Commit | Line | Data |
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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> | |
12 | #include <linux/seq_file.h> | |
13 | #include <linux/debugfs.h> | |
14 | #include <linux/hash.h> | |
15 | ||
16 | #define ODEBUG_HASH_BITS 14 | |
17 | #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) | |
18 | ||
19 | #define ODEBUG_POOL_SIZE 512 | |
20 | #define ODEBUG_POOL_MIN_LEVEL 256 | |
21 | ||
22 | #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT | |
23 | #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) | |
24 | #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) | |
25 | ||
26 | struct debug_bucket { | |
27 | struct hlist_head list; | |
28 | spinlock_t lock; | |
29 | }; | |
30 | ||
31 | static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; | |
32 | ||
33 | static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE]; | |
34 | ||
35 | static DEFINE_SPINLOCK(pool_lock); | |
36 | ||
37 | static HLIST_HEAD(obj_pool); | |
38 | ||
39 | static int obj_pool_min_free = ODEBUG_POOL_SIZE; | |
40 | static int obj_pool_free = ODEBUG_POOL_SIZE; | |
41 | static int obj_pool_used; | |
42 | static int obj_pool_max_used; | |
43 | static struct kmem_cache *obj_cache; | |
44 | ||
45 | static int debug_objects_maxchain __read_mostly; | |
46 | static int debug_objects_fixups __read_mostly; | |
47 | static int debug_objects_warnings __read_mostly; | |
3ae70205 IM |
48 | static int debug_objects_enabled __read_mostly |
49 | = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; | |
50 | ||
3ac7fe5a TG |
51 | static struct debug_obj_descr *descr_test __read_mostly; |
52 | ||
53 | static int __init enable_object_debug(char *str) | |
54 | { | |
55 | debug_objects_enabled = 1; | |
56 | return 0; | |
57 | } | |
3e8ebb5c KM |
58 | |
59 | static int __init disable_object_debug(char *str) | |
60 | { | |
61 | debug_objects_enabled = 0; | |
62 | return 0; | |
63 | } | |
64 | ||
3ac7fe5a | 65 | early_param("debug_objects", enable_object_debug); |
3e8ebb5c | 66 | early_param("no_debug_objects", disable_object_debug); |
3ac7fe5a TG |
67 | |
68 | static const char *obj_states[ODEBUG_STATE_MAX] = { | |
69 | [ODEBUG_STATE_NONE] = "none", | |
70 | [ODEBUG_STATE_INIT] = "initialized", | |
71 | [ODEBUG_STATE_INACTIVE] = "inactive", | |
72 | [ODEBUG_STATE_ACTIVE] = "active", | |
73 | [ODEBUG_STATE_DESTROYED] = "destroyed", | |
74 | [ODEBUG_STATE_NOTAVAILABLE] = "not available", | |
75 | }; | |
76 | ||
77 | static int fill_pool(void) | |
78 | { | |
79 | gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; | |
80 | struct debug_obj *new; | |
50db04dd | 81 | unsigned long flags; |
3ac7fe5a TG |
82 | |
83 | if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL)) | |
84 | return obj_pool_free; | |
85 | ||
86 | if (unlikely(!obj_cache)) | |
87 | return obj_pool_free; | |
88 | ||
89 | while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) { | |
90 | ||
91 | new = kmem_cache_zalloc(obj_cache, gfp); | |
92 | if (!new) | |
93 | return obj_pool_free; | |
94 | ||
50db04dd | 95 | spin_lock_irqsave(&pool_lock, flags); |
3ac7fe5a TG |
96 | hlist_add_head(&new->node, &obj_pool); |
97 | obj_pool_free++; | |
50db04dd | 98 | spin_unlock_irqrestore(&pool_lock, flags); |
3ac7fe5a TG |
99 | } |
100 | return obj_pool_free; | |
101 | } | |
102 | ||
103 | /* | |
104 | * Lookup an object in the hash bucket. | |
105 | */ | |
106 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) | |
107 | { | |
108 | struct hlist_node *node; | |
109 | struct debug_obj *obj; | |
110 | int cnt = 0; | |
111 | ||
112 | hlist_for_each_entry(obj, node, &b->list, node) { | |
113 | cnt++; | |
114 | if (obj->object == addr) | |
115 | return obj; | |
