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, outer, 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_type(&(lock)->dep_map, #key, key, 0,   \
 219                               (lock)->dep_map.wait_type_inner,  \
 220                               (lock)->dep_map.wait_type_outer,  \
 221                               (lock)->dep_map.lock_type)
 222
 223 #define lockdep_set_class_and_name(lock, key, name)             \
 224         lockdep_init_map_type(&(lock)->dep_map, name, key, 0,   \
 225                               (lock)->dep_map.wait_type_inner,  \
 226                               (lock)->dep_map.wait_type_outer,  \
 227                               (lock)->dep_map.lock_type)
 228
 229 #define lockdep_set_class_and_subclass(lock, key, sub)          \
 230         lockdep_init_map_type(&(lock)->dep_map, #key, key, sub, \
 231                               (lock)->dep_map.wait_type_inner,  \
 232                               (lock)->dep_map.wait_type_outer,  \
 233                               (lock)->dep_map.lock_type)
 234
 235 #define lockdep_set_subclass(lock, sub)                                 \
 236         lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
 237                               (lock)->dep_map.wait_type_inner,          \
 238                               (lock)->dep_map.wait_type_outer,          \
 239                               (lock)->dep_map.lock_type)
 240
 241 #define lockdep_set_novalidate_class(lock) \
 242         lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
 243
 244 /*
 245  * Compare locking classes
 246  */
 247 #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)
 248
 249 static inline int lockdep_match_key(struct lockdep_map *lock,
 250                                     struct lock_class_key *key)
 251 {
 252         return lock->key == key;
 253 }
 254
 255 /*
 256  * Acquire a lock.
 257  *
 258  * Values for "read":
 259  *
 260  *   0: exclusive (write) acquire
 261  *   1: read-acquire (no recursion allowed)
 262  *   2: read-acquire with same-instance recursion allowed
 263  *
 264  * Values for check:
 265  *
 266  *   0: simple checks (freeing, held-at-exit-time, etc.)
 267  *   1: full validation
 268  */
 269 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 270                          int trylock, int read, int check,
 271                          struct lockdep_map *nest_lock, unsigned long ip);
 272
 273 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
 274
 275 /* lock_is_held_type() returns */
 276 #define LOCK_STATE_UNKNOWN      -1
 277 #define LOCK_STATE_NOT_HELD     0
 278 #define LOCK_STATE_HELD         1
 279
 280 /*
 281  * Same "read" as for lock_acquire(), except -1 means any.
 282  */
 283 extern int lock_is_held_type(const struct lockdep_map *lock, int read);
 284
 285 static inline int lock_is_held(const struct lockdep_map *lock)
 286 {
 287         return lock_is_held_type(lock, -1);
 288 }
 289
 290 #define lockdep_is_held(lock)           lock_is_held(&(lock)->dep_map)
 291 #define lockdep_is_held_type(lock, r)   lock_is_held_type(&(lock)->dep_map, (r))
 292
 293 extern void lock_set_class(struct lockdep_map *lock, const char *name,
 294                            struct lock_class_key *key, unsigned int subclass,
 295                            unsigned long ip);
 296
 297 static inline void lock_set_subclass(struct lockdep_map *lock,
 298                 unsigned int subclass, unsigned long ip)
 299 {
 300         lock_set_class(lock, lock->name, lock->key, subclass, ip);
 301 }
 302
 303 extern void lock_downgrade(struct lockdep_map *lock, unsigned long ip);
 304
 305 #define NIL_COOKIE (struct pin_cookie){ .val = 0U, }
 306
 307 extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
 308 extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
 309 extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 310
 311 #define lockdep_depth(tsk)      (debug_locks ? (tsk)->lockdep_depth : 0)
 312
 313 #define lockdep_assert(cond)            \
 314         do { WARN_ON(debug_locks && !(cond)); } while (0)
 315
 316 #define lockdep_assert_once(cond)       \
 317         do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
 318
 319 #define lockdep_assert_held(l)          \
 320         lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
 321
 322 #define lockdep_assert_not_held(l)      \
 323         lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
 324
 325 #define lockdep_assert_held_write(l)    \
 326         lockdep_assert(lockdep_is_held_type(l, 0))
 327
 328 #define lockdep_assert_held_read(l)     \
 329         lockdep_assert(lockdep_is_held_type(l, 1))
 330
 331 #define lockdep_assert_held_once(l)             \
 332         lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
 333
 334 #define lockdep_assert_none_held_once()         \
 335         lockdep_assert_once(!current->lockdep_depth)
 336
 337 #define lockdep_recursing(tsk)  ((tsk)->lockdep_recursion)
 338
 339 #define lockdep_pin_lock(l)     lock_pin_lock(&(l)->dep_map)
