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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 */
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#ifdef CONFIG_SLOB
9/*
10 * Common fields provided in kmem_cache by all slab allocators
11 * This struct is either used directly by the allocator (SLOB)
12 * or the allocator must include definitions for all fields
13 * provided in kmem_cache_common in their definition of kmem_cache.
14 *
15 * Once we can do anonymous structs (C11 standard) we could put a
16 * anonymous struct definition in these allocators so that the
17 * separate allocations in the kmem_cache structure of SLAB and
18 * SLUB is no longer needed.
19 */
20struct kmem_cache {
21 unsigned int object_size;/* The original size of the object */
22 unsigned int size; /* The aligned/padded/added on size */
23 unsigned int align; /* Alignment as calculated */
24 slab_flags_t flags; /* Active flags on the slab */
25 unsigned int useroffset;/* Usercopy region offset */
26 unsigned int usersize; /* Usercopy region size */
27 const char *name; /* Slab name for sysfs */
28 int refcount; /* Use counter */
29 void (*ctor)(void *); /* Called on object slot creation */
30 struct list_head list; /* List of all slab caches on the system */
31};
32
33#endif /* CONFIG_SLOB */
34
35#ifdef CONFIG_SLAB
36#include <linux/slab_def.h>
37#endif
38
39#ifdef CONFIG_SLUB
40#include <linux/slub_def.h>
41#endif
42
43#include <linux/memcontrol.h>
44#include <linux/fault-inject.h>
45#include <linux/kasan.h>
46#include <linux/kmemleak.h>
47#include <linux/random.h>
48#include <linux/sched/mm.h>
49
50/*
51 * State of the slab allocator.
52 *
53 * This is used to describe the states of the allocator during bootup.
54 * Allocators use this to gradually bootstrap themselves. Most allocators
55 * have the problem that the structures used for managing slab caches are
56 * allocated from slab caches themselves.
57 */
58enum slab_state {
59 DOWN, /* No slab functionality yet */
60 PARTIAL, /* SLUB: kmem_cache_node available */
61 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
62 UP, /* Slab caches usable but not all extras yet */
63 FULL /* Everything is working */
64};
65
66extern enum slab_state slab_state;
67
68/* The slab cache mutex protects the management structures during changes */
69extern struct mutex slab_mutex;
70
71/* The list of all slab caches on the system */
72extern struct list_head slab_caches;
73
74/* The slab cache that manages slab cache information */
75extern struct kmem_cache *kmem_cache;
76
77/* A table of kmalloc cache names and sizes */
78extern const struct kmalloc_info_struct {
79 const char *name[NR_KMALLOC_TYPES];
80 unsigned int size;
81} kmalloc_info[];
82
83#ifndef CONFIG_SLOB
84/* Kmalloc array related functions */
85void setup_kmalloc_cache_index_table(void);
86void create_kmalloc_caches(slab_flags_t);
87
88/* Find the kmalloc slab corresponding for a certain size */
89struct kmem_cache *kmalloc_slab(size_t, gfp_t);
90#endif
91
92gfp_t kmalloc_fix_flags(gfp_t flags);
93
94/* Functions provided by the slab allocators */
95int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
96
97struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
98 slab_flags_t flags, unsigned int useroffset,
99 unsigned int usersize);
100extern void create_boot_cache(struct kmem_cache *, const char *name,
101 unsigned int size, slab_flags_t flags,
102 unsigned int useroffset, unsigned int usersize);
103
104int slab_unmergeable(struct kmem_cache *s);
105struct kmem_cache *find_mergeable(unsigned size, unsigned align,
106 slab_flags_t flags, const char *name, void (*ctor)(void *));
107#ifndef CONFIG_SLOB
108struct kmem_cache *
109__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
110 slab_flags_t flags, void (*ctor)(void *));
111
112slab_flags_t kmem_cache_flags(unsigned int object_size,
113 slab_flags_t flags, const char *name);
114#else
115static inline struct kmem_cache *
116__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
117 slab_flags_t flags, void (*ctor)(void *))
118{ return NULL; }
119
120static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
121 slab_flags_t flags, const char *name)
122{
123 return flags;
124}
125#endif
126
127
128/* Legal flag mask for kmem_cache_create(), for various configurations */
129#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
