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1#ifndef MM_SLAB_H
2#define MM_SLAB_H
3/*
4 * Internal slab definitions
5 */
6
7#ifdef CONFIG_SLOB
8/*
9 * Common fields provided in kmem_cache by all slab allocators
10 * This struct is either used directly by the allocator (SLOB)
11 * or the allocator must include definitions for all fields
12 * provided in kmem_cache_common in their definition of kmem_cache.
13 *
14 * Once we can do anonymous structs (C11 standard) we could put a
15 * anonymous struct definition in these allocators so that the
16 * separate allocations in the kmem_cache structure of SLAB and
17 * SLUB is no longer needed.
18 */
19struct kmem_cache {
20 unsigned int object_size;/* The original size of the object */
21 unsigned int size; /* The aligned/padded/added on size */
22 unsigned int align; /* Alignment as calculated */
23 unsigned long flags; /* Active flags on the slab */
24 const char *name; /* Slab name for sysfs */
25 int refcount; /* Use counter */
26 void (*ctor)(void *); /* Called on object slot creation */
27 struct list_head list; /* List of all slab caches on the system */
28};
29
30#endif /* CONFIG_SLOB */
31
32#ifdef CONFIG_SLAB
33#include <linux/slab_def.h>
34#endif
35
36#ifdef CONFIG_SLUB
37#include <linux/slub_def.h>
38#endif
39
40#include <linux/memcontrol.h>
41#include <linux/fault-inject.h>
42#include <linux/kmemcheck.h>
43#include <linux/kasan.h>
44#include <linux/kmemleak.h>
45
46/*
47 * State of the slab allocator.
48 *
49 * This is used to describe the states of the allocator during bootup.
50 * Allocators use this to gradually bootstrap themselves. Most allocators
51 * have the problem that the structures used for managing slab caches are
52 * allocated from slab caches themselves.
53 */
54enum slab_state {
55 DOWN, /* No slab functionality yet */
56 PARTIAL, /* SLUB: kmem_cache_node available */
57 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
58 UP, /* Slab caches usable but not all extras yet */
59 FULL /* Everything is working */
60};
61
62extern enum slab_state slab_state;
63
64/* The slab cache mutex protects the management structures during changes */
65extern struct mutex slab_mutex;
66
67/* The list of all slab caches on the system */
68extern struct list_head slab_caches;
69
70/* The slab cache that manages slab cache information */
71extern struct kmem_cache *kmem_cache;
72
73unsigned long calculate_alignment(unsigned long flags,
74 unsigned long align, unsigned long size);
75
76#ifndef CONFIG_SLOB
77/* Kmalloc array related functions */
78void setup_kmalloc_cache_index_table(void);
79void create_kmalloc_caches(unsigned long);
80
81/* Find the kmalloc slab corresponding for a certain size */
82struct kmem_cache *kmalloc_slab(size_t, gfp_t);
83#endif
84
85
86/* Functions provided by the slab allocators */
87extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
88
89extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
90 unsigned long flags);
91extern void create_boot_cache(struct kmem_cache *, const char *name,
92 size_t size, unsigned long flags);
93
94int slab_unmergeable(struct kmem_cache *s);
95struct kmem_cache *find_mergeable(size_t size, size_t align,
96 unsigned long flags, const char *name, void (*ctor)(void *));
97#ifndef CONFIG_SLOB
98struct kmem_cache *
99__kmem_cache_alias(const char *name, size_t size, size_t align,
100 unsigned long flags, void (*ctor)(void *));
101
102unsigned long kmem_cache_flags(unsigned long object_size,
103 unsigned long flags, const char *name,
104 void (*ctor)(void *));
105#else
106static inline struct kmem_cache *
107__kmem_cache_alias(const char *name, size_t size, size_t align,
108 unsigned long flags, void (*ctor)(void *))
109{ return NULL; }
110
111static inline unsigned long kmem_cache_flags(unsigned long object_size,
112 unsigned long flags, const char *name,
113 void (*ctor)(void *))
114{
115 return flags;
116}
117#endif
118
119
120/* Legal flag mask for kmem_cache_create(), for various configurations */
121#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
122 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
123
124#if defined(CONFIG_DEBUG_SLAB)
125#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
126#elif defined(CONFIG_SLUB_DEBUG)
127#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
128 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
129#else
130#define SLAB_DEBUG_FLAGS (0)
131#endif
132
133#if defined(CONFIG_SLAB)
134#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
135 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
136 SLAB_NOTRACK | SLAB_ACCOUNT)
137#elif defined(CONFIG_SLUB)
138#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
139 SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT)
140#else
141#define SLAB_CACHE_FLAGS (0)
142#endif
143
144#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
145
146int __kmem_cache_shutdown(struct kmem_cache *);
147void __kmem_cache_release(struct kmem_cache *);
148int __kmem_cache_shrink(struct kmem_cache *, bool);
149void slab_kmem_cache_release(struct kmem_cache *);
150
151struct seq_file;
152struct file;
153
154struct slabinfo {
155 unsigned long active_objs;
156 unsigned long num_objs;
157 unsigned long active_slabs;
158 unsigned long num_slabs;
159 unsigned long shared_avail;
160 unsigned int limit;
161 unsigned int batchcount;
162 unsigned int shared;
163 unsigned int objects_per_slab;
164 unsigned int cache_order;
165};
166
167void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
168void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
169ssize_t slabinfo_write(struct file *file, const char __user *buffer,
170 size_t count, loff_t *ppos);
171
172/*
173 * Generic implementation of bulk operations
174 * These are useful for situations in which the allocator cannot
175 * perform optimizations. In that case segments of the object listed
176 * may be allocated or freed using these operations.
