also used by rcutorture even if stall warnings are excluded.
+int rcu_cpu_stall_suppress_at_boot __read_mostly; // !0 = suppress boot stalls.
+EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress_at_boot);
+module_param(rcu_cpu_stall_suppress_at_boot, int, 0444);
 
 #ifdef CONFIG_PROVE_RCU
 
@@ -853,14 +523,22 @@
 
 DEFINE_STATIC_SRCU(early_srcu);
 
+struct early_boot_kfree_rcu {
+	struct rcu_head rh;
+};
+
 static void early_boot_test_call_rcu(void)
 {
 	static struct rcu_head head;
 	static struct rcu_head shead;
+	struct early_boot_kfree_rcu *rhp;
 
 	call_rcu(&head, test_callback);
 	if (IS_ENABLED(CONFIG_SRCU))
 		call_srcu(&early_srcu, &shead, test_callback);
+	rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
+	if (!WARN_ON_ONCE(!rhp))
+		kfree_rcu(rhp, rh);
 }
 
 void rcu_early_boot_tests(void)
@@ -897,6 +575,8 @@
 void rcu_early_boot_tests(void) {}
 #endif /* CONFIG_PROVE_RCU */
 
+#include "tasks.h"
+
 #ifndef CONFIG_TINY_RCU
 
 /*
diff --git a/kernel/reboot.c b/kernel/reboot.c
index ac19159..af6f23d 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -26,7 +26,7 @@
 struct pid *cad_pid;
 EXPORT_SYMBOL(cad_pid);
 
-#if defined(CONFIG_ARM) || defined(CONFIG_UNICORE32)
+#if defined(CONFIG_ARM)
 #define DEFAULT_REBOOT_MODE		= REBOOT_HARD
 #else
 #define DEFAULT_REBOOT_MODE
@@ -250,7 +250,7 @@
 		pr_emerg("Restarting system\n");
 	else
 		pr_emerg("Restarting system with command '%s'\n", cmd);
-	kmsg_dump(KMSG_DUMP_RESTART);
+	kmsg_dump(KMSG_DUMP_SHUTDOWN);
 	machine_restart(cmd);
 }
 EXPORT_SYMBOL_GPL(kernel_restart);
@@ -274,7 +274,7 @@
 	migrate_to_reboot_cpu();
 	syscore_shutdown();
 	pr_emerg("System halted\n");
-	kmsg_dump(KMSG_DUMP_HALT);
+	kmsg_dump(KMSG_DUMP_SHUTDOWN);
 	machine_halt();
 }
 EXPORT_SYMBOL_GPL(kernel_halt);
@@ -292,7 +292,7 @@
 	migrate_to_reboot_cpu();
 	syscore_shutdown();
 	pr_emerg("Power down\n");
-	kmsg_dump(KMSG_DUMP_POWEROFF);
+	kmsg_dump(KMSG_DUMP_SHUTDOWN);
 	machine_power_off();
 }
 EXPORT_SYMBOL_GPL(kernel_power_off);
diff --git a/kernel/regset.c b/kernel/regset.c
new file mode 100644
index 0000000..5868237
--- /dev/null
+++ b/kernel/regset.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/regset.h>
+
+static int __regset_get(struct task_struct *target,
+			const struct user_regset *regset,
+			unsigned int size,
+			void **data)
+{
+	void *p = *data, *to_free = NULL;
+	int res;
+
+	if (!regset->regset_get)
+		return -EOPNOTSUPP;
+	if (size > regset->n * regset->size)
+		size = regset->n * regset->size;
+	if (!p) {
+		to_free = p = kzalloc(size, GFP_KERNEL);
+		if (!p)
+			return -ENOMEM;
+	}
+	res = regset->regset_get(target, regset,
+			   (struct membuf){.p = p, .left = size});
+	if (res < 0) {
+		kfree(to_free);
+		return res;
+	}
+	*data = p;
+	return size - res;
+}
+
+int regset_get(struct task_struct *target,
+	       const struct user_regset *regset,
+	       unsigned int size,
+	       void *data)
+{
+	return __regset_get(target, regset, size, &data);
+}
+EXPORT_SYMBOL(regset_get);
+
+int regset_get_alloc(struct task_struct *target,
+		     const struct user_regset *regset,
+		     unsigned int size,
+		     void **data)
+{
+	*data = NULL;
+	return __regset_get(target, regset, size, data);
+}
+EXPORT_SYMBOL(regset_get_alloc);
+
+/**
+ * copy_regset_to_user - fetch a thread's user_regset data into user memory
+ * @target:	thread to be examined
+ * @view:	&struct user_regset_view describing user thread machine state
+ * @setno:	index in @view->regsets
+ * @offset:	offset into the regset data, in bytes
+ * @size:	amount of data to copy, in bytes
+ * @data:	user-mode pointer to copy into
+ */
+int copy_regset_to_user(struct task_struct *target,
+			const struct user_regset_view *view,
+			unsigned int setno,
+			unsigned int offset, unsigned int size,
+			void __user *data)
+{
+	const struct user_regset *regset = &view->regsets[setno];
+	void *buf;
+	int ret;
+
+	ret = regset_get_alloc(target, regset, size, &buf);
+	if (ret > 0)
+		ret = copy_to_user(data, buf, ret) ? -EFAULT : 0;
+	kfree(buf);
+	return ret;
+}
diff --git a/kernel/relay.c b/kernel/relay.c
index d3940be..b08d936 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1,7 +1,7 @@
 /*
  * Public API and common code for kernel->userspace relay file support.
  *
- * See Documentation/filesystems/relay.txt for an overview.
+ * See Documentation/filesystems/relay.rst for an overview.
  *
  * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
  * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
@@ -91,7 +91,7 @@
  *
  *	Returns 0 if ok, negative on error
  *
- *	Caller should already have grabbed mmap_sem.
+ *	Caller should already have grabbed mmap_lock.
  */
 static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
 {
@@ -997,14 +997,14 @@
 /*
  *	relay_file_read_avail - boolean, are there unconsumed bytes available?
  */
-static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
+static int relay_file_read_avail(struct rchan_buf *buf)
 {
 	size_t subbuf_size = buf->chan->subbuf_size;
 	size_t n_subbufs = buf->chan->n_subbufs;
 	size_t produced = buf->subbufs_produced;
-	size_t consumed = buf->subbufs_consumed;
+	size_t consumed;
 
-	relay_file_read_consume(buf, read_pos, 0);
+	relay_file_read_consume(buf, 0, 0);
 
 	consumed = buf->subbufs_consumed;
 
@@ -1065,23 +1065,20 @@
 
 /**
  *	relay_file_read_start_pos - find the first available byte to read
- *	@read_pos: file read position
  *	@buf: relay channel buffer
  *
- *	If the @read_pos is in the middle of padding, return the
+ *	If the read_pos is in the middle of padding, return the
  *	position of the first actually available byte, otherwise
  *	return the original value.
  */
-static size_t relay_file_read_start_pos(size_t read_pos,
-					struct rchan_buf *buf)
+static size_t relay_file_read_start_pos(struct rchan_buf *buf)
 {
 	size_t read_subbuf, padding, padding_start, padding_end;
 	size_t subbuf_size = buf->chan->subbuf_size;
 	size_t n_subbufs = buf->chan->n_subbufs;
 	size_t consumed = buf->subbufs_consumed % n_subbufs;
+	size_t read_pos = consumed * subbuf_size + buf->bytes_consumed;
 
-	if (!read_pos)
-		read_pos = consumed * subbuf_size + buf->bytes_consumed;
 	read_subbuf = read_pos / subbuf_size;
 	padding = buf->padding[read_subbuf];
 	padding_start = (read_subbuf + 1) * subbuf_size - padding;
@@ -1137,10 +1134,10 @@
 	do {
 		void *from;
 
-		if (!relay_file_read_avail(buf, *ppos))
+		if (!relay_file_read_avail(buf))
 			break;
 
-		read_start = relay_file_read_start_pos(*ppos, buf);
+		read_start = relay_file_read_start_pos(buf);
 		avail = relay_file_read_subbuf_avail(read_start, buf);
 		if (!avail)
 			break;
@@ -1183,10 +1180,9 @@
 }
 
 static const struct pipe_buf_operations relay_pipe_buf_ops = {
-	.confirm = generic_pipe_buf_confirm,
-	.release = relay_pipe_buf_release,
-	.steal = generic_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
+	.release	= relay_pipe_buf_release,
+	.try_steal	= generic_pipe_buf_try_steal,
+	.get		= generic_pipe_buf_get,
 };
 
 static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i)
diff --git a/kernel/resource.c b/kernel/resource.c
index 841737b..817545f 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -382,10 +382,13 @@
 
 	if (p) {
 		/* copy data */
-		res->start = max(start, p->start);
-		res->end = min(end, p->end);
-		res->flags = p->flags;
-		res->desc = p->desc;
+		*res = (struct resource) {
+			.start = max(start, p->start),
+			.end = min(end, p->end),
+			.flags = p->flags,
+			.desc = p->desc,
+			.parent = p->parent,
+		};
 	}
 
 	read_unlock(&resource_lock);
@@ -447,7 +450,7 @@
 {
 	unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 
-	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
+	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false,
 				     arg, func);
 }
 
@@ -460,7 +463,7 @@
 {
 	unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 
-	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
+	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false,
 				     arg, func);
 }
 
@@ -1237,7 +1240,6 @@
 #ifdef CONFIG_MEMORY_HOTREMOVE
 /**
  * release_mem_region_adjustable - release a previously reserved memory region
- * @parent: parent resource descriptor
  * @start: resource start address
  * @size: resource region size
  *
@@ -1255,21 +1257,28 @@
  *   assumes that all children remain in the lower address entry for
  *   simplicity.  Enhance this logic when necessary.
  */
-int release_mem_region_adjustable(struct resource *parent,
-				  resource_size_t start, resource_size_t size)
+void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
 {
+	struct resource *parent = &iomem_resource;
+	struct resource *new_res = NULL;
+	bool alloc_nofail = false;
 	struct resource **p;
 	struct resource *res;
-	struct resource *new_res;
 	resource_size_t end;
-	int ret = -EINVAL;
 
 	end = start + size - 1;
-	if ((start < parent->start) || (end > parent->end))
-		return ret;
+	if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
+		return;
 
-	/* The alloc_resource() result gets checked later */
-	new_res = alloc_resource(GFP_KERNEL);
+	/*
+	 * We free up quite a lot of memory on memory hotunplug (esp., memap),
+	 * just before releasing the region. This is highly unlikely to
+	 * fail - let's play save and make it never fail as the caller cannot
+	 * perform any error handling (e.g., trying to re-add memory will fail
+	 * similarly).
+	 */
+retry:
+	new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
 
 	p = &parent->child;
 	write_lock(&resource_lock);
@@ -1295,7 +1304,6 @@
 		 * so if we are dealing with them, let us just back off here.
 		 */
 		if (!(res->flags & IORESOURCE_SYSRAM)) {
-			ret = 0;
 			break;
 		}
 
@@ -1312,20 +1320,23 @@
 			/* free the whole entry */
 			*p = res->sibling;
 			free_resource(res);
-			ret = 0;
 		} else if (res->start == start && res->end != end) {
 			/* adjust the start */
-			ret = __adjust_resource(res, end + 1,
-						res->end - end);
+			WARN_ON_ONCE(__adjust_resource(res, end + 1,
+						       res->end - end));
 		} else if (res->start != start && res->end == end) {
 			/* adjust the end */
-			ret = __adjust_resource(res, res->start,
-						start - res->start);
+			WARN_ON_ONCE(__adjust_resource(res, res->start,
+						       start - res->start));
 		} else {
-			/* split into two entries */
+			/* split into two entries - we need a new resource */
 			if (!new_res) {
-				ret = -ENOMEM;
-				break;
+				new_res = alloc_resource(GFP_ATOMIC);
+				if (!new_res) {
+					alloc_nofail = true;
+					write_unlock(&resource_lock);
+					goto retry;
+				}
 			}
 			new_res->name = res->name;
 			new_res->start = end + 1;
@@ -1336,9 +1347,8 @@
 			new_res->sibling = res->sibling;
 			new_res->child = NULL;
 
-			ret = __adjust_resource(res, res->start,
-						start - res->start);
-			if (ret)
+			if (WARN_ON_ONCE(__adjust_resource(res, res->start,
+							   start - res->start)))
 				break;
 			res->sibling = new_res;
 			new_res = NULL;
@@ -1349,10 +1359,69 @@
 
 	write_unlock(&resource_lock);
 	free_resource(new_res);
-	return ret;
 }
 #endif	/* CONFIG_MEMORY_HOTREMOVE */
 
+#ifdef CONFIG_MEMORY_HOTPLUG
+static bool system_ram_resources_mergeable(struct resource *r1,
+					   struct resource *r2)
+{
+	/* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
+	return r1->flags == r2->flags && r1->end + 1 == r2->start &&
+	       r1->name == r2->name && r1->desc == r2->desc &&
+	       !r1->child && !r2->child;
+}
+
+/*
+ * merge_system_ram_resource - mark the System RAM resource mergeable and try to
+ * merge it with adjacent, mergeable resources
+ * @res: resource descriptor
+ *
+ * This interface is intended for memory hotplug, whereby lots of contiguous
+ * system ram resources are added (e.g., via add_memory*()) by a driver, and
+ * the actual resource boundaries are not of interest (e.g., it might be
+ * relevant for DIMMs). Only resources that are marked mergeable, that have the
+ * same parent, and that don't have any children are considered. All mergeable
+ * resources must be immutable during the request.
+ *
+ * Note:
+ * - The caller has to make sure that no pointers to resources that are
+ *   marked mergeable are used anymore after this call - the resource might
+ *   be freed and the pointer might be stale!
+ * - release_mem_region_adjustable() will split on demand on memory hotunplug
+ */
+void merge_system_ram_resource(struct resource *res)
+{
+	const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+	struct resource *cur;
+
+	if (WARN_ON_ONCE((res->flags & flags) != flags))
+		return;
+
+	write_lock(&resource_lock);
+	res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
+
+	/* Try to merge with next item in the list. */
+	cur = res->sibling;
+	if (cur && system_ram_resources_mergeable(res, cur)) {
+		res->end = cur->end;
+		res->sibling = cur->sibling;
+		free_resource(cur);
+	}
+
+	/* Try to merge with previous item in the list. */
+	cur = res->parent->child;
+	while (cur && cur->sibling != res)
+		cur = cur->sibling;
+	if (cur && system_ram_resources_mergeable(cur, res)) {
+		cur->end = res->end;
+		cur->sibling = res->sibling;
+		free_resource(res);
+	}
+	write_unlock(&resource_lock);
+}
+#endif	/* CONFIG_MEMORY_HOTPLUG */
+
 /*
  * Managed region resource
  */
diff --git a/kernel/rseq.c b/kernel/rseq.c
index 27c48eb..0077713 100644
--- a/kernel/rseq.c
+++ b/kernel/rseq.c
@@ -268,9 +268,16 @@
 		return;
 	if (unlikely(!access_ok(t->rseq, sizeof(*t->rseq))))
 		goto error;
-	ret = rseq_ip_fixup(regs);
-	if (unlikely(ret < 0))
-		goto error;
+	/*
+	 * regs is NULL if and only if the caller is in a syscall path.  Skip
+	 * fixup and leave rseq_cs as is so that rseq_sycall() will detect and
+	 * kill a misbehaving userspace on debug kernels.
+	 */
+	if (regs) {
+		ret = rseq_ip_fixup(regs);
+		if (unlikely(ret < 0))
+			goto error;
+	}
 	if (unlikely(rseq_update_cpu_id(t)))
 		goto error;
 	return;
@@ -310,6 +317,8 @@
 	int ret;
 
 	if (flags & RSEQ_FLAG_UNREGISTER) {
+		if (flags & ~RSEQ_FLAG_UNREGISTER)
+			return -EINVAL;
 		/* Unregister rseq for current thread. */
 		if (current->rseq != rseq || !current->rseq)
 			return -EINVAL;
diff --git a/kernel/scftorture.c b/kernel/scftorture.c
new file mode 100644
index 0000000..554a521
--- /dev/null
+++ b/kernel/scftorture.c
@@ -0,0 +1,575 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Torture test for smp_call_function() and friends.
+//
+// Copyright (C) Facebook, 2020.
+//
+// Author: Paul E. McKenney <paulmck@kernel.org>
+
+#define pr_fmt(fmt) fmt
+
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kthread.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/notifier.h>
+#include <linux/percpu.h>
+#include <linux/rcupdate.h>
+#include <linux/rcupdate_trace.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/stat.h>
+#include <linux/srcu.h>
+#include <linux/slab.h>
+#include <linux/torture.h>
+#include <linux/types.h>
+
+#define SCFTORT_STRING "scftorture"
+#define SCFTORT_FLAG SCFTORT_STRING ": "
+
+#define SCFTORTOUT(s, x...) \
+	pr_alert(SCFTORT_FLAG s, ## x)
+
+#define VERBOSE_SCFTORTOUT(s, x...) \
+	do { if (verbose) pr_alert(SCFTORT_FLAG s, ## x); } while (0)
+
+#define VERBOSE_SCFTORTOUT_ERRSTRING(s, x...) \
+	do { if (verbose) pr_alert(SCFTORT_FLAG "!!! " s, ## x); } while (0)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul E. McKenney <paulmck@kernel.org>");
+
+// Wait until there are multiple CPUs before starting test.
+torture_param(int, holdoff, IS_BUILTIN(CONFIG_SCF_TORTURE_TEST) ? 10 : 0,
+	      "Holdoff time before test start (s)");
+torture_param(int, longwait, 0, "Include ridiculously long waits? (seconds)");
+torture_param(int, nthreads, -1, "# threads, defaults to -1 for all CPUs.");
+torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
+torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (s), 0=disable");
+torture_param(int, shutdown_secs, 0, "Shutdown time (ms), <= zero to disable.");
+torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s.");
+torture_param(int, stutter_cpus, 5, "Number of jiffies to change CPUs under test, 0=disable");
+torture_param(bool, use_cpus_read_lock, 0, "Use cpus_read_lock() to exclude CPU hotplug.");
+torture_param(int, verbose, 0, "Enable verbose debugging printk()s");
+torture_param(int, weight_single, -1, "Testing weight for single-CPU no-wait operations.");
+torture_param(int, weight_single_wait, -1, "Testing weight for single-CPU operations.");
+torture_param(int, weight_many, -1, "Testing weight for multi-CPU no-wait operations.");
+torture_param(int, weight_many_wait, -1, "Testing weight for multi-CPU operations.");
+torture_param(int, weight_all, -1, "Testing weight for all-CPU no-wait operations.");
+torture_param(int, weight_all_wait, -1, "Testing weight for all-CPU operations.");
+
+char *torture_type = "";
+
+#ifdef MODULE
+# define SCFTORT_SHUTDOWN 0
+#else
+# define SCFTORT_SHUTDOWN 1
+#endif
+
+torture_param(bool, shutdown, SCFTORT_SHUTDOWN, "Shutdown at end of torture test.");
+
+struct scf_statistics {
+	struct task_struct *task;
+	int cpu;
+	long long n_single;
+	long long n_single_ofl;
+	long long n_single_wait;
+	long long n_single_wait_ofl;
+	long long n_many;
+	long long n_many_wait;
+	long long n_all;
+	long long n_all_wait;
+};
+
+static struct scf_statistics *scf_stats_p;
+static struct task_struct *scf_torture_stats_task;
+static DEFINE_PER_CPU(long long, scf_invoked_count);
+
+// Data for random primitive selection
+#define SCF_PRIM_SINGLE		0
+#define SCF_PRIM_MANY		1
+#define SCF_PRIM_ALL		2
+#define SCF_NPRIMS		(2 * 3) // Need wait and no-wait versions of each.
+
+static char *scf_prim_name[] = {
+	"smp_call_function_single",
+	"smp_call_function_many",
+	"smp_call_function",
+};
+
+struct scf_selector {
+	unsigned long scfs_weight;
+	int scfs_prim;
+	bool scfs_wait;
+};
+static struct scf_selector scf_sel_array[SCF_NPRIMS];
+static int scf_sel_array_len;
+static unsigned long scf_sel_totweight;
+
+// Communicate between caller and handler.
+struct scf_check {
+	bool scfc_in;
+	bool scfc_out;
+	int scfc_cpu; // -1 for not _single().
+	bool scfc_wait;
+};
+
+// Use to wait for all threads to start.
+static atomic_t n_started;
+static atomic_t n_errs;
+static atomic_t n_mb_in_errs;
+static atomic_t n_mb_out_errs;
+static atomic_t n_alloc_errs;
+static bool scfdone;
+static char *bangstr = "";
+
+static DEFINE_TORTURE_RANDOM_PERCPU(scf_torture_rand);
+
+// Print torture statistics.  Caller must ensure serialization.
+static void scf_torture_stats_print(void)
+{
+	int cpu;
+	int i;
+	long long invoked_count = 0;
+	bool isdone = READ_ONCE(scfdone);
+	struct scf_statistics scfs = {};
+
+	for_each_possible_cpu(cpu)
+		invoked_count += data_race(per_cpu(scf_invoked_count, cpu));
+	for (i = 0; i < nthreads; i++) {
+		scfs.n_single += scf_stats_p[i].n_single;
+		scfs.n_single_ofl += scf_stats_p[i].n_single_ofl;
+		scfs.n_single_wait += scf_stats_p[i].n_single_wait;
+		scfs.n_single_wait_ofl += scf_stats_p[i].n_single_wait_ofl;
+		scfs.n_many += scf_stats_p[i].n_many;
+		scfs.n_many_wait += scf_stats_p[i].n_many_wait;
+		scfs.n_all += scf_stats_p[i].n_all;
+		scfs.n_all_wait += scf_stats_p[i].n_all_wait;
+	}
+	if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) ||
+	    atomic_read(&n_mb_out_errs) || atomic_read(&n_alloc_errs))
+		bangstr = "!!! ";
+	pr_alert("%s %sscf_invoked_count %s: %lld single: %lld/%lld single_ofl: %lld/%lld many: %lld/%lld all: %lld/%lld ",
+		 SCFTORT_FLAG, bangstr, isdone ? "VER" : "ver", invoked_count,
+		 scfs.n_single, scfs.n_single_wait, scfs.n_single_ofl, scfs.n_single_wait_ofl,
+		 scfs.n_many, scfs.n_many_wait, scfs.n_all, scfs.n_all_wait);
+	torture_onoff_stats();
+	pr_cont("ste: %d stnmie: %d stnmoe: %d staf: %d\n", atomic_read(&n_errs),
+		atomic_read(&n_mb_in_errs), atomic_read(&n_mb_out_errs),
+		atomic_read(&n_alloc_errs));
+}
+
+// Periodically prints torture statistics, if periodic statistics printing
+// was specified via the stat_interval module parameter.
+static int
+scf_torture_stats(void *arg)
+{
+	VERBOSE_TOROUT_STRING("scf_torture_stats task started");
+	do {
+		schedule_timeout_interruptible(stat_interval * HZ);
+		scf_torture_stats_print();
+		torture_shutdown_absorb("scf_torture_stats");
+	} while (!torture_must_stop());
+	torture_kthread_stopping("scf_torture_stats");
+	return 0;
+}
+
+// Add a primitive to the scf_sel_array[].
+static void scf_sel_add(unsigned long weight, int prim, bool wait)
+{
+	struct scf_selector *scfsp = &scf_sel_array[scf_sel_array_len];
+
+	// If no weight, if array would overflow, if computing three-place
+	// percentages would overflow, or if the scf_prim_name[] array would
+	// overflow, don't bother.  In the last three two cases, complain.
+	if (!weight ||
+	    WARN_ON_ONCE(scf_sel_array_len >= ARRAY_SIZE(scf_sel_array)) ||
+	    WARN_ON_ONCE(0 - 100000 * weight <= 100000 * scf_sel_totweight) ||
+	    WARN_ON_ONCE(prim >= ARRAY_SIZE(scf_prim_name)))
+		return;
+	scf_sel_totweight += weight;
+	scfsp->scfs_weight = scf_sel_totweight;
+	scfsp->scfs_prim = prim;
+	scfsp->scfs_wait = wait;
+	scf_sel_array_len++;
+}
+
+// Dump out weighting percentages for scf_prim_name[] array.
+static void scf_sel_dump(void)
+{
+	int i;
+	unsigned long oldw = 0;
+	struct scf_selector *scfsp;
+	unsigned long w;
+
+	for (i = 0; i < scf_sel_array_len; i++) {
+		scfsp = &scf_sel_array[i];
+		w = (scfsp->scfs_weight - oldw) * 100000 / scf_sel_totweight;
+		pr_info("%s: %3lu.%03lu %s(%s)\n", __func__, w / 1000, w % 1000,
+			scf_prim_name[scfsp->scfs_prim],
+			scfsp->scfs_wait ? "wait" : "nowait");
+		oldw = scfsp->scfs_weight;
+	}
+}
+
+// Randomly pick a primitive and wait/nowait, based on weightings.
+static struct scf_selector *scf_sel_rand(struct torture_random_state *trsp)
+{
+	int i;
+	unsigned long w = torture_random(trsp) % (scf_sel_totweight + 1);
+
+	for (i = 0; i < scf_sel_array_len; i++)
+		if (scf_sel_array[i].scfs_weight >= w)
+			return &scf_sel_array[i];
+	WARN_ON_ONCE(1);
+	return &scf_sel_array[0];
+}
+
+// Update statistics and occasionally burn up mass quantities of CPU time,
+// if told to do so via scftorture.longwait.  Otherwise, occasionally burn
+// a little bit.
+static void scf_handler(void *scfc_in)
+{
+	int i;
+	int j;
+	unsigned long r = torture_random(this_cpu_ptr(&scf_torture_rand));
+	struct scf_check *scfcp = scfc_in;
+
+	if (likely(scfcp)) {
+		WRITE_ONCE(scfcp->scfc_out, false); // For multiple receivers.
+		if (WARN_ON_ONCE(unlikely(!READ_ONCE(scfcp->scfc_in))))
+			atomic_inc(&n_mb_in_errs);
+	}
+	this_cpu_inc(scf_invoked_count);
+	if (longwait <= 0) {
+		if (!(r & 0xffc0))
+			udelay(r & 0x3f);
+		goto out;
+	}
+	if (r & 0xfff)
+		goto out;
+	r = (r >> 12);
+	if (longwait <= 0) {
+		udelay((r & 0xff) + 1);
+		goto out;
+	}
+	r = r % longwait + 1;
+	for (i = 0; i < r; i++) {
+		for (j = 0; j < 1000; j++) {
+			udelay(1000);
+			cpu_relax();
+		}
+	}
+out:
+	if (unlikely(!scfcp))
+		return;
+	if (scfcp->scfc_wait)
+		WRITE_ONCE(scfcp->scfc_out, true);
+	else
+		kfree(scfcp);
+}
+
+// As above, but check for correct CPU.
+static void scf_handler_1(void *scfc_in)
+{
+	struct scf_check *scfcp = scfc_in;
+
+	if (likely(scfcp) && WARN_ONCE(smp_processor_id() != scfcp->scfc_cpu, "%s: Wanted CPU %d got CPU %d\n", __func__, scfcp->scfc_cpu, smp_processor_id())) {
+		atomic_inc(&n_errs);
+	}
+	scf_handler(scfcp);
+}
+
+// Randomly do an smp_call_function*() invocation.
+static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_random_state *trsp)
+{
+	uintptr_t cpu;
+	int ret = 0;
+	struct scf_check *scfcp = NULL;
+	struct scf_selector *scfsp = scf_sel_rand(trsp);
+
+	if (use_cpus_read_lock)
+		cpus_read_lock();
+	else
+		preempt_disable();
+	if (scfsp->scfs_prim == SCF_PRIM_SINGLE || scfsp->scfs_wait) {
+		scfcp = kmalloc(sizeof(*scfcp), GFP_ATOMIC);
+		if (WARN_ON_ONCE(!scfcp)) {
+			atomic_inc(&n_alloc_errs);
+		} else {
+			scfcp->scfc_cpu = -1;
+			scfcp->scfc_wait = scfsp->scfs_wait;
+			scfcp->scfc_out = false;
+		}
+	}
+	switch (scfsp->scfs_prim) {
+	case SCF_PRIM_SINGLE:
+		cpu = torture_random(trsp) % nr_cpu_ids;
+		if (scfsp->scfs_wait)
+			scfp->n_single_wait++;
+		else
+			scfp->n_single++;
+		if (scfcp) {
+			scfcp->scfc_cpu = cpu;
+			barrier(); // Prevent race-reduction compiler optimizations.
+			scfcp->scfc_in = true;
+		}
+		ret = smp_call_function_single(cpu, scf_handler_1, (void *)scfcp, scfsp->scfs_wait);
+		if (ret) {
+			if (scfsp->scfs_wait)
+				scfp->n_single_wait_ofl++;
+			else
+				scfp->n_single_ofl++;
+			kfree(scfcp);
+			scfcp = NULL;
+		}
+		break;
+	case SCF_PRIM_MANY:
+		if (scfsp->scfs_wait)
+			scfp->n_many_wait++;
+		else
+			scfp->n_many++;
+		if (scfcp) {
+			barrier(); // Prevent race-reduction compiler optimizations.
+			scfcp->scfc_in = true;
+		}
+		smp_call_function_many(cpu_online_mask, scf_handler, scfcp, scfsp->scfs_wait);
+		break;
+	case SCF_PRIM_ALL:
+		if (scfsp->scfs_wait)
+			scfp->n_all_wait++;
+		else
+			scfp->n_all++;
+		if (scfcp) {
+			barrier(); // Prevent race-reduction compiler optimizations.
+			scfcp->scfc_in = true;
+		}
+		smp_call_function(scf_handler, scfcp, scfsp->scfs_wait);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		if (scfcp)
+			scfcp->scfc_out = true;
+	}
+	if (scfcp && scfsp->scfs_wait) {
+		if (WARN_ON_ONCE((num_online_cpus() > 1 || scfsp->scfs_prim == SCF_PRIM_SINGLE) &&
+				 !scfcp->scfc_out))
+			atomic_inc(&n_mb_out_errs); // Leak rather than trash!
+		else
+			kfree(scfcp);
+		barrier(); // Prevent race-reduction compiler optimizations.
+	}
+	if (use_cpus_read_lock)
+		cpus_read_unlock();
+	else
+		preempt_enable();
+	if (!(torture_random(trsp) & 0xfff))
+		schedule_timeout_uninterruptible(1);
+}
+
+// SCF test kthread.  Repeatedly does calls to members of the
+// smp_call_function() family of functions.
+static int scftorture_invoker(void *arg)
+{
+	int cpu;
+	DEFINE_TORTURE_RANDOM(rand);
+	struct scf_statistics *scfp = (struct scf_statistics *)arg;
+	bool was_offline = false;
+
+	VERBOSE_SCFTORTOUT("scftorture_invoker %d: task started", scfp->cpu);
+	cpu = scfp->cpu % nr_cpu_ids;
+	set_cpus_allowed_ptr(current, cpumask_of(cpu));
+	set_user_nice(current, MAX_NICE);
+	if (holdoff)
+		schedule_timeout_interruptible(holdoff * HZ);
+
+	VERBOSE_SCFTORTOUT("scftorture_invoker %d: Waiting for all SCF torturers from cpu %d", scfp->cpu, smp_processor_id());
+
+	// Make sure that the CPU is affinitized appropriately during testing.
+	WARN_ON_ONCE(smp_processor_id() != scfp->cpu);
+
+	if (!atomic_dec_return(&n_started))
+		while (atomic_read_acquire(&n_started)) {
+			if (torture_must_stop()) {
+				VERBOSE_SCFTORTOUT("scftorture_invoker %d ended before starting", scfp->cpu);
+				goto end;
+			}
+			schedule_timeout_uninterruptible(1);
+		}
+
+	VERBOSE_SCFTORTOUT("scftorture_invoker %d started", scfp->cpu);
+
+	do {
+		scftorture_invoke_one(scfp, &rand);
+		while (cpu_is_offline(cpu) && !torture_must_stop()) {
+			schedule_timeout_interruptible(HZ / 5);
+			was_offline = true;
+		}
+		if (was_offline) {
+			set_cpus_allowed_ptr(current, cpumask_of(cpu));
+			was_offline = false;
+		}
+		cond_resched();
+	} while (!torture_must_stop());
+
+	VERBOSE_SCFTORTOUT("scftorture_invoker %d ended", scfp->cpu);
+end:
+	torture_kthread_stopping("scftorture_invoker");
+	return 0;
+}
+
+static void
+scftorture_print_module_parms(const char *tag)
+{
+	pr_alert(SCFTORT_FLAG
+		 "--- %s:  verbose=%d holdoff=%d longwait=%d nthreads=%d onoff_holdoff=%d onoff_interval=%d shutdown_secs=%d stat_interval=%d stutter_cpus=%d use_cpus_read_lock=%d, weight_single=%d, weight_single_wait=%d, weight_many=%d, weight_many_wait=%d, weight_all=%d, weight_all_wait=%d\n", tag,
+		 verbose, holdoff, longwait, nthreads, onoff_holdoff, onoff_interval, shutdown, stat_interval, stutter_cpus, use_cpus_read_lock, weight_single, weight_single_wait, weight_many, weight_many_wait, weight_all, weight_all_wait);
+}
+
+static void scf_cleanup_handler(void *unused)
+{
+}
+
+static void scf_torture_cleanup(void)
+{
+	int i;
+
+	if (torture_cleanup_begin())
+		return;
+
+	WRITE_ONCE(scfdone, true);
+	if (nthreads)
+		for (i = 0; i < nthreads; i++)
+			torture_stop_kthread("scftorture_invoker", scf_stats_p[i].task);
+	else
+		goto end;
+	smp_call_function(scf_cleanup_handler, NULL, 0);
+	torture_stop_kthread(scf_torture_stats, scf_torture_stats_task);
+	scf_torture_stats_print();  // -After- the stats thread is stopped!
+	kfree(scf_stats_p);  // -After- the last stats print has completed!
+	scf_stats_p = NULL;
+
+	if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) || atomic_read(&n_mb_out_errs))
+		scftorture_print_module_parms("End of test: FAILURE");
+	else if (torture_onoff_failures())
+		scftorture_print_module_parms("End of test: LOCK_HOTPLUG");
+	else
+		scftorture_print_module_parms("End of test: SUCCESS");
+
+end:
+	torture_cleanup_end();
+}
+
+static int __init scf_torture_init(void)
+{
+	long i;
+	int firsterr = 0;
+	unsigned long weight_single1 = weight_single;
+	unsigned long weight_single_wait1 = weight_single_wait;
+	unsigned long weight_many1 = weight_many;
+	unsigned long weight_many_wait1 = weight_many_wait;
+	unsigned long weight_all1 = weight_all;
+	unsigned long weight_all_wait1 = weight_all_wait;
+
+	if (!torture_init_begin(SCFTORT_STRING, verbose))
+		return -EBUSY;
+
+	scftorture_print_module_parms("Start of test");
+
+	if (weight_single == -1 && weight_single_wait == -1 &&
+	    weight_many == -1 && weight_many_wait == -1 &&
+	    weight_all == -1 && weight_all_wait == -1) {
+		weight_single1 = 2 * nr_cpu_ids;
+		weight_single_wait1 = 2 * nr_cpu_ids;
+		weight_many1 = 2;
+		weight_many_wait1 = 2;
+		weight_all1 = 1;
+		weight_all_wait1 = 1;
+	} else {
+		if (weight_single == -1)
+			weight_single1 = 0;
+		if (weight_single_wait == -1)
+			weight_single_wait1 = 0;
+		if (weight_many == -1)
+			weight_many1 = 0;
+		if (weight_many_wait == -1)
+			weight_many_wait1 = 0;
+		if (weight_all == -1)
+			weight_all1 = 0;
+		if (weight_all_wait == -1)
+			weight_all_wait1 = 0;
+	}
+	if (weight_single1 == 0 && weight_single_wait1 == 0 &&
+	    weight_many1 == 0 && weight_many_wait1 == 0 &&
+	    weight_all1 == 0 && weight_all_wait1 == 0) {
+		VERBOSE_SCFTORTOUT_ERRSTRING("all zero weights makes no sense");
+		firsterr = -EINVAL;
+		goto unwind;
+	}
+	scf_sel_add(weight_single1, SCF_PRIM_SINGLE, false);
+	scf_sel_add(weight_single_wait1, SCF_PRIM_SINGLE, true);
+	scf_sel_add(weight_many1, SCF_PRIM_MANY, false);
+	scf_sel_add(weight_many_wait1, SCF_PRIM_MANY, true);
+	scf_sel_add(weight_all1, SCF_PRIM_ALL, false);
+	scf_sel_add(weight_all_wait1, SCF_PRIM_ALL, true);
+	scf_sel_dump();
+
+	if (onoff_interval > 0) {
+		firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, NULL);
+		if (firsterr)
+			goto unwind;
+	}
+	if (shutdown_secs > 0) {
+		firsterr = torture_shutdown_init(shutdown_secs, scf_torture_cleanup);
+		if (firsterr)
+			goto unwind;
+	}
+
+	// Worker tasks invoking smp_call_function().
+	if (nthreads < 0)
+		nthreads = num_online_cpus();
+	scf_stats_p = kcalloc(nthreads, sizeof(scf_stats_p[0]), GFP_KERNEL);
+	if (!scf_stats_p) {
+		VERBOSE_SCFTORTOUT_ERRSTRING("out of memory");
+		firsterr = -ENOMEM;
+		goto unwind;
+	}
+
+	VERBOSE_SCFTORTOUT("Starting %d smp_call_function() threads\n", nthreads);
+
+	atomic_set(&n_started, nthreads);
+	for (i = 0; i < nthreads; i++) {
+		scf_stats_p[i].cpu = i;
+		firsterr = torture_create_kthread(scftorture_invoker, (void *)&scf_stats_p[i],
+						  scf_stats_p[i].task);
+		if (firsterr)
+			goto unwind;
+	}
+	if (stat_interval > 0) {
+		firsterr = torture_create_kthread(scf_torture_stats, NULL, scf_torture_stats_task);
+		if (firsterr)
+			goto unwind;
+	}
+
+	torture_init_end();
+	return 0;
+
+unwind:
+	torture_init_end();
+	scf_torture_cleanup();
+	return firsterr;
+}
+
+module_init(scf_torture_init);
+module_exit(scf_torture_cleanup);
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 21fb5a5..5fc9c9b 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -7,6 +7,12 @@
 # that is not a function of syscall inputs. E.g. involuntary context switches.
 KCOV_INSTRUMENT := n
 
+# There are numerous data races here, however, most of them are due to plain accesses.
+# This would make it even harder for syzbot to find reproducers, because these
+# bugs trigger without specific input. Disable by default, but should re-enable
+# eventually.
+KCSAN_SANITIZE := n
+
 ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
 # needed for x86 only.  Why this used to be enabled for all architectures is beyond
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 1152259..12bca64 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -370,7 +370,7 @@
 	if (sched_clock_stable())
 		return sched_clock() + __sched_clock_offset;
 
-	if (!static_branch_unlikely(&sched_clock_running))
+	if (!static_branch_likely(&sched_clock_running))
 		return sched_clock();
 
 	preempt_disable_notrace();
@@ -393,7 +393,7 @@
 	if (sched_clock_stable())
 		return;
 
-	if (!static_branch_unlikely(&sched_clock_running))
+	if (!static_branch_likely(&sched_clock_running))
 		return;
 
 	lockdep_assert_irqs_disabled();
@@ -460,7 +460,7 @@
 
 u64 sched_clock_cpu(int cpu)
 {
-	if (!static_branch_unlikely(&sched_clock_running))
+	if (!static_branch_likely(&sched_clock_running))
 		return 0;
 
 	return sched_clock();
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index a1ad5b7..a778554 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -29,12 +29,12 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 
 	if (x->done != UINT_MAX)
 		x->done++;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 1);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	swake_up_locked(&x->wait);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete);
 
@@ -58,10 +58,12 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	lockdep_assert_RT_in_threaded_ctx();
+
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	x->done = UINT_MAX;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 0);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	swake_up_all_locked(&x->wait);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete_all);
 
@@ -70,20 +72,20 @@
 		   long (*action)(long), long timeout, int state)
 {
 	if (!x->done) {
-		DECLARE_WAITQUEUE(wait, current);
+		DECLARE_SWAITQUEUE(wait);
 
-		__add_wait_queue_entry_tail_exclusive(&x->wait, &wait);
 		do {
 			if (signal_pending_state(state, current)) {
 				timeout = -ERESTARTSYS;
 				break;
 			}
+			__prepare_to_swait(&x->wait, &wait);
 			__set_current_state(state);
-			spin_unlock_irq(&x->wait.lock);
+			raw_spin_unlock_irq(&x->wait.lock);
 			timeout = action(timeout);
-			spin_lock_irq(&x->wait.lock);
+			raw_spin_lock_irq(&x->wait.lock);
 		} while (!x->done && timeout);
-		__remove_wait_queue(&x->wait, &wait);
+		__finish_swait(&x->wait, &wait);
 		if (!x->done)
 			return timeout;
 	}
@@ -100,9 +102,9 @@
 
 	complete_acquire(x);
 
-	spin_lock_irq(&x->wait.lock);
+	raw_spin_lock_irq(&x->wait.lock);
 	timeout = do_wait_for_common(x, action, timeout, state);
-	spin_unlock_irq(&x->wait.lock);
+	raw_spin_unlock_irq(&x->wait.lock);
 
 	complete_release(x);
 
@@ -291,12 +293,12 @@
 	if (!READ_ONCE(x->done))
 		return false;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	if (!x->done)
 		ret = false;
 	else if (x->done != UINT_MAX)
 		x->done--;
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(try_wait_for_completion);
@@ -322,8 +324,8 @@
 	 * otherwise we can end up freeing the completion before complete()
 	 * is done referencing it.
 	 */
-	spin_lock_irqsave(&x->wait.lock, flags);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 	return true;
 }
 EXPORT_SYMBOL(completion_done);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5dc43d3..0a5f9fa 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6,22 +6,26 @@
  *
  *  Copyright (C) 1991-2002  Linus Torvalds
  */
+#define CREATE_TRACE_POINTS
+#include <trace/events/sched.h>
+#undef CREATE_TRACE_POINTS
+
 #include "sched.h"
 
 #include <linux/nospec.h>
 
 #include <linux/kcov.h>
+#include <linux/scs.h>
 
 #include <asm/switch_to.h>
 #include <asm/tlb.h>
 
 #include "../workqueue_internal.h"
+#include "../../fs/io-wq.h"
 #include "../smpboot.h"
 
 #include "pelt.h"
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/sched.h>
+#include "smp.h"
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -32,7 +36,11 @@
 EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_dl_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_se_tp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(sched_cpu_capacity_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(sched_overutilized_tp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_cfs_tp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_se_tp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(sched_update_nr_running_tp);
 
 DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
@@ -72,6 +80,100 @@
  */
 int sysctl_sched_rt_runtime = 950000;
 
+
+/*
+ * Serialization rules:
+ *
+ * Lock order:
+ *
+ *   p->pi_lock
+ *     rq->lock
+ *       hrtimer_cpu_base->lock (hrtimer_start() for bandwidth controls)
+ *
+ *  rq1->lock
+ *    rq2->lock  where: rq1 < rq2
+ *
+ * Regular state:
+ *
+ * Normal scheduling state is serialized by rq->lock. __schedule() takes the
+ * local CPU's rq->lock, it optionally removes the task from the runqueue and
+ * always looks at the local rq data structures to find the most elegible task
+ * to run next.
+ *
+ * Task enqueue is also under rq->lock, possibly taken from another CPU.
+ * Wakeups from another LLC domain might use an IPI to transfer the enqueue to
+ * the local CPU to avoid bouncing the runqueue state around [ see
+ * ttwu_queue_wakelist() ]
+ *
+ * Task wakeup, specifically wakeups that involve migration, are horribly
+ * complicated to avoid having to take two rq->locks.
+ *
+ * Special state:
+ *
+ * System-calls and anything external will use task_rq_lock() which acquires
+ * both p->pi_lock and rq->lock. As a consequence the state they change is
+ * stable while holding either lock:
+ *
+ *  - sched_setaffinity()/
+ *    set_cpus_allowed_ptr():	p->cpus_ptr, p->nr_cpus_allowed
+ *  - set_user_nice():		p->se.load, p->*prio
+ *  - __sched_setscheduler():	p->sched_class, p->policy, p->*prio,
+ *				p->se.load, p->rt_priority,
+ *				p->dl.dl_{runtime, deadline, period, flags, bw, density}
+ *  - sched_setnuma():		p->numa_preferred_nid
+ *  - sched_move_task()/
+ *    cpu_cgroup_fork():	p->sched_task_group
+ *  - uclamp_update_active()	p->uclamp*
+ *
+ * p->state <- TASK_*:
+ *
+ *   is changed locklessly using set_current_state(), __set_current_state() or
+ *   set_special_state(), see their respective comments, or by
+ *   try_to_wake_up(). This latter uses p->pi_lock to serialize against
+ *   concurrent self.
+ *
+ * p->on_rq <- { 0, 1 = TASK_ON_RQ_QUEUED, 2 = TASK_ON_RQ_MIGRATING }:
+ *
+ *   is set by activate_task() and cleared by deactivate_task(), under
+ *   rq->lock. Non-zero indicates the task is runnable, the special
+ *   ON_RQ_MIGRATING state is used for migration without holding both
+ *   rq->locks. It indicates task_cpu() is not stable, see task_rq_lock().
+ *
+ * p->on_cpu <- { 0, 1 }:
+ *
+ *   is set by prepare_task() and cleared by finish_task() such that it will be
+ *   set before p is scheduled-in and cleared after p is scheduled-out, both
+ *   under rq->lock. Non-zero indicates the task is running on its CPU.
+ *
+ *   [ The astute reader will observe that it is possible for two tasks on one
+ *     CPU to have ->on_cpu = 1 at the same time. ]
+ *
+ * task_cpu(p): is changed by set_task_cpu(), the rules are:
+ *
+ *  - Don't call set_task_cpu() on a blocked task:
+ *
+ *    We don't care what CPU we're not running on, this simplifies hotplug,
+ *    the CPU assignment of blocked tasks isn't required to be valid.
+ *
+ *  - for try_to_wake_up(), called under p->pi_lock:
+ *
+ *    This allows try_to_wake_up() to only take one rq->lock, see its comment.
+ *
+ *  - for migration called under rq->lock:
+ *    [ see task_on_rq_migrating() in task_rq_lock() ]
+ *
+ *    o move_queued_task()
+ *    o detach_task()
+ *
+ *  - for migration called under double_rq_lock():
+ *
+ *    o __migrate_swap_task()
+ *    o push_rt_task() / pull_rt_task()
+ *    o push_dl_task() / pull_dl_task()
+ *    o dl_task_offline_migration()
+ *
+ */
+
 /*
  * __task_rq_lock - lock the rq @p resides on.
  */
@@ -218,6 +320,13 @@
 	update_rq_clock_task(rq, delta);
 }
 
+static inline void
+rq_csd_init(struct rq *rq, struct __call_single_data *csd, smp_call_func_t func)
+{
+	csd->flags = 0;
+	csd->func = func;
+	csd->info = rq;
+}
 
 #ifdef CONFIG_SCHED_HRTICK
 /*
@@ -269,7 +378,6 @@
 
 	rq_lock(rq, &rf);
 	__hrtick_restart(rq);
-	rq->hrtick_csd_pending = 0;
 	rq_unlock(rq, &rf);
 }
 
@@ -290,12 +398,10 @@
 	delta = max_t(s64, delay, 10000LL);
 	rq->hrtick_time = ktime_add_ns(timer->base->get_time(), delta);
 
-	if (rq == this_rq()) {
+	if (rq == this_rq())
 		__hrtick_restart(rq);
-	} else if (!rq->hrtick_csd_pending) {
+	else
 		smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd);
-		rq->hrtick_csd_pending = 1;
-	}
 }
 
 #else
@@ -314,18 +420,14 @@
 	hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay),
 		      HRTIMER_MODE_REL_PINNED_HARD);
 }
+
 #endif /* CONFIG_SMP */
 
 static void hrtick_rq_init(struct rq *rq)
 {
 #ifdef CONFIG_SMP
-	rq->hrtick_csd_pending = 0;
-
-	rq->hrtick_csd.flags = 0;
-	rq->hrtick_csd.func = __hrtick_start;
-	rq->hrtick_csd.info = rq;
+	rq_csd_init(rq, &rq->hrtick_csd, __hrtick_start);
 #endif
-
 	hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	rq->hrtick_timer.function = hrtick;
 }
@@ -549,27 +651,32 @@
  */
 int get_nohz_timer_target(void)
 {
-	int i, cpu = smp_processor_id();
+	int i, cpu = smp_processor_id(), default_cpu = -1;
 	struct sched_domain *sd;
 
-	if (!idle_cpu(cpu) && housekeeping_cpu(cpu, HK_FLAG_TIMER))
-		return cpu;
+	if (housekeeping_cpu(cpu, HK_FLAG_TIMER)) {
+		if (!idle_cpu(cpu))
+			return cpu;
+		default_cpu = cpu;
+	}
 
 	rcu_read_lock();
 	for_each_domain(cpu, sd) {
-		for_each_cpu(i, sched_domain_span(sd)) {
+		for_each_cpu_and(i, sched_domain_span(sd),
+			housekeeping_cpumask(HK_FLAG_TIMER)) {
 			if (cpu == i)
 				continue;
 
-			if (!idle_cpu(i) && housekeeping_cpu(i, HK_FLAG_TIMER)) {
+			if (!idle_cpu(i)) {
 				cpu = i;
 				goto unlock;
 			}
 		}
 	}
 
-	if (!housekeeping_cpu(cpu, HK_FLAG_TIMER))
-		cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
+	if (default_cpu == -1)
+		default_cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
+	cpu = default_cpu;
 unlock:
 	rcu_read_unlock();
 	return cpu;
@@ -629,29 +736,23 @@
 		wake_up_idle_cpu(cpu);
 }
 
-static inline bool got_nohz_idle_kick(void)
+static void nohz_csd_func(void *info)
 {
-	int cpu = smp_processor_id();
-
-	if (!(atomic_read(nohz_flags(cpu)) & NOHZ_KICK_MASK))
-		return false;
-
-	if (idle_cpu(cpu) && !need_resched())
-		return true;
+	struct rq *rq = info;
+	int cpu = cpu_of(rq);
+	unsigned int flags;
 
 	/*
-	 * We can't run Idle Load Balance on this CPU for this time so we
-	 * cancel it and clear NOHZ_BALANCE_KICK
+	 * Release the rq::nohz_csd.
 	 */
-	atomic_andnot(NOHZ_KICK_MASK, nohz_flags(cpu));
-	return false;
-}
+	flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(cpu));
+	WARN_ON(!(flags & NOHZ_KICK_MASK));
 
-#else /* CONFIG_NO_HZ_COMMON */
-
-static inline bool got_nohz_idle_kick(void)
-{
-	return false;
+	rq->idle_balance = idle_cpu(cpu);
+	if (rq->idle_balance && !need_resched()) {
+		rq->nohz_idle_balance = flags;
+		raise_softirq_irqoff(SCHED_SOFTIRQ);
+	}
 }
 
 #endif /* CONFIG_NO_HZ_COMMON */
@@ -753,7 +854,6 @@
 	if (task_has_idle_policy(p)) {
 		load->weight = scale_load(WEIGHT_IDLEPRIO);
 		load->inv_weight = WMULT_IDLEPRIO;
-		p->se.runnable_weight = load->weight;
 		return;
 	}
 
@@ -766,7 +866,6 @@
 	} else {
 		load->weight = scale_load(sched_prio_to_weight[prio]);
 		load->inv_weight = sched_prio_to_wmult[prio];
-		p->se.runnable_weight = load->weight;
 	}
 }
 
@@ -789,6 +888,23 @@
 /* Max allowed maximum utilization */
 unsigned int sysctl_sched_uclamp_util_max = SCHED_CAPACITY_SCALE;
 
+/*
+ * By default RT tasks run at the maximum performance point/capacity of the
+ * system. Uclamp enforces this by always setting UCLAMP_MIN of RT tasks to
+ * SCHED_CAPACITY_SCALE.
+ *
+ * This knob allows admins to change the default behavior when uclamp is being
+ * used. In battery powered devices, particularly, running at the maximum
+ * capacity and frequency will increase energy consumption and shorten the
+ * battery life.
+ *
+ * This knob only affects RT tasks that their uclamp_se->user_defined == false.
+ *
+ * This knob will not override the system default sched_util_clamp_min defined
+ * above.
+ */
+unsigned int sysctl_sched_uclamp_util_min_rt_default = SCHED_CAPACITY_SCALE;
+
 /* All clamps are required to be less or equal than these values */
 static struct uclamp_se uclamp_default[UCLAMP_CNT];
 
@@ -823,11 +939,6 @@
 	return min_t(unsigned int, clamp_value / UCLAMP_BUCKET_DELTA, UCLAMP_BUCKETS - 1);
 }
 
-static inline unsigned int uclamp_bucket_base_value(unsigned int clamp_value)
-{
-	return UCLAMP_BUCKET_DELTA * uclamp_bucket_id(clamp_value);
-}
-
 static inline unsigned int uclamp_none(enum uclamp_id clamp_id)
 {
 	if (clamp_id == UCLAMP_MIN)
@@ -891,6 +1002,64 @@
 	return uclamp_idle_value(rq, clamp_id, clamp_value);
 }
 
+static void __uclamp_update_util_min_rt_default(struct task_struct *p)
+{
+	unsigned int default_util_min;
+	struct uclamp_se *uc_se;
+
+	lockdep_assert_held(&p->pi_lock);
+
+	uc_se = &p->uclamp_req[UCLAMP_MIN];
+
+	/* Only sync if user didn't override the default */
+	if (uc_se->user_defined)
+		return;
+
+	default_util_min = sysctl_sched_uclamp_util_min_rt_default;
+	uclamp_se_set(uc_se, default_util_min, false);
+}
+
+static void uclamp_update_util_min_rt_default(struct task_struct *p)
+{
+	struct rq_flags rf;
+	struct rq *rq;
+
+	if (!rt_task(p))
+		return;
+
+	/* Protect updates to p->uclamp_* */
+	rq = task_rq_lock(p, &rf);
+	__uclamp_update_util_min_rt_default(p);
+	task_rq_unlock(rq, p, &rf);
+}
+
+static void uclamp_sync_util_min_rt_default(void)
+{
+	struct task_struct *g, *p;
+
+	/*
+	 * copy_process()			sysctl_uclamp
+	 *					  uclamp_min_rt = X;
+	 *   write_lock(&tasklist_lock)		  read_lock(&tasklist_lock)
+	 *   // link thread			  smp_mb__after_spinlock()
+	 *   write_unlock(&tasklist_lock)	  read_unlock(&tasklist_lock);
+	 *   sched_post_fork()			  for_each_process_thread()
+	 *     __uclamp_sync_rt()		    __uclamp_sync_rt()
+	 *
+	 * Ensures that either sched_post_fork() will observe the new
+	 * uclamp_min_rt or for_each_process_thread() will observe the new
+	 * task.
+	 */
+	read_lock(&tasklist_lock);
+	smp_mb__after_spinlock();
+	read_unlock(&tasklist_lock);
+
+	rcu_read_lock();
+	for_each_process_thread(g, p)
+		uclamp_update_util_min_rt_default(p);
+	rcu_read_unlock();
+}
+
 static inline struct uclamp_se
 uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id)
 {
@@ -939,17 +1108,17 @@
 	return uc_req;
 }
 
-unsigned int uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id)
+unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id)
 {
 	struct uclamp_se uc_eff;
 
 	/* Task currently refcounted: use back-annotated (effective) value */
 	if (p->uclamp[clamp_id].active)
-		return p->uclamp[clamp_id].value;
+		return (unsigned long)p->uclamp[clamp_id].value;
 
 	uc_eff = uclamp_eff_get(p, clamp_id);
 
-	return uc_eff.value;
+	return (unsigned long)uc_eff.value;
 }
 
 /*
@@ -1188,16 +1357,16 @@
 #endif
 
 int sysctl_sched_uclamp_handler(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	bool update_root_tg = false;
-	int old_min, old_max;
+	int old_min, old_max, old_min_rt;
 	int result;
 
 	mutex_lock(&uclamp_mutex);
 	old_min = sysctl_sched_uclamp_util_min;
 	old_max = sysctl_sched_uclamp_util_max;
+	old_min_rt = sysctl_sched_uclamp_util_min_rt_default;
 
 	result = proc_dointvec(table, write, buffer, lenp, ppos);
 	if (result)
@@ -1206,7 +1375,9 @@
 		goto done;
 
 	if (sysctl_sched_uclamp_util_min > sysctl_sched_uclamp_util_max ||
-	    sysctl_sched_uclamp_util_max > SCHED_CAPACITY_SCALE) {
+	    sysctl_sched_uclamp_util_max > SCHED_CAPACITY_SCALE	||
+	    sysctl_sched_uclamp_util_min_rt_default > SCHED_CAPACITY_SCALE) {
+
 		result = -EINVAL;
 		goto undo;
 	}
@@ -1227,6 +1398,11 @@
 		uclamp_update_root_tg();
 	}
 
+	if (old_min_rt != sysctl_sched_uclamp_util_min_rt_default) {
+		static_branch_enable(&sched_uclamp_used);
+		uclamp_sync_util_min_rt_default();
+	}
+
 	/*
 	 * We update all RUNNABLE tasks only when task groups are in use.
 	 * Otherwise, keep it simple and do just a lazy update at each next
@@ -1238,6 +1414,7 @@
 undo:
 	sysctl_sched_uclamp_util_min = old_min;
 	sysctl_sched_uclamp_util_max = old_max;
+	sysctl_sched_uclamp_util_min_rt_default = old_min_rt;
 done:
 	mutex_unlock(&uclamp_mutex);
 
@@ -1283,17 +1460,20 @@
 	 */
 	for_each_clamp_id(clamp_id) {
 		struct uclamp_se *uc_se = &p->uclamp_req[clamp_id];
-		unsigned int clamp_value = uclamp_none(clamp_id);
 
 		/* Keep using defined clamps across class changes */
 		if (uc_se->user_defined)
 			continue;
 
-		/* By default, RT tasks always get 100% boost */
+		/*
+		 * RT by default have a 100% boost value that could be modified
+		 * at runtime.
+		 */
 		if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN))
-			clamp_value = uclamp_none(UCLAMP_MAX);
+			__uclamp_update_util_min_rt_default(p);
+		else
+			uclamp_se_set(uc_se, uclamp_none(clamp_id), false);
 
-		uclamp_se_set(uc_se, clamp_value, false);
 	}
 
 	if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP)))
@@ -1314,6 +1494,10 @@
 {
 	enum uclamp_id clamp_id;
 
+	/*
+	 * We don't need to hold task_rq_lock() when updating p->uclamp_* here
+	 * as the task is still at its early fork stages.
+	 */
 	for_each_clamp_id(clamp_id)
 		p->uclamp[clamp_id].active = false;
 
@@ -1326,6 +1510,11 @@
 	}
 }
 
+static void uclamp_post_fork(struct task_struct *p)
+{
+	uclamp_update_util_min_rt_default(p);
+}
+
 static void __init init_uclamp_rq(struct rq *rq)
 {
 	enum uclamp_id clamp_id;
@@ -1337,7 +1526,7 @@
 		};
 	}
 
-	rq->uclamp_flags = 0;
+	rq->uclamp_flags = UCLAMP_FLAG_IDLE;
 }
 
 static void __init init_uclamp(void)
@@ -1346,8 +1535,6 @@
 	enum uclamp_id clamp_id;
 	int cpu;
 
-	mutex_init(&uclamp_mutex);
-
 	for_each_possible_cpu(cpu)
 		init_uclamp_rq(cpu_rq(cpu));
 
@@ -1378,6 +1565,7 @@
 static void __setscheduler_uclamp(struct task_struct *p,
 				  const struct sched_attr *attr) { }
 static inline void uclamp_fork(struct task_struct *p) { }
+static inline void uclamp_post_fork(struct task_struct *p) { }
 static inline void init_uclamp(void) { }
 #endif /* CONFIG_UCLAMP_TASK */
 
@@ -1411,9 +1599,6 @@
 
 void activate_task(struct rq *rq, struct task_struct *p, int flags)
 {
-	if (task_contributes_to_load(p))
-		rq->nr_uninterruptible--;
-
 	enqueue_task(rq, p, flags);
 
 	p->on_rq = TASK_ON_RQ_QUEUED;
@@ -1423,18 +1608,21 @@
 {
 	p->on_rq = (flags & DEQUEUE_SLEEP) ? 0 : TASK_ON_RQ_MIGRATING;
 
-	if (task_contributes_to_load(p))
-		rq->nr_uninterruptible++;
-
 	dequeue_task(rq, p, flags);
 }
 
-/*
- * __normal_prio - return the priority that is based on the static prio
- */
-static inline int __normal_prio(struct task_struct *p)
+static inline int __normal_prio(int policy, int rt_prio, int nice)
 {
-	return p->static_prio;
+	int prio;
+
+	if (dl_policy(policy))
+		prio = MAX_DL_PRIO - 1;
+	else if (rt_policy(policy))
+		prio = MAX_RT_PRIO - 1 - rt_prio;
+	else
+		prio = NICE_TO_PRIO(nice);
+
+	return prio;
 }
 
 /*
@@ -1446,15 +1634,7 @@
  */
 static inline int normal_prio(struct task_struct *p)
 {
-	int prio;
-
-	if (task_has_dl_policy(p))
-		prio = MAX_DL_PRIO-1;
-	else if (task_has_rt_policy(p))
-		prio = MAX_RT_PRIO-1 - p->rt_priority;
-	else
-		prio = __normal_prio(p);
-	return prio;
+	return __normal_prio(p->policy, p->rt_priority, PRIO_TO_NICE(p->static_prio));
 }
 
 /*
@@ -1510,20 +1690,10 @@
 
 void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
 {
-	const struct sched_class *class;
-
-	if (p->sched_class == rq->curr->sched_class) {
+	if (p->sched_class == rq->curr->sched_class)
 		rq->curr->sched_class->check_preempt_curr(rq, p, flags);
-	} else {
-		for_each_class(class) {
-			if (class == rq->curr->sched_class)
-				break;
-			if (class == p->sched_class) {
-				resched_curr(rq);
-				break;
-			}
-		}
-	}
+	else if (p->sched_class > rq->curr->sched_class)
+		resched_curr(rq);
 
 	/*
 	 * A queue event has occurred, and we're going to schedule.  In
@@ -1535,17 +1705,6 @@
 
 #ifdef CONFIG_SMP
 
-static inline bool is_per_cpu_kthread(struct task_struct *p)
-{
-	if (!(p->flags & PF_KTHREAD))
-		return false;
-
-	if (p->nr_cpus_allowed != 1)
-		return false;
-
-	return true;
-}
-
 /*
  * Per-CPU kthreads are allowed to run on !active && online CPUs, see
  * __set_cpus_allowed_ptr() and select_fallback_rq().
@@ -1585,8 +1744,7 @@
 {
 	lockdep_assert_held(&rq->lock);
 
-	WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING);
-	dequeue_task(rq, p, DEQUEUE_NOCLOCK);
+	deactivate_task(rq, p, DEQUEUE_NOCLOCK);
 	set_task_cpu(p, new_cpu);
 	rq_unlock(rq, rf);
 
@@ -1594,8 +1752,7 @@
 
 	rq_lock(rq, rf);
 	BUG_ON(task_cpu(p) != new_cpu);
-	enqueue_task(rq, p, 0);
-	p->on_rq = TASK_ON_RQ_QUEUED;
+	activate_task(rq, p, 0);
 	check_preempt_curr(rq, p, 0);
 
 	return rq;
@@ -1650,7 +1807,7 @@
 	 * __migrate_task() such that we will not miss enforcing cpus_ptr
 	 * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test.
 	 */
-	sched_ttwu_pending();
+	flush_smp_call_function_from_idle();
 
 	raw_spin_lock(&p->pi_lock);
 	rq_lock(rq, &rf);
@@ -1751,7 +1908,12 @@
 	if (cpumask_equal(&p->cpus_mask, new_mask))
 		goto out;
 
-	dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);
+	/*
+	 * Picking a ~random cpu helps in cases where we are changing affinity
+	 * for groups of tasks (ie. cpuset), so that load balancing is not
+	 * immediately required to distribute the tasks within their new mask.
+	 */
+	dest_cpu = cpumask_any_and_distribute(cpu_valid_mask, new_mask);
 	if (dest_cpu >= nr_cpu_ids) {
 		ret = -EINVAL;
 		goto out;
@@ -2163,7 +2325,7 @@
 				state = possible;
 				break;
 			}
-			/* Fall-through */
+			fallthrough;
 		case possible:
 			do_set_cpus_allowed(p, cpu_possible_mask);
 			state = fail;
@@ -2220,12 +2382,6 @@
 	return cpu;
 }
 
-static void update_avg(u64 *avg, u64 sample)
-{
-	s64 diff = sample - *avg;
-	*avg += diff >> 3;
-}
-
 void sched_set_stop_task(int cpu, struct task_struct *stop)
 {
 	struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
@@ -2348,25 +2504,49 @@
 
 	lockdep_assert_held(&rq->lock);
 
-#ifdef CONFIG_SMP
 	if (p->sched_contributes_to_load)
 		rq->nr_uninterruptible--;
 
+#ifdef CONFIG_SMP
 	if (wake_flags & WF_MIGRATED)
 		en_flags |= ENQUEUE_MIGRATED;
+	else
 #endif
+	if (p->in_iowait) {
+		delayacct_blkio_end(p);
+		atomic_dec(&task_rq(p)->nr_iowait);
+	}
 
 	activate_task(rq, p, en_flags);
 	ttwu_do_wakeup(rq, p, wake_flags, rf);
 }
 
 /*
- * Called in case the task @p isn't fully descheduled from its runqueue,
- * in this case we must do a remote wakeup. Its a 'light' wakeup though,
- * since all we need to do is flip p->state to TASK_RUNNING, since
- * the task is still ->on_rq.
+ * Consider @p being inside a wait loop:
+ *
+ *   for (;;) {
+ *      set_current_state(TASK_UNINTERRUPTIBLE);
+ *
+ *      if (CONDITION)
+ *         break;
+ *
+ *      schedule();
+ *   }
+ *   __set_current_state(TASK_RUNNING);
+ *
+ * between set_current_state() and schedule(). In this case @p is still
+ * runnable, so all that needs doing is change p->state back to TASK_RUNNING in
+ * an atomic manner.
+ *
+ * By taking task_rq(p)->lock we serialize against schedule(), if @p->on_rq
+ * then schedule() must still happen and p->state can be changed to
+ * TASK_RUNNING. Otherwise we lost the race, schedule() has happened, and we
+ * need to do a full wakeup with enqueue.
+ *
+ * Returns: %true when the wakeup is done,
+ *          %false otherwise.
  */
-static int ttwu_remote(struct task_struct *p, int wake_flags)
+static int ttwu_runnable(struct task_struct *p, int wake_flags)
 {
 	struct rq_flags rf;
 	struct rq *rq;
@@ -2385,75 +2565,63 @@
 }
 
 #ifdef CONFIG_SMP
-void sched_ttwu_pending(void)
+void sched_ttwu_pending(void *arg)
 {
+	struct llist_node *llist = arg;
 	struct rq *rq = this_rq();
-	struct llist_node *llist = llist_del_all(&rq->wake_list);
 	struct task_struct *p, *t;
 	struct rq_flags rf;
 
 	if (!llist)
 		return;
 
+	/*
+	 * rq::ttwu_pending racy indication of out-standing wakeups.
+	 * Races such that false-negatives are possible, since they
+	 * are shorter lived that false-positives would be.
+	 */
+	WRITE_ONCE(rq->ttwu_pending, 0);
+
 	rq_lock_irqsave(rq, &rf);
 	update_rq_clock(rq);
 
-	llist_for_each_entry_safe(p, t, llist, wake_entry)
+	llist_for_each_entry_safe(p, t, llist, wake_entry.llist) {
+		if (WARN_ON_ONCE(p->on_cpu))
+			smp_cond_load_acquire(&p->on_cpu, !VAL);
+
+		if (WARN_ON_ONCE(task_cpu(p) != cpu_of(rq)))
+			set_task_cpu(p, cpu_of(rq));
+
 		ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0, &rf);
+	}
 
 	rq_unlock_irqrestore(rq, &rf);
 }
 
-void scheduler_ipi(void)
+void send_call_function_single_ipi(int cpu)
 {
-	/*
-	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
-	 * TIF_NEED_RESCHED remotely (for the first time) will also send
-	 * this IPI.
-	 */
-	preempt_fold_need_resched();
+	struct rq *rq = cpu_rq(cpu);
 
-	if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick())
-		return;
-
-	/*
-	 * Not all reschedule IPI handlers call irq_enter/irq_exit, since
-	 * traditionally all their work was done from the interrupt return
-	 * path. Now that we actually do some work, we need to make sure
-	 * we do call them.
-	 *
-	 * Some archs already do call them, luckily irq_enter/exit nest
-	 * properly.
-	 *
-	 * Arguably we should visit all archs and update all handlers,
-	 * however a fair share of IPIs are still resched only so this would
-	 * somewhat pessimize the simple resched case.
-	 */
-	irq_enter();
-	sched_ttwu_pending();
-
-	/*
-	 * Check if someone kicked us for doing the nohz idle load balance.
-	 */
-	if (unlikely(got_nohz_idle_kick())) {
-		this_rq()->idle_balance = 1;
-		raise_softirq_irqoff(SCHED_SOFTIRQ);
-	}
-	irq_exit();
+	if (!set_nr_if_polling(rq->idle))
+		arch_send_call_function_single_ipi(cpu);
+	else
+		trace_sched_wake_idle_without_ipi(cpu);
 }
 
-static void ttwu_queue_remote(struct task_struct *p, int cpu, int wake_flags)
+/*
+ * Queue a task on the target CPUs wake_list and wake the CPU via IPI if
+ * necessary. The wakee CPU on receipt of the IPI will queue the task
+ * via sched_ttwu_wakeup() for activation so the wakee incurs the cost
+ * of the wakeup instead of the waker.
+ */
+static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags)
 {
 	struct rq *rq = cpu_rq(cpu);
 
 	p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED);
 
-	if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) {
-		if (!set_nr_if_polling(rq->idle))
-			smp_send_reschedule(cpu);
-		else
-			trace_sched_wake_idle_without_ipi(cpu);
-	}
+	WRITE_ONCE(rq->ttwu_pending, 1);
+	__smp_call_single_queue(cpu, &p->wake_entry.llist);
 }
 
 void wake_up_if_idle(int cpu)
@@ -2482,8 +2650,54 @@
 
 bool cpus_share_cache(int this_cpu, int that_cpu)
 {
+	if (this_cpu == that_cpu)
+		return true;
+
 	return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu);
 }
+
+static inline bool ttwu_queue_cond(int cpu, int wake_flags)
+{
+	/*
+	 * If the CPU does not share cache, then queue the task on the
+	 * remote rqs wakelist to avoid accessing remote data.
+	 */
+	if (!cpus_share_cache(smp_processor_id(), cpu))
+		return true;
+
+	/*
+	 * If the task is descheduling and the only running task on the
+	 * CPU then use the wakelist to offload the task activation to
+	 * the soon-to-be-idle CPU as the current CPU is likely busy.
+	 * nr_running is checked to avoid unnecessary task stacking.
+	 */
+	if ((wake_flags & WF_ON_CPU) && cpu_rq(cpu)->nr_running <= 1)
+		return true;
+
+	return false;
+}
+
+static bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags)
+{
+	if (sched_feat(TTWU_QUEUE) && ttwu_queue_cond(cpu, wake_flags)) {
+		if (WARN_ON_ONCE(cpu == smp_processor_id()))
+			return false;
+
+		sched_clock_cpu(cpu); /* Sync clocks across CPUs */
+		__ttwu_queue_wakelist(p, cpu, wake_flags);
+		return true;
+	}
+
+	return false;
+}
+
+#else /* !CONFIG_SMP */
+
+static inline bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags)
+{
+	return false;
+}
+
 #endif /* CONFIG_SMP */
 
 static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags)
@@ -2491,13 +2705,8 @@
 	struct rq *rq = cpu_rq(cpu);
 	struct rq_flags rf;
 
-#if defined(CONFIG_SMP)
-	if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) {
-		sched_clock_cpu(cpu); /* Sync clocks across CPUs */
-		ttwu_queue_remote(p, cpu, wake_flags);
+	if (ttwu_queue_wakelist(p, cpu, wake_flags))
 		return;
-	}
-#endif
 
 	rq_lock(rq, &rf);
 	update_rq_clock(rq);
@@ -2553,8 +2762,8 @@
  * migration. However the means are completely different as there is no lock
  * chain to provide order. Instead we do:
  *
- *   1) smp_store_release(X->on_cpu, 0)
- *   2) smp_cond_load_acquire(!X->on_cpu)
+ *   1) smp_store_release(X->on_cpu, 0)   -- finish_task()
+ *   2) smp_cond_load_acquire(!X->on_cpu) -- try_to_wake_up()
  *
  * Example:
  *
@@ -2594,15 +2803,33 @@
  * @state: the mask of task states that can be woken
  * @wake_flags: wake modifier flags (WF_*)
  *
- * If (@state & @p->state) @p->state = TASK_RUNNING.
+ * Conceptually does:
+ *
+ *   If (@state & @p->state) @p->state = TASK_RUNNING.
  *
  * If the task was not queued/runnable, also place it back on a runqueue.
  *
- * Atomic against schedule() which would dequeue a task, also see
- * set_current_state().
+ * This function is atomic against schedule() which would dequeue the task.
  *
- * This function executes a full memory barrier before accessing the task
- * state; see set_current_state().
+ * It issues a full memory barrier before accessing @p->state, see the comment
+ * with set_current_state().
+ *
+ * Uses p->pi_lock to serialize against concurrent wake-ups.
+ *
+ * Relies on p->pi_lock stabilizing:
+ *  - p->sched_class
+ *  - p->cpus_ptr
+ *  - p->sched_task_group
+ * in order to do migration, see its use of select_task_rq()/set_task_cpu().
+ *
+ * Tries really hard to only take one task_rq(p)->lock for performance.
+ * Takes rq->lock in:
+ *  - ttwu_runnable()    -- old rq, unavoidable, see comment there;
+ *  - ttwu_queue()       -- new rq, for enqueue of the task;
+ *  - psi_ttwu_dequeue() -- much sadness :-( accounting will kill us.
+ *
+ * As a consequence we race really badly with just about everything. See the
+ * many memory barriers and their comments for details.
  *
  * Return: %true if @p->state changes (an actual wakeup was done),
  *	   %false otherwise.
@@ -2618,7 +2845,7 @@
 		/*
 		 * We're waking current, this means 'p->on_rq' and 'task_cpu(p)
 		 * == smp_processor_id()'. Together this means we can special
-		 * case the whole 'p->on_rq && ttwu_remote()' case below
+		 * case the whole 'p->on_rq && ttwu_runnable()' case below
 		 * without taking any locks.
 		 *
 		 * In particular:
@@ -2630,7 +2857,6 @@
 			goto out;
 
 		success = 1;
-		cpu = task_cpu(p);
 		trace_sched_waking(p);
 		p->state = TASK_RUNNING;
 		trace_sched_wakeup(p);
@@ -2640,8 +2866,8 @@
 	/*
 	 * If we are going to wake up a thread waiting for CONDITION we
 	 * need to ensure that CONDITION=1 done by the caller can not be
-	 * reordered with p->state check below. This pairs with mb() in
-	 * set_current_state() the waiting thread does.
+	 * reordered with p->state check below. This pairs with smp_store_mb()
+	 * in set_current_state() that the waiting thread does.
 	 */
 	raw_spin_lock_irqsave(&p->pi_lock, flags);
 	smp_mb__after_spinlock();
@@ -2652,7 +2878,6 @@
 
 	/* We're going to change ->state: */
 	success = 1;
-	cpu = task_cpu(p);
 
 	/*
 	 * Ensure we load p->on_rq _after_ p->state, otherwise it would
@@ -2673,9 +2898,11 @@
 	 *
 	 * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in
 	 * __schedule().  See the comment for smp_mb__after_spinlock().
+	 *
+	 * A similar smb_rmb() lives in try_invoke_on_locked_down_task().
 	 */
 	smp_rmb();
-	if (p->on_rq && ttwu_remote(p, wake_flags))
+	if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags))
 		goto unlock;
 
 #ifdef CONFIG_SMP
@@ -2697,8 +2924,43 @@
 	 *
 	 * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in
 	 * __schedule().  See the comment for smp_mb__after_spinlock().
+	 *
+	 * Form a control-dep-acquire with p->on_rq == 0 above, to ensure
+	 * schedule()'s deactivate_task() has 'happened' and p will no longer
+	 * care about it's own p->state. See the comment in __schedule().
 	 */
-	smp_rmb();
+	smp_acquire__after_ctrl_dep();
+
+	/*
+	 * We're doing the wakeup (@success == 1), they did a dequeue (p->on_rq
+	 * == 0), which means we need to do an enqueue, change p->state to
+	 * TASK_WAKING such that we can unlock p->pi_lock before doing the
+	 * enqueue, such as ttwu_queue_wakelist().
+	 */
+	p->state = TASK_WAKING;
+
+	/*
+	 * If the owning (remote) CPU is still in the middle of schedule() with
+	 * this task as prev, considering queueing p on the remote CPUs wake_list
+	 * which potentially sends an IPI instead of spinning on p->on_cpu to
+	 * let the waker make forward progress. This is safe because IRQs are
+	 * disabled and the IPI will deliver after on_cpu is cleared.
+	 *
+	 * Ensure we load task_cpu(p) after p->on_cpu:
+	 *
+	 * set_task_cpu(p, cpu);
+	 *   STORE p->cpu = @cpu
+	 * __schedule() (switch to task 'p')
+	 *   LOCK rq->lock
+	 *   smp_mb__after_spin_lock()		smp_cond_load_acquire(&p->on_cpu)
+	 *   STORE p->on_cpu = 1		LOAD p->cpu
+	 *
+	 * to ensure we observe the correct CPU on which the task is currently
+	 * scheduling.
+	 */
+	if (smp_load_acquire(&p->on_cpu) &&
+	    ttwu_queue_wakelist(p, task_cpu(p), wake_flags | WF_ON_CPU))
+		goto unlock;
 
 	/*
 	 * If the owning (remote) CPU is still in the middle of schedule() with
@@ -2711,28 +2973,19 @@
 	 */
 	smp_cond_load_acquire(&p->on_cpu, !VAL);
 
-	p->sched_contributes_to_load = !!task_contributes_to_load(p);
-	p->state = TASK_WAKING;
-
-	if (p->in_iowait) {
-		delayacct_blkio_end(p);
-		atomic_dec(&task_rq(p)->nr_iowait);
-	}
-
 	cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags);
 	if (task_cpu(p) != cpu) {
+		if (p->in_iowait) {
+			delayacct_blkio_end(p);
+			atomic_dec(&task_rq(p)->nr_iowait);
+		}
+
 		wake_flags |= WF_MIGRATED;
 		psi_ttwu_dequeue(p);
 		set_task_cpu(p, cpu);
 	}
-
-#else /* CONFIG_SMP */
-
-	if (p->in_iowait) {
-		delayacct_blkio_end(p);
-		atomic_dec(&task_rq(p)->nr_iowait);
-	}
-
+#else
+	cpu = task_cpu(p);
 #endif /* CONFIG_SMP */
 
 	ttwu_queue(p, cpu, wake_flags);
@@ -2740,13 +2993,58 @@
 	raw_spin_unlock_irqrestore(&p->pi_lock, flags);
 out:
 	if (success)
-		ttwu_stat(p, cpu, wake_flags);
+		ttwu_stat(p, task_cpu(p), wake_flags);
 	preempt_enable();
 
 	return success;
 }
 
 /**
+ * try_invoke_on_locked_down_task - Invoke a function on task in fixed state
+ * @p: Process for which the function is to be invoked, can be @current.
+ * @func: Function to invoke.
+ * @arg: Argument to function.
+ *
+ * If the specified task can be quickly locked into a definite state
+ * (either sleeping or on a given runqueue), arrange to keep it in that
+ * state while invoking @func(@arg).  This function can use ->on_rq and
+ * task_curr() to work out what the state is, if required.  Given that
+ * @func can be invoked with a runqueue lock held, it had better be quite
+ * lightweight.
+ *
+ * Returns:
+ *	@false if the task slipped out from under the locks.
+ *	@true if the task was locked onto a runqueue or is sleeping.
+ *		However, @func can override this by returning @false.
+ */
+bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg)
+{
+	struct rq_flags rf;
+	bool ret = false;
+	struct rq *rq;
+
+	raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
+	if (p->on_rq) {
+		rq = __task_rq_lock(p, &rf);
+		if (task_rq(p) == rq)
+			ret = func(p, arg);
+		rq_unlock(rq, &rf);
+	} else {
+		switch (p->state) {
+		case TASK_RUNNING:
+		case TASK_WAKING:
+			break;
+		default:
+			smp_rmb(); // See smp_rmb() comment in try_to_wake_up().
+			if (!p->on_rq)
+				ret = func(p, arg);
+		}
+	}
+	raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags);
+	return ret;
+}
+
+/**
  * wake_up_process - Wake up a specific process
  * @p: The process to be woken up.
  *
@@ -2814,6 +3112,9 @@
 	p->capture_control = NULL;
 #endif
 	init_numa_balancing(clone_flags, p);
+#ifdef CONFIG_SMP
+	p->wake_entry.u_flags = CSD_TYPE_TTWU;
+#endif
 }
 
 DEFINE_STATIC_KEY_FALSE(sched_numa_balancing);
@@ -2830,7 +3131,7 @@
 
 #ifdef CONFIG_PROC_SYSCTL
 int sysctl_numa_balancing(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	int err;
@@ -2904,8 +3205,8 @@
 }
 
 #ifdef CONFIG_PROC_SYSCTL
-int sysctl_schedstats(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+int sysctl_schedstats(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	int err;
@@ -2933,8 +3234,6 @@
  */
 int sched_fork(unsigned long clone_flags, struct task_struct *p)
 {
-	unsigned long flags;
-
 	__sched_fork(clone_flags, p);
 	/*
 	 * We mark the process as NEW here. This guarantees that
@@ -2961,7 +3260,7 @@
 		} else if (PRIO_TO_NICE(p->static_prio) < 0)
 			p->static_prio = NICE_TO_PRIO(0);
 
-		p->prio = p->normal_prio = __normal_prio(p);
+		p->prio = p->normal_prio = p->static_prio;
 		set_load_weight(p, false);
 
 		/*
@@ -2980,24 +3279,6 @@
 
 	init_entity_runnable_average(&p->se);
 
-	/*
-	 * The child is not yet in the pid-hash so no cgroup attach races,
-	 * and the cgroup is pinned to this child due to cgroup_fork()
-	 * is ran before sched_fork().
-	 *
-	 * Silence PROVE_RCU.
-	 */
-	raw_spin_lock_irqsave(&p->pi_lock, flags);
-	rseq_migrate(p);
-	/*
-	 * We're setting the CPU for the first time, we don't migrate,
-	 * so use __set_task_cpu().
-	 */
-	__set_task_cpu(p, smp_processor_id());
-	if (p->sched_class->task_fork)
-		p->sched_class->task_fork(p);
-	raw_spin_unlock_irqrestore(&p->pi_lock, flags);
-
 #ifdef CONFIG_SCHED_INFO
 	if (likely(sched_info_on()))
 		memset(&p->sched_info, 0, sizeof(p->sched_info));
@@ -3013,6 +3294,32 @@
 	return 0;
 }
 
+void sched_post_fork(struct task_struct *p, struct kernel_clone_args *kargs)
+{
+	unsigned long flags;
+#ifdef CONFIG_CGROUP_SCHED
+	struct task_group *tg;
+#endif
+
+	raw_spin_lock_irqsave(&p->pi_lock, flags);
+#ifdef CONFIG_CGROUP_SCHED
+	tg = container_of(kargs->cset->subsys[cpu_cgrp_id],
+			  struct task_group, css);
+	p->sched_task_group = autogroup_task_group(p, tg);
+#endif
+	rseq_migrate(p);
+	/*
+	 * We're setting the CPU for the first time, we don't migrate,
+	 * so use __set_task_cpu().
+	 */
+	__set_task_cpu(p, smp_processor_id());
+	if (p->sched_class->task_fork)
+		p->sched_class->task_fork(p);
+	raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+
+	uclamp_post_fork(p);
+}
+
 unsigned long to_ratio(u64 period, u64 runtime)
 {
 	if (runtime == RUNTIME_INF)
@@ -3170,8 +3477,10 @@
 	/*
 	 * Claim the task as running, we do this before switching to it
 	 * such that any running task will have this set.
+	 *
+	 * See the ttwu() WF_ON_CPU case and its ordering comment.
 	 */
-	next->on_cpu = 1;
+	WRITE_ONCE(next->on_cpu, 1);
 #endif
 }
 
@@ -3179,8 +3488,9 @@
 {
 #ifdef CONFIG_SMP
 	/*
-	 * After ->on_cpu is cleared, the task can be moved to a different CPU.
-	 * We must ensure this doesn't happen until the switch is completely
+	 * This must be the very last reference to @prev from this CPU. After
+	 * p->on_cpu is cleared, the task can be moved to a different CPU. We
+	 * must ensure this doesn't happen until the switch is completely
 	 * finished.
 	 *
 	 * In particular, the load of prev->state in finish_task_switch() must
@@ -3202,7 +3512,7 @@
 	 * do an early lockdep release here:
 	 */
 	rq_unpin_lock(rq, rf);
-	spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
+	spin_release(&rq->lock.dep_map, _THIS_IP_);
 #ifdef CONFIG_DEBUG_SPINLOCK
 	/* this is a valid case when another task releases the spinlock */
 	rq->lock.owner = next;
@@ -3689,12 +3999,16 @@
 	struct rq *rq = cpu_rq(cpu);
 	struct task_struct *curr = rq->curr;
 	struct rq_flags rf;
+	unsigned long thermal_pressure;
 
+	arch_scale_freq_tick();
 	sched_clock_tick();
 
 	rq_lock(rq, &rf);
 
 	update_rq_clock(rq);
+	thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
+	update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure);
 	curr->sched_class->task_tick(rq, curr, 0);
 	calc_global_load_tick(rq);
 	psi_task_tick(rq);
@@ -3958,8 +4272,7 @@
 	if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)
 	    && in_atomic_preempt_off()) {
 		pr_err("Preemption disabled at:");
-		print_ip_sym(preempt_disable_ip);
-		pr_cont("\n");
+		print_ip_sym(KERN_ERR, preempt_disable_ip);
 	}
 	if (panic_on_warn)
 		panic("scheduling while atomic\n");
@@ -3976,6 +4289,9 @@
 #ifdef CONFIG_SCHED_STACK_END_CHECK
 	if (task_stack_end_corrupted(prev))
 		panic("corrupted stack end detected inside scheduler\n");
+
+	if (task_scs_end_corrupted(prev))
+		panic("corrupted shadow stack detected inside scheduler\n");
 #endif
 
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
@@ -3998,6 +4314,28 @@
 	schedstat_inc(this_rq()->sched_count);
 }
 
+static void put_prev_task_balance(struct rq *rq, struct task_struct *prev,
+				  struct rq_flags *rf)
+{
+#ifdef CONFIG_SMP
+	const struct sched_class *class;
+	/*
+	 * We must do the balancing pass before put_prev_task(), such
+	 * that when we release the rq->lock the task is in the same
+	 * state as before we took rq->lock.
+	 *
+	 * We can terminate the balance pass as soon as we know there is
+	 * a runnable task of @class priority or higher.
+	 */
+	for_class_range(class, prev->sched_class, &idle_sched_class) {
+		if (class->balance(rq, prev, rf))
+			break;
+	}
+#endif
+
+	put_prev_task(rq, prev);
+}
+
 /*
  * Pick up the highest-prio task:
  */
@@ -4013,41 +4351,27 @@
 	 * higher scheduling class, because otherwise those loose the
 	 * opportunity to pull in more work from other CPUs.
 	 */
-	if (likely((prev->sched_class == &idle_sched_class ||
-		    prev->sched_class == &fair_sched_class) &&
+	if (likely(prev->sched_class <= &fair_sched_class &&
 		   rq->nr_running == rq->cfs.h_nr_running)) {
 
-		p = fair_sched_class.pick_next_task(rq, prev, rf);
+		p = pick_next_task_fair(rq, prev, rf);
 		if (unlikely(p == RETRY_TASK))
 			goto restart;
 
 		/* Assumes fair_sched_class->next == idle_sched_class */
-		if (unlikely(!p))
-			p = idle_sched_class.pick_next_task(rq, prev, rf);
+		if (!p) {
+			put_prev_task(rq, prev);
+			p = pick_next_task_idle(rq);
+		}
 
 		return p;
 	}
 
 restart:
-#ifdef CONFIG_SMP
-	/*
-	 * We must do the balancing pass before put_next_task(), such
-	 * that when we release the rq->lock the task is in the same
-	 * state as before we took rq->lock.
-	 *
-	 * We can terminate the balance pass as soon as we know there is
-	 * a runnable task of @class priority or higher.
-	 */
-	for_class_range(class, prev->sched_class, &idle_sched_class) {
-		if (class->balance(rq, prev, rf))
-			break;
-	}
-#endif
-
-	put_prev_task(rq, prev);
+	put_prev_task_balance(rq, prev, rf);
 
 	for_each_class(class) {
-		p = class->pick_next_task(rq, NULL, NULL);
+		p = class->pick_next_task(rq);
 		if (p)
 			return p;
 	}
@@ -4099,6 +4423,7 @@
 {
 	struct task_struct *prev, *next;
 	unsigned long *switch_count;
+	unsigned long prev_state;
 	struct rq_flags rf;
 	struct rq *rq;
 	int cpu;
@@ -4118,9 +4443,16 @@
 	/*
 	 * Make sure that signal_pending_state()->signal_pending() below
 	 * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
-	 * done by the caller to avoid the race with signal_wake_up().
+	 * done by the caller to avoid the race with signal_wake_up():
 	 *
-	 * The membarrier system call requires a full memory barrier
+	 * __set_current_state(@state)		signal_wake_up()
+	 * schedule()				  set_tsk_thread_flag(p, TIF_SIGPENDING)
+	 *					  wake_up_state(p, state)
+	 *   LOCK rq->lock			    LOCK p->pi_state
+	 *   smp_mb__after_spinlock()		    smp_mb__after_spinlock()
+	 *     if (signal_pending_state())	    if (p->state & @state)
+	 *
+	 * Also, the membarrier system call requires a full memory barrier
 	 * after coming from user-space, before storing to rq->curr.
 	 */
 	rq_lock(rq, &rf);
@@ -4131,10 +4463,38 @@
 	update_rq_clock(rq);
 
 	switch_count = &prev->nivcsw;
-	if (!preempt && prev->state) {
-		if (signal_pending_state(prev->state, prev)) {
+
+	/*
+	 * We must load prev->state once (task_struct::state is volatile), such
+	 * that:
+	 *
+	 *  - we form a control dependency vs deactivate_task() below.
+	 *  - ptrace_{,un}freeze_traced() can change ->state underneath us.
+	 */
+	prev_state = prev->state;
+	if (!preempt && prev_state) {
+		if (signal_pending_state(prev_state, prev)) {
 			prev->state = TASK_RUNNING;
 		} else {
+			prev->sched_contributes_to_load =
+				(prev_state & TASK_UNINTERRUPTIBLE) &&
+				!(prev_state & TASK_NOLOAD) &&
+				!(prev->flags & PF_FROZEN);
+
+			if (prev->sched_contributes_to_load)
+				rq->nr_uninterruptible++;
+
+			/*
+			 * __schedule()			ttwu()
+			 *   prev_state = prev->state;    if (p->on_rq && ...)
+			 *   if (prev_state)		    goto out;
+			 *     p->on_rq = 0;		  smp_acquire__after_ctrl_dep();
+			 *				  p->state = TASK_WAKING
+			 *
+			 * Where __schedule() and ttwu() have matching control dependencies.
+			 *
+			 * After this, schedule() must not care about p->state any more.
+			 */
 			deactivate_task(rq, prev, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK);
 
 			if (prev->in_iowait) {
@@ -4172,6 +4532,8 @@
 		 */
 		++*switch_count;
 
+		psi_sched_switch(prev, next, !task_on_rq_queued(prev));
+
 		trace_sched_switch(preempt, prev, next);
 
 		/* Also unlocks the rq: */
@@ -4202,9 +4564,12 @@
 
 static inline void sched_submit_work(struct task_struct *tsk)
 {
+	unsigned int task_flags;
+
 	if (!tsk->state)
 		return;
 
+	task_flags = tsk->flags;
 	/*
 	 * If a worker went to sleep, notify and ask workqueue whether
 	 * it wants to wake up a task to maintain concurrency.
@@ -4213,9 +4578,12 @@
 	 * in the possible wakeup of a kworker and because wq_worker_sleeping()
 	 * requires it.
 	 */
-	if (tsk->flags & PF_WQ_WORKER) {
+	if (task_flags & (PF_WQ_WORKER | PF_IO_WORKER)) {
 		preempt_disable();
-		wq_worker_sleeping(tsk);
+		if (task_flags & PF_WQ_WORKER)
+			wq_worker_sleeping(tsk);
+		else
+			io_wq_worker_sleeping(tsk);
 		preempt_enable_no_resched();
 	}
 
@@ -4232,8 +4600,12 @@
 
 static void sched_update_worker(struct task_struct *tsk)
 {
-	if (tsk->flags & PF_WQ_WORKER)
-		wq_worker_running(tsk);
+	if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) {
+		if (tsk->flags & PF_WQ_WORKER)
+			wq_worker_running(tsk);
+		else
+			io_wq_worker_running(tsk);
+	}
 }
 
 asmlinkage __visible void __sched schedule(void)
@@ -4437,10 +4809,23 @@
 int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags,
 			  void *key)
 {
+	WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~WF_SYNC);
 	return try_to_wake_up(curr->private, mode, wake_flags);
 }
 EXPORT_SYMBOL(default_wake_function);
 
+static void __setscheduler_prio(struct task_struct *p, int prio)
+{
+	if (dl_prio(prio))
+		p->sched_class = &dl_sched_class;
+	else if (rt_prio(prio))
+		p->sched_class = &rt_sched_class;
+	else
+		p->sched_class = &fair_sched_class;
+
+	p->prio = prio;
+}
+
 #ifdef CONFIG_RT_MUTEXES
 
 static inline int __rt_effective_prio(struct task_struct *pi_task, int prio)
@@ -4551,26 +4936,24 @@
 		if (!dl_prio(p->normal_prio) ||
 		    (pi_task && dl_prio(pi_task->prio) &&
 		     dl_entity_preempt(&pi_task->dl, &p->dl))) {
-			p->dl.dl_boosted = 1;
+			p->dl.pi_se = pi_task->dl.pi_se;
 			queue_flag |= ENQUEUE_REPLENISH;
-		} else
-			p->dl.dl_boosted = 0;
-		p->sched_class = &dl_sched_class;
+		} else {
+			p->dl.pi_se = &p->dl;
+		}
 	} else if (rt_prio(prio)) {
 		if (dl_prio(oldprio))
-			p->dl.dl_boosted = 0;
+			p->dl.pi_se = &p->dl;
 		if (oldprio < prio)
 			queue_flag |= ENQUEUE_HEAD;
-		p->sched_class = &rt_sched_class;
 	} else {
 		if (dl_prio(oldprio))
-			p->dl.dl_boosted = 0;
+			p->dl.pi_se = &p->dl;
 		if (rt_prio(oldprio))
 			p->rt.timeout = 0;
-		p->sched_class = &fair_sched_class;
 	}
 
-	p->prio = prio;
+	__setscheduler_prio(p, prio);
 
 	if (queued)
 		enqueue_task(rq, p, queue_flag);
@@ -4596,7 +4979,7 @@
 void set_user_nice(struct task_struct *p, long nice)
 {
 	bool queued, running;
-	int old_prio, delta;
+	int old_prio;
 	struct rq_flags rf;
 	struct rq *rq;
 
@@ -4630,19 +5013,18 @@
 	set_load_weight(p, true);
 	old_prio = p->prio;
 	p->prio = effective_prio(p);
-	delta = p->prio - old_prio;
 
-	if (queued) {
+	if (queued)
 		enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK);
-		/*
-		 * If the task increased its priority or is running and
-		 * lowered its priority, then reschedule its CPU:
-		 */
-		if (delta < 0 || (delta > 0 && task_running(rq, p)))
-			resched_curr(rq);
-	}
 	if (running)
 		set_next_task(rq, p);
+
+	/*
+	 * If the task increased its priority or is running and
+	 * lowered its priority, then reschedule its CPU:
+	 */
+	p->sched_class->prio_changed(rq, p, old_prio);
+
 out_unlock:
 	task_rq_unlock(rq, p, &rf);
 }
@@ -4727,7 +5109,7 @@
 		return 0;
 
 #ifdef CONFIG_SMP
-	if (!llist_empty(&rq->wake_list))
+	if (rq->ttwu_pending)
 		return 0;
 #endif
 
@@ -4804,35 +5186,6 @@
 	set_load_weight(p, true);
 }
 
-/* Actually do priority change: must hold pi & rq lock. */
-static void __setscheduler(struct rq *rq, struct task_struct *p,
-			   const struct sched_attr *attr, bool keep_boost)
-{
-	/*
-	 * If params can't change scheduling class changes aren't allowed
-	 * either.
-	 */
-	if (attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)
-		return;
-
-	__setscheduler_params(p, attr);
-
-	/*
-	 * Keep a potential priority boosting if called from
-	 * sched_setscheduler().
-	 */
-	p->prio = normal_prio(p);
-	if (keep_boost)
-		p->prio = rt_effective_prio(p, p->prio);
-
-	if (dl_prio(p->prio))
-		p->sched_class = &dl_sched_class;
-	else if (rt_prio(p->prio))
-		p->sched_class = &rt_sched_class;
-	else
-		p->sched_class = &fair_sched_class;
-}
-
 /*
  * Check the target process has a UID that matches the current process's:
  */
@@ -4853,10 +5206,8 @@
 				const struct sched_attr *attr,
 				bool user, bool pi)
 {
-	int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 :
-		      MAX_RT_PRIO - 1 - attr->sched_priority;
-	int retval, oldprio, oldpolicy = -1, queued, running;
-	int new_effective_prio, policy = attr->sched_policy;
+	int oldpolicy = -1, policy = attr->sched_policy;
+	int retval, oldprio, newprio, queued, running;
 	const struct sched_class *prev_class;
 	struct rq_flags rf;
 	int reset_on_fork;
@@ -5054,6 +5405,7 @@
 	p->sched_reset_on_fork = reset_on_fork;
 	oldprio = p->prio;
 
+	newprio = __normal_prio(policy, attr->sched_priority, attr->sched_nice);
 	if (pi) {
 		/*
 		 * Take priority boosted tasks into account. If the new
@@ -5062,8 +5414,8 @@
 		 * the runqueue. This will be done when the task deboost
 		 * itself.
 		 */
-		new_effective_prio = rt_effective_prio(p, newprio);
-		if (new_effective_prio == oldprio)
+		newprio = rt_effective_prio(p, newprio);
+		if (newprio == oldprio)
 			queue_flags &= ~DEQUEUE_MOVE;
 	}
 
@@ -5076,7 +5428,10 @@
 
 	prev_class = p->sched_class;
 
-	__setscheduler(rq, p, attr, pi);
+	if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) {
+		__setscheduler_params(p, attr);
+		__setscheduler_prio(p, newprio);
+	}
 	__setscheduler_uclamp(p, attr);
 
 	if (queued) {
@@ -5140,6 +5495,8 @@
  * @policy: new policy.
  * @param: structure containing the new RT priority.
  *
+ * Use sched_set_fifo(), read its comment.
+ *
  * Return: 0 on success. An error code otherwise.
  *
  * NOTE that the task may be already dead.
@@ -5149,13 +5506,11 @@
 {
 	return _sched_setscheduler(p, policy, param, true);
 }
-EXPORT_SYMBOL_GPL(sched_setscheduler);
 
 int sched_setattr(struct task_struct *p, const struct sched_attr *attr)
 {
 	return __sched_setscheduler(p, attr, true, true);
 }
-EXPORT_SYMBOL_GPL(sched_setattr);
 
 int sched_setattr_nocheck(struct task_struct *p, const struct sched_attr *attr)
 {
@@ -5180,7 +5535,51 @@
 {
 	return _sched_setscheduler(p, policy, param, false);
 }
-EXPORT_SYMBOL_GPL(sched_setscheduler_nocheck);
+
+/*
+ * SCHED_FIFO is a broken scheduler model; that is, it is fundamentally
+ * incapable of resource management, which is the one thing an OS really should
+ * be doing.
+ *
+ * This is of course the reason it is limited to privileged users only.
+ *
+ * Worse still; it is fundamentally impossible to compose static priority
+ * workloads. You cannot take two correctly working static prio workloads
+ * and smash them together and still expect them to work.
+ *
+ * For this reason 'all' FIFO tasks the kernel creates are basically at:
+ *
+ *   MAX_RT_PRIO / 2
+ *
+ * The administrator _MUST_ configure the system, the kernel simply doesn't
+ * know enough information to make a sensible choice.
+ */
+void sched_set_fifo(struct task_struct *p)
+{
+	struct sched_param sp = { .sched_priority = MAX_RT_PRIO / 2 };
+	WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0);
+}
+EXPORT_SYMBOL_GPL(sched_set_fifo);
+
+/*
+ * For when you don't much care about FIFO, but want to be above SCHED_NORMAL.
+ */
+void sched_set_fifo_low(struct task_struct *p)
+{
+	struct sched_param sp = { .sched_priority = 1 };
+	WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0);
+}
+EXPORT_SYMBOL_GPL(sched_set_fifo_low);
+
+void sched_set_normal(struct task_struct *p, int nice)
+{
+	struct sched_attr attr = {
+		.sched_policy = SCHED_NORMAL,
+		.sched_nice = nice,
+	};
+	WARN_ON_ONCE(sched_setattr_nocheck(p, &attr) != 0);
+}
+EXPORT_SYMBOL_GPL(sched_set_normal);
 
 static int
 do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
@@ -5471,6 +5870,11 @@
 		kattr.sched_nice = task_nice(p);
 
 #ifdef CONFIG_UCLAMP_TASK
+	/*
+	 * This could race with another potential updater, but this is fine
+	 * because it'll correctly read the old or the new value. We don't need
+	 * to guarantee who wins the race as long as it doesn't return garbage.
+	 */
 	kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value;
 	kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value;
 #endif
@@ -5824,7 +6228,7 @@
 	if (task_running(p_rq, p) || p->state)
 		goto out_unlock;
 
-	yielded = curr->sched_class->yield_to_task(rq, p, preempt);
+	yielded = curr->sched_class->yield_to_task(rq, p);
 	if (yielded) {
 		schedstat_inc(rq->yld_count);
 		/*
@@ -6022,10 +6426,10 @@
 	if (!try_get_task_stack(p))
 		return;
 
-	printk(KERN_INFO "%-15.15s %c", p->comm, task_state_to_char(p));
+	pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p));
 
 	if (p->state == TASK_RUNNING)
-		printk(KERN_CONT "  running task    ");
+		pr_cont("  running task    ");
 #ifdef CONFIG_DEBUG_STACK_USAGE
 	free = stack_not_used(p);
 #endif
@@ -6034,12 +6438,12 @@
 	if (pid_alive(p))
 		ppid = task_pid_nr(rcu_dereference(p->real_parent));
 	rcu_read_unlock();
-	printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
-		task_pid_nr(p), ppid,
+	pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx\n",
+		free, task_pid_nr(p), ppid,
 		(unsigned long)task_thread_info(p)->flags);
 
 	print_worker_info(KERN_INFO, p);
-	show_stack(p, NULL);
+	show_stack(p, NULL, KERN_INFO);
 	put_task_stack(p);
 }
 EXPORT_SYMBOL_GPL(sched_show_task);
@@ -6070,13 +6474,6 @@
 {
 	struct task_struct *g, *p;
 
-#if BITS_PER_LONG == 32
-	printk(KERN_INFO
-		"  task                PC stack   pid father\n");
-#else
-	printk(KERN_INFO
-		"  task                        PC stack   pid father\n");
-#endif
 	rcu_read_lock();
 	for_each_process_thread(g, p) {
 		/*
@@ -6112,7 +6509,7 @@
  * NOTE: this function does not set the idle thread's NEED_RESCHED
  * flag, to make booting more robust.
  */
-void init_idle(struct task_struct *idle, int cpu)
+void __init init_idle(struct task_struct *idle, int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
 	unsigned long flags;
@@ -6126,8 +6523,6 @@
 	idle->se.exec_start = sched_clock();
 	idle->flags |= PF_IDLE;
 
-	kasan_unpoison_task_stack(idle);
-
 #ifdef CONFIG_SMP
 	/*
 	 * Its possible that init_idle() gets called multiple times on a task,
@@ -6308,7 +6703,7 @@
 	struct task_struct *next;
 
 	for_each_class(class) {
-		next = class->pick_next_task(rq, NULL, NULL);
+		next = class->pick_next_task(rq);
 		if (next) {
 			next->sched_class->put_prev_task(rq, next);
 			return next;
@@ -6573,7 +6968,6 @@
 	struct rq_flags rf;
 
 	/* Handle pending wakeups and then migrate everything off */
-	sched_ttwu_pending();
 	sched_tick_stop(cpu);
 
 	rq_lock_irqsave(rq, &rf);
@@ -6658,6 +7052,14 @@
 	unsigned long ptr = 0;
 	int i;
 
+	/* Make sure the linker didn't screw up */
+	BUG_ON(&idle_sched_class + 1 != &fair_sched_class ||
+	       &fair_sched_class + 1 != &rt_sched_class ||
+	       &rt_sched_class + 1   != &dl_sched_class);
+#ifdef CONFIG_SMP
+	BUG_ON(&dl_sched_class + 1 != &stop_sched_class);
+#endif
+
 	wait_bit_init();
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -6676,6 +7078,8 @@
 		root_task_group.cfs_rq = (struct cfs_rq **)ptr;
 		ptr += nr_cpu_ids * sizeof(void **);
 
+		root_task_group.shares = ROOT_TASK_GROUP_LOAD;
+		init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 #ifdef CONFIG_RT_GROUP_SCHED
 		root_task_group.rt_se = (struct sched_rt_entity **)ptr;
@@ -6728,7 +7132,6 @@
 		init_rt_rq(&rq->rt);
 		init_dl_rq(&rq->dl);
 #ifdef CONFIG_FAIR_GROUP_SCHED
-		root_task_group.shares = ROOT_TASK_GROUP_LOAD;
 		INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
 		rq->tmp_alone_branch = &rq->leaf_cfs_rq_list;
 		/*
@@ -6750,7 +7153,6 @@
 		 * We achieve this by letting root_task_group's tasks sit
 		 * directly in rq->cfs (i.e root_task_group->se[] = NULL).
 		 */
-		init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
 		init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL);
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
@@ -6776,9 +7178,10 @@
 
 		rq_attach_root(rq, &def_root_domain);
 #ifdef CONFIG_NO_HZ_COMMON
-		rq->last_load_update_tick = jiffies;
 		rq->last_blocked_load_update_tick = jiffies;
 		atomic_set(&rq->nohz_flags, 0);
+
+		rq_csd_init(rq, &rq->nohz_csd, nohz_csd_func);
 #endif
 #endif /* CONFIG_SMP */
 		hrtick_rq_init(rq);
@@ -6883,8 +7286,7 @@
 	if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)
 	    && !preempt_count_equals(preempt_offset)) {
 		pr_err("Preemption disabled at:");
-		print_ip_sym(preempt_disable_ip);
-		pr_cont("\n");
+		print_ip_sym(KERN_ERR, preempt_disable_ip);
 	}
 	dump_stack();
 	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
@@ -8075,4 +8477,7 @@
  /*  15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
 };
 
-#undef CREATE_TRACE_POINTS
+void call_trace_sched_update_nr_running(struct rq *rq, int count)
+{
+        trace_sched_update_nr_running_tp(rq, count);
+}
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 9fbb103..941c28c 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -5,6 +5,7 @@
  * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
  * (balbir@in.ibm.com).
  */
+#include <asm/irq_regs.h>
 #include "sched.h"
 
 /* Time spent by the tasks of the CPU accounting group executing in ... */
@@ -339,7 +340,7 @@
 {
 	struct cpuacct *ca;
 	int index = CPUACCT_STAT_SYSTEM;
-	struct pt_regs *regs = task_pt_regs(tsk);
+	struct pt_regs *regs = get_irq_regs() ? : task_pt_regs(tsk);
 
 	if (regs && user_mode(regs))
 		index = CPUACCT_STAT_USER;
@@ -347,7 +348,7 @@
 	rcu_read_lock();
 
 	for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
-		this_cpu_ptr(ca->cpuusage)->usages[index] += cputime;
+		__this_cpu_add(ca->cpuusage->usages[index], cputime);
 
 	rcu_read_unlock();
 }
@@ -363,7 +364,7 @@
 
 	rcu_read_lock();
 	for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca))
-		this_cpu_ptr(ca->cpustat)->cpustat[index] += val;
+		__this_cpu_add(ca->cpustat->cpustat[index], val);
 	rcu_read_unlock();
 }
 
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 5cc4012..8cb06c8 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -121,6 +121,30 @@
 
 	if (later_mask &&
 	    cpumask_and(later_mask, cp->free_cpus, p->cpus_ptr)) {
+		unsigned long cap, max_cap = 0;
+		int cpu, max_cpu = -1;
+
+		if (!static_branch_unlikely(&sched_asym_cpucapacity))
+			return 1;
+
+		/* Ensure the capacity of the CPUs fits the task. */
+		for_each_cpu(cpu, later_mask) {
+			if (!dl_task_fits_capacity(p, cpu)) {
+				cpumask_clear_cpu(cpu, later_mask);
+
+				cap = capacity_orig_of(cpu);
+
+				if (cap > max_cap ||
+				    (cpu == task_cpu(p) && cap == max_cap)) {
+					max_cap = cap;
+					max_cpu = cpu;
+				}
+			}
+		}
+
+		if (cpumask_empty(later_mask))
+			cpumask_set_cpu(max_cpu, later_mask);
+
 		return 1;
 	} else {
 		int best_cpu = cpudl_maximum(cp);
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 4cb80e6..5e39da0 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -102,8 +102,12 @@
 static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
 				   unsigned int next_freq)
 {
-	if (sg_policy->next_freq == next_freq)
-		return false;
+	if (!sg_policy->need_freq_update) {
+		if (sg_policy->next_freq == next_freq)
+			return false;
+	} else {
+		sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS);
+	}
 
 	sg_policy->next_freq = next_freq;
 	sg_policy->last_freq_update_time = time;
@@ -114,22 +118,8 @@
 static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time,
 			      unsigned int next_freq)
 {
-	struct cpufreq_policy *policy = sg_policy->policy;
-	int cpu;
-
-	if (!sugov_update_next_freq(sg_policy, time, next_freq))
-		return;
-
-	next_freq = cpufreq_driver_fast_switch(policy, next_freq);
-	if (!next_freq)
-		return;
-
-	policy->cur = next_freq;
-
-	if (trace_cpu_frequency_enabled()) {
-		for_each_cpu(cpu, policy->cpus)
-			trace_cpu_frequency(next_freq, cpu);
-	}
+	if (sugov_update_next_freq(sg_policy, time, next_freq))
+		cpufreq_driver_fast_switch(sg_policy->policy, next_freq);
 }
 
 static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time,
@@ -178,7 +168,6 @@
 	if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update)
 		return sg_policy->next_freq;
 
-	sg_policy->need_freq_update = false;
 	sg_policy->cached_raw_freq = freq;
 	return cpufreq_driver_resolve_freq(policy, freq);
 }
@@ -238,7 +227,7 @@
 	 */
 	util = util_cfs + cpu_util_rt(rq);
 	if (type == FREQUENCY_UTIL)
-		util = uclamp_util_with(rq, util, p);
+		util = uclamp_rq_util_with(rq, util, p);
 
 	dl_util = cpu_util_dl(rq);
 
@@ -454,7 +443,7 @@
 	struct sugov_policy *sg_policy = sg_cpu->sg_policy;
 	unsigned long util, max;
 	unsigned int next_f;
-	bool busy;
+	unsigned int cached_freq = sg_policy->cached_raw_freq;
 
 	sugov_iowait_boost(sg_cpu, time, flags);
 	sg_cpu->last_update = time;
@@ -464,9 +453,6 @@
 	if (!sugov_should_update_freq(sg_policy, time))
 		return;
 
-	/* Limits may have changed, don't skip frequency update */
-	busy = !sg_policy->need_freq_update && sugov_cpu_is_busy(sg_cpu);
-
 	util = sugov_get_util(sg_cpu);
 	max = sg_cpu->max;
 	util = sugov_iowait_apply(sg_cpu, time, util, max);
@@ -475,11 +461,11 @@
 	 * Do not reduce the frequency if the CPU has not been idle
 	 * recently, as the reduction is likely to be premature then.
 	 */
-	if (busy && next_f < sg_policy->next_freq) {
+	if (sugov_cpu_is_busy(sg_cpu) && next_f < sg_policy->next_freq) {
 		next_f = sg_policy->next_freq;
 
-		/* Reset cached freq as next_freq has changed */
-		sg_policy->cached_raw_freq = 0;
+		/* Restore cached freq as next_freq has changed */
+		sg_policy->cached_raw_freq = cached_freq;
 	}
 
 	/*
@@ -624,9 +610,17 @@
 };
 ATTRIBUTE_GROUPS(sugov);
 
+static void sugov_tunables_free(struct kobject *kobj)
+{
+	struct gov_attr_set *attr_set = container_of(kobj, struct gov_attr_set, kobj);
+
+	kfree(to_sugov_tunables(attr_set));
+}
+
 static struct kobj_type sugov_tunables_ktype = {
 	.default_groups = sugov_groups,
 	.sysfs_ops = &governor_sysfs_ops,
+	.release = &sugov_tunables_free,
 };
 
 /********************** cpufreq governor interface *********************/
@@ -726,12 +720,10 @@
 	return tunables;
 }
 
-static void sugov_tunables_free(struct sugov_tunables *tunables)
+static void sugov_clear_global_tunables(void)
 {
 	if (!have_governor_per_policy())
 		global_tunables = NULL;
-
-	kfree(tunables);
 }
 
 static int sugov_init(struct cpufreq_policy *policy)
@@ -794,7 +786,7 @@
 fail:
 	kobject_put(&tunables->attr_set.kobj);
 	policy->governor_data = NULL;
-	sugov_tunables_free(tunables);
+	sugov_clear_global_tunables();
 
 stop_kthread:
 	sugov_kthread_stop(sg_policy);
@@ -821,7 +813,7 @@
 	count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
 	policy->governor_data = NULL;
 	if (!count)
-		sugov_tunables_free(tunables);
+		sugov_clear_global_tunables();
 
 	mutex_unlock(&global_tunables_lock);
 
@@ -840,9 +832,10 @@
 	sg_policy->next_freq			= 0;
 	sg_policy->work_in_progress		= false;
 	sg_policy->limits_changed		= false;
-	sg_policy->need_freq_update		= false;
 	sg_policy->cached_raw_freq		= 0;
 
+	sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS);
+
 	for_each_cpu(cpu, policy->cpus) {
 		struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
 
@@ -894,7 +887,7 @@
 struct cpufreq_governor schedutil_gov = {
 	.name			= "schedutil",
 	.owner			= THIS_MODULE,
-	.dynamic_switching	= true,
+	.flags			= CPUFREQ_GOV_DYNAMIC_SWITCHING,
 	.init			= sugov_init,
 	.exit			= sugov_exit,
 	.start			= sugov_start,
@@ -909,11 +902,7 @@
 }
 #endif
 
-static int __init sugov_register(void)
-{
-	return cpufreq_register_governor(&schedutil_gov);
-}
-fs_initcall(sugov_register);
+cpufreq_governor_init(schedutil_gov);
 
 #ifdef CONFIG_ENERGY_MODEL
 extern bool sched_energy_update;
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index b7abca9..0033731 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -41,11 +41,72 @@
 	return cpupri;
 }
 
+static inline int __cpupri_find(struct cpupri *cp, struct task_struct *p,
+				struct cpumask *lowest_mask, int idx)
+{
+	struct cpupri_vec *vec  = &cp->pri_to_cpu[idx];
+	int skip = 0;
+
+	if (!atomic_read(&(vec)->count))
+		skip = 1;
+	/*
+	 * When looking at the vector, we need to read the counter,
+	 * do a memory barrier, then read the mask.
+	 *
+	 * Note: This is still all racey, but we can deal with it.
+	 *  Ideally, we only want to look at masks that are set.
+	 *
+	 *  If a mask is not set, then the only thing wrong is that we
+	 *  did a little more work than necessary.
+	 *
+	 *  If we read a zero count but the mask is set, because of the
+	 *  memory barriers, that can only happen when the highest prio
+	 *  task for a run queue has left the run queue, in which case,
+	 *  it will be followed by a pull. If the task we are processing
+	 *  fails to find a proper place to go, that pull request will
+	 *  pull this task if the run queue is running at a lower
+	 *  priority.
+	 */
+	smp_rmb();
+
+	/* Need to do the rmb for every iteration */
+	if (skip)
+		return 0;
+
+	if (cpumask_any_and(p->cpus_ptr, vec->mask) >= nr_cpu_ids)
+		return 0;
+
+	if (lowest_mask) {
+		cpumask_and(lowest_mask, p->cpus_ptr, vec->mask);
+
+		/*
+		 * We have to ensure that we have at least one bit
+		 * still set in the array, since the map could have
+		 * been concurrently emptied between the first and
+		 * second reads of vec->mask.  If we hit this
+		 * condition, simply act as though we never hit this
+		 * priority level and continue on.
+		 */
+		if (cpumask_empty(lowest_mask))
+			return 0;
+	}
+
+	return 1;
+}
+
+int cpupri_find(struct cpupri *cp, struct task_struct *p,
+		struct cpumask *lowest_mask)
+{
+	return cpupri_find_fitness(cp, p, lowest_mask, NULL);
+}
+
 /**
- * cpupri_find - find the best (lowest-pri) CPU in the system
+ * cpupri_find_fitness - find the best (lowest-pri) CPU in the system
  * @cp: The cpupri context
  * @p: The task
  * @lowest_mask: A mask to fill in with selected CPUs (or NULL)
+ * @fitness_fn: A pointer to a function to do custom checks whether the CPU
+ *              fits a specific criteria so that we only return those CPUs.
  *
  * Note: This function returns the recommended CPUs as calculated during the
  * current invocation.  By the time the call returns, the CPUs may have in
@@ -56,65 +117,59 @@
  *
  * Return: (int)bool - CPUs were found
  */
-int cpupri_find(struct cpupri *cp, struct task_struct *p,
-		struct cpumask *lowest_mask)
+int cpupri_find_fitness(struct cpupri *cp, struct task_struct *p,
+		struct cpumask *lowest_mask,
+		bool (*fitness_fn)(struct task_struct *p, int cpu))
 {
-	int idx = 0;
 	int task_pri = convert_prio(p->prio);
+	int idx, cpu;
 
 	BUG_ON(task_pri >= CPUPRI_NR_PRIORITIES);
 
 	for (idx = 0; idx < task_pri; idx++) {
-		struct cpupri_vec *vec  = &cp->pri_to_cpu[idx];
-		int skip = 0;
 
-		if (!atomic_read(&(vec)->count))
-			skip = 1;
-		/*
-		 * When looking at the vector, we need to read the counter,
-		 * do a memory barrier, then read the mask.
-		 *
-		 * Note: This is still all racey, but we can deal with it.
-		 *  Ideally, we only want to look at masks that are set.
-		 *
-		 *  If a mask is not set, then the only thing wrong is that we
-		 *  did a little more work than necessary.
-		 *
-		 *  If we read a zero count but the mask is set, because of the
-		 *  memory barriers, that can only happen when the highest prio
-		 *  task for a run queue has left the run queue, in which case,
-		 *  it will be followed by a pull. If the task we are processing
-		 *  fails to find a proper place to go, that pull request will
-		 *  pull this task if the run queue is running at a lower
-		 *  priority.
-		 */
-		smp_rmb();
-
-		/* Need to do the rmb for every iteration */
-		if (skip)
+		if (!__cpupri_find(cp, p, lowest_mask, idx))
 			continue;
 
-		if (cpumask_any_and(p->cpus_ptr, vec->mask) >= nr_cpu_ids)
-			continue;
+		if (!lowest_mask || !fitness_fn)
+			return 1;
 
-		if (lowest_mask) {
-			cpumask_and(lowest_mask, p->cpus_ptr, vec->mask);
-
-			/*
-			 * We have to ensure that we have at least one bit
-			 * still set in the array, since the map could have
-			 * been concurrently emptied between the first and
-			 * second reads of vec->mask.  If we hit this
-			 * condition, simply act as though we never hit this
-			 * priority level and continue on.
-			 */
-			if (cpumask_any(lowest_mask) >= nr_cpu_ids)
-				continue;
+		/* Ensure the capacity of the CPUs fit the task */
+		for_each_cpu(cpu, lowest_mask) {
+			if (!fitness_fn(p, cpu))
+				cpumask_clear_cpu(cpu, lowest_mask);
 		}
 
+		/*
+		 * If no CPU at the current priority can fit the task
+		 * continue looking
+		 */
+		if (cpumask_empty(lowest_mask))
+			continue;
+
 		return 1;
 	}
 
+	/*
+	 * If we failed to find a fitting lowest_mask, kick off a new search
+	 * but without taking into account any fitness criteria this time.
+	 *
+	 * This rule favours honouring priority over fitting the task in the
+	 * correct CPU (Capacity Awareness being the only user now).
+	 * The idea is that if a higher priority task can run, then it should
+	 * run even if this ends up being on unfitting CPU.
+	 *
+	 * The cost of this trade-off is not entirely clear and will probably
+	 * be good for some workloads and bad for others.
+	 *
+	 * The main idea here is that if some CPUs were overcommitted, we try
+	 * to spread which is what the scheduler traditionally did. Sys admins
+	 * must do proper RT planning to avoid overloading the system if they
+	 * really care.
+	 */
+	if (fitness_fn)
+		return cpupri_find(cp, p, lowest_mask);
+
 	return 0;
 }
 
diff --git a/kernel/sched/cpupri.h b/kernel/sched/cpupri.h
index 7dc20a3..efbb492 100644
--- a/kernel/sched/cpupri.h
+++ b/kernel/sched/cpupri.h
@@ -18,7 +18,11 @@
 };
 
 #ifdef CONFIG_SMP
-int  cpupri_find(struct cpupri *cp, struct task_struct *p, struct cpumask *lowest_mask);
+int  cpupri_find(struct cpupri *cp, struct task_struct *p,
+		 struct cpumask *lowest_mask);
+int  cpupri_find_fitness(struct cpupri *cp, struct task_struct *p,
+			 struct cpumask *lowest_mask,
+			 bool (*fitness_fn)(struct task_struct *p, int cpu));
 void cpupri_set(struct cpupri *cp, int cpu, int pri);
 int  cpupri_init(struct cpupri *cp);
 void cpupri_cleanup(struct cpupri *cp);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 46ed4e1..ca0eef7 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -147,10 +147,10 @@
 
 	/* Add guest time to cpustat. */
 	if (task_nice(p) > 0) {
-		cpustat[CPUTIME_NICE] += cputime;
+		task_group_account_field(p, CPUTIME_NICE, cputime);
 		cpustat[CPUTIME_GUEST_NICE] += cputime;
 	} else {
-		cpustat[CPUTIME_USER] += cputime;
+		task_group_account_field(p, CPUTIME_USER, cputime);
 		cpustat[CPUTIME_GUEST] += cputime;
 	}
 }
@@ -355,7 +355,7 @@
  * softirq as those do not count in task exec_runtime any more.
  */
 static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
-					 struct rq *rq, int ticks)
+					 int ticks)
 {
 	u64 other, cputime = TICK_NSEC * ticks;
 
@@ -381,7 +381,7 @@
 		account_system_index_time(p, cputime, CPUTIME_SOFTIRQ);
 	} else if (user_tick) {
 		account_user_time(p, cputime);
-	} else if (p == rq->idle) {
+	} else if (p == this_rq()->idle) {
 		account_idle_time(cputime);
 	} else if (p->flags & PF_VCPU) { /* System time or guest time */
 		account_guest_time(p, cputime);
@@ -392,40 +392,36 @@
 
 static void irqtime_account_idle_ticks(int ticks)
 {
-	struct rq *rq = this_rq();
-
-	irqtime_account_process_tick(current, 0, rq, ticks);
+	irqtime_account_process_tick(current, 0, ticks);
 }
 #else /* CONFIG_IRQ_TIME_ACCOUNTING */
 static inline void irqtime_account_idle_ticks(int ticks) { }
 static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick,
-						struct rq *rq, int nr_ticks) { }
+						int nr_ticks) { }
 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
 
 /*
  * Use precise platform statistics if available:
  */
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+
 # ifndef __ARCH_HAS_VTIME_TASK_SWITCH
-void vtime_common_task_switch(struct task_struct *prev)
+void vtime_task_switch(struct task_struct *prev)
 {
 	if (is_idle_task(prev))
 		vtime_account_idle(prev);
 	else
-		vtime_account_system(prev);
+		vtime_account_kernel(prev);
 
 	vtime_flush(prev);
 	arch_vtime_task_switch(prev);
 }
 # endif
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
 
-
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 /*
  * Archs that account the whole time spent in the idle task
  * (outside irq) as idle time can rely on this and just implement
- * vtime_account_system() and vtime_account_idle(). Archs that
+ * vtime_account_kernel() and vtime_account_idle(). Archs that
  * have other meaning of the idle time (s390 only includes the
  * time spent by the CPU when it's in low power mode) must override
  * vtime_account().
@@ -436,7 +432,7 @@
 	if (!in_interrupt() && is_idle_task(tsk))
 		vtime_account_idle(tsk);
 	else
-		vtime_account_system(tsk);
+		vtime_account_kernel(tsk);
 }
 EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
 #endif /* __ARCH_HAS_VTIME_ACCOUNT */
@@ -475,13 +471,12 @@
 void account_process_tick(struct task_struct *p, int user_tick)
 {
 	u64 cputime, steal;
-	struct rq *rq = this_rq();
 
-	if (vtime_accounting_cpu_enabled())
+	if (vtime_accounting_enabled_this_cpu())
 		return;
 
 	if (sched_clock_irqtime) {
-		irqtime_account_process_tick(p, user_tick, rq, 1);
+		irqtime_account_process_tick(p, user_tick, 1);
 		return;
 	}
 
@@ -495,7 +490,7 @@
 
 	if (user_tick)
 		account_user_time(p, cputime);
-	else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
+	else if ((p != this_rq()->idle) || (irq_count() != HARDIRQ_OFFSET))
 		account_system_time(p, HARDIRQ_OFFSET, cputime);
 	else
 		account_idle_time(cputime);
@@ -525,50 +520,6 @@
 }
 
 /*
- * Perform (stime * rtime) / total, but avoid multiplication overflow by
- * losing precision when the numbers are big.
- */
-static u64 scale_stime(u64 stime, u64 rtime, u64 total)
-{
-	u64 scaled;
-
-	for (;;) {
-		/* Make sure "rtime" is the bigger of stime/rtime */
-		if (stime > rtime)
-			swap(rtime, stime);
-
-		/* Make sure 'total' fits in 32 bits */
-		if (total >> 32)
-			goto drop_precision;
-
-		/* Does rtime (and thus stime) fit in 32 bits? */
-		if (!(rtime >> 32))
-			break;
-
-		/* Can we just balance rtime/stime rather than dropping bits? */
-		if (stime >> 31)
-			goto drop_precision;
-
-		/* We can grow stime and shrink rtime and try to make them both fit */
-		stime <<= 1;
-		rtime >>= 1;
-		continue;
-
-drop_precision:
-		/* We drop from rtime, it has more bits than stime */
-		rtime >>= 1;
-		total >>= 1;
-	}
-
-	/*
-	 * Make sure gcc understands that this is a 32x32->64 multiply,
-	 * followed by a 64/32->64 divide.
-	 */
-	scaled = div_u64((u64) (u32) stime * (u64) (u32) rtime, (u32)total);
-	return scaled;
-}
-
-/*
  * Adjust tick based cputime random precision against scheduler runtime
  * accounting.
  *
@@ -627,7 +578,7 @@
 		goto update;
 	}
 
-	stime = scale_stime(stime, rtime, stime + utime);
+	stime = mul_u64_u64_div_u64(stime, rtime, stime + utime);
 
 update:
 	/*
@@ -711,8 +662,8 @@
 	return delta - other;
 }
 
-static void __vtime_account_system(struct task_struct *tsk,
-				   struct vtime *vtime)
+static void vtime_account_system(struct task_struct *tsk,
+				 struct vtime *vtime)
 {
 	vtime->stime += get_vtime_delta(vtime);
 	if (vtime->stime >= TICK_NSEC) {
@@ -731,7 +682,17 @@
 	}
 }
 
-void vtime_account_system(struct task_struct *tsk)
+static void __vtime_account_kernel(struct task_struct *tsk,
+				   struct vtime *vtime)
+{
+	/* We might have scheduled out from guest path */
+	if (vtime->state == VTIME_GUEST)
+		vtime_account_guest(tsk, vtime);
+	else
+		vtime_account_system(tsk, vtime);
+}
+
+void vtime_account_kernel(struct task_struct *tsk)
 {
 	struct vtime *vtime = &tsk->vtime;
 
@@ -739,11 +700,7 @@
 		return;
 
 	write_seqcount_begin(&vtime->seqcount);
-	/* We might have scheduled out from guest path */
-	if (tsk->flags & PF_VCPU)
-		vtime_account_guest(tsk, vtime);
-	else
-		__vtime_account_system(tsk, vtime);
+	__vtime_account_kernel(tsk, vtime);
 	write_seqcount_end(&vtime->seqcount);
 }
 
@@ -752,7 +709,7 @@
 	struct vtime *vtime = &tsk->vtime;
 
 	write_seqcount_begin(&vtime->seqcount);
-	__vtime_account_system(tsk, vtime);
+	vtime_account_system(tsk, vtime);
 	vtime->state = VTIME_USER;
 	write_seqcount_end(&vtime->seqcount);
 }
@@ -782,8 +739,9 @@
 	 * that can thus safely catch up with a tickless delta.
 	 */
 	write_seqcount_begin(&vtime->seqcount);
-	__vtime_account_system(tsk, vtime);
+	vtime_account_system(tsk, vtime);
 	tsk->flags |= PF_VCPU;
+	vtime->state = VTIME_GUEST;
 	write_seqcount_end(&vtime->seqcount);
 }
 EXPORT_SYMBOL_GPL(vtime_guest_enter);
@@ -795,6 +753,7 @@
 	write_seqcount_begin(&vtime->seqcount);
 	vtime_account_guest(tsk, vtime);
 	tsk->flags &= ~PF_VCPU;
+	vtime->state = VTIME_SYS;
 	write_seqcount_end(&vtime->seqcount);
 }
 EXPORT_SYMBOL_GPL(vtime_guest_exit);
@@ -804,19 +763,30 @@
 	account_idle_time(get_vtime_delta(&tsk->vtime));
 }
 
-void arch_vtime_task_switch(struct task_struct *prev)
+void vtime_task_switch_generic(struct task_struct *prev)
 {
 	struct vtime *vtime = &prev->vtime;
 
 	write_seqcount_begin(&vtime->seqcount);
+	if (vtime->state == VTIME_IDLE)
+		vtime_account_idle(prev);
+	else
+		__vtime_account_kernel(prev, vtime);
 	vtime->state = VTIME_INACTIVE;
+	vtime->cpu = -1;
 	write_seqcount_end(&vtime->seqcount);
 
 	vtime = &current->vtime;
 
 	write_seqcount_begin(&vtime->seqcount);
-	vtime->state = VTIME_SYS;
+	if (is_idle_task(current))
+		vtime->state = VTIME_IDLE;
+	else if (current->flags & PF_VCPU)
+		vtime->state = VTIME_GUEST;
+	else
+		vtime->state = VTIME_SYS;
 	vtime->starttime = sched_clock();
+	vtime->cpu = smp_processor_id();
 	write_seqcount_end(&vtime->seqcount);
 }
 
@@ -827,8 +797,9 @@
 
 	local_irq_save(flags);
 	write_seqcount_begin(&vtime->seqcount);
-	vtime->state = VTIME_SYS;
+	vtime->state = VTIME_IDLE;
 	vtime->starttime = sched_clock();
+	vtime->cpu = cpu;
 	write_seqcount_end(&vtime->seqcount);
 	local_irq_restore(flags);
 }
@@ -846,7 +817,7 @@
 		seq = read_seqcount_begin(&vtime->seqcount);
 
 		gtime = t->gtime;
-		if (vtime->state == VTIME_SYS && t->flags & PF_VCPU)
+		if (vtime->state == VTIME_GUEST)
 			gtime += vtime->gtime + vtime_delta(vtime);
 
 	} while (read_seqcount_retry(&vtime->seqcount, seq));
@@ -877,20 +848,233 @@
 		*utime = t->utime;
 		*stime = t->stime;
 
-		/* Task is sleeping, nothing to add */
-		if (vtime->state == VTIME_INACTIVE || is_idle_task(t))
+		/* Task is sleeping or idle, nothing to add */
+		if (vtime->state < VTIME_SYS)
 			continue;
 
 		delta = vtime_delta(vtime);
 
 		/*
-		 * Task runs either in user or kernel space, add pending nohz time to
-		 * the right place.
+		 * Task runs either in user (including guest) or kernel space,
+		 * add pending nohz time to the right place.
 		 */
-		if (vtime->state == VTIME_USER || t->flags & PF_VCPU)
-			*utime += vtime->utime + delta;
-		else if (vtime->state == VTIME_SYS)
+		if (vtime->state == VTIME_SYS)
 			*stime += vtime->stime + delta;
+		else
+			*utime += vtime->utime + delta;
 	} while (read_seqcount_retry(&vtime->seqcount, seq));
 }
+
+static int vtime_state_fetch(struct vtime *vtime, int cpu)
+{
+	int state = READ_ONCE(vtime->state);
+
+	/*
+	 * We raced against a context switch, fetch the
+	 * kcpustat task again.
+	 */
+	if (vtime->cpu != cpu && vtime->cpu != -1)
+		return -EAGAIN;
+
+	/*
+	 * Two possible things here:
+	 * 1) We are seeing the scheduling out task (prev) or any past one.
+	 * 2) We are seeing the scheduling in task (next) but it hasn't
+	 *    passed though vtime_task_switch() yet so the pending
+	 *    cputime of the prev task may not be flushed yet.
+	 *
+	 * Case 1) is ok but 2) is not. So wait for a safe VTIME state.
+	 */
+	if (state == VTIME_INACTIVE)
+		return -EAGAIN;
+
+	return state;
+}
+
+static u64 kcpustat_user_vtime(struct vtime *vtime)
+{
+	if (vtime->state == VTIME_USER)
+		return vtime->utime + vtime_delta(vtime);
+	else if (vtime->state == VTIME_GUEST)
+		return vtime->gtime + vtime_delta(vtime);
+	return 0;
+}
+
+static int kcpustat_field_vtime(u64 *cpustat,
+				struct task_struct *tsk,
+				enum cpu_usage_stat usage,
+				int cpu, u64 *val)
+{
+	struct vtime *vtime = &tsk->vtime;
+	unsigned int seq;
+
+	do {
+		int state;
+
+		seq = read_seqcount_begin(&vtime->seqcount);
+
+		state = vtime_state_fetch(vtime, cpu);
+		if (state < 0)
+			return state;
+
+		*val = cpustat[usage];
+
+		/*
+		 * Nice VS unnice cputime accounting may be inaccurate if
+		 * the nice value has changed since the last vtime update.
+		 * But proper fix would involve interrupting target on nice
+		 * updates which is a no go on nohz_full (although the scheduler
+		 * may still interrupt the target if rescheduling is needed...)
+		 */
+		switch (usage) {
+		case CPUTIME_SYSTEM:
+			if (state == VTIME_SYS)
+				*val += vtime->stime + vtime_delta(vtime);
+			break;
+		case CPUTIME_USER:
+			if (task_nice(tsk) <= 0)
+				*val += kcpustat_user_vtime(vtime);
+			break;
+		case CPUTIME_NICE:
+			if (task_nice(tsk) > 0)
+				*val += kcpustat_user_vtime(vtime);
+			break;
+		case CPUTIME_GUEST:
+			if (state == VTIME_GUEST && task_nice(tsk) <= 0)
+				*val += vtime->gtime + vtime_delta(vtime);
+			break;
+		case CPUTIME_GUEST_NICE:
+			if (state == VTIME_GUEST && task_nice(tsk) > 0)
+				*val += vtime->gtime + vtime_delta(vtime);
+			break;
+		default:
+			break;
+		}
+	} while (read_seqcount_retry(&vtime->seqcount, seq));
+
+	return 0;
+}
+
+u64 kcpustat_field(struct kernel_cpustat *kcpustat,
+		   enum cpu_usage_stat usage, int cpu)
+{
+	u64 *cpustat = kcpustat->cpustat;
+	u64 val = cpustat[usage];
+	struct rq *rq;
+	int err;
+
+	if (!vtime_accounting_enabled_cpu(cpu))
+		return val;
+
+	rq = cpu_rq(cpu);
+
+	for (;;) {
+		struct task_struct *curr;
+
+		rcu_read_lock();
+		curr = rcu_dereference(rq->curr);
+		if (WARN_ON_ONCE(!curr)) {
+			rcu_read_unlock();
+			return cpustat[usage];
+		}
+
+		err = kcpustat_field_vtime(cpustat, curr, usage, cpu, &val);
+		rcu_read_unlock();
+
+		if (!err)
+			return val;
+
+		cpu_relax();
+	}
+}
+EXPORT_SYMBOL_GPL(kcpustat_field);
+
+static int kcpustat_cpu_fetch_vtime(struct kernel_cpustat *dst,
+				    const struct kernel_cpustat *src,
+				    struct task_struct *tsk, int cpu)
+{
+	struct vtime *vtime = &tsk->vtime;
+	unsigned int seq;
+
+	do {
+		u64 *cpustat;
+		u64 delta;
+		int state;
+
+		seq = read_seqcount_begin(&vtime->seqcount);
+
+		state = vtime_state_fetch(vtime, cpu);
+		if (state < 0)
+			return state;
+
+		*dst = *src;
+		cpustat = dst->cpustat;
+
+		/* Task is sleeping, dead or idle, nothing to add */
+		if (state < VTIME_SYS)
+			continue;
+
+		delta = vtime_delta(vtime);
+
+		/*
+		 * Task runs either in user (including guest) or kernel space,
+		 * add pending nohz time to the right place.
+		 */
+		if (state == VTIME_SYS) {
+			cpustat[CPUTIME_SYSTEM] += vtime->stime + delta;
+		} else if (state == VTIME_USER) {
+			if (task_nice(tsk) > 0)
+				cpustat[CPUTIME_NICE] += vtime->utime + delta;
+			else
+				cpustat[CPUTIME_USER] += vtime->utime + delta;
+		} else {
+			WARN_ON_ONCE(state != VTIME_GUEST);
+			if (task_nice(tsk) > 0) {
+				cpustat[CPUTIME_GUEST_NICE] += vtime->gtime + delta;
+				cpustat[CPUTIME_NICE] += vtime->gtime + delta;
+			} else {
+				cpustat[CPUTIME_GUEST] += vtime->gtime + delta;
+				cpustat[CPUTIME_USER] += vtime->gtime + delta;
+			}
+		}
+	} while (read_seqcount_retry(&vtime->seqcount, seq));
+
+	return 0;
+}
+
+void kcpustat_cpu_fetch(struct kernel_cpustat *dst, int cpu)
+{
+	const struct kernel_cpustat *src = &kcpustat_cpu(cpu);
+	struct rq *rq;
+	int err;
+
+	if (!vtime_accounting_enabled_cpu(cpu)) {
+		*dst = *src;
+		return;
+	}
+
+	rq = cpu_rq(cpu);
+
+	for (;;) {
+		struct task_struct *curr;
+
+		rcu_read_lock();
+		curr = rcu_dereference(rq->curr);
+		if (WARN_ON_ONCE(!curr)) {
+			rcu_read_unlock();
+			*dst = *src;
+			return;
+		}
+
+		err = kcpustat_cpu_fetch_vtime(dst, src, curr, cpu);
+		rcu_read_unlock();
+
+		if (!err)
+			return;
+
+		cpu_relax();
+	}
+}
+EXPORT_SYMBOL_GPL(kcpustat_cpu_fetch);
+
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 2bda9fd..a3ae00c 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -43,6 +43,28 @@
 	return !RB_EMPTY_NODE(&dl_se->rb_node);
 }
 
+#ifdef CONFIG_RT_MUTEXES
+static inline struct sched_dl_entity *pi_of(struct sched_dl_entity *dl_se)
+{
+	return dl_se->pi_se;
+}
+
+static inline bool is_dl_boosted(struct sched_dl_entity *dl_se)
+{
+	return pi_of(dl_se) != dl_se;
+}
+#else
+static inline struct sched_dl_entity *pi_of(struct sched_dl_entity *dl_se)
+{
+	return dl_se;
+}
+
+static inline bool is_dl_boosted(struct sched_dl_entity *dl_se)
+{
+	return false;
+}
+#endif
+
 #ifdef CONFIG_SMP
 static inline struct dl_bw *dl_bw_of(int i)
 {
@@ -54,15 +76,49 @@
 static inline int dl_bw_cpus(int i)
 {
 	struct root_domain *rd = cpu_rq(i)->rd;
-	int cpus = 0;
+	int cpus;
 
 	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
 			 "sched RCU must be held");
+
+	if (cpumask_subset(rd->span, cpu_active_mask))
+		return cpumask_weight(rd->span);
+
+	cpus = 0;
+
 	for_each_cpu_and(i, rd->span, cpu_active_mask)
 		cpus++;
 
 	return cpus;
 }
+
+static inline unsigned long __dl_bw_capacity(int i)
+{
+	struct root_domain *rd = cpu_rq(i)->rd;
+	unsigned long cap = 0;
+
+	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
+			 "sched RCU must be held");
+
+	for_each_cpu_and(i, rd->span, cpu_active_mask)
+		cap += capacity_orig_of(i);
+
+	return cap;
+}
+
+/*
+ * XXX Fix: If 'rq->rd == def_root_domain' perform AC against capacity
+ * of the CPU the task is running on rather rd's \Sum CPU capacity.
+ */
+static inline unsigned long dl_bw_capacity(int i)
+{
+	if (!static_branch_unlikely(&sched_asym_cpucapacity) &&
+	    capacity_orig_of(i) == SCHED_CAPACITY_SCALE) {
+		return dl_bw_cpus(i) << SCHED_CAPACITY_SHIFT;
+	} else {
+		return __dl_bw_capacity(i);
+	}
+}
 #else
 static inline struct dl_bw *dl_bw_of(int i)
 {
@@ -73,6 +129,11 @@
 {
 	return 1;
 }
+
+static inline unsigned long dl_bw_capacity(int i)
+{
+	return SCHED_CAPACITY_SCALE;
+}
 #endif
 
 static inline
@@ -153,7 +214,7 @@
 		__sub_running_bw(dl_se->dl_bw, dl_rq);
 }
 
-void dl_change_utilization(struct task_struct *p, u64 new_bw)
+static void dl_change_utilization(struct task_struct *p, u64 new_bw)
 {
 	struct rq *rq;
 
@@ -334,6 +395,8 @@
 	return dl_rq->root.rb_leftmost == &dl_se->rb_node;
 }
 
+static void init_dl_rq_bw_ratio(struct dl_rq *dl_rq);
+
 void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime)
 {
 	raw_spin_lock_init(&dl_b->dl_runtime_lock);
@@ -657,7 +720,7 @@
 	struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
 	struct rq *rq = rq_of_dl_rq(dl_rq);
 
-	WARN_ON(dl_se->dl_boosted);
+	WARN_ON(is_dl_boosted(dl_se));
 	WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline));
 
 	/*
@@ -695,21 +758,20 @@
  * could happen are, typically, a entity voluntarily trying to overcome its
  * runtime, or it just underestimated it during sched_setattr().
  */
-static void replenish_dl_entity(struct sched_dl_entity *dl_se,
-				struct sched_dl_entity *pi_se)
+static void replenish_dl_entity(struct sched_dl_entity *dl_se)
 {
 	struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
 	struct rq *rq = rq_of_dl_rq(dl_rq);
 
-	BUG_ON(pi_se->dl_runtime <= 0);
+	BUG_ON(pi_of(dl_se)->dl_runtime <= 0);
 
 	/*
 	 * This could be the case for a !-dl task that is boosted.
 	 * Just go with full inherited parameters.
 	 */
 	if (dl_se->dl_deadline == 0) {
-		dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
-		dl_se->runtime = pi_se->dl_runtime;
+		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+		dl_se->runtime = pi_of(dl_se)->dl_runtime;
 	}
 
 	if (dl_se->dl_yielded && dl_se->runtime > 0)
@@ -722,8 +784,8 @@
 	 * arbitrary large.
 	 */
 	while (dl_se->runtime <= 0) {
-		dl_se->deadline += pi_se->dl_period;
-		dl_se->runtime += pi_se->dl_runtime;
+		dl_se->deadline += pi_of(dl_se)->dl_period;
+		dl_se->runtime += pi_of(dl_se)->dl_runtime;
 	}
 
 	/*
@@ -737,8 +799,8 @@
 	 */
 	if (dl_time_before(dl_se->deadline, rq_clock(rq))) {
 		printk_deferred_once("sched: DL replenish lagged too much\n");
-		dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
-		dl_se->runtime = pi_se->dl_runtime;
+		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+		dl_se->runtime = pi_of(dl_se)->dl_runtime;
 	}
 
 	if (dl_se->dl_yielded)
@@ -771,8 +833,7 @@
  * task with deadline equal to period this is the same of using
  * dl_period instead of dl_deadline in the equation above.
  */
-static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
-			       struct sched_dl_entity *pi_se, u64 t)
+static bool dl_entity_overflow(struct sched_dl_entity *dl_se, u64 t)
 {
 	u64 left, right;
 
@@ -794,9 +855,9 @@
 	 * of anything below microseconds resolution is actually fiction
 	 * (but still we want to give the user that illusion >;).
 	 */
-	left = (pi_se->dl_deadline >> DL_SCALE) * (dl_se->runtime >> DL_SCALE);
+	left = (pi_of(dl_se)->dl_deadline >> DL_SCALE) * (dl_se->runtime >> DL_SCALE);
 	right = ((dl_se->deadline - t) >> DL_SCALE) *
-		(pi_se->dl_runtime >> DL_SCALE);
+		(pi_of(dl_se)->dl_runtime >> DL_SCALE);
 
 	return dl_time_before(right, left);
 }
@@ -881,24 +942,23 @@
  * Please refer to the comments update_dl_revised_wakeup() function to find
  * more about the Revised CBS rule.
  */
-static void update_dl_entity(struct sched_dl_entity *dl_se,
-			     struct sched_dl_entity *pi_se)
+static void update_dl_entity(struct sched_dl_entity *dl_se)
 {
 	struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
 	struct rq *rq = rq_of_dl_rq(dl_rq);
 
 	if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
-	    dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
+	    dl_entity_overflow(dl_se, rq_clock(rq))) {
 
 		if (unlikely(!dl_is_implicit(dl_se) &&
 			     !dl_time_before(dl_se->deadline, rq_clock(rq)) &&
-			     !dl_se->dl_boosted)){
+			     !is_dl_boosted(dl_se))) {
 			update_dl_revised_wakeup(dl_se, rq);
 			return;
 		}
 
-		dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
-		dl_se->runtime = pi_se->dl_runtime;
+		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+		dl_se->runtime = pi_of(dl_se)->dl_runtime;
 	}
 }
 
@@ -997,7 +1057,7 @@
 	 * The task might have been boosted by someone else and might be in the
 	 * boosting/deboosting path, its not throttled.
 	 */
-	if (dl_se->dl_boosted)
+	if (is_dl_boosted(dl_se))
 		goto unlock;
 
 	/*
@@ -1025,7 +1085,7 @@
 	 * but do not enqueue -- wait for our wakeup to do that.
 	 */
 	if (!task_on_rq_queued(p)) {
-		replenish_dl_entity(dl_se, dl_se);
+		replenish_dl_entity(dl_se);
 		goto unlock;
 	}
 
@@ -1096,7 +1156,7 @@
  * cannot use the runtime, and so it replenishes the task. This rule
  * works fine for implicit deadline tasks (deadline == period), and the
  * CBS was designed for implicit deadline tasks. However, a task with
- * constrained deadline (deadine < period) might be awakened after the
+ * constrained deadline (deadline < period) might be awakened after the
  * deadline, but before the next period. In this case, replenishing the
  * task would allow it to run for runtime / deadline. As in this case
  * deadline < period, CBS enables a task to run for more than the
@@ -1115,7 +1175,7 @@
 
 	if (dl_time_before(dl_se->deadline, rq_clock(rq)) &&
 	    dl_time_before(rq_clock(rq), dl_next_period(dl_se))) {
-		if (unlikely(dl_se->dl_boosted || !start_dl_timer(p)))
+		if (unlikely(is_dl_boosted(dl_se) || !start_dl_timer(p)))
 			return;
 		dl_se->dl_throttled = 1;
 		if (dl_se->runtime > 0)
@@ -1246,7 +1306,7 @@
 			dl_se->dl_overrun = 1;
 
 		__dequeue_task_dl(rq, curr, 0);
-		if (unlikely(dl_se->dl_boosted || !start_dl_timer(curr)))
+		if (unlikely(is_dl_boosted(dl_se) || !start_dl_timer(curr)))
 			enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH);
 
 		if (!is_leftmost(curr, &rq->dl))
@@ -1440,8 +1500,7 @@
 }
 
 static void
-enqueue_dl_entity(struct sched_dl_entity *dl_se,
-		  struct sched_dl_entity *pi_se, int flags)
+enqueue_dl_entity(struct sched_dl_entity *dl_se, int flags)
 {
 	BUG_ON(on_dl_rq(dl_se));
 
@@ -1452,9 +1511,9 @@
 	 */
 	if (flags & ENQUEUE_WAKEUP) {
 		task_contending(dl_se, flags);
-		update_dl_entity(dl_se, pi_se);
+		update_dl_entity(dl_se);
 	} else if (flags & ENQUEUE_REPLENISH) {
-		replenish_dl_entity(dl_se, pi_se);
+		replenish_dl_entity(dl_se);
 	} else if ((flags & ENQUEUE_RESTORE) &&
 		  dl_time_before(dl_se->deadline,
 				 rq_clock(rq_of_dl_rq(dl_rq_of_se(dl_se))))) {
@@ -1471,28 +1530,40 @@
 
 static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
 {
-	struct task_struct *pi_task = rt_mutex_get_top_task(p);
-	struct sched_dl_entity *pi_se = &p->dl;
-
-	/*
-	 * Use the scheduling parameters of the top pi-waiter task if:
-	 * - we have a top pi-waiter which is a SCHED_DEADLINE task AND
-	 * - our dl_boosted is set (i.e. the pi-waiter's (absolute) deadline is
-	 *   smaller than our deadline OR we are a !SCHED_DEADLINE task getting
-	 *   boosted due to a SCHED_DEADLINE pi-waiter).
-	 * Otherwise we keep our runtime and deadline.
-	 */
-	if (pi_task && dl_prio(pi_task->normal_prio) && p->dl.dl_boosted) {
-		pi_se = &pi_task->dl;
+	if (is_dl_boosted(&p->dl)) {
+		/*
+		 * Because of delays in the detection of the overrun of a
+		 * thread's runtime, it might be the case that a thread
+		 * goes to sleep in a rt mutex with negative runtime. As
+		 * a consequence, the thread will be throttled.
+		 *
+		 * While waiting for the mutex, this thread can also be
+		 * boosted via PI, resulting in a thread that is throttled
+		 * and boosted at the same time.
+		 *
+		 * In this case, the boost overrides the throttle.
+		 */
+		if (p->dl.dl_throttled) {
+			/*
+			 * The replenish timer needs to be canceled. No
+			 * problem if it fires concurrently: boosted threads
+			 * are ignored in dl_task_timer().
+			 */
+			hrtimer_try_to_cancel(&p->dl.dl_timer);
+			p->dl.dl_throttled = 0;
+		}
 	} else if (!dl_prio(p->normal_prio)) {
 		/*
-		 * Special case in which we have a !SCHED_DEADLINE task
-		 * that is going to be deboosted, but exceeds its
-		 * runtime while doing so. No point in replenishing
-		 * it, as it's going to return back to its original
-		 * scheduling class after this.
+		 * Special case in which we have a !SCHED_DEADLINE task that is going
+		 * to be deboosted, but exceeds its runtime while doing so. No point in
+		 * replenishing it, as it's going to return back to its original
+		 * scheduling class after this. If it has been throttled, we need to
+		 * clear the flag, otherwise the task may wake up as throttled after
+		 * being boosted again with no means to replenish the runtime and clear
+		 * the throttle.
 		 */
-		BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH);
+		p->dl.dl_throttled = 0;
+		BUG_ON(!is_dl_boosted(&p->dl) || flags != ENQUEUE_REPLENISH);
 		return;
 	}
 
@@ -1529,7 +1600,7 @@
 		return;
 	}
 
-	enqueue_dl_entity(&p->dl, pi_se, flags);
+	enqueue_dl_entity(&p->dl, flags);
 
 	if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_dl_task(rq, p);
@@ -1602,6 +1673,7 @@
 select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
 {
 	struct task_struct *curr;
+	bool select_rq;
 	struct rq *rq;
 
 	if (sd_flag != SD_BALANCE_WAKE)
@@ -1621,10 +1693,19 @@
 	 * other hand, if it has a shorter deadline, we
 	 * try to make it stay here, it might be important.
 	 */
-	if (unlikely(dl_task(curr)) &&
-	    (curr->nr_cpus_allowed < 2 ||
-	     !dl_entity_preempt(&p->dl, &curr->dl)) &&
-	    (p->nr_cpus_allowed > 1)) {
+	select_rq = unlikely(dl_task(curr)) &&
+		    (curr->nr_cpus_allowed < 2 ||
+		     !dl_entity_preempt(&p->dl, &curr->dl)) &&
+		    p->nr_cpus_allowed > 1;
+
+	/*
+	 * Take the capacity of the CPU into account to
+	 * ensure it fits the requirement of the task.
+	 */
+	if (static_branch_unlikely(&sched_asym_cpucapacity))
+		select_rq |= !dl_task_fits_capacity(p, cpu);
+
+	if (select_rq) {
 		int target = find_later_rq(p);
 
 		if (target != -1 &&
@@ -1774,15 +1855,12 @@
 	return rb_entry(left, struct sched_dl_entity, rb_node);
 }
 
-static struct task_struct *
-pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static struct task_struct *pick_next_task_dl(struct rq *rq)
 {
 	struct sched_dl_entity *dl_se;
 	struct dl_rq *dl_rq = &rq->dl;
 	struct task_struct *p;
 
-	WARN_ON_ONCE(prev || rf);
-
 	if (!sched_dl_runnable(rq))
 		return NULL;
 
@@ -2434,8 +2512,8 @@
 	}
 }
 
-const struct sched_class dl_sched_class = {
-	.next			= &rt_sched_class,
+const struct sched_class dl_sched_class
+	__section("__dl_sched_class") = {
 	.enqueue_task		= enqueue_task_dl,
 	.dequeue_task		= dequeue_task_dl,
 	.yield_task		= yield_task_dl,
@@ -2503,7 +2581,7 @@
 	return ret;
 }
 
-void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)
+static void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)
 {
 	if (global_rt_runtime() == RUNTIME_INF) {
 		dl_rq->bw_ratio = 1 << RATIO_SHIFT;
@@ -2556,11 +2634,12 @@
 int sched_dl_overflow(struct task_struct *p, int policy,
 		      const struct sched_attr *attr)
 {
-	struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
 	u64 period = attr->sched_period ?: attr->sched_deadline;
 	u64 runtime = attr->sched_runtime;
 	u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;
-	int cpus, err = -1;
+	int cpus, err = -1, cpu = task_cpu(p);
+	struct dl_bw *dl_b = dl_bw_of(cpu);
+	unsigned long cap;
 
 	if (attr->sched_flags & SCHED_FLAG_SUGOV)
 		return 0;
@@ -2575,15 +2654,17 @@
 	 * allocated bandwidth of the container.
 	 */
 	raw_spin_lock(&dl_b->lock);
-	cpus = dl_bw_cpus(task_cpu(p));
+	cpus = dl_bw_cpus(cpu);
+	cap = dl_bw_capacity(cpu);
+
 	if (dl_policy(policy) && !task_has_dl_policy(p) &&
-	    !__dl_overflow(dl_b, cpus, 0, new_bw)) {
+	    !__dl_overflow(dl_b, cap, 0, new_bw)) {
 		if (hrtimer_active(&p->dl.inactive_timer))
 			__dl_sub(dl_b, p->dl.dl_bw, cpus);
 		__dl_add(dl_b, new_bw, cpus);
 		err = 0;
 	} else if (dl_policy(policy) && task_has_dl_policy(p) &&
-		   !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {
+		   !__dl_overflow(dl_b, cap, p->dl.dl_bw, new_bw)) {
 		/*
 		 * XXX this is slightly incorrect: when the task
 		 * utilization decreases, we should delay the total
@@ -2641,6 +2722,14 @@
 }
 
 /*
+ * Default limits for DL period; on the top end we guard against small util
+ * tasks still getting rediculous long effective runtimes, on the bottom end we
+ * guard against timer DoS.
+ */
+unsigned int sysctl_sched_dl_period_max = 1 << 22; /* ~4 seconds */
+unsigned int sysctl_sched_dl_period_min = 100;     /* 100 us */
+
+/*
  * This function validates the new parameters of a -deadline task.
  * We ask for the deadline not being zero, and greater or equal
  * than the runtime, as well as the period of being zero or
@@ -2652,6 +2741,8 @@
  */
 bool __checkparam_dl(const struct sched_attr *attr)
 {
+	u64 period, max, min;
+
 	/* special dl tasks don't actually use any parameter */
 	if (attr->sched_flags & SCHED_FLAG_SUGOV)
 		return true;
@@ -2675,12 +2766,21 @@
 	    attr->sched_period & (1ULL << 63))
 		return false;
 
+	period = attr->sched_period;
+	if (!period)
+		period = attr->sched_deadline;
+
 	/* runtime <= deadline <= period (if period != 0) */
-	if ((attr->sched_period != 0 &&
-	     attr->sched_period < attr->sched_deadline) ||
+	if (period < attr->sched_deadline ||
 	    attr->sched_deadline < attr->sched_runtime)
 		return false;
 
+	max = (u64)READ_ONCE(sysctl_sched_dl_period_max) * NSEC_PER_USEC;
+	min = (u64)READ_ONCE(sysctl_sched_dl_period_min) * NSEC_PER_USEC;
+
+	if (period < min || period > max)
+		return false;
+
 	return true;
 }
 
@@ -2698,11 +2798,14 @@
 	dl_se->dl_bw			= 0;
 	dl_se->dl_density		= 0;
 
-	dl_se->dl_boosted		= 0;
 	dl_se->dl_throttled		= 0;
 	dl_se->dl_yielded		= 0;
 	dl_se->dl_non_contending	= 0;
 	dl_se->dl_overrun		= 0;
+
+#ifdef CONFIG_RT_MUTEXES
+	dl_se->pi_se			= dl_se;
+#endif
 }
 
 bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
@@ -2721,19 +2824,19 @@
 #ifdef CONFIG_SMP
 int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed)
 {
+	unsigned long flags, cap;
 	unsigned int dest_cpu;
 	struct dl_bw *dl_b;
 	bool overflow;
-	int cpus, ret;
-	unsigned long flags;
+	int ret;
 
 	dest_cpu = cpumask_any_and(cpu_active_mask, cs_cpus_allowed);
 
 	rcu_read_lock_sched();
 	dl_b = dl_bw_of(dest_cpu);
 	raw_spin_lock_irqsave(&dl_b->lock, flags);
-	cpus = dl_bw_cpus(dest_cpu);
-	overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);
+	cap = dl_bw_capacity(dest_cpu);
+	overflow = __dl_overflow(dl_b, cap, 0, p->dl.dl_bw);
 	if (overflow) {
 		ret = -EBUSY;
 	} else {
@@ -2743,6 +2846,8 @@
 		 * We will free resources in the source root_domain
 		 * later on (see set_cpus_allowed_dl()).
 		 */
+		int cpus = dl_bw_cpus(dest_cpu);
+
 		__dl_add(dl_b, p->dl.dl_bw, cpus);
 		ret = 0;
 	}
@@ -2775,16 +2880,15 @@
 
 bool dl_cpu_busy(unsigned int cpu)
 {
-	unsigned long flags;
+	unsigned long flags, cap;
 	struct dl_bw *dl_b;
 	bool overflow;
-	int cpus;
 
 	rcu_read_lock_sched();
 	dl_b = dl_bw_of(cpu);
 	raw_spin_lock_irqsave(&dl_b->lock, flags);
-	cpus = dl_bw_cpus(cpu);
-	overflow = __dl_overflow(dl_b, cpus, 0, 0);
+	cap = dl_bw_capacity(cpu);
+	overflow = __dl_overflow(dl_b, cap, 0, 0);
 	raw_spin_unlock_irqrestore(&dl_b->lock, flags);
 	rcu_read_unlock_sched();
 
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index faada71..70a5782 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -243,6 +243,60 @@
 	entry->proc_handler = proc_handler;
 }
 
+static int sd_ctl_doflags(struct ctl_table *table, int write,
+			  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	unsigned long flags = *(unsigned long *)table->data;
+	size_t data_size = 0;
+	size_t len = 0;
+	char *tmp, *buf;
+	int idx;
+
+	if (write)
+		return 0;
+
+	for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
+		char *name = sd_flag_debug[idx].name;
+
+		/* Name plus whitespace */
+		data_size += strlen(name) + 1;
+	}
+
+	if (*ppos > data_size) {
+		*lenp = 0;
+		return 0;
+	}
+
+	buf = kcalloc(data_size + 1, sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
+		char *name = sd_flag_debug[idx].name;
+
+		len += snprintf(buf + len, strlen(name) + 2, "%s ", name);
+	}
+
+	tmp = buf + *ppos;
+	len -= *ppos;
+
+	if (len > *lenp)
+		len = *lenp;
+	if (len)
+		memcpy(buffer, tmp, len);
+	if (len < *lenp) {
+		((char *)buffer)[len] = '\n';
+		len++;
+	}
+
+	*lenp = len;
+	*ppos += len;
+
+	kfree(buf);
+
+	return 0;
+}
+
 static struct ctl_table *
 sd_alloc_ctl_domain_table(struct sched_domain *sd)
 {
@@ -256,7 +310,7 @@
 	set_table_entry(&table[2], "busy_factor",	  &sd->busy_factor,	    sizeof(int),  0644, proc_dointvec_minmax);
 	set_table_entry(&table[3], "imbalance_pct",	  &sd->imbalance_pct,	    sizeof(int),  0644, proc_dointvec_minmax);
 	set_table_entry(&table[4], "cache_nice_tries",	  &sd->cache_nice_tries,    sizeof(int),  0644, proc_dointvec_minmax);
-	set_table_entry(&table[5], "flags",		  &sd->flags,		    sizeof(int),  0444, proc_dointvec_minmax);
+	set_table_entry(&table[5], "flags",		  &sd->flags,		    sizeof(int),  0444, sd_ctl_doflags);
 	set_table_entry(&table[6], "max_newidle_lb_cost", &sd->max_newidle_lb_cost, sizeof(long), 0644, proc_doulongvec_minmax);
 	set_table_entry(&table[7], "name",		  sd->name,	       CORENAME_MAX_SIZE, 0444, proc_dostring);
 	/* &table[8] is terminator */
@@ -400,11 +454,10 @@
 	}
 
 	P(se->load.weight);
-	P(se->runnable_weight);
 #ifdef CONFIG_SMP
 	P(se->avg.load_avg);
 	P(se->avg.util_avg);
-	P(se->avg.runnable_load_avg);
+	P(se->avg.runnable_avg);
 #endif
 
 #undef PN_SCHEDSTAT
@@ -457,7 +510,7 @@
 	else
 		SEQ_printf(m, " %c", task_state_to_char(p));
 
-	SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
+	SEQ_printf(m, " %15s %5d %9Ld.%06ld %9Ld %5d ",
 		p->comm, task_pid_nr(p),
 		SPLIT_NS(p->se.vruntime),
 		(long long)(p->nvcsw + p->nivcsw),
@@ -484,10 +537,10 @@
 
 	SEQ_printf(m, "\n");
 	SEQ_printf(m, "runnable tasks:\n");
-	SEQ_printf(m, " S           task   PID         tree-key  switches  prio"
+	SEQ_printf(m, " S            task   PID         tree-key  switches  prio"
 		   "     wait-time             sum-exec        sum-sleep\n");
 	SEQ_printf(m, "-------------------------------------------------------"
-		   "----------------------------------------------------\n");
+		   "------------------------------------------------------\n");
 
 	rcu_read_lock();
 	for_each_process_thread(g, p) {
@@ -543,11 +596,10 @@
 	SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
 	SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
 #ifdef CONFIG_SMP
-	SEQ_printf(m, "  .%-30s: %ld\n", "runnable_weight", cfs_rq->runnable_weight);
 	SEQ_printf(m, "  .%-30s: %lu\n", "load_avg",
 			cfs_rq->avg.load_avg);
-	SEQ_printf(m, "  .%-30s: %lu\n", "runnable_load_avg",
-			cfs_rq->avg.runnable_load_avg);
+	SEQ_printf(m, "  .%-30s: %lu\n", "runnable_avg",
+			cfs_rq->avg.runnable_avg);
 	SEQ_printf(m, "  .%-30s: %lu\n", "util_avg",
 			cfs_rq->avg.util_avg);
 	SEQ_printf(m, "  .%-30s: %u\n", "util_est_enqueued",
@@ -556,8 +608,8 @@
 			cfs_rq->removed.load_avg);
 	SEQ_printf(m, "  .%-30s: %ld\n", "removed.util_avg",
 			cfs_rq->removed.util_avg);
-	SEQ_printf(m, "  .%-30s: %ld\n", "removed.runnable_sum",
-			cfs_rq->removed.runnable_sum);
+	SEQ_printf(m, "  .%-30s: %ld\n", "removed.runnable_avg",
+			cfs_rq->removed.runnable_avg);
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	SEQ_printf(m, "  .%-30s: %lu\n", "tg_load_avg_contrib",
 			cfs_rq->tg_load_avg_contrib);
@@ -658,7 +710,6 @@
 
 	P(nr_running);
 	P(nr_switches);
-	P(nr_load_updates);
 	P(nr_uninterruptible);
 	PN(next_balance);
 	SEQ_printf(m, "  .%-30s: %ld\n", "curr->pid", (long)(task_pid_nr(rq->curr)));
@@ -767,9 +818,16 @@
 	int cpu;
 
 	sched_debug_header(NULL);
-	for_each_online_cpu(cpu)
+	for_each_online_cpu(cpu) {
+		/*
+		 * Need to reset softlockup watchdogs on all CPUs, because
+		 * another CPU might be blocked waiting for us to process
+		 * an IPI or stop_machine.
+		 */
+		touch_nmi_watchdog();
+		touch_all_softlockup_watchdogs();
 		print_cpu(NULL, cpu);
-
+	}
 }
 
 /*
@@ -827,10 +885,13 @@
 
 __initcall(init_sched_debug_procfs);
 
-#define __P(F)	SEQ_printf(m, "%-45s:%21Ld\n",	     #F, (long long)F)
-#define   P(F)	SEQ_printf(m, "%-45s:%21Ld\n",	     #F, (long long)p->F)
-#define __PN(F)	SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
-#define   PN(F)	SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
+#define __PS(S, F) SEQ_printf(m, "%-45s:%21Ld\n", S, (long long)(F))
+#define __P(F) __PS(#F, F)
+#define   P(F) __PS(#F, p->F)
+#define   PM(F, M) __PS(#F, p->F & (M))
+#define __PSN(S, F) SEQ_printf(m, "%-45s:%14Ld.%06ld\n", S, SPLIT_NS((long long)(F)))
+#define __PN(F) __PSN(#F, F)
+#define   PN(F) __PSN(#F, p->F)
 
 
 #ifdef CONFIG_NUMA_BALANCING
@@ -879,18 +940,9 @@
 	SEQ_printf(m,
 		"---------------------------------------------------------"
 		"----------\n");
-#define __P(F) \
-	SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
-#define P(F) \
-	SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
-#define P_SCHEDSTAT(F) \
-	SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)schedstat_val(p->F))
-#define __PN(F) \
-	SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
-#define PN(F) \
-	SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
-#define PN_SCHEDSTAT(F) \
-	SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)schedstat_val(p->F)))
+
+#define P_SCHEDSTAT(F)  __PS(#F, schedstat_val(p->F))
+#define PN_SCHEDSTAT(F) __PSN(#F, schedstat_val(p->F))
 
 	PN(se.exec_start);
 	PN(se.vruntime);
@@ -950,23 +1002,26 @@
 	}
 
 	__P(nr_switches);
-	SEQ_printf(m, "%-45s:%21Ld\n",
-		   "nr_voluntary_switches", (long long)p->nvcsw);
-	SEQ_printf(m, "%-45s:%21Ld\n",
-		   "nr_involuntary_switches", (long long)p->nivcsw);
+	__PS("nr_voluntary_switches", p->nvcsw);
+	__PS("nr_involuntary_switches", p->nivcsw);
 
 	P(se.load.weight);
-	P(se.runnable_weight);
 #ifdef CONFIG_SMP
 	P(se.avg.load_sum);
-	P(se.avg.runnable_load_sum);
+	P(se.avg.runnable_sum);
 	P(se.avg.util_sum);
 	P(se.avg.load_avg);
-	P(se.avg.runnable_load_avg);
+	P(se.avg.runnable_avg);
 	P(se.avg.util_avg);
 	P(se.avg.last_update_time);
 	P(se.avg.util_est.ewma);
-	P(se.avg.util_est.enqueued);
+	PM(se.avg.util_est.enqueued, ~UTIL_AVG_UNCHANGED);
+#endif
+#ifdef CONFIG_UCLAMP_TASK
+	__PS("uclamp.min", p->uclamp_req[UCLAMP_MIN].value);
+	__PS("uclamp.max", p->uclamp_req[UCLAMP_MAX].value);
+	__PS("effective uclamp.min", uclamp_eff_value(p, UCLAMP_MIN));
+	__PS("effective uclamp.max", uclamp_eff_value(p, UCLAMP_MAX));
 #endif
 	P(policy);
 	P(prio);
@@ -975,11 +1030,7 @@
 		P(dl.deadline);
 	}
 #undef PN_SCHEDSTAT
-#undef PN
-#undef __PN
 #undef P_SCHEDSTAT
-#undef P
-#undef __P
 
 	{
 		unsigned int this_cpu = raw_smp_processor_id();
@@ -987,8 +1038,7 @@
 
 		t0 = cpu_clock(this_cpu);
 		t1 = cpu_clock(this_cpu);
-		SEQ_printf(m, "%-45s:%21Ld\n",
-			   "clock-delta", (long long)(t1-t0));
+		__PS("clock-delta", t1-t0);
 	}
 
 	sched_show_numa(p, m);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 87d9fad..acd9833 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -22,8 +22,6 @@
  */
 #include "sched.h"
 
-#include <trace/events/sched.h>
-
 /*
  * Targeted preemption latency for CPU-bound tasks:
  *
@@ -86,6 +84,19 @@
 
 const_debug unsigned int sysctl_sched_migration_cost	= 500000UL;
 
+int sched_thermal_decay_shift;
+static int __init setup_sched_thermal_decay_shift(char *str)
+{
+	int _shift = 0;
+
+	if (kstrtoint(str, 0, &_shift))
+		pr_warn("Unable to set scheduler thermal pressure decay shift parameter\n");
+
+	sched_thermal_decay_shift = clamp(_shift, 0, 10);
+	return 1;
+}
+__setup("sched_thermal_decay_shift=", setup_sched_thermal_decay_shift);
+
 #ifdef CONFIG_SMP
 /*
  * For asym packing, by default the lower numbered CPU has higher priority.
@@ -178,7 +189,7 @@
 #undef SET_SYSCTL
 }
 
-void sched_init_granularity(void)
+void __init sched_init_granularity(void)
 {
 	update_sysctl();
 }
@@ -229,8 +240,7 @@
 		}
 	}
 
-	/* hint to use a 32x32->64 mul */
-	fact = (u64)(u32)fact * lw->inv_weight;
+	fact = mul_u32_u32(fact, lw->inv_weight);
 
 	while (fact >> 32) {
 		fact >>= 1;
@@ -633,8 +643,7 @@
  */
 
 int sched_proc_update_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 	unsigned int factor = get_update_sysctl_factor();
@@ -691,7 +700,13 @@
  */
 static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-	u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq);
+	unsigned int nr_running = cfs_rq->nr_running;
+	u64 slice;
+
+	if (sched_feat(ALT_PERIOD))
+		nr_running = rq_of(cfs_rq)->cfs.h_nr_running;
+
+	slice = __sched_period(nr_running + !se->on_rq);
 
 	for_each_sched_entity(se) {
 		struct load_weight *load;
@@ -708,6 +723,10 @@
 		}
 		slice = __calc_delta(slice, se->load.weight, load);
 	}
+
+	if (sched_feat(BASE_SLICE))
+		slice = max(slice, (u64)sysctl_sched_min_granularity);
+
 	return slice;
 }
 
@@ -742,9 +761,7 @@
 	 * nothing has been attached to the task group yet.
 	 */
 	if (entity_is_task(se))
-		sa->runnable_load_avg = sa->load_avg = scale_load_down(se->load.weight);
-
-	se->runnable_weight = se->load.weight;
+		sa->load_avg = scale_load_down(se->load.weight);
 
 	/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */
 }
@@ -797,12 +814,14 @@
 		}
 	}
 
+	sa->runnable_avg = sa->util_avg;
+
 	if (p->sched_class != &fair_sched_class) {
 		/*
 		 * For !fair tasks do:
 		 *
 		update_cfs_rq_load_avg(now, cfs_rq);
-		attach_entity_load_avg(cfs_rq, se, 0);
+		attach_entity_load_avg(cfs_rq, se);
 		switched_from_fair(rq, p);
 		 *
 		 * such that the next switched_to_fair() has the
@@ -822,7 +841,7 @@
 void post_init_entity_util_avg(struct task_struct *p)
 {
 }
-static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
+static void update_tg_load_avg(struct cfs_rq *cfs_rq)
 {
 }
 #endif /* CONFIG_SMP */
@@ -1082,7 +1101,7 @@
 	 * more by CPU use than by memory faults.
 	 */
 	unsigned long *faults_cpu;
-	unsigned long faults[0];
+	unsigned long faults[];
 };
 
 /*
@@ -1474,31 +1493,52 @@
 	       group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4;
 }
 
-static unsigned long cpu_runnable_load(struct rq *rq);
+/*
+ * 'numa_type' describes the node at the moment of load balancing.
+ */
+enum numa_type {
+	/* The node has spare capacity that can be used to run more tasks.  */
+	node_has_spare = 0,
+	/*
+	 * The node is fully used and the tasks don't compete for more CPU
+	 * cycles. Nevertheless, some tasks might wait before running.
+	 */
+	node_fully_busy,
+	/*
+	 * The node is overloaded and can't provide expected CPU cycles to all
+	 * tasks.
+	 */
+	node_overloaded
+};
 
 /* Cached statistics for all CPUs within a node */
 struct numa_stats {
 	unsigned long load;
-
+	unsigned long runnable;
+	unsigned long util;
 	/* Total compute capacity of CPUs on a node */
 	unsigned long compute_capacity;
+	unsigned int nr_running;
+	unsigned int weight;
+	enum numa_type node_type;
+	int idle_cpu;
 };
 
-/*
- * XXX borrowed from update_sg_lb_stats
- */
-static void update_numa_stats(struct numa_stats *ns, int nid)
+static inline bool is_core_idle(int cpu)
 {
-	int cpu;
+#ifdef CONFIG_SCHED_SMT
+	int sibling;
 
-	memset(ns, 0, sizeof(*ns));
-	for_each_cpu(cpu, cpumask_of_node(nid)) {
-		struct rq *rq = cpu_rq(cpu);
+	for_each_cpu(sibling, cpu_smt_mask(cpu)) {
+		if (cpu == sibling)
+			continue;
 
-		ns->load += cpu_runnable_load(rq);
-		ns->compute_capacity += capacity_of(cpu);
+		if (!idle_cpu(sibling))
+			return false;
 	}
+#endif
 
+	return true;
 }
 
 struct task_numa_env {
@@ -1517,20 +1557,132 @@
 	int best_cpu;
 };
 
+static unsigned long cpu_load(struct rq *rq);
+static unsigned long cpu_runnable(struct rq *rq);
+static unsigned long cpu_util(int cpu);
+static inline long adjust_numa_imbalance(int imbalance, int nr_running);
+
+static inline enum
+numa_type numa_classify(unsigned int imbalance_pct,
+			 struct numa_stats *ns)
+{
+	if ((ns->nr_running > ns->weight) &&
+	    (((ns->compute_capacity * 100) < (ns->util * imbalance_pct)) ||
+	     ((ns->compute_capacity * imbalance_pct) < (ns->runnable * 100))))
+		return node_overloaded;
+
+	if ((ns->nr_running < ns->weight) ||
+	    (((ns->compute_capacity * 100) > (ns->util * imbalance_pct)) &&
+	     ((ns->compute_capacity * imbalance_pct) > (ns->runnable * 100))))
+		return node_has_spare;
+
+	return node_fully_busy;
+}
+
+#ifdef CONFIG_SCHED_SMT
+/* Forward declarations of select_idle_sibling helpers */
+static inline bool test_idle_cores(int cpu, bool def);
+static inline int numa_idle_core(int idle_core, int cpu)
+{
+	if (!static_branch_likely(&sched_smt_present) ||
+	    idle_core >= 0 || !test_idle_cores(cpu, false))
+		return idle_core;
+
+	/*
+	 * Prefer cores instead of packing HT siblings
+	 * and triggering future load balancing.
+	 */
+	if (is_core_idle(cpu))
+		idle_core = cpu;
+
+	return idle_core;
+}
+#else
+static inline int numa_idle_core(int idle_core, int cpu)
+{
+	return idle_core;
+}
+#endif
+
+/*
+ * Gather all necessary information to make NUMA balancing placement
+ * decisions that are compatible with standard load balancer. This
+ * borrows code and logic from update_sg_lb_stats but sharing a
+ * common implementation is impractical.
+ */
+static void update_numa_stats(struct task_numa_env *env,
+			      struct numa_stats *ns, int nid,
+			      bool find_idle)
+{
+	int cpu, idle_core = -1;
+
+	memset(ns, 0, sizeof(*ns));
+	ns->idle_cpu = -1;
+
+	rcu_read_lock();
+	for_each_cpu(cpu, cpumask_of_node(nid)) {
+		struct rq *rq = cpu_rq(cpu);
+
+		ns->load += cpu_load(rq);
+		ns->runnable += cpu_runnable(rq);
+		ns->util += cpu_util(cpu);
+		ns->nr_running += rq->cfs.h_nr_running;
+		ns->compute_capacity += capacity_of(cpu);
+
+		if (find_idle && !rq->nr_running && idle_cpu(cpu)) {
+			if (READ_ONCE(rq->numa_migrate_on) ||
+			    !cpumask_test_cpu(cpu, env->p->cpus_ptr))
+				continue;
+
+			if (ns->idle_cpu == -1)
+				ns->idle_cpu = cpu;
+
+			idle_core = numa_idle_core(idle_core, cpu);
+		}
+	}
+	rcu_read_unlock();
+
+	ns->weight = cpumask_weight(cpumask_of_node(nid));
+
+	ns->node_type = numa_classify(env->imbalance_pct, ns);
+
+	if (idle_core >= 0)
+		ns->idle_cpu = idle_core;
+}
+
 static void task_numa_assign(struct task_numa_env *env,
 			     struct task_struct *p, long imp)
 {
 	struct rq *rq = cpu_rq(env->dst_cpu);
 
-	/* Bail out if run-queue part of active NUMA balance. */
-	if (xchg(&rq->numa_migrate_on, 1))
-		return;
+	/* Check if run-queue part of active NUMA balance. */
+	if (env->best_cpu != env->dst_cpu && xchg(&rq->numa_migrate_on, 1)) {
+		int cpu;
+		int start = env->dst_cpu;
 
+		/* Find alternative idle CPU. */
+		for_each_cpu_wrap(cpu, cpumask_of_node(env->dst_nid), start) {
+			if (cpu == env->best_cpu || !idle_cpu(cpu) ||
+			    !cpumask_test_cpu(cpu, env->p->cpus_ptr)) {
+				continue;
+			}
+
+			env->dst_cpu = cpu;
+			rq = cpu_rq(env->dst_cpu);
+			if (!xchg(&rq->numa_migrate_on, 1))
+				goto assign;
+		}
+
+		/* Failed to find an alternative idle CPU */
+		return;
+	}
+
+assign:
 	/*
 	 * Clear previous best_cpu/rq numa-migrate flag, since task now
 	 * found a better CPU to move/swap.
 	 */
-	if (env->best_cpu != -1) {
+	if (env->best_cpu != -1 && env->best_cpu != env->dst_cpu) {
 		rq = cpu_rq(env->best_cpu);
 		WRITE_ONCE(rq->numa_migrate_on, 0);
 	}
@@ -1586,7 +1738,7 @@
  * into account that it might be best if task running on the dst_cpu should
  * be exchanged with the source task
  */
-static void task_numa_compare(struct task_numa_env *env,
+static bool task_numa_compare(struct task_numa_env *env,
 			      long taskimp, long groupimp, bool maymove)
 {
 	struct numa_group *cur_ng, *p_ng = deref_curr_numa_group(env->p);
@@ -1597,9 +1749,10 @@
 	int dist = env->dist;
 	long moveimp = imp;
 	long load;
+	bool stopsearch = false;
 
 	if (READ_ONCE(dst_rq->numa_migrate_on))
-		return;
+		return false;
 
 	rcu_read_lock();
 	cur = rcu_dereference(dst_rq->curr);
@@ -1610,8 +1763,10 @@
 	 * Because we have preemption enabled we can get migrated around and
 	 * end try selecting ourselves (current == env->p) as a swap candidate.
 	 */
-	if (cur == env->p)
+	if (cur == env->p) {
+		stopsearch = true;
 		goto unlock;
+	}
 
 	if (!cur) {
 		if (maymove && moveimp >= env->best_imp)
@@ -1620,18 +1775,27 @@
 			goto unlock;
 	}
 
+	/* Skip this swap candidate if cannot move to the source cpu. */
+	if (!cpumask_test_cpu(env->src_cpu, cur->cpus_ptr))
+		goto unlock;
+
+	/*
+	 * Skip this swap candidate if it is not moving to its preferred
+	 * node and the best task is.
+	 */
+	if (env->best_task &&
+	    env->best_task->numa_preferred_nid == env->src_nid &&
+	    cur->numa_preferred_nid != env->src_nid) {
+		goto unlock;
+	}
+
 	/*
 	 * "imp" is the fault differential for the source task between the
 	 * source and destination node. Calculate the total differential for
 	 * the source task and potential destination task. The more negative
 	 * the value is, the more remote accesses that would be expected to
 	 * be incurred if the tasks were swapped.
-	 */
-	/* Skip this swap candidate if cannot move to the source cpu */
-	if (!cpumask_test_cpu(env->src_cpu, cur->cpus_ptr))
-		goto unlock;
-
-	/*
+	 *
 	 * If dst and source tasks are in the same NUMA group, or not
 	 * in any group then look only at task weights.
 	 */
@@ -1658,6 +1822,19 @@
 			       task_weight(cur, env->dst_nid, dist);
 	}
 
+	/* Discourage picking a task already on its preferred node */
+	if (cur->numa_preferred_nid == env->dst_nid)
+		imp -= imp / 16;
+
+	/*
+	 * Encourage picking a task that moves to its preferred node.
+	 * This potentially makes imp larger than it's maximum of
+	 * 1998 (see SMALLIMP and task_weight for why) but in this
+	 * case, it does not matter.
+	 */
+	if (cur->numa_preferred_nid == env->src_nid)
+		imp += imp / 8;
+
 	if (maymove && moveimp > imp && moveimp > env->best_imp) {
 		imp = moveimp;
 		cur = NULL;
@@ -1665,6 +1842,15 @@
 	}
 
 	/*
+	 * Prefer swapping with a task moving to its preferred node over a
+	 * task that is not.
+	 */
+	if (env->best_task && cur->numa_preferred_nid == env->src_nid &&
+	    env->best_task->numa_preferred_nid != env->src_nid) {
+		goto assign;
+	}
+
+	/*
 	 * If the NUMA importance is less than SMALLIMP,
 	 * task migration might only result in ping pong
 	 * of tasks and also hurt performance due to cache
@@ -1687,42 +1873,95 @@
 		goto unlock;
 
 assign:
-	/*
-	 * One idle CPU per node is evaluated for a task numa move.
-	 * Call select_idle_sibling to maybe find a better one.
-	 */
+	/* Evaluate an idle CPU for a task numa move. */
 	if (!cur) {
+		int cpu = env->dst_stats.idle_cpu;
+
+		/* Nothing cached so current CPU went idle since the search. */
+		if (cpu < 0)
+			cpu = env->dst_cpu;
+
 		/*
-		 * select_idle_siblings() uses an per-CPU cpumask that
-		 * can be used from IRQ context.
+		 * If the CPU is no longer truly idle and the previous best CPU
+		 * is, keep using it.
 		 */
-		local_irq_disable();
-		env->dst_cpu = select_idle_sibling(env->p, env->src_cpu,
-						   env->dst_cpu);
-		local_irq_enable();
+		if (!idle_cpu(cpu) && env->best_cpu >= 0 &&
+		    idle_cpu(env->best_cpu)) {
+			cpu = env->best_cpu;
+		}
+
+		env->dst_cpu = cpu;
 	}
 
 	task_numa_assign(env, cur, imp);
+
+	/*
+	 * If a move to idle is allowed because there is capacity or load
+	 * balance improves then stop the search. While a better swap
+	 * candidate may exist, a search is not free.
+	 */
+	if (maymove && !cur && env->best_cpu >= 0 && idle_cpu(env->best_cpu))
+		stopsearch = true;
+
+	/*
+	 * If a swap candidate must be identified and the current best task
+	 * moves its preferred node then stop the search.
+	 */
+	if (!maymove && env->best_task &&
+	    env->best_task->numa_preferred_nid == env->src_nid) {
+		stopsearch = true;
+	}
 unlock:
 	rcu_read_unlock();
+
+	return stopsearch;
 }
 
 static void task_numa_find_cpu(struct task_numa_env *env,
 				long taskimp, long groupimp)
 {
-	long src_load, dst_load, load;
 	bool maymove = false;
 	int cpu;
 
