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 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 *); 156 int kmem_cache_shrink(struct kmem_cache *); 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 *, size_t, gfp_t); 185 void kfree(const void *); 186 void kfree_sensitive(const void *); 187 size_t __ksize(const void *); 188 size_t ksize(const void *); 189 190 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 191 void __check_heap_object(const void *ptr, unsigned long n, struct page *page, 192 bool to_user); 193 #else 194 static inline void __check_heap_object(const void *ptr, unsigned long n, 195 struct page *page, bool to_user) { } 196 #endif 197 198 /* 199 * Some archs want to perform DMA into kmalloc caches and need a guaranteed 200 * alignment larger than the alignment of a 64-bit integer. 201 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. 202 */ 203 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 204 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN 205 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN 206 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) 207 #else 208 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) 209 #endif 210 211 /* 212 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. 213 * Intended for arches that get misalignment faults even for 64 bit integer 214 * aligned buffers. 215 */ 216 #ifndef ARCH_SLAB_MINALIGN 217 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) 218 #endif 219 220 /* 221 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned 222 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN 223 * aligned pointers. 224 */ 225 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) 226 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) 227 #define __assume_page_alignment __assume_aligned(PAGE_SIZE) 228 229 /* 230 * Kmalloc array related definitions 231 */ 232 233 #ifdef CONFIG_SLAB 234 /* 235 * The largest kmalloc size supported by the SLAB allocators is 236 * 32 megabyte (2^25) or the maximum allocatable page order if that is 237 * less than 32 MB. 238 * 239 * WARNING: Its not easy to increase this value since the allocators have 240 * to do various tricks to work around compiler limitations in order to 241 * ensure proper constant folding. 242 */ 243 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 244 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 245 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH 246 #ifndef KMALLOC_SHIFT_LOW 247 #define KMALLOC_SHIFT_LOW 5 248 #endif 249 #endif 250 251 #ifdef CONFIG_SLUB 252 /* 253 * SLUB directly allocates requests fitting in to an order-1 page 254 * (PAGE_SIZE*2). Larger requests are passed to the page allocator. 255 */ 256 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) 257 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 258 #ifndef KMALLOC_SHIFT_LOW 259 #define KMALLOC_SHIFT_LOW 3 260 #endif 261 #endif 262 263 #ifdef CONFIG_SLOB 264 /* 265 * SLOB passes all requests larger than one page to the page allocator. 266 * No kmalloc array is necessary since objects of different sizes can 267 * be allocated from the same page. 268 */ 269 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT 270 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) 271 #ifndef KMALLOC_SHIFT_LOW 272 #define KMALLOC_SHIFT_LOW 3 273 #endif 274 #endif 275 276 /* Maximum allocatable size */ 277 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) 278 /* Maximum size for which we actually use a slab cache */ 279 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) 280 /* Maximum order allocatable via the slab allocator */ 281 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) 282 283 /* 284 * Kmalloc subsystem. 285 */ 286 #ifndef KMALLOC_MIN_SIZE 287 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) 288 #endif 289 290 /* 291 * This restriction comes from byte sized index implementation. 