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 /* The following flags affect the page allocator grouping pages by mobility */ 116 /* Objects are reclaimable */ 117 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) 118 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 119 120 /* Slab deactivation flag */ 121 #define SLAB_DEACTIVATED ((slab_flags_t __force)0x10000000U) 122 123 /* 124 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 125 * 126 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 127 * 128 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 129 * Both make kfree a no-op. 130 */ 131 #define ZERO_SIZE_PTR ((void *)16) 132 133 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 134 (unsigned long)ZERO_SIZE_PTR) 135 136 #include <linux/kasan.h> 137 138 struct mem_cgroup; 139 /* 140 * struct kmem_cache related prototypes 141 */ 142 void __init kmem_cache_init(void); 143 bool slab_is_available(void); 144 145 extern bool usercopy_fallback; 146 147 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 148 unsigned int align, slab_flags_t flags, 149 void (*ctor)(void *)); 150 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 151 unsigned int size, unsigned int align, 152 slab_flags_t flags, 153 unsigned int useroffset, unsigned int usersize, 154 void (*ctor)(void *)); 155 void kmem_cache_destroy(struct kmem_cache *s); 156 int kmem_cache_shrink(struct kmem_cache *s); 157 158 /* 159 * Please use this macro to create slab caches. Simply specify the 160 * name of the structure and maybe some flags that are listed above. 161 * 162 * The alignment of the struct determines object alignment. If you 163 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 164 * then the objects will be properly aligned in SMP configurations. 165 */ 166 #define KMEM_CACHE(__struct, __flags) \ 167 kmem_cache_create(#__struct, sizeof(struct __struct), \ 168 __alignof__(struct __struct), (__flags), NULL) 169 170 /* 171 * To whitelist a single field for copying to/from usercopy, use this 172 * macro instead for KMEM_CACHE() above. 173 */ 174 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 175 kmem_cache_create_usercopy(#__struct, \ 176 sizeof(struct __struct), \ 177 __alignof__(struct __struct), (__flags), \ 178 offsetof(struct __struct, __field), \ 179 sizeof_field(struct __struct, __field), NULL) 180 181 /* 182 * Common kmalloc functions provided by all allocators 183 */ 184 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __alloc_size(2); 185 void kfree(const void *objp); 186 void kfree_sensitive(const void *objp); 187 size_t __ksize(const void *objp); 188 size_t ksize(const void *objp); 189 #ifdef CONFIG_PRINTK 190 bool kmem_valid_obj(void *object); 191 void kmem_dump_obj(void *object); 192 #endif 193 194 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 195 void __check_heap_object(const void *ptr, unsigned long n, struct page *page, 196 bool to_user); 197 #else 198 static inline void __check_heap_object(const void *ptr, unsigned long n, 199 struct page *page, bool to_user) { } 200 #endif 201 202 /* 203 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 204 * alignment larger than the alignment of a 64-bit integer. 205 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. 206 */ 207 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 208 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 209 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 210 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 211 #else 212 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 213 #endif 214 215 /* 216 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 217 * Intended for arches that get misalignment faults even for 64 bit integer 218 * aligned buffers. 219 */ 220 #ifndef ARCH_SLAB_MINALIGN 221 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 222 #endif 223 224 /* 225 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned 226 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN 227 * aligned pointers. 