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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2013-07-23 02:30:59 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-07-30 22:22:58 +0200 |
| commit | 6050cb0b0b366092d1383bc23d7b16cd26db00f0 (patch) | |
| tree | e29edecc20a04e17aa4c7f83d21a140d3e377356 /kernel | |
| parent | 7d9ffa8961482232d964173cccba6e14d2d543b2 (diff) | |
| download | op-kernel-dev-6050cb0b0b366092d1383bc23d7b16cd26db00f0.zip op-kernel-dev-6050cb0b0b366092d1383bc23d7b16cd26db00f0.tar.gz | |
perf: Fix branch stack refcount leak on callchain init failure
On callchain buffers allocation failure, free_event() is
called and all the accounting performed in perf_event_alloc()
for that event is cancelled.
But if the event has branch stack sampling, it is unaccounted
as well from the branch stack sampling events refcounts.
This is a bug because this accounting is performed after the
callchain buffer allocation. As a result, the branch stack sampling
events refcount can become negative.
To fix this, move the branch stack event accounting before the
callchain buffer allocation.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1374539466-4799-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 1274114..f35aa7e 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6567,6 +6567,12 @@ done: atomic_inc(&nr_comm_events); if (event->attr.task) atomic_inc(&nr_task_events); + if (has_branch_stack(event)) { + static_key_slow_inc(&perf_sched_events.key); + if (!(event->attach_state & PERF_ATTACH_TASK)) + atomic_inc(&per_cpu(perf_branch_stack_events, + event->cpu)); + } if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { err = get_callchain_buffers(); if (err) { @@ -6574,12 +6580,6 @@ done: return ERR_PTR(err); } } - if (has_branch_stack(event)) { - static_key_slow_inc(&perf_sched_events.key); - if (!(event->attach_state & PERF_ATTACH_TASK)) - atomic_inc(&per_cpu(perf_branch_stack_events, - event->cpu)); - } } return event; |
