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 #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
  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
 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, LD_WAIT_INV, LD_LOCK_NORMAL);
 192 }
 193
 194 static inline void
 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
 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_waits(&(lock)->dep_map, #key, key, 0,  \
 215                                (lock)->dep_map.wait_type_inner, \
 216                                (lock)->dep_map.wait_type_outer)
 217
 218 #define lockdep_set_class_and_name(lock, key, name)             \
 219         lockdep_init_map_waits(&(lock)->dep_map, name, key, 0,  \
 220                                (lock)->dep_map.wait_type_inner, \
 221                                (lock)->dep_map.wait_type_outer)
 222
 223 #define lockdep_set_class_and_subclass(lock, key, sub)          \
 224         lockdep_init_map_waits(&(lock)->dep_map, #key, key, sub,\
 225                                (lock)->dep_map.wait_type_inner, \
 226                                (lock)->dep_map.wait_type_outer)
 227
 228 #define lockdep_set_subclass(lock, sub)                                 \
 229         lockdep_init_map_waits(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
 230                                (lock)->dep_map.wait_type_inner,         \
 231                                (lock)->dep_map.wait_type_outer)
 232
 233 #define lockdep_set_novalidate_class(lock) \
 234         lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
 235
 236 /*
 237  * Compare locking classes
 238  */
 239 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)
 240
 241 static inline int lockdep_match_key(struct lockdep_map *lock,
 242                                     struct lock_class_key *key)
 243 {
 244         return lock->key == key;
 245 }
 246
 247 /*
 248  * Acquire a lock.
 249  *
 250  * Values for "read":
 251  *
 252  *   0: exclusive (write) acquire
 253  *   1: read-acquire (no recursion allowed)
 254  *   2: read-acquire with same-instance recursion allowed
 255  *
 256  * Values for check:
 257  *
 258  *   0: simple checks (freeing, held-at-exit-time, etc.)
 259  *   1: full validation
 260  */
 261 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 262                          int trylock, int read, int check,
 263                          struct lockdep_map *nest_lock, unsigned long ip);
 264
 265 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
 266
 267 /* lock_is_held_type() returns */
 268 #define LOCK_STATE_UNKNOWN      -1
 269 #define LOCK_STATE_NOT_HELD     0
 270 #define LOCK_STATE_HELD         1
 271
 272 /*
 273  * Same "read" as for lock_acquire(), except -1 means any.
 274  */
 275 extern int lock_is_held_type(const struct lockdep_map *lock, int read);
 276
 277 static inline int lock_is_held(const struct lockdep_map *lock)
 278 {
 279         return lock_is_held_type(lock, -1);
 280 }
 281
 282 #define lockdep_is_held(lock)           lock_is_held(&(lock)->dep_map)
 283 #define lockdep_is_held_type(lock, r)   lock_is_held_type(&(lock)->dep_map, (r))
 284
 285 extern void lock_set_class(struct lockdep_map *lock, const char *name,
 286                            struct lock_class_key *key, unsigned int subclass,
 287                            unsigned long ip);
 288
 289 static inline void lock_set_subclass(struct lockdep_map *lock,
 290                 unsigned int subclass, unsigned long ip)
 291 {
 292         lock_set_class(lock, lock->name, lock->key, subclass, ip);
 293 }
 294
 295 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
 296
 297 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
 298
 299 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
 300 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
 301 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 302
 303 #define lockdep_depth(tsk)      (debug_locks ? (tsk)->lockdep_depth : 0)
 304
 305 #define lockdep_assert(cond)            \
 306         do { WARN_ON(debug_locks && !(cond)); } while (0)
 307
 308 #define lockdep_assert_once(cond)       \
 309         do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
 310
 311 #define lockdep_assert_held(l)          \
 312         lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
 313
 314 #define lockdep_assert_not_held(l)      \
 315         lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
 316
 317 #define lockdep_assert_held_write(l)    \
 318         lockdep_assert(lockdep_is_held_type(l, 0))
 319
