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fbb9ce95 IM |
1 | /* |
2 | * Runtime locking correctness validator | |
3 | * | |
4b32d0a4 PZ |
4 | * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
5 | * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> | |
fbb9ce95 IM |
6 | * |
7 | * see Documentation/lockdep-design.txt for more details. | |
8 | */ | |
9 | #ifndef __LINUX_LOCKDEP_H | |
10 | #define __LINUX_LOCKDEP_H | |
11 | ||
a1e96b03 | 12 | struct task_struct; |
f20786ff | 13 | struct lockdep_map; |
a1e96b03 | 14 | |
db0b0ead MT |
15 | #ifdef CONFIG_LOCKDEP |
16 | ||
fbb9ce95 IM |
17 | #include <linux/linkage.h> |
18 | #include <linux/list.h> | |
19 | #include <linux/debug_locks.h> | |
20 | #include <linux/stacktrace.h> | |
21 | ||
fbb9ce95 IM |
22 | /* |
23 | * Lock-class usage-state bits: | |
24 | */ | |
25 | enum lock_usage_bit | |
26 | { | |
27 | LOCK_USED = 0, | |
28 | LOCK_USED_IN_HARDIRQ, | |
29 | LOCK_USED_IN_SOFTIRQ, | |
30 | LOCK_ENABLED_SOFTIRQS, | |
31 | LOCK_ENABLED_HARDIRQS, | |
32 | LOCK_USED_IN_HARDIRQ_READ, | |
33 | LOCK_USED_IN_SOFTIRQ_READ, | |
34 | LOCK_ENABLED_SOFTIRQS_READ, | |
35 | LOCK_ENABLED_HARDIRQS_READ, | |
36 | LOCK_USAGE_STATES | |
37 | }; | |
38 | ||
39 | /* | |
40 | * Usage-state bitmasks: | |
41 | */ | |
42 | #define LOCKF_USED (1 << LOCK_USED) | |
43 | #define LOCKF_USED_IN_HARDIRQ (1 << LOCK_USED_IN_HARDIRQ) | |
44 | #define LOCKF_USED_IN_SOFTIRQ (1 << LOCK_USED_IN_SOFTIRQ) | |
45 | #define LOCKF_ENABLED_HARDIRQS (1 << LOCK_ENABLED_HARDIRQS) | |
46 | #define LOCKF_ENABLED_SOFTIRQS (1 << LOCK_ENABLED_SOFTIRQS) | |
47 | ||
48 | #define LOCKF_ENABLED_IRQS (LOCKF_ENABLED_HARDIRQS | LOCKF_ENABLED_SOFTIRQS) | |
49 | #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ) | |
50 | ||
51 | #define LOCKF_USED_IN_HARDIRQ_READ (1 << LOCK_USED_IN_HARDIRQ_READ) | |
52 | #define LOCKF_USED_IN_SOFTIRQ_READ (1 << LOCK_USED_IN_SOFTIRQ_READ) | |
53 | #define LOCKF_ENABLED_HARDIRQS_READ (1 << LOCK_ENABLED_HARDIRQS_READ) | |
54 | #define LOCKF_ENABLED_SOFTIRQS_READ (1 << LOCK_ENABLED_SOFTIRQS_READ) | |
55 | ||
56 | #define LOCKF_ENABLED_IRQS_READ \ | |
57 | (LOCKF_ENABLED_HARDIRQS_READ | LOCKF_ENABLED_SOFTIRQS_READ) | |
58 | #define LOCKF_USED_IN_IRQ_READ \ | |
59 | (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ) | |
60 | ||
61 | #define MAX_LOCKDEP_SUBCLASSES 8UL | |
62 | ||
63 | /* | |
64 | * Lock-classes are keyed via unique addresses, by embedding the | |
65 | * lockclass-key into the kernel (or module) .data section. (For | |
66 | * static locks we use the lock address itself as the key.) | |
67 | */ | |
68 | struct lockdep_subclass_key { | |
69 | char __one_byte; | |
70 | } __attribute__ ((__packed__)); | |
71 | ||
72 | struct lock_class_key { | |
73 | struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES]; | |
74 | }; | |
75 | ||
76 | /* | |
77 | * The lock-class itself: | |
78 | */ | |
79 | struct lock_class { | |
80 | /* | |
81 | * class-hash: | |
82 | */ | |
83 | struct list_head hash_entry; | |
84 | ||
85 | /* | |
86 | * global list of all lock-classes: | |
87 | */ | |
88 | struct list_head lock_entry; | |
89 | ||
90 | struct lockdep_subclass_key *key; | |
91 | unsigned int subclass; | |
419ca3f1 | 92 | unsigned int dep_gen_id; |
fbb9ce95 IM |
93 | |
94 | /* | |
95 | * IRQ/softirq usage tracking bits: | |
96 | */ | |
97 | unsigned long usage_mask; | |
98 | struct stack_trace usage_traces[LOCK_USAGE_STATES]; | |
99 | ||
100 | /* | |
101 | * These fields represent a directed graph of lock dependencies, | |
