projects/linux·blob v2.6.39-rc4 · refs

1052 lines · 25.3 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#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 int 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 obj_pool_free;
90
91 if (unlikely(!obj_cache))
92 return obj_pool_free;
93
94 while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
95
96 new = kmem_cache_zalloc(obj_cache, gfp);
97 if (!new)
98 return obj_pool_free;
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 return obj_pool_free;
106}
107
108/*
109 * Lookup an object in the hash bucket.
110 */
111static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
112{
113 struct hlist_node *node;
114 struct debug_obj *obj;
115 int cnt = 0;
116
117 hlist_for_each_entry(obj, node, &b->list, node) {
118 cnt++;
119 if (obj->object == addr)
120 return obj;
121 }
122 if (cnt > debug_objects_maxchain)
123 debug_objects_maxchain = cnt;
124
125 return NULL;
126}
127
128/*
129 * Allocate a new object. If the pool is empty, switch off the debugger.
130 * Must be called with interrupts disabled.
131 */
132static struct debug_obj *
133alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
134{
135 struct debug_obj *obj = NULL;
136
137 raw_spin_lock(&pool_lock);
138 if (obj_pool.first) {
139 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
140
141 obj->object = addr;
142 obj->descr = descr;
143 obj->state = ODEBUG_STATE_NONE;
144 obj->astate = 0;
145 hlist_del(&obj->node);
146
147 hlist_add_head(&obj->node, &b->list);
148
149 obj_pool_used++;
150 if (obj_pool_used > obj_pool_max_used)
151 obj_pool_max_used = obj_pool_used;
152
153 obj_pool_free--;
154 if (obj_pool_free < obj_pool_min_free)
155 obj_pool_min_free = obj_pool_free;
156 }
157 raw_spin_unlock(&pool_lock);
158
159 return obj;
160}
161
162/*
163 * workqueue function to free objects.
164 */
165static void free_obj_work(struct work_struct *work)
166{
167 struct debug_obj *obj;
168 unsigned long flags;
169
170 raw_spin_lock_irqsave(&pool_lock, flags);
171 while (obj_pool_free > ODEBUG_POOL_SIZE) {
172 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
173 hlist_del(&obj->node);
174 obj_pool_free--;
175 /*
176 * We release pool_lock across kmem_cache_free() to
177 * avoid contention on pool_lock.
178 */
179 raw_spin_unlock_irqrestore(&pool_lock, flags);
180 kmem_cache_free(obj_cache, obj);
181 raw_spin_lock_irqsave(&pool_lock, flags);
182 }
183 raw_spin_unlock_irqrestore(&pool_lock, flags);
184}
185
186/*
187 * Put the object back into the pool and schedule work to free objects
188 * if necessary.
189 */
190static void free_object(struct debug_obj *obj)
191{
192 unsigned long flags;
193 int sched = 0;
194
195 raw_spin_lock_irqsave(&pool_lock, flags);
196 /*
197 * schedule work when the pool is filled and the cache is
198 * initialized:
199 */
200 if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache)
201 sched = !work_pending(&debug_obj_work);
202 hlist_add_head(&obj->node, &obj_pool);
203 obj_pool_free++;
204 obj_pool_used--;
205 raw_spin_unlock_irqrestore(&pool_lock, flags);
206 if (sched)
207 schedule_work(&debug_obj_work);
208}
209
210/*
211 * We run out of memory. That means we probably have tons of objects
212 * allocated.
213 */
214static void debug_objects_oom(void)
215{
216 struct debug_bucket *db = obj_hash;
217 struct hlist_node *node, *tmp;
218 HLIST_HEAD(freelist);
219 struct debug_obj *obj;
220 unsigned long flags;
221 int i;
222
223 printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
224
225 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
226 raw_spin_lock_irqsave(&db->lock, flags);
227 hlist_move_list(&db->list, &freelist);
228 raw_spin_unlock_irqrestore(&db->lock, flags);
229
230 /* Now free them */
231 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
232 hlist_del(&obj->node);
233 free_object(obj);
234 }
235 }
236}
237
238/*
239 * We use the pfn of the address for the hash. That way we can check
240 * for freed objects simply by checking the affected bucket.
