v4.19.13 snapshot.
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
new file mode 100644
index 0000000..c596c6f
--- /dev/null
+++ b/kernel/rcu/rcutorture.c
@@ -0,0 +1,2136 @@
+/*
+ * Read-Copy Update module-based torture test facility
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * Copyright (C) IBM Corporation, 2005, 2006
+ *
+ * Authors: Paul E. McKenney <paulmck@us.ibm.com>
+ * Josh Triplett <josh@joshtriplett.org>
+ *
+ * See also: Documentation/RCU/torture.txt
+ */
+
+#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/signal.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 <linux/trace_clock.h>
+#include <asm/byteorder.h>
+#include <linux/torture.h>
+#include <linux/vmalloc.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/sysctl.h>
+
+#include "rcu.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul E. McKenney <paulmck@us.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)
+#define RCUTORTURE_RDR_BH 0x1 /* Extend readers by disabling bh. */
+#define RCUTORTURE_RDR_IRQ 0x2 /* ... disabling interrupts. */
+#define RCUTORTURE_RDR_PREEMPT 0x4 /* ... disabling preemption. */
+#define RCUTORTURE_RDR_RCU 0x8 /* ... entering another RCU reader. */
+#define RCUTORTURE_RDR_NBITS 4 /* Number of bits defined above. */
+#define RCUTORTURE_MAX_EXTEND (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | \
+ RCUTORTURE_RDR_PREEMPT)
+#define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */
+ /* Must be power of two minus one. */
+
+torture_param(int, cbflood_inter_holdoff, HZ,
+ "Holdoff between floods (jiffies)");
+torture_param(int, cbflood_intra_holdoff, 1,
+ "Holdoff between bursts (jiffies)");
+torture_param(int, cbflood_n_burst, 3, "# bursts in flood, zero to disable");
+torture_param(int, cbflood_n_per_burst, 20000,
+ "# callbacks per burst in flood");
+torture_param(int, extendables, RCUTORTURE_MAX_EXTEND,
+ "Extend readers by disabling bh (1), irqs (2), or preempt (4)");
+torture_param(int, fqs_duration, 0,
+ "Duration of fqs bursts (us), 0 to disable");
+torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
+torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
+torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives");
+torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
+torture_param(bool, gp_normal, false,
+ "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, n_barrier_cbs, 0,
+ "# of callbacks/kthreads for barrier testing");
+torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
+torture_param(int, nreaders, -1, "Number of RCU reader threads");
+torture_param(int, object_debug, 0,
+ "Enable debug-object double call_rcu() testing");
+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, 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, stat_interval, 60,
+ "Number of seconds between stats printk()s");
+torture_param(int, stutter, 5, "Number of seconds to run/halt test");
+torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
+torture_param(int, test_boost_duration, 4,
+ "Duration of each boost test, seconds.");
+torture_param(int, test_boost_interval, 7,
+ "Interval between boost tests, seconds.");
+torture_param(bool, test_no_idle_hz, true,
+ "Test support for tickless idle CPUs");
+torture_param(int, verbose, 1,
+ "Enable verbose debugging printk()s");
+
+static char *torture_type = "rcu";
+module_param(torture_type, charp, 0444);
+MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
+
+static int nrealreaders;
+static int ncbflooders;
+static struct task_struct *writer_task;
+static struct task_struct **fakewriter_tasks;
+static struct task_struct **reader_tasks;
+static struct task_struct *stats_task;
+static struct task_struct **cbflood_task;
+static struct task_struct *fqs_task;
+static struct task_struct *boost_tasks[NR_CPUS];
+static struct task_struct *stall_task;
+static struct task_struct **barrier_cbs_tasks;
+static struct task_struct *barrier_task;
+
+#define RCU_TORTURE_PIPE_LEN 10
+
+struct rcu_torture {
+ struct rcu_head rtort_rcu;
+ int rtort_pipe_count;
+ struct list_head rtort_free;
+ int rtort_mbtest;
+};
+
+static LIST_HEAD(rcu_torture_freelist);
+static struct rcu_torture __rcu *rcu_torture_current;
+static unsigned long rcu_torture_current_version;
+static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
+static DEFINE_SPINLOCK(rcu_torture_lock);
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count);
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch);
+static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
+static atomic_t n_rcu_torture_alloc;
+static atomic_t n_rcu_torture_alloc_fail;
+static atomic_t n_rcu_torture_free;
+static atomic_t n_rcu_torture_mberror;
+static atomic_t n_rcu_torture_error;
+static long n_rcu_torture_barrier_error;
+static long n_rcu_torture_boost_ktrerror;
+static long n_rcu_torture_boost_rterror;
+static long n_rcu_torture_boost_failure;
+static long n_rcu_torture_boosts;
+static atomic_long_t n_rcu_torture_timers;
+static long n_barrier_attempts;
+static long n_barrier_successes; /* did rcu_barrier test succeed? */
+static atomic_long_t n_cbfloods;
+static struct list_head rcu_torture_removed;
+
+static int rcu_torture_writer_state;
+#define RTWS_FIXED_DELAY 0
+#define RTWS_DELAY 1
+#define RTWS_REPLACE 2
+#define RTWS_DEF_FREE 3
+#define RTWS_EXP_SYNC 4
+#define RTWS_COND_GET 5
+#define RTWS_COND_SYNC 6
+#define RTWS_SYNC 7
+#define RTWS_STUTTER 8
+#define RTWS_STOPPING 9
+static const char * const rcu_torture_writer_state_names[] = {
+ "RTWS_FIXED_DELAY",
+ "RTWS_DELAY",
+ "RTWS_REPLACE",
+ "RTWS_DEF_FREE",
+ "RTWS_EXP_SYNC",
+ "RTWS_COND_GET",
+ "RTWS_COND_SYNC",
+ "RTWS_SYNC",
+ "RTWS_STUTTER",
+ "RTWS_STOPPING",
+};
+
+static const char *rcu_torture_writer_state_getname(void)
+{
+ unsigned int i = READ_ONCE(rcu_torture_writer_state);
+
+ if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
+ return "???";
+ return rcu_torture_writer_state_names[i];
+}
+
+#if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
+#define rcu_can_boost() 1
+#else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
+#define rcu_can_boost() 0
+#endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
+
+#ifdef CONFIG_RCU_TRACE
+static u64 notrace rcu_trace_clock_local(void)
+{
+ u64 ts = trace_clock_local();
+
+ (void)do_div(ts, NSEC_PER_USEC);
+ return ts;
+}
+#else /* #ifdef CONFIG_RCU_TRACE */
+static u64 notrace rcu_trace_clock_local(void)
+{
+ return 0ULL;
+}
+#endif /* #else #ifdef CONFIG_RCU_TRACE */
+
+static unsigned long boost_starttime; /* jiffies of next boost test start. */
+static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
+ /* and boost task create/destroy. */
+static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
+static bool barrier_phase; /* Test phase. */
+static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
+static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
+static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
+
+/*
+ * Allocate an element from the rcu_tortures pool.
+ */
+static struct rcu_torture *
+rcu_torture_alloc(void)
+{
+ struct list_head *p;
+
+ spin_lock_bh(&rcu_torture_lock);
+ if (list_empty(&rcu_torture_freelist)) {
+ atomic_inc(&n_rcu_torture_alloc_fail);
+ spin_unlock_bh(&rcu_torture_lock);
+ return NULL;
+ }
+ atomic_inc(&n_rcu_torture_alloc);
+ p = rcu_torture_freelist.next;
+ list_del_init(p);
+ spin_unlock_bh(&rcu_torture_lock);
+ return container_of(p, struct rcu_torture, rtort_free);
+}
+
+/*
+ * Free an element to the rcu_tortures pool.
+ */
+static void
+rcu_torture_free(struct rcu_torture *p)
+{
+ atomic_inc(&n_rcu_torture_free);
+ spin_lock_bh(&rcu_torture_lock);
+ list_add_tail(&p->rtort_free, &rcu_torture_freelist);
+ spin_unlock_bh(&rcu_torture_lock);
+}
+
+/*
+ * Operations vector for selecting different types of tests.
