xref: /linux/mm/slab.h (revision e8d780dcd957d80725ad5dd00bab53b856429bc0)
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 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 							/*
77 							 * If slab debugging is enabled then the
78 							 * frozen bit can be reused to indicate
79 							 * that the slab was corrupted
80 							 */
81 							unsigned frozen:1;
82 						};
83 					};
84 				};
85 #ifdef system_has_freelist_aba
86 				freelist_aba_t freelist_counter;
87 #endif
88 			};
89 		};
90 		struct rcu_head rcu_head;
91 	};
92 
93 	unsigned int __page_type;
94 	atomic_t __page_refcount;
95 #ifdef CONFIG_SLAB_OBJ_EXT
96 	unsigned long obj_exts;
97 #endif
98 };
99 
100 #define SLAB_MATCH(pg, sl)						\
101 	static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
102 SLAB_MATCH(flags, flags);
103 SLAB_MATCH(compound_head, slab_cache);	/* Ensure bit 0 is clear */
104 SLAB_MATCH(_refcount, __page_refcount);
105 #ifdef CONFIG_MEMCG
106 SLAB_MATCH(memcg_data, obj_exts);
107 #elif defined(CONFIG_SLAB_OBJ_EXT)
108 SLAB_MATCH(_unused_slab_obj_exts, obj_exts);
109 #endif
110 #undef SLAB_MATCH
111 static_assert(sizeof(struct slab) <= sizeof(struct page));
112 #if defined(system_has_freelist_aba)
113 static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t)));
114 #endif
115 
116 /**
117  * folio_slab - Converts from folio to slab.
118  * @folio: The folio.
119  *
120  * Currently struct slab is a different representation of a folio where
121  * folio_test_slab() is true.
122  *
123  * Return: The slab which contains this folio.
124  */
125 #define folio_slab(folio)	(_Generic((folio),			\
126 	const struct folio *:	(const struct slab *)(folio),		\
127 	struct folio *:		(struct slab *)(folio)))
128 
129 /**
130  * slab_folio - The folio allocated for a slab
131  * @s: The slab.
132  *
133  * Slabs are allocated as folios that contain the individual objects and are
134  * using some fields in the first struct page of the folio - those fields are
135  * now accessed by struct slab. It is occasionally necessary to convert back to
136  * a folio in order to communicate with the rest of the mm.  Please use this
137  * helper function instead of casting yourself, as the implementation may change
138  * in the future.
139  */
140 #define slab_folio(s)		(_Generic((s),				\
141 	const struct slab *:	(const struct folio *)s,		\
142 	struct slab *:		(struct folio *)s))
143 
144 /**
145  * page_slab - Converts from first struct page to slab.
146  * @p: The first (either head of compound or single) page of slab.
147  *
148  * A temporary wrapper to convert struct page to struct slab in situations where
149  * we know the page is the compound head, or single order-0 page.
150  *
151  * Long-term ideally everything would work with struct slab directly or go
152  * through folio to struct slab.
153  *
154  * Return: The slab which contains this page
155  */
156 #define page_slab(p)		(_Generic((p),				\
157 	const struct page *:	(const struct slab *)(p),		\
158 	struct page *:		(struct slab *)(p)))
159 
160 /**
161  * slab_page - The first struct page allocated for a slab
162  * @s: The slab.
163  *
164  * A convenience wrapper for converting slab to the first struct page of the
165  * underlying folio, to communicate with code not yet converted to folio or
166  * struct slab.