116 | } | |
117 | if (cnt > debug_objects_maxchain) | |
118 | debug_objects_maxchain = cnt; | |
119 | ||
120 | return NULL; | |
121 | } | |
122 | ||
123 | /* | |
50db04dd | 124 | * Allocate a new object. If the pool is empty, switch off the debugger. |
673d62cc | 125 | * Must be called with interrupts disabled. |
3ac7fe5a TG |
126 | */ |
127 | static struct debug_obj * | |
128 | alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) | |
129 | { | |
130 | struct debug_obj *obj = NULL; | |
3ac7fe5a | 131 | |
3ac7fe5a TG |
132 | spin_lock(&pool_lock); |
133 | if (obj_pool.first) { | |
134 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); | |
135 | ||
136 | obj->object = addr; | |
137 | obj->descr = descr; | |
138 | obj->state = ODEBUG_STATE_NONE; | |
139 | hlist_del(&obj->node); | |
140 | ||
141 | hlist_add_head(&obj->node, &b->list); | |
142 | ||
143 | obj_pool_used++; | |
144 | if (obj_pool_used > obj_pool_max_used) | |
145 | obj_pool_max_used = obj_pool_used; | |
146 | ||
147 | obj_pool_free--; | |
148 | if (obj_pool_free < obj_pool_min_free) | |
149 | obj_pool_min_free = obj_pool_free; | |
150 | } | |
151 | spin_unlock(&pool_lock); | |
152 | ||
3ac7fe5a TG |
153 | return obj; |
154 | } | |
155 | ||
156 | /* | |
157 | * Put the object back into the pool or give it back to kmem_cache: | |
158 | */ | |
159 | static void free_object(struct debug_obj *obj) | |
160 | { | |
161 | unsigned long idx = (unsigned long)(obj - obj_static_pool); | |
673d62cc | 162 | unsigned long flags; |
3ac7fe5a TG |
163 | |
164 | if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) { | |
673d62cc | 165 | spin_lock_irqsave(&pool_lock, flags); |
3ac7fe5a TG |
166 | hlist_add_head(&obj->node, &obj_pool); |
167 | obj_pool_free++; | |
168 | obj_pool_used--; | |
673d62cc | 169 | spin_unlock_irqrestore(&pool_lock, flags); |
3ac7fe5a | 170 | } else { |
673d62cc | 171 | spin_lock_irqsave(&pool_lock, flags); |
3ac7fe5a | 172 | obj_pool_used--; |
673d62cc | 173 | spin_unlock_irqrestore(&pool_lock, flags); |
3ac7fe5a TG |
174 | kmem_cache_free(obj_cache, obj); |
175 | } | |
176 | } | |
177 | ||
178 | /* | |
179 | * We run out of memory. That means we probably have tons of objects | |
180 | * allocated. | |
181 | */ | |
182 | static void debug_objects_oom(void) | |
183 | { | |
184 | struct debug_bucket *db = obj_hash; | |
185 | struct hlist_node *node, *tmp; | |
673d62cc | 186 | HLIST_HEAD(freelist); |
3ac7fe5a TG |
187 | struct debug_obj *obj; |
188 | unsigned long flags; | |
189 | int i; | |
190 | ||
191 | printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n"); | |
192 | ||
193 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { | |
194 | spin_lock_irqsave(&db->lock, flags); | |
673d62cc VN |
195 | hlist_move_list(&db->list, &freelist); |
196 | spin_unlock_irqrestore(&db->lock, flags); | |
197 | ||
198 | /* Now free them */ | |
199 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { | |
3ac7fe5a TG |
200 | hlist_del(&obj->node); |
201 | free_object(obj); | |
202 | } | |
3ac7fe5a TG |
203 | } |
204 | } | |
205 | ||
206 | /* | |
207 | * We use the pfn of the address for the hash. That way we can check | |
208 | * for freed objects simply by checking the affected bucket. | |
209 | */ | |
210 | static struct debug_bucket *get_bucket(unsigned long addr) | |
211 | { | |
212 | unsigned long hash; | |
213 | ||
214 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); | |
215 | return &obj_hash[hash]; | |
216 | } | |
217 | ||
218 | static void debug_print_object(struct debug_obj *obj, char *msg) | |
219 | { | |
220 | static int limit; | |
221 | ||
222 | if (limit < 5 && obj->descr != descr_test) { | |
223 | limit++; | |
5cd2b459 | 224 | WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, |
