projects/linux·blob v4.15-rc7 · refs

1157 lines · 28.3 KiB

1/*
2 * Generic infrastructure for lifetime debugging of objects.
3 *
4 * Started by Thomas Gleixner
5 *
6 * Copyright (C) 2008, Thomas Gleixner <[email protected]>
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#include <linux/kmemleak.h>
22
23#define ODEBUG_HASH_BITS 14
24#define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
25
26#define ODEBUG_POOL_SIZE 1024
27#define ODEBUG_POOL_MIN_LEVEL 256
28
29#define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
30#define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
31#define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
32
33struct debug_bucket {
34 struct hlist_head list;
35 raw_spinlock_t lock;
36};
37
38static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
39
40static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
41
42static DEFINE_RAW_SPINLOCK(pool_lock);
43
44static HLIST_HEAD(obj_pool);
45
46static int obj_pool_min_free = ODEBUG_POOL_SIZE;
47static int obj_pool_free = ODEBUG_POOL_SIZE;
48static int obj_pool_used;
49static int obj_pool_max_used;
50static struct kmem_cache *obj_cache;
51
52static int debug_objects_maxchain __read_mostly;
53static int debug_objects_fixups __read_mostly;
54static int debug_objects_warnings __read_mostly;
55static int debug_objects_enabled __read_mostly
56 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
57static int debug_objects_pool_size __read_mostly
58 = ODEBUG_POOL_SIZE;
59static int debug_objects_pool_min_level __read_mostly
60 = ODEBUG_POOL_MIN_LEVEL;
61static struct debug_obj_descr *descr_test __read_mostly;
62
63/*
64 * Track numbers of kmem_cache_alloc()/free() calls done.
65 */
66static int debug_objects_allocated;
67static int debug_objects_freed;
68
69static void free_obj_work(struct work_struct *work);
70static DECLARE_WORK(debug_obj_work, free_obj_work);
71
72static int __init enable_object_debug(char *str)
73{
74 debug_objects_enabled = 1;
75 return 0;
76}
77
78static int __init disable_object_debug(char *str)
79{
80 debug_objects_enabled = 0;
81 return 0;
82}
83
84early_param("debug_objects", enable_object_debug);
85early_param("no_debug_objects", disable_object_debug);
86
87static const char *obj_states[ODEBUG_STATE_MAX] = {
88 [ODEBUG_STATE_NONE] = "none",
89 [ODEBUG_STATE_INIT] = "initialized",
90 [ODEBUG_STATE_INACTIVE] = "inactive",
91 [ODEBUG_STATE_ACTIVE] = "active",
92 [ODEBUG_STATE_DESTROYED] = "destroyed",
93 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
94};
95
96static void fill_pool(void)
97{
98 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
99 struct debug_obj *new;
100 unsigned long flags;
101
102 if (likely(obj_pool_free >= debug_objects_pool_min_level))
103 return;
104
105 if (unlikely(!obj_cache))
106 return;
107
108 while (obj_pool_free < debug_objects_pool_min_level) {
109
110 new = kmem_cache_zalloc(obj_cache, gfp);
111 if (!new)
112 return;
113
114 kmemleak_ignore(new);
115 raw_spin_lock_irqsave(&pool_lock, flags);
116 hlist_add_head(&new->node, &obj_pool);
117 debug_objects_allocated++;
118 obj_pool_free++;
119 raw_spin_unlock_irqrestore(&pool_lock, flags);
120 }
121}
122
123/*
124 * Lookup an object in the hash bucket.
125 */
126static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
127{
128 struct debug_obj *obj;
129 int cnt = 0;
130
131 hlist_for_each_entry(obj, &b->list, node) {
132 cnt++;
133 if (obj->object == addr)
134 return obj;
135 }
136 if (cnt > debug_objects_maxchain)
137 debug_objects_maxchain = cnt;
138
139 return NULL;
140}
141
142/*
143 * Allocate a new object. If the pool is empty, switch off the debugger.
144 * Must be called with interrupts disabled.
