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. |
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++; | |
5cd2b459 | 208 | WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, |
3ac7fe5a | 209 | obj_states[obj->state], obj->descr->name); |
3ac7fe5a TG |
210 | } |
211 | debug_objects_warnings++; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Try to repair the damage, so we have a better chance to get useful | |
216 | * debug output. | |
217 | */ | |
218 | static void | |
219 | debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), | |
220 | void * addr, enum debug_obj_state state) | |
221 | { | |
222 | if (fixup) | |
223 | debug_objects_fixups += fixup(addr, state); | |
224 | } | |
225 | ||
226 | static void debug_object_is_on_stack(void *addr, int onstack) | |
227 | { | |
3ac7fe5a TG |
228 | int is_on_stack; |
229 | static int limit; | |
230 | ||
231 | if (limit > 4) | |
232 | return; | |
233 | ||
8b05c7e6 | 234 | is_on_stack = object_is_on_stack(addr); |
3ac7fe5a TG |
235 | if (is_on_stack == onstack) |
236 | return; | |
237 | ||
238 | limit++; | |
239 | if (is_on_stack) | |
240 | printk(KERN_WARNING | |
241 | "ODEBUG: object is on stack, but not annotated\n"); | |
242 | else | |
243 | printk(KERN_WARNING | |
244 | "ODEBUG: object is not on stack, but annotated\n"); | |
245 | WARN_ON(1); | |
246 | } | |
247 | ||
248 | static void | |
249 | __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) | |
250 | { | |
251 | enum debug_obj_state state; | |
252 | struct debug_bucket *db; | |
253 | struct debug_obj *obj; | |
254 | unsigned long flags; | |
255 | ||
50db04dd VN |
256 | fill_pool(); |
257 | ||
3ac7fe5a TG |
258 | db = get_bucket((unsigned long) addr); |
259 | ||
260 | spin_lock_irqsave(&db->lock, flags); | |
261 | ||
262 | obj = lookup_object(addr, db); | |
263 | if (!obj) { | |
264 | obj = alloc_object(addr, db, descr); | |
265 | if (!obj) { | |
266 | debug_objects_enabled = 0; | |
267 | spin_unlock_irqrestore(&db->lock, flags); | |
268 | debug_objects_oom(); | |
269 | return; | |
270 | } | |
271 | debug_object_is_on_stack(addr, onstack); | |
272 | } | |
273 | ||
274 | switch (obj->state) { | |
275 | case ODEBUG_STATE_NONE: | |
276 | case ODEBUG_STATE_INIT: | |
277 | case ODEBUG_STATE_INACTIVE: | |
278 | obj->state = ODEBUG_STATE_INIT; | |
279 | break; | |
280 | ||
281 | case ODEBUG_STATE_ACTIVE: | |
282 | debug_print_object(obj, "init"); | |
283 | state = obj->state; | |
284 | spin_unlock_irqrestore(&db->lock, flags); | |
285 | debug_object_fixup(descr->fixup_init, addr, state); | |
286 | return; | |
287 | ||
288 | case ODEBUG_STATE_DESTROYED: | |
289 | debug_print_object(obj, "init"); | |
290 | break; | |
291 | default: | |
292 | break; | |
293 | } | |
294 | ||
295 | spin_unlock_irqrestore(&db->lock, flags); | |
296 | } | |
297 | ||
298 | /** | |
299 | * debug_object_init - debug checks when an object is initialized | |
300 | * @addr: address of the object | |
301 | * @descr: pointer to an object specific debug description structure | |
302 | */ | |
303 | void debug_object_init(void *addr, struct debug_obj_descr *descr) | |
304 | { | |
305 | if (!debug_objects_enabled) | |
306 | return; | |
307 | ||
308 | __debug_object_init(addr, descr, 0); | |
309 | } | |
310 | ||
311 | /** | |
312 | * debug_object_init_on_stack - debug checks when an object on stack is | |
313 | * initialized | |
314 | * @addr: address of the object | |
315 | * @descr: pointer to an object specific debug description structure | |
316 | */ | |
317 | void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) | |
318 | { | |
319 | if (!debug_objects_enabled) | |
320 | return; | |
321 | ||
