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authorLinus Torvalds <torvalds@linux-foundation.org>2019-08-25 17:03:32 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2019-08-25 17:03:32 (GMT)
commit05bbb9360a000f509537a84554d69fb891fa7332 (patch)
tree3d603240fef76b6aa43823e202326202bb3b96d7
parent44c471e43698d966d2bf291a9631f7d22a861bbd (diff)
parentf1c6ece23729257fb46562ff9224cf5f61b818da (diff)
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Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner: "Two small fixes for kprobes and perf: - Prevent a deadlock in kprobe_optimizer() causes by reverse lock ordering - Fix a comment typo" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Fix potential deadlock in kprobe_optimizer() perf/x86: Fix typo in comment
-rw-r--r--arch/x86/events/core.c2
-rw-r--r--kernel/kprobes.c8
2 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 81b005e..325959d 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1236,7 +1236,7 @@ void x86_pmu_enable_event(struct perf_event *event)
* Add a single event to the PMU.
*
* The event is added to the group of enabled events
- * but only if it can be scehduled with existing events.
+ * but only if it can be scheduled with existing events.
*/
static int x86_pmu_add(struct perf_event *event, int flags)
{
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 9873fc6..d9770a53 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -470,6 +470,7 @@ static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
*/
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.
@@ -487,9 +488,7 @@ static void do_optimize_kprobes(void)
list_empty(&optimizing_list))
return;
- mutex_lock(&text_mutex);
arch_optimize_kprobes(&optimizing_list);
- mutex_unlock(&text_mutex);
}
/*
@@ -500,6 +499,7 @@ static void do_unoptimize_kprobes(void)
{
struct optimized_kprobe *op, *tmp;
+ lockdep_assert_held(&text_mutex);
/* See comment in do_optimize_kprobes() */
lockdep_assert_cpus_held();
@@ -507,7 +507,6 @@ static void do_unoptimize_kprobes(void)
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) {
@@ -524,7 +523,6 @@ static void do_unoptimize_kprobes(void)
} else
list_del_init(&op->list);
}
- mutex_unlock(&text_mutex);
}
/* Reclaim all kprobes on the free_list */
@@ -556,6 +554,7 @@ static void kprobe_optimizer(struct work_struct *work)
{
mutex_lock(&kprobe_mutex);
cpus_read_lock();
+ mutex_lock(&text_mutex);
/* Lock modules while optimizing kprobes */
mutex_lock(&module_mutex);
@@ -583,6 +582,7 @@ static void kprobe_optimizer(struct work_struct *work)
do_free_cleaned_kprobes();
mutex_unlock(&module_mutex);
+ mutex_unlock(&text_mutex);
cpus_read_unlock();
mutex_unlock(&kprobe_mutex);