infrastructure to debug (dynamic) objects
[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
72         if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
73                 return obj_pool_free;
74
75         if (unlikely(!obj_cache))
76                 return obj_pool_free;
77
78         while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
79
80                 new = kmem_cache_zalloc(obj_cache, gfp);
81                 if (!new)
82                         return obj_pool_free;
83
84                 spin_lock(&pool_lock);
85                 hlist_add_head(&new->node, &obj_pool);
86                 obj_pool_free++;
87                 spin_unlock(&pool_lock);
88         }
89         return obj_pool_free;
90 }
91
92 /*
93  * Lookup an object in the hash bucket.
94  */
95 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
96 {
97         struct hlist_node *node;
98         struct debug_obj *obj;
99         int cnt = 0;
100
101         hlist_for_each_entry(obj, node, &b->list, node) {
102                 cnt++;
103                 if (obj->object == addr)
104                         return obj;
105         }
106         if (cnt > debug_objects_maxchain)
107                 debug_objects_maxchain = cnt;
108
109         return NULL;
110 }
111
112 /*
113  * Allocate a new object. If the pool is empty and no refill possible,
114  * 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         int retry = 0;
121
122 repeat:
123         spin_lock(&pool_lock);
124         if (obj_pool.first) {
125                 obj         = hlist_entry(obj_pool.first, typeof(*obj), node);
126
127                 obj->object = addr;
128                 obj->descr  = descr;
129                 obj->state  = ODEBUG_STATE_NONE;
130                 hlist_del(&obj->node);
131
132                 hlist_add_head(&obj->node, &b->list);
133
134                 obj_pool_used++;
135                 if (obj_pool_used > obj_pool_max_used)
136                         obj_pool_max_used = obj_pool_used;
137
138                 obj_pool_free--;
139                 if (obj_pool_free < obj_pool_min_free)
140                         obj_pool_min_free = obj_pool_free;
141         }
142         spin_unlock(&pool_lock);
143
144         if (fill_pool() && !obj && !retry++)
145                 goto repeat;
146
147         return obj;
148 }
149
150 /*
151  * Put the object back into the pool or give it back to kmem_cache:
152  */
153 static void free_object(struct debug_obj *obj)
154 {
155         unsigned long idx = (unsigned long)(obj - obj_static_pool);
156
157         if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
158                 spin_lock(&pool_lock);
159                 hlist_add_head(&obj->node, &obj_pool);
160                 obj_pool_free++;
161                 obj_pool_used--;
162                 spin_unlock(&pool_lock);
163         } else {
164                 spin_lock(&pool_lock);
165                 obj_pool_used--;
166                 spin_unlock(&pool_lock);
167                 kmem_cache_free(obj_cache, obj);
168         }
169 }
170
171 /*
172  * We run out of memory. That means we probably have tons of objects
173  * allocated.
174  */
175 static void debug_objects_oom(void)
176 {
177         struct debug_bucket *db = obj_hash;
178         struct hlist_node *node, *tmp;
179         struct debug_obj *obj;
180         unsigned long flags;
181         int i;
182
183         printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
184
185         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
186                 spin_lock_irqsave(&db->lock, flags);
187                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
188                         hlist_del(&obj->node);
189                         free_object(obj);
190                 }
191                 spin_unlock_irqrestore(&db->lock, flags);
192         }
193 }
194
195 /*
196  * We use the pfn of the address for the hash. That way we can check
197  * for freed objects simply by checking the affected bucket.
198  */
199 static struct debug_bucket *get_bucket(unsigned long addr)
200 {
201         unsigned long hash;
202
203         hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
204         return &obj_hash[hash];
205 }
206
207 static void debug_print_object(struct debug_obj *obj, char *msg)
208 {
209         static int limit;
210
211         if (limit < 5 && obj->descr != descr_test) {
212                 limit++;
213                 printk(KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
214                        obj_states[obj->state], obj->descr->name);
215                 WARN_ON(1);
216         }
217         debug_objects_warnings++;
218 }
219
220 /*
221  * Try to repair the damage, so we have a better chance to get useful
222  * debug output.
