45a6bde762d12232fab2c1f422e398625bb35e37
[linux-2.6.git] / lib / debugobjects.c
1 /*
2  * Generic infrastructure for lifetime debugging of objects.
3  *
4  * Started by Thomas Gleixner
5  *
6  * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de>
7  *
8  * For licencing details see kernel-base/COPYING
9  */
10 #include <linux/debugobjects.h>
11 #include <linux/interrupt.h>
12 #include <linux/seq_file.h>
13 #include <linux/debugfs.h>
14 #include <linux/hash.h>
15
16 #define ODEBUG_HASH_BITS        14
17 #define ODEBUG_HASH_SIZE        (1 << ODEBUG_HASH_BITS)
18
19 #define ODEBUG_POOL_SIZE        512
20 #define ODEBUG_POOL_MIN_LEVEL   256
21
22 #define ODEBUG_CHUNK_SHIFT      PAGE_SHIFT
23 #define ODEBUG_CHUNK_SIZE       (1 << ODEBUG_CHUNK_SHIFT)
24 #define ODEBUG_CHUNK_MASK       (~(ODEBUG_CHUNK_SIZE - 1))
25
26 struct debug_bucket {
27         struct hlist_head       list;
28         spinlock_t              lock;
29 };
30
31 static struct debug_bucket      obj_hash[ODEBUG_HASH_SIZE];
32
33 static struct debug_obj         obj_static_pool[ODEBUG_POOL_SIZE];
34
35 static DEFINE_SPINLOCK(pool_lock);
36
37 static HLIST_HEAD(obj_pool);
38
39 static int                      obj_pool_min_free = ODEBUG_POOL_SIZE;
40 static int                      obj_pool_free = ODEBUG_POOL_SIZE;
41 static int                      obj_pool_used;
42 static int                      obj_pool_max_used;
43 static struct kmem_cache        *obj_cache;
44
45 static int                      debug_objects_maxchain __read_mostly;
46 static int                      debug_objects_fixups __read_mostly;
47 static int                      debug_objects_warnings __read_mostly;
48 static int                      debug_objects_enabled __read_mostly;
49 static struct debug_obj_descr   *descr_test  __read_mostly;
50
51 static int __init enable_object_debug(char *str)
52 {
53         debug_objects_enabled = 1;
54         return 0;
55 }
56 early_param("debug_objects", enable_object_debug);
57
58 static const char *obj_states[ODEBUG_STATE_MAX] = {
59         [ODEBUG_STATE_NONE]             = "none",
60         [ODEBUG_STATE_INIT]             = "initialized",
61         [ODEBUG_STATE_INACTIVE]         = "inactive",
62         [ODEBUG_STATE_ACTIVE]           = "active",
63         [ODEBUG_STATE_DESTROYED]        = "destroyed",
64         [ODEBUG_STATE_NOTAVAILABLE]     = "not available",
65 };
66
67 static int fill_pool(void)
68 {
69         gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
70         struct debug_obj *new;
71         unsigned long flags;
72
73         if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
74                 return obj_pool_free;
75
76         if (unlikely(!obj_cache))
77                 return obj_pool_free;
78
79         while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
80
81                 new = kmem_cache_zalloc(obj_cache, gfp);
82                 if (!new)
83                         return obj_pool_free;
84
85                 spin_lock_irqsave(&pool_lock, flags);
86                 hlist_add_head(&new->node, &obj_pool);
87                 obj_pool_free++;
88                 spin_unlock_irqrestore(&pool_lock, flags);
89         }
90         return obj_pool_free;
91 }
92
93 /*
94  * Lookup an object in the hash bucket.
95  */
96 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
97 {
98         struct hlist_node *node;
99         struct debug_obj *obj;
100         int cnt = 0;
101
102         hlist_for_each_entry(obj, node, &b->list, node) {
103                 cnt++;
104                 if (obj->object == addr)
105                         return obj;
106         }
107         if (cnt > debug_objects_maxchain)
108                 debug_objects_maxchain = cnt;
109
110         return NULL;
111 }
112
113 /*
114  * Allocate a new object. If the pool is empty, switch off the debugger.
