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 /* 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 /* 116 * Ignore user specified debugging flags. 117 * Intended for caches created for self-tests so they have only flags 118 * specified in the code and other flags are ignored. 119 */ 120 #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U) 121 122 /* The following flags affect the page allocator grouping pages by mobility */ 123 /* Objects are reclaimable */ 124 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) 125 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 126 127 /* 128 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 129 * 130 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 131 * 132 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 133 * Both make kfree a no-op. 134 */ 135 #define ZERO_SIZE_PTR ((void *)16) 136 137 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 138 (unsigned long)ZERO_SIZE_PTR) 139 140 #include <linux/kasan.h> 141 142 struct list_lru; 143 struct mem_cgroup; 144 /* 145 * struct kmem_cache related prototypes 146 */ 147 void __init kmem_cache_init(void); 148 bool slab_is_available(void); 149 150 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 151 unsigned int align, slab_flags_t flags, 152 void (*ctor)(void *)); 153 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 154 unsigned int size, unsigned int align, 155 slab_flags_t flags, 156 unsigned int useroffset, unsigned int usersize, 157 void (*ctor)(void *)); 158 void kmem_cache_destroy(struct kmem_cache *s); 159 int kmem_cache_shrink(struct kmem_cache *s); 160 161 /* 162 * Please use this macro to create slab caches. Simply specify the 163 * name of the structure and maybe some flags that are listed above. 164 * 165 * The alignment of the struct determines object alignment. If you 166 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 167 * then the objects will be properly aligned in SMP configurations. 168 */ 169 #define KMEM_CACHE(__struct, __flags) \ 170 kmem_cache_create(#__struct, sizeof(struct __struct), \ 171 __alignof__(struct __struct), (__flags), NULL) 172 173 /* 174 * To whitelist a single field for copying to/from usercopy, use this 175 * macro instead for KMEM_CACHE() above. 176 */ 177 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 178 kmem_cache_create_usercopy(#__struct, \ 179 sizeof(struct __struct), \ 180 __alignof__(struct __struct), (__flags), \ 181 offsetof(struct __struct, __field), \ 182 sizeof_field(struct __struct, __field), NULL) 183 184 /* 185 * Common kmalloc functions provided by all allocators 186 */ 187 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __alloc_size(2); 188 void kfree(const void *objp); 189 void kfree_sensitive(const void *objp); 190 size_t __ksize(const void *objp); 191 size_t ksize(const void *objp); 192 #ifdef CONFIG_PRINTK 193 bool kmem_valid_obj(void *object); 194 void kmem_dump_obj(void *object); 195 #endif 196 197 /* 198 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 199 * alignment larger than the alignment of a 64-bit integer. 200 * Setting ARCH_DMA_MINALIGN in arch headers allows that. 201 */ 202 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 203 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 204 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 205 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 206 #else 207 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 208 #endif 209 210 /* 211 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 212 * Intended for arches that get misalignment faults even for 64 bit integer 213 * aligned buffers. 214 */ 215 #ifndef ARCH_SLAB_MINALIGN 216 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 217 #endif 218 219 /* 220 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN. 221 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN 222 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment. 223 */ 224 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 225 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 226 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 227 228 /* 229 * Kmalloc array related definitions 230 */ 231 232 #ifdef CONFIG_SLAB 233 /* 234 * The largest kmalloc size supported by the SLAB allocators is 235 * 32 megabyte (2^25) or the maximum allocatable page order if that is 236 * less than 32 MB. 237 * 238 * WARNING: Its not easy to increase this value since the allocators have 239 * to do various tricks to work around compiler limitations in order to 240 * ensure proper constant folding. 