Root/
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/sched.h> |
13 | #include <linux/seq_file.h> |
14 | #include <linux/debugfs.h> |
15 | #include <linux/slab.h> |
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; |
30 | raw_spinlock_t lock; |
31 | }; |
32 | |
33 | static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; |
34 | |
35 | static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata; |
36 | |
37 | static DEFINE_RAW_SPINLOCK(pool_lock); |
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; |
50 | static int debug_objects_enabled __read_mostly |
51 | = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; |
52 | |
53 | static struct debug_obj_descr *descr_test __read_mostly; |
54 | |
55 | static void free_obj_work(struct work_struct *work); |
56 | static DECLARE_WORK(debug_obj_work, free_obj_work); |
57 | |
58 | static int __init enable_object_debug(char *str) |
59 | { |
60 | debug_objects_enabled = 1; |
61 | return 0; |
62 | } |
63 | |
64 | static int __init disable_object_debug(char *str) |
65 | { |
66 | debug_objects_enabled = 0; |
67 | return 0; |
68 | } |
69 | |
70 | early_param("debug_objects", enable_object_debug); |
71 | early_param("no_debug_objects", disable_object_debug); |
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 | |
82 | static int fill_pool(void) |
83 | { |
84 | gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; |
85 | struct debug_obj *new; |
86 | unsigned long flags; |
87 | |
88 | if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL)) |
89 | return obj_pool_free; |
90 | |
91 | if (unlikely(!obj_cache)) |
92 | return obj_pool_free; |
93 | |
94 | while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) { |
95 | |
96 | new = kmem_cache_zalloc(obj_cache, gfp); |
97 | if (!new) |
98 | return obj_pool_free; |
99 | |
100 | raw_spin_lock_irqsave(&pool_lock, flags); |
101 | hlist_add_head(&new->node, &obj_pool); |
102 | obj_pool_free++; |
103 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
104 | } |
105 | return obj_pool_free; |
106 | } |
107 | |
108 | /* |
109 | * Lookup an object in the hash bucket. |
110 | */ |
111 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) |
112 | { |
113 | struct hlist_node *node; |
114 | struct debug_obj *obj; |
115 | int cnt = 0; |
116 | |
117 | hlist_for_each_entry(obj, node, &b->list, node) { |
118 | cnt++; |
119 | if (obj->object == addr) |
120 | return obj; |
121 | } |
122 | if (cnt > debug_objects_maxchain) |
123 | debug_objects_maxchain = cnt; |
124 | |
125 | return NULL; |
126 | } |
127 | |
128 | /* |
129 | * Allocate a new object. If the pool is empty, switch off the debugger. |
130 | * Must be called with interrupts disabled. |
131 | */ |
132 | static struct debug_obj * |
133 | alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) |
134 | { |
135 | struct debug_obj *obj = NULL; |
136 | |
137 | raw_spin_lock(&pool_lock); |
138 | if (obj_pool.first) { |
139 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); |
140 | |
141 | obj->object = addr; |
142 | obj->descr = descr; |
143 | obj->state = ODEBUG_STATE_NONE; |
144 | obj->astate = 0; |
145 | hlist_del(&obj->node); |
146 | |
147 | hlist_add_head(&obj->node, &b->list); |
148 | |
149 | obj_pool_used++; |
150 | if (obj_pool_used > obj_pool_max_used) |
151 | obj_pool_max_used = obj_pool_used; |
152 | |
153 | obj_pool_free--; |
154 | if (obj_pool_free < obj_pool_min_free) |
155 | obj_pool_min_free = obj_pool_free; |
156 | } |
157 | raw_spin_unlock(&pool_lock); |
158 | |
159 | return obj; |
160 | } |
161 | |
162 | /* |
163 | * workqueue function to free objects. |
164 | */ |
165 | static void free_obj_work(struct work_struct *work) |
166 | { |
167 | struct debug_obj *obj; |
168 | unsigned long flags; |
169 | |
170 | raw_spin_lock_irqsave(&pool_lock, flags); |
171 | while (obj_pool_free > ODEBUG_POOL_SIZE) { |
172 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); |