130 SLAB_CACHE_DMA32 | SLAB_PANIC | \
131 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
132
133#if defined(CONFIG_DEBUG_SLAB)
134#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
135#elif defined(CONFIG_SLUB_DEBUG)
136#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
137 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
138#else
139#define SLAB_DEBUG_FLAGS (0)
140#endif
141
142#if defined(CONFIG_SLAB)
143#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
144 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
145 SLAB_ACCOUNT)
146#elif defined(CONFIG_SLUB)
147#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
148 SLAB_TEMPORARY | SLAB_ACCOUNT)
149#else
150#define SLAB_CACHE_FLAGS (0)
151#endif
152
153/* Common flags available with current configuration */
154#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
155
156/* Common flags permitted for kmem_cache_create */
157#define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
158 SLAB_RED_ZONE | \
159 SLAB_POISON | \
160 SLAB_STORE_USER | \
161 SLAB_TRACE | \
162 SLAB_CONSISTENCY_CHECKS | \
163 SLAB_MEM_SPREAD | \
164 SLAB_NOLEAKTRACE | \
165 SLAB_RECLAIM_ACCOUNT | \
166 SLAB_TEMPORARY | \
167 SLAB_ACCOUNT)
168
169bool __kmem_cache_empty(struct kmem_cache *);
170int __kmem_cache_shutdown(struct kmem_cache *);
171void __kmem_cache_release(struct kmem_cache *);
172int __kmem_cache_shrink(struct kmem_cache *);
173void slab_kmem_cache_release(struct kmem_cache *);
174
175struct seq_file;
176struct file;
177
178struct slabinfo {
179 unsigned long active_objs;
180 unsigned long num_objs;
181 unsigned long active_slabs;
182 unsigned long num_slabs;
183 unsigned long shared_avail;
184 unsigned int limit;
185 unsigned int batchcount;
186 unsigned int shared;
187 unsigned int objects_per_slab;
188 unsigned int cache_order;
189};
190
191void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
192void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
193ssize_t slabinfo_write(struct file *file, const char __user *buffer,
194 size_t count, loff_t *ppos);
195
196/*
197 * Generic implementation of bulk operations
198 * These are useful for situations in which the allocator cannot
199 * perform optimizations. In that case segments of the object listed
200 * may be allocated or freed using these operations.
201 */
202void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
203int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
204
205static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
206{
207 return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
208 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
209}
210
211#ifdef CONFIG_SLUB_DEBUG
212#ifdef CONFIG_SLUB_DEBUG_ON
213DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
214#else
215DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
216#endif
217extern void print_tracking(struct kmem_cache *s, void *object);
218long validate_slab_cache(struct kmem_cache *s);
219static inline bool __slub_debug_enabled(void)
220{
221 return static_branch_unlikely(&slub_debug_enabled);
222}
223#else
224static inline void print_tracking(struct kmem_cache *s, void *object)
225{
226}
227static inline bool __slub_debug_enabled(void)
228{
229 return false;
230}
231#endif
232
233/*
234 * Returns true if any of the specified slub_debug flags is enabled for the
235 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
236 * the static key.
237 */
238static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
239{
240 if (IS_ENABLED(CONFIG_SLUB_DEBUG))
241 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
242 if (__slub_debug_enabled())
243 return s->flags & flags;
244 return false;
245}
246
247#ifdef CONFIG_MEMCG_KMEM
248int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
249 gfp_t gfp, bool new_page);
250void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
251 enum node_stat_item idx, int nr);
252
253static inline void memcg_free_page_obj_cgroups(struct page *page)
254{
255 kfree(page_objcgs(page));
256 page->memcg_data = 0;
257}
258
259static inline size_t obj_full_size(struct kmem_cache *s)
260{
261 /*
262 * For each accounted object there is an extra space which is used
263 * to store obj_cgroup membership. Charge it too.
264 */
265 return s->size + sizeof(struct obj_cgroup *);
266}
267
268/*
269 * Returns false if the allocation should fail.