322 | __debug_object_init(addr, descr, 1); | |
323 | } | |
324 | ||
325 | /** | |
326 | * debug_object_activate - debug checks when an object is activated | |
327 | * @addr: address of the object | |
328 | * @descr: pointer to an object specific debug description structure | |
329 | */ | |
330 | void debug_object_activate(void *addr, struct debug_obj_descr *descr) | |
331 | { | |
332 | enum debug_obj_state state; | |
333 | struct debug_bucket *db; | |
334 | struct debug_obj *obj; | |
335 | unsigned long flags; | |
336 | ||
337 | if (!debug_objects_enabled) | |
338 | return; | |
339 | ||
340 | db = get_bucket((unsigned long) addr); | |
341 | ||
342 | spin_lock_irqsave(&db->lock, flags); | |
343 | ||
344 | obj = lookup_object(addr, db); | |
345 | if (obj) { | |
346 | switch (obj->state) { | |
347 | case ODEBUG_STATE_INIT: | |
348 | case ODEBUG_STATE_INACTIVE: | |
349 | obj->state = ODEBUG_STATE_ACTIVE; | |
350 | break; | |
351 | ||
352 | case ODEBUG_STATE_ACTIVE: | |
353 | debug_print_object(obj, "activate"); | |
354 | state = obj->state; | |
355 | spin_unlock_irqrestore(&db->lock, flags); | |
356 | debug_object_fixup(descr->fixup_activate, addr, state); | |
357 | return; | |
358 | ||
359 | case ODEBUG_STATE_DESTROYED: | |
360 | debug_print_object(obj, "activate"); | |
361 | break; | |
362 | default: | |
363 | break; | |
364 | } | |
365 | spin_unlock_irqrestore(&db->lock, flags); | |
366 | return; | |
367 | } | |
368 | ||
369 | spin_unlock_irqrestore(&db->lock, flags); | |
370 | /* | |
371 | * This happens when a static object is activated. We | |
372 | * let the type specific code decide whether this is | |
373 | * true or not. | |
374 | */ | |
375 | debug_object_fixup(descr->fixup_activate, addr, | |
376 | ODEBUG_STATE_NOTAVAILABLE); | |
377 | } | |
378 | ||
379 | /** | |
380 | * debug_object_deactivate - debug checks when an object is deactivated | |
381 | * @addr: address of the object | |
382 | * @descr: pointer to an object specific debug description structure | |
383 | */ | |
384 | void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) | |
385 | { | |
386 | struct debug_bucket *db; | |
387 | struct debug_obj *obj; | |
388 | unsigned long flags; | |
389 | ||
390 | if (!debug_objects_enabled) | |
391 | return; | |
392 | ||
393 | db = get_bucket((unsigned long) addr); | |
394 | ||
395 | spin_lock_irqsave(&db->lock, flags); | |
396 | ||
397 | obj = lookup_object(addr, db); | |
398 | if (obj) { | |
399 | switch (obj->state) { | |
400 | case ODEBUG_STATE_INIT: | |
401 | case ODEBUG_STATE_INACTIVE: | |
402 | case ODEBUG_STATE_ACTIVE: | |
403 | obj->state = ODEBUG_STATE_INACTIVE; | |
404 | break; | |
405 | ||
406 | case ODEBUG_STATE_DESTROYED: | |
407 | debug_print_object(obj, "deactivate"); | |
408 | break; | |
409 | default: | |
410 | break; | |
411 | } | |
412 | } else { | |
413 | struct debug_obj o = { .object = addr, | |
414 | .state = ODEBUG_STATE_NOTAVAILABLE, | |
415 | .descr = descr }; | |
416 | ||
417 | debug_print_object(&o, "deactivate"); | |
418 | } | |
419 | ||
420 | spin_unlock_irqrestore(&db->lock, flags); | |
421 | } | |
422 | ||
423 | /** | |
424 | * debug_object_destroy - debug checks when an object is destroyed | |
425 | * @addr: address of the object | |
426 | * @descr: pointer to an object specific debug description structure | |
427 | */ | |
428 | void debug_object_destroy(void *addr, struct debug_obj_descr *descr) | |
429 | { | |
430 | enum debug_obj_state state; | |
431 | struct debug_bucket *db; | |
432 | struct debug_obj *obj; | |
433 | unsigned long flags; | |
434 | ||
435 | if (!debug_objects_enabled) | |
436 | return; | |
437 | ||
438 | db = get_bucket((unsigned long) addr); | |
439 | ||
