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 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, 146 unsigned int align, slab_flags_t flags, 147 void (*ctor)(void *)); 148 struct kmem_cache *kmem_cache_create_usercopy(const char *name, 149 unsigned int size, unsigned int align, 150 slab_flags_t flags, 151 unsigned int useroffset, unsigned int usersize, 152 void (*ctor)(void *)); 153 void kmem_cache_destroy(struct kmem_cache *s); 154 int kmem_cache_shrink(struct kmem_cache *s); 155 156 /* 157 * Please use this macro to create slab caches. Simply specify the 158 * name of the structure and maybe some flags that are listed above. 159 * 160 * The alignment of the struct determines object alignment. If you 161 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 162 * then the objects will be properly aligned in SMP configurations. 163 */ 164 #define KMEM_CACHE(__struct, __flags) \ 165 kmem_cache_create(#__struct, sizeof(struct __struct), \ 166 __alignof__(struct __struct), (__flags), NULL) 167 168 /* 169 * To whitelist a single field for copying to/from usercopy, use this 170 * macro instead for KMEM_CACHE() above. 171 */ 172 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ 173 kmem_cache_create_usercopy(#__struct, \ 174 sizeof(struct __struct), \ 175 __alignof__(struct __struct), (__flags), \ 176 offsetof(struct __struct, __field), \ 177 sizeof_field(struct __struct, __field), NULL) 178 179 /* 180 * Common kmalloc functions provided by all allocators 181 */ 182 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __alloc_size(2); 183 void kfree(const void *objp); 184 void kfree_sensitive(const void *objp); 185 size_t __ksize(const void *objp); 186 size_t ksize(const void *objp); 187 #ifdef CONFIG_PRINTK 188 bool kmem_valid_obj(void *object); 189 void kmem_dump_obj(void *object); 190 #endif 191 192 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 193 void __check_heap_object(const void *ptr, unsigned long n, struct page *page, 194 bool to_user); 195 #else 196 static inline void __check_heap_object(const void *ptr, unsigned long n, 197 struct page *page, bool to_user) { } 198 #endif 199 200 /* 201 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 202 * alignment larger than the alignment of a 64-bit integer. 203 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. 204 */ 205 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 206 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 207 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 208 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 209 #else 210 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 211 #endif 212 213 /* 214 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 215 * Intended for arches that get misalignment faults even for 64 bit integer 216 * aligned buffers. 217 */ 218 #ifndef ARCH_SLAB_MINALIGN 219 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 220 #endif 221 222 /* 223 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned 224 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN 225 * aligned pointers. 226 */ 227 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 228 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 229 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 230 231 /* 232 * Kmalloc array related definitions 233 */ 234 235 #ifdef CONFIG_SLAB 236 /* 237 * The largest kmalloc size supported by the SLAB allocators is 238 * 32 megabyte (2^25) or the maximum allocatable page order if that is 239 * less than 32 MB. 240 * 241 * WARNING: Its not easy to increase this value since the allocators have 242 * to do various tricks to work around compiler limitations in order to 243 * ensure proper constant folding. 