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 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
50
51 static struct debug_obj_descr *descr_test __read_mostly;
52
enable_object_debug(char * str)53 static int __init enable_object_debug(char *str)
54 {
55 debug_objects_enabled = 1;
56 return 0;
57 }
58 early_param("debug_objects", enable_object_debug);
59
60 static const char *obj_states[ODEBUG_STATE_MAX] = {
61 [ODEBUG_STATE_NONE] = "none",
62 [ODEBUG_STATE_INIT] = "initialized",
63 [ODEBUG_STATE_INACTIVE] = "inactive",
64 [ODEBUG_STATE_ACTIVE] = "active",
65 [ODEBUG_STATE_DESTROYED] = "destroyed",
66 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
67 };
68
fill_pool(void)69 static int fill_pool(void)
70 {
71 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
72 struct debug_obj *new;
73 unsigned long flags;
74
75 if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
76 return obj_pool_free;
77
78 if (unlikely(!obj_cache))
79 return obj_pool_free;
80
81 while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
82
83 new = kmem_cache_zalloc(obj_cache, gfp);
84 if (!new)
85 return obj_pool_free;
86
87 spin_lock_irqsave(&pool_lock, flags);
88 hlist_add_head(&new->node, &obj_pool);
89 obj_pool_free++;
90 spin_unlock_irqrestore(&pool_lock, flags);
91 }
92 return obj_pool_free;
93 }
94
95 /*
96 * Lookup an object in the hash bucket.
97 */
lookup_object(void * addr,struct debug_bucket * b)98 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
99 {
100 struct hlist_node *node;
101 struct debug_obj *obj;
102 int cnt = 0;
103
104 hlist_for_each_entry(obj, node, &b->list, node) {
105 cnt++;
106 if (obj->object == addr)
107 return obj;
108 }
109 if (cnt > debug_objects_maxchain)
110 debug_objects_maxchain = cnt;
111
112 return NULL;
113 }
114
115 /*
116 * Allocate a new object. If the pool is empty, switch off the debugger.
117 * Must be called with interrupts disabled.
118 */
119 static struct debug_obj *
alloc_object(void * addr,struct debug_bucket * b,struct debug_obj_descr * descr)120 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
121 {
122 struct debug_obj *obj = NULL;
123
124 spin_lock(&pool_lock);
125 if (obj_pool.first) {
126 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
127
128 obj->object = addr;
129 obj->descr = descr;
130 obj->state = ODEBUG_STATE_NONE;
131 hlist_del(&obj->node);
132
133 hlist_add_head(&obj->node, &b->list);
134
135 obj_pool_used++;
136 if (obj_pool_used > obj_pool_max_used)
137 obj_pool_max_used = obj_pool_used;
138
139 obj_pool_free--;
140 if (obj_pool_free < obj_pool_min_free)
141 obj_pool_min_free = obj_pool_free;
142 }
143 spin_unlock(&pool_lock);
144
145 return obj;
146 }
147
148 /*
149 * Put the object back into the pool or give it back to kmem_cache:
150 */
free_object(struct debug_obj * obj)151 static void free_object(struct debug_obj *obj)
152 {
153 unsigned long idx = (unsigned long)(obj - obj_static_pool);
154 unsigned long flags;
155
156 if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
157 spin_lock_irqsave(&pool_lock, flags);
158 hlist_add_head(&obj->node, &obj_pool);
159 obj_pool_free++;
160 obj_pool_used--;
161 spin_unlock_irqrestore(&pool_lock, flags);
162 } else {
163 spin_lock_irqsave(&pool_lock, flags);
164 obj_pool_used--;
165 spin_unlock_irqrestore(&pool_lock, flags);
166 kmem_cache_free(obj_cache, obj);
167 }
168 }
169
170 /*
171 * We run out of memory. That means we probably have tons of objects
172 * allocated.
173 */
debug_objects_oom(void)174 static void debug_objects_oom(void)
175 {
176 struct debug_bucket *db = obj_hash;
177 struct hlist_node *node, *tmp;
178 HLIST_HEAD(freelist);
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_move_list(&db->list, &freelist);
188 spin_unlock_irqrestore(&db->lock, flags);
189
190 /* Now free them */
191 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
192 hlist_del(&obj->node);
193 free_object(obj);
194 }
195 }
196 }
197
198 /*
199 * We use the pfn of the address for the hash. That way we can check
200 * for freed objects simply by checking the affected bucket.
