xref: /linux/mm/slab.h (revision 52990390f91c1c39ca742fc8f390b29891d95127)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef MM_SLAB_H
3 #define MM_SLAB_H
4 /*
5  * Internal slab definitions
6  */
7 void __init kmem_cache_init(void);
8 
9 /* Reuses the bits in struct page */
10 struct slab {
11 	unsigned long __page_flags;
12 
13 #if defined(CONFIG_SLAB)
14 
15 	struct kmem_cache *slab_cache;
16 	union {
17 		struct {
18 			struct list_head slab_list;
19 			void *freelist;	/* array of free object indexes */
20 			void *s_mem;	/* first object */
21 		};
22 		struct rcu_head rcu_head;
23 	};
24 	unsigned int active;
25 
26 #elif defined(CONFIG_SLUB)
27 
28 	struct kmem_cache *slab_cache;
29 	union {
30 		struct {
31 			union {
32 				struct list_head slab_list;
33 #ifdef CONFIG_SLUB_CPU_PARTIAL
34 				struct {
35 					struct slab *next;
36 					int slabs;	/* Nr of slabs left */
37 				};
38 #endif
39 			};
40 			/* Double-word boundary */
41 			void *freelist;		/* first free object */
42 			union {
43 				unsigned long counters;
44 				struct {
45 					unsigned inuse:16;
46 					unsigned objects:15;
47 					unsigned frozen:1;
48 				};
49 			};
50 		};
51 		struct rcu_head rcu_head;
52 	};
53 	unsigned int __unused;
54 
55 #else
56 #error "Unexpected slab allocator configured"
57 #endif
58 
59 	atomic_t __page_refcount;
60 #ifdef CONFIG_MEMCG
61 	unsigned long memcg_data;
62 #endif
63 };
64 
65 #define SLAB_MATCH(pg, sl)						\
66 	static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
67 SLAB_MATCH(flags, __page_flags);
68 SLAB_MATCH(compound_head, slab_cache);	/* Ensure bit 0 is clear */
69 SLAB_MATCH(_refcount, __page_refcount);
70 #ifdef CONFIG_MEMCG
71 SLAB_MATCH(memcg_data, memcg_data);
72 #endif
73 #undef SLAB_MATCH
74 static_assert(sizeof(struct slab) <= sizeof(struct page));
75 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && defined(CONFIG_SLUB)
76 static_assert(IS_ALIGNED(offsetof(struct slab, freelist), 2*sizeof(void *)));
77 #endif
78 
79 /**
80  * folio_slab - Converts from folio to slab.
81  * @folio: The folio.
82  *
83  * Currently struct slab is a different representation of a folio where
84  * folio_test_slab() is true.
85  *
86  * Return: The slab which contains this folio.
87  */
88 #define folio_slab(folio)	(_Generic((folio),			\
89 	const struct folio *:	(const struct slab *)(folio),		\
90 	struct folio *:		(struct slab *)(folio)))
91 
92 /**
93  * slab_folio - The folio allocated for a slab
94  * @slab: The slab.
95  *
96  * Slabs are allocated as folios that contain the individual objects and are
97  * using some fields in the first struct page of the folio - those fields are
98  * now accessed by struct slab. It is occasionally necessary to convert back to
99  * a folio in order to communicate with the rest of the mm.  Please use this
100  * helper function instead of casting yourself, as the implementation may change
101  * in the future.
102  */
103 #define slab_folio(s)		(_Generic((s),				\
104 	const struct slab *:	(const struct folio *)s,		\
105 	struct slab *:		(struct folio *)s))
106 
107 /**
108  * page_slab - Converts from first struct page to slab.
109  * @p: The first (either head of compound or single) page of slab.
110  *
111  * A temporary wrapper to convert struct page to struct slab in situations where
112  * we know the page is the compound head, or single order-0 page.
113  *
114  * Long-term ideally everything would work with struct slab directly or go
115  * through folio to struct slab.
116  *
117  * Return: The slab which contains this page
118  */
119 #define page_slab(p)		(_Generic((p),				\
120 	const struct page *:	(const struct slab *)(p),		\
121 	struct page *:		(struct slab *)(p)))
122 
123 /**
124  * slab_page - The first struct page allocated for a slab
125  * @slab: The slab.
126  *
127  * A convenience wrapper for converting slab to the first struct page of the
128  * underlying folio, to communicate with code not yet converted to folio or
129  * struct slab.
