1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Runtime locking correctness validator
4  *
5  *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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 
lockdep_copy_map(struct lockdep_map * to,struct lockdep_map * from)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 /*
86  * Initialization, self-test and debugging-output methods:
87  */
88 extern void lockdep_init(void);
89 extern void lockdep_reset(void);
90 extern void lockdep_reset_lock(struct lockdep_map *lock);
91 extern void lockdep_free_key_range(void *start, unsigned long size);
92 extern asmlinkage void lockdep_sys_exit(void);
93 extern void lockdep_set_selftest_task(struct task_struct *task);
94 
95 extern void lockdep_init_task(struct task_struct *task);
96 
97 /*
98  * Split the recursion counter in two to readily detect 'off' vs recursion.
99  */
100 #define LOCKDEP_RECURSION_BITS	16
101 #define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)
102 #define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)
103 
104 /*
105  * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due
106  * to header dependencies.
107  */
108 
109 #define lockdep_off()					\
110 do {							\
111 	current->lockdep_recursion += LOCKDEP_OFF;	\
112 } while (0)
113 
114 #define lockdep_on()					\
115 do {							\
116 	current->lockdep_recursion -= LOCKDEP_OFF;	\
117 } while (0)
118 
119 extern void lockdep_register_key(struct lock_class_key *key);
120 extern void lockdep_unregister_key(struct lock_class_key *key);
121 
122 /*
123  * These methods are used by specific locking variants (spinlocks,
124  * rwlocks, mutexes and rwsems) to pass init/acquire/release events
125  * to lockdep:
126  */
127 
128 extern void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
129 	struct lock_class_key *key, int subclass, u8 inner, u8 outer, u8 lock_type);
130 
131 static inline void
lockdep_init_map_waits(struct lockdep_map * lock,const char * name,struct lock_class_key * key,int subclass,u8 inner,u8 outer)132 lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
133 		       struct lock_class_key *key, int subclass, u8 inner, u8 outer)
134 {
135 	lockdep_init_map_type(lock, name, key, subclass, inner, outer, LD_LOCK_NORMAL);
136 }
137 
138 static inline void
lockdep_init_map_wait(struct lockdep_map * lock,const char * name,struct lock_class_key * key,int subclass,u8 inner)139 lockdep_init_map_wait(struct lockdep_map *lock, const char *name,
140 		      struct lock_class_key *key, int subclass, u8 inner)
141 {
142 	lockdep_init_map_waits(lock, name, key, subclass, inner, LD_WAIT_INV);
143 }
144 
lockdep_init_map(struct lockdep_map * lock,const char * name,struct lock_class_key * key,int subclass)145 static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,
146 			     struct lock_class_key *key, int subclass)
147 {
148 	lockdep_init_map_wait(lock, name, key, subclass, LD_WAIT_INV);
149 }
150 
151 /*
152  * Reinitialize a lock key - for cases where there is special locking or
153  * special initialization of locks so that the validator gets the scope
154  * of dependencies wrong: they are either too broad (they need a class-split)
155  * or they are too narrow (they suffer from a false class-split):
156  */
157 #define lockdep_set_class(lock, key)				\
158 	lockdep_init_map_type(&(lock)->dep_map, #key, key, 0,	\
159 			      (lock)->dep_map.wait_type_inner,	\
160 			      (lock)->dep_map.wait_type_outer,	\
161 			      (lock)->dep_map.lock_type)
162 
163 #define lockdep_set_class_and_name(lock, key, name)		\
164 	lockdep_init_map_type(&(lock)->dep_map, name, key, 0,	\
165 			      (lock)->dep_map.wait_type_inner,	\
166 			      (lock)->dep_map.wait_type_outer,	\
167 			      (lock)->dep_map.lock_type)
168 
169 #define lockdep_set_class_and_subclass(lock, key, sub)		\
170 	lockdep_init_map_type(&(lock)->dep_map, #key, key, sub,	\
171 			      (lock)->dep_map.wait_type_inner,	\
172 			      (lock)->dep_map.wait_type_outer,	\
173 			      (lock)->dep_map.lock_type)
174 
175 #define lockdep_set_subclass(lock, sub)					\
176 	lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
177 			      (lock)->dep_map.wait_type_inner,		\
178 			      (lock)->dep_map.wait_type_outer,		\
179 			      (lock)->dep_map.lock_type)
180 
181 /**
182  * lockdep_set_novalidate_class: disable checking of lock ordering on a given
183  * lock
184  * @lock: Lock to mark
185  *
186  * Lockdep will still record that this lock has been taken, and print held
187  * instances when dumping locks
188  */
189 #define lockdep_set_novalidate_class(lock) \
190 	lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
191 
192 /**
193  * lockdep_set_notrack_class: disable lockdep tracking of a given lock entirely
194  * @lock: Lock to mark
195  *
196  * Bigger hammer than lockdep_set_novalidate_class: so far just for bcachefs,
197  * which takes more locks than lockdep is able to track (48).
