Merge branch 'for-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...
[linux.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
11 #define pr_fmt(fmt) "ODEBUG: " fmt
12
13 #include <linux/debugobjects.h>
14 #include <linux/interrupt.h>
15 #include <linux/sched.h>
16 #include <linux/sched/task_stack.h>
17 #include <linux/seq_file.h>
18 #include <linux/debugfs.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/kmemleak.h>
22
23 #define ODEBUG_HASH_BITS        14
24 #define ODEBUG_HASH_SIZE        (1 << ODEBUG_HASH_BITS)
25
26 #define ODEBUG_POOL_SIZE        1024
27 #define ODEBUG_POOL_MIN_LEVEL   256
28
29 #define ODEBUG_CHUNK_SHIFT      PAGE_SHIFT
30 #define ODEBUG_CHUNK_SIZE       (1 << ODEBUG_CHUNK_SHIFT)
31 #define ODEBUG_CHUNK_MASK       (~(ODEBUG_CHUNK_SIZE - 1))
32
33 struct debug_bucket {
34         struct hlist_head       list;
35         raw_spinlock_t          lock;
36 };
37
38 static struct debug_bucket      obj_hash[ODEBUG_HASH_SIZE];
39
40 static struct debug_obj         obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
41
42 static DEFINE_RAW_SPINLOCK(pool_lock);
43
44 static HLIST_HEAD(obj_pool);
45
46 static int                      obj_pool_min_free = ODEBUG_POOL_SIZE;
47 static int                      obj_pool_free = ODEBUG_POOL_SIZE;
48 static int                      obj_pool_used;
49 static int                      obj_pool_max_used;
50 static struct kmem_cache        *obj_cache;
51
52 static int                      debug_objects_maxchain __read_mostly;
53 static int                      debug_objects_fixups __read_mostly;
54 static int                      debug_objects_warnings __read_mostly;
55 static int                      debug_objects_enabled __read_mostly
56                                 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
57 static int                      debug_objects_pool_size __read_mostly
58                                 = ODEBUG_POOL_SIZE;
59 static int                      debug_objects_pool_min_level __read_mostly
60                                 = ODEBUG_POOL_MIN_LEVEL;
61 static struct debug_obj_descr   *descr_test  __read_mostly;
62
63 /*
64  * Track numbers of kmem_cache_alloc()/free() calls done.
65  */
66 static int                      debug_objects_allocated;
67 static int                      debug_objects_freed;
68
69 static void free_obj_work(struct work_struct *work);
70 static DECLARE_WORK(debug_obj_work, free_obj_work);
71
72 static int __init enable_object_debug(char *str)
73 {
74         debug_objects_enabled = 1;
75         return 0;
76 }
77
78 static int __init disable_object_debug(char *str)
79 {
80         debug_objects_enabled = 0;
81         return 0;
82 }
83
84 early_param("debug_objects", enable_object_debug);
85 early_param("no_debug_objects", disable_object_debug);
86
87 static const char *obj_states[ODEBUG_STATE_MAX] = {
88         [ODEBUG_STATE_NONE]             = "none",
89         [ODEBUG_STATE_INIT]             = "initialized",
90         [ODEBUG_STATE_INACTIVE]         = "inactive",
91         [ODEBUG_STATE_ACTIVE]           = "active",
92         [ODEBUG_STATE_DESTROYED]        = "destroyed",
93         [ODEBUG_STATE_NOTAVAILABLE]     = "not available",
94 };
95
96 static void fill_pool(void)
97 {
98         gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
99         struct debug_obj *new;
100         unsigned long flags;
101
102         if (likely(obj_pool_free >= debug_objects_pool_min_level))
103                 return;
104
105         if (unlikely(!obj_cache))
106                 return;
107
108         while (obj_pool_free < debug_objects_pool_min_level) {
109
110                 new = kmem_cache_zalloc(obj_cache, gfp);
111                 if (!new)
112                         return;
113
114                 kmemleak_ignore(new);
115                 raw_spin_lock_irqsave(&pool_lock, flags);
116                 hlist_add_head(&new->node, &obj_pool);
117                 debug_objects_allocated++;
118                 obj_pool_free++;
119                 raw_spin_unlock_irqrestore(&pool_lock, flags);
120         }
121 }
122
123 /*
124  * Lookup an object in the hash bucket.
