1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
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
15 #include <linux/cache.h>
16 #include <linux/gfp.h>
17 #include <linux/overflow.h>
18 #include <linux/types.h>
19 #include <linux/workqueue.h>
20 #include <linux/percpu-refcount.h>
24 * Flags to pass to kmem_cache_create().
25 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
27 /* DEBUG: Perform (expensive) checks on alloc/free */
28 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U)
29 /* DEBUG: Red zone objs in a cache */
30 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U)
31 /* DEBUG: Poison objects */
32 #define SLAB_POISON ((slab_flags_t __force)0x00000800U)
33 /* Indicate a kmalloc slab */
34 #define SLAB_KMALLOC ((slab_flags_t __force)0x00001000U)
35 /* Align objs on cache lines */
36 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U)
37 /* Use GFP_DMA memory */
38 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U)
39 /* Use GFP_DMA32 memory */
40 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U)
41 /* DEBUG: Store the last owner for bug hunting */
42 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U)
43 /* Panic if kmem_cache_create() fails */
44 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U)
46 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
48 * This delays freeing the SLAB page by a grace period, it does _NOT_
49 * delay object freeing. This means that if you do kmem_cache_free()
50 * that memory location is free to be reused at any time. Thus it may
51 * be possible to see another object there in the same RCU grace period.
53 * This feature only ensures the memory location backing the object
54 * stays valid, the trick to using this is relying on an independent
55 * object validation pass. Something like:
59 * obj = lockless_lookup(key);
61 * if (!try_get_ref(obj)) // might fail for free objects
65 * if (obj->key != key) { // not the object we expected
73 * This is useful if we need to approach a kernel structure obliquely,
74 * from its address obtained without the usual locking. We can lock
75 * the structure to stabilize it and check it's still at the given address,
76 * only if we can be sure that the memory has not been meanwhile reused
77 * for some other kind of object (which our subsystem's lock might corrupt).
79 * rcu_read_lock before reading the address, then rcu_read_unlock after
80 * taking the spinlock within the structure expected at that address.
82 * Note that it is not possible to acquire a lock within a structure
83 * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference
84 * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages
85 * are not zeroed before being given to the slab, which means that any
86 * locks must be initialized after each and every kmem_struct_alloc().
87 * Alternatively, make the ctor passed to kmem_cache_create() initialize
88 * the locks at page-allocation time, as is done in __i915_request_ctor(),
89 * sighand_ctor(), and anon_vma_ctor(). Such a ctor permits readers
90 * to safely acquire those ctor-initialized locks under rcu_read_lock()
93 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
95 /* Defer freeing slabs to RCU */
96 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U)
97 /* Spread some memory over cpuset */
98 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U)
99 /* Trace allocations and frees */
100 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U)
102 /* Flag to prevent checks on free */
103 #ifdef CONFIG_DEBUG_OBJECTS
104 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U)
106 # define SLAB_DEBUG_OBJECTS 0
109 /* Avoid kmemleak tracing */
110 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U)
113 * Prevent merging with compatible kmem caches. This flag should be used
114 * cautiously. Valid use cases:
116 * - caches created for self-tests (e.g. kunit)
117 * - general caches created and used by a subsystem, only when a
118 * (subsystem-specific) debug option is enabled
119 * - performance critical caches, should be very rare and consulted with slab
120 * maintainers, and not used together with CONFIG_SLUB_TINY
122 #define SLAB_NO_MERGE ((slab_flags_t __force)0x01000000U)
124 /* Fault injection mark */
125 #ifdef CONFIG_FAILSLAB
126 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U)
128 # define SLAB_FAILSLAB 0
130 /* Account to memcg */
131 #ifdef CONFIG_MEMCG_KMEM
132 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U)
134 # define SLAB_ACCOUNT 0
137 #ifdef CONFIG_KASAN_GENERIC
138 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U)
144 * Ignore user specified debugging flags.
145 * Intended for caches created for self-tests so they have only flags
146 * specified in the code and other flags are ignored.
148 #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U)
151 #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U)
153 #define SLAB_SKIP_KFENCE 0
156 /* The following flags affect the page allocator grouping pages by mobility */
157 /* Objects are reclaimable */
158 #ifndef CONFIG_SLUB_TINY
159 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U)
161 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0)
163 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
166 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
168 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
170 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
171 * Both make kfree a no-op.
173 #define ZERO_SIZE_PTR ((void *)16)
175 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
176 (unsigned long)ZERO_SIZE_PTR)
178 #include <linux/kasan.h>
183 * struct kmem_cache related prototypes
185 bool slab_is_available(void);
187 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
188 unsigned int align, slab_flags_t flags,
189 void (*ctor)(void *));
190 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
191 unsigned int size, unsigned int align,
193 unsigned int useroffset, unsigned int usersize,
194 void (*ctor)(void *));
195 void kmem_cache_destroy(struct kmem_cache *s);
196 int kmem_cache_shrink(struct kmem_cache *s);
199 * Please use this macro to create slab caches. Simply specify the
200 * name of the structure and maybe some flags that are listed above.
