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  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef MM_SLAB_H
  3#define MM_SLAB_H
  4/*
  5 * Internal slab definitions
  6 */
  7
  8/* Reuses the bits in struct page */
  9struct slab {
 10	unsigned long __page_flags;
 11
 12#if defined(CONFIG_SLAB)
 13
 14	struct kmem_cache *slab_cache;
 15	union {
 16		struct {
 17			struct list_head slab_list;
 18			void *freelist;	/* array of free object indexes */
 19			void *s_mem;	/* first object */
 20		};
 21		struct rcu_head rcu_head;
 22	};
 23	unsigned int active;
 24
 25#elif defined(CONFIG_SLUB)
 26
 27	struct kmem_cache *slab_cache;
 28	union {
 29		struct {
 30			union {
 31				struct list_head slab_list;
 32#ifdef CONFIG_SLUB_CPU_PARTIAL
 33				struct {
 34					struct slab *next;
 35					int slabs;	/* Nr of slabs left */
 36				};
 37#endif
 38			};
 39			/* Double-word boundary */
 40			void *freelist;		/* first free object */
 41			union {
 42				unsigned long counters;
 43				struct {
 44					unsigned inuse:16;
 45					unsigned objects:15;
 46					unsigned frozen:1;
 47				};
 48			};
 49		};
 50		struct rcu_head rcu_head;
 51	};
 52	unsigned int __unused;
 53
 54#elif defined(CONFIG_SLOB)
 55
 56	struct list_head slab_list;
 57	void *__unused_1;
 58	void *freelist;		/* first free block */
 59	long units;
 60	unsigned int __unused_2;
 61
 62#else
 63#error "Unexpected slab allocator configured"
 64#endif
 65
 66	atomic_t __page_refcount;
 67#ifdef CONFIG_MEMCG
 68	unsigned long memcg_data;
 69#endif
 70};
 71
 72#define SLAB_MATCH(pg, sl)						\
 73	static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
 74SLAB_MATCH(flags, __page_flags);
 75#ifndef CONFIG_SLOB
 76SLAB_MATCH(compound_head, slab_cache);	/* Ensure bit 0 is clear */
 77#else
 78SLAB_MATCH(compound_head, slab_list);	/* Ensure bit 0 is clear */
 79#endif
 80SLAB_MATCH(_refcount, __page_refcount);
 81#ifdef CONFIG_MEMCG
 82SLAB_MATCH(memcg_data, memcg_data);
 83#endif
 84#undef SLAB_MATCH
 85static_assert(sizeof(struct slab) <= sizeof(struct page));
 86#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && defined(CONFIG_SLUB)
 87static_assert(IS_ALIGNED(offsetof(struct slab, freelist), 2*sizeof(void *)));
 88#endif
 89
 90/**
 91 * folio_slab - Converts from folio to slab.
 92 * @folio: The folio.
 93 *
 94 * Currently struct slab is a different representation of a folio where
 95 * folio_test_slab() is true.
 96 *
 97 * Return: The slab which contains this folio.
 98 */
 99#define folio_slab(folio)	(_Generic((folio),			\
100	const struct folio *:	(const struct slab *)(folio),		\
101	struct folio *:		(struct slab *)(folio)))
102
103/**
104 * slab_folio - The folio allocated for a slab
105 * @slab: The slab.
106 *
107 * Slabs are allocated as folios that contain the individual objects and are
108 * using some fields in the first struct page of the folio - those fields are
109 * now accessed by struct slab. It is occasionally necessary to convert back to
110 * a folio in order to communicate with the rest of the mm.  Please use this
111 * helper function instead of casting yourself, as the implementation may change
112 * in the future.
113 */
114#define slab_folio(s)		(_Generic((s),				\
115	const struct slab *:	(const struct folio *)s,		\
116	struct slab *:		(struct folio *)s))
117
118/**
119 * page_slab - Converts from first struct page to slab.
120 * @p: The first (either head of compound or single) page of slab.
121 *
122 * A temporary wrapper to convert struct page to struct slab in situations where
123 * we know the page is the compound head, or single order-0 page.
124 *
125 * Long-term ideally everything would work with struct slab directly or go
126 * through folio to struct slab.
127 *
128 * Return: The slab which contains this page
129 */
130#define page_slab(p)		(_Generic((p),				\
131	const struct page *:	(const struct slab *)(p),		\
132	struct page *:		(struct slab *)(p)))
133
134/**
135 * slab_page - The first struct page allocated for a slab
136 * @slab: The slab.
