dynamic_debug: factor vpr_info_dq out of ddebug_parse_query
[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/sched.h>
13 #include <linux/seq_file.h>
14 #include <linux/debugfs.h>
15 #include <linux/slab.h>
16 #include <linux/hash.h>
17
18 #define ODEBUG_HASH_BITS        14
19 #define ODEBUG_HASH_SIZE        (1 << ODEBUG_HASH_BITS)
20
21 #define ODEBUG_POOL_SIZE        512
22 #define ODEBUG_POOL_MIN_LEVEL   256
23
24 #define ODEBUG_CHUNK_SHIFT      PAGE_SHIFT
25 #define ODEBUG_CHUNK_SIZE       (1 << ODEBUG_CHUNK_SHIFT)
26 #define ODEBUG_CHUNK_MASK       (~(ODEBUG_CHUNK_SIZE - 1))
27
28 struct debug_bucket {
29         struct hlist_head       list;
30         raw_spinlock_t          lock;
31 };
32
33 static struct debug_bucket      obj_hash[ODEBUG_HASH_SIZE];
34
35 static struct debug_obj         obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
36
37 static DEFINE_RAW_SPINLOCK(pool_lock);
38
39 static HLIST_HEAD(obj_pool);
40
41 static int                      obj_pool_min_free = ODEBUG_POOL_SIZE;
42 static int                      obj_pool_free = ODEBUG_POOL_SIZE;
43 static int                      obj_pool_used;
44 static int                      obj_pool_max_used;
45 static struct kmem_cache        *obj_cache;
46
47 static int                      debug_objects_maxchain __read_mostly;
48 static int                      debug_objects_fixups __read_mostly;
49 static int                      debug_objects_warnings __read_mostly;
50 static int                      debug_objects_enabled __read_mostly
51                                 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
52
53 static struct debug_obj_descr   *descr_test  __read_mostly;
54
55 static void free_obj_work(struct work_struct *work);
56 static DECLARE_WORK(debug_obj_work, free_obj_work);
57
58 static int __init enable_object_debug(char *str)
59 {
60         debug_objects_enabled = 1;
61         return 0;
62 }
63
64 static int __init disable_object_debug(char *str)
65 {
66         debug_objects_enabled = 0;
67         return 0;
68 }
69
70 early_param("debug_objects", enable_object_debug);
71 early_param("no_debug_objects", disable_object_debug);
72
73 static const char *obj_states[ODEBUG_STATE_MAX] = {
74         [ODEBUG_STATE_NONE]             = "none",
75         [ODEBUG_STATE_INIT]             = "initialized",
76         [ODEBUG_STATE_INACTIVE]         = "inactive",
77         [ODEBUG_STATE_ACTIVE]           = "active",
78         [ODEBUG_STATE_DESTROYED]        = "destroyed",
79         [ODEBUG_STATE_NOTAVAILABLE]     = "not available",
80 };
81
82 static int fill_pool(void)
83 {
84         gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
85         struct debug_obj *new;
86         unsigned long flags;
87
88         if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
89                 return obj_pool_free;
90
91         if (unlikely(!obj_cache))
92                 return obj_pool_free;
93
94         while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
95
96                 new = kmem_cache_zalloc(obj_cache, gfp);
97                 if (!new)
98                         return obj_pool_free;
99
100                 raw_spin_lock_irqsave(&pool_lock, flags);
101                 hlist_add_head(&new->node, &obj_pool);
102                 obj_pool_free++;
103                 raw_spin_unlock_irqrestore(&pool_lock, flags);
104         }
105         return obj_pool_free;
106 }
107
108 /*
109  * Lookup an object in the hash bucket.
110  */
111 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
112 {
113         struct hlist_node *node;
114         struct debug_obj *obj;
115         int cnt = 0;
116
117         hlist_for_each_entry(obj, node, &b->list, node) {
118                 cnt++;
119                 if (obj->object == addr)
120                         return obj;
121         }
122         if (cnt > debug_objects_maxchain)
123                 debug_objects_maxchain = cnt;
124
125         return NULL;
126 }
127
128 /*
129  * Allocate a new object. If the pool is empty, switch off the debugger.
