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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#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;
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
92
93/* Functions provided by the slab allocators */
94int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
95
96struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
97 slab_flags_t flags, unsigned int useroffset,
98 unsigned int usersize);
99extern void create_boot_cache(struct kmem_cache *, const char *name,
100 unsigned int size, slab_flags_t flags,
101 unsigned int useroffset, unsigned int usersize);
102
103int slab_unmergeable(struct kmem_cache *s);
104struct kmem_cache *find_mergeable(unsigned size, unsigned align,
105 slab_flags_t flags, const char *name, void (*ctor)(void *));
106#ifndef CONFIG_SLOB
107struct kmem_cache *
108__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
109 slab_flags_t flags, void (*ctor)(void *));
110
111slab_flags_t kmem_cache_flags(unsigned int object_size,
112 slab_flags_t flags, const char *name,
113 void (*ctor)(void *));
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 void (*ctor)(void *))
123{
124 return flags;
125}
126#endif
127
128
129/* Legal flag mask for kmem_cache_create(), for various configurations */
130#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | 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 __kmemcg_cache_deactivate(struct kmem_cache *s);
174void slab_kmem_cache_release(struct kmem_cache *);
175
176struct seq_file;
177struct file;
178
179struct slabinfo {
180 unsigned long active_objs;
181 unsigned long num_objs;
182 unsigned long active_slabs;
183 unsigned long num_slabs;
184 unsigned long shared_avail;
185 unsigned int limit;
186 unsigned int batchcount;
187 unsigned int shared;
188 unsigned int objects_per_slab;
189 unsigned int cache_order;
190};
191
192void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
193void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
194ssize_t slabinfo_write(struct file *file, const char __user *buffer,
195 size_t count, loff_t *ppos);
196
197/*
198 * Generic implementation of bulk operations
199 * These are useful for situations in which the allocator cannot
200 * perform optimizations. In that case segments of the object listed
201 * may be allocated or freed using these operations.
202 */
203void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
204int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
205
206#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
207
208/* List of all root caches. */
209extern struct list_head slab_root_caches;
210#define root_caches_node memcg_params.__root_caches_node
211
212/*
213 * Iterate over all memcg caches of the given root cache. The caller must hold
214 * slab_mutex.
215 */
216#define for_each_memcg_cache(iter, root) \
217 list_for_each_entry(iter, &(root)->memcg_params.children, \
218 memcg_params.children_node)
219
220static inline bool is_root_cache(struct kmem_cache *s)
221{
222 return !s->memcg_params.root_cache;
223}
224
225static inline bool slab_equal_or_root(struct kmem_cache *s,
226 struct kmem_cache *p)
227{
228 return p == s || p == s->memcg_params.root_cache;
229}
230
231/*
232 * We use suffixes to the name in memcg because we can't have caches
233 * created in the system with the same name. But when we print them
234 * locally, better refer to them with the base name
235 */
236static inline const char *cache_name(struct kmem_cache *s)
237{
238 if (!is_root_cache(s))
239 s = s->memcg_params.root_cache;
240 return s->name;
241}
242
243/*
244 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
245 * That said the caller must assure the memcg's cache won't go away by either
246 * taking a css reference to the owner cgroup, or holding the slab_mutex.
247 */
248static inline struct kmem_cache *
249cache_from_memcg_idx(struct kmem_cache *s, int idx)
250{
251 struct kmem_cache *cachep;
252 struct memcg_cache_array *arr;
253
254 rcu_read_lock();
255 arr = rcu_dereference(s->memcg_params.memcg_caches);
256
257 /*
258 * Make sure we will access the up-to-date value. The code updating
259 * memcg_caches issues a write barrier to match this (see
260 * memcg_create_kmem_cache()).