+ */
+
+struct rcu_torture_ops {
+ int ttype;
+ void (*init)(void);
+ void (*cleanup)(void);
+ int (*readlock)(void);
+ void (*read_delay)(struct torture_random_state *rrsp);
+ void (*readunlock)(int idx);
+ unsigned long (*get_gp_seq)(void);
+ unsigned long (*gp_diff)(unsigned long new, unsigned long old);
+ void (*deferred_free)(struct rcu_torture *p);
+ void (*sync)(void);
+ void (*exp_sync)(void);
+ unsigned long (*get_state)(void);
+ void (*cond_sync)(unsigned long oldstate);
+ call_rcu_func_t call;
+ void (*cb_barrier)(void);
+ void (*fqs)(void);
+ void (*stats)(void);
+ int irq_capable;
+ int can_boost;
+ int extendables;
+ int ext_irq_conflict;
+ const char *name;
+};
+
+static struct rcu_torture_ops *cur_ops;
+
+/*
+ * Definitions for rcu torture testing.
+ */
+
+static int rcu_torture_read_lock(void) __acquires(RCU)
+{
+ rcu_read_lock();
+ return 0;
+}
+
+static void rcu_read_delay(struct torture_random_state *rrsp)
+{
+ unsigned long started;
+ unsigned long completed;
+ const unsigned long shortdelay_us = 200;
+ const unsigned long longdelay_ms = 50;
+ unsigned long long ts;
+
+ /* We want a short delay sometimes to make a reader delay the grace
+ * period, and we want a long delay occasionally to trigger
+ * force_quiescent_state. */
+
+ if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
+ started = cur_ops->get_gp_seq();
+ ts = rcu_trace_clock_local();
+ mdelay(longdelay_ms);
+ completed = cur_ops->get_gp_seq();
+ do_trace_rcu_torture_read(cur_ops->name, NULL, ts,
+ started, completed);
+ }
+ if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
+ udelay(shortdelay_us);
+ if (!preempt_count() &&
+ !(torture_random(rrsp) % (nrealreaders * 500)))
+ torture_preempt_schedule(); /* QS only if preemptible. */
+}
+
+static void rcu_torture_read_unlock(int idx) __releases(RCU)
+{
+ rcu_read_unlock();
+}
+
+/*
+ * Update callback in the pipe. This should be invoked after a grace period.
+ */
+static bool
+rcu_torture_pipe_update_one(struct rcu_torture *rp)
+{
+ int i;
+
+ i = 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) {
+ rp->rtort_mbtest = 0;
+ return true;
+ }
+ return false;
+}
+
+/*
+ * Update all callbacks in the pipe. Suitable for synchronous grace-period
+ * primitives.
+ */
+static void
+rcu_torture_pipe_update(struct rcu_torture *old_rp)
+{
+ struct rcu_torture *rp;
+ struct rcu_torture *rp1;
+
+ if (old_rp)
+ list_add(&old_rp->rtort_free, &rcu_torture_removed);
+ list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
+ if (rcu_torture_pipe_update_one(rp)) {
+ list_del(&rp->rtort_free);
+ rcu_torture_free(rp);
+ }
+ }
+}
+
+static void
+rcu_torture_cb(struct rcu_head *p)
+{
+ struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
+
+ if (torture_must_stop_irq()) {
+ /* Test is ending, just drop callbacks on the floor. */
+ /* The next initialization will pick up the pieces. */
+ return;
+ }
+ if (rcu_torture_pipe_update_one(rp))
+ rcu_torture_free(rp);
+ else
+ cur_ops->deferred_free(rp);
+}
+
+static unsigned long rcu_no_completed(void)
+{
+ return 0;
+}
+
+static void rcu_torture_deferred_free(struct rcu_torture *p)
+{
+ call_rcu(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static void rcu_sync_torture_init(void)
+{
+ INIT_LIST_HEAD(&rcu_torture_removed);
+}
+
+static struct rcu_torture_ops rcu_ops = {
+ .ttype = RCU_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = rcu_torture_read_lock,
+ .read_delay = rcu_read_delay,
+ .readunlock = rcu_torture_read_unlock,
+ .get_gp_seq = rcu_get_gp_seq,
+ .gp_diff = rcu_seq_diff,
+ .deferred_free = rcu_torture_deferred_free,
+ .sync = synchronize_rcu,
+ .exp_sync = synchronize_rcu_expedited,
+ .get_state = get_state_synchronize_rcu,
+ .cond_sync = cond_synchronize_rcu,
+ .call = call_rcu,
+ .cb_barrier = rcu_barrier,
+ .fqs = rcu_force_quiescent_state,
+ .stats = NULL,
+ .irq_capable = 1,
+ .can_boost = rcu_can_boost(),
+ .name = "rcu"
+};
+
+/*
+ * Definitions for rcu_bh torture testing.
+ */
+
+static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
+{
+ rcu_read_lock_bh();
+ return 0;
+}
+
+static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
+{
+ rcu_read_unlock_bh();
+}
+
+static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
+{
+ call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops rcu_bh_ops = {
+ .ttype = RCU_BH_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = rcu_bh_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = rcu_bh_torture_read_unlock,
+ .get_gp_seq = rcu_bh_get_gp_seq,
+ .gp_diff = rcu_seq_diff,
+ .deferred_free = rcu_bh_torture_deferred_free,
+ .sync = synchronize_rcu_bh,
+ .exp_sync = synchronize_rcu_bh_expedited,
+ .call = call_rcu_bh,
+ .cb_barrier = rcu_barrier_bh,
+ .fqs = rcu_bh_force_quiescent_state,
+ .stats = NULL,
+ .irq_capable = 1,
+ .extendables = (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ),
+ .ext_irq_conflict = RCUTORTURE_RDR_RCU,
+ .name = "rcu_bh"
+};
+
+/*
+ * Don't even think about trying any of these in real life!!!
+ * The names includes "busted", and they really means it!
+ * The only purpose of these functions is to provide a buggy RCU
+ * implementation to make sure that rcutorture correctly emits
+ * buggy-RCU error messages.
+ */
+static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
+{
+ /* This is a deliberate bug for testing purposes only! */
+ rcu_torture_cb(&p->rtort_rcu);
+}
+
+static void synchronize_rcu_busted(void)
+{
+ /* This is a deliberate bug for testing purposes only! */
+}
+
+static void
+call_rcu_busted(struct rcu_head *head, rcu_callback_t func)
+{
+ /* This is a deliberate bug for testing purposes only! */
+ func(head);
+}
+
+static struct rcu_torture_ops rcu_busted_ops = {
+ .ttype = INVALID_RCU_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = rcu_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = rcu_torture_read_unlock,
+ .get_gp_seq = rcu_no_completed,
+ .deferred_free = rcu_busted_torture_deferred_free,
+ .sync = synchronize_rcu_busted,
+ .exp_sync = synchronize_rcu_busted,
+ .call = call_rcu_busted,
+ .cb_barrier = NULL,
+ .fqs = NULL,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "busted"
+};
+
+/*
+ * Definitions for srcu torture testing.
