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 #define MAX_LOCKDEP_KEYS_BITS		13
86 #define MAX_LOCKDEP_KEYS		(1UL << MAX_LOCKDEP_KEYS_BITS)
87 #define INITIAL_CHAIN_KEY		-1
88 
89 struct held_lock {
90 	/*
91 	 * One-way hash of the dependency chain up to this point. We
92 	 * hash the hashes step by step as the dependency chain grows.
93 	 *
94 	 * We use it for dependency-caching and we skip detection
95 	 * passes and dependency-updates if there is a cache-hit, so
96 	 * it is absolutely critical for 100% coverage of the validator
97 	 * to have a unique key value for every unique dependency path
98 	 * that can occur in the system, to make a unique hash value
99 	 * as likely as possible - hence the 64-bit width.
100 	 *
101 	 * The task struct holds the current hash value (initialized
102 	 * with zero), here we store the previous hash value:
103 	 */
104 	u64				prev_chain_key;
105 	unsigned long			acquire_ip;
106 	struct lockdep_map		*instance;
107 	struct lockdep_map		*nest_lock;
108 #ifdef CONFIG_LOCK_STAT
109 	u64 				waittime_stamp;
110 	u64				holdtime_stamp;
111 #endif
112 	/*
113 	 * class_idx is zero-indexed; it points to the element in
114 	 * lock_classes this held lock instance belongs to. class_idx is in
115 	 * the range from 0 to (MAX_LOCKDEP_KEYS-1) inclusive.
116 	 */
117 	unsigned int			class_idx:MAX_LOCKDEP_KEYS_BITS;
118 	/*
119 	 * The lock-stack is unified in that the lock chains of interrupt
120 	 * contexts nest ontop of process context chains, but we 'separate'
121 	 * the hashes by starting with 0 if we cross into an interrupt
122 	 * context, and we also keep do not add cross-context lock
123 	 * dependencies - the lock usage graph walking covers that area
124 	 * anyway, and we'd just unnecessarily increase the number of
125 	 * dependencies otherwise. [Note: hardirq and softirq contexts
126 	 * are separated from each other too.]
127 	 *
128 	 * The following field is used to detect when we cross into an
129 	 * interrupt context:
130 	 */
131 	unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
132 	unsigned int trylock:1;						/* 16 bits */
133 
134 	unsigned int read:2;        /* see lock_acquire() comment */
135 	unsigned int check:1;       /* see lock_acquire() comment */
136 	unsigned int hardirqs_off:1;
137 	unsigned int references:12;					/* 32 bits */
138 	unsigned int pin_count;
139 };
140 
141 /*
142  * Initialization, self-test and debugging-output methods:
143  */
144 extern void lockdep_init(void);
145 extern void lockdep_reset(void);
146 extern void lockdep_reset_lock(struct lockdep_map *lock);
147 extern void lockdep_free_key_range(void *start, unsigned long size);
148 extern asmlinkage void lockdep_sys_exit(void);
149 extern void lockdep_set_selftest_task(struct task_struct *task);
150 
151 extern void lockdep_init_task(struct task_struct *task);
152 
153 /*
154  * Split the recursion counter in two to readily detect 'off' vs recursion.
155  */
156 #define LOCKDEP_RECURSION_BITS	16
157 #define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)
158 #define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)
159 
160 /*
161  * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due
162  * to header dependencies.
