1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Written by Mark Hemment, 1996 ([email protected]). 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 /* Indicate a kmalloc slab */ 33 #define SLAB_KMALLOC ((slab_flags_t __force)0x00001000U) 34 /* Align objs on cache lines */ 35 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U) 36 /* Use GFP_DMA memory */ 37 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U) 38 /* Use GFP_DMA32 memory */ 39 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U) 40 /* DEBUG: Store the last owner for bug hunting */ 41 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U) 42 /* Panic if kmem_cache_create() fails */ 43 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U) 44 /* 45 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS! 46 * 47 * This delays freeing the SLAB page by a grace period, it does _NOT_ 48 * delay object freeing. This means that if you do kmem_cache_free() 49 * that memory location is free to be reused at any time. Thus it may 50 * be possible to see another object there in the same RCU grace period. 51 * 52 * This feature only ensures the memory location backing the object 53 * stays valid, the trick to using this is relying on an independent 54 * object validation pass. Something like: 55 * 56 * rcu_read_lock() 57 * again: 58 * obj = lockless_lookup(key); 59 * if (obj) { 60 * if (!try_get_ref(obj)) // might fail for free objects 61 * goto again; 62 * 63 * if (obj->key != key) { // not the object we expected 64 * put_ref(obj); 65 * goto again; 66 * } 67 * } 68 * rcu_read_unlock(); 69 * 70 * This is useful if we need to approach a kernel structure obliquely, 71 * from its address obtained without the usual locking. We can lock 72 * the structure to stabilize it and check it's still at the given address, 73 * only if we can be sure that the memory has not been meanwhile reused 74 * for some other kind of object (which our subsystem's lock might corrupt). 75 * 76 * rcu_read_lock before reading the address, then rcu_read_unlock after 77 * taking the spinlock within the structure expected at that address. 78 * 79 * Note that it is not possible to acquire a lock within a structure 80 * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference 81 * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages 82 * are not zeroed before being given to the slab, which means that any 83 * locks must be initialized after each and every kmem_struct_alloc(). 84 * Alternatively, make the ctor passed to kmem_cache_create() initialize 85 * the locks at page-allocation time, as is done in __i915_request_ctor(), 86 * sighand_ctor(), and anon_vma_ctor(). Such a ctor permits readers 87 * to safely acquire those ctor-initialized locks under rcu_read_lock() 88 * protection. 89 * 90 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. 91 */ 92 /* Defer freeing slabs to RCU */ 93 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U) 94 /* Spread some memory over cpuset */ 95 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U) 96 /* Trace allocations and frees */ 97 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U) 98 99 /* Flag to prevent checks on free */ 100 #ifdef CONFIG_DEBUG_OBJECTS 101 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U) 102 #else 103 # define SLAB_DEBUG_OBJECTS 0 104 #endif 105 106 /* Avoid kmemleak tracing */ 107 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U) 108 109 /* Fault injection mark */ 110 #ifdef CONFIG_FAILSLAB 111 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U) 112 #else 113 # define SLAB_FAILSLAB 0 114 #endif 115 /* Account to memcg */ 116 #ifdef CONFIG_MEMCG_KMEM 117 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U) 118 #else 119 # define SLAB_ACCOUNT 0 120 #endif 121 122 #ifdef CONFIG_KASAN_GENERIC 123 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U) 124 #else 125 #define SLAB_KASAN 0 126 #endif 127 128 /* 129 * Ignore user specified debugging flags. 130 * Intended for caches created for self-tests so they have only flags 131 * specified in the code and other flags are ignored. 132 */ 133 #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U) 134 135 #ifdef CONFIG_KFENCE 136 #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U) 137 #else 138 #define SLAB_SKIP_KFENCE 0 139 #endif 140 141 /* The following flags affect the page allocator grouping pages by mobility */ 142 /* Objects are reclaimable */ 143 #ifndef CONFIG_SLUB_TINY 144 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) 145 #else 146 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0) 147 #endif 148 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 149 150 /* 151 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 152 * 153 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 154 * 155 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 