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