xref: /linux-6.15/include/linux/lockdep.h (revision fbd9a2ce)
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(cond)		\
310 	do { WARN_ON(debug_locks && !(cond)); } while (0)
311 
312 #define lockdep_assert_once(cond)	\
313 	do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
314 
315 #define lockdep_assert_held(l)		\
316 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
317 
318 #define lockdep_assert_not_held(l)	\
319 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
320 
321 #define lockdep_assert_held_write(l)	\
322 	lockdep_assert(lockdep_is_held_type(l, 0))
323 
324 #define lockdep_assert_held_read(l)	\
325 	lockdep_assert(lockdep_is_held_type(l, 1))
326 
327 #define lockdep_assert_held_once(l)		\
328 	lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
329 
330 #define lockdep_assert_none_held_once()		\
331 	lockdep_assert_once(!current->lockdep_depth)
332 /*
333  * Ensure that softirq is handled within the callchain and not delayed and
334  * handled by chance.
335  */
336 #define lockdep_assert_softirq_will_run()	\
337 	lockdep_assert_once(hardirq_count() | softirq_count())
338 
339 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
340 
341 #define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
342 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
343 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
344 
345 #else /* !CONFIG_LOCKDEP */
346 
347 static inline void lockdep_init_task(struct task_struct *task)
348 {
349 }
350 
351 static inline void lockdep_off(void)
352 {
353 }
354 
355 static inline void lockdep_on(void)
356 {
357 }
358 
359 static inline void lockdep_set_selftest_task(struct task_struct *task)
360 {
361 }
362 
363 # define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
364 # define lock_release(l, i)			do { } while (0)
365 # define lock_downgrade(l, i)			do { } while (0)
366 # define lock_set_class(l, n, k, s, i)		do { } while (0)
367 # define lock_set_subclass(l, s, i)		do { } while (0)
368 # define lockdep_init()				do { } while (0)
369 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
370 		do { (void)(name); (void)(key); } while (0)
371 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
372 		do { (void)(name); (void)(key); } while (0)
373 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
374 		do { (void)(name); (void)(key); } while (0)
375 # define lockdep_init_map(lock, name, key, sub) \
376 		do { (void)(name); (void)(key); } while (0)
377 # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
378 # define lockdep_set_class_and_name(lock, key, name) \
379 		do { (void)(key); (void)(name); } while (0)
380 #define lockdep_set_class_and_subclass(lock, key, sub) \
381 		do { (void)(key); } while (0)
382 #define lockdep_set_subclass(lock, sub)		do { } while (0)
383 
384 #define lockdep_set_novalidate_class(lock) do { } while (0)
385 
386 /*
387  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
388  * case since the result is not well defined and the caller should rather
389  * #ifdef the call himself.
390  */
391 
392 # define lockdep_reset()		do { debug_locks = 1; } while (0)
393 # define lockdep_free_key_range(start, size)	do { } while (0)
394 # define lockdep_sys_exit() 			do { } while (0)
395 
396 static inline void lockdep_register_key(struct lock_class_key *key)
397 {
398 }
399 
400 static inline void lockdep_unregister_key(struct lock_class_key *key)
401 {
402 }
403 
404 #define lockdep_depth(tsk)	(0)
405 
406 /*
407  * Dummy forward declarations, allow users to write less ifdef-y code
408  * and depend on dead code elimination.
409  */
410 extern int lock_is_held(const void *);
411 extern int lockdep_is_held(const void *);
412 #define lockdep_is_held_type(l, r)		(1)
413 
414 #define lockdep_assert(c)			do { } while (0)
415 #define lockdep_assert_once(c)			do { } while (0)
416 
417 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
418 #define lockdep_assert_not_held(l)		do { (void)(l); } while (0)
419 #define lockdep_assert_held_write(l)		do { (void)(l); } while (0)
420 #define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
421 #define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
422 #define lockdep_assert_none_held_once()	do { } while (0)
423 #define lockdep_assert_softirq_will_run()	do { } while (0)
424 
425 #define lockdep_recursing(tsk)			(0)
426 
427 #define NIL_COOKIE (struct pin_cookie){ }
428 
429 #define lockdep_pin_lock(l)			({ struct pin_cookie cookie = { }; cookie; })
430 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
431 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
432 
433 #endif /* !LOCKDEP */
434 
435 enum xhlock_context_t {
436 	XHLOCK_HARD,
437 	XHLOCK_SOFT,
438 	XHLOCK_CTX_NR,
439 };
440 
441 #define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
442 /*
443  * To initialize a lockdep_map statically use this macro.
