1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). 4 * 5 * (C) SGI 2006, Christoph Lameter 6 * Cleaned up and restructured to ease the addition of alternative 7 * implementations of SLAB allocators. 8 * (C) Linux Foundation 2008-2013 9 * Unified interface for all slab allocators 10 */ 11 12 #ifndef _LINUX_SLAB_H 13 #define _LINUX_SLAB_H 14 15 #include <linux/gfp.h> 16 #include <linux/overflow.h> 17 #include <linux/types.h> 18 #include <linux/workqueue.h> 19 20 21 /* 22 * Flags to pass to kmem_cache_create(). 23 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set. 24 */ 25 /* DEBUG: Perform (expensive) checks on alloc/free */ 26 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U) 27 /* DEBUG: Red zone objs in a cache */ 28 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U) 29 /* DEBUG: Poison objects */ 30 #define SLAB_POISON ((slab_flags_t __force)0x00000800U) 31 /* Align objs on cache lines */ 32 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U) 33 /* Use GFP_DMA memory */ 34 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U) 35 /* DEBUG: Store the last owner for bug hunting */ 36 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U) 37 /* Panic if kmem_cache_create() fails */ 38 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U) 39 /* 40 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS! 41 * 42 * This delays freeing the SLAB page by a grace period, it does _NOT_ 43 * delay object freeing. This means that if you do kmem_cache_free() 44 * that memory location is free to be reused at any time. Thus it may 45 * be possible to see another object there in the same RCU grace period. 46 * 47 * This feature only ensures the memory location backing the object 48 * stays valid, the trick to using this is relying on an independent 49 * object validation pass. Something like: 50 * 51 * rcu_read_lock() 52 * again: 53 * obj = lockless_lookup(key); 54 * if (obj) { 55 * if (!try_get_ref(obj)) // might fail for free objects 56 * goto again; 57 * 58 * if (obj->key != key) { // not the object we expected 59 * put_ref(obj); 60 * goto again; 61 * } 62 * } 63 * rcu_read_unlock(); 64 * 65 * This is useful if we need to approach a kernel structure obliquely, 66 * from its address obtained without the usual locking. We can lock 67 * the structure to stabilize it and check it's still at the given address, 68 * only if we can be sure that the memory has not been meanwhile reused 69 * for some other kind of object (which our subsystem's lock might corrupt). 70 * 71 * rcu_read_lock before reading the address, then rcu_read_unlock after 72 * taking the spinlock within the structure expected at that address. 73 * 74 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. 75 */ 76 /* Defer freeing slabs to RCU */ 77 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U) 78 /* Spread some memory over cpuset */ 79 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U) 80 /* Trace allocations and frees */ 81 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U) 82 83 /* Flag to prevent checks on free */ 84 #ifdef CONFIG_DEBUG_OBJECTS 85 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U) 86 #else 87 # define SLAB_DEBUG_OBJECTS 0 88 #endif 89 90 /* Avoid kmemleak tracing */ 91 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U) 92 93 /* Fault injection mark */ 94 #ifdef CONFIG_FAILSLAB 95 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U) 96 #else 97 # define SLAB_FAILSLAB 0 98 #endif 99 /* Account to memcg */ 100 #ifdef CONFIG_MEMCG_KMEM 101 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U) 102 #else 103 # define SLAB_ACCOUNT 0 104 #endif 105 106 #ifdef CONFIG_KASAN 107 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U) 108 #else 109 #define SLAB_KASAN 0 110 #endif 111 112 /* The following flags affect the page allocator grouping pages by mobility */ 113 /* Objects are reclaimable */ 114 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) 115 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 116 /* 117 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 118 * 119 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 120 * 121 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 122 * Both make kfree a no-op. 123 */ 124 #define ZERO_SIZE_PTR ((void *)16) 125 126 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 127 (unsigned long)ZERO_SIZE_PTR) 128 129 #include <linux/kasan.h> 130 131 struct mem_cgroup; 132 /* 133 * struct kmem_cache related prototypes 134 */ 135 void __init kmem_cache_init(void); 136 bool slab_is_available(void); 137 138 extern bool usercopy_fallback; 139 140 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 141 unsigned int align, slab_flags_t flags, 142 void (*ctor)(void *)); 143 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 144 unsigned int size, unsigned int align, 145 slab_flags_t flags, 146 unsigned int useroffset, unsigned int usersize, 147 void (*ctor)(void *)); 148 void kmem_cache_destroy(struct kmem_cache *); 149 int kmem_cache_shrink(struct kmem_cache *); 150 151 void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *); 152 void memcg_deactivate_kmem_caches(struct mem_cgroup *); 153 void memcg_destroy_kmem_caches(struct mem_cgroup *); 154 155 /* 156 * Please use this macro to create slab caches. Simply specify the 157 * name of the structure and maybe some flags that are listed above. 