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>
21 #include <linux/cleanup.h>
25 * Flags to pass to kmem_cache_create().
26 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
28 /* DEBUG: Perform (expensive) checks on alloc/free */
29 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U)
30 /* DEBUG: Red zone objs in a cache */
31 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U)
32 /* DEBUG: Poison objects */
33 #define SLAB_POISON ((slab_flags_t __force)0x00000800U)
34 /* Indicate a kmalloc slab */
35 #define SLAB_KMALLOC ((slab_flags_t __force)0x00001000U)
36 /* Align objs on cache lines */
37 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U)
38 /* Use GFP_DMA memory */
39 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U)
40 /* Use GFP_DMA32 memory */
41 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U)
42 /* DEBUG: Store the last owner for bug hunting */
43 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U)
44 /* Panic if kmem_cache_create() fails */
45 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U)
47 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
49 * This delays freeing the SLAB page by a grace period, it does _NOT_
50 * delay object freeing. This means that if you do kmem_cache_free()
51 * that memory location is free to be reused at any time. Thus it may
52 * be possible to see another object there in the same RCU grace period.
54 * This feature only ensures the memory location backing the object
55 * stays valid, the trick to using this is relying on an independent
56 * object validation pass. Something like:
60 * obj = lockless_lookup(key);
62 * if (!try_get_ref(obj)) // might fail for free objects
66 * if (obj->key != key) { // not the object we expected
74 * This is useful if we need to approach a kernel structure obliquely,
75 * from its address obtained without the usual locking. We can lock
76 * the structure to stabilize it and check it's still at the given address,
77 * only if we can be sure that the memory has not been meanwhile reused
78 * for some other kind of object (which our subsystem's lock might corrupt).
80 * rcu_read_lock before reading the address, then rcu_read_unlock after
81 * taking the spinlock within the structure expected at that address.
83 * Note that it is not possible to acquire a lock within a structure
84 * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference
85 * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages
86 * are not zeroed before being given to the slab, which means that any
87 * locks must be initialized after each and every kmem_struct_alloc().
88 * Alternatively, make the ctor passed to kmem_cache_create() initialize
89 * the locks at page-allocation time, as is done in __i915_request_ctor(),
90 * sighand_ctor(), and anon_vma_ctor(). Such a ctor permits readers
91 * to safely acquire those ctor-initialized locks under rcu_read_lock()
94 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
96 /* Defer freeing slabs to RCU */
97 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U)
98 /* Spread some memory over cpuset */
99 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U)
100 /* Trace allocations and frees */
101 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U)
103 /* Flag to prevent checks on free */
104 #ifdef CONFIG_DEBUG_OBJECTS
105 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U)
107 # define SLAB_DEBUG_OBJECTS 0
110 /* Avoid kmemleak tracing */
111 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U)
114 * Prevent merging with compatible kmem caches. This flag should be used
115 * cautiously. Valid use cases:
117 * - caches created for self-tests (e.g. kunit)
118 * - general caches created and used by a subsystem, only when a
119 * (subsystem-specific) debug option is enabled
120 * - performance critical caches, should be very rare and consulted with slab
121 * maintainers, and not used together with CONFIG_SLUB_TINY
123 #define SLAB_NO_MERGE ((slab_flags_t __force)0x01000000U)
125 /* Fault injection mark */
126 #ifdef CONFIG_FAILSLAB
127 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U)
129 # define SLAB_FAILSLAB 0
131 /* Account to memcg */
132 #ifdef CONFIG_MEMCG_KMEM
133 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U)
135 # define SLAB_ACCOUNT 0
138 #ifdef CONFIG_KASAN_GENERIC
139 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U)
145 * Ignore user specified debugging flags.
146 * Intended for caches created for self-tests so they have only flags
147 * specified in the code and other flags are ignored.
149 #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U)
152 #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U)
154 #define SLAB_SKIP_KFENCE 0
157 /* The following flags affect the page allocator grouping pages by mobility */
158 /* Objects are reclaimable */
159 #ifndef CONFIG_SLUB_TINY
160 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U)
162 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0)
164 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
167 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
169 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
171 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
172 * Both make kfree a no-op.
174 #define ZERO_SIZE_PTR ((void *)16)
176 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
177 (unsigned long)ZERO_SIZE_PTR)
179 #include <linux/kasan.h>
184 * struct kmem_cache related prototypes
186 bool slab_is_available(void);
188 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
189 unsigned int align, slab_flags_t flags,
190 void (*ctor)(void *));
191 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
192 unsigned int size, unsigned int align,
194 unsigned int useroffset, unsigned int usersize,
195 void (*ctor)(void *));
196 void kmem_cache_destroy(struct kmem_cache *s);
197 int kmem_cache_shrink(struct kmem_cache *s);
200 * Please use this macro to create slab caches. Simply specify the
201 * name of the structure and maybe some flags that are listed above.