177 */
178void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
179int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
180
181#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
182/*
183 * Iterate over all memcg caches of the given root cache. The caller must hold
184 * slab_mutex.
185 */
186#define for_each_memcg_cache(iter, root) \
187 list_for_each_entry(iter, &(root)->memcg_params.list, \
188 memcg_params.list)
189
190static inline bool is_root_cache(struct kmem_cache *s)
191{
192 return s->memcg_params.is_root_cache;
193}
194
195static inline bool slab_equal_or_root(struct kmem_cache *s,
196 struct kmem_cache *p)
197{
198 return p == s || p == s->memcg_params.root_cache;
199}
200
201/*
202 * We use suffixes to the name in memcg because we can't have caches
203 * created in the system with the same name. But when we print them
204 * locally, better refer to them with the base name
205 */
206static inline const char *cache_name(struct kmem_cache *s)
207{
208 if (!is_root_cache(s))
209 s = s->memcg_params.root_cache;
210 return s->name;
211}
212
213/*
214 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
215 * That said the caller must assure the memcg's cache won't go away by either
216 * taking a css reference to the owner cgroup, or holding the slab_mutex.
217 */
218static inline struct kmem_cache *
219cache_from_memcg_idx(struct kmem_cache *s, int idx)
220{
221 struct kmem_cache *cachep;
222 struct memcg_cache_array *arr;
223
224 rcu_read_lock();
225 arr = rcu_dereference(s->memcg_params.memcg_caches);
226
227 /*
228 * Make sure we will access the up-to-date value. The code updating
229 * memcg_caches issues a write barrier to match this (see
230 * memcg_create_kmem_cache()).
231 */
232 cachep = lockless_dereference(arr->entries[idx]);
233 rcu_read_unlock();
234
235 return cachep;
236}
237
238static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
239{
240 if (is_root_cache(s))
241 return s;
242 return s->memcg_params.root_cache;
243}
244
245static __always_inline int memcg_charge_slab(struct page *page,
246 gfp_t gfp, int order,
247 struct kmem_cache *s)
248{
249 int ret;
250
251 if (!memcg_kmem_enabled())
252 return 0;
253 if (is_root_cache(s))
254 return 0;
255
256 ret = __memcg_kmem_charge_memcg(page, gfp, order,
257 s->memcg_params.memcg);
258 if (ret)
259 return ret;
260
261 memcg_kmem_update_page_stat(page,
262 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
263 MEMCG_SLAB_RECLAIMABLE : MEMCG_SLAB_UNRECLAIMABLE,
264 1 << order);
265 return 0;
266}
267
268static __always_inline void memcg_uncharge_slab(struct page *page, int order,
269 struct kmem_cache *s)
270{
271 memcg_kmem_update_page_stat(page,
272 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
273 MEMCG_SLAB_RECLAIMABLE : MEMCG_SLAB_UNRECLAIMABLE,
274 -(1 << order));
275 memcg_kmem_uncharge(page, order);
276}
277
278extern void slab_init_memcg_params(struct kmem_cache *);
279
280#else /* CONFIG_MEMCG && !CONFIG_SLOB */
281
282#define for_each_memcg_cache(iter, root) \
283 for ((void)(iter), (void)(root); 0; )
284
285static inline bool is_root_cache(struct kmem_cache *s)
286{
287 return true;
288}
289
290static inline bool slab_equal_or_root(struct kmem_cache *s,
291 struct kmem_cache *p)
292{
293 return true;
294}
295
296static inline const char *cache_name(struct kmem_cache *s)
297{
298 return s->name;
299}
300
301static inline struct kmem_cache *
302cache_from_memcg_idx(struct kmem_cache *s, int idx)
303{
304 return NULL;
305}
306
307static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
308{
309 return s;
310}
311
312static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
313 struct kmem_cache *s)
314{
315 return 0;
316}
317
318static inline void memcg_uncharge_slab(struct page *page, int order,
319 struct kmem_cache *s)
320{
321}
322
323static inline void slab_init_memcg_params(struct kmem_cache *s)
324{
325}
326#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
327
328static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
329{
330 struct kmem_cache *cachep;
331 struct page *page;
332
333 /*
334 * When kmemcg is not being used, both assignments should return the
335 * same value. but we don't want to pay the assignment price in that
336 * case. If it is not compiled in, the compiler should be smart enough
337 * to not do even the assignment. In that case, slab_equal_or_root
338 * will also be a constant.