145 */
146static struct debug_obj *
147alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
148{
149 struct debug_obj *obj = NULL;
150
151 raw_spin_lock(&pool_lock);
152 if (obj_pool.first) {
153 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
154
155 obj->object = addr;
156 obj->descr = descr;
157 obj->state = ODEBUG_STATE_NONE;
158 obj->astate = 0;
159 hlist_del(&obj->node);
160
161 hlist_add_head(&obj->node, &b->list);
162
163 obj_pool_used++;
164 if (obj_pool_used > obj_pool_max_used)
165 obj_pool_max_used = obj_pool_used;
166
167 obj_pool_free--;
168 if (obj_pool_free < obj_pool_min_free)
169 obj_pool_min_free = obj_pool_free;
170 }
171 raw_spin_unlock(&pool_lock);
172
173 return obj;
174}
175
176/*
177 * workqueue function to free objects.
178 *
179 * To reduce contention on the global pool_lock, the actual freeing of
180 * debug objects will be delayed if the pool_lock is busy. We also free
181 * the objects in a batch of 4 for each lock/unlock cycle.
182 */
183#define ODEBUG_FREE_BATCH 4
184
185static void free_obj_work(struct work_struct *work)
186{
187 struct debug_obj *objs[ODEBUG_FREE_BATCH];
188 unsigned long flags;
189 int i;
190
191 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
192 return;
193 while (obj_pool_free >= debug_objects_pool_size + ODEBUG_FREE_BATCH) {
194 for (i = 0; i < ODEBUG_FREE_BATCH; i++) {
195 objs[i] = hlist_entry(obj_pool.first,
196 typeof(*objs[0]), node);
197 hlist_del(&objs[i]->node);
198 }
199
200 obj_pool_free -= ODEBUG_FREE_BATCH;
201 debug_objects_freed += ODEBUG_FREE_BATCH;
202 /*
203 * We release pool_lock across kmem_cache_free() to
204 * avoid contention on pool_lock.
205 */
206 raw_spin_unlock_irqrestore(&pool_lock, flags);
207 for (i = 0; i < ODEBUG_FREE_BATCH; i++)
208 kmem_cache_free(obj_cache, objs[i]);
209 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
210 return;
211 }
212 raw_spin_unlock_irqrestore(&pool_lock, flags);
213}
214
215/*
216 * Put the object back into the pool and schedule work to free objects
217 * if necessary.
218 */
219static void free_object(struct debug_obj *obj)
220{
221 unsigned long flags;
222 int sched = 0;
223
224 raw_spin_lock_irqsave(&pool_lock, flags);
225 /*
226 * schedule work when the pool is filled and the cache is
227 * initialized:
228 */
229 if (obj_pool_free > debug_objects_pool_size && obj_cache)
230 sched = 1;
231 hlist_add_head(&obj->node, &obj_pool);
232 obj_pool_free++;
233 obj_pool_used--;
234 raw_spin_unlock_irqrestore(&pool_lock, flags);
235 if (sched)
236 schedule_work(&debug_obj_work);
237}
238
239/*
240 * We run out of memory. That means we probably have tons of objects
241 * allocated.
242 */
243static void debug_objects_oom(void)
244{
245 struct debug_bucket *db = obj_hash;
246 struct hlist_node *tmp;
247 HLIST_HEAD(freelist);
248 struct debug_obj *obj;
249 unsigned long flags;
250 int i;
251
252 pr_warn("Out of memory. ODEBUG disabled\n");
253
254 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
255 raw_spin_lock_irqsave(&db->lock, flags);
256 hlist_move_list(&db->list, &freelist);
257 raw_spin_unlock_irqrestore(&db->lock, flags);
258
259 /* Now free them */
260 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
261 hlist_del(&obj->node);
262 free_object(obj);
263 }
264 }
265}
266
267/*
268 * We use the pfn of the address for the hash. That way we can check
269 * for freed objects simply by checking the affected bucket.
270 */
271static struct debug_bucket *get_bucket(unsigned long addr)
272{
273 unsigned long hash;
274
275 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
276 return &obj_hash[hash];
277}
278
279static void debug_print_object(struct debug_obj *obj, char *msg)
280{
281 struct debug_obj_descr *descr = obj->descr;
282 static int limit;
283
284 if (limit < 5 && descr != descr_test) {
285 void *hint = descr->debug_hint ?
