1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef MM_SLAB_H
3#define MM_SLAB_H
4/*
5 * Internal slab definitions
6 */
7void __init kmem_cache_init(void);
8
9#ifdef CONFIG_64BIT
10# ifdef system_has_cmpxchg128
11# define system_has_freelist_aba() system_has_cmpxchg128()
12# define try_cmpxchg_freelist try_cmpxchg128
13# endif
14#define this_cpu_try_cmpxchg_freelist this_cpu_try_cmpxchg128
15typedef u128 freelist_full_t;
16#else /* CONFIG_64BIT */
17# ifdef system_has_cmpxchg64
18# define system_has_freelist_aba() system_has_cmpxchg64()
19# define try_cmpxchg_freelist try_cmpxchg64
20# endif
21#define this_cpu_try_cmpxchg_freelist this_cpu_try_cmpxchg64
22typedef u64 freelist_full_t;
23#endif /* CONFIG_64BIT */
24
25#if defined(system_has_freelist_aba) && !defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
26#undef system_has_freelist_aba
27#endif
28
29/*
30 * Freelist pointer and counter to cmpxchg together, avoids the typical ABA
31 * problems with cmpxchg of just a pointer.
32 */
33typedef union {
34 struct {
35 void *freelist;
36 unsigned long counter;
37 };
38 freelist_full_t full;
39} freelist_aba_t;
40
41/* Reuses the bits in struct page */
42struct slab {
43 unsigned long __page_flags;
44
45#if defined(CONFIG_SLAB)
46
47 struct kmem_cache *slab_cache;
48 union {
49 struct {
50 struct list_head slab_list;
51 void *freelist; /* array of free object indexes */
52 void *s_mem; /* first object */
53 };
54 struct rcu_head rcu_head;
55 };
56 unsigned int active;
57
58#elif defined(CONFIG_SLUB)
59
60 struct kmem_cache *slab_cache;
61 union {
62 struct {
63 union {
64 struct list_head slab_list;
65#ifdef CONFIG_SLUB_CPU_PARTIAL
66 struct {
67 struct slab *next;
68 int slabs; /* Nr of slabs left */
69 };
70#endif
71 };
72 /* Double-word boundary */
73 union {
74 struct {
75 void *freelist; /* first free object */
76 union {
77 unsigned long counters;
78 struct {
79 unsigned inuse:16;
80 unsigned objects:15;
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 unsigned int __unused;
93
94#else
95#error "Unexpected slab allocator configured"
96#endif
97
98 atomic_t __page_refcount;
99#ifdef CONFIG_MEMCG
100 unsigned long memcg_data;
101#endif
102};
103
104#define SLAB_MATCH(pg, sl) \
105 static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
106SLAB_MATCH(flags, __page_flags);
107SLAB_MATCH(compound_head, slab_cache); /* Ensure bit 0 is clear */
108SLAB_MATCH(_refcount, __page_refcount);
109#ifdef CONFIG_MEMCG
110SLAB_MATCH(memcg_data, memcg_data);
111#endif
112#undef SLAB_MATCH
113static_assert(sizeof(struct slab) <= sizeof(struct page));
114#if defined(system_has_freelist_aba) && defined(CONFIG_SLUB)
115static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t)));
116#endif
117
118/**
119 * folio_slab - Converts from folio to slab.
120 * @folio: The folio.
121 *
122 * Currently struct slab is a different representation of a folio where
123 * folio_test_slab() is true.
124 *
125 * Return: The slab which contains this folio.
126 */
127#define folio_slab(folio) (_Generic((folio), \
128 const struct folio *: (const struct slab *)(folio), \
129 struct folio *: (struct slab *)(folio)))
130
131/**
132 * slab_folio - The folio allocated for a slab
133 * @slab: The slab.
134 *
135 * Slabs are allocated as folios that contain the individual objects and are
136 * using some fields in the first struct page of the folio - those fields are
137 * now accessed by struct slab. It is occasionally necessary to convert back to
138 * a folio in order to communicate with the rest of the mm. Please use this
139 * helper function instead of casting yourself, as the implementation may change
140 * in the future.
