Merge branch 'core/rcu' into core/rcu-for-linus
[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         void *stack = current->stack;
230         int is_on_stack;
231         static int limit;
232
233         if (limit > 4)
234                 return;
235
236         is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE));
237
238         if (is_on_stack == onstack)
239                 return;
240
241         limit++;
242         if (is_on_stack)
243                 printk(KERN_WARNING
244                        "ODEBUG: object is on stack, but not annotated\n");
245         else
246                 printk(KERN_WARNING
247                        "ODEBUG: object is not on stack, but annotated\n");
248         WARN_ON(1);
249 }
250
251 static void
252 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
253 {
254         enum debug_obj_state state;
255         struct debug_bucket *db;
256         struct debug_obj *obj;
257         unsigned long flags;
258
259         fill_pool();
260
261         db = get_bucket((unsigned long) addr);
262
263         spin_lock_irqsave(&db->lock, flags);
264
265         obj = lookup_object(addr, db);
266         if (!obj) {
267                 obj = alloc_object(addr, db, descr);
268                 if (!obj) {
269                         debug_objects_enabled = 0;
270                         spin_unlock_irqrestore(&db->lock, flags);
271                         debug_objects_oom();
272                         return;
273                 }
274                 debug_object_is_on_stack(addr, onstack);
275         }
276
277         switch (obj->state) {
278         case ODEBUG_STATE_NONE:
279         case ODEBUG_STATE_INIT:
280         case ODEBUG_STATE_INACTIVE:
281                 obj->state = ODEBUG_STATE_INIT;
282                 break;
283
284         case ODEBUG_STATE_ACTIVE:
285                 debug_print_object(obj, "init");
286                 state = obj->state;
287                 spin_unlock_irqrestore(&db->lock, flags);
288                 debug_object_fixup(descr->fixup_init, addr, state);
289                 return;
290
291         case ODEBUG_STATE_DESTROYED:
292                 debug_print_object(obj, "init");
293                 break;
294         default:
295                 break;
296         }
297
298         spin_unlock_irqrestore(&db->lock, flags);
299 }
300
301 /**
302  * debug_object_init - debug checks when an object is initialized
303  * @addr:       address of the object
304  * @descr:      pointer to an object specific debug description structure
305  */
306 void debug_object_init(void *addr, struct debug_obj_descr *descr)
307 {
308         if (!debug_objects_enabled)
309                 return;
310
311         __debug_object_init(addr, descr, 0);
312 }
313
314 /**
315  * debug_object_init_on_stack - debug checks when an object on stack is
316  *                              initialized
317  * @addr:       address of the object
318  * @descr:      pointer to an object specific debug description structure
319  */
320 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
321 {
322         if (!debug_objects_enabled)
323                 return;
324
325         __debug_object_init(addr, descr, 1);
326 }
327
328 /**
329  * debug_object_activate - debug checks when an object is activated
330  * @addr:       address of the object
331  * @descr:      pointer to an object specific debug description structure
332  */
333 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
334 {
335         enum debug_obj_state state;
336         struct debug_bucket *db;
337         struct debug_obj *obj;
338         unsigned long flags;
339
340         if (!debug_objects_enabled)
341                 return;
342
343         db = get_bucket((unsigned long) addr);
344
345         spin_lock_irqsave(&db->lock, flags);
346
347         obj = lookup_object(addr, db);
348         if (obj) {
349                 switch (obj->state) {
350                 case ODEBUG_STATE_INIT:
351                 case ODEBUG_STATE_INACTIVE:
352                         obj->state = ODEBUG_STATE_ACTIVE;
353                         break;
354
355                 case ODEBUG_STATE_ACTIVE:
356                         debug_print_object(obj, "activate");
357                         state = obj->state;
358                         spin_unlock_irqrestore(&db->lock, flags);
359                         debug_object_fixup(descr->fixup_activate, addr, state);
360                         return;
361
362                 case ODEBUG_STATE_DESTROYED:
363                         debug_print_object(obj, "activate");
364                         break;
365                 default:
366                         break;
367                 }
368                 spin_unlock_irqrestore(&db->lock, flags);
369                 return;
370         }
371
372         spin_unlock_irqrestore(&db->lock, flags);
373         /*
374          * This happens when a static object is activated. We
375          * let the type specific code decide whether this is
376          * true or not.
