xref: /linux-6.15/include/linux/lockdep.h (revision 2bc7ea71)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Runtime locking correctness validator
4  *
5  *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <[email protected]>
6  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
7  *
8  * see Documentation/locking/lockdep-design.rst for more details.
9  */
10 #ifndef __LINUX_LOCKDEP_H
11 #define __LINUX_LOCKDEP_H
12 
13 #include <linux/lockdep_types.h>
14 #include <linux/smp.h>
15 #include <asm/percpu.h>
16 
17 struct task_struct;
18 
19 #ifdef CONFIG_LOCKDEP
20 
21 #include <linux/linkage.h>
22 #include <linux/list.h>
23 #include <linux/debug_locks.h>
24 #include <linux/stacktrace.h>
25 
26 static inline void lockdep_copy_map(struct lockdep_map *to,
27 				    struct lockdep_map *from)
28 {
29 	int i;
30 
31 	*to = *from;
32 	/*
33 	 * Since the class cache can be modified concurrently we could observe
34 	 * half pointers (64bit arch using 32bit copy insns). Therefore clear
35 	 * the caches and take the performance hit.
36 	 *
37 	 * XXX it doesn't work well with lockdep_set_class_and_subclass(), since
38 	 *     that relies on cache abuse.
39 	 */
40 	for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
41 		to->class_cache[i] = NULL;
42 }
43 
44 /*
45  * Every lock has a list of other locks that were taken after it.
46  * We only grow the list, never remove from it:
47  */
48 struct lock_list {
49 	struct list_head		entry;
50 	struct lock_class		*class;
51 	struct lock_class		*links_to;
52 	const struct lock_trace		*trace;
53 	u16				distance;
54 	/* bitmap of different dependencies from head to this */
55 	u8				dep;
56 	/* used by BFS to record whether "prev -> this" only has -(*R)-> */
57 	u8				only_xr;
58 
59 	/*
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.
62 	 */
63 	struct lock_list		*parent;
64 };
65 
66 /**
67  * struct lock_chain - lock dependency chain record
68  *
69  * @irq_context: the same as irq_context in held_lock below
70  * @depth:       the number of held locks in this chain
71  * @base:        the index in chain_hlocks for this chain
72  * @entry:       the collided lock chains in lock_chain hash list
73  * @chain_key:   the hash key of this lock_chain
74  */
75 struct lock_chain {
76 	/* see BUILD_BUG_ON()s in add_chain_cache() */
77 	unsigned int			irq_context :  2,
78 					depth       :  6,
79 					base	    : 24;
80 	/* 4 byte hole */
81 	struct hlist_node		entry;
82 	u64				chain_key;
83 };
84 
85 #define MAX_LOCKDEP_KEYS_BITS		13
86 #define MAX_LOCKDEP_KEYS		(1UL << MAX_LOCKDEP_KEYS_BITS)
87 #define INITIAL_CHAIN_KEY		-1
88 
89 struct held_lock {
90 	/*
91 	 * One-way hash of the dependency chain up to this point. We
92 	 * hash the hashes step by step as the dependency chain grows.
93 	 *
94 	 * We use it for dependency-caching and we skip detection
95 	 * passes and dependency-updates if there is a cache-hit, so
96 	 * it is absolutely critical for 100% coverage of the validator
97 	 * to have a unique key value for every unique dependency path
98 	 * that can occur in the system, to make a unique hash value
99 	 * as likely as possible - hence the 64-bit width.
100 	 *
101 	 * The task struct holds the current hash value (initialized
102 	 * with zero), here we store the previous hash value:
103 	 */
104 	u64				prev_chain_key;
105 	unsigned long			acquire_ip;
106 	struct lockdep_map		*instance;
107 	struct lockdep_map		*nest_lock;
108 #ifdef CONFIG_LOCK_STAT
109 	u64 				waittime_stamp;
110 	u64				holdtime_stamp;
111 #endif
112 	/*
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.
116 	 */
117 	unsigned int			class_idx:MAX_LOCKDEP_KEYS_BITS;
118 	/*
119 	 * The lock-stack is unified in that the lock chains of interrupt
120 	 * contexts nest ontop of process context chains, but we 'separate'
121 	 * the hashes by starting with 0 if we cross into an interrupt
122 	 * context, and we also keep do not add cross-context lock
123 	 * dependencies - the lock usage graph walking covers that area
124 	 * anyway, and we'd just unnecessarily increase the number of
125 	 * dependencies otherwise. [Note: hardirq and softirq contexts
126 	 * are separated from each other too.]