198  */
199 #define lockdep_set_notrack_class(lock) \
200 	lockdep_set_class_and_name(lock, &__lockdep_no_track__, #lock)
201 
202 /*
203  * Compare locking classes
204  */
205 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)
206 
lockdep_match_key(struct lockdep_map * lock,struct lock_class_key * key)207 static inline int lockdep_match_key(struct lockdep_map *lock,
208 				    struct lock_class_key *key)
209 {
210 	return lock->key == key;
211 }
212 
213 /*
214  * Acquire a lock.
215  *
216  * Values for "read":
217  *
218  *   0: exclusive (write) acquire
219  *   1: read-acquire (no recursion allowed)
220  *   2: read-acquire with same-instance recursion allowed
221  *
222  * Values for check:
223  *
224  *   0: simple checks (freeing, held-at-exit-time, etc.)
225  *   1: full validation
226  */
227 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
228 			 int trylock, int read, int check,
229 			 struct lockdep_map *nest_lock, unsigned long ip);
230 
231 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
232 
233 extern void lock_sync(struct lockdep_map *lock, unsigned int subclass,
234 		      int read, int check, struct lockdep_map *nest_lock,
235 		      unsigned long ip);
236 
237 /* lock_is_held_type() returns */
238 #define LOCK_STATE_UNKNOWN	-1
239 #define LOCK_STATE_NOT_HELD	0
240 #define LOCK_STATE_HELD		1
241 
242 /*
243  * Same "read" as for lock_acquire(), except -1 means any.
244  */
245 extern int lock_is_held_type(const struct lockdep_map *lock, int read);
246 
lock_is_held(const struct lockdep_map * lock)247 static inline int lock_is_held(const struct lockdep_map *lock)
248 {
249 	return lock_is_held_type(lock, -1);
250 }
251 
252 #define lockdep_is_held(lock)		lock_is_held(&(lock)->dep_map)
253 #define lockdep_is_held_type(lock, r)	lock_is_held_type(&(lock)->dep_map, (r))
254 
255 extern void lock_set_class(struct lockdep_map *lock, const char *name,
256 			   struct lock_class_key *key, unsigned int subclass,
257 			   unsigned long ip);
258 
259 #define lock_set_novalidate_class(l, n, i) \
260 	lock_set_class(l, n, &__lockdep_no_validate__, 0, i)
261 
lock_set_subclass(struct lockdep_map * lock,unsigned int subclass,unsigned long ip)262 static inline void lock_set_subclass(struct lockdep_map *lock,
263 		unsigned int subclass, unsigned long ip)
264 {
265 	lock_set_class(lock, lock->name, lock->key, subclass, ip);
266 }
267 
268 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
269 
270 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
271 
272 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
273 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
274 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
275 
276 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
277 
278 #define lockdep_assert(cond)		\
279 	do { WARN_ON(debug_locks && !(cond)); } while (0)
280 
281 #define lockdep_assert_once(cond)	\
282 	do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
283 
284 #define lockdep_assert_held(l)		\
285 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
286 
287 #define lockdep_assert_not_held(l)	\
288 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
289 
290 #define lockdep_assert_held_write(l)	\
291 	lockdep_assert(lockdep_is_held_type(l, 0))
292 
293 #define lockdep_assert_held_read(l)	\
294 	lockdep_assert(lockdep_is_held_type(l, 1))
295 
296 #define lockdep_assert_held_once(l)		\
297 	lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
298 
299 #define lockdep_assert_none_held_once()		\
300 	lockdep_assert_once(!current->lockdep_depth)
301 
302 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
303 
304 #define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
305 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
306 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
307 
308 /*
309  * Must use lock_map_aquire_try() with override maps to avoid
310  * lockdep thinking they participate in the block chain.
