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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#include <linux/cpu.h>
23
24#define ODEBUG_HASH_BITS 14
25#define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
26
27#define ODEBUG_POOL_SIZE 1024
28#define ODEBUG_POOL_MIN_LEVEL 256
29#define ODEBUG_POOL_PERCPU_SIZE 64
30#define ODEBUG_BATCH_SIZE 16
31
32#define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
33#define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
34#define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
35
36
37
38
39
40
41#define ODEBUG_FREE_WORK_MAX 1024
42#define ODEBUG_FREE_WORK_DELAY DIV_ROUND_UP(HZ, 10)
43
44struct debug_bucket {
45 struct hlist_head list;
46 raw_spinlock_t lock;
47};
48
49
50
51
52
53struct debug_percpu_free {
54 struct hlist_head free_objs;
55 int obj_free;
56};
57
58static DEFINE_PER_CPU(struct debug_percpu_free, percpu_obj_pool);
59
60static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
61
62static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
63
64static DEFINE_RAW_SPINLOCK(pool_lock);
65
66static HLIST_HEAD(obj_pool);
67static HLIST_HEAD(obj_to_free);
68
69
70
71
72
73
74
75
76static int obj_pool_min_free = ODEBUG_POOL_SIZE;
77static int obj_pool_free = ODEBUG_POOL_SIZE;
78static int obj_pool_used;
79static int obj_pool_max_used;
80static bool obj_freeing;
81
82static int obj_nr_tofree;
83
84static int debug_objects_maxchain __read_mostly;
85static int __maybe_unused debug_objects_maxchecked __read_mostly;
86static int debug_objects_fixups __read_mostly;
87static int debug_objects_warnings __read_mostly;
88static int debug_objects_enabled __read_mostly
89 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
90static int debug_objects_pool_size __read_mostly
91 = ODEBUG_POOL_SIZE;
92static int debug_objects_pool_min_level __read_mostly
93 = ODEBUG_POOL_MIN_LEVEL;
94static const struct debug_obj_descr *descr_test __read_mostly;
95static struct kmem_cache *obj_cache __read_mostly;
96
97
98
99
100static int debug_objects_allocated;
101static int debug_objects_freed;
102
103static void free_obj_work(struct work_struct *work);
104static DECLARE_DELAYED_WORK(debug_obj_work, free_obj_work);
105
106static int __init enable_object_debug(char *str)
107{
108 debug_objects_enabled = 1;
109 return 0;
110}
111
112static int __init disable_object_debug(char *str)
113{
114 debug_objects_enabled = 0;
115 return 0;
116}
117
118early_param("debug_objects", enable_object_debug);
119early_param("no_debug_objects", disable_object_debug);
120
121static const char *obj_states[ODEBUG_STATE_MAX] = {
122 [ODEBUG_STATE_NONE] = "none",
123 [ODEBUG_STATE_INIT] = "initialized",
124 [ODEBUG_STATE_INACTIVE] = "inactive",
125 [ODEBUG_STATE_ACTIVE] = "active",
126 [ODEBUG_STATE_DESTROYED] = "destroyed",
127 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
128};
129
130static void fill_pool(void)
131{
132 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
133 struct debug_obj *obj;
134 unsigned long flags;
135
136 if (likely(READ_ONCE(obj_pool_free) >= debug_objects_pool_min_level))
137 return;
138
139
140
141
142
143
144
145
146
147 while (READ_ONCE(obj_nr_tofree) && (READ_ONCE(obj_pool_free) < obj_pool_min_free)) {
148 raw_spin_lock_irqsave(&pool_lock, flags);
149
150
151
152
153 while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) {
154 obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
155 hlist_del(&obj->node);
156 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
157 hlist_add_head(&obj->node, &obj_pool);
158 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
159 }
160 raw_spin_unlock_irqrestore(&pool_lock, flags);
161 }
162
163 if (unlikely(!obj_cache))
164 return;
165
166 while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