125  */
126 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
127 {
128         struct debug_obj *obj;
129         int cnt = 0;
130
131         hlist_for_each_entry(obj, &b->list, node) {
132                 cnt++;
133                 if (obj->object == addr)
134                         return obj;
135         }
136         if (cnt > debug_objects_maxchain)
137                 debug_objects_maxchain = cnt;
138
139         return NULL;
140 }
141
142 /*
143  * Allocate a new object. If the pool is empty, switch off the debugger.
144  * Must be called with interrupts disabled.
145  */
146 static struct debug_obj *
147 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
148 {
149         struct debug_obj *obj = NULL;
150
151         raw_spin_lock(&pool_lock);
152         if (obj_pool.first) {
153                 obj         = hlist_entry(obj_pool.first, typeof(*obj), node);
154
155                 obj->object = addr;
156                 obj->descr  = descr;
157                 obj->state  = ODEBUG_STATE_NONE;
158                 obj->astate = 0;
159                 hlist_del(&obj->node);
160
161                 hlist_add_head(&obj->node, &b->list);
162
163                 obj_pool_used++;
164                 if (obj_pool_used > obj_pool_max_used)
165                         obj_pool_max_used = obj_pool_used;
166
167                 obj_pool_free--;
168                 if (obj_pool_free < obj_pool_min_free)
169                         obj_pool_min_free = obj_pool_free;
170         }
171         raw_spin_unlock(&pool_lock);
172
173         return obj;
174 }
175
176 /*
177  * workqueue function to free objects.
178  *
179  * To reduce contention on the global pool_lock, the actual freeing of
180  * debug objects will be delayed if the pool_lock is busy. We also free
181  * the objects in a batch of 4 for each lock/unlock cycle.
182  */
183 #define ODEBUG_FREE_BATCH       4
184
185 static void free_obj_work(struct work_struct *work)
186 {
187         struct debug_obj *objs[ODEBUG_FREE_BATCH];
188         unsigned long flags;
189         int i;
190
191         if (!raw_spin_trylock_irqsave(&pool_lock, flags))
192                 return;
193         while (obj_pool_free >= debug_objects_pool_size + ODEBUG_FREE_BATCH) {
194                 for (i = 0; i < ODEBUG_FREE_BATCH; i++) {
195                         objs[i] = hlist_entry(obj_pool.first,
196                                               typeof(*objs[0]), node);
197                         hlist_del(&objs[i]->node);
198                 }
199
200                 obj_pool_free -= ODEBUG_FREE_BATCH;
201                 debug_objects_freed += ODEBUG_FREE_BATCH;
202                 /*
203                  * We release pool_lock across kmem_cache_free() to
204                  * avoid contention on pool_lock.
205                  */
206                 raw_spin_unlock_irqrestore(&pool_lock, flags);
207                 for (i = 0; i < ODEBUG_FREE_BATCH; i++)
208                         kmem_cache_free(obj_cache, objs[i]);
209                 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
210                         return;
211         }
212         raw_spin_unlock_irqrestore(&pool_lock, flags);
213 }
214
215 /*
216  * Put the object back into the pool and schedule work to free objects
217  * if necessary.
218  */
219 static void free_object(struct debug_obj *obj)
220 {
221         unsigned long flags;
222         int sched = 0;
223
224         raw_spin_lock_irqsave(&pool_lock, flags);
225         /*
226          * schedule work when the pool is filled and the cache is
227          * initialized:
228          */
229         if (obj_pool_free > debug_objects_pool_size && obj_cache)
230                 sched = 1;
231         hlist_add_head(&obj->node, &obj_pool);
232         obj_pool_free++;
233         obj_pool_used--;
234         raw_spin_unlock_irqrestore(&pool_lock, flags);
235         if (sched)
236                 schedule_work(&debug_obj_work);
237 }
238
239 /*
240  * We run out of memory. That means we probably have tons of objects
241  * allocated.
242  */
243 static void debug_objects_oom(void)
244 {
245         struct debug_bucket *db = obj_hash;
246         struct hlist_node *tmp;
247         HLIST_HEAD(freelist);
248         struct debug_obj *obj;
249         unsigned long flags;
250         int i;
251
252         pr_warn("Out of memory. ODEBUG disabled\n");
253
254         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
255                 raw_spin_lock_irqsave(&db->lock, flags);
256                 hlist_move_list(&db->list, &freelist);
257                 raw_spin_unlock_irqrestore(&db->lock, flags);
258
259                 /* Now free them */
260                 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
261                         hlist_del(&obj->node);
262                         free_object(obj);
263                 }
264         }
265 }
266
267 /*
268  * We use the pfn of the address for the hash. That way we can check
269  * for freed objects simply by checking the affected bucket.