 320 #define lockdep_assert_held_read(l)     \
 321         lockdep_assert(lockdep_is_held_type(l, 1))
 322
 323 #define lockdep_assert_held_once(l)             \
 324         lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
 325
 326 #define lockdep_assert_none_held_once()         \
 327         lockdep_assert_once(!current->lockdep_depth)
 328
 329 #define lockdep_recursing(tsk)  ((tsk)->lockdep_recursion)
 330
 331 #define lockdep_pin_lock(l)     lock_pin_lock(&(l)->dep_map)
 332 #define lockdep_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c))
 333 #define lockdep_unpin_lock(l,c) lock_unpin_lock(&(l)->dep_map, (c))
 334
 335 #else /* !CONFIG_LOCKDEP */
 336
 337 static inline void lockdep_init_task(struct task_struct *task)
 338 {
 339 }
 340
 341 static inline void lockdep_off(void)
 342 {
 343 }
 344
 345 static inline void lockdep_on(void)
 346 {
 347 }
 348
 349 static inline void lockdep_set_selftest_task(struct task_struct *task)
 350 {
 351 }
 352
 353 # define lock_acquire(l, s, t, r, c, n, i)      do { } while (0)
 354 # define lock_release(l, i)                     do { } while (0)
 355 # define lock_downgrade(l, i)                   do { } while (0)
 356 # define lock_set_class(l, n, k, s, i)          do { } while (0)
 357 # define lock_set_subclass(l, s, i)             do { } while (0)
 358 # define lockdep_init()                         do { } while (0)
 359 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
 360                 do { (void)(name); (void)(key); } while (0)
 361 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
 362                 do { (void)(name); (void)(key); } while (0)
 363 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
 364                 do { (void)(name); (void)(key); } while (0)
 365 # define lockdep_init_map(lock, name, key, sub) \
 366                 do { (void)(name); (void)(key); } while (0)
 367 # define lockdep_set_class(lock, key)           do { (void)(key); } while (0)
 368 # define lockdep_set_class_and_name(lock, key, name) \
 369                 do { (void)(key); (void)(name); } while (0)
 370 #define lockdep_set_class_and_subclass(lock, key, sub) \
 371                 do { (void)(key); } while (0)
 372 #define lockdep_set_subclass(lock, sub)         do { } while (0)
 373
 374 #define lockdep_set_novalidate_class(lock) do { } while (0)
 375
 376 /*
 377  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
 378  * case since the result is not well defined and the caller should rather
 379  * #ifdef the call himself.
 380  */
 381
 382 # define lockdep_reset()                do { debug_locks = 1; } while (0)
 383 # define lockdep_free_key_range(start, size)    do { } while (0)
 384 # define lockdep_sys_exit()                     do { } while (0)
 385
 386 static inline void lockdep_register_key(struct lock_class_key *key)
 387 {
 388 }
 389
 390 static inline void lockdep_unregister_key(struct lock_class_key *key)
 391 {
 392 }
 393
 394 #define lockdep_depth(tsk)      (0)
 395
 396 /*
 397  * Dummy forward declarations, allow users to write less ifdef-y code
 398  * and depend on dead code elimination.
 399  */
 400 extern int lock_is_held(const void *);
 401 extern int lockdep_is_held(const void *);
 402 #define lockdep_is_held_type(l, r)              (1)
 403
 404 #define lockdep_assert(c)                       do { } while (0)
 405 #define lockdep_assert_once(c)                  do { } while (0)
 406
 407 #define lockdep_assert_held(l)                  do { (void)(l); } while (0)
 408 #define lockdep_assert_not_held(l)              do { (void)(l); } while (0)
 409 #define lockdep_assert_held_write(l)            do { (void)(l); } while (0)
 410 #define lockdep_assert_held_read(l)             do { (void)(l); } while (0)
 411 #define lockdep_assert_held_once(l)             do { (void)(l); } while (0)
 412 #define lockdep_assert_none_held_once() do { } while (0)
 413
 414 #define lockdep_recursing(tsk)                  (0)
 415
 416 #define NIL_COOKIE (struct pin_cookie){ }
 417
 418 #define lockdep_pin_lock(l)                     ({ struct pin_cookie cookie = { }; cookie; })
 419 #define lockdep_repin_lock(l, c)                do { (void)(l); (void)(c); } while (0)
 420 #define lockdep_unpin_lock(l, c)                do { (void)(l); (void)(c); } while (0)
 421
 422 #endif /* !LOCKDEP */
 423
 424 enum xhlock_context_t {
 425         XHLOCK_HARD,
 426         XHLOCK_SOFT,
 427         XHLOCK_CTX_NR,
 428 };
 429
 430 #define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
 431 /*
 432  * To initialize a lockdep_map statically use this macro.
