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 /* 159 * Please use this macro to create slab caches. Simply specify the 160 * name of the structure and maybe some flags that are listed above. 161 * 162 * The alignment of the struct determines object alignment. If you 163 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 164 * then the objects will be properly aligned in SMP configurations. 165 */ 166 #define KMEM_CACHE(__struct, __flags) \ 167 kmem_cache_create(#__struct, sizeof(struct __struct), \ 168 __alignof__(struct __struct), (__flags), NULL) 169 170 /* 171 * To whitelist a single field for copying to/from usercopy, use this 172 * macro instead for KMEM_CACHE() above. 173 */ 174 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 175 kmem_cache_create_usercopy(#__struct, \ 176 sizeof(struct __struct), \ 177 __alignof__(struct __struct), (__flags), \ 178 offsetof(struct __struct, __field), \ 179 sizeof_field(struct __struct, __field), NULL) 180 181 /* 182 * Common kmalloc functions provided by all allocators 183 */ 184 void * __must_check krealloc(const void *, size_t, gfp_t); 185 void kfree(const void *); 186 void kfree_sensitive(const void *); 187 size_t __ksize(const void *); 188 size_t ksize(const void *); 189 bool kmem_valid_obj(void *object); 190 void kmem_dump_obj(void *object); 191 192 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 193 void __check_heap_object(const void *ptr, unsigned long n, struct page *page, 194 bool to_user); 195 #else 196 static inline void __check_heap_object(const void *ptr, unsigned long n, 197 struct page *page, bool to_user) { } 198 #endif 199 200 /* 201 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 202 * alignment larger than the alignment of a 64-bit integer. 203 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. 204 */ 205 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 206 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 207 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 208 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 209 #else 210 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 211 #endif 212 213 /* 214 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 215 * Intended for arches that get misalignment faults even for 64 bit integer 216 * aligned buffers. 217 */ 218 #ifndef ARCH_SLAB_MINALIGN 219 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 220 #endif 221 222 /* 223 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned 224 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN 225 * aligned pointers. 226 */ 227 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 228 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 229 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 230 231 /* 232 * Kmalloc array related definitions 233 */ 234 235 #ifdef CONFIG_SLAB 236 /* 237 * The largest kmalloc size supported by the SLAB allocators is 238 * 32 megabyte (2^25) or the maximum allocatable page order if that is 239 * less than 32 MB. 240 * 241 * WARNING: Its not easy to increase this value since the allocators have 242 * to do various tricks to work around compiler limitations in order to 243 * ensure proper constant folding. 244 */ 245 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 246 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 247 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 248 #ifndef KMALLOC_SHIFT_LOW 249 #define KMALLOC_SHIFT_LOW 5 250 #endif 251 #endif 252 253 #ifdef CONFIG_SLUB 254 /* 255 * SLUB directly allocates requests fitting in to an order-1 page 256 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 257 */ 258 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 259 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 260 #ifndef KMALLOC_SHIFT_LOW 261 #define KMALLOC_SHIFT_LOW 3 262 #endif 263 #endif 264 265 #ifdef CONFIG_SLOB 266 /* 267 * SLOB passes all requests larger than one page to the page allocator. 