167  */
168 #define slab_page(s) folio_page(slab_folio(s), 0)
169 
slab_address(const struct slab * slab)170 static inline void *slab_address(const struct slab *slab)
171 {
172 	return folio_address(slab_folio(slab));
173 }
174 
slab_nid(const struct slab * slab)175 static inline int slab_nid(const struct slab *slab)
176 {
177 	return folio_nid(slab_folio(slab));
178 }
179 
slab_pgdat(const struct slab * slab)180 static inline pg_data_t *slab_pgdat(const struct slab *slab)
181 {
182 	return folio_pgdat(slab_folio(slab));
183 }
184 
virt_to_slab(const void * addr)185 static inline struct slab *virt_to_slab(const void *addr)
186 {
187 	struct folio *folio = virt_to_folio(addr);
188 
189 	if (!folio_test_slab(folio))
190 		return NULL;
191 
192 	return folio_slab(folio);
193 }
194 
slab_order(const struct slab * slab)195 static inline int slab_order(const struct slab *slab)
196 {
197 	return folio_order(slab_folio(slab));
198 }
199 
slab_size(const struct slab * slab)200 static inline size_t slab_size(const struct slab *slab)
201 {
202 	return PAGE_SIZE << slab_order(slab);
203 }
204 
205 #ifdef CONFIG_SLUB_CPU_PARTIAL
206 #define slub_percpu_partial(c)			((c)->partial)
207 
208 #define slub_set_percpu_partial(c, p)		\
209 ({						\
210 	slub_percpu_partial(c) = (p)->next;	\
211 })
212 
213 #define slub_percpu_partial_read_once(c)	READ_ONCE(slub_percpu_partial(c))
214 #else
215 #define slub_percpu_partial(c)			NULL
216 
217 #define slub_set_percpu_partial(c, p)
218 
219 #define slub_percpu_partial_read_once(c)	NULL
220 #endif // CONFIG_SLUB_CPU_PARTIAL
221 
222 /*
223  * Word size structure that can be atomically updated or read and that
224  * contains both the order and the number of objects that a slab of the
225  * given order would contain.
226  */
227 struct kmem_cache_order_objects {
228 	unsigned int x;
229 };
230 
231 /*
232  * Slab cache management.
233  */
234 struct kmem_cache {
235 #ifndef CONFIG_SLUB_TINY
236 	struct kmem_cache_cpu __percpu *cpu_slab;
237 #endif
238 	/* Used for retrieving partial slabs, etc. */
239 	slab_flags_t flags;
240 	unsigned long min_partial;
241 	unsigned int size;		/* Object size including metadata */
242 	unsigned int object_size;	/* Object size without metadata */
243 	struct reciprocal_value reciprocal_size;
244 	unsigned int offset;		/* Free pointer offset */
245 #ifdef CONFIG_SLUB_CPU_PARTIAL
246 	/* Number of per cpu partial objects to keep around */
247 	unsigned int cpu_partial;
248 	/* Number of per cpu partial slabs to keep around */
249 	unsigned int cpu_partial_slabs;
250 #endif
251 	struct kmem_cache_order_objects oo;
252 
253 	/* Allocation and freeing of slabs */
254 	struct kmem_cache_order_objects min;
255 	gfp_t allocflags;		/* gfp flags to use on each alloc */
256 	int refcount;			/* Refcount for slab cache destroy */
257 	void (*ctor)(void *object);	/* Object constructor */
258 	unsigned int inuse;		/* Offset to metadata */
259 	unsigned int align;		/* Alignment */
260 	unsigned int red_left_pad;	/* Left redzone padding size */
261 	const char *name;		/* Name (only for display!) */
262 	struct list_head list;		/* List of slab caches */
263 #ifdef CONFIG_SYSFS
264 	struct kobject kobj;		/* For sysfs */
265 #endif
266 #ifdef CONFIG_SLAB_FREELIST_HARDENED
267 	unsigned long random;
268 #endif
269 
270 #ifdef CONFIG_NUMA
271 	/*
272 	 * Defragmentation by allocating from a remote node.
273 	 */
274 	unsigned int remote_node_defrag_ratio;
275 #endif
276 
277 #ifdef CONFIG_SLAB_FREELIST_RANDOM
278 	unsigned int *random_seq;
279 #endif
280 
281 #ifdef CONFIG_KASAN_GENERIC
282 	struct kasan_cache kasan_info;
283 #endif
284 
285 #ifdef CONFIG_HARDENED_USERCOPY