102 | * to every node we attach a list of "forward" and a list of | |
103 | * "backward" graph nodes. | |
104 | */ | |
105 | struct list_head locks_after, locks_before; | |
106 | ||
107 | /* | |
108 | * Generation counter, when doing certain classes of graph walking, | |
109 | * to ensure that we check one node only once: | |
110 | */ | |
111 | unsigned int version; | |
112 | ||
113 | /* | |
114 | * Statistics counter: | |
115 | */ | |
116 | unsigned long ops; | |
117 | ||
118 | const char *name; | |
119 | int name_version; | |
f20786ff PZ |
120 | |
121 | #ifdef CONFIG_LOCK_STAT | |
122 | unsigned long contention_point[4]; | |
123 | #endif | |
124 | }; | |
125 | ||
126 | #ifdef CONFIG_LOCK_STAT | |
127 | struct lock_time { | |
128 | s64 min; | |
129 | s64 max; | |
130 | s64 total; | |
131 | unsigned long nr; | |
fbb9ce95 IM |
132 | }; |
133 | ||
96645678 PZ |
134 | enum bounce_type { |
135 | bounce_acquired_write, | |
136 | bounce_acquired_read, | |
137 | bounce_contended_write, | |
138 | bounce_contended_read, | |
139 | nr_bounce_types, | |
140 | ||
141 | bounce_acquired = bounce_acquired_write, | |
142 | bounce_contended = bounce_contended_write, | |
143 | }; | |
144 | ||
f20786ff PZ |
145 | struct lock_class_stats { |
146 | unsigned long contention_point[4]; | |
147 | struct lock_time read_waittime; | |
148 | struct lock_time write_waittime; | |
149 | struct lock_time read_holdtime; | |
150 | struct lock_time write_holdtime; | |
96645678 | 151 | unsigned long bounces[nr_bounce_types]; |
f20786ff PZ |
152 | }; |
153 | ||
154 | struct lock_class_stats lock_stats(struct lock_class *class); | |
155 | void clear_lock_stats(struct lock_class *class); | |
156 | #endif | |
157 | ||
fbb9ce95 IM |
158 | /* |
159 | * Map the lock object (the lock instance) to the lock-class object. | |
160 | * This is embedded into specific lock instances: | |
161 | */ | |
162 | struct lockdep_map { | |
163 | struct lock_class_key *key; | |
d6d897ce | 164 | struct lock_class *class_cache; |
fbb9ce95 | 165 | const char *name; |
96645678 PZ |
166 | #ifdef CONFIG_LOCK_STAT |
167 | int cpu; | |
168 | #endif | |
fbb9ce95 IM |
169 | }; |
170 | ||
171 | /* | |
172 | * Every lock has a list of other locks that were taken after it. | |
173 | * We only grow the list, never remove from it: | |
174 | */ | |
175 | struct lock_list { | |
176 | struct list_head entry; | |
177 | struct lock_class *class; | |
178 | struct stack_trace trace; | |
068135e6 | 179 | int distance; |
fbb9ce95 IM |
180 | }; |
181 | ||
182 | /* | |
183 | * We record lock dependency chains, so that we can cache them: | |
184 | */ | |
185 | struct lock_chain { | |
443cd507 HY |
186 | u8 irq_context; |
187 | u8 depth; | |
188 | u16 base; | |
fbb9ce95 IM |
189 | struct list_head entry; |
190 | u64 chain_key; | |
191 | }; | |
192 | ||
f82b217e DJ |
193 | #define MAX_LOCKDEP_KEYS_BITS 11 |
194 | #define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS) | |
195 | ||
fbb9ce95 IM |
196 | struct held_lock { |
197 | /* | |
198 | * One-way hash of the dependency chain up to this point. We | |
199 | * hash the hashes step by step as the dependency chain grows. | |
200 | * | |
201 | * We use it for dependency-caching and we skip detection | |
202 | * passes and dependency-updates if there is a cache-hit, so | |
203 | * it is absolutely critical for 100% coverage of the validator | |
204 | * to have a unique key value for every unique dependency path | |
205 | * that can occur in the system, to make a unique hash value | |
206 | * as likely as possible - hence the 64-bit width. | |
207 | * | |