241 */
242static struct debug_bucket *get_bucket(unsigned long addr)
243{
244 unsigned long hash;
245
246 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
247 return &obj_hash[hash];
248}
249
250static void debug_print_object(struct debug_obj *obj, char *msg)
251{
252 struct debug_obj_descr *descr = obj->descr;
253 static int limit;
254
255 if (limit < 5 && descr != descr_test) {
256 void *hint = descr->debug_hint ?
257 descr->debug_hint(obj->object) : NULL;
258 limit++;
259 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
260 "object type: %s hint: %pS\n",
261 msg, obj_states[obj->state], obj->astate,
262 descr->name, hint);
263 }
264 debug_objects_warnings++;
265}
266
267/*
268 * Try to repair the damage, so we have a better chance to get useful
269 * debug output.
270 */
271static void
272debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
273 void * addr, enum debug_obj_state state)
274{
275 if (fixup)
276 debug_objects_fixups += fixup(addr, state);
277}
278
279static void debug_object_is_on_stack(void *addr, int onstack)
280{
281 int is_on_stack;
282 static int limit;
283
284 if (limit > 4)
285 return;
286
287 is_on_stack = object_is_on_stack(addr);
288 if (is_on_stack == onstack)
289 return;
290
291 limit++;
292 if (is_on_stack)
293 printk(KERN_WARNING
294 "ODEBUG: object is on stack, but not annotated\n");
295 else
296 printk(KERN_WARNING
297 "ODEBUG: object is not on stack, but annotated\n");
298 WARN_ON(1);
299}
300
301static void
302__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
303{
304 enum debug_obj_state state;
305 struct debug_bucket *db;
306 struct debug_obj *obj;
307 unsigned long flags;
308
309 fill_pool();
310
311 db = get_bucket((unsigned long) addr);
312
313 raw_spin_lock_irqsave(&db->lock, flags);
314
315 obj = lookup_object(addr, db);
316 if (!obj) {
317 obj = alloc_object(addr, db, descr);
318 if (!obj) {
319 debug_objects_enabled = 0;
320 raw_spin_unlock_irqrestore(&db->lock, flags);
321 debug_objects_oom();
322 return;
323 }
324 debug_object_is_on_stack(addr, onstack);
325 }
326
327 switch (obj->state) {
328 case ODEBUG_STATE_NONE:
329 case ODEBUG_STATE_INIT:
330 case ODEBUG_STATE_INACTIVE:
331 obj->state = ODEBUG_STATE_INIT;
332 break;
333
334 case ODEBUG_STATE_ACTIVE:
335 debug_print_object(obj, "init");
336 state = obj->state;
337 raw_spin_unlock_irqrestore(&db->lock, flags);
338 debug_object_fixup(descr->fixup_init, addr, state);
339 return;
340
341 case ODEBUG_STATE_DESTROYED:
342 debug_print_object(obj, "init");
343 break;
344 default:
345 break;
346 }
347
348 raw_spin_unlock_irqrestore(&db->lock, flags);
349}
350
351/**
352 * debug_object_init - debug checks when an object is initialized
353 * @addr: address of the object
354 * @descr: pointer to an object specific debug description structure
355 */
356void debug_object_init(void *addr, struct debug_obj_descr *descr)
357{
358 if (!debug_objects_enabled)
359 return;
360
361 __debug_object_init(addr, descr, 0);
362}
363
364/**
365 * debug_object_init_on_stack - debug checks when an object on stack is
366 * initialized
367 * @addr: address of the object
368 * @descr: pointer to an object specific debug description structure
369 */
370void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
371{
372 if (!debug_objects_enabled)
373 return;
374
375 __debug_object_init(addr, descr, 1);
376}
377
378/**
379 * debug_object_activate - debug checks when an object is activated