-	load = task_h_load(env->p);
-	dst_load = env->dst_stats.load + load;
-	src_load = env->src_stats.load - load;
-
 	/*
-	 * If the improvement from just moving env->p direction is better
-	 * than swapping tasks around, check if a move is possible.
+	 * If dst node has spare capacity, then check if there is an
+	 * imbalance that would be overruled by the load balancer.
 	 */
-	maymove = !load_too_imbalanced(src_load, dst_load, env);
+	if (env->dst_stats.node_type == node_has_spare) {
+		unsigned int imbalance;
+		int src_running, dst_running;
+
+		/*
+		 * Would movement cause an imbalance? Note that if src has
+		 * more running tasks that the imbalance is ignored as the
+		 * move improves the imbalance from the perspective of the
+		 * CPU load balancer.
+		 * */
+		src_running = env->src_stats.nr_running - 1;
+		dst_running = env->dst_stats.nr_running + 1;
+		imbalance = max(0, dst_running - src_running);
+		imbalance = adjust_numa_imbalance(imbalance, dst_running);
+
+		/* Use idle CPU if there is no imbalance */
+		if (!imbalance) {
+			maymove = true;
+			if (env->dst_stats.idle_cpu >= 0) {
+				env->dst_cpu = env->dst_stats.idle_cpu;
+				task_numa_assign(env, NULL, 0);
+				return;
+			}
+		}
+	} else {
+		long src_load, dst_load, load;
+		/*
+		 * If the improvement from just moving env->p direction is better
+		 * than swapping tasks around, check if a move is possible.
+		 */
+		load = task_h_load(env->p);
+		dst_load = env->dst_stats.load + load;
+		src_load = env->src_stats.load - load;
+		maymove = !load_too_imbalanced(src_load, dst_load, env);
+	}
 
 	for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) {
 		/* Skip this CPU if the source task cannot migrate */
@@ -1730,7 +1969,8 @@
 			continue;
 
 		env->dst_cpu = cpu;
-		task_numa_compare(env, taskimp, groupimp, maymove);
+		if (task_numa_compare(env, taskimp, groupimp, maymove))
+			break;
 	}
 }
 
@@ -1784,10 +2024,10 @@
 	dist = env.dist = node_distance(env.src_nid, env.dst_nid);
 	taskweight = task_weight(p, env.src_nid, dist);
 	groupweight = group_weight(p, env.src_nid, dist);
-	update_numa_stats(&env.src_stats, env.src_nid);
+	update_numa_stats(&env, &env.src_stats, env.src_nid, false);
 	taskimp = task_weight(p, env.dst_nid, dist) - taskweight;
 	groupimp = group_weight(p, env.dst_nid, dist) - groupweight;
-	update_numa_stats(&env.dst_stats, env.dst_nid);
+	update_numa_stats(&env, &env.dst_stats, env.dst_nid, true);
 
 	/* Try to find a spot on the preferred nid. */
 	task_numa_find_cpu(&env, taskimp, groupimp);
@@ -1820,7 +2060,7 @@
 
 			env.dist = dist;
 			env.dst_nid = nid;
-			update_numa_stats(&env.dst_stats, env.dst_nid);
+			update_numa_stats(&env, &env.dst_stats, env.dst_nid, true);
 			task_numa_find_cpu(&env, taskimp, groupimp);
 		}
 	}
@@ -1844,15 +2084,17 @@
 	}
 
 	/* No better CPU than the current one was found. */
-	if (env.best_cpu == -1)
+	if (env.best_cpu == -1) {
+		trace_sched_stick_numa(p, env.src_cpu, NULL, -1);
 		return -EAGAIN;
+	}
 
 	best_rq = cpu_rq(env.best_cpu);
 	if (env.best_task == NULL) {
 		ret = migrate_task_to(p, env.best_cpu);
 		WRITE_ONCE(best_rq->numa_migrate_on, 0);
 		if (ret != 0)
-			trace_sched_stick_numa(p, env.src_cpu, env.best_cpu);
+			trace_sched_stick_numa(p, env.src_cpu, NULL, env.best_cpu);
 		return ret;
 	}
 
@@ -1860,7 +2102,7 @@
 	WRITE_ONCE(best_rq->numa_migrate_on, 0);
 
 	if (ret != 0)
-		trace_sched_stick_numa(p, env.src_cpu, task_cpu(env.best_task));
+		trace_sched_stick_numa(p, env.src_cpu, env.best_task, env.best_cpu);
 	put_task_struct(env.best_task);
 	return ret;
 }
@@ -2541,7 +2783,7 @@
 		return;
 
 
-	if (!down_read_trylock(&mm->mmap_sem))
+	if (!mmap_read_trylock(mm))
 		return;
 	vma = find_vma(mm, start);
 	if (!vma) {
@@ -2569,7 +2811,7 @@
 		 * Skip inaccessible VMAs to avoid any confusion between
 		 * PROT_NONE and NUMA hinting ptes
 		 */
-		if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
+		if (!vma_is_accessible(vma))
 			continue;
 
 		do {
@@ -2609,7 +2851,7 @@
 		mm->numa_scan_offset = start;
 	else
 		reset_ptenuma_scan(p);
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	/*
 	 * Make sure tasks use at least 32x as much time to run other code
@@ -2696,7 +2938,7 @@
 		curr->node_stamp += period;
 
 		if (!time_before(jiffies, curr->mm->numa_next_scan))
-			task_work_add(curr, work, true);
+			task_work_add(curr, work, TWA_RESUME);
 	}
 }
 
@@ -2831,25 +3073,6 @@
 
 #ifdef CONFIG_SMP
 static inline void
-enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-	cfs_rq->runnable_weight += se->runnable_weight;
-
-	cfs_rq->avg.runnable_load_avg += se->avg.runnable_load_avg;
-	cfs_rq->avg.runnable_load_sum += se_runnable(se) * se->avg.runnable_load_sum;
-}
-
-static inline void
-dequeue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-	cfs_rq->runnable_weight -= se->runnable_weight;
-
-	sub_positive(&cfs_rq->avg.runnable_load_avg, se->avg.runnable_load_avg);
-	sub_positive(&cfs_rq->avg.runnable_load_sum,
-		     se_runnable(se) * se->avg.runnable_load_sum);
-}
-
-static inline void
 enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 	cfs_rq->avg.load_avg += se->avg.load_avg;
@@ -2864,45 +3087,36 @@
 }
 #else
 static inline void
-enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
-static inline void
-dequeue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
-static inline void
 enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
 static inline void
 dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
 #endif
 
 static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
-			    unsigned long weight, unsigned long runnable)
+			    unsigned long weight)
 {
 	if (se->on_rq) {
 		/* commit outstanding execution time */
 		if (cfs_rq->curr == se)
 			update_curr(cfs_rq);
-		account_entity_dequeue(cfs_rq, se);
-		dequeue_runnable_load_avg(cfs_rq, se);
+		update_load_sub(&cfs_rq->load, se->load.weight);
 	}
 	dequeue_load_avg(cfs_rq, se);
 
-	se->runnable_weight = runnable;
 	update_load_set(&se->load, weight);
 
 #ifdef CONFIG_SMP
 	do {
-		u32 divider = LOAD_AVG_MAX - 1024 + se->avg.period_contrib;
+		u32 divider = get_pelt_divider(&se->avg);
 
 		se->avg.load_avg = div_u64(se_weight(se) * se->avg.load_sum, divider);
-		se->avg.runnable_load_avg =
-			div_u64(se_runnable(se) * se->avg.runnable_load_sum, divider);
 	} while (0);
 #endif
 
 	enqueue_load_avg(cfs_rq, se);
-	if (se->on_rq) {
-		account_entity_enqueue(cfs_rq, se);
-		enqueue_runnable_load_avg(cfs_rq, se);
-	}
+	if (se->on_rq)
+		update_load_add(&cfs_rq->load, se->load.weight);
+
 }
 
 void reweight_task(struct task_struct *p, int prio)
@@ -2912,7 +3126,7 @@
 	struct load_weight *load = &se->load;
 	unsigned long weight = scale_load(sched_prio_to_weight[prio]);
 
-	reweight_entity(cfs_rq, se, weight, weight);
+	reweight_entity(cfs_rq, se, weight);
 	load->inv_weight = sched_prio_to_wmult[prio];
 }
 
@@ -3024,50 +3238,6 @@
 	 */
 	return clamp_t(long, shares, MIN_SHARES, tg_shares);
 }
-
-/*
- * This calculates the effective runnable weight for a group entity based on
- * the group entity weight calculated above.
- *
- * Because of the above approximation (2), our group entity weight is
- * an load_avg based ratio (3). This means that it includes blocked load and
- * does not represent the runnable weight.
- *
- * Approximate the group entity's runnable weight per ratio from the group
- * runqueue:
- *
- *					     grq->avg.runnable_load_avg
- *   ge->runnable_weight = ge->load.weight * -------------------------- (7)
- *						 grq->avg.load_avg
- *
- * However, analogous to above, since the avg numbers are slow, this leads to
- * transients in the from-idle case. Instead we use:
- *
- *   ge->runnable_weight = ge->load.weight *
- *
- *		max(grq->avg.runnable_load_avg, grq->runnable_weight)
- *		-----------------------------------------------------	(8)
- *		      max(grq->avg.load_avg, grq->load.weight)
- *
- * Where these max() serve both to use the 'instant' values to fix the slow
- * from-idle and avoid the /0 on to-idle, similar to (6).
- */
-static long calc_group_runnable(struct cfs_rq *cfs_rq, long shares)
-{
-	long runnable, load_avg;
-
-	load_avg = max(cfs_rq->avg.load_avg,
-		       scale_load_down(cfs_rq->load.weight));
-
-	runnable = max(cfs_rq->avg.runnable_load_avg,
-		       scale_load_down(cfs_rq->runnable_weight));
-
-	runnable *= shares;
-	if (load_avg)
-		runnable /= load_avg;
-
-	return clamp_t(long, runnable, MIN_SHARES, shares);
-}
 #endif /* CONFIG_SMP */
 
 static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
@@ -3079,7 +3249,7 @@
 static void update_cfs_group(struct sched_entity *se)
 {
 	struct cfs_rq *gcfs_rq = group_cfs_rq(se);
-	long shares, runnable;
+	long shares;
 
 	if (!gcfs_rq)
 		return;
@@ -3088,16 +3258,15 @@
 		return;
 
 #ifndef CONFIG_SMP
-	runnable = shares = READ_ONCE(gcfs_rq->tg->shares);
+	shares = READ_ONCE(gcfs_rq->tg->shares);
 
 	if (likely(se->load.weight == shares))
 		return;
 #else
 	shares   = calc_group_shares(gcfs_rq);
-	runnable = calc_group_runnable(gcfs_rq, shares);
 #endif
 
-	reweight_entity(cfs_rq_of(se), se, shares, runnable);
+	reweight_entity(cfs_rq_of(se), se, shares);
 }
 
 #else /* CONFIG_FAIR_GROUP_SCHED */
@@ -3110,7 +3279,7 @@
 {
 	struct rq *rq = rq_of(cfs_rq);
 
-	if (&rq->cfs == cfs_rq || (flags & SCHED_CPUFREQ_MIGRATION)) {
+	if (&rq->cfs == cfs_rq) {
 		/*
 		 * There are a few boundary cases this might miss but it should
 		 * get called often enough that that should (hopefully) not be
@@ -3134,7 +3303,6 @@
 /**
  * update_tg_load_avg - update the tg's load avg
  * @cfs_rq: the cfs_rq whose avg changed
- * @force: update regardless of how small the difference
  *
  * This function 'ensures': tg->load_avg := \Sum tg->cfs_rq[]->avg.load.
  * However, because tg->load_avg is a global value there are performance
@@ -3146,7 +3314,7 @@
  *
  * Updating tg's load_avg is necessary before update_cfs_share().
  */
-static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
+static inline void update_tg_load_avg(struct cfs_rq *cfs_rq)
 {
 	long delta = cfs_rq->avg.load_avg - cfs_rq->tg_load_avg_contrib;
 
@@ -3156,7 +3324,7 @@
 	if (cfs_rq->tg == &root_task_group)
 		return;
 
-	if (force || abs(delta) > cfs_rq->tg_load_avg_contrib / 64) {
+	if (abs(delta) > cfs_rq->tg_load_avg_contrib / 64) {
 		atomic_long_add(delta, &cfs_rq->tg->load_avg);
 		cfs_rq->tg_load_avg_contrib = cfs_rq->avg.load_avg;
 	}
@@ -3211,7 +3379,6 @@
 	se->avg.last_update_time = n_last_update_time;
 }
 
-
 /*
  * When on migration a sched_entity joins/leaves the PELT hierarchy, we need to
  * propagate its contribution. The key to this propagation is the invariant
@@ -3222,11 +3389,11 @@
  * _IFF_ we look at the pure running and runnable sums. Because they
  * represent the very same entity, just at different points in the hierarchy.
  *
- * Per the above update_tg_cfs_util() is trivial and simply copies the running
- * sum over (but still wrong, because the group entity and group rq do not have
- * their PELT windows aligned).
+ * Per the above update_tg_cfs_util() and update_tg_cfs_runnable() are trivial
+ * and simply copies the running/runnable sum over (but still wrong, because
+ * the group entity and group rq do not have their PELT windows aligned).
  *
- * However, update_tg_cfs_runnable() is more complex. So we have:
+ * However, update_tg_cfs_load() is more complex. So we have:
  *
  *   ge->avg.load_avg = ge->load.weight * ge->avg.runnable_avg		(2)
  *
@@ -3279,53 +3446,82 @@
  * XXX: only do this for the part of runnable > running ?
  *
  */
-
 static inline void
 update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
 {
 	long delta = gcfs_rq->avg.util_avg - se->avg.util_avg;
+	u32 divider;
 
 	/* Nothing to update */
 	if (!delta)
 		return;
 
 	/*
-	 * The relation between sum and avg is:
-	 *
-	 *   LOAD_AVG_MAX - 1024 + sa->period_contrib
-	 *
-	 * however, the PELT windows are not aligned between grq and gse.
+	 * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
+	 * See ___update_load_avg() for details.
 	 */
+	divider = get_pelt_divider(&cfs_rq->avg);
 
 	/* Set new sched_entity's utilization */
 	se->avg.util_avg = gcfs_rq->avg.util_avg;
-	se->avg.util_sum = se->avg.util_avg * LOAD_AVG_MAX;
+	se->avg.util_sum = se->avg.util_avg * divider;
 
 	/* Update parent cfs_rq utilization */
 	add_positive(&cfs_rq->avg.util_avg, delta);
-	cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * LOAD_AVG_MAX;
+	cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * divider;
 }
 
 static inline void
 update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
 {
-	long delta_avg, running_sum, runnable_sum = gcfs_rq->prop_runnable_sum;
-	unsigned long runnable_load_avg, load_avg;
-	u64 runnable_load_sum, load_sum = 0;
-	s64 delta_sum;
+	long delta = gcfs_rq->avg.runnable_avg - se->avg.runnable_avg;
+	u32 divider;
+
+	/* Nothing to update */
+	if (!delta)
+		return;
+
+	/*
+	 * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
+	 * See ___update_load_avg() for details.
+	 */
+	divider = get_pelt_divider(&cfs_rq->avg);
+
+	/* Set new sched_entity's runnable */
+	se->avg.runnable_avg = gcfs_rq->avg.runnable_avg;
+	se->avg.runnable_sum = se->avg.runnable_avg * divider;
+
+	/* Update parent cfs_rq runnable */
+	add_positive(&cfs_rq->avg.runnable_avg, delta);
+	cfs_rq->avg.runnable_sum = cfs_rq->avg.runnable_avg * divider;
+}
+
+static inline void
+update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
+{
+	long delta, running_sum, runnable_sum = gcfs_rq->prop_runnable_sum;
+	unsigned long load_avg;
+	u64 load_sum = 0;
+	u32 divider;
 
 	if (!runnable_sum)
 		return;
 
 	gcfs_rq->prop_runnable_sum = 0;
 
+	/*
+	 * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
+	 * See ___update_load_avg() for details.
+	 */
+	divider = get_pelt_divider(&cfs_rq->avg);
+
 	if (runnable_sum >= 0) {
 		/*
 		 * Add runnable; clip at LOAD_AVG_MAX. Reflects that until
 		 * the CPU is saturated running == runnable.
 		 */
 		runnable_sum += se->avg.load_sum;
-		runnable_sum = min(runnable_sum, (long)LOAD_AVG_MAX);
+		runnable_sum = min_t(long, runnable_sum, divider);
 	} else {
 		/*
 		 * Estimate the new unweighted runnable_sum of the gcfs_rq by
@@ -3350,28 +3546,15 @@
 	runnable_sum = max(runnable_sum, running_sum);
 
 	load_sum = (s64)se_weight(se) * runnable_sum;
-	load_avg = div_s64(load_sum, LOAD_AVG_MAX);
+	load_avg = div_s64(load_sum, divider);
 
-	delta_sum = load_sum - (s64)se_weight(se) * se->avg.load_sum;
-	delta_avg = load_avg - se->avg.load_avg;
+	delta = load_avg - se->avg.load_avg;
 
 	se->avg.load_sum = runnable_sum;
 	se->avg.load_avg = load_avg;
-	add_positive(&cfs_rq->avg.load_avg, delta_avg);
-	add_positive(&cfs_rq->avg.load_sum, delta_sum);
 
-	runnable_load_sum = (s64)se_runnable(se) * runnable_sum;
-	runnable_load_avg = div_s64(runnable_load_sum, LOAD_AVG_MAX);
-	delta_sum = runnable_load_sum - se_weight(se) * se->avg.runnable_load_sum;
-	delta_avg = runnable_load_avg - se->avg.runnable_load_avg;
-
-	se->avg.runnable_load_sum = runnable_sum;
-	se->avg.runnable_load_avg = runnable_load_avg;
-
-	if (se->on_rq) {
-		add_positive(&cfs_rq->avg.runnable_load_avg, delta_avg);
-		add_positive(&cfs_rq->avg.runnable_load_sum, delta_sum);
-	}
+	add_positive(&cfs_rq->avg.load_avg, delta);
+	cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * divider;
 }
 
 static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum)
@@ -3400,6 +3583,7 @@
 
 	update_tg_cfs_util(cfs_rq, se, gcfs_rq);
 	update_tg_cfs_runnable(cfs_rq, se, gcfs_rq);
+	update_tg_cfs_load(cfs_rq, se, gcfs_rq);
 
 	trace_pelt_cfs_tp(cfs_rq);
 	trace_pelt_se_tp(se);
@@ -3439,7 +3623,7 @@
 
 #else /* CONFIG_FAIR_GROUP_SCHED */
 
-static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) {}
+static inline void update_tg_load_avg(struct cfs_rq *cfs_rq) {}
 
 static inline int propagate_entity_load_avg(struct sched_entity *se)
 {
@@ -3469,30 +3653,51 @@
 static inline int
 update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 {
-	unsigned long removed_load = 0, removed_util = 0, removed_runnable_sum = 0;
+	unsigned long removed_load = 0, removed_util = 0, removed_runnable = 0;
 	struct sched_avg *sa = &cfs_rq->avg;
 	int decayed = 0;
 
 	if (cfs_rq->removed.nr) {
 		unsigned long r;
-		u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib;
+		u32 divider = get_pelt_divider(&cfs_rq->avg);
 
 		raw_spin_lock(&cfs_rq->removed.lock);
 		swap(cfs_rq->removed.util_avg, removed_util);
 		swap(cfs_rq->removed.load_avg, removed_load);
-		swap(cfs_rq->removed.runnable_sum, removed_runnable_sum);
+		swap(cfs_rq->removed.runnable_avg, removed_runnable);
 		cfs_rq->removed.nr = 0;
 		raw_spin_unlock(&cfs_rq->removed.lock);
 
 		r = removed_load;
 		sub_positive(&sa->load_avg, r);
-		sub_positive(&sa->load_sum, r * divider);
+		sa->load_sum = sa->load_avg * divider;
 
 		r = removed_util;
 		sub_positive(&sa->util_avg, r);
 		sub_positive(&sa->util_sum, r * divider);
+		/*
+		 * Because of rounding, se->util_sum might ends up being +1 more than
+		 * cfs->util_sum. Although this is not a problem by itself, detaching
+		 * a lot of tasks with the rounding problem between 2 updates of
+		 * util_avg (~1ms) can make cfs->util_sum becoming null whereas
+		 * cfs_util_avg is not.
+		 * Check that util_sum is still above its lower bound for the new
+		 * util_avg. Given that period_contrib might have moved since the last
+		 * sync, we are only sure that util_sum must be above or equal to
+		 *    util_avg * minimum possible divider
+		 */
+		sa->util_sum = max_t(u32, sa->util_sum, sa->util_avg * PELT_MIN_DIVIDER);
 
-		add_tg_cfs_propagate(cfs_rq, -(long)removed_runnable_sum);
+		r = removed_runnable;
+		sub_positive(&sa->runnable_avg, r);
+		sa->runnable_sum = sa->runnable_avg * divider;
+
+		/*
+		 * removed_runnable is the unweighted version of removed_load so we
+		 * can use it to estimate removed_load_sum.
+		 */
+		add_tg_cfs_propagate(cfs_rq,
+			-(long)(removed_runnable * divider) >> SCHED_CAPACITY_SHIFT);
 
 		decayed = 1;
 	}
@@ -3511,14 +3716,17 @@
  * attach_entity_load_avg - attach this entity to its cfs_rq load avg
  * @cfs_rq: cfs_rq to attach to
  * @se: sched_entity to attach
- * @flags: migration hints
  *
  * Must call update_cfs_rq_load_avg() before this, since we rely on
  * cfs_rq->avg.last_update_time being current.
  */
-static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
+static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-	u32 divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib;
+	/*
+	 * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
+	 * See ___update_load_avg() for details.
+	 */
+	u32 divider = get_pelt_divider(&cfs_rq->avg);
 
 	/*
 	 * When we attach the @se to the @cfs_rq, we must align the decay
@@ -3538,21 +3746,23 @@
 	 */
 	se->avg.util_sum = se->avg.util_avg * divider;
 
+	se->avg.runnable_sum = se->avg.runnable_avg * divider;
+
 	se->avg.load_sum = divider;
 	if (se_weight(se)) {
 		se->avg.load_sum =
 			div_u64(se->avg.load_avg * se->avg.load_sum, se_weight(se));
 	}
 
-	se->avg.runnable_load_sum = se->avg.load_sum;
-
 	enqueue_load_avg(cfs_rq, se);
 	cfs_rq->avg.util_avg += se->avg.util_avg;
 	cfs_rq->avg.util_sum += se->avg.util_sum;
+	cfs_rq->avg.runnable_avg += se->avg.runnable_avg;
+	cfs_rq->avg.runnable_sum += se->avg.runnable_sum;
 
 	add_tg_cfs_propagate(cfs_rq, se->avg.load_sum);
 
-	cfs_rq_util_change(cfs_rq, flags);
+	cfs_rq_util_change(cfs_rq, 0);
 
 	trace_pelt_cfs_tp(cfs_rq);
 }
@@ -3567,9 +3777,17 @@
  */
 static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
+	/*
+	 * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
+	 * See ___update_load_avg() for details.
+	 */
+	u32 divider = get_pelt_divider(&cfs_rq->avg);
+
 	dequeue_load_avg(cfs_rq, se);
 	sub_positive(&cfs_rq->avg.util_avg, se->avg.util_avg);
-	sub_positive(&cfs_rq->avg.util_sum, se->avg.util_sum);
+	cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * divider;
+	sub_positive(&cfs_rq->avg.runnable_avg, se->avg.runnable_avg);
+	cfs_rq->avg.runnable_sum = cfs_rq->avg.runnable_avg * divider;
 
 	add_tg_cfs_propagate(cfs_rq, -se->avg.load_sum);
 
@@ -3610,14 +3828,14 @@
 		 *
 		 * IOW we're enqueueing a task on a new CPU.
 		 */
-		attach_entity_load_avg(cfs_rq, se, SCHED_CPUFREQ_MIGRATION);
-		update_tg_load_avg(cfs_rq, 0);
+		attach_entity_load_avg(cfs_rq, se);
+		update_tg_load_avg(cfs_rq);
 
 	} else if (decayed) {
 		cfs_rq_util_change(cfs_rq, 0);
 
 		if (flags & UPDATE_TG)
-			update_tg_load_avg(cfs_rq, 0);
+			update_tg_load_avg(cfs_rq);
 	}
 }
 
@@ -3676,13 +3894,13 @@
 	++cfs_rq->removed.nr;
 	cfs_rq->removed.util_avg	+= se->avg.util_avg;
 	cfs_rq->removed.load_avg	+= se->avg.load_avg;
-	cfs_rq->removed.runnable_sum	+= se->avg.load_sum; /* == runnable_sum */
+	cfs_rq->removed.runnable_avg	+= se->avg.runnable_avg;
 	raw_spin_unlock_irqrestore(&cfs_rq->removed.lock, flags);
 }
 
-static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq)
+static inline unsigned long cfs_rq_runnable_avg(struct cfs_rq *cfs_rq)
 {
-	return cfs_rq->avg.runnable_load_avg;
+	return cfs_rq->avg.runnable_avg;
 }
 
 static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq)
@@ -3690,6 +3908,8 @@
 	return cfs_rq->avg.load_avg;
 }
 
+static int newidle_balance(struct rq *this_rq, struct rq_flags *rf);
+
 static inline unsigned long task_util(struct task_struct *p)
 {
 	return READ_ONCE(p->se.avg.util_avg);
@@ -3699,7 +3919,7 @@
 {
 	struct util_est ue = READ_ONCE(p->se.avg.util_est);
 
-	return (max(ue.ewma, ue.enqueued) | UTIL_AVG_UNCHANGED);
+	return max(ue.ewma, (ue.enqueued & ~UTIL_AVG_UNCHANGED));
 }
 
 static inline unsigned long task_util_est(struct task_struct *p)
@@ -3707,6 +3927,20 @@
 	return max(task_util(p), _task_util_est(p));
 }
 
+#ifdef CONFIG_UCLAMP_TASK
+static inline unsigned long uclamp_task_util(struct task_struct *p)
+{
+	return clamp(task_util_est(p),
+		     uclamp_eff_value(p, UCLAMP_MIN),
+		     uclamp_eff_value(p, UCLAMP_MAX));
+}
+#else
+static inline unsigned long uclamp_task_util(struct task_struct *p)
+{
+	return task_util_est(p);
+}
+#endif
+
 static inline void util_est_enqueue(struct cfs_rq *cfs_rq,
 				    struct task_struct *p)
 {
@@ -3719,8 +3953,28 @@
 	enqueued  = cfs_rq->avg.util_est.enqueued;
 	enqueued += _task_util_est(p);
 	WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
+
+	trace_sched_util_est_cfs_tp(cfs_rq);
 }
 
+static inline void util_est_dequeue(struct cfs_rq *cfs_rq,
+				    struct task_struct *p)
+{
+	unsigned int enqueued;
+
+	if (!sched_feat(UTIL_EST))
+		return;
+
+	/* Update root cfs_rq's estimated utilization */
+	enqueued  = cfs_rq->avg.util_est.enqueued;
+	enqueued -= min_t(unsigned int, enqueued, _task_util_est(p));
+	WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
+
+	trace_sched_util_est_cfs_tp(cfs_rq);
+}
+
+#define UTIL_EST_MARGIN (SCHED_CAPACITY_SCALE / 100)
+
 /*
  * Check if a (signed) value is within a specified (unsigned) margin,
  * based on the observation that:
@@ -3734,21 +3988,16 @@
 	return ((unsigned int)(value + margin - 1) < (2 * margin - 1));
 }
 
-static void
-util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
+static inline void util_est_update(struct cfs_rq *cfs_rq,
+				   struct task_struct *p,
+				   bool task_sleep)
 {
-	long last_ewma_diff;
+	long last_ewma_diff, last_enqueued_diff;
 	struct util_est ue;
-	int cpu;
 
 	if (!sched_feat(UTIL_EST))
 		return;
 
-	/* Update root cfs_rq's estimated utilization */
-	ue.enqueued  = cfs_rq->avg.util_est.enqueued;
-	ue.enqueued -= min_t(unsigned int, ue.enqueued, _task_util_est(p));
-	WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued);
-
 	/*
 	 * Skip update of task's estimated utilization when the task has not
 	 * yet completed an activation, e.g. being migrated.
@@ -3764,21 +4013,38 @@
 	if (ue.enqueued & UTIL_AVG_UNCHANGED)
 		return;
 
+	last_enqueued_diff = ue.enqueued;
+
 	/*
-	 * Skip update of task's estimated utilization when its EWMA is
+	 * Reset EWMA on utilization increases, the moving average is used only
+	 * to smooth utilization decreases.
+	 */
+	ue.enqueued = task_util(p);
+	if (sched_feat(UTIL_EST_FASTUP)) {
+		if (ue.ewma < ue.enqueued) {
+			ue.ewma = ue.enqueued;
+			goto done;
+		}
+	}
+
+	/*
+	 * Skip update of task's estimated utilization when its members are
 	 * already ~1% close to its last activation value.
 	 */
-	ue.enqueued = (task_util(p) | UTIL_AVG_UNCHANGED);
 	last_ewma_diff = ue.enqueued - ue.ewma;
-	if (within_margin(last_ewma_diff, (SCHED_CAPACITY_SCALE / 100)))
+	last_enqueued_diff -= ue.enqueued;
+	if (within_margin(last_ewma_diff, UTIL_EST_MARGIN)) {
+		if (!within_margin(last_enqueued_diff, UTIL_EST_MARGIN))
+			goto done;
+
 		return;
+	}
 
 	/*
 	 * To avoid overestimation of actual task utilization, skip updates if
 	 * we cannot grant there is idle time in this CPU.
 	 */
-	cpu = cpu_of(rq_of(cfs_rq));
-	if (task_util(p) > capacity_orig_of(cpu))
+	if (task_util(p) > capacity_orig_of(cpu_of(rq_of(cfs_rq))))
 		return;
 
 	/*
@@ -3801,12 +4067,16 @@
 	ue.ewma <<= UTIL_EST_WEIGHT_SHIFT;
 	ue.ewma  += last_ewma_diff;
 	ue.ewma >>= UTIL_EST_WEIGHT_SHIFT;
+done:
+	ue.enqueued |= UTIL_AVG_UNCHANGED;
 	WRITE_ONCE(p->se.avg.util_est, ue);
+
+	trace_sched_util_est_se_tp(&p->se);
 }
 
 static inline int task_fits_capacity(struct task_struct *p, long capacity)
 {
-	return fits_capacity(task_util_est(p), capacity);
+	return fits_capacity(uclamp_task_util(p), capacity);
 }
 
 static inline void update_misfit_status(struct task_struct *p, struct rq *rq)
@@ -3845,11 +4115,11 @@
 static inline void remove_entity_load_avg(struct sched_entity *se) {}
 
 static inline void
-attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) {}
+attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
 static inline void
 detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
 
-static inline int idle_balance(struct rq *rq, struct rq_flags *rf)
+static inline int newidle_balance(struct rq *rq, struct rq_flags *rf)
 {
 	return 0;
 }
@@ -3858,8 +4128,11 @@
 util_est_enqueue(struct cfs_rq *cfs_rq, struct task_struct *p) {}
 
 static inline void
-util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p,
-		 bool task_sleep) {}
+util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p) {}
+
+static inline void
+util_est_update(struct cfs_rq *cfs_rq, struct task_struct *p,
+		bool task_sleep) {}
 static inline void update_misfit_status(struct task_struct *p, struct rq *rq) {}
 
 #endif /* CONFIG_SMP */
@@ -3996,8 +4269,8 @@
 	 *   - Add its new weight to cfs_rq->load.weight
 	 */
 	update_load_avg(cfs_rq, se, UPDATE_TG | DO_ATTACH);
+	se_update_runnable(se);
 	update_cfs_group(se);
-	enqueue_runnable_load_avg(cfs_rq, se);
 	account_entity_enqueue(cfs_rq, se);
 
 	if (flags & ENQUEUE_WAKEUP)
@@ -4086,7 +4359,7 @@
 	 *     of its group cfs_rq.
 	 */
 	update_load_avg(cfs_rq, se, UPDATE_TG);
-	dequeue_runnable_load_avg(cfs_rq, se);
+	se_update_runnable(se);
 
 	update_stats_dequeue(cfs_rq, se, flags);
 
@@ -4238,17 +4511,17 @@
 			se = second;
 	}
 
-	/*
-	 * Prefer last buddy, try to return the CPU to a preempted task.
-	 */
-	if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1)
-		se = cfs_rq->last;
-
-	/*
-	 * Someone really wants this to run. If it's not unfair, run it.
-	 */
-	if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1)
+	if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1) {
+		/*
+		 * Someone really wants this to run. If it's not unfair, run it.
+		 */
 		se = cfs_rq->next;
+	} else if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1) {
+		/*
+		 * Prefer last buddy, try to return the CPU to a preempted task.
+		 */
+		se = cfs_rq->last;
+	}
 
 	clear_buddies(cfs_rq, se);
 
@@ -4554,8 +4827,13 @@
 		if (!se->on_rq)
 			break;
 
-		if (dequeue)
+		if (dequeue) {
 			dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP);
+		} else {
+			update_load_avg(qcfs_rq, se, 0);
+			se_update_runnable(se);
+		}
+
 		qcfs_rq->h_nr_running -= task_delta;
 		qcfs_rq->idle_h_nr_running -= idle_task_delta;
 
@@ -4618,6 +4896,9 @@
 	for_each_sched_entity(se) {
 		cfs_rq = cfs_rq_of(se);
 
+		update_load_avg(cfs_rq, se, UPDATE_TG);
+		se_update_runnable(se);
+
 		cfs_rq->h_nr_running += task_delta;
 		cfs_rq->idle_h_nr_running += idle_task_delta;
 
@@ -4657,11 +4938,10 @@
 		resched_curr(rq);
 }
 
-static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b, u64 remaining)
+static void distribute_cfs_runtime(struct cfs_bandwidth *cfs_b)
 {
 	struct cfs_rq *cfs_rq;
-	u64 runtime;
-	u64 starting_runtime = remaining;
+	u64 runtime, remaining = 1;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(cfs_rq, &cfs_b->throttled_cfs_rq,
@@ -4676,10 +4956,13 @@
 		/* By the above check, this should never be true */
 		SCHED_WARN_ON(cfs_rq->runtime_remaining > 0);
 
+		raw_spin_lock(&cfs_b->lock);
 		runtime = -cfs_rq->runtime_remaining + 1;
-		if (runtime > remaining)
-			runtime = remaining;
-		remaining -= runtime;
+		if (runtime > cfs_b->runtime)
+			runtime = cfs_b->runtime;
+		cfs_b->runtime -= runtime;
+		remaining = cfs_b->runtime;
+		raw_spin_unlock(&cfs_b->lock);
 
 		cfs_rq->runtime_remaining += runtime;
 
@@ -4694,8 +4977,6 @@
 			break;
 	}
 	rcu_read_unlock();
-
-	return starting_runtime - remaining;
 }
 
 /*
@@ -4706,7 +4987,6 @@
  */
 static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, unsigned long flags)
 {
-	u64 runtime;
 	int throttled;
 
 	/* no need to continue the timer with no bandwidth constraint */
@@ -4735,24 +5015,15 @@
 	cfs_b->nr_throttled += overrun;
 
 	/*
-	 * This check is repeated as we are holding onto the new bandwidth while
-	 * we unthrottle. This can potentially race with an unthrottled group
-	 * trying to acquire new bandwidth from the global pool. This can result
-	 * in us over-using our runtime if it is all used during this loop, but
-	 * only by limited amounts in that extreme case.
+	 * This check is repeated as we release cfs_b->lock while we unthrottle.
 	 */
-	while (throttled && cfs_b->runtime > 0 && !cfs_b->distribute_running) {
-		runtime = cfs_b->runtime;
-		cfs_b->distribute_running = 1;
+	while (throttled && cfs_b->runtime > 0) {
 		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 		/* we can't nest cfs_b->lock while distributing bandwidth */
-		runtime = distribute_cfs_runtime(cfs_b, runtime);
+		distribute_cfs_runtime(cfs_b);
 		raw_spin_lock_irqsave(&cfs_b->lock, flags);
 
-		cfs_b->distribute_running = 0;
 		throttled = !list_empty(&cfs_b->throttled_cfs_rq);
-
-		lsub_positive(&cfs_b->runtime, runtime);
 	}
 
 	/*
@@ -4865,10 +5136,6 @@
 	/* confirm we're still not at a refresh boundary */
 	raw_spin_lock_irqsave(&cfs_b->lock, flags);
 	cfs_b->slack_started = false;
-	if (cfs_b->distribute_running) {
-		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
-		return;
-	}
 
 	if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) {
 		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
@@ -4878,26 +5145,21 @@
 	if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice)
 		runtime = cfs_b->runtime;
 
-	if (runtime)
-		cfs_b->distribute_running = 1;
-
 	raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 
 	if (!runtime)
 		return;
 
-	runtime = distribute_cfs_runtime(cfs_b, runtime);
+	distribute_cfs_runtime(cfs_b);
 
 	raw_spin_lock_irqsave(&cfs_b->lock, flags);
-	lsub_positive(&cfs_b->runtime, runtime);
-	cfs_b->distribute_running = 0;
 	raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 }
 
 /*
  * When a group wakes up we want to make sure that its quota is not already
  * expired/exceeded, otherwise it may be allowed to steal additional ticks of
- * runtime as update_curr() throttling can not not trigger until it's on-rq.
+ * runtime as update_curr() throttling can not trigger until it's on-rq.
  */
 static void check_enqueue_throttle(struct cfs_rq *cfs_rq)
 {
@@ -5032,7 +5294,6 @@
 	cfs_b->period_timer.function = sched_cfs_period_timer;
 	hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	cfs_b->slack_timer.function = sched_cfs_slack_timer;
-	cfs_b->distribute_running = 0;
 	cfs_b->slack_started = false;
 }
 
@@ -5237,6 +5498,20 @@
 static inline void update_overutilized_status(struct rq *rq) { }
 #endif
 
+/* Runqueue only has SCHED_IDLE tasks enqueued */
+static int sched_idle_rq(struct rq *rq)
+{
+	return unlikely(rq->nr_running == rq->cfs.idle_h_nr_running &&
+			rq->nr_running);
+}
+
+#ifdef CONFIG_SMP
+static int sched_idle_cpu(int cpu)
+{
+	return sched_idle_rq(cpu_rq(cpu));
+}
+#endif
+
 /*
  * The enqueue_task method is called before nr_running is
  * increased. Here we update the fair scheduling stats and
@@ -5286,6 +5561,7 @@
 		cfs_rq = cfs_rq_of(se);
 
 		update_load_avg(cfs_rq, se, UPDATE_TG);
+		se_update_runnable(se);
 		update_cfs_group(se);
 
 		cfs_rq->h_nr_running++;
@@ -5303,28 +5579,27 @@
                        list_add_leaf_cfs_rq(cfs_rq);
 	}
 
+	/* At this point se is NULL and we are at root level*/
+	add_nr_running(rq, 1);
+
+	/*
+	 * Since new tasks are assigned an initial util_avg equal to
+	 * half of the spare capacity of their CPU, tiny tasks have the
+	 * ability to cross the overutilized threshold, which will
+	 * result in the load balancer ruining all the task placement
+	 * done by EAS. As a way to mitigate that effect, do not account
+	 * for the first enqueue operation of new tasks during the
+	 * overutilized flag detection.
+	 *
+	 * A better way of solving this problem would be to wait for
+	 * the PELT signals of tasks to converge before taking them
+	 * into account, but that is not straightforward to implement,
+	 * and the following generally works well enough in practice.
+	 */
+	if (!task_new)
+		update_overutilized_status(rq);
+
 enqueue_throttle:
-	if (!se) {
-		add_nr_running(rq, 1);
-		/*
-		 * Since new tasks are assigned an initial util_avg equal to
-		 * half of the spare capacity of their CPU, tiny tasks have the
-		 * ability to cross the overutilized threshold, which will
-		 * result in the load balancer ruining all the task placement
-		 * done by EAS. As a way to mitigate that effect, do not account
-		 * for the first enqueue operation of new tasks during the
-		 * overutilized flag detection.
-		 *
-		 * A better way of solving this problem would be to wait for
-		 * the PELT signals of tasks to converge before taking them
-		 * into account, but that is not straightforward to implement,
-		 * and the following generally works well enough in practice.
-		 */
-		if (!task_new)
-			update_overutilized_status(rq);
-
-	}
-
 	if (cfs_bandwidth_used()) {
 		/*
 		 * When bandwidth control is enabled; the cfs_rq_throttled()
@@ -5358,6 +5633,9 @@
 	struct sched_entity *se = &p->se;
 	int task_sleep = flags & DEQUEUE_SLEEP;
 	int idle_h_nr_running = task_has_idle_policy(p);
+	bool was_sched_idle = sched_idle_rq(rq);
+
+	util_est_dequeue(&rq->cfs, p);
 
 	for_each_sched_entity(se) {
 		cfs_rq = cfs_rq_of(se);
@@ -5389,6 +5667,7 @@
 		cfs_rq = cfs_rq_of(se);
 
 		update_load_avg(cfs_rq, se, UPDATE_TG);
+		se_update_runnable(se);
 		update_cfs_group(se);
 
 		cfs_rq->h_nr_running--;
@@ -5400,11 +5679,15 @@
 
 	}
 
-dequeue_throttle:
-	if (!se)
-		sub_nr_running(rq, 1);
+	/* At this point se is NULL and we are at root level*/
+	sub_nr_running(rq, 1);
 
-	util_est_dequeue(&rq->cfs, p, task_sleep);
+	/* balance early to pull high priority tasks */
+	if (unlikely(!was_sched_idle && sched_idle_rq(rq)))
+		rq->next_balance = jiffies;
+
+dequeue_throttle:
+	util_est_update(&rq->cfs, p, task_sleep);
 	hrtick_update(rq);
 }
 
@@ -5426,18 +5709,63 @@
 
 #endif /* CONFIG_NO_HZ_COMMON */
 
-/* CPU only has SCHED_IDLE tasks enqueued */
-static int sched_idle_cpu(int cpu)
+static unsigned long cpu_load(struct rq *rq)
 {
-	struct rq *rq = cpu_rq(cpu);
-
-	return unlikely(rq->nr_running == rq->cfs.idle_h_nr_running &&
-			rq->nr_running);
+	return cfs_rq_load_avg(&rq->cfs);
 }
 
-static unsigned long cpu_runnable_load(struct rq *rq)
+/*
+ * cpu_load_without - compute CPU load without any contributions from *p
+ * @cpu: the CPU which load is requested
+ * @p: the task which load should be discounted
+ *
+ * The load of a CPU is defined by the load of tasks currently enqueued on that
+ * CPU as well as tasks which are currently sleeping after an execution on that
+ * CPU.
+ *
+ * This method returns the load of the specified CPU by discounting the load of
+ * the specified task, whenever the task is currently contributing to the CPU
+ * load.
+ */
+static unsigned long cpu_load_without(struct rq *rq, struct task_struct *p)
 {
-	return cfs_rq_runnable_load_avg(&rq->cfs);
+	struct cfs_rq *cfs_rq;
+	unsigned int load;
+
+	/* Task has no contribution or is new */
+	if (cpu_of(rq) != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time))
+		return cpu_load(rq);
+
+	cfs_rq = &rq->cfs;
+	load = READ_ONCE(cfs_rq->avg.load_avg);
+
+	/* Discount task's util from CPU's util */
+	lsub_positive(&load, task_h_load(p));
+
+	return load;
+}
+
+static unsigned long cpu_runnable(struct rq *rq)
+{
+	return cfs_rq_runnable_avg(&rq->cfs);
+}
+
+static unsigned long cpu_runnable_without(struct rq *rq, struct task_struct *p)
+{
+	struct cfs_rq *cfs_rq;
+	unsigned int runnable;
+
+	/* Task has no contribution or is new */
+	if (cpu_of(rq) != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time))
+		return cpu_runnable(rq);
+
+	cfs_rq = &rq->cfs;
+	runnable = READ_ONCE(cfs_rq->avg.runnable_avg);
+
+	/* Discount task's runnable from CPU's runnable */
+	lsub_positive(&runnable, p->se.avg.runnable_avg);
+
+	return runnable;
 }
 
 static unsigned long capacity_of(int cpu)
@@ -5445,18 +5773,6 @@
 	return cpu_rq(cpu)->cpu_capacity;
 }
 
-static unsigned long cpu_avg_load_per_task(int cpu)
-{
-	struct rq *rq = cpu_rq(cpu);
-	unsigned long nr_running = READ_ONCE(rq->cfs.h_nr_running);
-	unsigned long load_avg = cpu_runnable_load(rq);
-
-	if (nr_running)
-		return load_avg / nr_running;
-
-	return 0;
-}
-
 static void record_wakee(struct task_struct *p)
 {
 	/*
@@ -5495,7 +5811,7 @@
 {
 	unsigned int master = current->wakee_flips;
 	unsigned int slave = p->wakee_flips;
-	int factor = this_cpu_read(sd_llc_size);
+	int factor = __this_cpu_read(sd_llc_size);
 
 	if (master < slave)
 		swap(master, slave);
@@ -5547,7 +5863,7 @@
 	s64 this_eff_load, prev_eff_load;
 	unsigned long task_load;
 
-	this_eff_load = cpu_runnable_load(cpu_rq(this_cpu));
+	this_eff_load = cpu_load(cpu_rq(this_cpu));
 
 	if (sync) {
 		unsigned long current_load = task_h_load(current);
@@ -5565,7 +5881,7 @@
 		this_eff_load *= 100;
 	this_eff_load *= capacity_of(prev_cpu);
 
-	prev_eff_load = cpu_runnable_load(cpu_rq(prev_cpu));
+	prev_eff_load = cpu_load(cpu_rq(prev_cpu));
 	prev_eff_load -= task_load;
 	if (sched_feat(WA_BIAS))
 		prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2;
@@ -5603,149 +5919,8 @@
 	return target;
 }
 
-static unsigned long cpu_util_without(int cpu, struct task_struct *p);
-
-static unsigned long capacity_spare_without(int cpu, struct task_struct *p)
-{
-	return max_t(long, capacity_of(cpu) - cpu_util_without(cpu, p), 0);
-}
-
-/*
- * find_idlest_group finds and returns the least busy CPU group within the
- * domain.
- *
- * Assumes p is allowed on at least one CPU in sd.
- */
 static struct sched_group *
-find_idlest_group(struct sched_domain *sd, struct task_struct *p,
-		  int this_cpu, int sd_flag)
-{
-	struct sched_group *idlest = NULL, *group = sd->groups;
-	struct sched_group *most_spare_sg = NULL;
-	unsigned long min_runnable_load = ULONG_MAX;
-	unsigned long this_runnable_load = ULONG_MAX;
-	unsigned long min_avg_load = ULONG_MAX, this_avg_load = ULONG_MAX;
-	unsigned long most_spare = 0, this_spare = 0;
-	int imbalance_scale = 100 + (sd->imbalance_pct-100)/2;
-	unsigned long imbalance = scale_load_down(NICE_0_LOAD) *
-				(sd->imbalance_pct-100) / 100;
-
-	do {
-		unsigned long load, avg_load, runnable_load;
-		unsigned long spare_cap, max_spare_cap;
-		int local_group;
-		int i;
-
-		/* Skip over this group if it has no CPUs allowed */
-		if (!cpumask_intersects(sched_group_span(group),
-					p->cpus_ptr))
-			continue;
-
-		local_group = cpumask_test_cpu(this_cpu,
-					       sched_group_span(group));
-
-		/*
-		 * Tally up the load of all CPUs in the group and find
-		 * the group containing the CPU with most spare capacity.
-		 */
-		avg_load = 0;
-		runnable_load = 0;
-		max_spare_cap = 0;
-
-		for_each_cpu(i, sched_group_span(group)) {
-			load = cpu_runnable_load(cpu_rq(i));
-			runnable_load += load;
-
-			avg_load += cfs_rq_load_avg(&cpu_rq(i)->cfs);
-
-			spare_cap = capacity_spare_without(i, p);
-
-			if (spare_cap > max_spare_cap)
-				max_spare_cap = spare_cap;
-		}
-
-		/* Adjust by relative CPU capacity of the group */
-		avg_load = (avg_load * SCHED_CAPACITY_SCALE) /
-					group->sgc->capacity;
-		runnable_load = (runnable_load * SCHED_CAPACITY_SCALE) /
-					group->sgc->capacity;
-
-		if (local_group) {
-			this_runnable_load = runnable_load;
-			this_avg_load = avg_load;
-			this_spare = max_spare_cap;
-		} else {
-			if (min_runnable_load > (runnable_load + imbalance)) {
-				/*
-				 * The runnable load is significantly smaller
-				 * so we can pick this new CPU:
-				 */
-				min_runnable_load = runnable_load;
-				min_avg_load = avg_load;
-				idlest = group;
-			} else if ((runnable_load < (min_runnable_load + imbalance)) &&
-				   (100*min_avg_load > imbalance_scale*avg_load)) {
-				/*
-				 * The runnable loads are close so take the
-				 * blocked load into account through avg_load:
-				 */
-				min_avg_load = avg_load;
-				idlest = group;
-			}
-
-			if (most_spare < max_spare_cap) {
-				most_spare = max_spare_cap;
-				most_spare_sg = group;
-			}
-		}
-	} while (group = group->next, group != sd->groups);
-
-	/*
-	 * The cross-over point between using spare capacity or least load
-	 * is too conservative for high utilization tasks on partially
-	 * utilized systems if we require spare_capacity > task_util(p),
-	 * so we allow for some task stuffing by using
-	 * spare_capacity > task_util(p)/2.
-	 *
-	 * Spare capacity can't be used for fork because the utilization has
-	 * not been set yet, we must first select a rq to compute the initial
-	 * utilization.
-	 */
-	if (sd_flag & SD_BALANCE_FORK)
-		goto skip_spare;
-
-	if (this_spare > task_util(p) / 2 &&
-	    imbalance_scale*this_spare > 100*most_spare)
-		return NULL;
-
-	if (most_spare > task_util(p) / 2)
-		return most_spare_sg;
-
-skip_spare:
-	if (!idlest)
-		return NULL;
-
-	/*
-	 * When comparing groups across NUMA domains, it's possible for the
-	 * local domain to be very lightly loaded relative to the remote
-	 * domains but "imbalance" skews the comparison making remote CPUs
-	 * look much more favourable. When considering cross-domain, add
-	 * imbalance to the runnable load on the remote node and consider
-	 * staying local.
-	 */
-	if ((sd->flags & SD_NUMA) &&
-	    min_runnable_load + imbalance >= this_runnable_load)
-		return NULL;
-
-	if (min_runnable_load > (this_runnable_load + imbalance))
-		return NULL;
-
-	if ((this_runnable_load < (min_runnable_load + imbalance)) &&
-	     (100*this_avg_load < imbalance_scale*min_avg_load))
-		return NULL;
-
-	return idlest;
-}
+find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu);
 
 /*
  * find_idlest_group_cpu - find the idlest CPU among the CPUs in the group.
@@ -5757,7 +5932,7 @@
 	unsigned int min_exit_latency = UINT_MAX;
 	u64 latest_idle_timestamp = 0;
 	int least_loaded_cpu = this_cpu;
-	int shallowest_idle_cpu = -1, si_cpu = -1;
+	int shallowest_idle_cpu = -1;
 	int i;
 
 	/* Check if we have any choice: */
@@ -5766,6 +5941,9 @@
 
 	/* Traverse only the allowed CPUs */
 	for_each_cpu_and(i, sched_group_span(group), p->cpus_ptr) {
+		if (sched_idle_cpu(i))
+			return i;
+
 		if (available_idle_cpu(i)) {
 			struct rq *rq = cpu_rq(i);
 			struct cpuidle_state *idle = idle_get_state(rq);
@@ -5788,13 +5966,8 @@
 				latest_idle_timestamp = rq->idle_stamp;
 				shallowest_idle_cpu = i;
 			}
-		} else if (shallowest_idle_cpu == -1 && si_cpu == -1) {
-			if (sched_idle_cpu(i)) {
-				si_cpu = i;
-				continue;
-			}
-
-			load = cpu_runnable_load(cpu_rq(i));
+		} else if (shallowest_idle_cpu == -1) {
+			load = cpu_load(cpu_rq(i));
 			if (load < min_load) {
 				min_load = load;
 				least_loaded_cpu = i;
@@ -5802,11 +5975,7 @@
 		}
 	}
 
-	if (shallowest_idle_cpu != -1)
-		return shallowest_idle_cpu;
-	if (si_cpu != -1)
-		return si_cpu;
-	return least_loaded_cpu;
+	return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu;
 }
 
 static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p,
@@ -5818,7 +5987,7 @@
 		return prev_cpu;
 
 	/*
-	 * We need task's util for capacity_spare_without, sync it up to
+	 * We need task's util for cpu_util_without, sync it up to
 	 * prev_cpu's last_update_time.
 	 */
 	if (!(sd_flag & SD_BALANCE_FORK))
@@ -5834,7 +6003,7 @@
 			continue;
 		}
 
-		group = find_idlest_group(sd, p, cpu, sd_flag);
+		group = find_idlest_group(sd, p, cpu);
 		if (!group) {
 			sd = sd->child;
 			continue;
@@ -5937,10 +6106,12 @@
 		bool idle = true;
 
 		for_each_cpu(cpu, cpu_smt_mask(core)) {
-			__cpumask_clear_cpu(cpu, cpus);
-			if (!available_idle_cpu(cpu))
+			if (!available_idle_cpu(cpu)) {
 				idle = false;
+				break;
+			}
 		}
+		cpumask_andnot(cpus, cpus, cpu_smt_mask(core));
 
 		if (idle)
 			return core;
@@ -5959,7 +6130,7 @@
  */
 static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target)
 {
-	int cpu, si_cpu = -1;
+	int cpu;
 
 	if (!static_branch_likely(&sched_smt_present))
 		return -1;
@@ -5968,13 +6139,11 @@
 		if (!cpumask_test_cpu(cpu, p->cpus_ptr) ||
 		    !cpumask_test_cpu(cpu, sched_domain_span(sd)))
 			continue;
-		if (available_idle_cpu(cpu))
+		if (available_idle_cpu(cpu) || sched_idle_cpu(cpu))
 			return cpu;
-		if (si_cpu == -1 && sched_idle_cpu(cpu))
-			si_cpu = cpu;
 	}
 
-	return si_cpu;
+	return -1;
 }
 
 #else /* CONFIG_SCHED_SMT */
@@ -6001,10 +6170,9 @@
 	struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
 	struct sched_domain *this_sd;
 	u64 avg_cost, avg_idle;
-	u64 time, cost;
-	s64 delta;
+	u64 time;
 	int this = smp_processor_id();
-	int cpu, nr = INT_MAX, si_cpu = -1;
+	int cpu, nr = INT_MAX;
 
 	this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc));
 	if (!this_sd)
@@ -6034,46 +6202,113 @@
 
 	for_each_cpu_wrap(cpu, cpus, target) {
 		if (!--nr)
-			return si_cpu;
-		if (available_idle_cpu(cpu))
+			return -1;
+		if (available_idle_cpu(cpu) || sched_idle_cpu(cpu))
 			break;
-		if (si_cpu == -1 && sched_idle_cpu(cpu))
-			si_cpu = cpu;
 	}
 
 	time = cpu_clock(this) - time;
-	cost = this_sd->avg_scan_cost;
-	delta = (s64)(time - cost) / 8;
-	this_sd->avg_scan_cost += delta;
+	update_avg(&this_sd->avg_scan_cost, time);
 
 	return cpu;
 }
 
 /*
+ * Scan the asym_capacity domain for idle CPUs; pick the first idle one on which
+ * the task fits. If no CPU is big enough, but there are idle ones, try to
+ * maximize capacity.
+ */
+static int
+select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target)
+{
+	unsigned long task_util, best_cap = 0;
+	int cpu, best_cpu = -1;
+	struct cpumask *cpus;
+
+	cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
+	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
+
+	task_util = uclamp_task_util(p);
+
+	for_each_cpu_wrap(cpu, cpus, target) {
+		unsigned long cpu_cap = capacity_of(cpu);
+
+		if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu))
+			continue;
+		if (fits_capacity(task_util, cpu_cap))
+			return cpu;
+
+		if (cpu_cap > best_cap) {
+			best_cap = cpu_cap;
+			best_cpu = cpu;
+		}
+	}
+
+	return best_cpu;
+}
+
+static inline bool asym_fits_capacity(int task_util, int cpu)
+{
+	if (static_branch_unlikely(&sched_asym_cpucapacity))
+		return fits_capacity(task_util, capacity_of(cpu));
+
+	return true;
+}
+
+/*
  * Try and locate an idle core/thread in the LLC cache domain.
  */
 static int select_idle_sibling(struct task_struct *p, int prev, int target)
 {
 	struct sched_domain *sd;
+	unsigned long task_util;
 	int i, recent_used_cpu;
 
-	if (available_idle_cpu(target) || sched_idle_cpu(target))
+	/*
+	 * On asymmetric system, update task utilization because we will check
+	 * that the task fits with cpu's capacity.
+	 */
+	if (static_branch_unlikely(&sched_asym_cpucapacity)) {
+		sync_entity_load_avg(&p->se);
+		task_util = uclamp_task_util(p);
+	}
+
+	if ((available_idle_cpu(target) || sched_idle_cpu(target)) &&
+	    asym_fits_capacity(task_util, target))
 		return target;
 
 	/*
 	 * If the previous CPU is cache affine and idle, don't be stupid:
 	 */
 	if (prev != target && cpus_share_cache(prev, target) &&
-	    (available_idle_cpu(prev) || sched_idle_cpu(prev)))
+	    (available_idle_cpu(prev) || sched_idle_cpu(prev)) &&
+	    asym_fits_capacity(task_util, prev))
 		return prev;
 
+	/*
+	 * Allow a per-cpu kthread to stack with the wakee if the
+	 * kworker thread and the tasks previous CPUs are the same.
+	 * The assumption is that the wakee queued work for the
+	 * per-cpu kthread that is now complete and the wakeup is
+	 * essentially a sync wakeup. An obvious example of this
+	 * pattern is IO completions.
+	 */
+	if (is_per_cpu_kthread(current) &&
+	    in_task() &&
+	    prev == smp_processor_id() &&
+	    this_rq()->nr_running <= 1 &&
+	    asym_fits_capacity(task_util, prev)) {
+		return prev;
+	}
+
 	/* Check a recently used CPU as a potential idle candidate: */
 	recent_used_cpu = p->recent_used_cpu;
 	if (recent_used_cpu != prev &&
 	    recent_used_cpu != target &&
 	    cpus_share_cache(recent_used_cpu, target) &&
 	    (available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu)) &&
-	    cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr)) {
+	    cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) &&
+	    asym_fits_capacity(task_util, recent_used_cpu)) {
 		/*
 		 * Replace recent_used_cpu with prev as it is a potential
 		 * candidate for the next wake:
@@ -6082,6 +6317,26 @@
 		return recent_used_cpu;
 	}
 
+	/*
+	 * For asymmetric CPU capacity systems, our domain of interest is
+	 * sd_asym_cpucapacity rather than sd_llc.
+	 */
+	if (static_branch_unlikely(&sched_asym_cpucapacity)) {
+		sd = rcu_dereference(per_cpu(sd_asym_cpucapacity, target));
+		/*
+		 * On an asymmetric CPU capacity system where an exclusive
+		 * cpuset defines a symmetric island (i.e. one unique
+		 * capacity_orig value through the cpuset), the key will be set
+		 * but the CPUs within that cpuset will not have a domain with
+		 * SD_ASYM_CPUCAPACITY. These should follow the usual symmetric
+		 * capacity path.
+		 */
+		if (sd) {
+			i = select_idle_capacity(p, sd, target);
+			return ((unsigned)i < nr_cpumask_bits) ? i : target;
+		}
+	}
+
 	sd = rcu_dereference(per_cpu(sd_llc, target));
 	if (!sd)
 		return target;
@@ -6243,33 +6498,6 @@
 }
 
 /*
- * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
- * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
- *
- * In that case WAKE_AFFINE doesn't make sense and we'll let
- * BALANCE_WAKE sort things out.
- */
-static int wake_cap(struct task_struct *p, int cpu, int prev_cpu)
-{
-	long min_cap, max_cap;
-
-	if (!static_branch_unlikely(&sched_asym_cpucapacity))
-		return 0;
-
-	min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu));
-	max_cap = cpu_rq(cpu)->rd->max_cpu_capacity;
-
-	/* Minimum capacity is close to max, no need to abort wake_affine */
-	if (max_cap - min_cap < max_cap >> 3)
-		return 0;
-
-	/* Bring task utilization in sync with prev_cpu */
-	sync_entity_load_avg(&p->se);
-
-	return !task_fits_capacity(p, min_cap);
-}
-
-/*
  * Predicts what cpu_util(@cpu) would return if @p was migrated (and enqueued)
  * to @dst_cpu.
  */
@@ -6356,7 +6584,7 @@
 		max_util = max(max_util, cpu_util);
 	}
 
-	return em_pd_energy(pd->em_pd, max_util, sum_util);
+	return em_cpu_energy(pd->em_pd, max_util, sum_util);
 }
 
 /*
@@ -6439,9 +6667,19 @@
 			if (!cpumask_test_cpu(cpu, p->cpus_ptr))
 				continue;
 
-			/* Skip CPUs that will be overutilized. */
 			util = cpu_util_next(cpu, p, cpu);
 			cpu_cap = capacity_of(cpu);
+			spare_cap = cpu_cap;
+			lsub_positive(&spare_cap, util);
+
+			/*
+			 * Skip CPUs that cannot satisfy the capacity request.
+			 * IOW, placing the task there would make the CPU
+			 * overutilized. Take uclamp into account to see how
+			 * much capacity we can get out of the CPU; this is
+			 * aligned with schedutil_cpu_util().
+			 */
+			util = uclamp_rq_util_with(cpu_rq(cpu), util, p);
 			if (!fits_capacity(util, cpu_cap))
 				continue;
 
@@ -6456,7 +6694,6 @@
 			 * Find the CPU with the maximum spare capacity in
 			 * the performance domain
 			 */
-			spare_cap = cpu_cap - util;
 			if (spare_cap > max_spare_cap) {
 				max_spare_cap = spare_cap;
 				max_spare_cap_cpu = cpu;
@@ -6525,15 +6762,11 @@
 			new_cpu = prev_cpu;
 		}
 
-		want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) &&
-			      cpumask_test_cpu(cpu, p->cpus_ptr);
+		want_affine = !wake_wide(p) && cpumask_test_cpu(cpu, p->cpus_ptr);
 	}
 
 	rcu_read_lock();
 	for_each_domain(cpu, tmp) {
-		if (!(tmp->flags & SD_LOAD_BALANCE))
-			break;
-
 		/*
 		 * If both 'cpu' and 'prev_cpu' are part of this domain,
 		 * cpu is a valid SD_WAKE_AFFINE target.
@@ -6813,7 +7046,7 @@
 		set_last_buddy(se);
 }
 
-static struct task_struct *
+struct task_struct *
 pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 {
 	struct cfs_rq *cfs_rq = &rq->cfs;
@@ -6957,6 +7190,11 @@
 	return NULL;
 }
 
+static struct task_struct *__pick_next_task_fair(struct rq *rq)
+{
+	return pick_next_task_fair(rq, NULL, NULL);
+}
+
 /*
  * Account for a descheduled task:
  */
@@ -7007,7 +7245,7 @@
 	set_skip_buddy(se);
 }
 
-static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preempt)
+static bool yield_to_task_fair(struct rq *rq, struct task_struct *p)
 {
 	struct sched_entity *se = &p->se;
 
@@ -7146,11 +7384,49 @@
 
 enum fbq_type { regular, remote, all };
 
+/*
+ * 'group_type' describes the group of CPUs at the moment of load balancing.
+ *
+ * The enum is ordered by pulling priority, with the group with lowest priority
+ * first so the group_type can simply be compared when selecting the busiest
+ * group. See update_sd_pick_busiest().
+ */
 enum group_type {
-	group_other = 0,
+	/* The group has spare capacity that can be used to run more tasks.  */
+	group_has_spare = 0,
+	/*
+	 * The group is fully used and the tasks don't compete for more CPU
+	 * cycles. Nevertheless, some tasks might wait before running.
+	 */
+	group_fully_busy,
+	/*
+	 * SD_ASYM_CPUCAPACITY only: One task doesn't fit with CPU's capacity
+	 * and must be migrated to a more powerful CPU.
+	 */
 	group_misfit_task,
+	/*
+	 * SD_ASYM_PACKING only: One local CPU with higher capacity is available,
+	 * and the task should be migrated to it instead of running on the
+	 * current CPU.
+	 */
+	group_asym_packing,
+	/*
+	 * The tasks' affinity constraints previously prevented the scheduler
+	 * from balancing the load across the system.
+	 */
 	group_imbalanced,
-	group_overloaded,
+	/*
+	 * The CPU is overloaded and can't provide expected CPU cycles to all
+	 * tasks.
+	 */
+	group_overloaded
+};
+
+enum migration_type {
+	migrate_load = 0,
+	migrate_util,
+	migrate_task,
+	migrate_misfit
 };
 
 #define LBF_ALL_PINNED	0x01
@@ -7183,7 +7459,7 @@
 	unsigned int		loop_max;
 
 	enum fbq_type		fbq_type;
-	enum group_type		src_grp_type;
+	enum migration_type	migration_type;
 	struct list_head	tasks;
 };
 
@@ -7202,6 +7478,10 @@
 	if (unlikely(task_has_idle_policy(p)))
 		return 0;
 
+	/* SMT siblings share cache */
+	if (env->sd->flags & SD_SHARE_CPUCAPACITY)
+		return 0;
+
 	/*
 	 * Buddy candidates are cache hot:
 	 */
@@ -7410,7 +7690,7 @@
 static const unsigned int sched_nr_migrate_break = 32;
 
 /*
- * detach_tasks() -- tries to detach up to imbalance runnable load from
+ * detach_tasks() -- tries to detach up to imbalance load/util/tasks from
  * busiest_rq, as part of a balancing operation within domain "sd".
  *
  * Returns number of detached tasks if successful and 0 otherwise.
@@ -7418,8 +7698,8 @@
 static int detach_tasks(struct lb_env *env)
 {
 	struct list_head *tasks = &env->src_rq->cfs_tasks;
+	unsigned long util, load;
 	struct task_struct *p;
-	unsigned long load;
 	int detached = 0;
 
 	lockdep_assert_held(&env->src_rq->lock);
@@ -7452,27 +7732,59 @@
 		if (!can_migrate_task(p, env))
 			goto next;
 
-		/*
-		 * Depending of the number of CPUs and tasks and the
-		 * cgroup hierarchy, task_h_load() can return a null
-		 * value. Make sure that env->imbalance decreases
-		 * otherwise detach_tasks() will stop only after
-		 * detaching up to loop_max tasks.
-		 */
-		load = max_t(unsigned long, task_h_load(p), 1);
+		switch (env->migration_type) {
+		case migrate_load:
+			/*
+			 * Depending of the number of CPUs and tasks and the
+			 * cgroup hierarchy, task_h_load() can return a null
+			 * value. Make sure that env->imbalance decreases
+			 * otherwise detach_tasks() will stop only after
+			 * detaching up to loop_max tasks.
+			 */
+			load = max_t(unsigned long, task_h_load(p), 1);
 
+			if (sched_feat(LB_MIN) &&
+			    load < 16 && !env->sd->nr_balance_failed)
+				goto next;
 
-		if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
-			goto next;
+			/*
+			 * Make sure that we don't migrate too much load.
+			 * Nevertheless, let relax the constraint if
+			 * scheduler fails to find a good waiting task to
+			 * migrate.
+			 */
+			if (shr_bound(load, env->sd->nr_balance_failed) > env->imbalance)
+				goto next;
 
-		if ((load / 2) > env->imbalance)
-			goto next;
+			env->imbalance -= load;
+			break;
+
+		case migrate_util:
+			util = task_util_est(p);
+
+			if (util > env->imbalance)
+				goto next;
+
+			env->imbalance -= util;
+			break;
+
+		case migrate_task:
+			env->imbalance--;
+			break;
+
+		case migrate_misfit:
+			/* This is not a misfit task */
+			if (task_fits_capacity(p, capacity_of(env->src_cpu)))
+				goto next;
+
+			env->imbalance = 0;
+			break;
+		}
 
 		detach_task(p, env);
 		list_add(&p->se.group_node, &env->tasks);
 
 		detached++;
-		env->imbalance -= load;
 
 #ifdef CONFIG_PREEMPTION
 		/*
@@ -7486,7 +7798,7 @@
 
 		/*
 		 * We only want to steal up to the prescribed amount of
-		 * runnable load.
+		 * load/util/tasks.
 		 */
 		if (env->imbalance <= 0)
 			break;
@@ -7575,6 +7887,9 @@
 	if (READ_ONCE(rq->avg_dl.util_avg))
 		return true;
 
+	if (thermal_load_avg(rq))
+		return true;
+
 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
 	if (READ_ONCE(rq->avg_irq.util_avg))
 		return true;
@@ -7600,6 +7915,7 @@
 {
 	const struct sched_class *curr_class;
 	u64 now = rq_clock_pelt(rq);
+	unsigned long thermal_pressure;
 	bool decayed;
 
 	/*
@@ -7608,8 +7924,11 @@
 	 */
 	curr_class = rq->curr->sched_class;
 
+	thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
+
 	decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) |
 		  update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) |
+		  update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure) |
 		  update_irq_load_avg(rq, 0);
 
 	if (others_have_blocked(rq))
@@ -7631,7 +7950,7 @@
 	if (cfs_rq->avg.util_sum)
 		return false;
 
-	if (cfs_rq->avg.runnable_load_sum)
+	if (cfs_rq->avg.runnable_sum)
 		return false;
 
 	return true;
@@ -7651,7 +7970,7 @@
 		struct sched_entity *se;
 
 		if (update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq)) {
-			update_tg_load_avg(cfs_rq, 0);
+			update_tg_load_avg(cfs_rq);
 
 			if (cfs_rq == &rq->cfs)
 				decayed = true;
@@ -7768,14 +8087,15 @@
 struct sg_lb_stats {
 	unsigned long avg_load; /*Avg load across the CPUs of the group */
 	unsigned long group_load; /* Total load over the CPUs of the group */
-	unsigned long load_per_task;
 	unsigned long group_capacity;
-	unsigned long group_util; /* Total utilization of the group */
-	unsigned int sum_nr_running; /* Nr tasks running in the group */
+	unsigned long group_util; /* Total utilization over the CPUs of the group */
+	unsigned long group_runnable; /* Total runnable time over the CPUs of the group */
+	unsigned int sum_nr_running; /* Nr of tasks running in the group */
+	unsigned int sum_h_nr_running; /* Nr of CFS tasks running in the group */
 	unsigned int idle_cpus;
 	unsigned int group_weight;
 	enum group_type group_type;
-	int group_no_capacity;
+	unsigned int group_asym_packing; /* Tasks should be moved to preferred CPU */
 	unsigned long group_misfit_task_load; /* A CPU has a task too big for its capacity */
 #ifdef CONFIG_NUMA_BALANCING
 	unsigned int nr_numa_running;
@@ -7790,10 +8110,10 @@
 struct sd_lb_stats {
 	struct sched_group *busiest;	/* Busiest group in this sd */
 	struct sched_group *local;	/* Local group in this sd */
-	unsigned long total_running;
 	unsigned long total_load;	/* Total load of all groups in sd */
 	unsigned long total_capacity;	/* Total capacity of all groups in sd */
 	unsigned long avg_load;	/* Average load across all groups in sd */
+	unsigned int prefer_sibling; /* tasks should go to sibling first */
 
 	struct sg_lb_stats busiest_stat;/* Statistics of the busiest group */
 	struct sg_lb_stats local_stat;	/* Statistics of the local group */
@@ -7804,24 +8124,23 @@
 	/*
 	 * Skimp on the clearing to avoid duplicate work. We can avoid clearing
 	 * local_stat because update_sg_lb_stats() does a full clear/assignment.
-	 * We must however clear busiest_stat::avg_load because
-	 * update_sd_pick_busiest() reads this before assignment.
+	 * We must however set busiest_stat::group_type and
+	 * busiest_stat::idle_cpus to the worst busiest group because
+	 * update_sd_pick_busiest() reads these before assignment.
 	 */
 	*sds = (struct sd_lb_stats){
 		.busiest = NULL,
 		.local = NULL,
-		.total_running = 0UL,
 		.total_load = 0UL,
 		.total_capacity = 0UL,
 		.busiest_stat = {
-			.avg_load = 0UL,
-			.sum_nr_running = 0,
-			.group_type = group_other,
+			.idle_cpus = UINT_MAX,
+			.group_type = group_has_spare,
 		},
 	};
 }
 
-static unsigned long scale_rt_capacity(struct sched_domain *sd, int cpu)
+static unsigned long scale_rt_capacity(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
 	unsigned long max = arch_scale_cpu_capacity(cpu);
@@ -7833,8 +8152,15 @@
 	if (unlikely(irq >= max))
 		return 1;
 
+	/*
+	 * avg_rt.util_avg and avg_dl.util_avg track binary signals
+	 * (running and not running) with weights 0 and 1024 respectively.
+	 * avg_thermal.load_avg tracks thermal pressure and the weighted
+	 * average uses the actual delta max capacity(load).
+	 */
 	used = READ_ONCE(rq->avg_rt.util_avg);
 	used += READ_ONCE(rq->avg_dl.util_avg);
+	used += thermal_load_avg(rq);
 
 	if (unlikely(used >= max))
 		return 1;
@@ -7846,7 +8172,7 @@
 
 static void update_cpu_capacity(struct sched_domain *sd, int cpu)
 {
-	unsigned long capacity = scale_rt_capacity(sd, cpu);
+	unsigned long capacity = scale_rt_capacity(cpu);
 	struct sched_group *sdg = sd->groups;
 
 	cpu_rq(cpu)->cpu_capacity_orig = arch_scale_cpu_capacity(cpu);
@@ -7855,6 +8181,8 @@
 		capacity = 1;
 
 	cpu_rq(cpu)->cpu_capacity = capacity;
+	trace_sched_cpu_capacity_tp(cpu_rq(cpu));
+
 	sdg->sgc->capacity = capacity;
 	sdg->sgc->min_capacity = capacity;
 	sdg->sgc->max_capacity = capacity;
@@ -7887,29 +8215,11 @@
 		 */
 
 		for_each_cpu(cpu, sched_group_span(sdg)) {
-			struct sched_group_capacity *sgc;
-			struct rq *rq = cpu_rq(cpu);
+			unsigned long cpu_cap = capacity_of(cpu);
 
-			/*
-			 * build_sched_domains() -> init_sched_groups_capacity()
-			 * gets here before we've attached the domains to the
-			 * runqueues.
-			 *
-			 * Use capacity_of(), which is set irrespective of domains
-			 * in update_cpu_capacity().
-			 *
-			 * This avoids capacity from being 0 and
-			 * causing divide-by-zero issues on boot.
-			 */
-			if (unlikely(!rq->sd)) {
-				capacity += capacity_of(cpu);
-			} else {
-				sgc = rq->sd->groups->sgc;
-				capacity += sgc->capacity;
-			}
-
-			min_capacity = min(capacity, min_capacity);
-			max_capacity = max(capacity, max_capacity);
+			capacity += cpu_cap;
+			min_capacity = min(cpu_cap, min_capacity);
+			max_capacity = max(cpu_cap, max_capacity);
 		}
 	} else  {
 		/*
@@ -8004,13 +8314,17 @@
  * any benefit for the load balance.
  */
 static inline bool
-group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs)
+group_has_capacity(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
 {
 	if (sgs->sum_nr_running < sgs->group_weight)
 		return true;
 
+	if ((sgs->group_capacity * imbalance_pct) <
+			(sgs->group_runnable * 100))
+		return false;
+
 	if ((sgs->group_capacity * 100) >
-			(sgs->group_util * env->sd->imbalance_pct))
+			(sgs->group_util * imbalance_pct))
 		return true;
 
 	return false;
@@ -8025,13 +8339,17 @@
  *  false.
  */
 static inline bool
-group_is_overloaded(struct lb_env *env, struct sg_lb_stats *sgs)
+group_is_overloaded(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
 {
 	if (sgs->sum_nr_running <= sgs->group_weight)
 		return false;
 
 	if ((sgs->group_capacity * 100) <
-			(sgs->group_util * env->sd->imbalance_pct))
+			(sgs->group_util * imbalance_pct))
+		return true;
+
+	if ((sgs->group_capacity * imbalance_pct) <
+			(sgs->group_runnable * 100))
 		return true;
 
 	return false;
@@ -8058,19 +8376,26 @@
 }
 
 static inline enum
-group_type group_classify(struct sched_group *group,
+group_type group_classify(unsigned int imbalance_pct,
+			  struct sched_group *group,
 			  struct sg_lb_stats *sgs)
 {
-	if (sgs->group_no_capacity)
+	if (group_is_overloaded(imbalance_pct, sgs))
 		return group_overloaded;
 
 	if (sg_imbalanced(group))
 		return group_imbalanced;
 
+	if (sgs->group_asym_packing)
+		return group_asym_packing;
+
 	if (sgs->group_misfit_task_load)
 		return group_misfit_task;
 
-	return group_other;
+	if (!group_has_capacity(imbalance_pct, sgs))
+		return group_fully_busy;
+
+	return group_has_spare;
 }
 
 static bool update_nohz_stats(struct rq *rq, bool force)
@@ -8107,21 +8432,26 @@
 				      struct sg_lb_stats *sgs,
 				      int *sg_status)
 {
-	int i, nr_running;
+	int i, nr_running, local_group;
 
 	memset(sgs, 0, sizeof(*sgs));
 
+	local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(group));
+
 	for_each_cpu_and(i, sched_group_span(group), env->cpus) {
 		struct rq *rq = cpu_rq(i);
 
 		if ((env->flags & LBF_NOHZ_STATS) && update_nohz_stats(rq, false))
 			env->flags |= LBF_NOHZ_AGAIN;
 
-		sgs->group_load += cpu_runnable_load(rq);
+		sgs->group_load += cpu_load(rq);
 		sgs->group_util += cpu_util(i);
-		sgs->sum_nr_running += rq->cfs.h_nr_running;
+		sgs->group_runnable += cpu_runnable(rq);
+		sgs->sum_h_nr_running += rq->cfs.h_nr_running;
 
 		nr_running = rq->nr_running;
+		sgs->sum_nr_running += nr_running;
+
 		if (nr_running > 1)
 			*sg_status |= SG_OVERLOAD;
 
@@ -8135,9 +8465,16 @@
 		/*
 		 * No need to call idle_cpu() if nr_running is not 0
 		 */
-		if (!nr_running && idle_cpu(i))
+		if (!nr_running && idle_cpu(i)) {
 			sgs->idle_cpus++;
+			/* Idle cpu can't have misfit task */
+			continue;
+		}
 
+		if (local_group)
+			continue;
+
+		/* Check for a misfit task on the cpu */
 		if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
 		    sgs->group_misfit_task_load < rq->misfit_task_load) {
 			sgs->group_misfit_task_load = rq->misfit_task_load;
@@ -8145,17 +8482,24 @@
 		}
 	}
 
-	/* Adjust by relative CPU capacity of the group */
-	sgs->group_capacity = group->sgc->capacity;
-	sgs->avg_load = (sgs->group_load*SCHED_CAPACITY_SCALE) / sgs->group_capacity;
+	/* Check if dst CPU is idle and preferred to this group */
+	if (env->sd->flags & SD_ASYM_PACKING &&
+	    env->idle != CPU_NOT_IDLE &&
+	    sgs->sum_h_nr_running &&
+	    sched_asym_prefer(env->dst_cpu, group->asym_prefer_cpu)) {
+		sgs->group_asym_packing = 1;
+	}
 
-	if (sgs->sum_nr_running)
-		sgs->load_per_task = sgs->group_load / sgs->sum_nr_running;
+	sgs->group_capacity = group->sgc->capacity;
 
 	sgs->group_weight = group->group_weight;
 
-	sgs->group_no_capacity = group_is_overloaded(env, sgs);
-	sgs->group_type = group_classify(group, sgs);
+	sgs->group_type = group_classify(env->sd->imbalance_pct, group, sgs);
+
+	/* Computing avg_load makes sense only when group is overloaded */
+	if (sgs->group_type == group_overloaded)
+		sgs->avg_load = (sgs->group_load * SCHED_CAPACITY_SCALE) /
+				sgs->group_capacity;
 }
 
 /**
@@ -8178,6 +8522,10 @@
 {
 	struct sg_lb_stats *busiest = &sds->busiest_stat;
 
+	/* Make sure that there is at least one task to pull */
+	if (!sgs->sum_h_nr_running)
+		return false;
+
 	/*
 	 * Don't try to pull misfit tasks we can't help.
 	 * We can use max_capacity here as reduction in capacity on some
@@ -8186,7 +8534,7 @@
 	 */
 	if (sgs->group_type == group_misfit_task &&
 	    (!group_smaller_max_cpu_capacity(sg, sds->local) ||
-	     !group_has_capacity(env, &sds->local_stat)))
+	     sds->local_stat.group_type != group_has_spare))
 		return false;
 
 	if (sgs->group_type > busiest->group_type)
@@ -8195,62 +8543,92 @@
 	if (sgs->group_type < busiest->group_type)
 		return false;
 
-	if (sgs->avg_load <= busiest->avg_load)
+	/*
+	 * The candidate and the current busiest group are the same type of
+	 * group. Let check which one is the busiest according to the type.
+	 */
+
+	switch (sgs->group_type) {
+	case group_overloaded:
+		/* Select the overloaded group with highest avg_load. */
+		if (sgs->avg_load <= busiest->avg_load)
+			return false;
+		break;
+
+	case group_imbalanced:
+		/*
+		 * Select the 1st imbalanced group as we don't have any way to
+		 * choose one more than another.
+		 */
 		return false;
 
-	if (!(env->sd->flags & SD_ASYM_CPUCAPACITY))
-		goto asym_packing;
-
-	/*
-	 * Candidate sg has no more than one task per CPU and
-	 * has higher per-CPU capacity. Migrating tasks to less
-	 * capable CPUs may harm throughput. Maximize throughput,
-	 * power/energy consequences are not considered.
-	 */
-	if (sgs->sum_nr_running <= sgs->group_weight &&
-	    group_smaller_min_cpu_capacity(sds->local, sg))
-		return false;
-
-	/*
-	 * If we have more than one misfit sg go with the biggest misfit.
-	 */
-	if (sgs->group_type == group_misfit_task &&
-	    sgs->group_misfit_task_load < busiest->group_misfit_task_load)
-		return false;
-
-asym_packing:
-	/* This is the busiest node in its class. */
-	if (!(env->sd->flags & SD_ASYM_PACKING))
-		return true;
-
-	/* No ASYM_PACKING if target CPU is already busy */
-	if (env->idle == CPU_NOT_IDLE)
-		return true;
-	/*
-	 * ASYM_PACKING needs to move all the work to the highest
-	 * prority CPUs in the group, therefore mark all groups
-	 * of lower priority than ourself as busy.
-	 */
-	if (sgs->sum_nr_running &&
-	    sched_asym_prefer(env->dst_cpu, sg->asym_prefer_cpu)) {
-		if (!sds->busiest)
-			return true;
-
+	case group_asym_packing:
 		/* Prefer to move from lowest priority CPU's work */
-		if (sched_asym_prefer(sds->busiest->asym_prefer_cpu,
-				      sg->asym_prefer_cpu))
-			return true;
+		if (sched_asym_prefer(sg->asym_prefer_cpu, sds->busiest->asym_prefer_cpu))
+			return false;
+		break;
+
+	case group_misfit_task:
+		/*
+		 * If we have more than one misfit sg go with the biggest
+		 * misfit.
+		 */
+		if (sgs->group_misfit_task_load < busiest->group_misfit_task_load)
+			return false;
+		break;
+
+	case group_fully_busy:
+		/*
+		 * Select the fully busy group with highest avg_load. In
+		 * theory, there is no need to pull task from such kind of
+		 * group because tasks have all compute capacity that they need
+		 * but we can still improve the overall throughput by reducing
+		 * contention when accessing shared HW resources.
+		 *
+		 * XXX for now avg_load is not computed and always 0 so we
+		 * select the 1st one.
+		 */
+		if (sgs->avg_load <= busiest->avg_load)
+			return false;
+		break;
+
+	case group_has_spare:
+		/*
+		 * Select not overloaded group with lowest number of idle cpus
+		 * and highest number of running tasks. We could also compare
+		 * the spare capacity which is more stable but it can end up
+		 * that the group has less spare capacity but finally more idle
+		 * CPUs which means less opportunity to pull tasks.
+		 */
+		if (sgs->idle_cpus > busiest->idle_cpus)
+			return false;
+		else if ((sgs->idle_cpus == busiest->idle_cpus) &&
+			 (sgs->sum_nr_running <= busiest->sum_nr_running))
+			return false;
+
+		break;
 	}
 
-	return false;
+	/*
+	 * Candidate sg has no more than one task per CPU and has higher
+	 * per-CPU capacity. Migrating tasks to less capable CPUs may harm
+	 * throughput. Maximize throughput, power/energy consequences are not
+	 * considered.
+	 */
+	if ((env->sd->flags & SD_ASYM_CPUCAPACITY) &&
+	    (sgs->group_type <= group_fully_busy) &&
+	    (group_smaller_min_cpu_capacity(sds->local, sg)))
+		return false;
+
+	return true;
 }
 
 #ifdef CONFIG_NUMA_BALANCING
 static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs)
 {
-	if (sgs->sum_nr_running > sgs->nr_numa_running)
+	if (sgs->sum_h_nr_running > sgs->nr_numa_running)
 		return regular;
-	if (sgs->sum_nr_running > sgs->nr_preferred_running)
+	if (sgs->sum_h_nr_running > sgs->nr_preferred_running)
 		return remote;
 	return all;
 }
@@ -8275,18 +8653,323 @@
 }
 #endif /* CONFIG_NUMA_BALANCING */
 
+
+struct sg_lb_stats;
+
+/*
+ * task_running_on_cpu - return 1 if @p is running on @cpu.
+ */
+
+static unsigned int task_running_on_cpu(int cpu, struct task_struct *p)
+{
+	/* Task has no contribution or is new */
+	if (cpu != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time))
+		return 0;
+
+	if (task_on_rq_queued(p))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * idle_cpu_without - would a given CPU be idle without p ?
+ * @cpu: the processor on which idleness is tested.
+ * @p: task which should be ignored.
+ *
+ * Return: 1 if the CPU would be idle. 0 otherwise.
+ */
+static int idle_cpu_without(int cpu, struct task_struct *p)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	if (rq->curr != rq->idle && rq->curr != p)
+		return 0;
+
+	/*
+	 * rq->nr_running can't be used but an updated version without the
+	 * impact of p on cpu must be used instead. The updated nr_running
+	 * be computed and tested before calling idle_cpu_without().
+	 */
+
+#ifdef CONFIG_SMP
+	if (rq->ttwu_pending)
+		return 0;
+#endif
+
+	return 1;
+}
+
+/*
+ * update_sg_wakeup_stats - Update sched_group's statistics for wakeup.
+ * @sd: The sched_domain level to look for idlest group.
+ * @group: sched_group whose statistics are to be updated.
+ * @sgs: variable to hold the statistics for this group.
+ * @p: The task for which we look for the idlest group/CPU.
+ */
+static inline void update_sg_wakeup_stats(struct sched_domain *sd,
+					  struct sched_group *group,
+					  struct sg_lb_stats *sgs,
+					  struct task_struct *p)
+{
+	int i, nr_running;
+
+	memset(sgs, 0, sizeof(*sgs));
+
+	for_each_cpu(i, sched_group_span(group)) {
+		struct rq *rq = cpu_rq(i);
+		unsigned int local;
+
+		sgs->group_load += cpu_load_without(rq, p);
+		sgs->group_util += cpu_util_without(i, p);
+		sgs->group_runnable += cpu_runnable_without(rq, p);
+		local = task_running_on_cpu(i, p);
+		sgs->sum_h_nr_running += rq->cfs.h_nr_running - local;
+
+		nr_running = rq->nr_running - local;
+		sgs->sum_nr_running += nr_running;
+
+		/*
+		 * No need to call idle_cpu_without() if nr_running is not 0
+		 */
+		if (!nr_running && idle_cpu_without(i, p))
+			sgs->idle_cpus++;
+
+	}
+
+	/* Check if task fits in the group */
+	if (sd->flags & SD_ASYM_CPUCAPACITY &&
+	    !task_fits_capacity(p, group->sgc->max_capacity)) {
+		sgs->group_misfit_task_load = 1;
+	}
+
+	sgs->group_capacity = group->sgc->capacity;
+
+	sgs->group_weight = group->group_weight;
+
+	sgs->group_type = group_classify(sd->imbalance_pct, group, sgs);
+
+	/*
+	 * Computing avg_load makes sense only when group is fully busy or
+	 * overloaded
+	 */
+	if (sgs->group_type == group_fully_busy ||
+		sgs->group_type == group_overloaded)
+		sgs->avg_load = (sgs->group_load * SCHED_CAPACITY_SCALE) /
+				sgs->group_capacity;
+}
+
+static bool update_pick_idlest(struct sched_group *idlest,
+			       struct sg_lb_stats *idlest_sgs,
+			       struct sched_group *group,
+			       struct sg_lb_stats *sgs)
+{
+	if (sgs->group_type < idlest_sgs->group_type)
+		return true;
+
+	if (sgs->group_type > idlest_sgs->group_type)
+		return false;
+
+	/*
+	 * The candidate and the current idlest group are the same type of
+	 * group. Let check which one is the idlest according to the type.
+	 */
+
+	switch (sgs->group_type) {
+	case group_overloaded:
+	case group_fully_busy:
+		/* Select the group with lowest avg_load. */
+		if (idlest_sgs->avg_load <= sgs->avg_load)
+			return false;
+		break;
+
+	case group_imbalanced:
+	case group_asym_packing:
+		/* Those types are not used in the slow wakeup path */
+		return false;
+
+	case group_misfit_task:
+		/* Select group with the highest max capacity */
+		if (idlest->sgc->max_capacity >= group->sgc->max_capacity)
+			return false;
+		break;
+
+	case group_has_spare:
+		/* Select group with most idle CPUs */
+		if (idlest_sgs->idle_cpus > sgs->idle_cpus)
+			return false;
+
+		/* Select group with lowest group_util */
+		if (idlest_sgs->idle_cpus == sgs->idle_cpus &&
+			idlest_sgs->group_util <= sgs->group_util)
+			return false;
+
+		break;
+	}
+
+	return true;
+}
+
+/*
+ * find_idlest_group() finds and returns the least busy CPU group within the
+ * domain.
+ *
+ * Assumes p is allowed on at least one CPU in sd.
+ */
+static struct sched_group *
+find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
+{
+	struct sched_group *idlest = NULL, *local = NULL, *group = sd->groups;
+	struct sg_lb_stats local_sgs, tmp_sgs;
+	struct sg_lb_stats *sgs;
+	unsigned long imbalance;
+	struct sg_lb_stats idlest_sgs = {
+			.avg_load = UINT_MAX,
+			.group_type = group_overloaded,
+	};
+
+	imbalance = scale_load_down(NICE_0_LOAD) *
+				(sd->imbalance_pct-100) / 100;
+
+	do {
+		int local_group;
+
+		/* Skip over this group if it has no CPUs allowed */
+		if (!cpumask_intersects(sched_group_span(group),
+					p->cpus_ptr))
+			continue;
+
+		local_group = cpumask_test_cpu(this_cpu,
+					       sched_group_span(group));
+
+		if (local_group) {
+			sgs = &local_sgs;
+			local = group;
+		} else {
+			sgs = &tmp_sgs;
+		}
+
+		update_sg_wakeup_stats(sd, group, sgs, p);
+
+		if (!local_group && update_pick_idlest(idlest, &idlest_sgs, group, sgs)) {
+			idlest = group;
+			idlest_sgs = *sgs;
+		}
+
+	} while (group = group->next, group != sd->groups);
+
+
+	/* There is no idlest group to push tasks to */
+	if (!idlest)
+		return NULL;
+
+	/* The local group has been skipped because of CPU affinity */
+	if (!local)
+		return idlest;
+
+	/*
+	 * If the local group is idler than the selected idlest group
+	 * don't try and push the task.
+	 */
+	if (local_sgs.group_type < idlest_sgs.group_type)
+		return NULL;
+
+	/*
+	 * If the local group is busier than the selected idlest group
+	 * try and push the task.
+	 */
+	if (local_sgs.group_type > idlest_sgs.group_type)
+		return idlest;
+
+	switch (local_sgs.group_type) {
+	case group_overloaded:
+	case group_fully_busy:
+		/*
+		 * When comparing groups across NUMA domains, it's possible for
+		 * the local domain to be very lightly loaded relative to the
+		 * remote domains but "imbalance" skews the comparison making
+		 * remote CPUs look much more favourable. When considering
+		 * cross-domain, add imbalance to the load on the remote node
+		 * and consider staying local.
+		 */
+
+		if ((sd->flags & SD_NUMA) &&
+		    ((idlest_sgs.avg_load + imbalance) >= local_sgs.avg_load))
+			return NULL;
+
+		/*
+		 * If the local group is less loaded than the selected
+		 * idlest group don't try and push any tasks.
+		 */
+		if (idlest_sgs.avg_load >= (local_sgs.avg_load + imbalance))
+			return NULL;
+
+		if (100 * local_sgs.avg_load <= sd->imbalance_pct * idlest_sgs.avg_load)
+			return NULL;
+		break;
+
+	case group_imbalanced:
+	case group_asym_packing:
+		/* Those type are not used in the slow wakeup path */
+		return NULL;
+
+	case group_misfit_task:
+		/* Select group with the highest max capacity */
+		if (local->sgc->max_capacity >= idlest->sgc->max_capacity)
+			return NULL;
+		break;
+
+	case group_has_spare:
+		if (sd->flags & SD_NUMA) {
+#ifdef CONFIG_NUMA_BALANCING
+			int idlest_cpu;
+			/*
+			 * If there is spare capacity at NUMA, try to select
+			 * the preferred node
+			 */
+			if (cpu_to_node(this_cpu) == p->numa_preferred_nid)
+				return NULL;
+
+			idlest_cpu = cpumask_first(sched_group_span(idlest));
+			if (cpu_to_node(idlest_cpu) == p->numa_preferred_nid)
+				return idlest;
+#endif
+			/*
+			 * Otherwise, keep the task on this node to stay close
+			 * its wakeup source and improve locality. If there is
+			 * a real need of migration, periodic load balance will
+			 * take care of it.
+			 */
+			if (local_sgs.idle_cpus)
+				return NULL;
+		}
+
+		/*
+		 * Select group with highest number of idle CPUs. We could also
+		 * compare the utilization which is more stable but it can end
+		 * up that the group has less spare capacity but finally more
+		 * idle CPUs which means more opportunity to run task.
+		 */
+		if (local_sgs.idle_cpus >= idlest_sgs.idle_cpus)
+			return NULL;
+		break;
+	}
+
+	return idlest;
+}
+
 /**
  * update_sd_lb_stats - Update sched_domain's statistics for load balancing.
  * @env: The load balancing environment.
  * @sds: variable to hold the statistics for this sched_domain.
  */
+
 static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds)
 {
 	struct sched_domain *child = env->sd->child;
 	struct sched_group *sg = env->sd->groups;
 	struct sg_lb_stats *local = &sds->local_stat;
 	struct sg_lb_stats tmp_sgs;
-	bool prefer_sibling = child && child->flags & SD_PREFER_SIBLING;
 	int sg_status = 0;
 
 #ifdef CONFIG_NO_HZ_COMMON
@@ -8313,22 +8996,6 @@
 		if (local_group)
 			goto next_group;
 
-		/*
-		 * In case the child domain prefers tasks go to siblings
-		 * first, lower the sg capacity so that we'll try
-		 * and move all the excess tasks away. We lower the capacity
-		 * of a group only if the local group has the capacity to fit
-		 * these excess tasks. The extra check prevents the case where
-		 * you always pull from the heaviest group when it is already
-		 * under-utilized (possible with a large weight task outweighs
-		 * the tasks on the system).
-		 */
-		if (prefer_sibling && sds->local &&
-		    group_has_capacity(env, local) &&
-		    (sgs->sum_nr_running > local->sum_nr_running + 1)) {
-			sgs->group_no_capacity = 1;
-			sgs->group_type = group_classify(sg, sgs);
-		}
 
 		if (update_sd_pick_busiest(env, sds, sg, sgs)) {
 			sds->busiest = sg;
@@ -8337,13 +9004,15 @@
 
 next_group:
 		/* Now, start updating sd_lb_stats */
-		sds->total_running += sgs->sum_nr_running;
 		sds->total_load += sgs->group_load;
 		sds->total_capacity += sgs->group_capacity;
 
 		sg = sg->next;
 	} while (sg != env->sd->groups);
 
+	/* Tag domain that child domain prefers tasks go to siblings first */
+	sds->prefer_sibling = child && child->flags & SD_PREFER_SIBLING;
+
 #ifdef CONFIG_NO_HZ_COMMON
 	if ((env->flags & LBF_NOHZ_AGAIN) &&
 	    cpumask_subset(nohz.idle_cpus_mask, sched_domain_span(env->sd))) {
@@ -8373,119 +9042,19 @@
 	}
 }
 
-/**
- * check_asym_packing - Check to see if the group is packed into the
- *			sched domain.
- *
- * This is primarily intended to used at the sibling level.  Some
- * cores like POWER7 prefer to use lower numbered SMT threads.  In the
- * case of POWER7, it can move to lower SMT modes only when higher
- * threads are idle.  When in lower SMT modes, the threads will
- * perform better since they share less core resources.  Hence when we
- * have idle threads, we want them to be the higher ones.
- *
- * This packing function is run on idle threads.  It checks to see if
- * the busiest CPU in this domain (core in the P7 case) has a higher
- * CPU number than the packing function is being run on.  Here we are
- * assuming lower CPU number will be equivalent to lower a SMT thread
- * number.
- *
- * Return: 1 when packing is required and a task should be moved to
- * this CPU.  The amount of the imbalance is returned in env->imbalance.
- *
- * @env: The load balancing environment.
- * @sds: Statistics of the sched_domain which is to be packed
- */
-static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds)
+static inline long adjust_numa_imbalance(int imbalance, int nr_running)
 {
-	int busiest_cpu;
-
-	if (!(env->sd->flags & SD_ASYM_PACKING))
-		return 0;
-
-	if (env->idle == CPU_NOT_IDLE)
-		return 0;
-
-	if (!sds->busiest)
-		return 0;
-
-	busiest_cpu = sds->busiest->asym_prefer_cpu;
-	if (sched_asym_prefer(busiest_cpu, env->dst_cpu))
-		return 0;
-
-	env->imbalance = sds->busiest_stat.group_load;
-
-	return 1;
-}
-
-/**
- * fix_small_imbalance - Calculate the minor imbalance that exists
- *			amongst the groups of a sched_domain, during
- *			load balancing.
- * @env: The load balancing environment.
- * @sds: Statistics of the sched_domain whose imbalance is to be calculated.
- */
-static inline
-void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
-{
-	unsigned long tmp, capa_now = 0, capa_move = 0;
-	unsigned int imbn = 2;
-	unsigned long scaled_busy_load_per_task;
-	struct sg_lb_stats *local, *busiest;
-
-	local = &sds->local_stat;
-	busiest = &sds->busiest_stat;
-
-	if (!local->sum_nr_running)
-		local->load_per_task = cpu_avg_load_per_task(env->dst_cpu);
-	else if (busiest->load_per_task > local->load_per_task)
-		imbn = 1;
-
-	scaled_busy_load_per_task =
-		(busiest->load_per_task * SCHED_CAPACITY_SCALE) /
-		busiest->group_capacity;
-
-	if (busiest->avg_load + scaled_busy_load_per_task >=
-	    local->avg_load + (scaled_busy_load_per_task * imbn)) {
-		env->imbalance = busiest->load_per_task;
-		return;
-	}
+	unsigned int imbalance_min;
 
 	/*
-	 * OK, we don't have enough imbalance to justify moving tasks,
-	 * however we may be able to increase total CPU capacity used by
-	 * moving them.
+	 * Allow a small imbalance based on a simple pair of communicating
+	 * tasks that remain local when the source domain is almost idle.
 	 */
+	imbalance_min = 2;
+	if (nr_running <= imbalance_min)
+		return 0;
 
-	capa_now += busiest->group_capacity *
-			min(busiest->load_per_task, busiest->avg_load);
-	capa_now += local->group_capacity *
-			min(local->load_per_task, local->avg_load);
-	capa_now /= SCHED_CAPACITY_SCALE;
-
-	/* Amount of load we'd subtract */
-	if (busiest->avg_load > scaled_busy_load_per_task) {
-		capa_move += busiest->group_capacity *
-			    min(busiest->load_per_task,
-				busiest->avg_load - scaled_busy_load_per_task);
-	}
-
-	/* Amount of load we'd add */
-	if (busiest->avg_load * busiest->group_capacity <
-	    busiest->load_per_task * SCHED_CAPACITY_SCALE) {
-		tmp = (busiest->avg_load * busiest->group_capacity) /
-		      local->group_capacity;
-	} else {
-		tmp = (busiest->load_per_task * SCHED_CAPACITY_SCALE) /
-		      local->group_capacity;
-	}
-	capa_move += local->group_capacity *
-		    min(local->load_per_task, local->avg_load + tmp);
-	capa_move /= SCHED_CAPACITY_SCALE;
-
-	/* Move if we gain throughput */
-	if (capa_move > capa_now)
-		env->imbalance = busiest->load_per_task;
+	return imbalance;
 }
 
 /**
@@ -8496,81 +9065,164 @@
  */
 static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
 {
-	unsigned long max_pull, load_above_capacity = ~0UL;
 	struct sg_lb_stats *local, *busiest;
 
 	local = &sds->local_stat;
 	busiest = &sds->busiest_stat;
 
+	if (busiest->group_type == group_misfit_task) {
+		/* Set imbalance to allow misfit tasks to be balanced. */
+		env->migration_type = migrate_misfit;
+		env->imbalance = 1;
+		return;
+	}
+
+	if (busiest->group_type == group_asym_packing) {
+		/*
+		 * In case of asym capacity, we will try to migrate all load to
+		 * the preferred CPU.
+		 */
+		env->migration_type = migrate_task;
+		env->imbalance = busiest->sum_h_nr_running;
+		return;
+	}
+
 	if (busiest->group_type == group_imbalanced) {
 		/*
 		 * In the group_imb case we cannot rely on group-wide averages
-		 * to ensure CPU-load equilibrium, look at wider averages. XXX
+		 * to ensure CPU-load equilibrium, try to move any task to fix
+		 * the imbalance. The next load balance will take care of
+		 * balancing back the system.
 		 */
-		busiest->load_per_task =
-			min(busiest->load_per_task, sds->avg_load);
+		env->migration_type = migrate_task;
+		env->imbalance = 1;
+		return;
 	}
 
 	/*
-	 * Avg load of busiest sg can be less and avg load of local sg can
-	 * be greater than avg load across all sgs of sd because avg load
-	 * factors in sg capacity and sgs with smaller group_type are
-	 * skipped when updating the busiest sg:
+	 * Try to use spare capacity of local group without overloading it or
+	 * emptying busiest.
 	 */
-	if (busiest->group_type != group_misfit_task &&
-	    (busiest->avg_load <= sds->avg_load ||
-	     local->avg_load >= sds->avg_load)) {
-		env->imbalance = 0;
-		return fix_small_imbalance(env, sds);
+	if (local->group_type == group_has_spare) {
+		if ((busiest->group_type > group_fully_busy) &&
+		    !(env->sd->flags & SD_SHARE_PKG_RESOURCES)) {
+			/*
+			 * If busiest is overloaded, try to fill spare
+			 * capacity. This might end up creating spare capacity
+			 * in busiest or busiest still being overloaded but
+			 * there is no simple way to directly compute the
+			 * amount of load to migrate in order to balance the
+			 * system.
+			 */
+			env->migration_type = migrate_util;
+			env->imbalance = max(local->group_capacity, local->group_util) -
+					 local->group_util;
+
+			/*
+			 * In some cases, the group's utilization is max or even
+			 * higher than capacity because of migrations but the
+			 * local CPU is (newly) idle. There is at least one
+			 * waiting task in this overloaded busiest group. Let's
+			 * try to pull it.
+			 */
+			if (env->idle != CPU_NOT_IDLE && env->imbalance == 0) {
+				env->migration_type = migrate_task;
+				env->imbalance = 1;
+			}
+
+			return;
+		}
+
+		if (busiest->group_weight == 1 || sds->prefer_sibling) {
+			unsigned int nr_diff = busiest->sum_nr_running;
+			/*
+			 * When prefer sibling, evenly spread running tasks on
+			 * groups.
+			 */
+			env->migration_type = migrate_task;
+			lsub_positive(&nr_diff, local->sum_nr_running);
+			env->imbalance = nr_diff >> 1;
+		} else {
+
+			/*
+			 * If there is no overload, we just want to even the number of
+			 * idle cpus.
+			 */
+			env->migration_type = migrate_task;
+			env->imbalance = max_t(long, 0, (local->idle_cpus -
+						 busiest->idle_cpus) >> 1);
+		}
+
+		/* Consider allowing a small imbalance between NUMA groups */
+		if (env->sd->flags & SD_NUMA)
+			env->imbalance = adjust_numa_imbalance(env->imbalance,
+						busiest->sum_nr_running);
+
+		return;
 	}
 
 	/*
-	 * If there aren't any idle CPUs, avoid creating some.
+	 * Local is fully busy but has to take more load to relieve the
+	 * busiest group
 	 */
-	if (busiest->group_type == group_overloaded &&
-	    local->group_type   == group_overloaded) {
-		load_above_capacity = busiest->sum_nr_running * SCHED_CAPACITY_SCALE;
-		if (load_above_capacity > busiest->group_capacity) {
-			load_above_capacity -= busiest->group_capacity;
-			load_above_capacity *= scale_load_down(NICE_0_LOAD);
-			load_above_capacity /= busiest->group_capacity;
-		} else
-			load_above_capacity = ~0UL;
+	if (local->group_type < group_overloaded) {
+		/*
+		 * Local will become overloaded so the avg_load metrics are
+		 * finally needed.
+		 */
+
+		local->avg_load = (local->group_load * SCHED_CAPACITY_SCALE) /
+				  local->group_capacity;
+
+		sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
+				sds->total_capacity;
+		/*
+		 * If the local group is more loaded than the selected
+		 * busiest group don't try to pull any tasks.
+		 */
+		if (local->avg_load >= busiest->avg_load) {
+			env->imbalance = 0;
+			return;
+		}
 	}
 
 	/*
-	 * We're trying to get all the CPUs to the average_load, so we don't
-	 * want to push ourselves above the average load, nor do we wish to
-	 * reduce the max loaded CPU below the average load. At the same time,
-	 * we also don't want to reduce the group load below the group
-	 * capacity. Thus we look for the minimum possible imbalance.
+	 * Both group are or will become overloaded and we're trying to get all
+	 * the CPUs to the average_load, so we don't want to push ourselves
+	 * above the average load, nor do we wish to reduce the max loaded CPU
+	 * below the average load. At the same time, we also don't want to
+	 * reduce the group load below the group capacity. Thus we look for
+	 * the minimum possible imbalance.
 	 */
-	max_pull = min(busiest->avg_load - sds->avg_load, load_above_capacity);
-
-	/* How much load to actually move to equalise the imbalance */
+	env->migration_type = migrate_load;
 	env->imbalance = min(
-		max_pull * busiest->group_capacity,
+		(busiest->avg_load - sds->avg_load) * busiest->group_capacity,
 		(sds->avg_load - local->avg_load) * local->group_capacity
 	) / SCHED_CAPACITY_SCALE;
-
-	/* Boost imbalance to allow misfit task to be balanced. */
-	if (busiest->group_type == group_misfit_task) {
-		env->imbalance = max_t(long, env->imbalance,
-				       busiest->group_misfit_task_load);
-	}
-
-	/*
-	 * if *imbalance is less than the average load per runnable task
-	 * there is no guarantee that any tasks will be moved so we'll have
-	 * a think about bumping its value to force at least one task to be
-	 * moved
-	 */
-	if (env->imbalance < busiest->load_per_task)
-		return fix_small_imbalance(env, sds);
 }
 
 /******* find_busiest_group() helpers end here *********************/
 
+/*
+ * Decision matrix according to the local and busiest group type:
+ *
+ * busiest \ local has_spare fully_busy misfit asym imbalanced overloaded
+ * has_spare        nr_idle   balanced   N/A    N/A  balanced   balanced
+ * fully_busy       nr_idle   nr_idle    N/A    N/A  balanced   balanced
+ * misfit_task      force     N/A        N/A    N/A  force      force
+ * asym_packing     force     force      N/A    N/A  force      force
+ * imbalanced       force     force      N/A    N/A  force      force
+ * overloaded       force     force      N/A    N/A  force      avg_load
+ *
+ * N/A :      Not Applicable because already filtered while updating
+ *            statistics.
+ * balanced : The system is balanced for these 2 groups.
+ * force :    Calculate the imbalance as load migration is probably needed.
+ * avg_load : Only if imbalance is significant enough.
+ * nr_idle :  dst_cpu is not busy and the number of idle CPUs is quite
+ *            different in groups.
+ */
+
 /**
  * find_busiest_group - Returns the busiest group within the sched_domain
  * if there is an imbalance.
@@ -8590,7 +9242,7 @@
 	init_sd_lb_stats(&sds);
 
 	/*
-	 * Compute the various statistics relavent for load balancing at
+	 * Compute the various statistics relevant for load balancing at
 	 * this level.
 	 */
 	update_sd_lb_stats(env, &sds);
@@ -8605,17 +9257,17 @@
 	local = &sds.local_stat;
 	busiest = &sds.busiest_stat;
 
-	/* ASYM feature bypasses nice load balance check */
-	if (check_asym_packing(env, &sds))
-		return sds.busiest;
-
 	/* There is no busy sibling group to pull tasks from */
-	if (!sds.busiest || busiest->sum_nr_running == 0)
+	if (!sds.busiest)
 		goto out_balanced;
 
-	/* XXX broken for overlapping NUMA groups */
-	sds.avg_load = (SCHED_CAPACITY_SCALE * sds.total_load)
-						/ sds.total_capacity;
+	/* Misfit tasks should be dealt with regardless of the avg load */
+	if (busiest->group_type == group_misfit_task)
+		goto force_balance;
+
+	/* ASYM feature bypasses nice load balance check */
+	if (busiest->group_type == group_asym_packing)
+		goto force_balance;
 
 	/*
 	 * If the busiest group is imbalanced the below checks don't
@@ -8626,55 +9278,80 @@
 		goto force_balance;
 
 	/*
-	 * When dst_cpu is idle, prevent SMP nice and/or asymmetric group
-	 * capacities from resulting in underutilization due to avg_load.
-	 */
-	if (env->idle != CPU_NOT_IDLE && group_has_capacity(env, local) &&
-	    busiest->group_no_capacity)
-		goto force_balance;
-
-	/* Misfit tasks should be dealt with regardless of the avg load */
-	if (busiest->group_type == group_misfit_task)
-		goto force_balance;
-
-	/*
 	 * If the local group is busier than the selected busiest group
 	 * don't try and pull any tasks.
 	 */
-	if (local->avg_load >= busiest->avg_load)
+	if (local->group_type > busiest->group_type)
 		goto out_balanced;
 
 	/*
-	 * Don't pull any tasks if this group is already above the domain
-	 * average load.
+	 * When groups are overloaded, use the avg_load to ensure fairness
+	 * between tasks.
 	 */
-	if (local->avg_load >= sds.avg_load)
-		goto out_balanced;
-
-	if (env->idle == CPU_IDLE) {
+	if (local->group_type == group_overloaded) {
 		/*
-		 * This CPU is idle. If the busiest group is not overloaded
-		 * and there is no imbalance between this and busiest group
-		 * wrt idle CPUs, it is balanced. The imbalance becomes
-		 * significant if the diff is greater than 1 otherwise we
-		 * might end up to just move the imbalance on another group
+		 * If the local group is more loaded than the selected
+		 * busiest group don't try to pull any tasks.
 		 */
-		if ((busiest->group_type != group_overloaded) &&
-				(local->idle_cpus <= (busiest->idle_cpus + 1)))
+		if (local->avg_load >= busiest->avg_load)
 			goto out_balanced;
-	} else {
+
+		/* XXX broken for overlapping NUMA groups */
+		sds.avg_load = (sds.total_load * SCHED_CAPACITY_SCALE) /
+				sds.total_capacity;
+
 		/*
-		 * In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use
-		 * imbalance_pct to be conservative.
+		 * Don't pull any tasks if this group is already above the
+		 * domain average load.
+		 */
+		if (local->avg_load >= sds.avg_load)
+			goto out_balanced;
+
+		/*
+		 * If the busiest group is more loaded, use imbalance_pct to be
+		 * conservative.
 		 */
 		if (100 * busiest->avg_load <=
 				env->sd->imbalance_pct * local->avg_load)
 			goto out_balanced;
 	}
 
+	/* Try to move all excess tasks to child's sibling domain */
+	if (sds.prefer_sibling && local->group_type == group_has_spare &&
+	    busiest->sum_nr_running > local->sum_nr_running + 1)
+		goto force_balance;
+
+	if (busiest->group_type != group_overloaded) {
+		if (env->idle == CPU_NOT_IDLE)
+			/*
+			 * If the busiest group is not overloaded (and as a
+			 * result the local one too) but this CPU is already
+			 * busy, let another idle CPU try to pull task.
+			 */
+			goto out_balanced;
+
+		if (busiest->group_weight > 1 &&
+		    local->idle_cpus <= (busiest->idle_cpus + 1))
+			/*
+			 * If the busiest group is not overloaded
+			 * and there is no imbalance between this and busiest
+			 * group wrt idle CPUs, it is balanced. The imbalance
+			 * becomes significant if the diff is greater than 1
+			 * otherwise we might end up to just move the imbalance
+			 * on another group. Of course this applies only if
+			 * there is more than 1 CPU per group.
+			 */
+			goto out_balanced;
+
+		if (busiest->sum_h_nr_running == 1)
+			/*
+			 * busiest doesn't have any tasks waiting to run
+			 */
+			goto out_balanced;
+	}
+
 force_balance:
 	/* Looks like there is an imbalance. Compute it */
-	env->src_grp_type = busiest->group_type;
 	calculate_imbalance(env, &sds);
 	return env->imbalance ? sds.busiest : NULL;
 
@@ -8690,11 +9367,13 @@
 				     struct sched_group *group)
 {
 	struct rq *busiest = NULL, *rq;
-	unsigned long busiest_load = 0, busiest_capacity = 1;
+	unsigned long busiest_util = 0, busiest_load = 0, busiest_capacity = 1;
+	unsigned int busiest_nr = 0;
 	int i;
 
 	for_each_cpu_and(i, sched_group_span(group), env->cpus) {
-		unsigned long capacity, load;
+		unsigned long capacity, load, util;
+		unsigned int nr_running;
 		enum fbq_type rt;
 
 		rq = cpu_rq(i);
@@ -8722,20 +9401,8 @@
 		if (rt > env->fbq_type)
 			continue;
 
-		/*
-		 * For ASYM_CPUCAPACITY domains with misfit tasks we simply
-		 * seek the "biggest" misfit task.
-		 */
-		if (env->src_grp_type == group_misfit_task) {
-			if (rq->misfit_task_load > busiest_load) {
-				busiest_load = rq->misfit_task_load;
-				busiest = rq;
-			}
-
-			continue;
-		}
-
 		capacity = capacity_of(i);
+		nr_running = rq->cfs.h_nr_running;
 
 		/*
 		 * For ASYM_CPUCAPACITY domains, don't pick a CPU that could
@@ -8745,35 +9412,77 @@
 		 */
 		if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
 		    capacity_of(env->dst_cpu) < capacity &&
-		    rq->nr_running == 1)
+		    nr_running == 1)
 			continue;
 
-		load = cpu_runnable_load(rq);
+		switch (env->migration_type) {
+		case migrate_load:
+			/*
+			 * When comparing with load imbalance, use cpu_load()
+			 * which is not scaled with the CPU capacity.
+			 */
+			load = cpu_load(rq);
 
-		/*
-		 * When comparing with imbalance, use cpu_runnable_load()
-		 * which is not scaled with the CPU capacity.
-		 */
+			if (nr_running == 1 && load > env->imbalance &&
+			    !check_cpu_capacity(rq, env->sd))
+				break;
 
-		if (rq->nr_running == 1 && load > env->imbalance &&
-		    !check_cpu_capacity(rq, env->sd))
-			continue;
+			/*
+			 * For the load comparisons with the other CPUs,
+			 * consider the cpu_load() scaled with the CPU
+			 * capacity, so that the load can be moved away
+			 * from the CPU that is potentially running at a
+			 * lower capacity.
+			 *
+			 * Thus we're looking for max(load_i / capacity_i),
+			 * crosswise multiplication to rid ourselves of the
+			 * division works out to:
+			 * load_i * capacity_j > load_j * capacity_i;
+			 * where j is our previous maximum.
+			 */
+			if (load * busiest_capacity > busiest_load * capacity) {
+				busiest_load = load;
+				busiest_capacity = capacity;
+				busiest = rq;
+			}
+			break;
 
-		/*
-		 * For the load comparisons with the other CPU's, consider
-		 * the cpu_runnable_load() scaled with the CPU capacity, so
-		 * that the load can be moved away from the CPU that is
-		 * potentially running at a lower capacity.
-		 *
-		 * Thus we're looking for max(load_i / capacity_i), crosswise
-		 * multiplication to rid ourselves of the division works out
-		 * to: load_i * capacity_j > load_j * capacity_i;  where j is
-		 * our previous maximum.
-		 */
-		if (load * busiest_capacity > busiest_load * capacity) {
-			busiest_load = load;
-			busiest_capacity = capacity;
-			busiest = rq;
+		case migrate_util:
+			util = cpu_util(cpu_of(rq));
+
+			/*
+			 * Don't try to pull utilization from a CPU with one
+			 * running task. Whatever its utilization, we will fail
+			 * detach the task.
+			 */
+			if (nr_running <= 1)
+				continue;
+
+			if (busiest_util < util) {
+				busiest_util = util;
+				busiest = rq;
+			}
+			break;
+
+		case migrate_task:
+			if (busiest_nr < nr_running) {
+				busiest_nr = nr_running;
+				busiest = rq;
+			}
+			break;
+
+		case migrate_misfit:
+			/*
+			 * For ASYM_CPUCAPACITY domains with misfit tasks we
+			 * simply seek the "biggest" misfit task.
+			 */
+			if (rq->misfit_task_load > busiest_load) {
+				busiest_load = rq->misfit_task_load;
+				busiest = rq;
+			}
+
+			break;
+
 		}
 	}
 
@@ -8819,7 +9528,7 @@
 			return 1;
 	}
 
-	if (env->src_grp_type == group_misfit_task)
+	if (env->migration_type == migrate_misfit)
 		return 1;
 
 	return 0;
@@ -8840,7 +9549,7 @@
 static int should_we_balance(struct lb_env *env)
 {
 	struct sched_group *sg = env->sd->groups;
-	int cpu, balance_cpu = -1;
+	int cpu;
 
 	/*
 	 * Ensure the balancing environment is consistent; can happen
@@ -8861,18 +9570,12 @@
 		if (!idle_cpu(cpu))
 			continue;
 
-		balance_cpu = cpu;
-		break;
+		/* Are we the first idle CPU? */
+		return cpu == env->dst_cpu;
 	}
 
-	if (balance_cpu == -1)
-		balance_cpu = group_balance_cpu(sg);
-
-	/*
-	 * First idle CPU or the first CPU(busiest) in this sched group
-	 * is eligible for doing load balancing at this and above domains.
-	 */
-	return balance_cpu == env->dst_cpu;
+	/* Are we the first CPU of this group ? */
+	return group_balance_cpu(sg) == env->dst_cpu;
 }
 
 /*
@@ -9163,6 +9866,15 @@
 
 	/* scale ms to jiffies */
 	interval = msecs_to_jiffies(interval);
+
+	/*
+	 * Reduce likelihood of busy balancing at higher domains racing with
+	 * balancing at lower domains by preventing their balancing periods
+	 * from being multiples of each other.
+	 */
+	if (cpu_busy)
+		interval -= 1;
+
 	interval = clamp(interval, 1UL, max_load_balance_interval);
 
 	return interval;
@@ -9225,9 +9937,8 @@
 	/* Search for an sd spanning us and the target CPU. */
 	rcu_read_lock();
 	for_each_domain(target_cpu, sd) {
-		if ((sd->flags & SD_LOAD_BALANCE) &&
-		    cpumask_test_cpu(busiest_cpu, sched_domain_span(sd)))
-				break;
+		if (cpumask_test_cpu(busiest_cpu, sched_domain_span(sd)))
+			break;
 	}
 
 	if (likely(sd)) {
@@ -9293,6 +10004,7 @@
 {
 	int continue_balancing = 1;
 	int cpu = rq->cpu;
+	int busy = idle != CPU_IDLE && !sched_idle_cpu(cpu);
 	unsigned long interval;
 	struct sched_domain *sd;
 	/* Earliest time when we have to do rebalance again */
@@ -9315,9 +10027,6 @@
 		}
 		max_cost += sd->max_newidle_lb_cost;
 
-		if (!(sd->flags & SD_LOAD_BALANCE))
-			continue;
-
 		/*
 		 * Stop the load balance at this level. There is another
 		 * CPU in our sched group which is doing load balancing more
@@ -9329,7 +10038,7 @@
 			break;
 		}
 
-		interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
+		interval = get_sd_balance_interval(sd, busy);
 
 		need_serialize = sd->flags & SD_SERIALIZE;
 		if (need_serialize) {
@@ -9345,9 +10054,10 @@
 				 * state even if we migrated tasks. Update it.
 				 */
 				idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
+				busy = idle != CPU_IDLE && !sched_idle_cpu(cpu);
 			}
 			sd->last_balance = jiffies;
-			interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
+			interval = get_sd_balance_interval(sd, busy);
 		}
 		if (need_serialize)
 			spin_unlock(&balancing);
@@ -9438,17 +10148,20 @@
 	if (ilb_cpu >= nr_cpu_ids)
 		return;
 
+	/*
+	 * Access to rq::nohz_csd is serialized by NOHZ_KICK_MASK; he who sets
+	 * the first flag owns it; cleared by nohz_csd_func().
+	 */
 	flags = atomic_fetch_or(flags, nohz_flags(ilb_cpu));
 	if (flags & NOHZ_KICK_MASK)
 		return;
 
 	/*
-	 * Use smp_send_reschedule() instead of resched_cpu().
-	 * This way we generate a sched IPI on the target CPU which
+	 * This way we generate an IPI on the target CPU which
 	 * is idle. And the softirq performing nohz idle load balance
 	 * will be run before returning from the IPI.
 	 */
-	smp_send_reschedule(ilb_cpu);
+	smp_call_function_single_async(ilb_cpu, &cpu_rq(ilb_cpu)->nohz_csd);
 }
 
 /*
@@ -9786,20 +10499,14 @@
  */
 static bool nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
 {
-	int this_cpu = this_rq->cpu;
-	unsigned int flags;
+	unsigned int flags = this_rq->nohz_idle_balance;
 
-	if (!(atomic_read(nohz_flags(this_cpu)) & NOHZ_KICK_MASK))
+	if (!flags)
 		return false;
 
-	if (idle != CPU_IDLE) {
-		atomic_andnot(NOHZ_KICK_MASK, nohz_flags(this_cpu));
-		return false;
-	}
+	this_rq->nohz_idle_balance = 0;
 
-	/* could be _relaxed() */
-	flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(this_cpu));
-	if (!(flags & NOHZ_KICK_MASK))
+	if (idle != CPU_IDLE)
 		return false;
 
 	_nohz_idle_balance(this_rq, flags, idle);
@@ -9853,8 +10560,13 @@
 /*
  * idle_balance is called by schedule() if this_cpu is about to become
  * idle. Attempts to pull tasks from other CPUs.
+ *
+ * Returns:
+ *   < 0 - we released the lock and there are !fair tasks present
+ *     0 - failed, no new tasks
+ *   > 0 - success, new (fair) tasks present
  */
-int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
+static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 {
 	unsigned long next_balance = jiffies + HZ;
 	int this_cpu = this_rq->cpu;
@@ -9905,9 +10617,6 @@
 		int continue_balancing = 1;
 		u64 t0, domain_cost;
 
-		if (!(sd->flags & SD_LOAD_BALANCE))
-			continue;
-
 		if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) {
 			update_next_balance(sd, &next_balance);
 			break;
@@ -10097,6 +10806,9 @@
 	if (!task_on_rq_queued(p))
 		return;
 
+	if (rq->cfs.nr_running == 1)
+		return;
+
 	/*
 	 * Reschedule if we are currently running on this runqueue and
 	 * our priority decreased, or if we are not currently running on
@@ -10175,7 +10887,7 @@
 	/* Catch up with the cfs_rq and remove our load when we leave */
 	update_load_avg(cfs_rq, se, 0);
 	detach_entity_load_avg(cfs_rq, se);
-	update_tg_load_avg(cfs_rq, false);
+	update_tg_load_avg(cfs_rq);
 	propagate_entity_cfs_rq(se);
 }
 
@@ -10193,8 +10905,8 @@
 
 	/* Synchronize entity with its cfs_rq */
 	update_load_avg(cfs_rq, se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD);
-	attach_entity_load_avg(cfs_rq, se, 0);
-	update_tg_load_avg(cfs_rq, false);
+	attach_entity_load_avg(cfs_rq, se);
+	update_tg_load_avg(cfs_rq);
 	propagate_entity_cfs_rq(se);
 }
 
@@ -10526,8 +11238,8 @@
 /*
  * All the scheduling class methods:
  */
-const struct sched_class fair_sched_class = {
-	.next			= &idle_sched_class,
+const struct sched_class fair_sched_class
+	__section("__fair_sched_class") = {
 	.enqueue_task		= enqueue_task_fair,
 	.dequeue_task		= dequeue_task_fair,
 	.yield_task		= yield_task_fair,
@@ -10535,7 +11247,7 @@
 
 	.check_preempt_curr	= check_preempt_wakeup,
 
-	.pick_next_task		= pick_next_task_fair,
+	.pick_next_task		= __pick_next_task_fair,
 	.put_prev_task		= put_prev_task_fair,
 	.set_next_task          = set_next_task_fair,
 
@@ -10691,6 +11403,18 @@
 }
 EXPORT_SYMBOL_GPL(sched_trace_rq_cpu);
 
+int sched_trace_rq_cpu_capacity(struct rq *rq)
+{
+	return rq ?
+#ifdef CONFIG_SMP
+		rq->cpu_capacity
+#else
+		SCHED_CAPACITY_SCALE
+#endif
+		: -1;
+}
+EXPORT_SYMBOL_GPL(sched_trace_rq_cpu_capacity);
+
 const struct cpumask *sched_trace_rd_span(struct root_domain *rd)
 {
 #ifdef CONFIG_SMP
@@ -10700,3 +11424,9 @@
 #endif
 }
 EXPORT_SYMBOL_GPL(sched_trace_rd_span);
+
+int sched_trace_rq_nr_running(struct rq *rq)
+{
+        return rq ? rq->nr_running : -1;
+}
+EXPORT_SYMBOL_GPL(sched_trace_rq_nr_running);
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 2410db5..f1bf5e1 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -77,7 +77,7 @@
 SCHED_FEAT(RT_PUSH_IPI, true)
 #endif
 
-SCHED_FEAT(RT_RUNTIME_SHARE, true)
+SCHED_FEAT(RT_RUNTIME_SHARE, false)
 SCHED_FEAT(LB_MIN, false)
 SCHED_FEAT(ATTACH_AGE_LOAD, true)
 
@@ -89,3 +89,7 @@
  * UtilEstimation. Use estimated CPU utilization.
  */
 SCHED_FEAT(UTIL_EST, true)
+SCHED_FEAT(UTIL_EST_FASTUP, true)
+
+SCHED_FEAT(ALT_PERIOD, true)
+SCHED_FEAT(BASE_SLICE, true)
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 3f8c786..2593a73 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -54,17 +54,18 @@
 
 static noinline int __cpuidle cpu_idle_poll(void)
 {
-	rcu_idle_enter();
-	trace_cpu_idle_rcuidle(0, smp_processor_id());
-	local_irq_enable();
+	trace_cpu_idle(0, smp_processor_id());
 	stop_critical_timings();
+	rcu_idle_enter();
+	local_irq_enable();
 
 	while (!tif_need_resched() &&
-		(cpu_idle_force_poll || tick_check_broadcast_expired()))
+	       (cpu_idle_force_poll || tick_check_broadcast_expired()))
 		cpu_relax();
-	start_critical_timings();
-	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+
 	rcu_idle_exit();
+	start_critical_timings();
+	trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
 
 	return 1;
 }
@@ -77,7 +78,7 @@
 void __weak arch_cpu_idle(void)
 {
 	cpu_idle_force_poll = 1;
-	local_irq_enable();
+	raw_local_irq_enable();
 }
 
 /**
@@ -90,12 +91,52 @@
 	if (current_clr_polling_and_test()) {
 		local_irq_enable();
 	} else {
+
+		trace_cpu_idle(1, smp_processor_id());
 		stop_critical_timings();
+
+		/*
+		 * arch_cpu_idle() is supposed to enable IRQs, however
+		 * we can't do that because of RCU and tracing.
+		 *
+		 * Trace IRQs enable here, then switch off RCU, and have
+		 * arch_cpu_idle() use raw_local_irq_enable(). Note that
+		 * rcu_idle_enter() relies on lockdep IRQ state, so switch that
+		 * last -- this is very similar to the entry code.
+		 */
+		trace_hardirqs_on_prepare();
+		lockdep_hardirqs_on_prepare(_THIS_IP_);
+		rcu_idle_enter();
+		lockdep_hardirqs_on(_THIS_IP_);
+
 		arch_cpu_idle();
+
+		/*
+		 * OK, so IRQs are enabled here, but RCU needs them disabled to
+		 * turn itself back on.. funny thing is that disabling IRQs
+		 * will cause tracing, which needs RCU. Jump through hoops to
+		 * make it 'work'.
+		 */
+		raw_local_irq_disable();
+		lockdep_hardirqs_off(_THIS_IP_);
+		rcu_idle_exit();
+		lockdep_hardirqs_on(_THIS_IP_);
+		raw_local_irq_enable();
+
 		start_critical_timings();
+		trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
 	}
 }
 
+static int call_cpuidle_s2idle(struct cpuidle_driver *drv,
+			       struct cpuidle_device *dev)
+{
+	if (current_clr_polling_and_test())
+		return -EBUSY;
+
+	return cpuidle_enter_s2idle(drv, dev);
+}
+
 static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		      int next_state)
 {
@@ -104,7 +145,7 @@
 	 * update no idle residency and return.
 	 */
 	if (current_clr_polling_and_test()) {
-		dev->last_residency = 0;
+		dev->last_residency_ns = 0;
 		local_irq_enable();
 		return -EBUSY;
 	}
@@ -149,7 +190,6 @@
 
 	if (cpuidle_not_available(drv, dev)) {
 		tick_nohz_idle_stop_tick();
-		rcu_idle_enter();
 
 		default_idle_call();
 		goto exit_idle;
@@ -158,30 +198,30 @@
 	/*
 	 * Suspend-to-idle ("s2idle") is a system state in which all user space
 	 * has been frozen, all I/O devices have been suspended and the only
-	 * activity happens here and in iterrupts (if any).  In that case bypass
+	 * activity happens here and in interrupts (if any). In that case bypass
 	 * the cpuidle governor and go stratight for the deepest idle state
 	 * available.  Possibly also suspend the local tick and the entire
 	 * timekeeping to prevent timer interrupts from kicking us out of idle
 	 * until a proper wakeup interrupt happens.
 	 */
 
-	if (idle_should_enter_s2idle() || dev->use_deepest_state) {
+	if (idle_should_enter_s2idle() || dev->forced_idle_latency_limit_ns) {
+		u64 max_latency_ns;
+
 		if (idle_should_enter_s2idle()) {
-			rcu_idle_enter();
 
-			entered_state = cpuidle_enter_s2idle(drv, dev);
-			if (entered_state > 0) {
-				local_irq_enable();
+			entered_state = call_cpuidle_s2idle(drv, dev);
+			if (entered_state > 0)
 				goto exit_idle;
-			}
 
-			rcu_idle_exit();
+			max_latency_ns = U64_MAX;
+		} else {
+			max_latency_ns = dev->forced_idle_latency_limit_ns;
 		}
 
 		tick_nohz_idle_stop_tick();
-		rcu_idle_enter();
 
-		next_state = cpuidle_find_deepest_state(drv, dev);
+		next_state = cpuidle_find_deepest_state(drv, dev, max_latency_ns);
 		call_cpuidle(drv, dev, next_state);
 	} else {
 		bool stop_tick = true;
@@ -196,8 +236,6 @@
 		else
 			tick_nohz_idle_retain_tick();
 
-		rcu_idle_enter();
-
 		entered_state = call_cpuidle(drv, dev, next_state);
 		/*
 		 * Give the governor an opportunity to reflect on the outcome
@@ -213,8 +251,6 @@
 	 */
 	if (WARN_ON_ONCE(irqs_disabled()))
 		local_irq_enable();
-
-	rcu_idle_exit();
 }
 
 /*
@@ -284,7 +320,11 @@
 	 */
 	smp_mb__after_atomic();
 
-	sched_ttwu_pending();
+	/*
+	 * RCU relies on this call to be done outside of an RCU read-side
+	 * critical section.
+	 */
+	flush_smp_call_function_from_idle();
 	schedule_idle();
 
 	if (unlikely(klp_patch_pending(current)))
@@ -312,7 +352,7 @@
 	return HRTIMER_NORESTART;
 }
 
-void play_idle(unsigned long duration_us)
+void play_idle_precise(u64 duration_ns, u64 latency_ns)
 {
 	struct idle_timer it;
 
@@ -324,29 +364,29 @@
 	WARN_ON_ONCE(current->nr_cpus_allowed != 1);
 	WARN_ON_ONCE(!(current->flags & PF_KTHREAD));
 	WARN_ON_ONCE(!(current->flags & PF_NO_SETAFFINITY));
-	WARN_ON_ONCE(!duration_us);
+	WARN_ON_ONCE(!duration_ns);
 
 	rcu_sleep_check();
 	preempt_disable();
 	current->flags |= PF_IDLE;
-	cpuidle_use_deepest_state(true);
+	cpuidle_use_deepest_state(latency_ns);
 
 	it.done = 0;
-	hrtimer_init_on_stack(&it.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init_on_stack(&it.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	it.timer.function = idle_inject_timer_fn;
-	hrtimer_start(&it.timer, ns_to_ktime(duration_us * NSEC_PER_USEC),
-		      HRTIMER_MODE_REL_PINNED);
+	hrtimer_start(&it.timer, ns_to_ktime(duration_ns),
+		      HRTIMER_MODE_REL_PINNED_HARD);
 
 	while (!READ_ONCE(it.done))
 		do_idle();
 
-	cpuidle_use_deepest_state(false);
+	cpuidle_use_deepest_state(0);
 	current->flags &= ~PF_IDLE;
 
 	preempt_fold_need_resched();
 	preempt_enable();
 }
-EXPORT_SYMBOL_GPL(play_idle);
+EXPORT_SYMBOL_GPL(play_idle_precise);
 
 void cpu_startup_entry(enum cpuhp_state state)
 {
@@ -392,14 +432,10 @@
 	schedstat_inc(rq->sched_goidle);
 }
 
-static struct task_struct *
-pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+struct task_struct *pick_next_task_idle(struct rq *rq)
 {
 	struct task_struct *next = rq->idle;
 
-	if (prev)
-		put_prev_task(rq, prev);
-
 	set_next_task_idle(rq, next, true);
 
 	return next;
@@ -441,11 +477,6 @@
 	BUG();
 }
 
-static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task)
-{
-	return 0;
-}
-
 static void update_curr_idle(struct rq *rq)
 {
 }
@@ -453,8 +484,8 @@
 /*
  * Simple, special scheduling class for the per-CPU idle tasks:
  */
-const struct sched_class idle_sched_class = {
-	/* .next is NULL */
+const struct sched_class idle_sched_class
+	__section("__idle_sched_class") = {
 	/* no enqueue/yield_task for idle tasks */
 
 	/* dequeue is not valid, we print a debug message there: */
@@ -474,8 +505,6 @@
 
 	.task_tick		= task_tick_idle,
 
-	.get_rr_interval	= get_rr_interval_idle,
-
 	.prio_changed		= prio_changed_idle,
 	.switched_to		= switched_to_idle,
 	.update_curr		= update_curr_idle,
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 9fcb2a6..5a6ea03 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -140,7 +140,8 @@
 {
 	unsigned int flags;
 
-	flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC;
+	flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU |
+		HK_FLAG_MISC | HK_FLAG_KTHREAD;
 
 	return housekeeping_setup(str, flags);
 }
@@ -149,6 +150,9 @@
 static int __init housekeeping_isolcpus_setup(char *str)
 {
 	unsigned int flags = 0;
+	bool illegal = false;
+	char *par;
+	int len;
 
 	while (isalpha(*str)) {
 		if (!strncmp(str, "nohz,", 5)) {
@@ -163,8 +167,28 @@
 			continue;
 		}
 
-		pr_warn("isolcpus: Error, unknown flag\n");
-		return 0;
+		if (!strncmp(str, "managed_irq,", 12)) {
+			str += 12;
+			flags |= HK_FLAG_MANAGED_IRQ;
+			continue;
+		}
+
+		/*
+		 * Skip unknown sub-parameter and validate that it is not
+		 * containing an invalid character.
+		 */
+		for (par = str, len = 0; *str && *str != ','; str++, len++) {
+			if (!isalpha(*str) && *str != '_')
+				illegal = true;
+		}
+
+		if (illegal) {
+			pr_warn("isolcpus: Invalid flag %.*s\n", len, par);
+			return 0;
+		}
+
+		pr_info("isolcpus: Skipped unknown flag %.*s\n", len, par);
+		str++;
 	}
 
 	/* Default behaviour for isolcpus without flags */
diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c
index de22da6..d2a6556 100644
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -347,7 +347,7 @@
  *
  * Called from the global timer code.
  */
-void calc_global_load(unsigned long ticks)
+void calc_global_load(void)
 {
 	unsigned long sample_window;
 	long active, delta;
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 46c142b..cc7cd51 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -18,12 +18,21 @@
 #define MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK	0
 #endif
 
+#ifdef CONFIG_RSEQ
+#define MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK		\
+	(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ			\
+	| MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ)
+#else
+#define MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK	0
+#endif
+
 #define MEMBARRIER_CMD_BITMASK						\
 	(MEMBARRIER_CMD_GLOBAL | MEMBARRIER_CMD_GLOBAL_EXPEDITED	\
 	| MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED			\
 	| MEMBARRIER_CMD_PRIVATE_EXPEDITED				\
 	| MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED			\
-	| MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK)
+	| MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK		\
+	| MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK)
 
 static void ipi_mb(void *info)
 {
@@ -47,6 +56,19 @@
 	sync_core_before_usermode();
 }
 
+static void ipi_rseq(void *info)
+{
+	/*
+	 * Ensure that all stores done by the calling thread are visible
+	 * to the current task before the current task resumes.  We could
+	 * probably optimize this away on most architectures, but by the
+	 * time we've already sent an IPI, the cost of the extra smp_mb()
+	 * is negligible.
+	 */
+	smp_mb();
+	rseq_preempt(current);
+}
+
 static void ipi_sync_rq_state(void *info)
 {
 	struct mm_struct *mm = (struct mm_struct *) info;
@@ -146,27 +168,35 @@
 	return 0;
 }
 
-static int membarrier_private_expedited(int flags)
+static int membarrier_private_expedited(int flags, int cpu_id)
 {
-	int cpu;
 	cpumask_var_t tmpmask;
 	struct mm_struct *mm = current->mm;
 	smp_call_func_t ipi_func = ipi_mb;
 
-	if (flags & MEMBARRIER_FLAG_SYNC_CORE) {
+	if (flags == MEMBARRIER_FLAG_SYNC_CORE) {
 		if (!IS_ENABLED(CONFIG_ARCH_HAS_MEMBARRIER_SYNC_CORE))
 			return -EINVAL;
 		if (!(atomic_read(&mm->membarrier_state) &
 		      MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY))
 			return -EPERM;
 		ipi_func = ipi_sync_core;
+	} else if (flags == MEMBARRIER_FLAG_RSEQ) {
+		if (!IS_ENABLED(CONFIG_RSEQ))
+			return -EINVAL;
+		if (!(atomic_read(&mm->membarrier_state) &
+		      MEMBARRIER_STATE_PRIVATE_EXPEDITED_RSEQ_READY))
+			return -EPERM;
+		ipi_func = ipi_rseq;
 	} else {
+		WARN_ON_ONCE(flags);
 		if (!(atomic_read(&mm->membarrier_state) &
 		      MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY))
 			return -EPERM;
 	}
 
-	if (atomic_read(&mm->mm_users) == 1 || num_online_cpus() == 1)
+	if (flags != MEMBARRIER_FLAG_SYNC_CORE &&
+	    (atomic_read(&mm->mm_users) == 1 || num_online_cpus() == 1))
 		return 0;
 
 	/*
@@ -175,35 +205,73 @@
 	 */
 	smp_mb();	/* system call entry is not a mb. */
 
-	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
+	if (cpu_id < 0 && !zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
 		return -ENOMEM;
 
 	cpus_read_lock();
-	rcu_read_lock();
-	for_each_online_cpu(cpu) {
+
+	if (cpu_id >= 0) {
 		struct task_struct *p;
 
-		/*
-		 * Skipping the current CPU is OK even through we can be
-		 * migrated at any point. The current CPU, at the point
-		 * where we read raw_smp_processor_id(), is ensured to
-		 * be in program order with respect to the caller
-		 * thread. Therefore, we can skip this CPU from the
-		 * iteration.
-		 */
-		if (cpu == raw_smp_processor_id())
-			continue;
-		p = rcu_dereference(cpu_rq(cpu)->curr);
-		if (p && p->mm == mm)
-			__cpumask_set_cpu(cpu, tmpmask);
+		if (cpu_id >= nr_cpu_ids || !cpu_online(cpu_id))
+			goto out;
+		rcu_read_lock();
+		p = rcu_dereference(cpu_rq(cpu_id)->curr);
+		if (!p || p->mm != mm) {
+			rcu_read_unlock();
+			goto out;
+		}
+		rcu_read_unlock();
+	} else {
+		int cpu;
+
+		rcu_read_lock();
+		for_each_online_cpu(cpu) {
+			struct task_struct *p;
+
+			p = rcu_dereference(cpu_rq(cpu)->curr);
+			if (p && p->mm == mm)
+				__cpumask_set_cpu(cpu, tmpmask);
+		}
+		rcu_read_unlock();
 	}
-	rcu_read_unlock();
 
-	preempt_disable();
-	smp_call_function_many(tmpmask, ipi_func, NULL, 1);
-	preempt_enable();
+	if (cpu_id >= 0) {
+		/*
+		 * smp_call_function_single() will call ipi_func() if cpu_id
+		 * is the calling CPU.
+		 */
+		smp_call_function_single(cpu_id, ipi_func, NULL, 1);
+	} else {
+		/*
+		 * For regular membarrier, we can save a few cycles by
+		 * skipping the current cpu -- we're about to do smp_mb()
+		 * below, and if we migrate to a different cpu, this cpu
+		 * and the new cpu will execute a full barrier in the
+		 * scheduler.
+		 *
+		 * For SYNC_CORE, we do need a barrier on the current cpu --
+		 * otherwise, if we are migrated and replaced by a different
+		 * task in the same mm just before, during, or after
+		 * membarrier, we will end up with some thread in the mm
+		 * running without a core sync.
+		 *
+		 * For RSEQ, don't rseq_preempt() the caller.  User code
+		 * is not supposed to issue syscalls at all from inside an
+		 * rseq critical section.
+		 */
+		if (flags != MEMBARRIER_FLAG_SYNC_CORE) {
+			preempt_disable();
+			smp_call_function_many(tmpmask, ipi_func, NULL, true);
+			preempt_enable();
+		} else {
+			on_each_cpu_mask(tmpmask, ipi_func, NULL, true);
+		}
+	}
 
-	free_cpumask_var(tmpmask);
+out:
+	if (cpu_id < 0)
+		free_cpumask_var(tmpmask);
 	cpus_read_unlock();
 
 	/*
@@ -248,7 +316,7 @@
 
 	/*
 	 * For each cpu runqueue, if the task's mm match @mm, ensure that all
-	 * @mm's membarrier state set bits are also set in in the runqueue's
+	 * @mm's membarrier state set bits are also set in the runqueue's
 	 * membarrier state. This ensures that a runqueue scheduling
 	 * between threads which are users of @mm has its membarrier state
 	 * updated.
@@ -300,11 +368,18 @@
 	    set_state = MEMBARRIER_STATE_PRIVATE_EXPEDITED,
 	    ret;
 
-	if (flags & MEMBARRIER_FLAG_SYNC_CORE) {
+	if (flags == MEMBARRIER_FLAG_SYNC_CORE) {
 		if (!IS_ENABLED(CONFIG_ARCH_HAS_MEMBARRIER_SYNC_CORE))
 			return -EINVAL;
 		ready_state =
 			MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY;
+	} else if (flags == MEMBARRIER_FLAG_RSEQ) {
+		if (!IS_ENABLED(CONFIG_RSEQ))
+			return -EINVAL;
+		ready_state =
+			MEMBARRIER_STATE_PRIVATE_EXPEDITED_RSEQ_READY;
+	} else {
+		WARN_ON_ONCE(flags);
 	}
 
 	/*
@@ -316,6 +391,8 @@
 		return 0;
 	if (flags & MEMBARRIER_FLAG_SYNC_CORE)
 		set_state |= MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE;
+	if (flags & MEMBARRIER_FLAG_RSEQ)
+		set_state |= MEMBARRIER_STATE_PRIVATE_EXPEDITED_RSEQ;
 	atomic_or(set_state, &mm->membarrier_state);
 	ret = sync_runqueues_membarrier_state(mm);
 	if (ret)
@@ -327,8 +404,15 @@
 
 /**
  * sys_membarrier - issue memory barriers on a set of threads
- * @cmd:   Takes command values defined in enum membarrier_cmd.
- * @flags: Currently needs to be 0. For future extensions.
+ * @cmd:    Takes command values defined in enum membarrier_cmd.
+ * @flags:  Currently needs to be 0 for all commands other than
+ *          MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ: in the latter
+ *          case it can be MEMBARRIER_CMD_FLAG_CPU, indicating that @cpu_id
+ *          contains the CPU on which to interrupt (= restart)
+ *          the RSEQ critical section.
+ * @cpu_id: if @flags == MEMBARRIER_CMD_FLAG_CPU, indicates the cpu on which
+ *          RSEQ CS should be interrupted (@cmd must be
+ *          MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ).
  *
  * If this system call is not implemented, -ENOSYS is returned. If the
  * command specified does not exist, not available on the running
@@ -354,10 +438,21 @@
  *        smp_mb()           X           O            O
  *        sys_membarrier()   O           O            O
  */
-SYSCALL_DEFINE2(membarrier, int, cmd, int, flags)
+SYSCALL_DEFINE3(membarrier, int, cmd, unsigned int, flags, int, cpu_id)
 {
-	if (unlikely(flags))
-		return -EINVAL;
+	switch (cmd) {
+	case MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ:
+		if (unlikely(flags && flags != MEMBARRIER_CMD_FLAG_CPU))
+			return -EINVAL;
+		break;
+	default:
+		if (unlikely(flags))
+			return -EINVAL;
+	}
+
+	if (!(flags & MEMBARRIER_CMD_FLAG_CPU))
+		cpu_id = -1;
+
 	switch (cmd) {
 	case MEMBARRIER_CMD_QUERY:
 	{
@@ -379,13 +474,17 @@
 	case MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED:
 		return membarrier_register_global_expedited();
 	case MEMBARRIER_CMD_PRIVATE_EXPEDITED:
-		return membarrier_private_expedited(0);
+		return membarrier_private_expedited(0, cpu_id);
 	case MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED:
 		return membarrier_register_private_expedited(0);
 	case MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE:
-		return membarrier_private_expedited(MEMBARRIER_FLAG_SYNC_CORE);
+		return membarrier_private_expedited(MEMBARRIER_FLAG_SYNC_CORE, cpu_id);
 	case MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE:
 		return membarrier_register_private_expedited(MEMBARRIER_FLAG_SYNC_CORE);
+	case MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ:
+		return membarrier_private_expedited(MEMBARRIER_FLAG_RSEQ, cpu_id);
+	case MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ:
+		return membarrier_register_private_expedited(MEMBARRIER_FLAG_RSEQ);
 	default:
 		return -EINVAL;
 	}
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index a96db50..2c613e1 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -28,8 +28,6 @@
 #include "sched.h"
 #include "pelt.h"
 
-#include <trace/events/sched.h>
-
 /*
  * Approximate:
  *   val * y^n,    where y^32 ~= 0.5 (~1 scheduling period)
@@ -83,8 +81,6 @@
 	return c1 + c2 + c3;
 }
 
-#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
-
 /*
  * Accumulate the three separate parts of the sum; d1 the remainder
  * of the last (incomplete) period, d2 the span of full periods and d3
@@ -121,23 +117,35 @@
 	 */
 	if (periods) {
 		sa->load_sum = decay_load(sa->load_sum, periods);
-		sa->runnable_load_sum =
-			decay_load(sa->runnable_load_sum, periods);
+		sa->runnable_sum =
+			decay_load(sa->runnable_sum, periods);
 		sa->util_sum = decay_load((u64)(sa->util_sum), periods);
 
 		/*
 		 * Step 2
 		 */
 		delta %= 1024;
-		contrib = __accumulate_pelt_segments(periods,
-				1024 - sa->period_contrib, delta);
+		if (load) {
+			/*
+			 * This relies on the:
+			 *
+			 * if (!load)
+			 *	runnable = running = 0;
+			 *
+			 * clause from ___update_load_sum(); this results in
+			 * the below usage of @contrib to dissapear entirely,
+			 * so no point in calculating it.
+			 */
+			contrib = __accumulate_pelt_segments(periods,
+					1024 - sa->period_contrib, delta);
+		}
 	}
 	sa->period_contrib = delta;
 
 	if (load)
 		sa->load_sum += load * contrib;
 	if (runnable)
-		sa->runnable_load_sum += runnable * contrib;
+		sa->runnable_sum += runnable * contrib << SCHED_CAPACITY_SHIFT;
 	if (running)
 		sa->util_sum += contrib << SCHED_CAPACITY_SHIFT;
 
@@ -205,7 +213,9 @@
 	 * This means that weight will be 0 but not running for a sched_entity
 	 * but also for a cfs_rq if the latter becomes idle. As an example,
 	 * this happens during idle_balance() which calls
-	 * update_blocked_averages()
+	 * update_blocked_averages().
+	 *
+	 * Also see the comment in accumulate_sum().
 	 */
 	if (!load)
 		runnable = running = 0;
@@ -223,16 +233,40 @@
 	return 1;
 }
 
+/*
+ * When syncing *_avg with *_sum, we must take into account the current
+ * position in the PELT segment otherwise the remaining part of the segment
+ * will be considered as idle time whereas it's not yet elapsed and this will
+ * generate unwanted oscillation in the range [1002..1024[.
+ *
+ * The max value of *_sum varies with the position in the time segment and is
+ * equals to :
+ *
+ *   LOAD_AVG_MAX*y + sa->period_contrib
+ *
+ * which can be simplified into:
+ *
+ *   LOAD_AVG_MAX - 1024 + sa->period_contrib
+ *
+ * because LOAD_AVG_MAX*y == LOAD_AVG_MAX-1024
+ *
+ * The same care must be taken when a sched entity is added, updated or
+ * removed from a cfs_rq and we need to update sched_avg. Scheduler entities
+ * and the cfs rq, to which they are attached, have the same position in the
+ * time segment because they use the same clock. This means that we can use
+ * the period_contrib of cfs_rq when updating the sched_avg of a sched_entity
+ * if it's more convenient.
+ */
 static __always_inline void
-___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runnable)
+___update_load_avg(struct sched_avg *sa, unsigned long load)
 {
-	u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib;
+	u32 divider = get_pelt_divider(sa);
 
 	/*
 	 * Step 2: update *_avg.
 	 */
 	sa->load_avg = div_u64(load * sa->load_sum, divider);
-	sa->runnable_load_avg =	div_u64(runnable * sa->runnable_load_sum, divider);
+	sa->runnable_avg = div_u64(sa->runnable_sum, divider);
 	WRITE_ONCE(sa->util_avg, sa->util_sum / divider);
 }
 
@@ -240,33 +274,32 @@
  * sched_entity:
  *
  *   task:
- *     se_runnable() == se_weight()
+ *     se_weight()   = se->load.weight
+ *     se_runnable() = !!on_rq
  *
  *   group: [ see update_cfs_group() ]
  *     se_weight()   = tg->weight * grq->load_avg / tg->load_avg
- *     se_runnable() = se_weight(se) * grq->runnable_load_avg / grq->load_avg
+ *     se_runnable() = grq->h_nr_running
  *
- *   load_sum := runnable_sum
- *   load_avg = se_weight(se) * runnable_avg
+ *   runnable_sum = se_runnable() * runnable = grq->runnable_sum
+ *   runnable_avg = runnable_sum
  *
- *   runnable_load_sum := runnable_sum
- *   runnable_load_avg = se_runnable(se) * runnable_avg
- *
- * XXX collapse load_sum and runnable_load_sum
+ *   load_sum := runnable
+ *   load_avg = se_weight(se) * load_sum
  *
  * cfq_rq:
  *
+ *   runnable_sum = \Sum se->avg.runnable_sum
+ *   runnable_avg = \Sum se->avg.runnable_avg
+ *
  *   load_sum = \Sum se_weight(se) * se->avg.load_sum
  *   load_avg = \Sum se->avg.load_avg
- *
- *   runnable_load_sum = \Sum se_runnable(se) * se->avg.runnable_load_sum
- *   runnable_load_avg = \Sum se->avg.runable_load_avg
  */
 
 int __update_load_avg_blocked_se(u64 now, struct sched_entity *se)
 {
 	if (___update_load_sum(now, &se->avg, 0, 0, 0)) {
-		___update_load_avg(&se->avg, se_weight(se), se_runnable(se));
+		___update_load_avg(&se->avg, se_weight(se));
 		trace_pelt_se_tp(se);
 		return 1;
 	}
@@ -276,10 +309,10 @@
 
 int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-	if (___update_load_sum(now, &se->avg, !!se->on_rq, !!se->on_rq,
+	if (___update_load_sum(now, &se->avg, !!se->on_rq, se_runnable(se),
 				cfs_rq->curr == se)) {
 
-		___update_load_avg(&se->avg, se_weight(se), se_runnable(se));
+		___update_load_avg(&se->avg, se_weight(se));
 		cfs_se_util_change(&se->avg);
 		trace_pelt_se_tp(se);
 		return 1;
@@ -292,10 +325,10 @@
 {
 	if (___update_load_sum(now, &cfs_rq->avg,
 				scale_load_down(cfs_rq->load.weight),
-				scale_load_down(cfs_rq->runnable_weight),
+				cfs_rq->h_nr_running,
 				cfs_rq->curr != NULL)) {
 
-		___update_load_avg(&cfs_rq->avg, 1, 1);
+		___update_load_avg(&cfs_rq->avg, 1);
 		trace_pelt_cfs_tp(cfs_rq);
 		return 1;
 	}
@@ -308,9 +341,9 @@
  *
  *   util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
  *   util_sum = cpu_scale * load_sum
- *   runnable_load_sum = load_sum
+ *   runnable_sum = util_sum
  *
- *   load_avg and runnable_load_avg are not supported and meaningless.
+ *   load_avg and runnable_avg are not supported and meaningless.
  *
  */
 
@@ -321,7 +354,7 @@
 				running,
 				running)) {
 
-		___update_load_avg(&rq->avg_rt, 1, 1);
+		___update_load_avg(&rq->avg_rt, 1);
 		trace_pelt_rt_tp(rq);
 		return 1;
 	}
@@ -334,7 +367,9 @@
  *
  *   util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
  *   util_sum = cpu_scale * load_sum
- *   runnable_load_sum = load_sum
+ *   runnable_sum = util_sum
+ *
+ *   load_avg and runnable_avg are not supported and meaningless.
  *
  */
 
@@ -345,7 +380,7 @@
 				running,
 				running)) {
 
-		___update_load_avg(&rq->avg_dl, 1, 1);
+		___update_load_avg(&rq->avg_dl, 1);
 		trace_pelt_dl_tp(rq);
 		return 1;
 	}
@@ -353,13 +388,46 @@
 	return 0;
 }
 
+#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+/*
+ * thermal:
+ *
+ *   load_sum = \Sum se->avg.load_sum but se->avg.load_sum is not tracked
+ *
+ *   util_avg and runnable_load_avg are not supported and meaningless.
+ *
+ * Unlike rt/dl utilization tracking that track time spent by a cpu
+ * running a rt/dl task through util_avg, the average thermal pressure is
+ * tracked through load_avg. This is because thermal pressure signal is
+ * time weighted "delta" capacity unlike util_avg which is binary.
+ * "delta capacity" =  actual capacity  -
+ *			capped capacity a cpu due to a thermal event.
+ */
+
+int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+{
+	if (___update_load_sum(now, &rq->avg_thermal,
+			       capacity,
+			       capacity,
+			       capacity)) {
+		___update_load_avg(&rq->avg_thermal, 1);
+		trace_pelt_thermal_tp(rq);
+		return 1;
+	}
+
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
 /*
  * irq:
  *
  *   util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
  *   util_sum = cpu_scale * load_sum
- *   runnable_load_sum = load_sum
+ *   runnable_sum = util_sum
+ *
+ *   load_avg and runnable_avg are not supported and meaningless.
  *
  */
 
@@ -396,7 +464,7 @@
 				1);
 
 	if (ret) {
-		___update_load_avg(&rq->avg_irq, 1, 1);
+		___update_load_avg(&rq->avg_irq, 1);
 		trace_pelt_irq_tp(rq);
 	}
 
diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h
index afff644..45bf08e 100644
--- a/kernel/sched/pelt.h
+++ b/kernel/sched/pelt.h
@@ -7,6 +7,26 @@
 int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
 int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
 
+#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity);
+
+static inline u64 thermal_load_avg(struct rq *rq)
+{
+	return READ_ONCE(rq->avg_thermal.load_avg);
+}
+#else
+static inline int
+update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+{
+	return 0;
+}
+
+static inline u64 thermal_load_avg(struct rq *rq)
+{
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
 int update_irq_load_avg(struct rq *rq, u64 running);
 #else
@@ -17,14 +37,12 @@
 }
 #endif
 
-/*
- * When a task is dequeued, its estimated utilization should not be update if
- * its util_avg has not been updated at least once.
- * This flag is used to synchronize util_avg updates with util_est updates.
- * We map this information into the LSB bit of the utilization saved at
- * dequeue time (i.e. util_est.dequeued).
- */
-#define UTIL_AVG_UNCHANGED 0x1
+#define PELT_MIN_DIVIDER	(LOAD_AVG_MAX - 1024)
+
+static inline u32 get_pelt_divider(struct sched_avg *avg)
+{
+	return PELT_MIN_DIVIDER + avg->period_contrib;
+}
 
 static inline void cfs_se_util_change(struct sched_avg *avg)
 {
@@ -33,7 +51,7 @@
 	if (!sched_feat(UTIL_EST))
 		return;
 
-	/* Avoid store if the flag has been already set */
+	/* Avoid store if the flag has been already reset */
 	enqueued = avg->util_est.enqueued;
 	if (!(enqueued & UTIL_AVG_UNCHANGED))
 		return;
@@ -159,6 +177,17 @@
 }
 
 static inline int
+update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+{
+	return 0;
+}
+
+static inline u64 thermal_load_avg(struct rq *rq)
+{
+	return 0;
+}
+
+static inline int
 update_irq_load_avg(struct rq *rq, u64 running)
 {
 	return 0;
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 9154e74..b7f38f3 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -179,6 +179,8 @@
 
 static void psi_avgs_work(struct work_struct *work);
 
+static void poll_timer_fn(struct timer_list *t);
+
 static void group_init(struct psi_group *group)
 {
 	int cpu;
@@ -190,7 +192,6 @@
 	INIT_DELAYED_WORK(&group->avgs_work, psi_avgs_work);
 	mutex_init(&group->avgs_lock);
 	/* Init trigger-related members */
-	atomic_set(&group->poll_scheduled, 0);
 	mutex_init(&group->trigger_lock);
 	INIT_LIST_HEAD(&group->triggers);
 	memset(group->nr_triggers, 0, sizeof(group->nr_triggers));
@@ -199,7 +200,9 @@
 	memset(group->polling_total, 0, sizeof(group->polling_total));
 	group->polling_next_update = ULLONG_MAX;
 	group->polling_until = 0;
-	rcu_assign_pointer(group->poll_kworker, NULL);
+	init_waitqueue_head(&group->poll_wait);
+	timer_setup(&group->poll_timer, poll_timer_fn, 0);
+	rcu_assign_pointer(group->poll_task, NULL);
 }
 
 void __init psi_init(void)
@@ -225,7 +228,7 @@
 	case PSI_MEM_FULL:
 		return tasks[NR_MEMSTALL] && !tasks[NR_RUNNING];
 	case PSI_CPU_SOME:
-		return tasks[NR_RUNNING] > 1;
+		return tasks[NR_RUNNING] > tasks[NR_ONCPU];
 	case PSI_NONIDLE:
 		return tasks[NR_IOWAIT] || tasks[NR_MEMSTALL] ||
 			tasks[NR_RUNNING];
@@ -547,47 +550,38 @@
 	return now + group->poll_min_period;
 }
 
-/*
- * Schedule polling if it's not already scheduled. It's safe to call even from
- * hotpath because even though kthread_queue_delayed_work takes worker->lock
- * spinlock that spinlock is never contended due to poll_scheduled atomic
- * preventing such competition.
- */
+/* Schedule polling if it's not already scheduled. */
 static void psi_schedule_poll_work(struct psi_group *group, unsigned long delay)
 {
-	struct kthread_worker *kworker;
+	struct task_struct *task;
 
-	/* Do not reschedule if already scheduled */
-	if (atomic_cmpxchg(&group->poll_scheduled, 0, 1) != 0)
+	/*
+	 * Do not reschedule if already scheduled.
+	 * Possible race with a timer scheduled after this check but before
+	 * mod_timer below can be tolerated because group->polling_next_update
+	 * will keep updates on schedule.
+	 */
+	if (timer_pending(&group->poll_timer))
 		return;
 
 	rcu_read_lock();
 
-	kworker = rcu_dereference(group->poll_kworker);
+	task = rcu_dereference(group->poll_task);
 	/*
 	 * kworker might be NULL in case psi_trigger_destroy races with
 	 * psi_task_change (hotpath) which can't use locks
 	 */
-	if (likely(kworker))
-		kthread_queue_delayed_work(kworker, &group->poll_work, delay);
-	else
-		atomic_set(&group->poll_scheduled, 0);
+	if (likely(task))
+		mod_timer(&group->poll_timer, jiffies + delay);
 
 	rcu_read_unlock();
 }
 
-static void psi_poll_work(struct kthread_work *work)
+static void psi_poll_work(struct psi_group *group)
 {
-	struct kthread_delayed_work *dwork;
-	struct psi_group *group;
 	u32 changed_states;
 	u64 now;
 
-	dwork = container_of(work, struct kthread_delayed_work, work);
-	group = container_of(dwork, struct psi_group, poll_work);
-
-	atomic_set(&group->poll_scheduled, 0);
-
 	mutex_lock(&group->trigger_lock);
 
 	now = sched_clock();
@@ -623,6 +617,32 @@
 	mutex_unlock(&group->trigger_lock);
 }
 
+static int psi_poll_worker(void *data)
+{
+	struct psi_group *group = (struct psi_group *)data;
+
+	sched_set_fifo_low(current);
+
+	while (true) {
+		wait_event_interruptible(group->poll_wait,
+				atomic_cmpxchg(&group->poll_wakeup, 1, 0) ||
+				kthread_should_stop());
+		if (kthread_should_stop())
+			break;
+
+		psi_poll_work(group);
+	}
+	return 0;
+}
+
+static void poll_timer_fn(struct timer_list *t)
+{
+	struct psi_group *group = from_timer(group, t, poll_timer);
+
+	atomic_set(&group->poll_wakeup, 1);
+	wake_up_interruptible(&group->poll_wait);
+}
+
 static void record_times(struct psi_group_cpu *groupc, int cpu,
 			 bool memstall_tick)
 {
@@ -669,13 +689,14 @@
 		groupc->times[PSI_NONIDLE] += delta;
 }
 
-static u32 psi_group_change(struct psi_group *group, int cpu,
-			    unsigned int clear, unsigned int set)
+static void psi_group_change(struct psi_group *group, int cpu,
+			     unsigned int clear, unsigned int set,
+			     bool wake_clock)
 {
 	struct psi_group_cpu *groupc;
+	u32 state_mask = 0;
 	unsigned int t, m;
 	enum psi_states s;
-	u32 state_mask = 0;
 
 	groupc = per_cpu_ptr(group->pcpu, cpu);
 
@@ -694,14 +715,15 @@
 	for (t = 0, m = clear; m; m &= ~(1 << t), t++) {
 		if (!(m & (1 << t)))
 			continue;
-		if (groupc->tasks[t] == 0 && !psi_bug) {
-			printk_deferred(KERN_ERR "psi: task underflow! cpu=%d t=%d tasks=[%u %u %u] clear=%x set=%x\n",
+		if (groupc->tasks[t]) {
+			groupc->tasks[t]--;
+		} else if (!psi_bug) {
+			printk_deferred(KERN_ERR "psi: task underflow! cpu=%d t=%d tasks=[%u %u %u %u] clear=%x set=%x\n",
 					cpu, t, groupc->tasks[0],
 					groupc->tasks[1], groupc->tasks[2],
-					clear, set);
+					groupc->tasks[3], clear, set);
 			psi_bug = 1;
 		}
-		groupc->tasks[t]--;
 	}
 
 	for (t = 0; set; set &= ~(1 << t), t++)
@@ -717,7 +739,11 @@
 
 	write_seqcount_end(&groupc->seq);
 
-	return state_mask;
+	if (state_mask & group->poll_states)
+		psi_schedule_poll_work(group, 1);
+
+	if (wake_clock && !delayed_work_pending(&group->avgs_work))
+		schedule_delayed_work(&group->avgs_work, PSI_FREQ);
 }
 
 static struct psi_group *iterate_groups(struct task_struct *task, void **iter)
@@ -744,6 +770,21 @@
 	return &psi_system;
 }
 
+static void psi_flags_change(struct task_struct *task, int clear, int set)
+{
+	if (((task->psi_flags & set) ||
+	     (task->psi_flags & clear) != clear) &&
+	    !psi_bug) {
+		printk_deferred(KERN_ERR "psi: inconsistent task state! task=%d:%s cpu=%d psi_flags=%x clear=%x set=%x\n",
+				task->pid, task->comm, task_cpu(task),
+				task->psi_flags, clear, set);
+		psi_bug = 1;
+	}
+
+	task->psi_flags &= ~clear;
+	task->psi_flags |= set;
+}
+
 void psi_task_change(struct task_struct *task, int clear, int set)
 {
 	int cpu = task_cpu(task);
@@ -754,17 +795,7 @@
 	if (!task->pid)
 		return;
 
-	if (((task->psi_flags & set) ||
-	     (task->psi_flags & clear) != clear) &&
-	    !psi_bug) {
-		printk_deferred(KERN_ERR "psi: inconsistent task state! task=%d:%s cpu=%d psi_flags=%x clear=%x set=%x\n",
-				task->pid, task->comm, cpu,
-				task->psi_flags, clear, set);
-		psi_bug = 1;
-	}
-
-	task->psi_flags &= ~clear;
-	task->psi_flags |= set;
+	psi_flags_change(task, clear, set);
 
 	/*
 	 * Periodic aggregation shuts off if there is a period of no
@@ -777,14 +808,51 @@
 		     wq_worker_last_func(task) == psi_avgs_work))
 		wake_clock = false;
 
-	while ((group = iterate_groups(task, &iter))) {
-		u32 state_mask = psi_group_change(group, cpu, clear, set);
+	while ((group = iterate_groups(task, &iter)))
+		psi_group_change(group, cpu, clear, set, wake_clock);
+}
 
-		if (state_mask & group->poll_states)
-			psi_schedule_poll_work(group, 1);
+void psi_task_switch(struct task_struct *prev, struct task_struct *next,
+		     bool sleep)
+{
+	struct psi_group *group, *common = NULL;
+	int cpu = task_cpu(prev);
+	void *iter;
 
-		if (wake_clock && !delayed_work_pending(&group->avgs_work))
-			schedule_delayed_work(&group->avgs_work, PSI_FREQ);
+	if (next->pid) {
+		psi_flags_change(next, 0, TSK_ONCPU);
+		/*
+		 * When moving state between tasks, the group that
+		 * contains them both does not change: we can stop
+		 * updating the tree once we reach the first common
+		 * ancestor. Iterate @next's ancestors until we
+		 * encounter @prev's state.
+		 */
+		iter = NULL;
+		while ((group = iterate_groups(next, &iter))) {
+			if (per_cpu_ptr(group->pcpu, cpu)->tasks[NR_ONCPU]) {
+				common = group;
+				break;
+			}
+
+			psi_group_change(group, cpu, 0, TSK_ONCPU, true);
+		}
+	}
+
+	/*
+	 * If this is a voluntary sleep, dequeue will have taken care
+	 * of the outgoing TSK_ONCPU alongside TSK_RUNNING already. We
+	 * only need to deal with it during preemption.
+	 */
+	if (sleep)
+		return;
+
+	if (prev->pid) {
+		psi_flags_change(prev, TSK_ONCPU, 0);
+
+		iter = NULL;
+		while ((group = iterate_groups(prev, &iter)) && group != common)
+			psi_group_change(group, cpu, TSK_ONCPU, 0, true);
 	}
 }
 
@@ -818,17 +886,17 @@
 	if (static_branch_likely(&psi_disabled))
 		return;
 
-	*flags = current->flags & PF_MEMSTALL;
+	*flags = current->in_memstall;
 	if (*flags)
 		return;
 	/*
-	 * PF_MEMSTALL setting & accounting needs to be atomic wrt
+	 * in_memstall setting & accounting needs to be atomic wrt
 	 * changes to the task's scheduling state, otherwise we can
 	 * race with CPU migration.
 	 */
 	rq = this_rq_lock_irq(&rf);
 
-	current->flags |= PF_MEMSTALL;
+	current->in_memstall = 1;
 	psi_task_change(current, 0, TSK_MEMSTALL);
 
 	rq_unlock_irq(rq, &rf);
@@ -851,13 +919,13 @@
 	if (*flags)
 		return;
 	/*
-	 * PF_MEMSTALL clearing & accounting needs to be atomic wrt
+	 * in_memstall clearing & accounting needs to be atomic wrt
 	 * changes to the task's scheduling state, otherwise we could
 	 * race with CPU migration.
 	 */
 	rq = this_rq_lock_irq(&rf);
 
-	current->flags &= ~PF_MEMSTALL;
+	current->in_memstall = 0;
 	psi_task_change(current, TSK_MEMSTALL, 0);
 
 	rq_unlock_irq(rq, &rf);
@@ -916,12 +984,14 @@
 
 	rq = task_rq_lock(task, &rf);
 
-	if (task_on_rq_queued(task))
+	if (task_on_rq_queued(task)) {
 		task_flags = TSK_RUNNING;
-	else if (task->in_iowait)
+		if (task_current(rq, task))
+			task_flags |= TSK_ONCPU;
+	} else if (task->in_iowait)
 		task_flags = TSK_IOWAIT;
 
-	if (task->flags & PF_MEMSTALL)
+	if (task->in_memstall)
 		task_flags |= TSK_MEMSTALL;
 
 	if (task_flags)
@@ -1046,26 +1116,21 @@
 	t->event = 0;
 	t->last_event_time = 0;
 	init_waitqueue_head(&t->event_wait);
-	kref_init(&t->refcount);
 
 	mutex_lock(&group->trigger_lock);
 
-	if (!rcu_access_pointer(group->poll_kworker)) {
-		struct sched_param param = {
-			.sched_priority = 1,
-		};
-		struct kthread_worker *kworker;
+	if (!rcu_access_pointer(group->poll_task)) {
+		struct task_struct *task;
 
-		kworker = kthread_create_worker(0, "psimon");
-		if (IS_ERR(kworker)) {
+		task = kthread_create(psi_poll_worker, group, "psimon");
+		if (IS_ERR(task)) {
 			kfree(t);
 			mutex_unlock(&group->trigger_lock);
-			return ERR_CAST(kworker);
+			return ERR_CAST(task);
 		}
-		sched_setscheduler_nocheck(kworker->task, SCHED_FIFO, &param);
-		kthread_init_delayed_work(&group->poll_work,
-				psi_poll_work);
-		rcu_assign_pointer(group->poll_kworker, kworker);
+		atomic_set(&group->poll_wakeup, 0);
+		wake_up_process(task);
+		rcu_assign_pointer(group->poll_task, task);
 	}
 
 	list_add(&t->node, &group->triggers);
@@ -1079,15 +1144,19 @@
 	return t;
 }
 
-static void psi_trigger_destroy(struct kref *ref)
+void psi_trigger_destroy(struct psi_trigger *t)
 {
-	struct psi_trigger *t = container_of(ref, struct psi_trigger, refcount);
-	struct psi_group *group = t->group;
-	struct kthread_worker *kworker_to_destroy = NULL;
+	struct psi_group *group;
+	struct task_struct *task_to_destroy = NULL;
 
-	if (static_branch_likely(&psi_disabled))
+	/*
+	 * We do not check psi_disabled since it might have been disabled after
+	 * the trigger got created.
+	 */
+	if (!t)
 		return;
 
+	group = t->group;
 	/*
 	 * Wakeup waiters to stop polling. Can happen if cgroup is deleted
 	 * from under a polling process.
@@ -1109,55 +1178,39 @@
 			period = min(period, div_u64(tmp->win.size,
 					UPDATES_PER_WINDOW));
 		group->poll_min_period = period;
-		/* Destroy poll_kworker when the last trigger is destroyed */
+		/* Destroy poll_task when the last trigger is destroyed */
 		if (group->poll_states == 0) {
 			group->polling_until = 0;
-			kworker_to_destroy = rcu_dereference_protected(
-					group->poll_kworker,
+			task_to_destroy = rcu_dereference_protected(
+					group->poll_task,
 					lockdep_is_held(&group->trigger_lock));
-			rcu_assign_pointer(group->poll_kworker, NULL);
+			rcu_assign_pointer(group->poll_task, NULL);
+			del_timer(&group->poll_timer);
 		}
 	}
 
 	mutex_unlock(&group->trigger_lock);
 
 	/*
-	 * Wait for both *trigger_ptr from psi_trigger_replace and
-	 * poll_kworker RCUs to complete their read-side critical sections
-	 * before destroying the trigger and optionally the poll_kworker
+	 * Wait for psi_schedule_poll_work RCU to complete its read-side
+	 * critical section before destroying the trigger and optionally the
+	 * poll_task.
 	 */
 	synchronize_rcu();
 	/*
-	 * Destroy the kworker after releasing trigger_lock to prevent a
+	 * Stop kthread 'psimon' after releasing trigger_lock to prevent a
 	 * deadlock while waiting for psi_poll_work to acquire trigger_lock
 	 */
-	if (kworker_to_destroy) {
+	if (task_to_destroy) {
 		/*
 		 * After the RCU grace period has expired, the worker
-		 * can no longer be found through group->poll_kworker.
-		 * But it might have been already scheduled before
-		 * that - deschedule it cleanly before destroying it.
+		 * can no longer be found through group->poll_task.
 		 */
-		kthread_cancel_delayed_work_sync(&group->poll_work);
-		atomic_set(&group->poll_scheduled, 0);
-
-		kthread_destroy_worker(kworker_to_destroy);
+		kthread_stop(task_to_destroy);
 	}
 	kfree(t);
 }
 
-void psi_trigger_replace(void **trigger_ptr, struct psi_trigger *new)
-{
-	struct psi_trigger *old = *trigger_ptr;
-
-	if (static_branch_likely(&psi_disabled))
-		return;
-
-	rcu_assign_pointer(*trigger_ptr, new);
-	if (old)
-		kref_put(&old->refcount, psi_trigger_destroy);
-}
-
 __poll_t psi_trigger_poll(void **trigger_ptr,
 				struct file *file, poll_table *wait)
 {
@@ -1167,24 +1220,15 @@
 	if (static_branch_likely(&psi_disabled))
 		return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI;
 
-	rcu_read_lock();
-
-	t = rcu_dereference(*(void __rcu __force **)trigger_ptr);
-	if (!t) {
-		rcu_read_unlock();
+	t = smp_load_acquire(trigger_ptr);
+	if (!t)
 		return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI;
-	}
-	kref_get(&t->refcount);
-
-	rcu_read_unlock();
 
 	poll_wait(file, &t->event_wait, wait);
 
 	if (cmpxchg(&t->event, 1, 0) == 1)
 		ret |= EPOLLPRI;
 
-	kref_put(&t->refcount, psi_trigger_destroy);
-
 	return ret;
 }
 
@@ -1208,14 +1252,24 @@
 
 	buf[buf_size - 1] = '\0';
 
-	new = psi_trigger_create(&psi_system, buf, nbytes, res);
-	if (IS_ERR(new))
-		return PTR_ERR(new);
-
 	seq = file->private_data;
+
 	/* Take seq->lock to protect seq->private from concurrent writes */
 	mutex_lock(&seq->lock);
-	psi_trigger_replace(&seq->private, new);
+
+	/* Allow only one trigger per file descriptor */
+	if (seq->private) {
+		mutex_unlock(&seq->lock);
+		return -EBUSY;
+	}
+
+	new = psi_trigger_create(&psi_system, buf, nbytes, res);
+	if (IS_ERR(new)) {
+		mutex_unlock(&seq->lock);
+		return PTR_ERR(new);
+	}
+
+	smp_store_release(&seq->private, new);
 	mutex_unlock(&seq->lock);
 
 	return nbytes;
@@ -1250,43 +1304,45 @@
 {
 	struct seq_file *seq = file->private_data;
 
-	psi_trigger_replace(&seq->private, NULL);
+	psi_trigger_destroy(seq->private);
 	return single_release(inode, file);
 }
 
-static const struct file_operations psi_io_fops = {
-	.open           = psi_io_open,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.write          = psi_io_write,
-	.poll           = psi_fop_poll,
-	.release        = psi_fop_release,
+static const struct proc_ops psi_io_proc_ops = {
+	.proc_open	= psi_io_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_write	= psi_io_write,
+	.proc_poll	= psi_fop_poll,
+	.proc_release	= psi_fop_release,
 };
 
-static const struct file_operations psi_memory_fops = {
-	.open           = psi_memory_open,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.write          = psi_memory_write,
-	.poll           = psi_fop_poll,
-	.release        = psi_fop_release,
+static const struct proc_ops psi_memory_proc_ops = {
+	.proc_open	= psi_memory_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_write	= psi_memory_write,
+	.proc_poll	= psi_fop_poll,
+	.proc_release	= psi_fop_release,
 };
 
-static const struct file_operations psi_cpu_fops = {
-	.open           = psi_cpu_open,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.write          = psi_cpu_write,
-	.poll           = psi_fop_poll,
-	.release        = psi_fop_release,
+static const struct proc_ops psi_cpu_proc_ops = {
+	.proc_open	= psi_cpu_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_write	= psi_cpu_write,
+	.proc_poll	= psi_fop_poll,
+	.proc_release	= psi_fop_release,
 };
 
 static int __init psi_proc_init(void)
 {
-	proc_mkdir("pressure", NULL);
-	proc_create("pressure/io", 0, NULL, &psi_io_fops);
-	proc_create("pressure/memory", 0, NULL, &psi_memory_fops);
-	proc_create("pressure/cpu", 0, NULL, &psi_cpu_fops);
+	if (psi_enable) {
+		proc_mkdir("pressure", NULL);
+		proc_create("pressure/io", 0, NULL, &psi_io_proc_ops);
+		proc_create("pressure/memory", 0, NULL, &psi_memory_proc_ops);
+		proc_create("pressure/cpu", 0, NULL, &psi_cpu_proc_ops);
+	}
 	return 0;
 }
 module_init(psi_proc_init);
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 2dffb87..41b14d9 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -52,11 +52,8 @@
 	rt_b->rt_period_timer.function = sched_rt_period_timer;
 }
 
-static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
+static inline void do_start_rt_bandwidth(struct rt_bandwidth *rt_b)
 {
-	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
-		return;
-
 	raw_spin_lock(&rt_b->rt_runtime_lock);
 	if (!rt_b->rt_period_active) {
 		rt_b->rt_period_active = 1;
@@ -75,6 +72,14 @@
 	raw_spin_unlock(&rt_b->rt_runtime_lock);
 }
 
+static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
+{
+	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
+		return;
+
+	do_start_rt_bandwidth(rt_b);
+}
+
 void init_rt_rq(struct rt_rq *rt_rq)
 {
 	struct rt_prio_array *array;
@@ -439,6 +444,45 @@
 	return rt_se->on_rq;
 }
 
+#ifdef CONFIG_UCLAMP_TASK
+/*
+ * Verify the fitness of task @p to run on @cpu taking into account the uclamp
+ * settings.
+ *
+ * This check is only important for heterogeneous systems where uclamp_min value
+ * is higher than the capacity of a @cpu. For non-heterogeneous system this
+ * function will always return true.
+ *
+ * The function will return true if the capacity of the @cpu is >= the
+ * uclamp_min and false otherwise.
+ *
+ * Note that uclamp_min will be clamped to uclamp_max if uclamp_min
+ * > uclamp_max.
+ */
+static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu)
+{
+	unsigned int min_cap;
+	unsigned int max_cap;
+	unsigned int cpu_cap;
+
+	/* Only heterogeneous systems can benefit from this check */
+	if (!static_branch_unlikely(&sched_asym_cpucapacity))
+		return true;
+
+	min_cap = uclamp_eff_value(p, UCLAMP_MIN);
+	max_cap = uclamp_eff_value(p, UCLAMP_MAX);
+
+	cpu_cap = capacity_orig_of(cpu);
+
+	return cpu_cap >= min(min_cap, max_cap);
+}
+#else
+static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu)
+{
+	return true;
+}
+#endif
+
 #ifdef CONFIG_RT_GROUP_SCHED
 
 static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
@@ -983,13 +1027,17 @@
 
 	for_each_sched_rt_entity(rt_se) {
 		struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
+		int exceeded;
 
 		if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
 			raw_spin_lock(&rt_rq->rt_runtime_lock);
 			rt_rq->rt_time += delta_exec;
-			if (sched_rt_runtime_exceeded(rt_rq))
+			exceeded = sched_rt_runtime_exceeded(rt_rq);
+			if (exceeded)
 				resched_curr(rq);
 			raw_spin_unlock(&rt_rq->rt_runtime_lock);
+			if (exceeded)
+				do_start_rt_bandwidth(sched_rt_bandwidth(rt_rq));
 		}
 	}
 }
@@ -1393,6 +1441,7 @@
 {
 	struct task_struct *curr;
 	struct rq *rq;
+	bool test;
 
 	/* For anything but wake ups, just return the task_cpu */
 	if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)
@@ -1424,13 +1473,26 @@
 	 *
 	 * This test is optimistic, if we get it wrong the load-balancer
 	 * will have to sort it out.
+	 *
+	 * We take into account the capacity of the CPU to ensure it fits the
+	 * requirement of the task - which is only important on heterogeneous
+	 * systems like big.LITTLE.
 	 */
-	if (curr && unlikely(rt_task(curr)) &&
-	    (curr->nr_cpus_allowed < 2 ||
-	     curr->prio <= p->prio)) {
+	test = curr &&
+	       unlikely(rt_task(curr)) &&
+	       (curr->nr_cpus_allowed < 2 || curr->prio <= p->prio);
+
+	if (test || !rt_task_fits_capacity(p, cpu)) {
 		int target = find_lowest_rq(p);
 
 		/*
+		 * Bail out if we were forcing a migration to find a better
+		 * fitting CPU but our search failed.
+		 */
+		if (!test && target != -1 && !rt_task_fits_capacity(p, target))
+			goto out_unlock;
+
+		/*
 		 * Don't bother moving it if the destination CPU is
 		 * not running a lower priority task.
 		 */
@@ -1438,6 +1500,8 @@
 		    p->prio < cpu_rq(target)->rt.highest_prio.curr)
 			cpu = target;
 	}
+
+out_unlock:
 	rcu_read_unlock();
 
 out:
@@ -1458,8 +1522,8 @@
 	 * p is migratable, so let's not schedule it and
 	 * see if it is pushed or pulled somewhere else.
 	 */
-	if (p->nr_cpus_allowed != 1
-	    && cpupri_find(&rq->rd->cpupri, p, NULL))
+	if (p->nr_cpus_allowed != 1 &&
+	    cpupri_find(&rq->rd->cpupri, p, NULL))
 		return;
 
 	/*
@@ -1569,13 +1633,10 @@
 	return rt_task_of(rt_se);
 }
 
-static struct task_struct *
-pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static struct task_struct *pick_next_task_rt(struct rq *rq)
 {
 	struct task_struct *p;
 
-	WARN_ON_ONCE(prev || rf);
-
 	if (!sched_rt_runnable(rq))
 		return NULL;
 
@@ -1640,6 +1701,7 @@
 	struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask);
 	int this_cpu = smp_processor_id();
 	int cpu      = task_cpu(task);
+	int ret;
 
 	/* Make sure the mask is initialized first */
 	if (unlikely(!lowest_mask))
@@ -1648,7 +1710,22 @@
 	if (task->nr_cpus_allowed == 1)
 		return -1; /* No other targets possible */
 
-	if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
+	/*
+	 * If we're on asym system ensure we consider the different capacities
+	 * of the CPUs when searching for the lowest_mask.
+	 */
+	if (static_branch_unlikely(&sched_asym_cpucapacity)) {
+
+		ret = cpupri_find_fitness(&task_rq(task)->rd->cpupri,
+					  task, lowest_mask,
+					  rt_task_fits_capacity);
+	} else {
+
+		ret = cpupri_find(&task_rq(task)->rd->cpupri,
+				  task, lowest_mask);
+	}
+
+	if (!ret)
 		return -1; /* No targets found */
 
 	/*
@@ -2152,12 +2229,14 @@
  */
 static void task_woken_rt(struct rq *rq, struct task_struct *p)
 {
-	if (!task_running(rq, p) &&
-	    !test_tsk_need_resched(rq->curr) &&
-	    p->nr_cpus_allowed > 1 &&
-	    (dl_task(rq->curr) || rt_task(rq->curr)) &&
-	    (rq->curr->nr_cpus_allowed < 2 ||
-	     rq->curr->prio <= p->prio))
+	bool need_to_push = !task_running(rq, p) &&
+			    !test_tsk_need_resched(rq->curr) &&
+			    p->nr_cpus_allowed > 1 &&
+			    (dl_task(rq->curr) || rt_task(rq->curr)) &&
+			    (rq->curr->nr_cpus_allowed < 2 ||
+			     rq->curr->prio <= p->prio);
+
+	if (need_to_push)
 		push_rt_tasks(rq);
 }
 
@@ -2366,8 +2445,8 @@
 		return 0;
 }
 
-const struct sched_class rt_sched_class = {
-	.next			= &fair_sched_class,
+const struct sched_class rt_sched_class
+	__section("__rt_sched_class") = {
 	.enqueue_task		= enqueue_task_rt,
 	.dequeue_task		= dequeue_task_rt,
 	.yield_task		= yield_task_rt,
@@ -2408,10 +2487,11 @@
  */
 static DEFINE_MUTEX(rt_constraints_mutex);
 