137 *
138 * A convenience wrapper for converting slab to the first struct page of the
139 * underlying folio, to communicate with code not yet converted to folio or
140 * struct slab.
141 */
142#define slab_page(s) folio_page(slab_folio(s), 0)
143
144/*
145 * If network-based swap is enabled, sl*b must keep track of whether pages
146 * were allocated from pfmemalloc reserves.
147 */
148static inline bool slab_test_pfmemalloc(const struct slab *slab)
149{
150	return folio_test_active((struct folio *)slab_folio(slab));
151}
152
153static inline void slab_set_pfmemalloc(struct slab *slab)
154{
155	folio_set_active(slab_folio(slab));
156}
157
158static inline void slab_clear_pfmemalloc(struct slab *slab)
159{
160	folio_clear_active(slab_folio(slab));
161}
162
163static inline void __slab_clear_pfmemalloc(struct slab *slab)
164{
165	__folio_clear_active(slab_folio(slab));
166}
167
168static inline void *slab_address(const struct slab *slab)
169{
170	return folio_address(slab_folio(slab));
171}
172
173static inline int slab_nid(const struct slab *slab)
174{
175	return folio_nid(slab_folio(slab));
176}
177
178static inline pg_data_t *slab_pgdat(const struct slab *slab)
179{
180	return folio_pgdat(slab_folio(slab));
181}
182
183static inline struct slab *virt_to_slab(const void *addr)
184{
185	struct folio *folio = virt_to_folio(addr);
186
187	if (!folio_test_slab(folio))
188		return NULL;
189
190	return folio_slab(folio);
191}
192
193static inline int slab_order(const struct slab *slab)
194{
195	return folio_order((struct folio *)slab_folio(slab));
196}
197
198static inline size_t slab_size(const struct slab *slab)
199{
200	return PAGE_SIZE << slab_order(slab);
201}
202
203#ifdef CONFIG_SLOB
204/*
205 * Common fields provided in kmem_cache by all slab allocators
206 * This struct is either used directly by the allocator (SLOB)
207 * or the allocator must include definitions for all fields
208 * provided in kmem_cache_common in their definition of kmem_cache.
209 *
210 * Once we can do anonymous structs (C11 standard) we could put a
211 * anonymous struct definition in these allocators so that the
212 * separate allocations in the kmem_cache structure of SLAB and
213 * SLUB is no longer needed.
214 */
215struct kmem_cache {
216	unsigned int object_size;/* The original size of the object */
217	unsigned int size;	/* The aligned/padded/added on size  */
218	unsigned int align;	/* Alignment as calculated */
219	slab_flags_t flags;	/* Active flags on the slab */
220	const char *name;	/* Slab name for sysfs */
221	int refcount;		/* Use counter */
222	void (*ctor)(void *);	/* Called on object slot creation */
223	struct list_head list;	/* List of all slab caches on the system */
224};
225
226#endif /* CONFIG_SLOB */
227
228#ifdef CONFIG_SLAB
229#include <linux/slab_def.h>
230#endif
231
232#ifdef CONFIG_SLUB
233#include <linux/slub_def.h>
234#endif
235
236#include <linux/memcontrol.h>
237#include <linux/fault-inject.h>
238#include <linux/kasan.h>
239#include <linux/kmemleak.h>
240#include <linux/random.h>
241#include <linux/sched/mm.h>
242#include <linux/list_lru.h>
243
244/*
245 * State of the slab allocator.
246 *
247 * This is used to describe the states of the allocator during bootup.
248 * Allocators use this to gradually bootstrap themselves. Most allocators
249 * have the problem that the structures used for managing slab caches are
250 * allocated from slab caches themselves.
