perf cgroup: Fix unmatched call to perf_detach_cgroup()

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 <lizf@cn.fujitsu.com>
Acked-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4D6F346E.9070606@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 7c999e809ba3e076a96aa76c2f5ce97e67419c92..b00209544d571fe2bcd76cb05e555b8464fb9e40 100644 (file)
--- 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);