223  */
224 static void
225 debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
226                    void * addr, enum debug_obj_state state)
227 {
228         if (fixup)
229                 debug_objects_fixups += fixup(addr, state);
230 }
231
232 static void debug_object_is_on_stack(void *addr, int onstack)
233 {
234         void *stack = current->stack;
235         int is_on_stack;
236         static int limit;
237
238         if (limit > 4)
239                 return;
240
241         is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE));
242
243         if (is_on_stack == onstack)
244                 return;
245
246         limit++;
247         if (is_on_stack)
248                 printk(KERN_WARNING
249                        "ODEBUG: object is on stack, but not annotated\n");
250         else
251                 printk(KERN_WARNING
252                        "ODEBUG: object is not on stack, but annotated\n");
253         WARN_ON(1);
254 }
255
256 static void
257 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
258 {
259         enum debug_obj_state state;
260         struct debug_bucket *db;
261         struct debug_obj *obj;
262         unsigned long flags;
263
264         db = get_bucket((unsigned long) addr);
265
266         spin_lock_irqsave(&db->lock, flags);
267
268         obj = lookup_object(addr, db);
269         if (!obj) {
270                 obj = alloc_object(addr, db, descr);
271                 if (!obj) {
272                         debug_objects_enabled = 0;
273                         spin_unlock_irqrestore(&db->lock, flags);
274                         debug_objects_oom();
275                         return;
276                 }
277                 debug_object_is_on_stack(addr, onstack);
278         }
279
280         switch (obj->state) {
281         case ODEBUG_STATE_NONE:
282         case ODEBUG_STATE_INIT:
283         case ODEBUG_STATE_INACTIVE:
284                 obj->state = ODEBUG_STATE_INIT;
285                 break;
286
287         case ODEBUG_STATE_ACTIVE:
288                 debug_print_object(obj, "init");
289                 state = obj->state;
290                 spin_unlock_irqrestore(&db->lock, flags);
291                 debug_object_fixup(descr->fixup_init, addr, state);
292                 return;
293
294         case ODEBUG_STATE_DESTROYED:
295                 debug_print_object(obj, "init");
296                 break;
297         default:
298                 break;
299         }
300
301         spin_unlock_irqrestore(&db->lock, flags);
302 }
303
304 /**
305  * debug_object_init - debug checks when an object is initialized
306  * @addr:       address of the object
307  * @descr:      pointer to an object specific debug description structure
308  */
309 void debug_object_init(void *addr, struct debug_obj_descr *descr)
310 {
311         if (!debug_objects_enabled)
312                 return;
313
314         __debug_object_init(addr, descr, 0);
315 }
316
317 /**
318  * debug_object_init_on_stack - debug checks when an object on stack is
319  *                              initialized
320  * @addr:       address of the object
321  * @descr:      pointer to an object specific debug description structure
322  */
323 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
324 {
325         if (!debug_objects_enabled)
326                 return;
327
328         __debug_object_init(addr, descr, 1);
329 }
330
331 /**
332  * debug_object_activate - debug checks when an object is activated
333  * @addr:       address of the object
334  * @descr:      pointer to an object specific debug description structure
335  */
336 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
337 {
338         enum debug_obj_state state;
339         struct debug_bucket *db;
340         struct debug_obj *obj;
341         unsigned long flags;
342
343         if (!debug_objects_enabled)
344                 return;
345
346         db = get_bucket((unsigned long) addr);
347
348         spin_lock_irqsave(&db->lock, flags);
349
350         obj = lookup_object(addr, db);
351         if (obj) {
352                 switch (obj->state) {
353                 case ODEBUG_STATE_INIT:
354                 case ODEBUG_STATE_INACTIVE:
355                         obj->state = ODEBUG_STATE_ACTIVE;
356                         break;
357
358                 case ODEBUG_STATE_ACTIVE:
359                         debug_print_object(obj, "activate");
360                         state = obj->state;
361                         spin_unlock_irqrestore(&db->lock, flags);
362                         debug_object_fixup(descr->fixup_activate, addr, state);
363                         return;
364
365                 case ODEBUG_STATE_DESTROYED:
366                         debug_print_object(obj, "activate");
367                         break;
368                 default:
369                         break;
370                 }
371                 spin_unlock_irqrestore(&db->lock, flags);
372                 return;
373         }
374
375         spin_unlock_irqrestore(&db->lock, flags);
376         /*
377          * This happens when a static object is activated. We
378          * let the type specific code decide whether this is
379          * true or not.