380 * @addr: address of the object
381 * @descr: pointer to an object specific debug description structure
382 */
383void debug_object_activate(void *addr, struct debug_obj_descr *descr)
384{
385 enum debug_obj_state state;
386 struct debug_bucket *db;
387 struct debug_obj *obj;
388 unsigned long flags;
389
390 if (!debug_objects_enabled)
391 return;
392
393 db = get_bucket((unsigned long) addr);
394
395 raw_spin_lock_irqsave(&db->lock, flags);
396
397 obj = lookup_object(addr, db);
398 if (obj) {
399 switch (obj->state) {
400 case ODEBUG_STATE_INIT:
401 case ODEBUG_STATE_INACTIVE:
402 obj->state = ODEBUG_STATE_ACTIVE;
403 break;
404
405 case ODEBUG_STATE_ACTIVE:
406 debug_print_object(obj, "activate");
407 state = obj->state;
408 raw_spin_unlock_irqrestore(&db->lock, flags);
409 debug_object_fixup(descr->fixup_activate, addr, state);
410 return;
411
412 case ODEBUG_STATE_DESTROYED:
413 debug_print_object(obj, "activate");
414 break;
415 default:
416 break;
417 }
418 raw_spin_unlock_irqrestore(&db->lock, flags);
419 return;
420 }
421
422 raw_spin_unlock_irqrestore(&db->lock, flags);
423 /*
424 * This happens when a static object is activated. We
425 * let the type specific code decide whether this is
426 * true or not.
427 */
428 debug_object_fixup(descr->fixup_activate, addr,
429 ODEBUG_STATE_NOTAVAILABLE);
430}
431
432/**
433 * debug_object_deactivate - debug checks when an object is deactivated
434 * @addr: address of the object
435 * @descr: pointer to an object specific debug description structure
436 */
437void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
438{
439 struct debug_bucket *db;
440 struct debug_obj *obj;
441 unsigned long flags;
442
443 if (!debug_objects_enabled)
444 return;
445
446 db = get_bucket((unsigned long) addr);
447
448 raw_spin_lock_irqsave(&db->lock, flags);
449
450 obj = lookup_object(addr, db);
451 if (obj) {
452 switch (obj->state) {
453 case ODEBUG_STATE_INIT:
454 case ODEBUG_STATE_INACTIVE:
455 case ODEBUG_STATE_ACTIVE:
456 if (!obj->astate)
457 obj->state = ODEBUG_STATE_INACTIVE;
458 else
459 debug_print_object(obj, "deactivate");
460 break;
461
462 case ODEBUG_STATE_DESTROYED:
463 debug_print_object(obj, "deactivate");
464 break;
465 default:
466 break;
467 }
468 } else {
469 struct debug_obj o = { .object = addr,
470 .state = ODEBUG_STATE_NOTAVAILABLE,
471 .descr = descr };
472
473 debug_print_object(&o, "deactivate");
474 }
475
476 raw_spin_unlock_irqrestore(&db->lock, flags);
477}
478
479/**
480 * debug_object_destroy - debug checks when an object is destroyed
481 * @addr: address of the object
482 * @descr: pointer to an object specific debug description structure
483 */
484void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
485{
486 enum debug_obj_state state;
487 struct debug_bucket *db;
488 struct debug_obj *obj;
489 unsigned long flags;
490
491 if (!debug_objects_enabled)
492 return;
493
494 db = get_bucket((unsigned long) addr);
495
496 raw_spin_lock_irqsave(&db->lock, flags);
497
498 obj = lookup_object(addr, db);
499 if (!obj)
500 goto out_unlock;
501
502 switch (obj->state) {
503 case ODEBUG_STATE_NONE:
504 case ODEBUG_STATE_INIT:
505 case ODEBUG_STATE_INACTIVE:
506 obj->state = ODEBUG_STATE_DESTROYED;
507 break;
508 case ODEBUG_STATE_ACTIVE:
509 debug_print_object(obj, "destroy");
510 state = obj->state;
511 raw_spin_unlock_irqrestore(&db->lock, flags);
512 debug_object_fixup(descr->fixup_destroy, addr, state);
513 return;
514