141 */
142#define slab_folio(s) (_Generic((s), \
143 const struct slab *: (const struct folio *)s, \
144 struct slab *: (struct folio *)s))
145
146/**
147 * page_slab - Converts from first struct page to slab.
148 * @p: The first (either head of compound or single) page of slab.
149 *
150 * A temporary wrapper to convert struct page to struct slab in situations where
151 * we know the page is the compound head, or single order-0 page.
152 *
153 * Long-term ideally everything would work with struct slab directly or go
154 * through folio to struct slab.
155 *
156 * Return: The slab which contains this page
157 */
158#define page_slab(p) (_Generic((p), \
159 const struct page *: (const struct slab *)(p), \
160 struct page *: (struct slab *)(p)))
161
162/**
163 * slab_page - The first struct page allocated for a slab
164 * @slab: The slab.
165 *
166 * A convenience wrapper for converting slab to the first struct page of the
167 * underlying folio, to communicate with code not yet converted to folio or
168 * struct slab.
169 */
170#define slab_page(s) folio_page(slab_folio(s), 0)
171
172/*
173 * If network-based swap is enabled, sl*b must keep track of whether pages
174 * were allocated from pfmemalloc reserves.
175 */
176static inline bool slab_test_pfmemalloc(const struct slab *slab)
177{
178 return folio_test_active(folio: (struct folio *)slab_folio(slab));
179}
180
181static inline void slab_set_pfmemalloc(struct slab *slab)
182{
183 folio_set_active(slab_folio(slab));
184}
185
186static inline void slab_clear_pfmemalloc(struct slab *slab)
187{
188 folio_clear_active(slab_folio(slab));
189}
190
191static inline void __slab_clear_pfmemalloc(struct slab *slab)
192{
193 __folio_clear_active(slab_folio(slab));
194}
195
196static inline void *slab_address(const struct slab *slab)
197{
198 return folio_address(slab_folio(slab));
199}
200
201static inline int slab_nid(const struct slab *slab)
202{
203 return folio_nid(slab_folio(slab));
204}
205
206static inline pg_data_t *slab_pgdat(const struct slab *slab)
207{
208 return folio_pgdat(slab_folio(slab));
209}
210
211static inline struct slab *virt_to_slab(const void *addr)
212{
213 struct folio *folio = virt_to_folio(x: addr);
214
215 if (!folio_test_slab(folio))
216 return NULL;
217
218 return folio_slab(folio);
219}
220
221static inline int slab_order(const struct slab *slab)
222{
223 return folio_order(folio: (struct folio *)slab_folio(slab));
224}
225
226static inline size_t slab_size(const struct slab *slab)
227{
228 return PAGE_SIZE << slab_order(slab);
229}
230
231#ifdef CONFIG_SLAB
232#include <linux/slab_def.h>
233#endif
234
235#ifdef CONFIG_SLUB
236#include <linux/slub_def.h>
237#endif
238
239#include <linux/memcontrol.h>
240#include <linux/fault-inject.h>
241#include <linux/kasan.h>
242#include <linux/kmemleak.h>
243#include <linux/random.h>
244#include <linux/sched/mm.h>
245#include <linux/list_lru.h>
246
247/*
248 * State of the slab allocator.
249 *
250 * This is used to describe the states of the allocator during bootup.
251 * Allocators use this to gradually bootstrap themselves. Most allocators
252 * have the problem that the structures used for managing slab caches are
253 * allocated from slab caches themselves.