444  * Note that _name must not be NULL.
445  */
446 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
447 	{ .name = (_name), .key = (void *)(_key), }
448 
449 static inline void lockdep_invariant_state(bool force) {}
450 static inline void lockdep_free_task(struct task_struct *task) {}
451 
452 #ifdef CONFIG_LOCK_STAT
453 
454 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
455 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
456 
457 #define LOCK_CONTENDED(_lock, try, lock)			\
458 do {								\
459 	if (!try(_lock)) {					\
460 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
461 		lock(_lock);					\
462 	}							\
463 	lock_acquired(&(_lock)->dep_map, _RET_IP_);			\
464 } while (0)
465 
466 #define LOCK_CONTENDED_RETURN(_lock, try, lock)			\
467 ({								\
468 	int ____err = 0;					\
469 	if (!try(_lock)) {					\
470 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
471 		____err = lock(_lock);				\
472 	}							\
473 	if (!____err)						\
474 		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
475 	____err;						\
476 })
477 
478 #else /* CONFIG_LOCK_STAT */
479 
480 #define lock_contended(lockdep_map, ip) do {} while (0)
481 #define lock_acquired(lockdep_map, ip) do {} while (0)
482 
483 #define LOCK_CONTENDED(_lock, try, lock) \
484 	lock(_lock)
485 
486 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
487 	lock(_lock)
488 
489 #endif /* CONFIG_LOCK_STAT */
490 
491 #ifdef CONFIG_PROVE_LOCKING
492 extern void print_irqtrace_events(struct task_struct *curr);
493 #else
494 static inline void print_irqtrace_events(struct task_struct *curr)
495 {
496 }
497 #endif
498 
499 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
500 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
501 extern unsigned int force_read_lock_recursive;
502 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
503 #define force_read_lock_recursive 0
504 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
505 
506 #ifdef CONFIG_LOCKDEP
507 extern bool read_lock_is_recursive(void);
508 #else /* CONFIG_LOCKDEP */
509 /* If !LOCKDEP, the value is meaningless */
510 #define read_lock_is_recursive() 0
511 #endif
512 
513 /*
514  * For trivial one-depth nesting of a lock-class, the following
515  * global define can be used. (Subsystems with multiple levels
516  * of nesting should define their own lock-nesting subclasses.)
