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 #include <linux/percpu-refcount.h> 20 21 22 /* 23 * Flags to pass to kmem_cache_create(). 24 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set. 25 */ 26 /* DEBUG: Perform (expensive) checks on alloc/free */ 27 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U) 28 /* DEBUG: Red zone objs in a cache */ 29 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U) 30 /* DEBUG: Poison objects */ 31 #define SLAB_POISON ((slab_flags_t __force)0x00000800U) 32 /* Align objs on cache lines */ 33 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U) 34 /* Use GFP_DMA memory */ 35 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U) 36 /* Use GFP_DMA32 memory */ 37 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U) 38 /* DEBUG: Store the last owner for bug hunting */ 39 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U) 40 /* Panic if kmem_cache_create() fails */ 41 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U) 42 /* 43 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS! 44 * 45 * This delays freeing the SLAB page by a grace period, it does _NOT_ 46 * delay object freeing. This means that if you do kmem_cache_free() 47 * that memory location is free to be reused at any time. Thus it may 48 * be possible to see another object there in the same RCU grace period. 49 * 50 * This feature only ensures the memory location backing the object 51 * stays valid, the trick to using this is relying on an independent 52 * object validation pass. Something like: 53 * 54 * rcu_read_lock() 55 * again: 56 * obj = lockless_lookup(key); 57 * if (obj) { 58 * if (!try_get_ref(obj)) // might fail for free objects 59 * goto again; 60 * 61 * if (obj->key != key) { // not the object we expected 62 * put_ref(obj); 63 * goto again; 64 * } 65 * } 66 * rcu_read_unlock(); 67 * 68 * This is useful if we need to approach a kernel structure obliquely, 69 * from its address obtained without the usual locking. We can lock 70 * the structure to stabilize it and check it's still at the given address, 71 * only if we can be sure that the memory has not been meanwhile reused 72 * for some other kind of object (which our subsystem's lock might corrupt). 73 * 74 * rcu_read_lock before reading the address, then rcu_read_unlock after 75 * taking the spinlock within the structure expected at that address. 76 * 77 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. 78 */ 79 /* Defer freeing slabs to RCU */ 80 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U) 81 /* Spread some memory over cpuset */ 82 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U) 83 /* Trace allocations and frees */ 84 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U) 85 86 /* Flag to prevent checks on free */ 87 #ifdef CONFIG_DEBUG_OBJECTS 88 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U) 89 #else 90 # define SLAB_DEBUG_OBJECTS 0 91 #endif 92 93 /* Avoid kmemleak tracing */ 94 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U) 95 96 /* Fault injection mark */ 97 #ifdef CONFIG_FAILSLAB 98 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U) 99 #else 100 # define SLAB_FAILSLAB 0 101 #endif 102 /* Account to memcg */ 103 #ifdef CONFIG_MEMCG_KMEM 104 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U) 105 #else 106 # define SLAB_ACCOUNT 0 107 #endif 108 109 #ifdef CONFIG_KASAN 110 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U) 111 #else 112 #define SLAB_KASAN 0 113 #endif 114 115 /* The following flags affect the page allocator grouping pages by mobility */ 116 /* Objects are reclaimable */ 117 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) 118 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 119 120 /* Slab deactivation flag */ 121 #define SLAB_DEACTIVATED ((slab_flags_t __force)0x10000000U) 122 123 /* 124 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 125 * 126 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 127 * 128 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 129 * Both make kfree a no-op. 130 */ 131 #define ZERO_SIZE_PTR ((void *)16) 132 133 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 134 (unsigned long)ZERO_SIZE_PTR) 135 136 #include <linux/kasan.h> 137 138 struct mem_cgroup; 139 /* 140 * struct kmem_cache related prototypes 141 */ 142 void __init