add a helper function to test if an object is on the stack
[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                 printk(KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
209                        obj_states[obj->state], obj->descr->name);
210                 WARN_ON(1);
211         }
212         debug_objects_warnings++;
213 }
214
215 /*
216  * Try to repair the damage, so we have a better chance to get useful
217  * debug output.
218  */
219 static void
220 debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
221                    void * addr, enum debug_obj_state state)
222 {
223         if (fixup)
224                 debug_objects_fixups += fixup(addr, state);
225 }
226
227 static void debug_object_is_on_stack(void *addr, int onstack)
228 {
229         int is_on_stack;
230         static int limit;
231
232         if (limit > 4)
233                 return;
234
235         is_on_stack = object_is_on_stack(addr);
236         if (is_on_stack == onstack)
237                 return;
238
239         limit++;
240         if (is_on_stack)
241                 printk(KERN_WARNING
242                        "ODEBUG: object is on stack, but not annotated\n");
243         else
244                 printk(KERN_WARNING
245                        "ODEBUG: object is not on stack, but annotated\n");
246         WARN_ON(1);
247 }
248
249 static void
250 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
251 {
252         enum debug_obj_state state;
253         struct debug_bucket *db;
254         struct debug_obj *obj;
255         unsigned long flags;
256
257         fill_pool();
258
259         db = get_bucket((unsigned long) addr);
260
261         spin_lock_irqsave(&db->lock, flags);
262
263         obj = lookup_object(addr, db);
264         if (!obj) {
265                 obj = alloc_object(addr, db, descr);
266                 if (!obj) {
267                         debug_objects_enabled = 0;
268                         spin_unlock_irqrestore(&db->lock, flags);
269                         debug_objects_oom();
270                         return;
271                 }
272                 debug_object_is_on_stack(addr, onstack);
273         }
274
275         switch (obj->state) {
276         case ODEBUG_STATE_NONE:
277         case ODEBUG_STATE_INIT:
278         case ODEBUG_STATE_INACTIVE:
279                 obj->state = ODEBUG_STATE_INIT;
280                 break;
281
282         case ODEBUG_STATE_ACTIVE:
283                 debug_print_object(obj, "init");
284                 state = obj->state;
285                 spin_unlock_irqrestore(&db->lock, flags);
286                 debug_object_fixup(descr->fixup_init, addr, state);
287                 return;
288
289         case ODEBUG_STATE_DESTROYED:
290                 debug_print_object(obj, "init");
291                 break;
292         default:
293                 break;
294         }
295
296         spin_unlock_irqrestore(&db->lock, flags);
297 }
298
299 /**
300  * debug_object_init - debug checks when an object is initialized
301  * @addr:       address of the object
302  * @descr:      pointer to an object specific debug description structure
303  */
304 void debug_object_init(void *addr, struct debug_obj_descr *descr)
305 {
306         if (!debug_objects_enabled)
307                 return;
308
309         __debug_object_init(addr, descr, 0);
310 }
311
312 /**
313  * debug_object_init_on_stack - debug checks when an object on stack is
314  *                              initialized
315  * @addr:       address of the object
316  * @descr:      pointer to an object specific debug description structure
317  */
318 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
319 {
320         if (!debug_objects_enabled)
321                 return;
322
323         __debug_object_init(addr, descr, 1);
324 }
325
326 /**
327  * debug_object_activate - debug checks when an object is activated
328  * @addr:       address of the object
329  * @descr:      pointer to an object specific debug description structure
330  */
331 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
332 {
333         enum debug_obj_state state;
334         struct debug_bucket *db;
335         struct debug_obj *obj;
336         unsigned long flags;
337
338         if (!debug_objects_enabled)
339                 return;
340
341         db = get_bucket((unsigned long) addr);
342
343         spin_lock_irqsave(&db->lock, flags);
344
345         obj = lookup_object(addr, db);
346         if (obj) {
347                 switch (obj->state) {
348                 case ODEBUG_STATE_INIT:
349                 case ODEBUG_STATE_INACTIVE:
350                         obj->state = ODEBUG_STATE_ACTIVE;
351                         break;
352
353                 case ODEBUG_STATE_ACTIVE:
354                         debug_print_object(obj, "activate");
355                         state = obj->state;
356                         spin_unlock_irqrestore(&db->lock, flags);
357                         debug_object_fixup(descr->fixup_activate, addr, state);
358                         return;
359
360                 case ODEBUG_STATE_DESTROYED:
361                         debug_print_object(obj, "activate");
362                         break;
363                 default:
364                         break;
365                 }
366                 spin_unlock_irqrestore(&db->lock, flags);
367                 return;
368         }
369
370         spin_unlock_irqrestore(&db->lock, flags);
371         /*
372          * This happens when a static object is activated. We
373          * let the type specific code decide whether this is
374          * true or not.