156 * Both make kfree a no-op. 157 */ 158 #define ZERO_SIZE_PTR ((void *)16) 159 160 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 161 (unsigned long)ZERO_SIZE_PTR) 162 163 #include <linux/kasan.h> 164 165 struct list_lru; 166 struct mem_cgroup; 167 /* 168 * struct kmem_cache related prototypes 169 */ 170 bool slab_is_available(void); 171 172 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 173 unsigned int align, slab_flags_t flags, 174 void (*ctor)(void *)); 175 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 176 unsigned int size, unsigned int align, 177 slab_flags_t flags, 178 unsigned int useroffset, unsigned int usersize, 179 void (*ctor)(void *)); 180 void kmem_cache_destroy(struct kmem_cache *s); 181 int kmem_cache_shrink(struct kmem_cache *s); 182 183 /* 184 * Please use this macro to create slab caches. Simply specify the 185 * name of the structure and maybe some flags that are listed above. 186 * 187 * The alignment of the struct determines object alignment. If you 188 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 189 * then the objects will be properly aligned in SMP configurations. 190 */ 191 #define KMEM_CACHE(__struct, __flags) \ 192 kmem_cache_create(#__struct, sizeof(struct __struct), \ 193 __alignof__(struct __struct), (__flags), NULL) 194 195 /* 196 * To whitelist a single field for copying to/from usercopy, use this 197 * macro instead for KMEM_CACHE() above. 198 */ 199 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 200 kmem_cache_create_usercopy(#__struct, \ 201 sizeof(struct __struct), \ 202 __alignof__(struct __struct), (__flags), \ 203 offsetof(struct __struct, __field), \ 204 sizeof_field(struct __struct, __field), NULL) 205 206 /* 207 * Common kmalloc functions provided by all allocators 208 */ 209 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2); 210 void kfree(const void *objp); 211 void kfree_sensitive(const void *objp); 212 size_t __ksize(const void *objp); 213 214 /** 215 * ksize - Report actual allocation size of associated object 216 * 217 * @objp: Pointer returned from a prior kmalloc()-family allocation. 218 * 219 * This should not be used for writing beyond the originally requested 220 * allocation size. Either use krealloc() or round up the allocation size 221 * with kmalloc_size_roundup() prior to allocation. If this is used to 222 * access beyond the originally requested allocation size, UBSAN_BOUNDS 223 * and/or FORTIFY_SOURCE may trip, since they only know about the 224 * originally allocated size via the __alloc_size attribute. 225 */ 226 size_t ksize(const void *objp); 227 228 #ifdef CONFIG_PRINTK 229 bool kmem_valid_obj(void *object); 230 void kmem_dump_obj(void *object); 231 #endif 232 233 /* 234 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 235 * alignment larger than the alignment of a 64-bit integer. 236 * Setting ARCH_DMA_MINALIGN in arch headers allows that. 237 */ 238 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 239 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 240 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 241 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 242 #else 243 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 244 #endif 245 246 /* 247 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 248 * Intended for arches that get misalignment faults even for 64 bit integer 249 * aligned buffers. 250 */ 251 #ifndef ARCH_SLAB_MINALIGN 252 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 253 #endif 254 255 /* 256 * Arches can define this function if they want to decide the minimum slab 257 * alignment at runtime. The value returned by the function must be a power 258 * of two and >= ARCH_SLAB_MINALIGN. 259 */ 260 #ifndef arch_slab_minalign 261 static inline unsigned int arch_slab_minalign(void) 262 { 263 return ARCH_SLAB_MINALIGN; 264 } 265 #endif 266 267 /* 268 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN. 269 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN 270 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment. 271 */ 272 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 273 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 274 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 275 276 /* 277 * Kmalloc array related definitions 278 */ 279 280 #ifdef CONFIG_SLAB 281 /* 282 * SLAB and SLUB directly allocates requests fitting in to an order-1 page 283 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 284 */ 285 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 286 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT) 287 #ifndef KMALLOC_SHIFT_LOW 288 #define KMALLOC_SHIFT_LOW 5 289 #endif 290 #endif 291 292 #ifdef CONFIG_SLUB 293 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 294 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT) 295 #ifndef KMALLOC_SHIFT_LOW 296 #define KMALLOC_SHIFT_LOW 3 297 #endif 298 #endif 299 300 /* Maximum allocatable size */ 301 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 302 /* Maximum size for which we actually use a slab cache */ 303 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 304 /* Maximum order allocatable via the slab allocator */ 305 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 306 307 /* 308 * Kmalloc subsystem. 