130  */
131 #define slab_page(s) folio_page(slab_folio(s), 0)
132 
133 /*
134  * If network-based swap is enabled, sl*b must keep track of whether pages
135  * were allocated from pfmemalloc reserves.
136  */
137 static inline bool slab_test_pfmemalloc(const struct slab *slab)
138 {
139 	return folio_test_active((struct folio *)slab_folio(slab));
140 }
141 
142 static inline void slab_set_pfmemalloc(struct slab *slab)
143 {
144 	folio_set_active(slab_folio(slab));
145 }
146 
147 static inline void slab_clear_pfmemalloc(struct slab *slab)
148 {
149 	folio_clear_active(slab_folio(slab));
150 }
151 
152 static inline void __slab_clear_pfmemalloc(struct slab *slab)
153 {
154 	__folio_clear_active(slab_folio(slab));
155 }
156 
157 static inline void *slab_address(const struct slab *slab)
158 {
159 	return folio_address(slab_folio(slab));
160 }
161 
162 static inline int slab_nid(const struct slab *slab)
163 {
164 	return folio_nid(slab_folio(slab));
165 }
166 
167 static inline pg_data_t *slab_pgdat(const struct slab *slab)
168 {
169 	return folio_pgdat(slab_folio(slab));
170 }
171 
172 static inline struct slab *virt_to_slab(const void *addr)
173 {
174 	struct folio *folio = virt_to_folio(addr);
175 
176 	if (!folio_test_slab(folio))
177 		return NULL;
178 
179 	return folio_slab(folio);
180 }
181 
182 static inline int slab_order(const struct slab *slab)
183 {
184 	return folio_order((struct folio *)slab_folio(slab));
185 }
186 
187 static inline size_t slab_size(const struct slab *slab)
188 {
189 	return PAGE_SIZE << slab_order(slab);
190 }
191 
192 #ifdef CONFIG_SLAB
193 #include <linux/slab_def.h>
194 #endif
195 
196 #ifdef CONFIG_SLUB
197 #include <linux/slub_def.h>
198 #endif
199 
200 #include <linux/memcontrol.h>
201 #include <linux/fault-inject.h>
202 #include <linux/kasan.h>
203 #include <linux/kmemleak.h>
204 #include <linux/random.h>
205 #include <linux/sched/mm.h>
206 #include <linux/list_lru.h>
207 
208 /*
209  * State of the slab allocator.
210  *
211  * This is used to describe the states of the allocator during bootup.
212  * Allocators use this to gradually bootstrap themselves. Most allocators
213  * have the problem that the structures used for managing slab caches are
214  * allocated from slab caches themselves.
215  */
216 enum slab_state {
217 	DOWN,			/* No slab functionality yet */
218 	PARTIAL,		/* SLUB: kmem_cache_node available */
219 	PARTIAL_NODE,		/* SLAB: kmalloc size for node struct available */
220 	UP,			/* Slab caches usable but not all extras yet */
221 	FULL			/* Everything is working */
222 };
223 
224 extern enum slab_state slab_state;
225 
226 /* The slab cache mutex protects the management structures during changes */
227 extern struct mutex slab_mutex;
228 
229 /* The list of all slab caches on the system */
230 extern struct list_head slab_caches;
231 
232 /* The slab cache that manages slab cache information */
233 extern struct kmem_cache *kmem_cache;
234 
235 /* A table of kmalloc cache names and sizes */
236 extern const struct kmalloc_info_struct {
237 	const char *name[NR_KMALLOC_TYPES];
238 	unsigned int size;
239 } kmalloc_info[];
240 
241 /* Kmalloc array related functions */
242 void setup_kmalloc_cache_index_table(void);
243 void create_kmalloc_caches(slab_flags_t);
244 
245 /* Find the kmalloc slab corresponding for a certain size */
246 struct kmem_cache *kmalloc_slab(size_t, gfp_t);
247 
248 void *__kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags,
249 			      int node, size_t orig_size,
250 			      unsigned long caller);
251 void __kmem_cache_free(struct kmem_cache *s, void *x, unsigned long caller);
252 
253 gfp_t kmalloc_fix_flags(gfp_t flags);
254 
255 /* Functions provided by the slab allocators */
256 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
257 
258 struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
259 			slab_flags_t flags, unsigned int useroffset,
260 			unsigned int usersize);
261 extern void create_boot_cache(struct kmem_cache *, const char *name,
262 			unsigned int size, slab_flags_t flags,
263 			unsigned int useroffset, unsigned int usersize);
264 
265 int slab_unmergeable(struct kmem_cache *s);
266 struct kmem_cache *find_mergeable(unsigned size, unsigned align,
267 		slab_flags_t flags, const char *name, void (*ctor)(void *));
268 struct kmem_cache *
269 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
