diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 28fbeb2a10cc..d1a6daf1f51f 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -735,6 +735,25 @@ static bool assign_lock_key(struct lockdep_map *lock) return true; } +/* + * Initialize the lock_classes[] array elements. + */ +static void init_data_structures_once(void) +{ + static bool initialization_happened; + int i; + + if (likely(initialization_happened)) + return; + + initialization_happened = true; + + for (i = 0; i < ARRAY_SIZE(lock_classes); i++) { + INIT_LIST_HEAD(&lock_classes[i].locks_after); + INIT_LIST_HEAD(&lock_classes[i].locks_before); + } +} + /* * Register a lock's class in the hash-table, if the class is not present * yet. Otherwise we look it up. We cache the result in the lock object @@ -775,6 +794,8 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) goto out_unlock_set; } + init_data_structures_once(); + /* * Allocate a new key from the static array, and add it to * the hash: @@ -793,8 +814,8 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) class->key = key; class->name = lock->name; class->subclass = subclass; - INIT_LIST_HEAD(&class->locks_before); - INIT_LIST_HEAD(&class->locks_after); + WARN_ON_ONCE(!list_empty(&class->locks_before)); + WARN_ON_ONCE(!list_empty(&class->locks_after)); class->name_version = count_matching_names(class); /* * We use RCU's safe list-add method to make @@ -4155,6 +4176,8 @@ void lockdep_free_key_range(void *start, unsigned long size) int i; int locked; + init_data_structures_once(); + raw_local_irq_save(flags); locked = graph_lock(); @@ -4218,6 +4241,8 @@ void lockdep_reset_lock(struct lockdep_map *lock) unsigned long flags; int j, locked; + init_data_structures_once(); + raw_local_irq_save(flags); locked = graph_lock();