Commit | Line | Data |
---|---|---|
3ac7fe5a TG |
1 | /* |
2 | * Generic infrastructure for lifetime debugging of objects. | |
3 | * | |
4 | * Started by Thomas Gleixner | |
5 | * | |
6 | * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de> | |
7 | * | |
8 | * For licencing details see kernel-base/COPYING | |
9 | */ | |
10 | #include <linux/debugobjects.h> | |
11 | #include <linux/interrupt.h> | |
d43c36dc | 12 | #include <linux/sched.h> |
3ac7fe5a TG |
13 | #include <linux/seq_file.h> |
14 | #include <linux/debugfs.h> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
3ac7fe5a TG |
16 | #include <linux/hash.h> |
17 | ||
18 | #define ODEBUG_HASH_BITS 14 | |
19 | #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) | |
20 | ||
21 | #define ODEBUG_POOL_SIZE 512 | |
22 | #define ODEBUG_POOL_MIN_LEVEL 256 | |
23 | ||
24 | #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT | |
25 | #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) | |
26 | #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) | |
27 | ||
28 | struct debug_bucket { | |
29 | struct hlist_head list; | |
aef9cb05 | 30 | raw_spinlock_t lock; |
3ac7fe5a TG |
31 | }; |
32 | ||
33 | static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; | |
34 | ||
1be1cb7b | 35 | static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata; |
3ac7fe5a | 36 | |
aef9cb05 | 37 | static DEFINE_RAW_SPINLOCK(pool_lock); |
3ac7fe5a TG |
38 | |
39 | static HLIST_HEAD(obj_pool); | |
40 | ||
41 | static int obj_pool_min_free = ODEBUG_POOL_SIZE; | |
42 | static int obj_pool_free = ODEBUG_POOL_SIZE; | |
43 | static int obj_pool_used; | |
44 | static int obj_pool_max_used; | |
45 | static struct kmem_cache *obj_cache; | |
46 | ||
47 | static int debug_objects_maxchain __read_mostly; | |
48 | static int debug_objects_fixups __read_mostly; | |
49 | static int debug_objects_warnings __read_mostly; | |
3ae70205 IM |
50 | static int debug_objects_enabled __read_mostly |
51 | = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; | |
52 | ||
3ac7fe5a TG |
53 | static struct debug_obj_descr *descr_test __read_mostly; |
54 | ||
337fff8b TG |
55 | static void free_obj_work(struct work_struct *work); |
56 | static DECLARE_WORK(debug_obj_work, free_obj_work); | |
57 | ||
3ac7fe5a TG |
58 | static int __init enable_object_debug(char *str) |
59 | { | |
60 | debug_objects_enabled = 1; | |
61 | return 0; | |
62 | } | |
3e8ebb5c KM |
63 | |
64 | static int __init disable_object_debug(char *str) | |
65 | { | |
66 | debug_objects_enabled = 0; | |
67 | return 0; | |
68 | } | |
69 | ||
3ac7fe5a | 70 | early_param("debug_objects", enable_object_debug); |
3e8ebb5c | 71 | early_param("no_debug_objects", disable_object_debug); |
3ac7fe5a TG |
72 | |
73 | static const char *obj_states[ODEBUG_STATE_MAX] = { | |
74 | [ODEBUG_STATE_NONE] = "none", | |
75 | [ODEBUG_STATE_INIT] = "initialized", | |
76 | [ODEBUG_STATE_INACTIVE] = "inactive", | |
77 | [ODEBUG_STATE_ACTIVE] = "active", | |
78 | [ODEBUG_STATE_DESTROYED] = "destroyed", | |
79 | [ODEBUG_STATE_NOTAVAILABLE] = "not available", | |
80 | }; | |
81 | ||
1fda107d | 82 | static void fill_pool(void) |
3ac7fe5a TG |
83 | { |
84 | gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; | |
85 | struct debug_obj *new; | |
50db04dd | 86 | unsigned long flags; |
3ac7fe5a TG |
87 | |
88 | if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL)) | |
1fda107d | 89 | return; |
3ac7fe5a TG |
90 | |
91 | if (unlikely(!obj_cache)) | |
1fda107d | 92 | return; |
3ac7fe5a TG |
93 | |
94 | while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) { | |
95 | ||
96 | new = kmem_cache_zalloc(obj_cache, gfp); | |
97 | if (!new) | |
3340808c | 98 | return; |
3ac7fe5a | 99 | |
aef9cb05 | 100 | raw_spin_lock_irqsave(&pool_lock, flags); |
3ac7fe5a TG |
101 | hlist_add_head(&new->node, &obj_pool); |
102 | obj_pool_free++; | |
aef9cb05 | 103 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
3ac7fe5a | 104 | } |
3ac7fe5a TG |
105 | } |
106 | ||
107 | /* | |
108 | * Lookup an object in the hash bucket. | |
109 | */ | |
110 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) | |
111 | { | |
112 | struct hlist_node *node; | |
113 | struct debug_obj *obj; | |
114 | int cnt = 0; | |
115 | ||
116 | hlist_for_each_entry(obj, node, &b->list, node) { | |
117 | cnt++; | |
118 | if (obj->object == addr) | |
119 | return obj; | |
120 | } | |
121 | if (cnt > debug_objects_maxchain) | |
122 | debug_objects_maxchain = cnt; | |
123 | ||
124 | return NULL; | |
125 | } | |
126 | ||
127 | /* | |
50db04dd | 128 | * Allocate a new object. If the pool is empty, switch off the debugger. |
673d62cc | 129 | * Must be called with interrupts disabled. |
3ac7fe5a TG |
130 | */ |
