include/linux/lockdep.h

   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 /* 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 #define lockdep_recursing(tsk)  ((tsk)->lockdep_recursion)
 334
 335 #define lockdep_pin_lock(l)     lock_pin_lock(&(l)->dep_map)
 336 #define lockdep_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c))
 337 #define lockdep_unpin_lock(l,c) lock_unpin_lock(&(l)->dep_map, (c))
 338
 339 #else /* !CONFIG_LOCKDEP */
 340
 341 static inline void lockdep_init_task(struct task_struct *task)
 342 {
 343 }
 344
 345 static inline void lockdep_off(void)
 346 {
 347 }
 348
 349 static inline void lockdep_on(void)
 350 {
 351 }
 352
 353 static inline void lockdep_set_selftest_task(struct task_struct *task)
 354 {
 355 }
 356
 357 # define lock_acquire(l, s, t, r, c, n, i)      do { } while (0)
 358 # define lock_release(l, i)                     do { } while (0)
 359 # define lock_downgrade(l, i)                   do { } while (0)
 360 # define lock_set_class(l, n, k, s, i)          do { } while (0)
 361 # define lock_set_subclass(l, s, i)             do { } while (0)
 362 # define lockdep_init()                         do { } while (0)
 363 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
 364                 do { (void)(name); (void)(key); } while (0)
 365 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
 366                 do { (void)(name); (void)(key); } while (0)
 367 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
 368                 do { (void)(name); (void)(key); } while (0)
 369 # define lockdep_init_map(lock, name, key, sub) \
 370                 do { (void)(name); (void)(key); } while (0)
 371 # define lockdep_set_class(lock, key)           do { (void)(key); } while (0)
 372 # define lockdep_set_class_and_name(lock, key, name) \
 373                 do { (void)(key); (void)(name); } while (0)
 374 #define lockdep_set_class_and_subclass(lock, key, sub) \
 375                 do { (void)(key); } while (0)
 376 #define lockdep_set_subclass(lock, sub)         do { } while (0)
 377
 378 #define lockdep_set_novalidate_class(lock) do { } while (0)
 379
 380 /*
 381  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
 382  * case since the result is not well defined and the caller should rather
 383  * #ifdef the call himself.
 384  */
 385
 386 # define lockdep_reset()                do { debug_locks = 1; } while (0)
 387 # define lockdep_free_key_range(start, size)    do { } while (0)
 388 # define lockdep_sys_exit()                     do { } while (0)
 389
 390 static inline void lockdep_register_key(struct lock_class_key *key)
 391 {
 392 }
 393
 394 static inline void lockdep_unregister_key(struct lock_class_key *key)
 395 {
 396 }
 397
 398 #define lockdep_depth(tsk)      (0)
 399
 400 /*
 401  * Dummy forward declarations, allow users to write less ifdef-y code
 402  * and depend on dead code elimination.
 403  */
 404 extern int lock_is_held(const void *);
 405 extern int lockdep_is_held(const void *);
 406 #define lockdep_is_held_type(l, r)              (1)
 407
 408 #define lockdep_assert(c)                       do { } while (0)
 409 #define lockdep_assert_once(c)                  do { } while (0)
 410
 411 #define lockdep_assert_held(l)                  do { (void)(l); } while (0)
 412 #define lockdep_assert_not_held(l)              do { (void)(l); } while (0)
 413 #define lockdep_assert_held_write(l)            do { (void)(l); } while (0)
 414 #define lockdep_assert_held_read(l)             do { (void)(l); } while (0)
 415 #define lockdep_assert_held_once(l)             do { (void)(l); } while (0)
 416 #define lockdep_assert_none_held_once() do { } while (0)
 417
 418 #define lockdep_recursing(tsk)                  (0)
 419
 420 #define NIL_COOKIE (struct pin_cookie){ }
 421
 422 #define lockdep_pin_lock(l)                     ({ struct pin_cookie cookie = { }; cookie; })
 423 #define lockdep_repin_lock(l, c)                do { (void)(l); (void)(c); } while (0)
 424 #define lockdep_unpin_lock(l, c)                do { (void)(l); (void)(c); } while (0)
 425
 426 #endif /* !LOCKDEP */
 427
 428 enum xhlock_context_t {
 429         XHLOCK_HARD,
 430         XHLOCK_SOFT,
 431         XHLOCK_CTX_NR,
 432 };
 433
 434 #define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
 435 /*
 436  * To initialize a lockdep_map statically use this macro.
 437  * Note that _name must not be NULL.
