linux/include/linux/slab.h
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   1/*
   2 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
   3 *
   4 * (C) SGI 2006, Christoph Lameter
   5 *      Cleaned up and restructured to ease the addition of alternative
   6 *      implementations of SLAB allocators.
   7 * (C) Linux Foundation 2008-2013
   8 *      Unified interface for all slab allocators
   9 */
  10
  11#ifndef _LINUX_SLAB_H
  12#define _LINUX_SLAB_H
  13
  14#include <linux/gfp.h>
  15#include <linux/types.h>
  16#include <linux/workqueue.h>
  17
  18
  19/*
  20 * Flags to pass to kmem_cache_create().
  21 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
  22 */
  23#define SLAB_CONSISTENCY_CHECKS 0x00000100UL    /* DEBUG: Perform (expensive) checks on alloc/free */
  24#define SLAB_RED_ZONE           0x00000400UL    /* DEBUG: Red zone objs in a cache */
  25#define SLAB_POISON             0x00000800UL    /* DEBUG: Poison objects */
  26#define SLAB_HWCACHE_ALIGN      0x00002000UL    /* Align objs on cache lines */
  27#define SLAB_CACHE_DMA          0x00004000UL    /* Use GFP_DMA memory */
  28#define SLAB_STORE_USER         0x00010000UL    /* DEBUG: Store the last owner for bug hunting */
  29#define SLAB_PANIC              0x00040000UL    /* Panic if kmem_cache_create() fails */
  30/*
  31 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
  32 *
  33 * This delays freeing the SLAB page by a grace period, it does _NOT_
  34 * delay object freeing. This means that if you do kmem_cache_free()
  35 * that memory location is free to be reused at any time. Thus it may
  36 * be possible to see another object there in the same RCU grace period.
  37 *
  38 * This feature only ensures the memory location backing the object
  39 * stays valid, the trick to using this is relying on an independent
  40 * object validation pass. Something like:
  41 *
  42 *  rcu_read_lock()
  43 * again:
  44 *  obj = lockless_lookup(key);
  45 *  if (obj) {
  46 *    if (!try_get_ref(obj)) // might fail for free objects
  47 *      goto again;
  48 *
  49 *    if (obj->key != key) { // not the object we expected
  50 *      put_ref(obj);
  51 *      goto again;
  52 *    }
  53 *  }
  54 *  rcu_read_unlock();
  55 *
  56 * This is useful if we need to approach a kernel structure obliquely,
  57 * from its address obtained without the usual locking. We can lock
  58 * the structure to stabilize it and check it's still at the given address,
  59 * only if we can be sure that the memory has not been meanwhile reused
  60 * for some other kind of object (which our subsystem's lock might corrupt).
  61 *
  62 * rcu_read_lock before reading the address, then rcu_read_unlock after
  63 * taking the spinlock within the structure expected at that address.
  64 *
  65 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
  66 */
  67#define SLAB_TYPESAFE_BY_RCU    0x00080000UL    /* Defer freeing slabs to RCU */
  68#define SLAB_MEM_SPREAD         0x00100000UL    /* Spread some memory over cpuset */
  69#define SLAB_TRACE              0x00200000UL    /* Trace allocations and frees */
  70
  71/* Flag to prevent checks on free */
  72#ifdef CONFIG_DEBUG_OBJECTS
  73# define SLAB_DEBUG_OBJECTS     0x00400000UL
  74#else
  75# define SLAB_DEBUG_OBJECTS     0x00000000UL
  76#endif
  77
  78#define SLAB_NOLEAKTRACE        0x00800000UL    /* Avoid kmemleak tracing */
  79
  80/* Don't track use of uninitialized memory */
  81#ifdef CONFIG_KMEMCHECK
  82# define SLAB_NOTRACK           0x01000000UL
  83#else
  84# define SLAB_NOTRACK           0x00000000UL
  85#endif
  86#ifdef CONFIG_FAILSLAB
  87# define SLAB_FAILSLAB          0x02000000UL    /* Fault injection mark */
  88#else
  89# define SLAB_FAILSLAB          0x00000000UL
  90#endif
  91#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
  92# define SLAB_ACCOUNT           0x04000000UL    /* Account to memcg */
  93#else
  94# define SLAB_ACCOUNT           0x00000000UL
  95#endif
  96
  97#ifdef CONFIG_KASAN
  98#define SLAB_KASAN              0x08000000UL
  99#else
 100#define SLAB_KASAN              0x00000000UL
 101#endif
 102
 103/* The following flags affect the page allocator grouping pages by mobility */
 104#define SLAB_RECLAIM_ACCOUNT    0x00020000UL            /* Objects are reclaimable */
 105#define SLAB_TEMPORARY          SLAB_RECLAIM_ACCOUNT    /* Objects are short-lived */
 106/*
 107 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
 108 *
 109 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
 110 *
 111 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
 112 * Both make kfree a no-op.
