1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Generic infrastructure for lifetime debugging of objects.
4 *
5 * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de>
6 */
7
8 #define pr_fmt(fmt) "ODEBUG: " fmt
9
10 #include <linux/debugobjects.h>
11 #include <linux/interrupt.h>
12 #include <linux/sched.h>
13 #include <linux/sched/task_stack.h>
14 #include <linux/seq_file.h>
15 #include <linux/debugfs.h>
16 #include <linux/slab.h>
17 #include <linux/hash.h>
18 #include <linux/kmemleak.h>
19 #include <linux/cpu.h>
20
21 #define ODEBUG_HASH_BITS 14
22 #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
23
24 #define ODEBUG_POOL_SIZE 1024
25 #define ODEBUG_POOL_MIN_LEVEL 256
26 #define ODEBUG_POOL_PERCPU_SIZE 64
27 #define ODEBUG_BATCH_SIZE 16
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 /*
34 * We limit the freeing of debug objects via workqueue at a maximum
35 * frequency of 10Hz and about 1024 objects for each freeing operation.
36 * So it is freeing at most 10k debug objects per second.
37 */
38 #define ODEBUG_FREE_WORK_MAX 1024
39 #define ODEBUG_FREE_WORK_DELAY DIV_ROUND_UP(HZ, 10)
40
41 struct debug_bucket {
42 struct hlist_head list;
43 raw_spinlock_t lock;
44 };
45
46 /*
47 * Debug object percpu free list
48 * Access is protected by disabling irq
49 */
50 struct debug_percpu_free {
51 struct hlist_head free_objs;
52 int obj_free;
53 };
54
55 static DEFINE_PER_CPU(struct debug_percpu_free, percpu_obj_pool);
56
57 static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
58
59 static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
60
61 static DEFINE_RAW_SPINLOCK(pool_lock);
62
63 static HLIST_HEAD(obj_pool);
64 static HLIST_HEAD(obj_to_free);
65
66 /*
67 * Because of the presence of percpu free pools, obj_pool_free will
68 * under-count those in the percpu free pools. Similarly, obj_pool_used
69 * will over-count those in the percpu free pools. Adjustments will be
70 * made at debug_stats_show(). Both obj_pool_min_free and obj_pool_max_used
71 * can be off.
72 */
73 static int obj_pool_min_free = ODEBUG_POOL_SIZE;
74 static int obj_pool_free = ODEBUG_POOL_SIZE;
75 static int obj_pool_used;
76 static int obj_pool_max_used;
77 static bool obj_freeing;
78 /* The number of objs on the global free list */
79 static int obj_nr_tofree;
80
81 static int __data_racy debug_objects_maxchain __read_mostly;
82 static int __data_racy __maybe_unused debug_objects_maxchecked __read_mostly;
83 static int __data_racy debug_objects_fixups __read_mostly;
84 static int __data_racy debug_objects_warnings __read_mostly;
85 static int __data_racy debug_objects_enabled __read_mostly
86 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
87 static int __data_racy debug_objects_pool_size __read_mostly
88 = ODEBUG_POOL_SIZE;
89 static int __data_racy debug_objects_pool_min_level __read_mostly
90 = ODEBUG_POOL_MIN_LEVEL;
91
92 static const struct debug_obj_descr *descr_test __read_mostly;
93 static struct kmem_cache *obj_cache __ro_after_init;
94
95 /*
96 * Track numbers of kmem_cache_alloc()/free() calls done.
97 */
98 static int debug_objects_allocated;
99 static int debug_objects_freed;
100
101 static void free_obj_work(struct work_struct *work);
102 static DECLARE_DELAYED_WORK(debug_obj_work, free_obj_work);
103
104 static int __init enable_object_debug(char *str)
105 {
106 debug_objects_enabled = 1;
107 return 0;
108 }
109
110 static int __init disable_object_debug(char *str)
111 {
112 debug_objects_enabled = 0;
113 return 0;
114 }
115
116 early_param("debug_objects", enable_object_debug);
117 early_param("no_debug_objects", disable_object_debug);
118
119 static const char *obj_states[ODEBUG_STATE_MAX] = {
120 [ODEBUG_STATE_NONE] = "none",
121 [ODEBUG_STATE_INIT] = "initialized",
122 [ODEBUG_STATE_INACTIVE] = "inactive",
123 [ODEBUG_STATE_ACTIVE] = "active",
124 [ODEBUG_STATE_DESTROYED] = "destroyed",
125 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
126 };
127
128 static void fill_pool(void)
129 {
130 gfp_t gfp = __GFP_HIGH | __GFP_NOWARN;
131 struct debug_obj *obj;
132 unsigned long flags;
133
134 if (likely(READ_ONCE(obj_pool_free) >= debug_objects_pool_min_level))
135 return;
136
137 /*
138 * Reuse objs from the global free list; they will be reinitialized
139 * when allocating.
140 *
141 * Both obj_nr_tofree and obj_pool_free are checked locklessly; the
142 * READ_ONCE()s pair with the WRITE_ONCE()s in pool_lock critical
143 * sections.
144 */
145 while (READ_ONCE(obj_nr_tofree) &&
146 READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
147 raw_spin_lock_irqsave(&pool_lock, flags);
148 /*
149 * Recheck with the lock held as the worker thread might have
150 * won the race and freed the global free list already.