163  */
164 
165 #define lockdep_off()					\
166 do {							\
167 	current->lockdep_recursion += LOCKDEP_OFF;	\
168 } while (0)
169 
170 #define lockdep_on()					\
171 do {							\
172 	current->lockdep_recursion -= LOCKDEP_OFF;	\
173 } while (0)
174 
175 extern void lockdep_register_key(struct lock_class_key *key);
176 extern void lockdep_unregister_key(struct lock_class_key *key);
177 
178 /*
179  * These methods are used by specific locking variants (spinlocks,
180  * rwlocks, mutexes and rwsems) to pass init/acquire/release events
181  * to lockdep:
182  */
183 
184 extern void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
185 	struct lock_class_key *key, int subclass, u8 inner, u8 outer, u8 lock_type);
186 
187 static inline void
lockdep_init_map_waits(struct lockdep_map * lock,const char * name,struct lock_class_key * key,int subclass,u8 inner,u8 outer)188 lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
189 		       struct lock_class_key *key, int subclass, u8 inner, u8 outer)
190 {
191 	lockdep_init_map_type(lock, name, key, subclass, inner, outer, LD_LOCK_NORMAL);
192 }
193 
194 static inline void
lockdep_init_map_wait(struct lockdep_map * lock,const char * name,struct lock_class_key * key,int subclass,u8 inner)195 lockdep_init_map_wait(struct lockdep_map *lock, const char *name,
196 		      struct lock_class_key *key, int subclass, u8 inner)
197 {
198 	lockdep_init_map_waits(lock, name, key, subclass, inner, LD_WAIT_INV);
199 }
200 
lockdep_init_map(struct lockdep_map * lock,const char * name,struct lock_class_key * key,int subclass)201 static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,
202 			     struct lock_class_key *key, int subclass)
203 {
204 	lockdep_init_map_wait(lock, name, key, subclass, LD_WAIT_INV);
205 }
206 
207 /*
208  * Reinitialize a lock key - for cases where there is special locking or
209  * special initialization of locks so that the validator gets the scope
210  * of dependencies wrong: they are either too broad (they need a class-split)
211  * or they are too narrow (they suffer from a false class-split):
212  */
213 #define lockdep_set_class(lock, key)				\
214 	lockdep_init_map_type(&(lock)->dep_map, #key, key, 0,	\
215 			      (lock)->dep_map.wait_type_inner,	\
216 			      (lock)->dep_map.wait_type_outer,	\
217 			      (lock)->dep_map.lock_type)
218 
219 #define lockdep_set_class_and_name(lock, key, name)		\
220 	lockdep_init_map_type(&(lock)->dep_map, name, key, 0,	\
221 			      (lock)->dep_map.wait_type_inner,	\
222 			      (lock)->dep_map.wait_type_outer,	\
223 			      (lock)->dep_map.lock_type)
224 
225 #define lockdep_set_class_and_subclass(lock, key, sub)		\
226 	lockdep_init_map_type(&(lock)->dep_map, #key, key, sub,	\
227 			      (lock)->dep_map.wait_type_inner,	\
228 			      (lock)->dep_map.wait_type_outer,	\
229 			      (lock)->dep_map.lock_type)
230 
231 #define lockdep_set_subclass(lock, sub)					\
232 	lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
233 			      (lock)->dep_map.wait_type_inner,		\
234 			      (lock)->dep_map.wait_type_outer,		\
235 			      (lock)->dep_map.lock_type)
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 
lockdep_match_key(struct lockdep_map * lock,struct lock_class_key * key)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 
lock_is_held(const struct lockdep_map * lock)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 #define lock_set_novalidate_class(l, n, i) \
294 	lock_set_class(l, n, &__lockdep_no_validate__, 0, i)
295 
lock_set_subclass(struct lockdep_map * lock,unsigned int subclass,unsigned long ip)296 static inline void lock_set_subclass(struct lockdep_map *lock,
297 		unsigned int subclass, unsigned long ip)
298 {
299 	lock_set_class(lock, lock->name, lock->key, subclass, ip);
300 }
301 
302 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
303 
304 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
305 
306 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
307 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
308 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
309 
310 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
311 
312 #define lockdep_assert(cond)		\
313 	do { WARN_ON(debug_locks && !(cond)); } while (0)
314 
315 #define lockdep_assert_once(cond)	\
316 	do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
317 
318 #define lockdep_assert_held(l)		\
319 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
320 