286 	unsigned int useroffset;	/* Usercopy region offset */
287 	unsigned int usersize;		/* Usercopy region size */
288 #endif
289 
290 	struct kmem_cache_node *node[MAX_NUMNODES];
291 };
292 
293 #if defined(CONFIG_SYSFS) && !defined(CONFIG_SLUB_TINY)
294 #define SLAB_SUPPORTS_SYSFS 1
295 void sysfs_slab_unlink(struct kmem_cache *s);
296 void sysfs_slab_release(struct kmem_cache *s);
297 #else
sysfs_slab_unlink(struct kmem_cache * s)298 static inline void sysfs_slab_unlink(struct kmem_cache *s) { }
sysfs_slab_release(struct kmem_cache * s)299 static inline void sysfs_slab_release(struct kmem_cache *s) { }
300 #endif
301 
302 void *fixup_red_left(struct kmem_cache *s, void *p);
303 
nearest_obj(struct kmem_cache * cache,const struct slab * slab,void * x)304 static inline void *nearest_obj(struct kmem_cache *cache,
305 				const struct slab *slab, void *x)
306 {
307 	void *object = x - (x - slab_address(slab)) % cache->size;
308 	void *last_object = slab_address(slab) +
309 		(slab->objects - 1) * cache->size;
310 	void *result = (unlikely(object > last_object)) ? last_object : object;
311 
312 	result = fixup_red_left(cache, result);
313 	return result;
314 }
315 
316 /* Determine object index from a given position */
__obj_to_index(const struct kmem_cache * cache,void * addr,void * obj)317 static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
318 					  void *addr, void *obj)
319 {
320 	return reciprocal_divide(kasan_reset_tag(obj) - addr,
321 				 cache->reciprocal_size);
322 }
323 
obj_to_index(const struct kmem_cache * cache,const struct slab * slab,void * obj)324 static inline unsigned int obj_to_index(const struct kmem_cache *cache,
325 					const struct slab *slab, void *obj)
326 {
327 	if (is_kfence_address(obj))
328 		return 0;
329 	return __obj_to_index(cache, slab_address(slab), obj);
330 }
331 
objs_per_slab(const struct kmem_cache * cache,const struct slab * slab)332 static inline int objs_per_slab(const struct kmem_cache *cache,
333 				const struct slab *slab)
334 {
335 	return slab->objects;
336 }
337 
338 /*
339  * State of the slab allocator.
340  *
341  * This is used to describe the states of the allocator during bootup.
342  * Allocators use this to gradually bootstrap themselves. Most allocators
343  * have the problem that the structures used for managing slab caches are
344  * allocated from slab caches themselves.
345  */
346 enum slab_state {
347 	DOWN,			/* No slab functionality yet */
348 	PARTIAL,		/* SLUB: kmem_cache_node available */
349 	UP,			/* Slab caches usable but not all extras yet */
350 	FULL			/* Everything is working */
351 };
352 
353 extern enum slab_state slab_state;
354 
355 /* The slab cache mutex protects the management structures during changes */
356 extern struct mutex slab_mutex;
357 
358 /* The list of all slab caches on the system */
359 extern struct list_head slab_caches;
360 
361 /* The slab cache that manages slab cache information */
362 extern struct kmem_cache *kmem_cache;
363 
364 /* A table of kmalloc cache names and sizes */
365 extern const struct kmalloc_info_struct {
366 	const char *name[NR_KMALLOC_TYPES];
367 	unsigned int size;
368 } kmalloc_info[];
369 
370 /* Kmalloc array related functions */
371 void setup_kmalloc_cache_index_table(void);
372 void create_kmalloc_caches(void);
373 
374 extern u8 kmalloc_size_index[24];
375 
size_index_elem(unsigned int bytes)376 static inline unsigned int size_index_elem(unsigned int bytes)
377 {
378 	return (bytes - 1) / 8;
379 }
380 
381 /*
382  * Find the kmem_cache structure that serves a given size of
383  * allocation
384  *
385  * This assumes size is larger than zero and not larger than
386  * KMALLOC_MAX_CACHE_SIZE and the caller must check that.