286 descr->debug_hint(obj->object) : NULL;
287 limit++;
288 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
289 "object type: %s hint: %pS\n",
290 msg, obj_states[obj->state], obj->astate,
291 descr->name, hint);
292 }
293 debug_objects_warnings++;
294}
295
296/*
297 * Try to repair the damage, so we have a better chance to get useful
298 * debug output.
299 */
300static bool
301debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
302 void * addr, enum debug_obj_state state)
303{
304 if (fixup && fixup(addr, state)) {
305 debug_objects_fixups++;
306 return true;
307 }
308 return false;
309}
310
311static void debug_object_is_on_stack(void *addr, int onstack)
312{
313 int is_on_stack;
314 static int limit;
315
316 if (limit > 4)
317 return;
318
319 is_on_stack = object_is_on_stack(addr);
320 if (is_on_stack == onstack)
321 return;
322
323 limit++;
324 if (is_on_stack)
325 pr_warn("object is on stack, but not annotated\n");
326 else
327 pr_warn("object is not on stack, but annotated\n");
328 WARN_ON(1);
329}
330
331static void
332__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
333{
334 enum debug_obj_state state;
335 struct debug_bucket *db;
336 struct debug_obj *obj;
337 unsigned long flags;
338
339 fill_pool();
340
341 db = get_bucket((unsigned long) addr);
342
343 raw_spin_lock_irqsave(&db->lock, flags);
344
345 obj = lookup_object(addr, db);
346 if (!obj) {
347 obj = alloc_object(addr, db, descr);
348 if (!obj) {
349 debug_objects_enabled = 0;
350 raw_spin_unlock_irqrestore(&db->lock, flags);
351 debug_objects_oom();
352 return;
353 }
354 debug_object_is_on_stack(addr, onstack);
355 }
356
357 switch (obj->state) {
358 case ODEBUG_STATE_NONE:
359 case ODEBUG_STATE_INIT:
360 case ODEBUG_STATE_INACTIVE:
361 obj->state = ODEBUG_STATE_INIT;
362 break;
363
364 case ODEBUG_STATE_ACTIVE:
365 debug_print_object(obj, "init");
366 state = obj->state;
367 raw_spin_unlock_irqrestore(&db->lock, flags);
368 debug_object_fixup(descr->fixup_init, addr, state);
369 return;
370
371 case ODEBUG_STATE_DESTROYED:
372 debug_print_object(obj, "init");
373 break;
374 default:
375 break;
376 }
377
378 raw_spin_unlock_irqrestore(&db->lock, flags);
379}
380
381/**
382 * debug_object_init - debug checks when an object is initialized
383 * @addr: address of the object
384 * @descr: pointer to an object specific debug description structure
385 */
386void debug_object_init(void *addr, struct debug_obj_descr *descr)
387{
388 if (!debug_objects_enabled)
389 return;
390
391 __debug_object_init(addr, descr, 0);
392}
393EXPORT_SYMBOL_GPL(debug_object_init);
394
395/**
396 * debug_object_init_on_stack - debug checks when an object on stack is
397 * initialized
398 * @addr: address of the object
399 * @descr: pointer to an object specific debug description structure
400 */
401void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
402{
403 if (!debug_objects_enabled)
404 return;
405
406 __debug_object_init(addr, descr, 1);
407}
408EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
409
410/**
411 * debug_object_activate - debug checks when an object is activated
412 * @addr: address of the object
413 * @descr: pointer to an object specific debug description structure
414 * Returns 0 for success, -EINVAL for check failed.