+ */
+
+DEFINE_STATIC_SRCU(srcu_ctl);
+static struct srcu_struct srcu_ctld;
+static struct srcu_struct *srcu_ctlp = &srcu_ctl;
+
+static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)
+{
+ return srcu_read_lock(srcu_ctlp);
+}
+
+static void srcu_read_delay(struct torture_random_state *rrsp)
+{
+ long delay;
+ const long uspertick = 1000000 / HZ;
+ const long longdelay = 10;
+
+ /* We want there to be long-running readers, but not all the time. */
+
+ delay = torture_random(rrsp) %
+ (nrealreaders * 2 * longdelay * uspertick);
+ if (!delay && in_task())
+ schedule_timeout_interruptible(longdelay);
+ else
+ rcu_read_delay(rrsp);
+}
+
+static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
+{
+ srcu_read_unlock(srcu_ctlp, idx);
+}
+
+static unsigned long srcu_torture_completed(void)
+{
+ return srcu_batches_completed(srcu_ctlp);
+}
+
+static void srcu_torture_deferred_free(struct rcu_torture *rp)
+{
+ call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);
+}
+
+static void srcu_torture_synchronize(void)
+{
+ synchronize_srcu(srcu_ctlp);
+}
+
+static void srcu_torture_call(struct rcu_head *head,
+ rcu_callback_t func)
+{
+ call_srcu(srcu_ctlp, head, func);
+}
+
+static void srcu_torture_barrier(void)
+{
+ srcu_barrier(srcu_ctlp);
+}
+
+static void srcu_torture_stats(void)
+{
+ srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG);
+}
+
+static void srcu_torture_synchronize_expedited(void)
+{
+ synchronize_srcu_expedited(srcu_ctlp);
+}
+
+static struct rcu_torture_ops srcu_ops = {
+ .ttype = SRCU_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = srcu_torture_read_lock,
+ .read_delay = srcu_read_delay,
+ .readunlock = srcu_torture_read_unlock,
+ .get_gp_seq = srcu_torture_completed,
+ .deferred_free = srcu_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
+ .exp_sync = srcu_torture_synchronize_expedited,
+ .call = srcu_torture_call,
+ .cb_barrier = srcu_torture_barrier,
+ .stats = srcu_torture_stats,
+ .irq_capable = 1,
+ .name = "srcu"
+};
+
+static void srcu_torture_init(void)
+{
+ rcu_sync_torture_init();
+ WARN_ON(init_srcu_struct(&srcu_ctld));
+ srcu_ctlp = &srcu_ctld;
+}
+
+static void srcu_torture_cleanup(void)
+{
+ static DEFINE_TORTURE_RANDOM(rand);
+
+ if (torture_random(&rand) & 0x800)
+ cleanup_srcu_struct(&srcu_ctld);
+ else
+ cleanup_srcu_struct_quiesced(&srcu_ctld);
+ srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
+}
+
+/* As above, but dynamically allocated. */
+static struct rcu_torture_ops srcud_ops = {
+ .ttype = SRCU_FLAVOR,
+ .init = srcu_torture_init,
+ .cleanup = srcu_torture_cleanup,
+ .readlock = srcu_torture_read_lock,
+ .read_delay = srcu_read_delay,
+ .readunlock = srcu_torture_read_unlock,
+ .get_gp_seq = srcu_torture_completed,
+ .deferred_free = srcu_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
+ .exp_sync = srcu_torture_synchronize_expedited,
+ .call = srcu_torture_call,
+ .cb_barrier = srcu_torture_barrier,
+ .stats = srcu_torture_stats,
+ .irq_capable = 1,
+ .name = "srcud"
+};
+
+/* As above, but broken due to inappropriate reader extension. */
+static struct rcu_torture_ops busted_srcud_ops = {
+ .ttype = SRCU_FLAVOR,
+ .init = srcu_torture_init,
+ .cleanup = srcu_torture_cleanup,
+ .readlock = srcu_torture_read_lock,
+ .read_delay = rcu_read_delay,
+ .readunlock = srcu_torture_read_unlock,
+ .get_gp_seq = srcu_torture_completed,
+ .deferred_free = srcu_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
+ .exp_sync = srcu_torture_synchronize_expedited,
+ .call = srcu_torture_call,
+ .cb_barrier = srcu_torture_barrier,
+ .stats = srcu_torture_stats,
+ .irq_capable = 1,
+ .extendables = RCUTORTURE_MAX_EXTEND,
+ .name = "busted_srcud"
+};
+
+/*
+ * Definitions for sched torture testing.
+ */
+
+static int sched_torture_read_lock(void)
+{
+ preempt_disable();
+ return 0;
+}
+
+static void sched_torture_read_unlock(int idx)
+{
+ preempt_enable();
+}
+
+static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
+{
+ call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops sched_ops = {
+ .ttype = RCU_SCHED_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = sched_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = sched_torture_read_unlock,
+ .get_gp_seq = rcu_sched_get_gp_seq,
+ .gp_diff = rcu_seq_diff,
+ .deferred_free = rcu_sched_torture_deferred_free,
+ .sync = synchronize_sched,
+ .exp_sync = synchronize_sched_expedited,
+ .get_state = get_state_synchronize_sched,
+ .cond_sync = cond_synchronize_sched,
+ .call = call_rcu_sched,
+ .cb_barrier = rcu_barrier_sched,
+ .fqs = rcu_sched_force_quiescent_state,
+ .stats = NULL,
+ .irq_capable = 1,
+ .extendables = RCUTORTURE_MAX_EXTEND,
+ .name = "sched"
+};
+
+/*
+ * Definitions for RCU-tasks torture testing.
+ */
+
+static int tasks_torture_read_lock(void)
+{
+ return 0;
+}
+
+static void tasks_torture_read_unlock(int idx)
+{
+}
+
+static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
+{
+ call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops tasks_ops = {
+ .ttype = RCU_TASKS_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = tasks_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = tasks_torture_read_unlock,
+ .get_gp_seq = rcu_no_completed,
+ .deferred_free = rcu_tasks_torture_deferred_free,
+ .sync = synchronize_rcu_tasks,
+ .exp_sync = synchronize_rcu_tasks,
+ .call = call_rcu_tasks,
+ .cb_barrier = rcu_barrier_tasks,
+ .fqs = NULL,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "tasks"
+};
+
+static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
+{
+ if (!cur_ops->gp_diff)
+ return new - old;
+ return cur_ops->gp_diff(new, old);
+}
+
+static bool __maybe_unused torturing_tasks(void)
+{
+ return cur_ops == &tasks_ops;
+}
+
+/*
+ * RCU torture priority-boost testing. Runs one real-time thread per
+ * CPU for moderate bursts, repeatedly registering RCU callbacks and
+ * spinning waiting for them to be invoked. If a given callback takes
+ * too long to be invoked, we assume that priority inversion has occurred.
+ */
+
+struct rcu_boost_inflight {
+ struct rcu_head rcu;
+ int inflight;
+};
+
+static void rcu_torture_boost_cb(struct rcu_head *head)
+{
+ struct rcu_boost_inflight *rbip =
+ container_of(head, struct rcu_boost_inflight, rcu);
+
+ /* Ensure RCU-core accesses precede clearing ->inflight */
+ smp_store_release(&rbip->inflight, 0);
+}
+
+static int old_rt_runtime = -1;
+
+static void rcu_torture_disable_rt_throttle(void)
+{
+ /*
+ * Disable RT throttling so that rcutorture's boost threads don't get
+ * throttled. Only possible if rcutorture is built-in otherwise the
+ * user should manually do this by setting the sched_rt_period_us and
+ * sched_rt_runtime sysctls.
+ */
+ if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1)
+ return;
+
+ old_rt_runtime = sysctl_sched_rt_runtime;
+ sysctl_sched_rt_runtime = -1;
+}
+
+static void rcu_torture_enable_rt_throttle(void)
+{
+ if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1)
+ return;
+
+ sysctl_sched_rt_runtime = old_rt_runtime;
+ old_rt_runtime = -1;
+}
+
+static bool rcu_torture_boost_failed(unsigned long start, unsigned long end)
+{
+ if (end - start > test_boost_duration * HZ - HZ / 2) {
+ VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
+ n_rcu_torture_boost_failure++;
+
+ return true; /* failed */
+ }
+
+ return false; /* passed */
+}
+
+static int rcu_torture_boost(void *arg)
+{
+ unsigned long call_rcu_time;
+ 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++;
+ }
+
+ init_rcu_head_on_stack(&rbi.rcu);
+ /* Each pass through the following loop does one boost-test cycle. */
+ do {
+ /* Track if the test failed already in this test interval? */
+ bool failed = false;
+
+ /* Increment n_rcu_torture_boosts once per boost-test */
+ while (!kthread_should_stop()) {
+ if (mutex_trylock(&boost_mutex)) {
+ n_rcu_torture_boosts++;
+ mutex_unlock(&boost_mutex);
+ break;
+ }
+ schedule_timeout_uninterruptible(1);
+ }
+ if (kthread_should_stop())
+ goto checkwait;
+
+ /* Wait for the next test interval. */
+ oldstarttime = boost_starttime;
+ while (ULONG_CMP_LT(jiffies, oldstarttime)) {
+ schedule_timeout_interruptible(oldstarttime - jiffies);
+ stutter_wait("rcu_torture_boost");
+ if (torture_must_stop())
+ goto checkwait;
+ }
+
+ /* Do one boost-test interval. */
+ endtime = oldstarttime + test_boost_duration * HZ;
+ call_rcu_time = jiffies;
+ while (ULONG_CMP_LT(jiffies, endtime)) {
+ /* If we don't have a callback in flight, post one. */
+ if (!smp_load_acquire(&rbi.inflight)) {
+ /* RCU core before ->inflight = 1. */
+ smp_store_release(&rbi.inflight, 1);
+ call_rcu(&rbi.rcu, rcu_torture_boost_cb);
+ /* Check if the boost test failed */
+ failed = failed ||
+ rcu_torture_boost_failed(call_rcu_time,
+ jiffies);
+ call_rcu_time = jiffies;
+ }
+ stutter_wait("rcu_torture_boost");
+ if (torture_must_stop())
+ goto checkwait;
+ }
+
+ /*
+ * If boost never happened, then inflight will always be 1, in
+ * this case the boost check would never happen in the above
+ * loop so do another one here.
