projects/linux·blob v3.12 · refs

1096 lines · 26.2 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#include <linux/debugobjects.h>
11#include <linux/interrupt.h>
12#include <linux/sched.h>
13#include <linux/seq_file.h>
14#include <linux/debugfs.h>
15#include <linux/slab.h>
16#include <linux/hash.h>
17
18#define ODEBUG_HASH_BITS 14
19#define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
20
21#define ODEBUG_POOL_SIZE 512
22#define ODEBUG_POOL_MIN_LEVEL 256
23
24#define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
25#define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
26#define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
27
28struct debug_bucket {
29 struct hlist_head list;
30 raw_spinlock_t lock;
31};
32
33static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
34
35static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
36
37static DEFINE_RAW_SPINLOCK(pool_lock);
38
39static HLIST_HEAD(obj_pool);
40
41static int obj_pool_min_free = ODEBUG_POOL_SIZE;
42static int obj_pool_free = ODEBUG_POOL_SIZE;
43static int obj_pool_used;
44static int obj_pool_max_used;
45static struct kmem_cache *obj_cache;
46
47static int debug_objects_maxchain __read_mostly;
48static int debug_objects_fixups __read_mostly;
49static int debug_objects_warnings __read_mostly;
50static int debug_objects_enabled __read_mostly
51 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
52
53static struct debug_obj_descr *descr_test __read_mostly;
54
55static void free_obj_work(struct work_struct *work);
56static DECLARE_WORK(debug_obj_work, free_obj_work);
57
58static int __init enable_object_debug(char *str)
59{
60 debug_objects_enabled = 1;
61 return 0;
62}
63
64static int __init disable_object_debug(char *str)
65{
66 debug_objects_enabled = 0;
67 return 0;
68}
69
70early_param("debug_objects", enable_object_debug);
71early_param("no_debug_objects", disable_object_debug);
72
73static const char *obj_states[ODEBUG_STATE_MAX] = {
74 [ODEBUG_STATE_NONE] = "none",
75 [ODEBUG_STATE_INIT] = "initialized",
76 [ODEBUG_STATE_INACTIVE] = "inactive",
77 [ODEBUG_STATE_ACTIVE] = "active",
78 [ODEBUG_STATE_DESTROYED] = "destroyed",
79 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
80};
81
82static void fill_pool(void)
83{
84 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
85 struct debug_obj *new;
86 unsigned long flags;
87
88 if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
89 return;
90
91 if (unlikely(!obj_cache))
92 return;
93
94 while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
95
96 new = kmem_cache_zalloc(obj_cache, gfp);
97 if (!new)
98 return;
99
100 raw_spin_lock_irqsave(&pool_lock, flags);
101 hlist_add_head(&new->node, &obj_pool);
102 obj_pool_free++;
103 raw_spin_unlock_irqrestore(&pool_lock, flags);
104 }
105}
106
107/*
108 * Lookup an object in the hash bucket.
109 */
110static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
111{
112 struct debug_obj *obj;
113 int cnt = 0;
114
115 hlist_for_each_entry(obj, &b->list, node) {
116 cnt++;
117 if (obj->object == addr)
118 return obj;
119 }
120 if (cnt > debug_objects_maxchain)
121 debug_objects_maxchain = cnt;
122
123 return NULL;
124}
125
126/*
127 * Allocate a new object. If the pool is empty, switch off the debugger.
128 * Must be called with interrupts disabled.
129 */
130static struct debug_obj *
131alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
132{
133 struct debug_obj *obj = NULL;
134
135 raw_spin_lock(&pool_lock);
136 if (obj_pool.first) {
137 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
138
139 obj->object = addr;
140 obj->descr = descr;
141 obj->state = ODEBUG_STATE_NONE;
142 obj->astate = 0;
143 hlist_del(&obj->node);
144
145 hlist_add_head(&obj->node, &b->list);
146
147 obj_pool_used++;
148 if (obj_pool_used > obj_pool_max_used)
149 obj_pool_max_used = obj_pool_used;
150
151 obj_pool_free--;
152 if (obj_pool_free < obj_pool_min_free)
153 obj_pool_min_free = obj_pool_free;
154 }
155 raw_spin_unlock(&pool_lock);
156
157 return obj;
158}
159
160/*
161 * workqueue function to free objects.