208 | * The task struct holds the current hash value (initialized | |
209 | * with zero), here we store the previous hash value: | |
210 | */ | |
211 | u64 prev_chain_key; | |
fbb9ce95 IM |
212 | unsigned long acquire_ip; |
213 | struct lockdep_map *instance; | |
f20786ff PZ |
214 | #ifdef CONFIG_LOCK_STAT |
215 | u64 waittime_stamp; | |
216 | u64 holdtime_stamp; | |
217 | #endif | |
f82b217e | 218 | unsigned int class_idx:MAX_LOCKDEP_KEYS_BITS; |
fbb9ce95 IM |
219 | /* |
220 | * The lock-stack is unified in that the lock chains of interrupt | |
221 | * contexts nest ontop of process context chains, but we 'separate' | |
222 | * the hashes by starting with 0 if we cross into an interrupt | |
223 | * context, and we also keep do not add cross-context lock | |
224 | * dependencies - the lock usage graph walking covers that area | |
225 | * anyway, and we'd just unnecessarily increase the number of | |
226 | * dependencies otherwise. [Note: hardirq and softirq contexts | |
227 | * are separated from each other too.] | |
228 | * | |
229 | * The following field is used to detect when we cross into an | |
230 | * interrupt context: | |
231 | */ | |
f82b217e DJ |
232 | unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */ |
233 | unsigned int trylock:1; | |
234 | unsigned int read:2; /* see lock_acquire() comment */ | |
235 | unsigned int check:2; /* see lock_acquire() comment */ | |
236 | unsigned int hardirqs_off:1; | |
fbb9ce95 IM |
237 | }; |
238 | ||
239 | /* | |
240 | * Initialization, self-test and debugging-output methods: | |
241 | */ | |
242 | extern void lockdep_init(void); | |
243 | extern void lockdep_info(void); | |
244 | extern void lockdep_reset(void); | |
245 | extern void lockdep_reset_lock(struct lockdep_map *lock); | |
246 | extern void lockdep_free_key_range(void *start, unsigned long size); | |
b351d164 | 247 | extern void lockdep_sys_exit(void); |
fbb9ce95 IM |
248 | |
249 | extern void lockdep_off(void); | |
250 | extern void lockdep_on(void); | |
fbb9ce95 IM |
251 | |
252 | /* | |
253 | * These methods are used by specific locking variants (spinlocks, | |
254 | * rwlocks, mutexes and rwsems) to pass init/acquire/release events | |
255 | * to lockdep: | |
256 | */ | |
257 | ||
258 | extern void lockdep_init_map(struct lockdep_map *lock, const char *name, | |
4dfbb9d8 | 259 | struct lock_class_key *key, int subclass); |
fbb9ce95 | 260 | |
851a67b8 PZ |
261 | /* |
262 | * To initialize a lockdep_map statically use this macro. | |
263 | * Note that _name must not be NULL. | |
264 | */ | |
265 | #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \ | |
266 | { .name = (_name), .key = (void *)(_key), } | |
267 | ||
fbb9ce95 IM |
268 | /* |
269 | * Reinitialize a lock key - for cases where there is special locking or | |
270 | * special initialization of locks so that the validator gets the scope | |
271 | * of dependencies wrong: they are either too broad (they need a class-split) | |
272 | * or they are too narrow (they suffer from a false class-split): | |
273 | */ | |
274 | #define lockdep_set_class(lock, key) \ | |
4dfbb9d8 | 275 | lockdep_init_map(&(lock)->dep_map, #key, key, 0) |
fbb9ce95 | 276 | #define lockdep_set_class_and_name(lock, key, name) \ |
4dfbb9d8 PZ |
277 | lockdep_init_map(&(lock)->dep_map, name, key, 0) |
278 | #define lockdep_set_class_and_subclass(lock, key, sub) \ | |
279 | lockdep_init_map(&(lock)->dep_map, #key, key, sub) | |
280 | #define lockdep_set_subclass(lock, sub) \ | |
281 | lockdep_init_map(&(lock)->dep_map, #lock, \ | |
282 | (lock)->dep_map.key, sub) | |