517  */
518 #define SINGLE_DEPTH_NESTING			1
519 
520 /*
521  * Map the dependency ops to NOP or to real lockdep ops, depending
522  * on the per lock-class debug mode:
523  */
524 
525 #define lock_acquire_exclusive(l, s, t, n, i)		lock_acquire(l, s, t, 0, 1, n, i)
526 #define lock_acquire_shared(l, s, t, n, i)		lock_acquire(l, s, t, 1, 1, n, i)
527 #define lock_acquire_shared_recursive(l, s, t, n, i)	lock_acquire(l, s, t, 2, 1, n, i)
528 
529 #define spin_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
530 #define spin_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
531 #define spin_release(l, i)			lock_release(l, i)
532 
533 #define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
534 #define rwlock_acquire_read(l, s, t, i)					\
535 do {									\
536 	if (read_lock_is_recursive())					\
537 		lock_acquire_shared_recursive(l, s, t, NULL, i);	\
538 	else								\
539 		lock_acquire_shared(l, s, t, NULL, i);			\
540 } while (0)
541 
542 #define rwlock_release(l, i)			lock_release(l, i)
543 
544 #define seqcount_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
545 #define seqcount_acquire_read(l, s, t, i)	lock_acquire_shared_recursive(l, s, t, NULL, i)
546 #define seqcount_release(l, i)			lock_release(l, i)
547 
548 #define mutex_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
549 #define mutex_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
550 #define mutex_release(l, i)			lock_release(l, i)
551 
552 #define rwsem_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
553 #define rwsem_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
554 #define rwsem_acquire_read(l, s, t, i)		lock_acquire_shared(l, s, t, NULL, i)
555 #define rwsem_release(l, i)			lock_release(l, i)
556 
557 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
558 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
559 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
560 #define lock_map_release(l)			lock_release(l, _THIS_IP_)
561 
562 #ifdef CONFIG_PROVE_LOCKING
563 # define might_lock(lock)						\
564 do {									\
565 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
566 	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
567 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
568 } while (0)
569 # define might_lock_read(lock)						\
570 do {									\
571 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
572 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
573 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
574 } while (0)
575 # define might_lock_nested(lock, subclass)				\
576 do {									\
577 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
578 	lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,		\
579 		     _THIS_IP_);					\
580 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
581 } while (0)
582 
583 DECLARE_PER_CPU(int, hardirqs_enabled);
584 DECLARE_PER_CPU(int, hardirq_context);
585 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
586 
587 #define __lockdep_enabled	(debug_locks && !this_cpu_read(lockdep_recursion))
588 
589 #define lockdep_assert_irqs_enabled()					\
590 do {									\
591 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
592 } while (0)
593 
594 #define lockdep_assert_irqs_disabled()					\
595 do {									\
596 	WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
597 } while (0)
598 
599 #define lockdep_assert_in_irq()						\
600 do {									\
601 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
602 } while (0)
603 
604 #define lockdep_assert_preemption_enabled()				\
605 do {									\
606 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
607 		     __lockdep_enabled			&&		\
608 		     (preempt_count() != 0		||		\
609 		      !this_cpu_read(hardirqs_enabled)));		\
610 } while (0)
611 
612 #define lockdep_assert_preemption_disabled()				\
613 do {									\
614 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
615 		     __lockdep_enabled			&&		\
616 		     (preempt_count() == 0		&&		\
617 		      this_cpu_read(hardirqs_enabled)));		\
618 } while (0)
619 
620 /*
621  * Acceptable for protecting per-CPU resources accessed from BH.
622  * Much like in_softirq() - semantics are ambiguous, use carefully.
623  */
624 #define lockdep_assert_in_softirq()					\
625 do {									\
626 	WARN_ON_ONCE(__lockdep_enabled			&&		\
627 		     (!in_softirq() || in_irq() || in_nmi()));		\
628 } while (0)
629 
630 #else
631 # define might_lock(lock) do { } while (0)
632 # define might_lock_read(lock) do { } while (0)
633 # define might_lock_nested(lock, subclass) do { } while (0)
634 
635 # define lockdep_assert_irqs_enabled() do { } while (0)
636 # define lockdep_assert_irqs_disabled() do { } while (0)
637 # define lockdep_assert_in_irq() do { } while (0)
638 
639 # define lockdep_assert_preemption_enabled() do { } while (0)
640 # define lockdep_assert_preemption_disabled() do { } while (0)
641 # define lockdep_assert_in_softirq() do { } while (0)
642 #endif
643 
644 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
645 
646 # define lockdep_assert_RT_in_threaded_ctx() do {			\
647 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
648 			  lockdep_hardirq_context() &&			\
649 			  !(current->hardirq_threaded || current->irq_config),	\
650 			  "Not in threaded context on PREEMPT_RT as expected\n");	\
651 } while (0)
652 
653 #else
654 
655 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
656 
657 #endif
658 
659 #ifdef CONFIG_LOCKDEP
660 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
661 #else
662 static inline void
663 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
664 {
665 }
666 #endif
667 
668 #endif /* __LINUX_LOCKDEP_H */
669