167 struct debug_obj *new[ODEBUG_BATCH_SIZE];
168 int cnt;
169
170 for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) {
171 new[cnt] = kmem_cache_zalloc(obj_cache, gfp);
172 if (!new[cnt])
173 break;
174 }
175 if (!cnt)
176 return;
177
178 raw_spin_lock_irqsave(&pool_lock, flags);
179 while (cnt) {
180 hlist_add_head(&new[--cnt]->node, &obj_pool);
181 debug_objects_allocated++;
182 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
183 }
184 raw_spin_unlock_irqrestore(&pool_lock, flags);
185 }
186}
187
188
189
190
191static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
192{
193 struct debug_obj *obj;
194 int cnt = 0;
195
196 hlist_for_each_entry(obj, &b->list, node) {
197 cnt++;
198 if (obj->object == addr)
199 return obj;
200 }
201 if (cnt > debug_objects_maxchain)
202 debug_objects_maxchain = cnt;
203
204 return NULL;
205}
206
207
208
209
210static struct debug_obj *__alloc_object(struct hlist_head *list)
211{
212 struct debug_obj *obj = NULL;
213
214 if (list->first) {
215 obj = hlist_entry(list->first, typeof(*obj), node);
216 hlist_del(&obj->node);
217 }
218
219 return obj;
220}
221
222
223
224
225
226static struct debug_obj *
227alloc_object(void *addr, struct debug_bucket *b, const struct debug_obj_descr *descr)
228{
229 struct debug_percpu_free *percpu_pool = this_cpu_ptr(&percpu_obj_pool);
230 struct debug_obj *obj;
231
232 if (likely(obj_cache)) {
233 obj = __alloc_object(&percpu_pool->free_objs);
234 if (obj) {
235 percpu_pool->obj_free--;
236 goto init_obj;
237 }
238 }
239
240 raw_spin_lock(&pool_lock);
241 obj = __alloc_object(&obj_pool);
242 if (obj) {
243 obj_pool_used++;
244 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
245
246
247
248
249
250 if (likely(obj_cache)) {
251 int i;
252
253 for (i = 0; i < ODEBUG_BATCH_SIZE; i++) {
254 struct debug_obj *obj2;
255
256 obj2 = __alloc_object(&obj_pool);
257 if (!obj2)
258 break;
259 hlist_add_head(&obj2->node,
260 &percpu_pool->free_objs);
261 percpu_pool->obj_free++;
262 obj_pool_used++;
263 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
264 }
265 }
266
267 if (obj_pool_used > obj_pool_max_used)
268 obj_pool_max_used = obj_pool_used;
269
270 if (obj_pool_free < obj_pool_min_free)
271 obj_pool_min_free = obj_pool_free;
272 }
273 raw_spin_unlock(&pool_lock);
274
275init_obj:
276 if (obj) {
277 obj->object = addr;
278 obj->descr = descr;
279 obj->state = ODEBUG_STATE_NONE;
280 obj->astate = 0;
281 hlist_add_head(&obj->node, &b->list);
282 }
283 return obj;
284}
285
286
287
288
289
290
291
292static void free_obj_work(struct work_struct *work)
293{
294 struct hlist_node *tmp;
295 struct debug_obj *obj;
296 unsigned long flags;
297 HLIST_HEAD(tofree);
298
299 WRITE_ONCE(obj_freeing, false);
300 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
301 return;
302
303 if (obj_pool_free >= debug_objects_pool_size)
304 goto free_objs;
305
306
307
308
309
310
311
312
313 while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) {
314 obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
315 hlist_del(&obj->node);
316 hlist_add_head(&obj->node, &obj_pool);
317 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
318 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
319 }
320 raw_spin_unlock_irqrestore(&pool_lock, flags);
321 return;
322
323free_objs:
324
325
326
327
328
329 if (obj_nr_tofree) {
330 hlist_move_list(&obj_to_free, &tofree);
331 debug_objects_freed += obj_nr_tofree;
332 WRITE_ONCE(obj_nr_tofree, 0);
333 }
334 raw_spin_unlock_irqrestore(&pool_lock, flags);
335
336 hlist_for_each_entry_safe(obj, tmp, &tofree, node) {
337 hlist_del(&obj->node);
338 kmem_cache_free(obj_cache, obj);
339 }
340}
341
342static void __free_object(struct debug_obj *obj)
343{
344 struct debug_obj *objs[ODEBUG_BATCH_SIZE];
345 struct debug_percpu_free *percpu_pool;