115  */
116 static struct debug_obj *
117 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
118 {
119         struct debug_obj *obj = NULL;
120
121         spin_lock(&pool_lock);
122         if (obj_pool.first) {
123                 obj         = hlist_entry(obj_pool.first, typeof(*obj), node);
124
125                 obj->object = addr;
126                 obj->descr  = descr;
127                 obj->state  = ODEBUG_STATE_NONE;
128                 hlist_del(&obj->node);
129
130                 hlist_add_head(&obj->node, &b->list);
131
132                 obj_pool_used++;
133                 if (obj_pool_used > obj_pool_max_used)
134                         obj_pool_max_used = obj_pool_used;
135
136                 obj_pool_free--;
137                 if (obj_pool_free < obj_pool_min_free)
138                         obj_pool_min_free = obj_pool_free;
139         }
140         spin_unlock(&pool_lock);
141
142         return obj;
143 }
144
145 /*
146  * Put the object back into the pool or give it back to kmem_cache:
147  */
148 static void free_object(struct debug_obj *obj)
149 {
150         unsigned long idx = (unsigned long)(obj - obj_static_pool);
151
152         if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
153                 spin_lock(&pool_lock);
154                 hlist_add_head(&obj->node, &obj_pool);
155                 obj_pool_free++;
156                 obj_pool_used--;
157                 spin_unlock(&pool_lock);
158         } else {
159                 spin_lock(&pool_lock);
160                 obj_pool_used--;
161                 spin_unlock(&pool_lock);
162                 kmem_cache_free(obj_cache, obj);
163         }
164 }
165
166 /*
167  * We run out of memory. That means we probably have tons of objects
168  * allocated.
169  */
170 static void debug_objects_oom(void)
171 {
172         struct debug_bucket *db = obj_hash;
173         struct hlist_node *node, *tmp;
174         struct debug_obj *obj;
175         unsigned long flags;
176         int i;
177
178         printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
179
180         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
181                 spin_lock_irqsave(&db->lock, flags);
182                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
183                         hlist_del(&obj->node);
184                         free_object(obj);
185                 }
186                 spin_unlock_irqrestore(&db->lock, flags);
187         }
188 }
189
190 /*
191  * We use the pfn of the address for the hash. That way we can check
192  * for freed objects simply by checking the affected bucket.
193  */
194 static struct debug_bucket *get_bucket(unsigned long addr)
195 {
196         unsigned long hash;
197
198         hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
199         return &obj_hash[hash];
200 }
201
202 static void debug_print_object(struct debug_obj *obj, char *msg)
203 {
204         static int limit;
205
206         if (limit < 5 && obj->descr != descr_test) {
207                 limit++;
208                 WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
209                        obj_states[obj->state], obj->descr->name);
210         }
211         debug_objects_warnings++;
212 }
213
214 /*
215  * Try to repair the damage, so we have a better chance to get useful
216  * debug output.
217  */
218 static void
219 debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
220                    void * addr, enum debug_obj_state state)
221 {
222         if (fixup)
223                 debug_objects_fixups += fixup(addr, state);
224 }
225
226 static void debug_object_is_on_stack(void *addr, int onstack)
227 {
228         int is_on_stack;
229         static int limit;
230
231         if (limit > 4)
232                 return;
233
234         is_on_stack = object_is_on_stack(addr);
235         if (is_on_stack == onstack)
236                 return;
237
238         limit++;
239         if (is_on_stack)
240                 printk(KERN_WARNING
241                        "ODEBUG: object is on stack, but not annotated\n");
242         else
243                 printk(KERN_WARNING
244                        "ODEBUG: object is not on stack, but annotated\n");
245         WARN_ON(1);
246 }
247
248 static void