309 */ 310 #ifndef KMALLOC_MIN_SIZE 311 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 312 #endif 313 314 /* 315 * This restriction comes from byte sized index implementation. 316 * Page size is normally 2^12 bytes and, in this case, if we want to use 317 * byte sized index which can represent 2^8 entries, the size of the object 318 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 319 * If minimum size of kmalloc is less than 16, we use it as minimum object 320 * size and give up to use byte sized index. 321 */ 322 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 323 (KMALLOC_MIN_SIZE) : 16) 324 325 /* 326 * Whenever changing this, take care of that kmalloc_type() and 327 * create_kmalloc_caches() still work as intended. 328 * 329 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 330 * is for accounted but unreclaimable and non-dma objects. All the other 331 * kmem caches can have both accounted and unaccounted objects. 332 */ 333 enum kmalloc_cache_type { 334 KMALLOC_NORMAL = 0, 335 #ifndef CONFIG_ZONE_DMA 336 KMALLOC_DMA = KMALLOC_NORMAL, 337 #endif 338 #ifndef CONFIG_MEMCG_KMEM 339 KMALLOC_CGROUP = KMALLOC_NORMAL, 340 #endif 341 #ifdef CONFIG_SLUB_TINY 342 KMALLOC_RECLAIM = KMALLOC_NORMAL, 343 #else 344 KMALLOC_RECLAIM, 345 #endif 346 #ifdef CONFIG_ZONE_DMA 347 KMALLOC_DMA, 348 #endif 349 #ifdef CONFIG_MEMCG_KMEM 350 KMALLOC_CGROUP, 351 #endif 352 NR_KMALLOC_TYPES 353 }; 354 355 extern struct kmem_cache * 356 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 357 358 /* 359 * Define gfp bits that should not be set for KMALLOC_NORMAL. 360 */ 361 #define KMALLOC_NOT_NORMAL_BITS \ 362 (__GFP_RECLAIMABLE | \ 363 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 364 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 365 366 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 367 { 368 /* 369 * The most common case is KMALLOC_NORMAL, so test for it 370 * with a single branch for all the relevant flags. 371 */ 372 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 373 return KMALLOC_NORMAL; 374 375 /* 376 * At least one of the flags has to be set. Their priorities in 377 * decreasing order are: 378 * 1) __GFP_DMA 379 * 2) __GFP_RECLAIMABLE 380 * 3) __GFP_ACCOUNT 381 */ 382 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 383 return KMALLOC_DMA; 384 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 385 return KMALLOC_RECLAIM; 386 else 387 return KMALLOC_CGROUP; 388 } 389 390 /* 391 * Figure out which kmalloc slab an allocation of a certain size 392 * belongs to. 393 * 0 = zero alloc 394 * 1 = 65 .. 96 bytes 395 * 2 = 129 .. 192 bytes 396 * n = 2^(n-1)+1 .. 2^n 397 * 398 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 399 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 400 * Callers where !size_is_constant should only be test modules, where runtime 401 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 402 */ 403 static __always_inline unsigned int __kmalloc_index(size_t size, 404 bool size_is_constant) 405 { 406 if (!size) 407 return 0; 408 409 if (size <= KMALLOC_MIN_SIZE) 410 return KMALLOC_SHIFT_LOW; 411 412 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 413 return 1; 414 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 415 return 2; 416 if (size <= 8) return 3; 417 if (size <= 16) return 4; 418 if (size <= 32) return 5; 419 if (size <= 64) return 6; 420 if (size <= 128) return 7; 421 if (size <= 256) return 8; 422 if (size <= 512) return 9; 423 if (size <= 1024) return 10; 424 if (size <= 2 * 1024) return 11; 425 if (size <= 4 * 1024) return 12; 426 if (size <= 8 * 1024) return 13; 427 if (size <= 16 * 1024) return 14; 428 if (size <= 32 * 1024) return 15; 429 if (size <= 64 * 1024) return 16; 430 if (size <= 128 * 1024) return 17; 431 if (size <= 256 * 1024) return 18; 432 if (size <= 512 * 1024) return 19; 433 if (size <= 1024 * 1024) return 20; 434 if (size <= 2 * 1024 * 1024) return 21; 435 436 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 437 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 438 else 439 BUG(); 440 441 /* Will never be reached. Needed because the compiler may complain */ 442 return -1; 443 } 444 static_assert(PAGE_SHIFT <= 20); 445 #define kmalloc_index(s) __kmalloc_index(s, true) 446 447 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 448 449 /** 450 * kmem_cache_alloc - Allocate an object 451 * @cachep: The cache to allocate from. 452 * @flags: See kmalloc(). 