251 */
252enum slab_state {
253	DOWN,			/* No slab functionality yet */
254	PARTIAL,		/* SLUB: kmem_cache_node available */
255	PARTIAL_NODE,		/* SLAB: kmalloc size for node struct available */
256	UP,			/* Slab caches usable but not all extras yet */
257	FULL			/* Everything is working */
258};
259
260extern enum slab_state slab_state;
261
262/* The slab cache mutex protects the management structures during changes */
263extern struct mutex slab_mutex;
264
265/* The list of all slab caches on the system */
266extern struct list_head slab_caches;
267
268/* The slab cache that manages slab cache information */
269extern struct kmem_cache *kmem_cache;
270
271/* A table of kmalloc cache names and sizes */
272extern const struct kmalloc_info_struct {
273	const char *name[NR_KMALLOC_TYPES];
274	unsigned int size;
275} kmalloc_info[];
276
277#ifndef CONFIG_SLOB
278/* Kmalloc array related functions */
279void setup_kmalloc_cache_index_table(void);
280void create_kmalloc_caches(slab_flags_t);
281
282/* Find the kmalloc slab corresponding for a certain size */
283struct kmem_cache *kmalloc_slab(size_t, gfp_t);
284
285void *__kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags,
286			      int node, size_t orig_size,
287			      unsigned long caller);
288void __kmem_cache_free(struct kmem_cache *s, void *x, unsigned long caller);
289#endif
290
291gfp_t kmalloc_fix_flags(gfp_t flags);
292
293/* Functions provided by the slab allocators */
294int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
295
296struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
297			slab_flags_t flags, unsigned int useroffset,
298			unsigned int usersize);
299extern void create_boot_cache(struct kmem_cache *, const char *name,
300			unsigned int size, slab_flags_t flags,
301			unsigned int useroffset, unsigned int usersize);
302
303int slab_unmergeable(struct kmem_cache *s);
304struct kmem_cache *find_mergeable(unsigned size, unsigned align,
305		slab_flags_t flags, const char *name, void (*ctor)(void *));
306#ifndef CONFIG_SLOB
307struct kmem_cache *
308__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
309		   slab_flags_t flags, void (*ctor)(void *));
310
311slab_flags_t kmem_cache_flags(unsigned int object_size,
312	slab_flags_t flags, const char *name);
313#else
314static inline struct kmem_cache *
315__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
316		   slab_flags_t flags, void (*ctor)(void *))
317{ return NULL; }
318
319static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
320	slab_flags_t flags, const char *name)
321{
322	return flags;
323}
324#endif
325
326
327/* Legal flag mask for kmem_cache_create(), for various configurations */
328#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
329			 SLAB_CACHE_DMA32 | SLAB_PANIC | \
330			 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
331
332#if defined(CONFIG_DEBUG_SLAB)
333#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
334#elif defined(CONFIG_SLUB_DEBUG)
335#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
336			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
337#else
338#define SLAB_DEBUG_FLAGS (0)
339#endif
340
341#if defined(CONFIG_SLAB)
342#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
343			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
344			  SLAB_ACCOUNT)
345#elif defined(CONFIG_SLUB)
346#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
347			  SLAB_TEMPORARY | SLAB_ACCOUNT | \
348			  SLAB_NO_USER_FLAGS | SLAB_KMALLOC)
349#else
350#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE)
351#endif
352
353/* Common flags available with current configuration */
354#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
355
356/* Common flags permitted for kmem_cache_create */
357#define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
358			      SLAB_RED_ZONE | \
359			      SLAB_POISON | \
360			      SLAB_STORE_USER | \
361			      SLAB_TRACE | \
362			      SLAB_CONSISTENCY_CHECKS | \
363			      SLAB_MEM_SPREAD | \
364			      SLAB_NOLEAKTRACE | \
365			      SLAB_RECLAIM_ACCOUNT | \
366			      SLAB_TEMPORARY | \
367			      SLAB_ACCOUNT | \
368			      SLAB_KMALLOC | \
369			      SLAB_NO_USER_FLAGS)
370
371bool __kmem_cache_empty(struct kmem_cache *);
372int __kmem_cache_shutdown(struct kmem_cache *);
373void __kmem_cache_release(struct kmem_cache *);
374int __kmem_cache_shrink(struct kmem_cache *);
375void slab_kmem_cache_release(struct kmem_cache *);
376
377struct seq_file;
378struct file;
379
380struct slabinfo {
381	unsigned long active_objs;
382	unsigned long num_objs;
383	unsigned long active_slabs;
384	unsigned long num_slabs;
385	unsigned long shared_avail;
386	unsigned int limit;
387	unsigned int batchcount;
388	unsigned int shared;
389	unsigned int objects_per_slab;
390	unsigned int cache_order;
391};
392
393void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
394void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
395ssize_t slabinfo_write(struct file *file, const char __user *buffer,
396		       size_t count, loff_t *ppos);
397
398static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
399{
400	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
401		NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
402}
403
404#ifdef CONFIG_SLUB_DEBUG
405#ifdef CONFIG_SLUB_DEBUG_ON
406DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
407#else
408DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
409#endif
410extern void print_tracking(struct kmem_cache *s, void *object);
411long validate_slab_cache(struct kmem_cache *s);
412static inline bool __slub_debug_enabled(void)
413{
414	return static_branch_unlikely(&slub_debug_enabled);
415}
416#else
417static inline void print_tracking(struct kmem_cache *s, void *object)
418{
419}
420static inline bool __slub_debug_enabled(void)
421{
422	return false;
423}
424#endif
425
426/*
427 * Returns true if any of the specified slub_debug flags is enabled for the
428 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
429 * the static key.