270 */
271static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
272 struct obj_cgroup **objcgp,
273 size_t objects, gfp_t flags)
274{
275 struct obj_cgroup *objcg;
276
277 if (!memcg_kmem_enabled())
278 return true;
279
280 if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
281 return true;
282
283 objcg = get_obj_cgroup_from_current();
284 if (!objcg)
285 return true;
286
287 if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) {
288 obj_cgroup_put(objcg);
289 return false;
290 }
291
292 *objcgp = objcg;
293 return true;
294}
295
296static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
297 struct obj_cgroup *objcg,
298 gfp_t flags, size_t size,
299 void **p)
300{
301 struct page *page;
302 unsigned long off;
303 size_t i;
304
305 if (!memcg_kmem_enabled() || !objcg)
306 return;
307
308 for (i = 0; i < size; i++) {
309 if (likely(p[i])) {
310 page = virt_to_head_page(p[i]);
311
312 if (!page_objcgs(page) &&
313 memcg_alloc_page_obj_cgroups(page, s, flags,
314 false)) {
315 obj_cgroup_uncharge(objcg, obj_full_size(s));
316 continue;
317 }
318
319 off = obj_to_index(s, page, p[i]);
320 obj_cgroup_get(objcg);
321 page_objcgs(page)[off] = objcg;
322 mod_objcg_state(objcg, page_pgdat(page),
323 cache_vmstat_idx(s), obj_full_size(s));
324 } else {
325 obj_cgroup_uncharge(objcg, obj_full_size(s));
326 }
327 }
328 obj_cgroup_put(objcg);
329}
330
331static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
332 void **p, int objects)
333{
334 struct kmem_cache *s;
335 struct obj_cgroup **objcgs;
336 struct obj_cgroup *objcg;
337 struct page *page;
338 unsigned int off;
339 int i;
340
341 if (!memcg_kmem_enabled())
342 return;
343
344 for (i = 0; i < objects; i++) {
345 if (unlikely(!p[i]))
346 continue;
347
348 page = virt_to_head_page(p[i]);
349 objcgs = page_objcgs_check(page);
350 if (!objcgs)
351 continue;
352
353 if (!s_orig)
354 s = page->slab_cache;
355 else
356 s = s_orig;
357
358 off = obj_to_index(s, page, p[i]);
359 objcg = objcgs[off];
360 if (!objcg)
361 continue;
362
363 objcgs[off] = NULL;
364 obj_cgroup_uncharge(objcg, obj_full_size(s));
365 mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s),
366 -obj_full_size(s));
367 obj_cgroup_put(objcg);
368 }
369}
370
371#else /* CONFIG_MEMCG_KMEM */
372static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
373{
374 return NULL;
375}
376
377static inline int memcg_alloc_page_obj_cgroups(struct page *page,
378 struct kmem_cache *s, gfp_t gfp,
379 bool new_page)
380{
381 return 0;
382}
383
384static inline void memcg_free_page_obj_cgroups(struct page *page)
385{
386}
387
388static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
389 struct obj_cgroup **objcgp,
390 size_t objects, gfp_t flags)
391{
392 return true;
393}
394
395static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
396 struct obj_cgroup *objcg,
397 gfp_t flags, size_t size,
398 void **p)
399{
400}
401
402static inline void memcg_slab_free_hook(struct kmem_cache *s,
403 void **p, int objects)
404{
405}
406#endif /* CONFIG_MEMCG_KMEM */
407
408static inline struct kmem_cache *virt_to_cache(const void *obj)
409{
410 struct page *page;
411
412 page = virt_to_head_page(obj);
413 if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n",
414 __func__))
415 return NULL;
416 return page->slab_cache;
417}
418
419static __always_inline void account_slab_page(struct page *page, int order,
420 struct kmem_cache *s,
421 gfp_t gfp)
422{
423 if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT))
424 memcg_alloc_page_obj_cgroups(page, s, gfp, true);
425
426 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
427 PAGE_SIZE << order);
428}
429
430static __always_inline void unaccount_slab_page(struct page *page, int order,
431 struct kmem_cache *s)
432{
433 if (memcg_kmem_enabled())
434 memcg_free_page_obj_cgroups(page);
435
436 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
437 -(PAGE_SIZE << order));
438}
439
440static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
441{
442 struct kmem_cache *cachep;
443
444 if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
445 !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
446 return s;
447
448 cachep = virt_to_cache(x);
449 if (WARN(cachep && cachep != s,
450 "%s: Wrong slab cache. %s but object is from %s\n",
451 __func__, s->name, cachep->name))
452 print_tracking(cachep, x);
453 return cachep;
454}
455
456static inline size_t slab_ksize(const struct kmem_cache *s)
457{
458#ifndef CONFIG_SLUB
459 return s->object_size;
460
461#else /* CONFIG_SLUB */
462# ifdef CONFIG_SLUB_DEBUG
463 /*
464 * Debugging requires use of the padding between object
465 * and whatever may come after it.
466 */
467 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
468 return s->object_size;
469# endif
470 if (s->flags & SLAB_KASAN)
471 return s->object_size;
472 /*
473 * If we have the need to store the freelist pointer
474 * back there or track user information then we can
475 * only use the space before that information.