377          */
378         debug_object_fixup(descr->fixup_activate, addr,
379                            ODEBUG_STATE_NOTAVAILABLE);
380 }
381
382 /**
383  * debug_object_deactivate - debug checks when an object is deactivated
384  * @addr:       address of the object
385  * @descr:      pointer to an object specific debug description structure
386  */
387 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
388 {
389         struct debug_bucket *db;
390         struct debug_obj *obj;
391         unsigned long flags;
392
393         if (!debug_objects_enabled)
394                 return;
395
396         db = get_bucket((unsigned long) addr);
397
398         spin_lock_irqsave(&db->lock, flags);
399
400         obj = lookup_object(addr, db);
401         if (obj) {
402                 switch (obj->state) {
403                 case ODEBUG_STATE_INIT:
404                 case ODEBUG_STATE_INACTIVE:
405                 case ODEBUG_STATE_ACTIVE:
406                         obj->state = ODEBUG_STATE_INACTIVE;
407                         break;
408
409                 case ODEBUG_STATE_DESTROYED:
410                         debug_print_object(obj, "deactivate");
411                         break;
412                 default:
413                         break;
414                 }
415         } else {
416                 struct debug_obj o = { .object = addr,
417                                        .state = ODEBUG_STATE_NOTAVAILABLE,
418                                        .descr = descr };
419
420                 debug_print_object(&o, "deactivate");
421         }
422
423         spin_unlock_irqrestore(&db->lock, flags);
424 }
425
426 /**
427  * debug_object_destroy - debug checks when an object is destroyed
428  * @addr:       address of the object
429  * @descr:      pointer to an object specific debug description structure
430  */
431 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
432 {
433         enum debug_obj_state state;
434         struct debug_bucket *db;
435         struct debug_obj *obj;
436         unsigned long flags;
437
438         if (!debug_objects_enabled)
439                 return;
440
441         db = get_bucket((unsigned long) addr);
442
443         spin_lock_irqsave(&db->lock, flags);
444
445         obj = lookup_object(addr, db);
446         if (!obj)
447                 goto out_unlock;
448
449         switch (obj->state) {
450         case ODEBUG_STATE_NONE:
451         case ODEBUG_STATE_INIT:
452         case ODEBUG_STATE_INACTIVE:
453                 obj->state = ODEBUG_STATE_DESTROYED;
454                 break;
455         case ODEBUG_STATE_ACTIVE:
456                 debug_print_object(obj, "destroy");
457                 state = obj->state;
458                 spin_unlock_irqrestore(&db->lock, flags);
459                 debug_object_fixup(descr->fixup_destroy, addr, state);
460                 return;
461
462         case ODEBUG_STATE_DESTROYED:
463                 debug_print_object(obj, "destroy");
464                 break;
465         default:
466                 break;
467         }
468 out_unlock:
469         spin_unlock_irqrestore(&db->lock, flags);
470 }
471
472 /**
473  * debug_object_free - debug checks when an object is freed
474  * @addr:       address of the object
475  * @descr:      pointer to an object specific debug description structure
476  */
477 void debug_object_free(void *addr, struct debug_obj_descr *descr)
478 {
479         enum debug_obj_state state;
480         struct debug_bucket *db;
481         struct debug_obj *obj;
482         unsigned long flags;
483
484         if (!debug_objects_enabled)
485                 return;
486
487         db = get_bucket((unsigned long) addr);
488
489         spin_lock_irqsave(&db->lock, flags);
490
491         obj = lookup_object(addr, db);
492         if (!obj)
493                 goto out_unlock;
494
495         switch (obj->state) {
496         case ODEBUG_STATE_ACTIVE:
497                 debug_print_object(obj, "free");
498                 state = obj->state;
499                 spin_unlock_irqrestore(&db->lock, flags);
500                 debug_object_fixup(descr->fixup_free, addr, state);
501                 return;
502         default:
503                 hlist_del(&obj->node);
504                 free_object(obj);
505                 break;
506         }
507 out_unlock:
508         spin_unlock_irqrestore(&db->lock, flags);
509 }
510
511 #ifdef CONFIG_DEBUG_OBJECTS_FREE
512 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
513 {
514         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
515         struct hlist_node *node, *tmp;
516         struct debug_obj_descr *descr;
517         enum debug_obj_state state;
518         struct debug_bucket *db;
519         struct debug_obj *obj;
520         int cnt;
521
522         saddr = (unsigned long) address;
523         eaddr = saddr + size;
524         paddr = saddr & ODEBUG_CHUNK_MASK;
525         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
526         chunks >>= ODEBUG_CHUNK_SHIFT;
527
528         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
