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 sync:1;
 138         unsigned int references:11;                                     /* 32 bits */
 139         unsigned int pin_count;
 140 };
 141
 142 /*
 143  * Initialization, self-test and debugging-output methods:
 144  */
 145 extern void lockdep_init(void);
 146 extern void lockdep_reset(void);
 147 extern void lockdep_reset_lock(struct lockdep_map *lock);
 148 extern void lockdep_free_key_range(void *start, unsigned long size);
 149 extern asmlinkage void lockdep_sys_exit(void);
 150 extern void lockdep_set_selftest_task(struct task_struct *task);
 151
 152 extern void lockdep_init_task(struct task_struct *task);
 153
 154 /*
 155  * Split the recursion counter in two to readily detect 'off' vs recursion.
 156  */
 157 #define LOCKDEP_RECURSION_BITS  16
 158 #define LOCKDEP_OFF             (1U << LOCKDEP_RECURSION_BITS)
 159 #define LOCKDEP_RECURSION_MASK  (LOCKDEP_OFF - 1)
 160
 161 /*
 162  * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due
 163  * to header dependencies.
 164  */
 165
 166 #define lockdep_off()                                   \
 167 do {                                                    \
 168         current->lockdep_recursion += LOCKDEP_OFF;      \
 169 } while (0)
 170
 171 #define lockdep_on()                                    \
 172 do {                                                    \
 173         current->lockdep_recursion -= LOCKDEP_OFF;      \
 174 } while (0)
 175
 176 extern void lockdep_register_key(struct lock_class_key *key);
 177 extern void lockdep_unregister_key(struct lock_class_key *key);
 178
 179 /*
 180  * These methods are used by specific locking variants (spinlocks,
 181  * rwlocks, mutexes and rwsems) to pass init/acquire/release events
 182  * to lockdep:
 183  */
 184
 185 extern void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
 186         struct lock_class_key *key, int subclass, u8 inner, u8 outer, u8 lock_type);
 187
 188 static inline void
 189 lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
 190                        struct lock_class_key *key, int subclass, u8 inner, u8 outer)
 191 {
 192         lockdep_init_map_type(lock, name, key, subclass, inner, outer, LD_LOCK_NORMAL);
 193 }
 194
 195 static inline void
 196 lockdep_init_map_wait(struct lockdep_map *lock, const char *name,
 197                       struct lock_class_key *key, int subclass, u8 inner)
 198 {
 199         lockdep_init_map_waits(lock, name, key, subclass, inner, LD_WAIT_INV);
 200 }
 201
 202 static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,
 203                              struct lock_class_key *key, int subclass)
 204 {
 205         lockdep_init_map_wait(lock, name, key, subclass, LD_WAIT_INV);
 206 }
 207
 208 /*
 209  * Reinitialize a lock key - for cases where there is special locking or
 210  * special initialization of locks so that the validator gets the scope
 211  * of dependencies wrong: they are either too broad (they need a class-split)
 212  * or they are too narrow (they suffer from a false class-split):
 213  */
 214 #define lockdep_set_class(lock, key)                            \
 215         lockdep_init_map_type(&(lock)->dep_map, #key, key, 0,   \
 216                               (lock)->dep_map.wait_type_inner,  \
 217                               (lock)->dep_map.wait_type_outer,  \
 218                               (lock)->dep_map.lock_type)
 219
 220 #define lockdep_set_class_and_name(lock, key, name)             \
 221         lockdep_init_map_type(&(lock)->dep_map, name, key, 0,   \
 222                               (lock)->dep_map.wait_type_inner,  \
 223                               (lock)->dep_map.wait_type_outer,  \
 224                               (lock)->dep_map.lock_type)
 225
 226 #define lockdep_set_class_and_subclass(lock, key, sub)          \
 227         lockdep_init_map_type(&(lock)->dep_map, #key, key, sub, \
 228                               (lock)->dep_map.wait_type_inner,  \
 229                               (lock)->dep_map.wait_type_outer,  \
 230                               (lock)->dep_map.lock_type)
 231
 232 #define lockdep_set_subclass(lock, sub)                                 \
 233         lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
 234                               (lock)->dep_map.wait_type_inner,          \
 235                               (lock)->dep_map.wait_type_outer,          \
 236                               (lock)->dep_map.lock_type)
 237
 238 #define lockdep_set_novalidate_class(lock) \
 239         lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
 240
 241 /*
 242  * Compare locking classes
 243  */
 244 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)
 245
 246 static inline int lockdep_match_key(struct lockdep_map *lock,
 247                                     struct lock_class_key *key)
 248 {
 249         return lock->key == key;
 250 }
 251
 252 /*
 253  * Acquire a lock.