162 */
163static void free_obj_work(struct work_struct *work)
164{
165 struct debug_obj *obj;
166 unsigned long flags;
167
168 raw_spin_lock_irqsave(&pool_lock, flags);
169 while (obj_pool_free > ODEBUG_POOL_SIZE) {
170 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
171 hlist_del(&obj->node);
172 obj_pool_free--;
173 /*
174 * We release pool_lock across kmem_cache_free() to
175 * avoid contention on pool_lock.
176 */
177 raw_spin_unlock_irqrestore(&pool_lock, flags);
178 kmem_cache_free(obj_cache, obj);
179 raw_spin_lock_irqsave(&pool_lock, flags);
180 }
181 raw_spin_unlock_irqrestore(&pool_lock, flags);
182}
183
184/*
185 * Put the object back into the pool and schedule work to free objects
186 * if necessary.
187 */
188static void free_object(struct debug_obj *obj)
189{
190 unsigned long flags;
191 int sched = 0;
192
193 raw_spin_lock_irqsave(&pool_lock, flags);
194 /*
195 * schedule work when the pool is filled and the cache is
196 * initialized:
197 */
198 if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache)
199 sched = keventd_up() && !work_pending(&debug_obj_work);
200 hlist_add_head(&obj->node, &obj_pool);
201 obj_pool_free++;
202 obj_pool_used--;
203 raw_spin_unlock_irqrestore(&pool_lock, flags);
204 if (sched)
205 schedule_work(&debug_obj_work);
206}
207
208/*
209 * We run out of memory. That means we probably have tons of objects
210 * allocated.
211 */
212static void debug_objects_oom(void)
213{
214 struct debug_bucket *db = obj_hash;
215 struct hlist_node *tmp;
216 HLIST_HEAD(freelist);
217 struct debug_obj *obj;
218 unsigned long flags;
219 int i;
220
221 printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
222
223 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
224 raw_spin_lock_irqsave(&db->lock, flags);
225 hlist_move_list(&db->list, &freelist);
226 raw_spin_unlock_irqrestore(&db->lock, flags);
227
228 /* Now free them */
229 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
230 hlist_del(&obj->node);
231 free_object(obj);
232 }
233 }
234}
235
236/*
237 * We use the pfn of the address for the hash. That way we can check
238 * for freed objects simply by checking the affected bucket.
239 */
240static struct debug_bucket *get_bucket(unsigned long addr)
241{
242 unsigned long hash;
243
244 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
245 return &obj_hash[hash];
246}
247
248static void debug_print_object(struct debug_obj *obj, char *msg)
249{
250 struct debug_obj_descr *descr = obj->descr;
251 static int limit;
252
253 if (limit < 5 && descr != descr_test) {
254 void *hint = descr->debug_hint ?
255 descr->debug_hint(obj->object) : NULL;
256 limit++;
257 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
258 "object type: %s hint: %pS\n",
259 msg, obj_states[obj->state], obj->astate,
260 descr->name, hint);
261 }
262 debug_objects_warnings++;
263}
264
265/*
266 * Try to repair the damage, so we have a better chance to get useful
267 * debug output.
268 */
269static int
270debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
271 void * addr, enum debug_obj_state state)
272{
273 int fixed = 0;
274
275 if (fixup)
276 fixed = fixup(addr, state);
277 debug_objects_fixups += fixed;
278 return fixed;
279}
280
281static void debug_object_is_on_stack(void *addr, int onstack)
282{
283 int is_on_stack;
284 static int limit;
285
286 if (limit > 4)
287 return;
288
289 is_on_stack = object_is_on_stack(addr);
290 if (is_on_stack == onstack)
291 return;
292
293 limit++;
294 if (is_on_stack)
295 printk(KERN_WARNING
296 "ODEBUG: object is on stack, but not annotated\n");
297 else
298 printk(KERN_WARNING
299 "ODEBUG: 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}
365
366/**
367 * debug_object_init_on_stack - debug checks when an object on stack is
368 * initialized
369 * @addr: address of the object
370 * @descr: pointer to an object specific debug description structure
371 */
372void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
373{
374 if (!debug_objects_enabled)
375 return;
376
377 __debug_object_init(addr, descr, 1);
378}
379
380/**
381 * debug_object_activate - debug checks when an object is activated
382 * @addr: address of the object
383 * @descr: pointer to an object specific debug description structure
384 * Returns 0 for success, -EINVAL for check failed.