131 | static struct debug_obj * | |
132 | alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) | |
133 | { | |
134 | struct debug_obj *obj = NULL; | |
3ac7fe5a | 135 | |
aef9cb05 | 136 | raw_spin_lock(&pool_lock); |
3ac7fe5a TG |
137 | if (obj_pool.first) { |
138 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); | |
139 | ||
140 | obj->object = addr; | |
141 | obj->descr = descr; | |
142 | obj->state = ODEBUG_STATE_NONE; | |
a5d8e467 | 143 | obj->astate = 0; |
3ac7fe5a TG |
144 | hlist_del(&obj->node); |
145 | ||
146 | hlist_add_head(&obj->node, &b->list); | |
147 | ||
148 | obj_pool_used++; | |
149 | if (obj_pool_used > obj_pool_max_used) | |
150 | obj_pool_max_used = obj_pool_used; | |
151 | ||
152 | obj_pool_free--; | |
153 | if (obj_pool_free < obj_pool_min_free) | |
154 | obj_pool_min_free = obj_pool_free; | |
155 | } | |
aef9cb05 | 156 | raw_spin_unlock(&pool_lock); |
3ac7fe5a | 157 | |
3ac7fe5a TG |
158 | return obj; |
159 | } | |
160 | ||
161 | /* | |
337fff8b | 162 | * workqueue function to free objects. |
3ac7fe5a | 163 | */ |
337fff8b | 164 | static void free_obj_work(struct work_struct *work) |
3ac7fe5a | 165 | { |
337fff8b | 166 | struct debug_obj *obj; |
673d62cc | 167 | unsigned long flags; |
3ac7fe5a | 168 | |
aef9cb05 | 169 | raw_spin_lock_irqsave(&pool_lock, flags); |
337fff8b TG |
170 | while (obj_pool_free > ODEBUG_POOL_SIZE) { |
171 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); | |
172 | hlist_del(&obj->node); | |
173 | obj_pool_free--; | |
174 | /* | |
175 | * We release pool_lock across kmem_cache_free() to | |
176 | * avoid contention on pool_lock. | |
177 | */ | |
aef9cb05 | 178 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
3ac7fe5a | 179 | kmem_cache_free(obj_cache, obj); |
aef9cb05 | 180 | raw_spin_lock_irqsave(&pool_lock, flags); |
3ac7fe5a | 181 | } |
aef9cb05 | 182 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
337fff8b TG |
183 | } |
184 | ||
185 | /* | |
186 | * Put the object back into the pool and schedule work to free objects | |
187 | * if necessary. | |
188 | */ | |
189 | static void free_object(struct debug_obj *obj) | |
190 | { | |
191 | unsigned long flags; | |
192 | int sched = 0; | |
193 | ||
aef9cb05 | 194 | raw_spin_lock_irqsave(&pool_lock, flags); |
337fff8b TG |
195 | /* |
196 | * schedule work when the pool is filled and the cache is | |
197 | * initialized: | |
198 | */ | |
199 | if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache) | |
161b6ae0 | 200 | sched = keventd_up() && !work_pending(&debug_obj_work); |
337fff8b TG |
201 | hlist_add_head(&obj->node, &obj_pool); |
202 | obj_pool_free++; | |
203 | obj_pool_used--; | |
aef9cb05 | 204 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
337fff8b TG |
205 | if (sched) |
206 | schedule_work(&debug_obj_work); | |
3ac7fe5a TG |
207 | } |
208 | ||
209 | /* | |
210 | * We run out of memory. That means we probably have tons of objects | |
211 | * allocated. | |
212 | */ | |
213 | static void debug_objects_oom(void) | |
214 | { | |
215 | struct debug_bucket *db = obj_hash; | |
216 | struct hlist_node *node, *tmp; | |
673d62cc | 217 | HLIST_HEAD(freelist); |
3ac7fe5a TG |
218 | struct debug_obj *obj; |
219 | unsigned long flags; | |
220 | int i; | |
221 | ||
222 | printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n"); | |
223 | ||
224 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { | |
aef9cb05 | 225 | raw_spin_lock_irqsave(&db->lock, flags); |
673d62cc | 226 | hlist_move_list(&db->list, &freelist); |
aef9cb05 | 227 | raw_spin_unlock_irqrestore(&db->lock, flags); |
673d62cc VN |
228 | |
229 | /* Now free them */ | |
230 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { | |
3ac7fe5a TG |
231 | hlist_del(&obj->node); |
232 | free_object(obj); | |
233 | } | |
3ac7fe5a TG |
234 | } |
235 | } | |
236 | ||
237 | /* | |
238 | * We use the pfn of the address for the hash. That way we can check | |
239 | * for freed objects simply by checking the affected bucket. | |
240 | */ | |
241 | static struct debug_bucket *get_bucket(unsigned long addr) | |
242 | { | |
243 | unsigned long hash; | |
244 | ||
245 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); | |
246 | return &obj_hash[hash]; | |
247 | } | |
248 | ||
249 | static void debug_print_object(struct debug_obj *obj, char *msg) | |
250 | { | |
99777288 | 251 | struct debug_obj_descr *descr = obj->descr; |
3ac7fe5a TG |
252 | static int limit; |
253 | ||
99777288 SG |
254 | if (limit < 5 && descr != descr_test) { |
255 | void *hint = descr->debug_hint ? | |
256 | descr->debug_hint(obj->object) : NULL; | |
3ac7fe5a | 257 | limit++; |
a5d8e467 | 258 | WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " |
99777288 | 259 | "object type: %s hint: %pS\n", |
a5d8e467 | 260 | msg, obj_states[obj->state], obj->astate, |
99777288 | 261 | descr->name, hint); |
3ac7fe5a TG |
262 | } |
263 | debug_objects_warnings++; | |
264 | } | |
265 | ||
266 | /* | |
267 | * Try to repair the damage, so we have a better chance to get useful | |
268 | * debug output. | |
269 | */ | |
feac18dd | 270 | static int |
3ac7fe5a TG |
271 | debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), |
272 | void * addr, enum debug_obj_state state) | |
273 | { | |
feac18dd SB |
274 | int fixed = 0; |
275 | ||
3ac7fe5a | 276 | if (fixup) |
feac18dd SB |
277 | fixed = fixup(addr, state); |
278 | debug_objects_fixups += fixed; | |
279 | return fixed; | |
3ac7fe5a TG |
280 | } |
281 | ||
282 | static void debug_object_is_on_stack(void *addr, int onstack) | |
283 | { | |
3ac7fe5a TG |
284 | int is_on_stack; |
285 | static int limit; | |
286 | ||
287 | if (limit > 4) | |
288 | return; | |
289 | ||
8b05c7e6 | 290 | is_on_stack = object_is_on_stack(addr); |
3ac7fe5a TG |
291 | if (is_on_stack == onstack) |
292 | return; | |
293 | ||
294 | limit++; | |
295 | if (is_on_stack) | |
296 | printk(KERN_WARNING | |
297 | "ODEBUG: object is on stack, but not annotated\n"); | |
298 | else | |
299 | printk(KERN_WARNING | |
300 | "ODEBUG: object is not on stack, but annotated\n"); | |
301 | WARN_ON(1); | |
302 | } | |
303 | ||
304 | static void | |
305 | __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) | |
306 | { | |
307 | enum debug_obj_state state; | |
308 | struct debug_bucket *db; | |
309 | struct debug_obj *obj; | |
310 | unsigned long flags; | |
311 | ||
50db04dd VN |
312 | fill_pool(); |
313 | ||
3ac7fe5a TG |
314 | db = get_bucket((unsigned long) addr); |
315 | ||
aef9cb05 | 316 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
317 | |
318 | obj = lookup_object(addr, db); | |
319 | if (!obj) { | |
320 | obj = alloc_object(addr, db, descr); | |
321 | if (!obj) { | |
322 | debug_objects_enabled = 0; | |
aef9cb05 | 323 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
324 | debug_objects_oom(); |
325 | return; | |
326 | } | |
327 | debug_object_is_on_stack(addr, onstack); | |
328 | } | |
329 | ||
330 | switch (obj->state) { | |
331 | case ODEBUG_STATE_NONE: | |
332 | case ODEBUG_STATE_INIT: | |
333 | case ODEBUG_STATE_INACTIVE: | |
334 | obj->state = ODEBUG_STATE_INIT; | |
335 | break; | |
336 | ||
337 | case ODEBUG_STATE_ACTIVE: | |
338 | debug_print_object(obj, "init"); | |
339 | state = obj->state; | |
aef9cb05 | 340 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
341 | debug_object_fixup(descr->fixup_init, addr, state); |
342 | return; | |
343 | ||
344 | case ODEBUG_STATE_DESTROYED: | |
345 | debug_print_object(obj, "init"); | |
346 | break; | |
347 | default: | |
348 | break; | |
349 | } | |
350 | ||
aef9cb05 | 351 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
352 | } |
353 | ||
354 | /** | |
355 | * debug_object_init - debug checks when an object is initialized | |
356 | * @addr: address of the object | |
357 | * @descr: pointer to an object specific debug description structure | |
358 | */ | |
359 | void debug_object_init(void *addr, struct debug_obj_descr *descr) | |
360 | { | |
361 | if (!debug_objects_enabled) | |
362 | return; | |
363 | ||
364 | __debug_object_init(addr, descr, 0); | |
365 | } | |
366 | ||
367 | /** | |
368 | * debug_object_init_on_stack - debug checks when an object on stack is | |
369 | * initialized | |
370 | * @addr: address of the object | |
371 | * @descr: pointer to an object specific debug description structure | |
372 | */ | |
373 | void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) | |
374 | { | |
375 | if (!debug_objects_enabled) | |
376 | return; | |
377 | ||
378 | __debug_object_init(addr, descr, 1); | |
379 | } | |
380 | ||
381 | /** | |
382 | * debug_object_activate - debug checks when an object is activated | |
383 | * @addr: address of the object | |
384 | * @descr: pointer to an object specific debug description structure | |
385 | */ | |
386 | void debug_object_activate(void *addr, struct debug_obj_descr *descr) | |
387 | { | |
388 | enum debug_obj_state state; | |
389 | struct debug_bucket *db; | |
390 | struct debug_obj *obj; | |
391 | unsigned long flags; | |
feac18dd SB |
392 | struct debug_obj o = { .object = addr, |
393 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
394 | .descr = descr }; | |
3ac7fe5a TG |
395 | |
396 | if (!debug_objects_enabled) | |
397 | return; | |
398 | ||
399 | db = get_bucket((unsigned long) addr); | |
400 | ||
aef9cb05 | 401 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
402 | |
403 | obj = lookup_object(addr, db); | |
404 | if (obj) { | |
