projects/linux·blob v4.6-rc6 · refs

1097 lines · 26.1 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 = keventd_up();
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 int
273debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
274 void * addr, enum debug_obj_state state)
275{
276 int fixed = 0;
277
278 if (fixup)
279 fixed = fixup(addr, state);
280 debug_objects_fixups += fixed;
281 return fixed;
282}
283
284static void debug_object_is_on_stack(void *addr, int onstack)
285{
286 int is_on_stack;
287 static int limit;
288
289 if (limit > 4)
290 return;
291
292 is_on_stack = object_is_on_stack(addr);
293 if (is_on_stack == onstack)
294 return;
295
296 limit++;
297 if (is_on_stack)
298 pr_warn("object is on stack, but not annotated\n");
299 else
300 pr_warn("object is not on stack, but annotated\n");
301 WARN_ON(1);
302}
303
304static void
305__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
306{
307 enum debug_obj_state state;
308 struct debug_bucket *db;
309 struct debug_obj *obj;
310 unsigned long flags;
311
312 fill_pool();
313
314 db = get_bucket((unsigned long) addr);
315
316 raw_spin_lock_irqsave(&db->lock, flags);
317
318 obj = lookup_object(addr, db);
319 if (!obj) {
320 obj = alloc_object(addr, db, descr);
321 if (!obj) {
322 debug_objects_enabled = 0;
323 raw_spin_unlock_irqrestore(&db->lock, flags);
324 debug_objects_oom();
325 return;
326 }
327 debug_object_is_on_stack(addr, onstack);
328 }
329
330 switch (obj->state) {
331 case ODEBUG_STATE_NONE:
332 case ODEBUG_STATE_INIT:
333 case ODEBUG_STATE_INACTIVE:
334 obj->state = ODEBUG_STATE_INIT;
335 break;
336
337 case ODEBUG_STATE_ACTIVE:
338 debug_print_object(obj, "init");
339 state = obj->state;
340 raw_spin_unlock_irqrestore(&db->lock, flags);
341 debug_object_fixup(descr->fixup_init, addr, state);
342 return;
343
344 case ODEBUG_STATE_DESTROYED:
345 debug_print_object(obj, "init");
346 break;
347 default:
348 break;
349 }
350
351 raw_spin_unlock_irqrestore(&db->lock, flags);
352}
353
354/**
355 * debug_object_init - debug checks when an object is initialized
356 * @addr: address of the object
357 * @descr: pointer to an object specific debug description structure
358 */
359void debug_object_init(void *addr, struct debug_obj_descr *descr)
360{
361 if (!debug_objects_enabled)
362 return;
363
364 __debug_object_init(addr, descr, 0);
365}
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}
380
381/**
382 * debug_object_activate - debug checks when an object is activated
383 * @addr: address of the object
384 * @descr: pointer to an object specific debug description structure
385 * Returns 0 for success, -EINVAL for check failed.
386 */
387int debug_object_activate(void *addr, struct debug_obj_descr *descr)
388{
389 enum debug_obj_state state;
390 struct debug_bucket *db;
391 struct debug_obj *obj;
392 unsigned long flags;
393 int ret;
394 struct debug_obj o = { .object = addr,
395 .state = ODEBUG_STATE_NOTAVAILABLE,
396 .descr = descr };
397
398 if (!debug_objects_enabled)
399 return 0;
400
401 db = get_bucket((unsigned long) addr);
402
403 raw_spin_lock_irqsave(&db->lock, flags);
404
405 obj = lookup_object(addr, db);
406 if (obj) {
407 switch (obj->state) {
408 case ODEBUG_STATE_INIT:
409 case ODEBUG_STATE_INACTIVE:
410 obj->state = ODEBUG_STATE_ACTIVE;
411 ret = 0;
412 break;
413
414 case ODEBUG_STATE_ACTIVE:
415 debug_print_object(obj, "activate");
416 state = obj->state;
417 raw_spin_unlock_irqrestore(&db->lock, flags);
418 ret = debug_object_fixup(descr->fixup_activate, addr, state);
419 return ret ? -EINVAL : 0;
420
421 case ODEBUG_STATE_DESTROYED:
422 debug_print_object(obj, "activate");
423 ret = -EINVAL;
424 break;
425 default:
426 ret = 0;
427 break;
428 }
429 raw_spin_unlock_irqrestore(&db->lock, flags);
430 return ret;
431 }
432
433 raw_spin_unlock_irqrestore(&db->lock, flags);
434 /*
435 * This happens when a static object is activated. We
436 * let the type specific code decide whether this is
437 * true or not.
