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_GENERIC 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 #ifdef CONFIG_KFENCE 123 #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U) 124 #else 125 #define SLAB_SKIP_KFENCE 0 126 #endif 127 128 /* The following flags affect the page allocator grouping pages by mobility */ 129 /* Objects are reclaimable */ 130 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) 131 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 132 133 /* 134 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 135 * 136 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 137 * 138 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 139 * Both make kfree a no-op. 140 */ 141 #define ZERO_SIZE_PTR ((void *)16) 142 143 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 144 (unsigned long)ZERO_SIZE_PTR) 145 146 #include <linux/kasan.h> 147 148 struct list_lru; 149 struct mem_cgroup; 150 /* 151 * struct kmem_cache related prototypes 152 */ 153 void __init kmem_cache_init(void); 154 bool slab_is_available(void); 155 156 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 157 unsigned int align, slab_flags_t flags, 158 void (*ctor)(void *)); 159 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 160 unsigned int size, unsigned int align, 161 slab_flags_t flags, 162 unsigned int useroffset, unsigned int usersize, 163 void (*ctor)(void *)); 164 void kmem_cache_destroy(struct kmem_cache *s); 165 int kmem_cache_shrink(struct kmem_cache *s); 166 167 /* 168 * Please use this macro to create slab caches. Simply specify the 169 * name of the structure and maybe some flags that are listed above. 170 * 171 * The alignment of the struct determines object alignment. If you 172 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 173 * then the objects will be properly aligned in SMP configurations. 174 */ 175 #define KMEM_CACHE(__struct, __flags) \ 176 kmem_cache_create(#__struct, sizeof(struct __struct), \ 177 __alignof__(struct __struct), (__flags), NULL) 178 179 /* 180 * To whitelist a single field for copying to/from usercopy, use this 181 * macro instead for KMEM_CACHE() above. 182 */ 183 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 184 kmem_cache_create_usercopy(#__struct, \ 185 sizeof(struct __struct), \ 186 __alignof__(struct __struct), (__flags), \ 187 offsetof(struct __struct, __field), \ 188 sizeof_field(struct __struct, __field), NULL) 189 190 /* 191 * Common kmalloc functions provided by all allocators 192 */ 193 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __alloc_size(2); 194 void kfree(const void *objp); 195 void kfree_sensitive(const void *objp); 196 size_t __ksize(const void *objp); 197 size_t ksize(const void *objp); 198 #ifdef CONFIG_PRINTK 199 bool kmem_valid_obj(void *object); 200 void kmem_dump_obj(void *object); 201 #endif 202 203 /* 204 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 205 * alignment larger than the alignment of a 64-bit integer. 206 * Setting ARCH_DMA_MINALIGN in arch headers allows that. 207 */ 208 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 209 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 210 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 211 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 212 #else 213 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 214 #endif 215 216 /* 217 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 218 * Intended for arches that get misalignment faults even for 64 bit integer 219 * aligned buffers. 220 */ 221 #ifndef ARCH_SLAB_MINALIGN 222 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 223 #endif 224 225 /* 226 * Arches can define this function if they want to decide the minimum slab 227 * alignment at runtime. The value returned by the function must be a power 228 * of two and >= ARCH_SLAB_MINALIGN. 