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/hash.h> |
16 | |
17 | #define ODEBUG_HASH_BITS 14 |
18 | #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) |
19 | |
20 | #define ODEBUG_POOL_SIZE 512 |
21 | #define ODEBUG_POOL_MIN_LEVEL 256 |
22 | |
23 | #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT |
24 | #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) |
25 | #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) |
26 | |
27 | struct debug_bucket { |
28 | struct hlist_head list; |
29 | spinlock_t lock; |
30 | }; |
31 | |
32 | static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; |
33 | |
34 | static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata; |
35 | |
36 | static DEFINE_SPINLOCK(pool_lock); |
37 | |
38 | static HLIST_HEAD(obj_pool); |
39 | |
40 | static int obj_pool_min_free = ODEBUG_POOL_SIZE; |
41 | static int obj_pool_free = ODEBUG_POOL_SIZE; |
42 | static int obj_pool_used; |
43 | static int obj_pool_max_used; |
44 | static struct kmem_cache *obj_cache; |
45 | |
46 | static int debug_objects_maxchain __read_mostly; |
47 | static int debug_objects_fixups __read_mostly; |
48 | static int debug_objects_warnings __read_mostly; |
49 | static int debug_objects_enabled __read_mostly |
50 | = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; |
51 | |
52 | static struct debug_obj_descr *descr_test __read_mostly; |
53 | |
54 | static void free_obj_work(struct work_struct *work); |
55 | static DECLARE_WORK(debug_obj_work, free_obj_work); |
56 | |
57 | static int __init enable_object_debug(char *str) |
58 | { |
59 | debug_objects_enabled = 1; |
60 | return 0; |
61 | } |
62 | |
63 | static int __init disable_object_debug(char *str) |
64 | { |
65 | debug_objects_enabled = 0; |
66 | return 0; |
67 | } |
68 | |
69 | early_param("debug_objects", enable_object_debug); |
70 | early_param("no_debug_objects", disable_object_debug); |
71 | |
72 | static const char *obj_states[ODEBUG_STATE_MAX] = { |
73 | [ODEBUG_STATE_NONE] = "none", |
74 | [ODEBUG_STATE_INIT] = "initialized", |
75 | [ODEBUG_STATE_INACTIVE] = "inactive", |
76 | [ODEBUG_STATE_ACTIVE] = "active", |
77 | [ODEBUG_STATE_DESTROYED] = "destroyed", |
78 | [ODEBUG_STATE_NOTAVAILABLE] = "not available", |
79 | }; |
80 | |
81 | static int fill_pool(void) |
82 | { |
83 | gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; |
84 | struct debug_obj *new; |
85 | unsigned long flags; |
86 | |
87 | if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL)) |
88 | return obj_pool_free; |
89 | |
90 | if (unlikely(!obj_cache)) |
91 | return obj_pool_free; |
92 | |
93 | while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) { |
94 | |
95 | new = kmem_cache_zalloc(obj_cache, gfp); |
96 | if (!new) |
97 | return obj_pool_free; |
98 | |
99 | spin_lock_irqsave(&pool_lock, flags); |
100 | hlist_add_head(&new->node, &obj_pool); |
101 | obj_pool_free++; |
102 | spin_unlock_irqrestore(&pool_lock, flags); |
103 | } |
104 | return obj_pool_free; |
105 | } |
106 | |
107 | /* |
108 | * Lookup an object in the hash bucket. |
109 | */ |
110 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) |
111 | { |
112 | struct hlist_node *node; |
113 | struct debug_obj *obj; |
114 | int cnt = 0; |
115 | |
116 | hlist_for_each_entry(obj, node, &b->list, node) { |
117 | cnt++; |
118 | if (obj->object == addr) |
119 | return obj; |
120 | } |
121 | if (cnt > debug_objects_maxchain) |
122 | debug_objects_maxchain = cnt; |
123 | |
124 | return NULL; |
125 | } |
126 | |
127 | /* |
128 | * Allocate a new object. If the pool is empty, switch off the debugger. |
129 | * Must be called with interrupts disabled. |
130 | */ |
131 | static struct debug_obj * |
132 | alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) |
