1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). 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 /* 193 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 194 * alignment larger than the alignment of a 64-bit integer. 195 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. 196 */ 197 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 198 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 199 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 200 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 201 #else 202 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 203 #endif 204 205 /* 206 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 207 * Intended for arches that get misalignment faults even for 64 bit integer 208 * aligned buffers. 209 */ 210 #ifndef ARCH_SLAB_MINALIGN 211 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 212 #endif 213 214 /* 215 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned 216 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN 217 * aligned pointers. 218 */ 219 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 220 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 221 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 222 223 /* 224 * Kmalloc array related definitions 225 */ 226 227 #ifdef CONFIG_SLAB 228 /* 229 * The largest kmalloc size supported by the SLAB allocators is 230 * 32 megabyte (2^25) or the maximum allocatable page order if that is 231 * less than 32 MB. 232 * 233 * WARNING: Its not easy to increase this value since the allocators have 234 * to do various tricks to work around compiler limitations in order to 235 * ensure proper constant folding. 236 */ 237 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 238 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 239 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 240 #ifndef KMALLOC_SHIFT_LOW 241 #define KMALLOC_SHIFT_LOW 5 242 #endif 243 #endif 244 245 #ifdef CONFIG_SLUB 246 /* 247 * SLUB directly allocates requests fitting in to an order-1 page 248 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 249 */ 250 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 251 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 252 #ifndef KMALLOC_SHIFT_LOW 253 #define KMALLOC_SHIFT_LOW 3 254 #endif 255 #endif 256 257 #ifdef CONFIG_SLOB 258 /* 259 * SLOB passes all requests larger than one page to the page allocator. 260 * No kmalloc array is necessary since objects of different sizes can 261 * be allocated from the same page. 262 */ 263 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 264 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 265 #ifndef KMALLOC_SHIFT_LOW 266 #define KMALLOC_SHIFT_LOW 3 267 #endif 268 #endif 269 270 /* Maximum allocatable size */ 271 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 272 /* Maximum size for which we actually use a slab cache */ 273 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 274 /* Maximum order allocatable via the slab allocator */ 275 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 276 277 /* 278 * Kmalloc subsystem. 279 */ 280 #ifndef KMALLOC_MIN_SIZE 281 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 282 #endif 283 284 /* 285 * This restriction comes from byte sized index implementation. 286 * Page size is normally 2^12 bytes and, in this case, if we want to use 287 * byte sized index which can represent 2^8 entries, the size of the object 288 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 289 * If minimum size of kmalloc is less than 16, we use it as minimum object 290 * size and give up to use byte sized index. 291 */ 292 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 293 (KMALLOC_MIN_SIZE) : 16) 294 295 /* 296 * Whenever changing this, take care of that kmalloc_type() and 297 * create_kmalloc_caches() still work as intended. 298 * 299 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP 300 * is for accounted but unreclaimable and non-dma objects. All the other 301 * kmem caches can have both accounted and unaccounted objects. 302 */ 303 enum kmalloc_cache_type { 304 KMALLOC_NORMAL = 0, 305 #ifndef CONFIG_ZONE_DMA 306 KMALLOC_DMA = KMALLOC_NORMAL, 307 #endif 308 #ifndef CONFIG_MEMCG_KMEM 309 KMALLOC_CGROUP = KMALLOC_NORMAL, 310 #else 311 KMALLOC_CGROUP, 312 #endif 313 KMALLOC_RECLAIM, 314 #ifdef CONFIG_ZONE_DMA 315 KMALLOC_DMA, 316 #endif 317 NR_KMALLOC_TYPES 318 }; 319 320 #ifndef CONFIG_SLOB 321 extern struct kmem_cache * 322 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 323 324 /* 325 * Define gfp bits that should not be set for KMALLOC_NORMAL. 