xref: /linux/mm/slab.h (revision a3a02a52bcfcbcc4a637d4b68bf1bc391c9fad02)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef MM_SLAB_H
3 #define MM_SLAB_H
4 
5 #include <linux/reciprocal_div.h>
6 #include <linux/list_lru.h>
7 #include <linux/local_lock.h>
8 #include <linux/random.h>
9 #include <linux/kobject.h>
10 #include <linux/sched/mm.h>
11 #include <linux/memcontrol.h>
12 #include <linux/kfence.h>
13 #include <linux/kasan.h>
14 
15 /*
16  * Internal slab definitions
17  */
18 
19 #ifdef CONFIG_64BIT
20 # ifdef system_has_cmpxchg128
21 # define system_has_freelist_aba()	system_has_cmpxchg128()
22 # define try_cmpxchg_freelist		try_cmpxchg128
23 # endif
24 #define this_cpu_try_cmpxchg_freelist	this_cpu_try_cmpxchg128
25 typedef u128 freelist_full_t;
26 #else /* CONFIG_64BIT */
27 # ifdef system_has_cmpxchg64
28 # define system_has_freelist_aba()	system_has_cmpxchg64()
29 # define try_cmpxchg_freelist		try_cmpxchg64
30 # endif
31 #define this_cpu_try_cmpxchg_freelist	this_cpu_try_cmpxchg64
32 typedef u64 freelist_full_t;
33 #endif /* CONFIG_64BIT */
34 
35 #if defined(system_has_freelist_aba) && !defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
36 #undef system_has_freelist_aba
37 #endif
38 
39 /*
40  * Freelist pointer and counter to cmpxchg together, avoids the typical ABA
41  * problems with cmpxchg of just a pointer.
42  */
43 typedef union {
44 	struct {
45 		void *freelist;
46 		unsigned long counter;
47 	};
48 	freelist_full_t full;
49 } freelist_aba_t;
50 
51 /* Reuses the bits in struct page */
52 struct slab {
53 	unsigned long __page_flags;
54 
55 	struct kmem_cache *slab_cache;
56 	union {
57 		struct {
58 			union {
59 				struct list_head slab_list;
60 #ifdef CONFIG_SLUB_CPU_PARTIAL
61 				struct {
62 					struct slab *next;
63 					int slabs;	/* Nr of slabs left */
64 				};
65 #endif
66 			};
67 			/* Double-word boundary */
68 			union {
69 				struct {
70 					void *freelist;		/* first free object */
71 					union {
72 						unsigned long counters;
73 						struct {
74 							unsigned inuse:16;
75 							unsigned objects:15;
76 							unsigned frozen:1;
77 						};
78 					};
79 				};
80 #ifdef system_has_freelist_aba
81 				freelist_aba_t freelist_counter;
82 #endif
83 			};
84 		};
85 		struct rcu_head rcu_head;
86 	};
87 
88 	unsigned int __page_type;
89 	atomic_t __page_refcount;
90 #ifdef CONFIG_SLAB_OBJ_EXT
91 	unsigned long obj_exts;
92 #endif
93 };
94 
95 #define SLAB_MATCH(pg, sl)						\
96 	static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
97 SLAB_MATCH(flags, __page_flags);
98 SLAB_MATCH(compound_head, slab_cache);	/* Ensure bit 0 is clear */
99 SLAB_MATCH(_refcount, __page_refcount);
100 #ifdef CONFIG_MEMCG
101 SLAB_MATCH(memcg_data, obj_exts);
102 #elif defined(CONFIG_SLAB_OBJ_EXT)
103 SLAB_MATCH(_unused_slab_obj_exts, obj_exts);
104 #endif
105 #undef SLAB_MATCH
106 static_assert(sizeof(struct slab) <= sizeof(struct page));
107 #if defined(system_has_freelist_aba)
108 static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t)));
109 #endif
110 
111 /**
112  * folio_slab - Converts from folio to slab.