173 | hlist_del(&obj->node); |
174 | obj_pool_free--; |
175 | /* |
176 | * We release pool_lock across kmem_cache_free() to |
177 | * avoid contention on pool_lock. |
178 | */ |
179 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
180 | kmem_cache_free(obj_cache, obj); |
181 | raw_spin_lock_irqsave(&pool_lock, flags); |
182 | } |
183 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
184 | } |
185 | |
186 | /* |
187 | * Put the object back into the pool and schedule work to free objects |
188 | * if necessary. |
189 | */ |
190 | static void free_object(struct debug_obj *obj) |
191 | { |
192 | unsigned long flags; |
193 | int sched = 0; |
194 | |
195 | raw_spin_lock_irqsave(&pool_lock, flags); |
196 | /* |
197 | * schedule work when the pool is filled and the cache is |
198 | * initialized: |
199 | */ |
200 | if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache) |
201 | sched = !work_pending(&debug_obj_work); |
202 | hlist_add_head(&obj->node, &obj_pool); |
203 | obj_pool_free++; |
204 | obj_pool_used--; |
205 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
206 | if (sched) |
207 | schedule_work(&debug_obj_work); |
208 | } |
209 | |
210 | /* |
211 | * We run out of memory. That means we probably have tons of objects |
212 | * allocated. |
213 | */ |
214 | static void debug_objects_oom(void) |
215 | { |
216 | struct debug_bucket *db = obj_hash; |
217 | struct hlist_node *node, *tmp; |
218 | HLIST_HEAD(freelist); |
219 | struct debug_obj *obj; |
220 | unsigned long flags; |
221 | int i; |
222 | |
223 | printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n"); |
224 | |
225 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
226 | raw_spin_lock_irqsave(&db->lock, flags); |
227 | hlist_move_list(&db->list, &freelist); |
228 | raw_spin_unlock_irqrestore(&db->lock, flags); |
229 | |
230 | /* Now free them */ |
231 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { |
232 | hlist_del(&obj->node); |
233 | free_object(obj); |
234 | } |
235 | } |
236 | } |
237 | |
238 | /* |
239 | * We use the pfn of the address for the hash. That way we can check |
240 | * for freed objects simply by checking the affected bucket. |
241 | */ |
242 | static struct debug_bucket *get_bucket(unsigned long addr) |
243 | { |
244 | unsigned long hash; |
245 | |
246 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); |
247 | return &obj_hash[hash]; |
248 | } |
249 | |
250 | static void debug_print_object(struct debug_obj *obj, char *msg) |
251 | { |
252 | static int limit; |
253 | |
254 | if (limit < 5 && obj->descr != descr_test) { |
255 | limit++; |
256 | WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " |
257 | "object type: %s\n", |
258 | msg, obj_states[obj->state], obj->astate, |
259 | obj->descr->name); |
260 | } |
261 | debug_objects_warnings++; |
262 | } |
263 | |
264 | /* |
265 | * Try to repair the damage, so we have a better chance to get useful |
266 | * debug output. |
267 | */ |
268 | static void |
269 | debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), |
270 | void * addr, enum debug_obj_state state) |
271 | { |
272 | if (fixup) |
273 | debug_objects_fixups += fixup(addr, state); |
274 | } |
275 | |
276 | static void debug_object_is_on_stack(void *addr, int onstack) |
277 | { |
278 | int is_on_stack; |
279 | static int limit; |
280 | |
281 | if (limit > 4) |
282 | return; |
283 | |
284 | is_on_stack = object_is_on_stack(addr); |
285 | if (is_on_stack == onstack) |
286 | return; |
287 | |
288 | limit++; |
289 | if (is_on_stack) |
290 | printk(KERN_WARNING |
291 | "ODEBUG: object is on stack, but not annotated\n"); |
292 | else |
293 | printk(KERN_WARNING |
294 | "ODEBUG: object is not on stack, but annotated\n"); |
295 | WARN_ON(1); |
296 | } |
297 | |
298 | static void |
299 | __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) |
300 | { |