385 */
386int debug_object_activate(void *addr, struct debug_obj_descr *descr)
387{
388 enum debug_obj_state state;
389 struct debug_bucket *db;
390 struct debug_obj *obj;
391 unsigned long flags;
392 int ret;
393 struct debug_obj o = { .object = addr,
394 .state = ODEBUG_STATE_NOTAVAILABLE,
395 .descr = descr };
396
397 if (!debug_objects_enabled)
398 return 0;
399
400 db = get_bucket((unsigned long) addr);
401
402 raw_spin_lock_irqsave(&db->lock, flags);
403
404 obj = lookup_object(addr, db);
405 if (obj) {
406 switch (obj->state) {
407 case ODEBUG_STATE_INIT:
408 case ODEBUG_STATE_INACTIVE:
409 obj->state = ODEBUG_STATE_ACTIVE;
410 ret = 0;
411 break;
412
413 case ODEBUG_STATE_ACTIVE:
414 debug_print_object(obj, "activate");
415 state = obj->state;
416 raw_spin_unlock_irqrestore(&db->lock, flags);
417 ret = debug_object_fixup(descr->fixup_activate, addr, state);
418 return ret ? -EINVAL : 0;
419
420 case ODEBUG_STATE_DESTROYED:
421 debug_print_object(obj, "activate");
422 ret = -EINVAL;
423 break;
424 default:
425 ret = 0;
426 break;
427 }
428 raw_spin_unlock_irqrestore(&db->lock, flags);
429 return ret;
430 }
431
432 raw_spin_unlock_irqrestore(&db->lock, flags);
433 /*
434 * This happens when a static object is activated. We
435 * let the type specific code decide whether this is
436 * true or not.
437 */
438 if (debug_object_fixup(descr->fixup_activate, addr,
439 ODEBUG_STATE_NOTAVAILABLE)) {
440 debug_print_object(&o, "activate");
441 return -EINVAL;
442 }
443 return 0;
444}
445
446/**
447 * debug_object_deactivate - debug checks when an object is deactivated
448 * @addr: address of the object
449 * @descr: pointer to an object specific debug description structure
450 */
451void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
452{
453 struct debug_bucket *db;
454 struct debug_obj *obj;
455 unsigned long flags;
456
457 if (!debug_objects_enabled)
458 return;
459
460 db = get_bucket((unsigned long) addr);
461
462 raw_spin_lock_irqsave(&db->lock, flags);
463
464 obj = lookup_object(addr, db);
465 if (obj) {
466 switch (obj->state) {
467 case ODEBUG_STATE_INIT:
468 case ODEBUG_STATE_INACTIVE:
469 case ODEBUG_STATE_ACTIVE:
470 if (!obj->astate)
471 obj->state = ODEBUG_STATE_INACTIVE;
472 else
473 debug_print_object(obj, "deactivate");
474 break;
475
476 case ODEBUG_STATE_DESTROYED:
477 debug_print_object(obj, "deactivate");
478 break;
479 default:
480 break;
481 }
482 } else {
483 struct debug_obj o = { .object = addr,
484 .state = ODEBUG_STATE_NOTAVAILABLE,
485 .descr = descr };
486
487 debug_print_object(&o, "deactivate");
488 }
489
490 raw_spin_unlock_irqrestore(&db->lock, flags);
491}
492
493/**
494 * debug_object_destroy - debug checks when an object is destroyed
495 * @addr: address of the object
496 * @descr: pointer to an object specific debug description structure