261 */
262 cachep = READ_ONCE(arr->entries[idx]);
263 rcu_read_unlock();
264
265 return cachep;
266}
267
268static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
269{
270 if (is_root_cache(s))
271 return s;
272 return s->memcg_params.root_cache;
273}
274
275static __always_inline int memcg_charge_slab(struct page *page,
276 gfp_t gfp, int order,
277 struct kmem_cache *s)
278{
279 if (!memcg_kmem_enabled())
280 return 0;
281 if (is_root_cache(s))
282 return 0;
283 return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
284}
285
286static __always_inline void memcg_uncharge_slab(struct page *page, int order,
287 struct kmem_cache *s)
288{
289 if (!memcg_kmem_enabled())
290 return;
291 memcg_kmem_uncharge(page, order);
292}
293
294extern void slab_init_memcg_params(struct kmem_cache *);
295extern void memcg_link_cache(struct kmem_cache *s);
296extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
297 void (*deact_fn)(struct kmem_cache *));
298
299#else /* CONFIG_MEMCG && !CONFIG_SLOB */
300
301/* If !memcg, all caches are root. */
302#define slab_root_caches slab_caches
303#define root_caches_node list
304
305#define for_each_memcg_cache(iter, root) \
306 for ((void)(iter), (void)(root); 0; )
307
308static inline bool is_root_cache(struct kmem_cache *s)
309{
310 return true;
311}
312
313static inline bool slab_equal_or_root(struct kmem_cache *s,
314 struct kmem_cache *p)
315{
316 return true;
317}
318
319static inline const char *cache_name(struct kmem_cache *s)
320{
321 return s->name;
322}
323
324static inline struct kmem_cache *
325cache_from_memcg_idx(struct kmem_cache *s, int idx)
326{
327 return NULL;
328}
329
330static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
331{
332 return s;
333}
334
335static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
336 struct kmem_cache *s)
337{
338 return 0;
339}
340
341static inline void memcg_uncharge_slab(struct page *page, int order,
342 struct kmem_cache *s)
343{
344}
345
346static inline void slab_init_memcg_params(struct kmem_cache *s)
347{
348}
349
350static inline void memcg_link_cache(struct kmem_cache *s)
351{
352}
353
354#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
355
356static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
357{
358 struct kmem_cache *cachep;
359 struct page *page;
360
361 /*
362 * When kmemcg is not being used, both assignments should return the
363 * same value. but we don't want to pay the assignment price in that
364 * case. If it is not compiled in, the compiler should be smart enough
365 * to not do even the assignment. In that case, slab_equal_or_root
366 * will also be a constant.
367 */
368 if (!memcg_kmem_enabled() &&
369 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
370 return s;
371
372 page = virt_to_head_page(x);
373 cachep = page->slab_cache;
374 if (slab_equal_or_root(cachep, s))
375 return cachep;
376
377 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
378 __func__, s->name, cachep->name);
379 WARN_ON_ONCE(1);
380 return s;
381}
382
383static inline size_t slab_ksize(const struct kmem_cache *s)
384{
385#ifndef CONFIG_SLUB
386 return s->object_size;
387
388#else /* CONFIG_SLUB */
389# ifdef CONFIG_SLUB_DEBUG
390 /*
391 * Debugging requires use of the padding between object
392 * and whatever may come after it.
393 */
394 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
395 return s->object_size;
396# endif
397 if (s->flags & SLAB_KASAN)
398 return s->object_size;
399 /*
400 * If we have the need to store the freelist pointer
401 * back there or track user information then we can
402 * only use the space before that information.