158 * 159 * The alignment of the struct determines object alignment. If you 160 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 161 * then the objects will be properly aligned in SMP configurations. 162 */ 163 #define KMEM_CACHE(__struct, __flags) \ 164 kmem_cache_create(#__struct, sizeof(struct __struct), \ 165 __alignof__(struct __struct), (__flags), NULL) 166 167 /* 168 * To whitelist a single field for copying to/from usercopy, use this 169 * macro instead for KMEM_CACHE() above. 170 */ 171 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 172 kmem_cache_create_usercopy(#__struct, \ 173 sizeof(struct __struct), \ 174 __alignof__(struct __struct), (__flags), \ 175 offsetof(struct __struct, __field), \ 176 sizeof_field(struct __struct, __field), NULL) 177 178 /* 179 * Common kmalloc functions provided by all allocators 180 */ 181 void * __must_check __krealloc(const void *, size_t, gfp_t); 182 void * __must_check krealloc(const void *, size_t, gfp_t); 183 void kfree(const void *); 184 void kzfree(const void *); 185 size_t ksize(const void *); 186 187 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 188 void __check_heap_object(const void *ptr, unsigned long n, struct page *page, 189 bool to_user); 190 #else 191 static inline void __check_heap_object(const void *ptr, unsigned long n, 192 struct page *page, bool to_user) { } 193 #endif 194 195 /* 196 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 197 * alignment larger than the alignment of a 64-bit integer. 198 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. 199 */ 200 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 201 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 202 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 203 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 204 #else 205 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 206 #endif 207 208 /* 209 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 210 * Intended for arches that get misalignment faults even for 64 bit integer 211 * aligned buffers. 212 */ 213 #ifndef ARCH_SLAB_MINALIGN 214 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 215 #endif 216 217 /* 218 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned 219 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN 220 * aligned pointers. 221 */ 222 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 223 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 224 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 225 226 /* 227 * Kmalloc array related definitions 228 */ 229 230 #ifdef CONFIG_SLAB 231 /* 232 * The largest kmalloc size supported by the SLAB allocators is 233 * 32 megabyte (2^25) or the maximum allocatable page order if that is 234 * less than 32 MB. 235 * 236 * WARNING: Its not easy to increase this value since the allocators have 237 * to do various tricks to work around compiler limitations in order to 238 * ensure proper constant folding. 239 */ 240 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 241 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 242 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 243 #ifndef KMALLOC_SHIFT_LOW 244 #define KMALLOC_SHIFT_LOW 5 245 #endif 246 #endif 247 248 #ifdef CONFIG_SLUB 249 /* 250 * SLUB directly allocates requests fitting in to an order-1 page 251 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 252 */ 253 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 254 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 255 #ifndef KMALLOC_SHIFT_LOW 256 #define KMALLOC_SHIFT_LOW 3 257 #endif 258 #endif 259 260 #ifdef CONFIG_SLOB 261 /* 262 * SLOB passes all requests larger than one page to the page allocator. 263 * No kmalloc array is necessary since objects of different sizes can 264 * be allocated from the same page. 265 */ 266 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 267 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 268 #ifndef KMALLOC_SHIFT_LOW 269 #define KMALLOC_SHIFT_LOW 3 270 #endif 271 #endif 272 273 /* Maximum allocatable size */ 274 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 275 /* Maximum size for which we actually use a slab cache */ 276 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 277 /* Maximum order allocatable via the slab allocagtor */ 278 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 279 280 /* 281 * Kmalloc subsystem. 