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 void __init kmem_cache_init(void); 171 bool slab_is_available(void); 172 173 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 174 unsigned int align, slab_flags_t flags, 175 void (*ctor)(void *)); 176 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 177 unsigned int size, unsigned int align, 178 slab_flags_t flags, 179 unsigned int useroffset, unsigned int usersize, 180 void (*ctor)(void *)); 181 void kmem_cache_destroy(struct kmem_cache *s); 182 int kmem_cache_shrink(struct kmem_cache *s); 183 184 /* 185 * Please use this macro to create slab caches. Simply specify the 186 * name of the structure and maybe some flags that are listed above. 187 * 188 * The alignment of the struct determines object alignment. If you 189 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 190 * then the objects will be properly aligned in SMP configurations. 191 */ 192 #define KMEM_CACHE(__struct, __flags) \ 193 kmem_cache_create(#__struct, sizeof(struct __struct), \ 194 __alignof__(struct __struct), (__flags), NULL) 195 196 /* 197 * To whitelist a single field for copying to/from usercopy, use this 198 * macro instead for KMEM_CACHE() above. 199 */ 200 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 201 kmem_cache_create_usercopy(#__struct, \ 202 sizeof(struct __struct), \ 203 __alignof__(struct __struct), (__flags), \ 204 offsetof(struct __struct, __field), \ 205 sizeof_field(struct __struct, __field), NULL) 206 207 /* 208 * Common kmalloc functions provided by all allocators 209 */ 210 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2); 211 void kfree(const void *objp); 212 void kfree_sensitive(const void *objp); 213 size_t __ksize(const void *objp); 214 215 /** 216 * ksize - Report actual allocation size of associated object 217 * 218 * @objp: Pointer returned from a prior kmalloc()-family allocation. 219 * 220 * This should not be used for writing beyond the originally requested 221 * allocation size. Either use krealloc() or round up the allocation size 222 * with kmalloc_size_roundup() prior to allocation. If this is used to 223 * access beyond the originally requested allocation size, UBSAN_BOUNDS 224 * and/or FORTIFY_SOURCE may trip, since they only know about the 225 * originally allocated size via the __alloc_size attribute. 226 */ 227 size_t ksize(const void *objp); 228 229 #ifdef CONFIG_PRINTK 230 bool kmem_valid_obj(void *object); 231 void kmem_dump_obj(void *object); 232 #endif 233 234 /* 235 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 236 * alignment larger than the alignment of a 64-bit integer. 237 * Setting ARCH_DMA_MINALIGN in arch headers allows that. 238 */ 239 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 240 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 241 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 242 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 243 #else 244 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 245 #endif 246 247 /* 248 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 249 * Intended for arches that get misalignment faults even for 64 bit integer 250 * aligned buffers. 251 */ 252 #ifndef ARCH_SLAB_MINALIGN 253 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 254 #endif 255 256 /* 257 * Arches can define this function if they want to decide the minimum slab 258 * alignment at runtime. The value returned by the function must be a power 259 * of two and >= ARCH_SLAB_MINALIGN. 260 */ 261 #ifndef arch_slab_minalign 262 static inline unsigned int arch_slab_minalign(void) 263 { 264 return ARCH_SLAB_MINALIGN; 265 } 266 #endif 267 268 /* 269 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN. 270 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN 271 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment. 272 */ 273 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 274 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 275 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 276 277 /* 278 * Kmalloc array related definitions 279 */ 280 281 #ifdef CONFIG_SLAB 282 /* 283 * SLAB and SLUB directly allocates requests fitting in to an order-1 page 284 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 285 */ 286 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 287 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 288 #ifndef KMALLOC_SHIFT_LOW 289 #define KMALLOC_SHIFT_LOW 5 290 #endif 291 #endif 292 293 #ifdef CONFIG_SLUB 294 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 295 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 296 #ifndef KMALLOC_SHIFT_LOW 297 #define KMALLOC_SHIFT_LOW 3 298 #endif 299 #endif 300 301 /* Maximum allocatable size */ 302 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 303 /* Maximum size for which we actually use a slab cache */ 304 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 305 /* Maximum order allocatable via the slab allocator */ 306 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 307 308 /* 309 * Kmalloc subsystem. 