268 * No kmalloc array is necessary since objects of different sizes can 269 * be allocated from the same page. 270 */ 271 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 272 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 273 #ifndef KMALLOC_SHIFT_LOW 274 #define KMALLOC_SHIFT_LOW 3 275 #endif 276 #endif 277 278 /* Maximum allocatable size */ 279 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 280 /* Maximum size for which we actually use a slab cache */ 281 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 282 /* Maximum order allocatable via the slab allocator */ 283 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 284 285 /* 286 * Kmalloc subsystem. 287 */ 288 #ifndef KMALLOC_MIN_SIZE 289 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 290 #endif 291 292 /* 293 * This restriction comes from byte sized index implementation. 294 * Page size is normally 2^12 bytes and, in this case, if we want to use 295 * byte sized index which can represent 2^8 entries, the size of the object 296 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 297 * If minimum size of kmalloc is less than 16, we use it as minimum object 298 * size and give up to use byte sized index. 299 */ 300 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 301 (KMALLOC_MIN_SIZE) : 16) 302 303 /* 304 * Whenever changing this, take care of that kmalloc_type() and 305 * create_kmalloc_caches() still work as intended. 306 */ 307 enum kmalloc_cache_type { 308 KMALLOC_NORMAL = 0, 309 KMALLOC_RECLAIM, 310 #ifdef CONFIG_ZONE_DMA 311 KMALLOC_DMA, 312 #endif 313 NR_KMALLOC_TYPES 314 }; 315 316 #ifndef CONFIG_SLOB 317 extern struct kmem_cache * 318 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 319 320 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 321 { 322 #ifdef CONFIG_ZONE_DMA 323 /* 324 * The most common case is KMALLOC_NORMAL, so test for it 325 * with a single branch for both flags. 326 */ 327 if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0)) 328 return KMALLOC_NORMAL; 329 330 /* 331 * At least one of the flags has to be set. If both are, __GFP_DMA 332 * is more important. 333 */ 334 return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM; 335 #else 336 return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL; 337 #endif 338 } 339 340 /* 341 * Figure out which kmalloc slab an allocation of a certain size 342 * belongs to. 343 * 0 = zero alloc 344 * 1 = 65 .. 96 bytes 345 * 2 = 129 .. 192 bytes 346 * n = 2^(n-1)+1 .. 2^n 347 */ 348 static __always_inline unsigned int kmalloc_index(size_t size) 349 { 350 if (!size) 351 return 0; 352 353 if (size <= KMALLOC_MIN_SIZE) 354 return KMALLOC_SHIFT_LOW; 355 356 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 357 return 1; 358 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 359 return 2; 360 if (size <= 8) return 3; 361 if (size <= 16) return 4; 362 if (size <= 32) return 5; 363 if (size <= 64) return 6; 364 if (size <= 128) return 7; 365 if (size <= 256) return 8; 366 if (size <= 512) return 9; 367 if (size <= 1024) return 10; 368 if (size <= 2 * 1024) return 11; 369 if (size <= 4 * 1024) return 12; 370 if (size <= 8 * 1024) return 13; 371 if (size <= 16 * 1024) return 14; 372 if (size <= 32 * 1024) return 15; 373 if (size <= 64 * 1024) return 16; 374 if (size <= 128 * 1024) return 17; 375 if (size <= 256 * 1024) return 18; 376 if (size <= 512 * 1024) return 19; 377 if (size <= 1024 * 1024) return 20; 378 if (size <= 2 * 1024 * 1024) return 21; 379 if (size <= 4 * 1024 * 1024) return 22; 380 if (size <= 8 * 1024 * 1024) return 23; 381 if (size <= 16 * 1024 * 1024) return 24; 382 if (size <= 32 * 1024 * 1024) return 25; 383 if (size <= 64 * 1024 * 1024) return 26; 384 BUG(); 385 386 /* Will never be reached. Needed because the compiler may complain */ 387 return -1; 388 } 389 #endif /* !CONFIG_SLOB */ 390 391 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc; 392 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc; 393 void kmem_cache_free(struct kmem_cache *, void *); 394 395 /* 396 * Bulk allocation and freeing operations. These are accelerated in an 397 * allocator specific way to avoid taking locks repeatedly or building 398 * metadata structures unnecessarily. 399 * 400 * Note that interrupts must be enabled when calling these functions. 