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/cache.h> 16 #include <linux/gfp.h> 17 #include <linux/overflow.h> 18 #include <linux/types.h> 19 #include <linux/workqueue.h> 20 #include <linux/percpu-refcount.h> 21 22 23 /* 24 * Flags to pass to kmem_cache_create(). 25 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set. 26 */ 27 /* DEBUG: Perform (expensive) checks on alloc/free */ 28 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U) 29 /* DEBUG: Red zone objs in a cache */ 30 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U) 31 /* DEBUG: Poison objects */ 32 #define SLAB_POISON ((slab_flags_t __force)0x00000800U) 33 /* Indicate a kmalloc slab */ 34 #define SLAB_KMALLOC ((slab_flags_t __force)0x00001000U) 35 /* Align objs on cache lines */ 36 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U) 37 /* Use GFP_DMA memory */ 38 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U) 39 /* Use GFP_DMA32 memory */ 40 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U) 41 /* DEBUG: Store the last owner for bug hunting */ 42 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U) 43 /* Panic if kmem_cache_create() fails */ 44 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U) 45 /* 46 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS! 47 * 48 * This delays freeing the SLAB page by a grace period, it does _NOT_ 49 * delay object freeing. This means that if you do kmem_cache_free() 50 * that memory location is free to be reused at any time. Thus it may 51 * be possible to see another object there in the same RCU grace period. 52 * 53 * This feature only ensures the memory location backing the object 54 * stays valid, the trick to using this is relying on an independent 55 * object validation pass. Something like: 56 * 57 * rcu_read_lock() 58 * again: 59 * obj = lockless_lookup(key); 60 * if (obj) { 61 * if (!try_get_ref(obj)) // might fail for free objects 62 * goto again; 63 * 64 * if (obj->key != key) { // not the object we expected 65 * put_ref(obj); 66 * goto again; 67 * } 68 * } 69 * rcu_read_unlock(); 70 * 71 * This is useful if we need to approach a kernel structure obliquely, 72 * from its address obtained without the usual locking. We can lock 73 * the structure to stabilize it and check it's still at the given address, 74 * only if we can be sure that the memory has not been meanwhile reused 75 * for some other kind of object (which our subsystem's lock might corrupt). 76 * 77 * rcu_read_lock before reading the address, then rcu_read_unlock after 78 * taking the spinlock within the structure expected at that address. 79 * 80 * Note that it is not possible to acquire a lock within a structure 81 * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference 82 * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages 83 * are not zeroed before being given to the slab, which means that any 84 * locks must be initialized after each and every kmem_struct_alloc(). 85 * Alternatively, make the ctor passed to kmem_cache_create() initialize 86 * the locks at page-allocation time, as is done in __i915_request_ctor(), 87 * sighand_ctor(), and anon_vma_ctor(). Such a ctor permits readers 88 * to safely acquire those ctor-initialized locks under rcu_read_lock() 89 * protection. 90 * 91 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. 92 */ 93 /* Defer freeing slabs to RCU */ 94 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U) 95 /* Spread some memory over cpuset */ 96 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U) 97 /* Trace allocations and frees */ 98 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U) 99 100 /* Flag to prevent checks on free */ 101 #ifdef CONFIG_DEBUG_OBJECTS 102 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U) 103 #else 104 # define SLAB_DEBUG_OBJECTS 0 105 #endif 106 107 /* Avoid kmemleak tracing */ 108 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U) 109 110 /* Fault injection mark */ 111 #ifdef CONFIG_FAILSLAB 112 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U) 113 #else 114 # define SLAB_FAILSLAB 0 115 #endif 116 /* Account to memcg */ 117 #ifdef CONFIG_MEMCG_KMEM 118 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U) 119 #else 120 # define SLAB_ACCOUNT 0 121 #endif 122 123 #ifdef CONFIG_KASAN_GENERIC 124 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U) 125 #else 126 #define SLAB_KASAN 0 127 #endif 128 129 /* 130 * Ignore user specified debugging flags. 