kmem_cache_init(void); 143 bool slab_is_available(void); 144 145 extern bool usercopy_fallback; 146 147 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 148 unsigned int align, slab_flags_t flags, 149 void (*ctor)(void *)); 150 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 151 unsigned int size, unsigned int align, 152 slab_flags_t flags, 153 unsigned int useroffset, unsigned int usersize, 154 void (*ctor)(void *)); 155 void kmem_cache_destroy(struct kmem_cache *); 156 int kmem_cache_shrink(struct kmem_cache *); 157 158 void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *); 159 void memcg_deactivate_kmem_caches(struct mem_cgroup *, struct mem_cgroup *); 160 161 /* 162 * Please use this macro to create slab caches. Simply specify the 163 * name of the structure and maybe some flags that are listed above. 164 * 165 * The alignment of the struct determines object alignment. If you 166 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 167 * then the objects will be properly aligned in SMP configurations. 168 */ 169 #define KMEM_CACHE(__struct, __flags) \ 170 kmem_cache_create(#__struct, sizeof(struct __struct), \ 171 __alignof__(struct __struct), (__flags), NULL) 172 173 /* 174 * To whitelist a single field for copying to/from usercopy, use this 175 * macro instead for KMEM_CACHE() above. 176 */ 177 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 178 kmem_cache_create_usercopy(#__struct, \ 179 sizeof(struct __struct), \ 180 __alignof__(struct __struct), (__flags), \ 181 offsetof(struct __struct, __field), \ 182 sizeof_field(struct __struct, __field), NULL) 183 184 /* 185 * Common kmalloc functions provided by all allocators 186 */ 187 void * __must_check krealloc(const void *, size_t, gfp_t); 188 void kfree(const void *); 189 void kzfree(const void *); 190 size_t __ksize(const void *); 191 size_t ksize(const void *); 192 193 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 194 void __check_heap_object(const void *ptr, unsigned long n, struct page *page, 195 bool to_user); 196 #else 197 static inline void __check_heap_object(const void *ptr, unsigned long n, 198 struct page *page, bool to_user) { } 199 #endif 200 201 /* 202 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 203 * alignment larger than the alignment of a 64-bit integer. 204 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. 205 */ 206 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 207 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 208 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 209 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 210 #else 211 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 212 #endif 213 214 /* 215 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 216 * Intended for arches that get misalignment faults even for 64 bit integer 217 * aligned buffers. 218 */ 219 #ifndef ARCH_SLAB_MINALIGN 220 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 221 #endif 222 223 /* 224 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned 225 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN 226 * aligned pointers. 227 */ 228 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 229 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 230 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 231 232 /* 233 * Kmalloc array related definitions 234 */ 235 236 #ifdef CONFIG_SLAB 237 /* 238 * The largest kmalloc size supported by the SLAB allocators is 239 * 32 megabyte (2^25) or the maximum allocatable page order if that is 240 * less than 32 MB. 241 * 242 * WARNING: Its not easy to increase this value since the allocators have 243 * to do various tricks to work around compiler limitations in order to 244 * ensure proper constant folding. 245 */ 246 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 247 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 248 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 249 #ifndef KMALLOC_SHIFT_LOW 250 #define KMALLOC_SHIFT_LOW 5 251 #endif 252 #endif 253 254 #ifdef CONFIG_SLUB 255 /* 256 * SLUB directly allocates requests fitting in to an order-1 page 257 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 258 */ 259 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 260 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 261 #ifndef KMALLOC_SHIFT_LOW 262 #define KMALLOC_SHIFT_LOW 3 263 #endif 264 #endif 265 266 #ifdef CONFIG_SLOB 267 /* 268 * SLOB passes all requests larger than one page to the page allocator. 