346 int lookahead_count = 0;
347 unsigned long flags;
348 bool work;
349
350 local_irq_save(flags);
351 if (!obj_cache)
352 goto free_to_obj_pool;
353
354
355
356
357 percpu_pool = this_cpu_ptr(&percpu_obj_pool);
358 if (percpu_pool->obj_free < ODEBUG_POOL_PERCPU_SIZE) {
359 hlist_add_head(&obj->node, &percpu_pool->free_objs);
360 percpu_pool->obj_free++;
361 local_irq_restore(flags);
362 return;
363 }
364
365
366
367
368
369 for (; lookahead_count < ODEBUG_BATCH_SIZE; lookahead_count++) {
370 objs[lookahead_count] = __alloc_object(&percpu_pool->free_objs);
371 if (!objs[lookahead_count])
372 break;
373 percpu_pool->obj_free--;
374 }
375
376free_to_obj_pool:
377 raw_spin_lock(&pool_lock);
378 work = (obj_pool_free > debug_objects_pool_size) && obj_cache &&
379 (obj_nr_tofree < ODEBUG_FREE_WORK_MAX);
380 obj_pool_used--;
381
382 if (work) {
383 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
384 hlist_add_head(&obj->node, &obj_to_free);
385 if (lookahead_count) {
386 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + lookahead_count);
387 obj_pool_used -= lookahead_count;
388 while (lookahead_count) {
389 hlist_add_head(&objs[--lookahead_count]->node,
390 &obj_to_free);
391 }
392 }
393
394 if ((obj_pool_free > debug_objects_pool_size) &&
395 (obj_nr_tofree < ODEBUG_FREE_WORK_MAX)) {
396 int i;
397
398
399
400
401 for (i = 0; i < ODEBUG_BATCH_SIZE; i++) {
402 obj = __alloc_object(&obj_pool);
403 hlist_add_head(&obj->node, &obj_to_free);
404 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
405 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
406 }
407 }
408 } else {
409 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
410 hlist_add_head(&obj->node, &obj_pool);
411 if (lookahead_count) {
412 WRITE_ONCE(obj_pool_free, obj_pool_free + lookahead_count);
413 obj_pool_used -= lookahead_count;
414 while (lookahead_count) {
415 hlist_add_head(&objs[--lookahead_count]->node,
416 &obj_pool);
417 }
418 }
419 }
420 raw_spin_unlock(&pool_lock);
421 local_irq_restore(flags);
422}
423
424
425
426
427
428static void free_object(struct debug_obj *obj)
429{
430 __free_object(obj);
431 if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
432 WRITE_ONCE(obj_freeing, true);
433 schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
434 }
435}
436
437#ifdef CONFIG_HOTPLUG_CPU
438static int object_cpu_offline(unsigned int cpu)
439{
440 struct debug_percpu_free *percpu_pool;
441 struct hlist_node *tmp;
442 struct debug_obj *obj;
443
444
445 percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu);
446 hlist_for_each_entry_safe(obj, tmp, &percpu_pool->free_objs, node) {
447 hlist_del(&obj->node);
448 kmem_cache_free(obj_cache, obj);
449 }
450 percpu_pool->obj_free = 0;
451
452 return 0;
453}
454#endif
455
456
457
458
459
460static void debug_objects_oom(void)
461{
462 struct debug_bucket *db = obj_hash;
463 struct hlist_node *tmp;
464 HLIST_HEAD(freelist);
465 struct debug_obj *obj;
466 unsigned long flags;
467 int i;
468
469 pr_warn("Out of memory. ODEBUG disabled\n");
470
471 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
472 raw_spin_lock_irqsave(&db->lock, flags);
473 hlist_move_list(&db->list, &freelist);
474 raw_spin_unlock_irqrestore(&db->lock, flags);
475
476
477 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
478 hlist_del(&obj->node);
479 free_object(obj);
480 }
481 }
482}
483
484
485
486
487
488static struct debug_bucket *get_bucket(unsigned long addr)
489{
490 unsigned long hash;
491
492 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
493 return &obj_hash[hash];
494}
495
496static void debug_print_object(struct debug_obj *obj, char *msg)
497{
498 const struct debug_obj_descr *descr = obj->descr;
499 static int limit;
500
501 if (limit < 5 && descr != descr_test) {
502 void *hint = descr->debug_hint ?
