projects/linux·blob v4.10-rc3 · refs

1119 lines · 26.9 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/seq_file.h>
17#include <linux/debugfs.h>
18#include <linux/slab.h>
19#include <linux/hash.h>
20
21#define ODEBUG_HASH_BITS 14
22#define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
23
24#define ODEBUG_POOL_SIZE 1024
25#define ODEBUG_POOL_MIN_LEVEL 256
26
27#define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
28#define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
29#define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
30
31struct debug_bucket {
32 struct hlist_head list;
33 raw_spinlock_t lock;
34};
35
36static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
37
38static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
39
40static DEFINE_RAW_SPINLOCK(pool_lock);
41
42static HLIST_HEAD(obj_pool);
43
44static int obj_pool_min_free = ODEBUG_POOL_SIZE;
45static int obj_pool_free = ODEBUG_POOL_SIZE;
46static int obj_pool_used;
47static int obj_pool_max_used;
48static struct kmem_cache *obj_cache;
49
50static int debug_objects_maxchain __read_mostly;
51static int debug_objects_fixups __read_mostly;
52static int debug_objects_warnings __read_mostly;
53static int debug_objects_enabled __read_mostly
54 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
55
56static struct debug_obj_descr *descr_test __read_mostly;
57
58static void free_obj_work(struct work_struct *work);
59static DECLARE_WORK(debug_obj_work, free_obj_work);
60
61static int __init enable_object_debug(char *str)
62{
63 debug_objects_enabled = 1;
64 return 0;
65}
66
67static int __init disable_object_debug(char *str)
68{
69 debug_objects_enabled = 0;
70 return 0;
71}
72
73early_param("debug_objects", enable_object_debug);
74early_param("no_debug_objects", disable_object_debug);
75
76static const char *obj_states[ODEBUG_STATE_MAX] = {
77 [ODEBUG_STATE_NONE] = "none",
78 [ODEBUG_STATE_INIT] = "initialized",
79 [ODEBUG_STATE_INACTIVE] = "inactive",
80 [ODEBUG_STATE_ACTIVE] = "active",
81 [ODEBUG_STATE_DESTROYED] = "destroyed",
82 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
83};
84
85static void fill_pool(void)
86{
87 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
88 struct debug_obj *new;
89 unsigned long flags;
90
91 if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
92 return;
93
94 if (unlikely(!obj_cache))
95 return;
96
97 while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
98
99 new = kmem_cache_zalloc(obj_cache, gfp);
100 if (!new)
101 return;
102
103 raw_spin_lock_irqsave(&pool_lock, flags);
104 hlist_add_head(&new->node, &obj_pool);
105 obj_pool_free++;
106 raw_spin_unlock_irqrestore(&pool_lock, flags);
107 }
108}
109
110/*
111 * Lookup an object in the hash bucket.
112 */
113static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
114{
115 struct debug_obj *obj;
116 int cnt = 0;
117
118 hlist_for_each_entry(obj, &b->list, node) {
119 cnt++;
120 if (obj->object == addr)
121 return obj;
122 }
123 if (cnt > debug_objects_maxchain)
124 debug_objects_maxchain = cnt;
125
126 return NULL;
127}
128
129/*
130 * Allocate a new object. If the pool is empty, switch off the debugger.
131 * Must be called with interrupts disabled.
132 */
133static struct debug_obj *
134alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
135{
136 struct debug_obj *obj = NULL;
137
138 raw_spin_lock(&pool_lock);
139 if (obj_pool.first) {
140 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
141
142 obj->object = addr;
143 obj->descr = descr;
144 obj->state = ODEBUG_STATE_NONE;
145 obj->astate = 0;
146 hlist_del(&obj->node);
147
148 hlist_add_head(&obj->node, &b->list);
149
150 obj_pool_used++;
151 if (obj_pool_used > obj_pool_max_used)
152 obj_pool_max_used = obj_pool_used;
153
154 obj_pool_free--;
155 if (obj_pool_free < obj_pool_min_free)
156 obj_pool_min_free = obj_pool_free;
157 }
158 raw_spin_unlock(&pool_lock);
159
160 return obj;
161}
162
163/*
164 * workqueue function to free objects.