 113 */
 114#define ZERO_SIZE_PTR ((void *)16)
 115
 116#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
 117                                (unsigned long)ZERO_SIZE_PTR)
 118
 119#include <linux/kmemleak.h>
 120#include <linux/kasan.h>
 121
 122struct mem_cgroup;
 123/*
 124 * struct kmem_cache related prototypes
 125 */
 126void __init kmem_cache_init(void);
 127bool slab_is_available(void);
 128
 129struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
 130                        unsigned long,
 131                        void (*)(void *));
 132void kmem_cache_destroy(struct kmem_cache *);
 133int kmem_cache_shrink(struct kmem_cache *);
 134
 135void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
 136void memcg_deactivate_kmem_caches(struct mem_cgroup *);
 137void memcg_destroy_kmem_caches(struct mem_cgroup *);
 138
 139/*
 140 * Please use this macro to create slab caches. Simply specify the
 141 * name of the structure and maybe some flags that are listed above.
 142 *
 143 * The alignment of the struct determines object alignment. If you
 144 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
 145 * then the objects will be properly aligned in SMP configurations.
 146 */
 147#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
 148                sizeof(struct __struct), __alignof__(struct __struct),\
 149                (__flags), NULL)
 150
 151/*
 152 * Common kmalloc functions provided by all allocators
 153 */
 154void * __must_check __krealloc(const void *, size_t, gfp_t);
 155void * __must_check krealloc(const void *, size_t, gfp_t);
 156void kfree(const void *);
 157void kzfree(const void *);
 158size_t ksize(const void *);
 159
 160#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
 161const char *__check_heap_object(const void *ptr, unsigned long n,
 162                                struct page *page);
 163#else
 164static inline const char *__check_heap_object(const void *ptr,
 165                                              unsigned long n,
 166                                              struct page *page)
 167{
 168        return NULL;
 169}
 170#endif
 171
 172/*
 173 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
 174 * alignment larger than the alignment of a 64-bit integer.
 175 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
 176 */
 177#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
 178#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
 179#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
 180#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
 181#else
 182#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
 183#endif
 184
 185/*
 186 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
 187 * Intended for arches that get misalignment faults even for 64 bit integer
 188 * aligned buffers.
 189 */
 190#ifndef ARCH_SLAB_MINALIGN
 191#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
 192#endif
 193
 194/*
 195 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
 196 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
 197 * aligned pointers.
 198 */
 199#define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
 200#define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
 201#define __assume_page_alignment __assume_aligned(PAGE_SIZE)
 202
 203/*
 204 * Kmalloc array related definitions
 205 */
 206
 207#ifdef CONFIG_SLAB
 208/*
 209 * The largest kmalloc size supported by the SLAB allocators is
 210 * 32 megabyte (2^25) or the maximum allocatable page order if that is
 211 * less than 32 MB.
 212 *
 213 * WARNING: Its not easy to increase this value since the allocators have
 214 * to do various tricks to work around compiler limitations in order to
 215 * ensure proper constant folding.