-/* Must be called with tasklist_lock held */
 static inline int tg_has_rt_tasks(struct task_group *tg)
 {
-	struct task_struct *g, *p;
+	struct task_struct *task;
+	struct css_task_iter it;
+	int ret = 0;
 
 	/*
 	 * Autogroups do not have RT tasks; see autogroup_create().
@@ -2419,12 +2499,12 @@
 	if (task_group_is_autogroup(tg))
 		return 0;
 
-	for_each_process_thread(g, p) {
-		if (rt_task(p) && task_group(p) == tg)
-			return 1;
-	}
+	css_task_iter_start(&tg->css, 0, &it);
+	while (!ret && (task = css_task_iter_next(&it)))
+		ret |= rt_task(task);
+	css_task_iter_end(&it);
 
-	return 0;
+	return ret;
 }
 
 struct rt_schedulable_data {
@@ -2455,9 +2535,10 @@
 		return -EINVAL;
 
 	/*
-	 * Ensure we don't starve existing RT tasks.
+	 * Ensure we don't starve existing RT tasks if runtime turns zero.
 	 */
-	if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
+	if (rt_bandwidth_enabled() && !runtime &&
+	    tg->rt_bandwidth.rt_runtime && tg_has_rt_tasks(tg))
 		return -EBUSY;
 
 	total = to_ratio(period, runtime);
@@ -2529,7 +2610,6 @@
 		return -EINVAL;
 
 	mutex_lock(&rt_constraints_mutex);
-	read_lock(&tasklist_lock);
 	err = __rt_schedulable(tg, rt_period, rt_runtime);
 	if (err)
 		goto unlock;
@@ -2547,7 +2627,6 @@
 	}
 	raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
 unlock:
-	read_unlock(&tasklist_lock);
 	mutex_unlock(&rt_constraints_mutex);
 
 	return err;
@@ -2606,9 +2685,7 @@
 	int ret = 0;
 
 	mutex_lock(&rt_constraints_mutex);
-	read_lock(&tasklist_lock);
 	ret = __rt_schedulable(NULL, 0, 0);
-	read_unlock(&tasklist_lock);
 	mutex_unlock(&rt_constraints_mutex);
 
 	return ret;
@@ -2659,13 +2736,16 @@
 
 static void sched_rt_do_global(void)
 {
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
 	def_rt_bandwidth.rt_runtime = global_rt_runtime();
 	def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period());
+	raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
 }
 
-int sched_rt_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+int sched_rt_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int old_period, old_runtime;
 	static DEFINE_MUTEX(mutex);
@@ -2703,9 +2783,8 @@
 	return ret;
 }
 
-int sched_rr_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+int sched_rr_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	static DEFINE_MUTEX(mutex);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index fe755c1..08db8e0 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -67,6 +67,7 @@
 #include <linux/tsacct_kern.h>
 
 #include <asm/tlb.h>
+#include <asm-generic/vmlinux.lds.h>
 
 #ifdef CONFIG_PARAVIRT
 # include <asm/paravirt.h>
@@ -75,6 +76,8 @@
 #include "cpupri.h"
 #include "cpudeadline.h"
 
+#include <trace/events/sched.h>
+
 #ifdef CONFIG_SCHED_DEBUG
 # define SCHED_WARN_ON(x)	WARN_ONCE(x, #x)
 #else
@@ -96,6 +99,7 @@
 extern void calc_global_load_tick(struct rq *this_rq);
 extern long calc_load_fold_active(struct rq *this_rq, long adjust);
 
+extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
 /*
  * Helpers for converting nanosecond timing to jiffy resolution
  */
@@ -195,6 +199,19 @@
 
 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
 
+static inline void update_avg(u64 *avg, u64 sample)
+{
+	s64 diff = sample - *avg;
+	*avg += diff / 8;
+}
+
+/*
+ * Shifting a value by an exponent greater *or equal* to the size of said value
+ * is UB; cap at size-1.
+ */
+#define shr_bound(val, shift)							\
+	(val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1))
+
 /*
  * !! For sched_setattr_nocheck() (kernel) only !!
  *
@@ -300,14 +317,28 @@
 	__dl_update(dl_b, -((s32)tsk_bw / cpus));
 }
 
-static inline
-bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
+static inline bool __dl_overflow(struct dl_bw *dl_b, unsigned long cap,
+				 u64 old_bw, u64 new_bw)
 {
 	return dl_b->bw != -1 &&
-	       dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
+	       cap_scale(dl_b->bw, cap) < dl_b->total_bw - old_bw + new_bw;
 }
 
-extern void dl_change_utilization(struct task_struct *p, u64 new_bw);
+/*
+ * Verify the fitness of task @p to run on @cpu taking into account the
+ * CPU original capacity and the runtime/deadline ratio of the task.
+ *
+ * The function will return true if the CPU original capacity of the
+ * @cpu scaled by SCHED_CAPACITY_SCALE >= runtime/deadline ratio of the
+ * task and false otherwise.
+ */
+static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu)
+{
+	unsigned long cap = arch_scale_cpu_capacity(cpu);
+
+	return cap_scale(p->dl.dl_deadline, cap) >= p->dl.dl_runtime;
+}
+
 extern void init_dl_bw(struct dl_bw *dl_b);
 extern int  sched_dl_global_validate(void);
 extern void sched_dl_do_global(void);
@@ -340,7 +371,6 @@
 
 	u8			idle;
 	u8			period_active;
-	u8			distribute_running;
 	u8			slack_started;
 	struct hrtimer		period_timer;
 	struct hrtimer		slack_timer;
@@ -491,7 +521,6 @@
 /* CFS-related fields in a runqueue */
 struct cfs_rq {
 	struct load_weight	load;
-	unsigned long		runnable_weight;
 	unsigned int		nr_running;
 	unsigned int		h_nr_running;      /* SCHED_{NORMAL,BATCH,IDLE} */
 	unsigned int		idle_h_nr_running; /* SCHED_IDLE */
@@ -530,7 +559,7 @@
 		int		nr;
 		unsigned long	load_avg;
 		unsigned long	util_avg;
-		unsigned long	runnable_sum;
+		unsigned long	runnable_avg;
 	} removed;
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -690,8 +719,30 @@
 #ifdef CONFIG_FAIR_GROUP_SCHED
 /* An entity is a task if it doesn't "own" a runqueue */
 #define entity_is_task(se)	(!se->my_q)
+
+static inline void se_update_runnable(struct sched_entity *se)
+{
+	if (!entity_is_task(se))
+		se->runnable_weight = se->my_q->h_nr_running;
+}
+
+static inline long se_runnable(struct sched_entity *se)
+{
+	if (entity_is_task(se))
+		return !!se->on_rq;
+	else
+		return se->runnable_weight;
+}
+
 #else
 #define entity_is_task(se)	1
+
+static inline void se_update_runnable(struct sched_entity *se) {}
+
+static inline long se_runnable(struct sched_entity *se)
+{
+	return !!se->on_rq;
+}
 #endif
 
 #ifdef CONFIG_SMP
@@ -703,10 +754,6 @@
 	return scale_load_down(se->load.weight);
 }
 
-static inline long se_runnable(struct sched_entity *se)
-{
-	return scale_load_down(se->runnable_weight);
-}
 
 static inline bool sched_asym_prefer(int a, int b)
 {
@@ -864,15 +911,17 @@
 #endif
 #ifdef CONFIG_NO_HZ_COMMON
 #ifdef CONFIG_SMP
-	unsigned long		last_load_update_tick;
 	unsigned long		last_blocked_load_update_tick;
 	unsigned int		has_blocked_load;
+	call_single_data_t	nohz_csd;
 #endif /* CONFIG_SMP */
 	unsigned int		nohz_tick_stopped;
-	atomic_t nohz_flags;
+	atomic_t		nohz_flags;
 #endif /* CONFIG_NO_HZ_COMMON */
 
-	unsigned long		nr_load_updates;
+#ifdef CONFIG_SMP
+	unsigned int		ttwu_pending;
+#endif
 	u64			nr_switches;
 
 #ifdef CONFIG_UCLAMP_TASK
@@ -900,7 +949,7 @@
 	 */
 	unsigned long		nr_uninterruptible;
 
-	struct task_struct	*curr;
+	struct task_struct __rcu	*curr;
 	struct task_struct	*idle;
 	struct task_struct	*stop;
 	unsigned long		next_balance;
@@ -928,6 +977,7 @@
 
 	struct callback_head	*balance_callback;
 
+	unsigned char		nohz_idle_balance;
 	unsigned char		idle_balance;
 
 	unsigned long		misfit_task_load;
@@ -948,12 +998,15 @@
 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
 	struct sched_avg	avg_irq;
 #endif
+#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+	struct sched_avg	avg_thermal;
+#endif
 	u64			idle_stamp;
 	u64			avg_idle;
 
 	/* This is used to determine avg_idle's max value */
 	u64			max_idle_balance_cost;
-#endif
+#endif /* CONFIG_SMP */
 
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
 	u64			prev_irq_time;
@@ -971,7 +1024,6 @@
 
 #ifdef CONFIG_SCHED_HRTICK
 #ifdef CONFIG_SMP
-	int			hrtick_csd_pending;
 	call_single_data_t	hrtick_csd;
 #endif
 	struct hrtimer		hrtick_timer;
@@ -996,10 +1048,6 @@
 	unsigned int		ttwu_local;
 #endif
 
-#ifdef CONFIG_SMP
-	struct llist_head	wake_list;
-#endif
-
 #ifdef CONFIG_CPU_IDLE
 	/* Must be inspected within a rcu lock section */
 	struct cpuidle_state	*idle_state;
@@ -1112,6 +1160,24 @@
 	return rq->clock_task;
 }
 
+/**
+ * By default the decay is the default pelt decay period.
+ * The decay shift can change the decay period in
+ * multiples of 32.
+ *  Decay shift		Decay period(ms)
+ *	0			32
+ *	1			64
+ *	2			128
+ *	3			256
+ *	4			512
+ */
+extern int sched_thermal_decay_shift;
+
+static inline u64 rq_clock_thermal(struct rq *rq)
+{
+	return rq_clock_task(rq) >> sched_thermal_decay_shift;
+}
+
 static inline void rq_clock_skip_update(struct rq *rq)
 {
 	lockdep_assert_held(&rq->lock);
@@ -1141,6 +1207,16 @@
 #endif
 };
 
+/*
+ * Lockdep annotation that avoids accidental unlocks; it's like a
+ * sticky/continuous lockdep_assert_held().
+ *
+ * This avoids code that has access to 'struct rq *rq' (basically everything in
+ * the scheduler) from accidentally unlocking the rq if they do not also have a
+ * copy of the (on-stack) 'struct rq_flags rf'.
+ *
+ * Also see Documentation/locking/lockdep-design.rst.
+ */
 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
 {
 	rf->cookie = lockdep_pin_lock(&rq->lock);
@@ -1325,8 +1401,6 @@
 	rq->balance_callback = head;
 }
 
-extern void sched_ttwu_pending(void);
-
 #define rcu_dereference_check_sched_domain(p) \
 	rcu_dereference_check((p), \
 			      lockdep_is_held(&sched_domains_mutex))
@@ -1342,8 +1416,6 @@
 	for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
 			__sd; __sd = __sd->parent)
 
-#define for_each_lower_domain(sd) for (; sd; sd = sd->child)
-
 /**
  * highest_flag_domain - Return highest sched_domain containing flag.
  * @cpu:	The CPU whose highest level of sched domain is to
@@ -1403,7 +1475,7 @@
 	int			id;
 #endif
 
-	unsigned long		cpumask[0];		/* Balance mask */
+	unsigned long		cpumask[];		/* Balance mask */
 };
 
 struct sched_group {
@@ -1421,7 +1493,7 @@
 	 * by attaching extra space to the end of the structure,
 	 * depending on how many CPUs the kernel has booted up with)
 	 */
-	unsigned long		cpumask[0];
+	unsigned long		cpumask[];
 };
 
 static inline struct cpumask *sched_group_span(struct sched_group *sg)
@@ -1464,15 +1536,11 @@
 }
 #endif
 
-extern int newidle_balance(struct rq *this_rq, struct rq_flags *rf);
+extern void flush_smp_call_function_from_idle(void);
 
-#else
-
-static inline void sched_ttwu_pending(void) { }
-
-static inline int newidle_balance(struct rq *this_rq, struct rq_flags *rf) { return 0; }
-
-#endif /* CONFIG_SMP */
+#else /* !CONFIG_SMP: */
+static inline void flush_smp_call_function_from_idle(void) { }
+#endif
 
 #include "stats.h"
 #include "autogroup.h"
@@ -1655,7 +1723,8 @@
  */
 #define WF_SYNC			0x01		/* Waker goes to sleep after wakeup */
 #define WF_FORK			0x02		/* Child wakeup after fork */
-#define WF_MIGRATED		0x4		/* Internal use, task got migrated */
+#define WF_MIGRATED		0x04		/* Internal use, task got migrated */
+#define WF_ON_CPU		0x08		/* Wakee is on_cpu */
 
 /*
  * To aid in avoiding the subversion of "niceness" due to uneven distribution
@@ -1712,7 +1781,6 @@
 #define RETRY_TASK		((void *)-1UL)
 
 struct sched_class {
-	const struct sched_class *next;
 
 #ifdef CONFIG_UCLAMP_TASK
 	int uclamp_enabled;
@@ -1721,24 +1789,12 @@
 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
 	void (*yield_task)   (struct rq *rq);
-	bool (*yield_to_task)(struct rq *rq, struct task_struct *p, bool preempt);
+	bool (*yield_to_task)(struct rq *rq, struct task_struct *p);
 
 	void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags);
 
-	/*
-	 * Both @prev and @rf are optional and may be NULL, in which case the
-	 * caller must already have invoked put_prev_task(rq, prev, rf).
-	 *
-	 * Otherwise it is the responsibility of the pick_next_task() to call
-	 * put_prev_task() on the @prev task or something equivalent, IFF it
-	 * returns a next task.
-	 *
-	 * In that case (@rf != NULL) it may return RETRY_TASK when it finds a
-	 * higher prio class has runnable tasks.
-	 */
-	struct task_struct * (*pick_next_task)(struct rq *rq,
-					       struct task_struct *prev,
-					       struct rq_flags *rf);
+	struct task_struct *(*pick_next_task)(struct rq *rq);
+
 	void (*put_prev_task)(struct rq *rq, struct task_struct *p);
 	void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
 
@@ -1781,7 +1837,7 @@
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	void (*task_change_group)(struct task_struct *p, int type);
 #endif
-};
+} __aligned(STRUCT_ALIGNMENT); /* STRUCT_ALIGN(), vmlinux.lds.h */
 
 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
 {
@@ -1795,17 +1851,18 @@
 	next->sched_class->set_next_task(rq, next, false);
 }
 
-#ifdef CONFIG_SMP
-#define sched_class_highest (&stop_sched_class)
-#else
-#define sched_class_highest (&dl_sched_class)
-#endif
+/* Defined in include/asm-generic/vmlinux.lds.h */
+extern struct sched_class __begin_sched_classes[];
+extern struct sched_class __end_sched_classes[];
+
+#define sched_class_highest (__end_sched_classes - 1)
+#define sched_class_lowest  (__begin_sched_classes - 1)
 
 #define for_class_range(class, _from, _to) \
-	for (class = (_from); class != (_to); class = class->next)
+	for (class = (_from); class != (_to); class--)
 
 #define for_each_class(class) \
-	for_class_range(class, sched_class_highest, NULL)
+	for_class_range(class, sched_class_highest, sched_class_lowest)
 
 extern const struct sched_class stop_sched_class;
 extern const struct sched_class dl_sched_class;
@@ -1833,6 +1890,9 @@
 	return rq->cfs.nr_running > 0;
 }
 
+extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
+extern struct task_struct *pick_next_task_idle(struct rq *rq);
+
 #ifdef CONFIG_SMP
 
 extern void update_group_capacity(struct sched_domain *sd, int cpu);
@@ -1890,7 +1950,6 @@
 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
-extern void init_dl_rq_bw_ratio(struct dl_rq *dl_rq);
 
 #define BW_SHIFT		20
 #define BW_UNIT			(1 << BW_SHIFT)
@@ -1913,12 +1972,7 @@
  */
 static inline void sched_update_tick_dependency(struct rq *rq)
 {
-	int cpu;
-
-	if (!tick_nohz_full_enabled())
-		return;
-
-	cpu = cpu_of(rq);
+	int cpu = cpu_of(rq);
 
 	if (!tick_nohz_full_cpu(cpu))
 		return;
@@ -1938,6 +1992,9 @@
 	unsigned prev_nr = rq->nr_running;
 
 	rq->nr_running = prev_nr + count;
+	if (trace_sched_update_nr_running_tp_enabled()) {
+		call_trace_sched_update_nr_running(rq, count);
+	}
 
 #ifdef CONFIG_SMP
 	if (prev_nr < 2 && rq->nr_running >= 2) {
@@ -1952,6 +2009,10 @@
 static inline void sub_nr_running(struct rq *rq, unsigned count)
 {
 	rq->nr_running -= count;
+	if (trace_sched_update_nr_running_tp_enabled()) {
+		call_trace_sched_update_nr_running(rq, -count);
+	}
+
 	/* Check if we still need preemption */
 	sched_update_tick_dependency(rq);
 }
@@ -1991,7 +2052,24 @@
 
 #endif /* CONFIG_SCHED_HRTICK */
 
+#ifndef arch_scale_freq_tick
+static __always_inline
+void arch_scale_freq_tick(void)
+{
+}
+#endif
+
 #ifndef arch_scale_freq_capacity
+/**
+ * arch_scale_freq_capacity - get the frequency scale factor of a given CPU.
+ * @cpu: the CPU in question.
+ *
+ * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e.
+ *
+ *     f_curr
+ *     ------ * SCHED_CAPACITY_SCALE
+ *     f_max
+ */
 static __always_inline
 unsigned long arch_scale_freq_capacity(int cpu)
 {
@@ -2323,10 +2401,10 @@
 #endif /* CONFIG_CPU_FREQ */
 
 #ifdef CONFIG_UCLAMP_TASK
-unsigned int uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
+unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
 
 /**
- * uclamp_util_with - clamp @util with @rq and @p effective uclamp values.
+ * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values.
  * @rq:		The rq to clamp against. Must not be NULL.
  * @util:	The util value to clamp.
  * @p:		The task to clamp against. Can be NULL if you want to clamp
@@ -2343,23 +2421,30 @@
  * static key is disabled.
  */
 static __always_inline
-unsigned int uclamp_util_with(struct rq *rq, unsigned int util,
-			      struct task_struct *p)
+unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
+				  struct task_struct *p)
 {
-	unsigned int min_util;
-	unsigned int max_util;
+	unsigned long min_util = 0;
+	unsigned long max_util = 0;
 
 	if (!static_branch_likely(&sched_uclamp_used))
 		return util;
 
-	min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value);
-	max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);
-
 	if (p) {
-		min_util = max(min_util, uclamp_eff_value(p, UCLAMP_MIN));
-		max_util = max(max_util, uclamp_eff_value(p, UCLAMP_MAX));
+		min_util = uclamp_eff_value(p, UCLAMP_MIN);
+		max_util = uclamp_eff_value(p, UCLAMP_MAX);
+
+		/*
+		 * Ignore last runnable task's max clamp, as this task will
+		 * reset it. Similarly, no need to read the rq's min clamp.
+		 */
+		if (rq->uclamp_flags & UCLAMP_FLAG_IDLE)
+			goto out;
 	}
 
+	min_util = max_t(unsigned long, min_util, READ_ONCE(rq->uclamp[UCLAMP_MIN].value));
+	max_util = max_t(unsigned long, max_util, READ_ONCE(rq->uclamp[UCLAMP_MAX].value));
+out:
 	/*
 	 * Since CPU's {min,max}_util clamps are MAX aggregated considering
 	 * RUNNABLE tasks with _different_ clamps, we can end up with an
@@ -2371,11 +2456,6 @@
 	return clamp(util, min_util, max_util);
 }
 
-static inline unsigned int uclamp_util(struct rq *rq, unsigned int util)
-{
-	return uclamp_util_with(rq, util, NULL);
-}
-
 /*
  * When uclamp is compiled in, the aggregation at rq level is 'turned off'
  * by default in the fast path and only gets turned on once userspace performs
@@ -2389,12 +2469,9 @@
 	return static_branch_likely(&sched_uclamp_used);
 }
 #else /* CONFIG_UCLAMP_TASK */
-static inline unsigned int uclamp_util_with(struct rq *rq, unsigned int util,
-					    struct task_struct *p)
-{
-	return util;
-}
-static inline unsigned int uclamp_util(struct rq *rq, unsigned int util)
+static inline
+unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
+				  struct task_struct *p)
 {
 	return util;
 }
@@ -2551,3 +2628,19 @@
 {
 }
 #endif
+
+#ifdef CONFIG_SMP
+static inline bool is_per_cpu_kthread(struct task_struct *p)
+{
+	if (!(p->flags & PF_KTHREAD))
+		return false;
+
+	if (p->nr_cpus_allowed != 1)
+		return false;
+
+	return true;
+}
+#endif
+
+void swake_up_all_locked(struct swait_queue_head *q);
+void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
diff --git a/kernel/sched/smp.h b/kernel/sched/smp.h
new file mode 100644
index 0000000..9620e32
--- /dev/null
+++ b/kernel/sched/smp.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Scheduler internal SMP callback types and methods between the scheduler
+ * and other internal parts of the core kernel:
+ */
+
+extern void sched_ttwu_pending(void *arg);
+
+extern void send_call_function_single_ipi(int cpu);
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index ba683fe..33d0daf 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -70,7 +70,7 @@
 		return;
 
 	if (!wakeup || p->sched_psi_wake_requeue) {
-		if (p->flags & PF_MEMSTALL)
+		if (p->in_memstall)
 			set |= TSK_MEMSTALL;
 		if (p->sched_psi_wake_requeue)
 			p->sched_psi_wake_requeue = 0;
@@ -90,9 +90,17 @@
 		return;
 
 	if (!sleep) {
-		if (p->flags & PF_MEMSTALL)
+		if (p->in_memstall)
 			clear |= TSK_MEMSTALL;
 	} else {
+		/*
+		 * When a task sleeps, schedule() dequeues it before
+		 * switching to the next one. Merge the clearing of
+		 * TSK_RUNNING and TSK_ONCPU to save an unnecessary
+		 * psi_task_change() call in psi_sched_switch().
+		 */
+		clear |= TSK_ONCPU;
+
 		if (p->in_iowait)
 			set |= TSK_IOWAIT;
 	}
@@ -109,14 +117,14 @@
 	 * deregister its sleep-persistent psi states from the old
 	 * queue, and let psi_enqueue() know it has to requeue.
 	 */
-	if (unlikely(p->in_iowait || (p->flags & PF_MEMSTALL))) {
+	if (unlikely(p->in_iowait || p->in_memstall)) {
 		struct rq_flags rf;
 		struct rq *rq;
 		int clear = 0;
 
 		if (p->in_iowait)
 			clear |= TSK_IOWAIT;
-		if (p->flags & PF_MEMSTALL)
+		if (p->in_memstall)
 			clear |= TSK_MEMSTALL;
 
 		rq = __task_rq_lock(p, &rf);
@@ -126,18 +134,31 @@
 	}
 }
 
+static inline void psi_sched_switch(struct task_struct *prev,
+				    struct task_struct *next,
+				    bool sleep)
+{
+	if (static_branch_likely(&psi_disabled))
+		return;
+
+	psi_task_switch(prev, next, sleep);
+}
+
 static inline void psi_task_tick(struct rq *rq)
 {
 	if (static_branch_likely(&psi_disabled))
 		return;
 
-	if (unlikely(rq->curr->flags & PF_MEMSTALL))
+	if (unlikely(rq->curr->in_memstall))
 		psi_memstall_tick(rq->curr, cpu_of(rq));
 }
 #else /* CONFIG_PSI */
 static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
 static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
 static inline void psi_ttwu_dequeue(struct task_struct *p) {}
+static inline void psi_sched_switch(struct task_struct *prev,
+				    struct task_struct *next,
+				    bool sleep) {}
 static inline void psi_task_tick(struct rq *rq) {}
 #endif /* CONFIG_PSI */
 
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index 02dc0a8..ceb5b6b 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -34,11 +34,8 @@
 	stop->se.exec_start = rq_clock_task(rq);
 }
 
-static struct task_struct *
-pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static struct task_struct *pick_next_task_stop(struct rq *rq)
 {
-	WARN_ON_ONCE(prev || rf);
-
 	if (!sched_stop_runnable(rq))
 		return NULL;
 
@@ -105,12 +102,6 @@
 	BUG(); /* how!?, what priority? */
 }
 
-static unsigned int
-get_rr_interval_stop(struct rq *rq, struct task_struct *task)
-{
-	return 0;
-}
-
 static void update_curr_stop(struct rq *rq)
 {
 }
@@ -118,8 +109,8 @@
 /*
  * Simple, special scheduling class for the per-CPU stop tasks:
  */
-const struct sched_class stop_sched_class = {
-	.next			= &dl_sched_class,
+const struct sched_class stop_sched_class
+	__section("__stop_sched_class") = {
 
 	.enqueue_task		= enqueue_task_stop,
 	.dequeue_task		= dequeue_task_stop,
@@ -139,8 +130,6 @@
 
 	.task_tick		= task_tick_stop,
 
-	.get_rr_interval	= get_rr_interval_stop,
-
 	.prio_changed		= prio_changed_stop,
 	.switched_to		= switched_to_stop,
 	.update_curr		= update_curr_stop,
diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c
index e83a3f8..e1c655f 100644
--- a/kernel/sched/swait.c
+++ b/kernel/sched/swait.c
@@ -32,6 +32,19 @@
 }
 EXPORT_SYMBOL(swake_up_locked);
 
+/*
+ * Wake up all waiters. This is an interface which is solely exposed for
+ * completions and not for general usage.
+ *
+ * It is intentionally different from swake_up_all() to allow usage from
+ * hard interrupt context and interrupt disabled regions.
+ */
+void swake_up_all_locked(struct swait_queue_head *q)
+{
+	while (!list_empty(&q->task_list))
+		swake_up_locked(q);
+}
+
 void swake_up_one(struct swait_queue_head *q)
 {
 	unsigned long flags;
@@ -69,7 +82,7 @@
 }
 EXPORT_SYMBOL(swake_up_all);
 
-static void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
+void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
 {
 	wait->task = current;
 	if (list_empty(&wait->task_list))
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index ffaa97a..ff2c6d3 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -25,22 +25,22 @@
 	return sched_debug_enabled;
 }
 
+#define SD_FLAG(_name, mflags) [__##_name] = { .meta_flags = mflags, .name = #_name },
+const struct sd_flag_debug sd_flag_debug[] = {
+#include <linux/sched/sd_flags.h>
+};
+#undef SD_FLAG
+
 static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 				  struct cpumask *groupmask)
 {
 	struct sched_group *group = sd->groups;
+	unsigned long flags = sd->flags;
+	unsigned int idx;
 
 	cpumask_clear(groupmask);
 
 	printk(KERN_DEBUG "%*s domain-%d: ", level, "", level);
-
-	if (!(sd->flags & SD_LOAD_BALANCE)) {
-		printk("does not load-balance\n");
-		if (sd->parent)
-			printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain has parent");
-		return -1;
-	}
-
 	printk(KERN_CONT "span=%*pbl level=%s\n",
 	       cpumask_pr_args(sched_domain_span(sd)), sd->name);
 
@@ -51,6 +51,21 @@
 		printk(KERN_ERR "ERROR: domain->groups does not contain CPU%d\n", cpu);
 	}
 
+	for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
+		unsigned int flag = BIT(idx);
+		unsigned int meta_flags = sd_flag_debug[idx].meta_flags;
+
+		if ((meta_flags & SDF_SHARED_CHILD) && sd->child &&
+		    !(sd->child->flags & flag))
+			printk(KERN_ERR "ERROR: flag %s set here but not in child\n",
+			       sd_flag_debug[idx].name);
+
+		if ((meta_flags & SDF_SHARED_PARENT) && sd->parent &&
+		    !(sd->parent->flags & flag))
+			printk(KERN_ERR "ERROR: flag %s set here but not in parent\n",
+			       sd_flag_debug[idx].name);
+	}
+
 	printk(KERN_DEBUG "%*s groups:", level + 1, "");
 	do {
 		if (!group) {
@@ -145,23 +160,22 @@
 }
 #endif /* CONFIG_SCHED_DEBUG */
 
+/* Generate a mask of SD flags with the SDF_NEEDS_GROUPS metaflag */
+#define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_NEEDS_GROUPS)) |
+static const unsigned int SD_DEGENERATE_GROUPS_MASK =
+#include <linux/sched/sd_flags.h>
+0;
+#undef SD_FLAG
+
 static int sd_degenerate(struct sched_domain *sd)
 {
 	if (cpumask_weight(sched_domain_span(sd)) == 1)
 		return 1;
 
 	/* Following flags need at least 2 groups */
-	if (sd->flags & (SD_LOAD_BALANCE |
-			 SD_BALANCE_NEWIDLE |
-			 SD_BALANCE_FORK |
-			 SD_BALANCE_EXEC |
-			 SD_SHARE_CPUCAPACITY |
-			 SD_ASYM_CPUCAPACITY |
-			 SD_SHARE_PKG_RESOURCES |
-			 SD_SHARE_POWERDOMAIN)) {
-		if (sd->groups != sd->groups->next)
-			return 0;
-	}
+	if ((sd->flags & SD_DEGENERATE_GROUPS_MASK) &&
+	    (sd->groups != sd->groups->next))
+		return 0;
 
 	/* Following flags don't use groups */
 	if (sd->flags & (SD_WAKE_AFFINE))
@@ -182,19 +196,9 @@
 		return 0;
 
 	/* Flags needing groups don't count if only 1 group in parent */
-	if (parent->groups == parent->groups->next) {
-		pflags &= ~(SD_LOAD_BALANCE |
-				SD_BALANCE_NEWIDLE |
-				SD_BALANCE_FORK |
-				SD_BALANCE_EXEC |
-				SD_ASYM_CPUCAPACITY |
-				SD_SHARE_CPUCAPACITY |
-				SD_SHARE_PKG_RESOURCES |
-				SD_PREFER_SIBLING |
-				SD_SHARE_POWERDOMAIN);
-		if (nr_node_ids == 1)
-			pflags &= ~SD_SERIALIZE;
-	}
+	if (parent->groups == parent->groups->next)
+		pflags &= ~SD_DEGENERATE_GROUPS_MASK;
+
 	if (~cflags & pflags)
 		return 0;
 
@@ -209,7 +213,7 @@
 
 #ifdef CONFIG_PROC_SYSCTL
 int sched_energy_aware_handler(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret, state;
 
@@ -282,10 +286,10 @@
 	printk(KERN_DEBUG "root_domain %*pbl:", cpumask_pr_args(cpu_map));
 
 	while (pd) {
-		printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_cstate=%d }",
+		printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_pstate=%d }",
 				cpumask_first(perf_domain_span(pd)),
 				cpumask_pr_args(perf_domain_span(pd)),
-				em_pd_nr_cap_states(pd->em_pd));
+				em_pd_nr_perf_states(pd->em_pd));
 		pd = pd->next;
 	}
 
@@ -317,31 +321,32 @@
  * EAS can be used on a root domain if it meets all the following conditions:
  *    1. an Energy Model (EM) is available;
  *    2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
- *    3. the EM complexity is low enough to keep scheduling overheads low;
- *    4. schedutil is driving the frequency of all CPUs of the rd;
+ *    3. no SMT is detected.
+ *    4. the EM complexity is low enough to keep scheduling overheads low;
+ *    5. schedutil is driving the frequency of all CPUs of the rd;
  *
  * The complexity of the Energy Model is defined as:
  *
- *              C = nr_pd * (nr_cpus + nr_cs)
+ *              C = nr_pd * (nr_cpus + nr_ps)
  *
  * with parameters defined as:
  *  - nr_pd:    the number of performance domains
  *  - nr_cpus:  the number of CPUs
- *  - nr_cs:    the sum of the number of capacity states of all performance
+ *  - nr_ps:    the sum of the number of performance states of all performance
  *              domains (for example, on a system with 2 performance domains,
- *              with 10 capacity states each, nr_cs = 2 * 10 = 20).
+ *              with 10 performance states each, nr_ps = 2 * 10 = 20).
  *
  * It is generally not a good idea to use such a model in the wake-up path on
  * very complex platforms because of the associated scheduling overheads. The
  * arbitrary constraint below prevents that. It makes EAS usable up to 16 CPUs
- * with per-CPU DVFS and less than 8 capacity states each, for example.
+ * with per-CPU DVFS and less than 8 performance states each, for example.
  */
 #define EM_MAX_COMPLEXITY 2048
 
 extern struct cpufreq_governor schedutil_gov;
 static bool build_perf_domains(const struct cpumask *cpu_map)
 {
-	int i, nr_pd = 0, nr_cs = 0, nr_cpus = cpumask_weight(cpu_map);
+	int i, nr_pd = 0, nr_ps = 0, nr_cpus = cpumask_weight(cpu_map);
 	struct perf_domain *pd = NULL, *tmp;
 	int cpu = cpumask_first(cpu_map);
 	struct root_domain *rd = cpu_rq(cpu)->rd;
@@ -360,6 +365,13 @@
 		goto free;
 	}
 
+	/* EAS definitely does *not* handle SMT */
+	if (sched_smt_active()) {
+		pr_warn("rd %*pbl: Disabling EAS, SMT is not supported\n",
+			cpumask_pr_args(cpu_map));
+		goto free;
+	}
+
 	for_each_cpu(i, cpu_map) {
 		/* Skip already covered CPUs. */
 		if (find_pd(pd, i))
@@ -386,15 +398,15 @@
 		pd = tmp;
 
 		/*
-		 * Count performance domains and capacity states for the
+		 * Count performance domains and performance states for the
 		 * complexity check.
 		 */
 		nr_pd++;
-		nr_cs += em_pd_nr_cap_states(pd->em_pd);
+		nr_ps += em_pd_nr_perf_states(pd->em_pd);
 	}
 
 	/* Bail out if the Energy Model complexity is too high. */
-	if (nr_pd * (nr_cs + nr_cpus) > EM_MAX_COMPLEXITY) {
+	if (nr_pd * (nr_ps + nr_cpus) > EM_MAX_COMPLEXITY) {
 		WARN(1, "rd %*pbl: Failed to start EAS, EM complexity is too high\n",
 						cpumask_pr_args(cpu_map));
 		goto free;
@@ -1201,16 +1213,13 @@
 	if (!attr || attr->relax_domain_level < 0) {
 		if (default_relax_domain_level < 0)
 			return;
-		else
-			request = default_relax_domain_level;
+		request = default_relax_domain_level;
 	} else
 		request = attr->relax_domain_level;
-	if (request < sd->level) {
+
+	if (sd->level > request) {
 		/* Turn off idle balance on this domain: */
 		sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
-	} else {
-		/* Turn on idle balance on this domain: */
-		sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
 	}
 }
 
@@ -1224,13 +1233,13 @@
 	case sa_rootdomain:
 		if (!atomic_read(&d->rd->refcount))
 			free_rootdomain(&d->rd->rcu);
-		/* Fall through */
+		fallthrough;
 	case sa_sd:
 		free_percpu(d->sd);
-		/* Fall through */
+		fallthrough;
 	case sa_sd_storage:
 		__sdt_free(cpu_map);
-		/* Fall through */
+		fallthrough;
 	case sa_none:
 		break;
 	}
@@ -1297,7 +1306,6 @@
  *   SD_SHARE_CPUCAPACITY   - describes SMT topologies
  *   SD_SHARE_PKG_RESOURCES - describes shared caches
  *   SD_NUMA                - describes NUMA topologies
- *   SD_SHARE_POWERDOMAIN   - describes shared power domain
  *
  * Odd one out, which beside describing the topology has a quirk also
  * prescribes the desired behaviour that goes along with it:
@@ -1308,8 +1316,7 @@
 	(SD_SHARE_CPUCAPACITY	|	\
 	 SD_SHARE_PKG_RESOURCES |	\
 	 SD_NUMA		|	\
-	 SD_ASYM_PACKING	|	\
-	 SD_SHARE_POWERDOMAIN)
+	 SD_ASYM_PACKING)
 
 static struct sched_domain *
 sd_init(struct sched_domain_topology_level *tl,
@@ -1341,13 +1348,12 @@
 	*sd = (struct sched_domain){
 		.min_interval		= sd_weight,
 		.max_interval		= 2*sd_weight,
-		.busy_factor		= 32,
-		.imbalance_pct		= 125,
+		.busy_factor		= 16,
+		.imbalance_pct		= 117,
 
 		.cache_nice_tries	= 0,
 
-		.flags			= 1*SD_LOAD_BALANCE
-					| 1*SD_BALANCE_NEWIDLE
+		.flags			= 1*SD_BALANCE_NEWIDLE
 					| 1*SD_BALANCE_EXEC
 					| 1*SD_BALANCE_FORK
 					| 0*SD_BALANCE_WAKE
@@ -1377,18 +1383,9 @@
 	 * Convert topological properties into behaviour.
 	 */
 
-	if (sd->flags & SD_ASYM_CPUCAPACITY) {
-		struct sched_domain *t = sd;
-
-		/*
-		 * Don't attempt to spread across CPUs of different capacities.
-		 */
-		if (sd->child)
-			sd->child->flags &= ~SD_PREFER_SIBLING;
-
-		for_each_lower_domain(t)
-			t->flags |= SD_BALANCE_WAKE;
-	}
+	/* Don't attempt to spread across CPUs of different capacities. */
+	if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child)
+		sd->child->flags &= ~SD_PREFER_SIBLING;
 
 	if (sd->flags & SD_SHARE_CPUCAPACITY) {
 		sd->imbalance_pct = 110;
@@ -1552,66 +1549,58 @@
 	}
 }
 
+
+#define NR_DISTANCE_VALUES (1 << DISTANCE_BITS)
+
 void sched_init_numa(void)
 {
-	int next_distance, curr_distance = node_distance(0, 0);
 	struct sched_domain_topology_level *tl;
-	int level = 0;
-	int i, j, k;
-
-	sched_domains_numa_distance = kzalloc(sizeof(int) * (nr_node_ids + 1), GFP_KERNEL);
-	if (!sched_domains_numa_distance)
-		return;
-
-	/* Includes NUMA identity node at level 0. */
-	sched_domains_numa_distance[level++] = curr_distance;
-	sched_domains_numa_levels = level;
+	unsigned long *distance_map;
+	int nr_levels = 0;
+	int i, j;
 
 	/*
 	 * O(nr_nodes^2) deduplicating selection sort -- in order to find the
 	 * unique distances in the node_distance() table.
-	 *
-	 * Assumes node_distance(0,j) includes all distances in
-	 * node_distance(i,j) in order to avoid cubic time.
 	 */
-	next_distance = curr_distance;
+	distance_map = bitmap_alloc(NR_DISTANCE_VALUES, GFP_KERNEL);
+	if (!distance_map)
+		return;
+
+	bitmap_zero(distance_map, NR_DISTANCE_VALUES);
 	for (i = 0; i < nr_node_ids; i++) {
 		for (j = 0; j < nr_node_ids; j++) {
-			for (k = 0; k < nr_node_ids; k++) {
-				int distance = node_distance(i, k);
+			int distance = node_distance(i, j);
 
-				if (distance > curr_distance &&
-				    (distance < next_distance ||
-				     next_distance == curr_distance))
-					next_distance = distance;
-
-				/*
-				 * While not a strong assumption it would be nice to know
-				 * about cases where if node A is connected to B, B is not
-				 * equally connected to A.
-				 */
-				if (sched_debug() && node_distance(k, i) != distance)
-					sched_numa_warn("Node-distance not symmetric");
-
-				if (sched_debug() && i && !find_numa_distance(distance))
-					sched_numa_warn("Node-0 not representative");
+			if (distance < LOCAL_DISTANCE || distance >= NR_DISTANCE_VALUES) {
+				sched_numa_warn("Invalid distance value range");
+				return;
 			}
-			if (next_distance != curr_distance) {
-				sched_domains_numa_distance[level++] = next_distance;
-				sched_domains_numa_levels = level;
-				curr_distance = next_distance;
-			} else break;
-		}
 
-		/*
-		 * In case of sched_debug() we verify the above assumption.
-		 */
-		if (!sched_debug())
-			break;
+			bitmap_set(distance_map, distance, 1);
+		}
+	}
+	/*
+	 * We can now figure out how many unique distance values there are and
+	 * allocate memory accordingly.
+	 */
+	nr_levels = bitmap_weight(distance_map, NR_DISTANCE_VALUES);
+
+	sched_domains_numa_distance = kcalloc(nr_levels, sizeof(int), GFP_KERNEL);
+	if (!sched_domains_numa_distance) {
+		bitmap_free(distance_map);
+		return;
 	}
 
+	for (i = 0, j = 0; i < nr_levels; i++, j++) {
+		j = find_next_bit(distance_map, NR_DISTANCE_VALUES, j);
+		sched_domains_numa_distance[i] = j;
+	}
+
+	bitmap_free(distance_map);
+
 	/*
-	 * 'level' contains the number of unique distances
+	 * 'nr_levels' contains the number of unique distances
 	 *
 	 * The sched_domains_numa_distance[] array includes the actual distance
 	 * numbers.
@@ -1620,15 +1609,15 @@
 	/*
 	 * Here, we should temporarily reset sched_domains_numa_levels to 0.
 	 * If it fails to allocate memory for array sched_domains_numa_masks[][],
-	 * the array will contain less then 'level' members. This could be
+	 * the array will contain less then 'nr_levels' members. This could be
 	 * dangerous when we use it to iterate array sched_domains_numa_masks[][]
 	 * in other functions.
 	 *
-	 * We reset it to 'level' at the end of this function.
+	 * We reset it to 'nr_levels' at the end of this function.
 	 */
 	sched_domains_numa_levels = 0;
 
-	sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL);
+	sched_domains_numa_masks = kzalloc(sizeof(void *) * nr_levels, GFP_KERNEL);
 	if (!sched_domains_numa_masks)
 		return;
 
@@ -1636,7 +1625,7 @@
 	 * Now for each level, construct a mask per node which contains all
 	 * CPUs of nodes that are that many hops away from us.
 	 */
-	for (i = 0; i < level; i++) {
+	for (i = 0; i < nr_levels; i++) {
 		sched_domains_numa_masks[i] =
 			kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL);
 		if (!sched_domains_numa_masks[i])
@@ -1644,12 +1633,17 @@
 
 		for (j = 0; j < nr_node_ids; j++) {
 			struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL);
+			int k;
+
 			if (!mask)
 				return;
 
 			sched_domains_numa_masks[i][j] = mask;
 
 			for_each_node(k) {
+				if (sched_debug() && (node_distance(j, k) != node_distance(k, j)))
+					sched_numa_warn("Node-distance not symmetric");
+
 				if (node_distance(j, k) > sched_domains_numa_distance[i])
 					continue;
 
@@ -1661,7 +1655,7 @@
 	/* Compute default topology size */
 	for (i = 0; sched_domain_topology[i].mask; i++);
 
-	tl = kzalloc((i + level + 1) *
+	tl = kzalloc((i + nr_levels + 1) *
 			sizeof(struct sched_domain_topology_level), GFP_KERNEL);
 	if (!tl)
 		return;
@@ -1684,7 +1678,7 @@
 	/*
 	 * .. and append 'j' levels of NUMA goodness.
 	 */
-	for (j = 1; j < level; i++, j++) {
+	for (j = 1; j < nr_levels; i++, j++) {
 		tl[i] = (struct sched_domain_topology_level){
 			.mask = sd_numa_mask,
 			.sd_flags = cpu_numa_flags,
@@ -1696,8 +1690,8 @@
 
 	sched_domain_topology = tl;
 
-	sched_domains_numa_levels = level;
-	sched_max_numa_distance = sched_domains_numa_distance[level - 1];
+	sched_domains_numa_levels = nr_levels;
+	sched_max_numa_distance = sched_domains_numa_distance[nr_levels - 1];
 
 	init_numa_topology_type();
 }
@@ -2004,11 +1998,10 @@
 	/* Set up domains for CPUs specified by the cpu_map: */
 	for_each_cpu(i, cpu_map) {
 		struct sched_domain_topology_level *tl;
+		int dflags = 0;
 
 		sd = NULL;
 		for_each_sd_topology(tl) {
-			int dflags = 0;
-
 			if (tl == tl_asym) {
 				dflags |= SD_ASYM_CPUCAPACITY;
 				has_asym = true;
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 84bd051..a55642a 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -169,7 +169,6 @@
  * __wake_up_sync_key - wake up threads blocked on a waitqueue.
  * @wq_head: the waitqueue
  * @mode: which threads
- * @nr_exclusive: how many wake-one or wake-many threads to wake up
  * @key: opaque value to be passed to wakeup targets
  *
  * The sync wakeup differs that the waker knows that it will schedule
@@ -183,29 +182,54 @@
  * accessing the task state.
  */
 void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode,
-			int nr_exclusive, void *key)
+			void *key)
 {
-	int wake_flags = 1; /* XXX WF_SYNC */
-
 	if (unlikely(!wq_head))
 		return;
 
-	if (unlikely(nr_exclusive != 1))
-		wake_flags = 0;
-
-	__wake_up_common_lock(wq_head, mode, nr_exclusive, wake_flags, key);
+	__wake_up_common_lock(wq_head, mode, 1, WF_SYNC, key);
 }
 EXPORT_SYMBOL_GPL(__wake_up_sync_key);
 
+/**
+ * __wake_up_locked_sync_key - wake up a thread blocked on a locked waitqueue.
+ * @wq_head: the waitqueue
+ * @mode: which threads
+ * @key: opaque value to be passed to wakeup targets
+ *
+ * The sync wakeup differs in that the waker knows that it will schedule
+ * away soon, so while the target thread will be woken up, it will not
+ * be migrated to another CPU - ie. the two threads are 'synchronized'
+ * with each other. This can prevent needless bouncing between CPUs.
+ *
+ * On UP it can prevent extra preemption.
+ *
+ * If this function wakes up a task, it executes a full memory barrier before
+ * accessing the task state.
+ */
+void __wake_up_locked_sync_key(struct wait_queue_head *wq_head,
+			       unsigned int mode, void *key)
+{
+        __wake_up_common(wq_head, mode, 1, WF_SYNC, key, NULL);
+}
+EXPORT_SYMBOL_GPL(__wake_up_locked_sync_key);
+
 /*
  * __wake_up_sync - see __wake_up_sync_key()
  */
-void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr_exclusive)
+void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode)
 {
-	__wake_up_sync_key(wq_head, mode, nr_exclusive, NULL);
+	__wake_up_sync_key(wq_head, mode, NULL);
 }
 EXPORT_SYMBOL_GPL(__wake_up_sync);	/* For internal use only */
 
+void __wake_up_pollfree(struct wait_queue_head *wq_head)
+{
+	__wake_up(wq_head, TASK_NORMAL, 0, poll_to_key(EPOLLHUP | POLLFREE));
+	/* POLLFREE must have cleared the queue. */
+	WARN_ON_ONCE(waitqueue_active(wq_head));
+}
+
 /*
  * Note: we use "set_current_state()" _after_ the wait-queue add,
  * because we need a memory barrier there on SMP, so that any
@@ -377,7 +401,7 @@
 	int ret = default_wake_function(wq_entry, mode, sync, key);
 
 	if (ret)
-		list_del_init(&wq_entry->entry);
+		list_del_init_careful(&wq_entry->entry);
 
 	return ret;
 }
diff --git a/kernel/sched/wait_bit.c b/kernel/sched/wait_bit.c
index 45eba18..02ce292 100644
--- a/kernel/sched/wait_bit.c
+++ b/kernel/sched/wait_bit.c
@@ -179,6 +179,7 @@
 			.bit_nr = -1,
 		},
 		.wq_entry = {
+			.flags	 = flags,
 			.private = current,
 			.func	 = var_wake_function,
 			.entry	 = LIST_HEAD_INIT(wbq_entry->wq_entry.entry),
diff --git a/kernel/scs.c b/kernel/scs.c
new file mode 100644
index 0000000..4ff4a7b
--- /dev/null
+++ b/kernel/scs.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shadow Call Stack support.
+ *
+ * Copyright (C) 2019 Google LLC
+ */
+
+#include <linux/kasan.h>
+#include <linux/mm.h>
+#include <linux/scs.h>
+#include <linux/slab.h>
+#include <linux/vmstat.h>
+
+static struct kmem_cache *scs_cache;
+
+static void __scs_account(void *s, int account)
+{
+	struct page *scs_page = virt_to_page(s);
+
+	mod_node_page_state(page_pgdat(scs_page), NR_KERNEL_SCS_KB,
+			    account * (SCS_SIZE / SZ_1K));
+}
+
+static void *scs_alloc(int node)
+{
+	void *s = kmem_cache_alloc_node(scs_cache, GFP_SCS, node);
+
+	if (!s)
+		return NULL;
+
+	*__scs_magic(s) = SCS_END_MAGIC;
+
+	/*
+	 * Poison the allocation to catch unintentional accesses to
+	 * the shadow stack when KASAN is enabled.
+	 */
+	kasan_poison_object_data(scs_cache, s);
+	__scs_account(s, 1);
+	return s;
+}
+
+static void scs_free(void *s)
+{
+	__scs_account(s, -1);
+	kasan_unpoison_object_data(scs_cache, s);
+	kmem_cache_free(scs_cache, s);
+}
+
+void __init scs_init(void)
+{
+	scs_cache = kmem_cache_create("scs_cache", SCS_SIZE, 0, 0, NULL);
+}
+
+int scs_prepare(struct task_struct *tsk, int node)
+{
+	void *s = scs_alloc(node);
+
+	if (!s)
+		return -ENOMEM;
+
+	task_scs(tsk) = task_scs_sp(tsk) = s;
+	return 0;
+}
+
+static void scs_check_usage(struct task_struct *tsk)
+{
+	static unsigned long highest;
+
+	unsigned long *p, prev, curr = highest, used = 0;
+
+	if (!IS_ENABLED(CONFIG_DEBUG_STACK_USAGE))
+		return;
+
+	for (p = task_scs(tsk); p < __scs_magic(tsk); ++p) {
+		if (!READ_ONCE_NOCHECK(*p))
+			break;
+		used += sizeof(*p);
+	}
+
+	while (used > curr) {
+		prev = cmpxchg_relaxed(&highest, curr, used);
+
+		if (prev == curr) {
+			pr_info("%s (%d): highest shadow stack usage: %lu bytes\n",
+				tsk->comm, task_pid_nr(tsk), used);
+			break;
+		}
+
+		curr = prev;
+	}
+}
+
+void scs_release(struct task_struct *tsk)
+{
+	void *s = task_scs(tsk);
+
+	if (!s)
+		return;
+
+	WARN(task_scs_end_corrupted(tsk),
+	     "corrupted shadow stack detected when freeing task\n");
+	scs_check_usage(tsk);
+	scs_free(s);
+}
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 1d62fa2..305f0ec 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -13,6 +13,7 @@
  * Mode 2 allows user-defined system call filters in the form
  *        of Berkeley Packet Filters/Linux Socket Filters.
  */
+#define pr_fmt(fmt) "seccomp: " fmt
 
 #include <linux/refcount.h>
 #include <linux/audit.h>
@@ -41,6 +42,7 @@
 #include <linux/tracehook.h>
 #include <linux/uaccess.h>
 #include <linux/anon_inodes.h>
+#include <linux/lockdep.h>
 
 /*
  * When SECCOMP_IOCTL_NOTIF_ID_VALID was first introduced, it had the
@@ -83,11 +85,44 @@
 	/* The return values, only valid when in SECCOMP_NOTIFY_REPLIED */
 	int error;
 	long val;
+	u32 flags;
 
-	/* Signals when this has entered SECCOMP_NOTIFY_REPLIED */
+	/*
+	 * Signals when this has changed states, such as the listener
+	 * dying, a new seccomp addfd message, or changing to REPLIED
+	 */
 	struct completion ready;
 
 	struct list_head list;
+
+	/* outstanding addfd requests */
+	struct list_head addfd;
+};
+
+/**
+ * struct seccomp_kaddfd - container for seccomp_addfd ioctl messages
+ *
+ * @file: A reference to the file to install in the other task
+ * @fd: The fd number to install it at. If the fd number is -1, it means the
+ *      installing process should allocate the fd as normal.
+ * @flags: The flags for the new file descriptor. At the moment, only O_CLOEXEC
+ *         is allowed.
+ * @ret: The return value of the installing process. It is set to the fd num
+ *       upon success (>= 0).
+ * @completion: Indicates that the installing process has completed fd
+ *              installation, or gone away (either due to successful
+ *              reply, or signal)
+ *
+ */
+struct seccomp_kaddfd {
+	struct file *file;
+	int fd;
+	unsigned int flags;
+
+	/* To only be set on reply */
+	int ret;
+	struct completion completion;
+	struct list_head list;
 };
 
 /**
@@ -101,27 +136,35 @@
  *           filter->notify_lock.
  * @next_id: The id of the next request.
  * @notifications: A list of struct seccomp_knotif elements.
- * @wqh: A wait queue for poll.
  */
 struct notification {
 	struct semaphore request;
 	u64 next_id;
 	struct list_head notifications;
-	wait_queue_head_t wqh;
 };
 
 /**
  * struct seccomp_filter - container for seccomp BPF programs
  *
- * @usage: reference count to manage the object lifetime.
- *         get/put helpers should be used when accessing an instance
- *         outside of a lifetime-guarded section.  In general, this
- *         is only needed for handling filters shared across tasks.
+ * @refs: Reference count to manage the object lifetime.
+ *	  A filter's reference count is incremented for each directly
+ *	  attached task, once for the dependent filter, and if
+ *	  requested for the user notifier. When @refs reaches zero,
+ *	  the filter can be freed.
+ * @users: A filter's @users count is incremented for each directly
+ *         attached task (filter installation, fork(), thread_sync),
+ *	   and once for the dependent filter (tracked in filter->prev).
+ *	   When it reaches zero it indicates that no direct or indirect
+ *	   users of that filter exist. No new tasks can get associated with
+ *	   this filter after reaching 0. The @users count is always smaller
+ *	   or equal to @refs. Hence, reaching 0 for @users does not mean
+ *	   the filter can be freed.
  * @log: true if all actions except for SECCOMP_RET_ALLOW should be logged
  * @prev: points to a previously installed, or inherited, filter
  * @prog: the BPF program to evaluate
  * @notif: the struct that holds all notification related information
  * @notify_lock: A lock for all notification-related accesses.
+ * @wqh: A wait queue for poll if a notifier is in use.
  *
  * seccomp_filter objects are organized in a tree linked via the @prev
  * pointer.  For any task, it appears to be a singly-linked list starting
@@ -131,15 +174,17 @@
  * how namespaces work.
  *
  * seccomp_filter objects should never be modified after being attached
- * to a task_struct (other than @usage).
+ * to a task_struct (other than @refs).
  */
 struct seccomp_filter {
-	refcount_t usage;
+	refcount_t refs;
+	refcount_t users;
 	bool log;
 	struct seccomp_filter *prev;
 	struct bpf_prog *prog;
 	struct notification *notif;
 	struct mutex notify_lock;
+	wait_queue_head_t wqh;
 };
 
 /* Limit any path through the tree to 256KB worth of instructions. */
@@ -151,6 +196,10 @@
  */
 static void populate_seccomp_data(struct seccomp_data *sd)
 {
+	/*
+	 * Instead of using current_pt_reg(), we're already doing the work
+	 * to safely fetch "current", so just use "task" everywhere below.
+	 */
 	struct task_struct *task = current;
 	struct pt_regs *regs = task_pt_regs(task);
 	unsigned long args[6];
@@ -275,16 +324,14 @@
 	 * All filters in the list are evaluated and the lowest BPF return
 	 * value always takes priority (ignoring the DATA).
 	 */
-	preempt_disable();
 	for (; f; f = f->prev) {
-		u32 cur_ret = BPF_PROG_RUN(f->prog, sd);
+		u32 cur_ret = bpf_prog_run_pin_on_cpu(f->prog, sd);
 
 		if (ACTION_ONLY(cur_ret) < ACTION_ONLY(ret)) {
 			ret = cur_ret;
 			*match = f;
 		}
 	}
-	preempt_enable();
 	return ret;
 }
 #endif /* CONFIG_SECCOMP_FILTER */
@@ -375,6 +422,59 @@
 	return 0;
 }
 
+static inline void seccomp_filter_free(struct seccomp_filter *filter)
+{
+	if (filter) {
+		bpf_prog_destroy(filter->prog);
+		kfree(filter);
+	}
+}
+
+static void __seccomp_filter_orphan(struct seccomp_filter *orig)
+{
+	while (orig && refcount_dec_and_test(&orig->users)) {
+		if (waitqueue_active(&orig->wqh))
+			wake_up_poll(&orig->wqh, EPOLLHUP);
+		orig = orig->prev;
+	}
+}
+
+static void __put_seccomp_filter(struct seccomp_filter *orig)
+{
+	/* Clean up single-reference branches iteratively. */
+	while (orig && refcount_dec_and_test(&orig->refs)) {
+		struct seccomp_filter *freeme = orig;
+		orig = orig->prev;
+		seccomp_filter_free(freeme);
+	}
+}
+
+static void __seccomp_filter_release(struct seccomp_filter *orig)
+{
+	/* Notify about any unused filters in the task's former filter tree. */
+	__seccomp_filter_orphan(orig);
+	/* Finally drop all references to the task's former tree. */
+	__put_seccomp_filter(orig);
+}
+
+/**
+ * seccomp_filter_release - Detach the task from its filter tree,
+ *			    drop its reference count, and notify
+ *			    about unused filters
+ *
+ * This function should only be called when the task is exiting as
+ * it detaches it from its filter tree. As such, READ_ONCE() and
+ * barriers are not needed here, as would normally be needed.
+ */
+void seccomp_filter_release(struct task_struct *tsk)
+{
+	struct seccomp_filter *orig = tsk->seccomp.filter;
+
+	/* Detach task from its filter tree. */
+	tsk->seccomp.filter = NULL;
+	__seccomp_filter_release(orig);
+}
+
 /**
  * seccomp_sync_threads: sets all threads to use current's filter
  *
@@ -399,14 +499,19 @@
 
 		/* Get a task reference for the new leaf node. */
 		get_seccomp_filter(caller);
+
 		/*
 		 * Drop the task reference to the shared ancestor since
 		 * current's path will hold a reference.  (This also
 		 * allows a put before the assignment.)
 		 */
-		put_seccomp_filter(thread);
+		__seccomp_filter_release(thread->seccomp.filter);
+
+		/* Make our new filter tree visible. */
 		smp_store_release(&thread->seccomp.filter,
 				  caller->seccomp.filter);
+		atomic_set(&thread->seccomp.filter_count,
+			   atomic_read(&caller->seccomp.filter_count));
 
 		/*
 		 * Don't let an unprivileged task work around
@@ -469,7 +574,9 @@
 		return ERR_PTR(ret);
 	}
 
-	refcount_set(&sfilter->usage, 1);
+	refcount_set(&sfilter->refs, 1);
+	refcount_set(&sfilter->users, 1);
+	init_waitqueue_head(&sfilter->wqh);
 
 	return sfilter;
 }
@@ -534,8 +641,12 @@
 		int ret;
 
 		ret = seccomp_can_sync_threads();
-		if (ret)
-			return ret;
+		if (ret) {
+			if (flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH)
+				return -ESRCH;
+			else
+				return ret;
+		}
 	}
 
 	/* Set log flag, if present. */
@@ -548,6 +659,7 @@
 	 */
 	filter->prev = current->seccomp.filter;
 	current->seccomp.filter = filter;
+	atomic_inc(&current->seccomp.filter_count);
 
 	/* Now that the new filter is in place, synchronize to all threads. */
 	if (flags & SECCOMP_FILTER_FLAG_TSYNC)
@@ -558,7 +670,7 @@
 
 static void __get_seccomp_filter(struct seccomp_filter *filter)
 {
-	refcount_inc(&filter->usage);
+	refcount_inc(&filter->refs);
 }
 
 /* get_seccomp_filter - increments the reference count of the filter on @tsk */
@@ -568,30 +680,7 @@
 	if (!orig)
 		return;
 	__get_seccomp_filter(orig);
-}
-
-static inline void seccomp_filter_free(struct seccomp_filter *filter)
-{
-	if (filter) {
-		bpf_prog_destroy(filter->prog);
-		kfree(filter);
-	}
-}
-
-static void __put_seccomp_filter(struct seccomp_filter *orig)
-{
-	/* Clean up single-reference branches iteratively. */
-	while (orig && refcount_dec_and_test(&orig->usage)) {
-		struct seccomp_filter *freeme = orig;
-		orig = orig->prev;
-		seccomp_filter_free(freeme);
-	}
-}
-
-/* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */
-void put_seccomp_filter(struct task_struct *tsk)
-{
-	__put_seccomp_filter(tsk->seccomp.filter);
+	refcount_inc(&orig->users);
 }
 
 static void seccomp_init_siginfo(kernel_siginfo_t *info, int syscall, int reason)
@@ -688,20 +777,20 @@
  */
 static const int mode1_syscalls[] = {
 	__NR_seccomp_read, __NR_seccomp_write, __NR_seccomp_exit, __NR_seccomp_sigreturn,
-	0, /* null terminated */
+	-1, /* negative terminated */
 };
 
 static void __secure_computing_strict(int this_syscall)
 {
-	const int *syscall_whitelist = mode1_syscalls;
+	const int *allowed_syscalls = mode1_syscalls;
 #ifdef CONFIG_COMPAT
 	if (in_compat_syscall())
-		syscall_whitelist = get_compat_mode1_syscalls();
+		allowed_syscalls = get_compat_mode1_syscalls();
 #endif
 	do {
-		if (*syscall_whitelist == this_syscall)
+		if (*allowed_syscalls == this_syscall)
 			return;
-	} while (*++syscall_whitelist);
+	} while (*++allowed_syscalls != -1);
 
 #ifdef SECCOMP_DEBUG
 	dump_stack();
@@ -739,13 +828,26 @@
 	return filter->notif->next_id++;
 }
 
-static void seccomp_do_user_notification(int this_syscall,
-					 struct seccomp_filter *match,
-					 const struct seccomp_data *sd)
+static void seccomp_handle_addfd(struct seccomp_kaddfd *addfd)
+{
+	/*
+	 * Remove the notification, and reset the list pointers, indicating
+	 * that it has been handled.
+	 */
+	list_del_init(&addfd->list);
+	addfd->ret = receive_fd_replace(addfd->fd, addfd->file, addfd->flags);
+	complete(&addfd->completion);
+}
+
+static int seccomp_do_user_notification(int this_syscall,
+					struct seccomp_filter *match,
+					const struct seccomp_data *sd)
 {
 	int err;
+	u32 flags = 0;
 	long ret = 0;
 	struct seccomp_knotif n = {};
+	struct seccomp_kaddfd *addfd, *tmp;
 
 	mutex_lock(&match->notify_lock);
 	err = -ENOSYS;
@@ -758,24 +860,45 @@
 	n.id = seccomp_next_notify_id(match);
 	init_completion(&n.ready);
 	list_add(&n.list, &match->notif->notifications);
+	INIT_LIST_HEAD(&n.addfd);
 
 	up(&match->notif->request);
-	wake_up_poll(&match->notif->wqh, EPOLLIN | EPOLLRDNORM);
-	mutex_unlock(&match->notify_lock);
+	wake_up_poll(&match->wqh, EPOLLIN | EPOLLRDNORM);
 
 	/*
 	 * This is where we wait for a reply from userspace.
 	 */
-	err = wait_for_completion_interruptible(&n.ready);
-	mutex_lock(&match->notify_lock);
-	if (err == 0) {
-		ret = n.val;
-		err = n.error;
+	do {
+		mutex_unlock(&match->notify_lock);
+		err = wait_for_completion_interruptible(&n.ready);
+		mutex_lock(&match->notify_lock);
+		if (err != 0)
+			goto interrupted;
+
+		addfd = list_first_entry_or_null(&n.addfd,
+						 struct seccomp_kaddfd, list);
+		/* Check if we were woken up by a addfd message */
+		if (addfd)
+			seccomp_handle_addfd(addfd);
+
+	}  while (n.state != SECCOMP_NOTIFY_REPLIED);
+
+	ret = n.val;
+	err = n.error;
+	flags = n.flags;
+
+interrupted:
+	/* If there were any pending addfd calls, clear them out */
+	list_for_each_entry_safe(addfd, tmp, &n.addfd, list) {
+		/* The process went away before we got a chance to handle it */
+		addfd->ret = -ESRCH;
+		list_del_init(&addfd->list);
+		complete(&addfd->completion);
 	}
 
 	/*
 	 * Note that it's possible the listener died in between the time when
-	 * we were notified of a respons (or a signal) and when we were able to
+	 * we were notified of a response (or a signal) and when we were able to
 	 * re-acquire the lock, so only delete from the list if the
 	 * notification actually exists.
 	 *
@@ -787,8 +910,14 @@
 		list_del(&n.list);
 out:
 	mutex_unlock(&match->notify_lock);
-	syscall_set_return_value(current, task_pt_regs(current),
+
+	/* Userspace requests to continue the syscall. */
+	if (flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE)
+		return 0;
+
+	syscall_set_return_value(current, current_pt_regs(),
 				 err, ret);
+	return -1;
 }
 
 static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
@@ -819,13 +948,13 @@
 		/* Set low-order bits as an errno, capped at MAX_ERRNO. */
 		if (data > MAX_ERRNO)
 			data = MAX_ERRNO;
-		syscall_set_return_value(current, task_pt_regs(current),
+		syscall_set_return_value(current, current_pt_regs(),
 					 -data, 0);
 		goto skip;
 
 	case SECCOMP_RET_TRAP:
 		/* Show the handler the original registers. */
-		syscall_rollback(current, task_pt_regs(current));
+		syscall_rollback(current, current_pt_regs());
 		/* Let the filter pass back 16 bits of data. */
 		seccomp_send_sigsys(this_syscall, data);
 		goto skip;
@@ -838,7 +967,7 @@
 		/* ENOSYS these calls if there is no tracer attached. */
 		if (!ptrace_event_enabled(current, PTRACE_EVENT_SECCOMP)) {
 			syscall_set_return_value(current,
-						 task_pt_regs(current),
+						 current_pt_regs(),
 						 -ENOSYS, 0);
 			goto skip;
 		}
@@ -858,7 +987,7 @@
 		if (fatal_signal_pending(current))
 			goto skip;
 		/* Check if the tracer forced the syscall to be skipped. */
-		this_syscall = syscall_get_nr(current, task_pt_regs(current));
+		this_syscall = syscall_get_nr(current, current_pt_regs());
 		if (this_syscall < 0)
 			goto skip;
 
@@ -874,8 +1003,10 @@
 		return 0;
 
 	case SECCOMP_RET_USER_NOTIF:
-		seccomp_do_user_notification(this_syscall, match, sd);
-		goto skip;
+		if (seccomp_do_user_notification(this_syscall, match, sd))
+			goto skip;
+
+		return 0;
 
 	case SECCOMP_RET_LOG:
 		seccomp_log(this_syscall, 0, action, true);
@@ -894,20 +1025,20 @@
 	default:
 		seccomp_log(this_syscall, SIGSYS, action, true);
 		/* Dump core only if this is the last remaining thread. */
-		if (action == SECCOMP_RET_KILL_PROCESS ||
+		if (action != SECCOMP_RET_KILL_THREAD ||
 		    get_nr_threads(current) == 1) {
 			kernel_siginfo_t info;
 
 			/* Show the original registers in the dump. */
-			syscall_rollback(current, task_pt_regs(current));
+			syscall_rollback(current, current_pt_regs());
 			/* Trigger a manual coredump since do_exit skips it. */
 			seccomp_init_siginfo(&info, this_syscall, data);
 			do_coredump(&info);
 		}
-		if (action == SECCOMP_RET_KILL_PROCESS)
-			do_group_exit(SIGSYS);
-		else
+		if (action == SECCOMP_RET_KILL_THREAD)
 			do_exit(SIGSYS);
+		else
+			do_group_exit(SIGSYS);
 	}
 
 	unreachable();
@@ -936,7 +1067,7 @@
 		return 0;
 
 	this_syscall = sd ? sd->nr :
-		syscall_get_nr(current, task_pt_regs(current));
+		syscall_get_nr(current, current_pt_regs());
 
 	switch (mode) {
 	case SECCOMP_MODE_STRICT:
@@ -985,13 +1116,18 @@
 }
 
 #ifdef CONFIG_SECCOMP_FILTER
-static int seccomp_notify_release(struct inode *inode, struct file *file)
+static void seccomp_notify_free(struct seccomp_filter *filter)
 {
-	struct seccomp_filter *filter = file->private_data;
+	kfree(filter->notif);
+	filter->notif = NULL;
+}
+
+static void seccomp_notify_detach(struct seccomp_filter *filter)
+{
 	struct seccomp_knotif *knotif;
 
 	if (!filter)
-		return 0;
+		return;
 
 	mutex_lock(&filter->notify_lock);
 
@@ -1007,16 +1143,44 @@
 		knotif->error = -ENOSYS;
 		knotif->val = 0;
 
+		/*
+		 * We do not need to wake up any pending addfd messages, as
+		 * the notifier will do that for us, as this just looks
+		 * like a standard reply.
+		 */
 		complete(&knotif->ready);
 	}
 
-	kfree(filter->notif);
-	filter->notif = NULL;
+	seccomp_notify_free(filter);
 	mutex_unlock(&filter->notify_lock);
+}
+
+static int seccomp_notify_release(struct inode *inode, struct file *file)
+{
+	struct seccomp_filter *filter = file->private_data;
+
+	seccomp_notify_detach(filter);
 	__put_seccomp_filter(filter);
 	return 0;
 }
 
+/* must be called with notif_lock held */
+static inline struct seccomp_knotif *
+find_notification(struct seccomp_filter *filter, u64 id)
+{
+	struct seccomp_knotif *cur;
+
+	lockdep_assert_held(&filter->notify_lock);
+
+	list_for_each_entry(cur, &filter->notif->notifications, list) {
+		if (cur->id == id)
+			return cur;
+	}
+
+	return NULL;
+}
+
+
 static long seccomp_notify_recv(struct seccomp_filter *filter,
 				void __user *buf)
 {
@@ -1060,7 +1224,7 @@
 	unotif.data = *(knotif->data);
 
 	knotif->state = SECCOMP_NOTIFY_SENT;
-	wake_up_poll(&filter->notif->wqh, EPOLLOUT | EPOLLWRNORM);
+	wake_up_poll(&filter->wqh, EPOLLOUT | EPOLLWRNORM);
 	ret = 0;
 out:
 	mutex_unlock(&filter->notify_lock);
@@ -1074,15 +1238,8 @@
 		 * may have died when we released the lock, so we need to make
 		 * sure it's still around.
 		 */
-		knotif = NULL;
 		mutex_lock(&filter->notify_lock);
-		list_for_each_entry(cur, &filter->notif->notifications, list) {
-			if (cur->id == unotif.id) {
-				knotif = cur;
-				break;
-			}
-		}
-
+		knotif = find_notification(filter, unotif.id);
 		if (knotif) {
 			knotif->state = SECCOMP_NOTIFY_INIT;
 			up(&filter->notif->request);
@@ -1097,26 +1254,24 @@
 				void __user *buf)
 {
 	struct seccomp_notif_resp resp = {};
-	struct seccomp_knotif *knotif = NULL, *cur;
+	struct seccomp_knotif *knotif;
 	long ret;
 
 	if (copy_from_user(&resp, buf, sizeof(resp)))
 		return -EFAULT;
 
-	if (resp.flags)
+	if (resp.flags & ~SECCOMP_USER_NOTIF_FLAG_CONTINUE)
+		return -EINVAL;
+
+	if ((resp.flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE) &&
+	    (resp.error || resp.val))
 		return -EINVAL;
 
 	ret = mutex_lock_interruptible(&filter->notify_lock);
 	if (ret < 0)
 		return ret;
 
-	list_for_each_entry(cur, &filter->notif->notifications, list) {
-		if (cur->id == resp.id) {
-			knotif = cur;
-			break;
-		}
-	}
-
+	knotif = find_notification(filter, resp.id);
 	if (!knotif) {
 		ret = -ENOENT;
 		goto out;
@@ -1132,6 +1287,7 @@
 	knotif->state = SECCOMP_NOTIFY_REPLIED;
 	knotif->error = resp.error;
 	knotif->val = resp.val;
+	knotif->flags = resp.flags;
 	complete(&knotif->ready);
 out:
 	mutex_unlock(&filter->notify_lock);
@@ -1141,7 +1297,7 @@
 static long seccomp_notify_id_valid(struct seccomp_filter *filter,
 				    void __user *buf)
 {
-	struct seccomp_knotif *knotif = NULL;
+	struct seccomp_knotif *knotif;
 	u64 id;
 	long ret;
 
@@ -1152,17 +1308,109 @@
 	if (ret < 0)
 		return ret;
 
-	ret = -ENOENT;
-	list_for_each_entry(knotif, &filter->notif->notifications, list) {
-		if (knotif->id == id) {
-			if (knotif->state == SECCOMP_NOTIFY_SENT)
-				ret = 0;
-			goto out;
-		}
+	knotif = find_notification(filter, id);
+	if (knotif && knotif->state == SECCOMP_NOTIFY_SENT)
+		ret = 0;
+	else
+		ret = -ENOENT;
+
+	mutex_unlock(&filter->notify_lock);
+	return ret;
+}
+
+static long seccomp_notify_addfd(struct seccomp_filter *filter,
+				 struct seccomp_notif_addfd __user *uaddfd,
+				 unsigned int size)
+{
+	struct seccomp_notif_addfd addfd;
+	struct seccomp_knotif *knotif;
+	struct seccomp_kaddfd kaddfd;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(addfd) < SECCOMP_NOTIFY_ADDFD_SIZE_VER0);
+	BUILD_BUG_ON(sizeof(addfd) != SECCOMP_NOTIFY_ADDFD_SIZE_LATEST);
+
+	if (size < SECCOMP_NOTIFY_ADDFD_SIZE_VER0 || size >= PAGE_SIZE)
+		return -EINVAL;
+
+	ret = copy_struct_from_user(&addfd, sizeof(addfd), uaddfd, size);
+	if (ret)
+		return ret;
+
+	if (addfd.newfd_flags & ~O_CLOEXEC)
+		return -EINVAL;
+
+	if (addfd.flags & ~SECCOMP_ADDFD_FLAG_SETFD)
+		return -EINVAL;
+
+	if (addfd.newfd && !(addfd.flags & SECCOMP_ADDFD_FLAG_SETFD))
+		return -EINVAL;
+
+	kaddfd.file = fget(addfd.srcfd);
+	if (!kaddfd.file)
+		return -EBADF;
+
+	kaddfd.flags = addfd.newfd_flags;
+	kaddfd.fd = (addfd.flags & SECCOMP_ADDFD_FLAG_SETFD) ?
+		    addfd.newfd : -1;
+	init_completion(&kaddfd.completion);
+
+	ret = mutex_lock_interruptible(&filter->notify_lock);
+	if (ret < 0)
+		goto out;
+
+	knotif = find_notification(filter, addfd.id);
+	if (!knotif) {
+		ret = -ENOENT;
+		goto out_unlock;
 	}
 
-out:
+	/*
+	 * We do not want to allow for FD injection to occur before the
+	 * notification has been picked up by a userspace handler, or after
+	 * the notification has been replied to.
+	 */
+	if (knotif->state != SECCOMP_NOTIFY_SENT) {
+		ret = -EINPROGRESS;
+		goto out_unlock;
+	}
+
+	list_add(&kaddfd.list, &knotif->addfd);
+	complete(&knotif->ready);
 	mutex_unlock(&filter->notify_lock);
+
+	/* Now we wait for it to be processed or be interrupted */
+	ret = wait_for_completion_interruptible(&kaddfd.completion);
+	if (ret == 0) {
+		/*
+		 * We had a successful completion. The other side has already
+		 * removed us from the addfd queue, and
+		 * wait_for_completion_interruptible has a memory barrier upon
+		 * success that lets us read this value directly without
+		 * locking.
+		 */
+		ret = kaddfd.ret;
+		goto out;
+	}
+
+	mutex_lock(&filter->notify_lock);
+	/*
+	 * Even though we were woken up by a signal and not a successful
+	 * completion, a completion may have happened in the mean time.
+	 *
+	 * We need to check again if the addfd request has been handled,
+	 * and if not, we will remove it from the queue.
+	 */
+	if (list_empty(&kaddfd.list))
+		ret = kaddfd.ret;
+	else
+		list_del(&kaddfd.list);
+
+out_unlock:
+	mutex_unlock(&filter->notify_lock);
+out:
+	fput(kaddfd.file);
+
 	return ret;
 }
 
@@ -1172,6 +1420,7 @@
 	struct seccomp_filter *filter = file->private_data;
 	void __user *buf = (void __user *)arg;
 
+	/* Fixed-size ioctls */
 	switch (cmd) {
 	case SECCOMP_IOCTL_NOTIF_RECV:
 		return seccomp_notify_recv(filter, buf);
@@ -1180,6 +1429,13 @@
 	case SECCOMP_IOCTL_NOTIF_ID_VALID_WRONG_DIR:
 	case SECCOMP_IOCTL_NOTIF_ID_VALID:
 		return seccomp_notify_id_valid(filter, buf);
+	}
+
+	/* Extensible Argument ioctls */
+#define EA_IOCTL(cmd)	((cmd) & ~(IOC_INOUT | IOCSIZE_MASK))
+	switch (EA_IOCTL(cmd)) {
+	case EA_IOCTL(SECCOMP_IOCTL_NOTIF_ADDFD):
+		return seccomp_notify_addfd(filter, buf, _IOC_SIZE(cmd));
 	default:
 		return -EINVAL;
 	}
@@ -1192,7 +1448,7 @@
 	__poll_t ret = 0;
 	struct seccomp_knotif *cur;
 
-	poll_wait(file, &filter->notif->wqh, poll_tab);
+	poll_wait(file, &filter->wqh, poll_tab);
 
 	if (mutex_lock_interruptible(&filter->notify_lock) < 0)
 		return EPOLLERR;
@@ -1208,6 +1464,9 @@
 
 	mutex_unlock(&filter->notify_lock);
 
+	if (refcount_read(&filter->users) == 0)
+		ret |= EPOLLHUP;
+
 	return ret;
 }
 
@@ -1230,7 +1489,6 @@
 	sema_init(&filter->notif->request, 0);
 	filter->notif->next_id = get_random_u64();
 	INIT_LIST_HEAD(&filter->notif->notifications);
-	init_waitqueue_head(&filter->notif->wqh);
 
 	ret = anon_inode_getfile("seccomp notify", &seccomp_notify_ops,
 				 filter, O_RDWR);
@@ -1242,7 +1500,7 @@
 
 out_notif:
 	if (IS_ERR(ret))
-		kfree(filter->notif);
+		seccomp_notify_free(filter);
 out:
 	return ret;
 }
@@ -1302,10 +1560,12 @@
 	 * In the successful case, NEW_LISTENER returns the new listener fd.
 	 * But in the failure case, TSYNC returns the thread that died. If you
 	 * combine these two flags, there's no way to tell whether something
-	 * succeeded or failed. So, let's disallow this combination.
+	 * succeeded or failed. So, let's disallow this combination if the user
+	 * has not explicitly requested no errors from TSYNC.
 	 */
 	if ((flags & SECCOMP_FILTER_FLAG_TSYNC) &&
-	    (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER))
+	    (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) &&
+	    ((flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH) == 0))
 		return -EINVAL;
 
 	/* Prepare the new filter before holding any locks. */
@@ -1363,6 +1623,7 @@
 			listener_f->private_data = NULL;
 			fput(listener_f);
 			put_unused_fd(listener);
+			seccomp_notify_detach(prepared);
 		} else {
 			fd_install(listener, listener_f);
 			ret = listener;
@@ -1790,7 +2051,7 @@
 }
 
 static int seccomp_actions_logged_handler(struct ctl_table *ro_table, int write,
-					  void __user *buffer, size_t *lenp,
+					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
 	int ret;
@@ -1836,7 +2097,7 @@
 
 	hdr = register_sysctl_paths(seccomp_sysctl_path, seccomp_sysctl_table);
 	if (!hdr)
-		pr_warn("seccomp: sysctl registration failed\n");
+		pr_warn("sysctl registration failed\n");
 	else
 		kmemleak_not_leak(hdr);
 
diff --git a/kernel/signal.c b/kernel/signal.c
index 8c97fc7..6bb2df4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -720,7 +720,7 @@
 	 * Return the first synchronous signal in the queue.
 	 */
 	list_for_each_entry(q, &pending->list, list) {
-		/* Synchronous signals have a postive si_code */
+		/* Synchronous signals have a positive si_code */
 		if ((q->info.si_code > SI_USER) &&
 		    (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) {
 			sync = q;
@@ -852,7 +852,7 @@
 			 */
 			if (!sid || sid == task_session(current))
 				break;
-			/* fall through */
+			fallthrough;
 		default:
 			return -EPERM;
 		}
@@ -1389,7 +1389,7 @@
 		 * must see ->sighand == NULL.
 		 */
 		spin_lock_irqsave(&sighand->siglock, *flags);
-		if (likely(sighand == tsk->sighand))
+		if (likely(sighand == rcu_access_pointer(tsk->sighand)))
 			break;
 		spin_unlock_irqrestore(&sighand->siglock, *flags);
 	}
@@ -1558,12 +1558,8 @@
 {
 	int ret;
 
-	if (pid > 0) {
-		rcu_read_lock();
-		ret = kill_pid_info(sig, info, find_vpid(pid));
-		rcu_read_unlock();
-		return ret;
-	}
+	if (pid > 0)
+		return kill_proc_info(sig, info, pid);
 
 	/* -INT_MIN is undefined.  Exclude this case to avoid a UBSAN warning */
 	if (pid == INT_MIN)
@@ -2101,15 +2097,6 @@
 	return true;
 }
 
-/*
- * Return non-zero if there is a SIGKILL that should be waking us up.
- * Called with the siglock held.
- */
-static bool sigkill_pending(struct task_struct *tsk)
-{
-	return sigismember(&tsk->pending.signal, SIGKILL) ||
-	       sigismember(&tsk->signal->shared_pending.signal, SIGKILL);
-}
 
 /*
  * This must be called with current->sighand->siglock held.
@@ -2136,17 +2123,16 @@
 		 * calling arch_ptrace_stop, so we must release it now.
 		 * To preserve proper semantics, we must do this before
 		 * any signal bookkeeping like checking group_stop_count.
-		 * Meanwhile, a SIGKILL could come in before we retake the
-		 * siglock.  That must prevent us from sleeping in TASK_TRACED.
-		 * So after regaining the lock, we must check for SIGKILL.
 		 */
 		spin_unlock_irq(&current->sighand->siglock);
 		arch_ptrace_stop(exit_code, info);
 		spin_lock_irq(&current->sighand->siglock);
-		if (sigkill_pending(current))
-			return;
 	}
 
+	/*
+	 * schedule() will not sleep if there is a pending signal that
+	 * can awaken the task.
+	 */
 	set_special_state(TASK_TRACED);
 
 	/*
@@ -2534,9 +2520,6 @@
 	struct signal_struct *signal = current->signal;
 	int signr;
 
-	if (unlikely(current->task_works))
-		task_work_run();
-
 	if (unlikely(uprobe_deny_signal()))
 		return false;
 
@@ -2550,6 +2533,27 @@
 relock:
 	spin_lock_irq(&sighand->siglock);
 	/*
+	 * Make sure we can safely read ->jobctl() in task_work add. As Oleg
+	 * states:
+	 *
+	 * It pairs with mb (implied by cmpxchg) before READ_ONCE. So we
+	 * roughly have
+	 *
+	 *	task_work_add:				get_signal:
+	 *	STORE(task->task_works, new_work);	STORE(task->jobctl);
+	 *	mb();					mb();
+	 *	LOAD(task->jobctl);			LOAD(task->task_works);
+	 *
+	 * and we can rely on STORE-MB-LOAD [ in task_work_add].
+	 */
+	smp_store_mb(current->jobctl, current->jobctl & ~JOBCTL_TASK_WORK);
+	if (unlikely(current->task_works)) {
+		spin_unlock_irq(&sighand->siglock);
+		task_work_run();
+		goto relock;
+	}
+
+	/*
 	 * Every stopped thread goes here after wakeup. Check to see if
 	 * we should notify the parent, prepare_signal(SIGCONT) encodes
 	 * the CLD_ si_code into SIGNAL_CLD_MASK bits.
@@ -3240,94 +3244,94 @@
 }
 
 #ifdef CONFIG_COMPAT
-int copy_siginfo_to_user32(struct compat_siginfo __user *to,
-			   const struct kernel_siginfo *from)
-#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
+/**
+ * copy_siginfo_to_external32 - copy a kernel siginfo into a compat user siginfo
+ * @to: compat siginfo destination
+ * @from: kernel siginfo source
+ *
+ * Note: This function does not work properly for the SIGCHLD on x32, but
+ * fortunately it doesn't have to.  The only valid callers for this function are
+ * copy_siginfo_to_user32, which is overriden for x32 and the coredump code.
+ * The latter does not care because SIGCHLD will never cause a coredump.
+ */
+void copy_siginfo_to_external32(struct compat_siginfo *to,
+		const struct kernel_siginfo *from)
 {
-	return __copy_siginfo_to_user32(to, from, in_x32_syscall());
-}
-int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
-			     const struct kernel_siginfo *from, bool x32_ABI)
-#endif
-{
-	struct compat_siginfo new;
-	memset(&new, 0, sizeof(new));
+	memset(to, 0, sizeof(*to));
 
-	new.si_signo = from->si_signo;
-	new.si_errno = from->si_errno;
-	new.si_code  = from->si_code;
+	to->si_signo = from->si_signo;
+	to->si_errno = from->si_errno;
+	to->si_code  = from->si_code;
 	switch(siginfo_layout(from->si_signo, from->si_code)) {
 	case SIL_KILL:
-		new.si_pid = from->si_pid;
-		new.si_uid = from->si_uid;
+		to->si_pid = from->si_pid;
+		to->si_uid = from->si_uid;
 		break;
 	case SIL_TIMER:
-		new.si_tid     = from->si_tid;
-		new.si_overrun = from->si_overrun;
-		new.si_int     = from->si_int;
+		to->si_tid     = from->si_tid;
+		to->si_overrun = from->si_overrun;
+		to->si_int     = from->si_int;
 		break;
 	case SIL_POLL:
-		new.si_band = from->si_band;
-		new.si_fd   = from->si_fd;
+		to->si_band = from->si_band;
+		to->si_fd   = from->si_fd;
 		break;
 	case SIL_FAULT:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
 		break;
 	case SIL_FAULT_MCEERR:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
-		new.si_addr_lsb = from->si_addr_lsb;
+		to->si_addr_lsb = from->si_addr_lsb;
 		break;
 	case SIL_FAULT_BNDERR:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
-		new.si_lower = ptr_to_compat(from->si_lower);
-		new.si_upper = ptr_to_compat(from->si_upper);
+		to->si_lower = ptr_to_compat(from->si_lower);
+		to->si_upper = ptr_to_compat(from->si_upper);
 		break;
 	case SIL_FAULT_PKUERR:
-		new.si_addr = ptr_to_compat(from->si_addr);
+		to->si_addr = ptr_to_compat(from->si_addr);
 #ifdef __ARCH_SI_TRAPNO
-		new.si_trapno = from->si_trapno;
+		to->si_trapno = from->si_trapno;
 #endif
-		new.si_pkey = from->si_pkey;
+		to->si_pkey = from->si_pkey;
 		break;
 	case SIL_CHLD:
-		new.si_pid    = from->si_pid;
-		new.si_uid    = from->si_uid;
-		new.si_status = from->si_status;
-#ifdef CONFIG_X86_X32_ABI
-		if (x32_ABI) {
-			new._sifields._sigchld_x32._utime = from->si_utime;
-			new._sifields._sigchld_x32._stime = from->si_stime;
-		} else
-#endif
-		{
-			new.si_utime = from->si_utime;
-			new.si_stime = from->si_stime;
-		}
+		to->si_pid = from->si_pid;
+		to->si_uid = from->si_uid;
+		to->si_status = from->si_status;
+		to->si_utime = from->si_utime;
+		to->si_stime = from->si_stime;
 		break;
 	case SIL_RT:
-		new.si_pid = from->si_pid;
-		new.si_uid = from->si_uid;
-		new.si_int = from->si_int;
+		to->si_pid = from->si_pid;
+		to->si_uid = from->si_uid;
+		to->si_int = from->si_int;
 		break;
 	case SIL_SYS:
-		new.si_call_addr = ptr_to_compat(from->si_call_addr);
-		new.si_syscall   = from->si_syscall;
-		new.si_arch      = from->si_arch;
+		to->si_call_addr = ptr_to_compat(from->si_call_addr);
+		to->si_syscall   = from->si_syscall;
+		to->si_arch      = from->si_arch;
 		break;
 	}
+}
 
+int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+			   const struct kernel_siginfo *from)
+{
+	struct compat_siginfo new;
+
+	copy_siginfo_to_external32(&new, from);
 	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
 		return -EFAULT;
-
 	return 0;
 }
 
diff --git a/kernel/smp.c b/kernel/smp.c
index 3a39093..f73a597 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -14,19 +14,21 @@
 #include <linux/export.h>
 #include <linux/percpu.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/gfp.h>
 #include <linux/smp.h>
 #include <linux/cpu.h>
 #include <linux/sched.h>
 #include <linux/sched/idle.h>
 #include <linux/hypervisor.h>
+#include <linux/sched/clock.h>
+#include <linux/nmi.h>
+#include <linux/sched/debug.h>
 
 #include "smpboot.h"
+#include "sched/smp.h"
 
-enum {
-	CSD_FLAG_LOCK		= 0x01,
-	CSD_FLAG_SYNCHRONOUS	= 0x02,
-};
+#define CSD_TYPE(_csd)	((_csd)->flags & CSD_FLAG_TYPE_MASK)
 
 struct call_function_data {
 	call_single_data_t	__percpu *csd;
@@ -84,6 +86,7 @@
 	 * still pending.
 	 */
 	flush_smp_call_function_queue(false);
+	irq_work_run();
 	return 0;
 }
 
@@ -97,6 +100,103 @@
 	smpcfd_prepare_cpu(smp_processor_id());
 }
 
+#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
+
+static DEFINE_PER_CPU(call_single_data_t *, cur_csd);
+static DEFINE_PER_CPU(smp_call_func_t, cur_csd_func);
+static DEFINE_PER_CPU(void *, cur_csd_info);
+
+#define CSD_LOCK_TIMEOUT (5ULL * NSEC_PER_SEC)
+static atomic_t csd_bug_count = ATOMIC_INIT(0);
+
+/* Record current CSD work for current CPU, NULL to erase. */
+static void csd_lock_record(struct __call_single_data *csd)
+{
+	if (!csd) {
+		smp_mb(); /* NULL cur_csd after unlock. */
+		__this_cpu_write(cur_csd, NULL);
+		return;
+	}
+	__this_cpu_write(cur_csd_func, csd->func);
+	__this_cpu_write(cur_csd_info, csd->info);
+	smp_wmb(); /* func and info before csd. */
+	__this_cpu_write(cur_csd, csd);
+	smp_mb(); /* Update cur_csd before function call. */
+		  /* Or before unlock, as the case may be. */
+}
+
+static __always_inline int csd_lock_wait_getcpu(struct __call_single_data *csd)
+{
+	unsigned int csd_type;
+
+	csd_type = CSD_TYPE(csd);
+	if (csd_type == CSD_TYPE_ASYNC || csd_type == CSD_TYPE_SYNC)
+		return csd->dst; /* Other CSD_TYPE_ values might not have ->dst. */
+	return -1;
+}
+
+/*
+ * Complain if too much time spent waiting.  Note that only
+ * the CSD_TYPE_SYNC/ASYNC types provide the destination CPU,
+ * so waiting on other types gets much less information.
+ */
+static __always_inline bool csd_lock_wait_toolong(struct __call_single_data *csd, u64 ts0, u64 *ts1, int *bug_id)
+{
+	int cpu = -1;
+	int cpux;
+	bool firsttime;
+	u64 ts2, ts_delta;
+	call_single_data_t *cpu_cur_csd;
+	unsigned int flags = READ_ONCE(csd->flags);
+
+	if (!(flags & CSD_FLAG_LOCK)) {
+		if (!unlikely(*bug_id))
+			return true;
+		cpu = csd_lock_wait_getcpu(csd);
+		pr_alert("csd: CSD lock (#%d) got unstuck on CPU#%02d, CPU#%02d released the lock.\n",
+			 *bug_id, raw_smp_processor_id(), cpu);
+		return true;
+	}
+
+	ts2 = sched_clock();
+	ts_delta = ts2 - *ts1;
+	if (likely(ts_delta <= CSD_LOCK_TIMEOUT))
+		return false;
+
+	firsttime = !*bug_id;
+	if (firsttime)
+		*bug_id = atomic_inc_return(&csd_bug_count);
+	cpu = csd_lock_wait_getcpu(csd);
+	if (WARN_ONCE(cpu < 0 || cpu >= nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu))
+		cpux = 0;
+	else
+		cpux = cpu;
+	cpu_cur_csd = smp_load_acquire(&per_cpu(cur_csd, cpux)); /* Before func and info. */
+	pr_alert("csd: %s non-responsive CSD lock (#%d) on CPU#%d, waiting %llu ns for CPU#%02d %pS(%ps).\n",
+		 firsttime ? "Detected" : "Continued", *bug_id, raw_smp_processor_id(), ts2 - ts0,
+		 cpu, csd->func, csd->info);
+	if (cpu_cur_csd && csd != cpu_cur_csd) {
+		pr_alert("\tcsd: CSD lock (#%d) handling prior %pS(%ps) request.\n",
+			 *bug_id, READ_ONCE(per_cpu(cur_csd_func, cpux)),
+			 READ_ONCE(per_cpu(cur_csd_info, cpux)));
+	} else {
+		pr_alert("\tcsd: CSD lock (#%d) %s.\n",
+			 *bug_id, !cpu_cur_csd ? "unresponsive" : "handling this request");
+	}
+	if (cpu >= 0) {
+		if (!trigger_single_cpu_backtrace(cpu))
+			dump_cpu_task(cpu);
+		if (!cpu_cur_csd) {
+			pr_alert("csd: Re-sending CSD lock (#%d) IPI from CPU#%02d to CPU#%02d\n", *bug_id, raw_smp_processor_id(), cpu);
+			arch_send_call_function_single_ipi(cpu);
+		}
+	}
+	dump_stack();
+	*ts1 = ts2;
+
+	return false;
+}
+
 /*
  * csd_lock/csd_unlock used to serialize access to per-cpu csd resources
  *
@@ -106,8 +206,28 @@
  */
 static __always_inline void csd_lock_wait(struct __call_single_data *csd)
 {
+	int bug_id = 0;
+	u64 ts0, ts1;
+
+	ts1 = ts0 = sched_clock();
+	for (;;) {
+		if (csd_lock_wait_toolong(csd, ts0, &ts1, &bug_id))
+			break;
+		cpu_relax();
+	}
+	smp_acquire__after_ctrl_dep();
+}
+
+#else
+static void csd_lock_record(struct __call_single_data *csd)
+{
+}
+
+static __always_inline void csd_lock_wait(struct __call_single_data *csd)
+{
 	smp_cond_load_acquire(&csd->flags, !(VAL & CSD_FLAG_LOCK));
 }
+#endif
 
 static __always_inline void csd_lock(struct __call_single_data *csd)
 {
@@ -134,37 +254,8 @@
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(call_single_data_t, csd_data);
 
-/*
- * Insert a previously allocated call_single_data_t element
- * for execution on the given CPU. data must already have
- * ->func, ->info, and ->flags set.
- */
-static int generic_exec_single(int cpu, struct __call_single_data *csd,
-			       smp_call_func_t func, void *info)
+void __smp_call_single_queue(int cpu, struct llist_node *node)
 {
-	if (cpu == smp_processor_id()) {
-		unsigned long flags;
-
-		/*
-		 * We can unlock early even for the synchronous on-stack case,
-		 * since we're doing this from the same CPU..
-		 */
-		csd_unlock(csd);
-		local_irq_save(flags);
-		func(info);
-		local_irq_restore(flags);
-		return 0;
-	}
-
-
-	if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu)) {
-		csd_unlock(csd);
-		return -ENXIO;
-	}
-
-	csd->func = func;
-	csd->info = info;
-
 	/*
 	 * The list addition should be visible before sending the IPI
 	 * handler locks the list to pull the entry off it because of
@@ -176,8 +267,41 @@
 	 * locking and barrier primitives. Generic code isn't really
 	 * equipped to do the right thing...
 	 */
-	if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu)))
-		arch_send_call_function_single_ipi(cpu);
+	if (llist_add(node, &per_cpu(call_single_queue, cpu)))
+		send_call_function_single_ipi(cpu);
+}
+
+/*
+ * Insert a previously allocated call_single_data_t element
+ * for execution on the given CPU. data must already have
+ * ->func, ->info, and ->flags set.
+ */
+static int generic_exec_single(int cpu, struct __call_single_data *csd)
+{
+	if (cpu == smp_processor_id()) {
+		smp_call_func_t func = csd->func;
+		void *info = csd->info;
+		unsigned long flags;
+
+		/*
+		 * We can unlock early even for the synchronous on-stack case,
+		 * since we're doing this from the same CPU..
+		 */
+		csd_lock_record(csd);
+		csd_unlock(csd);
+		local_irq_save(flags);
+		func(info);
+		csd_lock_record(NULL);
+		local_irq_restore(flags);
+		return 0;
+	}
+
+	if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu)) {
+		csd_unlock(csd);
+		return -ENXIO;
+	}
+
+	__smp_call_single_queue(cpu, &csd->llist);
 
 	return 0;
 }
@@ -209,9 +333,9 @@
  */
 static void flush_smp_call_function_queue(bool warn_cpu_offline)
 {
-	struct llist_head *head;
-	struct llist_node *entry;
 	call_single_data_t *csd, *csd_next;
+	struct llist_node *entry, *prev;
+	struct llist_head *head;
 	static bool warned;
 
 	lockdep_assert_irqs_disabled();
@@ -230,32 +354,106 @@
 		 * We don't have to use the _safe() variant here
 		 * because we are not invoking the IPI handlers yet.
 		 */
-		llist_for_each_entry(csd, entry, llist)
-			pr_warn("IPI callback %pS sent to offline CPU\n",
-				csd->func);
-	}
+		llist_for_each_entry(csd, entry, llist) {
+			switch (CSD_TYPE(csd)) {
+			case CSD_TYPE_ASYNC:
+			case CSD_TYPE_SYNC:
+			case CSD_TYPE_IRQ_WORK:
+				pr_warn("IPI callback %pS sent to offline CPU\n",
+					csd->func);
+				break;
 
-	llist_for_each_entry_safe(csd, csd_next, entry, llist) {
-		smp_call_func_t func = csd->func;
-		void *info = csd->info;
+			case CSD_TYPE_TTWU:
+				pr_warn("IPI task-wakeup sent to offline CPU\n");
+				break;
 
-		/* Do we wait until *after* callback? */
-		if (csd->flags & CSD_FLAG_SYNCHRONOUS) {
-			func(info);
-			csd_unlock(csd);
-		} else {
-			csd_unlock(csd);
-			func(info);
+			default:
+				pr_warn("IPI callback, unknown type %d, sent to offline CPU\n",
+					CSD_TYPE(csd));
+				break;
+			}
 		}
 	}
 
 	/*
-	 * Handle irq works queued remotely by irq_work_queue_on().
-	 * Smp functions above are typically synchronous so they
-	 * better run first since some other CPUs may be busy waiting
-	 * for them.
+	 * First; run all SYNC callbacks, people are waiting for us.
 	 */
-	irq_work_run();
+	prev = NULL;
+	llist_for_each_entry_safe(csd, csd_next, entry, llist) {
+		/* Do we wait until *after* callback? */
+		if (CSD_TYPE(csd) == CSD_TYPE_SYNC) {
+			smp_call_func_t func = csd->func;
+			void *info = csd->info;
+
+			if (prev) {
+				prev->next = &csd_next->llist;
+			} else {
+				entry = &csd_next->llist;
+			}
+
+			csd_lock_record(csd);
+			func(info);
+			csd_unlock(csd);
+			csd_lock_record(NULL);
+		} else {
+			prev = &csd->llist;
+		}
+	}
+
+	if (!entry)
+		return;
+
+	/*
+	 * Second; run all !SYNC callbacks.
+	 */
+	prev = NULL;
+	llist_for_each_entry_safe(csd, csd_next, entry, llist) {
+		int type = CSD_TYPE(csd);
+
+		if (type != CSD_TYPE_TTWU) {
+			if (prev) {
+				prev->next = &csd_next->llist;
+			} else {
+				entry = &csd_next->llist;
+			}
+
+			if (type == CSD_TYPE_ASYNC) {
+				smp_call_func_t func = csd->func;
+				void *info = csd->info;
+
+				csd_lock_record(csd);
+				csd_unlock(csd);
+				func(info);
+				csd_lock_record(NULL);
+			} else if (type == CSD_TYPE_IRQ_WORK) {
+				irq_work_single(csd);
+			}
+
+		} else {
+			prev = &csd->llist;
+		}
+	}
+
+	/*
+	 * Third; only CSD_TYPE_TTWU is left, issue those.
+	 */
+	if (entry)
+		sched_ttwu_pending(entry);
+}
+
+void flush_smp_call_function_from_idle(void)
+{
+	unsigned long flags;
+
+	if (llist_empty(this_cpu_ptr(&call_single_queue)))
+		return;
+
+	local_irq_save(flags);
+	flush_smp_call_function_queue(true);
+	if (local_softirq_pending())
+		do_softirq();
+
+	local_irq_restore(flags);
 }
 
 /*
@@ -271,7 +469,7 @@
 {
 	call_single_data_t *csd;
 	call_single_data_t csd_stack = {
-		.flags = CSD_FLAG_LOCK | CSD_FLAG_SYNCHRONOUS,
+		.flags = CSD_FLAG_LOCK | CSD_TYPE_SYNC,
 	};
 	int this_cpu;
 	int err;
@@ -305,7 +503,14 @@
 		csd_lock(csd);
 	}
 
-	err = generic_exec_single(cpu, csd, func, info);
+	csd->func = func;
+	csd->info = info;
+#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
+	csd->src = smp_processor_id();
+	csd->dst = cpu;
+#endif
+
+	err = generic_exec_single(cpu, csd);
 
 	if (wait)
 		csd_lock_wait(csd);
@@ -329,6 +534,11 @@
  * (ie: embedded in an object) and is responsible for synchronizing it
  * such that the IPIs performed on the @csd are strictly serialized.
  *
+ * If the function is called with one csd which has not yet been
+ * processed by previous call to smp_call_function_single_async(), the
+ * function will return immediately with -EBUSY showing that the csd
+ * object is still in progress.
+ *
  * NOTE: Be careful, there is unfortunately no current debugging facility to
  * validate the correctness of this serialization.
  */
@@ -338,14 +548,17 @@
 
 	preempt_disable();
 
-	/* We could deadlock if we have to wait here with interrupts disabled! */
-	if (WARN_ON_ONCE(csd->flags & CSD_FLAG_LOCK))
-		csd_lock_wait(csd);
+	if (csd->flags & CSD_FLAG_LOCK) {
+		err = -EBUSY;
+		goto out;
+	}
 
 	csd->flags = CSD_FLAG_LOCK;
 	smp_wmb();
 
-	err = generic_exec_single(cpu, csd, csd->func, csd->info);
+	err = generic_exec_single(cpu, csd);
+
+out:
 	preempt_enable();
 
 	return err;
@@ -395,22 +608,9 @@
 }
 EXPORT_SYMBOL_GPL(smp_call_function_any);
 
-/**
- * smp_call_function_many(): Run a function on a set of other CPUs.
- * @mask: The set of cpus to run on (only runs on online subset).
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @wait: If true, wait (atomically) until function has completed
- *        on other CPUs.
- *
- * If @wait is true, then returns once @func has returned.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler. Preemption
- * must be disabled when calling this function.
- */
-void smp_call_function_many(const struct cpumask *mask,
-			    smp_call_func_t func, void *info, bool wait)
+static void smp_call_function_many_cond(const struct cpumask *mask,
+					smp_call_func_t func, void *info,
+					bool wait, smp_cond_func_t cond_func)
 {
 	struct call_function_data *cfd;
 	int cpu, next_cpu, this_cpu = smp_processor_id();
@@ -448,7 +648,8 @@
 
 	/* Fastpath: do that cpu by itself. */
 	if (next_cpu >= nr_cpu_ids) {
-		smp_call_function_single(cpu, func, info, wait);
+		if (!cond_func || cond_func(cpu, info))
+			smp_call_function_single(cpu, func, info, wait);
 		return;
 	}
 
@@ -465,11 +666,18 @@
 	for_each_cpu(cpu, cfd->cpumask) {
 		call_single_data_t *csd = per_cpu_ptr(cfd->csd, cpu);
 
+		if (cond_func && !cond_func(cpu, info))
+			continue;
+
 		csd_lock(csd);
 		if (wait)
-			csd->flags |= CSD_FLAG_SYNCHRONOUS;
+			csd->flags |= CSD_TYPE_SYNC;
 		csd->func = func;
 		csd->info = info;
+#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
+		csd->src = smp_processor_id();
+		csd->dst = cpu;
+#endif
 		if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu)))
 			__cpumask_set_cpu(cpu, cfd->cpumask_ipi);
 	}
@@ -486,6 +694,26 @@
 		}
 	}
 }
+
+/**
+ * smp_call_function_many(): Run a function on a set of other CPUs.
+ * @mask: The set of cpus to run on (only runs on online subset).
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait (atomically) until function has completed
+ *        on other CPUs.
+ *
+ * If @wait is true, then returns once @func has returned.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler. Preemption
+ * must be disabled when calling this function.
+ */
+void smp_call_function_many(const struct cpumask *mask,
+			    smp_call_func_t func, void *info, bool wait)
+{
+	smp_call_function_many_cond(mask, func, info, wait, NULL);
+}
 EXPORT_SYMBOL(smp_call_function_many);
 
 /**
@@ -544,8 +772,7 @@
 {
 	int nr_cpus;
 
-	get_option(&str, &nr_cpus);
-	if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
+	if (get_option(&str, &nr_cpus) && nr_cpus > 0 && nr_cpus < nr_cpu_ids)
 		nr_cpu_ids = nr_cpus;
 
 	return 0;
@@ -578,20 +805,13 @@
 void __init smp_init(void)
 {
 	int num_nodes, num_cpus;
-	unsigned int cpu;
 
 	idle_threads_init();
 	cpuhp_threads_init();
 
 	pr_info("Bringing up secondary CPUs ...\n");
 
-	/* FIXME: This should be done in userspace --RR */
-	for_each_present_cpu(cpu) {
-		if (num_online_cpus() >= setup_max_cpus)
-			break;
-		if (!cpu_online(cpu))
-			cpu_up(cpu);
-	}
+	bringup_nonboot_cpus(setup_max_cpus);
 
 	num_nodes = num_online_nodes();
 	num_cpus  = num_online_cpus();
@@ -608,7 +828,7 @@
  * early_boot_irqs_disabled is set.  Use local_irq_save/restore() instead
  * of local_irq_disable/enable().
  */
-void on_each_cpu(void (*func) (void *info), void *info, int wait)
+void on_each_cpu(smp_call_func_t func, void *info, int wait)
 {
 	unsigned long flags;
 
@@ -659,7 +879,7 @@
  * for all the required CPUs to finish. This may include the local
  * processor.
  * @cond_func:	A callback function that is passed a cpu id and
- *		the the info parameter. The function is called
+ *		the info parameter. The function is called
  *		with preemption disabled. The function should
  *		return a blooean value indicating whether to IPI
  *		the specified CPU.
@@ -668,11 +888,6 @@
  * @info:	An arbitrary pointer to pass to both functions.
  * @wait:	If true, wait (atomically) until function has
  *		completed on other CPUs.
- * @gfp_flags:	GFP flags to use when allocating the cpumask
- *		used internally by the function.
- *
- * The function might sleep if the GFP flags indicates a non
- * atomic allocation is allowed.
  *
  * Preemption is disabled to protect against CPUs going offline but not online.
  * CPUs going online during the call will not be seen or sent an IPI.
@@ -680,46 +895,27 @@
  * You must not call this function with disabled interrupts or
  * from a hardware interrupt handler or from a bottom half handler.
  */
-void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
-			smp_call_func_t func, void *info, bool wait,
-			gfp_t gfp_flags, const struct cpumask *mask)
+void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
+			   void *info, bool wait, const struct cpumask *mask)
 {
-	cpumask_var_t cpus;
-	int cpu, ret;
+	int cpu = get_cpu();
 
-	might_sleep_if(gfpflags_allow_blocking(gfp_flags));
+	smp_call_function_many_cond(mask, func, info, wait, cond_func);
+	if (cpumask_test_cpu(cpu, mask) && cond_func(cpu, info)) {
+		unsigned long flags;
 
-	if (likely(zalloc_cpumask_var(&cpus, (gfp_flags|__GFP_NOWARN)))) {
-		preempt_disable();
-		for_each_cpu(cpu, mask)
-			if (cond_func(cpu, info))
-				__cpumask_set_cpu(cpu, cpus);
-		on_each_cpu_mask(cpus, func, info, wait);
-		preempt_enable();
-		free_cpumask_var(cpus);
-	} else {
-		/*
-		 * No free cpumask, bother. No matter, we'll
-		 * just have to IPI them one by one.
-		 */
-		preempt_disable();
-		for_each_cpu(cpu, mask)
-			if (cond_func(cpu, info)) {
-				ret = smp_call_function_single(cpu, func,
-								info, wait);
-				WARN_ON_ONCE(ret);
-			}
-		preempt_enable();
+		local_irq_save(flags);
+		func(info);
+		local_irq_restore(flags);
 	}
+	put_cpu();
 }
 EXPORT_SYMBOL(on_each_cpu_cond_mask);
 
-void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
-			smp_call_func_t func, void *info, bool wait,
-			gfp_t gfp_flags)
+void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
+		      void *info, bool wait)
 {
-	on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags,
-				cpu_online_mask);
+	on_each_cpu_cond_mask(cond_func, func, info, wait, cpu_online_mask);
 }
 EXPORT_SYMBOL(on_each_cpu_cond);
 
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index f25208e..e416304 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -33,7 +33,6 @@
 
 	if (!tsk)
 		return ERR_PTR(-ENOMEM);
-	init_idle(tsk, cpu);
 	return tsk;
 }
 
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 0427a86..09229ad 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -107,6 +107,12 @@
  * where hardirqs are disabled legitimately:
  */
 #ifdef CONFIG_TRACE_IRQFLAGS
+
+DEFINE_PER_CPU(int, hardirqs_enabled);
+DEFINE_PER_CPU(int, hardirq_context);
+EXPORT_PER_CPU_SYMBOL_GPL(hardirqs_enabled);
+EXPORT_PER_CPU_SYMBOL_GPL(hardirq_context);
+
 void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
 {
 	unsigned long flags;
@@ -126,7 +132,7 @@
 	 * Were softirqs turned off above:
 	 */
 	if (softirq_count() == (cnt & SOFTIRQ_MASK))
-		trace_softirqs_off(ip);
+		lockdep_softirqs_off(ip);
 	raw_local_irq_restore(flags);
 
 	if (preempt_count() == cnt) {
@@ -147,7 +153,7 @@
 		trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
 
 	if (softirq_count() == (cnt & SOFTIRQ_MASK))
-		trace_softirqs_on(_RET_IP_);
+		lockdep_softirqs_on(_RET_IP_);
 
 	__preempt_count_sub(cnt);
 }
@@ -174,7 +180,7 @@
 	 * Are softirqs going to be turned on now:
 	 */
 	if (softirq_count() == SOFTIRQ_DISABLE_OFFSET)
-		trace_softirqs_on(ip);
+		lockdep_softirqs_on(ip);
 	/*
 	 * Keep preemption disabled until we are done with
 	 * softirq processing:
@@ -224,9 +230,9 @@
 {
 	bool in_hardirq = false;
 
-	if (trace_hardirq_context(current)) {
+	if (lockdep_hardirq_context()) {
 		in_hardirq = true;
-		trace_hardirq_exit();
+		lockdep_hardirq_exit();
 	}
 
 	lockdep_softirq_enter();
@@ -239,7 +245,7 @@
 	lockdep_softirq_exit();
 
 	if (in_hardirq)
-		trace_hardirq_enter();
+		lockdep_hardirq_enter();
 }
 #else
 static inline bool lockdep_softirq_start(void) { return false; }
@@ -339,12 +345,11 @@
 	local_irq_restore(flags);
 }
 
-/*
- * Enter an interrupt context.
+/**
+ * irq_enter_rcu - Enter an interrupt context with RCU watching
  */
-void irq_enter(void)
+void irq_enter_rcu(void)
 {
-	rcu_irq_enter();
 	if (is_idle_task(current) && !in_interrupt()) {
 		/*
 		 * Prevent raise_softirq from needlessly waking up ksoftirqd
@@ -354,10 +359,18 @@
 		tick_irq_enter();
 		_local_bh_enable();
 	}
-
 	__irq_enter();
 }
 
+/**
+ * irq_enter - Enter an interrupt context including RCU update
+ */
+void irq_enter(void)
+{
+	rcu_irq_enter();
+	irq_enter_rcu();
+}
+
 static inline void invoke_softirq(void)
 {
 	if (ksoftirqd_running(local_softirq_pending()))
@@ -397,10 +410,7 @@
 #endif
 }
 
-/*
- * Exit an interrupt context. Process softirqs if needed and possible:
- */
-void irq_exit(void)
+static inline void __irq_exit_rcu(void)
 {
 #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED
 	local_irq_disable();
@@ -413,8 +423,31 @@
 		invoke_softirq();
 
 	tick_irq_exit();
+}
+
+/**
+ * irq_exit_rcu() - Exit an interrupt context without updating RCU
+ *
+ * Also processes softirqs if needed and possible.
+ */
+void irq_exit_rcu(void)
+{
+	__irq_exit_rcu();
+	 /* must be last! */
+	lockdep_hardirq_exit();
+}
+
+/**
+ * irq_exit - Exit an interrupt context, update RCU and lockdep
+ *
+ * Also processes softirqs if needed and possible.
+ */
+void irq_exit(void)
+{
+	__irq_exit_rcu();
 	rcu_irq_exit();
-	trace_hardirq_exit(); /* must be last! */
+	 /* must be last! */
+	lockdep_hardirq_exit();
 }
 
 /*
@@ -448,6 +481,7 @@
 
 void __raise_softirq_irqoff(unsigned int nr)
 {
+	lockdep_assert_irqs_disabled();
 	trace_softirq_raise(nr);
 	or_softirq_pending(1UL << nr);
 }
@@ -520,7 +554,10 @@
 				if (!test_and_clear_bit(TASKLET_STATE_SCHED,
 							&t->state))
 					BUG();
-				t->func(t->data);
+				if (t->use_callback)
+					t->callback(t);
+				else
+					t->func(t->data);
 				tasklet_unlock(t);
 				continue;
 			}
@@ -546,6 +583,18 @@
 	tasklet_action_common(a, this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ);
 }
 
+void tasklet_setup(struct tasklet_struct *t,
+		   void (*callback)(struct tasklet_struct *))
+{
+	t->next = NULL;
+	t->state = 0;
+	atomic_set(&t->count, 0);
+	t->callback = callback;
+	t->use_callback = true;
+	t->data = 0;
+}
+EXPORT_SYMBOL(tasklet_setup);
+
 void tasklet_init(struct tasklet_struct *t,
 		  void (*func)(unsigned long), unsigned long data)
 {
@@ -553,6 +602,7 @@
 	t->state = 0;
 	atomic_set(&t->count, 0);
 	t->func = func;
+	t->use_callback = false;
 	t->data = data;
 }
 EXPORT_SYMBOL(tasklet_init);
diff --git a/kernel/stackleak.c b/kernel/stackleak.c
index b193a59..dd07239 100644
--- a/kernel/stackleak.c
+++ b/kernel/stackleak.c
@@ -20,7 +20,7 @@
 static DEFINE_STATIC_KEY_FALSE(stack_erasing_bypass);
 
 int stack_erasing_sysctl(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+			void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = 0;
 	int state = !static_branch_unlikely(&stack_erasing_bypass);
@@ -48,7 +48,7 @@
 #define skip_erasing()	false
 #endif /* CONFIG_STACKLEAK_RUNTIME_DISABLE */
 
-asmlinkage void notrace stackleak_erase(void)
+asmlinkage void noinstr stackleak_erase(void)
 {
 	/* It would be nice not to have 'kstack_ptr' and 'boundary' on stack */
 	unsigned long kstack_ptr = current->lowest_stack;
@@ -102,21 +102,10 @@
 	/* Reset the 'lowest_stack' value for the next syscall */
 	current->lowest_stack = current_top_of_stack() - THREAD_SIZE/64;
 }
-NOKPROBE_SYMBOL(stackleak_erase);
 
-void __used notrace stackleak_track_stack(void)
+void __used __no_caller_saved_registers noinstr stackleak_track_stack(void)
 {
-	/*
-	 * N.B. stackleak_erase() fills the kernel stack with the poison value,
-	 * which has the register width. That code assumes that the value
-	 * of 'lowest_stack' is aligned on the register width boundary.
-	 *
-	 * That is true for x86 and x86_64 because of the kernel stack
-	 * alignment on these platforms (for details, see 'cc_stack_align' in
-	 * arch/x86/Makefile). Take care of that when you port STACKLEAK to
-	 * new platforms.
-	 */
-	unsigned long sp = (unsigned long)&sp;
+	unsigned long sp = current_stack_pointer;
 
 	/*
 	 * Having CONFIG_STACKLEAK_TRACK_MIN_SIZE larger than
@@ -125,6 +114,8 @@
 	 */
 	BUILD_BUG_ON(CONFIG_STACKLEAK_TRACK_MIN_SIZE > STACKLEAK_SEARCH_DEPTH);
 
+	/* 'lowest_stack' should be aligned on the register width boundary */
+	sp = ALIGN(sp, sizeof(unsigned long));
 	if (sp < current->lowest_stack &&
 	    sp >= (unsigned long)task_stack_page(current) +
 						sizeof(unsigned long)) {
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index c9ea7eb..9f8117c 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -78,8 +78,7 @@
 	unsigned int	len;
 };
 
-static bool stack_trace_consume_entry(void *cookie, unsigned long addr,
-				      bool reliable)
+static bool stack_trace_consume_entry(void *cookie, unsigned long addr)
 {
 	struct stacktrace_cookie *c = cookie;
 
@@ -94,12 +93,11 @@
 	return c->len < c->size;
 }
 
-static bool stack_trace_consume_entry_nosched(void *cookie, unsigned long addr,
-					      bool reliable)
+static bool stack_trace_consume_entry_nosched(void *cookie, unsigned long addr)
 {
 	if (in_sched_functions(addr))
 		return true;
-	return stack_trace_consume_entry(cookie, addr, reliable);
+	return stack_trace_consume_entry(cookie, addr);
 }
 
 /**
@@ -142,7 +140,7 @@
 		.store	= store,
 		.size	= size,
 		/* skip this function if they are tracing us */
-		.skip	= skipnr + !!(current == tsk),
+		.skip	= skipnr + (current == tsk),
 	};
 
 	if (!try_get_task_stack(tsk))
@@ -233,10 +231,9 @@
 	if (current->flags & PF_KTHREAD)
 		return 0;
 
-	fs = get_fs();
-	set_fs(USER_DS);
+	fs = force_uaccess_begin();
 	arch_stack_walk_user(consume_entry, &c, task_pt_regs(current));
-	set_fs(fs);
+	force_uaccess_end(fs);
 
 	return c.len;
 }
@@ -300,7 +297,7 @@
 		.entries	= store,
 		.max_entries	= size,
 		/* skip this function if they are tracing us */
-		.skip	= skipnr + !!(current == task),
+		.skip	= skipnr + (current == task),
 	};
 
 	save_stack_trace_tsk(task, &trace);
diff --git a/kernel/static_call.c b/kernel/static_call.c
new file mode 100644
index 0000000..dc5665b
--- /dev/null
+++ b/kernel/static_call.c
@@ -0,0 +1,543 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/static_call.h>
+#include <linux/bug.h>
+#include <linux/smp.h>
+#include <linux/sort.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/cpu.h>
+#include <linux/processor.h>
+#include <asm/sections.h>
+
+extern struct static_call_site __start_static_call_sites[],
+			       __stop_static_call_sites[];
+extern struct static_call_tramp_key __start_static_call_tramp_key[],
+				    __stop_static_call_tramp_key[];
+
+static bool static_call_initialized;
+
+/* mutex to protect key modules/sites */
+static DEFINE_MUTEX(static_call_mutex);
+
+static void static_call_lock(void)
+{
+	mutex_lock(&static_call_mutex);
+}
+
+static void static_call_unlock(void)
+{
+	mutex_unlock(&static_call_mutex);
+}
+
+static inline void *static_call_addr(struct static_call_site *site)
+{
+	return (void *)((long)site->addr + (long)&site->addr);
+}
+
+static inline unsigned long __static_call_key(const struct static_call_site *site)
+{
+	return (long)site->key + (long)&site->key;
+}
+
+static inline struct static_call_key *static_call_key(const struct static_call_site *site)
+{
+	return (void *)(__static_call_key(site) & ~STATIC_CALL_SITE_FLAGS);
+}
+
+/* These assume the key is word-aligned. */
+static inline bool static_call_is_init(struct static_call_site *site)
+{
+	return __static_call_key(site) & STATIC_CALL_SITE_INIT;
+}
+
+static inline bool static_call_is_tail(struct static_call_site *site)
+{
+	return __static_call_key(site) & STATIC_CALL_SITE_TAIL;
+}
+
+static inline void static_call_set_init(struct static_call_site *site)
+{
+	site->key = (__static_call_key(site) | STATIC_CALL_SITE_INIT) -
+		    (long)&site->key;
+}
+
+static int static_call_site_cmp(const void *_a, const void *_b)
+{
+	const struct static_call_site *a = _a;
+	const struct static_call_site *b = _b;
+	const struct static_call_key *key_a = static_call_key(a);
+	const struct static_call_key *key_b = static_call_key(b);
+
+	if (key_a < key_b)
+		return -1;
+
+	if (key_a > key_b)
+		return 1;
+
+	return 0;
+}
+
+static void static_call_site_swap(void *_a, void *_b, int size)
+{
+	long delta = (unsigned long)_a - (unsigned long)_b;
+	struct static_call_site *a = _a;
+	struct static_call_site *b = _b;
+	struct static_call_site tmp = *a;
+
+	a->addr = b->addr  - delta;
+	a->key  = b->key   - delta;
+
+	b->addr = tmp.addr + delta;
+	b->key  = tmp.key  + delta;
+}
+
+static inline void static_call_sort_entries(struct static_call_site *start,
+					    struct static_call_site *stop)
+{
+	sort(start, stop - start, sizeof(struct static_call_site),
+	     static_call_site_cmp, static_call_site_swap);
+}
+
+static inline bool static_call_key_has_mods(struct static_call_key *key)
+{
+	return !(key->type & 1);
+}
+
+static inline struct static_call_mod *static_call_key_next(struct static_call_key *key)
+{
+	if (!static_call_key_has_mods(key))
+		return NULL;
+
+	return key->mods;
+}
+
+static inline struct static_call_site *static_call_key_sites(struct static_call_key *key)
+{
+	if (static_call_key_has_mods(key))
+		return NULL;
+
+	return (struct static_call_site *)(key->type & ~1);
+}
+
+void __static_call_update(struct static_call_key *key, void *tramp, void *func)
+{
+	struct static_call_site *site, *stop;
+	struct static_call_mod *site_mod, first;
+
+	cpus_read_lock();
+	static_call_lock();
+
+	if (key->func == func)
+		goto done;
+
+	key->func = func;
+
+	arch_static_call_transform(NULL, tramp, func, false);
+
+	/*
+	 * If uninitialized, we'll not update the callsites, but they still
+	 * point to the trampoline and we just patched that.
+	 */
+	if (WARN_ON_ONCE(!static_call_initialized))
+		goto done;
+
+	first = (struct static_call_mod){
+		.next = static_call_key_next(key),
+		.mod = NULL,
+		.sites = static_call_key_sites(key),
+	};
+
+	for (site_mod = &first; site_mod; site_mod = site_mod->next) {
+		bool init = system_state < SYSTEM_RUNNING;
+		struct module *mod = site_mod->mod;
+
+		if (!site_mod->sites) {
+			/*
+			 * This can happen if the static call key is defined in
+			 * a module which doesn't use it.
+			 *
+			 * It also happens in the has_mods case, where the
+			 * 'first' entry has no sites associated with it.
+			 */
+			continue;
+		}
+
+		stop = __stop_static_call_sites;
+
+		if (mod) {
+#ifdef CONFIG_MODULES
+			stop = mod->static_call_sites +
+			       mod->num_static_call_sites;
+			init = mod->state == MODULE_STATE_COMING;
+#endif
+		}
+
+		for (site = site_mod->sites;
+		     site < stop && static_call_key(site) == key; site++) {
+			void *site_addr = static_call_addr(site);
+
+			if (!init && static_call_is_init(site))
+				continue;
+
+			if (!kernel_text_address((unsigned long)site_addr)) {
+				/*
+				 * This skips patching built-in __exit, which
+				 * is part of init_section_contains() but is
+				 * not part of kernel_text_address().
+				 *
+				 * Skipping built-in __exit is fine since it
+				 * will never be executed.
+				 */
+				WARN_ONCE(!static_call_is_init(site),
+					  "can't patch static call site at %pS",
+					  site_addr);
+				continue;
+			}
+
+			arch_static_call_transform(site_addr, NULL, func,
+						   static_call_is_tail(site));
+		}
+	}
+
+done:
+	static_call_unlock();
+	cpus_read_unlock();
+}
+EXPORT_SYMBOL_GPL(__static_call_update);
+
+static int __static_call_init(struct module *mod,
+			      struct static_call_site *start,
+			      struct static_call_site *stop)
+{
+	struct static_call_site *site;
+	struct static_call_key *key, *prev_key = NULL;
+	struct static_call_mod *site_mod;
+
+	if (start == stop)
+		return 0;
+
+	static_call_sort_entries(start, stop);
+
+	for (site = start; site < stop; site++) {
+		void *site_addr = static_call_addr(site);
+
+		if ((mod && within_module_init((unsigned long)site_addr, mod)) ||
+		    (!mod && init_section_contains(site_addr, 1)))
+			static_call_set_init(site);
+
+		key = static_call_key(site);
+		if (key != prev_key) {
+			prev_key = key;
+
+			/*
+			 * For vmlinux (!mod) avoid the allocation by storing
+			 * the sites pointer in the key itself. Also see
+			 * __static_call_update()'s @first.
+			 *
+			 * This allows architectures (eg. x86) to call
+			 * static_call_init() before memory allocation works.
+			 */
+			if (!mod) {
+				key->sites = site;
+				key->type |= 1;
+				goto do_transform;
+			}
+
+			site_mod = kzalloc(sizeof(*site_mod), GFP_KERNEL);
+			if (!site_mod)
+				return -ENOMEM;
+
+			/*
+			 * When the key has a direct sites pointer, extract
+			 * that into an explicit struct static_call_mod, so we
+			 * can have a list of modules.
+			 */
+			if (static_call_key_sites(key)) {
+				site_mod->mod = NULL;
+				site_mod->next = NULL;
+				site_mod->sites = static_call_key_sites(key);
+
+				key->mods = site_mod;
+
+				site_mod = kzalloc(sizeof(*site_mod), GFP_KERNEL);
+				if (!site_mod)
+					return -ENOMEM;
+			}
+
+			site_mod->mod = mod;
+			site_mod->sites = site;
+			site_mod->next = static_call_key_next(key);
+			key->mods = site_mod;
+		}
+
+do_transform:
+		arch_static_call_transform(site_addr, NULL, key->func,
+				static_call_is_tail(site));
+	}
+
+	return 0;
+}
+
+static int addr_conflict(struct static_call_site *site, void *start, void *end)
+{
+	unsigned long addr = (unsigned long)static_call_addr(site);
+
+	if (addr <= (unsigned long)end &&
+	    addr + CALL_INSN_SIZE > (unsigned long)start)
+		return 1;
+
+	return 0;
+}
+
+static int __static_call_text_reserved(struct static_call_site *iter_start,
+				       struct static_call_site *iter_stop,
+				       void *start, void *end, bool init)
+{
+	struct static_call_site *iter = iter_start;
+
+	while (iter < iter_stop) {
+		if (init || !static_call_is_init(iter)) {
+			if (addr_conflict(iter, start, end))
+				return 1;
+		}
+		iter++;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_MODULES
+
+static int __static_call_mod_text_reserved(void *start, void *end)
+{
+	struct module *mod;
+	int ret;
+
+	preempt_disable();
+	mod = __module_text_address((unsigned long)start);
+	WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
+	if (!try_module_get(mod))
+		mod = NULL;
+	preempt_enable();
+
+	if (!mod)
+		return 0;
+
+	ret = __static_call_text_reserved(mod->static_call_sites,
+			mod->static_call_sites + mod->num_static_call_sites,
+			start, end, mod->state == MODULE_STATE_COMING);
+
+	module_put(mod);
+
+	return ret;
+}
+
+static unsigned long tramp_key_lookup(unsigned long addr)
+{
+	struct static_call_tramp_key *start = __start_static_call_tramp_key;
+	struct static_call_tramp_key *stop = __stop_static_call_tramp_key;
+	struct static_call_tramp_key *tramp_key;
+
+	for (tramp_key = start; tramp_key != stop; tramp_key++) {
+		unsigned long tramp;
+
+		tramp = (long)tramp_key->tramp + (long)&tramp_key->tramp;
+		if (tramp == addr)
+			return (long)tramp_key->key + (long)&tramp_key->key;
+	}
+
+	return 0;
+}
+
+static int static_call_add_module(struct module *mod)
+{
+	struct static_call_site *start = mod->static_call_sites;
+	struct static_call_site *stop = start + mod->num_static_call_sites;
+	struct static_call_site *site;
+
+	for (site = start; site != stop; site++) {
+		unsigned long s_key = __static_call_key(site);
+		unsigned long addr = s_key & ~STATIC_CALL_SITE_FLAGS;
+		unsigned long key;
+
+		/*
+		 * Is the key is exported, 'addr' points to the key, which
+		 * means modules are allowed to call static_call_update() on
+		 * it.
+		 *
+		 * Otherwise, the key isn't exported, and 'addr' points to the
+		 * trampoline so we need to lookup the key.
+		 *
+		 * We go through this dance to prevent crazy modules from
+		 * abusing sensitive static calls.
+		 */
+		if (!kernel_text_address(addr))
+			continue;
+
+		key = tramp_key_lookup(addr);
+		if (!key) {
+			pr_warn("Failed to fixup __raw_static_call() usage at: %ps\n",
+				static_call_addr(site));
+			return -EINVAL;
+		}
+
+		key |= s_key & STATIC_CALL_SITE_FLAGS;
+		site->key = key - (long)&site->key;
+	}
+
+	return __static_call_init(mod, start, stop);
+}
+
+static void static_call_del_module(struct module *mod)
+{
+	struct static_call_site *start = mod->static_call_sites;
+	struct static_call_site *stop = mod->static_call_sites +
+					mod->num_static_call_sites;
+	struct static_call_key *key, *prev_key = NULL;
+	struct static_call_mod *site_mod, **prev;
+	struct static_call_site *site;
+
+	for (site = start; site < stop; site++) {
+		key = static_call_key(site);
+		if (key == prev_key)
+			continue;
+
+		prev_key = key;
+
+		for (prev = &key->mods, site_mod = key->mods;
+		     site_mod && site_mod->mod != mod;
+		     prev = &site_mod->next, site_mod = site_mod->next)
+			;
+
+		if (!site_mod)
+			continue;
+
+		*prev = site_mod->next;
+		kfree(site_mod);
+	}
+}
+
+static int static_call_module_notify(struct notifier_block *nb,
+				     unsigned long val, void *data)
+{
+	struct module *mod = data;
+	int ret = 0;
+
+	cpus_read_lock();
+	static_call_lock();
+
+	switch (val) {
+	case MODULE_STATE_COMING:
+		ret = static_call_add_module(mod);
+		if (ret) {
+			WARN(1, "Failed to allocate memory for static calls");
+			static_call_del_module(mod);
+		}
+		break;
+	case MODULE_STATE_GOING:
+		static_call_del_module(mod);
+		break;
+	}
+
+	static_call_unlock();
+	cpus_read_unlock();
+
+	return notifier_from_errno(ret);
+}
+
+static struct notifier_block static_call_module_nb = {
+	.notifier_call = static_call_module_notify,
+};
+
+#else
+
+static inline int __static_call_mod_text_reserved(void *start, void *end)
+{
+	return 0;
+}
+
+#endif /* CONFIG_MODULES */
+
+int static_call_text_reserved(void *start, void *end)
+{
+	bool init = system_state < SYSTEM_RUNNING;
+	int ret = __static_call_text_reserved(__start_static_call_sites,
+			__stop_static_call_sites, start, end, init);
+
+	if (ret)
+		return ret;
+
+	return __static_call_mod_text_reserved(start, end);
+}
+
+int __init static_call_init(void)
+{
+	int ret;
+
+	if (static_call_initialized)
+		return 0;
+
+	cpus_read_lock();
+	static_call_lock();
+	ret = __static_call_init(NULL, __start_static_call_sites,
+				 __stop_static_call_sites);
+	static_call_unlock();
+	cpus_read_unlock();
+
+	if (ret) {
+		pr_err("Failed to allocate memory for static_call!\n");
+		BUG();
+	}
+
+	static_call_initialized = true;
+
+#ifdef CONFIG_MODULES
+	register_module_notifier(&static_call_module_nb);
+#endif
+	return 0;
+}
+early_initcall(static_call_init);
+
+#ifdef CONFIG_STATIC_CALL_SELFTEST
+
+static int func_a(int x)
+{
+	return x+1;
+}
+
+static int func_b(int x)
+{
+	return x+2;
+}
+
+DEFINE_STATIC_CALL(sc_selftest, func_a);
+
+static struct static_call_data {
+      int (*func)(int);
+      int val;
+      int expect;
+} static_call_data [] __initdata = {
+      { NULL,   2, 3 },
+      { func_b, 2, 4 },
+      { func_a, 2, 3 }
+};
+
+static int __init test_static_call_init(void)
+{
+      int i;
+
+      for (i = 0; i < ARRAY_SIZE(static_call_data); i++ ) {
+	      struct static_call_data *scd = &static_call_data[i];
+
+              if (scd->func)
+                      static_call_update(sc_selftest, scd->func);
+
+              WARN_ON(static_call(sc_selftest)(scd->val) != scd->expect);
+      }
+
+      return 0;
+}
+early_initcall(test_static_call_init);
+
+#endif /* CONFIG_STATIC_CALL_SELFTEST */
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 998d50e..890b79c 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -178,7 +178,7 @@
 		set_state(msdata, msdata->state + 1);
 }
 
-void __weak stop_machine_yield(const struct cpumask *cpumask)
+notrace void __weak stop_machine_yield(const struct cpumask *cpumask)
 {
 	cpu_relax();
 }
@@ -235,6 +235,7 @@
 			 */
 			touch_nmi_watchdog();
 		}
+		rcu_momentary_dyntick_idle();
 	} while (curstate != MULTI_STOP_EXIT);
 
 	local_irq_restore(flags);
@@ -441,7 +442,7 @@
  * @cpumask were offline; otherwise, 0 if all executions of @fn
  * returned 0, any non zero return value if any returned non zero.
  */
-int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
+static int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
 {
 	int ret;
 
@@ -452,36 +453,6 @@
 	return ret;
 }
 
-/**
- * try_stop_cpus - try to stop multiple cpus
- * @cpumask: cpus to stop
- * @fn: function to execute
- * @arg: argument to @fn
- *
- * Identical to stop_cpus() except that it fails with -EAGAIN if
- * someone else is already using the facility.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * -EAGAIN if someone else is already stopping cpus, -ENOENT if
- * @fn(@arg) was not executed at all because all cpus in @cpumask were
- * offline; otherwise, 0 if all executions of @fn returned 0, any non
- * zero return value if any returned non zero.
- */
-int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
-{
-	int ret;
-
-	/* static works are used, process one request at a time */
-	if (!mutex_trylock(&stop_cpus_mutex))
-		return -EAGAIN;
-	ret = __stop_cpus(cpumask, fn, arg);
-	mutex_unlock(&stop_cpus_mutex);
-	return ret;
-}
-
 static int cpu_stop_should_run(unsigned int cpu)
 {
 	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
diff --git a/kernel/sys.c b/kernel/sys.c
index 3459a5c..24a3a28 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -47,6 +47,7 @@
 #include <linux/syscalls.h>
 #include <linux/kprobes.h>
 #include <linux/user_namespace.h>
+#include <linux/time_namespace.h>
 #include <linux/binfmts.h>
 
 #include <linux/sched.h>
@@ -372,7 +373,7 @@
 	if (rgid != (gid_t) -1) {
 		if (gid_eq(old->gid, krgid) ||
 		    gid_eq(old->egid, krgid) ||
-		    ns_capable(old->user_ns, CAP_SETGID))
+		    ns_capable_setid(old->user_ns, CAP_SETGID))
 			new->gid = krgid;
 		else
 			goto error;
@@ -381,7 +382,7 @@
 		if (gid_eq(old->gid, kegid) ||
 		    gid_eq(old->egid, kegid) ||
 		    gid_eq(old->sgid, kegid) ||
-		    ns_capable(old->user_ns, CAP_SETGID))
+		    ns_capable_setid(old->user_ns, CAP_SETGID))
 			new->egid = kegid;
 		else
 			goto error;
@@ -392,6 +393,10 @@
 		new->sgid = new->egid;
 	new->fsgid = new->egid;
 
+	retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
+	if (retval < 0)
+		goto error;
+
 	return commit_creds(new);
 
 error:
@@ -427,13 +432,17 @@
 	old = current_cred();
 
 	retval = -EPERM;
-	if (ns_capable(old->user_ns, CAP_SETGID))
+	if (ns_capable_setid(old->user_ns, CAP_SETGID))
 		new->gid = new->egid = new->sgid = new->fsgid = kgid;
 	else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
 		new->egid = new->fsgid = kgid;
 	else
 		goto error;
 
+	retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
+	if (retval < 0)
+		goto error;
+
 	return commit_creds(new);
 
 error:
@@ -735,7 +744,7 @@
 	old = current_cred();
 
 	retval = -EPERM;
-	if (!ns_capable(old->user_ns, CAP_SETGID)) {
+	if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
 		if (rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
 		    !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
 			goto error;
@@ -755,6 +764,10 @@
 		new->sgid = ksgid;
 	new->fsgid = new->egid;
 
+	retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
+	if (retval < 0)
+		goto error;
+
 	return commit_creds(new);
 
 error:
@@ -858,10 +871,11 @@
 
 	if (gid_eq(kgid, old->gid)  || gid_eq(kgid, old->egid)  ||
 	    gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
-	    ns_capable(old->user_ns, CAP_SETGID)) {
+	    ns_capable_setid(old->user_ns, CAP_SETGID)) {
 		if (!gid_eq(kgid, old->fsgid)) {
 			new->fsgid = kgid;
-			goto change_okay;
+			if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
+				goto change_okay;
 		}
 	}
 
@@ -1739,7 +1753,7 @@
 
 		if (who == RUSAGE_CHILDREN)
 			break;
-		/* fall through */
+		fallthrough;
 
 	case RUSAGE_SELF:
 		thread_group_cputime_adjusted(p, &tgutime, &tgstime);
@@ -1765,8 +1779,8 @@
 	unlock_task_sighand(p, &flags);
 
 out:
-	r->ru_utime = ns_to_timeval(utime);
-	r->ru_stime = ns_to_timeval(stime);
+	r->ru_utime = ns_to_kernel_old_timeval(utime);
+	r->ru_stime = ns_to_kernel_old_timeval(stime);
 
 	if (who != RUSAGE_CHILDREN) {
 		struct mm_struct *mm = get_task_mm(p);
@@ -1845,7 +1859,7 @@
 	if (exe_file) {
 		struct vm_area_struct *vma;
 
-		down_read(&mm->mmap_sem);
+		mmap_read_lock(mm);
 		for (vma = mm->mmap; vma; vma = vma->vm_next) {
 			if (!vma->vm_file)
 				continue;
@@ -1854,7 +1868,7 @@
 				goto exit_err;
 		}
 
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 		fput(exe_file);
 	}
 
@@ -1868,7 +1882,7 @@
 	fdput(exe);
 	return err;
 exit_err:
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 	fput(exe_file);
 	goto exit;
 }
@@ -1928,13 +1942,6 @@
 	error = -EINVAL;
 
 	/*
-	 * @brk should be after @end_data in traditional maps.
-	 */
-	if (prctl_map->start_brk <= prctl_map->end_data ||
-	    prctl_map->brk <= prctl_map->end_data)
-		goto out;
-
-	/*
 	 * Neither we should allow to override limits if they set.
 	 */
 	if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
@@ -1993,12 +2000,15 @@
 
 	if (prctl_map.exe_fd != (u32)-1) {
 		/*
-		 * Make sure the caller has the rights to
-		 * change /proc/pid/exe link: only local sys admin should
-		 * be allowed to.
+		 * Check if the current user is checkpoint/restore capable.
+		 * At the time of this writing, it checks for CAP_SYS_ADMIN
+		 * or CAP_CHECKPOINT_RESTORE.
+		 * Note that a user with access to ptrace can masquerade an
+		 * arbitrary program as any executable, even setuid ones.
+		 * This may have implications in the tomoyo subsystem.
 		 */
-		if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
-			return -EINVAL;
+		if (!checkpoint_restore_ns_capable(current_user_ns()))
+			return -EPERM;
 
 		error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
 		if (error)
@@ -2006,10 +2016,10 @@
 	}
 
 	/*
-	 * arg_lock protects concurent updates but we still need mmap_sem for
+	 * arg_lock protects concurent updates but we still need mmap_lock for
 	 * read to exclude races with sys_brk.
 	 */
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 
 	/*
 	 * We don't validate if these members are pointing to
@@ -2017,7 +2027,7 @@
 	 * VMAs already unmapped and kernel uses these members for statistics
 	 * output in procfs mostly, except
 	 *
-	 *  - @start_brk/@brk which are used in do_brk but kernel lookups
+	 *  - @start_brk/@brk which are used in do_brk_flags but kernel lookups
 	 *    for VMAs when updating these memvers so anything wrong written
 	 *    here cause kernel to swear at userspace program but won't lead
 	 *    to any problem in kernel itself
@@ -2048,7 +2058,7 @@
 	if (prctl_map.auxv_size)
 		memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
 
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 	return 0;
 }
 #endif /* CONFIG_CHECKPOINT_RESTORE */
@@ -2121,10 +2131,10 @@
 
 	/*
 	 * arg_lock protects concurent updates of arg boundaries, we need
-	 * mmap_sem for a) concurrent sys_brk, b) finding VMA for addr
+	 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
 	 * validation.
 	 */
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 	vma = find_vma(mm, addr);
 
 	spin_lock(&mm->arg_lock);
@@ -2216,17 +2226,17 @@
 	error = 0;
 out:
 	spin_unlock(&mm->arg_lock);
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 	return error;
 }
 
 #ifdef CONFIG_CHECKPOINT_RESTORE
-static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
+static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
 {
 	return put_user(me->clear_child_tid, tid_addr);
 }
 #else
-static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
+static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
 {
 	return -EINVAL;
 }
@@ -2261,6 +2271,8 @@
 	return -EINVAL;
 }
 
+#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
+
 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		unsigned long, arg4, unsigned long, arg5)
 {
@@ -2408,7 +2420,7 @@
 		error = prctl_set_mm(arg2, arg3, arg4, arg5);
 		break;
 	case PR_GET_TID_ADDRESS:
-		error = prctl_get_tid_address(me, (int __user **)arg2);
+		error = prctl_get_tid_address(me, (int __user * __user *)arg2);
 		break;
 	case PR_SET_CHILD_SUBREAPER:
 		me->signal->is_child_subreaper = !!arg2;
@@ -2439,13 +2451,13 @@
 	case PR_SET_THP_DISABLE:
 		if (arg3 || arg4 || arg5)
 			return -EINVAL;
-		if (down_write_killable(&me->mm->mmap_sem))
+		if (mmap_write_lock_killable(me->mm))
 			return -EINTR;
 		if (arg2)
 			set_bit(MMF_DISABLE_THP, &me->mm->flags);
 		else
 			clear_bit(MMF_DISABLE_THP, &me->mm->flags);
-		up_write(&me->mm->mmap_sem);
+		mmap_write_unlock(me->mm);
 		break;
 	case PR_MPX_ENABLE_MANAGEMENT:
 	case PR_MPX_DISABLE_MANAGEMENT:
@@ -2488,6 +2500,29 @@
 			return -EINVAL;
 		error = GET_TAGGED_ADDR_CTRL();
 		break;
+	case PR_SET_IO_FLUSHER:
+		if (!capable(CAP_SYS_RESOURCE))
+			return -EPERM;
+
+		if (arg3 || arg4 || arg5)
+			return -EINVAL;
+
+		if (arg2 == 1)
+			current->flags |= PR_IO_FLUSHER;
+		else if (!arg2)
+			current->flags &= ~PR_IO_FLUSHER;
+		else
+			return -EINVAL;
+		break;
+	case PR_GET_IO_FLUSHER:
+		if (!capable(CAP_SYS_RESOURCE))
+			return -EPERM;
+
+		if (arg2 || arg3 || arg4 || arg5)
+			return -EINVAL;
+
+		error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
+		break;
 	default:
 		error = -EINVAL;
 		break;
@@ -2521,6 +2556,7 @@
 	memset(info, 0, sizeof(struct sysinfo));
 
 	ktime_get_boottime_ts64(&tp);
+	timens_add_boottime(&tp);
 	info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
 
 	get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
@@ -2607,6 +2643,7 @@
 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
 {
 	struct sysinfo s;
+	struct compat_sysinfo s_32;
 
 	do_sysinfo(&s);
 
@@ -2631,23 +2668,23 @@
 		s.freehigh >>= bitcount;
 	}
 
-	if (!access_ok(info, sizeof(struct compat_sysinfo)) ||
-	    __put_user(s.uptime, &info->uptime) ||
-	    __put_user(s.loads[0], &info->loads[0]) ||
-	    __put_user(s.loads[1], &info->loads[1]) ||
-	    __put_user(s.loads[2], &info->loads[2]) ||
-	    __put_user(s.totalram, &info->totalram) ||
-	    __put_user(s.freeram, &info->freeram) ||
-	    __put_user(s.sharedram, &info->sharedram) ||
-	    __put_user(s.bufferram, &info->bufferram) ||
-	    __put_user(s.totalswap, &info->totalswap) ||
-	    __put_user(s.freeswap, &info->freeswap) ||
-	    __put_user(s.procs, &info->procs) ||
-	    __put_user(s.totalhigh, &info->totalhigh) ||
-	    __put_user(s.freehigh, &info->freehigh) ||
-	    __put_user(s.mem_unit, &info->mem_unit))
+	memset(&s_32, 0, sizeof(s_32));
+	s_32.uptime = s.uptime;
+	s_32.loads[0] = s.loads[0];
+	s_32.loads[1] = s.loads[1];
+	s_32.loads[2] = s.loads[2];
+	s_32.totalram = s.totalram;
+	s_32.freeram = s.freeram;
+	s_32.sharedram = s.sharedram;
+	s_32.bufferram = s.bufferram;
+	s_32.totalswap = s.totalswap;
+	s_32.freeswap = s.freeswap;
+	s_32.procs = s.procs;
+	s_32.totalhigh = s.totalhigh;
+	s_32.freehigh = s.freehigh;
+	s_32.mem_unit = s.mem_unit;
+	if (copy_to_user(info, &s_32, sizeof(s_32)))
 		return -EFAULT;
-
 	return 0;
 }
 #endif /* CONFIG_COMPAT */
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 34b7689..f27ac94 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -280,6 +280,7 @@
 COND_SYSCALL(munlockall);
 COND_SYSCALL(mincore);
 COND_SYSCALL(madvise);
+COND_SYSCALL(process_madvise);
 COND_SYSCALL(remap_file_pages);
 COND_SYSCALL(mbind);
 COND_SYSCALL_COMPAT(mbind);
@@ -364,13 +365,11 @@
 COND_SYSCALL_COMPAT(socketcall);
 
 /* compat syscalls for arm64, x86, ... */
-COND_SYSCALL_COMPAT(sysctl);
 COND_SYSCALL_COMPAT(fanotify_mark);
 
 /* x86 */
 COND_SYSCALL(vm86old);
 COND_SYSCALL(modify_ldt);
-COND_SYSCALL_COMPAT(quotactl32);
 COND_SYSCALL(vm86);
 COND_SYSCALL(kexec_file_load);
 
@@ -410,6 +409,29 @@
 COND_SYSCALL(bdflush);
 COND_SYSCALL(uselib);
 
+/* optional: time32 */
+COND_SYSCALL(time32);
+COND_SYSCALL(stime32);
+COND_SYSCALL(utime32);
+COND_SYSCALL(adjtimex_time32);
+COND_SYSCALL(sched_rr_get_interval_time32);
+COND_SYSCALL(nanosleep_time32);
+COND_SYSCALL(rt_sigtimedwait_time32);
+COND_SYSCALL_COMPAT(rt_sigtimedwait_time32);
+COND_SYSCALL(timer_settime32);
+COND_SYSCALL(timer_gettime32);
+COND_SYSCALL(clock_settime32);
+COND_SYSCALL(clock_gettime32);
+COND_SYSCALL(clock_getres_time32);
+COND_SYSCALL(clock_nanosleep_time32);
+COND_SYSCALL(utimes_time32);
+COND_SYSCALL(futimesat_time32);
+COND_SYSCALL(pselect6_time32);
+COND_SYSCALL_COMPAT(pselect6_time32);
+COND_SYSCALL(ppoll_time32);
+COND_SYSCALL_COMPAT(ppoll_time32);
+COND_SYSCALL(utimensat_time32);
+COND_SYSCALL(clock_adjtime32);
 
 /*
  * The syscalls below are not found in include/uapi/asm-generic/unistd.h
diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
index 2a63241..ccb7850 100644
--- a/kernel/sysctl-test.c
+++ b/kernel/sysctl-test.c
@@ -389,4 +389,6 @@
 	.test_cases = sysctl_test_cases,
 };
 
-kunit_test_suite(sysctl_test_suite);
+kunit_test_suites(&sysctl_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index eae6a07..8832440 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -68,6 +68,9 @@
 #include <linux/bpf.h>
 #include <linux/mount.h>
 #include <linux/userfaultfd_k.h>
+#include <linux/coredump.h>
+#include <linux/latencytop.h>
+#include <linux/pid.h>
 
 #include "../lib/kstrtox.h"
 
@@ -103,22 +106,6 @@
 
 #if defined(CONFIG_SYSCTL)
 
-/* External variables not in a header file. */
-extern int suid_dumpable;
-#ifdef CONFIG_COREDUMP
-extern int core_uses_pid;
-extern char core_pattern[];
-extern unsigned int core_pipe_limit;
-#endif
-extern int pid_max;
-extern int pid_max_min, pid_max_max;
-extern int percpu_pagelist_fraction;
-extern int latencytop_enabled;
-extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
-#ifndef CONFIG_MMU
-extern int sysctl_nr_trim_pages;
-#endif
-
 /* Constants used for minimum and  maximum */
 #ifdef CONFIG_LOCKUP_DETECTOR
 static int sixty = 60;
@@ -131,6 +118,7 @@
 static unsigned long one_ul = 1;
 static unsigned long long_max = LONG_MAX;
 static int one_hundred = 100;
+static int two_hundred = 200;
 static int one_thousand = 1000;
 #ifdef CONFIG_PRINTK
 static int ten_thousand = 10000;
@@ -160,24 +148,6 @@
 #ifdef CONFIG_INOTIFY_USER
 #include <linux/inotify.h>
 #endif
-#ifdef CONFIG_SPARC
-#endif
-
-#ifdef CONFIG_PARISC
-extern int pwrsw_enabled;
-#endif
-
-#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
-extern int unaligned_enabled;
-#endif
-
-#ifdef CONFIG_IA64
-extern int unaligned_dump_stack;
-#endif
-
-#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
-extern int no_unaligned_warning;
-#endif
 
 #ifdef CONFIG_PROC_SYSCTL
 
@@ -207,99 +177,13 @@
 };
 
 static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT;
-
-static int proc_do_cad_pid(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos);
-static int proc_taint(struct ctl_table *table, int write,
-			       void __user *buffer, size_t *lenp, loff_t *ppos);
-#endif
-
-#ifdef CONFIG_PRINTK
-static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos);
-#endif
-
-static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp, loff_t *ppos);
-#ifdef CONFIG_COREDUMP
-static int proc_dostring_coredump(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp, loff_t *ppos);
-#endif
-static int proc_dopipe_max_size(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp, loff_t *ppos);
-
-#ifdef CONFIG_MAGIC_SYSRQ
-/* Note: sysrq code uses its own private copy */
-static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
-
-static int sysrq_sysctl_handler(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
-{
-	int error;
-
-	error = proc_dointvec(table, write, buffer, lenp, ppos);
-	if (error)
-		return error;
-
-	if (write)
-		sysrq_toggle_support(__sysrq_enabled);
-
-	return 0;
-}
-
-#endif
-
-static struct ctl_table kern_table[];
-static struct ctl_table vm_table[];
-static struct ctl_table fs_table[];
-static struct ctl_table debug_table[];
-static struct ctl_table dev_table[];
-extern struct ctl_table random_table[];
-#ifdef CONFIG_EPOLL
-extern struct ctl_table epoll_table[];
-#endif
-
-#ifdef CONFIG_FW_LOADER_USER_HELPER
-extern struct ctl_table firmware_config_table[];
-#endif
+#endif /* CONFIG_PROC_SYSCTL */
 
 #if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \
     defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
 int sysctl_legacy_va_layout;
 #endif
 
-/* The default sysctl tables: */
-
-static struct ctl_table sysctl_base_table[] = {
-	{
-		.procname	= "kernel",
-		.mode		= 0555,
-		.child		= kern_table,
-	},
-	{
-		.procname	= "vm",
-		.mode		= 0555,
-		.child		= vm_table,
-	},
-	{
-		.procname	= "fs",
-		.mode		= 0555,
-		.child		= fs_table,
-	},
-	{
-		.procname	= "debug",
-		.mode		= 0555,
-		.child		= debug_table,
-	},
-	{
-		.procname	= "dev",
-		.mode		= 0555,
-		.child		= dev_table,
-	},
-	{ }
-};
-
 #ifdef CONFIG_SCHED_DEBUG
 static int min_sched_granularity_ns = 100000;		/* 100 usecs */
 static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
@@ -316,6 +200,1484 @@
 static int max_extfrag_threshold = 1000;
 #endif
 
+#endif /* CONFIG_SYSCTL */
+
+#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_SYSCTL)
+static int bpf_stats_handler(struct ctl_table *table, int write,
+			     void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct static_key *key = (struct static_key *)table->data;
+	static int saved_val;
+	int val, ret;
+	struct ctl_table tmp = {
+		.data   = &val,
+		.maxlen = sizeof(val),
+		.mode   = table->mode,
+		.extra1 = SYSCTL_ZERO,
+		.extra2 = SYSCTL_ONE,
+	};
+
+	if (write && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	mutex_lock(&bpf_stats_enabled_mutex);
+	val = saved_val;
+	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+	if (write && !ret && val != saved_val) {
+		if (val)
+			static_key_slow_inc(key);
+		else
+			static_key_slow_dec(key);
+		saved_val = val;
+	}
+	mutex_unlock(&bpf_stats_enabled_mutex);
+	return ret;
+}
+
+void __weak unpriv_ebpf_notify(int new_state)
+{
+}
+
+static int bpf_unpriv_handler(struct ctl_table *table, int write,
+			      void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int ret, unpriv_enable = *(int *)table->data;
+	bool locked_state = unpriv_enable == 1;
+	struct ctl_table tmp = *table;
+
+	if (write && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	tmp.data = &unpriv_enable;
+	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+	if (write && !ret) {
+		if (locked_state && unpriv_enable != 1)
+			return -EPERM;
+		*(int *)table->data = unpriv_enable;
+	}
+
+	unpriv_ebpf_notify(unpriv_enable);
+
+	return ret;
+}
+#endif /* CONFIG_BPF_SYSCALL && CONFIG_SYSCTL */
+
+/*
+ * /proc/sys support
+ */
+
+#ifdef CONFIG_PROC_SYSCTL
+
+static int _proc_do_string(char *data, int maxlen, int write,
+		char *buffer, size_t *lenp, loff_t *ppos)
+{
+	size_t len;
+	char c, *p;
+
+	if (!data || !maxlen || !*lenp) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
+			/* Only continue writes not past the end of buffer. */
+			len = strlen(data);
+			if (len > maxlen - 1)
+				len = maxlen - 1;
+
+			if (*ppos > len)
+				return 0;
+			len = *ppos;
+		} else {
+			/* Start writing from beginning of buffer. */
+			len = 0;
+		}
+
+		*ppos += *lenp;
+		p = buffer;
+		while ((p - buffer) < *lenp && len < maxlen - 1) {
+			c = *(p++);
+			if (c == 0 || c == '\n')
+				break;
+			data[len++] = c;
+		}
+		data[len] = 0;
+	} else {
+		len = strlen(data);
+		if (len > maxlen)
+			len = maxlen;
+
+		if (*ppos > len) {
+			*lenp = 0;
+			return 0;
+		}
+
+		data += *ppos;
+		len  -= *ppos;
+
+		if (len > *lenp)
+			len = *lenp;
+		if (len)
+			memcpy(buffer, data, len);
+		if (len < *lenp) {
+			buffer[len] = '\n';
+			len++;
+		}
+		*lenp = len;
+		*ppos += len;
+	}
+	return 0;
+}
+
+static void warn_sysctl_write(struct ctl_table *table)
+{
+	pr_warn_once("%s wrote to %s when file position was not 0!\n"
+		"This will not be supported in the future. To silence this\n"
+		"warning, set kernel.sysctl_writes_strict = -1\n",
+		current->comm, table->procname);
+}
+
+/**
+ * proc_first_pos_non_zero_ignore - check if first position is allowed
+ * @ppos: file position
+ * @table: the sysctl table
+ *
+ * Returns true if the first position is non-zero and the sysctl_writes_strict
+ * mode indicates this is not allowed for numeric input types. String proc
+ * handlers can ignore the return value.
+ */
+static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
+					   struct ctl_table *table)
+{
+	if (!*ppos)
+		return false;
+
+	switch (sysctl_writes_strict) {
+	case SYSCTL_WRITES_STRICT:
+		return true;
+	case SYSCTL_WRITES_WARN:
+		warn_sysctl_write(table);
+		return false;
+	default:
+		return false;
+	}
+}
+
+/**
+ * proc_dostring - read a string sysctl
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes a string from/to the user buffer. If the kernel
+ * buffer provided is not large enough to hold the string, the
+ * string is truncated. The copied string is %NULL-terminated.
+ * If the string is being read by the user process, it is copied
+ * and a newline '\n' is added. It is truncated if the buffer is
+ * not large enough.
+ *
+ * Returns 0 on success.
+ */
+int proc_dostring(struct ctl_table *table, int write,
+		  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	if (write)
+		proc_first_pos_non_zero_ignore(ppos, table);
+
+	return _proc_do_string(table->data, table->maxlen, write, buffer, lenp,
+			ppos);
+}
+
+static size_t proc_skip_spaces(char **buf)
+{
+	size_t ret;
+	char *tmp = skip_spaces(*buf);
+	ret = tmp - *buf;
+	*buf = tmp;
+	return ret;
+}
+
+static void proc_skip_char(char **buf, size_t *size, const char v)
+{
+	while (*size) {
+		if (**buf != v)
+			break;
+		(*size)--;
+		(*buf)++;
+	}
+}
+
+/**
+ * strtoul_lenient - parse an ASCII formatted integer from a buffer and only
+ *                   fail on overflow
+ *
+ * @cp: kernel buffer containing the string to parse
+ * @endp: pointer to store the trailing characters
+ * @base: the base to use
+ * @res: where the parsed integer will be stored
+ *
+ * In case of success 0 is returned and @res will contain the parsed integer,
+ * @endp will hold any trailing characters.
+ * This function will fail the parse on overflow. If there wasn't an overflow
+ * the function will defer the decision what characters count as invalid to the
+ * caller.
+ */
+static int strtoul_lenient(const char *cp, char **endp, unsigned int base,
+			   unsigned long *res)
+{
+	unsigned long long result;
+	unsigned int rv;
+
+	cp = _parse_integer_fixup_radix(cp, &base);
+	rv = _parse_integer(cp, base, &result);
+	if ((rv & KSTRTOX_OVERFLOW) || (result != (unsigned long)result))
+		return -ERANGE;
+
+	cp += rv;
+
+	if (endp)
+		*endp = (char *)cp;
+
+	*res = (unsigned long)result;
+	return 0;
+}
+
+#define TMPBUFLEN 22
+/**
+ * proc_get_long - reads an ASCII formatted integer from a user buffer
+ *
+ * @buf: a kernel buffer
+ * @size: size of the kernel buffer
+ * @val: this is where the number will be stored
+ * @neg: set to %TRUE if number is negative
+ * @perm_tr: a vector which contains the allowed trailers
+ * @perm_tr_len: size of the perm_tr vector
+ * @tr: pointer to store the trailer character
+ *
+ * In case of success %0 is returned and @buf and @size are updated with
+ * the amount of bytes read. If @tr is non-NULL and a trailing
+ * character exists (size is non-zero after returning from this
+ * function), @tr is updated with the trailing character.
+ */
+static int proc_get_long(char **buf, size_t *size,
+			  unsigned long *val, bool *neg,
+			  const char *perm_tr, unsigned perm_tr_len, char *tr)
+{
+	int len;
+	char *p, tmp[TMPBUFLEN];
+
+	if (!*size)
+		return -EINVAL;
+
+	len = *size;
+	if (len > TMPBUFLEN - 1)
+		len = TMPBUFLEN - 1;
+
+	memcpy(tmp, *buf, len);
+
+	tmp[len] = 0;
+	p = tmp;
+	if (*p == '-' && *size > 1) {
+		*neg = true;
+		p++;
+	} else
+		*neg = false;
+	if (!isdigit(*p))
+		return -EINVAL;
+
+	if (strtoul_lenient(p, &p, 0, val))
+		return -EINVAL;
+
+	len = p - tmp;
+
+	/* We don't know if the next char is whitespace thus we may accept
+	 * invalid integers (e.g. 1234...a) or two integers instead of one
+	 * (e.g. 123...1). So lets not allow such large numbers. */
+	if (len == TMPBUFLEN - 1)
+		return -EINVAL;
+
+	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
+		return -EINVAL;
+
+	if (tr && (len < *size))
+		*tr = *p;
+
+	*buf += len;
+	*size -= len;
+
+	return 0;
+}
+
+/**
+ * proc_put_long - converts an integer to a decimal ASCII formatted string
+ *
+ * @buf: the user buffer
+ * @size: the size of the user buffer
+ * @val: the integer to be converted
+ * @neg: sign of the number, %TRUE for negative
+ *
+ * In case of success @buf and @size are updated with the amount of bytes
+ * written.
+ */
+static void proc_put_long(void **buf, size_t *size, unsigned long val, bool neg)
+{
+	int len;
+	char tmp[TMPBUFLEN], *p = tmp;
+
+	sprintf(p, "%s%lu", neg ? "-" : "", val);
+	len = strlen(tmp);
+	if (len > *size)
+		len = *size;
+	memcpy(*buf, tmp, len);
+	*size -= len;
+	*buf += len;
+}
+#undef TMPBUFLEN
+
+static void proc_put_char(void **buf, size_t *size, char c)
+{
+	if (*size) {
+		char **buffer = (char **)buf;
+		**buffer = c;
+
+		(*size)--;
+		(*buffer)++;
+		*buf = *buffer;
+	}
+}
+
+static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
+				 int *valp,
+				 int write, void *data)
+{
+	if (write) {
+		if (*negp) {
+			if (*lvalp > (unsigned long) INT_MAX + 1)
+				return -EINVAL;
+			*valp = -*lvalp;
+		} else {
+			if (*lvalp > (unsigned long) INT_MAX)
+				return -EINVAL;
+			*valp = *lvalp;
+		}
+	} else {
+		int val = *valp;
+		if (val < 0) {
+			*negp = true;
+			*lvalp = -(unsigned long)val;
+		} else {
+			*negp = false;
+			*lvalp = (unsigned long)val;
+		}
+	}
+	return 0;
+}
+
+static int do_proc_douintvec_conv(unsigned long *lvalp,
+				  unsigned int *valp,
+				  int write, void *data)
+{
+	if (write) {
+		if (*lvalp > UINT_MAX)
+			return -EINVAL;
+		*valp = *lvalp;
+	} else {
+		unsigned int val = *valp;
+		*lvalp = (unsigned long)val;
+	}
+	return 0;
+}
+
+static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
+
+static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
+		  int write, void *buffer,
+		  size_t *lenp, loff_t *ppos,
+		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
+			      int write, void *data),
+		  void *data)
+{
+	int *i, vleft, first = 1, err = 0;
+	size_t left;
+	char *p;
+	
+	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+	
+	i = (int *) tbl_data;
+	vleft = table->maxlen / sizeof(*i);
+	left = *lenp;
+
+	if (!conv)
+		conv = do_proc_dointvec_conv;
+
+	if (write) {
+		if (proc_first_pos_non_zero_ignore(ppos, table))
+			goto out;
+
+		if (left > PAGE_SIZE - 1)
+			left = PAGE_SIZE - 1;
+		p = buffer;
+	}
+
+	for (; left && vleft--; i++, first=0) {
+		unsigned long lval;
+		bool neg;
+
+		if (write) {
+			left -= proc_skip_spaces(&p);
+
+			if (!left)
+				break;
+			err = proc_get_long(&p, &left, &lval, &neg,
+					     proc_wspace_sep,
+					     sizeof(proc_wspace_sep), NULL);
+			if (err)
+				break;
+			if (conv(&neg, &lval, i, 1, data)) {
+				err = -EINVAL;
+				break;
+			}
+		} else {
+			if (conv(&neg, &lval, i, 0, data)) {
+				err = -EINVAL;
+				break;
+			}
+			if (!first)
+				proc_put_char(&buffer, &left, '\t');
+			proc_put_long(&buffer, &left, lval, neg);
+		}
+	}
+
+	if (!write && !first && left && !err)
+		proc_put_char(&buffer, &left, '\n');
+	if (write && !err && left)
+		left -= proc_skip_spaces(&p);
+	if (write && first)
+		return err ? : -EINVAL;
+	*lenp -= left;
+out:
+	*ppos += *lenp;
+	return err;
+}
+
+static int do_proc_dointvec(struct ctl_table *table, int write,
+		  void *buffer, size_t *lenp, loff_t *ppos,
+		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
+			      int write, void *data),
+		  void *data)
+{
+	return __do_proc_dointvec(table->data, table, write,
+			buffer, lenp, ppos, conv, data);
+}
+
+static int do_proc_douintvec_w(unsigned int *tbl_data,
+			       struct ctl_table *table,
+			       void *buffer,
+			       size_t *lenp, loff_t *ppos,
+			       int (*conv)(unsigned long *lvalp,
+					   unsigned int *valp,
+					   int write, void *data),
+			       void *data)
+{
+	unsigned long lval;
+	int err = 0;
+	size_t left;
+	bool neg;
+	char *p = buffer;
+
+	left = *lenp;
+
+	if (proc_first_pos_non_zero_ignore(ppos, table))
+		goto bail_early;
+
+	if (left > PAGE_SIZE - 1)
+		left = PAGE_SIZE - 1;
+
+	left -= proc_skip_spaces(&p);
+	if (!left) {
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	err = proc_get_long(&p, &left, &lval, &neg,
+			     proc_wspace_sep,
+			     sizeof(proc_wspace_sep), NULL);
+	if (err || neg) {
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	if (conv(&lval, tbl_data, 1, data)) {
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	if (!err && left)
+		left -= proc_skip_spaces(&p);
+
+out_free:
+	if (err)
+		return -EINVAL;
+
+	return 0;
+
+	/* This is in keeping with old __do_proc_dointvec() */
+bail_early:
+	*ppos += *lenp;
+	return err;
+}
+
+static int do_proc_douintvec_r(unsigned int *tbl_data, void *buffer,
+			       size_t *lenp, loff_t *ppos,
+			       int (*conv)(unsigned long *lvalp,
+					   unsigned int *valp,
+					   int write, void *data),
+			       void *data)
+{
+	unsigned long lval;
+	int err = 0;
+	size_t left;
+
+	left = *lenp;
+
+	if (conv(&lval, tbl_data, 0, data)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	proc_put_long(&buffer, &left, lval, false);
+	if (!left)
+		goto out;
+
+	proc_put_char(&buffer, &left, '\n');
+
+out:
+	*lenp -= left;
+	*ppos += *lenp;
+
+	return err;
+}
+
+static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
+			       int write, void *buffer,
+			       size_t *lenp, loff_t *ppos,
+			       int (*conv)(unsigned long *lvalp,
+					   unsigned int *valp,
+					   int write, void *data),
+			       void *data)
+{
+	unsigned int *i, vleft;
+
+	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	i = (unsigned int *) tbl_data;
+	vleft = table->maxlen / sizeof(*i);
+
+	/*
+	 * Arrays are not supported, keep this simple. *Do not* add
+	 * support for them.
+	 */
+	if (vleft != 1) {
+		*lenp = 0;
+		return -EINVAL;
+	}
+
+	if (!conv)
+		conv = do_proc_douintvec_conv;
+
+	if (write)
+		return do_proc_douintvec_w(i, table, buffer, lenp, ppos,
+					   conv, data);
+	return do_proc_douintvec_r(i, buffer, lenp, ppos, conv, data);
+}
+
+static int do_proc_douintvec(struct ctl_table *table, int write,
+			     void *buffer, size_t *lenp, loff_t *ppos,
+			     int (*conv)(unsigned long *lvalp,
+					 unsigned int *valp,
+					 int write, void *data),
+			     void *data)
+{
+	return __do_proc_douintvec(table->data, table, write,
+				   buffer, lenp, ppos, conv, data);
+}
+
+/**
+ * proc_dointvec - read a vector of integers
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
+ * values from/to the user buffer, treated as an ASCII string. 
+ *
+ * Returns 0 on success.
+ */
+int proc_dointvec(struct ctl_table *table, int write, void *buffer,
+		  size_t *lenp, loff_t *ppos)
+{
+	return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
+}
+
+#ifdef CONFIG_COMPACTION
+static int proc_dointvec_minmax_warn_RT_change(struct ctl_table *table,
+		int write, void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int ret, old;
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT) || !write)
+		return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+	old = *(int *)table->data;
+	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+	if (ret)
+		return ret;
+	if (old != *(int *)table->data)
+		pr_warn_once("sysctl attribute %s changed by %s[%d]\n",
+			     table->procname, current->comm,
+			     task_pid_nr(current));
+	return ret;
+}
+#endif
+
+/**
+ * proc_douintvec - read a vector of unsigned integers
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
+ * values from/to the user buffer, treated as an ASCII string.
+ *
+ * Returns 0 on success.
+ */
+int proc_douintvec(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
+{
+	return do_proc_douintvec(table, write, buffer, lenp, ppos,
+				 do_proc_douintvec_conv, NULL);
+}
+
+/*
+ * Taint values can only be increased
+ * This means we can safely use a temporary.
+ */
+static int proc_taint(struct ctl_table *table, int write,
+			       void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct ctl_table t;
+	unsigned long tmptaint = get_taint();
+	int err;
+
+	if (write && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	t = *table;
+	t.data = &tmptaint;
+	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
+	if (err < 0)
+		return err;
+
+	if (write) {
+		int i;
+
+		/*
+		 * If we are relying on panic_on_taint not producing
+		 * false positives due to userspace input, bail out
+		 * before setting the requested taint flags.
+		 */
+		if (panic_on_taint_nousertaint && (tmptaint & panic_on_taint))
+			return -EINVAL;
+
+		/*
+		 * Poor man's atomic or. Not worth adding a primitive
+		 * to everyone's atomic.h for this
+		 */
+		for (i = 0; i < TAINT_FLAGS_COUNT; i++)
+			if ((1UL << i) & tmptaint)
+				add_taint(i, LOCKDEP_STILL_OK);
+	}
+
+	return err;
+}
+
+#ifdef CONFIG_PRINTK
+static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
+{
+	if (write && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+}
+#endif
+
+/**
+ * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
+ * @min: pointer to minimum allowable value
+ * @max: pointer to maximum allowable value
+ *
+ * The do_proc_dointvec_minmax_conv_param structure provides the
+ * minimum and maximum values for doing range checking for those sysctl
+ * parameters that use the proc_dointvec_minmax() handler.
+ */
+struct do_proc_dointvec_minmax_conv_param {
+	int *min;
+	int *max;
+};
+
+static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
+					int *valp,
+					int write, void *data)
+{
+	int tmp, ret;
+	struct do_proc_dointvec_minmax_conv_param *param = data;
+	/*
+	 * If writing, first do so via a temporary local int so we can
+	 * bounds-check it before touching *valp.
+	 */
+	int *ip = write ? &tmp : valp;
+
+	ret = do_proc_dointvec_conv(negp, lvalp, ip, write, data);
+	if (ret)
+		return ret;
+
+	if (write) {
+		if ((param->min && *param->min > tmp) ||
+		    (param->max && *param->max < tmp))
+			return -EINVAL;
+		*valp = tmp;
+	}
+
+	return 0;
+}
+
+/**
+ * proc_dointvec_minmax - read a vector of integers with min/max values
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
+ * values from/to the user buffer, treated as an ASCII string.
+ *
+ * This routine will ensure the values are within the range specified by
+ * table->extra1 (min) and table->extra2 (max).
+ *
+ * Returns 0 on success or -EINVAL on write when the range check fails.
+ */
+int proc_dointvec_minmax(struct ctl_table *table, int write,
+		  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct do_proc_dointvec_minmax_conv_param param = {
+		.min = (int *) table->extra1,
+		.max = (int *) table->extra2,
+	};
+	return do_proc_dointvec(table, write, buffer, lenp, ppos,
+				do_proc_dointvec_minmax_conv, &param);
+}
+
+/**
+ * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() range checking structure
+ * @min: pointer to minimum allowable value
+ * @max: pointer to maximum allowable value
+ *
+ * The do_proc_douintvec_minmax_conv_param structure provides the
+ * minimum and maximum values for doing range checking for those sysctl
+ * parameters that use the proc_douintvec_minmax() handler.
+ */
+struct do_proc_douintvec_minmax_conv_param {
+	unsigned int *min;
+	unsigned int *max;
+};
+
+static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
+					 unsigned int *valp,
+					 int write, void *data)
+{
+	int ret;
+	unsigned int tmp;
+	struct do_proc_douintvec_minmax_conv_param *param = data;
+	/* write via temporary local uint for bounds-checking */
+	unsigned int *up = write ? &tmp : valp;
+
+	ret = do_proc_douintvec_conv(lvalp, up, write, data);
+	if (ret)
+		return ret;
+
+	if (write) {
+		if ((param->min && *param->min > tmp) ||
+		    (param->max && *param->max < tmp))
+			return -ERANGE;
+
+		*valp = tmp;
+	}
+
+	return 0;
+}
+
+/**
+ * proc_douintvec_minmax - read a vector of unsigned ints with min/max values
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
+ * values from/to the user buffer, treated as an ASCII string. Negative
+ * strings are not allowed.
+ *
+ * This routine will ensure the values are within the range specified by
+ * table->extra1 (min) and table->extra2 (max). There is a final sanity
+ * check for UINT_MAX to avoid having to support wrap around uses from
+ * userspace.
+ *
+ * Returns 0 on success or -ERANGE on write when the range check fails.
+ */
+int proc_douintvec_minmax(struct ctl_table *table, int write,
+			  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct do_proc_douintvec_minmax_conv_param param = {
+		.min = (unsigned int *) table->extra1,
+		.max = (unsigned int *) table->extra2,
+	};
+	return do_proc_douintvec(table, write, buffer, lenp, ppos,
+				 do_proc_douintvec_minmax_conv, &param);
+}
+
+static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
+					unsigned int *valp,
+					int write, void *data)
+{
+	if (write) {
+		unsigned int val;
+
+		val = round_pipe_size(*lvalp);
+		if (val == 0)
+			return -EINVAL;
+
+		*valp = val;
+	} else {
+		unsigned int val = *valp;
+		*lvalp = (unsigned long) val;
+	}
+
+	return 0;
+}
+
+static int proc_dopipe_max_size(struct ctl_table *table, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return do_proc_douintvec(table, write, buffer, lenp, ppos,
+				 do_proc_dopipe_max_size_conv, NULL);
+}
+
+static void validate_coredump_safety(void)
+{
+#ifdef CONFIG_COREDUMP
+	if (suid_dumpable == SUID_DUMP_ROOT &&
+	    core_pattern[0] != '/' && core_pattern[0] != '|') {
+		printk(KERN_WARNING
+"Unsafe core_pattern used with fs.suid_dumpable=2.\n"
+"Pipe handler or fully qualified core dump path required.\n"
+"Set kernel.core_pattern before fs.suid_dumpable.\n"
+		);
+	}
+#endif
+}
+
+static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+	if (!error)
+		validate_coredump_safety();
+	return error;
+}
+
+#ifdef CONFIG_COREDUMP
+static int proc_dostring_coredump(struct ctl_table *table, int write,
+		  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int error = proc_dostring(table, write, buffer, lenp, ppos);
+	if (!error)
+		validate_coredump_safety();
+	return error;
+}
+#endif
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static int sysrq_sysctl_handler(struct ctl_table *table, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int tmp, ret;
+
+	tmp = sysrq_mask();
+
+	ret = __do_proc_dointvec(&tmp, table, write, buffer,
+			       lenp, ppos, NULL, NULL);
+	if (ret || !write)
+		return ret;
+
+	if (write)
+		sysrq_toggle_support(tmp);
+
+	return 0;
+}
+#endif
+
+static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
+		int write, void *buffer, size_t *lenp, loff_t *ppos,
+		unsigned long convmul, unsigned long convdiv)
+{
+	unsigned long *i, *min, *max;
+	int vleft, first = 1, err = 0;
+	size_t left;
+	char *p;
+
+	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	i = (unsigned long *) data;
+	min = (unsigned long *) table->extra1;
+	max = (unsigned long *) table->extra2;
+	vleft = table->maxlen / sizeof(unsigned long);
+	left = *lenp;
+
+	if (write) {
+		if (proc_first_pos_non_zero_ignore(ppos, table))
+			goto out;
+
+		if (left > PAGE_SIZE - 1)
+			left = PAGE_SIZE - 1;
+		p = buffer;
+	}
+
+	for (; left && vleft--; i++, first = 0) {
+		unsigned long val;
+
+		if (write) {
+			bool neg;
+
+			left -= proc_skip_spaces(&p);
+			if (!left)
+				break;
+
+			err = proc_get_long(&p, &left, &val, &neg,
+					     proc_wspace_sep,
+					     sizeof(proc_wspace_sep), NULL);
+			if (err)
+				break;
+			if (neg)
+				continue;
+			val = convmul * val / convdiv;
+			if ((min && val < *min) || (max && val > *max)) {
+				err = -EINVAL;
+				break;
+			}
+			*i = val;
+		} else {
+			val = convdiv * (*i) / convmul;
+			if (!first)
+				proc_put_char(&buffer, &left, '\t');
+			proc_put_long(&buffer, &left, val, false);
+		}
+	}
+
+	if (!write && !first && left && !err)
+		proc_put_char(&buffer, &left, '\n');
+	if (write && !err)
+		left -= proc_skip_spaces(&p);
+	if (write && first)
+		return err ? : -EINVAL;
+	*lenp -= left;
+out:
+	*ppos += *lenp;
+	return err;
+}
+
+static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul,
+		unsigned long convdiv)
+{
+	return __do_proc_doulongvec_minmax(table->data, table, write,
+			buffer, lenp, ppos, convmul, convdiv);
+}
+
+/**
+ * proc_doulongvec_minmax - read a vector of long integers with min/max values
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
+ * values from/to the user buffer, treated as an ASCII string.
+ *
+ * This routine will ensure the values are within the range specified by
+ * table->extra1 (min) and table->extra2 (max).
+ *
+ * Returns 0 on success.
+ */
+int proc_doulongvec_minmax(struct ctl_table *table, int write,
+			   void *buffer, size_t *lenp, loff_t *ppos)
+{
+    return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
+}
+
+/**
+ * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
+ * values from/to the user buffer, treated as an ASCII string. The values
+ * are treated as milliseconds, and converted to jiffies when they are stored.
+ *
+ * This routine will ensure the values are within the range specified by
+ * table->extra1 (min) and table->extra2 (max).
+ *
+ * Returns 0 on success.
+ */
+int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
+				      void *buffer, size_t *lenp, loff_t *ppos)
+{
+    return do_proc_doulongvec_minmax(table, write, buffer,
+				     lenp, ppos, HZ, 1000l);
+}
+
+
+static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
+					 int *valp,
+					 int write, void *data)
+{
+	if (write) {
+		if (*lvalp > INT_MAX / HZ)
+			return 1;
+		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
+	} else {
+		int val = *valp;
+		unsigned long lval;
+		if (val < 0) {
+			*negp = true;
+			lval = -(unsigned long)val;
+		} else {
+			*negp = false;
+			lval = (unsigned long)val;
+		}
+		*lvalp = lval / HZ;
+	}
+	return 0;
+}
+
+static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
+						int *valp,
+						int write, void *data)
+{
+	if (write) {
+		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
+			return 1;
+		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
+	} else {
+		int val = *valp;
+		unsigned long lval;
+		if (val < 0) {
+			*negp = true;
+			lval = -(unsigned long)val;
+		} else {
+			*negp = false;
+			lval = (unsigned long)val;
+		}
+		*lvalp = jiffies_to_clock_t(lval);
+	}
+	return 0;
+}
+
+static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
+					    int *valp,
+					    int write, void *data)
+{
+	if (write) {
+		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+
+		if (jif > INT_MAX)
+			return 1;
+		*valp = (int)jif;
+	} else {
+		int val = *valp;
+		unsigned long lval;
+		if (val < 0) {
+			*negp = true;
+			lval = -(unsigned long)val;
+		} else {
+			*negp = false;
+			lval = (unsigned long)val;
+		}
+		*lvalp = jiffies_to_msecs(lval);
+	}
+	return 0;
+}
+
+/**
+ * proc_dointvec_jiffies - read a vector of integers as seconds
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
+ * values from/to the user buffer, treated as an ASCII string. 
+ * The values read are assumed to be in seconds, and are converted into
+ * jiffies.
+ *
+ * Returns 0 on success.
+ */
+int proc_dointvec_jiffies(struct ctl_table *table, int write,
+			  void *buffer, size_t *lenp, loff_t *ppos)
+{
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
+		    	    do_proc_dointvec_jiffies_conv,NULL);
+}
+
+/**
+ * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: pointer to the file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
+ * values from/to the user buffer, treated as an ASCII string. 
+ * The values read are assumed to be in 1/USER_HZ seconds, and 
+ * are converted into jiffies.
+ *
+ * Returns 0 on success.
+ */
+int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
+				 void *buffer, size_t *lenp, loff_t *ppos)
+{
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
+		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
+}
+
+/**
+ * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ * @ppos: the current position in the file
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
+ * values from/to the user buffer, treated as an ASCII string. 
+ * The values read are assumed to be in 1/1000 seconds, and 
+ * are converted into jiffies.
+ *
+ * Returns 0 on success.
+ */
+int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
+{
+	return do_proc_dointvec(table, write, buffer, lenp, ppos,
+				do_proc_dointvec_ms_jiffies_conv, NULL);
+}
+
+static int proc_do_cad_pid(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
+{
+	struct pid *new_pid;
+	pid_t tmp;
+	int r;
+
+	tmp = pid_vnr(cad_pid);
+
+	r = __do_proc_dointvec(&tmp, table, write, buffer,
+			       lenp, ppos, NULL, NULL);
+	if (r || !write)
+		return r;
+
+	new_pid = find_get_pid(tmp);
+	if (!new_pid)
+		return -ESRCH;
+
+	put_pid(xchg(&cad_pid, new_pid));
+	return 0;
+}
+
+/**
+ * proc_do_large_bitmap - read/write from/to a large bitmap
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * The bitmap is stored at table->data and the bitmap length (in bits)
+ * in table->maxlen.
+ *
+ * We use a range comma separated format (e.g. 1,3-4,10-10) so that
+ * large bitmaps may be represented in a compact manner. Writing into
+ * the file will clear the bitmap then update it with the given input.
+ *
+ * Returns 0 on success.
+ */
+int proc_do_large_bitmap(struct ctl_table *table, int write,
+			 void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int err = 0;
+	bool first = 1;
+	size_t left = *lenp;
+	unsigned long bitmap_len = table->maxlen;
+	unsigned long *bitmap = *(unsigned long **) table->data;
+	unsigned long *tmp_bitmap = NULL;
+	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
+
+	if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		char *p = buffer;
+		size_t skipped = 0;
+
+		if (left > PAGE_SIZE - 1) {
+			left = PAGE_SIZE - 1;
+			/* How much of the buffer we'll skip this pass */
+			skipped = *lenp - left;
+		}
+
+		tmp_bitmap = bitmap_zalloc(bitmap_len, GFP_KERNEL);
+		if (!tmp_bitmap)
+			return -ENOMEM;
+		proc_skip_char(&p, &left, '\n');
+		while (!err && left) {
+			unsigned long val_a, val_b;
+			bool neg;
+			size_t saved_left;
+
+			/* In case we stop parsing mid-number, we can reset */
+			saved_left = left;
+			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
+					     sizeof(tr_a), &c);
+			/*
+			 * If we consumed the entirety of a truncated buffer or
+			 * only one char is left (may be a "-"), then stop here,
+			 * reset, & come back for more.
+			 */
+			if ((left <= 1) && skipped) {
+				left = saved_left;
+				break;
+			}
+
+			if (err)
+				break;
+			if (val_a >= bitmap_len || neg) {
+				err = -EINVAL;
+				break;
+			}
+
+			val_b = val_a;
+			if (left) {
+				p++;
+				left--;
+			}
+
+			if (c == '-') {
+				err = proc_get_long(&p, &left, &val_b,
+						     &neg, tr_b, sizeof(tr_b),
+						     &c);
+				/*
+				 * If we consumed all of a truncated buffer or
+				 * then stop here, reset, & come back for more.
+				 */
+				if (!left && skipped) {
+					left = saved_left;
+					break;
+				}
+
+				if (err)
+					break;
+				if (val_b >= bitmap_len || neg ||
+				    val_a > val_b) {
+					err = -EINVAL;
+					break;
+				}
+				if (left) {
+					p++;
+					left--;
+				}
+			}
+
+			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
+			first = 0;
+			proc_skip_char(&p, &left, '\n');
+		}
+		left += skipped;
+	} else {
+		unsigned long bit_a, bit_b = 0;
+
+		while (left) {
+			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
+			if (bit_a >= bitmap_len)
+				break;
+			bit_b = find_next_zero_bit(bitmap, bitmap_len,
+						   bit_a + 1) - 1;
+
+			if (!first)
+				proc_put_char(&buffer, &left, ',');
+			proc_put_long(&buffer, &left, bit_a, false);
+			if (bit_a != bit_b) {
+				proc_put_char(&buffer, &left, '-');
+				proc_put_long(&buffer, &left, bit_b, false);
+			}
+
+			first = 0; bit_b++;
+		}
+		proc_put_char(&buffer, &left, '\n');
+	}
+
+	if (!err) {
+		if (write) {
+			if (*ppos)
+				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
+			else
+				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
+		}
+		*lenp -= left;
+		*ppos += *lenp;
+	}
+
+	bitmap_free(tmp_bitmap);
+	return err;
+}
+
+#else /* CONFIG_PROC_SYSCTL */
+
+int proc_dostring(struct ctl_table *table, int write,
+		  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_dointvec(struct ctl_table *table, int write,
+		  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_douintvec(struct ctl_table *table, int write,
+		  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_dointvec_minmax(struct ctl_table *table, int write,
+		    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_douintvec_minmax(struct ctl_table *table, int write,
+			  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_dointvec_jiffies(struct ctl_table *table, int write,
+		    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
+		    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
+			     void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_doulongvec_minmax(struct ctl_table *table, int write,
+		    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
+				      void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+int proc_do_large_bitmap(struct ctl_table *table, int write,
+			 void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
+#endif /* CONFIG_PROC_SYSCTL */
+
+#if defined(CONFIG_SYSCTL)
+int proc_do_static_key(struct ctl_table *table, int write,
+		       void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct static_key *key = (struct static_key *)table->data;
+	static DEFINE_MUTEX(static_key_mutex);
+	int val, ret;
+	struct ctl_table tmp = {
+		.data   = &val,
+		.maxlen = sizeof(val),
+		.mode   = table->mode,
+		.extra1 = SYSCTL_ZERO,
+		.extra2 = SYSCTL_ONE,
+	};
+
+	if (write && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	mutex_lock(&static_key_mutex);
+	val = static_key_enabled(key);
+	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+	if (write && !ret) {
+		if (val)
+			static_key_enable(key);
+		else
+			static_key_disable(key);
+	}
+	mutex_unlock(&static_key_mutex);
+	return ret;
+}
+
 static struct ctl_table kern_table[] = {
 	{
 		.procname	= "sched_child_runs_first",
@@ -444,6 +1806,20 @@
 		.proc_handler	= sched_rt_handler,
 	},
 	{
+		.procname	= "sched_deadline_period_max_us",
+		.data		= &sysctl_sched_dl_period_max,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "sched_deadline_period_min_us",
+		.data		= &sysctl_sched_dl_period_min,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
 		.procname	= "sched_rr_timeslice_ms",
 		.data		= &sysctl_sched_rr_timeslice,
 		.maxlen		= sizeof(int),
@@ -465,6 +1841,13 @@
 		.mode		= 0644,
 		.proc_handler	= sysctl_sched_uclamp_handler,
 	},
+	{
+		.procname	= "sched_util_clamp_min_rt_default",
+		.data		= &sysctl_sched_uclamp_util_min_rt_default,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= sysctl_sched_uclamp_handler,
+	},
 #endif
 #ifdef CONFIG_SCHED_AUTOGROUP
 	{
@@ -625,7 +2008,7 @@
 		.procname	= "soft-power",
 		.data		= &pwrsw_enabled,
 		.maxlen		= sizeof (int),
-	 	.mode		= 0644,
+		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
 #endif
@@ -747,7 +2130,7 @@
 #ifdef CONFIG_MAGIC_SYSRQ
 	{
 		.procname	= "sysrq",
-		.data		= &__sysrq_enabled,
+		.data		= NULL,
 		.maxlen		= sizeof (int),
 		.mode		= 0644,
 		.proc_handler	= sysrq_sysctl_handler,
@@ -805,15 +2188,6 @@
 		.extra2		= &maxolduid,
 	},
 #ifdef CONFIG_S390
-#ifdef CONFIG_MATHEMU
-	{
-		.procname	= "ieee_emulation_warnings",
-		.data		= &sysctl_ieee_emulation_warnings,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-#endif
 	{
 		.procname	= "userprocess_debug",
 		.data		= &show_unhandled_signals,
@@ -822,6 +2196,17 @@
 		.proc_handler	= proc_dointvec,
 	},
 #endif
+#ifdef CONFIG_SMP
+	{
+		.procname	= "oops_all_cpu_backtrace",
+		.data		= &sysctl_oops_all_cpu_backtrace,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+#endif /* CONFIG_SMP */
 	{
 		.procname	= "pid_max",
 		.data		= &pid_max,
@@ -1015,6 +2400,17 @@
 		.proc_handler   = proc_dointvec,
 	},
 #endif
+
+#if (defined(CONFIG_X86_32) || defined(CONFIG_PARISC)) && \
+	defined(CONFIG_DEBUG_STACKOVERFLOW)
+	{
+		.procname	= "panic_on_stackoverflow",
+		.data		= &sysctl_panic_on_stackoverflow,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#endif
 #if defined(CONFIG_X86)
 	{
 		.procname	= "panic_on_unrecovered_nmi",
@@ -1030,15 +2426,6 @@
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
-	{
-		.procname	= "panic_on_stackoverflow",
-		.data		= &sysctl_panic_on_stackoverflow,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-#endif
 	{
 		.procname	= "bootloader_type",
 		.data		= &bootloader_type,
@@ -1093,7 +2480,7 @@
 		.procname	= "ignore-unaligned-usertrap",
 		.data		= &no_unaligned_warning,
 		.maxlen		= sizeof (int),
-	 	.mode		= 0644,
+		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
 #endif
@@ -1107,6 +2494,17 @@
 	},
 #endif
 #ifdef CONFIG_DETECT_HUNG_TASK
+#ifdef CONFIG_SMP
+	{
+		.procname	= "hung_task_all_cpu_backtrace",
+		.data		= &sysctl_hung_task_all_cpu_backtrace,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+#endif /* CONFIG_SMP */
 	{
 		.procname	= "hung_task_panic",
 		.data		= &sysctl_hung_task_panic,
@@ -1255,20 +2653,19 @@
 		.data		= &sysctl_unprivileged_bpf_disabled,
 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
 		.mode		= 0644,
-		/* only handle a transition from default "0" to "1" */
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ONE,
-		.extra2		= SYSCTL_ONE,
+		.proc_handler	= bpf_unpriv_handler,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &two,
 	},
 	{
 		.procname	= "bpf_stats_enabled",
 		.data		= &bpf_stats_enabled_key.key,
 		.maxlen		= sizeof(bpf_stats_enabled_key),
 		.mode		= 0644,
-		.proc_handler	= proc_do_static_key,
+		.proc_handler	= bpf_stats_handler,
 	},
 #endif
-#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
+#if defined(CONFIG_TREE_RCU)
 	{
 		.procname	= "panic_on_rcu_stall",
 		.data		= &sysctl_panic_on_rcu_stall,
@@ -1299,7 +2696,7 @@
 		.data		= &sysctl_overcommit_memory,
 		.maxlen		= sizeof(sysctl_overcommit_memory),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= overcommit_policy_handler,
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= &two,
 	},
@@ -1341,7 +2738,7 @@
 		.proc_handler	= overcommit_kbytes_handler,
 	},
 	{
-		.procname	= "page-cluster", 
+		.procname	= "page-cluster",
 		.data		= &page_cluster,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
@@ -1412,7 +2809,7 @@
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= SYSCTL_ZERO,
-		.extra2		= &one_hundred,
+		.extra2		= &two_hundred,
 	},
 #ifdef CONFIG_HUGETLB_PAGE
 	{
@@ -1480,6 +2877,15 @@
 		.proc_handler	= sysctl_compaction_handler,
 	},
 	{
+		.procname	= "compaction_proactiveness",
+		.data		= &sysctl_compaction_proactiveness,
+		.maxlen		= sizeof(sysctl_compaction_proactiveness),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &one_hundred,
+	},
+	{
 		.procname	= "extfrag_threshold",
 		.data		= &sysctl_extfrag_threshold,
 		.maxlen		= sizeof(int),
@@ -1493,7 +2899,7 @@
 		.data		= &sysctl_compact_unevictable_allowed,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax_warn_RT_change,
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 	},
@@ -1512,7 +2918,7 @@
 		.data		= &watermark_boost_factor,
 		.maxlen		= sizeof(watermark_boost_factor),
 		.mode		= 0644,
-		.proc_handler	= watermark_boost_factor_sysctl_handler,
+		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= SYSCTL_ZERO,
 	},
 	{
@@ -1532,6 +2938,14 @@
 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
 		.extra1		= SYSCTL_ZERO,
 	},
+	{
+		.procname	= "page_lock_unfairness",
+		.data		= &sysctl_page_lock_unfairness,
+		.maxlen		= sizeof(sysctl_page_lock_unfairness),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+	},
 #ifdef CONFIG_MMU
 	{
 		.procname	= "max_map_count",
@@ -1980,6 +3394,35 @@
 	{ }
 };
 