127 	 *
128 	 * The following field is used to detect when we cross into an
129 	 * interrupt context:
130 	 */
131 	unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
132 	unsigned int trylock:1;						/* 16 bits */
133 
134 	unsigned int read:2;        /* see lock_acquire() comment */
135 	unsigned int check:1;       /* see lock_acquire() comment */
136 	unsigned int hardirqs_off:1;
137 	unsigned int references:12;					/* 32 bits */
138 	unsigned int pin_count;
139 };
140 
141 /*
142  * Initialization, self-test and debugging-output methods:
143  */
144 extern void lockdep_init(void);
145 extern void lockdep_reset(void);
146 extern void lockdep_reset_lock(struct lockdep_map *lock);
147 extern void lockdep_free_key_range(void *start, unsigned long size);
148 extern asmlinkage void lockdep_sys_exit(void);
149 extern void lockdep_set_selftest_task(struct task_struct *task);
150 
151 extern void lockdep_init_task(struct task_struct *task);
152 
153 /*
154  * Split the recursion counter in two to readily detect 'off' vs recursion.
155  */
156 #define LOCKDEP_RECURSION_BITS	16
157 #define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)
158 #define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)
159 
160 /*
161  * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due
162  * to header dependencies.
163  */
164 
165 #define lockdep_off()					\
166 do {							\
167 	current->lockdep_recursion += LOCKDEP_OFF;	\
168 } while (0)
169 
170 #define lockdep_on()					\
171 do {							\
172 	current->lockdep_recursion -= LOCKDEP_OFF;	\
173 } while (0)
174 
175 extern void lockdep_register_key(struct lock_class_key *key);
176 extern void lockdep_unregister_key(struct lock_class_key *key);
177 
178 /*
179  * These methods are used by specific locking variants (spinlocks,
180  * rwlocks, mutexes and rwsems) to pass init/acquire/release events
181  * to lockdep:
182  */
183 
184 extern void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
185 	struct lock_class_key *key, int subclass, u8 inner, u8 outer, u8 lock_type);
186 
187 static inline void
188 lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
189 		       struct lock_class_key *key, int subclass, u8 inner, u8 outer)
190 {
191 	lockdep_init_map_type(lock, name, key, subclass, inner, LD_WAIT_INV, LD_LOCK_NORMAL);
192 }
193 
194 static inline void
195 lockdep_init_map_wait(struct lockdep_map *lock, const char *name,
196 		      struct lock_class_key *key, int subclass, u8 inner)
197 {
198 	lockdep_init_map_waits(lock, name, key, subclass, inner, LD_WAIT_INV);
199 }
200 
201 static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,
202 			     struct lock_class_key *key, int subclass)
203 {
204 	lockdep_init_map_wait(lock, name, key, subclass, LD_WAIT_INV);
205 }
206 
207 /*
208  * Reinitialize a lock key - for cases where there is special locking or
209  * special initialization of locks so that the validator gets the scope
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):
212  */
213 #define lockdep_set_class(lock, key)				\
214 	lockdep_init_map_waits(&(lock)->dep_map, #key, key, 0,	\
215 			       (lock)->dep_map.wait_type_inner,	\
216 			       (lock)->dep_map.wait_type_outer)
217 
218 #define lockdep_set_class_and_name(lock, key, name)		\
219 	lockdep_init_map_waits(&(lock)->dep_map, name, key, 0,	\
220 			       (lock)->dep_map.wait_type_inner,	\
221 			       (lock)->dep_map.wait_type_outer)
222 
223 #define lockdep_set_class_and_subclass(lock, key, sub)		\
224 	lockdep_init_map_waits(&(lock)->dep_map, #key, key, sub,\
225 			       (lock)->dep_map.wait_type_inner,	\
226 			       (lock)->dep_map.wait_type_outer)
227 
228 #define lockdep_set_subclass(lock, sub)					\
229 	lockdep_init_map_waits(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
230 			       (lock)->dep_map.wait_type_inner,		\
231 			       (lock)->dep_map.wait_type_outer)
232 
233 #define lockdep_set_novalidate_class(lock) \
234 	lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
235 
236 /*
237  * Compare locking classes
238  */
239 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)
240 
241 static inline int lockdep_match_key(struct lockdep_map *lock,
242 				    struct lock_class_key *key)
243 {
244 	return lock->key == key;
245 }
246 
247 /*
248  * Acquire a lock.