405 | switch (obj->state) { | |
406 | case ODEBUG_STATE_INIT: | |
407 | case ODEBUG_STATE_INACTIVE: | |
408 | obj->state = ODEBUG_STATE_ACTIVE; | |
409 | break; | |
410 | ||
411 | case ODEBUG_STATE_ACTIVE: | |
412 | debug_print_object(obj, "activate"); | |
413 | state = obj->state; | |
aef9cb05 | 414 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
415 | debug_object_fixup(descr->fixup_activate, addr, state); |
416 | return; | |
417 | ||
418 | case ODEBUG_STATE_DESTROYED: | |
419 | debug_print_object(obj, "activate"); | |
420 | break; | |
421 | default: | |
422 | break; | |
423 | } | |
aef9cb05 | 424 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
425 | return; |
426 | } | |
427 | ||
aef9cb05 | 428 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
429 | /* |
430 | * This happens when a static object is activated. We | |
431 | * let the type specific code decide whether this is | |
432 | * true or not. | |
433 | */ | |
feac18dd SB |
434 | if (debug_object_fixup(descr->fixup_activate, addr, |
435 | ODEBUG_STATE_NOTAVAILABLE)) | |
436 | debug_print_object(&o, "activate"); | |
3ac7fe5a TG |
437 | } |
438 | ||
439 | /** | |
440 | * debug_object_deactivate - debug checks when an object is deactivated | |
441 | * @addr: address of the object | |
442 | * @descr: pointer to an object specific debug description structure | |
443 | */ | |
444 | void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) | |
445 | { | |
446 | struct debug_bucket *db; | |
447 | struct debug_obj *obj; | |
448 | unsigned long flags; | |
449 | ||
450 | if (!debug_objects_enabled) | |
451 | return; | |
452 | ||
453 | db = get_bucket((unsigned long) addr); | |
454 | ||
aef9cb05 | 455 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
456 | |
457 | obj = lookup_object(addr, db); | |
458 | if (obj) { | |
459 | switch (obj->state) { | |
460 | case ODEBUG_STATE_INIT: | |
461 | case ODEBUG_STATE_INACTIVE: | |
462 | case ODEBUG_STATE_ACTIVE: | |
a5d8e467 MD |
463 | if (!obj->astate) |
464 | obj->state = ODEBUG_STATE_INACTIVE; | |
465 | else | |
466 | debug_print_object(obj, "deactivate"); | |
3ac7fe5a TG |
467 | break; |
468 | ||
469 | case ODEBUG_STATE_DESTROYED: | |
470 | debug_print_object(obj, "deactivate"); | |
471 | break; | |
472 | default: | |
473 | break; | |
474 | } | |
475 | } else { | |
476 | struct debug_obj o = { .object = addr, | |
477 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
478 | .descr = descr }; | |
479 | ||
480 | debug_print_object(&o, "deactivate"); | |
481 | } | |
482 | ||
aef9cb05 | 483 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
484 | } |
485 | ||
486 | /** | |
487 | * debug_object_destroy - debug checks when an object is destroyed | |
488 | * @addr: address of the object | |
489 | * @descr: pointer to an object specific debug description structure | |
490 | */ | |
491 | void debug_object_destroy(void *addr, struct debug_obj_descr *descr) | |
492 | { | |
493 | enum debug_obj_state state; | |
494 | struct debug_bucket *db; | |
495 | struct debug_obj *obj; | |
496 | unsigned long flags; | |
497 | ||
498 | if (!debug_objects_enabled) | |
499 | return; | |
500 | ||
501 | db = get_bucket((unsigned long) addr); | |
502 | ||
aef9cb05 | 503 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
504 | |
505 | obj = lookup_object(addr, db); | |
506 | if (!obj) | |
507 | goto out_unlock; | |
508 | ||
509 | switch (obj->state) { | |
510 | case ODEBUG_STATE_NONE: | |
511 | case ODEBUG_STATE_INIT: | |
512 | case ODEBUG_STATE_INACTIVE: | |
513 | obj->state = ODEBUG_STATE_DESTROYED; | |
514 | break; | |
515 | case ODEBUG_STATE_ACTIVE: | |
516 | debug_print_object(obj, "destroy"); | |
517 | state = obj->state; | |
aef9cb05 | 518 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
519 | debug_object_fixup(descr->fixup_destroy, addr, state); |
520 | return; | |
521 | ||
522 | case ODEBUG_STATE_DESTROYED: | |
523 | debug_print_object(obj, "destroy"); | |
524 | break; | |
525 | default: | |
526 | break; | |
527 | } | |
528 | out_unlock: | |
aef9cb05 | 529 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
530 | } |
531 | ||
532 | /** | |
533 | * debug_object_free - debug checks when an object is freed | |
534 | * @addr: address of the object | |
535 | * @descr: pointer to an object specific debug description structure | |
536 | */ | |
537 | void debug_object_free(void *addr, struct debug_obj_descr *descr) | |
538 | { | |
539 | enum debug_obj_state state; | |
540 | struct debug_bucket *db; | |
541 | struct debug_obj *obj; | |
542 | unsigned long flags; | |
543 | ||
544 | if (!debug_objects_enabled) | |
545 | return; | |
546 | ||
547 | db = get_bucket((unsigned long) addr); | |
548 | ||