529                 db = get_bucket(paddr);
530
531 repeat:
532                 cnt = 0;
533                 spin_lock_irqsave(&db->lock, flags);
534                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
535                         cnt++;
536                         oaddr = (unsigned long) obj->object;
537                         if (oaddr < saddr || oaddr >= eaddr)
538                                 continue;
539
540                         switch (obj->state) {
541                         case ODEBUG_STATE_ACTIVE:
542                                 debug_print_object(obj, "free");
543                                 descr = obj->descr;
544                                 state = obj->state;
545                                 spin_unlock_irqrestore(&db->lock, flags);
546                                 debug_object_fixup(descr->fixup_free,
547                                                    (void *) oaddr, state);
548                                 goto repeat;
549                         default:
550                                 hlist_del(&obj->node);
551                                 free_object(obj);
552                                 break;
553                         }
554                 }
555                 spin_unlock_irqrestore(&db->lock, flags);
556                 if (cnt > debug_objects_maxchain)
557                         debug_objects_maxchain = cnt;
558         }
559 }
560
561 void debug_check_no_obj_freed(const void *address, unsigned long size)
562 {
563         if (debug_objects_enabled)
564                 __debug_check_no_obj_freed(address, size);
565 }
566 #endif
567
568 #ifdef CONFIG_DEBUG_FS
569
570 static int debug_stats_show(struct seq_file *m, void *v)
571 {
572         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
573         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
574         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
575         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
576         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
577         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
578         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
579         return 0;
580 }
581
582 static int debug_stats_open(struct inode *inode, struct file *filp)
583 {
584         return single_open(filp, debug_stats_show, NULL);
585 }
586
587 static const struct file_operations debug_stats_fops = {
588         .open           = debug_stats_open,
589         .read           = seq_read,
590         .llseek         = seq_lseek,
591         .release        = single_release,
592 };
593
594 static int __init debug_objects_init_debugfs(void)
595 {
596         struct dentry *dbgdir, *dbgstats;
597
598         if (!debug_objects_enabled)
599                 return 0;
600
601         dbgdir = debugfs_create_dir("debug_objects", NULL);
602         if (!dbgdir)
603                 return -ENOMEM;
604
605         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
606                                        &debug_stats_fops);
607         if (!dbgstats)
608                 goto err;
609
610         return 0;
611
612 err:
613         debugfs_remove(dbgdir);
614
615         return -ENOMEM;
616 }
617 __initcall(debug_objects_init_debugfs);
618
619 #else
620 static inline void debug_objects_init_debugfs(void) { }
621 #endif
622
623 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
624
625 /* Random data structure for the self test */
626 struct self_test {
627         unsigned long   dummy1[6];
628         int             static_init;
629         unsigned long   dummy2[3];
630 };
631
632 static __initdata struct debug_obj_descr descr_type_test;
633
634 /*
635  * fixup_init is called when:
636  * - an active object is initialized
637  */
638 static int __init fixup_init(void *addr, enum debug_obj_state state)
639 {
640         struct self_test *obj = addr;
641
642         switch (state) {
643         case ODEBUG_STATE_ACTIVE:
644                 debug_object_deactivate(obj, &descr_type_test);
645                 debug_object_init(obj, &descr_type_test);
646                 return 1;
647         default:
648                 return 0;
649         }
650 }
651
652 /*
653  * fixup_activate is called when:
654  * - an active object is activated
655  * - an unknown object is activated (might be a statically initialized object)
656  */
657 static int __init fixup_activate(void *addr, enum debug_obj_state state)
658 {
659         struct self_test *obj = addr;
660
661         switch (state) {
662         case ODEBUG_STATE_NOTAVAILABLE:
663                 if (obj->static_init == 1) {
664                         debug_object_init(obj, &descr_type_test);
665                         debug_object_activate(obj, &descr_type_test);
666                         /*
667                          * Real code should return 0 here ! This is
668                          * not a fixup of some bad behaviour. We
669                          * merily call the debug_init function to keep
670                          * track of the object.