249  *
250  * Values for "read":
251  *
252  *   0: exclusive (write) acquire
253  *   1: read-acquire (no recursion allowed)
254  *   2: read-acquire with same-instance recursion allowed
255  *
256  * Values for check:
257  *
258  *   0: simple checks (freeing, held-at-exit-time, etc.)
259  *   1: full validation
260  */
261 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
262 			 int trylock, int read, int check,
263 			 struct lockdep_map *nest_lock, unsigned long ip);
264 
265 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
266 
267 /* lock_is_held_type() returns */
268 #define LOCK_STATE_UNKNOWN	-1
269 #define LOCK_STATE_NOT_HELD	0
270 #define LOCK_STATE_HELD		1
271 
272 /*
273  * Same "read" as for lock_acquire(), except -1 means any.
274  */
275 extern int lock_is_held_type(const struct lockdep_map *lock, int read);
276 
277 static inline int lock_is_held(const struct lockdep_map *lock)
278 {
279 	return lock_is_held_type(lock, -1);
280 }
281 
282 #define lockdep_is_held(lock)		lock_is_held(&(lock)->dep_map)
283 #define lockdep_is_held_type(lock, r)	lock_is_held_type(&(lock)->dep_map, (r))
284 
285 extern void lock_set_class(struct lockdep_map *lock, const char *name,
286 			   struct lock_class_key *key, unsigned int subclass,
287 			   unsigned long ip);
288 
289 #define lock_set_novalidate_class(l, n, i) \
290 	lock_set_class(l, n, &__lockdep_no_validate__, 0, i)
291 
292 static inline void lock_set_subclass(struct lockdep_map *lock,
293 		unsigned int subclass, unsigned long ip)
294 {
295 	lock_set_class(lock, lock->name, lock->key, subclass, ip);
296 }
297 
298 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
299 
300 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
301 
302 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
303 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
304 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
305 
306 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
307 
308 #define lockdep_assert(cond)		\
309 	do { WARN_ON(debug_locks && !(cond)); } while (0)
310 
311 #define lockdep_assert_once(cond)	\
312 	do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
313 
314 #define lockdep_assert_held(l)		\
315 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
316 
317 #define lockdep_assert_not_held(l)	\
318 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
319 
320 #define lockdep_assert_held_write(l)	\
321 	lockdep_assert(lockdep_is_held_type(l, 0))
322 
323 #define lockdep_assert_held_read(l)	\
324 	lockdep_assert(lockdep_is_held_type(l, 1))
325 
326 #define lockdep_assert_held_once(l)		\
327 	lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
328 
329 #define lockdep_assert_none_held_once()		\
330 	lockdep_assert_once(!current->lockdep_depth)
331 
332 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
333 
334 #define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
335 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
336 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
337 
338 #else /* !CONFIG_LOCKDEP */
339 
340 static inline void lockdep_init_task(struct task_struct *task)
341 {
342 }
343 
344 static inline void lockdep_off(void)
345 {
346 }
347 
348 static inline void lockdep_on(void)
349 {
350 }
351 
352 static inline void lockdep_set_selftest_task(struct task_struct *task)
353 {
354 }
355 
356 # define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
357 # define lock_release(l, i)			do { } while (0)
358 # define lock_downgrade(l, i)			do { } while (0)
359 # define lock_set_class(l, n, key, s, i)	do { (void)(key); } while (0)
360 # define lock_set_novalidate_class(l, n, i)	do { } while (0)
361 # define lock_set_subclass(l, s, i)		do { } while (0)
362 # define lockdep_init()				do { } while (0)
363 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
364 		do { (void)(name); (void)(key); } while (0)
365 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
366 		do { (void)(name); (void)(key); } while (0)
367 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
368 		do { (void)(name); (void)(key); } while (0)
369 # define lockdep_init_map(lock, name, key, sub) \
370 		do { (void)(name); (void)(key); } while (0)
371 # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
372 # define lockdep_set_class_and_name(lock, key, name) \
373 		do { (void)(key); (void)(name); } while (0)
374 #define lockdep_set_class_and_subclass(lock, key, sub) \
375 		do { (void)(key); } while (0)
376 #define lockdep_set_subclass(lock, sub)		do { } while (0)
377 
378 #define lockdep_set_novalidate_class(lock) do { } while (0)
379 
380 /*
381  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
382  * case since the result is not well defined and the caller should rather
383  * #ifdef the call himself.