282 */ 283 #ifndef KMALLOC_MIN_SIZE 284 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 285 #endif 286 287 /* 288 * This restriction comes from byte sized index implementation. 289 * Page size is normally 2^12 bytes and, in this case, if we want to use 290 * byte sized index which can represent 2^8 entries, the size of the object 291 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 292 * If minimum size of kmalloc is less than 16, we use it as minimum object 293 * size and give up to use byte sized index. 294 */ 295 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 296 (KMALLOC_MIN_SIZE) : 16) 297 298 #ifndef CONFIG_SLOB 299 extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1]; 300 #ifdef CONFIG_ZONE_DMA 301 extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1]; 302 #endif 303 304 /* 305 * Figure out which kmalloc slab an allocation of a certain size 306 * belongs to. 307 * 0 = zero alloc 308 * 1 = 65 .. 96 bytes 309 * 2 = 129 .. 192 bytes 310 * n = 2^(n-1)+1 .. 2^n 311 */ 312 static __always_inline unsigned int kmalloc_index(size_t size) 313 { 314 if (!size) 315 return 0; 316 317 if (size <= KMALLOC_MIN_SIZE) 318 return KMALLOC_SHIFT_LOW; 319 320 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 321 return 1; 322 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 323 return 2; 324 if (size <= 8) return 3; 325 if (size <= 16) return 4; 326 if (size <= 32) return 5; 327 if (size <= 64) return 6; 328 if (size <= 128) return 7; 329 if (size <= 256) return 8; 330 if (size <= 512) return 9; 331 if (size <= 1024) return 10; 332 if (size <= 2 * 1024) return 11; 333 if (size <= 4 * 1024) return 12; 334 if (size <= 8 * 1024) return 13; 335 if (size <= 16 * 1024) return 14; 336 if (size <= 32 * 1024) return 15; 337 if (size <= 64 * 1024) return 16; 338 if (size <= 128 * 1024) return 17; 339 if (size <= 256 * 1024) return 18; 340 if (size <= 512 * 1024) return 19; 341 if (size <= 1024 * 1024) return 20; 342 if (size <= 2 * 1024 * 1024) return 21; 343 if (size <= 4 * 1024 * 1024) return 22; 344 if (size <= 8 * 1024 * 1024) return 23; 345 if (size <= 16 * 1024 * 1024) return 24; 346 if (size <= 32 * 1024 * 1024) return 25; 347 if (size <= 64 * 1024 * 1024) return 26; 348 BUG(); 349 350 /* Will never be reached. Needed because the compiler may complain */ 351 return -1; 352 } 353 #endif /* !CONFIG_SLOB */ 354 355 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc; 356 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc; 357 void kmem_cache_free(struct kmem_cache *, void *); 358 359 /* 360 * Bulk allocation and freeing operations. These are accelerated in an 361 * allocator specific way to avoid taking locks repeatedly or building 362 * metadata structures unnecessarily. 363 * 364 * Note that interrupts must be enabled when calling these functions. 365 */ 366 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 367 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 368 369 /* 370 * Caller must not use kfree_bulk() on memory not originally allocated 371 * by kmalloc(), because the SLOB allocator cannot handle this. 372 */ 373 static __always_inline void kfree_bulk(size_t size, void **p) 374 { 375 kmem_cache_free_bulk(NULL, size, p); 376 } 377 378 #ifdef CONFIG_NUMA 379 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc; 380 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc; 381 #else 382 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node) 383 { 384 return __kmalloc(size, flags); 385 } 386 387 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 388 { 389 return kmem_cache_alloc(s, flags); 390 } 391 #endif 392 393 #ifdef CONFIG_TRACING 394 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc; 395 396 #ifdef CONFIG_NUMA 397 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 398 gfp_t gfpflags, 399 int node, size_t size) __assume_slab_alignment __malloc; 400 #else 401 static __always_inline void * 402 kmem_cache_alloc_node_trace(struct kmem_cache *s, 403 gfp_t gfpflags, 404 int node, size_t size) 405 { 406 return kmem_cache_alloc_trace(s, gfpflags, size); 407 } 408 #endif /* CONFIG_NUMA */ 409 410 #else /* CONFIG_TRACING */ 411 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s, 412 gfp_t flags, size_t size) 413 { 414 void *ret = kmem_cache_alloc(s, flags); 415 416 kasan_kmalloc(s, ret, size, flags); 417 return ret; 418 } 419 420 static __always_inline void * 421 kmem_cache_alloc_node_trace(struct kmem_cache *s, 