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