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x86/apic: Remove the duplicated tracing versions of interrupts
[linux-stable.git] / lib / debugobjects.c
blob17afb043016133f880c3c64b696b5093f28dc52e
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
11 #define pr_fmt(fmt) "ODEBUG: " fmt
12
13 #include <linux/debugobjects.h>
14 #include <linux/interrupt.h>
15 #include <linux/sched.h>
16 #include <linux/sched/task_stack.h>
17 #include <linux/seq_file.h>
18 #include <linux/debugfs.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21
22 #define ODEBUG_HASH_BITS 14
23 #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
24
25 #define ODEBUG_POOL_SIZE 1024
26 #define ODEBUG_POOL_MIN_LEVEL 256
27
28 #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
29 #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
30 #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
31
32 struct debug_bucket {
33 struct hlist_head list;
34 raw_spinlock_t lock;
35 };
36
37 static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
38
39 static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
40
41 static DEFINE_RAW_SPINLOCK(pool_lock);
42
43 static HLIST_HEAD(obj_pool);
44
45 static int obj_pool_min_free = ODEBUG_POOL_SIZE;
46 static int obj_pool_free = ODEBUG_POOL_SIZE;
47 static int obj_pool_used;
48 static int obj_pool_max_used;
49 static struct kmem_cache *obj_cache;
50
51 static int debug_objects_maxchain __read_mostly;
52 static int debug_objects_fixups __read_mostly;
53 static int debug_objects_warnings __read_mostly;
54 static int debug_objects_enabled __read_mostly
55 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
56 static int debug_objects_pool_size __read_mostly
57 = ODEBUG_POOL_SIZE;
58 static int debug_objects_pool_min_level __read_mostly
59 = ODEBUG_POOL_MIN_LEVEL;
60 static struct debug_obj_descr *descr_test __read_mostly;
61
62 /*
63 * Track numbers of kmem_cache_alloc()/free() calls done.
64 */
65 static int debug_objects_allocated;
66 static int debug_objects_freed;
67
68 static void free_obj_work(struct work_struct *work);
69 static DECLARE_WORK(debug_obj_work, free_obj_work);
70
71 static int __init enable_object_debug(char *str)
72 {
73 debug_objects_enabled = 1;
74 return 0;
75 }
76
77 static int __init disable_object_debug(char *str)
78 {
79 debug_objects_enabled = 0;
80 return 0;
81 }
82
83 early_param("debug_objects", enable_object_debug);
84 early_param("no_debug_objects", disable_object_debug);
85
86 static const char *obj_states[ODEBUG_STATE_MAX] = {
87 [ODEBUG_STATE_NONE] = "none",
88 [ODEBUG_STATE_INIT] = "initialized",
89 [ODEBUG_STATE_INACTIVE] = "inactive",
90 [ODEBUG_STATE_ACTIVE] = "active",
91 [ODEBUG_STATE_DESTROYED] = "destroyed",
92 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
93 };
94
95 static void fill_pool(void)
96 {
97 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
98 struct debug_obj *new;
99 unsigned long flags;
100
101 if (likely(obj_pool_free >= debug_objects_pool_min_level))
102 return;
103
104 if (unlikely(!obj_cache))
105 return;
106
107 while (obj_pool_free < debug_objects_pool_min_level) {
108
109 new = kmem_cache_zalloc(obj_cache, gfp);
110 if (!new)
111 return;
112
113 raw_spin_lock_irqsave(&pool_lock, flags);
114 hlist_add_head(&new->node, &obj_pool);
115 debug_objects_allocated++;
116 obj_pool_free++;
117 raw_spin_unlock_irqrestore(&pool_lock, flags);
118 }
119 }
120
121 /*
122 * Lookup an object in the hash bucket.
123 */
124 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
125 {
126 struct debug_obj *obj;
127 int cnt = 0;
128
129 hlist_for_each_entry(obj, &b->list, node) {
130 cnt++;
131 if (obj->object == addr)
132 return obj;
133 }
134 if (cnt > debug_objects_maxchain)
135 debug_objects_maxchain = cnt;
136
137 return NULL;
138 }
139
140 /*
141 * Allocate a new object. If the pool is empty, switch off the debugger.
142 * Must be called with interrupts disabled.