311  */
312 #define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type)	\
313 	struct lockdep_map _name = {			\
314 		.name = #_name "-wait-type-override",	\
315 		.wait_type_inner = _wait_type,		\
316 		.lock_type = LD_LOCK_WAIT_OVERRIDE, }
317 
318 #else /* !CONFIG_LOCKDEP */
319 
lockdep_init_task(struct task_struct * task)320 static inline void lockdep_init_task(struct task_struct *task)
321 {
322 }
323 
lockdep_off(void)324 static inline void lockdep_off(void)
325 {
326 }
327 
lockdep_on(void)328 static inline void lockdep_on(void)
329 {
330 }
331 
lockdep_set_selftest_task(struct task_struct * task)332 static inline void lockdep_set_selftest_task(struct task_struct *task)
333 {
334 }
335 
336 # define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
337 # define lock_release(l, i)			do { } while (0)
338 # define lock_downgrade(l, i)			do { } while (0)
339 # define lock_set_class(l, n, key, s, i)	do { (void)(key); } while (0)
340 # define lock_set_novalidate_class(l, n, i)	do { } while (0)
341 # define lock_set_subclass(l, s, i)		do { } while (0)
342 # define lockdep_init()				do { } while (0)
343 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
344 		do { (void)(name); (void)(key); } while (0)
345 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
346 		do { (void)(name); (void)(key); } while (0)
347 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
348 		do { (void)(name); (void)(key); } while (0)
349 # define lockdep_init_map(lock, name, key, sub) \
350 		do { (void)(name); (void)(key); } while (0)
351 # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
352 # define lockdep_set_class_and_name(lock, key, name) \
353 		do { (void)(key); (void)(name); } while (0)
354 #define lockdep_set_class_and_subclass(lock, key, sub) \
355 		do { (void)(key); } while (0)
356 #define lockdep_set_subclass(lock, sub)		do { } while (0)
357 
358 #define lockdep_set_novalidate_class(lock) do { } while (0)
359 #define lockdep_set_notrack_class(lock) do { } while (0)
360 
361 /*
362  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
363  * case since the result is not well defined and the caller should rather
364  * #ifdef the call himself.
365  */
366 
367 # define lockdep_reset()		do { debug_locks = 1; } while (0)
368 # define lockdep_free_key_range(start, size)	do { } while (0)
369 # define lockdep_sys_exit() 			do { } while (0)
370 
lockdep_register_key(struct lock_class_key * key)371 static inline void lockdep_register_key(struct lock_class_key *key)
372 {
373 }
374 
lockdep_unregister_key(struct lock_class_key * key)375 static inline void lockdep_unregister_key(struct lock_class_key *key)
376 {
377 }
378 
379 #define lockdep_depth(tsk)	(0)
380 
381 /*
382  * Dummy forward declarations, allow users to write less ifdef-y code
383  * and depend on dead code elimination.
384  */
385 extern int lock_is_held(const void *);
386 extern int lockdep_is_held(const void *);
387 #define lockdep_is_held_type(l, r)		(1)
388 
389 #define lockdep_assert(c)			do { } while (0)
390 #define lockdep_assert_once(c)			do { } while (0)
391 
392 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
393 #define lockdep_assert_not_held(l)		do { (void)(l); } while (0)
394 #define lockdep_assert_held_write(l)		do { (void)(l); } while (0)
395 #define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
396 #define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
397 #define lockdep_assert_none_held_once()	do { } while (0)
398 
399 #define lockdep_recursing(tsk)			(0)
400 
401 #define NIL_COOKIE (struct pin_cookie){ }
402 
403 #define lockdep_pin_lock(l)			({ struct pin_cookie cookie = { }; cookie; })
404 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
405 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
406 
407 #define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type)	\
408 	struct lockdep_map __maybe_unused _name = {}
409 
410 #endif /* !LOCKDEP */
411 
412 #ifdef CONFIG_PROVE_LOCKING
413 void lockdep_set_lock_cmp_fn(struct lockdep_map *, lock_cmp_fn, lock_print_fn);
414 
415 #define lock_set_cmp_fn(lock, ...)	lockdep_set_lock_cmp_fn(&(lock)->dep_map, __VA_ARGS__)
416 #else
417 #define lock_set_cmp_fn(lock, ...)	do { } while (0)
418 #endif
419 
420 enum xhlock_context_t {
421 	XHLOCK_HARD,
422 	XHLOCK_SOFT,
423 	XHLOCK_CTX_NR,
424 };
425 
426 /*
427  * To initialize a lockdep_map statically use this macro.