453 * 454 * Allocate an object from this cache. 455 * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags. 456 * 457 * Return: pointer to the new object or %NULL in case of error 458 */ 459 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) __assume_slab_alignment __malloc; 460 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, 461 gfp_t gfpflags) __assume_slab_alignment __malloc; 462 void kmem_cache_free(struct kmem_cache *s, void *objp); 463 464 /* 465 * Bulk allocation and freeing operations. These are accelerated in an 466 * allocator specific way to avoid taking locks repeatedly or building 467 * metadata structures unnecessarily. 468 * 469 * Note that interrupts must be enabled when calling these functions. 470 */ 471 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 472 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 473 474 static __always_inline void kfree_bulk(size_t size, void **p) 475 { 476 kmem_cache_free_bulk(NULL, size, p); 477 } 478 479 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 480 __alloc_size(1); 481 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 482 __malloc; 483 484 void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 485 __assume_kmalloc_alignment __alloc_size(3); 486 487 void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 488 int node, size_t size) __assume_kmalloc_alignment 489 __alloc_size(4); 490 void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment 491 __alloc_size(1); 492 493 void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment 494 __alloc_size(1); 495 496 /** 497 * kmalloc - allocate kernel memory 498 * @size: how many bytes of memory are required. 499 * @flags: describe the allocation context 500 * 501 * kmalloc is the normal method of allocating memory 502 * for objects smaller than page size in the kernel. 503 * 504 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 505 * bytes. For @size of power of two bytes, the alignment is also guaranteed 506 * to be at least to the size. 507 * 508 * The @flags argument may be one of the GFP flags defined at 509 * include/linux/gfp_types.h and described at 510 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 511 * 512 * The recommended usage of the @flags is described at 513 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 514 * 515 * Below is a brief outline of the most useful GFP flags 516 * 517 * %GFP_KERNEL 518 * Allocate normal kernel ram. May sleep. 519 * 520 * %GFP_NOWAIT 521 * Allocation will not sleep. 522 * 523 * %GFP_ATOMIC 524 * Allocation will not sleep. May use emergency pools. 525 * 526 * Also it is possible to set different flags by OR'ing 527 * in one or more of the following additional @flags: 528 * 529 * %__GFP_ZERO 530 * Zero the allocated memory before returning. Also see kzalloc(). 531 * 532 * %__GFP_HIGH 533 * This allocation has high priority and may use emergency pools. 534 * 535 * %__GFP_NOFAIL 536 * Indicate that this allocation is in no way allowed to fail 537 * (think twice before using). 538 * 539 * %__GFP_NORETRY 540 * If memory is not immediately available, 541 * then give up at once. 542 * 543 * %__GFP_NOWARN 544 * If allocation fails, don't issue any warnings. 545 * 546 * %__GFP_RETRY_MAYFAIL 547 * Try really hard to succeed the allocation but fail 548 * eventually. 549 */ 550 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 551 { 552 if (__builtin_constant_p(size) && size) { 553 unsigned int index; 554 555 if (size > KMALLOC_MAX_CACHE_SIZE) 556 return kmalloc_large(size, flags); 557 558 index = kmalloc_index(size); 559 return kmalloc_trace( 560 kmalloc_caches[kmalloc_type(flags)][index], 561 flags, size); 562 } 563 return __kmalloc(size, flags); 564 } 565 566 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 567 { 568 if (__builtin_constant_p(size) && size) { 569 unsigned int index; 570 571 if (size > KMALLOC_MAX_CACHE_SIZE) 572 return kmalloc_large_node(size, flags, node); 573 574 index = kmalloc_index(size); 575 return kmalloc_node_trace( 576 kmalloc_caches[kmalloc_type(flags)][index], 577 flags, node, size); 578 } 579 return __kmalloc_node(size, flags, node); 580 } 581 582 /** 583 * kmalloc_array - allocate memory for an array. 584 * @n: number of elements. 585 * @size: element size. 586 * @flags: the type of memory to allocate (see kmalloc). 587 */ 588 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) 589 { 590 size_t bytes; 591 592 if (unlikely(check_mul_overflow(n, size, &bytes))) 593 return NULL; 594 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 595 return kmalloc(bytes, flags); 596 return __kmalloc(bytes, flags); 597 } 598 599 /** 600 * krealloc_array - reallocate memory for an array. 