515 case ODEBUG_STATE_DESTROYED:
516 debug_print_object(obj, "destroy");
517 break;
518 default:
519 break;
520 }
521out_unlock:
522 raw_spin_unlock_irqrestore(&db->lock, flags);
523}
524
525/**
526 * debug_object_free - debug checks when an object is freed
527 * @addr: address of the object
528 * @descr: pointer to an object specific debug description structure
529 */
530void debug_object_free(void *addr, struct debug_obj_descr *descr)
531{
532 enum debug_obj_state state;
533 struct debug_bucket *db;
534 struct debug_obj *obj;
535 unsigned long flags;
536
537 if (!debug_objects_enabled)
538 return;
539
540 db = get_bucket((unsigned long) addr);
541
542 raw_spin_lock_irqsave(&db->lock, flags);
543
544 obj = lookup_object(addr, db);
545 if (!obj)
546 goto out_unlock;
547
548 switch (obj->state) {
549 case ODEBUG_STATE_ACTIVE:
550 debug_print_object(obj, "free");
551 state = obj->state;
552 raw_spin_unlock_irqrestore(&db->lock, flags);
553 debug_object_fixup(descr->fixup_free, addr, state);
554 return;
555 default:
556 hlist_del(&obj->node);
557 raw_spin_unlock_irqrestore(&db->lock, flags);
558 free_object(obj);
559 return;
560 }
561out_unlock:
562 raw_spin_unlock_irqrestore(&db->lock, flags);
563}
564
565/**
566 * debug_object_active_state - debug checks object usage state machine
567 * @addr: address of the object
568 * @descr: pointer to an object specific debug description structure
569 * @expect: expected state
570 * @next: state to move to if expected state is found
571 */
572void
573debug_object_active_state(void *addr, struct debug_obj_descr *descr,
574 unsigned int expect, unsigned int next)
575{
576 struct debug_bucket *db;
577 struct debug_obj *obj;
578 unsigned long flags;
579
580 if (!debug_objects_enabled)
581 return;
582
583 db = get_bucket((unsigned long) addr);
584
585 raw_spin_lock_irqsave(&db->lock, flags);
586
587 obj = lookup_object(addr, db);
588 if (obj) {
589 switch (obj->state) {
590 case ODEBUG_STATE_ACTIVE:
591 if (obj->astate == expect)
592 obj->astate = next;
593 else
594 debug_print_object(obj, "active_state");
595 break;
596
597 default:
598 debug_print_object(obj, "active_state");
599 break;
600 }
601 } else {
602 struct debug_obj o = { .object = addr,
603 .state = ODEBUG_STATE_NOTAVAILABLE,
604 .descr = descr };
605
606 debug_print_object(&o, "active_state");
607 }
608
609 raw_spin_unlock_irqrestore(&db->lock, flags);
610}
611
612#ifdef CONFIG_DEBUG_OBJECTS_FREE
613static void __debug_check_no_obj_freed(const void *address, unsigned long size)
614{
615 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
616 struct hlist_node *node, *tmp;
617 HLIST_HEAD(freelist);
618 struct debug_obj_descr *descr;
619 enum debug_obj_state state;
620 struct debug_bucket *db;
621 struct debug_obj *obj;
622 int cnt;
623
624 saddr = (unsigned long) address;
625 eaddr = saddr + size;
626 paddr = saddr & ODEBUG_CHUNK_MASK;
627 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
628 chunks >>= ODEBUG_CHUNK_SHIFT;
629
630 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
631 db = get_bucket(paddr);
632
633repeat:
634 cnt = 0;
635 raw_spin_lock_irqsave(&db->lock, flags);
636 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
637 cnt++;
638 oaddr = (unsigned long) obj->object;
639 if (oaddr < saddr || oaddr >= eaddr)
640 continue;
641
642 switch (obj->state) {
643 case ODEBUG_STATE_ACTIVE:
644 debug_print_object(obj, "free");
645 descr = obj->descr;
646 state = obj->state;