326 */ 327 #define KMALLOC_NOT_NORMAL_BITS \ 328 (__GFP_RECLAIMABLE | \ 329 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ 330 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) 331 332 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 333 { 334 /* 335 * The most common case is KMALLOC_NORMAL, so test for it 336 * with a single branch for all the relevant flags. 337 */ 338 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) 339 return KMALLOC_NORMAL; 340 341 /* 342 * At least one of the flags has to be set. Their priorities in 343 * decreasing order are: 344 * 1) __GFP_DMA 345 * 2) __GFP_RECLAIMABLE 346 * 3) __GFP_ACCOUNT 347 */ 348 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) 349 return KMALLOC_DMA; 350 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) 351 return KMALLOC_RECLAIM; 352 else 353 return KMALLOC_CGROUP; 354 } 355 356 /* 357 * Figure out which kmalloc slab an allocation of a certain size 358 * belongs to. 359 * 0 = zero alloc 360 * 1 = 65 .. 96 bytes 361 * 2 = 129 .. 192 bytes 362 * n = 2^(n-1)+1 .. 2^n 363 * 364 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; 365 * typical usage is via kmalloc_index() and therefore evaluated at compile-time. 366 * Callers where !size_is_constant should only be test modules, where runtime 367 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). 368 */ 369 static __always_inline unsigned int __kmalloc_index(size_t size, 370 bool size_is_constant) 371 { 372 if (!size) 373 return 0; 374 375 if (size <= KMALLOC_MIN_SIZE) 376 return KMALLOC_SHIFT_LOW; 377 378 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 379 return 1; 380 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 381 return 2; 382 if (size <= 8) return 3; 383 if (size <= 16) return 4; 384 if (size <= 32) return 5; 385 if (size <= 64) return 6; 386 if (size <= 128) return 7; 387 if (size <= 256) return 8; 388 if (size <= 512) return 9; 389 if (size <= 1024) return 10; 390 if (size <= 2 * 1024) return 11; 391 if (size <= 4 * 1024) return 12; 392 if (size <= 8 * 1024) return 13; 393 if (size <= 16 * 1024) return 14; 394 if (size <= 32 * 1024) return 15; 395 if (size <= 64 * 1024) return 16; 396 if (size <= 128 * 1024) return 17; 397 if (size <= 256 * 1024) return 18; 398 if (size <= 512 * 1024) return 19; 399 if (size <= 1024 * 1024) return 20; 400 if (size <= 2 * 1024 * 1024) return 21; 401 if (size <= 4 * 1024 * 1024) return 22; 402 if (size <= 8 * 1024 * 1024) return 23; 403 if (size <= 16 * 1024 * 1024) return 24; 404 if (size <= 32 * 1024 * 1024) return 25; 405 406 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) 407 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); 408 else 409 BUG(); 410 411 /* Will never be reached. Needed because the compiler may complain */ 412 return -1; 413 } 414 #define kmalloc_index(s) __kmalloc_index(s, true) 415 #endif /* !CONFIG_SLOB */ 416 417 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); 418 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc; 419 void kmem_cache_free(struct kmem_cache *s, void *objp); 420 421 /* 422 * Bulk allocation and freeing operations. These are accelerated in an 423 * allocator specific way to avoid taking locks repeatedly or building 424 * metadata structures unnecessarily. 425 * 426 * Note that interrupts must be enabled when calling these functions. 427 */ 428 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); 429 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); 430 431 /* 432 * Caller must not use kfree_bulk() on memory not originally allocated 433 * by kmalloc(), because the SLOB allocator cannot handle this. 434 */ 435 static __always_inline void kfree_bulk(size_t size, void **p) 436 { 437 kmem_cache_free_bulk(NULL, size, p); 438 } 439 440 #ifdef CONFIG_NUMA 441 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment 442 __alloc_size(1); 443 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment 444 __malloc; 445 #else 446 static __always_inline __alloc_size(1) void *__kmalloc_node(size_t size, gfp_t flags, int node) 447 { 448 return __kmalloc(size, flags); 449 } 450 451 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 452 { 453 return kmem_cache_alloc(s, flags); 454 } 455 #endif 456 457 #ifdef CONFIG_TRACING 458 extern void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) 459 __assume_slab_alignment __alloc_size(3); 460 461 #ifdef CONFIG_NUMA 462 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 463 int node, size_t size) __assume_slab_alignment 464 __alloc_size(4); 465 #else 466 static __always_inline __alloc_size(4) void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 467 gfp_t gfpflags, int node, size_t size) 468 { 469 return kmem_cache_alloc_trace(s, gfpflags, size); 470 } 471 #endif /* CONFIG_NUMA */ 472 473 #else /* CONFIG_TRACING */ 474 static __always_inline __alloc_size(3) void *kmem_cache_alloc_trace(struct kmem_cache *s, 475 gfp_t flags, size_t size) 476 { 477 void *ret = kmem_cache_alloc(s, flags); 478 479 ret = kasan_kmalloc(s, ret, size, flags); 480 return ret; 481 } 482 483 static __always_inline void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, 484 int node, size_t size) 485 { 486 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 487 488 ret = kasan_kmalloc(s, ret, size, gfpflags); 489 return ret; 490 } 491 #endif /* CONFIG_TRACING */ 492 493 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment 494 __alloc_size(1); 495 496 #ifdef CONFIG_TRACING 497 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 498 __assume_page_alignment __alloc_size(1); 499 #else 500 static __always_inline __alloc_size(1) void *kmalloc_order_trace(size_t size, gfp_t flags, 501 unsigned int order) 502 { 503 return kmalloc_order(size, flags, order); 504 } 505 #endif 506 507 static __always_inline __alloc_size(1) void *kmalloc_large(size_t size, gfp_t flags) 508 { 509 unsigned int order = get_order(size); 510 return kmalloc_order_trace(size, flags, order); 511 } 512 513 /** 514 * kmalloc - allocate memory 515 * @size: how many bytes of memory are required. 516 * @flags: the type of memory to allocate. 517 * 518 * kmalloc is the normal method of allocating memory 519 * for objects smaller than page size in the kernel. 520 * 521 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 522 * bytes. For @size of power of two bytes, the alignment is also guaranteed 523 * to be at least to the size. 524 * 525 * The @flags argument may be one of the GFP flags defined at 526 * include/linux/gfp.h and described at 527 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 528 * 529 * The recommended usage of the @flags is described at 530 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 531 * 532 * Below is a brief outline of the most useful GFP flags 533 * 534 * %GFP_KERNEL 535 * Allocate normal kernel ram. May sleep. 536 * 537 * %GFP_NOWAIT 538 * Allocation will not sleep. 539 * 540 * %GFP_ATOMIC 541 * Allocation will not sleep. May use emergency pools. 542 * 543 * %GFP_HIGHUSER 544 * Allocate memory from high memory on behalf of user. 545 * 546 * Also it is possible to set different flags by OR'ing 547 * in one or more of the following additional @flags: 548 * 549 * %__GFP_HIGH 550 * This allocation has high priority and may use emergency pools. 551 * 552 * %__GFP_NOFAIL 553 * Indicate that this allocation is in no way allowed to fail 554 * (think twice before using). 555 * 556 * %__GFP_NORETRY 557 * If memory is not immediately available, 558 * then give up at once. 559 * 560 * %__GFP_NOWARN 561 * If allocation fails, don't issue any warnings. 562 * 563 * %__GFP_RETRY_MAYFAIL 564 * Try really hard to succeed the allocation but fail 565 * eventually. 566 */ 567 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) 568 { 569 if (__builtin_constant_p(size)) { 570 #ifndef CONFIG_SLOB 571 unsigned int index; 572 #endif 573 if (size > KMALLOC_MAX_CACHE_SIZE) 574 return kmalloc_large(size, flags); 575 #ifndef CONFIG_SLOB 576 index = kmalloc_index(size); 577 578 if (!index) 579 return ZERO_SIZE_PTR; 580 581 return kmem_cache_alloc_trace( 582 kmalloc_caches[kmalloc_type(flags)][index], 583 flags, size); 584 #endif 585 } 586 return __kmalloc(size, flags); 587 } 588 589 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) 590 { 591 #ifndef CONFIG_SLOB 592 if (__builtin_constant_p(size) && 593 size <= KMALLOC_MAX_CACHE_SIZE) { 594 unsigned int i = kmalloc_index(size); 595 596 if (!i) 597 return ZERO_SIZE_PTR; 598 599 return kmem_cache_alloc_node_trace( 600 kmalloc_caches[kmalloc_type(flags)][i], 601 flags, node, size); 602 } 603 #endif 604 return __kmalloc_node(size, flags, node); 605 } 606 607 /** 608 * kmalloc_array - allocate memory for an array. 609 * @n: number of elements. 610 * @size: element size. 611 * @flags: the type of memory to allocate (see kmalloc). 612 */ 613 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) 614 { 615 size_t bytes; 616 617 if (unlikely(check_mul_overflow(n, size, &bytes))) 618 return NULL; 619 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 620 return kmalloc(bytes, flags); 621 return __kmalloc(bytes, flags); 622 } 623 624 /** 625 * krealloc_array - reallocate memory for an array. 