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)
 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
 355bool __kmem_cache_empty(struct kmem_cache *);
 356int __kmem_cache_shutdown(struct kmem_cache *);
 357void __kmem_cache_release(struct kmem_cache *);
 358int __kmem_cache_shrink(struct kmem_cache *);
 359void slab_kmem_cache_release(struct kmem_cache *);
 360
 361struct seq_file;
 362struct file;
 363
 364struct slabinfo {
 365        unsigned long active_objs;
 366        unsigned long num_objs;
 367        unsigned long active_slabs;
 368        unsigned long num_slabs;
 369        unsigned long shared_avail;
 370        unsigned int limit;
 371        unsigned int batchcount;
 372        unsigned int shared;
 373        unsigned int objects_per_slab;
 374        unsigned int cache_order;
 375};
 376
 377void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
 378void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
 379ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 380                       size_t count, loff_t *ppos);
 381
 382/*
 383 * Generic implementation of bulk operations
 384 * These are useful for situations in which the allocator cannot
 385 * perform optimizations. In that case segments of the object listed
 386 * may be allocated or freed using these operations.
 387 */
 388void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
 389int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
 390
 391static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
 392{
 393        return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
 394                NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
 395}
 396
 397#ifdef CONFIG_SLUB_DEBUG
 398#ifdef CONFIG_SLUB_DEBUG_ON
 399DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
 400#else
 401DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
 402#endif
 403extern void print_tracking(struct kmem_cache *s, void *object);
 404long validate_slab_cache(struct kmem_cache *s);
 405static inline bool __slub_debug_enabled(void)
 406{
 407        return static_branch_unlikely(&slub_debug_enabled);
 408}
 409#else
 410static inline void print_tracking(struct kmem_cache *s, void *object)
 411{
 412}
 413static inline bool __slub_debug_enabled(void)
 414{
 415        return false;
 416}
 417#endif
 418
 419/*
 420 * Returns true if any of the specified slub_debug flags is enabled for the
 421 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
 422 * the static key.
 423 */
 424static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
 425{
 426        if (IS_ENABLED(CONFIG_SLUB_DEBUG))
 427                VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
 428        if (__slub_debug_enabled())
 429                return s->flags & flags;
 430        return false;
 431}
 432
 433#ifdef CONFIG_MEMCG_KMEM
 434/*
 435 * slab_objcgs - get the object cgroups vector associated with a slab
 436 * @slab: a pointer to the slab struct
 437 *
 438 * Returns a pointer to the object cgroups vector associated with the slab,
 439 * or NULL if no such vector has been associated yet.
 440 */
 441static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
 442{
 443        unsigned long memcg_data = READ_ONCE(slab->memcg_data);
 444
 445        VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS),
 446                                                        slab_page(slab));
 447        VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
 448
 449        return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
 450}
 451
 452int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
 453                                 gfp_t gfp, bool new_slab);
 454void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 455                     enum node_stat_item idx, int nr);
 456
 457static inline void memcg_free_slab_cgroups(struct slab *slab)
 458{
 459        kfree(slab_objcgs(slab));
 460        slab->memcg_data = 0;
 461}
 462
 463static inline size_t obj_full_size(struct kmem_cache *s)
 464{
 465        /*
 466         * For each accounted object there is an extra space which is used
 467         * to store obj_cgroup membership. Charge it too.
 468         */
 469        return s->size + sizeof(struct obj_cgroup *);
 470}
 471
 472/*
 473 * Returns false if the allocation should fail.