165 */
166static void free_obj_work(struct work_struct *work)
167{
168 struct debug_obj *obj;
169 unsigned long flags;
170
171 raw_spin_lock_irqsave(&pool_lock, flags);
172 while (obj_pool_free > ODEBUG_POOL_SIZE) {
173 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
174 hlist_del(&obj->node);
175 obj_pool_free--;
176 /*
177 * We release pool_lock across kmem_cache_free() to
178 * avoid contention on pool_lock.
179 */
180 raw_spin_unlock_irqrestore(&pool_lock, flags);
181 kmem_cache_free(obj_cache, obj);
182 raw_spin_lock_irqsave(&pool_lock, flags);
183 }
184 raw_spin_unlock_irqrestore(&pool_lock, flags);
185}
186
187/*
188 * Put the object back into the pool and schedule work to free objects
189 * if necessary.
190 */
191static void free_object(struct debug_obj *obj)
192{
193 unsigned long flags;
194 int sched = 0;
195
196 raw_spin_lock_irqsave(&pool_lock, flags);
197 /*
198 * schedule work when the pool is filled and the cache is
199 * initialized:
200 */
201 if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache)
202 sched = 1;
203 hlist_add_head(&obj->node, &obj_pool);
204 obj_pool_free++;
205 obj_pool_used--;
206 raw_spin_unlock_irqrestore(&pool_lock, flags);
207 if (sched)
208 schedule_work(&debug_obj_work);
209}
210
211/*
212 * We run out of memory. That means we probably have tons of objects
213 * allocated.
214 */
215static void debug_objects_oom(void)
216{
217 struct debug_bucket *db = obj_hash;
218 struct hlist_node *tmp;
219 HLIST_HEAD(freelist);
220 struct debug_obj *obj;
221 unsigned long flags;
222 int i;
223
224 pr_warn("Out of memory. ODEBUG disabled\n");
225
226 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
227 raw_spin_lock_irqsave(&db->lock, flags);
228 hlist_move_list(&db->list, &freelist);
229 raw_spin_unlock_irqrestore(&db->lock, flags);
230
231 /* Now free them */
232 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
233 hlist_del(&obj->node);
234 free_object(obj);
235 }
236 }
237}
238
239/*
240 * We use the pfn of the address for the hash. That way we can check
241 * for freed objects simply by checking the affected bucket.
242 */
243static struct debug_bucket *get_bucket(unsigned long addr)
244{
245 unsigned long hash;
246
247 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
248 return &obj_hash[hash];
249}
250
251static void debug_print_object(struct debug_obj *obj, char *msg)
252{
253 struct debug_obj_descr *descr = obj->descr;
254 static int limit;
255
256 if (limit < 5 && descr != descr_test) {
257 void *hint = descr->debug_hint ?
258 descr->debug_hint(obj->object) : NULL;
259 limit++;
260 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
261 "object type: %s hint: %pS\n",
262 msg, obj_states[obj->state], obj->astate,
263 descr->name, hint);
264 }
265 debug_objects_warnings++;
266}
267
268/*
269 * Try to repair the damage, so we have a better chance to get useful
270 * debug output.