201 */
get_bucket(unsigned long addr)202 static struct debug_bucket *get_bucket(unsigned long addr)
203 {
204 unsigned long hash;
205
206 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
207 return &obj_hash[hash];
208 }
209
debug_print_object(struct debug_obj * obj,char * msg)210 static void debug_print_object(struct debug_obj *obj, char *msg)
211 {
212 static int limit;
213
214 if (limit < 5 && obj->descr != descr_test) {
215 limit++;
216 WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
217 obj_states[obj->state], obj->descr->name);
218 }
219 debug_objects_warnings++;
220 }
221
222 /*
223 * Try to repair the damage, so we have a better chance to get useful
224 * debug output.
225 */
226 static void
debug_object_fixup(int (* fixup)(void * addr,enum debug_obj_state state),void * addr,enum debug_obj_state state)227 debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
228 void * addr, enum debug_obj_state state)
229 {
230 if (fixup)
231 debug_objects_fixups += fixup(addr, state);
232 }
233
debug_object_is_on_stack(void * addr,int onstack)234 static void debug_object_is_on_stack(void *addr, int onstack)
235 {
236 int is_on_stack;
237 static int limit;
238
239 if (limit > 4)
240 return;
241
242 is_on_stack = object_is_on_stack(addr);
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
__debug_object_init(void * addr,struct debug_obj_descr * descr,int onstack)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 fill_pool();
265
266 db = get_bucket((unsigned long) addr);
267
268 spin_lock_irqsave(&db->lock, flags);
269
270 obj = lookup_object(addr, db);
271 if (!obj) {
272 obj = alloc_object(addr, db, descr);
273 if (!obj) {
274 debug_objects_enabled = 0;
275 spin_unlock_irqrestore(&db->lock, flags);
276 debug_objects_oom();
277 return;
278 }
279 debug_object_is_on_stack(addr, onstack);
280 }
281
282 switch (obj->state) {
283 case ODEBUG_STATE_NONE:
284 case ODEBUG_STATE_INIT:
285 case ODEBUG_STATE_INACTIVE:
286 obj->state = ODEBUG_STATE_INIT;
287 break;
288
289 case ODEBUG_STATE_ACTIVE:
290 debug_print_object(obj, "init");
291 state = obj->state;
292 spin_unlock_irqrestore(&db->lock, flags);
293 debug_object_fixup(descr->fixup_init, addr, state);
294 return;
295
296 case ODEBUG_STATE_DESTROYED:
297 debug_print_object(obj, "init");
298 break;
299 default:
300 break;
301 }
302
303 spin_unlock_irqrestore(&db->lock, flags);
304 }
305
306 /**
307 * debug_object_init - debug checks when an object is initialized
308 * @addr: address of the object
309 * @descr: pointer to an object specific debug description structure
310 */
debug_object_init(void * addr,struct debug_obj_descr * descr)311 void debug_object_init(void *addr, struct debug_obj_descr *descr)
312 {
313 if (!debug_objects_enabled)
314 return;
315
316 __debug_object_init(addr, descr, 0);
317 }
318
319 /**
320 * debug_object_init_on_stack - debug checks when an object on stack is
321 * initialized
322 * @addr: address of the object
323 * @descr: pointer to an object specific debug description structure
324 */
debug_object_init_on_stack(void * addr,struct debug_obj_descr * descr)325 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
326 {
327 if (!debug_objects_enabled)
328 return;
329
330 __debug_object_init(addr, descr, 1);
331 }
332
333 /**
334 * debug_object_activate - debug checks when an object is activated
335 * @addr: address of the object
336 * @descr: pointer to an object specific debug description structure
337 */
debug_object_activate(void * addr,struct debug_obj_descr * descr)338 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
339 {
340 enum debug_obj_state state;
341 struct debug_bucket *db;
342 struct debug_obj *obj;
343 unsigned long flags;
344
345 if (!debug_objects_enabled)
346 return;
347
348 db = get_bucket((unsigned long) addr);
349
350 spin_lock_irqsave(&db->lock, flags);
351
352 obj = lookup_object(addr, db);
353 if (obj) {
354 switch (obj->state) {
355 case ODEBUG_STATE_INIT:
356 case ODEBUG_STATE_INACTIVE:
357 obj->state = ODEBUG_STATE_ACTIVE;
358 break;
359
360 case ODEBUG_STATE_ACTIVE:
361 debug_print_object(obj, "activate");
362 state = obj->state;
363 spin_unlock_irqrestore(&db->lock, flags);
364 debug_object_fixup(descr->fixup_activate, addr, state);
365 return;
366
367 case ODEBUG_STATE_DESTROYED:
368 debug_print_object(obj, "activate");
369 break;
370 default:
371 break;
372 }
373 spin_unlock_irqrestore(&db->lock, flags);
374 return;
375 }
376
377 spin_unlock_irqrestore(&db->lock, flags);
378 /*
379 * This happens when a static object is activated. We
380 * let the type specific code decide whether this is
381 * true or not.