+ */
+ if (!failed && smp_load_acquire(&rbi.inflight))
+ rcu_torture_boost_failed(call_rcu_time, jiffies);
+
+ /*
+ * Set the start time of the next test interval.
+ * Yes, this is vulnerable to long delays, but such
+ * delays simply cause a false negative for the next
+ * interval. Besides, we are running at RT priority,
+ * so delays should be relatively rare.
+ */
+ while (oldstarttime == boost_starttime &&
+ !kthread_should_stop()) {
+ if (mutex_trylock(&boost_mutex)) {
+ boost_starttime = jiffies +
+ test_boost_interval * HZ;
+ mutex_unlock(&boost_mutex);
+ break;
+ }
+ schedule_timeout_uninterruptible(1);
+ }
+
+ /* Go do the stutter. */
+checkwait: stutter_wait("rcu_torture_boost");
+ } while (!torture_must_stop());
+
+ /* Clean up and exit. */
+ while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
+ torture_shutdown_absorb("rcu_torture_boost");
+ schedule_timeout_uninterruptible(1);
+ }
+ destroy_rcu_head_on_stack(&rbi.rcu);
+ torture_kthread_stopping("rcu_torture_boost");
+ return 0;
+}
+
+static void rcu_torture_cbflood_cb(struct rcu_head *rhp)
+{
+}
+
+/*
+ * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
+ * to call_rcu() or analogous, increasing the probability of occurrence
+ * of callback-overflow corner cases.
+ */
+static int
+rcu_torture_cbflood(void *arg)
+{
+ int err = 1;
+ int i;
+ int j;
+ struct rcu_head *rhp;
+
+ if (cbflood_n_per_burst > 0 &&
+ cbflood_inter_holdoff > 0 &&
+ cbflood_intra_holdoff > 0 &&
+ cur_ops->call &&
+ cur_ops->cb_barrier) {
+ rhp = vmalloc(array3_size(cbflood_n_burst,
+ cbflood_n_per_burst,
+ sizeof(*rhp)));
+ err = !rhp;
+ }
+ if (err) {
+ VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
+ goto wait_for_stop;
+ }
+ VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
+ do {
+ schedule_timeout_interruptible(cbflood_inter_holdoff);
+ atomic_long_inc(&n_cbfloods);
+ WARN_ON(signal_pending(current));
+ for (i = 0; i < cbflood_n_burst; i++) {
+ for (j = 0; j < cbflood_n_per_burst; j++) {
+ cur_ops->call(&rhp[i * cbflood_n_per_burst + j],
+ rcu_torture_cbflood_cb);
+ }
+ schedule_timeout_interruptible(cbflood_intra_holdoff);
+ WARN_ON(signal_pending(current));
+ }
+ cur_ops->cb_barrier();
+ stutter_wait("rcu_torture_cbflood");
+ } while (!torture_must_stop());
+ vfree(rhp);
+wait_for_stop:
+ torture_kthread_stopping("rcu_torture_cbflood");
+ return 0;
+}
+
+/*
+ * RCU torture force-quiescent-state kthread. Repeatedly induces
+ * bursts of calls to force_quiescent_state(), increasing the probability
+ * of occurrence of some important types of race conditions.
+ */
+static int
+rcu_torture_fqs(void *arg)
+{
+ unsigned long fqs_resume_time;
+ int fqs_burst_remaining;
+
+ VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
+ do {
+ fqs_resume_time = jiffies + fqs_stutter * HZ;
+ while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
+ !kthread_should_stop()) {
+ schedule_timeout_interruptible(1);
+ }
+ fqs_burst_remaining = fqs_duration;
+ while (fqs_burst_remaining > 0 &&
+ !kthread_should_stop()) {
+ cur_ops->fqs();
+ udelay(fqs_holdoff);
+ fqs_burst_remaining -= fqs_holdoff;
+ }
+ stutter_wait("rcu_torture_fqs");
+ } while (!torture_must_stop());
+ torture_kthread_stopping("rcu_torture_fqs");
+ return 0;
+}
+
+/*
+ * RCU torture writer kthread. Repeatedly substitutes a new structure
+ * for that pointed to by rcu_torture_current, freeing the old structure
+ * after a series of grace periods (the "pipeline").
+ */
+static int
+rcu_torture_writer(void *arg)
+{
+ bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
+ int expediting = 0;
+ unsigned long gp_snap;
+ bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
+ bool gp_sync1 = gp_sync;
+ int i;
+ struct rcu_torture *rp;
+ struct rcu_torture *old_rp;
+ static DEFINE_TORTURE_RANDOM(rand);
+ int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
+ RTWS_COND_GET, RTWS_SYNC };
+ int nsynctypes = 0;
+
+ VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
+ if (!can_expedite)
+ pr_alert("%s" TORTURE_FLAG
+ " GP expediting controlled from boot/sysfs for %s.\n",
+ torture_type, cur_ops->name);
+
+ /* Initialize synctype[] array. If none set, take default. */
+ if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
+ gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
+ if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync) {
+ synctype[nsynctypes++] = RTWS_COND_GET;
+ pr_info("%s: Testing conditional GPs.\n", __func__);
+ } else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync)) {
+ pr_alert("%s: gp_cond without primitives.\n", __func__);
+ }
+ if (gp_exp1 && cur_ops->exp_sync) {
+ synctype[nsynctypes++] = RTWS_EXP_SYNC;
+ pr_info("%s: Testing expedited GPs.\n", __func__);
+ } else if (gp_exp && !cur_ops->exp_sync) {
+ pr_alert("%s: gp_exp without primitives.\n", __func__);
+ }
+ if (gp_normal1 && cur_ops->deferred_free) {
+ synctype[nsynctypes++] = RTWS_DEF_FREE;
+ pr_info("%s: Testing asynchronous GPs.\n", __func__);
+ } else if (gp_normal && !cur_ops->deferred_free) {
+ pr_alert("%s: gp_normal without primitives.\n", __func__);
+ }
+ if (gp_sync1 && cur_ops->sync) {
+ synctype[nsynctypes++] = RTWS_SYNC;
+ pr_info("%s: Testing normal GPs.\n", __func__);
+ } else if (gp_sync && !cur_ops->sync) {
+ pr_alert("%s: gp_sync without primitives.\n", __func__);
+ }
+ if (WARN_ONCE(nsynctypes == 0,
+ "rcu_torture_writer: No update-side primitives.\n")) {
+ /*
+ * No updates primitives, so don't try updating.
+ * The resulting test won't be testing much, hence the
+ * above WARN_ONCE().
