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