241 */ 242 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 243 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 244 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 245 #ifndef KMALLOC_SHIFT_LOW 246 #define KMALLOC_SHIFT_LOW 5 247 #endif 248 #endif 249 250 #ifdef CONFIG_SLUB 251 /* 252 * SLUB directly allocates requests fitting in to an order-1 page 253 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 254 */ 255 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 256 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 257 #ifndef KMALLOC_SHIFT_LOW 258 #define KMALLOC_SHIFT_LOW 3 259 #endif 260 #endif 261 262 #ifdef CONFIG_SLOB 263 /* 264 * SLOB passes all requests larger than one page to the page allocator. 265 * No kmalloc array is necessary since objects of different sizes can 266 * be allocated from the same page. 267 */ 268 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 269 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 270 #ifndef KMALLOC_SHIFT_LOW 271 #define KMALLOC_SHIFT_LOW 3 272 #endif 273 #endif 274 275 /* Maximum allocatable size */ 276 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 277 /* Maximum size for which we actually use a slab cache */ 278 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 279 /* Maximum order allocatable via the slab allocator */ 280 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 281 282 /* 283 * Kmalloc subsystem. 284 */ 285 #ifndef KMALLOC_MIN_SIZE 286 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 287 #endif 288 289 /* 290 * This restriction comes from byte sized index implementation. 291 * Page size is normally 2^12 bytes and, in this case, if we want to use 292 * byte sized index which can represent 2^8 entries, the size of the object 293 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 294 * If minimum size of kmalloc is less than 16, we use it as minimum object 295 * size and give up to use byte sized index. 296 */ 297 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 298 (KMALLOC_MIN_SIZE) : 16) 299 300 /* 301 * Whenever changing this, take care of that kmalloc_type() and 302 * create_kmalloc_caches() still work as intended. 303 * 304 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 305 * is for accounted but unreclaimable and non-dma objects. All the other 306 * kmem caches can have both accounted and unaccounted objects. 307 */ 308 enum kmalloc_cache_type { 309 KMALLOC_NORMAL = 0, 310 #ifndef CONFIG_ZONE_DMA 311 KMALLOC_DMA = KMALLOC_NORMAL, 312 #endif 313 #ifndef CONFIG_MEMCG_KMEM 314 KMALLOC_CGROUP = KMALLOC_NORMAL, 315 #else 316 KMALLOC_CGROUP, 317 #endif 318 KMALLOC_RECLAIM, 319 #ifdef CONFIG_ZONE_DMA 320 KMALLOC_DMA, 321 #endif 322 NR_KMALLOC_TYPES 323 }; 324 325 #ifndef CONFIG_SLOB 326 extern struct kmem_cache * 327 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 328 329 /* 330 * Define gfp bits that should not be set for KMALLOC_NORMAL. 331 */ 332 #define KMALLOC_NOT_NORMAL_BITS \ 333 (__GFP_RECLAIMABLE | \ 334 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 335 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 336 337 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 338 { 339 /* 340 * The most common case is KMALLOC_NORMAL, so test for it 341 * with a single branch for all the relevant flags. 342 */ 343 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 344 return KMALLOC_NORMAL; 345 346 /* 347 * At least one of the flags has to be set. Their priorities in 348 * decreasing order are: 349 * 1) __GFP_DMA 350 * 2) __GFP_RECLAIMABLE 351 * 3) __GFP_ACCOUNT 352 */ 353 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 354 return KMALLOC_DMA; 355 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 356 return KMALLOC_RECLAIM; 357 else 358 return KMALLOC_CGROUP; 359 } 360 361 /* 362 * Figure out which kmalloc slab an allocation of a certain size 363 * belongs to. 364 * 0 = zero alloc 365 * 1 = 65 .. 