xref: /linux-6.15/include/linux/lockdep.h (revision e00a844a)
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.txt for more details.
9  */
10 #ifndef __LINUX_LOCKDEP_H
11 #define __LINUX_LOCKDEP_H
12 
13 struct task_struct;
14 struct lockdep_map;
15 
16 /* for sysctl */
17 extern int prove_locking;
18 extern int lock_stat;
19 
20 #define MAX_LOCKDEP_SUBCLASSES		8UL
21 
22 #include <linux/types.h>
23 
24 #ifdef CONFIG_LOCKDEP
25 
26 #include <linux/linkage.h>
27 #include <linux/list.h>
28 #include <linux/debug_locks.h>
29 #include <linux/stacktrace.h>
30 
31 /*
32  * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
33  * the total number of states... :-(
34  */
35 #define XXX_LOCK_USAGE_STATES		(1+2*4)
36 
37 /*
38  * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
39  * cached in the instance of lockdep_map
40  *
41  * Currently main class (subclass == 0) and signle depth subclass
42  * are cached in lockdep_map. This optimization is mainly targeting
43  * on rq->lock. double_rq_lock() acquires this highly competitive with
44  * single depth.
45  */
46 #define NR_LOCKDEP_CACHING_CLASSES	2
47 
48 /*
49  * Lock-classes are keyed via unique addresses, by embedding the
50  * lockclass-key into the kernel (or module) .data section. (For
51  * static locks we use the lock address itself as the key.)
52  */
53 struct lockdep_subclass_key {
54 	char __one_byte;
55 } __attribute__ ((__packed__));
56 
57 struct lock_class_key {
58 	struct lockdep_subclass_key	subkeys[MAX_LOCKDEP_SUBCLASSES];
59 };
60 
61 extern struct lock_class_key __lockdep_no_validate__;
62 
63 #define LOCKSTAT_POINTS		4
64 
65 /*
66  * The lock-class itself:
67  */
68 struct lock_class {
69 	/*
70 	 * class-hash:
71 	 */
72 	struct hlist_node		hash_entry;
73 
74 	/*
75 	 * global list of all lock-classes:
76 	 */
77 	struct list_head		lock_entry;
78 
79 	struct lockdep_subclass_key	*key;
80 	unsigned int			subclass;
81 	unsigned int			dep_gen_id;
82 
83 	/*
84 	 * IRQ/softirq usage tracking bits:
85 	 */
86 	unsigned long			usage_mask;
87 	struct stack_trace		usage_traces[XXX_LOCK_USAGE_STATES];
88 
89 	/*
90 	 * These fields represent a directed graph of lock dependencies,
91 	 * to every node we attach a list of "forward" and a list of
92 	 * "backward" graph nodes.
93 	 */
94 	struct list_head		locks_after, locks_before;
95 
96 	/*
97 	 * Generation counter, when doing certain classes of graph walking,
98 	 * to ensure that we check one node only once:
99 	 */
100 	unsigned int			version;
101 
102 	/*
103 	 * Statistics counter:
104 	 */
105 	unsigned long			ops;
106 
107 	const char			*name;
108 	int				name_version;
109 
110 #ifdef CONFIG_LOCK_STAT
111 	unsigned long			contention_point[LOCKSTAT_POINTS];
112 	unsigned long			contending_point[LOCKSTAT_POINTS];
113 #endif
114 };
115 
116 #ifdef CONFIG_LOCK_STAT
117 struct lock_time {
118 	s64				min;
119 	s64				max;
120 	s64				total;
121 	unsigned long			nr;
122 };
123 
124 enum bounce_type {
125 	bounce_acquired_write,
126 	bounce_acquired_read,
127 	bounce_contended_write,
128 	bounce_contended_read,
129 	nr_bounce_types,
130 
131 	bounce_acquired = bounce_acquired_write,
132 	bounce_contended = bounce_contended_write,
133 };
134 
135 struct lock_class_stats {
136 	unsigned long			contention_point[LOCKSTAT_POINTS];
137 	unsigned long			contending_point[LOCKSTAT_POINTS];
138 	struct lock_time		read_waittime;
139 	struct lock_time		write_waittime;
140 	struct lock_time		read_holdtime;
141 	struct lock_time		write_holdtime;
142 	unsigned long			bounces[nr_bounce_types];
143 };
144 
145 struct lock_class_stats lock_stats(struct lock_class *class);
146 void clear_lock_stats(struct lock_class *class);
147 #endif
148 
149 /*
150  * Map the lock object (the lock instance) to the lock-class object.