422 gfp_t gfpflags, 423 int node, size_t size) 424 { 425 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 426 427 kasan_kmalloc(s, ret, size, gfpflags); 428 return ret; 429 } 430 #endif /* CONFIG_TRACING */ 431 432 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 433 434 #ifdef CONFIG_TRACING 435 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 436 #else 437 static __always_inline void * 438 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 439 { 440 return kmalloc_order(size, flags, order); 441 } 442 #endif 443 444 static __always_inline void *kmalloc_large(size_t size, gfp_t flags) 445 { 446 unsigned int order = get_order(size); 447 return kmalloc_order_trace(size, flags, order); 448 } 449 450 /** 451 * kmalloc - allocate memory 452 * @size: how many bytes of memory are required. 453 * @flags: the type of memory to allocate. 454 * 455 * kmalloc is the normal method of allocating memory 456 * for objects smaller than page size in the kernel. 457 * 458 * The @flags argument may be one of: 459 * 460 * %GFP_USER - Allocate memory on behalf of user. May sleep. 461 * 462 * %GFP_KERNEL - Allocate normal kernel ram. May sleep. 463 * 464 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools. 465 * For example, use this inside interrupt handlers. 466 * 467 * %GFP_HIGHUSER - Allocate pages from high memory. 468 * 469 * %GFP_NOIO - Do not do any I/O at all while trying to get memory. 470 * 471 * %GFP_NOFS - Do not make any fs calls while trying to get memory. 472 * 473 * %GFP_NOWAIT - Allocation will not sleep. 474 * 475 * %__GFP_THISNODE - Allocate node-local memory only. 476 * 477 * %GFP_DMA - Allocation suitable for DMA. 478 * Should only be used for kmalloc() caches. Otherwise, use a 479 * slab created with SLAB_DMA. 480 * 481 * Also it is possible to set different flags by OR'ing 482 * in one or more of the following additional @flags: 483 * 484 * %__GFP_HIGH - This allocation has high priority and may use emergency pools. 485 * 486 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail 487 * (think twice before using). 488 * 489 * %__GFP_NORETRY - If memory is not immediately available, 490 * then give up at once. 491 * 492 * %__GFP_NOWARN - If allocation fails, don't issue any warnings. 493 * 494 * %__GFP_RETRY_MAYFAIL - Try really hard to succeed the allocation but fail 495 * eventually. 496 * 497 * There are other flags available as well, but these are not intended 498 * for general use, and so are not documented here. For a full list of 499 * potential flags, always refer to linux/gfp.h. 500 */ 501 static __always_inline void *kmalloc(size_t size, gfp_t flags) 502 { 503 if (__builtin_constant_p(size)) { 504 if (size > KMALLOC_MAX_CACHE_SIZE) 505 return kmalloc_large(size, flags); 506 #ifndef CONFIG_SLOB 507 if (!(flags & GFP_DMA)) { 508 unsigned int index = kmalloc_index(size); 509 510 if (!index) 511 return ZERO_SIZE_PTR; 512 513 return kmem_cache_alloc_trace(kmalloc_caches[index], 514 flags, size); 515 } 516 #endif 517 } 518 return __kmalloc(size, flags); 519 } 520 521 /* 522 * Determine size used for the nth kmalloc cache. 523 * return size or 0 if a kmalloc cache for that 524 * size does not exist 525 */ 526 static __always_inline unsigned int kmalloc_size(unsigned int n) 527 { 528 #ifndef CONFIG_SLOB 529 if (n > 2) 530 return 1U << n; 531 532 if (n == 1 && KMALLOC_MIN_SIZE <= 32) 533 return 96; 534 535 if (n == 2 && KMALLOC_MIN_SIZE <= 64) 536 return 192; 537 #endif 538 return 0; 539 } 540 541 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) 542 { 543 #ifndef CONFIG_SLOB 544 if (__builtin_constant_p(size) && 545 size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) { 546 unsigned int i = kmalloc_index(size); 547 548 if (!i) 549 return ZERO_SIZE_PTR; 550 551 return kmem_cache_alloc_node_trace(kmalloc_caches[i], 552 flags, node, size); 553 } 554 #endif 555 return __kmalloc_node(size, flags, node); 556 } 557 558 struct memcg_cache_array { 559 struct rcu_head rcu; 560 struct kmem_cache *entries[0]; 561 }; 562 563 /* 564 * This is the main placeholder for memcg-related information in kmem caches. 565 * Both the root cache and the child caches will have it. For the root cache, 566 * this will hold a dynamically allocated array large enough to hold 567 * information about the currently limited memcgs in the system. To allow the 568 * array to be accessed without taking any locks, on relocation we free the old 569 * version only after a grace period. 570 * 571 * Root and child caches hold different metadata. 572 * 573 * @root_cache: Common to root and child caches. NULL for root, pointer to 574 * the root cache for children. 575 * 576 * The following fields are specific to root caches. 