diff options
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/lockdep.c | 76 |
1 files changed, 43 insertions, 33 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index ef27f98714c0..95932333a48b 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -138,6 +138,9 @@ static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; * get freed - this significantly simplifies the debugging code. */ unsigned long nr_lock_classes; +#ifndef CONFIG_DEBUG_LOCKDEP +static +#endif struct lock_class lock_classes[MAX_LOCKDEP_KEYS]; static inline struct lock_class *hlock_class(struct held_lock *hlock) @@ -626,7 +629,8 @@ static int static_obj(void *obj) /* * To make lock name printouts unique, we calculate a unique - * class->name_version generation counter: + * class->name_version generation counter. The caller must hold the graph + * lock. */ static int count_matching_names(struct lock_class *new_class) { @@ -636,7 +640,7 @@ static int count_matching_names(struct lock_class *new_class) if (!new_class->name) return 0; - list_for_each_entry_rcu(class, &all_lock_classes, lock_entry) { + list_for_each_entry(class, &all_lock_classes, lock_entry) { if (new_class->key - new_class->subclass == class->key) return class->name_version; if (class->name && !strcmp(class->name, new_class->name)) @@ -789,7 +793,6 @@ 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->lock_entry); INIT_LIST_HEAD(&class->locks_before); INIT_LIST_HEAD(&class->locks_after); class->name_version = count_matching_names(class); @@ -801,7 +804,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) /* * Add it to the global list of classes: */ - list_add_tail_rcu(&class->lock_entry, &all_lock_classes); + list_add_tail(&class->lock_entry, &all_lock_classes); if (verbose(class)) { graph_unlock(); @@ -3088,7 +3091,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, /* * Initialize a lock instance's lock-class mapping info: */ -static void __lockdep_init_map(struct lockdep_map *lock, const char *name, +void lockdep_init_map(struct lockdep_map *lock, const char *name, struct lock_class_key *key, int subclass) { int i; @@ -3144,12 +3147,6 @@ static void __lockdep_init_map(struct lockdep_map *lock, const char *name, raw_local_irq_restore(flags); } } - -void lockdep_init_map(struct lockdep_map *lock, const char *name, - struct lock_class_key *key, int subclass) -{ - __lockdep_init_map(lock, name, key, subclass); -} EXPORT_SYMBOL_GPL(lockdep_init_map); struct lock_class_key __lockdep_no_validate__; @@ -4126,6 +4123,9 @@ void lockdep_reset(void) raw_local_irq_restore(flags); } +/* + * Remove all references to a lock class. The caller must hold the graph lock. + */ static void zap_class(struct lock_class *class) { int i; @@ -4142,7 +4142,7 @@ 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); - list_del_rcu(&class->lock_entry); + list_del(&class->lock_entry); RCU_INIT_POINTER(class->key, NULL); RCU_INIT_POINTER(class->name, NULL); @@ -4204,15 +4204,36 @@ void lockdep_free_key_range(void *start, unsigned long size) */ } -void lockdep_reset_lock(struct lockdep_map *lock) +/* + * Check whether any element of the @lock->class_cache[] array refers to a + * registered lock class. The caller must hold either the graph lock or the + * RCU read lock. + */ +static bool lock_class_cache_is_registered(struct lockdep_map *lock) { struct lock_class *class; struct hlist_head *head; - unsigned long flags; int i, j; - int locked; + + for (i = 0; i < CLASSHASH_SIZE; i++) { + head = classhash_table + i; + hlist_for_each_entry_rcu(class, head, hash_entry) { + for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++) + if (lock->class_cache[j] == class) + return true; + } + } + return false; +} + +void lockdep_reset_lock(struct lockdep_map *lock) +{ + struct lock_class *class; + unsigned long flags; + int j, locked; raw_local_irq_save(flags); + locked = graph_lock(); /* * Remove all classes this lock might have: @@ -4229,25 +4250,14 @@ void lockdep_reset_lock(struct lockdep_map *lock) * Debug check: in the end all mapped classes should * be gone. */ - locked = graph_lock(); - for (i = 0; i < CLASSHASH_SIZE; i++) { - head = classhash_table + i; - hlist_for_each_entry_rcu(class, head, hash_entry) { - int match = 0; - - for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++) - match |= class == lock->class_cache[j]; - - if (unlikely(match)) { - if (debug_locks_off_graph_unlock()) { - /* - * We all just reset everything, how did it match? - */ - WARN_ON(1); - } - goto out_restore; - } + if (unlikely(lock_class_cache_is_registered(lock))) { + if (debug_locks_off_graph_unlock()) { + /* + * We all just reset everything, how did it match? + */ + WARN_ON(1); } + goto out_restore; } if (locked) graph_unlock(); |