133 | { |
134 | struct debug_obj *obj = NULL; |
135 | |
136 | spin_lock(&pool_lock); |
137 | if (obj_pool.first) { |
138 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); |
139 | |
140 | obj->object = addr; |
141 | obj->descr = descr; |
142 | obj->state = ODEBUG_STATE_NONE; |
143 | hlist_del(&obj->node); |
144 | |
145 | hlist_add_head(&obj->node, &b->list); |
146 | |
147 | obj_pool_used++; |
148 | if (obj_pool_used > obj_pool_max_used) |
149 | obj_pool_max_used = obj_pool_used; |
150 | |
151 | obj_pool_free--; |
152 | if (obj_pool_free < obj_pool_min_free) |
153 | obj_pool_min_free = obj_pool_free; |
154 | } |
155 | spin_unlock(&pool_lock); |
156 | |
157 | return obj; |
158 | } |
159 | |
160 | /* |
161 | * workqueue function to free objects. |
162 | */ |
163 | static void free_obj_work(struct work_struct *work) |
164 | { |
165 | struct debug_obj *obj; |
166 | unsigned long flags; |
167 | |
168 | spin_lock_irqsave(&pool_lock, flags); |
169 | while (obj_pool_free > ODEBUG_POOL_SIZE) { |
170 | obj = hlist_entry(obj_pool.first, typeof(*obj), node); |
171 | hlist_del(&obj->node); |
172 | obj_pool_free--; |
173 | /* |
174 | * We release pool_lock across kmem_cache_free() to |
175 | * avoid contention on pool_lock. |
176 | */ |
177 | spin_unlock_irqrestore(&pool_lock, flags); |
178 | kmem_cache_free(obj_cache, obj); |
179 | spin_lock_irqsave(&pool_lock, flags); |
180 | } |
181 | spin_unlock_irqrestore(&pool_lock, flags); |
182 | } |
183 | |
184 | /* |
185 | * Put the object back into the pool and schedule work to free objects |
186 | * if necessary. |
187 | */ |
188 | static void free_object(struct debug_obj *obj) |
189 | { |
190 | unsigned long flags; |
191 | int sched = 0; |
192 | |
193 | spin_lock_irqsave(&pool_lock, flags); |
194 | /* |
195 | * schedule work when the pool is filled and the cache is |
196 | * initialized: |
197 | */ |
198 | if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache) |
199 | sched = !work_pending(&debug_obj_work); |
200 | hlist_add_head(&obj->node, &obj_pool); |
201 | obj_pool_free++; |
202 | obj_pool_used--; |
203 | spin_unlock_irqrestore(&pool_lock, flags); |
204 | if (sched) |
205 | schedule_work(&debug_obj_work); |
206 | } |
207 | |
208 | /* |
209 | * We run out of memory. That means we probably have tons of objects |
210 | * allocated. |
211 | */ |
212 | static void debug_objects_oom(void) |
213 | { |
214 | struct debug_bucket *db = obj_hash; |
215 | struct hlist_node *node, *tmp; |
216 | HLIST_HEAD(freelist); |
217 | struct debug_obj *obj; |
218 | unsigned long flags; |
219 | int i; |
220 | |
221 | printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n"); |
222 | |
223 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
224 | spin_lock_irqsave(&db->lock, flags); |
225 | hlist_move_list(&db->list, &freelist); |
226 | spin_unlock_irqrestore(&db->lock, flags); |
227 | |
228 | /* Now free them */ |
229 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { |
230 | hlist_del(&obj->node); |
231 | free_object(obj); |
232 | } |
233 | } |
234 | } |
235 | |
236 | /* |
237 | * We use the pfn of the address for the hash. That way we can check |
238 | * for freed objects simply by checking the affected bucket. |
239 | */ |
240 | static struct debug_bucket *get_bucket(unsigned long addr) |
241 | { |
242 | unsigned long hash; |
243 | |
244 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); |
245 | return &obj_hash[hash]; |
246 | } |
247 | |
248 | static void debug_print_object(struct debug_obj *obj, char *msg) |
249 | { |
250 | static int limit; |
251 | |
252 | if (limit < 5 && obj->descr != descr_test) { |
253 | limit++; |
254 | WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, |