151 */
152 while (obj_nr_tofree && (obj_pool_free < debug_objects_pool_min_level)) {
153 obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
154 hlist_del(&obj->node);
155 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
156 hlist_add_head(&obj->node, &obj_pool);
157 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
158 }
159 raw_spin_unlock_irqrestore(&pool_lock, flags);
160 }
161
162 if (unlikely(!obj_cache))
163 return;
164
165 while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
166 struct debug_obj *new[ODEBUG_BATCH_SIZE];
167 int cnt;
168
169 for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) {
170 new[cnt] = kmem_cache_zalloc(obj_cache, gfp);
171 if (!new[cnt])
172 break;
173 }
174 if (!cnt)
175 return;
176
177 raw_spin_lock_irqsave(&pool_lock, flags);
178 while (cnt) {
179 hlist_add_head(&new[--cnt]->node, &obj_pool);
180 debug_objects_allocated++;
181 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
182 }
183 raw_spin_unlock_irqrestore(&pool_lock, flags);
184 }
185 }
186
187 /*
188 * Lookup an object in the hash bucket.
189 */
190 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
191 {
192 struct debug_obj *obj;
193 int cnt = 0;
194
195 hlist_for_each_entry(obj, &b->list, node) {
196 cnt++;
197 if (obj->object == addr)
198 return obj;
199 }
200 if (cnt > debug_objects_maxchain)
201 debug_objects_maxchain = cnt;
202
203 return NULL;
204 }
205
206 /*
207 * Allocate a new object from the hlist
208 */
209 static struct debug_obj *__alloc_object(struct hlist_head *list)
210 {
211 struct debug_obj *obj = NULL;
212
213 if (list->first) {
214 obj = hlist_entry(list->first, typeof(*obj), node);
215 hlist_del(&obj->node);
216 }
217
218 return obj;
219 }
220
221 static struct debug_obj *
222 alloc_object(void *addr, struct debug_bucket *b, const struct debug_obj_descr *descr)
223 {
224 struct debug_percpu_free *percpu_pool = this_cpu_ptr(&percpu_obj_pool);
225 struct debug_obj *obj;
226
227 if (likely(obj_cache)) {
228 obj = __alloc_object(&percpu_pool->free_objs);
229 if (obj) {
230 percpu_pool->obj_free--;
231 goto init_obj;
232 }
233 }
234
235 raw_spin_lock(&pool_lock);
236 obj = __alloc_object(&obj_pool);
237 if (obj) {
238 obj_pool_used++;
239 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
240
241 /*
242 * Looking ahead, allocate one batch of debug objects and
243 * put them into the percpu free pool.
244 */
245 if (likely(obj_cache)) {
246 int i;
247
248 for (i = 0; i < ODEBUG_BATCH_SIZE; i++) {
249 struct debug_obj *obj2;
250
251 obj2 = __alloc_object(&obj_pool);
252 if (!obj2)
253 break;
254 hlist_add_head(&obj2->node,
255 &percpu_pool->free_objs);
256 percpu_pool->obj_free++;
257 obj_pool_used++;
258 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
259 }
260 }
261
262 if (obj_pool_used > obj_pool_max_used)
263 obj_pool_max_used = obj_pool_used;
264
265 if (obj_pool_free < obj_pool_min_free)
266 obj_pool_min_free = obj_pool_free;
267 }
268 raw_spin_unlock(&pool_lock);
269
270 init_obj:
271 if (obj) {
272 obj->object = addr;
273 obj->descr = descr;
274 obj->state = ODEBUG_STATE_NONE;
275 obj->astate = 0;
276 hlist_add_head(&obj->node, &b->list);
277 }
278 return obj;
279 }
280
281 /*
282 * workqueue function to free objects.
283 *
284 * To reduce contention on the global pool_lock, the actual freeing of
285 * debug objects will be delayed if the pool_lock is busy.
286 */
287 static void free_obj_work(struct work_struct *work)
288 {
289 struct hlist_node *tmp;
290 struct debug_obj *obj;
291 unsigned long flags;
292 HLIST_HEAD(tofree);
293
294 WRITE_ONCE(obj_freeing, false);
295 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
296 return;
297
298 if (obj_pool_free >= debug_objects_pool_size)
299 goto free_objs;
300
301 /*
302 * The objs on the pool list might be allocated before the work is
303 * run, so recheck if pool list it full or not, if not fill pool
304 * list from the global free list. As it is likely that a workload
305 * may be gearing up to use more and more objects, don't free any
306 * of them until the next round.
307 */
308 while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) {
309 obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
310 hlist_del(&obj->node);
311 hlist_add_head(&obj->node, &obj_pool);
312 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
313 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
314 }
315 raw_spin_unlock_irqrestore(&pool_lock, flags);
316 return;
317
318 free_objs:
319 /*
320 * Pool list is already full and there are still objs on the free
321 * list. Move remaining free objs to a temporary list to free the
322 * memory outside the pool_lock held region.