228 */ 229 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 230 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 231 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 232 233 /* 234 * Kmalloc array related definitions 235 */ 236 237 #ifdef CONFIG_SLAB 238 /* 239 * The largest kmalloc size supported by the SLAB allocators is 240 * 32 megabyte (2^25) or the maximum allocatable page order if that is 241 * less than 32 MB. 242 * 243 * WARNING: Its not easy to increase this value since the allocators have 244 * to do various tricks to work around compiler limitations in order to 245 * ensure proper constant folding. 246 */ 247 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 248 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 249 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 250 #ifndef KMALLOC_SHIFT_LOW 251 #define KMALLOC_SHIFT_LOW 5 252 #endif 253 #endif 254 255 #ifdef CONFIG_SLUB 256 /* 257 * SLUB directly allocates requests fitting in to an order-1 page 258 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 259 */ 260 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 261 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 262 #ifndef KMALLOC_SHIFT_LOW 263 #define KMALLOC_SHIFT_LOW 3 264 #endif 265 #endif 266 267 #ifdef CONFIG_SLOB 268 /* 269 * SLOB passes all requests larger than one page to the page allocator. 270 * No kmalloc array is necessary since objects of different sizes can 271 * be allocated from the same page. 272 */ 273 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 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 /* Maximum allocatable size */ 281 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 282 /* Maximum size for which we actually use a slab cache */ 283 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 284 /* Maximum order allocatable via the slab allocator */ 285 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 286 287 /* 288 * Kmalloc subsystem. 289 */ 290 #ifndef KMALLOC_MIN_SIZE 291 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 292 #endif 293 294 /* 295 * This restriction comes from byte sized index implementation. 296 * Page size is normally 2^12 bytes and, in this case, if we want to use 297 * byte sized index which can represent 2^8 entries, the size of the object 298 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 299 * If minimum size of kmalloc is less than 16, we use it as minimum object 300 * size and give up to use byte sized index. 301 */ 302 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 303 (KMALLOC_MIN_SIZE) : 16) 304 305 /* 306 * Whenever changing this, take care of that kmalloc_type() and 307 * create_kmalloc_caches() still work as intended. 308 * 309 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 310 * is for accounted but unreclaimable and non-dma objects. All the other 311 * kmem caches can have both accounted and unaccounted objects. 312 */ 313 enum kmalloc_cache_type { 314 KMALLOC_NORMAL = 0, 315 #ifndef CONFIG_ZONE_DMA 316 KMALLOC_DMA = KMALLOC_NORMAL, 317 #endif 318 #ifndef CONFIG_MEMCG_KMEM 319 KMALLOC_CGROUP = KMALLOC_NORMAL, 320 #else 321 KMALLOC_CGROUP, 322 #endif 323 KMALLOC_RECLAIM, 324 #ifdef CONFIG_ZONE_DMA 325 KMALLOC_DMA, 326 #endif 327 NR_KMALLOC_TYPES 328 }; 329 330 #ifndef CONFIG_SLOB 331 extern struct kmem_cache * 332 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 333 334 /* 335 * Define gfp bits that should not be set for KMALLOC_NORMAL. 336 */ 337 #define KMALLOC_NOT_NORMAL_BITS \ 338 (__GFP_RECLAIMABLE | \ 339 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 340 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 341 342 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 343 { 344 /* 345 * The most common case is KMALLOC_NORMAL, so test for it 346 * with a single branch for all the relevant flags. 347 */ 348 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 349 return KMALLOC_NORMAL; 350 351 /* 352 * At least one of the flags has to be set. Their priorities in 353 * decreasing order are: 354 * 1) __GFP_DMA 355 * 2) __GFP_RECLAIMABLE 356 * 3) __GFP_ACCOUNT 357 */ 358 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 359 return KMALLOC_DMA; 360 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 361 return KMALLOC_RECLAIM; 362 else 363 return KMALLOC_CGROUP; 364 } 365 366 /* 367 * Figure out which kmalloc slab an allocation of a certain size 368 * belongs to. 369 * 0 = zero alloc 370 * 1 = 65 .. 