384  */
385 
386 # define lockdep_reset()		do { debug_locks = 1; } while (0)
387 # define lockdep_free_key_range(start, size)	do { } while (0)
388 # define lockdep_sys_exit() 			do { } while (0)
389 
390 static inline void lockdep_register_key(struct lock_class_key *key)
391 {
392 }
393 
394 static inline void lockdep_unregister_key(struct lock_class_key *key)
395 {
396 }
397 
398 #define lockdep_depth(tsk)	(0)
399 
400 /*
401  * Dummy forward declarations, allow users to write less ifdef-y code
402  * and depend on dead code elimination.
403  */
404 extern int lock_is_held(const void *);
405 extern int lockdep_is_held(const void *);
406 #define lockdep_is_held_type(l, r)		(1)
407 
408 #define lockdep_assert(c)			do { } while (0)
409 #define lockdep_assert_once(c)			do { } while (0)
410 
411 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
412 #define lockdep_assert_not_held(l)		do { (void)(l); } while (0)
413 #define lockdep_assert_held_write(l)		do { (void)(l); } while (0)
414 #define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
415 #define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
416 #define lockdep_assert_none_held_once()	do { } while (0)
417 
418 #define lockdep_recursing(tsk)			(0)
419 
420 #define NIL_COOKIE (struct pin_cookie){ }
421 
422 #define lockdep_pin_lock(l)			({ struct pin_cookie cookie = { }; cookie; })
423 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
424 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
425 
426 #endif /* !LOCKDEP */
427 
428 enum xhlock_context_t {
429 	XHLOCK_HARD,
430 	XHLOCK_SOFT,
431 	XHLOCK_CTX_NR,
432 };
433 
434 #define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
435 /*
436  * To initialize a lockdep_map statically use this macro.
437  * Note that _name must not be NULL.
438  */
439 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
440 	{ .name = (_name), .key = (void *)(_key), }
441 
442 static inline void lockdep_invariant_state(bool force) {}
443 static inline void lockdep_free_task(struct task_struct *task) {}
444 
445 #ifdef CONFIG_LOCK_STAT
446 
447 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
448 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
449 
450 #define LOCK_CONTENDED(_lock, try, lock)			\
451 do {								\
452 	if (!try(_lock)) {					\
453 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
454 		lock(_lock);					\
455 	}							\
456 	lock_acquired(&(_lock)->dep_map, _RET_IP_);			\
457 } while (0)
458 
459 #define LOCK_CONTENDED_RETURN(_lock, try, lock)			\
460 ({								\
461 	int ____err = 0;					\
462 	if (!try(_lock)) {					\
463 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
464 		____err = lock(_lock);				\
465 	}							\
466 	if (!____err)						\
467 		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
468 	____err;						\
469 })
470 
471 #else /* CONFIG_LOCK_STAT */
472 
473 #define lock_contended(lockdep_map, ip) do {} while (0)
474 #define lock_acquired(lockdep_map, ip) do {} while (0)
475 
476 #define LOCK_CONTENDED(_lock, try, lock) \
477 	lock(_lock)
478 
479 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
480 	lock(_lock)
481 
482 #endif /* CONFIG_LOCK_STAT */
483 
484 #ifdef CONFIG_PROVE_LOCKING
485 extern void print_irqtrace_events(struct task_struct *curr);
486 #else
487 static inline void print_irqtrace_events(struct task_struct *curr)
488 {
489 }
490 #endif
491 
492 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
493 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
494 extern unsigned int force_read_lock_recursive;
495 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
496 #define force_read_lock_recursive 0
497 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
498 
499 #ifdef CONFIG_LOCKDEP
500 extern bool read_lock_is_recursive(void);
501 #else /* CONFIG_LOCKDEP */
502 /* If !LOCKDEP, the value is meaningless */
503 #define read_lock_is_recursive() 0
504 #endif
505 
506 /*
507  * For trivial one-depth nesting of a lock-class, the following
508  * global define can be used. (Subsystems with multiple levels
509  * of nesting should define their own lock-nesting subclasses.)