503 descr->debug_hint(obj->object) : NULL;
504 limit++;
505 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
506 "object type: %s hint: %pS\n",
507 msg, obj_states[obj->state], obj->astate,
508 descr->name, hint);
509 }
510 debug_objects_warnings++;
511}
512
513
514
515
516
517static bool
518debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
519 void * addr, enum debug_obj_state state)
520{
521 if (fixup && fixup(addr, state)) {
522 debug_objects_fixups++;
523 return true;
524 }
525 return false;
526}
527
528static void debug_object_is_on_stack(void *addr, int onstack)
529{
530 int is_on_stack;
531 static int limit;
532
533 if (limit > 4)
534 return;
535
536 is_on_stack = object_is_on_stack(addr);
537 if (is_on_stack == onstack)
538 return;
539
540 limit++;
541 if (is_on_stack)
542 pr_warn("object %p is on stack %p, but NOT annotated.\n", addr,
543 task_stack_page(current));
544 else
545 pr_warn("object %p is NOT on stack %p, but annotated.\n", addr,
546 task_stack_page(current));
547
548 WARN_ON(1);
549}
550
551static void
552__debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack)
553{
554 enum debug_obj_state state;
555 bool check_stack = false;
556 struct debug_bucket *db;
557 struct debug_obj *obj;
558 unsigned long flags;
559
560
561
562
563
564 if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible())
565 fill_pool();
566
567 db = get_bucket((unsigned long) addr);
568
569 raw_spin_lock_irqsave(&db->lock, flags);
570
571 obj = lookup_object(addr, db);
572 if (!obj) {
573 obj = alloc_object(addr, db, descr);
574 if (!obj) {
575 debug_objects_enabled = 0;
576 raw_spin_unlock_irqrestore(&db->lock, flags);
577 debug_objects_oom();
578 return;
579 }
580 check_stack = true;
581 }
582
583 switch (obj->state) {
584 case ODEBUG_STATE_NONE:
585 case ODEBUG_STATE_INIT:
586 case ODEBUG_STATE_INACTIVE:
587 obj->state = ODEBUG_STATE_INIT;
588 break;
589
590 case ODEBUG_STATE_ACTIVE:
591 state = obj->state;
592 raw_spin_unlock_irqrestore(&db->lock, flags);
593 debug_print_object(obj, "init");
594 debug_object_fixup(descr->fixup_init, addr, state);
595 return;
596
597 case ODEBUG_STATE_DESTROYED:
598 raw_spin_unlock_irqrestore(&db->lock, flags);
599 debug_print_object(obj, "init");
600 return;
601 default:
602 break;
603 }
604
605 raw_spin_unlock_irqrestore(&db->lock, flags);
606 if (check_stack)
607 debug_object_is_on_stack(addr, onstack);
608}
609
610
611
612
613
614
615void debug_object_init(void *addr, const struct debug_obj_descr *descr)
616{
617 if (!debug_objects_enabled)
618 return;
619
620 __debug_object_init(addr, descr, 0);
621}
622EXPORT_SYMBOL_GPL(debug_object_init);
623
624
625
626
627
628
629
630void debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr)
631{
632 if (!debug_objects_enabled)
633 return;
634
635 __debug_object_init(addr, descr, 1);
636}
637EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
638
639
640
641
642
643
644
645int debug_object_activate(void *addr, const struct debug_obj_descr *descr)
646{
647 enum debug_obj_state state;
648 struct debug_bucket *db;
649 struct debug_obj *obj;
650 unsigned long flags;
651 int ret;
652 struct debug_obj o = { .object = addr,
653 .state = ODEBUG_STATE_NOTAVAILABLE,
654 .descr = descr };
655
656 if (!debug_objects_enabled)
657 return 0;
658
659 db = get_bucket((unsigned long) addr);
660
661 raw_spin_lock_irqsave(&db->lock, flags);
662
663 obj = lookup_object(addr, db);
664 if (obj) {
665 bool print_object = false;
666
667 switch (obj->state) {
668 case ODEBUG_STATE_INIT:
669 case ODEBUG_STATE_INACTIVE:
670 obj->state = ODEBUG_STATE_ACTIVE;
671 ret = 0;
672 break;
673
674 case ODEBUG_STATE_ACTIVE:
675 state = obj->state;
676 raw_spin_unlock_irqrestore(&db->lock, flags);
677 debug_print_object(obj, "activate");
678 ret = debug_object_fixup(descr->fixup_activate, addr, state);
679 return ret ? 0 : -EINVAL;
680
681 case ODEBUG_STATE_DESTROYED:
682 print_object = true;
683 ret = -EINVAL;
684 break;
685 default:
686 ret = 0;
687 break;
688 }
689 raw_spin_unlock_irqrestore(&db->lock, flags);
690 if (print_object)
691 debug_print_object(obj, "activate");
692 return ret;
693 }
694
695 raw_spin_unlock_irqrestore(&db->lock, flags);
696
697
698
699
700
701
702
703
704 if (descr->is_static_object && descr->is_static_object(addr)) {
705
706 debug_object_init(addr, descr);