249 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
250 {
251         enum debug_obj_state state;
252         struct debug_bucket *db;
253         struct debug_obj *obj;
254         unsigned long flags;
255
256         fill_pool();
257
258         db = get_bucket((unsigned long) addr);
259
260         spin_lock_irqsave(&db->lock, flags);
261
262         obj = lookup_object(addr, db);
263         if (!obj) {
264                 obj = alloc_object(addr, db, descr);
265                 if (!obj) {
266                         debug_objects_enabled = 0;
267                         spin_unlock_irqrestore(&db->lock, flags);
268                         debug_objects_oom();
269                         return;
270                 }
271                 debug_object_is_on_stack(addr, onstack);
272         }
273
274         switch (obj->state) {
275         case ODEBUG_STATE_NONE:
276         case ODEBUG_STATE_INIT:
277         case ODEBUG_STATE_INACTIVE:
278                 obj->state = ODEBUG_STATE_INIT;
279                 break;
280
281         case ODEBUG_STATE_ACTIVE:
282                 debug_print_object(obj, "init");
283                 state = obj->state;
284                 spin_unlock_irqrestore(&db->lock, flags);
285                 debug_object_fixup(descr->fixup_init, addr, state);
286                 return;
287
288         case ODEBUG_STATE_DESTROYED:
289                 debug_print_object(obj, "init");
290                 break;
291         default:
292                 break;
293         }
294
295         spin_unlock_irqrestore(&db->lock, flags);
296 }
297
298 /**
299  * debug_object_init - debug checks when an object is initialized
300  * @addr:       address of the object
301  * @descr:      pointer to an object specific debug description structure
302  */
303 void debug_object_init(void *addr, struct debug_obj_descr *descr)
304 {
305         if (!debug_objects_enabled)
306                 return;
307
308         __debug_object_init(addr, descr, 0);
309 }
310
311 /**
312  * debug_object_init_on_stack - debug checks when an object on stack is
313  *                              initialized
314  * @addr:       address of the object
315  * @descr:      pointer to an object specific debug description structure
316  */
317 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
318 {
319         if (!debug_objects_enabled)
320                 return;
321
322         __debug_object_init(addr, descr, 1);
323 }
324
325 /**
326  * debug_object_activate - debug checks when an object is activated
327  * @addr:       address of the object
328  * @descr:      pointer to an object specific debug description structure
329  */
330 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
331 {
332         enum debug_obj_state state;
333         struct debug_bucket *db;
334         struct debug_obj *obj;
335         unsigned long flags;
336
337         if (!debug_objects_enabled)
338                 return;
339
340         db = get_bucket((unsigned long) addr);
341
342         spin_lock_irqsave(&db->lock, flags);
343
344         obj = lookup_object(addr, db);
345         if (obj) {
346                 switch (obj->state) {
347                 case ODEBUG_STATE_INIT:
348                 case ODEBUG_STATE_INACTIVE:
349                         obj->state = ODEBUG_STATE_ACTIVE;
350                         break;
351
352                 case ODEBUG_STATE_ACTIVE:
353                         debug_print_object(obj, "activate");
354                         state = obj->state;
355                         spin_unlock_irqrestore(&db->lock, flags);
356                         debug_object_fixup(descr->fixup_activate, addr, state);
357                         return;
358
359                 case ODEBUG_STATE_DESTROYED:
360                         debug_print_object(obj, "activate");
361                         break;
362                 default:
363                         break;
364                 }
365                 spin_unlock_irqrestore(&db->lock, flags);
366                 return;
367         }
368
369         spin_unlock_irqrestore(&db->lock, flags);
370         /*
371          * This happens when a static object is activated. We
372          * let the type specific code decide whether this is
373          * true or not.
