diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2017-09-05 13:38:24 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-10 13:40:40 +0100 |
| commit | 4ee9572b109de66357a73e27effed5266a449183 (patch) | |
| tree | 70a1878700a7b2cdb61910fdc8e6a36885ed3d62 /kernel/events | |
| parent | 9851961159b6d33b7523e73cdedf156204a731bd (diff) | |
perf/core: Fix __perf_read_group_add() locking
[ Upstream commit a9cd8194e1e6bd09619954721dfaf0f94fe2003e ]
Event timestamps are serialized using ctx->lock, make sure to hold it
over reading all values.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 10cdb9c26b5d..4f1d4bfc607a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4433,6 +4433,8 @@ static int __perf_read_group_add(struct perf_event *leader, if (ret) return ret; + raw_spin_lock_irqsave(&ctx->lock, flags); + /* * Since we co-schedule groups, {enabled,running} times of siblings * will be identical to those of the leader, so we only publish one @@ -4455,8 +4457,6 @@ static int __perf_read_group_add(struct perf_event *leader, if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(leader); - raw_spin_lock_irqsave(&ctx->lock, flags); - list_for_each_entry(sub, &leader->sibling_list, group_entry) { values[n++] += perf_event_count(sub); if (read_format & PERF_FORMAT_ID) |