382 */
383 debug_object_fixup(descr->fixup_activate, addr,
384 ODEBUG_STATE_NOTAVAILABLE);
385 }
386
387 /**
388 * debug_object_deactivate - debug checks when an object is deactivated
389 * @addr: address of the object
390 * @descr: pointer to an object specific debug description structure
391 */
debug_object_deactivate(void * addr,struct debug_obj_descr * descr)392 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
393 {
394 struct debug_bucket *db;
395 struct debug_obj *obj;
396 unsigned long flags;
397
398 if (!debug_objects_enabled)
399 return;
400
401 db = get_bucket((unsigned long) addr);
402
403 spin_lock_irqsave(&db->lock, flags);
404
405 obj = lookup_object(addr, db);
406 if (obj) {
407 switch (obj->state) {
408 case ODEBUG_STATE_INIT:
409 case ODEBUG_STATE_INACTIVE:
410 case ODEBUG_STATE_ACTIVE:
411 obj->state = ODEBUG_STATE_INACTIVE;
412 break;
413
414 case ODEBUG_STATE_DESTROYED:
415 debug_print_object(obj, "deactivate");
416 break;
417 default:
418 break;
419 }
420 } else {
421 struct debug_obj o = { .object = addr,
422 .state = ODEBUG_STATE_NOTAVAILABLE,
423 .descr = descr };
424
425 debug_print_object(&o, "deactivate");
426 }
427
428 spin_unlock_irqrestore(&db->lock, flags);
429 }
430
431 /**
432 * debug_object_destroy - debug checks when an object is destroyed
433 * @addr: address of the object
434 * @descr: pointer to an object specific debug description structure
435 */
debug_object_destroy(void * addr,struct debug_obj_descr * descr)436 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
437 {
438 enum debug_obj_state state;
439 struct debug_bucket *db;
440 struct debug_obj *obj;
441 unsigned long flags;
442
443 if (!debug_objects_enabled)
444 return;
445
446 db = get_bucket((unsigned long) addr);
447
448 spin_lock_irqsave(&db->lock, flags);
449
450 obj = lookup_object(addr, db);
451 if (!obj)
452 goto out_unlock;
453
454 switch (obj->state) {
455 case ODEBUG_STATE_NONE:
456 case ODEBUG_STATE_INIT:
457 case ODEBUG_STATE_INACTIVE:
458 obj->state = ODEBUG_STATE_DESTROYED;
459 break;
460 case ODEBUG_STATE_ACTIVE:
461 debug_print_object(obj, "destroy");
462 state = obj->state;
463 spin_unlock_irqrestore(&db->lock, flags);
464 debug_object_fixup(descr->fixup_destroy, addr, state);
465 return;
466
467 case ODEBUG_STATE_DESTROYED:
468 debug_print_object(obj, "destroy");
469 break;
470 default:
471 break;
472 }
473 out_unlock:
474 spin_unlock_irqrestore(&db->lock, flags);
475 }
476
477 /**
478 * debug_object_free - debug checks when an object is freed
479 * @addr: address of the object
480 * @descr: pointer to an object specific debug description structure
481 */
debug_object_free(void * addr,struct debug_obj_descr * descr)482 void debug_object_free(void *addr, struct debug_obj_descr *descr)
483 {
484 enum debug_obj_state state;
485 struct debug_bucket *db;
486 struct debug_obj *obj;
487 unsigned long flags;
488
489 if (!debug_objects_enabled)
490 return;
491
492 db = get_bucket((unsigned long) addr);
493
494 spin_lock_irqsave(&db->lock, flags);
495
496 obj = lookup_object(addr, db);
497 if (!obj)
498 goto out_unlock;
499
500 switch (obj->state) {
501 case ODEBUG_STATE_ACTIVE:
502 debug_print_object(obj, "free");
503 state = obj->state;
504 spin_unlock_irqrestore(&db->lock, flags);
505 debug_object_fixup(descr->fixup_free, addr, state);
506 return;
507 default:
508 hlist_del(&obj->node);
509 spin_unlock_irqrestore(&db->lock, flags);
510 free_object(obj);
511 return;
512 }
513 out_unlock:
514 spin_unlock_irqrestore(&db->lock, flags);
515 }
516
517 #ifdef CONFIG_DEBUG_OBJECTS_FREE
__debug_check_no_obj_freed(const void * address,unsigned long size)518 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
519 {