301 | enum debug_obj_state state; |
302 | struct debug_bucket *db; |
303 | struct debug_obj *obj; |
304 | unsigned long flags; |
305 | |
306 | fill_pool(); |
307 | |
308 | db = get_bucket((unsigned long) addr); |
309 | |
310 | raw_spin_lock_irqsave(&db->lock, flags); |
311 | |
312 | obj = lookup_object(addr, db); |
313 | if (!obj) { |
314 | obj = alloc_object(addr, db, descr); |
315 | if (!obj) { |
316 | debug_objects_enabled = 0; |
317 | raw_spin_unlock_irqrestore(&db->lock, flags); |
318 | debug_objects_oom(); |
319 | return; |
320 | } |
321 | debug_object_is_on_stack(addr, onstack); |
322 | } |
323 | |
324 | switch (obj->state) { |
325 | case ODEBUG_STATE_NONE: |
326 | case ODEBUG_STATE_INIT: |
327 | case ODEBUG_STATE_INACTIVE: |
328 | obj->state = ODEBUG_STATE_INIT; |
329 | break; |
330 | |
331 | case ODEBUG_STATE_ACTIVE: |
332 | debug_print_object(obj, "init"); |
333 | state = obj->state; |
334 | raw_spin_unlock_irqrestore(&db->lock, flags); |
335 | debug_object_fixup(descr->fixup_init, addr, state); |
336 | return; |
337 | |
338 | case ODEBUG_STATE_DESTROYED: |
339 | debug_print_object(obj, "init"); |
340 | break; |
341 | default: |
342 | break; |
343 | } |
344 | |
345 | raw_spin_unlock_irqrestore(&db->lock, flags); |
346 | } |
347 | |
348 | /** |
349 | * debug_object_init - debug checks when an object is initialized |
350 | * @addr: address of the object |
351 | * @descr: pointer to an object specific debug description structure |
352 | */ |
353 | void debug_object_init(void *addr, struct debug_obj_descr *descr) |
354 | { |
355 | if (!debug_objects_enabled) |
356 | return; |
357 | |
358 | __debug_object_init(addr, descr, 0); |
359 | } |
360 | |
361 | /** |
362 | * debug_object_init_on_stack - debug checks when an object on stack is |
363 | * initialized |
364 | * @addr: address of the object |
365 | * @descr: pointer to an object specific debug description structure |
366 | */ |
367 | void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) |
368 | { |
369 | if (!debug_objects_enabled) |
370 | return; |
371 | |
372 | __debug_object_init(addr, descr, 1); |
373 | } |
374 | |
375 | /** |
376 | * debug_object_activate - debug checks when an object is activated |
377 | * @addr: address of the object |
378 | * @descr: pointer to an object specific debug description structure |
379 | */ |
380 | void debug_object_activate(void *addr, struct debug_obj_descr *descr) |
381 | { |
382 | enum debug_obj_state state; |
383 | struct debug_bucket *db; |
384 | struct debug_obj *obj; |
385 | unsigned long flags; |
386 | |
387 | if (!debug_objects_enabled) |
388 | return; |
389 | |
390 | db = get_bucket((unsigned long) addr); |
391 | |
392 | raw_spin_lock_irqsave(&db->lock, flags); |
393 | |
394 | obj = lookup_object(addr, db); |
395 | if (obj) { |
396 | switch (obj->state) { |
397 | case ODEBUG_STATE_INIT: |
398 | case ODEBUG_STATE_INACTIVE: |
399 | obj->state = ODEBUG_STATE_ACTIVE; |
400 | break; |
401 | |
402 | case ODEBUG_STATE_ACTIVE: |
403 | debug_print_object(obj, "activate"); |
404 | state = obj->state; |
405 | raw_spin_unlock_irqrestore(&db->lock, flags); |
406 | debug_object_fixup(descr->fixup_activate, addr, state); |
407 | return; |
408 | |
409 | case ODEBUG_STATE_DESTROYED: |
410 | debug_print_object(obj, "activate"); |
411 | break; |
412 | default: |
413 | break; |
414 | } |
415 | raw_spin_unlock_irqrestore(&db->lock, flags); |
416 | return; |
417 | } |
418 | |
419 | raw_spin_unlock_irqrestore(&db->lock, flags); |
420 | /* |
421 | * This happens when a static object is activated. We |
422 | * let the type specific code decide whether this is |
423 | * true or not. |
424 | */ |
425 | debug_object_fixup(descr->fixup_activate, addr, |
426 | ODEBUG_STATE_NOTAVAILABLE); |
427 | } |
428 | |
429 | /** |
430 | * debug_object_deactivate - debug checks when an object is deactivated |
431 | * @addr: address of the object |
