mm: kmemleak: do not acquire scan_mutex in kmemleak_do_cleanup()

The kmemleak_do_cleanup() work thread already waits for the kmemleak_scan thread to finish via kthread_stop(). Waiting in kthread_stop() while scan_mutex is held may lead to deadlock if kmemleak_scan_thread() also waits to acquire for scan_mutex. Signed-off-by: Catalin Marinas <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
modi0012 · Jun 25, 2015 · 5f369f3 · 5f369f3
1 parent e781a9a
commit 5f369f3
Showing 1 changed file with 0 additions and 2 deletions.
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
@@ -1762,7 +1762,6 @@ static void __kmemleak_do_cleanup(void)
  */
 static void kmemleak_do_cleanup(struct work_struct *work)
 {
-	mutex_lock(&scan_mutex);
 	stop_scan_thread();
 
 	/*
@@ -1777,7 +1776,6 @@ static void kmemleak_do_cleanup(struct work_struct *work)
 	else
 		pr_info("Kmemleak disabled without freeing internal data. "
 			"Reclaim the memory with \"echo clear > /sys/kernel/debug/kmemleak\"\n");
-	mutex_unlock(&scan_mutex);
 }
 
 static DECLARE_WORK(cleanup_work, kmemleak_do_cleanup);