255 | obj_states[obj->state], obj->descr->name); |
256 | } |
257 | debug_objects_warnings++; |
258 | } |
259 | |
260 | /* |
261 | * Try to repair the damage, so we have a better chance to get useful |
262 | * debug output. |
263 | */ |
264 | static void |
265 | debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), |
266 | void * addr, enum debug_obj_state state) |
267 | { |
268 | if (fixup) |
269 | debug_objects_fixups += fixup(addr, state); |
270 | } |
271 | |
272 | static void debug_object_is_on_stack(void *addr, int onstack) |
273 | { |
274 | int is_on_stack; |
275 | static int limit; |
276 | |
277 | if (limit > 4) |
278 | return; |
279 | |
280 | is_on_stack = object_is_on_stack(addr); |
281 | if (is_on_stack == onstack) |
282 | return; |
283 | |
284 | limit++; |
285 | if (is_on_stack) |
286 | printk(KERN_WARNING |
287 | "ODEBUG: object is on stack, but not annotated\n"); |
288 | else |
289 | printk(KERN_WARNING |
290 | "ODEBUG: object is not on stack, but annotated\n"); |
291 | WARN_ON(1); |
292 | } |
293 | |
294 | static void |
295 | __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) |
296 | { |
297 | enum debug_obj_state state; |
298 | struct debug_bucket *db; |
299 | struct debug_obj *obj; |
300 | unsigned long flags; |
301 | |
302 | fill_pool(); |
303 | |
304 | db = get_bucket((unsigned long) addr); |
305 | |
306 | spin_lock_irqsave(&db->lock, flags); |
307 | |
308 | obj = lookup_object(addr, db); |
309 | if (!obj) { |
310 | obj = alloc_object(addr, db, descr); |
311 | if (!obj) { |
312 | debug_objects_enabled = 0; |
313 | spin_unlock_irqrestore(&db->lock, flags); |
314 | debug_objects_oom(); |
315 | return; |
316 | } |
317 | debug_object_is_on_stack(addr, onstack); |
318 | } |
319 | |
320 | switch (obj->state) { |
321 | case ODEBUG_STATE_NONE: |
322 | case ODEBUG_STATE_INIT: |
323 | case ODEBUG_STATE_INACTIVE: |
324 | obj->state = ODEBUG_STATE_INIT; |
325 | break; |
326 | |
327 | case ODEBUG_STATE_ACTIVE: |
328 | debug_print_object(obj, "init"); |
329 | state = obj->state; |
330 | spin_unlock_irqrestore(&db->lock, flags); |
331 | debug_object_fixup(descr->fixup_init, addr, state); |
332 | return; |
333 | |
334 | case ODEBUG_STATE_DESTROYED: |
335 | debug_print_object(obj, "init"); |
336 | break; |
337 | default: |
338 | break; |
339 | } |
340 | |
341 | spin_unlock_irqrestore(&db->lock, flags); |
342 | } |
343 | |
344 | /** |
345 | * debug_object_init - debug checks when an object is initialized |
346 | * @addr: address of the object |
347 | * @descr: pointer to an object specific debug description structure |
348 | */ |
349 | void debug_object_init(void *addr, struct debug_obj_descr *descr) |
350 | { |
351 | if (!debug_objects_enabled) |
352 | return; |
353 | |
354 | __debug_object_init(addr, descr, 0); |
355 | } |
356 | |
357 | /** |
358 | * debug_object_init_on_stack - debug checks when an object on stack is |
359 | * initialized |
360 | * @addr: address of the object |
361 | * @descr: pointer to an object specific debug description structure |
362 | */ |
363 | void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) |
364 | { |
365 | if (!debug_objects_enabled) |
366 | return; |
367 | |
368 | __debug_object_init(addr, descr, 1); |
369 | } |
370 | |
371 | /** |
372 | * debug_object_activate - debug checks when an object is activated |
373 | * @addr: address of the object |
374 | * @descr: pointer to an object specific debug description structure |
375 | */ |
376 | void debug_object_activate(void *addr, struct debug_obj_descr *descr) |
377 | { |
378 | enum debug_obj_state state; |
379 | struct debug_bucket *db; |
380 | struct debug_obj *obj; |
381 | unsigned long flags; |
382 | |
383 | if (!debug_objects_enabled) |
384 | return; |