403 */
404 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
405 return s->inuse;
406 /*
407 * Else we can use all the padding etc for the allocation
408 */
409 return s->size;
410#endif
411}
412
413static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
414 gfp_t flags)
415{
416 flags &= gfp_allowed_mask;
417
418 fs_reclaim_acquire(flags);
419 fs_reclaim_release(flags);
420
421 might_sleep_if(gfpflags_allow_blocking(flags));
422
423 if (should_failslab(s, flags))
424 return NULL;
425
426 if (memcg_kmem_enabled() &&
427 ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
428 return memcg_kmem_get_cache(s);
429
430 return s;
431}
432
433static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
434 size_t size, void **p)
435{
436 size_t i;
437
438 flags &= gfp_allowed_mask;
439 for (i = 0; i < size; i++) {
440 void *object = p[i];
441
442 kmemleak_alloc_recursive(object, s->object_size, 1,
443 s->flags, flags);
444 kasan_slab_alloc(s, object, flags);
445 }
446
447 if (memcg_kmem_enabled())
448 memcg_kmem_put_cache(s);
449}
450
451#ifndef CONFIG_SLOB
452/*
453 * The slab lists for all objects.
454 */
455struct kmem_cache_node {
456 spinlock_t list_lock;
457
458#ifdef CONFIG_SLAB
459 struct list_head slabs_partial; /* partial list first, better asm code */
460 struct list_head slabs_full;
461 struct list_head slabs_free;
462 unsigned long total_slabs; /* length of all slab lists */
463 unsigned long free_slabs; /* length of free slab list only */
464 unsigned long free_objects;
465 unsigned int free_limit;
466 unsigned int colour_next; /* Per-node cache coloring */
467 struct array_cache *shared; /* shared per node */
468 struct alien_cache **alien; /* on other nodes */
469 unsigned long next_reap; /* updated without locking */
470 int free_touched; /* updated without locking */
471#endif
472
473#ifdef CONFIG_SLUB
474 unsigned long nr_partial;
475 struct list_head partial;
476#ifdef CONFIG_SLUB_DEBUG
477 atomic_long_t nr_slabs;
478 atomic_long_t total_objects;
479 struct list_head full;
480#endif
481#endif
482
483};
484
485static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
486{
487 return s->node[node];
488}
489
490/*
491 * Iterator over all nodes. The body will be executed for each node that has
492 * a kmem_cache_node structure allocated (which is true for all online nodes)
493 */
494#define for_each_kmem_cache_node(__s, __node, __n) \
495 for (__node = 0; __node < nr_node_ids; __node++) \
496 if ((__n = get_node(__s, __node)))
497
498#endif
499
500void *slab_start(struct seq_file *m, loff_t *pos);
501void *slab_next(struct seq_file *m, void *p, loff_t *pos);
502void slab_stop(struct seq_file *m, void *p);
503void *memcg_slab_start(struct seq_file *m, loff_t *pos);
504void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
505void memcg_slab_stop(struct seq_file *m, void *p);
506int memcg_slab_show(struct seq_file *m, void *p);
507
508#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
509void dump_unreclaimable_slab(void);
510#else
511static inline void dump_unreclaimable_slab(void)
512{
513}
514#endif
515
516void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
517
518#ifdef CONFIG_SLAB_FREELIST_RANDOM
519int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
520 gfp_t gfp);
521void cache_random_seq_destroy(struct kmem_cache *cachep);
522#else
523static inline int cache_random_seq_create(struct kmem_cache *cachep,
524 unsigned int count, gfp_t gfp)
525{
526 return 0;
527}
528static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
529#endif /* CONFIG_SLAB_FREELIST_RANDOM */
530
531#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 /*
77 * If slab debugging is enabled then the
78 * frozen bit can be reused to indicate
79 * that the slab was corrupted
80 */
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
93 unsigned int __page_type;
94 atomic_t __page_refcount;
95#ifdef CONFIG_SLAB_OBJ_EXT
96 unsigned long obj_exts;
97#endif
98};
99
100#define SLAB_MATCH(pg, sl) \
101 static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
102SLAB_MATCH(flags, __page_flags);
103SLAB_MATCH(compound_head, slab_cache); /* Ensure bit 0 is clear */
104SLAB_MATCH(_refcount, __page_refcount);
105#ifdef CONFIG_MEMCG
106SLAB_MATCH(memcg_data, obj_exts);
107#elif defined(CONFIG_SLAB_OBJ_EXT)
108SLAB_MATCH(_unused_slab_obj_exts, obj_exts);
109#endif
110#undef SLAB_MATCH
111static_assert(sizeof(struct slab) <= sizeof(struct page));
112#if defined(system_has_freelist_aba)
113static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t)));
114#endif
115
116/**
117 * folio_slab - Converts from folio to slab.
