[PATCH v2 16/24] locking/lockdep: Retain the class key and name while freeing a lock class

[Bart Van Assche]

The next patch in this series uses the class name in code that
detects lock class use-after-free. Hence retain the class name for
lock classes that are being freed.

Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Waiman Long <longman@xxxxxxxxxx>
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 kernel/locking/lockdep.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index ecd92969674c..92bdb187987f 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4147,10 +4147,8 @@ static void zap_class(struct lock_class *class)
 	 * Unhash the class and remove it from the all_lock_classes list:
 	 */
 	hlist_del_rcu(&class->hash_entry);
+	class->hash_entry.pprev = NULL;
 	list_del(&class->lock_entry);
-
-	RCU_INIT_POINTER(class->key, NULL);
-	RCU_INIT_POINTER(class->name, NULL);
 }
 
 static inline int within(const void *addr, void *start, unsigned long size)
-- 
2.20.0.rc1.387.gf8505762e3-goog