130  * Must be called with interrupts disabled.
131  */
132 static struct debug_obj *
133 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
134 {
135         struct debug_obj *obj = NULL;
136
137         raw_spin_lock(&pool_lock);
138         if (obj_pool.first) {
139                 obj         = hlist_entry(obj_pool.first, typeof(*obj), node);
140
141                 obj->object = addr;
142                 obj->descr  = descr;
143                 obj->state  = ODEBUG_STATE_NONE;
144                 obj->astate = 0;
145                 hlist_del(&obj->node);
146
147                 hlist_add_head(&obj->node, &b->list);
148
149                 obj_pool_used++;
150                 if (obj_pool_used > obj_pool_max_used)
151                         obj_pool_max_used = obj_pool_used;
152
153                 obj_pool_free--;
154                 if (obj_pool_free < obj_pool_min_free)
155                         obj_pool_min_free = obj_pool_free;
156         }
157         raw_spin_unlock(&pool_lock);
158
159         return obj;
160 }
161
162 /*
163  * workqueue function to free objects.
164  */
165 static void free_obj_work(struct work_struct *work)
166 {
167         struct debug_obj *obj;
168         unsigned long flags;
169
170         raw_spin_lock_irqsave(&pool_lock, flags);
171         while (obj_pool_free > ODEBUG_POOL_SIZE) {
172                 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
173                 hlist_del(&obj->node);
174                 obj_pool_free--;
175                 /*
176                  * We release pool_lock across kmem_cache_free() to
177                  * avoid contention on pool_lock.
178                  */
179                 raw_spin_unlock_irqrestore(&pool_lock, flags);
180                 kmem_cache_free(obj_cache, obj);
181                 raw_spin_lock_irqsave(&pool_lock, flags);
182         }
183         raw_spin_unlock_irqrestore(&pool_lock, flags);
184 }
185
186 /*
187  * Put the object back into the pool and schedule work to free objects
188  * if necessary.
189  */
190 static void free_object(struct debug_obj *obj)
191 {
192         unsigned long flags;
193         int sched = 0;
194
195         raw_spin_lock_irqsave(&pool_lock, flags);
196         /*
197          * schedule work when the pool is filled and the cache is
198          * initialized:
199          */
200         if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache)
201                 sched = keventd_up() && !work_pending(&debug_obj_work);
202         hlist_add_head(&obj->node, &obj_pool);
203         obj_pool_free++;
204         obj_pool_used--;
205         raw_spin_unlock_irqrestore(&pool_lock, flags);
206         if (sched)
207                 schedule_work(&debug_obj_work);
208 }
209
210 /*
211  * We run out of memory. That means we probably have tons of objects
212  * allocated.
213  */
214 static void debug_objects_oom(void)
215 {
216         struct debug_bucket *db = obj_hash;
217         struct hlist_node *node, *tmp;
218         HLIST_HEAD(freelist);
219         struct debug_obj *obj;
220         unsigned long flags;
221         int i;
222
223         printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
224
225         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
226                 raw_spin_lock_irqsave(&db->lock, flags);
227                 hlist_move_list(&db->list, &freelist);
228                 raw_spin_unlock_irqrestore(&db->lock, flags);
229
230                 /* Now free them */
231                 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
232                         hlist_del(&obj->node);
233                         free_object(obj);
234                 }
235         }
236 }
237
238 /*
239  * We use the pfn of the address for the hash. That way we can check
240  * for freed objects simply by checking the affected bucket.
241  */
242 static struct debug_bucket *get_bucket(unsigned long addr)
243 {
244         unsigned long hash;
245
246         hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
247         return &obj_hash[hash];
248 }
249
250 static void debug_print_object(struct debug_obj *obj, char *msg)
251 {
252         struct debug_obj_descr *descr = obj->descr;
253         static int limit;
254
255         if (limit < 5 && descr != descr_test) {
256                 void *hint = descr->debug_hint ?
257                         descr->debug_hint(obj->object) : NULL;
258                 limit++;
259                 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
260                                  "object type: %s hint: %pS\n",
261                         msg, obj_states[obj->state], obj->astate,
262                         descr->name, hint);
263         }
264         debug_objects_warnings++;
265 }
266
267 /*
268  * Try to repair the damage, so we have a better chance to get useful
269  * debug output.