 438  */
 439 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
 440         { .name = (_name), .key = (void *)(_key), }
 441
 442 static inline void lockdep_invariant_state(bool force) {}
 443 static inline void lockdep_free_task(struct task_struct *task) {}
 444
 445 #ifdef CONFIG_LOCK_STAT
 446
 447 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
 448 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
 449
 450 #define LOCK_CONTENDED(_lock, try, lock)                        \
 451 do {                                                            \
 452         if (!try(_lock)) {                                      \
 453                 lock_contended(&(_lock)->dep_map, _RET_IP_);    \
 454                 lock(_lock);                                    \
 455         }                                                       \
 456         lock_acquired(&(_lock)->dep_map, _RET_IP_);                     \
 457 } while (0)
 458
 459 #define LOCK_CONTENDED_RETURN(_lock, try, lock)                 \
 460 ({                                                              \
 461         int ____err = 0;                                        \
 462         if (!try(_lock)) {                                      \
 463                 lock_contended(&(_lock)->dep_map, _RET_IP_);    \
 464                 ____err = lock(_lock);                          \
 465         }                                                       \
 466         if (!____err)                                           \
 467                 lock_acquired(&(_lock)->dep_map, _RET_IP_);     \
 468         ____err;                                                \
 469 })
 470
 471 #else /* CONFIG_LOCK_STAT */
 472
 473 #define lock_contended(lockdep_map, ip) do {} while (0)
 474 #define lock_acquired(lockdep_map, ip) do {} while (0)
 475
 476 #define LOCK_CONTENDED(_lock, try, lock) \
 477         lock(_lock)
 478
 479 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
 480         lock(_lock)
 481
 482 #endif /* CONFIG_LOCK_STAT */
 483
 484 #ifdef CONFIG_LOCKDEP
 485
 486 /*
 487  * On lockdep we dont want the hand-coded irq-enable of
 488  * _raw_*_lock_flags() code, because lockdep assumes
 489  * that interrupts are not re-enabled during lock-acquire:
 490  */
 491 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
 492         LOCK_CONTENDED((_lock), (try), (lock))
 493
 494 #else /* CONFIG_LOCKDEP */
 495
 496 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
 497         lockfl((_lock), (flags))
 498
 499 #endif /* CONFIG_LOCKDEP */
 500
 501 #ifdef CONFIG_PROVE_LOCKING
 502 extern void print_irqtrace_events(struct task_struct *curr);
 503 #else
 504 static inline void print_irqtrace_events(struct task_struct *curr)
 505 {
 506 }
 507 #endif
 508
 509 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
 510 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
 511 extern unsigned int force_read_lock_recursive;
 512 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 513 #define force_read_lock_recursive 0
 514 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 515
 516 #ifdef CONFIG_LOCKDEP
 517 extern bool read_lock_is_recursive(void);
 518 #else /* CONFIG_LOCKDEP */
 519 /* If !LOCKDEP, the value is meaningless */
 520 #define read_lock_is_recursive() 0
 521 #endif
 522
 523 /*
 524  * For trivial one-depth nesting of a lock-class, the following
 525  * global define can be used. (Subsystems with multiple levels
 526  * of nesting should define their own lock-nesting subclasses.)
 527  */
 528 #define SINGLE_DEPTH_NESTING                    1
 529
 530 /*
 531  * Map the dependency ops to NOP or to real lockdep ops, depending
 532  * on the per lock-class debug mode:
 533  */
 534
 535 #define lock_acquire_exclusive(l, s, t, n, i)           lock_acquire(l, s, t, 0, 1, n, i)
 536 #define lock_acquire_shared(l, s, t, n, i)              lock_acquire(l, s, t, 1, 1, n, i)
 537 #define lock_acquire_shared_recursive(l, s, t, n, i)    lock_acquire(l, s, t, 2, 1, n, i)
 538
 539 #define spin_acquire(l, s, t, i)                lock_acquire_exclusive(l, s, t, NULL, i)
 540 #define spin_acquire_nest(l, s, t, n, i)        lock_acquire_exclusive(l, s, t, n, i)
 541 #define spin_release(l, i)                      lock_release(l, i)
 542
 543 #define rwlock_acquire(l, s, t, i)              lock_acquire_exclusive(l, s, t, NULL, i)
 544 #define rwlock_acquire_read(l, s, t, i)                                 \
 545 do {                                                                    \
 546         if (read_lock_is_recursive())                                   \
 547                 lock_acquire_shared_recursive(l, s, t, NULL, i);        \
 548         else                                                            \
 549                 lock_acquire_shared(l, s, t, NULL, i);                  \
 550 } while (0)
 551
 552 #define rwlock_release(l, i)                    lock_release(l, i)
 553
 554 #define seqcount_acquire(l, s, t, i)            lock_acquire_exclusive(l, s, t, NULL, i)
 555 #define seqcount_acquire_read(l, s, t, i)       lock_acquire_shared_recursive(l, s, t, NULL, i)
 556 #define seqcount_release(l, i)                  lock_release(l, i)
 557
 558 #define mutex_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 559 #define mutex_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 560 #define mutex_release(l, i)                     lock_release(l, i)
 561
 562 #define rwsem_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 563 #define rwsem_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 564 #define rwsem_acquire_read(l, s, t, i)          lock_acquire_shared(l, s, t, NULL, i)
