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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; | |
92 | ||
93 | /* | |
94 | * IRQ/softirq usage tracking bits: | |
95 | */ | |
96 | unsigned long usage_mask; | |
97 | struct stack_trace usage_traces[LOCK_USAGE_STATES]; | |
98 | ||
99 | /* | |
100 | * These fields represent a directed graph of lock dependencies, | |
101 | * to every node we attach a list of "forward" and a list of | |
102 | * "backward" graph nodes. | |
103 | */ | |
104 | struct list_head locks_after, locks_before; | |
105 | ||
106 | /* | |
107 | * Generation counter, when doing certain classes of graph walking, | |
108 | * to ensure that we check one node only once: | |
109 | */ | |
110 | unsigned int version; | |
111 | ||
112 | /* | |
113 | * Statistics counter: | |
114 | */ | |
115 | unsigned long ops; | |
116 | ||
117 | const char *name; | |
118 | int name_version; | |
f20786ff PZ |
119 | |
120 | #ifdef CONFIG_LOCK_STAT | |
121 | unsigned long contention_point[4]; | |
122 | #endif | |
123 | }; | |
124 | ||
125 | #ifdef CONFIG_LOCK_STAT | |
126 | struct lock_time { | |
127 | s64 min; | |
128 | s64 max; | |
129 | s64 total; | |
130 | unsigned long nr; | |
fbb9ce95 IM |
131 | }; |
132 | ||
f20786ff PZ |
133 | struct lock_class_stats { |
134 | unsigned long contention_point[4]; | |
135 | struct lock_time read_waittime; | |
136 | struct lock_time write_waittime; | |
137 | struct lock_time read_holdtime; | |
138 | struct lock_time write_holdtime; | |
139 | }; | |
140 | ||
141 | struct lock_class_stats lock_stats(struct lock_class *class); | |
142 | void clear_lock_stats(struct lock_class *class); | |
143 | #endif | |
144 | ||
fbb9ce95 IM |
145 | /* |
146 | * Map the lock object (the lock instance) to the lock-class object. | |
147 | * This is embedded into specific lock instances: | |
148 | */ | |
149 | struct lockdep_map { | |
150 | struct lock_class_key *key; | |
d6d897ce | 151 | struct lock_class *class_cache; |
fbb9ce95 IM |
152 | const char *name; |
153 | }; | |
154 | ||
155 | /* | |
156 | * Every lock has a list of other locks that were taken after it. | |
157 | * We only grow the list, never remove from it: | |
158 | */ | |
159 | struct lock_list { | |
160 | struct list_head entry; | |
161 | struct lock_class *class; | |
162 | struct stack_trace trace; | |
068135e6 | 163 | int distance; |
fbb9ce95 IM |
164 | }; |
165 | ||
166 | /* | |
167 | * We record lock dependency chains, so that we can cache them: | |
168 | */ | |
169 | struct lock_chain { | |
170 | struct list_head entry; | |
171 | u64 chain_key; | |
172 | }; | |
173 | ||
174 | struct held_lock { | |
175 | /* | |
176 | * One-way hash of the dependency chain up to this point. We | |
177 | * hash the hashes step by step as the dependency chain grows. | |
178 | * | |
179 | * We use it for dependency-caching and we skip detection | |
180 | * passes and dependency-updates if there is a cache-hit, so | |
181 | * it is absolutely critical for 100% coverage of the validator | |
182 | * to have a unique key value for every unique dependency path | |
183 | * that can occur in the system, to make a unique hash value | |
184 | * as likely as possible - hence the 64-bit width. | |
185 | * | |
186 | * The task struct holds the current hash value (initialized | |
187 | * with zero), here we store the previous hash value: | |
188 | */ | |
189 | u64 prev_chain_key; | |
190 | struct lock_class *class; | |
191 | unsigned long acquire_ip; | |
192 | struct lockdep_map *instance; | |
193 | ||
f20786ff PZ |
194 | #ifdef CONFIG_LOCK_STAT |
195 | u64 waittime_stamp; | |
196 | u64 holdtime_stamp; | |
197 | #endif | |
fbb9ce95 IM |
198 | /* |
199 | * The lock-stack is unified in that the lock chains of interrupt | |
200 | * contexts nest ontop of process context chains, but we 'separate' | |
201 | * the hashes by starting with 0 if we cross into an interrupt | |
202 | * context, and we also keep do not add cross-context lock | |
203 | * dependencies - the lock usage graph walking covers that area | |
204 | * anyway, and we'd just unnecessarily increase the number of | |
205 | * dependencies otherwise. [Note: hardirq and softirq contexts | |
206 | * are separated from each other too.] | |
207 | * | |