270  */
271 static int
272 debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
273                    void * addr, enum debug_obj_state state)
274 {
275         int fixed = 0;
276
277         if (fixup)
278                 fixed = fixup(addr, state);
279         debug_objects_fixups += fixed;
280         return fixed;
281 }
282
283 static void debug_object_is_on_stack(void *addr, int onstack)
284 {
285         int is_on_stack;
286         static int limit;
287
288         if (limit > 4)
289                 return;
290
291         is_on_stack = object_is_on_stack(addr);
292         if (is_on_stack == onstack)
293                 return;
294
295         limit++;
296         if (is_on_stack)
297                 printk(KERN_WARNING
298                        "ODEBUG: object is on stack, but not annotated\n");
299         else
300                 printk(KERN_WARNING
301                        "ODEBUG: object is not on stack, but annotated\n");
302         WARN_ON(1);
303 }
304
305 static void
306 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
307 {
308         enum debug_obj_state state;
309         struct debug_bucket *db;
310         struct debug_obj *obj;
311         unsigned long flags;
312
313         fill_pool();
314
315         db = get_bucket((unsigned long) addr);
316
317         raw_spin_lock_irqsave(&db->lock, flags);
318
319         obj = lookup_object(addr, db);
320         if (!obj) {
321                 obj = alloc_object(addr, db, descr);
322                 if (!obj) {
323                         debug_objects_enabled = 0;
324                         raw_spin_unlock_irqrestore(&db->lock, flags);
325                         debug_objects_oom();
326                         return;
327                 }
328                 debug_object_is_on_stack(addr, onstack);
329         }
330
331         switch (obj->state) {
332         case ODEBUG_STATE_NONE:
333         case ODEBUG_STATE_INIT:
334         case ODEBUG_STATE_INACTIVE:
335                 obj->state = ODEBUG_STATE_INIT;
336                 break;
337
338         case ODEBUG_STATE_ACTIVE:
339                 debug_print_object(obj, "init");
340                 state = obj->state;
341                 raw_spin_unlock_irqrestore(&db->lock, flags);
342                 debug_object_fixup(descr->fixup_init, addr, state);
343                 return;
344
345         case ODEBUG_STATE_DESTROYED:
346                 debug_print_object(obj, "init");
347                 break;
348         default:
349                 break;
350         }
351
352         raw_spin_unlock_irqrestore(&db->lock, flags);
353 }
354
355 /**
356  * debug_object_init - debug checks when an object is initialized
357  * @addr:       address of the object
358  * @descr:      pointer to an object specific debug description structure
359  */
360 void debug_object_init(void *addr, struct debug_obj_descr *descr)
361 {
362         if (!debug_objects_enabled)
363                 return;
364
365         __debug_object_init(addr, descr, 0);
366 }
367
368 /**
369  * debug_object_init_on_stack - debug checks when an object on stack is
370  *                              initialized
371  * @addr:       address of the object
372  * @descr:      pointer to an object specific debug description structure
373  */
374 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
375 {
376         if (!debug_objects_enabled)
377                 return;
378
379         __debug_object_init(addr, descr, 1);
380 }
381
382 /**
383  * debug_object_activate - debug checks when an object is activated
384  * @addr:       address of the object
385  * @descr:      pointer to an object specific debug description structure
386  */
387 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
388 {
389         enum debug_obj_state state;
390         struct debug_bucket *db;
391         struct debug_obj *obj;
392         unsigned long flags;
393         struct debug_obj o = { .object = addr,
394                                .state = ODEBUG_STATE_NOTAVAILABLE,
395                                .descr = descr };
396
397         if (!debug_objects_enabled)
398                 return;
399
400         db = get_bucket((unsigned long) addr);
401
402         raw_spin_lock_irqsave(&db->lock, flags);
403
404         obj = lookup_object(addr, db);
405         if (obj) {
406                 switch (obj->state) {
407                 case ODEBUG_STATE_INIT:
408                 case ODEBUG_STATE_INACTIVE:
409                         obj->state = ODEBUG_STATE_ACTIVE;
410                         break;
411
412                 case ODEBUG_STATE_ACTIVE:
413                         debug_print_object(obj, "activate");
414                         state = obj->state;
415                         raw_spin_unlock_irqrestore(&db->lock, flags);
416                         debug_object_fixup(descr->fixup_activate, addr, state);
417                         return;
418
419                 case ODEBUG_STATE_DESTROYED:
420                         debug_print_object(obj, "activate");
421                         break;
422                 default:
423                         break;
424                 }
425                 raw_spin_unlock_irqrestore(&db->lock, flags);
426                 return;
427         }
428
429         raw_spin_unlock_irqrestore(&db->lock, flags);
430         /*
431          * This happens when a static object is activated. We
432          * let the type specific code decide whether this is
433          * true or not.
