xref: /linux-6.15/include/linux/lockdep.h (revision e2db7592)
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 /* for sysctl */
20 extern int prove_locking;
21 extern int lock_stat;
22 
23 #ifdef CONFIG_LOCKDEP
24 
25 #include <linux/linkage.h>
26 #include <linux/list.h>
27 #include <linux/debug_locks.h>
28 #include <linux/stacktrace.h>
29 
30 static inline void lockdep_copy_map(struct lockdep_map *to,
31 				    struct lockdep_map *from)
32 {
33 	int i;
34 
35 	*to = *from;
36 	/*
37 	 * Since the class cache can be modified concurrently we could observe
38 	 * half pointers (64bit arch using 32bit copy insns). Therefore clear
39 	 * the caches and take the performance hit.
40 	 *
41 	 * XXX it doesn't work well with lockdep_set_class_and_subclass(), since
42 	 *     that relies on cache abuse.
43 	 */
44 	for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
45 		to->class_cache[i] = NULL;
46 }
47 
48 /*
49  * Every lock has a list of other locks that were taken after it.
50  * We only grow the list, never remove from it:
51  */
52 struct lock_list {
53 	struct list_head		entry;
54 	struct lock_class		*class;
55 	struct lock_class		*links_to;
56 	const struct lock_trace		*trace;
57 	u16				distance;
58 	/* bitmap of different dependencies from head to this */
59 	u8				dep;
60 	/* used by BFS to record whether "prev -> this" only has -(*R)-> */
61 	u8				only_xr;
62 
63 	/*
64 	 * The parent field is used to implement breadth-first search, and the
65 	 * bit 0 is reused to indicate if the lock has been accessed in BFS.
66 	 */
67 	struct lock_list		*parent;
68 };
69 
70 /**
71  * struct lock_chain - lock dependency chain record
72  *
73  * @irq_context: the same as irq_context in held_lock below
74  * @depth:       the number of held locks in this chain
75  * @base:        the index in chain_hlocks for this chain
76  * @entry:       the collided lock chains in lock_chain hash list
77  * @chain_key:   the hash key of this lock_chain
78  */
79 struct lock_chain {
80 	/* see BUILD_BUG_ON()s in add_chain_cache() */
81 	unsigned int			irq_context :  2,
82 					depth       :  6,
83 					base	    : 24;
84 	/* 4 byte hole */
85 	struct hlist_node		entry;
86 	u64				chain_key;
87 };
88 
89 #define MAX_LOCKDEP_KEYS_BITS		13
90 #define MAX_LOCKDEP_KEYS		(1UL << MAX_LOCKDEP_KEYS_BITS)
91 #define INITIAL_CHAIN_KEY		-1
92 
93 struct held_lock {
94 	/*
95 	 * One-way hash of the dependency chain up to this point. We
96 	 * hash the hashes step by step as the dependency chain grows.
97 	 *
98 	 * We use it for dependency-caching and we skip detection
99 	 * passes and dependency-updates if there is a cache-hit, so
100 	 * it is absolutely critical for 100% coverage of the validator
101 	 * to have a unique key value for every unique dependency path
102 	 * that can occur in the system, to make a unique hash value
103 	 * as likely as possible - hence the 64-bit width.
104 	 *
105 	 * The task struct holds the current hash value (initialized
106 	 * with zero), here we store the previous hash value:
107 	 */
108 	u64				prev_chain_key;
109 	unsigned long			acquire_ip;
110 	struct lockdep_map		*instance;
111 	struct lockdep_map		*nest_lock;
112 #ifdef CONFIG_LOCK_STAT
113 	u64 				waittime_stamp;
114 	u64				holdtime_stamp;
115 #endif
116 	/*
117 	 * class_idx is zero-indexed; it points to the element in
118 	 * lock_classes this held lock instance belongs to. class_idx is in
119 	 * the range from 0 to (MAX_LOCKDEP_KEYS-1) inclusive.
120 	 */
121 	unsigned int			class_idx:MAX_LOCKDEP_KEYS_BITS;
122 	/*
123 	 * The lock-stack is unified in that the lock chains of interrupt
124 	 * contexts nest ontop of process context chains, but we 'separate'
125 	 * the hashes by starting with 0 if we cross into an interrupt
126 	 * context, and we also keep do not add cross-context lock
127 	 * dependencies - the lock usage graph walking covers that area
128 	 * anyway, and we'd just unnecessarily increase the number of
129 	 * dependencies otherwise. [Note: hardirq and softirq contexts
130 	 * are separated from each other too.]