143 */
144 static struct debug_obj *
145 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
146 {
147 struct debug_obj *obj = NULL;
148
149 raw_spin_lock(&pool_lock);
150 if (obj_pool.first) {
151 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
152
153 obj->object = addr;
154 obj->descr = descr;
155 obj->state = ODEBUG_STATE_NONE;
156 obj->astate = 0;
157 hlist_del(&obj->node);
158
159 hlist_add_head(&obj->node, &b->list);
160
161 obj_pool_used++;
162 if (obj_pool_used > obj_pool_max_used)
163 obj_pool_max_used = obj_pool_used;
164
165 obj_pool_free--;
166 if (obj_pool_free < obj_pool_min_free)
167 obj_pool_min_free = obj_pool_free;
168 }
169 raw_spin_unlock(&pool_lock);
170
171 return obj;
172 }
173
174 /*
175 * workqueue function to free objects.
176 *
177 * To reduce contention on the global pool_lock, the actual freeing of
178 * debug objects will be delayed if the pool_lock is busy. We also free
179 * the objects in a batch of 4 for each lock/unlock cycle.
180 */
181 #define ODEBUG_FREE_BATCH 4
182
183 static void free_obj_work(struct work_struct *work)
184 {
185 struct debug_obj *objs[ODEBUG_FREE_BATCH];
186 unsigned long flags;
187 int i;
188
189 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
190 return;
191 while (obj_pool_free >= debug_objects_pool_size + ODEBUG_FREE_BATCH) {
192 for (i = 0; i < ODEBUG_FREE_BATCH; i++) {
193 objs[i] = hlist_entry(obj_pool.first,
194 typeof(*objs[0]), node);
195 hlist_del(&objs[i]->node);
196 }
197
198 obj_pool_free -= ODEBUG_FREE_BATCH;
199 debug_objects_freed += ODEBUG_FREE_BATCH;
200 /*
201 * We release pool_lock across kmem_cache_free() to
202 * avoid contention on pool_lock.
203 */
204 raw_spin_unlock_irqrestore(&pool_lock, flags);
205 for (i = 0; i < ODEBUG_FREE_BATCH; i++)
206 kmem_cache_free(obj_cache, objs[i]);
207 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
208 return;
209 }
210 raw_spin_unlock_irqrestore(&pool_lock, flags);
211 }
212
213 /*
214 * Put the object back into the pool and schedule work to free objects
215 * if necessary.
216 */
217 static void free_object(struct debug_obj *obj)
218 {
219 unsigned long flags;
220 int sched = 0;
221
222 raw_spin_lock_irqsave(&pool_lock, flags);
223 /*
224 * schedule work when the pool is filled and the cache is
225 * initialized:
226 */
227 if (obj_pool_free > debug_objects_pool_size && obj_cache)
228 sched = 1;
229 hlist_add_head(&obj->node, &obj_pool);
230 obj_pool_free++;
231 obj_pool_used--;
232 raw_spin_unlock_irqrestore(&pool_lock, flags);
233 if (sched)
234 schedule_work(&debug_obj_work);
235 }
236
237 /*
238 * We run out of memory. That means we probably have tons of objects
239 * allocated.
240 */
241 static void debug_objects_oom(void)
242 {
243 struct debug_bucket *db = obj_hash;
244 struct hlist_node *tmp;
245 HLIST_HEAD(freelist);
246 struct debug_obj *obj;
247 unsigned long flags;
248 int i;
249
250 pr_warn("Out of memory. ODEBUG disabled\n");
251
252 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
253 raw_spin_lock_irqsave(&db->lock, flags);
254 hlist_move_list(&db->list, &freelist);
255 raw_spin_unlock_irqrestore(&db->lock, flags);
256
257 /* Now free them */
258 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
259 hlist_del(&obj->node);
260 free_object(obj);
261 }
262 }
263 }
264
265 /*
266 * We use the pfn of the address for the hash. That way we can check
267 * for freed objects simply by checking the affected bucket.
268 */
269 static struct debug_bucket *get_bucket(unsigned long addr)
270 {
271 unsigned long hash;
272
273 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
274 return &obj_hash[hash];
275 }
276
277 static void debug_print_object(struct debug_obj *obj, char *msg)
278 {
279 struct debug_obj_descr *descr = obj->descr;
280 static int limit;
281
282 if (limit < 5 && descr != descr_test) {
283 void *hint = descr->debug_hint ?