 216 */
 217#define KMALLOC_SHIFT_HIGH      ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
 218                                (MAX_ORDER + PAGE_SHIFT - 1) : 25)
 219#define KMALLOC_SHIFT_MAX       KMALLOC_SHIFT_HIGH
 220#ifndef KMALLOC_SHIFT_LOW
 221#define KMALLOC_SHIFT_LOW       5
 222#endif
 223#endif
 224
 225#ifdef CONFIG_SLUB
 226/*
 227 * SLUB directly allocates requests fitting in to an order-1 page
 228 * (PAGE_SIZE*2).  Larger requests are passed to the page allocator.
 229 */
 230#define KMALLOC_SHIFT_HIGH      (PAGE_SHIFT + 1)
 231#define KMALLOC_SHIFT_MAX       (MAX_ORDER + PAGE_SHIFT - 1)
 232#ifndef KMALLOC_SHIFT_LOW
 233#define KMALLOC_SHIFT_LOW       3
 234#endif
 235#endif
 236
 237#ifdef CONFIG_SLOB
 238/*
 239 * SLOB passes all requests larger than one page to the page allocator.
 240 * No kmalloc array is necessary since objects of different sizes can
 241 * be allocated from the same page.
 242 */
 243#define KMALLOC_SHIFT_HIGH      PAGE_SHIFT
 244#define KMALLOC_SHIFT_MAX       (MAX_ORDER + PAGE_SHIFT - 1)
 245#ifndef KMALLOC_SHIFT_LOW
 246#define KMALLOC_SHIFT_LOW       3
 247#endif
 248#endif
 249
 250/* Maximum allocatable size */
 251#define KMALLOC_MAX_SIZE        (1UL << KMALLOC_SHIFT_MAX)
 252/* Maximum size for which we actually use a slab cache */
 253#define KMALLOC_MAX_CACHE_SIZE  (1UL << KMALLOC_SHIFT_HIGH)
 254/* Maximum order allocatable via the slab allocagtor */
 255#define KMALLOC_MAX_ORDER       (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
 256
 257/*
 258 * Kmalloc subsystem.
 259 */
 260#ifndef KMALLOC_MIN_SIZE
 261#define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
 262#endif
 263
 264/*
 265 * This restriction comes from byte sized index implementation.
 266 * Page size is normally 2^12 bytes and, in this case, if we want to use
 267 * byte sized index which can represent 2^8 entries, the size of the object
 268 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
 269 * If minimum size of kmalloc is less than 16, we use it as minimum object
 270 * size and give up to use byte sized index.
 271 */
 272#define SLAB_OBJ_MIN_SIZE      (KMALLOC_MIN_SIZE < 16 ? \
 273                               (KMALLOC_MIN_SIZE) : 16)
 274
 275#ifndef CONFIG_SLOB
 276extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
 277#ifdef CONFIG_ZONE_DMA
 278extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
 279#endif
 280
 281/*
 282 * Figure out which kmalloc slab an allocation of a certain size
 283 * belongs to.
 284 * 0 = zero alloc
 285 * 1 =  65 .. 96 bytes
 286 * 2 = 129 .. 192 bytes
 287 * n = 2^(n-1)+1 .. 2^n
 288 */
 289static __always_inline int kmalloc_index(size_t size)
 290{
 291        if (!size)
 292                return 0;
 293
 294        if (size <= KMALLOC_MIN_SIZE)
 295                return KMALLOC_SHIFT_LOW;
 296
 297        if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
 298                return 1;
 299        if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
 300                return 2;
 301        if (size <=          8) return 3;
 302        if (size <=         16) return 4;
 303        if (size <=         32) return 5;
 304        if (size <=         64) return 6;
 305        if (size <=        128) return 7;
 306        if (size <=        256) return 8;
 307        if (size <=        512) return 9;
 308        if (size <=       1024) return 10;
 309        if (size <=   2 * 1024) return 11;
 310        if (size <=   4 * 1024) return 12;
 311        if (size <=   8 * 1024) return 13;
 312        if (size <=  16 * 1024) return 14;
 313        if (size <=  32 * 1024) return 15;
 314        if (size <=  64 * 1024) return 16;
 315        if (size <= 128 * 1024) return 17;
 316        if (size <= 256 * 1024) return 18;
 317        if (size <= 512 * 1024) return 19;
 318        if (size <= 1024 * 1024) return 20;
 319        if (size <=  2 * 1024 * 1024) return 21;
 320        if (size <=  4 * 1024 * 1024) return 22;
 321        if (size <=  8 * 1024 * 1024) return 23;
 322        if (size <=  16 * 1024 * 1024) return 24;
 323        if (size <=  32 * 1024 * 1024) return 25;
 324        if (size <=  64 * 1024 * 1024) return 26;
 325        BUG();
 326
 327        /* Will never be reached. Needed because the compiler may complain */
 328        return -1;
 329}
 330#endif /* !CONFIG_SLOB */
 331
 332void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
 333void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
 334void kmem_cache_free(struct kmem_cache *, void *);
 335
 336/*
 337 * Bulk allocation and freeing operations. These are accelerated in an
 338 * allocator specific way to avoid taking locks repeatedly or building
 339 * metadata structures unnecessarily.