151  * This is embedded into specific lock instances:
152  */
153 struct lockdep_map {
154 	struct lock_class_key		*key;
155 	struct lock_class		*class_cache[NR_LOCKDEP_CACHING_CLASSES];
156 	const char			*name;
157 #ifdef CONFIG_LOCK_STAT
158 	int				cpu;
159 	unsigned long			ip;
160 #endif
161 #ifdef CONFIG_LOCKDEP_CROSSRELEASE
162 	/*
163 	 * Whether it's a crosslock.
164 	 */
165 	int				cross;
166 #endif
167 };
168 
169 static inline void lockdep_copy_map(struct lockdep_map *to,
170 				    struct lockdep_map *from)
171 {
172 	int i;
173 
174 	*to = *from;
175 	/*
176 	 * Since the class cache can be modified concurrently we could observe
177 	 * half pointers (64bit arch using 32bit copy insns). Therefore clear
178 	 * the caches and take the performance hit.
179 	 *
180 	 * XXX it doesn't work well with lockdep_set_class_and_subclass(), since
181 	 *     that relies on cache abuse.
182 	 */
183 	for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
184 		to->class_cache[i] = NULL;
185 }
186 
187 /*
188  * Every lock has a list of other locks that were taken after it.
189  * We only grow the list, never remove from it:
190  */
191 struct lock_list {
192 	struct list_head		entry;
193 	struct lock_class		*class;
194 	struct stack_trace		trace;
195 	int				distance;
196 
197 	/*
198 	 * The parent field is used to implement breadth-first search, and the
199 	 * bit 0 is reused to indicate if the lock has been accessed in BFS.
200 	 */
201 	struct lock_list		*parent;
202 };
203 
204 /*
205  * We record lock dependency chains, so that we can cache them:
206  */
207 struct lock_chain {
208 	/* see BUILD_BUG_ON()s in lookup_chain_cache() */
209 	unsigned int			irq_context :  2,
210 					depth       :  6,
211 					base	    : 24;
212 	/* 4 byte hole */
213 	struct hlist_node		entry;
214 	u64				chain_key;
215 };
216 
217 #define MAX_LOCKDEP_KEYS_BITS		13
218 /*
219  * Subtract one because we offset hlock->class_idx by 1 in order
220  * to make 0 mean no class. This avoids overflowing the class_idx
221  * bitfield and hitting the BUG in hlock_class().
222  */
223 #define MAX_LOCKDEP_KEYS		((1UL << MAX_LOCKDEP_KEYS_BITS) - 1)
224 
225 struct held_lock {
226 	/*
227 	 * One-way hash of the dependency chain up to this point. We
228 	 * hash the hashes step by step as the dependency chain grows.
229 	 *
230 	 * We use it for dependency-caching and we skip detection
231 	 * passes and dependency-updates if there is a cache-hit, so
232 	 * it is absolutely critical for 100% coverage of the validator
233 	 * to have a unique key value for every unique dependency path
234 	 * that can occur in the system, to make a unique hash value
235 	 * as likely as possible - hence the 64-bit width.
236 	 *
237 	 * The task struct holds the current hash value (initialized
238 	 * with zero), here we store the previous hash value:
239 	 */
240 	u64				prev_chain_key;
241 	unsigned long			acquire_ip;
242 	struct lockdep_map		*instance;
243 	struct lockdep_map		*nest_lock;
244 #ifdef CONFIG_LOCK_STAT
245 	u64 				waittime_stamp;
246 	u64				holdtime_stamp;
247 #endif
248 	unsigned int			class_idx:MAX_LOCKDEP_KEYS_BITS;
249 	/*
250 	 * The lock-stack is unified in that the lock chains of interrupt
251 	 * contexts nest ontop of process context chains, but we 'separate'
252 	 * the hashes by starting with 0 if we cross into an interrupt
253 	 * context, and we also keep do not add cross-context lock
254 	 * dependencies - the lock usage graph walking covers that area
255 	 * anyway, and we'd just unnecessarily increase the number of
256 	 * dependencies otherwise. [Note: hardirq and softirq contexts
257 	 * are separated from each other too.]