+ */
+ rcu_torture_writer_state = RTWS_STOPPING;
+ torture_kthread_stopping("rcu_torture_writer");
+ }
+
+ do {
+ rcu_torture_writer_state = RTWS_FIXED_DELAY;
+ schedule_timeout_uninterruptible(1);
+ rp = rcu_torture_alloc();
+ if (rp == NULL)
+ continue;
+ rp->rtort_pipe_count = 0;
+ rcu_torture_writer_state = RTWS_DELAY;
+ udelay(torture_random(&rand) & 0x3ff);
+ rcu_torture_writer_state = RTWS_REPLACE;
+ old_rp = rcu_dereference_check(rcu_torture_current,
+ current == writer_task);
+ rp->rtort_mbtest = 1;
+ rcu_assign_pointer(rcu_torture_current, rp);
+ smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
+ if (old_rp) {
+ i = old_rp->rtort_pipe_count;
+ if (i > RCU_TORTURE_PIPE_LEN)
+ i = RCU_TORTURE_PIPE_LEN;
+ atomic_inc(&rcu_torture_wcount[i]);
+ old_rp->rtort_pipe_count++;
+ switch (synctype[torture_random(&rand) % nsynctypes]) {
+ case RTWS_DEF_FREE:
+ rcu_torture_writer_state = RTWS_DEF_FREE;
+ cur_ops->deferred_free(old_rp);
+ break;
+ case RTWS_EXP_SYNC:
+ rcu_torture_writer_state = RTWS_EXP_SYNC;
+ cur_ops->exp_sync();
+ rcu_torture_pipe_update(old_rp);
+ break;
+ case RTWS_COND_GET:
+ rcu_torture_writer_state = RTWS_COND_GET;
+ gp_snap = cur_ops->get_state();
+ i = torture_random(&rand) % 16;
+ if (i != 0)
+ schedule_timeout_interruptible(i);
+ udelay(torture_random(&rand) % 1000);
+ rcu_torture_writer_state = RTWS_COND_SYNC;
+ cur_ops->cond_sync(gp_snap);
+ rcu_torture_pipe_update(old_rp);
+ break;
+ case RTWS_SYNC:
+ rcu_torture_writer_state = RTWS_SYNC;
+ cur_ops->sync();
+ rcu_torture_pipe_update(old_rp);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ break;
+ }
+ }
+ rcu_torture_current_version++;
+ /* Cycle through nesting levels of rcu_expedite_gp() calls. */
+ if (can_expedite &&
+ !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
+ WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
+ if (expediting >= 0)
+ rcu_expedite_gp();
+ else
+ rcu_unexpedite_gp();
+ if (++expediting > 3)
+ expediting = -expediting;
+ } else if (!can_expedite) { /* Disabled during boot, recheck. */
+ can_expedite = !rcu_gp_is_expedited() &&
+ !rcu_gp_is_normal();
+ }
+ rcu_torture_writer_state = RTWS_STUTTER;
+ stutter_wait("rcu_torture_writer");
+ } while (!torture_must_stop());
+ /* Reset expediting back to unexpedited. */
+ if (expediting > 0)
+ expediting = -expediting;
+ while (can_expedite && expediting++ < 0)
+ rcu_unexpedite_gp();
+ WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
+ if (!can_expedite)
+ pr_alert("%s" TORTURE_FLAG
+ " Dynamic grace-period expediting was disabled.\n",
+ torture_type);
+ rcu_torture_writer_state = RTWS_STOPPING;
+ torture_kthread_stopping("rcu_torture_writer");
+ return 0;
+}
+
+/*
+ * RCU torture fake writer kthread. Repeatedly calls sync, with a random
+ * delay between calls.
+ */
+static int
+rcu_torture_fakewriter(void *arg)
+{
+ DEFINE_TORTURE_RANDOM(rand);
+
+ VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
+ set_user_nice(current, MAX_NICE);
+
+ do {
+ schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
+ udelay(torture_random(&rand) & 0x3ff);
+ if (cur_ops->cb_barrier != NULL &&
+ torture_random(&rand) % (nfakewriters * 8) == 0) {
+ cur_ops->cb_barrier();
+ } else if (gp_normal == gp_exp) {
+ if (cur_ops->sync && torture_random(&rand) & 0x80)
+ cur_ops->sync();
+ else if (cur_ops->exp_sync)
+ cur_ops->exp_sync();
+ } else if (gp_normal && cur_ops->sync) {
+ cur_ops->sync();
+ } else if (cur_ops->exp_sync) {
+ cur_ops->exp_sync();
+ }
+ stutter_wait("rcu_torture_fakewriter");
+ } while (!torture_must_stop());
+
+ torture_kthread_stopping("rcu_torture_fakewriter");
+ return 0;
+}
+
+static void rcu_torture_timer_cb(struct rcu_head *rhp)
+{
+ kfree(rhp);
+}
+
+/*
+ * Do one extension of an RCU read-side critical section using the
+ * current reader state in readstate (set to zero for initial entry
+ * to extended critical section), set the new state as specified by
+ * newstate (set to zero for final exit from extended critical section),
+ * and random-number-generator state in trsp. If this is neither the
+ * beginning or end of the critical section and if there was actually a
+ * change, do a ->read_delay().
+ */
+static void rcutorture_one_extend(int *readstate, int newstate,
+ struct torture_random_state *trsp)
+{
+ int idxnew = -1;
+ int idxold = *readstate;
+ int statesnew = ~*readstate & newstate;
+ int statesold = *readstate & ~newstate;
+
+ WARN_ON_ONCE(idxold < 0);
+ WARN_ON_ONCE((idxold >> RCUTORTURE_RDR_SHIFT) > 1);
+
+ /* First, put new protection in place to avoid critical-section gap. */
+ if (statesnew & RCUTORTURE_RDR_BH)
+ local_bh_disable();
+ if (statesnew & RCUTORTURE_RDR_IRQ)
+ local_irq_disable();
+ if (statesnew & RCUTORTURE_RDR_PREEMPT)
+ preempt_disable();
+ if (statesnew & RCUTORTURE_RDR_RCU)
+ idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT;
+
+ /* Next, remove old protection, irq first due to bh conflict. */
+ 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_RCU)
+ cur_ops->readunlock(idxold >> RCUTORTURE_RDR_SHIFT);
+
+ /* Delay if neither beginning nor end and there was a change. */
+ if ((statesnew || statesold) && *readstate && newstate)
+ cur_ops->read_delay(trsp);
+
+ /* Update the reader state. */
+ if (idxnew == -1)
+ idxnew = idxold & ~RCUTORTURE_RDR_MASK;
+ WARN_ON_ONCE(idxnew < 0);
+ WARN_ON_ONCE((idxnew >> RCUTORTURE_RDR_SHIFT) > 1);
+ *readstate = idxnew | newstate;
+ WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) < 0);
+ WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) > 1);
+}
+
+/* Return the biggest extendables mask given current RCU and boot parameters. */
+static int rcutorture_extend_mask_max(void)
+{
+ int mask;
+
+ WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND);
+ mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables;
+ mask = mask | RCUTORTURE_RDR_RCU;
+ return mask;
+}
+
+/* Return a random protection state mask, but with at least one bit set. */
+static int
+rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp)
+{
+ int mask = rcutorture_extend_mask_max();
+ unsigned long randmask1 = torture_random(trsp) >> 8;
+ unsigned long randmask2 = randmask1 >> 1;
+
+ WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT);
+ /* Half the time lots of bits, half the time only one bit. */
+ if (randmask1 & 0x1)
+ mask = mask & randmask2;
+ else
+ mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS));
+ if ((mask & RCUTORTURE_RDR_IRQ) &&
+ !(mask & RCUTORTURE_RDR_BH) &&
+ (oldmask & RCUTORTURE_RDR_BH))
+ mask |= RCUTORTURE_RDR_BH; /* Can't enable bh w/irq disabled. */
+ if ((mask & RCUTORTURE_RDR_IRQ) &&
+ !(mask & cur_ops->ext_irq_conflict) &&
+ (oldmask & cur_ops->ext_irq_conflict))
+ mask |= cur_ops->ext_irq_conflict; /* Or if readers object. */
+ return mask ?: RCUTORTURE_RDR_RCU;
+}
+
+/*
+ * Do a randomly selected number of extensions of an existing RCU read-side
+ * critical section.
+ */
+static void rcutorture_loop_extend(int *readstate,
+ struct torture_random_state *trsp)
+{
+ int i;
+ int mask = rcutorture_extend_mask_max();
+
+ WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */
+ if (!((mask - 1) & mask))
+ return; /* Current RCU flavor not extendable. */
+ i = (torture_random(trsp) >> 3) & RCUTORTURE_RDR_MAX_LOOPS;
+ while (i--) {
+ mask = rcutorture_extend_mask(*readstate, trsp);
+ rcutorture_one_extend(readstate, mask, trsp);
+ }
+}
+
+/*
+ * Do one read-side critical section, returning false if there was
+ * no data to read. Can be invoked both from process context and
+ * from a timer handler.
