Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 4344381..53534aa 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1,21 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Kernel Probes (KProbes)
* kernel/kprobes.c
*
- * 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
* Copyright (C) IBM Corporation, 2002, 2004
*
* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
@@ -229,7 +216,7 @@
struct kprobe_insn_page *kip, *next;
/* Ensure no-one is interrupted on the garbages */
- synchronize_sched();
+ synchronize_rcu();
list_for_each_entry_safe(kip, next, &c->pages, list) {
int i;
@@ -483,6 +470,7 @@
*/
static void do_optimize_kprobes(void)
{
+ lockdep_assert_held(&text_mutex);
/*
* The optimization/unoptimization refers online_cpus via
* stop_machine() and cpu-hotplug modifies online_cpus.
@@ -500,9 +488,7 @@
list_empty(&optimizing_list))
return;
- mutex_lock(&text_mutex);
arch_optimize_kprobes(&optimizing_list);
- mutex_unlock(&text_mutex);
}
/*
@@ -513,6 +499,7 @@
{
struct optimized_kprobe *op, *tmp;
+ lockdep_assert_held(&text_mutex);
/* See comment in do_optimize_kprobes() */
lockdep_assert_cpus_held();
@@ -520,7 +507,6 @@
if (list_empty(&unoptimizing_list))
return;
- mutex_lock(&text_mutex);
arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list);
/* Loop free_list for disarming */
list_for_each_entry_safe(op, tmp, &freeing_list, list) {
@@ -537,7 +523,6 @@
} else
list_del_init(&op->list);
}
- mutex_unlock(&text_mutex);
}
/* Reclaim all kprobes on the free_list */
@@ -546,8 +531,14 @@
struct optimized_kprobe *op, *tmp;
list_for_each_entry_safe(op, tmp, &freeing_list, list) {
- BUG_ON(!kprobe_unused(&op->kp));
list_del_init(&op->list);
+ if (WARN_ON_ONCE(!kprobe_unused(&op->kp))) {
+ /*
+ * This must not happen, but if there is a kprobe
+ * still in use, keep it on kprobes hash list.
+ */
+ continue;
+ }
free_aggr_kprobe(&op->kp);
}
}
@@ -563,6 +554,7 @@
{
mutex_lock(&kprobe_mutex);
cpus_read_lock();
+ mutex_lock(&text_mutex);
/* Lock modules while optimizing kprobes */
mutex_lock(&module_mutex);
@@ -590,6 +582,7 @@
do_free_cleaned_kprobes();
mutex_unlock(&module_mutex);
+ mutex_unlock(&text_mutex);
cpus_read_unlock();
mutex_unlock(&kprobe_mutex);
@@ -703,9 +696,7 @@
static int reuse_unused_kprobe(struct kprobe *ap)
{
struct optimized_kprobe *op;
- int ret;
- BUG_ON(!kprobe_unused(ap));
/*
* Unused kprobe MUST be on the way of delayed unoptimizing (means
* there is still a relative jump) and disabled.
@@ -715,9 +706,8 @@
/* Enable the probe again */
ap->flags &= ~KPROBE_FLAG_DISABLED;
/* Optimize it again (remove from op->list) */
- ret = kprobe_optready(ap);
- if (ret)
- return ret;
+ if (!kprobe_optready(ap))
+ return -EINVAL;
optimize_kprobe(ap);
return 0;
@@ -972,8 +962,15 @@
#ifdef CONFIG_KPROBES_ON_FTRACE
static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {
.func = kprobe_ftrace_handler,
+ .flags = FTRACE_OPS_FL_SAVE_REGS,
+};
+
+static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = {
+ .func = kprobe_ftrace_handler,
.flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY,
};
+
+static int kprobe_ipmodify_enabled;
static int kprobe_ftrace_enabled;
/* Must ensure p->addr is really on ftrace */
@@ -986,58 +983,75 @@
}
/* Caller must lock kprobe_mutex */
-static int arm_kprobe_ftrace(struct kprobe *p)
+static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
+ int *cnt)
{
int ret = 0;
- ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
- (unsigned long)p->addr, 0, 0);
+ ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0);
if (ret) {
pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n",
p->addr, ret);
return ret;
}
- if (kprobe_ftrace_enabled == 0) {
- ret = register_ftrace_function(&kprobe_ftrace_ops);
+ if (*cnt == 0) {
+ ret = register_ftrace_function(ops);
if (ret) {
pr_debug("Failed to init kprobe-ftrace (%d)\n", ret);
goto err_ftrace;
}
}
- kprobe_ftrace_enabled++;
+ (*cnt)++;
return ret;
err_ftrace:
/*
- * Note: Since kprobe_ftrace_ops has IPMODIFY set, and ftrace requires a
- * non-empty filter_hash for IPMODIFY ops, we're safe from an accidental
- * empty filter_hash which would undesirably trace all functions.