310 */ 311 #ifndef KMALLOC_MIN_SIZE 312 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 313 #endif 314 315 /* 316 * This restriction comes from byte sized index implementation. 317 * Page size is normally 2^12 bytes and, in this case, if we want to use 318 * byte sized index which can represent 2^8 entries, the size of the object 319 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 320 * If minimum size of kmalloc is less than 16, we use it as minimum object 321 * size and give up to use byte sized index. 322 */ 323 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 324 (KMALLOC_MIN_SIZE) : 16) 325 326 /* 327 * Whenever changing this, take care of that kmalloc_type() and 328 * create_kmalloc_caches() still work as intended. 329 * 330 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 331 * is for accounted but unreclaimable and non-dma objects. All the other 332 * kmem caches can have both accounted and unaccounted objects. 333 */ 334 enum kmalloc_cache_type { 335 KMALLOC_NORMAL = 0, 336 #ifndef CONFIG_ZONE_DMA 337 KMALLOC_DMA = KMALLOC_NORMAL, 338 #endif 339 #ifndef CONFIG_MEMCG_KMEM 340 KMALLOC_CGROUP = KMALLOC_NORMAL, 341 #endif 342 #ifdef CONFIG_SLUB_TINY 343 KMALLOC_RECLAIM = KMALLOC_NORMAL, 344 #else 345 KMALLOC_RECLAIM, 346 #endif 347 #ifdef CONFIG_ZONE_DMA 348 KMALLOC_DMA, 349 #endif 350 #ifdef CONFIG_MEMCG_KMEM 351 KMALLOC_CGROUP, 352 #endif 353 NR_KMALLOC_TYPES 354 }; 355 356 extern struct kmem_cache * 357 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 358 359 /* 360 * Define gfp bits that should not be set for KMALLOC_NORMAL. 361 */ 362 #define KMALLOC_NOT_NORMAL_BITS \ 363 (__GFP_RECLAIMABLE | \ 364 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 365 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 366 367 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 368 { 369 /* 370 * The most common case is KMALLOC_NORMAL, so test for it 371 * with a single branch for all the relevant flags. 372 */ 373 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 374 return KMALLOC_NORMAL; 375 376 /* 377 * At least one of the flags has to be set. Their priorities in 378 * decreasing order are: 379 * 1) __GFP_DMA 380 * 2) __GFP_RECLAIMABLE 381 * 3) __GFP_ACCOUNT 382 */ 383 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 384 return KMALLOC_DMA; 385 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 386 return KMALLOC_RECLAIM; 387 else 388 return KMALLOC_CGROUP; 389 } 390 391 /* 392 * Figure out which kmalloc slab an allocation of a certain size 393 * belongs to. 394 * 0 = zero alloc 395 * 1 = 65 .. 96 bytes 396 * 2 = 129 .. 192 bytes 397 * n = 2^(n-1)+1 .. 2^n 398 * 399 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 400 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 401 * Callers where !size_is_constant should only be test modules, where runtime 402 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 403 */ 404 static __always_inline unsigned int __kmalloc_index(size_t size, 405 bool size_is_constant) 406 { 407 if (!size) 408 return 0; 409 410 if (size <= KMALLOC_MIN_SIZE) 411 return KMALLOC_SHIFT_LOW; 412 413 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 414 return 1; 415 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 416 return 2; 417 if (size <= 8) return 3; 418 if (size <= 16) return 4; 419 if (size <= 32) return 5; 420 if (size <= 64) return 6; 421 if (size <= 128) return 7; 422 if (size <= 256) return 8; 423 if (size <= 512) return 9; 424 if (size <= 1024) return 10; 425 if (size <= 2 * 1024) return 11; 426 if (size <= 4 * 1024) return 12; 427 if (size <= 8 * 1024) return 13; 428 if (size <= 16 * 1024) return 14; 429 if (size <= 32 * 1024) return 15; 430 if (size <= 64 * 1024) return 16; 431 if (size <= 128 * 1024) return 17; 432 if (size <= 256 * 1024) return 18; 433 if (size <= 512 * 1024) return 19; 434 if (size <= 1024 * 1024) return 20; 435 if (size <= 2 * 1024 * 1024) return 21; 436 437 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 438 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 439 else 440 BUG(); 441 442 /* Will never be reached. Needed because the compiler may complain */ 443 return -1; 444 } 445 static_assert(PAGE_SHIFT <= 20); 446 #define kmalloc_index(s) __kmalloc_index(s, true) 447 448 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 449 450 /** 451 * kmem_cache_alloc - Allocate an object 452 * @cachep: The cache to allocate from. 453 * @flags: See kmalloc(). 