438 */
439 if (debug_object_fixup(descr->fixup_activate, addr,
440 ODEBUG_STATE_NOTAVAILABLE)) {
441 debug_print_object(&o, "activate");
442 return -EINVAL;
443 }
444 return 0;
445}
446
447/**
448 * debug_object_deactivate - debug checks when an object is deactivated
449 * @addr: address of the object
450 * @descr: pointer to an object specific debug description structure
451 */
452void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
453{
454 struct debug_bucket *db;
455 struct debug_obj *obj;
456 unsigned long flags;
457
458 if (!debug_objects_enabled)
459 return;
460
461 db = get_bucket((unsigned long) addr);
462
463 raw_spin_lock_irqsave(&db->lock, flags);
464
465 obj = lookup_object(addr, db);
466 if (obj) {
467 switch (obj->state) {
468 case ODEBUG_STATE_INIT:
469 case ODEBUG_STATE_INACTIVE:
470 case ODEBUG_STATE_ACTIVE:
471 if (!obj->astate)
472 obj->state = ODEBUG_STATE_INACTIVE;
473 else
474 debug_print_object(obj, "deactivate");
475 break;
476
477 case ODEBUG_STATE_DESTROYED:
478 debug_print_object(obj, "deactivate");
479 break;
480 default:
481 break;
482 }
483 } else {
484 struct debug_obj o = { .object = addr,
485 .state = ODEBUG_STATE_NOTAVAILABLE,
486 .descr = descr };
487
488 debug_print_object(&o, "deactivate");
489 }
490
491 raw_spin_unlock_irqrestore(&db->lock, flags);
492}
493
494/**
495 * debug_object_destroy - debug checks when an object is destroyed
496 * @addr: address of the object
497 * @descr: pointer to an object specific debug description structure
498 */
499void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
500{
501 enum debug_obj_state state;
502 struct debug_bucket *db;
503 struct debug_obj *obj;
504 unsigned long flags;
505
506 if (!debug_objects_enabled)
507 return;
508
509 db = get_bucket((unsigned long) addr);
510
511 raw_spin_lock_irqsave(&db->lock, flags);
512
513 obj = lookup_object(addr, db);
514 if (!obj)
515 goto out_unlock;
516
517 switch (obj->state) {
518 case ODEBUG_STATE_NONE:
519 case ODEBUG_STATE_INIT:
520 case ODEBUG_STATE_INACTIVE:
521 obj->state = ODEBUG_STATE_DESTROYED;
522 break;
523 case ODEBUG_STATE_ACTIVE:
524 debug_print_object(obj, "destroy");
525 state = obj->state;
526 raw_spin_unlock_irqrestore(&db->lock, flags);
527 debug_object_fixup(descr->fixup_destroy, addr, state);
528 return;
529
530 case ODEBUG_STATE_DESTROYED:
531 debug_print_object(obj, "destroy");
532 break;
533 default:
534 break;
535 }
536out_unlock:
537 raw_spin_unlock_irqrestore(&db->lock, flags);
538}
539
540/**
541 * debug_object_free - debug checks when an object is freed
542 * @addr: address of the object
543 * @descr: pointer to an object specific debug description structure
544 */
545void debug_object_free(void *addr, struct debug_obj_descr *descr)
546{
547 enum debug_obj_state state;
548 struct debug_bucket *db;
549 struct debug_obj *obj;
550 unsigned long flags;
551
552 if (!debug_objects_enabled)
553 return;
554
555 db = get_bucket((unsigned long) addr);
556
557 raw_spin_lock_irqsave(&db->lock, flags);
558
559 obj = lookup_object(addr, db);
560 if (!obj)
561 goto out_unlock;
562
563 switch (obj->state) {
564 case ODEBUG_STATE_ACTIVE:
565 debug_print_object(obj, "free");
566 state = obj->state;
567 raw_spin_unlock_irqrestore(&db->lock, flags);
568 debug_object_fixup(descr->fixup_free, addr, state);
569 return;
570 default:
571 hlist_del(&obj->node);
572 raw_spin_unlock_irqrestore(&db->lock, flags);
573 free_object(obj);
574 return;
575 }
576out_unlock:
577 raw_spin_unlock_irqrestore(&db->lock, flags);
578}
579
580/**
581 * debug_object_assert_init - debug checks when object should be init-ed
582 * @addr: address of the object
583 * @descr: pointer to an object specific debug description structure
584 */
585void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
586{
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 struct debug_obj o = { .object = addr,
601 .state = ODEBUG_STATE_NOTAVAILABLE,
602 .descr = descr };
603
604 raw_spin_unlock_irqrestore(&db->lock, flags);
605 /*
606 * Maybe the object is static. Let the type specific
607 * code decide what to do.