aef9cb05 | 549 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
550 | |
551 | obj = lookup_object(addr, db); | |
552 | if (!obj) | |
553 | goto out_unlock; | |
554 | ||
555 | switch (obj->state) { | |
556 | case ODEBUG_STATE_ACTIVE: | |
557 | debug_print_object(obj, "free"); | |
558 | state = obj->state; | |
aef9cb05 | 559 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
560 | debug_object_fixup(descr->fixup_free, addr, state); |
561 | return; | |
562 | default: | |
563 | hlist_del(&obj->node); | |
aef9cb05 | 564 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a | 565 | free_object(obj); |
673d62cc | 566 | return; |
3ac7fe5a TG |
567 | } |
568 | out_unlock: | |
aef9cb05 | 569 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
570 | } |
571 | ||
b84d435c CC |
572 | /** |
573 | * debug_object_assert_init - debug checks when object should be init-ed | |
574 | * @addr: address of the object | |
575 | * @descr: pointer to an object specific debug description structure | |
576 | */ | |
577 | void debug_object_assert_init(void *addr, struct debug_obj_descr *descr) | |
578 | { | |
579 | struct debug_bucket *db; | |
580 | struct debug_obj *obj; | |
581 | unsigned long flags; | |
582 | ||
583 | if (!debug_objects_enabled) | |
584 | return; | |
585 | ||
586 | db = get_bucket((unsigned long) addr); | |
587 | ||
588 | raw_spin_lock_irqsave(&db->lock, flags); | |
589 | ||
590 | obj = lookup_object(addr, db); | |
591 | if (!obj) { | |
592 | struct debug_obj o = { .object = addr, | |
593 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
594 | .descr = descr }; | |
595 | ||
596 | raw_spin_unlock_irqrestore(&db->lock, flags); | |
597 | /* | |
598 | * Maybe the object is static. Let the type specific | |
599 | * code decide what to do. | |
600 | */ | |
601 | if (debug_object_fixup(descr->fixup_assert_init, addr, | |
602 | ODEBUG_STATE_NOTAVAILABLE)) | |
603 | debug_print_object(&o, "assert_init"); | |
604 | return; | |
605 | } | |
606 | ||
607 | raw_spin_unlock_irqrestore(&db->lock, flags); | |
608 | } | |
609 | ||
a5d8e467 MD |
610 | /** |
611 | * debug_object_active_state - debug checks object usage state machine | |
612 | * @addr: address of the object | |
613 | * @descr: pointer to an object specific debug description structure | |
614 | * @expect: expected state | |
615 | * @next: state to move to if expected state is found | |
616 | */ | |
617 | void | |
618 | debug_object_active_state(void *addr, struct debug_obj_descr *descr, | |
619 | unsigned int expect, unsigned int next) | |
620 | { | |
621 | struct debug_bucket *db; | |
622 | struct debug_obj *obj; | |
623 | unsigned long flags; | |
624 | ||
625 | if (!debug_objects_enabled) | |
626 | return; | |
627 | ||
628 | db = get_bucket((unsigned long) addr); | |
629 | ||
630 | raw_spin_lock_irqsave(&db->lock, flags); | |
631 | ||
632 | obj = lookup_object(addr, db); | |
633 | if (obj) { | |
634 | switch (obj->state) { | |
635 | case ODEBUG_STATE_ACTIVE: | |
636 | if (obj->astate == expect) | |
637 | obj->astate = next; | |
638 | else | |
639 | debug_print_object(obj, "active_state"); | |
640 | break; | |
641 | ||
642 | default: | |
643 | debug_print_object(obj, "active_state"); | |
644 | break; | |
645 | } | |
646 | } else { | |
647 | struct debug_obj o = { .object = addr, | |
648 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
649 | .descr = descr }; | |
650 | ||
651 | debug_print_object(&o, "active_state"); | |
652 | } | |
653 | ||
654 | raw_spin_unlock_irqrestore(&db->lock, flags); | |
655 | } | |
656 | ||
3ac7fe5a TG |
657 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
658 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) | |
659 | { | |
660 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; | |
661 | struct hlist_node *node, *tmp; | |
673d62cc | 662 | HLIST_HEAD(freelist); |
3ac7fe5a TG |
663 | struct debug_obj_descr *descr; |
664 | enum debug_obj_state state; | |
665 | struct debug_bucket *db; | |
666 | struct debug_obj *obj; | |
667 | int cnt; | |
668 | ||
669 | saddr = (unsigned long) address; | |
670 | eaddr = saddr + size; | |
671 | paddr = saddr & ODEBUG_CHUNK_MASK; | |
672 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); | |
673 | chunks >>= ODEBUG_CHUNK_SHIFT; | |
674 | ||
675 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { | |
676 | db = get_bucket(paddr); | |
677 | ||
678 | repeat: | |
679 | cnt = 0; | |
aef9cb05 | 680 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
681 | hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { |
682 | cnt++; | |
683 | oaddr = (unsigned long) obj->object; | |
684 | if (oaddr < saddr || oaddr >= eaddr) | |
685 | continue; | |
686 | ||
687 | switch (obj->state) { | |