380          */
381         debug_object_fixup(descr->fixup_activate, addr,
382                            ODEBUG_STATE_NOTAVAILABLE);
383 }
384
385 /**
386  * debug_object_deactivate - debug checks when an object is deactivated
387  * @addr:       address of the object
388  * @descr:      pointer to an object specific debug description structure
389  */
390 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
391 {
392         struct debug_bucket *db;
393         struct debug_obj *obj;
394         unsigned long flags;
395
396         if (!debug_objects_enabled)
397                 return;
398
399         db = get_bucket((unsigned long) addr);
400
401         spin_lock_irqsave(&db->lock, flags);
402
403         obj = lookup_object(addr, db);
404         if (obj) {
405                 switch (obj->state) {
406                 case ODEBUG_STATE_INIT:
407                 case ODEBUG_STATE_INACTIVE:
408                 case ODEBUG_STATE_ACTIVE:
409                         obj->state = ODEBUG_STATE_INACTIVE;
410                         break;
411
412                 case ODEBUG_STATE_DESTROYED:
413                         debug_print_object(obj, "deactivate");
414                         break;
415                 default:
416                         break;
417                 }
418         } else {
419                 struct debug_obj o = { .object = addr,
420                                        .state = ODEBUG_STATE_NOTAVAILABLE,
421                                        .descr = descr };
422
423                 debug_print_object(&o, "deactivate");
424         }
425
426         spin_unlock_irqrestore(&db->lock, flags);
427 }
428
429 /**
430  * debug_object_destroy - debug checks when an object is destroyed
431  * @addr:       address of the object
432  * @descr:      pointer to an object specific debug description structure
433  */
434 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
435 {
436         enum debug_obj_state state;
437         struct debug_bucket *db;
438         struct debug_obj *obj;
439         unsigned long flags;
440
441         if (!debug_objects_enabled)
442                 return;
443
444         db = get_bucket((unsigned long) addr);
445
446         spin_lock_irqsave(&db->lock, flags);
447
448         obj = lookup_object(addr, db);
449         if (!obj)
450                 goto out_unlock;
451
452         switch (obj->state) {
453         case ODEBUG_STATE_NONE:
454         case ODEBUG_STATE_INIT:
455         case ODEBUG_STATE_INACTIVE:
456                 obj->state = ODEBUG_STATE_DESTROYED;
457                 break;
458         case ODEBUG_STATE_ACTIVE:
459                 debug_print_object(obj, "destroy");
460                 state = obj->state;
461                 spin_unlock_irqrestore(&db->lock, flags);
462                 debug_object_fixup(descr->fixup_destroy, addr, state);
463                 return;
464
465         case ODEBUG_STATE_DESTROYED:
466                 debug_print_object(obj, "destroy");
467                 break;
468         default:
469                 break;
470         }
471 out_unlock:
472         spin_unlock_irqrestore(&db->lock, flags);
473 }
474
475 /**
476  * debug_object_free - debug checks when an object is freed
477  * @addr:       address of the object
478  * @descr:      pointer to an object specific debug description structure
479  */
480 void debug_object_free(void *addr, struct debug_obj_descr *descr)
481 {
482         enum debug_obj_state state;
483         struct debug_bucket *db;
484         struct debug_obj *obj;
485         unsigned long flags;
486
487         if (!debug_objects_enabled)
488                 return;
489
490         db = get_bucket((unsigned long) addr);
491
492         spin_lock_irqsave(&db->lock, flags);
493
494         obj = lookup_object(addr, db);
495         if (!obj)
496                 goto out_unlock;
497
498         switch (obj->state) {
499         case ODEBUG_STATE_ACTIVE:
500                 debug_print_object(obj, "free");
501                 state = obj->state;
502                 spin_unlock_irqrestore(&db->lock, flags);
503                 debug_object_fixup(descr->fixup_free, addr, state);
504                 return;
505         default:
506                 hlist_del(&obj->node);
507                 free_object(obj);
508                 break;
509         }
510 out_unlock:
511         spin_unlock_irqrestore(&db->lock, flags);
512 }
513
514 #ifdef CONFIG_DEBUG_OBJECTS_FREE