476 */
477 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
478 return s->inuse;
479 /*
480 * Else we can use all the padding etc for the allocation
481 */
482 return s->size;
483#endif
484}
485
486static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
487 struct obj_cgroup **objcgp,
488 size_t size, gfp_t flags)
489{
490 flags &= gfp_allowed_mask;
491
492 might_alloc(flags);
493
494 if (should_failslab(s, flags))
495 return NULL;
496
497 if (!memcg_slab_pre_alloc_hook(s, objcgp, size, flags))
498 return NULL;
499
500 return s;
501}
502
503static inline void slab_post_alloc_hook(struct kmem_cache *s,
504 struct obj_cgroup *objcg, gfp_t flags,
505 size_t size, void **p, bool init)
506{
507 size_t i;
508
509 flags &= gfp_allowed_mask;
510
511 /*
512 * As memory initialization might be integrated into KASAN,
513 * kasan_slab_alloc and initialization memset must be
514 * kept together to avoid discrepancies in behavior.
515 *
516 * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
517 */
518 for (i = 0; i < size; i++) {
519 p[i] = kasan_slab_alloc(s, p[i], flags, init);
520 if (p[i] && init && !kasan_has_integrated_init())
521 memset(p[i], 0, s->object_size);
522 kmemleak_alloc_recursive(p[i], s->object_size, 1,
523 s->flags, flags);
524 }
525
526 memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
527}
528
529#ifndef CONFIG_SLOB
530/*
531 * The slab lists for all objects.
532 */
533struct kmem_cache_node {
534 spinlock_t list_lock;
535
536#ifdef CONFIG_SLAB
537 struct list_head slabs_partial; /* partial list first, better asm code */
538 struct list_head slabs_full;
539 struct list_head slabs_free;
540 unsigned long total_slabs; /* length of all slab lists */
541 unsigned long free_slabs; /* length of free slab list only */
542 unsigned long free_objects;
543 unsigned int free_limit;
544 unsigned int colour_next; /* Per-node cache coloring */
545 struct array_cache *shared; /* shared per node */
546 struct alien_cache **alien; /* on other nodes */
547 unsigned long next_reap; /* updated without locking */
548 int free_touched; /* updated without locking */
549#endif
550
551#ifdef CONFIG_SLUB
552 unsigned long nr_partial;
553 struct list_head partial;
554#ifdef CONFIG_SLUB_DEBUG
555 atomic_long_t nr_slabs;
556 atomic_long_t total_objects;
557 struct list_head full;
558#endif
559#endif
560
561};
562
563static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
564{
565 return s->node[node];
566}
567
568/*
569 * Iterator over all nodes. The body will be executed for each node that has
570 * a kmem_cache_node structure allocated (which is true for all online nodes)
571 */
572#define for_each_kmem_cache_node(__s, __node, __n) \
573 for (__node = 0; __node < nr_node_ids; __node++) \
574 if ((__n = get_node(__s, __node)))
575
576#endif
577
578void *slab_start(struct seq_file *m, loff_t *pos);
579void *slab_next(struct seq_file *m, void *p, loff_t *pos);
580void slab_stop(struct seq_file *m, void *p);
581int memcg_slab_show(struct seq_file *m, void *p);
582
583#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
584void dump_unreclaimable_slab(void);
585#else
586static inline void dump_unreclaimable_slab(void)
587{
588}
589#endif
590
591void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
592
593#ifdef CONFIG_SLAB_FREELIST_RANDOM
594int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
595 gfp_t gfp);
596void cache_random_seq_destroy(struct kmem_cache *cachep);
597#else
598static inline int cache_random_seq_create(struct kmem_cache *cachep,
599 unsigned int count, gfp_t gfp)
600{
601 return 0;
602}
603static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
604#endif /* CONFIG_SLAB_FREELIST_RANDOM */
605
606static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
607{
608 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
609 &init_on_alloc)) {
610 if (c->ctor)
611 return false;
612 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
613 return flags & __GFP_ZERO;
614 return true;
615 }
616 return flags & __GFP_ZERO;
617}
618
619static inline bool slab_want_init_on_free(struct kmem_cache *c)
620{
621 if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
622 &init_on_free))
623 return !(c->ctor ||
624 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
625 return false;
626}
627
628#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
629void debugfs_slab_release(struct kmem_cache *);
630#else
631static inline void debugfs_slab_release(struct kmem_cache *s) { }
632#endif
633
634#ifdef CONFIG_PRINTK
635#define KS_ADDRS_COUNT 16
636struct kmem_obj_info {
637 void *kp_ptr;
638 struct page *kp_page;
639 void *kp_objp;
640 unsigned long kp_data_offset;
641 struct kmem_cache *kp_slab_cache;
642 void *kp_ret;
643 void *kp_stack[KS_ADDRS_COUNT];
644 void *kp_free_stack[KS_ADDRS_COUNT];
645};
646void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page);
647#endif
648
649#endif /* MM_SLAB_H */