208 | * The following field is used to detect when we cross into an | |
209 | * interrupt context: | |
210 | */ | |
211 | int irq_context; | |
212 | int trylock; | |
213 | int read; | |
214 | int check; | |
215 | int hardirqs_off; | |
216 | }; | |
217 | ||
218 | /* | |
219 | * Initialization, self-test and debugging-output methods: | |
220 | */ | |
221 | extern void lockdep_init(void); | |
222 | extern void lockdep_info(void); | |
223 | extern void lockdep_reset(void); | |
224 | extern void lockdep_reset_lock(struct lockdep_map *lock); | |
225 | extern void lockdep_free_key_range(void *start, unsigned long size); | |
226 | ||
227 | extern void lockdep_off(void); | |
228 | extern void lockdep_on(void); | |
fbb9ce95 IM |
229 | |
230 | /* | |
231 | * These methods are used by specific locking variants (spinlocks, | |
232 | * rwlocks, mutexes and rwsems) to pass init/acquire/release events | |
233 | * to lockdep: | |
234 | */ | |
235 | ||
236 | extern void lockdep_init_map(struct lockdep_map *lock, const char *name, | |
4dfbb9d8 | 237 | struct lock_class_key *key, int subclass); |
fbb9ce95 IM |
238 | |
239 | /* | |
240 | * Reinitialize a lock key - for cases where there is special locking or | |
241 | * special initialization of locks so that the validator gets the scope | |
242 | * of dependencies wrong: they are either too broad (they need a class-split) | |
243 | * or they are too narrow (they suffer from a false class-split): | |
244 | */ | |
245 | #define lockdep_set_class(lock, key) \ | |
4dfbb9d8 | 246 | lockdep_init_map(&(lock)->dep_map, #key, key, 0) |
fbb9ce95 | 247 | #define lockdep_set_class_and_name(lock, key, name) \ |
4dfbb9d8 PZ |
248 | lockdep_init_map(&(lock)->dep_map, name, key, 0) |
249 | #define lockdep_set_class_and_subclass(lock, key, sub) \ | |
250 | lockdep_init_map(&(lock)->dep_map, #key, key, sub) | |
251 | #define lockdep_set_subclass(lock, sub) \ | |
252 | lockdep_init_map(&(lock)->dep_map, #lock, \ | |
253 | (lock)->dep_map.key, sub) | |
fbb9ce95 IM |
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: disabled | |
267 | * 1: simple checks (freeing, held-at-exit-time, etc.) | |
268 | * 2: full validation | |
269 | */ | |
270 | extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass, | |
271 | int trylock, int read, int check, unsigned long ip); | |
272 | ||
273 | extern void lock_release(struct lockdep_map *lock, int nested, | |
274 | unsigned long ip); | |
275 | ||
276 | # define INIT_LOCKDEP .lockdep_recursion = 0, | |
277 | ||
e3a55fd1 | 278 | #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) |
d5abe669 | 279 | |
fbb9ce95 IM |
280 | #else /* !LOCKDEP */ |
281 | ||
282 | static inline void lockdep_off(void) | |
283 | { | |
284 | } | |
285 | ||
286 | static inline void lockdep_on(void) | |
287 | { | |
288 | } | |
289 | ||
fbb9ce95 IM |
290 | # define lock_acquire(l, s, t, r, c, i) do { } while (0) |
291 | # define lock_release(l, n, i) do { } while (0) | |
292 | # define lockdep_init() do { } while (0) | |
293 | # define lockdep_info() do { } while (0) | |
4dfbb9d8 | 294 | # define lockdep_init_map(lock, name, key, sub) do { (void)(key); } while (0) |
fbb9ce95 IM |
295 | # define lockdep_set_class(lock, key) do { (void)(key); } while (0) |
296 | # define lockdep_set_class_and_name(lock, key, name) \ | |
297 | do { (void)(key); } while (0) | |
4dfbb9d8 PZ |
298 | #define lockdep_set_class_and_subclass(lock, key, sub) \ |
299 | do { (void)(key); } while (0) | |
07646e21 AM |
300 | #define lockdep_set_subclass(lock, sub) do { } while (0) |
301 | ||
fbb9ce95 IM |
302 | # define INIT_LOCKDEP |
303 | # define lockdep_reset() do { debug_locks = 1; } while (0) | |
304 | # define lockdep_free_key_range(start, size) do { } while (0) | |
305 | /* | |
306 | * The class key takes no space if lockdep is disabled: | |
307 | */ | |
308 | struct lock_class_key { }; | |
d5abe669 PZ |
309 | |
310 | #define lockdep_depth(tsk) (0) | |
311 | ||
fbb9ce95 IM |
312 | #endif /* !LOCKDEP */ |
313 | ||
f20786ff PZ |
314 | #ifdef CONFIG_LOCK_STAT |
315 | ||
316 | extern void lock_contended(struct lockdep_map *lock, unsigned long ip); | |
317 | extern void lock_acquired(struct lockdep_map *lock); | |
318 | ||
319 | #define LOCK_CONTENDED(_lock, try, lock) \ | |