96 bytes 371 * 2 = 129 .. 192 bytes 372 * n = 2^(n-1)+1 .. 2^n 373 * 374 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 375 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 376 * Callers where !size_is_constant should only be test modules, where runtime 377 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 378 */ 379 static __always_inline unsigned int __kmalloc_index(size_t size, 380 bool size_is_constant) 381 { 382 if (!size) 383 return 0; 384 385 if (size <= KMALLOC_MIN_SIZE) 386 return KMALLOC_SHIFT_LOW; 387 388 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 389 return 1; 390 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 391 return 2; 392 if (size <= 8) return 3; 393 if (size <= 16) return 4; 394 if (size <= 32) return 5; 395 if (size <= 64) return 6; 396 if (size <= 128) return 7; 397 if (size <= 256) return 8; 398 if (size <= 512) return 9; 399 if (size <= 1024) return 10; 400 if (size <= 2 * 1024) return 11; 401 if (size <= 4 * 1024) return 12; 402 if (size <= 8 * 1024) return 13; 403 if (size <= 16 * 1024) return 14; 404 if (size <= 32 * 1024) return 15; 405 if (size <= 64 * 1024) return 16; 406 if (size <= 128 * 1024) return 17; 407 if (size <= 256 * 1024) return 18; 408 if (size <= 512 * 1024) return 19; 409 if (size <= 1024 * 1024) return 20; 410 if (size <= 2 * 1024 * 1024) return 21; 411 if (size <= 4 * 1024 * 1024) return 22; 412 if (size <= 8 * 1024 * 1024) return 23; 413 if (size <= 16 * 1024 * 1024) return 24; 414 if (size <= 32 * 1024 * 1024) return 25; 415 416 if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 110000) 417 && !IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 418 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 419 else 420 BUG(); 421 422 /* Will never be reached. Needed because the compiler may complain */ 423 return -1; 424 } 425 #define kmalloc_index(s) __kmalloc_index(s, true) 426 #endif /* !CONFIG_SLOB */ 427 428 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 429 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc; 430 void kmem_cache_free(struct kmem_cache *s, void *objp); 431 432 /* 433 * Bulk allocation and freeing operations. These are accelerated in an 434 * allocator specific way to avoid taking locks repeatedly or building 435 * metadata structures unnecessarily. 436 * 437 * Note that interrupts must be enabled when calling these functions. 438 */ 439 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 440 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 441 442 /* 443 * Caller must not use kfree_bulk() on memory not originally allocated 444 * by kmalloc(), because the SLOB allocator cannot handle this. 445 */ 446 static __always_inline void kfree_bulk(size_t size, void **p) 447 { 448 kmem_cache_free_bulk(NULL, size, p); 449 } 450 451 #ifdef CONFIG_NUMA 452 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 453 __alloc_size(1); 454 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 455 __malloc; 456 #else 457 static __always_inline __alloc_size(1) void *__kmalloc_node(size_t size, gfp_t flags, int node) 458 { 459 return __kmalloc(size, flags); 460 } 461 462 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 463 { 464 return kmem_cache_alloc(s, flags); 465 } 466 #endif 467 468 #ifdef CONFIG_TRACING 469 extern void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 470 __assume_slab_alignment __alloc_size(3); 471 472 #ifdef CONFIG_NUMA 473 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 474 int node, size_t size) __assume_slab_alignment 475 __alloc_size(4); 476 #else 477 static __always_inline __alloc_size(4) void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 478 gfp_t gfpflags, int node, size_t size) 479 { 480 return kmem_cache_alloc_trace(s, gfpflags, size); 481 } 482 #endif /* CONFIG_NUMA */ 483 484 #else /* CONFIG_TRACING */ 485 static __always_inline __alloc_size(3) void *kmem_cache_alloc_trace(struct kmem_cache *s, 486 gfp_t flags, size_t size) 487 { 488 void *ret = kmem_cache_alloc(s, flags); 489 490 ret = kasan_kmalloc(s, ret, size, flags); 491 return ret; 492 } 493 494 static __always_inline void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 495 int node, size_t size) 496 { 497 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 