269 * No kmalloc array is necessary since objects of different sizes can 270 * be allocated from the same page. 271 */ 272 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 273 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 274 #ifndef KMALLOC_SHIFT_LOW 275 #define KMALLOC_SHIFT_LOW 3 276 #endif 277 #endif 278 279 /* Maximum allocatable size */ 280 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 281 /* Maximum size for which we actually use a slab cache */ 282 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 283 /* Maximum order allocatable via the slab allocagtor */ 284 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 285 286 /* 287 * Kmalloc subsystem. 288 */ 289 #ifndef KMALLOC_MIN_SIZE 290 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 291 #endif 292 293 /* 294 * This restriction comes from byte sized index implementation. 295 * Page size is normally 2^12 bytes and, in this case, if we want to use 296 * byte sized index which can represent 2^8 entries, the size of the object 297 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 298 * If minimum size of kmalloc is less than 16, we use it as minimum object 299 * size and give up to use byte sized index. 300 */ 301 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 302 (KMALLOC_MIN_SIZE) : 16) 303 304 /* 305 * Whenever changing this, take care of that kmalloc_type() and 306 * create_kmalloc_caches() still work as intended. 307 */ 308 enum kmalloc_cache_type { 309 KMALLOC_NORMAL = 0, 310 KMALLOC_RECLAIM, 311 #ifdef CONFIG_ZONE_DMA 312 KMALLOC_DMA, 313 #endif 314 NR_KMALLOC_TYPES 315 }; 316 317 #ifndef CONFIG_SLOB 318 extern struct kmem_cache * 319 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 320 321 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 322 { 323 #ifdef CONFIG_ZONE_DMA 324 /* 325 * The most common case is KMALLOC_NORMAL, so test for it 326 * with a single branch for both flags. 327 */ 328 if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0)) 329 return KMALLOC_NORMAL; 330 331 /* 332 * At least one of the flags has to be set. If both are, __GFP_DMA 333 * is more important. 334 */ 335 return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM; 336 #else 337 return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL; 338 #endif 339 } 340 341 /* 342 * Figure out which kmalloc slab an allocation of a certain size 343 * belongs to. 344 * 0 = zero alloc 345 * 1 = 65 .. 96 bytes 346 * 2 = 129 .. 192 bytes 347 * n = 2^(n-1)+1 .. 2^n 348 */ 349 static __always_inline unsigned int kmalloc_index(size_t size) 350 { 351 if (!size) 352 return 0; 353 354 if (size <= KMALLOC_MIN_SIZE) 355 return KMALLOC_SHIFT_LOW; 356 357 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 358 return 1; 359 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 360 return 2; 361 if (size <= 8) return 3; 362 if (size <= 16) return 4; 363 if (size <= 32) return 5; 364 if (size <= 64) return 6; 365 if (size <= 128) return 7; 366 if (size <= 256) return 8; 367 if (size <= 512) return 9; 368 if (size <= 1024) return 10; 369 if (size <= 2 * 1024) return 11; 370 if (size <= 4 * 1024) return 12; 371 if (size <= 8 * 1024) return 13; 372 if (size <= 16 * 1024) return 14; 373 if (size <= 32 * 1024) return 15; 374 if (size <= 64 * 1024) return 16; 375 if (size <= 128 * 1024) return 17; 376 if (size <= 256 * 1024) return 18; 377 if (size <= 512 * 1024) return 19; 378 if (size <= 1024 * 1024) return 20; 379 if (size <= 2 * 1024 * 1024) return 21; 380 if (size <= 4 * 1024 * 1024) return 22; 381 if (size <= 8 * 1024 * 1024) return 23; 382 if (size <= 16 * 1024 * 1024) return 24; 383 if (size <= 32 * 1024 * 1024) return 25; 384 if (size <= 64 * 1024 * 1024) return 26; 385 BUG(); 386 387 /* Will never be reached. Needed because the compiler may complain */ 388 return -1; 389 } 390 #endif /* !CONFIG_SLOB */ 391 392 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc; 393 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc; 394 void kmem_cache_free(struct kmem_cache *, void *); 395 396 /* 397 * Bulk allocation and freeing operations. These are accelerated in an 398 * allocator specific way to avoid taking locks repeatedly or building 399 * metadata structures unnecessarily. 