415 */
416int debug_object_activate(void *addr, struct debug_obj_descr *descr)
417{
418 enum debug_obj_state state;
419 struct debug_bucket *db;
420 struct debug_obj *obj;
421 unsigned long flags;
422 int ret;
423 struct debug_obj o = { .object = addr,
424 .state = ODEBUG_STATE_NOTAVAILABLE,
425 .descr = descr };
426
427 if (!debug_objects_enabled)
428 return 0;
429
430 db = get_bucket((unsigned long) addr);
431
432 raw_spin_lock_irqsave(&db->lock, flags);
433
434 obj = lookup_object(addr, db);
435 if (obj) {
436 switch (obj->state) {
437 case ODEBUG_STATE_INIT:
438 case ODEBUG_STATE_INACTIVE:
439 obj->state = ODEBUG_STATE_ACTIVE;
440 ret = 0;
441 break;
442
443 case ODEBUG_STATE_ACTIVE:
444 debug_print_object(obj, "activate");
445 state = obj->state;
446 raw_spin_unlock_irqrestore(&db->lock, flags);
447 ret = debug_object_fixup(descr->fixup_activate, addr, state);
448 return ret ? 0 : -EINVAL;
449
450 case ODEBUG_STATE_DESTROYED:
451 debug_print_object(obj, "activate");
452 ret = -EINVAL;
453 break;
454 default:
455 ret = 0;
456 break;
457 }
458 raw_spin_unlock_irqrestore(&db->lock, flags);
459 return ret;
460 }
461
462 raw_spin_unlock_irqrestore(&db->lock, flags);
463 /*
464 * We are here when a static object is activated. We
465 * let the type specific code confirm whether this is
466 * true or not. if true, we just make sure that the
467 * static object is tracked in the object tracker. If
468 * not, this must be a bug, so we try to fix it up.
469 */
470 if (descr->is_static_object && descr->is_static_object(addr)) {
471 /* track this static object */
472 debug_object_init(addr, descr);
473 debug_object_activate(addr, descr);
474 } else {
475 debug_print_object(&o, "activate");
476 ret = debug_object_fixup(descr->fixup_activate, addr,
477 ODEBUG_STATE_NOTAVAILABLE);
478 return ret ? 0 : -EINVAL;
479 }
480 return 0;
481}
482EXPORT_SYMBOL_GPL(debug_object_activate);
483
484/**
485 * debug_object_deactivate - debug checks when an object is deactivated
486 * @addr: address of the object
487 * @descr: pointer to an object specific debug description structure
488 */
489void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
490{
491 struct debug_bucket *db;
492 struct debug_obj *obj;
493 unsigned long flags;
494
495 if (!debug_objects_enabled)
496 return;
497
498 db = get_bucket((unsigned long) addr);
499
500 raw_spin_lock_irqsave(&db->lock, flags);
501
502 obj = lookup_object(addr, db);
503 if (obj) {
504 switch (obj->state) {
505 case ODEBUG_STATE_INIT:
506 case ODEBUG_STATE_INACTIVE:
507 case ODEBUG_STATE_ACTIVE:
508 if (!obj->astate)
509 obj->state = ODEBUG_STATE_INACTIVE;
510 else
511 debug_print_object(obj, "deactivate");
512 break;
513
514 case ODEBUG_STATE_DESTROYED:
515 debug_print_object(obj, "deactivate");
516 break;
517 default:
518 break;
519 }
520 } else {
521 struct debug_obj o = { .object = addr,
522 .state = ODEBUG_STATE_NOTAVAILABLE,
523 .descr = descr };
524
525 debug_print_object(&o, "deactivate");
526 }
527
528 raw_spin_unlock_irqrestore(&db->lock, flags);
529}
530EXPORT_SYMBOL_GPL(debug_object_deactivate);
531
532/**
533 * debug_object_destroy - debug checks when an object is destroyed
534 * @addr: address of the object
535 * @descr: pointer to an object specific debug description structure
536 */
537void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
538{
539 enum debug_obj_state state;
540 struct debug_bucket *db;
541 struct debug_obj *obj;
542 unsigned long flags;
543
544 if (!debug_objects_enabled)
545 return;
546
547 db = get_bucket((unsigned long) addr);
548
549 raw_spin_lock_irqsave(&db->lock, flags);
550
551 obj = lookup_object(addr, db);
552 if (!obj)
553 goto out_unlock;
554
555 switch (obj->state) {
556 case ODEBUG_STATE_NONE:
557 case ODEBUG_STATE_INIT:
558 case ODEBUG_STATE_INACTIVE:
559 obj->state = ODEBUG_STATE_DESTROYED;
560 break;
561 case ODEBUG_STATE_ACTIVE:
562 debug_print_object(obj, "destroy");
563 state = obj->state;
564 raw_spin_unlock_irqrestore(&db->lock, flags);
565 debug_object_fixup(descr->fixup_destroy, addr, state);
566 return;
567
568 case ODEBUG_STATE_DESTROYED:
569 debug_print_object(obj, "destroy");
570 break;
571 default:
572 break;
573 }
574out_unlock:
575 raw_spin_unlock_irqrestore(&db->lock, flags);
576}
577EXPORT_SYMBOL_GPL(debug_object_destroy);
578
579/**
580 * debug_object_free - debug checks when an object is freed