+ * At this point, sinec ops is not registered, we should be sefe from
+ * registering empty filter.
*/
- ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 1, 0);
+ ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0);
return ret;
}
+static int arm_kprobe_ftrace(struct kprobe *p)
+{
+ bool ipmodify = (p->post_handler != NULL);
+
+ return __arm_kprobe_ftrace(p,
+ ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops,
+ ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
+}
+
/* Caller must lock kprobe_mutex */
-static int disarm_kprobe_ftrace(struct kprobe *p)
+static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
+ int *cnt)
{
int ret = 0;
- if (kprobe_ftrace_enabled == 1) {
- ret = unregister_ftrace_function(&kprobe_ftrace_ops);
+ if (*cnt == 1) {
+ ret = unregister_ftrace_function(ops);
if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret))
return ret;
}
- kprobe_ftrace_enabled--;
+ (*cnt)--;
- ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
- (unsigned long)p->addr, 1, 0);
+ ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0);
WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n",
p->addr, ret);
return ret;
}
+
+static int disarm_kprobe_ftrace(struct kprobe *p)
+{
+ bool ipmodify = (p->post_handler != NULL);
+
+ return __disarm_kprobe_ftrace(p,
+ ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops,
+ ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
+}
#else /* !CONFIG_KPROBES_ON_FTRACE */
#define prepare_kprobe(p) arch_prepare_kprobe(p)
#define arm_kprobe_ftrace(p) (-ENODEV)
@@ -1269,8 +1283,6 @@
/* Add the new probe to ap->list */
static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
{
- BUG_ON(kprobe_gone(ap) || kprobe_gone(p));
-
if (p->post_handler)
unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */
@@ -1379,7 +1391,7 @@
if (ret) {
ap->flags |= KPROBE_FLAG_DISABLED;
list_del_rcu(&p->list);
- synchronize_sched();
+ synchronize_rcu();
}
}
}
@@ -1393,7 +1405,7 @@
addr < (unsigned long)__kprobes_text_end;
}
-bool within_kprobe_blacklist(unsigned long addr)
+static bool __within_kprobe_blacklist(unsigned long addr)
{
struct kprobe_blacklist_entry *ent;
@@ -1407,7 +1419,26 @@
if (addr >= ent->start_addr && addr < ent->end_addr)
return true;
}
+ return false;
+}
+bool within_kprobe_blacklist(unsigned long addr)
+{
+ char symname[KSYM_NAME_LEN], *p;
+
+ if (__within_kprobe_blacklist(addr))
+ return true;
+
+ /* Check if the address is on a suffixed-symbol */
+ if (!lookup_symbol_name(addr, symname)) {
+ p = strchr(symname, '.');
+ if (!p)
+ return false;
+ *p = '\0';
+ addr = (unsigned long)kprobe_lookup_name(symname, 0);
+ if (addr)
+ return __within_kprobe_blacklist(addr);
+ }
return false;
}
@@ -1507,7 +1538,8 @@
/* Ensure it is not in reserved area nor out of text */
if (!kernel_text_address((unsigned long) p->addr) ||
within_kprobe_blacklist((unsigned long) p->addr) ||
- jump_label_text_reserved(p->addr, p->addr)) {
+ jump_label_text_reserved(p->addr, p->addr) ||
+ find_bug((unsigned long)p->addr)) {
ret = -EINVAL;
goto out;
}
@@ -1594,7 +1626,7 @@
ret = arm_kprobe(p);
if (ret) {
hlist_del_rcu(&p->hlist);
- synchronize_sched();
+ synchronize_rcu();
goto out;
}
}
@@ -1717,7 +1749,6 @@
return 0;
disarmed:
- BUG_ON(!kprobe_disarmed(ap));
hlist_del_rcu(&ap->hlist);
return 0;
}
@@ -1774,7 +1805,7 @@
kps[i]->addr = NULL;
mutex_unlock(&kprobe_mutex);
- synchronize_sched();
+ synchronize_rcu();
for (i = 0; i < num; i++)
if (kps[i]->addr)
__unregister_kprobe_bottom(kps[i]);
@@ -1900,7 +1931,7 @@
/* Pre-allocate memory for max kretprobe instances */