323 */
324 if (obj_nr_tofree) {
325 hlist_move_list(&obj_to_free, &tofree);
326 debug_objects_freed += obj_nr_tofree;
327 WRITE_ONCE(obj_nr_tofree, 0);
328 }
329 raw_spin_unlock_irqrestore(&pool_lock, flags);
330
331 hlist_for_each_entry_safe(obj, tmp, &tofree, node) {
332 hlist_del(&obj->node);
333 kmem_cache_free(obj_cache, obj);
334 }
335 }
336
337 static void __free_object(struct debug_obj *obj)
338 {
339 struct debug_obj *objs[ODEBUG_BATCH_SIZE];
340 struct debug_percpu_free *percpu_pool;
341 int lookahead_count = 0;
342 unsigned long flags;
343 bool work;
344
345 local_irq_save(flags);
346 if (!obj_cache)
347 goto free_to_obj_pool;
348
349 /*
350 * Try to free it into the percpu pool first.
351 */
352 percpu_pool = this_cpu_ptr(&percpu_obj_pool);
353 if (percpu_pool->obj_free < ODEBUG_POOL_PERCPU_SIZE) {
354 hlist_add_head(&obj->node, &percpu_pool->free_objs);
355 percpu_pool->obj_free++;
356 local_irq_restore(flags);
357 return;
358 }
359
360 /*
361 * As the percpu pool is full, look ahead and pull out a batch
362 * of objects from the percpu pool and free them as well.
363 */
364 for (; lookahead_count < ODEBUG_BATCH_SIZE; lookahead_count++) {
365 objs[lookahead_count] = __alloc_object(&percpu_pool->free_objs);
366 if (!objs[lookahead_count])
367 break;
368 percpu_pool->obj_free--;
369 }
370
371 free_to_obj_pool:
372 raw_spin_lock(&pool_lock);
373 work = (obj_pool_free > debug_objects_pool_size) && obj_cache &&
374 (obj_nr_tofree < ODEBUG_FREE_WORK_MAX);
375 obj_pool_used--;
376
377 if (work) {
378 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
379 hlist_add_head(&obj->node, &obj_to_free);
380 if (lookahead_count) {
381 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + lookahead_count);
382 obj_pool_used -= lookahead_count;
383 while (lookahead_count) {
384 hlist_add_head(&objs[--lookahead_count]->node,
385 &obj_to_free);
386 }
387 }
388
389 if ((obj_pool_free > debug_objects_pool_size) &&
390 (obj_nr_tofree < ODEBUG_FREE_WORK_MAX)) {
391 int i;
392
393 /*
394 * Free one more batch of objects from obj_pool.
395 */
396 for (i = 0; i < ODEBUG_BATCH_SIZE; i++) {
397 obj = __alloc_object(&obj_pool);
398 hlist_add_head(&obj->node, &obj_to_free);
399 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
400 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
401 }
402 }
403 } else {
404 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
405 hlist_add_head(&obj->node, &obj_pool);
406 if (lookahead_count) {
407 WRITE_ONCE(obj_pool_free, obj_pool_free + lookahead_count);
408 obj_pool_used -= lookahead_count;
409 while (lookahead_count) {
410 hlist_add_head(&objs[--lookahead_count]->node,
411 &obj_pool);
412 }
413 }
414 }
415 raw_spin_unlock(&pool_lock);
416 local_irq_restore(flags);
417 }
418
419 /*
420 * Put the object back into the pool and schedule work to free objects
421 * if necessary.
422 */
423 static void free_object(struct debug_obj *obj)
424 {
425 __free_object(obj);
426 if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
427 WRITE_ONCE(obj_freeing, true);
428 schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
429 }
430 }
431
432 #ifdef CONFIG_HOTPLUG_CPU
433 static int object_cpu_offline(unsigned int cpu)
434 {
435 struct debug_percpu_free *percpu_pool;
436 struct hlist_node *tmp;
437 struct debug_obj *obj;
438 unsigned long flags;
439
440 /* Remote access is safe as the CPU is dead already */
441 percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu);
442 hlist_for_each_entry_safe(obj, tmp, &percpu_pool->free_objs, node) {
443 hlist_del(&obj->node);
444 kmem_cache_free(obj_cache, obj);
445 }
446
447 raw_spin_lock_irqsave(&pool_lock, flags);
448 obj_pool_used -= percpu_pool->obj_free;
449 debug_objects_freed += percpu_pool->obj_free;
450 raw_spin_unlock_irqrestore(&pool_lock, flags);
451
452 percpu_pool->obj_free = 0;
453
454 return 0;
455 }
456 #endif
457
458 /*
459 * We run out of memory. That means we probably have tons of objects
460 * allocated.
461 */
462 static void debug_objects_oom(void)
463 {
464 struct debug_bucket *db = obj_hash;
465 struct hlist_node *tmp;
466 HLIST_HEAD(freelist);
467 struct debug_obj *obj;
468 unsigned long flags;
469 int i;
470
471 pr_warn("Out of memory. ODEBUG disabled\n");
472
473 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
474 raw_spin_lock_irqsave(&db->lock, flags);
475 hlist_move_list(&db->list, &freelist);
476 raw_spin_unlock_irqrestore(&db->lock, flags);
477
478 /* Now free them */
479 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
480 hlist_del(&obj->node);
481 free_object(obj);
482 }
483 }
484 }
485
486 /*
487 * We use the pfn of the address for the hash. That way we can check
488 * for freed objects simply by checking the affected bucket.