434          */
435         if (debug_object_fixup(descr->fixup_activate, addr,
436                            ODEBUG_STATE_NOTAVAILABLE))
437                 debug_print_object(&o, "activate");
438 }
439
440 /**
441  * debug_object_deactivate - debug checks when an object is deactivated
442  * @addr:       address of the object
443  * @descr:      pointer to an object specific debug description structure
444  */
445 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
446 {
447         struct debug_bucket *db;
448         struct debug_obj *obj;
449         unsigned long flags;
450
451         if (!debug_objects_enabled)
452                 return;
453
454         db = get_bucket((unsigned long) addr);
455
456         raw_spin_lock_irqsave(&db->lock, flags);
457
458         obj = lookup_object(addr, db);
459         if (obj) {
460                 switch (obj->state) {
461                 case ODEBUG_STATE_INIT:
462                 case ODEBUG_STATE_INACTIVE:
463                 case ODEBUG_STATE_ACTIVE:
464                         if (!obj->astate)
465                                 obj->state = ODEBUG_STATE_INACTIVE;
466                         else
467                                 debug_print_object(obj, "deactivate");
468                         break;
469
470                 case ODEBUG_STATE_DESTROYED:
471                         debug_print_object(obj, "deactivate");
472                         break;
473                 default:
474                         break;
475                 }
476         } else {
477                 struct debug_obj o = { .object = addr,
478                                        .state = ODEBUG_STATE_NOTAVAILABLE,
479                                        .descr = descr };
480
481                 debug_print_object(&o, "deactivate");
482         }
483
484         raw_spin_unlock_irqrestore(&db->lock, flags);
485 }
486
487 /**
488  * debug_object_destroy - debug checks when an object is destroyed
489  * @addr:       address of the object
490  * @descr:      pointer to an object specific debug description structure
491  */
492 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
493 {
494         enum debug_obj_state state;
495         struct debug_bucket *db;
496         struct debug_obj *obj;
497         unsigned long flags;
498
499         if (!debug_objects_enabled)
500                 return;
501
502         db = get_bucket((unsigned long) addr);
503
504         raw_spin_lock_irqsave(&db->lock, flags);
505
506         obj = lookup_object(addr, db);
507         if (!obj)
508                 goto out_unlock;
509
510         switch (obj->state) {
511         case ODEBUG_STATE_NONE:
512         case ODEBUG_STATE_INIT:
513         case ODEBUG_STATE_INACTIVE:
514                 obj->state = ODEBUG_STATE_DESTROYED;
515                 break;
516         case ODEBUG_STATE_ACTIVE:
517                 debug_print_object(obj, "destroy");
518                 state = obj->state;
519                 raw_spin_unlock_irqrestore(&db->lock, flags);
520                 debug_object_fixup(descr->fixup_destroy, addr, state);
521                 return;
522
523         case ODEBUG_STATE_DESTROYED:
524                 debug_print_object(obj, "destroy");
525                 break;
526         default:
527                 break;
528         }
529 out_unlock:
530         raw_spin_unlock_irqrestore(&db->lock, flags);
531 }
532
533 /**
534  * debug_object_free - debug checks when an object is freed
535  * @addr:       address of the object
536  * @descr:      pointer to an object specific debug description structure
537  */
538 void debug_object_free(void *addr, struct debug_obj_descr *descr)
539 {
540         enum debug_obj_state state;
541         struct debug_bucket *db;
542         struct debug_obj *obj;
543         unsigned long flags;
544
545         if (!debug_objects_enabled)
546                 return;
547
548         db = get_bucket((unsigned long) addr);
549
550         raw_spin_lock_irqsave(&db->lock, flags);
551
552         obj = lookup_object(addr, db);
553         if (!obj)
554                 goto out_unlock;
555
556         switch (obj->state) {
557         case ODEBUG_STATE_ACTIVE:
558                 debug_print_object(obj, "free");
559                 state = obj->state;
560                 raw_spin_unlock_irqrestore(&db->lock, flags);
561                 debug_object_fixup(descr->fixup_free, addr, state);
562                 return;
563         default:
564                 hlist_del(&obj->node);
565                 raw_spin_unlock_irqrestore(&db->lock, flags);
566                 free_object(obj);
567                 return;