608 */
609 if (debug_object_fixup(descr->fixup_assert_init, addr,
610 ODEBUG_STATE_NOTAVAILABLE))
611 debug_print_object(&o, "assert_init");
612 return;
613 }
614
615 raw_spin_unlock_irqrestore(&db->lock, flags);
616}
617
618/**
619 * debug_object_active_state - debug checks object usage state machine
620 * @addr: address of the object
621 * @descr: pointer to an object specific debug description structure
622 * @expect: expected state
623 * @next: state to move to if expected state is found
624 */
625void
626debug_object_active_state(void *addr, struct debug_obj_descr *descr,
627 unsigned int expect, unsigned int next)
628{
629 struct debug_bucket *db;
630 struct debug_obj *obj;
631 unsigned long flags;
632
633 if (!debug_objects_enabled)
634 return;
635
636 db = get_bucket((unsigned long) addr);
637
638 raw_spin_lock_irqsave(&db->lock, flags);
639
640 obj = lookup_object(addr, db);
641 if (obj) {
642 switch (obj->state) {
643 case ODEBUG_STATE_ACTIVE:
644 if (obj->astate == expect)
645 obj->astate = next;
646 else
647 debug_print_object(obj, "active_state");
648 break;
649
650 default:
651 debug_print_object(obj, "active_state");
652 break;
653 }
654 } else {
655 struct debug_obj o = { .object = addr,
656 .state = ODEBUG_STATE_NOTAVAILABLE,
657 .descr = descr };
658
659 debug_print_object(&o, "active_state");
660 }
661
662 raw_spin_unlock_irqrestore(&db->lock, flags);
663}
664
665#ifdef CONFIG_DEBUG_OBJECTS_FREE
666static void __debug_check_no_obj_freed(const void *address, unsigned long size)
667{
668 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
669 struct hlist_node *tmp;
670 HLIST_HEAD(freelist);
671 struct debug_obj_descr *descr;
672 enum debug_obj_state state;
673 struct debug_bucket *db;
674 struct debug_obj *obj;
675 int cnt;
676
677 saddr = (unsigned long) address;
678 eaddr = saddr + size;
679 paddr = saddr & ODEBUG_CHUNK_MASK;
680 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
681 chunks >>= ODEBUG_CHUNK_SHIFT;
682
683 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
684 db = get_bucket(paddr);
685
686repeat:
687 cnt = 0;
688 raw_spin_lock_irqsave(&db->lock, flags);
689 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
690 cnt++;
691 oaddr = (unsigned long) obj->object;
692 if (oaddr < saddr || oaddr >= eaddr)
693 continue;
694
695 switch (obj->state) {
696 case ODEBUG_STATE_ACTIVE:
697 debug_print_object(obj, "free");
698 descr = obj->descr;
699 state = obj->state;
700 raw_spin_unlock_irqrestore(&db->lock, flags);
701 debug_object_fixup(descr->fixup_free,
702 (void *) oaddr, state);
703 goto repeat;
704 default:
705 hlist_del(&obj->node);
706 hlist_add_head(&obj->node, &freelist);
707 break;
708 }
709 }
710 raw_spin_unlock_irqrestore(&db->lock, flags);
711
712 /* Now free them */
713 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
714 hlist_del(&obj->node);
715 free_object(obj);
716 }
717
718 if (cnt > debug_objects_maxchain)
719 debug_objects_maxchain = cnt;
720 }
721}
722
723void debug_check_no_obj_freed(const void *address, unsigned long size)
724{
725 if (debug_objects_enabled)
726 __debug_check_no_obj_freed(address, size);
727}
728#endif
729
730#ifdef CONFIG_DEBUG_FS
731
732static int debug_stats_show(struct seq_file *m, void *v)
733{
734 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
735 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
736 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
737 seq_printf(m, "pool_free :%d\n", obj_pool_free);
738 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
739 seq_printf(m, "pool_used :%d\n", obj_pool_used);
740 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
741 return 0;
742}
743
744static int debug_stats_open(struct inode *inode, struct file *filp)
745{
746 return single_open(filp, debug_stats_show, NULL);
747}
748
749static const struct file_operations debug_stats_fops = {
750 .open = debug_stats_open,
751 .read = seq_read,
752 .llseek = seq_lseek,
753 .release = single_release,
754};
755
756static int __init debug_objects_init_debugfs(void)
757{
758 struct dentry *dbgdir, *dbgstats;
759
760 if (!debug_objects_enabled)
761 return 0;
762
763 dbgdir = debugfs_create_dir("debug_objects", NULL);
764 if (!dbgdir)
765 return -ENOMEM;
766
767 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
768 &debug_stats_fops);
769 if (!dbgstats)
770 goto err;
771
772 return 0;
773
774err:
775 debugfs_remove(dbgdir);
776
777 return -ENOMEM;
778}
779__initcall(debug_objects_init_debugfs);
780
781#else
782static inline void debug_objects_init_debugfs(void) { }