577 * 578 * @memcg_caches: kmemcg ID indexed table of child caches. This table is 579 * used to index child cachces during allocation and cleared 580 * early during shutdown. 581 * 582 * @root_caches_node: List node for slab_root_caches list. 583 * 584 * @children: List of all child caches. While the child caches are also 585 * reachable through @memcg_caches, a child cache remains on 586 * this list until it is actually destroyed. 587 * 588 * The following fields are specific to child caches. 589 * 590 * @memcg: Pointer to the memcg this cache belongs to. 591 * 592 * @children_node: List node for @root_cache->children list. 593 * 594 * @kmem_caches_node: List node for @memcg->kmem_caches list. 595 */ 596 struct memcg_cache_params { 597 struct kmem_cache *root_cache; 598 union { 599 struct { 600 struct memcg_cache_array __rcu *memcg_caches; 601 struct list_head __root_caches_node; 602 struct list_head children; 603 bool dying; 604 }; 605 struct { 606 struct mem_cgroup *memcg; 607 struct list_head children_node; 608 struct list_head kmem_caches_node; 609 610 void (*deact_fn)(struct kmem_cache *); 611 union { 612 struct rcu_head deact_rcu_head; 613 struct work_struct deact_work; 614 }; 615 }; 616 }; 617 }; 618 619 int memcg_update_all_caches(int num_memcgs); 620 621 /** 622 * kmalloc_array - allocate memory for an array. 623 * @n: number of elements. 624 * @size: element size. 625 * @flags: the type of memory to allocate (see kmalloc). 626 */ 627 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) 628 { 629 size_t bytes; 630 631 if (unlikely(check_mul_overflow(n, size, &bytes))) 632 return NULL; 633 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 634 return kmalloc(bytes, flags); 635 return __kmalloc(bytes, flags); 636 } 637 638 /** 639 * kcalloc - allocate memory for an array. The memory is set to zero. 640 * @n: number of elements. 641 * @size: element size. 642 * @flags: the type of memory to allocate (see kmalloc). 643 */ 644 static inline void *kcalloc(size_t n, size_t size, gfp_t flags) 645 { 646 return kmalloc_array(n, size, flags | __GFP_ZERO); 647 } 648 649 /* 650 * kmalloc_track_caller is a special version of kmalloc that records the 651 * calling function of the routine calling it for slab leak tracking instead 652 * of just the calling function (confusing, eh?). 653 * It's useful when the call to kmalloc comes from a widely-used standard 654 * allocator where we care about the real place the memory allocation 655 * request comes from. 656 */ 657 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long); 658 #define kmalloc_track_caller(size, flags) \ 659 __kmalloc_track_caller(size, flags, _RET_IP_) 660 661 static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 662 int node) 663 { 664 size_t bytes; 665 666 if (unlikely(check_mul_overflow(n, size, &bytes))) 667 return NULL; 668 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 669 return kmalloc_node(bytes, flags, node); 670 return __kmalloc_node(bytes, flags, node); 671 } 672 673 static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 674 { 675 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 676 } 677 678 679 #ifdef CONFIG_NUMA 680 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long); 681 #define kmalloc_node_track_caller(size, flags, node) \ 682 __kmalloc_node_track_caller(size, flags, node, \ 683 _RET_IP_) 684 685 #else /* CONFIG_NUMA */ 686 687 #define kmalloc_node_track_caller(size, flags, node) \ 688 kmalloc_track_caller(size, flags) 689 690 #endif /* CONFIG_NUMA */ 691 692 /* 693 * Shortcuts 694 */ 695 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 696 { 697 return kmem_cache_alloc(k, flags | __GFP_ZERO); 698 } 699 700 /** 701 * kzalloc - allocate memory. The memory is set to zero. 702 * @size: how many bytes of memory are required. 703 * @flags: the type of memory to allocate (see kmalloc). 704 */ 705 static inline void *kzalloc(size_t size, gfp_t flags) 706 { 707 return kmalloc(size, flags | __GFP_ZERO); 708 } 709 710 /** 711 * kzalloc_node - allocate zeroed memory from a particular memory node. 712 * @size: how many bytes of memory are required. 713 * @flags: the type of memory to allocate (see kmalloc). 714 * @node: memory node from which to allocate 715 */ 716 static inline void *kzalloc_node(size_t size, gfp_t flags, int node) 717 { 718 return kmalloc_node(size, flags | __GFP_ZERO, node); 719 } 720 721 unsigned int kmem_cache_size(struct kmem_cache *s); 722 void __init kmem_cache_init_late(void); 723 724 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 725 int slab_prepare_cpu(unsigned int cpu); 726 int slab_dead_cpu(unsigned int cpu); 727 #else 728 #define slab_prepare_cpu NULL 729 #define slab_dead_cpu NULL 730 #endif 731 732 #endif /* _LINUX_SLAB_H */ 733