131 * Intended for caches created for self-tests so they have only flags 132 * specified in the code and other flags are ignored. 133 */ 134 #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U) 135 136 #ifdef CONFIG_KFENCE 137 #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U) 138 #else 139 #define SLAB_SKIP_KFENCE 0 140 #endif 141 142 /* The following flags affect the page allocator grouping pages by mobility */ 143 /* Objects are reclaimable */ 144 #ifndef CONFIG_SLUB_TINY 145 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) 146 #else 147 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0) 148 #endif 149 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 150 151 /* 152 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 153 * 154 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 155 * 156 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 157 * Both make kfree a no-op. 158 */ 159 #define ZERO_SIZE_PTR ((void *)16) 160 161 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 162 (unsigned long)ZERO_SIZE_PTR) 163 164 #include <linux/kasan.h> 165 166 struct list_lru; 167 struct mem_cgroup; 168 /* 169 * struct kmem_cache related prototypes 170 */ 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 #ifdef ARCH_HAS_DMA_MINALIGN 240 #if ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN) 241 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 242 #endif 243 #endif 244 245 #ifndef ARCH_KMALLOC_MINALIGN 246 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 247 #elif ARCH_KMALLOC_MINALIGN > 8 248 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN 249 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) 250 #endif 251 252 /* 253 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 254 * Intended for arches that get misalignment faults even for 64 bit integer 255 * aligned buffers. 256 */ 257 #ifndef ARCH_SLAB_MINALIGN 258 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 259 #endif 260 261 /* 262 * Arches can define this function if they want to decide the minimum slab 263 * alignment at runtime. The value returned by the function must be a power 264 * of two and >= ARCH_SLAB_MINALIGN. 265 */ 266 #ifndef arch_slab_minalign 267 static inline unsigned int arch_slab_minalign(void) 268 { 269 return ARCH_SLAB_MINALIGN; 270 } 271 #endif 272 273 /* 274 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN. 275 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN 276 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment. 277 */ 278 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 279 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 280 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 281 282 /* 283 * Kmalloc array related definitions 284 */ 285 286 #ifdef CONFIG_SLAB 287 /* 288 * SLAB and SLUB directly allocates requests fitting in to an order-1 page 289 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 290 */ 291 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 292 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT) 293 #ifndef KMALLOC_SHIFT_LOW 294 #define KMALLOC_SHIFT_LOW 5 295 #endif 296 #endif 297 298 #ifdef CONFIG_SLUB 299 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 300 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT) 301 #ifndef KMALLOC_SHIFT_LOW 302 #define KMALLOC_SHIFT_LOW 3 303 #endif 304 #endif 305 306 /* Maximum allocatable size */ 307 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 308 /* Maximum size for which we actually use a slab cache */ 309 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 310 /* Maximum order allocatable via the slab allocator */ 311 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 312 313 /* 314 * Kmalloc subsystem. 315 */ 316 #ifndef KMALLOC_MIN_SIZE 317 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 318 #endif 319 320 /* 321 * This restriction comes from byte sized index implementation. 322 * Page size is normally 2^12 bytes and, in this case, if we want to use 323 * byte sized index which can represent 2^8 entries, the size of the object 324 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 325 * If minimum size of kmalloc is less than 16, we use it as minimum object 326 * size and give up to use byte sized index. 327 */ 328 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 329 (KMALLOC_MIN_SIZE) : 16) 330 331 /* 332 * Whenever changing this, take care of that kmalloc_type() and 333 * create_kmalloc_caches() still work as intended. 