113  * @folio: The folio.
114  *
115  * Currently struct slab is a different representation of a folio where
116  * folio_test_slab() is true.
117  *
118  * Return: The slab which contains this folio.
119  */
120 #define folio_slab(folio)	(_Generic((folio),			\
121 	const struct folio *:	(const struct slab *)(folio),		\
122 	struct folio *:		(struct slab *)(folio)))
123 
124 /**
125  * slab_folio - The folio allocated for a slab
126  * @slab: The slab.
127  *
128  * Slabs are allocated as folios that contain the individual objects and are
129  * using some fields in the first struct page of the folio - those fields are
130  * now accessed by struct slab. It is occasionally necessary to convert back to
131  * a folio in order to communicate with the rest of the mm.  Please use this
132  * helper function instead of casting yourself, as the implementation may change
133  * in the future.
134  */
135 #define slab_folio(s)		(_Generic((s),				\
136 	const struct slab *:	(const struct folio *)s,		\
137 	struct slab *:		(struct folio *)s))
138 
139 /**
140  * page_slab - Converts from first struct page to slab.
141  * @p: The first (either head of compound or single) page of slab.
142  *
143  * A temporary wrapper to convert struct page to struct slab in situations where
144  * we know the page is the compound head, or single order-0 page.
145  *
146  * Long-term ideally everything would work with struct slab directly or go
147  * through folio to struct slab.
148  *
149  * Return: The slab which contains this page
150  */
151 #define page_slab(p)		(_Generic((p),				\
152 	const struct page *:	(const struct slab *)(p),		\
153 	struct page *:		(struct slab *)(p)))
154 
155 /**
156  * slab_page - The first struct page allocated for a slab
157  * @slab: The slab.
158  *
159  * A convenience wrapper for converting slab to the first struct page of the
160  * underlying folio, to communicate with code not yet converted to folio or
161  * struct slab.
162  */
163 #define slab_page(s) folio_page(slab_folio(s), 0)
164 
165 /*
166  * If network-based swap is enabled, sl*b must keep track of whether pages
167  * were allocated from pfmemalloc reserves.
168  */
169 static inline bool slab_test_pfmemalloc(const struct slab *slab)
170 {
171 	return folio_test_active(slab_folio(slab));
172 }
173 
174 static inline void slab_set_pfmemalloc(struct slab *slab)
175 {
176 	folio_set_active(slab_folio(slab));
177 }
178 
179 static inline void slab_clear_pfmemalloc(struct slab *slab)
180 {
181 	folio_clear_active(slab_folio(slab));
182 }
183 
184 static inline void __slab_clear_pfmemalloc(struct slab *slab)
185 {
186 	__folio_clear_active(slab_folio(slab));
187 }
188 
189 static inline void *slab_address(const struct slab *slab)
190 {
191 	return folio_address(slab_folio(slab));
192 }
193 
194 static inline int slab_nid(const struct slab *slab)
195 {
196 	return folio_nid(slab_folio(slab));
197 }
198 
199 static inline pg_data_t *slab_pgdat(const struct slab *slab)
200 {
201 	return folio_pgdat(slab_folio(slab));
202 }
203 
204 static inline struct slab *virt_to_slab(const void *addr)
205 {
206 	struct folio *folio = virt_to_folio(addr);
207 
208 	if (!folio_test_slab(folio))
209 		return NULL;
210 
211 	return folio_slab(folio);
212 }
213 
214 static inline int slab_order(const struct slab *slab)
215 {
216 	return folio_order(slab_folio(slab));
217 }
218 
219 static inline size_t slab_size(const struct slab *slab)
220 {
221 	return PAGE_SIZE << slab_order(slab);
222 }
223 
224 #ifdef CONFIG_SLUB_CPU_PARTIAL
225 #define slub_percpu_partial(c)			((c)->partial)
226 
227 #define slub_set_percpu_partial(c, p)		\
228 ({						\
229 	slub_percpu_partial(c) = (p)->next;	\
230 })
231 
232 #define slub_percpu_partial_read_once(c)	READ_ONCE(slub_percpu_partial(c))
233 #else
234 #define slub_percpu_partial(c)			NULL
235 
236 #define slub_set_percpu_partial(c, p)
237 
238 #define slub_percpu_partial_read_once(c)	NULL
239 #endif // CONFIG_SLUB_CPU_PARTIAL
240 
241 /*
242  * Word size structure that can be atomically updated or read and that
243  * contains both the order and the number of objects that a slab of the
244  * given order would contain.