489 */
490 static struct debug_bucket *get_bucket(unsigned long addr)
491 {
492 unsigned long hash;
493
494 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
495 return &obj_hash[hash];
496 }
497
498 static void debug_print_object(struct debug_obj *obj, char *msg)
499 {
500 const struct debug_obj_descr *descr = obj->descr;
501 static int limit;
502
503 /*
504 * Don't report if lookup_object_or_alloc() by the current thread
505 * failed because lookup_object_or_alloc()/debug_objects_oom() by a
506 * concurrent thread turned off debug_objects_enabled and cleared
507 * the hash buckets.
508 */
509 if (!debug_objects_enabled)
510 return;
511
512 if (limit < 5 && descr != descr_test) {
513 void *hint = descr->debug_hint ?
514 descr->debug_hint(obj->object) : NULL;
515 limit++;
516 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
517 "object: %p object type: %s hint: %pS\n",
518 msg, obj_states[obj->state], obj->astate,
519 obj->object, descr->name, hint);
520 }
521 debug_objects_warnings++;
522 }
523
524 /*
525 * Try to repair the damage, so we have a better chance to get useful
526 * debug output.
527 */
528 static bool
529 debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
530 void * addr, enum debug_obj_state state)
531 {
532 if (fixup && fixup(addr, state)) {
533 debug_objects_fixups++;
534 return true;
535 }
536 return false;
537 }
538
539 static void debug_object_is_on_stack(void *addr, int onstack)
540 {
541 int is_on_stack;
542 static int limit;
543
544 if (limit > 4)
545 return;
546
547 is_on_stack = object_is_on_stack(addr);
548 if (is_on_stack == onstack)
549 return;
550
551 limit++;
552 if (is_on_stack)
553 pr_warn("object %p is on stack %p, but NOT annotated.\n", addr,
554 task_stack_page(current));
555 else
556 pr_warn("object %p is NOT on stack %p, but annotated.\n", addr,
557 task_stack_page(current));
558
559 WARN_ON(1);
560 }
561
562 static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket *b,
563 const struct debug_obj_descr *descr,
564 bool onstack, bool alloc_ifstatic)
565 {
566 struct debug_obj *obj = lookup_object(addr, b);
567 enum debug_obj_state state = ODEBUG_STATE_NONE;
568
569 if (likely(obj))
570 return obj;
571
572 /*
573 * debug_object_init() unconditionally allocates untracked
574 * objects. It does not matter whether it is a static object or
575 * not.
576 *
577 * debug_object_assert_init() and debug_object_activate() allow
578 * allocation only if the descriptor callback confirms that the
579 * object is static and considered initialized. For non-static
580 * objects the allocation needs to be done from the fixup callback.
581 */
582 if (unlikely(alloc_ifstatic)) {
583 if (!descr->is_static_object || !descr->is_static_object(addr))
584 return ERR_PTR(-ENOENT);
585 /* Statically allocated objects are considered initialized */
586 state = ODEBUG_STATE_INIT;
587 }
588
589 obj = alloc_object(addr, b, descr);
590 if (likely(obj)) {
591 obj->state = state;
592 debug_object_is_on_stack(addr, onstack);
593 return obj;
594 }
595
596 /* Out of memory. Do the cleanup outside of the locked region */
597 debug_objects_enabled = 0;
598 return NULL;
599 }
600
601 static void debug_objects_fill_pool(void)
602 {
603 /*
604 * On RT enabled kernels the pool refill must happen in preemptible
605 * context -- for !RT kernels we rely on the fact that spinlock_t and
606 * raw_spinlock_t are basically the same type and this lock-type
607 * inversion works just fine.
608 */
609 if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) {
610 /*
611 * Annotate away the spinlock_t inside raw_spinlock_t warning
612 * by temporarily raising the wait-type to WAIT_SLEEP, matching
613 * the preemptible() condition above.
614 */
615 static DEFINE_WAIT_OVERRIDE_MAP(fill_pool_map, LD_WAIT_SLEEP);
616 lock_map_acquire_try(&fill_pool_map);
617 fill_pool();
618 lock_map_release(&fill_pool_map);
619 }
620 }
621
622 static void
623 __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack)
624 {
625 struct debug_obj *obj, o;
626 struct debug_bucket *db;
627 unsigned long flags;
628
629 debug_objects_fill_pool();
630
631 db = get_bucket((unsigned long) addr);
632
633 raw_spin_lock_irqsave(&db->lock, flags);
634
635 obj = lookup_object_or_alloc(addr, db, descr, onstack, false);
636 if (unlikely(!obj)) {
637 raw_spin_unlock_irqrestore(&db->lock, flags);
638 debug_objects_oom();
639 return;
640 }
641
642 switch (obj->state) {
643 case ODEBUG_STATE_NONE:
644 case ODEBUG_STATE_INIT:
645 case ODEBUG_STATE_INACTIVE:
646 obj->state = ODEBUG_STATE_INIT;
647 raw_spin_unlock_irqrestore(&db->lock, flags);
648 return;
649 default:
650 break;
651 }
652
653 o = *obj;
654 raw_spin_unlock_irqrestore(&db->lock, flags);
655 debug_print_object(&o, "init");
656
657 if (o.state == ODEBUG_STATE_ACTIVE)
658 debug_object_fixup(descr->fixup_init, addr, o.state);
659 }
660
661 /**
662 * debug_object_init - debug checks when an object is initialized
663 * @addr: address of the object
664 * @descr: pointer to an object specific debug description structure
665 */
666 void debug_object_init(void *addr, const struct debug_obj_descr *descr)
667 {
668 if (!debug_objects_enabled)
669 return;
670
671 __debug_object_init(addr, descr, 0);
672 }
673 EXPORT_SYMBOL_GPL(debug_object_init);
674
675 /**
676 * debug_object_init_on_stack - debug checks when an object on stack is
677 * initialized
678 * @addr: address of the object
679 * @descr: pointer to an object specific debug description structure
680 */
681 void debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr)
682 {
683 if (!debug_objects_enabled)
684 return;
685
686 __debug_object_init(addr, descr, 1);
687 }
688 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
689
690 /**
691 * debug_object_activate - debug checks when an object is activated
692 * @addr: address of the object
693 * @descr: pointer to an object specific debug description structure
694 * Returns 0 for success, -EINVAL for check failed.