581 * @addr: address of the object
582 * @descr: pointer to an object specific debug description structure
583 */
584void debug_object_free(void *addr, struct debug_obj_descr *descr)
585{
586 enum debug_obj_state state;
587 struct debug_bucket *db;
588 struct debug_obj *obj;
589 unsigned long flags;
590
591 if (!debug_objects_enabled)
592 return;
593
594 db = get_bucket((unsigned long) addr);
595
596 raw_spin_lock_irqsave(&db->lock, flags);
597
598 obj = lookup_object(addr, db);
599 if (!obj)
600 goto out_unlock;
601
602 switch (obj->state) {
603 case ODEBUG_STATE_ACTIVE:
604 debug_print_object(obj, "free");
605 state = obj->state;
606 raw_spin_unlock_irqrestore(&db->lock, flags);
607 debug_object_fixup(descr->fixup_free, addr, state);
608 return;
609 default:
610 hlist_del(&obj->node);
611 raw_spin_unlock_irqrestore(&db->lock, flags);
612 free_object(obj);
613 return;
614 }
615out_unlock:
616 raw_spin_unlock_irqrestore(&db->lock, flags);
617}
618EXPORT_SYMBOL_GPL(debug_object_free);
619
620/**
621 * debug_object_assert_init - debug checks when object should be init-ed
622 * @addr: address of the object
623 * @descr: pointer to an object specific debug description structure
624 */
625void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
626{
627 struct debug_bucket *db;
628 struct debug_obj *obj;
629 unsigned long flags;
630
631 if (!debug_objects_enabled)
632 return;
633
634 db = get_bucket((unsigned long) addr);
635
636 raw_spin_lock_irqsave(&db->lock, flags);
637
638 obj = lookup_object(addr, db);
639 if (!obj) {
640 struct debug_obj o = { .object = addr,
641 .state = ODEBUG_STATE_NOTAVAILABLE,
642 .descr = descr };
643
644 raw_spin_unlock_irqrestore(&db->lock, flags);
645 /*
646 * Maybe the object is static, and we let the type specific
647 * code confirm. Track this static object if true, else invoke
648 * fixup.
649 */
650 if (descr->is_static_object && descr->is_static_object(addr)) {
651 /* Track this static object */
652 debug_object_init(addr, descr);
653 } else {
654 debug_print_object(&o, "assert_init");
655 debug_object_fixup(descr->fixup_assert_init, addr,
656 ODEBUG_STATE_NOTAVAILABLE);
657 }
658 return;
659 }
660
661 raw_spin_unlock_irqrestore(&db->lock, flags);
662}
663EXPORT_SYMBOL_GPL(debug_object_assert_init);
664
665/**
666 * debug_object_active_state - debug checks object usage state machine
667 * @addr: address of the object
668 * @descr: pointer to an object specific debug description structure
669 * @expect: expected state
670 * @next: state to move to if expected state is found
671 */
672void
673debug_object_active_state(void *addr, struct debug_obj_descr *descr,
674 unsigned int expect, unsigned int next)
675{
676 struct debug_bucket *db;
677 struct debug_obj *obj;
678 unsigned long flags;
679
680 if (!debug_objects_enabled)
681 return;
682
683 db = get_bucket((unsigned long) addr);
684
685 raw_spin_lock_irqsave(&db->lock, flags);
686
687 obj = lookup_object(addr, db);
688 if (obj) {
689 switch (obj->state) {
690 case ODEBUG_STATE_ACTIVE:
691 if (obj->astate == expect)
692 obj->astate = next;
693 else
694 debug_print_object(obj, "active_state");
695 break;
696
697 default:
698 debug_print_object(obj, "active_state");
699 break;
700 }
701 } else {
702 struct debug_obj o = { .object = addr,
703 .state = ODEBUG_STATE_NOTAVAILABLE,
704 .descr = descr };
705
706 debug_print_object(&o, "active_state");
707 }
708
709 raw_spin_unlock_irqrestore(&db->lock, flags);
710}
711EXPORT_SYMBOL_GPL(debug_object_active_state);
712
713#ifdef CONFIG_DEBUG_OBJECTS_FREE
714static void __debug_check_no_obj_freed(const void *address, unsigned long size)
715{
716 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
717 struct hlist_node *tmp;
718 HLIST_HEAD(freelist);
719 struct debug_obj_descr *descr;
720 enum debug_obj_state state;
721 struct debug_bucket *db;
722 struct debug_obj *obj;
723 int cnt;
724
725 saddr = (unsigned long) address;
726 eaddr = saddr + size;
727 paddr = saddr & ODEBUG_CHUNK_MASK;
728 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
729 chunks >>= ODEBUG_CHUNK_SHIFT;
730
731 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
732 db = get_bucket(paddr);
733
734repeat:
735 cnt = 0;
736 raw_spin_lock_irqsave(&db->lock, flags);
737 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
738 cnt++;
739 oaddr = (unsigned long) obj->object;