432 | * @descr: pointer to an object specific debug description structure |
433 | */ |
434 | void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) |
435 | { |
436 | struct debug_bucket *db; |
437 | struct debug_obj *obj; |
438 | unsigned long flags; |
439 | |
440 | if (!debug_objects_enabled) |
441 | return; |
442 | |
443 | db = get_bucket((unsigned long) addr); |
444 | |
445 | raw_spin_lock_irqsave(&db->lock, flags); |
446 | |
447 | obj = lookup_object(addr, db); |
448 | if (obj) { |
449 | switch (obj->state) { |
450 | case ODEBUG_STATE_INIT: |
451 | case ODEBUG_STATE_INACTIVE: |
452 | case ODEBUG_STATE_ACTIVE: |
453 | if (!obj->astate) |
454 | obj->state = ODEBUG_STATE_INACTIVE; |
455 | else |
456 | debug_print_object(obj, "deactivate"); |
457 | break; |
458 | |
459 | case ODEBUG_STATE_DESTROYED: |
460 | debug_print_object(obj, "deactivate"); |
461 | break; |
462 | default: |
463 | break; |
464 | } |
465 | } else { |
466 | struct debug_obj o = { .object = addr, |
467 | .state = ODEBUG_STATE_NOTAVAILABLE, |
468 | .descr = descr }; |
469 | |
470 | debug_print_object(&o, "deactivate"); |
471 | } |
472 | |
473 | raw_spin_unlock_irqrestore(&db->lock, flags); |
474 | } |
475 | |
476 | /** |
477 | * debug_object_destroy - debug checks when an object is destroyed |
478 | * @addr: address of the object |
479 | * @descr: pointer to an object specific debug description structure |
480 | */ |
481 | void debug_object_destroy(void *addr, struct debug_obj_descr *descr) |
482 | { |
483 | enum debug_obj_state state; |
484 | struct debug_bucket *db; |
485 | struct debug_obj *obj; |
486 | unsigned long flags; |
487 | |
488 | if (!debug_objects_enabled) |
489 | return; |
490 | |
491 | db = get_bucket((unsigned long) addr); |
492 | |
493 | raw_spin_lock_irqsave(&db->lock, flags); |
494 | |
495 | obj = lookup_object(addr, db); |
496 | if (!obj) |
497 | goto out_unlock; |
498 | |
499 | switch (obj->state) { |
500 | case ODEBUG_STATE_NONE: |
501 | case ODEBUG_STATE_INIT: |
502 | case ODEBUG_STATE_INACTIVE: |
503 | obj->state = ODEBUG_STATE_DESTROYED; |
504 | break; |
505 | case ODEBUG_STATE_ACTIVE: |
506 | debug_print_object(obj, "destroy"); |
507 | state = obj->state; |
508 | raw_spin_unlock_irqrestore(&db->lock, flags); |
509 | debug_object_fixup(descr->fixup_destroy, addr, state); |
510 | return; |
511 | |
512 | case ODEBUG_STATE_DESTROYED: |
513 | debug_print_object(obj, "destroy"); |
514 | break; |
515 | default: |
516 | break; |
517 | } |
518 | out_unlock: |
519 | raw_spin_unlock_irqrestore(&db->lock, flags); |
520 | } |
521 | |
522 | /** |
523 | * debug_object_free - debug checks when an object is freed |
524 | * @addr: address of the object |
525 | * @descr: pointer to an object specific debug description structure |
526 | */ |
527 | void debug_object_free(void *addr, struct debug_obj_descr *descr) |
528 | { |
529 | enum debug_obj_state state; |
530 | struct debug_bucket *db; |
531 | struct debug_obj *obj; |
532 | unsigned long flags; |
533 | |
534 | if (!debug_objects_enabled) |
535 | return; |
536 | |
537 | db = get_bucket((unsigned long) addr); |
538 | |
539 | raw_spin_lock_irqsave(&db->lock, flags); |
540 | |
541 | obj = lookup_object(addr, db); |
542 | if (!obj) |
543 | goto out_unlock; |
544 | |
545 | switch (obj->state) { |
546 | case ODEBUG_STATE_ACTIVE: |
547 | debug_print_object(obj, "free"); |
548 | state = obj->state; |
549 | raw_spin_unlock_irqrestore(&db->lock, flags); |
550 | debug_object_fixup(descr->fixup_free, addr, state); |
551 | return; |
552 | default: |
553 | hlist_del(&obj->node); |
554 | raw_spin_unlock_irqrestore(&db->lock, flags); |
555 | free_object(obj); |
556 | return; |
557 | } |
558 | out_unlock: |
559 | raw_spin_unlock_irqrestore(&db->lock, flags); |
560 | } |
561 | |
562 | /** |
563 | * debug_object_active_state - debug checks object usage state machine |