96 bytes 366 * 2 = 129 .. 192 bytes 367 * n = 2^(n-1)+1 .. 2^n 368 * 369 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 370 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 371 * Callers where !size_is_constant should only be test modules, where runtime 372 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 373 */ 374 static __always_inline unsigned int __kmalloc_index(size_t size, 375 bool size_is_constant) 376 { 377 if (!size) 378 return 0; 379 380 if (size <= KMALLOC_MIN_SIZE) 381 return KMALLOC_SHIFT_LOW; 382 383 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 384 return 1; 385 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 386 return 2; 387 if (size <= 8) return 3; 388 if (size <= 16) return 4; 389 if (size <= 32) return 5; 390 if (size <= 64) return 6; 391 if (size <= 128) return 7; 392 if (size <= 256) return 8; 393 if (size <= 512) return 9; 394 if (size <= 1024) return 10; 395 if (size <= 2 * 1024) return 11; 396 if (size <= 4 * 1024) return 12; 397 if (size <= 8 * 1024) return 13; 398 if (size <= 16 * 1024) return 14; 399 if (size <= 32 * 1024) return 15; 400 if (size <= 64 * 1024) return 16; 401 if (size <= 128 * 1024) return 17; 402 if (size <= 256 * 1024) return 18; 403 if (size <= 512 * 1024) return 19; 404 if (size <= 1024 * 1024) return 20; 405 if (size <= 2 * 1024 * 1024) return 21; 406 if (size <= 4 * 1024 * 1024) return 22; 407 if (size <= 8 * 1024 * 1024) return 23; 408 if (size <= 16 * 1024 * 1024) return 24; 409 if (size <= 32 * 1024 * 1024) return 25; 410 411 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 412 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 413 else 414 BUG(); 415 416 /* Will never be reached. Needed because the compiler may complain */ 417 return -1; 418 } 419 #define kmalloc_index(s) __kmalloc_index(s, true) 420 #endif /* !CONFIG_SLOB */ 421 422 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 423 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc; 424 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, 425 gfp_t gfpflags) __assume_slab_alignment __malloc; 426 void kmem_cache_free(struct kmem_cache *s, void *objp); 427 428 /* 429 * Bulk allocation and freeing operations. These are accelerated in an 430 * allocator specific way to avoid taking locks repeatedly or building 431 * metadata structures unnecessarily. 432 * 433 * Note that interrupts must be enabled when calling these functions. 434 */ 435 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 436 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 437 438 /* 439 * Caller must not use kfree_bulk() on memory not originally allocated 440 * by kmalloc(), because the SLOB allocator cannot handle this. 441 */ 442 static __always_inline void kfree_bulk(size_t size, void **p) 443 { 444 kmem_cache_free_bulk(NULL, size, p); 445 } 446 447 #ifdef CONFIG_NUMA 448 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 449 __alloc_size(1); 450 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 451 __malloc; 452 #else 453 static __always_inline __alloc_size(1) void *__kmalloc_node(size_t size, gfp_t flags, int node) 454 { 455 return __kmalloc(size, flags); 456 } 457 458 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 459 { 460 return kmem_cache_alloc(s, flags); 461 } 462 #endif 463 464 #ifdef CONFIG_TRACING 465 extern void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 466 __assume_slab_alignment __alloc_size(3); 467 468 #ifdef CONFIG_NUMA 469 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 470 int node, size_t size) __assume_slab_alignment 471 __alloc_size(4); 472 #else 473 static __always_inline __alloc_size(4) void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 474 gfp_t gfpflags, int node, size_t size) 475 { 476 return kmem_cache_alloc_trace(s, gfpflags, size); 477 } 478 #endif /* CONFIG_NUMA */ 479 480 #else /* CONFIG_TRACING */ 481 static __always_inline __alloc_size(3) void *kmem_cache_alloc_trace(struct kmem_cache *s, 482 gfp_t flags, size_t size) 483 { 484 void *ret = kmem_cache_alloc(s, flags); 485 486 ret = kasan_kmalloc(s, ret, size, flags); 487 return ret; 488 } 489 490 static __always_inline void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 491 int node, size_t size) 492 { 