 340 *
 341 * Note that interrupts must be enabled when calling these functions.
 342 */
 343void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
 344int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
 345
 346/*
 347 * Caller must not use kfree_bulk() on memory not originally allocated
 348 * by kmalloc(), because the SLOB allocator cannot handle this.
 349 */
 350static __always_inline void kfree_bulk(size_t size, void **p)
 351{
 352        kmem_cache_free_bulk(NULL, size, p);
 353}
 354
 355#ifdef CONFIG_NUMA
 356void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
 357void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;
 358#else
 359static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
 360{
 361        return __kmalloc(size, flags);
 362}
 363
 364static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
 365{
 366        return kmem_cache_alloc(s, flags);
 367}
 368#endif
 369
 370#ifdef CONFIG_TRACING
 371extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc;
 372
 373#ifdef CONFIG_NUMA
 374extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
 375                                           gfp_t gfpflags,
 376                                           int node, size_t size) __assume_slab_alignment __malloc;
 377#else
 378static __always_inline void *
 379kmem_cache_alloc_node_trace(struct kmem_cache *s,
 380                              gfp_t gfpflags,
 381                              int node, size_t size)
 382{
 383        return kmem_cache_alloc_trace(s, gfpflags, size);
 384}
 385#endif /* CONFIG_NUMA */
 386
 387#else /* CONFIG_TRACING */
 388static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
 389                gfp_t flags, size_t size)
 390{
 391        void *ret = kmem_cache_alloc(s, flags);
 392
 393        kasan_kmalloc(s, ret, size, flags);
 394        return ret;
 395}
 396
 397static __always_inline void *
 398kmem_cache_alloc_node_trace(struct kmem_cache *s,
 399                              gfp_t gfpflags,
 400                              int node, size_t size)
 401{
 402        void *ret = kmem_cache_alloc_node(s, gfpflags, node);
 403
 404        kasan_kmalloc(s, ret, size, gfpflags);
 405        return ret;
 406}
 407#endif /* CONFIG_TRACING */
 408
 409extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
 410
 411#ifdef CONFIG_TRACING
 412extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
 413#else
 414static __always_inline void *
 415kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
 416{
 417        return kmalloc_order(size, flags, order);
 418}
 419#endif
 420
 421static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
 422{
 423        unsigned int order = get_order(size);
 424        return kmalloc_order_trace(size, flags, order);
 425}
 426
 427/**
 428 * kmalloc - allocate memory
 429 * @size: how many bytes of memory are required.
 430 * @flags: the type of memory to allocate.
 431 *
 432 * kmalloc is the normal method of allocating memory
 433 * for objects smaller than page size in the kernel.
 434 *
 435 * The @flags argument may be one of:
 436 *
 437 * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 438 *
 439 * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 440 *
 441 * %GFP_ATOMIC - Allocation will not sleep.  May use emergency pools.
 442 *   For example, use this inside interrupt handlers.
 443 *
 444 * %GFP_HIGHUSER - Allocate pages from high memory.
 445 *
 446 * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
 447 *
 448 * %GFP_NOFS - Do not make any fs calls while trying to get memory.
 449 *
 450 * %GFP_NOWAIT - Allocation will not sleep.
