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; | |
71 | ||
72 | if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL)) | |
73 | return obj_pool_free; | |
74 | ||
75 | if (unlikely(!obj_cache)) | |
76 | return obj_pool_free; | |
77 | ||
78 | while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) { | |
79 | ||
80 | new = kmem_cache_zalloc(obj_cache, gfp); | |
81 | if (!new) | |
82 | return obj_pool_free; | |
83 | ||
84 | spin_lock(&pool_lock); | |
85 | hlist_add_head(&new->node, &obj_pool); | |
86 | obj_pool_free++; | |
87 | spin_unlock(&pool_lock); | |
88 | } | |
89 | return obj_pool_free; | |
90 | } | |
91 | ||
92 | /* | |
93 | * Lookup an object in the hash bucket. | |
94 | */ | |
95 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) | |
96 | { | |
97 | struct hlist_node *node; | |
98 | struct debug_obj *obj; | |
99 | int cnt = 0; | |
100 | ||
101 | hlist_for_each_entry(obj, node, &b->list, node) { | |
102 | cnt++; | |
103 | if (obj->object == addr) | |
104 | return obj; | |
105 | } | |
106 | if (cnt > debug_objects_maxchain) | |
107 | debug_objects_maxchain = cnt; | |
108 | ||
109 | return NULL; | |
110 | } | |
111 | ||
112 | /* | |
113 | * Allocate a new object. If the pool is empty and no refill possible, | |
114 | * switch off the debugger. | |
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; | |
120 | int retry = 0; | |
121 | ||
122 | repeat: | |
123 | spin_lock(&pool_lock); | |
124 | if (obj_pool.first) { | |
125 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); | |
126 | ||
127 | obj->object = addr; | |
128 | obj->descr = descr; | |
129 | obj->state = ODEBUG_STATE_NONE; | |
130 | hlist_del(&obj->node); | |
131 | ||
132 | hlist_add_head(&obj->node, &b->list); | |
133 | ||
134 | obj_pool_used++; | |
135 | if (obj_pool_used > obj_pool_max_used) | |
136 | obj_pool_max_used = obj_pool_used; | |
137 | ||
138 | obj_pool_free--; | |
139 | if (obj_pool_free < obj_pool_min_free) | |
140 | obj_pool_min_free = obj_pool_free; | |
141 | } | |
142 | spin_unlock(&pool_lock); | |
143 | ||
144 | if (fill_pool() && !obj && !retry++) | |
145 | goto repeat; | |
146 | ||
147 | return obj; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Put the object back into the pool or give it back to kmem_cache: | |
152 | */ | |
153 | static void free_object(struct debug_obj *obj) | |
154 | { | |
155 | unsigned long idx = (unsigned long)(obj - obj_static_pool); | |
156 | ||
157 | if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) { | |
158 | spin_lock(&pool_lock); | |
159 | hlist_add_head(&obj->node, &obj_pool); | |
160 | obj_pool_free++; | |
161 | obj_pool_used--; | |
162 | spin_unlock(&pool_lock); | |
163 | } else { | |
164 | spin_lock(&pool_lock); | |
165 | obj_pool_used--; | |
166 | spin_unlock(&pool_lock); | |
167 | kmem_cache_free(obj_cache, obj); | |
168 | } | |
169 | } | |
170 | ||
171 | /* | |
172 | * We run out of memory. That means we probably have tons of objects | |
173 | * allocated. | |
174 | */ | |
175 | static void debug_objects_oom(void) | |
176 | { | |
177 | struct debug_bucket *db = obj_hash; | |
178 | struct hlist_node *node, *tmp; | |
179 | struct debug_obj *obj; | |
180 | unsigned long flags; | |
181 | int i; | |
182 | ||
183 | printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n"); | |
184 | ||
185 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { | |
186 | spin_lock_irqsave(&db->lock, flags); | |
187 | hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { | |
188 | hlist_del(&obj->node); | |
189 | free_object(obj); | |
190 | } | |
191 | spin_unlock_irqrestore(&db->lock, flags); | |
192 | } | |
193 | } | |
194 | ||
195 | /* | |
196 | * We use the pfn of the address for the hash. That way we can check | |
197 | * for freed objects simply by checking the affected bucket. | |
198 | */ | |
199 | static struct debug_bucket *get_bucket(unsigned long addr) | |
200 | { | |
201 | unsigned long hash; | |
202 | ||
203 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); | |
204 | return &obj_hash[hash]; | |
205 | } | |
206 | ||
207 | static void debug_print_object(struct debug_obj *obj, char *msg) | |
208 | { | |
209 | static int limit; | |
210 | ||
211 | if (limit < 5 && obj->descr != descr_test) { | |
212 | limit++; | |
213 | printk(KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, | |
214 | obj_states[obj->state], obj->descr->name); | |
215 | WARN_ON(1); | |
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 | { | |
234 | void *stack = current->stack; | |