375          */
376         debug_object_fixup(descr->fixup_activate, addr,
377                            ODEBUG_STATE_NOTAVAILABLE);
378 }
379
380 /**
381  * debug_object_deactivate - debug checks when an object is deactivated
382  * @addr:       address of the object
383  * @descr:      pointer to an object specific debug description structure
384  */
385 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
386 {
387         struct debug_bucket *db;
388         struct debug_obj *obj;
389         unsigned long flags;
390
391         if (!debug_objects_enabled)
392                 return;
393
394         db = get_bucket((unsigned long) addr);
395
396         spin_lock_irqsave(&db->lock, flags);
397
398         obj = lookup_object(addr, db);
399         if (obj) {
400                 switch (obj->state) {
401                 case ODEBUG_STATE_INIT:
402                 case ODEBUG_STATE_INACTIVE:
403                 case ODEBUG_STATE_ACTIVE:
404                         obj->state = ODEBUG_STATE_INACTIVE;
405                         break;
406
407                 case ODEBUG_STATE_DESTROYED:
408                         debug_print_object(obj, "deactivate");
409                         break;
410                 default:
411                         break;
412                 }
413         } else {
414                 struct debug_obj o = { .object = addr,
415                                        .state = ODEBUG_STATE_NOTAVAILABLE,
416                                        .descr = descr };
417
418                 debug_print_object(&o, "deactivate");
419         }
420
421         spin_unlock_irqrestore(&db->lock, flags);
422 }
423
424 /**
425  * debug_object_destroy - debug checks when an object is destroyed
426  * @addr:       address of the object
427  * @descr:      pointer to an object specific debug description structure
428  */
429 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
430 {
431         enum debug_obj_state state;
432         struct debug_bucket *db;
433         struct debug_obj *obj;
434         unsigned long flags;
435
436         if (!debug_objects_enabled)
437                 return;
438
439         db = get_bucket((unsigned long) addr);
440
441         spin_lock_irqsave(&db->lock, flags);
442
443         obj = lookup_object(addr, db);
444         if (!obj)
445                 goto out_unlock;
446
447         switch (obj->state) {
448         case ODEBUG_STATE_NONE:
449         case ODEBUG_STATE_INIT:
450         case ODEBUG_STATE_INACTIVE:
451                 obj->state = ODEBUG_STATE_DESTROYED;
452                 break;
453         case ODEBUG_STATE_ACTIVE:
454                 debug_print_object(obj, "destroy");
455                 state = obj->state;
456                 spin_unlock_irqrestore(&db->lock, flags);
457                 debug_object_fixup(descr->fixup_destroy, addr, state);
458                 return;
459
460         case ODEBUG_STATE_DESTROYED:
461                 debug_print_object(obj, "destroy");
462                 break;
463         default:
464                 break;
465         }
466 out_unlock:
467         spin_unlock_irqrestore(&db->lock, flags);
468 }
469
470 /**
471  * debug_object_free - debug checks when an object is freed
472  * @addr:       address of the object
473  * @descr:      pointer to an object specific debug description structure
474  */
475 void debug_object_free(void *addr, struct debug_obj_descr *descr)
476 {
477         enum debug_obj_state state;
478         struct debug_bucket *db;
479         struct debug_obj *obj;
480         unsigned long flags;
481
482         if (!debug_objects_enabled)
483                 return;
484
485         db = get_bucket((unsigned long) addr);
486
487         spin_lock_irqsave(&db->lock, flags);
488
489         obj = lookup_object(addr, db);
490         if (!obj)
491                 goto out_unlock;
492
493         switch (obj->state) {
494         case ODEBUG_STATE_ACTIVE:
495                 debug_print_object(obj, "free");
496                 state = obj->state;
497                 spin_unlock_irqrestore(&db->lock, flags);
498                 debug_object_fixup(descr->fixup_free, addr, state);
499                 return;
500         default:
501                 hlist_del(&obj->node);
502                 free_object(obj);
503                 break;
504         }
505 out_unlock:
506         spin_unlock_irqrestore(&db->lock, flags);
507 }
508
509 #ifdef CONFIG_DEBUG_OBJECTS_FREE
510 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