707 debug_object_activate(addr, descr);
708 } else {
709 debug_print_object(&o, "activate");
710 ret = debug_object_fixup(descr->fixup_activate, addr,
711 ODEBUG_STATE_NOTAVAILABLE);
712 return ret ? 0 : -EINVAL;
713 }
714 return 0;
715}
716EXPORT_SYMBOL_GPL(debug_object_activate);
717
718
719
720
721
722
723void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr)
724{
725 struct debug_bucket *db;
726 struct debug_obj *obj;
727 unsigned long flags;
728 bool print_object = false;
729
730 if (!debug_objects_enabled)
731 return;
732
733 db = get_bucket((unsigned long) addr);
734
735 raw_spin_lock_irqsave(&db->lock, flags);
736
737 obj = lookup_object(addr, db);
738 if (obj) {
739 switch (obj->state) {
740 case ODEBUG_STATE_INIT:
741 case ODEBUG_STATE_INACTIVE:
742 case ODEBUG_STATE_ACTIVE:
743 if (!obj->astate)
744 obj->state = ODEBUG_STATE_INACTIVE;
745 else
746 print_object = true;
747 break;
748
749 case ODEBUG_STATE_DESTROYED:
750 print_object = true;
751 break;
752 default:
753 break;
754 }
755 }
756
757 raw_spin_unlock_irqrestore(&db->lock, flags);
758 if (!obj) {
759 struct debug_obj o = { .object = addr,
760 .state = ODEBUG_STATE_NOTAVAILABLE,
761 .descr = descr };
762
763 debug_print_object(&o, "deactivate");
764 } else if (print_object) {
765 debug_print_object(obj, "deactivate");
766 }
767}
768EXPORT_SYMBOL_GPL(debug_object_deactivate);
769
770
771
772
773
774
775void debug_object_destroy(void *addr, const struct debug_obj_descr *descr)
776{
777 enum debug_obj_state state;
778 struct debug_bucket *db;
779 struct debug_obj *obj;
780 unsigned long flags;
781 bool print_object = false;
782
783 if (!debug_objects_enabled)
784 return;
785
786 db = get_bucket((unsigned long) addr);
787
788 raw_spin_lock_irqsave(&db->lock, flags);
789
790 obj = lookup_object(addr, db);
791 if (!obj)
792 goto out_unlock;
793
794 switch (obj->state) {
795 case ODEBUG_STATE_NONE:
796 case ODEBUG_STATE_INIT:
797 case ODEBUG_STATE_INACTIVE:
798 obj->state = ODEBUG_STATE_DESTROYED;
799 break;
800 case ODEBUG_STATE_ACTIVE:
801 state = obj->state;
802 raw_spin_unlock_irqrestore(&db->lock, flags);
803 debug_print_object(obj, "destroy");
804 debug_object_fixup(descr->fixup_destroy, addr, state);
805 return;
806
807 case ODEBUG_STATE_DESTROYED:
808 print_object = true;
809 break;
810 default:
811 break;
812 }
813out_unlock:
814 raw_spin_unlock_irqrestore(&db->lock, flags);
815 if (print_object)
816 debug_print_object(obj, "destroy");
817}
818EXPORT_SYMBOL_GPL(debug_object_destroy);
819
820
821
822
823
824
825void debug_object_free(void *addr, const struct debug_obj_descr *descr)
826{
827 enum debug_obj_state state;
828 struct debug_bucket *db;
829 struct debug_obj *obj;
830 unsigned long flags;
831
832 if (!debug_objects_enabled)
833 return;
834
835 db = get_bucket((unsigned long) addr);
836
837 raw_spin_lock_irqsave(&db->lock, flags);
838
839 obj = lookup_object(addr, db);
840 if (!obj)
841 goto out_unlock;
842
843 switch (obj->state) {
844 case ODEBUG_STATE_ACTIVE:
845 state = obj->state;
846 raw_spin_unlock_irqrestore(&db->lock, flags);
847 debug_print_object(obj, "free");
848 debug_object_fixup(descr->fixup_free, addr, state);
849 return;
850 default:
851 hlist_del(&obj->node);
852 raw_spin_unlock_irqrestore(&db->lock, flags);
853 free_object(obj);
854 return;
855 }
856out_unlock:
857 raw_spin_unlock_irqrestore(&db->lock, flags);
858}
859EXPORT_SYMBOL_GPL(debug_object_free);
860
861
862
863
864
865
866void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr)
867{
868 struct debug_bucket *db;
869 struct debug_obj *obj;
870 unsigned long flags;
871
872 if (!debug_objects_enabled)
873 return;
874
875 db = get_bucket((unsigned long) addr);
876
877 raw_spin_lock_irqsave(&db->lock, flags);
878
879 obj = lookup_object(addr, db);
880 if (!obj) {
881 struct debug_obj o = { .object = addr,
882 .state = ODEBUG_STATE_NOTAVAILABLE,
883 .descr = descr };
884
885 raw_spin_unlock_irqrestore(&db->lock, flags);
886
887
888
889
890
891 if (descr->is_static_object && descr->is_static_object(addr)) {
892
893 debug_object_init(addr, descr);
894 } else {
895 debug_print_object(&o, "assert_init");
896 debug_object_fixup(descr->fixup_assert_init, addr,
897 ODEBUG_STATE_NOTAVAILABLE);
898 }
899 return;
900 }
901
902 raw_spin_unlock_irqrestore(&db->lock, flags);
903}