568         }
569 out_unlock:
570         raw_spin_unlock_irqrestore(&db->lock, flags);
571 }
572
573 /**
574  * debug_object_assert_init - debug checks when object should be init-ed
575  * @addr:       address of the object
576  * @descr:      pointer to an object specific debug description structure
577  */
578 void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
579 {
580         struct debug_bucket *db;
581         struct debug_obj *obj;
582         unsigned long flags;
583
584         if (!debug_objects_enabled)
585                 return;
586
587         db = get_bucket((unsigned long) addr);
588
589         raw_spin_lock_irqsave(&db->lock, flags);
590
591         obj = lookup_object(addr, db);
592         if (!obj) {
593                 struct debug_obj o = { .object = addr,
594                                        .state = ODEBUG_STATE_NOTAVAILABLE,
595                                        .descr = descr };
596
597                 raw_spin_unlock_irqrestore(&db->lock, flags);
598                 /*
599                  * Maybe the object is static.  Let the type specific
600                  * code decide what to do.
601                  */
602                 if (debug_object_fixup(descr->fixup_assert_init, addr,
603                                        ODEBUG_STATE_NOTAVAILABLE))
604                         debug_print_object(&o, "assert_init");
605                 return;
606         }
607
608         raw_spin_unlock_irqrestore(&db->lock, flags);
609 }
610
611 /**
612  * debug_object_active_state - debug checks object usage state machine
613  * @addr:       address of the object
614  * @descr:      pointer to an object specific debug description structure
615  * @expect:     expected state
616  * @next:       state to move to if expected state is found
617  */
618 void
619 debug_object_active_state(void *addr, struct debug_obj_descr *descr,
620                           unsigned int expect, unsigned int next)
621 {
622         struct debug_bucket *db;
623         struct debug_obj *obj;
624         unsigned long flags;
625
626         if (!debug_objects_enabled)
627                 return;
628
629         db = get_bucket((unsigned long) addr);
630
631         raw_spin_lock_irqsave(&db->lock, flags);
632
633         obj = lookup_object(addr, db);
634         if (obj) {
635                 switch (obj->state) {
636                 case ODEBUG_STATE_ACTIVE:
637                         if (obj->astate == expect)
638                                 obj->astate = next;
639                         else
640                                 debug_print_object(obj, "active_state");
641                         break;
642
643                 default:
644                         debug_print_object(obj, "active_state");
645                         break;
646                 }
647         } else {
648                 struct debug_obj o = { .object = addr,
649                                        .state = ODEBUG_STATE_NOTAVAILABLE,
650                                        .descr = descr };
651
652                 debug_print_object(&o, "active_state");
653         }
654
655         raw_spin_unlock_irqrestore(&db->lock, flags);
656 }
657
658 #ifdef CONFIG_DEBUG_OBJECTS_FREE
659 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
660 {
661         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
662         struct hlist_node *node, *tmp;
663         HLIST_HEAD(freelist);
664         struct debug_obj_descr *descr;
665         enum debug_obj_state state;
666         struct debug_bucket *db;
667         struct debug_obj *obj;
668         int cnt;
669
670         saddr = (unsigned long) address;
671         eaddr = saddr + size;
672         paddr = saddr & ODEBUG_CHUNK_MASK;
673         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
674         chunks >>= ODEBUG_CHUNK_SHIFT;
675
676         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
677                 db = get_bucket(paddr);
678
679 repeat:
680                 cnt = 0;
681                 raw_spin_lock_irqsave(&db->lock, flags);
682                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
683                         cnt++;
684                         oaddr = (unsigned long) obj->object;
685                         if (oaddr < saddr || oaddr >= eaddr)
686                                 continue;
687
688                         switch (obj->state) {
689                         case ODEBUG_STATE_ACTIVE:
690                                 debug_print_object(obj, "free");
691                                 descr = obj->descr;
692                                 state = obj->state;