235 | int is_on_stack; | |
236 | static int limit; | |
237 | ||
238 | if (limit > 4) | |
239 | return; | |
240 | ||
241 | is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE)); | |
242 | ||
243 | if (is_on_stack == onstack) | |
244 | return; | |
245 | ||
246 | limit++; | |
247 | if (is_on_stack) | |
248 | printk(KERN_WARNING | |
249 | "ODEBUG: object is on stack, but not annotated\n"); | |
250 | else | |
251 | printk(KERN_WARNING | |
252 | "ODEBUG: object is not on stack, but annotated\n"); | |
253 | WARN_ON(1); | |
254 | } | |
255 | ||
256 | static void | |
257 | __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) | |
258 | { | |
259 | enum debug_obj_state state; | |
260 | struct debug_bucket *db; | |
261 | struct debug_obj *obj; | |
262 | unsigned long flags; | |
263 | ||
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); | |
507 | free_object(obj); | |
508 | break; | |
509 | } | |
510 | out_unlock: | |
511 | spin_unlock_irqrestore(&db->lock, flags); | |
512 | } | |
513 | ||
514 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
515 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) | |
516 | { | |
517 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; | |
518 | struct hlist_node *node, *tmp; | |
519 | struct debug_obj_descr *descr; | |
520 | enum debug_obj_state state; | |
521 | struct debug_bucket *db; | |
522 | struct debug_obj *obj; | |
523 | int cnt; | |
524 | ||
525 | saddr = (unsigned long) address; | |
526 | eaddr = saddr + size; | |
527 | paddr = saddr & ODEBUG_CHUNK_MASK; | |
528 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); | |
529 | chunks >>= ODEBUG_CHUNK_SHIFT; | |
530 | ||
531 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { | |
532 | db = get_bucket(paddr); | |
533 | ||
534 | repeat: | |
535 | cnt = 0; | |
536 | spin_lock_irqsave(&db->lock, flags); | |
537 | hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { | |
538 | cnt++; | |
539 | oaddr = (unsigned long) obj->object; | |
540 | if (oaddr < saddr || oaddr >= eaddr) | |
541 | continue; | |
542 | ||
543 | switch (obj->state) { | |
544 | case ODEBUG_STATE_ACTIVE: | |
545 | debug_print_object(obj, "free"); | |
546 | descr = obj->descr; | |
547 | state = obj->state; | |
548 | spin_unlock_irqrestore(&db->lock, flags); | |
549 | debug_object_fixup(descr->fixup_free, | |
550 | (void *) oaddr, state); | |
551 | goto repeat; | |
552 | default: | |
553 | hlist_del(&obj->node); | |
554 | free_object(obj); | |
555 | break; | |
556 | } | |
557 | } | |
558 | spin_unlock_irqrestore(&db->lock, flags); | |
559 | if (cnt > debug_objects_maxchain) | |
560 | debug_objects_maxchain = cnt; | |
561 | } | |
562 | } | |
563 | ||
564 | void debug_check_no_obj_freed(const void *address, unsigned long size) | |
565 | { | |
566 | if (debug_objects_enabled) | |
567 | __debug_check_no_obj_freed(address, size); | |
568 | } | |
569 | #endif | |
570 | ||
571 | #ifdef CONFIG_DEBUG_FS | |
572 | ||
573 | static int debug_stats_show(struct seq_file *m, void *v) | |
574 | { | |
575 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); | |
576 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); | |
577 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); | |
578 | seq_printf(m, "pool_free :%d\n", obj_pool_free); | |
579 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); | |
580 | seq_printf(m, "pool_used :%d\n", obj_pool_used); | |
581 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); | |
582 | return 0; | |
583 | } | |
584 | ||
585 | static int debug_stats_open(struct inode *inode, struct file *filp) | |
586 | { | |
587 | return single_open(filp, debug_stats_show, NULL); | |
588 | } | |
589 | ||
590 | static const struct file_operations debug_stats_fops = { | |
591 | .open = debug_stats_open, | |
592 | .read = seq_read, | |
593 | .llseek = seq_lseek, | |
594 | .release = single_release, | |
595 | }; | |
596 | ||
597 | static int __init debug_objects_init_debugfs(void) | |
598 | { | |
599 | struct dentry *dbgdir, *dbgstats; | |
600 | ||
601 | if (!debug_objects_enabled) | |
602 | return 0; | |
603 | ||
604 | dbgdir = debugfs_create_dir("debug_objects", NULL); | |
605 | if (!dbgdir) | |
606 | return -ENOMEM; | |
607 | ||
608 | dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, | |
609 | &debug_stats_fops); | |
610 | if (!dbgstats) | |
611 | goto err; | |
612 | ||
613 | return 0; | |
614 | ||
615 | err: | |
616 | debugfs_remove(dbgdir); | |
617 | ||
618 | return -ENOMEM; | |
619 | } | |
620 | __initcall(debug_objects_init_debugfs); | |