 451 *
 452 * %__GFP_THISNODE - Allocate node-local memory only.
 453 *
 454 * %GFP_DMA - Allocation suitable for DMA.
 455 *   Should only be used for kmalloc() caches. Otherwise, use a
 456 *   slab created with SLAB_DMA.
 457 *
 458 * Also it is possible to set different flags by OR'ing
 459 * in one or more of the following additional @flags:
 460 *
 461 * %__GFP_COLD - Request cache-cold pages instead of
 462 *   trying to return cache-warm pages.
 463 *
 464 * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
 465 *
 466 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
 467 *   (think twice before using).
 468 *
 469 * %__GFP_NORETRY - If memory is not immediately available,
 470 *   then give up at once.
 471 *
 472 * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
 473 *
 474 * %__GFP_RETRY_MAYFAIL - Try really hard to succeed the allocation but fail
 475 *   eventually.
 476 *
 477 * There are other flags available as well, but these are not intended
 478 * for general use, and so are not documented here. For a full list of
 479 * potential flags, always refer to linux/gfp.h.
 480 */
 481static __always_inline void *kmalloc(size_t size, gfp_t flags)
 482{
 483        if (__builtin_constant_p(size)) {
 484                if (size > KMALLOC_MAX_CACHE_SIZE)
 485                        return kmalloc_large(size, flags);
 486#ifndef CONFIG_SLOB
 487                if (!(flags & GFP_DMA)) {
 488                        int index = kmalloc_index(size);
 489
 490                        if (!index)
 491                                return ZERO_SIZE_PTR;
 492
 493                        return kmem_cache_alloc_trace(kmalloc_caches[index],
 494                                        flags, size);
 495                }
 496#endif
 497        }
 498        return __kmalloc(size, flags);
 499}
 500
 501/*
 502 * Determine size used for the nth kmalloc cache.
 503 * return size or 0 if a kmalloc cache for that
 504 * size does not exist
 505 */
 506static __always_inline int kmalloc_size(int n)
 507{
 508#ifndef CONFIG_SLOB
 509        if (n > 2)
 510                return 1 << n;
 511
 512        if (n == 1 && KMALLOC_MIN_SIZE <= 32)
 513                return 96;
 514
 515        if (n == 2 && KMALLOC_MIN_SIZE <= 64)
 516                return 192;
 517#endif
 518        return 0;
 519}
 520
 521static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 522{
 523#ifndef CONFIG_SLOB
 524        if (__builtin_constant_p(size) &&
 525                size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
 526                int i = kmalloc_index(size);
 527
 528                if (!i)
 529                        return ZERO_SIZE_PTR;
 530
 531                return kmem_cache_alloc_node_trace(kmalloc_caches[i],
 532                                                flags, node, size);
 533        }
 534#endif
 535        return __kmalloc_node(size, flags, node);
 536}
 537
 538struct memcg_cache_array {
 539        struct rcu_head rcu;
 540        struct kmem_cache *entries[0];
 541};
 542
 543/*
 544 * This is the main placeholder for memcg-related information in kmem caches.
 545 * Both the root cache and the child caches will have it. For the root cache,
 546 * this will hold a dynamically allocated array large enough to hold
 547 * information about the currently limited memcgs in the system. To allow the
 548 * array to be accessed without taking any locks, on relocation we free the old
 549 * version only after a grace period.
 550 *
 551 * Root and child caches hold different metadata.
 552 *
 553 * @root_cache: Common to root and child caches.  NULL for root, pointer to
 554 *              the root cache for children.
 555 *
 556 * The following fields are specific to root caches.
 557 *
 558 * @memcg_caches: kmemcg ID indexed table of child caches.  This table is
 559 *              used to index child cachces during allocation and cleared
 560 *              early during shutdown.
 561 *
 562 * @root_caches_node: List node for slab_root_caches list.
 563 *
 564 * @children:   List of all child caches.  While the child caches are also
 565 *              reachable through @memcg_caches, a child cache remains on
 566 *              this list until it is actually destroyed.
 567 *
 568 * The following fields are specific to child caches.
 569 *
 570 * @memcg:      Pointer to the memcg this cache belongs to.