 340 #define lockdep_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c))
 341 #define lockdep_unpin_lock(l,c) lock_unpin_lock(&(l)->dep_map, (c))
 342
 343 #else /* !CONFIG_LOCKDEP */
 344
 345 static inline void lockdep_init_task(struct task_struct *task)
 346 {
 347 }
 348
 349 static inline void lockdep_off(void)
 350 {
 351 }
 352
 353 static inline void lockdep_on(void)
 354 {
 355 }
 356
 357 static inline void lockdep_set_selftest_task(struct task_struct *task)
 358 {
 359 }
 360
 361 # define lock_acquire(l, s, t, r, c, n, i)      do { } while (0)
 362 # define lock_release(l, i)                     do { } while (0)
 363 # define lock_downgrade(l, i)                   do { } while (0)
 364 # define lock_set_class(l, n, k, s, 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_LOCKDEP
 489
 490 /*
 491  * On lockdep we dont want the hand-coded irq-enable of
 492  * _raw_*_lock_flags() code, because lockdep assumes
 493  * that interrupts are not re-enabled during lock-acquire:
 494  */
 495 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
 496         LOCK_CONTENDED((_lock), (try), (lock))
 497
 498 #else /* CONFIG_LOCKDEP */
 499
 500 #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
 501         lockfl((_lock), (flags))
 502
 503 #endif /* CONFIG_LOCKDEP */
 504
 505 #ifdef CONFIG_PROVE_LOCKING
 506 extern void print_irqtrace_events(struct task_struct *curr);
 507 #else
 508 static inline void print_irqtrace_events(struct task_struct *curr)
 509 {
 510 }
 511 #endif
 512
 513 /* Variable used to make lockdep treat read_lock() as recursive in selftests */
 514 #ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
 515 extern unsigned int force_read_lock_recursive;
 516 #else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 517 #define force_read_lock_recursive 0
 518 #endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
 519
 520 #ifdef CONFIG_LOCKDEP
 521 extern bool read_lock_is_recursive(void);
 522 #else /* CONFIG_LOCKDEP */
 523 /* If !LOCKDEP, the value is meaningless */
 524 #define read_lock_is_recursive() 0
 525 #endif
 526
 527 /*
 528  * For trivial one-depth nesting of a lock-class, the following
 529  * global define can be used. (Subsystems with multiple levels
 530  * of nesting should define their own lock-nesting subclasses.)
 531  */
 532 #define SINGLE_DEPTH_NESTING                    1
 533
 534 /*
 535  * Map the dependency ops to NOP or to real lockdep ops, depending
 536  * on the per lock-class debug mode:
 537  */
 538
 539 #define lock_acquire_exclusive(l, s, t, n, i)           lock_acquire(l, s, t, 0, 1, n, i)
 540 #define lock_acquire_shared(l, s, t, n, i)              lock_acquire(l, s, t, 1, 1, n, i)
 541 #define lock_acquire_shared_recursive(l, s, t, n, i)    lock_acquire(l, s, t, 2, 1, n, i)
 542
 543 #define spin_acquire(l, s, t, i)                lock_acquire_exclusive(l, s, t, NULL, i)
 544 #define spin_acquire_nest(l, s, t, n, i)        lock_acquire_exclusive(l, s, t, n, i)
 545 #define spin_release(l, i)                      lock_release(l, i)
 546
 547 #define rwlock_acquire(l, s, t, i)              lock_acquire_exclusive(l, s, t, NULL, i)
 548 #define rwlock_acquire_read(l, s, t, i)                                 \
 549 do {                                                                    \
 550         if (read_lock_is_recursive())                                   \
 551                 lock_acquire_shared_recursive(l, s, t, NULL, i);        \
 552         else                                                            \
 553                 lock_acquire_shared(l, s, t, NULL, i);                  \
 554 } while (0)
 555
 556 #define rwlock_release(l, i)                    lock_release(l, i)
 557
 558 #define seqcount_acquire(l, s, t, i)            lock_acquire_exclusive(l, s, t, NULL, i)
 559 #define seqcount_acquire_read(l, s, t, i)       lock_acquire_shared_recursive(l, s, t, NULL, i)
 560 #define seqcount_release(l, i)                  lock_release(l, i)
 561
 562 #define mutex_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 563 #define mutex_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 564 #define mutex_release(l, i)                     lock_release(l, i)
 565
 566 #define rwsem_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
 567 #define rwsem_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
 568 #define rwsem_acquire_read(l, s, t, i)          lock_acquire_shared(l, s, t, NULL, i)
 569 #define rwsem_release(l, i)                     lock_release(l, i)
 570
 571 #define lock_map_acquire(l)                     lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
 572 #define lock_map_acquire_read(l)                lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
 573 #define lock_map_acquire_tryread(l)             lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
 574 #define lock_map_release(l)                     lock_release(l, _THIS_IP_)
 575
 576 #ifdef CONFIG_PROVE_LOCKING
 577 # define might_lock(lock)                                               \