118 * @folio: The folio.
119 *
120 * Currently struct slab is a different representation of a folio where
121 * folio_test_slab() is true.
122 *
123 * Return: The slab which contains this folio.
124 */
125#define folio_slab(folio) (_Generic((folio), \
126 const struct folio *: (const struct slab *)(folio), \
127 struct folio *: (struct slab *)(folio)))
128
129/**
130 * slab_folio - The folio allocated for a slab
131 * @slab: The slab.
132 *
133 * Slabs are allocated as folios that contain the individual objects and are
134 * using some fields in the first struct page of the folio - those fields are
135 * now accessed by struct slab. It is occasionally necessary to convert back to
136 * a folio in order to communicate with the rest of the mm. Please use this
137 * helper function instead of casting yourself, as the implementation may change
138 * in the future.
139 */
140#define slab_folio(s) (_Generic((s), \
141 const struct slab *: (const struct folio *)s, \
142 struct slab *: (struct folio *)s))
143
144/**
145 * page_slab - Converts from first struct page to slab.
146 * @p: The first (either head of compound or single) page of slab.
147 *
148 * A temporary wrapper to convert struct page to struct slab in situations where
149 * we know the page is the compound head, or single order-0 page.
150 *
151 * Long-term ideally everything would work with struct slab directly or go
152 * through folio to struct slab.
153 *
154 * Return: The slab which contains this page
155 */
156#define page_slab(p) (_Generic((p), \
157 const struct page *: (const struct slab *)(p), \
158 struct page *: (struct slab *)(p)))
159
160/**
161 * slab_page - The first struct page allocated for a slab
162 * @slab: The slab.
163 *
164 * A convenience wrapper for converting slab to the first struct page of the
165 * underlying folio, to communicate with code not yet converted to folio or
166 * struct slab.
167 */
168#define slab_page(s) folio_page(slab_folio(s), 0)
169
170/*
171 * If network-based swap is enabled, sl*b must keep track of whether pages
172 * were allocated from pfmemalloc reserves.
173 */
174static inline bool slab_test_pfmemalloc(const struct slab *slab)
175{
176 return folio_test_active(slab_folio(slab));
177}
178
179static inline void slab_set_pfmemalloc(struct slab *slab)
180{
181 folio_set_active(slab_folio(slab));
182}
183
184static inline void slab_clear_pfmemalloc(struct slab *slab)
185{
186 folio_clear_active(slab_folio(slab));
187}
188
189static inline void __slab_clear_pfmemalloc(struct slab *slab)
190{
191 __folio_clear_active(slab_folio(slab));
192}
193
194static inline void *slab_address(const struct slab *slab)
195{
196 return folio_address(slab_folio(slab));
197}
198
199static inline int slab_nid(const struct slab *slab)
200{
201 return folio_nid(slab_folio(slab));
202}
203
204static inline pg_data_t *slab_pgdat(const struct slab *slab)
205{
206 return folio_pgdat(slab_folio(slab));
207}
208
209static inline struct slab *virt_to_slab(const void *addr)
210{
211 struct folio *folio = virt_to_folio(addr);
212
213 if (!folio_test_slab(folio))
214 return NULL;
215
216 return folio_slab(folio);
217}
218
219static inline int slab_order(const struct slab *slab)
220{
221 return folio_order(slab_folio(slab));
222}
223
224static inline size_t slab_size(const struct slab *slab)
225{
226 return PAGE_SIZE << slab_order(slab);
227}
228
229#ifdef CONFIG_SLUB_CPU_PARTIAL
230#define slub_percpu_partial(c) ((c)->partial)
231
232#define slub_set_percpu_partial(c, p) \
233({ \
234 slub_percpu_partial(c) = (p)->next; \
235})
236
237#define slub_percpu_partial_read_once(c) READ_ONCE(slub_percpu_partial(c))
238#else
239#define slub_percpu_partial(c) NULL
240
241#define slub_set_percpu_partial(c, p)
242
243#define slub_percpu_partial_read_once(c) NULL
244#endif // CONFIG_SLUB_CPU_PARTIAL
245
246/*
247 * Word size structure that can be atomically updated or read and that
248 * contains both the order and the number of objects that a slab of the
249 * given order would contain.