131 	 *
132 	 * The following field is used to detect when we cross into an
133 	 * interrupt context:
134 	 */
135 	unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
136 	unsigned int trylock:1;						/* 16 bits */
137 
138 	unsigned int read:2;        /* see lock_acquire() comment */
139 	unsigned int check:1;       /* see lock_acquire() comment */
140 	unsigned int hardirqs_off:1;
141 	unsigned int references:12;					/* 32 bits */
142 	unsigned int pin_count;
143 };
144 
145 /*
146  * Initialization, self-test and debugging-output methods:
147  */
148 extern void lockdep_init(void);
149 extern void lockdep_reset(void);
150 extern void lockdep_reset_lock(struct lockdep_map *lock);
151 extern void lockdep_free_key_range(void *start, unsigned long size);
152 extern asmlinkage void lockdep_sys_exit(void);
153 extern void lockdep_set_selftest_task(struct task_struct *task);
154 
155 extern void lockdep_init_task(struct task_struct *task);
156 
157 /*
158  * Split the recursion counter in two to readily detect 'off' vs recursion.
159  */
160 #define LOCKDEP_RECURSION_BITS	16
161 #define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)
162 #define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)
163 
164 /*
165  * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due
166  * to header dependencies.
167  */
168 
169 #define lockdep_off()					\
170 do {							\
171 	current->lockdep_recursion += LOCKDEP_OFF;	\
172 } while (0)
173 
174 #define lockdep_on()					\
175 do {							\
176 	current->lockdep_recursion -= LOCKDEP_OFF;	\
177 } while (0)
178 
179 extern void lockdep_register_key(struct lock_class_key *key);
180 extern void lockdep_unregister_key(struct lock_class_key *key);
181 
182 /*
183  * These methods are used by specific locking variants (spinlocks,
184  * rwlocks, mutexes and rwsems) to pass init/acquire/release events
185  * to lockdep:
186  */
187 
188 extern void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
189 	struct lock_class_key *key, int subclass, u8 inner, u8 outer, u8 lock_type);
190 
191 static inline void
192 lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
193 		       struct lock_class_key *key, int subclass, u8 inner, u8 outer)
194 {
195 	lockdep_init_map_type(lock, name, key, subclass, inner, LD_WAIT_INV, LD_LOCK_NORMAL);
196 }
197 
198 static inline void
199 lockdep_init_map_wait(struct lockdep_map *lock, const char *name,
200 		      struct lock_class_key *key, int subclass, u8 inner)
201 {
202 	lockdep_init_map_waits(lock, name, key, subclass, inner, LD_WAIT_INV);
203 }
204 
205 static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,
206 			     struct lock_class_key *key, int subclass)
207 {
208 	lockdep_init_map_wait(lock, name, key, subclass, LD_WAIT_INV);
209 }
210 
211 /*
212  * Reinitialize a lock key - for cases where there is special locking or
213  * special initialization of locks so that the validator gets the scope
214  * of dependencies wrong: they are either too broad (they need a class-split)
215  * or they are too narrow (they suffer from a false class-split):
216  */
217 #define lockdep_set_class(lock, key)				\
218 	lockdep_init_map_waits(&(lock)->dep_map, #key, key, 0,	\
219 			       (lock)->dep_map.wait_type_inner,	\
220 			       (lock)->dep_map.wait_type_outer)
221 
222 #define lockdep_set_class_and_name(lock, key, name)		\
223 	lockdep_init_map_waits(&(lock)->dep_map, name, key, 0,	\
224 			       (lock)->dep_map.wait_type_inner,	\
225 			       (lock)->dep_map.wait_type_outer)
226 
227 #define lockdep_set_class_and_subclass(lock, key, sub)		\
228 	lockdep_init_map_waits(&(lock)->dep_map, #key, key, sub,\
229 			       (lock)->dep_map.wait_type_inner,	\
230 			       (lock)->dep_map.wait_type_outer)
231 
232 #define lockdep_set_subclass(lock, sub)					\
233 	lockdep_init_map_waits(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
234 			       (lock)->dep_map.wait_type_inner,		\
235 			       (lock)->dep_map.wait_type_outer)
236 
237 #define lockdep_set_novalidate_class(lock) \
238 	lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
239 
240 /*
241  * Compare locking classes
242  */
243 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)
244 
245 static inline int lockdep_match_key(struct lockdep_map *lock,
246 				    struct lock_class_key *key)
247 {
248 	return lock->key == key;
249 }
250 
251 /*
252  * Acquire a lock.