498 499 ret = kasan_kmalloc(s, ret, size, gfpflags); 500 return ret; 501 } 502 #endif /* CONFIG_TRACING */ 503 504 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment 505 __alloc_size(1); 506 507 #ifdef CONFIG_TRACING 508 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 509 __assume_page_alignment __alloc_size(1); 510 #else 511 static __always_inline __alloc_size(1) void *kmalloc_order_trace(size_t size, gfp_t flags, 512 unsigned int order) 513 { 514 return kmalloc_order(size, flags, order); 515 } 516 #endif 517 518 static __always_inline __alloc_size(1) void *kmalloc_large(size_t size, gfp_t flags) 519 { 520 unsigned int order = get_order(size); 521 return kmalloc_order_trace(size, flags, order); 522 } 523 524 /** 525 * kmalloc - allocate memory 526 * @size: how many bytes of memory are required. 527 * @flags: the type of memory to allocate. 528 * 529 * kmalloc is the normal method of allocating memory 530 * for objects smaller than page size in the kernel. 531 * 532 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 533 * bytes. For @size of power of two bytes, the alignment is also guaranteed 534 * to be at least to the size. 535 * 536 * The @flags argument may be one of the GFP flags defined at 537 * include/linux/gfp.h and described at 538 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 539 * 540 * The recommended usage of the @flags is described at 541 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 542 * 543 * Below is a brief outline of the most useful GFP flags 544 * 545 * %GFP_KERNEL 546 * Allocate normal kernel ram. May sleep. 547 * 548 * %GFP_NOWAIT 549 * Allocation will not sleep. 550 * 551 * %GFP_ATOMIC 552 * Allocation will not sleep. May use emergency pools. 553 * 554 * %GFP_HIGHUSER 555 * Allocate memory from high memory on behalf of user. 556 * 557 * Also it is possible to set different flags by OR'ing 558 * in one or more of the following additional @flags: 559 * 560 * %__GFP_HIGH 561 * This allocation has high priority and may use emergency pools. 562 * 563 * %__GFP_NOFAIL 564 * Indicate that this allocation is in no way allowed to fail 565 * (think twice before using). 566 * 567 * %__GFP_NORETRY 568 * If memory is not immediately available, 569 * then give up at once. 570 * 571 * %__GFP_NOWARN 572 * If allocation fails, don't issue any warnings. 573 * 574 * %__GFP_RETRY_MAYFAIL 575 * Try really hard to succeed the allocation but fail 576 * eventually. 577 */ 578 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 579 { 580 if (__builtin_constant_p(size)) { 581 #ifndef CONFIG_SLOB 582 unsigned int index; 583 #endif 584 if (size > KMALLOC_MAX_CACHE_SIZE) 585 return kmalloc_large(size, flags); 586 #ifndef CONFIG_SLOB 587 index = kmalloc_index(size); 588 589 if (!index) 590 return ZERO_SIZE_PTR; 591 592 return kmem_cache_alloc_trace( 593 kmalloc_caches[kmalloc_type(flags)][index], 594 flags, size); 595 #endif 596 } 597 return __kmalloc(size, flags); 598 } 599 600 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 601 { 602 #ifndef CONFIG_SLOB 603 if (__builtin_constant_p(size) && 604 size <= KMALLOC_MAX_CACHE_SIZE) { 605 unsigned int i = kmalloc_index(size); 606 607 if (!i) 608 return ZERO_SIZE_PTR; 609 610 return kmem_cache_alloc_node_trace( 611 kmalloc_caches[kmalloc_type(flags)][i], 612 flags, node, size); 613 } 614 #endif 615 return __kmalloc_node(size, flags, node); 616 } 617 618 /** 619 * kmalloc_array - allocate memory for an array. 620 * @n: number of elements. 621 * @size: element size. 622 * @flags: the type of memory to allocate (see kmalloc). 623 */ 624 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) 625 { 626 size_t bytes; 627 628 if (unlikely(check_mul_overflow(n, size, &bytes))) 629 return NULL; 630 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 631 return kmalloc(bytes, flags); 632 return __kmalloc(bytes, flags); 633 } 634 635 /** 636 * krealloc_array - reallocate memory for an array. 