783#endif
784
785#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
786
787/* Random data structure for the self test */
788struct self_test {
789 unsigned long dummy1[6];
790 int static_init;
791 unsigned long dummy2[3];
792};
793
794static __initdata struct debug_obj_descr descr_type_test;
795
796/*
797 * fixup_init is called when:
798 * - an active object is initialized
799 */
800static int __init fixup_init(void *addr, enum debug_obj_state state)
801{
802 struct self_test *obj = addr;
803
804 switch (state) {
805 case ODEBUG_STATE_ACTIVE:
806 debug_object_deactivate(obj, &descr_type_test);
807 debug_object_init(obj, &descr_type_test);
808 return 1;
809 default:
810 return 0;
811 }
812}
813
814/*
815 * fixup_activate is called when:
816 * - an active object is activated
817 * - an unknown object is activated (might be a statically initialized object)
818 */
819static int __init fixup_activate(void *addr, enum debug_obj_state state)
820{
821 struct self_test *obj = addr;
822
823 switch (state) {
824 case ODEBUG_STATE_NOTAVAILABLE:
825 if (obj->static_init == 1) {
826 debug_object_init(obj, &descr_type_test);
827 debug_object_activate(obj, &descr_type_test);
828 return 0;
829 }
830 return 1;
831
832 case ODEBUG_STATE_ACTIVE:
833 debug_object_deactivate(obj, &descr_type_test);
834 debug_object_activate(obj, &descr_type_test);
835 return 1;
836
837 default:
838 return 0;
839 }
840}
841
842/*
843 * fixup_destroy is called when:
844 * - an active object is destroyed
845 */
846static int __init fixup_destroy(void *addr, enum debug_obj_state state)
847{
848 struct self_test *obj = addr;
849
850 switch (state) {
851 case ODEBUG_STATE_ACTIVE:
852 debug_object_deactivate(obj, &descr_type_test);
853 debug_object_destroy(obj, &descr_type_test);
854 return 1;
855 default:
856 return 0;
857 }
858}
859
860/*
861 * fixup_free is called when:
862 * - an active object is freed
863 */
864static int __init fixup_free(void *addr, enum debug_obj_state state)
865{
866 struct self_test *obj = addr;
867
868 switch (state) {
869 case ODEBUG_STATE_ACTIVE:
870 debug_object_deactivate(obj, &descr_type_test);
871 debug_object_free(obj, &descr_type_test);
872 return 1;
873 default:
874 return 0;
875 }
876}
877
878static int __init
879check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
880{
881 struct debug_bucket *db;
882 struct debug_obj *obj;
883 unsigned long flags;
884 int res = -EINVAL;
885
886 db = get_bucket((unsigned long) addr);
887
888 raw_spin_lock_irqsave(&db->lock, flags);
889
890 obj = lookup_object(addr, db);
891 if (!obj && state != ODEBUG_STATE_NONE) {
892 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
893 goto out;
894 }
895 if (obj && obj->state != state) {
896 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
897 obj->state, state);
898 goto out;
899 }
900 if (fixups != debug_objects_fixups) {
901 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
902 fixups, debug_objects_fixups);
903 goto out;
904 }
905 if (warnings != debug_objects_warnings) {
906 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
907 warnings, debug_objects_warnings);
908 goto out;
909 }
910 res = 0;
911out:
912 raw_spin_unlock_irqrestore(&db->lock, flags);
913 if (res)
914 debug_objects_enabled = 0;
915 return res;
916}
917
918static __initdata struct debug_obj_descr descr_type_test = {
919 .name = "selftest",
920 .fixup_init = fixup_init,
921 .fixup_activate = fixup_activate,
922 .fixup_destroy = fixup_destroy,
923 .fixup_free = fixup_free,
924};
925
926static __initdata struct self_test obj = { .static_init = 0 };
927
928static void __init debug_objects_selftest(void)
929{
930 int fixups, oldfixups, warnings, oldwarnings;
931 unsigned long flags;
932
933 local_irq_save(flags);
934
935 fixups = oldfixups = debug_objects_fixups;
936 warnings = oldwarnings = debug_objects_warnings;
937 descr_test = &descr_type_test;
938
939 debug_object_init(&obj, &descr_type_test);
940 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
941 goto out;
942 debug_object_activate(&obj, &descr_type_test);
943 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
944 goto out;
945 debug_object_activate(&obj, &descr_type_test);
946 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
947 goto out;
948 debug_object_deactivate(&obj, &descr_type_test);
949 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
950 goto out;
951 debug_object_destroy(&obj, &descr_type_test);
952 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
953 goto out;