374          */
375         debug_object_fixup(descr->fixup_activate, addr,
376                            ODEBUG_STATE_NOTAVAILABLE);
377 }
378
379 /**
380  * debug_object_deactivate - debug checks when an object is deactivated
381  * @addr:       address of the object
382  * @descr:      pointer to an object specific debug description structure
383  */
384 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
385 {
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         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                 case ODEBUG_STATE_ACTIVE:
403                         obj->state = ODEBUG_STATE_INACTIVE;
404                         break;
405
406                 case ODEBUG_STATE_DESTROYED:
407                         debug_print_object(obj, "deactivate");
408                         break;
409                 default:
410                         break;
411                 }
412         } else {
413                 struct debug_obj o = { .object = addr,
414                                        .state = ODEBUG_STATE_NOTAVAILABLE,
415                                        .descr = descr };
416
417                 debug_print_object(&o, "deactivate");
418         }
419
420         spin_unlock_irqrestore(&db->lock, flags);
421 }
422
423 /**
424  * debug_object_destroy - debug checks when an object is destroyed
425  * @addr:       address of the object
426  * @descr:      pointer to an object specific debug description structure
427  */
428 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
429 {
430         enum debug_obj_state state;
431         struct debug_bucket *db;
432         struct debug_obj *obj;
433         unsigned long flags;
434
435         if (!debug_objects_enabled)
436                 return;
437
438         db = get_bucket((unsigned long) addr);
439
440         spin_lock_irqsave(&db->lock, flags);
441
442         obj = lookup_object(addr, db);
443         if (!obj)
444                 goto out_unlock;
445
446         switch (obj->state) {
447         case ODEBUG_STATE_NONE:
448         case ODEBUG_STATE_INIT:
449         case ODEBUG_STATE_INACTIVE:
450                 obj->state = ODEBUG_STATE_DESTROYED;
451                 break;
452         case ODEBUG_STATE_ACTIVE:
453                 debug_print_object(obj, "destroy");
454                 state = obj->state;
455                 spin_unlock_irqrestore(&db->lock, flags);
456                 debug_object_fixup(descr->fixup_destroy, addr, state);
457                 return;
458
459         case ODEBUG_STATE_DESTROYED:
460                 debug_print_object(obj, "destroy");
461                 break;
462         default:
463                 break;
464         }
465 out_unlock:
466         spin_unlock_irqrestore(&db->lock, flags);
467 }
468
469 /**
470  * debug_object_free - debug checks when an object is freed
471  * @addr:       address of the object
472  * @descr:      pointer to an object specific debug description structure
473  */
474 void debug_object_free(void *addr, struct debug_obj_descr *descr)
475 {
476         enum debug_obj_state state;
477         struct debug_bucket *db;
478         struct debug_obj *obj;
479         unsigned long flags;
480
481         if (!debug_objects_enabled)
482                 return;
483
484         db = get_bucket((unsigned long) addr);
485
486         spin_lock_irqsave(&db->lock, flags);
487
488         obj = lookup_object(addr, db);
489         if (!obj)
490                 goto out_unlock;
491
492         switch (obj->state) {
493         case ODEBUG_STATE_ACTIVE:
494                 debug_print_object(obj, "free");
495                 state = obj->state;
496                 spin_unlock_irqrestore(&db->lock, flags);
497                 debug_object_fixup(descr->fixup_free, addr, state);
498                 return;
499         default:
500                 hlist_del(&obj->node);
501                 free_object(obj);
502                 break;
503         }
504 out_unlock:
505         spin_unlock_irqrestore(&db->lock, flags);
506 }
507
508 #ifdef CONFIG_DEBUG_OBJECTS_FREE
509 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
510 {
511         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
512         struct hlist_node *node, *tmp;
513         struct debug_obj_descr *descr;
514         enum debug_obj_state state;
515         struct debug_bucket *db;
516         struct debug_obj *obj;
517         int cnt;
518
519         saddr = (unsigned long) address;
520         eaddr = saddr + size;
521         paddr = saddr & ODEBUG_CHUNK_MASK;
522         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
523         chunks >>= ODEBUG_CHUNK_SHIFT;
524
525         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
526                 db = get_bucket(paddr);
527
528 repeat:
529                 cnt = 0;
530                 spin_lock_irqsave(&db->lock, flags);
531                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
532                         cnt++;
533                         oaddr = (unsigned long) obj->object;
534                         if (oaddr < saddr || oaddr >= eaddr)
535                                 continue;
536
537                         switch (obj->state) {
538                         case ODEBUG_STATE_ACTIVE:
539                                 debug_print_object(obj, "free");
540                                 descr = obj->descr;
541                                 state = obj->state;
542                                 spin_unlock_irqrestore(&db->lock, flags);
543                                 debug_object_fixup(descr->fixup_free,
544                                                    (void *) oaddr, state);
545                                 goto repeat;
546                         default:
547                                 hlist_del(&obj->node);