904EXPORT_SYMBOL_GPL(debug_object_assert_init);
905
906
907
908
909
910
911
912
913void
914debug_object_active_state(void *addr, const struct debug_obj_descr *descr,
915 unsigned int expect, unsigned int next)
916{
917 struct debug_bucket *db;
918 struct debug_obj *obj;
919 unsigned long flags;
920 bool print_object = false;
921
922 if (!debug_objects_enabled)
923 return;
924
925 db = get_bucket((unsigned long) addr);
926
927 raw_spin_lock_irqsave(&db->lock, flags);
928
929 obj = lookup_object(addr, db);
930 if (obj) {
931 switch (obj->state) {
932 case ODEBUG_STATE_ACTIVE:
933 if (obj->astate == expect)
934 obj->astate = next;
935 else
936 print_object = true;
937 break;
938
939 default:
940 print_object = true;
941 break;
942 }
943 }
944
945 raw_spin_unlock_irqrestore(&db->lock, flags);
946 if (!obj) {
947 struct debug_obj o = { .object = addr,
948 .state = ODEBUG_STATE_NOTAVAILABLE,
949 .descr = descr };
950
951 debug_print_object(&o, "active_state");
952 } else if (print_object) {
953 debug_print_object(obj, "active_state");
954 }
955}
956EXPORT_SYMBOL_GPL(debug_object_active_state);
957
958#ifdef CONFIG_DEBUG_OBJECTS_FREE
959static void __debug_check_no_obj_freed(const void *address, unsigned long size)
960{
961 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
962 const struct debug_obj_descr *descr;
963 enum debug_obj_state state;
964 struct debug_bucket *db;
965 struct hlist_node *tmp;
966 struct debug_obj *obj;
967 int cnt, objs_checked = 0;
968
969 saddr = (unsigned long) address;
970 eaddr = saddr + size;
971 paddr = saddr & ODEBUG_CHUNK_MASK;
972 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
973 chunks >>= ODEBUG_CHUNK_SHIFT;
974
975 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
976 db = get_bucket(paddr);
977
978repeat:
979 cnt = 0;
980 raw_spin_lock_irqsave(&db->lock, flags);
981 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
982 cnt++;
983 oaddr = (unsigned long) obj->object;
984 if (oaddr < saddr || oaddr >= eaddr)
985 continue;
986
987 switch (obj->state) {
988 case ODEBUG_STATE_ACTIVE:
989 descr = obj->descr;
990 state = obj->state;
991 raw_spin_unlock_irqrestore(&db->lock, flags);
992 debug_print_object(obj, "free");
993 debug_object_fixup(descr->fixup_free,
994 (void *) oaddr, state);
995 goto repeat;
996 default:
997 hlist_del(&obj->node);
998 __free_object(obj);
999 break;
1000 }
1001 }
1002 raw_spin_unlock_irqrestore(&db->lock, flags);
1003
1004 if (cnt > debug_objects_maxchain)
1005 debug_objects_maxchain = cnt;
1006
1007 objs_checked += cnt;
1008 }
1009
1010 if (objs_checked > debug_objects_maxchecked)
1011 debug_objects_maxchecked = objs_checked;
1012
1013
1014 if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
1015 WRITE_ONCE(obj_freeing, true);
1016 schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
1017 }
1018}
1019
1020void debug_check_no_obj_freed(const void *address, unsigned long size)
1021{
1022 if (debug_objects_enabled)
1023 __debug_check_no_obj_freed(address, size);
1024}
1025#endif
1026
1027#ifdef CONFIG_DEBUG_FS
1028
1029static int debug_stats_show(struct seq_file *m, void *v)
1030{
1031 int cpu, obj_percpu_free = 0;
1032
1033 for_each_possible_cpu(cpu)
1034 obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu);
1035
1036 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
1037 seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked);
1038 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
1039 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
1040 seq_printf(m, "pool_free :%d\n", READ_ONCE(obj_pool_free) + obj_percpu_free);
1041 seq_printf(m, "pool_pcp_free :%d\n", obj_percpu_free);
1042 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
1043 seq_printf(m, "pool_used :%d\n", obj_pool_used - obj_percpu_free);
1044 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
1045 seq_printf(m, "on_free_list :%d\n", READ_ONCE(obj_nr_tofree));
1046 seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
1047 seq_printf(m, "objs_freed :%d\n", debug_objects_freed);
1048 return 0;
1049}
1050DEFINE_SHOW_ATTRIBUTE(debug_stats);
1051
1052static int __init debug_objects_init_debugfs(void)
1053{
1054 struct dentry *dbgdir;
1055
1056 if (!debug_objects_enabled)
1057 return 0;
1058
1059 dbgdir = debugfs_create_dir("debug_objects", NULL);
1060
1061 debugfs_create_file("stats", 0444, dbgdir, NULL, &debug_stats_fops);