 254  *
 255  * Values for "read":
 256  *
 257  *   0: exclusive (write) acquire
 258  *   1: read-acquire (no recursion allowed)
 259  *   2: read-acquire with same-instance recursion allowed
 260  *
 261  * Values for check:
 262  *
 263  *   0: simple checks (freeing, held-at-exit-time, etc.)
 264  *   1: full validation
 265  */
 266 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 267                          int trylock, int read, int check,
 268                          struct lockdep_map *nest_lock, unsigned long ip);
 269
 270 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
 271
 272 extern void lock_sync(struct lockdep_map *lock, unsigned int subclass,
 273                       int read, int check, struct lockdep_map *nest_lock,
 274                       unsigned long ip);
 275
 276 /* lock_is_held_type() returns */
 277 #define LOCK_STATE_UNKNOWN      -1
 278 #define LOCK_STATE_NOT_HELD     0
 279 #define LOCK_STATE_HELD         1
 280
 281 /*
 282  * Same "read" as for lock_acquire(), except -1 means any.
 283  */
 284 extern int lock_is_held_type(const struct lockdep_map *lock, int read);
 285
 286 static inline int lock_is_held(const struct lockdep_map *lock)
 287 {
 288         return lock_is_held_type(lock, -1);
 289 }
 290
 291 #define lockdep_is_held(lock)           lock_is_held(&(lock)->dep_map)
 292 #define lockdep_is_held_type(lock, r)   lock_is_held_type(&(lock)->dep_map, (r))
 293
 294 extern void lock_set_class(struct lockdep_map *lock, const char *name,
 295                            struct lock_class_key *key, unsigned int subclass,
 296                            unsigned long ip);
 297
 298 #define lock_set_novalidate_class(l, n, i) \
 299         lock_set_class(l, n, &__lockdep_no_validate__, 0, i)
 300
 301 static inline void lock_set_subclass(struct lockdep_map *lock,
 302                 unsigned int subclass, unsigned long ip)
 303 {
 304         lock_set_class(lock, lock->name, lock->key, subclass, ip);
 305 }
 306
 307 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
 308
 309 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
 310
 311 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
 312 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
 313 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 314
 315 #define lockdep_depth(tsk)      (debug_locks ? (tsk)->lockdep_depth : 0)
 316
 317 #define lockdep_assert(cond)            \
 318         do { WARN_ON(debug_locks && !(cond)); } while (0)
 319
 320 #define lockdep_assert_once(cond)       \
 321         do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
 322
 323 #define lockdep_assert_held(l)          \
 324         lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
 325
 326 #define lockdep_assert_not_held(l)      \
 327         lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
 328
 329 #define lockdep_assert_held_write(l)    \
 330         lockdep_assert(lockdep_is_held_type(l, 0))
 331
 332 #define lockdep_assert_held_read(l)     \
 333         lockdep_assert(lockdep_is_held_type(l, 1))
 334
 335 #define lockdep_assert_held_once(l)             \
 336         lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
 337
 338 #define lockdep_assert_none_held_once()         \
 339         lockdep_assert_once(!current->lockdep_depth)
 340
 341 #define lockdep_recursing(tsk)  ((tsk)->lockdep_recursion)
 342
 343 #define lockdep_pin_lock(l)     lock_pin_lock(&(l)->dep_map)
 344 #define lockdep_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c))
 345 #define lockdep_unpin_lock(l,c) lock_unpin_lock(&(l)->dep_map, (c))
 346
 347 #else /* !CONFIG_LOCKDEP */
 348
 349 static inline void lockdep_init_task(struct task_struct *task)
 350 {
 351 }
 352
 353 static inline void lockdep_off(void)
 354 {
 355 }
 356
 357 static inline void lockdep_on(void)