 565 #define rwsem_release(l, i)                     lock_release(l, i)
 566
 567 #define lock_map_acquire(l)                     lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
 568 #define lock_map_acquire_read(l)                lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
 569 #define lock_map_acquire_tryread(l)             lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
 570 #define lock_map_release(l)                     lock_release(l, _THIS_IP_)
 571
 572 #ifdef CONFIG_PROVE_LOCKING
 573 # define might_lock(lock)                                               \
 574 do {                                                                    \
 575         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 576         lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);    \
 577         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 578 } while (0)
 579 # define might_lock_read(lock)                                          \
 580 do {                                                                    \
 581         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 582         lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);    \
 583         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 584 } while (0)
 585 # define might_lock_nested(lock, subclass)                              \
 586 do {                                                                    \
 587         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 588         lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,         \
 589                      _THIS_IP_);                                        \
 590         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 591 } while (0)
 592
 593 DECLARE_PER_CPU(int, hardirqs_enabled);
 594 DECLARE_PER_CPU(int, hardirq_context);
 595 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
 596
 597 #define __lockdep_enabled       (debug_locks && !this_cpu_read(lockdep_recursion))
 598
 599 #define lockdep_assert_irqs_enabled()                                   \
 600 do {                                                                    \
 601         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
 602 } while (0)
 603
 604 #define lockdep_assert_irqs_disabled()                                  \
 605 do {                                                                    \
 606         WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
 607 } while (0)
 608
 609 #define lockdep_assert_in_irq()                                         \
 610 do {                                                                    \
 611         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
 612 } while (0)
 613
 614 #define lockdep_assert_preemption_enabled()                             \
 615 do {                                                                    \
 616         WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)   &&              \
 617                      __lockdep_enabled                  &&              \
 618                      (preempt_count() != 0              ||              \
 619                       !this_cpu_read(hardirqs_enabled)));               \
 620 } while (0)
 621
 622 #define lockdep_assert_preemption_disabled()                            \
 623 do {                                                                    \
 624         WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)   &&              \
 625                      __lockdep_enabled                  &&              \
 626                      (preempt_count() == 0              &&              \
 627                       this_cpu_read(hardirqs_enabled)));                \
 628 } while (0)
 629
 630 /*
 631  * Acceptable for protecting per-CPU resources accessed from BH.
 632  * Much like in_softirq() - semantics are ambiguous, use carefully.
 633  */
 634 #define lockdep_assert_in_softirq()                                     \
 635 do {                                                                    \
 636         WARN_ON_ONCE(__lockdep_enabled                  &&              \
 637                      (!in_softirq() || in_irq() || in_nmi()));          \
 638 } while (0)
 639
 640 #else
 641 # define might_lock(lock) do { } while (0)
 642 # define might_lock_read(lock) do { } while (0)
 643 # define might_lock_nested(lock, subclass) do { } while (0)
 644
 645 # define lockdep_assert_irqs_enabled() do { } while (0)
 646 # define lockdep_assert_irqs_disabled() do { } while (0)
 647 # define lockdep_assert_in_irq() do { } while (0)
 648
 649 # define lockdep_assert_preemption_enabled() do { } while (0)
 650 # define lockdep_assert_preemption_disabled() do { } while (0)
 651 # define lockdep_assert_in_softirq() do { } while (0)
 652 #endif
 653
 654 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
 655
 656 # define lockdep_assert_RT_in_threaded_ctx() do {                       \
 657                 WARN_ONCE(debug_locks && !current->lockdep_recursion && \
 658                           lockdep_hardirq_context() &&                  \
 659                           !(current->hardirq_threaded || current->irq_config),  \
 660                           "Not in threaded context on PREEMPT_RT as expected\n");       \
 661 } while (0)
 662
 663 #else
 664
 665 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
 666
 667 #endif
 668
 669 #ifdef CONFIG_LOCKDEP
 670 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
 671 #else
 672 static inline void
 673 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 674 {
 675 }
 676 #endif
 677
 678 #endif /* __LINUX_LOCKDEP_H */