497 */
498void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
499{
500 enum debug_obj_state state;
501 struct debug_bucket *db;
502 struct debug_obj *obj;
503 unsigned long flags;
504
505 if (!debug_objects_enabled)
506 return;
507
508 db = get_bucket((unsigned long) addr);
509
510 raw_spin_lock_irqsave(&db->lock, flags);
511
512 obj = lookup_object(addr, db);
513 if (!obj)
514 goto out_unlock;
515
516 switch (obj->state) {
517 case ODEBUG_STATE_NONE:
518 case ODEBUG_STATE_INIT:
519 case ODEBUG_STATE_INACTIVE:
520 obj->state = ODEBUG_STATE_DESTROYED;
521 break;
522 case ODEBUG_STATE_ACTIVE:
523 debug_print_object(obj, "destroy");
524 state = obj->state;
525 raw_spin_unlock_irqrestore(&db->lock, flags);
526 debug_object_fixup(descr->fixup_destroy, addr, state);
527 return;
528
529 case ODEBUG_STATE_DESTROYED:
530 debug_print_object(obj, "destroy");
531 break;
532 default:
533 break;
534 }
535out_unlock:
536 raw_spin_unlock_irqrestore(&db->lock, flags);
537}
538
539/**
540 * debug_object_free - debug checks when an object is freed
541 * @addr: address of the object
542 * @descr: pointer to an object specific debug description structure
543 */
544void debug_object_free(void *addr, struct debug_obj_descr *descr)
545{
546 enum debug_obj_state state;
547 struct debug_bucket *db;
548 struct debug_obj *obj;
549 unsigned long flags;
550
551 if (!debug_objects_enabled)
552 return;
553
554 db = get_bucket((unsigned long) addr);
555
556 raw_spin_lock_irqsave(&db->lock, flags);
557
558 obj = lookup_object(addr, db);
559 if (!obj)
560 goto out_unlock;
561
562 switch (obj->state) {
563 case ODEBUG_STATE_ACTIVE:
564 debug_print_object(obj, "free");
565 state = obj->state;
566 raw_spin_unlock_irqrestore(&db->lock, flags);
567 debug_object_fixup(descr->fixup_free, addr, state);
568 return;
569 default:
570 hlist_del(&obj->node);
571 raw_spin_unlock_irqrestore(&db->lock, flags);
572 free_object(obj);
573 return;
574 }
575out_unlock:
576 raw_spin_unlock_irqrestore(&db->lock, flags);
577}
578
579/**
580 * debug_object_assert_init - debug checks when object should be init-ed
581 * @addr: address of the object
582 * @descr: pointer to an object specific debug description structure
583 */
584void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
585{
586 struct debug_bucket *db;
587 struct debug_obj *obj;
588 unsigned long flags;
589
590 if (!debug_objects_enabled)
591 return;
592
593 db = get_bucket((unsigned long) addr);
594
595 raw_spin_lock_irqsave(&db->lock, flags);
596
597 obj = lookup_object(addr, db);
598 if (!obj) {
599 struct debug_obj o = { .object = addr,
600 .state = ODEBUG_STATE_NOTAVAILABLE,
601 .descr = descr };
602
603 raw_spin_unlock_irqrestore(&db->lock, flags);
604 /*
605 * Maybe the object is static. Let the type specific
606 * code decide what to do.
