linux/mm/slab.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef MM_SLAB_H
   3#define MM_SLAB_H
   4/*
   5 * Internal slab definitions
   6 */
   7
   8/* Reuses the bits in struct page */
   9struct slab {
  10        unsigned long __page_flags;
  11
  12#if defined(CONFIG_SLAB)
  13
  14        union {
  15                struct list_head slab_list;
  16                struct rcu_head rcu_head;
  17        };
  18        struct kmem_cache *slab_cache;
  19        void *freelist; /* array of free object indexes */
  20        void *s_mem;    /* first object */
  21        unsigned int active;
  22
  23#elif defined(CONFIG_SLUB)
  24
  25        union {
  26                struct list_head slab_list;
  27                struct rcu_head rcu_head;
  28#ifdef CONFIG_SLUB_CPU_PARTIAL
  29                struct {
  30                        struct slab *next;
  31                        int slabs;      /* Nr of slabs left */
  32                };
  33#endif
  34        };
  35        struct kmem_cache *slab_cache;
  36        /* Double-word boundary */
  37        void *freelist;         /* first free object */
  38        union {
  39                unsigned long counters;
  40                struct {
  41                        unsigned inuse:16;
  42                        unsigned objects:15;
  43                        unsigned frozen:1;
  44                };
  45        };
  46        unsigned int __unused;
  47
  48#elif defined(CONFIG_SLOB)
  49
  50        struct list_head slab_list;
  51        void *__unused_1;
  52        void *freelist;         /* first free block */
  53        long units;
  54        unsigned int __unused_2;
  55
  56#else
  57#error "Unexpected slab allocator configured"
  58#endif
  59
  60        atomic_t __page_refcount;
  61#ifdef CONFIG_MEMCG
  62        unsigned long memcg_data;
  63#endif
  64};
  65
  66#define SLAB_MATCH(pg, sl)                                              \
  67        static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
  68SLAB_MATCH(flags, __page_flags);
  69SLAB_MATCH(compound_head, slab_list);   /* Ensure bit 0 is clear */
  70#ifndef CONFIG_SLOB
  71SLAB_MATCH(rcu_head, rcu_head);
  72#endif
  73SLAB_MATCH(_refcount, __page_refcount);
  74#ifdef CONFIG_MEMCG
  75SLAB_MATCH(memcg_data, memcg_data);
  76#endif
  77#undef SLAB_MATCH
  78static_assert(sizeof(struct slab) <= sizeof(struct page));
  79
  80/**
  81 * folio_slab - Converts from folio to slab.
  82 * @folio: The folio.
  83 *
  84 * Currently struct slab is a different representation of a folio where
  85 * folio_test_slab() is true.
  86 *
  87 * Return: The slab which contains this folio.
  88 */
  89#define folio_slab(folio)       (_Generic((folio),                      \
  90        const struct folio *:   (const struct slab *)(folio),           \
  91        struct folio *:         (struct slab *)(folio)))
  92
  93/**
  94 * slab_folio - The folio allocated for a slab
  95 * @slab: The slab.
  96 *
  97 * Slabs are allocated as folios that contain the individual objects and are
  98 * using some fields in the first struct page of the folio - those fields are
  99 * now accessed by struct slab. It is occasionally necessary to convert back to
 100 * a folio in order to communicate with the rest of the mm.  Please use this
 101 * helper function instead of casting yourself, as the implementation may change
 102 * in the future.
 103 */
 104#define slab_folio(s)           (_Generic((s),                          \
 105        const struct slab *:    (const struct folio *)s,                \
 106        struct slab *:          (struct folio *)s))
 107
 108/**
 109 * page_slab - Converts from first struct page to slab.
 110 * @p: The first (either head of compound or single) page of slab.
 111 *
 112 * A temporary wrapper to convert struct page to struct slab in situations where
 113 * we know the page is the compound head, or single order-0 page.
 114 *
 115 * Long-term ideally everything would work with struct slab directly or go
 116 * through folio to struct slab.