+static struct ctl_table sysctl_base_table[] = {
+	{
+		.procname	= "kernel",
+		.mode		= 0555,
+		.child		= kern_table,
+	},
+	{
+		.procname	= "vm",
+		.mode		= 0555,
+		.child		= vm_table,
+	},
+	{
+		.procname	= "fs",
+		.mode		= 0555,
+		.child		= fs_table,
+	},
+	{
+		.procname	= "debug",
+		.mode		= 0555,
+		.child		= debug_table,
+	},
+	{
+		.procname	= "dev",
+		.mode		= 0555,
+		.child		= dev_table,
+	},
+	{ }
+};
+
 int __init sysctl_init(void)
 {
 	struct ctl_table_header *hdr;
@@ -1988,1432 +3431,7 @@
 	kmemleak_not_leak(hdr);
 	return 0;
 }
-
 #endif /* CONFIG_SYSCTL */
-
-/*
- * /proc/sys support
- */
-
-#ifdef CONFIG_PROC_SYSCTL
-
-static int _proc_do_string(char *data, int maxlen, int write,
-			   char __user *buffer,
-			   size_t *lenp, loff_t *ppos)
-{
-	size_t len;
-	char __user *p;
-	char c;
-
-	if (!data || !maxlen || !*lenp) {
-		*lenp = 0;
-		return 0;
-	}
-
-	if (write) {
-		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
-			/* Only continue writes not past the end of buffer. */
-			len = strlen(data);
-			if (len > maxlen - 1)
-				len = maxlen - 1;
-
-			if (*ppos > len)
-				return 0;
-			len = *ppos;
-		} else {
-			/* Start writing from beginning of buffer. */
-			len = 0;
-		}
-
-		*ppos += *lenp;
-		p = buffer;
-		while ((p - buffer) < *lenp && len < maxlen - 1) {
-			if (get_user(c, p++))
-				return -EFAULT;
-			if (c == 0 || c == '\n')
-				break;
-			data[len++] = c;
-		}
-		data[len] = 0;
-	} else {
-		len = strlen(data);
-		if (len > maxlen)
-			len = maxlen;
-
-		if (*ppos > len) {
-			*lenp = 0;
-			return 0;
-		}
-
-		data += *ppos;
-		len  -= *ppos;
-
-		if (len > *lenp)
-			len = *lenp;
-		if (len)
-			if (copy_to_user(buffer, data, len))
-				return -EFAULT;
-		if (len < *lenp) {
-			if (put_user('\n', buffer + len))
-				return -EFAULT;
-			len++;
-		}
-		*lenp = len;
-		*ppos += len;
-	}
-	return 0;
-}
-
-static void warn_sysctl_write(struct ctl_table *table)
-{
-	pr_warn_once("%s wrote to %s when file position was not 0!\n"
-		"This will not be supported in the future. To silence this\n"
-		"warning, set kernel.sysctl_writes_strict = -1\n",
-		current->comm, table->procname);
-}
-
-/**
- * proc_first_pos_non_zero_ignore - check if first position is allowed
- * @ppos: file position
- * @table: the sysctl table
- *
- * Returns true if the first position is non-zero and the sysctl_writes_strict
- * mode indicates this is not allowed for numeric input types. String proc
- * handlers can ignore the return value.
- */
-static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
-					   struct ctl_table *table)
-{
-	if (!*ppos)
-		return false;
-
-	switch (sysctl_writes_strict) {
-	case SYSCTL_WRITES_STRICT:
-		return true;
-	case SYSCTL_WRITES_WARN:
-		warn_sysctl_write(table);
-		return false;
-	default:
-		return false;
-	}
-}
-
-/**
- * proc_dostring - read a string sysctl
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes a string from/to the user buffer. If the kernel
- * buffer provided is not large enough to hold the string, the
- * string is truncated. The copied string is %NULL-terminated.
- * If the string is being read by the user process, it is copied
- * and a newline '\n' is added. It is truncated if the buffer is
- * not large enough.
- *
- * Returns 0 on success.
- */
-int proc_dostring(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	if (write)
-		proc_first_pos_non_zero_ignore(ppos, table);
-
-	return _proc_do_string((char *)(table->data), table->maxlen, write,
-			       (char __user *)buffer, lenp, ppos);
-}
-
-static size_t proc_skip_spaces(char **buf)
-{
-	size_t ret;
-	char *tmp = skip_spaces(*buf);
-	ret = tmp - *buf;
-	*buf = tmp;
-	return ret;
-}
-
-static void proc_skip_char(char **buf, size_t *size, const char v)
-{
-	while (*size) {
-		if (**buf != v)
-			break;
-		(*size)--;
-		(*buf)++;
-	}
-}
-
-/**
- * strtoul_lenient - parse an ASCII formatted integer from a buffer and only
- *                   fail on overflow
- *
- * @cp: kernel buffer containing the string to parse
- * @endp: pointer to store the trailing characters
- * @base: the base to use
- * @res: where the parsed integer will be stored
- *
- * In case of success 0 is returned and @res will contain the parsed integer,
- * @endp will hold any trailing characters.
- * This function will fail the parse on overflow. If there wasn't an overflow
- * the function will defer the decision what characters count as invalid to the
- * caller.
- */
-static int strtoul_lenient(const char *cp, char **endp, unsigned int base,
-			   unsigned long *res)
-{
-	unsigned long long result;
-	unsigned int rv;
-
-	cp = _parse_integer_fixup_radix(cp, &base);
-	rv = _parse_integer(cp, base, &result);
-	if ((rv & KSTRTOX_OVERFLOW) || (result != (unsigned long)result))
-		return -ERANGE;
-
-	cp += rv;
-
-	if (endp)
-		*endp = (char *)cp;
-
-	*res = (unsigned long)result;
-	return 0;
-}
-
-#define TMPBUFLEN 22
-/**
- * proc_get_long - reads an ASCII formatted integer from a user buffer
- *
- * @buf: a kernel buffer
- * @size: size of the kernel buffer
- * @val: this is where the number will be stored
- * @neg: set to %TRUE if number is negative
- * @perm_tr: a vector which contains the allowed trailers
- * @perm_tr_len: size of the perm_tr vector
- * @tr: pointer to store the trailer character
- *
- * In case of success %0 is returned and @buf and @size are updated with
- * the amount of bytes read. If @tr is non-NULL and a trailing
- * character exists (size is non-zero after returning from this
- * function), @tr is updated with the trailing character.
- */
-static int proc_get_long(char **buf, size_t *size,
-			  unsigned long *val, bool *neg,
-			  const char *perm_tr, unsigned perm_tr_len, char *tr)
-{
-	int len;
-	char *p, tmp[TMPBUFLEN];
-
-	if (!*size)
-		return -EINVAL;
-
-	len = *size;
-	if (len > TMPBUFLEN - 1)
-		len = TMPBUFLEN - 1;
-
-	memcpy(tmp, *buf, len);
-
-	tmp[len] = 0;
-	p = tmp;
-	if (*p == '-' && *size > 1) {
-		*neg = true;
-		p++;
-	} else
-		*neg = false;
-	if (!isdigit(*p))
-		return -EINVAL;
-
-	if (strtoul_lenient(p, &p, 0, val))
-		return -EINVAL;
-
-	len = p - tmp;
-
-	/* We don't know if the next char is whitespace thus we may accept
-	 * invalid integers (e.g. 1234...a) or two integers instead of one
-	 * (e.g. 123...1). So lets not allow such large numbers. */
-	if (len == TMPBUFLEN - 1)
-		return -EINVAL;
-
-	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
-		return -EINVAL;
-
-	if (tr && (len < *size))
-		*tr = *p;
-
-	*buf += len;
-	*size -= len;
-
-	return 0;
-}
-
-/**
- * proc_put_long - converts an integer to a decimal ASCII formatted string
- *
- * @buf: the user buffer
- * @size: the size of the user buffer
- * @val: the integer to be converted
- * @neg: sign of the number, %TRUE for negative
- *
- * In case of success %0 is returned and @buf and @size are updated with
- * the amount of bytes written.
- */
-static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
-			  bool neg)
-{
-	int len;
-	char tmp[TMPBUFLEN], *p = tmp;
-
-	sprintf(p, "%s%lu", neg ? "-" : "", val);
-	len = strlen(tmp);
-	if (len > *size)
-		len = *size;
-	if (copy_to_user(*buf, tmp, len))
-		return -EFAULT;
-	*size -= len;
-	*buf += len;
-	return 0;
-}
-#undef TMPBUFLEN
-
-static int proc_put_char(void __user **buf, size_t *size, char c)
-{
-	if (*size) {
-		char __user **buffer = (char __user **)buf;
-		if (put_user(c, *buffer))
-			return -EFAULT;
-		(*size)--, (*buffer)++;
-		*buf = *buffer;
-	}
-	return 0;
-}
-
-static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
-				 int *valp,
-				 int write, void *data)
-{
-	if (write) {
-		if (*negp) {
-			if (*lvalp > (unsigned long) INT_MAX + 1)
-				return -EINVAL;
-			*valp = -*lvalp;
-		} else {
-			if (*lvalp > (unsigned long) INT_MAX)
-				return -EINVAL;
-			*valp = *lvalp;
-		}
-	} else {
-		int val = *valp;
-		if (val < 0) {
-			*negp = true;
-			*lvalp = -(unsigned long)val;
-		} else {
-			*negp = false;
-			*lvalp = (unsigned long)val;
-		}
-	}
-	return 0;
-}
-
-static int do_proc_douintvec_conv(unsigned long *lvalp,
-				  unsigned int *valp,
-				  int write, void *data)
-{
-	if (write) {
-		if (*lvalp > UINT_MAX)
-			return -EINVAL;
-		*valp = *lvalp;
-	} else {
-		unsigned int val = *valp;
-		*lvalp = (unsigned long)val;
-	}
-	return 0;
-}
-
-static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
-
-static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
-		  int write, void __user *buffer,
-		  size_t *lenp, loff_t *ppos,
-		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
-			      int write, void *data),
-		  void *data)
-{
-	int *i, vleft, first = 1, err = 0;
-	size_t left;
-	char *kbuf = NULL, *p;
-	
-	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
-		*lenp = 0;
-		return 0;
-	}
-	
-	i = (int *) tbl_data;
-	vleft = table->maxlen / sizeof(*i);
-	left = *lenp;
-
-	if (!conv)
-		conv = do_proc_dointvec_conv;
-
-	if (write) {
-		if (proc_first_pos_non_zero_ignore(ppos, table))
-			goto out;
-
-		if (left > PAGE_SIZE - 1)
-			left = PAGE_SIZE - 1;
-		p = kbuf = memdup_user_nul(buffer, left);
-		if (IS_ERR(kbuf))
-			return PTR_ERR(kbuf);
-	}
-
-	for (; left && vleft--; i++, first=0) {
-		unsigned long lval;
-		bool neg;
-
-		if (write) {
-			left -= proc_skip_spaces(&p);
-
-			if (!left)
-				break;
-			err = proc_get_long(&p, &left, &lval, &neg,
-					     proc_wspace_sep,
-					     sizeof(proc_wspace_sep), NULL);
-			if (err)
-				break;
-			if (conv(&neg, &lval, i, 1, data)) {
-				err = -EINVAL;
-				break;
-			}
-		} else {
-			if (conv(&neg, &lval, i, 0, data)) {
-				err = -EINVAL;
-				break;
-			}
-			if (!first)
-				err = proc_put_char(&buffer, &left, '\t');
-			if (err)
-				break;
-			err = proc_put_long(&buffer, &left, lval, neg);
-			if (err)
-				break;
-		}
-	}
-
-	if (!write && !first && left && !err)
-		err = proc_put_char(&buffer, &left, '\n');
-	if (write && !err && left)
-		left -= proc_skip_spaces(&p);
-	if (write) {
-		kfree(kbuf);
-		if (first)
-			return err ? : -EINVAL;
-	}
-	*lenp -= left;
-out:
-	*ppos += *lenp;
-	return err;
-}
-
-static int do_proc_dointvec(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos,
-		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
-			      int write, void *data),
-		  void *data)
-{
-	return __do_proc_dointvec(table->data, table, write,
-			buffer, lenp, ppos, conv, data);
-}
-
-static int do_proc_douintvec_w(unsigned int *tbl_data,
-			       struct ctl_table *table,
-			       void __user *buffer,
-			       size_t *lenp, loff_t *ppos,
-			       int (*conv)(unsigned long *lvalp,
-					   unsigned int *valp,
-					   int write, void *data),
-			       void *data)
-{
-	unsigned long lval;
-	int err = 0;
-	size_t left;
-	bool neg;
-	char *kbuf = NULL, *p;
-
-	left = *lenp;
-
-	if (proc_first_pos_non_zero_ignore(ppos, table))
-		goto bail_early;
-
-	if (left > PAGE_SIZE - 1)
-		left = PAGE_SIZE - 1;
-
-	p = kbuf = memdup_user_nul(buffer, left);
-	if (IS_ERR(kbuf))
-		return -EINVAL;
-
-	left -= proc_skip_spaces(&p);
-	if (!left) {
-		err = -EINVAL;
-		goto out_free;
-	}
-
-	err = proc_get_long(&p, &left, &lval, &neg,
-			     proc_wspace_sep,
-			     sizeof(proc_wspace_sep), NULL);
-	if (err || neg) {
-		err = -EINVAL;
-		goto out_free;
-	}
-
-	if (conv(&lval, tbl_data, 1, data)) {
-		err = -EINVAL;
-		goto out_free;
-	}
-
-	if (!err && left)
-		left -= proc_skip_spaces(&p);
-
-out_free:
-	kfree(kbuf);
-	if (err)
-		return -EINVAL;
-
-	return 0;
-
-	/* This is in keeping with old __do_proc_dointvec() */
-bail_early:
-	*ppos += *lenp;
-	return err;
-}
-
-static int do_proc_douintvec_r(unsigned int *tbl_data, void __user *buffer,
-			       size_t *lenp, loff_t *ppos,
-			       int (*conv)(unsigned long *lvalp,
-					   unsigned int *valp,
-					   int write, void *data),
-			       void *data)
-{
-	unsigned long lval;
-	int err = 0;
-	size_t left;
-
-	left = *lenp;
-
-	if (conv(&lval, tbl_data, 0, data)) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	err = proc_put_long(&buffer, &left, lval, false);
-	if (err || !left)
-		goto out;
-
-	err = proc_put_char(&buffer, &left, '\n');
-
-out:
-	*lenp -= left;
-	*ppos += *lenp;
-
-	return err;
-}
-
-static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
-			       int write, void __user *buffer,
-			       size_t *lenp, loff_t *ppos,
-			       int (*conv)(unsigned long *lvalp,
-					   unsigned int *valp,
-					   int write, void *data),
-			       void *data)
-{
-	unsigned int *i, vleft;
-
-	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
-		*lenp = 0;
-		return 0;
-	}
-
-	i = (unsigned int *) tbl_data;
-	vleft = table->maxlen / sizeof(*i);
-
-	/*
-	 * Arrays are not supported, keep this simple. *Do not* add
-	 * support for them.
-	 */
-	if (vleft != 1) {
-		*lenp = 0;
-		return -EINVAL;
-	}
-
-	if (!conv)
-		conv = do_proc_douintvec_conv;
-
-	if (write)
-		return do_proc_douintvec_w(i, table, buffer, lenp, ppos,
-					   conv, data);
-	return do_proc_douintvec_r(i, buffer, lenp, ppos, conv, data);
-}
-
-static int do_proc_douintvec(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos,
-			     int (*conv)(unsigned long *lvalp,
-					 unsigned int *valp,
-					 int write, void *data),
-			     void *data)
-{
-	return __do_proc_douintvec(table->data, table, write,
-				   buffer, lenp, ppos, conv, data);
-}
-
-/**
- * proc_dointvec - read a vector of integers
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
- * values from/to the user buffer, treated as an ASCII string. 
- *
- * Returns 0 on success.
- */
-int proc_dointvec(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
-}
-
-/**
- * proc_douintvec - read a vector of unsigned integers
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
- * values from/to the user buffer, treated as an ASCII string.
- *
- * Returns 0 on success.
- */
-int proc_douintvec(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return do_proc_douintvec(table, write, buffer, lenp, ppos,
-				 do_proc_douintvec_conv, NULL);
-}
-
-/*
- * Taint values can only be increased
- * This means we can safely use a temporary.
- */
-static int proc_taint(struct ctl_table *table, int write,
-			       void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct ctl_table t;
-	unsigned long tmptaint = get_taint();
-	int err;
-
-	if (write && !capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	t = *table;
-	t.data = &tmptaint;
-	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
-	if (err < 0)
-		return err;
-
-	if (write) {
-		/*
-		 * Poor man's atomic or. Not worth adding a primitive
-		 * to everyone's atomic.h for this
-		 */
-		int i;
-		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
-			if ((tmptaint >> i) & 1)
-				add_taint(i, LOCKDEP_STILL_OK);
-		}
-	}
-
-	return err;
-}
-
-#ifdef CONFIG_PRINTK
-static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	if (write && !capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-}
-#endif
-
-/**
- * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
- * @min: pointer to minimum allowable value
- * @max: pointer to maximum allowable value
- *
- * The do_proc_dointvec_minmax_conv_param structure provides the
- * minimum and maximum values for doing range checking for those sysctl
- * parameters that use the proc_dointvec_minmax() handler.
- */
-struct do_proc_dointvec_minmax_conv_param {
-	int *min;
-	int *max;
-};
-
-static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
-					int *valp,
-					int write, void *data)
-{
-	int tmp, ret;
-	struct do_proc_dointvec_minmax_conv_param *param = data;
-	/*
-	 * If writing, first do so via a temporary local int so we can
-	 * bounds-check it before touching *valp.
-	 */
-	int *ip = write ? &tmp : valp;
-
-	ret = do_proc_dointvec_conv(negp, lvalp, ip, write, data);
-	if (ret)
-		return ret;
-
-	if (write) {
-		if ((param->min && *param->min > tmp) ||
-		    (param->max && *param->max < tmp))
-			return -EINVAL;
-		*valp = tmp;
-	}
-
-	return 0;
-}
-
-/**
- * proc_dointvec_minmax - read a vector of integers with min/max values
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
- * values from/to the user buffer, treated as an ASCII string.
- *
- * This routine will ensure the values are within the range specified by
- * table->extra1 (min) and table->extra2 (max).
- *
- * Returns 0 on success or -EINVAL on write when the range check fails.
- */
-int proc_dointvec_minmax(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct do_proc_dointvec_minmax_conv_param param = {
-		.min = (int *) table->extra1,
-		.max = (int *) table->extra2,
-	};
-	return do_proc_dointvec(table, write, buffer, lenp, ppos,
-				do_proc_dointvec_minmax_conv, &param);
-}
-
-/**
- * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() range checking structure
- * @min: pointer to minimum allowable value
- * @max: pointer to maximum allowable value
- *
- * The do_proc_douintvec_minmax_conv_param structure provides the
- * minimum and maximum values for doing range checking for those sysctl
- * parameters that use the proc_douintvec_minmax() handler.
- */
-struct do_proc_douintvec_minmax_conv_param {
-	unsigned int *min;
-	unsigned int *max;
-};
-
-static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
-					 unsigned int *valp,
-					 int write, void *data)
-{
-	int ret;
-	unsigned int tmp;
-	struct do_proc_douintvec_minmax_conv_param *param = data;
-	/* write via temporary local uint for bounds-checking */
-	unsigned int *up = write ? &tmp : valp;
-
-	ret = do_proc_douintvec_conv(lvalp, up, write, data);
-	if (ret)
-		return ret;
-
-	if (write) {
-		if ((param->min && *param->min > tmp) ||
-		    (param->max && *param->max < tmp))
-			return -ERANGE;
-
-		*valp = tmp;
-	}
-
-	return 0;
-}
-
-/**
- * proc_douintvec_minmax - read a vector of unsigned ints with min/max values
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
- * values from/to the user buffer, treated as an ASCII string. Negative
- * strings are not allowed.
- *
- * This routine will ensure the values are within the range specified by
- * table->extra1 (min) and table->extra2 (max). There is a final sanity
- * check for UINT_MAX to avoid having to support wrap around uses from
- * userspace.
- *
- * Returns 0 on success or -ERANGE on write when the range check fails.
- */
-int proc_douintvec_minmax(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct do_proc_douintvec_minmax_conv_param param = {
-		.min = (unsigned int *) table->extra1,
-		.max = (unsigned int *) table->extra2,
-	};
-	return do_proc_douintvec(table, write, buffer, lenp, ppos,
-				 do_proc_douintvec_minmax_conv, &param);
-}
-
-static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
-					unsigned int *valp,
-					int write, void *data)
-{
-	if (write) {
-		unsigned int val;
-
-		val = round_pipe_size(*lvalp);
-		if (val == 0)
-			return -EINVAL;
-
-		*valp = val;
-	} else {
-		unsigned int val = *valp;
-		*lvalp = (unsigned long) val;
-	}
-
-	return 0;
-}
-
-static int proc_dopipe_max_size(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return do_proc_douintvec(table, write, buffer, lenp, ppos,
-				 do_proc_dopipe_max_size_conv, NULL);
-}
-
-static void validate_coredump_safety(void)
-{
-#ifdef CONFIG_COREDUMP
-	if (suid_dumpable == SUID_DUMP_ROOT &&
-	    core_pattern[0] != '/' && core_pattern[0] != '|') {
-		printk(KERN_WARNING
-"Unsafe core_pattern used with fs.suid_dumpable=2.\n"
-"Pipe handler or fully qualified core dump path required.\n"
-"Set kernel.core_pattern before fs.suid_dumpable.\n"
-		);
-	}
-#endif
-}
-
-static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-	if (!error)
-		validate_coredump_safety();
-	return error;
-}
-
-#ifdef CONFIG_COREDUMP
-static int proc_dostring_coredump(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	int error = proc_dostring(table, write, buffer, lenp, ppos);
-	if (!error)
-		validate_coredump_safety();
-	return error;
-}
-#endif
-
-static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
-				     void __user *buffer,
-				     size_t *lenp, loff_t *ppos,
-				     unsigned long convmul,
-				     unsigned long convdiv)
-{
-	unsigned long *i, *min, *max;
-	int vleft, first = 1, err = 0;
-	size_t left;
-	char *kbuf = NULL, *p;
-
-	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
-		*lenp = 0;
-		return 0;
-	}
-
-	i = (unsigned long *) data;
-	min = (unsigned long *) table->extra1;
-	max = (unsigned long *) table->extra2;
-	vleft = table->maxlen / sizeof(unsigned long);
-	left = *lenp;
-
-	if (write) {
-		if (proc_first_pos_non_zero_ignore(ppos, table))
-			goto out;
-
-		if (left > PAGE_SIZE - 1)
-			left = PAGE_SIZE - 1;
-		p = kbuf = memdup_user_nul(buffer, left);
-		if (IS_ERR(kbuf))
-			return PTR_ERR(kbuf);
-	}
-
-	for (; left && vleft--; i++, first = 0) {
-		unsigned long val;
-
-		if (write) {
-			bool neg;
-
-			left -= proc_skip_spaces(&p);
-			if (!left)
-				break;
-
-			err = proc_get_long(&p, &left, &val, &neg,
-					     proc_wspace_sep,
-					     sizeof(proc_wspace_sep), NULL);
-			if (err)
-				break;
-			if (neg)
-				continue;
-			val = convmul * val / convdiv;
-			if ((min && val < *min) || (max && val > *max)) {
-				err = -EINVAL;
-				break;
-			}
-			*i = val;
-		} else {
-			val = convdiv * (*i) / convmul;
-			if (!first) {
-				err = proc_put_char(&buffer, &left, '\t');
-				if (err)
-					break;
-			}
-			err = proc_put_long(&buffer, &left, val, false);
-			if (err)
-				break;
-		}
-	}
-
-	if (!write && !first && left && !err)
-		err = proc_put_char(&buffer, &left, '\n');
-	if (write && !err)
-		left -= proc_skip_spaces(&p);
-	if (write) {
-		kfree(kbuf);
-		if (first)
-			return err ? : -EINVAL;
-	}
-	*lenp -= left;
-out:
-	*ppos += *lenp;
-	return err;
-}
-
-static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
-				     void __user *buffer,
-				     size_t *lenp, loff_t *ppos,
-				     unsigned long convmul,
-				     unsigned long convdiv)
-{
-	return __do_proc_doulongvec_minmax(table->data, table, write,
-			buffer, lenp, ppos, convmul, convdiv);
-}
-
-/**
- * proc_doulongvec_minmax - read a vector of long integers with min/max values
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
- * values from/to the user buffer, treated as an ASCII string.
- *
- * This routine will ensure the values are within the range specified by
- * table->extra1 (min) and table->extra2 (max).
- *
- * Returns 0 on success.
- */
-int proc_doulongvec_minmax(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-    return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
-}
-
-/**
- * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
- * values from/to the user buffer, treated as an ASCII string. The values
- * are treated as milliseconds, and converted to jiffies when they are stored.
- *
- * This routine will ensure the values are within the range specified by
- * table->extra1 (min) and table->extra2 (max).
- *
- * Returns 0 on success.
- */
-int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-				      void __user *buffer,
-				      size_t *lenp, loff_t *ppos)
-{
-    return do_proc_doulongvec_minmax(table, write, buffer,
-				     lenp, ppos, HZ, 1000l);
-}
-
-
-static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
-					 int *valp,
-					 int write, void *data)
-{
-	if (write) {
-		if (*lvalp > INT_MAX / HZ)
-			return 1;
-		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
-	} else {
-		int val = *valp;
-		unsigned long lval;
-		if (val < 0) {
-			*negp = true;
-			lval = -(unsigned long)val;
-		} else {
-			*negp = false;
-			lval = (unsigned long)val;
-		}
-		*lvalp = lval / HZ;
-	}
-	return 0;
-}
-
-static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
-						int *valp,
-						int write, void *data)
-{
-	if (write) {
-		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
-			return 1;
-		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
-	} else {
-		int val = *valp;
-		unsigned long lval;
-		if (val < 0) {
-			*negp = true;
-			lval = -(unsigned long)val;
-		} else {
-			*negp = false;
-			lval = (unsigned long)val;
-		}
-		*lvalp = jiffies_to_clock_t(lval);
-	}
-	return 0;
-}
-
-static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
-					    int *valp,
-					    int write, void *data)
-{
-	if (write) {
-		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
-
-		if (jif > INT_MAX)
-			return 1;
-		*valp = (int)jif;
-	} else {
-		int val = *valp;
-		unsigned long lval;
-		if (val < 0) {
-			*negp = true;
-			lval = -(unsigned long)val;
-		} else {
-			*negp = false;
-			lval = (unsigned long)val;
-		}
-		*lvalp = jiffies_to_msecs(lval);
-	}
-	return 0;
-}
-
-/**
- * proc_dointvec_jiffies - read a vector of integers as seconds
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
- * values from/to the user buffer, treated as an ASCII string. 
- * The values read are assumed to be in seconds, and are converted into
- * jiffies.
- *
- * Returns 0 on success.
- */
-int proc_dointvec_jiffies(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-    return do_proc_dointvec(table,write,buffer,lenp,ppos,
-		    	    do_proc_dointvec_jiffies_conv,NULL);
-}
-
-/**
- * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: pointer to the file position
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
- * values from/to the user buffer, treated as an ASCII string. 
- * The values read are assumed to be in 1/USER_HZ seconds, and 
- * are converted into jiffies.
- *
- * Returns 0 on success.
- */
-int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-    return do_proc_dointvec(table,write,buffer,lenp,ppos,
-		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
-}
-
-/**
- * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- * @ppos: the current position in the file
- *
- * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
- * values from/to the user buffer, treated as an ASCII string. 
- * The values read are assumed to be in 1/1000 seconds, and 
- * are converted into jiffies.
- *
- * Returns 0 on success.
- */
-int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return do_proc_dointvec(table, write, buffer, lenp, ppos,
-				do_proc_dointvec_ms_jiffies_conv, NULL);
-}
-
-static int proc_do_cad_pid(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct pid *new_pid;
-	pid_t tmp;
-	int r;
-
-	tmp = pid_vnr(cad_pid);
-
-	r = __do_proc_dointvec(&tmp, table, write, buffer,
-			       lenp, ppos, NULL, NULL);
-	if (r || !write)
-		return r;
-
-	new_pid = find_get_pid(tmp);
-	if (!new_pid)
-		return -ESRCH;
-
-	put_pid(xchg(&cad_pid, new_pid));
-	return 0;
-}
-
-/**
- * proc_do_large_bitmap - read/write from/to a large bitmap
- * @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
- * @buffer: the user buffer
- * @lenp: the size of the user buffer
- * @ppos: file position
- *
- * The bitmap is stored at table->data and the bitmap length (in bits)
- * in table->maxlen.
- *
- * We use a range comma separated format (e.g. 1,3-4,10-10) so that
- * large bitmaps may be represented in a compact manner. Writing into
- * the file will clear the bitmap then update it with the given input.
- *
- * Returns 0 on success.
- */
-int proc_do_large_bitmap(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	int err = 0;
-	bool first = 1;
-	size_t left = *lenp;
-	unsigned long bitmap_len = table->maxlen;
-	unsigned long *bitmap = *(unsigned long **) table->data;
-	unsigned long *tmp_bitmap = NULL;
-	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
-
-	if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
-		*lenp = 0;
-		return 0;
-	}
-
-	if (write) {
-		char *kbuf, *p;
-		size_t skipped = 0;
-
-		if (left > PAGE_SIZE - 1) {
-			left = PAGE_SIZE - 1;
-			/* How much of the buffer we'll skip this pass */
-			skipped = *lenp - left;
-		}
-
-		p = kbuf = memdup_user_nul(buffer, left);
-		if (IS_ERR(kbuf))
-			return PTR_ERR(kbuf);
-
-		tmp_bitmap = bitmap_zalloc(bitmap_len, GFP_KERNEL);
-		if (!tmp_bitmap) {
-			kfree(kbuf);
-			return -ENOMEM;
-		}
-		proc_skip_char(&p, &left, '\n');
-		while (!err && left) {
-			unsigned long val_a, val_b;
-			bool neg;
-			size_t saved_left;
-
-			/* In case we stop parsing mid-number, we can reset */
-			saved_left = left;
-			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
-					     sizeof(tr_a), &c);
-			/*
-			 * If we consumed the entirety of a truncated buffer or
-			 * only one char is left (may be a "-"), then stop here,
-			 * reset, & come back for more.
-			 */
-			if ((left <= 1) && skipped) {
-				left = saved_left;
-				break;
-			}
-
-			if (err)
-				break;
-			if (val_a >= bitmap_len || neg) {
-				err = -EINVAL;
-				break;
-			}
-
-			val_b = val_a;
-			if (left) {
-				p++;
-				left--;
-			}
-
-			if (c == '-') {
-				err = proc_get_long(&p, &left, &val_b,
-						     &neg, tr_b, sizeof(tr_b),
-						     &c);
-				/*
-				 * If we consumed all of a truncated buffer or
-				 * then stop here, reset, & come back for more.
-				 */
-				if (!left && skipped) {
-					left = saved_left;
-					break;
-				}
-
-				if (err)
-					break;
-				if (val_b >= bitmap_len || neg ||
-				    val_a > val_b) {
-					err = -EINVAL;
-					break;
-				}
-				if (left) {
-					p++;
-					left--;
-				}
-			}
-
-			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
-			first = 0;
-			proc_skip_char(&p, &left, '\n');
-		}
-		kfree(kbuf);
-		left += skipped;
-	} else {
-		unsigned long bit_a, bit_b = 0;
-
-		while (left) {
-			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
-			if (bit_a >= bitmap_len)
-				break;
-			bit_b = find_next_zero_bit(bitmap, bitmap_len,
-						   bit_a + 1) - 1;
-
-			if (!first) {
-				err = proc_put_char(&buffer, &left, ',');
-				if (err)
-					break;
-			}
-			err = proc_put_long(&buffer, &left, bit_a, false);
-			if (err)
-				break;
-			if (bit_a != bit_b) {
-				err = proc_put_char(&buffer, &left, '-');
-				if (err)
-					break;
-				err = proc_put_long(&buffer, &left, bit_b, false);
-				if (err)
-					break;
-			}
-
-			first = 0; bit_b++;
-		}
-		if (!err)
-			err = proc_put_char(&buffer, &left, '\n');
-	}
-
-	if (!err) {
-		if (write) {
-			if (*ppos)
-				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
-			else
-				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
-		}
-		*lenp -= left;
-		*ppos += *lenp;
-	}
-
-	bitmap_free(tmp_bitmap);
-	return err;
-}
-
-#else /* CONFIG_PROC_SYSCTL */
-
-int proc_dostring(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_dointvec(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_douintvec(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_dointvec_minmax(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_douintvec_minmax(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_dointvec_jiffies(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_doulongvec_minmax(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-				      void __user *buffer,
-				      size_t *lenp, loff_t *ppos)
-{
-    return -ENOSYS;
-}
-
-int proc_do_large_bitmap(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-#endif /* CONFIG_PROC_SYSCTL */
-
-#if defined(CONFIG_SYSCTL)
-int proc_do_static_key(struct ctl_table *table, int write,
-		       void __user *buffer, size_t *lenp,
-		       loff_t *ppos)
-{
-	struct static_key *key = (struct static_key *)table->data;
-	static DEFINE_MUTEX(static_key_mutex);
-	int val, ret;
-	struct ctl_table tmp = {
-		.data   = &val,
-		.maxlen = sizeof(val),
-		.mode   = table->mode,
-		.extra1 = SYSCTL_ZERO,
-		.extra2 = SYSCTL_ONE,
-	};
-
-	if (write && !capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	mutex_lock(&static_key_mutex);
-	val = static_key_enabled(key);
-	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
-	if (write && !ret) {
-		if (val)
-			static_key_enable(key);
-		else
-			static_key_disable(key);
-	}
-	mutex_unlock(&static_key_mutex);
-	return ret;
-}
-#endif
 /*
  * No sense putting this after each symbol definition, twice,
  * exception granted :-)
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
deleted file mode 100644
index 73c1320..0000000
--- a/kernel/sysctl_binary.c
+++ /dev/null
@@ -1,1476 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/stat.h>
-#include <linux/sysctl.h>
-#include "../fs/xfs/xfs_sysctl.h"
-#include <linux/sunrpc/debug.h>
-#include <linux/string.h>
-#include <linux/syscalls.h>
-#include <linux/namei.h>
-#include <linux/mount.h>
-#include <linux/fs.h>
-#include <linux/nsproxy.h>
-#include <linux/pid_namespace.h>
-#include <linux/file.h>
-#include <linux/ctype.h>
-#include <linux/netdevice.h>
-#include <linux/kernel.h>
-#include <linux/uuid.h>
-#include <linux/slab.h>
-#include <linux/compat.h>
-
-#ifdef CONFIG_SYSCTL_SYSCALL
-
-struct bin_table;
-typedef ssize_t bin_convert_t(struct file *file,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen);
-
-static bin_convert_t bin_dir;
-static bin_convert_t bin_string;
-static bin_convert_t bin_intvec;
-static bin_convert_t bin_ulongvec;
-static bin_convert_t bin_uuid;
-static bin_convert_t bin_dn_node_address;
-
-#define CTL_DIR   bin_dir
-#define CTL_STR   bin_string
-#define CTL_INT   bin_intvec
-#define CTL_ULONG bin_ulongvec
-#define CTL_UUID  bin_uuid
-#define CTL_DNADR bin_dn_node_address
-
-#define BUFSZ 256
-
-struct bin_table {
-	bin_convert_t		*convert;
-	int			ctl_name;
-	const char		*procname;
-	const struct bin_table	*child;
-};
-
-static const struct bin_table bin_random_table[] = {
-	{ CTL_INT,	RANDOM_POOLSIZE,	"poolsize" },
-	{ CTL_INT,	RANDOM_ENTROPY_COUNT,	"entropy_avail" },
-	{ CTL_INT,	RANDOM_READ_THRESH,	"read_wakeup_threshold" },
-	{ CTL_INT,	RANDOM_WRITE_THRESH,	"write_wakeup_threshold" },
-	{ CTL_UUID,	RANDOM_BOOT_ID,		"boot_id" },
-	{ CTL_UUID,	RANDOM_UUID,		"uuid" },
-	{}
-};
-
-static const struct bin_table bin_pty_table[] = {
-	{ CTL_INT,	PTY_MAX,	"max" },
-	{ CTL_INT,	PTY_NR,		"nr" },
-	{}
-};
-
-static const struct bin_table bin_kern_table[] = {
-	{ CTL_STR,	KERN_OSTYPE,			"ostype" },
-	{ CTL_STR,	KERN_OSRELEASE,			"osrelease" },
-	/* KERN_OSREV not used */
-	{ CTL_STR,	KERN_VERSION,			"version" },
-	/* KERN_SECUREMASK not used */
-	/* KERN_PROF not used */
-	{ CTL_STR,	KERN_NODENAME,			"hostname" },
-	{ CTL_STR,	KERN_DOMAINNAME,		"domainname" },
-
-	{ CTL_INT,	KERN_PANIC,			"panic" },
-	{ CTL_INT,	KERN_REALROOTDEV,		"real-root-dev" },
-
-	{ CTL_STR,	KERN_SPARC_REBOOT,		"reboot-cmd" },
-	{ CTL_INT,	KERN_CTLALTDEL,			"ctrl-alt-del" },
-	{ CTL_INT,	KERN_PRINTK,			"printk" },
-
-	/* KERN_NAMETRANS not used */
-	/* KERN_PPC_HTABRECLAIM not used */
-	/* KERN_PPC_ZEROPAGED not used */
-	{ CTL_INT,	KERN_PPC_POWERSAVE_NAP,		"powersave-nap" },
-
-	{ CTL_STR,	KERN_MODPROBE,			"modprobe" },
-	{ CTL_INT,	KERN_SG_BIG_BUFF,		"sg-big-buff" },
-	{ CTL_INT,	KERN_ACCT,			"acct" },
-	/* KERN_PPC_L2CR "l2cr" no longer used */
-
-	/* KERN_RTSIGNR not used */
-	/* KERN_RTSIGMAX not used */
-
-	{ CTL_ULONG,	KERN_SHMMAX,			"shmmax" },
-	{ CTL_INT,	KERN_MSGMAX,			"msgmax" },
-	{ CTL_INT,	KERN_MSGMNB,			"msgmnb" },
-	/* KERN_MSGPOOL not used*/
-	{ CTL_INT,	KERN_SYSRQ,			"sysrq" },
-	{ CTL_INT,	KERN_MAX_THREADS,		"threads-max" },
-	{ CTL_DIR,	KERN_RANDOM,			"random",	bin_random_table },
-	{ CTL_ULONG,	KERN_SHMALL,			"shmall" },
-	{ CTL_INT,	KERN_MSGMNI,			"msgmni" },
-	{ CTL_INT,	KERN_SEM,			"sem" },
-	{ CTL_INT,	KERN_SPARC_STOP_A,		"stop-a" },
-	{ CTL_INT,	KERN_SHMMNI,			"shmmni" },
-
-	{ CTL_INT,	KERN_OVERFLOWUID,		"overflowuid" },
-	{ CTL_INT,	KERN_OVERFLOWGID,		"overflowgid" },
-
-	{ CTL_STR,	KERN_HOTPLUG,			"hotplug", },
-	{ CTL_INT,	KERN_IEEE_EMULATION_WARNINGS,	"ieee_emulation_warnings" },
-
-	{ CTL_INT,	KERN_S390_USER_DEBUG_LOGGING,	"userprocess_debug" },
-	{ CTL_INT,	KERN_CORE_USES_PID,		"core_uses_pid" },
-	/* KERN_TAINTED "tainted" no longer used */
-	{ CTL_INT,	KERN_CADPID,			"cad_pid" },
-	{ CTL_INT,	KERN_PIDMAX,			"pid_max" },
-	{ CTL_STR,	KERN_CORE_PATTERN,		"core_pattern" },
-	{ CTL_INT,	KERN_PANIC_ON_OOPS,		"panic_on_oops" },
-	{ CTL_INT,	KERN_HPPA_PWRSW,		"soft-power" },
-	{ CTL_INT,	KERN_HPPA_UNALIGNED,		"unaligned-trap" },
-
-	{ CTL_INT,	KERN_PRINTK_RATELIMIT,		"printk_ratelimit" },
-	{ CTL_INT,	KERN_PRINTK_RATELIMIT_BURST,	"printk_ratelimit_burst" },
-
-	{ CTL_DIR,	KERN_PTY,			"pty",		bin_pty_table },
-	{ CTL_INT,	KERN_NGROUPS_MAX,		"ngroups_max" },
-	{ CTL_INT,	KERN_SPARC_SCONS_PWROFF,	"scons-poweroff" },
-	/* KERN_HZ_TIMER "hz_timer" no longer used */
-	{ CTL_INT,	KERN_UNKNOWN_NMI_PANIC,		"unknown_nmi_panic" },
-	{ CTL_INT,	KERN_BOOTLOADER_TYPE,		"bootloader_type" },
-	{ CTL_INT,	KERN_RANDOMIZE,			"randomize_va_space" },
-
-	{ CTL_INT,	KERN_SPIN_RETRY,		"spin_retry" },
-	/* KERN_ACPI_VIDEO_FLAGS "acpi_video_flags" no longer used */
-	{ CTL_INT,	KERN_IA64_UNALIGNED,		"ignore-unaligned-usertrap" },
-	{ CTL_INT,	KERN_COMPAT_LOG,		"compat-log" },
-	{ CTL_INT,	KERN_MAX_LOCK_DEPTH,		"max_lock_depth" },
-	{ CTL_INT,	KERN_PANIC_ON_NMI,		"panic_on_unrecovered_nmi" },
-	{ CTL_INT,	KERN_PANIC_ON_WARN,		"panic_on_warn" },
-	{ CTL_ULONG,	KERN_PANIC_PRINT,		"panic_print" },
-	{}
-};
-
-static const struct bin_table bin_vm_table[] = {
-	{ CTL_INT,	VM_OVERCOMMIT_MEMORY,		"overcommit_memory" },
-	{ CTL_INT,	VM_PAGE_CLUSTER,		"page-cluster" },
-	{ CTL_INT,	VM_DIRTY_BACKGROUND,		"dirty_background_ratio" },
-	{ CTL_INT,	VM_DIRTY_RATIO,			"dirty_ratio" },
-	/* VM_DIRTY_WB_CS "dirty_writeback_centisecs" no longer used */
-	/* VM_DIRTY_EXPIRE_CS "dirty_expire_centisecs" no longer used */
-	/* VM_NR_PDFLUSH_THREADS "nr_pdflush_threads" no longer used */
-	{ CTL_INT,	VM_OVERCOMMIT_RATIO,		"overcommit_ratio" },
-	/* VM_PAGEBUF unused */
-	/* VM_HUGETLB_PAGES "nr_hugepages" no longer used */
-	{ CTL_INT,	VM_SWAPPINESS,			"swappiness" },
-	{ CTL_INT,	VM_LOWMEM_RESERVE_RATIO,	"lowmem_reserve_ratio" },
-	{ CTL_INT,	VM_MIN_FREE_KBYTES,		"min_free_kbytes" },
-	{ CTL_INT,	VM_MAX_MAP_COUNT,		"max_map_count" },
-	{ CTL_INT,	VM_LAPTOP_MODE,			"laptop_mode" },
-	{ CTL_INT,	VM_BLOCK_DUMP,			"block_dump" },
-	{ CTL_INT,	VM_HUGETLB_GROUP,		"hugetlb_shm_group" },
-	{ CTL_INT,	VM_VFS_CACHE_PRESSURE,	"vfs_cache_pressure" },
-	{ CTL_INT,	VM_LEGACY_VA_LAYOUT,		"legacy_va_layout" },
-	/* VM_SWAP_TOKEN_TIMEOUT unused */
-	{ CTL_INT,	VM_DROP_PAGECACHE,		"drop_caches" },
-	{ CTL_INT,	VM_PERCPU_PAGELIST_FRACTION,	"percpu_pagelist_fraction" },
-	{ CTL_INT,	VM_ZONE_RECLAIM_MODE,		"zone_reclaim_mode" },
-	{ CTL_INT,	VM_MIN_UNMAPPED,		"min_unmapped_ratio" },
-	{ CTL_INT,	VM_PANIC_ON_OOM,		"panic_on_oom" },
-	{ CTL_INT,	VM_VDSO_ENABLED,		"vdso_enabled" },
-	{ CTL_INT,	VM_MIN_SLAB,			"min_slab_ratio" },
-
-	{}
-};
-
-static const struct bin_table bin_net_core_table[] = {
-	{ CTL_INT,	NET_CORE_WMEM_MAX,	"wmem_max" },
-	{ CTL_INT,	NET_CORE_RMEM_MAX,	"rmem_max" },
-	{ CTL_INT,	NET_CORE_WMEM_DEFAULT,	"wmem_default" },
-	{ CTL_INT,	NET_CORE_RMEM_DEFAULT,	"rmem_default" },
-	/* NET_CORE_DESTROY_DELAY unused */
-	{ CTL_INT,	NET_CORE_MAX_BACKLOG,	"netdev_max_backlog" },
-	/* NET_CORE_FASTROUTE unused */
-	{ CTL_INT,	NET_CORE_MSG_COST,	"message_cost" },
-	{ CTL_INT,	NET_CORE_MSG_BURST,	"message_burst" },
-	{ CTL_INT,	NET_CORE_OPTMEM_MAX,	"optmem_max" },
-	/* NET_CORE_HOT_LIST_LENGTH unused */
-	/* NET_CORE_DIVERT_VERSION unused */
-	/* NET_CORE_NO_CONG_THRESH unused */
-	/* NET_CORE_NO_CONG unused */
-	/* NET_CORE_LO_CONG unused */
-	/* NET_CORE_MOD_CONG unused */
-	{ CTL_INT,	NET_CORE_DEV_WEIGHT,	"dev_weight" },
-	{ CTL_INT,	NET_CORE_SOMAXCONN,	"somaxconn" },
-	{ CTL_INT,	NET_CORE_BUDGET,	"netdev_budget" },
-	{ CTL_INT,	NET_CORE_AEVENT_ETIME,	"xfrm_aevent_etime" },
-	{ CTL_INT,	NET_CORE_AEVENT_RSEQTH,	"xfrm_aevent_rseqth" },
-	{ CTL_INT,	NET_CORE_WARNINGS,	"warnings" },
-	{},
-};
-
-static const struct bin_table bin_net_unix_table[] = {
-	/* NET_UNIX_DESTROY_DELAY unused */
-	/* NET_UNIX_DELETE_DELAY unused */
-	{ CTL_INT,	NET_UNIX_MAX_DGRAM_QLEN,	"max_dgram_qlen" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv4_route_table[] = {
-	{ CTL_INT,	NET_IPV4_ROUTE_FLUSH,			"flush" },
-	/* NET_IPV4_ROUTE_MIN_DELAY "min_delay" no longer used */
-	/* NET_IPV4_ROUTE_MAX_DELAY "max_delay" no longer used */
-	{ CTL_INT,	NET_IPV4_ROUTE_GC_THRESH,		"gc_thresh" },
-	{ CTL_INT,	NET_IPV4_ROUTE_MAX_SIZE,		"max_size" },
-	{ CTL_INT,	NET_IPV4_ROUTE_GC_MIN_INTERVAL,		"gc_min_interval" },
-	{ CTL_INT,	NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,	"gc_min_interval_ms" },
-	{ CTL_INT,	NET_IPV4_ROUTE_GC_TIMEOUT,		"gc_timeout" },
-	/* NET_IPV4_ROUTE_GC_INTERVAL "gc_interval" no longer used */
-	{ CTL_INT,	NET_IPV4_ROUTE_REDIRECT_LOAD,		"redirect_load" },
-	{ CTL_INT,	NET_IPV4_ROUTE_REDIRECT_NUMBER,		"redirect_number" },
-	{ CTL_INT,	NET_IPV4_ROUTE_REDIRECT_SILENCE,	"redirect_silence" },
-	{ CTL_INT,	NET_IPV4_ROUTE_ERROR_COST,		"error_cost" },
-	{ CTL_INT,	NET_IPV4_ROUTE_ERROR_BURST,		"error_burst" },
-	{ CTL_INT,	NET_IPV4_ROUTE_GC_ELASTICITY,		"gc_elasticity" },
-	{ CTL_INT,	NET_IPV4_ROUTE_MTU_EXPIRES,		"mtu_expires" },
-	{ CTL_INT,	NET_IPV4_ROUTE_MIN_PMTU,		"min_pmtu" },
-	{ CTL_INT,	NET_IPV4_ROUTE_MIN_ADVMSS,		"min_adv_mss" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv4_conf_vars_table[] = {
-	{ CTL_INT,	NET_IPV4_CONF_FORWARDING,		"forwarding" },
-	{ CTL_INT,	NET_IPV4_CONF_MC_FORWARDING,		"mc_forwarding" },
-
-	{ CTL_INT,	NET_IPV4_CONF_ACCEPT_REDIRECTS,		"accept_redirects" },
-	{ CTL_INT,	NET_IPV4_CONF_SECURE_REDIRECTS,		"secure_redirects" },
-	{ CTL_INT,	NET_IPV4_CONF_SEND_REDIRECTS,		"send_redirects" },
-	{ CTL_INT,	NET_IPV4_CONF_SHARED_MEDIA,		"shared_media" },
-	{ CTL_INT,	NET_IPV4_CONF_RP_FILTER,		"rp_filter" },
-	{ CTL_INT,	NET_IPV4_CONF_ACCEPT_SOURCE_ROUTE,	"accept_source_route" },
-	{ CTL_INT,	NET_IPV4_CONF_PROXY_ARP,		"proxy_arp" },
-	{ CTL_INT,	NET_IPV4_CONF_MEDIUM_ID,		"medium_id" },
-	{ CTL_INT,	NET_IPV4_CONF_BOOTP_RELAY,		"bootp_relay" },
-	{ CTL_INT,	NET_IPV4_CONF_LOG_MARTIANS,		"log_martians" },
-	{ CTL_INT,	NET_IPV4_CONF_TAG,			"tag" },
-	{ CTL_INT,	NET_IPV4_CONF_ARPFILTER,		"arp_filter" },
-	{ CTL_INT,	NET_IPV4_CONF_ARP_ANNOUNCE,		"arp_announce" },
-	{ CTL_INT,	NET_IPV4_CONF_ARP_IGNORE,		"arp_ignore" },
-	{ CTL_INT,	NET_IPV4_CONF_ARP_ACCEPT,		"arp_accept" },
-	{ CTL_INT,	NET_IPV4_CONF_ARP_NOTIFY,		"arp_notify" },
-
-	{ CTL_INT,	NET_IPV4_CONF_NOXFRM,			"disable_xfrm" },
-	{ CTL_INT,	NET_IPV4_CONF_NOPOLICY,			"disable_policy" },
-	{ CTL_INT,	NET_IPV4_CONF_FORCE_IGMP_VERSION,	"force_igmp_version" },
-	{ CTL_INT,	NET_IPV4_CONF_PROMOTE_SECONDARIES,	"promote_secondaries" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv4_conf_table[] = {
-	{ CTL_DIR,	NET_PROTO_CONF_ALL,	"all",		bin_net_ipv4_conf_vars_table },
-	{ CTL_DIR,	NET_PROTO_CONF_DEFAULT,	"default",	bin_net_ipv4_conf_vars_table },
-	{ CTL_DIR,	0, NULL, bin_net_ipv4_conf_vars_table },
-	{}
-};
-
-static const struct bin_table bin_net_neigh_vars_table[] = {
-	{ CTL_INT,	NET_NEIGH_MCAST_SOLICIT,	"mcast_solicit" },
-	{ CTL_INT,	NET_NEIGH_UCAST_SOLICIT,	"ucast_solicit" },
-	{ CTL_INT,	NET_NEIGH_APP_SOLICIT,		"app_solicit" },
-	/* NET_NEIGH_RETRANS_TIME "retrans_time" no longer used */
-	{ CTL_INT,	NET_NEIGH_REACHABLE_TIME,	"base_reachable_time" },
-	{ CTL_INT,	NET_NEIGH_DELAY_PROBE_TIME,	"delay_first_probe_time" },
-	{ CTL_INT,	NET_NEIGH_GC_STALE_TIME,	"gc_stale_time" },
-	{ CTL_INT,	NET_NEIGH_UNRES_QLEN,		"unres_qlen" },
-	{ CTL_INT,	NET_NEIGH_PROXY_QLEN,		"proxy_qlen" },
-	/* NET_NEIGH_ANYCAST_DELAY "anycast_delay" no longer used */
-	/* NET_NEIGH_PROXY_DELAY "proxy_delay" no longer used */
-	/* NET_NEIGH_LOCKTIME "locktime" no longer used */
-	{ CTL_INT,	NET_NEIGH_GC_INTERVAL,		"gc_interval" },
-	{ CTL_INT,	NET_NEIGH_GC_THRESH1,		"gc_thresh1" },
-	{ CTL_INT,	NET_NEIGH_GC_THRESH2,		"gc_thresh2" },
-	{ CTL_INT,	NET_NEIGH_GC_THRESH3,		"gc_thresh3" },
-	{ CTL_INT,	NET_NEIGH_RETRANS_TIME_MS,	"retrans_time_ms" },
-	{ CTL_INT,	NET_NEIGH_REACHABLE_TIME_MS,	"base_reachable_time_ms" },
-	{}
-};
-
-static const struct bin_table bin_net_neigh_table[] = {
-	{ CTL_DIR,	NET_PROTO_CONF_DEFAULT, "default", bin_net_neigh_vars_table },
-	{ CTL_DIR,	0, NULL, bin_net_neigh_vars_table },
-	{}
-};
-
-static const struct bin_table bin_net_ipv4_netfilter_table[] = {
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_MAX,		"ip_conntrack_max" },
-
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT "ip_conntrack_tcp_timeout_syn_sent" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV "ip_conntrack_tcp_timeout_syn_recv" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED "ip_conntrack_tcp_timeout_established" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_FIN_WAIT "ip_conntrack_tcp_timeout_fin_wait" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE_WAIT	"ip_conntrack_tcp_timeout_close_wait" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_LAST_ACK "ip_conntrack_tcp_timeout_last_ack" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_TIME_WAIT "ip_conntrack_tcp_timeout_time_wait" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE "ip_conntrack_tcp_timeout_close" no longer used */
-
-	/* NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT "ip_conntrack_udp_timeout" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM "ip_conntrack_udp_timeout_stream" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_ICMP_TIMEOUT "ip_conntrack_icmp_timeout" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_GENERIC_TIMEOUT "ip_conntrack_generic_timeout" no longer used */
-
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_BUCKETS,		"ip_conntrack_buckets" },
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_LOG_INVALID,	"ip_conntrack_log_invalid" },
-	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_MAX_RETRANS "ip_conntrack_tcp_timeout_max_retrans" no longer used */
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_TCP_LOOSE,	"ip_conntrack_tcp_loose" },
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL,	"ip_conntrack_tcp_be_liberal" },
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS,	"ip_conntrack_tcp_max_retrans" },
-
-	/* NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_CLOSED "ip_conntrack_sctp_timeout_closed" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_WAIT "ip_conntrack_sctp_timeout_cookie_wait" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_ECHOED "ip_conntrack_sctp_timeout_cookie_echoed" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_ESTABLISHED "ip_conntrack_sctp_timeout_established" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_SENT "ip_conntrack_sctp_timeout_shutdown_sent" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_RECD "ip_conntrack_sctp_timeout_shutdown_recd" no longer used */
-	/* NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_ACK_SENT "ip_conntrack_sctp_timeout_shutdown_ack_sent" no longer used */
-
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_COUNT,		"ip_conntrack_count" },
-	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_CHECKSUM,		"ip_conntrack_checksum" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv4_table[] = {
-	{CTL_INT,	NET_IPV4_FORWARD,			"ip_forward" },
-
-	{ CTL_DIR,	NET_IPV4_CONF,		"conf",		bin_net_ipv4_conf_table },
-	{ CTL_DIR,	NET_IPV4_NEIGH,		"neigh",	bin_net_neigh_table },
-	{ CTL_DIR,	NET_IPV4_ROUTE,		"route",	bin_net_ipv4_route_table },
-	/* NET_IPV4_FIB_HASH unused */
-	{ CTL_DIR,	NET_IPV4_NETFILTER,	"netfilter",	bin_net_ipv4_netfilter_table },
-
-	{ CTL_INT,	NET_IPV4_TCP_TIMESTAMPS,		"tcp_timestamps" },
-	{ CTL_INT,	NET_IPV4_TCP_WINDOW_SCALING,		"tcp_window_scaling" },
-	{ CTL_INT,	NET_IPV4_TCP_SACK,			"tcp_sack" },
-	{ CTL_INT,	NET_IPV4_TCP_RETRANS_COLLAPSE,		"tcp_retrans_collapse" },
-	{ CTL_INT,	NET_IPV4_DEFAULT_TTL,			"ip_default_ttl" },
-	/* NET_IPV4_AUTOCONFIG unused */
-	{ CTL_INT,	NET_IPV4_NO_PMTU_DISC,			"ip_no_pmtu_disc" },
-	{ CTL_INT,	NET_IPV4_NONLOCAL_BIND,			"ip_nonlocal_bind" },
-	{ CTL_INT,	NET_IPV4_TCP_SYN_RETRIES,		"tcp_syn_retries" },
-	{ CTL_INT,	NET_TCP_SYNACK_RETRIES,			"tcp_synack_retries" },
-	{ CTL_INT,	NET_TCP_MAX_ORPHANS,			"tcp_max_orphans" },
-	{ CTL_INT,	NET_TCP_MAX_TW_BUCKETS,			"tcp_max_tw_buckets" },
-	{ CTL_INT,	NET_IPV4_DYNADDR,			"ip_dynaddr" },
-	{ CTL_INT,	NET_IPV4_TCP_KEEPALIVE_TIME,		"tcp_keepalive_time" },
-	{ CTL_INT,	NET_IPV4_TCP_KEEPALIVE_PROBES,		"tcp_keepalive_probes" },
-	{ CTL_INT,	NET_IPV4_TCP_KEEPALIVE_INTVL,		"tcp_keepalive_intvl" },
-	{ CTL_INT,	NET_IPV4_TCP_RETRIES1,			"tcp_retries1" },
-	{ CTL_INT,	NET_IPV4_TCP_RETRIES2,			"tcp_retries2" },
-	{ CTL_INT,	NET_IPV4_TCP_FIN_TIMEOUT,		"tcp_fin_timeout" },
-	{ CTL_INT,	NET_TCP_SYNCOOKIES,			"tcp_syncookies" },
-	{ CTL_INT,	NET_TCP_TW_RECYCLE,			"tcp_tw_recycle" },
-	{ CTL_INT,	NET_TCP_ABORT_ON_OVERFLOW,		"tcp_abort_on_overflow" },
-	{ CTL_INT,	NET_TCP_STDURG,				"tcp_stdurg" },
-	{ CTL_INT,	NET_TCP_RFC1337,			"tcp_rfc1337" },
-	{ CTL_INT,	NET_TCP_MAX_SYN_BACKLOG,		"tcp_max_syn_backlog" },
-	{ CTL_INT,	NET_IPV4_LOCAL_PORT_RANGE,		"ip_local_port_range" },
-	{ CTL_INT,	NET_IPV4_IGMP_MAX_MEMBERSHIPS,		"igmp_max_memberships" },
-	{ CTL_INT,	NET_IPV4_IGMP_MAX_MSF,			"igmp_max_msf" },
-	{ CTL_INT,	NET_IPV4_INET_PEER_THRESHOLD,		"inet_peer_threshold" },
-	{ CTL_INT,	NET_IPV4_INET_PEER_MINTTL,		"inet_peer_minttl" },
-	{ CTL_INT,	NET_IPV4_INET_PEER_MAXTTL,		"inet_peer_maxttl" },
-	{ CTL_INT,	NET_IPV4_INET_PEER_GC_MINTIME,		"inet_peer_gc_mintime" },
-	{ CTL_INT,	NET_IPV4_INET_PEER_GC_MAXTIME,		"inet_peer_gc_maxtime" },
-	{ CTL_INT,	NET_TCP_ORPHAN_RETRIES,			"tcp_orphan_retries" },
-	{ CTL_INT,	NET_TCP_FACK,				"tcp_fack" },
-	{ CTL_INT,	NET_TCP_REORDERING,			"tcp_reordering" },
-	{ CTL_INT,	NET_TCP_ECN,				"tcp_ecn" },
-	{ CTL_INT,	NET_TCP_DSACK,				"tcp_dsack" },
-	{ CTL_INT,	NET_TCP_MEM,				"tcp_mem" },
-	{ CTL_INT,	NET_TCP_WMEM,				"tcp_wmem" },
-	{ CTL_INT,	NET_TCP_RMEM,				"tcp_rmem" },
-	{ CTL_INT,	NET_TCP_APP_WIN,			"tcp_app_win" },
-	{ CTL_INT,	NET_TCP_ADV_WIN_SCALE,			"tcp_adv_win_scale" },
-	{ CTL_INT,	NET_TCP_TW_REUSE,			"tcp_tw_reuse" },
-	{ CTL_INT,	NET_TCP_FRTO,				"tcp_frto" },
-	{ CTL_INT,	NET_TCP_FRTO_RESPONSE,			"tcp_frto_response" },
-	{ CTL_INT,	NET_TCP_LOW_LATENCY,			"tcp_low_latency" },
-	{ CTL_INT,	NET_TCP_NO_METRICS_SAVE,		"tcp_no_metrics_save" },
-	{ CTL_INT,	NET_TCP_MODERATE_RCVBUF,		"tcp_moderate_rcvbuf" },
-	{ CTL_INT,	NET_TCP_TSO_WIN_DIVISOR,		"tcp_tso_win_divisor" },
-	{ CTL_STR,	NET_TCP_CONG_CONTROL,			"tcp_congestion_control" },
-	{ CTL_INT,	NET_TCP_MTU_PROBING,			"tcp_mtu_probing" },
-	{ CTL_INT,	NET_TCP_BASE_MSS,			"tcp_base_mss" },
-	{ CTL_INT,	NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS,	"tcp_workaround_signed_windows" },
-	{ CTL_INT,	NET_TCP_SLOW_START_AFTER_IDLE,		"tcp_slow_start_after_idle" },
-	{ CTL_INT,	NET_CIPSOV4_CACHE_ENABLE,		"cipso_cache_enable" },
-	{ CTL_INT,	NET_CIPSOV4_CACHE_BUCKET_SIZE,		"cipso_cache_bucket_size" },
-	{ CTL_INT,	NET_CIPSOV4_RBM_OPTFMT,			"cipso_rbm_optfmt" },
-	{ CTL_INT,	NET_CIPSOV4_RBM_STRICTVALID,		"cipso_rbm_strictvalid" },
-	/* NET_TCP_AVAIL_CONG_CONTROL "tcp_available_congestion_control" no longer used */
-	{ CTL_STR,	NET_TCP_ALLOWED_CONG_CONTROL,		"tcp_allowed_congestion_control" },
-	{ CTL_INT,	NET_TCP_MAX_SSTHRESH,			"tcp_max_ssthresh" },
-
-	{ CTL_INT,	NET_IPV4_ICMP_ECHO_IGNORE_ALL,		"icmp_echo_ignore_all" },
-	{ CTL_INT,	NET_IPV4_ICMP_ECHO_IGNORE_BROADCASTS,	"icmp_echo_ignore_broadcasts" },
-	{ CTL_INT,	NET_IPV4_ICMP_IGNORE_BOGUS_ERROR_RESPONSES,	"icmp_ignore_bogus_error_responses" },
-	{ CTL_INT,	NET_IPV4_ICMP_ERRORS_USE_INBOUND_IFADDR,	"icmp_errors_use_inbound_ifaddr" },
-	{ CTL_INT,	NET_IPV4_ICMP_RATELIMIT,		"icmp_ratelimit" },
-	{ CTL_INT,	NET_IPV4_ICMP_RATEMASK,			"icmp_ratemask" },
-
-	{ CTL_INT,	NET_IPV4_IPFRAG_HIGH_THRESH,		"ipfrag_high_thresh" },
-	{ CTL_INT,	NET_IPV4_IPFRAG_LOW_THRESH,		"ipfrag_low_thresh" },
-	{ CTL_INT,	NET_IPV4_IPFRAG_TIME,			"ipfrag_time" },
-
-	{ CTL_INT,	NET_IPV4_IPFRAG_SECRET_INTERVAL,	"ipfrag_secret_interval" },
-	/* NET_IPV4_IPFRAG_MAX_DIST "ipfrag_max_dist" no longer used */
-
-	{ CTL_INT,	2088 /* NET_IPQ_QMAX */,		"ip_queue_maxlen" },
-
-	/* NET_TCP_DEFAULT_WIN_SCALE unused */
-	/* NET_TCP_BIC_BETA unused */
-	/* NET_IPV4_TCP_MAX_KA_PROBES unused */
-	/* NET_IPV4_IP_MASQ_DEBUG unused */
-	/* NET_TCP_SYN_TAILDROP unused */
-	/* NET_IPV4_ICMP_SOURCEQUENCH_RATE unused */
-	/* NET_IPV4_ICMP_DESTUNREACH_RATE unused */
-	/* NET_IPV4_ICMP_TIMEEXCEED_RATE unused */
-	/* NET_IPV4_ICMP_PARAMPROB_RATE unused */
-	/* NET_IPV4_ICMP_ECHOREPLY_RATE unused */
-	/* NET_IPV4_ALWAYS_DEFRAG unused */
-	{}
-};
-
-static const struct bin_table bin_net_ipx_table[] = {
-	{ CTL_INT,	NET_IPX_PPROP_BROADCASTING,	"ipx_pprop_broadcasting" },
-	/* NET_IPX_FORWARDING unused */
-	{}
-};
-
-static const struct bin_table bin_net_atalk_table[] = {
-	{ CTL_INT,	NET_ATALK_AARP_EXPIRY_TIME,		"aarp-expiry-time" },
-	{ CTL_INT,	NET_ATALK_AARP_TICK_TIME,		"aarp-tick-time" },
-	{ CTL_INT,	NET_ATALK_AARP_RETRANSMIT_LIMIT,	"aarp-retransmit-limit" },
-	{ CTL_INT,	NET_ATALK_AARP_RESOLVE_TIME,		"aarp-resolve-time" },
-	{},
-};
-
-static const struct bin_table bin_net_netrom_table[] = {
-	{ CTL_INT,	NET_NETROM_DEFAULT_PATH_QUALITY,		"default_path_quality" },
-	{ CTL_INT,	NET_NETROM_OBSOLESCENCE_COUNT_INITIALISER,	"obsolescence_count_initialiser" },
-	{ CTL_INT,	NET_NETROM_NETWORK_TTL_INITIALISER,		"network_ttl_initialiser" },
-	{ CTL_INT,	NET_NETROM_TRANSPORT_TIMEOUT,			"transport_timeout" },
-	{ CTL_INT,	NET_NETROM_TRANSPORT_MAXIMUM_TRIES,		"transport_maximum_tries" },
-	{ CTL_INT,	NET_NETROM_TRANSPORT_ACKNOWLEDGE_DELAY,		"transport_acknowledge_delay" },
-	{ CTL_INT,	NET_NETROM_TRANSPORT_BUSY_DELAY,		"transport_busy_delay" },
-	{ CTL_INT,	NET_NETROM_TRANSPORT_REQUESTED_WINDOW_SIZE,	"transport_requested_window_size" },
-	{ CTL_INT,	NET_NETROM_TRANSPORT_NO_ACTIVITY_TIMEOUT,	"transport_no_activity_timeout" },
-	{ CTL_INT,	NET_NETROM_ROUTING_CONTROL,			"routing_control" },
-	{ CTL_INT,	NET_NETROM_LINK_FAILS_COUNT,			"link_fails_count" },
-	{ CTL_INT,	NET_NETROM_RESET,				"reset" },
-	{}
-};
-
-static const struct bin_table bin_net_ax25_param_table[] = {
-	{ CTL_INT,	NET_AX25_IP_DEFAULT_MODE,	"ip_default_mode" },
-	{ CTL_INT,	NET_AX25_DEFAULT_MODE,		"ax25_default_mode" },
-	{ CTL_INT,	NET_AX25_BACKOFF_TYPE,		"backoff_type" },
-	{ CTL_INT,	NET_AX25_CONNECT_MODE,		"connect_mode" },
-	{ CTL_INT,	NET_AX25_STANDARD_WINDOW,	"standard_window_size" },
-	{ CTL_INT,	NET_AX25_EXTENDED_WINDOW,	"extended_window_size" },
-	{ CTL_INT,	NET_AX25_T1_TIMEOUT,		"t1_timeout" },
-	{ CTL_INT,	NET_AX25_T2_TIMEOUT,		"t2_timeout" },
-	{ CTL_INT,	NET_AX25_T3_TIMEOUT,		"t3_timeout" },
-	{ CTL_INT,	NET_AX25_IDLE_TIMEOUT,		"idle_timeout" },
-	{ CTL_INT,	NET_AX25_N2,			"maximum_retry_count" },
-	{ CTL_INT,	NET_AX25_PACLEN,		"maximum_packet_length" },
-	{ CTL_INT,	NET_AX25_PROTOCOL,		"protocol" },
-	{ CTL_INT,	NET_AX25_DAMA_SLAVE_TIMEOUT,	"dama_slave_timeout" },
-	{}
-};
-
-static const struct bin_table bin_net_ax25_table[] = {
-	{ CTL_DIR,	0, NULL, bin_net_ax25_param_table },
-	{}
-};
-
-static const struct bin_table bin_net_rose_table[] = {
-	{ CTL_INT,	NET_ROSE_RESTART_REQUEST_TIMEOUT,	"restart_request_timeout" },
-	{ CTL_INT,	NET_ROSE_CALL_REQUEST_TIMEOUT,		"call_request_timeout" },
-	{ CTL_INT,	NET_ROSE_RESET_REQUEST_TIMEOUT,		"reset_request_timeout" },
-	{ CTL_INT,	NET_ROSE_CLEAR_REQUEST_TIMEOUT,		"clear_request_timeout" },
-	{ CTL_INT,	NET_ROSE_ACK_HOLD_BACK_TIMEOUT,		"acknowledge_hold_back_timeout" },
-	{ CTL_INT,	NET_ROSE_ROUTING_CONTROL,		"routing_control" },
-	{ CTL_INT,	NET_ROSE_LINK_FAIL_TIMEOUT,		"link_fail_timeout" },
-	{ CTL_INT,	NET_ROSE_MAX_VCS,			"maximum_virtual_circuits" },
-	{ CTL_INT,	NET_ROSE_WINDOW_SIZE,			"window_size" },
-	{ CTL_INT,	NET_ROSE_NO_ACTIVITY_TIMEOUT,		"no_activity_timeout" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv6_conf_var_table[] = {
-	{ CTL_INT,	NET_IPV6_FORWARDING,			"forwarding" },
-	{ CTL_INT,	NET_IPV6_HOP_LIMIT,			"hop_limit" },
-	{ CTL_INT,	NET_IPV6_MTU,				"mtu" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_RA,			"accept_ra" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_REDIRECTS,		"accept_redirects" },
-	{ CTL_INT,	NET_IPV6_AUTOCONF,			"autoconf" },
-	{ CTL_INT,	NET_IPV6_DAD_TRANSMITS,			"dad_transmits" },
-	{ CTL_INT,	NET_IPV6_RTR_SOLICITS,			"router_solicitations" },
-	{ CTL_INT,	NET_IPV6_RTR_SOLICIT_INTERVAL,		"router_solicitation_interval" },
-	{ CTL_INT,	NET_IPV6_RTR_SOLICIT_DELAY,		"router_solicitation_delay" },
-	{ CTL_INT,	NET_IPV6_USE_TEMPADDR,			"use_tempaddr" },
-	{ CTL_INT,	NET_IPV6_TEMP_VALID_LFT,		"temp_valid_lft" },
-	{ CTL_INT,	NET_IPV6_TEMP_PREFERED_LFT,		"temp_prefered_lft" },
-	{ CTL_INT,	NET_IPV6_REGEN_MAX_RETRY,		"regen_max_retry" },
-	{ CTL_INT,	NET_IPV6_MAX_DESYNC_FACTOR,		"max_desync_factor" },
-	{ CTL_INT,	NET_IPV6_MAX_ADDRESSES,			"max_addresses" },
-	{ CTL_INT,	NET_IPV6_FORCE_MLD_VERSION,		"force_mld_version" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_RA_DEFRTR,		"accept_ra_defrtr" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_RA_PINFO,		"accept_ra_pinfo" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_RA_RTR_PREF,		"accept_ra_rtr_pref" },
-	{ CTL_INT,	NET_IPV6_RTR_PROBE_INTERVAL,		"router_probe_interval" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_RA_RT_INFO_MAX_PLEN,	"accept_ra_rt_info_max_plen" },
-	{ CTL_INT,	NET_IPV6_PROXY_NDP,			"proxy_ndp" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_SOURCE_ROUTE,		"accept_source_route" },
-	{ CTL_INT,	NET_IPV6_ACCEPT_RA_FROM_LOCAL,		"accept_ra_from_local" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv6_conf_table[] = {
-	{ CTL_DIR,	NET_PROTO_CONF_ALL,		"all",	bin_net_ipv6_conf_var_table },
-	{ CTL_DIR,	NET_PROTO_CONF_DEFAULT, 	"default", bin_net_ipv6_conf_var_table },
-	{ CTL_DIR,	0, NULL, bin_net_ipv6_conf_var_table },
-	{}
-};
-
-static const struct bin_table bin_net_ipv6_route_table[] = {
-	/* NET_IPV6_ROUTE_FLUSH	"flush"  no longer used */
-	{ CTL_INT,	NET_IPV6_ROUTE_GC_THRESH,		"gc_thresh" },
-	{ CTL_INT,	NET_IPV6_ROUTE_MAX_SIZE,		"max_size" },
-	{ CTL_INT,	NET_IPV6_ROUTE_GC_MIN_INTERVAL,		"gc_min_interval" },
-	{ CTL_INT,	NET_IPV6_ROUTE_GC_TIMEOUT,		"gc_timeout" },
-	{ CTL_INT,	NET_IPV6_ROUTE_GC_INTERVAL,		"gc_interval" },
-	{ CTL_INT,	NET_IPV6_ROUTE_GC_ELASTICITY,		"gc_elasticity" },
-	{ CTL_INT,	NET_IPV6_ROUTE_MTU_EXPIRES,		"mtu_expires" },
-	{ CTL_INT,	NET_IPV6_ROUTE_MIN_ADVMSS,		"min_adv_mss" },
-	{ CTL_INT,	NET_IPV6_ROUTE_GC_MIN_INTERVAL_MS,	"gc_min_interval_ms" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv6_icmp_table[] = {
-	{ CTL_INT,	NET_IPV6_ICMP_RATELIMIT,	"ratelimit" },
-	{}
-};
-
-static const struct bin_table bin_net_ipv6_table[] = {
-	{ CTL_DIR,	NET_IPV6_CONF,		"conf",		bin_net_ipv6_conf_table },
-	{ CTL_DIR,	NET_IPV6_NEIGH,		"neigh",	bin_net_neigh_table },
-	{ CTL_DIR,	NET_IPV6_ROUTE,		"route",	bin_net_ipv6_route_table },
-	{ CTL_DIR,	NET_IPV6_ICMP,		"icmp",		bin_net_ipv6_icmp_table },
-	{ CTL_INT,	NET_IPV6_BINDV6ONLY,		"bindv6only" },
-	{ CTL_INT,	NET_IPV6_IP6FRAG_HIGH_THRESH,	"ip6frag_high_thresh" },
-	{ CTL_INT,	NET_IPV6_IP6FRAG_LOW_THRESH,	"ip6frag_low_thresh" },
-	{ CTL_INT,	NET_IPV6_IP6FRAG_TIME,		"ip6frag_time" },
-	{ CTL_INT,	NET_IPV6_IP6FRAG_SECRET_INTERVAL,	"ip6frag_secret_interval" },
-	{ CTL_INT,	NET_IPV6_MLD_MAX_MSF,		"mld_max_msf" },
-	{ CTL_INT,	2088 /* IPQ_QMAX */,		"ip6_queue_maxlen" },
-	{}
-};
-
-static const struct bin_table bin_net_x25_table[] = {
-	{ CTL_INT,	NET_X25_RESTART_REQUEST_TIMEOUT,	"restart_request_timeout" },
-	{ CTL_INT,	NET_X25_CALL_REQUEST_TIMEOUT,		"call_request_timeout" },
-	{ CTL_INT,	NET_X25_RESET_REQUEST_TIMEOUT,	"reset_request_timeout" },
-	{ CTL_INT,	NET_X25_CLEAR_REQUEST_TIMEOUT,	"clear_request_timeout" },
-	{ CTL_INT,	NET_X25_ACK_HOLD_BACK_TIMEOUT,	"acknowledgement_hold_back_timeout" },
-	{ CTL_INT,	NET_X25_FORWARD,			"x25_forward" },
-	{}
-};
-
-static const struct bin_table bin_net_tr_table[] = {
-	{ CTL_INT,	NET_TR_RIF_TIMEOUT,	"rif_timeout" },
-	{}
-};
-
-
-static const struct bin_table bin_net_decnet_conf_vars[] = {
-	{ CTL_INT,	NET_DECNET_CONF_DEV_FORWARDING,	"forwarding" },
-	{ CTL_INT,	NET_DECNET_CONF_DEV_PRIORITY,	"priority" },
-	{ CTL_INT,	NET_DECNET_CONF_DEV_T2,		"t2" },
-	{ CTL_INT,	NET_DECNET_CONF_DEV_T3,		"t3" },
-	{}
-};
-
-static const struct bin_table bin_net_decnet_conf[] = {
-	{ CTL_DIR, NET_DECNET_CONF_ETHER,    "ethernet", bin_net_decnet_conf_vars },
-	{ CTL_DIR, NET_DECNET_CONF_GRE,	     "ipgre",    bin_net_decnet_conf_vars },
-	{ CTL_DIR, NET_DECNET_CONF_X25,	     "x25",      bin_net_decnet_conf_vars },
-	{ CTL_DIR, NET_DECNET_CONF_PPP,	     "ppp",      bin_net_decnet_conf_vars },
-	{ CTL_DIR, NET_DECNET_CONF_DDCMP,    "ddcmp",    bin_net_decnet_conf_vars },
-	{ CTL_DIR, NET_DECNET_CONF_LOOPBACK, "loopback", bin_net_decnet_conf_vars },
-	{ CTL_DIR, 0,			     NULL,	 bin_net_decnet_conf_vars },
-	{}
-};
-
-static const struct bin_table bin_net_decnet_table[] = {
-	{ CTL_DIR,	NET_DECNET_CONF,		"conf",	bin_net_decnet_conf },
-	{ CTL_DNADR,	NET_DECNET_NODE_ADDRESS,	"node_address" },
-	{ CTL_STR,	NET_DECNET_NODE_NAME,		"node_name" },
-	{ CTL_STR,	NET_DECNET_DEFAULT_DEVICE,	"default_device" },
-	{ CTL_INT,	NET_DECNET_TIME_WAIT,		"time_wait" },
-	{ CTL_INT,	NET_DECNET_DN_COUNT,		"dn_count" },
-	{ CTL_INT,	NET_DECNET_DI_COUNT,		"di_count" },
-	{ CTL_INT,	NET_DECNET_DR_COUNT,		"dr_count" },
-	{ CTL_INT,	NET_DECNET_DST_GC_INTERVAL,	"dst_gc_interval" },
-	{ CTL_INT,	NET_DECNET_NO_FC_MAX_CWND,	"no_fc_max_cwnd" },
-	{ CTL_INT,	NET_DECNET_MEM,		"decnet_mem" },
-	{ CTL_INT,	NET_DECNET_RMEM,		"decnet_rmem" },
-	{ CTL_INT,	NET_DECNET_WMEM,		"decnet_wmem" },
-	{ CTL_INT,	NET_DECNET_DEBUG_LEVEL,	"debug" },
-	{}
-};
-
-static const struct bin_table bin_net_sctp_table[] = {
-	{ CTL_INT,	NET_SCTP_RTO_INITIAL,		"rto_initial" },
-	{ CTL_INT,	NET_SCTP_RTO_MIN,		"rto_min" },
-	{ CTL_INT,	NET_SCTP_RTO_MAX,		"rto_max" },
-	{ CTL_INT,	NET_SCTP_RTO_ALPHA,		"rto_alpha_exp_divisor" },
-	{ CTL_INT,	NET_SCTP_RTO_BETA,		"rto_beta_exp_divisor" },
-	{ CTL_INT,	NET_SCTP_VALID_COOKIE_LIFE,	"valid_cookie_life" },
-	{ CTL_INT,	NET_SCTP_ASSOCIATION_MAX_RETRANS,	"association_max_retrans" },
-	{ CTL_INT,	NET_SCTP_PATH_MAX_RETRANS,	"path_max_retrans" },
-	{ CTL_INT,	NET_SCTP_MAX_INIT_RETRANSMITS,	"max_init_retransmits" },
-	{ CTL_INT,	NET_SCTP_HB_INTERVAL,		"hb_interval" },
-	{ CTL_INT,	NET_SCTP_PRESERVE_ENABLE,	"cookie_preserve_enable" },
-	{ CTL_INT,	NET_SCTP_MAX_BURST,		"max_burst" },
-	{ CTL_INT,	NET_SCTP_ADDIP_ENABLE,		"addip_enable" },
-	{ CTL_INT,	NET_SCTP_PRSCTP_ENABLE,		"prsctp_enable" },
-	{ CTL_INT,	NET_SCTP_SNDBUF_POLICY,		"sndbuf_policy" },
-	{ CTL_INT,	NET_SCTP_SACK_TIMEOUT,		"sack_timeout" },
-	{ CTL_INT,	NET_SCTP_RCVBUF_POLICY,		"rcvbuf_policy" },
-	{}
-};
-
-static const struct bin_table bin_net_llc_llc2_timeout_table[] = {
-	{ CTL_INT,	NET_LLC2_ACK_TIMEOUT,	"ack" },
-	{ CTL_INT,	NET_LLC2_P_TIMEOUT,	"p" },
-	{ CTL_INT,	NET_LLC2_REJ_TIMEOUT,	"rej" },
-	{ CTL_INT,	NET_LLC2_BUSY_TIMEOUT,	"busy" },
-	{}
-};
-
-static const struct bin_table bin_net_llc_station_table[] = {
-	{ CTL_INT,	NET_LLC_STATION_ACK_TIMEOUT,	"ack_timeout" },
-	{}
-};
-
-static const struct bin_table bin_net_llc_llc2_table[] = {
-	{ CTL_DIR,	NET_LLC2,		"timeout",	bin_net_llc_llc2_timeout_table },
-	{}
-};
-
-static const struct bin_table bin_net_llc_table[] = {
-	{ CTL_DIR,	NET_LLC2,		"llc2",		bin_net_llc_llc2_table },
-	{ CTL_DIR,	NET_LLC_STATION,	"station",	bin_net_llc_station_table },
-	{}
-};
-
-static const struct bin_table bin_net_netfilter_table[] = {
-	{ CTL_INT,	NET_NF_CONNTRACK_MAX,			"nf_conntrack_max" },
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT "nf_conntrack_tcp_timeout_syn_sent" no longer used */
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV "nf_conntrack_tcp_timeout_syn_recv" no longer used */
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED "nf_conntrack_tcp_timeout_established" no longer used */
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_FIN_WAIT "nf_conntrack_tcp_timeout_fin_wait" no longer used */
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_CLOSE_WAIT "nf_conntrack_tcp_timeout_close_wait" no longer used */
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_LAST_ACK "nf_conntrack_tcp_timeout_last_ack" no longer used */
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_TIME_WAIT "nf_conntrack_tcp_timeout_time_wait" no longer used */
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_CLOSE "nf_conntrack_tcp_timeout_close" no longer used */
-	/* NET_NF_CONNTRACK_UDP_TIMEOUT	"nf_conntrack_udp_timeout" no longer used */
-	/* NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM "nf_conntrack_udp_timeout_stream" no longer used */
-	/* NET_NF_CONNTRACK_ICMP_TIMEOUT "nf_conntrack_icmp_timeout" no longer used */
-	/* NET_NF_CONNTRACK_GENERIC_TIMEOUT "nf_conntrack_generic_timeout" no longer used */
-	{ CTL_INT,	NET_NF_CONNTRACK_BUCKETS,		"nf_conntrack_buckets" },
-	{ CTL_INT,	NET_NF_CONNTRACK_LOG_INVALID,		"nf_conntrack_log_invalid" },
-	/* NET_NF_CONNTRACK_TCP_TIMEOUT_MAX_RETRANS "nf_conntrack_tcp_timeout_max_retrans" no longer used */
-	{ CTL_INT,	NET_NF_CONNTRACK_TCP_LOOSE,		"nf_conntrack_tcp_loose" },
-	{ CTL_INT,	NET_NF_CONNTRACK_TCP_BE_LIBERAL,	"nf_conntrack_tcp_be_liberal" },
-	{ CTL_INT,	NET_NF_CONNTRACK_TCP_MAX_RETRANS,	"nf_conntrack_tcp_max_retrans" },
-	/* NET_NF_CONNTRACK_SCTP_TIMEOUT_CLOSED "nf_conntrack_sctp_timeout_closed" no longer used */
-	/* NET_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_WAIT "nf_conntrack_sctp_timeout_cookie_wait" no longer used */
-	/* NET_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_ECHOED "nf_conntrack_sctp_timeout_cookie_echoed" no longer used */
-	/* NET_NF_CONNTRACK_SCTP_TIMEOUT_ESTABLISHED "nf_conntrack_sctp_timeout_established" no longer used */
-	/* NET_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_SENT "nf_conntrack_sctp_timeout_shutdown_sent" no longer used */
-	/* NET_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_RECD "nf_conntrack_sctp_timeout_shutdown_recd" no longer used */
-	/* NET_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_ACK_SENT "nf_conntrack_sctp_timeout_shutdown_ack_sent" no longer used */
-	{ CTL_INT,	NET_NF_CONNTRACK_COUNT,			"nf_conntrack_count" },
-	/* NET_NF_CONNTRACK_ICMPV6_TIMEOUT "nf_conntrack_icmpv6_timeout" no longer used */
-	/* NET_NF_CONNTRACK_FRAG6_TIMEOUT "nf_conntrack_frag6_timeout" no longer used */
-	{ CTL_INT,	NET_NF_CONNTRACK_FRAG6_LOW_THRESH,	"nf_conntrack_frag6_low_thresh" },
-	{ CTL_INT,	NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,	"nf_conntrack_frag6_high_thresh" },
-	{ CTL_INT,	NET_NF_CONNTRACK_CHECKSUM,		"nf_conntrack_checksum" },
-
-	{}
-};
-
-static const struct bin_table bin_net_table[] = {
-	{ CTL_DIR,	NET_CORE,		"core",		bin_net_core_table },
-	/* NET_ETHER not used */
-	/* NET_802 not used */
-	{ CTL_DIR,	NET_UNIX,		"unix",		bin_net_unix_table },
-	{ CTL_DIR,	NET_IPV4,		"ipv4",		bin_net_ipv4_table },
-	{ CTL_DIR,	NET_IPX,		"ipx",		bin_net_ipx_table },
-	{ CTL_DIR,	NET_ATALK,		"appletalk",	bin_net_atalk_table },
-	{ CTL_DIR,	NET_NETROM,		"netrom",	bin_net_netrom_table },
-	{ CTL_DIR,	NET_AX25,		"ax25",		bin_net_ax25_table },
-	/*  NET_BRIDGE "bridge" no longer used */
-	{ CTL_DIR,	NET_ROSE,		"rose",		bin_net_rose_table },
-	{ CTL_DIR,	NET_IPV6,		"ipv6",		bin_net_ipv6_table },
-	{ CTL_DIR,	NET_X25,		"x25",		bin_net_x25_table },
-	{ CTL_DIR,	NET_TR,			"token-ring",	bin_net_tr_table },
-	{ CTL_DIR,	NET_DECNET,		"decnet",	bin_net_decnet_table },
-	/*  NET_ECONET not used */
-	{ CTL_DIR,	NET_SCTP,		"sctp",		bin_net_sctp_table },
-	{ CTL_DIR,	NET_LLC,		"llc",		bin_net_llc_table },
-	{ CTL_DIR,	NET_NETFILTER,		"netfilter",	bin_net_netfilter_table },
-	/* NET_DCCP "dccp" no longer used */
-	/* NET_IRDA "irda" no longer used */
-	{ CTL_INT,	2089,			"nf_conntrack_max" },
-	{}
-};
-
-static const struct bin_table bin_fs_quota_table[] = {
-	{ CTL_INT,	FS_DQ_LOOKUPS,		"lookups" },
-	{ CTL_INT,	FS_DQ_DROPS,		"drops" },
-	{ CTL_INT,	FS_DQ_READS,		"reads" },
-	{ CTL_INT,	FS_DQ_WRITES,		"writes" },
-	{ CTL_INT,	FS_DQ_CACHE_HITS,	"cache_hits" },
-	{ CTL_INT,	FS_DQ_ALLOCATED,	"allocated_dquots" },
-	{ CTL_INT,	FS_DQ_FREE,		"free_dquots" },
-	{ CTL_INT,	FS_DQ_SYNCS,		"syncs" },
-	{ CTL_INT,	FS_DQ_WARNINGS,		"warnings" },
-	{}
-};
-
-static const struct bin_table bin_fs_xfs_table[] = {
-	{ CTL_INT,	XFS_SGID_INHERIT,	"irix_sgid_inherit" },
-	{ CTL_INT,	XFS_SYMLINK_MODE,	"irix_symlink_mode" },
-	{ CTL_INT,	XFS_PANIC_MASK,		"panic_mask" },
-
-	{ CTL_INT,	XFS_ERRLEVEL,		"error_level" },
-	{ CTL_INT,	XFS_SYNCD_TIMER,	"xfssyncd_centisecs" },
-	{ CTL_INT,	XFS_INHERIT_SYNC,	"inherit_sync" },
-	{ CTL_INT,	XFS_INHERIT_NODUMP,	"inherit_nodump" },
-	{ CTL_INT,	XFS_INHERIT_NOATIME,	"inherit_noatime" },
-	{ CTL_INT,	XFS_BUF_TIMER,		"xfsbufd_centisecs" },
-	{ CTL_INT,	XFS_BUF_AGE,		"age_buffer_centisecs" },
-	{ CTL_INT,	XFS_INHERIT_NOSYM,	"inherit_nosymlinks" },
-	{ CTL_INT,	XFS_ROTORSTEP,	"rotorstep" },
-	{ CTL_INT,	XFS_INHERIT_NODFRG,	"inherit_nodefrag" },
-	{ CTL_INT,	XFS_FILESTREAM_TIMER,	"filestream_centisecs" },
-	{ CTL_INT,	XFS_STATS_CLEAR,	"stats_clear" },
-	{}
-};
-
-static const struct bin_table bin_fs_ocfs2_nm_table[] = {
-	{ CTL_STR,	1, "hb_ctl_path" },
-	{}
-};
-
-static const struct bin_table bin_fs_ocfs2_table[] = {
-	{ CTL_DIR,	1,	"nm",	bin_fs_ocfs2_nm_table },
-	{}
-};
-
-static const struct bin_table bin_inotify_table[] = {
-	{ CTL_INT,	INOTIFY_MAX_USER_INSTANCES,	"max_user_instances" },
-	{ CTL_INT,	INOTIFY_MAX_USER_WATCHES,	"max_user_watches" },
-	{ CTL_INT,	INOTIFY_MAX_QUEUED_EVENTS,	"max_queued_events" },
-	{}
-};
-
-static const struct bin_table bin_fs_table[] = {
-	{ CTL_INT,	FS_NRINODE,		"inode-nr" },
-	{ CTL_INT,	FS_STATINODE,		"inode-state" },
-	/* FS_MAXINODE unused */
-	/* FS_NRDQUOT unused */
-	/* FS_MAXDQUOT unused */
-	/* FS_NRFILE "file-nr" no longer used */
-	{ CTL_INT,	FS_MAXFILE,		"file-max" },
-	{ CTL_INT,	FS_DENTRY,		"dentry-state" },
-	/* FS_NRSUPER unused */
-	/* FS_MAXUPSER unused */
-	{ CTL_INT,	FS_OVERFLOWUID,		"overflowuid" },
-	{ CTL_INT,	FS_OVERFLOWGID,		"overflowgid" },
-	{ CTL_INT,	FS_LEASES,		"leases-enable" },
-	{ CTL_INT,	FS_DIR_NOTIFY,		"dir-notify-enable" },
-	{ CTL_INT,	FS_LEASE_TIME,		"lease-break-time" },
-	{ CTL_DIR,	FS_DQSTATS,		"quota",	bin_fs_quota_table },
-	{ CTL_DIR,	FS_XFS,			"xfs",		bin_fs_xfs_table },
-	{ CTL_ULONG,	FS_AIO_NR,		"aio-nr" },
-	{ CTL_ULONG,	FS_AIO_MAX_NR,		"aio-max-nr" },
-	{ CTL_DIR,	FS_INOTIFY,		"inotify",	bin_inotify_table },
-	{ CTL_DIR,	FS_OCFS2,		"ocfs2",	bin_fs_ocfs2_table },
-	{ CTL_INT,	KERN_SETUID_DUMPABLE,	"suid_dumpable" },
-	{}
-};
-
-static const struct bin_table bin_ipmi_table[] = {
-	{ CTL_INT,	DEV_IPMI_POWEROFF_POWERCYCLE,	"poweroff_powercycle" },
-	{}
-};
-
-static const struct bin_table bin_mac_hid_files[] = {
-	/* DEV_MAC_HID_KEYBOARD_SENDS_LINUX_KEYCODES unused */
-	/* DEV_MAC_HID_KEYBOARD_LOCK_KEYCODES unused */
-	{ CTL_INT,	DEV_MAC_HID_MOUSE_BUTTON_EMULATION,	"mouse_button_emulation" },
-	{ CTL_INT,	DEV_MAC_HID_MOUSE_BUTTON2_KEYCODE,	"mouse_button2_keycode" },
-	{ CTL_INT,	DEV_MAC_HID_MOUSE_BUTTON3_KEYCODE,	"mouse_button3_keycode" },
-	/* DEV_MAC_HID_ADB_MOUSE_SENDS_KEYCODES unused */
-	{}
-};
-
-static const struct bin_table bin_raid_table[] = {
-	{ CTL_INT,	DEV_RAID_SPEED_LIMIT_MIN,	"speed_limit_min" },
-	{ CTL_INT,	DEV_RAID_SPEED_LIMIT_MAX,	"speed_limit_max" },
-	{}
-};
-
-static const struct bin_table bin_scsi_table[] = {
-	{ CTL_INT, DEV_SCSI_LOGGING_LEVEL, "logging_level" },
-	{}
-};
-
-static const struct bin_table bin_dev_table[] = {
-	/* DEV_CDROM	"cdrom" no longer used */
-	/* DEV_HWMON unused */
-	/* DEV_PARPORT	"parport" no longer used */
-	{ CTL_DIR,	DEV_RAID,	"raid",		bin_raid_table },
-	{ CTL_DIR,	DEV_MAC_HID,	"mac_hid",	bin_mac_hid_files },
-	{ CTL_DIR,	DEV_SCSI,	"scsi",		bin_scsi_table },
-	{ CTL_DIR,	DEV_IPMI,	"ipmi",		bin_ipmi_table },
-	{}
-};
-
-static const struct bin_table bin_bus_isa_table[] = {
-	{ CTL_INT,	BUS_ISA_MEM_BASE,	"membase" },
-	{ CTL_INT,	BUS_ISA_PORT_BASE,	"portbase" },
-	{ CTL_INT,	BUS_ISA_PORT_SHIFT,	"portshift" },
-	{}
-};
-
-static const struct bin_table bin_bus_table[] = {
-	{ CTL_DIR,	CTL_BUS_ISA,	"isa",	bin_bus_isa_table },
-	{}
-};
-
-
-static const struct bin_table bin_s390dbf_table[] = {
-	{ CTL_INT,	5678 /* CTL_S390DBF_STOPPABLE */, "debug_stoppable" },
-	{ CTL_INT,	5679 /* CTL_S390DBF_ACTIVE */,	  "debug_active" },
-	{}
-};
-
-static const struct bin_table bin_sunrpc_table[] = {
-	/* CTL_RPCDEBUG	"rpc_debug"  no longer used */
-	/* CTL_NFSDEBUG "nfs_debug"  no longer used */
-	/* CTL_NFSDDEBUG "nfsd_debug" no longer used  */
-	/* CTL_NLMDEBUG "nlm_debug" no longer used */
-
-	{ CTL_INT,	CTL_SLOTTABLE_UDP,	"udp_slot_table_entries" },
-	{ CTL_INT,	CTL_SLOTTABLE_TCP,	"tcp_slot_table_entries" },
-	{ CTL_INT,	CTL_MIN_RESVPORT,	"min_resvport" },
-	{ CTL_INT,	CTL_MAX_RESVPORT,	"max_resvport" },
-	{}
-};
-
-static const struct bin_table bin_pm_table[] = {
-	/* frv specific */
-	/* 1 == CTL_PM_SUSPEND	"suspend"  no longer used" */
-	{ CTL_INT,	2 /* CTL_PM_CMODE */,		"cmode" },
-	{ CTL_INT,	3 /* CTL_PM_P0 */,		"p0" },
-	{ CTL_INT,	4 /* CTL_PM_CM */,		"cm" },
-	{}
-};
-
-static const struct bin_table bin_root_table[] = {
-	{ CTL_DIR,	CTL_KERN,	"kernel",	bin_kern_table },
-	{ CTL_DIR,	CTL_VM,		"vm",		bin_vm_table },
-	{ CTL_DIR,	CTL_NET,	"net",		bin_net_table },
-	/* CTL_PROC not used */
-	{ CTL_DIR,	CTL_FS,		"fs",		bin_fs_table },
-	/* CTL_DEBUG "debug" no longer used */
-	{ CTL_DIR,	CTL_DEV,	"dev",		bin_dev_table },
-	{ CTL_DIR,	CTL_BUS,	"bus",		bin_bus_table },
-	{ CTL_DIR,	CTL_ABI,	"abi" },
-	/* CTL_CPU not used */
-	/* CTL_ARLAN "arlan" no longer used */
-	{ CTL_DIR,	CTL_S390DBF,	"s390dbf",	bin_s390dbf_table },
-	{ CTL_DIR,	CTL_SUNRPC,	"sunrpc",	bin_sunrpc_table },
-	{ CTL_DIR,	CTL_PM,		"pm",		bin_pm_table },
-	{}
-};
-
-static ssize_t bin_dir(struct file *file,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	return -ENOTDIR;
-}
-
-
-static ssize_t bin_string(struct file *file,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	ssize_t result, copied = 0;
-
-	if (oldval && oldlen) {
-		char __user *lastp;
-		loff_t pos = 0;
-		int ch;
-
-		result = vfs_read(file, oldval, oldlen, &pos);
-		if (result < 0)
-			goto out;
-
-		copied = result;
-		lastp = oldval + copied - 1;
-
-		result = -EFAULT;
-		if (get_user(ch, lastp))
-			goto out;
-
-		/* Trim off the trailing newline */
-		if (ch == '\n') {
-			result = -EFAULT;
-			if (put_user('\0', lastp))
-				goto out;
-			copied -= 1;
-		}
-	}
-
-	if (newval && newlen) {
-		loff_t pos = 0;
-
-		result = vfs_write(file, newval, newlen, &pos);
-		if (result < 0)
-			goto out;
-	}
-
-	result = copied;
-out:
-	return result;
-}
-
-static ssize_t bin_intvec(struct file *file,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	ssize_t copied = 0;
-	char *buffer;
-	ssize_t result;
-
-	result = -ENOMEM;
-	buffer = kmalloc(BUFSZ, GFP_KERNEL);
-	if (!buffer)
-		goto out;
-
-	if (oldval && oldlen) {
-		unsigned __user *vec = oldval;
-		size_t length = oldlen / sizeof(*vec);
-		char *str, *end;
-		int i;
-		loff_t pos = 0;
-
-		result = kernel_read(file, buffer, BUFSZ - 1, &pos);
-		if (result < 0)
-			goto out_kfree;
-
-		str = buffer;
-		end = str + result;
-		*end++ = '\0';
-		for (i = 0; i < length; i++) {
-			unsigned long value;
-
-			value = simple_strtoul(str, &str, 10);
-			while (isspace(*str))
-				str++;
-			
-			result = -EFAULT;
-			if (put_user(value, vec + i))
-				goto out_kfree;
-
-			copied += sizeof(*vec);
-			if (!isdigit(*str))
-				break;
-		}
-	}
-
-	if (newval && newlen) {
-		unsigned __user *vec = newval;
-		size_t length = newlen / sizeof(*vec);
-		char *str, *end;
-		int i;
-		loff_t pos = 0;
-
-		str = buffer;
-		end = str + BUFSZ;
-		for (i = 0; i < length; i++) {
-			unsigned long value;
-
-			result = -EFAULT;
-			if (get_user(value, vec + i))
-				goto out_kfree;
-
-			str += scnprintf(str, end - str, "%lu\t", value);
-		}
-
-		result = kernel_write(file, buffer, str - buffer, &pos);
-		if (result < 0)
-			goto out_kfree;
-	}
-	result = copied;
-out_kfree:
-	kfree(buffer);
-out:
-	return result;
-}
-
-static ssize_t bin_ulongvec(struct file *file,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	ssize_t copied = 0;
-	char *buffer;
-	ssize_t result;
-
-	result = -ENOMEM;
-	buffer = kmalloc(BUFSZ, GFP_KERNEL);
-	if (!buffer)
-		goto out;
-
-	if (oldval && oldlen) {
-		unsigned long __user *vec = oldval;
-		size_t length = oldlen / sizeof(*vec);
-		char *str, *end;
-		int i;
-		loff_t pos = 0;
-
-		result = kernel_read(file, buffer, BUFSZ - 1, &pos);
-		if (result < 0)
-			goto out_kfree;
-
-		str = buffer;
-		end = str + result;
-		*end++ = '\0';
-		for (i = 0; i < length; i++) {
-			unsigned long value;
-
-			value = simple_strtoul(str, &str, 10);
-			while (isspace(*str))
-				str++;
-			
-			result = -EFAULT;
-			if (put_user(value, vec + i))
-				goto out_kfree;
-
-			copied += sizeof(*vec);
-			if (!isdigit(*str))
-				break;
-		}
-	}
-
-	if (newval && newlen) {
-		unsigned long __user *vec = newval;
-		size_t length = newlen / sizeof(*vec);
-		char *str, *end;
-		int i;
-		loff_t pos = 0;
-
-		str = buffer;
-		end = str + BUFSZ;
-		for (i = 0; i < length; i++) {
-			unsigned long value;
-
-			result = -EFAULT;
-			if (get_user(value, vec + i))
-				goto out_kfree;
-
-			str += scnprintf(str, end - str, "%lu\t", value);
-		}
-
-		result = kernel_write(file, buffer, str - buffer, &pos);
-		if (result < 0)
-			goto out_kfree;
-	}
-	result = copied;
-out_kfree:
-	kfree(buffer);
-out:
-	return result;
-}
-
-static ssize_t bin_uuid(struct file *file,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	ssize_t result, copied = 0;
-
-	/* Only supports reads */
-	if (oldval && oldlen) {
-		char buf[UUID_STRING_LEN + 1];
-		uuid_t uuid;
-		loff_t pos = 0;
-
-		result = kernel_read(file, buf, sizeof(buf) - 1, &pos);
-		if (result < 0)
-			goto out;
-
-		buf[result] = '\0';
-
-		result = -EIO;
-		if (uuid_parse(buf, &uuid))
-			goto out;
-
-		if (oldlen > 16)
-			oldlen = 16;
-
-		result = -EFAULT;
-		if (copy_to_user(oldval, &uuid, oldlen))
-			goto out;
-
-		copied = oldlen;
-	}
-	result = copied;
-out:
-	return result;
-}
-
-static ssize_t bin_dn_node_address(struct file *file,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	ssize_t result, copied = 0;
-
-	if (oldval && oldlen) {
-		char buf[15], *nodep;
-		unsigned long area, node;
-		__le16 dnaddr;
-		loff_t pos = 0;
-
-		result = kernel_read(file, buf, sizeof(buf) - 1, &pos);
-		if (result < 0)
-			goto out;
-
-		buf[result] = '\0';
-
-		/* Convert the decnet address to binary */
-		result = -EIO;
-		nodep = strchr(buf, '.');
-		if (!nodep)
-			goto out;
-		++nodep;
-
-		area = simple_strtoul(buf, NULL, 10);
-		node = simple_strtoul(nodep, NULL, 10);
-
-		result = -EIO;
-		if ((area > 63)||(node > 1023))
-			goto out;
-
-		dnaddr = cpu_to_le16((area << 10) | node);
-
-		result = -EFAULT;
-		if (put_user(dnaddr, (__le16 __user *)oldval))
-			goto out;
-
-		copied = sizeof(dnaddr);
-	}
-
-	if (newval && newlen) {
-		__le16 dnaddr;
-		char buf[15];
-		int len;
-		loff_t pos = 0;
-
-		result = -EINVAL;
-		if (newlen != sizeof(dnaddr))
-			goto out;
-
-		result = -EFAULT;
-		if (get_user(dnaddr, (__le16 __user *)newval))
-			goto out;
-
-		len = scnprintf(buf, sizeof(buf), "%hu.%hu",
-				le16_to_cpu(dnaddr) >> 10,
-				le16_to_cpu(dnaddr) & 0x3ff);
-
-		result = kernel_write(file, buf, len, &pos);
-		if (result < 0)
-			goto out;
-	}
-
-	result = copied;
-out:
-	return result;
-}
-
-static const struct bin_table *get_sysctl(const int *name, int nlen, char *path)
-{
-	const struct bin_table *table = &bin_root_table[0];
-	int ctl_name;
-
-	/* The binary sysctl tables have a small maximum depth so
-	 * there is no danger of overflowing our path as it PATH_MAX
-	 * bytes long.
-	 */
-	memcpy(path, "sys/", 4);
-	path += 4;
-
-repeat:
-	if (!nlen)
-		return ERR_PTR(-ENOTDIR);
-	ctl_name = *name;
-	name++;
-	nlen--;
-	for ( ; table->convert; table++) {
-		int len = 0;
-
-		/*
-		 * For a wild card entry map from ifindex to network
-		 * device name.
-		 */
-		if (!table->ctl_name) {
-#ifdef CONFIG_NET
-			struct net *net = current->nsproxy->net_ns;
-			struct net_device *dev;
-			dev = dev_get_by_index(net, ctl_name);
-			if (dev) {
-				len = strlen(dev->name);
-				memcpy(path, dev->name, len);
-				dev_put(dev);
-			}
-#endif
-		/* Use the well known sysctl number to proc name mapping */
-		} else if (ctl_name == table->ctl_name) {
-			len = strlen(table->procname);
-			memcpy(path, table->procname, len);
-		}
-		if (len) {
-			path += len;
-			if (table->child) {
-				*path++ = '/';
-				table = table->child;
-				goto repeat;
-			}
-			*path = '\0';
-			return table;
-		}
-	}
-	return ERR_PTR(-ENOTDIR);
-}
-
-static char *sysctl_getname(const int *name, int nlen, const struct bin_table **tablep)
-{
-	char *tmp, *result;
-
-	result = ERR_PTR(-ENOMEM);
-	tmp = __getname();
-	if (tmp) {
-		const struct bin_table *table = get_sysctl(name, nlen, tmp);
-		result = tmp;
-		*tablep = table;
-		if (IS_ERR(table)) {
-			__putname(tmp);
-			result = ERR_CAST(table);
-		}
-	}
-	return result;
-}
-
-static ssize_t binary_sysctl(const int *name, int nlen,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	const struct bin_table *table = NULL;
-	struct vfsmount *mnt;
-	struct file *file;
-	ssize_t result;
-	char *pathname;
-	int flags;
-
-	pathname = sysctl_getname(name, nlen, &table);
-	result = PTR_ERR(pathname);
-	if (IS_ERR(pathname))
-		goto out;
-
-	/* How should the sysctl be accessed? */
-	if (oldval && oldlen && newval && newlen) {
-		flags = O_RDWR;
-	} else if (newval && newlen) {
-		flags = O_WRONLY;
-	} else if (oldval && oldlen) {
-		flags = O_RDONLY;
-	} else {
-		result = 0;
-		goto out_putname;
-	}
-
-	mnt = task_active_pid_ns(current)->proc_mnt;
-	file = file_open_root(mnt->mnt_root, mnt, pathname, flags, 0);
-	result = PTR_ERR(file);
-	if (IS_ERR(file))
-		goto out_putname;
-
-	result = table->convert(file, oldval, oldlen, newval, newlen);
-
-	fput(file);
-out_putname:
-	__putname(pathname);
-out:
-	return result;
-}
-
-
-#else /* CONFIG_SYSCTL_SYSCALL */
-
-static ssize_t binary_sysctl(const int *name, int nlen,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	return -ENOSYS;
-}
-
-#endif /* CONFIG_SYSCTL_SYSCALL */
-
-
-static void deprecated_sysctl_warning(const int *name, int nlen)
-{
-	int i;
-
-	/*
-	 * CTL_KERN/KERN_VERSION is used by older glibc and cannot
-	 * ever go away.
-	 */
-	if (nlen >= 2 && name[0] == CTL_KERN && name[1] == KERN_VERSION)
-		return;
-
-	if (printk_ratelimit()) {
-		printk(KERN_INFO
-			"warning: process `%s' used the deprecated sysctl "
-			"system call with ", current->comm);
-		for (i = 0; i < nlen; i++)
-			printk(KERN_CONT "%d.", name[i]);
-		printk(KERN_CONT "\n");
-	}
-	return;
-}
-
-#define WARN_ONCE_HASH_BITS 8
-#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)
-
-static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);
-
-#define FNV32_OFFSET 2166136261U
-#define FNV32_PRIME 0x01000193
-
-/*
- * Print each legacy sysctl (approximately) only once.
- * To avoid making the tables non-const use a external
- * hash-table instead.
- * Worst case hash collision: 6, but very rarely.
- * NOTE! We don't use the SMP-safe bit tests. We simply
- * don't care enough.
- */
-static void warn_on_bintable(const int *name, int nlen)
-{
-	int i;
-	u32 hash = FNV32_OFFSET;
-
-	for (i = 0; i < nlen; i++)
-		hash = (hash ^ name[i]) * FNV32_PRIME;
-	hash %= WARN_ONCE_HASH_SIZE;
-	if (__test_and_set_bit(hash, warn_once_bitmap))
-		return;
-	deprecated_sysctl_warning(name, nlen);
-}
-
-static ssize_t do_sysctl(int __user *args_name, int nlen,
-	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
-	int name[CTL_MAXNAME];
-	int i;
-
-	/* Check args->nlen. */
-	if (nlen < 0 || nlen > CTL_MAXNAME)
-		return -ENOTDIR;
-	/* Read in the sysctl name for simplicity */
-	for (i = 0; i < nlen; i++)
-		if (get_user(name[i], args_name + i))
-			return -EFAULT;
-
-	warn_on_bintable(name, nlen);
-
-	return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
-}
-
-SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
-{
-	struct __sysctl_args tmp;
-	size_t oldlen = 0;
-	ssize_t result;
-
-	if (copy_from_user(&tmp, args, sizeof(tmp)))
-		return -EFAULT;
-
-	if (tmp.oldval && !tmp.oldlenp)
-		return -EFAULT;
-
-	if (tmp.oldlenp && get_user(oldlen, tmp.oldlenp))
-		return -EFAULT;
-
-	result = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, oldlen,
-			   tmp.newval, tmp.newlen);
-
-	if (result >= 0) {
-		oldlen = result;
-		result = 0;
-	}
-
-	if (tmp.oldlenp && put_user(oldlen, tmp.oldlenp))
-		return -EFAULT;
-
-	return result;
-}
-
-
-#ifdef CONFIG_COMPAT
-
-struct compat_sysctl_args {
-	compat_uptr_t	name;
-	int		nlen;
-	compat_uptr_t	oldval;
-	compat_uptr_t	oldlenp;
-	compat_uptr_t	newval;
-	compat_size_t	newlen;
-	compat_ulong_t	__unused[4];
-};
-
-COMPAT_SYSCALL_DEFINE1(sysctl, struct compat_sysctl_args __user *, args)
-{
-	struct compat_sysctl_args tmp;
-	compat_size_t __user *compat_oldlenp;
-	size_t oldlen = 0;
-	ssize_t result;
-
-	if (copy_from_user(&tmp, args, sizeof(tmp)))
-		return -EFAULT;
-
-	if (tmp.oldval && !tmp.oldlenp)
-		return -EFAULT;
-
-	compat_oldlenp = compat_ptr(tmp.oldlenp);
-	if (compat_oldlenp && get_user(oldlen, compat_oldlenp))
-		return -EFAULT;
-
-	result = do_sysctl(compat_ptr(tmp.name), tmp.nlen,
-			   compat_ptr(tmp.oldval), oldlen,
-			   compat_ptr(tmp.newval), tmp.newlen);
-
-	if (result >= 0) {
-		oldlen = result;
-		result = 0;
-	}
-
-	if (compat_oldlenp && put_user(oldlen, compat_oldlenp))
-		return -EFAULT;
-
-	return result;
-}
-
-#endif /* CONFIG_COMPAT */
diff --git a/kernel/task_work.c b/kernel/task_work.c
index 0fef395..8d6e121 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -9,25 +9,31 @@
  * task_work_add - ask the @task to execute @work->func()
  * @task: the task which should run the callback
  * @work: the callback to run
- * @notify: send the notification if true
+ * @notify: how to notify the targeted task
  *
- * Queue @work for task_work_run() below and notify the @task if @notify.
- * Fails if the @task is exiting/exited and thus it can't process this @work.
- * Otherwise @work->func() will be called when the @task returns from kernel
- * mode or exits.
+ * Queue @work for task_work_run() below and notify the @task if @notify
+ * is @TWA_RESUME or @TWA_SIGNAL. @TWA_SIGNAL works like signals, in that the
+ * it will interrupt the targeted task and run the task_work. @TWA_RESUME
+ * work is run only when the task exits the kernel and returns to user mode,
+ * or before entering guest mode. Fails if the @task is exiting/exited and thus
+ * it can't process this @work. Otherwise @work->func() will be called when the
+ * @task goes through one of the aforementioned transitions, or exits.
  *
- * This is like the signal handler which runs in kernel mode, but it doesn't
- * try to wake up the @task.
+ * If the targeted task is exiting, then an error is returned and the work item
+ * is not queued. It's up to the caller to arrange for an alternative mechanism
+ * in that case.
  *
- * Note: there is no ordering guarantee on works queued here.
+ * Note: there is no ordering guarantee on works queued here. The task_work
+ * list is LIFO.
  *
  * RETURNS:
  * 0 if succeeds or -ESRCH.
  */
-int
-task_work_add(struct task_struct *task, struct callback_head *work, bool notify)
+int task_work_add(struct task_struct *task, struct callback_head *work,
+		  enum task_work_notify_mode notify)
 {
 	struct callback_head *head;
+	unsigned long flags;
 
 	do {
 		head = READ_ONCE(task->task_works);
@@ -36,8 +42,30 @@
 		work->next = head;
 	} while (cmpxchg(&task->task_works, head, work) != head);
 
-	if (notify)
+	switch (notify) {
+	case TWA_NONE:
+		break;
+	case TWA_RESUME:
 		set_notify_resume(task);
+		break;
+	case TWA_SIGNAL:
+		/*
+		 * Only grab the sighand lock if we don't already have some
+		 * task_work pending. This pairs with the smp_store_mb()
+		 * in get_signal(), see comment there.
+		 */
+		if (!(READ_ONCE(task->jobctl) & JOBCTL_TASK_WORK) &&
+		    lock_task_sighand(task, &flags)) {
+			task->jobctl |= JOBCTL_TASK_WORK;
+			signal_wake_up(task, 0);
+			unlock_task_sighand(task, &flags);
+		}
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+
 	return 0;
 }
 
@@ -97,16 +125,26 @@
 		 * work->func() can do task_work_add(), do not set
 		 * work_exited unless the list is empty.
 		 */
-		raw_spin_lock_irq(&task->pi_lock);
 		do {
+			head = NULL;
 			work = READ_ONCE(task->task_works);
-			head = !work && (task->flags & PF_EXITING) ?
-				&work_exited : NULL;
+			if (!work) {
+				if (task->flags & PF_EXITING)
+					head = &work_exited;
+				else
+					break;
+			}
 		} while (cmpxchg(&task->task_works, work, head) != work);
-		raw_spin_unlock_irq(&task->pi_lock);
 
 		if (!work)
 			break;
+		/*
+		 * Synchronize with task_work_cancel(). It can not remove
+		 * the first entry == work, cmpxchg(task_works) must fail.
+		 * But it can remove another entry from the ->next list.
+		 */
+		raw_spin_lock_irq(&task->pi_lock);
+		raw_spin_unlock_irq(&task->pi_lock);
 
 		do {
 			next = work->next;
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index e2ac0e3..a2802b6 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -34,17 +34,13 @@
 
 static struct genl_family family;
 
-static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
+static const struct nla_policy taskstats_cmd_get_policy[] = {
 	[TASKSTATS_CMD_ATTR_PID]  = { .type = NLA_U32 },
 	[TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 },
 	[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING },
 	[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
 
-/*
- * We have to use TASKSTATS_CMD_ATTR_MAX here, it is the maxattr in the family.
- * Make sure they are always aligned.
- */
-static const struct nla_policy cgroupstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
+static const struct nla_policy cgroupstats_cmd_get_policy[] = {
 	[CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },
 };
 
@@ -649,47 +645,25 @@
 		.cmd		= TASKSTATS_CMD_GET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit		= taskstats_user_cmd,
-		/* policy enforced later */
-		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_HASPOL,
+		.policy		= taskstats_cmd_get_policy,
+		.maxattr	= ARRAY_SIZE(taskstats_cmd_get_policy) - 1,
+		.flags		= GENL_ADMIN_PERM,
 	},
 	{
 		.cmd		= CGROUPSTATS_CMD_GET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit		= cgroupstats_user_cmd,
-		/* policy enforced later */
-		.flags		= GENL_CMD_CAP_HASPOL,
+		.policy		= cgroupstats_cmd_get_policy,
+		.maxattr	= ARRAY_SIZE(cgroupstats_cmd_get_policy) - 1,
 	},
 };
 
-static int taskstats_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
-			      struct genl_info *info)
-{
-	const struct nla_policy *policy = NULL;
-
-	switch (ops->cmd) {
-	case TASKSTATS_CMD_GET:
-		policy = taskstats_cmd_get_policy;
-		break;
-	case CGROUPSTATS_CMD_GET:
-		policy = cgroupstats_cmd_get_policy;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	return nlmsg_validate_deprecated(info->nlhdr, GENL_HDRLEN,
-					 TASKSTATS_CMD_ATTR_MAX, policy,
-					 info->extack);
-}
-
 static struct genl_family family __ro_after_init = {
 	.name		= TASKSTATS_GENL_NAME,
 	.version	= TASKSTATS_GENL_VERSION,
-	.maxattr	= TASKSTATS_CMD_ATTR_MAX,
 	.module		= THIS_MODULE,
 	.ops		= taskstats_ops,
 	.n_ops		= ARRAY_SIZE(taskstats_ops),
-	.pre_doit	= taskstats_pre_doit,
 };
 
 /* Needed early in initialization */
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index fcc4235..a09b1d6 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -52,6 +52,15 @@
 config GENERIC_CMOS_UPDATE
 	bool
 
+# Select to handle posix CPU timers from task_work
+# and not from the timer interrupt context
+config HAVE_POSIX_CPU_TIMERS_TASK_WORK
+	bool
+
+config POSIX_CPU_TIMERS_TASK_WORK
+	bool
+	default y if POSIX_TIMERS && HAVE_POSIX_CPU_TIMERS_TASK_WORK
+
 if GENERIC_CLOCKEVENTS
 menu "Timers subsystem"
 
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 1867044..c8f0016 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -19,3 +19,4 @@
 obj-$(CONFIG_HAVE_GENERIC_VDSO)			+= vsyscall.o
 obj-$(CONFIG_DEBUG_FS)				+= timekeeping_debug.o
 obj-$(CONFIG_TEST_UDELAY)			+= test_udelay.o
+obj-$(CONFIG_TIME_NS)				+= namespace.o
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 0e96c38..daeaa71 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -26,6 +26,7 @@
 #include <linux/freezer.h>
 #include <linux/compat.h>
 #include <linux/module.h>
+#include <linux/time_namespace.h>
 
 #include "posix-timers.h"
 
@@ -36,13 +37,15 @@
  * struct alarm_base - Alarm timer bases
  * @lock:		Lock for syncrhonized access to the base
  * @timerqueue:		Timerqueue head managing the list of events
- * @gettime:		Function to read the time correlating to the base
+ * @get_ktime:		Function to read the time correlating to the base
+ * @get_timespec:	Function to read the namespace time correlating to the base
  * @base_clockid:	clockid for the base
  */
 static struct alarm_base {
 	spinlock_t		lock;
 	struct timerqueue_head	timerqueue;
-	ktime_t			(*gettime)(void);
+	ktime_t			(*get_ktime)(void);
+	void			(*get_timespec)(struct timespec64 *tp);
 	clockid_t		base_clockid;
 } alarm_bases[ALARM_NUMTYPE];
 
@@ -55,8 +58,6 @@
 #endif
 
 #ifdef CONFIG_RTC_CLASS
-static struct wakeup_source *ws;
-
 /* rtc timer and device for setting alarm wakeups at suspend */
 static struct rtc_timer		rtctimer;
 static struct rtc_device	*rtcdev;
@@ -66,8 +67,6 @@
  * alarmtimer_get_rtcdev - Return selected rtcdevice
  *
  * This function returns the rtc device to use for wakealarms.
- * If one has not already been chosen, it checks to see if a
- * functional rtc device is available.
  */
 struct rtc_device *alarmtimer_get_rtcdev(void)
 {
@@ -87,7 +86,6 @@
 {
 	unsigned long flags;
 	struct rtc_device *rtc = to_rtc_device(dev);
-	struct wakeup_source *__ws;
 	struct platform_device *pdev;
 	int ret = 0;
 
@@ -99,12 +97,13 @@
 	if (!device_may_wakeup(rtc->dev.parent))
 		return -1;
 
-	__ws = wakeup_source_register(dev, "alarmtimer");
 	pdev = platform_device_register_data(dev, "alarmtimer",
 					     PLATFORM_DEVID_AUTO, NULL, 0);
+	if (!IS_ERR(pdev))
+		device_init_wakeup(&pdev->dev, true);
 
 	spin_lock_irqsave(&rtcdev_lock, flags);
-	if (__ws && !IS_ERR(pdev) && !rtcdev) {
+	if (!IS_ERR(pdev) && !rtcdev) {
 		if (!try_module_get(rtc->owner)) {
 			ret = -1;
 			goto unlock;
@@ -113,8 +112,6 @@
 		rtcdev = rtc;
 		/* hold a reference so it doesn't go away */
 		get_device(dev);
-		ws = __ws;
-		__ws = NULL;
 		pdev = NULL;
 	} else {
 		ret = -1;
@@ -123,7 +120,6 @@
 	spin_unlock_irqrestore(&rtcdev_lock, flags);
 
 	platform_device_unregister(pdev);
-	wakeup_source_unregister(__ws);
 
 	return ret;
 }
@@ -147,11 +143,6 @@
 	class_interface_unregister(&alarmtimer_rtc_interface);
 }
 #else
-struct rtc_device *alarmtimer_get_rtcdev(void)
-{
-	return NULL;
-}
-#define rtcdev (NULL)
 static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
 static inline void alarmtimer_rtc_interface_remove(void) { }
 static inline void alarmtimer_rtc_timer_init(void) { }
@@ -201,7 +192,7 @@
  * When a alarm timer fires, this runs through the timerqueue to
  * see which alarms expired, and runs those. If there are more alarm
  * timers queued for the future, we set the hrtimer to fire when
- * when the next future alarm timer expires.
+ * the next future alarm timer expires.
  */
 static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
 {
@@ -216,7 +207,7 @@
 	spin_unlock_irqrestore(&base->lock, flags);
 
 	if (alarm->function)
-		restart = alarm->function(alarm, base->gettime());
+		restart = alarm->function(alarm, base->get_ktime());
 
 	spin_lock_irqsave(&base->lock, flags);
 	if (restart != ALARMTIMER_NORESTART) {
@@ -226,7 +217,7 @@
 	}
 	spin_unlock_irqrestore(&base->lock, flags);
 
-	trace_alarmtimer_fired(alarm, base->gettime());
+	trace_alarmtimer_fired(alarm, base->get_ktime());
 	return ret;
 
 }
@@ -234,7 +225,7 @@
 ktime_t alarm_expires_remaining(const struct alarm *alarm)
 {
 	struct alarm_base *base = &alarm_bases[alarm->type];
-	return ktime_sub(alarm->node.expires, base->gettime());
+	return ktime_sub(alarm->node.expires, base->get_ktime());
 }
 EXPORT_SYMBOL_GPL(alarm_expires_remaining);
 
@@ -279,7 +270,7 @@
 		spin_unlock_irqrestore(&base->lock, flags);
 		if (!next)
 			continue;
-		delta = ktime_sub(next->expires, base->gettime());
+		delta = ktime_sub(next->expires, base->get_ktime());
 		if (!min || (delta < min)) {
 			expires = next->expires;
 			min = delta;
@@ -290,7 +281,7 @@
 		return 0;
 
 	if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
-		__pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
+		pm_wakeup_event(dev, 2 * MSEC_PER_SEC);
 		return -EBUSY;
 	}
 
@@ -305,7 +296,7 @@
 	/* Set alarm, if in the past reject suspend briefly to handle */
 	ret = rtc_timer_start(rtc, &rtctimer, now, 0);
 	if (ret < 0)
-		__pm_wakeup_event(ws, MSEC_PER_SEC);
+		pm_wakeup_event(dev, MSEC_PER_SEC);
 	return ret;
 }
 
@@ -373,7 +364,7 @@
 	hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
 	spin_unlock_irqrestore(&base->lock, flags);
 
-	trace_alarmtimer_start(alarm, base->gettime());
+	trace_alarmtimer_start(alarm, base->get_ktime());
 }
 EXPORT_SYMBOL_GPL(alarm_start);
 
@@ -386,7 +377,7 @@
 {
 	struct alarm_base *base = &alarm_bases[alarm->type];
 
-	start = ktime_add_safe(start, base->gettime());
+	start = ktime_add_safe(start, base->get_ktime());
 	alarm_start(alarm, start);
 }
 EXPORT_SYMBOL_GPL(alarm_start_relative);
@@ -423,7 +414,7 @@
 		alarmtimer_dequeue(base, alarm);
 	spin_unlock_irqrestore(&base->lock, flags);
 
-	trace_alarmtimer_cancel(alarm, base->gettime());
+	trace_alarmtimer_cancel(alarm, base->get_ktime());
 	return ret;
 }
 EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
@@ -483,7 +474,7 @@
 {
 	struct alarm_base *base = &alarm_bases[alarm->type];
 
-	return alarm_forward(alarm, base->gettime(), interval);
+	return alarm_forward(alarm, base->get_ktime(), interval);
 }
 EXPORT_SYMBOL_GPL(alarm_forward_now);
 
@@ -509,7 +500,7 @@
 		return;
 	}
 
-	delta = ktime_sub(absexp, base->gettime());
+	delta = ktime_sub(absexp, base->get_ktime());
 
 	spin_lock_irqsave(&freezer_delta_lock, flags);
 	if (!freezer_delta || (delta < freezer_delta)) {
@@ -641,7 +632,7 @@
 	struct alarm_base *base = &alarm_bases[alarm->type];
 
 	if (!absolute)
-		expires = ktime_add_safe(expires, base->gettime());
+		expires = ktime_add_safe(expires, base->get_ktime());
 	if (sigev_none)
 		alarm->node.expires = expires;
 	else
@@ -666,24 +657,41 @@
 }
 
 /**
- * alarm_clock_get - posix clock_get interface
+ * alarm_clock_get_timespec - posix clock_get_timespec interface
  * @which_clock: clockid
  * @tp: timespec to fill.
  *
- * Provides the underlying alarm base time.
+ * Provides the underlying alarm base time in a tasks time namespace.
  */
-static int alarm_clock_get(clockid_t which_clock, struct timespec64 *tp)
+static int alarm_clock_get_timespec(clockid_t which_clock, struct timespec64 *tp)
 {
 	struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
 
 	if (!alarmtimer_get_rtcdev())
 		return -EINVAL;
 
-	*tp = ktime_to_timespec64(base->gettime());
+	base->get_timespec(tp);
+
 	return 0;
 }
 
 /**
+ * alarm_clock_get_ktime - posix clock_get_ktime interface
+ * @which_clock: clockid
+ *
+ * Provides the underlying alarm base time in the root namespace.
+ */
+static ktime_t alarm_clock_get_ktime(clockid_t which_clock)
+{
+	struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
+
+	if (!alarmtimer_get_rtcdev())
+		return -EINVAL;
+
+	return base->get_ktime();
+}
+
+/**
  * alarm_timer_create - posix timer_create interface
  * @new_timer: k_itimer pointer to manage
  *
@@ -756,7 +764,7 @@
 		struct timespec64 rmt;
 		ktime_t rem;
 
-		rem = ktime_sub(absexp, alarm_bases[type].gettime());
+		rem = ktime_sub(absexp, alarm_bases[type].get_ktime());
 
 		if (rem <= 0)
 			return 0;
@@ -825,9 +833,11 @@
 	exp = timespec64_to_ktime(*tsreq);
 	/* Convert (if necessary) to absolute time */
 	if (flags != TIMER_ABSTIME) {
-		ktime_t now = alarm_bases[type].gettime();
+		ktime_t now = alarm_bases[type].get_ktime();
 
 		exp = ktime_add_safe(now, exp);
+	} else {
+		exp = timens_ktime_to_host(which_clock, exp);
 	}
 
 	ret = alarmtimer_do_nsleep(&alarm, exp, type);
@@ -846,7 +856,8 @@
 
 const struct k_clock alarm_clock = {
 	.clock_getres		= alarm_clock_getres,
-	.clock_get		= alarm_clock_get,
+	.clock_get_ktime	= alarm_clock_get_ktime,
+	.clock_get_timespec	= alarm_clock_get_timespec,
 	.timer_create		= alarm_timer_create,
 	.timer_set		= common_timer_set,
 	.timer_del		= common_timer_del,
@@ -875,6 +886,12 @@
 	}
 };
 
+static void get_boottime_timespec(struct timespec64 *tp)
+{
+	ktime_get_boottime_ts64(tp);
+	timens_add_boottime(tp);
+}
+
 /**
  * alarmtimer_init - Initialize alarm timer code
  *
@@ -890,9 +907,11 @@
 
 	/* Initialize alarm bases */
 	alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
-	alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
+	alarm_bases[ALARM_REALTIME].get_ktime = &ktime_get_real;
+	alarm_bases[ALARM_REALTIME].get_timespec = ktime_get_real_ts64;
 	alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
-	alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
+	alarm_bases[ALARM_BOOTTIME].get_ktime = &ktime_get_boottime;
+	alarm_bases[ALARM_BOOTTIME].get_timespec = get_boottime_timespec;
 	for (i = 0; i < ALARM_NUMTYPE; i++) {
 		timerqueue_init_head(&alarm_bases[i].timerqueue);
 		spin_lock_init(&alarm_bases[i].lock);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 6863a05..e34ceb9 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -93,6 +93,20 @@
 static int finished_booting;
 static u64 suspend_start;
 
+/*
+ * Threshold: 0.0312s, when doubled: 0.0625s.
+ * Also a default for cs->uncertainty_margin when registering clocks.
+ */
+#define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 5)
+
+/*
+ * Maximum permissible delay between two readouts of the watchdog
+ * clocksource surrounding a read of the clocksource being validated.
+ * This delay could be due to SMIs, NMIs, or to VCPU preemptions.  Used as
+ * a lower bound for cs->uncertainty_margin values when registering clocks.
+ */
+#define WATCHDOG_MAX_SKEW (100 * NSEC_PER_USEC)
+
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
 static void clocksource_watchdog_work(struct work_struct *work);
 static void clocksource_select(void);
@@ -119,17 +133,9 @@
 static void __clocksource_change_rating(struct clocksource *cs, int rating);
 
 /*
- * Interval: 0.5sec Threshold: 0.0625s
+ * Interval: 0.5sec.
  */
 #define WATCHDOG_INTERVAL (HZ >> 1)
-#define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4)
-
-/*
- * Maximum permissible delay between two readouts of the watchdog
- * clocksource surrounding a read of the clocksource being validated.
- * This delay could be due to SMIs, NMIs, or to VCPU preemptions.
- */
-#define WATCHDOG_MAX_SKEW (100 * NSEC_PER_USEC)
 
 static void clocksource_watchdog_work(struct work_struct *work)
 {
@@ -194,17 +200,24 @@
 static ulong max_cswd_read_retries = 3;
 module_param(max_cswd_read_retries, ulong, 0644);
 
-static bool cs_watchdog_read(struct clocksource *cs, u64 *csnow, u64 *wdnow)
+enum wd_read_status {
+	WD_READ_SUCCESS,
+	WD_READ_UNSTABLE,
+	WD_READ_SKIP
+};
+
+static enum wd_read_status cs_watchdog_read(struct clocksource *cs, u64 *csnow, u64 *wdnow)
 {
 	unsigned int nretries;
-	u64 wd_end, wd_delta;
-	int64_t wd_delay;
+	u64 wd_end, wd_end2, wd_delta;
+	int64_t wd_delay, wd_seq_delay;
 
 	for (nretries = 0; nretries <= max_cswd_read_retries; nretries++) {
 		local_irq_disable();
 		*wdnow = watchdog->read(watchdog);
 		*csnow = cs->read(cs);
 		wd_end = watchdog->read(watchdog);
+		wd_end2 = watchdog->read(watchdog);
 		local_irq_enable();
 
 		wd_delta = clocksource_delta(wd_end, *wdnow, watchdog->mask);
@@ -215,13 +228,88 @@
 				pr_warn("timekeeping watchdog on CPU%d: %s retried %d times before success\n",
 					smp_processor_id(), watchdog->name, nretries);
 			}
-			return true;
+			return WD_READ_SUCCESS;
 		}
+
+		/*
+		 * Now compute delay in consecutive watchdog read to see if
+		 * there is too much external interferences that cause
+		 * significant delay in reading both clocksource and watchdog.
+		 *
+		 * If consecutive WD read-back delay > WATCHDOG_MAX_SKEW/2,
+		 * report system busy, reinit the watchdog and skip the current
+		 * watchdog test.
+		 */
+		wd_delta = clocksource_delta(wd_end2, wd_end, watchdog->mask);
+		wd_seq_delay = clocksource_cyc2ns(wd_delta, watchdog->mult, watchdog->shift);
+		if (wd_seq_delay > WATCHDOG_MAX_SKEW/2)
+			goto skip_test;
 	}
 
 	pr_warn("timekeeping watchdog on CPU%d: %s read-back delay of %lldns, attempt %d, marking unstable\n",
 		smp_processor_id(), watchdog->name, wd_delay, nretries);
-	return false;
+	return WD_READ_UNSTABLE;
+
+skip_test:
+	pr_info("timekeeping watchdog on CPU%d: %s wd-wd read-back delay of %lldns\n",
+		smp_processor_id(), watchdog->name, wd_seq_delay);
+	pr_info("wd-%s-wd read-back delay of %lldns, clock-skew test skipped!\n",
+		cs->name, wd_delay);
+	return WD_READ_SKIP;
+}
+
+static u64 csnow_mid;
+static cpumask_t cpus_ahead;
+static cpumask_t cpus_behind;
+
+static void clocksource_verify_one_cpu(void *csin)
+{
+	struct clocksource *cs = (struct clocksource *)csin;
+
+	csnow_mid = cs->read(cs);
+}
+
+static void clocksource_verify_percpu(struct clocksource *cs)
+{
+	int64_t cs_nsec, cs_nsec_max = 0, cs_nsec_min = LLONG_MAX;
+	u64 csnow_begin, csnow_end;
+	int cpu, testcpu;
+	s64 delta;
+
+	cpumask_clear(&cpus_ahead);
+	cpumask_clear(&cpus_behind);
+	preempt_disable();
+	testcpu = smp_processor_id();
+	pr_warn("Checking clocksource %s synchronization from CPU %d.\n", cs->name, testcpu);
+	for_each_online_cpu(cpu) {
+		if (cpu == testcpu)
+			continue;
+		csnow_begin = cs->read(cs);
+		smp_call_function_single(cpu, clocksource_verify_one_cpu, cs, 1);
+		csnow_end = cs->read(cs);
+		delta = (s64)((csnow_mid - csnow_begin) & cs->mask);
+		if (delta < 0)
+			cpumask_set_cpu(cpu, &cpus_behind);
+		delta = (csnow_end - csnow_mid) & cs->mask;
+		if (delta < 0)
+			cpumask_set_cpu(cpu, &cpus_ahead);
+		delta = clocksource_delta(csnow_end, csnow_begin, cs->mask);
+		cs_nsec = clocksource_cyc2ns(delta, cs->mult, cs->shift);
+		if (cs_nsec > cs_nsec_max)
+			cs_nsec_max = cs_nsec;
+		if (cs_nsec < cs_nsec_min)
+			cs_nsec_min = cs_nsec;
+	}
+	preempt_enable();
+	if (!cpumask_empty(&cpus_ahead))
+		pr_warn("        CPUs %*pbl ahead of CPU %d for clocksource %s.\n",
+			cpumask_pr_args(&cpus_ahead), testcpu, cs->name);
+	if (!cpumask_empty(&cpus_behind))
+		pr_warn("        CPUs %*pbl behind CPU %d for clocksource %s.\n",
+			cpumask_pr_args(&cpus_behind), testcpu, cs->name);
+	if (!cpumask_empty(&cpus_ahead) || !cpumask_empty(&cpus_behind))
+		pr_warn("        CPU %d check durations %lldns - %lldns for clocksource %s.\n",
+			testcpu, cs_nsec_min, cs_nsec_max, cs->name);
 }
 
 static void clocksource_watchdog(struct timer_list *unused)
@@ -230,6 +318,8 @@
 	int next_cpu, reset_pending;
 	int64_t wd_nsec, cs_nsec;
 	struct clocksource *cs;
+	enum wd_read_status read_ret;
+	u32 md;
 
 	spin_lock(&watchdog_lock);
 	if (!watchdog_running)
@@ -246,9 +336,12 @@
 			continue;
 		}
 
-		if (!cs_watchdog_read(cs, &csnow, &wdnow)) {
-			/* Clock readout unreliable, so give it up. */
-			__clocksource_unstable(cs);
+		read_ret = cs_watchdog_read(cs, &csnow, &wdnow);
+
+		if (read_ret != WD_READ_SUCCESS) {
+			if (read_ret == WD_READ_UNSTABLE)
+				/* Clock readout unreliable, so give it up. */
+				__clocksource_unstable(cs);
 			continue;
 		}
 
@@ -276,7 +369,8 @@
 			continue;
 
 		/* Check the deviation from the watchdog clocksource. */
-		if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
+		md = cs->uncertainty_margin + watchdog->uncertainty_margin;
+		if (abs(cs_nsec - wd_nsec) > md) {
 			pr_warn("timekeeping watchdog on CPU%d: Marking clocksource '%s' as unstable because the skew is too large:\n",
 				smp_processor_id(), cs->name);
 			pr_warn("                      '%s' wd_now: %llx wd_last: %llx mask: %llx\n",
@@ -448,6 +542,12 @@
 	unsigned long flags;
 	int select = 0;
 
+	/* Do any required per-CPU skew verification. */
+	if (curr_clocksource &&
+	    curr_clocksource->flags & CLOCK_SOURCE_UNSTABLE &&
+	    curr_clocksource->flags & CLOCK_SOURCE_VERIFY_PERCPU)
+		clocksource_verify_percpu(curr_clocksource);
+
 	spin_lock_irqsave(&watchdog_lock, flags);
 	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
 		if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
@@ -925,6 +1025,26 @@
 		clocks_calc_mult_shift(&cs->mult, &cs->shift, freq,
 				       NSEC_PER_SEC / scale, sec * scale);
 	}
+
+	/*
+	 * If the uncertainty margin is not specified, calculate it.
+	 * If both scale and freq are non-zero, calculate the clock
+	 * period, but bound below at 2*WATCHDOG_MAX_SKEW.  However,
+	 * if either of scale or freq is zero, be very conservative and
+	 * take the tens-of-milliseconds WATCHDOG_THRESHOLD value for the
+	 * uncertainty margin.  Allow stupidly small uncertainty margins
+	 * to be specified by the caller for testing purposes, but warn
+	 * to discourage production use of this capability.
+	 */
+	if (scale && freq && !cs->uncertainty_margin) {
+		cs->uncertainty_margin = NSEC_PER_SEC / (scale * freq);
+		if (cs->uncertainty_margin < 2 * WATCHDOG_MAX_SKEW)
+			cs->uncertainty_margin = 2 * WATCHDOG_MAX_SKEW;
+	} else if (!cs->uncertainty_margin) {
+		cs->uncertainty_margin = WATCHDOG_THRESHOLD;
+	}
+	WARN_ON_ONCE(cs->uncertainty_margin < 2 * WATCHDOG_MAX_SKEW);
+
 	/*
 	 * Ensure clocksources that have large 'mult' values don't overflow
 	 * when adjusted.
@@ -969,6 +1089,13 @@
 
 	clocksource_arch_init(cs);
 
+	if (cs->vdso_clock_mode < 0 ||
+	    cs->vdso_clock_mode >= VDSO_CLOCKMODE_MAX) {
+		pr_warn("clocksource %s registered with invalid VDSO mode %d. Disabling VDSO support.\n",
+			cs->name, cs->vdso_clock_mode);
+		cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
+	}
+
 	/* Initialize mult/shift and max_idle_ns */
 	__clocksource_update_freq_scale(cs, scale, freq);
 
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index e1e8d5d..4ef9071 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -135,7 +135,11 @@
  * timer->base->cpu_base
  */
 static struct hrtimer_cpu_base migration_cpu_base = {
-	.clock_base = { { .cpu_base = &migration_cpu_base, }, },
+	.clock_base = { {
+		.cpu_base = &migration_cpu_base,
+		.seq      = SEQCNT_RAW_SPINLOCK_ZERO(migration_cpu_base.seq,
+						     &migration_cpu_base.lock),
+	}, },
 };
 
 #define migration_base	migration_cpu_base.clock_base[0]
@@ -311,7 +315,7 @@
 		div >>= 1;
 	}
 	tmp >>= sft;
-	do_div(tmp, (unsigned long) div);
+	do_div(tmp, (u32) div);
 	return dclc < 0 ? -tmp : tmp;
 }
 EXPORT_SYMBOL_GPL(__ktime_divns);
@@ -338,7 +342,7 @@
 
 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 
-static struct debug_obj_descr hrtimer_debug_descr;
+static const struct debug_obj_descr hrtimer_debug_descr;
 
 static void *hrtimer_debug_hint(void *addr)
 {
@@ -373,7 +377,7 @@
 	switch (state) {
 	case ODEBUG_STATE_ACTIVE:
 		WARN_ON(1);
-		/* fall through */
+		fallthrough;
 	default:
 		return false;
 	}
@@ -397,7 +401,7 @@
 	}
 }
 
-static struct debug_obj_descr hrtimer_debug_descr = {
+static const struct debug_obj_descr hrtimer_debug_descr = {
 	.name		= "hrtimer",
 	.debug_hint	= hrtimer_debug_hint,
 	.fixup_init	= hrtimer_fixup_init,
@@ -421,11 +425,6 @@
 	debug_object_deactivate(timer, &hrtimer_debug_descr);
 }
 
-static inline void debug_hrtimer_free(struct hrtimer *timer)
-{
-	debug_object_free(timer, &hrtimer_debug_descr);
-}
-
 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 			   enum hrtimer_mode mode);
 
@@ -1468,7 +1467,7 @@
 	base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0;
 	base += hrtimer_clockid_to_base(clock_id);
 	timer->is_soft = softtimer;
-	timer->is_hard = !softtimer;
+	timer->is_hard = !!(mode & HRTIMER_MODE_HARD);
 	timer->base = &cpu_base->clock_base[base];
 	timerqueue_init(&timer->node);
 }
@@ -1541,9 +1540,10 @@
 static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
 			  struct hrtimer_clock_base *base,
 			  struct hrtimer *timer, ktime_t *now,
-			  unsigned long flags)
+			  unsigned long flags) __must_hold(&cpu_base->lock)
 {
 	enum hrtimer_restart (*fn)(struct hrtimer *);
+	bool expires_in_hardirq;
 	int restart;
 
 	lockdep_assert_held(&cpu_base->lock);
@@ -1578,7 +1578,11 @@
 	 */
 	raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
 	trace_hrtimer_expire_entry(timer, now);
+	expires_in_hardirq = lockdep_hrtimer_enter(timer);
+
 	restart = fn(timer);
+
+	lockdep_hrtimer_exit(expires_in_hardirq);
 	trace_hrtimer_expire_exit(timer);
 	raw_spin_lock_irq(&cpu_base->lock);
 
@@ -1974,8 +1978,8 @@
 	return ret;
 }
 
-long hrtimer_nanosleep(const struct timespec64 *rqtp,
-		       const enum hrtimer_mode mode, const clockid_t clockid)
+long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
+		       const clockid_t clockid)
 {
 	struct restart_block *restart;
 	struct hrtimer_sleeper t;
@@ -1987,7 +1991,7 @@
 		slack = 0;
 
 	hrtimer_init_sleeper_on_stack(&t, clockid, mode);
-	hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack);
+	hrtimer_set_expires_range_ns(&t.timer, rqtp, slack);
 	ret = do_nanosleep(&t, mode);
 	if (ret != -ERESTART_RESTARTBLOCK)
 		goto out;
@@ -2007,7 +2011,7 @@
 	return ret;
 }
 
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 
 SYSCALL_DEFINE2(nanosleep, struct __kernel_timespec __user *, rqtp,
 		struct __kernel_timespec __user *, rmtp)
@@ -2022,7 +2026,8 @@
 
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
-	return hrtimer_nanosleep(&tu, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+	return hrtimer_nanosleep(timespec64_to_ktime(tu), HRTIMER_MODE_REL,
+				 CLOCK_MONOTONIC);
 }
 
 #endif
@@ -2042,7 +2047,8 @@
 
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
-	return hrtimer_nanosleep(&tu, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+	return hrtimer_nanosleep(timespec64_to_ktime(tu), HRTIMER_MODE_REL,
+				 CLOCK_MONOTONIC);
 }
 #endif
 
@@ -2055,8 +2061,11 @@
 	int i;
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
-		cpu_base->clock_base[i].cpu_base = cpu_base;
-		timerqueue_init_head(&cpu_base->clock_base[i].active);
+		struct hrtimer_clock_base *clock_b = &cpu_base->clock_base[i];
+
+		clock_b->cpu_base = cpu_base;
+		seqcount_raw_spinlock_init(&clock_b->seq, &cpu_base->lock);
+		timerqueue_init_head(&clock_b->active);
 	}
 
 	cpu_base->cpu = cpu;
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index 62dc975..00629e6 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -26,7 +26,7 @@
  * Returns the delta between the expiry time and now, which can be
  * less than zero or 1usec for an pending expired timer
  */
-static struct timeval itimer_get_remtime(struct hrtimer *timer)
+static struct timespec64 itimer_get_remtime(struct hrtimer *timer)
 {
 	ktime_t rem = __hrtimer_get_remaining(timer, true);
 
@@ -41,11 +41,11 @@
 	} else
 		rem = 0;
 
-	return ktime_to_timeval(rem);
+	return ktime_to_timespec64(rem);
 }
 
 static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
-			   struct itimerval *const value)
+			   struct itimerspec64 *const value)
 {
 	u64 val, interval;
 	struct cpu_itimer *it = &tsk->signal->it[clock_id];
@@ -69,11 +69,11 @@
 
 	spin_unlock_irq(&tsk->sighand->siglock);
 
-	value->it_value = ns_to_timeval(val);
-	value->it_interval = ns_to_timeval(interval);
+	value->it_value = ns_to_timespec64(val);
+	value->it_interval = ns_to_timespec64(interval);
 }
 
-int do_getitimer(int which, struct itimerval *value)
+static int do_getitimer(int which, struct itimerspec64 *value)
 {
 	struct task_struct *tsk = current;
 
@@ -82,7 +82,7 @@
 		spin_lock_irq(&tsk->sighand->siglock);
 		value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
 		value->it_interval =
-			ktime_to_timeval(tsk->signal->it_real_incr);
+			ktime_to_timespec64(tsk->signal->it_real_incr);
 		spin_unlock_irq(&tsk->sighand->siglock);
 		break;
 	case ITIMER_VIRTUAL:
@@ -97,34 +97,59 @@
 	return 0;
 }
 
-SYSCALL_DEFINE2(getitimer, int, which, struct itimerval __user *, value)
+static int put_itimerval(struct __kernel_old_itimerval __user *o,
+			 const struct itimerspec64 *i)
 {
-	int error = -EFAULT;
-	struct itimerval get_buffer;
+	struct __kernel_old_itimerval v;
 
-	if (value) {
-		error = do_getitimer(which, &get_buffer);
-		if (!error &&
-		    copy_to_user(value, &get_buffer, sizeof(get_buffer)))
-			error = -EFAULT;
-	}
+	v.it_interval.tv_sec = i->it_interval.tv_sec;
+	v.it_interval.tv_usec = i->it_interval.tv_nsec / NSEC_PER_USEC;
+	v.it_value.tv_sec = i->it_value.tv_sec;
+	v.it_value.tv_usec = i->it_value.tv_nsec / NSEC_PER_USEC;
+	return copy_to_user(o, &v, sizeof(struct __kernel_old_itimerval)) ? -EFAULT : 0;
+}
+
+
+SYSCALL_DEFINE2(getitimer, int, which, struct __kernel_old_itimerval __user *, value)
+{
+	struct itimerspec64 get_buffer;
+	int error = do_getitimer(which, &get_buffer);
+
+	if (!error && put_itimerval(value, &get_buffer))
+		error = -EFAULT;
 	return error;
 }
 
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
-		       struct compat_itimerval __user *, it)
-{
-	struct itimerval kit;
-	int error = do_getitimer(which, &kit);
+#if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA)
+struct old_itimerval32 {
+	struct old_timeval32	it_interval;
+	struct old_timeval32	it_value;
+};
 
-	if (!error && put_compat_itimerval(it, &kit))
+static int put_old_itimerval32(struct old_itimerval32 __user *o,
+			       const struct itimerspec64 *i)
+{
+	struct old_itimerval32 v32;
+
+	v32.it_interval.tv_sec = i->it_interval.tv_sec;
+	v32.it_interval.tv_usec = i->it_interval.tv_nsec / NSEC_PER_USEC;
+	v32.it_value.tv_sec = i->it_value.tv_sec;
+	v32.it_value.tv_usec = i->it_value.tv_nsec / NSEC_PER_USEC;
+	return copy_to_user(o, &v32, sizeof(struct old_itimerval32)) ? -EFAULT : 0;
+}
+
+COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
+		       struct old_itimerval32 __user *, value)
+{
+	struct itimerspec64 get_buffer;
+	int error = do_getitimer(which, &get_buffer);
+
+	if (!error && put_old_itimerval32(value, &get_buffer))
 		error = -EFAULT;
 	return error;
 }
 #endif
 
-
 /*
  * The timer is automagically restarted, when interval != 0
  */
@@ -141,14 +166,14 @@
 }
 
 static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
-			   const struct itimerval *const value,
-			   struct itimerval *const ovalue)
+			   const struct itimerspec64 *const value,
+			   struct itimerspec64 *const ovalue)
 {
 	u64 oval, nval, ointerval, ninterval;
 	struct cpu_itimer *it = &tsk->signal->it[clock_id];
 
-	nval = ktime_to_ns(timeval_to_ktime(value->it_value));
-	ninterval = ktime_to_ns(timeval_to_ktime(value->it_interval));
+	nval = timespec64_to_ns(&value->it_value);
+	ninterval = timespec64_to_ns(&value->it_interval);
 
 	spin_lock_irq(&tsk->sighand->siglock);
 
@@ -167,8 +192,8 @@
 	spin_unlock_irq(&tsk->sighand->siglock);
 
 	if (ovalue) {
-		ovalue->it_value = ns_to_timeval(oval);
-		ovalue->it_interval = ns_to_timeval(ointerval);
+		ovalue->it_value = ns_to_timespec64(oval);
+		ovalue->it_interval = ns_to_timespec64(ointerval);
 	}
 }
 
@@ -178,19 +203,13 @@
 #define timeval_valid(t) \
 	(((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
 
-int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
+static int do_setitimer(int which, struct itimerspec64 *value,
+			struct itimerspec64 *ovalue)
 {
 	struct task_struct *tsk = current;
 	struct hrtimer *timer;
 	ktime_t expires;
 
-	/*
-	 * Validate the timevals in value.
-	 */
-	if (!timeval_valid(&value->it_value) ||
-	    !timeval_valid(&value->it_interval))
-		return -EINVAL;
-
 	switch (which) {
 	case ITIMER_REAL:
 again:
@@ -199,7 +218,7 @@
 		if (ovalue) {
 			ovalue->it_value = itimer_get_remtime(timer);
 			ovalue->it_interval
-				= ktime_to_timeval(tsk->signal->it_real_incr);
+				= ktime_to_timespec64(tsk->signal->it_real_incr);
 		}
 		/* We are sharing ->siglock with it_real_fn() */
 		if (hrtimer_try_to_cancel(timer) < 0) {
@@ -207,10 +226,10 @@
 			hrtimer_cancel_wait_running(timer);
 			goto again;
 		}
-		expires = timeval_to_ktime(value->it_value);
+		expires = timespec64_to_ktime(value->it_value);
 		if (expires != 0) {
 			tsk->signal->it_real_incr =
-				timeval_to_ktime(value->it_interval);
+				timespec64_to_ktime(value->it_interval);
 			hrtimer_start(timer, expires, HRTIMER_MODE_REL);
 		} else
 			tsk->signal->it_real_incr = 0;
@@ -230,6 +249,17 @@
 	return 0;
 }
 
+#ifdef CONFIG_SECURITY_SELINUX
+void clear_itimer(void)
+{
+	struct itimerspec64 v = {};
+	int i;
+
+	for (i = 0; i < 3; i++)
+		do_setitimer(i, &v, NULL);
+}
+#endif
+
 #ifdef __ARCH_WANT_SYS_ALARM
 
 /**
@@ -246,15 +276,15 @@
  */
 static unsigned int alarm_setitimer(unsigned int seconds)
 {
-	struct itimerval it_new, it_old;
+	struct itimerspec64 it_new, it_old;
 
 #if BITS_PER_LONG < 64
 	if (seconds > INT_MAX)
 		seconds = INT_MAX;
 #endif
 	it_new.it_value.tv_sec = seconds;
-	it_new.it_value.tv_usec = 0;
-	it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
+	it_new.it_value.tv_nsec = 0;
+	it_new.it_interval.tv_sec = it_new.it_interval.tv_nsec = 0;
 
 	do_setitimer(ITIMER_REAL, &it_new, &it_old);
 
@@ -262,8 +292,8 @@
 	 * We can't return 0 if we have an alarm pending ...  And we'd
 	 * better return too much than too little anyway
 	 */
-	if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) ||
-	      it_old.it_value.tv_usec >= 500000)
+	if ((!it_old.it_value.tv_sec && it_old.it_value.tv_nsec) ||
+	      it_old.it_value.tv_nsec >= (NSEC_PER_SEC / 2))
 		it_old.it_value.tv_sec++;
 
 	return it_old.it_value.tv_sec;
@@ -280,15 +310,35 @@
 
 #endif
 
-SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value,
-		struct itimerval __user *, ovalue)
+static int get_itimerval(struct itimerspec64 *o, const struct __kernel_old_itimerval __user *i)
 {
-	struct itimerval set_buffer, get_buffer;
+	struct __kernel_old_itimerval v;
+
+	if (copy_from_user(&v, i, sizeof(struct __kernel_old_itimerval)))
+		return -EFAULT;
+
+	/* Validate the timevals in value. */
+	if (!timeval_valid(&v.it_value) ||
+	    !timeval_valid(&v.it_interval))
+		return -EINVAL;
+
+	o->it_interval.tv_sec = v.it_interval.tv_sec;
+	o->it_interval.tv_nsec = v.it_interval.tv_usec * NSEC_PER_USEC;
+	o->it_value.tv_sec = v.it_value.tv_sec;
+	o->it_value.tv_nsec = v.it_value.tv_usec * NSEC_PER_USEC;
+	return 0;
+}
+
+SYSCALL_DEFINE3(setitimer, int, which, struct __kernel_old_itimerval __user *, value,
+		struct __kernel_old_itimerval __user *, ovalue)
+{
+	struct itimerspec64 set_buffer, get_buffer;
 	int error;
 
 	if (value) {
-		if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
-			return -EFAULT;
+		error = get_itimerval(&set_buffer, value);
+		if (error)
+			return error;
 	} else {
 		memset(&set_buffer, 0, sizeof(set_buffer));
 		printk_once(KERN_WARNING "%s calls setitimer() with new_value NULL pointer."
@@ -300,30 +350,53 @@
 	if (error || !ovalue)
 		return error;
 
-	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
+	if (put_itimerval(ovalue, &get_buffer))
 		return -EFAULT;
 	return 0;
 }
 
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
-		       struct compat_itimerval __user *, in,
-		       struct compat_itimerval __user *, out)
+#if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA)
+static int get_old_itimerval32(struct itimerspec64 *o, const struct old_itimerval32 __user *i)
 {
-	struct itimerval kin, kout;
+	struct old_itimerval32 v32;
+
+	if (copy_from_user(&v32, i, sizeof(struct old_itimerval32)))
+		return -EFAULT;
+
+	/* Validate the timevals in value.  */
+	if (!timeval_valid(&v32.it_value) ||
+	    !timeval_valid(&v32.it_interval))
+		return -EINVAL;
+
+	o->it_interval.tv_sec = v32.it_interval.tv_sec;
+	o->it_interval.tv_nsec = v32.it_interval.tv_usec * NSEC_PER_USEC;
+	o->it_value.tv_sec = v32.it_value.tv_sec;
+	o->it_value.tv_nsec = v32.it_value.tv_usec * NSEC_PER_USEC;
+	return 0;
+}
+
+COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
+		       struct old_itimerval32 __user *, value,
+		       struct old_itimerval32 __user *, ovalue)
+{
+	struct itimerspec64 set_buffer, get_buffer;
 	int error;
 
-	if (in) {
-		if (get_compat_itimerval(&kin, in))
-			return -EFAULT;
+	if (value) {
+		error = get_old_itimerval32(&set_buffer, value);
+		if (error)
+			return error;
 	} else {
-		memset(&kin, 0, sizeof(kin));
+		memset(&set_buffer, 0, sizeof(set_buffer));
+		printk_once(KERN_WARNING "%s calls setitimer() with new_value NULL pointer."
+			    " Misfeature support will be removed\n",
+			    current->comm);
 	}
 
-	error = do_setitimer(which, &kin, out ? &kout : NULL);
-	if (error || !out)
+	error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
+	if (error || !ovalue)
 		return error;
-	if (put_compat_itimerval(out, &kout))
+	if (put_old_itimerval32(ovalue, &get_buffer))
 		return -EFAULT;
 	return 0;
 }
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index d23b434..65409ab 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -49,16 +49,18 @@
  * for "tick-less" systems.
  */
 static struct clocksource clocksource_jiffies = {
-	.name		= "jiffies",
-	.rating		= 1, /* lowest valid rating*/
-	.read		= jiffies_read,
-	.mask		= CLOCKSOURCE_MASK(32),
-	.mult		= TICK_NSEC << JIFFIES_SHIFT, /* details above */
-	.shift		= JIFFIES_SHIFT,
-	.max_cycles	= 10,
+	.name			= "jiffies",
+	.rating			= 1, /* lowest valid rating*/
+	.uncertainty_margin	= 32 * NSEC_PER_MSEC,
+	.read			= jiffies_read,
+	.mask			= CLOCKSOURCE_MASK(32),
+	.mult			= TICK_NSEC << JIFFIES_SHIFT, /* details above */
+	.shift			= JIFFIES_SHIFT,
+	.max_cycles		= 10,
 };
 
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock);
+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock);
+__cacheline_aligned_in_smp seqcount_t jiffies_seq;
 
 #if (BITS_PER_LONG < 64)
 u64 get_jiffies_64(void)
@@ -67,9 +69,9 @@
 	u64 ret;
 
 	do {
-		seq = read_seqbegin(&jiffies_lock);
+		seq = read_seqcount_begin(&jiffies_seq);
 		ret = jiffies_64;
-	} while (read_seqretry(&jiffies_lock, seq));
+	} while (read_seqcount_retry(&jiffies_seq, seq));
 	return ret;
 }
 EXPORT_SYMBOL(get_jiffies_64);
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
new file mode 100644
index 0000000..afc65e6
--- /dev/null
+++ b/kernel/time/namespace.c
@@ -0,0 +1,478 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Andrei Vagin <avagin@openvz.org>
+ * Author: Dmitry Safonov <dima@arista.com>
+ */
+
+#include <linux/time_namespace.h>
+#include <linux/user_namespace.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/task.h>
+#include <linux/clocksource.h>
+#include <linux/seq_file.h>
+#include <linux/proc_ns.h>
+#include <linux/export.h>
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include <linux/err.h>
+#include <linux/mm.h>
+
+#include <vdso/datapage.h>
+
+ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
+				struct timens_offsets *ns_offsets)
+{
+	ktime_t offset;
+
+	switch (clockid) {
+	case CLOCK_MONOTONIC:
+		offset = timespec64_to_ktime(ns_offsets->monotonic);
+		break;
+	case CLOCK_BOOTTIME:
+	case CLOCK_BOOTTIME_ALARM:
+		offset = timespec64_to_ktime(ns_offsets->boottime);
+		break;
+	default:
+		return tim;
+	}
+
+	/*
+	 * Check that @tim value is in [offset, KTIME_MAX + offset]
+	 * and subtract offset.
+	 */
+	if (tim < offset) {
+		/*
+		 * User can specify @tim *absolute* value - if it's lesser than
+		 * the time namespace's offset - it's already expired.
+		 */
+		tim = 0;
+	} else {
+		tim = ktime_sub(tim, offset);
+		if (unlikely(tim > KTIME_MAX))
+			tim = KTIME_MAX;
+	}
+
+	return tim;
+}
+
+static struct ucounts *inc_time_namespaces(struct user_namespace *ns)
+{
+	return inc_ucount(ns, current_euid(), UCOUNT_TIME_NAMESPACES);
+}
+
+static void dec_time_namespaces(struct ucounts *ucounts)
+{
+	dec_ucount(ucounts, UCOUNT_TIME_NAMESPACES);
+}
+
+/**
+ * clone_time_ns - Clone a time namespace
+ * @user_ns:	User namespace which owns a new namespace.
+ * @old_ns:	Namespace to clone
+ *
+ * Clone @old_ns and set the clone refcount to 1
+ *
+ * Return: The new namespace or ERR_PTR.
+ */
+static struct time_namespace *clone_time_ns(struct user_namespace *user_ns,
+					  struct time_namespace *old_ns)
+{
+	struct time_namespace *ns;
+	struct ucounts *ucounts;
+	int err;
+
+	err = -ENOSPC;
+	ucounts = inc_time_namespaces(user_ns);
+	if (!ucounts)
+		goto fail;
+
+	err = -ENOMEM;
+	ns = kmalloc(sizeof(*ns), GFP_KERNEL);
+	if (!ns)
+		goto fail_dec;
+
+	kref_init(&ns->kref);
+
+	ns->vvar_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+	if (!ns->vvar_page)
+		goto fail_free;
+
+	err = ns_alloc_inum(&ns->ns);
+	if (err)
+		goto fail_free_page;
+
+	ns->ucounts = ucounts;
+	ns->ns.ops = &timens_operations;
+	ns->user_ns = get_user_ns(user_ns);
+	ns->offsets = old_ns->offsets;
+	ns->frozen_offsets = false;
+	return ns;
+
+fail_free_page:
+	__free_page(ns->vvar_page);
+fail_free:
+	kfree(ns);
+fail_dec:
+	dec_time_namespaces(ucounts);
+fail:
+	return ERR_PTR(err);
+}
+
+/**
+ * copy_time_ns - Create timens_for_children from @old_ns
+ * @flags:	Cloning flags
+ * @user_ns:	User namespace which owns a new namespace.
+ * @old_ns:	Namespace to clone
+ *
+ * If CLONE_NEWTIME specified in @flags, creates a new timens_for_children;
+ * adds a refcounter to @old_ns otherwise.
+ *
+ * Return: timens_for_children namespace or ERR_PTR.
+ */
+struct time_namespace *copy_time_ns(unsigned long flags,
+	struct user_namespace *user_ns, struct time_namespace *old_ns)
+{
+	if (!(flags & CLONE_NEWTIME))
+		return get_time_ns(old_ns);
+
+	return clone_time_ns(user_ns, old_ns);
+}
+
+static struct timens_offset offset_from_ts(struct timespec64 off)
+{
+	struct timens_offset ret;
+
+	ret.sec = off.tv_sec;
+	ret.nsec = off.tv_nsec;
+
+	return ret;
+}
+
+/*
+ * A time namespace VVAR page has the same layout as the VVAR page which
+ * contains the system wide VDSO data.
+ *
+ * For a normal task the VVAR pages are installed in the normal ordering:
+ *     VVAR
+ *     PVCLOCK
+ *     HVCLOCK
+ *     TIMENS   <- Not really required
+ *
+ * Now for a timens task the pages are installed in the following order:
+ *     TIMENS
+ *     PVCLOCK
+ *     HVCLOCK
+ *     VVAR
+ *
+ * The check for vdso_data->clock_mode is in the unlikely path of
+ * the seq begin magic. So for the non-timens case most of the time
+ * 'seq' is even, so the branch is not taken.
+ *
+ * If 'seq' is odd, i.e. a concurrent update is in progress, the extra check
+ * for vdso_data->clock_mode is a non-issue. The task is spin waiting for the
+ * update to finish and for 'seq' to become even anyway.
+ *
+ * Timens page has vdso_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which
+ * enforces the time namespace handling path.
+ */
+static void timens_setup_vdso_data(struct vdso_data *vdata,
+				   struct time_namespace *ns)
+{
+	struct timens_offset *offset = vdata->offset;
+	struct timens_offset monotonic = offset_from_ts(ns->offsets.monotonic);
+	struct timens_offset boottime = offset_from_ts(ns->offsets.boottime);
+
+	vdata->seq			= 1;
+	vdata->clock_mode		= VDSO_CLOCKMODE_TIMENS;
+	offset[CLOCK_MONOTONIC]		= monotonic;
+	offset[CLOCK_MONOTONIC_RAW]	= monotonic;
+	offset[CLOCK_MONOTONIC_COARSE]	= monotonic;
+	offset[CLOCK_BOOTTIME]		= boottime;
+	offset[CLOCK_BOOTTIME_ALARM]	= boottime;
+}
+
+/*
+ * Protects possibly multiple offsets writers racing each other
+ * and tasks entering the namespace.
+ */
+static DEFINE_MUTEX(offset_lock);
+
+static void timens_set_vvar_page(struct task_struct *task,
+				struct time_namespace *ns)
+{
+	struct vdso_data *vdata;
+	unsigned int i;
+
+	if (ns == &init_time_ns)
+		return;
+
+	/* Fast-path, taken by every task in namespace except the first. */
+	if (likely(ns->frozen_offsets))
+		return;
+
+	mutex_lock(&offset_lock);
+	/* Nothing to-do: vvar_page has been already initialized. */
+	if (ns->frozen_offsets)
+		goto out;
+
+	ns->frozen_offsets = true;
+	vdata = arch_get_vdso_data(page_address(ns->vvar_page));
+
+	for (i = 0; i < CS_BASES; i++)
+		timens_setup_vdso_data(&vdata[i], ns);
+
+out:
+	mutex_unlock(&offset_lock);
+}
+
+void free_time_ns(struct kref *kref)
+{
+	struct time_namespace *ns;
+
+	ns = container_of(kref, struct time_namespace, kref);
+	dec_time_namespaces(ns->ucounts);
+	put_user_ns(ns->user_ns);
+	ns_free_inum(&ns->ns);
+	__free_page(ns->vvar_page);
+	kfree(ns);
+}
+
+static struct time_namespace *to_time_ns(struct ns_common *ns)
+{
+	return container_of(ns, struct time_namespace, ns);
+}
+
+static struct ns_common *timens_get(struct task_struct *task)
+{
+	struct time_namespace *ns = NULL;
+	struct nsproxy *nsproxy;
+
+	task_lock(task);
+	nsproxy = task->nsproxy;
+	if (nsproxy) {
+		ns = nsproxy->time_ns;
+		get_time_ns(ns);
+	}
+	task_unlock(task);
+
+	return ns ? &ns->ns : NULL;
+}
+
+static struct ns_common *timens_for_children_get(struct task_struct *task)
+{
+	struct time_namespace *ns = NULL;
+	struct nsproxy *nsproxy;
+
+	task_lock(task);
+	nsproxy = task->nsproxy;
+	if (nsproxy) {
+		ns = nsproxy->time_ns_for_children;
+		get_time_ns(ns);
+	}
+	task_unlock(task);
+
+	return ns ? &ns->ns : NULL;
+}
+
+static void timens_put(struct ns_common *ns)
+{
+	put_time_ns(to_time_ns(ns));
+}
+
+void timens_commit(struct task_struct *tsk, struct time_namespace *ns)
+{
+	timens_set_vvar_page(tsk, ns);
+	vdso_join_timens(tsk, ns);
+}
+
+static int timens_install(struct nsset *nsset, struct ns_common *new)
+{
+	struct nsproxy *nsproxy = nsset->nsproxy;
+	struct time_namespace *ns = to_time_ns(new);
+
+	if (!current_is_single_threaded())
+		return -EUSERS;
+
+	if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
+	    !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
+		return -EPERM;
+
+	get_time_ns(ns);
+	put_time_ns(nsproxy->time_ns);
+	nsproxy->time_ns = ns;
+
+	get_time_ns(ns);
+	put_time_ns(nsproxy->time_ns_for_children);
+	nsproxy->time_ns_for_children = ns;
+	return 0;
+}
+
+int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk)
+{
+	struct ns_common *nsc = &nsproxy->time_ns_for_children->ns;
+	struct time_namespace *ns = to_time_ns(nsc);
+
+	/* create_new_namespaces() already incremented the ref counter */
+	if (nsproxy->time_ns == nsproxy->time_ns_for_children)
+		return 0;
+
+	get_time_ns(ns);
+	put_time_ns(nsproxy->time_ns);
+	nsproxy->time_ns = ns;
+
+	timens_commit(tsk, ns);
+
+	return 0;
+}
+
+static struct user_namespace *timens_owner(struct ns_common *ns)
+{
+	return to_time_ns(ns)->user_ns;
+}
+
+static void show_offset(struct seq_file *m, int clockid, struct timespec64 *ts)
+{
+	char *clock;
+
+	switch (clockid) {
+	case CLOCK_BOOTTIME:
+		clock = "boottime";
+		break;
+	case CLOCK_MONOTONIC:
+		clock = "monotonic";
+		break;
+	default:
+		clock = "unknown";
+		break;
+	}
+	seq_printf(m, "%-10s %10lld %9ld\n", clock, ts->tv_sec, ts->tv_nsec);
+}
+
+void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m)
+{
+	struct ns_common *ns;
+	struct time_namespace *time_ns;
+
+	ns = timens_for_children_get(p);
+	if (!ns)
+		return;
+	time_ns = to_time_ns(ns);
+
+	show_offset(m, CLOCK_MONOTONIC, &time_ns->offsets.monotonic);
+	show_offset(m, CLOCK_BOOTTIME, &time_ns->offsets.boottime);
+	put_time_ns(time_ns);
+}
+
+int proc_timens_set_offset(struct file *file, struct task_struct *p,
+			   struct proc_timens_offset *offsets, int noffsets)
+{
+	struct ns_common *ns;
+	struct time_namespace *time_ns;
+	struct timespec64 tp;
+	int i, err;
+
+	ns = timens_for_children_get(p);
+	if (!ns)
+		return -ESRCH;
+	time_ns = to_time_ns(ns);
+
+	if (!file_ns_capable(file, time_ns->user_ns, CAP_SYS_TIME)) {
+		put_time_ns(time_ns);
+		return -EPERM;
+	}
+
+	for (i = 0; i < noffsets; i++) {
+		struct proc_timens_offset *off = &offsets[i];
+
+		switch (off->clockid) {
+		case CLOCK_MONOTONIC:
+			ktime_get_ts64(&tp);
+			break;
+		case CLOCK_BOOTTIME:
+			ktime_get_boottime_ts64(&tp);
+			break;
+		default:
+			err = -EINVAL;
+			goto out;
+		}
+
+		err = -ERANGE;
+
+		if (off->val.tv_sec > KTIME_SEC_MAX ||
+		    off->val.tv_sec < -KTIME_SEC_MAX)
+			goto out;
+
+		tp = timespec64_add(tp, off->val);
+		/*
+		 * KTIME_SEC_MAX is divided by 2 to be sure that KTIME_MAX is
+		 * still unreachable.
+		 */
+		if (tp.tv_sec < 0 || tp.tv_sec > KTIME_SEC_MAX / 2)
+			goto out;
+	}
+
+	mutex_lock(&offset_lock);
+	if (time_ns->frozen_offsets) {
+		err = -EACCES;
+		goto out_unlock;
+	}
+
+	err = 0;
+	/* Don't report errors after this line */
+	for (i = 0; i < noffsets; i++) {
+		struct proc_timens_offset *off = &offsets[i];
+		struct timespec64 *offset = NULL;
+
+		switch (off->clockid) {
+		case CLOCK_MONOTONIC:
+			offset = &time_ns->offsets.monotonic;
+			break;
+		case CLOCK_BOOTTIME:
+			offset = &time_ns->offsets.boottime;
+			break;
+		}
+
+		*offset = off->val;
+	}
+
+out_unlock:
+	mutex_unlock(&offset_lock);
+out:
+	put_time_ns(time_ns);
+
+	return err;
+}
+
+const struct proc_ns_operations timens_operations = {
+	.name		= "time",
+	.type		= CLONE_NEWTIME,
+	.get		= timens_get,
+	.put		= timens_put,
+	.install	= timens_install,
+	.owner		= timens_owner,
+};
+
+const struct proc_ns_operations timens_for_children_operations = {
+	.name		= "time_for_children",
+	.real_ns_name	= "time",
+	.type		= CLONE_NEWTIME,
+	.get		= timens_for_children_get,
+	.put		= timens_put,
+	.install	= timens_install,
+	.owner		= timens_owner,
+};
+
+struct time_namespace init_time_ns = {
+	.kref		= KREF_INIT(3),
+	.user_ns	= &init_user_ns,
+	.ns.inum	= PROC_TIME_INIT_INO,
+	.ns.ops		= &timens_operations,
+	.frozen_offsets	= true,
+};
+
+static int __init time_ns_init(void)
+{
+	return 0;
+}
+subsys_initcall(time_ns_init);
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c
index 200fb2d..77c0c23 100644
--- a/kernel/time/posix-clock.c
+++ b/kernel/time/posix-clock.c
@@ -310,8 +310,8 @@
 }
 
 const struct k_clock clock_posix_dynamic = {
-	.clock_getres	= pc_clock_getres,
-	.clock_set	= pc_clock_settime,
-	.clock_get	= pc_clock_gettime,
-	.clock_adj	= pc_clock_adjtime,
+	.clock_getres		= pc_clock_getres,
+	.clock_set		= pc_clock_settime,
+	.clock_get_timespec	= pc_clock_gettime,
+	.clock_adj		= pc_clock_adjtime,
 };
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index eacb0ca..5d76edd 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -47,75 +47,65 @@
 /*
  * Functions for validating access to tasks.
  */
-static struct task_struct *lookup_task(const pid_t pid, bool thread,
-				       bool gettime)
+static struct pid *pid_for_clock(const clockid_t clock, bool gettime)
 {
-	struct task_struct *p;
+	const bool thread = !!CPUCLOCK_PERTHREAD(clock);
+	const pid_t upid = CPUCLOCK_PID(clock);
+	struct pid *pid;
+
+	if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX)
+		return NULL;
 
 	/*
 	 * If the encoded PID is 0, then the timer is targeted at current
 	 * or the process to which current belongs.
 	 */
+	if (upid == 0)
+		return thread ? task_pid(current) : task_tgid(current);
+
+	pid = find_vpid(upid);
 	if (!pid)
-		return thread ? current : current->group_leader;
+		return NULL;
 
-	p = find_task_by_vpid(pid);
-	if (!p)
-		return p;
-
-	if (thread)
-		return same_thread_group(p, current) ? p : NULL;
-
-	if (gettime) {
-		/*
-		 * For clock_gettime(PROCESS) the task does not need to be
-		 * the actual group leader. tsk->sighand gives
-		 * access to the group's clock.
-		 *
-		 * Timers need the group leader because they take a
-		 * reference on it and store the task pointer until the
-		 * timer is destroyed.
-		 */
-		return (p == current || thread_group_leader(p)) ? p : NULL;
+	if (thread) {
+		struct task_struct *tsk = pid_task(pid, PIDTYPE_PID);
+		return (tsk && same_thread_group(tsk, current)) ? pid : NULL;
 	}
 
 	/*
-	 * For processes require that p is group leader.
+	 * For clock_gettime(PROCESS) allow finding the process by
+	 * with the pid of the current task.  The code needs the tgid
+	 * of the process so that pid_task(pid, PIDTYPE_TGID) can be
+	 * used to find the process.
 	 */
-	return has_group_leader_pid(p) ? p : NULL;
-}
+	if (gettime && (pid == task_pid(current)))
+		return task_tgid(current);
 
-static struct task_struct *__get_task_for_clock(const clockid_t clock,
-						bool getref, bool gettime)
-{
-	const bool thread = !!CPUCLOCK_PERTHREAD(clock);
-	const pid_t pid = CPUCLOCK_PID(clock);
-	struct task_struct *p;
-
-	if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX)
-		return NULL;
-
-	rcu_read_lock();
-	p = lookup_task(pid, thread, gettime);
-	if (p && getref)
-		get_task_struct(p);
-	rcu_read_unlock();
-	return p;
-}
-
-static inline struct task_struct *get_task_for_clock(const clockid_t clock)
-{
-	return __get_task_for_clock(clock, true, false);
-}
-
-static inline struct task_struct *get_task_for_clock_get(const clockid_t clock)
-{
-	return __get_task_for_clock(clock, true, true);
+	/*
+	 * For processes require that pid identifies a process.
+	 */
+	return pid_has_task(pid, PIDTYPE_TGID) ? pid : NULL;
 }
 
 static inline int validate_clock_permissions(const clockid_t clock)
 {
-	return __get_task_for_clock(clock, false, false) ? 0 : -EINVAL;
+	int ret;
+
+	rcu_read_lock();
+	ret = pid_for_clock(clock, false) ? 0 : -EINVAL;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static inline enum pid_type clock_pid_type(const clockid_t clock)
+{
+	return CPUCLOCK_PERTHREAD(clock) ? PIDTYPE_PID : PIDTYPE_TGID;
+}
+
+static inline struct task_struct *cpu_timer_task_rcu(struct k_itimer *timer)
+{
+	return pid_task(timer->it.cpu.pid, clock_pid_type(timer->it_clock));
 }
 