440 | spin_lock_irqsave(&db->lock, flags); | |
441 | ||
442 | obj = lookup_object(addr, db); | |
443 | if (!obj) | |
444 | goto out_unlock; | |
445 | ||
446 | switch (obj->state) { | |
447 | case ODEBUG_STATE_NONE: | |
448 | case ODEBUG_STATE_INIT: | |
449 | case ODEBUG_STATE_INACTIVE: | |
450 | obj->state = ODEBUG_STATE_DESTROYED; | |
451 | break; | |
452 | case ODEBUG_STATE_ACTIVE: | |
453 | debug_print_object(obj, "destroy"); | |
454 | state = obj->state; | |
455 | spin_unlock_irqrestore(&db->lock, flags); | |
456 | debug_object_fixup(descr->fixup_destroy, addr, state); | |
457 | return; | |
458 | ||
459 | case ODEBUG_STATE_DESTROYED: | |
460 | debug_print_object(obj, "destroy"); | |
461 | break; | |
462 | default: | |
463 | break; | |
464 | } | |
465 | out_unlock: | |
466 | spin_unlock_irqrestore(&db->lock, flags); | |
467 | } | |
468 | ||
469 | /** | |
470 | * debug_object_free - debug checks when an object is freed | |
471 | * @addr: address of the object | |
472 | * @descr: pointer to an object specific debug description structure | |
473 | */ | |
474 | void debug_object_free(void *addr, struct debug_obj_descr *descr) | |
475 | { | |
476 | enum debug_obj_state state; | |
477 | struct debug_bucket *db; | |
478 | struct debug_obj *obj; | |
479 | unsigned long flags; | |
480 | ||
481 | if (!debug_objects_enabled) | |
482 | return; | |
483 | ||
484 | db = get_bucket((unsigned long) addr); | |
485 | ||
486 | spin_lock_irqsave(&db->lock, flags); | |
487 | ||
488 | obj = lookup_object(addr, db); | |
489 | if (!obj) | |
490 | goto out_unlock; | |
491 | ||
492 | switch (obj->state) { | |
493 | case ODEBUG_STATE_ACTIVE: | |
494 | debug_print_object(obj, "free"); | |
495 | state = obj->state; | |
496 | spin_unlock_irqrestore(&db->lock, flags); | |
497 | debug_object_fixup(descr->fixup_free, addr, state); | |
498 | return; | |
499 | default: | |
500 | hlist_del(&obj->node); | |
501 | free_object(obj); | |
502 | break; | |
503 | } | |
504 | out_unlock: | |
505 | spin_unlock_irqrestore(&db->lock, flags); | |
506 | } | |
507 | ||
508 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
509 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) | |
510 | { | |
511 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; | |
512 | struct hlist_node *node, *tmp; | |
513 | struct debug_obj_descr *descr; | |
514 | enum debug_obj_state state; | |
515 | struct debug_bucket *db; | |
516 | struct debug_obj *obj; | |
517 | int cnt; | |
518 | ||
519 | saddr = (unsigned long) address; | |
520 | eaddr = saddr + size; | |
521 | paddr = saddr & ODEBUG_CHUNK_MASK; | |
522 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); | |
523 | chunks >>= ODEBUG_CHUNK_SHIFT; | |
524 | ||
525 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { | |
526 | db = get_bucket(paddr); | |
527 | ||
528 | repeat: | |
529 | cnt = 0; | |
530 | spin_lock_irqsave(&db->lock, flags); | |
531 | hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { | |
532 | cnt++; | |
533 | oaddr = (unsigned long) obj->object; | |
534 | if (oaddr < saddr || oaddr >= eaddr) | |
535 | continue; | |
536 | ||
537 | switch (obj->state) { | |
538 | case ODEBUG_STATE_ACTIVE: | |
539 | debug_print_object(obj, "free"); | |
540 | descr = obj->descr; | |
541 | state = obj->state; | |
542 | spin_unlock_irqrestore(&db->lock, flags); | |
543 | debug_object_fixup(descr->fixup_free, | |
544 | (void *) oaddr, state); | |
545 | goto repeat; | |
546 | default: | |
547 | hlist_del(&obj->node); | |
548 | free_object(obj); | |
549 | break; | |
550 | } | |
551 | } | |
552 | spin_unlock_irqrestore(&db->lock, flags); | |
553 | if (cnt > debug_objects_maxchain) | |
554 | debug_objects_maxchain = cnt; | |