454 * 455 * Allocate an object from this cache. 456 * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags. 457 * 458 * Return: pointer to the new object or %NULL in case of error 459 */ 460 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) __assume_slab_alignment __malloc; 461 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, 462 gfp_t gfpflags) __assume_slab_alignment __malloc; 463 void kmem_cache_free(struct kmem_cache *s, void *objp); 464 465 /* 466 * Bulk allocation and freeing operations. These are accelerated in an 467 * allocator specific way to avoid taking locks repeatedly or building 468 * metadata structures unnecessarily. 469 * 470 * Note that interrupts must be enabled when calling these functions. 471 */ 472 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 473 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 474 475 static __always_inline void kfree_bulk(size_t size, void **p) 476 { 477 kmem_cache_free_bulk(NULL, size, p); 478 } 479 480 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 481 __alloc_size(1); 482 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 483 __malloc; 484 485 void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 486 __assume_kmalloc_alignment __alloc_size(3); 487 488 void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 489 int node, size_t size) __assume_kmalloc_alignment 490 __alloc_size(4); 491 void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment 492 __alloc_size(1); 493 494 void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment 495 __alloc_size(1); 496 497 /** 498 * kmalloc - allocate kernel memory 499 * @size: how many bytes of memory are required. 500 * @flags: describe the allocation context 501 * 502 * kmalloc is the normal method of allocating memory 503 * for objects smaller than page size in the kernel. 504 * 505 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 506 * bytes. For @size of power of two bytes, the alignment is also guaranteed 507 * to be at least to the size. 508 * 509 * The @flags argument may be one of the GFP flags defined at 510 * include/linux/gfp_types.h and described at 511 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 512 * 513 * The recommended usage of the @flags is described at 514 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 515 * 516 * Below is a brief outline of the most useful GFP flags 517 * 518 * %GFP_KERNEL 519 * Allocate normal kernel ram. May sleep. 520 * 521 * %GFP_NOWAIT 522 * Allocation will not sleep. 523 * 524 * %GFP_ATOMIC 525 * Allocation will not sleep. May use emergency pools. 526 * 527 * Also it is possible to set different flags by OR'ing 528 * in one or more of the following additional @flags: 529 * 530 * %__GFP_ZERO 531 * Zero the allocated memory before returning. Also see kzalloc(). 532 * 533 * %__GFP_HIGH 534 * This allocation has high priority and may use emergency pools. 535 * 536 * %__GFP_NOFAIL 537 * Indicate that this allocation is in no way allowed to fail 538 * (think twice before using). 539 * 540 * %__GFP_NORETRY 541 * If memory is not immediately available, 542 * then give up at once. 543 * 544 * %__GFP_NOWARN 545 * If allocation fails, don't issue any warnings. 546 * 547 * %__GFP_RETRY_MAYFAIL 548 * Try really hard to succeed the allocation but fail 549 * eventually. 550 */ 551 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 552 { 553 if (__builtin_constant_p(size) && size) { 554 unsigned int index; 555 556 if (size > KMALLOC_MAX_CACHE_SIZE) 557 return kmalloc_large(size, flags); 558 559 index = kmalloc_index(size); 560 return kmalloc_trace( 561 kmalloc_caches[kmalloc_type(flags)][index], 562 flags, size); 563 } 564 return __kmalloc(size, flags); 565 } 566 567 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 568 { 569 if (__builtin_constant_p(size) && size) { 570 unsigned int index; 571 572 if (size > KMALLOC_MAX_CACHE_SIZE) 573 return kmalloc_large_node(size, flags, node); 574 575 index = kmalloc_index(size); 576 return kmalloc_node_trace( 577 kmalloc_caches[kmalloc_type(flags)][index], 578 flags, node, size); 579 } 580 return __kmalloc_node(size, flags, node); 581 } 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 __alloc_size(1, 2) 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 * krealloc_array - reallocate memory for an array. 