 117 *
 118 * Return: The slab which contains this page
 119 */
 120#define page_slab(p)            (_Generic((p),                          \
 121        const struct page *:    (const struct slab *)(p),               \
 122        struct page *:          (struct slab *)(p)))
 123
 124/**
 125 * slab_page - The first struct page allocated for a slab
 126 * @slab: The slab.
 127 *
 128 * A convenience wrapper for converting slab to the first struct page of the
 129 * underlying folio, to communicate with code not yet converted to folio or
 130 * struct slab.
 131 */
 132#define slab_page(s) folio_page(slab_folio(s), 0)
 133
 134/*
 135 * If network-based swap is enabled, sl*b must keep track of whether pages
 136 * were allocated from pfmemalloc reserves.
 137 */
 138static inline bool slab_test_pfmemalloc(const struct slab *slab)
 139{
 140        return folio_test_active((struct folio *)slab_folio(slab));
 141}
 142
 143static inline void slab_set_pfmemalloc(struct slab *slab)
 144{
 145        folio_set_active(slab_folio(slab));
 146}
 147
 148static inline void slab_clear_pfmemalloc(struct slab *slab)
 149{
 150        folio_clear_active(slab_folio(slab));
 151}
 152
 153static inline void __slab_clear_pfmemalloc(struct slab *slab)
 154{
 155        __folio_clear_active(slab_folio(slab));
 156}
 157
 158static inline void *slab_address(const struct slab *slab)
 159{
 160        return folio_address(slab_folio(slab));
 161}
 162
 163static inline int slab_nid(const struct slab *slab)
 164{
 165        return folio_nid(slab_folio(slab));
 166}
 167
 168static inline pg_data_t *slab_pgdat(const struct slab *slab)
 169{
 170        return folio_pgdat(slab_folio(slab));
 171}
 172
 173static inline struct slab *virt_to_slab(const void *addr)
 174{
 175        struct folio *folio = virt_to_folio(addr);
 176
 177        if (!folio_test_slab(folio))
 178                return NULL;
 179
 180        return folio_slab(folio);
 181}
 182
 183static inline int slab_order(const struct slab *slab)
 184{
 185        return folio_order((struct folio *)slab_folio(slab));
 186}
 187
 188static inline size_t slab_size(const struct slab *slab)
 189{
 190        return PAGE_SIZE << slab_order(slab);
 191}
 192
 193#ifdef CONFIG_SLOB
 194/*
 195 * Common fields provided in kmem_cache by all slab allocators
 196 * This struct is either used directly by the allocator (SLOB)
 197 * or the allocator must include definitions for all fields
 198 * provided in kmem_cache_common in their definition of kmem_cache.
 199 *
 200 * Once we can do anonymous structs (C11 standard) we could put a
 201 * anonymous struct definition in these allocators so that the
 202 * separate allocations in the kmem_cache structure of SLAB and
 203 * SLUB is no longer needed.
 204 */
 205struct kmem_cache {
 206        unsigned int object_size;/* The original size of the object */
 207        unsigned int size;      /* The aligned/padded/added on size  */
 208        unsigned int align;     /* Alignment as calculated */
 209        slab_flags_t flags;     /* Active flags on the slab */
 210        unsigned int useroffset;/* Usercopy region offset */
 211        unsigned int usersize;  /* Usercopy region size */
 212        const char *name;       /* Slab name for sysfs */
 213        int refcount;           /* Use counter */
 214        void (*ctor)(void *);   /* Called on object slot creation */
 215        struct list_head list;  /* List of all slab caches on the system */
 216};
 217
 218#endif /* CONFIG_SLOB */
 219
 220#ifdef CONFIG_SLAB
 221#include <linux/slab_def.h>
 222#endif
 223
 224#ifdef CONFIG_SLUB
 225#include <linux/slub_def.h>
 226#endif
 227
 228#include <linux/memcontrol.h>
 229#include <linux/fault-inject.h>
 230#include <linux/kasan.h>
 231#include <linux/kmemleak.h>
 232#include <linux/random.h>
 233#include <linux/sched/mm.h>
 234#include <linux/list_lru.h>
 235
 236/*
 237 * State of the slab allocator.