693                                 raw_spin_unlock_irqrestore(&db->lock, flags);
694                                 debug_object_fixup(descr->fixup_free,
695                                                    (void *) oaddr, state);
696                                 goto repeat;
697                         default:
698                                 hlist_del(&obj->node);
699                                 hlist_add_head(&obj->node, &freelist);
700                                 break;
701                         }
702                 }
703                 raw_spin_unlock_irqrestore(&db->lock, flags);
704
705                 /* Now free them */
706                 hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
707                         hlist_del(&obj->node);
708                         free_object(obj);
709                 }
710
711                 if (cnt > debug_objects_maxchain)
712                         debug_objects_maxchain = cnt;
713         }
714 }
715
716 void debug_check_no_obj_freed(const void *address, unsigned long size)
717 {
718         if (debug_objects_enabled)
719                 __debug_check_no_obj_freed(address, size);
720 }
721 #endif
722
723 #ifdef CONFIG_DEBUG_FS
724
725 static int debug_stats_show(struct seq_file *m, void *v)
726 {
727         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
728         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
729         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
730         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
731         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
732         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
733         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
734         return 0;
735 }
736
737 static int debug_stats_open(struct inode *inode, struct file *filp)
738 {
739         return single_open(filp, debug_stats_show, NULL);
740 }
741
742 static const struct file_operations debug_stats_fops = {
743         .open           = debug_stats_open,
744         .read           = seq_read,
745         .llseek         = seq_lseek,
746         .release        = single_release,
747 };
748
749 static int __init debug_objects_init_debugfs(void)
750 {
751         struct dentry *dbgdir, *dbgstats;
752
753         if (!debug_objects_enabled)
754                 return 0;
755
756         dbgdir = debugfs_create_dir("debug_objects", NULL);
757         if (!dbgdir)
758                 return -ENOMEM;
759
760         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
761                                        &debug_stats_fops);
762         if (!dbgstats)
763                 goto err;
764
765         return 0;
766
767 err:
768         debugfs_remove(dbgdir);
769
770         return -ENOMEM;
771 }
772 __initcall(debug_objects_init_debugfs);
773
774 #else
775 static inline void debug_objects_init_debugfs(void) { }
776 #endif
777
778 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
779
780 /* Random data structure for the self test */
781 struct self_test {
782         unsigned long   dummy1[6];
783         int             static_init;
784         unsigned long   dummy2[3];
785 };
786
787 static __initdata struct debug_obj_descr descr_type_test;
788
789 /*
790  * fixup_init is called when:
791  * - an active object is initialized
792  */
793 static int __init fixup_init(void *addr, enum debug_obj_state state)
794 {
795         struct self_test *obj = addr;
796
797         switch (state) {
798         case ODEBUG_STATE_ACTIVE:
799                 debug_object_deactivate(obj, &descr_type_test);
800                 debug_object_init(obj, &descr_type_test);
801                 return 1;
802         default:
803                 return 0;
804         }
805 }
806
807 /*
808  * fixup_activate is called when:
809  * - an active object is activated
810  * - an unknown object is activated (might be a statically initialized object)
811  */
812 static int __init fixup_activate(void *addr, enum debug_obj_state state)
813 {
814         struct self_test *obj = addr;
815
816         switch (state) {
817         case ODEBUG_STATE_NOTAVAILABLE:
818                 if (obj->static_init == 1) {
819                         debug_object_init(obj, &descr_type_test);
820                         debug_object_activate(obj, &descr_type_test);
821                         /*
822                          * Real code should return 0 here ! This is
823                          * not a fixup of some bad behaviour. We
824                          * merily call the debug_init function to keep
825                          * track of the object.