3ac7fe5a | 225 | obj_states[obj->state], obj->descr->name); |
3ac7fe5a TG |
226 | } |
227 | debug_objects_warnings++; | |
228 | } | |
229 | ||
230 | /* | |
231 | * Try to repair the damage, so we have a better chance to get useful | |
232 | * debug output. | |
233 | */ | |
234 | static void | |
235 | debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), | |
236 | void * addr, enum debug_obj_state state) | |
237 | { | |
238 | if (fixup) | |
239 | debug_objects_fixups += fixup(addr, state); | |
240 | } | |
241 | ||
242 | static void debug_object_is_on_stack(void *addr, int onstack) | |
243 | { | |
3ac7fe5a TG |
244 | int is_on_stack; |
245 | static int limit; | |
246 | ||
247 | if (limit > 4) | |
248 | return; | |
249 | ||
8b05c7e6 | 250 | is_on_stack = object_is_on_stack(addr); |
3ac7fe5a TG |
251 | if (is_on_stack == onstack) |
252 | return; | |
253 | ||
254 | limit++; | |
255 | if (is_on_stack) | |
256 | printk(KERN_WARNING | |
257 | "ODEBUG: object is on stack, but not annotated\n"); | |
258 | else | |
259 | printk(KERN_WARNING | |
260 | "ODEBUG: object is not on stack, but annotated\n"); | |
261 | WARN_ON(1); | |
262 | } | |
263 | ||
264 | static void | |
265 | __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) | |
266 | { | |
267 | enum debug_obj_state state; | |
268 | struct debug_bucket *db; | |
269 | struct debug_obj *obj; | |
270 | unsigned long flags; | |
271 | ||
50db04dd VN |
272 | fill_pool(); |
273 | ||
3ac7fe5a TG |
274 | db = get_bucket((unsigned long) addr); |
275 | ||
276 | spin_lock_irqsave(&db->lock, flags); | |
277 | ||
278 | obj = lookup_object(addr, db); | |
279 | if (!obj) { | |
280 | obj = alloc_object(addr, db, descr); | |
281 | if (!obj) { | |
282 | debug_objects_enabled = 0; | |
283 | spin_unlock_irqrestore(&db->lock, flags); | |
284 | debug_objects_oom(); | |
285 | return; | |
286 | } | |
287 | debug_object_is_on_stack(addr, onstack); | |
288 | } | |
289 | ||
290 | switch (obj->state) { | |
291 | case ODEBUG_STATE_NONE: | |
292 | case ODEBUG_STATE_INIT: | |
293 | case ODEBUG_STATE_INACTIVE: | |
294 | obj->state = ODEBUG_STATE_INIT; | |
295 | break; | |
296 | ||
297 | case ODEBUG_STATE_ACTIVE: | |
298 | debug_print_object(obj, "init"); | |
299 | state = obj->state; | |
300 | spin_unlock_irqrestore(&db->lock, flags); | |
301 | debug_object_fixup(descr->fixup_init, addr, state); | |
302 | return; | |
303 | ||
304 | case ODEBUG_STATE_DESTROYED: | |
305 | debug_print_object(obj, "init"); | |
306 | break; | |
307 | default: | |
308 | break; | |
309 | } | |
310 | ||
311 | spin_unlock_irqrestore(&db->lock, flags); | |
312 | } | |
313 | ||
314 | /** | |
315 | * debug_object_init - debug checks when an object is initialized | |
316 | * @addr: address of the object | |
317 | * @descr: pointer to an object specific debug description structure | |
318 | */ | |
319 | void debug_object_init(void *addr, struct debug_obj_descr *descr) | |
320 | { | |
321 | if (!debug_objects_enabled) | |
322 | return; | |
323 | ||
324 | __debug_object_init(addr, descr, 0); | |
325 | } | |
326 | ||
327 | /** | |
328 | * debug_object_init_on_stack - debug checks when an object on stack is | |
329 | * initialized | |
330 | * @addr: address of the object | |
331 | * @descr: pointer to an object specific debug description structure | |
332 | */ | |
333 | void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) | |
334 | { | |
335 | if (!debug_objects_enabled) | |
336 | return; | |
337 | ||
338 | __debug_object_init(addr, descr, 1); | |
339 | } | |
340 | ||
341 | /** | |
342 | * debug_object_activate - debug checks when an object is activated | |
343 | * @addr: address of the object | |