fbb9ce95 IM |
283 | |
284 | /* | |
285 | * Acquire a lock. | |
286 | * | |
287 | * Values for "read": | |
288 | * | |
289 | * 0: exclusive (write) acquire | |
290 | * 1: read-acquire (no recursion allowed) | |
291 | * 2: read-acquire with same-instance recursion allowed | |
292 | * | |
293 | * Values for check: | |
294 | * | |
295 | * 0: disabled | |
296 | * 1: simple checks (freeing, held-at-exit-time, etc.) | |
297 | * 2: full validation | |
298 | */ | |
299 | extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass, | |
300 | int trylock, int read, int check, unsigned long ip); | |
301 | ||
302 | extern void lock_release(struct lockdep_map *lock, int nested, | |
303 | unsigned long ip); | |
304 | ||
64aa348e PZ |
305 | extern void lock_set_subclass(struct lockdep_map *lock, unsigned int subclass, |
306 | unsigned long ip); | |
307 | ||
fbb9ce95 IM |
308 | # define INIT_LOCKDEP .lockdep_recursion = 0, |
309 | ||
e3a55fd1 | 310 | #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) |
d5abe669 | 311 | |
fbb9ce95 IM |
312 | #else /* !LOCKDEP */ |
313 | ||
314 | static inline void lockdep_off(void) | |
315 | { | |
316 | } | |
317 | ||
318 | static inline void lockdep_on(void) | |
319 | { | |
320 | } | |
321 | ||
fbb9ce95 IM |
322 | # define lock_acquire(l, s, t, r, c, i) do { } while (0) |
323 | # define lock_release(l, n, i) do { } while (0) | |
64aa348e | 324 | # define lock_set_subclass(l, s, i) do { } while (0) |
fbb9ce95 IM |
325 | # define lockdep_init() do { } while (0) |
326 | # define lockdep_info() do { } while (0) | |
4dfbb9d8 | 327 | # define lockdep_init_map(lock, name, key, sub) do { (void)(key); } while (0) |
fbb9ce95 IM |
328 | # define lockdep_set_class(lock, key) do { (void)(key); } while (0) |
329 | # define lockdep_set_class_and_name(lock, key, name) \ | |
330 | do { (void)(key); } while (0) | |
4dfbb9d8 PZ |
331 | #define lockdep_set_class_and_subclass(lock, key, sub) \ |
332 | do { (void)(key); } while (0) | |
07646e21 AM |
333 | #define lockdep_set_subclass(lock, sub) do { } while (0) |
334 | ||
fbb9ce95 IM |
335 | # define INIT_LOCKDEP |
336 | # define lockdep_reset() do { debug_locks = 1; } while (0) | |
337 | # define lockdep_free_key_range(start, size) do { } while (0) | |
b351d164 | 338 | # define lockdep_sys_exit() do { } while (0) |
fbb9ce95 IM |
339 | /* |
340 | * The class key takes no space if lockdep is disabled: | |
341 | */ | |
342 | struct lock_class_key { }; | |
d5abe669 PZ |
343 | |
344 | #define lockdep_depth(tsk) (0) | |
345 | ||
fbb9ce95 IM |
346 | #endif /* !LOCKDEP */ |
347 | ||
f20786ff PZ |
348 | #ifdef CONFIG_LOCK_STAT |
349 | ||
350 | extern void lock_contended(struct lockdep_map *lock, unsigned long ip); | |
351 | extern void lock_acquired(struct lockdep_map *lock); | |
352 | ||
353 | #define LOCK_CONTENDED(_lock, try, lock) \ | |
354 | do { \ | |
355 | if (!try(_lock)) { \ | |
356 | lock_contended(&(_lock)->dep_map, _RET_IP_); \ | |
357 | lock(_lock); \ | |
f20786ff | 358 | } \ |
96645678 | 359 | lock_acquired(&(_lock)->dep_map); \ |
f20786ff PZ |
360 | } while (0) |
361 | ||
362 | #else /* CONFIG_LOCK_STAT */ | |
363 | ||
364 | #define lock_contended(lockdep_map, ip) do {} while (0) | |
365 | #define lock_acquired(lockdep_map) do {} while (0) | |
366 | ||
367 | #define LOCK_CONTENDED(_lock, try, lock) \ | |
368 | lock(_lock) | |
369 | ||
370 | #endif /* CONFIG_LOCK_STAT */ | |
371 | ||
243c7621 IM |
372 | #if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS) |
373 | extern void early_init_irq_lock_class(void); | |
374 | #else | |
