1 /* SPDX-License-Identifier: GPL-2.0 */
8  * see Documentation/locking/lockdep-design.rst for more details.
41 		to->class_cache[i] = NULL;  in lockdep_copy_map()
45  * Every lock has a list of other locks that were taken after it.
56 	/* used by BFS to record whether "prev -> this" only has -(*R)-> */
60 	 * The parent field is used to implement breadth-first search, and the
61 	 * bit 0 is reused to indicate if the lock has been accessed in BFS.
67  * struct lock_chain - lock dependency chain record
72  * @entry:       the collided lock chains in lock_chain hash list
87 #define INITIAL_CHAIN_KEY		-1
91 	 * One-way hash of the dependency chain up to this point. We
94 	 * We use it for dependency-caching and we skip detection
95 	 * passes and dependency-updates if there is a cache-hit, so
99 	 * as likely as possible - hence the 64-bit width.
113 	 * class_idx is zero-indexed; it points to the element in
114 	 * lock_classes this held lock instance belongs to. class_idx is in
115 	 * the range from 0 to (MAX_LOCKDEP_KEYS-1) inclusive.
119 	 * The lock-stack is unified in that the lock chains of interrupt
122 	 * context, and we also keep do not add cross-context lock
123 	 * dependencies - the lock usage graph walking covers that area
131 	unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
142  * Initialization, self-test and debugging-output methods:
146 extern void lockdep_reset_lock(struct lockdep_map *lock);
158 #define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)
167 	current->lockdep_recursion += LOCKDEP_OFF;	\
172 	current->lockdep_recursion -= LOCKDEP_OFF;	\
184 extern void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
188 lockdep_init_map_waits(struct lockdep_map *lock, const char *name,  in lockdep_init_map_waits()  argument
191 	lockdep_init_map_type(lock, name, key, subclass, inner, outer, LD_LOCK_NORMAL);  in lockdep_init_map_waits()
195 lockdep_init_map_wait(struct lockdep_map *lock, const char *name,  in lockdep_init_map_wait()  argument
198 	lockdep_init_map_waits(lock, name, key, subclass, inner, LD_WAIT_INV);  in lockdep_init_map_wait()
201 static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,  in lockdep_init_map()  argument
204 	lockdep_init_map_wait(lock, name, key, subclass, LD_WAIT_INV);  in lockdep_init_map()
208  * Reinitialize a lock key - for cases where there is special locking or
210  * of dependencies wrong: they are either too broad (they need a class-split)
211  * or they are too narrow (they suffer from a false class-split):
213 #define lockdep_set_class(lock, key)				\  argument
214 	lockdep_init_map_type(&(lock)->dep_map, #key, key, 0,	\
215 			      (lock)->dep_map.wait_type_inner,	\
216 			      (lock)->dep_map.wait_type_outer,	\
217 			      (lock)->dep_map.lock_type)
219 #define lockdep_set_class_and_name(lock, key, name)		\  argument
220 	lockdep_init_map_type(&(lock)->dep_map, name, key, 0,	\
221 			      (lock)->dep_map.wait_type_inner,	\
222 			      (lock)->dep_map.wait_type_outer,	\
223 			      (lock)->dep_map.lock_type)
225 #define lockdep_set_class_and_subclass(lock, key, sub)		\  argument
226 	lockdep_init_map_type(&(lock)->dep_map, #key, key, sub,	\
227 			      (lock)->dep_map.wait_type_inner,	\
228 			      (lock)->dep_map.wait_type_outer,	\
229 			      (lock)->dep_map.lock_type)
231 #define lockdep_set_subclass(lock, sub)					\  argument
232 	lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
233 			      (lock)->dep_map.wait_type_inner,		\
234 			      (lock)->dep_map.wait_type_outer,		\
235 			      (lock)->dep_map.lock_type)
237 #define lockdep_set_novalidate_class(lock) \  argument
238 	lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
243 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)  argument
245 static inline int lockdep_match_key(struct lockdep_map *lock,  in lockdep_match_key()  argument
248 	return lock->key == key;  in lockdep_match_key()
252  * Acquire a lock.
257  *   1: read-acquire (no recursion allowed)
258  *   2: read-acquire with same-instance recursion allowed
262  *   0: simple checks (freeing, held-at-exit-time, etc.)
265 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
269 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
272 #define LOCK_STATE_UNKNOWN	-1
277  * Same "read" as for lock_acquire(), except -1 means any.
279 extern int lock_is_held_type(const struct lockdep_map *lock, int read);
281 static inline int lock_is_held(const struct lockdep_map *lock)  in lock_is_held()  argument
283 	return lock_is_held_type(lock, -1);  in lock_is_held()
286 #define lockdep_is_held(lock)		lock_is_held(&(lock)->dep_map)  argument
287 #define lockdep_is_held_type(lock, r)	lock_is_held_type(&(lock)->dep_map, (r))  argument
289 extern void lock_set_class(struct lockdep_map *lock, const char *name,
296 static inline void lock_set_subclass(struct lockdep_map *lock,  in lock_set_subclass()  argument
299 	lock_set_class(lock, lock->name, lock->key, subclass, ip);  in lock_set_subclass()
302 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
306 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
307 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
308 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
310 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
334 	lockdep_assert_once(!current->lockdep_depth)
336 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
338 #define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
339 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
340 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
367 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \  argument
369 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \  argument
371 # define lockdep_init_map_wait(lock, name, key, sub, inner) \  argument
373 # define lockdep_init_map(lock, name, key, sub) \  argument
375 # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)  argument
376 # define lockdep_set_class_and_name(lock, key, name) \  argument
378 #define lockdep_set_class_and_subclass(lock, key, sub) \  argument
380 #define lockdep_set_subclass(lock, sub)		do { } while (0)  argument
382 #define lockdep_set_novalidate_class(lock) do { } while (0)  argument
405  * Dummy forward declarations, allow users to write less ifdef-y code
451 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
452 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
454 #define LOCK_CONTENDED(_lock, try, lock)			\  argument
457 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
458 		lock(_lock);					\
460 	lock_acquired(&(_lock)->dep_map, _RET_IP_);			\
463 #define LOCK_CONTENDED_RETURN(_lock, try, lock)			\  argument
467 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
468 		____err = lock(_lock);				\
471 		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
480 #define LOCK_CONTENDED(_lock, try, lock) \  argument
481 	lock(_lock)
483 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \  argument
484 	lock(_lock)
511  * For trivial one-depth nesting of a lock-class, the following
513  * of nesting should define their own lock-nesting subclasses.)
519  * on the per lock-class debug mode:
560 # define might_lock(lock)						\  argument
562 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
563 	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
564 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
566 # define might_lock_read(lock)						\  argument
568 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
569 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
570 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
572 # define might_lock_nested(lock, subclass)				\  argument
574 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
575 	lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,		\
577 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
618  * Acceptable for protecting per-CPU resources accessed from BH.
619  * Much like in_softirq() - semantics are ambiguous, use carefully.
628 # define might_lock(lock) do { } while (0)  argument
629 # define might_lock_read(lock) do { } while (0)  argument
630 # define might_lock_nested(lock, subclass) do { } while (0)  argument
644 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
646 			  !(current->hardirq_threaded || current->irq_config),	\