258 	 *
259 	 * The following field is used to detect when we cross into an
260 	 * interrupt context:
261 	 */
262 	unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
263 	unsigned int trylock:1;						/* 16 bits */
264 
265 	unsigned int read:2;        /* see lock_acquire() comment */
266 	unsigned int check:1;       /* see lock_acquire() comment */
267 	unsigned int hardirqs_off:1;
268 	unsigned int references:12;					/* 32 bits */
269 	unsigned int pin_count;
270 #ifdef CONFIG_LOCKDEP_CROSSRELEASE
271 	/*
272 	 * Generation id.
273 	 *
274 	 * A value of cross_gen_id will be stored when holding this,
275 	 * which is globally increased whenever each crosslock is held.
276 	 */
277 	unsigned int gen_id;
278 #endif
279 };
280 
281 #ifdef CONFIG_LOCKDEP_CROSSRELEASE
282 #define MAX_XHLOCK_TRACE_ENTRIES 5
283 
284 /*
285  * This is for keeping locks waiting for commit so that true dependencies
286  * can be added at commit step.
287  */
288 struct hist_lock {
289 	/*
290 	 * Id for each entry in the ring buffer. This is used to
291 	 * decide whether the ring buffer was overwritten or not.
292 	 *
293 	 * For example,
294 	 *
295 	 *           |<----------- hist_lock ring buffer size ------->|
296 	 *           pppppppppppppppppppppiiiiiiiiiiiiiiiiiiiiiiiiiiiii
297 	 * wrapped > iiiiiiiiiiiiiiiiiiiiiiiiiii.......................
298 	 *
299 	 *           where 'p' represents an acquisition in process
300 	 *           context, 'i' represents an acquisition in irq
301 	 *           context.
302 	 *
303 	 * In this example, the ring buffer was overwritten by
304 	 * acquisitions in irq context, that should be detected on
305 	 * rollback or commit.
306 	 */
307 	unsigned int hist_id;
308 
309 	/*
310 	 * Seperate stack_trace data. This will be used at commit step.
311 	 */
312 	struct stack_trace	trace;
313 	unsigned long		trace_entries[MAX_XHLOCK_TRACE_ENTRIES];
314 
315 	/*
316 	 * Seperate hlock instance. This will be used at commit step.
317 	 *
318 	 * TODO: Use a smaller data structure containing only necessary
319 	 * data. However, we should make lockdep code able to handle the
320 	 * smaller one first.
321 	 */
322 	struct held_lock	hlock;
323 };
324 
325 /*
326  * To initialize a lock as crosslock, lockdep_init_map_crosslock() should
327  * be called instead of lockdep_init_map().
328  */
329 struct cross_lock {
330 	/*
331 	 * When more than one acquisition of crosslocks are overlapped,
332 	 * we have to perform commit for them based on cross_gen_id of
333 	 * the first acquisition, which allows us to add more true
334 	 * dependencies.
335 	 *
336 	 * Moreover, when no acquisition of a crosslock is in progress,
337 	 * we should not perform commit because the lock might not exist
338 	 * any more, which might cause incorrect memory access. So we
339 	 * have to track the number of acquisitions of a crosslock.
340 	 */
341 	int nr_acquire;
342 
343 	/*
344 	 * Seperate hlock instance. This will be used at commit step.
345 	 *
346 	 * TODO: Use a smaller data structure containing only necessary
347 	 * data. However, we should make lockdep code able to handle the
348 	 * smaller one first.
349 	 */
350 	struct held_lock	hlock;
351 };
352 
353 struct lockdep_map_cross {
354 	struct lockdep_map map;
355 	struct cross_lock xlock;
356 };
357 #endif
358 
359 /*
360  * Initialization, self-test and debugging-output methods:
361  */
362 extern void lockdep_info(void);
363 extern void lockdep_reset(void);
364 extern void lockdep_reset_lock(struct lockdep_map *lock);
365 extern void lockdep_free_key_range(void *start, unsigned long size);
366 extern asmlinkage void lockdep_sys_exit(void);
367 
368 extern void lockdep_off(void);
369 extern void lockdep_on(void);
370 
371 /*
372  * These methods are used by specific locking variants (spinlocks,
373  * rwlocks, mutexes and rwsems) to pass init/acquire/release events
374  * to lockdep:
375  */
376 
377 extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
378 			     struct lock_class_key *key, int subclass);
379 
380 /*
381  * Reinitialize a lock key - for cases where there is special locking or
382  * special initialization of locks so that the validator gets the scope
383  * of dependencies wrong: they are either too broad (they need a class-split)
384  * or they are too narrow (they suffer from a false class-split):
385  */
386 #define lockdep_set_class(lock, key) \
387 		lockdep_init_map(&(lock)->dep_map, #key, key, 0)
388 #define lockdep_set_class_and_name(lock, key, name) \
389 		lockdep_init_map(&(lock)->dep_map, name, key, 0)
390 #define lockdep_set_class_and_subclass(lock, key, sub) \
391 		lockdep_init_map(&(lock)->dep_map, #key, key, sub)
392 #define lockdep_set_subclass(lock, sub)	\
393 		lockdep_init_map(&(lock)->dep_map, #lock, \
394 				 (lock)->dep_map.key, sub)
395 
396 #define lockdep_set_novalidate_class(lock) \
397 	lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
398 /*
399  * Compare locking classes
400  */
401 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)
402 
403 static inline int lockdep_match_key(struct lockdep_map *lock,
404 				    struct lock_class_key *key)
405 {
406 	return lock->key == key;
407 }
408 
409 /*
410  * Acquire a lock.
