[PATCH 19/27] 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.

Signed-off-by: Bart Van Assche <bvanass...@acm.org>
---
 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 fc10302d34fd..4610f3c4f3db 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4145,10 +4145,8 @@ 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.rc0.387.gc7a69e6b6c-goog