385 | |
386 | db = get_bucket((unsigned long) addr); |
387 | |
388 | spin_lock_irqsave(&db->lock, flags); |
389 | |
390 | obj = lookup_object(addr, db); |
391 | if (obj) { |
392 | switch (obj->state) { |
393 | case ODEBUG_STATE_INIT: |
394 | case ODEBUG_STATE_INACTIVE: |
395 | obj->state = ODEBUG_STATE_ACTIVE; |
396 | break; |
397 | |
398 | case ODEBUG_STATE_ACTIVE: |
399 | debug_print_object(obj, "activate"); |
400 | state = obj->state; |
401 | spin_unlock_irqrestore(&db->lock, flags); |
402 | debug_object_fixup(descr->fixup_activate, addr, state); |
403 | return; |
404 | |
405 | case ODEBUG_STATE_DESTROYED: |
406 | debug_print_object(obj, "activate"); |
407 | break; |
408 | default: |
409 | break; |
410 | } |
411 | spin_unlock_irqrestore(&db->lock, flags); |
412 | return; |
413 | } |
414 | |
415 | spin_unlock_irqrestore(&db->lock, flags); |
416 | /* |
417 | * This happens when a static object is activated. We |
418 | * let the type specific code decide whether this is |
419 | * true or not. |
420 | */ |
421 | debug_object_fixup(descr->fixup_activate, addr, |
422 | ODEBUG_STATE_NOTAVAILABLE); |
423 | } |
424 | |
425 | /** |
426 | * debug_object_deactivate - debug checks when an object is deactivated |
427 | * @addr: address of the object |
428 | * @descr: pointer to an object specific debug description structure |
429 | */ |
430 | void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) |
431 | { |
432 | struct debug_bucket *db; |
433 | struct debug_obj *obj; |
434 | unsigned long flags; |
435 | |
436 | if (!debug_objects_enabled) |
437 | return; |
438 | |
439 | db = get_bucket((unsigned long) addr); |
440 | |
441 | spin_lock_irqsave(&db->lock, flags); |
442 | |
443 | obj = lookup_object(addr, db); |
444 | if (obj) { |
445 | switch (obj->state) { |
446 | case ODEBUG_STATE_INIT: |
447 | case ODEBUG_STATE_INACTIVE: |
448 | case ODEBUG_STATE_ACTIVE: |
449 | obj->state = ODEBUG_STATE_INACTIVE; |
450 | break; |
451 | |
452 | case ODEBUG_STATE_DESTROYED: |
453 | debug_print_object(obj, "deactivate"); |
454 | break; |
455 | default: |
456 | break; |
457 | } |
458 | } else { |
459 | struct debug_obj o = { .object = addr, |
460 | .state = ODEBUG_STATE_NOTAVAILABLE, |
461 | .descr = descr }; |
462 | |
463 | debug_print_object(&o, "deactivate"); |
464 | } |
465 | |
466 | spin_unlock_irqrestore(&db->lock, flags); |
467 | } |
468 | |
469 | /** |
470 | * debug_object_destroy - debug checks when an object is destroyed |
471 | * @addr: address of the object |
472 | * @descr: pointer to an object specific debug description structure |
473 | */ |
474 | void debug_object_destroy(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_NONE: |
494 | case ODEBUG_STATE_INIT: |
495 | case ODEBUG_STATE_INACTIVE: |
496 | obj->state = ODEBUG_STATE_DESTROYED; |
497 | break; |
498 | case ODEBUG_STATE_ACTIVE: |
499 | debug_print_object(obj, "destroy"); |
500 | state = obj->state; |
501 | spin_unlock_irqrestore(&db->lock, flags); |
502 | debug_object_fixup(descr->fixup_destroy, addr, state); |
503 | return; |
504 | |
505 | case ODEBUG_STATE_DESTROYED: |
506 | debug_print_object(obj, "destroy"); |
507 | break; |
508 | default: |
509 | break; |
510 | } |
511 | out_unlock: |
512 | spin_unlock_irqrestore(&db->lock, flags); |
513 | } |
514 | |
515 | /** |
516 | * debug_object_free - debug checks when an object is freed |
517 | * @addr: address of the object |
518 | * @descr: pointer to an object specific debug description structure |
519 | */ |
520 | void debug_object_free(void *addr, struct debug_obj_descr *descr) |
521 | { |
522 | enum debug_obj_state state; |
523 | struct debug_bucket *db; |
524 | struct debug_obj *obj; |
525 | unsigned long flags; |
526 | |
527 | if (!debug_objects_enabled) |