254 */
255enum slab_state {
256 DOWN, /* No slab functionality yet */
257 PARTIAL, /* SLUB: kmem_cache_node available */
258 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
259 UP, /* Slab caches usable but not all extras yet */
260 FULL /* Everything is working */
261};
262
263extern enum slab_state slab_state;
264
265/* The slab cache mutex protects the management structures during changes */
266extern struct mutex slab_mutex;
267
268/* The list of all slab caches on the system */
269extern struct list_head slab_caches;
270
271/* The slab cache that manages slab cache information */
272extern struct kmem_cache *kmem_cache;
273
274/* A table of kmalloc cache names and sizes */
275extern const struct kmalloc_info_struct {
276 const char *name[NR_KMALLOC_TYPES];
277 unsigned int size;
278} kmalloc_info[];
279
280/* Kmalloc array related functions */
281void setup_kmalloc_cache_index_table(void);
282void create_kmalloc_caches(slab_flags_t);
283
284/* Find the kmalloc slab corresponding for a certain size */
285struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags, unsigned long caller);
286
287void *__kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags,
288 int node, size_t orig_size,
289 unsigned long caller);
290void __kmem_cache_free(struct kmem_cache *s, void *x, unsigned long caller);
291
292gfp_t kmalloc_fix_flags(gfp_t flags);
293
294/* Functions provided by the slab allocators */
295int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
296
297void __init new_kmalloc_cache(int idx, enum kmalloc_cache_type type,
298 slab_flags_t flags);
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 *));
306struct kmem_cache *
307__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
308 slab_flags_t flags, void (*ctor)(void *));
309
310slab_flags_t kmem_cache_flags(unsigned int object_size,
311 slab_flags_t flags, const char *name);
312
313static inline bool is_kmalloc_cache(struct kmem_cache *s)
314{
315 return (s->flags & SLAB_KMALLOC);
316}
317
318/* Legal flag mask for kmem_cache_create(), for various configurations */
319#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
320 SLAB_CACHE_DMA32 | SLAB_PANIC | \
321 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
322
323#if defined(CONFIG_DEBUG_SLAB)
324#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
325#elif defined(CONFIG_SLUB_DEBUG)
326#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
327 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
328#else
329#define SLAB_DEBUG_FLAGS (0)
330#endif
331
332#if defined(CONFIG_SLAB)
333#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
334 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
335 SLAB_ACCOUNT | SLAB_NO_MERGE)
336#elif defined(CONFIG_SLUB)
337#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
338 SLAB_TEMPORARY | SLAB_ACCOUNT | \
339 SLAB_NO_USER_FLAGS | SLAB_KMALLOC | SLAB_NO_MERGE)
340#else
341#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE)
342#endif
343
344/* Common flags available with current configuration */
345#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
346
347/* Common flags permitted for kmem_cache_create */
348#define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
349 SLAB_RED_ZONE | \
350 SLAB_POISON | \
351 SLAB_STORE_USER | \
352 SLAB_TRACE | \
353 SLAB_CONSISTENCY_CHECKS | \
354 SLAB_MEM_SPREAD | \
355 SLAB_NOLEAKTRACE | \
356 SLAB_RECLAIM_ACCOUNT | \
357 SLAB_TEMPORARY | \
358 SLAB_ACCOUNT | \
359 SLAB_KMALLOC | \
360 SLAB_NO_MERGE | \
361 SLAB_NO_USER_FLAGS)
362
363bool __kmem_cache_empty(struct kmem_cache *);
364int __kmem_cache_shutdown(struct kmem_cache *);
365void __kmem_cache_release(struct kmem_cache *);
366int __kmem_cache_shrink(struct kmem_cache *);
367void slab_kmem_cache_release(struct kmem_cache *);
368
369struct seq_file;
370struct file;
371
372struct slabinfo {
373 unsigned long active_objs;
374 unsigned long num_objs;
375 unsigned long active_slabs;
376 unsigned long num_slabs;
377 unsigned long shared_avail;
378 unsigned int limit;
379 unsigned int batchcount;
380 unsigned int shared;
381 unsigned int objects_per_slab;
382 unsigned int cache_order;
383};
384
385void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
386void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
387ssize_t slabinfo_write(struct file *file, const char __user *buffer,
388 size_t count, loff_t *ppos);
389
390static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
391{
392 return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
393 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
394}
395
396#ifdef CONFIG_SLUB_DEBUG
397#ifdef CONFIG_SLUB_DEBUG_ON
398DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
399#else
400DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
401#endif
402extern void print_tracking(struct kmem_cache *s, void *object);
403long validate_slab_cache(struct kmem_cache *s);
404static inline bool __slub_debug_enabled(void)
405{
406 return static_branch_unlikely(&slub_debug_enabled);
407}
408#else
409static inline void print_tracking(struct kmem_cache *s, void *object)
410{
411}
412static inline bool __slub_debug_enabled(void)
413{
414 return false;
415}
416#endif
417
418/*
419 * Returns true if any of the specified slub_debug flags is enabled for the
420 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
421 * the static key.