344 | * @descr: pointer to an object specific debug description structure | |
345 | */ | |
346 | void debug_object_activate(void *addr, struct debug_obj_descr *descr) | |
347 | { | |
348 | enum debug_obj_state state; | |
349 | struct debug_bucket *db; | |
350 | struct debug_obj *obj; | |
351 | unsigned long flags; | |
352 | ||
353 | if (!debug_objects_enabled) | |
354 | return; | |
355 | ||
356 | db = get_bucket((unsigned long) addr); | |
357 | ||
358 | spin_lock_irqsave(&db->lock, flags); | |
359 | ||
360 | obj = lookup_object(addr, db); | |
361 | if (obj) { | |
362 | switch (obj->state) { | |
363 | case ODEBUG_STATE_INIT: | |
364 | case ODEBUG_STATE_INACTIVE: | |
365 | obj->state = ODEBUG_STATE_ACTIVE; | |
366 | break; | |
367 | ||
368 | case ODEBUG_STATE_ACTIVE: | |
369 | debug_print_object(obj, "activate"); | |
370 | state = obj->state; | |
371 | spin_unlock_irqrestore(&db->lock, flags); | |
372 | debug_object_fixup(descr->fixup_activate, addr, state); | |
373 | return; | |
374 | ||
375 | case ODEBUG_STATE_DESTROYED: | |
376 | debug_print_object(obj, "activate"); | |
377 | break; | |
378 | default: | |
379 | break; | |
380 | } | |
381 | spin_unlock_irqrestore(&db->lock, flags); | |
382 | return; | |
383 | } | |
384 | ||
385 | spin_unlock_irqrestore(&db->lock, flags); | |
386 | /* | |
387 | * This happens when a static object is activated. We | |
388 | * let the type specific code decide whether this is | |
389 | * true or not. | |
390 | */ | |
391 | debug_object_fixup(descr->fixup_activate, addr, | |
392 | ODEBUG_STATE_NOTAVAILABLE); | |
393 | } | |
394 | ||
395 | /** | |
396 | * debug_object_deactivate - debug checks when an object is deactivated | |
397 | * @addr: address of the object | |
398 | * @descr: pointer to an object specific debug description structure | |
399 | */ | |
400 | void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) | |
401 | { | |
402 | struct debug_bucket *db; | |
403 | struct debug_obj *obj; | |
404 | unsigned long flags; | |
405 | ||
406 | if (!debug_objects_enabled) | |
407 | return; | |
408 | ||
409 | db = get_bucket((unsigned long) addr); | |
410 | ||
411 | spin_lock_irqsave(&db->lock, flags); | |
412 | ||
413 | obj = lookup_object(addr, db); | |
414 | if (obj) { | |
415 | switch (obj->state) { | |
416 | case ODEBUG_STATE_INIT: | |
417 | case ODEBUG_STATE_INACTIVE: | |
418 | case ODEBUG_STATE_ACTIVE: | |
419 | obj->state = ODEBUG_STATE_INACTIVE; | |
420 | break; | |
421 | ||
422 | case ODEBUG_STATE_DESTROYED: | |
423 | debug_print_object(obj, "deactivate"); | |
424 | break; | |
425 | default: | |
426 | break; | |
427 | } | |
428 | } else { | |
429 | struct debug_obj o = { .object = addr, | |
430 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
431 | .descr = descr }; | |
432 | ||
433 | debug_print_object(&o, "deactivate"); | |
434 | } | |
435 | ||
436 | spin_unlock_irqrestore(&db->lock, flags); | |
437 | } | |
438 | ||
439 | /** | |
440 | * debug_object_destroy - debug checks when an object is destroyed | |
441 | * @addr: address of the object | |
442 | * @descr: pointer to an object specific debug description structure | |
443 | */ | |
444 | void debug_object_destroy(void *addr, struct debug_obj_descr *descr) | |
445 | { | |
446 | enum debug_obj_state state; | |
447 | struct debug_bucket *db; | |
448 | struct debug_obj *obj; | |
449 | unsigned long flags; | |
450 | ||
451 | if (!debug_objects_enabled) | |
452 | return; | |
453 | ||
454 | db = get_bucket((unsigned long) addr); | |
455 | ||
456 | spin_lock_irqsave(&db->lock, flags); | |
457 | ||
458 | obj = lookup_object(addr, db); | |
459 | if (!obj) | |
460 | goto out_unlock; | |
461 | ||
462 | switch (obj->state) { | |
463 | case ODEBUG_STATE_NONE: | |
464 | case ODEBUG_STATE_INIT: | |