245  */
246 struct kmem_cache_order_objects {
247 	unsigned int x;
248 };
249 
250 /*
251  * Slab cache management.
252  */
253 struct kmem_cache {
254 #ifndef CONFIG_SLUB_TINY
255 	struct kmem_cache_cpu __percpu *cpu_slab;
256 #endif
257 	/* Used for retrieving partial slabs, etc. */
258 	slab_flags_t flags;
259 	unsigned long min_partial;
260 	unsigned int size;		/* Object size including metadata */
261 	unsigned int object_size;	/* Object size without metadata */
262 	struct reciprocal_value reciprocal_size;
263 	unsigned int offset;		/* Free pointer offset */
264 #ifdef CONFIG_SLUB_CPU_PARTIAL
265 	/* Number of per cpu partial objects to keep around */
266 	unsigned int cpu_partial;
267 	/* Number of per cpu partial slabs to keep around */
268 	unsigned int cpu_partial_slabs;
269 #endif
270 	struct kmem_cache_order_objects oo;
271 
272 	/* Allocation and freeing of slabs */
273 	struct kmem_cache_order_objects min;
274 	gfp_t allocflags;		/* gfp flags to use on each alloc */
275 	int refcount;			/* Refcount for slab cache destroy */
276 	void (*ctor)(void *object);	/* Object constructor */
277 	unsigned int inuse;		/* Offset to metadata */
278 	unsigned int align;		/* Alignment */
279 	unsigned int red_left_pad;	/* Left redzone padding size */
280 	const char *name;		/* Name (only for display!) */
281 	struct list_head list;		/* List of slab caches */
282 #ifdef CONFIG_SYSFS
283 	struct kobject kobj;		/* For sysfs */
284 #endif
285 #ifdef CONFIG_SLAB_FREELIST_HARDENED
286 	unsigned long random;
287 #endif
288 
289 #ifdef CONFIG_NUMA
290 	/*
291 	 * Defragmentation by allocating from a remote node.
292 	 */
293 	unsigned int remote_node_defrag_ratio;
294 #endif
295 
296 #ifdef CONFIG_SLAB_FREELIST_RANDOM
297 	unsigned int *random_seq;
298 #endif
299 
300 #ifdef CONFIG_KASAN_GENERIC
301 	struct kasan_cache kasan_info;
302 #endif
303 
304 #ifdef CONFIG_HARDENED_USERCOPY
305 	unsigned int useroffset;	/* Usercopy region offset */
306 	unsigned int usersize;		/* Usercopy region size */
307 #endif
308 
309 	struct kmem_cache_node *node[MAX_NUMNODES];
310 };
311 
312 #if defined(CONFIG_SYSFS) && !defined(CONFIG_SLUB_TINY)
313 #define SLAB_SUPPORTS_SYSFS
314 void sysfs_slab_unlink(struct kmem_cache *s);
315 void sysfs_slab_release(struct kmem_cache *s);
316 #else
317 static inline void sysfs_slab_unlink(struct kmem_cache *s) { }
318 static inline void sysfs_slab_release(struct kmem_cache *s) { }
319 #endif
320 
321 void *fixup_red_left(struct kmem_cache *s, void *p);
322 
323 static inline void *nearest_obj(struct kmem_cache *cache,
324 				const struct slab *slab, void *x)
325 {
326 	void *object = x - (x - slab_address(slab)) % cache->size;
327 	void *last_object = slab_address(slab) +
328 		(slab->objects - 1) * cache->size;
329 	void *result = (unlikely(object > last_object)) ? last_object : object;
330 
331 	result = fixup_red_left(cache, result);
332 	return result;
333 }
334 
335 /* Determine object index from a given position */
336 static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
337 					  void *addr, void *obj)
338 {
339 	return reciprocal_divide(kasan_reset_tag(obj) - addr,
340 				 cache->reciprocal_size);
341 }
342 
343 static inline unsigned int obj_to_index(const struct kmem_cache *cache,
344 					const struct slab *slab, void *obj)
345 {
346 	if (is_kfence_address(obj))
347 		return 0;
348 	return __obj_to_index(cache, slab_address(slab), obj);
349 }
350 
351 static inline int objs_per_slab(const struct kmem_cache *cache,
352 				const struct slab *slab)
353 {
354 	return slab->objects;
355 }
356 
357 /*
358  * State of the slab allocator.