511 {
512         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
513         struct hlist_node *node, *tmp;
514         struct debug_obj_descr *descr;
515         enum debug_obj_state state;
516         struct debug_bucket *db;
517         struct debug_obj *obj;
518         int cnt;
519
520         saddr = (unsigned long) address;
521         eaddr = saddr + size;
522         paddr = saddr & ODEBUG_CHUNK_MASK;
523         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
524         chunks >>= ODEBUG_CHUNK_SHIFT;
525
526         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
527                 db = get_bucket(paddr);
528
529 repeat:
530                 cnt = 0;
531                 spin_lock_irqsave(&db->lock, flags);
532                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
533                         cnt++;
534                         oaddr = (unsigned long) obj->object;
535                         if (oaddr < saddr || oaddr >= eaddr)
536                                 continue;
537
538                         switch (obj->state) {
539                         case ODEBUG_STATE_ACTIVE:
540                                 debug_print_object(obj, "free");
541                                 descr = obj->descr;
542                                 state = obj->state;
543                                 spin_unlock_irqrestore(&db->lock, flags);
544                                 debug_object_fixup(descr->fixup_free,
545                                                    (void *) oaddr, state);
546                                 goto repeat;
547                         default:
548                                 hlist_del(&obj->node);
549                                 free_object(obj);
550                                 break;
551                         }
552                 }
553                 spin_unlock_irqrestore(&db->lock, flags);
554                 if (cnt > debug_objects_maxchain)
555                         debug_objects_maxchain = cnt;
556         }
557 }
558
559 void debug_check_no_obj_freed(const void *address, unsigned long size)
560 {
561         if (debug_objects_enabled)
562                 __debug_check_no_obj_freed(address, size);
563 }
564 #endif
565
566 #ifdef CONFIG_DEBUG_FS
567
568 static int debug_stats_show(struct seq_file *m, void *v)
569 {
570         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
571         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
572         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
573         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
574         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
575         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
576         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
577         return 0;
578 }
579
580 static int debug_stats_open(struct inode *inode, struct file *filp)
581 {
582         return single_open(filp, debug_stats_show, NULL);
583 }
584
585 static const struct file_operations debug_stats_fops = {
586         .open           = debug_stats_open,
587         .read           = seq_read,
588         .llseek         = seq_lseek,
589         .release        = single_release,
590 };
591
592 static int __init debug_objects_init_debugfs(void)
593 {
594         struct dentry *dbgdir, *dbgstats;
595
596         if (!debug_objects_enabled)
597                 return 0;
598
599         dbgdir = debugfs_create_dir("debug_objects", NULL);
600         if (!dbgdir)
601                 return -ENOMEM;
602
603         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
604                                        &debug_stats_fops);
605         if (!dbgstats)
606                 goto err;
607
608         return 0;
609
610 err:
611         debugfs_remove(dbgdir);
612
613         return -ENOMEM;
614 }
615 __initcall(debug_objects_init_debugfs);
616
617 #else
618 static inline void debug_objects_init_debugfs(void) { }
619 #endif
620
621 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
622
623 /* Random data structure for the self test */
624 struct self_test {
625         unsigned long   dummy1[6];
626         int             static_init;
627         unsigned long   dummy2[3];
628 };
629
630 static __initdata struct debug_obj_descr descr_type_test;
631
632 /*
633  * fixup_init is called when:
634  * - an active object is initialized
635  */
636 static int __init fixup_init(void *addr, enum debug_obj_state state)
637 {
638         struct self_test *obj = addr;