555 | } | |
556 | } | |
557 | ||
558 | void debug_check_no_obj_freed(const void *address, unsigned long size) | |
559 | { | |
560 | if (debug_objects_enabled) | |
561 | __debug_check_no_obj_freed(address, size); | |
562 | } | |
563 | #endif | |
564 | ||
565 | #ifdef CONFIG_DEBUG_FS | |
566 | ||
567 | static int debug_stats_show(struct seq_file *m, void *v) | |
568 | { | |
569 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); | |
570 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); | |
571 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); | |
572 | seq_printf(m, "pool_free :%d\n", obj_pool_free); | |
573 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); | |
574 | seq_printf(m, "pool_used :%d\n", obj_pool_used); | |
575 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); | |
576 | return 0; | |
577 | } | |
578 | ||
579 | static int debug_stats_open(struct inode *inode, struct file *filp) | |
580 | { | |
581 | return single_open(filp, debug_stats_show, NULL); | |
582 | } | |
583 | ||
584 | static const struct file_operations debug_stats_fops = { | |
585 | .open = debug_stats_open, | |
586 | .read = seq_read, | |
587 | .llseek = seq_lseek, | |
588 | .release = single_release, | |
589 | }; | |
590 | ||
591 | static int __init debug_objects_init_debugfs(void) | |
592 | { | |
593 | struct dentry *dbgdir, *dbgstats; | |
594 | ||
595 | if (!debug_objects_enabled) | |
596 | return 0; | |
597 | ||
598 | dbgdir = debugfs_create_dir("debug_objects", NULL); | |
599 | if (!dbgdir) | |
600 | return -ENOMEM; | |
601 | ||
602 | dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, | |
603 | &debug_stats_fops); | |
604 | if (!dbgstats) | |
605 | goto err; | |
606 | ||
607 | return 0; | |
608 | ||
609 | err: | |
610 | debugfs_remove(dbgdir); | |
611 | ||
612 | return -ENOMEM; | |
613 | } | |
614 | __initcall(debug_objects_init_debugfs); | |
615 | ||
616 | #else | |
617 | static inline void debug_objects_init_debugfs(void) { } | |
618 | #endif | |
619 | ||
620 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST | |
621 | ||
622 | /* Random data structure for the self test */ | |
623 | struct self_test { | |
624 | unsigned long dummy1[6]; | |
625 | int static_init; | |
626 | unsigned long dummy2[3]; | |
627 | }; | |
628 | ||
629 | static __initdata struct debug_obj_descr descr_type_test; | |
630 | ||
631 | /* | |
632 | * fixup_init is called when: | |
633 | * - an active object is initialized | |
634 | */ | |
635 | static int __init fixup_init(void *addr, enum debug_obj_state state) | |
636 | { | |
637 | struct self_test *obj = addr; | |
638 | ||
639 | switch (state) { | |
640 | case ODEBUG_STATE_ACTIVE: | |
641 | debug_object_deactivate(obj, &descr_type_test); | |
642 | debug_object_init(obj, &descr_type_test); | |
643 | return 1; | |
644 | default: | |
645 | return 0; | |
646 | } | |
647 | } | |
648 | ||
649 | /* | |
650 | * fixup_activate is called when: | |
651 | * - an active object is activated | |
652 | * - an unknown object is activated (might be a statically initialized object) | |
653 | */ | |
654 | static int __init fixup_activate(void *addr, enum debug_obj_state state) | |
655 | { | |
656 | struct self_test *obj = addr; | |
657 | ||
658 | switch (state) { | |
659 | case ODEBUG_STATE_NOTAVAILABLE: | |
660 | if (obj->static_init == 1) { | |
661 | debug_object_init(obj, &descr_type_test); | |
662 | debug_object_activate(obj, &descr_type_test); | |
663 | /* | |
664 | * Real code should return 0 here ! This is | |
665 | * not a fixup of some bad behaviour. We | |
666 | * merily call the debug_init function to keep | |
667 | * track of the object. | |
668 | */ | |
669 | return 1; | |