671                          */
672                         return 1;
673                 } else {
674                         /* Real code needs to emit a warning here */
675                 }
676                 return 0;
677
678         case ODEBUG_STATE_ACTIVE:
679                 debug_object_deactivate(obj, &descr_type_test);
680                 debug_object_activate(obj, &descr_type_test);
681                 return 1;
682
683         default:
684                 return 0;
685         }
686 }
687
688 /*
689  * fixup_destroy is called when:
690  * - an active object is destroyed
691  */
692 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
693 {
694         struct self_test *obj = addr;
695
696         switch (state) {
697         case ODEBUG_STATE_ACTIVE:
698                 debug_object_deactivate(obj, &descr_type_test);
699                 debug_object_destroy(obj, &descr_type_test);
700                 return 1;
701         default:
702                 return 0;
703         }
704 }
705
706 /*
707  * fixup_free is called when:
708  * - an active object is freed
709  */
710 static int __init fixup_free(void *addr, enum debug_obj_state state)
711 {
712         struct self_test *obj = addr;
713
714         switch (state) {
715         case ODEBUG_STATE_ACTIVE:
716                 debug_object_deactivate(obj, &descr_type_test);
717                 debug_object_free(obj, &descr_type_test);
718                 return 1;
719         default:
720                 return 0;
721         }
722 }
723
724 static int
725 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
726 {
727         struct debug_bucket *db;
728         struct debug_obj *obj;
729         unsigned long flags;
730         int res = -EINVAL;
731
732         db = get_bucket((unsigned long) addr);
733
734         spin_lock_irqsave(&db->lock, flags);
735
736         obj = lookup_object(addr, db);
737         if (!obj && state != ODEBUG_STATE_NONE) {
738                 printk(KERN_ERR "ODEBUG: selftest object not found\n");
739                 WARN_ON(1);
740                 goto out;
741         }
742         if (obj && obj->state != state) {
743                 printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
744                        obj->state, state);
745                 WARN_ON(1);
746                 goto out;
747         }
748         if (fixups != debug_objects_fixups) {
749                 printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
750                        fixups, debug_objects_fixups);
751                 WARN_ON(1);
752                 goto out;
753         }
754         if (warnings != debug_objects_warnings) {
755                 printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
756                        warnings, debug_objects_warnings);
757                 WARN_ON(1);
758                 goto out;
759         }
760         res = 0;
761 out:
762         spin_unlock_irqrestore(&db->lock, flags);
763         if (res)
764                 debug_objects_enabled = 0;
765         return res;
766 }
767
768 static __initdata struct debug_obj_descr descr_type_test = {
769         .name                   = "selftest",
770         .fixup_init             = fixup_init,
771         .fixup_activate         = fixup_activate,
772         .fixup_destroy          = fixup_destroy,
773         .fixup_free             = fixup_free,
774 };
775
776 static __initdata struct self_test obj = { .static_init = 0 };
777
778 static void __init debug_objects_selftest(void)
779 {
780         int fixups, oldfixups, warnings, oldwarnings;
781         unsigned long flags;
782
783         local_irq_save(flags);
784
785         fixups = oldfixups = debug_objects_fixups;
786         warnings = oldwarnings = debug_objects_warnings;
787         descr_test = &descr_type_test;
788
789         debug_object_init(&obj, &descr_type_test);
790         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
791                 goto out;
792         debug_object_activate(&obj, &descr_type_test);
793         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
794                 goto out;
795         debug_object_activate(&obj, &descr_type_test);
796         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
797                 goto out;
798         debug_object_deactivate(&obj, &descr_type_test);
799         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
800                 goto out;
801         debug_object_destroy(&obj, &descr_type_test);
802         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
803                 goto out;
804         debug_object_init(&obj, &descr_type_test);
805         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
806                 goto out;
807         debug_object_activate(&obj, &descr_type_test);
808         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
809                 goto out;
810         debug_object_deactivate(&obj, &descr_type_test);
811         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
812                 goto out;
813         debug_object_free(&obj, &descr_type_test);
814         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
815                 goto out;
816
817         obj.static_init = 1;
818         debug_object_activate(&obj, &descr_type_test);
819         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
820                 goto out;
821         debug_object_init(&obj, &descr_type_test);
822         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
823                 goto out;
824         debug_object_free(&obj, &descr_type_test);
825         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
826                 goto out;
827
828 #ifdef CONFIG_DEBUG_OBJECTS_FREE
829         debug_object_init(&obj, &descr_type_test);
830         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
831                 goto out;
832         debug_object_activate(&obj, &descr_type_test);
833         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
834                 goto out;
835         __debug_check_no_obj_freed(&obj, sizeof(obj));
836         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
837                 goto out;
838 #endif
839         printk(KERN_INFO "ODEBUG: selftest passed\n");
840
841 out:
842         debug_objects_fixups = oldfixups;
843         debug_objects_warnings = oldwarnings;
844         descr_test = NULL;
845
846         local_irq_restore(flags);
847 }
848 #else
849 static inline void debug_objects_selftest(void) { }
850 #endif
851
852 /*
853  * Called during early boot to initialize the hash buckets and link
854  * the static object pool objects into the poll list. After this call
855  * the object tracker is fully operational.
856  */
857 void __init debug_objects_early_init(void)
858 {
859         int i;
860
861         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
862                 spin_lock_init(&obj_hash[i].lock);
863
864         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
865                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
866 }
867
868 /*
869  * Called after the kmem_caches are functional to setup a dedicated
870  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
871  * prevents that the debug code is called on kmem_cache_free() for the
872  * debug tracker objects to avoid recursive calls.
873  */
874 void __init debug_objects_mem_init(void)
875 {
876         if (!debug_objects_enabled)
877                 return;
878
879         obj_cache = kmem_cache_create("debug_objects_cache",
880                                       sizeof (struct debug_obj), 0,
881                                       SLAB_DEBUG_OBJECTS, NULL);
882
883         if (!obj_cache)
884                 debug_objects_enabled = 0;
885         else
886                 debug_objects_selftest();
887 }