387  */
388 static inline struct kmem_cache *
kmalloc_slab(size_t size,kmem_buckets * b,gfp_t flags,unsigned long caller)389 kmalloc_slab(size_t size, kmem_buckets *b, gfp_t flags, unsigned long caller)
390 {
391 	unsigned int index;
392 
393 	if (!b)
394 		b = &kmalloc_caches[kmalloc_type(flags, caller)];
395 	if (size <= 192)
396 		index = kmalloc_size_index[size_index_elem(size)];
397 	else
398 		index = fls(size - 1);
399 
400 	return (*b)[index];
401 }
402 
403 gfp_t kmalloc_fix_flags(gfp_t flags);
404 
405 /* Functions provided by the slab allocators */
406 int do_kmem_cache_create(struct kmem_cache *s, const char *name,
407 			 unsigned int size, struct kmem_cache_args *args,
408 			 slab_flags_t flags);
409 
410 void __init kmem_cache_init(void);
411 extern void create_boot_cache(struct kmem_cache *, const char *name,
412 			unsigned int size, slab_flags_t flags,
413 			unsigned int useroffset, unsigned int usersize);
414 
415 int slab_unmergeable(struct kmem_cache *s);
416 struct kmem_cache *find_mergeable(unsigned size, unsigned align,
417 		slab_flags_t flags, const char *name, void (*ctor)(void *));
418 struct kmem_cache *
419 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
420 		   slab_flags_t flags, void (*ctor)(void *));
421 
422 slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name);
423 
is_kmalloc_cache(struct kmem_cache * s)424 static inline bool is_kmalloc_cache(struct kmem_cache *s)
425 {
426 	return (s->flags & SLAB_KMALLOC);
427 }
428 
is_kmalloc_normal(struct kmem_cache * s)429 static inline bool is_kmalloc_normal(struct kmem_cache *s)
430 {
431 	if (!is_kmalloc_cache(s))
432 		return false;
433 	return !(s->flags & (SLAB_CACHE_DMA|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT));
434 }
435 
436 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
437 			 SLAB_CACHE_DMA32 | SLAB_PANIC | \
438 			 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS | \
439 			 SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
440 			 SLAB_TEMPORARY | SLAB_ACCOUNT | \
441 			 SLAB_NO_USER_FLAGS | SLAB_KMALLOC | SLAB_NO_MERGE)
442 
443 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
444 			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
445 
446 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS)
447 
448 bool __kmem_cache_empty(struct kmem_cache *);
449 int __kmem_cache_shutdown(struct kmem_cache *);
450 void __kmem_cache_release(struct kmem_cache *);
451 int __kmem_cache_shrink(struct kmem_cache *);
452 void slab_kmem_cache_release(struct kmem_cache *);
453 
454 struct seq_file;
455 struct file;
456 
457 struct slabinfo {
458 	unsigned long active_objs;
459 	unsigned long num_objs;
460 	unsigned long active_slabs;
461 	unsigned long num_slabs;
462 	unsigned long shared_avail;
463 	unsigned int limit;
464 	unsigned int batchcount;
465 	unsigned int shared;
466 	unsigned int objects_per_slab;
467 	unsigned int cache_order;
468 };
469 
470 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
471 
472 #ifdef CONFIG_SLUB_DEBUG
473 #ifdef CONFIG_SLUB_DEBUG_ON
474 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
475 #else
476 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
477 #endif
478 extern void print_tracking(struct kmem_cache *s, void *object);
479 long validate_slab_cache(struct kmem_cache *s);
__slub_debug_enabled(void)480 static inline bool __slub_debug_enabled(void)
481 {
482 	return static_branch_unlikely(&slub_debug_enabled);
483 }
484 #else
print_tracking(struct kmem_cache * s,void * object)485 static inline void print_tracking(struct kmem_cache *s, void *object)
486 {
487 }
__slub_debug_enabled(void)488 static inline bool __slub_debug_enabled(void)
489 {
490 	return false;
491 }
492 #endif
493 
494 /*
495  * Returns true if any of the specified slab_debug flags is enabled for the
496  * cache. Use only for flags parsed by setup_slub_debug() as it also enables
497  * the static key.
498  */
kmem_cache_debug_flags(struct kmem_cache * s,slab_flags_t flags)499 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
500 {
501 	if (IS_ENABLED(CONFIG_SLUB_DEBUG))
502 		VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
503 	if (__slub_debug_enabled())
504 		return s->flags & flags;
505 	return false;
506 }
507 
508 #if IS_ENABLED(CONFIG_SLUB_DEBUG) && IS_ENABLED(CONFIG_KUNIT)
509 bool slab_in_kunit_test(void);
510 #else
slab_in_kunit_test(void)511 static inline bool slab_in_kunit_test(void) { return false; }
512 #endif
513 
514 #ifdef CONFIG_SLAB_OBJ_EXT
515 
516 /*
517  * slab_obj_exts - get the pointer to the slab object extension vector
518  * associated with a slab.
519  * @slab: a pointer to the slab struct
520  *
521  * Returns a pointer to the object extension vector associated with the slab,
522  * or NULL if no such vector has been associated yet.