271 */
272static bool
273debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
274 void * addr, enum debug_obj_state state)
275{
276 if (fixup && fixup(addr, state)) {
277 debug_objects_fixups++;
278 return true;
279 }
280 return false;
281}
282
283static void debug_object_is_on_stack(void *addr, int onstack)
284{
285 int is_on_stack;
286 static int limit;
287
288 if (limit > 4)
289 return;
290
291 is_on_stack = object_is_on_stack(addr);
292 if (is_on_stack == onstack)
293 return;
294
295 limit++;
296 if (is_on_stack)
297 pr_warn("object is on stack, but not annotated\n");
298 else
299 pr_warn("object is not on stack, but annotated\n");
300 WARN_ON(1);
301}
302
303static void
304__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
305{
306 enum debug_obj_state state;
307 struct debug_bucket *db;
308 struct debug_obj *obj;
309 unsigned long flags;
310
311 fill_pool();
312
313 db = get_bucket((unsigned long) addr);
314
315 raw_spin_lock_irqsave(&db->lock, flags);
316
317 obj = lookup_object(addr, db);
318 if (!obj) {
319 obj = alloc_object(addr, db, descr);
320 if (!obj) {
321 debug_objects_enabled = 0;
322 raw_spin_unlock_irqrestore(&db->lock, flags);
323 debug_objects_oom();
324 return;
325 }
326 debug_object_is_on_stack(addr, onstack);
327 }
328
329 switch (obj->state) {
330 case ODEBUG_STATE_NONE:
331 case ODEBUG_STATE_INIT:
332 case ODEBUG_STATE_INACTIVE:
333 obj->state = ODEBUG_STATE_INIT;
334 break;
335
336 case ODEBUG_STATE_ACTIVE:
337 debug_print_object(obj, "init");
338 state = obj->state;
339 raw_spin_unlock_irqrestore(&db->lock, flags);
340 debug_object_fixup(descr->fixup_init, addr, state);
341 return;
342
343 case ODEBUG_STATE_DESTROYED:
344 debug_print_object(obj, "init");
345 break;
346 default:
347 break;
348 }
349
350 raw_spin_unlock_irqrestore(&db->lock, flags);
351}
352
353/**
354 * debug_object_init - debug checks when an object is initialized
355 * @addr: address of the object
356 * @descr: pointer to an object specific debug description structure
357 */
358void debug_object_init(void *addr, struct debug_obj_descr *descr)
359{
360 if (!debug_objects_enabled)
361 return;
362
363 __debug_object_init(addr, descr, 0);
364}
365EXPORT_SYMBOL_GPL(debug_object_init);
366
367/**
368 * debug_object_init_on_stack - debug checks when an object on stack is
369 * initialized
370 * @addr: address of the object
371 * @descr: pointer to an object specific debug description structure
372 */
373void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
374{
375 if (!debug_objects_enabled)
376 return;
377
378 __debug_object_init(addr, descr, 1);
379}
380EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
381
382/**
383 * debug_object_activate - debug checks when an object is activated
384 * @addr: address of the object
385 * @descr: pointer to an object specific debug description structure
386 * Returns 0 for success, -EINVAL for check failed.
387 */
388int debug_object_activate(void *addr, struct debug_obj_descr *descr)
389{
390 enum debug_obj_state state;
391 struct debug_bucket *db;
392 struct debug_obj *obj;
393 unsigned long flags;
394 int ret;
395 struct debug_obj o = { .object = addr,
396 .state = ODEBUG_STATE_NOTAVAILABLE,
397 .descr = descr };
398
399 if (!debug_objects_enabled)
400 return 0;
401
402 db = get_bucket((unsigned long) addr);
403
404 raw_spin_lock_irqsave(&db->lock, flags);
405
406 obj = lookup_object(addr, db);
407 if (obj) {
408 switch (obj->state) {
409 case ODEBUG_STATE_INIT:
410 case ODEBUG_STATE_INACTIVE:
411 obj->state = ODEBUG_STATE_ACTIVE;
412 ret = 0;
413 break;
414
415 case ODEBUG_STATE_ACTIVE:
416 debug_print_object(obj, "activate");
417 state = obj->state;
418 raw_spin_unlock_irqrestore(&db->lock, flags);
419 ret = debug_object_fixup(descr->fixup_activate, addr, state);
420 return ret ? 0 : -EINVAL;
421
422 case ODEBUG_STATE_DESTROYED:
423 debug_print_object(obj, "activate");
424 ret = -EINVAL;
425 break;
426 default:
427 ret = 0;
428 break;
429 }
430 raw_spin_unlock_irqrestore(&db->lock, flags);
431 return ret;
432 }
433
434 raw_spin_unlock_irqrestore(&db->lock, flags);
435 /*
436 * We are here when a static object is activated. We
437 * let the type specific code confirm whether this is
438 * true or not. if true, we just make sure that the
439 * static object is tracked in the object tracker. If
440 * not, this must be a bug, so we try to fix it up.