 238 *
 239 * This is used to describe the states of the allocator during bootup.
 240 * Allocators use this to gradually bootstrap themselves. Most allocators
 241 * have the problem that the structures used for managing slab caches are
 242 * allocated from slab caches themselves.
 243 */
 244enum slab_state {
 245        DOWN,                   /* No slab functionality yet */
 246        PARTIAL,                /* SLUB: kmem_cache_node available */
 247        PARTIAL_NODE,           /* SLAB: kmalloc size for node struct available */
 248        UP,                     /* Slab caches usable but not all extras yet */
 249        FULL                    /* Everything is working */
 250};
 251
 252extern enum slab_state slab_state;
 253
 254/* The slab cache mutex protects the management structures during changes */
 255extern struct mutex slab_mutex;
 256
 257/* The list of all slab caches on the system */
 258extern struct list_head slab_caches;
 259
 260/* The slab cache that manages slab cache information */
 261extern struct kmem_cache *kmem_cache;
 262
 263/* A table of kmalloc cache names and sizes */
 264extern const struct kmalloc_info_struct {
 265        const char *name[NR_KMALLOC_TYPES];
 266        unsigned int size;
 267} kmalloc_info[];
 268
 269#ifndef CONFIG_SLOB
 270/* Kmalloc array related functions */
 271void setup_kmalloc_cache_index_table(void);
 272void create_kmalloc_caches(slab_flags_t);
 273
 274/* Find the kmalloc slab corresponding for a certain size */
 275struct kmem_cache *kmalloc_slab(size_t, gfp_t);
 276#endif
 277
 278gfp_t kmalloc_fix_flags(gfp_t flags);
 279
 280/* Functions provided by the slab allocators */
 281int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
 282
 283struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
 284                        slab_flags_t flags, unsigned int useroffset,
 285                        unsigned int usersize);
 286extern void create_boot_cache(struct kmem_cache *, const char *name,
 287                        unsigned int size, slab_flags_t flags,
 288                        unsigned int useroffset, unsigned int usersize);
 289
 290int slab_unmergeable(struct kmem_cache *s);
 291struct kmem_cache *find_mergeable(unsigned size, unsigned align,
 292                slab_flags_t flags, const char *name, void (*ctor)(void *));
 293#ifndef CONFIG_SLOB
 294struct kmem_cache *
 295__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
 296                   slab_flags_t flags, void (*ctor)(void *));
 297
 298slab_flags_t kmem_cache_flags(unsigned int object_size,
 299        slab_flags_t flags, const char *name);
 300#else
 301static inline struct kmem_cache *
 302__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
 303                   slab_flags_t flags, void (*ctor)(void *))
 304{ return NULL; }
 305
 306static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
 307        slab_flags_t flags, const char *name)
 308{
 309        return flags;
 310}
 311#endif
 312
 313
 314/* Legal flag mask for kmem_cache_create(), for various configurations */
 315#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
 316                         SLAB_CACHE_DMA32 | SLAB_PANIC | \
 317                         SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
 318
 319#if defined(CONFIG_DEBUG_SLAB)
 320#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
 321#elif defined(CONFIG_SLUB_DEBUG)
 322#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
 323                          SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
 324#else
 325#define SLAB_DEBUG_FLAGS (0)
 326#endif
 327
 328#if defined(CONFIG_SLAB)
 329#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
 330                          SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
 331                          SLAB_ACCOUNT)
 332#elif defined(CONFIG_SLUB)
 333#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
 334                          SLAB_TEMPORARY | SLAB_ACCOUNT | SLAB_NO_USER_FLAGS)
 335#else
 336#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE)
 337#endif
 338
 339/* Common flags available with current configuration */
 340#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
 341
 342/* Common flags permitted for kmem_cache_create */
 343#define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
 344                              SLAB_RED_ZONE | \
 345                              SLAB_POISON | \
 346                              SLAB_STORE_USER | \
 347                              SLAB_TRACE | \
 348                              SLAB_CONSISTENCY_CHECKS | \