292 * Page size is normally 2^12 bytes and, in this case, if we want to use 293 * byte sized index which can represent 2^8 entries, the size of the object 294 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. 295 * If minimum size of kmalloc is less than 16, we use it as minimum object 296 * size and give up to use byte sized index. 297 */ 298 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ 299 (KMALLOC_MIN_SIZE) : 16) 300 301 /* 302 * Whenever changing this, take care of that kmalloc_type() and 303 * create_kmalloc_caches() still work as intended. 304 */ 305 enum kmalloc_cache_type { 306 KMALLOC_NORMAL = 0, 307 KMALLOC_RECLAIM, 308 #ifdef CONFIG_ZONE_DMA 309 KMALLOC_DMA, 310 #endif 311 NR_KMALLOC_TYPES 312 }; 313 314 #ifndef CONFIG_SLOB 315 extern struct kmem_cache * 316 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; 317 318 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) 319 { 320 #ifdef CONFIG_ZONE_DMA 321 /* 322 * The most common case is KMALLOC_NORMAL, so test for it 323 * with a single branch for both flags. 324 */ 325 if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0)) 326 return KMALLOC_NORMAL; 327 328 /* 329 * At least one of the flags has to be set. If both are, __GFP_DMA 330 * is more important. 331 */ 332 return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM; 333 #else 334 return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL; 335 #endif 336 } 337 338 /* 339 * Figure out which kmalloc slab an allocation of a certain size 340 * belongs to. 341 * 0 = zero alloc 342 * 1 = 65 .. 96 bytes 343 * 2 = 129 .. 192 bytes 344 * n = 2^(n-1)+1 .. 2^n 345 */ 346 static __always_inline unsigned int kmalloc_index(size_t size) 347 { 348 if (!size) 349 return 0; 350 351 if (size <= KMALLOC_MIN_SIZE) 352 return KMALLOC_SHIFT_LOW; 353 354 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) 355 return 1; 356 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) 357 return 2; 358 if (size <= 8) return 3; 359 if (size <= 16) return 4; 360 if (size <= 32) return 5; 361 if (size <= 64) return 6; 362 if (size <= 128) return 7; 363 if (size <= 256) return 8; 364 if (size <= 512) return 9; 365 if (size <= 1024) return 10; 366 if (size <= 2 * 1024) return 11; 367 if (size <= 4 * 1024) return 12; 368 if (size <= 8 * 1024) return 13; 369 if (size <= 16 * 1024) return 14; 370 if (size <= 32 * 1024) return 15; 371 if (size <= 64 * 1024) return 16; 372 if (size <= 128 * 1024) return 17; 373 if (size <= 256 * 1024) return 18; 374 if (size <= 512 * 1024) return 19; 375 if (size <= 1024 * 1024) return 20; 376 if (size <= 2 * 1024 * 1024) return 21; 377 if (size <= 4 * 1024 * 1024) return 22; 378 if (size <= 8 * 1024 * 1024) return 23; 379 if (size <= 16 * 1024 * 1024) return 24; 380 if (size <= 32 * 1024 * 1024) return 25; 381 if (size <= 64 * 1024 * 1024) return 26; 382 BUG(); 383 384 /* Will never be reached. Needed because the compiler may complain */ 385 return -1; 386 } 387 #endif /* !CONFIG_SLOB */ 388 389 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc; 390 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc; 391 void kmem_cache_free(struct kmem_cache *, void *); 392 393 /* 394 * Bulk allocation and freeing operations. These are accelerated in an 395 * allocator specific way to avoid taking locks repeatedly or building 396 * metadata structures unnecessarily. 397 * 398 * Note that interrupts must be enabled when calling these functions. 