359  *
360  * This is used to describe the states of the allocator during bootup.
361  * Allocators use this to gradually bootstrap themselves. Most allocators
362  * have the problem that the structures used for managing slab caches are
363  * allocated from slab caches themselves.
364  */
365 enum slab_state {
366 	DOWN,			/* No slab functionality yet */
367 	PARTIAL,		/* SLUB: kmem_cache_node available */
368 	UP,			/* Slab caches usable but not all extras yet */
369 	FULL			/* Everything is working */
370 };
371 
372 extern enum slab_state slab_state;
373 
374 /* The slab cache mutex protects the management structures during changes */
375 extern struct mutex slab_mutex;
376 
377 /* The list of all slab caches on the system */
378 extern struct list_head slab_caches;
379 
380 /* The slab cache that manages slab cache information */
381 extern struct kmem_cache *kmem_cache;
382 
383 /* A table of kmalloc cache names and sizes */
384 extern const struct kmalloc_info_struct {
385 	const char *name[NR_KMALLOC_TYPES];
386 	unsigned int size;
387 } kmalloc_info[];
388 
389 /* Kmalloc array related functions */
390 void setup_kmalloc_cache_index_table(void);
391 void create_kmalloc_caches(void);
392 
393 extern u8 kmalloc_size_index[24];
394 
395 static inline unsigned int size_index_elem(unsigned int bytes)
396 {
397 	return (bytes - 1) / 8;
398 }
399 
400 /*
401  * Find the kmem_cache structure that serves a given size of
402  * allocation
403  *
404  * This assumes size is larger than zero and not larger than
405  * KMALLOC_MAX_CACHE_SIZE and the caller must check that.
406  */
407 static inline struct kmem_cache *
408 kmalloc_slab(size_t size, kmem_buckets *b, gfp_t flags, unsigned long caller)
409 {
410 	unsigned int index;
411 
412 	if (!b)
413 		b = &kmalloc_caches[kmalloc_type(flags, caller)];
414 	if (size <= 192)
415 		index = kmalloc_size_index[size_index_elem(size)];
416 	else
417 		index = fls(size - 1);
418 
419 	return (*b)[index];
420 }
421 
422 gfp_t kmalloc_fix_flags(gfp_t flags);
423 
424 /* Functions provided by the slab allocators */
425 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
426 
427 void __init kmem_cache_init(void);
428 extern void create_boot_cache(struct kmem_cache *, const char *name,
429 			unsigned int size, slab_flags_t flags,
430 			unsigned int useroffset, unsigned int usersize);
431 
432 int slab_unmergeable(struct kmem_cache *s);
433 struct kmem_cache *find_mergeable(unsigned size, unsigned align,
434 		slab_flags_t flags, const char *name, void (*ctor)(void *));
435 struct kmem_cache *
436 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
437 		   slab_flags_t flags, void (*ctor)(void *));
438 
439 slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name);
440 
441 static inline bool is_kmalloc_cache(struct kmem_cache *s)
442 {
443 	return (s->flags & SLAB_KMALLOC);
444 }
445 
446 /* Legal flag mask for kmem_cache_create(), for various configurations */
447 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
448 			 SLAB_CACHE_DMA32 | SLAB_PANIC | \
449 			 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
450 