647 raw_spin_unlock_irqrestore(&db->lock, flags);
648 debug_object_fixup(descr->fixup_free,
649 (void *) oaddr, state);
650 goto repeat;
651 default:
652 hlist_del(&obj->node);
653 hlist_add_head(&obj->node, &freelist);
654 break;
655 }
656 }
657 raw_spin_unlock_irqrestore(&db->lock, flags);
658
659 /* Now free them */
660 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
661 hlist_del(&obj->node);
662 free_object(obj);
663 }
664
665 if (cnt > debug_objects_maxchain)
666 debug_objects_maxchain = cnt;
667 }
668}
669
670void debug_check_no_obj_freed(const void *address, unsigned long size)
671{
672 if (debug_objects_enabled)
673 __debug_check_no_obj_freed(address, size);
674}
675#endif
676
677#ifdef CONFIG_DEBUG_FS
678
679static int debug_stats_show(struct seq_file *m, void *v)
680{
681 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
682 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
683 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
684 seq_printf(m, "pool_free :%d\n", obj_pool_free);
685 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
686 seq_printf(m, "pool_used :%d\n", obj_pool_used);
687 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
688 return 0;
689}
690
691static int debug_stats_open(struct inode *inode, struct file *filp)
692{
693 return single_open(filp, debug_stats_show, NULL);
694}
695
696static const struct file_operations debug_stats_fops = {
697 .open = debug_stats_open,
698 .read = seq_read,
699 .llseek = seq_lseek,
700 .release = single_release,
701};
702
703static int __init debug_objects_init_debugfs(void)
704{
705 struct dentry *dbgdir, *dbgstats;
706
707 if (!debug_objects_enabled)
708 return 0;
709
710 dbgdir = debugfs_create_dir("debug_objects", NULL);
711 if (!dbgdir)
712 return -ENOMEM;
713
714 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
715 &debug_stats_fops);
716 if (!dbgstats)
717 goto err;
718
719 return 0;
720
721err:
722 debugfs_remove(dbgdir);
723
724 return -ENOMEM;
725}
726__initcall(debug_objects_init_debugfs);
727
728#else
729static inline void debug_objects_init_debugfs(void) { }
730#endif
731
732#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
733
734/* Random data structure for the self test */
735struct self_test {
736 unsigned long dummy1[6];
737 int static_init;
738 unsigned long dummy2[3];
739};
740
741static __initdata struct debug_obj_descr descr_type_test;
742
743/*
744 * fixup_init is called when:
745 * - an active object is initialized
746 */
747static int __init fixup_init(void *addr, enum debug_obj_state state)
748{
749 struct self_test *obj = addr;
750
751 switch (state) {
752 case ODEBUG_STATE_ACTIVE:
753 debug_object_deactivate(obj, &descr_type_test);
754 debug_object_init(obj, &descr_type_test);
755 return 1;
756 default:
757 return 0;
758 }
759}
760
761/*
762 * fixup_activate is called when:
763 * - an active object is activated
764 * - an unknown object is activated (might be a statically initialized object)
765 */
766static int __init fixup_activate(void *addr, enum debug_obj_state state)
767{
768 struct self_test *obj = addr;
769
770 switch (state) {
771 case ODEBUG_STATE_NOTAVAILABLE:
772 if (obj->static_init == 1) {
773 debug_object_init(obj, &descr_type_test);
774 debug_object_activate(obj, &descr_type_test);
775 /*
776 * Real code should return 0 here ! This is
777 * not a fixup of some bad behaviour. We
778 * merily call the debug_init function to keep
779 * track of the object.