510  */
511 #define SINGLE_DEPTH_NESTING			1
512 
513 /*
514  * Map the dependency ops to NOP or to real lockdep ops, depending
515  * on the per lock-class debug mode:
516  */
517 
518 #define lock_acquire_exclusive(l, s, t, n, i)		lock_acquire(l, s, t, 0, 1, n, i)
519 #define lock_acquire_shared(l, s, t, n, i)		lock_acquire(l, s, t, 1, 1, n, i)
520 #define lock_acquire_shared_recursive(l, s, t, n, i)	lock_acquire(l, s, t, 2, 1, n, i)
521 
522 #define spin_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
523 #define spin_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
524 #define spin_release(l, i)			lock_release(l, i)
525 
526 #define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
527 #define rwlock_acquire_read(l, s, t, i)					\
528 do {									\
529 	if (read_lock_is_recursive())					\
530 		lock_acquire_shared_recursive(l, s, t, NULL, i);	\
531 	else								\
532 		lock_acquire_shared(l, s, t, NULL, i);			\
533 } while (0)
534 
535 #define rwlock_release(l, i)			lock_release(l, i)
536 
537 #define seqcount_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
538 #define seqcount_acquire_read(l, s, t, i)	lock_acquire_shared_recursive(l, s, t, NULL, i)
539 #define seqcount_release(l, i)			lock_release(l, i)
540 
541 #define mutex_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
542 #define mutex_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
543 #define mutex_release(l, i)			lock_release(l, i)
544 
545 #define rwsem_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
546 #define rwsem_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
547 #define rwsem_acquire_read(l, s, t, i)		lock_acquire_shared(l, s, t, NULL, i)
548 #define rwsem_release(l, i)			lock_release(l, i)
549 
550 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
551 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
552 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
553 #define lock_map_release(l)			lock_release(l, _THIS_IP_)
554 
555 #ifdef CONFIG_PROVE_LOCKING
556 # define might_lock(lock)						\
557 do {									\
558 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
559 	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
560 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
561 } while (0)
562 # define might_lock_read(lock)						\
563 do {									\
564 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
565 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
566 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
567 } while (0)
568 # define might_lock_nested(lock, subclass)				\
569 do {									\
570 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
571 	lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,		\
572 		     _THIS_IP_);					\
573 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
574 } while (0)
575 
576 DECLARE_PER_CPU(int, hardirqs_enabled);
577 DECLARE_PER_CPU(int, hardirq_context);
578 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
579 
580 #define __lockdep_enabled	(debug_locks && !this_cpu_read(lockdep_recursion))
581 
582 #define lockdep_assert_irqs_enabled()					\
583 do {									\
584 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
585 } while (0)
586 
587 #define lockdep_assert_irqs_disabled()					\
588 do {									\
589 	WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
590 } while (0)
591 
592 #define lockdep_assert_in_irq()						\
593 do {									\
594 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
595 } while (0)
596 
597 #define lockdep_assert_preemption_enabled()				\
598 do {									\
599 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
600 		     __lockdep_enabled			&&		\
601 		     (preempt_count() != 0		||		\
602 		      !this_cpu_read(hardirqs_enabled)));		\
603 } while (0)
604 
605 #define lockdep_assert_preemption_disabled()				\
606 do {									\
607 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
608 		     __lockdep_enabled			&&		\
609 		     (preempt_count() == 0		&&		\
610 		      this_cpu_read(hardirqs_enabled)));		\
611 } while (0)
612 
613 /*
614  * Acceptable for protecting per-CPU resources accessed from BH.
615  * Much like in_softirq() - semantics are ambiguous, use carefully.
616  */
617 #define lockdep_assert_in_softirq()					\
618 do {									\
619 	WARN_ON_ONCE(__lockdep_enabled			&&		\
620 		     (!in_softirq() || in_irq() || in_nmi()));		\
621 } while (0)
622 
623 #else
624 # define might_lock(lock) do { } while (0)
625 # define might_lock_read(lock) do { } while (0)
626 # define might_lock_nested(lock, subclass) do { } while (0)
627 
628 # define lockdep_assert_irqs_enabled() do { } while (0)
629 # define lockdep_assert_irqs_disabled() do { } while (0)
630 # define lockdep_assert_in_irq() do { } while (0)
631 
632 # define lockdep_assert_preemption_enabled() do { } while (0)
633 # define lockdep_assert_preemption_disabled() do { } while (0)
634 # define lockdep_assert_in_softirq() do { } while (0)
635 #endif
636 
637 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
638 
639 # define lockdep_assert_RT_in_threaded_ctx() do {			\
640 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
641 			  lockdep_hardirq_context() &&			\
642 			  !(current->hardirq_threaded || current->irq_config),	\
643 			  "Not in threaded context on PREEMPT_RT as expected\n");	\
644 } while (0)
645 
646 #else
647 
648 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
649 
650 #endif
651 
652 #ifdef CONFIG_LOCKDEP
653 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
654 #else
655 static inline void
656 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
657 {
658 }
659 #endif
660 
661 #endif /* __LINUX_LOCKDEP_H */
662