399 */ 400 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 401 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 402 403 /* 404 * Caller must not use kfree_bulk() on memory not originally allocated 405 * by kmalloc(), because the SLOB allocator cannot handle this. 406 */ 407 static __always_inline void kfree_bulk(size_t size, void **p) 408 { 409 kmem_cache_free_bulk(NULL, size, p); 410 } 411 412 #ifdef CONFIG_NUMA 413 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc; 414 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc; 415 #else 416 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node) 417 { 418 return __kmalloc(size, flags); 419 } 420 421 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) 422 { 423 return kmem_cache_alloc(s, flags); 424 } 425 #endif 426 427 #ifdef CONFIG_TRACING 428 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc; 429 430 #ifdef CONFIG_NUMA 431 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 432 gfp_t gfpflags, 433 int node, size_t size) __assume_slab_alignment __malloc; 434 #else 435 static __always_inline void * 436 kmem_cache_alloc_node_trace(struct kmem_cache *s, 437 gfp_t gfpflags, 438 int node, size_t size) 439 { 440 return kmem_cache_alloc_trace(s, gfpflags, size); 441 } 442 #endif /* CONFIG_NUMA */ 443 444 #else /* CONFIG_TRACING */ 445 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s, 446 gfp_t flags, size_t size) 447 { 448 void *ret = kmem_cache_alloc(s, flags); 449 450 ret = kasan_kmalloc(s, ret, size, flags); 451 return ret; 452 } 453 454 static __always_inline void * 455 kmem_cache_alloc_node_trace(struct kmem_cache *s, 456 gfp_t gfpflags, 457 int node, size_t size) 458 { 459 void *ret = kmem_cache_alloc_node(s, gfpflags, node); 460 461 ret = kasan_kmalloc(s, ret, size, gfpflags); 462 return ret; 463 } 464 #endif /* CONFIG_TRACING */ 465 466 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 467 468 #ifdef CONFIG_TRACING 469 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; 470 #else 471 static __always_inline void * 472 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) 473 { 474 return kmalloc_order(size, flags, order); 475 } 476 #endif 477 478 static __always_inline void *kmalloc_large(size_t size, gfp_t flags) 479 { 480 unsigned int order = get_order(size); 481 return kmalloc_order_trace(size, flags, order); 482 } 483 484 /** 485 * kmalloc - allocate memory 486 * @size: how many bytes of memory are required. 487 * @flags: the type of memory to allocate. 488 * 489 * kmalloc is the normal method of allocating memory 490 * for objects smaller than page size in the kernel. 491 * 492 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN 493 * bytes. For @size of power of two bytes, the alignment is also guaranteed 494 * to be at least to the size. 495 * 496 * The @flags argument may be one of the GFP flags defined at 497 * include/linux/gfp.h and described at 498 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` 499 * 500 * The recommended usage of the @flags is described at 501 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` 502 * 503 * Below is a brief outline of the most useful GFP flags 504 * 505 * %GFP_KERNEL 506 * Allocate normal kernel ram. May sleep. 507 * 508 * %GFP_NOWAIT 509 * Allocation will not sleep. 510 * 511 * %GFP_ATOMIC 512 * Allocation will not sleep. May use emergency pools. 513 * 514 * %GFP_HIGHUSER 515 * Allocate memory from high memory on behalf of user. 516 * 517 * Also it is possible to set different flags by OR'ing 518 * in one or more of the following additional @flags: 519 * 520 * %__GFP_HIGH 521 * This allocation has high priority and may use emergency pools. 522 * 523 * %__GFP_NOFAIL 524 * Indicate that this allocation is in no way allowed to fail 525 * (think twice before using). 526 * 527 * %__GFP_NORETRY 528 * If memory is not immediately available, 529 * then give up at once. 530 * 531 * %__GFP_NOWARN 532 * If allocation fails, don't issue any warnings. 533 * 534 * %__GFP_RETRY_MAYFAIL 535 * Try really hard to succeed the allocation but fail 536 * eventually. 