422 */
423static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
424{
425 if (IS_ENABLED(CONFIG_SLUB_DEBUG))
426 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
427 if (__slub_debug_enabled())
428 return s->flags & flags;
429 return false;
430}
431
432#ifdef CONFIG_MEMCG_KMEM
433/*
434 * slab_objcgs - get the object cgroups vector associated with a slab
435 * @slab: a pointer to the slab struct
436 *
437 * Returns a pointer to the object cgroups vector associated with the slab,
438 * or NULL if no such vector has been associated yet.
439 */
440static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
441{
442 unsigned long memcg_data = READ_ONCE(slab->memcg_data);
443
444 VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS),
445 slab_page(slab));
446 VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
447
448 return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
449}
450
451int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
452 gfp_t gfp, bool new_slab);
453void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
454 enum node_stat_item idx, int nr);
455
456static inline void memcg_free_slab_cgroups(struct slab *slab)
457{
458 kfree(objp: slab_objcgs(slab));
459 slab->memcg_data = 0;
460}
461
462static inline size_t obj_full_size(struct kmem_cache *s)
463{
464 /*
465 * For each accounted object there is an extra space which is used
466 * to store obj_cgroup membership. Charge it too.
467 */
468 return s->size + sizeof(struct obj_cgroup *);
469}
470
471/*
472 * Returns false if the allocation should fail.
473 */
474static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
475 struct list_lru *lru,
476 struct obj_cgroup **objcgp,
477 size_t objects, gfp_t flags)
478{
479 struct obj_cgroup *objcg;
480
481 if (!memcg_kmem_online())
482 return true;
483
484 if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
485 return true;
486
487 /*
488 * The obtained objcg pointer is safe to use within the current scope,
489 * defined by current task or set_active_memcg() pair.
490 * obj_cgroup_get() is used to get a permanent reference.
491 */
492 objcg = current_obj_cgroup();
493 if (!objcg)
494 return true;
495
496 if (lru) {
497 int ret;
498 struct mem_cgroup *memcg;
499
500 memcg = get_mem_cgroup_from_objcg(objcg);
501 ret = memcg_list_lru_alloc(memcg, lru, gfp: flags);
502 css_put(css: &memcg->css);
503
504 if (ret)
505 return false;
506 }
507
508 if (obj_cgroup_charge(objcg, gfp: flags, size: objects * obj_full_size(s)))
509 return false;
510
511 *objcgp = objcg;
512 return true;
513}
514
515static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
516 struct obj_cgroup *objcg,
517 gfp_t flags, size_t size,
518 void **p)
519{
520 struct slab *slab;
521 unsigned long off;
522 size_t i;
523
524 if (!memcg_kmem_online() || !objcg)
525 return;
526
527 for (i = 0; i < size; i++) {
528 if (likely(p[i])) {
529 slab = virt_to_slab(addr: p[i]);
530
531 if (!slab_objcgs(slab) &&
532 memcg_alloc_slab_cgroups(slab, s, gfp: flags,
533 new_slab: false)) {
534 obj_cgroup_uncharge(objcg, size: obj_full_size(s));
535 continue;
536 }
537
538 off = obj_to_index(cache: s, slab, obj: p[i]);
539 obj_cgroup_get(objcg);
540 slab_objcgs(slab)[off] = objcg;
541 mod_objcg_state(objcg, pgdat: slab_pgdat(slab),
542 idx: cache_vmstat_idx(s), nr: obj_full_size(s));
543 } else {
544 obj_cgroup_uncharge(objcg, size: obj_full_size(s));
545 }
546 }
547}
548
549static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
550 void **p, int objects)
551{
552 struct obj_cgroup **objcgs;