564 | * @addr: address of the object |
565 | * @descr: pointer to an object specific debug description structure |
566 | * @expect: expected state |
567 | * @next: state to move to if expected state is found |
568 | */ |
569 | void |
570 | debug_object_active_state(void *addr, struct debug_obj_descr *descr, |
571 | unsigned int expect, unsigned int next) |
572 | { |
573 | struct debug_bucket *db; |
574 | struct debug_obj *obj; |
575 | unsigned long flags; |
576 | |
577 | if (!debug_objects_enabled) |
578 | return; |
579 | |
580 | db = get_bucket((unsigned long) addr); |
581 | |
582 | raw_spin_lock_irqsave(&db->lock, flags); |
583 | |
584 | obj = lookup_object(addr, db); |
585 | if (obj) { |
586 | switch (obj->state) { |
587 | case ODEBUG_STATE_ACTIVE: |
588 | if (obj->astate == expect) |
589 | obj->astate = next; |
590 | else |
591 | debug_print_object(obj, "active_state"); |
592 | break; |
593 | |
594 | default: |
595 | debug_print_object(obj, "active_state"); |
596 | break; |
597 | } |
598 | } else { |
599 | struct debug_obj o = { .object = addr, |
600 | .state = ODEBUG_STATE_NOTAVAILABLE, |
601 | .descr = descr }; |
602 | |
603 | debug_print_object(&o, "active_state"); |
604 | } |
605 | |
606 | raw_spin_unlock_irqrestore(&db->lock, flags); |
607 | } |
608 | |
609 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
610 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) |
611 | { |
612 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; |
613 | struct hlist_node *node, *tmp; |
614 | HLIST_HEAD(freelist); |
615 | struct debug_obj_descr *descr; |
616 | enum debug_obj_state state; |
617 | struct debug_bucket *db; |
618 | struct debug_obj *obj; |
619 | int cnt; |
620 | |
621 | saddr = (unsigned long) address; |
622 | eaddr = saddr + size; |
623 | paddr = saddr & ODEBUG_CHUNK_MASK; |
624 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); |
625 | chunks >>= ODEBUG_CHUNK_SHIFT; |
626 | |
627 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { |
628 | db = get_bucket(paddr); |
629 | |
630 | repeat: |
631 | cnt = 0; |
632 | raw_spin_lock_irqsave(&db->lock, flags); |
633 | hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { |
634 | cnt++; |
635 | oaddr = (unsigned long) obj->object; |
636 | if (oaddr < saddr || oaddr >= eaddr) |
637 | continue; |
638 | |
639 | switch (obj->state) { |
640 | case ODEBUG_STATE_ACTIVE: |
641 | debug_print_object(obj, "free"); |
642 | descr = obj->descr; |
643 | state = obj->state; |
644 | raw_spin_unlock_irqrestore(&db->lock, flags); |
645 | debug_object_fixup(descr->fixup_free, |
646 | (void *) oaddr, state); |
647 | goto repeat; |
648 | default: |
649 | hlist_del(&obj->node); |
650 | hlist_add_head(&obj->node, &freelist); |
651 | break; |
652 | } |
653 | } |
654 | raw_spin_unlock_irqrestore(&db->lock, flags); |
655 | |
656 | /* Now free them */ |
657 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { |
658 | hlist_del(&obj->node); |
659 | free_object(obj); |
660 | } |
661 | |
662 | if (cnt > debug_objects_maxchain) |
663 | debug_objects_maxchain = cnt; |
664 | } |
665 | } |
666 | |
667 | void debug_check_no_obj_freed(const void *address, unsigned long size) |
668 | { |
669 | if (debug_objects_enabled) |
670 | __debug_check_no_obj_freed(address, size); |
671 | } |
672 | #endif |
673 | |
674 | #ifdef CONFIG_DEBUG_FS |
675 | |
676 | static int debug_stats_show(struct seq_file *m, void *v) |
677 | { |
678 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); |
679 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); |
680 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); |
681 | seq_printf(m, "pool_free :%d\n", obj_pool_free); |
682 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); |
683 | seq_printf(m, "pool_used :%d\n", obj_pool_used); |
684 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); |
685 | return 0; |
686 | } |
687 | |