826                          */
827                         return 1;
828                 } else {
829                         /* Real code needs to emit a warning here */
830                 }
831                 return 0;
832
833         case ODEBUG_STATE_ACTIVE:
834                 debug_object_deactivate(obj, &descr_type_test);
835                 debug_object_activate(obj, &descr_type_test);
836                 return 1;
837
838         default:
839                 return 0;
840         }
841 }
842
843 /*
844  * fixup_destroy is called when:
845  * - an active object is destroyed
846  */
847 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
848 {
849         struct self_test *obj = addr;
850
851         switch (state) {
852         case ODEBUG_STATE_ACTIVE:
853                 debug_object_deactivate(obj, &descr_type_test);
854                 debug_object_destroy(obj, &descr_type_test);
855                 return 1;
856         default:
857                 return 0;
858         }
859 }
860
861 /*
862  * fixup_free is called when:
863  * - an active object is freed
864  */
865 static int __init fixup_free(void *addr, enum debug_obj_state state)
866 {
867         struct self_test *obj = addr;
868
869         switch (state) {
870         case ODEBUG_STATE_ACTIVE:
871                 debug_object_deactivate(obj, &descr_type_test);
872                 debug_object_free(obj, &descr_type_test);
873                 return 1;
874         default:
875                 return 0;
876         }
877 }
878
879 static int __init
880 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
881 {
882         struct debug_bucket *db;
883         struct debug_obj *obj;
884         unsigned long flags;
885         int res = -EINVAL;
886
887         db = get_bucket((unsigned long) addr);
888
889         raw_spin_lock_irqsave(&db->lock, flags);
890
891         obj = lookup_object(addr, db);
892         if (!obj && state != ODEBUG_STATE_NONE) {
893                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
894                 goto out;
895         }
896         if (obj && obj->state != state) {
897                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
898                        obj->state, state);
899                 goto out;
900         }
901         if (fixups != debug_objects_fixups) {
902                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
903                        fixups, debug_objects_fixups);
904                 goto out;
905         }
906         if (warnings != debug_objects_warnings) {
907                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
908                        warnings, debug_objects_warnings);
909                 goto out;
910         }
911         res = 0;
912 out:
913         raw_spin_unlock_irqrestore(&db->lock, flags);
914         if (res)
915                 debug_objects_enabled = 0;
916         return res;
917 }
918
919 static __initdata struct debug_obj_descr descr_type_test = {
920         .name                   = "selftest",
921         .fixup_init             = fixup_init,
922         .fixup_activate         = fixup_activate,
923         .fixup_destroy          = fixup_destroy,
924         .fixup_free             = fixup_free,
925 };
926
927 static __initdata struct self_test obj = { .static_init = 0 };
928
929 static void __init debug_objects_selftest(void)
930 {
931         int fixups, oldfixups, warnings, oldwarnings;
932         unsigned long flags;
933
934         local_irq_save(flags);
935
936         fixups = oldfixups = debug_objects_fixups;
937         warnings = oldwarnings = debug_objects_warnings;
938         descr_test = &descr_type_test;
939
940         debug_object_init(&obj, &descr_type_test);
941         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
942                 goto out;
943         debug_object_activate(&obj, &descr_type_test);
944         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
945                 goto out;
946         debug_object_activate(&obj, &descr_type_test);
947         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
948                 goto out;
949         debug_object_deactivate(&obj, &descr_type_test);
950         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
951                 goto out;
952         debug_object_destroy(&obj, &descr_type_test);
953         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
954                 goto out;
955         debug_object_init(&obj, &descr_type_test);
956         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
957                 goto out;
958         debug_object_activate(&obj, &descr_type_test);
959         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
960                 goto out;
961         debug_object_deactivate(&obj, &descr_type_test);
962         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
963                 goto out;
964         debug_object_free(&obj, &descr_type_test);
965         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
966                 goto out;
967
968         obj.static_init = 1;
969         debug_object_activate(&obj, &descr_type_test);
970         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
971                 goto out;
972         debug_object_init(&obj, &descr_type_test);
973         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
974                 goto out;
975         debug_object_free(&obj, &descr_type_test);
976         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
977                 goto out;
978
979 #ifdef CONFIG_DEBUG_OBJECTS_FREE
980         debug_object_init(&obj, &descr_type_test);
981         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
982                 goto out;
983         debug_object_activate(&obj, &descr_type_test);
984         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
985                 goto out;
986         __debug_check_no_obj_freed(&obj, sizeof(obj));
987         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
988                 goto out;
989 #endif
990         printk(KERN_INFO "ODEBUG: selftest passed\n");
991
992 out:
993         debug_objects_fixups = oldfixups;
994         debug_objects_warnings = oldwarnings;
995         descr_test = NULL;
996
997         local_irq_restore(flags);
998 }
999 #else
1000 static inline void debug_objects_selftest(void) { }
1001 #endif
1002
1003 /*
1004  * Called during early boot to initialize the hash buckets and link
1005  * the static object pool objects into the poll list. After this call
1006  * the object tracker is fully operational.