1062
1063 return 0;
1064}
1065__initcall(debug_objects_init_debugfs);
1066
1067#else
1068static inline void debug_objects_init_debugfs(void) { }
1069#endif
1070
1071#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
1072
1073
1074struct self_test {
1075 unsigned long dummy1[6];
1076 int static_init;
1077 unsigned long dummy2[3];
1078};
1079
1080static __initconst const struct debug_obj_descr descr_type_test;
1081
1082static bool __init is_static_object(void *addr)
1083{
1084 struct self_test *obj = addr;
1085
1086 return obj->static_init;
1087}
1088
1089
1090
1091
1092
1093static bool __init fixup_init(void *addr, enum debug_obj_state state)
1094{
1095 struct self_test *obj = addr;
1096
1097 switch (state) {
1098 case ODEBUG_STATE_ACTIVE:
1099 debug_object_deactivate(obj, &descr_type_test);
1100 debug_object_init(obj, &descr_type_test);
1101 return true;
1102 default:
1103 return false;
1104 }
1105}
1106
1107
1108
1109
1110
1111
1112static bool __init fixup_activate(void *addr, enum debug_obj_state state)
1113{
1114 struct self_test *obj = addr;
1115
1116 switch (state) {
1117 case ODEBUG_STATE_NOTAVAILABLE:
1118 return true;
1119 case ODEBUG_STATE_ACTIVE:
1120 debug_object_deactivate(obj, &descr_type_test);
1121 debug_object_activate(obj, &descr_type_test);
1122 return true;
1123
1124 default:
1125 return false;
1126 }
1127}
1128
1129
1130
1131
1132
1133static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
1134{
1135 struct self_test *obj = addr;
1136
1137 switch (state) {
1138 case ODEBUG_STATE_ACTIVE:
1139 debug_object_deactivate(obj, &descr_type_test);
1140 debug_object_destroy(obj, &descr_type_test);
1141 return true;
1142 default:
1143 return false;
1144 }
1145}
1146
1147
1148
1149
1150
1151static bool __init fixup_free(void *addr, enum debug_obj_state state)
1152{
1153 struct self_test *obj = addr;
1154
1155 switch (state) {
1156 case ODEBUG_STATE_ACTIVE:
1157 debug_object_deactivate(obj, &descr_type_test);
1158 debug_object_free(obj, &descr_type_test);
1159 return true;
1160 default:
1161 return false;
1162 }
1163}
1164
1165static int __init
1166check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
1167{
1168 struct debug_bucket *db;
1169 struct debug_obj *obj;
1170 unsigned long flags;
1171 int res = -EINVAL;
1172
1173 db = get_bucket((unsigned long) addr);
1174
1175 raw_spin_lock_irqsave(&db->lock, flags);
1176
1177 obj = lookup_object(addr, db);
1178 if (!obj && state != ODEBUG_STATE_NONE) {
1179 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
1180 goto out;
1181 }
1182 if (obj && obj->state != state) {
1183 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
1184 obj->state, state);
1185 goto out;
1186 }
1187 if (fixups != debug_objects_fixups) {
1188 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
1189 fixups, debug_objects_fixups);
1190 goto out;
1191 }
1192 if (warnings != debug_objects_warnings) {
1193 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
1194 warnings, debug_objects_warnings);
1195 goto out;
1196 }
1197 res = 0;
1198out:
1199 raw_spin_unlock_irqrestore(&db->lock, flags);
1200 if (res)
1201 debug_objects_enabled = 0;
1202 return res;
1203}
1204
1205static __initconst const struct debug_obj_descr descr_type_test = {
1206 .name = "selftest",
1207 .is_static_object = is_static_object,
1208 .fixup_init = fixup_init,
1209 .fixup_activate = fixup_activate,
1210 .fixup_destroy = fixup_destroy,
1211 .fixup_free = fixup_free,
1212};
1213
1214static __initdata struct self_test obj = { .static_init = 0 };
1215
1216static void __init debug_objects_selftest(void)
1217{
1218 int fixups, oldfixups, warnings, oldwarnings;
1219 unsigned long flags;
1220
1221 local_irq_save(flags);
1222
1223 fixups = oldfixups = debug_objects_fixups;
1224 warnings = oldwarnings = debug_objects_warnings;
1225 descr_test = &descr_type_test;
1226
1227 debug_object_init(&obj, &descr_type_test);
1228 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1229 goto out;
1230 debug_object_activate(&obj, &descr_type_test);
1231 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1232 goto out;
1233 debug_object_activate(&obj, &descr_type_test);
1234 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
1235 goto out;
1236 debug_object_deactivate(&obj, &descr_type_test);