780 */
781 return 1;
782 } else {
783 /* Real code needs to emit a warning here */
784 }
785 return 0;
786
787 case ODEBUG_STATE_ACTIVE:
788 debug_object_deactivate(obj, &descr_type_test);
789 debug_object_activate(obj, &descr_type_test);
790 return 1;
791
792 default:
793 return 0;
794 }
795}
796
797/*
798 * fixup_destroy is called when:
799 * - an active object is destroyed
800 */
801static int __init fixup_destroy(void *addr, enum debug_obj_state state)
802{
803 struct self_test *obj = addr;
804
805 switch (state) {
806 case ODEBUG_STATE_ACTIVE:
807 debug_object_deactivate(obj, &descr_type_test);
808 debug_object_destroy(obj, &descr_type_test);
809 return 1;
810 default:
811 return 0;
812 }
813}
814
815/*
816 * fixup_free is called when:
817 * - an active object is freed
818 */
819static int __init fixup_free(void *addr, enum debug_obj_state state)
820{
821 struct self_test *obj = addr;
822
823 switch (state) {
824 case ODEBUG_STATE_ACTIVE:
825 debug_object_deactivate(obj, &descr_type_test);
826 debug_object_free(obj, &descr_type_test);
827 return 1;
828 default:
829 return 0;
830 }
831}
832
833static int __init
834check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
835{
836 struct debug_bucket *db;
837 struct debug_obj *obj;
838 unsigned long flags;
839 int res = -EINVAL;
840
841 db = get_bucket((unsigned long) addr);
842
843 raw_spin_lock_irqsave(&db->lock, flags);
844
845 obj = lookup_object(addr, db);
846 if (!obj && state != ODEBUG_STATE_NONE) {
847 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
848 goto out;
849 }
850 if (obj && obj->state != state) {
851 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
852 obj->state, state);
853 goto out;
854 }
855 if (fixups != debug_objects_fixups) {
856 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
857 fixups, debug_objects_fixups);
858 goto out;
859 }
860 if (warnings != debug_objects_warnings) {
861 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
862 warnings, debug_objects_warnings);
863 goto out;
864 }
865 res = 0;
866out:
867 raw_spin_unlock_irqrestore(&db->lock, flags);
868 if (res)
869 debug_objects_enabled = 0;
870 return res;
871}
872
873static __initdata struct debug_obj_descr descr_type_test = {
874 .name = "selftest",
875 .fixup_init = fixup_init,
876 .fixup_activate = fixup_activate,
877 .fixup_destroy = fixup_destroy,
878 .fixup_free = fixup_free,
879};
880
881static __initdata struct self_test obj = { .static_init = 0 };
882
883static void __init debug_objects_selftest(void)
884{
885 int fixups, oldfixups, warnings, oldwarnings;
886 unsigned long flags;
887
888 local_irq_save(flags);
889
890 fixups = oldfixups = debug_objects_fixups;
891 warnings = oldwarnings = debug_objects_warnings;
892 descr_test = &descr_type_test;
893
894 debug_object_init(&obj, &descr_type_test);
895 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
896 goto out;
897 debug_object_activate(&obj, &descr_type_test);
898 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
899 goto out;
900 debug_object_activate(&obj, &descr_type_test);
901 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
902 goto out;
903 debug_object_deactivate(&obj, &descr_type_test);
904 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
905 goto out;
906 debug_object_destroy(&obj, &descr_type_test);
907 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
908 goto out;
909 debug_object_init(&obj, &descr_type_test);
910 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
911 goto out;
912 debug_object_activate(&obj, &descr_type_test);
913 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
914 goto out;
915 debug_object_deactivate(&obj, &descr_type_test);
916 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
917 goto out;
918 debug_object_free(&obj, &descr_type_test);
919 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
920 goto out;
921
922 obj.static_init = 1;
923 debug_object_activate(&obj, &descr_type_test);
924 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
925 goto out;
926 debug_object_init(&obj, &descr_type_test);
927 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
928 goto out;
929 debug_object_free(&obj, &descr_type_test);
930 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
931 goto out;
932
933#ifdef CONFIG_DEBUG_OBJECTS_FREE
934 debug_object_init(&obj, &descr_type_test);
935 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
936 goto out;
937 debug_object_activate(&obj, &descr_type_test);
938 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
939 goto out;
940 __debug_check_no_obj_freed(&obj, sizeof(obj));
941 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
942 goto out;
943#endif
944 printk(KERN_INFO "ODEBUG: selftest passed\n");
945
946out:
947 debug_objects_fixups = oldfixups;
948 debug_objects_warnings = oldwarnings;
949 descr_test = NULL;
950
951 local_irq_restore(flags);
952}
953#else
954static inline void debug_objects_selftest(void) { }
955#endif
956
957/*
958 * Called during early boot to initialize the hash buckets and link
959 * the static object pool objects into the poll list. After this call
960 * the object tracker is fully operational.