441 */
442 if (descr->is_static_object && descr->is_static_object(addr)) {
443 /* track this static object */
444 debug_object_init(addr, descr);
445 debug_object_activate(addr, descr);
446 } else {
447 debug_print_object(&o, "activate");
448 ret = debug_object_fixup(descr->fixup_activate, addr,
449 ODEBUG_STATE_NOTAVAILABLE);
450 return ret ? 0 : -EINVAL;
451 }
452 return 0;
453}
454EXPORT_SYMBOL_GPL(debug_object_activate);
455
456/**
457 * debug_object_deactivate - debug checks when an object is deactivated
458 * @addr: address of the object
459 * @descr: pointer to an object specific debug description structure
460 */
461void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
462{
463 struct debug_bucket *db;
464 struct debug_obj *obj;
465 unsigned long flags;
466
467 if (!debug_objects_enabled)
468 return;
469
470 db = get_bucket((unsigned long) addr);
471
472 raw_spin_lock_irqsave(&db->lock, flags);
473
474 obj = lookup_object(addr, db);
475 if (obj) {
476 switch (obj->state) {
477 case ODEBUG_STATE_INIT:
478 case ODEBUG_STATE_INACTIVE:
479 case ODEBUG_STATE_ACTIVE:
480 if (!obj->astate)
481 obj->state = ODEBUG_STATE_INACTIVE;
482 else
483 debug_print_object(obj, "deactivate");
484 break;
485
486 case ODEBUG_STATE_DESTROYED:
487 debug_print_object(obj, "deactivate");
488 break;
489 default:
490 break;
491 }
492 } else {
493 struct debug_obj o = { .object = addr,
494 .state = ODEBUG_STATE_NOTAVAILABLE,
495 .descr = descr };
496
497 debug_print_object(&o, "deactivate");
498 }
499
500 raw_spin_unlock_irqrestore(&db->lock, flags);
501}
502EXPORT_SYMBOL_GPL(debug_object_deactivate);
503
504/**
505 * debug_object_destroy - debug checks when an object is destroyed
506 * @addr: address of the object
507 * @descr: pointer to an object specific debug description structure
508 */
509void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
510{
511 enum debug_obj_state state;
512 struct debug_bucket *db;
513 struct debug_obj *obj;
514 unsigned long flags;
515
516 if (!debug_objects_enabled)
517 return;
518
519 db = get_bucket((unsigned long) addr);
520
521 raw_spin_lock_irqsave(&db->lock, flags);
522
523 obj = lookup_object(addr, db);
524 if (!obj)
525 goto out_unlock;
526
527 switch (obj->state) {
528 case ODEBUG_STATE_NONE:
529 case ODEBUG_STATE_INIT:
530 case ODEBUG_STATE_INACTIVE:
531 obj->state = ODEBUG_STATE_DESTROYED;
532 break;
533 case ODEBUG_STATE_ACTIVE:
534 debug_print_object(obj, "destroy");
535 state = obj->state;
536 raw_spin_unlock_irqrestore(&db->lock, flags);
537 debug_object_fixup(descr->fixup_destroy, addr, state);
538 return;
539
540 case ODEBUG_STATE_DESTROYED:
541 debug_print_object(obj, "destroy");
542 break;
543 default:
544 break;
545 }
546out_unlock:
547 raw_spin_unlock_irqrestore(&db->lock, flags);
548}
549EXPORT_SYMBOL_GPL(debug_object_destroy);
550
551/**
552 * debug_object_free - debug checks when an object is freed
553 * @addr: address of the object
554 * @descr: pointer to an object specific debug description structure
555 */
556void debug_object_free(void *addr, struct debug_obj_descr *descr)
557{
558 enum debug_obj_state state;
559 struct debug_bucket *db;
560 struct debug_obj *obj;
561 unsigned long flags;
562
563 if (!debug_objects_enabled)
564 return;
565
566 db = get_bucket((unsigned long) addr);
567
568 raw_spin_lock_irqsave(&db->lock, flags);
569
570 obj = lookup_object(addr, db);
571 if (!obj)
572 goto out_unlock;
573
574 switch (obj->state) {
575 case ODEBUG_STATE_ACTIVE:
576 debug_print_object(obj, "free");
577 state = obj->state;
578 raw_spin_unlock_irqrestore(&db->lock, flags);
579 debug_object_fixup(descr->fixup_free, addr, state);
580 return;
581 default:
582 hlist_del(&obj->node);