740 if (oaddr < saddr || oaddr >= eaddr)
741 continue;
742
743 switch (obj->state) {
744 case ODEBUG_STATE_ACTIVE:
745 debug_print_object(obj, "free");
746 descr = obj->descr;
747 state = obj->state;
748 raw_spin_unlock_irqrestore(&db->lock, flags);
749 debug_object_fixup(descr->fixup_free,
750 (void *) oaddr, state);
751 goto repeat;
752 default:
753 hlist_del(&obj->node);
754 hlist_add_head(&obj->node, &freelist);
755 break;
756 }
757 }
758 raw_spin_unlock_irqrestore(&db->lock, flags);
759
760 /* Now free them */
761 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
762 hlist_del(&obj->node);
763 free_object(obj);
764 }
765
766 if (cnt > debug_objects_maxchain)
767 debug_objects_maxchain = cnt;
768 }
769}
770
771void debug_check_no_obj_freed(const void *address, unsigned long size)
772{
773 if (debug_objects_enabled)
774 __debug_check_no_obj_freed(address, size);
775}
776#endif
777
778#ifdef CONFIG_DEBUG_FS
779
780static int debug_stats_show(struct seq_file *m, void *v)
781{
782 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
783 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
784 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
785 seq_printf(m, "pool_free :%d\n", obj_pool_free);
786 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
787 seq_printf(m, "pool_used :%d\n", obj_pool_used);
788 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
789 seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
790 seq_printf(m, "objs_freed :%d\n", debug_objects_freed);
791 return 0;
792}
793
794static int debug_stats_open(struct inode *inode, struct file *filp)
795{
796 return single_open(filp, debug_stats_show, NULL);
797}
798
799static const struct file_operations debug_stats_fops = {
800 .open = debug_stats_open,
801 .read = seq_read,
802 .llseek = seq_lseek,
803 .release = single_release,
804};
805
806static int __init debug_objects_init_debugfs(void)
807{
808 struct dentry *dbgdir, *dbgstats;
809
810 if (!debug_objects_enabled)
811 return 0;
812
813 dbgdir = debugfs_create_dir("debug_objects", NULL);
814 if (!dbgdir)
815 return -ENOMEM;
816
817 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
818 &debug_stats_fops);
819 if (!dbgstats)
820 goto err;
821
822 return 0;
823
824err:
825 debugfs_remove(dbgdir);
826
827 return -ENOMEM;
828}
829__initcall(debug_objects_init_debugfs);
830
831#else
832static inline void debug_objects_init_debugfs(void) { }
833#endif
834
835#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
836
837/* Random data structure for the self test */
838struct self_test {
839 unsigned long dummy1[6];
840 int static_init;
841 unsigned long dummy2[3];
842};
843
844static __initdata struct debug_obj_descr descr_type_test;
845
846static bool __init is_static_object(void *addr)
847{
848 struct self_test *obj = addr;
849
850 return obj->static_init;
851}
852
853/*
854 * fixup_init is called when:
855 * - an active object is initialized
856 */
857static bool __init fixup_init(void *addr, enum debug_obj_state state)
858{
859 struct self_test *obj = addr;
860
861 switch (state) {
862 case ODEBUG_STATE_ACTIVE:
863 debug_object_deactivate(obj, &descr_type_test);
864 debug_object_init(obj, &descr_type_test);
865 return true;
866 default:
867 return false;
868 }
869}
870
871/*
872 * fixup_activate is called when:
873 * - an active object is activated
874 * - an unknown non-static object is activated
875 */
876static bool __init fixup_activate(void *addr, enum debug_obj_state state)
877{
878 struct self_test *obj = addr;
879
880 switch (state) {
881 case ODEBUG_STATE_NOTAVAILABLE:
882 return true;
883 case ODEBUG_STATE_ACTIVE:
884 debug_object_deactivate(obj, &descr_type_test);
885 debug_object_activate(obj, &descr_type_test);
886 return true;
887
888 default:
889 return false;
890 }
891}
892
893/*
894 * fixup_destroy is called when:
895 * - an active object is destroyed
896 */
897static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
898{
899 struct self_test *obj = addr;
900
901 switch (state) {
902 case ODEBUG_STATE_ACTIVE:
903 debug_object_deactivate(obj, &descr_type_test);
904 debug_object_destroy(obj, &descr_type_test);
905 return true;
906 default:
907 return false;
908 }
909}
910
911/*
912 * fixup_free is called when:
913 * - an active object is freed
914 */
915static bool __init fixup_free(void *addr, enum debug_obj_state state)
916{