202 * The alignment of the struct determines object alignment. If you
203 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
204 * then the objects will be properly aligned in SMP configurations.
206 #define KMEM_CACHE(__struct, __flags) \
207 kmem_cache_create(#__struct, sizeof(struct __struct), \
208 __alignof__(struct __struct), (__flags), NULL)
211 * To whitelist a single field for copying to/from usercopy, use this
212 * macro instead for KMEM_CACHE() above.
214 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
215 kmem_cache_create_usercopy(#__struct, \
216 sizeof(struct __struct), \
217 __alignof__(struct __struct), (__flags), \
218 offsetof(struct __struct, __field), \
219 sizeof_field(struct __struct, __field), NULL)
222 * Common kmalloc functions provided by all allocators
224 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2);
225 void kfree(const void *objp);
226 void kfree_sensitive(const void *objp);
227 size_t __ksize(const void *objp);
230 * ksize - Report actual allocation size of associated object
232 * @objp: Pointer returned from a prior kmalloc()-family allocation.
234 * This should not be used for writing beyond the originally requested
235 * allocation size. Either use krealloc() or round up the allocation size
236 * with kmalloc_size_roundup() prior to allocation. If this is used to
237 * access beyond the originally requested allocation size, UBSAN_BOUNDS
238 * and/or FORTIFY_SOURCE may trip, since they only know about the
239 * originally allocated size via the __alloc_size attribute.
241 size_t ksize(const void *objp);
244 bool kmem_valid_obj(void *object);
245 void kmem_dump_obj(void *object);
249 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
250 * alignment larger than the alignment of a 64-bit integer.
251 * Setting ARCH_DMA_MINALIGN in arch headers allows that.
253 #ifdef ARCH_HAS_DMA_MINALIGN
254 #if ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN)
255 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
259 #ifndef ARCH_KMALLOC_MINALIGN
260 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
261 #elif ARCH_KMALLOC_MINALIGN > 8
262 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
263 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
267 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
268 * Intended for arches that get misalignment faults even for 64 bit integer
271 #ifndef ARCH_SLAB_MINALIGN
272 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
276 * Arches can define this function if they want to decide the minimum slab
277 * alignment at runtime. The value returned by the function must be a power
278 * of two and >= ARCH_SLAB_MINALIGN.
280 #ifndef arch_slab_minalign
281 static inline unsigned int arch_slab_minalign(void)
283 return ARCH_SLAB_MINALIGN;
288 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN.
289 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN
290 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment.
292 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
293 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
294 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
297 * Kmalloc array related definitions
302 * SLAB and SLUB directly allocates requests fitting in to an order-1 page
303 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
305 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
306 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
307 #ifndef KMALLOC_SHIFT_LOW
308 #define KMALLOC_SHIFT_LOW 5
313 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
314 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
315 #ifndef KMALLOC_SHIFT_LOW
316 #define KMALLOC_SHIFT_LOW 3
320 /* Maximum allocatable size */
321 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
322 /* Maximum size for which we actually use a slab cache */
323 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
324 /* Maximum order allocatable via the slab allocator */
325 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
330 #ifndef KMALLOC_MIN_SIZE
331 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
335 * This restriction comes from byte sized index implementation.
336 * Page size is normally 2^12 bytes and, in this case, if we want to use
337 * byte sized index which can represent 2^8 entries, the size of the object
338 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
339 * If minimum size of kmalloc is less than 16, we use it as minimum object
340 * size and give up to use byte sized index.
342 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
343 (KMALLOC_MIN_SIZE) : 16)
346 * Whenever changing this, take care of that kmalloc_type() and
347 * create_kmalloc_caches() still work as intended.
349 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP
350 * is for accounted but unreclaimable and non-dma objects. All the other
351 * kmem caches can have both accounted and unaccounted objects.
353 enum kmalloc_cache_type {
355 #ifndef CONFIG_ZONE_DMA
356 KMALLOC_DMA = KMALLOC_NORMAL,
358 #ifndef CONFIG_MEMCG_KMEM
359 KMALLOC_CGROUP = KMALLOC_NORMAL,
361 #ifdef CONFIG_SLUB_TINY
362 KMALLOC_RECLAIM = KMALLOC_NORMAL,
366 #ifdef CONFIG_ZONE_DMA
369 #ifdef CONFIG_MEMCG_KMEM
375 extern struct kmem_cache *
376 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
379 * Define gfp bits that should not be set for KMALLOC_NORMAL.