 349                              SLAB_MEM_SPREAD | \
 350                              SLAB_NOLEAKTRACE | \
 351                              SLAB_RECLAIM_ACCOUNT | \
 352                              SLAB_TEMPORARY | \
 353                              SLAB_ACCOUNT | \
 354                              SLAB_NO_USER_FLAGS)
 355
 356bool __kmem_cache_empty(struct kmem_cache *);
 357int __kmem_cache_shutdown(struct kmem_cache *);
 358void __kmem_cache_release(struct kmem_cache *);
 359int __kmem_cache_shrink(struct kmem_cache *);
 360void slab_kmem_cache_release(struct kmem_cache *);
 361
 362struct seq_file;
 363struct file;
 364
 365struct slabinfo {
 366        unsigned long active_objs;
 367        unsigned long num_objs;
 368        unsigned long active_slabs;
 369        unsigned long num_slabs;
 370        unsigned long shared_avail;
 371        unsigned int limit;
 372        unsigned int batchcount;
 373        unsigned int shared;
 374        unsigned int objects_per_slab;
 375        unsigned int cache_order;
 376};
 377
 378void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
 379void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
 380ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 381                       size_t count, loff_t *ppos);
 382
 383/*
 384 * Generic implementation of bulk operations
 385 * These are useful for situations in which the allocator cannot
 386 * perform optimizations. In that case segments of the object listed
 387 * may be allocated or freed using these operations.
 388 */
 389void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
 390int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
 391
 392static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
 393{
 394        return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
 395                NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
 396}
 397
 398#ifdef CONFIG_SLUB_DEBUG
 399#ifdef CONFIG_SLUB_DEBUG_ON
 400DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
 401#else
 402DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
 403#endif
 404extern void print_tracking(struct kmem_cache *s, void *object);
 405long validate_slab_cache(struct kmem_cache *s);
 406static inline bool __slub_debug_enabled(void)
 407{
 408        return static_branch_unlikely(&slub_debug_enabled);
 409}
 410#else
 411static inline void print_tracking(struct kmem_cache *s, void *object)
 412{
 413}
 414static inline bool __slub_debug_enabled(void)
 415{
 416        return false;
 417}
 418#endif
 419
 420/*
 421 * Returns true if any of the specified slub_debug flags is enabled for the
 422 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
 423 * the static key.
 424 */
 425static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
 426{
 427        if (IS_ENABLED(CONFIG_SLUB_DEBUG))
 428                VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
 429        if (__slub_debug_enabled())
 430                return s->flags & flags;
 431        return false;
 432}
 433
 434#ifdef CONFIG_MEMCG_KMEM
 435/*
 436 * slab_objcgs - get the object cgroups vector associated with a slab
 437 * @slab: a pointer to the slab struct
 438 *
 439 * Returns a pointer to the object cgroups vector associated with the slab,
 440 * or NULL if no such vector has been associated yet.
 441 */
 442static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
 443{
 444        unsigned long memcg_data = READ_ONCE(slab->memcg_data);
 445
 446        VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS),
 447                                                        slab_page(slab));
 448        VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
 449
 450        return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
 451}
 452
 453int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
 454                                 gfp_t gfp, bool new_slab);
 455void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 456                     enum node_stat_item idx, int nr);
 457
 458static inline void memcg_free_slab_cgroups(struct slab *slab)
 459{
 460        kfree(slab_objcgs(slab));
 461        slab->memcg_data = 0;
 462}
 463
 464static inline size_t obj_full_size(struct kmem_cache *s)
 465{
 466        /*
 467         * For each accounted object there is an extra space which is used
 468         * to store obj_cgroup membership. Charge it too.
 469         */
 470        return s->size + sizeof(struct obj_cgroup *);
 471}
 472
 473/*
 474 * Returns false if the allocation should fail.