639
640         switch (state) {
641         case ODEBUG_STATE_ACTIVE:
642                 debug_object_deactivate(obj, &descr_type_test);
643                 debug_object_init(obj, &descr_type_test);
644                 return 1;
645         default:
646                 return 0;
647         }
648 }
649
650 /*
651  * fixup_activate is called when:
652  * - an active object is activated
653  * - an unknown object is activated (might be a statically initialized object)
654  */
655 static int __init fixup_activate(void *addr, enum debug_obj_state state)
656 {
657         struct self_test *obj = addr;
658
659         switch (state) {
660         case ODEBUG_STATE_NOTAVAILABLE:
661                 if (obj->static_init == 1) {
662                         debug_object_init(obj, &descr_type_test);
663                         debug_object_activate(obj, &descr_type_test);
664                         /*
665                          * Real code should return 0 here ! This is
666                          * not a fixup of some bad behaviour. We
667                          * merily call the debug_init function to keep
668                          * track of the object.
669                          */
670                         return 1;
671                 } else {
672                         /* Real code needs to emit a warning here */
673                 }
674                 return 0;
675
676         case ODEBUG_STATE_ACTIVE:
677                 debug_object_deactivate(obj, &descr_type_test);
678                 debug_object_activate(obj, &descr_type_test);
679                 return 1;
680
681         default:
682                 return 0;
683         }
684 }
685
686 /*
687  * fixup_destroy is called when:
688  * - an active object is destroyed
689  */
690 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
691 {
692         struct self_test *obj = addr;
693
694         switch (state) {
695         case ODEBUG_STATE_ACTIVE:
696                 debug_object_deactivate(obj, &descr_type_test);
697                 debug_object_destroy(obj, &descr_type_test);
698                 return 1;
699         default:
700                 return 0;
701         }
702 }
703
704 /*
705  * fixup_free is called when:
706  * - an active object is freed
707  */
708 static int __init fixup_free(void *addr, enum debug_obj_state state)
709 {
710         struct self_test *obj = addr;
711
712         switch (state) {
713         case ODEBUG_STATE_ACTIVE:
714                 debug_object_deactivate(obj, &descr_type_test);
715                 debug_object_free(obj, &descr_type_test);
716                 return 1;
717         default:
718                 return 0;
719         }
720 }
721
722 static int
723 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
724 {
725         struct debug_bucket *db;
726         struct debug_obj *obj;
727         unsigned long flags;
728         int res = -EINVAL;
729
730         db = get_bucket((unsigned long) addr);
731
732         spin_lock_irqsave(&db->lock, flags);
733
734         obj = lookup_object(addr, db);
735         if (!obj && state != ODEBUG_STATE_NONE) {
736                 printk(KERN_ERR "ODEBUG: selftest object not found\n");
737                 WARN_ON(1);
738                 goto out;
739         }
740         if (obj && obj->state != state) {
741                 printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
742                        obj->state, state);
743                 WARN_ON(1);
744                 goto out;
745         }
746         if (fixups != debug_objects_fixups) {
747                 printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
748                        fixups, debug_objects_fixups);
749                 WARN_ON(1);
750                 goto out;
751         }
752         if (warnings != debug_objects_warnings) {
753                 printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
754                        warnings, debug_objects_warnings);
755                 WARN_ON(1);
756                 goto out;
757         }
758         res = 0;
759 out:
760         spin_unlock_irqrestore(&db->lock, flags);
761         if (res)
762                 debug_objects_enabled = 0;
763         return res;
764 }
765
766 static __initdata struct debug_obj_descr descr_type_test = {
767         .name                   = "selftest",
768         .fixup_init             = fixup_init,
769         .fixup_activate         = fixup_activate,
770         .fixup_destroy          = fixup_destroy,