381 #define KMALLOC_NOT_NORMAL_BITS \
382 (__GFP_RECLAIMABLE | \
383 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \
384 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0))
386 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
389 * The most common case is KMALLOC_NORMAL, so test for it
390 * with a single branch for all the relevant flags.
392 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0))
393 return KMALLOC_NORMAL;
396 * At least one of the flags has to be set. Their priorities in
397 * decreasing order are:
399 * 2) __GFP_RECLAIMABLE
402 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
404 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE))
405 return KMALLOC_RECLAIM;
407 return KMALLOC_CGROUP;
411 * Figure out which kmalloc slab an allocation of a certain size
415 * 2 = 129 .. 192 bytes
416 * n = 2^(n-1)+1 .. 2^n
418 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
419 * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
420 * Callers where !size_is_constant should only be test modules, where runtime
421 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab().
423 static __always_inline unsigned int __kmalloc_index(size_t size,
424 bool size_is_constant)
429 if (size <= KMALLOC_MIN_SIZE)
430 return KMALLOC_SHIFT_LOW;
432 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
434 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
436 if (size <= 8) return 3;
437 if (size <= 16) return 4;
438 if (size <= 32) return 5;
439 if (size <= 64) return 6;
440 if (size <= 128) return 7;
441 if (size <= 256) return 8;
442 if (size <= 512) return 9;
443 if (size <= 1024) return 10;
444 if (size <= 2 * 1024) return 11;
445 if (size <= 4 * 1024) return 12;
446 if (size <= 8 * 1024) return 13;
447 if (size <= 16 * 1024) return 14;
448 if (size <= 32 * 1024) return 15;
449 if (size <= 64 * 1024) return 16;
450 if (size <= 128 * 1024) return 17;
451 if (size <= 256 * 1024) return 18;
452 if (size <= 512 * 1024) return 19;
453 if (size <= 1024 * 1024) return 20;
454 if (size <= 2 * 1024 * 1024) return 21;
456 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
457 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
461 /* Will never be reached. Needed because the compiler may complain */
464 static_assert(PAGE_SHIFT <= 20);
465 #define kmalloc_index(s) __kmalloc_index(s, true)
467 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
470 * kmem_cache_alloc - Allocate an object
471 * @cachep: The cache to allocate from.
472 * @flags: See kmalloc().
474 * Allocate an object from this cache.
475 * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags.
477 * Return: pointer to the new object or %NULL in case of error
479 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) __assume_slab_alignment __malloc;
480 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
481 gfp_t gfpflags) __assume_slab_alignment __malloc;
482 void kmem_cache_free(struct kmem_cache *s, void *objp);
485 * Bulk allocation and freeing operations. These are accelerated in an
486 * allocator specific way to avoid taking locks repeatedly or building
487 * metadata structures unnecessarily.
489 * Note that interrupts must be enabled when calling these functions.
491 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
492 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p);
494 static __always_inline void kfree_bulk(size_t size, void **p)
496 kmem_cache_free_bulk(NULL, size, p);
499 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
501 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment
504 void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size)
505 __assume_kmalloc_alignment __alloc_size(3);
507 void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
508 int node, size_t size) __assume_kmalloc_alignment
510 void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment
513 void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment
517 * kmalloc - allocate kernel memory
518 * @size: how many bytes of memory are required.
519 * @flags: describe the allocation context
521 * kmalloc is the normal method of allocating memory
522 * for objects smaller than page size in the kernel.
524 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN
525 * bytes. For @size of power of two bytes, the alignment is also guaranteed
526 * to be at least to the size.
528 * The @flags argument may be one of the GFP flags defined at
529 * include/linux/gfp_types.h and described at
530 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
532 * The recommended usage of the @flags is described at
533 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>`
535 * Below is a brief outline of the most useful GFP flags
538 * Allocate normal kernel ram. May sleep.
541 * Allocation will not sleep.
544 * Allocation will not sleep. May use emergency pools.
546 * Also it is possible to set different flags by OR'ing
547 * in one or more of the following additional @flags:
550 * Zero the allocated memory before returning. Also see kzalloc().
553 * This allocation has high priority and may use emergency pools.
556 * Indicate that this allocation is in no way allowed to fail
557 * (think twice before using).
560 * If memory is not immediately available,
561 * then give up at once.
564 * If allocation fails, don't issue any warnings.