244 */ 245 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 246 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 247 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 248 #ifndef KMALLOC_SHIFT_LOW 249 #define KMALLOC_SHIFT_LOW 5 250 #endif 251 #endif 252 253 #ifdef CONFIG_SLUB 254 /* 255 * SLUB directly allocates requests fitting in to an order-1 page 256 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 257 */ 258 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 259 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 260 #ifndef KMALLOC_SHIFT_LOW 261 #define KMALLOC_SHIFT_LOW 3 262 #endif 263 #endif 264 265 #ifdef CONFIG_SLOB 266 /* 267 * SLOB passes all requests larger than one page to the page allocator. 268 * No kmalloc array is necessary since objects of different sizes can 269 * be allocated from the same page. 270 */ 271 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 272 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 273 #ifndef KMALLOC_SHIFT_LOW 274 #define KMALLOC_SHIFT_LOW 3 275 #endif 276 #endif 277 278 /* Maximum allocatable size */ 279 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 280 /* Maximum size for which we actually use a slab cache */ 281 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 282 /* Maximum order allocatable via the slab allocator */ 283 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 284 285 /* 286 * Kmalloc subsystem. 287 */ 288 #ifndef KMALLOC_MIN_SIZE 289 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 290 #endif 291 292 /* 293 * This restriction comes from byte sized index implementation. 294 * Page size is normally 2^12 bytes and, in this case, if we want to use 295 * byte sized index which can represent 2^8 entries, the size of the object 296 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 297 * If minimum size of kmalloc is less than 16, we use it as minimum object 298 * size and give up to use byte sized index. 299 */ 300 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 301 (KMALLOC_MIN_SIZE) : 16) 302 303 /* 304 * Whenever changing this, take care of that kmalloc_type() and 305 * create_kmalloc_caches() still work as intended. 306 * 307 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 308 * is for accounted but unreclaimable and non-dma objects. All the other 309 * kmem caches can have both accounted and unaccounted objects. 310 */ 311 enum kmalloc_cache_type { 312 KMALLOC_NORMAL = 0, 313 #ifndef CONFIG_ZONE_DMA 314 KMALLOC_DMA = KMALLOC_NORMAL, 315 #endif 316 #ifndef CONFIG_MEMCG_KMEM 317 KMALLOC_CGROUP = KMALLOC_NORMAL, 318 #else 319 KMALLOC_CGROUP, 320 #endif 321 KMALLOC_RECLAIM, 322 #ifdef CONFIG_ZONE_DMA 323 KMALLOC_DMA, 324 #endif 325 NR_KMALLOC_TYPES 326 }; 327 328 #ifndef CONFIG_SLOB 329 extern struct kmem_cache * 330 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 331 332 /* 333 * Define gfp bits that should not be set for KMALLOC_NORMAL. 334 */ 335 #define KMALLOC_NOT_NORMAL_BITS \ 336 (__GFP_RECLAIMABLE | \ 337 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 338 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 339 340 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 341 { 342 /* 343 * The most common case is KMALLOC_NORMAL, so test for it 344 * with a single branch for all the relevant flags. 345 */ 346 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 347 return KMALLOC_NORMAL; 348 349 /* 350 * At least one of the flags has to be set. Their priorities in 351 * decreasing order are: 352 * 1) __GFP_DMA 353 * 2) __GFP_RECLAIMABLE 354 * 3) __GFP_ACCOUNT 355 */ 356 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 357 return KMALLOC_DMA; 358 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 359 return KMALLOC_RECLAIM; 360 else 361 return KMALLOC_CGROUP; 362 } 363 364 /* 365 * Figure out which kmalloc slab an allocation of a certain size 366 * belongs to. 367 * 0 = zero alloc 368 * 1 = 65 .. 96 bytes 369 * 2 = 129 .. 192 bytes 370 * n = 2^(n-1)+1 .. 