250 */
251struct kmem_cache_order_objects {
252 unsigned int x;
253};
254
255/*
256 * Slab cache management.
257 */
258struct kmem_cache {
259#ifndef CONFIG_SLUB_TINY
260 struct kmem_cache_cpu __percpu *cpu_slab;
261#endif
262 /* Used for retrieving partial slabs, etc. */
263 slab_flags_t flags;
264 unsigned long min_partial;
265 unsigned int size; /* Object size including metadata */
266 unsigned int object_size; /* Object size without metadata */
267 struct reciprocal_value reciprocal_size;
268 unsigned int offset; /* Free pointer offset */
269#ifdef CONFIG_SLUB_CPU_PARTIAL
270 /* Number of per cpu partial objects to keep around */
271 unsigned int cpu_partial;
272 /* Number of per cpu partial slabs to keep around */
273 unsigned int cpu_partial_slabs;
274#endif
275 struct kmem_cache_order_objects oo;
276
277 /* Allocation and freeing of slabs */
278 struct kmem_cache_order_objects min;
279 gfp_t allocflags; /* gfp flags to use on each alloc */
280 int refcount; /* Refcount for slab cache destroy */
281 void (*ctor)(void *object); /* Object constructor */
282 unsigned int inuse; /* Offset to metadata */
283 unsigned int align; /* Alignment */
284 unsigned int red_left_pad; /* Left redzone padding size */
285 const char *name; /* Name (only for display!) */
286 struct list_head list; /* List of slab caches */
287#ifdef CONFIG_SYSFS
288 struct kobject kobj; /* For sysfs */
289#endif
290#ifdef CONFIG_SLAB_FREELIST_HARDENED
291 unsigned long random;
292#endif
293
294#ifdef CONFIG_NUMA
295 /*
296 * Defragmentation by allocating from a remote node.
297 */
298 unsigned int remote_node_defrag_ratio;
299#endif
300
301#ifdef CONFIG_SLAB_FREELIST_RANDOM
302 unsigned int *random_seq;
303#endif
304
305#ifdef CONFIG_KASAN_GENERIC
306 struct kasan_cache kasan_info;
307#endif
308
309#ifdef CONFIG_HARDENED_USERCOPY
310 unsigned int useroffset; /* Usercopy region offset */
311 unsigned int usersize; /* Usercopy region size */
312#endif
313
314 struct kmem_cache_node *node[MAX_NUMNODES];
315};
316
317#if defined(CONFIG_SYSFS) && !defined(CONFIG_SLUB_TINY)
318#define SLAB_SUPPORTS_SYSFS 1
319void sysfs_slab_unlink(struct kmem_cache *s);
320void sysfs_slab_release(struct kmem_cache *s);
321#else
322static inline void sysfs_slab_unlink(struct kmem_cache *s) { }
323static inline void sysfs_slab_release(struct kmem_cache *s) { }
324#endif
325
326void *fixup_red_left(struct kmem_cache *s, void *p);
327
328static inline void *nearest_obj(struct kmem_cache *cache,
329 const struct slab *slab, void *x)
330{
331 void *object = x - (x - slab_address(slab)) % cache->size;
332 void *last_object = slab_address(slab) +
333 (slab->objects - 1) * cache->size;
334 void *result = (unlikely(object > last_object)) ? last_object : object;
335
336 result = fixup_red_left(cache, result);
337 return result;
338}
339
340/* Determine object index from a given position */
341static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
342 void *addr, void *obj)
343{
344 return reciprocal_divide(kasan_reset_tag(obj) - addr,
345 cache->reciprocal_size);
346}
347
348static inline unsigned int obj_to_index(const struct kmem_cache *cache,
349 const struct slab *slab, void *obj)
350{
351 if (is_kfence_address(obj))
352 return 0;
353 return __obj_to_index(cache, slab_address(slab), obj);
354}
355
356static inline int objs_per_slab(const struct kmem_cache *cache,
357 const struct slab *slab)
358{
359 return slab->objects;
360}
361
362/*
363 * State of the slab allocator.