203 * The alignment of the struct determines object alignment. If you
204 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
205 * then the objects will be properly aligned in SMP configurations.
207 #define KMEM_CACHE(__struct, __flags) \
208 kmem_cache_create(#__struct, sizeof(struct __struct), \
209 __alignof__(struct __struct), (__flags), NULL)
212 * To whitelist a single field for copying to/from usercopy, use this
213 * macro instead for KMEM_CACHE() above.
215 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
216 kmem_cache_create_usercopy(#__struct, \
217 sizeof(struct __struct), \
218 __alignof__(struct __struct), (__flags), \
219 offsetof(struct __struct, __field), \
220 sizeof_field(struct __struct, __field), NULL)
223 * Common kmalloc functions provided by all allocators
225 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2);
226 void kfree(const void *objp);
227 void kfree_sensitive(const void *objp);
228 size_t __ksize(const void *objp);
230 DEFINE_FREE(kfree, void *, if (_T) kfree(_T))
233 * ksize - Report actual allocation size of associated object
235 * @objp: Pointer returned from a prior kmalloc()-family allocation.
237 * This should not be used for writing beyond the originally requested
238 * allocation size. Either use krealloc() or round up the allocation size
239 * with kmalloc_size_roundup() prior to allocation. If this is used to
240 * access beyond the originally requested allocation size, UBSAN_BOUNDS
241 * and/or FORTIFY_SOURCE may trip, since they only know about the
242 * originally allocated size via the __alloc_size attribute.
244 size_t ksize(const void *objp);
247 bool kmem_valid_obj(void *object);
248 void kmem_dump_obj(void *object);
252 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
253 * alignment larger than the alignment of a 64-bit integer.
254 * Setting ARCH_DMA_MINALIGN in arch headers allows that.
256 #ifdef ARCH_HAS_DMA_MINALIGN
257 #if ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN)
258 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
262 #ifndef ARCH_KMALLOC_MINALIGN
263 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
264 #elif ARCH_KMALLOC_MINALIGN > 8
265 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
266 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
270 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
271 * Intended for arches that get misalignment faults even for 64 bit integer
274 #ifndef ARCH_SLAB_MINALIGN
275 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
279 * Arches can define this function if they want to decide the minimum slab
280 * alignment at runtime. The value returned by the function must be a power
281 * of two and >= ARCH_SLAB_MINALIGN.
283 #ifndef arch_slab_minalign
284 static inline unsigned int arch_slab_minalign(void)
286 return ARCH_SLAB_MINALIGN;
291 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN.
292 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN
293 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment.
295 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
296 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
297 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
300 * Kmalloc array related definitions
305 * SLAB and SLUB directly allocates requests fitting in to an order-1 page
306 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
308 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
309 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
310 #ifndef KMALLOC_SHIFT_LOW
311 #define KMALLOC_SHIFT_LOW 5
316 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
317 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
318 #ifndef KMALLOC_SHIFT_LOW
319 #define KMALLOC_SHIFT_LOW 3
323 /* Maximum allocatable size */
324 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
325 /* Maximum size for which we actually use a slab cache */
326 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
327 /* Maximum order allocatable via the slab allocator */
328 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
333 #ifndef KMALLOC_MIN_SIZE
334 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
338 * This restriction comes from byte sized index implementation.
339 * Page size is normally 2^12 bytes and, in this case, if we want to use
340 * byte sized index which can represent 2^8 entries, the size of the object
341 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
342 * If minimum size of kmalloc is less than 16, we use it as minimum object
343 * size and give up to use byte sized index.
345 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
346 (KMALLOC_MIN_SIZE) : 16)
349 * Whenever changing this, take care of that kmalloc_type() and
350 * create_kmalloc_caches() still work as intended.
352 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP
353 * is for accounted but unreclaimable and non-dma objects. All the other
354 * kmem caches can have both accounted and unaccounted objects.
356 enum kmalloc_cache_type {
358 #ifndef CONFIG_ZONE_DMA
359 KMALLOC_DMA = KMALLOC_NORMAL,
361 #ifndef CONFIG_MEMCG_KMEM
362 KMALLOC_CGROUP = KMALLOC_NORMAL,
364 #ifdef CONFIG_SLUB_TINY
365 KMALLOC_RECLAIM = KMALLOC_NORMAL,
369 #ifdef CONFIG_ZONE_DMA
372 #ifdef CONFIG_MEMCG_KMEM
378 extern struct kmem_cache *
379 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
382 * Define gfp bits that should not be set for KMALLOC_NORMAL.
