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