Commit-ID: 6050cb0b0b366092d1383bc23d7b16cd26db00f0 Gitweb: http://git.kernel.org/tip/6050cb0b0b366092d1383bc23d7b16cd26db00f0 Author: Frederic Weisbecker <fweisbec@xxxxxxxxx> AuthorDate: Tue, 23 Jul 2013 02:30:59 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 30 Jul 2013 22:22:58 +0200 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@xxxxxxxxxxxxx> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1374539466-4799-2-git-send-email-fweisbec@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/events/core.c | 12 ++++++------ 1 file 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; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html