229 */ 230 #ifndef arch_slab_minalign 231 static inline unsigned int arch_slab_minalign(void) 232 { 233 return ARCH_SLAB_MINALIGN; 234 } 235 #endif 236 237 /* 238 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN. 239 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN 240 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment. 241 */ 242 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 243 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 244 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 245 246 /* 247 * Kmalloc array related definitions 248 */ 249 250 #ifdef CONFIG_SLAB 251 /* 252 * The largest kmalloc size supported by the SLAB allocators is 253 * 32 megabyte (2^25) or the maximum allocatable page order if that is 254 * less than 32 MB. 255 * 256 * WARNING: Its not easy to increase this value since the allocators have 257 * to do various tricks to work around compiler limitations in order to 258 * ensure proper constant folding. 259 */ 260 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 261 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 262 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 263 #ifndef KMALLOC_SHIFT_LOW 264 #define KMALLOC_SHIFT_LOW 5 265 #endif 266 #endif 267 268 #ifdef CONFIG_SLUB 269 /* 270 * SLUB directly allocates requests fitting in to an order-1 page 271 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 272 */ 273 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 274 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 275 #ifndef KMALLOC_SHIFT_LOW 276 #define KMALLOC_SHIFT_LOW 3 277 #endif 278 #endif 279 280 #ifdef CONFIG_SLOB 281 /* 282 * SLOB passes all requests larger than one page to the page allocator. 283 * No kmalloc array is necessary since objects of different sizes can 284 * be allocated from the same page. 285 */ 286 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 287 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 288 #ifndef KMALLOC_SHIFT_LOW 289 #define KMALLOC_SHIFT_LOW 3 290 #endif 291 #endif 292 293 /* Maximum allocatable size */ 294 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 295 /* Maximum size for which we actually use a slab cache */ 296 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 297 /* Maximum order allocatable via the slab allocator */ 298 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 299 300 /* 301 * Kmalloc subsystem. 302 */ 303 #ifndef KMALLOC_MIN_SIZE 304 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 305 #endif 306 307 /* 308 * This restriction comes from byte sized index implementation. 309 * Page size is normally 2^12 bytes and, in this case, if we want to use 310 * byte sized index which can represent 2^8 entries, the size of the object 311 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 312 * If minimum size of kmalloc is less than 16, we use it as minimum object 313 * size and give up to use byte sized index. 314 */ 315 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 316 (KMALLOC_MIN_SIZE) : 16) 317 318 /* 319 * Whenever changing this, take care of that kmalloc_type() and 320 * create_kmalloc_caches() still work as intended. 321 * 322 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 323 * is for accounted but unreclaimable and non-dma objects. All the other 324 * kmem caches can have both accounted and unaccounted objects. 325 */ 326 enum kmalloc_cache_type { 327 KMALLOC_NORMAL = 0, 328 #ifndef CONFIG_ZONE_DMA 329 KMALLOC_DMA = KMALLOC_NORMAL, 330 #endif 331 #ifndef CONFIG_MEMCG_KMEM 332 KMALLOC_CGROUP = KMALLOC_NORMAL, 333 #else 334 KMALLOC_CGROUP, 335 #endif 336 KMALLOC_RECLAIM, 337 #ifdef CONFIG_ZONE_DMA 338 KMALLOC_DMA, 339 #endif 340 NR_KMALLOC_TYPES 341 }; 342 343 #ifndef CONFIG_SLOB 344 extern struct kmem_cache * 345 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 346 347 /* 348 * Define gfp bits that should not be set for KMALLOC_NORMAL. 349 */ 350 #define KMALLOC_NOT_NORMAL_BITS \ 351 (__GFP_RECLAIMABLE | \ 352 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 353 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 354 355 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 356 { 357 /* 358 * The most common case is KMALLOC_NORMAL, so test for it 359 * with a single branch for all the relevant flags. 360 */ 361 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 362 return KMALLOC_NORMAL; 363 364 /* 365 * At least one of the flags has to be set. Their priorities in 366 * decreasing order are: 367 * 1) __GFP_DMA 368 * 2) __GFP_RECLAIMABLE 369 * 3) __GFP_ACCOUNT 370 */ 371 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 372 return KMALLOC_DMA; 373 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 374 return KMALLOC_RECLAIM; 375 else 376 return KMALLOC_CGROUP; 377 } 378 379 /* 380 * Figure out which kmalloc slab an allocation of a certain size 381 * belongs to. 382 * 0 = zero alloc 383 * 1 = 65 .. 