451 #ifdef CONFIG_SLUB_DEBUG
452 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
453 			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
454 #else
455 #define SLAB_DEBUG_FLAGS (0)
456 #endif
457 
458 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
459 			  SLAB_TEMPORARY | SLAB_ACCOUNT | \
460 			  SLAB_NO_USER_FLAGS | SLAB_KMALLOC | SLAB_NO_MERGE)
461 
462 /* Common flags available with current configuration */
463 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
464 
465 /* Common flags permitted for kmem_cache_create */
466 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
467 			      SLAB_RED_ZONE | \
468 			      SLAB_POISON | \
469 			      SLAB_STORE_USER | \
470 			      SLAB_TRACE | \
471 			      SLAB_CONSISTENCY_CHECKS | \
472 			      SLAB_NOLEAKTRACE | \
473 			      SLAB_RECLAIM_ACCOUNT | \
474 			      SLAB_TEMPORARY | \
475 			      SLAB_ACCOUNT | \
476 			      SLAB_KMALLOC | \
477 			      SLAB_NO_MERGE | \
478 			      SLAB_NO_USER_FLAGS)
479 
480 bool __kmem_cache_empty(struct kmem_cache *);
481 int __kmem_cache_shutdown(struct kmem_cache *);
482 void __kmem_cache_release(struct kmem_cache *);
483 int __kmem_cache_shrink(struct kmem_cache *);
484 void slab_kmem_cache_release(struct kmem_cache *);
485 
486 struct seq_file;
487 struct file;
488 
489 struct slabinfo {
490 	unsigned long active_objs;
491 	unsigned long num_objs;
492 	unsigned long active_slabs;
493 	unsigned long num_slabs;
494 	unsigned long shared_avail;
495 	unsigned int limit;
496 	unsigned int batchcount;
497 	unsigned int shared;
498 	unsigned int objects_per_slab;
499 	unsigned int cache_order;
500 };
501 
502 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
503 
504 #ifdef CONFIG_SLUB_DEBUG
505 #ifdef CONFIG_SLUB_DEBUG_ON
506 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
507 #else
508 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
509 #endif
510 extern void print_tracking(struct kmem_cache *s, void *object);
511 long validate_slab_cache(struct kmem_cache *s);
512 static inline bool __slub_debug_enabled(void)
513 {
514 	return static_branch_unlikely(&slub_debug_enabled);
515 }
516 #else
517 static inline void print_tracking(struct kmem_cache *s, void *object)
518 {
519 }
520 static inline bool __slub_debug_enabled(void)
521 {
522 	return false;
523 }
524 #endif
525 
526 /*
527  * Returns true if any of the specified slab_debug flags is enabled for the
528  * cache. Use only for flags parsed by setup_slub_debug() as it also enables
529  * the static key.
530  */
531 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
532 {
533 	if (IS_ENABLED(CONFIG_SLUB_DEBUG))
534 		VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
535 	if (__slub_debug_enabled())
536 		return s->flags & flags;
537 	return false;
538 }
539 
540 #ifdef CONFIG_SLAB_OBJ_EXT
541 
542 /*
543  * slab_obj_exts - get the pointer to the slab object extension vector
544  * associated with a slab.
545  * @slab: a pointer to the slab struct
546  *
547  * Returns a pointer to the object extension vector associated with the slab,
548  * or NULL if no such vector has been associated yet.