364 *
365 * This is used to describe the states of the allocator during bootup.
366 * Allocators use this to gradually bootstrap themselves. Most allocators
367 * have the problem that the structures used for managing slab caches are
368 * allocated from slab caches themselves.
369 */
370enum slab_state {
371 DOWN, /* No slab functionality yet */
372 PARTIAL, /* SLUB: kmem_cache_node available */
373 UP, /* Slab caches usable but not all extras yet */
374 FULL /* Everything is working */
375};
376
377extern enum slab_state slab_state;
378
379/* The slab cache mutex protects the management structures during changes */
380extern struct mutex slab_mutex;
381
382/* The list of all slab caches on the system */
383extern struct list_head slab_caches;
384
385/* The slab cache that manages slab cache information */
386extern struct kmem_cache *kmem_cache;
387
388/* A table of kmalloc cache names and sizes */
389extern const struct kmalloc_info_struct {
390 const char *name[NR_KMALLOC_TYPES];
391 unsigned int size;
392} kmalloc_info[];
393
394/* Kmalloc array related functions */
395void setup_kmalloc_cache_index_table(void);
396void create_kmalloc_caches(void);
397
398extern u8 kmalloc_size_index[24];
399
400static inline unsigned int size_index_elem(unsigned int bytes)
401{
402 return (bytes - 1) / 8;
403}
404
405/*
406 * Find the kmem_cache structure that serves a given size of
407 * allocation
408 *
409 * This assumes size is larger than zero and not larger than
410 * KMALLOC_MAX_CACHE_SIZE and the caller must check that.
411 */
412static inline struct kmem_cache *
413kmalloc_slab(size_t size, kmem_buckets *b, gfp_t flags, unsigned long caller)
414{
415 unsigned int index;
416
417 if (!b)
418 b = &kmalloc_caches[kmalloc_type(flags, caller)];
419 if (size <= 192)
420 index = kmalloc_size_index[size_index_elem(size)];
421 else
422 index = fls(size - 1);
423
424 return (*b)[index];
425}
426
427gfp_t kmalloc_fix_flags(gfp_t flags);
428
429/* Functions provided by the slab allocators */
430int do_kmem_cache_create(struct kmem_cache *s, const char *name,
431 unsigned int size, struct kmem_cache_args *args,
432 slab_flags_t flags);
433
434void __init kmem_cache_init(void);
435extern void create_boot_cache(struct kmem_cache *, const char *name,
436 unsigned int size, slab_flags_t flags,
437 unsigned int useroffset, unsigned int usersize);
438
439int slab_unmergeable(struct kmem_cache *s);
440struct kmem_cache *find_mergeable(unsigned size, unsigned align,
441 slab_flags_t flags, const char *name, void (*ctor)(void *));
442struct kmem_cache *
443__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
444 slab_flags_t flags, void (*ctor)(void *));
445
446slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name);
447
448static inline bool is_kmalloc_cache(struct kmem_cache *s)
449{
450 return (s->flags & SLAB_KMALLOC);
451}
452
453static inline bool is_kmalloc_normal(struct kmem_cache *s)
454{
455 if (!is_kmalloc_cache(s))
456 return false;
457 return !(s->flags & (SLAB_CACHE_DMA|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT));
458}
459
460/* Legal flag mask for kmem_cache_create(), for various configurations */
461#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