284 descr->debug_hint(obj->object) : NULL;
285 limit++;
286 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
287 "object type: %s hint: %pS\n",
288 msg, obj_states[obj->state], obj->astate,
289 descr->name, hint);
290 }
291 debug_objects_warnings++;
292 }
293
294 /*
295 * Try to repair the damage, so we have a better chance to get useful
296 * debug output.
297 */
298 static bool
299 debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
300 void * addr, enum debug_obj_state state)
301 {
302 if (fixup && fixup(addr, state)) {
303 debug_objects_fixups++;
304 return true;
305 }
306 return false;
307 }
308
309 static void debug_object_is_on_stack(void *addr, int onstack)
310 {
311 int is_on_stack;
312 static int limit;
313
314 if (limit > 4)
315 return;
316
317 is_on_stack = object_is_on_stack(addr);
318 if (is_on_stack == onstack)
319 return;
320
321 limit++;
322 if (is_on_stack)
323 pr_warn("object is on stack, but not annotated\n");
324 else
325 pr_warn("object is not on stack, but annotated\n");
326 WARN_ON(1);
327 }
328
329 static void
330 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
331 {
332 enum debug_obj_state state;
333 struct debug_bucket *db;
334 struct debug_obj *obj;
335 unsigned long flags;
336
337 fill_pool();
338
339 db = get_bucket((unsigned long) addr);
340
341 raw_spin_lock_irqsave(&db->lock, flags);
342
343 obj = lookup_object(addr, db);
344 if (!obj) {
345 obj = alloc_object(addr, db, descr);
346 if (!obj) {
347 debug_objects_enabled = 0;
348 raw_spin_unlock_irqrestore(&db->lock, flags);
349 debug_objects_oom();
350 return;
351 }
352 debug_object_is_on_stack(addr, onstack);
353 }
354
355 switch (obj->state) {
356 case ODEBUG_STATE_NONE:
357 case ODEBUG_STATE_INIT:
358 case ODEBUG_STATE_INACTIVE:
359 obj->state = ODEBUG_STATE_INIT;
360 break;
361
362 case ODEBUG_STATE_ACTIVE:
363 debug_print_object(obj, "init");
364 state = obj->state;
365 raw_spin_unlock_irqrestore(&db->lock, flags);
366 debug_object_fixup(descr->fixup_init, addr, state);
367 return;
368
369 case ODEBUG_STATE_DESTROYED:
370 debug_print_object(obj, "init");
371 break;
372 default:
373 break;
374 }
375
376 raw_spin_unlock_irqrestore(&db->lock, flags);
377 }
378
379 /**
380 * debug_object_init - debug checks when an object is initialized
381 * @addr: address of the object
382 * @descr: pointer to an object specific debug description structure
383 */
384 void debug_object_init(void *addr, struct debug_obj_descr *descr)
385 {
386 if (!debug_objects_enabled)
387 return;
388
389 __debug_object_init(addr, descr, 0);
390 }
391 EXPORT_SYMBOL_GPL(debug_object_init);
392
393 /**
394 * debug_object_init_on_stack - debug checks when an object on stack is
395 * initialized
396 * @addr: address of the object
397 * @descr: pointer to an object specific debug description structure
398 */
399 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
400 {
401 if (!debug_objects_enabled)
402 return;
403
404 __debug_object_init(addr, descr, 1);
405 }
406 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
407
408 /**
409 * debug_object_activate - debug checks when an object is activated
410 * @addr: address of the object
411 * @descr: pointer to an object specific debug description structure
412 * Returns 0 for success, -EINVAL for check failed.