695 */
696 int debug_object_activate(void *addr, const struct debug_obj_descr *descr)
697 {
698 struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
699 struct debug_bucket *db;
700 struct debug_obj *obj;
701 unsigned long flags;
702
703 if (!debug_objects_enabled)
704 return 0;
705
706 debug_objects_fill_pool();
707
708 db = get_bucket((unsigned long) addr);
709
710 raw_spin_lock_irqsave(&db->lock, flags);
711
712 obj = lookup_object_or_alloc(addr, db, descr, false, true);
713 if (unlikely(!obj)) {
714 raw_spin_unlock_irqrestore(&db->lock, flags);
715 debug_objects_oom();
716 return 0;
717 } else if (likely(!IS_ERR(obj))) {
718 switch (obj->state) {
719 case ODEBUG_STATE_ACTIVE:
720 case ODEBUG_STATE_DESTROYED:
721 o = *obj;
722 break;
723 case ODEBUG_STATE_INIT:
724 case ODEBUG_STATE_INACTIVE:
725 obj->state = ODEBUG_STATE_ACTIVE;
726 fallthrough;
727 default:
728 raw_spin_unlock_irqrestore(&db->lock, flags);
729 return 0;
730 }
731 }
732
733 raw_spin_unlock_irqrestore(&db->lock, flags);
734 debug_print_object(&o, "activate");
735
736 switch (o.state) {
737 case ODEBUG_STATE_ACTIVE:
738 case ODEBUG_STATE_NOTAVAILABLE:
739 if (debug_object_fixup(descr->fixup_activate, addr, o.state))
740 return 0;
741 fallthrough;
742 default:
743 return -EINVAL;
744 }
745 }
746 EXPORT_SYMBOL_GPL(debug_object_activate);
747
748 /**
749 * debug_object_deactivate - debug checks when an object is deactivated
750 * @addr: address of the object
751 * @descr: pointer to an object specific debug description structure
752 */
753 void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr)
754 {
755 struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
756 struct debug_bucket *db;
757 struct debug_obj *obj;
758 unsigned long flags;
759
760 if (!debug_objects_enabled)
761 return;
762
763 db = get_bucket((unsigned long) addr);
764
765 raw_spin_lock_irqsave(&db->lock, flags);
766
767 obj = lookup_object(addr, db);
768 if (obj) {
769 switch (obj->state) {
770 case ODEBUG_STATE_DESTROYED:
771 break;
772 case ODEBUG_STATE_INIT:
773 case ODEBUG_STATE_INACTIVE:
774 case ODEBUG_STATE_ACTIVE:
775 if (obj->astate)
776 break;
777 obj->state = ODEBUG_STATE_INACTIVE;
778 fallthrough;
779 default:
780 raw_spin_unlock_irqrestore(&db->lock, flags);
781 return;
782 }
783 o = *obj;
784 }
785
786 raw_spin_unlock_irqrestore(&db->lock, flags);
787 debug_print_object(&o, "deactivate");
788 }
789 EXPORT_SYMBOL_GPL(debug_object_deactivate);
790
791 /**
792 * debug_object_destroy - debug checks when an object is destroyed
793 * @addr: address of the object
794 * @descr: pointer to an object specific debug description structure
795 */
796 void debug_object_destroy(void *addr, const struct debug_obj_descr *descr)
797 {
798 struct debug_obj *obj, o;
799 struct debug_bucket *db;
800 unsigned long flags;
801
802 if (!debug_objects_enabled)
803 return;
804
805 db = get_bucket((unsigned long) addr);
806
807 raw_spin_lock_irqsave(&db->lock, flags);
808
809 obj = lookup_object(addr, db);
810 if (!obj) {
811 raw_spin_unlock_irqrestore(&db->lock, flags);
812 return;
813 }
814
815 switch (obj->state) {
816 case ODEBUG_STATE_ACTIVE:
817 case ODEBUG_STATE_DESTROYED:
818 break;
819 case ODEBUG_STATE_NONE:
820 case ODEBUG_STATE_INIT:
821 case ODEBUG_STATE_INACTIVE:
822 obj->state = ODEBUG_STATE_DESTROYED;
823 fallthrough;
824 default:
825 raw_spin_unlock_irqrestore(&db->lock, flags);
826 return;
827 }
828
829 o = *obj;
830 raw_spin_unlock_irqrestore(&db->lock, flags);
831 debug_print_object(&o, "destroy");
832
833 if (o.state == ODEBUG_STATE_ACTIVE)
834 debug_object_fixup(descr->fixup_destroy, addr, o.state);
835 }
836 EXPORT_SYMBOL_GPL(debug_object_destroy);
837
838 /**
839 * debug_object_free - debug checks when an object is freed
840 * @addr: address of the object
841 * @descr: pointer to an object specific debug description structure
842 */
843 void debug_object_free(void *addr, const struct debug_obj_descr *descr)
844 {
845 struct debug_obj *obj, o;
846 struct debug_bucket *db;
847 unsigned long flags;
848
849 if (!debug_objects_enabled)
850 return;
851
852 db = get_bucket((unsigned long) addr);
853
854 raw_spin_lock_irqsave(&db->lock, flags);
855
856 obj = lookup_object(addr, db);
857 if (!obj) {
858 raw_spin_unlock_irqrestore(&db->lock, flags);
859 return;
860 }
861
862 switch (obj->state) {
863 case ODEBUG_STATE_ACTIVE:
864 break;
865 default:
866 hlist_del(&obj->node);
867 raw_spin_unlock_irqrestore(&db->lock, flags);
868 free_object(obj);
869 return;
870 }
871
872 o = *obj;
873 raw_spin_unlock_irqrestore(&db->lock, flags);
874 debug_print_object(&o, "free");
875
876 debug_object_fixup(descr->fixup_free, addr, o.state);
877 }
878 EXPORT_SYMBOL_GPL(debug_object_free);
879
880 /**
881 * debug_object_assert_init - debug checks when object should be init-ed