+ */
+static bool rcu_torture_one_read(struct torture_random_state *trsp)
+{
+ unsigned long started;
+ unsigned long completed;
+ int newstate;
+ struct rcu_torture *p;
+ int pipe_count;
+ int readstate = 0;
+ unsigned long long ts;
+
+ newstate = rcutorture_extend_mask(readstate, trsp);
+ rcutorture_one_extend(&readstate, newstate, trsp);
+ started = cur_ops->get_gp_seq();
+ ts = rcu_trace_clock_local();
+ p = rcu_dereference_check(rcu_torture_current,
+ rcu_read_lock_bh_held() ||
+ rcu_read_lock_sched_held() ||
+ srcu_read_lock_held(srcu_ctlp) ||
+ torturing_tasks());
+ if (p == NULL) {
+ /* Wait for rcu_torture_writer to get underway */
+ rcutorture_one_extend(&readstate, 0, trsp);
+ return false;
+ }
+ if (p->rtort_mbtest == 0)
+ atomic_inc(&n_rcu_torture_mberror);
+ rcutorture_loop_extend(&readstate, trsp);
+ preempt_disable();
+ pipe_count = p->rtort_pipe_count;
+ if (pipe_count > RCU_TORTURE_PIPE_LEN) {
+ /* Should not happen, but... */
+ pipe_count = RCU_TORTURE_PIPE_LEN;
+ }
+ completed = cur_ops->get_gp_seq();
+ if (pipe_count > 1) {
+ do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
+ ts, started, completed);
+ rcu_ftrace_dump(DUMP_ALL);
+ }
+ __this_cpu_inc(rcu_torture_count[pipe_count]);
+ completed = rcutorture_seq_diff(completed, started);
+ if (completed > RCU_TORTURE_PIPE_LEN) {
+ /* Should not happen, but... */
+ completed = RCU_TORTURE_PIPE_LEN;
+ }
+ __this_cpu_inc(rcu_torture_batch[completed]);
+ preempt_enable();
+ rcutorture_one_extend(&readstate, 0, trsp);
+ WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK);
+ return true;
+}
+
+static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand);
+
+/*
+ * RCU torture reader from timer handler. Dereferences rcu_torture_current,
+ * incrementing the corresponding element of the pipeline array. The
+ * counter in the element should never be greater than 1, otherwise, the
+ * RCU implementation is broken.
+ */
+static void rcu_torture_timer(struct timer_list *unused)
+{
+ atomic_long_inc(&n_rcu_torture_timers);
+ (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand));
+
+ /* Test call_rcu() invocation from interrupt handler. */
+ if (cur_ops->call) {
+ struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT);
+
+ if (rhp)
+ cur_ops->call(rhp, rcu_torture_timer_cb);
+ }
+}
+
+/*
+ * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
+ * incrementing the corresponding element of the pipeline array. The
+ * counter in the element should never be greater than 1, otherwise, the
+ * RCU implementation is broken.
+ */
+static int
+rcu_torture_reader(void *arg)
+{
+ DEFINE_TORTURE_RANDOM(rand);
+ struct timer_list t;
+
+ VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
+ set_user_nice(current, MAX_NICE);
+ if (irqreader && cur_ops->irq_capable)
+ timer_setup_on_stack(&t, rcu_torture_timer, 0);
+
+ do {
+ if (irqreader && cur_ops->irq_capable) {
+ if (!timer_pending(&t))
+ mod_timer(&t, jiffies + 1);
+ }
+ if (!rcu_torture_one_read(&rand))
+ schedule_timeout_interruptible(HZ);
+ stutter_wait("rcu_torture_reader");
+ } while (!torture_must_stop());
+ if (irqreader && cur_ops->irq_capable) {
+ del_timer_sync(&t);
+ destroy_timer_on_stack(&t);
+ }
+ torture_kthread_stopping("rcu_torture_reader");
+ return 0;
+}
+
+/*
+ * Print torture statistics. Caller must ensure that there is only
+ * one call to this function at a given time!!! This is normally
+ * accomplished by relying on the module system to only have one copy
+ * of the module loaded, and then by giving the rcu_torture_stats
+ * kthread full control (or the init/cleanup functions when rcu_torture_stats
+ * thread is not running).
+ */
+static void
+rcu_torture_stats_print(void)
+{
+ int cpu;
+ int i;
+ long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
+ long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
+ 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];
+ }
+ }
+ for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
+ if (pipesummary[i] != 0)
+ break;
+ }
+
+ pr_alert("%s%s ", torture_type, TORTURE_FLAG);
+ pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
+ rcu_torture_current,
+ rcu_torture_current_version,
+ list_empty(&rcu_torture_freelist),
+ atomic_read(&n_rcu_torture_alloc),
+ atomic_read(&n_rcu_torture_alloc_fail),
+ atomic_read(&n_rcu_torture_free));
+ pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
+ atomic_read(&n_rcu_torture_mberror),
+ n_rcu_torture_barrier_error,
+ n_rcu_torture_boost_ktrerror,
+ n_rcu_torture_boost_rterror);
+ pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
+ n_rcu_torture_boost_failure,
+ n_rcu_torture_boosts,
+ atomic_long_read(&n_rcu_torture_timers));
+ torture_onoff_stats();
+ pr_cont("barrier: %ld/%ld:%ld ",
+ n_barrier_successes,
+ n_barrier_attempts,
+ n_rcu_torture_barrier_error);
+ pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods));
+
+ 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 ||
+ i > 1) {
+ pr_cont("%s", "!!! ");
+ atomic_inc(&n_rcu_torture_error);
+ WARN_ON_ONCE(1);
+ }
+ pr_cont("Reader Pipe: ");
+ for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
+ pr_cont(" %ld", pipesummary[i]);
+ pr_cont("\n");
+
+ pr_alert("%s%s ", torture_type, TORTURE_FLAG);
+ pr_cont("Reader Batch: ");
+ for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
+ pr_cont(" %ld", batchsummary[i]);
+ pr_cont("\n");
+
+ pr_alert("%s%s ", torture_type, TORTURE_FLAG);
+ pr_cont("Free-Block Circulation: ");
+ for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
+ pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
+ }
+ pr_cont("\n");
+
+ if (cur_ops->stats)
+ cur_ops->stats();
+ if (rtcv_snap == rcu_torture_current_version &&
+ rcu_torture_current != NULL) {
+ int __maybe_unused flags = 0;
+ unsigned long __maybe_unused gp_seq = 0;
+
+ rcutorture_get_gp_data(cur_ops->ttype,
+ &flags, &gp_seq);
+ srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
+ &flags, &gp_seq);
+ wtp = READ_ONCE(writer_task);
+ pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#lx cpu %d\n",
+ rcu_torture_writer_state_getname(),
+ rcu_torture_writer_state, gp_seq, flags,
+ wtp == NULL ? ~0UL : wtp->state,
+ wtp == NULL ? -1 : (int)task_cpu(wtp));
+ if (!splatted && wtp) {
+ sched_show_task(wtp);
+ splatted = true;
+ }
+ show_rcu_gp_kthreads();
+ rcu_ftrace_dump(DUMP_ALL);
+ }
+ rtcv_snap = rcu_torture_current_version;
+}
+
+/*
+ * Periodically prints torture statistics, if periodic statistics printing
+ * was specified via the stat_interval module parameter.
+ */
+static int
+rcu_torture_stats(void *arg)
+{
+ VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
+ do {
+ schedule_timeout_interruptible(stat_interval * HZ);
+ rcu_torture_stats_print();
+ torture_shutdown_absorb("rcu_torture_stats");
+ } while (!torture_must_stop());
+ torture_kthread_stopping("rcu_torture_stats");
+ return 0;
+}
+
+static void
+rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
+{
+ pr_alert("%s" TORTURE_FLAG
+ "--- %s: nreaders=%d nfakewriters=%d "
+ "stat_interval=%d verbose=%d test_no_idle_hz=%d "
+ "shuffle_interval=%d stutter=%d irqreader=%d "
+ "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
+ "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 "
+ "n_barrier_cbs=%d "
+ "onoff_interval=%d onoff_holdoff=%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,
+ n_barrier_cbs,
+ onoff_interval, onoff_holdoff);
+}
+
+static int rcutorture_booster_cleanup(unsigned int cpu)
+{
+ struct task_struct *t;
+
+ if (boost_tasks[cpu] == NULL)
+ return 0;
+ mutex_lock(&boost_mutex);
+ t = boost_tasks[cpu];
+ boost_tasks[cpu] = NULL;
+ rcu_torture_enable_rt_throttle();
+ mutex_unlock(&boost_mutex);
+
+ /* This must be outside of the mutex, otherwise deadlock! */
+ torture_stop_kthread(rcu_torture_boost, t);
+ return 0;
+}
+
+static int rcutorture_booster_init(unsigned int cpu)
+{
+ int retval;
+
+ if (boost_tasks[cpu] != NULL)
+ return 0; /* Already created, nothing more to do. */
+
+ /* Don't allow time recalculation while creating a new task. */
+ mutex_lock(&boost_mutex);
+ rcu_torture_disable_rt_throttle();
+ VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
+ boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
+ cpu_to_node(cpu),
+ "rcu_torture_boost");
+ if (IS_ERR(boost_tasks[cpu])) {
+ retval = PTR_ERR(boost_tasks[cpu]);
+ VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
+ n_rcu_torture_boost_ktrerror++;
+ boost_tasks[cpu] = NULL;
+ mutex_unlock(&boost_mutex);
+ return retval;
+ }
+ kthread_bind(boost_tasks[cpu], cpu);
+ wake_up_process(boost_tasks[cpu]);
+ mutex_unlock(&boost_mutex);
+ return 0;
+}
+
+/*
+ * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
+ * induces a CPU stall for the time specified by stall_cpu.