465 | case ODEBUG_STATE_INACTIVE: | |
466 | obj->state = ODEBUG_STATE_DESTROYED; | |
467 | break; | |
468 | case ODEBUG_STATE_ACTIVE: | |
469 | debug_print_object(obj, "destroy"); | |
470 | state = obj->state; | |
471 | spin_unlock_irqrestore(&db->lock, flags); | |
472 | debug_object_fixup(descr->fixup_destroy, addr, state); | |
473 | return; | |
474 | ||
475 | case ODEBUG_STATE_DESTROYED: | |
476 | debug_print_object(obj, "destroy"); | |
477 | break; | |
478 | default: | |
479 | break; | |
480 | } | |
481 | out_unlock: | |
482 | spin_unlock_irqrestore(&db->lock, flags); | |
483 | } | |
484 | ||
485 | /** | |
486 | * debug_object_free - debug checks when an object is freed | |
487 | * @addr: address of the object | |
488 | * @descr: pointer to an object specific debug description structure | |
489 | */ | |
490 | void debug_object_free(void *addr, struct debug_obj_descr *descr) | |
491 | { | |
492 | enum debug_obj_state state; | |
493 | struct debug_bucket *db; | |
494 | struct debug_obj *obj; | |
495 | unsigned long flags; | |
496 | ||
497 | if (!debug_objects_enabled) | |
498 | return; | |
499 | ||
500 | db = get_bucket((unsigned long) addr); | |
501 | ||
502 | spin_lock_irqsave(&db->lock, flags); | |
503 | ||
504 | obj = lookup_object(addr, db); | |
505 | if (!obj) | |
506 | goto out_unlock; | |
507 | ||
508 | switch (obj->state) { | |
509 | case ODEBUG_STATE_ACTIVE: | |
510 | debug_print_object(obj, "free"); | |
511 | state = obj->state; | |
512 | spin_unlock_irqrestore(&db->lock, flags); | |
513 | debug_object_fixup(descr->fixup_free, addr, state); | |
514 | return; | |
515 | default: | |
516 | hlist_del(&obj->node); | |
673d62cc | 517 | spin_unlock_irqrestore(&db->lock, flags); |
3ac7fe5a | 518 | free_object(obj); |
673d62cc | 519 | return; |
3ac7fe5a TG |
520 | } |
521 | out_unlock: | |
522 | spin_unlock_irqrestore(&db->lock, flags); | |
523 | } | |
524 | ||
525 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
526 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) | |
527 | { | |
528 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; | |
529 | struct hlist_node *node, *tmp; | |
673d62cc | 530 | HLIST_HEAD(freelist); |
3ac7fe5a TG |
531 | struct debug_obj_descr *descr; |
532 | enum debug_obj_state state; | |
533 | struct debug_bucket *db; | |
534 | struct debug_obj *obj; | |
535 | int cnt; | |
536 | ||
537 | saddr = (unsigned long) address; | |
538 | eaddr = saddr + size; | |
539 | paddr = saddr & ODEBUG_CHUNK_MASK; | |
540 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); | |
541 | chunks >>= ODEBUG_CHUNK_SHIFT; | |
542 | ||
543 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { | |
544 | db = get_bucket(paddr); | |
545 | ||
546 | repeat: | |
547 | cnt = 0; | |
548 | spin_lock_irqsave(&db->lock, flags); | |
549 | hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { | |
550 | cnt++; | |
551 | oaddr = (unsigned long) obj->object; | |
552 | if (oaddr < saddr || oaddr >= eaddr) | |
553 | continue; | |
554 | ||
555 | switch (obj->state) { | |
556 | case ODEBUG_STATE_ACTIVE: | |
557 | debug_print_object(obj, "free"); | |
558 | descr = obj->descr; | |
559 | state = obj->state; | |
560 | spin_unlock_irqrestore(&db->lock, flags); | |
561 | debug_object_fixup(descr->fixup_free, | |
562 | (void *) oaddr, state); | |
563 | goto repeat; | |
564 | default: | |
565 | hlist_del(&obj->node); | |
673d62cc | 566 | hlist_add_head(&obj->node, &freelist); |
3ac7fe5a TG |
567 | break; |
568 | } | |
569 | } | |
570 | spin_unlock_irqrestore(&db->lock, flags); | |
673d62cc VN |
571 | |
572 | /* Now free them */ | |
573 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { | |
574 | hlist_del(&obj->node); | |
575 | free_object(obj); | |