528 | return; |
529 | |
530 | db = get_bucket((unsigned long) addr); |
531 | |
532 | spin_lock_irqsave(&db->lock, flags); |
533 | |
534 | obj = lookup_object(addr, db); |
535 | if (!obj) |
536 | goto out_unlock; |
537 | |
538 | switch (obj->state) { |
539 | case ODEBUG_STATE_ACTIVE: |
540 | debug_print_object(obj, "free"); |
541 | state = obj->state; |
542 | spin_unlock_irqrestore(&db->lock, flags); |
543 | debug_object_fixup(descr->fixup_free, addr, state); |
544 | return; |
545 | default: |
546 | hlist_del(&obj->node); |
547 | spin_unlock_irqrestore(&db->lock, flags); |
548 | free_object(obj); |
549 | return; |
550 | } |
551 | out_unlock: |
552 | spin_unlock_irqrestore(&db->lock, flags); |
553 | } |
554 | |
555 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
556 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) |
557 | { |
558 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; |
559 | struct hlist_node *node, *tmp; |
560 | HLIST_HEAD(freelist); |
561 | struct debug_obj_descr *descr; |
562 | enum debug_obj_state state; |
563 | struct debug_bucket *db; |
564 | struct debug_obj *obj; |
565 | int cnt; |
566 | |
567 | saddr = (unsigned long) address; |
568 | eaddr = saddr + size; |
569 | paddr = saddr & ODEBUG_CHUNK_MASK; |
570 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); |
571 | chunks >>= ODEBUG_CHUNK_SHIFT; |
572 | |
573 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { |
574 | db = get_bucket(paddr); |
575 | |
576 | repeat: |
577 | cnt = 0; |
578 | spin_lock_irqsave(&db->lock, flags); |
579 | hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) { |
580 | cnt++; |
581 | oaddr = (unsigned long) obj->object; |
582 | if (oaddr < saddr || oaddr >= eaddr) |
583 | continue; |
584 | |
585 | switch (obj->state) { |
586 | case ODEBUG_STATE_ACTIVE: |
587 | debug_print_object(obj, "free"); |
588 | descr = obj->descr; |
589 | state = obj->state; |
590 | spin_unlock_irqrestore(&db->lock, flags); |
591 | debug_object_fixup(descr->fixup_free, |
592 | (void *) oaddr, state); |
593 | goto repeat; |
594 | default: |
595 | hlist_del(&obj->node); |
596 | hlist_add_head(&obj->node, &freelist); |
597 | break; |
598 | } |
599 | } |
600 | spin_unlock_irqrestore(&db->lock, flags); |
601 | |
602 | /* Now free them */ |
603 | hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) { |
604 | hlist_del(&obj->node); |
605 | free_object(obj); |
606 | } |
607 | |
608 | if (cnt > debug_objects_maxchain) |
609 | debug_objects_maxchain = cnt; |
610 | } |
611 | } |
612 | |
613 | void debug_check_no_obj_freed(const void *address, unsigned long size) |
614 | { |
615 | if (debug_objects_enabled) |
616 | __debug_check_no_obj_freed(address, size); |
617 | } |
618 | #endif |
619 | |
620 | #ifdef CONFIG_DEBUG_FS |
621 | |
622 | static int debug_stats_show(struct seq_file *m, void *v) |
623 | { |
624 | seq_printf(m, "max_chain :%d\n", debug_objects_maxchain); |
625 | seq_printf(m, "warnings :%d\n", debug_objects_warnings); |
626 | seq_printf(m, "fixups :%d\n", debug_objects_fixups); |
627 | seq_printf(m, "pool_free :%d\n", obj_pool_free); |
628 | seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free); |
629 | seq_printf(m, "pool_used :%d\n", obj_pool_used); |
630 | seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used); |
631 | return 0; |
632 | } |
633 | |
634 | static int debug_stats_open(struct inode *inode, struct file *filp) |
635 | { |
636 | return single_open(filp, debug_stats_show, NULL); |
637 | } |
638 | |
639 | static const struct file_operations debug_stats_fops = { |
640 | .open = debug_stats_open, |
641 | .read = seq_read, |
642 | .llseek = seq_lseek, |
643 | .release = single_release, |
644 | }; |
645 | |