954 debug_object_init(&obj, &descr_type_test);
955 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
956 goto out;
957 debug_object_activate(&obj, &descr_type_test);
958 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
959 goto out;
960 debug_object_deactivate(&obj, &descr_type_test);
961 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
962 goto out;
963 debug_object_free(&obj, &descr_type_test);
964 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
965 goto out;
966
967 obj.static_init = 1;
968 debug_object_activate(&obj, &descr_type_test);
969 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
970 goto out;
971 debug_object_init(&obj, &descr_type_test);
972 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
973 goto out;
974 debug_object_free(&obj, &descr_type_test);
975 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
976 goto out;
977
978#ifdef CONFIG_DEBUG_OBJECTS_FREE
979 debug_object_init(&obj, &descr_type_test);
980 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
981 goto out;
982 debug_object_activate(&obj, &descr_type_test);
983 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
984 goto out;
985 __debug_check_no_obj_freed(&obj, sizeof(obj));
986 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
987 goto out;
988#endif
989 pr_info("selftest passed\n");
990
991out:
992 debug_objects_fixups = oldfixups;
993 debug_objects_warnings = oldwarnings;
994 descr_test = NULL;
995
996 local_irq_restore(flags);
997}
998#else
999static inline void debug_objects_selftest(void) { }
1000#endif
1001
1002/*
1003 * Called during early boot to initialize the hash buckets and link
1004 * the static object pool objects into the poll list. After this call
1005 * the object tracker is fully operational.
1006 */
1007void __init debug_objects_early_init(void)
1008{
1009 int i;
1010
1011 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1012 raw_spin_lock_init(&obj_hash[i].lock);
1013
1014 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1015 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1016}
1017
1018/*
1019 * Convert the statically allocated objects to dynamic ones:
1020 */
1021static int __init debug_objects_replace_static_objects(void)
1022{
1023 struct debug_bucket *db = obj_hash;
1024 struct hlist_node *tmp;
1025 struct debug_obj *obj, *new;
1026 HLIST_HEAD(objects);
1027 int i, cnt = 0;
1028
1029 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1030 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1031 if (!obj)
1032 goto free;
1033 hlist_add_head(&obj->node, &objects);
1034 }
1035
1036 /*
1037 * When debug_objects_mem_init() is called we know that only
1038 * one CPU is up, so disabling interrupts is enough
1039 * protection. This avoids the lockdep hell of lock ordering.
1040 */
1041 local_irq_disable();
1042
1043 /* Remove the statically allocated objects from the pool */
1044 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1045 hlist_del(&obj->node);
1046 /* Move the allocated objects to the pool */
1047 hlist_move_list(&objects, &obj_pool);
1048
1049 /* Replace the active object references */
1050 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1051 hlist_move_list(&db->list, &objects);
1052
1053 hlist_for_each_entry(obj, &objects, node) {
1054 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1055 hlist_del(&new->node);
1056 /* copy object data */
1057 *new = *obj;
1058 hlist_add_head(&new->node, &db->list);
1059 cnt++;
1060 }
1061 }
1062 local_irq_enable();
1063
1064 pr_debug("%d of %d active objects replaced\n",
1065 cnt, obj_pool_used);
1066 return 0;
1067free:
1068 hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1069 hlist_del(&obj->node);
1070 kmem_cache_free(obj_cache, obj);
1071 }
1072 return -ENOMEM;
1073}
1074
1075/*
1076 * Called after the kmem_caches are functional to setup a dedicated
1077 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1078 * prevents that the debug code is called on kmem_cache_free() for the
1079 * debug tracker objects to avoid recursive calls.
1080 */
1081void __init debug_objects_mem_init(void)
1082{
1083 if (!debug_objects_enabled)
1084 return;
1085
1086 obj_cache = kmem_cache_create("debug_objects_cache",
1087 sizeof (struct debug_obj), 0,
1088 SLAB_DEBUG_OBJECTS, NULL);
1089
1090 if (!obj_cache || debug_objects_replace_static_objects()) {
1091 debug_objects_enabled = 0;
1092 if (obj_cache)
1093 kmem_cache_destroy(obj_cache);
1094 pr_warn("out of memory.\n");
1095 } else
1096 debug_objects_selftest();
1097}