548                                 free_object(obj);
549                                 break;
550                         }
551                 }
552                 spin_unlock_irqrestore(&db->lock, flags);
553                 if (cnt > debug_objects_maxchain)
554                         debug_objects_maxchain = cnt;
555         }
556 }
557
558 void debug_check_no_obj_freed(const void *address, unsigned long size)
559 {
560         if (debug_objects_enabled)
561                 __debug_check_no_obj_freed(address, size);
562 }
563 #endif
564
565 #ifdef CONFIG_DEBUG_FS
566
567 static int debug_stats_show(struct seq_file *m, void *v)
568 {
569         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
570         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
571         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
572         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
573         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
574         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
575         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
576         return 0;
577 }
578
579 static int debug_stats_open(struct inode *inode, struct file *filp)
580 {
581         return single_open(filp, debug_stats_show, NULL);
582 }
583
584 static const struct file_operations debug_stats_fops = {
585         .open           = debug_stats_open,
586         .read           = seq_read,
587         .llseek         = seq_lseek,
588         .release        = single_release,
589 };
590
591 static int __init debug_objects_init_debugfs(void)
592 {
593         struct dentry *dbgdir, *dbgstats;
594
595         if (!debug_objects_enabled)
596                 return 0;
597
598         dbgdir = debugfs_create_dir("debug_objects", NULL);
599         if (!dbgdir)
600                 return -ENOMEM;
601
602         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
603                                        &debug_stats_fops);
604         if (!dbgstats)
605                 goto err;
606
607         return 0;
608
609 err:
610         debugfs_remove(dbgdir);
611
612         return -ENOMEM;
613 }
614 __initcall(debug_objects_init_debugfs);
615
616 #else
617 static inline void debug_objects_init_debugfs(void) { }
618 #endif
619
620 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
621
622 /* Random data structure for the self test */
623 struct self_test {
624         unsigned long   dummy1[6];
625         int             static_init;
626         unsigned long   dummy2[3];
627 };
628
629 static __initdata struct debug_obj_descr descr_type_test;
630
631 /*
632  * fixup_init is called when:
633  * - an active object is initialized
634  */
635 static int __init fixup_init(void *addr, enum debug_obj_state state)
636 {
637         struct self_test *obj = addr;
638
639         switch (state) {
640         case ODEBUG_STATE_ACTIVE:
641                 debug_object_deactivate(obj, &descr_type_test);
642                 debug_object_init(obj, &descr_type_test);
643                 return 1;
644         default:
645                 return 0;
646         }
647 }
648
649 /*
650  * fixup_activate is called when:
651  * - an active object is activated
652  * - an unknown object is activated (might be a statically initialized object)
653  */
654 static int __init fixup_activate(void *addr, enum debug_obj_state state)
655 {
656         struct self_test *obj = addr;
657
658         switch (state) {
659         case ODEBUG_STATE_NOTAVAILABLE:
660                 if (obj->static_init == 1) {
661                         debug_object_init(obj, &descr_type_test);
662                         debug_object_activate(obj, &descr_type_test);
663                         /*
664                          * Real code should return 0 here ! This is
665                          * not a fixup of some bad behaviour. We
666                          * merily call the debug_init function to keep
667                          * track of the object.
668                          */
669                         return 1;
670                 } else {
671                         /* Real code needs to emit a warning here */
672                 }
673                 return 0;
674
675         case ODEBUG_STATE_ACTIVE:
676                 debug_object_deactivate(obj, &descr_type_test);
677                 debug_object_activate(obj, &descr_type_test);
678                 return 1;
679
680         default:
681                 return 0;
682         }
683 }
684
685 /*
686  * fixup_destroy is called when:
687  * - an active object is destroyed
688  */
689 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
690 {
691         struct self_test *obj = addr;
692
693         switch (state) {
694         case ODEBUG_STATE_ACTIVE:
695                 debug_object_deactivate(obj, &descr_type_test);
696                 debug_object_destroy(obj, &descr_type_test);
697                 return 1;
698         default:
699                 return 0;
700         }
701 }
702
703 /*
704  * fixup_free is called when:
705  * - an active object is freed
706  */
707 static int __init fixup_free(void *addr, enum debug_obj_state state)
708 {
709         struct self_test *obj = addr;
710
711         switch (state) {
712         case ODEBUG_STATE_ACTIVE:
713                 debug_object_deactivate(obj, &descr_type_test);
714                 debug_object_free(obj, &descr_type_test);
715                 return 1;
716         default:
717                 return 0;
718         }
719 }
720
721 static int
722 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
723 {
724         struct debug_bucket *db;
725         struct debug_obj *obj;
726         unsigned long flags;
727         int res = -EINVAL;
728
729         db = get_bucket((unsigned long) addr);
730
731         spin_lock_irqsave(&db->lock, flags);
732
