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

Commit ca0dd44c authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf/core: Fix perf_event_read_value() locking 



perf_event_read_value() is an external accessor, just like
perf_event_{en,dis}able() and should thus use perf_event_ctx_lock().

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f63a8daa ("perf: Fix event->ctx locking")
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 7d9285e8

kernel/events/core.c

+14 −2
Original line number Original line Diff line number Diff line
@@ -4398,7 +4398,7 @@ static int perf_release(struct inode *inode, struct file *file) 
	return 0;

	return 0;

}

}





u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)

static u64 __perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)

{

{

	struct perf_event *child;

	struct perf_event *child;

	u64 total = 0;

	u64 total = 0;
@@ -4426,6 +4426,18 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) 




	return total;

	return total;

}

}



u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)

{

	struct perf_event_context *ctx;

	u64 count;



	ctx = perf_event_ctx_lock(event);

	count = __perf_event_read_value(event, enabled, running);

	perf_event_ctx_unlock(event, ctx);



	return count;

}

EXPORT_SYMBOL_GPL(perf_event_read_value);

EXPORT_SYMBOL_GPL(perf_event_read_value);





static int __perf_read_group_add(struct perf_event *leader,

static int __perf_read_group_add(struct perf_event *leader,
@@ -4528,7 +4540,7 @@ static int perf_read_one(struct perf_event *event, 
	u64 values[4];

	u64 values[4];

	int n = 0;

	int n = 0;





	values[n++] = perf_event_read_value(event, &enabled, &running);

	values[n++] = __perf_event_read_value(event, &enabled, &running);

	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)

	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)

		values[n++] = enabled;

		values[n++] = enabled;

	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)

	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)