2^n 371 * 372 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 373 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 374 * Callers where !size_is_constant should only be test modules, where runtime 375 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 376 */ 377 static __always_inline unsigned int __kmalloc_index(size_t size, 378 bool size_is_constant) 379 { 380 if (!size) 381 return 0; 382 383 if (size <= KMALLOC_MIN_SIZE) 384 return KMALLOC_SHIFT_LOW; 385 386 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 387 return 1; 388 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 389 return 2; 390 if (size <= 8) return 3; 391 if (size <= 16) return 4; 392 if (size <= 32) return 5; 393 if (size <= 64) return 6; 394 if (size <= 128) return 7; 395 if (size <= 256) return 8; 396 if (size <= 512) return 9; 397 if (size <= 1024) return 10; 398 if (size <= 2 * 1024) return 11; 399 if (size <= 4 * 1024) return 12; 400 if (size <= 8 * 1024) return 13; 401 if (size <= 16 * 1024) return 14; 402 if (size <= 32 * 1024) return 15; 403 if (size <= 64 * 1024) return 16; 404 if (size <= 128 * 1024) return 17; 405 if (size <= 256 * 1024) return 18; 406 if (size <= 512 * 1024) return 19; 407 if (size <= 1024 * 1024) return 20; 408 if (size <= 2 * 1024 * 1024) return 21; 409 if (size <= 4 * 1024 * 1024) return 22; 410 if (size <= 8 * 1024 * 1024) return 23; 411 if (size <= 16 * 1024 * 1024) return 24; 412 if (size <= 32 * 1024 * 1024) return 25; 413 414 if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 110000) 415 && !IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 416 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 417 else 418 BUG(); 419 420 /* Will never be reached. Needed because the compiler may complain */ 421 return -1; 422 } 423 #define kmalloc_index(s) __kmalloc_index(s, true) 424 #endif /* !CONFIG_SLOB */ 425 426 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 427 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc; 428 void kmem_cache_free(struct kmem_cache *s, void *objp); 429 430 /* 431 * Bulk allocation and freeing operations. These are accelerated in an 432 * allocator specific way to avoid taking locks repeatedly or building 433 * metadata structures unnecessarily. 434 * 435 * Note that interrupts must be enabled when calling these functions. 436 */ 437 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 438 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 439 440 /* 441 * Caller must not use kfree_bulk() on memory not originally allocated 442 * by kmalloc(), because the SLOB allocator cannot handle this. 443 */ 444 static __always_inline void kfree_bulk(size_t size, void **p) 445 { 446 kmem_cache_free_bulk(NULL, size, p); 447 } 448 449 #ifdef CONFIG_NUMA 450 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 451 __alloc_size(1); 452 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 453 __malloc; 454 #else 455 static __always_inline __alloc_size(1) void *__kmalloc_node(size_t size, gfp_t flags, int node) 456 { 457 return __kmalloc(size, flags); 458 } 459 460 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 461 { 462 return kmem_cache_alloc(s, flags); 463 } 464 #endif 465 466 #ifdef CONFIG_TRACING 467 extern void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 468 __assume_slab_alignment __alloc_size(3); 469 470 #ifdef CONFIG_NUMA 471 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 472 int node, size_t size) __assume_slab_alignment 473 __alloc_size(4); 474 #else 475 static __always_inline __alloc_size(4) void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 476 gfp_t gfpflags, int node, size_t size) 477 { 478 return kmem_cache_alloc_trace(s, gfpflags, size); 479 } 480 #endif /* CONFIG_NUMA */ 481 482 #else /* CONFIG_TRACING */ 483 static __always_inline __alloc_size(3) void *kmem_cache_alloc_trace(struct kmem_cache *s, 484 gfp_t flags, size_t size) 485 { 486 void *ret = kmem_cache_alloc(s, flags); 487 488 ret = kasan_kmalloc(s, ret, size, flags); 489 return ret; 490 } 491 492 static __always_inline void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 493 int node, size_t size) 494 { 495 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 496 497 ret = kasan_kmalloc(s, ret, size, gfpflags); 498 return ret; 499 } 500 #endif /* CONFIG_TRACING */ 501 502 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment 503 __alloc_size(1); 504 505 #ifdef CONFIG_TRACING 506 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 507 __assume_page_alignment __alloc_size(1); 508 #else 509 static __always_inline __alloc_size(1) void *kmalloc_order_trace(size_t size, gfp_t flags, 510 unsigned int order) 511 { 512 return kmalloc_order(size, flags, order); 513 } 514 #endif 515 516 static __always_inline __alloc_size(1) void *kmalloc_large(size_t size, gfp_t flags) 517 { 518 unsigned int order = get_order(size); 519 return kmalloc_order_trace(size, flags, order); 520 } 521 522 /** 523 * kmalloc - allocate memory 524 * @size: how many bytes of memory are required. 