566 * %__GFP_RETRY_MAYFAIL
567 * Try really hard to succeed the allocation but fail
570 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
572 if (__builtin_constant_p(size) && size) {
575 if (size > KMALLOC_MAX_CACHE_SIZE)
576 return kmalloc_large(size, flags);
578 index = kmalloc_index(size);
579 return kmalloc_trace(
580 kmalloc_caches[kmalloc_type(flags)][index],
583 return __kmalloc(size, flags);
586 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
588 if (__builtin_constant_p(size) && size) {
591 if (size > KMALLOC_MAX_CACHE_SIZE)
592 return kmalloc_large_node(size, flags, node);
594 index = kmalloc_index(size);
595 return kmalloc_node_trace(
596 kmalloc_caches[kmalloc_type(flags)][index],
599 return __kmalloc_node(size, flags, node);
603 * kmalloc_array - allocate memory for an array.
604 * @n: number of elements.
605 * @size: element size.
606 * @flags: the type of memory to allocate (see kmalloc).
608 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags)
612 if (unlikely(check_mul_overflow(n, size, &bytes)))
614 if (__builtin_constant_p(n) && __builtin_constant_p(size))
615 return kmalloc(bytes, flags);
616 return __kmalloc(bytes, flags);
620 * krealloc_array - reallocate memory for an array.
621 * @p: pointer to the memory chunk to reallocate
622 * @new_n: new number of elements to alloc
623 * @new_size: new size of a single member of the array
624 * @flags: the type of memory to allocate (see kmalloc)
626 static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p,
633 if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
636 return krealloc(p, bytes, flags);
640 * kcalloc - allocate memory for an array. The memory is set to zero.
641 * @n: number of elements.
642 * @size: element size.
643 * @flags: the type of memory to allocate (see kmalloc).
645 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags)
647 return kmalloc_array(n, size, flags | __GFP_ZERO);
650 void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node,
651 unsigned long caller) __alloc_size(1);
652 #define kmalloc_node_track_caller(size, flags, node) \
653 __kmalloc_node_track_caller(size, flags, node, \
657 * kmalloc_track_caller is a special version of kmalloc that records the
658 * calling function of the routine calling it for slab leak tracking instead
659 * of just the calling function (confusing, eh?).
660 * It's useful when the call to kmalloc comes from a widely-used standard
661 * allocator where we care about the real place the memory allocation
662 * request comes from.
664 #define kmalloc_track_caller(size, flags) \
665 __kmalloc_node_track_caller(size, flags, \
666 NUMA_NO_NODE, _RET_IP_)
668 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
673 if (unlikely(check_mul_overflow(n, size, &bytes)))
675 if (__builtin_constant_p(n) && __builtin_constant_p(size))
676 return kmalloc_node(bytes, flags, node);
677 return __kmalloc_node(bytes, flags, node);
680 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
682 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
688 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
690 return kmem_cache_alloc(k, flags | __GFP_ZERO);
694 * kzalloc - allocate memory. The memory is set to zero.
695 * @size: how many bytes of memory are required.
696 * @flags: the type of memory to allocate (see kmalloc).
698 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags)
700 return kmalloc(size, flags | __GFP_ZERO);
704 * kzalloc_node - allocate zeroed memory from a particular memory node.
705 * @size: how many bytes of memory are required.
706 * @flags: the type of memory to allocate (see kmalloc).
707 * @node: memory node from which to allocate
709 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node)
711 return kmalloc_node(size, flags | __GFP_ZERO, node);
714 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
715 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
717 return kvmalloc_node(size, flags, NUMA_NO_NODE);
719 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
721 return kvmalloc_node(size, flags | __GFP_ZERO, node);
723 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
725 return kvmalloc(size, flags | __GFP_ZERO);
728 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
732 if (unlikely(check_mul_overflow(n, size, &bytes)))
735 return kvmalloc(bytes, flags);
738 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
740 return kvmalloc_array(n, size, flags | __GFP_ZERO);
743 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
745 extern void kvfree(const void *addr);
746 extern void kvfree_sensitive(const void *addr, size_t len);
748 unsigned int kmem_cache_size(struct kmem_cache *s);
751 * kmalloc_size_roundup - Report allocation bucket size for the given size
753 * @size: Number of bytes to round up from.
755 * This returns the number of bytes that would be available in a kmalloc()
756 * allocation of @size bytes. For example, a 126 byte request would be
757 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly
758 * for the general-purpose kmalloc()-based allocations, and is not for the
759 * pre-sized kmem_cache_alloc()-based allocations.)
761 * Use this to kmalloc() the full bucket size ahead of time instead of using
762 * ksize() to query the size after an allocation.
764 size_t kmalloc_size_roundup(size_t size);
766 void __init kmem_cache_init_late(void);
768 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
769 int slab_prepare_cpu(unsigned int cpu);
770 int slab_dead_cpu(unsigned int cpu);
772 #define slab_prepare_cpu NULL
773 #define slab_dead_cpu NULL
776 #endif /* _LINUX_SLAB_H */