688 | static int debug_stats_open(struct inode *inode, struct file *filp) |
689 | { |
690 | return single_open(filp, debug_stats_show, NULL); |
691 | } |
692 | |
693 | static const struct file_operations debug_stats_fops = { |
694 | .open = debug_stats_open, |
695 | .read = seq_read, |
696 | .llseek = seq_lseek, |
697 | .release = single_release, |
698 | }; |
699 | |
700 | static int __init debug_objects_init_debugfs(void) |
701 | { |
702 | struct dentry *dbgdir, *dbgstats; |
703 | |
704 | if (!debug_objects_enabled) |
705 | return 0; |
706 | |
707 | dbgdir = debugfs_create_dir("debug_objects", NULL); |
708 | if (!dbgdir) |
709 | return -ENOMEM; |
710 | |
711 | dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, |
712 | &debug_stats_fops); |
713 | if (!dbgstats) |
714 | goto err; |
715 | |
716 | return 0; |
717 | |
718 | err: |
719 | debugfs_remove(dbgdir); |
720 | |
721 | return -ENOMEM; |
722 | } |
723 | __initcall(debug_objects_init_debugfs); |
724 | |
725 | #else |
726 | static inline void debug_objects_init_debugfs(void) { } |
727 | #endif |
728 | |
729 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST |
730 | |
731 | /* Random data structure for the self test */ |
732 | struct self_test { |
733 | unsigned long dummy1[6]; |
734 | int static_init; |
735 | unsigned long dummy2[3]; |
736 | }; |
737 | |
738 | static __initdata struct debug_obj_descr descr_type_test; |
739 | |
740 | /* |
741 | * fixup_init is called when: |
742 | * - an active object is initialized |
743 | */ |
744 | static int __init fixup_init(void *addr, enum debug_obj_state state) |
745 | { |
746 | struct self_test *obj = addr; |
747 | |
748 | switch (state) { |
749 | case ODEBUG_STATE_ACTIVE: |
750 | debug_object_deactivate(obj, &descr_type_test); |
751 | debug_object_init(obj, &descr_type_test); |
752 | return 1; |
753 | default: |
754 | return 0; |
755 | } |
756 | } |
757 | |
758 | /* |
759 | * fixup_activate is called when: |
760 | * - an active object is activated |
761 | * - an unknown object is activated (might be a statically initialized object) |
762 | */ |
763 | static int __init fixup_activate(void *addr, enum debug_obj_state state) |
764 | { |
765 | struct self_test *obj = addr; |
766 | |
767 | switch (state) { |
768 | case ODEBUG_STATE_NOTAVAILABLE: |
769 | if (obj->static_init == 1) { |
770 | debug_object_init(obj, &descr_type_test); |
771 | debug_object_activate(obj, &descr_type_test); |
772 | /* |
773 | * Real code should return 0 here ! This is |
774 | * not a fixup of some bad behaviour. We |
775 | * merily call the debug_init function to keep |
776 | * track of the object. |
777 | */ |
778 | return 1; |
779 | } else { |
780 | /* Real code needs to emit a warning here */ |
781 | } |
782 | return 0; |
783 | |
784 | case ODEBUG_STATE_ACTIVE: |
785 | debug_object_deactivate(obj, &descr_type_test); |
786 | debug_object_activate(obj, &descr_type_test); |
787 | return 1; |
788 | |
789 | default: |
790 | return 0; |
791 | } |
792 | } |
793 | |
794 | /* |
795 | * fixup_destroy is called when: |
796 | * - an active object is destroyed |
797 | */ |
798 | static int __init fixup_destroy(void *addr, enum debug_obj_state state) |
799 | { |
800 | struct self_test *obj = addr; |
801 | |
802 | switch (state) { |
803 | case ODEBUG_STATE_ACTIVE: |
804 | debug_object_deactivate(obj, &descr_type_test); |
805 | debug_object_destroy(obj, &descr_type_test); |
806 | return 1; |
807 | default: |
808 | return 0; |
809 | } |
810 | } |
811 | |
812 | /* |
813 | * fixup_free is called when: |
814 | * - an active object is freed |
815 | */ |
816 | static int __init fixup_free(void *addr, enum debug_obj_state state) |
817 | { |
818 | struct self_test *obj = addr; |
819 | |
820 | switch (state) { |
821 | case ODEBUG_STATE_ACTIVE: |
822 | debug_object_deactivate(obj, &descr_type_test); |
823 | debug_object_free(obj, &descr_type_test); |
824 | return 1; |