 358 {
 359 }
 360
 361 static inline void lockdep_set_selftest_task(struct task_struct *task)
 362 {
 363 }
 364
 365 # define lock_acquire(l, s, t, r, c, n, i)      do { } while (0)
 366 # define lock_release(l, i)                     do { } while (0)
 367 # define lock_downgrade(l, i)                   do { } while (0)
 368 # define lock_set_class(l, n, key, s, i)        do { (void)(key); } while (0)
 369 # define lock_set_novalidate_class(l, n, i)     do { } while (0)
 370 # define lock_set_subclass(l, s, i)             do { } while (0)
 371 # define lockdep_init()                         do { } while (0)
 372 # define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
 373                 do { (void)(name); (void)(key); } while (0)
 374 # define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
 375                 do { (void)(name); (void)(key); } while (0)
 376 # define lockdep_init_map_wait(lock, name, key, sub, inner) \
 377                 do { (void)(name); (void)(key); } while (0)
 378 # define lockdep_init_map(lock, name, key, sub) \
 379                 do { (void)(name); (void)(key); } while (0)
 380 # define lockdep_set_class(lock, key)           do { (void)(key); } while (0)
 381 # define lockdep_set_class_and_name(lock, key, name) \
 382                 do { (void)(key); (void)(name); } while (0)
 383 #define lockdep_set_class_and_subclass(lock, key, sub) \
 384                 do { (void)(key); } while (0)
 385 #define lockdep_set_subclass(lock, sub)         do { } while (0)
 386
 387 #define lockdep_set_novalidate_class(lock) do { } while (0)
 388
 389 /*
 390  * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
 391  * case since the result is not well defined and the caller should rather
 392  * #ifdef the call himself.
 393  */
 394
 395 # define lockdep_reset()                do { debug_locks = 1; } while (0)
 396 # define lockdep_free_key_range(start, size)    do { } while (0)
 397 # define lockdep_sys_exit()                     do { } while (0)
 398
 399 static inline void lockdep_register_key(struct lock_class_key *key)
 400 {
 401 }
 402
 403 static inline void lockdep_unregister_key(struct lock_class_key *key)
 404 {
 405 }
 406
 407 #define lockdep_depth(tsk)      (0)
 408
 409 /*
 410  * Dummy forward declarations, allow users to write less ifdef-y code
 411  * and depend on dead code elimination.
 412  */
 413 extern int lock_is_held(const void *);
 414 extern int lockdep_is_held(const void *);
 415 #define lockdep_is_held_type(l, r)              (1)
 416
 417 #define lockdep_assert(c)                       do { } while (0)
 418 #define lockdep_assert_once(c)                  do { } while (0)
 419
 420 #define lockdep_assert_held(l)                  do { (void)(l); } while (0)
 421 #define lockdep_assert_not_held(l)              do { (void)(l); } while (0)
 422 #define lockdep_assert_held_write(l)            do { (void)(l); } while (0)
 423 #define lockdep_assert_held_read(l)             do { (void)(l); } while (0)
 424 #define lockdep_assert_held_once(l)             do { (void)(l); } while (0)
 425 #define lockdep_assert_none_held_once() do { } while (0)
 426
 427 #define lockdep_recursing(tsk)                  (0)
 428
 429 #define NIL_COOKIE (struct pin_cookie){ }
 430
 431 #define lockdep_pin_lock(l)                     ({ struct pin_cookie cookie = { }; cookie; })
 432 #define lockdep_repin_lock(l, c)                do { (void)(l); (void)(c); } while (0)
 433 #define lockdep_unpin_lock(l, c)                do { (void)(l); (void)(c); } while (0)
 434
 435 #endif /* !LOCKDEP */
 436
 437 enum xhlock_context_t {
 438         XHLOCK_HARD,
 439         XHLOCK_SOFT,
 440         XHLOCK_CTX_NR,
 441 };
 442
 443 /*
 444  * To initialize a lockdep_map statically use this macro.
 445  * Note that _name must not be NULL.