411  *
412  * Values for "read":
413  *
414  *   0: exclusive (write) acquire
415  *   1: read-acquire (no recursion allowed)
416  *   2: read-acquire with same-instance recursion allowed
417  *
418  * Values for check:
419  *
420  *   0: simple checks (freeing, held-at-exit-time, etc.)
421  *   1: full validation
422  */
423 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
424 			 int trylock, int read, int check,
425 			 struct lockdep_map *nest_lock, unsigned long ip);
426 
427 extern void lock_release(struct lockdep_map *lock, int nested,
428 			 unsigned long ip);
429 
430 /*
431  * Same "read" as for lock_acquire(), except -1 means any.
432  */
433 extern int lock_is_held_type(struct lockdep_map *lock, int read);
434 
435 static inline int lock_is_held(struct lockdep_map *lock)
436 {
437 	return lock_is_held_type(lock, -1);
438 }
439 
440 #define lockdep_is_held(lock)		lock_is_held(&(lock)->dep_map)
441 #define lockdep_is_held_type(lock, r)	lock_is_held_type(&(lock)->dep_map, (r))
442 
443 extern void lock_set_class(struct lockdep_map *lock, const char *name,
444 			   struct lock_class_key *key, unsigned int subclass,
445 			   unsigned long ip);
446 
447 static inline void lock_set_subclass(struct lockdep_map *lock,
448 		unsigned int subclass, unsigned long ip)
449 {
450 	lock_set_class(lock, lock->name, lock->key, subclass, ip);
451 }
452 
453 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
454 
455 struct pin_cookie { unsigned int val; };
456 
457 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
458 
459 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
460 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
461 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
462 
463 # define INIT_LOCKDEP				.lockdep_recursion = 0,
464 
465 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
466 
467 #define lockdep_assert_held(l)	do {				\
468 		WARN_ON(debug_locks && !lockdep_is_held(l));	\
469 	} while (0)
470 
471 #define lockdep_assert_held_exclusive(l)	do {			\
472 		WARN_ON(debug_locks && !lockdep_is_held_type(l, 0));	\
473 	} while (0)
474 
475 #define lockdep_assert_held_read(l)	do {				\
476 		WARN_ON(debug_locks && !lockdep_is_held_type(l, 1));	\
477 	} while (0)
478 
479 #define lockdep_assert_held_once(l)	do {				\
480 		WARN_ON_ONCE(debug_locks && !lockdep_is_held(l));	\
481 	} while (0)
482 
483 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
484 
485 #define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
486 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
487 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
488 
489 #else /* !CONFIG_LOCKDEP */
490 
491 static inline void lockdep_off(void)
492 {
493 }
494 
495 static inline void lockdep_on(void)
496 {
497 }
498 
499 # define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
500 # define lock_release(l, n, i)			do { } while (0)
501 # define lock_downgrade(l, i)			do { } while (0)
502 # define lock_set_class(l, n, k, s, i)		do { } while (0)
503 # define lock_set_subclass(l, s, i)		do { } while (0)
504 # define lockdep_info()				do { } while (0)
505 # define lockdep_init_map(lock, name, key, sub) \
506 		do { (void)(name); (void)(key); } while (0)
507 # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
508 # define lockdep_set_class_and_name(lock, key, name) \
509 		do { (void)(key); (void)(name); } while (0)
510 #define lockdep_set_class_and_subclass(lock, key, sub) \
511 		do { (void)(key); } while (0)
512 #define lockdep_set_subclass(lock, sub)		do { } while (0)
513 
514 #define lockdep_set_novalidate_class(lock) do { } while (0)
515 
516 /*
517  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
518  * case since the result is not well defined and the caller should rather
519  * #ifdef the call himself.