96 bytes 384 * 2 = 129 .. 192 bytes 385 * n = 2^(n-1)+1 .. 2^n 386 * 387 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 388 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 389 * Callers where !size_is_constant should only be test modules, where runtime 390 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 391 */ 392 static __always_inline unsigned int __kmalloc_index(size_t size, 393 bool size_is_constant) 394 { 395 if (!size) 396 return 0; 397 398 if (size <= KMALLOC_MIN_SIZE) 399 return KMALLOC_SHIFT_LOW; 400 401 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 402 return 1; 403 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 404 return 2; 405 if (size <= 8) return 3; 406 if (size <= 16) return 4; 407 if (size <= 32) return 5; 408 if (size <= 64) return 6; 409 if (size <= 128) return 7; 410 if (size <= 256) return 8; 411 if (size <= 512) return 9; 412 if (size <= 1024) return 10; 413 if (size <= 2 * 1024) return 11; 414 if (size <= 4 * 1024) return 12; 415 if (size <= 8 * 1024) return 13; 416 if (size <= 16 * 1024) return 14; 417 if (size <= 32 * 1024) return 15; 418 if (size <= 64 * 1024) return 16; 419 if (size <= 128 * 1024) return 17; 420 if (size <= 256 * 1024) return 18; 421 if (size <= 512 * 1024) return 19; 422 if (size <= 1024 * 1024) return 20; 423 if (size <= 2 * 1024 * 1024) return 21; 424 if (size <= 4 * 1024 * 1024) return 22; 425 if (size <= 8 * 1024 * 1024) return 23; 426 if (size <= 16 * 1024 * 1024) return 24; 427 if (size <= 32 * 1024 * 1024) return 25; 428 429 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 430 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 431 else 432 BUG(); 433 434 /* Will never be reached. Needed because the compiler may complain */ 435 return -1; 436 } 437 #define kmalloc_index(s) __kmalloc_index(s, true) 438 #endif /* !CONFIG_SLOB */ 439 440 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 441 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc; 442 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, 443 gfp_t gfpflags) __assume_slab_alignment __malloc; 444 void kmem_cache_free(struct kmem_cache *s, void *objp); 445 446 /* 447 * Bulk allocation and freeing operations. These are accelerated in an 448 * allocator specific way to avoid taking locks repeatedly or building 449 * metadata structures unnecessarily. 450 * 451 * Note that interrupts must be enabled when calling these functions. 452 */ 453 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 454 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 455 456 /* 457 * Caller must not use kfree_bulk() on memory not originally allocated 458 * by kmalloc(), because the SLOB allocator cannot handle this. 459 */ 460 static __always_inline void kfree_bulk(size_t size, void **p) 461 { 462 kmem_cache_free_bulk(NULL, size, p); 463 } 464 465 #ifdef CONFIG_NUMA 466 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 467 __alloc_size(1); 468 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 469 __malloc; 470 #else 471 static __always_inline __alloc_size(1) void *__kmalloc_node(size_t size, gfp_t flags, int node) 472 { 473 return __kmalloc(size, flags); 474 } 475 476 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 477 { 478 return kmem_cache_alloc(s, flags); 479 } 480 #endif 481 482 #ifdef CONFIG_TRACING 483 extern void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 484 __assume_slab_alignment __alloc_size(3); 485 486 #ifdef CONFIG_NUMA 487 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 488 int node, size_t size) __assume_slab_alignment 489 __alloc_size(4); 490 #else 491 static __always_inline __alloc_size(4) void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 492 gfp_t gfpflags, int node, size_t size) 493 { 494 return kmem_cache_alloc_trace(s, gfpflags, size); 495 } 496 #endif /* CONFIG_NUMA */ 497 498 #else /* CONFIG_TRACING */ 499 static __always_inline __alloc_size(3) void *kmem_cache_alloc_trace(struct kmem_cache *s, 500 gfp_t flags, size_t size) 501 { 502 void *ret = kmem_cache_alloc(s, flags); 503 504 ret = kasan_kmalloc(s, ret, size, flags); 505 return ret; 506 } 507 508 static __always_inline void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 509 int node, size_t size) 510 { 511 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 512 513 ret = kasan_kmalloc(s, ret, size, gfpflags); 514 return ret; 515 } 516 #endif /* CONFIG_TRACING */ 517 518 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment 519 __alloc_size(1); 520 521 #ifdef CONFIG_TRACING 522 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 523 __assume_page_alignment __alloc_size(1); 524 #else 525 static __always_inline __alloc_size(1) void *kmalloc_order_trace(size_t size, gfp_t flags, 526 unsigned int order) 527 { 528 return kmalloc_order(size, flags, order); 529 } 530 #endif 531 532 static __always_inline __alloc_size(1) void *kmalloc_large(size_t size, gfp_t flags) 533 { 534 unsigned int order = get_order(size); 535 return kmalloc_order_trace(size, flags, order); 536 } 537 538 /** 539 * kmalloc - allocate memory 540 * @size: how many bytes of memory are required. 541 * @flags: the type of memory to allocate. 542 * 543 * kmalloc is the normal method of allocating memory 544 * for objects smaller than page size in the kernel. 545 * 546 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 547 * bytes. For @size of power of two bytes, the alignment is also guaranteed 548 * to be at least to the size. 549 * 550 * The @flags argument may be one of the GFP flags defined at 551 * include/linux/gfp.h and described at 552 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 553 * 554 * The recommended usage of the @flags is described at 555 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 556 * 557 * Below is a brief outline of the most useful GFP flags 558 * 559 * %GFP_KERNEL 560 * Allocate normal kernel ram. May sleep. 561 * 562 * %GFP_NOWAIT 563 * Allocation will not sleep. 564 * 565 * %GFP_ATOMIC 566 * Allocation will not sleep. May use emergency pools. 567 * 568 * %GFP_HIGHUSER 569 * Allocate memory from high memory on behalf of user. 570 * 571 * Also it is possible to set different flags by OR'ing 572 * in one or more of the following additional @flags: 573 * 574 * %__GFP_HIGH 575 * This allocation has high priority and may use emergency pools. 576 * 577 * %__GFP_NOFAIL 578 * Indicate that this allocation is in no way allowed to fail 579 * (think twice before using). 580 * 581 * %__GFP_NORETRY 582 * If memory is not immediately available, 583 * then give up at once. 584 * 585 * %__GFP_NOWARN 586 * If allocation fails, don't issue any warnings. 587 * 588 * %__GFP_RETRY_MAYFAIL 589 * Try really hard to succeed the allocation but fail 590 * eventually. 591 */ 592 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 593 { 594 if (__builtin_constant_p(size)) { 595 #ifndef CONFIG_SLOB 596 unsigned int index; 597 #endif 598 if (size > KMALLOC_MAX_CACHE_SIZE) 599 return kmalloc_large(size, flags); 600 #ifndef CONFIG_SLOB 601 index = kmalloc_index(size); 602 603 if (!index) 604 return ZERO_SIZE_PTR; 605 606 return kmem_cache_alloc_trace( 607 kmalloc_caches[kmalloc_type(flags)][index], 608 flags, size); 609 #endif 610 } 611 return __kmalloc(size, flags); 612 } 613 614 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 615 { 616 #ifndef CONFIG_SLOB 617 if (__builtin_constant_p(size) && 618 size <= KMALLOC_MAX_CACHE_SIZE) { 619 unsigned int i = kmalloc_index(size); 620 621 if (!i) 622 return ZERO_SIZE_PTR; 623 624 return kmem_cache_alloc_node_trace( 625 kmalloc_caches[kmalloc_type(flags)][i], 626 flags, node, size); 627 } 628 #endif 629 return __kmalloc_node(size, flags, node); 630 } 631 632 /** 633 * kmalloc_array - allocate memory for an array. 634 * @n: number of elements. 635 * @size: element size. 636 * @flags: the type of memory to allocate (see kmalloc). 637 */ 638 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) 639 { 640 size_t bytes; 641 642 if (unlikely(check_mul_overflow(n, size, &bytes))) 643 return NULL; 644 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 645 return kmalloc(bytes, flags); 646 return __kmalloc(bytes, flags); 647 } 648 649 /** 650 * krealloc_array - reallocate memory for an array. 