523  */
slab_obj_exts(struct slab * slab)524 static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
525 {
526 	unsigned long obj_exts = READ_ONCE(slab->obj_exts);
527 
528 #ifdef CONFIG_MEMCG
529 	VM_BUG_ON_PAGE(obj_exts && !(obj_exts & MEMCG_DATA_OBJEXTS),
530 							slab_page(slab));
531 	VM_BUG_ON_PAGE(obj_exts & MEMCG_DATA_KMEM, slab_page(slab));
532 #endif
533 	return (struct slabobj_ext *)(obj_exts & ~OBJEXTS_FLAGS_MASK);
534 }
535 
536 int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
537                         gfp_t gfp, bool new_slab);
538 
539 #else /* CONFIG_SLAB_OBJ_EXT */
540 
slab_obj_exts(struct slab * slab)541 static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
542 {
543 	return NULL;
544 }
545 
546 #endif /* CONFIG_SLAB_OBJ_EXT */
547 
cache_vmstat_idx(struct kmem_cache * s)548 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
549 {
550 	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
551 		NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
552 }
553 
554 #ifdef CONFIG_MEMCG
555 bool __memcg_slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
556 				  gfp_t flags, size_t size, void **p);
557 void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
558 			    void **p, int objects, struct slabobj_ext *obj_exts);
559 #endif
560 
561 void kvfree_rcu_cb(struct rcu_head *head);
562 
563 size_t __ksize(const void *objp);
564 
slab_ksize(const struct kmem_cache * s)565 static inline size_t slab_ksize(const struct kmem_cache *s)
566 {
567 #ifdef CONFIG_SLUB_DEBUG
568 	/*
569 	 * Debugging requires use of the padding between object
570 	 * and whatever may come after it.
571 	 */
572 	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
573 		return s->object_size;
574 #endif
575 	if (s->flags & SLAB_KASAN)
576 		return s->object_size;
577 	/*
578 	 * If we have the need to store the freelist pointer
579 	 * back there or track user information then we can
580 	 * only use the space before that information.
581 	 */
582 	if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
583 		return s->inuse;
584 	/*
585 	 * Else we can use all the padding etc for the allocation
586 	 */
587 	return s->size;
588 }
589 
590 #ifdef CONFIG_SLUB_DEBUG
591 void dump_unreclaimable_slab(void);
592 #else
dump_unreclaimable_slab(void)593 static inline void dump_unreclaimable_slab(void)
594 {
595 }
596 #endif
597 
598 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
599 
600 #ifdef CONFIG_SLAB_FREELIST_RANDOM
601 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
602 			gfp_t gfp);
603 void cache_random_seq_destroy(struct kmem_cache *cachep);
604 #else
cache_random_seq_create(struct kmem_cache * cachep,unsigned int count,gfp_t gfp)605 static inline int cache_random_seq_create(struct kmem_cache *cachep,
606 					unsigned int count, gfp_t gfp)
607 {
608 	return 0;
609 }
cache_random_seq_destroy(struct kmem_cache * cachep)610 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
611 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
612 
slab_want_init_on_alloc(gfp_t flags,struct kmem_cache * c)613 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
614 {
615 	if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
616 				&init_on_alloc)) {
617 		if (c->ctor)
618 			return false;
619 		if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
620 			return flags & __GFP_ZERO;
621 		return true;
622 	}
623 	return flags & __GFP_ZERO;
624 }
625 
slab_want_init_on_free(struct kmem_cache * c)626 static inline bool slab_want_init_on_free(struct kmem_cache *c)
627 {
628 	if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
629 				&init_on_free))
630 		return !(c->ctor ||
631 			 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
632 	return false;
633 }
634 
635 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
636 void debugfs_slab_release(struct kmem_cache *);
637 #else
debugfs_slab_release(struct kmem_cache * s)638 static inline void debugfs_slab_release(struct kmem_cache *s) { }
639 #endif
640 
641 #ifdef CONFIG_PRINTK
642 #define KS_ADDRS_COUNT 16
643 struct kmem_obj_info {
644 	void *kp_ptr;
645 	struct slab *kp_slab;
646 	void *kp_objp;
647 	unsigned long kp_data_offset;
648 	struct kmem_cache *kp_slab_cache;
649 	void *kp_ret;
650 	void *kp_stack[KS_ADDRS_COUNT];
651 	void *kp_free_stack[KS_ADDRS_COUNT];
652 };
653 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
654 #endif
655 
656 void __check_heap_object(const void *ptr, unsigned long n,
657 			 const struct slab *slab, bool to_user);
658 
slub_debug_orig_size(struct kmem_cache * s)659 static inline bool slub_debug_orig_size(struct kmem_cache *s)
660 {
661 	return (kmem_cache_debug_flags(s, SLAB_STORE_USER) &&
662 			(s->flags & SLAB_KMALLOC));
663 }
664 
665 #ifdef CONFIG_SLUB_DEBUG
666 void skip_orig_size_check(struct kmem_cache *s, const void *object);
667 #endif
668 
669 #endif /* MM_SLAB_H */
670