+ */
+static int rcu_torture_stall(void *args)
+{
+ unsigned long stop_at;
+
+ VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
+ if (stall_cpu_holdoff > 0) {
+ VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
+ schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
+ VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
+ }
+ if (!kthread_should_stop()) {
+ stop_at = ktime_get_seconds() + stall_cpu;
+ /* RCU CPU stall is expected behavior in following code. */
+ rcu_read_lock();
+ if (stall_cpu_irqsoff)
+ local_irq_disable();
+ else
+ preempt_disable();
+ pr_alert("rcu_torture_stall start on CPU %d.\n",
+ smp_processor_id());
+ while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
+ stop_at))
+ continue; /* Induce RCU CPU stall warning. */
+ if (stall_cpu_irqsoff)
+ local_irq_enable();
+ else
+ preempt_enable();
+ rcu_read_unlock();
+ pr_alert("rcu_torture_stall end.\n");
+ }
+ torture_shutdown_absorb("rcu_torture_stall");
+ while (!kthread_should_stop())
+ schedule_timeout_interruptible(10 * HZ);
+ return 0;
+}
+
+/* Spawn CPU-stall kthread, if stall_cpu specified. */
+static int __init rcu_torture_stall_init(void)
+{
+ if (stall_cpu <= 0)
+ return 0;
+ return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
+}
+
+/* Callback function for RCU barrier testing. */
+static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
+{
+ atomic_inc(&barrier_cbs_invoked);
+}
+
+/* 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 newphase;
+ struct rcu_head rcu;
+
+ init_rcu_head_on_stack(&rcu);
+ VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
+ set_user_nice(current, MAX_NICE);
+ do {
+ wait_event(barrier_cbs_wq[myid],
+ (newphase =
+ smp_load_acquire(&barrier_phase)) != lastphase ||
+ torture_must_stop());
+ lastphase = newphase;
+ if (torture_must_stop())
+ break;
+ /*
+ * 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 (atomic_dec_and_test(&barrier_cbs_count))
+ wake_up(&barrier_wq);
+ } while (!torture_must_stop());
+ if (cur_ops->cb_barrier != NULL)
+ cur_ops->cb_barrier();
+ destroy_rcu_head_on_stack(&rcu);
+ torture_kthread_stopping("rcu_torture_barrier_cbs");
+ return 0;
+}
+
+/* kthread function to drive and coordinate RCU barrier testing. */
+static int rcu_torture_barrier(void *arg)
+{
+ int i;
+
+ VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
+ do {
+ atomic_set(&barrier_cbs_invoked, 0);
+ atomic_set(&barrier_cbs_count, n_barrier_cbs);
+ /* Ensure barrier_phase ordered after prior assignments. */
+ smp_store_release(&barrier_phase, !barrier_phase);
+ for (i = 0; i < n_barrier_cbs; i++)
+ wake_up(&barrier_cbs_wq[i]);
+ wait_event(barrier_wq,
+ atomic_read(&barrier_cbs_count) == 0 ||
+ torture_must_stop());
+ if (torture_must_stop())
+ break;
+ n_barrier_attempts++;
+ cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
+ if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
+ n_rcu_torture_barrier_error++;
+ pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
+ atomic_read(&barrier_cbs_invoked),
+ n_barrier_cbs);
+ WARN_ON_ONCE(1);
+ } else {
+ n_barrier_successes++;
+ }
+ schedule_timeout_interruptible(HZ / 10);
+ } while (!torture_must_stop());
+ torture_kthread_stopping("rcu_torture_barrier");
+ return 0;
+}
+
+/* Initialize RCU barrier testing. */
+static int rcu_torture_barrier_init(void)
+{
+ int i;
+ int ret;
+
+ if (n_barrier_cbs <= 0)
+ return 0;
+ if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
+ pr_alert("%s" TORTURE_FLAG
+ " Call or barrier ops missing for %s,\n",
+ torture_type, cur_ops->name);
+ pr_alert("%s" TORTURE_FLAG
+ " RCU barrier testing omitted from run.\n",
+ torture_type);
+ return 0;
+ }
+ atomic_set(&barrier_cbs_count, 0);
+ atomic_set(&barrier_cbs_invoked, 0);
+ barrier_cbs_tasks =
+ kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]),
+ GFP_KERNEL);
+ barrier_cbs_wq =
+ kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL);
+ if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
+ return -ENOMEM;
+ for (i = 0; i < n_barrier_cbs; i++) {
+ init_waitqueue_head(&barrier_cbs_wq[i]);
+ ret = torture_create_kthread(rcu_torture_barrier_cbs,
+ (void *)(long)i,
+ barrier_cbs_tasks[i]);
+ if (ret)
+ return ret;
+ }
+ return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
+}
+
+/* Clean up after RCU barrier testing. */
+static void rcu_torture_barrier_cleanup(void)
+{
+ int i;
+
+ torture_stop_kthread(rcu_torture_barrier, barrier_task);
+ if (barrier_cbs_tasks != NULL) {
+ for (i = 0; i < n_barrier_cbs; i++)
+ torture_stop_kthread(rcu_torture_barrier_cbs,
+ barrier_cbs_tasks[i]);
+ kfree(barrier_cbs_tasks);
+ barrier_cbs_tasks = NULL;
+ }
+ if (barrier_cbs_wq != NULL) {
+ kfree(barrier_cbs_wq);
+ barrier_cbs_wq = NULL;
+ }
+}
+
+static bool rcu_torture_can_boost(void)
+{
+ static int boost_warn_once;
+ int prio;
+
+ if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2)
+ return false;
+
+ prio = rcu_get_gp_kthreads_prio();
+ if (!prio)
+ return false;
+
+ if (prio < 2) {
+ if (boost_warn_once == 1)
+ return false;
+
+ pr_alert("%s: WARN: RCU kthread priority too low to test boosting. Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME);
+ boost_warn_once = 1;
+ return false;
+ }
+
+ return true;
+}
+
+static enum cpuhp_state rcutor_hp;
+
+static void
+rcu_torture_cleanup(void)
+{
+ int flags = 0;
+ unsigned long gp_seq = 0;
+ int i;
+
+ if (torture_cleanup_begin()) {
+ if (cur_ops->cb_barrier != NULL)
+ cur_ops->cb_barrier();
+ return;
+ }
+
+ rcu_torture_barrier_cleanup();
+ torture_stop_kthread(rcu_torture_stall, stall_task);
+ torture_stop_kthread(rcu_torture_writer, writer_task);
+
+ if (reader_tasks) {
+ for (i = 0; i < nrealreaders; i++)
+ torture_stop_kthread(rcu_torture_reader,
+ reader_tasks[i]);
+ kfree(reader_tasks);
+ }
+ rcu_torture_current = NULL;
+
+ if (fakewriter_tasks) {
+ for (i = 0; i < nfakewriters; i++) {
+ torture_stop_kthread(rcu_torture_fakewriter,
+ fakewriter_tasks[i]);
+ }
+ kfree(fakewriter_tasks);
+ fakewriter_tasks = NULL;
+ }
+
+ 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);
+ torture_stop_kthread(rcu_torture_stats, stats_task);
+ torture_stop_kthread(rcu_torture_fqs, fqs_task);
+ for (i = 0; i < ncbflooders; i++)
+ torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
+ if (rcu_torture_can_boost())
+ cpuhp_remove_state(rcutor_hp);
+
+ /*
+ * Wait for all RCU callbacks to fire, then do flavor-specific
+ * cleanup operations.