646 | static int __init debug_objects_init_debugfs(void) |
647 | { |
648 | struct dentry *dbgdir, *dbgstats; |
649 | |
650 | if (!debug_objects_enabled) |
651 | return 0; |
652 | |
653 | dbgdir = debugfs_create_dir("debug_objects", NULL); |
654 | if (!dbgdir) |
655 | return -ENOMEM; |
656 | |
657 | dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL, |
658 | &debug_stats_fops); |
659 | if (!dbgstats) |
660 | goto err; |
661 | |
662 | return 0; |
663 | |
664 | err: |
665 | debugfs_remove(dbgdir); |
666 | |
667 | return -ENOMEM; |
668 | } |
669 | __initcall(debug_objects_init_debugfs); |
670 | |
671 | #else |
672 | static inline void debug_objects_init_debugfs(void) { } |
673 | #endif |
674 | |
675 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST |
676 | |
677 | /* Random data structure for the self test */ |
678 | struct self_test { |
679 | unsigned long dummy1[6]; |
680 | int static_init; |
681 | unsigned long dummy2[3]; |
682 | }; |
683 | |
684 | static __initdata struct debug_obj_descr descr_type_test; |
685 | |
686 | /* |
687 | * fixup_init is called when: |
688 | * - an active object is initialized |
689 | */ |
690 | static int __init fixup_init(void *addr, enum debug_obj_state state) |
691 | { |
692 | struct self_test *obj = addr; |
693 | |
694 | switch (state) { |
695 | case ODEBUG_STATE_ACTIVE: |
696 | debug_object_deactivate(obj, &descr_type_test); |
697 | debug_object_init(obj, &descr_type_test); |
698 | return 1; |
699 | default: |
700 | return 0; |
701 | } |
702 | } |
703 | |
704 | /* |
705 | * fixup_activate is called when: |
706 | * - an active object is activated |
707 | * - an unknown object is activated (might be a statically initialized object) |
708 | */ |
709 | static int __init fixup_activate(void *addr, enum debug_obj_state state) |
710 | { |
711 | struct self_test *obj = addr; |
712 | |
713 | switch (state) { |
714 | case ODEBUG_STATE_NOTAVAILABLE: |
715 | if (obj->static_init == 1) { |
716 | debug_object_init(obj, &descr_type_test); |
717 | debug_object_activate(obj, &descr_type_test); |
718 | /* |
719 | * Real code should return 0 here ! This is |
720 | * not a fixup of some bad behaviour. We |
721 | * merily call the debug_init function to keep |
722 | * track of the object. |
723 | */ |
724 | return 1; |
725 | } else { |
726 | /* Real code needs to emit a warning here */ |
727 | } |
728 | return 0; |
729 | |
730 | case ODEBUG_STATE_ACTIVE: |
731 | debug_object_deactivate(obj, &descr_type_test); |
732 | debug_object_activate(obj, &descr_type_test); |
733 | return 1; |
734 | |
735 | default: |
736 | return 0; |
737 | } |
738 | } |
739 | |
740 | /* |
741 | * fixup_destroy is called when: |
742 | * - an active object is destroyed |
743 | */ |
744 | static int __init fixup_destroy(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_destroy(obj, &descr_type_test); |
752 | return 1; |
753 | default: |
754 | return 0; |
755 | } |
756 | } |
757 | |
758 | /* |
759 | * fixup_free is called when: |
760 | * - an active object is freed |
761 | */ |
762 | static int __init fixup_free(void *addr, enum debug_obj_state state) |
763 | { |
764 | struct self_test *obj = addr; |
765 | |
766 | switch (state) { |
767 | case ODEBUG_STATE_ACTIVE: |
768 | debug_object_deactivate(obj, &descr_type_test); |
769 | debug_object_free(obj, &descr_type_test); |
770 | return 1; |
771 | default: |
772 | return 0; |
773 | } |
774 | } |
775 | |
776 | static int |
777 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) |
778 | { |
779 | struct debug_bucket *db; |
780 | struct debug_obj *obj; |
781 | unsigned long flags; |
782 | int res = -EINVAL; |
783 | |
784 | db = get_bucket((unsigned long) addr); |
785 | |
786 | spin_lock_irqsave(&db->lock, flags); |
787 | |