537 */ 538 static __always_inline void *kmalloc(size_t size, gfp_t flags) 539 { 540 if (__builtin_constant_p(size)) { 541 #ifndef CONFIG_SLOB 542 unsigned int index; 543 #endif 544 if (size > KMALLOC_MAX_CACHE_SIZE) 545 return kmalloc_large(size, flags); 546 #ifndef CONFIG_SLOB 547 index = kmalloc_index(size); 548 549 if (!index) 550 return ZERO_SIZE_PTR; 551 552 return kmem_cache_alloc_trace( 553 kmalloc_caches[kmalloc_type(flags)][index], 554 flags, size); 555 #endif 556 } 557 return __kmalloc(size, flags); 558 } 559 560 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) 561 { 562 #ifndef CONFIG_SLOB 563 if (__builtin_constant_p(size) && 564 size <= KMALLOC_MAX_CACHE_SIZE) { 565 unsigned int i = kmalloc_index(size); 566 567 if (!i) 568 return ZERO_SIZE_PTR; 569 570 return kmem_cache_alloc_node_trace( 571 kmalloc_caches[kmalloc_type(flags)][i], 572 flags, node, size); 573 } 574 #endif 575 return __kmalloc_node(size, flags, node); 576 } 577 578 /** 579 * kmalloc_array - allocate memory for an array. 580 * @n: number of elements. 581 * @size: element size. 582 * @flags: the type of memory to allocate (see kmalloc). 583 */ 584 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) 585 { 586 size_t bytes; 587 588 if (unlikely(check_mul_overflow(n, size, &bytes))) 589 return NULL; 590 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 591 return kmalloc(bytes, flags); 592 return __kmalloc(bytes, flags); 593 } 594 595 /** 596 * kcalloc - allocate memory for an array. The memory is set to zero. 597 * @n: number of elements. 598 * @size: element size. 599 * @flags: the type of memory to allocate (see kmalloc). 600 */ 601 static inline void *kcalloc(size_t n, size_t size, gfp_t flags) 602 { 603 return kmalloc_array(n, size, flags | __GFP_ZERO); 604 } 605 606 /* 607 * kmalloc_track_caller is a special version of kmalloc that records the 608 * calling function of the routine calling it for slab leak tracking instead 609 * of just the calling function (confusing, eh?). 610 * It's useful when the call to kmalloc comes from a widely-used standard 611 * allocator where we care about the real place the memory allocation 612 * request comes from. 613 */ 614 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long); 615 #define kmalloc_track_caller(size, flags) \ 616 __kmalloc_track_caller(size, flags, _RET_IP_) 617 618 static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, 619 int node) 620 { 621 size_t bytes; 622 623 if (unlikely(check_mul_overflow(n, size, &bytes))) 624 return NULL; 625 if (__builtin_constant_p(n) && __builtin_constant_p(size)) 626 return kmalloc_node(bytes, flags, node); 627 return __kmalloc_node(bytes, flags, node); 628 } 629 630 static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) 631 { 632 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); 633 } 634 635 636 #ifdef CONFIG_NUMA 637 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long); 638 #define kmalloc_node_track_caller(size, flags, node) \ 639 __kmalloc_node_track_caller(size, flags, node, \ 640 _RET_IP_) 641 642 #else /* CONFIG_NUMA */ 643 644 #define kmalloc_node_track_caller(size, flags, node) \ 645 kmalloc_track_caller(size, flags) 646 647 #endif /* CONFIG_NUMA */ 648 649 /* 650 * Shortcuts 651 */ 652 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 653 { 654 return kmem_cache_alloc(k, flags | __GFP_ZERO); 655 } 656 657 /** 658 * kzalloc - allocate memory. The memory is set to zero. 659 * @size: how many bytes of memory are required. 660 * @flags: the type of memory to allocate (see kmalloc). 661 */ 662 static inline void *kzalloc(size_t size, gfp_t flags) 663 { 664 return kmalloc(size, flags | __GFP_ZERO); 665 } 666 667 /** 668 * kzalloc_node - allocate zeroed memory from a particular memory node. 669 * @size: how many bytes of memory are required. 670 * @flags: the type of memory to allocate (see kmalloc). 671 * @node: memory node from which to allocate 672 */ 673 static inline void *kzalloc_node(size_t size, gfp_t flags, int node) 674 { 675 return kmalloc_node(size, flags | __GFP_ZERO, node); 676 } 677 678 unsigned int kmem_cache_size(struct kmem_cache *s); 679 void __init kmem_cache_init_late(void); 680 681 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) 682 int slab_prepare_cpu(unsigned int cpu); 683 int slab_dead_cpu(unsigned int cpu); 684 #else 685 #define slab_prepare_cpu NULL 686 #define slab_dead_cpu NULL 687 #endif 688 689 #endif /* _LINUX_SLAB_H */ 690