520  */
521 
522 # define INIT_LOCKDEP
523 # define lockdep_reset()		do { debug_locks = 1; } while (0)
524 # define lockdep_free_key_range(start, size)	do { } while (0)
525 # define lockdep_sys_exit() 			do { } while (0)
526 /*
527  * The class key takes no space if lockdep is disabled:
528  */
529 struct lock_class_key { };
530 
531 /*
532  * The lockdep_map takes no space if lockdep is disabled:
533  */
534 struct lockdep_map { };
535 
536 #define lockdep_depth(tsk)	(0)
537 
538 #define lockdep_is_held_type(l, r)		(1)
539 
540 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
541 #define lockdep_assert_held_exclusive(l)	do { (void)(l); } while (0)
542 #define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
543 #define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
544 
545 #define lockdep_recursing(tsk)			(0)
546 
547 struct pin_cookie { };
548 
549 #define NIL_COOKIE (struct pin_cookie){ }
550 
551 #define lockdep_pin_lock(l)			({ struct pin_cookie cookie; cookie; })
552 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
553 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
554 
555 #endif /* !LOCKDEP */
556 
557 enum xhlock_context_t {
558 	XHLOCK_HARD,
559 	XHLOCK_SOFT,
560 	XHLOCK_CTX_NR,
561 };
562 
563 #ifdef CONFIG_LOCKDEP_CROSSRELEASE
564 extern void lockdep_init_map_crosslock(struct lockdep_map *lock,
565 				       const char *name,
566 				       struct lock_class_key *key,
567 				       int subclass);
568 extern void lock_commit_crosslock(struct lockdep_map *lock);
569 
570 /*
571  * What we essencially have to initialize is 'nr_acquire'. Other members
572  * will be initialized in add_xlock().
573  */
574 #define STATIC_CROSS_LOCK_INIT() \
575 	{ .nr_acquire = 0,}
576 
577 #define STATIC_CROSS_LOCKDEP_MAP_INIT(_name, _key) \
578 	{ .map.name = (_name), .map.key = (void *)(_key), \
579 	  .map.cross = 1, .xlock = STATIC_CROSS_LOCK_INIT(), }
580 
581 /*
582  * To initialize a lockdep_map statically use this macro.
583  * Note that _name must not be NULL.
584  */
585 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
586 	{ .name = (_name), .key = (void *)(_key), .cross = 0, }
587 
588 extern void crossrelease_hist_start(enum xhlock_context_t c);
589 extern void crossrelease_hist_end(enum xhlock_context_t c);
590 extern void lockdep_invariant_state(bool force);
591 extern void lockdep_init_task(struct task_struct *task);
592 extern void lockdep_free_task(struct task_struct *task);
593 #else /* !CROSSRELEASE */
594 #define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
595 /*
596  * To initialize a lockdep_map statically use this macro.
597  * Note that _name must not be NULL.