321 #define lockdep_assert_not_held(l)	\
322 	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
323 
324 #define lockdep_assert_held_write(l)	\
325 	lockdep_assert(lockdep_is_held_type(l, 0))
326 
327 #define lockdep_assert_held_read(l)	\
328 	lockdep_assert(lockdep_is_held_type(l, 1))
329 
330 #define lockdep_assert_held_once(l)		\
331 	lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
332 
333 #define lockdep_assert_none_held_once()		\
334 	lockdep_assert_once(!current->lockdep_depth)
335 
336 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
337 
338 #define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
339 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
340 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
341 
342 #else /* !CONFIG_LOCKDEP */
343 
lockdep_init_task(struct task_struct * task)344 static inline void lockdep_init_task(struct task_struct *task)
345 {
346 }
347 
lockdep_off(void)348 static inline void lockdep_off(void)
349 {
350 }
351 
lockdep_on(void)352 static inline void lockdep_on(void)
353 {
354 }
355 
lockdep_set_selftest_task(struct task_struct * task)356 static inline void lockdep_set_selftest_task(struct task_struct *task)
357 {
358 }
359 
360 # define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
361 # define lock_release(l, i)			do { } while (0)
362 # define lock_downgrade(l, i)			do { } while (0)
363 # define lock_set_class(l, n, key, s, i)	do { (void)(key); } while (0)
364 # define lock_set_novalidate_class(l, n, i)	do { } while (0)
365 # define lock_set_subclass(l, s, i)		do { } while (0)
366 # define lockdep_init()				do { } while (0)
367 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
368 		do { (void)(name); (void)(key); } while (0)
369 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
370 		do { (void)(name); (void)(key); } while (0)
371 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
372 		do { (void)(name); (void)(key); } while (0)
373 # define lockdep_init_map(lock, name, key, sub) \
374 		do { (void)(name); (void)(key); } while (0)
375 # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
376 # define lockdep_set_class_and_name(lock, key, name) \
377 		do { (void)(key); (void)(name); } while (0)
378 #define lockdep_set_class_and_subclass(lock, key, sub) \
379 		do { (void)(key); } while (0)
380 #define lockdep_set_subclass(lock, sub)		do { } while (0)
381 
382 #define lockdep_set_novalidate_class(lock) do { } while (0)
383 
384 /*
385  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
386  * case since the result is not well defined and the caller should rather
387  * #ifdef the call himself.
388  */
389 
390 # define lockdep_reset()		do { debug_locks = 1; } while (0)
391 # define lockdep_free_key_range(start, size)	do { } while (0)
392 # define lockdep_sys_exit() 			do { } while (0)
393 
lockdep_register_key(struct lock_class_key * key)394 static inline void lockdep_register_key(struct lock_class_key *key)
395 {
396 }
397 
lockdep_unregister_key(struct lock_class_key * key)398 static inline void lockdep_unregister_key(struct lock_class_key *key)
399 {
400 }
401 
402 #define lockdep_depth(tsk)	(0)
403 
404 /*
405  * Dummy forward declarations, allow users to write less ifdef-y code
406  * and depend on dead code elimination.
407  */
408 extern int lock_is_held(const void *);
409 extern int lockdep_is_held(const void *);
410 #define lockdep_is_held_type(l, r)		(1)
411 
412 #define lockdep_assert(c)			do { } while (0)
413 #define lockdep_assert_once(c)			do { } while (0)
414 
415 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
416 #define lockdep_assert_not_held(l)		do { (void)(l); } while (0)
417 #define lockdep_assert_held_write(l)		do { (void)(l); } while (0)
418 #define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
419 #define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
420 #define lockdep_assert_none_held_once()	do { } while (0)
421 
422 #define lockdep_recursing(tsk)			(0)
423 
424 #define NIL_COOKIE (struct pin_cookie){ }
425 
426 #define lockdep_pin_lock(l)			({ struct pin_cookie cookie = { }; cookie; })
427 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
428 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
429 
430 #endif /* !LOCKDEP */
431 
432 enum xhlock_context_t {
433 	XHLOCK_HARD,
434 	XHLOCK_SOFT,
435 	XHLOCK_CTX_NR,
436 };
437 
438 #define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
439 /*
440  * To initialize a lockdep_map statically use this macro.