253  *
254  * Values for "read":
255  *
256  *   0: exclusive (write) acquire
257  *   1: read-acquire (no recursion allowed)
258  *   2: read-acquire with same-instance recursion allowed
259  *
260  * Values for check:
261  *
262  *   0: simple checks (freeing, held-at-exit-time, etc.)
263  *   1: full validation
264  */
265 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
266 			 int trylock, int read, int check,
267 			 struct lockdep_map *nest_lock, unsigned long ip);
268 
269 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
270 
271 /* lock_is_held_type() returns */
272 #define LOCK_STATE_UNKNOWN	-1
273 #define LOCK_STATE_NOT_HELD	0
274 #define LOCK_STATE_HELD		1
275 
276 /*
277  * Same "read" as for lock_acquire(), except -1 means any.
278  */
279 extern int lock_is_held_type(const struct lockdep_map *lock, int read);
280 
281 static inline int lock_is_held(const struct lockdep_map *lock)
282 {
283 	return lock_is_held_type(lock, -1);
284 }
285 
286 #define lockdep_is_held(lock)		lock_is_held(&(lock)->dep_map)
287 #define lockdep_is_held_type(lock, r)	lock_is_held_type(&(lock)->dep_map, (r))
288 
289 extern void lock_set_class(struct lockdep_map *lock, const char *name,
290 			   struct lock_class_key *key, unsigned int subclass,
291 			   unsigned long ip);
292 
293 static inline void lock_set_subclass(struct lockdep_map *lock,
294 		unsigned int subclass, unsigned long ip)
295 {
296 	lock_set_class(lock, lock->name, lock->key, subclass, ip);
297 }
298 
299 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
300 
301 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
302 
303 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
304 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
305 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
306 
307 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
308 
309 #define lockdep_assert_held(l)	do {					\
310 		WARN_ON(debug_locks &&					\
311 			lockdep_is_held(l) == LOCK_STATE_NOT_HELD);	\
312 	} while (0)
313 
314 #define lockdep_assert_not_held(l)	do {				\
315 		WARN_ON(debug_locks &&					\
316 			lockdep_is_held(l) == LOCK_STATE_HELD);		\
317 	} while (0)
318 
319 #define lockdep_assert_held_write(l)	do {			\
320 		WARN_ON(debug_locks && !lockdep_is_held_type(l, 0));	\
321 	} while (0)
322 
323 #define lockdep_assert_held_read(l)	do {				\
324 		WARN_ON(debug_locks && !lockdep_is_held_type(l, 1));	\
325 	} while (0)
326 
327 #define lockdep_assert_held_once(l)	do {				\
328 		WARN_ON_ONCE(debug_locks && !lockdep_is_held(l));	\
329 	} while (0)
330 
331 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
332 
333 #define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
334 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
335 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
336 
337 #else /* !CONFIG_LOCKDEP */
338 
339 static inline void lockdep_init_task(struct task_struct *task)
340 {
341 }
342 
343 static inline void lockdep_off(void)
344 {
345 }
346 
347 static inline void lockdep_on(void)
348 {
349 }
350 
351 static inline void lockdep_set_selftest_task(struct task_struct *task)
352 {
353 }
354 
355 # define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
356 # define lock_release(l, i)			do { } while (0)
357 # define lock_downgrade(l, i)			do { } while (0)
358 # define lock_set_class(l, n, k, s, i)		do { } while (0)
359 # define lock_set_subclass(l, s, i)		do { } while (0)
360 # define lockdep_init()				do { } while (0)
361 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
362 		do { (void)(name); (void)(key); } while (0)
363 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
364 		do { (void)(name); (void)(key); } while (0)
365 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
366 		do { (void)(name); (void)(key); } while (0)
367 # define lockdep_init_map(lock, name, key, sub) \
368 		do { (void)(name); (void)(key); } while (0)
369 # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
370 # define lockdep_set_class_and_name(lock, key, name) \
371 		do { (void)(key); (void)(name); } while (0)
372 #define lockdep_set_class_and_subclass(lock, key, sub) \
373 		do { (void)(key); } while (0)
374 #define lockdep_set_subclass(lock, sub)		do { } while (0)
375 
376 #define lockdep_set_novalidate_class(lock) do { } while (0)
377 
378 /*
379  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
380  * case since the result is not well defined and the caller should rather
381  * #ifdef the call himself.
382  */
383 
384 # define lockdep_reset()		do { debug_locks = 1; } while (0)
385 # define lockdep_free_key_range(start, size)	do { } while (0)
386 # define lockdep_sys_exit() 			do { } while (0)
387 
388 static inline void lockdep_register_key(struct lock_class_key *key)
389 {
390 }
391 
392 static inline void lockdep_unregister_key(struct lock_class_key *key)
393 {
394 }
395 
396 #define lockdep_depth(tsk)	(0)
397 
398 /*
399  * Dummy forward declarations, allow users to write less ifdef-y code
400  * and depend on dead code elimination.