601 * @p: pointer to the memory chunk to reallocate 602 * @new_n: new number of elements to alloc 603 * @new_size: new size of a single member of the array 604 * @flags: the type of memory to allocate (see kmalloc) 605 */ 606 static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p, 607 size_t new_n, 608 size_t new_size, 609 gfp_t flags) 610 { 611 size_t bytes; 612 613 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 614 return NULL; 615 616 return krealloc(p, bytes, flags); 617 } 618 619 /** 620 * kcalloc - allocate memory for an array. The memory is set to zero. 621 * @n: number of elements. 622 * @size: element size. 623 * @flags: the type of memory to allocate (see kmalloc). 624 */ 625 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 626 { 627 return kmalloc_array(n, size, flags | __GFP_ZERO); 628 } 629 630 void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 631 unsigned long caller) __alloc_size(1); 632 #define kmalloc_node_track_caller(size, flags, node) \ 633 __kmalloc_node_track_caller(size, flags, node, \ 634 _RET_IP_) 635 636 /* 637 * kmalloc_track_caller is a special version of kmalloc that records the 638 * calling function of the routine calling it for slab leak tracking instead 639 * of just the calling function (confusing, eh?). 640 * It's useful when the call to kmalloc comes from a widely-used standard 641 * allocator where we care about the real place the memory allocation 642 * request comes from. 643 */ 644 #define kmalloc_track_caller(size, flags) \ 645 __kmalloc_node_track_caller(size, flags, \ 646 NUMA_NO_NODE, _RET_IP_) 647 648 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 649 int node) 650 { 651 size_t bytes; 652 653 if (unlikely(check_mul_overflow(n, size, &bytes))) 654 return NULL; 655 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 656 return kmalloc_node(bytes, flags, node); 657 return __kmalloc_node(bytes, flags, node); 658 } 659 660 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 661 { 662 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 663 } 664 665 /* 666 * Shortcuts 667 */ 668 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 669 { 670 return kmem_cache_alloc(k, flags | __GFP_ZERO); 671 } 672 673 /** 674 * kzalloc - allocate memory. The memory is set to zero. 675 * @size: how many bytes of memory are required. 676 * @flags: the type of memory to allocate (see kmalloc). 677 */ 678 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 679 { 680 return kmalloc(size, flags | __GFP_ZERO); 681 } 682 683 /** 684 * kzalloc_node - allocate zeroed memory from a particular memory node. 685 * @size: how many bytes of memory are required. 686 * @flags: the type of memory to allocate (see kmalloc). 687 * @node: memory node from which to allocate 688 */ 689 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 690 { 691 return kmalloc_node(size, flags | __GFP_ZERO, node); 692 } 693 694 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 695 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 696 { 697 return kvmalloc_node(size, flags, NUMA_NO_NODE); 698 } 699 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 700 { 701 return kvmalloc_node(size, flags | __GFP_ZERO, node); 702 } 703 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 704 { 705 return kvmalloc(size, flags | __GFP_ZERO); 706 } 707 708 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 709 { 710 size_t bytes; 711 712 if (unlikely(check_mul_overflow(n, size, &bytes))) 713 return NULL; 714 715 return kvmalloc(bytes, flags); 716 } 717 718 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 719 { 720 return kvmalloc_array(n, size, flags | __GFP_ZERO); 721 } 722 723 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 724 __realloc_size(3); 725 extern void kvfree(const void *addr); 726 extern void kvfree_sensitive(const void *addr, size_t len); 727 728 unsigned int kmem_cache_size(struct kmem_cache *s); 729 730 /** 731 * kmalloc_size_roundup - Report allocation bucket size for the given size 732 * 733 * @size: Number of bytes to round up from. 734 * 735 * This returns the number of bytes that would be available in a kmalloc() 736 * allocation of @size bytes. For example, a 126 byte request would be 737 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly 738 * for the general-purpose kmalloc()-based allocations, and is not for the 739 * pre-sized kmem_cache_alloc()-based allocations.) 740 * 741 * Use this to kmalloc() the full bucket size ahead of time instead of using 742 * ksize() to query the size after an allocation. 743 */ 744 size_t kmalloc_size_roundup(size_t size); 745 746 void __init kmem_cache_init_late(void); 747 748 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 749 int slab_prepare_cpu(unsigned int cpu); 750 int slab_dead_cpu(unsigned int cpu); 751 #else 752 #define slab_prepare_cpu NULL 753 #define slab_dead_cpu NULL 754 #endif 755 756 #endif /* _LINUX_SLAB_H */ 757