583 raw_spin_unlock_irqrestore(&db->lock, flags);
584 free_object(obj);
585 return;
586 }
587out_unlock:
588 raw_spin_unlock_irqrestore(&db->lock, flags);
589}
590EXPORT_SYMBOL_GPL(debug_object_free);
591
592/**
593 * debug_object_assert_init - debug checks when object should be init-ed
594 * @addr: address of the object
595 * @descr: pointer to an object specific debug description structure
596 */
597void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
598{
599 struct debug_bucket *db;
600 struct debug_obj *obj;
601 unsigned long flags;
602
603 if (!debug_objects_enabled)
604 return;
605
606 db = get_bucket((unsigned long) addr);
607
608 raw_spin_lock_irqsave(&db->lock, flags);
609
610 obj = lookup_object(addr, db);
611 if (!obj) {
612 struct debug_obj o = { .object = addr,
613 .state = ODEBUG_STATE_NOTAVAILABLE,
614 .descr = descr };
615
616 raw_spin_unlock_irqrestore(&db->lock, flags);
617 /*
618 * Maybe the object is static, and we let the type specific
619 * code confirm. Track this static object if true, else invoke
620 * fixup.
621 */
622 if (descr->is_static_object && descr->is_static_object(addr)) {
623 /* Track this static object */
624 debug_object_init(addr, descr);
625 } else {
626 debug_print_object(&o, "assert_init");
627 debug_object_fixup(descr->fixup_assert_init, addr,
628 ODEBUG_STATE_NOTAVAILABLE);
629 }
630 return;
631 }
632
633 raw_spin_unlock_irqrestore(&db->lock, flags);
634}
635EXPORT_SYMBOL_GPL(debug_object_assert_init);
636
637/**
638 * debug_object_active_state - debug checks object usage state machine
639 * @addr: address of the object
640 * @descr: pointer to an object specific debug description structure
641 * @expect: expected state
642 * @next: state to move to if expected state is found
643 */
644void
645debug_object_active_state(void *addr, struct debug_obj_descr *descr,
646 unsigned int expect, unsigned int next)
647{
648 struct debug_bucket *db;
649 struct debug_obj *obj;
650 unsigned long flags;
651
652 if (!debug_objects_enabled)
653 return;
654
655 db = get_bucket((unsigned long) addr);
656
657 raw_spin_lock_irqsave(&db->lock, flags);
658
659 obj = lookup_object(addr, db);
660 if (obj) {
661 switch (obj->state) {
662 case ODEBUG_STATE_ACTIVE:
663 if (obj->astate == expect)
664 obj->astate = next;
665 else
666 debug_print_object(obj, "active_state");
667 break;
668
669 default:
670 debug_print_object(obj, "active_state");
671 break;
672 }
673 } else {
674 struct debug_obj o = { .object = addr,
675 .state = ODEBUG_STATE_NOTAVAILABLE,
676 .descr = descr };
677
678 debug_print_object(&o, "active_state");
679 }
680
681 raw_spin_unlock_irqrestore(&db->lock, flags);
682}
683EXPORT_SYMBOL_GPL(debug_object_active_state);
684
685#ifdef CONFIG_DEBUG_OBJECTS_FREE
686static void __debug_check_no_obj_freed(const void *address, unsigned long size)
687{
688 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
689 struct hlist_node *tmp;
690 HLIST_HEAD(freelist);
691 struct debug_obj_descr *descr;
692 enum debug_obj_state state;
693 struct debug_bucket *db;
694 struct debug_obj *obj;
695 int cnt;
696
697 saddr = (unsigned long) address;
698 eaddr = saddr + size;
699 paddr = saddr & ODEBUG_CHUNK_MASK;
700 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
701 chunks >>= ODEBUG_CHUNK_SHIFT;
702
703 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
704 db = get_bucket(paddr);
705
706repeat:
707 cnt = 0;
708 raw_spin_lock_irqsave(&db->lock, flags);
709 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
710 cnt++;
711 oaddr = (unsigned long) obj->object;
712 if (oaddr < saddr || oaddr >= eaddr)
713 continue;
714
715 switch (obj->state) {
716 case ODEBUG_STATE_ACTIVE:
717 debug_print_object(obj, "free");
718 descr = obj->descr;