 571 *
 572 * @children_node: List node for @root_cache->children list.
 573 *
 574 * @kmem_caches_node: List node for @memcg->kmem_caches list.
 575 */
 576struct memcg_cache_params {
 577        struct kmem_cache *root_cache;
 578        union {
 579                struct {
 580                        struct memcg_cache_array __rcu *memcg_caches;
 581                        struct list_head __root_caches_node;
 582                        struct list_head children;
 583                };
 584                struct {
 585                        struct mem_cgroup *memcg;
 586                        struct list_head children_node;
 587                        struct list_head kmem_caches_node;
 588
 589                        void (*deact_fn)(struct kmem_cache *);
 590                        union {
 591                                struct rcu_head deact_rcu_head;
 592                                struct work_struct deact_work;
 593                        };
 594                };
 595        };
 596};
 597
 598int memcg_update_all_caches(int num_memcgs);
 599
 600/**
 601 * kmalloc_array - allocate memory for an array.
 602 * @n: number of elements.
 603 * @size: element size.
 604 * @flags: the type of memory to allocate (see kmalloc).
 605 */
 606static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
 607{
 608        if (size != 0 && n > SIZE_MAX / size)
 609                return NULL;
 610        if (__builtin_constant_p(n) && __builtin_constant_p(size))
 611                return kmalloc(n * size, flags);
 612        return __kmalloc(n * size, flags);
 613}
 614
 615/**
 616 * kcalloc - allocate memory for an array. The memory is set to zero.
 617 * @n: number of elements.
 618 * @size: element size.
 619 * @flags: the type of memory to allocate (see kmalloc).
 620 */
 621static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
 622{
 623        return kmalloc_array(n, size, flags | __GFP_ZERO);
 624}
 625
 626/*
 627 * kmalloc_track_caller is a special version of kmalloc that records the
 628 * calling function of the routine calling it for slab leak tracking instead
 629 * of just the calling function (confusing, eh?).
 630 * It's useful when the call to kmalloc comes from a widely-used standard
 631 * allocator where we care about the real place the memory allocation
 632 * request comes from.
 633 */
 634extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
 635#define kmalloc_track_caller(size, flags) \
 636        __kmalloc_track_caller(size, flags, _RET_IP_)
 637
 638#ifdef CONFIG_NUMA
 639extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
 640#define kmalloc_node_track_caller(size, flags, node) \
 641        __kmalloc_node_track_caller(size, flags, node, \
 642                        _RET_IP_)
 643
 644#else /* CONFIG_NUMA */
 645
 646#define kmalloc_node_track_caller(size, flags, node) \
 647        kmalloc_track_caller(size, flags)
 648
 649#endif /* CONFIG_NUMA */
 650
 651/*
 652 * Shortcuts
 653 */
 654static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
 655{
 656        return kmem_cache_alloc(k, flags | __GFP_ZERO);
 657}
 658
 659/**
 660 * kzalloc - allocate memory. The memory is set to zero.
 661 * @size: how many bytes of memory are required.
 662 * @flags: the type of memory to allocate (see kmalloc).
 663 */
 664static inline void *kzalloc(size_t size, gfp_t flags)
 665{
 666        return kmalloc(size, flags | __GFP_ZERO);
 667}
 668
 669/**
 670 * kzalloc_node - allocate zeroed memory from a particular memory node.
 671 * @size: how many bytes of memory are required.
 672 * @flags: the type of memory to allocate (see kmalloc).
 673 * @node: memory node from which to allocate
 674 */
 675static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
 676{
 677        return kmalloc_node(size, flags | __GFP_ZERO, node);
 678}
 679
 680unsigned int kmem_cache_size(struct kmem_cache *s);
 681void __init kmem_cache_init_late(void);
 682
 683#if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
 684int slab_prepare_cpu(unsigned int cpu);
 685int slab_dead_cpu(unsigned int cpu);
 686#else
 687#define slab_prepare_cpu        NULL
 688#define slab_dead_cpu           NULL
 689#endif
 690
 691#endif  /* _LINUX_SLAB_H */
 692