553 int i;
554
555 if (!memcg_kmem_online())
556 return;
557
558 objcgs = slab_objcgs(slab);
559 if (!objcgs)
560 return;
561
562 for (i = 0; i < objects; i++) {
563 struct obj_cgroup *objcg;
564 unsigned int off;
565
566 off = obj_to_index(cache: s, slab, obj: p[i]);
567 objcg = objcgs[off];
568 if (!objcg)
569 continue;
570
571 objcgs[off] = NULL;
572 obj_cgroup_uncharge(objcg, size: obj_full_size(s));
573 mod_objcg_state(objcg, pgdat: slab_pgdat(slab), idx: cache_vmstat_idx(s),
574 nr: -obj_full_size(s));
575 obj_cgroup_put(objcg);
576 }
577}
578
579#else /* CONFIG_MEMCG_KMEM */
580static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
581{
582 return NULL;
583}
584
585static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
586{
587 return NULL;
588}
589
590static inline int memcg_alloc_slab_cgroups(struct slab *slab,
591 struct kmem_cache *s, gfp_t gfp,
592 bool new_slab)
593{
594 return 0;
595}
596
597static inline void memcg_free_slab_cgroups(struct slab *slab)
598{
599}
600
601static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
602 struct list_lru *lru,
603 struct obj_cgroup **objcgp,
604 size_t objects, gfp_t flags)
605{
606 return true;
607}
608
609static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
610 struct obj_cgroup *objcg,
611 gfp_t flags, size_t size,
612 void **p)
613{
614}
615
616static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
617 void **p, int objects)
618{
619}
620#endif /* CONFIG_MEMCG_KMEM */
621
622static inline struct kmem_cache *virt_to_cache(const void *obj)
623{
624 struct slab *slab;
625
626 slab = virt_to_slab(addr: obj);
627 if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
628 __func__))
629 return NULL;
630 return slab->slab_cache;
631}
632
633static __always_inline void account_slab(struct slab *slab, int order,
634 struct kmem_cache *s, gfp_t gfp)
635{
636 if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT))
637 memcg_alloc_slab_cgroups(slab, s, gfp, new_slab: true);
638
639 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
640 PAGE_SIZE << order);
641}
642
643static __always_inline void unaccount_slab(struct slab *slab, int order,
644 struct kmem_cache *s)
645{
646 if (memcg_kmem_online())
647 memcg_free_slab_cgroups(slab);
648
649 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
650 -(PAGE_SIZE << order));
651}
652
653static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
654{
655 struct kmem_cache *cachep;
656
657 if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
658 !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
659 return s;
660
661 cachep = virt_to_cache(obj: x);
662 if (WARN(cachep && cachep != s,
663 "%s: Wrong slab cache. %s but object is from %s\n",
664 __func__, s->name, cachep->name))
665 print_tracking(s: cachep, object: x);
666 return cachep;
667}
668
669void free_large_kmalloc(struct folio *folio, void *object);
670
671size_t __ksize(const void *objp);
672
673static inline size_t slab_ksize(const struct kmem_cache *s)
674{
675#ifndef CONFIG_SLUB
676 return s->object_size;
677
678#else /* CONFIG_SLUB */
679# ifdef CONFIG_SLUB_DEBUG
680 /*
681 * Debugging requires use of the padding between object
682 * and whatever may come after it.
683 */
684 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
685 return s->object_size;
686# endif
687 if (s->flags & SLAB_KASAN)
688 return s->object_size;
689 /*
690 * If we have the need to store the freelist pointer
691 * back there or track user information then we can
692 * only use the space before that information.