719 state = obj->state;
720 raw_spin_unlock_irqrestore(&db->lock, flags);
721 debug_object_fixup(descr->fixup_free,
722 (void *) oaddr, state);
723 goto repeat;
724 default:
725 hlist_del(&obj->node);
726 hlist_add_head(&obj->node, &freelist);
727 break;
728 }
729 }
730 raw_spin_unlock_irqrestore(&db->lock, flags);
731
732 /* Now free them */
733 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
734 hlist_del(&obj->node);
735 free_object(obj);
736 }
737
738 if (cnt > debug_objects_maxchain)
739 debug_objects_maxchain = cnt;
740 }
741}
742
743void debug_check_no_obj_freed(const void *address, unsigned long size)
744{
745 if (debug_objects_enabled)
746 __debug_check_no_obj_freed(address, size);
747}
748#endif
749
750#ifdef CONFIG_DEBUG_FS
751
752static int debug_stats_show(struct seq_file *m, void *v)
753{
754 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
755 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
756 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
757 seq_printf(m, "pool_free :%d\n", obj_pool_free);
758 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
759 seq_printf(m, "pool_used :%d\n", obj_pool_used);
760 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
761 return 0;
762}
763
764static int debug_stats_open(struct inode *inode, struct file *filp)
765{
766 return single_open(filp, debug_stats_show, NULL);
767}
768
769static const struct file_operations debug_stats_fops = {
770 .open = debug_stats_open,
771 .read = seq_read,
772 .llseek = seq_lseek,
773 .release = single_release,
774};
775
776static int __init debug_objects_init_debugfs(void)
777{
778 struct dentry *dbgdir, *dbgstats;
779
780 if (!debug_objects_enabled)
781 return 0;
782
783 dbgdir = debugfs_create_dir("debug_objects", NULL);
784 if (!dbgdir)
785 return -ENOMEM;
786
787 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
788 &debug_stats_fops);
789 if (!dbgstats)
790 goto err;
791
792 return 0;
793
794err:
795 debugfs_remove(dbgdir);
796
797 return -ENOMEM;
798}
799__initcall(debug_objects_init_debugfs);
800
801#else
802static inline void debug_objects_init_debugfs(void) { }
803#endif
804
805#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
806
807/* Random data structure for the self test */
808struct self_test {
809 unsigned long dummy1[6];
810 int static_init;
811 unsigned long dummy2[3];
812};
813
814static __initdata struct debug_obj_descr descr_type_test;
815
816static bool __init is_static_object(void *addr)
817{
818 struct self_test *obj = addr;
819
820 return obj->static_init;
821}
822
823/*
824 * fixup_init is called when:
825 * - an active object is initialized
826 */
827static bool __init fixup_init(void *addr, enum debug_obj_state state)
828{
829 struct self_test *obj = addr;
830
831 switch (state) {
832 case ODEBUG_STATE_ACTIVE:
833 debug_object_deactivate(obj, &descr_type_test);
834 debug_object_init(obj, &descr_type_test);
835 return true;
836 default:
837 return false;
838 }
839}
840
841/*
842 * fixup_activate is called when:
843 * - an active object is activated
844 * - an unknown non-static object is activated
845 */
846static bool __init fixup_activate(void *addr, enum debug_obj_state state)
847{
848 struct self_test *obj = addr;
849
850 switch (state) {
851 case ODEBUG_STATE_NOTAVAILABLE:
852 return true;
853 case ODEBUG_STATE_ACTIVE:
854 debug_object_deactivate(obj, &descr_type_test);
855 debug_object_activate(obj, &descr_type_test);
856 return true;
857
858 default:
859 return false;
860 }
861}
862
863/*
864 * fixup_destroy is called when:
865 * - an active object is destroyed
866 */
867static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
868{
869 struct self_test *obj = addr;
870
871 switch (state) {