549  */
550 static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
551 {
552 	unsigned long obj_exts = READ_ONCE(slab->obj_exts);
553 
554 #ifdef CONFIG_MEMCG
555 	VM_BUG_ON_PAGE(obj_exts && !(obj_exts & MEMCG_DATA_OBJEXTS),
556 							slab_page(slab));
557 	VM_BUG_ON_PAGE(obj_exts & MEMCG_DATA_KMEM, slab_page(slab));
558 #endif
559 	return (struct slabobj_ext *)(obj_exts & ~OBJEXTS_FLAGS_MASK);
560 }
561 
562 int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
563                         gfp_t gfp, bool new_slab);
564 
565 #else /* CONFIG_SLAB_OBJ_EXT */
566 
567 static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
568 {
569 	return NULL;
570 }
571 
572 #endif /* CONFIG_SLAB_OBJ_EXT */
573 
574 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
575 {
576 	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
577 		NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
578 }
579 
580 #ifdef CONFIG_MEMCG
581 bool __memcg_slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
582 				  gfp_t flags, size_t size, void **p);
583 void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
584 			    void **p, int objects, struct slabobj_ext *obj_exts);
585 #endif
586 
587 size_t __ksize(const void *objp);
588 
589 static inline size_t slab_ksize(const struct kmem_cache *s)
590 {
591 #ifdef CONFIG_SLUB_DEBUG
592 	/*
593 	 * Debugging requires use of the padding between object
594 	 * and whatever may come after it.
595 	 */
596 	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
597 		return s->object_size;
598 #endif
599 	if (s->flags & SLAB_KASAN)
600 		return s->object_size;
601 	/*
602 	 * If we have the need to store the freelist pointer
603 	 * back there or track user information then we can
604 	 * only use the space before that information.
605 	 */
606 	if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
607 		return s->inuse;
608 	/*
609 	 * Else we can use all the padding etc for the allocation
610 	 */
611 	return s->size;
612 }
613 
614 #ifdef CONFIG_SLUB_DEBUG
615 void dump_unreclaimable_slab(void);
616 #else
617 static inline void dump_unreclaimable_slab(void)
618 {
619 }
620 #endif
621 
622 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
623 
624 #ifdef CONFIG_SLAB_FREELIST_RANDOM
625 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
626 			gfp_t gfp);
627 void cache_random_seq_destroy(struct kmem_cache *cachep);
628 #else
629 static inline int cache_random_seq_create(struct kmem_cache *cachep,
630 					unsigned int count, gfp_t gfp)
631 {
632 	return 0;
633 }
634 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
635 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
636 
637 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
638 {
639 	if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
640 				&init_on_alloc)) {
641 		if (c->ctor)
642 			return false;
643 		if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
644 			return flags & __GFP_ZERO;
645 		return true;
646 	}
647 	return flags & __GFP_ZERO;
648 }
649 
650 static inline bool slab_want_init_on_free(struct kmem_cache *c)
651 {
652 	if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
653 				&init_on_free))
654 		return !(c->ctor ||
655 			 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
656 	return false;
657 }
658 
659 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
660 void debugfs_slab_release(struct kmem_cache *);
661 #else
662 static inline void debugfs_slab_release(struct kmem_cache *s) { }
663 #endif
664 
665 #ifdef CONFIG_PRINTK
666 #define KS_ADDRS_COUNT 16
667 struct kmem_obj_info {
668 	void *kp_ptr;
669 	struct slab *kp_slab;
670 	void *kp_objp;
671 	unsigned long kp_data_offset;
672 	struct kmem_cache *kp_slab_cache;
673 	void *kp_ret;
674 	void *kp_stack[KS_ADDRS_COUNT];
675 	void *kp_free_stack[KS_ADDRS_COUNT];
676 };
677 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
678 #endif
679 
680 void __check_heap_object(const void *ptr, unsigned long n,
681 			 const struct slab *slab, bool to_user);
682 
683 #ifdef CONFIG_SLUB_DEBUG
684 void skip_orig_size_check(struct kmem_cache *s, const void *object);
685 #endif
686 
687 #endif /* MM_SLAB_H */
688