 /*
@@ -336,9 +326,7 @@
 /*
  * Sample a process (thread group) clock for the given task clkid. If the
  * group's cputime accounting is already enabled, read the atomic
- * store. Otherwise a full update is required.  Task's sighand lock must be
- * held to protect the task traversal on a full update. clkid is already
- * validated.
+ * store. Otherwise a full update is required.  clkid is already validated.
  */
 static u64 cpu_clock_sample_group(const clockid_t clkid, struct task_struct *p,
 				  bool start)
@@ -365,15 +353,18 @@
 	struct task_struct *tsk;
 	u64 t;
 
-	tsk = get_task_for_clock_get(clock);
-	if (!tsk)
+	rcu_read_lock();
+	tsk = pid_task(pid_for_clock(clock, true), clock_pid_type(clock));
+	if (!tsk) {
+		rcu_read_unlock();
 		return -EINVAL;
+	}
 
 	if (CPUCLOCK_PERTHREAD(clock))
 		t = cpu_clock_sample(clkid, tsk);
 	else
 		t = cpu_clock_sample_group(clkid, tsk, false);
-	put_task_struct(tsk);
+	rcu_read_unlock();
 
 	*tp = ns_to_timespec64(t);
 	return 0;
@@ -386,14 +377,31 @@
  */
 static int posix_cpu_timer_create(struct k_itimer *new_timer)
 {
-	struct task_struct *p = get_task_for_clock(new_timer->it_clock);
+	static struct lock_class_key posix_cpu_timers_key;
+	struct pid *pid;
 
-	if (!p)
+	rcu_read_lock();
+	pid = pid_for_clock(new_timer->it_clock, false);
+	if (!pid) {
+		rcu_read_unlock();
 		return -EINVAL;
+	}
+
+	/*
+	 * If posix timer expiry is handled in task work context then
+	 * timer::it_lock can be taken without disabling interrupts as all
+	 * other locking happens in task context. This requires a seperate
+	 * lock class key otherwise regular posix timer expiry would record
+	 * the lock class being taken in interrupt context and generate a
+	 * false positive warning.
+	 */
+	if (IS_ENABLED(CONFIG_POSIX_CPU_TIMERS_TASK_WORK))
+		lockdep_set_class(&new_timer->it_lock, &posix_cpu_timers_key);
 
 	new_timer->kclock = &clock_posix_cpu;
 	timerqueue_init(&new_timer->it.cpu.node);
-	new_timer->it.cpu.task = p;
+	new_timer->it.cpu.pid = get_pid(pid);
+	rcu_read_unlock();
 	return 0;
 }
 
@@ -406,13 +414,15 @@
 static int posix_cpu_timer_del(struct k_itimer *timer)
 {
 	struct cpu_timer *ctmr = &timer->it.cpu;
-	struct task_struct *p = ctmr->task;
 	struct sighand_struct *sighand;
+	struct task_struct *p;
 	unsigned long flags;
 	int ret = 0;
 
-	if (WARN_ON_ONCE(!p))
-		return -EINVAL;
+	rcu_read_lock();
+	p = cpu_timer_task_rcu(timer);
+	if (!p)
+		goto out;
 
 	/*
 	 * Protect against sighand release/switch in exit/exec and process/
@@ -434,8 +444,10 @@
 		unlock_task_sighand(p, &flags);
 	}
 
+out:
+	rcu_read_unlock();
 	if (!ret)
-		put_task_struct(p);
+		put_pid(ctmr->pid);
 
 	return ret;
 }
@@ -484,12 +496,11 @@
  * Insert the timer on the appropriate list before any timers that
  * expire later.  This must be called with the sighand lock held.
  */
-static void arm_timer(struct k_itimer *timer)
+static void arm_timer(struct k_itimer *timer, struct task_struct *p)
 {
 	int clkidx = CPUCLOCK_WHICH(timer->it_clock);
 	struct cpu_timer *ctmr = &timer->it.cpu;
 	u64 newexp = cpu_timer_getexpires(ctmr);
-	struct task_struct *p = ctmr->task;
 	struct posix_cputimer_base *base;
 
 	if (CPUCLOCK_PERTHREAD(timer->it_clock))
@@ -564,13 +575,21 @@
 	clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
 	u64 old_expires, new_expires, old_incr, val;
 	struct cpu_timer *ctmr = &timer->it.cpu;
-	struct task_struct *p = ctmr->task;
 	struct sighand_struct *sighand;
+	struct task_struct *p;
 	unsigned long flags;
 	int ret = 0;
 
-	if (WARN_ON_ONCE(!p))
-		return -EINVAL;
+	rcu_read_lock();
+	p = cpu_timer_task_rcu(timer);
+	if (!p) {
+		/*
+		 * If p has just been reaped, we can no
+		 * longer get any information about it at all.
+		 */
+		rcu_read_unlock();
+		return -ESRCH;
+	}
 
 	/*
 	 * Use the to_ktime conversion because that clamps the maximum
@@ -587,8 +606,10 @@
 	 * If p has just been reaped, we can no
 	 * longer get any information about it at all.
 	 */
-	if (unlikely(sighand == NULL))
+	if (unlikely(sighand == NULL)) {
+		rcu_read_unlock();
 		return -ESRCH;
+	}
 
 	/*
 	 * Disarm any old timer after extracting its expiry time.
@@ -662,7 +683,7 @@
 	 */
 	cpu_timer_setexpires(ctmr, new_expires);
 	if (new_expires != 0 && val < new_expires) {
-		arm_timer(timer);
+		arm_timer(timer, p);
 	}
 
 	unlock_task_sighand(p, &flags);
@@ -693,6 +714,7 @@
 
 	ret = 0;
  out:
+	rcu_read_unlock();
 	if (old)
 		old->it_interval = ns_to_timespec64(old_incr);
 
@@ -704,10 +726,12 @@
 	clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
 	struct cpu_timer *ctmr = &timer->it.cpu;
 	u64 now, expires = cpu_timer_getexpires(ctmr);
-	struct task_struct *p = ctmr->task;
+	struct task_struct *p;
 
-	if (WARN_ON_ONCE(!p))
-		return;
+	rcu_read_lock();
+	p = cpu_timer_task_rcu(timer);
+	if (!p)
+		goto out;
 
 	/*
 	 * Easy part: convert the reload time.
@@ -715,36 +739,15 @@
 	itp->it_interval = ktime_to_timespec64(timer->it_interval);
 
 	if (!expires)
-		return;
+		goto out;
 
 	/*
 	 * Sample the clock to take the difference with the expiry time.
 	 */
-	if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+	if (CPUCLOCK_PERTHREAD(timer->it_clock))
 		now = cpu_clock_sample(clkid, p);
-	} else {
-		struct sighand_struct *sighand;
-		unsigned long flags;
-
-		/*
-		 * Protect against sighand release/switch in exit/exec and
-		 * also make timer sampling safe if it ends up calling
-		 * thread_group_cputime().
-		 */
-		sighand = lock_task_sighand(p, &flags);
-		if (unlikely(sighand == NULL)) {
-			/*
-			 * The process has been reaped.
-			 * We can't even collect a sample any more.
-			 * Disarm the timer, nothing else to do.
-			 */
-			cpu_timer_setexpires(ctmr, 0);
-			return;
-		} else {
-			now = cpu_clock_sample_group(clkid, p, false);
-			unlock_task_sighand(p, &flags);
-		}
-	}
+	else
+		now = cpu_clock_sample_group(clkid, p, false);
 
 	if (now < expires) {
 		itp->it_value = ns_to_timespec64(expires - now);
@@ -756,6 +759,8 @@
 		itp->it_value.tv_nsec = 1;
 		itp->it_value.tv_sec = 0;
 	}
+out:
+	rcu_read_unlock();
 }
 
 #define MAX_COLLECTED	20
@@ -976,56 +981,38 @@
 static void posix_cpu_timer_rearm(struct k_itimer *timer)
 {
 	clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
-	struct cpu_timer *ctmr = &timer->it.cpu;
-	struct task_struct *p = ctmr->task;
+	struct task_struct *p;
 	struct sighand_struct *sighand;
 	unsigned long flags;
 	u64 now;
 
-	if (WARN_ON_ONCE(!p))
-		return;
+	rcu_read_lock();
+	p = cpu_timer_task_rcu(timer);
+	if (!p)
+		goto out;
+
+	/* Protect timer list r/w in arm_timer() */
+	sighand = lock_task_sighand(p, &flags);
+	if (unlikely(sighand == NULL))
+		goto out;
 
 	/*
 	 * Fetch the current sample and update the timer's expiry time.
 	 */
-	if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+	if (CPUCLOCK_PERTHREAD(timer->it_clock))
 		now = cpu_clock_sample(clkid, p);
-		bump_cpu_timer(timer, now);
-		if (unlikely(p->exit_state))
-			return;
-
-		/* Protect timer list r/w in arm_timer() */
-		sighand = lock_task_sighand(p, &flags);
-		if (!sighand)
-			return;
-	} else {
-		/*
-		 * Protect arm_timer() and timer sampling in case of call to
-		 * thread_group_cputime().
-		 */
-		sighand = lock_task_sighand(p, &flags);
-		if (unlikely(sighand == NULL)) {
-			/*
-			 * The process has been reaped.
-			 * We can't even collect a sample any more.
-			 */
-			cpu_timer_setexpires(ctmr, 0);
-			return;
-		} else if (unlikely(p->exit_state) && thread_group_empty(p)) {
-			/* If the process is dying, no need to rearm */
-			goto unlock;
-		}
+	else
 		now = cpu_clock_sample_group(clkid, p, true);
-		bump_cpu_timer(timer, now);
-		/* Leave the sighand locked for the call below.  */
-	}
+
+	bump_cpu_timer(timer, now);
 
 	/*
 	 * Now re-arm for the new expiry time.
 	 */
-	arm_timer(timer);
-unlock:
+	arm_timer(timer, p);
 	unlock_task_sighand(p, &flags);
+out:
+	rcu_read_unlock();
 }
 
 /**
@@ -1105,40 +1092,178 @@
 	return false;
 }
 
-/*
- * This is called from the timer interrupt handler.  The irq handler has
- * already updated our counts.  We need to check if any timers fire now.
- * Interrupts are disabled.
- */
-void run_posix_cpu_timers(void)
-{
-	struct task_struct *tsk = current;
-	struct k_itimer *timer, *next;
-	unsigned long flags;
-	LIST_HEAD(firing);
+static void handle_posix_cpu_timers(struct task_struct *tsk);
 
-	lockdep_assert_irqs_disabled();
+#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
+static void posix_cpu_timers_work(struct callback_head *work)
+{
+	handle_posix_cpu_timers(current);
+}
+
+/*
+ * Clear existing posix CPU timers task work.
+ */
+void clear_posix_cputimers_work(struct task_struct *p)
+{
+	/*
+	 * A copied work entry from the old task is not meaningful, clear it.
+	 * N.B. init_task_work will not do this.
+	 */
+	memset(&p->posix_cputimers_work.work, 0,
+	       sizeof(p->posix_cputimers_work.work));
+	init_task_work(&p->posix_cputimers_work.work,
+		       posix_cpu_timers_work);
+	p->posix_cputimers_work.scheduled = false;
+}
+
+/*
+ * Initialize posix CPU timers task work in init task. Out of line to
+ * keep the callback static and to avoid header recursion hell.
+ */
+void __init posix_cputimers_init_work(void)
+{
+	clear_posix_cputimers_work(current);
+}
+
+/*
+ * Note: All operations on tsk->posix_cputimer_work.scheduled happen either
+ * in hard interrupt context or in task context with interrupts
+ * disabled. Aside of that the writer/reader interaction is always in the
+ * context of the current task, which means they are strict per CPU.
+ */
+static inline bool posix_cpu_timers_work_scheduled(struct task_struct *tsk)
+{
+	return tsk->posix_cputimers_work.scheduled;
+}
+
+static inline void __run_posix_cpu_timers(struct task_struct *tsk)
+{
+	if (WARN_ON_ONCE(tsk->posix_cputimers_work.scheduled))
+		return;
+
+	/* Schedule task work to actually expire the timers */
+	tsk->posix_cputimers_work.scheduled = true;
+	task_work_add(tsk, &tsk->posix_cputimers_work.work, TWA_RESUME);
+}
+
+static inline bool posix_cpu_timers_enable_work(struct task_struct *tsk,
+						unsigned long start)
+{
+	bool ret = true;
 
 	/*
-	 * The fast path checks that there are no expired thread or thread
-	 * group timers.  If that's so, just return.
+	 * On !RT kernels interrupts are disabled while collecting expired
+	 * timers, so no tick can happen and the fast path check can be
+	 * reenabled without further checks.
 	 */
-	if (!fastpath_timer_check(tsk))
-		return;
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		tsk->posix_cputimers_work.scheduled = false;
+		return true;
+	}
+
+	/*
+	 * On RT enabled kernels ticks can happen while the expired timers
+	 * are collected under sighand lock. But any tick which observes
+	 * the CPUTIMERS_WORK_SCHEDULED bit set, does not run the fastpath
+	 * checks. So reenabling the tick work has do be done carefully:
+	 *
+	 * Disable interrupts and run the fast path check if jiffies have
+	 * advanced since the collecting of expired timers started. If
+	 * jiffies have not advanced or the fast path check did not find
+	 * newly expired timers, reenable the fast path check in the timer
+	 * interrupt. If there are newly expired timers, return false and
+	 * let the collection loop repeat.
+	 */
+	local_irq_disable();
+	if (start != jiffies && fastpath_timer_check(tsk))
+		ret = false;
+	else
+		tsk->posix_cputimers_work.scheduled = false;
+	local_irq_enable();
+
+	return ret;
+}
+#else /* CONFIG_POSIX_CPU_TIMERS_TASK_WORK */
+static inline void __run_posix_cpu_timers(struct task_struct *tsk)
+{
+	lockdep_posixtimer_enter();
+	handle_posix_cpu_timers(tsk);
+	lockdep_posixtimer_exit();
+}
+
+static inline bool posix_cpu_timers_work_scheduled(struct task_struct *tsk)
+{
+	return false;
+}
+
+static inline bool posix_cpu_timers_enable_work(struct task_struct *tsk,
+						unsigned long start)
+{
+	return true;
+}
+#endif /* CONFIG_POSIX_CPU_TIMERS_TASK_WORK */
+
+static void handle_posix_cpu_timers(struct task_struct *tsk)
+{
+	struct k_itimer *timer, *next;
+	unsigned long flags, start;
+	LIST_HEAD(firing);
 
 	if (!lock_task_sighand(tsk, &flags))
 		return;
-	/*
-	 * Here we take off tsk->signal->cpu_timers[N] and
-	 * tsk->cpu_timers[N] all the timers that are firing, and
-	 * put them on the firing list.
-	 */
-	check_thread_timers(tsk, &firing);
 
-	check_process_timers(tsk, &firing);
+	do {
+		/*
+		 * On RT locking sighand lock does not disable interrupts,
+		 * so this needs to be careful vs. ticks. Store the current
+		 * jiffies value.
+		 */
+		start = READ_ONCE(jiffies);
+		barrier();
+
+		/*
+		 * Here we take off tsk->signal->cpu_timers[N] and
+		 * tsk->cpu_timers[N] all the timers that are firing, and
+		 * put them on the firing list.
+		 */
+		check_thread_timers(tsk, &firing);
+
+		check_process_timers(tsk, &firing);
+
+		/*
+		 * The above timer checks have updated the exipry cache and
+		 * because nothing can have queued or modified timers after
+		 * sighand lock was taken above it is guaranteed to be
+		 * consistent. So the next timer interrupt fastpath check
+		 * will find valid data.
+		 *
+		 * If timer expiry runs in the timer interrupt context then
+		 * the loop is not relevant as timers will be directly
+		 * expired in interrupt context. The stub function below
+		 * returns always true which allows the compiler to
+		 * optimize the loop out.
+		 *
+		 * If timer expiry is deferred to task work context then
+		 * the following rules apply:
+		 *
+		 * - On !RT kernels no tick can have happened on this CPU
+		 *   after sighand lock was acquired because interrupts are
+		 *   disabled. So reenabling task work before dropping
+		 *   sighand lock and reenabling interrupts is race free.
+		 *
+		 * - On RT kernels ticks might have happened but the tick
+		 *   work ignored posix CPU timer handling because the
+		 *   CPUTIMERS_WORK_SCHEDULED bit is set. Reenabling work
+		 *   must be done very carefully including a check whether
+		 *   ticks have happened since the start of the timer
+		 *   expiry checks. posix_cpu_timers_enable_work() takes
+		 *   care of that and eventually lets the expiry checks
+		 *   run again.
+		 */
+	} while (!posix_cpu_timers_enable_work(tsk, start));
 
 	/*
-	 * We must release these locks before taking any timer's lock.
+	 * We must release sighand lock before taking any timer's lock.
 	 * There is a potential race with timer deletion here, as the
 	 * siglock now protects our private firing list.  We have set
 	 * the firing flag in each timer, so that a deletion attempt
@@ -1156,6 +1281,13 @@
 	list_for_each_entry_safe(timer, next, &firing, it.cpu.elist) {
 		int cpu_firing;
 
+		/*
+		 * spin_lock() is sufficient here even independent of the
+		 * expiry context. If expiry happens in hard interrupt
+		 * context it's obvious. For task work context it's safe
+		 * because all other operations on timer::it_lock happen in
+		 * task context (syscall or exit).
+		 */
 		spin_lock(&timer->it_lock);
 		list_del_init(&timer->it.cpu.elist);
 		cpu_firing = timer->it.cpu.firing;
@@ -1172,6 +1304,34 @@
 }
 
 /*
+ * This is called from the timer interrupt handler.  The irq handler has
+ * already updated our counts.  We need to check if any timers fire now.
+ * Interrupts are disabled.
+ */
+void run_posix_cpu_timers(void)
+{
+	struct task_struct *tsk = current;
+
+	lockdep_assert_irqs_disabled();
+
+	/*
+	 * If the actual expiry is deferred to task work context and the
+	 * work is already scheduled there is no point to do anything here.
+	 */
+	if (posix_cpu_timers_work_scheduled(tsk))
+		return;
+
+	/*
+	 * The fast path checks that there are no expired thread or thread
+	 * group timers.  If that's so, just return.
+	 */
+	if (!fastpath_timer_check(tsk))
+		return;
+
+	__run_posix_cpu_timers(tsk);
+}
+
+/*
  * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
  * The tsk->sighand->siglock must be held by the caller.
  */
@@ -1391,26 +1551,26 @@
 }
 
 const struct k_clock clock_posix_cpu = {
-	.clock_getres	= posix_cpu_clock_getres,
-	.clock_set	= posix_cpu_clock_set,
-	.clock_get	= posix_cpu_clock_get,
-	.timer_create	= posix_cpu_timer_create,
-	.nsleep		= posix_cpu_nsleep,
-	.timer_set	= posix_cpu_timer_set,
-	.timer_del	= posix_cpu_timer_del,
-	.timer_get	= posix_cpu_timer_get,
-	.timer_rearm	= posix_cpu_timer_rearm,
+	.clock_getres		= posix_cpu_clock_getres,
+	.clock_set		= posix_cpu_clock_set,
+	.clock_get_timespec	= posix_cpu_clock_get,
+	.timer_create		= posix_cpu_timer_create,
+	.nsleep			= posix_cpu_nsleep,
+	.timer_set		= posix_cpu_timer_set,
+	.timer_del		= posix_cpu_timer_del,
+	.timer_get		= posix_cpu_timer_get,
+	.timer_rearm		= posix_cpu_timer_rearm,
 };
 
 const struct k_clock clock_process = {
-	.clock_getres	= process_cpu_clock_getres,
-	.clock_get	= process_cpu_clock_get,
-	.timer_create	= process_cpu_timer_create,
-	.nsleep		= process_cpu_nsleep,
+	.clock_getres		= process_cpu_clock_getres,
+	.clock_get_timespec	= process_cpu_clock_get,
+	.timer_create		= process_cpu_timer_create,
+	.nsleep			= process_cpu_nsleep,
 };
 
 const struct k_clock clock_thread = {
-	.clock_getres	= thread_cpu_clock_getres,
-	.clock_get	= thread_cpu_clock_get,
-	.timer_create	= thread_cpu_timer_create,
+	.clock_getres		= thread_cpu_clock_getres,
+	.clock_get_timespec	= thread_cpu_clock_get,
+	.timer_create		= thread_cpu_timer_create,
 };
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 67df65f..fcb3b21 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -14,6 +14,7 @@
 #include <linux/ktime.h>
 #include <linux/timekeeping.h>
 #include <linux/posix-timers.h>
+#include <linux/time_namespace.h>
 #include <linux/compat.h>
 
 #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
@@ -77,9 +78,11 @@
 		break;
 	case CLOCK_MONOTONIC:
 		ktime_get_ts64(tp);
+		timens_add_monotonic(tp);
 		break;
 	case CLOCK_BOOTTIME:
 		ktime_get_boottime_ts64(tp);
+		timens_add_boottime(tp);
 		break;
 	default:
 		return -EINVAL;
@@ -126,6 +129,7 @@
 		struct __kernel_timespec __user *, rmtp)
 {
 	struct timespec64 t;
+	ktime_t texp;
 
 	switch (which_clock) {
 	case CLOCK_REALTIME:
@@ -144,13 +148,19 @@
 		rmtp = NULL;
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
-	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
+	texp = timespec64_to_ktime(t);
+	if (flags & TIMER_ABSTIME)
+		texp = timens_ktime_to_host(which_clock, texp);
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 				 which_clock);
 }
 
 #ifdef CONFIG_COMPAT
 COMPAT_SYS_NI(timer_create);
+#endif
+
+#if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA)
 COMPAT_SYS_NI(getitimer);
 COMPAT_SYS_NI(setitimer);
 #endif
@@ -212,6 +222,7 @@
 		struct old_timespec32 __user *, rmtp)
 {
 	struct timespec64 t;
+	ktime_t texp;
 
 	switch (which_clock) {
 	case CLOCK_REALTIME:
@@ -230,7 +241,10 @@
 		rmtp = NULL;
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
-	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
+	texp = timespec64_to_ktime(t);
+	if (flags & TIMER_ABSTIME)
+		texp = timens_ktime_to_host(which_clock, texp);
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 				 which_clock);
 }
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 97d4a9d..dd5697d 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -30,6 +30,7 @@
 #include <linux/hashtable.h>
 #include <linux/compat.h>
 #include <linux/nospec.h>
+#include <linux/time_namespace.h>
 
 #include "timekeeping.h"
 #include "posix-timers.h"
@@ -120,7 +121,8 @@
 {
 	struct k_itimer *timer;
 
-	hlist_for_each_entry_rcu(timer, head, t_hash) {
+	hlist_for_each_entry_rcu(timer, head, t_hash,
+				 lockdep_is_held(&hash_lock)) {
 		if ((timer->it_signal == sig) && (timer->it_id == id))
 			return timer;
 	}
@@ -165,12 +167,17 @@
 }
 
 /* Get clock_realtime */
-static int posix_clock_realtime_get(clockid_t which_clock, struct timespec64 *tp)
+static int posix_get_realtime_timespec(clockid_t which_clock, struct timespec64 *tp)
 {
 	ktime_get_real_ts64(tp);
 	return 0;
 }
 
+static ktime_t posix_get_realtime_ktime(clockid_t which_clock)
+{
+	return ktime_get_real();
+}
+
 /* Set clock_realtime */
 static int posix_clock_realtime_set(const clockid_t which_clock,
 				    const struct timespec64 *tp)
@@ -187,18 +194,25 @@
 /*
  * Get monotonic time for posix timers
  */
-static int posix_ktime_get_ts(clockid_t which_clock, struct timespec64 *tp)
+static int posix_get_monotonic_timespec(clockid_t which_clock, struct timespec64 *tp)
 {
 	ktime_get_ts64(tp);
+	timens_add_monotonic(tp);
 	return 0;
 }
 
+static ktime_t posix_get_monotonic_ktime(clockid_t which_clock)
+{
+	return ktime_get();
+}
+
 /*
  * Get monotonic-raw time for posix timers
  */
 static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp)
 {
 	ktime_get_raw_ts64(tp);
+	timens_add_monotonic(tp);
 	return 0;
 }
 
@@ -213,6 +227,7 @@
 						struct timespec64 *tp)
 {
 	ktime_get_coarse_ts64(tp);
+	timens_add_monotonic(tp);
 	return 0;
 }
 
@@ -222,18 +237,29 @@
 	return 0;
 }
 
-static int posix_get_boottime(const clockid_t which_clock, struct timespec64 *tp)
+static int posix_get_boottime_timespec(const clockid_t which_clock, struct timespec64 *tp)
 {
 	ktime_get_boottime_ts64(tp);
+	timens_add_boottime(tp);
 	return 0;
 }
 
-static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp)
+static ktime_t posix_get_boottime_ktime(const clockid_t which_clock)
+{
+	return ktime_get_boottime();
+}
+
+static int posix_get_tai_timespec(clockid_t which_clock, struct timespec64 *tp)
 {
 	ktime_get_clocktai_ts64(tp);
 	return 0;
 }
 
+static ktime_t posix_get_tai_ktime(clockid_t which_clock)
+{
+	return ktime_get_clocktai();
+}
+
 static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
 {
 	tp->tv_sec = 0;
@@ -413,12 +439,12 @@
 		rtn = pid_task(pid, PIDTYPE_PID);
 		if (!rtn || !same_thread_group(rtn, current))
 			return NULL;
-		/* FALLTHRU */
+		fallthrough;
 	case SIGEV_SIGNAL:
 	case SIGEV_THREAD:
 		if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
 			return NULL;
-		/* FALLTHRU */
+		fallthrough;
 	case SIGEV_NONE:
 		return pid;
 	default:
@@ -645,7 +671,6 @@
 {
 	const struct k_clock *kc = timr->kclock;
 	ktime_t now, remaining, iv;
-	struct timespec64 ts64;
 	bool sig_none;
 
 	sig_none = timr->it_sigev_notify == SIGEV_NONE;
@@ -663,12 +688,7 @@
 			return;
 	}
 
-	/*
-	 * The timespec64 based conversion is suboptimal, but it's not
-	 * worth to implement yet another callback.
-	 */
-	kc->clock_get(timr->it_clock, &ts64);
-	now = timespec64_to_ktime(ts64);
+	now = kc->clock_get_ktime(timr->it_clock);
 
 	/*
 	 * When a requeue is pending or this is a SIGEV_NONE timer move the
@@ -781,7 +801,7 @@
 	 * Posix magic: Relative CLOCK_REALTIME timers are not affected by
 	 * clock modifications, so they become CLOCK_MONOTONIC based under the
 	 * hood. See hrtimer_init(). Update timr->kclock, so the generic
-	 * functions which use timr->kclock->clock_get() work.
+	 * functions which use timr->kclock->clock_get_*() work.
 	 *
 	 * Note: it_clock stays unmodified, because the next timer_set() might
 	 * use ABSTIME, so it needs to switch back.
@@ -866,6 +886,8 @@
 
 	timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
 	expires = timespec64_to_ktime(new_setting->it_value);
+	if (flags & TIMER_ABSTIME)
+		expires = timens_ktime_to_host(timr->it_clock, expires);
 	sigev_none = timr->it_sigev_notify == SIGEV_NONE;
 
 	kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
@@ -1067,7 +1089,7 @@
 	if (!kc)
 		return -EINVAL;
 
-	error = kc->clock_get(which_clock, &kernel_tp);
+	error = kc->clock_get_timespec(which_clock, &kernel_tp);
 
 	if (!error && put_timespec64(&kernel_tp, tp))
 		error = -EFAULT;
@@ -1149,7 +1171,7 @@
 	if (!kc)
 		return -EINVAL;
 
-	err = kc->clock_get(which_clock, &ts);
+	err = kc->clock_get_timespec(which_clock, &ts);
 
 	if (!err && put_old_timespec32(&ts, tp))
 		err = -EFAULT;
@@ -1200,7 +1222,22 @@
 static int common_nsleep(const clockid_t which_clock, int flags,
 			 const struct timespec64 *rqtp)
 {
-	return hrtimer_nanosleep(rqtp, flags & TIMER_ABSTIME ?
+	ktime_t texp = timespec64_to_ktime(*rqtp);
+
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
+				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+				 which_clock);
+}
+
+static int common_nsleep_timens(const clockid_t which_clock, int flags,
+			 const struct timespec64 *rqtp)
+{
+	ktime_t texp = timespec64_to_ktime(*rqtp);
+
+	if (flags & TIMER_ABSTIME)
+		texp = timens_ktime_to_host(which_clock, texp);
+
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 				 which_clock);
 }
@@ -1261,7 +1298,8 @@
 
 static const struct k_clock clock_realtime = {
 	.clock_getres		= posix_get_hrtimer_res,
-	.clock_get		= posix_clock_realtime_get,
+	.clock_get_timespec	= posix_get_realtime_timespec,
+	.clock_get_ktime	= posix_get_realtime_ktime,
 	.clock_set		= posix_clock_realtime_set,
 	.clock_adj		= posix_clock_realtime_adj,
 	.nsleep			= common_nsleep,
@@ -1279,8 +1317,9 @@
 
 static const struct k_clock clock_monotonic = {
 	.clock_getres		= posix_get_hrtimer_res,
-	.clock_get		= posix_ktime_get_ts,
-	.nsleep			= common_nsleep,
+	.clock_get_timespec	= posix_get_monotonic_timespec,
+	.clock_get_ktime	= posix_get_monotonic_ktime,
+	.nsleep			= common_nsleep_timens,
 	.timer_create		= common_timer_create,
 	.timer_set		= common_timer_set,
 	.timer_get		= common_timer_get,
@@ -1295,22 +1334,23 @@
 
 static const struct k_clock clock_monotonic_raw = {
 	.clock_getres		= posix_get_hrtimer_res,
-	.clock_get		= posix_get_monotonic_raw,
+	.clock_get_timespec	= posix_get_monotonic_raw,
 };
 
 static const struct k_clock clock_realtime_coarse = {
 	.clock_getres		= posix_get_coarse_res,
-	.clock_get		= posix_get_realtime_coarse,
+	.clock_get_timespec	= posix_get_realtime_coarse,
 };
 
 static const struct k_clock clock_monotonic_coarse = {
 	.clock_getres		= posix_get_coarse_res,
-	.clock_get		= posix_get_monotonic_coarse,
+	.clock_get_timespec	= posix_get_monotonic_coarse,
 };
 
 static const struct k_clock clock_tai = {
 	.clock_getres		= posix_get_hrtimer_res,
-	.clock_get		= posix_get_tai,
+	.clock_get_ktime	= posix_get_tai_ktime,
+	.clock_get_timespec	= posix_get_tai_timespec,
 	.nsleep			= common_nsleep,
 	.timer_create		= common_timer_create,
 	.timer_set		= common_timer_set,
@@ -1326,8 +1366,9 @@
 
 static const struct k_clock clock_boottime = {
 	.clock_getres		= posix_get_hrtimer_res,
-	.clock_get		= posix_get_boottime,
-	.nsleep			= common_nsleep,
+	.clock_get_ktime	= posix_get_boottime_ktime,
+	.clock_get_timespec	= posix_get_boottime_timespec,
+	.nsleep			= common_nsleep_timens,
 	.timer_create		= common_timer_create,
 	.timer_set		= common_timer_set,
 	.timer_get		= common_timer_get,
diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h
index 897c29e..f32a2eb 100644
--- a/kernel/time/posix-timers.h
+++ b/kernel/time/posix-timers.h
@@ -6,8 +6,11 @@
 				struct timespec64 *tp);
 	int	(*clock_set)(const clockid_t which_clock,
 			     const struct timespec64 *tp);
-	int	(*clock_get)(const clockid_t which_clock,
-			     struct timespec64 *tp);
+	/* Returns the clock value in the current time namespace. */
+	int	(*clock_get_timespec)(const clockid_t which_clock,
+				      struct timespec64 *tp);
+	/* Returns the clock value in the root time namespace. */
+	ktime_t	(*clock_get_ktime)(const clockid_t which_clock);
 	int	(*clock_adj)(const clockid_t which_clock, struct __kernel_timex *tx);
 	int	(*timer_create)(struct k_itimer *timer);
 	int	(*nsleep)(const clockid_t which_clock, int flags,
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index a5538dd..b1b9b12 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -20,31 +20,6 @@
 #include "timekeeping.h"
 
 /**
- * struct clock_read_data - data required to read from sched_clock()
- *
- * @epoch_ns:		sched_clock() value at last update
- * @epoch_cyc:		Clock cycle value at last update.
- * @sched_clock_mask:   Bitmask for two's complement subtraction of non 64bit
- *			clocks.
- * @read_sched_clock:	Current clock source (or dummy source when suspended).
- * @mult:		Multipler for scaled math conversion.
- * @shift:		Shift value for scaled math conversion.
- *
- * Care must be taken when updating this structure; it is read by
- * some very hot code paths. It occupies <=40 bytes and, when combined
- * with the seqcount used to synchronize access, comfortably fits into
- * a 64 byte cache line.
- */
-struct clock_read_data {
-	u64 epoch_ns;
-	u64 epoch_cyc;
-	u64 sched_clock_mask;
-	u64 (*read_sched_clock)(void);
-	u32 mult;
-	u32 shift;
-};
-
-/**
  * struct clock_data - all data needed for sched_clock() (including
  *                     registration of a new clock source)
  *
@@ -60,7 +35,7 @@
  * into a single 64-byte cache line.
  */
 struct clock_data {
-	seqcount_t		seq;
+	seqcount_latch_t	seq;
 	struct clock_read_data	read_data[2];
 	ktime_t			wrap_kt;
 	unsigned long		rate;
@@ -93,6 +68,17 @@
 	return (cyc * mult) >> shift;
 }
 
+notrace struct clock_read_data *sched_clock_read_begin(unsigned int *seq)
+{
+	*seq = raw_read_seqcount_latch(&cd.seq);
+	return cd.read_data + (*seq & 1);
+}
+
+notrace int sched_clock_read_retry(unsigned int seq)
+{
+	return read_seqcount_latch_retry(&cd.seq, seq);
+}
+
 unsigned long long notrace sched_clock(void)
 {
 	u64 cyc, res;
@@ -100,13 +86,12 @@
 	struct clock_read_data *rd;
 
 	do {
-		seq = raw_read_seqcount(&cd.seq);
-		rd = cd.read_data + (seq & 1);
+		rd = sched_clock_read_begin(&seq);
 
 		cyc = (rd->read_sched_clock() - rd->epoch_cyc) &
 		      rd->sched_clock_mask;
 		res = rd->epoch_ns + cyc_to_ns(cyc, rd->mult, rd->shift);
-	} while (read_seqcount_retry(&cd.seq, seq));
+	} while (sched_clock_read_retry(seq));
 
 	return res;
 }
@@ -169,14 +154,15 @@
 {
 	u64 res, wrap, new_mask, new_epoch, cyc, ns;
 	u32 new_mult, new_shift;
-	unsigned long r;
+	unsigned long r, flags;
 	char r_unit;
 	struct clock_read_data rd;
 
 	if (cd.rate > rate)
 		return;
 
-	WARN_ON(!irqs_disabled());
+	/* Cannot register a sched_clock with interrupts on */
+	local_irq_save(flags);
 
 	/* Calculate the mult/shift to convert counter ticks to ns. */
 	clocks_calc_mult_shift(&new_mult, &new_shift, rate, NSEC_PER_SEC, 3600);
@@ -234,6 +220,8 @@
 	if (irqtime > 0 || (irqtime == -1 && rate >= 1000000))
 		enable_sched_clock_irqtime();
 
+	local_irq_restore(flags);
+
 	pr_debug("Registered %pS as sched_clock source\n", read);
 }
 
@@ -241,7 +229,7 @@
 {
 	/*
 	 * If no sched_clock() function has been provided at that point,
-	 * make it the final one one.
+	 * make it the final one.
 	 */
 	if (cd.actual_read_sched_clock == jiffy_sched_clock_read)
 		sched_clock_register(jiffy_sched_clock_read, BITS_PER_LONG, HZ);
@@ -270,7 +258,7 @@
  */
 static u64 notrace suspended_sched_clock_read(void)
 {
-	unsigned int seq = raw_read_seqcount(&cd.seq);
+	unsigned int seq = raw_read_seqcount_latch(&cd.seq);
 
 	return cd.read_data[seq & 1].epoch_cyc;
 }
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index e51778c..36d7464 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -381,7 +381,7 @@
 	switch (mode) {
 	case TICK_BROADCAST_FORCE:
 		tick_broadcast_forced = 1;
-		/* fall through */
+		fallthrough;
 	case TICK_BROADCAST_ON:
 		cpumask_set_cpu(cpu, tick_broadcast_on);
 		if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_mask)) {
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 7e5d352..6c9c342 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -84,13 +84,15 @@
 static void tick_periodic(int cpu)
 {
 	if (tick_do_timer_cpu == cpu) {
-		write_seqlock(&jiffies_lock);
+		raw_spin_lock(&jiffies_lock);
+		write_seqcount_begin(&jiffies_seq);
 
 		/* Keep track of the next tick event */
 		tick_next_period = ktime_add(tick_next_period, tick_period);
 
 		do_timer(1);
-		write_sequnlock(&jiffies_lock);
+		write_seqcount_end(&jiffies_seq);
+		raw_spin_unlock(&jiffies_lock);
 		update_wall_time();
 	}
 
@@ -162,9 +164,9 @@
 		ktime_t next;
 
 		do {
-			seq = read_seqbegin(&jiffies_lock);
+			seq = read_seqcount_begin(&jiffies_seq);
 			next = tick_next_period;
-		} while (read_seqretry(&jiffies_lock, seq));
+		} while (read_seqcount_retry(&jiffies_seq, seq));
 
 		clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 4419486..e8d351b 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -65,7 +65,8 @@
 		return;
 
 	/* Reevaluate with jiffies_lock held */
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 
 	delta = ktime_sub(now, last_jiffies_update);
 	if (delta >= tick_period) {
@@ -91,10 +92,12 @@
 		/* Keep the tick_next_period variable up to date */
 		tick_next_period = ktime_add(last_jiffies_update, tick_period);
 	} else {
-		write_sequnlock(&jiffies_lock);
+		write_seqcount_end(&jiffies_seq);
+		raw_spin_unlock(&jiffies_lock);
 		return;
 	}
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	update_wall_time();
 }
 
@@ -105,12 +108,14 @@
 {
 	ktime_t period;
 
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 	/* Did we start the jiffies update yet ? */
 	if (last_jiffies_update == 0)
 		last_jiffies_update = tick_next_period;
 	period = last_jiffies_update;
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	return period;
 }
 
@@ -176,6 +181,7 @@
 #ifdef CONFIG_NO_HZ_FULL
 cpumask_var_t tick_nohz_full_mask;
 bool tick_nohz_full_running;
+EXPORT_SYMBOL_GPL(tick_nohz_full_running);
 static atomic_t tick_dep_mask;
 
 static bool check_tick_dependency(atomic_t *dep)
@@ -202,6 +208,11 @@
 		return true;
 	}
 
+	if (val & TICK_DEP_MASK_RCU) {
+		trace_tick_stop(0, TICK_DEP_MASK_RCU);
+		return true;
+	}
+
 	return false;
 }
 
@@ -234,6 +245,7 @@
 
 static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
 	.func = nohz_full_kick_func,
+	.flags = ATOMIC_INIT(IRQ_WORK_HARD_IRQ),
 };
 
 /*
@@ -328,6 +340,7 @@
 		preempt_enable();
 	}
 }
+EXPORT_SYMBOL_GPL(tick_nohz_dep_set_cpu);
 
 void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
 {
@@ -335,24 +348,35 @@
 
 	atomic_andnot(BIT(bit), &ts->tick_dep_mask);
 }
+EXPORT_SYMBOL_GPL(tick_nohz_dep_clear_cpu);
 
 /*
- * Set a per-task tick dependency. Posix CPU timers need this in order to elapse
- * per task timers.
+ * Set a per-task tick dependency. RCU need this. Also posix CPU timers
+ * in order to elapse per task timers.
  */
 void tick_nohz_dep_set_task(struct task_struct *tsk, enum tick_dep_bits bit)
 {
-	/*
-	 * We could optimize this with just kicking the target running the task
-	 * if that noise matters for nohz full users.
-	 */
-	tick_nohz_dep_set_all(&tsk->tick_dep_mask, bit);
+	if (!atomic_fetch_or(BIT(bit), &tsk->tick_dep_mask)) {
+		if (tsk == current) {
+			preempt_disable();
+			tick_nohz_full_kick();
+			preempt_enable();
+		} else {
+			/*
+			 * Some future tick_nohz_full_kick_task()
+			 * should optimize this.
+			 */
+			tick_nohz_full_kick_all();
+		}
+	}
 }
+EXPORT_SYMBOL_GPL(tick_nohz_dep_set_task);
 
 void tick_nohz_dep_clear_task(struct task_struct *tsk, enum tick_dep_bits bit)
 {
 	atomic_andnot(BIT(bit), &tsk->tick_dep_mask);
 }
+EXPORT_SYMBOL_GPL(tick_nohz_dep_clear_task);
 
 /*
  * Set a per-taskgroup tick dependency. Posix CPU timers need this in order to elapse
@@ -401,6 +425,7 @@
 	cpumask_copy(tick_nohz_full_mask, cpumask);
 	tick_nohz_full_running = true;
 }
+EXPORT_SYMBOL_GPL(tick_nohz_full_setup);
 
 static int tick_nohz_cpu_down(unsigned int cpu)
 {
@@ -665,10 +690,10 @@
 
 	/* Read jiffies and the time when jiffies were updated last */
 	do {
-		seq = read_seqbegin(&jiffies_lock);
+		seq = read_seqcount_begin(&jiffies_seq);
 		basemono = last_jiffies_update;
 		basejiff = jiffies;
-	} while (read_seqretry(&jiffies_lock, seq));
+	} while (read_seqcount_retry(&jiffies_seq, seq));
 	ts->last_jiffies = basejiff;
 	ts->timer_expires_base = basemono;
 
@@ -902,7 +927,7 @@
 
 		if (ratelimit < 10 &&
 		    (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
-			pr_warn("NOHZ: local_softirq_pending %02x\n",
+			pr_warn("NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #%02x!!!\n",
 				(unsigned int) local_softirq_pending());
 			ratelimit++;
 		}
@@ -1116,7 +1141,7 @@
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	unsigned long ticks;
 
-	if (vtime_accounting_cpu_enabled())
+	if (vtime_accounting_enabled_this_cpu())
 		return;
 	/*
 	 * We stopped the tick in idle. Update process times would miss the
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 83f403e..3985b2b 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -59,9 +59,9 @@
  * why not move it into the appropriate arch directory (for those
  * architectures that need it).
  */
-SYSCALL_DEFINE1(time, time_t __user *, tloc)
+SYSCALL_DEFINE1(time, __kernel_old_time_t __user *, tloc)
 {
-	time_t i = (time_t)ktime_get_real_seconds();
+	__kernel_old_time_t i = (__kernel_old_time_t)ktime_get_real_seconds();
 
 	if (tloc) {
 		if (put_user(i,tloc))
@@ -78,7 +78,7 @@
  * architectures that need it).
  */
 
-SYSCALL_DEFINE1(stime, time_t __user *, tptr)
+SYSCALL_DEFINE1(stime, __kernel_old_time_t __user *, tptr)
 {
 	struct timespec64 tv;
 	int err;
@@ -137,7 +137,7 @@
 #endif /* __ARCH_WANT_SYS_TIME32 */
 #endif
 
-SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
+SYSCALL_DEFINE2(gettimeofday, struct __kernel_old_timeval __user *, tv,
 		struct timezone __user *, tz)
 {
 	if (likely(tv != NULL)) {
@@ -179,7 +179,7 @@
 		return error;
 
 	if (tz) {
-		/* Verify we're witin the +-15 hrs range */
+		/* Verify we're within the +-15 hrs range */
 		if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60)
 			return -EINVAL;
 
@@ -196,22 +196,21 @@
 	return 0;
 }
 
-SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv,
+SYSCALL_DEFINE2(settimeofday, struct __kernel_old_timeval __user *, tv,
 		struct timezone __user *, tz)
 {
 	struct timespec64 new_ts;
-	struct timeval user_tv;
 	struct timezone new_tz;
 
 	if (tv) {
-		if (copy_from_user(&user_tv, tv, sizeof(*tv)))
+		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||
+		    get_user(new_ts.tv_nsec, &tv->tv_usec))
 			return -EFAULT;
 
-		if (!timeval_valid(&user_tv))
+		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)
 			return -EINVAL;
 
-		new_ts.tv_sec = user_tv.tv_sec;
-		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
+		new_ts.tv_nsec *= NSEC_PER_USEC;
 	}
 	if (tz) {
 		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
@@ -245,18 +244,17 @@
 		       struct timezone __user *, tz)
 {
 	struct timespec64 new_ts;
-	struct timeval user_tv;
 	struct timezone new_tz;
 
 	if (tv) {
-		if (compat_get_timeval(&user_tv, tv))
+		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||
+		    get_user(new_ts.tv_nsec, &tv->tv_usec))
 			return -EFAULT;
 
-		if (!timeval_valid(&user_tv))
+		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)
 			return -EINVAL;
 
-		new_ts.tv_sec = user_tv.tv_sec;
-		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
+		new_ts.tv_nsec *= NSEC_PER_USEC;
 	}
 	if (tz) {
 		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
@@ -267,7 +265,7 @@
 }
 #endif
 
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
 {
 	struct __kernel_timex txc;		/* Local copy of parameter */
@@ -451,49 +449,6 @@
 }
 EXPORT_SYMBOL(mktime64);
 
-/**
- * ns_to_timespec - Convert nanoseconds to timespec
- * @nsec:       the nanoseconds value to be converted
- *
- * Returns the timespec representation of the nsec parameter.
- */
-struct timespec ns_to_timespec(const s64 nsec)
-{
-	struct timespec ts;
-	s32 rem;
-
-	if (!nsec)
-		return (struct timespec) {0, 0};
-
-	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
-	if (unlikely(rem < 0)) {
-		ts.tv_sec--;
-		rem += NSEC_PER_SEC;
-	}
-	ts.tv_nsec = rem;
-
-	return ts;
-}
-EXPORT_SYMBOL(ns_to_timespec);
-
-/**
- * ns_to_timeval - Convert nanoseconds to timeval
- * @nsec:       the nanoseconds value to be converted
- *
- * Returns the timeval representation of the nsec parameter.
- */
-struct timeval ns_to_timeval(const s64 nsec)
-{
-	struct timespec ts = ns_to_timespec(nsec);
-	struct timeval tv;
-
-	tv.tv_sec = ts.tv_sec;
-	tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000;
-
-	return tv;
-}
-EXPORT_SYMBOL(ns_to_timeval);
-
 struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec)
 {
 	struct timespec64 ts = ns_to_timespec64(nsec);
@@ -550,18 +505,21 @@
  */
 struct timespec64 ns_to_timespec64(const s64 nsec)
 {
-	struct timespec64 ts;
+	struct timespec64 ts = { 0, 0 };
 	s32 rem;
 
-	if (!nsec)
-		return (struct timespec64) {0, 0};
-
-	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
-	if (unlikely(rem < 0)) {
-		ts.tv_sec--;
-		rem += NSEC_PER_SEC;
+	if (likely(nsec > 0)) {
+		ts.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
+		ts.tv_nsec = rem;
+	} else if (nsec < 0) {
+		/*
+		 * With negative times, tv_sec points to the earlier
+		 * second, and tv_nsec counts the nanoseconds since
+		 * then, so tv_nsec is always a positive number.
+		 */
+		ts.tv_sec = -div_u64_rem(-nsec - 1, NSEC_PER_SEC, &rem) - 1;
+		ts.tv_nsec = NSEC_PER_SEC - rem - 1;
 	}
-	ts.tv_nsec = rem;
 
 	return ts;
 }
@@ -625,10 +583,12 @@
  * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec
  * value to a scaled second value.
  */
-static unsigned long
-__timespec64_to_jiffies(u64 sec, long nsec)
+
+unsigned long
+timespec64_to_jiffies(const struct timespec64 *value)
 {
-	nsec = nsec + TICK_NSEC - 1;
+	u64 sec = value->tv_sec;
+	long nsec = value->tv_nsec + TICK_NSEC - 1;
 
 	if (sec >= MAX_SEC_IN_JIFFIES){
 		sec = MAX_SEC_IN_JIFFIES;
@@ -639,18 +599,6 @@
 		 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
 
 }
-
-static unsigned long
-__timespec_to_jiffies(unsigned long sec, long nsec)
-{
-	return __timespec64_to_jiffies((u64)sec, nsec);
-}
-
-unsigned long
-timespec64_to_jiffies(const struct timespec64 *value)
-{
-	return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec);
-}
 EXPORT_SYMBOL(timespec64_to_jiffies);
 
 void
@@ -668,44 +616,6 @@
 EXPORT_SYMBOL(jiffies_to_timespec64);
 
 /*
- * We could use a similar algorithm to timespec_to_jiffies (with a
- * different multiplier for usec instead of nsec). But this has a
- * problem with rounding: we can't exactly add TICK_NSEC - 1 to the
- * usec value, since it's not necessarily integral.
- *
- * We could instead round in the intermediate scaled representation
- * (i.e. in units of 1/2^(large scale) jiffies) but that's also
- * perilous: the scaling introduces a small positive error, which
- * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1
- * units to the intermediate before shifting) leads to accidental
- * overflow and overestimates.
- *
- * At the cost of one additional multiplication by a constant, just
- * use the timespec implementation.
- */
-unsigned long
-timeval_to_jiffies(const struct timeval *value)
-{
-	return __timespec_to_jiffies(value->tv_sec,
-				     value->tv_usec * NSEC_PER_USEC);
-}
-EXPORT_SYMBOL(timeval_to_jiffies);
-
-void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)
-{
-	/*
-	 * Convert jiffies to nanoseconds and separate with
-	 * one divide.
-	 */
-	u32 rem;
-
-	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
-				    NSEC_PER_SEC, &rem);
-	value->tv_usec = rem / NSEC_PER_USEC;
-}
-EXPORT_SYMBOL(jiffies_to_timeval);
-
-/*
  * Convert jiffies/jiffies_64 to clock_t and back.
  */
 clock_t jiffies_to_clock_t(unsigned long x)
@@ -880,11 +790,11 @@
 
 	ts->tv_sec = kts.tv_sec;
 
-	/* Zero out the padding for 32 bit systems or in compat mode */
-	if (IS_ENABLED(CONFIG_64BIT_TIME) && (!IS_ENABLED(CONFIG_64BIT) ||
-					      in_compat_syscall()))
+	/* Zero out the padding in compat mode */
+	if (in_compat_syscall())
 		kts.tv_nsec &= 0xFFFFFFFFUL;
 
+	/* In 32-bit mode, this drops the padding */
 	ts->tv_nsec = kts.tv_nsec;
 
 	return 0;
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 4fc2af4..cc4dc28 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -39,20 +39,24 @@
 	TK_ADV_FREQ
 };
 
+DEFINE_RAW_SPINLOCK(timekeeper_lock);
+
 /*
  * The most important data for readout fits into a single 64 byte
  * cache line.
  */
 static struct {
-	seqcount_t		seq;
+	seqcount_raw_spinlock_t	seq;
 	struct timekeeper	timekeeper;
 } tk_core ____cacheline_aligned = {
-	.seq = SEQCNT_ZERO(tk_core.seq),
+	.seq = SEQCNT_RAW_SPINLOCK_ZERO(tk_core.seq, &timekeeper_lock),
 };
 
-static DEFINE_RAW_SPINLOCK(timekeeper_lock);
 static struct timekeeper shadow_timekeeper;
 
+/* flag for if timekeeping is suspended */
+int __read_mostly timekeeping_suspended;
+
 /**
  * struct tk_fast - NMI safe timekeeper
  * @seq:	Sequence counter for protecting updates. The lowest bit
@@ -63,7 +67,7 @@
  * See @update_fast_timekeeper() below.
  */
 struct tk_fast {
-	seqcount_t		seq;
+	seqcount_latch_t	seq;
 	struct tk_read_base	base[2];
 };
 
@@ -72,26 +76,42 @@
 
 static u64 dummy_clock_read(struct clocksource *cs)
 {
-	return cycles_at_suspend;
+	if (timekeeping_suspended)
+		return cycles_at_suspend;
+	return local_clock();
 }
 
 static struct clocksource dummy_clock = {
 	.read = dummy_clock_read,
 };
 
+/*
+ * Boot time initialization which allows local_clock() to be utilized
+ * during early boot when clocksources are not available. local_clock()
+ * returns nanoseconds already so no conversion is required, hence mult=1
+ * and shift=0. When the first proper clocksource is installed then
+ * the fast time keepers are updated with the correct values.
+ */
+#define FAST_TK_INIT						\
+	{							\
+		.clock		= &dummy_clock,			\
+		.mask		= CLOCKSOURCE_MASK(64),		\
+		.mult		= 1,				\
+		.shift		= 0,				\
+	}
+
 static struct tk_fast tk_fast_mono ____cacheline_aligned = {
-	.base[0] = { .clock = &dummy_clock, },
-	.base[1] = { .clock = &dummy_clock, },
+	.seq     = SEQCNT_LATCH_ZERO(tk_fast_mono.seq),
+	.base[0] = FAST_TK_INIT,
+	.base[1] = FAST_TK_INIT,
 };
 
 static struct tk_fast tk_fast_raw  ____cacheline_aligned = {
-	.base[0] = { .clock = &dummy_clock, },
-	.base[1] = { .clock = &dummy_clock, },
+	.seq     = SEQCNT_LATCH_ZERO(tk_fast_raw.seq),
+	.base[0] = FAST_TK_INIT,
+	.base[1] = FAST_TK_INIT,
 };
 
-/* flag for if timekeeping is suspended */
-int __read_mostly timekeeping_suspended;
-
 static inline void tk_normalize_xtime(struct timekeeper *tk)
 {
 	while (tk->tkr_mono.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_mono.shift)) {
@@ -157,7 +177,7 @@
  * tk_clock_read - atomic clocksource read() helper
  *
  * This helper is necessary to use in the read paths because, while the
- * seqlock ensures we don't return a bad value while structures are updated,
+ * seqcount ensures we don't return a bad value while structures are updated,
  * it doesn't protect from potential crashes. There is the possibility that
  * the tkr's clocksource may change between the read reference, and the
  * clock reference passed to the read function.  This can cause crashes if
@@ -222,10 +242,10 @@
 	unsigned int seq;
 
 	/*
-	 * Since we're called holding a seqlock, the data may shift
+	 * Since we're called holding a seqcount, the data may shift
 	 * under us while we're doing the calculation. This can cause
 	 * false positives, since we'd note a problem but throw the
-	 * results away. So nest another seqlock here to atomically
+	 * results away. So nest another seqcount here to atomically
 	 * grab the points we are checking with.
 	 */
 	do {
@@ -464,7 +484,7 @@
 					tk_clock_read(tkr),
 					tkr->cycle_last,
 					tkr->mask));
-	} while (read_seqcount_retry(&tkf->seq, seq));
+	} while (read_seqcount_latch_retry(&tkf->seq, seq));
 
 	return now;
 }
@@ -486,7 +506,7 @@
  *
  * To keep it NMI safe since we're accessing from tracing, we're not using a
  * separate timekeeper with updates to monotonic clock and boot offset
- * protected with seqlocks. This has the following minor side effects:
+ * protected with seqcounts. This has the following minor side effects:
  *
  * (1) Its possible that a timestamp be taken after the boot offset is updated
  * but before the timekeeper is updated. If this happens, the new boot offset
@@ -510,29 +530,29 @@
 }
 EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);
 
-
 /*
  * See comment for __ktime_get_fast_ns() vs. timestamp ordering
  */
-static __always_inline u64 __ktime_get_real_fast_ns(struct tk_fast *tkf)
+static __always_inline u64 __ktime_get_real_fast(struct tk_fast *tkf, u64 *mono)
 {
 	struct tk_read_base *tkr;
+	u64 basem, baser, delta;
 	unsigned int seq;
-	u64 now;
 
 	do {
 		seq = raw_read_seqcount_latch(&tkf->seq);
 		tkr = tkf->base + (seq & 0x01);
-		now = ktime_to_ns(tkr->base_real);
+		basem = ktime_to_ns(tkr->base);
+		baser = ktime_to_ns(tkr->base_real);
 
-		now += timekeeping_delta_to_ns(tkr,
-				clocksource_delta(
-					tk_clock_read(tkr),
-					tkr->cycle_last,
-					tkr->mask));
-	} while (read_seqcount_retry(&tkf->seq, seq));
+		delta = timekeeping_delta_to_ns(tkr,
+				clocksource_delta(tk_clock_read(tkr),
+				tkr->cycle_last, tkr->mask));
+	} while (read_seqcount_latch_retry(&tkf->seq, seq));
 
-	return now;
+	if (mono)
+		*mono = basem + delta;
+	return baser + delta;
 }
 
 /**
@@ -540,11 +560,65 @@
  */
 u64 ktime_get_real_fast_ns(void)
 {
-	return __ktime_get_real_fast_ns(&tk_fast_mono);
+	return __ktime_get_real_fast(&tk_fast_mono, NULL);
 }
 EXPORT_SYMBOL_GPL(ktime_get_real_fast_ns);
 
 /**
+ * ktime_get_fast_timestamps: - NMI safe timestamps
+ * @snapshot:	Pointer to timestamp storage
+ *
+ * Stores clock monotonic, boottime and realtime timestamps.
+ *
+ * Boot time is a racy access on 32bit systems if the sleep time injection
+ * happens late during resume and not in timekeeping_resume(). That could
+ * be avoided by expanding struct tk_read_base with boot offset for 32bit
+ * and adding more overhead to the update. As this is a hard to observe
+ * once per resume event which can be filtered with reasonable effort using
+ * the accurate mono/real timestamps, it's probably not worth the trouble.
+ *
+ * Aside of that it might be possible on 32 and 64 bit to observe the
+ * following when the sleep time injection happens late:
+ *
+ * CPU 0				CPU 1
+ * timekeeping_resume()
+ * ktime_get_fast_timestamps()
+ *	mono, real = __ktime_get_real_fast()
+ *					inject_sleep_time()
+ *					   update boot offset
+ *	boot = mono + bootoffset;
+ *
+ * That means that boot time already has the sleep time adjustment, but
+ * real time does not. On the next readout both are in sync again.
+ *
+ * Preventing this for 64bit is not really feasible without destroying the
+ * careful cache layout of the timekeeper because the sequence count and
+ * struct tk_read_base would then need two cache lines instead of one.
+ *
+ * Access to the time keeper clock source is disabled accross the innermost
+ * steps of suspend/resume. The accessors still work, but the timestamps
+ * are frozen until time keeping is resumed which happens very early.
+ *
+ * For regular suspend/resume there is no observable difference vs. sched
+ * clock, but it might affect some of the nasty low level debug printks.
+ *
+ * OTOH, access to sched clock is not guaranteed accross suspend/resume on
+ * all systems either so it depends on the hardware in use.
+ *
+ * If that turns out to be a real problem then this could be mitigated by
+ * using sched clock in a similar way as during early boot. But it's not as
+ * trivial as on early boot because it needs some careful protection
+ * against the clock monotonic timestamp jumping backwards on resume.
+ */
+void ktime_get_fast_timestamps(struct ktime_timestamps *snapshot)
+{
+	struct timekeeper *tk = &tk_core.timekeeper;
+
+	snapshot->real = __ktime_get_real_fast(&tk_fast_mono, &snapshot->mono);
+	snapshot->boot = snapshot->mono + ktime_to_ns(data_race(tk->offs_boot));
+}
+
+/**
  * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource.
  * @tk: Timekeeper to snapshot.
  *
@@ -953,7 +1027,7 @@
  * but without the sequence counter protect. This internal function
  * is called just when timekeeping lock is already held.
  */
-time64_t __ktime_get_real_seconds(void)
+noinstr time64_t __ktime_get_real_seconds(void)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 
@@ -1236,8 +1310,7 @@
 	timekeeping_forward_now(tk);
 
 	xt = tk_xtime(tk);
-	ts_delta.tv_sec = ts->tv_sec - xt.tv_sec;
-	ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec;
+	ts_delta = timespec64_sub(*ts, xt);
 
 	if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) {
 		ret = -EINVAL;
@@ -2001,7 +2074,7 @@
  * logarithmic_accumulation - shifted accumulation of cycles
  *
  * This functions accumulates a shifted interval of cycles into
- * into a shifted interval nanoseconds. Allows for O(log) accumulation
+ * a shifted interval nanoseconds. Allows for O(log) accumulation
  * loop.
  *
  * Returns the unconsumed cycles.
@@ -2193,7 +2266,7 @@
 void do_timer(unsigned long ticks)
 {
 	jiffies_64 += ticks;
-	calc_global_load(ticks);
+	calc_global_load();
 }
 
 /**
@@ -2396,8 +2469,10 @@
  */
 void xtime_update(unsigned long ticks)
 {
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 	do_timer(ticks);
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	update_wall_time();
 }
diff --git a/kernel/time/timekeeping.h b/kernel/time/timekeeping.h
index 141ab3a..099737f 100644
--- a/kernel/time/timekeeping.h
+++ b/kernel/time/timekeeping.h
@@ -25,7 +25,8 @@
 extern void do_timer(unsigned long ticks);
 extern void update_wall_time(void);
 
-extern seqlock_t jiffies_lock;
+extern raw_spinlock_t jiffies_lock;
+extern seqcount_t jiffies_seq;
 
 #define CS_NAME_LEN	32
 
diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h
index bcbb52d..4ca2787 100644
--- a/kernel/time/timekeeping_internal.h
+++ b/kernel/time/timekeeping_internal.h
@@ -1,12 +1,14 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _TIMEKEEPING_INTERNAL_H
 #define _TIMEKEEPING_INTERNAL_H
+
+#include <linux/clocksource.h>
+#include <linux/spinlock.h>
+#include <linux/time.h>
+
 /*
  * timekeeping debug functions
  */
-#include <linux/clocksource.h>
-#include <linux/time.h>
-
 #ifdef CONFIG_DEBUG_FS
 extern void tk_debug_account_sleep_time(const struct timespec64 *t);
 #else
@@ -31,4 +33,7 @@
 }
 #endif
 
+/* Semi public for serialization of non timekeeper VDSO updates. */
+extern raw_spinlock_t timekeeper_lock;
+
 #endif /* _TIMEKEEPING_INTERNAL_H */
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 16a2b62..a3ec21b 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -157,7 +157,8 @@
 
 /*
  * The time start value for each level to select the bucket at enqueue
- * time.
+ * time. We start from the last possible delta of the previous level
+ * so that we can later add an extra LVL_GRAN(n) to n (see calc_index()).
  */
 #define LVL_START(n)	((LVL_SIZE - 1) << (((n) - 1) * LVL_CLK_SHIFT))
 
@@ -204,8 +205,9 @@
 	unsigned long		clk;
 	unsigned long		next_expiry;
 	unsigned int		cpu;
+	bool			next_expiry_recalc;
 	bool			is_idle;
-	bool			must_forward_clk;
+	bool			timers_pending;
 	DECLARE_BITMAP(pending_map, WHEEL_SIZE);
 	struct hlist_head	vectors[WHEEL_SIZE];
 } ____cacheline_aligned;
@@ -250,8 +252,7 @@
 }
 
 int timer_migration_handler(struct ctl_table *table, int write,
-			    void __user *buffer, size_t *lenp,
-			    loff_t *ppos)
+			    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -489,35 +490,48 @@
  * Helper function to calculate the array index for a given expiry
  * time.
  */
-static inline unsigned calc_index(unsigned expires, unsigned lvl)
+static inline unsigned calc_index(unsigned long expires, unsigned lvl,
+				  unsigned long *bucket_expiry)
 {
+
+	/*
+	 * The timer wheel has to guarantee that a timer does not fire
+	 * early. Early expiry can happen due to:
+	 * - Timer is armed at the edge of a tick
+	 * - Truncation of the expiry time in the outer wheel levels
+	 *
+	 * Round up with level granularity to prevent this.
+	 */
 	expires = (expires + LVL_GRAN(lvl)) >> LVL_SHIFT(lvl);
+	*bucket_expiry = expires << LVL_SHIFT(lvl);
 	return LVL_OFFS(lvl) + (expires & LVL_MASK);
 }
 
-static int calc_wheel_index(unsigned long expires, unsigned long clk)
+static int calc_wheel_index(unsigned long expires, unsigned long clk,
+			    unsigned long *bucket_expiry)
 {
 	unsigned long delta = expires - clk;
 	unsigned int idx;
 
 	if (delta < LVL_START(1)) {
-		idx = calc_index(expires, 0);
+		idx = calc_index(expires, 0, bucket_expiry);
 	} else if (delta < LVL_START(2)) {
-		idx = calc_index(expires, 1);
+		idx = calc_index(expires, 1, bucket_expiry);
 	} else if (delta < LVL_START(3)) {
-		idx = calc_index(expires, 2);
+		idx = calc_index(expires, 2, bucket_expiry);
 	} else if (delta < LVL_START(4)) {
-		idx = calc_index(expires, 3);
+		idx = calc_index(expires, 3, bucket_expiry);
 	} else if (delta < LVL_START(5)) {
-		idx = calc_index(expires, 4);
+		idx = calc_index(expires, 4, bucket_expiry);
 	} else if (delta < LVL_START(6)) {
-		idx = calc_index(expires, 5);
+		idx = calc_index(expires, 5, bucket_expiry);
 	} else if (delta < LVL_START(7)) {
-		idx = calc_index(expires, 6);
+		idx = calc_index(expires, 6, bucket_expiry);
 	} else if (LVL_DEPTH > 8 && delta < LVL_START(8)) {
-		idx = calc_index(expires, 7);
+		idx = calc_index(expires, 7, bucket_expiry);
 	} else if ((long) delta < 0) {
 		idx = clk & LVL_MASK;
+		*bucket_expiry = clk;
 	} else {
 		/*
 		 * Force expire obscene large timeouts to expire at the
@@ -526,34 +540,11 @@
 		if (delta >= WHEEL_TIMEOUT_CUTOFF)
 			expires = clk + WHEEL_TIMEOUT_MAX;
 
-		idx = calc_index(expires, LVL_DEPTH - 1);
+		idx = calc_index(expires, LVL_DEPTH - 1, bucket_expiry);
 	}
 	return idx;
 }
 
-/*
- * Enqueue the timer into the hash bucket, mark it pending in
- * the bitmap and store the index in the timer flags.
- */
-static void enqueue_timer(struct timer_base *base, struct timer_list *timer,
-			  unsigned int idx)
-{
-	hlist_add_head(&timer->entry, base->vectors + idx);
-	__set_bit(idx, base->pending_map);
-	timer_set_idx(timer, idx);
-
-	trace_timer_start(timer, timer->expires, timer->flags);
-}
-
-static void
-__internal_add_timer(struct timer_base *base, struct timer_list *timer)
-{
-	unsigned int idx;
-
-	idx = calc_wheel_index(timer->expires, base->clk);
-	enqueue_timer(base, timer, idx);
-}
-
 static void
 trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer)
 {
@@ -575,39 +566,54 @@
 	 * timer is not deferrable. If the other CPU is on the way to idle
 	 * then it can't set base->is_idle as we hold the base lock:
 	 */
-	if (!base->is_idle)
-		return;
-
-	/* Check whether this is the new first expiring timer: */
-	if (time_after_eq(timer->expires, base->next_expiry))
-		return;
-
-	/*
-	 * Set the next expiry time and kick the CPU so it can reevaluate the
-	 * wheel:
-	 */
-	if (time_before(timer->expires, base->clk)) {
-		/*
-		 * Prevent from forward_timer_base() moving the base->clk
-		 * backward
-		 */
-		base->next_expiry = base->clk;
-	} else {
-		base->next_expiry = timer->expires;
-	}
-	wake_up_nohz_cpu(base->cpu);
+	if (base->is_idle)
+		wake_up_nohz_cpu(base->cpu);
 }
 
-static void
-internal_add_timer(struct timer_base *base, struct timer_list *timer)
+/*
+ * Enqueue the timer into the hash bucket, mark it pending in
+ * the bitmap, store the index in the timer flags then wake up
+ * the target CPU if needed.
+ */
+static void enqueue_timer(struct timer_base *base, struct timer_list *timer,
+			  unsigned int idx, unsigned long bucket_expiry)
 {
-	__internal_add_timer(base, timer);
-	trigger_dyntick_cpu(base, timer);
+
+	hlist_add_head(&timer->entry, base->vectors + idx);
+	__set_bit(idx, base->pending_map);
+	timer_set_idx(timer, idx);
+
+	trace_timer_start(timer, timer->expires, timer->flags);
+
+	/*
+	 * Check whether this is the new first expiring timer. The
+	 * effective expiry time of the timer is required here
+	 * (bucket_expiry) instead of timer->expires.
+	 */
+	if (time_before(bucket_expiry, base->next_expiry)) {
+		/*
+		 * Set the next expiry time and kick the CPU so it
+		 * can reevaluate the wheel:
+		 */
+		base->next_expiry = bucket_expiry;
+		base->timers_pending = true;
+		base->next_expiry_recalc = false;
+		trigger_dyntick_cpu(base, timer);
+	}
+}
+
+static void internal_add_timer(struct timer_base *base, struct timer_list *timer)
+{
+	unsigned long bucket_expiry;
+	unsigned int idx;
+
+	idx = calc_wheel_index(timer->expires, base->clk, &bucket_expiry);
+	enqueue_timer(base, timer, idx, bucket_expiry);
 }
 
 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 
-static struct debug_obj_descr timer_debug_descr;
+static const struct debug_obj_descr timer_debug_descr;
 
 static void *timer_debug_hint(void *addr)
 {
@@ -662,7 +668,7 @@
 
 	case ODEBUG_STATE_ACTIVE:
 		WARN_ON(1);
-		/* fall through */
+		fallthrough;
 	default:
 		return false;
 	}
@@ -703,7 +709,7 @@
 	}
 }
 
-static struct debug_obj_descr timer_debug_descr = {
+static const struct debug_obj_descr timer_debug_descr = {
 	.name			= "timer_list",
 	.debug_hint		= timer_debug_hint,
 	.is_static_object	= timer_is_static_object,
@@ -728,11 +734,6 @@
 	debug_object_deactivate(timer, &timer_debug_descr);
 }
 
-static inline void debug_timer_free(struct timer_list *timer)
-{
-	debug_object_free(timer, &timer_debug_descr);
-}
-
 static inline void debug_timer_assert_init(struct timer_list *timer)
 {
 	debug_object_assert_init(timer, &timer_debug_descr);
@@ -790,6 +791,8 @@
 {
 	timer->entry.pprev = NULL;
 	timer->function = func;
+	if (WARN_ON_ONCE(flags & ~TIMER_INIT_FLAGS))
+		flags &= TIMER_INIT_FLAGS;
 	timer->flags = flags | raw_smp_processor_id();
 	lockdep_init_map(&timer->lockdep_map, name, key, 0);
 }
@@ -835,8 +838,10 @@
 	if (!timer_pending(timer))
 		return 0;
 
-	if (hlist_is_singular_node(&timer->entry, base->vectors + idx))
+	if (hlist_is_singular_node(&timer->entry, base->vectors + idx)) {
 		__clear_bit(idx, base->pending_map);
+		base->next_expiry_recalc = true;
+	}
 
 	detach_timer(timer, clear_pending);
 	return 1;
@@ -886,20 +891,14 @@
 
 static inline void forward_timer_base(struct timer_base *base)
 {
-#ifdef CONFIG_NO_HZ_COMMON
-	unsigned long jnow;
+	unsigned long jnow = READ_ONCE(jiffies);
 
 	/*
-	 * We only forward the base when we are idle or have just come out of
-	 * idle (must_forward_clk logic), and have a delta between base clock
-	 * and jiffies. In the common case, run_timers will take care of it.
+	 * No need to forward if we are close enough below jiffies.
+	 * Also while executing timers, base->clk is 1 offset ahead
+	 * of jiffies to avoid endless requeuing to current jffies.
 	 */
-	if (likely(!base->must_forward_clk))
-		return;
-
-	jnow = READ_ONCE(jiffies);
-	base->must_forward_clk = base->is_idle;
-	if ((long)(jnow - base->clk) < 2)
+	if ((long)(jnow - base->clk) < 1)
 		return;
 
 	/*
@@ -913,7 +912,6 @@
 			return;
 		base->clk = base->next_expiry;
 	}
-#endif
 }
 
 
@@ -956,13 +954,14 @@
 
 #define MOD_TIMER_PENDING_ONLY		0x01
 #define MOD_TIMER_REDUCE		0x02
+#define MOD_TIMER_NOTPENDING		0x04
 
 static inline int
 __mod_timer(struct timer_list *timer, unsigned long expires, unsigned int options)
 {
+	unsigned long clk = 0, flags, bucket_expiry;
 	struct timer_base *base, *new_base;
 	unsigned int idx = UINT_MAX;
-	unsigned long clk = 0, flags;
 	int ret = 0;
 
 	BUG_ON(!timer->function);
@@ -972,7 +971,7 @@
 	 * the timer is re-modified to have the same timeout or ends up in the
 	 * same array bucket then just return:
 	 */
-	if (timer_pending(timer)) {
+	if (!(options & MOD_TIMER_NOTPENDING) && timer_pending(timer)) {
 		/*
 		 * The downside of this optimization is that it can result in
 		 * larger granularity than you would get from adding a new
@@ -1001,7 +1000,7 @@
 		}
 
 		clk = base->clk;
-		idx = calc_wheel_index(expires, clk);
+		idx = calc_wheel_index(expires, clk, &bucket_expiry);
 
 		/*
 		 * Retrieve and compare the array index of the pending
@@ -1054,16 +1053,13 @@
 	/*
 	 * If 'idx' was calculated above and the base time did not advance
 	 * between calculating 'idx' and possibly switching the base, only
-	 * enqueue_timer() and trigger_dyntick_cpu() is required. Otherwise
-	 * we need to (re)calculate the wheel index via
-	 * internal_add_timer().
+	 * enqueue_timer() is required. Otherwise we need to (re)calculate
+	 * the wheel index via internal_add_timer().
 	 */
-	if (idx != UINT_MAX && clk == base->clk) {
-		enqueue_timer(base, timer, idx);
-		trigger_dyntick_cpu(base, timer);
-	} else {
+	if (idx != UINT_MAX && clk == base->clk)
+		enqueue_timer(base, timer, idx, bucket_expiry);
+	else
 		internal_add_timer(base, timer);
-	}
 
 out_unlock:
 	raw_spin_unlock_irqrestore(&base->lock, flags);
@@ -1145,7 +1141,7 @@
 void add_timer(struct timer_list *timer)
 {
 	BUG_ON(timer_pending(timer));
-	mod_timer(timer, timer->expires);
+	__mod_timer(timer, timer->expires, MOD_TIMER_NOTPENDING);
 }
 EXPORT_SYMBOL(add_timer);
 
@@ -1468,10 +1464,10 @@
 	}
 }
 
-static int __collect_expired_timers(struct timer_base *base,
-				    struct hlist_head *heads)
+static int collect_expired_timers(struct timer_base *base,
+				  struct hlist_head *heads)
 {
-	unsigned long clk = base->clk;
+	unsigned long clk = base->clk = base->next_expiry;
 	struct hlist_head *vec;
 	int i, levels = 0;
 	unsigned int idx;
@@ -1493,7 +1489,6 @@
 	return levels;
 }
 
-#ifdef CONFIG_NO_HZ_COMMON
 /*
  * Find the next pending bucket of a level. Search from level start (@offset)
  * + @clk upwards and if nothing there, search from start of the level
@@ -1526,6 +1521,7 @@
 	clk = base->clk;
 	for (lvl = 0; lvl < LVL_DEPTH; lvl++, offset += LVL_SIZE) {
 		int pos = next_pending_bucket(base, offset, clk & LVL_MASK);
+		unsigned long lvl_clk = clk & LVL_CLK_MASK;
 
 		if (pos >= 0) {
 			unsigned long tmp = clk + (unsigned long) pos;
@@ -1533,6 +1529,13 @@
 			tmp <<= LVL_SHIFT(lvl);
 			if (time_before(tmp, next))
 				next = tmp;
+
+			/*
+			 * If the next expiration happens before we reach
+			 * the next level, no need to check further.
+			 */
+			if (pos <= ((LVL_CLK_DIV - lvl_clk) & LVL_CLK_MASK))
+				break;
 		}
 		/*
 		 * Clock for the next level. If the current level clock lower
@@ -1570,13 +1573,18 @@
 		 * So the simple check whether the lower bits of the current
 		 * level are 0 or not is sufficient for all cases.
 		 */
-		adj = clk & LVL_CLK_MASK ? 1 : 0;
+		adj = lvl_clk ? 1 : 0;
 		clk >>= LVL_CLK_SHIFT;
 		clk += adj;
 	}
+
+	base->next_expiry_recalc = false;
+	base->timers_pending = !(next == base->clk + NEXT_TIMER_MAX_DELTA);
+
 	return next;
 }
 
+#ifdef CONFIG_NO_HZ_COMMON
 /*
  * Check, if the next hrtimer event is before the next timer wheel
  * event:
@@ -1623,7 +1631,6 @@
 	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
 	u64 expires = KTIME_MAX;
 	unsigned long nextevt;
-	bool is_max_delta;
 
 	/*
 	 * Pretend that there is no timer pending if the cpu is offline.
@@ -1633,9 +1640,10 @@
 		return expires;
 
 	raw_spin_lock(&base->lock);
-	nextevt = __next_timer_interrupt(base);
-	is_max_delta = (nextevt == base->clk + NEXT_TIMER_MAX_DELTA);
-	base->next_expiry = nextevt;
+	if (base->next_expiry_recalc)
+		base->next_expiry = __next_timer_interrupt(base);
+	nextevt = base->next_expiry;
+
 	/*
 	 * We have a fresh next event. Check whether we can forward the
 	 * base. We can only do that when @basej is past base->clk
@@ -1652,7 +1660,7 @@
 		expires = basem;
 		base->is_idle = false;
 	} else {
-		if (!is_max_delta)
+		if (base->timers_pending)
 			expires = basem + (u64)(nextevt - basej) * TICK_NSEC;
 		/*
 		 * If we expect to sleep more than a tick, mark the base idle.
@@ -1661,10 +1669,8 @@
 		 * logic is only maintained for the BASE_STD base, deferrable
 		 * timers may still see large granularity skew (by design).
 		 */
-		if ((expires - basem) > TICK_NSEC) {
-			base->must_forward_clk = true;
+		if ((expires - basem) > TICK_NSEC)
 			base->is_idle = true;
-		}
 	}
 	raw_spin_unlock(&base->lock);
 
@@ -1688,42 +1694,6 @@
 	 */
 	base->is_idle = false;
 }
-
-static int collect_expired_timers(struct timer_base *base,
-				  struct hlist_head *heads)
-{
-	unsigned long now = READ_ONCE(jiffies);
-
-	/*
-	 * NOHZ optimization. After a long idle sleep we need to forward the
-	 * base to current jiffies. Avoid a loop by searching the bitfield for
-	 * the next expiring timer.
-	 */
-	if ((long)(now - base->clk) > 2) {
-		unsigned long next = __next_timer_interrupt(base);
-
-		/*
-		 * If the next timer is ahead of time forward to current
-		 * jiffies, otherwise forward to the next expiry time:
-		 */
-		if (time_after(next, now)) {
-			/*
-			 * The call site will increment base->clk and then
-			 * terminate the expiry loop immediately.
-			 */
-			base->clk = now;
-			return 0;
-		}
-		base->clk = next;
-	}
-	return __collect_expired_timers(base, heads);
-}
-#else
-static inline int collect_expired_timers(struct timer_base *base,
-					 struct hlist_head *heads)
-{
-	return __collect_expired_timers(base, heads);
-}
 #endif
 
 /*
@@ -1734,6 +1704,8 @@
 {
 	struct task_struct *p = current;
 
+	PRANDOM_ADD_NOISE(jiffies, user_tick, p, 0);
+
 	/* Note: this timer irq context must be accounted for as well. */
 	account_process_tick(p, user_tick);
 	run_local_timers();
@@ -1756,32 +1728,23 @@
 	struct hlist_head heads[LVL_DEPTH];
 	int levels;
 
-	if (!time_after_eq(jiffies, base->clk))
+	if (time_before(jiffies, base->next_expiry))
 		return;
 
 	timer_base_lock_expiry(base);
 	raw_spin_lock_irq(&base->lock);
 
-	/*
-	 * timer_base::must_forward_clk must be cleared before running
-	 * timers so that any timer functions that call mod_timer() will
-	 * not try to forward the base. Idle tracking / clock forwarding
-	 * logic is only used with BASE_STD timers.
-	 *
-	 * The must_forward_clk flag is cleared unconditionally also for
-	 * the deferrable base. The deferrable base is not affected by idle
-	 * tracking and never forwarded, so clearing the flag is a NOOP.
-	 *
-	 * The fact that the deferrable base is never forwarded can cause
-	 * large variations in granularity for deferrable timers, but they
-	 * can be deferred for long periods due to idle anyway.
-	 */
-	base->must_forward_clk = false;
-
-	while (time_after_eq(jiffies, base->clk)) {
-
+	while (time_after_eq(jiffies, base->clk) &&
+	       time_after_eq(jiffies, base->next_expiry)) {
 		levels = collect_expired_timers(base, heads);
+		/*
+		 * The only possible reason for not finding any expired
+		 * timer at this clk is that all matching timers have been
+		 * dequeued.
+		 */
+		WARN_ON_ONCE(!levels && !base->next_expiry_recalc);
 		base->clk++;
+		base->next_expiry = __next_timer_interrupt(base);
 
 		while (levels--)
 			expire_timers(base, heads + levels);
@@ -1811,12 +1774,12 @@
 
 	hrtimer_run_queues();
 	/* Raise the softirq only if required. */
-	if (time_before(jiffies, base->clk)) {
+	if (time_before(jiffies, base->next_expiry)) {
 		if (!IS_ENABLED(CONFIG_NO_HZ_COMMON))
 			return;
 		/* CPU is awake, so check the deferrable base. */
 		base++;
-		if (time_before(jiffies, base->clk))
+		if (time_before(jiffies, base->next_expiry))
 			return;
 	}
 	raise_softirq(TIMER_SOFTIRQ);
@@ -1842,21 +1805,23 @@
  * schedule_timeout - sleep until timeout
  * @timeout: timeout value in jiffies
  *
- * Make the current task sleep until @timeout jiffies have
- * elapsed. The routine will return immediately unless
- * the current task state has been set (see set_current_state()).
+ * Make the current task sleep until @timeout jiffies have elapsed.
+ * The function behavior depends on the current task state
+ * (see also set_current_state() description):
  *
- * You can set the task state as follows -
+ * %TASK_RUNNING - the scheduler is called, but the task does not sleep
+ * at all. That happens because sched_submit_work() does nothing for
+ * tasks in %TASK_RUNNING state.
  *
  * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
  * pass before the routine returns unless the current task is explicitly
- * woken up, (e.g. by wake_up_process())".
+ * woken up, (e.g. by wake_up_process()).
  *
  * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
  * delivered to the current task or the current task is explicitly woken
  * up.
  *
- * The current task state is guaranteed to be TASK_RUNNING when this
+ * The current task state is guaranteed to be %TASK_RUNNING when this
  * routine returns.
  *
  * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
@@ -1864,7 +1829,7 @@
  * value will be %MAX_SCHEDULE_TIMEOUT.
  *
  * Returns 0 when the timer has expired otherwise the remaining time in
- * jiffies will be returned.  In all cases the return value is guaranteed
+ * jiffies will be returned. In all cases the return value is guaranteed
  * to be non-negative.
  */
 signed long __sched schedule_timeout(signed long timeout)
@@ -1905,7 +1870,7 @@
 
 	timer.task = current;
 	timer_setup_on_stack(&timer.timer, process_timeout, 0);
-	__mod_timer(&timer.timer, expire, 0);
+	__mod_timer(&timer.timer, expire, MOD_TIMER_NOTPENDING);
 	schedule();
 	del_singleshot_timer_sync(&timer.timer);
 
@@ -1978,8 +1943,8 @@
 		base = per_cpu_ptr(&timer_bases[b], cpu);
 		base->clk = jiffies;
 		base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA;
+		base->timers_pending = false;
 		base->is_idle = false;
-		base->must_forward_clk = true;
 	}
 	return 0;
 }
@@ -2032,6 +1997,7 @@
 		base->cpu = cpu;
 		raw_spin_lock_init(&base->lock);
 		base->clk = jiffies;
+		base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA;
 		timer_base_init_expiry_lock(base);
 	}
 }
@@ -2047,6 +2013,7 @@
 void __init init_timers(void)
 {
 	init_timer_cpus();
+	posix_cputimers_init_work();
 	open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
 }
 
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index 9577c89..88e6b8e 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -13,6 +13,8 @@
 #include <vdso/helpers.h>
 #include <vdso/vsyscall.h>
 
+#include "timekeeping_internal.h"
+
 static inline void update_vdso_data(struct vdso_data *vdata,
 				    struct timekeeper *tk)
 {
@@ -71,13 +73,15 @@
 {
 	struct vdso_data *vdata = __arch_get_k_vdso_data();
 	struct vdso_timestamp *vdso_ts;
+	s32 clock_mode;
 	u64 nsec;
 
 	/* copy vsyscall data */
 	vdso_write_begin(vdata);
 
-	vdata[CS_HRES_COARSE].clock_mode	= __arch_get_clock_mode(tk);
-	vdata[CS_RAW].clock_mode		= __arch_get_clock_mode(tk);
+	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
+	vdata[CS_HRES_COARSE].clock_mode	= clock_mode;
+	vdata[CS_RAW].clock_mode		= clock_mode;
 
 	/* CLOCK_REALTIME also required for time() */
 	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
@@ -103,10 +107,10 @@
 	WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
 
 	/*
-	 * Architectures can opt out of updating the high resolution part
-	 * of the VDSO.
+	 * If the current clocksource is not VDSO capable, then spare the
+	 * update of the high reolution parts.
 	 */
-	if (__arch_update_vdso_data())
+	if (clock_mode != VDSO_CLOCKMODE_NONE)
 		update_vdso_data(vdata, tk);
 
 	__arch_update_vsyscall(vdata, tk);
@@ -125,3 +129,42 @@
 
 	__arch_sync_vdso_data(vdata);
 }
+
+/**
+ * vdso_update_begin - Start of a VDSO update section
+ *
+ * Allows architecture code to safely update the architecture specific VDSO
+ * data. Disables interrupts, acquires timekeeper lock to serialize against
+ * concurrent updates from timekeeping and invalidates the VDSO data
+ * sequence counter to prevent concurrent readers from accessing
+ * inconsistent data.
+ *
+ * Returns: Saved interrupt flags which need to be handed in to
+ * vdso_update_end().
+ */
+unsigned long vdso_update_begin(void)
+{
+	struct vdso_data *vdata = __arch_get_k_vdso_data();
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	vdso_write_begin(vdata);
+	return flags;
+}
+
+/**
+ * vdso_update_end - End of a VDSO update section
+ * @flags:	Interrupt flags as returned from vdso_update_begin()
+ *
+ * Pairs with vdso_update_begin(). Marks vdso data consistent, invokes data
+ * synchronization if the architecture requires it, drops timekeeper lock
+ * and restores interrupt flags.
+ */
+void vdso_update_end(unsigned long flags)
+{
+	struct vdso_data *vdata = __arch_get_k_vdso_data();
+
+	vdso_write_end(vdata);
+	__arch_sync_vdso_data(vdata);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+}
diff --git a/kernel/torture.c b/kernel/torture.c
index 7c13f55..1061492 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -42,6 +42,12 @@
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
 
+static bool disable_onoff_at_boot;
+module_param(disable_onoff_at_boot, bool, 0444);
+
+static bool ftrace_dump_at_shutdown;
+module_param(ftrace_dump_at_shutdown, bool, 0444);
+
 static char *torture_type;
 static int verbose;
 
@@ -84,6 +90,7 @@
 {
 	unsigned long delta;
 	int ret;
+	char *s;
 	unsigned long starttime;
 
 	if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu))
@@ -97,12 +104,18 @@
 			 torture_type, cpu);
 	starttime = jiffies;
 	(*n_offl_attempts)++;
-	ret = cpu_down(cpu);
+	ret = remove_cpu(cpu);
 	if (ret) {
+		s = "";
+		if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) {
+			// PCI probe frequently disables hotplug during boot.
+			(*n_offl_attempts)--;
+			s = " (-EBUSY forgiven during boot)";
+		}
 		if (verbose)
 			pr_alert("%s" TORTURE_FLAG
-				 "torture_onoff task: offline %d failed: errno %d\n",
-				 torture_type, cpu, ret);
+				 "torture_onoff task: offline %d failed%s: errno %d\n",
+				 torture_type, cpu, s, ret);
 	} else {
 		if (verbose > 1)
 			pr_alert("%s" TORTURE_FLAG
@@ -137,6 +150,7 @@
 {
 	unsigned long delta;
 	int ret;
+	char *s;
 	unsigned long starttime;
 
 	if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu))
@@ -148,12 +162,18 @@
 			 torture_type, cpu);
 	starttime = jiffies;
 	(*n_onl_attempts)++;
-	ret = cpu_up(cpu);
+	ret = add_cpu(cpu);
 	if (ret) {
+		s = "";
+		if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) {
+			// PCI probe frequently disables hotplug during boot.
+			(*n_onl_attempts)--;
+			s = " (-EBUSY forgiven during boot)";
+		}
 		if (verbose)
 			pr_alert("%s" TORTURE_FLAG
-				 "torture_onoff task: online %d failed: errno %d\n",
-				 torture_type, cpu, ret);
+				 "torture_onoff task: online %d failed%s: errno %d\n",
+				 torture_type, cpu, s, ret);
 	} else {
 		if (verbose > 1)
 			pr_alert("%s" TORTURE_FLAG
@@ -192,17 +212,18 @@
 	for_each_online_cpu(cpu)
 		maxcpu = cpu;
 	WARN_ON(maxcpu < 0);
-	if (!IS_MODULE(CONFIG_TORTURE_TEST))
+	if (!IS_MODULE(CONFIG_TORTURE_TEST)) {
 		for_each_possible_cpu(cpu) {
 			if (cpu_online(cpu))
 				continue;
-			ret = cpu_up(cpu);
+			ret = add_cpu(cpu);
 			if (ret && verbose) {
 				pr_alert("%s" TORTURE_FLAG
 					 "%s: Initial online %d: errno %d\n",
 					 __func__, torture_type, cpu, ret);
 			}
 		}
+	}
 
 	if (maxcpu == 0) {
 		VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");
@@ -215,6 +236,10 @@
 		VERBOSE_TOROUT_STRING("torture_onoff end holdoff");
 	}
 	while (!torture_must_stop()) {
+		if (disable_onoff_at_boot && !rcu_inkernel_boot_has_ended()) {
+			schedule_timeout_interruptible(HZ / 10);
+			continue;
+		}
 		cpu = (torture_random(&rand) >> 4) % (maxcpu + 1);
 		if (!torture_offline(cpu,
 				     &n_offline_attempts, &n_offline_successes,
@@ -505,7 +530,8 @@
 		torture_shutdown_hook();
 	else
 		VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping.");
-	rcu_ftrace_dump(DUMP_ALL);
+	if (ftrace_dump_at_shutdown)
+		rcu_ftrace_dump(DUMP_ALL);
 	kernel_power_off();	/* Shut down the system. */
 	return 0;
 }
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 9fa01da..29db703 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -10,11 +10,6 @@
 config NOP_TRACER
 	bool
 
-config HAVE_FTRACE_NMI_ENTER
-	bool
-	help
-	  See Documentation/trace/ftrace-design.rst
-
 config HAVE_FUNCTION_TRACER
 	bool
 	help
@@ -33,6 +28,9 @@
 config HAVE_DYNAMIC_FTRACE_WITH_REGS
 	bool
 
+config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+	bool
+
 config HAVE_FTRACE_MCOUNT_RECORD
 	bool
 	help
@@ -69,14 +67,9 @@
 	select TRACE_CLOCK
 	select IRQ_WORK
 
-config FTRACE_NMI_ENTER
-       bool
-       depends on HAVE_FTRACE_NMI_ENTER
-       default y
-
 config EVENT_TRACING
 	select CONTEXT_SWITCH_TRACER
-        select GLOB
+	select GLOB
 	bool
 
 config CONTEXT_SWITCH_TRACER
@@ -106,7 +99,6 @@
 
 config TRACING
 	bool
-	select DEBUG_FS
 	select RING_BUFFER
 	select STACKTRACE if STACKTRACE_SUPPORT
 	select TRACEPOINTS
@@ -139,6 +131,15 @@
 
 if FTRACE
 
+config BOOTTIME_TRACING
+	bool "Boot-time Tracing support"
+	depends on TRACING
+	select BOOT_CONFIG
+	help
+	  Enable developer to setup ftrace subsystem via supplemental
+	  kernel cmdline at boot time for debugging (tracing) driver
+	  initialization and boot process.
+
 config FUNCTION_TRACER
 	bool "Kernel Function Tracer"
 	depends on HAVE_FUNCTION_TRACER
@@ -147,6 +148,7 @@
 	select CONTEXT_SWITCH_TRACER
 	select GLOB
 	select TASKS_RCU if PREEMPTION
+	select TASKS_RUDE_RCU
 	help
 	  Enable the kernel to trace every kernel function. This is done
 	  by using a compiler feature to insert a small, 5-byte No-Operation
@@ -170,21 +172,83 @@
 	  the return value. This is done by setting the current return
 	  address on the current task structure into a stack of calls.
 
+config DYNAMIC_FTRACE
+	bool "enable/disable function tracing dynamically"
+	depends on FUNCTION_TRACER
+	depends on HAVE_DYNAMIC_FTRACE
+	default y
+	help
+	  This option will modify all the calls to function tracing
+	  dynamically (will patch them out of the binary image and
+	  replace them with a No-Op instruction) on boot up. During
+	  compile time, a table is made of all the locations that ftrace
+	  can function trace, and this table is linked into the kernel
+	  image. When this is enabled, functions can be individually
+	  enabled, and the functions not enabled will not affect
+	  performance of the system.
+
+	  See the files in /sys/kernel/debug/tracing:
+	    available_filter_functions
+	    set_ftrace_filter
+	    set_ftrace_notrace
+
+	  This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
+	  otherwise has native performance as long as no tracing is active.
+
+config DYNAMIC_FTRACE_WITH_REGS
+	def_bool y
+	depends on DYNAMIC_FTRACE
+	depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
+
+config DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+	def_bool y
+	depends on DYNAMIC_FTRACE_WITH_REGS
+	depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+
+config FUNCTION_PROFILER
+	bool "Kernel function profiler"
+	depends on FUNCTION_TRACER
+	default n
+	help
+	  This option enables the kernel function profiler. A file is created
+	  in debugfs called function_profile_enabled which defaults to zero.
+	  When a 1 is echoed into this file profiling begins, and when a
+	  zero is entered, profiling stops. A "functions" file is created in
+	  the trace_stat directory; this file shows the list of functions that
+	  have been hit and their counters.
+
+	  If in doubt, say N.
+
+config STACK_TRACER
+	bool "Trace max stack"
+	depends on HAVE_FUNCTION_TRACER
+	select FUNCTION_TRACER
+	select STACKTRACE
+	select KALLSYMS
+	help
+	  This special tracer records the maximum stack footprint of the
+	  kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
+
+	  This tracer works by hooking into every function call that the
+	  kernel executes, and keeping a maximum stack depth value and
+	  stack-trace saved.  If this is configured with DYNAMIC_FTRACE
+	  then it will not have any overhead while the stack tracer
+	  is disabled.
+
+	  To enable the stack tracer on bootup, pass in 'stacktrace'
+	  on the kernel command line.
+
+	  The stack tracer can also be enabled or disabled via the
+	  sysctl kernel.stack_tracer_enabled
+
+	  Say N if unsure.
+
 config TRACE_PREEMPT_TOGGLE
 	bool
 	help
 	  Enables hooks which will be called when preemption is first disabled,
 	  and last enabled.
 
-config PREEMPTIRQ_EVENTS
-	bool "Enable trace events for preempt and irq disable/enable"
-	select TRACE_IRQFLAGS
-	select TRACE_PREEMPT_TOGGLE if PREEMPTION
-	select GENERIC_TRACER
-	default n
-	help
-	  Enable tracing of disable and enable events for preemption and irqs.
-
 config IRQSOFF_TRACER
 	bool "Interrupts-off Latency Tracer"
 	default n
@@ -280,6 +344,19 @@
 	 file. Every time a latency is greater than tracing_thresh, it will
 	 be recorded into the ring buffer.
 
+config MMIOTRACE
+	bool "Memory mapped IO tracing"
+	depends on HAVE_MMIOTRACE_SUPPORT && PCI
+	select GENERIC_TRACER
+	help
+	  Mmiotrace traces Memory Mapped I/O access and is meant for
+	  debugging and reverse engineering. It is called from the ioremap
+	  implementation and works via page faults. Tracing is disabled by
+	  default and can be enabled at run-time.
+
+	  See Documentation/trace/mmiotrace.rst.
+	  If you are not helping to develop drivers, say N.
+
 config ENABLE_DEFAULT_TRACERS
 	bool "Trace process context switches and events"
 	depends on !GENERIC_TRACER
@@ -308,7 +385,7 @@
 	      cat snapshot
 
 config TRACER_SNAPSHOT_PER_CPU_SWAP
-        bool "Allow snapshot to swap per CPU"
+	bool "Allow snapshot to swap per CPU"
 	depends on TRACER_SNAPSHOT
 	select RING_BUFFER_ALLOW_SWAP
 	help
@@ -407,30 +484,6 @@
 
 	  Say N if unsure.
 
-config STACK_TRACER
-	bool "Trace max stack"
-	depends on HAVE_FUNCTION_TRACER
-	select FUNCTION_TRACER
-	select STACKTRACE
-	select KALLSYMS
-	help
-	  This special tracer records the maximum stack footprint of the
-	  kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
-
-	  This tracer works by hooking into every function call that the
-	  kernel executes, and keeping a maximum stack depth value and
-	  stack-trace saved.  If this is configured with DYNAMIC_FTRACE
-	  then it will not have any overhead while the stack tracer
-	  is disabled.
-
-	  To enable the stack tracer on bootup, pass in 'stacktrace'
-	  on the kernel command line.
-
-	  The stack tracer can also be enabled or disabled via the
-	  sysctl kernel.stack_tracer_enabled
-
-	  Say N if unsure.
-
 config BLK_DEV_IO_TRACE
 	bool "Support for tracing block IO actions"
 	depends on SYSFS
@@ -528,48 +581,6 @@
 config PROBE_EVENTS
 	def_bool n
 
-config DYNAMIC_FTRACE
-	bool "enable/disable function tracing dynamically"
-	depends on FUNCTION_TRACER
-	depends on HAVE_DYNAMIC_FTRACE
-	default y
-	help
-	  This option will modify all the calls to function tracing
-	  dynamically (will patch them out of the binary image and
-	  replace them with a No-Op instruction) on boot up. During
-	  compile time, a table is made of all the locations that ftrace
-	  can function trace, and this table is linked into the kernel
-	  image. When this is enabled, functions can be individually
-	  enabled, and the functions not enabled will not affect
-	  performance of the system.
-
-	  See the files in /sys/kernel/debug/tracing:
-	    available_filter_functions
-	    set_ftrace_filter
-	    set_ftrace_notrace
-
-	  This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
-	  otherwise has native performance as long as no tracing is active.
-
-config DYNAMIC_FTRACE_WITH_REGS
-	def_bool y
-	depends on DYNAMIC_FTRACE
-	depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
-
-config FUNCTION_PROFILER
-	bool "Kernel function profiler"
-	depends on FUNCTION_TRACER
-	default n
-	help
-	  This option enables the kernel function profiler. A file is created
-	  in debugfs called function_profile_enabled which defaults to zero.
-	  When a 1 is echoed into this file profiling begins, and when a
-	  zero is entered, profiling stops. A "functions" file is created in
-	  the trace_stat directory; this file shows the list of functions that
-	  have been hit and their counters.
-
-	  If in doubt, say N.
-
 config BPF_KPROBE_OVERRIDE
 	bool "Enable BPF programs to override a kprobed function"
 	depends on BPF_EVENTS
@@ -584,54 +595,6 @@
 	depends on DYNAMIC_FTRACE
 	depends on HAVE_FTRACE_MCOUNT_RECORD
 
-config FTRACE_SELFTEST
-	bool
-
-config FTRACE_STARTUP_TEST
-	bool "Perform a startup test on ftrace"
-	depends on GENERIC_TRACER
-	select FTRACE_SELFTEST
-	help
-	  This option performs a series of startup tests on ftrace. On bootup
-	  a series of tests are made to verify that the tracer is
-	  functioning properly. It will do tests on all the configured
-	  tracers of ftrace.
-
-config EVENT_TRACE_STARTUP_TEST
-	bool "Run selftest on trace events"
-	depends on FTRACE_STARTUP_TEST
-	default y
-	help
-	  This option performs a test on all trace events in the system.
-	  It basically just enables each event and runs some code that
-	  will trigger events (not necessarily the event it enables)
-	  This may take some time run as there are a lot of events.
-
-config EVENT_TRACE_TEST_SYSCALLS
-	bool "Run selftest on syscall events"
-	depends on EVENT_TRACE_STARTUP_TEST
-	help
-	 This option will also enable testing every syscall event.
-	 It only enables the event and disables it and runs various loads
-	 with the event enabled. This adds a bit more time for kernel boot
-	 up since it runs this on every system call defined.
-
-	 TBD - enable a way to actually call the syscalls as we test their
-	       events
-
-config MMIOTRACE
-	bool "Memory mapped IO tracing"
-	depends on HAVE_MMIOTRACE_SUPPORT && PCI
-	select GENERIC_TRACER
-	help
-	  Mmiotrace traces Memory Mapped I/O access and is meant for
-	  debugging and reverse engineering. It is called from the ioremap
-	  implementation and works via page faults. Tracing is disabled by
-	  default and can be enabled at run-time.
-
-	  See Documentation/trace/mmiotrace.rst.
-	  If you are not helping to develop drivers, say N.
-
 config TRACING_MAP
 	bool
 	depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
@@ -642,12 +605,30 @@
 	  generally used outside of that context, and is normally
 	  selected by tracers that use it.
 
+config SYNTH_EVENTS
+	bool "Synthetic trace events"
+	select TRACING
+	select DYNAMIC_EVENTS
+	default n
+	help
+	  Synthetic events are user-defined trace events that can be
+	  used to combine data from other trace events or in fact any
+	  data source.  Synthetic events can be generated indirectly
+	  via the trace() action of histogram triggers or directly
+	  by way of an in-kernel API.
+
+	  See Documentation/trace/events.rst or
+	  Documentation/trace/histogram.rst for details and examples.
+
+	  If in doubt, say N.
+
 config HIST_TRIGGERS
 	bool "Histogram triggers"
 	depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select TRACING_MAP
 	select TRACING
 	select DYNAMIC_EVENTS
+	select SYNTH_EVENTS
 	default n
 	help
 	  Hist triggers allow one or more arbitrary trace event fields
@@ -663,18 +644,17 @@
 	  See Documentation/trace/histogram.rst.
 	  If in doubt, say N.
 
-config MMIOTRACE_TEST
-	tristate "Test module for mmiotrace"
-	depends on MMIOTRACE && m
+config TRACE_EVENT_INJECT
+	bool "Trace event injection"
+	depends on TRACING
 	help
-	  This is a dumb module for testing mmiotrace. It is very dangerous
-	  as it will write garbage to IO memory starting at a given address.
-	  However, it should be safe to use on e.g. unused portion of VRAM.
+	  Allow user-space to inject a specific trace event into the ring
+	  buffer. This is mainly used for testing purpose.
 
-	  Say N, unless you absolutely know what you are doing.
+	  If unsure, say N.
 
 config TRACEPOINT_BENCHMARK
-        bool "Add tracepoint that benchmarks tracepoints"
+	bool "Add tracepoint that benchmarks tracepoints"
 	help
 	 This option creates the tracepoint "benchmark:benchmark_event".
 	 When the tracepoint is enabled, it kicks off a kernel thread that
@@ -719,50 +699,12 @@
 
 	  If unsure, say N.
 
-config RING_BUFFER_STARTUP_TEST
-       bool "Ring buffer startup self test"
-       depends on RING_BUFFER
-       help
-         Run a simple self test on the ring buffer on boot up. Late in the
-	 kernel boot sequence, the test will start that kicks off
-	 a thread per cpu. Each thread will write various size events
-	 into the ring buffer. Another thread is created to send IPIs
-	 to each of the threads, where the IPI handler will also write
-	 to the ring buffer, to test/stress the nesting ability.
-	 If any anomalies are discovered, a warning will be displayed
-	 and all ring buffers will be disabled.
-
-	 The test runs for 10 seconds. This will slow your boot time
-	 by at least 10 more seconds.
-
-	 At the end of the test, statics and more checks are done.
-	 It will output the stats of each per cpu buffer. What
-	 was written, the sizes, what was read, what was lost, and
-	 other similar details.
-
-	 If unsure, say N
-
-config PREEMPTIRQ_DELAY_TEST
-	tristate "Preempt / IRQ disable delay thread to test latency tracers"
-	depends on m
-	help
-	  Select this option to build a test module that can help test latency
-	  tracers by executing a preempt or irq disable section with a user
-	  configurable delay. The module busy waits for the duration of the
-	  critical section.
-
-	  For example, the following invocation forces a one-time irq-disabled
-	  critical section for 500us:
-	  modprobe preemptirq_delay_test test_mode=irq delay=500000
-
-	  If unsure, say N
-
 config TRACE_EVAL_MAP_FILE
        bool "Show eval mappings for trace events"
        depends on TRACING
        help
 	The "print fmt" of the trace events will show the enum/sizeof names
-	instead	of their values. This can cause problems for user space tools
+	instead of their values. This can cause problems for user space tools
 	that use this string to parse the raw data as user space does not know
 	how to convert the string to its value.
 
@@ -783,7 +725,7 @@
 	they are needed for the "eval_map" file. Enabling this option will
 	increase the memory footprint of the running kernel.
 
-	If unsure, say N
+	If unsure, say N.
 
 config GCOV_PROFILE_FTRACE
 	bool "Enable GCOV profiling on ftrace subsystem"
@@ -797,6 +739,137 @@
 	  Note that on a kernel compiled with this config, ftrace will
 	  run significantly slower.
 
+config FTRACE_SELFTEST
+	bool
+
+config FTRACE_STARTUP_TEST
+	bool "Perform a startup test on ftrace"
+	depends on GENERIC_TRACER
+	select FTRACE_SELFTEST
+	help
+	  This option performs a series of startup tests on ftrace. On bootup
+	  a series of tests are made to verify that the tracer is
+	  functioning properly. It will do tests on all the configured
+	  tracers of ftrace.
+
+config EVENT_TRACE_STARTUP_TEST
+	bool "Run selftest on trace events"
+	depends on FTRACE_STARTUP_TEST
+	default y
+	help
+	  This option performs a test on all trace events in the system.
+	  It basically just enables each event and runs some code that
+	  will trigger events (not necessarily the event it enables)
+	  This may take some time run as there are a lot of events.
+
+config EVENT_TRACE_TEST_SYSCALLS
+	bool "Run selftest on syscall events"
+	depends on EVENT_TRACE_STARTUP_TEST
+	help
+	 This option will also enable testing every syscall event.
+	 It only enables the event and disables it and runs various loads
+	 with the event enabled. This adds a bit more time for kernel boot
+	 up since it runs this on every system call defined.
+
+	 TBD - enable a way to actually call the syscalls as we test their
+	       events
+
+config RING_BUFFER_STARTUP_TEST
+       bool "Ring buffer startup self test"
+       depends on RING_BUFFER
+       help
+	 Run a simple self test on the ring buffer on boot up. Late in the
+	 kernel boot sequence, the test will start that kicks off
+	 a thread per cpu. Each thread will write various size events
+	 into the ring buffer. Another thread is created to send IPIs
+	 to each of the threads, where the IPI handler will also write
+	 to the ring buffer, to test/stress the nesting ability.
+	 If any anomalies are discovered, a warning will be displayed
+	 and all ring buffers will be disabled.
+
+	 The test runs for 10 seconds. This will slow your boot time
+	 by at least 10 more seconds.
+
+	 At the end of the test, statics and more checks are done.
+	 It will output the stats of each per cpu buffer. What
+	 was written, the sizes, what was read, what was lost, and
+	 other similar details.
+
+	 If unsure, say N
+
+config MMIOTRACE_TEST
+	tristate "Test module for mmiotrace"
+	depends on MMIOTRACE && m
+	help
+	  This is a dumb module for testing mmiotrace. It is very dangerous
+	  as it will write garbage to IO memory starting at a given address.
+	  However, it should be safe to use on e.g. unused portion of VRAM.
+
+	  Say N, unless you absolutely know what you are doing.
+
+config PREEMPTIRQ_DELAY_TEST
+	tristate "Test module to create a preempt / IRQ disable delay thread to test latency tracers"
+	depends on m
+	help
+	  Select this option to build a test module that can help test latency
+	  tracers by executing a preempt or irq disable section with a user
+	  configurable delay. The module busy waits for the duration of the
+	  critical section.
+
+	  For example, the following invocation generates a burst of three
+	  irq-disabled critical sections for 500us:
+	  modprobe preemptirq_delay_test test_mode=irq delay=500 burst_size=3
+
+	  If unsure, say N
+
+config SYNTH_EVENT_GEN_TEST
+	tristate "Test module for in-kernel synthetic event generation"
+	depends on SYNTH_EVENTS
+	help
+          This option creates a test module to check the base
+          functionality of in-kernel synthetic event definition and
+          generation.
+
+          To test, insert the module, and then check the trace buffer
+	  for the generated sample events.
+
+	  If unsure, say N.
+
+config KPROBE_EVENT_GEN_TEST
+	tristate "Test module for in-kernel kprobe event generation"
+	depends on KPROBE_EVENTS
+	help
+          This option creates a test module to check the base
+          functionality of in-kernel kprobe event definition.
+
+          To test, insert the module, and then check the trace buffer
+	  for the generated kprobe events.
+
+	  If unsure, say N.
+
+config HIST_TRIGGERS_DEBUG
+	bool "Hist trigger debug support"
+	depends on HIST_TRIGGERS
+	help
+          Add "hist_debug" file for each event, which when read will
+          dump out a bunch of internal details about the hist triggers
+          defined on that event.
+
+          The hist_debug file serves a couple of purposes:
+
+            - Helps developers verify that nothing is broken.
+
+            - Provides educational information to support the details
+              of the hist trigger internals as described by
+              Documentation/trace/histogram-design.rst.
+
+          The hist_debug output only covers the data structures
+          related to the histogram definitions themselves and doesn't
+          display the internals of map buckets or variable values of
+          running histograms.
+
+          If unsure, say N.
+
 endif # FTRACE
 
 endif # TRACING_SUPPORT
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index c2b2148..e153be3 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -2,9 +2,12 @@
 
 # Do not instrument the tracer itself:
 
+ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE)
+
 ifdef CONFIG_FUNCTION_TRACER
-ORIG_CFLAGS := $(KBUILD_CFLAGS)
-KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS))
+
+# Avoid recursion due to instrumentation.
+KCSAN_SANITIZE := n
 
 ifdef CONFIG_FTRACE_SELFTEST
 # selftest needs instrumentation
@@ -28,6 +31,8 @@
 GCOV_PROFILE := y
 endif
 
+CFLAGS_bpf_trace.o := -I$(src)
+
 CFLAGS_trace_benchmark.o := -I$(src)
 CFLAGS_trace_events_filter.o := -I$(src)
 
@@ -44,6 +49,8 @@
 obj-$(CONFIG_TRACING) += trace_printk.o
 obj-$(CONFIG_TRACING_MAP) += tracing_map.o
 obj-$(CONFIG_PREEMPTIRQ_DELAY_TEST) += preemptirq_delay_test.o
+obj-$(CONFIG_SYNTH_EVENT_GEN_TEST) += synth_event_gen_test.o
+obj-$(CONFIG_KPROBE_EVENT_GEN_TEST) += kprobe_event_gen_test.o
 obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
 obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
 obj-$(CONFIG_PREEMPTIRQ_TRACEPOINTS) += trace_preemptirq.o
@@ -69,6 +76,8 @@
 endif
 obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
 obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o
+obj-$(CONFIG_TRACE_EVENT_INJECT) += trace_events_inject.o
+obj-$(CONFIG_SYNTH_EVENTS) += trace_events_synth.o
 obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o
 obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o
 obj-$(CONFIG_KPROBE_EVENTS) += trace_kprobe.o
@@ -82,6 +91,7 @@
 obj-$(CONFIG_DYNAMIC_EVENTS) += trace_dynevent.o
 obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o
 obj-$(CONFIG_UPROBE_EVENTS) += trace_uprobe.o
+obj-$(CONFIG_BOOTTIME_TRACING) += trace_boot.o
 
 obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o
 
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 884333b..b89ff18 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -67,19 +67,18 @@
  * Send out a notify message.
  */
 static void trace_note(struct blk_trace *bt, pid_t pid, int action,
-		       const void *data, size_t len,
-		       union kernfs_node_id *cgid)
+		       const void *data, size_t len, u64 cgid)
 {
 	struct blk_io_trace *t;
 	struct ring_buffer_event *event = NULL;
-	struct ring_buffer *buffer = NULL;
+	struct trace_buffer *buffer = NULL;
 	int pc = 0;
 	int cpu = smp_processor_id();
 	bool blk_tracer = blk_tracer_enabled;
-	ssize_t cgid_len = cgid ? sizeof(*cgid) : 0;
+	ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
 
 	if (blk_tracer) {
-		buffer = blk_tr->trace_buffer.buffer;
+		buffer = blk_tr->array_buffer.buffer;
 		pc = preempt_count();
 		event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
 						  sizeof(*t) + len + cgid_len,
@@ -103,8 +102,8 @@
 		t->pid = pid;
 		t->cpu = cpu;
 		t->pdu_len = len + cgid_len;
-		if (cgid)
-			memcpy((void *)t + sizeof(*t), cgid, cgid_len);
+		if (cgid_len)
+			memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
 		memcpy((void *) t + sizeof(*t) + cgid_len, data, len);
 
 		if (blk_tracer)
@@ -125,7 +124,7 @@
 	spin_lock_irqsave(&running_trace_lock, flags);
 	list_for_each_entry(bt, &running_trace_list, running_list) {
 		trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm,
-			   sizeof(tsk->comm), NULL);
+			   sizeof(tsk->comm), 0);
 	}
 	spin_unlock_irqrestore(&running_trace_lock, flags);
 }
@@ -142,7 +141,7 @@
 	words[1] = now.tv_nsec;
 
 	local_irq_save(flags);
-	trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), NULL);
+	trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0);
 	local_irq_restore(flags);
 }
 
@@ -174,10 +173,10 @@
 	if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
 		blkcg = NULL;
 #ifdef CONFIG_BLK_CGROUP
-	trace_note(bt, 0, BLK_TN_MESSAGE, buf, n,
-		blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : NULL);
+	trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n,
+		   blkcg ? cgroup_id(blkcg->css.cgroup) : 1);
 #else
-	trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, NULL);
+	trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, 0);
 #endif
 	local_irq_restore(flags);
 }
@@ -215,18 +214,18 @@
  */
 static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 		     int op, int op_flags, u32 what, int error, int pdu_len,
-		     void *pdu_data, union kernfs_node_id *cgid)
+		     void *pdu_data, u64 cgid)
 {
 	struct task_struct *tsk = current;
 	struct ring_buffer_event *event = NULL;
-	struct ring_buffer *buffer = NULL;
+	struct trace_buffer *buffer = NULL;
 	struct blk_io_trace *t;
 	unsigned long flags = 0;
 	unsigned long *sequence;
 	pid_t pid;
 	int cpu, pc = 0;
 	bool blk_tracer = blk_tracer_enabled;
-	ssize_t cgid_len = cgid ? sizeof(*cgid) : 0;
+	ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
 
 	if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
 		return;
@@ -252,7 +251,7 @@
 	if (blk_tracer) {
 		tracing_record_cmdline(current);
 
-		buffer = blk_tr->trace_buffer.buffer;
+		buffer = blk_tr->array_buffer.buffer;
 		pc = preempt_count();
 		event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
 						  sizeof(*t) + pdu_len + cgid_len,
@@ -297,7 +296,7 @@
 		t->pdu_len = pdu_len + cgid_len;
 
 		if (cgid_len)
-			memcpy((void *)t + sizeof(*t), cgid, cgid_len);
+			memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
 		if (pdu_len)
 			memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
 
@@ -348,7 +347,8 @@
 {
 	struct blk_trace *bt;
 
-	bt = xchg(&q->blk_trace, NULL);
+	bt = rcu_replace_pointer(q->blk_trace, NULL,
+				 lockdep_is_held(&q->debugfs_mutex));
 	if (!bt)
 		return -EINVAL;
 
@@ -362,9 +362,9 @@
 {
 	int ret;
 
-	mutex_lock(&q->blk_trace_mutex);
+	mutex_lock(&q->debugfs_mutex);
 	ret = __blk_trace_remove(q);
-	mutex_unlock(&q->blk_trace_mutex);
+	mutex_unlock(&q->debugfs_mutex);
 
 	return ret;
 }
@@ -483,12 +483,11 @@
 	struct dentry *dir = NULL;
 	int ret;
 
+	lockdep_assert_held(&q->debugfs_mutex);
+
 	if (!buts->buf_size || !buts->buf_nr)
 		return -EINVAL;
 
-	if (!blk_debugfs_root)
-		return -ENOENT;
-
 	strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
 	buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
 
@@ -502,7 +501,8 @@
 	 * bdev can be NULL, as with scsi-generic, this is a helpful as
 	 * we can be.
 	 */
-	if (q->blk_trace) {
+	if (rcu_dereference_protected(q->blk_trace,
+				      lockdep_is_held(&q->debugfs_mutex))) {
 		pr_warn("Concurrent blktraces are not allowed on %s\n",
 			buts->name);
 		return -EBUSY;
@@ -521,18 +521,15 @@
 	if (!bt->msg_data)
 		goto err;
 
-#ifdef CONFIG_BLK_DEBUG_FS
 	/*
-	 * When tracing whole make_request drivers (multiqueue) block devices,
-	 * reuse the existing debugfs directory created by the block layer on
-	 * init. For request-based block devices, all partitions block devices,
+	 * When tracing the whole disk reuse the existing debugfs directory
+	 * created by the block layer on init. For partitions block devices,
 	 * and scsi-generic block devices we create a temporary new debugfs
 	 * directory that will be removed once the trace ends.
 	 */
-	if (queue_is_mq(q) && bdev && bdev == bdev->bd_contains)
+	if (bdev && !bdev_is_partition(bdev))
 		dir = q->debugfs_dir;
 	else
-#endif
 		bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
 
 	/*
@@ -577,10 +574,7 @@
 	bt->pid = buts->pid;
 	bt->trace_state = Blktrace_setup;
 
-	ret = -EBUSY;
-	if (cmpxchg(&q->blk_trace, NULL, bt))
-		goto err;
-
+	rcu_assign_pointer(q->blk_trace, bt);
 	get_probe_ref();
 
 	ret = 0;
@@ -617,9 +611,9 @@
 {
 	int ret;
 
-	mutex_lock(&q->blk_trace_mutex);
+	mutex_lock(&q->debugfs_mutex);
 	ret = __blk_trace_setup(q, name, dev, bdev, arg);
-	mutex_unlock(&q->blk_trace_mutex);
+	mutex_unlock(&q->debugfs_mutex);
 
 	return ret;
 }
@@ -665,7 +659,7 @@
 	struct blk_trace *bt;
 
 	bt = rcu_dereference_protected(q->blk_trace,
-				       lockdep_is_held(&q->blk_trace_mutex));
+				       lockdep_is_held(&q->debugfs_mutex));
 	if (bt == NULL)
 		return -EINVAL;
 
@@ -705,9 +699,9 @@
 {
 	int ret;
 
-	mutex_lock(&q->blk_trace_mutex);
+	mutex_lock(&q->debugfs_mutex);
 	ret = __blk_trace_startstop(q, start);
-	mutex_unlock(&q->blk_trace_mutex);
+	mutex_unlock(&q->debugfs_mutex);
 
 	return ret;
 }
@@ -736,7 +730,7 @@
 	if (!q)
 		return -ENXIO;
 
-	mutex_lock(&q->blk_trace_mutex);
+	mutex_lock(&q->debugfs_mutex);
 
 	switch (cmd) {
 	case BLKTRACESETUP:
@@ -751,7 +745,7 @@
 #endif
 	case BLKTRACESTART:
 		start = 1;
-		/* fall through */
+		fallthrough;
 	case BLKTRACESTOP:
 		ret = __blk_trace_startstop(q, start);
 		break;
@@ -763,7 +757,7 @@
 		break;
 	}
 
-	mutex_unlock(&q->blk_trace_mutex);
+	mutex_unlock(&q->debugfs_mutex);
 	return ret;
 }
 
@@ -774,44 +768,42 @@
  **/
 void blk_trace_shutdown(struct request_queue *q)
 {
-	mutex_lock(&q->blk_trace_mutex);
+	mutex_lock(&q->debugfs_mutex);
 	if (rcu_dereference_protected(q->blk_trace,
-				      lockdep_is_held(&q->blk_trace_mutex))) {
+				      lockdep_is_held(&q->debugfs_mutex))) {
 		__blk_trace_startstop(q, 0);
 		__blk_trace_remove(q);
 	}
 
-	mutex_unlock(&q->blk_trace_mutex);
+	mutex_unlock(&q->debugfs_mutex);
 }
 
 #ifdef CONFIG_BLK_CGROUP
-static union kernfs_node_id *
-blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
+static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
 {
 	struct blk_trace *bt;
 
 	/* We don't use the 'bt' value here except as an optimization... */
 	bt = rcu_dereference_protected(q->blk_trace, 1);
 	if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
-		return NULL;
+		return 0;
 
 	if (!bio->bi_blkg)
-		return NULL;
-	return cgroup_get_kernfs_id(bio_blkcg(bio)->css.cgroup);
+		return 0;
+	return cgroup_id(bio_blkcg(bio)->css.cgroup);
 }
 #else
-static union kernfs_node_id *
-blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
+static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
 {
-	return NULL;
+	return 0;
 }
 #endif
 
-static union kernfs_node_id *
+static u64
 blk_trace_request_get_cgid(struct request_queue *q, struct request *rq)
 {
 	if (!rq->bio)
-		return NULL;
+		return 0;
 	/* Use the first bio */
 	return blk_trace_bio_get_cgid(q, rq->bio);
 }
@@ -833,8 +825,7 @@
  *
  **/
 static void blk_add_trace_rq(struct request *rq, int error,
-			     unsigned int nr_bytes, u32 what,
-			     union kernfs_node_id *cgid)
+			     unsigned int nr_bytes, u32 what, u64 cgid)
 {
 	struct blk_trace *bt;
 
@@ -869,6 +860,13 @@
 			 blk_trace_request_get_cgid(q, rq));
 }
 
+static void blk_add_trace_rq_merge(void *ignore,
+				   struct request_queue *q, struct request *rq)
+{
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE,
+			 blk_trace_request_get_cgid(q, rq));
+}
+
 static void blk_add_trace_rq_requeue(void *ignore,
 				     struct request_queue *q,
 				     struct request *rq)
@@ -920,10 +918,10 @@
 }
 
 static void blk_add_trace_bio_complete(void *ignore,
-				       struct request_queue *q, struct bio *bio,
-				       int error)
+				       struct request_queue *q, struct bio *bio)
 {
-	blk_add_trace_bio(q, bio, BLK_TA_COMPLETE, error);
+	blk_add_trace_bio(q, bio, BLK_TA_COMPLETE,
+			  blk_status_to_errno(bio->bi_status));
 }
 
 static void blk_add_trace_bio_backmerge(void *ignore,
@@ -961,7 +959,7 @@
 		bt = rcu_dereference(q->blk_trace);
 		if (bt)
 			__blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0,
-					NULL, NULL);
+					NULL, 0);
 		rcu_read_unlock();
 	}
 }
@@ -980,7 +978,7 @@
 		bt = rcu_dereference(q->blk_trace);
 		if (bt)
 			__blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_SLEEPRQ,
-					0, 0, NULL, NULL);
+					0, 0, NULL, 0);
 		rcu_read_unlock();
 	}
 }
@@ -992,7 +990,7 @@
 	rcu_read_lock();
 	bt = rcu_dereference(q->blk_trace);
 	if (bt)
-		__blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, NULL);
+		__blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, 0);
 	rcu_read_unlock();
 }
 
@@ -1012,7 +1010,7 @@
 		else
 			what = BLK_TA_UNPLUG_TIMER;
 
-		__blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, NULL);
+		__blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, 0);
 	}
 	rcu_read_unlock();
 }
@@ -1153,6 +1151,8 @@
 	WARN_ON(ret);
 	ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
 	WARN_ON(ret);
+	ret = register_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
+	WARN_ON(ret);
 	ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
 	WARN_ON(ret);
 	ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
@@ -1199,6 +1199,7 @@
 	unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
 	unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
 	unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
+	unregister_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
 	unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
 	unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
 
@@ -1251,19 +1252,17 @@
 
 static inline const void *pdu_start(const struct trace_entry *ent, bool has_cg)
 {
-	return (void *)(te_blk_io_trace(ent) + 1) +
-		(has_cg ? sizeof(union kernfs_node_id) : 0);
+	return (void *)(te_blk_io_trace(ent) + 1) + (has_cg ? sizeof(u64) : 0);
 }
 
-static inline const void *cgid_start(const struct trace_entry *ent)
+static inline u64 t_cgid(const struct trace_entry *ent)
 {
-	return (void *)(te_blk_io_trace(ent) + 1);
+	return *(u64 *)(te_blk_io_trace(ent) + 1);
 }
 
 static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg)
 {
-	return te_blk_io_trace(ent)->pdu_len -
-			(has_cg ? sizeof(union kernfs_node_id) : 0);
+	return te_blk_io_trace(ent)->pdu_len - (has_cg ? sizeof(u64) : 0);
 }
 
 static inline u32 t_action(const struct trace_entry *ent)
@@ -1325,7 +1324,7 @@
 
 	fill_rwbs(rwbs, t);
 	if (has_cg) {
-		const union kernfs_node_id *id = cgid_start(iter->ent);
+		u64 id = t_cgid(iter->ent);
 
 		if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) {
 			char blkcg_name_buf[NAME_MAX + 1] = "<...>";
@@ -1335,11 +1334,25 @@
 			trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ",
 				 MAJOR(t->device), MINOR(t->device),
 				 blkcg_name_buf, act, rwbs);
-		} else
+		} else {
+			/*
+			 * The cgid portion used to be "INO,GEN".  Userland
+			 * builds a FILEID_INO32_GEN fid out of them and
+			 * opens the cgroup using open_by_handle_at(2).
+			 * While 32bit ino setups are still the same, 64bit
+			 * ones now use the 64bit ino as the whole ID and
+			 * no longer use generation.
+			 *
+			 * Regarldess of the content, always output
+			 * "LOW32,HIGH32" so that FILEID_INO32_GEN fid can
+			 * be mapped back to @id on both 64 and 32bit ino
+			 * setups.  See __kernfs_fh_to_dentry().
+			 */
 			trace_seq_printf(&iter->seq,
-				 "%3d,%-3d %x,%-x %2s %3s ",
+				 "%3d,%-3d %llx,%-llx %2s %3s ",
 				 MAJOR(t->device), MINOR(t->device),
-				 id->ino, id->generation, act, rwbs);
+				 id & U32_MAX, id >> 32, act, rwbs);
+		}
 	} else
 		trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
 				 MAJOR(t->device), MINOR(t->device), act, rwbs);
@@ -1652,10 +1665,19 @@
 {
 	struct blk_trace *bt;
 
-	bt = xchg(&q->blk_trace, NULL);
+	bt = rcu_replace_pointer(q->blk_trace, NULL,
+				 lockdep_is_held(&q->debugfs_mutex));
 	if (bt == NULL)
 		return -EINVAL;
 
+	if (bt->trace_state == Blktrace_running) {
+		bt->trace_state = Blktrace_stopped;
+		spin_lock_irq(&running_trace_lock);
+		list_del_init(&bt->running_list);
+		spin_unlock_irq(&running_trace_lock);
+		relay_flush(bt->rchan);
+	}
+
 	put_probe_ref();
 	synchronize_rcu();
 	blk_trace_free(bt);
@@ -1684,10 +1706,7 @@
 
 	blk_trace_setup_lba(bt, bdev);
 
-	ret = -EBUSY;
-	if (cmpxchg(&q->blk_trace, NULL, bt))
-		goto free_bt;
-
+	rcu_assign_pointer(q->blk_trace, bt);
 	get_probe_ref();
 	return 0;
 
@@ -1816,13 +1835,11 @@
 					 struct device_attribute *attr,
 					 char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
+	struct block_device *bdev = bdget_part(dev_to_part(dev));
 	struct request_queue *q;
-	struct block_device *bdev;
 	struct blk_trace *bt;
 	ssize_t ret = -ENXIO;
 
-	bdev = bdget(part_devt(p));
 	if (bdev == NULL)
 		goto out;
 
@@ -1830,10 +1847,10 @@
 	if (q == NULL)
 		goto out_bdput;
 
-	mutex_lock(&q->blk_trace_mutex);
+	mutex_lock(&q->debugfs_mutex);
 
 	bt = rcu_dereference_protected(q->blk_trace,
-				       lockdep_is_held(&q->blk_trace_mutex));
+				       lockdep_is_held(&q->debugfs_mutex));
 	if (attr == &dev_attr_enable) {
 		ret = sprintf(buf, "%u\n", !!bt);
 		goto out_unlock_bdev;
@@ -1851,7 +1868,7 @@
 		ret = sprintf(buf, "%llu\n", bt->end_lba);
 
 out_unlock_bdev:
-	mutex_unlock(&q->blk_trace_mutex);
+	mutex_unlock(&q->debugfs_mutex);
 out_bdput:
 	bdput(bdev);
 out:
@@ -1864,7 +1881,6 @@
 {
 	struct block_device *bdev;
 	struct request_queue *q;
-	struct hd_struct *p;
 	struct blk_trace *bt;
 	u64 value;
 	ssize_t ret = -EINVAL;
@@ -1884,9 +1900,7 @@
 		goto out;
 
 	ret = -ENXIO;
-
-	p = dev_to_part(dev);
-	bdev = bdget(part_devt(p));
+	bdev = bdget_part(dev_to_part(dev));
 	if (bdev == NULL)
 		goto out;
 
@@ -1894,10 +1908,10 @@
 	if (q == NULL)
 		goto out_bdput;
 
-	mutex_lock(&q->blk_trace_mutex);
+	mutex_lock(&q->debugfs_mutex);
 
 	bt = rcu_dereference_protected(q->blk_trace,
-				       lockdep_is_held(&q->blk_trace_mutex));
+				       lockdep_is_held(&q->debugfs_mutex));
 	if (attr == &dev_attr_enable) {
 		if (!!value == !!bt) {
 			ret = 0;
@@ -1914,7 +1928,7 @@
 	if (bt == NULL) {
 		ret = blk_trace_setup_queue(q, bdev);
 		bt = rcu_dereference_protected(q->blk_trace,
-				lockdep_is_held(&q->blk_trace_mutex));
+				lockdep_is_held(&q->debugfs_mutex));
 	}
 
 	if (ret == 0) {
@@ -1929,7 +1943,7 @@
 	}
 
 out_unlock_bdev:
-	mutex_unlock(&q->blk_trace_mutex);
+	mutex_unlock(&q->debugfs_mutex);
 out_bdput:
 	bdput(bdev);
 out:
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 4d9f818..a9e0747 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -7,18 +7,27 @@
 #include <linux/slab.h>
 #include <linux/bpf.h>
 #include <linux/bpf_perf_event.h>
+#include <linux/btf.h>
 #include <linux/filter.h>
 #include <linux/uaccess.h>
 #include <linux/ctype.h>
 #include <linux/kprobes.h>
+#include <linux/spinlock.h>
 #include <linux/syscalls.h>
 #include <linux/error-injection.h>
+#include <linux/btf_ids.h>
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/btf.h>
 
 #include <asm/tlb.h>
 
 #include "trace_probe.h"
 #include "trace.h"
 
+#define CREATE_TRACE_POINTS
+#include "bpf_trace.h"
+
 #define bpf_event_rcu_dereference(p)					\
 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
 
@@ -62,6 +71,10 @@
 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 
+static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
+				  u64 flags, const struct btf **btf,
+				  s32 *btf_id);
+
 /**
  * trace_call_bpf - invoke BPF program
  * @call: tracepoint event
@@ -80,10 +93,7 @@
 {
 	unsigned int ret;
 
-	if (in_nmi()) /* not supported yet */
-		return 1;
-
-	preempt_disable();
+	cant_sleep();
 
 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
 		/*
@@ -115,11 +125,9 @@
 
  out:
 	__this_cpu_dec(bpf_prog_active);
-	preempt_enable();
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(trace_call_bpf);
 
 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
@@ -138,24 +146,25 @@
 };
 #endif
 
-BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
+static __always_inline int
+bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
 {
 	int ret;
 
-	ret = security_locked_down(LOCKDOWN_BPF_READ);
-	if (ret < 0)
-		goto out;
-
-	ret = probe_kernel_read(dst, unsafe_ptr, size);
+	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
 	if (unlikely(ret < 0))
-out:
 		memset(dst, 0, size);
-
 	return ret;
 }
 
-static const struct bpf_func_proto bpf_probe_read_proto = {
-	.func		= bpf_probe_read,
+BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
+	   const void __user *, unsafe_ptr)
+{
+	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
+}
+
+const struct bpf_func_proto bpf_probe_read_user_proto = {
+	.func		= bpf_probe_read_user,
 	.gpl_only	= true,
 	.ret_type	= RET_INTEGER,
 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
@@ -163,6 +172,144 @@
 	.arg3_type	= ARG_ANYTHING,
 };
 
+static __always_inline int
+bpf_probe_read_user_str_common(void *dst, u32 size,
+			       const void __user *unsafe_ptr)
+{
+	int ret;
+
+	/*
+	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
+	 * terminator into `dst`.
+	 *
+	 * strncpy_from_user() does long-sized strides in the fast path. If the
+	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
+	 * then there could be junk after the NUL in `dst`. If user takes `dst`
+	 * and keys a hash map with it, then semantically identical strings can
+	 * occupy multiple entries in the map.
+	 */
+	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
+	if (unlikely(ret < 0))
+		memset(dst, 0, size);
+	return ret;
+}
+
+BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
+	   const void __user *, unsafe_ptr)
+{
+	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
+}
+
+const struct bpf_func_proto bpf_probe_read_user_str_proto = {
+	.func		= bpf_probe_read_user_str,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+static __always_inline int
+bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
+{
+	int ret;
+
+	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
+	if (unlikely(ret < 0))
+		memset(dst, 0, size);
+	return ret;
+}
+
+BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
+	   const void *, unsafe_ptr)
+{
+	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
+}
+
+const struct bpf_func_proto bpf_probe_read_kernel_proto = {
+	.func		= bpf_probe_read_kernel,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+static __always_inline int
+bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
+{
+	int ret;
+
+	/*
+	 * The strncpy_from_kernel_nofault() call will likely not fill the
+	 * entire buffer, but that's okay in this circumstance as we're probing
+	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
+	 * as well probe the stack. Thus, memory is explicitly cleared
+	 * only in error case, so that improper users ignoring return
+	 * code altogether don't copy garbage; otherwise length of string
+	 * is returned that can be used for bpf_perf_event_output() et al.
+	 */
+	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
+	if (unlikely(ret < 0))
+		memset(dst, 0, size);
+	return ret;
+}
+
+BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
+	   const void *, unsafe_ptr)
+{
+	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
+}
+
+const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
+	.func		= bpf_probe_read_kernel_str,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
+	   const void *, unsafe_ptr)
+{
+	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
+		return bpf_probe_read_user_common(dst, size,
+				(__force void __user *)unsafe_ptr);
+	}
+	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
+}
+
+static const struct bpf_func_proto bpf_probe_read_compat_proto = {
+	.func		= bpf_probe_read_compat,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
+	   const void *, unsafe_ptr)
+{
+	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
+		return bpf_probe_read_user_str_common(dst, size,
+				(__force void __user *)unsafe_ptr);
+	}
+	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
+}
+
+static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
+	.func		= bpf_probe_read_compat_str,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
+
 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
 	   u32, size)
 {
@@ -187,7 +334,7 @@
 	if (unlikely(!nmi_uaccess_okay()))
 		return -EPERM;
 
-	return probe_user_write(unsafe_ptr, src, size);
+	return copy_to_user_nofault(unsafe_ptr, src, size);
 }
 
 static const struct bpf_func_proto bpf_probe_write_user_proto = {
@@ -201,25 +348,75 @@
 
 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
 {
+	if (!capable(CAP_SYS_ADMIN))
+		return NULL;
+
 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
 			    current->comm, task_pid_nr(current));
 
 	return &bpf_probe_write_user_proto;
 }
 
+static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
+		size_t bufsz)
+{
+	void __user *user_ptr = (__force void __user *)unsafe_ptr;
+
+	buf[0] = 0;
+
+	switch (fmt_ptype) {
+	case 's':
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
+			strncpy_from_user_nofault(buf, user_ptr, bufsz);
+			break;
+		}
+		fallthrough;
+#endif
+	case 'k':
+		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
+		break;
+	case 'u':
+		strncpy_from_user_nofault(buf, user_ptr, bufsz);
+		break;
+	}
+}
+
+static DEFINE_RAW_SPINLOCK(trace_printk_lock);
+
+#define BPF_TRACE_PRINTK_SIZE   1024
+
+static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
+{
+	static char buf[BPF_TRACE_PRINTK_SIZE];
+	unsigned long flags;
+	va_list ap;
+	int ret;
+
+	raw_spin_lock_irqsave(&trace_printk_lock, flags);
+	va_start(ap, fmt);
+	ret = vsnprintf(buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+	/* vsnprintf() will not append null for zero-length strings */
+	if (ret == 0)
+		buf[0] = '\0';
+	trace_bpf_trace_printk(buf);
+	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
+
+	return ret;
+}
+
 /*
  * Only limited trace_printk() conversion specifiers allowed:
- * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s
+ * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
  */
 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
 	   u64, arg2, u64, arg3)
 {
+	int i, mod[3] = {}, fmt_cnt = 0;
+	char buf[64], fmt_ptype;
+	void *unsafe_ptr = NULL;
 	bool str_seen = false;
-	int mod[3] = {};
-	int fmt_cnt = 0;
-	u64 unsafe_addr;
-	char buf[64];
-	int i;
 
 	/*
 	 * bpf_check()->check_func_arg()->check_stack_boundary()
@@ -245,40 +442,60 @@
 		if (fmt[i] == 'l') {
 			mod[fmt_cnt]++;
 			i++;
-		} else if (fmt[i] == 'p' || fmt[i] == 's') {
+		} else if (fmt[i] == 'p') {
 			mod[fmt_cnt]++;
+			if ((fmt[i + 1] == 'k' ||
+			     fmt[i + 1] == 'u') &&
+			    fmt[i + 2] == 's') {
+				fmt_ptype = fmt[i + 1];
+				i += 2;
+				goto fmt_str;
+			}
+
+			if (fmt[i + 1] == 'B') {
+				i++;
+				goto fmt_next;
+			}
+
 			/* disallow any further format extensions */
 			if (fmt[i + 1] != 0 &&
 			    !isspace(fmt[i + 1]) &&
 			    !ispunct(fmt[i + 1]))
 				return -EINVAL;
-			fmt_cnt++;
-			if (fmt[i] == 's') {
-				if (str_seen)
-					/* allow only one '%s' per fmt string */
-					return -EINVAL;
-				str_seen = true;
 
-				switch (fmt_cnt) {
-				case 1:
-					unsafe_addr = arg1;
-					arg1 = (long) buf;
-					break;
-				case 2:
-					unsafe_addr = arg2;
-					arg2 = (long) buf;
-					break;
-				case 3:
-					unsafe_addr = arg3;
-					arg3 = (long) buf;
-					break;
-				}
-				buf[0] = 0;
-				strncpy_from_unsafe(buf,
-						    (void *) (long) unsafe_addr,
-						    sizeof(buf));
+			goto fmt_next;
+		} else if (fmt[i] == 's') {
+			mod[fmt_cnt]++;
+			fmt_ptype = fmt[i];
+fmt_str:
+			if (str_seen)
+				/* allow only one '%s' per fmt string */
+				return -EINVAL;
+			str_seen = true;
+
+			if (fmt[i + 1] != 0 &&
+			    !isspace(fmt[i + 1]) &&
+			    !ispunct(fmt[i + 1]))
+				return -EINVAL;
+
+			switch (fmt_cnt) {
+			case 0:
+				unsafe_ptr = (void *)(long)arg1;
+				arg1 = (long)buf;
+				break;
+			case 1:
+				unsafe_ptr = (void *)(long)arg2;
+				arg2 = (long)buf;
+				break;
+			case 2:
+				unsafe_ptr = (void *)(long)arg3;
+				arg3 = (long)buf;
+				break;
 			}
-			continue;
+
+			bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
+					sizeof(buf));
+			goto fmt_next;
 		}
 
 		if (fmt[i] == 'l') {
@@ -289,6 +506,7 @@
 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
 		    fmt[i] != 'u' && fmt[i] != 'x')
 			return -EINVAL;
+fmt_next:
 		fmt_cnt++;
 	}
 
@@ -297,8 +515,7 @@
  */
 #define __BPF_TP_EMIT()	__BPF_ARG3_TP()
 #define __BPF_TP(...)							\
-	__trace_printk(0 /* Fake ip */,					\
-		       fmt, ##__VA_ARGS__)
+	bpf_do_trace_printk(fmt, ##__VA_ARGS__)
 
 #define __BPF_ARG1_TP(...)						\
 	((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))	\
@@ -335,14 +552,254 @@
 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
 {
 	/*
-	 * this program might be calling bpf_trace_printk,
-	 * so allocate per-cpu printk buffers
+	 * This program might be calling bpf_trace_printk,
+	 * so enable the associated bpf_trace/bpf_trace_printk event.
+	 * Repeat this each time as it is possible a user has
+	 * disabled bpf_trace_printk events.  By loading a program
+	 * calling bpf_trace_printk() however the user has expressed
+	 * the intent to see such events.
 	 */
-	trace_printk_init_buffers();
+	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
+		pr_warn_ratelimited("could not enable bpf_trace_printk events");
 
 	return &bpf_trace_printk_proto;
 }
 
+#define MAX_SEQ_PRINTF_VARARGS		12
+#define MAX_SEQ_PRINTF_MAX_MEMCPY	6
+#define MAX_SEQ_PRINTF_STR_LEN		128
+
+struct bpf_seq_printf_buf {
+	char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
+};
+static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
+static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
+
+BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
+	   const void *, data, u32, data_len)
+{
+	int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
+	int i, buf_used, copy_size, num_args;
+	u64 params[MAX_SEQ_PRINTF_VARARGS];
+	struct bpf_seq_printf_buf *bufs;
+	const u64 *args = data;
+
+	buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
+	if (WARN_ON_ONCE(buf_used > 1)) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	bufs = this_cpu_ptr(&bpf_seq_printf_buf);
+
+	/*
+	 * bpf_check()->check_func_arg()->check_stack_boundary()
+	 * guarantees that fmt points to bpf program stack,
+	 * fmt_size bytes of it were initialized and fmt_size > 0
+	 */
+	if (fmt[--fmt_size] != 0)
+		goto out;
+
+	if (data_len & 7)
+		goto out;
+
+	for (i = 0; i < fmt_size; i++) {
+		if (fmt[i] == '%') {
+			if (fmt[i + 1] == '%')
+				i++;
+			else if (!data || !data_len)
+				goto out;
+		}
+	}
+
+	num_args = data_len / 8;
+
+	/* check format string for allowed specifiers */
+	for (i = 0; i < fmt_size; i++) {
+		/* only printable ascii for now. */
+		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (fmt[i] != '%')
+			continue;
+
+		if (fmt[i + 1] == '%') {
+			i++;
+			continue;
+		}
+
+		if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
+			err = -E2BIG;
+			goto out;
+		}
+
+		if (fmt_cnt >= num_args) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
+		i++;
+
+		/* skip optional "[0 +-][num]" width formating field */
+		while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
+		       fmt[i] == ' ')
+			i++;
+		if (fmt[i] >= '1' && fmt[i] <= '9') {
+			i++;
+			while (fmt[i] >= '0' && fmt[i] <= '9')
+				i++;
+		}
+
+		if (fmt[i] == 's') {
+			void *unsafe_ptr;
+
+			/* try our best to copy */
+			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
+				err = -E2BIG;
+				goto out;
+			}
+
+			unsafe_ptr = (void *)(long)args[fmt_cnt];
+			err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
+					unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
+			if (err < 0)
+				bufs->buf[memcpy_cnt][0] = '\0';
+			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
+
+			fmt_cnt++;
+			memcpy_cnt++;
+			continue;
+		}
+
+		if (fmt[i] == 'p') {
+			if (fmt[i + 1] == 0 ||
+			    fmt[i + 1] == 'K' ||
+			    fmt[i + 1] == 'x' ||
+			    fmt[i + 1] == 'B') {
+				/* just kernel pointers */
+				params[fmt_cnt] = args[fmt_cnt];
+				fmt_cnt++;
+				continue;
+			}
+
+			/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
+			if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
+				err = -EINVAL;
+				goto out;
+			}
+			if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
+				err = -EINVAL;
+				goto out;
+			}
+
+			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
+				err = -E2BIG;
+				goto out;
+			}
+
+
+			copy_size = (fmt[i + 2] == '4') ? 4 : 16;
+
+			err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
+						(void *) (long) args[fmt_cnt],
+						copy_size);
+			if (err < 0)
+				memset(bufs->buf[memcpy_cnt], 0, copy_size);
+			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
+
+			i += 2;
+			fmt_cnt++;
+			memcpy_cnt++;
+			continue;
+		}
+
+		if (fmt[i] == 'l') {
+			i++;
+			if (fmt[i] == 'l')
+				i++;
+		}
+
+		if (fmt[i] != 'i' && fmt[i] != 'd' &&
+		    fmt[i] != 'u' && fmt[i] != 'x' &&
+		    fmt[i] != 'X') {
+			err = -EINVAL;
+			goto out;
+		}
+
+		params[fmt_cnt] = args[fmt_cnt];
+		fmt_cnt++;
+	}
+
+	/* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
+	 * all of them to seq_printf().
+	 */
+	seq_printf(m, fmt, params[0], params[1], params[2], params[3],
+		   params[4], params[5], params[6], params[7], params[8],
+		   params[9], params[10], params[11]);
+
+	err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
+out:
+	this_cpu_dec(bpf_seq_printf_buf_used);
+	return err;
+}
+
+BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
+
+static const struct bpf_func_proto bpf_seq_printf_proto = {
+	.func		= bpf_seq_printf,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &btf_seq_file_ids[0],
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+	.arg4_type      = ARG_PTR_TO_MEM_OR_NULL,
+	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
+};
+
+BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
+{
+	return seq_write(m, data, len) ? -EOVERFLOW : 0;
+}
+
+static const struct bpf_func_proto bpf_seq_write_proto = {
+	.func		= bpf_seq_write,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &btf_seq_file_ids[0],
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+};
+
+BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
+	   u32, btf_ptr_size, u64, flags)
+{
+	const struct btf *btf;
+	s32 btf_id;
+	int ret;
+
+	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
+	if (ret)
+		return ret;
+
+	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
+}
+
+static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
+	.func		= bpf_seq_printf_btf,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &btf_seq_file_ids[0],
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
 static __always_inline int
 get_map_perf_counter(struct bpf_map *map, u64 flags,
 		     u64 *value, u64 *enabled, u64 *running)
@@ -554,7 +1011,7 @@
 	return (long) current;
 }
 
-static const struct bpf_func_proto bpf_get_current_task_proto = {
+const struct bpf_func_proto bpf_get_current_task_proto = {
 	.func		= bpf_get_current_task,
 	.gpl_only	= true,
 	.ret_type	= RET_INTEGER,
@@ -583,45 +1040,11 @@
 	.arg2_type      = ARG_ANYTHING,
 };
 
-BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size,
-	   const void *, unsafe_ptr)
-{
-	int ret;
-
-	ret = security_locked_down(LOCKDOWN_BPF_READ);
-	if (ret < 0)
-		goto out;
-
-	/*
-	 * The strncpy_from_unsafe() call will likely not fill the entire
-	 * buffer, but that's okay in this circumstance as we're probing
-	 * arbitrary memory anyway similar to bpf_probe_read() and might
-	 * as well probe the stack. Thus, memory is explicitly cleared
-	 * only in error case, so that improper users ignoring return
-	 * code altogether don't copy garbage; otherwise length of string
-	 * is returned that can be used for bpf_perf_event_output() et al.
-	 */
-	ret = strncpy_from_unsafe(dst, unsafe_ptr, size);
-	if (unlikely(ret < 0))
-out:
-		memset(dst, 0, size);
-
-	return ret;
-}
-
-static const struct bpf_func_proto bpf_probe_read_str_proto = {
-	.func		= bpf_probe_read_str,
-	.gpl_only	= true,
-	.ret_type	= RET_INTEGER,
-	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
-	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
-	.arg3_type	= ARG_ANYTHING,
-};
-
 struct send_signal_irq_work {
 	struct irq_work irq_work;
 	struct task_struct *task;
 	u32 sig;
+	enum pid_type type;
 };
 
 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
@@ -631,10 +1054,10 @@
 	struct send_signal_irq_work *work;
 
 	work = container_of(entry, struct send_signal_irq_work, irq_work);
-	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, PIDTYPE_TGID);
+	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
 }
 
-BPF_CALL_1(bpf_send_signal, u32, sig)
+static int bpf_send_signal_common(u32 sig, enum pid_type type)
 {
 	struct send_signal_irq_work *work = NULL;
 
@@ -658,7 +1081,7 @@
 			return -EINVAL;
 
 		work = this_cpu_ptr(&send_signal_work);
-		if (work->irq_work.flags & IRQ_WORK_BUSY)
+		if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
 			return -EBUSY;
 
 		/* Add the current task, which is the target of sending signal,
@@ -667,11 +1090,17 @@
 		 */
 		work->task = current;
 		work->sig = sig;
+		work->type = type;
 		irq_work_queue(&work->irq_work);
 		return 0;
 	}
 
-	return group_send_sig_info(sig, SEND_SIG_PRIV, current, PIDTYPE_TGID);
+	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
+}
+
+BPF_CALL_1(bpf_send_signal, u32, sig)
+{
+	return bpf_send_signal_common(sig, PIDTYPE_TGID);
 }
 
 static const struct bpf_func_proto bpf_send_signal_proto = {
@@ -681,8 +1110,132 @@
 	.arg1_type	= ARG_ANYTHING,
 };
 
-static const struct bpf_func_proto *
-tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+BPF_CALL_1(bpf_send_signal_thread, u32, sig)
+{
+	return bpf_send_signal_common(sig, PIDTYPE_PID);
+}
+
+static const struct bpf_func_proto bpf_send_signal_thread_proto = {
+	.func		= bpf_send_signal_thread,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
+{
+	long len;
+	char *p;
+
+	if (!sz)
+		return 0;
+
+	p = d_path(path, buf, sz);
+	if (IS_ERR(p)) {
+		len = PTR_ERR(p);
+	} else {
+		len = buf + sz - p;
+		memmove(buf, p, len);
+	}
+
+	return len;
+}
+
+BTF_SET_START(btf_allowlist_d_path)
+#ifdef CONFIG_SECURITY
+BTF_ID(func, security_file_permission)
+BTF_ID(func, security_inode_getattr)
+BTF_ID(func, security_file_open)
+#endif
+#ifdef CONFIG_SECURITY_PATH
+BTF_ID(func, security_path_truncate)
+#endif
+BTF_ID(func, vfs_truncate)
+BTF_ID(func, vfs_fallocate)
+BTF_ID(func, dentry_open)
+BTF_ID(func, vfs_getattr)
+BTF_ID(func, filp_close)
+BTF_SET_END(btf_allowlist_d_path)
+
+static bool bpf_d_path_allowed(const struct bpf_prog *prog)
+{
+	return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id);
+}
+
+BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
+
+static const struct bpf_func_proto bpf_d_path_proto = {
+	.func		= bpf_d_path,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.allowed	= bpf_d_path_allowed,
+};
+
+#define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
+			 BTF_F_PTR_RAW | BTF_F_ZERO)
+
+static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
+				  u64 flags, const struct btf **btf,
+				  s32 *btf_id)
+{
+	const struct btf_type *t;
+
+	if (unlikely(flags & ~(BTF_F_ALL)))
+		return -EINVAL;
+
+	if (btf_ptr_size != sizeof(struct btf_ptr))
+		return -EINVAL;
+
+	*btf = bpf_get_btf_vmlinux();
+
+	if (IS_ERR_OR_NULL(*btf))
+		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
+
+	if (ptr->type_id > 0)
+		*btf_id = ptr->type_id;
+	else
+		return -EINVAL;
+
+	if (*btf_id > 0)
+		t = btf_type_by_id(*btf, *btf_id);
+	if (*btf_id <= 0 || !t)
+		return -ENOENT;
+
+	return 0;
+}
+
+BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
+	   u32, btf_ptr_size, u64, flags)
+{
+	const struct btf *btf;
+	s32 btf_id;
+	int ret;
+
+	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
+	if (ret)
+		return ret;
+
+	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
+				      flags);
+}
+
+const struct bpf_func_proto bpf_snprintf_btf_proto = {
+	.func		= bpf_snprintf_btf,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_MEM,
+	.arg2_type	= ARG_CONST_SIZE,
+	.arg3_type	= ARG_PTR_TO_MEM,
+	.arg4_type	= ARG_CONST_SIZE,
+	.arg5_type	= ARG_ANYTHING,
+};
+
+const struct bpf_func_proto *
+bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
 	switch (func_id) {
 	case BPF_FUNC_map_lookup_elem:
@@ -697,10 +1250,10 @@
 		return &bpf_map_pop_elem_proto;
 	case BPF_FUNC_map_peek_elem:
 		return &bpf_map_peek_elem_proto;
-	case BPF_FUNC_probe_read:
-		return &bpf_probe_read_proto;
 	case BPF_FUNC_ktime_get_ns:
 		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_boot_ns:
+		return &bpf_ktime_get_boot_ns_proto;
 	case BPF_FUNC_tail_call:
 		return &bpf_tail_call_proto;
 	case BPF_FUNC_get_current_pid_tgid:
@@ -719,20 +1272,65 @@
 		return &bpf_get_numa_node_id_proto;
 	case BPF_FUNC_perf_event_read:
 		return &bpf_perf_event_read_proto;
-	case BPF_FUNC_probe_write_user:
-		return bpf_get_probe_write_proto();
 	case BPF_FUNC_current_task_under_cgroup:
 		return &bpf_current_task_under_cgroup_proto;
 	case BPF_FUNC_get_prandom_u32:
 		return &bpf_get_prandom_u32_proto;
+	case BPF_FUNC_probe_write_user:
+		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
+		       NULL : bpf_get_probe_write_proto();
+	case BPF_FUNC_probe_read_user:
+		return &bpf_probe_read_user_proto;
+	case BPF_FUNC_probe_read_kernel:
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_kernel_proto;
+	case BPF_FUNC_probe_read_user_str:
+		return &bpf_probe_read_user_str_proto;
+	case BPF_FUNC_probe_read_kernel_str:
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_kernel_str_proto;
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	case BPF_FUNC_probe_read:
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_compat_proto;
 	case BPF_FUNC_probe_read_str:
-		return &bpf_probe_read_str_proto;
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_compat_str_proto;
+#endif
 #ifdef CONFIG_CGROUPS
 	case BPF_FUNC_get_current_cgroup_id:
 		return &bpf_get_current_cgroup_id_proto;
 #endif
 	case BPF_FUNC_send_signal:
 		return &bpf_send_signal_proto;
+	case BPF_FUNC_send_signal_thread:
+		return &bpf_send_signal_thread_proto;
+	case BPF_FUNC_perf_event_read_value:
+		return &bpf_perf_event_read_value_proto;
+	case BPF_FUNC_get_ns_current_pid_tgid:
+		return &bpf_get_ns_current_pid_tgid_proto;
+	case BPF_FUNC_ringbuf_output:
+		return &bpf_ringbuf_output_proto;
+	case BPF_FUNC_ringbuf_reserve:
+		return &bpf_ringbuf_reserve_proto;
+	case BPF_FUNC_ringbuf_submit:
+		return &bpf_ringbuf_submit_proto;
+	case BPF_FUNC_ringbuf_discard:
+		return &bpf_ringbuf_discard_proto;
+	case BPF_FUNC_ringbuf_query:
+		return &bpf_ringbuf_query_proto;
+	case BPF_FUNC_jiffies64:
+		return &bpf_jiffies64_proto;
+	case BPF_FUNC_get_task_stack:
+		return &bpf_get_task_stack_proto;
+	case BPF_FUNC_copy_from_user:
+		return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
+	case BPF_FUNC_snprintf_btf:
+		return &bpf_snprintf_btf_proto;
+	case BPF_FUNC_per_cpu_ptr:
+		return &bpf_per_cpu_ptr_proto;
+	case BPF_FUNC_this_cpu_ptr:
+		return &bpf_this_cpu_ptr_proto;
 	default:
 		return NULL;
 	}
@@ -748,14 +1346,12 @@
 		return &bpf_get_stackid_proto;
 	case BPF_FUNC_get_stack:
 		return &bpf_get_stack_proto;
-	case BPF_FUNC_perf_event_read_value:
-		return &bpf_perf_event_read_value_proto;
 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
 	case BPF_FUNC_override_return:
 		return &bpf_override_return_proto;
 #endif
 	default:
-		return tracing_func_proto(func_id, prog);
+		return bpf_tracing_func_proto(func_id, prog);
 	}
 }
 
@@ -865,7 +1461,7 @@
 	case BPF_FUNC_get_stack:
 		return &bpf_get_stack_proto_tp;
 	default:
-		return tracing_func_proto(func_id, prog);
+		return bpf_tracing_func_proto(func_id, prog);
 	}
 }
 
@@ -918,6 +1514,41 @@
          .arg3_type      = ARG_CONST_SIZE,
 };
 
+BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
+	   void *, buf, u32, size, u64, flags)
+{
+	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
+	struct perf_branch_stack *br_stack = ctx->data->br_stack;
+	u32 to_copy;
+
+	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
+		return -EINVAL;
+
+	if (unlikely(!br_stack))
+		return -ENOENT;
+
+	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
+		return br_stack->nr * br_entry_size;
+
+	if (!buf || (size % br_entry_size != 0))
+		return -EINVAL;
+
+	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
+	memcpy(buf, br_stack->entries, to_copy);
+
+	return to_copy;
+}
+
+static const struct bpf_func_proto bpf_read_branch_records_proto = {
+	.func           = bpf_read_branch_records,
+	.gpl_only       = true,
+	.ret_type       = RET_INTEGER,
+	.arg1_type      = ARG_PTR_TO_CTX,
+	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
+	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type      = ARG_ANYTHING,
+};
+
 static const struct bpf_func_proto *
 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -925,13 +1556,15 @@
 	case BPF_FUNC_perf_event_output:
 		return &bpf_perf_event_output_proto_tp;
 	case BPF_FUNC_get_stackid:
-		return &bpf_get_stackid_proto_tp;
+		return &bpf_get_stackid_proto_pe;
 	case BPF_FUNC_get_stack:
-		return &bpf_get_stack_proto_tp;
+		return &bpf_get_stack_proto_pe;
 	case BPF_FUNC_perf_prog_read_value:
 		return &bpf_perf_prog_read_value_proto;
+	case BPF_FUNC_read_branch_records:
+		return &bpf_read_branch_records_proto;
 	default:
-		return tracing_func_proto(func_id, prog);
+		return bpf_tracing_func_proto(func_id, prog);
 	}
 }
 
@@ -993,6 +1626,9 @@
 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
 };
 
+extern const struct bpf_func_proto bpf_skb_output_proto;
+extern const struct bpf_func_proto bpf_xdp_output_proto;
+
 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
 	   struct bpf_map *, map, u64, flags)
 {
@@ -1056,7 +1692,46 @@
 	case BPF_FUNC_get_stack:
 		return &bpf_get_stack_proto_raw_tp;
 	default:
-		return tracing_func_proto(func_id, prog);
+		return bpf_tracing_func_proto(func_id, prog);
+	}
+}
+
+const struct bpf_func_proto *
+tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+#ifdef CONFIG_NET
+	case BPF_FUNC_skb_output:
+		return &bpf_skb_output_proto;
+	case BPF_FUNC_xdp_output:
+		return &bpf_xdp_output_proto;
+	case BPF_FUNC_skc_to_tcp6_sock:
+		return &bpf_skc_to_tcp6_sock_proto;
+	case BPF_FUNC_skc_to_tcp_sock:
+		return &bpf_skc_to_tcp_sock_proto;
+	case BPF_FUNC_skc_to_tcp_timewait_sock:
+		return &bpf_skc_to_tcp_timewait_sock_proto;
+	case BPF_FUNC_skc_to_tcp_request_sock:
+		return &bpf_skc_to_tcp_request_sock_proto;
+	case BPF_FUNC_skc_to_udp6_sock:
+		return &bpf_skc_to_udp6_sock_proto;
+#endif
+	case BPF_FUNC_seq_printf:
+		return prog->expected_attach_type == BPF_TRACE_ITER ?
+		       &bpf_seq_printf_proto :
+		       NULL;
+	case BPF_FUNC_seq_write:
+		return prog->expected_attach_type == BPF_TRACE_ITER ?
+		       &bpf_seq_write_proto :
+		       NULL;
+	case BPF_FUNC_seq_printf_btf:
+		return prog->expected_attach_type == BPF_TRACE_ITER ?
+		       &bpf_seq_printf_btf_proto :
+		       NULL;
+	case BPF_FUNC_d_path:
+		return &bpf_d_path_proto;
+	default:
+		return raw_tp_prog_func_proto(func_id, prog);
 	}
 }
 
@@ -1065,8 +1740,7 @@
 					const struct bpf_prog *prog,
 					struct bpf_insn_access_aux *info)
 {
-	/* largest tracepoint in the kernel has 12 args */
-	if (off < 0 || off >= sizeof(__u64) * 12)
+	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
 		return false;
 	if (type != BPF_READ)
 		return false;
@@ -1075,12 +1749,45 @@
 	return true;
 }
 
+static bool tracing_prog_is_valid_access(int off, int size,
+					 enum bpf_access_type type,
+					 const struct bpf_prog *prog,
+					 struct bpf_insn_access_aux *info)
+{
+	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
+		return false;
+	if (type != BPF_READ)
+		return false;
+	if (off % size != 0)
+		return false;
+	return btf_ctx_access(off, size, type, prog, info);
+}
+
+int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
+				     const union bpf_attr *kattr,
+				     union bpf_attr __user *uattr)
+{
+	return -ENOTSUPP;
+}
+
 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
 	.get_func_proto  = raw_tp_prog_func_proto,
 	.is_valid_access = raw_tp_prog_is_valid_access,
 };
 
 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
+#ifdef CONFIG_NET
+	.test_run = bpf_prog_test_run_raw_tp,
+#endif
+};
+
+const struct bpf_verifier_ops tracing_verifier_ops = {
+	.get_func_proto  = tracing_prog_func_proto,
+	.is_valid_access = tracing_prog_is_valid_access,
+};
+
+const struct bpf_prog_ops tracing_prog_ops = {
+	.test_run = bpf_prog_test_run_tracing,
 };
 
 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
@@ -1270,7 +1977,7 @@
 	u32 *ids, prog_cnt, ids_len;
 	int ret;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EPERM;
 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
 		return -EINVAL;
@@ -1331,10 +2038,9 @@
 static __always_inline
 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
 {
+	cant_sleep();
 	rcu_read_lock();
-	preempt_disable();
 	(void) BPF_PROG_RUN(prog, args);
-	preempt_enable();
 	rcu_read_unlock();
 }
 
@@ -1478,10 +2184,11 @@
 {
 	struct bpf_trace_module *btm, *tmp;
 	struct module *mod = module;
+	int ret = 0;
 
 	if (mod->num_bpf_raw_events == 0 ||
 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
-		return 0;
+		goto out;
 
 	mutex_lock(&bpf_module_mutex);
 
@@ -1491,6 +2198,8 @@
 		if (btm) {
 			btm->module = module;
 			list_add(&btm->list, &bpf_trace_modules);
+		} else {
+			ret = -ENOMEM;
 		}
 		break;
 	case MODULE_STATE_GOING:
@@ -1506,7 +2215,8 @@
 
 	mutex_unlock(&bpf_module_mutex);
 
-	return 0;
+out:
+	return notifier_from_errno(ret);
 }
 
 static struct notifier_block bpf_module_nb = {
diff --git a/kernel/trace/bpf_trace.h b/kernel/trace/bpf_trace.h
new file mode 100644
index 0000000..9acbc11
--- /dev/null
+++ b/kernel/trace/bpf_trace.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM bpf_trace
+
+#if !defined(_TRACE_BPF_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+
+#define _TRACE_BPF_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(bpf_trace_printk,
+
+	TP_PROTO(const char *bpf_string),
+
+	TP_ARGS(bpf_string),
+
+	TP_STRUCT__entry(
+		__string(bpf_string, bpf_string)
+	),
+
+	TP_fast_assign(
+		__assign_str(bpf_string, bpf_string);
+	),
+
+	TP_printk("%s", __get_str(bpf_string))
+);
+
+#endif /* _TRACE_BPF_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE bpf_trace
+
+#include <trace/define_trace.h>
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 888cd00..a58da91 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -96,11 +96,34 @@
 	return 0;
 }
 
+/*
+ * Not all archs define MCOUNT_INSN_SIZE which is used to look for direct
+ * functions. But those archs currently don't support direct functions
+ * anyway, and ftrace_find_rec_direct() is just a stub for them.
+ * Define MCOUNT_INSN_SIZE to keep those archs compiling.
+ */
+#ifndef MCOUNT_INSN_SIZE
+/* Make sure this only works without direct calls */
+# ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+#  error MCOUNT_INSN_SIZE not defined with direct calls enabled
+# endif
+# define MCOUNT_INSN_SIZE 0
+#endif
+
 int function_graph_enter(unsigned long ret, unsigned long func,
 			 unsigned long frame_pointer, unsigned long *retp)
 {
 	struct ftrace_graph_ent trace;
 
+	/*
+	 * Skip graph tracing if the return location is served by direct trampoline,
+	 * since call sequence and return addresses is unpredicatable anymore.
+	 * Ex: BPF trampoline may call original function and may skip frame
+	 * depending on type of BPF programs attached.
+	 */
+	if (ftrace_direct_func_count &&
+	    ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))
+		return -EBUSY;
 	trace.func = func;
 	trace.depth = ++current->curr_ret_depth;
 
@@ -332,9 +355,14 @@
 	return 0;
 }
 
+/*
+ * Simply points to ftrace_stub, but with the proper protocol.
+ * Defined by the linker script in linux/vmlinux.lds.h
+ */
+extern void ftrace_stub_graph(struct ftrace_graph_ret *);
+
 /* The callbacks that hook a function */
-trace_func_graph_ret_t ftrace_graph_return =
-			(trace_func_graph_ret_t)ftrace_stub;
+trace_func_graph_ret_t ftrace_graph_return = ftrace_stub_graph;
 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
 
@@ -359,8 +387,8 @@
 		}
 	}
 
-	read_lock(&tasklist_lock);
-	do_each_thread(g, t) {
+	rcu_read_lock();
+	for_each_process_thread(g, t) {
 		if (start == end) {
 			ret = -EAGAIN;
 			goto unlock;
@@ -374,10 +402,10 @@
 			smp_wmb();
 			t->ret_stack = ret_stack_list[start++];
 		}
-	} while_each_thread(g, t);
+	}
 
 unlock:
-	read_unlock(&tasklist_lock);
+	rcu_read_unlock();
 free:
 	for (i = start; i < end; i++)
 		kfree(ret_stack_list[i]);
@@ -612,7 +640,7 @@
 		goto out;
 
 	ftrace_graph_active--;
-	ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
+	ftrace_graph_return = ftrace_stub_graph;
 	ftrace_graph_entry = ftrace_graph_entry_stub;
 	__ftrace_graph_entry = ftrace_graph_entry_stub;
 	ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2b55016..4a5d35d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -62,8 +62,6 @@
 	})
 
 /* hash bits for specific function selection */
-#define FTRACE_HASH_BITS 7
-#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
 #define FTRACE_HASH_DEFAULT_BITS 10
 #define FTRACE_HASH_MAX_BITS 12
 
@@ -104,7 +102,7 @@
 
 	tr = ops->private;
 
-	return tr->function_pids != NULL;
+	return tr->function_pids != NULL || tr->function_no_pids != NULL;
 }
 
 static void ftrace_update_trampoline(struct ftrace_ops *ops);
@@ -145,24 +143,20 @@
 			    struct ftrace_ops *op, struct pt_regs *regs)
 {
 	struct trace_array *tr = op->private;
+	int pid;
 
-	if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
-		return;
+	if (tr) {
+		pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
+		if (pid == FTRACE_PID_IGNORE)
+			return;
+		if (pid != FTRACE_PID_TRACE &&
+		    pid != current->pid)
+			return;
+	}
 
 	op->saved_func(ip, parent_ip, op, regs);
 }
 
-static void ftrace_sync(struct work_struct *work)
-{
-	/*
-	 * This function is just a stub to implement a hard force
-	 * of synchronize_rcu(). This requires synchronizing
-	 * tasks even in userspace and idle.
-	 *
-	 * Yes, function tracing is rude.
-	 */
-}
-
 static void ftrace_sync_ipi(void *data)
 {
 	/* Probably not needed, but do it anyway */
@@ -236,7 +230,7 @@
 	/*
 	 * For static tracing, we need to be a bit more careful.
 	 * The function change takes affect immediately. Thus,
-	 * we need to coorditate the setting of the function_trace_ops
+	 * we need to coordinate the setting of the function_trace_ops
 	 * with the setting of the ftrace_trace_function.
 	 *
 	 * Set the function to the list ops, which will call the
@@ -248,7 +242,7 @@
 	 * Make sure all CPUs see this. Yes this is slow, but static
 	 * tracing is slow and nasty to have enabled.
 	 */
-	schedule_on_each_cpu(ftrace_sync);
+	synchronize_rcu_tasks_rude();
 	/* Now all cpus are using the list ops. */
 	function_trace_op = set_function_trace_op;
 	/* Make sure the function_trace_op is visible on all CPUs */
@@ -326,6 +320,8 @@
 	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
 		ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
 #endif
+	if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT))
+		return -EBUSY;
 
 	if (!core_kernel_data((unsigned long)ops))
 		ops->flags |= FTRACE_OPS_FL_DYNAMIC;
@@ -463,10 +459,10 @@
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 /* function graph compares on total time */
-static int function_stat_cmp(void *p1, void *p2)
+static int function_stat_cmp(const void *p1, const void *p2)
 {
-	struct ftrace_profile *a = p1;
-	struct ftrace_profile *b = p2;
+	const struct ftrace_profile *a = p1;
+	const struct ftrace_profile *b = p2;
 
 	if (a->time < b->time)
 		return -1;
@@ -477,10 +473,10 @@
 }
 #else
 /* not function graph compares against hits */
-static int function_stat_cmp(void *p1, void *p2)
+static int function_stat_cmp(const void *p1, const void *p2)
 {
-	struct ftrace_profile *a = p1;
-	struct ftrace_profile *b = p2;
+	const struct ftrace_profile *a = p1;
+	const struct ftrace_profile *b = p2;
 
 	if (a->counter < b->counter)
 		return -1;
@@ -1018,11 +1014,6 @@
 # error Dynamic ftrace depends on MCOUNT_RECORD
 #endif
 
-struct ftrace_func_entry {
-	struct hlist_node hlist;
-	unsigned long ip;
-};
-
 struct ftrace_func_probe {
 	struct ftrace_probe_ops	*probe_ops;
 	struct ftrace_ops	ops;
@@ -1106,9 +1097,6 @@
 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
 
-/* estimate from running different kernels */
-#define NR_TO_INIT		10000
-
 static struct ftrace_page	*ftrace_pages_start;
 static struct ftrace_page	*ftrace_pages;
 
@@ -1370,28 +1358,20 @@
 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
 				       struct ftrace_hash *new_hash);
 
-static struct ftrace_hash *
-__ftrace_hash_move(struct ftrace_hash *src)
+static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size)
 {
 	struct ftrace_func_entry *entry;
-	struct hlist_node *tn;
-	struct hlist_head *hhd;
 	struct ftrace_hash *new_hash;
-	int size = src->count;
+	struct hlist_head *hhd;
+	struct hlist_node *tn;
 	int bits = 0;
 	int i;
 
 	/*
-	 * If the new source is empty, just return the empty_hash.
+	 * Use around half the size (max bit of it), but
+	 * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits).
 	 */
-	if (ftrace_hash_empty(src))
-		return EMPTY_HASH;
-
-	/*
-	 * Make the hash size about 1/2 the # found
-	 */
-	for (size /= 2; size; size >>= 1)
-		bits++;
+	bits = fls(size / 2);
 
 	/* Don't allocate too much */
 	if (bits > FTRACE_HASH_MAX_BITS)
@@ -1411,10 +1391,23 @@
 			__add_hash_entry(new_hash, entry);
 		}
 	}
-
 	return new_hash;
 }
 
+static struct ftrace_hash *
+__ftrace_hash_move(struct ftrace_hash *src)
+{
+	int size = src->count;
+
+	/*
+	 * If the new source is empty, just return the empty_hash.
+	 */
+	if (ftrace_hash_empty(src))
+		return EMPTY_HASH;
+
+	return dup_hash(src, size);
+}
+
 static int
 ftrace_hash_move(struct ftrace_ops *ops, int enable,
 		 struct ftrace_hash **dst, struct ftrace_hash *src)
@@ -1458,7 +1451,7 @@
 {
 	/*
 	 * The function record is a match if it exists in the filter
-	 * hash and not in the notrace hash. Note, an emty hash is
+	 * hash and not in the notrace hash. Note, an empty hash is
 	 * considered a match for the filter hash, but an empty
 	 * notrace hash is considered not in the notrace hash.
 	 */
@@ -1534,6 +1527,28 @@
 	return 0;
 }
 
+static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
+{
+	struct ftrace_page *pg;
+	struct dyn_ftrace *rec = NULL;
+	struct dyn_ftrace key;
+
+	key.ip = start;
+	key.flags = end;	/* overload flags, as it is unsigned long */
+
+	for (pg = ftrace_pages_start; pg; pg = pg->next) {
+		if (end < pg->records[0].ip ||
+		    start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
+			continue;
+		rec = bsearch(&key, pg->records, pg->index,
+			      sizeof(struct dyn_ftrace),
+			      ftrace_cmp_recs);
+		if (rec)
+			break;
+	}
+	return rec;
+}
+
 /**
  * ftrace_location_range - return the first address of a traced location
  *	if it touches the given ip range
@@ -1548,23 +1563,11 @@
  */
 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
 {
-	struct ftrace_page *pg;
 	struct dyn_ftrace *rec;
-	struct dyn_ftrace key;
 
-	key.ip = start;
-	key.flags = end;	/* overload flags, as it is unsigned long */
-
-	for (pg = ftrace_pages_start; pg; pg = pg->next) {
-		if (end < pg->records[0].ip ||
-		    start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
-			continue;
-		rec = bsearch(&key, pg->records, pg->index,
-			      sizeof(struct dyn_ftrace),
-			      ftrace_cmp_recs);
-		if (rec)
-			return rec->ip;
-	}
+	rec = lookup_rec(start, end);
+	if (rec)
+		return rec->ip;
 
 	return 0;
 }
@@ -1717,6 +1720,9 @@
 			if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
 				return false;
 
+			if (ops->flags & FTRACE_OPS_FL_DIRECT)
+				rec->flags |= FTRACE_FL_DIRECT;
+
 			/*
 			 * If there's only a single callback registered to a
 			 * function, and the ops has a trampoline registered
@@ -1745,6 +1751,15 @@
 			rec->flags--;
 
 			/*
+			 * Only the internal direct_ops should have the
+			 * DIRECT flag set. Thus, if it is removing a
+			 * function, then that function should no longer
+			 * be direct.
+			 */
+			if (ops->flags & FTRACE_OPS_FL_DIRECT)
+				rec->flags &= ~FTRACE_FL_DIRECT;
+
+			/*
 			 * If the rec had REGS enabled and the ops that is
 			 * being removed had REGS set, then see if there is
 			 * still any ops for this record that wants regs.
@@ -1956,7 +1971,7 @@
 	char ins[MCOUNT_INSN_SIZE];
 	int i;
 
-	if (probe_kernel_read(ins, p, MCOUNT_INSN_SIZE)) {
+	if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) {
 		printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
 		return;
 	}
@@ -2006,16 +2021,16 @@
 {
 	unsigned long ip = rec ? rec->ip : 0;
 
+	pr_info("------------[ ftrace bug ]------------\n");
+
 	switch (failed) {
 	case -EFAULT:
-		FTRACE_WARN_ON_ONCE(1);
 		pr_info("ftrace faulted on modifying ");
-		print_ip_sym(ip);
+		print_ip_sym(KERN_INFO, ip);
 		break;
 	case -EINVAL:
-		FTRACE_WARN_ON_ONCE(1);
 		pr_info("ftrace failed to modify ");
-		print_ip_sym(ip);
+		print_ip_sym(KERN_INFO, ip);
 		print_ip_ins(" actual:   ", (unsigned char *)ip);
 		pr_cont("\n");
 		if (ftrace_expected) {
@@ -2024,14 +2039,12 @@
 		}
 		break;
 	case -EPERM:
-		FTRACE_WARN_ON_ONCE(1);
 		pr_info("ftrace faulted on writing ");
-		print_ip_sym(ip);
+		print_ip_sym(KERN_INFO, ip);
 		break;
 	default:
-		FTRACE_WARN_ON_ONCE(1);
 		pr_info("ftrace faulted on unknown error ");
-		print_ip_sym(ip);
+		print_ip_sym(KERN_INFO, ip);
 	}
 	print_bug_type();
 	if (rec) {
@@ -2056,6 +2069,8 @@
 		ip = ftrace_get_addr_curr(rec);
 		pr_cont("\n expected tramp: %lx\n", ip);
 	}
+
+	FTRACE_WARN_ON_ONCE(1);
 }
 
 static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
@@ -2085,15 +2100,34 @@
 	 * If enabling and the REGS flag does not match the REGS_EN, or
 	 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
 	 * this record. Set flags to fail the compare against ENABLED.
+	 * Same for direct calls.
 	 */
 	if (flag) {
-		if (!(rec->flags & FTRACE_FL_REGS) != 
+		if (!(rec->flags & FTRACE_FL_REGS) !=
 		    !(rec->flags & FTRACE_FL_REGS_EN))
 			flag |= FTRACE_FL_REGS;
 
-		if (!(rec->flags & FTRACE_FL_TRAMP) != 
+		if (!(rec->flags & FTRACE_FL_TRAMP) !=
 		    !(rec->flags & FTRACE_FL_TRAMP_EN))
 			flag |= FTRACE_FL_TRAMP;
+
+		/*
+		 * Direct calls are special, as count matters.
+		 * We must test the record for direct, if the
+		 * DIRECT and DIRECT_EN do not match, but only
+		 * if the count is 1. That's because, if the
+		 * count is something other than one, we do not
+		 * want the direct enabled (it will be done via the
+		 * direct helper). But if DIRECT_EN is set, and
+		 * the count is not one, we need to clear it.
+		 */
+		if (ftrace_rec_count(rec) == 1) {
+			if (!(rec->flags & FTRACE_FL_DIRECT) !=
+			    !(rec->flags & FTRACE_FL_DIRECT_EN))
+				flag |= FTRACE_FL_DIRECT;
+		} else if (rec->flags & FTRACE_FL_DIRECT_EN) {
+			flag |= FTRACE_FL_DIRECT;
+		}
 	}
 
 	/* If the state of this record hasn't changed, then do nothing */
@@ -2118,6 +2152,25 @@
 				else
 					rec->flags &= ~FTRACE_FL_TRAMP_EN;
 			}
+			if (flag & FTRACE_FL_DIRECT) {
+				/*
+				 * If there's only one user (direct_ops helper)
+				 * then we can call the direct function
+				 * directly (no ftrace trampoline).
+				 */
+				if (ftrace_rec_count(rec) == 1) {
+					if (rec->flags & FTRACE_FL_DIRECT)
+						rec->flags |= FTRACE_FL_DIRECT_EN;
+					else
+						rec->flags &= ~FTRACE_FL_DIRECT_EN;
+				} else {
+					/*
+					 * Can only call directly if there's
+					 * only one callback to the function.
+					 */
+					rec->flags &= ~FTRACE_FL_DIRECT_EN;
+				}
+			}
 		}
 
 		/*
@@ -2147,7 +2200,7 @@
 			 * and REGS states. The _EN flags must be disabled though.
 			 */
 			rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
-					FTRACE_FL_REGS_EN);
+					FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN);
 	}
 
 	ftrace_bug_type = FTRACE_BUG_NOP;
@@ -2230,7 +2283,7 @@
 
 		if (hash_contains_ip(ip, op->func_hash))
 			return op;
-	} 
+	}
 
 	return NULL;
 }
@@ -2320,19 +2373,77 @@
 	return NULL;
 }
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+/* Protected by rcu_tasks for reading, and direct_mutex for writing */
+static struct ftrace_hash *direct_functions = EMPTY_HASH;
+static DEFINE_MUTEX(direct_mutex);
+int ftrace_direct_func_count;
+
+/*
+ * Search the direct_functions hash to see if the given instruction pointer
+ * has a direct caller attached to it.
+ */
+unsigned long ftrace_find_rec_direct(unsigned long ip)
+{
+	struct ftrace_func_entry *entry;
+
+	entry = __ftrace_lookup_ip(direct_functions, ip);
+	if (!entry)
+		return 0;
+
+	return entry->direct;
+}
+
+static void call_direct_funcs(unsigned long ip, unsigned long pip,
+			      struct ftrace_ops *ops, struct pt_regs *regs)
+{
+	unsigned long addr;
+
+	addr = ftrace_find_rec_direct(ip);
+	if (!addr)
+		return;
+
+	arch_ftrace_set_direct_caller(regs, addr);
+}
+
+struct ftrace_ops direct_ops = {
+	.func		= call_direct_funcs,
+	.flags		= FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_RECURSION_SAFE
+			  | FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS
+			  | FTRACE_OPS_FL_PERMANENT,
+	/*
+	 * By declaring the main trampoline as this trampoline
+	 * it will never have one allocated for it. Allocated
+	 * trampolines should not call direct functions.
+	 * The direct_ops should only be called by the builtin
+	 * ftrace_regs_caller trampoline.
+	 */
+	.trampoline	= FTRACE_REGS_ADDR,
+};
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
+
 /**
  * ftrace_get_addr_new - Get the call address to set to
  * @rec:  The ftrace record descriptor
  *
  * If the record has the FTRACE_FL_REGS set, that means that it
  * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
- * is not not set, then it wants to convert to the normal callback.
+ * is not set, then it wants to convert to the normal callback.
  *
  * Returns the address of the trampoline to set to
  */
 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
 {
 	struct ftrace_ops *ops;
+	unsigned long addr;
+
+	if ((rec->flags & FTRACE_FL_DIRECT) &&
+	    (ftrace_rec_count(rec) == 1)) {
+		addr = ftrace_find_rec_direct(rec->ip);
+		if (addr)
+			return addr;
+		WARN_ON_ONCE(1);
+	}
 
 	/* Trampolines take precedence over regs */
 	if (rec->flags & FTRACE_FL_TRAMP) {
@@ -2365,6 +2476,15 @@
 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
 {
 	struct ftrace_ops *ops;
+	unsigned long addr;
+
+	/* Direct calls take precedence over trampolines */
+	if (rec->flags & FTRACE_FL_DIRECT_EN) {
+		addr = ftrace_find_rec_direct(rec->ip);
+		if (addr)
+			return addr;
+		WARN_ON_ONCE(1);
+	}
 
 	/* Trampolines take precedence over regs */
 	if (rec->flags & FTRACE_FL_TRAMP_EN) {
@@ -2520,14 +2640,14 @@
 }
 
 static int
-ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
+ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
 {
 	int ret;
 
 	if (unlikely(ftrace_disabled))
 		return 0;
 
-	ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
+	ret = ftrace_init_nop(mod, rec);
 	if (ret) {
 		ftrace_bug_type = FTRACE_BUG_INIT;
 		ftrace_bug(ret, rec);
@@ -2675,6 +2795,51 @@
 {
 }
 
+/* List of trace_ops that have allocated trampolines */
+static LIST_HEAD(ftrace_ops_trampoline_list);
+
+static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops)
+{
+	lockdep_assert_held(&ftrace_lock);
+	list_add_rcu(&ops->list, &ftrace_ops_trampoline_list);
+}
+
+static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
+{
+	lockdep_assert_held(&ftrace_lock);
+	list_del_rcu(&ops->list);
+	synchronize_rcu();
+}
+
+/*
+ * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols
+ * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is
+ * not a module.
+ */
+#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace"
+#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline"
+
+static void ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+	if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) &&
+	    ops->trampoline) {
+		/*
+		 * Record the text poke event before the ksymbol unregister
+		 * event.
+		 */
+		perf_event_text_poke((void *)ops->trampoline,
+				     (void *)ops->trampoline,
+				     ops->trampoline_size, NULL, 0);
+		perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+				   ops->trampoline, ops->trampoline_size,
+				   true, FTRACE_TRAMPOLINE_SYM);
+		/* Remove from kallsyms after the perf events */
+		ftrace_remove_trampoline_from_kallsyms(ops);
+	}
+
+	arch_ftrace_trampoline_free(ops);
+}
+
 static void ftrace_startup_enable(int command)
 {
 	if (saved_ftrace_func != ftrace_trace_function) {
@@ -2724,6 +2889,8 @@
 		__unregister_ftrace_function(ops);
 		ftrace_start_up--;
 		ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+		if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
+			ftrace_trampoline_free(ops);
 		return ret;
 	}
 
@@ -2832,10 +2999,10 @@
 		 * infrastructure to do the synchronization, thus we must do it
 		 * ourselves.
 		 */
-		schedule_on_each_cpu(ftrace_sync);
+		synchronize_rcu_tasks_rude();
 