 475 */
 476static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
 477                                             struct list_lru *lru,
 478                                             struct obj_cgroup **objcgp,
 479                                             size_t objects, gfp_t flags)
 480{
 481        struct obj_cgroup *objcg;
 482
 483        if (!memcg_kmem_enabled())
 484                return true;
 485
 486        if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
 487                return true;
 488
 489        objcg = get_obj_cgroup_from_current();
 490        if (!objcg)
 491                return true;
 492
 493        if (lru) {
 494                int ret;
 495                struct mem_cgroup *memcg;
 496
 497                memcg = get_mem_cgroup_from_objcg(objcg);
 498                ret = memcg_list_lru_alloc(memcg, lru, flags);
 499                css_put(&memcg->css);
 500
 501                if (ret)
 502                        goto out;
 503        }
 504
 505        if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
 506                goto out;
 507
 508        *objcgp = objcg;
 509        return true;
 510out:
 511        obj_cgroup_put(objcg);
 512        return false;
 513}
 514
 515static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 516                                              struct obj_cgroup *objcg,
 517                                              gfp_t flags, size_t size,
 518                                              void **p)
 519{
 520        struct slab *slab;
 521        unsigned long off;
 522        size_t i;
 523
 524        if (!memcg_kmem_enabled() || !objcg)
 525                return;
 526
 527        for (i = 0; i < size; i++) {
 528                if (likely(p[i])) {
 529                        slab = virt_to_slab(p[i]);
 530
 531                        if (!slab_objcgs(slab) &&
 532                            memcg_alloc_slab_cgroups(slab, s, flags,
 533                                                         false)) {
 534                                obj_cgroup_uncharge(objcg, obj_full_size(s));
 535                                continue;
 536                        }
 537
 538                        off = obj_to_index(s, slab, p[i]);
 539                        obj_cgroup_get(objcg);
 540                        slab_objcgs(slab)[off] = objcg;
 541                        mod_objcg_state(objcg, slab_pgdat(slab),
 542                                        cache_vmstat_idx(s), obj_full_size(s));
 543                } else {
 544                        obj_cgroup_uncharge(objcg, obj_full_size(s));
 545                }
 546        }
 547        obj_cgroup_put(objcg);
 548}
 549
 550static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
 551                                        void **p, int objects)
 552{
 553        struct kmem_cache *s;
 554        struct obj_cgroup **objcgs;
 555        struct obj_cgroup *objcg;
 556        struct slab *slab;
 557        unsigned int off;
 558        int i;
 559
 560        if (!memcg_kmem_enabled())
 561                return;
 562
 563        for (i = 0; i < objects; i++) {
 564                if (unlikely(!p[i]))
 565                        continue;
 566
 567                slab = virt_to_slab(p[i]);
 568                /* we could be given a kmalloc_large() object, skip those */
 569                if (!slab)
 570                        continue;
 571
 572                objcgs = slab_objcgs(slab);
 573                if (!objcgs)
 574                        continue;
 575
 576                if (!s_orig)
 577                        s = slab->slab_cache;
 578                else
 579                        s = s_orig;
 580
 581                off = obj_to_index(s, slab, p[i]);
 582                objcg = objcgs[off];
 583                if (!objcg)
 584                        continue;
 585
 586                objcgs[off] = NULL;
 587                obj_cgroup_uncharge(objcg, obj_full_size(s));
 588                mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
 589                                -obj_full_size(s));
 590                obj_cgroup_put(objcg);
 591        }
 592}
 593
 594#else /* CONFIG_MEMCG_KMEM */
 595static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
 596{
 597        return NULL;
 598}
 599
 600static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
 601{
 602        return NULL;
 603}
 604
 605static inline int memcg_alloc_slab_cgroups(struct slab *slab,
 606                                               struct kmem_cache *s, gfp_t gfp,
 607                                               bool new_slab)
 608{
 609        return 0;
 610}
 611
 612static inline void memcg_free_slab_cgroups(struct slab *slab)
 613{
 614}
 615
 616static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
 617                                             struct list_lru *lru,
 618                                             struct obj_cgroup **objcgp,
 619                                             size_t objects, gfp_t flags)
 620{
 621        return true;