602 * @p: pointer to the memory chunk to reallocate 603 * @new_n: new number of elements to alloc 604 * @new_size: new size of a single member of the array 605 * @flags: the type of memory to allocate (see kmalloc) 606 */ 607 static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p, 608 size_t new_n, 609 size_t new_size, 610 gfp_t flags) 611 { 612 size_t bytes; 613 614 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 615 return NULL; 616 617 return krealloc(p, bytes, flags); 618 } 619 620 /** 621 * kcalloc - allocate memory for an array. The memory is set to zero. 622 * @n: number of elements. 623 * @size: element size. 624 * @flags: the type of memory to allocate (see kmalloc). 625 */ 626 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 627 { 628 return kmalloc_array(n, size, flags | __GFP_ZERO); 629 } 630 631 void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 632 unsigned long caller) __alloc_size(1); 633 #define kmalloc_node_track_caller(size, flags, node) \ 634 __kmalloc_node_track_caller(size, flags, node, \ 635 _RET_IP_) 636 637 /* 638 * kmalloc_track_caller is a special version of kmalloc that records the 639 * calling function of the routine calling it for slab leak tracking instead 640 * of just the calling function (confusing, eh?). 641 * It's useful when the call to kmalloc comes from a widely-used standard 642 * allocator where we care about the real place the memory allocation 643 * request comes from. 644 */ 645 #define kmalloc_track_caller(size, flags) \ 646 __kmalloc_node_track_caller(size, flags, \ 647 NUMA_NO_NODE, _RET_IP_) 648 649 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 650 int node) 651 { 652 size_t bytes; 653 654 if (unlikely(check_mul_overflow(n, size, &bytes))) 655 return NULL; 656 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 657 return kmalloc_node(bytes, flags, node); 658 return __kmalloc_node(bytes, flags, node); 659 } 660 661 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 662 { 663 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 664 } 665 666 /* 667 * Shortcuts 668 */ 669 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 670 { 671 return kmem_cache_alloc(k, flags | __GFP_ZERO); 672 } 673 674 /** 675 * kzalloc - allocate memory. The memory is set to zero. 676 * @size: how many bytes of memory are required. 677 * @flags: the type of memory to allocate (see kmalloc). 678 */ 679 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 680 { 681 return kmalloc(size, flags | __GFP_ZERO); 682 } 683 684 /** 685 * kzalloc_node - allocate zeroed memory from a particular memory node. 686 * @size: how many bytes of memory are required. 687 * @flags: the type of memory to allocate (see kmalloc). 688 * @node: memory node from which to allocate 689 */ 690 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 691 { 692 return kmalloc_node(size, flags | __GFP_ZERO, node); 693 } 694 695 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 696 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 697 { 698 return kvmalloc_node(size, flags, NUMA_NO_NODE); 699 } 700 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 701 { 702 return kvmalloc_node(size, flags | __GFP_ZERO, node); 703 } 704 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 705 { 706 return kvmalloc(size, flags | __GFP_ZERO); 707 } 708 709 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 710 { 711 size_t bytes; 712 713 if (unlikely(check_mul_overflow(n, size, &bytes))) 714 return NULL; 715 716 return kvmalloc(bytes, flags); 717 } 718 719 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 720 { 721 return kvmalloc_array(n, size, flags | __GFP_ZERO); 722 } 723 724 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 725 __realloc_size(3); 726 extern void kvfree(const void *addr); 727 extern void kvfree_sensitive(const void *addr, size_t len); 728 729 unsigned int kmem_cache_size(struct kmem_cache *s); 730 731 /** 732 * kmalloc_size_roundup - Report allocation bucket size for the given size 733 * 734 * @size: Number of bytes to round up from. 735 * 736 * This returns the number of bytes that would be available in a kmalloc() 737 * allocation of @size bytes. For example, a 126 byte request would be 738 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly 739 * for the general-purpose kmalloc()-based allocations, and is not for the 740 * pre-sized kmem_cache_alloc()-based allocations.) 741 * 742 * Use this to kmalloc() the full bucket size ahead of time instead of using 743 * ksize() to query the size after an allocation. 744 */ 745 size_t kmalloc_size_roundup(size_t size); 746 747 void __init kmem_cache_init_late(void); 748 749 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 750 int slab_prepare_cpu(unsigned int cpu); 751 int slab_dead_cpu(unsigned int cpu); 752 #else 753 #define slab_prepare_cpu NULL 754 #define slab_dead_cpu NULL 755 #endif 756 757 #endif /* _LINUX_SLAB_H */ 758