515 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
516 {
517         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
518         struct hlist_node *node, *tmp;
519         struct debug_obj_descr *descr;
520         enum debug_obj_state state;
521         struct debug_bucket *db;
522         struct debug_obj *obj;
523         int cnt;
524
525         saddr = (unsigned long) address;
526         eaddr = saddr + size;
527         paddr = saddr & ODEBUG_CHUNK_MASK;
528         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
529         chunks >>= ODEBUG_CHUNK_SHIFT;
530
531         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
532                 db = get_bucket(paddr);
533
534 repeat:
535                 cnt = 0;
536                 spin_lock_irqsave(&db->lock, flags);
537                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
538                         cnt++;
539                         oaddr = (unsigned long) obj->object;
540                         if (oaddr < saddr || oaddr >= eaddr)
541                                 continue;
542
543                         switch (obj->state) {
544                         case ODEBUG_STATE_ACTIVE:
545                                 debug_print_object(obj, "free");
546                                 descr = obj->descr;
547                                 state = obj->state;
548                                 spin_unlock_irqrestore(&db->lock, flags);
549                                 debug_object_fixup(descr->fixup_free,
550                                                    (void *) oaddr, state);
551                                 goto repeat;
552                         default:
553                                 hlist_del(&obj->node);
554                                 free_object(obj);
555                                 break;
556                         }
557                 }
558                 spin_unlock_irqrestore(&db->lock, flags);
559                 if (cnt > debug_objects_maxchain)
560                         debug_objects_maxchain = cnt;
561         }
562 }
563
564 void debug_check_no_obj_freed(const void *address, unsigned long size)
565 {
566         if (debug_objects_enabled)
567                 __debug_check_no_obj_freed(address, size);
568 }
569 #endif
570
571 #ifdef CONFIG_DEBUG_FS
572
573 static int debug_stats_show(struct seq_file *m, void *v)
574 {
575         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
576         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
577         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
578         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
579         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
580         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
581         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
582         return 0;
583 }
584
585 static int debug_stats_open(struct inode *inode, struct file *filp)
586 {
587         return single_open(filp, debug_stats_show, NULL);
588 }
589
590 static const struct file_operations debug_stats_fops = {
591         .open           = debug_stats_open,
592         .read           = seq_read,
593         .llseek         = seq_lseek,
594         .release        = single_release,
595 };
596
597 static int __init debug_objects_init_debugfs(void)
598 {
599         struct dentry *dbgdir, *dbgstats;
600
601         if (!debug_objects_enabled)
602                 return 0;
603
604         dbgdir = debugfs_create_dir("debug_objects", NULL);
605         if (!dbgdir)
606                 return -ENOMEM;
607
608         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
609                                        &debug_stats_fops);
610         if (!dbgstats)
611                 goto err;
612
613         return 0;
614
615 err:
616         debugfs_remove(dbgdir);
617
618         return -ENOMEM;
619 }
620 __initcall(debug_objects_init_debugfs);
621
622 #else
623 static inline void debug_objects_init_debugfs(void) { }
624 #endif
625
626 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
627
628 /* Random data structure for the self test */
629 struct self_test {
630         unsigned long   dummy1[6];
631         int             static_init;
632         unsigned long   dummy2[3];
633 };
634
635 static __initdata struct debug_obj_descr descr_type_test;
636
637 /*
638  * fixup_init is called when:
639  * - an active object is initialized
640  */