 474 */
 475static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
 476                                             struct list_lru *lru,
 477                                             struct obj_cgroup **objcgp,
 478                                             size_t objects, gfp_t flags)
 479{
 480        struct obj_cgroup *objcg;
 481
 482        if (!memcg_kmem_enabled())
 483                return true;
 484
 485        if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
 486                return true;
 487
 488        objcg = get_obj_cgroup_from_current();
 489        if (!objcg)
 490                return true;
 491
 492        if (lru) {
 493                int ret;
 494                struct mem_cgroup *memcg;
 495
 496                memcg = get_mem_cgroup_from_objcg(objcg);
 497                ret = memcg_list_lru_alloc(memcg, lru, flags);
 498                css_put(&memcg->css);
 499
 500                if (ret)
 501                        goto out;
 502        }
 503
 504        if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
 505                goto out;
 506
 507        *objcgp = objcg;
 508        return true;
 509out:
 510        obj_cgroup_put(objcg);
 511        return false;
 512}
 513
 514static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 515                                              struct obj_cgroup *objcg,
 516                                              gfp_t flags, size_t size,
 517                                              void **p)
 518{
 519        struct slab *slab;
 520        unsigned long off;
 521        size_t i;
 522
 523        if (!memcg_kmem_enabled() || !objcg)
 524                return;
 525
 526        for (i = 0; i < size; i++) {
 527                if (likely(p[i])) {
 528                        slab = virt_to_slab(p[i]);
 529
 530                        if (!slab_objcgs(slab) &&
 531                            memcg_alloc_slab_cgroups(slab, s, flags,
 532                                                         false)) {
 533                                obj_cgroup_uncharge(objcg, obj_full_size(s));
 534                                continue;
 535                        }
 536
 537                        off = obj_to_index(s, slab, p[i]);
 538                        obj_cgroup_get(objcg);
 539                        slab_objcgs(slab)[off] = objcg;
 540                        mod_objcg_state(objcg, slab_pgdat(slab),
 541                                        cache_vmstat_idx(s), obj_full_size(s));
 542                } else {
 543                        obj_cgroup_uncharge(objcg, obj_full_size(s));
 544                }
 545        }
 546        obj_cgroup_put(objcg);
 547}
 548
 549static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
 550                                        void **p, int objects)
 551{
 552        struct kmem_cache *s;
 553        struct obj_cgroup **objcgs;
 554        struct obj_cgroup *objcg;
 555        struct slab *slab;
 556        unsigned int off;
 557        int i;
 558
 559        if (!memcg_kmem_enabled())
 560                return;
 561
 562        for (i = 0; i < objects; i++) {
 563                if (unlikely(!p[i]))
 564                        continue;
 565
 566                slab = virt_to_slab(p[i]);
 567                /* we could be given a kmalloc_large() object, skip those */
 568                if (!slab)
 569                        continue;
 570
 571                objcgs = slab_objcgs(slab);
 572                if (!objcgs)
 573                        continue;
 574
 575                if (!s_orig)
 576                        s = slab->slab_cache;
 577                else
 578                        s = s_orig;
 579
 580                off = obj_to_index(s, slab, p[i]);
 581                objcg = objcgs[off];
 582                if (!objcg)
 583                        continue;
 584
 585                objcgs[off] = NULL;
 586                obj_cgroup_uncharge(objcg, obj_full_size(s));
 587                mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
 588                                -obj_full_size(s));
 589                obj_cgroup_put(objcg);
 590        }
 591}
 592
 593#else /* CONFIG_MEMCG_KMEM */
 594static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
 595{
 596        return NULL;
 597}
 598
 599static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
 600{
 601        return NULL;
 602}
 603
 604static inline int memcg_alloc_slab_cgroups(struct slab *slab,
 605                                               struct kmem_cache *s, gfp_t gfp,
 606                                               bool new_slab)
 607{
 608        return 0;
 609}
 610
 611static inline void memcg_free_slab_cgroups(struct slab *slab)
 612{
 613}
 614
 615static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
 616                                             struct list_lru *lru,
 617                                             struct obj_cgroup **objcgp,
 618                                             size_t objects, gfp_t flags)
 619{
 620        return true;