525 * @flags: the type of memory to allocate. 526 * 527 * kmalloc is the normal method of allocating memory 528 * for objects smaller than page size in the kernel. 529 * 530 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 531 * bytes. For @size of power of two bytes, the alignment is also guaranteed 532 * to be at least to the size. 533 * 534 * The @flags argument may be one of the GFP flags defined at 535 * include/linux/gfp.h and described at 536 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 537 * 538 * The recommended usage of the @flags is described at 539 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 540 * 541 * Below is a brief outline of the most useful GFP flags 542 * 543 * %GFP_KERNEL 544 * Allocate normal kernel ram. May sleep. 545 * 546 * %GFP_NOWAIT 547 * Allocation will not sleep. 548 * 549 * %GFP_ATOMIC 550 * Allocation will not sleep. May use emergency pools. 551 * 552 * %GFP_HIGHUSER 553 * Allocate memory from high memory on behalf of user. 554 * 555 * Also it is possible to set different flags by OR'ing 556 * in one or more of the following additional @flags: 557 * 558 * %__GFP_HIGH 559 * This allocation has high priority and may use emergency pools. 560 * 561 * %__GFP_NOFAIL 562 * Indicate that this allocation is in no way allowed to fail 563 * (think twice before using). 564 * 565 * %__GFP_NORETRY 566 * If memory is not immediately available, 567 * then give up at once. 568 * 569 * %__GFP_NOWARN 570 * If allocation fails, don't issue any warnings. 571 * 572 * %__GFP_RETRY_MAYFAIL 573 * Try really hard to succeed the allocation but fail 574 * eventually. 575 */ 576 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 577 { 578 if (__builtin_constant_p(size)) { 579 #ifndef CONFIG_SLOB 580 unsigned int index; 581 #endif 582 if (size > KMALLOC_MAX_CACHE_SIZE) 583 return kmalloc_large(size, flags); 584 #ifndef CONFIG_SLOB 585 index = kmalloc_index(size); 586 587 if (!index) 588 return ZERO_SIZE_PTR; 589 590 return kmem_cache_alloc_trace( 591 kmalloc_caches[kmalloc_type(flags)][index], 592 flags, size); 593 #endif 594 } 595 return __kmalloc(size, flags); 596 } 597 598 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 599 { 600 #ifndef CONFIG_SLOB 601 if (__builtin_constant_p(size) && 602 size <= KMALLOC_MAX_CACHE_SIZE) { 603 unsigned int i = kmalloc_index(size); 604 605 if (!i) 606 return ZERO_SIZE_PTR; 607 608 return kmem_cache_alloc_node_trace( 609 kmalloc_caches[kmalloc_type(flags)][i], 610 flags, node, size); 611 } 612 #endif 613 return __kmalloc_node(size, flags, node); 614 } 615 616 /** 617 * kmalloc_array - allocate memory for an array. 618 * @n: number of elements. 619 * @size: element size. 620 * @flags: the type of memory to allocate (see kmalloc). 621 */ 622 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) 623 { 624 size_t bytes; 625 626 if (unlikely(check_mul_overflow(n, size, &bytes))) 627 return NULL; 628 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 629 return kmalloc(bytes, flags); 630 return __kmalloc(bytes, flags); 631 } 632 633 /** 634 * krealloc_array - reallocate memory for an array. 635 * @p: pointer to the memory chunk to reallocate 636 * @new_n: new number of elements to alloc 637 * @new_size: new size of a single member of the array 638 * @flags: the type of memory to allocate (see kmalloc) 639 */ 640 static inline __alloc_size(2, 3) void * __must_check krealloc_array(void *p, 641 size_t new_n, 642 size_t new_size, 643 gfp_t flags) 644 { 645 size_t bytes; 646 647 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 648 return NULL; 649 650 return krealloc(p, bytes, flags); 651 } 652 653 /** 654 * kcalloc - allocate memory for an array. The memory is set to zero. 655 * @n: number of elements. 