688 | case ODEBUG_STATE_ACTIVE: | |
689 | debug_print_object(obj, "free"); | |
690 | descr = obj->descr; | |
691 | state = obj->state; | |
aef9cb05 | 692 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
693 | debug_object_fixup(descr->fixup_free, |
694 | (void *) oaddr, state); | |
695 | goto repeat; | |
696 | default: | |
697 | hlist_del(&obj->node); | |
673d62cc | 698 | hlist_add_head(&obj->node, &freelist); |
3ac7fe5a TG |
699 | break; |
700 | } | |
701 | } | |
aef9cb05 | 702 | raw_spin_unlock_irqrestore(&db->lock, flags); |
673d62cc VN |
703 | |
704 | /* Now free them */ | |
705 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { | |
706 | hlist_del(&obj->node); | |
707 | free_object(obj); | |
708 | } | |
709 | ||
3ac7fe5a TG |
710 | if (cnt > debug_objects_maxchain) |
711 | debug_objects_maxchain = cnt; | |
712 | } | |
713 | } | |
714 | ||
715 | void debug_check_no_obj_freed(const void *address, unsigned long size) | |
716 | { | |
717 | if (debug_objects_enabled) | |
718 | __debug_check_no_obj_freed(address, size); | |
719 | } | |
720 | #endif | |
721 | ||
722 | #ifdef CONFIG_DEBUG_FS | |
723 | ||
724 | static int debug_stats_show(struct seq_file *m, void *v) | |
725 | { | |
726 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); | |
727 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); | |
728 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); | |
729 | seq_printf(m, "pool_free :%d\n", obj_pool_free); | |
730 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); | |
731 | seq_printf(m, "pool_used :%d\n", obj_pool_used); | |
732 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); | |
733 | return 0; | |
734 | } | |
735 | ||
736 | static int debug_stats_open(struct inode *inode, struct file *filp) | |
737 | { | |
738 | return single_open(filp, debug_stats_show, NULL); | |
739 | } | |
740 | ||
741 | static const struct file_operations debug_stats_fops = { | |
742 | .open = debug_stats_open, | |
743 | .read = seq_read, | |
744 | .llseek = seq_lseek, | |
745 | .release = single_release, | |
746 | }; | |
747 | ||
748 | static int __init debug_objects_init_debugfs(void) | |
749 | { | |
750 | struct dentry *dbgdir, *dbgstats; | |
751 | ||
752 | if (!debug_objects_enabled) | |
753 | return 0; | |
754 | ||
755 | dbgdir = debugfs_create_dir("debug_objects", NULL); | |
756 | if (!dbgdir) | |
757 | return -ENOMEM; | |
758 | ||
759 | dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, | |
760 | &debug_stats_fops); | |
761 | if (!dbgstats) | |
762 | goto err; | |
763 | ||
764 | return 0; | |
765 | ||
766 | err: | |
767 | debugfs_remove(dbgdir); | |
768 | ||
769 | return -ENOMEM; | |
770 | } | |
771 | __initcall(debug_objects_init_debugfs); | |
772 | ||
773 | #else | |
774 | static inline void debug_objects_init_debugfs(void) { } | |
775 | #endif | |
776 | ||
777 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST | |
778 | ||
779 | /* Random data structure for the self test */ | |
780 | struct self_test { | |
781 | unsigned long dummy1[6]; | |
782 | int static_init; | |
783 | unsigned long dummy2[3]; | |
784 | }; | |
785 | ||
786 | static __initdata struct debug_obj_descr descr_type_test; | |
787 | ||
788 | /* | |
789 | * fixup_init is called when: | |
790 | * - an active object is initialized | |
791 | */ | |
792 | static int __init fixup_init(void *addr, enum debug_obj_state state) | |
793 | { | |
794 | struct self_test *obj = addr; | |
795 | ||
796 | switch (state) { | |
797 | case ODEBUG_STATE_ACTIVE: | |
798 | debug_object_deactivate(obj, &descr_type_test); | |
799 | debug_object_init(obj, &descr_type_test); | |
800 | return 1; | |
801 | default: | |
802 | return 0; | |
803 | } | |
804 | } | |
805 | ||
806 | /* | |
807 | * fixup_activate is called when: | |
808 | * - an active object is activated | |
809 | * - an unknown object is activated (might be a statically initialized object) | |
810 | */ | |
811 | static int __init fixup_activate(void *addr, enum debug_obj_state state) | |
812 | { | |
813 | struct self_test *obj = addr; | |
814 | ||
815 | switch (state) { | |
816 | case ODEBUG_STATE_NOTAVAILABLE: | |
817 | if (obj->static_init == 1) { | |
818 | debug_object_init(obj, &descr_type_test); | |
819 | debug_object_activate(obj, &descr_type_test); | |
9f78ff00 | 820 | return 0; |
3ac7fe5a | 821 | } |
9f78ff00 | 822 | return 1; |
3ac7fe5a TG |
823 | |
824 | case ODEBUG_STATE_ACTIVE: | |
825 | debug_object_deactivate(obj, &descr_type_test); | |
826 | debug_object_activate(obj, &descr_type_test); | |
827 | return 1; | |
828 | ||
829 | default: | |
830 | return 0; | |
831 | } | |
832 | } | |
833 | ||
834 | /* | |
835 | * fixup_destroy is called when: | |
836 | * - an active object is destroyed | |
