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