 433  * Note that _name must not be NULL.
 434  */
 435 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
 436         { .name = (_name), .key = (void *)(_key), }
 437
 438 static inline void lockdep_invariant_state(bool force) {}
 439 static inline void lockdep_free_task(struct task_struct *task) {}
 440
 441 #ifdef CONFIG_LOCK_STAT
 442
 443 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
 444 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
 445
 446 #define LOCK_CONTENDED(_lock, try, lock)                        \
 447 do {                                                            \
 448         if (!try(_lock)) {                                      \
 449                 lock_contended(&(_lock)->dep_map, _RET_IP_);    \
 450                 lock(_lock);                                    \
 451         }                                                       \
 452         lock_acquired(&(_lock)->dep_map, _RET_IP_);                     \
 453 } while (0)
 454
 455 #define LOCK_CONTENDED_RETURN(_lock, try, lock)                 \
 456 ({                                                              \
 457         int ____err = 0;                                        \
 458         if (!try(_lock)) {                                      \
 459                 lock_contended(&(_lock)->dep_map, _RET_IP_);    \
 460                 ____err = lock(_lock);                          \
 461         }                                                       \
 462         if (!____err)                                           \
 463                 lock_acquired(&(_lock)->dep_map, _RET_IP_);     \
 464         ____err;                                                \
 465 })
 466
 467 #else /* CONFIG_LOCK_STAT */
 468
 469 #define lock_contended(lockdep_map, ip) do {} while (0)
 470 #define lock_acquired(lockdep_map, ip) do {} while (0)
 471
 472 #define LOCK_CONTENDED(_lock, try, lock) \
 473         lock(_lock)
 474
 475 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
 476         lock(_lock)
 477
 478 #endif /* CONFIG_LOCK_STAT */
 479
 480 #ifdef CONFIG_PROVE_LOCKING
 481 extern void print_irqtrace_events(struct task_struct *curr);
 482 #else
 483 static inline void print_irqtrace_events(struct task_struct *curr)
 484 {
 485 }
 486 #endif
 487
 488 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
 489 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
 490 extern unsigned int force_read_lock_recursive;
 491 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 492 #define force_read_lock_recursive 0
 493 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 494
 495 #ifdef CONFIG_LOCKDEP
 496 extern bool read_lock_is_recursive(void);
 497 #else /* CONFIG_LOCKDEP */
 498 /* If !LOCKDEP, the value is meaningless */
 499 #define read_lock_is_recursive() 0
 500 #endif
 501
 502 /*
 503  * For trivial one-depth nesting of a lock-class, the following
 504  * global define can be used. (Subsystems with multiple levels
 505  * of nesting should define their own lock-nesting subclasses.)
 506  */
 507 #define SINGLE_DEPTH_NESTING                    1
 508
 509 /*
 510  * Map the dependency ops to NOP or to real lockdep ops, depending
 511  * on the per lock-class debug mode:
 512  */
 513
 514 #define lock_acquire_exclusive(l, s, t, n, i)           lock_acquire(l, s, t, 0, 1, n, i)
 515 #define lock_acquire_shared(l, s, t, n, i)              lock_acquire(l, s, t, 1, 1, n, i)
 516 #define lock_acquire_shared_recursive(l, s, t, n, i)    lock_acquire(l, s, t, 2, 1, n, i)
 517
 518 #define spin_acquire(l, s, t, i)                lock_acquire_exclusive(l, s, t, NULL, i)
 519 #define spin_acquire_nest(l, s, t, n, i)        lock_acquire_exclusive(l, s, t, n, i)
 520 #define spin_release(l, i)                      lock_release(l, i)
 521
 522 #define rwlock_acquire(l, s, t, i)              lock_acquire_exclusive(l, s, t, NULL, i)
 523 #define rwlock_acquire_read(l, s, t, i)                                 \
 524 do {                                                                    \
 525         if (read_lock_is_recursive())                                   \
 526                 lock_acquire_shared_recursive(l, s, t, NULL, i);        \
 527         else                                                            \
 528                 lock_acquire_shared(l, s, t, NULL, i);                  \
 529 } while (0)
 530
 531 #define rwlock_release(l, i)                    lock_release(l, i)
 532
 533 #define seqcount_acquire(l, s, t, i)            lock_acquire_exclusive(l, s, t, NULL, i)
 534 #define seqcount_acquire_read(l, s, t, i)       lock_acquire_shared_recursive(l, s, t, NULL, i)
 535 #define seqcount_release(l, i)                  lock_release(l, i)
 536
 537 #define mutex_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 538 #define mutex_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 539 #define mutex_release(l, i)                     lock_release(l, i)
 540
 541 #define rwsem_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 542 #define rwsem_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 543 #define rwsem_acquire_read(l, s, t, i)          lock_acquire_shared(l, s, t, NULL, i)
 544 #define rwsem_release(l, i)                     lock_release(l, i)