598  */
599 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
600 	{ .name = (_name), .key = (void *)(_key), }
601 
602 static inline void crossrelease_hist_start(enum xhlock_context_t c) {}
603 static inline void crossrelease_hist_end(enum xhlock_context_t c) {}
604 static inline void lockdep_invariant_state(bool force) {}
605 static inline void lockdep_init_task(struct task_struct *task) {}
606 static inline void lockdep_free_task(struct task_struct *task) {}
607 #endif /* CROSSRELEASE */
608 
609 #ifdef CONFIG_LOCK_STAT
610 
611 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
612 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
613 
614 #define LOCK_CONTENDED(_lock, try, lock)			\
615 do {								\
616 	if (!try(_lock)) {					\
617 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
618 		lock(_lock);					\
619 	}							\
620 	lock_acquired(&(_lock)->dep_map, _RET_IP_);			\
621 } while (0)
622 
623 #define LOCK_CONTENDED_RETURN(_lock, try, lock)			\
624 ({								\
625 	int ____err = 0;					\
626 	if (!try(_lock)) {					\
627 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
628 		____err = lock(_lock);				\
629 	}							\
630 	if (!____err)						\
631 		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
632 	____err;						\
633 })
634 
635 #else /* CONFIG_LOCK_STAT */
636 
637 #define lock_contended(lockdep_map, ip) do {} while (0)
638 #define lock_acquired(lockdep_map, ip) do {} while (0)
639 
640 #define LOCK_CONTENDED(_lock, try, lock) \
641 	lock(_lock)
642 
643 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
644 	lock(_lock)
645 
646 #endif /* CONFIG_LOCK_STAT */
647 
648 #ifdef CONFIG_LOCKDEP
649 
650 /*
651  * On lockdep we dont want the hand-coded irq-enable of
652  * _raw_*_lock_flags() code, because lockdep assumes
653  * that interrupts are not re-enabled during lock-acquire:
654  */
655 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
656 	LOCK_CONTENDED((_lock), (try), (lock))
657 
658 #else /* CONFIG_LOCKDEP */
659 
660 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
661 	lockfl((_lock), (flags))
662 
663 #endif /* CONFIG_LOCKDEP */
664 
665 #ifdef CONFIG_TRACE_IRQFLAGS
666 extern void print_irqtrace_events(struct task_struct *curr);
667 #else
668 static inline void print_irqtrace_events(struct task_struct *curr)
669 {
670 }
671 #endif
672 
673 /*
674  * For trivial one-depth nesting of a lock-class, the following
675  * global define can be used. (Subsystems with multiple levels
676  * of nesting should define their own lock-nesting subclasses.)
677  */
678 #define SINGLE_DEPTH_NESTING			1
679 
680 /*
681  * Map the dependency ops to NOP or to real lockdep ops, depending
682  * on the per lock-class debug mode:
683  */
684 
685 #define lock_acquire_exclusive(l, s, t, n, i)		lock_acquire(l, s, t, 0, 1, n, i)
686 #define lock_acquire_shared(l, s, t, n, i)		lock_acquire(l, s, t, 1, 1, n, i)
687 #define lock_acquire_shared_recursive(l, s, t, n, i)	lock_acquire(l, s, t, 2, 1, n, i)
688 
689 #define spin_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
690 #define spin_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
691 #define spin_release(l, n, i)			lock_release(l, n, i)
692 
693 #define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
694 #define rwlock_acquire_read(l, s, t, i)		lock_acquire_shared_recursive(l, s, t, NULL, i)
695 #define rwlock_release(l, n, i)			lock_release(l, n, i)
696 
697 #define seqcount_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
698 #define seqcount_acquire_read(l, s, t, i)	lock_acquire_shared_recursive(l, s, t, NULL, i)
699 #define seqcount_release(l, n, i)		lock_release(l, n, i)
700 
701 #define mutex_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
702 #define mutex_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
703 #define mutex_release(l, n, i)			lock_release(l, n, i)
704 
705 #define rwsem_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
706 #define rwsem_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
707 #define rwsem_acquire_read(l, s, t, i)		lock_acquire_shared(l, s, t, NULL, i)
708 #define rwsem_release(l, n, i)			lock_release(l, n, i)
709 
710 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
711 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
712 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
713 #define lock_map_release(l)			lock_release(l, 1, _THIS_IP_)
714 
715 #ifdef CONFIG_PROVE_LOCKING
716 # define might_lock(lock) 						\
717 do {									\
718 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
719 	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
720 	lock_release(&(lock)->dep_map, 0, _THIS_IP_);			\
721 } while (0)
722 # define might_lock_read(lock) 						\
723 do {									\
724 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
725 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
726 	lock_release(&(lock)->dep_map, 0, _THIS_IP_);			\
727 } while (0)
728 
729 #define lockdep_assert_irqs_enabled()	do {				\
730 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
731 			  !current->hardirqs_enabled,			\
732 			  "IRQs not enabled as expected\n");		\
733 	} while (0)
734 
735 #define lockdep_assert_irqs_disabled()	do {				\
736 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
737 			  current->hardirqs_enabled,			\
738 			  "IRQs not disabled as expected\n");		\
739 	} while (0)
740 
741 #else
742 # define might_lock(lock) do { } while (0)
743 # define might_lock_read(lock) do { } while (0)
744 # define lockdep_assert_irqs_enabled() do { } while (0)
745 # define lockdep_assert_irqs_disabled() do { } while (0)
746 #endif
747 
748 #ifdef CONFIG_LOCKDEP
749 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
750 #else
751 static inline void
752 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
753 {
754 }
755 #endif
756 
757 #endif /* __LINUX_LOCKDEP_H */
758