430 */
431static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
432{
433	if (IS_ENABLED(CONFIG_SLUB_DEBUG))
434		VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
435	if (__slub_debug_enabled())
436		return s->flags & flags;
437	return false;
438}
439
440#ifdef CONFIG_MEMCG_KMEM
441/*
442 * slab_objcgs - get the object cgroups vector associated with a slab
443 * @slab: a pointer to the slab struct
444 *
445 * Returns a pointer to the object cgroups vector associated with the slab,
446 * or NULL if no such vector has been associated yet.
447 */
448static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
449{
450	unsigned long memcg_data = READ_ONCE(slab->memcg_data);
451
452	VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS),
453							slab_page(slab));
454	VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
455
456	return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
457}
458
459int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
460				 gfp_t gfp, bool new_slab);
461void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
462		     enum node_stat_item idx, int nr);
463
464static inline void memcg_free_slab_cgroups(struct slab *slab)
465{
466	kfree(slab_objcgs(slab));
467	slab->memcg_data = 0;
468}
469
470static inline size_t obj_full_size(struct kmem_cache *s)
471{
472	/*
473	 * For each accounted object there is an extra space which is used
474	 * to store obj_cgroup membership. Charge it too.
475	 */
476	return s->size + sizeof(struct obj_cgroup *);
477}
478
479/*
480 * Returns false if the allocation should fail.
481 */
482static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
483					     struct list_lru *lru,
484					     struct obj_cgroup **objcgp,
485					     size_t objects, gfp_t flags)
486{
487	struct obj_cgroup *objcg;
488
489	if (!memcg_kmem_enabled())
490		return true;
491
492	if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
493		return true;
494
495	objcg = get_obj_cgroup_from_current();
496	if (!objcg)
497		return true;
498
499	if (lru) {
500		int ret;
501		struct mem_cgroup *memcg;
502
503		memcg = get_mem_cgroup_from_objcg(objcg);
504		ret = memcg_list_lru_alloc(memcg, lru, flags);
505		css_put(&memcg->css);
506
507		if (ret)
508			goto out;
509	}
510
511	if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
512		goto out;
513
514	*objcgp = objcg;
515	return true;
516out:
517	obj_cgroup_put(objcg);
518	return false;
519}
520
521static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
522					      struct obj_cgroup *objcg,
523					      gfp_t flags, size_t size,
524					      void **p)
525{
526	struct slab *slab;
527	unsigned long off;
528	size_t i;
529
530	if (!memcg_kmem_enabled() || !objcg)
531		return;
532
533	for (i = 0; i < size; i++) {
534		if (likely(p[i])) {
535			slab = virt_to_slab(p[i]);
536
537			if (!slab_objcgs(slab) &&
538			    memcg_alloc_slab_cgroups(slab, s, flags,
539							 false)) {
540				obj_cgroup_uncharge(objcg, obj_full_size(s));
541				continue;
542			}
543
544			off = obj_to_index(s, slab, p[i]);
545			obj_cgroup_get(objcg);
546			slab_objcgs(slab)[off] = objcg;
547			mod_objcg_state(objcg, slab_pgdat(slab),
548					cache_vmstat_idx(s), obj_full_size(s));
549		} else {
550			obj_cgroup_uncharge(objcg, obj_full_size(s));
551		}
552	}
553	obj_cgroup_put(objcg);
554}
555
556static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
557					void **p, int objects)
558{
559	struct obj_cgroup **objcgs;
560	int i;
561
562	if (!memcg_kmem_enabled())
563		return;
564
565	objcgs = slab_objcgs(slab);
566	if (!objcgs)
567		return;
568
569	for (i = 0; i < objects; i++) {
570		struct obj_cgroup *objcg;
571		unsigned int off;
572
573		off = obj_to_index(s, slab, p[i]);
574		objcg = objcgs[off];
575		if (!objcg)
576			continue;
577
578		objcgs[off] = NULL;
579		obj_cgroup_uncharge(objcg, obj_full_size(s));
580		mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
581				-obj_full_size(s));
582		obj_cgroup_put(objcg);
583	}
584}
585
586#else /* CONFIG_MEMCG_KMEM */
587static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
588{
589	return NULL;
590}
591
592static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
593{
594	return NULL;
595}
596
