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, outer, 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_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
 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 #define lock_set_novalidate_class(l, n, i) \
 294         lock_set_class(l, n, &__lockdep_no_validate__, 0, i)
 295
 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
 344 static inline void lockdep_init_task(struct task_struct *task)
 345 {
 346 }
 347
 348 static inline void lockdep_off(void)
 349 {
 350 }
 351
 352 static inline void lockdep_on(void)
 353 {
 354 }
 355
 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
 394 static inline void lockdep_register_key(struct lock_class_key *key)
 395 {
 396 }
 397
 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
 446 static inline void lockdep_invariant_state(bool force) {}
 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
 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
 660 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 661 {
 662 }
 663 #endif
 664
 665 #endif /* __LINUX_LOCKDEP_H */