961 */
962void __init debug_objects_early_init(void)
963{
964 int i;
965
966 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
967 raw_spin_lock_init(&obj_hash[i].lock);
968
969 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
970 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
971}
972
973/*
974 * Convert the statically allocated objects to dynamic ones:
975 */
976static int __init debug_objects_replace_static_objects(void)
977{
978 struct debug_bucket *db = obj_hash;
979 struct hlist_node *node, *tmp;
980 struct debug_obj *obj, *new;
981 HLIST_HEAD(objects);
982 int i, cnt = 0;
983
984 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
985 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
986 if (!obj)
987 goto free;
988 hlist_add_head(&obj->node, &objects);
989 }
990
991 /*
992 * When debug_objects_mem_init() is called we know that only
993 * one CPU is up, so disabling interrupts is enough
994 * protection. This avoids the lockdep hell of lock ordering.
995 */
996 local_irq_disable();
997
998 /* Remove the statically allocated objects from the pool */
999 hlist_for_each_entry_safe(obj, node, tmp, &obj_pool, node)
1000 hlist_del(&obj->node);
1001 /* Move the allocated objects to the pool */
1002 hlist_move_list(&objects, &obj_pool);
1003
1004 /* Replace the active object references */
1005 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1006 hlist_move_list(&db->list, &objects);
1007
1008 hlist_for_each_entry(obj, node, &objects, node) {
1009 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1010 hlist_del(&new->node);
1011 /* copy object data */
1012 *new = *obj;
1013 hlist_add_head(&new->node, &db->list);
1014 cnt++;
1015 }
1016 }
1017
1018 printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt,
1019 obj_pool_used);
1020 local_irq_enable();
1021 return 0;
1022free:
1023 hlist_for_each_entry_safe(obj, node, tmp, &objects, node) {
1024 hlist_del(&obj->node);
1025 kmem_cache_free(obj_cache, obj);
1026 }
1027 return -ENOMEM;
1028}
1029
1030/*
1031 * Called after the kmem_caches are functional to setup a dedicated
1032 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1033 * prevents that the debug code is called on kmem_cache_free() for the
1034 * debug tracker objects to avoid recursive calls.
1035 */
1036void __init debug_objects_mem_init(void)
1037{
1038 if (!debug_objects_enabled)
1039 return;
1040
1041 obj_cache = kmem_cache_create("debug_objects_cache",
1042 sizeof (struct debug_obj), 0,
1043 SLAB_DEBUG_OBJECTS, NULL);
1044
1045 if (!obj_cache || debug_objects_replace_static_objects()) {
1046 debug_objects_enabled = 0;
1047 if (obj_cache)
1048 kmem_cache_destroy(obj_cache);
1049 printk(KERN_WARNING "ODEBUG: out of memory.\n");
1050 } else
1051 debug_objects_selftest();
1052}