401 */ 402 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 403 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 404 405 /* 406 * Caller must not use kfree_bulk() on memory not originally allocated 407 * by kmalloc(), because the SLOB allocator cannot handle this. 408 */ 409 static __always_inline void kfree_bulk(size_t size, void **p) 410 { 411 kmem_cache_free_bulk(NULL, size, p); 412 } 413 414 #ifdef CONFIG_NUMA 415 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc; 416 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc; 417 #else 418 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node) 419 { 420 return __kmalloc(size, flags); 421 } 422 423 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 424 { 425 return kmem_cache_alloc(s, flags); 426 } 427 #endif 428 429 #ifdef CONFIG_TRACING 430 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc; 431 432 #ifdef CONFIG_NUMA 433 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 434 gfp_t gfpflags, 435 int node, size_t size) __assume_slab_alignment __malloc; 436 #else 437 static __always_inline void * 438 kmem_cache_alloc_node_trace(struct kmem_cache *s, 439 gfp_t gfpflags, 440 int node, size_t size) 441 { 442 return kmem_cache_alloc_trace(s, gfpflags, size); 443 } 444 #endif /* CONFIG_NUMA */ 445 446 #else /* CONFIG_TRACING */ 447 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s, 448 gfp_t flags, size_t size) 449 { 450 void *ret = kmem_cache_alloc(s, flags); 451 452 ret = kasan_kmalloc(s, ret, size, flags); 453 return ret; 454 } 455 456 static __always_inline void * 457 kmem_cache_alloc_node_trace(struct kmem_cache *s, 458 gfp_t gfpflags, 459 int node, size_t size) 460 { 461 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 462 463 ret = kasan_kmalloc(s, ret, size, gfpflags); 464 return ret; 465 } 466 #endif /* CONFIG_TRACING */ 467 468 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 469 470 #ifdef CONFIG_TRACING 471 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 472 #else 473 static __always_inline void * 474 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 475 { 476 return kmalloc_order(size, flags, order); 477 } 478 #endif 479 480 static __always_inline void *kmalloc_large(size_t size, gfp_t flags) 481 { 482 unsigned int order = get_order(size); 483 return kmalloc_order_trace(size, flags, order); 484 } 485 486 /** 487 * kmalloc - allocate memory 488 * @size: how many bytes of memory are required. 489 * @flags: the type of memory to allocate. 490 * 491 * kmalloc is the normal method of allocating memory 492 * for objects smaller than page size in the kernel. 493 * 494 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 495 * bytes. For @size of power of two bytes, the alignment is also guaranteed 496 * to be at least to the size. 497 * 498 * The @flags argument may be one of the GFP flags defined at 499 * include/linux/gfp.h and described at 500 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 501 * 502 * The recommended usage of the @flags is described at 503 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 504 * 505 * Below is a brief outline of the most useful GFP flags 506 * 507 * %GFP_KERNEL 508 * Allocate normal kernel ram. May sleep. 509 * 510 * %GFP_NOWAIT 511 * Allocation will not sleep. 512 * 513 * %GFP_ATOMIC 514 * Allocation will not sleep. May use emergency pools. 515 * 516 * %GFP_HIGHUSER 517 * Allocate memory from high memory on behalf of user. 518 * 519 * Also it is possible to set different flags by OR'ing 520 * in one or more of the following additional @flags: 521 * 522 * %__GFP_HIGH 523 * This allocation has high priority and may use emergency pools. 524 * 525 * %__GFP_NOFAIL 526 * Indicate that this allocation is in no way allowed to fail 527 * (think twice before using). 528 * 529 * %__GFP_NORETRY 530 * If memory is not immediately available, 531 * then give up at once. 532 * 533 * %__GFP_NOWARN 534 * If allocation fails, don't issue any warnings. 535 * 536 * %__GFP_RETRY_MAYFAIL 537 * Try really hard to succeed the allocation but fail 538 * eventually. 