641 static int __init fixup_init(void *addr, enum debug_obj_state state)
642 {
643         struct self_test *obj = addr;
644
645         switch (state) {
646         case ODEBUG_STATE_ACTIVE:
647                 debug_object_deactivate(obj, &descr_type_test);
648                 debug_object_init(obj, &descr_type_test);
649                 return 1;
650         default:
651                 return 0;
652         }
653 }
654
655 /*
656  * fixup_activate is called when:
657  * - an active object is activated
658  * - an unknown object is activated (might be a statically initialized object)
659  */
660 static int __init fixup_activate(void *addr, enum debug_obj_state state)
661 {
662         struct self_test *obj = addr;
663
664         switch (state) {
665         case ODEBUG_STATE_NOTAVAILABLE:
666                 if (obj->static_init == 1) {
667                         debug_object_init(obj, &descr_type_test);
668                         debug_object_activate(obj, &descr_type_test);
669                         /*
670                          * Real code should return 0 here ! This is
671                          * not a fixup of some bad behaviour. We
672                          * merily call the debug_init function to keep
673                          * track of the object.
674                          */
675                         return 1;
676                 } else {
677                         /* Real code needs to emit a warning here */
678                 }
679                 return 0;
680
681         case ODEBUG_STATE_ACTIVE:
682                 debug_object_deactivate(obj, &descr_type_test);
683                 debug_object_activate(obj, &descr_type_test);
684                 return 1;
685
686         default:
687                 return 0;
688         }
689 }
690
691 /*
692  * fixup_destroy is called when:
693  * - an active object is destroyed
694  */
695 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
696 {
697         struct self_test *obj = addr;
698
699         switch (state) {
700         case ODEBUG_STATE_ACTIVE:
701                 debug_object_deactivate(obj, &descr_type_test);
702                 debug_object_destroy(obj, &descr_type_test);
703                 return 1;
704         default:
705                 return 0;
706         }
707 }
708
709 /*
710  * fixup_free is called when:
711  * - an active object is freed
712  */
713 static int __init fixup_free(void *addr, enum debug_obj_state state)
714 {
715         struct self_test *obj = addr;
716
717         switch (state) {
718         case ODEBUG_STATE_ACTIVE:
719                 debug_object_deactivate(obj, &descr_type_test);
720                 debug_object_free(obj, &descr_type_test);
721                 return 1;
722         default:
723                 return 0;
724         }
725 }
726
727 static int
728 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
729 {
730         struct debug_bucket *db;
731         struct debug_obj *obj;
732         unsigned long flags;
733         int res = -EINVAL;
734
735         db = get_bucket((unsigned long) addr);
736
737         spin_lock_irqsave(&db->lock, flags);
738
739         obj = lookup_object(addr, db);
740         if (!obj && state != ODEBUG_STATE_NONE) {
741                 printk(KERN_ERR "ODEBUG: selftest object not found\n");
742                 WARN_ON(1);
743                 goto out;
744         }
745         if (obj && obj->state != state) {
746                 printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
747                        obj->state, state);
748                 WARN_ON(1);
749                 goto out;
750         }
751         if (fixups != debug_objects_fixups) {
752                 printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
753                        fixups, debug_objects_fixups);
754                 WARN_ON(1);
755                 goto out;
756         }
757         if (warnings != debug_objects_warnings) {
758                 printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
759                        warnings, debug_objects_warnings);
760                 WARN_ON(1);
761                 goto out;
762         }
763         res = 0;
764 out:
765         spin_unlock_irqrestore(&db->lock, flags);
766         if (res)
767                 debug_objects_enabled = 0;
768         return res;
769 }
770
771 static __initdata struct debug_obj_descr descr_type_test = {
772         .name                   = "selftest",
773         .fixup_init             = fixup_init,