837 | */ | |
838 | static int __init fixup_destroy(void *addr, enum debug_obj_state state) | |
839 | { | |
840 | struct self_test *obj = addr; | |
841 | ||
842 | switch (state) { | |
843 | case ODEBUG_STATE_ACTIVE: | |
844 | debug_object_deactivate(obj, &descr_type_test); | |
845 | debug_object_destroy(obj, &descr_type_test); | |
846 | return 1; | |
847 | default: | |
848 | return 0; | |
849 | } | |
850 | } | |
851 | ||
852 | /* | |
853 | * fixup_free is called when: | |
854 | * - an active object is freed | |
855 | */ | |
856 | static int __init fixup_free(void *addr, enum debug_obj_state state) | |
857 | { | |
858 | struct self_test *obj = addr; | |
859 | ||
860 | switch (state) { | |
861 | case ODEBUG_STATE_ACTIVE: | |
862 | debug_object_deactivate(obj, &descr_type_test); | |
863 | debug_object_free(obj, &descr_type_test); | |
864 | return 1; | |
865 | default: | |
866 | return 0; | |
867 | } | |
868 | } | |
869 | ||
1fb2f77c | 870 | static int __init |
3ac7fe5a TG |
871 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) |
872 | { | |
873 | struct debug_bucket *db; | |
874 | struct debug_obj *obj; | |
875 | unsigned long flags; | |
876 | int res = -EINVAL; | |
877 | ||
878 | db = get_bucket((unsigned long) addr); | |
879 | ||
aef9cb05 | 880 | raw_spin_lock_irqsave(&db->lock, flags); |
3ac7fe5a TG |
881 | |
882 | obj = lookup_object(addr, db); | |
883 | if (!obj && state != ODEBUG_STATE_NONE) { | |
5cd2b459 | 884 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); |
3ac7fe5a TG |
885 | goto out; |
886 | } | |
887 | if (obj && obj->state != state) { | |
5cd2b459 | 888 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", |
3ac7fe5a | 889 | obj->state, state); |
3ac7fe5a TG |
890 | goto out; |
891 | } | |
892 | if (fixups != debug_objects_fixups) { | |
5cd2b459 | 893 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", |
3ac7fe5a | 894 | fixups, debug_objects_fixups); |
3ac7fe5a TG |
895 | goto out; |
896 | } | |
897 | if (warnings != debug_objects_warnings) { | |
5cd2b459 | 898 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", |
3ac7fe5a | 899 | warnings, debug_objects_warnings); |
3ac7fe5a TG |
900 | goto out; |
901 | } | |
902 | res = 0; | |
903 | out: | |
aef9cb05 | 904 | raw_spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a TG |
905 | if (res) |
906 | debug_objects_enabled = 0; | |
907 | return res; | |
908 | } | |
909 | ||
910 | static __initdata struct debug_obj_descr descr_type_test = { | |
911 | .name = "selftest", | |
912 | .fixup_init = fixup_init, | |
913 | .fixup_activate = fixup_activate, | |
914 | .fixup_destroy = fixup_destroy, | |
915 | .fixup_free = fixup_free, | |
916 | }; | |
917 | ||
918 | static __initdata struct self_test obj = { .static_init = 0 }; | |
919 | ||
920 | static void __init debug_objects_selftest(void) | |
921 | { | |
922 | int fixups, oldfixups, warnings, oldwarnings; | |
923 | unsigned long flags; | |
924 | ||
925 | local_irq_save(flags); | |
926 | ||
927 | fixups = oldfixups = debug_objects_fixups; | |
928 | warnings = oldwarnings = debug_objects_warnings; | |
929 | descr_test = &descr_type_test; | |
930 | ||
931 | debug_object_init(&obj, &descr_type_test); | |
932 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
933 | goto out; | |
934 | debug_object_activate(&obj, &descr_type_test); | |
935 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
936 | goto out; | |
937 | debug_object_activate(&obj, &descr_type_test); | |
938 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) | |
939 | goto out; | |
940 | debug_object_deactivate(&obj, &descr_type_test); | |
941 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) | |
942 | goto out; | |
943 | debug_object_destroy(&obj, &descr_type_test); | |
944 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) | |
945 | goto out; | |
946 | debug_object_init(&obj, &descr_type_test); | |
947 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
948 | goto out; | |
949 | debug_object_activate(&obj, &descr_type_test); | |
950 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
951 | goto out; | |
952 | debug_object_deactivate(&obj, &descr_type_test); | |
953 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
954 | goto out; | |
955 | debug_object_free(&obj, &descr_type_test); | |
956 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
957 | goto out; | |
958 | ||
959 | obj.static_init = 1; | |
960 | debug_object_activate(&obj, &descr_type_test); | |
9f78ff00 | 961 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
3ac7fe5a TG |
962 | goto out; |
963 | debug_object_init(&obj, &descr_type_test); | |
964 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) | |
965 | goto out; | |