520 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
521 struct hlist_node *node, *tmp;
522 HLIST_HEAD(freelist);
523 struct debug_obj_descr *descr;
524 enum debug_obj_state state;
525 struct debug_bucket *db;
526 struct debug_obj *obj;
527 int cnt;
528
529 saddr = (unsigned long) address;
530 eaddr = saddr + size;
531 paddr = saddr & ODEBUG_CHUNK_MASK;
532 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
533 chunks >>= ODEBUG_CHUNK_SHIFT;
534
535 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
536 db = get_bucket(paddr);
537
538 repeat:
539 cnt = 0;
540 spin_lock_irqsave(&db->lock, flags);
541 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
542 cnt++;
543 oaddr = (unsigned long) obj->object;
544 if (oaddr < saddr || oaddr >= eaddr)
545 continue;
546
547 switch (obj->state) {
548 case ODEBUG_STATE_ACTIVE:
549 debug_print_object(obj, "free");
550 descr = obj->descr;
551 state = obj->state;
552 spin_unlock_irqrestore(&db->lock, flags);
553 debug_object_fixup(descr->fixup_free,
554 (void *) oaddr, state);
555 goto repeat;
556 default:
557 hlist_del(&obj->node);
558 hlist_add_head(&obj->node, &freelist);
559 break;
560 }
561 }
562 spin_unlock_irqrestore(&db->lock, flags);
563
564 /* Now free them */
565 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
566 hlist_del(&obj->node);
567 free_object(obj);
568 }
569
570 if (cnt > debug_objects_maxchain)
571 debug_objects_maxchain = cnt;
572 }
573 }
574
debug_check_no_obj_freed(const void * address,unsigned long size)575 void debug_check_no_obj_freed(const void *address, unsigned long size)
576 {
577 if (debug_objects_enabled)
578 __debug_check_no_obj_freed(address, size);
579 }
580 #endif
581
582 #ifdef CONFIG_DEBUG_FS
583
debug_stats_show(struct seq_file * m,void * v)584 static int debug_stats_show(struct seq_file *m, void *v)
585 {
586 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
587 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
588 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
589 seq_printf(m, "pool_free :%d\n", obj_pool_free);
590 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
591 seq_printf(m, "pool_used :%d\n", obj_pool_used);
592 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
593 return 0;
594 }
595
debug_stats_open(struct inode * inode,struct file * filp)596 static int debug_stats_open(struct inode *inode, struct file *filp)
597 {
598 return single_open(filp, debug_stats_show, NULL);
599 }
600
601 static const struct file_operations debug_stats_fops = {
602 .open = debug_stats_open,
603 .read = seq_read,
604 .llseek = seq_lseek,
605 .release = single_release,
606 };
607
debug_objects_init_debugfs(void)608 static int __init debug_objects_init_debugfs(void)
609 {
610 struct dentry *dbgdir, *dbgstats;
611
612 if (!debug_objects_enabled)
613 return 0;
614
615 dbgdir = debugfs_create_dir("debug_objects", NULL);
616 if (!dbgdir)
617 return -ENOMEM;
618
619 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
620 &debug_stats_fops);
621 if (!dbgstats)
622 goto err;
623
624 return 0;
625
626 err:
627 debugfs_remove(dbgdir);
628
629 return -ENOMEM;
630 }
631 __initcall(debug_objects_init_debugfs);
632
633 #else
debug_objects_init_debugfs(void)634 static inline void debug_objects_init_debugfs(void) { }
635 #endif
636
637 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
638
639 /* Random data structure for the self test */
640 struct self_test {
641 unsigned long dummy1[6];
642 int static_init;
643 unsigned long dummy2[3];
644 };
645
646 static __initdata struct debug_obj_descr descr_type_test;
647
648 /*
649 * fixup_init is called when:
650 * - an active object is initialized
651 */