626 * @p: pointer to the memory chunk to reallocate 627 * @new_n: new number of elements to alloc 628 * @new_size: new size of a single member of the array 629 * @flags: the type of memory to allocate (see kmalloc) 630 */ 631 static inline __alloc_size(2, 3) void * __must_check krealloc_array(void *p, 632 size_t new_n, 633 size_t new_size, 634 gfp_t flags) 635 { 636 size_t bytes; 637 638 if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) 639 return NULL; 640 641 return krealloc(p, bytes, flags); 642 } 643 644 /** 645 * kcalloc - allocate memory for an array. The memory is set to zero. 646 * @n: number of elements. 647 * @size: element size. 648 * @flags: the type of memory to allocate (see kmalloc). 649 */ 650 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) 651 { 652 return kmalloc_array(n, size, flags | __GFP_ZERO); 653 } 654 655 /* 656 * kmalloc_track_caller is a special version of kmalloc that records the 657 * calling function of the routine calling it for slab leak tracking instead 658 * of just the calling function (confusing, eh?). 659 * It's useful when the call to kmalloc comes from a widely-used standard 660 * allocator where we care about the real place the memory allocation 661 * request comes from. 662 */ 663 extern void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) 664 __alloc_size(1); 665 #define kmalloc_track_caller(size, flags) \ 666 __kmalloc_track_caller(size, flags, _RET_IP_) 667 668 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 669 int node) 670 { 671 size_t bytes; 672 673 if (unlikely(check_mul_overflow(n, size, &bytes))) 674 return NULL; 675 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 676 return kmalloc_node(bytes, flags, node); 677 return __kmalloc_node(bytes, flags, node); 678 } 679 680 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 681 { 682 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 683 } 684 685 686 #ifdef CONFIG_NUMA 687 extern void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, 688 unsigned long caller) __alloc_size(1); 689 #define kmalloc_node_track_caller(size, flags, node) \ 690 __kmalloc_node_track_caller(size, flags, node, \ 691 _RET_IP_) 692 693 #else /* CONFIG_NUMA */ 694 695 #define kmalloc_node_track_caller(size, flags, node) \ 696 kmalloc_track_caller(size, flags) 697 698 #endif /* CONFIG_NUMA */ 699 700 /* 701 * Shortcuts 702 */ 703 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 704 { 705 return kmem_cache_alloc(k, flags | __GFP_ZERO); 706 } 707 708 /** 709 * kzalloc - allocate memory. The memory is set to zero. 710 * @size: how many bytes of memory are required. 711 * @flags: the type of memory to allocate (see kmalloc). 712 */ 713 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) 714 { 715 return kmalloc(size, flags | __GFP_ZERO); 716 } 717 718 /** 719 * kzalloc_node - allocate zeroed memory from a particular memory node. 720 * @size: how many bytes of memory are required. 721 * @flags: the type of memory to allocate (see kmalloc). 722 * @node: memory node from which to allocate 723 */ 724 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) 725 { 726 return kmalloc_node(size, flags | __GFP_ZERO, node); 727 } 728 729 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); 730 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) 731 { 732 return kvmalloc_node(size, flags, NUMA_NO_NODE); 733 } 734 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) 735 { 736 return kvmalloc_node(size, flags | __GFP_ZERO, node); 737 } 738 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) 739 { 740 return kvmalloc(size, flags | __GFP_ZERO); 741 } 742 743 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) 744 { 745 size_t bytes; 746 747 if (unlikely(check_mul_overflow(n, size, &bytes))) 748 return NULL; 749 750 return kvmalloc(bytes, flags); 751 } 752 753 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) 754 { 755 return kvmalloc_array(n, size, flags | __GFP_ZERO); 756 } 757 758 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 759 __alloc_size(3); 760 extern void kvfree(const void *addr); 761 extern void kvfree_sensitive(const void *addr, size_t len); 762 763 unsigned int kmem_cache_size(struct kmem_cache *s); 764 void __init kmem_cache_init_late(void); 765 766 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 767 int slab_prepare_cpu(unsigned int cpu); 768 int slab_dead_cpu(unsigned int cpu); 769 #else 770 #define slab_prepare_cpu NULL 771 #define slab_dead_cpu NULL 772 #endif 773 774 #endif /* _LINUX_SLAB_H */ 775