400 * 401 * Note that interrupts must be enabled when calling these functions. 402 */ 403 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 404 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 405 406 /* 407 * Caller must not use kfree_bulk() on memory not originally allocated 408 * by kmalloc(), because the SLOB allocator cannot handle this. 409 */ 410 static __always_inline void kfree_bulk(size_t size, void **p) 411 { 412 kmem_cache_free_bulk(NULL, size, p); 413 } 414 415 #ifdef CONFIG_NUMA 416 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc; 417 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc; 418 #else 419 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node) 420 { 421 return __kmalloc(size, flags); 422 } 423 424 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 425 { 426 return kmem_cache_alloc(s, flags); 427 } 428 #endif 429 430 #ifdef CONFIG_TRACING 431 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc; 432 433 #ifdef CONFIG_NUMA 434 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 435 gfp_t gfpflags, 436 int node, size_t size) __assume_slab_alignment __malloc; 437 #else 438 static __always_inline void * 439 kmem_cache_alloc_node_trace(struct kmem_cache *s, 440 gfp_t gfpflags, 441 int node, size_t size) 442 { 443 return kmem_cache_alloc_trace(s, gfpflags, size); 444 } 445 #endif /* CONFIG_NUMA */ 446 447 #else /* CONFIG_TRACING */ 448 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s, 449 gfp_t flags, size_t size) 450 { 451 void *ret = kmem_cache_alloc(s, flags); 452 453 ret = kasan_kmalloc(s, ret, size, flags); 454 return ret; 455 } 456 457 static __always_inline void * 458 kmem_cache_alloc_node_trace(struct kmem_cache *s, 459 gfp_t gfpflags, 460 int node, size_t size) 461 { 462 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 463 464 ret = kasan_kmalloc(s, ret, size, gfpflags); 465 return ret; 466 } 467 #endif /* CONFIG_TRACING */ 468 469 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 470 471 #ifdef CONFIG_TRACING 472 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 473 #else 474 static __always_inline void * 475 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 476 { 477 return kmalloc_order(size, flags, order); 478 } 479 #endif 480 481 static __always_inline void *kmalloc_large(size_t size, gfp_t flags) 482 { 483 unsigned int order = get_order(size); 484 return kmalloc_order_trace(size, flags, order); 485 } 486 487 /** 488 * kmalloc - allocate memory 489 * @size: how many bytes of memory are required. 490 * @flags: the type of memory to allocate. 491 * 492 * kmalloc is the normal method of allocating memory 493 * for objects smaller than page size in the kernel. 494 * 495 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 496 * bytes. For @size of power of two bytes, the alignment is also guaranteed 497 * to be at least to the size. 498 * 499 * The @flags argument may be one of the GFP flags defined at 500 * include/linux/gfp.h and described at 501 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 502 * 503 * The recommended usage of the @flags is described at 504 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 505 * 506 * Below is a brief outline of the most useful GFP flags 507 * 508 * %GFP_KERNEL 509 * Allocate normal kernel ram. May sleep. 510 * 511 * %GFP_NOWAIT 512 * Allocation will not sleep. 513 * 514 * %GFP_ATOMIC 515 * Allocation will not sleep. May use emergency pools. 516 * 517 * %GFP_HIGHUSER 518 * Allocate memory from high memory on behalf of user. 519 * 520 * Also it is possible to set different flags by OR'ing 521 * in one or more of the following additional @flags: 522 * 523 * %__GFP_HIGH 524 * This allocation has high priority and may use emergency pools. 525 * 526 * %__GFP_NOFAIL 527 * Indicate that this allocation is in no way allowed to fail 528 * (think twice before using). 529 * 530 * %__GFP_NORETRY 531 * If memory is not immediately available, 532 * then give up at once. 533 * 534 * %__GFP_NOWARN 535 * If allocation fails, don't issue any warnings. 536 * 537 * %__GFP_RETRY_MAYFAIL 538 * Try really hard to succeed the allocation but fail 539 * eventually. 