825 | default: |
826 | return 0; |
827 | } |
828 | } |
829 | |
830 | static int __init |
831 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) |
832 | { |
833 | struct debug_bucket *db; |
834 | struct debug_obj *obj; |
835 | unsigned long flags; |
836 | int res = -EINVAL; |
837 | |
838 | db = get_bucket((unsigned long) addr); |
839 | |
840 | raw_spin_lock_irqsave(&db->lock, flags); |
841 | |
842 | obj = lookup_object(addr, db); |
843 | if (!obj && state != ODEBUG_STATE_NONE) { |
844 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); |
845 | goto out; |
846 | } |
847 | if (obj && obj->state != state) { |
848 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", |
849 | obj->state, state); |
850 | goto out; |
851 | } |
852 | if (fixups != debug_objects_fixups) { |
853 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", |
854 | fixups, debug_objects_fixups); |
855 | goto out; |
856 | } |
857 | if (warnings != debug_objects_warnings) { |
858 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", |
859 | warnings, debug_objects_warnings); |
860 | goto out; |
861 | } |
862 | res = 0; |
863 | out: |
864 | raw_spin_unlock_irqrestore(&db->lock, flags); |
865 | if (res) |
866 | debug_objects_enabled = 0; |
867 | return res; |
868 | } |
869 | |
870 | static __initdata struct debug_obj_descr descr_type_test = { |
871 | .name = "selftest", |
872 | .fixup_init = fixup_init, |
873 | .fixup_activate = fixup_activate, |
874 | .fixup_destroy = fixup_destroy, |
875 | .fixup_free = fixup_free, |
876 | }; |
877 | |
878 | static __initdata struct self_test obj = { .static_init = 0 }; |
879 | |
880 | static void __init debug_objects_selftest(void) |
881 | { |
882 | int fixups, oldfixups, warnings, oldwarnings; |
883 | unsigned long flags; |
884 | |
885 | local_irq_save(flags); |
886 | |
887 | fixups = oldfixups = debug_objects_fixups; |
888 | warnings = oldwarnings = debug_objects_warnings; |
889 | descr_test = &descr_type_test; |
890 | |
891 | debug_object_init(&obj, &descr_type_test); |
892 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) |
893 | goto out; |
894 | debug_object_activate(&obj, &descr_type_test); |
895 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
896 | goto out; |
897 | debug_object_activate(&obj, &descr_type_test); |
898 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) |
899 | goto out; |
900 | debug_object_deactivate(&obj, &descr_type_test); |
901 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) |
902 | goto out; |
903 | debug_object_destroy(&obj, &descr_type_test); |
904 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) |
905 | goto out; |
906 | debug_object_init(&obj, &descr_type_test); |
907 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
908 | goto out; |
909 | debug_object_activate(&obj, &descr_type_test); |
910 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
911 | goto out; |
912 | debug_object_deactivate(&obj, &descr_type_test); |
913 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
914 | goto out; |
915 | debug_object_free(&obj, &descr_type_test); |
916 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) |
917 | goto out; |
918 | |
919 | obj.static_init = 1; |
920 | debug_object_activate(&obj, &descr_type_test); |
921 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings)) |
922 | goto out; |
923 | debug_object_init(&obj, &descr_type_test); |
924 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) |
925 | goto out; |
926 | debug_object_free(&obj, &descr_type_test); |
927 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) |
928 | goto out; |
929 | |
930 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
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_check_no_obj_freed(&obj, sizeof(obj)); |
938 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) |
939 | goto out; |
940 | #endif |
941 | printk(KERN_INFO "ODEBUG: selftest passed\n"); |