788 | obj = lookup_object(addr, db); |
789 | if (!obj && state != ODEBUG_STATE_NONE) { |
790 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n"); |
791 | goto out; |
792 | } |
793 | if (obj && obj->state != state) { |
794 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n", |
795 | obj->state, state); |
796 | goto out; |
797 | } |
798 | if (fixups != debug_objects_fixups) { |
799 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n", |
800 | fixups, debug_objects_fixups); |
801 | goto out; |
802 | } |
803 | if (warnings != debug_objects_warnings) { |
804 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n", |
805 | warnings, debug_objects_warnings); |
806 | goto out; |
807 | } |
808 | res = 0; |
809 | out: |
810 | spin_unlock_irqrestore(&db->lock, flags); |
811 | if (res) |
812 | debug_objects_enabled = 0; |
813 | return res; |
814 | } |
815 | |
816 | static __initdata struct debug_obj_descr descr_type_test = { |
817 | .name = "selftest", |
818 | .fixup_init = fixup_init, |
819 | .fixup_activate = fixup_activate, |
820 | .fixup_destroy = fixup_destroy, |
821 | .fixup_free = fixup_free, |
822 | }; |
823 | |
824 | static __initdata struct self_test obj = { .static_init = 0 }; |
825 | |
826 | static void __init debug_objects_selftest(void) |
827 | { |
828 | int fixups, oldfixups, warnings, oldwarnings; |
829 | unsigned long flags; |
830 | |
831 | local_irq_save(flags); |
832 | |
833 | fixups = oldfixups = debug_objects_fixups; |
834 | warnings = oldwarnings = debug_objects_warnings; |
835 | descr_test = &descr_type_test; |
836 | |
837 | debug_object_init(&obj, &descr_type_test); |
838 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) |
839 | goto out; |
840 | debug_object_activate(&obj, &descr_type_test); |
841 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
842 | goto out; |
843 | debug_object_activate(&obj, &descr_type_test); |
844 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings)) |
845 | goto out; |
846 | debug_object_deactivate(&obj, &descr_type_test); |
847 | if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings)) |
848 | goto out; |
849 | debug_object_destroy(&obj, &descr_type_test); |
850 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings)) |
851 | goto out; |
852 | debug_object_init(&obj, &descr_type_test); |
853 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
854 | goto out; |
855 | debug_object_activate(&obj, &descr_type_test); |
856 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
857 | goto out; |
858 | debug_object_deactivate(&obj, &descr_type_test); |
859 | if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings)) |
860 | goto out; |
861 | debug_object_free(&obj, &descr_type_test); |
862 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) |
863 | goto out; |
864 | |
865 | obj.static_init = 1; |
866 | debug_object_activate(&obj, &descr_type_test); |
867 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings)) |
868 | goto out; |
869 | debug_object_init(&obj, &descr_type_test); |
870 | if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings)) |
871 | goto out; |
872 | debug_object_free(&obj, &descr_type_test); |
873 | if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings)) |
874 | goto out; |
875 | |
876 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
877 | debug_object_init(&obj, &descr_type_test); |
878 | if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings)) |
879 | goto out; |
880 | debug_object_activate(&obj, &descr_type_test); |
881 | if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings)) |
882 | goto out; |
883 | __debug_check_no_obj_freed(&obj, sizeof(obj)); |
884 | if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings)) |
885 | goto out; |