872 case ODEBUG_STATE_ACTIVE:
873 debug_object_deactivate(obj, &descr_type_test);
874 debug_object_destroy(obj, &descr_type_test);
875 return true;
876 default:
877 return false;
878 }
879}
880
881/*
882 * fixup_free is called when:
883 * - an active object is freed
884 */
885static bool __init fixup_free(void *addr, enum debug_obj_state state)
886{
887 struct self_test *obj = addr;
888
889 switch (state) {
890 case ODEBUG_STATE_ACTIVE:
891 debug_object_deactivate(obj, &descr_type_test);
892 debug_object_free(obj, &descr_type_test);
893 return true;
894 default:
895 return false;
896 }
897}
898
899static int __init
900check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
901{
902 struct debug_bucket *db;
903 struct debug_obj *obj;
904 unsigned long flags;
905 int res = -EINVAL;
906
907 db = get_bucket((unsigned long) addr);
908
909 raw_spin_lock_irqsave(&db->lock, flags);
910
911 obj = lookup_object(addr, db);
912 if (!obj && state != ODEBUG_STATE_NONE) {
913 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
914 goto out;
915 }
916 if (obj && obj->state != state) {
917 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
918 obj->state, state);
919 goto out;
920 }
921 if (fixups != debug_objects_fixups) {
922 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
923 fixups, debug_objects_fixups);
924 goto out;
925 }
926 if (warnings != debug_objects_warnings) {
927 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
928 warnings, debug_objects_warnings);
929 goto out;
930 }
931 res = 0;
932out:
933 raw_spin_unlock_irqrestore(&db->lock, flags);
934 if (res)
935 debug_objects_enabled = 0;
936 return res;
937}
938
939static __initdata struct debug_obj_descr descr_type_test = {
940 .name = "selftest",
941 .is_static_object = is_static_object,
942 .fixup_init = fixup_init,
943 .fixup_activate = fixup_activate,
944 .fixup_destroy = fixup_destroy,
945 .fixup_free = fixup_free,
946};
947
948static __initdata struct self_test obj = { .static_init = 0 };
949
950static void __init debug_objects_selftest(void)
951{
952 int fixups, oldfixups, warnings, oldwarnings;
953 unsigned long flags;
954
955 local_irq_save(flags);
956
957 fixups = oldfixups = debug_objects_fixups;
958 warnings = oldwarnings = debug_objects_warnings;
959 descr_test = &descr_type_test;
960
961 debug_object_init(&obj, &descr_type_test);
962 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
963 goto out;
964 debug_object_activate(&obj, &descr_type_test);
965 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
966 goto out;
967 debug_object_activate(&obj, &descr_type_test);
968 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
969 goto out;
970 debug_object_deactivate(&obj, &descr_type_test);
971 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
972 goto out;
973 debug_object_destroy(&obj, &descr_type_test);
974 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
975 goto out;
976 debug_object_init(&obj, &descr_type_test);
977 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
978 goto out;
979 debug_object_activate(&obj, &descr_type_test);
980 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
981 goto out;
982 debug_object_deactivate(&obj, &descr_type_test);
983 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
984 goto out;
985 debug_object_free(&obj, &descr_type_test);
986 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
987 goto out;
988
989 obj.static_init = 1;
990 debug_object_activate(&obj, &descr_type_test);
991 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
992 goto out;
993 debug_object_init(&obj, &descr_type_test);
994 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
995 goto out;
996 debug_object_free(&obj, &descr_type_test);