 		/*
-		 * When the kernel is preeptive, tasks can be preempted
+		 * When the kernel is preemptive, tasks can be preempted
 		 * while on a ftrace trampoline. Just scheduling a task on
 		 * a CPU is not good enough to flush them. Calling
 		 * synchornize_rcu_tasks() will wait for those tasks to
@@ -2845,7 +3012,7 @@
 			synchronize_rcu_tasks();
 
  free_ops:
-		arch_ftrace_trampoline_free(ops);
+		ftrace_trampoline_free(ops);
 	}
 
 	return 0;
@@ -2887,6 +3054,8 @@
 
 static u64		ftrace_update_time;
 unsigned long		ftrace_update_tot_cnt;
+unsigned long		ftrace_number_of_pages;
+unsigned long		ftrace_number_of_groups;
 
 static inline int ops_traces_mod(struct ftrace_ops *ops)
 {
@@ -2969,7 +3138,7 @@
 			 * to the NOP instructions.
 			 */
 			if (!__is_defined(CC_USING_NOP_MCOUNT) &&
-			    !ftrace_code_disable(mod, p))
+			    !ftrace_nop_initialize(mod, p))
 				break;
 
 			update_cnt++;
@@ -2986,18 +3155,20 @@
 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
 {
 	int order;
+	int pages;
 	int cnt;
 
 	if (WARN_ON(!count))
 		return -EINVAL;
 
-	order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
+	pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE);
+	order = get_count_order(pages);
 
 	/*
 	 * We want to fill as much as possible. No more than a page
 	 * may be empty.
 	 */
-	while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
+	if (!is_power_of_2(pages))
 		order--;
 
  again:
@@ -3011,6 +3182,9 @@
 		goto again;
 	}
 
+	ftrace_number_of_pages += 1 << order;
+	ftrace_number_of_groups++;
+
 	cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
 	pg->size = cnt;
 
@@ -3062,10 +3236,13 @@
 	pg = start_pg;
 	while (pg) {
 		order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-		free_pages((unsigned long)pg->records, order);
+		if (order >= 0)
+			free_pages((unsigned long)pg->records, order);
 		start_pg = pg->next;
 		kfree(pg);
 		pg = start_pg;
+		ftrace_number_of_pages -= 1 << order;
+		ftrace_number_of_groups--;
 	}
 	pr_info("ftrace: FAILED to allocate memory for functions\n");
 	return NULL;
@@ -3476,10 +3653,11 @@
 	if (iter->flags & FTRACE_ITER_ENABLED) {
 		struct ftrace_ops *ops;
 
-		seq_printf(m, " (%ld)%s%s",
+		seq_printf(m, " (%ld)%s%s%s",
 			   ftrace_rec_count(rec),
 			   rec->flags & FTRACE_FL_REGS ? " R" : "  ",
-			   rec->flags & FTRACE_FL_IPMODIFY ? " I" : "  ");
+			   rec->flags & FTRACE_FL_IPMODIFY ? " I" : "  ",
+			   rec->flags & FTRACE_FL_DIRECT ? " D" : "  ");
 		if (rec->flags & FTRACE_FL_TRAMP_EN) {
 			ops = ftrace_find_tramp_ops_any(rec);
 			if (ops) {
@@ -3495,7 +3673,14 @@
 		} else {
 			add_trampoline_func(m, NULL, rec);
 		}
-	}	
+		if (rec->flags & FTRACE_FL_DIRECT) {
+			unsigned long direct;
+
+			direct = ftrace_find_rec_direct(rec->ip);
+			if (direct)
+				seq_printf(m, "\n\tdirect-->%pS", (void *)direct);
+		}
+	}
 
 	seq_putc(m, '\n');
 
@@ -4212,7 +4397,7 @@
  * @ip: The instruction pointer address to map @data to
  * @data: The data to map to @ip
  *
- * Returns 0 on succes otherwise an error.
+ * Returns 0 on success otherwise an error.
  */
 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
 			      unsigned long ip, void *data)
@@ -4380,7 +4565,7 @@
 
 	/*
 	 * Note, there's a small window here that the func_hash->filter_hash
-	 * may be NULL or empty. Need to be carefule when reading the loop.
+	 * may be NULL or empty. Need to be careful when reading the loop.
 	 */
 	mutex_lock(&probe->ops.func_hash->regex_lock);
 
@@ -4826,6 +5011,400 @@
 	return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable);
 }
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+
+struct ftrace_direct_func {
+	struct list_head	next;
+	unsigned long		addr;
+	int			count;
+};
+
+static LIST_HEAD(ftrace_direct_funcs);
+
+/**
+ * ftrace_find_direct_func - test an address if it is a registered direct caller
+ * @addr: The address of a registered direct caller
+ *
+ * This searches to see if a ftrace direct caller has been registered
+ * at a specific address, and if so, it returns a descriptor for it.
+ *
+ * This can be used by architecture code to see if an address is
+ * a direct caller (trampoline) attached to a fentry/mcount location.
+ * This is useful for the function_graph tracer, as it may need to
+ * do adjustments if it traced a location that also has a direct
+ * trampoline attached to it.
+ */
+struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
+{
+	struct ftrace_direct_func *entry;
+	bool found = false;
+
+	/* May be called by fgraph trampoline (protected by rcu tasks) */
+	list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) {
+		if (entry->addr == addr) {
+			found = true;
+			break;
+		}
+	}
+	if (found)
+		return entry;
+
+	return NULL;
+}
+
+static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr)
+{
+	struct ftrace_direct_func *direct;
+
+	direct = kmalloc(sizeof(*direct), GFP_KERNEL);
+	if (!direct)
+		return NULL;
+	direct->addr = addr;
+	direct->count = 0;
+	list_add_rcu(&direct->next, &ftrace_direct_funcs);
+	ftrace_direct_func_count++;
+	return direct;
+}
+
+/**
+ * register_ftrace_direct - Call a custom trampoline directly
+ * @ip: The address of the nop at the beginning of a function
+ * @addr: The address of the trampoline to call at @ip
+ *
+ * This is used to connect a direct call from the nop location (@ip)
+ * at the start of ftrace traced functions. The location that it calls
+ * (@addr) must be able to handle a direct call, and save the parameters
+ * of the function being traced, and restore them (or inject new ones
+ * if needed), before returning.
+ *
+ * Returns:
+ *  0 on success
+ *  -EBUSY - Another direct function is already attached (there can be only one)
+ *  -ENODEV - @ip does not point to a ftrace nop location (or not supported)
+ *  -ENOMEM - There was an allocation failure.
+ */
+int register_ftrace_direct(unsigned long ip, unsigned long addr)
+{
+	struct ftrace_direct_func *direct;
+	struct ftrace_func_entry *entry;
+	struct ftrace_hash *free_hash = NULL;
+	struct dyn_ftrace *rec;
+	int ret = -EBUSY;
+
+	mutex_lock(&direct_mutex);
+
+	/* See if there's a direct function at @ip already */
+	if (ftrace_find_rec_direct(ip))
+		goto out_unlock;
+
+	ret = -ENODEV;
+	rec = lookup_rec(ip, ip);
+	if (!rec)
+		goto out_unlock;
+
+	/*
+	 * Check if the rec says it has a direct call but we didn't
+	 * find one earlier?
+	 */
+	if (WARN_ON(rec->flags & FTRACE_FL_DIRECT))
+		goto out_unlock;
+
+	/* Make sure the ip points to the exact record */
+	if (ip != rec->ip) {
+		ip = rec->ip;
+		/* Need to check this ip for a direct. */
+		if (ftrace_find_rec_direct(ip))
+			goto out_unlock;
+	}
+
+	ret = -ENOMEM;
+	if (ftrace_hash_empty(direct_functions) ||
+	    direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
+		struct ftrace_hash *new_hash;
+		int size = ftrace_hash_empty(direct_functions) ? 0 :
+			direct_functions->count + 1;
+
+		if (size < 32)
+			size = 32;
+
+		new_hash = dup_hash(direct_functions, size);
+		if (!new_hash)
+			goto out_unlock;
+
+		free_hash = direct_functions;
+		direct_functions = new_hash;
+	}
+
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		goto out_unlock;
+
+	direct = ftrace_find_direct_func(addr);
+	if (!direct) {
+		direct = ftrace_alloc_direct_func(addr);
+		if (!direct) {
+			kfree(entry);
+			goto out_unlock;
+		}
+	}
+
+	entry->ip = ip;
+	entry->direct = addr;
+	__add_hash_entry(direct_functions, entry);
+
+	ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0);
+	if (ret)
+		remove_hash_entry(direct_functions, entry);
+
+	if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) {
+		ret = register_ftrace_function(&direct_ops);
+		if (ret)
+			ftrace_set_filter_ip(&direct_ops, ip, 1, 0);
+	}
+
+	if (ret) {
+		kfree(entry);
+		if (!direct->count) {
+			list_del_rcu(&direct->next);
+			synchronize_rcu_tasks();
+			kfree(direct);
+			if (free_hash)
+				free_ftrace_hash(free_hash);
+			free_hash = NULL;
+			ftrace_direct_func_count--;
+		}
+	} else {
+		direct->count++;
+	}
+ out_unlock:
+	mutex_unlock(&direct_mutex);
+
+	if (free_hash) {
+		synchronize_rcu_tasks();
+		free_ftrace_hash(free_hash);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_direct);
+
+static struct ftrace_func_entry *find_direct_entry(unsigned long *ip,
+						   struct dyn_ftrace **recp)
+{
+	struct ftrace_func_entry *entry;
+	struct dyn_ftrace *rec;
+
+	rec = lookup_rec(*ip, *ip);
+	if (!rec)
+		return NULL;
+
+	entry = __ftrace_lookup_ip(direct_functions, rec->ip);
+	if (!entry) {
+		WARN_ON(rec->flags & FTRACE_FL_DIRECT);
+		return NULL;
+	}
+
+	WARN_ON(!(rec->flags & FTRACE_FL_DIRECT));
+
+	/* Passed in ip just needs to be on the call site */
+	*ip = rec->ip;
+
+	if (recp)
+		*recp = rec;
+
+	return entry;
+}
+
+int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
+{
+	struct ftrace_direct_func *direct;
+	struct ftrace_func_entry *entry;
+	int ret = -ENODEV;
+
+	mutex_lock(&direct_mutex);
+
+	entry = find_direct_entry(&ip, NULL);
+	if (!entry)
+		goto out_unlock;
+
+	if (direct_functions->count == 1)
+		unregister_ftrace_function(&direct_ops);
+
+	ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0);
+
+	WARN_ON(ret);
+
+	remove_hash_entry(direct_functions, entry);
+
+	direct = ftrace_find_direct_func(addr);
+	if (!WARN_ON(!direct)) {
+		/* This is the good path (see the ! before WARN) */
+		direct->count--;
+		WARN_ON(direct->count < 0);
+		if (!direct->count) {
+			list_del_rcu(&direct->next);
+			synchronize_rcu_tasks();
+			kfree(direct);
+			kfree(entry);
+			ftrace_direct_func_count--;
+		}
+	}
+ out_unlock:
+	mutex_unlock(&direct_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
+
+static struct ftrace_ops stub_ops = {
+	.func		= ftrace_stub,
+};
+
+/**
+ * ftrace_modify_direct_caller - modify ftrace nop directly
+ * @entry: The ftrace hash entry of the direct helper for @rec
+ * @rec: The record representing the function site to patch
+ * @old_addr: The location that the site at @rec->ip currently calls
+ * @new_addr: The location that the site at @rec->ip should call
+ *
+ * An architecture may overwrite this function to optimize the
+ * changing of the direct callback on an ftrace nop location.
+ * This is called with the ftrace_lock mutex held, and no other
+ * ftrace callbacks are on the associated record (@rec). Thus,
+ * it is safe to modify the ftrace record, where it should be
+ * currently calling @old_addr directly, to call @new_addr.
+ *
+ * Safety checks should be made to make sure that the code at
+ * @rec->ip is currently calling @old_addr. And this must
+ * also update entry->direct to @new_addr.
+ */
+int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
+				       struct dyn_ftrace *rec,
+				       unsigned long old_addr,
+				       unsigned long new_addr)
+{
+	unsigned long ip = rec->ip;
+	int ret;
+
+	/*
+	 * The ftrace_lock was used to determine if the record
+	 * had more than one registered user to it. If it did,
+	 * we needed to prevent that from changing to do the quick
+	 * switch. But if it did not (only a direct caller was attached)
+	 * then this function is called. But this function can deal
+	 * with attached callers to the rec that we care about, and
+	 * since this function uses standard ftrace calls that take
+	 * the ftrace_lock mutex, we need to release it.
+	 */
+	mutex_unlock(&ftrace_lock);
+
+	/*
+	 * By setting a stub function at the same address, we force
+	 * the code to call the iterator and the direct_ops helper.
+	 * This means that @ip does not call the direct call, and
+	 * we can simply modify it.
+	 */
+	ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0);
+	if (ret)
+		goto out_lock;
+
+	ret = register_ftrace_function(&stub_ops);
+	if (ret) {
+		ftrace_set_filter_ip(&stub_ops, ip, 1, 0);
+		goto out_lock;
+	}
+
+	entry->direct = new_addr;
+
+	/*
+	 * By removing the stub, we put back the direct call, calling
+	 * the @new_addr.
+	 */
+	unregister_ftrace_function(&stub_ops);
+	ftrace_set_filter_ip(&stub_ops, ip, 1, 0);
+
+ out_lock:
+	mutex_lock(&ftrace_lock);
+
+	return ret;
+}
+
+/**
+ * modify_ftrace_direct - Modify an existing direct call to call something else
+ * @ip: The instruction pointer to modify
+ * @old_addr: The address that the current @ip calls directly
+ * @new_addr: The address that the @ip should call
+ *
+ * This modifies a ftrace direct caller at an instruction pointer without
+ * having to disable it first. The direct call will switch over to the
+ * @new_addr without missing anything.
+ *
+ * Returns: zero on success. Non zero on error, which includes:
+ *  -ENODEV : the @ip given has no direct caller attached
+ *  -EINVAL : the @old_addr does not match the current direct caller
+ */
+int modify_ftrace_direct(unsigned long ip,
+			 unsigned long old_addr, unsigned long new_addr)
+{
+	struct ftrace_direct_func *direct, *new_direct = NULL;
+	struct ftrace_func_entry *entry;
+	struct dyn_ftrace *rec;
+	int ret = -ENODEV;
+
+	mutex_lock(&direct_mutex);
+
+	mutex_lock(&ftrace_lock);
+	entry = find_direct_entry(&ip, &rec);
+	if (!entry)
+		goto out_unlock;
+
+	ret = -EINVAL;
+	if (entry->direct != old_addr)
+		goto out_unlock;
+
+	direct = ftrace_find_direct_func(old_addr);
+	if (WARN_ON(!direct))
+		goto out_unlock;
+	if (direct->count > 1) {
+		ret = -ENOMEM;
+		new_direct = ftrace_alloc_direct_func(new_addr);
+		if (!new_direct)
+			goto out_unlock;
+		direct->count--;
+		new_direct->count++;
+	} else {
+		direct->addr = new_addr;
+	}
+
+	/*
+	 * If there's no other ftrace callback on the rec->ip location,
+	 * then it can be changed directly by the architecture.
+	 * If there is another caller, then we just need to change the
+	 * direct caller helper to point to @new_addr.
+	 */
+	if (ftrace_rec_count(rec) == 1) {
+		ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr);
+	} else {
+		entry->direct = new_addr;
+		ret = 0;
+	}
+
+	if (unlikely(ret && new_direct)) {
+		direct->count++;
+		list_del_rcu(&new_direct->next);
+		synchronize_rcu_tasks();
+		kfree(new_direct);
+		ftrace_direct_func_count--;
+	}
+
+ out_unlock:
+	mutex_unlock(&ftrace_lock);
+	mutex_unlock(&direct_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct);
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
+
 /**
  * ftrace_set_filter_ip - set a function to filter on in ftrace by address
  * @ops - the ops to set the filter with
@@ -4996,7 +5575,7 @@
 	struct ftrace_hash *hash;
 
 	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
-	if (WARN_ON(!hash))
+	if (MEM_FAIL(!hash, "Failed to allocate hash\n"))
 		return;
 
 	while (buf) {
@@ -5415,7 +5994,7 @@
 		 * infrastructure to do the synchronization, thus we must do it
 		 * ourselves.
 		 */
-		schedule_on_each_cpu(ftrace_sync);
+		synchronize_rcu_tasks_rude();
 
 		free_ftrace_hash(old_hash);
 	}
@@ -5716,6 +6295,27 @@
 	unsigned int		num_funcs;
 };
 
+static int ftrace_get_trampoline_kallsym(unsigned int symnum,
+					 unsigned long *value, char *type,
+					 char *name, char *module_name,
+					 int *exported)
+{
+	struct ftrace_ops *op;
+
+	list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) {
+		if (!op->trampoline || symnum--)
+			continue;
+		*value = op->trampoline;
+		*type = 't';
+		strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
+		strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
+		*exported = 0;
+		return 0;
+	}
+
+	return -ERANGE;
+}
+
 #ifdef CONFIG_MODULES
 
 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
@@ -5729,9 +6329,17 @@
 
 	for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
 		if (ops_references_rec(ops, rec)) {
+			if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
+				continue;
+			if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
+				continue;
 			cnt++;
 			if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
 				rec->flags |= FTRACE_FL_REGS;
+			if (cnt == 1 && ops->trampoline)
+				rec->flags |= FTRACE_FL_TRAMP;
+			else
+				rec->flags &= ~FTRACE_FL_TRAMP;
 		}
 	}
 
@@ -5854,9 +6462,12 @@
 		clear_mod_from_hashes(pg);
 
 		order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-		free_pages((unsigned long)pg->records, order);
+		if (order >= 0)
+			free_pages((unsigned long)pg->records, order);
 		tmp_page = pg->next;
 		kfree(pg);
+		ftrace_number_of_pages -= 1 << order;
+		ftrace_number_of_groups--;
 	}
 }
 
@@ -6053,6 +6664,7 @@
 {
 	struct ftrace_mod_map *mod_map;
 	struct ftrace_mod_func *mod_func;
+	int ret;
 
 	preempt_disable();
 	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
@@ -6079,8 +6691,10 @@
 		WARN_ON(1);
 		break;
 	}
+	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
+					    module_name, exported);
 	preempt_enable();
-	return -ERANGE;
+	return ret;
 }
 
 #else
@@ -6092,6 +6706,18 @@
 {
 	return NULL;
 }
+int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
+			   char *type, char *name, char *module_name,
+			   int *exported)
+{
+	int ret;
+
+	preempt_disable();
+	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
+					    module_name, exported);
+	preempt_enable();
+	return ret;
+}
 #endif /* CONFIG_MODULES */
 
 struct ftrace_init_func {
@@ -6139,7 +6765,7 @@
 
 	func = kmalloc(sizeof(*func), GFP_KERNEL);
 	if (!func) {
-		WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
+		MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n");
 		return;
 	}
 
@@ -6197,7 +6823,10 @@
 		if (!pg->index) {
 			*last_pg = pg->next;
 			order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-			free_pages((unsigned long)pg->records, order);
+			if (order >= 0)
+				free_pages((unsigned long)pg->records, order);
+			ftrace_number_of_pages -= 1 << order;
+			ftrace_number_of_groups--;
 			kfree(pg);
 			pg = container_of(last_pg, struct ftrace_page, next);
 			if (!(*last_pg))
@@ -6253,6 +6882,9 @@
 				  __start_mcount_loc,
 				  __stop_mcount_loc);
 
+	pr_info("ftrace: allocated %ld pages with %ld groups\n",
+		ftrace_number_of_pages, ftrace_number_of_groups);
+
 	set_ftrace_early_filters();
 
 	return;
@@ -6267,7 +6899,24 @@
 
 static void ftrace_update_trampoline(struct ftrace_ops *ops)
 {
+	unsigned long trampoline = ops->trampoline;
+
 	arch_ftrace_update_trampoline(ops);
+	if (ops->trampoline && ops->trampoline != trampoline &&
+	    (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) {
+		/* Add to kallsyms before the perf events */
+		ftrace_add_trampoline_to_kallsyms(ops);
+		perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+				   ops->trampoline, ops->trampoline_size, false,
+				   FTRACE_TRAMPOLINE_SYM);
+		/*
+		 * Record the perf text poke event after the ksymbol register
+		 * event.
+		 */
+		perf_event_text_poke((void *)ops->trampoline, NULL, 0,
+				     (void *)ops->trampoline,
+				     ops->trampoline_size);
+	}
 }
 
 void ftrace_init_trace_array(struct trace_array *tr)
@@ -6336,7 +6985,7 @@
 	struct ftrace_ops *op;
 	int bit;
 
-	bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
+	bit = trace_test_and_set_recursion(TRACE_LIST_START);
 	if (bit < 0)
 		return;
 
@@ -6411,7 +7060,7 @@
 {
 	int bit;
 
-	bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
+	bit = trace_test_and_set_recursion(TRACE_LIST_START);
 	if (bit < 0)
 		return;
 
@@ -6455,11 +7104,17 @@
 {
 	struct trace_array *tr = data;
 	struct trace_pid_list *pid_list;
+	struct trace_pid_list *no_pid_list;
 
 	pid_list = rcu_dereference_sched(tr->function_pids);
+	no_pid_list = rcu_dereference_sched(tr->function_no_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
-		       trace_ignore_this_task(pid_list, next));
+	if (trace_ignore_this_task(pid_list, no_pid_list, next))
+		this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+			       FTRACE_PID_IGNORE);
+	else
+		this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+			       next->pid);
 }
 
 static void
@@ -6472,6 +7127,9 @@
 
 	pid_list = rcu_dereference_sched(tr->function_pids);
 	trace_filter_add_remove_task(pid_list, self, task);
+
+	pid_list = rcu_dereference_sched(tr->function_no_pids);
+	trace_filter_add_remove_task(pid_list, self, task);
 }
 
 static void
@@ -6482,6 +7140,9 @@
 
 	pid_list = rcu_dereference_sched(tr->function_pids);
 	trace_filter_add_remove_task(pid_list, NULL, task);
+
+	pid_list = rcu_dereference_sched(tr->function_no_pids);
+	trace_filter_add_remove_task(pid_list, NULL, task);
 }
 
 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
@@ -6499,42 +7160,57 @@
 	}
 }
 
-static void clear_ftrace_pids(struct trace_array *tr)
+static void clear_ftrace_pids(struct trace_array *tr, int type)
 {
 	struct trace_pid_list *pid_list;
+	struct trace_pid_list *no_pid_list;
 	int cpu;
 
 	pid_list = rcu_dereference_protected(tr->function_pids,
 					     lockdep_is_held(&ftrace_lock));
-	if (!pid_list)
+	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
+						lockdep_is_held(&ftrace_lock));
+
+	/* Make sure there's something to do */
+	if (!pid_type_enabled(type, pid_list, no_pid_list))
 		return;
 
-	unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
+	/* See if the pids still need to be checked after this */
+	if (!still_need_pid_events(type, pid_list, no_pid_list)) {
+		unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
+		for_each_possible_cpu(cpu)
+			per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE;
+	}
 
-	for_each_possible_cpu(cpu)
-		per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
+	if (type & TRACE_PIDS)
+		rcu_assign_pointer(tr->function_pids, NULL);
 
-	rcu_assign_pointer(tr->function_pids, NULL);
+	if (type & TRACE_NO_PIDS)
+		rcu_assign_pointer(tr->function_no_pids, NULL);
 
 	/* Wait till all users are no longer using pid filtering */
 	synchronize_rcu();
 
-	trace_free_pid_list(pid_list);
+	if ((type & TRACE_PIDS) && pid_list)
+		trace_free_pid_list(pid_list);
+
+	if ((type & TRACE_NO_PIDS) && no_pid_list)
+		trace_free_pid_list(no_pid_list);
 }
 
 void ftrace_clear_pids(struct trace_array *tr)
 {
 	mutex_lock(&ftrace_lock);
 
-	clear_ftrace_pids(tr);
+	clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
 
 	mutex_unlock(&ftrace_lock);
 }
 
-static void ftrace_pid_reset(struct trace_array *tr)
+static void ftrace_pid_reset(struct trace_array *tr, int type)
 {
 	mutex_lock(&ftrace_lock);
-	clear_ftrace_pids(tr);
+	clear_ftrace_pids(tr, type);
 
 	ftrace_update_pid_func();
 	ftrace_startup_all(0);
@@ -6598,9 +7274,45 @@
 	.show = fpid_show,
 };
 
-static int
-ftrace_pid_open(struct inode *inode, struct file *file)
+static void *fnpid_start(struct seq_file *m, loff_t *pos)
+	__acquires(RCU)
 {
+	struct trace_pid_list *pid_list;
+	struct trace_array *tr = m->private;
+
+	mutex_lock(&ftrace_lock);
+	rcu_read_lock_sched();
+
+	pid_list = rcu_dereference_sched(tr->function_no_pids);
+
+	if (!pid_list)
+		return !(*pos) ? FTRACE_NO_PIDS : NULL;
+
+	return trace_pid_start(pid_list, pos);
+}
+
+static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct trace_array *tr = m->private;
+	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids);
+
+	if (v == FTRACE_NO_PIDS) {
+		(*pos)++;
+		return NULL;
+	}
+	return trace_pid_next(pid_list, v, pos);
+}
+
+static const struct seq_operations ftrace_no_pid_sops = {
+	.start = fnpid_start,
+	.next = fnpid_next,
+	.stop = fpid_stop,
+	.show = fpid_show,
+};
+
+static int pid_open(struct inode *inode, struct file *file, int type)
+{
+	const struct seq_operations *seq_ops;
 	struct trace_array *tr = inode->i_private;
 	struct seq_file *m;
 	int ret = 0;
@@ -6611,9 +7323,22 @@
 
 	if ((file->f_mode & FMODE_WRITE) &&
 	    (file->f_flags & O_TRUNC))
-		ftrace_pid_reset(tr);
+		ftrace_pid_reset(tr, type);
 
-	ret = seq_open(file, &ftrace_pid_sops);
+	switch (type) {
+	case TRACE_PIDS:
+		seq_ops = &ftrace_pid_sops;
+		break;
+	case TRACE_NO_PIDS:
+		seq_ops = &ftrace_no_pid_sops;
+		break;
+	default:
+		trace_array_put(tr);
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
+	ret = seq_open(file, seq_ops);
 	if (ret < 0) {
 		trace_array_put(tr);
 	} else {
@@ -6625,10 +7350,23 @@
 	return ret;
 }
 
+static int
+ftrace_pid_open(struct inode *inode, struct file *file)
+{
+	return pid_open(inode, file, TRACE_PIDS);
+}
+
+static int
+ftrace_no_pid_open(struct inode *inode, struct file *file)
+{
+	return pid_open(inode, file, TRACE_NO_PIDS);
+}
+
 static void ignore_task_cpu(void *data)
 {
 	struct trace_array *tr = data;
 	struct trace_pid_list *pid_list;
+	struct trace_pid_list *no_pid_list;
 
 	/*
 	 * This function is called by on_each_cpu() while the
@@ -6636,18 +7374,25 @@
 	 */
 	pid_list = rcu_dereference_protected(tr->function_pids,
 					     mutex_is_locked(&ftrace_lock));
+	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
+						mutex_is_locked(&ftrace_lock));
 
-	this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
-		       trace_ignore_this_task(pid_list, current));
+	if (trace_ignore_this_task(pid_list, no_pid_list, current))
+		this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+			       FTRACE_PID_IGNORE);
+	else
+		this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+			       current->pid);
 }
 
 static ssize_t
-ftrace_pid_write(struct file *filp, const char __user *ubuf,
-		   size_t cnt, loff_t *ppos)
+pid_write(struct file *filp, const char __user *ubuf,
+	  size_t cnt, loff_t *ppos, int type)
 {
 	struct seq_file *m = filp->private_data;
 	struct trace_array *tr = m->private;
-	struct trace_pid_list *filtered_pids = NULL;
+	struct trace_pid_list *filtered_pids;
+	struct trace_pid_list *other_pids;
 	struct trace_pid_list *pid_list;
 	ssize_t ret;
 
@@ -6656,19 +7401,43 @@
 
 	mutex_lock(&ftrace_lock);
 
-	filtered_pids = rcu_dereference_protected(tr->function_pids,
+	switch (type) {
+	case TRACE_PIDS:
+		filtered_pids = rcu_dereference_protected(tr->function_pids,
 					     lockdep_is_held(&ftrace_lock));
+		other_pids = rcu_dereference_protected(tr->function_no_pids,
+					     lockdep_is_held(&ftrace_lock));
+		break;
+	case TRACE_NO_PIDS:
+		filtered_pids = rcu_dereference_protected(tr->function_no_pids,
+					     lockdep_is_held(&ftrace_lock));
+		other_pids = rcu_dereference_protected(tr->function_pids,
+					     lockdep_is_held(&ftrace_lock));
+		break;
+	default:
+		ret = -EINVAL;
+		WARN_ON_ONCE(1);
+		goto out;
+	}
 
 	ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
 	if (ret < 0)
 		goto out;
 
-	rcu_assign_pointer(tr->function_pids, pid_list);
+	switch (type) {
+	case TRACE_PIDS:
+		rcu_assign_pointer(tr->function_pids, pid_list);
+		break;
+	case TRACE_NO_PIDS:
+		rcu_assign_pointer(tr->function_no_pids, pid_list);
+		break;
+	}
+
 
 	if (filtered_pids) {
 		synchronize_rcu();
 		trace_free_pid_list(filtered_pids);
-	} else if (pid_list) {
+	} else if (pid_list && !other_pids) {
 		/* Register a probe to set whether to ignore the tracing of a task */
 		register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
 	}
@@ -6691,6 +7460,20 @@
 	return ret;
 }
 
+static ssize_t
+ftrace_pid_write(struct file *filp, const char __user *ubuf,
+		 size_t cnt, loff_t *ppos)
+{
+	return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
+}
+
+static ssize_t
+ftrace_no_pid_write(struct file *filp, const char __user *ubuf,
+		    size_t cnt, loff_t *ppos)
+{
+	return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
+}
+
 static int
 ftrace_pid_release(struct inode *inode, struct file *file)
 {
@@ -6709,10 +7492,20 @@
 	.release	= ftrace_pid_release,
 };
 
+static const struct file_operations ftrace_no_pid_fops = {
+	.open		= ftrace_no_pid_open,
+	.write		= ftrace_no_pid_write,
+	.read		= seq_read,
+	.llseek		= tracing_lseek,
+	.release	= ftrace_pid_release,
+};
+
 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
 {
 	trace_create_file("set_ftrace_pid", 0644, d_tracer,
 			    tr, &ftrace_pid_fops);
+	trace_create_file("set_ftrace_notrace_pid", 0644, d_tracer,
+			    tr, &ftrace_no_pid_fops);
 }
 
 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
@@ -6792,10 +7585,21 @@
 }
 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
 
+static bool is_permanent_ops_registered(void)
+{
+	struct ftrace_ops *op;
+
+	do_for_each_ftrace_op(op, ftrace_ops_list) {
+		if (op->flags & FTRACE_OPS_FL_PERMANENT)
+			return true;
+	} while_for_each_ftrace_op(op);
+
+	return false;
+}
+
 int
 ftrace_enable_sysctl(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp,
-		     loff_t *ppos)
+		     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = -ENODEV;
 
@@ -6809,8 +7613,6 @@
 	if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
 		goto out;
 
-	last_ftrace_enabled = !!ftrace_enabled;
-
 	if (ftrace_enabled) {
 
 		/* we are starting ftrace again */
@@ -6821,12 +7623,19 @@
 		ftrace_startup_sysctl();
 
 	} else {
+		if (is_permanent_ops_registered()) {
+			ftrace_enabled = true;
+			ret = -EBUSY;
+			goto out;
+		}
+
 		/* stopping ftrace calls (just send to ftrace_stub) */
 		ftrace_trace_function = ftrace_stub;
 
 		ftrace_shutdown_sysctl();
 	}
 
+	last_ftrace_enabled = !!ftrace_enabled;
  out:
 	mutex_unlock(&ftrace_lock);
 	return ret;
diff --git a/kernel/trace/ftrace_internal.h b/kernel/trace/ftrace_internal.h
index 0456e0a..382775e 100644
--- a/kernel/trace/ftrace_internal.h
+++ b/kernel/trace/ftrace_internal.h
@@ -4,28 +4,6 @@
 
 #ifdef CONFIG_FUNCTION_TRACER
 
-/*
- * Traverse the ftrace_global_list, invoking all entries.  The reason that we
- * can use rcu_dereference_raw_check() is that elements removed from this list
- * are simply leaked, so there is no need to interact with a grace-period
- * mechanism.  The rcu_dereference_raw_check() calls are needed to handle
- * concurrent insertions into the ftrace_global_list.
- *
- * Silly Alpha and silly pointer-speculation compiler optimizations!
- */
-#define do_for_each_ftrace_op(op, list)			\
-	op = rcu_dereference_raw_check(list);			\
-	do
-
-/*
- * Optimized for just a single item in the list (as that is the normal case).
- */
-#define while_for_each_ftrace_op(op)				\
-	while (likely(op = rcu_dereference_raw_check((op)->next)) &&	\
-	       unlikely((op) != &ftrace_list_end))
-
-extern struct ftrace_ops __rcu *ftrace_ops_list;
-extern struct ftrace_ops ftrace_list_end;
 extern struct mutex ftrace_lock;
 extern struct ftrace_ops global_ops;
 
diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c
new file mode 100644
index 0000000..18b0f1c
--- /dev/null
+++ b/kernel/trace/kprobe_event_gen_test.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test module for in-kernel kprobe event creation and generation.
+ *
+ * Copyright (C) 2019 Tom Zanussi <zanussi@kernel.org>
+ */
+
+#include <linux/module.h>
+#include <linux/trace_events.h>
+
+/*
+ * This module is a simple test of basic functionality for in-kernel
+ * kprobe/kretprobe event creation.  The first test uses
+ * kprobe_event_gen_cmd_start(), kprobe_event_add_fields() and
+ * kprobe_event_gen_cmd_end() to create a kprobe event, which is then
+ * enabled in order to generate trace output.  The second creates a
+ * kretprobe event using kretprobe_event_gen_cmd_start() and
+ * kretprobe_event_gen_cmd_end(), and is also then enabled.
+ *
+ * To test, select CONFIG_KPROBE_EVENT_GEN_TEST and build the module.
+ * Then:
+ *
+ * # insmod kernel/trace/kprobe_event_gen_test.ko
+ * # cat /sys/kernel/debug/tracing/trace
+ *
+ * You should see many instances of the "gen_kprobe_test" and
+ * "gen_kretprobe_test" events in the trace buffer.
+ *
+ * To remove the events, remove the module:
+ *
+ * # rmmod kprobe_event_gen_test
+ *
+ */
+
+static struct trace_event_file *gen_kprobe_test;
+static struct trace_event_file *gen_kretprobe_test;
+
+/*
+ * Test to make sure we can create a kprobe event, then add more
+ * fields.
+ */
+static int __init test_gen_kprobe_cmd(void)
+{
+	struct dynevent_cmd cmd;
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	kprobe_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Define the gen_kprobe_test event with the first 2 kprobe
+	 * fields.
+	 */
+	ret = kprobe_event_gen_cmd_start(&cmd, "gen_kprobe_test",
+					 "do_sys_open",
+					 "dfd=%ax", "filename=%dx");
+	if (ret)
+		goto free;
+
+	/* Use kprobe_event_add_fields to add the rest of the fields */
+
+	ret = kprobe_event_add_fields(&cmd, "flags=%cx", "mode=+4($stack)");
+	if (ret)
+		goto free;
+
+	/*
+	 * This actually creates the event.
+	 */
+	ret = kprobe_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the gen_kprobe_test event file.  We need to prevent
+	 * the instance and event from disappearing from underneath
+	 * us, which trace_get_event_file() does (though in this case
+	 * we're using the top-level instance which never goes away).
+	 */
+	gen_kprobe_test = trace_get_event_file(NULL, "kprobes",
+					       "gen_kprobe_test");
+	if (IS_ERR(gen_kprobe_test)) {
+		ret = PTR_ERR(gen_kprobe_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(gen_kprobe_test->tr,
+					"kprobes", "gen_kprobe_test", true);
+	if (ret) {
+		trace_put_event_file(gen_kprobe_test);
+		goto delete;
+	}
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	ret = kprobe_event_delete("gen_kprobe_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+/*
+ * Test to make sure we can create a kretprobe event.
+ */
+static int __init test_gen_kretprobe_cmd(void)
+{
+	struct dynevent_cmd cmd;
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	kprobe_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Define the kretprobe event.
+	 */
+	ret = kretprobe_event_gen_cmd_start(&cmd, "gen_kretprobe_test",
+					    "do_sys_open",
+					    "$retval");
+	if (ret)
+		goto free;
+
+	/*
+	 * This actually creates the event.
+	 */
+	ret = kretprobe_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the gen_kretprobe_test event file.  We need to
+	 * prevent the instance and event from disappearing from
+	 * underneath us, which trace_get_event_file() does (though in
+	 * this case we're using the top-level instance which never
+	 * goes away).
+	 */
+	gen_kretprobe_test = trace_get_event_file(NULL, "kprobes",
+						  "gen_kretprobe_test");
+	if (IS_ERR(gen_kretprobe_test)) {
+		ret = PTR_ERR(gen_kretprobe_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(gen_kretprobe_test->tr,
+					"kprobes", "gen_kretprobe_test", true);
+	if (ret) {
+		trace_put_event_file(gen_kretprobe_test);
+		goto delete;
+	}
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	ret = kprobe_event_delete("gen_kretprobe_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+static int __init kprobe_event_gen_test_init(void)
+{
+	int ret;
+
+	ret = test_gen_kprobe_cmd();
+	if (ret)
+		return ret;
+
+	ret = test_gen_kretprobe_cmd();
+	if (ret) {
+		WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
+						  "kprobes",
+						  "gen_kretprobe_test", false));
+		trace_put_event_file(gen_kretprobe_test);
+		WARN_ON(kprobe_event_delete("gen_kretprobe_test"));
+	}
+
+	return ret;
+}
+
+static void __exit kprobe_event_gen_test_exit(void)
+{
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
+					  "kprobes",
+					  "gen_kprobe_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(gen_kprobe_test);
+
+	/* Now unregister and free the event */
+	WARN_ON(kprobe_event_delete("gen_kprobe_test"));
+
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
+					  "kprobes",
+					  "gen_kretprobe_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(gen_kretprobe_test);
+
+	/* Now unregister and free the event */
+	WARN_ON(kprobe_event_delete("gen_kretprobe_test"));
+}
+
+module_init(kprobe_event_gen_test_init)
+module_exit(kprobe_event_gen_test_exit)
+
+MODULE_AUTHOR("Tom Zanussi");
+MODULE_DESCRIPTION("kprobe event generation test");
+MODULE_LICENSE("GPL v2");
diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c
index d8765c9..312d1a0 100644
--- a/kernel/trace/preemptirq_delay_test.c
+++ b/kernel/trace/preemptirq_delay_test.c
@@ -10,18 +10,28 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
+#include <linux/kobject.h>
 #include <linux/kthread.h>
 #include <linux/module.h>
 #include <linux/printk.h>
 #include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/completion.h>
 
 static ulong delay = 100;
-static char test_mode[10] = "irq";
+static char test_mode[12] = "irq";
+static uint burst_size = 1;
 
-module_param_named(delay, delay, ulong, S_IRUGO);
-module_param_string(test_mode, test_mode, 10, S_IRUGO);
-MODULE_PARM_DESC(delay, "Period in microseconds (100 uS default)");
-MODULE_PARM_DESC(test_mode, "Mode of the test such as preempt or irq (default irq)");
+module_param_named(delay, delay, ulong, 0444);
+module_param_string(test_mode, test_mode, 12, 0444);
+module_param_named(burst_size, burst_size, uint, 0444);
+MODULE_PARM_DESC(delay, "Period in microseconds (100 us default)");
+MODULE_PARM_DESC(test_mode, "Mode of the test such as preempt, irq, or alternate (default irq)");
+MODULE_PARM_DESC(burst_size, "The size of a burst (default 1)");
+
+static struct completion done;
+
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
 
 static void busy_wait(ulong time)
 {
@@ -34,37 +44,159 @@
 	} while ((end - start) < (time * 1000));
 }
 
-static int preemptirq_delay_run(void *data)
+static __always_inline void irqoff_test(void)
 {
 	unsigned long flags;
+	local_irq_save(flags);
+	busy_wait(delay);
+	local_irq_restore(flags);
+}
 
-	if (!strcmp(test_mode, "irq")) {
-		local_irq_save(flags);
-		busy_wait(delay);
-		local_irq_restore(flags);
-	} else if (!strcmp(test_mode, "preempt")) {
-		preempt_disable();
-		busy_wait(delay);
-		preempt_enable();
+static __always_inline void preemptoff_test(void)
+{
+	preempt_disable();
+	busy_wait(delay);
+	preempt_enable();
+}
+
+static void execute_preemptirqtest(int idx)
+{
+	if (!strcmp(test_mode, "irq"))
+		irqoff_test();
+	else if (!strcmp(test_mode, "preempt"))
+		preemptoff_test();
+	else if (!strcmp(test_mode, "alternate")) {
+		if (idx % 2 == 0)
+			irqoff_test();
+		else
+			preemptoff_test();
 	}
+}
+
+#define DECLARE_TESTFN(POSTFIX)				\
+	static void preemptirqtest_##POSTFIX(int idx)	\
+	{						\
+		execute_preemptirqtest(idx);		\
+	}						\
+
+/*
+ * We create 10 different functions, so that we can get 10 different
+ * backtraces.
+ */
+DECLARE_TESTFN(0)
+DECLARE_TESTFN(1)
+DECLARE_TESTFN(2)
+DECLARE_TESTFN(3)
+DECLARE_TESTFN(4)
+DECLARE_TESTFN(5)
+DECLARE_TESTFN(6)
+DECLARE_TESTFN(7)
+DECLARE_TESTFN(8)
+DECLARE_TESTFN(9)
+
+static void (*testfuncs[])(int)  = {
+	preemptirqtest_0,
+	preemptirqtest_1,
+	preemptirqtest_2,
+	preemptirqtest_3,
+	preemptirqtest_4,
+	preemptirqtest_5,
+	preemptirqtest_6,
+	preemptirqtest_7,
+	preemptirqtest_8,
+	preemptirqtest_9,
+};
+
+#define NR_TEST_FUNCS ARRAY_SIZE(testfuncs)
+
+static int preemptirq_delay_run(void *data)
+{
+	int i;
+	int s = MIN(burst_size, NR_TEST_FUNCS);
+
+	for (i = 0; i < s; i++)
+		(testfuncs[i])(i);
+
+	complete(&done);
+
+	set_current_state(TASK_INTERRUPTIBLE);
+	while (!kthread_should_stop()) {
+		schedule();
+		set_current_state(TASK_INTERRUPTIBLE);
+	}
+
+	__set_current_state(TASK_RUNNING);
 
 	return 0;
 }
 
-static int __init preemptirq_delay_init(void)
+static int preemptirq_run_test(void)
 {
+	struct task_struct *task;
 	char task_name[50];
-	struct task_struct *test_task;
+
+	init_completion(&done);
 
 	snprintf(task_name, sizeof(task_name), "%s_test", test_mode);
+	task =  kthread_run(preemptirq_delay_run, NULL, task_name);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	if (task) {
+		wait_for_completion(&done);
+		kthread_stop(task);
+	}
+	return 0;
+}
 
-	test_task = kthread_run(preemptirq_delay_run, NULL, task_name);
-	return PTR_ERR_OR_ZERO(test_task);
+
+static ssize_t trigger_store(struct kobject *kobj, struct kobj_attribute *attr,
+			 const char *buf, size_t count)
+{
+	ssize_t ret;
+
+	ret = preemptirq_run_test();
+	if (ret)
+		return ret;
+	return count;
+}
+
+static struct kobj_attribute trigger_attribute =
+	__ATTR(trigger, 0200, NULL, trigger_store);
+
+static struct attribute *attrs[] = {
+	&trigger_attribute.attr,
+	NULL,
+};
+
+static struct attribute_group attr_group = {
+	.attrs = attrs,
+};
+
+static struct kobject *preemptirq_delay_kobj;
+
+static int __init preemptirq_delay_init(void)
+{
+	int retval;
+
+	retval = preemptirq_run_test();
+	if (retval != 0)
+		return retval;
+
+	preemptirq_delay_kobj = kobject_create_and_add("preemptirq_delay_test",
+						       kernel_kobj);
+	if (!preemptirq_delay_kobj)
+		return -ENOMEM;
+
+	retval = sysfs_create_group(preemptirq_delay_kobj, &attr_group);
+	if (retval)
+		kobject_put(preemptirq_delay_kobj);
+
+	return retval;
 }
 
 static void __exit preemptirq_delay_exit(void)
 {
-	return;
+	kobject_put(preemptirq_delay_kobj);
 }
 
 module_init(preemptirq_delay_init)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 5e1b9f6..6deac66 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -202,7 +202,7 @@
 	case RINGBUF_TYPE_DATA:
 		return rb_event_data_length(event);
 	default:
-		BUG();
+		WARN_ON_ONCE(1);
 	}
 	/* not hit */
 	return 0;
@@ -258,7 +258,7 @@
 {
 	if (extended_time(event))
 		event = skip_time_extend(event);
-	BUG_ON(event->type_len > RINGBUF_TYPE_DATA_TYPE_LEN_MAX);
+	WARN_ON_ONCE(event->type_len > RINGBUF_TYPE_DATA_TYPE_LEN_MAX);
 	/* If length is in len field, then array[0] has the data */
 	if (event->type_len)
 		return (void *)&event->array[0];
@@ -279,6 +279,9 @@
 #define for_each_buffer_cpu(buffer, cpu)		\
 	for_each_cpu(cpu, buffer->cpumask)
 
+#define for_each_online_buffer_cpu(buffer, cpu)		\
+	for_each_cpu_and(cpu, buffer->cpumask, cpu_online_mask)
+
 #define TS_SHIFT	27
 #define TS_MASK		((1ULL << TS_SHIFT) - 1)
 #define TS_DELTA_TEST	(~TS_MASK)
@@ -309,8 +312,6 @@
 /* Missed count stored at end */
 #define RB_MISSED_STORED	(1 << 30)
 
-#define RB_MISSED_FLAGS		(RB_MISSED_EVENTS|RB_MISSED_STORED)
-
 struct buffer_data_page {
 	u64		 time_stamp;	/* page time stamp */
 	local_t		 commit;	/* write committed index */
@@ -424,12 +425,27 @@
 struct rb_event_info {
 	u64			ts;
 	u64			delta;
+	u64			before;
+	u64			after;
 	unsigned long		length;
 	struct buffer_page	*tail_page;
 	int			add_timestamp;
 };
 
 /*
+ * Used for the add_timestamp
+ *  NONE
+ *  EXTEND - wants a time extend
+ *  ABSOLUTE - the buffer requests all events to have absolute time stamps
+ *  FORCE - force a full time stamp.
+ */
+enum {
+	RB_ADD_STAMP_NONE		= 0,
+	RB_ADD_STAMP_EXTEND		= BIT(1),
+	RB_ADD_STAMP_ABSOLUTE		= BIT(2),
+	RB_ADD_STAMP_FORCE		= BIT(3)
+};
+/*
  * Used for which event context the event is in.
  *  TRANSITION = 0
  *  NMI     = 1
@@ -448,13 +464,36 @@
 	RB_CTX_MAX
 };
 
+#if BITS_PER_LONG == 32
+#define RB_TIME_32
+#endif
+
+/* To test on 64 bit machines */
+//#define RB_TIME_32
+
+#ifdef RB_TIME_32
+
+struct rb_time_struct {
+	local_t		cnt;
+	local_t		top;
+	local_t		bottom;
+};
+#else
+#include <asm/local64.h>
+struct rb_time_struct {
+	local64_t	time;
+};
+#endif
+typedef struct rb_time_struct rb_time_t;
+
 /*
  * head_page == tail_page && head == tail then buffer is empty.
  */
 struct ring_buffer_per_cpu {
 	int				cpu;
 	atomic_t			record_disabled;
-	struct ring_buffer		*buffer;
+	atomic_t			resize_disabled;
+	struct trace_buffer	*buffer;
 	raw_spinlock_t			reader_lock;	/* serialize readers */
 	arch_spinlock_t			lock;
 	struct lock_class_key		lock_key;
@@ -482,7 +521,8 @@
 	size_t				shortest_full;
 	unsigned long			read;
 	unsigned long			read_bytes;
-	u64				write_stamp;
+	rb_time_t			write_stamp;
+	rb_time_t			before_stamp;
 	u64				read_stamp;
 	/* ring buffer pages to update, > 0 to add, < 0 to remove */
 	long				nr_pages_to_update;
@@ -493,11 +533,10 @@
 	struct rb_irq_work		irq_work;
 };
 
-struct ring_buffer {
+struct trace_buffer {
 	unsigned			flags;
 	int				cpus;
 	atomic_t			record_disabled;
-	atomic_t			resize_disabled;
 	cpumask_var_t			cpumask;
 
 	struct lock_class_key		*reader_lock_key;
@@ -516,12 +555,199 @@
 struct ring_buffer_iter {
 	struct ring_buffer_per_cpu	*cpu_buffer;
 	unsigned long			head;
+	unsigned long			next_event;
 	struct buffer_page		*head_page;
 	struct buffer_page		*cache_reader_page;
 	unsigned long			cache_read;
 	u64				read_stamp;
+	u64				page_stamp;
+	struct ring_buffer_event	*event;
+	int				missed_events;
 };
 
+#ifdef RB_TIME_32
+
+/*
+ * On 32 bit machines, local64_t is very expensive. As the ring
+ * buffer doesn't need all the features of a true 64 bit atomic,
+ * on 32 bit, it uses these functions (64 still uses local64_t).
+ *
+ * For the ring buffer, 64 bit required operations for the time is
+ * the following:
+ *
+ *  - Only need 59 bits (uses 60 to make it even).
+ *  - Reads may fail if it interrupted a modification of the time stamp.
+ *      It will succeed if it did not interrupt another write even if
+ *      the read itself is interrupted by a write.
+ *      It returns whether it was successful or not.
+ *
+ *  - Writes always succeed and will overwrite other writes and writes
+ *      that were done by events interrupting the current write.
+ *
+ *  - A write followed by a read of the same time stamp will always succeed,
+ *      but may not contain the same value.
+ *
+ *  - A cmpxchg will fail if it interrupted another write or cmpxchg.
+ *      Other than that, it acts like a normal cmpxchg.
+ *
+ * The 60 bit time stamp is broken up by 30 bits in a top and bottom half
+ *  (bottom being the least significant 30 bits of the 60 bit time stamp).
+ *
+ * The two most significant bits of each half holds a 2 bit counter (0-3).
+ * Each update will increment this counter by one.
+ * When reading the top and bottom, if the two counter bits match then the
+ *  top and bottom together make a valid 60 bit number.
+ */
+#define RB_TIME_SHIFT	30
+#define RB_TIME_VAL_MASK ((1 << RB_TIME_SHIFT) - 1)
+
+static inline int rb_time_cnt(unsigned long val)
+{
+	return (val >> RB_TIME_SHIFT) & 3;
+}
+
+static inline u64 rb_time_val(unsigned long top, unsigned long bottom)
+{
+	u64 val;
+
+	val = top & RB_TIME_VAL_MASK;
+	val <<= RB_TIME_SHIFT;
+	val |= bottom & RB_TIME_VAL_MASK;
+
+	return val;
+}
+
+static inline bool __rb_time_read(rb_time_t *t, u64 *ret, unsigned long *cnt)
+{
+	unsigned long top, bottom;
+	unsigned long c;
+
+	/*
+	 * If the read is interrupted by a write, then the cnt will
+	 * be different. Loop until both top and bottom have been read
+	 * without interruption.
+	 */
+	do {
+		c = local_read(&t->cnt);
+		top = local_read(&t->top);
+		bottom = local_read(&t->bottom);
+	} while (c != local_read(&t->cnt));
+
+	*cnt = rb_time_cnt(top);
+
+	/* If top and bottom counts don't match, this interrupted a write */
+	if (*cnt != rb_time_cnt(bottom))
+		return false;
+
+	*ret = rb_time_val(top, bottom);
+	return true;
+}
+
+static bool rb_time_read(rb_time_t *t, u64 *ret)
+{
+	unsigned long cnt;
+
+	return __rb_time_read(t, ret, &cnt);
+}
+
+static inline unsigned long rb_time_val_cnt(unsigned long val, unsigned long cnt)
+{
+	return (val & RB_TIME_VAL_MASK) | ((cnt & 3) << RB_TIME_SHIFT);
+}
+
+static inline void rb_time_split(u64 val, unsigned long *top, unsigned long *bottom)
+{
+	*top = (unsigned long)((val >> RB_TIME_SHIFT) & RB_TIME_VAL_MASK);
+	*bottom = (unsigned long)(val & RB_TIME_VAL_MASK);
+}
+
+static inline void rb_time_val_set(local_t *t, unsigned long val, unsigned long cnt)
+{
+	val = rb_time_val_cnt(val, cnt);
+	local_set(t, val);
+}
+
+static void rb_time_set(rb_time_t *t, u64 val)
+{
+	unsigned long cnt, top, bottom;
+
+	rb_time_split(val, &top, &bottom);
+
+	/* Writes always succeed with a valid number even if it gets interrupted. */
+	do {
+		cnt = local_inc_return(&t->cnt);
+		rb_time_val_set(&t->top, top, cnt);
+		rb_time_val_set(&t->bottom, bottom, cnt);
+	} while (cnt != local_read(&t->cnt));
+}
+
+static inline bool
+rb_time_read_cmpxchg(local_t *l, unsigned long expect, unsigned long set)
+{
+	unsigned long ret;
+
+	ret = local_cmpxchg(l, expect, set);
+	return ret == expect;
+}
+
+static int rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
+{
+	unsigned long cnt, top, bottom;
+	unsigned long cnt2, top2, bottom2;
+	u64 val;
+
+	/* The cmpxchg always fails if it interrupted an update */
+	 if (!__rb_time_read(t, &val, &cnt2))
+		 return false;
+
+	 if (val != expect)
+		 return false;
+
+	 cnt = local_read(&t->cnt);
+	 if ((cnt & 3) != cnt2)
+		 return false;
+
+	 cnt2 = cnt + 1;
+
+	 rb_time_split(val, &top, &bottom);
+	 top = rb_time_val_cnt(top, cnt);
+	 bottom = rb_time_val_cnt(bottom, cnt);
+
+	 rb_time_split(set, &top2, &bottom2);
+	 top2 = rb_time_val_cnt(top2, cnt2);
+	 bottom2 = rb_time_val_cnt(bottom2, cnt2);
+
+	if (!rb_time_read_cmpxchg(&t->cnt, cnt, cnt2))
+		return false;
+	if (!rb_time_read_cmpxchg(&t->top, top, top2))
+		return false;
+	if (!rb_time_read_cmpxchg(&t->bottom, bottom, bottom2))
+		return false;
+	return true;
+}
+
+#else /* 64 bits */
+
+/* local64_t always succeeds */
+
+static inline bool rb_time_read(rb_time_t *t, u64 *ret)
+{
+	*ret = local64_read(&t->time);
+	return true;
+}
+static void rb_time_set(rb_time_t *t, u64 val)
+{
+	local64_set(&t->time, val);
+}
+
+static bool rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
+{
+	u64 val;
+	val = local64_cmpxchg(&t->time, expect, set);
+	return val == expect;
+}
+#endif
+
 /**
  * ring_buffer_nr_pages - get the number of buffer pages in the ring buffer
  * @buffer: The ring_buffer to get the number of pages from
@@ -529,7 +755,7 @@
  *
  * Returns the number of pages used by a per_cpu buffer of the ring buffer.
  */
-size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu)
+size_t ring_buffer_nr_pages(struct trace_buffer *buffer, int cpu)
 {
 	return buffer->buffers[cpu]->nr_pages;
 }
@@ -541,7 +767,7 @@
  *
  * Returns the number of pages that have content in the ring buffer.
  */
-size_t ring_buffer_nr_dirty_pages(struct ring_buffer *buffer, int cpu)
+size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu)
 {
 	size_t read;
 	size_t cnt;
@@ -578,15 +804,15 @@
  * ring_buffer_wait - wait for input to the ring buffer
  * @buffer: buffer to wait on
  * @cpu: the cpu buffer to wait on
- * @full: wait until a full page is available, if @cpu != RING_BUFFER_ALL_CPUS
+ * @full: wait until the percentage of pages are available, if @cpu != RING_BUFFER_ALL_CPUS
  *
  * If @cpu == RING_BUFFER_ALL_CPUS then the task will wake up as soon
  * as data is added to any of the @buffer's cpu buffers. Otherwise
  * it will wait for data to be added to a specific cpu buffer.
  */
-int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full)
+int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full)
 {
-	struct ring_buffer_per_cpu *uninitialized_var(cpu_buffer);
+	struct ring_buffer_per_cpu *cpu_buffer;
 	DEFINE_WAIT(wait);
 	struct rb_irq_work *work;
 	int ret = 0;
@@ -695,7 +921,7 @@
  * Returns EPOLLIN | EPOLLRDNORM if data exists in the buffers,
  * zero otherwise.
  */
-__poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
+__poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
 			  struct file *filp, poll_table *poll_table)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -753,13 +979,21 @@
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
-static inline u64 rb_time_stamp(struct ring_buffer *buffer)
+static inline u64 rb_time_stamp(struct trace_buffer *buffer)
 {
+	u64 ts;
+
+	/* Skip retpolines :-( */
+	if (IS_ENABLED(CONFIG_RETPOLINE) && likely(buffer->clock == trace_clock_local))
+		ts = trace_clock_local();
+	else
+		ts = buffer->clock();
+
 	/* shift to debug/test normalization and TIME_EXTENTS */
-	return buffer->clock() << DEBUG_SHIFT;
+	return ts << DEBUG_SHIFT;
 }
 
-u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
+u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu)
 {
 	u64 time;
 
@@ -771,7 +1005,7 @@
 }
 EXPORT_SYMBOL_GPL(ring_buffer_time_stamp);
 
-void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
+void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer,
 				      int cpu, u64 *ts)
 {
 	/* Just stupid testing the normalize function and deltas */
@@ -1294,7 +1528,7 @@
 }
 
 static struct ring_buffer_per_cpu *
-rb_allocate_cpu_buffer(struct ring_buffer *buffer, long nr_pages, int cpu)
+rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_page *bpage;
@@ -1379,16 +1613,17 @@
  * __ring_buffer_alloc - allocate a new ring_buffer
  * @size: the size in bytes per cpu that is needed.
  * @flags: attributes to set for the ring buffer.
+ * @key: ring buffer reader_lock_key.
  *
  * Currently the only flag that is available is the RB_FL_OVERWRITE
  * flag. This flag means that the buffer will overwrite old data
  * when the buffer wraps. If this flag is not set, the buffer will
  * drop data when the tail hits the head.
  */
-struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
+struct trace_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
 					struct lock_class_key *key)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	long nr_pages;
 	int bsize;
 	int cpu;
@@ -1458,7 +1693,7 @@
  * @buffer: the buffer to free.
  */
 void
-ring_buffer_free(struct ring_buffer *buffer)
+ring_buffer_free(struct trace_buffer *buffer)
 {
 	int cpu;
 
@@ -1474,18 +1709,18 @@
 }
 EXPORT_SYMBOL_GPL(ring_buffer_free);
 
-void ring_buffer_set_clock(struct ring_buffer *buffer,
+void ring_buffer_set_clock(struct trace_buffer *buffer,
 			   u64 (*clock)(void))
 {
 	buffer->clock = clock;
 }
 
-void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs)
+void ring_buffer_set_time_stamp_abs(struct trace_buffer *buffer, bool abs)
 {
 	buffer->time_stamp_abs = abs;
 }
 
-bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer)
+bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer)
 {
 	return buffer->time_stamp_abs;
 }
@@ -1723,7 +1958,7 @@
  *
  * Returns 0 on success and < 0 on failure.
  */
-int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
+int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
 			int cpu_id)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -1749,18 +1984,24 @@
 
 	size = nr_pages * BUF_PAGE_SIZE;
 
-	/*
-	 * Don't succeed if resizing is disabled, as a reader might be
-	 * manipulating the ring buffer and is expecting a sane state while
-	 * this is true.
-	 */
-	if (atomic_read(&buffer->resize_disabled))
-		return -EBUSY;
-
 	/* prevent another thread from changing buffer sizes */
 	mutex_lock(&buffer->mutex);
 
+
 	if (cpu_id == RING_BUFFER_ALL_CPUS) {
+		/*
+		 * Don't succeed if resizing is disabled, as a reader might be
+		 * manipulating the ring buffer and is expecting a sane state while
+		 * this is true.
+		 */
+		for_each_buffer_cpu(buffer, cpu) {
+			cpu_buffer = buffer->buffers[cpu];
+			if (atomic_read(&cpu_buffer->resize_disabled)) {
+				err = -EBUSY;
+				goto out_err_unlock;
+			}
+		}
+
 		/* calculate the pages to update */
 		for_each_buffer_cpu(buffer, cpu) {
 			cpu_buffer = buffer->buffers[cpu];
@@ -1828,6 +2069,16 @@
 		if (nr_pages == cpu_buffer->nr_pages)
 			goto out;
 
+		/*
+		 * Don't succeed if resizing is disabled, as a reader might be
+		 * manipulating the ring buffer and is expecting a sane state while
+		 * this is true.
+		 */
+		if (atomic_read(&cpu_buffer->resize_disabled)) {
+			err = -EBUSY;
+			goto out_err_unlock;
+		}
+
 		cpu_buffer->nr_pages_to_update = nr_pages -
 						cpu_buffer->nr_pages;
 
@@ -1897,12 +2148,13 @@
 			free_buffer_page(bpage);
 		}
 	}
+ out_err_unlock:
 	mutex_unlock(&buffer->mutex);
 	return err;
 }
 EXPORT_SYMBOL_GPL(ring_buffer_resize);
 
-void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
+void ring_buffer_change_overwrite(struct trace_buffer *buffer, int val)
 {
 	mutex_lock(&buffer->mutex);
 	if (val)
@@ -1925,17 +2177,65 @@
 			       cpu_buffer->reader_page->read);
 }
 
-static __always_inline struct ring_buffer_event *
-rb_iter_head_event(struct ring_buffer_iter *iter)
-{
-	return __rb_page_index(iter->head_page, iter->head);
-}
-
 static __always_inline unsigned rb_page_commit(struct buffer_page *bpage)
 {
 	return local_read(&bpage->page->commit);
 }
 
+static struct ring_buffer_event *
+rb_iter_head_event(struct ring_buffer_iter *iter)
+{
+	struct ring_buffer_event *event;
+	struct buffer_page *iter_head_page = iter->head_page;
+	unsigned long commit;
+	unsigned length;
+
+	if (iter->head != iter->next_event)
+		return iter->event;
+
+	/*
+	 * When the writer goes across pages, it issues a cmpxchg which
+	 * is a mb(), which will synchronize with the rmb here.
+	 * (see rb_tail_page_update() and __rb_reserve_next())
+	 */
+	commit = rb_page_commit(iter_head_page);
+	smp_rmb();
+	event = __rb_page_index(iter_head_page, iter->head);
+	length = rb_event_length(event);
+
+	/*
+	 * READ_ONCE() doesn't work on functions and we don't want the
+	 * compiler doing any crazy optimizations with length.
+	 */
+	barrier();
+
+	if ((iter->head + length) > commit || length > BUF_MAX_DATA_SIZE)
+		/* Writer corrupted the read? */
+		goto reset;
+
+	memcpy(iter->event, event, length);
+	/*
+	 * If the page stamp is still the same after this rmb() then the
+	 * event was safely copied without the writer entering the page.
+	 */
+	smp_rmb();
+
+	/* Make sure the page didn't change since we read this */
+	if (iter->page_stamp != iter_head_page->page->time_stamp ||
+	    commit > rb_page_commit(iter_head_page))
+		goto reset;
+
+	iter->next_event = iter->head + length;
+	return iter->event;
+ reset:
+	/* Reset to the beginning */
+	iter->page_stamp = iter->read_stamp = iter->head_page->page->time_stamp;
+	iter->head = 0;
+	iter->next_event = 0;
+	iter->missed_events = 1;
+	return NULL;
+}
+
 /* Size is determined by what has been committed */
 static __always_inline unsigned rb_page_size(struct buffer_page *bpage)
 {
@@ -1971,8 +2271,9 @@
 	else
 		rb_inc_page(cpu_buffer, &iter->head_page);
 
-	iter->read_stamp = iter->head_page->page->time_stamp;
+	iter->page_stamp = iter->read_stamp = iter->head_page->page->time_stamp;
 	iter->head = 0;
+	iter->next_event = 0;
 }
 
 /*
@@ -2217,7 +2518,7 @@
 {
 	struct buffer_page *tail_page = info->tail_page;
 	struct buffer_page *commit_page = cpu_buffer->commit_page;
-	struct ring_buffer *buffer = cpu_buffer->buffer;
+	struct trace_buffer *buffer = cpu_buffer->buffer;
 	struct buffer_page *next_page;
 	int ret;
 
@@ -2314,8 +2615,8 @@
 	return NULL;
 }
 
-/* Slow path, do not inline */
-static noinline struct ring_buffer_event *
+/* Slow path */
+static struct ring_buffer_event *
 rb_add_time_stamp(struct ring_buffer_event *event, u64 delta, bool abs)
 {
 	if (abs)
@@ -2339,13 +2640,73 @@
 static inline bool rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
 				     struct ring_buffer_event *event);
 
+#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
+static inline bool sched_clock_stable(void)
+{
+	return true;
+}
+#endif
+
+static void
+rb_check_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
+		   struct rb_event_info *info)
+{
+	u64 write_stamp;
+
+	WARN_ONCE(1, "Delta way too big! %llu ts=%llu before=%llu after=%llu write stamp=%llu\n%s",
+		  (unsigned long long)info->delta,
+		  (unsigned long long)info->ts,
+		  (unsigned long long)info->before,
+		  (unsigned long long)info->after,
+		  (unsigned long long)(rb_time_read(&cpu_buffer->write_stamp, &write_stamp) ? write_stamp : 0),
+		  sched_clock_stable() ? "" :
+		  "If you just came from a suspend/resume,\n"
+		  "please switch to the trace global clock:\n"
+		  "  echo global > /sys/kernel/debug/tracing/trace_clock\n"
+		  "or add trace_clock=global to the kernel command line\n");
+}
+
+static void rb_add_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
+				      struct ring_buffer_event **event,
+				      struct rb_event_info *info,
+				      u64 *delta,
+				      unsigned int *length)
+{
+	bool abs = info->add_timestamp &
+		(RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE);
+
+	if (unlikely(info->delta > (1ULL << 59))) {
+		/* did the clock go backwards */
+		if (info->before == info->after && info->before > info->ts) {
+			/* not interrupted */
+			static int once;
+
+			/*
+			 * This is possible with a recalibrating of the TSC.
+			 * Do not produce a call stack, but just report it.
+			 */
+			if (!once) {
+				once++;
+				pr_warn("Ring buffer clock went backwards: %llu -> %llu\n",
+					info->before, info->ts);
+			}
+		} else
+			rb_check_timestamp(cpu_buffer, info);
+		if (!abs)
+			info->delta = 0;
+	}
+	*event = rb_add_time_stamp(*event, info->delta, abs);
+	*length -= RB_LEN_TIME_EXTEND;
+	*delta = 0;
+}
+
 /**
  * rb_update_event - update event type and data
+ * @cpu_buffer: The per cpu buffer of the @event
  * @event: the event to update
- * @type: the type of event
- * @length: the size of the event field in the ring buffer
+ * @info: The info to update the @event with (contains length and delta)
  *
- * Update the type and data fields of the event. The length
+ * Update the type and data fields of the @event. The length
  * is the actual size that is written to the ring buffer,
  * and with this, we can determine what to place into the
  * data field.
@@ -2358,21 +2719,12 @@
 	unsigned length = info->length;
 	u64 delta = info->delta;
 
-	/* Only a commit updates the timestamp */
-	if (unlikely(!rb_event_is_commit(cpu_buffer, event)))
-		delta = 0;
-
 	/*
 	 * If we need to add a timestamp, then we
 	 * add it to the start of the reserved space.
 	 */
-	if (unlikely(info->add_timestamp)) {
-		bool abs = ring_buffer_time_stamp_abs(cpu_buffer->buffer);
-
-		event = rb_add_time_stamp(event, abs ? info->delta : delta, abs);
-		length -= RB_LEN_TIME_EXTEND;
-		delta = 0;
-	}
+	if (unlikely(info->add_timestamp))
+		rb_add_timestamp(cpu_buffer, &event, info, &delta, &length);
 
 	event->time_delta = delta;
 	length -= RB_EVNT_HDR_SIZE;
@@ -2415,12 +2767,38 @@
 	return length;
 }
 
-#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
-static inline bool sched_clock_stable(void)
+static __always_inline bool
+rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
+		   struct ring_buffer_event *event)
 {
-	return true;
+	unsigned long addr = (unsigned long)event;
+	unsigned long index;
+
+	index = rb_event_index(event);
+	addr &= PAGE_MASK;
+
+	return cpu_buffer->commit_page->page == (void *)addr &&
+		rb_commit_index(cpu_buffer) == index;
 }
-#endif
+
+static u64 rb_time_delta(struct ring_buffer_event *event)
+{
+	switch (event->type_len) {
+	case RINGBUF_TYPE_PADDING:
+		return 0;
+
+	case RINGBUF_TYPE_TIME_EXTEND:
+		return ring_buffer_event_time_stamp(event);
+
+	case RINGBUF_TYPE_TIME_STAMP:
+		return 0;
+
+	case RINGBUF_TYPE_DATA:
+		return event->time_delta;
+	default:
+		return 0;
+	}
+}
 
 static inline int
 rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
@@ -2430,6 +2808,8 @@
 	struct buffer_page *bpage;
 	unsigned long index;
 	unsigned long addr;
+	u64 write_stamp;
+	u64 delta;
 
 	new_index = rb_event_index(event);
 	old_index = new_index + rb_event_ts_length(event);
@@ -2438,10 +2818,43 @@
 
 	bpage = READ_ONCE(cpu_buffer->tail_page);
 
+	delta = rb_time_delta(event);
+
+	if (!rb_time_read(&cpu_buffer->write_stamp, &write_stamp))
+		return 0;
+
+	/* Make sure the write stamp is read before testing the location */
+	barrier();
+
 	if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) {
 		unsigned long write_mask =
 			local_read(&bpage->write) & ~RB_WRITE_MASK;
 		unsigned long event_length = rb_event_length(event);
+
+		/* Something came in, can't discard */
+		if (!rb_time_cmpxchg(&cpu_buffer->write_stamp,
+				       write_stamp, write_stamp - delta))
+			return 0;
+
+		/*
+		 * It's possible that the event time delta is zero
+		 * (has the same time stamp as the previous event)
+		 * in which case write_stamp and before_stamp could
+		 * be the same. In such a case, force before_stamp
+		 * to be different than write_stamp. It doesn't
+		 * matter what it is, as long as its different.
+		 */
+		if (!delta)
+			rb_time_set(&cpu_buffer->before_stamp, 0);
+
+		/*
+		 * If an event were to come in now, it would see that the
+		 * write_stamp and the before_stamp are different, and assume
+		 * that this event just added itself before updating
+		 * the write stamp. The interrupting event will fix the
+		 * write stamp for us, and use the before stamp as its delta.
+		 */
+
 		/*
 		 * This is on the tail page. It is possible that
 		 * a write could come in and move the tail page
@@ -2493,10 +2906,6 @@
 		local_set(&cpu_buffer->commit_page->page->commit,
 			  rb_page_write(cpu_buffer->commit_page));
 		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
-		/* Only update the write stamp if the page has an event */
-		if (rb_page_write(cpu_buffer->commit_page))
-			cpu_buffer->write_stamp =
-				cpu_buffer->commit_page->page->time_stamp;
 		/* add barrier to keep gcc from optimizing too much */
 		barrier();
 	}
@@ -2568,59 +2977,15 @@
 		event->time_delta = 1;
 }
 
-static __always_inline bool
-rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
-		   struct ring_buffer_event *event)
-{
-	unsigned long addr = (unsigned long)event;
-	unsigned long index;
-
-	index = rb_event_index(event);
-	addr &= PAGE_MASK;
-
-	return cpu_buffer->commit_page->page == (void *)addr &&
-		rb_commit_index(cpu_buffer) == index;
-}
-
-static __always_inline void
-rb_update_write_stamp(struct ring_buffer_per_cpu *cpu_buffer,
-		      struct ring_buffer_event *event)
-{
-	u64 delta;
-
-	/*
-	 * The event first in the commit queue updates the
-	 * time stamp.
-	 */
-	if (rb_event_is_commit(cpu_buffer, event)) {
-		/*
-		 * A commit event that is first on a page
-		 * updates the write timestamp with the page stamp
-		 */
-		if (!rb_event_index(event))
-			cpu_buffer->write_stamp =
-				cpu_buffer->commit_page->page->time_stamp;
-		else if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) {
-			delta = ring_buffer_event_time_stamp(event);
-			cpu_buffer->write_stamp += delta;
-		} else if (event->type_len == RINGBUF_TYPE_TIME_STAMP) {
-			delta = ring_buffer_event_time_stamp(event);
-			cpu_buffer->write_stamp = delta;
-		} else
-			cpu_buffer->write_stamp += event->time_delta;
-	}
-}
-
 static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
 		      struct ring_buffer_event *event)
 {
 	local_inc(&cpu_buffer->entries);
-	rb_update_write_stamp(cpu_buffer, event);
 	rb_end_commit(cpu_buffer);
 }
 
 static __always_inline void
-rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
+rb_wakeups(struct trace_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
 {
 	size_t nr_pages;
 	size_t dirty;
@@ -2776,7 +3141,7 @@
  * Call this function before calling another ring_buffer_lock_reserve() and
  * call ring_buffer_nest_end() after the nested ring_buffer_unlock_commit().
  */
-void ring_buffer_nest_start(struct ring_buffer *buffer)
+void ring_buffer_nest_start(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	int cpu;
@@ -2796,7 +3161,7 @@
  * Must be called after ring_buffer_nest_start() and after the
  * ring_buffer_unlock_commit().
  */
-void ring_buffer_nest_end(struct ring_buffer *buffer)
+void ring_buffer_nest_end(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	int cpu;
@@ -2818,7 +3183,7 @@
  *
  * Must be paired with ring_buffer_lock_reserve.
  */
-int ring_buffer_unlock_commit(struct ring_buffer *buffer,
+int ring_buffer_unlock_commit(struct trace_buffer *buffer,
 			      struct ring_buffer_event *event)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -2838,58 +3203,136 @@
 }
 EXPORT_SYMBOL_GPL(ring_buffer_unlock_commit);
 
-static noinline void
-rb_handle_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
-		    struct rb_event_info *info)
-{
-	WARN_ONCE(info->delta > (1ULL << 59),
-		  KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s",
-		  (unsigned long long)info->delta,
-		  (unsigned long long)info->ts,
-		  (unsigned long long)cpu_buffer->write_stamp,
-		  sched_clock_stable() ? "" :
-		  "If you just came from a suspend/resume,\n"
-		  "please switch to the trace global clock:\n"
-		  "  echo global > /sys/kernel/debug/tracing/trace_clock\n"
-		  "or add trace_clock=global to the kernel command line\n");
-	info->add_timestamp = 1;
-}
-
 static struct ring_buffer_event *
 __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 		  struct rb_event_info *info)
 {
 	struct ring_buffer_event *event;
 	struct buffer_page *tail_page;
-	unsigned long tail, write;
-
-	/*
-	 * If the time delta since the last event is too big to
-	 * hold in the time field of the event, then we append a
-	 * TIME EXTEND event ahead of the data event.
-	 */
-	if (unlikely(info->add_timestamp))
-		info->length += RB_LEN_TIME_EXTEND;
+	unsigned long tail, write, w;
+	bool a_ok;
+	bool b_ok;
 
 	/* Don't let the compiler play games with cpu_buffer->tail_page */
 	tail_page = info->tail_page = READ_ONCE(cpu_buffer->tail_page);
-	write = local_add_return(info->length, &tail_page->write);
+
+ /*A*/	w = local_read(&tail_page->write) & RB_WRITE_MASK;
+	barrier();
+	b_ok = rb_time_read(&cpu_buffer->before_stamp, &info->before);
+	a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+	barrier();
+	info->ts = rb_time_stamp(cpu_buffer->buffer);
+
+	if ((info->add_timestamp & RB_ADD_STAMP_ABSOLUTE)) {
+		info->delta = info->ts;
+	} else {
+		/*
+		 * If interrupting an event time update, we may need an
+		 * absolute timestamp.
+		 * Don't bother if this is the start of a new page (w == 0).
+		 */
+		if (unlikely(!a_ok || !b_ok || (info->before != info->after && w))) {
+			info->add_timestamp |= RB_ADD_STAMP_FORCE | RB_ADD_STAMP_EXTEND;
+			info->length += RB_LEN_TIME_EXTEND;
+		} else {
+			info->delta = info->ts - info->after;
+			if (unlikely(test_time_stamp(info->delta))) {
+				info->add_timestamp |= RB_ADD_STAMP_EXTEND;
+				info->length += RB_LEN_TIME_EXTEND;
+			}
+		}
+	}
+
+ /*B*/	rb_time_set(&cpu_buffer->before_stamp, info->ts);
+
+ /*C*/	write = local_add_return(info->length, &tail_page->write);
 
 	/* set write to only the index of the write */
 	write &= RB_WRITE_MASK;
+
 	tail = write - info->length;
 
+	/* See if we shot pass the end of this buffer page */
+	if (unlikely(write > BUF_PAGE_SIZE)) {
+		/* before and after may now different, fix it up*/
+		b_ok = rb_time_read(&cpu_buffer->before_stamp, &info->before);
+		a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+		if (a_ok && b_ok && info->before != info->after)
+			(void)rb_time_cmpxchg(&cpu_buffer->before_stamp,
+					      info->before, info->after);
+		return rb_move_tail(cpu_buffer, tail, info);
+	}
+
+	if (likely(tail == w)) {
+		u64 save_before;
+		bool s_ok;
+
+		/* Nothing interrupted us between A and C */
+ /*D*/		rb_time_set(&cpu_buffer->write_stamp, info->ts);
+		barrier();
+ /*E*/		s_ok = rb_time_read(&cpu_buffer->before_stamp, &save_before);
+		RB_WARN_ON(cpu_buffer, !s_ok);
+		if (likely(!(info->add_timestamp &
+			     (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE))))
+			/* This did not interrupt any time update */
+			info->delta = info->ts - info->after;
+		else
+			/* Just use full timestamp for inerrupting event */
+			info->delta = info->ts;
+		barrier();
+		if (unlikely(info->ts != save_before)) {
+			/* SLOW PATH - Interrupted between C and E */
+
+			a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+			RB_WARN_ON(cpu_buffer, !a_ok);
+
+			/* Write stamp must only go forward */
+			if (save_before > info->after) {
+				/*
+				 * We do not care about the result, only that
+				 * it gets updated atomically.
+				 */
+				(void)rb_time_cmpxchg(&cpu_buffer->write_stamp,
+						      info->after, save_before);
+			}
+		}
+	} else {
+		u64 ts;
+		/* SLOW PATH - Interrupted between A and C */
+		a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+		/* Was interrupted before here, write_stamp must be valid */
+		RB_WARN_ON(cpu_buffer, !a_ok);
+		ts = rb_time_stamp(cpu_buffer->buffer);
+		barrier();
+ /*E*/		if (write == (local_read(&tail_page->write) & RB_WRITE_MASK) &&
+		    info->after < ts &&
+		    rb_time_cmpxchg(&cpu_buffer->write_stamp,
+				    info->after, ts)) {
+			/* Nothing came after this event between C and E */
+			info->delta = ts - info->after;
+			info->ts = ts;
+		} else {
+			/*
+			 * Interrupted beween C and E:
+			 * Lost the previous events time stamp. Just set the
+			 * delta to zero, and this will be the same time as
+			 * the event this event interrupted. And the events that
+			 * came after this will still be correct (as they would
+			 * have built their delta on the previous event.
+			 */
+			info->delta = 0;
+		}
+		info->add_timestamp &= ~RB_ADD_STAMP_FORCE;
+	}
+
 	/*
 	 * If this is the first commit on the page, then it has the same
 	 * timestamp as the page itself.
 	 */
-	if (!tail && !ring_buffer_time_stamp_abs(cpu_buffer->buffer))
+	if (unlikely(!tail && !(info->add_timestamp &
+				(RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE))))
 		info->delta = 0;
 
-	/* See if we shot pass the end of this buffer page */
-	if (unlikely(write > BUF_PAGE_SIZE))
-		return rb_move_tail(cpu_buffer, tail, info);
-
 	/* We reserved something on the buffer */
 
 	event = __rb_page_index(tail_page, tail);
@@ -2901,7 +3344,7 @@
 	 * If this is the first commit on the page, then update
 	 * its timestamp.
 	 */
-	if (!tail)
+	if (unlikely(!tail))
 		tail_page->page->time_stamp = info->ts;
 
 	/* account for these added bytes */
@@ -2911,16 +3354,17 @@
 }
 
 static __always_inline struct ring_buffer_event *
-rb_reserve_next_event(struct ring_buffer *buffer,
+rb_reserve_next_event(struct trace_buffer *buffer,
 		      struct ring_buffer_per_cpu *cpu_buffer,
 		      unsigned long length)
 {
 	struct ring_buffer_event *event;
 	struct rb_event_info info;
 	int nr_loops = 0;
-	u64 diff;
+	int add_ts_default;
 
 	rb_start_commit(cpu_buffer);
+	/* The commit page can not change after this */
 
 #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
 	/*
@@ -2938,8 +3382,16 @@
 #endif
 
 	info.length = rb_calculate_event_length(length);
+
+	if (ring_buffer_time_stamp_abs(cpu_buffer->buffer)) {
+		add_ts_default = RB_ADD_STAMP_ABSOLUTE;
+		info.length += RB_LEN_TIME_EXTEND;
+	} else {
+		add_ts_default = RB_ADD_STAMP_NONE;
+	}
+
  again:
-	info.add_timestamp = 0;
+	info.add_timestamp = add_ts_default;
 	info.delta = 0;
 
 	/*
@@ -2954,35 +3406,16 @@
 	if (RB_WARN_ON(cpu_buffer, ++nr_loops > 1000))
 		goto out_fail;
 
-	info.ts = rb_time_stamp(cpu_buffer->buffer);
-	diff = info.ts - cpu_buffer->write_stamp;
-
-	/* make sure this diff is calculated here */
-	barrier();
-
-	if (ring_buffer_time_stamp_abs(buffer)) {
-		info.delta = info.ts;
-		rb_handle_timestamp(cpu_buffer, &info);
-	} else /* Did the write stamp get updated already? */
-		if (likely(info.ts >= cpu_buffer->write_stamp)) {
-		info.delta = diff;
-		if (unlikely(test_time_stamp(info.delta)))
-			rb_handle_timestamp(cpu_buffer, &info);
-	}
-
 	event = __rb_reserve_next(cpu_buffer, &info);
 
 	if (unlikely(PTR_ERR(event) == -EAGAIN)) {
-		if (info.add_timestamp)
+		if (info.add_timestamp & (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_EXTEND))
 			info.length -= RB_LEN_TIME_EXTEND;
 		goto again;
 	}
 
-	if (!event)
-		goto out_fail;
-
-	return event;
-
+	if (likely(event))
+		return event;
  out_fail:
 	rb_end_commit(cpu_buffer);
 	return NULL;
@@ -3004,7 +3437,7 @@
  * If NULL is returned, then nothing has been allocated or locked.
  */
 struct ring_buffer_event *
-ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
+ring_buffer_lock_reserve(struct trace_buffer *buffer, unsigned long length)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
@@ -3105,7 +3538,7 @@
  * If this function is called, do not call ring_buffer_unlock_commit on
  * the event.
  */
-void ring_buffer_discard_commit(struct ring_buffer *buffer,
+void ring_buffer_discard_commit(struct trace_buffer *buffer,
 				struct ring_buffer_event *event)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -3128,11 +3561,6 @@
 	if (rb_try_to_discard(cpu_buffer, event))
 		goto out;
 
-	/*
-	 * The commit is still visible by the reader, so we
-	 * must still update the timestamp.
-	 */
-	rb_update_write_stamp(cpu_buffer, event);
  out:
 	rb_end_commit(cpu_buffer);
 
@@ -3156,7 +3584,7 @@
  * Note, like ring_buffer_lock_reserve, the length is the length of the data
  * and not the length of the event which would hold the header.
  */
-int ring_buffer_write(struct ring_buffer *buffer,
+int ring_buffer_write(struct trace_buffer *buffer,
 		      unsigned long length,
 		      void *data)
 {
@@ -3256,7 +3684,7 @@
  *
  * The caller should call synchronize_rcu() after this.
  */
-void ring_buffer_record_disable(struct ring_buffer *buffer)
+void ring_buffer_record_disable(struct trace_buffer *buffer)
 {
 	atomic_inc(&buffer->record_disabled);
 }
@@ -3269,7 +3697,7 @@
  * Note, multiple disables will need the same number of enables
  * to truly enable the writing (much like preempt_disable).
  */
-void ring_buffer_record_enable(struct ring_buffer *buffer)
+void ring_buffer_record_enable(struct trace_buffer *buffer)
 {
 	atomic_dec(&buffer->record_disabled);
 }
@@ -3286,7 +3714,7 @@
  * it works like an on/off switch, where as the disable() version
  * must be paired with a enable().
  */
-void ring_buffer_record_off(struct ring_buffer *buffer)
+void ring_buffer_record_off(struct trace_buffer *buffer)
 {
 	unsigned int rd;
 	unsigned int new_rd;
@@ -3309,7 +3737,7 @@
  * it works like an on/off switch, where as the enable() version
  * must be paired with a disable().
  */
-void ring_buffer_record_on(struct ring_buffer *buffer)
+void ring_buffer_record_on(struct trace_buffer *buffer)
 {
 	unsigned int rd;
 	unsigned int new_rd;
@@ -3327,7 +3755,7 @@
  *
  * Returns true if the ring buffer is in a state that it accepts writes.
  */
-bool ring_buffer_record_is_on(struct ring_buffer *buffer)
+bool ring_buffer_record_is_on(struct trace_buffer *buffer)
 {
 	return !atomic_read(&buffer->record_disabled);
 }
@@ -3343,7 +3771,7 @@
  * ring_buffer_record_disable(), as that is a temporary disabling of
  * the ring buffer.
  */
-bool ring_buffer_record_is_set_on(struct ring_buffer *buffer)
+bool ring_buffer_record_is_set_on(struct trace_buffer *buffer)
 {
 	return !(atomic_read(&buffer->record_disabled) & RB_BUFFER_OFF);
 }
@@ -3358,7 +3786,7 @@
  *
  * The caller should call synchronize_rcu() after this.
  */
-void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3378,7 +3806,7 @@
  * Note, multiple disables will need the same number of enables
  * to truly enable the writing (much like preempt_disable).
  */
-void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3408,7 +3836,7 @@
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to read from.
  */
-u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu)
+u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu)
 {
 	unsigned long flags;
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -3441,7 +3869,7 @@
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to read from.
  */
-unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_bytes_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3461,7 +3889,7 @@
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to get the entries from.
  */
-unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_entries_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3480,7 +3908,7 @@
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to get the number of overruns from
  */
-unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_overrun_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3503,7 +3931,7 @@
  * @cpu: The per CPU buffer to get the number of overruns from
  */
 unsigned long
-ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3525,7 +3953,7 @@
  * @cpu: The per CPU buffer to get the number of overruns from
  */
 unsigned long
-ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3546,7 +3974,7 @@
  * @cpu: The per CPU buffer to get the number of events read
  */
 unsigned long
-ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3565,7 +3993,7 @@
  * Returns the total number of entries in the ring buffer
  * (all CPU entries)
  */
-unsigned long ring_buffer_entries(struct ring_buffer *buffer)
+unsigned long ring_buffer_entries(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long entries = 0;
@@ -3588,7 +4016,7 @@
  * Returns the total number of overruns in the ring buffer
  * (all CPU entries)
  */
-unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
+unsigned long ring_buffer_overruns(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long overruns = 0;
@@ -3611,14 +4039,18 @@
 	/* Iterator usage is expected to have record disabled */
 	iter->head_page = cpu_buffer->reader_page;
 	iter->head = cpu_buffer->reader_page->read;
+	iter->next_event = iter->head;
 
 	iter->cache_reader_page = iter->head_page;
 	iter->cache_read = cpu_buffer->read;
 
-	if (iter->head)
+	if (iter->head) {
 		iter->read_stamp = cpu_buffer->read_stamp;
-	else
+		iter->page_stamp = cpu_buffer->reader_page->page->time_stamp;
+	} else {
 		iter->read_stamp = iter->head_page->page->time_stamp;
+		iter->page_stamp = iter->read_stamp;
+	}
 }
 
 /**
@@ -3654,17 +4086,38 @@
 	struct buffer_page *reader;
 	struct buffer_page *head_page;
 	struct buffer_page *commit_page;
+	struct buffer_page *curr_commit_page;
 	unsigned commit;
+	u64 curr_commit_ts;
+	u64 commit_ts;
 
 	cpu_buffer = iter->cpu_buffer;
-
-	/* Remember, trace recording is off when iterator is in use */
 	reader = cpu_buffer->reader_page;
 	head_page = cpu_buffer->head_page;
 	commit_page = cpu_buffer->commit_page;
-	commit = rb_page_commit(commit_page);
+	commit_ts = commit_page->page->time_stamp;
 
-	return ((iter->head_page == commit_page && iter->head == commit) ||
+	/*
+	 * When the writer goes across pages, it issues a cmpxchg which
+	 * is a mb(), which will synchronize with the rmb here.
+	 * (see rb_tail_page_update())
+	 */
+	smp_rmb();
+	commit = rb_page_commit(commit_page);
+	/* We want to make sure that the commit page doesn't change */
+	smp_rmb();
+
+	/* Make sure commit page didn't change */
+	curr_commit_page = READ_ONCE(cpu_buffer->commit_page);
+	curr_commit_ts = READ_ONCE(curr_commit_page->page->time_stamp);
+
+	/* If the commit page changed, then there's more data */
+	if (curr_commit_page != commit_page ||
+	    curr_commit_ts != commit_ts)
+		return 0;
+
+	/* Still racy, as it may return a false positive, but that's OK */
+	return ((iter->head_page == commit_page && iter->head >= commit) ||
 		(iter->head_page == reader && commit_page == head_page &&
 		 head_page->read == commit &&
 		 iter->head == rb_page_commit(cpu_buffer->reader_page)));
@@ -3696,7 +4149,7 @@
 		return;
 
 	default:
-		BUG();
+		RB_WARN_ON(cpu_buffer, 1);
 	}
 	return;
 }
@@ -3726,7 +4179,7 @@
 		return;
 
 	default:
-		BUG();
+		RB_WARN_ON(iter->cpu_buffer, 1);
 	}
 	return;
 }
@@ -3892,15 +4345,22 @@
 static void rb_advance_iter(struct ring_buffer_iter *iter)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
-	struct ring_buffer_event *event;
-	unsigned length;
 
 	cpu_buffer = iter->cpu_buffer;
 
+	/* If head == next_event then we need to jump to the next event */
+	if (iter->head == iter->next_event) {
+		/* If the event gets overwritten again, there's nothing to do */
+		if (rb_iter_head_event(iter) == NULL)
+			return;
+	}
+
+	iter->head = iter->next_event;
+
 	/*
 	 * Check if we are at the end of the buffer.
 	 */
-	if (iter->head >= rb_page_size(iter->head_page)) {
+	if (iter->next_event >= rb_page_size(iter->head_page)) {
 		/* discarded commits can make the page empty */
 		if (iter->head_page == cpu_buffer->commit_page)
 			return;
@@ -3908,27 +4368,7 @@
 		return;
 	}
 
-	event = rb_iter_head_event(iter);
-
-	length = rb_event_length(event);
-
-	/*
-	 * This should not be called to advance the header if we are
-	 * at the tail of the buffer.
-	 */
-	if (RB_WARN_ON(cpu_buffer,
-		       (iter->head_page == cpu_buffer->commit_page) &&
-		       (iter->head + length > rb_commit_index(cpu_buffer))))
-		return;
-
-	rb_update_iter_read_stamp(iter, event);
-
-	iter->head += length;
-
-	/* check for end of page padding */
-	if ((iter->head >= rb_page_size(iter->head_page)) &&
-	    (iter->head_page != cpu_buffer->commit_page))
-		rb_inc_iter(iter);
+	rb_update_iter_read_stamp(iter, iter->event);
 }
 
 static int rb_lost_events(struct ring_buffer_per_cpu *cpu_buffer)
@@ -4002,7 +4442,7 @@
 		return event;
 
 	default:
-		BUG();
+		RB_WARN_ON(cpu_buffer, 1);
 	}
 
 	return NULL;
@@ -4012,7 +4452,7 @@
 static struct ring_buffer_event *
 rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
 	int nr_loops = 0;
@@ -4037,14 +4477,13 @@
 		return NULL;
 
 	/*
-	 * We repeat when a time extend is encountered or we hit
-	 * the end of the page. Since the time extend is always attached
-	 * to a data event, we should never loop more than three times.
-	 * Once for going to next page, once on time extend, and
-	 * finally once to get the event.
-	 * (We never hit the following condition more than thrice).
+	 * As the writer can mess with what the iterator is trying
+	 * to read, just give up if we fail to get an event after
+	 * three tries. The iterator is not as reliable when reading
+	 * the ring buffer with an active write as the consumer is.
+	 * Do not warn if the three failures is reached.
 	 */
-	if (RB_WARN_ON(cpu_buffer, ++nr_loops > 3))
+	if (++nr_loops > 3)
 		return NULL;
 
 	if (rb_per_cpu_empty(cpu_buffer))
@@ -4056,6 +4495,8 @@
 	}
 
 	event = rb_iter_head_event(iter);
+	if (!event)
+		goto again;
 
 	switch (event->type_len) {
 	case RINGBUF_TYPE_PADDING:
@@ -4090,7 +4531,7 @@
 		return event;
 
 	default:
-		BUG();
+		RB_WARN_ON(cpu_buffer, 1);
 	}
 
 	return NULL;
@@ -4140,7 +4581,7 @@
  * not consume the data.
  */
 struct ring_buffer_event *
-ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts,
 		 unsigned long *lost_events)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
@@ -4166,6 +4607,20 @@
 	return event;
 }
 
+/** ring_buffer_iter_dropped - report if there are dropped events
+ * @iter: The ring buffer iterator
+ *
+ * Returns true if there was dropped events since the last peek.
+ */
+bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter)
+{
+	bool ret = iter->missed_events != 0;
+
+	iter->missed_events = 0;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ring_buffer_iter_dropped);
+
 /**
  * ring_buffer_iter_peek - peek at the next event to be read
  * @iter: The ring buffer iterator
@@ -4204,7 +4659,7 @@
  * and eventually empty the ring buffer if the producer is slower.
  */
 struct ring_buffer_event *
-ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_consume(struct trace_buffer *buffer, int cpu, u64 *ts,
 		    unsigned long *lost_events)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -4264,7 +4719,7 @@
  * This overall must be paired with ring_buffer_read_finish.
  */
 struct ring_buffer_iter *
-ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags)
+ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_iter *iter;
@@ -4272,16 +4727,21 @@
 	if (!cpumask_test_cpu(cpu, buffer->cpumask))
 		return NULL;
 
-	iter = kmalloc(sizeof(*iter), flags);
+	iter = kzalloc(sizeof(*iter), flags);
 	if (!iter)
 		return NULL;
 
+	iter->event = kmalloc(BUF_MAX_DATA_SIZE, flags);
+	if (!iter->event) {
+		kfree(iter);
+		return NULL;
+	}
+
 	cpu_buffer = buffer->buffers[cpu];
 
 	iter->cpu_buffer = cpu_buffer;
 
-	atomic_inc(&buffer->resize_disabled);
-	atomic_inc(&cpu_buffer->record_disabled);
+	atomic_inc(&cpu_buffer->resize_disabled);
 
 	return iter;
 }
@@ -4354,48 +4814,38 @@
 	rb_check_pages(cpu_buffer);
 	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 
-	atomic_dec(&cpu_buffer->record_disabled);
-	atomic_dec(&cpu_buffer->buffer->resize_disabled);
+	atomic_dec(&cpu_buffer->resize_disabled);
+	kfree(iter->event);
 	kfree(iter);
 }
 EXPORT_SYMBOL_GPL(ring_buffer_read_finish);
 
 /**
- * ring_buffer_read - read the next item in the ring buffer by the iterator
+ * ring_buffer_iter_advance - advance the iterator to the next location
  * @iter: The ring buffer iterator
- * @ts: The time stamp of the event read.
  *
- * This reads the next event in the ring buffer and increments the iterator.
+ * Move the location of the iterator such that the next read will
+ * be the next location of the iterator.
  */
-struct ring_buffer_event *
-ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
+void ring_buffer_iter_advance(struct ring_buffer_iter *iter)
 {
-	struct ring_buffer_event *event;
 	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
- again:
-	event = rb_iter_peek(iter, ts);
-	if (!event)
-		goto out;
-
-	if (event->type_len == RINGBUF_TYPE_PADDING)
-		goto again;
 
 	rb_advance_iter(iter);
- out:
-	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 
-	return event;
+	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 }
-EXPORT_SYMBOL_GPL(ring_buffer_read);
+EXPORT_SYMBOL_GPL(ring_buffer_iter_advance);
 
 /**
  * ring_buffer_size - return the size of the ring buffer (in bytes)
  * @buffer: The ring buffer.
+ * @cpu: The CPU to get ring buffer size from.
  */
-unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu)
 {
 	/*
 	 * Earlier, this method returned
@@ -4447,8 +4897,8 @@
 	cpu_buffer->read = 0;
 	cpu_buffer->read_bytes = 0;
 
-	cpu_buffer->write_stamp = 0;
-	cpu_buffer->read_stamp = 0;
+	rb_time_set(&cpu_buffer->write_stamp, 0);
+	rb_time_set(&cpu_buffer->before_stamp, 0);
 
 	cpu_buffer->lost_events = 0;
 	cpu_buffer->last_overrun = 0;
@@ -4456,27 +4906,11 @@
 	rb_head_page_activate(cpu_buffer);
 }
 
-/**
- * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
- * @buffer: The ring buffer to reset a per cpu buffer of
- * @cpu: The CPU buffer to be reset
- */
-void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
+/* Must have disabled the cpu buffer then done a synchronize_rcu */
+static void reset_disabled_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
 	unsigned long flags;
 
-	if (!cpumask_test_cpu(cpu, buffer->cpumask))
-		return;
-	/* prevent another thread from changing buffer sizes */
-	mutex_lock(&buffer->mutex);
-
-	atomic_inc(&buffer->resize_disabled);
-	atomic_inc(&cpu_buffer->record_disabled);
-
-	/* Make sure all commits have finished */
-	synchronize_rcu();
-
 	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
 
 	if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
@@ -4490,24 +4924,105 @@
 
  out:
 	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+}
+
+/**
+ * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
+ * @buffer: The ring buffer to reset a per cpu buffer of
+ * @cpu: The CPU buffer to be reset
+ */
+void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+
+	if (!cpumask_test_cpu(cpu, buffer->cpumask))
+		return;
+
+	/* prevent another thread from changing buffer sizes */
+	mutex_lock(&buffer->mutex);
+
+	atomic_inc(&cpu_buffer->resize_disabled);
+	atomic_inc(&cpu_buffer->record_disabled);
+
+	/* Make sure all commits have finished */
+	synchronize_rcu();
+
+	reset_disabled_cpu_buffer(cpu_buffer);
 
 	atomic_dec(&cpu_buffer->record_disabled);
-	atomic_dec(&buffer->resize_disabled);
+	atomic_dec(&cpu_buffer->resize_disabled);
 
 	mutex_unlock(&buffer->mutex);
 }
 EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
 
 /**
+ * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
+ * @buffer: The ring buffer to reset a per cpu buffer of
+ * @cpu: The CPU buffer to be reset
+ */
+void ring_buffer_reset_online_cpus(struct trace_buffer *buffer)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	int cpu;
+
+	/* prevent another thread from changing buffer sizes */
+	mutex_lock(&buffer->mutex);
+
+	for_each_online_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+
+		atomic_inc(&cpu_buffer->resize_disabled);
+		atomic_inc(&cpu_buffer->record_disabled);
+	}
+
+	/* Make sure all commits have finished */
+	synchronize_rcu();
+
+	for_each_online_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+
+		reset_disabled_cpu_buffer(cpu_buffer);
+
+		atomic_dec(&cpu_buffer->record_disabled);
+		atomic_dec(&cpu_buffer->resize_disabled);
+	}
+
+	mutex_unlock(&buffer->mutex);
+}
+
+/**
  * ring_buffer_reset - reset a ring buffer
  * @buffer: The ring buffer to reset all cpu buffers
  */
-void ring_buffer_reset(struct ring_buffer *buffer)
+void ring_buffer_reset(struct trace_buffer *buffer)
 {
+	struct ring_buffer_per_cpu *cpu_buffer;
 	int cpu;
 
-	for_each_buffer_cpu(buffer, cpu)
-		ring_buffer_reset_cpu(buffer, cpu);
+	/* prevent another thread from changing buffer sizes */
+	mutex_lock(&buffer->mutex);
+
+	for_each_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+
+		atomic_inc(&cpu_buffer->resize_disabled);
+		atomic_inc(&cpu_buffer->record_disabled);
+	}
+
+	/* Make sure all commits have finished */
+	synchronize_rcu();
+
+	for_each_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+
+		reset_disabled_cpu_buffer(cpu_buffer);
+
+		atomic_dec(&cpu_buffer->record_disabled);
+		atomic_dec(&cpu_buffer->resize_disabled);
+	}
+
+	mutex_unlock(&buffer->mutex);
 }
 EXPORT_SYMBOL_GPL(ring_buffer_reset);
 
@@ -4515,7 +5030,7 @@
  * rind_buffer_empty - is the ring buffer empty?
  * @buffer: The ring buffer to test
  */
-bool ring_buffer_empty(struct ring_buffer *buffer)
+bool ring_buffer_empty(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long flags;
@@ -4545,7 +5060,7 @@
  * @buffer: The ring buffer
  * @cpu: The CPU buffer to test
  */
-bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
+bool ring_buffer_empty_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long flags;
@@ -4571,14 +5086,15 @@
  * ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers
  * @buffer_a: One buffer to swap with
  * @buffer_b: The other buffer to swap with
+ * @cpu: the CPU of the buffers to swap
  *
  * This function is useful for tracers that want to take a "snapshot"
  * of a CPU buffer and has another back up buffer lying around.
  * it is expected that the tracer handles the cpu buffer not being
  * used at the moment.
  */
-int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
-			 struct ring_buffer *buffer_b, int cpu)
+int ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
+			 struct trace_buffer *buffer_b, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer_a;
 	struct ring_buffer_per_cpu *cpu_buffer_b;
@@ -4657,7 +5173,7 @@
  * Returns:
  *  The page allocated, or ERR_PTR
  */
-void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu)
+void *ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_data_page *bpage = NULL;
@@ -4704,7 +5220,7 @@
  *
  * Free a page allocated from ring_buffer_alloc_read_page.
  */
-void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
+void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
 	struct buffer_data_page *bpage = data;
@@ -4764,7 +5280,7 @@
  *  >=0 if data has been transferred, returns the offset of consumed data.
  *  <0 if no data has been transferred.
  */
-int ring_buffer_read_page(struct ring_buffer *buffer,
+int ring_buffer_read_page(struct trace_buffer *buffer,
 			  void **data_page, size_t len, int cpu, int full)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
@@ -4935,12 +5451,12 @@
  */
 int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	long nr_pages_same;
 	int cpu_i;
 	unsigned long nr_pages;
 
-	buffer = container_of(node, struct ring_buffer, node);
+	buffer = container_of(node, struct trace_buffer, node);
 	if (cpumask_test_cpu(cpu, buffer->cpumask))
 		return 0;
 
@@ -4990,7 +5506,7 @@
 static struct task_struct *rb_threads[NR_CPUS] __initdata;
 
 struct rb_test_data {
-	struct ring_buffer	*buffer;
+	struct trace_buffer *buffer;
 	unsigned long		events;
 	unsigned long		bytes_written;
 	unsigned long		bytes_alloc;
@@ -5132,12 +5648,12 @@
 static __init int test_ringbuffer(void)
 {
 	struct task_struct *rb_hammer;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	int cpu;
 	int ret = 0;
 
 	if (security_locked_down(LOCKDOWN_TRACEFS)) {
-		pr_warning("Lockdown is enabled, skipping ring buffer tests\n");
+		pr_warn("Lockdown is enabled, skipping ring buffer tests\n");
 		return 0;
 	}
 
diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index 09b0b49..78e5765 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -29,7 +29,7 @@
 static DECLARE_COMPLETION(read_start);
 static DECLARE_COMPLETION(read_done);
 
-static struct ring_buffer *buffer;
+static struct trace_buffer *buffer;
 static struct task_struct *producer;
 static struct task_struct *consumer;
 static unsigned long read;
@@ -45,8 +45,8 @@
 static int producer_nice = MAX_NICE;
 static int consumer_nice = MAX_NICE;
 
-static int producer_fifo = -1;
-static int consumer_fifo = -1;
+static int producer_fifo;
+static int consumer_fifo;
 
 module_param(producer_nice, int, 0644);
 MODULE_PARM_DESC(producer_nice, "nice prio for producer");
@@ -55,10 +55,10 @@
 MODULE_PARM_DESC(consumer_nice, "nice prio for consumer");
 
 module_param(producer_fifo, int, 0644);
-MODULE_PARM_DESC(producer_fifo, "fifo prio for producer");
+MODULE_PARM_DESC(producer_fifo, "use fifo for producer: 0 - disabled, 1 - low prio, 2 - fifo");
 
 module_param(consumer_fifo, int, 0644);
-MODULE_PARM_DESC(consumer_fifo, "fifo prio for consumer");
+MODULE_PARM_DESC(consumer_fifo, "use fifo for consumer: 0 - disabled, 1 - low prio, 2 - fifo");
 
 static int read_events;
 
@@ -269,10 +269,10 @@
 
 #ifndef CONFIG_PREEMPTION
 		/*
-		 * If we are a non preempt kernel, the 10 second run will
+		 * If we are a non preempt kernel, the 10 seconds run will
 		 * stop everything while it runs. Instead, we will call
 		 * cond_resched and also add any time that was lost by a
-		 * rescedule.
+		 * reschedule.
 		 *
 		 * Do a cond resched at the same frequency we would wake up
 		 * the reader.
@@ -303,22 +303,22 @@
 		trace_printk("ERROR!\n");
 
 	if (!disable_reader) {
-		if (consumer_fifo < 0)
+		if (consumer_fifo)
+			trace_printk("Running Consumer at SCHED_FIFO %s\n",
+				     consumer_fifo == 1 ? "low" : "high");
+		else
 			trace_printk("Running Consumer at nice: %d\n",
 				     consumer_nice);
-		else
-			trace_printk("Running Consumer at SCHED_FIFO %d\n",
-				     consumer_fifo);
 	}
-	if (producer_fifo < 0)
+	if (producer_fifo)
+		trace_printk("Running Producer at SCHED_FIFO %s\n",
+			     producer_fifo == 1 ? "low" : "high");
+	else
 		trace_printk("Running Producer at nice: %d\n",
 			     producer_nice);
-	else
-		trace_printk("Running Producer at SCHED_FIFO %d\n",
-			     producer_fifo);
 
 	/* Let the user know that the test is running at low priority */
-	if (producer_fifo < 0 && consumer_fifo < 0 &&
+	if (!producer_fifo && !consumer_fifo &&
 	    producer_nice == MAX_NICE && consumer_nice == MAX_NICE)
 		trace_printk("WARNING!!! This test is running at lowest priority.\n");
 
@@ -455,21 +455,19 @@
 	 * Run them as low-prio background tasks by default:
 	 */
 	if (!disable_reader) {
-		if (consumer_fifo >= 0) {
-			struct sched_param param = {
-				.sched_priority = consumer_fifo
-			};
-			sched_setscheduler(consumer, SCHED_FIFO, &param);
-		} else
+		if (consumer_fifo >= 2)
+			sched_set_fifo(consumer);
+		else if (consumer_fifo == 1)
+			sched_set_fifo_low(consumer);
+		else
 			set_user_nice(consumer, consumer_nice);
 	}
 
-	if (producer_fifo >= 0) {
-		struct sched_param param = {
-			.sched_priority = producer_fifo
-		};
-		sched_setscheduler(producer, SCHED_FIFO, &param);
-	} else
+	if (producer_fifo >= 2)
+		sched_set_fifo(producer);
+	else if (producer_fifo == 1)
+		sched_set_fifo_low(producer);
+	else
 		set_user_nice(producer, producer_nice);
 
 	return 0;
diff --git a/kernel/trace/synth_event_gen_test.c b/kernel/trace/synth_event_gen_test.c
new file mode 100644
index 0000000..edd912c
--- /dev/null
+++ b/kernel/trace/synth_event_gen_test.c
@@ -0,0 +1,529 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test module for in-kernel sythetic event creation and generation.
+ *
+ * Copyright (C) 2019 Tom Zanussi <zanussi@kernel.org>
+ */
+
+#include <linux/module.h>
+#include <linux/trace_events.h>
+
+/*
+ * This module is a simple test of basic functionality for in-kernel
+ * synthetic event creation and generation, the first and second tests
+ * using synth_event_gen_cmd_start() and synth_event_add_field(), the
+ * third uses synth_event_create() to do it all at once with a static
+ * field array.
+ *
+ * Following that are a few examples using the created events to test
+ * various ways of tracing a synthetic event.
+ *
+ * To test, select CONFIG_SYNTH_EVENT_GEN_TEST and build the module.
+ * Then:
+ *
+ * # insmod kernel/trace/synth_event_gen_test.ko
+ * # cat /sys/kernel/debug/tracing/trace
+ *
+ * You should see several events in the trace buffer -
+ * "create_synth_test", "empty_synth_test", and several instances of
+ * "gen_synth_test".
+ *
+ * To remove the events, remove the module:
+ *
+ * # rmmod synth_event_gen_test
+ *
+ */
+
+static struct trace_event_file *create_synth_test;
+static struct trace_event_file *empty_synth_test;
+static struct trace_event_file *gen_synth_test;
+
+/*
+ * Test to make sure we can create a synthetic event, then add more
+ * fields.
+ */
+static int __init test_gen_synth_cmd(void)
+{
+	struct dynevent_cmd cmd;
+	u64 vals[7];
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Create the empty gen_synth_test synthetic event with the
+	 * first 4 fields.
+	 */
+	ret = synth_event_gen_cmd_start(&cmd, "gen_synth_test", THIS_MODULE,
+					"pid_t", "next_pid_field",
+					"char[16]", "next_comm_field",
+					"u64", "ts_ns",
+					"u64", "ts_ms");
+	if (ret)
+		goto free;
+
+	/* Use synth_event_add_field to add the rest of the fields */
+
+	ret = synth_event_add_field(&cmd, "unsigned int", "cpu");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "char[64]", "my_string_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "int", "my_int_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the gen_synth_test event file.  We need to prevent
+	 * the instance and event from disappearing from underneath
+	 * us, which trace_get_event_file() does (though in this case
+	 * we're using the top-level instance which never goes away).
+	 */
+	gen_synth_test = trace_get_event_file(NULL, "synthetic",
+					      "gen_synth_test");
+	if (IS_ERR(gen_synth_test)) {
+		ret = PTR_ERR(gen_synth_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(gen_synth_test->tr,
+					"synthetic", "gen_synth_test", true);
+	if (ret) {
+		trace_put_event_file(gen_synth_test);
+		goto delete;
+	}
+
+	/* Create some bogus values just for testing */
+
+	vals[0] = 777;			/* next_pid_field */
+	vals[1] = (u64)(long)"hula hoops";	/* next_comm_field */
+	vals[2] = 1000000;		/* ts_ns */
+	vals[3] = 1000;			/* ts_ms */
+	vals[4] = raw_smp_processor_id(); /* cpu */
+	vals[5] = (u64)(long)"thneed";	/* my_string_field */
+	vals[6] = 598;			/* my_int_field */
+
+	/* Now generate a gen_synth_test event */
+	ret = synth_event_trace_array(gen_synth_test, vals, ARRAY_SIZE(vals));
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	synth_event_delete("gen_synth_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+/*
+ * Test to make sure we can create an initially empty synthetic event,
+ * then add all the fields.
+ */
+static int __init test_empty_synth_event(void)
+{
+	struct dynevent_cmd cmd;
+	u64 vals[7];
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Create the empty_synth_test synthetic event with no fields.
+	 */
+	ret = synth_event_gen_cmd_start(&cmd, "empty_synth_test", THIS_MODULE);
+	if (ret)
+		goto free;
+
+	/* Use synth_event_add_field to add all of the fields */
+
+	ret = synth_event_add_field(&cmd, "pid_t", "next_pid_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "char[16]", "next_comm_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "u64", "ts_ns");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "u64", "ts_ms");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "unsigned int", "cpu");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "char[64]", "my_string_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "int", "my_int_field");
+	if (ret)
+		goto free;
+
+	/* All fields have been added, close and register the synth event */
+
+	ret = synth_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the empty_synth_test event file.  We need to
+	 * prevent the instance and event from disappearing from
+	 * underneath us, which trace_get_event_file() does (though in
+	 * this case we're using the top-level instance which never
+	 * goes away).
+	 */
+	empty_synth_test = trace_get_event_file(NULL, "synthetic",
+						"empty_synth_test");
+	if (IS_ERR(empty_synth_test)) {
+		ret = PTR_ERR(empty_synth_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(empty_synth_test->tr,
+					"synthetic", "empty_synth_test", true);
+	if (ret) {
+		trace_put_event_file(empty_synth_test);
+		goto delete;
+	}
+
+	/* Create some bogus values just for testing */
+
+	vals[0] = 777;			/* next_pid_field */
+	vals[1] = (u64)(long)"tiddlywinks";	/* next_comm_field */
+	vals[2] = 1000000;		/* ts_ns */
+	vals[3] = 1000;			/* ts_ms */
+	vals[4] = raw_smp_processor_id(); /* cpu */
+	vals[5] = (u64)(long)"thneed_2.0";	/* my_string_field */
+	vals[6] = 399;			/* my_int_field */
+
+	/* Now trace an empty_synth_test event */
+	ret = synth_event_trace_array(empty_synth_test, vals, ARRAY_SIZE(vals));
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	synth_event_delete("empty_synth_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+static struct synth_field_desc create_synth_test_fields[] = {
+	{ .type = "pid_t",		.name = "next_pid_field" },
+	{ .type = "char[16]",		.name = "next_comm_field" },
+	{ .type = "u64",		.name = "ts_ns" },
+	{ .type = "char[]",		.name = "dynstring_field_1" },
+	{ .type = "u64",		.name = "ts_ms" },
+	{ .type = "unsigned int",	.name = "cpu" },
+	{ .type = "char[64]",		.name = "my_string_field" },
+	{ .type = "char[]",		.name = "dynstring_field_2" },
+	{ .type = "int",		.name = "my_int_field" },
+};
+
+/*
+ * Test synthetic event creation all at once from array of field
+ * descriptors.
+ */
+static int __init test_create_synth_event(void)
+{
+	u64 vals[9];
+	int ret;
+
+	/* Create the create_synth_test event with the fields above */
+	ret = synth_event_create("create_synth_test",
+				 create_synth_test_fields,
+				 ARRAY_SIZE(create_synth_test_fields),
+				 THIS_MODULE);
+	if (ret)
+		goto out;
+
+	/*
+	 * Now get the create_synth_test event file.  We need to
+	 * prevent the instance and event from disappearing from
+	 * underneath us, which trace_get_event_file() does (though in
+	 * this case we're using the top-level instance which never
+	 * goes away).
+	 */
+	create_synth_test = trace_get_event_file(NULL, "synthetic",
+						 "create_synth_test");
+	if (IS_ERR(create_synth_test)) {
+		ret = PTR_ERR(create_synth_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(create_synth_test->tr,
+					"synthetic", "create_synth_test", true);
+	if (ret) {
+		trace_put_event_file(create_synth_test);
+		goto delete;
+	}
+
+	/* Create some bogus values just for testing */
+
+	vals[0] = 777;			/* next_pid_field */
+	vals[1] = (u64)(long)"tiddlywinks";	/* next_comm_field */
+	vals[2] = 1000000;		/* ts_ns */
+	vals[3] = (u64)(long)"xrayspecs";	/* dynstring_field_1 */
+	vals[4] = 1000;			/* ts_ms */
+	vals[5] = raw_smp_processor_id(); /* cpu */
+	vals[6] = (u64)(long)"thneed";	/* my_string_field */
+	vals[7] = (u64)(long)"kerplunk";	/* dynstring_field_2 */
+	vals[8] = 398;			/* my_int_field */
+
+	/* Now generate a create_synth_test event */
+	ret = synth_event_trace_array(create_synth_test, vals, ARRAY_SIZE(vals));
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	ret = synth_event_delete("create_synth_test");
+
+	goto out;
+}
+
+/*
+ * Test tracing a synthetic event by reserving trace buffer space,
+ * then filling in fields one after another.
+ */
+static int __init test_add_next_synth_val(void)
+{
+	struct synth_event_trace_state trace_state;
+	int ret;
+
+	/* Start by reserving space in the trace buffer */
+	ret = synth_event_trace_start(gen_synth_test, &trace_state);
+	if (ret)
+		return ret;
+
+	/* Write some bogus values into the trace buffer, one after another */
+
+	/* next_pid_field */
+	ret = synth_event_add_next_val(777, &trace_state);
+	if (ret)
+		goto out;
+
+	/* next_comm_field */
+	ret = synth_event_add_next_val((u64)(long)"slinky", &trace_state);
+	if (ret)
+		goto out;
+
+	/* ts_ns */
+	ret = synth_event_add_next_val(1000000, &trace_state);
+	if (ret)
+		goto out;
+
+	/* ts_ms */
+	ret = synth_event_add_next_val(1000, &trace_state);
+	if (ret)
+		goto out;
+
+	/* cpu */
+	ret = synth_event_add_next_val(raw_smp_processor_id(), &trace_state);
+	if (ret)
+		goto out;
+
+	/* my_string_field */
+	ret = synth_event_add_next_val((u64)(long)"thneed_2.01", &trace_state);
+	if (ret)
+		goto out;
+
+	/* my_int_field */
+	ret = synth_event_add_next_val(395, &trace_state);
+ out:
+	/* Finally, commit the event */
+	ret = synth_event_trace_end(&trace_state);
+
+	return ret;
+}
+
+/*
+ * Test tracing a synthetic event by reserving trace buffer space,
+ * then filling in fields using field names, which can be done in any
+ * order.
+ */
+static int __init test_add_synth_val(void)
+{
+	struct synth_event_trace_state trace_state;
+	int ret;
+
+	/* Start by reserving space in the trace buffer */
+	ret = synth_event_trace_start(gen_synth_test, &trace_state);
+	if (ret)
+		return ret;
+
+	/* Write some bogus values into the trace buffer, using field names */
+
+	ret = synth_event_add_val("ts_ns", 1000000, &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("ts_ms", 1000, &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("cpu", raw_smp_processor_id(), &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("next_pid_field", 777, &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("next_comm_field", (u64)(long)"silly putty",
+				  &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("my_string_field", (u64)(long)"thneed_9",
+				  &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("my_int_field", 3999, &trace_state);
+ out:
+	/* Finally, commit the event */
+	ret = synth_event_trace_end(&trace_state);
+
+	return ret;
+}
+
+/*
+ * Test tracing a synthetic event all at once from array of values.
+ */
+static int __init test_trace_synth_event(void)
+{
+	int ret;
+
+	/* Trace some bogus values just for testing */
+	ret = synth_event_trace(create_synth_test, 9,	/* number of values */
+				(u64)444,		/* next_pid_field */
+				(u64)(long)"clackers",	/* next_comm_field */
+				(u64)1000000,		/* ts_ns */
+				(u64)(long)"viewmaster",/* dynstring_field_1 */
+				(u64)1000,		/* ts_ms */
+				(u64)raw_smp_processor_id(), /* cpu */
+				(u64)(long)"Thneed",	/* my_string_field */
+				(u64)(long)"yoyos",	/* dynstring_field_2 */
+				(u64)999);		/* my_int_field */
+	return ret;
+}
+
+static int __init synth_event_gen_test_init(void)
+{
+	int ret;
+
+	ret = test_gen_synth_cmd();
+	if (ret)
+		return ret;
+
+	ret = test_empty_synth_event();
+	if (ret) {
+		WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
+						  "synthetic",
+						  "gen_synth_test", false));
+		trace_put_event_file(gen_synth_test);
+		WARN_ON(synth_event_delete("gen_synth_test"));
+		goto out;
+	}
+
+	ret = test_create_synth_event();
+	if (ret) {
+		WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
+						  "synthetic",
+						  "gen_synth_test", false));
+		trace_put_event_file(gen_synth_test);
+		WARN_ON(synth_event_delete("gen_synth_test"));
+
+		WARN_ON(trace_array_set_clr_event(empty_synth_test->tr,
+						  "synthetic",
+						  "empty_synth_test", false));
+		trace_put_event_file(empty_synth_test);
+		WARN_ON(synth_event_delete("empty_synth_test"));
+		goto out;
+	}
+
+	ret = test_add_next_synth_val();
+	WARN_ON(ret);
+
+	ret = test_add_synth_val();
+	WARN_ON(ret);
+
+	ret = test_trace_synth_event();
+	WARN_ON(ret);
+ out:
+	return ret;
+}
+
+static void __exit synth_event_gen_test_exit(void)
+{
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
+					  "synthetic",
+					  "gen_synth_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(gen_synth_test);
+
+	/* Now unregister and free the synthetic event */
+	WARN_ON(synth_event_delete("gen_synth_test"));
+
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(empty_synth_test->tr,
+					  "synthetic",
+					  "empty_synth_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(empty_synth_test);
+
+	/* Now unregister and free the synthetic event */
+	WARN_ON(synth_event_delete("empty_synth_test"));
+
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(create_synth_test->tr,
+					  "synthetic",
+					  "create_synth_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(create_synth_test);
+
+	/* Now unregister and free the synthetic event */
+	WARN_ON(synth_event_delete("create_synth_test"));
+}
+
+module_init(synth_event_gen_test_init)
+module_exit(synth_event_gen_test_exit)
+
+MODULE_AUTHOR("Tom Zanussi");
+MODULE_DESCRIPTION("synthetic event generation test");
+MODULE_LICENSE("GPL v2");
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5240ba9..953dd95 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -45,6 +45,9 @@
 #include <linux/trace.h>
 #include <linux/sched/clock.h>
 #include <linux/sched/rt.h>
+#include <linux/fsnotify.h>
+#include <linux/irq_work.h>
+#include <linux/workqueue.h>
 
 #include "trace.h"
 #include "trace_output.h"
@@ -65,10 +68,21 @@
 static bool __read_mostly tracing_selftest_running;
 
 /*
- * If a tracer is running, we do not want to run SELFTEST.
+ * If boot-time tracing including tracers/events via kernel cmdline
+ * is running, we do not want to run SELFTEST.
  */
 bool __read_mostly tracing_selftest_disabled;
 
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+void __init disable_tracing_selftest(const char *reason)
+{
+	if (!tracing_selftest_disabled) {
+		tracing_selftest_disabled = true;
+		pr_info("Ftrace startup test is disabled due to %s\n", reason);
+	}
+}
+#endif
+
 /* Pipe tracepoints to printk */
 struct trace_iterator *tracepoint_print_iter;
 int tracepoint_printk;
@@ -159,9 +173,9 @@
 static union trace_eval_map_item *trace_eval_maps;
 #endif /* CONFIG_TRACE_EVAL_MAP_FILE */
 
-static int tracing_set_tracer(struct trace_array *tr, const char *buf);
+int tracing_set_tracer(struct trace_array *tr, const char *buf);
 static void ftrace_trace_userstack(struct trace_array *tr,
-				   struct ring_buffer *buffer,
+				   struct trace_buffer *buffer,
 				   unsigned long flags, int pc);
 
 #define MAX_TRACER_SIZE		100
@@ -219,7 +233,7 @@
 static int __init set_trace_boot_options(char *str)
 {
 	strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
-	return 0;
+	return 1;
 }
 __setup("trace_options=", set_trace_boot_options);
 
@@ -230,12 +244,16 @@
 {
 	strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
 	trace_boot_clock = trace_boot_clock_buf;
-	return 0;
+	return 1;
 }
 __setup("trace_clock=", set_trace_boot_clock);
 
 static int __init set_tracepoint_printk(char *str)
 {
+	/* Ignore the "tp_printk_stop_on_boot" param */
+	if (*str == '_')
+		return 0;
+
 	if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
 		tracepoint_printk = 1;
 	return 1;
@@ -249,6 +267,145 @@
 	return nsec;
 }
 
+static void
+trace_process_export(struct trace_export *export,
+	       struct ring_buffer_event *event, int flag)
+{
+	struct trace_entry *entry;
+	unsigned int size = 0;
+
+	if (export->flags & flag) {
+		entry = ring_buffer_event_data(event);
+		size = ring_buffer_event_length(event);
+		export->write(export, entry, size);
+	}
+}
+
+static DEFINE_MUTEX(ftrace_export_lock);
+
+static struct trace_export __rcu *ftrace_exports_list __read_mostly;
+
+static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_event_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_marker_exports_enabled);
+
+static inline void ftrace_exports_enable(struct trace_export *export)
+{
+	if (export->flags & TRACE_EXPORT_FUNCTION)
+		static_branch_inc(&trace_function_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_EVENT)
+		static_branch_inc(&trace_event_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_MARKER)
+		static_branch_inc(&trace_marker_exports_enabled);
+}
+
+static inline void ftrace_exports_disable(struct trace_export *export)
+{
+	if (export->flags & TRACE_EXPORT_FUNCTION)
+		static_branch_dec(&trace_function_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_EVENT)
+		static_branch_dec(&trace_event_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_MARKER)
+		static_branch_dec(&trace_marker_exports_enabled);
+}
+
+static void ftrace_exports(struct ring_buffer_event *event, int flag)
+{
+	struct trace_export *export;
+
+	preempt_disable_notrace();
+
+	export = rcu_dereference_raw_check(ftrace_exports_list);
+	while (export) {
+		trace_process_export(export, event, flag);
+		export = rcu_dereference_raw_check(export->next);
+	}
+
+	preempt_enable_notrace();
+}
+
+static inline void
+add_trace_export(struct trace_export **list, struct trace_export *export)
+{
+	rcu_assign_pointer(export->next, *list);
+	/*
+	 * We are entering export into the list but another
+	 * CPU might be walking that list. We need to make sure
+	 * the export->next pointer is valid before another CPU sees
+	 * the export pointer included into the list.
+	 */
+	rcu_assign_pointer(*list, export);
+}
+
+static inline int
+rm_trace_export(struct trace_export **list, struct trace_export *export)
+{
+	struct trace_export **p;
+
+	for (p = list; *p != NULL; p = &(*p)->next)
+		if (*p == export)
+			break;
+
+	if (*p != export)
+		return -1;
+
+	rcu_assign_pointer(*p, (*p)->next);
+
+	return 0;
+}
+
+static inline void
+add_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+	ftrace_exports_enable(export);
+
+	add_trace_export(list, export);
+}
+
+static inline int
+rm_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+	int ret;
+
+	ret = rm_trace_export(list, export);
+	ftrace_exports_disable(export);
+
+	return ret;
+}
+
+int register_ftrace_export(struct trace_export *export)
+{
+	if (WARN_ON_ONCE(!export->write))
+		return -1;
+
+	mutex_lock(&ftrace_export_lock);
+
+	add_ftrace_export(&ftrace_exports_list, export);
+
+	mutex_unlock(&ftrace_export_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_export);
+
+int unregister_ftrace_export(struct trace_export *export)
+{
+	int ret;
+
+	mutex_lock(&ftrace_export_lock);
+
+	ret = rm_ftrace_export(&ftrace_exports_list, export);
+
+	mutex_unlock(&ftrace_export_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_export);
+
 /* trace_flags holds trace_options default values */
 #define TRACE_DEFAULT_FLAGS						\
 	(FUNCTION_DEFAULT_FLAGS |					\
@@ -299,12 +456,24 @@
 	this_tr->ref--;
 }
 
+/**
+ * trace_array_put - Decrement the reference counter for this trace array.
+ *
+ * NOTE: Use this when we no longer need the trace array returned by
+ * trace_array_get_by_name(). This ensures the trace array can be later
+ * destroyed.
+ *
+ */
 void trace_array_put(struct trace_array *this_tr)
 {
+	if (!this_tr)
+		return;
+
 	mutex_lock(&trace_types_lock);
 	__trace_array_put(this_tr);
 	mutex_unlock(&trace_types_lock);
 }
+EXPORT_SYMBOL_GPL(trace_array_put);
 
 int tracing_check_open_get_tr(struct trace_array *tr)
 {
@@ -324,7 +493,7 @@
 }
 
 int call_filter_check_discard(struct trace_event_call *call, void *rec,
-			      struct ring_buffer *buffer,
+			      struct trace_buffer *buffer,
 			      struct ring_buffer_event *event)
 {
 	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
@@ -372,16 +541,22 @@
  * Returns false if @task should be traced.
  */
 bool
-trace_ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)
+trace_ignore_this_task(struct trace_pid_list *filtered_pids,
+		       struct trace_pid_list *filtered_no_pids,
+		       struct task_struct *task)
 {
 	/*
-	 * Return false, because if filtered_pids does not exist,
-	 * all pids are good to trace.
+	 * If filterd_no_pids is not empty, and the task's pid is listed
+	 * in filtered_no_pids, then return true.
+	 * Otherwise, if filtered_pids is empty, that means we can
+	 * trace all tasks. If it has content, then only trace pids
+	 * within filtered_pids.
 	 */
-	if (!filtered_pids)
-		return false;
 
-	return !trace_find_filtered_pid(filtered_pids, task->pid);
+	return (filtered_pids &&
+		!trace_find_filtered_pid(filtered_pids, task->pid)) ||
+		(filtered_no_pids &&
+		 trace_find_filtered_pid(filtered_no_pids, task->pid));
 }
 
 /**
@@ -589,7 +764,7 @@
 	return read;
 }
 
-static u64 buffer_ftrace_now(struct trace_buffer *buf, int cpu)
+static u64 buffer_ftrace_now(struct array_buffer *buf, int cpu)
 {
 	u64 ts;
 
@@ -605,7 +780,7 @@
 
 u64 ftrace_now(int cpu)
 {
-	return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
+	return buffer_ftrace_now(&global_trace.array_buffer, cpu);
 }
 
 /**
@@ -733,22 +908,22 @@
 #endif
 
 #ifdef CONFIG_STACKTRACE
-static void __ftrace_trace_stack(struct ring_buffer *buffer,
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
 				 unsigned long flags,
 				 int skip, int pc, struct pt_regs *regs);
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs);
 
 #else
-static inline void __ftrace_trace_stack(struct ring_buffer *buffer,
+static inline void __ftrace_trace_stack(struct trace_buffer *buffer,
 					unsigned long flags,
 					int skip, int pc, struct pt_regs *regs)
 {
 }
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs)
 {
@@ -766,7 +941,7 @@
 }
 
 static __always_inline struct ring_buffer_event *
-__trace_buffer_lock_reserve(struct ring_buffer *buffer,
+__trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags, int pc)
@@ -782,8 +957,8 @@
 
 void tracer_tracing_on(struct trace_array *tr)
 {
-	if (tr->trace_buffer.buffer)
-		ring_buffer_record_on(tr->trace_buffer.buffer);
+	if (tr->array_buffer.buffer)
+		ring_buffer_record_on(tr->array_buffer.buffer);
 	/*
 	 * This flag is looked at when buffers haven't been allocated
 	 * yet, or by some tracers (like irqsoff), that just want to
@@ -811,7 +986,7 @@
 
 
 static __always_inline void
-__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
+__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
 {
 	__this_cpu_write(trace_taskinfo_save, true);
 
@@ -834,7 +1009,7 @@
 int __trace_puts(unsigned long ip, const char *str, int size)
 {
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	int alloc;
@@ -851,11 +1026,14 @@
 	alloc = sizeof(*entry) + size + 2; /* possible \n added */
 
 	local_save_flags(irq_flags);
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, 
 					    irq_flags, pc);
-	if (!event)
-		return 0;
+	if (!event) {
+		size = 0;
+		goto out;
+	}
 
 	entry = ring_buffer_event_data(event);
 	entry->ip = ip;
@@ -871,7 +1049,8 @@
 
 	__buffer_unlock_commit(buffer, event);
 	ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL);
-
+ out:
+	ring_buffer_nest_end(buffer);
 	return size;
 }
 EXPORT_SYMBOL_GPL(__trace_puts);
@@ -884,10 +1063,11 @@
 int __trace_bputs(unsigned long ip, const char *str)
 {
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct bputs_entry *entry;
 	unsigned long irq_flags;
 	int size = sizeof(struct bputs_entry);
+	int ret = 0;
 	int pc;
 
 	if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
@@ -899,11 +1079,13 @@
 		return 0;
 
 	local_save_flags(irq_flags);
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
+
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
 					    irq_flags, pc);
 	if (!event)
-		return 0;
+		goto out;
 
 	entry = ring_buffer_event_data(event);
 	entry->ip			= ip;
@@ -912,12 +1094,16 @@
 	__buffer_unlock_commit(buffer, event);
 	ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL);
 
-	return 1;
+	ret = 1;
+ out:
+	ring_buffer_nest_end(buffer);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(__trace_bputs);
 
 #ifdef CONFIG_TRACER_SNAPSHOT
-void tracing_snapshot_instance_cond(struct trace_array *tr, void *cond_data)
+static void tracing_snapshot_instance_cond(struct trace_array *tr,
+					   void *cond_data)
 {
 	struct tracer *tracer = tr->current_trace;
 	unsigned long flags;
@@ -1022,9 +1208,9 @@
 }
 EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data);
 
-static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
-					struct trace_buffer *size_buf, int cpu_id);
-static void set_buffer_entries(struct trace_buffer *buf, unsigned long val);
+static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
+					struct array_buffer *size_buf, int cpu_id);
+static void set_buffer_entries(struct array_buffer *buf, unsigned long val);
 
 int tracing_alloc_snapshot_instance(struct trace_array *tr)
 {
@@ -1034,7 +1220,7 @@
 
 		/* allocate spare buffer */
 		ret = resize_buffer_duplicate_size(&tr->max_buffer,
-				   &tr->trace_buffer, RING_BUFFER_ALL_CPUS);
+				   &tr->array_buffer, RING_BUFFER_ALL_CPUS);
 		if (ret < 0)
 			return ret;
 
@@ -1237,8 +1423,8 @@
 
 void tracer_tracing_off(struct trace_array *tr)
 {
-	if (tr->trace_buffer.buffer)
-		ring_buffer_record_off(tr->trace_buffer.buffer);
+	if (tr->array_buffer.buffer)
+		ring_buffer_record_off(tr->array_buffer.buffer);
 	/*
 	 * This flag is looked at when buffers haven't been allocated
 	 * yet, or by some tracers (like irqsoff), that just want to
@@ -1268,8 +1454,11 @@
 
 void disable_trace_on_warning(void)
 {
-	if (__disable_trace_on_warning)
+	if (__disable_trace_on_warning) {
+		trace_array_printk_buf(global_trace.array_buffer.buffer, _THIS_IP_,
+			"Disabling tracing due to warning\n");
 		tracing_off();
+	}
 }
 
 /**
@@ -1280,8 +1469,8 @@
  */
 bool tracer_tracing_is_on(struct trace_array *tr)
 {
-	if (tr->trace_buffer.buffer)
-		return ring_buffer_record_is_on(tr->trace_buffer.buffer);
+	if (tr->array_buffer.buffer)
+		return ring_buffer_record_is_on(tr->array_buffer.buffer);
 	return !tr->buffer_disabled;
 }
 
@@ -1301,10 +1490,12 @@
 	if (!str)
 		return 0;
 	buf_size = memparse(str, &str);
-	/* nr_entries can not be zero */
-	if (buf_size == 0)
-		return 0;
-	trace_buf_size = buf_size;
+	/*
+	 * nr_entries can not be zero and the startup
+	 * tests require some buffer space. Therefore
+	 * ensure we have at least 4096 bytes of buffer.
+	 */
+	trace_buf_size = max(4096UL, buf_size);
 	return 1;
 }
 __setup("trace_buf_size=", set_buf_size);
@@ -1498,6 +1689,73 @@
 }
 
 unsigned long __read_mostly	tracing_thresh;
+static const struct file_operations tracing_max_lat_fops;
+
+#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
+	defined(CONFIG_FSNOTIFY)
+
+static struct workqueue_struct *fsnotify_wq;
+
+static void latency_fsnotify_workfn(struct work_struct *work)
+{
+	struct trace_array *tr = container_of(work, struct trace_array,
+					      fsnotify_work);
+	fsnotify_inode(tr->d_max_latency->d_inode, FS_MODIFY);
+}
+
+static void latency_fsnotify_workfn_irq(struct irq_work *iwork)
+{
+	struct trace_array *tr = container_of(iwork, struct trace_array,
+					      fsnotify_irqwork);
+	queue_work(fsnotify_wq, &tr->fsnotify_work);
+}
+
+static void trace_create_maxlat_file(struct trace_array *tr,
+				     struct dentry *d_tracer)
+{
+	INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn);
+	init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq);
+	tr->d_max_latency = trace_create_file("tracing_max_latency", 0644,
+					      d_tracer, &tr->max_latency,
+					      &tracing_max_lat_fops);
+}
+
+__init static int latency_fsnotify_init(void)
+{
+	fsnotify_wq = alloc_workqueue("tr_max_lat_wq",
+				      WQ_UNBOUND | WQ_HIGHPRI, 0);
+	if (!fsnotify_wq) {
+		pr_err("Unable to allocate tr_max_lat_wq\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+late_initcall_sync(latency_fsnotify_init);
+
+void latency_fsnotify(struct trace_array *tr)
+{
+	if (!fsnotify_wq)
+		return;
+	/*
+	 * We cannot call queue_work(&tr->fsnotify_work) from here because it's
+	 * possible that we are called from __schedule() or do_idle(), which
+	 * could cause a deadlock.
+	 */
+	irq_work_queue(&tr->fsnotify_irqwork);
+}
+
+/*
+ * (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
+ *  defined(CONFIG_FSNOTIFY)
+ */
+#else
+
+#define trace_create_maxlat_file(tr, d_tracer)				\
+	trace_create_file("tracing_max_latency", 0644, d_tracer,	\
+			  &tr->max_latency, &tracing_max_lat_fops)
+
+#endif
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 /*
@@ -1508,8 +1766,8 @@
 static void
 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-	struct trace_buffer *trace_buf = &tr->trace_buffer;
-	struct trace_buffer *max_buf = &tr->max_buffer;
+	struct array_buffer *trace_buf = &tr->array_buffer;
+	struct array_buffer *max_buf = &tr->max_buffer;
 	struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu);
 	struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);
 
@@ -1537,6 +1795,7 @@
 
 	/* record this tasks comm */
 	tracing_record_cmdline(tsk);
+	latency_fsnotify(tr);
 }
 
 /**
@@ -1566,8 +1825,8 @@
 
 	arch_spin_lock(&tr->max_lock);
 
-	/* Inherit the recordable setting from trace_buffer */
-	if (ring_buffer_record_is_set_on(tr->trace_buffer.buffer))
+	/* Inherit the recordable setting from array_buffer */
+	if (ring_buffer_record_is_set_on(tr->array_buffer.buffer))
 		ring_buffer_record_on(tr->max_buffer.buffer);
 	else
 		ring_buffer_record_off(tr->max_buffer.buffer);
@@ -1576,7 +1835,7 @@
 	if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data))
 		goto out_unlock;
 #endif
-	swap(tr->trace_buffer.buffer, tr->max_buffer.buffer);
+	swap(tr->array_buffer.buffer, tr->max_buffer.buffer);
 
 	__update_max_tr(tr, tsk, cpu);
 
@@ -1609,7 +1868,7 @@
 
 	arch_spin_lock(&tr->max_lock);
 
-	ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu);
+	ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->array_buffer.buffer, cpu);
 
 	if (ret == -EBUSY) {
 		/*
@@ -1635,7 +1894,7 @@
 	if (trace_buffer_iter(iter, iter->cpu_file))
 		return 0;
 
-	return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file,
+	return ring_buffer_wait(iter->array_buffer->buffer, iter->cpu_file,
 				full);
 }
 
@@ -1686,7 +1945,7 @@
 	 * internal tracing to verify that everything is in order.
 	 * If we fail, we do not register this tracer.
 	 */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 	tr->current_trace = type;
 
@@ -1712,7 +1971,7 @@
 		return -1;
 	}
 	/* Only reset on passing, to avoid touching corrupted buffers */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (type->use_max_tr) {
@@ -1808,7 +2067,7 @@
 	}
 
 	if (security_locked_down(LOCKDOWN_TRACEFS)) {
-		pr_warning("Can not register tracer %s due to lockdown\n",
+		pr_warn("Can not register tracer %s due to lockdown\n",
 			   type->name);
 		return -EPERM;
 	}
@@ -1871,19 +2130,15 @@
 	apply_trace_boot_options();
 
 	/* disable other selftests, since this will break it. */
-	tracing_selftest_disabled = true;
-#ifdef CONFIG_FTRACE_STARTUP_TEST
-	printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n",
-	       type->name);
-#endif
+	disable_tracing_selftest("running a tracer");
 
  out_unlock:
 	return ret;
 }
 
-static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
+static void tracing_reset_cpu(struct array_buffer *buf, int cpu)
 {
-	struct ring_buffer *buffer = buf->buffer;
+	struct trace_buffer *buffer = buf->buffer;
 
 	if (!buffer)
 		return;
@@ -1897,10 +2152,9 @@
 	ring_buffer_record_enable(buffer);
 }
 
-void tracing_reset_online_cpus(struct trace_buffer *buf)
+void tracing_reset_online_cpus(struct array_buffer *buf)
 {
-	struct ring_buffer *buffer = buf->buffer;
-	int cpu;
+	struct trace_buffer *buffer = buf->buffer;
 
 	if (!buffer)
 		return;
@@ -1912,8 +2166,7 @@
 
 	buf->time_start = buffer_ftrace_now(buf, buf->cpu);
 
-	for_each_online_cpu(cpu)
-		ring_buffer_reset_cpu(buffer, cpu);
+	ring_buffer_reset_online_cpus(buffer);
 
 	ring_buffer_record_enable(buffer);
 }
@@ -1927,7 +2180,7 @@
 		if (!tr->clear_trace)
 			continue;
 		tr->clear_trace = false;
-		tracing_reset_online_cpus(&tr->trace_buffer);
+		tracing_reset_online_cpus(&tr->array_buffer);
 #ifdef CONFIG_TRACER_MAX_TRACE
 		tracing_reset_online_cpus(&tr->max_buffer);
 #endif
@@ -2021,7 +2274,7 @@
  */
 void tracing_start(void)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	if (tracing_disabled)
@@ -2040,7 +2293,7 @@
 	/* Prevent the buffers from switching */
 	arch_spin_lock(&global_trace.max_lock);
 
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_enable(buffer);
 
@@ -2058,7 +2311,7 @@
 
 static void tracing_start_tr(struct trace_array *tr)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	if (tracing_disabled)
@@ -2079,7 +2332,7 @@
 		goto out;
 	}
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_enable(buffer);
 
@@ -2095,7 +2348,7 @@
  */
 void tracing_stop(void)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
@@ -2105,7 +2358,7 @@
 	/* Prevent the buffers from switching */
 	arch_spin_lock(&global_trace.max_lock);
 
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_disable(buffer);
 
@@ -2123,7 +2376,7 @@
 
 static void tracing_stop_tr(struct trace_array *tr)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	/* If global, we need to also stop the max tracer */
@@ -2134,7 +2387,7 @@
 	if (tr->stop_count++)
 		goto out;
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_disable(buffer);
 
@@ -2369,7 +2622,7 @@
 EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
 
 struct ring_buffer_event *
-trace_buffer_lock_reserve(struct ring_buffer *buffer,
+trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags, int pc)
@@ -2419,7 +2672,7 @@
 
 		preempt_disable();
 		if (cpu == smp_processor_id() &&
-		    this_cpu_read(trace_buffered_event) !=
+		    __this_cpu_read(trace_buffered_event) !=
 		    per_cpu(trace_buffered_event, cpu))
 			WARN_ON_ONCE(1);
 		preempt_enable();
@@ -2488,10 +2741,10 @@
 	preempt_enable();
 }
 
-static struct ring_buffer *temp_buffer;
+static struct trace_buffer *temp_buffer;
 
 struct ring_buffer_event *
-trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
+trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 			  struct trace_event_file *trace_file,
 			  int type, unsigned long len,
 			  unsigned long flags, int pc)
@@ -2499,7 +2752,7 @@
 	struct ring_buffer_event *entry;
 	int val;
 
-	*current_rb = trace_file->tr->trace_buffer.buffer;
+	*current_rb = trace_file->tr->array_buffer.buffer;
 
 	if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags &
 	     (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
@@ -2537,6 +2790,7 @@
 static void output_printk(struct trace_event_buffer *fbuffer)
 {
 	struct trace_event_call *event_call;
+	struct trace_event_file *file;
 	struct trace_event *event;
 	unsigned long flags;
 	struct trace_iterator *iter = tracepoint_print_iter;
@@ -2550,6 +2804,12 @@
 	    !event_call->event.funcs->trace)
 		return;
 
+	file = fbuffer->trace_file;
+	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
+	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
+	     !filter_match_preds(file->filter, fbuffer->entry)))
+		return;
+
 	event = &fbuffer->trace_file->event_call->event;
 
 	spin_lock_irqsave(&tracepoint_iter_lock, flags);
@@ -2563,7 +2823,7 @@
 }
 
 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp,
+			     void *buffer, size_t *lenp,
 			     loff_t *ppos)
 {
 	int save_tracepoint_printk;
@@ -2600,9 +2860,11 @@
 	if (static_key_false(&tracepoint_printk_key.key))
 		output_printk(fbuffer);
 
-	event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
+	if (static_branch_unlikely(&trace_event_exports_enabled))
+		ftrace_exports(fbuffer->event, TRACE_EXPORT_EVENT);
+	event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer,
 				    fbuffer->event, fbuffer->entry,
-				    fbuffer->flags, fbuffer->pc);
+				    fbuffer->flags, fbuffer->pc, fbuffer->regs);
 }
 EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
 
@@ -2616,7 +2878,7 @@
 # define STACK_SKIP 3
 
 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
-				     struct ring_buffer *buffer,
+				     struct trace_buffer *buffer,
 				     struct ring_buffer_event *event,
 				     unsigned long flags, int pc,
 				     struct pt_regs *regs)
@@ -2637,142 +2899,19 @@
  * Similar to trace_buffer_unlock_commit_regs() but do not dump stack.
  */
 void
-trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
+trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 				   struct ring_buffer_event *event)
 {
 	__buffer_unlock_commit(buffer, event);
 }
 
-static void
-trace_process_export(struct trace_export *export,
-	       struct ring_buffer_event *event)
-{
-	struct trace_entry *entry;
-	unsigned int size = 0;
-
-	entry = ring_buffer_event_data(event);
-	size = ring_buffer_event_length(event);
-	export->write(export, entry, size);
-}
-
-static DEFINE_MUTEX(ftrace_export_lock);
-
-static struct trace_export __rcu *ftrace_exports_list __read_mostly;
-
-static DEFINE_STATIC_KEY_FALSE(ftrace_exports_enabled);
-
-static inline void ftrace_exports_enable(void)
-{
-	static_branch_enable(&ftrace_exports_enabled);
-}
-
-static inline void ftrace_exports_disable(void)
-{
-	static_branch_disable(&ftrace_exports_enabled);
-}
-
-static void ftrace_exports(struct ring_buffer_event *event)
-{
-	struct trace_export *export;
-
-	preempt_disable_notrace();
-
-	export = rcu_dereference_raw_check(ftrace_exports_list);
-	while (export) {
-		trace_process_export(export, event);
-		export = rcu_dereference_raw_check(export->next);
-	}
-
-	preempt_enable_notrace();
-}
-
-static inline void
-add_trace_export(struct trace_export **list, struct trace_export *export)
-{
-	rcu_assign_pointer(export->next, *list);
-	/*
-	 * We are entering export into the list but another
-	 * CPU might be walking that list. We need to make sure
-	 * the export->next pointer is valid before another CPU sees
-	 * the export pointer included into the list.
-	 */
-	rcu_assign_pointer(*list, export);
-}
-
-static inline int
-rm_trace_export(struct trace_export **list, struct trace_export *export)
-{
-	struct trace_export **p;
-
-	for (p = list; *p != NULL; p = &(*p)->next)
-		if (*p == export)
-			break;
-
-	if (*p != export)
-		return -1;
-
-	rcu_assign_pointer(*p, (*p)->next);
-
-	return 0;
-}
-
-static inline void
-add_ftrace_export(struct trace_export **list, struct trace_export *export)
-{
-	if (*list == NULL)
-		ftrace_exports_enable();
-
-	add_trace_export(list, export);
-}
-
-static inline int
-rm_ftrace_export(struct trace_export **list, struct trace_export *export)
-{
-	int ret;
-
-	ret = rm_trace_export(list, export);
-	if (*list == NULL)
-		ftrace_exports_disable();
-
-	return ret;
-}
-
-int register_ftrace_export(struct trace_export *export)
-{
-	if (WARN_ON_ONCE(!export->write))
-		return -1;
-
-	mutex_lock(&ftrace_export_lock);
-
-	add_ftrace_export(&ftrace_exports_list, export);
-
-	mutex_unlock(&ftrace_export_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(register_ftrace_export);
-
-int unregister_ftrace_export(struct trace_export *export)
-{
-	int ret;
-
-	mutex_lock(&ftrace_export_lock);
-
-	ret = rm_ftrace_export(&ftrace_exports_list, export);
-
-	mutex_unlock(&ftrace_export_lock);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(unregister_ftrace_export);
-
 void
 trace_function(struct trace_array *tr,
 	       unsigned long ip, unsigned long parent_ip, unsigned long flags,
 	       int pc)
 {
 	struct trace_event_call *call = &event_function;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct ftrace_entry *entry;
 
@@ -2785,8 +2924,8 @@
 	entry->parent_ip		= parent_ip;
 
 	if (!call_filter_check_discard(call, entry, buffer, event)) {
-		if (static_branch_unlikely(&ftrace_exports_enabled))
-			ftrace_exports(event);
+		if (static_branch_unlikely(&trace_function_exports_enabled))
+			ftrace_exports(event, TRACE_EXPORT_FUNCTION);
 		__buffer_unlock_commit(buffer, event);
 	}
 }
@@ -2810,7 +2949,7 @@
 static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks);
 static DEFINE_PER_CPU(int, ftrace_stack_reserve);
 
-static void __ftrace_trace_stack(struct ring_buffer *buffer,
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
 				 unsigned long flags,
 				 int skip, int pc, struct pt_regs *regs)
 {
@@ -2830,12 +2969,6 @@
 		skip++;
 #endif
 
-	/*
-	 * Since events can happen in NMIs there's no safe way to
-	 * use the per cpu ftrace_stacks. We reserve it and if an interrupt
-	 * or NMI comes in, it will just have to use the default
-	 * FTRACE_STACK_SIZE.
-	 */
 	preempt_disable_notrace();
 
 	stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1;
@@ -2886,7 +3019,7 @@
 }
 
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs)
 {
@@ -2899,7 +3032,7 @@
 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 		   int pc)
 {
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 
 	if (rcu_is_watching()) {
 		__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
@@ -2937,7 +3070,7 @@
 	/* Skip 1 to skip this function. */
 	skip++;
 #endif
-	__ftrace_trace_stack(global_trace.trace_buffer.buffer,
+	__ftrace_trace_stack(global_trace.array_buffer.buffer,
 			     flags, skip, preempt_count(), NULL);
 }
 EXPORT_SYMBOL_GPL(trace_dump_stack);
@@ -2947,7 +3080,7 @@
 
 static void
 ftrace_trace_userstack(struct trace_array *tr,
-		       struct ring_buffer *buffer, unsigned long flags, int pc)
+		       struct trace_buffer *buffer, unsigned long flags, int pc)
 {
 	struct trace_event_call *call = &event_user_stack;
 	struct ring_buffer_event *event;
@@ -2993,7 +3126,7 @@
 }
 #else /* CONFIG_USER_STACKTRACE_SUPPORT */
 static void ftrace_trace_userstack(struct trace_array *tr,
-				   struct ring_buffer *buffer,
+				   struct trace_buffer *buffer,
 				   unsigned long flags, int pc)
 {
 }
@@ -3007,7 +3140,7 @@
 	char buffer[4][TRACE_BUF_SIZE];
 };
 
-static struct trace_buffer_struct *trace_percpu_buffer;
+static struct trace_buffer_struct __percpu *trace_percpu_buffer;
 
 /*
  * Thise allows for lockless recording.  If we're nested too deeply, then
@@ -3017,7 +3150,7 @@
 {
 	struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer);
 
-	if (!buffer || buffer->nesting >= 4)
+	if (!trace_percpu_buffer || buffer->nesting >= 4)
 		return NULL;
 
 	buffer->nesting++;
@@ -3036,10 +3169,13 @@
 
 static int alloc_percpu_trace_buffer(void)
 {
-	struct trace_buffer_struct *buffers;
+	struct trace_buffer_struct __percpu *buffers;
+
+	if (trace_percpu_buffer)
+		return 0;
 
 	buffers = alloc_percpu(struct trace_buffer_struct);
-	if (WARN(!buffers, "Could not allocate percpu trace_printk buffer"))
+	if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer"))
 		return -ENOMEM;
 
 	trace_percpu_buffer = buffers;
@@ -3084,7 +3220,7 @@
 	 * directly here. If the global_trace.buffer is already
 	 * allocated here, then this was called by module code.
 	 */
-	if (global_trace.trace_buffer.buffer)
+	if (global_trace.array_buffer.buffer)
 		tracing_start_cmdline_record();
 }
 EXPORT_SYMBOL_GPL(trace_printk_init_buffers);
@@ -3118,7 +3254,7 @@
 {
 	struct trace_event_call *call = &event_bprint;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct trace_array *tr = &global_trace;
 	struct bprint_entry *entry;
 	unsigned long flags;
@@ -3143,11 +3279,12 @@
 	len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);
 
 	if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
-		goto out;
+		goto out_put;
 
 	local_save_flags(flags);
 	size = sizeof(*entry) + sizeof(u32) * len;
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
 					    flags, pc);
 	if (!event)
@@ -3163,6 +3300,8 @@
 	}
 
 out:
+	ring_buffer_nest_end(buffer);
+out_put:
 	put_trace_buf();
 
 out_nobuffer:
@@ -3175,7 +3314,7 @@
 
 __printf(3, 0)
 static int
-__trace_array_vprintk(struct ring_buffer *buffer,
+__trace_array_vprintk(struct trace_buffer *buffer,
 		      unsigned long ip, const char *fmt, va_list args)
 {
 	struct trace_event_call *call = &event_print;
@@ -3205,6 +3344,7 @@
 
 	local_save_flags(flags);
 	size = sizeof(*entry) + len + 1;
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
 					    flags, pc);
 	if (!event)
@@ -3219,6 +3359,7 @@
 	}
 
 out:
+	ring_buffer_nest_end(buffer);
 	put_trace_buf();
 
 out_nobuffer:
@@ -3232,9 +3373,29 @@
 int trace_array_vprintk(struct trace_array *tr,
 			unsigned long ip, const char *fmt, va_list args)
 {
-	return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args);
+	return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args);
 }
 
+/**
+ * trace_array_printk - Print a message to a specific instance
+ * @tr: The instance trace_array descriptor
+ * @ip: The instruction pointer that this is called from.
+ * @fmt: The format to print (printf format)
+ *
+ * If a subsystem sets up its own instance, they have the right to
+ * printk strings into their tracing instance buffer using this
+ * function. Note, this function will not write into the top level
+ * buffer (use trace_printk() for that), as writing into the top level
+ * buffer should only have events that can be individually disabled.
+ * trace_printk() is only used for debugging a kernel, and should not
+ * be ever encorporated in normal use.
+ *
+ * trace_array_printk() can be used, as it will not add noise to the
+ * top level tracing buffer.
+ *
+ * Note, trace_array_init_printk() must be called on @tr before this
+ * can be used.
+ */
 __printf(3, 0)
 int trace_array_printk(struct trace_array *tr,
 		       unsigned long ip, const char *fmt, ...)
@@ -3242,12 +3403,16 @@
 	int ret;
 	va_list ap;
 
-	if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
-		return 0;
-
 	if (!tr)
 		return -ENOENT;
 
+	/* This is only allowed for created instances */
+	if (tr == &global_trace)
+		return 0;
+
+	if (!(tr->trace_flags & TRACE_ITER_PRINTK))
+		return 0;
+
 	va_start(ap, fmt);
 	ret = trace_array_vprintk(tr, ip, fmt, ap);
 	va_end(ap);
@@ -3255,8 +3420,29 @@
 }
 EXPORT_SYMBOL_GPL(trace_array_printk);
 
+/**
+ * trace_array_init_printk - Initialize buffers for trace_array_printk()
+ * @tr: The trace array to initialize the buffers for
+ *
+ * As trace_array_printk() only writes into instances, they are OK to
+ * have in the kernel (unlike trace_printk()). This needs to be called
+ * before trace_array_printk() can be used on a trace_array.
+ */
+int trace_array_init_printk(struct trace_array *tr)
+{
+	if (!tr)
+		return -ENOENT;
+
+	/* This is only allowed for created instances */
+	if (tr == &global_trace)
+		return -EINVAL;
+
+	return alloc_percpu_trace_buffer();
+}
+EXPORT_SYMBOL_GPL(trace_array_init_printk);
+
 __printf(3, 4)
-int trace_array_printk_buf(struct ring_buffer *buffer,
+int trace_array_printk_buf(struct trace_buffer *buffer,
 			   unsigned long ip, const char *fmt, ...)
 {
 	int ret;
@@ -3284,7 +3470,7 @@
 
 	iter->idx++;
 	if (buf_iter)
-		ring_buffer_read(buf_iter, NULL);
+		ring_buffer_iter_advance(buf_iter);
 }
 
 static struct trace_entry *
@@ -3294,11 +3480,15 @@
 	struct ring_buffer_event *event;
 	struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);
 
-	if (buf_iter)
+	if (buf_iter) {
 		event = ring_buffer_iter_peek(buf_iter, ts);
-	else
-		event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts,
+		if (lost_events)
+			*lost_events = ring_buffer_iter_dropped(buf_iter) ?
+				(unsigned long)-1 : 0;
+	} else {
+		event = ring_buffer_peek(iter->array_buffer->buffer, cpu, ts,
 					 lost_events);
+	}
 
 	if (event) {
 		iter->ent_size = ring_buffer_event_length(event);
@@ -3312,7 +3502,7 @@
 __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
 		  unsigned long *missing_events, u64 *ent_ts)
 {
-	struct ring_buffer *buffer = iter->trace_buffer->buffer;
+	struct trace_buffer *buffer = iter->array_buffer->buffer;
 	struct trace_entry *ent, *next = NULL;
 	unsigned long lost_events = 0, next_lost = 0;
 	int cpu_file = iter->cpu_file;
@@ -3368,11 +3558,53 @@
 	return next;
 }
 
+#define STATIC_TEMP_BUF_SIZE	128
+static char static_temp_buf[STATIC_TEMP_BUF_SIZE] __aligned(4);
+
 /* Find the next real entry, without updating the iterator itself */
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 					  int *ent_cpu, u64 *ent_ts)
 {
-	return __find_next_entry(iter, ent_cpu, NULL, ent_ts);
+	/* __find_next_entry will reset ent_size */
+	int ent_size = iter->ent_size;
+	struct trace_entry *entry;
+
+	/*
+	 * If called from ftrace_dump(), then the iter->temp buffer
+	 * will be the static_temp_buf and not created from kmalloc.
+	 * If the entry size is greater than the buffer, we can
+	 * not save it. Just return NULL in that case. This is only
+	 * used to add markers when two consecutive events' time
+	 * stamps have a large delta. See trace_print_lat_context()
+	 */
+	if (iter->temp == static_temp_buf &&
+	    STATIC_TEMP_BUF_SIZE < ent_size)
+		return NULL;
+
+	/*
+	 * The __find_next_entry() may call peek_next_entry(), which may
+	 * call ring_buffer_peek() that may make the contents of iter->ent
+	 * undefined. Need to copy iter->ent now.
+	 */
+	if (iter->ent && iter->ent != iter->temp) {
+		if ((!iter->temp || iter->temp_size < iter->ent_size) &&
+		    !WARN_ON_ONCE(iter->temp == static_temp_buf)) {
+			void *temp;
+			temp = kmalloc(iter->ent_size, GFP_KERNEL);
+			if (!temp)
+				return NULL;
+			kfree(iter->temp);
+			iter->temp = temp;
+			iter->temp_size = iter->ent_size;
+		}
+		memcpy(iter->temp, iter->ent, iter->ent_size);
+		iter->ent = iter->temp;
+	}
+	entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts);
+	/* Put back the original ent_size */
+	iter->ent_size = ent_size;
+
+	return entry;
 }
 
 /* Find the next real entry, and increment the iterator to the next entry */
@@ -3389,7 +3621,7 @@
 
 static void trace_consume(struct trace_iterator *iter)
 {
-	ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts,
+	ring_buffer_consume(iter->array_buffer->buffer, iter->cpu, &iter->ts,
 			    &iter->lost_events);
 }
 
@@ -3422,12 +3654,11 @@
 
 void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 {
-	struct ring_buffer_event *event;
 	struct ring_buffer_iter *buf_iter;
 	unsigned long entries = 0;
 	u64 ts;
 
-	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0;
+	per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = 0;
 
 	buf_iter = trace_buffer_iter(iter, cpu);
 	if (!buf_iter)
@@ -3440,14 +3671,14 @@
 	 * that a reset never took place on a cpu. This is evident
 	 * by the timestamp being before the start of the buffer.
 	 */
-	while ((event = ring_buffer_iter_peek(buf_iter, &ts))) {
-		if (ts >= iter->trace_buffer->time_start)
+	while (ring_buffer_iter_peek(buf_iter, &ts)) {
+		if (ts >= iter->array_buffer->time_start)
 			break;
 		entries++;
-		ring_buffer_read(buf_iter, NULL);
+		ring_buffer_iter_advance(buf_iter);
 	}
 
-	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries;
+	per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries;
 }
 
 /*
@@ -3526,7 +3757,7 @@
 }
 
 static void
-get_total_entries_cpu(struct trace_buffer *buf, unsigned long *total,
+get_total_entries_cpu(struct array_buffer *buf, unsigned long *total,
 		      unsigned long *entries, int cpu)
 {
 	unsigned long count;
@@ -3548,7 +3779,7 @@
 }
 
 static void
-get_total_entries(struct trace_buffer *buf,
+get_total_entries(struct array_buffer *buf,
 		  unsigned long *total, unsigned long *entries)
 {
 	unsigned long t, e;
@@ -3571,7 +3802,7 @@
 	if (!tr)
 		tr = &global_trace;
 
-	get_total_entries_cpu(&tr->trace_buffer, &total, &entries, cpu);
+	get_total_entries_cpu(&tr->array_buffer, &total, &entries, cpu);
 
 	return entries;
 }
@@ -3583,7 +3814,7 @@
 	if (!tr)
 		tr = &global_trace;
 
-	get_total_entries(&tr->trace_buffer, &total, &entries);
+	get_total_entries(&tr->array_buffer, &total, &entries);
 
 	return entries;
 }
@@ -3600,7 +3831,7 @@
 		    "#     \\   /        |||||  \\    |   /         \n");
 }
 
-static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
+static void print_event_info(struct array_buffer *buf, struct seq_file *m)
 {
 	unsigned long total;
 	unsigned long entries;
@@ -3611,7 +3842,7 @@
 	seq_puts(m, "#\n");
 }
 
-static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m,
+static void print_func_help_header(struct array_buffer *buf, struct seq_file *m,
 				   unsigned int flags)
 {
 	bool tgid = flags & TRACE_ITER_RECORD_TGID;
@@ -3622,7 +3853,7 @@
 	seq_printf(m, "#              | |      %s   |         |         |\n",      tgid ? "     |    " : "");
 }
 
-static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m,
+static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file *m,
 				       unsigned int flags)
 {
 	bool tgid = flags & TRACE_ITER_RECORD_TGID;
@@ -3644,7 +3875,7 @@
 print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 {
 	unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK);
-	struct trace_buffer *buf = iter->trace_buffer;
+	struct array_buffer *buf = iter->array_buffer;
 	struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
 	struct tracer *type = iter->trace;
 	unsigned long entries;
@@ -3671,6 +3902,8 @@
 		   "desktop",
 #elif defined(CONFIG_PREEMPT)
 		   "preempt",
+#elif defined(CONFIG_PREEMPT_RT)
+		   "preempt_rt",
 #else
 		   "unknown",
 #endif
@@ -3717,7 +3950,7 @@
 	    cpumask_test_cpu(iter->cpu, iter->started))
 		return;
 
-	if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries)
+	if (per_cpu_ptr(iter->array_buffer->data, iter->cpu)->skipped_entries)
 		return;
 
 	if (cpumask_available(iter->started))
@@ -3851,7 +4084,7 @@
 			if (!ring_buffer_iter_empty(buf_iter))
 				return 0;
 		} else {
-			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
+			if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
 				return 0;
 		}
 		return 1;
@@ -3863,7 +4096,7 @@
 			if (!ring_buffer_iter_empty(buf_iter))
 				return 0;
 		} else {
-			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
+			if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
 				return 0;
 		}
 	}
@@ -3879,8 +4112,12 @@
 	enum print_line_t ret;
 
 	if (iter->lost_events) {
-		trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
-				 iter->cpu, iter->lost_events);
+		if (iter->lost_events == (unsigned long)-1)
+			trace_seq_printf(&iter->seq, "CPU:%d [LOST EVENTS]\n",
+					 iter->cpu);
+		else
+			trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
+					 iter->cpu, iter->lost_events);
 		if (trace_seq_has_overflowed(&iter->seq))
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
@@ -3953,10 +4190,10 @@
 	} else {
 		if (!(trace_flags & TRACE_ITER_VERBOSE)) {
 			if (trace_flags & TRACE_ITER_IRQ_INFO)
-				print_func_help_header_irq(iter->trace_buffer,
+				print_func_help_header_irq(iter->array_buffer,
 							   m, trace_flags);
 			else
-				print_func_help_header(iter->trace_buffer, m,
+				print_func_help_header(iter->array_buffer, m,
 						       trace_flags);
 		}
 	}
@@ -4096,6 +4333,18 @@
 		goto release;
 
 	/*
+	 * trace_find_next_entry() may need to save off iter->ent.
+	 * It will place it into the iter->temp buffer. As most
+	 * events are less than 128, allocate a buffer of that size.
+	 * If one is greater, then trace_find_next_entry() will
+	 * allocate a new buffer to adjust for the bigger iter->ent.
+	 * It's not critical if it fails to get allocated here.
+	 */
+	iter->temp = kmalloc(128, GFP_KERNEL);
+	if (iter->temp)
+		iter->temp_size = 128;
+
+	/*
 	 * We make a copy of the current tracer to avoid concurrent
 	 * changes on it while we are reading.
 	 */
@@ -4114,35 +4363,38 @@
 #ifdef CONFIG_TRACER_MAX_TRACE
 	/* Currently only the top directory has a snapshot */
 	if (tr->current_trace->print_max || snapshot)
-		iter->trace_buffer = &tr->max_buffer;
+		iter->array_buffer = &tr->max_buffer;
 	else
 #endif
-		iter->trace_buffer = &tr->trace_buffer;
+		iter->array_buffer = &tr->array_buffer;
 	iter->snapshot = snapshot;
 	iter->pos = -1;
 	iter->cpu_file = tracing_get_cpu(inode);
 	mutex_init(&iter->mutex);
 
 	/* Notify the tracer early; before we stop tracing. */
-	if (iter->trace && iter->trace->open)
+	if (iter->trace->open)
 		iter->trace->open(iter);
 
 	/* Annotate start of buffers if we had overruns */
-	if (ring_buffer_overruns(iter->trace_buffer->buffer))
+	if (ring_buffer_overruns(iter->array_buffer->buffer))
 		iter->iter_flags |= TRACE_FILE_ANNOTATE;
 
 	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
 	if (trace_clocks[tr->clock_id].in_ns)
 		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
-	/* stop the trace while dumping if we are not opening "snapshot" */
-	if (!iter->snapshot)
+	/*
+	 * If pause-on-trace is enabled, then stop the trace while
+	 * dumping, unless this is the "snapshot" file
+	 */
+	if (!iter->snapshot && (tr->trace_flags & TRACE_ITER_PAUSE_ON_TRACE))
 		tracing_stop_tr(tr);
 
 	if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
 		for_each_tracing_cpu(cpu) {
 			iter->buffer_iter[cpu] =
-				ring_buffer_read_prepare(iter->trace_buffer->buffer,
+				ring_buffer_read_prepare(iter->array_buffer->buffer,
 							 cpu, GFP_KERNEL);
 		}
 		ring_buffer_read_prepare_sync();
@@ -4153,7 +4405,7 @@
 	} else {
 		cpu = iter->cpu_file;
 		iter->buffer_iter[cpu] =
-			ring_buffer_read_prepare(iter->trace_buffer->buffer,
+			ring_buffer_read_prepare(iter->array_buffer->buffer,
 						 cpu, GFP_KERNEL);
 		ring_buffer_read_prepare_sync();
 		ring_buffer_read_start(iter->buffer_iter[cpu]);
@@ -4167,6 +4419,7 @@
  fail:
 	mutex_unlock(&trace_types_lock);
 	kfree(iter->trace);
+	kfree(iter->temp);
 	kfree(iter->buffer_iter);
 release:
 	seq_release_private(inode, file);
@@ -4232,7 +4485,7 @@
 	if (iter->trace && iter->trace->close)
 		iter->trace->close(iter);
 
-	if (!iter->snapshot)
+	if (!iter->snapshot && tr->stop_count)
 		/* reenable tracing if it was previously enabled */
 		tracing_start_tr(tr);
 
@@ -4242,6 +4495,7 @@
 
 	mutex_destroy(&iter->mutex);
 	free_cpumask_var(iter->started);
+	kfree(iter->temp);
 	kfree(iter->trace);
 	kfree(iter->buffer_iter);
 	seq_release_private(inode, file);
@@ -4279,7 +4533,7 @@
 	/* If this file was open for write, then erase contents */
 	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 		int cpu = tracing_get_cpu(inode);
-		struct trace_buffer *trace_buf = &tr->trace_buffer;
+		struct array_buffer *trace_buf = &tr->array_buffer;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 		if (tr->current_trace->print_max)
@@ -4476,20 +4730,13 @@
 	return count;
 }
 
-static ssize_t
-tracing_cpumask_write(struct file *filp, const char __user *ubuf,
-		      size_t count, loff_t *ppos)
+int tracing_set_cpumask(struct trace_array *tr,
+			cpumask_var_t tracing_cpumask_new)
 {
-	struct trace_array *tr = file_inode(filp)->i_private;
-	cpumask_var_t tracing_cpumask_new;
-	int err, cpu;
+	int cpu;
 
-	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
-		return -ENOMEM;
-
-	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
-	if (err)
-		goto err_unlock;
+	if (!tr)
+		return -EINVAL;
 
 	local_irq_disable();
 	arch_spin_lock(&tr->max_lock);
@@ -4500,24 +4747,47 @@
 		 */
 		if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
 				!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
-			atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
-			ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu);
+			atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
+			ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu);
 		}
 		if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
 				cpumask_test_cpu(cpu, tracing_cpumask_new)) {
-			atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
-			ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu);
+			atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
+			ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu);
 		}
 	}
 	arch_spin_unlock(&tr->max_lock);
 	local_irq_enable();
 
 	cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);
+
+	return 0;
+}
+
+static ssize_t
+tracing_cpumask_write(struct file *filp, const char __user *ubuf,
+		      size_t count, loff_t *ppos)
+{
+	struct trace_array *tr = file_inode(filp)->i_private;
+	cpumask_var_t tracing_cpumask_new;
+	int err;
+
+	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
+		return -ENOMEM;
+
+	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
+	if (err)
+		goto err_free;
+
+	err = tracing_set_cpumask(tr, tracing_cpumask_new);
+	if (err)
+		goto err_free;
+
 	free_cpumask_var(tracing_cpumask_new);
 
 	return count;
 
-err_unlock:
+err_free:
 	free_cpumask_var(tracing_cpumask_new);
 
 	return err;
@@ -4659,7 +4929,7 @@
 		ftrace_pid_follow_fork(tr, enabled);
 
 	if (mask == TRACE_ITER_OVERWRITE) {
-		ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled);
+		ring_buffer_change_overwrite(tr->array_buffer.buffer, enabled);
 #ifdef CONFIG_TRACER_MAX_TRACE
 		ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
 #endif
@@ -4673,7 +4943,7 @@
 	return 0;
 }
 
-static int trace_set_options(struct trace_array *tr, char *option)
+int trace_set_options(struct trace_array *tr, char *option)
 {
 	char *cmp;
 	int neg = 0;
@@ -4857,6 +5127,8 @@
 #ifdef CONFIG_FUNCTION_TRACER
 	"  set_ftrace_pid\t- Write pid(s) to only function trace those pids\n"
 	"\t\t    (function)\n"
+	"  set_ftrace_notrace_pid\t- Write pid(s) to not function trace those pids\n"
+	"\t\t    (function)\n"
 #endif
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	"  set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
@@ -4900,10 +5172,10 @@
 	"\t           -:[<group>/]<event>\n"
 #ifdef CONFIG_KPROBE_EVENTS
 	"\t    place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
-  "place (kretprobe): [<module>:]<symbol>[+<offset>]|<memaddr>\n"
+  "place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"
 #endif
 #ifdef CONFIG_UPROBE_EVENTS
-  "   place (uprobe): <path>:<offset>[(ref_ctr_offset)]\n"
+  "   place (uprobe): <path>:<offset>[%return][(ref_ctr_offset)]\n"
 #endif
 	"\t     args: <name>=fetcharg[:type]\n"
 	"\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n"
@@ -5031,7 +5303,12 @@
 	"\t        trace(<synthetic_event>,param list)  - generate synthetic event\n"
 	"\t        save(field,...)                      - save current event fields\n"
 #ifdef CONFIG_TRACER_SNAPSHOT
-	"\t        snapshot()                           - snapshot the trace buffer\n"
+	"\t        snapshot()                           - snapshot the trace buffer\n\n"
+#endif
+#ifdef CONFIG_SYNTH_EVENTS
+	"  events/synthetic_events\t- Create/append/remove/show synthetic events\n"
+	"\t  Write into this file to define/undefine new synthetic events.\n"
+	"\t     example: echo 'myevent u64 lat; char name[]' >> synthetic_events\n"
 #endif
 #endif
 ;
@@ -5282,14 +5559,12 @@
 	 * Paranoid! If ptr points to end, we don't want to increment past it.
 	 * This really should never happen.
 	 */
+	(*pos)++;
 	ptr = update_eval_map(ptr);
 	if (WARN_ON_ONCE(!ptr))
 		return NULL;
 
 	ptr++;
-
-	(*pos)++;
-
 	ptr = update_eval_map(ptr);
 
 	return ptr;
@@ -5455,11 +5730,11 @@
 
 int tracer_init(struct tracer *t, struct trace_array *tr)
 {
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 	return t->init(tr);
 }
 
-static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)
+static void set_buffer_entries(struct array_buffer *buf, unsigned long val)
 {
 	int cpu;
 
@@ -5469,8 +5744,8 @@
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 /* resize @tr's buffer to the size of @size_tr's entries */
-static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
-					struct trace_buffer *size_buf, int cpu_id)
+static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
+					struct array_buffer *size_buf, int cpu_id)
 {
 	int cpu, ret = 0;
 
@@ -5508,10 +5783,10 @@
 	ring_buffer_expanded = true;
 
 	/* May be called before buffers are initialized */
-	if (!tr->trace_buffer.buffer)
+	if (!tr->array_buffer.buffer)
 		return 0;
 
-	ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu);
+	ret = ring_buffer_resize(tr->array_buffer.buffer, size, cpu);
 	if (ret < 0)
 		return ret;
 
@@ -5522,8 +5797,8 @@
 
 	ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu);
 	if (ret < 0) {
-		int r = resize_buffer_duplicate_size(&tr->trace_buffer,
-						     &tr->trace_buffer, cpu);
+		int r = resize_buffer_duplicate_size(&tr->array_buffer,
+						     &tr->array_buffer, cpu);
 		if (r < 0) {
 			/*
 			 * AARGH! We are left with different
@@ -5554,15 +5829,15 @@
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
 	if (cpu == RING_BUFFER_ALL_CPUS)
-		set_buffer_entries(&tr->trace_buffer, size);
+		set_buffer_entries(&tr->array_buffer, size);
 	else
-		per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size;
+		per_cpu_ptr(tr->array_buffer.data, cpu)->entries = size;
 
 	return ret;
 }
 
-static ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
-					  unsigned long size, int cpu_id)
+ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
+				  unsigned long size, int cpu_id)
 {
 	int ret = size;
 
@@ -5641,7 +5916,7 @@
 	create_trace_option_files(tr, t);
 }
 
-static int tracing_set_tracer(struct trace_array *tr, const char *buf)
+int tracing_set_tracer(struct trace_array *tr, const char *buf)
 {
 	struct tracer *t;
 #ifdef CONFIG_TRACER_MAX_TRACE
@@ -5900,7 +6175,7 @@
 		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
 	iter->tr = tr;
-	iter->trace_buffer = &tr->trace_buffer;
+	iter->array_buffer = &tr->array_buffer;
 	iter->cpu_file = tracing_get_cpu(inode);
 	mutex_init(&iter->mutex);
 	filp->private_data = iter;
@@ -5960,7 +6235,7 @@
 		 */
 		return EPOLLIN | EPOLLRDNORM;
 	else
-		return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file,
+		return ring_buffer_poll_wait(iter->array_buffer->buffer, iter->cpu_file,
 					     filp, poll_table);
 }
 
@@ -6114,13 +6389,6 @@
 	__free_page(spd->pages[idx]);
 }
 
-static const struct pipe_buf_operations tracing_pipe_buf_ops = {
-	.confirm		= generic_pipe_buf_confirm,
-	.release		= generic_pipe_buf_release,
-	.steal			= generic_pipe_buf_steal,
-	.get			= generic_pipe_buf_get,
-};
-
 static size_t
 tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
 {
@@ -6182,7 +6450,7 @@
 		.partial	= partial_def,
 		.nr_pages	= 0, /* This gets updated below. */
 		.nr_pages_max	= PIPE_DEF_BUFFERS,
-		.ops		= &tracing_pipe_buf_ops,
+		.ops		= &default_pipe_buf_ops,
 		.spd_release	= tracing_spd_release_pipe,
 	};
 	ssize_t ret;
@@ -6277,8 +6545,8 @@
 		for_each_tracing_cpu(cpu) {
 			/* fill in the size from first enabled cpu */
 			if (size == 0)
-				size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries;
-			if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) {
+				size = per_cpu_ptr(tr->array_buffer.data, cpu)->entries;
+			if (size != per_cpu_ptr(tr->array_buffer.data, cpu)->entries) {
 				buf_size_same = 0;
 				break;
 			}
@@ -6294,7 +6562,7 @@
 		} else
 			r = sprintf(buf, "X\n");
 	} else
-		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10);
+		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10);
 
 	mutex_unlock(&trace_types_lock);
 
@@ -6341,7 +6609,7 @@
 
 	mutex_lock(&trace_types_lock);
 	for_each_tracing_cpu(cpu) {
-		size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10;
+		size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10;
 		if (!ring_buffer_expanded)
 			expanded_size += trace_buf_size >> 10;
 	}
@@ -6391,7 +6659,7 @@
 	struct trace_array *tr = filp->private_data;
 	struct ring_buffer_event *event;
 	enum event_trigger_type tt = ETT_NONE;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	ssize_t written;
@@ -6420,7 +6688,7 @@
 	if (cnt < FAULTED_SIZE)
 		size += FAULTED_SIZE - cnt;
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
 					    irq_flags, preempt_count());
 	if (unlikely(!event))
@@ -6437,7 +6705,6 @@
 		written = -EFAULT;
 	} else
 		written = cnt;
-	len = cnt;
 
 	if (tr->trace_marker_file && !list_empty(&tr->trace_marker_file->triggers)) {
 		/* do not add \n before testing triggers, but add \0 */
@@ -6451,6 +6718,8 @@
 	} else
 		entry->buf[cnt] = '\0';
 
+	if (static_branch_unlikely(&trace_marker_exports_enabled))
+		ftrace_exports(event, TRACE_EXPORT_MARKER);
 	__buffer_unlock_commit(buffer, event);
 
 	if (tt)
@@ -6471,7 +6740,7 @@
 {
 	struct trace_array *tr = filp->private_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct raw_data_entry *entry;
 	unsigned long irq_flags;
 	ssize_t written;
@@ -6500,7 +6769,7 @@
 	if (cnt < FAULT_SIZE_ID)
 		size += FAULT_SIZE_ID - cnt;
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size,
 					    irq_flags, preempt_count());
 	if (!event)
@@ -6555,13 +6824,13 @@
 
 	tr->clock_id = i;
 
-	ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func);
+	ring_buffer_set_clock(tr->array_buffer.buffer, trace_clocks[i].func);
 
 	/*
 	 * New clock may not be consistent with the previous clock.
 	 * Reset the buffer so that it doesn't have incomparable timestamps.
 	 */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (tr->max_buffer.buffer)
@@ -6624,7 +6893,7 @@
 
 	mutex_lock(&trace_types_lock);
 
-	if (ring_buffer_time_stamp_abs(tr->trace_buffer.buffer))
+	if (ring_buffer_time_stamp_abs(tr->array_buffer.buffer))
 		seq_puts(m, "delta [absolute]\n");
 	else
 		seq_puts(m, "[delta] absolute\n");
@@ -6669,7 +6938,7 @@
 			goto out;
 	}
 
-	ring_buffer_set_time_stamp_abs(tr->trace_buffer.buffer, abs);
+	ring_buffer_set_time_stamp_abs(tr->array_buffer.buffer, abs);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (tr->max_buffer.buffer)
@@ -6718,7 +6987,7 @@
 		ret = 0;
 
 		iter->tr = tr;
-		iter->trace_buffer = &tr->max_buffer;
+		iter->array_buffer = &tr->max_buffer;
 		iter->cpu_file = tracing_get_cpu(inode);
 		m->private = iter;
 		file->private_data = m;
@@ -6781,7 +7050,7 @@
 #endif
 		if (tr->allocated_snapshot)
 			ret = resize_buffer_duplicate_size(&tr->max_buffer,
-					&tr->trace_buffer, iter->cpu_file);
+					&tr->array_buffer, iter->cpu_file);
 		else
 			ret = tracing_alloc_snapshot_instance(tr);
 		if (ret < 0)
@@ -6856,7 +7125,7 @@
 	}
 
 	info->iter.snapshot = true;
-	info->iter.trace_buffer = &info->iter.tr->max_buffer;
+	info->iter.array_buffer = &info->iter.tr->max_buffer;
 
 	return ret;
 }
@@ -6994,7 +7263,8 @@
 		err = kzalloc(sizeof(*err), GFP_KERNEL);
 		if (!err)
 			err = ERR_PTR(-ENOMEM);
-		tr->n_err_log_entries++;
+		else
+			tr->n_err_log_entries++;
 
 		return err;
 	}
@@ -7220,7 +7490,7 @@
 	if (ret)
 		return ret;
 
-	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	info = kvzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {
 		trace_array_put(tr);
 		return -ENOMEM;
@@ -7231,7 +7501,7 @@
 	info->iter.tr		= tr;
 	info->iter.cpu_file	= tracing_get_cpu(inode);
 	info->iter.trace	= tr->current_trace;
-	info->iter.trace_buffer = &tr->trace_buffer;
+	info->iter.array_buffer = &tr->array_buffer;
 	info->spare		= NULL;
 	/* Force reading ring buffer for first read */
 	info->read		= (unsigned int)-1;
@@ -7276,7 +7546,7 @@
 #endif
 
 	if (!info->spare) {
-		info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,
+		info->spare = ring_buffer_alloc_read_page(iter->array_buffer->buffer,
 							  iter->cpu_file);
 		if (IS_ERR(info->spare)) {
 			ret = PTR_ERR(info->spare);
@@ -7294,7 +7564,7 @@
 
  again:
 	trace_access_lock(iter->cpu_file);
-	ret = ring_buffer_read_page(iter->trace_buffer->buffer,
+	ret = ring_buffer_read_page(iter->array_buffer->buffer,
 				    &info->spare,
 				    count,
 				    iter->cpu_file, 0);
@@ -7344,9 +7614,9 @@
 	__trace_array_put(iter->tr);
 
 	if (info->spare)
-		ring_buffer_free_read_page(iter->trace_buffer->buffer,
+		ring_buffer_free_read_page(iter->array_buffer->buffer,
 					   info->spare_cpu, info->spare);
-	kfree(info);
+	kvfree(info);
 
 	mutex_unlock(&trace_types_lock);
 
@@ -7354,7 +7624,7 @@
 }
 
 struct buffer_ref {
-	struct ring_buffer	*buffer;
+	struct trace_buffer	*buffer;
 	void			*page;
 	int			cpu;
 	refcount_t		refcount;
@@ -7391,9 +7661,7 @@
 
 /* Pipe buffer operations for a buffer. */
 static const struct pipe_buf_operations buffer_pipe_buf_ops = {
-	.confirm		= generic_pipe_buf_confirm,
 	.release		= buffer_pipe_buf_release,
-	.steal			= generic_pipe_buf_nosteal,
 	.get			= buffer_pipe_buf_get,
 };
 
@@ -7449,7 +7717,7 @@
 
  again:
 	trace_access_lock(iter->cpu_file);
-	entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
+	entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
 
 	for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) {
 		struct page *page;
@@ -7462,7 +7730,7 @@
 		}
 
 		refcount_set(&ref->refcount, 1);
-		ref->buffer = iter->trace_buffer->buffer;
+		ref->buffer = iter->array_buffer->buffer;
 		ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
 		if (IS_ERR(ref->page)) {
 			ret = PTR_ERR(ref->page);
@@ -7490,7 +7758,7 @@
 		spd.nr_pages++;
 		*ppos += PAGE_SIZE;
 
-		entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
+		entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
 	}
 
 	trace_access_unlock(iter->cpu_file);
@@ -7534,7 +7802,7 @@
 {
 	struct inode *inode = file_inode(filp);
 	struct trace_array *tr = inode->i_private;
-	struct trace_buffer *trace_buf = &tr->trace_buffer;
+	struct array_buffer *trace_buf = &tr->array_buffer;
 	int cpu = tracing_get_cpu(inode);
 	struct trace_seq *s;
 	unsigned long cnt;
@@ -7605,14 +7873,23 @@
 tracing_read_dyn_info(struct file *filp, char __user *ubuf,
 		  size_t cnt, loff_t *ppos)
 {
-	unsigned long *p = filp->private_data;
-	char buf[64]; /* Not too big for a shallow stack */
+	ssize_t ret;
+	char *buf;
 	int r;
 
-	r = scnprintf(buf, 63, "%ld", *p);
-	buf[r++] = '\n';
+	/* 256 should be plenty to hold the amount needed */
+	buf = kmalloc(256, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
 
-	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+	r = scnprintf(buf, 256, "%ld pages:%ld groups: %ld\n",
+		      ftrace_update_tot_cnt,
+		      ftrace_number_of_pages,
+		      ftrace_number_of_groups);
+
+	ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+	kfree(buf);
+	return ret;
 }
 
 static const struct file_operations tracing_dyn_info_fops = {
@@ -7806,7 +8083,7 @@
 
 	tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer);
 