 621}
 622
 623static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 624                                              struct obj_cgroup *objcg,
 625                                              gfp_t flags, size_t size,
 626                                              void **p)
 627{
 628}
 629
 630static inline void memcg_slab_free_hook(struct kmem_cache *s,
 631                                        void **p, int objects)
 632{
 633}
 634#endif /* CONFIG_MEMCG_KMEM */
 635
 636#ifndef CONFIG_SLOB
 637static inline struct kmem_cache *virt_to_cache(const void *obj)
 638{
 639        struct slab *slab;
 640
 641        slab = virt_to_slab(obj);
 642        if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
 643                                        __func__))
 644                return NULL;
 645        return slab->slab_cache;
 646}
 647
 648static __always_inline void account_slab(struct slab *slab, int order,
 649                                         struct kmem_cache *s, gfp_t gfp)
 650{
 651        if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT))
 652                memcg_alloc_slab_cgroups(slab, s, gfp, true);
 653
 654        mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
 655                            PAGE_SIZE << order);
 656}
 657
 658static __always_inline void unaccount_slab(struct slab *slab, int order,
 659                                           struct kmem_cache *s)
 660{
 661        if (memcg_kmem_enabled())
 662                memcg_free_slab_cgroups(slab);
 663
 664        mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
 665                            -(PAGE_SIZE << order));
 666}
 667
 668static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 669{
 670        struct kmem_cache *cachep;
 671
 672        if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
 673            !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
 674                return s;
 675
 676        cachep = virt_to_cache(x);
 677        if (WARN(cachep && cachep != s,
 678                  "%s: Wrong slab cache. %s but object is from %s\n",
 679                  __func__, s->name, cachep->name))
 680                print_tracking(cachep, x);
 681        return cachep;
 682}
 683#endif /* CONFIG_SLOB */
 684
 685static inline size_t slab_ksize(const struct kmem_cache *s)
 686{
 687#ifndef CONFIG_SLUB
 688        return s->object_size;
 689
 690#else /* CONFIG_SLUB */
 691# ifdef CONFIG_SLUB_DEBUG
 692        /*
 693         * Debugging requires use of the padding between object
 694         * and whatever may come after it.
 695         */
 696        if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
 697                return s->object_size;
 698# endif
 699        if (s->flags & SLAB_KASAN)
 700                return s->object_size;
 701        /*
 702         * If we have the need to store the freelist pointer
 703         * back there or track user information then we can
 704         * only use the space before that information.
 705         */
 706        if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
 707                return s->inuse;
 708        /*
 709         * Else we can use all the padding etc for the allocation
 710         */
 711        return s->size;
 712#endif
 713}
 714
 715static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 716                                                     struct list_lru *lru,
 717                                                     struct obj_cgroup **objcgp,
 718                                                     size_t size, gfp_t flags)
 719{
 720        flags &= gfp_allowed_mask;
 721
 722        might_alloc(flags);
 723
 724        if (should_failslab(s, flags))
 725                return NULL;
 726
 727        if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
 728                return NULL;
 729
 730        return s;
 731}
 732
 733static inline void slab_post_alloc_hook(struct kmem_cache *s,
 734                                        struct obj_cgroup *objcg, gfp_t flags,
 735                                        size_t size, void **p, bool init)
 736{
 737        size_t i;
 738
 739        flags &= gfp_allowed_mask;
 740
 741        /*
 742         * As memory initialization might be integrated into KASAN,
 743         * kasan_slab_alloc and initialization memset must be
 744         * kept together to avoid discrepancies in behavior.
 745         *
 746         * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
 747         */
 748        for (i = 0; i < size; i++) {
 749                p[i] = kasan_slab_alloc(s, p[i], flags, init);
 750                if (p[i] && init && !kasan_has_integrated_init())
 751                        memset(p[i], 0, s->object_size);
 752                kmemleak_alloc_recursive(p[i], s->object_size, 1,
 753                                         s->flags, flags);
 754        }
 755
 756        memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
 757}
 758
 759#ifndef CONFIG_SLOB
 760/*
 761 * The slab lists for all objects.