651 * @p: pointer to the memory chunk to reallocate 652 * @new_n: new number of elements to alloc 653 * @new_size: new size of a single member of the array 654 * @flags: the type of memory to allocate (see kmalloc) 655 */ 656 static inline __alloc_size(2, 3) void * __must_check krealloc_array(void *p, 657 size_t new_n, 658 size_t new_size, 659 gfp_t flags) 660 { 661 size_t bytes; 662 663 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 664 return NULL; 665 666 return krealloc(p, bytes, flags); 667 } 668 669 /** 670 * kcalloc - allocate memory for an array. The memory is set to zero. 671 * @n: number of elements. 672 * @size: element size. 673 * @flags: the type of memory to allocate (see kmalloc). 674 */ 675 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 676 { 677 return kmalloc_array(n, size, flags | __GFP_ZERO); 678 } 679 680 /* 681 * kmalloc_track_caller is a special version of kmalloc that records the 682 * calling function of the routine calling it for slab leak tracking instead 683 * of just the calling function (confusing, eh?). 684 * It's useful when the call to kmalloc comes from a widely-used standard 685 * allocator where we care about the real place the memory allocation 686 * request comes from. 687 */ 688 extern void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller); 689 #define kmalloc_track_caller(size, flags) \ 690 __kmalloc_track_caller(size, flags, _RET_IP_) 691 692 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 693 int node) 694 { 695 size_t bytes; 696 697 if (unlikely(check_mul_overflow(n, size, &bytes))) 698 return NULL; 699 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 700 return kmalloc_node(bytes, flags, node); 701 return __kmalloc_node(bytes, flags, node); 702 } 703 704 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 705 { 706 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 707 } 708 709 710 #ifdef CONFIG_NUMA 711 extern void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 712 unsigned long caller) __alloc_size(1); 713 #define kmalloc_node_track_caller(size, flags, node) \ 714 __kmalloc_node_track_caller(size, flags, node, \ 715 _RET_IP_) 716 717 #else /* CONFIG_NUMA */ 718 719 #define kmalloc_node_track_caller(size, flags, node) \ 720 kmalloc_track_caller(size, flags) 721 722 #endif /* CONFIG_NUMA */ 723 724 /* 725 * Shortcuts 726 */ 727 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 728 { 729 return kmem_cache_alloc(k, flags | __GFP_ZERO); 730 } 731 732 /** 733 * kzalloc - allocate memory. The memory is set to zero. 734 * @size: how many bytes of memory are required. 735 * @flags: the type of memory to allocate (see kmalloc). 736 */ 737 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 738 { 739 return kmalloc(size, flags | __GFP_ZERO); 740 } 741 742 /** 743 * kzalloc_node - allocate zeroed memory from a particular memory node. 744 * @size: how many bytes of memory are required. 745 * @flags: the type of memory to allocate (see kmalloc). 746 * @node: memory node from which to allocate 747 */ 748 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 749 { 750 return kmalloc_node(size, flags | __GFP_ZERO, node); 751 } 752 753 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 754 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 755 { 756 return kvmalloc_node(size, flags, NUMA_NO_NODE); 757 } 758 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 759 { 760 return kvmalloc_node(size, flags | __GFP_ZERO, node); 761 } 762 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 763 { 764 return kvmalloc(size, flags | __GFP_ZERO); 765 } 766 767 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 768 { 769 size_t bytes; 770 771 if (unlikely(check_mul_overflow(n, size, &bytes))) 772 return NULL; 773 774 return kvmalloc(bytes, flags); 775 } 776 777 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 778 { 779 return kvmalloc_array(n, size, flags | __GFP_ZERO); 780 } 781 782 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 783 __alloc_size(3); 784 extern void kvfree(const void *addr); 785 extern void kvfree_sensitive(const void *addr, size_t len); 786 787 unsigned int kmem_cache_size(struct kmem_cache *s); 788 void __init kmem_cache_init_late(void); 789 790 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 791 int slab_prepare_cpu(unsigned int cpu); 792 int slab_dead_cpu(unsigned int cpu); 793 #else 794 #define slab_prepare_cpu NULL 795 #define slab_dead_cpu NULL 796 #endif 797 798 #endif /* _LINUX_SLAB_H */ 799