607 */
608 if (debug_object_fixup(descr->fixup_assert_init, addr,
609 ODEBUG_STATE_NOTAVAILABLE))
610 debug_print_object(&o, "assert_init");
611 return;
612 }
613
614 raw_spin_unlock_irqrestore(&db->lock, flags);
615}
616
617/**
618 * debug_object_active_state - debug checks object usage state machine
619 * @addr: address of the object
620 * @descr: pointer to an object specific debug description structure
621 * @expect: expected state
622 * @next: state to move to if expected state is found
623 */
624void
625debug_object_active_state(void *addr, struct debug_obj_descr *descr,
626 unsigned int expect, unsigned int next)
627{
628 struct debug_bucket *db;
629 struct debug_obj *obj;
630 unsigned long flags;
631
632 if (!debug_objects_enabled)
633 return;
634
635 db = get_bucket((unsigned long) addr);
636
637 raw_spin_lock_irqsave(&db->lock, flags);
638
639 obj = lookup_object(addr, db);
640 if (obj) {
641 switch (obj->state) {
642 case ODEBUG_STATE_ACTIVE:
643 if (obj->astate == expect)
644 obj->astate = next;
645 else
646 debug_print_object(obj, "active_state");
647 break;
648
649 default:
650 debug_print_object(obj, "active_state");
651 break;
652 }
653 } else {
654 struct debug_obj o = { .object = addr,
655 .state = ODEBUG_STATE_NOTAVAILABLE,
656 .descr = descr };
657
658 debug_print_object(&o, "active_state");
659 }
660
661 raw_spin_unlock_irqrestore(&db->lock, flags);
662}
663
664#ifdef CONFIG_DEBUG_OBJECTS_FREE
665static void __debug_check_no_obj_freed(const void *address, unsigned long size)
666{
667 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
668 struct hlist_node *tmp;
669 HLIST_HEAD(freelist);
670 struct debug_obj_descr *descr;
671 enum debug_obj_state state;
672 struct debug_bucket *db;
673 struct debug_obj *obj;
674 int cnt;
675
676 saddr = (unsigned long) address;
677 eaddr = saddr + size;
678 paddr = saddr & ODEBUG_CHUNK_MASK;
679 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
680 chunks >>= ODEBUG_CHUNK_SHIFT;
681
682 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
683 db = get_bucket(paddr);
684
685repeat:
686 cnt = 0;
687 raw_spin_lock_irqsave(&db->lock, flags);
688 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
689 cnt++;
690 oaddr = (unsigned long) obj->object;
691 if (oaddr < saddr || oaddr >= eaddr)
692 continue;
693
694 switch (obj->state) {
695 case ODEBUG_STATE_ACTIVE:
696 debug_print_object(obj, "free");
697 descr = obj->descr;
698 state = obj->state;
699 raw_spin_unlock_irqrestore(&db->lock, flags);
700 debug_object_fixup(descr->fixup_free,
701 (void *) oaddr, state);
702 goto repeat;
703 default:
704 hlist_del(&obj->node);
705 hlist_add_head(&obj->node, &freelist);
706 break;
707 }
708 }
709 raw_spin_unlock_irqrestore(&db->lock, flags);
710
711 /* Now free them */
712 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
713 hlist_del(&obj->node);
714 free_object(obj);
715 }
716
717 if (cnt > debug_objects_maxchain)
718 debug_objects_maxchain = cnt;
719 }
720}
721
722void debug_check_no_obj_freed(const void *address, unsigned long size)
723{
724 if (debug_objects_enabled)
725 __debug_check_no_obj_freed(address, size);
726}
727#endif
728
729#ifdef CONFIG_DEBUG_FS
730
731static int debug_stats_show(struct seq_file *m, void *v)
732{
733 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
734 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
735 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
736 seq_printf(m, "pool_free :%d\n", obj_pool_free);
737 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
738 seq_printf(m, "pool_used :%d\n", obj_pool_used);
739 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
740 return 0;
741}
742
743static int debug_stats_open(struct inode *inode, struct file *filp)
744{
745 return single_open(filp, debug_stats_show, NULL);
746}
747
748static const struct file_operations debug_stats_fops = {
749 .open = debug_stats_open,
750 .read = seq_read,
751 .llseek = seq_lseek,
752 .release = single_release,
753};
754
755static int __init debug_objects_init_debugfs(void)
756{
757 struct dentry *dbgdir, *dbgstats;
758
759 if (!debug_objects_enabled)
760 return 0;
761
762 dbgdir = debugfs_create_dir("debug_objects", NULL);
763 if (!dbgdir)
764 return -ENOMEM;
765
766 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
767 &debug_stats_fops);
768 if (!dbgstats)
769 goto err;
770
771 return 0;
772
773err:
774 debugfs_remove(dbgdir);
775
776 return -ENOMEM;
777}
778__initcall(debug_objects_init_debugfs);
779
780#else
781static inline void debug_objects_init_debugfs(void) { }
