perf: Fix context leak in put_event()

Commit:

  a83fe28e2e45 ("perf: Fix put_event() ctx lock")

changed the locking logic in put_event() by replacing mutex_lock_nested()
with perf_event_ctx_lock_nested(), but didn't fix the subsequent
mutex_unlock() with a correct counterpart, perf_event_ctx_unlock().

Contexts are thus leaked as a result of incremented refcount
in perf_event_ctx_lock_nested().

Signed-off-by: Leon Yu <chianglungyu@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: a83fe28e2e45 ("perf: Fix put_event() ctx lock")
Link: http://lkml.kernel.org/r/1424954613-5034-1-git-send-email-chianglungyu@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f04daabfd1cf..453ef61311d4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3591,7 +3591,7 @@ static void put_event(struct perf_event *event)
         ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING);
         WARN_ON_ONCE(ctx->parent_ctx);
         perf_remove_from_context(event, true);
-        mutex_unlock(&ctx->mutex);
+        perf_event_ctx_unlock(event, ctx);
 
         _free_event(event);
 }