539 */ 540 static __always_inline void *kmalloc(size_t size, gfp_t flags) 541 { 542 if (__builtin_constant_p(size)) { 543 #ifndef CONFIG_SLOB 544 unsigned int index; 545 #endif 546 if (size > KMALLOC_MAX_CACHE_SIZE) 547 return kmalloc_large(size, flags); 548 #ifndef CONFIG_SLOB 549 index = kmalloc_index(size); 550 551 if (!index) 552 return ZERO_SIZE_PTR; 553 554 return kmem_cache_alloc_trace( 555 kmalloc_caches[kmalloc_type(flags)][index], 556 flags, size); 557 #endif 558 } 559 return __kmalloc(size, flags); 560 } 561 562 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) 563 { 564 #ifndef CONFIG_SLOB 565 if (__builtin_constant_p(size) && 566 size <= KMALLOC_MAX_CACHE_SIZE) { 567 unsigned int i = kmalloc_index(size); 568 569 if (!i) 570 return ZERO_SIZE_PTR; 571 572 return kmem_cache_alloc_node_trace( 573 kmalloc_caches[kmalloc_type(flags)][i], 574 flags, node, size); 575 } 576 #endif 577 return __kmalloc_node(size, flags, node); 578 } 579 580 /** 581 * kmalloc_array - allocate memory for an array. 582 * @n: number of elements. 583 * @size: element size. 584 * @flags: the type of memory to allocate (see kmalloc). 585 */ 586 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) 587 { 588 size_t bytes; 589 590 if (unlikely(check_mul_overflow(n, size, &bytes))) 591 return NULL; 592 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 593 return kmalloc(bytes, flags); 594 return __kmalloc(bytes, flags); 595 } 596 597 /** 598 * krealloc_array - reallocate memory for an array. 599 * @p: pointer to the memory chunk to reallocate 600 * @new_n: new number of elements to alloc 601 * @new_size: new size of a single member of the array 602 * @flags: the type of memory to allocate (see kmalloc) 603 */ 604 static __must_check inline void * 605 krealloc_array(void *p, size_t new_n, size_t new_size, gfp_t flags) 606 { 607 size_t bytes; 608 609 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 610 return NULL; 611 612 return krealloc(p, bytes, 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 */ 621 static 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 */ 634 extern 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 static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 639 int node) 640 { 641 size_t bytes; 642 643 if (unlikely(check_mul_overflow(n, size, &bytes))) 644 return NULL; 645 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 646 return kmalloc_node(bytes, flags, node); 647 return __kmalloc_node(bytes, flags, node); 648 } 649 650 static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 651 { 652 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 653 } 654 655 656 #ifdef CONFIG_NUMA 657 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long); 658 #define kmalloc_node_track_caller(size, flags, node) \ 659 __kmalloc_node_track_caller(size, flags, node, \ 660 _RET_IP_) 661 662 #else /* CONFIG_NUMA */ 663 664 #define kmalloc_node_track_caller(size, flags, node) \ 665 kmalloc_track_caller(size, flags) 666 667 #endif /* CONFIG_NUMA */ 668 669 /* 670 * Shortcuts 671 */ 672 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 673 { 674 return kmem_cache_alloc(k, flags | __GFP_ZERO); 675 } 676 677 /** 678 * kzalloc - allocate memory. The memory is set to zero. 679 * @size: how many bytes of memory are required. 680 * @flags: the type of memory to allocate (see kmalloc). 681 */ 682 static inline void *kzalloc(size_t size, gfp_t flags) 683 { 684 return kmalloc(size, flags | __GFP_ZERO); 685 } 686 687 /** 688 * kzalloc_node - allocate zeroed memory from a particular memory node. 689 * @size: how many bytes of memory are required. 690 * @flags: the type of memory to allocate (see kmalloc). 691 * @node: memory node from which to allocate 692 */ 693 static inline void *kzalloc_node(size_t size, gfp_t flags, int node) 694 { 695 return kmalloc_node(size, flags | __GFP_ZERO, node); 696 } 697 698 unsigned int kmem_cache_size(struct kmem_cache *s); 699 void __init kmem_cache_init_late(void); 700 701 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 702 int slab_prepare_cpu(unsigned int cpu); 703 int slab_dead_cpu(unsigned int cpu); 704 #else 705 #define slab_prepare_cpu NULL 706 #define slab_dead_cpu NULL 707 #endif 708 709 #endif /* _LINUX_SLAB_H */ 710