-	WARN_ONCE(!tr->percpu_dir,
+	MEM_FAIL(!tr->percpu_dir,
 		  "Could not create tracefs directory 'per_cpu/%d'\n", cpu);
 
 	return tr->percpu_dir;
@@ -8127,7 +8404,7 @@
 	for (cnt = 0; opts[cnt].name; cnt++) {
 		create_trace_option_file(tr, &topts[cnt], flags,
 					 &opts[cnt]);
-		WARN_ONCE(topts[cnt].entry == NULL,
+		MEM_FAIL(topts[cnt].entry == NULL,
 			  "Failed to create trace option: %s",
 			  opts[cnt].name);
 	}
@@ -8184,7 +8461,7 @@
 		size_t cnt, loff_t *ppos)
 {
 	struct trace_array *tr = filp->private_data;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	unsigned long val;
 	int ret;
 
@@ -8274,7 +8551,7 @@
 init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
 
 static int
-allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)
+allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size)
 {
 	enum ring_buffer_flags rb_flags;
 
@@ -8294,8 +8571,8 @@
 	}
 
 	/* Allocate the first page for all buffers */
-	set_buffer_entries(&tr->trace_buffer,
-			   ring_buffer_size(tr->trace_buffer.buffer, 0));
+	set_buffer_entries(&tr->array_buffer,
+			   ring_buffer_size(tr->array_buffer.buffer, 0));
 
 	return 0;
 }
@@ -8304,18 +8581,18 @@
 {
 	int ret;
 
-	ret = allocate_trace_buffer(tr, &tr->trace_buffer, size);
+	ret = allocate_trace_buffer(tr, &tr->array_buffer, size);
 	if (ret)
 		return ret;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	ret = allocate_trace_buffer(tr, &tr->max_buffer,
 				    allocate_snapshot ? size : 1);
-	if (WARN_ON(ret)) {
-		ring_buffer_free(tr->trace_buffer.buffer);
-		tr->trace_buffer.buffer = NULL;
-		free_percpu(tr->trace_buffer.data);
-		tr->trace_buffer.data = NULL;
+	if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) {
+		ring_buffer_free(tr->array_buffer.buffer);
+		tr->array_buffer.buffer = NULL;
+		free_percpu(tr->array_buffer.data);
+		tr->array_buffer.data = NULL;
 		return -ENOMEM;
 	}
 	tr->allocated_snapshot = allocate_snapshot;
@@ -8327,22 +8604,10 @@
 	allocate_snapshot = false;
 #endif
 
-	/*
-	 * Because of some magic with the way alloc_percpu() works on
-	 * x86_64, we need to synchronize the pgd of all the tables,
-	 * otherwise the trace events that happen in x86_64 page fault
-	 * handlers can't cope with accessing the chance that a
-	 * alloc_percpu()'d memory might be touched in the page fault trace
-	 * event. Oh, and we need to audit all other alloc_percpu() and vmalloc()
-	 * calls in tracing, because something might get triggered within a
-	 * page fault trace event!
-	 */
-	vmalloc_sync_mappings();
-
 	return 0;
 }
 
-static void free_trace_buffer(struct trace_buffer *buf)
+static void free_trace_buffer(struct array_buffer *buf)
 {
 	if (buf->buffer) {
 		ring_buffer_free(buf->buffer);
@@ -8357,7 +8622,7 @@
 	if (!tr)
 		return;
 
-	free_trace_buffer(&tr->trace_buffer);
+	free_trace_buffer(&tr->array_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	free_trace_buffer(&tr->max_buffer);
@@ -8388,24 +8653,63 @@
 	mutex_unlock(&trace_types_lock);
 }
 
-struct trace_array *trace_array_create(const char *name)
+/* Must have trace_types_lock held */
+struct trace_array *trace_array_find(const char *instance)
+{
+	struct trace_array *tr, *found = NULL;
+
+	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+		if (tr->name && strcmp(tr->name, instance) == 0) {
+			found = tr;
+			break;
+		}
+	}
+
+	return found;
+}
+
+struct trace_array *trace_array_find_get(const char *instance)
+{
+	struct trace_array *tr;
+
+	mutex_lock(&trace_types_lock);
+	tr = trace_array_find(instance);
+	if (tr)
+		tr->ref++;
+	mutex_unlock(&trace_types_lock);
+
+	return tr;
+}
+
+static int trace_array_create_dir(struct trace_array *tr)
+{
+	int ret;
+
+	tr->dir = tracefs_create_dir(tr->name, trace_instance_dir);
+	if (!tr->dir)
+		return -EINVAL;
+
+	ret = event_trace_add_tracer(tr->dir, tr);
+	if (ret) {
+		tracefs_remove(tr->dir);
+		return ret;
+	}
+
+	init_tracer_tracefs(tr, tr->dir);
+	__update_tracer_options(tr);
+
+	return ret;
+}
+
+static struct trace_array *trace_array_create(const char *name)
 {
 	struct trace_array *tr;
 	int ret;
 
-	mutex_lock(&event_mutex);
-	mutex_lock(&trace_types_lock);
-
-	ret = -EEXIST;
-	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
-		if (tr->name && strcmp(tr->name, name) == 0)
-			goto out_unlock;
-	}
-
 	ret = -ENOMEM;
 	tr = kzalloc(sizeof(*tr), GFP_KERNEL);
 	if (!tr)
-		goto out_unlock;
+		return ERR_PTR(ret);
 
 	tr->name = kstrdup(name, GFP_KERNEL);
 	if (!tr->name)
@@ -8432,53 +8736,106 @@
 	if (allocate_trace_buffers(tr, trace_buf_size) < 0)
 		goto out_free_tr;
 
-	tr->dir = tracefs_create_dir(name, trace_instance_dir);
-	if (!tr->dir)
+	if (ftrace_allocate_ftrace_ops(tr) < 0)
 		goto out_free_tr;
 
-	ret = event_trace_add_tracer(tr->dir, tr);
-	if (ret) {
-		tracefs_remove_recursive(tr->dir);
-		goto out_free_tr;
-	}
-
 	ftrace_init_trace_array(tr);
 
-	init_tracer_tracefs(tr, tr->dir);
 	init_trace_flags_index(tr);
-	__update_tracer_options(tr);
+
+	if (trace_instance_dir) {
+		ret = trace_array_create_dir(tr);
+		if (ret)
+			goto out_free_tr;
+	} else
+		__trace_early_add_events(tr);
 
 	list_add(&tr->list, &ftrace_trace_arrays);
 
-	mutex_unlock(&trace_types_lock);
-	mutex_unlock(&event_mutex);
+	tr->ref++;
 
 	return tr;
 
  out_free_tr:
+	ftrace_free_ftrace_ops(tr);
 	free_trace_buffers(tr);
 	free_cpumask_var(tr->tracing_cpumask);
 	kfree(tr->name);
 	kfree(tr);
 
- out_unlock:
-	mutex_unlock(&trace_types_lock);
-	mutex_unlock(&event_mutex);
-
 	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(trace_array_create);
 
 static int instance_mkdir(const char *name)
 {
-	return PTR_ERR_OR_ZERO(trace_array_create(name));
+	struct trace_array *tr;
+	int ret;
+
+	mutex_lock(&event_mutex);
+	mutex_lock(&trace_types_lock);
+
+	ret = -EEXIST;
+	if (trace_array_find(name))
+		goto out_unlock;
+
+	tr = trace_array_create(name);
+
+	ret = PTR_ERR_OR_ZERO(tr);
+
+out_unlock:
+	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
+	return ret;
 }
 
+/**
+ * trace_array_get_by_name - Create/Lookup a trace array, given its name.
+ * @name: The name of the trace array to be looked up/created.
+ *
+ * Returns pointer to trace array with given name.
+ * NULL, if it cannot be created.
+ *
+ * NOTE: This function increments the reference counter associated with the
+ * trace array returned. This makes sure it cannot be freed while in use.
+ * Use trace_array_put() once the trace array is no longer needed.
+ * If the trace_array is to be freed, trace_array_destroy() needs to
+ * be called after the trace_array_put(), or simply let user space delete
+ * it from the tracefs instances directory. But until the
+ * trace_array_put() is called, user space can not delete it.
+ *
+ */
+struct trace_array *trace_array_get_by_name(const char *name)
+{
+	struct trace_array *tr;
+
+	mutex_lock(&event_mutex);
+	mutex_lock(&trace_types_lock);
+
+	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+		if (tr->name && strcmp(tr->name, name) == 0)
+			goto out_unlock;
+	}
+
+	tr = trace_array_create(name);
+
+	if (IS_ERR(tr))
+		tr = NULL;
+out_unlock:
+	if (tr)
+		tr->ref++;
+
+	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
+	return tr;
+}
+EXPORT_SYMBOL_GPL(trace_array_get_by_name);
+
 static int __remove_instance(struct trace_array *tr)
 {
 	int i;
 
-	if (tr->ref || (tr->current_trace && tr->trace_ref))
+	/* Reference counter for a newly created trace array = 1. */
+	if (tr->ref > 1 || (tr->current_trace && tr->trace_ref))
 		return -EBUSY;
 
 	list_del(&tr->list);
@@ -8494,7 +8851,7 @@
 	event_trace_del_tracer(tr);
 	ftrace_clear_pids(tr);
 	ftrace_destroy_function_files(tr);
-	tracefs_remove_recursive(tr->dir);
+	tracefs_remove(tr->dir);
 	free_trace_buffers(tr);
 
 	for (i = 0; i < tr->nr_topts; i++) {
@@ -8505,7 +8862,6 @@
 	free_cpumask_var(tr->tracing_cpumask);
 	kfree(tr->name);
 	kfree(tr);
-	tr = NULL;
 
 	return 0;
 }
@@ -8547,12 +8903,9 @@
 	mutex_lock(&trace_types_lock);
 
 	ret = -ENODEV;
-	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
-		if (tr->name && strcmp(tr->name, name) == 0) {
-			ret = __remove_instance(tr);
-			break;
-		}
-	}
+	tr = trace_array_find(name);
+	if (tr)
+		ret = __remove_instance(tr);
 
 	mutex_unlock(&trace_types_lock);
 	mutex_unlock(&event_mutex);
@@ -8562,11 +8915,27 @@
 
 static __init void create_trace_instances(struct dentry *d_tracer)
 {
+	struct trace_array *tr;
+
 	trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer,
 							 instance_mkdir,
 							 instance_rmdir);
-	if (WARN_ON(!trace_instance_dir))
+	if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n"))
 		return;
+
+	mutex_lock(&event_mutex);
+	mutex_lock(&trace_types_lock);
+
+	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+		if (!tr->name)
+			continue;
+		if (MEM_FAIL(trace_array_create_dir(tr) < 0,
+			     "Failed to create instance directory\n"))
+			break;
+	}
+
+	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
 }
 
 static void
@@ -8631,12 +9000,11 @@
 	create_trace_options_dir(tr);
 
 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
-	trace_create_file("tracing_max_latency", 0644, d_tracer,
-			&tr->max_latency, &tracing_max_lat_fops);
+	trace_create_maxlat_file(tr, d_tracer);
 #endif
 
 	if (ftrace_create_function_files(tr, d_tracer))
-		WARN(1, "Could not allocate function filter files");
+		MEM_FAIL(1, "Could not allocate function filter files");
 
 #ifdef CONFIG_TRACER_SNAPSHOT
 	trace_create_file("snapshot", 0644, d_tracer,
@@ -8681,23 +9049,21 @@
  * directory. It is called via fs_initcall() by any of the boot up code
  * and expects to return the dentry of the top level tracing directory.
  */
-struct dentry *tracing_init_dentry(void)
+int tracing_init_dentry(void)
 {
 	struct trace_array *tr = &global_trace;
 
 	if (security_locked_down(LOCKDOWN_TRACEFS)) {
-		pr_warning("Tracing disabled due to lockdown\n");
-		return ERR_PTR(-EPERM);
+		pr_warn("Tracing disabled due to lockdown\n");
+		return -EPERM;
 	}
 
 	/* The top level trace array uses  NULL as parent */
 	if (tr->dir)
-		return NULL;
+		return 0;
 
-	if (WARN_ON(!tracefs_initialized()) ||
-		(IS_ENABLED(CONFIG_DEBUG_FS) &&
-		 WARN_ON(!debugfs_initialized())))
-		return ERR_PTR(-ENODEV);
+	if (WARN_ON(!tracefs_initialized()))
+		return -ENODEV;
 
 	/*
 	 * As there may still be users that expect the tracing
@@ -8708,7 +9074,7 @@
 	tr->dir = debugfs_create_automount("tracing", NULL,
 					   trace_automount, NULL);
 
-	return NULL;
+	return 0;
 }
 
 extern struct trace_eval_map *__start_ftrace_eval_maps[];
@@ -8784,7 +9150,7 @@
 		break;
 	}
 
-	return 0;
+	return NOTIFY_OK;
 }
 
 static struct notifier_block trace_module_nb = {
@@ -8795,48 +9161,48 @@
 
 static __init int tracer_init_tracefs(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
 	trace_access_lock_init();
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
 	event_trace_init();
 
-	init_tracer_tracefs(&global_trace, d_tracer);
-	ftrace_init_tracefs_toplevel(&global_trace, d_tracer);
+	init_tracer_tracefs(&global_trace, NULL);
+	ftrace_init_tracefs_toplevel(&global_trace, NULL);
 
-	trace_create_file("tracing_thresh", 0644, d_tracer,
+	trace_create_file("tracing_thresh", 0644, NULL,
 			&global_trace, &tracing_thresh_fops);
 
-	trace_create_file("README", 0444, d_tracer,
+	trace_create_file("README", 0444, NULL,
 			NULL, &tracing_readme_fops);
 
-	trace_create_file("saved_cmdlines", 0444, d_tracer,
+	trace_create_file("saved_cmdlines", 0444, NULL,
 			NULL, &tracing_saved_cmdlines_fops);
 
-	trace_create_file("saved_cmdlines_size", 0644, d_tracer,
+	trace_create_file("saved_cmdlines_size", 0644, NULL,
 			  NULL, &tracing_saved_cmdlines_size_fops);
 
-	trace_create_file("saved_tgids", 0444, d_tracer,
+	trace_create_file("saved_tgids", 0444, NULL,
 			NULL, &tracing_saved_tgids_fops);
 
 	trace_eval_init();
 
-	trace_create_eval_file(d_tracer);
+	trace_create_eval_file(NULL);
 
 #ifdef CONFIG_MODULES
 	register_module_notifier(&trace_module_nb);
 #endif
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-	trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
-			&ftrace_update_tot_cnt, &tracing_dyn_info_fops);
+	trace_create_file("dyn_ftrace_total_info", 0444, NULL,
+			NULL, &tracing_dyn_info_fops);
 #endif
 
-	create_trace_instances(d_tracer);
+	create_trace_instances(NULL);
 
 	update_tracer_options(&global_trace);
 
@@ -8918,13 +9284,13 @@
 	iter->tr = &global_trace;
 	iter->trace = iter->tr->current_trace;
 	iter->cpu_file = RING_BUFFER_ALL_CPUS;
-	iter->trace_buffer = &global_trace.trace_buffer;
+	iter->array_buffer = &global_trace.array_buffer;
 
 	if (iter->trace && iter->trace->open)
 		iter->trace->open(iter);
 
 	/* Annotate start of buffers if we had overruns */
-	if (ring_buffer_overruns(iter->trace_buffer->buffer))
+	if (ring_buffer_overruns(iter->array_buffer->buffer))
 		iter->iter_flags |= TRACE_FILE_ANNOTATE;
 
 	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
@@ -8963,9 +9329,12 @@
 
 	/* Simulate the iterator */
 	trace_init_global_iter(&iter);
+	/* Can not use kmalloc for iter.temp */
+	iter.temp = static_temp_buf;
+	iter.temp_size = STATIC_TEMP_BUF_SIZE;
 
 	for_each_tracing_cpu(cpu) {
-		atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
+		atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
 	}
 
 	old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ;
@@ -8996,7 +9365,7 @@
 	}
 
 	/*
-	 * We need to stop all tracing on all CPUS to read the
+	 * We need to stop all tracing on all CPUS to read
 	 * the next buffer. This is a bit expensive, but is
 	 * not done often. We fill all what we can read,
 	 * and then release the locks again.
@@ -9033,7 +9402,7 @@
 	tr->trace_flags |= old_userobj;
 
 	for_each_tracing_cpu(cpu) {
-		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
+		atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
 	}
 	atomic_dec(&dump_running);
 	printk_nmi_direct_exit();
@@ -9134,12 +9503,12 @@
 
 
 	if (security_locked_down(LOCKDOWN_TRACEFS)) {
-		pr_warning("Tracing disabled due to lockdown\n");
+		pr_warn("Tracing disabled due to lockdown\n");
 		return -EPERM;
 	}
 
 	/*
-	 * Make sure we don't accidently add more trace options
+	 * Make sure we don't accidentally add more trace options
 	 * than we have bits for.
 	 */
 	BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE);
@@ -9168,7 +9537,7 @@
 
 	/*
 	 * The prepare callbacks allocates some memory for the ring buffer. We
-	 * don't free the buffer if the if the CPU goes down. If we were to free
+	 * don't free the buffer if the CPU goes down. If we were to free
 	 * the buffer, then the user would lose any trace that was in the
 	 * buffer. The memory will be removed once the "instance" is removed.
 	 */
@@ -9188,8 +9557,7 @@
 
 	/* TODO: make the number of buffers hot pluggable with CPUS */
 	if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
-		printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
-		WARN_ON(1);
+		MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n");
 		goto out_free_savedcmd;
 	}
 
@@ -9262,7 +9630,8 @@
 	if (tracepoint_printk) {
 		tracepoint_print_iter =
 			kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
-		if (WARN_ON(!tracepoint_print_iter))
+		if (MEM_FAIL(!tracepoint_print_iter,
+			     "Failed to allocate trace iterator\n"))
 			tracepoint_printk = 0;
 		else
 			static_key_enable(&tracepoint_printk_key.key);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index fc3aa81..8d67f7f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -11,11 +11,15 @@
 #include <linux/mmiotrace.h>
 #include <linux/tracepoint.h>
 #include <linux/ftrace.h>
+#include <linux/trace.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/trace_seq.h>
 #include <linux/trace_events.h>
 #include <linux/compiler.h>
 #include <linux/glob.h>
+#include <linux/irq_work.h>
+#include <linux/workqueue.h>
+#include <linux/ctype.h>
 
 #ifdef CONFIG_FTRACE_SYSCALLS
 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
@@ -49,12 +53,18 @@
 #undef __field
 #define __field(type, item)		type	item;
 
+#undef __field_fn
+#define __field_fn(type, item)		type	item;
+
 #undef __field_struct
 #define __field_struct(type, item)	__field(type, item)
 
 #undef __field_desc
 #define __field_desc(type, container, item)
 
+#undef __field_packed
+#define __field_packed(type, container, item)
+
 #undef __array
 #define __array(type, item, size)	type	item[size];
 
@@ -68,29 +78,37 @@
 #define F_STRUCT(args...)		args
 
 #undef FTRACE_ENTRY
-#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
+#define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
 	struct struct_name {						\
 		struct trace_entry	ent;				\
 		tstruct							\
 	}
 
 #undef FTRACE_ENTRY_DUP
-#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
+#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
 
 #undef FTRACE_ENTRY_REG
-#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
-			 filter, regfn) \
-	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
+	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 #undef FTRACE_ENTRY_PACKED
-#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
-			    filter)					\
-	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter) __packed
+#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
+	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
 
 #include "trace_entries.h"
 
+/* Use this for memory failure errors */
+#define MEM_FAIL(condition, fmt, ...) ({			\
+	static bool __section(".data.once") __warned;		\
+	int __ret_warn_once = !!(condition);			\
+								\
+	if (unlikely(__ret_warn_once && !__warned)) {		\
+		__warned = true;				\
+		pr_err("ERROR: " fmt, ##__VA_ARGS__);		\
+	}							\
+	unlikely(__ret_warn_once);				\
+})
+
 /*
  * syscalls are special, and need special handling, this is why
  * they are not included in trace_entries.h
@@ -164,18 +182,18 @@
 	kuid_t			uid;
 	char			comm[TASK_COMM_LEN];
 
-	bool			ignore_pid;
 #ifdef CONFIG_FUNCTION_TRACER
-	bool			ftrace_ignore_pid;
+	int			ftrace_ignore_pid;
 #endif
+	bool			ignore_pid;
 };
 
 struct tracer;
 struct trace_option_dentry;
 
-struct trace_buffer {
+struct array_buffer {
 	struct trace_array		*tr;
-	struct ring_buffer		*buffer;
+	struct trace_buffer		*buffer;
 	struct trace_array_cpu __percpu	*data;
 	u64				time_start;
 	int				cpu;
@@ -193,6 +211,30 @@
 	unsigned long			*pids;
 };
 
+enum {
+	TRACE_PIDS		= BIT(0),
+	TRACE_NO_PIDS		= BIT(1),
+};
+
+static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
+				    struct trace_pid_list *no_pid_list)
+{
+	/* Return true if the pid list in type has pids */
+	return ((type & TRACE_PIDS) && pid_list) ||
+		((type & TRACE_NO_PIDS) && no_pid_list);
+}
+
+static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
+					 struct trace_pid_list *no_pid_list)
+{
+	/*
+	 * Turning off what is in @type, return true if the "other"
+	 * pid list, still has pids in it.
+	 */
+	return (!(type & TRACE_PIDS) && pid_list) ||
+		(!(type & TRACE_NO_PIDS) && no_pid_list);
+}
+
 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
 
 /**
@@ -205,7 +247,7 @@
  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
  * passed in turn to the cond_snapshot.update() function.  That data
  * can be compared by the update() implementation with the cond_data
- * contained wihin the struct cond_snapshot instance associated with
+ * contained within the struct cond_snapshot instance associated with
  * the trace_array.  Because the tr->max_lock is held throughout the
  * update() call, the update() function can directly retrieve the
  * cond_snapshot and cond_data associated with the per-instance
@@ -230,7 +272,7 @@
  *	take the snapshot, by returning 'true' if so, 'false' if no
  *	snapshot should be taken.  Because the max_lock is held for
  *	the duration of update(), the implementation is safe to
- *	directly retrieven and save any implementation data it needs
+ *	directly retrieved and save any implementation data it needs
  *	to in association with the snapshot.
  */
 struct cond_snapshot {
@@ -246,7 +288,7 @@
 struct trace_array {
 	struct list_head	list;
 	char			*name;
-	struct trace_buffer	trace_buffer;
+	struct array_buffer	array_buffer;
 #ifdef CONFIG_TRACER_MAX_TRACE
 	/*
 	 * The max_buffer is used to snapshot the trace when a maximum
@@ -254,18 +296,24 @@
 	 * Some tracers will use this to store a maximum trace while
 	 * it continues examining live traces.
 	 *
-	 * The buffers for the max_buffer are set up the same as the trace_buffer
+	 * The buffers for the max_buffer are set up the same as the array_buffer
 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
-	 * with the buffer of the trace_buffer and the buffers are reset for
-	 * the trace_buffer so the tracing can continue.
+	 * with the buffer of the array_buffer and the buffers are reset for
+	 * the array_buffer so the tracing can continue.
 	 */
-	struct trace_buffer	max_buffer;
+	struct array_buffer	max_buffer;
 	bool			allocated_snapshot;
 #endif
 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
 	unsigned long		max_latency;
+#ifdef CONFIG_FSNOTIFY
+	struct dentry		*d_max_latency;
+	struct work_struct	fsnotify_work;
+	struct irq_work		fsnotify_irqwork;
+#endif
 #endif
 	struct trace_pid_list	__rcu *filtered_pids;
+	struct trace_pid_list	__rcu *filtered_no_pids;
 	/*
 	 * max_lock is used to protect the swapping of buffers
 	 * when taking a max snapshot. The buffers themselves are
@@ -313,6 +361,7 @@
 #ifdef CONFIG_FUNCTION_TRACER
 	struct ftrace_ops	*ops;
 	struct trace_pid_list	__rcu *function_pids;
+	struct trace_pid_list	__rcu *function_no_pids;
 #ifdef CONFIG_DYNAMIC_FTRACE
 	/* All of these are protected by the ftrace_lock */
 	struct list_head	func_probes;
@@ -338,8 +387,9 @@
 extern struct mutex trace_types_lock;
 
 extern int trace_array_get(struct trace_array *tr);
-extern void trace_array_put(struct trace_array *tr);
 extern int tracing_check_open_get_tr(struct trace_array *tr);
+extern struct trace_array *trace_array_find(const char *instance);
+extern struct trace_array *trace_array_find_get(const char *instance);
 
 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
@@ -523,36 +573,21 @@
  *    then this function calls...
  *   The function callback, which can use the FTRACE bits to
  *    check for recursion.
- *
- * Now if the arch does not suppport a feature, and it calls
- * the global list function which calls the ftrace callback
- * all three of these steps will do a recursion protection.
- * There's no reason to do one if the previous caller already
- * did. The recursion that we are protecting against will
- * go through the same steps again.
- *
- * To prevent the multiple recursion checks, if a recursion
- * bit is set that is higher than the MAX bit of the current
- * check, then we know that the check was made by the previous
- * caller, and we can skip the current check.
  */
 enum {
-	TRACE_BUFFER_BIT,
-	TRACE_BUFFER_NMI_BIT,
-	TRACE_BUFFER_IRQ_BIT,
-	TRACE_BUFFER_SIRQ_BIT,
-
-	/* Start of function recursion bits */
+	/* Function recursion bits */
 	TRACE_FTRACE_BIT,
 	TRACE_FTRACE_NMI_BIT,
 	TRACE_FTRACE_IRQ_BIT,
 	TRACE_FTRACE_SIRQ_BIT,
+	TRACE_FTRACE_TRANSITION_BIT,
 
-	/* INTERNAL_BITs must be greater than FTRACE_BITs */
+	/* Internal use recursion bits */
 	TRACE_INTERNAL_BIT,
 	TRACE_INTERNAL_NMI_BIT,
 	TRACE_INTERNAL_IRQ_BIT,
 	TRACE_INTERNAL_SIRQ_BIT,
+	TRACE_INTERNAL_TRANSITION_BIT,
 
 	TRACE_BRANCH_BIT,
 /*
@@ -592,12 +627,6 @@
 	 * function is called to clear it.
 	 */
 	TRACE_GRAPH_NOTRACE_BIT,
-
-	/*
-	 * When transitioning between context, the preempt_count() may
-	 * not be correct. Allow for a single recursion to cover this case.
-	 */
-	TRACE_TRANSITION_BIT,
 };
 
 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
@@ -617,12 +646,18 @@
 #define TRACE_CONTEXT_BITS	4
 
 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
-#define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
 
 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
-#define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
 
-#define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
+#define TRACE_CONTEXT_MASK	((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
+
+enum {
+	TRACE_CTX_NMI,
+	TRACE_CTX_IRQ,
+	TRACE_CTX_SOFTIRQ,
+	TRACE_CTX_NORMAL,
+	TRACE_CTX_TRANSITION,
+};
 
 static __always_inline int trace_get_context_bit(void)
 {
@@ -630,59 +665,48 @@
 
 	if (in_interrupt()) {
 		if (in_nmi())
-			bit = 0;
+			bit = TRACE_CTX_NMI;
 
 		else if (in_irq())
-			bit = 1;
+			bit = TRACE_CTX_IRQ;
 		else
-			bit = 2;
+			bit = TRACE_CTX_SOFTIRQ;
 	} else
-		bit = 3;
+		bit = TRACE_CTX_NORMAL;
 
 	return bit;
 }
 
-static __always_inline int trace_test_and_set_recursion(int start, int max)
+static __always_inline int trace_test_and_set_recursion(int start)
 {
 	unsigned int val = current->trace_recursion;
 	int bit;
 
-	/* A previous recursion check was made */
-	if ((val & TRACE_CONTEXT_MASK) > max)
-		return 0;
-
 	bit = trace_get_context_bit() + start;
 	if (unlikely(val & (1 << bit))) {
 		/*
 		 * It could be that preempt_count has not been updated during
 		 * a switch between contexts. Allow for a single recursion.
 		 */
-		bit = TRACE_TRANSITION_BIT;
+		bit = start + TRACE_CTX_TRANSITION;
 		if (trace_recursion_test(bit))
 			return -1;
 		trace_recursion_set(bit);
 		barrier();
-		return bit + 1;
+		return bit;
 	}
 
-	/* Normal check passed, clear the transition to allow it again */
-	trace_recursion_clear(TRACE_TRANSITION_BIT);
-
 	val |= 1 << bit;
 	current->trace_recursion = val;
 	barrier();
 
-	return bit + 1;
+	return bit;
 }
 
 static __always_inline void trace_clear_recursion(int bit)
 {
 	unsigned int val = current->trace_recursion;
 
-	if (!bit)
-		return;
-
-	bit--;
 	bit = 1 << bit;
 	val &= ~bit;
 
@@ -698,7 +722,7 @@
 
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
-void tracing_reset_online_cpus(struct trace_buffer *buf);
+void tracing_reset_online_cpus(struct array_buffer *buf);
 void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
@@ -713,12 +737,12 @@
 				 void *data,
 				 const struct file_operations *fops);
 
-struct dentry *tracing_init_dentry(void);
+int tracing_init_dentry(void);
 
 struct ring_buffer_event;
 
 struct ring_buffer_event *
-trace_buffer_lock_reserve(struct ring_buffer *buffer,
+trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags,
@@ -730,7 +754,7 @@
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 					  int *ent_cpu, u64 *ent_ts);
 
-void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
+void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 					struct ring_buffer_event *event);
 
 int trace_empty(struct trace_iterator *iter);
@@ -787,6 +811,7 @@
 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
 			     pid_t search_pid);
 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
+			    struct trace_pid_list *filtered_no_pids,
 			    struct task_struct *task);
 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
 				  struct task_struct *self,
@@ -806,6 +831,17 @@
 			  struct task_struct *tsk, int cpu);
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
+#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
+	defined(CONFIG_FSNOTIFY)
+
+void latency_fsnotify(struct trace_array *tr);
+
+#else
+
+static inline void latency_fsnotify(struct trace_array *tr) { }
+
+#endif
+
 #ifdef CONFIG_STACKTRACE
 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 		   int pc);
@@ -824,6 +860,8 @@
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 extern unsigned long ftrace_update_tot_cnt;
+extern unsigned long ftrace_number_of_pages;
+extern unsigned long ftrace_number_of_groups;
 void ftrace_init_trace_array(struct trace_array *tr);
 #else
 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
@@ -837,6 +875,8 @@
 extern bool tracing_selftest_disabled;
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
+extern void __init disable_tracing_selftest(const char *reason);
+
 extern int trace_selftest_startup_function(struct tracer *trace,
 					   struct trace_array *tr);
 extern int trace_selftest_startup_function_graph(struct tracer *trace,
@@ -860,6 +900,9 @@
  */
 #define __tracer_data		__refdata
 #else
+static inline void __init disable_tracing_selftest(const char *reason)
+{
+}
 /* Tracers are seldom changed. Optimize when selftests are disabled. */
 #define __tracer_data		__read_mostly
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
@@ -873,9 +916,7 @@
 extern int
 trace_array_vprintk(struct trace_array *tr,
 		    unsigned long ip, const char *fmt, va_list args);
-int trace_array_printk(struct trace_array *tr,
-		       unsigned long ip, const char *fmt, ...);
-int trace_array_printk_buf(struct ring_buffer *buffer,
+int trace_array_printk_buf(struct trace_buffer *buffer,
 			   unsigned long ip, const char *fmt, ...);
 void trace_printk_seq(struct trace_seq *s);
 enum print_line_t print_trace_line(struct trace_iterator *iter);
@@ -1067,6 +1108,10 @@
 extern struct list_head ftrace_pids;
 
 #ifdef CONFIG_FUNCTION_TRACER
+
+#define FTRACE_PID_IGNORE	-1
+#define FTRACE_PID_TRACE	-2
+
 struct ftrace_func_command {
 	struct list_head	list;
 	char			*name;
@@ -1078,12 +1123,15 @@
 extern bool ftrace_filter_param __initdata;
 static inline int ftrace_trace_task(struct trace_array *tr)
 {
-	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
+	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
+		FTRACE_PID_IGNORE;
 }
 extern int ftrace_is_dead(void);
 int ftrace_create_function_files(struct trace_array *tr,
 				 struct dentry *parent);
 void ftrace_destroy_function_files(struct trace_array *tr);
+int ftrace_allocate_ftrace_ops(struct trace_array *tr);
+void ftrace_free_ftrace_ops(struct trace_array *tr);
 void ftrace_init_global_array_ops(struct trace_array *tr);
 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
 void ftrace_reset_array_ops(struct trace_array *tr);
@@ -1105,6 +1153,11 @@
 {
 	return 0;
 }
+static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
+{
+	return 0;
+}
+static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
 static inline __init void
 ftrace_init_global_array_ops(struct trace_array *tr) { }
@@ -1166,6 +1219,11 @@
 void ftrace_create_filter_files(struct ftrace_ops *ops,
 				struct dentry *parent);
 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
+
+extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
+			     int len, int reset);
+extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
+			      int len, int reset);
 #else
 struct ftrace_func_command;
 
@@ -1291,6 +1349,7 @@
 		C(IRQ_INFO,		"irq-info"),		\
 		C(MARKERS,		"markers"),		\
 		C(EVENT_FORK,		"event-fork"),		\
+		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
 		FUNCTION_FLAGS					\
 		FGRAPH_FLAGS					\
 		STACK_FLAGS					\
@@ -1388,17 +1447,17 @@
 };
 
 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
-				     struct ring_buffer *buffer,
+				     struct trace_buffer *buffer,
 				     struct ring_buffer_event *event);
 
 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
-				     struct ring_buffer *buffer,
+				     struct trace_buffer *buffer,
 				     struct ring_buffer_event *event,
 				     unsigned long flags, int pc,
 				     struct pt_regs *regs);
 
 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
-					      struct ring_buffer *buffer,
+					      struct trace_buffer *buffer,
 					      struct ring_buffer_event *event,
 					      unsigned long flags, int pc)
 {
@@ -1411,7 +1470,7 @@
 void trace_buffered_event_enable(void);
 
 static inline void
-__trace_event_discard_commit(struct ring_buffer *buffer,
+__trace_event_discard_commit(struct trace_buffer *buffer,
 			     struct ring_buffer_event *event)
 {
 	if (this_cpu_read(trace_buffered_event) == event) {
@@ -1425,7 +1484,7 @@
 /*
  * Helper function for event_trigger_unlock_commit{_regs}().
  * If there are event triggers attached to this event that requires
- * filtering against its fields, then they wil be called as the
+ * filtering against its fields, then they will be called as the
  * entry already holds the field information of the current event.
  *
  * It also checks if the event should be discarded or not.
@@ -1437,7 +1496,7 @@
  */
 static inline bool
 __event_trigger_test_discard(struct trace_event_file *file,
-			     struct ring_buffer *buffer,
+			     struct trace_buffer *buffer,
 			     struct ring_buffer_event *event,
 			     void *entry,
 			     enum event_trigger_type *tt)
@@ -1447,14 +1506,26 @@
 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
 		*tt = event_triggers_call(file, entry, event);
 
-	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
-	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
-	     !filter_match_preds(file->filter, entry))) {
-		__trace_event_discard_commit(buffer, event);
-		return true;
-	}
+	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
+				    EVENT_FILE_FL_FILTERED |
+				    EVENT_FILE_FL_PID_FILTER))))
+		return false;
+
+	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
+		goto discard;
+
+	if (file->flags & EVENT_FILE_FL_FILTERED &&
+	    !filter_match_preds(file->filter, entry))
+		goto discard;
+
+	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
+	    trace_event_ignore_this_pid(file))
+		goto discard;
 
 	return false;
+ discard:
+	__trace_event_discard_commit(buffer, event);
+	return true;
 }
 
 /**
@@ -1472,7 +1543,7 @@
  */
 static inline void
 event_trigger_unlock_commit(struct trace_event_file *file,
-			    struct ring_buffer *buffer,
+			    struct trace_buffer *buffer,
 			    struct ring_buffer_event *event,
 			    void *entry, unsigned long irq_flags, int pc)
 {
@@ -1503,7 +1574,7 @@
  */
 static inline void
 event_trigger_unlock_commit_regs(struct trace_event_file *file,
-				 struct ring_buffer *buffer,
+				 struct trace_buffer *buffer,
 				 struct ring_buffer_event *event,
 				 void *entry, unsigned long irq_flags, int pc,
 				 struct pt_regs *regs)
@@ -1604,6 +1675,7 @@
 extern int event_trace_init(void);
 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
 extern int event_trace_del_tracer(struct trace_array *tr);
+extern void __trace_early_add_events(struct trace_array *tr);
 
 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
 						  const char *system,
@@ -1622,6 +1694,8 @@
 
 extern const struct file_operations event_trigger_fops;
 extern const struct file_operations event_hist_fops;
+extern const struct file_operations event_hist_debug_fops;
+extern const struct file_operations event_inject_fops;
 
 #ifdef CONFIG_HIST_TRIGGERS
 extern int register_trigger_hist_cmd(void);
@@ -1909,11 +1983,19 @@
 extern const char *__stop___tracepoint_str[];
 
 void trace_printk_control(bool enabled);
-void trace_printk_init_buffers(void);
 void trace_printk_start_comm(void);
 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
 
+/* Used from boot time tracer */
+extern int trace_set_options(struct trace_array *tr, char *option);
+extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
+extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
+					  unsigned long size, int cpu_id);
+extern int tracing_set_cpumask(struct trace_array *tr,
+				cpumask_var_t tracing_cpumask_new);
+
+
 #define MAX_EVENT_NAME_LEN	64
 
 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
@@ -1938,17 +2020,15 @@
 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
 
 #undef FTRACE_ENTRY
-#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
+#define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
 	extern struct trace_event_call					\
 	__aligned(4) event_##call;
 #undef FTRACE_ENTRY_DUP
-#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
-	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
+	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 #undef FTRACE_ENTRY_PACKED
-#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
-	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
+	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 #include "trace_entries.h"
 
@@ -1973,6 +2053,9 @@
 #ifdef CONFIG_EVENT_TRACING
 void trace_event_init(void);
 void trace_event_eval_update(struct trace_eval_map **map, int len);
+/* Used from boot time tracer */
+extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
+extern int trigger_process_regex(struct trace_event_file *file, char *buff);
 #else
 static inline void __init trace_event_init(void) { }
 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
@@ -2024,4 +2107,16 @@
 	iter->pos = -1;
 }
 
+/* Check the name is good for event/group/fields */
+static inline bool is_good_name(const char *name)
+{
+	if (!isalpha(*name) && *name != '_')
+		return false;
+	while (*++name != '\0') {
+		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
+			return false;
+	}
+	return true;
+}
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c
index 80e0b2a..2e9a474 100644
--- a/kernel/trace/trace_benchmark.c
+++ b/kernel/trace/trace_benchmark.c
@@ -178,14 +178,14 @@
 int trace_benchmark_reg(void)
 {
 	if (!ok_to_run) {
-		pr_warning("trace benchmark cannot be started via kernel command line\n");
+		pr_warn("trace benchmark cannot be started via kernel command line\n");
 		return -EBUSY;
 	}
 
 	bm_event_thread = kthread_run(benchmark_event_kthread,
 				      NULL, "event_benchmark");
 	if (IS_ERR(bm_event_thread)) {
-		pr_warning("trace benchmark failed to create kernel thread\n");
+		pr_warn("trace benchmark failed to create kernel thread\n");
 		return PTR_ERR(bm_event_thread);
 	}
 
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
new file mode 100644
index 0000000..0996d59
--- /dev/null
+++ b/kernel/trace/trace_boot.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * trace_boot.c
+ * Tracing kernel boot-time
+ */
+
+#define pr_fmt(fmt)	"trace_boot: " fmt
+
+#include <linux/bootconfig.h>
+#include <linux/cpumask.h>
+#include <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/trace.h>
+#include <linux/trace_events.h>
+
+#include "trace.h"
+
+#define MAX_BUF_LEN 256
+
+static void __init
+trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *anode;
+	const char *p;
+	char buf[MAX_BUF_LEN];
+	unsigned long v = 0;
+
+	/* Common ftrace options */
+	xbc_node_for_each_array_value(node, "options", anode, p) {
+		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+			pr_err("String is too long: %s\n", p);
+			continue;
+		}
+
+		if (trace_set_options(tr, buf) < 0)
+			pr_err("Failed to set option: %s\n", buf);
+	}
+
+	p = xbc_node_find_value(node, "tracing_on", NULL);
+	if (p && *p != '\0') {
+		if (kstrtoul(p, 10, &v))
+			pr_err("Failed to set tracing on: %s\n", p);
+		if (v)
+			tracer_tracing_on(tr);
+		else
+			tracer_tracing_off(tr);
+	}
+
+	p = xbc_node_find_value(node, "trace_clock", NULL);
+	if (p && *p != '\0') {
+		if (tracing_set_clock(tr, p) < 0)
+			pr_err("Failed to set trace clock: %s\n", p);
+	}
+
+	p = xbc_node_find_value(node, "buffer_size", NULL);
+	if (p && *p != '\0') {
+		v = memparse(p, NULL);
+		if (v < PAGE_SIZE)
+			pr_err("Buffer size is too small: %s\n", p);
+		if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
+			pr_err("Failed to resize trace buffer to %s\n", p);
+	}
+
+	p = xbc_node_find_value(node, "cpumask", NULL);
+	if (p && *p != '\0') {
+		cpumask_var_t new_mask;
+
+		if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
+			if (cpumask_parse(p, new_mask) < 0 ||
+			    tracing_set_cpumask(tr, new_mask) < 0)
+				pr_err("Failed to set new CPU mask %s\n", p);
+			free_cpumask_var(new_mask);
+		}
+	}
+}
+
+#ifdef CONFIG_EVENT_TRACING
+static void __init
+trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *p;
+
+	xbc_node_for_each_array_value(node, "events", anode, p) {
+		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+			pr_err("String is too long: %s\n", p);
+			continue;
+		}
+
+		if (ftrace_set_clr_event(tr, buf, 1) < 0)
+			pr_err("Failed to enable event: %s\n", p);
+	}
+}
+
+#ifdef CONFIG_KPROBE_EVENTS
+static int __init
+trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
+{
+	struct dynevent_cmd cmd;
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *val;
+	int ret = 0;
+
+	xbc_node_for_each_array_value(node, "probes", anode, val) {
+		kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+
+		ret = kprobe_event_gen_cmd_start(&cmd, event, val);
+		if (ret) {
+			pr_err("Failed to generate probe: %s\n", buf);
+			break;
+		}
+
+		ret = kprobe_event_gen_cmd_end(&cmd);
+		if (ret) {
+			pr_err("Failed to add probe: %s\n", buf);
+			break;
+		}
+	}
+
+	return ret;
+}
+#else
+static inline int __init
+trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
+{
+	pr_err("Kprobe event is not supported.\n");
+	return -ENOTSUPP;
+}
+#endif
+
+#ifdef CONFIG_SYNTH_EVENTS
+static int __init
+trace_boot_add_synth_event(struct xbc_node *node, const char *event)
+{
+	struct dynevent_cmd cmd;
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *p;
+	int ret;
+
+	synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+
+	ret = synth_event_gen_cmd_start(&cmd, event, NULL);
+	if (ret)
+		return ret;
+
+	xbc_node_for_each_array_value(node, "fields", anode, p) {
+		ret = synth_event_add_field_str(&cmd, p);
+		if (ret)
+			return ret;
+	}
+
+	ret = synth_event_gen_cmd_end(&cmd);
+	if (ret < 0)
+		pr_err("Failed to add synthetic event: %s\n", buf);
+
+	return ret;
+}
+#else
+static inline int __init
+trace_boot_add_synth_event(struct xbc_node *node, const char *event)
+{
+	pr_err("Synthetic event is not supported.\n");
+	return -ENOTSUPP;
+}
+#endif
+
+static void __init
+trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
+			  struct xbc_node *enode)
+{
+	struct trace_event_file *file;
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *p, *group, *event;
+
+	group = xbc_node_get_data(gnode);
+	event = xbc_node_get_data(enode);
+
+	if (!strcmp(group, "kprobes"))
+		if (trace_boot_add_kprobe_event(enode, event) < 0)
+			return;
+	if (!strcmp(group, "synthetic"))
+		if (trace_boot_add_synth_event(enode, event) < 0)
+			return;
+
+	mutex_lock(&event_mutex);
+	file = find_event_file(tr, group, event);
+	if (!file) {
+		pr_err("Failed to find event: %s:%s\n", group, event);
+		goto out;
+	}
+
+	p = xbc_node_find_value(enode, "filter", NULL);
+	if (p && *p != '\0') {
+		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+			pr_err("filter string is too long: %s\n", p);
+		else if (apply_event_filter(file, buf) < 0)
+			pr_err("Failed to apply filter: %s\n", buf);
+	}
+
+	if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) {
+		xbc_node_for_each_array_value(enode, "actions", anode, p) {
+			if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+				pr_err("action string is too long: %s\n", p);
+			else if (trigger_process_regex(file, buf) < 0)
+				pr_err("Failed to apply an action: %s\n", buf);
+		}
+	} else if (xbc_node_find_value(enode, "actions", NULL))
+		pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n");
+
+	if (xbc_node_find_value(enode, "enable", NULL)) {
+		if (trace_event_enable_disable(file, 1, 0) < 0)
+			pr_err("Failed to enable event node: %s:%s\n",
+				group, event);
+	}
+out:
+	mutex_unlock(&event_mutex);
+}
+
+static void __init
+trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *gnode, *enode;
+
+	node = xbc_node_find_child(node, "event");
+	if (!node)
+		return;
+	/* per-event key starts with "event.GROUP.EVENT" */
+	xbc_node_for_each_child(node, gnode)
+		xbc_node_for_each_child(gnode, enode)
+			trace_boot_init_one_event(tr, gnode, enode);
+}
+#else
+#define trace_boot_enable_events(tr, node) do {} while (0)
+#define trace_boot_init_events(tr, node) do {} while (0)
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void __init
+trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *anode;
+	const char *p;
+	char *q;
+
+	xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
+		q = kstrdup(p, GFP_KERNEL);
+		if (!q)
+			return;
+		if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
+			pr_err("Failed to add %s to ftrace filter\n", p);
+		else
+			ftrace_filter_param = true;
+		kfree(q);
+	}
+	xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
+		q = kstrdup(p, GFP_KERNEL);
+		if (!q)
+			return;
+		if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
+			pr_err("Failed to add %s to ftrace filter\n", p);
+		else
+			ftrace_filter_param = true;
+		kfree(q);
+	}
+}
+#else
+#define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
+#endif
+
+static void __init
+trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
+{
+	const char *p;
+
+	trace_boot_set_ftrace_filter(tr, node);
+
+	p = xbc_node_find_value(node, "tracer", NULL);
+	if (p && *p != '\0') {
+		if (tracing_set_tracer(tr, p) < 0)
+			pr_err("Failed to set given tracer: %s\n", p);
+	}
+
+	/* Since tracer can free snapshot buffer, allocate snapshot here.*/
+	if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
+		if (tracing_alloc_snapshot_instance(tr) < 0)
+			pr_err("Failed to allocate snapshot buffer\n");
+	}
+}
+
+static void __init
+trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
+{
+	trace_boot_set_instance_options(tr, node);
+	trace_boot_init_events(tr, node);
+	trace_boot_enable_events(tr, node);
+	trace_boot_enable_tracer(tr, node);
+}
+
+static void __init
+trace_boot_init_instances(struct xbc_node *node)
+{
+	struct xbc_node *inode;
+	struct trace_array *tr;
+	const char *p;
+
+	node = xbc_node_find_child(node, "instance");
+	if (!node)
+		return;
+
+	xbc_node_for_each_child(node, inode) {
+		p = xbc_node_get_data(inode);
+		if (!p || *p == '\0')
+			continue;
+
+		tr = trace_array_get_by_name(p);
+		if (!tr) {
+			pr_err("Failed to get trace instance %s\n", p);
+			continue;
+		}
+		trace_boot_init_one_instance(tr, inode);
+		trace_array_put(tr);
+	}
+}
+
+static int __init trace_boot_init(void)
+{
+	struct xbc_node *trace_node;
+	struct trace_array *tr;
+
+	trace_node = xbc_find_node("ftrace");
+	if (!trace_node)
+		return 0;
+
+	tr = top_trace_array();
+	if (!tr)
+		return 0;
+
+	/* Global trace array is also one instance */
+	trace_boot_init_one_instance(tr, trace_node);
+	trace_boot_init_instances(trace_node);
+
+	disable_tracing_selftest("running boot-time tracing");
+
+	return 0;
+}
+/*
+ * Start tracing at the end of core-initcall, so that it starts tracing
+ * from the beginning of postcore_initcall.
+ */
+core_initcall_sync(trace_boot_init);
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 3ea65cd..eff0991 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -32,10 +32,10 @@
 {
 	struct trace_event_call *call = &event_branch;
 	struct trace_array *tr = branch_tracer;
+	struct trace_buffer *buffer;
 	struct trace_array_cpu *data;
 	struct ring_buffer_event *event;
 	struct trace_branch *entry;
-	struct ring_buffer *buffer;
 	unsigned long flags;
 	int pc;
 	const char *p;
@@ -55,12 +55,12 @@
 
 	raw_local_irq_save(flags);
 	current->trace_recursion |= TRACE_BRANCH_BIT;
-	data = this_cpu_ptr(tr->trace_buffer.data);
+	data = this_cpu_ptr(tr->array_buffer.data);
 	if (atomic_read(&data->disabled))
 		goto out;
 
 	pc = preempt_count();
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH,
 					  sizeof(*entry), flags, pc);
 	if (!event)
@@ -244,7 +244,7 @@
 	return 0;
 }
 
-static inline long get_incorrect_percent(struct ftrace_branch_data *p)
+static inline long get_incorrect_percent(const struct ftrace_branch_data *p)
 {
 	long percent;
 
@@ -332,10 +332,10 @@
 	return p;
 }
 
-static int annotated_branch_stat_cmp(void *p1, void *p2)
+static int annotated_branch_stat_cmp(const void *p1, const void *p2)
 {
-	struct ftrace_branch_data *a = p1;
-	struct ftrace_branch_data *b = p2;
+	const struct ftrace_branch_data *a = p1;
+	const struct ftrace_branch_data *b = p2;
 
 	long percent_a, percent_b;
 
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 89779eb..5fa49cf 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -206,14 +206,14 @@
 /* Make a tracefs interface for controlling dynamic events */
 static __init int init_dynamic_event(void)
 {
-	struct dentry *d_tracer;
 	struct dentry *entry;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	entry = tracefs_create_file("dynamic_events", 0644, d_tracer,
+	entry = tracefs_create_file("dynamic_events", 0644, NULL,
 				    NULL, &dynamic_events_ops);
 
 	/* Event list interface */
@@ -223,3 +223,215 @@
 	return 0;
 }
 fs_initcall(init_dynamic_event);
+
+/**
+ * dynevent_arg_add - Add an arg to a dynevent_cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event cmd
+ * @arg: The argument to append to the current cmd
+ * @check_arg: An (optional) pointer to a function checking arg sanity
+ *
+ * Append an argument to a dynevent_cmd.  The argument string will be
+ * appended to the current cmd string, followed by a separator, if
+ * applicable.  Before the argument is added, the @check_arg function,
+ * if present, will be used to check the sanity of the current arg
+ * string.
+ *
+ * The cmd string and separator should be set using the
+ * dynevent_arg_init() before any arguments are added using this
+ * function.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int dynevent_arg_add(struct dynevent_cmd *cmd,
+		     struct dynevent_arg *arg,
+		     dynevent_check_arg_fn_t check_arg)
+{
+	int ret = 0;
+
+	if (check_arg) {
+		ret = check_arg(arg);
+		if (ret)
+			return ret;
+	}
+
+	ret = seq_buf_printf(&cmd->seq, " %s%c", arg->str, arg->separator);
+	if (ret) {
+		pr_err("String is too long: %s%c\n", arg->str, arg->separator);
+		return -E2BIG;
+	}
+
+	return ret;
+}
+
+/**
+ * dynevent_arg_pair_add - Add an arg pair to a dynevent_cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event cmd
+ * @arg_pair: The argument pair to append to the current cmd
+ * @check_arg: An (optional) pointer to a function checking arg sanity
+ *
+ * Append an argument pair to a dynevent_cmd.  An argument pair
+ * consists of a left-hand-side argument and a right-hand-side
+ * argument separated by an operator, which can be whitespace, all
+ * followed by a separator, if applicable.  This can be used to add
+ * arguments of the form 'type variable_name;' or 'x+y'.
+ *
+ * The lhs argument string will be appended to the current cmd string,
+ * followed by an operator, if applicable, followd by the rhs string,
+ * followed finally by a separator, if applicable.  Before the
+ * argument is added, the @check_arg function, if present, will be
+ * used to check the sanity of the current arg strings.
+ *
+ * The cmd strings, operator, and separator should be set using the
+ * dynevent_arg_pair_init() before any arguments are added using this
+ * function.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
+			  struct dynevent_arg_pair *arg_pair,
+			  dynevent_check_arg_fn_t check_arg)
+{
+	int ret = 0;
+
+	if (check_arg) {
+		ret = check_arg(arg_pair);
+		if (ret)
+			return ret;
+	}
+
+	ret = seq_buf_printf(&cmd->seq, " %s%c%s%c", arg_pair->lhs,
+			     arg_pair->operator, arg_pair->rhs,
+			     arg_pair->separator);
+	if (ret) {
+		pr_err("field string is too long: %s%c%s%c\n", arg_pair->lhs,
+		       arg_pair->operator, arg_pair->rhs,
+		       arg_pair->separator);
+		return -E2BIG;
+	}
+
+	return ret;
+}
+
+/**
+ * dynevent_str_add - Add a string to a dynevent_cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event cmd
+ * @str: The string to append to the current cmd
+ *
+ * Append a string to a dynevent_cmd.  The string will be appended to
+ * the current cmd string as-is, with nothing prepended or appended.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int dynevent_str_add(struct dynevent_cmd *cmd, const char *str)
+{
+	int ret = 0;
+
+	ret = seq_buf_puts(&cmd->seq, str);
+	if (ret) {
+		pr_err("String is too long: %s\n", str);
+		return -E2BIG;
+	}
+
+	return ret;
+}
+
+/**
+ * dynevent_cmd_init - Initialize a dynevent_cmd object
+ * @cmd: A pointer to the dynevent_cmd struct representing the cmd
+ * @buf: A pointer to the buffer to generate the command into
+ * @maxlen: The length of the buffer the command will be generated into
+ * @type: The type of the cmd, checked against further operations
+ * @run_command: The type-specific function that will actually run the command
+ *
+ * Initialize a dynevent_cmd.  A dynevent_cmd is used to build up and
+ * run dynamic event creation commands, such as commands for creating
+ * synthetic and kprobe events.  Before calling any of the functions
+ * used to build the command, a dynevent_cmd object should be
+ * instantiated and initialized using this function.
+ *
+ * The initialization sets things up by saving a pointer to the
+ * user-supplied buffer and its length via the @buf and @maxlen
+ * params, and by saving the cmd-specific @type and @run_command
+ * params which are used to check subsequent dynevent_cmd operations
+ * and actually run the command when complete.
+ */
+void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen,
+		       enum dynevent_type type,
+		       dynevent_create_fn_t run_command)
+{
+	memset(cmd, '\0', sizeof(*cmd));
+
+	seq_buf_init(&cmd->seq, buf, maxlen);
+	cmd->type = type;
+	cmd->run_command = run_command;
+}
+
+/**
+ * dynevent_arg_init - Initialize a dynevent_arg object
+ * @arg: A pointer to the dynevent_arg struct representing the arg
+ * @separator: An (optional) separator, appended after adding the arg
+ *
+ * Initialize a dynevent_arg object.  A dynevent_arg represents an
+ * object used to append single arguments to the current command
+ * string.  After the arg string is successfully appended to the
+ * command string, the optional @separator is appended.  If no
+ * separator was specified when initializing the arg, a space will be
+ * appended.
+ */
+void dynevent_arg_init(struct dynevent_arg *arg,
+		       char separator)
+{
+	memset(arg, '\0', sizeof(*arg));
+
+	if (!separator)
+		separator = ' ';
+	arg->separator = separator;
+}
+
+/**
+ * dynevent_arg_pair_init - Initialize a dynevent_arg_pair object
+ * @arg_pair: A pointer to the dynevent_arg_pair struct representing the arg
+ * @operator: An (optional) operator, appended after adding the first arg
+ * @separator: An (optional) separator, appended after adding the second arg
+ *
+ * Initialize a dynevent_arg_pair object.  A dynevent_arg_pair
+ * represents an object used to append argument pairs such as 'type
+ * variable_name;' or 'x+y' to the current command string.  An
+ * argument pair consists of a left-hand-side argument and a
+ * right-hand-side argument separated by an operator, which can be
+ * whitespace, all followed by a separator, if applicable.  After the
+ * first arg string is successfully appended to the command string,
+ * the optional @operator is appended, followed by the second arg and
+ * optional @separator.  If no separator was specified when
+ * initializing the arg, a space will be appended.
+ */
+void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair,
+			    char operator, char separator)
+{
+	memset(arg_pair, '\0', sizeof(*arg_pair));
+
+	if (!operator)
+		operator = ' ';
+	arg_pair->operator = operator;
+
+	if (!separator)
+		separator = ' ';
+	arg_pair->separator = separator;
+}
+
+/**
+ * dynevent_create - Create the dynamic event contained in dynevent_cmd
+ * @cmd: The dynevent_cmd object containing the dynamic event creation command
+ *
+ * Once a dynevent_cmd object has been successfully built up via the
+ * dynevent_cmd_init(), dynevent_arg_add() and dynevent_arg_pair_add()
+ * functions, this function runs the final command to actually create
+ * the event.
+ *
+ * Return: 0 if the event was successfully created, error otherwise.
+ */
+int dynevent_create(struct dynevent_cmd *cmd)
+{
+	return cmd->run_command(cmd);
+}
+EXPORT_SYMBOL_GPL(dynevent_create);
diff --git a/kernel/trace/trace_dynevent.h b/kernel/trace/trace_dynevent.h
index 4689813..d6857a2 100644
--- a/kernel/trace/trace_dynevent.h
+++ b/kernel/trace/trace_dynevent.h
@@ -117,4 +117,36 @@
 #define for_each_dyn_event_safe(pos, n)	\
 	list_for_each_entry_safe(pos, n, &dyn_event_list, list)
 
+extern void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen,
+			      enum dynevent_type type,
+			      dynevent_create_fn_t run_command);
+
+typedef int (*dynevent_check_arg_fn_t)(void *data);
+
+struct dynevent_arg {
+	const char		*str;
+	char			separator; /* e.g. ';', ',', or nothing */
+};
+
+extern void dynevent_arg_init(struct dynevent_arg *arg,
+			      char separator);
+extern int dynevent_arg_add(struct dynevent_cmd *cmd,
+			    struct dynevent_arg *arg,
+			    dynevent_check_arg_fn_t check_arg);
+
+struct dynevent_arg_pair {
+	const char		*lhs;
+	const char		*rhs;
+	char			operator; /* e.g. '=' or nothing */
+	char			separator; /* e.g. ';', ',', or nothing */
+};
+
+extern void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair,
+				   char operator, char separator);
+
+extern int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
+				 struct dynevent_arg_pair *arg_pair,
+				 dynevent_check_arg_fn_t check_arg);
+extern int dynevent_str_add(struct dynevent_cmd *cmd, const char *str);
+
 #endif
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index 78c146e..18c4a58 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -61,15 +61,13 @@
 	TRACE_FN,
 
 	F_STRUCT(
-		__field(	unsigned long,	ip		)
-		__field(	unsigned long,	parent_ip	)
+		__field_fn(	unsigned long,	ip		)
+		__field_fn(	unsigned long,	parent_ip	)
 	),
 
 	F_printk(" %ps <-- %ps",
 		 (void *)__entry->ip, (void *)__entry->parent_ip),
 
-	FILTER_TRACE_FN,
-
 	perf_ftrace_event_register
 );
 
@@ -80,13 +78,11 @@
 
 	F_STRUCT(
 		__field_struct(	struct ftrace_graph_ent,	graph_ent	)
-		__field_desc(	unsigned long,	graph_ent,	func		)
-		__field_desc(	int,		graph_ent,	depth		)
+		__field_packed(	unsigned long,	graph_ent,	func		)
+		__field_packed(	int,		graph_ent,	depth		)
 	),
 
-	F_printk("--> %ps (%d)", (void *)__entry->func, __entry->depth),
-
-	FILTER_OTHER
+	F_printk("--> %ps (%d)", (void *)__entry->func, __entry->depth)
 );
 
 /* Function return entry */
@@ -96,19 +92,17 @@
 
 	F_STRUCT(
 		__field_struct(	struct ftrace_graph_ret,	ret	)
-		__field_desc(	unsigned long,	ret,		func	)
-		__field_desc(	unsigned long long, ret,	calltime)
-		__field_desc(	unsigned long long, ret,	rettime	)
-		__field_desc(	unsigned long,	ret,		overrun	)
-		__field_desc(	int,		ret,		depth	)
+		__field_packed(	unsigned long,	ret,		func	)
+		__field_packed(	unsigned long,	ret,		overrun	)
+		__field_packed(	unsigned long long, ret,	calltime)
+		__field_packed(	unsigned long long, ret,	rettime	)
+		__field_packed(	int,		ret,		depth	)
 	),
 
 	F_printk("<-- %ps (%d) (start: %llx  end: %llx) over: %d",
 		 (void *)__entry->func, __entry->depth,
 		 __entry->calltime, __entry->rettime,
-		 __entry->depth),
-
-	FILTER_OTHER
+		 __entry->depth)
 );
 
 /*
@@ -137,9 +131,7 @@
 	F_printk("%u:%u:%u  ==> %u:%u:%u [%03u]",
 		 __entry->prev_pid, __entry->prev_prio, __entry->prev_state,
 		 __entry->next_pid, __entry->next_prio, __entry->next_state,
-		 __entry->next_cpu),
-
-	FILTER_OTHER
+		 __entry->next_cpu)
 );
 
 /*
@@ -157,9 +149,7 @@
 	F_printk("%u:%u:%u  ==+ %u:%u:%u [%03u]",
 		 __entry->prev_pid, __entry->prev_prio, __entry->prev_state,
 		 __entry->next_pid, __entry->next_prio, __entry->next_state,
-		 __entry->next_cpu),
-
-	FILTER_OTHER
+		 __entry->next_cpu)
 );
 
 /*
@@ -183,9 +173,7 @@
 		 (void *)__entry->caller[0], (void *)__entry->caller[1],
 		 (void *)__entry->caller[2], (void *)__entry->caller[3],
 		 (void *)__entry->caller[4], (void *)__entry->caller[5],
-		 (void *)__entry->caller[6], (void *)__entry->caller[7]),
-
-	FILTER_OTHER
+		 (void *)__entry->caller[6], (void *)__entry->caller[7])
 );
 
 FTRACE_ENTRY(user_stack, userstack_entry,
@@ -203,9 +191,7 @@
 		 (void *)__entry->caller[0], (void *)__entry->caller[1],
 		 (void *)__entry->caller[2], (void *)__entry->caller[3],
 		 (void *)__entry->caller[4], (void *)__entry->caller[5],
-		 (void *)__entry->caller[6], (void *)__entry->caller[7]),
-
-	FILTER_OTHER
+		 (void *)__entry->caller[6], (void *)__entry->caller[7])
 );
 
 /*
@@ -222,9 +208,7 @@
 	),
 
 	F_printk("%ps: %s",
-		 (void *)__entry->ip, __entry->fmt),
-
-	FILTER_OTHER
+		 (void *)__entry->ip, __entry->fmt)
 );
 
 FTRACE_ENTRY_REG(print, print_entry,
@@ -239,8 +223,6 @@
 	F_printk("%ps: %s",
 		 (void *)__entry->ip, __entry->buf),
 
-	FILTER_OTHER,
-
 	ftrace_event_register
 );
 
@@ -254,9 +236,7 @@
 	),
 
 	F_printk("id:%04x %08x",
-		 __entry->id, (int)__entry->buf[0]),
-
-	FILTER_OTHER
+		 __entry->id, (int)__entry->buf[0])
 );
 
 FTRACE_ENTRY(bputs, bputs_entry,
@@ -269,9 +249,7 @@
 	),
 
 	F_printk("%ps: %s",
-		 (void *)__entry->ip, __entry->str),
-
-	FILTER_OTHER
+		 (void *)__entry->ip, __entry->str)
 );
 
 FTRACE_ENTRY(mmiotrace_rw, trace_mmiotrace_rw,
@@ -283,16 +261,14 @@
 		__field_desc(	resource_size_t, rw,	phys	)
 		__field_desc(	unsigned long,	rw,	value	)
 		__field_desc(	unsigned long,	rw,	pc	)
-		__field_desc(	int, 		rw,	map_id	)
+		__field_desc(	int,		rw,	map_id	)
 		__field_desc(	unsigned char,	rw,	opcode	)
 		__field_desc(	unsigned char,	rw,	width	)
 	),
 
 	F_printk("%lx %lx %lx %d %x %x",
 		 (unsigned long)__entry->phys, __entry->value, __entry->pc,
-		 __entry->map_id, __entry->opcode, __entry->width),
-
-	FILTER_OTHER
+		 __entry->map_id, __entry->opcode, __entry->width)
 );
 
 FTRACE_ENTRY(mmiotrace_map, trace_mmiotrace_map,
@@ -304,15 +280,13 @@
 		__field_desc(	resource_size_t, map,	phys	)
 		__field_desc(	unsigned long,	map,	virt	)
 		__field_desc(	unsigned long,	map,	len	)
-		__field_desc(	int, 		map,	map_id	)
+		__field_desc(	int,		map,	map_id	)
 		__field_desc(	unsigned char,	map,	opcode	)
 	),
 
 	F_printk("%lx %lx %lx %d %x",
 		 (unsigned long)__entry->phys, __entry->virt, __entry->len,
-		 __entry->map_id, __entry->opcode),
-
-	FILTER_OTHER
+		 __entry->map_id, __entry->opcode)
 );
 
 
@@ -334,9 +308,7 @@
 	F_printk("%u:%s:%s (%u)%s",
 		 __entry->line,
 		 __entry->func, __entry->file, __entry->correct,
-		 __entry->constant ? " CONSTANT" : ""),
-
-	FILTER_OTHER
+		 __entry->constant ? " CONSTANT" : "")
 );
 
 
@@ -353,16 +325,16 @@
 		__field_desc(	long,	timestamp,	tv_nsec		)
 		__field(	unsigned int,		nmi_count	)
 		__field(	unsigned int,		seqnum		)
+		__field(	unsigned int,		count		)
 	),
 
-	F_printk("cnt:%u\tts:%010llu.%010lu\tinner:%llu\touter:%llu\tnmi-ts:%llu\tnmi-count:%u\n",
+	F_printk("cnt:%u\tts:%010llu.%010lu\tinner:%llu\touter:%llu\tcount:%d\tnmi-ts:%llu\tnmi-count:%u\n",
 		 __entry->seqnum,
 		 __entry->tv_sec,
 		 __entry->tv_nsec,
 		 __entry->duration,
 		 __entry->outer_duration,
+		 __entry->count,
 		 __entry->nmi_total_ts,
-		 __entry->nmi_count),
-
-	FILTER_OTHER
+		 __entry->nmi_count)
 );
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index a9dfa04..643e0b1 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -8,6 +8,7 @@
 
 #include <linux/module.h>
 #include <linux/kprobes.h>
+#include <linux/security.h>
 #include "trace.h"
 #include "trace_probe.h"
 
@@ -26,8 +27,10 @@
 static int perf_trace_event_perm(struct trace_event_call *tp_event,
 				 struct perf_event *p_event)
 {
+	int ret;
+
 	if (tp_event->perf_perm) {
-		int ret = tp_event->perf_perm(tp_event, p_event);
+		ret = tp_event->perf_perm(tp_event, p_event);
 		if (ret)
 			return ret;
 	}
@@ -46,8 +49,9 @@
 
 	/* The ftrace function trace is allowed only for root. */
 	if (ftrace_event_is_function(tp_event)) {
-		if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
-			return -EPERM;
+		ret = perf_allow_tracepoint(&p_event->attr);
+		if (ret)
+			return ret;
 
 		if (!is_sampling_event(p_event))
 			return 0;
@@ -82,8 +86,9 @@
 	 * ...otherwise raw tracepoint data can be a severe data leak,
 	 * only allow root to have these.
 	 */
-	if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
-		return -EPERM;
+	ret = perf_allow_tracepoint(&p_event->attr);
+	if (ret)
+		return ret;
 
 	return 0;
 }
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index e31ee32..7cc5f0a 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -24,6 +24,7 @@
 #include <linux/delay.h>
 
 #include <trace/events/sched.h>
+#include <trace/syscall.h>
 
 #include <asm/setup.h>
 
@@ -37,6 +38,7 @@
 LIST_HEAD(ftrace_events);
 static LIST_HEAD(ftrace_generic_fields);
 static LIST_HEAD(ftrace_common_fields);
+static bool eventdir_initialized;
 
 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
 
@@ -231,13 +233,16 @@
 {
 	struct trace_array *tr = trace_file->tr;
 	struct trace_array_cpu *data;
+	struct trace_pid_list *no_pid_list;
 	struct trace_pid_list *pid_list;
 
 	pid_list = rcu_dereference_raw(tr->filtered_pids);
-	if (!pid_list)
+	no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
+
+	if (!pid_list && !no_pid_list)
 		return false;
 
-	data = this_cpu_ptr(tr->trace_buffer.data);
+	data = this_cpu_ptr(tr->array_buffer.data);
 
 	return data->ignore_pid;
 }
@@ -272,6 +277,7 @@
 	if (!fbuffer->event)
 		return NULL;
 
+	fbuffer->regs = NULL;
 	fbuffer->entry = ring_buffer_event_data(fbuffer->event);
 	return fbuffer->entry;
 }
@@ -508,6 +514,9 @@
 
 	pid_list = rcu_dereference_raw(tr->filtered_pids);
 	trace_filter_add_remove_task(pid_list, NULL, task);
+
+	pid_list = rcu_dereference_raw(tr->filtered_no_pids);
+	trace_filter_add_remove_task(pid_list, NULL, task);
 }
 
 static void
@@ -520,6 +529,9 @@
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
 	trace_filter_add_remove_task(pid_list, self, task);
+
+	pid_list = rcu_dereference_sched(tr->filtered_no_pids);
+	trace_filter_add_remove_task(pid_list, self, task);
 }
 
 void trace_event_follow_fork(struct trace_array *tr, bool enable)
@@ -542,13 +554,23 @@
 		    struct task_struct *prev, struct task_struct *next)
 {
 	struct trace_array *tr = data;
+	struct trace_pid_list *no_pid_list;
 	struct trace_pid_list *pid_list;
+	bool ret;
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
+	no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
-		       trace_ignore_this_task(pid_list, prev) &&
-		       trace_ignore_this_task(pid_list, next));
+	/*
+	 * Sched switch is funny, as we only want to ignore it
+	 * in the notrace case if both prev and next should be ignored.
+	 */
+	ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
+		trace_ignore_this_task(NULL, no_pid_list, next);
+
+	this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
+		       (trace_ignore_this_task(pid_list, NULL, prev) &&
+			trace_ignore_this_task(pid_list, NULL, next)));
 }
 
 static void
@@ -556,58 +578,55 @@
 		    struct task_struct *prev, struct task_struct *next)
 {
 	struct trace_array *tr = data;
+	struct trace_pid_list *no_pid_list;
 	struct trace_pid_list *pid_list;
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
+	no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
-		       trace_ignore_this_task(pid_list, next));
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
+		       trace_ignore_this_task(pid_list, no_pid_list, next));
 }
 
 static void
 event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
 {
 	struct trace_array *tr = data;
+	struct trace_pid_list *no_pid_list;
 	struct trace_pid_list *pid_list;
 
 	/* Nothing to do if we are already tracing */
-	if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
+	if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
 		return;
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
+	no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
-		       trace_ignore_this_task(pid_list, task));
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
+		       trace_ignore_this_task(pid_list, no_pid_list, task));
 }
 
 static void
 event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
 {
 	struct trace_array *tr = data;
+	struct trace_pid_list *no_pid_list;
 	struct trace_pid_list *pid_list;
 
 	/* Nothing to do if we are not tracing */
-	if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
+	if (this_cpu_read(tr->array_buffer.data->ignore_pid))
 		return;
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
+	no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
 
 	/* Set tracing if current is enabled */
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
-		       trace_ignore_this_task(pid_list, current));
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
+		       trace_ignore_this_task(pid_list, no_pid_list, current));
 }
 
-static void __ftrace_clear_event_pids(struct trace_array *tr)
+static void unregister_pid_events(struct trace_array *tr)
 {
-	struct trace_pid_list *pid_list;
-	struct trace_event_file *file;
-	int cpu;
-
-	pid_list = rcu_dereference_protected(tr->filtered_pids,
-					     lockdep_is_held(&event_mutex));
-	if (!pid_list)
-		return;
-
 	unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
 	unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
 
@@ -619,26 +638,55 @@
 
 	unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
 	unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
+}
 
-	list_for_each_entry(file, &tr->events, list) {
-		clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
+static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
+{
+	struct trace_pid_list *pid_list;
+	struct trace_pid_list *no_pid_list;
+	struct trace_event_file *file;
+	int cpu;
+
+	pid_list = rcu_dereference_protected(tr->filtered_pids,
+					     lockdep_is_held(&event_mutex));
+	no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
+					     lockdep_is_held(&event_mutex));
+
+	/* Make sure there's something to do */
+	if (!pid_type_enabled(type, pid_list, no_pid_list))
+		return;
+
+	if (!still_need_pid_events(type, pid_list, no_pid_list)) {
+		unregister_pid_events(tr);
+
+		list_for_each_entry(file, &tr->events, list) {
+			clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
+		}
+
+		for_each_possible_cpu(cpu)
+			per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
 	}
 
-	for_each_possible_cpu(cpu)
-		per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
+	if (type & TRACE_PIDS)
+		rcu_assign_pointer(tr->filtered_pids, NULL);
 
-	rcu_assign_pointer(tr->filtered_pids, NULL);
+	if (type & TRACE_NO_PIDS)
+		rcu_assign_pointer(tr->filtered_no_pids, NULL);
 
 	/* Wait till all users are no longer using pid filtering */
 	tracepoint_synchronize_unregister();
 
-	trace_free_pid_list(pid_list);
+	if ((type & TRACE_PIDS) && pid_list)
+		trace_free_pid_list(pid_list);
+
+	if ((type & TRACE_NO_PIDS) && no_pid_list)
+		trace_free_pid_list(no_pid_list);
 }
 
-static void ftrace_clear_event_pids(struct trace_array *tr)
+static void ftrace_clear_event_pids(struct trace_array *tr, int type)
 {
 	mutex_lock(&event_mutex);
-	__ftrace_clear_event_pids(tr);
+	__ftrace_clear_event_pids(tr, type);
 	mutex_unlock(&event_mutex);
 }
 
@@ -697,7 +745,7 @@
 		return;
 
 	if (!--dir->nr_events) {
-		tracefs_remove_recursive(dir->entry);
+		tracefs_remove(dir->entry);
 		list_del(&dir->list);
 		__put_system_dir(dir);
 	}
@@ -716,7 +764,7 @@
 		}
 		spin_unlock(&dir->d_lock);
 
-		tracefs_remove_recursive(dir);
+		tracefs_remove(dir);
 	}
 
 	list_del(&file->list);
@@ -827,7 +875,6 @@
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(ftrace_set_clr_event);
 
 /**
  * trace_set_clr_event - enable or disable an event
@@ -852,6 +899,32 @@
 }
 EXPORT_SYMBOL_GPL(trace_set_clr_event);
 
+/**
+ * trace_array_set_clr_event - enable or disable an event for a trace array.
+ * @tr: concerned trace array.
+ * @system: system name to match (NULL for any system)
+ * @event: event name to match (NULL for all events, within system)
+ * @enable: true to enable, false to disable
+ *
+ * This is a way for other parts of the kernel to enable or disable
+ * event recording.
+ *
+ * Returns 0 on success, -EINVAL if the parameters do not match any
+ * registered events.
+ */
+int trace_array_set_clr_event(struct trace_array *tr, const char *system,
+		const char *event, bool enable)
+{
+	int set;
+
+	if (!tr)
+		return -ENOENT;
+
+	set = (enable == true) ? 1 : 0;
+	return __ftrace_set_clr_event(tr, NULL, system, event, set);
+}
+EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
+
 /* 128 should be much more than enough */
 #define EVENT_BUF_SIZE		127
 
@@ -986,15 +1059,32 @@
 }
 
 static void *
-p_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, void *v, loff_t *pos, int type)
 {
 	struct trace_array *tr = m->private;
-	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
+	struct trace_pid_list *pid_list;
+
+	if (type == TRACE_PIDS)
+		pid_list = rcu_dereference_sched(tr->filtered_pids);
+	else
+		pid_list = rcu_dereference_sched(tr->filtered_no_pids);
 
 	return trace_pid_next(pid_list, v, pos);
 }
 
-static void *p_start(struct seq_file *m, loff_t *pos)
+static void *
+p_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	return __next(m, v, pos, TRACE_PIDS);
+}
+
+static void *
+np_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	return __next(m, v, pos, TRACE_NO_PIDS);
+}
+
+static void *__start(struct seq_file *m, loff_t *pos, int type)
 	__acquires(RCU)
 {
 	struct trace_pid_list *pid_list;
@@ -1009,7 +1099,10 @@
 	mutex_lock(&event_mutex);
 	rcu_read_lock_sched();
 
-	pid_list = rcu_dereference_sched(tr->filtered_pids);
+	if (type == TRACE_PIDS)
+		pid_list = rcu_dereference_sched(tr->filtered_pids);
+	else
+		pid_list = rcu_dereference_sched(tr->filtered_no_pids);
 
 	if (!pid_list)
 		return NULL;
@@ -1017,6 +1110,18 @@
 	return trace_pid_start(pid_list, pos);
 }
 
+static void *p_start(struct seq_file *m, loff_t *pos)
+	__acquires(RCU)
+{
+	return __start(m, pos, TRACE_PIDS);
+}
+
+static void *np_start(struct seq_file *m, loff_t *pos)
+	__acquires(RCU)
+{
+	return __start(m, pos, TRACE_NO_PIDS);
+}
+
 static void p_stop(struct seq_file *m, void *p)
 	__releases(RCU)
 {
@@ -1562,6 +1667,7 @@
 {
 	struct trace_array *tr = data;
 	struct trace_pid_list *pid_list;
+	struct trace_pid_list *no_pid_list;
 
 	/*
 	 * This function is called by on_each_cpu() while the
@@ -1569,18 +1675,50 @@
 	 */
 	pid_list = rcu_dereference_protected(tr->filtered_pids,
 					     mutex_is_locked(&event_mutex));
+	no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
+					     mutex_is_locked(&event_mutex));
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
-		       trace_ignore_this_task(pid_list, current));
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
+		       trace_ignore_this_task(pid_list, no_pid_list, current));
+}
+
+static void register_pid_events(struct trace_array *tr)
+{
+	/*
+	 * Register a probe that is called before all other probes
+	 * to set ignore_pid if next or prev do not match.
+	 * Register a probe this is called after all other probes
+	 * to only keep ignore_pid set if next pid matches.
+	 */
+	register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
+					 tr, INT_MAX);
+	register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
+					 tr, 0);
+
+	register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
+					 tr, INT_MAX);
+	register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
+					 tr, 0);
+
+	register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
+					     tr, INT_MAX);
+	register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
+					     tr, 0);
+
+	register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
+					 tr, INT_MAX);
+	register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
+					 tr, 0);
 }
 
 static ssize_t
-ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
-		       size_t cnt, loff_t *ppos)
+event_pid_write(struct file *filp, const char __user *ubuf,
+		size_t cnt, loff_t *ppos, int type)
 {
 	struct seq_file *m = filp->private_data;
 	struct trace_array *tr = m->private;
 	struct trace_pid_list *filtered_pids = NULL;
+	struct trace_pid_list *other_pids = NULL;
 	struct trace_pid_list *pid_list;
 	struct trace_event_file *file;
 	ssize_t ret;
@@ -1594,14 +1732,26 @@
 
 	mutex_lock(&event_mutex);
 
-	filtered_pids = rcu_dereference_protected(tr->filtered_pids,
-					     lockdep_is_held(&event_mutex));
+	if (type == TRACE_PIDS) {
+		filtered_pids = rcu_dereference_protected(tr->filtered_pids,
+							  lockdep_is_held(&event_mutex));
+		other_pids = rcu_dereference_protected(tr->filtered_no_pids,
+							  lockdep_is_held(&event_mutex));
+	} else {
+		filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
+							  lockdep_is_held(&event_mutex));
+		other_pids = rcu_dereference_protected(tr->filtered_pids,
+							  lockdep_is_held(&event_mutex));
+	}
 
 	ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
 	if (ret < 0)
 		goto out;
 
-	rcu_assign_pointer(tr->filtered_pids, pid_list);
+	if (type == TRACE_PIDS)
+		rcu_assign_pointer(tr->filtered_pids, pid_list);
+	else
+		rcu_assign_pointer(tr->filtered_no_pids, pid_list);
 
 	list_for_each_entry(file, &tr->events, list) {
 		set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
@@ -1610,32 +1760,8 @@
 	if (filtered_pids) {
 		tracepoint_synchronize_unregister();
 		trace_free_pid_list(filtered_pids);
-	} else if (pid_list) {
-		/*
-		 * Register a probe that is called before all other probes
-		 * to set ignore_pid if next or prev do not match.
-		 * Register a probe this is called after all other probes
-		 * to only keep ignore_pid set if next pid matches.
-		 */
-		register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
-						 tr, INT_MAX);
-		register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
-						 tr, 0);
-
-		register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
-						 tr, INT_MAX);
-		register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
-						 tr, 0);
-
-		register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
-						     tr, INT_MAX);
-		register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
-						     tr, 0);
-
-		register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
-						 tr, INT_MAX);
-		register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
-						 tr, 0);
+	} else if (pid_list && !other_pids) {
+		register_pid_events(tr);
 	}
 
 	/*
@@ -1654,9 +1780,24 @@
 	return ret;
 }
 
+static ssize_t
+ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
+		       size_t cnt, loff_t *ppos)
+{
+	return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
+}
+
+static ssize_t
+ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
+			size_t cnt, loff_t *ppos)
+{
+	return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
+}
+
 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
 static int ftrace_event_set_open(struct inode *inode, struct file *file);
 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
+static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
 static int ftrace_event_release(struct inode *inode, struct file *file);
 
 static const struct seq_operations show_event_seq_ops = {
@@ -1680,6 +1821,13 @@
 	.stop = p_stop,
 };
 
+static const struct seq_operations show_set_no_pid_seq_ops = {
+	.start = np_start,
+	.next = np_next,
+	.show = trace_pid_show,
+	.stop = p_stop,
+};
+
 static const struct file_operations ftrace_avail_fops = {
 	.open = ftrace_event_avail_open,
 	.read = seq_read,
@@ -1703,6 +1851,14 @@
 	.release = ftrace_event_release,
 };
 
+static const struct file_operations ftrace_set_event_notrace_pid_fops = {
+	.open = ftrace_event_set_npid_open,
+	.read = seq_read,
+	.write = ftrace_event_npid_write,
+	.llseek = seq_lseek,
+	.release = ftrace_event_release,
+};
+
 static const struct file_operations ftrace_enable_fops = {
 	.open = tracing_open_generic,
 	.read = event_enable_read,
@@ -1832,7 +1988,28 @@
 
 	if ((file->f_mode & FMODE_WRITE) &&
 	    (file->f_flags & O_TRUNC))
-		ftrace_clear_event_pids(tr);
+		ftrace_clear_event_pids(tr, TRACE_PIDS);
+
+	ret = ftrace_event_open(inode, file, seq_ops);
+	if (ret < 0)
+		trace_array_put(tr);
+	return ret;
+}
+
+static int
+ftrace_event_set_npid_open(struct inode *inode, struct file *file)
+{
+	const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
+	struct trace_array *tr = inode->i_private;
+	int ret;
+
+	ret = tracing_check_open_get_tr(tr);
+	if (ret)
+		return ret;
+
+	if ((file->f_mode & FMODE_WRITE) &&
+	    (file->f_flags & O_TRUNC))
+		ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
 
 	ret = ftrace_event_open(inode, file, seq_ops);
 	if (ret < 0)
@@ -1949,11 +2126,47 @@
 }
 
 static int
+event_define_fields(struct trace_event_call *call)
+{
+	struct list_head *head;
+	int ret = 0;
+
+	/*
+	 * Other events may have the same class. Only update
+	 * the fields if they are not already defined.
+	 */
+	head = trace_get_fields(call);
+	if (list_empty(head)) {
+		struct trace_event_fields *field = call->class->fields_array;
+		unsigned int offset = sizeof(struct trace_entry);
+
+		for (; field->type; field++) {
+			if (field->type == TRACE_FUNCTION_TYPE) {
+				field->define_fields(call);
+				break;
+			}
+
+			offset = ALIGN(offset, field->align);
+			ret = trace_define_field(call, field->type, field->name,
+						 offset, field->size,
+						 field->is_signed, field->filter_type);
+			if (WARN_ON_ONCE(ret)) {
+				pr_err("error code is %d\n", ret);
+				break;
+			}
+
+			offset += field->size;
+		}
+	}
+
+	return ret;
+}
+
+static int
 event_create_dir(struct dentry *parent, struct trace_event_file *file)
 {
 	struct trace_event_call *call = file->event_call;
 	struct trace_array *tr = file->tr;
-	struct list_head *head;
 	struct dentry *d_events;
 	const char *name;
 	int ret;
@@ -1987,18 +2200,10 @@
 				  &ftrace_event_id_fops);
 #endif
 
-	/*
-	 * Other events may have the same class. Only update
-	 * the fields if they are not already defined.
-	 */
-	head = trace_get_fields(call);
-	if (list_empty(head)) {
-		ret = call->class->define_fields(call);
-		if (ret < 0) {
-			pr_warn("Could not initialize trace point events/%s\n",
-				name);
-			return -1;
-		}
+	ret = event_define_fields(call);
+	if (ret < 0) {
+		pr_warn("Could not initialize trace point events/%s\n", name);
+		return ret;
 	}
 
 	/*
@@ -2017,9 +2222,19 @@
 	trace_create_file("hist", 0444, file->dir, file,
 			  &event_hist_fops);
 #endif
+#ifdef CONFIG_HIST_TRIGGERS_DEBUG
+	trace_create_file("hist_debug", 0444, file->dir, file,
+			  &event_hist_debug_fops);
+#endif
 	trace_create_file("format", 0444, file->dir, call,
 			  &ftrace_event_format_fops);
 
+#ifdef CONFIG_TRACE_EVENT_INJECT
+	if (call->event.type && call->class->reg)
+		trace_create_file("inject", 0200, file->dir, file,
+				  &event_inject_fops);
+#endif
+
 	return 0;
 }
 
@@ -2247,12 +2462,22 @@
 trace_create_new_event(struct trace_event_call *call,
 		       struct trace_array *tr)
 {
+	struct trace_pid_list *no_pid_list;
+	struct trace_pid_list *pid_list;
 	struct trace_event_file *file;
 
 	file = kmem_cache_alloc(file_cachep, GFP_TRACE);
 	if (!file)
 		return NULL;
 
+	pid_list = rcu_dereference_protected(tr->filtered_pids,
+					     lockdep_is_held(&event_mutex));
+	no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
+					     lockdep_is_held(&event_mutex));
+
+	if (pid_list || no_pid_list)
+		file->flags |= EVENT_FILE_FL_PID_FILTER;
+
 	file->event_call = call;
 	file->tr = tr;
 	atomic_set(&file->sm_ref, 0);
@@ -2273,7 +2498,10 @@
 	if (!file)
 		return -ENOMEM;
 
-	return event_create_dir(tr->event_dir, file);
+	if (eventdir_initialized)
+		return event_create_dir(tr->event_dir, file);
+	else
+		return event_define_fields(call);
 }
 
 /*
@@ -2281,7 +2509,7 @@
  * for enabling events at boot. We want to enable events before
  * the filesystem is initialized.
  */
-static __init int
+static int
 __trace_early_add_new_event(struct trace_event_call *call,
 			    struct trace_array *tr)
 {
@@ -2291,7 +2519,7 @@
 	if (!file)
 		return -ENOMEM;
 
-	return 0;
+	return event_define_fields(call);
 }
 
 struct ftrace_module_file_ops;
@@ -2444,7 +2672,7 @@
 	mutex_unlock(&trace_types_lock);
 	mutex_unlock(&event_mutex);
 
-	return 0;
+	return NOTIFY_OK;
 }
 
 static struct notifier_block trace_module_nb = {
@@ -2505,6 +2733,91 @@
 	return file;
 }
 
+/**
+ * trace_get_event_file - Find and return a trace event file
+ * @instance: The name of the trace instance containing the event
+ * @system: The name of the system containing the event
+ * @event: The name of the event
+ *
+ * Return a trace event file given the trace instance name, trace
+ * system, and trace event name.  If the instance name is NULL, it
+ * refers to the top-level trace array.
+ *
+ * This function will look it up and return it if found, after calling
+ * trace_array_get() to prevent the instance from going away, and
+ * increment the event's module refcount to prevent it from being
+ * removed.
+ *
+ * To release the file, call trace_put_event_file(), which will call
+ * trace_array_put() and decrement the event's module refcount.
+ *
+ * Return: The trace event on success, ERR_PTR otherwise.
+ */
+struct trace_event_file *trace_get_event_file(const char *instance,
+					      const char *system,
+					      const char *event)
+{
+	struct trace_array *tr = top_trace_array();
+	struct trace_event_file *file = NULL;
+	int ret = -EINVAL;
+
+	if (instance) {
+		tr = trace_array_find_get(instance);
+		if (!tr)
+			return ERR_PTR(-ENOENT);
+	} else {
+		ret = trace_array_get(tr);
+		if (ret)
+			return ERR_PTR(ret);
+	}
+
+	mutex_lock(&event_mutex);
+
+	file = find_event_file(tr, system, event);
+	if (!file) {
+		trace_array_put(tr);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Don't let event modules unload while in use */
+	ret = try_module_get(file->event_call->mod);
+	if (!ret) {
+		trace_array_put(tr);
+		ret = -EBUSY;
+		goto out;
+	}
+
+	ret = 0;
+ out:
+	mutex_unlock(&event_mutex);
+
+	if (ret)
+		file = ERR_PTR(ret);
+
+	return file;
+}
+EXPORT_SYMBOL_GPL(trace_get_event_file);
+
+/**
+ * trace_put_event_file - Release a file from trace_get_event_file()
+ * @file: The trace event file
+ *
+ * If a file was retrieved using trace_get_event_file(), this should
+ * be called when it's no longer needed.  It will cancel the previous
+ * trace_array_get() called by that function, and decrement the
+ * event's module refcount.
+ */
+void trace_put_event_file(struct trace_event_file *file)
+{
+	mutex_lock(&event_mutex);
+	module_put(file->event_call->mod);
+	mutex_unlock(&event_mutex);
+
+	trace_array_put(file->tr);
+}
+EXPORT_SYMBOL_GPL(trace_put_event_file);
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 /* Avoid typos */
@@ -2829,14 +3142,13 @@
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 /*
- * The top level array has already had its trace_event_file
- * descriptors created in order to allow for early events to
- * be recorded. This function is called after the tracefs has been
- * initialized, and we now have to create the files associated
- * to the events.
+ * The top level array and trace arrays created by boot-time tracing
+ * have already had its trace_event_file descriptors created in order
+ * to allow for early events to be recorded.
+ * This function is called after the tracefs has been initialized,
+ * and we now have to create the files associated to the events.
  */
-static __init void
-__trace_early_add_event_dirs(struct trace_array *tr)
+static void __trace_early_add_event_dirs(struct trace_array *tr)
 {
 	struct trace_event_file *file;
 	int ret;
@@ -2851,13 +3163,12 @@
 }
 
 /*
- * For early boot up, the top trace array requires to have
- * a list of events that can be enabled. This must be done before
- * the filesystem is set up in order to allow events to be traced
- * early.
+ * For early boot up, the top trace array and the trace arrays created
+ * by boot-time tracing require to have a list of events that can be
+ * enabled. This must be done before the filesystem is set up in order
+ * to allow events to be traced early.
  */
-static __init void
-__trace_early_add_events(struct trace_array *tr)
+void __trace_early_add_events(struct trace_array *tr)
 {
 	struct trace_event_call *call;
 	int ret;
@@ -2901,7 +3212,7 @@
 {
 	strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
 	ring_buffer_expanded = true;
-	tracing_selftest_disabled = true;
+	disable_tracing_selftest("running event tracing");
 
 	return 1;
 }
@@ -2941,6 +3252,11 @@
 	if (!entry)
 		pr_warn("Could not create tracefs 'set_event_pid' entry\n");
 
+	entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
+				    tr, &ftrace_set_event_notrace_pid_fops);
+	if (!entry)
+		pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
+
 	/* ring buffer internal formats */
 	entry = trace_create_file("header_page", 0444, d_events,
 				  ring_buffer_print_page_header,
@@ -2983,7 +3299,11 @@
 		goto out;
 
 	down_write(&trace_event_sem);
-	__trace_add_event_dirs(tr);
+	/* If tr already has the event list, it is initialized in early boot. */
+	if (unlikely(!list_empty(&tr->events)))
+		__trace_early_add_event_dirs(tr);
+	else
+		__trace_add_event_dirs(tr);
 	up_write(&trace_event_sem);
 
  out:
@@ -3024,7 +3344,7 @@
 	clear_event_triggers(tr);
 
 	/* Clear the pid list */
-	__ftrace_clear_event_pids(tr);
+	__ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
 
 	/* Disable any running events */
 	__ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
@@ -3034,7 +3354,7 @@
 
 	down_write(&trace_event_sem);
 	__trace_remove_event_dirs(tr);
-	tracefs_remove_recursive(tr->event_dir);
+	tracefs_remove(tr->event_dir);
 	up_write(&trace_event_sem);
 
 	tr->event_dir = NULL;
@@ -3139,10 +3459,21 @@
 
 early_initcall(event_trace_enable_again);
 
+/* Init fields which doesn't related to the tracefs */
+static __init int event_trace_init_fields(void)
+{
+	if (trace_define_generic_fields())
+		pr_warn("tracing: Failed to allocated generic fields");
+
+	if (trace_define_common_fields())
+		pr_warn("tracing: Failed to allocate common fields");
+
+	return 0;
+}
+
 __init int event_trace_init(void)
 {
 	struct trace_array *tr;
-	struct dentry *d_tracer;
 	struct dentry *entry;
 	int ret;
 
@@ -3150,22 +3481,12 @@
 	if (!tr)
 		return -ENODEV;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
-		return 0;
-
-	entry = tracefs_create_file("available_events", 0444, d_tracer,
+	entry = tracefs_create_file("available_events", 0444, NULL,
 				    tr, &ftrace_avail_fops);
 	if (!entry)
 		pr_warn("Could not create tracefs 'available_events' entry\n");
 
-	if (trace_define_generic_fields())
-		pr_warn("tracing: Failed to allocated generic fields");
-
-	if (trace_define_common_fields())
-		pr_warn("tracing: Failed to allocate common fields");
-
-	ret = early_event_add_tracer(d_tracer, tr);
+	ret = early_event_add_tracer(NULL, tr);
 	if (ret)
 		return ret;
 
@@ -3174,6 +3495,9 @@
 	if (ret)
 		pr_warn("Failed to register trace events module notifier\n");
 #endif
+
+	eventdir_initialized = true;
+
 	return 0;
 }
 
@@ -3182,6 +3506,7 @@
 	event_trace_memsetup();
 	init_ftrace_syscalls();
 	event_trace_enable();
+	event_trace_init_fields();
 }
 
 #ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
@@ -3361,8 +3686,8 @@
 function_test_events_call(unsigned long ip, unsigned long parent_ip,
 			  struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	struct ftrace_entry *entry;
 	unsigned long flags;
 	long disabled;
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index bf44f6b..a255ffb 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com>
  */
 
+#include <linux/uaccess.h>
 #include <linux/module.h>
 #include <linux/ctype.h>
 #include <linux/mutex.h>
@@ -499,7 +500,7 @@
 					ptr++;
 					break;
 				}
-				/* fall through */
+				fallthrough;
 			default:
 				parse_error(pe, FILT_ERR_TOO_MANY_PREDS,
 					    next - str);
@@ -654,6 +655,52 @@
 DEFINE_EQUALITY_PRED(16);
 DEFINE_EQUALITY_PRED(8);
 
+/* user space strings temp buffer */
+#define USTRING_BUF_SIZE	1024
+
+struct ustring_buffer {
+	char		buffer[USTRING_BUF_SIZE];
+};
+
+static __percpu struct ustring_buffer *ustring_per_cpu;
+
+static __always_inline char *test_string(char *str)
+{
+	struct ustring_buffer *ubuf;
+	char *kstr;
+
+	if (!ustring_per_cpu)
+		return NULL;
+
+	ubuf = this_cpu_ptr(ustring_per_cpu);
+	kstr = ubuf->buffer;
+
+	/* For safety, do not trust the string pointer */
+	if (!strncpy_from_kernel_nofault(kstr, str, USTRING_BUF_SIZE))
+		return NULL;
+	return kstr;
+}
+
+static __always_inline char *test_ustring(char *str)
+{
+	struct ustring_buffer *ubuf;
+	char __user *ustr;
+	char *kstr;
+
+	if (!ustring_per_cpu)
+		return NULL;
+
+	ubuf = this_cpu_ptr(ustring_per_cpu);
+	kstr = ubuf->buffer;
+
+	/* user space address? */
+	ustr = (char __user *)str;
+	if (!strncpy_from_user_nofault(kstr, ustr, USTRING_BUF_SIZE))
+		return NULL;
+
+	return kstr;
+}
+
 /* Filter predicate for fixed sized arrays of characters */
 static int filter_pred_string(struct filter_pred *pred, void *event)
 {
@@ -667,19 +714,43 @@
 	return match;
 }
 
-/* Filter predicate for char * pointers */
-static int filter_pred_pchar(struct filter_pred *pred, void *event)
+static __always_inline int filter_pchar(struct filter_pred *pred, char *str)
 {
-	char **addr = (char **)(event + pred->offset);
 	int cmp, match;
-	int len = strlen(*addr) + 1;	/* including tailing '\0' */
+	int len;
 
-	cmp = pred->regex.match(*addr, &pred->regex, len);
+	len = strlen(str) + 1;	/* including tailing '\0' */
+	cmp = pred->regex.match(str, &pred->regex, len);
 
 	match = cmp ^ pred->not;
 
 	return match;
 }
+/* Filter predicate for char * pointers */
+static int filter_pred_pchar(struct filter_pred *pred, void *event)
+{
+	char **addr = (char **)(event + pred->offset);
+	char *str;
+
+	str = test_string(*addr);
+	if (!str)
+		return 0;
+
+	return filter_pchar(pred, str);
+}
+
+/* Filter predicate for char * pointers in user space*/
+static int filter_pred_pchar_user(struct filter_pred *pred, void *event)
+{
+	char **addr = (char **)(event + pred->offset);
+	char *str;
+
+	str = test_ustring(*addr);
+	if (!str)
+		return 0;
+
+	return filter_pchar(pred, str);
+}
 
 /*
  * Filter predicate for dynamic sized arrays of characters.
@@ -1158,6 +1229,7 @@
 	struct filter_pred *pred = NULL;
 	char num_buf[24];	/* Big enough to hold an address */
 	char *field_name;
+	bool ustring = false;
 	char q;
 	u64 val;
 	int len;
@@ -1192,6 +1264,12 @@
 		return -EINVAL;
 	}
 
+	/* See if the field is a user space string */
+	if ((len = str_has_prefix(str + i, ".ustring"))) {
+		ustring = true;
+		i += len;
+	}
+
 	while (isspace(str[i]))
 		i++;
 
@@ -1273,7 +1351,7 @@
 		switch (op) {
 		case OP_NE:
 			pred->not = 1;
-			/* Fall through */
+			fallthrough;
 		case OP_GLOB:
 		case OP_EQ:
 			break;
@@ -1320,8 +1398,20 @@
 
 		} else if (field->filter_type == FILTER_DYN_STRING)
 			pred->fn = filter_pred_strloc;
-		else
-			pred->fn = filter_pred_pchar;
+		else {
+
+			if (!ustring_per_cpu) {
+				/* Once allocated, keep it around for good */
+				ustring_per_cpu = alloc_percpu(struct ustring_buffer);
+				if (!ustring_per_cpu)
+					goto err_mem;
+			}
+
+			if (ustring)
+				pred->fn = filter_pred_pchar_user;
+			else
+				pred->fn = filter_pred_pchar;
+		}
 		/* go past the last quote */
 		i++;
 
@@ -1387,6 +1477,9 @@
 err_free:
 	kfree(pred);
 	return -EINVAL;
+err_mem:
+	kfree(pred);
+	return -ENOMEM;
 }
 
 enum {
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f637663..eb72006 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -19,13 +19,7 @@
 #include <trace/events/mmflags.h>
 
 #include "tracing_map.h"
-#include "trace.h"
-#include "trace_dynevent.h"
-
-#define SYNTH_SYSTEM		"synthetic"
-#define SYNTH_FIELDS_MAX	16
-
-#define STR_VAR_LEN_MAX		32 /* must be multiple of sizeof(u64) */
+#include "trace_synth.h"
 
 #define ERRORS								\
 	C(NONE,			"No error"),				\
@@ -67,6 +61,11 @@
 	C(INVALID_REF_KEY,	"Using variable references in keys not supported"), \
 	C(VAR_NOT_FOUND,	"Couldn't find variable"),		\
 	C(FIELD_NOT_FOUND,	"Couldn't find field"),			\
+	C(EMPTY_ASSIGNMENT,	"Empty assignment"),			\
+	C(INVALID_SORT_MODIFIER,"Invalid sort modifier"),		\
+	C(EMPTY_SORT_FIELD,	"Empty sort field"),			\
+	C(TOO_MANY_SORT_FIELDS,	"Too many sort fields (Max = 2)"),	\
+	C(INVALID_SORT_FIELD,	"Sort field must be a key or a val"),	\
 	C(INVALID_STR_OPERAND,	"String type can not be an operand in expression"),
 
 #undef C
@@ -149,6 +148,8 @@
 	 */
 	unsigned int			var_ref_idx;
 	bool                            read_once;
+
+	unsigned int			var_str_idx;
 };
 
 static u64 hist_field_none(struct hist_field *field,
@@ -351,6 +352,7 @@
 	unsigned int			n_keys;
 	unsigned int			n_fields;
 	unsigned int			n_vars;
+	unsigned int			n_var_str;
 	unsigned int			key_size;
 	struct tracing_map_sort_key	sort_keys[TRACING_MAP_SORT_KEYS_MAX];
 	unsigned int			n_sort_keys;
@@ -376,67 +378,6 @@
 	unsigned int			n_save_var_str;
 };
 
-static int synth_event_create(int argc, const char **argv);
-static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
-static int synth_event_release(struct dyn_event *ev);
-static bool synth_event_is_busy(struct dyn_event *ev);
-static bool synth_event_match(const char *system, const char *event,
-			int argc, const char **argv, struct dyn_event *ev);
-
-static struct dyn_event_operations synth_event_ops = {
-	.create = synth_event_create,
-	.show = synth_event_show,
-	.is_busy = synth_event_is_busy,
-	.free = synth_event_release,
-	.match = synth_event_match,
-};
-
-struct synth_field {
-	char *type;
-	char *name;
-	size_t size;
-	bool is_signed;
-	bool is_string;
-};
-
-struct synth_event {
-	struct dyn_event			devent;
-	int					ref;
-	char					*name;
-	struct synth_field			**fields;
-	unsigned int				n_fields;
-	unsigned int				n_u64;
-	struct trace_event_class		class;
-	struct trace_event_call			call;
-	struct tracepoint			*tp;
-};
-
-static bool is_synth_event(struct dyn_event *ev)
-{
-	return ev->ops == &synth_event_ops;
-}
-
-static struct synth_event *to_synth_event(struct dyn_event *ev)
-{
-	return container_of(ev, struct synth_event, devent);
-}
-
-static bool synth_event_is_busy(struct dyn_event *ev)
-{
-	struct synth_event *event = to_synth_event(ev);
-
-	return event->ref != 0;
-}
-
-static bool synth_event_match(const char *system, const char *event,
-			int argc, const char **argv, struct dyn_event *ev)
-{
-	struct synth_event *sev = to_synth_event(ev);
-
-	return strcmp(sev->name, event) == 0 &&
-		(!system || strcmp(system, SYNTH_SYSTEM) == 0);
-}
-
 struct action_data;
 
 typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
@@ -583,6 +524,7 @@
 		track_data_free(data);
 		return ERR_PTR(-ENOMEM);
 	}
+
 	data->elt.private_data = elt_data;
 
 	elt_data->comm = kzalloc(TASK_COMM_LEN, GFP_KERNEL);
@@ -610,11 +552,11 @@
 	if (!str)
 		return;
 
-	strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);
+	strcpy(last_cmd, "hist:");
+	strncat(last_cmd, str, MAX_FILTER_STR_VAL - 1 - sizeof("hist:"));
 
 	if (file) {
 		call = file->event_call;
-
 		system = call->class->system;
 		if (system) {
 			name = trace_event_name(call);
@@ -639,508 +581,6 @@
 	last_cmd_loc[0] = '\0';
 }
 
-struct synth_trace_event {
-	struct trace_entry	ent;
-	u64			fields[];
-};
-
-static int synth_event_define_fields(struct trace_event_call *call)
-{
-	struct synth_trace_event trace;
-	int offset = offsetof(typeof(trace), fields);
-	struct synth_event *event = call->data;
-	unsigned int i, size, n_u64;
-	char *name, *type;
-	bool is_signed;
-	int ret = 0;
-
-	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
-		size = event->fields[i]->size;
-		is_signed = event->fields[i]->is_signed;
-		type = event->fields[i]->type;
-		name = event->fields[i]->name;
-		ret = trace_define_field(call, type, name, offset, size,
-					 is_signed, FILTER_OTHER);
-		if (ret)
-			break;
-
-		if (event->fields[i]->is_string) {
-			offset += STR_VAR_LEN_MAX;
-			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
-		} else {
-			offset += sizeof(u64);
-			n_u64++;
-		}
-	}
-
-	event->n_u64 = n_u64;
-
-	return ret;
-}
-
-static bool synth_field_signed(char *type)
-{
-	if (str_has_prefix(type, "u"))
-		return false;
-	if (strcmp(type, "gfp_t") == 0)
-		return false;
-
-	return true;
-}
-
-static int synth_field_is_string(char *type)
-{
-	if (strstr(type, "char[") != NULL)
-		return true;
-
-	return false;
-}
-
-static int synth_field_string_size(char *type)
-{
-	char buf[4], *end, *start;
-	unsigned int len;
-	int size, err;
-
-	start = strstr(type, "char[");
-	if (start == NULL)
-		return -EINVAL;
-	start += sizeof("char[") - 1;
-
-	end = strchr(type, ']');
-	if (!end || end < start)
-		return -EINVAL;
-
-	len = end - start;
-	if (len > 3)
-		return -EINVAL;
-
-	strncpy(buf, start, len);
-	buf[len] = '\0';
-
-	err = kstrtouint(buf, 0, &size);
-	if (err)
-		return err;
-
-	if (size > STR_VAR_LEN_MAX)
-		return -EINVAL;
-
-	return size;
-}
-
-static int synth_field_size(char *type)
-{
-	int size = 0;
-
-	if (strcmp(type, "s64") == 0)
-		size = sizeof(s64);
-	else if (strcmp(type, "u64") == 0)
-		size = sizeof(u64);
-	else if (strcmp(type, "s32") == 0)
-		size = sizeof(s32);
-	else if (strcmp(type, "u32") == 0)
-		size = sizeof(u32);
-	else if (strcmp(type, "s16") == 0)
-		size = sizeof(s16);
-	else if (strcmp(type, "u16") == 0)
-		size = sizeof(u16);
-	else if (strcmp(type, "s8") == 0)
-		size = sizeof(s8);
-	else if (strcmp(type, "u8") == 0)
-		size = sizeof(u8);
-	else if (strcmp(type, "char") == 0)
-		size = sizeof(char);
-	else if (strcmp(type, "unsigned char") == 0)
-		size = sizeof(unsigned char);
-	else if (strcmp(type, "int") == 0)
-		size = sizeof(int);
-	else if (strcmp(type, "unsigned int") == 0)
-		size = sizeof(unsigned int);
-	else if (strcmp(type, "long") == 0)
-		size = sizeof(long);
-	else if (strcmp(type, "unsigned long") == 0)
-		size = sizeof(unsigned long);
-	else if (strcmp(type, "pid_t") == 0)
-		size = sizeof(pid_t);
-	else if (strcmp(type, "gfp_t") == 0)
-		size = sizeof(gfp_t);
-	else if (synth_field_is_string(type))
-		size = synth_field_string_size(type);
-
-	return size;
-}
-
-static const char *synth_field_fmt(char *type)
-{
-	const char *fmt = "%llu";
-
-	if (strcmp(type, "s64") == 0)
-		fmt = "%lld";
-	else if (strcmp(type, "u64") == 0)
-		fmt = "%llu";
-	else if (strcmp(type, "s32") == 0)
-		fmt = "%d";
-	else if (strcmp(type, "u32") == 0)
-		fmt = "%u";
-	else if (strcmp(type, "s16") == 0)
-		fmt = "%d";
-	else if (strcmp(type, "u16") == 0)
-		fmt = "%u";
-	else if (strcmp(type, "s8") == 0)
-		fmt = "%d";
-	else if (strcmp(type, "u8") == 0)
-		fmt = "%u";
-	else if (strcmp(type, "char") == 0)
-		fmt = "%d";
-	else if (strcmp(type, "unsigned char") == 0)
-		fmt = "%u";
-	else if (strcmp(type, "int") == 0)
-		fmt = "%d";
-	else if (strcmp(type, "unsigned int") == 0)
-		fmt = "%u";
-	else if (strcmp(type, "long") == 0)
-		fmt = "%ld";
-	else if (strcmp(type, "unsigned long") == 0)
-		fmt = "%lu";
-	else if (strcmp(type, "pid_t") == 0)
-		fmt = "%d";
-	else if (strcmp(type, "gfp_t") == 0)
-		fmt = "%x";
-	else if (synth_field_is_string(type))
-		fmt = "%s";
-
-	return fmt;
-}
-
-static void print_synth_event_num_val(struct trace_seq *s,
-				      char *print_fmt, char *name,
-				      int size, u64 val, char *space)
-{
-	switch (size) {
-	case 1:
-		trace_seq_printf(s, print_fmt, name, (u8)val, space);
-		break;
-
-	case 2:
-		trace_seq_printf(s, print_fmt, name, (u16)val, space);
-		break;
-
-	case 4:
-		trace_seq_printf(s, print_fmt, name, (u32)val, space);
-		break;
-
-	default:
-		trace_seq_printf(s, print_fmt, name, val, space);
-		break;
-	}
-}
-
-static enum print_line_t print_synth_event(struct trace_iterator *iter,
-					   int flags,
-					   struct trace_event *event)
-{
-	struct trace_array *tr = iter->tr;
-	struct trace_seq *s = &iter->seq;
-	struct synth_trace_event *entry;
-	struct synth_event *se;
-	unsigned int i, n_u64;
-	char print_fmt[32];
-	const char *fmt;
-
-	entry = (struct synth_trace_event *)iter->ent;
-	se = container_of(event, struct synth_event, call.event);
-
-	trace_seq_printf(s, "%s: ", se->name);
-
-	for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
-		if (trace_seq_has_overflowed(s))
-			goto end;
-
-		fmt = synth_field_fmt(se->fields[i]->type);
-
-		/* parameter types */
-		if (tr->trace_flags & TRACE_ITER_VERBOSE)
-			trace_seq_printf(s, "%s ", fmt);
-
-		snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
-
-		/* parameter values */
-		if (se->fields[i]->is_string) {
-			trace_seq_printf(s, print_fmt, se->fields[i]->name,
-					 (char *)&entry->fields[n_u64],
-					 i == se->n_fields - 1 ? "" : " ");
-			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
-		} else {
-			struct trace_print_flags __flags[] = {
-			    __def_gfpflag_names, {-1, NULL} };
-			char *space = (i == se->n_fields - 1 ? "" : " ");
-
-			print_synth_event_num_val(s, print_fmt,
-						  se->fields[i]->name,
-						  se->fields[i]->size,
-						  entry->fields[n_u64],
-						  space);
-
-			if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
-				trace_seq_puts(s, " (");
-				trace_print_flags_seq(s, "|",
-						      entry->fields[n_u64],
-						      __flags);
-				trace_seq_putc(s, ')');
-			}
-			n_u64++;
-		}
-	}
-end:
-	trace_seq_putc(s, '\n');
-
-	return trace_handle_return(s);
-}
-
-static struct trace_event_functions synth_event_funcs = {
-	.trace		= print_synth_event
-};
-
-static notrace void trace_event_raw_event_synth(void *__data,
-						u64 *var_ref_vals,
-						unsigned int *var_ref_idx)
-{
-	struct trace_event_file *trace_file = __data;
-	struct synth_trace_event *entry;
-	struct trace_event_buffer fbuffer;
-	struct ring_buffer *buffer;
-	struct synth_event *event;
-	unsigned int i, n_u64, val_idx;
-	int fields_size = 0;
-
-	event = trace_file->event_call->data;
-
-	if (trace_trigger_soft_disabled(trace_file))
-		return;
-
-	fields_size = event->n_u64 * sizeof(u64);
-
-	/*
-	 * Avoid ring buffer recursion detection, as this event
-	 * is being performed within another event.
-	 */
-	buffer = trace_file->tr->trace_buffer.buffer;
-	ring_buffer_nest_start(buffer);
-
-	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
-					   sizeof(*entry) + fields_size);
-	if (!entry)
-		goto out;
-
-	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
-		val_idx = var_ref_idx[i];
-		if (event->fields[i]->is_string) {
-			char *str_val = (char *)(long)var_ref_vals[val_idx];
-			char *str_field = (char *)&entry->fields[n_u64];
-
-			strscpy(str_field, str_val, STR_VAR_LEN_MAX);
-			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
-		} else {
-			struct synth_field *field = event->fields[i];
-			u64 val = var_ref_vals[val_idx];
-
-			switch (field->size) {
-			case 1:
-				*(u8 *)&entry->fields[n_u64] = (u8)val;
-				break;
-
-			case 2:
-				*(u16 *)&entry->fields[n_u64] = (u16)val;
-				break;
-
-			case 4:
-				*(u32 *)&entry->fields[n_u64] = (u32)val;
-				break;
-
-			default:
-				entry->fields[n_u64] = val;
-				break;
-			}
-			n_u64++;
-		}
-	}
-
-	trace_event_buffer_commit(&fbuffer);
-out:
-	ring_buffer_nest_end(buffer);
-}
-
-static void free_synth_event_print_fmt(struct trace_event_call *call)
-{
-	if (call) {
-		kfree(call->print_fmt);
-		call->print_fmt = NULL;
-	}
-}
-
-static int __set_synth_event_print_fmt(struct synth_event *event,
-				       char *buf, int len)
-{
-	const char *fmt;
-	int pos = 0;
-	int i;
-
-	/* When len=0, we just calculate the needed length */
-#define LEN_OR_ZERO (len ? len - pos : 0)
-
-	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
-	for (i = 0; i < event->n_fields; i++) {
-		fmt = synth_field_fmt(event->fields[i]->type);
-		pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
-				event->fields[i]->name, fmt,
-				i == event->n_fields - 1 ? "" : ", ");
-	}
-	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
-
-	for (i = 0; i < event->n_fields; i++) {
-		pos += snprintf(buf + pos, LEN_OR_ZERO,
-				", REC->%s", event->fields[i]->name);
-	}
-
-#undef LEN_OR_ZERO
-
-	/* return the length of print_fmt */
-	return pos;
-}
-
-static int set_synth_event_print_fmt(struct trace_event_call *call)
-{
-	struct synth_event *event = call->data;
-	char *print_fmt;
-	int len;
-
-	/* First: called with 0 length to calculate the needed length */
-	len = __set_synth_event_print_fmt(event, NULL, 0);
-
-	print_fmt = kmalloc(len + 1, GFP_KERNEL);
-	if (!print_fmt)
-		return -ENOMEM;
-
-	/* Second: actually write the @print_fmt */
-	__set_synth_event_print_fmt(event, print_fmt, len + 1);
-	call->print_fmt = print_fmt;
-
-	return 0;
-}
-
-static void free_synth_field(struct synth_field *field)
-{
-	kfree(field->type);
-	kfree(field->name);
-	kfree(field);
-}
-
-static struct synth_field *parse_synth_field(int argc, const char **argv,
-					     int *consumed)
-{
-	struct synth_field *field;
-	const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
-	int len, ret = 0;
-
-	if (field_type[0] == ';')
-		field_type++;
-
-	if (!strcmp(field_type, "unsigned")) {
-		if (argc < 3)
-			return ERR_PTR(-EINVAL);
-		prefix = "unsigned ";
-		field_type = argv[1];
-		field_name = argv[2];
-		*consumed = 3;
-	} else {
-		field_name = argv[1];
-		*consumed = 2;
-	}
-
-	field = kzalloc(sizeof(*field), GFP_KERNEL);
-	if (!field)
-		return ERR_PTR(-ENOMEM);
-
-	len = strlen(field_name);
-	array = strchr(field_name, '[');
-	if (array)
-		len -= strlen(array);
-	else if (field_name[len - 1] == ';')
-		len--;
-
-	field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
-	if (!field->name) {
-		ret = -ENOMEM;
-		goto free;
-	}
-
-	if (field_type[0] == ';')
-		field_type++;
-	len = strlen(field_type) + 1;
-	if (array)
-		len += strlen(array);
-	if (prefix)
-		len += strlen(prefix);
-
-	field->type = kzalloc(len, GFP_KERNEL);
-	if (!field->type) {
-		ret = -ENOMEM;
-		goto free;
-	}
-	if (prefix)
-		strcat(field->type, prefix);
-	strcat(field->type, field_type);
-	if (array) {
-		strcat(field->type, array);
-		if (field->type[len - 1] == ';')
-			field->type[len - 1] = '\0';
-	}
-
-	field->size = synth_field_size(field->type);
-	if (!field->size) {
-		ret = -EINVAL;
-		goto free;
-	}
-
-	if (synth_field_is_string(field->type))
-		field->is_string = true;
-
-	field->is_signed = synth_field_signed(field->type);
-
- out:
-	return field;
- free:
-	free_synth_field(field);
-	field = ERR_PTR(ret);
-	goto out;
-}
-
-static void free_synth_tracepoint(struct tracepoint *tp)
-{
-	if (!tp)
-		return;
-
-	kfree(tp->name);
-	kfree(tp);
-}
-
-static struct tracepoint *alloc_synth_tracepoint(char *name)
-{
-	struct tracepoint *tp;
-
-	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
-	if (!tp)
-		return ERR_PTR(-ENOMEM);
-
-	tp->name = kstrdup(name, GFP_KERNEL);
-	if (!tp->name) {
-		kfree(tp);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	return tp;
-}
-
 typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
 				    unsigned int *var_ref_idx);
 
@@ -1168,139 +608,6 @@
 	}
 }
 
-static struct synth_event *find_synth_event(const char *name)
-{
-	struct dyn_event *pos;
-	struct synth_event *event;
-
-	for_each_dyn_event(pos) {
-		if (!is_synth_event(pos))
-			continue;
-		event = to_synth_event(pos);
-		if (strcmp(event->name, name) == 0)
-			return event;
-	}
-
-	return NULL;
-}
-
-static int register_synth_event(struct synth_event *event)
-{
-	struct trace_event_call *call = &event->call;
-	int ret = 0;
-
-	event->call.class = &event->class;
-	event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
-	if (!event->class.system) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	event->tp = alloc_synth_tracepoint(event->name);
-	if (IS_ERR(event->tp)) {
-		ret = PTR_ERR(event->tp);
-		event->tp = NULL;
-		goto out;
-	}
-
-	INIT_LIST_HEAD(&call->class->fields);
-	call->event.funcs = &synth_event_funcs;
-	call->class->define_fields = synth_event_define_fields;
-
-	ret = register_trace_event(&call->event);
-	if (!ret) {
-		ret = -ENODEV;
-		goto out;
-	}
-	call->flags = TRACE_EVENT_FL_TRACEPOINT;
-	call->class->reg = trace_event_reg;
-	call->class->probe = trace_event_raw_event_synth;
-	call->data = event;
-	call->tp = event->tp;
-
-	ret = trace_add_event_call(call);
-	if (ret) {
-		pr_warn("Failed to register synthetic event: %s\n",
-			trace_event_name(call));
-		goto err;
-	}
-
-	ret = set_synth_event_print_fmt(call);
-	if (ret < 0) {
-		trace_remove_event_call(call);
-		goto err;
-	}
- out:
-	return ret;
- err:
-	unregister_trace_event(&call->event);
-	goto out;
-}
-
-static int unregister_synth_event(struct synth_event *event)
-{
-	struct trace_event_call *call = &event->call;
-	int ret;
-
-	ret = trace_remove_event_call(call);
-
-	return ret;
-}
-
-static void free_synth_event(struct synth_event *event)
-{
-	unsigned int i;
-
-	if (!event)
-		return;
-
-	for (i = 0; i < event->n_fields; i++)
-		free_synth_field(event->fields[i]);
-
-	kfree(event->fields);
-	kfree(event->name);
-	kfree(event->class.system);
-	free_synth_tracepoint(event->tp);
-	free_synth_event_print_fmt(&event->call);
-	kfree(event);
-}
-
-static struct synth_event *alloc_synth_event(const char *name, int n_fields,
-					     struct synth_field **fields)
-{
-	struct synth_event *event;
-	unsigned int i;
-
-	event = kzalloc(sizeof(*event), GFP_KERNEL);
-	if (!event) {
-		event = ERR_PTR(-ENOMEM);
-		goto out;
-	}
-
-	event->name = kstrdup(name, GFP_KERNEL);
-	if (!event->name) {
-		kfree(event);
-		event = ERR_PTR(-ENOMEM);
-		goto out;
-	}
-
-	event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
-	if (!event->fields) {
-		free_synth_event(event);
-		event = ERR_PTR(-ENOMEM);
-		goto out;
-	}
-
-	dyn_event_init(&event->devent, &synth_event_ops);
-
-	for (i = 0; i < n_fields; i++)
-		event->fields[i] = fields[i];
-
-	event->n_fields = n_fields;
- out:
-	return event;
-}
-
 static void action_trace(struct hist_trigger_data *hist_data,
 			 struct tracing_map_elt *elt, void *rec,
 			 struct ring_buffer_event *rbe, void *key,
@@ -1316,219 +623,6 @@
 	struct hist_trigger_data *hist_data;
 };
 
-static int __create_synth_event(int argc, const char *name, const char **argv)
-{
-	struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
-	struct synth_event *event = NULL;
-	int i, consumed = 0, n_fields = 0, ret = 0;
-
-	/*
-	 * Argument syntax:
-	 *  - Add synthetic event: <event_name> field[;field] ...
-	 *  - Remove synthetic event: !<event_name> field[;field] ...
-	 *      where 'field' = type field_name
-	 */
-
-	if (name[0] == '\0' || argc < 1)
-		return -EINVAL;
-
-	mutex_lock(&event_mutex);
-
-	event = find_synth_event(name);
-	if (event) {
-		ret = -EEXIST;
-		goto out;
-	}
-
-	for (i = 0; i < argc - 1; i++) {
-		if (strcmp(argv[i], ";") == 0)
-			continue;
-		if (n_fields == SYNTH_FIELDS_MAX) {
-			ret = -EINVAL;
-			goto err;
-		}
-
-		field = parse_synth_field(argc - i, &argv[i], &consumed);
-		if (IS_ERR(field)) {
-			ret = PTR_ERR(field);
-			goto err;
-		}
-		fields[n_fields++] = field;
-		i += consumed - 1;
-	}
-
-	if (i < argc && strcmp(argv[i], ";") != 0) {
-		ret = -EINVAL;
-		goto err;
-	}
-
-	event = alloc_synth_event(name, n_fields, fields);
-	if (IS_ERR(event)) {
-		ret = PTR_ERR(event);
-		event = NULL;
-		goto err;
-	}
-	ret = register_synth_event(event);
-	if (!ret)
-		dyn_event_add(&event->devent);
-	else
-		free_synth_event(event);
- out:
-	mutex_unlock(&event_mutex);
-
-	return ret;
- err:
-	for (i = 0; i < n_fields; i++)
-		free_synth_field(fields[i]);
-
-	goto out;
-}
-
-static int create_or_delete_synth_event(int argc, char **argv)
-{
-	const char *name = argv[0];
-	struct synth_event *event = NULL;
-	int ret;
-
-	/* trace_run_command() ensures argc != 0 */
-	if (name[0] == '!') {
-		mutex_lock(&event_mutex);
-		event = find_synth_event(name + 1);
-		if (event) {
-			if (event->ref)
-				ret = -EBUSY;
-			else {
-				ret = unregister_synth_event(event);
-				if (!ret) {
-					dyn_event_remove(&event->devent);
-					free_synth_event(event);
-				}
-			}
-		} else
-			ret = -ENOENT;
-		mutex_unlock(&event_mutex);
-		return ret;
-	}
-
-	ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
-	return ret == -ECANCELED ? -EINVAL : ret;
-}
-
-static int synth_event_create(int argc, const char **argv)
-{
-	const char *name = argv[0];
-	int len;
-
-	if (name[0] != 's' || name[1] != ':')
-		return -ECANCELED;
-	name += 2;
-
-	/* This interface accepts group name prefix */
-	if (strchr(name, '/')) {
-		len = str_has_prefix(name, SYNTH_SYSTEM "/");
-		if (len == 0)
-			return -EINVAL;
-		name += len;
-	}
-	return __create_synth_event(argc - 1, name, argv + 1);
-}
-
-static int synth_event_release(struct dyn_event *ev)
-{
-	struct synth_event *event = to_synth_event(ev);
-	int ret;
-
-	if (event->ref)
-		return -EBUSY;
-
-	ret = unregister_synth_event(event);
-	if (ret)
-		return ret;
-
-	dyn_event_remove(ev);
-	free_synth_event(event);
-	return 0;
-}
-
-static int __synth_event_show(struct seq_file *m, struct synth_event *event)
-{
-	struct synth_field *field;
-	unsigned int i;
-
-	seq_printf(m, "%s\t", event->name);
-
-	for (i = 0; i < event->n_fields; i++) {
-		field = event->fields[i];
-
-		/* parameter values */
-		seq_printf(m, "%s %s%s", field->type, field->name,
-			   i == event->n_fields - 1 ? "" : "; ");
-	}
-
-	seq_putc(m, '\n');
-
-	return 0;
-}
-
-static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
-{
-	struct synth_event *event = to_synth_event(ev);
-
-	seq_printf(m, "s:%s/", event->class.system);
-
-	return __synth_event_show(m, event);
-}
-
-static int synth_events_seq_show(struct seq_file *m, void *v)
-{
-	struct dyn_event *ev = v;
-
-	if (!is_synth_event(ev))
-		return 0;
-
-	return __synth_event_show(m, to_synth_event(ev));
-}
-
-static const struct seq_operations synth_events_seq_op = {
-	.start	= dyn_event_seq_start,
-	.next	= dyn_event_seq_next,
-	.stop	= dyn_event_seq_stop,
-	.show	= synth_events_seq_show,
-};
-
-static int synth_events_open(struct inode *inode, struct file *file)
-{
-	int ret;
-
-	ret = security_locked_down(LOCKDOWN_TRACEFS);
-	if (ret)
-		return ret;
-
-	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
-		ret = dyn_events_release_all(&synth_event_ops);
-		if (ret < 0)
-			return ret;
-	}
-
-	return seq_open(file, &synth_events_seq_op);
-}
-
-static ssize_t synth_events_write(struct file *file,
-				  const char __user *buffer,
-				  size_t count, loff_t *ppos)
-{
-	return trace_parse_run_command(file, buffer, count, ppos,
-				       create_or_delete_synth_event);
-}
-
-static const struct file_operations synth_events_fops = {
-	.open           = synth_events_open,
-	.write		= synth_events_write,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.release        = seq_release,
-};
-
 static u64 hist_field_timestamp(struct hist_field *hist_field,
 				struct tracing_map_elt *elt,
 				struct ring_buffer_event *rbe,
@@ -2208,6 +1302,7 @@
 		if (rhs) {
 			if (!strlen(++rhs)) {
 				ret = -EINVAL;
+				hist_err(tr, HIST_ERR_EMPTY_ASSIGNMENT, errpos(str));
 				goto free;
 			}
 			ret = parse_assignment(tr, str, attrs);
@@ -2305,7 +1400,14 @@
 		}
 	}
 
-	n_str = hist_data->n_field_var_str + hist_data->n_save_var_str;
+	n_str = hist_data->n_field_var_str + hist_data->n_save_var_str +
+		hist_data->n_var_str;
+	if (n_str > SYNTH_FIELDS_MAX) {
+		hist_elt_data_free(elt_data);
+		return -EINVAL;
+	}
+
+	BUILD_BUG_ON(STR_VAR_LEN_MAX & (sizeof(u64) - 1));
 
 	size = STR_VAR_LEN_MAX;
 
@@ -2582,9 +1684,10 @@
 		if (!hist_field->type)
 			goto free;
 
-		if (field->filter_type == FILTER_STATIC_STRING)
+		if (field->filter_type == FILTER_STATIC_STRING) {
 			hist_field->fn = hist_field_string;
-		else if (field->filter_type == FILTER_DYN_STRING)
+			hist_field->size = field->size;
+		} else if (field->filter_type == FILTER_DYN_STRING)
 			hist_field->fn = hist_field_dynstring;
 		else
 			hist_field->fn = hist_field_pstring;
@@ -2882,9 +1985,9 @@
 			/*
 			 * For backward compatibility, if field_name
 			 * was "cpu", then we treat this the same as
-			 * common_cpu.
+			 * common_cpu. This also works for "CPU".
 			 */
-			if (strcmp(field_name, "cpu") == 0) {
+			if (field && field->filter_type == FILTER_CPU) {
 				*flags |= HIST_FIELD_FL_CPU;
 			} else {
 				hist_err(tr, HIST_ERR_FIELD_NOT_FOUND,
@@ -3051,6 +2154,8 @@
 		(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
 	expr->fn = hist_field_unary_minus;
 	expr->operands[0] = operand1;
+	expr->size = operand1->size;
+	expr->is_signed = operand1->is_signed;
 	expr->operator = FIELD_OP_UNARY_MINUS;
 	expr->name = expr_str(expr, 0);
 	expr->type = kstrdup(operand1->type, GFP_KERNEL);
@@ -3190,6 +2295,7 @@
 
 	/* The operand sizes should be the same, so just pick one */
 	expr->size = operand1->size;
+	expr->is_signed = operand1->is_signed;
 
 	expr->operator = field_op;
 	expr->name = expr_str(expr, 0);
@@ -3521,8 +2627,10 @@
 		if (val->flags & HIST_FIELD_FL_STRING) {
 			char *str = elt_data->field_var_str[j++];
 			char *val_str = (char *)(uintptr_t)var_val;
+			unsigned int size;
 
-			strscpy(str, val_str, STR_VAR_LEN_MAX);
+			size = min(val->size, STR_VAR_LEN_MAX);
+			strscpy(str, val_str, size);
 			var_val = (u64)(uintptr_t)str;
 		}
 		tracing_map_set_var(elt, var_idx, var_val);
@@ -4228,8 +3336,20 @@
 
 	field = event->fields[field_pos];
 
-	if (strcmp(field->type, hist_field->type) != 0)
-		return -EINVAL;
+	/*
+	 * A dynamic string synth field can accept static or
+	 * dynamic. A static string synth field can only accept a
+	 * same-sized static string, which is checked for later.
+	 */
+	if (strstr(hist_field->type, "char[") && field->is_string
+	    && field->is_dynamic)
+		return 0;
+
+	if (strcmp(field->type, hist_field->type) != 0) {
+		if (field->size != hist_field->size ||
+		    (!field->is_string && field->is_signed != hist_field->is_signed))
+			return -EINVAL;
+	}
 
 	return 0;
 }
@@ -4389,6 +3509,7 @@
 
 			var_ref_idx = find_var_ref_idx(hist_data, var_ref);
 			if (WARN_ON(var_ref_idx < 0)) {
+				kfree(p);
 				ret = var_ref_idx;
 				goto err;
 			}
@@ -4599,6 +3720,7 @@
 {
 	struct trace_array *tr = hist_data->event_file->tr;
 	unsigned long flags = 0;
+	int ret;
 
 	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
 		return -EINVAL;
@@ -4613,7 +3735,12 @@
 	if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))
 		return -EINVAL;
 
-	return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
+	ret = __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
+
+	if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_STRING)
+		hist_data->fields[val_idx]->var_str_idx = hist_data->n_var_str++;
+
+	return ret;
 }
 
 static int create_val_fields(struct hist_trigger_data *hist_data,
@@ -4855,7 +3982,7 @@
 	return ret;
 }
 
-static int is_descending(const char *str)
+static int is_descending(struct trace_array *tr, const char *str)
 {
 	if (!str)
 		return 0;
@@ -4866,11 +3993,14 @@
 	if (strcmp(str, "ascending") == 0)
 		return 0;
 
+	hist_err(tr, HIST_ERR_INVALID_SORT_MODIFIER, errpos((char *)str));
+
 	return -EINVAL;
 }
 
 static int create_sort_keys(struct hist_trigger_data *hist_data)
 {
+	struct trace_array *tr = hist_data->event_file->tr;
 	char *fields_str = hist_data->attrs->sort_key_str;
 	struct tracing_map_sort_key *sort_key;
 	int descending, ret = 0;
@@ -4894,10 +4024,12 @@
 
 		if (!*field_str) {
 			ret = -EINVAL;
+			hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
 			break;
 		}
 
 		if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
+			hist_err(tr, HIST_ERR_TOO_MANY_SORT_FIELDS, errpos("sort="));
 			ret = -EINVAL;
 			break;
 		}
@@ -4905,11 +4037,12 @@
 		field_name = strsep(&field_str, ".");
 		if (!field_name || !*field_name) {
 			ret = -EINVAL;
+			hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
 			break;
 		}
 
 		if (strcmp(field_name, "hitcount") == 0) {
-			descending = is_descending(field_str);
+			descending = is_descending(tr, field_str);
 			if (descending < 0) {
 				ret = descending;
 				break;
@@ -4931,7 +4064,7 @@
 
 			if (strcmp(field_name, test_name) == 0) {
 				sort_key->field_idx = idx;
-				descending = is_descending(field_str);
+				descending = is_descending(tr, field_str);
 				if (descending < 0) {
 					ret = descending;
 					goto out;
@@ -4942,6 +4075,7 @@
 		}
 		if (j == hist_data->n_fields) {
 			ret = -EINVAL;
+			hist_err(tr, HIST_ERR_INVALID_SORT_FIELD, errpos(field_name));
 			break;
 		}
 	}
@@ -5231,7 +4365,7 @@
 
 			if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
 				cmp_fn = tracing_map_cmp_none;
-			else if (!field)
+			else if (!field || hist_field->flags & HIST_FIELD_FL_CPU)
 				cmp_fn = tracing_map_cmp_num(hist_field->size,
 							     hist_field->is_signed);
 			else if (is_string_field(field))
@@ -5333,6 +4467,25 @@
 		hist_val = hist_field->fn(hist_field, elt, rbe, rec);
 		if (hist_field->flags & HIST_FIELD_FL_VAR) {
 			var_idx = hist_field->var.idx;
+
+			if (hist_field->flags & HIST_FIELD_FL_STRING) {
+				unsigned int str_start, var_str_idx, idx;
+				char *str, *val_str;
+				unsigned int size;
+
+				str_start = hist_data->n_field_var_str +
+					hist_data->n_save_var_str;
+				var_str_idx = hist_field->var_str_idx;
+				idx = str_start + var_str_idx;
+
+				str = elt_data->field_var_str[idx];
+				val_str = (char *)(uintptr_t)hist_val;
+
+				size = min(hist_field->size, STR_VAR_LEN_MAX);
+				strscpy(str, val_str, size);
+
+				hist_val = (u64)(uintptr_t)str;
+			}
 			tracing_map_set_var(elt, var_idx, hist_val);
 			continue;
 		}
@@ -5667,6 +4820,279 @@
 	.release = single_release,
 };
 
+#ifdef CONFIG_HIST_TRIGGERS_DEBUG
+static void hist_field_debug_show_flags(struct seq_file *m,
+					unsigned long flags)
+{
+	seq_puts(m, "      flags:\n");
+
+	if (flags & HIST_FIELD_FL_KEY)
+		seq_puts(m, "        HIST_FIELD_FL_KEY\n");
+	else if (flags & HIST_FIELD_FL_HITCOUNT)
+		seq_puts(m, "        VAL: HIST_FIELD_FL_HITCOUNT\n");
+	else if (flags & HIST_FIELD_FL_VAR)
+		seq_puts(m, "        HIST_FIELD_FL_VAR\n");
+	else if (flags & HIST_FIELD_FL_VAR_REF)
+		seq_puts(m, "        HIST_FIELD_FL_VAR_REF\n");
+	else
+		seq_puts(m, "        VAL: normal u64 value\n");
+
+	if (flags & HIST_FIELD_FL_ALIAS)
+		seq_puts(m, "        HIST_FIELD_FL_ALIAS\n");
+}
+
+static int hist_field_debug_show(struct seq_file *m,
+				 struct hist_field *field, unsigned long flags)
+{
+	if ((field->flags & flags) != flags) {
+		seq_printf(m, "ERROR: bad flags - %lx\n", flags);
+		return -EINVAL;
+	}
+
+	hist_field_debug_show_flags(m, field->flags);
+	if (field->field)
+		seq_printf(m, "      ftrace_event_field name: %s\n",
+			   field->field->name);
+
+	if (field->flags & HIST_FIELD_FL_VAR) {
+		seq_printf(m, "      var.name: %s\n", field->var.name);
+		seq_printf(m, "      var.idx (into tracing_map_elt.vars[]): %u\n",
+			   field->var.idx);
+	}
+
+	if (field->flags & HIST_FIELD_FL_ALIAS)
+		seq_printf(m, "      var_ref_idx (into hist_data->var_refs[]): %u\n",
+			   field->var_ref_idx);
+
+	if (field->flags & HIST_FIELD_FL_VAR_REF) {
+		seq_printf(m, "      name: %s\n", field->name);
+		seq_printf(m, "      var.idx (into tracing_map_elt.vars[]): %u\n",
+			   field->var.idx);
+		seq_printf(m, "      var.hist_data: %p\n", field->var.hist_data);
+		seq_printf(m, "      var_ref_idx (into hist_data->var_refs[]): %u\n",
+			   field->var_ref_idx);
+		if (field->system)
+			seq_printf(m, "      system: %s\n", field->system);
+		if (field->event_name)
+			seq_printf(m, "      event_name: %s\n", field->event_name);
+	}
+
+	seq_printf(m, "      type: %s\n", field->type);
+	seq_printf(m, "      size: %u\n", field->size);
+	seq_printf(m, "      is_signed: %u\n", field->is_signed);
+
+	return 0;
+}
+
+static int field_var_debug_show(struct seq_file *m,
+				struct field_var *field_var, unsigned int i,
+				bool save_vars)
+{
+	const char *vars_name = save_vars ? "save_vars" : "field_vars";
+	struct hist_field *field;
+	int ret = 0;
+
+	seq_printf(m, "\n    hist_data->%s[%d]:\n", vars_name, i);
+
+	field = field_var->var;
+
+	seq_printf(m, "\n      %s[%d].var:\n", vars_name, i);
+
+	hist_field_debug_show_flags(m, field->flags);
+	seq_printf(m, "      var.name: %s\n", field->var.name);
+	seq_printf(m, "      var.idx (into tracing_map_elt.vars[]): %u\n",
+		   field->var.idx);
+
+	field = field_var->val;
+
+	seq_printf(m, "\n      %s[%d].val:\n", vars_name, i);
+	if (field->field)
+		seq_printf(m, "      ftrace_event_field name: %s\n",
+			   field->field->name);
+	else {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	seq_printf(m, "      type: %s\n", field->type);
+	seq_printf(m, "      size: %u\n", field->size);
+	seq_printf(m, "      is_signed: %u\n", field->is_signed);
+out:
+	return ret;
+}
+
+static int hist_action_debug_show(struct seq_file *m,
+				  struct action_data *data, int i)
+{
+	int ret = 0;
+
+	if (data->handler == HANDLER_ONMAX ||
+	    data->handler == HANDLER_ONCHANGE) {
+		seq_printf(m, "\n    hist_data->actions[%d].track_data.var_ref:\n", i);
+		ret = hist_field_debug_show(m, data->track_data.var_ref,
+					    HIST_FIELD_FL_VAR_REF);
+		if (ret)
+			goto out;
+
+		seq_printf(m, "\n    hist_data->actions[%d].track_data.track_var:\n", i);
+		ret = hist_field_debug_show(m, data->track_data.track_var,
+					    HIST_FIELD_FL_VAR);
+		if (ret)
+			goto out;
+	}
+
+	if (data->handler == HANDLER_ONMATCH) {
+		seq_printf(m, "\n    hist_data->actions[%d].match_data.event_system: %s\n",
+			   i, data->match_data.event_system);
+		seq_printf(m, "    hist_data->actions[%d].match_data.event: %s\n",
+			   i, data->match_data.event);
+	}
+out:
+	return ret;
+}
+
+static int hist_actions_debug_show(struct seq_file *m,
+				   struct hist_trigger_data *hist_data)
+{
+	int i, ret = 0;
+
+	if (hist_data->n_actions)
+		seq_puts(m, "\n  action tracking variables (for onmax()/onchange()/onmatch()):\n");
+
+	for (i = 0; i < hist_data->n_actions; i++) {
+		struct action_data *action = hist_data->actions[i];
+
+		ret = hist_action_debug_show(m, action, i);
+		if (ret)
+			goto out;
+	}
+
+	if (hist_data->n_save_vars)
+		seq_puts(m, "\n  save action variables (save() params):\n");
+
+	for (i = 0; i < hist_data->n_save_vars; i++) {
+		ret = field_var_debug_show(m, hist_data->save_vars[i], i, true);
+		if (ret)
+			goto out;
+	}
+out:
+	return ret;
+}
+
+static void hist_trigger_debug_show(struct seq_file *m,
+				    struct event_trigger_data *data, int n)
+{
+	struct hist_trigger_data *hist_data;
+	int i, ret;
+
+	if (n > 0)
+		seq_puts(m, "\n\n");
+
+	seq_puts(m, "# event histogram\n#\n# trigger info: ");
+	data->ops->print(m, data->ops, data);
+	seq_puts(m, "#\n\n");
+
+	hist_data = data->private_data;
+
+	seq_printf(m, "hist_data: %p\n\n", hist_data);
+	seq_printf(m, "  n_vals: %u\n", hist_data->n_vals);
+	seq_printf(m, "  n_keys: %u\n", hist_data->n_keys);
+	seq_printf(m, "  n_fields: %u\n", hist_data->n_fields);
+
+	seq_puts(m, "\n  val fields:\n\n");
+
+	seq_puts(m, "    hist_data->fields[0]:\n");
+	ret = hist_field_debug_show(m, hist_data->fields[0],
+				    HIST_FIELD_FL_HITCOUNT);
+	if (ret)
+		return;
+
+	for (i = 1; i < hist_data->n_vals; i++) {
+		seq_printf(m, "\n    hist_data->fields[%d]:\n", i);
+		ret = hist_field_debug_show(m, hist_data->fields[i], 0);
+		if (ret)
+			return;
+	}
+
+	seq_puts(m, "\n  key fields:\n");
+
+	for (i = hist_data->n_vals; i < hist_data->n_fields; i++) {
+		seq_printf(m, "\n    hist_data->fields[%d]:\n", i);
+		ret = hist_field_debug_show(m, hist_data->fields[i],
+					    HIST_FIELD_FL_KEY);
+		if (ret)
+			return;
+	}
+
+	if (hist_data->n_var_refs)
+		seq_puts(m, "\n  variable reference fields:\n");
+
+	for (i = 0; i < hist_data->n_var_refs; i++) {
+		seq_printf(m, "\n    hist_data->var_refs[%d]:\n", i);
+		ret = hist_field_debug_show(m, hist_data->var_refs[i],
+					    HIST_FIELD_FL_VAR_REF);
+		if (ret)
+			return;
+	}
+
+	if (hist_data->n_field_vars)
+		seq_puts(m, "\n  field variables:\n");
+
+	for (i = 0; i < hist_data->n_field_vars; i++) {
+		ret = field_var_debug_show(m, hist_data->field_vars[i], i, false);
+		if (ret)
+			return;
+	}
+
+	ret = hist_actions_debug_show(m, hist_data);
+	if (ret)
+		return;
+}
+
+static int hist_debug_show(struct seq_file *m, void *v)
+{
+	struct event_trigger_data *data;
+	struct trace_event_file *event_file;
+	int n = 0, ret = 0;
+
+	mutex_lock(&event_mutex);
+
+	event_file = event_file_data(m->private);
+	if (unlikely(!event_file)) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	list_for_each_entry(data, &event_file->triggers, list) {
+		if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
+			hist_trigger_debug_show(m, data, n++);
+	}
+
+ out_unlock:
+	mutex_unlock(&event_mutex);
+
+	return ret;
+}
+
+static int event_hist_debug_open(struct inode *inode, struct file *file)
+{
+	int ret;
+
+	ret = security_locked_down(LOCKDOWN_TRACEFS);
+	if (ret)
+		return ret;
+
+	return single_open(file, hist_debug_show, file);
+}
+
+const struct file_operations event_hist_debug_fops = {
+	.open = event_hist_debug_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+#endif
+
 static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
 {
 	const char *field_name = hist_field_name(hist_field, 0);
@@ -6569,37 +5995,3 @@
 
 	return ret;
 }
-
-static __init int trace_events_hist_init(void)
-{
-	struct dentry *entry = NULL;
-	struct dentry *d_tracer;
-	int err = 0;
-
-	err = dyn_event_register(&synth_event_ops);
-	if (err) {
-		pr_warn("Could not register synth_event_ops\n");
-		return err;
-	}
-
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer)) {
-		err = PTR_ERR(d_tracer);
-		goto err;
-	}
-
-	entry = tracefs_create_file("synthetic_events", 0644, d_tracer,
-				    NULL, &synth_events_fops);
-	if (!entry) {
-		err = -ENODEV;
-		goto err;
-	}
-
-	return err;
- err:
-	pr_warn("Could not create tracefs 'synthetic_events' entry\n");
-
-	return err;
-}
-
-fs_initcall(trace_events_hist_init);
diff --git a/kernel/trace/trace_events_inject.c b/kernel/trace/trace_events_inject.c
new file mode 100644
index 0000000..22bcf7c
--- /dev/null
+++ b/kernel/trace/trace_events_inject.c
@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * trace_events_inject - trace event injection
+ *
+ * Copyright (C) 2019 Cong Wang <cwang@twitter.com>
+ */
+
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/rculist.h>
+
+#include "trace.h"
+
+static int
+trace_inject_entry(struct trace_event_file *file, void *rec, int len)
+{
+	struct trace_event_buffer fbuffer;
+	int written = 0;
+	void *entry;
+
+	rcu_read_lock_sched();
+	entry = trace_event_buffer_reserve(&fbuffer, file, len);
+	if (entry) {
+		memcpy(entry, rec, len);
+		written = len;
+		trace_event_buffer_commit(&fbuffer);
+	}
+	rcu_read_unlock_sched();
+
+	return written;
+}
+
+static int
+parse_field(char *str, struct trace_event_call *call,
+	    struct ftrace_event_field **pf, u64 *pv)
+{
+	struct ftrace_event_field *field;
+	char *field_name;
+	int s, i = 0;
+	int len;
+	u64 val;
+
+	if (!str[i])
+		return 0;
+	/* First find the field to associate to */
+	while (isspace(str[i]))
+		i++;
+	s = i;
+	while (isalnum(str[i]) || str[i] == '_')
+		i++;
+	len = i - s;
+	if (!len)
+		return -EINVAL;
+
+	field_name = kmemdup_nul(str + s, len, GFP_KERNEL);
+	if (!field_name)
+		return -ENOMEM;
+	field = trace_find_event_field(call, field_name);
+	kfree(field_name);
+	if (!field)
+		return -ENOENT;
+
+	*pf = field;
+	while (isspace(str[i]))
+		i++;
+	if (str[i] != '=')
+		return -EINVAL;
+	i++;
+	while (isspace(str[i]))
+		i++;
+	s = i;
+	if (isdigit(str[i]) || str[i] == '-') {
+		char *num, c;
+		int ret;
+
+		/* Make sure the field is not a string */
+		if (is_string_field(field))
+			return -EINVAL;
+
+		if (str[i] == '-')
+			i++;
+
+		/* We allow 0xDEADBEEF */
+		while (isalnum(str[i]))
+			i++;
+		num = str + s;
+		c = str[i];
+		if (c != '\0' && !isspace(c))
+			return -EINVAL;
+		str[i] = '\0';
+		/* Make sure it is a value */
+		if (field->is_signed)
+			ret = kstrtoll(num, 0, &val);
+		else
+			ret = kstrtoull(num, 0, &val);
+		str[i] = c;
+		if (ret)
+			return ret;
+
+		*pv = val;
+		return i;
+	} else if (str[i] == '\'' || str[i] == '"') {
+		char q = str[i];
+
+		/* Make sure the field is OK for strings */
+		if (!is_string_field(field))
+			return -EINVAL;
+
+		for (i++; str[i]; i++) {
+			if (str[i] == '\\' && str[i + 1]) {
+				i++;
+				continue;
+			}
+			if (str[i] == q)
+				break;
+		}
+		if (!str[i])
+			return -EINVAL;
+
+		/* Skip quotes */
+		s++;
+		len = i - s;
+		if (len >= MAX_FILTER_STR_VAL)
+			return -EINVAL;
+
+		*pv = (unsigned long)(str + s);
+		str[i] = 0;
+		/* go past the last quote */
+		i++;
+		return i;
+	}
+
+	return -EINVAL;
+}
+
+static int trace_get_entry_size(struct trace_event_call *call)
+{
+	struct ftrace_event_field *field;
+	struct list_head *head;
+	int size = 0;
+
+	head = trace_get_fields(call);
+	list_for_each_entry(field, head, link) {
+		if (field->size + field->offset > size)
+			size = field->size + field->offset;
+	}
+
+	return size;
+}
+
+static void *trace_alloc_entry(struct trace_event_call *call, int *size)
+{
+	int entry_size = trace_get_entry_size(call);
+	struct ftrace_event_field *field;
+	struct list_head *head;
+	void *entry = NULL;
+
+	/* We need an extra '\0' at the end. */
+	entry = kzalloc(entry_size + 1, GFP_KERNEL);
+	if (!entry)
+		return NULL;
+
+	head = trace_get_fields(call);
+	list_for_each_entry(field, head, link) {
+		if (!is_string_field(field))
+			continue;
+		if (field->filter_type == FILTER_STATIC_STRING)
+			continue;
+		if (field->filter_type == FILTER_DYN_STRING) {
+			u32 *str_item;
+			int str_loc = entry_size & 0xffff;
+
+			str_item = (u32 *)(entry + field->offset);
+			*str_item = str_loc; /* string length is 0. */
+		} else {
+			char **paddr;
+
+			paddr = (char **)(entry + field->offset);
+			*paddr = "";
+		}
+	}
+
+	*size = entry_size + 1;
+	return entry;
+}
+
+#define INJECT_STRING "STATIC STRING CAN NOT BE INJECTED"
+
+/* Caller is responsible to free the *pentry. */
+static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
+{
+	struct ftrace_event_field *field;
+	unsigned long irq_flags;
+	void *entry = NULL;
+	int entry_size;
+	u64 val = 0;
+	int len;
+
+	entry = trace_alloc_entry(call, &entry_size);
+	*pentry = entry;
+	if (!entry)
+		return -ENOMEM;
+
+	local_save_flags(irq_flags);
+	tracing_generic_entry_update(entry, call->event.type, irq_flags,
+				     preempt_count());
+
+	while ((len = parse_field(str, call, &field, &val)) > 0) {
+		if (is_function_field(field))
+			return -EINVAL;
+
+		if (is_string_field(field)) {
+			char *addr = (char *)(unsigned long) val;
+
+			if (field->filter_type == FILTER_STATIC_STRING) {
+				strlcpy(entry + field->offset, addr, field->size);
+			} else if (field->filter_type == FILTER_DYN_STRING) {
+				int str_len = strlen(addr) + 1;
+				int str_loc = entry_size & 0xffff;
+				u32 *str_item;
+
+				entry_size += str_len;
+				*pentry = krealloc(entry, entry_size, GFP_KERNEL);
+				if (!*pentry) {
+					kfree(entry);
+					return -ENOMEM;
+				}
+				entry = *pentry;
+
+				strlcpy(entry + (entry_size - str_len), addr, str_len);
+				str_item = (u32 *)(entry + field->offset);
+				*str_item = (str_len << 16) | str_loc;
+			} else {
+				char **paddr;
+
+				paddr = (char **)(entry + field->offset);
+				*paddr = INJECT_STRING;
+			}
+		} else {
+			switch (field->size) {
+			case 1: {
+				u8 tmp = (u8) val;
+
+				memcpy(entry + field->offset, &tmp, 1);
+				break;
+			}
+			case 2: {
+				u16 tmp = (u16) val;
+
+				memcpy(entry + field->offset, &tmp, 2);
+				break;
+			}
+			case 4: {
+				u32 tmp = (u32) val;
+
+				memcpy(entry + field->offset, &tmp, 4);
+				break;
+			}
+			case 8:
+				memcpy(entry + field->offset, &val, 8);
+				break;
+			default:
+				return -EINVAL;
+			}
+		}
+
+		str += len;
+	}
+
+	if (len < 0)
+		return len;
+
+	return entry_size;
+}
+
+static ssize_t
+event_inject_write(struct file *filp, const char __user *ubuf, size_t cnt,
+		   loff_t *ppos)
+{
+	struct trace_event_call *call;
+	struct trace_event_file *file;
+	int err = -ENODEV, size;
+	void *entry = NULL;
+	char *buf;
+
+	if (cnt >= PAGE_SIZE)
+		return -EINVAL;
+
+	buf = memdup_user_nul(ubuf, cnt);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+	strim(buf);
+
+	mutex_lock(&event_mutex);
+	file = event_file_data(filp);
+	if (file) {
+		call = file->event_call;
+		size = parse_entry(buf, call, &entry);
+		if (size < 0)
+			err = size;
+		else
+			err = trace_inject_entry(file, entry, size);
+	}
+	mutex_unlock(&event_mutex);
+
+	kfree(entry);
+	kfree(buf);
+
+	if (err < 0)
+		return err;
+
+	*ppos += err;
+	return cnt;
+}
+
+static ssize_t
+event_inject_read(struct file *file, char __user *buf, size_t size,
+		  loff_t *ppos)
+{
+	return -EPERM;
+}
+
+const struct file_operations event_inject_fops = {
+	.open = tracing_open_generic,
+	.read = event_inject_read,
+	.write = event_inject_write,
+};
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
new file mode 100644
index 0000000..881df99
--- /dev/null
+++ b/kernel/trace/trace_events_synth.c
@@ -0,0 +1,2103 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * trace_events_synth - synthetic trace events
+ *
+ * Copyright (C) 2015, 2020 Tom Zanussi <tom.zanussi@linux.intel.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/security.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/stacktrace.h>
+#include <linux/rculist.h>
+#include <linux/tracefs.h>
+
+/* for gfp flag names */
+#include <linux/trace_events.h>
+#include <trace/events/mmflags.h>
+
+#include "trace_synth.h"
+
+#undef ERRORS
+#define ERRORS	\
+	C(BAD_NAME,		"Illegal name"),		\
+	C(CMD_INCOMPLETE,	"Incomplete command"),		\
+	C(EVENT_EXISTS,		"Event already exists"),	\
+	C(TOO_MANY_FIELDS,	"Too many fields"),		\
+	C(INCOMPLETE_TYPE,	"Incomplete type"),		\
+	C(INVALID_TYPE,		"Invalid type"),		\
+	C(INVALID_FIELD,	"Invalid field"),		\
+	C(CMD_TOO_LONG,		"Command too long"),
+
+#undef C
+#define C(a, b)		SYNTH_ERR_##a
+
+enum { ERRORS };
+
+#undef C
+#define C(a, b)		b
+
+static const char *err_text[] = { ERRORS };
+
+static char last_cmd[MAX_FILTER_STR_VAL];
+
+static int errpos(const char *str)
+{
+	return err_pos(last_cmd, str);
+}
+
+static void last_cmd_set(char *str)
+{
+	if (!str)
+		return;
+
+	strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);
+}
+
+static void synth_err(u8 err_type, u8 err_pos)
+{
+	tracing_log_err(NULL, "synthetic_events", last_cmd, err_text,
+			err_type, err_pos);
+}
+
+static int create_synth_event(int argc, const char **argv);
+static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
+static int synth_event_release(struct dyn_event *ev);
+static bool synth_event_is_busy(struct dyn_event *ev);
+static bool synth_event_match(const char *system, const char *event,
+			int argc, const char **argv, struct dyn_event *ev);
+
+static struct dyn_event_operations synth_event_ops = {
+	.create = create_synth_event,
+	.show = synth_event_show,
+	.is_busy = synth_event_is_busy,
+	.free = synth_event_release,
+	.match = synth_event_match,
+};
+
+static bool is_synth_event(struct dyn_event *ev)
+{
+	return ev->ops == &synth_event_ops;
+}
+
+static struct synth_event *to_synth_event(struct dyn_event *ev)
+{
+	return container_of(ev, struct synth_event, devent);
+}
+
+static bool synth_event_is_busy(struct dyn_event *ev)
+{
+	struct synth_event *event = to_synth_event(ev);
+
+	return event->ref != 0;
+}
+
+static bool synth_event_match(const char *system, const char *event,
+			int argc, const char **argv, struct dyn_event *ev)
+{
+	struct synth_event *sev = to_synth_event(ev);
+
+	return strcmp(sev->name, event) == 0 &&
+		(!system || strcmp(system, SYNTH_SYSTEM) == 0);
+}
+
+struct synth_trace_event {
+	struct trace_entry	ent;
+	u64			fields[];
+};
+
+static int synth_event_define_fields(struct trace_event_call *call)
+{
+	struct synth_trace_event trace;
+	int offset = offsetof(typeof(trace), fields);
+	struct synth_event *event = call->data;
+	unsigned int i, size, n_u64;
+	char *name, *type;
+	bool is_signed;
+	int ret = 0;
+
+	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+		size = event->fields[i]->size;
+		is_signed = event->fields[i]->is_signed;
+		type = event->fields[i]->type;
+		name = event->fields[i]->name;
+		ret = trace_define_field(call, type, name, offset, size,
+					 is_signed, FILTER_OTHER);
+		if (ret)
+			break;
+
+		event->fields[i]->offset = n_u64;
+
+		if (event->fields[i]->is_string && !event->fields[i]->is_dynamic) {
+			offset += STR_VAR_LEN_MAX;
+			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
+		} else {
+			offset += sizeof(u64);
+			n_u64++;
+		}
+	}
+
+	event->n_u64 = n_u64;
+
+	return ret;
+}
+
+static bool synth_field_signed(char *type)
+{
+	if (str_has_prefix(type, "u"))
+		return false;
+	if (strcmp(type, "gfp_t") == 0)
+		return false;
+
+	return true;
+}
+
+static int synth_field_is_string(char *type)
+{
+	if (strstr(type, "char[") != NULL)
+		return true;
+
+	return false;
+}
+
+static int synth_field_string_size(char *type)
+{
+	char buf[4], *end, *start;
+	unsigned int len;
+	int size, err;
+
+	start = strstr(type, "char[");
+	if (start == NULL)
+		return -EINVAL;
+	start += sizeof("char[") - 1;
+
+	end = strchr(type, ']');
+	if (!end || end < start || type + strlen(type) > end + 1)
+		return -EINVAL;
+
+	len = end - start;
+	if (len > 3)
+		return -EINVAL;
+
+	if (len == 0)
+		return 0; /* variable-length string */
+
+	strncpy(buf, start, len);
+	buf[len] = '\0';
+
+	err = kstrtouint(buf, 0, &size);
+	if (err)
+		return err;
+
+	if (size > STR_VAR_LEN_MAX)
+		return -EINVAL;
+
+	return size;
+}
+
+static int synth_field_size(char *type)
+{
+	int size = 0;
+
+	if (strcmp(type, "s64") == 0)
+		size = sizeof(s64);
+	else if (strcmp(type, "u64") == 0)
+		size = sizeof(u64);
+	else if (strcmp(type, "s32") == 0)
+		size = sizeof(s32);
+	else if (strcmp(type, "u32") == 0)
+		size = sizeof(u32);
+	else if (strcmp(type, "s16") == 0)
+		size = sizeof(s16);
+	else if (strcmp(type, "u16") == 0)
+		size = sizeof(u16);
+	else if (strcmp(type, "s8") == 0)
+		size = sizeof(s8);
+	else if (strcmp(type, "u8") == 0)
+		size = sizeof(u8);
+	else if (strcmp(type, "char") == 0)
+		size = sizeof(char);
+	else if (strcmp(type, "unsigned char") == 0)
+		size = sizeof(unsigned char);
+	else if (strcmp(type, "int") == 0)
+		size = sizeof(int);
+	else if (strcmp(type, "unsigned int") == 0)
+		size = sizeof(unsigned int);
+	else if (strcmp(type, "long") == 0)
+		size = sizeof(long);
+	else if (strcmp(type, "unsigned long") == 0)
+		size = sizeof(unsigned long);
+	else if (strcmp(type, "bool") == 0)
+		size = sizeof(bool);
+	else if (strcmp(type, "pid_t") == 0)
+		size = sizeof(pid_t);
+	else if (strcmp(type, "gfp_t") == 0)
+		size = sizeof(gfp_t);
+	else if (synth_field_is_string(type))
+		size = synth_field_string_size(type);
+
+	return size;
+}
+
+static const char *synth_field_fmt(char *type)
+{
+	const char *fmt = "%llu";
+
+	if (strcmp(type, "s64") == 0)
+		fmt = "%lld";
+	else if (strcmp(type, "u64") == 0)
+		fmt = "%llu";
+	else if (strcmp(type, "s32") == 0)
+		fmt = "%d";
+	else if (strcmp(type, "u32") == 0)
+		fmt = "%u";
+	else if (strcmp(type, "s16") == 0)
+		fmt = "%d";
+	else if (strcmp(type, "u16") == 0)
+		fmt = "%u";
+	else if (strcmp(type, "s8") == 0)
+		fmt = "%d";
+	else if (strcmp(type, "u8") == 0)
+		fmt = "%u";
+	else if (strcmp(type, "char") == 0)
+		fmt = "%d";
+	else if (strcmp(type, "unsigned char") == 0)
+		fmt = "%u";
+	else if (strcmp(type, "int") == 0)
+		fmt = "%d";
+	else if (strcmp(type, "unsigned int") == 0)
+		fmt = "%u";
+	else if (strcmp(type, "long") == 0)
+		fmt = "%ld";
+	else if (strcmp(type, "unsigned long") == 0)
+		fmt = "%lu";
+	else if (strcmp(type, "bool") == 0)
+		fmt = "%d";
+	else if (strcmp(type, "pid_t") == 0)
+		fmt = "%d";
+	else if (strcmp(type, "gfp_t") == 0)
+		fmt = "%x";
+	else if (synth_field_is_string(type))
+		fmt = "%.*s";
+
+	return fmt;
+}
+
+static void print_synth_event_num_val(struct trace_seq *s,
+				      char *print_fmt, char *name,
+				      int size, u64 val, char *space)
+{
+	switch (size) {
+	case 1:
+		trace_seq_printf(s, print_fmt, name, (u8)val, space);
+		break;
+
+	case 2:
+		trace_seq_printf(s, print_fmt, name, (u16)val, space);
+		break;
+
+	case 4:
+		trace_seq_printf(s, print_fmt, name, (u32)val, space);
+		break;
+
+	default:
+		trace_seq_printf(s, print_fmt, name, val, space);
+		break;
+	}
+}
+
+static enum print_line_t print_synth_event(struct trace_iterator *iter,
+					   int flags,
+					   struct trace_event *event)
+{
+	struct trace_array *tr = iter->tr;
+	struct trace_seq *s = &iter->seq;
+	struct synth_trace_event *entry;
+	struct synth_event *se;
+	unsigned int i, n_u64;
+	char print_fmt[32];
+	const char *fmt;
+
+	entry = (struct synth_trace_event *)iter->ent;
+	se = container_of(event, struct synth_event, call.event);
+
+	trace_seq_printf(s, "%s: ", se->name);
+
+	for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
+		if (trace_seq_has_overflowed(s))
+			goto end;
+
+		fmt = synth_field_fmt(se->fields[i]->type);
+
+		/* parameter types */
+		if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
+			trace_seq_printf(s, "%s ", fmt);
+
+		snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
+
+		/* parameter values */
+		if (se->fields[i]->is_string) {
+			if (se->fields[i]->is_dynamic) {
+				u32 offset, data_offset;
+				char *str_field;
+
+				offset = (u32)entry->fields[n_u64];
+				data_offset = offset & 0xffff;
+
+				str_field = (char *)entry + data_offset;
+
+				trace_seq_printf(s, print_fmt, se->fields[i]->name,
+						 STR_VAR_LEN_MAX,
+						 str_field,
+						 i == se->n_fields - 1 ? "" : " ");
+				n_u64++;
+			} else {
+				trace_seq_printf(s, print_fmt, se->fields[i]->name,
+						 STR_VAR_LEN_MAX,
+						 (char *)&entry->fields[n_u64],
+						 i == se->n_fields - 1 ? "" : " ");
+				n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
+			}
+		} else {
+			struct trace_print_flags __flags[] = {
+			    __def_gfpflag_names, {-1, NULL} };
+			char *space = (i == se->n_fields - 1 ? "" : " ");
+
+			print_synth_event_num_val(s, print_fmt,
+						  se->fields[i]->name,
+						  se->fields[i]->size,
+						  entry->fields[n_u64],
+						  space);
+
+			if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
+				trace_seq_puts(s, " (");
+				trace_print_flags_seq(s, "|",
+						      entry->fields[n_u64],
+						      __flags);
+				trace_seq_putc(s, ')');
+			}
+			n_u64++;
+		}
+	}
+end:
+	trace_seq_putc(s, '\n');
+
+	return trace_handle_return(s);
+}
+
+static struct trace_event_functions synth_event_funcs = {
+	.trace		= print_synth_event
+};
+
+static unsigned int trace_string(struct synth_trace_event *entry,
+				 struct synth_event *event,
+				 char *str_val,
+				 bool is_dynamic,
+				 unsigned int data_size,
+				 unsigned int *n_u64)
+{
+	unsigned int len = 0;
+	char *str_field;
+
+	if (is_dynamic) {
+		u32 data_offset;
+
+		data_offset = offsetof(typeof(*entry), fields);
+		data_offset += event->n_u64 * sizeof(u64);
+		data_offset += data_size;
+
+		str_field = (char *)entry + data_offset;
+
+		len = strlen(str_val) + 1;
+		strscpy(str_field, str_val, len);
+
+		data_offset |= len << 16;
+		*(u32 *)&entry->fields[*n_u64] = data_offset;
+
+		(*n_u64)++;
+	} else {
+		str_field = (char *)&entry->fields[*n_u64];
+
+		strscpy(str_field, str_val, STR_VAR_LEN_MAX);
+		(*n_u64) += STR_VAR_LEN_MAX / sizeof(u64);
+	}
+
+	return len;
+}
+
+static notrace void trace_event_raw_event_synth(void *__data,
+						u64 *var_ref_vals,
+						unsigned int *var_ref_idx)
+{
+	unsigned int i, n_u64, val_idx, len, data_size = 0;
+	struct trace_event_file *trace_file = __data;
+	struct synth_trace_event *entry;
+	struct trace_event_buffer fbuffer;
+	struct trace_buffer *buffer;
+	struct synth_event *event;
+	int fields_size = 0;
+
+	event = trace_file->event_call->data;
+
+	if (trace_trigger_soft_disabled(trace_file))
+		return;
+
+	fields_size = event->n_u64 * sizeof(u64);
+
+	for (i = 0; i < event->n_dynamic_fields; i++) {
+		unsigned int field_pos = event->dynamic_fields[i]->field_pos;
+		char *str_val;
+
+		val_idx = var_ref_idx[field_pos];
+		str_val = (char *)(long)var_ref_vals[val_idx];
+
+		len = strlen(str_val) + 1;
+
+		fields_size += len;
+	}
+
+	/*
+	 * Avoid ring buffer recursion detection, as this event
+	 * is being performed within another event.
+	 */
+	buffer = trace_file->tr->array_buffer.buffer;
+	ring_buffer_nest_start(buffer);
+
+	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
+					   sizeof(*entry) + fields_size);
+	if (!entry)
+		goto out;
+
+	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+		val_idx = var_ref_idx[i];
+		if (event->fields[i]->is_string) {
+			char *str_val = (char *)(long)var_ref_vals[val_idx];
+
+			len = trace_string(entry, event, str_val,
+					   event->fields[i]->is_dynamic,
+					   data_size, &n_u64);
+			data_size += len; /* only dynamic string increments */
+		} else {
+			struct synth_field *field = event->fields[i];
+			u64 val = var_ref_vals[val_idx];
+
+			switch (field->size) {
+			case 1:
+				*(u8 *)&entry->fields[n_u64] = (u8)val;
+				break;
+
+			case 2:
+				*(u16 *)&entry->fields[n_u64] = (u16)val;
+				break;
+
+			case 4:
+				*(u32 *)&entry->fields[n_u64] = (u32)val;
+				break;
+
+			default:
+				entry->fields[n_u64] = val;
+				break;
+			}
+			n_u64++;
+		}
+	}
+
+	trace_event_buffer_commit(&fbuffer);
+out:
+	ring_buffer_nest_end(buffer);
+}
+
+static void free_synth_event_print_fmt(struct trace_event_call *call)
+{
+	if (call) {
+		kfree(call->print_fmt);
+		call->print_fmt = NULL;
+	}
+}
+
+static int __set_synth_event_print_fmt(struct synth_event *event,
+				       char *buf, int len)
+{
+	const char *fmt;
+	int pos = 0;
+	int i;
+
+	/* When len=0, we just calculate the needed length */
+#define LEN_OR_ZERO (len ? len - pos : 0)
+
+	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+	for (i = 0; i < event->n_fields; i++) {
+		fmt = synth_field_fmt(event->fields[i]->type);
+		pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
+				event->fields[i]->name, fmt,
+				i == event->n_fields - 1 ? "" : ", ");
+	}
+	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+
+	for (i = 0; i < event->n_fields; i++) {
+		if (event->fields[i]->is_string &&
+		    event->fields[i]->is_dynamic)
+			pos += snprintf(buf + pos, LEN_OR_ZERO,
+				", __get_str(%s)", event->fields[i]->name);
+		else
+			pos += snprintf(buf + pos, LEN_OR_ZERO,
+					", REC->%s", event->fields[i]->name);
+	}
+
+#undef LEN_OR_ZERO
+
+	/* return the length of print_fmt */
+	return pos;
+}
+
+static int set_synth_event_print_fmt(struct trace_event_call *call)
+{
+	struct synth_event *event = call->data;
+	char *print_fmt;
+	int len;
+
+	/* First: called with 0 length to calculate the needed length */
+	len = __set_synth_event_print_fmt(event, NULL, 0);
+
+	print_fmt = kmalloc(len + 1, GFP_KERNEL);
+	if (!print_fmt)
+		return -ENOMEM;
+
+	/* Second: actually write the @print_fmt */
+	__set_synth_event_print_fmt(event, print_fmt, len + 1);
+	call->print_fmt = print_fmt;
+
+	return 0;
+}
+
+static void free_synth_field(struct synth_field *field)
+{
+	kfree(field->type);
+	kfree(field->name);
+	kfree(field);
+}
+
+static struct synth_field *parse_synth_field(int argc, const char **argv,
+					     int *consumed)
+{
+	struct synth_field *field;
+	const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
+	int len, ret = -ENOMEM;
+	struct seq_buf s;
+	ssize_t size;
+
+	if (field_type[0] == ';')
+		field_type++;
+
+	if (!strcmp(field_type, "unsigned")) {
+		if (argc < 3) {
+			synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type));
+			return ERR_PTR(-EINVAL);
+		}
+		prefix = "unsigned ";
+		field_type = argv[1];
+		field_name = argv[2];
+		*consumed = 3;
+	} else {
+		field_name = argv[1];
+		*consumed = 2;
+	}
+
+	field = kzalloc(sizeof(*field), GFP_KERNEL);
+	if (!field)
+		return ERR_PTR(-ENOMEM);
+
+	len = strlen(field_name);
+	array = strchr(field_name, '[');
+	if (array)
+		len -= strlen(array);
+	else if (field_name[len - 1] == ';')
+		len--;
+
+	field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
+	if (!field->name)
+		goto free;
+
+	if (!is_good_name(field->name)) {
+		synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name));
+		ret = -EINVAL;
+		goto free;
+	}
+
+	if (field_type[0] == ';')
+		field_type++;
+	len = strlen(field_type) + 1;
+
+	if (array)
+		len += strlen(array);
+
+	if (prefix)
+		len += strlen(prefix);
+
+	field->type = kzalloc(len, GFP_KERNEL);
+	if (!field->type)
+		goto free;
+
+	seq_buf_init(&s, field->type, len);
+	if (prefix)
+		seq_buf_puts(&s, prefix);
+	seq_buf_puts(&s, field_type);
+	if (array) {
+		seq_buf_puts(&s, array);
+		if (s.buffer[s.len - 1] == ';')
+			s.len--;
+	}
+	if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
+		goto free;
+
+	s.buffer[s.len] = '\0';
+
+	size = synth_field_size(field->type);
+	if (size < 0) {
+		synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
+		ret = -EINVAL;
+		goto free;
+	} else if (size == 0) {
+		if (synth_field_is_string(field->type)) {
+			char *type;
+
+			len = sizeof("__data_loc ") + strlen(field->type) + 1;
+			type = kzalloc(len, GFP_KERNEL);
+			if (!type)
+				goto free;
+
+			seq_buf_init(&s, type, len);
+			seq_buf_puts(&s, "__data_loc ");
+			seq_buf_puts(&s, field->type);
+
+			if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
+				goto free;
+			s.buffer[s.len] = '\0';
+
+			kfree(field->type);
+			field->type = type;
+
+			field->is_dynamic = true;
+			size = sizeof(u64);
+		} else {
+			synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
+			ret = -EINVAL;
+			goto free;
+		}
+	}
+	field->size = size;
+
+	if (synth_field_is_string(field->type))
+		field->is_string = true;
+
+	field->is_signed = synth_field_signed(field->type);
+ out:
+	return field;
+ free:
+	free_synth_field(field);
+	field = ERR_PTR(ret);
+	goto out;
+}
+
+static void free_synth_tracepoint(struct tracepoint *tp)
+{
+	if (!tp)
+		return;
+
+	kfree(tp->name);
+	kfree(tp);
+}
+
+static struct tracepoint *alloc_synth_tracepoint(char *name)
+{
+	struct tracepoint *tp;
+
+	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
+	if (!tp)
+		return ERR_PTR(-ENOMEM);
+
+	tp->name = kstrdup(name, GFP_KERNEL);
+	if (!tp->name) {
+		kfree(tp);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return tp;
+}
+
+struct synth_event *find_synth_event(const char *name)
+{
+	struct dyn_event *pos;
+	struct synth_event *event;
+
+	for_each_dyn_event(pos) {
+		if (!is_synth_event(pos))
+			continue;
+		event = to_synth_event(pos);
+		if (strcmp(event->name, name) == 0)
+			return event;
+	}
+
+	return NULL;
+}
+
+static struct trace_event_fields synth_event_fields_array[] = {
+	{ .type = TRACE_FUNCTION_TYPE,
+	  .define_fields = synth_event_define_fields },
+	{}
+};
+
+static int register_synth_event(struct synth_event *event)
+{
+	struct trace_event_call *call = &event->call;
+	int ret = 0;
+
+	event->call.class = &event->class;
+	event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
+	if (!event->class.system) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	event->tp = alloc_synth_tracepoint(event->name);
+	if (IS_ERR(event->tp)) {
+		ret = PTR_ERR(event->tp);
+		event->tp = NULL;
+		goto out;
+	}
+
+	INIT_LIST_HEAD(&call->class->fields);
+	call->event.funcs = &synth_event_funcs;
+	call->class->fields_array = synth_event_fields_array;
+
+	ret = register_trace_event(&call->event);
+	if (!ret) {
+		ret = -ENODEV;
+		goto out;
+	}
+	call->flags = TRACE_EVENT_FL_TRACEPOINT;
+	call->class->reg = trace_event_reg;
+	call->class->probe = trace_event_raw_event_synth;
+	call->data = event;
+	call->tp = event->tp;
+
+	ret = trace_add_event_call(call);
+	if (ret) {
+		pr_warn("Failed to register synthetic event: %s\n",
+			trace_event_name(call));
+		goto err;
+	}
+
+	ret = set_synth_event_print_fmt(call);
+	if (ret < 0) {
+		trace_remove_event_call(call);
+		goto err;
+	}
+ out:
+	return ret;
+ err:
+	unregister_trace_event(&call->event);
+	goto out;
+}
+
+static int unregister_synth_event(struct synth_event *event)
+{
+	struct trace_event_call *call = &event->call;
+	int ret;
+
+	ret = trace_remove_event_call(call);
+
+	return ret;
+}
+
+static void free_synth_event(struct synth_event *event)
+{
+	unsigned int i;
+
+	if (!event)
+		return;
+
+	for (i = 0; i < event->n_fields; i++)
+		free_synth_field(event->fields[i]);
+
+	kfree(event->fields);
+	kfree(event->dynamic_fields);
+	kfree(event->name);
+	kfree(event->class.system);
+	free_synth_tracepoint(event->tp);
+	free_synth_event_print_fmt(&event->call);
+	kfree(event);
+}
+
+static struct synth_event *alloc_synth_event(const char *name, int n_fields,
+					     struct synth_field **fields)
+{
+	unsigned int i, j, n_dynamic_fields = 0;
+	struct synth_event *event;
+
+	event = kzalloc(sizeof(*event), GFP_KERNEL);
+	if (!event) {
+		event = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	event->name = kstrdup(name, GFP_KERNEL);
+	if (!event->name) {
+		kfree(event);
+		event = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
+	if (!event->fields) {
+		free_synth_event(event);
+		event = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	for (i = 0; i < n_fields; i++)
+		if (fields[i]->is_dynamic)
+			n_dynamic_fields++;
+
+	if (n_dynamic_fields) {
+		event->dynamic_fields = kcalloc(n_dynamic_fields,
+						sizeof(*event->dynamic_fields),
+						GFP_KERNEL);
+		if (!event->dynamic_fields) {
+			free_synth_event(event);
+			event = ERR_PTR(-ENOMEM);
+			goto out;
+		}
+	}
+
+	dyn_event_init(&event->devent, &synth_event_ops);
+
+	for (i = 0, j = 0; i < n_fields; i++) {
+		event->fields[i] = fields[i];
+
+		if (fields[i]->is_dynamic) {
+			event->dynamic_fields[j] = fields[i];
+			event->dynamic_fields[j]->field_pos = i;
+			event->dynamic_fields[j++] = fields[i];
+			event->n_dynamic_fields++;
+		}
+	}
+	event->n_fields = n_fields;
+ out:
+	return event;
+}
+
+static int synth_event_check_arg_fn(void *data)
+{
+	struct dynevent_arg_pair *arg_pair = data;
+	int size;
+
+	size = synth_field_size((char *)arg_pair->lhs);
+	if (size == 0) {
+		if (strstr((char *)arg_pair->lhs, "["))
+			return 0;
+	}
+
+	return size ? 0 : -EINVAL;
+}
+
+/**
+ * synth_event_add_field - Add a new field to a synthetic event cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @type: The type of the new field to add
+ * @name: The name of the new field to add
+ *
+ * Add a new field to a synthetic event cmd object.  Field ordering is in
+ * the same order the fields are added.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_add_field(struct dynevent_cmd *cmd, const char *type,
+			  const char *name)
+{
+	struct dynevent_arg_pair arg_pair;
+	int ret;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	if (!type || !name)
+		return -EINVAL;
+
+	dynevent_arg_pair_init(&arg_pair, 0, ';');
+
+	arg_pair.lhs = type;
+	arg_pair.rhs = name;
+
+	ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn);
+	if (ret)
+		return ret;
+
+	if (++cmd->n_fields > SYNTH_FIELDS_MAX)
+		ret = -EINVAL;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_add_field);
+
+/**
+ * synth_event_add_field_str - Add a new field to a synthetic event cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @type_name: The type and name of the new field to add, as a single string
+ *
+ * Add a new field to a synthetic event cmd object, as a single
+ * string.  The @type_name string is expected to be of the form 'type
+ * name', which will be appended by ';'.  No sanity checking is done -
+ * what's passed in is assumed to already be well-formed.  Field
+ * ordering is in the same order the fields are added.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name)
+{
+	struct dynevent_arg arg;
+	int ret;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	if (!type_name)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, ';');
+
+	arg.str = type_name;
+
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	if (++cmd->n_fields > SYNTH_FIELDS_MAX)
+		ret = -EINVAL;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_add_field_str);
+
+/**
+ * synth_event_add_fields - Add multiple fields to a synthetic event cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @fields: An array of type/name field descriptions
+ * @n_fields: The number of field descriptions contained in the fields array
+ *
+ * Add a new set of fields to a synthetic event cmd object.  The event
+ * fields that will be defined for the event should be passed in as an
+ * array of struct synth_field_desc, and the number of elements in the
+ * array passed in as n_fields.  Field ordering will retain the
+ * ordering given in the fields array.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_add_fields(struct dynevent_cmd *cmd,
+			   struct synth_field_desc *fields,
+			   unsigned int n_fields)
+{
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < n_fields; i++) {
+		if (fields[i].type == NULL || fields[i].name == NULL) {
+			ret = -EINVAL;
+			break;
+		}
+
+		ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_add_fields);
+
+/**
+ * __synth_event_gen_cmd_start - Start a synthetic event command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @name: The name of the synthetic event
+ * @mod: The module creating the event, NULL if not created from a module
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the synth_event_gen_cmd_start() wrapper, which
+ * automatically adds a NULL to the end of the arg list.  If this
+ * function is used directly, make sure the last arg in the variable
+ * arg list is NULL.
+ *
+ * Generate a synthetic event command to be executed by
+ * synth_event_gen_cmd_end().  This function can be used to generate
+ * the complete command or only the first part of it; in the latter
+ * case, synth_event_add_field(), synth_event_add_field_str(), or
+ * synth_event_add_fields() can be used to add more fields following
+ * this.
+ *
+ * There should be an even number variable args, each pair consisting
+ * of a type followed by a field name.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name,
+				struct module *mod, ...)
+{
+	struct dynevent_arg arg;
+	va_list args;
+	int ret;
+
+	cmd->event_name = name;
+	cmd->private_data = mod;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, 0);
+	arg.str = name;
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	va_start(args, mod);
+	for (;;) {
+		const char *type, *name;
+
+		type = va_arg(args, const char *);
+		if (!type)
+			break;
+		name = va_arg(args, const char *);
+		if (!name)
+			break;
+
+		if (++cmd->n_fields > SYNTH_FIELDS_MAX) {
+			ret = -EINVAL;
+			break;
+		}
+
+		ret = synth_event_add_field(cmd, type, name);
+		if (ret)
+			break;
+	}
+	va_end(args);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start);
+
+/**
+ * synth_event_gen_cmd_array_start - Start synthetic event command from an array
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @name: The name of the synthetic event
+ * @fields: An array of type/name field descriptions
+ * @n_fields: The number of field descriptions contained in the fields array
+ *
+ * Generate a synthetic event command to be executed by
+ * synth_event_gen_cmd_end().  This function can be used to generate
+ * the complete command or only the first part of it; in the latter
+ * case, synth_event_add_field(), synth_event_add_field_str(), or
+ * synth_event_add_fields() can be used to add more fields following
+ * this.
+ *
+ * The event fields that will be defined for the event should be
+ * passed in as an array of struct synth_field_desc, and the number of
+ * elements in the array passed in as n_fields.  Field ordering will
+ * retain the ordering given in the fields array.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name,
+				    struct module *mod,
+				    struct synth_field_desc *fields,
+				    unsigned int n_fields)
+{
+	struct dynevent_arg arg;
+	unsigned int i;
+	int ret = 0;
+
+	cmd->event_name = name;
+	cmd->private_data = mod;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	if (n_fields > SYNTH_FIELDS_MAX)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, 0);
+	arg.str = name;
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < n_fields; i++) {
+		if (fields[i].type == NULL || fields[i].name == NULL)
+			return -EINVAL;
+
+		ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start);
+
+static int save_cmdstr(int argc, const char *name, const char **argv)
+{
+	struct seq_buf s;
+	char *buf;
+	int i;
+
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	seq_buf_init(&s, buf, MAX_DYNEVENT_CMD_LEN);
+
+	seq_buf_puts(&s, name);
+
+	for (i = 0; i < argc; i++) {
+		seq_buf_putc(&s, ' ');
+		seq_buf_puts(&s, argv[i]);
+	}
+
+	if (!seq_buf_buffer_left(&s)) {
+		synth_err(SYNTH_ERR_CMD_TOO_LONG, 0);
+		kfree(buf);
+		return -EINVAL;
+	}
+	buf[s.len] = 0;
+	last_cmd_set(buf);
+
+	kfree(buf);
+	return 0;
+}
+
+static int __create_synth_event(int argc, const char *name, const char **argv)
+{
+	struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
+	struct synth_event *event = NULL;
+	int i, consumed = 0, n_fields = 0, ret = 0;
+
+	ret = save_cmdstr(argc, name, argv);
+	if (ret)
+		return ret;
+
+	/*
+	 * Argument syntax:
+	 *  - Add synthetic event: <event_name> field[;field] ...
+	 *  - Remove synthetic event: !<event_name> field[;field] ...
+	 *      where 'field' = type field_name
+	 */
+
+	if (name[0] == '\0' || argc < 1) {
+		synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0);
+		return -EINVAL;
+	}
+
+	mutex_lock(&event_mutex);
+
+	if (!is_good_name(name)) {
+		synth_err(SYNTH_ERR_BAD_NAME, errpos(name));
+		ret = -EINVAL;
+		goto out;
+	}
+
+	event = find_synth_event(name);
+	if (event) {
+		synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name));
+		ret = -EEXIST;
+		goto out;
+	}
+
+	for (i = 0; i < argc - 1; i++) {
+		if (strcmp(argv[i], ";") == 0)
+			continue;
+		if (n_fields == SYNTH_FIELDS_MAX) {
+			synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		field = parse_synth_field(argc - i, &argv[i], &consumed);
+		if (IS_ERR(field)) {
+			ret = PTR_ERR(field);
+			goto err;
+		}
+		fields[n_fields++] = field;
+		i += consumed - 1;
+	}
+
+	if (i < argc && strcmp(argv[i], ";") != 0) {
+		synth_err(SYNTH_ERR_INVALID_FIELD, errpos(argv[i]));
+		ret = -EINVAL;
+		goto err;
+	}
+
+	event = alloc_synth_event(name, n_fields, fields);
+	if (IS_ERR(event)) {
+		ret = PTR_ERR(event);
+		event = NULL;
+		goto err;
+	}
+	ret = register_synth_event(event);
+	if (!ret)
+		dyn_event_add(&event->devent);
+	else
+		free_synth_event(event);
+ out:
+	mutex_unlock(&event_mutex);
+
+	return ret;
+ err:
+	for (i = 0; i < n_fields; i++)
+		free_synth_field(fields[i]);
+
+	goto out;
+}
+
+/**
+ * synth_event_create - Create a new synthetic event
+ * @name: The name of the new sythetic event
+ * @fields: An array of type/name field descriptions
+ * @n_fields: The number of field descriptions contained in the fields array
+ * @mod: The module creating the event, NULL if not created from a module
+ *
+ * Create a new synthetic event with the given name under the
+ * trace/events/synthetic/ directory.  The event fields that will be
+ * defined for the event should be passed in as an array of struct
+ * synth_field_desc, and the number elements in the array passed in as
+ * n_fields. Field ordering will retain the ordering given in the
+ * fields array.
+ *
+ * If the new synthetic event is being created from a module, the mod
+ * param must be non-NULL.  This will ensure that the trace buffer
+ * won't contain unreadable events.
+ *
+ * The new synth event should be deleted using synth_event_delete()
+ * function.  The new synthetic event can be generated from modules or
+ * other kernel code using trace_synth_event() and related functions.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_create(const char *name, struct synth_field_desc *fields,
+		       unsigned int n_fields, struct module *mod)
+{
+	struct dynevent_cmd cmd;
+	char *buf;
+	int ret;
+
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	ret = synth_event_gen_cmd_array_start(&cmd, name, mod,
+					      fields, n_fields);
+	if (ret)
+		goto out;
+
+	ret = synth_event_gen_cmd_end(&cmd);
+ out:
+	kfree(buf);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_create);
+
+static int destroy_synth_event(struct synth_event *se)
+{
+	int ret;
+
+	if (se->ref)
+		ret = -EBUSY;
+	else {
+		ret = unregister_synth_event(se);
+		if (!ret) {
+			dyn_event_remove(&se->devent);
+			free_synth_event(se);
+		}
+	}
+
+	return ret;
+}
+
+/**
+ * synth_event_delete - Delete a synthetic event
+ * @event_name: The name of the new sythetic event
+ *
+ * Delete a synthetic event that was created with synth_event_create().
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_delete(const char *event_name)
+{
+	struct synth_event *se = NULL;
+	struct module *mod = NULL;
+	int ret = -ENOENT;
+
+	mutex_lock(&event_mutex);
+	se = find_synth_event(event_name);
+	if (se) {
+		mod = se->mod;
+		ret = destroy_synth_event(se);
+	}
+	mutex_unlock(&event_mutex);
+
+	if (mod) {
+		mutex_lock(&trace_types_lock);
+		/*
+		 * It is safest to reset the ring buffer if the module
+		 * being unloaded registered any events that were
+		 * used. The only worry is if a new module gets
+		 * loaded, and takes on the same id as the events of
+		 * this module. When printing out the buffer, traced
+		 * events left over from this module may be passed to
+		 * the new module events and unexpected results may
+		 * occur.
+		 */
+		tracing_reset_all_online_cpus();
+		mutex_unlock(&trace_types_lock);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_delete);
+
+static int create_or_delete_synth_event(int argc, char **argv)
+{
+	const char *name = argv[0];
+	int ret;
+
+	/* trace_run_command() ensures argc != 0 */
+	if (name[0] == '!') {
+		ret = synth_event_delete(name + 1);
+		return ret;
+	}
+
+	ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
+	return ret == -ECANCELED ? -EINVAL : ret;
+}
+
+static int synth_event_run_command(struct dynevent_cmd *cmd)
+{
+	struct synth_event *se;
+	int ret;
+
+	ret = trace_run_command(cmd->seq.buffer, create_or_delete_synth_event);
+	if (ret)
+		return ret;
+
+	se = find_synth_event(cmd->event_name);
+	if (WARN_ON(!se))
+		return -ENOENT;
+
+	se->mod = cmd->private_data;
+
+	return ret;
+}
+
+/**
+ * synth_event_cmd_init - Initialize a synthetic event command object
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @buf: A pointer to the buffer used to build the command
+ * @maxlen: The length of the buffer passed in @buf
+ *
+ * Initialize a synthetic event command object.  Use this before
+ * calling any of the other dyenvent_cmd functions.
+ */
+void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
+{
+	dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH,
+			  synth_event_run_command);
+}
+EXPORT_SYMBOL_GPL(synth_event_cmd_init);
+
+static inline int
+__synth_event_trace_init(struct trace_event_file *file,
+			 struct synth_event_trace_state *trace_state)
+{
+	int ret = 0;
+
+	memset(trace_state, '\0', sizeof(*trace_state));
+
+	/*
+	 * Normal event tracing doesn't get called at all unless the
+	 * ENABLED bit is set (which attaches the probe thus allowing
+	 * this code to be called, etc).  Because this is called
+	 * directly by the user, we don't have that but we still need
+	 * to honor not logging when disabled.  For the iterated
+	 * trace case, we save the enabed state upon start and just
+	 * ignore the following data calls.
+	 */
+	if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
+	    trace_trigger_soft_disabled(file)) {
+		trace_state->disabled = true;
+		ret = -ENOENT;
+		goto out;
+	}
+
+	trace_state->event = file->event_call->data;
+out:
+	return ret;
+}
+
+static inline int
+__synth_event_trace_start(struct trace_event_file *file,
+			  struct synth_event_trace_state *trace_state,
+			  int dynamic_fields_size)
+{
+	int entry_size, fields_size = 0;
+	int ret = 0;
+
+	fields_size = trace_state->event->n_u64 * sizeof(u64);
+	fields_size += dynamic_fields_size;
+
+	/*
+	 * Avoid ring buffer recursion detection, as this event
+	 * is being performed within another event.
+	 */
+	trace_state->buffer = file->tr->array_buffer.buffer;
+	ring_buffer_nest_start(trace_state->buffer);
+
+	entry_size = sizeof(*trace_state->entry) + fields_size;
+	trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer,
+							file,
+							entry_size);
+	if (!trace_state->entry) {
+		ring_buffer_nest_end(trace_state->buffer);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static inline void
+__synth_event_trace_end(struct synth_event_trace_state *trace_state)
+{
+	trace_event_buffer_commit(&trace_state->fbuffer);
+
+	ring_buffer_nest_end(trace_state->buffer);
+}
+
+/**
+ * synth_event_trace - Trace a synthetic event
+ * @file: The trace_event_file representing the synthetic event
+ * @n_vals: The number of values in vals
+ * @args: Variable number of args containing the event values
+ *
+ * Trace a synthetic event using the values passed in the variable
+ * argument list.
+ *
+ * The argument list should be a list 'n_vals' u64 values.  The number
+ * of vals must match the number of field in the synthetic event, and
+ * must be in the same order as the synthetic event fields.
+ *
+ * All vals should be cast to u64, and string vals are just pointers
+ * to strings, cast to u64.  Strings will be copied into space
+ * reserved in the event for the string, using these pointers.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
+{
+	unsigned int i, n_u64, len, data_size = 0;
+	struct synth_event_trace_state state;
+	va_list args;
+	int ret;
+
+	ret = __synth_event_trace_init(file, &state);
+	if (ret) {
+		if (ret == -ENOENT)
+			ret = 0; /* just disabled, not really an error */
+		return ret;
+	}
+
+	if (state.event->n_dynamic_fields) {
+		va_start(args, n_vals);
+
+		for (i = 0; i < state.event->n_fields; i++) {
+			u64 val = va_arg(args, u64);
+
+			if (state.event->fields[i]->is_string &&
+			    state.event->fields[i]->is_dynamic) {
+				char *str_val = (char *)(long)val;
+
+				data_size += strlen(str_val) + 1;
+			}
+		}
+
+		va_end(args);
+	}
+
+	ret = __synth_event_trace_start(file, &state, data_size);
+	if (ret)
+		return ret;
+
+	if (n_vals != state.event->n_fields) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	data_size = 0;
+
+	va_start(args, n_vals);
+	for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
+		u64 val;
+
+		val = va_arg(args, u64);
+
+		if (state.event->fields[i]->is_string) {
+			char *str_val = (char *)(long)val;
+
+			len = trace_string(state.entry, state.event, str_val,
+					   state.event->fields[i]->is_dynamic,
+					   data_size, &n_u64);
+			data_size += len; /* only dynamic string increments */
+		} else {
+			struct synth_field *field = state.event->fields[i];
+
+			switch (field->size) {
+			case 1:
+				*(u8 *)&state.entry->fields[n_u64] = (u8)val;
+				break;
+
+			case 2:
+				*(u16 *)&state.entry->fields[n_u64] = (u16)val;
+				break;
+
+			case 4:
+				*(u32 *)&state.entry->fields[n_u64] = (u32)val;
+				break;
+
+			default:
+				state.entry->fields[n_u64] = val;
+				break;
+			}
+			n_u64++;
+		}
+	}
+	va_end(args);
+out:
+	__synth_event_trace_end(&state);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace);
+
+/**
+ * synth_event_trace_array - Trace a synthetic event from an array
+ * @file: The trace_event_file representing the synthetic event
+ * @vals: Array of values
+ * @n_vals: The number of values in vals
+ *
+ * Trace a synthetic event using the values passed in as 'vals'.
+ *
+ * The 'vals' array is just an array of 'n_vals' u64.  The number of
+ * vals must match the number of field in the synthetic event, and
+ * must be in the same order as the synthetic event fields.
+ *
+ * All vals should be cast to u64, and string vals are just pointers
+ * to strings, cast to u64.  Strings will be copied into space
+ * reserved in the event for the string, using these pointers.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
+			    unsigned int n_vals)
+{
+	unsigned int i, n_u64, field_pos, len, data_size = 0;
+	struct synth_event_trace_state state;
+	char *str_val;
+	int ret;
+
+	ret = __synth_event_trace_init(file, &state);
+	if (ret) {
+		if (ret == -ENOENT)
+			ret = 0; /* just disabled, not really an error */
+		return ret;
+	}
+
+	if (state.event->n_dynamic_fields) {
+		for (i = 0; i < state.event->n_dynamic_fields; i++) {
+			field_pos = state.event->dynamic_fields[i]->field_pos;
+			str_val = (char *)(long)vals[field_pos];
+			len = strlen(str_val) + 1;
+			data_size += len;
+		}
+	}
+
+	ret = __synth_event_trace_start(file, &state, data_size);
+	if (ret)
+		return ret;
+
+	if (n_vals != state.event->n_fields) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	data_size = 0;
+
+	for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
+		if (state.event->fields[i]->is_string) {
+			char *str_val = (char *)(long)vals[i];
+
+			len = trace_string(state.entry, state.event, str_val,
+					   state.event->fields[i]->is_dynamic,
+					   data_size, &n_u64);
+			data_size += len; /* only dynamic string increments */
+		} else {
+			struct synth_field *field = state.event->fields[i];
+			u64 val = vals[i];
+
+			switch (field->size) {
+			case 1:
+				*(u8 *)&state.entry->fields[n_u64] = (u8)val;
+				break;
+
+			case 2:
+				*(u16 *)&state.entry->fields[n_u64] = (u16)val;
+				break;
+
+			case 4:
+				*(u32 *)&state.entry->fields[n_u64] = (u32)val;
+				break;
+
+			default:
+				state.entry->fields[n_u64] = val;
+				break;
+			}
+			n_u64++;
+		}
+	}
+out:
+	__synth_event_trace_end(&state);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace_array);
+
+/**
+ * synth_event_trace_start - Start piecewise synthetic event trace
+ * @file: The trace_event_file representing the synthetic event
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * Start the trace of a synthetic event field-by-field rather than all
+ * at once.
+ *
+ * This function 'opens' an event trace, which means space is reserved
+ * for the event in the trace buffer, after which the event's
+ * individual field values can be set through either
+ * synth_event_add_next_val() or synth_event_add_val().
+ *
+ * A pointer to a trace_state object is passed in, which will keep
+ * track of the current event trace state until the event trace is
+ * closed (and the event finally traced) using
+ * synth_event_trace_end().
+ *
+ * Note that synth_event_trace_end() must be called after all values
+ * have been added for each event trace, regardless of whether adding
+ * all field values succeeded or not.
+ *
+ * Note also that for a given event trace, all fields must be added
+ * using either synth_event_add_next_val() or synth_event_add_val()
+ * but not both together or interleaved.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace_start(struct trace_event_file *file,
+			    struct synth_event_trace_state *trace_state)
+{
+	int ret;
+
+	if (!trace_state)
+		return -EINVAL;
+
+	ret = __synth_event_trace_init(file, trace_state);
+	if (ret) {
+		if (ret == -ENOENT)
+			ret = 0; /* just disabled, not really an error */
+		return ret;
+	}
+
+	if (trace_state->event->n_dynamic_fields)
+		return -ENOTSUPP;
+
+	ret = __synth_event_trace_start(file, trace_state, 0);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace_start);
+
+static int __synth_event_add_val(const char *field_name, u64 val,
+				 struct synth_event_trace_state *trace_state)
+{
+	struct synth_field *field = NULL;
+	struct synth_trace_event *entry;
+	struct synth_event *event;
+	int i, ret = 0;
+
+	if (!trace_state) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* can't mix add_next_synth_val() with add_synth_val() */
+	if (field_name) {
+		if (trace_state->add_next) {
+			ret = -EINVAL;
+			goto out;
+		}
+		trace_state->add_name = true;
+	} else {
+		if (trace_state->add_name) {
+			ret = -EINVAL;
+			goto out;
+		}
+		trace_state->add_next = true;
+	}
+
+	if (trace_state->disabled)
+		goto out;
+
+	event = trace_state->event;
+	if (trace_state->add_name) {
+		for (i = 0; i < event->n_fields; i++) {
+			field = event->fields[i];
+			if (strcmp(field->name, field_name) == 0)
+				break;
+		}
+		if (!field) {
+			ret = -EINVAL;
+			goto out;
+		}
+	} else {
+		if (trace_state->cur_field >= event->n_fields) {
+			ret = -EINVAL;
+			goto out;
+		}
+		field = event->fields[trace_state->cur_field++];
+	}
+
+	entry = trace_state->entry;
+	if (field->is_string) {
+		char *str_val = (char *)(long)val;
+		char *str_field;
+
+		if (field->is_dynamic) { /* add_val can't do dynamic strings */
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (!str_val) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		str_field = (char *)&entry->fields[field->offset];
+		strscpy(str_field, str_val, STR_VAR_LEN_MAX);
+	} else {
+		switch (field->size) {
+		case 1:
+			*(u8 *)&trace_state->entry->fields[field->offset] = (u8)val;
+			break;
+
+		case 2:
+			*(u16 *)&trace_state->entry->fields[field->offset] = (u16)val;
+			break;
+
+		case 4:
+			*(u32 *)&trace_state->entry->fields[field->offset] = (u32)val;
+			break;
+
+		default:
+			trace_state->entry->fields[field->offset] = val;
+			break;
+		}
+	}
+ out:
+	return ret;
+}
+
+/**
+ * synth_event_add_next_val - Add the next field's value to an open synth trace
+ * @val: The value to set the next field to
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * Set the value of the next field in an event that's been opened by
+ * synth_event_trace_start().
+ *
+ * The val param should be the value cast to u64.  If the value points
+ * to a string, the val param should be a char * cast to u64.
+ *
+ * This function assumes all the fields in an event are to be set one
+ * after another - successive calls to this function are made, one for
+ * each field, in the order of the fields in the event, until all
+ * fields have been set.  If you'd rather set each field individually
+ * without regard to ordering, synth_event_add_val() can be used
+ * instead.
+ *
+ * Note however that synth_event_add_next_val() and
+ * synth_event_add_val() can't be intermixed for a given event trace -
+ * one or the other but not both can be used at the same time.
+ *
+ * Note also that synth_event_trace_end() must be called after all
+ * values have been added for each event trace, regardless of whether
+ * adding all field values succeeded or not.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_add_next_val(u64 val,
+			     struct synth_event_trace_state *trace_state)
+{
+	return __synth_event_add_val(NULL, val, trace_state);
+}
+EXPORT_SYMBOL_GPL(synth_event_add_next_val);
+
+/**
+ * synth_event_add_val - Add a named field's value to an open synth trace
+ * @field_name: The name of the synthetic event field value to set
+ * @val: The value to set the next field to
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * Set the value of the named field in an event that's been opened by
+ * synth_event_trace_start().
+ *
+ * The val param should be the value cast to u64.  If the value points
+ * to a string, the val param should be a char * cast to u64.
+ *
+ * This function looks up the field name, and if found, sets the field
+ * to the specified value.  This lookup makes this function more
+ * expensive than synth_event_add_next_val(), so use that or the
+ * none-piecewise synth_event_trace() instead if efficiency is more
+ * important.
+ *
+ * Note however that synth_event_add_next_val() and
+ * synth_event_add_val() can't be intermixed for a given event trace -
+ * one or the other but not both can be used at the same time.
+ *
+ * Note also that synth_event_trace_end() must be called after all
+ * values have been added for each event trace, regardless of whether
+ * adding all field values succeeded or not.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_add_val(const char *field_name, u64 val,
+			struct synth_event_trace_state *trace_state)
+{
+	return __synth_event_add_val(field_name, val, trace_state);
+}
+EXPORT_SYMBOL_GPL(synth_event_add_val);
+
+/**
+ * synth_event_trace_end - End piecewise synthetic event trace
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * End the trace of a synthetic event opened by
+ * synth_event_trace__start().
+ *
+ * This function 'closes' an event trace, which basically means that
+ * it commits the reserved event and cleans up other loose ends.
+ *
+ * A pointer to a trace_state object is passed in, which will keep
+ * track of the current event trace state opened with
+ * synth_event_trace_start().
+ *
+ * Note that this function must be called after all values have been
+ * added for each event trace, regardless of whether adding all field
+ * values succeeded or not.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace_end(struct synth_event_trace_state *trace_state)
+{
+	if (!trace_state)
+		return -EINVAL;
+
+	__synth_event_trace_end(trace_state);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace_end);
+
+static int create_synth_event(int argc, const char **argv)
+{
+	const char *name = argv[0];
+	int len;
+
+	if (name[0] != 's' || name[1] != ':')
+		return -ECANCELED;
+	name += 2;
+
+	/* This interface accepts group name prefix */
+	if (strchr(name, '/')) {
+		len = str_has_prefix(name, SYNTH_SYSTEM "/");
+		if (len == 0)
+			return -EINVAL;
+		name += len;
+	}
+	return __create_synth_event(argc - 1, name, argv + 1);
+}
+
+static int synth_event_release(struct dyn_event *ev)
+{
+	struct synth_event *event = to_synth_event(ev);
+	int ret;
+
+	if (event->ref)
+		return -EBUSY;
+
+	ret = unregister_synth_event(event);
+	if (ret)
+		return ret;
+
+	dyn_event_remove(ev);
+	free_synth_event(event);
+	return 0;
+}
+
+static int __synth_event_show(struct seq_file *m, struct synth_event *event)
+{
+	struct synth_field *field;
+	unsigned int i;
+	char *type, *t;
+
+	seq_printf(m, "%s\t", event->name);
+
+	for (i = 0; i < event->n_fields; i++) {
+		field = event->fields[i];
+
+		type = field->type;
+		t = strstr(type, "__data_loc");
+		if (t) { /* __data_loc belongs in format but not event desc */
+			t += sizeof("__data_loc");
+			type = t;
+		}
+
+		/* parameter values */
+		seq_printf(m, "%s %s%s", type, field->name,
+			   i == event->n_fields - 1 ? "" : "; ");
+	}
+
+	seq_putc(m, '\n');
+
+	return 0;
+}
+
+static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
+{
+	struct synth_event *event = to_synth_event(ev);
+
+	seq_printf(m, "s:%s/", event->class.system);
+
+	return __synth_event_show(m, event);
+}
+
+static int synth_events_seq_show(struct seq_file *m, void *v)
+{
+	struct dyn_event *ev = v;
+
+	if (!is_synth_event(ev))
+		return 0;
+
+	return __synth_event_show(m, to_synth_event(ev));
+}
+
+static const struct seq_operations synth_events_seq_op = {
+	.start	= dyn_event_seq_start,
+	.next	= dyn_event_seq_next,
+	.stop	= dyn_event_seq_stop,
+	.show	= synth_events_seq_show,
+};
+
+static int synth_events_open(struct inode *inode, struct file *file)
+{
+	int ret;
+
+	ret = security_locked_down(LOCKDOWN_TRACEFS);
+	if (ret)
+		return ret;
+
+	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+		ret = dyn_events_release_all(&synth_event_ops);
+		if (ret < 0)
+			return ret;
+	}
+
+	return seq_open(file, &synth_events_seq_op);
+}
+
+static ssize_t synth_events_write(struct file *file,
+				  const char __user *buffer,
+				  size_t count, loff_t *ppos)
+{
+	return trace_parse_run_command(file, buffer, count, ppos,
+				       create_or_delete_synth_event);
+}
+
+static const struct file_operations synth_events_fops = {
+	.open           = synth_events_open,
+	.write		= synth_events_write,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release        = seq_release,
+};
+
+/*
+ * Register dynevent at core_initcall. This allows kernel to setup kprobe
+ * events in postcore_initcall without tracefs.
+ */
+static __init int trace_events_synth_init_early(void)
+{
+	int err = 0;
+
+	err = dyn_event_register(&synth_event_ops);
+	if (err)
+		pr_warn("Could not register synth_event_ops\n");
+
+	return err;
+}
+core_initcall(trace_events_synth_init_early);
+
+static __init int trace_events_synth_init(void)
+{
+	struct dentry *entry = NULL;
+	int err = 0;
+	err = tracing_init_dentry();
+	if (err)
+		goto err;
+
+	entry = tracefs_create_file("synthetic_events", 0644, NULL,
+				    NULL, &synth_events_fops);
+	if (!entry) {
+		err = -ENODEV;
+		goto err;
+	}
+
+	return err;
+ err:
+	pr_warn("Could not create tracefs 'synthetic_events' entry\n");
+
+	return err;
+}
+
+fs_initcall(trace_events_synth_init);
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index e913d41..d0309de 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -214,7 +214,7 @@
 	return ret;
 }
 