 446  */
 447 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
 448         { .name = (_name), .key = (void *)(_key), }
 449
 450 static inline void lockdep_invariant_state(bool force) {}
 451 static inline void lockdep_free_task(struct task_struct *task) {}
 452
 453 #ifdef CONFIG_LOCK_STAT
 454
 455 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
 456 extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
 457
 458 #define LOCK_CONTENDED(_lock, try, lock)                        \
 459 do {                                                            \
 460         if (!try(_lock)) {                                      \
 461                 lock_contended(&(_lock)->dep_map, _RET_IP_);    \
 462                 lock(_lock);                                    \
 463         }                                                       \
 464         lock_acquired(&(_lock)->dep_map, _RET_IP_);                     \
 465 } while (0)
 466
 467 #define LOCK_CONTENDED_RETURN(_lock, try, lock)                 \
 468 ({                                                              \
 469         int ____err = 0;                                        \
 470         if (!try(_lock)) {                                      \
 471                 lock_contended(&(_lock)->dep_map, _RET_IP_);    \
 472                 ____err = lock(_lock);                          \
 473         }                                                       \
 474         if (!____err)                                           \
 475                 lock_acquired(&(_lock)->dep_map, _RET_IP_);     \
 476         ____err;                                                \
 477 })
 478
 479 #else /* CONFIG_LOCK_STAT */
 480
 481 #define lock_contended(lockdep_map, ip) do {} while (0)
 482 #define lock_acquired(lockdep_map, ip) do {} while (0)
 483
 484 #define LOCK_CONTENDED(_lock, try, lock) \
 485         lock(_lock)
 486
 487 #define LOCK_CONTENDED_RETURN(_lock, try, lock) \
 488         lock(_lock)
 489
 490 #endif /* CONFIG_LOCK_STAT */
 491
 492 #ifdef CONFIG_PROVE_LOCKING
 493 extern void print_irqtrace_events(struct task_struct *curr);
 494 #else
 495 static inline void print_irqtrace_events(struct task_struct *curr)
 496 {
 497 }
 498 #endif
 499
 500 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
 501 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
 502 extern unsigned int force_read_lock_recursive;
 503 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 504 #define force_read_lock_recursive 0
 505 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 506
 507 #ifdef CONFIG_LOCKDEP
 508 extern bool read_lock_is_recursive(void);
 509 #else /* CONFIG_LOCKDEP */
 510 /* If !LOCKDEP, the value is meaningless */
 511 #define read_lock_is_recursive() 0
 512 #endif
 513
 514 /*
 515  * For trivial one-depth nesting of a lock-class, the following
 516  * global define can be used. (Subsystems with multiple levels
 517  * of nesting should define their own lock-nesting subclasses.)
 518  */
 519 #define SINGLE_DEPTH_NESTING                    1
 520
 521 /*
 522  * Map the dependency ops to NOP or to real lockdep ops, depending
 523  * on the per lock-class debug mode:
 524  */
 525
 526 #define lock_acquire_exclusive(l, s, t, n, i)           lock_acquire(l, s, t, 0, 1, n, i)
 527 #define lock_acquire_shared(l, s, t, n, i)              lock_acquire(l, s, t, 1, 1, n, i)
 528 #define lock_acquire_shared_recursive(l, s, t, n, i)    lock_acquire(l, s, t, 2, 1, n, i)
 529
 530 #define spin_acquire(l, s, t, i)                lock_acquire_exclusive(l, s, t, NULL, i)
 531 #define spin_acquire_nest(l, s, t, n, i)        lock_acquire_exclusive(l, s, t, n, i)
 532 #define spin_release(l, i)                      lock_release(l, i)
 533
 534 #define rwlock_acquire(l, s, t, i)              lock_acquire_exclusive(l, s, t, NULL, i)
 535 #define rwlock_acquire_read(l, s, t, i)                                 \
 536 do {                                                                    \
 537         if (read_lock_is_recursive())                                   \
 538                 lock_acquire_shared_recursive(l, s, t, NULL, i);        \
 539         else                                                            \
 540                 lock_acquire_shared(l, s, t, NULL, i);                  \
 541 } while (0)
 542
 543 #define rwlock_release(l, i)                    lock_release(l, i)
 544
 545 #define seqcount_acquire(l, s, t, i)            lock_acquire_exclusive(l, s, t, NULL, i)
 546 #define seqcount_acquire_read(l, s, t, i)       lock_acquire_shared_recursive(l, s, t, NULL, i)
 547 #define seqcount_release(l, i)                  lock_release(l, i)
 548
 549 #define mutex_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 550 #define mutex_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 551 #define mutex_release(l, i)                     lock_release(l, i)
 552
 553 #define rwsem_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 554 #define rwsem_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 555 #define rwsem_acquire_read(l, s, t, i)          lock_acquire_shared(l, s, t, NULL, i)
 556 #define rwsem_release(l, i)                     lock_release(l, i)
 557
