Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 652884fe authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf: Add a bit of paranoia 



Add a few WARN()s to catch things that should never happen.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150123125834.150481799@infradead.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8f4bf4bc

kernel/events/core.c

+18 −1
Original line number Diff line number Diff line
@@ -1275,6 +1275,8 @@ static void perf_group_attach(struct perf_event *event) 
	if (group_leader == event)

		return;



	WARN_ON_ONCE(group_leader->ctx != event->ctx);



	if (group_leader->group_flags & PERF_GROUP_SOFTWARE &&

			!is_software_event(event))

		group_leader->group_flags &= ~PERF_GROUP_SOFTWARE;
@@ -1296,6 +1298,10 @@ static void 
list_del_event(struct perf_event *event, struct perf_event_context *ctx)

{

	struct perf_cpu_context *cpuctx;



	WARN_ON_ONCE(event->ctx != ctx);

	lockdep_assert_held(&ctx->lock);



	/*

	 * We can have double detach due to exit/hot-unplug + close.

	 */
@@ -1380,6 +1386,8 @@ static void perf_group_detach(struct perf_event *event) 


		/* Inherit group flags from the previous leader */

		sibling->group_flags = event->group_flags;



		WARN_ON_ONCE(sibling->ctx != event->ctx);

	}



out:
@@ -1442,6 +1450,10 @@ event_sched_out(struct perf_event *event, 
{

	u64 tstamp = perf_event_time(event);

	u64 delta;



	WARN_ON_ONCE(event->ctx != ctx);

	lockdep_assert_held(&ctx->lock);



	/*

	 * An event which could not be activated because of

	 * filter mismatch still needs to have its timings
@@ -7822,14 +7834,19 @@ static void perf_free_event(struct perf_event *event, 


	put_event(parent);



	raw_spin_lock_irq(&ctx->lock);

	perf_group_detach(event);

	list_del_event(event, ctx);

	raw_spin_unlock_irq(&ctx->lock);

	free_event(event);

}



/*

 * free an unexposed, unused context as created by inheritance by

 * Free an unexposed, unused context as created by inheritance by

 * perf_event_init_task below, used by fork() in case of fail.

 *

 * Not all locks are strictly required, but take them anyway to be nice and

 * help out with the lockdep assertions.

 */

void perf_event_free_task(struct task_struct *task)

{