if (rp->maxactive <= 0) {
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus());
#else
rp->maxactive = num_possible_cpus();
@@ -1964,7 +1995,7 @@
rps[i]->kp.addr = NULL;
mutex_unlock(&kprobe_mutex);
- synchronize_sched();
+ synchronize_rcu();
for (i = 0; i < num; i++) {
if (rps[i]->kp.addr) {
__unregister_kprobe_bottom(&rps[i]->kp);
@@ -2091,6 +2122,47 @@
}
NOKPROBE_SYMBOL(dump_kprobe);
+int kprobe_add_ksym_blacklist(unsigned long entry)
+{
+ struct kprobe_blacklist_entry *ent;
+ unsigned long offset = 0, size = 0;
+
+ if (!kernel_text_address(entry) ||
+ !kallsyms_lookup_size_offset(entry, &size, &offset))
+ return -EINVAL;
+
+ ent = kmalloc(sizeof(*ent), GFP_KERNEL);
+ if (!ent)
+ return -ENOMEM;
+ ent->start_addr = entry;
+ ent->end_addr = entry + size;
+ INIT_LIST_HEAD(&ent->list);
+ list_add_tail(&ent->list, &kprobe_blacklist);
+
+ return (int)size;
+}
+
+/* Add all symbols in given area into kprobe blacklist */
+int kprobe_add_area_blacklist(unsigned long start, unsigned long end)
+{
+ unsigned long entry;
+ int ret = 0;
+
+ for (entry = start; entry < end; entry += ret) {
+ ret = kprobe_add_ksym_blacklist(entry);
+ if (ret < 0)
+ return ret;
+ if (ret == 0) /* In case of alias symbol */
+ ret = 1;
+ }
+ return 0;
+}
+
+int __init __weak arch_populate_kprobe_blacklist(void)
+{
+ return 0;
+}
+
/*
* Lookup and populate the kprobe_blacklist.
*
@@ -2102,26 +2174,24 @@
static int __init populate_kprobe_blacklist(unsigned long *start,
unsigned long *end)
{
+ unsigned long entry;
unsigned long *iter;
- struct kprobe_blacklist_entry *ent;
- unsigned long entry, offset = 0, size = 0;
+ int ret;
for (iter = start; iter < end; iter++) {
entry = arch_deref_entry_point((void *)*iter);
-
- if (!kernel_text_address(entry) ||
- !kallsyms_lookup_size_offset(entry, &size, &offset))
+ ret = kprobe_add_ksym_blacklist(entry);
+ if (ret == -EINVAL)
continue;
-
- ent = kmalloc(sizeof(*ent), GFP_KERNEL);
- if (!ent)
- return -ENOMEM;
- ent->start_addr = entry;
- ent->end_addr = entry + size;
- INIT_LIST_HEAD(&ent->list);
- list_add_tail(&ent->list, &kprobe_blacklist);
+ if (ret < 0)
+ return ret;
}
- return 0;
+
+ /* Symbols in __kprobes_text are blacklisted */
+ ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start,
+ (unsigned long)__kprobes_text_end);
+
+ return ret ? : arch_populate_kprobe_blacklist();
}
/* Module notifier call back, checking kprobes on the module */
@@ -2231,6 +2301,7 @@
init_test_probes();
return err;
}
+subsys_initcall(init_kprobes);
#ifdef CONFIG_DEBUG_FS
static void report_probe(struct seq_file *pi, struct kprobe *p,
@@ -2525,36 +2596,21 @@
static int __init debugfs_kprobe_init(void)
{
- struct dentry *dir, *file;
+ struct dentry *dir;
unsigned int value = 1;
dir = debugfs_create_dir("kprobes", NULL);
- if (!dir)
- return -ENOMEM;
- file = debugfs_create_file("list", 0400, dir, NULL,
- &debugfs_kprobes_operations);
- if (!file)
- goto error;
+ debugfs_create_file("list", 0400, dir, NULL,
+ &debugfs_kprobes_operations);
- file = debugfs_create_file("enabled", 0600, dir,
- &value, &fops_kp);
- if (!file)
- goto error;
+ debugfs_create_file("enabled", 0600, dir, &value, &fops_kp);
- file = debugfs_create_file("blacklist", 0400, dir, NULL,
- &debugfs_kprobe_blacklist_ops);
- if (!file)
- goto error;
+ debugfs_create_file("blacklist", 0400, dir, NULL,
+ &debugfs_kprobe_blacklist_ops);
return 0;
-
-error:
- debugfs_remove(dir);
- return -ENOMEM;
}
late_initcall(debugfs_kprobe_init);
#endif /* CONFIG_DEBUG_FS */
-
-module_init(init_kprobes);