 558 #define lock_map_acquire(l)                     lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
 559 #define lock_map_acquire_read(l)                lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
 560 #define lock_map_acquire_tryread(l)             lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
 561 #define lock_map_release(l)                     lock_release(l, _THIS_IP_)
 562 #define lock_map_sync(l)                        lock_sync(l, 0, 0, 1, NULL, _THIS_IP_)
 563
 564 #ifdef CONFIG_PROVE_LOCKING
 565 # define might_lock(lock)                                               \
 566 do {                                                                    \
 567         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 568         lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);    \
 569         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 570 } while (0)
 571 # define might_lock_read(lock)                                          \
 572 do {                                                                    \
 573         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 574         lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);    \
 575         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 576 } while (0)
 577 # define might_lock_nested(lock, subclass)                              \
 578 do {                                                                    \
 579         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 580         lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,         \
 581                      _THIS_IP_);                                        \
 582         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 583 } while (0)
 584
 585 DECLARE_PER_CPU(int, hardirqs_enabled);
 586 DECLARE_PER_CPU(int, hardirq_context);
 587 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
 588
 589 #define __lockdep_enabled       (debug_locks && !this_cpu_read(lockdep_recursion))
 590
 591 #define lockdep_assert_irqs_enabled()                                   \
 592 do {                                                                    \
 593         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
 594 } while (0)
 595
 596 #define lockdep_assert_irqs_disabled()                                  \
 597 do {                                                                    \
 598         WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
 599 } while (0)
 600
 601 #define lockdep_assert_in_irq()                                         \
 602 do {                                                                    \
 603         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
 604 } while (0)
 605
 606 #define lockdep_assert_preemption_enabled()                             \
 607 do {                                                                    \
 608         WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)   &&              \
 609                      __lockdep_enabled                  &&              \
 610                      (preempt_count() != 0              ||              \
 611                       !this_cpu_read(hardirqs_enabled)));               \
 612 } while (0)
 613
 614 #define lockdep_assert_preemption_disabled()                            \
 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 /*
 623  * Acceptable for protecting per-CPU resources accessed from BH.
 624  * Much like in_softirq() - semantics are ambiguous, use carefully.
 625  */
 626 #define lockdep_assert_in_softirq()                                     \
 627 do {                                                                    \
 628         WARN_ON_ONCE(__lockdep_enabled                  &&              \
 629                      (!in_softirq() || in_irq() || in_nmi()));          \
 630 } while (0)
 631
 632 #else
 633 # define might_lock(lock) do { } while (0)
 634 # define might_lock_read(lock) do { } while (0)
 635 # define might_lock_nested(lock, subclass) do { } while (0)
 636
 637 # define lockdep_assert_irqs_enabled() do { } while (0)
 638 # define lockdep_assert_irqs_disabled() do { } while (0)
 639 # define lockdep_assert_in_irq() do { } while (0)
 640
 641 # define lockdep_assert_preemption_enabled() do { } while (0)
 642 # define lockdep_assert_preemption_disabled() do { } while (0)
 643 # define lockdep_assert_in_softirq() do { } while (0)
 644 #endif
 645
 646 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
 647
 648 # define lockdep_assert_RT_in_threaded_ctx() do {                       \
 649                 WARN_ONCE(debug_locks && !current->lockdep_recursion && \
 650                           lockdep_hardirq_context() &&                  \
 651                           !(current->hardirq_threaded || current->irq_config),  \
 652                           "Not in threaded context on PREEMPT_RT as expected\n");       \
 653 } while (0)
 654
 655 #else
 656
 657 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
 658
 659 #endif
 660
 661 #ifdef CONFIG_LOCKDEP
 662 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
 663 #else
 664 static inline void
 665 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 666 {
 667 }
 668 #endif
 669
 670 #endif /* __LINUX_LOCKDEP_H */