637 * @p: pointer to the memory chunk to reallocate 638 * @new_n: new number of elements to alloc 639 * @new_size: new size of a single member of the array 640 * @flags: the type of memory to allocate (see kmalloc) 641 */ 642 static inline __alloc_size(2, 3) void * __must_check krealloc_array(void *p, 643 size_t new_n, 644 size_t new_size, 645 gfp_t flags) 646 { 647 size_t bytes; 648 649 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 650 return NULL; 651 652 return krealloc(p, bytes, flags); 653 } 654 655 /** 656 * kcalloc - allocate memory for an array. The memory is set to zero. 657 * @n: number of elements. 658 * @size: element size. 659 * @flags: the type of memory to allocate (see kmalloc). 660 */ 661 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 662 { 663 return kmalloc_array(n, size, flags | __GFP_ZERO); 664 } 665 666 /* 667 * kmalloc_track_caller is a special version of kmalloc that records the 668 * calling function of the routine calling it for slab leak tracking instead 669 * of just the calling function (confusing, eh?). 670 * It's useful when the call to kmalloc comes from a widely-used standard 671 * allocator where we care about the real place the memory allocation 672 * request comes from. 673 */ 674 extern void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) 675 __alloc_size(1); 676 #define kmalloc_track_caller(size, flags) \ 677 __kmalloc_track_caller(size, flags, _RET_IP_) 678 679 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 680 int node) 681 { 682 size_t bytes; 683 684 if (unlikely(check_mul_overflow(n, size, &bytes))) 685 return NULL; 686 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 687 return kmalloc_node(bytes, flags, node); 688 return __kmalloc_node(bytes, flags, node); 689 } 690 691 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 692 { 693 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 694 } 695 696 697 #ifdef CONFIG_NUMA 698 extern void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 699 unsigned long caller) __alloc_size(1); 700 #define kmalloc_node_track_caller(size, flags, node) \ 701 __kmalloc_node_track_caller(size, flags, node, \ 702 _RET_IP_) 703 704 #else /* CONFIG_NUMA */ 705 706 #define kmalloc_node_track_caller(size, flags, node) \ 707 kmalloc_track_caller(size, flags) 708 709 #endif /* CONFIG_NUMA */ 710 711 /* 712 * Shortcuts 713 */ 714 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 715 { 716 return kmem_cache_alloc(k, flags | __GFP_ZERO); 717 } 718 719 /** 720 * kzalloc - allocate memory. The memory is set to zero. 721 * @size: how many bytes of memory are required. 722 * @flags: the type of memory to allocate (see kmalloc). 723 */ 724 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 725 { 726 return kmalloc(size, flags | __GFP_ZERO); 727 } 728 729 /** 730 * kzalloc_node - allocate zeroed memory from a particular memory node. 731 * @size: how many bytes of memory are required. 732 * @flags: the type of memory to allocate (see kmalloc). 733 * @node: memory node from which to allocate 734 */ 735 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 736 { 737 return kmalloc_node(size, flags | __GFP_ZERO, node); 738 } 739 740 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 741 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 742 { 743 return kvmalloc_node(size, flags, NUMA_NO_NODE); 744 } 745 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 746 { 747 return kvmalloc_node(size, flags | __GFP_ZERO, node); 748 } 749 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 750 { 751 return kvmalloc(size, flags | __GFP_ZERO); 752 } 753 754 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 755 { 756 size_t bytes; 757 758 if (unlikely(check_mul_overflow(n, size, &bytes))) 759 return NULL; 760 761 return kvmalloc(bytes, flags); 762 } 763 764 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 765 { 766 return kvmalloc_array(n, size, flags | __GFP_ZERO); 767 } 768 769 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 770 __alloc_size(3); 771 extern void kvfree(const void *addr); 772 extern void kvfree_sensitive(const void *addr, size_t len); 773 774 unsigned int kmem_cache_size(struct kmem_cache *s); 775 void __init kmem_cache_init_late(void); 776 777 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 778 int slab_prepare_cpu(unsigned int cpu); 779 int slab_dead_cpu(unsigned int cpu); 780 #else 781 #define slab_prepare_cpu NULL 782 #define slab_dead_cpu NULL 783 #endif 784 785 #endif /* _LINUX_SLAB_H */ 786