[PATCH v4 -next 2/2] watchdog/hardlockup/perf: Warn if watchdog_ev is overwritten

[Li Huafei <lihuafei1@huawei.com>]

When we create a new perf_event, it should not happen that the old
perf_event is not released. If it does, make a warning to sense the
problem in time.

Signed-off-by: Li Huafei <lihuafei1@huawei.com>
---
 kernel/watchdog_perf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/watchdog_perf.c b/kernel/watchdog_perf.c
index 2fdb96eaf493..09236586b8c3 100644
--- a/kernel/watchdog_perf.c
+++ b/kernel/watchdog_perf.c
@@ -144,6 +144,7 @@ static int hardlockup_detector_event_create(void)
 			 PTR_ERR(evt));
 		return PTR_ERR(evt);
 	}
+	WARN_ON(this_cpu_read(watchdog_ev));
 	this_cpu_write(watchdog_ev, evt);
 	return 0;
 }
-- 
2.25.1