+ */
+ if (cur_ops->cb_barrier != NULL)
+ cur_ops->cb_barrier();
+ if (cur_ops->cleanup != NULL)
+ cur_ops->cleanup();
+
+ rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
+
+ if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
+ rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
+ else if (torture_onoff_failures())
+ rcu_torture_print_module_parms(cur_ops,
+ "End of test: RCU_HOTPLUG");
+ else
+ rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
+ torture_cleanup_end();
+}
+
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+static void rcu_torture_leak_cb(struct rcu_head *rhp)
+{
+}
+
+static void rcu_torture_err_cb(struct rcu_head *rhp)
+{
+ /*
+ * This -might- happen due to race conditions, but is unlikely.
+ * The scenario that leads to this happening is that the
+ * first of the pair of duplicate callbacks is queued,
+ * someone else starts a grace period that includes that
+ * callback, then the second of the pair must wait for the
+ * next grace period. Unlikely, but can happen. If it
+ * does happen, the debug-objects subsystem won't have splatted.
+ */
+ pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME);
+}
+#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+
+/*
+ * Verify that double-free causes debug-objects to complain, but only
+ * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
+ * cannot be carried out.
+ */
+static void rcu_test_debug_objects(void)
+{
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+ struct rcu_head rh1;
+ struct rcu_head rh2;
+
+ init_rcu_head_on_stack(&rh1);
+ init_rcu_head_on_stack(&rh2);
+ pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME);
+
+ /* Try to queue the rh2 pair of callbacks for the same grace period. */
+ preempt_disable(); /* Prevent preemption from interrupting test. */
+ rcu_read_lock(); /* Make it impossible to finish a grace period. */
+ call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
+ local_irq_disable(); /* Make it harder to start a new grace period. */
+ call_rcu(&rh2, rcu_torture_leak_cb);
+ call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
+ local_irq_enable();
+ rcu_read_unlock();
+ preempt_enable();
+
+ /* Wait for them all to get done so we can safely return. */
+ rcu_barrier();
+ pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
+ destroy_rcu_head_on_stack(&rh1);
+ destroy_rcu_head_on_stack(&rh2);
+#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+ pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
+#endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+}
+
+static int __init
+rcu_torture_init(void)
+{
+ int i;
+ int cpu;
+ int firsterr = 0;
+ static struct rcu_torture_ops *torture_ops[] = {
+ &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
+ &busted_srcud_ops, &sched_ops, &tasks_ops,
+ };
+
+ if (!torture_init_begin(torture_type, verbose))
+ return -EBUSY;
+
+ /* Process args and tell the world that the torturer is on the job. */
+ for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
+ cur_ops = torture_ops[i];
+ if (strcmp(torture_type, cur_ops->name) == 0)
+ break;
+ }
+ if (i == ARRAY_SIZE(torture_ops)) {
+ pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
+ torture_type);
+ pr_alert("rcu-torture types:");
+ for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
+ pr_cont(" %s", torture_ops[i]->name);
+ pr_cont("\n");
+ firsterr = -EINVAL;
+ goto unwind;
+ }
+ if (cur_ops->fqs == NULL && fqs_duration != 0) {
+ pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
+ fqs_duration = 0;
+ }
+ if (cur_ops->init)
+ cur_ops->init();
+
+ if (nreaders >= 0) {
+ nrealreaders = nreaders;
+ } else {
+ nrealreaders = num_online_cpus() - 2 - nreaders;
+ if (nrealreaders <= 0)
+ nrealreaders = 1;
+ }
+ rcu_torture_print_module_parms(cur_ops, "Start of test");
+
+ /* Set up the freelist. */
+
+ INIT_LIST_HEAD(&rcu_torture_freelist);
+ for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
+ rcu_tortures[i].rtort_mbtest = 0;
+ list_add_tail(&rcu_tortures[i].rtort_free,
+ &rcu_torture_freelist);
+ }
+
+ /* Initialize the statistics so that each run gets its own numbers. */
+
+ rcu_torture_current = NULL;
+ rcu_torture_current_version = 0;
+ atomic_set(&n_rcu_torture_alloc, 0);
+ atomic_set(&n_rcu_torture_alloc_fail, 0);
+ atomic_set(&n_rcu_torture_free, 0);
+ atomic_set(&n_rcu_torture_mberror, 0);
+ atomic_set(&n_rcu_torture_error, 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;
+ n_rcu_torture_boosts = 0;
+ for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
+ atomic_set(&rcu_torture_wcount[i], 0);
+ for_each_possible_cpu(cpu) {
+ for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
+ per_cpu(rcu_torture_count, cpu)[i] = 0;
+ per_cpu(rcu_torture_batch, cpu)[i] = 0;
+ }
+ }
+
+ /* Start up the kthreads. */
+
+ firsterr = torture_create_kthread(rcu_torture_writer, NULL,
+ writer_task);
+ if (firsterr)
+ goto unwind;
+ if (nfakewriters > 0) {
+ fakewriter_tasks = kcalloc(nfakewriters,
+ sizeof(fakewriter_tasks[0]),
+ GFP_KERNEL);
+ if (fakewriter_tasks == NULL) {
+ VERBOSE_TOROUT_ERRSTRING("out of memory");
+ firsterr = -ENOMEM;
+ goto unwind;
+ }
+ }
+ for (i = 0; i < nfakewriters; i++) {
+ firsterr = torture_create_kthread(rcu_torture_fakewriter,
+ NULL, fakewriter_tasks[i]);
+ if (firsterr)
+ goto unwind;
+ }
+ reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
+ GFP_KERNEL);
+ if (reader_tasks == NULL) {
+ VERBOSE_TOROUT_ERRSTRING("out of memory");
+ firsterr = -ENOMEM;
+ goto unwind;
+ }
+ for (i = 0; i < nrealreaders; i++) {
+ firsterr = torture_create_kthread(rcu_torture_reader, NULL,
+ reader_tasks[i]);
+ if (firsterr)
+ goto unwind;
+ }
+ if (stat_interval > 0) {
+ firsterr = torture_create_kthread(rcu_torture_stats, NULL,
+ stats_task);
+ if (firsterr)
+ goto unwind;
+ }
+ if (test_no_idle_hz && shuffle_interval > 0) {
+ firsterr = torture_shuffle_init(shuffle_interval * HZ);
+ if (firsterr)
+ goto unwind;
+ }
+ if (stutter < 0)
+ stutter = 0;
+ if (stutter) {
+ firsterr = torture_stutter_init(stutter * HZ);
+ if (firsterr)
+ goto unwind;
+ }
+ if (fqs_duration < 0)
+ fqs_duration = 0;
+ if (fqs_duration) {
+ /* Create the fqs thread */
+ firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
+ fqs_task);
+ if (firsterr)
+ goto unwind;
+ }
+ if (test_boost_interval < 1)
+ test_boost_interval = 1;
+ if (test_boost_duration < 2)
+ test_boost_duration = 2;
+ if (rcu_torture_can_boost()) {
+
+ boost_starttime = jiffies + test_boost_interval * HZ;
+
+ firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
+ rcutorture_booster_init,
+ rcutorture_booster_cleanup);
+ if (firsterr < 0)
+ goto unwind;
+ rcutor_hp = firsterr;
+ }
+ firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
+ if (firsterr)
+ goto unwind;
+ firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval);
+ if (firsterr)
+ goto unwind;
+ firsterr = rcu_torture_stall_init();
+ if (firsterr)
+ goto unwind;
+ firsterr = rcu_torture_barrier_init();
+ if (firsterr)
+ goto unwind;
+ if (object_debug)
+ rcu_test_debug_objects();
+ if (cbflood_n_burst > 0) {
+ /* Create the cbflood threads */
+ ncbflooders = (num_online_cpus() + 3) / 4;
+ cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task),
+ GFP_KERNEL);
+ if (!cbflood_task) {
+ VERBOSE_TOROUT_ERRSTRING("out of memory");
+ firsterr = -ENOMEM;
+ goto unwind;
+ }
+ for (i = 0; i < ncbflooders; i++) {
+ firsterr = torture_create_kthread(rcu_torture_cbflood,
+ NULL,
+ cbflood_task[i]);
+ if (firsterr)
+ goto unwind;
+ }
+ }
+ torture_init_end();
+ return 0;
+
+unwind:
+ torture_init_end();
+ rcu_torture_cleanup();
+ return firsterr;
+}
+
+module_init(rcu_torture_init);
+module_exit(rcu_torture_cleanup);