997 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
998 goto out;
999
1000#ifdef CONFIG_DEBUG_OBJECTS_FREE
1001 debug_object_init(&obj, &descr_type_test);
1002 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1003 goto out;
1004 debug_object_activate(&obj, &descr_type_test);
1005 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1006 goto out;
1007 __debug_check_no_obj_freed(&obj, sizeof(obj));
1008 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1009 goto out;
1010#endif
1011 pr_info("selftest passed\n");
1012
1013out:
1014 debug_objects_fixups = oldfixups;
1015 debug_objects_warnings = oldwarnings;
1016 descr_test = NULL;
1017
1018 local_irq_restore(flags);
1019}
1020#else
1021static inline void debug_objects_selftest(void) { }
1022#endif
1023
1024/*
1025 * Called during early boot to initialize the hash buckets and link
1026 * the static object pool objects into the poll list. After this call
1027 * the object tracker is fully operational.
1028 */
1029void __init debug_objects_early_init(void)
1030{
1031 int i;
1032
1033 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1034 raw_spin_lock_init(&obj_hash[i].lock);
1035
1036 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1037 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1038}
1039
1040/*
1041 * Convert the statically allocated objects to dynamic ones:
1042 */
1043static int __init debug_objects_replace_static_objects(void)
1044{
1045 struct debug_bucket *db = obj_hash;
1046 struct hlist_node *tmp;
1047 struct debug_obj *obj, *new;
1048 HLIST_HEAD(objects);
1049 int i, cnt = 0;
1050
1051 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1052 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1053 if (!obj)
1054 goto free;
1055 hlist_add_head(&obj->node, &objects);
1056 }
1057
1058 /*
1059 * When debug_objects_mem_init() is called we know that only
1060 * one CPU is up, so disabling interrupts is enough
1061 * protection. This avoids the lockdep hell of lock ordering.
1062 */
1063 local_irq_disable();
1064
1065 /* Remove the statically allocated objects from the pool */
1066 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1067 hlist_del(&obj->node);
1068 /* Move the allocated objects to the pool */
1069 hlist_move_list(&objects, &obj_pool);
1070
1071 /* Replace the active object references */
1072 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1073 hlist_move_list(&db->list, &objects);
1074
1075 hlist_for_each_entry(obj, &objects, node) {
1076 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1077 hlist_del(&new->node);
1078 /* copy object data */
1079 *new = *obj;
1080 hlist_add_head(&new->node, &db->list);
1081 cnt++;
1082 }
1083 }
1084 local_irq_enable();
1085
1086 pr_debug("%d of %d active objects replaced\n",
1087 cnt, obj_pool_used);
1088 return 0;
1089free:
1090 hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1091 hlist_del(&obj->node);
1092 kmem_cache_free(obj_cache, obj);
1093 }
1094 return -ENOMEM;
1095}
1096
1097/*
1098 * Called after the kmem_caches are functional to setup a dedicated
1099 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1100 * prevents that the debug code is called on kmem_cache_free() for the
1101 * debug tracker objects to avoid recursive calls.
1102 */
1103void __init debug_objects_mem_init(void)
1104{
1105 if (!debug_objects_enabled)
1106 return;
1107
1108 obj_cache = kmem_cache_create("debug_objects_cache",
1109 sizeof (struct debug_obj), 0,
1110 SLAB_DEBUG_OBJECTS, NULL);
1111
1112 if (!obj_cache || debug_objects_replace_static_objects()) {
1113 debug_objects_enabled = 0;
1114 if (obj_cache)
1115 kmem_cache_destroy(obj_cache);
1116 pr_warn("out of memory.\n");
1117 } else
1118 debug_objects_selftest();
1119}