670 | } else { | |
671 | /* Real code needs to emit a warning here */ | |
672 | } | |
673 | return 0; | |
674 | ||
675 | case ODEBUG_STATE_ACTIVE: | |
676 | debug_object_deactivate(obj, &descr_type_test); | |
677 | debug_object_activate(obj, &descr_type_test); | |
678 | return 1; | |
679 | ||
680 | default: | |
681 | return 0; | |
682 | } | |
683 | } | |
684 | ||
685 | /* | |
686 | * fixup_destroy is called when: | |
687 | * - an active object is destroyed | |
688 | */ | |
689 | static int __init fixup_destroy(void *addr, enum debug_obj_state state) | |
690 | { | |
691 | struct self_test *obj = addr; | |
692 | ||
693 | switch (state) { | |
694 | case ODEBUG_STATE_ACTIVE: | |
695 | debug_object_deactivate(obj, &descr_type_test); | |
696 | debug_object_destroy(obj, &descr_type_test); | |
697 | return 1; | |
698 | default: | |
699 | return 0; | |
700 | } | |
701 | } | |
702 | ||
703 | /* | |
704 | * fixup_free is called when: | |
705 | * - an active object is freed | |
706 | */ | |
707 | static int __init fixup_free(void *addr, enum debug_obj_state state) | |
708 | { | |
709 | struct self_test *obj = addr; | |
710 | ||
711 | switch (state) { | |
712 | case ODEBUG_STATE_ACTIVE: | |
713 | debug_object_deactivate(obj, &descr_type_test); | |
714 | debug_object_free(obj, &descr_type_test); | |
715 | return 1; | |
716 | default: | |
717 | return 0; | |
718 | } | |
719 | } | |
720 | ||
721 | static int | |
722 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) | |
723 | { | |
724 | struct debug_bucket *db; | |
725 | struct debug_obj *obj; | |
726 | unsigned long flags; | |
727 | int res = -EINVAL; | |
728 | ||
729 | db = get_bucket((unsigned long) addr); | |
730 | ||
731 | spin_lock_irqsave(&db->lock, flags); | |
732 | ||
733 | obj = lookup_object(addr, db); | |
734 | if (!obj && state != ODEBUG_STATE_NONE) { | |
5cd2b459 | 735 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); |
3ac7fe5a TG |
736 | goto out; |
737 | } | |
738 | if (obj && obj->state != state) { | |
5cd2b459 | 739 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", |
3ac7fe5a | 740 | obj->state, state); |
3ac7fe5a TG |
741 | goto out; |
742 | } | |
743 | if (fixups != debug_objects_fixups) { | |
5cd2b459 | 744 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", |
3ac7fe5a | 745 | fixups, debug_objects_fixups); |
3ac7fe5a TG |
746 | goto out; |
747 | } | |
748 | if (warnings != debug_objects_warnings) { | |
5cd2b459 | 749 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", |
3ac7fe5a | 750 | warnings, debug_objects_warnings); |
3ac7fe5a TG |
751 | goto out; |
752 | } | |
753 | res = 0; | |
754 | out: | |
755 | spin_unlock_irqrestore(&db->lock, flags); | |
756 | if (res) | |
757 | debug_objects_enabled = 0; | |
758 | return res; | |
759 | } | |
760 | ||
761 | static __initdata struct debug_obj_descr descr_type_test = { | |
762 | .name = "selftest", | |
763 | .fixup_init = fixup_init, | |
764 | .fixup_activate = fixup_activate, | |
765 | .fixup_destroy = fixup_destroy, | |
766 | .fixup_free = fixup_free, | |
767 | }; | |
768 | ||
769 | static __initdata struct self_test obj = { .static_init = 0 }; | |
770 | ||
771 | static void __init debug_objects_selftest(void) | |
772 | { | |
773 | int fixups, oldfixups, warnings, oldwarnings; | |
774 | unsigned long flags; | |
775 | ||
776 | local_irq_save(flags); | |
777 | ||
778 | fixups = oldfixups = debug_objects_fixups; | |
779 | warnings = oldwarnings = debug_objects_warnings; | |
780 | descr_test = &descr_type_test; | |
781 | ||
782 | debug_object_init(&obj, &descr_type_test); | |
783 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
784 | goto out; | |