fixup_init(void * addr,enum debug_obj_state state)652 static int __init fixup_init(void *addr, enum debug_obj_state state)
653 {
654 struct self_test *obj = addr;
655
656 switch (state) {
657 case ODEBUG_STATE_ACTIVE:
658 debug_object_deactivate(obj, &descr_type_test);
659 debug_object_init(obj, &descr_type_test);
660 return 1;
661 default:
662 return 0;
663 }
664 }
665
666 /*
667 * fixup_activate is called when:
668 * - an active object is activated
669 * - an unknown object is activated (might be a statically initialized object)
670 */
fixup_activate(void * addr,enum debug_obj_state state)671 static int __init fixup_activate(void *addr, enum debug_obj_state state)
672 {
673 struct self_test *obj = addr;
674
675 switch (state) {
676 case ODEBUG_STATE_NOTAVAILABLE:
677 if (obj->static_init == 1) {
678 debug_object_init(obj, &descr_type_test);
679 debug_object_activate(obj, &descr_type_test);
680 /*
681 * Real code should return 0 here ! This is
682 * not a fixup of some bad behaviour. We
683 * merily call the debug_init function to keep
684 * track of the object.
685 */
686 return 1;
687 } else {
688 /* Real code needs to emit a warning here */
689 }
690 return 0;
691
692 case ODEBUG_STATE_ACTIVE:
693 debug_object_deactivate(obj, &descr_type_test);
694 debug_object_activate(obj, &descr_type_test);
695 return 1;
696
697 default:
698 return 0;
699 }
700 }
701
702 /*
703 * fixup_destroy is called when:
704 * - an active object is destroyed
705 */
fixup_destroy(void * addr,enum debug_obj_state state)706 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
707 {
708 struct self_test *obj = addr;
709
710 switch (state) {
711 case ODEBUG_STATE_ACTIVE:
712 debug_object_deactivate(obj, &descr_type_test);
713 debug_object_destroy(obj, &descr_type_test);
714 return 1;
715 default:
716 return 0;
717 }
718 }
719
720 /*
721 * fixup_free is called when:
722 * - an active object is freed
723 */
fixup_free(void * addr,enum debug_obj_state state)724 static int __init fixup_free(void *addr, enum debug_obj_state state)
725 {
726 struct self_test *obj = addr;
727
728 switch (state) {
729 case ODEBUG_STATE_ACTIVE:
730 debug_object_deactivate(obj, &descr_type_test);
731 debug_object_free(obj, &descr_type_test);
732 return 1;
733 default:
734 return 0;
735 }
736 }
737
738 static int
check_results(void * addr,enum debug_obj_state state,int fixups,int warnings)739 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
740 {
741 struct debug_bucket *db;
742 struct debug_obj *obj;
743 unsigned long flags;
744 int res = -EINVAL;
745
746 db = get_bucket((unsigned long) addr);
747
748 spin_lock_irqsave(&db->lock, flags);
749
750 obj = lookup_object(addr, db);
751 if (!obj && state != ODEBUG_STATE_NONE) {
752 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
753 goto out;
754 }
755 if (obj && obj->state != state) {
756 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
757 obj->state, state);
758 goto out;
759 }
760 if (fixups != debug_objects_fixups) {
761 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
762 fixups, debug_objects_fixups);
763 goto out;
764 }
765 if (warnings != debug_objects_warnings) {
766 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
767 warnings, debug_objects_warnings);
768 goto out;
769 }
770 res = 0;
771 out:
772 spin_unlock_irqrestore(&db->lock, flags);
773 if (res)
774 debug_objects_enabled = 0;
775 return res;
776 }
777
778 static __initdata struct debug_obj_descr descr_type_test = {
779 .name = "selftest",
780 .fixup_init = fixup_init,
781 .fixup_activate = fixup_activate,
782 .fixup_destroy = fixup_destroy,
783 .fixup_free = fixup_free,
784 };
785
786 static __initdata struct self_test obj = { .static_init = 0 };
787