384 #define KMALLOC_NOT_NORMAL_BITS \
385 (__GFP_RECLAIMABLE | \
386 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \
387 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0))
389 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
392 * The most common case is KMALLOC_NORMAL, so test for it
393 * with a single branch for all the relevant flags.
395 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0))
396 return KMALLOC_NORMAL;
399 * At least one of the flags has to be set. Their priorities in
400 * decreasing order are:
402 * 2) __GFP_RECLAIMABLE
405 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
407 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE))
408 return KMALLOC_RECLAIM;
410 return KMALLOC_CGROUP;
414 * Figure out which kmalloc slab an allocation of a certain size
418 * 2 = 129 .. 192 bytes
419 * n = 2^(n-1)+1 .. 2^n
421 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
422 * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
423 * Callers where !size_is_constant should only be test modules, where runtime
424 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab().
426 static __always_inline unsigned int __kmalloc_index(size_t size,
427 bool size_is_constant)
432 if (size <= KMALLOC_MIN_SIZE)
433 return KMALLOC_SHIFT_LOW;
435 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
437 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
439 if (size <= 8) return 3;
440 if (size <= 16) return 4;
441 if (size <= 32) return 5;
442 if (size <= 64) return 6;
443 if (size <= 128) return 7;
444 if (size <= 256) return 8;
445 if (size <= 512) return 9;
446 if (size <= 1024) return 10;
447 if (size <= 2 * 1024) return 11;
448 if (size <= 4 * 1024) return 12;
449 if (size <= 8 * 1024) return 13;
450 if (size <= 16 * 1024) return 14;
451 if (size <= 32 * 1024) return 15;
452 if (size <= 64 * 1024) return 16;
453 if (size <= 128 * 1024) return 17;
454 if (size <= 256 * 1024) return 18;
455 if (size <= 512 * 1024) return 19;
456 if (size <= 1024 * 1024) return 20;
457 if (size <= 2 * 1024 * 1024) return 21;
459 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
460 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
464 /* Will never be reached. Needed because the compiler may complain */
467 static_assert(PAGE_SHIFT <= 20);
468 #define kmalloc_index(s) __kmalloc_index(s, true)
470 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
473 * kmem_cache_alloc - Allocate an object
474 * @cachep: The cache to allocate from.
475 * @flags: See kmalloc().
477 * Allocate an object from this cache.
478 * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags.
480 * Return: pointer to the new object or %NULL in case of error
482 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) __assume_slab_alignment __malloc;
483 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
484 gfp_t gfpflags) __assume_slab_alignment __malloc;
485 void kmem_cache_free(struct kmem_cache *s, void *objp);
488 * Bulk allocation and freeing operations. These are accelerated in an
489 * allocator specific way to avoid taking locks repeatedly or building
490 * metadata structures unnecessarily.
492 * Note that interrupts must be enabled when calling these functions.
494 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
495 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p);
497 static __always_inline void kfree_bulk(size_t size, void **p)
499 kmem_cache_free_bulk(NULL, size, p);
502 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
504 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment
507 void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size)
508 __assume_kmalloc_alignment __alloc_size(3);
510 void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
511 int node, size_t size) __assume_kmalloc_alignment
513 void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment
516 void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment
520 * kmalloc - allocate kernel memory
521 * @size: how many bytes of memory are required.
522 * @flags: describe the allocation context
524 * kmalloc is the normal method of allocating memory
525 * for objects smaller than page size in the kernel.
527 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN
528 * bytes. For @size of power of two bytes, the alignment is also guaranteed
529 * to be at least to the size.
531 * The @flags argument may be one of the GFP flags defined at
532 * include/linux/gfp_types.h and described at
533 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
535 * The recommended usage of the @flags is described at
536 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>`
538 * Below is a brief outline of the most useful GFP flags
541 * Allocate normal kernel ram. May sleep.
544 * Allocation will not sleep.
547 * Allocation will not sleep. May use emergency pools.
549 * Also it is possible to set different flags by OR'ing
550 * in one or more of the following additional @flags:
553 * Zero the allocated memory before returning. Also see kzalloc().
556 * This allocation has high priority and may use emergency pools.
559 * Indicate that this allocation is in no way allowed to fail
560 * (think twice before using).
563 * If memory is not immediately available,
564 * then give up at once.
567 * If allocation fails, don't issue any warnings.