441  * Note that _name must not be NULL.
442  */
443 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
444 	{ .name = (_name), .key = (void *)(_key), }
445 
lockdep_invariant_state(bool force)446 static inline void lockdep_invariant_state(bool force) {}
lockdep_free_task(struct task_struct * task)447 static inline void lockdep_free_task(struct task_struct *task) {}
448 
449 #ifdef CONFIG_LOCK_STAT
450 
451 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
452 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
453 
454 #define LOCK_CONTENDED(_lock, try, lock)			\
455 do {								\
456 	if (!try(_lock)) {					\
457 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
458 		lock(_lock);					\
459 	}							\
460 	lock_acquired(&(_lock)->dep_map, _RET_IP_);			\
461 } while (0)
462 
463 #define LOCK_CONTENDED_RETURN(_lock, try, lock)			\
464 ({								\
465 	int ____err = 0;					\
466 	if (!try(_lock)) {					\
467 		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
468 		____err = lock(_lock);				\
469 	}							\
470 	if (!____err)						\
471 		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
472 	____err;						\
473 })
474 
475 #else /* CONFIG_LOCK_STAT */
476 
477 #define lock_contended(lockdep_map, ip) do {} while (0)
478 #define lock_acquired(lockdep_map, ip) do {} while (0)
479 
480 #define LOCK_CONTENDED(_lock, try, lock) \
481 	lock(_lock)
482 
483 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
484 	lock(_lock)
485 
486 #endif /* CONFIG_LOCK_STAT */
487 
488 #ifdef CONFIG_PROVE_LOCKING
489 extern void print_irqtrace_events(struct task_struct *curr);
490 #else
print_irqtrace_events(struct task_struct * curr)491 static inline void print_irqtrace_events(struct task_struct *curr)
492 {
493 }
494 #endif
495 
496 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
497 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
498 extern unsigned int force_read_lock_recursive;
499 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
500 #define force_read_lock_recursive 0
501 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
502 
503 #ifdef CONFIG_LOCKDEP
504 extern bool read_lock_is_recursive(void);
505 #else /* CONFIG_LOCKDEP */
506 /* If !LOCKDEP, the value is meaningless */
507 #define read_lock_is_recursive() 0
508 #endif
509 
510 /*
511  * For trivial one-depth nesting of a lock-class, the following
512  * global define can be used. (Subsystems with multiple levels
513  * of nesting should define their own lock-nesting subclasses.)
514  */
515 #define SINGLE_DEPTH_NESTING			1
516 
517 /*
518  * Map the dependency ops to NOP or to real lockdep ops, depending
519  * on the per lock-class debug mode:
520  */
521 
522 #define lock_acquire_exclusive(l, s, t, n, i)		lock_acquire(l, s, t, 0, 1, n, i)
523 #define lock_acquire_shared(l, s, t, n, i)		lock_acquire(l, s, t, 1, 1, n, i)
524 #define lock_acquire_shared_recursive(l, s, t, n, i)	lock_acquire(l, s, t, 2, 1, n, i)
525 
526 #define spin_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
527 #define spin_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
528 #define spin_release(l, i)			lock_release(l, i)
529 
530 #define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
531 #define rwlock_acquire_read(l, s, t, i)					\
532 do {									\
533 	if (read_lock_is_recursive())					\
534 		lock_acquire_shared_recursive(l, s, t, NULL, i);	\
535 	else								\
536 		lock_acquire_shared(l, s, t, NULL, i);			\
537 } while (0)
538 
539 #define rwlock_release(l, i)			lock_release(l, i)
540 
541 #define seqcount_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
542 #define seqcount_acquire_read(l, s, t, i)	lock_acquire_shared_recursive(l, s, t, NULL, i)
543 #define seqcount_release(l, i)			lock_release(l, i)
544 
545 #define mutex_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
546 #define mutex_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
547 #define mutex_release(l, i)			lock_release(l, i)
548 
549 #define rwsem_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
550 #define rwsem_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
