watchdog: fix double lock in watchdog_nmi_enable_all

Michal Hocko · torvalds · commit 1173ff09b9c5 · 2015-05-19T10:57:03.000-07:00
Commit ab992dc ("watchdog: Fix merge 'conflict'") has introduced an obvious deadlock because of a typo. watchdog_proc_mutex should be unlocked on exit. Thanks to Miroslav Benes who was staring at the code with me and noticed this. Signed-off-by: Michal Hocko <mhocko@suse.cz> Duh-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
@@ -621,7 +621,7 @@ void watchdog_nmi_enable_all(void)
 	put_online_cpus();
 
 unlock:
-	mutex_lock(&watchdog_proc_mutex);
+	mutex_unlock(&watchdog_proc_mutex);
 }
 
 void watchdog_nmi_disable_all(void)

Original file line number	Diff line number	Diff line change
`@@ -621,7 +621,7 @@ void watchdog_nmi_enable_all(void)`
`621`	`621`	`put_online_cpus();`
`622`	`622`
`623`	`623`	`unlock:`
`624`		`- mutex_lock(&watchdog_proc_mutex);`
	`624`	`+ mutex_unlock(&watchdog_proc_mutex);`
`625`	`625`	`}`
`626`	`626`
`627`	`627`	`void watchdog_nmi_disable_all(void)`