569 * %__GFP_RETRY_MAYFAIL
570 * Try really hard to succeed the allocation but fail
573 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
575 if (__builtin_constant_p(size) && size) {
578 if (size > KMALLOC_MAX_CACHE_SIZE)
579 return kmalloc_large(size, flags);
581 index = kmalloc_index(size);
582 return kmalloc_trace(
583 kmalloc_caches[kmalloc_type(flags)][index],
586 return __kmalloc(size, flags);
589 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
591 if (__builtin_constant_p(size) && size) {
594 if (size > KMALLOC_MAX_CACHE_SIZE)
595 return kmalloc_large_node(size, flags, node);
597 index = kmalloc_index(size);
598 return kmalloc_node_trace(
599 kmalloc_caches[kmalloc_type(flags)][index],
602 return __kmalloc_node(size, flags, node);
606 * kmalloc_array - allocate memory for an array.
607 * @n: number of elements.
608 * @size: element size.
609 * @flags: the type of memory to allocate (see kmalloc).
611 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags)
615 if (unlikely(check_mul_overflow(n, size, &bytes)))
617 if (__builtin_constant_p(n) && __builtin_constant_p(size))
618 return kmalloc(bytes, flags);
619 return __kmalloc(bytes, flags);
623 * krealloc_array - reallocate memory for an array.
624 * @p: pointer to the memory chunk to reallocate
625 * @new_n: new number of elements to alloc
626 * @new_size: new size of a single member of the array
627 * @flags: the type of memory to allocate (see kmalloc)
629 static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p,
636 if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
639 return krealloc(p, bytes, flags);
643 * kcalloc - allocate memory for an array. The memory is set to zero.
644 * @n: number of elements.
645 * @size: element size.
646 * @flags: the type of memory to allocate (see kmalloc).
648 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags)
650 return kmalloc_array(n, size, flags | __GFP_ZERO);
653 void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node,
654 unsigned long caller) __alloc_size(1);
655 #define kmalloc_node_track_caller(size, flags, node) \
656 __kmalloc_node_track_caller(size, flags, node, \
660 * kmalloc_track_caller is a special version of kmalloc that records the
661 * calling function of the routine calling it for slab leak tracking instead
662 * of just the calling function (confusing, eh?).
663 * It's useful when the call to kmalloc comes from a widely-used standard
664 * allocator where we care about the real place the memory allocation
665 * request comes from.
667 #define kmalloc_track_caller(size, flags) \
668 __kmalloc_node_track_caller(size, flags, \
669 NUMA_NO_NODE, _RET_IP_)
671 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
676 if (unlikely(check_mul_overflow(n, size, &bytes)))
678 if (__builtin_constant_p(n) && __builtin_constant_p(size))
679 return kmalloc_node(bytes, flags, node);
680 return __kmalloc_node(bytes, flags, node);
683 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
685 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
691 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
693 return kmem_cache_alloc(k, flags | __GFP_ZERO);
697 * kzalloc - allocate memory. The memory is set to zero.
698 * @size: how many bytes of memory are required.
699 * @flags: the type of memory to allocate (see kmalloc).
701 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags)
703 return kmalloc(size, flags | __GFP_ZERO);
707 * kzalloc_node - allocate zeroed memory from a particular memory node.
708 * @size: how many bytes of memory are required.
709 * @flags: the type of memory to allocate (see kmalloc).
710 * @node: memory node from which to allocate
712 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node)
714 return kmalloc_node(size, flags | __GFP_ZERO, node);
717 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
718 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
720 return kvmalloc_node(size, flags, NUMA_NO_NODE);
722 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
724 return kvmalloc_node(size, flags | __GFP_ZERO, node);
726 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
728 return kvmalloc(size, flags | __GFP_ZERO);
731 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
735 if (unlikely(check_mul_overflow(n, size, &bytes)))
738 return kvmalloc(bytes, flags);
741 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
743 return kvmalloc_array(n, size, flags | __GFP_ZERO);
746 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
748 extern void kvfree(const void *addr);
749 extern void kvfree_sensitive(const void *addr, size_t len);
751 unsigned int kmem_cache_size(struct kmem_cache *s);
754 * kmalloc_size_roundup - Report allocation bucket size for the given size
756 * @size: Number of bytes to round up from.
758 * This returns the number of bytes that would be available in a kmalloc()
759 * allocation of @size bytes. For example, a 126 byte request would be
760 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly
761 * for the general-purpose kmalloc()-based allocations, and is not for the
762 * pre-sized kmem_cache_alloc()-based allocations.)
764 * Use this to kmalloc() the full bucket size ahead of time instead of using
765 * ksize() to query the size after an allocation.
767 size_t kmalloc_size_roundup(size_t size);
769 void __init kmem_cache_init_late(void);
771 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
772 int slab_prepare_cpu(unsigned int cpu);
773 int slab_dead_cpu(unsigned int cpu);
775 #define slab_prepare_cpu NULL
776 #define slab_dead_cpu NULL
779 #endif /* _LINUX_SLAB_H */