270  */
271 static struct debug_bucket *get_bucket(unsigned long addr)
272 {
273         unsigned long hash;
274
275         hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
276         return &obj_hash[hash];
277 }
278
279 static void debug_print_object(struct debug_obj *obj, char *msg)
280 {
281         struct debug_obj_descr *descr = obj->descr;
282         static int limit;
283
284         if (limit < 5 && descr != descr_test) {
285                 void *hint = descr->debug_hint ?
286                         descr->debug_hint(obj->object) : NULL;
287                 limit++;
288                 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
289                                  "object type: %s hint: %pS\n",
290                         msg, obj_states[obj->state], obj->astate,
291                         descr->name, hint);
292         }
293         debug_objects_warnings++;
294 }
295
296 /*
297  * Try to repair the damage, so we have a better chance to get useful
298  * debug output.
299  */
300 static bool
301 debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
302                    void * addr, enum debug_obj_state state)
303 {
304         if (fixup && fixup(addr, state)) {
305                 debug_objects_fixups++;
306                 return true;
307         }
308         return false;
309 }
310
311 static void debug_object_is_on_stack(void *addr, int onstack)
312 {
313         int is_on_stack;
314         static int limit;
315
316         if (limit > 4)
317                 return;
318
319         is_on_stack = object_is_on_stack(addr);
320         if (is_on_stack == onstack)
321                 return;
322
323         limit++;
324         if (is_on_stack)
325                 pr_warn("object is on stack, but not annotated\n");
326         else
327                 pr_warn("object is not on stack, but annotated\n");
328         WARN_ON(1);
329 }
330
331 static void
332 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
333 {
334         enum debug_obj_state state;
335         struct debug_bucket *db;
336         struct debug_obj *obj;
337         unsigned long flags;
338
339         fill_pool();
340
341         db = get_bucket((unsigned long) addr);
342
343         raw_spin_lock_irqsave(&db->lock, flags);
344
345         obj = lookup_object(addr, db);
346         if (!obj) {
347                 obj = alloc_object(addr, db, descr);
348                 if (!obj) {
349                         debug_objects_enabled = 0;
350                         raw_spin_unlock_irqrestore(&db->lock, flags);
351                         debug_objects_oom();
352                         return;
353                 }
354                 debug_object_is_on_stack(addr, onstack);
355         }
356
357         switch (obj->state) {
358         case ODEBUG_STATE_NONE:
359         case ODEBUG_STATE_INIT:
360         case ODEBUG_STATE_INACTIVE:
361                 obj->state = ODEBUG_STATE_INIT;
362                 break;
363
364         case ODEBUG_STATE_ACTIVE:
365                 debug_print_object(obj, "init");
366                 state = obj->state;
367                 raw_spin_unlock_irqrestore(&db->lock, flags);
368                 debug_object_fixup(descr->fixup_init, addr, state);
369                 return;
370
371         case ODEBUG_STATE_DESTROYED:
372                 debug_print_object(obj, "init");
373                 break;
374         default:
375                 break;
376         }
377
378         raw_spin_unlock_irqrestore(&db->lock, flags);
379 }
380
381 /**
382  * debug_object_init - debug checks when an object is initialized
383  * @addr:       address of the object
384  * @descr:      pointer to an object specific debug description structure
385  */
386 void debug_object_init(void *addr, struct debug_obj_descr *descr)
387 {
388         if (!debug_objects_enabled)
389                 return;
390
391         __debug_object_init(addr, descr, 0);
392 }
393 EXPORT_SYMBOL_GPL(debug_object_init);
394
395 /**
396  * debug_object_init_on_stack - debug checks when an object on stack is
397  *                              initialized
398  * @addr:       address of the object
399  * @descr:      pointer to an object specific debug description structure
400  */
401 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
402 {
403         if (!debug_objects_enabled)
404                 return;
405
406         __debug_object_init(addr, descr, 1);
407 }
408 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
409
410 /**
411  * debug_object_activate - debug checks when an object is activated
412  * @addr:       address of the object
413  * @descr:      pointer to an object specific debug description structure
414  * Returns 0 for success, -EINVAL for check failed.