270 		   slab_flags_t flags, void (*ctor)(void *));
271 
272 slab_flags_t kmem_cache_flags(unsigned int object_size,
273 	slab_flags_t flags, const char *name);
274 
275 static inline bool is_kmalloc_cache(struct kmem_cache *s)
276 {
277 	return (s->flags & SLAB_KMALLOC);
278 }
279 
280 /* Legal flag mask for kmem_cache_create(), for various configurations */
281 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
282 			 SLAB_CACHE_DMA32 | SLAB_PANIC | \
283 			 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
284 
285 #if defined(CONFIG_DEBUG_SLAB)
286 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
287 #elif defined(CONFIG_SLUB_DEBUG)
288 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
289 			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
290 #else
291 #define SLAB_DEBUG_FLAGS (0)
292 #endif
293 
294 #if defined(CONFIG_SLAB)
295 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
296 			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
297 			  SLAB_ACCOUNT)
298 #elif defined(CONFIG_SLUB)
299 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
300 			  SLAB_TEMPORARY | SLAB_ACCOUNT | \
301 			  SLAB_NO_USER_FLAGS | SLAB_KMALLOC)
302 #else
303 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE)
304 #endif
305 
306 /* Common flags available with current configuration */
307 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
308 
309 /* Common flags permitted for kmem_cache_create */
310 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
311 			      SLAB_RED_ZONE | \
312 			      SLAB_POISON | \
313 			      SLAB_STORE_USER | \
314 			      SLAB_TRACE | \
315 			      SLAB_CONSISTENCY_CHECKS | \
316 			      SLAB_MEM_SPREAD | \
317 			      SLAB_NOLEAKTRACE | \
318 			      SLAB_RECLAIM_ACCOUNT | \
319 			      SLAB_TEMPORARY | \
320 			      SLAB_ACCOUNT | \
321 			      SLAB_KMALLOC | \
322 			      SLAB_NO_USER_FLAGS)
323 
324 bool __kmem_cache_empty(struct kmem_cache *);
325 int __kmem_cache_shutdown(struct kmem_cache *);
326 void __kmem_cache_release(struct kmem_cache *);
327 int __kmem_cache_shrink(struct kmem_cache *);
328 void slab_kmem_cache_release(struct kmem_cache *);
329 
330 struct seq_file;
331 struct file;
332 
333 struct slabinfo {
334 	unsigned long active_objs;
335 	unsigned long num_objs;
336 	unsigned long active_slabs;
337 	unsigned long num_slabs;
338 	unsigned long shared_avail;
339 	unsigned int limit;
340 	unsigned int batchcount;
341 	unsigned int shared;
342 	unsigned int objects_per_slab;
343 	unsigned int cache_order;
344 };
345 
346 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
347 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
348 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
349 		       size_t count, loff_t *ppos);
350 
351 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
352 {
353 	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
354 		NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
355 }
356 
357 #ifdef CONFIG_SLUB_DEBUG
358 #ifdef CONFIG_SLUB_DEBUG_ON
359 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
360 #else
361 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
362 #endif
363 extern void print_tracking(struct kmem_cache *s, void *object);
364 long validate_slab_cache(struct kmem_cache *s);
365 static inline bool __slub_debug_enabled(void)
366 {
367 	return static_branch_unlikely(&slub_debug_enabled);
368 }
369 #else
370 static inline void print_tracking(struct kmem_cache *s, void *object)
371 {
372 }
373 static inline bool __slub_debug_enabled(void)
374 {
375 	return false;
376 }
377 #endif
378 
379 /*
380  * Returns true if any of the specified slub_debug flags is enabled for the
381  * cache. Use only for flags parsed by setup_slub_debug() as it also enables
382  * the static key.
383  */
384 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
385 {
386 	if (IS_ENABLED(CONFIG_SLUB_DEBUG))
387 		VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
388 	if (__slub_debug_enabled())
389 		return s->flags & flags;
390 	return false;
391 }
392 
393 #ifdef CONFIG_MEMCG_KMEM
394 /*
395  * slab_objcgs - get the object cgroups vector associated with a slab
396  * @slab: a pointer to the slab struct
397  *
398  * Returns a pointer to the object cgroups vector associated with the slab,
399  * or NULL if no such vector has been associated yet.