462 SLAB_CACHE_DMA32 | SLAB_PANIC | \
463 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
464
465#ifdef CONFIG_SLUB_DEBUG
466#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
467 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
468#else
469#define SLAB_DEBUG_FLAGS (0)
470#endif
471
472#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
473 SLAB_TEMPORARY | SLAB_ACCOUNT | \
474 SLAB_NO_USER_FLAGS | SLAB_KMALLOC | SLAB_NO_MERGE)
475
476/* Common flags available with current configuration */
477#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
478
479/* Common flags permitted for kmem_cache_create */
480#define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
481 SLAB_RED_ZONE | \
482 SLAB_POISON | \
483 SLAB_STORE_USER | \
484 SLAB_TRACE | \
485 SLAB_CONSISTENCY_CHECKS | \
486 SLAB_NOLEAKTRACE | \
487 SLAB_RECLAIM_ACCOUNT | \
488 SLAB_TEMPORARY | \
489 SLAB_ACCOUNT | \
490 SLAB_KMALLOC | \
491 SLAB_NO_MERGE | \
492 SLAB_NO_USER_FLAGS)
493
494bool __kmem_cache_empty(struct kmem_cache *);
495int __kmem_cache_shutdown(struct kmem_cache *);
496void __kmem_cache_release(struct kmem_cache *);
497int __kmem_cache_shrink(struct kmem_cache *);
498void slab_kmem_cache_release(struct kmem_cache *);
499
500struct seq_file;
501struct file;
502
503struct slabinfo {
504 unsigned long active_objs;
505 unsigned long num_objs;
506 unsigned long active_slabs;
507 unsigned long num_slabs;
508 unsigned long shared_avail;
509 unsigned int limit;
510 unsigned int batchcount;
511 unsigned int shared;
512 unsigned int objects_per_slab;
513 unsigned int cache_order;
514};
515
516void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
517
518#ifdef CONFIG_SLUB_DEBUG
519#ifdef CONFIG_SLUB_DEBUG_ON
520DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
521#else
522DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
523#endif
524extern void print_tracking(struct kmem_cache *s, void *object);
525long validate_slab_cache(struct kmem_cache *s);
526static inline bool __slub_debug_enabled(void)
527{
528 return static_branch_unlikely(&slub_debug_enabled);
529}
530#else
531static inline void print_tracking(struct kmem_cache *s, void *object)
532{
533}
534static inline bool __slub_debug_enabled(void)
535{
536 return false;
537}
538#endif
539
540/*
541 * Returns true if any of the specified slab_debug flags is enabled for the
542 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
543 * the static key.
544 */
545static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
546{
547 if (IS_ENABLED(CONFIG_SLUB_DEBUG))
548 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
549 if (__slub_debug_enabled())
550 return s->flags & flags;
551 return false;
552}
553
554#if IS_ENABLED(CONFIG_SLUB_DEBUG) && IS_ENABLED(CONFIG_KUNIT)
555bool slab_in_kunit_test(void);
556#else
557static inline bool slab_in_kunit_test(void) { return false; }
558#endif
559
560#ifdef CONFIG_SLAB_OBJ_EXT
561
562/*
563 * slab_obj_exts - get the pointer to the slab object extension vector
564 * associated with a slab.
565 * @slab: a pointer to the slab struct
566 *
567 * Returns a pointer to the object extension vector associated with the slab,
568 * or NULL if no such vector has been associated yet.