334 * 335 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 336 * is for accounted but unreclaimable and non-dma objects. All the other 337 * kmem caches can have both accounted and unaccounted objects. 338 */ 339 enum kmalloc_cache_type { 340 KMALLOC_NORMAL = 0, 341 #ifndef CONFIG_ZONE_DMA 342 KMALLOC_DMA = KMALLOC_NORMAL, 343 #endif 344 #ifndef CONFIG_MEMCG_KMEM 345 KMALLOC_CGROUP = KMALLOC_NORMAL, 346 #endif 347 #ifdef CONFIG_SLUB_TINY 348 KMALLOC_RECLAIM = KMALLOC_NORMAL, 349 #else 350 KMALLOC_RECLAIM, 351 #endif 352 #ifdef CONFIG_ZONE_DMA 353 KMALLOC_DMA, 354 #endif 355 #ifdef CONFIG_MEMCG_KMEM 356 KMALLOC_CGROUP, 357 #endif 358 NR_KMALLOC_TYPES 359 }; 360 361 extern struct kmem_cache * 362 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 363 364 /* 365 * Define gfp bits that should not be set for KMALLOC_NORMAL. 366 */ 367 #define KMALLOC_NOT_NORMAL_BITS \ 368 (__GFP_RECLAIMABLE | \ 369 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 370 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 371 372 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 373 { 374 /* 375 * The most common case is KMALLOC_NORMAL, so test for it 376 * with a single branch for all the relevant flags. 377 */ 378 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 379 return KMALLOC_NORMAL; 380 381 /* 382 * At least one of the flags has to be set. Their priorities in 383 * decreasing order are: 384 * 1) __GFP_DMA 385 * 2) __GFP_RECLAIMABLE 386 * 3) __GFP_ACCOUNT 387 */ 388 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 389 return KMALLOC_DMA; 390 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 391 return KMALLOC_RECLAIM; 392 else 393 return KMALLOC_CGROUP; 394 } 395 396 /* 397 * Figure out which kmalloc slab an allocation of a certain size 398 * belongs to. 399 * 0 = zero alloc 400 * 1 = 65 .. 96 bytes 401 * 2 = 129 .. 192 bytes 402 * n = 2^(n-1)+1 .. 2^n 403 * 404 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 405 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 406 * Callers where !size_is_constant should only be test modules, where runtime 407 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 408 */ 409 static __always_inline unsigned int __kmalloc_index(size_t size, 410 bool size_is_constant) 411 { 412 if (!size) 413 return 0; 414 415 if (size <= KMALLOC_MIN_SIZE) 416 return KMALLOC_SHIFT_LOW; 417 418 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 419 return 1; 420 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 421 return 2; 422 if (size <= 8) return 3; 423 if (size <= 16) return 4; 424 if (size <= 32) return 5; 425 if (size <= 64) return 6; 426 if (size <= 128) return 7; 427 if (size <= 256) return 8; 428 if (size <= 512) return 9; 429 if (size <= 1024) return 10; 430 if (size <= 2 * 1024) return 11; 431 if (size <= 4 * 1024) return 12; 432 if (size <= 8 * 1024) return 13; 433 if (size <= 16 * 1024) return 14; 434 if (size <= 32 * 1024) return 15; 435 if (size <= 64 * 1024) return 16; 436 if (size <= 128 * 1024) return 17; 437 if (size <= 256 * 1024) return 18; 438 if (size <= 512 * 1024) return 19; 439 if (size <= 1024 * 1024) return 20; 440 if (size <= 2 * 1024 * 1024) return 21; 441 442 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 443 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 444 else 445 BUG(); 446 447 /* Will never be reached. Needed because the compiler may complain */ 448 return -1; 449 } 450 static_assert(PAGE_SHIFT <= 20); 451 #define kmalloc_index(s) __kmalloc_index(s, true) 452 453 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 454 455 /** 456 * kmem_cache_alloc - Allocate an object 457 * @cachep: The cache to allocate from. 458 * @flags: See kmalloc(). 459 * 460 * Allocate an object from this cache. 461 * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags. 462 * 463 * Return: pointer to the new object or %NULL in case of error 464 */ 465 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) __assume_slab_alignment __malloc; 466 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, 467 gfp_t gfpflags) __assume_slab_alignment __malloc; 468 void kmem_cache_free(struct kmem_cache *s, void *objp); 469 470 /* 471 * Bulk allocation and freeing operations. These are accelerated in an 472 * allocator specific way to avoid taking locks repeatedly or building 473 * metadata structures unnecessarily. 474 * 475 * Note that interrupts must be enabled when calling these functions. 