Merge branch 'perf/urgent' into perf/core

Merge in all fixes before applying more changes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f85c0154b333..d7d71d6ec972 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -253,9 +253,9 @@ perf_cgroup_match(struct perf_event *event)
         return !event->cgrp || event->cgrp == cpuctx->cgrp;
 }
 
-static inline void perf_get_cgroup(struct perf_event *event)
+static inline bool perf_tryget_cgroup(struct perf_event *event)
 {
-        css_get(&event->cgrp->css);
+        return css_tryget(&event->cgrp->css);
 }
 
 static inline void perf_put_cgroup(struct perf_event *event)
@@ -484,7 +484,11 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
         event->cgrp = cgrp;
 
         /* must be done before we fput() the file */
-        perf_get_cgroup(event);
+        if (!perf_tryget_cgroup(event)) {
+                event->cgrp = NULL;
+                ret = -ENOENT;
+                goto out;
+        }
 
         /*
          * all events in a group must monitor