413 */
414 int debug_object_activate(void *addr, struct debug_obj_descr *descr)
415 {
416 enum debug_obj_state state;
417 struct debug_bucket *db;
418 struct debug_obj *obj;
419 unsigned long flags;
420 int ret;
421 struct debug_obj o = { .object = addr,
422 .state = ODEBUG_STATE_NOTAVAILABLE,
423 .descr = descr };
424
425 if (!debug_objects_enabled)
426 return 0;
427
428 db = get_bucket((unsigned long) addr);
429
430 raw_spin_lock_irqsave(&db->lock, flags);
431
432 obj = lookup_object(addr, db);
433 if (obj) {
434 switch (obj->state) {
435 case ODEBUG_STATE_INIT:
436 case ODEBUG_STATE_INACTIVE:
437 obj->state = ODEBUG_STATE_ACTIVE;
438 ret = 0;
439 break;
440
441 case ODEBUG_STATE_ACTIVE:
442 debug_print_object(obj, "activate");
443 state = obj->state;
444 raw_spin_unlock_irqrestore(&db->lock, flags);
445 ret = debug_object_fixup(descr->fixup_activate, addr, state);
446 return ret ? 0 : -EINVAL;
447
448 case ODEBUG_STATE_DESTROYED:
449 debug_print_object(obj, "activate");
450 ret = -EINVAL;
451 break;
452 default:
453 ret = 0;
454 break;
455 }
456 raw_spin_unlock_irqrestore(&db->lock, flags);
457 return ret;
458 }
459
460 raw_spin_unlock_irqrestore(&db->lock, flags);
461 /*
462 * We are here when a static object is activated. We
463 * let the type specific code confirm whether this is
464 * true or not. if true, we just make sure that the
465 * static object is tracked in the object tracker. If
466 * not, this must be a bug, so we try to fix it up.
467 */
468 if (descr->is_static_object && descr->is_static_object(addr)) {
469 /* track this static object */
470 debug_object_init(addr, descr);
471 debug_object_activate(addr, descr);
472 } else {
473 debug_print_object(&o, "activate");
474 ret = debug_object_fixup(descr->fixup_activate, addr,
475 ODEBUG_STATE_NOTAVAILABLE);
476 return ret ? 0 : -EINVAL;
477 }
478 return 0;
479 }
480 EXPORT_SYMBOL_GPL(debug_object_activate);
481
482 /**
483 * debug_object_deactivate - debug checks when an object is deactivated
484 * @addr: address of the object
485 * @descr: pointer to an object specific debug description structure
486 */
487 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
488 {
489 struct debug_bucket *db;
490 struct debug_obj *obj;
491 unsigned long flags;
492
493 if (!debug_objects_enabled)
494 return;
495
496 db = get_bucket((unsigned long) addr);
497
498 raw_spin_lock_irqsave(&db->lock, flags);
499
500 obj = lookup_object(addr, db);
501 if (obj) {
502 switch (obj->state) {
503 case ODEBUG_STATE_INIT:
504 case ODEBUG_STATE_INACTIVE:
505 case ODEBUG_STATE_ACTIVE:
506 if (!obj->astate)
507 obj->state = ODEBUG_STATE_INACTIVE;
508 else
509 debug_print_object(obj, "deactivate");
510 break;
511
512 case ODEBUG_STATE_DESTROYED:
513 debug_print_object(obj, "deactivate");
514 break;
515 default:
516 break;
517 }
518 } else {
519 struct debug_obj o = { .object = addr,
520 .state = ODEBUG_STATE_NOTAVAILABLE,
521 .descr = descr };
522
523 debug_print_object(&o, "deactivate");
524 }
525
526 raw_spin_unlock_irqrestore(&db->lock, flags);
527 }
528 EXPORT_SYMBOL_GPL(debug_object_deactivate);
529
530 /**
531 * debug_object_destroy - debug checks when an object is destroyed
532 * @addr: address of the object
533 * @descr: pointer to an object specific debug description structure
534 */
535 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
536 {
537 enum debug_obj_state state;
538 struct debug_bucket *db;
539 struct debug_obj *obj;
540 unsigned long flags;
541
542 if (!debug_objects_enabled)
543 return;
544
545 db = get_bucket((unsigned long) addr);
546
547 raw_spin_lock_irqsave(&db->lock, flags);
548
549 obj = lookup_object(addr, db);
550 if (!obj)
551 goto out_unlock;
552
553 switch (obj->state) {
554 case ODEBUG_STATE_NONE:
555 case ODEBUG_STATE_INIT:
556 case ODEBUG_STATE_INACTIVE:
557 obj->state = ODEBUG_STATE_DESTROYED;
558 break;
559 case ODEBUG_STATE_ACTIVE:
560 debug_print_object(obj, "destroy");
561 state = obj->state;
562 raw_spin_unlock_irqrestore(&db->lock, flags);
563 debug_object_fixup(descr->fixup_destroy, addr, state);
564 return;
565
566 case ODEBUG_STATE_DESTROYED:
567 debug_print_object(obj, "destroy");
568 break;
569 default:
570 break;
571 }
572 out_unlock:
573 raw_spin_unlock_irqrestore(&db->lock, flags);
574 }
575 EXPORT_SYMBOL_GPL(debug_object_destroy);
576
577 /**
578 * debug_object_free - debug checks when an object is freed