540 */ 541 static __always_inline void *kmalloc(size_t size, gfp_t flags) 542 { 543 if (__builtin_constant_p(size)) { 544 #ifndef CONFIG_SLOB 545 unsigned int index; 546 #endif 547 if (size > KMALLOC_MAX_CACHE_SIZE) 548 return kmalloc_large(size, flags); 549 #ifndef CONFIG_SLOB 550 index = kmalloc_index(size); 551 552 if (!index) 553 return ZERO_SIZE_PTR; 554 555 return kmem_cache_alloc_trace( 556 kmalloc_caches[kmalloc_type(flags)][index], 557 flags, size); 558 #endif 559 } 560 return __kmalloc(size, flags); 561 } 562 563 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) 564 { 565 #ifndef CONFIG_SLOB 566 if (__builtin_constant_p(size) && 567 size <= KMALLOC_MAX_CACHE_SIZE) { 568 unsigned int i = kmalloc_index(size); 569 570 if (!i) 571 return ZERO_SIZE_PTR; 572 573 return kmem_cache_alloc_node_trace( 574 kmalloc_caches[kmalloc_type(flags)][i], 575 flags, node, size); 576 } 577 #endif 578 return __kmalloc_node(size, flags, node); 579 } 580 581 int memcg_update_all_caches(int num_memcgs); 582 583 /** 584 * kmalloc_array - allocate memory for an array. 585 * @n: number of elements. 586 * @size: element size. 587 * @flags: the type of memory to allocate (see kmalloc). 588 */ 589 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) 590 { 591 size_t bytes; 592 593 if (unlikely(check_mul_overflow(n, size, &bytes))) 594 return NULL; 595 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 596 return kmalloc(bytes, flags); 597 return __kmalloc(bytes, flags); 598 } 599 600 /** 601 * kcalloc - allocate memory for an array. The memory is set to zero. 602 * @n: number of elements. 603 * @size: element size. 604 * @flags: the type of memory to allocate (see kmalloc). 605 */ 606 static inline void *kcalloc(size_t n, size_t size, gfp_t flags) 607 { 608 return kmalloc_array(n, size, flags | __GFP_ZERO); 609 } 610 611 /* 612 * kmalloc_track_caller is a special version of kmalloc that records the 613 * calling function of the routine calling it for slab leak tracking instead 614 * of just the calling function (confusing, eh?). 615 * It's useful when the call to kmalloc comes from a widely-used standard 616 * allocator where we care about the real place the memory allocation 617 * request comes from. 618 */ 619 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long); 620 #define kmalloc_track_caller(size, flags) \ 621 __kmalloc_track_caller(size, flags, _RET_IP_) 622 623 static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 624 int node) 625 { 626 size_t bytes; 627 628 if (unlikely(check_mul_overflow(n, size, &bytes))) 629 return NULL; 630 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 631 return kmalloc_node(bytes, flags, node); 632 return __kmalloc_node(bytes, flags, node); 633 } 634 635 static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 636 { 637 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 638 } 639 640 641 #ifdef CONFIG_NUMA 642 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long); 643 #define kmalloc_node_track_caller(size, flags, node) \ 644 __kmalloc_node_track_caller(size, flags, node, \ 645 _RET_IP_) 646 647 #else /* CONFIG_NUMA */ 648 649 #define kmalloc_node_track_caller(size, flags, node) \ 650 kmalloc_track_caller(size, flags) 651 652 #endif /* CONFIG_NUMA */ 653 654 /* 655 * Shortcuts 656 */ 657 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 658 { 659 return kmem_cache_alloc(k, flags | __GFP_ZERO); 660 } 661 662 /** 663 * kzalloc - allocate memory. The memory is set to zero. 664 * @size: how many bytes of memory are required. 665 * @flags: the type of memory to allocate (see kmalloc). 666 */ 667 static inline void *kzalloc(size_t size, gfp_t flags) 668 { 669 return kmalloc(size, flags | __GFP_ZERO); 670 } 671 672 /** 673 * kzalloc_node - allocate zeroed memory from a particular memory node. 674 * @size: how many bytes of memory are required. 675 * @flags: the type of memory to allocate (see kmalloc). 676 * @node: memory node from which to allocate 677 */ 678 static inline void *kzalloc_node(size_t size, gfp_t flags, int node) 679 { 680 return kmalloc_node(size, flags | __GFP_ZERO, node); 681 } 682 683 unsigned int kmem_cache_size(struct kmem_cache *s); 684 void __init kmem_cache_init_late(void); 685 686 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 687 int slab_prepare_cpu(unsigned int cpu); 688 int slab_dead_cpu(unsigned int cpu); 689 #else 690 #define slab_prepare_cpu NULL 691 #define slab_dead_cpu NULL 692 #endif 693 694 #endif /* _LINUX_SLAB_H */ 695