415  */
416 int debug_object_activate(void *addr, struct debug_obj_descr *descr)
417 {
418         enum debug_obj_state state;
419         struct debug_bucket *db;
420         struct debug_obj *obj;
421         unsigned long flags;
422         int ret;
423         struct debug_obj o = { .object = addr,
424                                .state = ODEBUG_STATE_NOTAVAILABLE,
425                                .descr = descr };
426
427         if (!debug_objects_enabled)
428                 return 0;
429
430         db = get_bucket((unsigned long) addr);
431
432         raw_spin_lock_irqsave(&db->lock, flags);
433
434         obj = lookup_object(addr, db);
435         if (obj) {
436                 switch (obj->state) {
437                 case ODEBUG_STATE_INIT:
438                 case ODEBUG_STATE_INACTIVE:
439                         obj->state = ODEBUG_STATE_ACTIVE;
440                         ret = 0;
441                         break;
442
443                 case ODEBUG_STATE_ACTIVE:
444                         debug_print_object(obj, "activate");
445                         state = obj->state;
446                         raw_spin_unlock_irqrestore(&db->lock, flags);
447                         ret = debug_object_fixup(descr->fixup_activate, addr, state);
448                         return ret ? 0 : -EINVAL;
449
450                 case ODEBUG_STATE_DESTROYED:
451                         debug_print_object(obj, "activate");
452                         ret = -EINVAL;
453                         break;
454                 default:
455                         ret = 0;
456                         break;
457                 }
458                 raw_spin_unlock_irqrestore(&db->lock, flags);
459                 return ret;
460         }
461
462         raw_spin_unlock_irqrestore(&db->lock, flags);
463         /*
464          * We are here when a static object is activated. We
465          * let the type specific code confirm whether this is
466          * true or not. if true, we just make sure that the
467          * static object is tracked in the object tracker. If
468          * not, this must be a bug, so we try to fix it up.
469          */
470         if (descr->is_static_object && descr->is_static_object(addr)) {
471                 /* track this static object */
472                 debug_object_init(addr, descr);
473                 debug_object_activate(addr, descr);
474         } else {
475                 debug_print_object(&o, "activate");
476                 ret = debug_object_fixup(descr->fixup_activate, addr,
477                                         ODEBUG_STATE_NOTAVAILABLE);
478                 return ret ? 0 : -EINVAL;
479         }
480         return 0;
481 }
482 EXPORT_SYMBOL_GPL(debug_object_activate);
483
484 /**
485  * debug_object_deactivate - debug checks when an object is deactivated
486  * @addr:       address of the object
487  * @descr:      pointer to an object specific debug description structure
488  */
489 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
490 {
491         struct debug_bucket *db;
492         struct debug_obj *obj;
493         unsigned long flags;
494
495         if (!debug_objects_enabled)
496                 return;
497
498         db = get_bucket((unsigned long) addr);
499
500         raw_spin_lock_irqsave(&db->lock, flags);
501
502         obj = lookup_object(addr, db);
503         if (obj) {
504                 switch (obj->state) {
505                 case ODEBUG_STATE_INIT:
506                 case ODEBUG_STATE_INACTIVE:
507                 case ODEBUG_STATE_ACTIVE:
508                         if (!obj->astate)
509                                 obj->state = ODEBUG_STATE_INACTIVE;
510                         else
511                                 debug_print_object(obj, "deactivate");
512                         break;
513
514                 case ODEBUG_STATE_DESTROYED:
515                         debug_print_object(obj, "deactivate");
516                         break;
517                 default:
518                         break;
519                 }
520         } else {
521                 struct debug_obj o = { .object = addr,
522                                        .state = ODEBUG_STATE_NOTAVAILABLE,
523                                        .descr = descr };
524
525                 debug_print_object(&o, "deactivate");
526         }
527
528         raw_spin_unlock_irqrestore(&db->lock, flags);
529 }
530 EXPORT_SYMBOL_GPL(debug_object_deactivate);
531
532 /**
533  * debug_object_destroy - debug checks when an object is destroyed
534  * @addr:       address of the object
535  * @descr:      pointer to an object specific debug description structure
536  */
537 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
538 {
539         enum debug_obj_state state;
540         struct debug_bucket *db;
541         struct debug_obj *obj;
542         unsigned long flags;
543
544         if (!debug_objects_enabled)
545                 return;
546
547         db = get_bucket((unsigned long) addr);
548
549         raw_spin_lock_irqsave(&db->lock, flags);
550
551         obj = lookup_object(addr, db);
552         if (!obj)
553                 goto out_unlock;
554
555         switch (obj->state) {
556         case ODEBUG_STATE_NONE:
557         case ODEBUG_STATE_INIT:
558         case ODEBUG_STATE_INACTIVE:
559                 obj->state = ODEBUG_STATE_DESTROYED;
560                 break;
561         case ODEBUG_STATE_ACTIVE:
562                 debug_print_object(obj, "destroy");
563                 state = obj->state;
564                 raw_spin_unlock_irqrestore(&db->lock, flags);
565                 debug_object_fixup(descr->fixup_destroy, addr, state);
566                 return;
567
568         case ODEBUG_STATE_DESTROYED:
569                 debug_print_object(obj, "destroy");