400  */
401 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
402 {
403 	unsigned long memcg_data = READ_ONCE(slab->memcg_data);
404 
405 	VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS),
406 							slab_page(slab));
407 	VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
408 
409 	return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
410 }
411 
412 int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
413 				 gfp_t gfp, bool new_slab);
414 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
415 		     enum node_stat_item idx, int nr);
416 
417 static inline void memcg_free_slab_cgroups(struct slab *slab)
418 {
419 	kfree(slab_objcgs(slab));
420 	slab->memcg_data = 0;
421 }
422 
423 static inline size_t obj_full_size(struct kmem_cache *s)
424 {
425 	/*
426 	 * For each accounted object there is an extra space which is used
427 	 * to store obj_cgroup membership. Charge it too.
428 	 */
429 	return s->size + sizeof(struct obj_cgroup *);
430 }
431 
432 /*
433  * Returns false if the allocation should fail.
434  */
435 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
436 					     struct list_lru *lru,
437 					     struct obj_cgroup **objcgp,
438 					     size_t objects, gfp_t flags)
439 {
440 	struct obj_cgroup *objcg;
441 
442 	if (!memcg_kmem_online())
443 		return true;
444 
445 	if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
446 		return true;
447 
448 	objcg = get_obj_cgroup_from_current();
449 	if (!objcg)
450 		return true;
451 
452 	if (lru) {
453 		int ret;
454 		struct mem_cgroup *memcg;
455 
456 		memcg = get_mem_cgroup_from_objcg(objcg);
457 		ret = memcg_list_lru_alloc(memcg, lru, flags);
458 		css_put(&memcg->css);
459 
460 		if (ret)
461 			goto out;
462 	}
463 
464 	if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
465 		goto out;
466 
467 	*objcgp = objcg;
468 	return true;
469 out:
470 	obj_cgroup_put(objcg);
471 	return false;
472 }
473 
474 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
475 					      struct obj_cgroup *objcg,
476 					      gfp_t flags, size_t size,
477 					      void **p)
478 {
479 	struct slab *slab;
480 	unsigned long off;
481 	size_t i;
482 
483 	if (!memcg_kmem_online() || !objcg)
484 		return;
485 
486 	for (i = 0; i < size; i++) {
487 		if (likely(p[i])) {
488 			slab = virt_to_slab(p[i]);
489 
490 			if (!slab_objcgs(slab) &&
491 			    memcg_alloc_slab_cgroups(slab, s, flags,
492 							 false)) {
493 				obj_cgroup_uncharge(objcg, obj_full_size(s));
494 				continue;
495 			}
496 
497 			off = obj_to_index(s, slab, p[i]);
498 			obj_cgroup_get(objcg);
499 			slab_objcgs(slab)[off] = objcg;
500 			mod_objcg_state(objcg, slab_pgdat(slab),
501 					cache_vmstat_idx(s), obj_full_size(s));
502 		} else {
503 			obj_cgroup_uncharge(objcg, obj_full_size(s));
504 		}
505 	}
506 	obj_cgroup_put(objcg);
507 }
508 
509 static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
510 					void **p, int objects)
511 {
512 	struct obj_cgroup **objcgs;
513 	int i;
514 
515 	if (!memcg_kmem_online())
516 		return;
517 
518 	objcgs = slab_objcgs(slab);
519 	if (!objcgs)
520 		return;
521 
522 	for (i = 0; i < objects; i++) {
523 		struct obj_cgroup *objcg;
524 		unsigned int off;
525 
526 		off = obj_to_index(s, slab, p[i]);
527 		objcg = objcgs[off];
528 		if (!objcg)
529 			continue;
530 
531 		objcgs[off] = NULL;
532 		obj_cgroup_uncharge(objcg, obj_full_size(s));
533 		mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
534 				-obj_full_size(s));
535 		obj_cgroup_put(objcg);
536 	}
537 }
538 
539 #else /* CONFIG_MEMCG_KMEM */
540 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
541 {
542 	return NULL;
543 }
544 
545 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
546 {
547 	return NULL;
548 }
549 
550 static inline int memcg_alloc_slab_cgroups(struct slab *slab,
551 					       struct kmem_cache *s, gfp_t gfp,
552 					       bool new_slab)
553 {
554 	return 0;
555 }
556 
557 static inline void memcg_free_slab_cgroups(struct slab *slab)
558 {
559 }
560 
561 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
562 					     struct list_lru *lru,
563 					     struct obj_cgroup **objcgp,
564 					     size_t objects, gfp_t flags)