 545
 546 #define lock_map_acquire(l)                     lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
 547 #define lock_map_acquire_read(l)                lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
 548 #define lock_map_acquire_tryread(l)             lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
 549 #define lock_map_release(l)                     lock_release(l, _THIS_IP_)
 550
 551 #ifdef CONFIG_PROVE_LOCKING
 552 # define might_lock(lock)                                               \
 553 do {                                                                    \
 554         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 555         lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);    \
 556         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 557 } while (0)
 558 # define might_lock_read(lock)                                          \
 559 do {                                                                    \
 560         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 561         lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);    \
 562         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 563 } while (0)
 564 # define might_lock_nested(lock, subclass)                              \
 565 do {                                                                    \
 566         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 567         lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,         \
 568                      _THIS_IP_);                                        \
 569         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 570 } while (0)
 571
 572 DECLARE_PER_CPU(int, hardirqs_enabled);
 573 DECLARE_PER_CPU(int, hardirq_context);
 574 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
 575
 576 #define __lockdep_enabled       (debug_locks && !this_cpu_read(lockdep_recursion))
 577
 578 #define lockdep_assert_irqs_enabled()                                   \
 579 do {                                                                    \
 580         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
 581 } while (0)
 582
 583 #define lockdep_assert_irqs_disabled()                                  \
 584 do {                                                                    \
 585         WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
 586 } while (0)
 587
 588 #define lockdep_assert_in_irq()                                         \
 589 do {                                                                    \
 590         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
 591 } while (0)
 592
 593 #define lockdep_assert_preemption_enabled()                             \
 594 do {                                                                    \
 595         WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)   &&              \
 596                      __lockdep_enabled                  &&              \
 597                      (preempt_count() != 0              ||              \
 598                       !this_cpu_read(hardirqs_enabled)));               \
 599 } while (0)
 600
 601 #define lockdep_assert_preemption_disabled()                            \
 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 /*
 610  * Acceptable for protecting per-CPU resources accessed from BH.
 611  * Much like in_softirq() - semantics are ambiguous, use carefully.
 612  */
 613 #define lockdep_assert_in_softirq()                                     \
 614 do {                                                                    \
 615         WARN_ON_ONCE(__lockdep_enabled                  &&              \
 616                      (!in_softirq() || in_irq() || in_nmi()));          \
 617 } while (0)
 618
 619 #else
 620 # define might_lock(lock) do { } while (0)
 621 # define might_lock_read(lock) do { } while (0)
 622 # define might_lock_nested(lock, subclass) do { } while (0)
 623
 624 # define lockdep_assert_irqs_enabled() do { } while (0)
 625 # define lockdep_assert_irqs_disabled() do { } while (0)
 626 # define lockdep_assert_in_irq() do { } while (0)
 627
 628 # define lockdep_assert_preemption_enabled() do { } while (0)
 629 # define lockdep_assert_preemption_disabled() do { } while (0)
 630 # define lockdep_assert_in_softirq() do { } while (0)
 631 #endif
 632
 633 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
 634
 635 # define lockdep_assert_RT_in_threaded_ctx() do {                       \
 636                 WARN_ONCE(debug_locks && !current->lockdep_recursion && \
 637                           lockdep_hardirq_context() &&                  \
 638                           !(current->hardirq_threaded || current->irq_config),  \
 639                           "Not in threaded context on PREEMPT_RT as expected\n");       \
 640 } while (0)
 641
 642 #else
 643
 644 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
 645
 646 #endif
 647
 648 #ifdef CONFIG_LOCKDEP
 649 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
 650 #else
 651 static inline void
 652 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 653 {
 654 }
 655 #endif
 656
 657 #endif /* __LINUX_LOCKDEP_H */