917 struct self_test *obj = addr;
918
919 switch (state) {
920 case ODEBUG_STATE_ACTIVE:
921 debug_object_deactivate(obj, &descr_type_test);
922 debug_object_free(obj, &descr_type_test);
923 return true;
924 default:
925 return false;
926 }
927}
928
929static int __init
930check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
931{
932 struct debug_bucket *db;
933 struct debug_obj *obj;
934 unsigned long flags;
935 int res = -EINVAL;
936
937 db = get_bucket((unsigned long) addr);
938
939 raw_spin_lock_irqsave(&db->lock, flags);
940
941 obj = lookup_object(addr, db);
942 if (!obj && state != ODEBUG_STATE_NONE) {
943 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
944 goto out;
945 }
946 if (obj && obj->state != state) {
947 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
948 obj->state, state);
949 goto out;
950 }
951 if (fixups != debug_objects_fixups) {
952 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
953 fixups, debug_objects_fixups);
954 goto out;
955 }
956 if (warnings != debug_objects_warnings) {
957 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
958 warnings, debug_objects_warnings);
959 goto out;
960 }
961 res = 0;
962out:
963 raw_spin_unlock_irqrestore(&db->lock, flags);
964 if (res)
965 debug_objects_enabled = 0;
966 return res;
967}
968
969static __initdata struct debug_obj_descr descr_type_test = {
970 .name = "selftest",
971 .is_static_object = is_static_object,
972 .fixup_init = fixup_init,
973 .fixup_activate = fixup_activate,
974 .fixup_destroy = fixup_destroy,
975 .fixup_free = fixup_free,
976};
977
978static __initdata struct self_test obj = { .static_init = 0 };
979
980static void __init debug_objects_selftest(void)
981{
982 int fixups, oldfixups, warnings, oldwarnings;
983 unsigned long flags;
984
985 local_irq_save(flags);
986
987 fixups = oldfixups = debug_objects_fixups;
988 warnings = oldwarnings = debug_objects_warnings;
989 descr_test = &descr_type_test;
990
991 debug_object_init(&obj, &descr_type_test);
992 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
993 goto out;
994 debug_object_activate(&obj, &descr_type_test);
995 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
996 goto out;
997 debug_object_activate(&obj, &descr_type_test);
998 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
999 goto out;
1000 debug_object_deactivate(&obj, &descr_type_test);
1001 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1002 goto out;
1003 debug_object_destroy(&obj, &descr_type_test);
1004 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1005 goto out;
1006 debug_object_init(&obj, &descr_type_test);
1007 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1008 goto out;
1009 debug_object_activate(&obj, &descr_type_test);
1010 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1011 goto out;
1012 debug_object_deactivate(&obj, &descr_type_test);
1013 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1014 goto out;
1015 debug_object_free(&obj, &descr_type_test);
1016 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1017 goto out;
1018
1019 obj.static_init = 1;
1020 debug_object_activate(&obj, &descr_type_test);
1021 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1022 goto out;
1023 debug_object_init(&obj, &descr_type_test);
1024 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1025 goto out;
1026 debug_object_free(&obj, &descr_type_test);
1027 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1028 goto out;
1029
1030#ifdef CONFIG_DEBUG_OBJECTS_FREE
1031 debug_object_init(&obj, &descr_type_test);
1032 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1033 goto out;
1034 debug_object_activate(&obj, &descr_type_test);
1035 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1036 goto out;
1037 __debug_check_no_obj_freed(&obj, sizeof(obj));
1038 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1039 goto out;
1040#endif
1041 pr_info("selftest passed\n");
1042
1043out:
1044 debug_objects_fixups = oldfixups;
1045 debug_objects_warnings = oldwarnings;
1046 descr_test = NULL;
1047
1048 local_irq_restore(flags);
1049}
1050#else
1051static inline void debug_objects_selftest(void) { }
1052#endif
1053
1054/*
1055 * Called during early boot to initialize the hash buckets and link
1056 * the static object pool objects into the poll list. After this call
1057 * the object tracker is fully operational.