551 #define rwsem_acquire_read(l, s, t, i)		lock_acquire_shared(l, s, t, NULL, i)
552 #define rwsem_release(l, i)			lock_release(l, i)
553 
554 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
555 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
556 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
557 #define lock_map_release(l)			lock_release(l, _THIS_IP_)
558 
559 #ifdef CONFIG_PROVE_LOCKING
560 # define might_lock(lock)						\
561 do {									\
562 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
563 	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
564 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
565 } while (0)
566 # define might_lock_read(lock)						\
567 do {									\
568 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
569 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
570 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
571 } while (0)
572 # define might_lock_nested(lock, subclass)				\
573 do {									\
574 	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
575 	lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,		\
576 		     _THIS_IP_);					\
577 	lock_release(&(lock)->dep_map, _THIS_IP_);			\
578 } while (0)
579 
580 DECLARE_PER_CPU(int, hardirqs_enabled);
581 DECLARE_PER_CPU(int, hardirq_context);
582 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
583 
584 #define __lockdep_enabled	(debug_locks && !this_cpu_read(lockdep_recursion))
585 
586 #define lockdep_assert_irqs_enabled()					\
587 do {									\
588 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
589 } while (0)
590 
591 #define lockdep_assert_irqs_disabled()					\
592 do {									\
593 	WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
594 } while (0)
595 
596 #define lockdep_assert_in_irq()						\
597 do {									\
598 	WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
599 } while (0)
600 
601 #define lockdep_assert_preemption_enabled()				\
602 do {									\
603 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
604 		     __lockdep_enabled			&&		\
605 		     (preempt_count() != 0		||		\
606 		      !this_cpu_read(hardirqs_enabled)));		\
607 } while (0)
608 
609 #define lockdep_assert_preemption_disabled()				\
610 do {									\
611 	WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)	&&		\
612 		     __lockdep_enabled			&&		\
613 		     (preempt_count() == 0		&&		\
614 		      this_cpu_read(hardirqs_enabled)));		\
615 } while (0)
616 
617 /*
618  * Acceptable for protecting per-CPU resources accessed from BH.
619  * Much like in_softirq() - semantics are ambiguous, use carefully.
620  */
621 #define lockdep_assert_in_softirq()					\
622 do {									\
623 	WARN_ON_ONCE(__lockdep_enabled			&&		\
624 		     (!in_softirq() || in_irq() || in_nmi()));		\
625 } while (0)
626 
627 #else
628 # define might_lock(lock) do { } while (0)
629 # define might_lock_read(lock) do { } while (0)
630 # define might_lock_nested(lock, subclass) do { } while (0)
631 
632 # define lockdep_assert_irqs_enabled() do { } while (0)
633 # define lockdep_assert_irqs_disabled() do { } while (0)
634 # define lockdep_assert_in_irq() do { } while (0)
635 
636 # define lockdep_assert_preemption_enabled() do { } while (0)
637 # define lockdep_assert_preemption_disabled() do { } while (0)
638 # define lockdep_assert_in_softirq() do { } while (0)
639 #endif
640 
641 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
642 
643 # define lockdep_assert_RT_in_threaded_ctx() do {			\
644 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
645 			  lockdep_hardirq_context() &&			\
646 			  !(current->hardirq_threaded || current->irq_config),	\
647 			  "Not in threaded context on PREEMPT_RT as expected\n");	\
648 } while (0)
649 
650 #else
651 
652 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
653 
654 #endif
655 
656 #ifdef CONFIG_LOCKDEP
657 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
658 #else
659 static inline void
lockdep_rcu_suspicious(const char * file,const int line,const char * s)660 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
661 {
662 }
663 #endif
664 
665 #endif /* __LINUX_LOCKDEP_H */
666