621 | ||
622 | #else | |
623 | static inline void debug_objects_init_debugfs(void) { } | |
624 | #endif | |
625 | ||
626 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST | |
627 | ||
628 | /* Random data structure for the self test */ | |
629 | struct self_test { | |
630 | unsigned long dummy1[6]; | |
631 | int static_init; | |
632 | unsigned long dummy2[3]; | |
633 | }; | |
634 | ||
635 | static __initdata struct debug_obj_descr descr_type_test; | |
636 | ||
637 | /* | |
638 | * fixup_init is called when: | |
639 | * - an active object is initialized | |
640 | */ | |
641 | static int __init fixup_init(void *addr, enum debug_obj_state state) | |
642 | { | |
643 | struct self_test *obj = addr; | |
644 | ||
645 | switch (state) { | |
646 | case ODEBUG_STATE_ACTIVE: | |
647 | debug_object_deactivate(obj, &descr_type_test); | |
648 | debug_object_init(obj, &descr_type_test); | |
649 | return 1; | |
650 | default: | |
651 | return 0; | |
652 | } | |
653 | } | |
654 | ||
655 | /* | |
656 | * fixup_activate is called when: | |
657 | * - an active object is activated | |
658 | * - an unknown object is activated (might be a statically initialized object) | |
659 | */ | |
660 | static int __init fixup_activate(void *addr, enum debug_obj_state state) | |
661 | { | |
662 | struct self_test *obj = addr; | |
663 | ||
664 | switch (state) { | |
665 | case ODEBUG_STATE_NOTAVAILABLE: | |
666 | if (obj->static_init == 1) { | |
667 | debug_object_init(obj, &descr_type_test); | |
668 | debug_object_activate(obj, &descr_type_test); | |
669 | /* | |
670 | * Real code should return 0 here ! This is | |
671 | * not a fixup of some bad behaviour. We | |
672 | * merily call the debug_init function to keep | |
673 | * track of the object. | |
674 | */ | |
675 | return 1; | |
676 | } else { | |
677 | /* Real code needs to emit a warning here */ | |
678 | } | |
679 | return 0; | |
680 | ||
681 | case ODEBUG_STATE_ACTIVE: | |
682 | debug_object_deactivate(obj, &descr_type_test); | |
683 | debug_object_activate(obj, &descr_type_test); | |
684 | return 1; | |
685 | ||
686 | default: | |
687 | return 0; | |
688 | } | |
689 | } | |
690 | ||
691 | /* | |
692 | * fixup_destroy is called when: | |
693 | * - an active object is destroyed | |
694 | */ | |
695 | static int __init fixup_destroy(void *addr, enum debug_obj_state state) | |
696 | { | |
697 | struct self_test *obj = addr; | |
698 | ||
699 | switch (state) { | |
700 | case ODEBUG_STATE_ACTIVE: | |
701 | debug_object_deactivate(obj, &descr_type_test); | |
702 | debug_object_destroy(obj, &descr_type_test); | |
703 | return 1; | |
704 | default: | |
705 | return 0; | |
706 | } | |
707 | } | |
708 | ||
709 | /* | |
710 | * fixup_free is called when: | |
711 | * - an active object is freed | |
712 | */ | |
713 | static int __init fixup_free(void *addr, enum debug_obj_state state) | |
714 | { | |
715 | struct self_test *obj = addr; | |
716 | ||
717 | switch (state) { | |
718 | case ODEBUG_STATE_ACTIVE: | |
719 | debug_object_deactivate(obj, &descr_type_test); | |
720 | debug_object_free(obj, &descr_type_test); | |
721 | return 1; | |
722 | default: | |
723 | return 0; | |
724 | } | |
725 | } | |
726 | ||
727 | static int | |
728 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) | |
729 | { | |
730 | struct debug_bucket *db; | |
731 | struct debug_obj *obj; | |
732 | unsigned long flags; | |
733 | int res = -EINVAL; | |
734 | ||
735 | db = get_bucket((unsigned long) addr); | |
736 | ||
737 | spin_lock_irqsave(&db->lock, flags); | |
738 | ||
739 | obj = lookup_object(addr, db); | |
740 | if (!obj && state != ODEBUG_STATE_NONE) { | |
741 | printk(KERN_ERR "ODEBUG: selftest object not found\n"); | |
742 | WARN_ON(1); | |
743 | goto out; | |
744 | } | |
745 | if (obj && obj->state != state) { | |
746 | printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", | |
747 | obj->state, state); | |
748 | WARN_ON(1); | |
749 | goto out; | |
750 | } | |
751 | if (fixups != debug_objects_fixups) { | |
752 | printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", | |
753 | fixups, debug_objects_fixups); | |
754 | WARN_ON(1); | |
755 | goto out; | |
756 | } | |
757 | if (warnings != debug_objects_warnings) { | |
758 | printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", | |
759 | warnings, debug_objects_warnings); | |
760 | WARN_ON(1); | |
761 | goto out; | |
762 | } | |
763 | res = 0; | |
764 | out: | |
765 | spin_unlock_irqrestore(&db->lock, flags); | |
766 | if (res) | |