565 {
566 	return true;
567 }
568 
569 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
570 					      struct obj_cgroup *objcg,
571 					      gfp_t flags, size_t size,
572 					      void **p)
573 {
574 }
575 
576 static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
577 					void **p, int objects)
578 {
579 }
580 #endif /* CONFIG_MEMCG_KMEM */
581 
582 static inline struct kmem_cache *virt_to_cache(const void *obj)
583 {
584 	struct slab *slab;
585 
586 	slab = virt_to_slab(obj);
587 	if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
588 					__func__))
589 		return NULL;
590 	return slab->slab_cache;
591 }
592 
593 static __always_inline void account_slab(struct slab *slab, int order,
594 					 struct kmem_cache *s, gfp_t gfp)
595 {
596 	if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT))
597 		memcg_alloc_slab_cgroups(slab, s, gfp, true);
598 
599 	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
600 			    PAGE_SIZE << order);
601 }
602 
603 static __always_inline void unaccount_slab(struct slab *slab, int order,
604 					   struct kmem_cache *s)
605 {
606 	if (memcg_kmem_online())
607 		memcg_free_slab_cgroups(slab);
608 
609 	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
610 			    -(PAGE_SIZE << order));
611 }
612 
613 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
614 {
615 	struct kmem_cache *cachep;
616 
617 	if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
618 	    !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
619 		return s;
620 
621 	cachep = virt_to_cache(x);
622 	if (WARN(cachep && cachep != s,
623 		  "%s: Wrong slab cache. %s but object is from %s\n",
624 		  __func__, s->name, cachep->name))
625 		print_tracking(cachep, x);
626 	return cachep;
627 }
628 
629 void free_large_kmalloc(struct folio *folio, void *object);
630 
631 size_t __ksize(const void *objp);
632 
633 static inline size_t slab_ksize(const struct kmem_cache *s)
634 {
635 #ifndef CONFIG_SLUB
636 	return s->object_size;
637 
638 #else /* CONFIG_SLUB */
639 # ifdef CONFIG_SLUB_DEBUG
640 	/*
641 	 * Debugging requires use of the padding between object
642 	 * and whatever may come after it.
643 	 */
644 	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
645 		return s->object_size;
646 # endif
647 	if (s->flags & SLAB_KASAN)
648 		return s->object_size;
649 	/*
650 	 * If we have the need to store the freelist pointer
651 	 * back there or track user information then we can
652 	 * only use the space before that information.
653 	 */
654 	if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
655 		return s->inuse;
656 	/*
657 	 * Else we can use all the padding etc for the allocation
658 	 */
659 	return s->size;
660 #endif
661 }
662 
663 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
664 						     struct list_lru *lru,
665 						     struct obj_cgroup **objcgp,
666 						     size_t size, gfp_t flags)
667 {
668 	flags &= gfp_allowed_mask;
669 
670 	might_alloc(flags);
671 
672 	if (should_failslab(s, flags))
673 		return NULL;
674 
675 	if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
676 		return NULL;
677 
678 	return s;
679 }
680 
681 static inline void slab_post_alloc_hook(struct kmem_cache *s,
682 					struct obj_cgroup *objcg, gfp_t flags,
683 					size_t size, void **p, bool init,
684 					unsigned int orig_size)
685 {
686 	unsigned int zero_size = s->object_size;
687 	size_t i;
688 
689 	flags &= gfp_allowed_mask;
690 
691 	/*
692 	 * For kmalloc object, the allocated memory size(object_size) is likely
693 	 * larger than the requested size(orig_size). If redzone check is
694 	 * enabled for the extra space, don't zero it, as it will be redzoned
695 	 * soon. The redzone operation for this extra space could be seen as a
696 	 * replacement of current poisoning under certain debug option, and
697 	 * won't break other sanity checks.
698 	 */
699 	if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
700 	    (s->flags & SLAB_KMALLOC))
701 		zero_size = orig_size;
702 
703 	/*
704 	 * As memory initialization might be integrated into KASAN,
705 	 * kasan_slab_alloc and initialization memset must be
706 	 * kept together to avoid discrepancies in behavior.