942 | |
943 | out: |
944 | debug_objects_fixups = oldfixups; |
945 | debug_objects_warnings = oldwarnings; |
946 | descr_test = NULL; |
947 | |
948 | local_irq_restore(flags); |
949 | } |
950 | #else |
951 | static inline void debug_objects_selftest(void) { } |
952 | #endif |
953 | |
954 | /* |
955 | * Called during early boot to initialize the hash buckets and link |
956 | * the static object pool objects into the poll list. After this call |
957 | * the object tracker is fully operational. |
958 | */ |
959 | void __init debug_objects_early_init(void) |
960 | { |
961 | int i; |
962 | |
963 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) |
964 | raw_spin_lock_init(&obj_hash[i].lock); |
965 | |
966 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) |
967 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); |
968 | } |
969 | |
970 | /* |
971 | * Convert the statically allocated objects to dynamic ones: |
972 | */ |
973 | static int __init debug_objects_replace_static_objects(void) |
974 | { |
975 | struct debug_bucket *db = obj_hash; |
976 | struct hlist_node *node, *tmp; |
977 | struct debug_obj *obj, *new; |
978 | HLIST_HEAD(objects); |
979 | int i, cnt = 0; |
980 | |
981 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) { |
982 | obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL); |
983 | if (!obj) |
984 | goto free; |
985 | hlist_add_head(&obj->node, &objects); |
986 | } |
987 | |
988 | /* |
989 | * When debug_objects_mem_init() is called we know that only |
990 | * one CPU is up, so disabling interrupts is enough |
991 | * protection. This avoids the lockdep hell of lock ordering. |
992 | */ |
993 | local_irq_disable(); |
994 | |
995 | /* Remove the statically allocated objects from the pool */ |
996 | hlist_for_each_entry_safe(obj, node, tmp, &obj_pool, node) |
997 | hlist_del(&obj->node); |
998 | /* Move the allocated objects to the pool */ |
999 | hlist_move_list(&objects, &obj_pool); |
1000 | |
1001 | /* Replace the active object references */ |
1002 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
1003 | hlist_move_list(&db->list, &objects); |
1004 | |
1005 | hlist_for_each_entry(obj, node, &objects, node) { |
1006 | new = hlist_entry(obj_pool.first, typeof(*obj), node); |
1007 | hlist_del(&new->node); |
1008 | /* copy object data */ |
1009 | *new = *obj; |
1010 | hlist_add_head(&new->node, &db->list); |
1011 | cnt++; |
1012 | } |
1013 | } |
1014 | |
1015 | printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt, |
1016 | obj_pool_used); |
1017 | local_irq_enable(); |
1018 | return 0; |
1019 | free: |
1020 | hlist_for_each_entry_safe(obj, node, tmp, &objects, node) { |
1021 | hlist_del(&obj->node); |
1022 | kmem_cache_free(obj_cache, obj); |
1023 | } |
1024 | return -ENOMEM; |
1025 | } |
1026 | |
1027 | /* |
1028 | * Called after the kmem_caches are functional to setup a dedicated |
1029 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag |
1030 | * prevents that the debug code is called on kmem_cache_free() for the |
1031 | * debug tracker objects to avoid recursive calls. |
1032 | */ |
1033 | void __init debug_objects_mem_init(void) |
1034 | { |
1035 | if (!debug_objects_enabled) |
1036 | return; |
1037 | |
1038 | obj_cache = kmem_cache_create("debug_objects_cache", |
1039 | sizeof (struct debug_obj), 0, |
1040 | SLAB_DEBUG_OBJECTS, NULL); |
1041 | |
1042 | if (!obj_cache || debug_objects_replace_static_objects()) { |
1043 | debug_objects_enabled = 0; |
1044 | if (obj_cache) |
1045 | kmem_cache_destroy(obj_cache); |
1046 | printk(KERN_WARNING "ODEBUG: out of memory.\n"); |
1047 | } else |
1048 | debug_objects_selftest(); |
1049 | } |
1050 |
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Tags:
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od-2011-09-18
v2.6.34-rc5
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