 622}
 623
 624static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 625                                              struct obj_cgroup *objcg,
 626                                              gfp_t flags, size_t size,
 627                                              void **p)
 628{
 629}
 630
 631static inline void memcg_slab_free_hook(struct kmem_cache *s,
 632                                        void **p, int objects)
 633{
 634}
 635#endif /* CONFIG_MEMCG_KMEM */
 636
 637#ifndef CONFIG_SLOB
 638static inline struct kmem_cache *virt_to_cache(const void *obj)
 639{
 640        struct slab *slab;
 641
 642        slab = virt_to_slab(obj);
 643        if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
 644                                        __func__))
 645                return NULL;
 646        return slab->slab_cache;
 647}
 648
 649static __always_inline void account_slab(struct slab *slab, int order,
 650                                         struct kmem_cache *s, gfp_t gfp)
 651{
 652        if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT))
 653                memcg_alloc_slab_cgroups(slab, s, gfp, true);
 654
 655        mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
 656                            PAGE_SIZE << order);
 657}
 658
 659static __always_inline void unaccount_slab(struct slab *slab, int order,
 660                                           struct kmem_cache *s)
 661{
 662        if (memcg_kmem_enabled())
 663                memcg_free_slab_cgroups(slab);
 664
 665        mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
 666                            -(PAGE_SIZE << order));
 667}
 668
 669static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 670{
 671        struct kmem_cache *cachep;
 672
 673        if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
 674            !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
 675                return s;
 676
 677        cachep = virt_to_cache(x);
 678        if (WARN(cachep && cachep != s,
 679                  "%s: Wrong slab cache. %s but object is from %s\n",
 680                  __func__, s->name, cachep->name))
 681                print_tracking(cachep, x);
 682        return cachep;
 683}
 684#endif /* CONFIG_SLOB */
 685
 686static inline size_t slab_ksize(const struct kmem_cache *s)
 687{
 688#ifndef CONFIG_SLUB
 689        return s->object_size;
 690
 691#else /* CONFIG_SLUB */
 692# ifdef CONFIG_SLUB_DEBUG
 693        /*
 694         * Debugging requires use of the padding between object
 695         * and whatever may come after it.
 696         */
 697        if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
 698                return s->object_size;
 699# endif
 700        if (s->flags & SLAB_KASAN)
 701                return s->object_size;
 702        /*
 703         * If we have the need to store the freelist pointer
 704         * back there or track user information then we can
 705         * only use the space before that information.
 706         */
 707        if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
 708                return s->inuse;
 709        /*
 710         * Else we can use all the padding etc for the allocation
 711         */
 712        return s->size;
 713#endif
 714}
 715
 716static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 717                                                     struct list_lru *lru,
 718                                                     struct obj_cgroup **objcgp,
 719                                                     size_t size, gfp_t flags)
 720{
 721        flags &= gfp_allowed_mask;
 722
 723        might_alloc(flags);
 724
 725        if (should_failslab(s, flags))
 726                return NULL;
 727
 728        if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
 729                return NULL;
 730
 731        return s;
 732}
 733
 734static inline void slab_post_alloc_hook(struct kmem_cache *s,
 735                                        struct obj_cgroup *objcg, gfp_t flags,
 736                                        size_t size, void **p, bool init)
 737{
 738        size_t i;
 739
 740        flags &= gfp_allowed_mask;
 741
 742        /*
 743         * As memory initialization might be integrated into KASAN,
 744         * kasan_slab_alloc and initialization memset must be
 745         * kept together to avoid discrepancies in behavior.
 746         *
 747         * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
 748         */
 749        for (i = 0; i < size; i++) {
 750                p[i] = kasan_slab_alloc(s, p[i], flags, init);
 751                if (p[i] && init && !kasan_has_integrated_init())
 752                        memset(p[i], 0, s->object_size);
 753                kmemleak_alloc_recursive(p[i], s->object_size, 1,
 754                                         s->flags, flags);
 755        }
 756
 757        memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
 758}
 759
 760#ifndef CONFIG_SLOB
 761/*
 762 * The slab lists for all objects.
