diff options
| -rw-r--r-- | mm/kmemleak.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 8a57e34625fa..c0fd7769d227 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -53,6 +53,11 @@ * modifications to the memory scanning parameters including the scan_thread * pointer * + * Locks and mutexes should only be acquired/nested in the following order: + * + * scan_mutex -> object->lock -> other_object->lock (SINGLE_DEPTH_NESTING) + * -> kmemleak_lock + * * The kmemleak_object structures have a use_count incremented or decremented * using the get_object()/put_object() functions. When the use_count becomes * 0, this count can no longer be incremented and put_object() schedules the @@ -603,11 +608,13 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size, kmemleak_stop("Cannot insert 0x%lx into the object " "search tree (overlaps existing)\n", ptr); + /* + * No need for parent->lock here since "parent" cannot + * be freed while the kmemleak_lock is held. + */ + dump_object_info(parent); kmem_cache_free(object_cache, object); - object = parent; - spin_lock(&object->lock); - dump_object_info(object); - spin_unlock(&object->lock); + object = NULL; goto out; } } |