428  * Note that _name must not be NULL.
429  */
430 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
431 	{ .name = (_name), .key = (void *)(_key), }
432 
lockdep_invariant_state(bool force)433 static inline void lockdep_invariant_state(bool force) {}
lockdep_free_task(struct task_struct * task)434 static inline void lockdep_free_task(struct task_struct *task) {}
435 
436 #ifdef CONFIG_LOCK_STAT
437 
438 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
439 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
440 
441 #define LOCK_CONTENDED(_lock, try, lock)			\
442 do {								\
443 	if (!try(_lock)) {					\
444 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
445 		lock(_lock);					\
446 	}							\
447 	lock_acquired(&(_lock)->dep_map, _RET_IP_);			\
448 } while (0)
449 
450 #define LOCK_CONTENDED_RETURN(_lock, try, lock)			\
451 ({								\
452 	int ____err = 0;					\
453 	if (!try(_lock)) {					\
454 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
455 		____err = lock(_lock);				\
456 	}							\
457 	if (!____err)						\
458 		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
459 	____err;						\
460 })
461 
462 #else /* CONFIG_LOCK_STAT */
463 
464 #define lock_contended(lockdep_map, ip) do {} while (0)
465 #define lock_acquired(lockdep_map, ip) do {} while (0)
466 
467 #define LOCK_CONTENDED(_lock, try, lock) \
468 	lock(_lock)
469 
470 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
471 	lock(_lock)
472 
473 #endif /* CONFIG_LOCK_STAT */
474 
475 #ifdef CONFIG_PROVE_LOCKING
476 extern void print_irqtrace_events(struct task_struct *curr);
477 #else
print_irqtrace_events(struct task_struct * curr)478 static inline void print_irqtrace_events(struct task_struct *curr)
479 {
480 }
481 #endif
482 
483 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
484 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
485 extern unsigned int force_read_lock_recursive;
486 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
487 #define force_read_lock_recursive 0
488 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
489 
490 #ifdef CONFIG_LOCKDEP
491 extern bool read_lock_is_recursive(void);
492 #else /* CONFIG_LOCKDEP */
493 /* If !LOCKDEP, the value is meaningless */
494 #define read_lock_is_recursive() 0
495 #endif
496 
497 /*
498  * For trivial one-depth nesting of a lock-class, the following
499  * global define can be used. (Subsystems with multiple levels
500  * of nesting should define their own lock-nesting subclasses.)
501  */
502 #define SINGLE_DEPTH_NESTING			1
503 
504 /*
505  * Map the dependency ops to NOP or to real lockdep ops, depending
506  * on the per lock-class debug mode:
507  */
508 
509 #define lock_acquire_exclusive(l, s, t, n, i)		lock_acquire(l, s, t, 0, 1, n, i)
510 #define lock_acquire_shared(l, s, t, n, i)		lock_acquire(l, s, t, 1, 1, n, i)
511 #define lock_acquire_shared_recursive(l, s, t, n, i)	lock_acquire(l, s, t, 2, 1, n, i)
512 
513 #define spin_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
514 #define spin_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
515 #define spin_release(l, i)			lock_release(l, i)
516 
517 #define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
518 #define rwlock_acquire_read(l, s, t, i)					\
519 do {									\
520 	if (read_lock_is_recursive())					\
521 		lock_acquire_shared_recursive(l, s, t, NULL, i);	\
522 	else								\
523 		lock_acquire_shared(l, s, t, NULL, i);			\
524 } while (0)
525 
526 #define rwlock_release(l, i)			lock_release(l, i)
527 
528 #define seqcount_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
529 #define seqcount_acquire_read(l, s, t, i)	lock_acquire_shared_recursive(l, s, t, NULL, i)
530 #define seqcount_release(l, i)			lock_release(l, i)
531 
532 #define mutex_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
533 #define mutex_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
534 #define mutex_release(l, i)			lock_release(l, i)
535 
536 #define rwsem_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
537 #define rwsem_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
538 #define rwsem_acquire_read(l, s, t, i)		lock_acquire_shared(l, s, t, NULL, i)
539 #define rwsem_release(l, i)			lock_release(l, i)
540 
541 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