782#endif
783
784#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
785
786/* Random data structure for the self test */
787struct self_test {
788 unsigned long dummy1[6];
789 int static_init;
790 unsigned long dummy2[3];
791};
792
793static __initdata struct debug_obj_descr descr_type_test;
794
795/*
796 * fixup_init is called when:
797 * - an active object is initialized
798 */
799static int __init fixup_init(void *addr, enum debug_obj_state state)
800{
801 struct self_test *obj = addr;
802
803 switch (state) {
804 case ODEBUG_STATE_ACTIVE:
805 debug_object_deactivate(obj, &descr_type_test);
806 debug_object_init(obj, &descr_type_test);
807 return 1;
808 default:
809 return 0;
810 }
811}
812
813/*
814 * fixup_activate is called when:
815 * - an active object is activated
816 * - an unknown object is activated (might be a statically initialized object)
817 */
818static int __init fixup_activate(void *addr, enum debug_obj_state state)
819{
820 struct self_test *obj = addr;
821
822 switch (state) {
823 case ODEBUG_STATE_NOTAVAILABLE:
824 if (obj->static_init == 1) {
825 debug_object_init(obj, &descr_type_test);
826 debug_object_activate(obj, &descr_type_test);
827 return 0;
828 }
829 return 1;
830
831 case ODEBUG_STATE_ACTIVE:
832 debug_object_deactivate(obj, &descr_type_test);
833 debug_object_activate(obj, &descr_type_test);
834 return 1;
835
836 default:
837 return 0;
838 }
839}
840
841/*
842 * fixup_destroy is called when:
843 * - an active object is destroyed
844 */
845static int __init fixup_destroy(void *addr, enum debug_obj_state state)
846{
847 struct self_test *obj = addr;
848
849 switch (state) {
850 case ODEBUG_STATE_ACTIVE:
851 debug_object_deactivate(obj, &descr_type_test);
852 debug_object_destroy(obj, &descr_type_test);
853 return 1;
854 default:
855 return 0;
856 }
857}
858
859/*
860 * fixup_free is called when:
861 * - an active object is freed
862 */
863static int __init fixup_free(void *addr, enum debug_obj_state state)
864{
865 struct self_test *obj = addr;
866
867 switch (state) {
868 case ODEBUG_STATE_ACTIVE:
869 debug_object_deactivate(obj, &descr_type_test);
870 debug_object_free(obj, &descr_type_test);
871 return 1;
872 default:
873 return 0;
874 }
875}
876
877static int __init
878check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
879{
880 struct debug_bucket *db;
881 struct debug_obj *obj;
882 unsigned long flags;
883 int res = -EINVAL;
884
885 db = get_bucket((unsigned long) addr);
886
887 raw_spin_lock_irqsave(&db->lock, flags);
888
889 obj = lookup_object(addr, db);
890 if (!obj && state != ODEBUG_STATE_NONE) {
891 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
892 goto out;
893 }
894 if (obj && obj->state != state) {
895 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
896 obj->state, state);
897 goto out;
898 }
899 if (fixups != debug_objects_fixups) {
900 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
901 fixups, debug_objects_fixups);
902 goto out;
903 }
904 if (warnings != debug_objects_warnings) {
905 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
906 warnings, debug_objects_warnings);
907 goto out;
908 }
909 res = 0;
910out:
911 raw_spin_unlock_irqrestore(&db->lock, flags);
912 if (res)
913 debug_objects_enabled = 0;
914 return res;
915}
916
917static __initdata struct debug_obj_descr descr_type_test = {
918 .name = "selftest",
919 .fixup_init = fixup_init,
920 .fixup_activate = fixup_activate,
921 .fixup_destroy = fixup_destroy,
922 .fixup_free = fixup_free,
923};
924
925static __initdata struct self_test obj = { .static_init = 0 };
926
927static void __init debug_objects_selftest(void)
928{
929 int fixups, oldfixups, warnings, oldwarnings;
930 unsigned long flags;
931
932 local_irq_save(flags);
933
934 fixups = oldfixups = debug_objects_fixups;
935 warnings = oldwarnings = debug_objects_warnings;
936 descr_test = &descr_type_test;
937
938 debug_object_init(&obj, &descr_type_test);
939 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
940 goto out;
941 debug_object_activate(&obj, &descr_type_test);
942 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
943 goto out;
944 debug_object_activate(&obj, &descr_type_test);
945 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
946 goto out;
947 debug_object_deactivate(&obj, &descr_type_test);
948 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
949 goto out;
950 debug_object_destroy(&obj, &descr_type_test);
951 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
952 goto out;