debug_objects_selftest(void)788 static void __init debug_objects_selftest(void)
789 {
790 int fixups, oldfixups, warnings, oldwarnings;
791 unsigned long flags;
792
793 local_irq_save(flags);
794
795 fixups = oldfixups = debug_objects_fixups;
796 warnings = oldwarnings = debug_objects_warnings;
797 descr_test = &descr_type_test;
798
799 debug_object_init(&obj, &descr_type_test);
800 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
801 goto out;
802 debug_object_activate(&obj, &descr_type_test);
803 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
804 goto out;
805 debug_object_activate(&obj, &descr_type_test);
806 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
807 goto out;
808 debug_object_deactivate(&obj, &descr_type_test);
809 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
810 goto out;
811 debug_object_destroy(&obj, &descr_type_test);
812 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
813 goto out;
814 debug_object_init(&obj, &descr_type_test);
815 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
816 goto out;
817 debug_object_activate(&obj, &descr_type_test);
818 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
819 goto out;
820 debug_object_deactivate(&obj, &descr_type_test);
821 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
822 goto out;
823 debug_object_free(&obj, &descr_type_test);
824 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
825 goto out;
826
827 obj.static_init = 1;
828 debug_object_activate(&obj, &descr_type_test);
829 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
830 goto out;
831 debug_object_init(&obj, &descr_type_test);
832 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
833 goto out;
834 debug_object_free(&obj, &descr_type_test);
835 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
836 goto out;
837
838 #ifdef CONFIG_DEBUG_OBJECTS_FREE
839 debug_object_init(&obj, &descr_type_test);
840 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
841 goto out;
842 debug_object_activate(&obj, &descr_type_test);
843 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
844 goto out;
845 __debug_check_no_obj_freed(&obj, sizeof(obj));
846 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
847 goto out;
848 #endif
849 printk(KERN_INFO "ODEBUG: selftest passed\n");
850
851 out:
852 debug_objects_fixups = oldfixups;
853 debug_objects_warnings = oldwarnings;
854 descr_test = NULL;
855
856 local_irq_restore(flags);
857 }
858 #else
debug_objects_selftest(void)859 static inline void debug_objects_selftest(void) { }
860 #endif
861
862 /*
863 * Called during early boot to initialize the hash buckets and link
864 * the static object pool objects into the poll list. After this call
865 * the object tracker is fully operational.
866 */
debug_objects_early_init(void)867 void __init debug_objects_early_init(void)
868 {
869 int i;
870
871 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
872 spin_lock_init(&obj_hash[i].lock);
873
874 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
875 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
876 }
877
878 /*
879 * Called after the kmem_caches are functional to setup a dedicated
880 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
881 * prevents that the debug code is called on kmem_cache_free() for the
882 * debug tracker objects to avoid recursive calls.
883 */
debug_objects_mem_init(void)884 void __init debug_objects_mem_init(void)
885 {
886 if (!debug_objects_enabled)
887 return;
888
889 obj_cache = kmem_cache_create("debug_objects_cache",
890 sizeof (struct debug_obj), 0,
891 SLAB_DEBUG_OBJECTS, NULL);
892
893 if (!obj_cache)
894 debug_objects_enabled = 0;
895 else
896 debug_objects_selftest();
897 }
898