-static int trigger_process_regex(struct trace_event_file *file, char *buff)
+int trigger_process_regex(struct trace_event_file *file, char *buff)
 {
 	char *command, *next;
 	struct event_command *p;
@@ -940,6 +940,16 @@
 traceon_trigger(struct event_trigger_data *data, void *rec,
 		struct ring_buffer_event *event)
 {
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (tracer_tracing_is_on(file->tr))
+			return;
+
+		tracer_tracing_on(file->tr);
+		return;
+	}
+
 	if (tracing_is_on())
 		return;
 
@@ -950,8 +960,15 @@
 traceon_count_trigger(struct event_trigger_data *data, void *rec,
 		      struct ring_buffer_event *event)
 {
-	if (tracing_is_on())
-		return;
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (tracer_tracing_is_on(file->tr))
+			return;
+	} else {
+		if (tracing_is_on())
+			return;
+	}
 
 	if (!data->count)
 		return;
@@ -959,13 +976,26 @@
 	if (data->count != -1)
 		(data->count)--;
 
-	tracing_on();
+	if (file)
+		tracer_tracing_on(file->tr);
+	else
+		tracing_on();
 }
 
 static void
 traceoff_trigger(struct event_trigger_data *data, void *rec,
 		 struct ring_buffer_event *event)
 {
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (!tracer_tracing_is_on(file->tr))
+			return;
+
+		tracer_tracing_off(file->tr);
+		return;
+	}
+
 	if (!tracing_is_on())
 		return;
 
@@ -976,8 +1006,15 @@
 traceoff_count_trigger(struct event_trigger_data *data, void *rec,
 		       struct ring_buffer_event *event)
 {
-	if (!tracing_is_on())
-		return;
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (!tracer_tracing_is_on(file->tr))
+			return;
+	} else {
+		if (!tracing_is_on())
+			return;
+	}
 
 	if (!data->count)
 		return;
@@ -985,7 +1022,10 @@
 	if (data->count != -1)
 		(data->count)--;
 
-	tracing_off();
+	if (file)
+		tracer_tracing_off(file->tr);
+	else
+		tracing_off();
 }
 
 static int
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 45630a7..90f81d3 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -29,10 +29,8 @@
  * function and thus become accesible via perf.
  */
 #undef FTRACE_ENTRY_REG
-#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
-			 filter, regfn) \
-	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, regfn) \
+	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 /* not needed for this file */
 #undef __field_struct
@@ -41,9 +39,15 @@
 #undef __field
 #define __field(type, item)				type item;
 
+#undef __field_fn
+#define __field_fn(type, item)				type item;
+
 #undef __field_desc
 #define __field_desc(type, container, item)		type item;
 
+#undef __field_packed
+#define __field_packed(type, container, item)		type item;
+
 #undef __array
 #define __array(type, item, size)			type item[size];
 
@@ -60,7 +64,7 @@
 #define F_printk(fmt, args...) fmt, args
 
 #undef FTRACE_ENTRY
-#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
+#define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
 struct ____ftrace_##name {						\
 	tstruct								\
 };									\
@@ -73,76 +77,56 @@
 }
 
 #undef FTRACE_ENTRY_DUP
-#define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print, filter)	\
-	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print)		\
+	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 #include "trace_entries.h"
 
+#undef __field_ext
+#define __field_ext(_type, _item, _filter_type) {			\
+	.type = #_type, .name = #_item,					\
+	.size = sizeof(_type), .align = __alignof__(_type),		\
+	is_signed_type(_type), .filter_type = _filter_type },
+
+
+#undef __field_ext_packed
+#define __field_ext_packed(_type, _item, _filter_type) {	\
+	.type = #_type, .name = #_item,				\
+	.size = sizeof(_type), .align = 1,			\
+	is_signed_type(_type), .filter_type = _filter_type },
+
 #undef __field
-#define __field(type, item)						\
-	ret = trace_define_field(event_call, #type, #item,		\
-				 offsetof(typeof(field), item),		\
-				 sizeof(field.item),			\
-				 is_signed_type(type), filter_type);	\
-	if (ret)							\
-		return ret;
+#define __field(_type, _item) __field_ext(_type, _item, FILTER_OTHER)
+
+#undef __field_fn
+#define __field_fn(_type, _item) __field_ext(_type, _item, FILTER_TRACE_FN)
 
 #undef __field_desc
-#define __field_desc(type, container, item)	\
-	ret = trace_define_field(event_call, #type, #item,		\
-				 offsetof(typeof(field),		\
-					  container.item),		\
-				 sizeof(field.container.item),		\
-				 is_signed_type(type), filter_type);	\
-	if (ret)							\
-		return ret;
+#define __field_desc(_type, _container, _item) __field_ext(_type, _item, FILTER_OTHER)
+
+#undef __field_packed
+#define __field_packed(_type, _container, _item) __field_ext_packed(_type, _item, FILTER_OTHER)
 
 #undef __array
-#define __array(type, item, len)					\
-	do {								\
-		char *type_str = #type"["__stringify(len)"]";		\
-		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\
-		ret = trace_define_field(event_call, type_str, #item,	\
-				 offsetof(typeof(field), item),		\
-				 sizeof(field.item),			\
-				 is_signed_type(type), filter_type);	\
-		if (ret)						\
-			return ret;					\
-	} while (0);
+#define __array(_type, _item, _len) {					\
+	.type = #_type"["__stringify(_len)"]", .name = #_item,		\
+	.size = sizeof(_type[_len]), .align = __alignof__(_type),	\
+	is_signed_type(_type), .filter_type = FILTER_OTHER },
 
 #undef __array_desc
-#define __array_desc(type, container, item, len)			\
-	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
-	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
-				 offsetof(typeof(field),		\
-					  container.item),		\
-				 sizeof(field.container.item),		\
-				 is_signed_type(type), filter_type);	\
-	if (ret)							\
-		return ret;
+#define __array_desc(_type, _container, _item, _len) __array(_type, _item, _len)
 
 #undef __dynamic_array
-#define __dynamic_array(type, item)					\
-	ret = trace_define_field(event_call, #type "[]", #item,  \
-				 offsetof(typeof(field), item),		\
-				 0, is_signed_type(type), filter_type);\
-	if (ret)							\
-		return ret;
+#define __dynamic_array(_type, _item) {					\
+	.type = #_type "[]", .name = #_item,				\
+	.size = 0, .align = __alignof__(_type),				\
+	is_signed_type(_type), .filter_type = FILTER_OTHER },
 
 #undef FTRACE_ENTRY
-#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
-static int __init							\
-ftrace_define_fields_##name(struct trace_event_call *event_call)	\
-{									\
-	struct struct_name field;					\
-	int ret;							\
-	int filter_type = filter;					\
-									\
-	tstruct;							\
-									\
-	return ret;							\
-}
+#define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
+static struct trace_event_fields ftrace_event_fields_##name[] = {	\
+	tstruct								\
+	{} };
 
 #include "trace_entries.h"
 
@@ -152,9 +136,15 @@
 #undef __field
 #define __field(type, item)
 
+#undef __field_fn
+#define __field_fn(type, item)
+
 #undef __field_desc
 #define __field_desc(type, container, item)
 
+#undef __field_packed
+#define __field_packed(type, container, item)
+
 #undef __array
 #define __array(type, item, len)
 
@@ -168,12 +158,10 @@
 #define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
 
 #undef FTRACE_ENTRY_REG
-#define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\
-			 regfn)						\
-									\
-struct trace_event_class __refdata event_class_ftrace_##call = {	\
+#define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, regfn) \
+static struct trace_event_class __refdata event_class_ftrace_##call = {	\
 	.system			= __stringify(TRACE_SYSTEM),		\
-	.define_fields		= ftrace_define_fields_##call,		\
+	.fields_array		= ftrace_event_fields_##call,		\
 	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
 	.reg			= regfn,				\
 };									\
@@ -187,13 +175,13 @@
 	.print_fmt		= print,				\
 	.flags			= TRACE_EVENT_FL_IGNORE_ENABLE,		\
 };									\
-struct trace_event_call __used						\
-__attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
+static struct trace_event_call __used						\
+__section("_ftrace_events") *__event_##call = &event_##call;
 
 #undef FTRACE_ENTRY
-#define FTRACE_ENTRY(call, struct_name, etype, tstruct, print, filter)	\
+#define FTRACE_ENTRY(call, struct_name, etype, tstruct, print)		\
 	FTRACE_ENTRY_REG(call, struct_name, etype,			\
-			 PARAMS(tstruct), PARAMS(print), filter, NULL)
+			 PARAMS(tstruct), PARAMS(print), NULL)
 
 bool ftrace_event_is_function(struct trace_event_call *call)
 {
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index b611cd3..93e20ed 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -34,29 +34,37 @@
 	TRACE_FUNC_OPT_STACK	= 0x1,
 };
 
-static int allocate_ftrace_ops(struct trace_array *tr)
+int ftrace_allocate_ftrace_ops(struct trace_array *tr)
 {
 	struct ftrace_ops *ops;
 
+	/* The top level array uses the "global_ops" */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
+		return 0;
+
 	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
 	if (!ops)
 		return -ENOMEM;
 
-	/* Currently only the non stack verision is supported */
+	/* Currently only the non stack version is supported */
 	ops->func = function_trace_call;
 	ops->flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_PID;
 
 	tr->ops = ops;
 	ops->private = tr;
+
 	return 0;
 }
 
+void ftrace_free_ftrace_ops(struct trace_array *tr)
+{
+	kfree(tr->ops);
+	tr->ops = NULL;
+}
 
 int ftrace_create_function_files(struct trace_array *tr,
 				 struct dentry *parent)
 {
-	int ret;
-
 	/*
 	 * The top level array uses the "global_ops", and the files are
 	 * created on boot up.
@@ -64,9 +72,8 @@
 	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
 		return 0;
 
-	ret = allocate_ftrace_ops(tr);
-	if (ret)
-		return ret;
+	if (!tr->ops)
+		return -EINVAL;
 
 	ftrace_create_filter_files(tr->ops, parent);
 
@@ -76,8 +83,7 @@
 void ftrace_destroy_function_files(struct trace_array *tr)
 {
 	ftrace_destroy_filter_files(tr->ops);
-	kfree(tr->ops);
-	tr->ops = NULL;
+	ftrace_free_ftrace_ops(tr);
 }
 
 static int function_trace_init(struct trace_array *tr)
@@ -101,7 +107,7 @@
 
 	ftrace_init_array_ops(tr, func);
 
-	tr->trace_buffer.cpu = get_cpu();
+	tr->array_buffer.cpu = get_cpu();
 	put_cpu();
 
 	tracing_start_cmdline_record();
@@ -118,7 +124,7 @@
 
 static void function_trace_start(struct trace_array *tr)
 {
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 }
 
 static void
@@ -138,12 +144,12 @@
 	pc = preempt_count();
 	preempt_disable_notrace();
 
-	bit = trace_test_and_set_recursion(TRACE_FTRACE_START, TRACE_FTRACE_MAX);
+	bit = trace_test_and_set_recursion(TRACE_FTRACE_START);
 	if (bit < 0)
 		goto out;
 
 	cpu = smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	if (!atomic_read(&data->disabled)) {
 		local_save_flags(flags);
 		trace_function(tr, ip, parent_ip, flags, pc);
@@ -192,7 +198,7 @@
 	 */
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 
 	if (likely(disabled == 1)) {
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 78af971..60d6627 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -101,7 +101,7 @@
 {
 	struct trace_event_call *call = &event_funcgraph_entry;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ftrace_graph_ent_entry *entry;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
@@ -171,7 +171,7 @@
 
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 	if (likely(disabled == 1)) {
 		pc = preempt_count();
@@ -221,7 +221,7 @@
 {
 	struct trace_event_call *call = &event_funcgraph_exit;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ftrace_graph_ret_entry *entry;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
@@ -252,7 +252,7 @@
 
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 	if (likely(disabled == 1)) {
 		pc = preempt_count();
@@ -444,9 +444,9 @@
 			 * We need to consume the current entry to see
 			 * the next one.
 			 */
-			ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,
+			ring_buffer_consume(iter->array_buffer->buffer, iter->cpu,
 					    NULL, NULL);
-			event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,
+			event = ring_buffer_peek(iter->array_buffer->buffer, iter->cpu,
 						 NULL, NULL);
 		}
 
@@ -482,7 +482,7 @@
 
 	/* this is a leaf, now advance the iterator */
 	if (ring_iter)
-		ring_buffer_read(ring_iter, NULL);
+		ring_buffer_iter_advance(ring_iter);
 
 	return next;
 }
@@ -503,7 +503,7 @@
 {
 	unsigned long long usecs;
 
-	usecs = iter->ts - iter->trace_buffer->time_start;
+	usecs = iter->ts - iter->array_buffer->time_start;
 	do_div(usecs, NSEC_PER_USEC);
 
 	trace_seq_printf(s, "%9llu us |  ", usecs);
@@ -1336,13 +1336,13 @@
 
 static __init int init_graph_tracefs(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("max_graph_depth", 0644, d_tracer,
+	trace_create_file("max_graph_depth", 0644, NULL,
 			  NULL, &graph_depth_fops);
 
 	return 0;
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 164e5c6..d071fc2 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * trace_hwlatdetect.c - A simple Hardware Latency detector.
+ * trace_hwlat.c - A simple Hardware Latency detector.
  *
  * Use this tracer to detect large system latencies induced by the behavior of
  * certain underlying system hardware or firmware, independent of Linux itself.
@@ -83,6 +83,7 @@
 	u64			nmi_total_ts;	/* Total time spent in NMIs */
 	struct timespec64	timestamp;	/* wall time */
 	int			nmi_count;	/* # NMIs during this sample */
+	int			count;		/* # of iteratons over threash */
 };
 
 /* keep the global state somewhere. */
@@ -104,7 +105,7 @@
 {
 	struct trace_array *tr = hwlat_trace;
 	struct trace_event_call *call = &event_hwlat;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct hwlat_entry *entry;
 	unsigned long flags;
@@ -124,6 +125,7 @@
 	entry->timestamp		= sample->timestamp;
 	entry->nmi_total_ts		= sample->nmi_total_ts;
 	entry->nmi_count		= sample->nmi_count;
+	entry->count			= sample->count;
 
 	if (!call_filter_check_discard(call, entry, buffer, event))
 		trace_buffer_unlock_commit_nostack(buffer, event);
@@ -167,12 +169,14 @@
 static int get_sample(void)
 {
 	struct trace_array *tr = hwlat_trace;
+	struct hwlat_sample s;
 	time_type start, t1, t2, last_t2;
-	s64 diff, total, last_total = 0;
+	s64 diff, outer_diff, total, last_total = 0;
 	u64 sample = 0;
 	u64 thresh = tracing_thresh;
 	u64 outer_sample = 0;
 	int ret = -1;
+	unsigned int count = 0;
 
 	do_div(thresh, NSEC_PER_USEC); /* modifies interval value */
 
@@ -186,6 +190,7 @@
 
 	init_time(last_t2, 0);
 	start = time_get(); /* start timestamp */
+	outer_diff = 0;
 
 	do {
 
@@ -194,14 +199,14 @@
 
 		if (time_u64(last_t2)) {
 			/* Check the delta from outer loop (t2 to next t1) */
-			diff = time_to_us(time_sub(t1, last_t2));
+			outer_diff = time_to_us(time_sub(t1, last_t2));
 			/* This shouldn't happen */
-			if (diff < 0) {
+			if (outer_diff < 0) {
 				pr_err(BANNER "time running backwards\n");
 				goto out;
 			}
-			if (diff > outer_sample)
-				outer_sample = diff;
+			if (outer_diff > outer_sample)
+				outer_sample = outer_diff;
 		}
 		last_t2 = t2;
 
@@ -217,6 +222,12 @@
 		/* This checks the inner loop (t1 to t2) */
 		diff = time_to_us(time_sub(t2, t1));     /* current diff */
 
+		if (diff > thresh || outer_diff > thresh) {
+			if (!count)
+				ktime_get_real_ts64(&s.timestamp);
+			count++;
+		}
+
 		/* This shouldn't happen */
 		if (diff < 0) {
 			pr_err(BANNER "time running backwards\n");
@@ -236,7 +247,7 @@
 
 	/* If we exceed the threshold value, we have found a hardware latency */
 	if (sample > thresh || outer_sample > thresh) {
-		struct hwlat_sample s;
+		u64 latency;
 
 		ret = 1;
 
@@ -248,16 +259,18 @@
 		s.seqnum = hwlat_data.count;
 		s.duration = sample;
 		s.outer_duration = outer_sample;
-		ktime_get_real_ts64(&s.timestamp);
 		s.nmi_total_ts = nmi_total_ts;
 		s.nmi_count = nmi_count;
+		s.count = count;
 		trace_hwlat_sample(&s);
 
+		latency = max(sample, outer_sample);
+
 		/* Keep a running maximum ever recorded hardware latency */
-		if (sample > tr->max_latency)
-			tr->max_latency = sample;
-		if (outer_sample > tr->max_latency)
-			tr->max_latency = outer_sample;
+		if (latency > tr->max_latency) {
+			tr->max_latency = latency;
+			latency_fsnotify(tr);
+		}
 	}
 
 out:
@@ -277,7 +290,7 @@
 		return;
 	/*
 	 * If for some reason the user modifies the CPU affinity
-	 * of this thread, than stop migrating for the duration
+	 * of this thread, then stop migrating for the duration
 	 * of the current test.
 	 */
 	if (!cpumask_equal(current_mask, current->cpus_ptr))
@@ -359,7 +372,6 @@
 		return 0;
 
 	/* Just pick the first CPU on first iteration */
-	current_mask = &save_cpumask;
 	get_online_cpus();
 	cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask);
 	put_online_cpus();
@@ -526,14 +538,14 @@
  */
 static int init_tracefs(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 	struct dentry *top_dir;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return -ENOMEM;
 
-	top_dir = tracefs_create_dir("hwlat_detector", d_tracer);
+	top_dir = tracefs_create_dir("hwlat_detector", NULL);
 	if (!top_dir)
 		return -ENOMEM;
 
@@ -554,7 +566,7 @@
 	return 0;
 
  err:
-	tracefs_remove_recursive(top_dir);
+	tracefs_remove(top_dir);
 	return -ENOMEM;
 }
 
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index a745b0c..ee4571b 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -122,7 +122,7 @@
 	if (!irqs_disabled_flags(*flags) && !preempt_count())
 		return 0;
 
-	*data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	*data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&(*data)->disabled);
 
 	if (likely(disabled == 1))
@@ -167,7 +167,7 @@
 		per_cpu(tracing_cpu, cpu) = 0;
 
 	tr->max_latency = 0;
-	tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
+	tracing_reset_online_cpus(&irqsoff_trace->array_buffer);
 
 	return start_irqsoff_tracer(irqsoff_trace, set);
 }
@@ -382,7 +382,7 @@
 	if (per_cpu(tracing_cpu, cpu))
 		return;
 
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 
 	if (unlikely(!data) || atomic_read(&data->disabled))
 		return;
@@ -420,7 +420,7 @@
 	if (!tracer_enabled || !tracing_is_enabled())
 		return;
 
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 
 	if (unlikely(!data) ||
 	    !data->critical_start || atomic_read(&data->disabled))
@@ -562,6 +562,8 @@
 	/* non overwrite screws up the latency tracers */
 	set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
 	set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
+	/* without pause, we will produce garbage if another latency occurs */
+	set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1);
 
 	tr->max_latency = 0;
 	irqsoff_trace = tr;
@@ -583,11 +585,13 @@
 {
 	int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
 	int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
+	int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE;
 
 	stop_irqsoff_tracer(tr, is_graph(tr));
 
 	set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
 	set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
+	set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag);
 	ftrace_reset_array_ops(tr);
 
 	irqsoff_busy = false;
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index cca6504..9da7610 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -43,7 +43,7 @@
 	if (cpu_file == RING_BUFFER_ALL_CPUS) {
 		for_each_tracing_cpu(cpu) {
 			iter.buffer_iter[cpu] =
-			ring_buffer_read_prepare(iter.trace_buffer->buffer,
+			ring_buffer_read_prepare(iter.array_buffer->buffer,
 						 cpu, GFP_ATOMIC);
 			ring_buffer_read_start(iter.buffer_iter[cpu]);
 			tracing_iter_reset(&iter, cpu);
@@ -51,7 +51,7 @@
 	} else {
 		iter.cpu_file = cpu_file;
 		iter.buffer_iter[cpu_file] =
-			ring_buffer_read_prepare(iter.trace_buffer->buffer,
+			ring_buffer_read_prepare(iter.array_buffer->buffer,
 						 cpu_file, GFP_ATOMIC);
 		ring_buffer_read_start(iter.buffer_iter[cpu_file]);
 		tracing_iter_reset(&iter, cpu_file);
@@ -124,7 +124,7 @@
 	iter.buffer_iter = buffer_iter;
 
 	for_each_tracing_cpu(cpu) {
-		atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
+		atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
 	}
 
 	/* A negative skip_entries means skip all but the last entries */
@@ -139,7 +139,7 @@
 	ftrace_dump_buf(skip_entries, cpu_file);
 
 	for_each_tracing_cpu(cpu) {
-		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
+		atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
 	}
 
 	kdb_trap_printk--;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 5de084d..41dd173 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -22,16 +22,16 @@
 
 #define KPROBE_EVENT_SYSTEM "kprobes"
 #define KRETPROBE_MAXACTIVE_MAX 4096
-#define MAX_KPROBE_CMDLINE_SIZE 1024
 
 /* Kprobe early definition from command line */
 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
-static bool kprobe_boot_events_enabled __initdata;
 
 static int __init set_kprobe_boot_events(char *str)
 {
 	strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
-	return 0;
+	disable_tracing_selftest("running kprobe events");
+
+	return 1;
 }
 __setup("kprobe_event=", set_kprobe_boot_events);
 
@@ -107,9 +107,10 @@
 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
 						 struct module *mod)
 {
-	int len = strlen(mod->name);
+	int len = strlen(module_name(mod));
 	const char *name = trace_kprobe_symbol(tk);
-	return strncmp(mod->name, name, len) == 0 && name[len] == ':';
+
+	return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
 }
 
 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
@@ -693,7 +694,7 @@
 			if (ret)
 				pr_warn("Failed to re-register probe %s on %s: %d\n",
 					trace_probe_name(&tk->tp),
-					mod->name, ret);
+					module_name(mod), ret);
 		}
 	}
 	mutex_unlock(&event_mutex);
@@ -722,6 +723,9 @@
 	 *      p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 	 *  - Add kretprobe:
 	 *      r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
+	 *    Or
+	 *      p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
+	 *
 	 * Fetch args:
 	 *  $retval	: fetch return value
 	 *  $stack	: fetch stack address
@@ -751,7 +755,6 @@
 	switch (argv[0][0]) {
 	case 'r':
 		is_return = true;
-		flags |= TPARG_FL_RETURN;
 		break;
 	case 'p':
 		break;
@@ -809,12 +812,26 @@
 		symbol = kstrdup(argv[1], GFP_KERNEL);
 		if (!symbol)
 			return -ENOMEM;
+
+		tmp = strchr(symbol, '%');
+		if (tmp) {
+			if (!strcmp(tmp, "%return")) {
+				*tmp = '\0';
+				is_return = true;
+			} else {
+				trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
+				goto parse_error;
+			}
+		}
+
 		/* TODO: support .init module functions */
 		ret = traceprobe_split_symbol_offset(symbol, &offset);
 		if (ret || offset < 0 || offset > UINT_MAX) {
 			trace_probe_log_err(0, BAD_PROBE_ADDR);
 			goto parse_error;
 		}
+		if (is_return)
+			flags |= TPARG_FL_RETURN;
 		ret = kprobe_on_func_entry(NULL, symbol, offset);
 		if (ret == 0)
 			flags |= TPARG_FL_FENTRY;
@@ -908,6 +925,173 @@
 	return ret == -ECANCELED ? -EINVAL : ret;
 }
 
+static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
+{
+	return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe);
+}
+
+/**
+ * kprobe_event_cmd_init - Initialize a kprobe event command object
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @buf: A pointer to the buffer used to build the command
+ * @maxlen: The length of the buffer passed in @buf
+ *
+ * Initialize a synthetic event command object.  Use this before
+ * calling any of the other kprobe_event functions.
+ */
+void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
+{
+	dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
+			  trace_kprobe_run_command);
+}
+EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
+
+/**
+ * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @name: The name of the kprobe event
+ * @loc: The location of the kprobe event
+ * @kretprobe: Is this a return probe?
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
+ * adds a NULL to the end of the arg list.  If this function is used
+ * directly, make sure the last arg in the variable arg list is NULL.
+ *
+ * Generate a kprobe event command to be executed by
+ * kprobe_event_gen_cmd_end().  This function can be used to generate the
+ * complete command or only the first part of it; in the latter case,
+ * kprobe_event_add_fields() can be used to add more fields following this.
+ *
+ * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
+ * returns -EINVAL if @loc == NULL.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
+				 const char *name, const char *loc, ...)
+{
+	char buf[MAX_EVENT_NAME_LEN];
+	struct dynevent_arg arg;
+	va_list args;
+	int ret;
+
+	if (cmd->type != DYNEVENT_TYPE_KPROBE)
+		return -EINVAL;
+
+	if (!loc)
+		return -EINVAL;
+
+	if (kretprobe)
+		snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
+	else
+		snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
+
+	ret = dynevent_str_add(cmd, buf);
+	if (ret)
+		return ret;
+
+	dynevent_arg_init(&arg, 0);
+	arg.str = loc;
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	va_start(args, loc);
+	for (;;) {
+		const char *field;
+
+		field = va_arg(args, const char *);
+		if (!field)
+			break;
+
+		if (++cmd->n_fields > MAX_TRACE_ARGS) {
+			ret = -EINVAL;
+			break;
+		}
+
+		arg.str = field;
+		ret = dynevent_arg_add(cmd, &arg, NULL);
+		if (ret)
+			break;
+	}
+	va_end(args);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
+
+/**
+ * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the kprobe_event_add_fields() wrapper, which
+ * automatically adds a NULL to the end of the arg list.  If this
+ * function is used directly, make sure the last arg in the variable
+ * arg list is NULL.
+ *
+ * Add probe fields to an existing kprobe command using a variable
+ * list of args.  Fields are added in the same order they're listed.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
+{
+	struct dynevent_arg arg;
+	va_list args;
+	int ret = 0;
+
+	if (cmd->type != DYNEVENT_TYPE_KPROBE)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, 0);
+
+	va_start(args, cmd);
+	for (;;) {
+		const char *field;
+
+		field = va_arg(args, const char *);
+		if (!field)
+			break;
+
+		if (++cmd->n_fields > MAX_TRACE_ARGS) {
+			ret = -EINVAL;
+			break;
+		}
+
+		arg.str = field;
+		ret = dynevent_arg_add(cmd, &arg, NULL);
+		if (ret)
+			break;
+	}
+	va_end(args);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
+
+/**
+ * kprobe_event_delete - Delete a kprobe event
+ * @name: The name of the kprobe event to delete
+ *
+ * Delete a kprobe event with the give @name from kernel code rather
+ * than directly from the command line.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int kprobe_event_delete(const char *name)
+{
+	char buf[MAX_EVENT_NAME_LEN];
+
+	snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
+
+	return trace_run_command(buf, create_or_delete_trace_kprobe);
+}
+EXPORT_SYMBOL_GPL(kprobe_event_delete);
+
 static int trace_kprobe_release(struct dyn_event *ev)
 {
 	struct trace_kprobe *tk = to_trace_kprobe(ev);
@@ -999,15 +1183,18 @@
 {
 	struct dyn_event *ev = v;
 	struct trace_kprobe *tk;
+	unsigned long nmissed;
 
 	if (!is_trace_kprobe(ev))
 		return 0;
 
 	tk = to_trace_kprobe(ev);
+	nmissed = trace_kprobe_is_return(tk) ?
+		tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
 	seq_printf(m, "  %-44s %15lu %15lu\n",
 		   trace_probe_name(&tk->tp),
 		   trace_kprobe_nhit(tk),
-		   tk->rp.kp.nmissed);
+		   nmissed);
 
 	return 0;
 }
@@ -1042,55 +1229,33 @@
 
 /* Return the length of string -- including null terminal byte */
 static nokprobe_inline int
+fetch_store_strlen_user(unsigned long addr)
+{
+	const void __user *uaddr =  (__force const void __user *)addr;
+
+	return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
+}
+
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline int
 fetch_store_strlen(unsigned long addr)
 {
 	int ret, len = 0;
 	u8 c;
 
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	if (addr < TASK_SIZE)
+		return fetch_store_strlen_user(addr);
+#endif
+
 	do {
-		ret = probe_kernel_read(&c, (u8 *)addr + len, 1);
+		ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
 		len++;
 	} while (c && ret == 0 && len < MAX_STRING_SIZE);
 
 	return (ret < 0) ? ret : len;
 }
 
-/* Return the length of string -- including null terminal byte */
-static nokprobe_inline int
-fetch_store_strlen_user(unsigned long addr)
-{
-	const void __user *uaddr =  (__force const void __user *)addr;
-
-	return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE);
-}
-
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
- * length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string(unsigned long addr, void *dest, void *base)
-{
-	int maxlen = get_loc_len(*(u32 *)dest);
-	void *__dest;
-	long ret;
-
-	if (unlikely(!maxlen))
-		return -ENOMEM;
-
-	__dest = get_loc_data(dest, base);
-
-	/*
-	 * Try to get string again, since the string can be changed while
-	 * probing.
-	 */
-	ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen);
-	if (ret >= 0)
-		*(u32 *)dest = make_data_loc(ret, __dest - base);
-
-	return ret;
-}
-
 /*
  * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
  * with max length and relative data location.
@@ -1108,7 +1273,39 @@
 
 	__dest = get_loc_data(dest, base);
 
-	ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen);
+	ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
+	if (ret >= 0)
+		*(u32 *)dest = make_data_loc(ret, __dest - base);
+
+	return ret;
+}
+
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
+ * length and relative data location.
+ */
+static nokprobe_inline int
+fetch_store_string(unsigned long addr, void *dest, void *base)
+{
+	int maxlen = get_loc_len(*(u32 *)dest);
+	void *__dest;
+	long ret;
+
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	if ((unsigned long)addr < TASK_SIZE)
+		return fetch_store_string_user(addr, dest, base);
+#endif
+
+	if (unlikely(!maxlen))
+		return -ENOMEM;
+
+	__dest = get_loc_data(dest, base);
+
+	/*
+	 * Try to get string again, since the string can be changed while
+	 * probing.
+	 */
+	ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
 	if (ret >= 0)
 		*(u32 *)dest = make_data_loc(ret, __dest - base);
 
@@ -1116,17 +1313,21 @@
 }
 
 static nokprobe_inline int
-probe_mem_read(void *dest, void *src, size_t size)
-{
-	return probe_kernel_read(dest, src, size);
-}
-
-static nokprobe_inline int
 probe_mem_read_user(void *dest, void *src, size_t size)
 {
 	const void __user *uaddr =  (__force const void __user *)src;
 
-	return probe_user_read(dest, uaddr, size);
+	return copy_from_user_nofault(dest, uaddr, size);
+}
+
+static nokprobe_inline int
+probe_mem_read(void *dest, void *src, size_t size)
+{
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	if ((unsigned long)src < TASK_SIZE)
+		return probe_mem_read_user(dest, src, size);
+#endif
+	return copy_from_kernel_nofault(dest, src, size);
 }
 
 /* Note that we don't verify it, since the code does not come from user space */
@@ -1183,35 +1384,35 @@
 		    struct trace_event_file *trace_file)
 {
 	struct kprobe_trace_entry_head *entry;
-	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
-	int size, dsize, pc;
-	unsigned long irq_flags;
 	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+	struct trace_event_buffer fbuffer;
+	int dsize;
 
 	WARN_ON(call != trace_file->event_call);
 
 	if (trace_trigger_soft_disabled(trace_file))
 		return;
 
-	local_save_flags(irq_flags);
-	pc = preempt_count();
+	local_save_flags(fbuffer.flags);
+	fbuffer.pc = preempt_count();
+	fbuffer.trace_file = trace_file;
 
 	dsize = __get_data_size(&tk->tp, regs);
-	size = sizeof(*entry) + tk->tp.size + dsize;
 
-	event = trace_event_buffer_lock_reserve(&buffer, trace_file,
-						call->event.type,
-						size, irq_flags, pc);
-	if (!event)
+	fbuffer.event =
+		trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
+					call->event.type,
+					sizeof(*entry) + tk->tp.size + dsize,
+					fbuffer.flags, fbuffer.pc);
+	if (!fbuffer.event)
 		return;
 
-	entry = ring_buffer_event_data(event);
+	fbuffer.regs = regs;
+	entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
 	entry->ip = (unsigned long)tk->rp.kp.addr;
 	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
 
-	event_trigger_unlock_commit_regs(trace_file, buffer, event,
-					 entry, irq_flags, pc, regs);
+	trace_event_buffer_commit(&fbuffer);
 }
 
 static void
@@ -1231,36 +1432,35 @@
 		       struct trace_event_file *trace_file)
 {
 	struct kretprobe_trace_entry_head *entry;
-	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
-	int size, pc, dsize;
-	unsigned long irq_flags;
+	struct trace_event_buffer fbuffer;
 	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+	int dsize;
 
 	WARN_ON(call != trace_file->event_call);
 
 	if (trace_trigger_soft_disabled(trace_file))
 		return;
 
-	local_save_flags(irq_flags);
-	pc = preempt_count();
+	local_save_flags(fbuffer.flags);
+	fbuffer.pc = preempt_count();
+	fbuffer.trace_file = trace_file;
 
 	dsize = __get_data_size(&tk->tp, regs);
-	size = sizeof(*entry) + tk->tp.size + dsize;
-
-	event = trace_event_buffer_lock_reserve(&buffer, trace_file,
-						call->event.type,
-						size, irq_flags, pc);
-	if (!event)
+	fbuffer.event =
+		trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
+					call->event.type,
+					sizeof(*entry) + tk->tp.size + dsize,
+					fbuffer.flags, fbuffer.pc);
+	if (!fbuffer.event)
 		return;
 
-	entry = ring_buffer_event_data(event);
+	fbuffer.regs = regs;
+	entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
 	entry->func = (unsigned long)tk->rp.kp.addr;
 	entry->ret_ip = (unsigned long)ri->ret_addr;
 	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
 
-	event_trigger_unlock_commit_regs(trace_file, buffer, event,
-					 entry, irq_flags, pc, regs);
+	trace_event_buffer_commit(&fbuffer);
 }
 
 static void
@@ -1563,16 +1763,28 @@
 	.trace		= print_kprobe_event
 };
 
+static struct trace_event_fields kretprobe_fields_array[] = {
+	{ .type = TRACE_FUNCTION_TYPE,
+	  .define_fields = kretprobe_event_define_fields },
+	{}
+};
+
+static struct trace_event_fields kprobe_fields_array[] = {
+	{ .type = TRACE_FUNCTION_TYPE,
+	  .define_fields = kprobe_event_define_fields },
+	{}
+};
+
 static inline void init_trace_event_call(struct trace_kprobe *tk)
 {
 	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
 
 	if (trace_kprobe_is_return(tk)) {
 		call->event.funcs = &kretprobe_funcs;
-		call->class->define_fields = kretprobe_event_define_fields;
+		call->class->fields_array = kretprobe_fields_array;
 	} else {
 		call->event.funcs = &kprobe_funcs;
-		call->class->define_fields = kprobe_event_define_fields;
+		call->class->fields_array = kprobe_fields_array;
 	}
 
 	call->flags = TRACE_EVENT_FL_KPROBE;
@@ -1685,8 +1897,6 @@
 		ret = trace_run_command(cmd, create_or_delete_trace_kprobe);
 		if (ret)
 			pr_warn("Failed to add event(%d): %s\n", ret, cmd);
-		else
-			kprobe_boot_events_enabled = true;
 
 		cmd = p;
 	}
@@ -1694,11 +1904,12 @@
 	enable_boot_kprobe_events();
 }
 
-/* Make a tracefs interface for controlling probe points */
-static __init int init_kprobe_trace(void)
+/*
+ * Register dynevent at core_initcall. This allows kernel to setup kprobe
+ * events in postcore_initcall without tracefs.
+ */
+static __init int init_kprobe_trace_early(void)
 {
-	struct dentry *d_tracer;
-	struct dentry *entry;
 	int ret;
 
 	ret = dyn_event_register(&trace_kprobe_ops);
@@ -1708,11 +1919,21 @@
 	if (register_module_notifier(&trace_kprobe_module_nb))
 		return -EINVAL;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	return 0;
+}
+core_initcall(init_kprobe_trace_early);
+
+/* Make a tracefs interface for controlling probe points */
+static __init int init_kprobe_trace(void)
+{
+	int ret;
+	struct dentry *entry;
+
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
+	entry = tracefs_create_file("kprobe_events", 0644, NULL,
 				    NULL, &kprobe_events_ops);
 
 	/* Event list interface */
@@ -1720,7 +1941,7 @@
 		pr_warn("Could not create tracefs 'kprobe_events' entry\n");
 
 	/* Profile interface */
-	entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
+	entry = tracefs_create_file("kprobe_profile", 0444, NULL,
 				    NULL, &kprobe_profile_ops);
 
 	if (!entry)
@@ -1760,10 +1981,8 @@
 	if (tracing_is_disabled())
 		return -ENODEV;
 
-	if (kprobe_boot_events_enabled) {
-		pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n");
+	if (tracing_selftest_disabled)
 		return 0;
-	}
 
 	target = kprobe_trace_selftest_target;
 
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b038801..84582bf 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -32,7 +32,7 @@
 	overrun_detected = false;
 	prev_overruns = 0;
 
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 }
 
 static int mmio_trace_init(struct trace_array *tr)
@@ -122,7 +122,7 @@
 static unsigned long count_overruns(struct trace_iterator *iter)
 {
 	unsigned long cnt = atomic_xchg(&dropped_count, 0);
-	unsigned long over = ring_buffer_overruns(iter->trace_buffer->buffer);
+	unsigned long over = ring_buffer_overruns(iter->array_buffer->buffer);
 
 	if (over > prev_overruns)
 		cnt += over - prev_overruns;
@@ -297,7 +297,7 @@
 				struct mmiotrace_rw *rw)
 {
 	struct trace_event_call *call = &event_mmiotrace_rw;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_rw *entry;
 	int pc = preempt_count();
@@ -318,7 +318,7 @@
 void mmio_trace_rw(struct mmiotrace_rw *rw)
 {
 	struct trace_array *tr = mmio_trace_array;
-	struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
+	struct trace_array_cpu *data = per_cpu_ptr(tr->array_buffer.data, smp_processor_id());
 	__trace_mmiotrace_rw(tr, data, rw);
 }
 
@@ -327,7 +327,7 @@
 				struct mmiotrace_map *map)
 {
 	struct trace_event_call *call = &event_mmiotrace_map;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_map *entry;
 	int pc = preempt_count();
@@ -351,7 +351,7 @@
 	struct trace_array_cpu *data;
 
 	preempt_disable();
-	data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
+	data = per_cpu_ptr(tr->array_buffer.data, smp_processor_id());
 	__trace_mmiotrace_map(tr, data, map);
 	preempt_enable();
 }
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index a0a4590..000e9dc 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -20,7 +20,7 @@
 
 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
 
-static int next_event_type = __TRACE_LAST_TYPE + 1;
+static int next_event_type = __TRACE_LAST_TYPE;
 
 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
 {
@@ -274,6 +274,21 @@
 }
 EXPORT_SYMBOL(trace_print_array_seq);
 
+const char *
+trace_print_hex_dump_seq(struct trace_seq *p, const char *prefix_str,
+			 int prefix_type, int rowsize, int groupsize,
+			 const void *buf, size_t len, bool ascii)
+{
+	const char *ret = trace_seq_buffer_ptr(p);
+
+	trace_seq_putc(p, '\n');
+	trace_seq_hex_dump(p, prefix_str, prefix_type,
+			   rowsize, groupsize, buf, len, ascii);
+	trace_seq_putc(p, 0);
+	return ret;
+}
+EXPORT_SYMBOL(trace_print_hex_dump_seq);
+
 int trace_raw_output_prep(struct trace_iterator *iter,
 			  struct trace_event *trace_event)
 {
@@ -378,7 +393,7 @@
 	if (mm) {
 		const struct vm_area_struct *vma;
 
-		down_read(&mm->mmap_sem);
+		mmap_read_lock(mm);
 		vma = find_vma(mm, ip);
 		if (vma) {
 			file = vma->vm_file;
@@ -390,7 +405,7 @@
 				trace_seq_printf(s, "[+0x%lx]",
 						 ip - vmstart);
 		}
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 	}
 	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 		trace_seq_printf(s, " <" IP_FMT ">", ip);
@@ -523,7 +538,7 @@
 	struct trace_array *tr = iter->tr;
 	unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 	unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
-	unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
+	unsigned long long abs_ts = iter->ts - iter->array_buffer->time_start;
 	unsigned long long rel_ts = next_ts - iter->ts;
 	struct trace_seq *s = &iter->seq;
 
@@ -602,22 +617,19 @@
 
 int trace_print_lat_context(struct trace_iterator *iter)
 {
+	struct trace_entry *entry, *next_entry;
 	struct trace_array *tr = iter->tr;
-	/* trace_find_next_entry will reset ent_size */
-	int ent_size = iter->ent_size;
 	struct trace_seq *s = &iter->seq;
-	u64 next_ts;
-	struct trace_entry *entry = iter->ent,
-			   *next_entry = trace_find_next_entry(iter, NULL,
-							       &next_ts);
 	unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
+	u64 next_ts;
 
-	/* Restore the original ent_size */
-	iter->ent_size = ent_size;
-
+	next_entry = trace_find_next_entry(iter, NULL, &next_ts);
 	if (!next_entry)
 		next_ts = iter->ts;
 
+	/* trace_find_next_entry() may change iter->ent */
+	entry = iter->ent;
+
 	if (verbose) {
 		char comm[TASK_COMM_LEN];
 
@@ -663,11 +675,11 @@
 static int trace_search_list(struct list_head **list)
 {
 	struct trace_event *e;
-	int last = __TRACE_LAST_TYPE;
+	int next = __TRACE_LAST_TYPE;
 
 	if (list_empty(&ftrace_event_list)) {
 		*list = &ftrace_event_list;
-		return last + 1;
+		return next;
 	}
 
 	/*
@@ -675,17 +687,17 @@
 	 * lets see if somebody freed one.
 	 */
 	list_for_each_entry(e, &ftrace_event_list, list) {
-		if (e->type != last + 1)
+		if (e->type != next)
 			break;
-		last++;
+		next++;
 	}
 
 	/* Did we used up all 65 thousand events??? */
-	if ((last + 1) > TRACE_EVENT_TYPE_MAX)
+	if (next > TRACE_EVENT_TYPE_MAX)
 		return 0;
 
 	*list = &e->list;
-	return last + 1;
+	return next;
 }
 
 void trace_event_read_lock(void)
@@ -1143,12 +1155,12 @@
 
 	trace_assign_type(field, entry);
 
-	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
+	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld count:%d",
 			 field->seqnum,
 			 field->duration,
 			 field->outer_duration,
 			 (long long)field->timestamp.tv_sec,
-			 field->timestamp.tv_nsec);
+			 field->timestamp.tv_nsec, field->count);
 
 	if (field->nmi_count) {
 		/*
diff --git a/kernel/trace/trace_preemptirq.c b/kernel/trace/trace_preemptirq.c
index 26b06b0..f493804 100644
--- a/kernel/trace/trace_preemptirq.c
+++ b/kernel/trace/trace_preemptirq.c
@@ -19,6 +19,24 @@
 /* Per-cpu variable to prevent redundant calls when IRQs already off */
 static DEFINE_PER_CPU(int, tracing_irq_cpu);
 
+/*
+ * Like trace_hardirqs_on() but without the lockdep invocation. This is
+ * used in the low level entry code where the ordering vs. RCU is important
+ * and lockdep uses a staged approach which splits the lockdep hardirq
+ * tracking into a RCU on and a RCU off section.
+ */
+void trace_hardirqs_on_prepare(void)
+{
+	if (this_cpu_read(tracing_irq_cpu)) {
+		if (!in_nmi())
+			trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);
+		tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
+		this_cpu_write(tracing_irq_cpu, 0);
+	}
+}
+EXPORT_SYMBOL(trace_hardirqs_on_prepare);
+NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
+
 void trace_hardirqs_on(void)
 {
 	if (this_cpu_read(tracing_irq_cpu)) {
@@ -28,21 +46,41 @@
 		this_cpu_write(tracing_irq_cpu, 0);
 	}
 
+	lockdep_hardirqs_on_prepare(CALLER_ADDR0);
 	lockdep_hardirqs_on(CALLER_ADDR0);
 }
 EXPORT_SYMBOL(trace_hardirqs_on);
 NOKPROBE_SYMBOL(trace_hardirqs_on);
 
+/*
+ * Like trace_hardirqs_off() but without the lockdep invocation. This is
+ * used in the low level entry code where the ordering vs. RCU is important
+ * and lockdep uses a staged approach which splits the lockdep hardirq
+ * tracking into a RCU on and a RCU off section.
+ */
+void trace_hardirqs_off_finish(void)
+{
+	if (!this_cpu_read(tracing_irq_cpu)) {
+		this_cpu_write(tracing_irq_cpu, 1);
+		tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
+		if (!in_nmi())
+			trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);
+	}
+
+}
+EXPORT_SYMBOL(trace_hardirqs_off_finish);
+NOKPROBE_SYMBOL(trace_hardirqs_off_finish);
+
 void trace_hardirqs_off(void)
 {
+	lockdep_hardirqs_off(CALLER_ADDR0);
+
 	if (!this_cpu_read(tracing_irq_cpu)) {
 		this_cpu_write(tracing_irq_cpu, 1);
 		tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
 		if (!in_nmi())
 			trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
 	}
-
-	lockdep_hardirqs_off(CALLER_ADDR0);
 }
 EXPORT_SYMBOL(trace_hardirqs_off);
 NOKPROBE_SYMBOL(trace_hardirqs_off);
@@ -56,6 +94,7 @@
 		this_cpu_write(tracing_irq_cpu, 0);
 	}
 
+	lockdep_hardirqs_on_prepare(CALLER_ADDR0);
 	lockdep_hardirqs_on(CALLER_ADDR0);
 }
 EXPORT_SYMBOL(trace_hardirqs_on_caller);
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index d4e31e9..ff32476 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -96,7 +96,7 @@
 		if (val == MODULE_STATE_COMING)
 			hold_module_trace_bprintk_format(start, end);
 	}
-	return 0;
+	return NOTIFY_OK;
 }
 
 /*
@@ -174,7 +174,7 @@
 module_trace_bprintk_format_notify(struct notifier_block *self,
 		unsigned long val, void *data)
 {
-	return 0;
+	return NOTIFY_OK;
 }
 static inline const char **
 find_next_mod_format(int start_index, void *v, const char **fmt, loff_t *pos)
@@ -367,13 +367,13 @@
 
 static __init int init_trace_printk_function_export(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("printk_formats", 0444, d_tracer,
+	trace_create_file("printk_formats", 0444, NULL,
 				    NULL, &ftrace_formats_fops);
 
 	return 0;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 23e85cb..1d31bc4 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1006,7 +1006,7 @@
 	INIT_LIST_HEAD(&tp->event->class.fields);
 	INIT_LIST_HEAD(&tp->event->probes);
 	INIT_LIST_HEAD(&tp->list);
-	list_add(&tp->event->probes, &tp->list);
+	list_add(&tp->list, &tp->event->probes);
 
 	call = trace_probe_event_call(tp);
 	call->class = &tp->event->class;
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index bab9e0d..6d41e20 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -16,7 +16,6 @@
 #include <linux/tracefs.h>
 #include <linux/types.h>
 #include <linux/string.h>
-#include <linux/ctype.h>
 #include <linux/ptrace.h>
 #include <linux/perf_event.h>
 #include <linux/kprobes.h>
@@ -236,7 +235,7 @@
 	struct trace_event_call		call;
 	struct list_head 		files;
 	struct list_head		probes;
-	struct trace_uprobe_filter	filter[0];
+	struct trace_uprobe_filter	filter[];
 };
 
 struct trace_probe {
@@ -348,18 +347,6 @@
 #define trace_probe_for_each_link_rcu(pos, tp)	\
 	list_for_each_entry_rcu(pos, &(tp)->event->files, list)
 
-/* Check the name is good for event/group/fields */
-static inline bool is_good_name(const char *name)
-{
-	if (!isalpha(*name) && *name != '_')
-		return false;
-	while (*++name != '\0') {
-		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
-			return false;
-	}
-	return true;
-}
-
 #define TPARG_FL_RETURN BIT(0)
 #define TPARG_FL_KERNEL BIT(1)
 #define TPARG_FL_FENTRY BIT(2)
@@ -404,6 +391,7 @@
 	C(MAXACT_TOO_BIG,	"Maxactive is too big"),		\
 	C(BAD_PROBE_ADDR,	"Invalid probed address or symbol"),	\
 	C(BAD_RETPROBE,		"Retprobe address must be an function entry"), \
+	C(BAD_ADDR_SUFFIX,	"Invalid probed address suffix"), \
 	C(NO_GROUP_NAME,	"Group name is not specified"),		\
 	C(GROUP_TOO_LONG,	"Group name is too long"),		\
 	C(BAD_GROUP_NAME,	"Group name must follow the same rules as C identifiers"), \
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 617e297..97b10bb 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -82,7 +82,7 @@
 	if (cpu != wakeup_current_cpu)
 		goto out_enable;
 
-	*data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	*data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&(*data)->disabled);
 	if (unlikely(disabled != 1))
 		goto out;
@@ -378,7 +378,7 @@
 			   unsigned long flags, int pc)
 {
 	struct trace_event_call *call = &event_context_switch;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
 
@@ -408,7 +408,7 @@
 	struct trace_event_call *call = &event_wakeup;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_WAKE,
 					  sizeof(*entry), flags, pc);
@@ -459,7 +459,7 @@
 
 	/* disable local data, not wakeup_cpu data */
 	cpu = raw_smp_processor_id();
-	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 	if (likely(disabled != 1))
 		goto out;
 
@@ -471,7 +471,7 @@
 		goto out_unlock;
 
 	/* The task we are waiting for is waking up */
-	data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
+	data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu);
 
 	__trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc);
 	tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc);
@@ -494,7 +494,7 @@
 	arch_spin_unlock(&wakeup_lock);
 	local_irq_restore(flags);
 out:
-	atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 }
 
 static void __wakeup_reset(struct trace_array *tr)
@@ -513,7 +513,7 @@
 {
 	unsigned long flags;
 
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 	local_irq_save(flags);
 	arch_spin_lock(&wakeup_lock);
@@ -551,7 +551,7 @@
 		return;
 
 	pc = preempt_count();
-	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 	if (unlikely(disabled != 1))
 		goto out;
 
@@ -583,7 +583,7 @@
 
 	local_save_flags(flags);
 
-	data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
+	data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu);
 	data->preempt_timestamp = ftrace_now(cpu);
 	tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc);
 	__trace_stack(wakeup_trace, flags, 0, pc);
@@ -598,7 +598,7 @@
 out_locked:
 	arch_spin_unlock(&wakeup_lock);
 out:
-	atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 }
 
 static void start_wakeup_tracer(struct trace_array *tr)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 0838c29..6f28b8b 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -23,7 +23,7 @@
 	return 0;
 }
 
-static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
+static int trace_test_buffer_cpu(struct array_buffer *buf, int cpu)
 {
 	struct ring_buffer_event *event;
 	struct trace_entry *entry;
@@ -60,7 +60,7 @@
  * Test the trace buffer to see if all the elements
  * are still sane.
  */
-static int __maybe_unused trace_test_buffer(struct trace_buffer *buf, unsigned long *count)
+static int __maybe_unused trace_test_buffer(struct array_buffer *buf, unsigned long *count)
 {
 	unsigned long flags, cnt = 0;
 	int cpu, ret = 0;
@@ -362,7 +362,7 @@
 	msleep(100);
 
 	/* we should have nothing in the buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 	if (ret)
 		goto out;
 
@@ -383,7 +383,7 @@
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 
 	ftrace_enabled = 1;
 	tracing_start();
@@ -687,7 +687,7 @@
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 
 	ftrace_enabled = 1;
 	trace->reset(tr);
@@ -773,7 +773,7 @@
 	 * Simulate the init() callback but we attach a watchdog callback
 	 * to detect and recover from possible hangs
 	 */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 	set_graph_array(tr);
 	ret = register_ftrace_graph(&fgraph_ops);
 	if (ret) {
@@ -787,7 +787,7 @@
 
 	/* Have we just recovered from a hang? */
 	if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
-		tracing_selftest_disabled = true;
+		disable_tracing_selftest("recovering from a hang");
 		ret = -1;
 		goto out;
 	}
@@ -795,7 +795,7 @@
 	tracing_stop();
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 
 	/* Need to also simulate the tr->reset to remove this fgraph_ops */
 	tracing_stop_cmdline_record();
@@ -853,7 +853,7 @@
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&tr->max_buffer, &count);
 	trace->reset(tr);
@@ -915,7 +915,7 @@
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&tr->max_buffer, &count);
 	trace->reset(tr);
@@ -981,7 +981,7 @@
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (ret)
 		goto out;
 
@@ -1011,7 +1011,7 @@
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (ret)
 		goto out;
 
@@ -1141,7 +1141,7 @@
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&tr->max_buffer, &count);
 
@@ -1182,7 +1182,7 @@
 	/* stop the tracing. */
 	tracing_stop();
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 6b1c562..1d84fcc 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -30,9 +30,6 @@
 /* How much buffer is left on the trace_seq? */
 #define TRACE_SEQ_BUF_LEFT(s) seq_buf_buffer_left(&(s)->seq)
 
-/* How much buffer is written? */
-#define TRACE_SEQ_BUF_USED(s) seq_buf_used(&(s)->seq)
-
 /*
  * trace_seq should work with being initialized with 0s.
  */
@@ -376,3 +373,33 @@
 	return seq_buf_to_user(&s->seq, ubuf, cnt);
 }
 EXPORT_SYMBOL_GPL(trace_seq_to_user);
+
+int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str,
+		       int prefix_type, int rowsize, int groupsize,
+		       const void *buf, size_t len, bool ascii)
+{
+	unsigned int save_len = s->seq.len;
+
+	if (s->full)
+		return 0;
+
+	__trace_seq_init(s);
+
+	if (TRACE_SEQ_BUF_LEFT(s) < 1) {
+		s->full = 1;
+		return 0;
+	}
+
+	seq_buf_hex_dump(&(s->seq), prefix_str,
+		   prefix_type, rowsize, groupsize,
+		   buf, len, ascii);
+
+	if (unlikely(seq_buf_has_overflowed(&s->seq))) {
+		s->seq.len = save_len;
+		s->full = 1;
+		return 0;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL(trace_seq_hex_dump);
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index c557f42..c408423 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -515,9 +515,8 @@
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 int
-stack_trace_sysctl(struct ctl_table *table, int write,
-		   void __user *buffer, size_t *lenp,
-		   loff_t *ppos)
+stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
+		   size_t *lenp, loff_t *ppos)
 {
 	int was_enabled;
 	int ret;
@@ -555,20 +554,20 @@
 
 static __init int stack_trace_init(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("stack_max_size", 0644, d_tracer,
+	trace_create_file("stack_max_size", 0644, NULL,
 			&stack_trace_max_size, &stack_max_size_fops);
 
-	trace_create_file("stack_trace", 0444, d_tracer,
+	trace_create_file("stack_trace", 0444, NULL,
 			NULL, &stack_trace_fops);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-	trace_create_file("stack_trace_filter", 0644, d_tracer,
+	trace_create_file("stack_trace_filter", 0644, NULL,
 			  &trace_ops, &stack_trace_filter_fops);
 #endif
 
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 3c9c17f..8d141c3 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -72,9 +72,7 @@
 	kfree(session);
 }
 
-typedef int (*cmp_stat_t)(void *, void *);
-
-static int insert_stat(struct rb_root *root, void *stat, cmp_stat_t cmp)
+static int insert_stat(struct rb_root *root, void *stat, cmp_func_t cmp)
 {
 	struct rb_node **new = &(root->rb_node), *parent = NULL;
 	struct stat_node *data;
@@ -112,7 +110,7 @@
  * This one will force an insertion as right-most node
  * in the rbtree.
  */
-static int dummy_cmp(void *p1, void *p2)
+static int dummy_cmp(const void *p1, const void *p2)
 {
 	return -1;
 }
@@ -278,13 +276,13 @@
 
 static int tracing_stat_init(void)
 {
-	struct dentry *d_tracing;
+	int ret;
 
-	d_tracing = tracing_init_dentry();
-	if (IS_ERR(d_tracing))
+	ret = tracing_init_dentry();
+	if (ret)
 		return -ENODEV;
 
-	stat_dir = tracefs_create_dir("trace_stat", d_tracing);
+	stat_dir = tracefs_create_dir("trace_stat", NULL);
 	if (!stat_dir) {
 		pr_warn("Could not create tracefs 'trace_stat' entry\n");
 		return -ENOMEM;
diff --git a/kernel/trace/trace_stat.h b/kernel/trace/trace_stat.h
index 8786d17..31d7dc5 100644
--- a/kernel/trace/trace_stat.h
+++ b/kernel/trace/trace_stat.h
@@ -16,7 +16,7 @@
 	void			*(*stat_start)(struct tracer_stat *trace);
 	void			*(*stat_next)(void *prev, int idx);
 	/* Compare two entries for stats sorting */
-	int			(*stat_cmp)(void *p1, void *p2);
+	cmp_func_t		stat_cmp;
 	/* Print a stat entry */
 	int			(*stat_show)(struct seq_file *s, void *p);
 	/* Release an entry */
diff --git a/kernel/trace/trace_synth.h b/kernel/trace/trace_synth.h
new file mode 100644
index 0000000..4007fe9
--- /dev/null
+++ b/kernel/trace/trace_synth.h
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef __TRACE_SYNTH_H
+#define __TRACE_SYNTH_H
+
+#include "trace_dynevent.h"
+
+#define SYNTH_SYSTEM		"synthetic"
+#define SYNTH_FIELDS_MAX	32
+
+#define STR_VAR_LEN_MAX		MAX_FILTER_STR_VAL /* must be multiple of sizeof(u64) */
+
+struct synth_field {
+	char *type;
+	char *name;
+	size_t size;
+	unsigned int offset;
+	unsigned int field_pos;
+	bool is_signed;
+	bool is_string;
+	bool is_dynamic;
+};
+
+struct synth_event {
+	struct dyn_event			devent;
+	int					ref;
+	char					*name;
+	struct synth_field			**fields;
+	unsigned int				n_fields;
+	struct synth_field			**dynamic_fields;
+	unsigned int				n_dynamic_fields;
+	unsigned int				n_u64;
+	struct trace_event_class		class;
+	struct trace_event_call			call;
+	struct tracepoint			*tp;
+	struct module				*mod;
+};
+
+extern struct synth_event *find_synth_event(const char *name);
+
+#endif /* __TRACE_SYNTH_H */
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index fa8fbff..d85a2f0 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -7,6 +7,7 @@
 #include <linux/module.h>	/* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */
 #include <linux/ftrace.h>
 #include <linux/perf_event.h>
+#include <linux/xarray.h>
 #include <asm/syscall.h>
 
 #include "trace_output.h"
@@ -30,6 +31,7 @@
 extern struct syscall_metadata *__start_syscalls_metadata[];
 extern struct syscall_metadata *__stop_syscalls_metadata[];
 
+static DEFINE_XARRAY(syscalls_metadata_sparse);
 static struct syscall_metadata **syscalls_metadata;
 
 #ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
@@ -101,6 +103,9 @@
 
 static struct syscall_metadata *syscall_nr_to_meta(int nr)
 {
+	if (IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR))
+		return xa_load(&syscalls_metadata_sparse, (unsigned long)nr);
+
 	if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
 		return NULL;
 
@@ -198,11 +203,10 @@
 
 extern char *__bad_type_size(void);
 
-#define SYSCALL_FIELD(type, field, name)				\
-	sizeof(type) != sizeof(trace.field) ?				\
-		__bad_type_size() :					\
-		#type, #name, offsetof(typeof(trace), field),		\
-		sizeof(trace.field), is_signed_type(type)
+#define SYSCALL_FIELD(_type, _name) {					\
+	.type = #_type, .name = #_name,					\
+	.size = sizeof(_type), .align = __alignof__(_type),		\
+	.is_signed = is_signed_type(_type), .filter_type = FILTER_OTHER }
 
 static int __init
 __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
@@ -269,42 +273,23 @@
 {
 	struct syscall_trace_enter trace;
 	struct syscall_metadata *meta = call->data;
-	int ret;
-	int i;
 	int offset = offsetof(typeof(trace), args);
-
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
-				 FILTER_OTHER);
-	if (ret)
-		return ret;
+	int ret = 0;
+	int i;
 
 	for (i = 0; i < meta->nb_args; i++) {
 		ret = trace_define_field(call, meta->types[i],
 					 meta->args[i], offset,
 					 sizeof(unsigned long), 0,
 					 FILTER_OTHER);
+		if (ret)
+			break;
 		offset += sizeof(unsigned long);
 	}
 
 	return ret;
 }
 
-static int __init syscall_exit_define_fields(struct trace_event_call *call)
-{
-	struct syscall_trace_exit trace;
-	int ret;
-
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
-				 FILTER_OTHER);
-	if (ret)
-		return ret;
-
-	ret = trace_define_field(call, SYSCALL_FIELD(long, ret, ret),
-				 FILTER_OTHER);
-
-	return ret;
-}
-
 static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 {
 	struct trace_array *tr = data;
@@ -312,7 +297,7 @@
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long irq_flags;
 	unsigned long args[6];
 	int pc;
@@ -340,7 +325,7 @@
 	local_save_flags(irq_flags);
 	pc = preempt_count();
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer,
 			sys_data->enter_event->event.type, size, irq_flags, pc);
 	if (!event)
@@ -362,7 +347,7 @@
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long irq_flags;
 	int pc;
 	int syscall_nr;
@@ -386,7 +371,7 @@
 	local_save_flags(irq_flags);
 	pc = preempt_count();
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer,
 			sys_data->exit_event->event.type, sizeof(*entry),
 			irq_flags, pc);
@@ -502,6 +487,13 @@
 	return id;
 }
 
+static struct trace_event_fields __refdata syscall_enter_fields_array[] = {
+	SYSCALL_FIELD(int, __syscall_nr),
+	{ .type = TRACE_FUNCTION_TYPE,
+	  .define_fields = syscall_enter_define_fields },
+	{}
+};
+
 struct trace_event_functions enter_syscall_print_funcs = {
 	.trace		= print_syscall_enter,
 };
@@ -513,7 +505,7 @@
 struct trace_event_class __refdata event_class_syscall_enter = {
 	.system		= "syscalls",
 	.reg		= syscall_enter_register,
-	.define_fields	= syscall_enter_define_fields,
+	.fields_array	= syscall_enter_fields_array,
 	.get_fields	= syscall_get_enter_fields,
 	.raw_init	= init_syscall_trace,
 };
@@ -521,7 +513,11 @@
 struct trace_event_class __refdata event_class_syscall_exit = {
 	.system		= "syscalls",
 	.reg		= syscall_exit_register,
-	.define_fields	= syscall_exit_define_fields,
+	.fields_array	= (struct trace_event_fields[]){
+		SYSCALL_FIELD(int, __syscall_nr),
+		SYSCALL_FIELD(long, ret),
+		{}
+	},
 	.fields		= LIST_HEAD_INIT(event_class_syscall_exit.fields),
 	.raw_init	= init_syscall_trace,
 };
@@ -536,12 +532,16 @@
 	struct syscall_metadata *meta;
 	unsigned long addr;
 	int i;
+	void *ret;
 
-	syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata),
-				    GFP_KERNEL);
-	if (!syscalls_metadata) {
-		WARN_ON(1);
-		return;
+	if (!IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR)) {
+		syscalls_metadata = kcalloc(NR_syscalls,
+					sizeof(*syscalls_metadata),
+					GFP_KERNEL);
+		if (!syscalls_metadata) {
+			WARN_ON(1);
+			return;
+		}
 	}
 
 	for (i = 0; i < NR_syscalls; i++) {
@@ -551,7 +551,16 @@
 			continue;
 
 		meta->syscall_nr = i;
-		syscalls_metadata[i] = meta;
+
+		if (!IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR)) {
+			syscalls_metadata[i] = meta;
+		} else {
+			ret = xa_store(&syscalls_metadata_sparse, i, meta,
+					GFP_KERNEL);
+			WARN(xa_is_err(ret),
+				"Syscall memory allocation failed\n");
+		}
+
 	}
 }
 
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index b515db0..9900d4e 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -532,7 +532,7 @@
 
 /*
  * Argument syntax:
- *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
+ *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS]
  */
 static int trace_uprobe_create(int argc, const char **argv)
 {
@@ -621,6 +621,19 @@
 		}
 	}
 
+	/* Check if there is %return suffix */
+	tmp = strchr(arg, '%');
+	if (tmp) {
+		if (!strcmp(tmp, "%return")) {
+			*tmp = '\0';
+			is_return = true;
+		} else {
+			trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
+			ret = -EINVAL;
+			goto fail_address_parse;
+		}
+	}
+
 	/* Parse uprobe offset. */
 	ret = kstrtoul(arg, 0, &offset);
 	if (ret) {
@@ -935,8 +948,8 @@
 				struct trace_event_file *trace_file)
 {
 	struct uprobe_trace_entry_head *entry;
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	void *data;
 	int size, esize;
 	struct trace_event_call *call = trace_probe_event_call(&tu->tp);
@@ -1299,6 +1312,7 @@
 		return 0;
 
 	list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
+		tu = container_of(pos, struct trace_uprobe, tp);
 		err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
 		if (err) {
 			uprobe_perf_close(call, event);
@@ -1337,8 +1351,15 @@
 	int size, esize;
 	int rctx;
 
-	if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
-		return;
+	if (bpf_prog_array_valid(call)) {
+		u32 ret;
+
+		preempt_disable();
+		ret = trace_call_bpf(call, regs);
+		preempt_enable();
+		if (!ret)
+			return;
+	}
 
 	esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 
@@ -1453,7 +1474,6 @@
 	default:
 		return 0;
 	}
-	return 0;
 }
 
 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
@@ -1532,12 +1552,17 @@
 	.trace		= print_uprobe_event
 };
 
+static struct trace_event_fields uprobe_fields_array[] = {
+	{ .type = TRACE_FUNCTION_TYPE,
+	  .define_fields = uprobe_event_define_fields },
+	{}
+};
+
 static inline void init_trace_event_call(struct trace_uprobe *tu)
 {
 	struct trace_event_call *call = trace_probe_event_call(&tu->tp);
-
 	call->event.funcs = &uprobe_funcs;
-	call->class->define_fields = uprobe_event_define_fields;
+	call->class->fields_array = uprobe_fields_array;
 
 	call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
 	call->class->reg = trace_uprobe_register;
@@ -1618,21 +1643,20 @@
 /* Make a trace interface for controling probe points */
 static __init int init_uprobe_trace(void)
 {
-	struct dentry *d_tracer;
 	int ret;
 
 	ret = dyn_event_register(&trace_uprobe_ops);
 	if (ret)
 		return ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("uprobe_events", 0644, d_tracer,
+	trace_create_file("uprobe_events", 0644, NULL,
 				    NULL, &uprobe_events_ops);
 	/* Profile interface */
-	trace_create_file("uprobe_profile", 0444, d_tracer,
+	trace_create_file("uprobe_profile", 0444, NULL,
 				    NULL, &uprobe_profile_ops);
 	return 0;
 }
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 9e31bfc..51a9d11 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -15,6 +15,7 @@
 #include <linux/jhash.h>
 #include <linux/slab.h>
 #include <linux/sort.h>
+#include <linux/kmemleak.h>
 
 #include "tracing_map.h"
 #include "trace.h"
@@ -260,7 +261,7 @@
  * to use cmp_fn.
  *
  * A key can be a subset of a compound key; for that purpose, the
- * offset param is used to describe where within the the compound key
+ * offset param is used to describe where within the compound key
  * the key referenced by this key field resides.
  *
  * Return: The index identifying the field in the map and associated
@@ -283,7 +284,7 @@
 	return idx;
 }
 
-void tracing_map_array_clear(struct tracing_map_array *a)
+static void tracing_map_array_clear(struct tracing_map_array *a)
 {
 	unsigned int i;
 
@@ -294,7 +295,7 @@
 		memset(a->pages[i], 0, PAGE_SIZE);
 }
 
-void tracing_map_array_free(struct tracing_map_array *a)
+static void tracing_map_array_free(struct tracing_map_array *a)
 {
 	unsigned int i;
 
@@ -307,6 +308,7 @@
 	for (i = 0; i < a->n_pages; i++) {
 		if (!a->pages[i])
 			break;
+		kmemleak_free(a->pages[i]);
 		free_page((unsigned long)a->pages[i]);
 	}
 
@@ -316,7 +318,7 @@
 	kfree(a);
 }
 
-struct tracing_map_array *tracing_map_array_alloc(unsigned int n_elts,
+static struct tracing_map_array *tracing_map_array_alloc(unsigned int n_elts,
 						  unsigned int entry_size)
 {
 	struct tracing_map_array *a;
@@ -342,6 +344,7 @@
 		a->pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
 		if (!a->pages[i])
 			goto free;
+		kmemleak_alloc(a->pages[i], PAGE_SIZE, 1, GFP_KERNEL);
 	}
  out:
 	return a;
@@ -834,29 +837,35 @@
 	return err;
 }
 
-static int cmp_entries_dup(const struct tracing_map_sort_entry **a,
-			   const struct tracing_map_sort_entry **b)
+static int cmp_entries_dup(const void *A, const void *B)
 {
+	const struct tracing_map_sort_entry *a, *b;
 	int ret = 0;
 
-	if (memcmp((*a)->key, (*b)->key, (*a)->elt->map->key_size))
+	a = *(const struct tracing_map_sort_entry **)A;
+	b = *(const struct tracing_map_sort_entry **)B;
+
+	if (memcmp(a->key, b->key, a->elt->map->key_size))
 		ret = 1;
 
 	return ret;
 }
 
-static int cmp_entries_sum(const struct tracing_map_sort_entry **a,
-			   const struct tracing_map_sort_entry **b)
+static int cmp_entries_sum(const void *A, const void *B)
 {
 	const struct tracing_map_elt *elt_a, *elt_b;
+	const struct tracing_map_sort_entry *a, *b;
 	struct tracing_map_sort_key *sort_key;
 	struct tracing_map_field *field;
 	tracing_map_cmp_fn_t cmp_fn;
 	void *val_a, *val_b;
 	int ret = 0;
 
-	elt_a = (*a)->elt;
-	elt_b = (*b)->elt;
+	a = *(const struct tracing_map_sort_entry **)A;
+	b = *(const struct tracing_map_sort_entry **)B;
+
+	elt_a = a->elt;
+	elt_b = b->elt;
 
 	sort_key = &elt_a->map->sort_key;
 
@@ -873,18 +882,21 @@
 	return ret;
 }
 
-static int cmp_entries_key(const struct tracing_map_sort_entry **a,
-			   const struct tracing_map_sort_entry **b)
+static int cmp_entries_key(const void *A, const void *B)
 {
 	const struct tracing_map_elt *elt_a, *elt_b;
+	const struct tracing_map_sort_entry *a, *b;
 	struct tracing_map_sort_key *sort_key;
 	struct tracing_map_field *field;
 	tracing_map_cmp_fn_t cmp_fn;
 	void *val_a, *val_b;
 	int ret = 0;
 
-	elt_a = (*a)->elt;
-	elt_b = (*b)->elt;
+	a = *(const struct tracing_map_sort_entry **)A;
+	b = *(const struct tracing_map_sort_entry **)B;
+
+	elt_a = a->elt;
+	elt_b = b->elt;
 
 	sort_key = &elt_a->map->sort_key;
 
@@ -989,10 +1001,8 @@
 			   struct tracing_map_sort_key *primary_key,
 			   struct tracing_map_sort_key *secondary_key)
 {
-	int (*primary_fn)(const struct tracing_map_sort_entry **,
-			  const struct tracing_map_sort_entry **);
-	int (*secondary_fn)(const struct tracing_map_sort_entry **,
-			    const struct tracing_map_sort_entry **);
+	int (*primary_fn)(const void *, const void *);
+	int (*secondary_fn)(const void *, const void *);
 	unsigned i, start = 0, n_sub = 1;
 
 	if (is_key(map, primary_key->field_idx))
@@ -1061,8 +1071,7 @@
 			     unsigned int n_sort_keys,
 			     struct tracing_map_sort_entry ***sort_entries)
 {
-	int (*cmp_entries_fn)(const struct tracing_map_sort_entry **,
-			      const struct tracing_map_sort_entry **);
+	int (*cmp_entries_fn)(const void *, const void *);
 	struct tracing_map_sort_entry *sort_entry, **entries;
 	int i, n_entries, ret;
 
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 5d87b21..2dff7f1 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -15,12 +15,57 @@
 #include <linux/sched/task.h>
 #include <linux/static_key.h>
 
+enum tp_func_state {
+	TP_FUNC_0,
+	TP_FUNC_1,
+	TP_FUNC_2,
+	TP_FUNC_N,
+};
+
 extern tracepoint_ptr_t __start___tracepoints_ptrs[];
 extern tracepoint_ptr_t __stop___tracepoints_ptrs[];
 
 DEFINE_SRCU(tracepoint_srcu);
 EXPORT_SYMBOL_GPL(tracepoint_srcu);
 
+enum tp_transition_sync {
+	TP_TRANSITION_SYNC_1_0_1,
+	TP_TRANSITION_SYNC_N_2_1,
+
+	_NR_TP_TRANSITION_SYNC,
+};
+
+struct tp_transition_snapshot {
+	unsigned long rcu;
+	unsigned long srcu;
+	bool ongoing;
+};
+
+/* Protected by tracepoints_mutex */
+static struct tp_transition_snapshot tp_transition_snapshot[_NR_TP_TRANSITION_SYNC];
+
+static void tp_rcu_get_state(enum tp_transition_sync sync)
+{
+	struct tp_transition_snapshot *snapshot = &tp_transition_snapshot[sync];
+
+	/* Keep the latest get_state snapshot. */
+	snapshot->rcu = get_state_synchronize_rcu();
+	snapshot->srcu = start_poll_synchronize_srcu(&tracepoint_srcu);
+	snapshot->ongoing = true;
+}
+
+static void tp_rcu_cond_sync(enum tp_transition_sync sync)
+{
+	struct tp_transition_snapshot *snapshot = &tp_transition_snapshot[sync];
+
+	if (!snapshot->ongoing)
+		return;
+	cond_synchronize_rcu(snapshot->rcu);
+	if (!poll_state_synchronize_srcu(&tracepoint_srcu, snapshot->srcu))
+		synchronize_srcu(&tracepoint_srcu);
+	snapshot->ongoing = false;
+}
+
 /* Set to 1 to enable tracepoint debug output */
 static const int tracepoint_debug;
 
@@ -50,7 +95,7 @@
  */
 struct tp_probes {
 	struct rcu_head rcu;
-	struct tracepoint_func probes[0];
+	struct tracepoint_func probes[];
 };
 
 /* Called in removal of a func but failed to allocate a new tp_funcs */
@@ -268,6 +313,32 @@
 }
 
 /*
+ * Count the number of functions (enum tp_func_state) in a tp_funcs array.
+ */
+static enum tp_func_state nr_func_state(const struct tracepoint_func *tp_funcs)
+{
+	if (!tp_funcs)
+		return TP_FUNC_0;
+	if (!tp_funcs[1].func)
+		return TP_FUNC_1;
+	if (!tp_funcs[2].func)
+		return TP_FUNC_2;
+	return TP_FUNC_N;	/* 3 or more */
+}
+
+static void tracepoint_update_call(struct tracepoint *tp, struct tracepoint_func *tp_funcs)
+{
+	void *func = tp->iterator;
+
+	/* Synthetic events do not have static call sites */
+	if (!tp->static_call_key)
+		return;
+	if (nr_func_state(tp_funcs) == TP_FUNC_1)
+		func = tp_funcs[0].func;
+	__static_call_update(tp->static_call_key, tp->static_call_tramp, func);
+}
+
+/*
  * Add the probe function to a tracepoint.
  */
 static int tracepoint_add_func(struct tracepoint *tp,
@@ -297,9 +368,42 @@
 	 * a pointer to it.  This array is referenced by __DO_TRACE from
 	 * include/linux/tracepoint.h using rcu_dereference_sched().
 	 */
-	rcu_assign_pointer(tp->funcs, tp_funcs);
-	if (!static_key_enabled(&tp->key))
-		static_key_slow_inc(&tp->key);
+	switch (nr_func_state(tp_funcs)) {
+	case TP_FUNC_1:		/* 0->1 */
+		/*
+		 * Make sure new static func never uses old data after a
+		 * 1->0->1 transition sequence.
+		 */
+		tp_rcu_cond_sync(TP_TRANSITION_SYNC_1_0_1);
+		/* Set static call to first function */
+		tracepoint_update_call(tp, tp_funcs);
+		/* Both iterator and static call handle NULL tp->funcs */
+		rcu_assign_pointer(tp->funcs, tp_funcs);
+		static_key_enable(&tp->key);
+		break;
+	case TP_FUNC_2:		/* 1->2 */
+		/* Set iterator static call */
+		tracepoint_update_call(tp, tp_funcs);
+		/*
+		 * Iterator callback installed before updating tp->funcs.
+		 * Requires ordering between RCU assign/dereference and
+		 * static call update/call.
+		 */
+		fallthrough;
+	case TP_FUNC_N:		/* N->N+1 (N>1) */
+		rcu_assign_pointer(tp->funcs, tp_funcs);
+		/*
+		 * Make sure static func never uses incorrect data after a
+		 * N->...->2->1 (N>1) transition sequence.
+		 */
+		if (tp_funcs[0].data != old[0].data)
+			tp_rcu_get_state(TP_TRANSITION_SYNC_N_2_1);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+
 	release_probes(old);
 	return 0;
 }
@@ -325,15 +429,53 @@
 		/* Failed allocating new tp_funcs, replaced func with stub */
 		return 0;
 
-	if (!tp_funcs) {
+	switch (nr_func_state(tp_funcs)) {
+	case TP_FUNC_0:		/* 1->0 */
 		/* Removed last function */
 		if (tp->unregfunc && static_key_enabled(&tp->key))
 			tp->unregfunc();
 
-		if (static_key_enabled(&tp->key))
-			static_key_slow_dec(&tp->key);
+		static_key_disable(&tp->key);
+		/* Set iterator static call */
+		tracepoint_update_call(tp, tp_funcs);
+		/* Both iterator and static call handle NULL tp->funcs */
+		rcu_assign_pointer(tp->funcs, NULL);
+		/*
+		 * Make sure new static func never uses old data after a
+		 * 1->0->1 transition sequence.
+		 */
+		tp_rcu_get_state(TP_TRANSITION_SYNC_1_0_1);
+		break;
+	case TP_FUNC_1:		/* 2->1 */
+		rcu_assign_pointer(tp->funcs, tp_funcs);
+		/*
+		 * Make sure static func never uses incorrect data after a
+		 * N->...->2->1 (N>2) transition sequence. If the first
+		 * element's data has changed, then force the synchronization
+		 * to prevent current readers that have loaded the old data
+		 * from calling the new function.
+		 */
+		if (tp_funcs[0].data != old[0].data)
+			tp_rcu_get_state(TP_TRANSITION_SYNC_N_2_1);
+		tp_rcu_cond_sync(TP_TRANSITION_SYNC_N_2_1);
+		/* Set static call to first function */
+		tracepoint_update_call(tp, tp_funcs);
+		break;
+	case TP_FUNC_2:		/* N->N-1 (N>2) */
+		fallthrough;
+	case TP_FUNC_N:
+		rcu_assign_pointer(tp->funcs, tp_funcs);
+		/*
+		 * Make sure static func never uses incorrect data after a
+		 * N->...->2->1 (N>2) transition sequence.
+		 */
+		if (tp_funcs[0].data != old[0].data)
+			tp_rcu_get_state(TP_TRANSITION_SYNC_N_2_1);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
 	}
-	rcu_assign_pointer(tp->funcs, tp_funcs);
 	release_probes(old);
 	return 0;
 }
@@ -596,7 +738,7 @@
 	case MODULE_STATE_UNFORMED:
 		break;
 	}
-	return ret;
+	return notifier_from_errno(ret);
 }
 
 static struct notifier_block tracepoint_module_nb = {
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 7be3e75..fd2f7a0 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -24,6 +24,7 @@
 	const struct cred *tcred;
 	u64 utime, stime, utimescaled, stimescaled;
 	u64 delta;
+	time64_t btime;
 
 	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
 
@@ -32,14 +33,15 @@
 	/* Convert to micro seconds */
 	do_div(delta, NSEC_PER_USEC);
 	stats->ac_etime = delta;
-	/* Convert to seconds for btime */
-	do_div(delta, USEC_PER_SEC);
-	stats->ac_btime = get_seconds() - delta;
-	if (thread_group_leader(tsk)) {
+	/* Convert to seconds for btime (note y2106 limit) */
+	btime = ktime_get_real_seconds() - div_u64(delta, USEC_PER_SEC);
+	stats->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX);
+	stats->ac_btime64 = btime;
+
+	if (tsk->flags & PF_EXITING)
 		stats->ac_exitcode = tsk->exit_code;
-		if (tsk->flags & PF_FORKNOEXEC)
-			stats->ac_flag |= AFORK;
-	}
+	if (thread_group_leader(tsk) && (tsk->flags & PF_FORKNOEXEC))
+		stats->ac_flag |= AFORK;
 	if (tsk->flags & PF_SUPERPRIV)
 		stats->ac_flag |= ASU;
 	if (tsk->flags & PF_DUMPCORE)
diff --git a/kernel/ucount.c b/kernel/ucount.c
index a53cc2b..11b1596 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -69,6 +69,7 @@
 	UCOUNT_ENTRY("max_net_namespaces"),
 	UCOUNT_ENTRY("max_mnt_namespaces"),
 	UCOUNT_ENTRY("max_cgroup_namespaces"),
+	UCOUNT_ENTRY("max_time_namespaces"),
 #ifdef CONFIG_INOTIFY_USER
 	UCOUNT_ENTRY("max_inotify_instances"),
 	UCOUNT_ENTRY("max_inotify_watches"),
@@ -81,6 +82,8 @@
 {
 #ifdef CONFIG_SYSCTL
 	struct ctl_table *tbl;
+
+	BUILD_BUG_ON(ARRAY_SIZE(user_table) != UCOUNT_COUNTS + 1);
 	setup_sysctl_set(&ns->set, &set_root, set_is_seen);
 	tbl = kmemdup(user_table, sizeof(user_table), GFP_KERNEL);
 	if (tbl) {
diff --git a/kernel/umh.c b/kernel/umh.c
index b8c524d..3f64661 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -27,8 +27,6 @@
 #include <linux/ptrace.h>
 #include <linux/async.h>
 #include <linux/uaccess.h>
-#include <linux/shmem_fs.h>
-#include <linux/pipe_fs_i.h>
 
 #include <trace/events/module.h>
 
@@ -39,8 +37,6 @@
 static kernel_cap_t usermodehelper_inheritable = CAP_FULL_SET;
 static DEFINE_SPINLOCK(umh_sysctl_lock);
 static DECLARE_RWSEM(umhelper_sem);
-static LIST_HEAD(umh_list);
-static DEFINE_MUTEX(umh_list_lock);
 
 static void call_usermodehelper_freeinfo(struct subprocess_info *info)
 {
@@ -111,16 +107,9 @@
 
 	commit_creds(new);
 
-	sub_info->pid = task_pid_nr(current);
-	if (sub_info->file) {
-		retval = do_execve_file(sub_info->file,
-					sub_info->argv, sub_info->envp);
-		if (!retval)
-			current->flags |= PF_UMH;
-	} else
-		retval = do_execve(getname_kernel(sub_info->path),
-				   (const char __user *const __user *)sub_info->argv,
-				   (const char __user *const __user *)sub_info->envp);
+	retval = kernel_execve(sub_info->path,
+			       (const char *const *)sub_info->argv,
+			       (const char *const *)sub_info->envp);
 out:
 	sub_info->retval = retval;
 	/*
@@ -139,37 +128,16 @@
 {
 	pid_t pid;
 
-	/* If SIGCLD is ignored kernel_wait4 won't populate the status. */
+	/* If SIGCLD is ignored do_wait won't populate the status. */
 	kernel_sigaction(SIGCHLD, SIG_DFL);
 	pid = kernel_thread(call_usermodehelper_exec_async, sub_info, SIGCHLD);
-	if (pid < 0) {
+	if (pid < 0)
 		sub_info->retval = pid;
-	} else {
-		int ret = -ECHILD;
-		/*
-		 * Normally it is bogus to call wait4() from in-kernel because
-		 * wait4() wants to write the exit code to a userspace address.
-		 * But call_usermodehelper_exec_sync() always runs as kernel
-		 * thread (workqueue) and put_user() to a kernel address works
-		 * OK for kernel threads, due to their having an mm_segment_t
-		 * which spans the entire address space.
-		 *
-		 * Thus the __user pointer cast is valid here.
-		 */
-		kernel_wait4(pid, (int __user *)&ret, 0, NULL);
-
-		/*
-		 * If ret is 0, either call_usermodehelper_exec_async failed and
-		 * the real error code is already in sub_info->retval or
-		 * sub_info->retval is 0 anyway, so don't mess with it then.
-		 */
-		if (ret)
-			sub_info->retval = ret;
-	}
+	else
+		kernel_wait(pid, &sub_info->retval);
 
 	/* Restore default kernel sig handler */
 	kernel_sigaction(SIGCHLD, SIG_IGN);
-
 	umh_complete(sub_info);
 }
 
@@ -414,140 +382,6 @@
 }
 EXPORT_SYMBOL(call_usermodehelper_setup);
 
-struct subprocess_info *call_usermodehelper_setup_file(struct file *file,
-		int (*init)(struct subprocess_info *info, struct cred *new),
-		void (*cleanup)(struct subprocess_info *info), void *data)
-{
-	struct subprocess_info *sub_info;
-	struct umh_info *info = data;
-	const char *cmdline = (info->cmdline) ? info->cmdline : "usermodehelper";
-
-	sub_info = kzalloc(sizeof(struct subprocess_info), GFP_KERNEL);
-	if (!sub_info)
-		return NULL;
-
-	sub_info->argv = argv_split(GFP_KERNEL, cmdline, NULL);
-	if (!sub_info->argv) {
-		kfree(sub_info);
-		return NULL;
-	}
-
-	INIT_WORK(&sub_info->work, call_usermodehelper_exec_work);
-	sub_info->path = "none";
-	sub_info->file = file;
-	sub_info->init = init;
-	sub_info->cleanup = cleanup;
-	sub_info->data = data;
-	return sub_info;
-}
-
-static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
-{
-	struct umh_info *umh_info = info->data;
-	struct file *from_umh[2];
-	struct file *to_umh[2];
-	int err;
-
-	/* create pipe to send data to umh */
-	err = create_pipe_files(to_umh, 0);
-	if (err)
-		return err;
-	err = replace_fd(0, to_umh[0], 0);
-	fput(to_umh[0]);
-	if (err < 0) {
-		fput(to_umh[1]);
-		return err;
-	}
-
-	/* create pipe to receive data from umh */
-	err = create_pipe_files(from_umh, 0);
-	if (err) {
-		fput(to_umh[1]);
-		replace_fd(0, NULL, 0);
-		return err;
-	}
-	err = replace_fd(1, from_umh[1], 0);
-	fput(from_umh[1]);
-	if (err < 0) {
-		fput(to_umh[1]);
-		replace_fd(0, NULL, 0);
-		fput(from_umh[0]);
-		return err;
-	}
-
-	umh_info->pipe_to_umh = to_umh[1];
-	umh_info->pipe_from_umh = from_umh[0];
-	return 0;
-}
-
-static void umh_clean_and_save_pid(struct subprocess_info *info)
-{
-	struct umh_info *umh_info = info->data;
-
-	/* cleanup if umh_pipe_setup() was successful but exec failed */
-	if (info->pid && info->retval) {
-		fput(umh_info->pipe_to_umh);
-		fput(umh_info->pipe_from_umh);
-	}
-
-	argv_free(info->argv);
-	umh_info->pid = info->pid;
-}
-
-/**
- * fork_usermode_blob - fork a blob of bytes as a usermode process
- * @data: a blob of bytes that can be do_execv-ed as a file
- * @len: length of the blob
- * @info: information about usermode process (shouldn't be NULL)
- *
- * If info->cmdline is set it will be used as command line for the
- * user process, else "usermodehelper" is used.
- *
- * Returns either negative error or zero which indicates success
- * in executing a blob of bytes as a usermode process. In such
- * case 'struct umh_info *info' is populated with two pipes
- * and a pid of the process. The caller is responsible for health
- * check of the user process, killing it via pid, and closing the
- * pipes when user process is no longer needed.
- */
-int fork_usermode_blob(void *data, size_t len, struct umh_info *info)
-{
-	struct subprocess_info *sub_info;
-	struct file *file;
-	ssize_t written;
-	loff_t pos = 0;
-	int err;
-
-	file = shmem_kernel_file_setup("", len, 0);
-	if (IS_ERR(file))
-		return PTR_ERR(file);
-
-	written = kernel_write(file, data, len, &pos);
-	if (written != len) {
-		err = written;
-		if (err >= 0)
-			err = -ENOMEM;
-		goto out;
-	}
-
-	err = -ENOMEM;
-	sub_info = call_usermodehelper_setup_file(file, umh_pipe_setup,
-						  umh_clean_and_save_pid, info);
-	if (!sub_info)
-		goto out;
-
-	err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
-	if (!err) {
-		mutex_lock(&umh_list_lock);
-		list_add(&info->list, &umh_list);
-		mutex_unlock(&umh_list_lock);
-	}
-out:
-	fput(file);
-	return err;
-}
-EXPORT_SYMBOL_GPL(fork_usermode_blob);
-
 /**
  * call_usermodehelper_exec - start a usermode application
  * @sub_info: information about the subprocessa
@@ -650,7 +484,7 @@
 EXPORT_SYMBOL(call_usermodehelper);
 
 static int proc_cap_handler(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	unsigned long cap_array[_KERNEL_CAPABILITY_U32S];
@@ -709,26 +543,6 @@
 	return 0;
 }
 
-void __exit_umh(struct task_struct *tsk)
-{
-	struct umh_info *info;
-	pid_t pid = tsk->pid;
-
-	mutex_lock(&umh_list_lock);
-	list_for_each_entry(info, &umh_list, list) {
-		if (info->pid == pid) {
-			list_del(&info->list);
-			mutex_unlock(&umh_list_lock);
-			goto out;
-		}
-	}
-	mutex_unlock(&umh_list_lock);
-	return;
-out:
-	if (info->cleanup)
-		info->cleanup(info);
-}
-
 struct ctl_table usermodehelper_table[] = {
 	{
 		.procname	= "bset",
diff --git a/kernel/up.c b/kernel/up.c
index 8e8551c..4edd549 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -14,7 +14,8 @@
 {
 	unsigned long flags;
 
-	WARN_ON(cpu != 0);
+	if (cpu != 0)
+		return -ENXIO;
 
 	local_irq_save(flags);
 	func(info);
@@ -68,9 +69,8 @@
  * Preemption is disabled here to make sure the cond_func is called under the
  * same condtions in UP and SMP.
  */
-void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
-			   smp_call_func_t func, void *info, bool wait,
-			   gfp_t gfp_flags, const struct cpumask *mask)
+void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
+			   void *info, bool wait, const struct cpumask *mask)
 {
 	unsigned long flags;
 
@@ -84,11 +84,10 @@
 }
 EXPORT_SYMBOL(on_each_cpu_cond_mask);
 
-void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
-		      smp_call_func_t func, void *info, bool wait,
-		      gfp_t gfp_flags)
+void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
+		      void *info, bool wait)
 {
-	on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags, NULL);
+	on_each_cpu_cond_mask(cond_func, func, info, wait, NULL);
 }
 EXPORT_SYMBOL(on_each_cpu_cond);
 
diff --git a/kernel/user.c b/kernel/user.c
index 5235d7f..b1635d9 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -82,7 +82,7 @@
 #define uidhashentry(uid)	(uidhash_table + __uidhashfn((__kuid_val(uid))))
 
 static struct kmem_cache *uid_cachep;
-struct hlist_head uidhash_table[UIDHASH_SZ];
+static struct hlist_head uidhash_table[UIDHASH_SZ];
 
 /*
  * The uidhash_lock is mostly taken from process context, but it is
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 8eadadc..ce396ea 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -106,6 +106,7 @@
 	if (!ns)
 		goto fail_dec;
 
+	ns->parent_could_setfcap = cap_raised(new->cap_effective, CAP_SETFCAP);
 	ret = ns_alloc_inum(&ns->ns);
 	if (ret)
 		goto fail_free;
@@ -515,7 +516,7 @@
  *
  *	When there is no mapping defined for the user-namespace projid
  *	pair INVALID_PROJID is returned.  Callers are expected to test
- *	for and handle handle INVALID_PROJID being returned.  INVALID_PROJID
+ *	for and handle INVALID_PROJID being returned.  INVALID_PROJID
  *	may be tested for using projid_valid().
  */
 kprojid_t make_kprojid(struct user_namespace *ns, projid_t projid)
@@ -841,6 +842,60 @@
 	return 0;
 }
 
+/**
+ * verify_root_map() - check the uid 0 mapping
+ * @file: idmapping file
+ * @map_ns: user namespace of the target process
+ * @new_map: requested idmap
+ *
+ * If a process requests mapping parent uid 0 into the new ns, verify that the
+ * process writing the map had the CAP_SETFCAP capability as the target process
+ * will be able to write fscaps that are valid in ancestor user namespaces.
+ *
+ * Return: true if the mapping is allowed, false if not.
+ */
+static bool verify_root_map(const struct file *file,
+			    struct user_namespace *map_ns,
+			    struct uid_gid_map *new_map)
+{
+	int idx;
+	const struct user_namespace *file_ns = file->f_cred->user_ns;
+	struct uid_gid_extent *extent0 = NULL;
+
+	for (idx = 0; idx < new_map->nr_extents; idx++) {
+		if (new_map->nr_extents <= UID_GID_MAP_MAX_BASE_EXTENTS)
+			extent0 = &new_map->extent[idx];
+		else
+			extent0 = &new_map->forward[idx];
+		if (extent0->lower_first == 0)
+			break;
+
+		extent0 = NULL;
+	}
+
+	if (!extent0)
+		return true;
+
+	if (map_ns == file_ns) {
+		/* The process unshared its ns and is writing to its own
+		 * /proc/self/uid_map.  User already has full capabilites in
+		 * the new namespace.  Verify that the parent had CAP_SETFCAP
+		 * when it unshared.
+		 * */
+		if (!file_ns->parent_could_setfcap)
+			return false;
+	} else {
+		/* Process p1 is writing to uid_map of p2, who is in a child
+		 * user namespace to p1's.  Verify that the opener of the map
+		 * file has CAP_SETFCAP against the parent of the new map
+		 * namespace */
+		if (!file_ns_capable(file, map_ns->parent, CAP_SETFCAP))
+			return false;
+	}
+
+	return true;
+}
+
 static ssize_t map_write(struct file *file, const char __user *buf,
 			 size_t count, loff_t *ppos,
 			 int cap_setid,
@@ -848,7 +903,7 @@
 			 struct uid_gid_map *parent_map)
 {
 	struct seq_file *seq = file->private_data;
-	struct user_namespace *ns = seq->private;
+	struct user_namespace *map_ns = seq->private;
 	struct uid_gid_map new_map;
 	unsigned idx;
 	struct uid_gid_extent extent;
@@ -895,7 +950,7 @@
 	/*
 	 * Adjusting namespace settings requires capabilities on the target.
 	 */
-	if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN))
+	if (cap_valid(cap_setid) && !file_ns_capable(file, map_ns, CAP_SYS_ADMIN))
 		goto out;
 
 	/* Parse the user data */
@@ -965,7 +1020,7 @@
 
 	ret = -EPERM;
 	/* Validate the user is allowed to use user id's mapped to. */
-	if (!new_idmap_permitted(file, ns, cap_setid, &new_map))
+	if (!new_idmap_permitted(file, map_ns, cap_setid, &new_map))
 		goto out;
 
 	ret = -EPERM;
@@ -1086,6 +1141,10 @@
 				struct uid_gid_map *new_map)
 {
 	const struct cred *cred = file->f_cred;
+
+	if (cap_setid == CAP_SETUID && !verify_root_map(file, ns, new_map))
+		return false;
+
 	/* Don't allow mappings that would allow anything that wouldn't
 	 * be allowed without the establishment of unprivileged mappings.
 	 */
@@ -1253,7 +1312,7 @@
 	put_user_ns(to_user_ns(ns));
 }
 
-static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns)
+static int userns_install(struct nsset *nsset, struct ns_common *ns)
 {
 	struct user_namespace *user_ns = to_user_ns(ns);
 	struct cred *cred;
@@ -1274,14 +1333,14 @@
 	if (!ns_capable(user_ns, CAP_SYS_ADMIN))
 		return -EPERM;
 
-	cred = prepare_creds();
+	cred = nsset_cred(nsset);
 	if (!cred)
-		return -ENOMEM;
+		return -EINVAL;
 
 	put_user_ns(cred->user_ns);
 	set_cred_user_ns(cred, get_user_ns(user_ns));
 
-	return commit_creds(cred);
+	return 0;
 }
 
 struct ns_common *ns_get_owner(struct ns_common *ns)
diff --git a/kernel/usermode_driver.c b/kernel/usermode_driver.c
new file mode 100644
index 0000000..bb7bb3b
--- /dev/null
+++ b/kernel/usermode_driver.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * umd - User mode driver support
+ */
+#include <linux/shmem_fs.h>
+#include <linux/pipe_fs_i.h>
+#include <linux/mount.h>
+#include <linux/fs_struct.h>
+#include <linux/task_work.h>
+#include <linux/usermode_driver.h>
+
+static struct vfsmount *blob_to_mnt(const void *data, size_t len, const char *name)
+{
+	struct file_system_type *type;
+	struct vfsmount *mnt;
+	struct file *file;
+	ssize_t written;
+	loff_t pos = 0;
+
+	type = get_fs_type("tmpfs");
+	if (!type)
+		return ERR_PTR(-ENODEV);
+
+	mnt = kern_mount(type);
+	put_filesystem(type);
+	if (IS_ERR(mnt))
+		return mnt;
+
+	file = file_open_root(mnt->mnt_root, mnt, name, O_CREAT | O_WRONLY, 0700);
+	if (IS_ERR(file)) {
+		mntput(mnt);
+		return ERR_CAST(file);
+	}
+
+	written = kernel_write(file, data, len, &pos);
+	if (written != len) {
+		int err = written;
+		if (err >= 0)
+			err = -ENOMEM;
+		filp_close(file, NULL);
+		mntput(mnt);
+		return ERR_PTR(err);
+	}
+
+	fput(file);
+
+	/* Flush delayed fput so exec can open the file read-only */
+	flush_delayed_fput();
+	task_work_run();
+	return mnt;
+}
+
+/**
+ * umd_load_blob - Remember a blob of bytes for fork_usermode_driver
+ * @info: information about usermode driver
+ * @data: a blob of bytes that can be executed as a file
+ * @len:  The lentgh of the blob
+ *
+ */
+int umd_load_blob(struct umd_info *info, const void *data, size_t len)
+{
+	struct vfsmount *mnt;
+
+	if (WARN_ON_ONCE(info->wd.dentry || info->wd.mnt))
+		return -EBUSY;
+
+	mnt = blob_to_mnt(data, len, info->driver_name);
+	if (IS_ERR(mnt))
+		return PTR_ERR(mnt);
+
+	info->wd.mnt = mnt;
+	info->wd.dentry = mnt->mnt_root;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(umd_load_blob);
+
+/**
+ * umd_unload_blob - Disassociate @info from a previously loaded blob
+ * @info: information about usermode driver
+ *
+ */
+int umd_unload_blob(struct umd_info *info)
+{
+	if (WARN_ON_ONCE(!info->wd.mnt ||
+			 !info->wd.dentry ||
+			 info->wd.mnt->mnt_root != info->wd.dentry))
+		return -EINVAL;
+
+	kern_unmount(info->wd.mnt);
+	info->wd.mnt = NULL;
+	info->wd.dentry = NULL;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(umd_unload_blob);
+
+static int umd_setup(struct subprocess_info *info, struct cred *new)
+{
+	struct umd_info *umd_info = info->data;
+	struct file *from_umh[2];
+	struct file *to_umh[2];
+	int err;
+
+	/* create pipe to send data to umh */
+	err = create_pipe_files(to_umh, 0);
+	if (err)
+		return err;
+	err = replace_fd(0, to_umh[0], 0);
+	fput(to_umh[0]);
+	if (err < 0) {
+		fput(to_umh[1]);
+		return err;
+	}
+
+	/* create pipe to receive data from umh */
+	err = create_pipe_files(from_umh, 0);
+	if (err) {
+		fput(to_umh[1]);
+		replace_fd(0, NULL, 0);
+		return err;
+	}
+	err = replace_fd(1, from_umh[1], 0);
+	fput(from_umh[1]);
+	if (err < 0) {
+		fput(to_umh[1]);
+		replace_fd(0, NULL, 0);
+		fput(from_umh[0]);
+		return err;
+	}
+
+	set_fs_pwd(current->fs, &umd_info->wd);
+	umd_info->pipe_to_umh = to_umh[1];
+	umd_info->pipe_from_umh = from_umh[0];
+	umd_info->tgid = get_pid(task_tgid(current));
+	return 0;
+}
+
+static void umd_cleanup(struct subprocess_info *info)
+{
+	struct umd_info *umd_info = info->data;
+
+	/* cleanup if umh_setup() was successful but exec failed */
+	if (info->retval)
+		umd_cleanup_helper(umd_info);
+}
+
+/**
+ * umd_cleanup_helper - release the resources which were allocated in umd_setup
+ * @info: information about usermode driver
+ */
+void umd_cleanup_helper(struct umd_info *info)
+{
+	fput(info->pipe_to_umh);
+	fput(info->pipe_from_umh);
+	put_pid(info->tgid);
+	info->tgid = NULL;
+}
+EXPORT_SYMBOL_GPL(umd_cleanup_helper);
+
+/**
+ * fork_usermode_driver - fork a usermode driver
+ * @info: information about usermode driver (shouldn't be NULL)
+ *
+ * Returns either negative error or zero which indicates success in
+ * executing a usermode driver. In such case 'struct umd_info *info'
+ * is populated with two pipes and a tgid of the process. The caller is
+ * responsible for health check of the user process, killing it via
+ * tgid, and closing the pipes when user process is no longer needed.
+ */
+int fork_usermode_driver(struct umd_info *info)
+{
+	struct subprocess_info *sub_info;
+	const char *argv[] = { info->driver_name, NULL };
+	int err;
+
+	if (WARN_ON_ONCE(info->tgid))
+		return -EBUSY;
+
+	err = -ENOMEM;
+	sub_info = call_usermodehelper_setup(info->driver_name,
+					     (char **)argv, NULL, GFP_KERNEL,
+					     umd_setup, umd_cleanup, info);
+	if (!sub_info)
+		goto out;
+
+	err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(fork_usermode_driver);
+
+
diff --git a/kernel/utsname.c b/kernel/utsname.c
index f0e4911..e488d0e 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -140,12 +140,13 @@
 	put_uts_ns(to_uts_ns(ns));
 }
 
-static int utsns_install(struct nsproxy *nsproxy, struct ns_common *new)
+static int utsns_install(struct nsset *nsset, struct ns_common *new)
 {
+	struct nsproxy *nsproxy = nsset->nsproxy;
 	struct uts_namespace *ns = to_uts_ns(new);
 
 	if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
-	    !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
+	    !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
 		return -EPERM;
 
 	get_uts_ns(ns);
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 3732c88..4ca61d4 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -30,7 +30,7 @@
  *	to observe. Should this be in kernel/sys.c ????
  */
 static int proc_do_uts_string(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table uts_table;
 	int r;
diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
new file mode 100644
index 0000000..e3f144d
--- /dev/null
+++ b/kernel/watch_queue.c
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Watch queue and general notification mechanism, built on pipes
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * See Documentation/watch_queue.rst
+ */
+
+#define pr_fmt(fmt) "watchq: " fmt
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/printk.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/poll.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/file.h>
+#include <linux/security.h>
+#include <linux/cred.h>
+#include <linux/sched/signal.h>
+#include <linux/watch_queue.h>
+#include <linux/pipe_fs_i.h>
+
+MODULE_DESCRIPTION("Watch queue");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+
+#define WATCH_QUEUE_NOTE_SIZE 128
+#define WATCH_QUEUE_NOTES_PER_PAGE (PAGE_SIZE / WATCH_QUEUE_NOTE_SIZE)
+
+static void watch_queue_pipe_buf_release(struct pipe_inode_info *pipe,
+					 struct pipe_buffer *buf)
+{
+	struct watch_queue *wqueue = (struct watch_queue *)buf->private;
+	struct page *page;
+	unsigned int bit;
+
+	/* We need to work out which note within the page this refers to, but
+	 * the note might have been maximum size, so merely ANDing the offset
+	 * off doesn't work.  OTOH, the note must've been more than zero size.
+	 */
+	bit = buf->offset + buf->len;
+	if ((bit & (WATCH_QUEUE_NOTE_SIZE - 1)) == 0)
+		bit -= WATCH_QUEUE_NOTE_SIZE;
+	bit /= WATCH_QUEUE_NOTE_SIZE;
+
+	page = buf->page;
+	bit += page->index;
+
+	set_bit(bit, wqueue->notes_bitmap);
+	generic_pipe_buf_release(pipe, buf);
+}
+
+// No try_steal function => no stealing
+#define watch_queue_pipe_buf_try_steal NULL
+
+/* New data written to a pipe may be appended to a buffer with this type. */
+static const struct pipe_buf_operations watch_queue_pipe_buf_ops = {
+	.release	= watch_queue_pipe_buf_release,
+	.try_steal	= watch_queue_pipe_buf_try_steal,
+	.get		= generic_pipe_buf_get,
+};
+
+/*
+ * Post a notification to a watch queue.
+ */
+static bool post_one_notification(struct watch_queue *wqueue,
+				  struct watch_notification *n)
+{
+	void *p;
+	struct pipe_inode_info *pipe = wqueue->pipe;
+	struct pipe_buffer *buf;
+	struct page *page;
+	unsigned int head, tail, mask, note, offset, len;
+	bool done = false;
+
+	if (!pipe)
+		return false;
+
+	spin_lock_irq(&pipe->rd_wait.lock);
+
+	if (wqueue->defunct)
+		goto out;
+
+	mask = pipe->ring_size - 1;
+	head = pipe->head;
+	tail = pipe->tail;
+	if (pipe_full(head, tail, pipe->ring_size))
+		goto lost;
+
+	note = find_first_bit(wqueue->notes_bitmap, wqueue->nr_notes);
+	if (note >= wqueue->nr_notes)
+		goto lost;
+
+	page = wqueue->notes[note / WATCH_QUEUE_NOTES_PER_PAGE];
+	offset = note % WATCH_QUEUE_NOTES_PER_PAGE * WATCH_QUEUE_NOTE_SIZE;
+	get_page(page);
+	len = n->info & WATCH_INFO_LENGTH;
+	p = kmap_atomic(page);
+	memcpy(p + offset, n, len);
+	kunmap_atomic(p);
+
+	buf = &pipe->bufs[head & mask];
+	buf->page = page;
+	buf->private = (unsigned long)wqueue;
+	buf->ops = &watch_queue_pipe_buf_ops;
+	buf->offset = offset;
+	buf->len = len;
+	buf->flags = PIPE_BUF_FLAG_WHOLE;
+	smp_store_release(&pipe->head, head + 1); /* vs pipe_read() */
+
+	if (!test_and_clear_bit(note, wqueue->notes_bitmap)) {
+		spin_unlock_irq(&pipe->rd_wait.lock);
+		BUG();
+	}
+	wake_up_interruptible_sync_poll_locked(&pipe->rd_wait, EPOLLIN | EPOLLRDNORM);
+	done = true;
+
+out:
+	spin_unlock_irq(&pipe->rd_wait.lock);
+	if (done)
+		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
+	return done;
+
+lost:
+	buf = &pipe->bufs[(head - 1) & mask];
+	buf->flags |= PIPE_BUF_FLAG_LOSS;
+	goto out;
+}
+
+/*
+ * Apply filter rules to a notification.
+ */
+static bool filter_watch_notification(const struct watch_filter *wf,
+				      const struct watch_notification *n)
+{
+	const struct watch_type_filter *wt;
+	unsigned int st_bits = sizeof(wt->subtype_filter[0]) * 8;
+	unsigned int st_index = n->subtype / st_bits;
+	unsigned int st_bit = 1U << (n->subtype % st_bits);
+	int i;
+
+	if (!test_bit(n->type, wf->type_filter))
+		return false;
+
+	for (i = 0; i < wf->nr_filters; i++) {
+		wt = &wf->filters[i];
+		if (n->type == wt->type &&
+		    (wt->subtype_filter[st_index] & st_bit) &&
+		    (n->info & wt->info_mask) == wt->info_filter)
+			return true;
+	}
+
+	return false; /* If there is a filter, the default is to reject. */
+}
+
+/**
+ * __post_watch_notification - Post an event notification
+ * @wlist: The watch list to post the event to.
+ * @n: The notification record to post.
+ * @cred: The creds of the process that triggered the notification.
+ * @id: The ID to match on the watch.
+ *
+ * Post a notification of an event into a set of watch queues and let the users
+ * know.
+ *
+ * The size of the notification should be set in n->info & WATCH_INFO_LENGTH and
+ * should be in units of sizeof(*n).
+ */
+void __post_watch_notification(struct watch_list *wlist,
+			       struct watch_notification *n,
+			       const struct cred *cred,
+			       u64 id)
+{
+	const struct watch_filter *wf;
+	struct watch_queue *wqueue;
+	struct watch *watch;
+
+	if (((n->info & WATCH_INFO_LENGTH) >> WATCH_INFO_LENGTH__SHIFT) == 0) {
+		WARN_ON(1);
+		return;
+	}
+
+	rcu_read_lock();
+
+	hlist_for_each_entry_rcu(watch, &wlist->watchers, list_node) {
+		if (watch->id != id)
+			continue;
+		n->info &= ~WATCH_INFO_ID;
+		n->info |= watch->info_id;
+
+		wqueue = rcu_dereference(watch->queue);
+		wf = rcu_dereference(wqueue->filter);
+		if (wf && !filter_watch_notification(wf, n))
+			continue;
+
+		if (security_post_notification(watch->cred, cred, n) < 0)
+			continue;
+
+		post_one_notification(wqueue, n);
+	}
+
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(__post_watch_notification);
+
+/*
+ * Allocate sufficient pages to preallocation for the requested number of
+ * notifications.
+ */
+long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes)
+{
+	struct watch_queue *wqueue = pipe->watch_queue;
+	struct page **pages;
+	unsigned long *bitmap;
+	unsigned long user_bufs;
+	unsigned int bmsize;
+	int ret, i, nr_pages;
+
+	if (!wqueue)
+		return -ENODEV;
+	if (wqueue->notes)
+		return -EBUSY;
+
+	if (nr_notes < 1 ||
+	    nr_notes > 512) /* TODO: choose a better hard limit */
+		return -EINVAL;
+
+	nr_pages = (nr_notes + WATCH_QUEUE_NOTES_PER_PAGE - 1);
+	nr_pages /= WATCH_QUEUE_NOTES_PER_PAGE;
+	user_bufs = account_pipe_buffers(pipe->user, pipe->nr_accounted, nr_pages);
+
+	if (nr_pages > pipe->max_usage &&
+	    (too_many_pipe_buffers_hard(user_bufs) ||
+	     too_many_pipe_buffers_soft(user_bufs)) &&
+	    pipe_is_unprivileged_user()) {
+		ret = -EPERM;
+		goto error;
+	}
+
+	nr_notes = nr_pages * WATCH_QUEUE_NOTES_PER_PAGE;
+	ret = pipe_resize_ring(pipe, roundup_pow_of_two(nr_notes));
+	if (ret < 0)
+		goto error;
+
+	pages = kcalloc(sizeof(struct page *), nr_pages, GFP_KERNEL);
+	if (!pages)
+		goto error;
+
+	for (i = 0; i < nr_pages; i++) {
+		pages[i] = alloc_page(GFP_KERNEL);
+		if (!pages[i])
+			goto error_p;
+		pages[i]->index = i * WATCH_QUEUE_NOTES_PER_PAGE;
+	}
+
+	bmsize = (nr_notes + BITS_PER_LONG - 1) / BITS_PER_LONG;
+	bmsize *= sizeof(unsigned long);
+	bitmap = kmalloc(bmsize, GFP_KERNEL);
+	if (!bitmap)
+		goto error_p;
+
+	memset(bitmap, 0xff, bmsize);
+	wqueue->notes = pages;
+	wqueue->notes_bitmap = bitmap;
+	wqueue->nr_pages = nr_pages;
+	wqueue->nr_notes = nr_notes;
+	return 0;
+
+error_p:
+	for (i = 0; i < nr_pages; i++)
+		__free_page(pages[i]);
+	kfree(pages);
+error:
+	(void) account_pipe_buffers(pipe->user, nr_pages, pipe->nr_accounted);
+	return ret;
+}
+
+/*
+ * Set the filter on a watch queue.
+ */
+long watch_queue_set_filter(struct pipe_inode_info *pipe,
+			    struct watch_notification_filter __user *_filter)
+{
+	struct watch_notification_type_filter *tf;
+	struct watch_notification_filter filter;
+	struct watch_type_filter *q;
+	struct watch_filter *wfilter;
+	struct watch_queue *wqueue = pipe->watch_queue;
+	int ret, nr_filter = 0, i;
+
+	if (!wqueue)
+		return -ENODEV;
+
+	if (!_filter) {
+		/* Remove the old filter */
+		wfilter = NULL;
+		goto set;
+	}
+
+	/* Grab the user's filter specification */
+	if (copy_from_user(&filter, _filter, sizeof(filter)) != 0)
+		return -EFAULT;
+	if (filter.nr_filters == 0 ||
+	    filter.nr_filters > 16 ||
+	    filter.__reserved != 0)
+		return -EINVAL;
+
+	tf = memdup_user(_filter->filters, filter.nr_filters * sizeof(*tf));
+	if (IS_ERR(tf))
+		return PTR_ERR(tf);
+
+	ret = -EINVAL;
+	for (i = 0; i < filter.nr_filters; i++) {
+		if ((tf[i].info_filter & ~tf[i].info_mask) ||
+		    tf[i].info_mask & WATCH_INFO_LENGTH)
+			goto err_filter;
+		/* Ignore any unknown types */
+		if (tf[i].type >= WATCH_TYPE__NR)
+			continue;
+		nr_filter++;
+	}
+
+	/* Now we need to build the internal filter from only the relevant
+	 * user-specified filters.
+	 */
+	ret = -ENOMEM;
+	wfilter = kzalloc(struct_size(wfilter, filters, nr_filter), GFP_KERNEL);
+	if (!wfilter)
+		goto err_filter;
+	wfilter->nr_filters = nr_filter;
+
+	q = wfilter->filters;
+	for (i = 0; i < filter.nr_filters; i++) {
+		if (tf[i].type >= WATCH_TYPE__NR)
+			continue;
+
+		q->type			= tf[i].type;
+		q->info_filter		= tf[i].info_filter;
+		q->info_mask		= tf[i].info_mask;
+		q->subtype_filter[0]	= tf[i].subtype_filter[0];
+		__set_bit(q->type, wfilter->type_filter);
+		q++;
+	}
+
+	kfree(tf);
+set:
+	pipe_lock(pipe);
+	wfilter = rcu_replace_pointer(wqueue->filter, wfilter,
+				      lockdep_is_held(&pipe->mutex));
+	pipe_unlock(pipe);
+	if (wfilter)
+		kfree_rcu(wfilter, rcu);
+	return 0;
+
+err_filter:
+	kfree(tf);
+	return ret;
+}
+
+static void __put_watch_queue(struct kref *kref)
+{
+	struct watch_queue *wqueue =
+		container_of(kref, struct watch_queue, usage);
+	struct watch_filter *wfilter;
+	int i;
+
+	for (i = 0; i < wqueue->nr_pages; i++)
+		__free_page(wqueue->notes[i]);
+	bitmap_free(wqueue->notes_bitmap);
+
+	wfilter = rcu_access_pointer(wqueue->filter);
+	if (wfilter)
+		kfree_rcu(wfilter, rcu);
+	kfree_rcu(wqueue, rcu);
+}
+
+/**
+ * put_watch_queue - Dispose of a ref on a watchqueue.
+ * @wqueue: The watch queue to unref.
+ */
+void put_watch_queue(struct watch_queue *wqueue)
+{
+	kref_put(&wqueue->usage, __put_watch_queue);
+}
+EXPORT_SYMBOL(put_watch_queue);
+
+static void free_watch(struct rcu_head *rcu)
+{
+	struct watch *watch = container_of(rcu, struct watch, rcu);
+
+	put_watch_queue(rcu_access_pointer(watch->queue));
+	atomic_dec(&watch->cred->user->nr_watches);
+	put_cred(watch->cred);
+}
+
+static void __put_watch(struct kref *kref)
+{
+	struct watch *watch = container_of(kref, struct watch, usage);
+
+	call_rcu(&watch->rcu, free_watch);
+}
+
+/*
+ * Discard a watch.
+ */
+static void put_watch(struct watch *watch)
+{
+	kref_put(&watch->usage, __put_watch);
+}
+
+/**
+ * init_watch_queue - Initialise a watch
+ * @watch: The watch to initialise.
+ * @wqueue: The queue to assign.
+ *
+ * Initialise a watch and set the watch queue.
+ */
+void init_watch(struct watch *watch, struct watch_queue *wqueue)
+{
+	kref_init(&watch->usage);
+	INIT_HLIST_NODE(&watch->list_node);
+	INIT_HLIST_NODE(&watch->queue_node);
+	rcu_assign_pointer(watch->queue, wqueue);
+}
+
+/**
+ * add_watch_to_object - Add a watch on an object to a watch list
+ * @watch: The watch to add
+ * @wlist: The watch list to add to
+ *
+ * @watch->queue must have been set to point to the queue to post notifications
+ * to and the watch list of the object to be watched.  @watch->cred must also
+ * have been set to the appropriate credentials and a ref taken on them.
+ *
+ * The caller must pin the queue and the list both and must hold the list
+ * locked against racing watch additions/removals.
+ */
+int add_watch_to_object(struct watch *watch, struct watch_list *wlist)
+{
+	struct watch_queue *wqueue = rcu_access_pointer(watch->queue);
+	struct watch *w;
+
+	hlist_for_each_entry(w, &wlist->watchers, list_node) {
+		struct watch_queue *wq = rcu_access_pointer(w->queue);
+		if (wqueue == wq && watch->id == w->id)
+			return -EBUSY;
+	}
+
+	watch->cred = get_current_cred();
+	rcu_assign_pointer(watch->watch_list, wlist);
+
+	if (atomic_inc_return(&watch->cred->user->nr_watches) >
+	    task_rlimit(current, RLIMIT_NOFILE)) {
+		atomic_dec(&watch->cred->user->nr_watches);
+		put_cred(watch->cred);
+		return -EAGAIN;
+	}
+
+	spin_lock_bh(&wqueue->lock);
+	kref_get(&wqueue->usage);
+	kref_get(&watch->usage);
+	hlist_add_head(&watch->queue_node, &wqueue->watches);
+	spin_unlock_bh(&wqueue->lock);
+
+	hlist_add_head(&watch->list_node, &wlist->watchers);
+	return 0;
+}
+EXPORT_SYMBOL(add_watch_to_object);
+
+/**
+ * remove_watch_from_object - Remove a watch or all watches from an object.
+ * @wlist: The watch list to remove from
+ * @wq: The watch queue of interest (ignored if @all is true)
+ * @id: The ID of the watch to remove (ignored if @all is true)
+ * @all: True to remove all objects
+ *
+ * Remove a specific watch or all watches from an object.  A notification is
+ * sent to the watcher to tell them that this happened.
+ */
+int remove_watch_from_object(struct watch_list *wlist, struct watch_queue *wq,
+			     u64 id, bool all)
+{
+	struct watch_notification_removal n;
+	struct watch_queue *wqueue;
+	struct watch *watch;
+	int ret = -EBADSLT;
+
+	rcu_read_lock();
+
+again:
+	spin_lock(&wlist->lock);
+	hlist_for_each_entry(watch, &wlist->watchers, list_node) {
+		if (all ||
+		    (watch->id == id && rcu_access_pointer(watch->queue) == wq))
+			goto found;
+	}
+	spin_unlock(&wlist->lock);
+	goto out;
+
+found:
+	ret = 0;
+	hlist_del_init_rcu(&watch->list_node);
+	rcu_assign_pointer(watch->watch_list, NULL);
+	spin_unlock(&wlist->lock);
+
+	/* We now own the reference on watch that used to belong to wlist. */
+
+	n.watch.type = WATCH_TYPE_META;
+	n.watch.subtype = WATCH_META_REMOVAL_NOTIFICATION;
+	n.watch.info = watch->info_id | watch_sizeof(n.watch);
+	n.id = id;
+	if (id != 0)
+		n.watch.info = watch->info_id | watch_sizeof(n);
+
+	wqueue = rcu_dereference(watch->queue);
+
+	/* We don't need the watch list lock for the next bit as RCU is
+	 * protecting *wqueue from deallocation.
+	 */
+	if (wqueue) {
+		post_one_notification(wqueue, &n.watch);
+
+		spin_lock_bh(&wqueue->lock);
+
+		if (!hlist_unhashed(&watch->queue_node)) {
+			hlist_del_init_rcu(&watch->queue_node);
+			put_watch(watch);
+		}
+
+		spin_unlock_bh(&wqueue->lock);
+	}
+
+	if (wlist->release_watch) {
+		void (*release_watch)(struct watch *);
+
+		release_watch = wlist->release_watch;
+		rcu_read_unlock();
+		(*release_watch)(watch);
+		rcu_read_lock();
+	}
+	put_watch(watch);
+
+	if (all && !hlist_empty(&wlist->watchers))
+		goto again;
+out:
+	rcu_read_unlock();
+	return ret;
+}
+EXPORT_SYMBOL(remove_watch_from_object);
+
+/*
+ * Remove all the watches that are contributory to a queue.  This has the
+ * potential to race with removal of the watches by the destruction of the
+ * objects being watched or with the distribution of notifications.
+ */
+void watch_queue_clear(struct watch_queue *wqueue)
+{
+	struct watch_list *wlist;
+	struct watch *watch;
+	bool release;
+
+	rcu_read_lock();
+	spin_lock_bh(&wqueue->lock);
+
+	/* Prevent new notifications from being stored. */
+	wqueue->defunct = true;
+
+	while (!hlist_empty(&wqueue->watches)) {
+		watch = hlist_entry(wqueue->watches.first, struct watch, queue_node);
+		hlist_del_init_rcu(&watch->queue_node);
+		/* We now own a ref on the watch. */
+		spin_unlock_bh(&wqueue->lock);
+
+		/* We can't do the next bit under the queue lock as we need to
+		 * get the list lock - which would cause a deadlock if someone
+		 * was removing from the opposite direction at the same time or
+		 * posting a notification.
+		 */
+		wlist = rcu_dereference(watch->watch_list);
+		if (wlist) {
+			void (*release_watch)(struct watch *);
+
+			spin_lock(&wlist->lock);
+
+			release = !hlist_unhashed(&watch->list_node);
+			if (release) {
+				hlist_del_init_rcu(&watch->list_node);
+				rcu_assign_pointer(watch->watch_list, NULL);
+
+				/* We now own a second ref on the watch. */
+			}
+
+			release_watch = wlist->release_watch;
+			spin_unlock(&wlist->lock);
+
+			if (release) {
+				if (release_watch) {
+					rcu_read_unlock();
+					/* This might need to call dput(), so
+					 * we have to drop all the locks.
+					 */
+					(*release_watch)(watch);
+					rcu_read_lock();
+				}
+				put_watch(watch);
+			}
+		}
+
+		put_watch(watch);
+		spin_lock_bh(&wqueue->lock);
+	}
+
+	spin_unlock_bh(&wqueue->lock);
+	rcu_read_unlock();
+}
+
+/**
+ * get_watch_queue - Get a watch queue from its file descriptor.
+ * @fd: The fd to query.
+ */
+struct watch_queue *get_watch_queue(int fd)
+{
+	struct pipe_inode_info *pipe;
+	struct watch_queue *wqueue = ERR_PTR(-EINVAL);
+	struct fd f;
+
+	f = fdget(fd);
+	if (f.file) {
+		pipe = get_pipe_info(f.file, false);
+		if (pipe && pipe->watch_queue) {
+			wqueue = pipe->watch_queue;
+			kref_get(&wqueue->usage);
+		}
+		fdput(f);
+	}
+
+	return wqueue;
+}
+EXPORT_SYMBOL(get_watch_queue);
+
+/*
+ * Initialise a watch queue
+ */
+int watch_queue_init(struct pipe_inode_info *pipe)
+{
+	struct watch_queue *wqueue;
+
+	wqueue = kzalloc(sizeof(*wqueue), GFP_KERNEL);
+	if (!wqueue)
+		return -ENOMEM;
+
+	wqueue->pipe = pipe;
+	kref_init(&wqueue->usage);
+	spin_lock_init(&wqueue->lock);
+	INIT_HLIST_HEAD(&wqueue->watches);
+
+	pipe->watch_queue = wqueue;
+	return 0;
+}
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index cbd3cf5..01bf977 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -44,12 +44,15 @@
 int __read_mostly watchdog_thresh = 10;
 static int __read_mostly nmi_watchdog_available;
 
-static struct cpumask watchdog_allowed_mask __read_mostly;
-
 struct cpumask watchdog_cpumask __read_mostly;
 unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
+
+# ifdef CONFIG_SMP
+int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
+# endif /* CONFIG_SMP */
+
 /*
  * Should we panic when a soft-lockup or hard-lockup occurs:
  */
@@ -82,16 +85,6 @@
 }
 __setup("nmi_watchdog=", hardlockup_panic_setup);
 
-# ifdef CONFIG_SMP
-int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
-
-static int __init hardlockup_all_cpu_backtrace_setup(char *str)
-{
-	sysctl_hardlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0);
-	return 1;
-}
-__setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup);
-# endif /* CONFIG_SMP */
 #endif /* CONFIG_HARDLOCKUP_DETECTOR */
 
 /*
@@ -163,6 +156,12 @@
 
 #define SOFTLOCKUP_RESET	ULONG_MAX
 
+#ifdef CONFIG_SMP
+int __read_mostly sysctl_softlockup_all_cpu_backtrace;
+#endif
+
+static struct cpumask watchdog_allowed_mask __read_mostly;
+
 /* Global variables, exported for sysctl */
 unsigned int __read_mostly softlockup_panic =
 			CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
@@ -173,20 +172,10 @@
 static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
 static DEFINE_PER_CPU(struct hrtimer, watchdog_hrtimer);
 static DEFINE_PER_CPU(bool, softlockup_touch_sync);
-static DEFINE_PER_CPU(bool, soft_watchdog_warn);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
-static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
-static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
 static unsigned long soft_lockup_nmi_warn;
 
-static int __init softlockup_panic_setup(char *str)
-{
-	softlockup_panic = simple_strtoul(str, NULL, 0);
-	return 1;
-}
-__setup("softlockup_panic=", softlockup_panic_setup);
-
 static int __init nowatchdog_setup(char *str)
 {
 	watchdog_user_enabled = 0;
@@ -208,17 +197,6 @@
 }
 __setup("watchdog_thresh=", watchdog_thresh_setup);
 
-#ifdef CONFIG_SMP
-int __read_mostly sysctl_softlockup_all_cpu_backtrace;
-
-static int __init softlockup_all_cpu_backtrace_setup(char *str)
-{
-	sysctl_softlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0);
-	return 1;
-}
-__setup("softlockup_all_cpu_backtrace=", softlockup_all_cpu_backtrace_setup);
-#endif
-
 static void __lockup_detector_cleanup(void);
 
 /*
@@ -257,7 +235,7 @@
 }
 
 /* Commands for resetting the watchdog */
-static void __touch_watchdog(void)
+static void update_touch_ts(void)
 {
 	__this_cpu_write(watchdog_touch_ts, get_timestamp());
 }
@@ -352,9 +330,7 @@
  */
 static int softlockup_fn(void *data)
 {
-	__this_cpu_write(soft_lockup_hrtimer_cnt,
-			 __this_cpu_read(hrtimer_interrupts));
-	__touch_watchdog();
+	update_touch_ts();
 	complete(this_cpu_ptr(&softlockup_completion));
 
 	return 0;
@@ -397,7 +373,7 @@
 
 		/* Clear the guest paused flag on watchdog reset */
 		kvm_check_and_clear_guest_paused();
-		__touch_watchdog();
+		update_touch_ts();
 		return HRTIMER_RESTART;
 	}
 
@@ -417,39 +393,21 @@
 		if (kvm_check_and_clear_guest_paused())
 			return HRTIMER_RESTART;
 
-		/* only warn once */
-		if (__this_cpu_read(soft_watchdog_warn) == true) {
-			/*
-			 * When multiple processes are causing softlockups the
-			 * softlockup detector only warns on the first one
-			 * because the code relies on a full quiet cycle to
-			 * re-arm.  The second process prevents the quiet cycle
-			 * and never gets reported.  Use task pointers to detect
-			 * this.
-			 */
-			if (__this_cpu_read(softlockup_task_ptr_saved) !=
-			    current) {
-				__this_cpu_write(soft_watchdog_warn, false);
-				__touch_watchdog();
-			}
-			return HRTIMER_RESTART;
+		/*
+		 * Prevent multiple soft-lockup reports if one cpu is already
+		 * engaged in dumping all cpu back traces.
+		 */
+		if (softlockup_all_cpu_backtrace) {
+			if (test_and_set_bit_lock(0, &soft_lockup_nmi_warn))
+				return HRTIMER_RESTART;
 		}
 
-		if (softlockup_all_cpu_backtrace) {
-			/* Prevent multiple soft-lockup reports if one cpu is already
-			 * engaged in dumping cpu back traces
-			 */
-			if (test_and_set_bit(0, &soft_lockup_nmi_warn)) {
-				/* Someone else will report us. Let's give up */
-				__this_cpu_write(soft_watchdog_warn, true);
-				return HRTIMER_RESTART;
-			}
-		}
+		/* Start period for the next softlockup warning. */
+		update_touch_ts();
 
 		pr_emerg("BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
 			smp_processor_id(), duration,
 			current->comm, task_pid_nr(current));
-		__this_cpu_write(softlockup_task_ptr_saved, current);
 		print_modules();
 		print_irqtrace_events(current);
 		if (regs)
@@ -458,22 +416,14 @@
 			dump_stack();
 
 		if (softlockup_all_cpu_backtrace) {
-			/* Avoid generating two back traces for current
-			 * given that one is already made above
-			 */
 			trigger_allbutself_cpu_backtrace();
-
-			clear_bit(0, &soft_lockup_nmi_warn);
-			/* Barrier to sync with other cpus */
-			smp_mb__after_atomic();
+			clear_bit_unlock(0, &soft_lockup_nmi_warn);
 		}
 
 		add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
 		if (softlockup_panic)
 			panic("softlockup: hung tasks");
-		__this_cpu_write(soft_watchdog_warn, true);
-	} else
-		__this_cpu_write(soft_watchdog_warn, false);
+	}
 
 	return HRTIMER_RESTART;
 }
@@ -498,7 +448,7 @@
 		      HRTIMER_MODE_REL_PINNED_HARD);
 
 	/* Initialize timestamp */
-	__touch_watchdog();
+	update_touch_ts();
 	/* Enable the perf event */
 	if (watchdog_enabled & NMI_WATCHDOG_ENABLED)
 		watchdog_nmi_enable(cpu);
@@ -680,7 +630,7 @@
  * proc_soft_watchdog | soft_watchdog_user_enabled | SOFT_WATCHDOG_ENABLED
  */
 static int proc_watchdog_common(int which, struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int err, old, *param = table->data;
 
@@ -707,7 +657,7 @@
  * /proc/sys/kernel/watchdog
  */
 int proc_watchdog(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return proc_watchdog_common(NMI_WATCHDOG_ENABLED|SOFT_WATCHDOG_ENABLED,
 				    table, write, buffer, lenp, ppos);
@@ -717,7 +667,7 @@
  * /proc/sys/kernel/nmi_watchdog
  */
 int proc_nmi_watchdog(struct ctl_table *table, int write,
-		      void __user *buffer, size_t *lenp, loff_t *ppos)
+		      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!nmi_watchdog_available && write)
 		return -ENOTSUPP;
@@ -729,7 +679,7 @@
  * /proc/sys/kernel/soft_watchdog
  */
 int proc_soft_watchdog(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+			void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return proc_watchdog_common(SOFT_WATCHDOG_ENABLED,
 				    table, write, buffer, lenp, ppos);
@@ -739,7 +689,7 @@
  * /proc/sys/kernel/watchdog_thresh
  */
 int proc_watchdog_thresh(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int err, old;
 
@@ -762,7 +712,7 @@
  * been brought online, if desired.
  */
 int proc_watchdog_cpumask(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int err;
 
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 885d479..fdf5fa4 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -146,7 +146,7 @@
 /* struct worker is defined in workqueue_internal.h */
 
 struct worker_pool {
-	spinlock_t		lock;		/* the pool lock */
+	raw_spinlock_t		lock;		/* the pool lock */
 	int			cpu;		/* I: the associated cpu */
 	int			node;		/* I: the associated node ID */
 	int			id;		/* I: pool ID */
@@ -249,7 +249,7 @@
 	struct list_head	flusher_overflow; /* WQ: flush overflow list */
 
 	struct list_head	maydays;	/* MD: pwqs requesting rescue */
-	struct worker		*rescuer;	/* I: rescue worker */
+	struct worker		*rescuer;	/* MD: rescue worker */
 
 	int			nr_drainers;	/* WQ: drain in progress */
 	int			saved_max_active; /* WQ: saved pwq max_active */
@@ -301,8 +301,9 @@
 
 static DEFINE_MUTEX(wq_pool_mutex);	/* protects pools and workqueues list */
 static DEFINE_MUTEX(wq_pool_attach_mutex); /* protects worker attach/detach */
-static DEFINE_SPINLOCK(wq_mayday_lock);	/* protects wq->maydays list */
-static DECLARE_WAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */
+static DEFINE_RAW_SPINLOCK(wq_mayday_lock);	/* protects wq->maydays list */
+/* wait for manager to go away */
+static struct rcuwait manager_wait = __RCUWAIT_INITIALIZER(manager_wait);
 
 static LIST_HEAD(workqueues);		/* PR: list of all workqueues */
 static bool workqueue_freezing;		/* PL: have wqs started freezing? */
@@ -356,6 +357,7 @@
 
 static int worker_thread(void *__worker);
 static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
+static void show_pwq(struct pool_workqueue *pwq);
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/workqueue.h>
@@ -365,11 +367,6 @@
 			 !lockdep_is_held(&wq_pool_mutex),		\
 			 "RCU or wq_pool_mutex should be held")
 
-#define assert_rcu_or_wq_mutex(wq)					\
-	RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&			\
-			 !lockdep_is_held(&wq->mutex),			\
-			 "RCU or wq->mutex should be held")
-
 #define assert_rcu_or_wq_mutex_or_pool_mutex(wq)			\
 	RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&			\
 			 !lockdep_is_held(&wq->mutex) &&		\
@@ -427,13 +424,11 @@
  */
 #define for_each_pwq(pwq, wq)						\
 	list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node,		\
-				lockdep_is_held(&wq->mutex))		\
-		if (({ assert_rcu_or_wq_mutex(wq); false; })) { }	\
-		else
+				 lockdep_is_held(&(wq->mutex)))
 
 #ifdef CONFIG_DEBUG_OBJECTS_WORK
 
-static struct debug_obj_descr work_debug_descr;
+static const struct debug_obj_descr work_debug_descr;
 
 static void *work_debug_hint(void *addr)
 {
@@ -483,7 +478,7 @@
 	}
 }
 
-static struct debug_obj_descr work_debug_descr = {
+static const struct debug_obj_descr work_debug_descr = {
 	.name		= "work_struct",
 	.debug_hint	= work_debug_hint,
 	.is_static_object = work_is_static_object,
@@ -833,7 +828,7 @@
  * Wake up the first idle worker of @pool.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void wake_up_worker(struct worker_pool *pool)
 {
@@ -855,8 +850,17 @@
 
 	if (!worker->sleeping)
 		return;
+
+	/*
+	 * If preempted by unbind_workers() between the WORKER_NOT_RUNNING check
+	 * and the nr_running increment below, we may ruin the nr_running reset
+	 * and leave with an unexpected pool->nr_running == 1 on the newly unbound
+	 * pool. Protect against such race.
+	 */
+	preempt_disable();
 	if (!(worker->flags & WORKER_NOT_RUNNING))
 		atomic_inc(&worker->pool->nr_running);
+	preempt_enable();
 	worker->sleeping = 0;
 }
 
@@ -888,7 +892,7 @@
 		return;
 
 	worker->sleeping = 1;
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	/*
 	 * The counterpart of the following dec_and_test, implied mb,
@@ -907,7 +911,7 @@
 		if (next)
 			wake_up_process(next->task);
 	}
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 }
 
 /**
@@ -918,7 +922,7 @@
  * the scheduler to get a worker's last known identity.
  *
  * CONTEXT:
- * spin_lock_irq(rq->lock)
+ * raw_spin_lock_irq(rq->lock)
  *
  * This function is called during schedule() when a kworker is going
  * to sleep. It's used by psi to identify aggregation workers during
@@ -949,7 +953,7 @@
  * Set @flags in @worker->flags and adjust nr_running accordingly.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock)
+ * raw_spin_lock_irq(pool->lock)
  */
 static inline void worker_set_flags(struct worker *worker, unsigned int flags)
 {
@@ -974,7 +978,7 @@
  * Clear @flags in @worker->flags and adjust nr_running accordingly.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock)
+ * raw_spin_lock_irq(pool->lock)
  */
 static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
 {
@@ -1022,7 +1026,7 @@
  * actually occurs, it should be easy to locate the culprit work function.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  *
  * Return:
  * Pointer to worker which is executing @work if found, %NULL
@@ -1057,7 +1061,7 @@
  * nested inside outer list_for_each_entry_safe().
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void move_linked_works(struct work_struct *work, struct list_head *head,
 			      struct work_struct **nextp)
@@ -1135,9 +1139,9 @@
 		 * As both pwqs and pools are RCU protected, the
 		 * following lock operations are safe.
 		 */
-		spin_lock_irq(&pwq->pool->lock);
+		raw_spin_lock_irq(&pwq->pool->lock);
 		put_pwq(pwq);
-		spin_unlock_irq(&pwq->pool->lock);
+		raw_spin_unlock_irq(&pwq->pool->lock);
 	}
 }
 
@@ -1170,7 +1174,7 @@
  * decrement nr_in_flight of its pwq and handle workqueue flushing.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, int color)
 {
@@ -1218,11 +1222,14 @@
  * stable state - idle, on timer or on worklist.
  *
  * Return:
+ *
+ *  ========	================================================================
  *  1		if @work was pending and we successfully stole PENDING
  *  0		if @work was idle and we claimed PENDING
  *  -EAGAIN	if PENDING couldn't be grabbed at the moment, safe to busy-retry
  *  -ENOENT	if someone else is canceling @work, this state may persist
  *		for arbitrarily long
+ *  ========	================================================================
  *
  * Note:
  * On >= 0 return, the caller owns @work's PENDING bit.  To avoid getting
@@ -1269,7 +1276,7 @@
 	if (!pool)
 		goto fail;
 
-	spin_lock(&pool->lock);
+	raw_spin_lock(&pool->lock);
 	/*
 	 * work->data is guaranteed to point to pwq only while the work
 	 * item is queued on pwq->wq, and both updating work->data to point
@@ -1298,11 +1305,11 @@
 		/* work->data points to pwq iff queued, point to pool */
 		set_work_pool_and_keep_pending(work, pool->id);
 
-		spin_unlock(&pool->lock);
+		raw_spin_unlock(&pool->lock);
 		rcu_read_unlock();
 		return 1;
 	}
-	spin_unlock(&pool->lock);
+	raw_spin_unlock(&pool->lock);
 fail:
 	rcu_read_unlock();
 	local_irq_restore(*flags);
@@ -1323,7 +1330,7 @@
  * work_struct flags.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void insert_work(struct pool_workqueue *pwq, struct work_struct *work,
 			struct list_head *head, unsigned int extra_flags)
@@ -1439,7 +1446,7 @@
 	if (last_pool && last_pool != pwq->pool) {
 		struct worker *worker;
 
-		spin_lock(&last_pool->lock);
+		raw_spin_lock(&last_pool->lock);
 
 		worker = find_worker_executing_work(last_pool, work);
 
@@ -1447,11 +1454,11 @@
 			pwq = worker->current_pwq;
 		} else {
 			/* meh... not running there, queue here */
-			spin_unlock(&last_pool->lock);
-			spin_lock(&pwq->pool->lock);
+			raw_spin_unlock(&last_pool->lock);
+			raw_spin_lock(&pwq->pool->lock);
 		}
 	} else {
-		spin_lock(&pwq->pool->lock);
+		raw_spin_lock(&pwq->pool->lock);
 	}
 
 	/*
@@ -1464,7 +1471,7 @@
 	 */
 	if (unlikely(!pwq->refcnt)) {
 		if (wq->flags & WQ_UNBOUND) {
-			spin_unlock(&pwq->pool->lock);
+			raw_spin_unlock(&pwq->pool->lock);
 			cpu_relax();
 			goto retry;
 		}
@@ -1497,7 +1504,7 @@
 	insert_work(pwq, work, worklist, work_flags);
 
 out:
-	spin_unlock(&pwq->pool->lock);
+	raw_spin_unlock(&pwq->pool->lock);
 	rcu_read_unlock();
 }
 
@@ -1766,7 +1773,7 @@
  * necessary.
  *
  * LOCKING:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void worker_enter_idle(struct worker *worker)
 {
@@ -1806,7 +1813,7 @@
  * @worker is leaving idle state.  Update stats.
  *
  * LOCKING:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void worker_leave_idle(struct worker *worker)
 {
@@ -1941,11 +1948,11 @@
 	worker_attach_to_pool(worker, pool);
 
 	/* start the newly created worker */
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 	worker->pool->nr_workers++;
 	worker_enter_idle(worker);
 	wake_up_process(worker->task);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	return worker;
 
@@ -1964,7 +1971,7 @@
  * be idle.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void destroy_worker(struct worker *worker)
 {
@@ -1990,7 +1997,7 @@
 {
 	struct worker_pool *pool = from_timer(pool, t, idle_timer);
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	while (too_many_workers(pool)) {
 		struct worker *worker;
@@ -2008,7 +2015,7 @@
 		destroy_worker(worker);
 	}
 
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 }
 
 static void send_mayday(struct work_struct *work)
@@ -2039,8 +2046,8 @@
 	struct worker_pool *pool = from_timer(pool, t, mayday_timer);
 	struct work_struct *work;
 
-	spin_lock_irq(&pool->lock);
-	spin_lock(&wq_mayday_lock);		/* for wq->maydays */
+	raw_spin_lock_irq(&pool->lock);
+	raw_spin_lock(&wq_mayday_lock);		/* for wq->maydays */
 
 	if (need_to_create_worker(pool)) {
 		/*
@@ -2053,8 +2060,8 @@
 			send_mayday(work);
 	}
 
-	spin_unlock(&wq_mayday_lock);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock(&wq_mayday_lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL);
 }
@@ -2073,7 +2080,7 @@
  * may_start_working() %true.
  *
  * LOCKING:
- * spin_lock_irq(pool->lock) which may be released and regrabbed
+ * raw_spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.  Does GFP_KERNEL allocations.  Called only from
  * manager.
  */
@@ -2082,7 +2089,7 @@
 __acquires(&pool->lock)
 {
 restart:
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	/* if we don't make progress in MAYDAY_INITIAL_TIMEOUT, call for help */
 	mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT);
@@ -2098,7 +2105,7 @@
 	}
 
 	del_timer_sync(&pool->mayday_timer);
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 	/*
 	 * This is necessary even after a new worker was just successfully
 	 * created as @pool->lock was dropped and the new worker might have
@@ -2121,7 +2128,7 @@
  * and may_start_working() is true.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock) which may be released and regrabbed
+ * raw_spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.  Does GFP_KERNEL allocations.
  *
  * Return:
@@ -2144,7 +2151,7 @@
 
 	pool->manager = NULL;
 	pool->flags &= ~POOL_MANAGER_ACTIVE;
-	wake_up(&wq_manager_wait);
+	rcuwait_wake_up(&manager_wait);
 	return true;
 }
 
@@ -2160,7 +2167,7 @@
  * call this function to process a work.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock) which is released and regrabbed.
+ * raw_spin_lock_irq(pool->lock) which is released and regrabbed.
  */
 static void process_one_work(struct worker *worker, struct work_struct *work)
 __releases(&pool->lock)
@@ -2242,7 +2249,7 @@
 	 */
 	set_work_pool_and_clear_pending(work, pool->id);
 
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	lock_map_acquire(&pwq->wq->lockdep_map);
 	lock_map_acquire(&lockdep_map);
@@ -2274,7 +2281,7 @@
 	 * While we must be careful to not use "work" after this, the trace
 	 * point will only record its address.
 	 */
-	trace_workqueue_execute_end(work);
+	trace_workqueue_execute_end(work, worker->current_func);
 	lock_map_release(&lockdep_map);
 	lock_map_release(&pwq->wq->lockdep_map);
 
@@ -2288,7 +2295,7 @@
 	}
 
 	/*
-	 * The following prevents a kworker from hogging CPU on !PREEMPT
+	 * The following prevents a kworker from hogging CPU on !PREEMPTION
 	 * kernels, where a requeueing work item waiting for something to
 	 * happen could deadlock with stop_machine as such work item could
 	 * indefinitely requeue itself while all other CPUs are trapped in
@@ -2297,7 +2304,7 @@
 	 */
 	cond_resched();
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	/* clear cpu intensive status */
 	if (unlikely(cpu_intensive))
@@ -2323,7 +2330,7 @@
  * fetches a work from the top and executes it.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock) which may be released and regrabbed
+ * raw_spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.
  */
 static void process_scheduled_works(struct worker *worker)
@@ -2365,11 +2372,11 @@
 	/* tell the scheduler that this is a workqueue worker */
 	set_pf_worker(true);
 woke_up:
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	/* am I supposed to die? */
 	if (unlikely(worker->flags & WORKER_DIE)) {
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 		WARN_ON_ONCE(!list_empty(&worker->entry));
 		set_pf_worker(false);
 
@@ -2435,7 +2442,7 @@
 	 */
 	worker_enter_idle(worker);
 	__set_current_state(TASK_IDLE);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 	schedule();
 	goto woke_up;
 }
@@ -2489,7 +2496,7 @@
 	should_stop = kthread_should_stop();
 
 	/* see whether any pwq is asking for help */
-	spin_lock_irq(&wq_mayday_lock);
+	raw_spin_lock_irq(&wq_mayday_lock);
 
 	while (!list_empty(&wq->maydays)) {
 		struct pool_workqueue *pwq = list_first_entry(&wq->maydays,
@@ -2501,11 +2508,11 @@
 		__set_current_state(TASK_RUNNING);
 		list_del_init(&pwq->mayday_node);
 
-		spin_unlock_irq(&wq_mayday_lock);
+		raw_spin_unlock_irq(&wq_mayday_lock);
 
 		worker_attach_to_pool(rescuer, pool);
 
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 
 		/*
 		 * Slurp in all works issued via this workqueue and
@@ -2533,8 +2540,8 @@
 			 * being used to relieve memory pressure, don't
 			 * incur MAYDAY_INTERVAL delay inbetween.
 			 */
-			if (need_to_create_worker(pool)) {
-				spin_lock(&wq_mayday_lock);
+			if (pwq->nr_active && need_to_create_worker(pool)) {
+				raw_spin_lock(&wq_mayday_lock);
 				/*
 				 * Queue iff we aren't racing destruction
 				 * and somebody else hasn't queued it already.
@@ -2543,7 +2550,7 @@
 					get_pwq(pwq);
 					list_add_tail(&pwq->mayday_node, &wq->maydays);
 				}
-				spin_unlock(&wq_mayday_lock);
+				raw_spin_unlock(&wq_mayday_lock);
 			}
 		}
 
@@ -2561,14 +2568,14 @@
 		if (need_more_worker(pool))
 			wake_up_worker(pool);
 
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 
 		worker_detach_from_pool(rescuer);
 
-		spin_lock_irq(&wq_mayday_lock);
+		raw_spin_lock_irq(&wq_mayday_lock);
 	}
 
-	spin_unlock_irq(&wq_mayday_lock);
+	raw_spin_unlock_irq(&wq_mayday_lock);
 
 	if (should_stop) {
 		__set_current_state(TASK_RUNNING);
@@ -2648,7 +2655,7 @@
  * underneath us, so we can't reliably determine pwq from @target.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void insert_wq_barrier(struct pool_workqueue *pwq,
 			      struct wq_barrier *barr,
@@ -2735,7 +2742,7 @@
 	for_each_pwq(pwq, wq) {
 		struct worker_pool *pool = pwq->pool;
 
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 
 		if (flush_color >= 0) {
 			WARN_ON_ONCE(pwq->flush_color != -1);
@@ -2752,7 +2759,7 @@
 			pwq->work_color = work_color;
 		}
 
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 	}
 
 	if (flush_color >= 0 && atomic_dec_and_test(&wq->nr_pwqs_to_flush))
@@ -2840,7 +2847,7 @@
 	 * First flushers are responsible for cascading flushes and
 	 * handling overflow.  Non-first flushers can simply return.
 	 */
-	if (wq->first_flusher != &this_flusher)
+	if (READ_ONCE(wq->first_flusher) != &this_flusher)
 		return;
 
 	mutex_lock(&wq->mutex);
@@ -2849,7 +2856,7 @@
 	if (wq->first_flusher != &this_flusher)
 		goto out_unlock;
 
-	wq->first_flusher = NULL;
+	WRITE_ONCE(wq->first_flusher, NULL);
 
 	WARN_ON_ONCE(!list_empty(&this_flusher.list));
 	WARN_ON_ONCE(wq->flush_color != this_flusher.flush_color);
@@ -2952,9 +2959,9 @@
 	for_each_pwq(pwq, wq) {
 		bool drained;
 
-		spin_lock_irq(&pwq->pool->lock);
+		raw_spin_lock_irq(&pwq->pool->lock);
 		drained = !pwq->nr_active && list_empty(&pwq->delayed_works);
-		spin_unlock_irq(&pwq->pool->lock);
+		raw_spin_unlock_irq(&pwq->pool->lock);
 
 		if (drained)
 			continue;
@@ -2990,7 +2997,7 @@
 		return false;
 	}
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 	/* see the comment in try_to_grab_pending() with the same code */
 	pwq = get_work_pwq(work);
 	if (pwq) {
@@ -3006,7 +3013,7 @@
 	check_flush_dependency(pwq->wq, work);
 
 	insert_wq_barrier(pwq, barr, work, worker);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	/*
 	 * Force a lock recursion deadlock when using flush_work() inside a
@@ -3025,7 +3032,7 @@
 	rcu_read_unlock();
 	return true;
 already_gone:
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 	rcu_read_unlock();
 	return false;
 }
@@ -3418,7 +3425,7 @@
  */
 static int init_worker_pool(struct worker_pool *pool)
 {
-	spin_lock_init(&pool->lock);
+	raw_spin_lock_init(&pool->lock);
 	pool->id = -1;
 	pool->cpu = -1;
 	pool->node = NUMA_NO_NODE;
@@ -3495,7 +3502,6 @@
 	else
 		free_workqueue_attrs(wq->unbound_attrs);
 
-	kfree(wq->rescuer);
 	kfree(wq);
 }
 
@@ -3508,6 +3514,18 @@
 	kfree(pool);
 }
 
+/* This returns with the lock held on success (pool manager is inactive). */
+static bool wq_manager_inactive(struct worker_pool *pool)
+{
+	raw_spin_lock_irq(&pool->lock);
+
+	if (pool->flags & POOL_MANAGER_ACTIVE) {
+		raw_spin_unlock_irq(&pool->lock);
+		return false;
+	}
+	return true;
+}
+
 /**
  * put_unbound_pool - put a worker_pool
  * @pool: worker_pool to put
@@ -3543,16 +3561,17 @@
 	 * Become the manager and destroy all workers.  This prevents
 	 * @pool's workers from blocking on attach_mutex.  We're the last
 	 * manager and @pool gets freed with the flag set.
+	 * Because of how wq_manager_inactive() works, we will hold the
+	 * spinlock after a successful wait.
 	 */
-	spin_lock_irq(&pool->lock);
-	wait_event_lock_irq(wq_manager_wait,
-			    !(pool->flags & POOL_MANAGER_ACTIVE), pool->lock);
+	rcuwait_wait_event(&manager_wait, wq_manager_inactive(pool),
+			   TASK_UNINTERRUPTIBLE);
 	pool->flags |= POOL_MANAGER_ACTIVE;
 
 	while ((worker = first_idle_worker(pool)))
 		destroy_worker(worker);
 	WARN_ON(pool->nr_workers || pool->nr_idle);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	mutex_lock(&wq_pool_attach_mutex);
 	if (!list_empty(&pool->workers))
@@ -3714,7 +3733,7 @@
 		return;
 
 	/* this function can be called during early boot w/ irq disabled */
-	spin_lock_irqsave(&pwq->pool->lock, flags);
+	raw_spin_lock_irqsave(&pwq->pool->lock, flags);
 
 	/*
 	 * During [un]freezing, the caller is responsible for ensuring that
@@ -3744,7 +3763,7 @@
 		pwq->max_active = 0;
 	}
 
-	spin_unlock_irqrestore(&pwq->pool->lock, flags);
+	raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
 }
 
 /* initialize newly alloced @pwq which is associated with @wq and @pool */
@@ -4146,9 +4165,9 @@
 
 use_dfl_pwq:
 	mutex_lock(&wq->mutex);
-	spin_lock_irq(&wq->dfl_pwq->pool->lock);
+	raw_spin_lock_irq(&wq->dfl_pwq->pool->lock);
 	get_pwq(wq->dfl_pwq);
-	spin_unlock_irq(&wq->dfl_pwq->pool->lock);
+	raw_spin_unlock_irq(&wq->dfl_pwq->pool->lock);
 	old_pwq = numa_pwq_tbl_install(wq, node, wq->dfl_pwq);
 out_unlock:
 	mutex_unlock(&wq->mutex);
@@ -4225,8 +4244,8 @@
 
 	rescuer->rescue_wq = wq;
 	rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", wq->name);
-	ret = PTR_ERR_OR_ZERO(rescuer->task);
-	if (ret) {
+	if (IS_ERR(rescuer->task)) {
+		ret = PTR_ERR(rescuer->task);
 		kfree(rescuer);
 		return ret;
 	}
@@ -4336,6 +4355,22 @@
 }
 EXPORT_SYMBOL_GPL(alloc_workqueue);
 
+static bool pwq_busy(struct pool_workqueue *pwq)
+{
+	int i;
+
+	for (i = 0; i < WORK_NR_COLORS; i++)
+		if (pwq->nr_in_flight[i])
+			return true;
+
+	if ((pwq != pwq->wq->dfl_pwq) && (pwq->refcnt > 1))
+		return true;
+	if (pwq->nr_active || !list_empty(&pwq->delayed_works))
+		return true;
+
+	return false;
+}
+
 /**
  * destroy_workqueue - safely terminate a workqueue
  * @wq: target workqueue
@@ -4361,35 +4396,34 @@
 		struct worker *rescuer = wq->rescuer;
 
 		/* this prevents new queueing */
-		spin_lock_irq(&wq_mayday_lock);
+		raw_spin_lock_irq(&wq_mayday_lock);
 		wq->rescuer = NULL;
-		spin_unlock_irq(&wq_mayday_lock);
+		raw_spin_unlock_irq(&wq_mayday_lock);
 
 		/* rescuer will empty maydays list before exiting */
 		kthread_stop(rescuer->task);
 		kfree(rescuer);
 	}
 
-	/* sanity checks */
+	/*
+	 * Sanity checks - grab all the locks so that we wait for all
+	 * in-flight operations which may do put_pwq().
+	 */
+	mutex_lock(&wq_pool_mutex);
 	mutex_lock(&wq->mutex);
 	for_each_pwq(pwq, wq) {
-		int i;
-
-		for (i = 0; i < WORK_NR_COLORS; i++) {
-			if (WARN_ON(pwq->nr_in_flight[i])) {
-				mutex_unlock(&wq->mutex);
-				show_workqueue_state();
-				return;
-			}
-		}
-
-		if (WARN_ON((pwq != wq->dfl_pwq) && (pwq->refcnt > 1)) ||
-		    WARN_ON(pwq->nr_active) ||
-		    WARN_ON(!list_empty(&pwq->delayed_works))) {
+		raw_spin_lock_irq(&pwq->pool->lock);
+		if (WARN_ON(pwq_busy(pwq))) {
+			pr_warn("%s: %s has the following busy pwq\n",
+				__func__, wq->name);
+			show_pwq(pwq);
+			raw_spin_unlock_irq(&pwq->pool->lock);
 			mutex_unlock(&wq->mutex);
+			mutex_unlock(&wq_pool_mutex);
 			show_workqueue_state();
 			return;
 		}
+		raw_spin_unlock_irq(&pwq->pool->lock);
 	}
 	mutex_unlock(&wq->mutex);
 
@@ -4397,7 +4431,6 @@
 	 * wq list is used to freeze wq, remove from list after
 	 * flushing is complete in case freeze races us.
 	 */
-	mutex_lock(&wq_pool_mutex);
 	list_del_rcu(&wq->list);
 	mutex_unlock(&wq_pool_mutex);
 
@@ -4559,10 +4592,10 @@
 	rcu_read_lock();
 	pool = get_work_pool(work);
 	if (pool) {
-		spin_lock_irqsave(&pool->lock, flags);
+		raw_spin_lock_irqsave(&pool->lock, flags);
 		if (find_worker_executing_work(pool, work))
 			ret |= WORK_BUSY_RUNNING;
-		spin_unlock_irqrestore(&pool->lock, flags);
+		raw_spin_unlock_irqrestore(&pool->lock, flags);
 	}
 	rcu_read_unlock();
 
@@ -4628,11 +4661,11 @@
 	 * Carefully copy the associated workqueue's workfn, name and desc.
 	 * Keep the original last '\0' in case the original is garbage.
 	 */
-	probe_kernel_read(&fn, &worker->current_func, sizeof(fn));
-	probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq));
-	probe_kernel_read(&wq, &pwq->wq, sizeof(wq));
-	probe_kernel_read(name, wq->name, sizeof(name) - 1);
-	probe_kernel_read(desc, worker->desc, sizeof(desc) - 1);
+	copy_from_kernel_nofault(&fn, &worker->current_func, sizeof(fn));
+	copy_from_kernel_nofault(&pwq, &worker->current_pwq, sizeof(pwq));
+	copy_from_kernel_nofault(&wq, &pwq->wq, sizeof(wq));
+	copy_from_kernel_nofault(name, wq->name, sizeof(name) - 1);
+	copy_from_kernel_nofault(desc, worker->desc, sizeof(desc) - 1);
 
 	if (fn || name[0] || desc[0]) {
 		printk("%sWorkqueue: %s %ps", log_lvl, name, fn);
@@ -4695,7 +4728,7 @@
 
 			pr_cont("%s %d%s:%ps", comma ? "," : "",
 				task_pid_nr(worker->task),
-				worker == pwq->wq->rescuer ? "(RESCUER)" : "",
+				worker->rescue_wq ? "(RESCUER)" : "",
 				worker->current_func);
 			list_for_each_entry(work, &worker->scheduled, entry)
 				pr_cont_work(false, work);
@@ -4769,10 +4802,10 @@
 		pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags);
 
 		for_each_pwq(pwq, wq) {
-			spin_lock_irqsave(&pwq->pool->lock, flags);
+			raw_spin_lock_irqsave(&pwq->pool->lock, flags);
 			if (pwq->nr_active || !list_empty(&pwq->delayed_works))
 				show_pwq(pwq);
-			spin_unlock_irqrestore(&pwq->pool->lock, flags);
+			raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
 			/*
 			 * We could be printing a lot from atomic context, e.g.
 			 * sysrq-t -> show_workqueue_state(). Avoid triggering
@@ -4786,7 +4819,7 @@
 		struct worker *worker;
 		bool first = true;
 
-		spin_lock_irqsave(&pool->lock, flags);
+		raw_spin_lock_irqsave(&pool->lock, flags);
 		if (pool->nr_workers == pool->nr_idle)
 			goto next_pool;
 
@@ -4805,7 +4838,7 @@
 		}
 		pr_cont("\n");
 	next_pool:
-		spin_unlock_irqrestore(&pool->lock, flags);
+		raw_spin_unlock_irqrestore(&pool->lock, flags);
 		/*
 		 * We could be printing a lot from atomic context, e.g.
 		 * sysrq-t -> show_workqueue_state(). Avoid triggering
@@ -4835,7 +4868,7 @@
 		struct worker_pool *pool = worker->pool;
 
 		if (pool) {
-			spin_lock_irq(&pool->lock);
+			raw_spin_lock_irq(&pool->lock);
 			/*
 			 * ->desc tracks information (wq name or
 			 * set_worker_desc()) for the latest execution.  If
@@ -4849,7 +4882,7 @@
 					scnprintf(buf + off, size - off, "-%s",
 						  worker->desc);
 			}
-			spin_unlock_irq(&pool->lock);
+			raw_spin_unlock_irq(&pool->lock);
 		}
 	}
 
@@ -4880,7 +4913,7 @@
 
 	for_each_cpu_worker_pool(pool, cpu) {
 		mutex_lock(&wq_pool_attach_mutex);
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 
 		/*
 		 * We've blocked all attach/detach operations. Make all workers
@@ -4894,7 +4927,7 @@
 
 		pool->flags |= POOL_DISASSOCIATED;
 
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 		mutex_unlock(&wq_pool_attach_mutex);
 
 		/*
@@ -4920,9 +4953,9 @@
 		 * worker blocking could lead to lengthy stalls.  Kick off
 		 * unbound chain execution of currently pending work items.
 		 */
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 		wake_up_worker(pool);
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 	}
 }
 
@@ -4949,7 +4982,7 @@
 		WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task,
 						  pool->attrs->cpumask) < 0);
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	pool->flags &= ~POOL_DISASSOCIATED;
 
@@ -4988,7 +5021,7 @@
 		WRITE_ONCE(worker->flags, worker_flags);
 	}
 
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 }
 
 /**
@@ -5302,9 +5335,6 @@
 	int ret = -EINVAL;
 	cpumask_var_t saved_cpumask;
 
-	if (!zalloc_cpumask_var(&saved_cpumask, GFP_KERNEL))
-		return -ENOMEM;
-
 	/*
 	 * Not excluding isolated cpus on purpose.
 	 * If the user wishes to include them, we allow that.
@@ -5312,6 +5342,15 @@
 	cpumask_and(cpumask, cpumask, cpu_possible_mask);
 	if (!cpumask_empty(cpumask)) {
 		apply_wqattrs_lock();
+		if (cpumask_equal(cpumask, wq_unbound_cpumask)) {
+			ret = 0;
+			goto out_unlock;
+		}
+
+		if (!zalloc_cpumask_var(&saved_cpumask, GFP_KERNEL)) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
 
 		/* save the old wq_unbound_cpumask. */
 		cpumask_copy(saved_cpumask, wq_unbound_cpumask);
@@ -5324,10 +5363,11 @@
 		if (ret < 0)
 			cpumask_copy(wq_unbound_cpumask, saved_cpumask);
 
+		free_cpumask_var(saved_cpumask);
+out_unlock:
 		apply_wqattrs_unlock();
 	}
 
-	free_cpumask_var(saved_cpumask);
 	return ret;
 }
 
@@ -5910,13 +5950,13 @@
  * items.  Actual work item execution starts only after kthreads can be
  * created and scheduled right before early initcalls.
  */
-int __init workqueue_init_early(void)
+void __init workqueue_init_early(void)
 {
 	int std_nice[NR_STD_WORKER_POOLS] = { 0, HIGHPRI_NICE_LEVEL };
 	int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ;
 	int i, cpu;
 
-	WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
+	BUILD_BUG_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
 
 	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
 	cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(hk_flags));
@@ -5977,8 +6017,6 @@
 	       !system_unbound_wq || !system_freezable_wq ||
 	       !system_power_efficient_wq ||
 	       !system_freezable_power_efficient_wq);
-
-	return 0;
 }
 
 /**
@@ -5990,7 +6028,7 @@
  * are no kworkers executing the work items yet.  Populate the worker pools
  * with the initial workers and enable future kworker creations.
  */
-int __init workqueue_init(void)
+void __init workqueue_init(void)
 {
 	struct workqueue_struct *wq;
 	struct worker_pool *pool;
@@ -6037,6 +6075,4 @@
 
 	wq_online = true;
 	wq_watchdog_init();
-
-	return 0;
 }