707 	 *
708 	 * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
709 	 */
710 	for (i = 0; i < size; i++) {
711 		p[i] = kasan_slab_alloc(s, p[i], flags, init);
712 		if (p[i] && init && !kasan_has_integrated_init())
713 			memset(p[i], 0, zero_size);
714 		kmemleak_alloc_recursive(p[i], s->object_size, 1,
715 					 s->flags, flags);
716 		kmsan_slab_alloc(s, p[i], flags);
717 	}
718 
719 	memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
720 }
721 
722 /*
723  * The slab lists for all objects.
724  */
725 struct kmem_cache_node {
726 #ifdef CONFIG_SLAB
727 	raw_spinlock_t list_lock;
728 	struct list_head slabs_partial;	/* partial list first, better asm code */
729 	struct list_head slabs_full;
730 	struct list_head slabs_free;
731 	unsigned long total_slabs;	/* length of all slab lists */
732 	unsigned long free_slabs;	/* length of free slab list only */
733 	unsigned long free_objects;
734 	unsigned int free_limit;
735 	unsigned int colour_next;	/* Per-node cache coloring */
736 	struct array_cache *shared;	/* shared per node */
737 	struct alien_cache **alien;	/* on other nodes */
738 	unsigned long next_reap;	/* updated without locking */
739 	int free_touched;		/* updated without locking */
740 #endif
741 
742 #ifdef CONFIG_SLUB
743 	spinlock_t list_lock;
744 	unsigned long nr_partial;
745 	struct list_head partial;
746 #ifdef CONFIG_SLUB_DEBUG
747 	atomic_long_t nr_slabs;
748 	atomic_long_t total_objects;
749 	struct list_head full;
750 #endif
751 #endif
752 
753 };
754 
755 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
756 {
757 	return s->node[node];
758 }
759 
760 /*
761  * Iterator over all nodes. The body will be executed for each node that has
762  * a kmem_cache_node structure allocated (which is true for all online nodes)
763  */
764 #define for_each_kmem_cache_node(__s, __node, __n) \
765 	for (__node = 0; __node < nr_node_ids; __node++) \
766 		 if ((__n = get_node(__s, __node)))
767 
768 
769 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
770 void dump_unreclaimable_slab(void);
771 #else
772 static inline void dump_unreclaimable_slab(void)
773 {
774 }
775 #endif
776 
777 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
778 
779 #ifdef CONFIG_SLAB_FREELIST_RANDOM
780 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
781 			gfp_t gfp);
782 void cache_random_seq_destroy(struct kmem_cache *cachep);
783 #else
784 static inline int cache_random_seq_create(struct kmem_cache *cachep,
785 					unsigned int count, gfp_t gfp)
786 {
787 	return 0;
788 }
789 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
790 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
791 
792 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
793 {
794 	if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
795 				&init_on_alloc)) {
796 		if (c->ctor)
797 			return false;
798 		if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
799 			return flags & __GFP_ZERO;
800 		return true;
801 	}
802 	return flags & __GFP_ZERO;
803 }
804 
805 static inline bool slab_want_init_on_free(struct kmem_cache *c)
806 {
807 	if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
808 				&init_on_free))
809 		return !(c->ctor ||
810 			 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
811 	return false;
812 }
813 
814 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
815 void debugfs_slab_release(struct kmem_cache *);
816 #else
817 static inline void debugfs_slab_release(struct kmem_cache *s) { }
818 #endif
819 
820 #ifdef CONFIG_PRINTK
821 #define KS_ADDRS_COUNT 16
822 struct kmem_obj_info {
823 	void *kp_ptr;
824 	struct slab *kp_slab;
825 	void *kp_objp;
826 	unsigned long kp_data_offset;
827 	struct kmem_cache *kp_slab_cache;
828 	void *kp_ret;
829 	void *kp_stack[KS_ADDRS_COUNT];
830 	void *kp_free_stack[KS_ADDRS_COUNT];
831 };
832 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
833 #endif
834 
835 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
836 void __check_heap_object(const void *ptr, unsigned long n,
837 			 const struct slab *slab, bool to_user);
838 #else
839 static inline
840 void __check_heap_object(const void *ptr, unsigned long n,
841 			 const struct slab *slab, bool to_user)
842 {
843 }
844 #endif
845 
846 #ifdef CONFIG_SLUB_DEBUG
847 void skip_orig_size_check(struct kmem_cache *s, const void *object);
848 #endif
849 
850 #endif /* MM_SLAB_H */
851