476 */ 477 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 478 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 479 480 static __always_inline void kfree_bulk(size_t size, void **p) 481 { 482 kmem_cache_free_bulk(NULL, size, p); 483 } 484 485 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 486 __alloc_size(1); 487 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 488 __malloc; 489 490 void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 491 __assume_kmalloc_alignment __alloc_size(3); 492 493 void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 494 int node, size_t size) __assume_kmalloc_alignment 495 __alloc_size(4); 496 void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment 497 __alloc_size(1); 498 499 void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment 500 __alloc_size(1); 501 502 /** 503 * kmalloc - allocate kernel memory 504 * @size: how many bytes of memory are required. 505 * @flags: describe the allocation context 506 * 507 * kmalloc is the normal method of allocating memory 508 * for objects smaller than page size in the kernel. 509 * 510 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 511 * bytes. For @size of power of two bytes, the alignment is also guaranteed 512 * to be at least to the size. 513 * 514 * The @flags argument may be one of the GFP flags defined at 515 * include/linux/gfp_types.h and described at 516 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 517 * 518 * The recommended usage of the @flags is described at 519 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 520 * 521 * Below is a brief outline of the most useful GFP flags 522 * 523 * %GFP_KERNEL 524 * Allocate normal kernel ram. May sleep. 525 * 526 * %GFP_NOWAIT 527 * Allocation will not sleep. 528 * 529 * %GFP_ATOMIC 530 * Allocation will not sleep. May use emergency pools. 531 * 532 * Also it is possible to set different flags by OR'ing 533 * in one or more of the following additional @flags: 534 * 535 * %__GFP_ZERO 536 * Zero the allocated memory before returning. Also see kzalloc(). 537 * 538 * %__GFP_HIGH 539 * This allocation has high priority and may use emergency pools. 540 * 541 * %__GFP_NOFAIL 542 * Indicate that this allocation is in no way allowed to fail 543 * (think twice before using). 544 * 545 * %__GFP_NORETRY 546 * If memory is not immediately available, 547 * then give up at once. 548 * 549 * %__GFP_NOWARN 550 * If allocation fails, don't issue any warnings. 551 * 552 * %__GFP_RETRY_MAYFAIL 553 * Try really hard to succeed the allocation but fail 554 * eventually. 555 */ 556 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 557 { 558 if (__builtin_constant_p(size) && size) { 559 unsigned int index; 560 561 if (size > KMALLOC_MAX_CACHE_SIZE) 562 return kmalloc_large(size, flags); 563 564 index = kmalloc_index(size); 565 return kmalloc_trace( 566 kmalloc_caches[kmalloc_type(flags)][index], 567 flags, size); 568 } 569 return __kmalloc(size, flags); 570 } 571 572 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 573 { 574 if (__builtin_constant_p(size) && size) { 575 unsigned int index; 576 577 if (size > KMALLOC_MAX_CACHE_SIZE) 578 return kmalloc_large_node(size, flags, node); 579 580 index = kmalloc_index(size); 581 return kmalloc_node_trace( 582 kmalloc_caches[kmalloc_type(flags)][index], 583 flags, node, size); 584 } 585 return __kmalloc_node(size, flags, node); 586 } 587 588 /** 589 * kmalloc_array - allocate memory for an array. 590 * @n: number of elements. 591 * @size: element size. 592 * @flags: the type of memory to allocate (see kmalloc). 593 */ 594 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) 595 { 596 size_t bytes; 597 598 if (unlikely(check_mul_overflow(n, size, &bytes))) 599 return NULL; 600 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 601 return kmalloc(bytes, flags); 602 return __kmalloc(bytes, flags); 603 } 604 605 /** 606 * krealloc_array - reallocate memory for an array. 607 * @p: pointer to the memory chunk to reallocate 608 * @new_n: new number of elements to alloc 609 * @new_size: new size of a single member of the array 610 * @flags: the type of memory to allocate (see kmalloc) 611 */ 612 static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p, 613 size_t new_n, 614 size_t new_size, 615 gfp_t flags) 616 { 617 size_t bytes; 618 619 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 620 return NULL; 621 622 return krealloc(p, bytes, flags); 623 } 624 625 /** 626 * kcalloc - allocate memory for an array. The memory is set to zero. 627 * @n: number of elements. 