576 | } | |
577 | ||
3ac7fe5a TG |
578 | if (cnt > debug_objects_maxchain) |
579 | debug_objects_maxchain = cnt; | |
580 | } | |
581 | } | |
582 | ||
583 | void debug_check_no_obj_freed(const void *address, unsigned long size) | |
584 | { | |
585 | if (debug_objects_enabled) | |
586 | __debug_check_no_obj_freed(address, size); | |
587 | } | |
588 | #endif | |
589 | ||
590 | #ifdef CONFIG_DEBUG_FS | |
591 | ||
592 | static int debug_stats_show(struct seq_file *m, void *v) | |
593 | { | |
594 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); | |
595 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); | |
596 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); | |
597 | seq_printf(m, "pool_free :%d\n", obj_pool_free); | |
598 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); | |
599 | seq_printf(m, "pool_used :%d\n", obj_pool_used); | |
600 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); | |
601 | return 0; | |
602 | } | |
603 | ||
604 | static int debug_stats_open(struct inode *inode, struct file *filp) | |
605 | { | |
606 | return single_open(filp, debug_stats_show, NULL); | |
607 | } | |
608 | ||
609 | static const struct file_operations debug_stats_fops = { | |
610 | .open = debug_stats_open, | |
611 | .read = seq_read, | |
612 | .llseek = seq_lseek, | |
613 | .release = single_release, | |
614 | }; | |
615 | ||
616 | static int __init debug_objects_init_debugfs(void) | |
617 | { | |
618 | struct dentry *dbgdir, *dbgstats; | |
619 | ||
620 | if (!debug_objects_enabled) | |
621 | return 0; | |
622 | ||
623 | dbgdir = debugfs_create_dir("debug_objects", NULL); | |
624 | if (!dbgdir) | |
625 | return -ENOMEM; | |
626 | ||
627 | dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, | |
628 | &debug_stats_fops); | |
629 | if (!dbgstats) | |
630 | goto err; | |
631 | ||
632 | return 0; | |
633 | ||
634 | err: | |
635 | debugfs_remove(dbgdir); | |
636 | ||
637 | return -ENOMEM; | |
638 | } | |
639 | __initcall(debug_objects_init_debugfs); | |
640 | ||
641 | #else | |
642 | static inline void debug_objects_init_debugfs(void) { } | |
643 | #endif | |
644 | ||
645 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST | |
646 | ||
647 | /* Random data structure for the self test */ | |
648 | struct self_test { | |
649 | unsigned long dummy1[6]; | |
650 | int static_init; | |
651 | unsigned long dummy2[3]; | |
652 | }; | |
653 | ||
654 | static __initdata struct debug_obj_descr descr_type_test; | |
655 | ||
656 | /* | |
657 | * fixup_init is called when: | |
658 | * - an active object is initialized | |
659 | */ | |
660 | static int __init fixup_init(void *addr, enum debug_obj_state state) | |
661 | { | |
662 | struct self_test *obj = addr; | |
663 | ||
664 | switch (state) { | |
665 | case ODEBUG_STATE_ACTIVE: | |
666 | debug_object_deactivate(obj, &descr_type_test); | |
667 | debug_object_init(obj, &descr_type_test); | |
668 | return 1; | |
669 | default: | |
670 | return 0; | |
671 | } | |
672 | } | |
673 | ||
674 | /* | |
675 | * fixup_activate is called when: | |
676 | * - an active object is activated | |
677 | * - an unknown object is activated (might be a statically initialized object) | |
678 | */ | |
679 | static int __init fixup_activate(void *addr, enum debug_obj_state state) | |
680 | { | |
681 | struct self_test *obj = addr; | |
682 | ||
683 | switch (state) { | |
684 | case ODEBUG_STATE_NOTAVAILABLE: | |
685 | if (obj->static_init == 1) { | |
686 | debug_object_init(obj, &descr_type_test); | |
687 | debug_object_activate(obj, &descr_type_test); | |
688 | /* | |
689 | * Real code should return 0 here ! This is | |
690 | * not a fixup of some bad behaviour. We | |
691 | * merily call the debug_init function to keep | |