3117df04 IM |
375 | static inline void early_init_irq_lock_class(void) |
376 | { | |
377 | } | |
243c7621 IM |
378 | #endif |
379 | ||
fbb9ce95 IM |
380 | #ifdef CONFIG_TRACE_IRQFLAGS |
381 | extern void early_boot_irqs_off(void); | |
382 | extern void early_boot_irqs_on(void); | |
3117df04 | 383 | extern void print_irqtrace_events(struct task_struct *curr); |
fbb9ce95 | 384 | #else |
3117df04 IM |
385 | static inline void early_boot_irqs_off(void) |
386 | { | |
387 | } | |
388 | static inline void early_boot_irqs_on(void) | |
389 | { | |
390 | } | |
391 | static inline void print_irqtrace_events(struct task_struct *curr) | |
392 | { | |
393 | } | |
fbb9ce95 IM |
394 | #endif |
395 | ||
396 | /* | |
397 | * For trivial one-depth nesting of a lock-class, the following | |
398 | * global define can be used. (Subsystems with multiple levels | |
399 | * of nesting should define their own lock-nesting subclasses.) | |
400 | */ | |
401 | #define SINGLE_DEPTH_NESTING 1 | |
402 | ||
403 | /* | |
404 | * Map the dependency ops to NOP or to real lockdep ops, depending | |
405 | * on the per lock-class debug mode: | |
406 | */ | |
407 | ||
408 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
409 | # ifdef CONFIG_PROVE_LOCKING | |
410 | # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
411 | # else | |
412 | # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
413 | # endif | |
414 | # define spin_release(l, n, i) lock_release(l, n, i) | |
415 | #else | |
416 | # define spin_acquire(l, s, t, i) do { } while (0) | |
417 | # define spin_release(l, n, i) do { } while (0) | |
418 | #endif | |
419 | ||
420 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
421 | # ifdef CONFIG_PROVE_LOCKING | |
422 | # define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
423 | # define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 2, i) | |
424 | # else | |
425 | # define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
426 | # define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 1, i) | |
427 | # endif | |
428 | # define rwlock_release(l, n, i) lock_release(l, n, i) | |
429 | #else | |
430 | # define rwlock_acquire(l, s, t, i) do { } while (0) | |
431 | # define rwlock_acquire_read(l, s, t, i) do { } while (0) | |
432 | # define rwlock_release(l, n, i) do { } while (0) | |
433 | #endif | |
434 | ||
435 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
436 | # ifdef CONFIG_PROVE_LOCKING | |
437 | # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
438 | # else | |
439 | # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
440 | # endif | |
441 | # define mutex_release(l, n, i) lock_release(l, n, i) | |
442 | #else | |
443 | # define mutex_acquire(l, s, t, i) do { } while (0) | |
444 | # define mutex_release(l, n, i) do { } while (0) | |
445 | #endif | |
446 | ||
447 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
448 | # ifdef CONFIG_PROVE_LOCKING | |
449 | # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
450 | # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, i) | |
451 | # else | |
452 | # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
453 | # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, i) | |
454 | # endif | |
455 | # define rwsem_release(l, n, i) lock_release(l, n, i) | |
456 | #else | |
457 | # define rwsem_acquire(l, s, t, i) do { } while (0) | |
458 | # define rwsem_acquire_read(l, s, t, i) do { } while (0) | |
459 | # define rwsem_release(l, n, i) do { } while (0) | |
460 | #endif | |
461 | ||
462 | #endif /* __LINUX_LOCKDEP_H */ |