882 * @addr: address of the object
883 * @descr: pointer to an object specific debug description structure
884 */
885 void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr)
886 {
887 struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
888 struct debug_bucket *db;
889 struct debug_obj *obj;
890 unsigned long flags;
891
892 if (!debug_objects_enabled)
893 return;
894
895 debug_objects_fill_pool();
896
897 db = get_bucket((unsigned long) addr);
898
899 raw_spin_lock_irqsave(&db->lock, flags);
900 obj = lookup_object_or_alloc(addr, db, descr, false, true);
901 raw_spin_unlock_irqrestore(&db->lock, flags);
902 if (likely(!IS_ERR_OR_NULL(obj)))
903 return;
904
905 /* If NULL the allocation has hit OOM */
906 if (!obj) {
907 debug_objects_oom();
908 return;
909 }
910
911 /* Object is neither tracked nor static. It's not initialized. */
912 debug_print_object(&o, "assert_init");
913 debug_object_fixup(descr->fixup_assert_init, addr, ODEBUG_STATE_NOTAVAILABLE);
914 }
915 EXPORT_SYMBOL_GPL(debug_object_assert_init);
916
917 /**
918 * debug_object_active_state - debug checks object usage state machine
919 * @addr: address of the object
920 * @descr: pointer to an object specific debug description structure
921 * @expect: expected state
922 * @next: state to move to if expected state is found
923 */
924 void
925 debug_object_active_state(void *addr, const struct debug_obj_descr *descr,
926 unsigned int expect, unsigned int next)
927 {
928 struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
929 struct debug_bucket *db;
930 struct debug_obj *obj;
931 unsigned long flags;
932
933 if (!debug_objects_enabled)
934 return;
935
936 db = get_bucket((unsigned long) addr);
937
938 raw_spin_lock_irqsave(&db->lock, flags);
939
940 obj = lookup_object(addr, db);
941 if (obj) {
942 switch (obj->state) {
943 case ODEBUG_STATE_ACTIVE:
944 if (obj->astate != expect)
945 break;
946 obj->astate = next;
947 raw_spin_unlock_irqrestore(&db->lock, flags);
948 return;
949 default:
950 break;
951 }
952 o = *obj;
953 }
954
955 raw_spin_unlock_irqrestore(&db->lock, flags);
956 debug_print_object(&o, "active_state");
957 }
958 EXPORT_SYMBOL_GPL(debug_object_active_state);
959
960 #ifdef CONFIG_DEBUG_OBJECTS_FREE
961 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
962 {
963 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
964 int cnt, objs_checked = 0;
965 struct debug_obj *obj, o;
966 struct debug_bucket *db;
967 struct hlist_node *tmp;
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
978 repeat:
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 o = *obj;
990 raw_spin_unlock_irqrestore(&db->lock, flags);
991 debug_print_object(&o, "free");
992 debug_object_fixup(o.descr->fixup_free, (void *)oaddr, o.state);
993 goto repeat;
994 default:
995 hlist_del(&obj->node);
996 __free_object(obj);
997 break;
998 }
999 }
1000 raw_spin_unlock_irqrestore(&db->lock, flags);
1001
1002 if (cnt > debug_objects_maxchain)
1003 debug_objects_maxchain = cnt;
1004
1005 objs_checked += cnt;
1006 }
1007
1008 if (objs_checked > debug_objects_maxchecked)
1009 debug_objects_maxchecked = objs_checked;
1010
1011 /* Schedule work to actually kmem_cache_free() objects */
1012 if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
1013 WRITE_ONCE(obj_freeing, true);
1014 schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
1015 }
1016 }
1017
1018 void debug_check_no_obj_freed(const void *address, unsigned long size)
1019 {
1020 if (debug_objects_enabled)
1021 __debug_check_no_obj_freed(address, size);
1022 }
1023 #endif
1024
1025 #ifdef CONFIG_DEBUG_FS
1026
1027 static int debug_stats_show(struct seq_file *m, void *v)
1028 {
1029 int cpu, obj_percpu_free = 0;
1030
1031 for_each_possible_cpu(cpu)
1032 obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu);
1033
1034 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
1035 seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked);
1036 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
1037 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
1038 seq_printf(m, "pool_free :%d\n", READ_ONCE(obj_pool_free) + obj_percpu_free);
1039 seq_printf(m, "pool_pcp_free :%d\n", obj_percpu_free);
1040 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
1041 seq_printf(m, "pool_used :%d\n", obj_pool_used - obj_percpu_free);
1042 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
1043 seq_printf(m, "on_free_list :%d\n", READ_ONCE(obj_nr_tofree));
1044 seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
1045 seq_printf(m, "objs_freed :%d\n", debug_objects_freed);
1046 return 0;
1047 }
1048 DEFINE_SHOW_ATTRIBUTE(debug_stats);
1049
1050 static int __init debug_objects_init_debugfs(void)
1051 {
1052 struct dentry *dbgdir;
1053
1054 if (!debug_objects_enabled)
