From a33caeb118198286309859f014c0662f3ed54ed4 Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Wed, 9 Nov 2011 16:04:51 +0800 Subject: lockdep, kmemcheck: Annotate ->lock in lockdep_init_map() Since commit f59de89 ("lockdep: Clear whole lockdep_map on initialization"), lockdep_init_map() will clear all the struct. But it will break lock_set_class()/lock_set_subclass(). A typical race condition is like below: CPU A CPU B lock_set_subclass(lockA); lock_set_class(lockA); lockdep_init_map(lockA); /* lockA->name is cleared */ memset(lockA); __lock_acquire(lockA); /* lockA->class_cache[] is cleared */ register_lock_class(lockA); look_up_lock_class(lockA); WARN_ON_ONCE(class->name != lock->name); lock->name = name; So restore to what we have done before commit f59de89 but annotate ->lock with kmemcheck_mark_initialized() to suppress the kmemcheck warning reported in commit f59de89. Reported-by: Sergey Senozhatsky Reported-by: Borislav Petkov Suggested-by: Vegard Nossum Signed-off-by: Yong Zhang Cc: Tejun Heo Cc: David Rientjes Cc: Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20111109080451.GB8124@zhy Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index e69434b070da..b2e08c932d91 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -44,6 +44,7 @@ #include #include #include +#include #include @@ -2948,7 +2949,12 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, void lockdep_init_map(struct lockdep_map *lock, const char *name, struct lock_class_key *key, int subclass) { - memset(lock, 0, sizeof(*lock)); + int i; + + kmemcheck_mark_initialized(lock, sizeof(*lock)); + + for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++) + lock->class_cache[i] = NULL; #ifdef CONFIG_LOCK_STAT lock->cpu = raw_smp_processor_id(); -- cgit v1.2.3 From 86b47c25494b824da655b95f6fdb4fdb3f17aa77 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Tue, 22 Nov 2011 16:08:21 +0200 Subject: perf: Do no try to schedule task events if there are none perf_event_sched_in() shouldn't try to schedule task events if there are none otherwise task's ctx->is_active will be set and will not be cleared during sched_out. This will prevent newly added events from being scheduled into the task context. Fixes a boo-boo in commit 1d5f003f5a9 ("perf: Do not set task_ctx pointer in cpuctx if there are no events in the context"). Signed-off-by: Gleb Natapov Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20111122140821.GF2557@redhat.com Signed-off-by: Ingo Molnar --- kernel/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/events/core.c b/kernel/events/core.c index 600c1629b64d..d3b9df5962c2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2174,11 +2174,11 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx, */ cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); - perf_event_sched_in(cpuctx, ctx, task); - if (ctx->nr_events) cpuctx->task_ctx = ctx; + perf_event_sched_in(cpuctx, cpuctx->task_ctx, task); + perf_pmu_enable(ctx->pmu); perf_ctx_unlock(cpuctx, ctx); -- cgit v1.2.3