886 | #endif |
887 | printk(KERN_INFO "ODEBUG: selftest passed\n"); |
888 | |
889 | out: |
890 | debug_objects_fixups = oldfixups; |
891 | debug_objects_warnings = oldwarnings; |
892 | descr_test = NULL; |
893 | |
894 | local_irq_restore(flags); |
895 | } |
896 | #else |
897 | static inline void debug_objects_selftest(void) { } |
898 | #endif |
899 | |
900 | /* |
901 | * Called during early boot to initialize the hash buckets and link |
902 | * the static object pool objects into the poll list. After this call |
903 | * the object tracker is fully operational. |
904 | */ |
905 | void __init debug_objects_early_init(void) |
906 | { |
907 | int i; |
908 | |
909 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) |
910 | spin_lock_init(&obj_hash[i].lock); |
911 | |
912 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) |
913 | hlist_add_head(&obj_static_pool[i].node, &obj_pool); |
914 | } |
915 | |
916 | /* |
917 | * Convert the statically allocated objects to dynamic ones: |
918 | */ |
919 | static int debug_objects_replace_static_objects(void) |
920 | { |
921 | struct debug_bucket *db = obj_hash; |
922 | struct hlist_node *node, *tmp; |
923 | struct debug_obj *obj, *new; |
924 | HLIST_HEAD(objects); |
925 | int i, cnt = 0; |
926 | |
927 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) { |
928 | obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL); |
929 | if (!obj) |
930 | goto free; |
931 | hlist_add_head(&obj->node, &objects); |
932 | } |
933 | |
934 | /* |
935 | * When debug_objects_mem_init() is called we know that only |
936 | * one CPU is up, so disabling interrupts is enough |
937 | * protection. This avoids the lockdep hell of lock ordering. |
938 | */ |
939 | local_irq_disable(); |
940 | |
941 | /* Remove the statically allocated objects from the pool */ |
942 | hlist_for_each_entry_safe(obj, node, tmp, &obj_pool, node) |
943 | hlist_del(&obj->node); |
944 | /* Move the allocated objects to the pool */ |
945 | hlist_move_list(&objects, &obj_pool); |
946 | |
947 | /* Replace the active object references */ |
948 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
949 | hlist_move_list(&db->list, &objects); |
950 | |
951 | hlist_for_each_entry(obj, node, &objects, node) { |
952 | new = hlist_entry(obj_pool.first, typeof(*obj), node); |
953 | hlist_del(&new->node); |
954 | /* copy object data */ |
955 | *new = *obj; |
956 | hlist_add_head(&new->node, &db->list); |
957 | cnt++; |
958 | } |
959 | } |
960 | |
961 | printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt, |
962 | obj_pool_used); |
963 | local_irq_enable(); |
964 | return 0; |
965 | free: |
966 | hlist_for_each_entry_safe(obj, node, tmp, &objects, node) { |
967 | hlist_del(&obj->node); |
968 | kmem_cache_free(obj_cache, obj); |
969 | } |
970 | return -ENOMEM; |
971 | } |
972 | |
973 | /* |
974 | * Called after the kmem_caches are functional to setup a dedicated |
975 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag |
976 | * prevents that the debug code is called on kmem_cache_free() for the |
977 | * debug tracker objects to avoid recursive calls. |
978 | */ |
979 | void __init debug_objects_mem_init(void) |
980 | { |
981 | if (!debug_objects_enabled) |
982 | return; |
983 | |
984 | obj_cache = kmem_cache_create("debug_objects_cache", |
985 | sizeof (struct debug_obj), 0, |
986 | SLAB_DEBUG_OBJECTS, NULL); |
987 | |
988 | if (!obj_cache || debug_objects_replace_static_objects()) { |
989 | debug_objects_enabled = 0; |
990 | if (obj_cache) |
991 | kmem_cache_destroy(obj_cache); |
992 | printk(KERN_WARNING "ODEBUG: out of memory.\n"); |
993 | } else |
994 | debug_objects_selftest(); |
995 | } |
996 |
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