767 | debug_objects_enabled = 0; | |
768 | return res; | |
769 | } | |
770 | ||
771 | static __initdata struct debug_obj_descr descr_type_test = { | |
772 | .name = "selftest", | |
773 | .fixup_init = fixup_init, | |
774 | .fixup_activate = fixup_activate, | |
775 | .fixup_destroy = fixup_destroy, | |
776 | .fixup_free = fixup_free, | |
777 | }; | |
778 | ||
779 | static __initdata struct self_test obj = { .static_init = 0 }; | |
780 | ||
781 | static void __init debug_objects_selftest(void) | |
782 | { | |
783 | int fixups, oldfixups, warnings, oldwarnings; | |
784 | unsigned long flags; | |
785 | ||
786 | local_irq_save(flags); | |
787 | ||
788 | fixups = oldfixups = debug_objects_fixups; | |
789 | warnings = oldwarnings = debug_objects_warnings; | |
790 | descr_test = &descr_type_test; | |
791 | ||
792 | debug_object_init(&obj, &descr_type_test); | |
793 | if (check_results(&obj, ODEBUG_STATE_INIT, 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_activate(&obj, &descr_type_test); | |
799 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) | |
800 | goto out; | |
801 | debug_object_deactivate(&obj, &descr_type_test); | |
802 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) | |
803 | goto out; | |
804 | debug_object_destroy(&obj, &descr_type_test); | |
805 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) | |
806 | goto out; | |
807 | debug_object_init(&obj, &descr_type_test); | |
808 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
809 | goto out; | |
810 | debug_object_activate(&obj, &descr_type_test); | |
811 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
812 | goto out; | |
813 | debug_object_deactivate(&obj, &descr_type_test); | |
814 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
815 | goto out; | |
816 | debug_object_free(&obj, &descr_type_test); | |
817 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
818 | goto out; | |
819 | ||
820 | obj.static_init = 1; | |
821 | debug_object_activate(&obj, &descr_type_test); | |
822 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings)) | |
823 | goto out; | |
824 | debug_object_init(&obj, &descr_type_test); | |
825 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) | |
826 | goto out; | |
827 | debug_object_free(&obj, &descr_type_test); | |
828 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
829 | goto out; | |
830 | ||
831 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
832 | debug_object_init(&obj, &descr_type_test); | |
833 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
834 | goto out; | |
835 | debug_object_activate(&obj, &descr_type_test); | |
836 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
837 | goto out; | |
838 | __debug_check_no_obj_freed(&obj, sizeof(obj)); | |
839 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) | |
840 | goto out; | |
841 | #endif | |
842 | printk(KERN_INFO "ODEBUG: selftest passed\n"); | |
843 | ||
844 | out: | |
845 | debug_objects_fixups = oldfixups; | |
846 | debug_objects_warnings = oldwarnings; | |
847 | descr_test = NULL; | |
848 | ||
849 | local_irq_restore(flags); | |
850 | } | |
851 | #else | |
852 | static inline void debug_objects_selftest(void) { } | |
853 | #endif | |
854 | ||
855 | /* | |
856 | * Called during early boot to initialize the hash buckets and link | |
857 | * the static object pool objects into the poll list. After this call | |
858 | * the object tracker is fully operational. | |
859 | */ | |
860 | void __init debug_objects_early_init(void) | |
861 | { | |
862 | int i; | |
863 | ||
864 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) | |
865 | spin_lock_init(&obj_hash[i].lock); | |
866 | ||
867 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) | |
868 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); | |
869 | } | |
870 | ||
871 | /* | |
872 | * Called after the kmem_caches are functional to setup a dedicated | |
873 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag | |
874 | * prevents that the debug code is called on kmem_cache_free() for the | |
875 | * debug tracker objects to avoid recursive calls. | |
876 | */ | |
877 | void __init debug_objects_mem_init(void) | |
878 | { | |
879 | if (!debug_objects_enabled) | |
880 | return; | |
881 | ||
882 | obj_cache = kmem_cache_create("debug_objects_cache", | |
883 | sizeof (struct debug_obj), 0, | |
884 | SLAB_DEBUG_OBJECTS, NULL); | |
885 | ||
886 | if (!obj_cache) | |
887 | debug_objects_enabled = 0; | |
888 | else | |
889 | debug_objects_selftest(); | |
890 | } |