 578 do {                                                                    \
 579         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 580         lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);    \
 581         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 582 } while (0)
 583 # define might_lock_read(lock)                                          \
 584 do {                                                                    \
 585         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 586         lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);    \
 587         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 588 } while (0)
 589 # define might_lock_nested(lock, subclass)                              \
 590 do {                                                                    \
 591         typecheck(struct lockdep_map *, &(lock)->dep_map);              \
 592         lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,         \
 593                      _THIS_IP_);                                        \
 594         lock_release(&(lock)->dep_map, _THIS_IP_);                      \
 595 } while (0)
 596
 597 DECLARE_PER_CPU(int, hardirqs_enabled);
 598 DECLARE_PER_CPU(int, hardirq_context);
 599 DECLARE_PER_CPU(unsigned int, lockdep_recursion);
 600
 601 #define __lockdep_enabled       (debug_locks && !this_cpu_read(lockdep_recursion))
 602
 603 #define lockdep_assert_irqs_enabled()                                   \
 604 do {                                                                    \
 605         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
 606 } while (0)
 607
 608 #define lockdep_assert_irqs_disabled()                                  \
 609 do {                                                                    \
 610         WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
 611 } while (0)
 612
 613 #define lockdep_assert_in_irq()                                         \
 614 do {                                                                    \
 615         WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
 616 } while (0)
 617
 618 #define lockdep_assert_preemption_enabled()                             \
 619 do {                                                                    \
 620         WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)   &&              \
 621                      __lockdep_enabled                  &&              \
 622                      (preempt_count() != 0              ||              \
 623                       !this_cpu_read(hardirqs_enabled)));               \
 624 } while (0)
 625
 626 #define lockdep_assert_preemption_disabled()                            \
 627 do {                                                                    \
 628         WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT)   &&              \
 629                      __lockdep_enabled                  &&              \
 630                      (preempt_count() == 0              &&              \
 631                       this_cpu_read(hardirqs_enabled)));                \
 632 } while (0)
 633
 634 /*
 635  * Acceptable for protecting per-CPU resources accessed from BH.
 636  * Much like in_softirq() - semantics are ambiguous, use carefully.
 637  */
 638 #define lockdep_assert_in_softirq()                                     \
 639 do {                                                                    \
 640         WARN_ON_ONCE(__lockdep_enabled                  &&              \
 641                      (!in_softirq() || in_irq() || in_nmi()));          \
 642 } while (0)
 643
 644 #else
 645 # define might_lock(lock) do { } while (0)
 646 # define might_lock_read(lock) do { } while (0)
 647 # define might_lock_nested(lock, subclass) do { } while (0)
 648
 649 # define lockdep_assert_irqs_enabled() do { } while (0)
 650 # define lockdep_assert_irqs_disabled() do { } while (0)
 651 # define lockdep_assert_in_irq() do { } while (0)
 652
 653 # define lockdep_assert_preemption_enabled() do { } while (0)
 654 # define lockdep_assert_preemption_disabled() do { } while (0)
 655 # define lockdep_assert_in_softirq() do { } while (0)
 656 #endif
 657
 658 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
 659
 660 # define lockdep_assert_RT_in_threaded_ctx() do {                       \
 661                 WARN_ONCE(debug_locks && !current->lockdep_recursion && \
 662                           lockdep_hardirq_context() &&                  \
 663                           !(current->hardirq_threaded || current->irq_config),  \
 664                           "Not in threaded context on PREEMPT_RT as expected\n");       \
 665 } while (0)
 666
 667 #else
 668
 669 # define lockdep_assert_RT_in_threaded_ctx() do { } while (0)
 670
 671 #endif
 672
 673 #ifdef CONFIG_LOCKDEP
 674 void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
 675 #else
 676 static inline void
 677 lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 678 {
 679 }
 680 #endif
 681
 682 #endif /* __LINUX_LOCKDEP_H */