771         .fixup_free             = fixup_free,
772 };
773
774 static __initdata struct self_test obj = { .static_init = 0 };
775
776 static void __init debug_objects_selftest(void)
777 {
778         int fixups, oldfixups, warnings, oldwarnings;
779         unsigned long flags;
780
781         local_irq_save(flags);
782
783         fixups = oldfixups = debug_objects_fixups;
784         warnings = oldwarnings = debug_objects_warnings;
785         descr_test = &descr_type_test;
786
787         debug_object_init(&obj, &descr_type_test);
788         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
789                 goto out;
790         debug_object_activate(&obj, &descr_type_test);
791         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
792                 goto out;
793         debug_object_activate(&obj, &descr_type_test);
794         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
795                 goto out;
796         debug_object_deactivate(&obj, &descr_type_test);
797         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
798                 goto out;
799         debug_object_destroy(&obj, &descr_type_test);
800         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
801                 goto out;
802         debug_object_init(&obj, &descr_type_test);
803         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
804                 goto out;
805         debug_object_activate(&obj, &descr_type_test);
806         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
807                 goto out;
808         debug_object_deactivate(&obj, &descr_type_test);
809         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
810                 goto out;
811         debug_object_free(&obj, &descr_type_test);
812         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
813                 goto out;
814
815         obj.static_init = 1;
816         debug_object_activate(&obj, &descr_type_test);
817         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
818                 goto out;
819         debug_object_init(&obj, &descr_type_test);
820         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
821                 goto out;
822         debug_object_free(&obj, &descr_type_test);
823         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
824                 goto out;
825
826 #ifdef CONFIG_DEBUG_OBJECTS_FREE
827         debug_object_init(&obj, &descr_type_test);
828         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
829                 goto out;
830         debug_object_activate(&obj, &descr_type_test);
831         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
832                 goto out;
833         __debug_check_no_obj_freed(&obj, sizeof(obj));
834         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
835                 goto out;
836 #endif
837         printk(KERN_INFO "ODEBUG: selftest passed\n");
838
839 out:
840         debug_objects_fixups = oldfixups;
841         debug_objects_warnings = oldwarnings;
842         descr_test = NULL;
843
844         local_irq_restore(flags);
845 }
846 #else
847 static inline void debug_objects_selftest(void) { }
848 #endif
849
850 /*
851  * Called during early boot to initialize the hash buckets and link
852  * the static object pool objects into the poll list. After this call
853  * the object tracker is fully operational.
854  */
855 void __init debug_objects_early_init(void)
856 {
857         int i;
858
859         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
860                 spin_lock_init(&obj_hash[i].lock);
861
862         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
863                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
864 }
865
866 /*
867  * Called after the kmem_caches are functional to setup a dedicated
868  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
869  * prevents that the debug code is called on kmem_cache_free() for the
870  * debug tracker objects to avoid recursive calls.
871  */
872 void __init debug_objects_mem_init(void)
873 {
874         if (!debug_objects_enabled)
875                 return;
876
877         obj_cache = kmem_cache_create("debug_objects_cache",
878                                       sizeof (struct debug_obj), 0,
879                                       SLAB_DEBUG_OBJECTS, NULL);
880
881         if (!obj_cache)
882                 debug_objects_enabled = 0;
883         else
884                 debug_objects_selftest();
885 }