733         obj = lookup_object(addr, db);
734         if (!obj && state != ODEBUG_STATE_NONE) {
735                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
736                 goto out;
737         }
738         if (obj && obj->state != state) {
739                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
740                        obj->state, state);
741                 goto out;
742         }
743         if (fixups != debug_objects_fixups) {
744                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
745                        fixups, debug_objects_fixups);
746                 goto out;
747         }
748         if (warnings != debug_objects_warnings) {
749                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
750                        warnings, debug_objects_warnings);
751                 goto out;
752         }
753         res = 0;
754 out:
755         spin_unlock_irqrestore(&db->lock, flags);
756         if (res)
757                 debug_objects_enabled = 0;
758         return res;
759 }
760
761 static __initdata struct debug_obj_descr descr_type_test = {
762         .name                   = "selftest",
763         .fixup_init             = fixup_init,
764         .fixup_activate         = fixup_activate,
765         .fixup_destroy          = fixup_destroy,
766         .fixup_free             = fixup_free,
767 };
768
769 static __initdata struct self_test obj = { .static_init = 0 };
770
771 static void __init debug_objects_selftest(void)
772 {
773         int fixups, oldfixups, warnings, oldwarnings;
774         unsigned long flags;
775
776         local_irq_save(flags);
777
778         fixups = oldfixups = debug_objects_fixups;
779         warnings = oldwarnings = debug_objects_warnings;
780         descr_test = &descr_type_test;
781
782         debug_object_init(&obj, &descr_type_test);
783         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
784                 goto out;
785         debug_object_activate(&obj, &descr_type_test);
786         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
787                 goto out;
788         debug_object_activate(&obj, &descr_type_test);
789         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
790                 goto out;
791         debug_object_deactivate(&obj, &descr_type_test);
792         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
793                 goto out;
794         debug_object_destroy(&obj, &descr_type_test);
795         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
796                 goto out;
797         debug_object_init(&obj, &descr_type_test);
798         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
799                 goto out;
800         debug_object_activate(&obj, &descr_type_test);
801         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
802                 goto out;
803         debug_object_deactivate(&obj, &descr_type_test);
804         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
805                 goto out;
806         debug_object_free(&obj, &descr_type_test);
807         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
808                 goto out;
809
810         obj.static_init = 1;
811         debug_object_activate(&obj, &descr_type_test);
812         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
813                 goto out;
814         debug_object_init(&obj, &descr_type_test);
815         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
816                 goto out;
817         debug_object_free(&obj, &descr_type_test);
818         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
819                 goto out;
820
821 #ifdef CONFIG_DEBUG_OBJECTS_FREE
822         debug_object_init(&obj, &descr_type_test);
823         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
824                 goto out;
825         debug_object_activate(&obj, &descr_type_test);
826         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
827                 goto out;
828         __debug_check_no_obj_freed(&obj, sizeof(obj));
829         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
830                 goto out;
831 #endif
832         printk(KERN_INFO "ODEBUG: selftest passed\n");
833
834 out:
835         debug_objects_fixups = oldfixups;
836         debug_objects_warnings = oldwarnings;
837         descr_test = NULL;
838
839         local_irq_restore(flags);
840 }
841 #else
842 static inline void debug_objects_selftest(void) { }
843 #endif
844
845 /*
846  * Called during early boot to initialize the hash buckets and link
847  * the static object pool objects into the poll list. After this call
848  * the object tracker is fully operational.
849  */
850 void __init debug_objects_early_init(void)
851 {
852         int i;
853
854         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
855                 spin_lock_init(&obj_hash[i].lock);
856
857         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
858                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
859 }
860
861 /*
862  * Called after the kmem_caches are functional to setup a dedicated
863  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
864  * prevents that the debug code is called on kmem_cache_free() for the
865  * debug tracker objects to avoid recursive calls.
866  */
867 void __init debug_objects_mem_init(void)
868 {
869         if (!debug_objects_enabled)
870                 return;
871
872         obj_cache = kmem_cache_create("debug_objects_cache",
873                                       sizeof (struct debug_obj), 0,
874                                       SLAB_DEBUG_OBJECTS, NULL);
875
876         if (!obj_cache)
877                 debug_objects_enabled = 0;
878         else
879                 debug_objects_selftest();
880 }