570                 break;
571         default:
572                 break;
573         }
574 out_unlock:
575         raw_spin_unlock_irqrestore(&db->lock, flags);
576 }
577 EXPORT_SYMBOL_GPL(debug_object_destroy);
578
579 /**
580  * debug_object_free - debug checks when an object is freed
581  * @addr:       address of the object
582  * @descr:      pointer to an object specific debug description structure
583  */
584 void debug_object_free(void *addr, struct debug_obj_descr *descr)
585 {
586         enum debug_obj_state state;
587         struct debug_bucket *db;
588         struct debug_obj *obj;
589         unsigned long flags;
590
591         if (!debug_objects_enabled)
592                 return;
593
594         db = get_bucket((unsigned long) addr);
595
596         raw_spin_lock_irqsave(&db->lock, flags);
597
598         obj = lookup_object(addr, db);
599         if (!obj)
600                 goto out_unlock;
601
602         switch (obj->state) {
603         case ODEBUG_STATE_ACTIVE:
604                 debug_print_object(obj, "free");
605                 state = obj->state;
606                 raw_spin_unlock_irqrestore(&db->lock, flags);
607                 debug_object_fixup(descr->fixup_free, addr, state);
608                 return;
609         default:
610                 hlist_del(&obj->node);
611                 raw_spin_unlock_irqrestore(&db->lock, flags);
612                 free_object(obj);
613                 return;
614         }
615 out_unlock:
616         raw_spin_unlock_irqrestore(&db->lock, flags);
617 }
618 EXPORT_SYMBOL_GPL(debug_object_free);
619
620 /**
621  * debug_object_assert_init - debug checks when object should be init-ed
622  * @addr:       address of the object
623  * @descr:      pointer to an object specific debug description structure
624  */
625 void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
626 {
627         struct debug_bucket *db;
628         struct debug_obj *obj;
629         unsigned long flags;
630
631         if (!debug_objects_enabled)
632                 return;
633
634         db = get_bucket((unsigned long) addr);
635
636         raw_spin_lock_irqsave(&db->lock, flags);
637
638         obj = lookup_object(addr, db);
639         if (!obj) {
640                 struct debug_obj o = { .object = addr,
641                                        .state = ODEBUG_STATE_NOTAVAILABLE,
642                                        .descr = descr };
643
644                 raw_spin_unlock_irqrestore(&db->lock, flags);
645                 /*
646                  * Maybe the object is static, and we let the type specific
647                  * code confirm. Track this static object if true, else invoke
648                  * fixup.
649                  */
650                 if (descr->is_static_object && descr->is_static_object(addr)) {
651                         /* Track this static object */
652                         debug_object_init(addr, descr);
653                 } else {
654                         debug_print_object(&o, "assert_init");
655                         debug_object_fixup(descr->fixup_assert_init, addr,
656                                            ODEBUG_STATE_NOTAVAILABLE);
657                 }
658                 return;
659         }
660
661         raw_spin_unlock_irqrestore(&db->lock, flags);
662 }
663 EXPORT_SYMBOL_GPL(debug_object_assert_init);
664
665 /**
666  * debug_object_active_state - debug checks object usage state machine
667  * @addr:       address of the object
668  * @descr:      pointer to an object specific debug description structure
669  * @expect:     expected state
670  * @next:       state to move to if expected state is found
671  */
672 void
673 debug_object_active_state(void *addr, struct debug_obj_descr *descr,
674                           unsigned int expect, unsigned int next)
675 {
676         struct debug_bucket *db;
677         struct debug_obj *obj;
678         unsigned long flags;
679
680         if (!debug_objects_enabled)
681                 return;
682
683         db = get_bucket((unsigned long) addr);
684
685         raw_spin_lock_irqsave(&db->lock, flags);
686
687         obj = lookup_object(addr, db);
688         if (obj) {
689                 switch (obj->state) {
690                 case ODEBUG_STATE_ACTIVE:
691                         if (obj->astate == expect)
692                                 obj->astate = next;
693                         else
694                                 debug_print_object(obj, "active_state");
695                         break;
696
697                 default:
698                         debug_print_object(obj, "active_state");
699                         break;
700                 }
701         } else {
702                 struct debug_obj o = { .object = addr,
703                                        .state = ODEBUG_STATE_NOTAVAILABLE,
704                                        .descr = descr };
705
706                 debug_print_object(&o, "active_state");
707         }
708
709         raw_spin_unlock_irqrestore(&db->lock, flags);
710 }
711 EXPORT_SYMBOL_GPL(debug_object_active_state);
712
713 #ifdef CONFIG_DEBUG_OBJECTS_FREE
714 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
715 {
716         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
717         struct hlist_node *tmp;
718         HLIST_HEAD(freelist);
719         struct debug_obj_descr *descr;
720         enum debug_obj_state state;
721         struct debug_bucket *db;
722         struct debug_obj *obj;
723         int cnt;
724
725         saddr = (unsigned long) address;
726         eaddr = saddr + size;
727         paddr = saddr & ODEBUG_CHUNK_MASK;
728         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
729         chunks >>= ODEBUG_CHUNK_SHIFT;
730
731         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