774         .fixup_activate         = fixup_activate,
775         .fixup_destroy          = fixup_destroy,
776         .fixup_free             = fixup_free,
777 };
778
779 static __initdata struct self_test obj = { .static_init = 0 };
780
781 static void __init debug_objects_selftest(void)
782 {
783         int fixups, oldfixups, warnings, oldwarnings;
784         unsigned long flags;
785
786         local_irq_save(flags);
787
788         fixups = oldfixups = debug_objects_fixups;
789         warnings = oldwarnings = debug_objects_warnings;
790         descr_test = &descr_type_test;
791
792         debug_object_init(&obj, &descr_type_test);
793         if (check_results(&obj, ODEBUG_STATE_INIT, 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_activate(&obj, &descr_type_test);
799         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
800                 goto out;
801         debug_object_deactivate(&obj, &descr_type_test);
802         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
803                 goto out;
804         debug_object_destroy(&obj, &descr_type_test);
805         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
806                 goto out;
807         debug_object_init(&obj, &descr_type_test);
808         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
809                 goto out;
810         debug_object_activate(&obj, &descr_type_test);
811         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
812                 goto out;
813         debug_object_deactivate(&obj, &descr_type_test);
814         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
815                 goto out;
816         debug_object_free(&obj, &descr_type_test);
817         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
818                 goto out;
819
820         obj.static_init = 1;
821         debug_object_activate(&obj, &descr_type_test);
822         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
823                 goto out;
824         debug_object_init(&obj, &descr_type_test);
825         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
826                 goto out;
827         debug_object_free(&obj, &descr_type_test);
828         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
829                 goto out;
830
831 #ifdef CONFIG_DEBUG_OBJECTS_FREE
832         debug_object_init(&obj, &descr_type_test);
833         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
834                 goto out;
835         debug_object_activate(&obj, &descr_type_test);
836         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
837                 goto out;
838         __debug_check_no_obj_freed(&obj, sizeof(obj));
839         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
840                 goto out;
841 #endif
842         printk(KERN_INFO "ODEBUG: selftest passed\n");
843
844 out:
845         debug_objects_fixups = oldfixups;
846         debug_objects_warnings = oldwarnings;
847         descr_test = NULL;
848
849         local_irq_restore(flags);
850 }
851 #else
852 static inline void debug_objects_selftest(void) { }
853 #endif
854
855 /*
856  * Called during early boot to initialize the hash buckets and link
857  * the static object pool objects into the poll list. After this call
858  * the object tracker is fully operational.
859  */
860 void __init debug_objects_early_init(void)
861 {
862         int i;
863
864         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
865                 spin_lock_init(&obj_hash[i].lock);
866
867         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
868                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
869 }
870
871 /*
872  * Called after the kmem_caches are functional to setup a dedicated
873  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
874  * prevents that the debug code is called on kmem_cache_free() for the
875  * debug tracker objects to avoid recursive calls.
876  */
877 void __init debug_objects_mem_init(void)
878 {
879         if (!debug_objects_enabled)
880                 return;
881
882         obj_cache = kmem_cache_create("debug_objects_cache",
883                                       sizeof (struct debug_obj), 0,
884                                       SLAB_DEBUG_OBJECTS, NULL);
885
886         if (!obj_cache)
887                 debug_objects_enabled = 0;
888         else
889                 debug_objects_selftest();
890 }