493 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 494 495 ret = kasan_kmalloc(s, ret, size, gfpflags); 496 return ret; 497 } 498 #endif /* CONFIG_TRACING */ 499 500 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment 501 __alloc_size(1); 502 503 #ifdef CONFIG_TRACING 504 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 505 __assume_page_alignment __alloc_size(1); 506 #else 507 static __always_inline __alloc_size(1) void *kmalloc_order_trace(size_t size, gfp_t flags, 508 unsigned int order) 509 { 510 return kmalloc_order(size, flags, order); 511 } 512 #endif 513 514 static __always_inline __alloc_size(1) void *kmalloc_large(size_t size, gfp_t flags) 515 { 516 unsigned int order = get_order(size); 517 return kmalloc_order_trace(size, flags, order); 518 } 519 520 /** 521 * kmalloc - allocate memory 522 * @size: how many bytes of memory are required. 523 * @flags: the type of memory to allocate. 524 * 525 * kmalloc is the normal method of allocating memory 526 * for objects smaller than page size in the kernel. 527 * 528 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 529 * bytes. For @size of power of two bytes, the alignment is also guaranteed 530 * to be at least to the size. 531 * 532 * The @flags argument may be one of the GFP flags defined at 533 * include/linux/gfp.h and described at 534 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 535 * 536 * The recommended usage of the @flags is described at 537 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 538 * 539 * Below is a brief outline of the most useful GFP flags 540 * 541 * %GFP_KERNEL 542 * Allocate normal kernel ram. May sleep. 543 * 544 * %GFP_NOWAIT 545 * Allocation will not sleep. 546 * 547 * %GFP_ATOMIC 548 * Allocation will not sleep. May use emergency pools. 549 * 550 * %GFP_HIGHUSER 551 * Allocate memory from high memory on behalf of user. 552 * 553 * Also it is possible to set different flags by OR'ing 554 * in one or more of the following additional @flags: 555 * 556 * %__GFP_HIGH 557 * This allocation has high priority and may use emergency pools. 558 * 559 * %__GFP_NOFAIL 560 * Indicate that this allocation is in no way allowed to fail 561 * (think twice before using). 562 * 563 * %__GFP_NORETRY 564 * If memory is not immediately available, 565 * then give up at once. 566 * 567 * %__GFP_NOWARN 568 * If allocation fails, don't issue any warnings. 569 * 570 * %__GFP_RETRY_MAYFAIL 571 * Try really hard to succeed the allocation but fail 572 * eventually. 573 */ 574 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 575 { 576 if (__builtin_constant_p(size)) { 577 #ifndef CONFIG_SLOB 578 unsigned int index; 579 #endif 580 if (size > KMALLOC_MAX_CACHE_SIZE) 581 return kmalloc_large(size, flags); 582 #ifndef CONFIG_SLOB 583 index = kmalloc_index(size); 584 585 if (!index) 586 return ZERO_SIZE_PTR; 587 588 return kmem_cache_alloc_trace( 589 kmalloc_caches[kmalloc_type(flags)][index], 590 flags, size); 591 #endif 592 } 593 return __kmalloc(size, flags); 594 } 595 596 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 597 { 598 #ifndef CONFIG_SLOB 599 if (__builtin_constant_p(size) && 600 size <= KMALLOC_MAX_CACHE_SIZE) { 601 unsigned int i = kmalloc_index(size); 602 603 if (!i) 604 return ZERO_SIZE_PTR; 605 606 return kmem_cache_alloc_node_trace( 607 kmalloc_caches[kmalloc_type(flags)][i], 608 flags, node, size); 609 } 610 #endif 611 return __kmalloc_node(size, flags, node); 612 } 613 614 /** 615 * kmalloc_array - allocate memory for an array. 616 * @n: number of elements. 617 * @size: element size. 618 * @flags: the type of memory to allocate (see kmalloc). 619 */ 620 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) 621 { 622 size_t bytes; 623 624 if (unlikely(check_mul_overflow(n, size, &bytes))) 625 return NULL; 626 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 627 return kmalloc(bytes, flags); 628 return __kmalloc(bytes, flags); 629 } 630 631 /** 632 * krealloc_array - reallocate memory for an array. 