732                 db = get_bucket(paddr);
733
734 repeat:
735                 cnt = 0;
736                 raw_spin_lock_irqsave(&db->lock, flags);
737                 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
738                         cnt++;
739                         oaddr = (unsigned long) obj->object;
740                         if (oaddr < saddr || oaddr >= eaddr)
741                                 continue;
742
743                         switch (obj->state) {
744                         case ODEBUG_STATE_ACTIVE:
745                                 debug_print_object(obj, "free");
746                                 descr = obj->descr;
747                                 state = obj->state;
748                                 raw_spin_unlock_irqrestore(&db->lock, flags);
749                                 debug_object_fixup(descr->fixup_free,
750                                                    (void *) oaddr, state);
751                                 goto repeat;
752                         default:
753                                 hlist_del(&obj->node);
754                                 hlist_add_head(&obj->node, &freelist);
755                                 break;
756                         }
757                 }
758                 raw_spin_unlock_irqrestore(&db->lock, flags);
759
760                 /* Now free them */
761                 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
762                         hlist_del(&obj->node);
763                         free_object(obj);
764                 }
765
766                 if (cnt > debug_objects_maxchain)
767                         debug_objects_maxchain = cnt;
768         }
769 }
770
771 void debug_check_no_obj_freed(const void *address, unsigned long size)
772 {
773         if (debug_objects_enabled)
774                 __debug_check_no_obj_freed(address, size);
775 }
776 #endif
777
778 #ifdef CONFIG_DEBUG_FS
779
780 static int debug_stats_show(struct seq_file *m, void *v)
781 {
782         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
783         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
784         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
785         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
786         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
787         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
788         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
789         seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
790         seq_printf(m, "objs_freed    :%d\n", debug_objects_freed);
791         return 0;
792 }
793
794 static int debug_stats_open(struct inode *inode, struct file *filp)
795 {
796         return single_open(filp, debug_stats_show, NULL);
797 }
798
799 static const struct file_operations debug_stats_fops = {
800         .open           = debug_stats_open,
801         .read           = seq_read,
802         .llseek         = seq_lseek,
803         .release        = single_release,
804 };
805
806 static int __init debug_objects_init_debugfs(void)
807 {
808         struct dentry *dbgdir, *dbgstats;
809
810         if (!debug_objects_enabled)
811                 return 0;
812
813         dbgdir = debugfs_create_dir("debug_objects", NULL);
814         if (!dbgdir)
815                 return -ENOMEM;
816
817         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
818                                        &debug_stats_fops);
819         if (!dbgstats)
820                 goto err;
821
822         return 0;
823
824 err:
825         debugfs_remove(dbgdir);
826
827         return -ENOMEM;
828 }
829 __initcall(debug_objects_init_debugfs);
830
831 #else
832 static inline void debug_objects_init_debugfs(void) { }
833 #endif
834
835 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
836
837 /* Random data structure for the self test */
838 struct self_test {
839         unsigned long   dummy1[6];
840         int             static_init;
841         unsigned long   dummy2[3];
842 };
843
844 static __initdata struct debug_obj_descr descr_type_test;
845
846 static bool __init is_static_object(void *addr)
847 {
848         struct self_test *obj = addr;
849
850         return obj->static_init;
851 }
852
853 /*
854  * fixup_init is called when:
855  * - an active object is initialized
856  */
857 static bool __init fixup_init(void *addr, enum debug_obj_state state)
858 {
859         struct self_test *obj = addr;
860
861         switch (state) {
862         case ODEBUG_STATE_ACTIVE:
863                 debug_object_deactivate(obj, &descr_type_test);
864                 debug_object_init(obj, &descr_type_test);
865                 return true;
866         default:
867                 return false;
868         }
869 }
870
871 /*
872  * fixup_activate is called when:
873  * - an active object is activated
874  * - an unknown non-static object is activated
875  */
876 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
877 {
878         struct self_test *obj = addr;
879
880         switch (state) {
881         case ODEBUG_STATE_NOTAVAILABLE:
882                 return true;
883         case ODEBUG_STATE_ACTIVE:
884                 debug_object_deactivate(obj, &descr_type_test);
885                 debug_object_activate(obj, &descr_type_test);
886                 return true;
887
888         default:
889                 return false;
890         }
891 }
892
893 /*
894  * fixup_destroy is called when:
895  * - an active object is destroyed
896  */
897 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
898 {
899         struct self_test *obj = addr;
900
901         switch (state) {
902         case ODEBUG_STATE_ACTIVE:
903                 debug_object_deactivate(obj, &descr_type_test);
904                 debug_object_destroy(obj, &descr_type_test);