401  */
402 extern int lock_is_held(const void *);
403 extern int lockdep_is_held(const void *);
404 #define lockdep_is_held_type(l, r)		(1)
405 
406 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
407 #define lockdep_assert_not_held(l)		do { (void)(l); } while (0)
408 #define lockdep_assert_held_write(l)		do { (void)(l); } while (0)
409 #define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
410 #define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
411 
412 #define lockdep_recursing(tsk)			(0)
413 
414 #define NIL_COOKIE (struct pin_cookie){ }
415 
416 #define lockdep_pin_lock(l)			({ struct pin_cookie cookie = { }; cookie; })
417 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
418 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
419 
420 #endif /* !LOCKDEP */
421 
422 enum xhlock_context_t {
423 	XHLOCK_HARD,
424 	XHLOCK_SOFT,
425 	XHLOCK_CTX_NR,
426 };
427 
428 #define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
429 /*
430  * To initialize a lockdep_map statically use this macro.
431  * Note that _name must not be NULL.
432  */
433 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
434 	{ .name = (_name), .key = (void *)(_key), }
435 
436 static inline void lockdep_invariant_state(bool force) {}
437 static inline void lockdep_free_task(struct task_struct *task) {}
438 
439 #ifdef CONFIG_LOCK_STAT
440 
441 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
442 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
443 
444 #define LOCK_CONTENDED(_lock, try, lock)			\
445 do {								\
446 	if (!try(_lock)) {					\
447 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
448 		lock(_lock);					\
449 	}							\
450 	lock_acquired(&(_lock)->dep_map, _RET_IP_);			\
451 } while (0)
452 
453 #define LOCK_CONTENDED_RETURN(_lock, try, lock)			\
454 ({								\
455 	int ____err = 0;					\
456 	if (!try(_lock)) {					\
457 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
458 		____err = lock(_lock);				\
459 	}							\
460 	if (!____err)						\
461 		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
462 	____err;						\
463 })
464 
465 #else /* CONFIG_LOCK_STAT */
466 
467 #define lock_contended(lockdep_map, ip) do {} while (0)
468 #define lock_acquired(lockdep_map, ip) do {} while (0)
469 
470 #define LOCK_CONTENDED(_lock, try, lock) \
471 	lock(_lock)
472 
473 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
474 	lock(_lock)
475 
476 #endif /* CONFIG_LOCK_STAT */
477 
478 #ifdef CONFIG_LOCKDEP
479 
480 /*
481  * On lockdep we dont want the hand-coded irq-enable of
482  * _raw_*_lock_flags() code, because lockdep assumes
483  * that interrupts are not re-enabled during lock-acquire:
484  */
485 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
486 	LOCK_CONTENDED((_lock), (try), (lock))
487 
488 #else /* CONFIG_LOCKDEP */
489 
490 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
491 	lockfl((_lock), (flags))
492 
493 #endif /* CONFIG_LOCKDEP */
494 
495 #ifdef CONFIG_PROVE_LOCKING
496 extern void print_irqtrace_events(struct task_struct *curr);
497 #else
498 static inline void print_irqtrace_events(struct task_struct *curr)
499 {
500 }
501 #endif
502 
503 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
504 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
505 extern unsigned int force_read_lock_recursive;
506 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
507 #define force_read_lock_recursive 0
508 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
509 
510 #ifdef CONFIG_LOCKDEP
511 extern bool read_lock_is_recursive(void);
512 #else /* CONFIG_LOCKDEP */
513 /* If !LOCKDEP, the value is meaningless */
514 #define read_lock_is_recursive() 0
515 #endif
516 
517 /*
518  * For trivial one-depth nesting of a lock-class, the following
519  * global define can be used. (Subsystems with multiple levels
520  * of nesting should define their own lock-nesting subclasses.)