633 * @p: pointer to the memory chunk to reallocate 634 * @new_n: new number of elements to alloc 635 * @new_size: new size of a single member of the array 636 * @flags: the type of memory to allocate (see kmalloc) 637 */ 638 static inline __alloc_size(2, 3) void * __must_check krealloc_array(void *p, 639 size_t new_n, 640 size_t new_size, 641 gfp_t flags) 642 { 643 size_t bytes; 644 645 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 646 return NULL; 647 648 return krealloc(p, bytes, flags); 649 } 650 651 /** 652 * kcalloc - allocate memory for an array. The memory is set to zero. 653 * @n: number of elements. 654 * @size: element size. 655 * @flags: the type of memory to allocate (see kmalloc). 656 */ 657 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 658 { 659 return kmalloc_array(n, size, flags | __GFP_ZERO); 660 } 661 662 /* 663 * kmalloc_track_caller is a special version of kmalloc that records the 664 * calling function of the routine calling it for slab leak tracking instead 665 * of just the calling function (confusing, eh?). 666 * It's useful when the call to kmalloc comes from a widely-used standard 667 * allocator where we care about the real place the memory allocation 668 * request comes from. 669 */ 670 extern void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller); 671 #define kmalloc_track_caller(size, flags) \ 672 __kmalloc_track_caller(size, flags, _RET_IP_) 673 674 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 675 int node) 676 { 677 size_t bytes; 678 679 if (unlikely(check_mul_overflow(n, size, &bytes))) 680 return NULL; 681 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 682 return kmalloc_node(bytes, flags, node); 683 return __kmalloc_node(bytes, flags, node); 684 } 685 686 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 687 { 688 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 689 } 690 691 692 #ifdef CONFIG_NUMA 693 extern void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 694 unsigned long caller) __alloc_size(1); 695 #define kmalloc_node_track_caller(size, flags, node) \ 696 __kmalloc_node_track_caller(size, flags, node, \ 697 _RET_IP_) 698 699 #else /* CONFIG_NUMA */ 700 701 #define kmalloc_node_track_caller(size, flags, node) \ 702 kmalloc_track_caller(size, flags) 703 704 #endif /* CONFIG_NUMA */ 705 706 /* 707 * Shortcuts 708 */ 709 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 710 { 711 return kmem_cache_alloc(k, flags | __GFP_ZERO); 712 } 713 714 /** 715 * kzalloc - allocate memory. The memory is set to zero. 716 * @size: how many bytes of memory are required. 717 * @flags: the type of memory to allocate (see kmalloc). 718 */ 719 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 720 { 721 return kmalloc(size, flags | __GFP_ZERO); 722 } 723 724 /** 725 * kzalloc_node - allocate zeroed memory from a particular memory node. 726 * @size: how many bytes of memory are required. 727 * @flags: the type of memory to allocate (see kmalloc). 728 * @node: memory node from which to allocate 729 */ 730 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 731 { 732 return kmalloc_node(size, flags | __GFP_ZERO, node); 733 } 734 735 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 736 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 737 { 738 return kvmalloc_node(size, flags, NUMA_NO_NODE); 739 } 740 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 741 { 742 return kvmalloc_node(size, flags | __GFP_ZERO, node); 743 } 744 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 745 { 746 return kvmalloc(size, flags | __GFP_ZERO); 747 } 748 749 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 750 { 751 size_t bytes; 752 753 if (unlikely(check_mul_overflow(n, size, &bytes))) 754 return NULL; 755 756 return kvmalloc(bytes, flags); 757 } 758 759 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 760 { 761 return kvmalloc_array(n, size, flags | __GFP_ZERO); 762 } 763 764 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 765 __alloc_size(3); 766 extern void kvfree(const void *addr); 767 extern void kvfree_sensitive(const void *addr, size_t len); 768 769 unsigned int kmem_cache_size(struct kmem_cache *s); 770 void __init kmem_cache_init_late(void); 771 772 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 773 int slab_prepare_cpu(unsigned int cpu); 774 int slab_dead_cpu(unsigned int cpu); 775 #else 776 #define slab_prepare_cpu NULL 777 #define slab_dead_cpu NULL 778 #endif 779 780 #endif /* _LINUX_SLAB_H */ 781