628 * @size: element size. 629 * @flags: the type of memory to allocate (see kmalloc). 630 */ 631 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 632 { 633 return kmalloc_array(n, size, flags | __GFP_ZERO); 634 } 635 636 void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 637 unsigned long caller) __alloc_size(1); 638 #define kmalloc_node_track_caller(size, flags, node) \ 639 __kmalloc_node_track_caller(size, flags, node, \ 640 _RET_IP_) 641 642 /* 643 * kmalloc_track_caller is a special version of kmalloc that records the 644 * calling function of the routine calling it for slab leak tracking instead 645 * of just the calling function (confusing, eh?). 646 * It's useful when the call to kmalloc comes from a widely-used standard 647 * allocator where we care about the real place the memory allocation 648 * request comes from. 649 */ 650 #define kmalloc_track_caller(size, flags) \ 651 __kmalloc_node_track_caller(size, flags, \ 652 NUMA_NO_NODE, _RET_IP_) 653 654 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 655 int node) 656 { 657 size_t bytes; 658 659 if (unlikely(check_mul_overflow(n, size, &bytes))) 660 return NULL; 661 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 662 return kmalloc_node(bytes, flags, node); 663 return __kmalloc_node(bytes, flags, node); 664 } 665 666 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 667 { 668 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 669 } 670 671 /* 672 * Shortcuts 673 */ 674 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 675 { 676 return kmem_cache_alloc(k, flags | __GFP_ZERO); 677 } 678 679 /** 680 * kzalloc - allocate memory. The memory is set to zero. 681 * @size: how many bytes of memory are required. 682 * @flags: the type of memory to allocate (see kmalloc). 683 */ 684 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 685 { 686 return kmalloc(size, flags | __GFP_ZERO); 687 } 688 689 /** 690 * kzalloc_node - allocate zeroed memory from a particular memory node. 691 * @size: how many bytes of memory are required. 692 * @flags: the type of memory to allocate (see kmalloc). 693 * @node: memory node from which to allocate 694 */ 695 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 696 { 697 return kmalloc_node(size, flags | __GFP_ZERO, node); 698 } 699 700 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 701 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 702 { 703 return kvmalloc_node(size, flags, NUMA_NO_NODE); 704 } 705 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 706 { 707 return kvmalloc_node(size, flags | __GFP_ZERO, node); 708 } 709 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 710 { 711 return kvmalloc(size, flags | __GFP_ZERO); 712 } 713 714 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 715 { 716 size_t bytes; 717 718 if (unlikely(check_mul_overflow(n, size, &bytes))) 719 return NULL; 720 721 return kvmalloc(bytes, flags); 722 } 723 724 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 725 { 726 return kvmalloc_array(n, size, flags | __GFP_ZERO); 727 } 728 729 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 730 __realloc_size(3); 731 extern void kvfree(const void *addr); 732 extern void kvfree_sensitive(const void *addr, size_t len); 733 734 unsigned int kmem_cache_size(struct kmem_cache *s); 735 736 /** 737 * kmalloc_size_roundup - Report allocation bucket size for the given size 738 * 739 * @size: Number of bytes to round up from. 740 * 741 * This returns the number of bytes that would be available in a kmalloc() 742 * allocation of @size bytes. For example, a 126 byte request would be 743 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly 744 * for the general-purpose kmalloc()-based allocations, and is not for the 745 * pre-sized kmem_cache_alloc()-based allocations.) 746 * 747 * Use this to kmalloc() the full bucket size ahead of time instead of using 748 * ksize() to query the size after an allocation. 749 */ 750 size_t kmalloc_size_roundup(size_t size); 751 752 void __init kmem_cache_init_late(void); 753 754 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 755 int slab_prepare_cpu(unsigned int cpu); 756 int slab_dead_cpu(unsigned int cpu); 757 #else 758 #define slab_prepare_cpu NULL 759 #define slab_dead_cpu NULL 760 #endif 761 762 #endif /* _LINUX_SLAB_H */ 763