597static inline int memcg_alloc_slab_cgroups(struct slab *slab,
598					       struct kmem_cache *s, gfp_t gfp,
599					       bool new_slab)
600{
601	return 0;
602}
603
604static inline void memcg_free_slab_cgroups(struct slab *slab)
605{
606}
607
608static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
609					     struct list_lru *lru,
610					     struct obj_cgroup **objcgp,
611					     size_t objects, gfp_t flags)
612{
613	return true;
614}
615
616static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
617					      struct obj_cgroup *objcg,
618					      gfp_t flags, size_t size,
619					      void **p)
620{
621}
622
623static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
624					void **p, int objects)
625{
626}
627#endif /* CONFIG_MEMCG_KMEM */
628
629#ifndef CONFIG_SLOB
630static inline struct kmem_cache *virt_to_cache(const void *obj)
631{
632	struct slab *slab;
633
634	slab = virt_to_slab(obj);
635	if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
636					__func__))
637		return NULL;
638	return slab->slab_cache;
639}
640
641static __always_inline void account_slab(struct slab *slab, int order,
642					 struct kmem_cache *s, gfp_t gfp)
643{
644	if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT))
645		memcg_alloc_slab_cgroups(slab, s, gfp, true);
646
647	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
648			    PAGE_SIZE << order);
649}
650
651static __always_inline void unaccount_slab(struct slab *slab, int order,
652					   struct kmem_cache *s)
653{
654	if (memcg_kmem_enabled())
655		memcg_free_slab_cgroups(slab);
656
657	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
658			    -(PAGE_SIZE << order));
659}
660
661static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
662{
663	struct kmem_cache *cachep;
664
665	if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
666	    !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
667		return s;
668
669	cachep = virt_to_cache(x);
670	if (WARN(cachep && cachep != s,
671		  "%s: Wrong slab cache. %s but object is from %s\n",
672		  __func__, s->name, cachep->name))
673		print_tracking(cachep, x);
674	return cachep;
675}
676
677void free_large_kmalloc(struct folio *folio, void *object);
678
679#endif /* CONFIG_SLOB */
680
681size_t __ksize(const void *objp);
682
683static inline size_t slab_ksize(const struct kmem_cache *s)
684{
685#ifndef CONFIG_SLUB
686	return s->object_size;
687
688#else /* CONFIG_SLUB */
689# ifdef CONFIG_SLUB_DEBUG
690	/*
691	 * Debugging requires use of the padding between object
692	 * and whatever may come after it.
693	 */
694	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
695		return s->object_size;
696# endif
697	if (s->flags & SLAB_KASAN)
698		return s->object_size;
699	/*
700	 * If we have the need to store the freelist pointer
701	 * back there or track user information then we can
702	 * only use the space before that information.
703	 */
704	if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
705		return s->inuse;
706	/*
707	 * Else we can use all the padding etc for the allocation
708	 */
709	return s->size;
710#endif
711}
712
713static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
714						     struct list_lru *lru,
715						     struct obj_cgroup **objcgp,
716						     size_t size, gfp_t flags)
717{
718	flags &= gfp_allowed_mask;
719
720	might_alloc(flags);
721
722	if (should_failslab(s, flags))
723		return NULL;
724
725	if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
726		return NULL;
727
728	return s;
729}
730
731static inline void slab_post_alloc_hook(struct kmem_cache *s,
732					struct obj_cgroup *objcg, gfp_t flags,
733					size_t size, void **p, bool init,
734					unsigned int orig_size)
735{
736	unsigned int zero_size = s->object_size;
737	size_t i;
738
739	flags &= gfp_allowed_mask;
740
741	/*
742	 * For kmalloc object, the allocated memory size(object_size) is likely
743	 * larger than the requested size(orig_size). If redzone check is
744	 * enabled for the extra space, don't zero it, as it will be redzoned
745	 * soon. The redzone operation for this extra space could be seen as a
746	 * replacement of current poisoning under certain debug option, and
747	 * won't break other sanity checks.