339 */
340 if (!memcg_kmem_enabled() &&
341 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
342 return s;
343
344 page = virt_to_head_page(x);
345 cachep = page->slab_cache;
346 if (slab_equal_or_root(cachep, s))
347 return cachep;
348
349 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
350 __func__, s->name, cachep->name);
351 WARN_ON_ONCE(1);
352 return s;
353}
354
355static inline size_t slab_ksize(const struct kmem_cache *s)
356{
357#ifndef CONFIG_SLUB
358 return s->object_size;
359
360#else /* CONFIG_SLUB */
361# ifdef CONFIG_SLUB_DEBUG
362 /*
363 * Debugging requires use of the padding between object
364 * and whatever may come after it.
365 */
366 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
367 return s->object_size;
368# endif
369 /*
370 * If we have the need to store the freelist pointer
371 * back there or track user information then we can
372 * only use the space before that information.
373 */
374 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
375 return s->inuse;
376 /*
377 * Else we can use all the padding etc for the allocation
378 */
379 return s->size;
380#endif
381}
382
383static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
384 gfp_t flags)
385{
386 flags &= gfp_allowed_mask;
387 lockdep_trace_alloc(flags);
388 might_sleep_if(gfpflags_allow_blocking(flags));
389
390 if (should_failslab(s, flags))
391 return NULL;
392
393 return memcg_kmem_get_cache(s, flags);
394}
395
396static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
397 size_t size, void **p)
398{
399 size_t i;
400
401 flags &= gfp_allowed_mask;
402 for (i = 0; i < size; i++) {
403 void *object = p[i];
404
405 kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
406 kmemleak_alloc_recursive(object, s->object_size, 1,
407 s->flags, flags);
408 kasan_slab_alloc(s, object, flags);
409 }
410 memcg_kmem_put_cache(s);
411}
412
413#ifndef CONFIG_SLOB
414/*
415 * The slab lists for all objects.
416 */
417struct kmem_cache_node {
418 spinlock_t list_lock;
419
420#ifdef CONFIG_SLAB
421 struct list_head slabs_partial; /* partial list first, better asm code */
422 struct list_head slabs_full;
423 struct list_head slabs_free;
424 unsigned long free_objects;
425 unsigned int free_limit;
426 unsigned int colour_next; /* Per-node cache coloring */
427 struct array_cache *shared; /* shared per node */
428 struct alien_cache **alien; /* on other nodes */
429 unsigned long next_reap; /* updated without locking */
430 int free_touched; /* updated without locking */
431#endif
432
433#ifdef CONFIG_SLUB
434 unsigned long nr_partial;
435 struct list_head partial;
436#ifdef CONFIG_SLUB_DEBUG
437 atomic_long_t nr_slabs;
438 atomic_long_t total_objects;
439 struct list_head full;
440#endif
441#endif
442
443};
444
445static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
446{
447 return s->node[node];
448}
449
450/*
451 * Iterator over all nodes. The body will be executed for each node that has
452 * a kmem_cache_node structure allocated (which is true for all online nodes)
453 */
454#define for_each_kmem_cache_node(__s, __node, __n) \
455 for (__node = 0; __node < nr_node_ids; __node++) \
456 if ((__n = get_node(__s, __node)))
457
458#endif
459
460void *slab_start(struct seq_file *m, loff_t *pos);
461void *slab_next(struct seq_file *m, void *p, loff_t *pos);
462void slab_stop(struct seq_file *m, void *p);
463int memcg_slab_show(struct seq_file *m, void *p);
464
465#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 */