projects/linux·blob v3.8 · refs

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