320 | do { \ | |
321 | if (!try(_lock)) { \ | |
322 | lock_contended(&(_lock)->dep_map, _RET_IP_); \ | |
323 | lock(_lock); \ | |
324 | lock_acquired(&(_lock)->dep_map); \ | |
325 | } \ | |
326 | } while (0) | |
327 | ||
328 | #else /* CONFIG_LOCK_STAT */ | |
329 | ||
330 | #define lock_contended(lockdep_map, ip) do {} while (0) | |
331 | #define lock_acquired(lockdep_map) do {} while (0) | |
332 | ||
333 | #define LOCK_CONTENDED(_lock, try, lock) \ | |
334 | lock(_lock) | |
335 | ||
336 | #endif /* CONFIG_LOCK_STAT */ | |
337 | ||
243c7621 IM |
338 | #if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS) |
339 | extern void early_init_irq_lock_class(void); | |
340 | #else | |
3117df04 IM |
341 | static inline void early_init_irq_lock_class(void) |
342 | { | |
343 | } | |
243c7621 IM |
344 | #endif |
345 | ||
fbb9ce95 IM |
346 | #ifdef CONFIG_TRACE_IRQFLAGS |
347 | extern void early_boot_irqs_off(void); | |
348 | extern void early_boot_irqs_on(void); | |
3117df04 | 349 | extern void print_irqtrace_events(struct task_struct *curr); |
fbb9ce95 | 350 | #else |
3117df04 IM |
351 | static inline void early_boot_irqs_off(void) |
352 | { | |
353 | } | |
354 | static inline void early_boot_irqs_on(void) | |
355 | { | |
356 | } | |
357 | static inline void print_irqtrace_events(struct task_struct *curr) | |
358 | { | |
359 | } | |
fbb9ce95 IM |
360 | #endif |
361 | ||
362 | /* | |
363 | * For trivial one-depth nesting of a lock-class, the following | |
364 | * global define can be used. (Subsystems with multiple levels | |
365 | * of nesting should define their own lock-nesting subclasses.) | |
366 | */ | |
367 | #define SINGLE_DEPTH_NESTING 1 | |
368 | ||
369 | /* | |
370 | * Map the dependency ops to NOP or to real lockdep ops, depending | |
371 | * on the per lock-class debug mode: | |
372 | */ | |
373 | ||
374 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
375 | # ifdef CONFIG_PROVE_LOCKING | |
376 | # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
377 | # else | |
378 | # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
379 | # endif | |
380 | # define spin_release(l, n, i) lock_release(l, n, i) | |
381 | #else | |
382 | # define spin_acquire(l, s, t, i) do { } while (0) | |
383 | # define spin_release(l, n, i) do { } while (0) | |
384 | #endif | |
385 | ||
386 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
387 | # ifdef CONFIG_PROVE_LOCKING | |
388 | # define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
389 | # define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 2, i) | |
390 | # else | |
391 | # define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
392 | # define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 1, i) | |
393 | # endif | |
394 | # define rwlock_release(l, n, i) lock_release(l, n, i) | |
395 | #else | |
396 | # define rwlock_acquire(l, s, t, i) do { } while (0) | |
397 | # define rwlock_acquire_read(l, s, t, i) do { } while (0) | |
398 | # define rwlock_release(l, n, i) do { } while (0) | |
399 | #endif | |
400 | ||
401 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
402 | # ifdef CONFIG_PROVE_LOCKING | |
403 | # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
404 | # else | |
405 | # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
406 | # endif | |
407 | # define mutex_release(l, n, i) lock_release(l, n, i) | |
408 | #else | |
409 | # define mutex_acquire(l, s, t, i) do { } while (0) | |
410 | # define mutex_release(l, n, i) do { } while (0) | |
411 | #endif | |
412 | ||
413 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
414 | # ifdef CONFIG_PROVE_LOCKING | |
415 | # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i) | |
416 | # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, i) | |
417 | # else | |
418 | # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i) | |
419 | # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, i) | |
420 | # endif | |
421 | # define rwsem_release(l, n, i) lock_release(l, n, i) | |
422 | #else | |
423 | # define rwsem_acquire(l, s, t, i) do { } while (0) | |
424 | # define rwsem_acquire_read(l, s, t, i) do { } while (0) | |
425 | # define rwsem_release(l, n, i) do { } while (0) | |
426 | #endif | |
427 | ||
428 | #endif /* __LINUX_LOCKDEP_H */ |