785 | debug_object_activate(&obj, &descr_type_test); | |
786 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
787 | goto out; | |
788 | debug_object_activate(&obj, &descr_type_test); | |
789 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) | |
790 | goto out; | |
791 | debug_object_deactivate(&obj, &descr_type_test); | |
792 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) | |
793 | goto out; | |
794 | debug_object_destroy(&obj, &descr_type_test); | |
795 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) | |
796 | goto out; | |
797 | debug_object_init(&obj, &descr_type_test); | |
798 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
799 | goto out; | |
800 | debug_object_activate(&obj, &descr_type_test); | |
801 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
802 | goto out; | |
803 | debug_object_deactivate(&obj, &descr_type_test); | |
804 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) | |
805 | goto out; | |
806 | debug_object_free(&obj, &descr_type_test); | |
807 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
808 | goto out; | |
809 | ||
810 | obj.static_init = 1; | |
811 | debug_object_activate(&obj, &descr_type_test); | |
812 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings)) | |
813 | goto out; | |
814 | debug_object_init(&obj, &descr_type_test); | |
815 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) | |
816 | goto out; | |
817 | debug_object_free(&obj, &descr_type_test); | |
818 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) | |
819 | goto out; | |
820 | ||
821 | #ifdef CONFIG_DEBUG_OBJECTS_FREE | |
822 | debug_object_init(&obj, &descr_type_test); | |
823 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) | |
824 | goto out; | |
825 | debug_object_activate(&obj, &descr_type_test); | |
826 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) | |
827 | goto out; | |
828 | __debug_check_no_obj_freed(&obj, sizeof(obj)); | |
829 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) | |
830 | goto out; | |
831 | #endif | |
832 | printk(KERN_INFO "ODEBUG: selftest passed\n"); | |
833 | ||
834 | out: | |
835 | debug_objects_fixups = oldfixups; | |
836 | debug_objects_warnings = oldwarnings; | |
837 | descr_test = NULL; | |
838 | ||
839 | local_irq_restore(flags); | |
840 | } | |
841 | #else | |
842 | static inline void debug_objects_selftest(void) { } | |
843 | #endif | |
844 | ||
845 | /* | |
846 | * Called during early boot to initialize the hash buckets and link | |
847 | * the static object pool objects into the poll list. After this call | |
848 | * the object tracker is fully operational. | |
849 | */ | |
850 | void __init debug_objects_early_init(void) | |
851 | { | |
852 | int i; | |
853 | ||
854 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) | |
855 | spin_lock_init(&obj_hash[i].lock); | |
856 | ||
857 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) | |
858 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); | |
859 | } | |
860 | ||
861 | /* | |
862 | * Called after the kmem_caches are functional to setup a dedicated | |
863 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag | |
864 | * prevents that the debug code is called on kmem_cache_free() for the | |
865 | * debug tracker objects to avoid recursive calls. | |
866 | */ | |
867 | void __init debug_objects_mem_init(void) | |
868 | { | |
869 | if (!debug_objects_enabled) | |
870 | return; | |
871 | ||
872 | obj_cache = kmem_cache_create("debug_objects_cache", | |
873 | sizeof (struct debug_obj), 0, | |
874 | SLAB_DEBUG_OBJECTS, NULL); | |
875 | ||
876 | if (!obj_cache) | |
877 | debug_objects_enabled = 0; | |
878 | else | |
879 | debug_objects_selftest(); | |
880 | } |