692 | * track of the object. | |
693 | */ | |
694 | return 1; | |
695 | } else { | |
696 | /* Real code needs to emit a warning here */ | |
697 | } | |
698 | return 0; | |
699 | ||
700 | case ODEBUG_STATE_ACTIVE: | |
701 | debug_object_deactivate(obj, &descr_type_test); | |
702 | debug_object_activate(obj, &descr_type_test); | |
703 | return 1; | |
704 | ||
705 | default: | |
706 | return 0; | |
707 | } | |
708 | } | |
709 | ||
710 | /* | |
711 | * fixup_destroy is called when: | |
712 | * - an active object is destroyed | |
713 | */ | |
714 | static int __init fixup_destroy(void *addr, enum debug_obj_state state) | |
715 | { | |
716 | struct self_test *obj = addr; | |
717 | ||
718 | switch (state) { | |
719 | case ODEBUG_STATE_ACTIVE: | |
720 | debug_object_deactivate(obj, &descr_type_test); | |
721 | debug_object_destroy(obj, &descr_type_test); | |
722 | return 1; | |
723 | default: | |
724 | return 0; | |
725 | } | |
726 | } | |
727 | ||
728 | /* | |
729 | * fixup_free is called when: | |
730 | * - an active object is freed | |
731 | */ | |
732 | static int __init fixup_free(void *addr, enum debug_obj_state state) | |
733 | { | |
734 | struct self_test *obj = addr; | |
735 | ||
736 | switch (state) { | |
737 | case ODEBUG_STATE_ACTIVE: | |
738 | debug_object_deactivate(obj, &descr_type_test); | |
739 | debug_object_free(obj, &descr_type_test); | |
740 | return 1; | |
741 | default: | |
742 | return 0; | |
743 | } | |
744 | } | |
745 | ||
746 | static int | |
747 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) | |
748 | { | |
749 | struct debug_bucket *db; | |
750 | struct debug_obj *obj; | |
751 | unsigned long flags; | |
752 | int res = -EINVAL; | |
753 | ||
754 | db = get_bucket((unsigned long) addr); | |
755 | ||
756 | spin_lock_irqsave(&db->lock, flags); | |
757 | ||
758 | obj = lookup_object(addr, db); | |
759 | if (!obj && state != ODEBUG_STATE_NONE) { | |
5cd2b459 | 760 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); |
3ac7fe5a TG |
761 | goto out; |
762 | } | |
763 | if (obj && obj->state != state) { | |
5cd2b459 | 764 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", |
3ac7fe5a | 765 | obj->state, state); |
3ac7fe5a TG |
766 | goto out; |
767 | } | |
768 | if (fixups != debug_objects_fixups) { | |
5cd2b459 | 769 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", |
3ac7fe5a | 770 | fixups, debug_objects_fixups); |
3ac7fe5a TG |
771 | goto out; |
772 | } | |
773 | if (warnings != debug_objects_warnings) { | |
5cd2b459 | 774 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", |
3ac7fe5a | 775 | warnings, debug_objects_warnings); |
3ac7fe5a TG |
776 | goto out; |
777 | } | |
778 | res = 0; | |
779 | out: | |
780 | spin_unlock_irqrestore(&db->lock, flags); | |
781 | if (res) | |
782 | debug_objects_enabled = 0; | |
783 | return res; | |
784 | } | |
785 | ||
786 | static __initdata struct debug_obj_descr descr_type_test = { | |
787 | .name = "selftest", | |
788 | .fixup_init = fixup_init, | |
789 | .fixup_activate = fixup_activate, | |
790 | .fixup_destroy = fixup_destroy, | |
791 | .fixup_free = fixup_free, | |
792 | }; | |
793 | ||
794 | static __initdata struct self_test obj = { .static_init = 0 }; | |
795 | ||
796 | static void __init debug_objects_selftest(void) | |
797 | { | |
798 | int fixups, oldfixups, warnings, oldwarnings; | |
799 | unsigned long flags; | |
800 | ||
801 | local_irq_save(flags); | |
802 | ||
803 | fixups = oldfixups = debug_objects_fixups; | |
804 | warnings = oldwarnings = debug_objects_warnings; | |
805 | descr_test = &descr_type_test; | |
806 | ||
807 | debug_object_init(&obj, &descr_type_test); | |
808 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