 762 */
 763struct kmem_cache_node {
 764        spinlock_t list_lock;
 765
 766#ifdef CONFIG_SLAB
 767        struct list_head slabs_partial; /* partial list first, better asm code */
 768        struct list_head slabs_full;
 769        struct list_head slabs_free;
 770        unsigned long total_slabs;      /* length of all slab lists */
 771        unsigned long free_slabs;       /* length of free slab list only */
 772        unsigned long free_objects;
 773        unsigned int free_limit;
 774        unsigned int colour_next;       /* Per-node cache coloring */
 775        struct array_cache *shared;     /* shared per node */
 776        struct alien_cache **alien;     /* on other nodes */
 777        unsigned long next_reap;        /* updated without locking */
 778        int free_touched;               /* updated without locking */
 779#endif
 780
 781#ifdef CONFIG_SLUB
 782        unsigned long nr_partial;
 783        struct list_head partial;
 784#ifdef CONFIG_SLUB_DEBUG
 785        atomic_long_t nr_slabs;
 786        atomic_long_t total_objects;
 787        struct list_head full;
 788#endif
 789#endif
 790
 791};
 792
 793static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
 794{
 795        return s->node[node];
 796}
 797
 798/*
 799 * Iterator over all nodes. The body will be executed for each node that has
 800 * a kmem_cache_node structure allocated (which is true for all online nodes)
 801 */
 802#define for_each_kmem_cache_node(__s, __node, __n) \
 803        for (__node = 0; __node < nr_node_ids; __node++) \
 804                 if ((__n = get_node(__s, __node)))
 805
 806#endif
 807
 808#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
 809void dump_unreclaimable_slab(void);
 810#else
 811static inline void dump_unreclaimable_slab(void)
 812{
 813}
 814#endif
 815
 816void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
 817
 818#ifdef CONFIG_SLAB_FREELIST_RANDOM
 819int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
 820                        gfp_t gfp);
 821void cache_random_seq_destroy(struct kmem_cache *cachep);
 822#else
 823static inline int cache_random_seq_create(struct kmem_cache *cachep,
 824                                        unsigned int count, gfp_t gfp)
 825{
 826        return 0;
 827}
 828static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
 829#endif /* CONFIG_SLAB_FREELIST_RANDOM */
 830
 831static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
 832{
 833        if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
 834                                &init_on_alloc)) {
 835                if (c->ctor)
 836                        return false;
 837                if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
 838                        return flags & __GFP_ZERO;
 839                return true;
 840        }
 841        return flags & __GFP_ZERO;
 842}
 843
 844static inline bool slab_want_init_on_free(struct kmem_cache *c)
 845{
 846        if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
 847                                &init_on_free))
 848                return !(c->ctor ||
 849                         (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
 850        return false;
 851}
 852
 853#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
 854void debugfs_slab_release(struct kmem_cache *);
 855#else
 856static inline void debugfs_slab_release(struct kmem_cache *s) { }
 857#endif
 858
 859#ifdef CONFIG_PRINTK
 860#define KS_ADDRS_COUNT 16
 861struct kmem_obj_info {
 862        void *kp_ptr;
 863        struct slab *kp_slab;
 864        void *kp_objp;
 865        unsigned long kp_data_offset;
 866        struct kmem_cache *kp_slab_cache;
 867        void *kp_ret;
 868        void *kp_stack[KS_ADDRS_COUNT];
 869        void *kp_free_stack[KS_ADDRS_COUNT];
 870};
 871void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
 872#endif
 873
 874#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
 875void __check_heap_object(const void *ptr, unsigned long n,
 876                         const struct slab *slab, bool to_user);
 877#else
 878static inline
 879void __check_heap_object(const void *ptr, unsigned long n,
 880                         const struct slab *slab, bool to_user)
 881{
 882}
 883#endif
 884
 885#endif /* MM_SLAB_H */
 886