579 * @addr: address of the object
580 * @descr: pointer to an object specific debug description structure
581 */
582 void debug_object_free(void *addr, struct debug_obj_descr *descr)
583 {
584 enum debug_obj_state state;
585 struct debug_bucket *db;
586 struct debug_obj *obj;
587 unsigned long flags;
588
589 if (!debug_objects_enabled)
590 return;
591
592 db = get_bucket((unsigned long) addr);
593
594 raw_spin_lock_irqsave(&db->lock, flags);
595
596 obj = lookup_object(addr, db);
597 if (!obj)
598 goto out_unlock;
599
600 switch (obj->state) {
601 case ODEBUG_STATE_ACTIVE:
602 debug_print_object(obj, "free");
603 state = obj->state;
604 raw_spin_unlock_irqrestore(&db->lock, flags);
605 debug_object_fixup(descr->fixup_free, addr, state);
606 return;
607 default:
608 hlist_del(&obj->node);
609 raw_spin_unlock_irqrestore(&db->lock, flags);
610 free_object(obj);
611 return;
612 }
613 out_unlock:
614 raw_spin_unlock_irqrestore(&db->lock, flags);
615 }
616 EXPORT_SYMBOL_GPL(debug_object_free);
617
618 /**
619 * debug_object_assert_init - debug checks when object should be init-ed
620 * @addr: address of the object
621 * @descr: pointer to an object specific debug description structure
622 */
623 void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
624 {
625 struct debug_bucket *db;
626 struct debug_obj *obj;
627 unsigned long flags;
628
629 if (!debug_objects_enabled)
630 return;
631
632 db = get_bucket((unsigned long) addr);
633
634 raw_spin_lock_irqsave(&db->lock, flags);
635
636 obj = lookup_object(addr, db);
637 if (!obj) {
638 struct debug_obj o = { .object = addr,
639 .state = ODEBUG_STATE_NOTAVAILABLE,
640 .descr = descr };
641
642 raw_spin_unlock_irqrestore(&db->lock, flags);
643 /*
644 * Maybe the object is static, and we let the type specific
645 * code confirm. Track this static object if true, else invoke
646 * fixup.
647 */
648 if (descr->is_static_object && descr->is_static_object(addr)) {
649 /* Track this static object */
650 debug_object_init(addr, descr);
651 } else {
652 debug_print_object(&o, "assert_init");
653 debug_object_fixup(descr->fixup_assert_init, addr,
654 ODEBUG_STATE_NOTAVAILABLE);
655 }
656 return;
657 }
658
659 raw_spin_unlock_irqrestore(&db->lock, flags);
660 }
661 EXPORT_SYMBOL_GPL(debug_object_assert_init);
662
663 /**
664 * debug_object_active_state - debug checks object usage state machine
665 * @addr: address of the object
666 * @descr: pointer to an object specific debug description structure
667 * @expect: expected state
668 * @next: state to move to if expected state is found
669 */
670 void
671 debug_object_active_state(void *addr, struct debug_obj_descr *descr,
672 unsigned int expect, unsigned int next)
673 {
674 struct debug_bucket *db;
675 struct debug_obj *obj;
676 unsigned long flags;
677
678 if (!debug_objects_enabled)
679 return;
680
681 db = get_bucket((unsigned long) addr);
682
683 raw_spin_lock_irqsave(&db->lock, flags);
684
685 obj = lookup_object(addr, db);
686 if (obj) {
687 switch (obj->state) {
688 case ODEBUG_STATE_ACTIVE:
689 if (obj->astate == expect)
690 obj->astate = next;
691 else
692 debug_print_object(obj, "active_state");
693 break;
694
695 default:
696 debug_print_object(obj, "active_state");
697 break;
698 }
699 } else {
700 struct debug_obj o = { .object = addr,
701 .state = ODEBUG_STATE_NOTAVAILABLE,
702 .descr = descr };
703
704 debug_print_object(&o, "active_state");
705 }
706
707 raw_spin_unlock_irqrestore(&db->lock, flags);
708 }
709 EXPORT_SYMBOL_GPL(debug_object_active_state);
710
711 #ifdef CONFIG_DEBUG_OBJECTS_FREE
712 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
713 {
714 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
715 struct hlist_node *tmp;
716 HLIST_HEAD(freelist);
717 struct debug_obj_descr *descr;
718 enum debug_obj_state state;
719 struct debug_bucket *db;
720 struct debug_obj *obj;
721 int cnt;
722
723 saddr = (unsigned long) address;
724 eaddr = saddr + size;
725 paddr = saddr & ODEBUG_CHUNK_MASK;
726 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
727 chunks >>= ODEBUG_CHUNK_SHIFT;
728
729 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
730 db = get_bucket(paddr);
731
732 repeat:
733 cnt = 0;
734 raw_spin_lock_irqsave(&db->lock, flags);
735 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
736 cnt++;
737 oaddr = (unsigned long) obj->object;
738 if (oaddr < saddr || oaddr >= eaddr)