656 * @size: element size. 657 * @flags: the type of memory to allocate (see kmalloc). 658 */ 659 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 660 { 661 return kmalloc_array(n, size, flags | __GFP_ZERO); 662 } 663 664 /* 665 * kmalloc_track_caller is a special version of kmalloc that records the 666 * calling function of the routine calling it for slab leak tracking instead 667 * of just the calling function (confusing, eh?). 668 * It's useful when the call to kmalloc comes from a widely-used standard 669 * allocator where we care about the real place the memory allocation 670 * request comes from. 671 */ 672 extern void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) 673 __alloc_size(1); 674 #define kmalloc_track_caller(size, flags) \ 675 __kmalloc_track_caller(size, flags, _RET_IP_) 676 677 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 678 int node) 679 { 680 size_t bytes; 681 682 if (unlikely(check_mul_overflow(n, size, &bytes))) 683 return NULL; 684 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 685 return kmalloc_node(bytes, flags, node); 686 return __kmalloc_node(bytes, flags, node); 687 } 688 689 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 690 { 691 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 692 } 693 694 695 #ifdef CONFIG_NUMA 696 extern void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 697 unsigned long caller) __alloc_size(1); 698 #define kmalloc_node_track_caller(size, flags, node) \ 699 __kmalloc_node_track_caller(size, flags, node, \ 700 _RET_IP_) 701 702 #else /* CONFIG_NUMA */ 703 704 #define kmalloc_node_track_caller(size, flags, node) \ 705 kmalloc_track_caller(size, flags) 706 707 #endif /* CONFIG_NUMA */ 708 709 /* 710 * Shortcuts 711 */ 712 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 713 { 714 return kmem_cache_alloc(k, flags | __GFP_ZERO); 715 } 716 717 /** 718 * kzalloc - allocate memory. The memory is set to zero. 719 * @size: how many bytes of memory are required. 720 * @flags: the type of memory to allocate (see kmalloc). 721 */ 722 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 723 { 724 return kmalloc(size, flags | __GFP_ZERO); 725 } 726 727 /** 728 * kzalloc_node - allocate zeroed memory from a particular memory node. 729 * @size: how many bytes of memory are required. 730 * @flags: the type of memory to allocate (see kmalloc). 731 * @node: memory node from which to allocate 732 */ 733 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 734 { 735 return kmalloc_node(size, flags | __GFP_ZERO, node); 736 } 737 738 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 739 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 740 { 741 return kvmalloc_node(size, flags, NUMA_NO_NODE); 742 } 743 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 744 { 745 return kvmalloc_node(size, flags | __GFP_ZERO, node); 746 } 747 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 748 { 749 return kvmalloc(size, flags | __GFP_ZERO); 750 } 751 752 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 753 { 754 size_t bytes; 755 756 if (unlikely(check_mul_overflow(n, size, &bytes))) 757 return NULL; 758 759 return kvmalloc(bytes, flags); 760 } 761 762 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 763 { 764 return kvmalloc_array(n, size, flags | __GFP_ZERO); 765 } 766 767 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 768 __alloc_size(3); 769 extern void kvfree(const void *addr); 770 extern void kvfree_sensitive(const void *addr, size_t len); 771 772 unsigned int kmem_cache_size(struct kmem_cache *s); 773 void __init kmem_cache_init_late(void); 774 775 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 776 int slab_prepare_cpu(unsigned int cpu); 777 int slab_dead_cpu(unsigned int cpu); 778 #else 779 #define slab_prepare_cpu NULL 780 #define slab_dead_cpu NULL 781 #endif 782 783 #endif /* _LINUX_SLAB_H */ 784