809 | goto out; | |
810 | debug_object_activate(&obj, &descr_type_test); | |
811 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
812 | goto out; | |
813 | debug_object_activate(&obj, &descr_type_test); | |
814 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) | |
815 | goto out; | |
816 | debug_object_deactivate(&obj, &descr_type_test); | |
817 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) | |
818 | goto out; | |
819 | debug_object_destroy(&obj, &descr_type_test); | |
820 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) | |
821 | goto out; | |
822 | debug_object_init(&obj, &descr_type_test); | |
823 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
824 | goto out; | |
825 | debug_object_activate(&obj, &descr_type_test); | |
826 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
827 | goto out; | |
828 | debug_object_deactivate(&obj, &descr_type_test); | |
829 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
830 | goto out; | |
831 | debug_object_free(&obj, &descr_type_test); | |
832 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
833 | goto out; | |
834 | ||
835 | obj.static_init = 1; | |
836 | debug_object_activate(&obj, &descr_type_test); | |
837 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings)) | |
838 | goto out; | |
839 | debug_object_init(&obj, &descr_type_test); | |
840 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) | |
841 | goto out; | |
842 | debug_object_free(&obj, &descr_type_test); | |
843 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
844 | goto out; | |
845 | ||
846 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
847 | debug_object_init(&obj, &descr_type_test); | |
848 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
849 | goto out; | |
850 | debug_object_activate(&obj, &descr_type_test); | |
851 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
852 | goto out; | |
853 | __debug_check_no_obj_freed(&obj, sizeof(obj)); | |
854 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) | |
855 | goto out; | |
856 | #endif | |
857 | printk(KERN_INFO "ODEBUG: selftest passed\n"); | |
858 | ||
859 | out: | |
860 | debug_objects_fixups = oldfixups; | |
861 | debug_objects_warnings = oldwarnings; | |
862 | descr_test = NULL; | |
863 | ||
864 | local_irq_restore(flags); | |
865 | } | |
866 | #else | |
867 | static inline void debug_objects_selftest(void) { } | |
868 | #endif | |
869 | ||
870 | /* | |
871 | * Called during early boot to initialize the hash buckets and link | |
872 | * the static object pool objects into the poll list. After this call | |
873 | * the object tracker is fully operational. | |
874 | */ | |
875 | void __init debug_objects_early_init(void) | |
876 | { | |
877 | int i; | |
878 | ||
879 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) | |
880 | spin_lock_init(&obj_hash[i].lock); | |
881 | ||
882 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) | |
883 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); | |
884 | } | |
885 | ||
886 | /* | |
887 | * Called after the kmem_caches are functional to setup a dedicated | |
888 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag | |
889 | * prevents that the debug code is called on kmem_cache_free() for the | |
890 | * debug tracker objects to avoid recursive calls. | |
891 | */ | |
892 | void __init debug_objects_mem_init(void) | |
893 | { | |
894 | if (!debug_objects_enabled) | |
895 | return; | |
896 | ||
897 | obj_cache = kmem_cache_create("debug_objects_cache", | |
898 | sizeof (struct debug_obj), 0, | |
899 | SLAB_DEBUG_OBJECTS, NULL); | |
900 | ||
901 | if (!obj_cache) | |
902 | debug_objects_enabled = 0; | |
903 | else | |
904 | debug_objects_selftest(); | |
905 | } |