542 #define lock_map_acquire_try(l)			lock_acquire_exclusive(l, 0, 1, NULL, _THIS_IP_)
543 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
544 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
545 #define lock_map_release(l)			lock_release(l, _THIS_IP_)
546 #define lock_map_sync(l)			lock_sync(l, 0, 0, 1, NULL, _THIS_IP_)
547 
548 #ifdef CONFIG_PROVE_LOCKING
549 # define might_lock(lock)						\
550 do {									\
551 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
552 	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
553 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
554 } while (0)
555 # define might_lock_read(lock)						\
556 do {									\
557 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
558 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
559 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
560 } while (0)
561 # define might_lock_nested(lock, subclass)				\
562 do {									\
563 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
564 	lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,		\
565 		     _THIS_IP_);					\
566 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
567 } while (0)
568 
569 DECLARE_PER_CPU(int, hardirqs_enabled);
570 DECLARE_PER_CPU(int, hardirq_context);
571 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
572 
573 #define __lockdep_enabled	(debug_locks && !this_cpu_read(lockdep_recursion))
574 
575 #define lockdep_assert_irqs_enabled()					\
576 do {									\
577 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
578 } while (0)
579 
580 #define lockdep_assert_irqs_disabled()					\
581 do {									\
582 	WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
583 } while (0)
584 
585 #define lockdep_assert_in_irq()						\
586 do {									\
587 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
588 } while (0)
589 
590 #define lockdep_assert_no_hardirq()					\
591 do {									\
592 	WARN_ON_ONCE(__lockdep_enabled && (this_cpu_read(hardirq_context) || \
593 					   !this_cpu_read(hardirqs_enabled))); \
594 } while (0)
595 
596 #define lockdep_assert_preemption_enabled()				\
597 do {									\
598 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
599 		     __lockdep_enabled			&&		\
600 		     (preempt_count() != 0		||		\
601 		      !this_cpu_read(hardirqs_enabled)));		\
602 } while (0)
603 
604 #define lockdep_assert_preemption_disabled()				\
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 /*
613  * Acceptable for protecting per-CPU resources accessed from BH.
614  * Much like in_softirq() - semantics are ambiguous, use carefully.
615  */
616 #define lockdep_assert_in_softirq()					\
617 do {									\
618 	WARN_ON_ONCE(__lockdep_enabled			&&		\
619 		     (!in_softirq() || in_irq() || in_nmi()));		\
620 } while (0)
621 
622 extern void lockdep_assert_in_softirq_func(void);
623 
624 #else
625 # define might_lock(lock) do { } while (0)
626 # define might_lock_read(lock) do { } while (0)
627 # define might_lock_nested(lock, subclass) do { } while (0)
628 
629 # define lockdep_assert_irqs_enabled() do { } while (0)
630 # define lockdep_assert_irqs_disabled() do { } while (0)
631 # define lockdep_assert_in_irq() do { } while (0)
632 # define lockdep_assert_no_hardirq() do { } while (0)
633 
634 # define lockdep_assert_preemption_enabled() do { } while (0)
635 # define lockdep_assert_preemption_disabled() do { } while (0)
636 # define lockdep_assert_in_softirq() do { } while (0)
637 # define lockdep_assert_in_softirq_func() do { } while (0)
638 #endif
639 
640 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
641 
642 # define lockdep_assert_RT_in_threaded_ctx() do {			\
643 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
644 			  lockdep_hardirq_context() &&			\
645 			  !(current->hardirq_threaded || current->irq_config),	\
646 			  "Not in threaded context on PREEMPT_RT as expected\n");	\
647 } while (0)
648 
649 #else
650 
651 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
652 
653 #endif
654 
655 #ifdef CONFIG_LOCKDEP
656 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
657 #else
658 static inline void
lockdep_rcu_suspicious(const char * file,const int line,const char * s)659 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
660 {
661 }
662 #endif
663 
664 #endif /* __LINUX_LOCKDEP_H */
665