739 continue;
740
741 switch (obj->state) {
742 case ODEBUG_STATE_ACTIVE:
743 debug_print_object(obj, "free");
744 descr = obj->descr;
745 state = obj->state;
746 raw_spin_unlock_irqrestore(&db->lock, flags);
747 debug_object_fixup(descr->fixup_free,
748 (void *) oaddr, state);
749 goto repeat;
750 default:
751 hlist_del(&obj->node);
752 hlist_add_head(&obj->node, &freelist);
753 break;
754 }
755 }
756 raw_spin_unlock_irqrestore(&db->lock, flags);
757
758 /* Now free them */
759 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
760 hlist_del(&obj->node);
761 free_object(obj);
762 }
763
764 if (cnt > debug_objects_maxchain)
765 debug_objects_maxchain = cnt;
766 }
767 }
768
769 void debug_check_no_obj_freed(const void *address, unsigned long size)
770 {
771 if (debug_objects_enabled)
772 __debug_check_no_obj_freed(address, size);
773 }
774 #endif
775
776 #ifdef CONFIG_DEBUG_FS
777
778 static int debug_stats_show(struct seq_file *m, void *v)
779 {
780 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
781 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
782 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
783 seq_printf(m, "pool_free :%d\n", obj_pool_free);
784 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
785 seq_printf(m, "pool_used :%d\n", obj_pool_used);
786 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
787 seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
788 seq_printf(m, "objs_freed :%d\n", debug_objects_freed);
789 return 0;
790 }
791
792 static int debug_stats_open(struct inode *inode, struct file *filp)
793 {
794 return single_open(filp, debug_stats_show, NULL);
795 }
796
797 static const struct file_operations debug_stats_fops = {
798 .open = debug_stats_open,
799 .read = seq_read,
800 .llseek = seq_lseek,
801 .release = single_release,
802 };
803
804 static int __init debug_objects_init_debugfs(void)
805 {
806 struct dentry *dbgdir, *dbgstats;
807
808 if (!debug_objects_enabled)
809 return 0;
810
811 dbgdir = debugfs_create_dir("debug_objects", NULL);
812 if (!dbgdir)
813 return -ENOMEM;
814
815 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
816 &debug_stats_fops);
817 if (!dbgstats)
818 goto err;
819
820 return 0;
821
822 err:
823 debugfs_remove(dbgdir);
824
825 return -ENOMEM;
826 }
827 __initcall(debug_objects_init_debugfs);
828
829 #else
830 static inline void debug_objects_init_debugfs(void) { }
831 #endif
832
833 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
834
835 /* Random data structure for the self test */
836 struct self_test {
837 unsigned long dummy1[6];
838 int static_init;
839 unsigned long dummy2[3];
840 };
841
842 static __initdata struct debug_obj_descr descr_type_test;
843
844 static bool __init is_static_object(void *addr)
845 {
846 struct self_test *obj = addr;
847
848 return obj->static_init;
849 }
850
851 /*
852 * fixup_init is called when:
853 * - an active object is initialized
854 */
855 static bool __init fixup_init(void *addr, enum debug_obj_state state)
856 {
857 struct self_test *obj = addr;
858
859 switch (state) {
860 case ODEBUG_STATE_ACTIVE:
861 debug_object_deactivate(obj, &descr_type_test);
862 debug_object_init(obj, &descr_type_test);
863 return true;
864 default:
865 return false;
866 }
867 }
868
869 /*
870 * fixup_activate is called when:
871 * - an active object is activated
872 * - an unknown non-static object is activated
873 */
874 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
875 {
876 struct self_test *obj = addr;
877
878 switch (state) {
879 case ODEBUG_STATE_NOTAVAILABLE:
880 return true;
881 case ODEBUG_STATE_ACTIVE:
882 debug_object_deactivate(obj, &descr_type_test);
883 debug_object_activate(obj, &descr_type_test);
884 return true;
885
886 default:
887 return false;
888 }
889 }
890
891 /*
892 * fixup_destroy is called when:
893 * - an active object is destroyed
894 */
895 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
896 {
897 struct self_test *obj = addr;
898
899 switch (state) {
900 case ODEBUG_STATE_ACTIVE:
901 debug_object_deactivate(obj, &descr_type_test);
902 debug_object_destroy(obj, &descr_type_test);
903 return true;
904 default:
905 return false;
906 }
907 }
908
909 /*
910 * fixup_free is called when:
911 * - an active object is freed
912 */
913 static bool __init fixup_free(void *addr, enum debug_obj_state state)
914 {
915 struct self_test *obj = addr;