905                 return true;
906         default:
907                 return false;
908         }
909 }
910
911 /*
912  * fixup_free is called when:
913  * - an active object is freed
914  */
915 static bool __init fixup_free(void *addr, enum debug_obj_state state)
916 {
917         struct self_test *obj = addr;
918
919         switch (state) {
920         case ODEBUG_STATE_ACTIVE:
921                 debug_object_deactivate(obj, &descr_type_test);
922                 debug_object_free(obj, &descr_type_test);
923                 return true;
924         default:
925                 return false;
926         }
927 }
928
929 static int __init
930 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
931 {
932         struct debug_bucket *db;
933         struct debug_obj *obj;
934         unsigned long flags;
935         int res = -EINVAL;
936
937         db = get_bucket((unsigned long) addr);
938
939         raw_spin_lock_irqsave(&db->lock, flags);
940
941         obj = lookup_object(addr, db);
942         if (!obj && state != ODEBUG_STATE_NONE) {
943                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
944                 goto out;
945         }
946         if (obj && obj->state != state) {
947                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
948                        obj->state, state);
949                 goto out;
950         }
951         if (fixups != debug_objects_fixups) {
952                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
953                        fixups, debug_objects_fixups);
954                 goto out;
955         }
956         if (warnings != debug_objects_warnings) {
957                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
958                        warnings, debug_objects_warnings);
959                 goto out;
960         }
961         res = 0;
962 out:
963         raw_spin_unlock_irqrestore(&db->lock, flags);
964         if (res)
965                 debug_objects_enabled = 0;
966         return res;
967 }
968
969 static __initdata struct debug_obj_descr descr_type_test = {
970         .name                   = "selftest",
971         .is_static_object       = is_static_object,
972         .fixup_init             = fixup_init,
973         .fixup_activate         = fixup_activate,
974         .fixup_destroy          = fixup_destroy,
975         .fixup_free             = fixup_free,
976 };
977
978 static __initdata struct self_test obj = { .static_init = 0 };
979
980 static void __init debug_objects_selftest(void)
981 {
982         int fixups, oldfixups, warnings, oldwarnings;
983         unsigned long flags;
984
985         local_irq_save(flags);
986
987         fixups = oldfixups = debug_objects_fixups;
988         warnings = oldwarnings = debug_objects_warnings;
989         descr_test = &descr_type_test;
990
991         debug_object_init(&obj, &descr_type_test);
992         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
993                 goto out;
994         debug_object_activate(&obj, &descr_type_test);
995         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
996                 goto out;
997         debug_object_activate(&obj, &descr_type_test);
998         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
999                 goto out;
1000         debug_object_deactivate(&obj, &descr_type_test);
1001         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1002                 goto out;
1003         debug_object_destroy(&obj, &descr_type_test);
1004         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1005                 goto out;
1006         debug_object_init(&obj, &descr_type_test);
1007         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1008                 goto out;
1009         debug_object_activate(&obj, &descr_type_test);
1010         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1011                 goto out;
1012         debug_object_deactivate(&obj, &descr_type_test);
1013         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1014                 goto out;
1015         debug_object_free(&obj, &descr_type_test);
1016         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1017                 goto out;
1018
1019         obj.static_init = 1;
1020         debug_object_activate(&obj, &descr_type_test);
1021         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1022                 goto out;
1023         debug_object_init(&obj, &descr_type_test);
1024         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1025                 goto out;
1026         debug_object_free(&obj, &descr_type_test);
1027         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1028                 goto out;
1029
1030 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1031         debug_object_init(&obj, &descr_type_test);
1032         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1033                 goto out;
1034         debug_object_activate(&obj, &descr_type_test);
1035         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1036                 goto out;
1037         __debug_check_no_obj_freed(&obj, sizeof(obj));
1038         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1039                 goto out;
1040 #endif
1041         pr_info("selftest passed\n");
1042
1043 out:
1044         debug_objects_fixups = oldfixups;
1045         debug_objects_warnings = oldwarnings;
1046         descr_test = NULL;
1047
1048         local_irq_restore(flags);
1049 }
1050 #else
1051 static inline void debug_objects_selftest(void) { }
1052 #endif
1053
1054 /*
1055  * Called during early boot to initialize the hash buckets and link
1056  * the static object pool objects into the poll list. After this call
1057  * the object tracker is fully operational.
