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