916
917 switch (state) {
918 case ODEBUG_STATE_ACTIVE:
919 debug_object_deactivate(obj, &descr_type_test);
920 debug_object_free(obj, &descr_type_test);
921 return true;
922 default:
923 return false;
924 }
925 }
926
927 static int __init
928 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
929 {
930 struct debug_bucket *db;
931 struct debug_obj *obj;
932 unsigned long flags;
933 int res = -EINVAL;
934
935 db = get_bucket((unsigned long) addr);
936
937 raw_spin_lock_irqsave(&db->lock, flags);
938
939 obj = lookup_object(addr, db);
940 if (!obj && state != ODEBUG_STATE_NONE) {
941 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
942 goto out;
943 }
944 if (obj && obj->state != state) {
945 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
946 obj->state, state);
947 goto out;
948 }
949 if (fixups != debug_objects_fixups) {
950 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
951 fixups, debug_objects_fixups);
952 goto out;
953 }
954 if (warnings != debug_objects_warnings) {
955 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
956 warnings, debug_objects_warnings);
957 goto out;
958 }
959 res = 0;
960 out:
961 raw_spin_unlock_irqrestore(&db->lock, flags);
962 if (res)
963 debug_objects_enabled = 0;
964 return res;
965 }
966
967 static __initdata struct debug_obj_descr descr_type_test = {
968 .name = "selftest",
969 .is_static_object = is_static_object,
970 .fixup_init = fixup_init,
971 .fixup_activate = fixup_activate,
972 .fixup_destroy = fixup_destroy,
973 .fixup_free = fixup_free,
974 };
975
976 static __initdata struct self_test obj = { .static_init = 0 };
977
978 static void __init debug_objects_selftest(void)
979 {
980 int fixups, oldfixups, warnings, oldwarnings;
981 unsigned long flags;
982
983 local_irq_save(flags);
984
985 fixups = oldfixups = debug_objects_fixups;
986 warnings = oldwarnings = debug_objects_warnings;
987 descr_test = &descr_type_test;
988
989 debug_object_init(&obj, &descr_type_test);
990 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
991 goto out;
992 debug_object_activate(&obj, &descr_type_test);
993 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
994 goto out;
995 debug_object_activate(&obj, &descr_type_test);
996 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
997 goto out;
998 debug_object_deactivate(&obj, &descr_type_test);
999 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1000 goto out;
1001 debug_object_destroy(&obj, &descr_type_test);
1002 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1003 goto out;
1004 debug_object_init(&obj, &descr_type_test);
1005 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1006 goto out;
1007 debug_object_activate(&obj, &descr_type_test);
1008 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1009 goto out;
1010 debug_object_deactivate(&obj, &descr_type_test);
1011 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1012 goto out;
1013 debug_object_free(&obj, &descr_type_test);
1014 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1015 goto out;
1016
1017 obj.static_init = 1;
1018 debug_object_activate(&obj, &descr_type_test);
1019 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1020 goto out;
1021 debug_object_init(&obj, &descr_type_test);
1022 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1023 goto out;
1024 debug_object_free(&obj, &descr_type_test);
1025 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1026 goto out;
1027
1028 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1029 debug_object_init(&obj, &descr_type_test);
1030 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1031 goto out;
1032 debug_object_activate(&obj, &descr_type_test);
1033 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1034 goto out;
1035 __debug_check_no_obj_freed(&obj, sizeof(obj));
1036 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1037 goto out;
1038 #endif
1039 pr_info("selftest passed\n");
1040
1041 out:
1042 debug_objects_fixups = oldfixups;
1043 debug_objects_warnings = oldwarnings;
1044 descr_test = NULL;
1045
1046 local_irq_restore(flags);
1047 }
1048 #else
1049 static inline void debug_objects_selftest(void) { }
1050 #endif
1051
1052 /*
1053 * Called during early boot to initialize the hash buckets and link
1054 * the static object pool objects into the poll list. After this call
1055 * the object tracker is fully operational.