1237 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1238 goto out;
1239 debug_object_destroy(&obj, &descr_type_test);
1240 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1241 goto out;
1242 debug_object_init(&obj, &descr_type_test);
1243 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1244 goto out;
1245 debug_object_activate(&obj, &descr_type_test);
1246 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1247 goto out;
1248 debug_object_deactivate(&obj, &descr_type_test);
1249 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1250 goto out;
1251 debug_object_free(&obj, &descr_type_test);
1252 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1253 goto out;
1254
1255 obj.static_init = 1;
1256 debug_object_activate(&obj, &descr_type_test);
1257 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1258 goto out;
1259 debug_object_init(&obj, &descr_type_test);
1260 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1261 goto out;
1262 debug_object_free(&obj, &descr_type_test);
1263 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1264 goto out;
1265
1266#ifdef CONFIG_DEBUG_OBJECTS_FREE
1267 debug_object_init(&obj, &descr_type_test);
1268 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1269 goto out;
1270 debug_object_activate(&obj, &descr_type_test);
1271 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1272 goto out;
1273 __debug_check_no_obj_freed(&obj, sizeof(obj));
1274 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1275 goto out;
1276#endif
1277 pr_info("selftest passed\n");
1278
1279out:
1280 debug_objects_fixups = oldfixups;
1281 debug_objects_warnings = oldwarnings;
1282 descr_test = NULL;
1283
1284 local_irq_restore(flags);
1285}
1286#else
1287static inline void debug_objects_selftest(void) { }
1288#endif
1289
1290
1291
1292
1293
1294
1295void __init debug_objects_early_init(void)
1296{
1297 int i;
1298
1299 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1300 raw_spin_lock_init(&obj_hash[i].lock);
1301
1302 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1303 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1304}
1305
1306
1307
1308
1309static int __init debug_objects_replace_static_objects(void)
1310{
1311 struct debug_bucket *db = obj_hash;
1312 struct hlist_node *tmp;
1313 struct debug_obj *obj, *new;
1314 HLIST_HEAD(objects);
1315 int i, cnt = 0;
1316
1317 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1318 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1319 if (!obj)
1320 goto free;
1321 hlist_add_head(&obj->node, &objects);
1322 }
1323
1324
1325
1326
1327
1328
1329
1330
1331 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1332 hlist_del(&obj->node);
1333
1334 hlist_move_list(&objects, &obj_pool);
1335
1336
1337 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1338 hlist_move_list(&db->list, &objects);
1339
1340 hlist_for_each_entry(obj, &objects, node) {
1341 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1342 hlist_del(&new->node);
1343
1344 *new = *obj;
1345 hlist_add_head(&new->node, &db->list);
1346 cnt++;
1347 }
1348 }
1349
1350 pr_debug("%d of %d active objects replaced\n",
1351 cnt, obj_pool_used);
1352 return 0;
1353free:
1354 hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1355 hlist_del(&obj->node);
1356 kmem_cache_free(obj_cache, obj);
1357 }
1358 return -ENOMEM;
1359}
1360
1361
1362
1363
1364
1365
1366
1367void __init debug_objects_mem_init(void)
1368{
1369 int cpu, extras;
1370
1371 if (!debug_objects_enabled)
1372 return;
1373
1374
1375
1376
1377
1378
1379
1380 for_each_possible_cpu(cpu)
1381 INIT_HLIST_HEAD(&per_cpu(percpu_obj_pool.free_objs, cpu));
1382
1383 obj_cache = kmem_cache_create("debug_objects_cache",
1384 sizeof (struct debug_obj), 0,
1385 SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE,
1386 NULL);
1387
1388 if (!obj_cache || debug_objects_replace_static_objects()) {
1389 debug_objects_enabled = 0;
1390 kmem_cache_destroy(obj_cache);
1391 pr_warn("out of memory.\n");
1392 } else
1393 debug_objects_selftest();
1394
1395#ifdef CONFIG_HOTPLUG_CPU
1396 cpuhp_setup_state_nocalls(CPUHP_DEBUG_OBJ_DEAD, "object:offline", NULL,
1397 object_cpu_offline);
1398#endif
1399
1400
1401
1402
1403
1404 extras = num_possible_cpus() * ODEBUG_BATCH_SIZE;
1405 debug_objects_pool_size += extras;
1406 debug_objects_pool_min_level += extras;
1407}
1408