1055 return 0;
1056
1057 dbgdir = debugfs_create_dir("debug_objects", NULL);
1058
1059 debugfs_create_file("stats", 0444, dbgdir, NULL, &debug_stats_fops);
1060
1061 return 0;
1062 }
1063 __initcall(debug_objects_init_debugfs);
1064
1065 #else
1066 static inline void debug_objects_init_debugfs(void) { }
1067 #endif
1068
1069 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
1070
1071 /* Random data structure for the self test */
1072 struct self_test {
1073 unsigned long dummy1[6];
1074 int static_init;
1075 unsigned long dummy2[3];
1076 };
1077
1078 static __initconst const struct debug_obj_descr descr_type_test;
1079
1080 static bool __init is_static_object(void *addr)
1081 {
1082 struct self_test *obj = addr;
1083
1084 return obj->static_init;
1085 }
1086
1087 /*
1088 * fixup_init is called when:
1089 * - an active object is initialized
1090 */
1091 static bool __init fixup_init(void *addr, enum debug_obj_state state)
1092 {
1093 struct self_test *obj = addr;
1094
1095 switch (state) {
1096 case ODEBUG_STATE_ACTIVE:
1097 debug_object_deactivate(obj, &descr_type_test);
1098 debug_object_init(obj, &descr_type_test);
1099 return true;
1100 default:
1101 return false;
1102 }
1103 }
1104
1105 /*
1106 * fixup_activate is called when:
1107 * - an active object is activated
1108 * - an unknown non-static object is activated
1109 */
1110 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
1111 {
1112 struct self_test *obj = addr;
1113
1114 switch (state) {
1115 case ODEBUG_STATE_NOTAVAILABLE:
1116 return true;
1117 case ODEBUG_STATE_ACTIVE:
1118 debug_object_deactivate(obj, &descr_type_test);
1119 debug_object_activate(obj, &descr_type_test);
1120 return true;
1121
1122 default:
1123 return false;
1124 }
1125 }
1126
1127 /*
1128 * fixup_destroy is called when:
1129 * - an active object is destroyed
1130 */
1131 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
1132 {
1133 struct self_test *obj = addr;
1134
1135 switch (state) {
1136 case ODEBUG_STATE_ACTIVE:
1137 debug_object_deactivate(obj, &descr_type_test);
1138 debug_object_destroy(obj, &descr_type_test);
1139 return true;
1140 default:
1141 return false;
1142 }
1143 }
1144
1145 /*
1146 * fixup_free is called when:
1147 * - an active object is freed
1148 */
1149 static bool __init fixup_free(void *addr, enum debug_obj_state state)
1150 {
1151 struct self_test *obj = addr;
1152
1153 switch (state) {
1154 case ODEBUG_STATE_ACTIVE:
1155 debug_object_deactivate(obj, &descr_type_test);
1156 debug_object_free(obj, &descr_type_test);
1157 return true;
1158 default:
1159 return false;
1160 }
1161 }
1162
1163 static int __init
1164 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
1165 {
1166 struct debug_bucket *db;
1167 struct debug_obj *obj;
1168 unsigned long flags;
1169 int res = -EINVAL;
1170
1171 db = get_bucket((unsigned long) addr);
1172
1173 raw_spin_lock_irqsave(&db->lock, flags);
1174
1175 obj = lookup_object(addr, db);
1176 if (!obj && state != ODEBUG_STATE_NONE) {
1177 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
1178 goto out;
1179 }
1180 if (obj && obj->state != state) {
1181 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
1182 obj->state, state);
1183 goto out;
1184 }
1185 if (fixups != debug_objects_fixups) {
1186 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
1187 fixups, debug_objects_fixups);
1188 goto out;
1189 }
1190 if (warnings != debug_objects_warnings) {
1191 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
1192 warnings, debug_objects_warnings);
1193 goto out;
1194 }
1195 res = 0;
1196 out:
1197 raw_spin_unlock_irqrestore(&db->lock, flags);
1198 if (res)
1199 debug_objects_enabled = 0;
1200 return res;
1201 }
1202
1203 static __initconst const struct debug_obj_descr descr_type_test = {
1204 .name = "selftest",
1205 .is_static_object = is_static_object,
1206 .fixup_init = fixup_init,
1207 .fixup_activate = fixup_activate,
1208 .fixup_destroy = fixup_destroy,
1209 .fixup_free = fixup_free,
1210 };
1211
1212 static __initdata struct self_test obj = { .static_init = 0 };
1213
1214 static void __init debug_objects_selftest(void)
1215 {
1216 int fixups, oldfixups, warnings, oldwarnings;
1217 unsigned long flags;
1218
1219 local_irq_save(flags);
1220
1221 fixups = oldfixups = debug_objects_fixups;
1222 warnings = oldwarnings = debug_objects_warnings;
1223 descr_test = &descr_type_test;
1224
1225 debug_object_init(&obj, &descr_type_test);
1226 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1227 goto out;
1228 debug_object_activate(&obj, &descr_type_test);
1229 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1230 goto out;
1231 debug_object_activate(&obj, &descr_type_test);
1232 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
1233 goto out;