1007  */
1008 void __init debug_objects_early_init(void)
1009 {
1010         int i;
1011
1012         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1013                 raw_spin_lock_init(&obj_hash[i].lock);
1014
1015         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1016                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1017 }
1018
1019 /*
1020  * Convert the statically allocated objects to dynamic ones:
1021  */
1022 static int __init debug_objects_replace_static_objects(void)
1023 {
1024         struct debug_bucket *db = obj_hash;
1025         struct hlist_node *node, *tmp;
1026         struct debug_obj *obj, *new;
1027         HLIST_HEAD(objects);
1028         int i, cnt = 0;
1029
1030         for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1031                 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1032                 if (!obj)
1033                         goto free;
1034                 hlist_add_head(&obj->node, &objects);
1035         }
1036
1037         /*
1038          * When debug_objects_mem_init() is called we know that only
1039          * one CPU is up, so disabling interrupts is enough
1040          * protection. This avoids the lockdep hell of lock ordering.
1041          */
1042         local_irq_disable();
1043
1044         /* Remove the statically allocated objects from the pool */
1045         hlist_for_each_entry_safe(obj, node, tmp, &obj_pool, node)
1046                 hlist_del(&obj->node);
1047         /* Move the allocated objects to the pool */
1048         hlist_move_list(&objects, &obj_pool);
1049
1050         /* Replace the active object references */
1051         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1052                 hlist_move_list(&db->list, &objects);
1053
1054                 hlist_for_each_entry(obj, node, &objects, node) {
1055                         new = hlist_entry(obj_pool.first, typeof(*obj), node);
1056                         hlist_del(&new->node);
1057                         /* copy object data */
1058                         *new = *obj;
1059                         hlist_add_head(&new->node, &db->list);
1060                         cnt++;
1061                 }
1062         }
1063
1064         printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt,
1065                obj_pool_used);
1066         local_irq_enable();
1067         return 0;
1068 free:
1069         hlist_for_each_entry_safe(obj, node, tmp, &objects, node) {
1070                 hlist_del(&obj->node);
1071                 kmem_cache_free(obj_cache, obj);
1072         }
1073         return -ENOMEM;
1074 }
1075
1076 /*
1077  * Called after the kmem_caches are functional to setup a dedicated
1078  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1079  * prevents that the debug code is called on kmem_cache_free() for the
1080  * debug tracker objects to avoid recursive calls.
1081  */
1082 void __init debug_objects_mem_init(void)
1083 {
1084         if (!debug_objects_enabled)
1085                 return;
1086
1087         obj_cache = kmem_cache_create("debug_objects_cache",
1088                                       sizeof (struct debug_obj), 0,
1089                                       SLAB_DEBUG_OBJECTS, NULL);
1090
1091         if (!obj_cache || debug_objects_replace_static_objects()) {
1092                 debug_objects_enabled = 0;
1093                 if (obj_cache)
1094                         kmem_cache_destroy(obj_cache);
1095                 printk(KERN_WARNING "ODEBUG: out of memory.\n");
1096         } else
1097                 debug_objects_selftest();
1098 }