 763 */
 764struct kmem_cache_node {
 765        spinlock_t list_lock;
 766
 767#ifdef CONFIG_SLAB
 768        struct list_head slabs_partial; /* partial list first, better asm code */
 769        struct list_head slabs_full;
 770        struct list_head slabs_free;
 771        unsigned long total_slabs;      /* length of all slab lists */
 772        unsigned long free_slabs;       /* length of free slab list only */
 773        unsigned long free_objects;
 774        unsigned int free_limit;
 775        unsigned int colour_next;       /* Per-node cache coloring */
 776        struct array_cache *shared;     /* shared per node */
 777        struct alien_cache **alien;     /* on other nodes */
 778        unsigned long next_reap;        /* updated without locking */
 779        int free_touched;               /* updated without locking */
 780#endif
 781
 782#ifdef CONFIG_SLUB
 783        unsigned long nr_partial;
 784        struct list_head partial;
 785#ifdef CONFIG_SLUB_DEBUG
 786        atomic_long_t nr_slabs;
 787        atomic_long_t total_objects;
 788        struct list_head full;
 789#endif
 790#endif
 791
 792};
 793
 794static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
 795{
 796        return s->node[node];
 797}
 798
 799/*
 800 * Iterator over all nodes. The body will be executed for each node that has
 801 * a kmem_cache_node structure allocated (which is true for all online nodes)
 802 */
 803#define for_each_kmem_cache_node(__s, __node, __n) \
 804        for (__node = 0; __node < nr_node_ids; __node++) \
 805                 if ((__n = get_node(__s, __node)))
 806
 807#endif
 808
 809#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
 810void dump_unreclaimable_slab(void);
 811#else
 812static inline void dump_unreclaimable_slab(void)
 813{
 814}
 815#endif
 816
 817void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
 818
 819#ifdef CONFIG_SLAB_FREELIST_RANDOM
 820int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
 821                        gfp_t gfp);
 822void cache_random_seq_destroy(struct kmem_cache *cachep);
 823#else
 824static inline int cache_random_seq_create(struct kmem_cache *cachep,
 825                                        unsigned int count, gfp_t gfp)
 826{
 827        return 0;
 828}
 829static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
 830#endif /* CONFIG_SLAB_FREELIST_RANDOM */
 831
 832static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
 833{
 834        if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
 835                                &init_on_alloc)) {
 836                if (c->ctor)
 837                        return false;
 838                if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
 839                        return flags & __GFP_ZERO;
 840                return true;
 841        }
 842        return flags & __GFP_ZERO;
 843}
 844
 845static inline bool slab_want_init_on_free(struct kmem_cache *c)
 846{
 847        if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
 848                                &init_on_free))
 849                return !(c->ctor ||
 850                         (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
 851        return false;
 852}
 853
 854#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
 855void debugfs_slab_release(struct kmem_cache *);
 856#else
 857static inline void debugfs_slab_release(struct kmem_cache *s) { }
 858#endif
 859
 860#ifdef CONFIG_PRINTK
 861#define KS_ADDRS_COUNT 16
 862struct kmem_obj_info {
 863        void *kp_ptr;
 864        struct slab *kp_slab;
 865        void *kp_objp;
 866        unsigned long kp_data_offset;
 867        struct kmem_cache *kp_slab_cache;
 868        void *kp_ret;
 869        void *kp_stack[KS_ADDRS_COUNT];
 870        void *kp_free_stack[KS_ADDRS_COUNT];
 871};
 872void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
 873#endif
 874
 875#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
 876void __check_heap_object(const void *ptr, unsigned long n,
 877                         const struct slab *slab, bool to_user);
 878#else
 879static inline
 880void __check_heap_object(const void *ptr, unsigned long n,
 881                         const struct slab *slab, bool to_user)
 882{
 883}
 884#endif
 885
 886#endif /* MM_SLAB_H */
 887