569 */
570static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
571{
572 unsigned long obj_exts = READ_ONCE(slab->obj_exts);
573
574#ifdef CONFIG_MEMCG
575 VM_BUG_ON_PAGE(obj_exts && !(obj_exts & MEMCG_DATA_OBJEXTS),
576 slab_page(slab));
577 VM_BUG_ON_PAGE(obj_exts & MEMCG_DATA_KMEM, slab_page(slab));
578#endif
579 return (struct slabobj_ext *)(obj_exts & ~OBJEXTS_FLAGS_MASK);
580}
581
582int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
583 gfp_t gfp, bool new_slab);
584
585#else /* CONFIG_SLAB_OBJ_EXT */
586
587static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
588{
589 return NULL;
590}
591
592#endif /* CONFIG_SLAB_OBJ_EXT */
593
594static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
595{
596 return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
597 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
598}
599
600#ifdef CONFIG_MEMCG
601bool __memcg_slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
602 gfp_t flags, size_t size, void **p);
603void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
604 void **p, int objects, struct slabobj_ext *obj_exts);
605#endif
606
607size_t __ksize(const void *objp);
608
609static inline size_t slab_ksize(const struct kmem_cache *s)
610{
611#ifdef CONFIG_SLUB_DEBUG
612 /*
613 * Debugging requires use of the padding between object
614 * and whatever may come after it.
615 */
616 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
617 return s->object_size;
618#endif
619 if (s->flags & SLAB_KASAN)
620 return s->object_size;
621 /*
622 * If we have the need to store the freelist pointer
623 * back there or track user information then we can
624 * only use the space before that information.
625 */
626 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
627 return s->inuse;
628 /*
629 * Else we can use all the padding etc for the allocation
630 */
631 return s->size;
632}
633
634#ifdef CONFIG_SLUB_DEBUG
635void dump_unreclaimable_slab(void);
636#else
637static inline void dump_unreclaimable_slab(void)
638{
639}
640#endif
641
642void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
643
644#ifdef CONFIG_SLAB_FREELIST_RANDOM
645int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
646 gfp_t gfp);
647void cache_random_seq_destroy(struct kmem_cache *cachep);
648#else
649static inline int cache_random_seq_create(struct kmem_cache *cachep,
650 unsigned int count, gfp_t gfp)
651{
652 return 0;
653}
654static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
655#endif /* CONFIG_SLAB_FREELIST_RANDOM */
656
657static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
658{
659 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
660 &init_on_alloc)) {
661 if (c->ctor)
662 return false;
663 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
664 return flags & __GFP_ZERO;
665 return true;
666 }
667 return flags & __GFP_ZERO;
668}
669
670static inline bool slab_want_init_on_free(struct kmem_cache *c)
671{
672 if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
673 &init_on_free))
674 return !(c->ctor ||
675 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
676 return false;
677}
678
679#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
680void debugfs_slab_release(struct kmem_cache *);
681#else
682static inline void debugfs_slab_release(struct kmem_cache *s) { }
683#endif
684
685#ifdef CONFIG_PRINTK
686#define KS_ADDRS_COUNT 16
687struct kmem_obj_info {
688 void *kp_ptr;
689 struct slab *kp_slab;
690 void *kp_objp;
691 unsigned long kp_data_offset;
692 struct kmem_cache *kp_slab_cache;
693 void *kp_ret;
694 void *kp_stack[KS_ADDRS_COUNT];
695 void *kp_free_stack[KS_ADDRS_COUNT];
696};
697void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
698#endif
699
700void __check_heap_object(const void *ptr, unsigned long n,
701 const struct slab *slab, bool to_user);
702
703static inline bool slub_debug_orig_size(struct kmem_cache *s)
704{
705 return (kmem_cache_debug_flags(s, SLAB_STORE_USER) &&
706 (s->flags & SLAB_KMALLOC));
707}
708
709#ifdef CONFIG_SLUB_DEBUG
710void skip_orig_size_check(struct kmem_cache *s, const void *object);
711#endif
712
713#endif /* MM_SLAB_H */