521  */
522 #define SINGLE_DEPTH_NESTING			1
523 
524 /*
525  * Map the dependency ops to NOP or to real lockdep ops, depending
526  * on the per lock-class debug mode:
527  */
528 
529 #define lock_acquire_exclusive(l, s, t, n, i)		lock_acquire(l, s, t, 0, 1, n, i)
530 #define lock_acquire_shared(l, s, t, n, i)		lock_acquire(l, s, t, 1, 1, n, i)
531 #define lock_acquire_shared_recursive(l, s, t, n, i)	lock_acquire(l, s, t, 2, 1, n, i)
532 
533 #define spin_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
534 #define spin_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
535 #define spin_release(l, i)			lock_release(l, i)
536 
537 #define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
538 #define rwlock_acquire_read(l, s, t, i)					\
539 do {									\
540 	if (read_lock_is_recursive())					\
541 		lock_acquire_shared_recursive(l, s, t, NULL, i);	\
542 	else								\
543 		lock_acquire_shared(l, s, t, NULL, i);			\
544 } while (0)
545 
546 #define rwlock_release(l, i)			lock_release(l, i)
547 
548 #define seqcount_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
549 #define seqcount_acquire_read(l, s, t, i)	lock_acquire_shared_recursive(l, s, t, NULL, i)
550 #define seqcount_release(l, i)			lock_release(l, i)
551 
552 #define mutex_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
553 #define mutex_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
554 #define mutex_release(l, i)			lock_release(l, i)
555 
556 #define rwsem_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
557 #define rwsem_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
558 #define rwsem_acquire_read(l, s, t, i)		lock_acquire_shared(l, s, t, NULL, i)
559 #define rwsem_release(l, i)			lock_release(l, i)
560 
561 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
562 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
563 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
564 #define lock_map_release(l)			lock_release(l, _THIS_IP_)
565 
566 #ifdef CONFIG_PROVE_LOCKING
567 # define might_lock(lock)						\
568 do {									\
569 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
570 	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
571 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
572 } while (0)
573 # define might_lock_read(lock)						\
574 do {									\
575 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
576 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
577 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
578 } while (0)
579 # define might_lock_nested(lock, subclass)				\
580 do {									\
581 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
582 	lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,		\
583 		     _THIS_IP_);					\
584 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
585 } while (0)
586 
587 DECLARE_PER_CPU(int, hardirqs_enabled);
588 DECLARE_PER_CPU(int, hardirq_context);
589 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
590 
591 #define __lockdep_enabled	(debug_locks && !this_cpu_read(lockdep_recursion))
592 
593 #define lockdep_assert_irqs_enabled()					\
594 do {									\
595 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
596 } while (0)
597 
598 #define lockdep_assert_irqs_disabled()					\
599 do {									\
600 	WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
601 } while (0)
602 
603 #define lockdep_assert_in_irq()						\
604 do {									\
605 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
606 } while (0)
607 
608 #define lockdep_assert_preemption_enabled()				\
609 do {									\
610 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
611 		     __lockdep_enabled			&&		\
612 		     (preempt_count() != 0		||		\
613 		      !this_cpu_read(hardirqs_enabled)));		\
614 } while (0)
615 
616 #define lockdep_assert_preemption_disabled()				\
617 do {									\
618 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
619 		     __lockdep_enabled			&&		\
620 		     (preempt_count() == 0		&&		\
621 		      this_cpu_read(hardirqs_enabled)));		\
622 } while (0)
623 
624 /*
625  * Acceptable for protecting per-CPU resources accessed from BH.
626  * Much like in_softirq() - semantics are ambiguous, use carefully.
627  */
628 #define lockdep_assert_in_softirq()					\
629 do {									\
630 	WARN_ON_ONCE(__lockdep_enabled			&&		\
631 		     (!in_softirq() || in_irq() || in_nmi()));		\
632 } while (0)
633 
634 #else
635 # define might_lock(lock) do { } while (0)
636 # define might_lock_read(lock) do { } while (0)
637 # define might_lock_nested(lock, subclass) do { } while (0)
638 
639 # define lockdep_assert_irqs_enabled() do { } while (0)
640 # define lockdep_assert_irqs_disabled() do { } while (0)
641 # define lockdep_assert_in_irq() do { } while (0)
642 
643 # define lockdep_assert_preemption_enabled() do { } while (0)
644 # define lockdep_assert_preemption_disabled() do { } while (0)
645 # define lockdep_assert_in_softirq() do { } while (0)
646 #endif
647 
648 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
649 
650 # define lockdep_assert_RT_in_threaded_ctx() do {			\
651 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
652 			  lockdep_hardirq_context() &&			\
653 			  !(current->hardirq_threaded || current->irq_config),	\
654 			  "Not in threaded context on PREEMPT_RT as expected\n");	\
655 } while (0)
656 
657 #else
658 
659 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
660 
661 #endif
662 
663 #ifdef CONFIG_LOCKDEP
664 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
665 #else
666 static inline void
667 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
668 {
669 }
670 #endif
671 
672 #endif /* __LINUX_LOCKDEP_H */
673