1058  */
1059 void __init debug_objects_early_init(void)
1060 {
1061         int i;
1062
1063         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1064                 raw_spin_lock_init(&obj_hash[i].lock);
1065
1066         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1067                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1068 }
1069
1070 /*
1071  * Convert the statically allocated objects to dynamic ones:
1072  */
1073 static int __init debug_objects_replace_static_objects(void)
1074 {
1075         struct debug_bucket *db = obj_hash;
1076         struct hlist_node *tmp;
1077         struct debug_obj *obj, *new;
1078         HLIST_HEAD(objects);
1079         int i, cnt = 0;
1080
1081         for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1082                 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1083                 if (!obj)
1084                         goto free;
1085                 kmemleak_ignore(obj);
1086                 hlist_add_head(&obj->node, &objects);
1087         }
1088
1089         /*
1090          * When debug_objects_mem_init() is called we know that only
1091          * one CPU is up, so disabling interrupts is enough
1092          * protection. This avoids the lockdep hell of lock ordering.
1093          */
1094         local_irq_disable();
1095
1096         /* Remove the statically allocated objects from the pool */
1097         hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1098                 hlist_del(&obj->node);
1099         /* Move the allocated objects to the pool */
1100         hlist_move_list(&objects, &obj_pool);
1101
1102         /* Replace the active object references */
1103         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1104                 hlist_move_list(&db->list, &objects);
1105
1106                 hlist_for_each_entry(obj, &objects, node) {
1107                         new = hlist_entry(obj_pool.first, typeof(*obj), node);
1108                         hlist_del(&new->node);
1109                         /* copy object data */
1110                         *new = *obj;
1111                         hlist_add_head(&new->node, &db->list);
1112                         cnt++;
1113                 }
1114         }
1115         local_irq_enable();
1116
1117         pr_debug("%d of %d active objects replaced\n",
1118                  cnt, obj_pool_used);
1119         return 0;
1120 free:
1121         hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1122                 hlist_del(&obj->node);
1123                 kmem_cache_free(obj_cache, obj);
1124         }
1125         return -ENOMEM;
1126 }
1127
1128 /*
1129  * Called after the kmem_caches are functional to setup a dedicated
1130  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1131  * prevents that the debug code is called on kmem_cache_free() for the
1132  * debug tracker objects to avoid recursive calls.
1133  */
1134 void __init debug_objects_mem_init(void)
1135 {
1136         if (!debug_objects_enabled)
1137                 return;
1138
1139         obj_cache = kmem_cache_create("debug_objects_cache",
1140                                       sizeof (struct debug_obj), 0,
1141                                       SLAB_DEBUG_OBJECTS, NULL);
1142
1143         if (!obj_cache || debug_objects_replace_static_objects()) {
1144                 debug_objects_enabled = 0;
1145                 if (obj_cache)
1146                         kmem_cache_destroy(obj_cache);
1147                 pr_warn("out of memory.\n");
1148         } else
1149                 debug_objects_selftest();
1150
1151         /*
1152          * Increase the thresholds for allocating and freeing objects
1153          * according to the number of possible CPUs available in the system.
1154          */
1155         debug_objects_pool_size += num_possible_cpus() * 32;
1156         debug_objects_pool_min_level += num_possible_cpus() * 4;
1157 }