748	 */
749	if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
750	    (s->flags & SLAB_KMALLOC))
751		zero_size = orig_size;
752
753	/*
754	 * As memory initialization might be integrated into KASAN,
755	 * kasan_slab_alloc and initialization memset must be
756	 * kept together to avoid discrepancies in behavior.
757	 *
758	 * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
759	 */
760	for (i = 0; i < size; i++) {
761		p[i] = kasan_slab_alloc(s, p[i], flags, init);
762		if (p[i] && init && !kasan_has_integrated_init())
763			memset(p[i], 0, zero_size);
764		kmemleak_alloc_recursive(p[i], s->object_size, 1,
765					 s->flags, flags);
766		kmsan_slab_alloc(s, p[i], flags);
767	}
768
769	memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
770}
771
772#ifndef CONFIG_SLOB
773/*
774 * The slab lists for all objects.
775 */
776struct kmem_cache_node {
777#ifdef CONFIG_SLAB
778	raw_spinlock_t list_lock;
779	struct list_head slabs_partial;	/* partial list first, better asm code */
780	struct list_head slabs_full;
781	struct list_head slabs_free;
782	unsigned long total_slabs;	/* length of all slab lists */
783	unsigned long free_slabs;	/* length of free slab list only */
784	unsigned long free_objects;
785	unsigned int free_limit;
786	unsigned int colour_next;	/* Per-node cache coloring */
787	struct array_cache *shared;	/* shared per node */
788	struct alien_cache **alien;	/* on other nodes */
789	unsigned long next_reap;	/* updated without locking */
790	int free_touched;		/* updated without locking */
791#endif
792
793#ifdef CONFIG_SLUB
794	spinlock_t list_lock;
795	unsigned long nr_partial;
796	struct list_head partial;
797#ifdef CONFIG_SLUB_DEBUG
798	atomic_long_t nr_slabs;
799	atomic_long_t total_objects;
800	struct list_head full;
801#endif
802#endif
803
804};
805
806static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
807{
808	return s->node[node];
809}
810
811/*
812 * Iterator over all nodes. The body will be executed for each node that has
813 * a kmem_cache_node structure allocated (which is true for all online nodes)
814 */
815#define for_each_kmem_cache_node(__s, __node, __n) \
816	for (__node = 0; __node < nr_node_ids; __node++) \
817		 if ((__n = get_node(__s, __node)))
818
819#endif
820
821#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
822void dump_unreclaimable_slab(void);
823#else
824static inline void dump_unreclaimable_slab(void)
825{
826}
827#endif
828
829void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
830
831#ifdef CONFIG_SLAB_FREELIST_RANDOM
832int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
833			gfp_t gfp);
834void cache_random_seq_destroy(struct kmem_cache *cachep);
835#else
836static inline int cache_random_seq_create(struct kmem_cache *cachep,
837					unsigned int count, gfp_t gfp)
838{
839	return 0;
840}
841static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
842#endif /* CONFIG_SLAB_FREELIST_RANDOM */
843
844static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
845{
846	if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
847				&init_on_alloc)) {
848		if (c->ctor)
849			return false;
850		if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
851			return flags & __GFP_ZERO;
852		return true;
853	}
854	return flags & __GFP_ZERO;
855}
856
857static inline bool slab_want_init_on_free(struct kmem_cache *c)
858{
859	if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
860				&init_on_free))
861		return !(c->ctor ||
862			 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
863	return false;
864}
865
866#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
867void debugfs_slab_release(struct kmem_cache *);
868#else
869static inline void debugfs_slab_release(struct kmem_cache *s) { }
870#endif
871
872#ifdef CONFIG_PRINTK
873#define KS_ADDRS_COUNT 16
874struct kmem_obj_info {
875	void *kp_ptr;
876	struct slab *kp_slab;
877	void *kp_objp;
878	unsigned long kp_data_offset;
879	struct kmem_cache *kp_slab_cache;
880	void *kp_ret;
881	void *kp_stack[KS_ADDRS_COUNT];
882	void *kp_free_stack[KS_ADDRS_COUNT];
883};
884void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
885#endif
886
887#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
888void __check_heap_object(const void *ptr, unsigned long n,
889			 const struct slab *slab, bool to_user);
890#else
891static inline
892void __check_heap_object(const void *ptr, unsigned long n,
893			 const struct slab *slab, bool to_user)
894{
895}
896#endif
897
898#ifdef CONFIG_SLUB_DEBUG
899void skip_orig_size_check(struct kmem_cache *s, const void *object);
900#endif
901
902#endif /* MM_SLAB_H */