1234 debug_object_deactivate(&obj, &descr_type_test);
1235 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1236 goto out;
1237 debug_object_destroy(&obj, &descr_type_test);
1238 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1239 goto out;
1240 debug_object_init(&obj, &descr_type_test);
1241 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1242 goto out;
1243 debug_object_activate(&obj, &descr_type_test);
1244 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1245 goto out;
1246 debug_object_deactivate(&obj, &descr_type_test);
1247 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1248 goto out;
1249 debug_object_free(&obj, &descr_type_test);
1250 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1251 goto out;
1252
1253 obj.static_init = 1;
1254 debug_object_activate(&obj, &descr_type_test);
1255 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1256 goto out;
1257 debug_object_init(&obj, &descr_type_test);
1258 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1259 goto out;
1260 debug_object_free(&obj, &descr_type_test);
1261 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1262 goto out;
1263
1264 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1265 debug_object_init(&obj, &descr_type_test);
1266 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1267 goto out;
1268 debug_object_activate(&obj, &descr_type_test);
1269 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1270 goto out;
1271 __debug_check_no_obj_freed(&obj, sizeof(obj));
1272 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1273 goto out;
1274 #endif
1275 pr_info("selftest passed\n");
1276
1277 out:
1278 debug_objects_fixups = oldfixups;
1279 debug_objects_warnings = oldwarnings;
1280 descr_test = NULL;
1281
1282 local_irq_restore(flags);
1283 }
1284 #else
1285 static inline void debug_objects_selftest(void) { }
1286 #endif
1287
1288 /*
1289 * Called during early boot to initialize the hash buckets and link
1290 * the static object pool objects into the poll list. After this call
1291 * the object tracker is fully operational.
1292 */
1293 void __init debug_objects_early_init(void)
1294 {
1295 int i;
1296
1297 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1298 raw_spin_lock_init(&obj_hash[i].lock);
1299
1300 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1301 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1302 }
1303
1304 /*
1305 * Convert the statically allocated objects to dynamic ones:
1306 */
1307 static int __init debug_objects_replace_static_objects(void)
1308 {
1309 struct debug_bucket *db = obj_hash;
1310 struct hlist_node *tmp;
1311 struct debug_obj *obj, *new;
1312 HLIST_HEAD(objects);
1313 int i, cnt = 0;
1314
1315 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1316 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1317 if (!obj)
1318 goto free;
1319 hlist_add_head(&obj->node, &objects);
1320 }
1321
1322 debug_objects_allocated += i;
1323
1324 /*
1325 * debug_objects_mem_init() is now called early that only one CPU is up
1326 * and interrupts have been disabled, so it is safe to replace the
1327 * active object references.
1328 */
1329
1330 /* Remove the statically allocated objects from the pool */
1331 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1332 hlist_del(&obj->node);
1333 /* Move the allocated objects to the pool */
1334 hlist_move_list(&objects, &obj_pool);
1335
1336 /* Replace the active object references */
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 /* copy object data */
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;
1353 free:
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 * Called after the kmem_caches are functional to setup a dedicated
1363 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1364 * prevents that the debug code is called on kmem_cache_free() for the
1365 * debug tracker objects to avoid recursive calls.
1366 */
1367 void __init debug_objects_mem_init(void)
1368 {
1369 int cpu, extras;
1370
1371 if (!debug_objects_enabled)
1372 return;
1373
1374 /*
1375 * Initialize the percpu object pools
1376 *
1377 * Initialization is not strictly necessary, but was done for
1378 * completeness.
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 return;
1393 } else
1394 debug_objects_selftest();
1395
1396 #ifdef CONFIG_HOTPLUG_CPU
1397 cpuhp_setup_state_nocalls(CPUHP_DEBUG_OBJ_DEAD, "object:offline", NULL,
1398 object_cpu_offline);
1399 #endif
1400
1401 /*
1402 * Increase the thresholds for allocating and freeing objects
1403 * according to the number of possible CPUs available in the system.
1404 */
1405 extras = num_possible_cpus() * ODEBUG_BATCH_SIZE;
1406 debug_objects_pool_size += extras;
1407 debug_objects_pool_min_level += extras;
1408 }
1409
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