693 */
694 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
695 return s->inuse;
696 /*
697 * Else we can use all the padding etc for the allocation
698 */
699 return s->size;
700#endif
701}
702
703static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
704 struct list_lru *lru,
705 struct obj_cgroup **objcgp,
706 size_t size, gfp_t flags)
707{
708 flags &= gfp_allowed_mask;
709
710 might_alloc(gfp_mask: flags);
711
712 if (should_failslab(s, gfpflags: flags))
713 return NULL;
714
715 if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, objects: size, flags))
716 return NULL;
717
718 return s;
719}
720
721static inline void slab_post_alloc_hook(struct kmem_cache *s,
722 struct obj_cgroup *objcg, gfp_t flags,
723 size_t size, void **p, bool init,
724 unsigned int orig_size)
725{
726 unsigned int zero_size = s->object_size;
727 bool kasan_init = init;
728 size_t i;
729
730 flags &= gfp_allowed_mask;
731
732 /*
733 * For kmalloc object, the allocated memory size(object_size) is likely
734 * larger than the requested size(orig_size). If redzone check is
735 * enabled for the extra space, don't zero it, as it will be redzoned
736 * soon. The redzone operation for this extra space could be seen as a
737 * replacement of current poisoning under certain debug option, and
738 * won't break other sanity checks.
739 */
740 if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
741 (s->flags & SLAB_KMALLOC))
742 zero_size = orig_size;
743
744 /*
745 * When slub_debug is enabled, avoid memory initialization integrated
746 * into KASAN and instead zero out the memory via the memset below with
747 * the proper size. Otherwise, KASAN might overwrite SLUB redzones and
748 * cause false-positive reports. This does not lead to a performance
749 * penalty on production builds, as slub_debug is not intended to be
750 * enabled there.
751 */
752 if (__slub_debug_enabled())
753 kasan_init = false;
754
755 /*
756 * As memory initialization might be integrated into KASAN,
757 * kasan_slab_alloc and initialization memset must be
758 * kept together to avoid discrepancies in behavior.
759 *
760 * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
761 */
762 for (i = 0; i < size; i++) {
763 p[i] = kasan_slab_alloc(s, object: p[i], flags, init: kasan_init);
764 if (p[i] && init && (!kasan_init || !kasan_has_integrated_init()))
765 memset(p[i], 0, zero_size);
766 kmemleak_alloc_recursive(ptr: p[i], size: s->object_size, min_count: 1,
767 flags: s->flags, gfp: flags);
768 kmsan_slab_alloc(s, object: p[i], flags);
769 }
770
771 memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
772}
773
774/*
775 * The slab lists for all objects.
776 */
777struct kmem_cache_node {
778#ifdef CONFIG_SLAB
779 raw_spinlock_t list_lock;
780 struct list_head slabs_partial; /* partial list first, better asm code */
781 struct list_head slabs_full;
782 struct list_head slabs_free;
783 unsigned long total_slabs; /* length of all slab lists */
784 unsigned long free_slabs; /* length of free slab list only */
785 unsigned long free_objects;
786 unsigned int free_limit;
787 unsigned int colour_next; /* Per-node cache coloring */
788 struct array_cache *shared; /* shared per node */
789 struct alien_cache **alien; /* on other nodes */
790 unsigned long next_reap; /* updated without locking */
791 int free_touched; /* updated without locking */
792#endif
793
794#ifdef CONFIG_SLUB
795 spinlock_t list_lock;
796 unsigned long nr_partial;
797 struct list_head partial;
798#ifdef CONFIG_SLUB_DEBUG
799 atomic_long_t nr_slabs;
800 atomic_long_t total_objects;
801 struct list_head full;
802#endif
803#endif
804
805};
806
807static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
808{
809 return s->node[node];
810}
811
812/*
813 * Iterator over all nodes. The body will be executed for each node that has
814 * a kmem_cache_node structure allocated (which is true for all online nodes)
815 */
816#define for_each_kmem_cache_node(__s, __node, __n) \
817 for (__node = 0; __node < nr_node_ids; __node++) \
818 if ((__n = get_node(__s, __node)))
819
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
887void __check_heap_object(const void *ptr, unsigned long n,
888 const struct slab *slab, bool to_user);
889
890#ifdef CONFIG_SLUB_DEBUG
891void skip_orig_size_check(struct kmem_cache *s, const void *object);
892#endif
893
894#endif /* MM_SLAB_H */
895

source code of linux/mm/slab.h