953 debug_object_init(&obj, &descr_type_test);
954 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
955 goto out;
956 debug_object_activate(&obj, &descr_type_test);
957 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
958 goto out;
959 debug_object_deactivate(&obj, &descr_type_test);
960 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
961 goto out;
962 debug_object_free(&obj, &descr_type_test);
963 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
964 goto out;
965
966 obj.static_init = 1;
967 debug_object_activate(&obj, &descr_type_test);
968 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
969 goto out;
970 debug_object_init(&obj, &descr_type_test);
971 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
972 goto out;
973 debug_object_free(&obj, &descr_type_test);
974 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
975 goto out;
976
977#ifdef CONFIG_DEBUG_OBJECTS_FREE
978 debug_object_init(&obj, &descr_type_test);
979 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
980 goto out;
981 debug_object_activate(&obj, &descr_type_test);
982 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
983 goto out;
984 __debug_check_no_obj_freed(&obj, sizeof(obj));
985 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
986 goto out;
987#endif
988 printk(KERN_INFO "ODEBUG: selftest passed\n");
989
990out:
991 debug_objects_fixups = oldfixups;
992 debug_objects_warnings = oldwarnings;
993 descr_test = NULL;
994
995 local_irq_restore(flags);
996}
997#else
998static inline void debug_objects_selftest(void) { }
999#endif
1000
1001/*
1002 * Called during early boot to initialize the hash buckets and link
1003 * the static object pool objects into the poll list. After this call
1004 * the object tracker is fully operational.
1005 */
1006void __init debug_objects_early_init(void)
1007{
1008 int i;
1009
1010 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1011 raw_spin_lock_init(&obj_hash[i].lock);
1012
1013 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1014 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1015}
1016
1017/*
1018 * Convert the statically allocated objects to dynamic ones:
1019 */
1020static int __init debug_objects_replace_static_objects(void)
1021{
1022 struct debug_bucket *db = obj_hash;
1023 struct hlist_node *tmp;
1024 struct debug_obj *obj, *new;
1025 HLIST_HEAD(objects);
1026 int i, cnt = 0;
1027
1028 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1029 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1030 if (!obj)
1031 goto free;
1032 hlist_add_head(&obj->node, &objects);
1033 }
1034
1035 /*
1036 * When debug_objects_mem_init() is called we know that only
1037 * one CPU is up, so disabling interrupts is enough
1038 * protection. This avoids the lockdep hell of lock ordering.
1039 */
1040 local_irq_disable();
1041
1042 /* Remove the statically allocated objects from the pool */
1043 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1044 hlist_del(&obj->node);
1045 /* Move the allocated objects to the pool */
1046 hlist_move_list(&objects, &obj_pool);
1047
1048 /* Replace the active object references */
1049 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1050 hlist_move_list(&db->list, &objects);
1051
1052 hlist_for_each_entry(obj, &objects, node) {
1053 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1054 hlist_del(&new->node);
1055 /* copy object data */
1056 *new = *obj;
1057 hlist_add_head(&new->node, &db->list);
1058 cnt++;
1059 }
1060 }
1061 local_irq_enable();
1062
1063 printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt,
1064 obj_pool_used);
1065 return 0;
1066free:
1067 hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1068 hlist_del(&obj->node);
1069 kmem_cache_free(obj_cache, obj);
1070 }
1071 return -ENOMEM;
1072}
1073
1074/*
1075 * Called after the kmem_caches are functional to setup a dedicated
1076 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1077 * prevents that the debug code is called on kmem_cache_free() for the
1078 * debug tracker objects to avoid recursive calls.
1079 */
1080void __init debug_objects_mem_init(void)
1081{
1082 if (!debug_objects_enabled)
1083 return;
1084
1085 obj_cache = kmem_cache_create("debug_objects_cache",
1086 sizeof (struct debug_obj), 0,
1087 SLAB_DEBUG_OBJECTS, NULL);
1088
1089 if (!obj_cache || debug_objects_replace_static_objects()) {
1090 debug_objects_enabled = 0;
1091 if (obj_cache)
1092 kmem_cache_destroy(obj_cache);
1093 printk(KERN_WARNING "ODEBUG: out of memory.\n");
1094 } else
1095 debug_objects_selftest();
1096}