perf_events: Fix resource leak in x86 __hw_perf_event_init()

If reserve_pmc_hardware() succeeds but reserve_ds_buffers()
fails, then we need to release_pmc_hardware. It won't be done
by the destroy() callback because we return before setting it
in case of error.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: <stable@kernel.org>
Cc: peterz@infradead.org
Cc: paulus@samba.org
Cc: davem@davemloft.net
Cc: fweisbec@gmail.com
Cc: robert.richter@amd.com
Cc: perfmon2-devel@lists.sf.net
LKML-Reference: <4ba1568b.15185e0a.182a.7802@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
--
 arch/x86/kernel/cpu/perf_event.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 14eca80918dc..f571f514de2a 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -455,8 +455,11 @@ static int __hw_perf_event_init(struct perf_event *event)
                 if (atomic_read(&active_events) == 0) {
                         if (!reserve_pmc_hardware())
                                 err = -EBUSY;
-                        else
+                        else {
                                 err = reserve_ds_buffers();
+                                if (err)
+                                        release_pmc_hardware();
+                        }
                 }
                 if (!err)
                         atomic_inc(&active_events);