1058 */
1059void __init debug_objects_early_init(void)
1060{
1061 int i;
1062
1063 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1064 raw_spin_lock_init(&obj_hash[i].lock);
1065
1066 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1067 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1068}
1069
1070/*
1071 * Convert the statically allocated objects to dynamic ones:
1072 */
1073static int __init debug_objects_replace_static_objects(void)
1074{
1075 struct debug_bucket *db = obj_hash;
1076 struct hlist_node *tmp;
1077 struct debug_obj *obj, *new;
1078 HLIST_HEAD(objects);
1079 int i, cnt = 0;
1080
1081 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1082 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1083 if (!obj)
1084 goto free;
1085 kmemleak_ignore(obj);
1086 hlist_add_head(&obj->node, &objects);
1087 }
1088
1089 /*
1090 * When debug_objects_mem_init() is called we know that only
1091 * one CPU is up, so disabling interrupts is enough
1092 * protection. This avoids the lockdep hell of lock ordering.
1093 */
1094 local_irq_disable();
1095
1096 /* Remove the statically allocated objects from the pool */
1097 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1098 hlist_del(&obj->node);
1099 /* Move the allocated objects to the pool */
1100 hlist_move_list(&objects, &obj_pool);
1101
1102 /* Replace the active object references */
1103 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1104 hlist_move_list(&db->list, &objects);
1105
1106 hlist_for_each_entry(obj, &objects, node) {
1107 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1108 hlist_del(&new->node);
1109 /* copy object data */
1110 *new = *obj;
1111 hlist_add_head(&new->node, &db->list);
1112 cnt++;
1113 }
1114 }
1115 local_irq_enable();
1116
1117 pr_debug("%d of %d active objects replaced\n",
1118 cnt, obj_pool_used);
1119 return 0;
1120free:
1121 hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1122 hlist_del(&obj->node);
1123 kmem_cache_free(obj_cache, obj);
1124 }
1125 return -ENOMEM;
1126}
1127
1128/*
1129 * Called after the kmem_caches are functional to setup a dedicated
1130 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1131 * prevents that the debug code is called on kmem_cache_free() for the
1132 * debug tracker objects to avoid recursive calls.
1133 */
1134void __init debug_objects_mem_init(void)
1135{
1136 if (!debug_objects_enabled)
1137 return;
1138
1139 obj_cache = kmem_cache_create("debug_objects_cache",
1140 sizeof (struct debug_obj), 0,
1141 SLAB_DEBUG_OBJECTS, NULL);
1142
1143 if (!obj_cache || debug_objects_replace_static_objects()) {
1144 debug_objects_enabled = 0;
1145 if (obj_cache)
1146 kmem_cache_destroy(obj_cache);
1147 pr_warn("out of memory.\n");
1148 } else
1149 debug_objects_selftest();
1150
1151 /*
1152 * Increase the thresholds for allocating and freeing objects
1153 * according to the number of possible CPUs available in the system.
1154 */
1155 debug_objects_pool_size += num_possible_cpus() * 32;
1156 debug_objects_pool_min_level += num_possible_cpus() * 4;
1157}