1056 */
1057 void __init debug_objects_early_init(void)
1058 {
1059 int i;
1060
1061 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1062 raw_spin_lock_init(&obj_hash[i].lock);
1063
1064 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1065 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1066 }
1067
1068 /*
1069 * Convert the statically allocated objects to dynamic ones:
1070 */
1071 static int __init debug_objects_replace_static_objects(void)
1072 {
1073 struct debug_bucket *db = obj_hash;
1074 struct hlist_node *tmp;
1075 struct debug_obj *obj, *new;
1076 HLIST_HEAD(objects);
1077 int i, cnt = 0;
1078
1079 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1080 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1081 if (!obj)
1082 goto free;
1083 hlist_add_head(&obj->node, &objects);
1084 }
1085
1086 /*
1087 * When debug_objects_mem_init() is called we know that only
1088 * one CPU is up, so disabling interrupts is enough
1089 * protection. This avoids the lockdep hell of lock ordering.
1090 */
1091 local_irq_disable();
1092
1093 /* Remove the statically allocated objects from the pool */
1094 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1095 hlist_del(&obj->node);
1096 /* Move the allocated objects to the pool */
1097 hlist_move_list(&objects, &obj_pool);
1098
1099 /* Replace the active object references */
1100 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1101 hlist_move_list(&db->list, &objects);
1102
1103 hlist_for_each_entry(obj, &objects, node) {
1104 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1105 hlist_del(&new->node);
1106 /* copy object data */
1107 *new = *obj;
1108 hlist_add_head(&new->node, &db->list);
1109 cnt++;
1110 }
1111 }
1112 local_irq_enable();
1113
1114 pr_debug("%d of %d active objects replaced\n",
1115 cnt, obj_pool_used);
1116 return 0;
1117 free:
1118 hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1119 hlist_del(&obj->node);
1120 kmem_cache_free(obj_cache, obj);
1121 }
1122 return -ENOMEM;
1123 }
1124
1125 /*
1126 * Called after the kmem_caches are functional to setup a dedicated
1127 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1128 * prevents that the debug code is called on kmem_cache_free() for the
1129 * debug tracker objects to avoid recursive calls.
1130 */
1131 void __init debug_objects_mem_init(void)
1132 {
1133 if (!debug_objects_enabled)
1134 return;
1135
1136 obj_cache = kmem_cache_create("debug_objects_cache",
1137 sizeof (struct debug_obj), 0,
1138 SLAB_DEBUG_OBJECTS, NULL);
1139
1140 if (!obj_cache || debug_objects_replace_static_objects()) {
1141 debug_objects_enabled = 0;
1142 if (obj_cache)
1143 kmem_cache_destroy(obj_cache);
1144 pr_warn("out of memory.\n");
1145 } else
1146 debug_objects_selftest();
1147
1148 /*
1149 * Increase the thresholds for allocating and freeing objects
1150 * according to the number of possible CPUs available in the system.
1151 */
1152 debug_objects_pool_size += num_possible_cpus() * 32;
1153 debug_objects_pool_min_level += num_possible_cpus() * 4;
1154 }
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