perf cgroup: Fix unmatched call to perf_detach_cgroup()

Li Zefan · Ingo Molnar · commit f75e18cb9627 · 2011-03-04T11:32:51.000+01:00
In the failure path, we call perf_detach_cgroup(), but we didn't
call perf_get_cgroup() prio to it.

Signed-off-by: Li Zefan &lt;lizf@cn.fujitsu.com&gt;
Acked-by: Stephane Eranian &lt;eranian@google.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
LKML-Reference: &lt;4D6F346E.9070606@cn.fujitsu.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
@@ -412,6 +412,9 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 	cgrp = container_of(css, struct perf_cgroup, css);
 	event->cgrp = cgrp;
 
+	/* must be done before we fput() the file */
+	perf_get_cgroup(event);
+
 	/*
 	 * all events in a group must monitor
 	 * the same cgroup because a task belongs
@@ -420,9 +423,6 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 	if (group_leader && group_leader->cgrp != cgrp) {
 		perf_detach_cgroup(event);
 		ret = -EINVAL;
-	} else {
-		/* must be done before we fput() the file */
-		perf_get_cgroup(event);
 	}
 out:
 	fput_light(file, fput_needed);