966 | debug_object_free(&obj, &descr_type_test); | |
967 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
968 | goto out; | |
969 | ||
970 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
971 | debug_object_init(&obj, &descr_type_test); | |
972 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
973 | goto out; | |
974 | debug_object_activate(&obj, &descr_type_test); | |
975 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
976 | goto out; | |
977 | __debug_check_no_obj_freed(&obj, sizeof(obj)); | |
978 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) | |
979 | goto out; | |
980 | #endif | |
981 | printk(KERN_INFO "ODEBUG: selftest passed\n"); | |
982 | ||
983 | out: | |
984 | debug_objects_fixups = oldfixups; | |
985 | debug_objects_warnings = oldwarnings; | |
986 | descr_test = NULL; | |
987 | ||
988 | local_irq_restore(flags); | |
989 | } | |
990 | #else | |
991 | static inline void debug_objects_selftest(void) { } | |
992 | #endif | |
993 | ||
994 | /* | |
995 | * Called during early boot to initialize the hash buckets and link | |
996 | * the static object pool objects into the poll list. After this call | |
997 | * the object tracker is fully operational. | |
998 | */ | |
999 | void __init debug_objects_early_init(void) | |
1000 | { | |
1001 | int i; | |
1002 | ||
1003 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) | |
aef9cb05 | 1004 | raw_spin_lock_init(&obj_hash[i].lock); |
3ac7fe5a TG |
1005 | |
1006 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) | |
1007 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); | |
1008 | } | |
1009 | ||
1be1cb7b TG |
1010 | /* |
1011 | * Convert the statically allocated objects to dynamic ones: | |
1012 | */ | |
1fb2f77c | 1013 | static int __init debug_objects_replace_static_objects(void) |
1be1cb7b TG |
1014 | { |
1015 | struct debug_bucket *db = obj_hash; | |
1016 | struct hlist_node *node, *tmp; | |
1017 | struct debug_obj *obj, *new; | |
1018 | HLIST_HEAD(objects); | |
1019 | int i, cnt = 0; | |
1020 | ||
1021 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) { | |
1022 | obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL); | |
1023 | if (!obj) | |
1024 | goto free; | |
1025 | hlist_add_head(&obj->node, &objects); | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * When debug_objects_mem_init() is called we know that only | |
1030 | * one CPU is up, so disabling interrupts is enough | |
1031 | * protection. This avoids the lockdep hell of lock ordering. | |
1032 | */ | |
1033 | local_irq_disable(); | |
1034 | ||
1035 | /* Remove the statically allocated objects from the pool */ | |
1036 | hlist_for_each_entry_safe(obj, node, tmp, &obj_pool, node) | |
1037 | hlist_del(&obj->node); | |
1038 | /* Move the allocated objects to the pool */ | |
1039 | hlist_move_list(&objects, &obj_pool); | |
1040 | ||
1041 | /* Replace the active object references */ | |
1042 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { | |
1043 | hlist_move_list(&db->list, &objects); | |
1044 | ||
1045 | hlist_for_each_entry(obj, node, &objects, node) { | |
1046 | new = hlist_entry(obj_pool.first, typeof(*obj), node); | |
1047 | hlist_del(&new->node); | |
1048 | /* copy object data */ | |
1049 | *new = *obj; | |
1050 | hlist_add_head(&new->node, &db->list); | |
1051 | cnt++; | |
1052 | } | |
1053 | } | |
765a5e0c | 1054 | local_irq_enable(); |
1be1cb7b TG |
1055 | |
1056 | printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt, | |
1057 | obj_pool_used); | |
1be1cb7b TG |
1058 | return 0; |
1059 | free: | |
1060 | hlist_for_each_entry_safe(obj, node, tmp, &objects, node) { | |
1061 | hlist_del(&obj->node); | |
1062 | kmem_cache_free(obj_cache, obj); | |
1063 | } | |
1064 | return -ENOMEM; | |
1065 | } | |
1066 | ||
3ac7fe5a TG |
1067 | /* |
1068 | * Called after the kmem_caches are functional to setup a dedicated | |
1069 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag | |
1070 | * prevents that the debug code is called on kmem_cache_free() for the | |
1071 | * debug tracker objects to avoid recursive calls. | |
1072 | */ | |
1073 | void __init debug_objects_mem_init(void) | |
1074 | { | |
1075 | if (!debug_objects_enabled) | |
1076 | return; | |
1077 | ||
1078 | obj_cache = kmem_cache_create("debug_objects_cache", | |
1079 | sizeof (struct debug_obj), 0, | |
1080 | SLAB_DEBUG_OBJECTS, NULL); | |
1081 | ||
1be1cb7b | 1082 | if (!obj_cache || debug_objects_replace_static_objects()) { |
3ac7fe5a | 1083 | debug_objects_enabled = 0; |
1be1cb7b TG |
1084 | if (obj_cache) |
1085 | kmem_cache_destroy(obj_cache); | |
1086 | printk(KERN_WARNING "ODEBUG: out of memory.\n"); | |
1087 | } else | |
3ac7fe5a TG |
1088 | debug_objects_selftest(); |
1089 | } |