| /* SPDX-License-Identifier: GPL-2.0 */ | 
 | /* | 
 |  * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). | 
 |  * | 
 |  * (C) SGI 2006, Christoph Lameter | 
 |  * 	Cleaned up and restructured to ease the addition of alternative | 
 |  * 	implementations of SLAB allocators. | 
 |  * (C) Linux Foundation 2008-2013 | 
 |  *      Unified interface for all slab allocators | 
 |  */ | 
 |  | 
 | #ifndef _LINUX_SLAB_H | 
 | #define	_LINUX_SLAB_H | 
 |  | 
 | #include <linux/gfp.h> | 
 | #include <linux/overflow.h> | 
 | #include <linux/types.h> | 
 | #include <linux/workqueue.h> | 
 | #include <linux/percpu-refcount.h> | 
 |  | 
 |  | 
 | /* | 
 |  * Flags to pass to kmem_cache_create(). | 
 |  * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set. | 
 |  */ | 
 | /* DEBUG: Perform (expensive) checks on alloc/free */ | 
 | #define SLAB_CONSISTENCY_CHECKS	((slab_flags_t __force)0x00000100U) | 
 | /* DEBUG: Red zone objs in a cache */ | 
 | #define SLAB_RED_ZONE		((slab_flags_t __force)0x00000400U) | 
 | /* DEBUG: Poison objects */ | 
 | #define SLAB_POISON		((slab_flags_t __force)0x00000800U) | 
 | /* Align objs on cache lines */ | 
 | #define SLAB_HWCACHE_ALIGN	((slab_flags_t __force)0x00002000U) | 
 | /* Use GFP_DMA memory */ | 
 | #define SLAB_CACHE_DMA		((slab_flags_t __force)0x00004000U) | 
 | /* Use GFP_DMA32 memory */ | 
 | #define SLAB_CACHE_DMA32	((slab_flags_t __force)0x00008000U) | 
 | /* DEBUG: Store the last owner for bug hunting */ | 
 | #define SLAB_STORE_USER		((slab_flags_t __force)0x00010000U) | 
 | /* Panic if kmem_cache_create() fails */ | 
 | #define SLAB_PANIC		((slab_flags_t __force)0x00040000U) | 
 | /* | 
 |  * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS! | 
 |  * | 
 |  * This delays freeing the SLAB page by a grace period, it does _NOT_ | 
 |  * delay object freeing. This means that if you do kmem_cache_free() | 
 |  * that memory location is free to be reused at any time. Thus it may | 
 |  * be possible to see another object there in the same RCU grace period. | 
 |  * | 
 |  * This feature only ensures the memory location backing the object | 
 |  * stays valid, the trick to using this is relying on an independent | 
 |  * object validation pass. Something like: | 
 |  * | 
 |  *  rcu_read_lock() | 
 |  * again: | 
 |  *  obj = lockless_lookup(key); | 
 |  *  if (obj) { | 
 |  *    if (!try_get_ref(obj)) // might fail for free objects | 
 |  *      goto again; | 
 |  * | 
 |  *    if (obj->key != key) { // not the object we expected | 
 |  *      put_ref(obj); | 
 |  *      goto again; | 
 |  *    } | 
 |  *  } | 
 |  *  rcu_read_unlock(); | 
 |  * | 
 |  * This is useful if we need to approach a kernel structure obliquely, | 
 |  * from its address obtained without the usual locking. We can lock | 
 |  * the structure to stabilize it and check it's still at the given address, | 
 |  * only if we can be sure that the memory has not been meanwhile reused | 
 |  * for some other kind of object (which our subsystem's lock might corrupt). | 
 |  * | 
 |  * rcu_read_lock before reading the address, then rcu_read_unlock after | 
 |  * taking the spinlock within the structure expected at that address. | 
 |  * | 
 |  * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. | 
 |  */ | 
 | /* Defer freeing slabs to RCU */ | 
 | #define SLAB_TYPESAFE_BY_RCU	((slab_flags_t __force)0x00080000U) | 
 | /* Spread some memory over cpuset */ | 
 | #define SLAB_MEM_SPREAD		((slab_flags_t __force)0x00100000U) | 
 | /* Trace allocations and frees */ | 
 | #define SLAB_TRACE		((slab_flags_t __force)0x00200000U) | 
 |  | 
 | /* Flag to prevent checks on free */ | 
 | #ifdef CONFIG_DEBUG_OBJECTS | 
 | # define SLAB_DEBUG_OBJECTS	((slab_flags_t __force)0x00400000U) | 
 | #else | 
 | # define SLAB_DEBUG_OBJECTS	0 | 
 | #endif | 
 |  | 
 | /* Avoid kmemleak tracing */ | 
 | #define SLAB_NOLEAKTRACE	((slab_flags_t __force)0x00800000U) | 
 |  | 
 | /* Fault injection mark */ | 
 | #ifdef CONFIG_FAILSLAB | 
 | # define SLAB_FAILSLAB		((slab_flags_t __force)0x02000000U) | 
 | #else | 
 | # define SLAB_FAILSLAB		0 | 
 | #endif | 
 | /* Account to memcg */ | 
 | #ifdef CONFIG_MEMCG_KMEM | 
 | # define SLAB_ACCOUNT		((slab_flags_t __force)0x04000000U) | 
 | #else | 
 | # define SLAB_ACCOUNT		0 | 
 | #endif | 
 |  | 
 | #ifdef CONFIG_KASAN | 
 | #define SLAB_KASAN		((slab_flags_t __force)0x08000000U) | 
 | #else | 
 | #define SLAB_KASAN		0 | 
 | #endif | 
 |  | 
 | /* The following flags affect the page allocator grouping pages by mobility */ | 
 | /* Objects are reclaimable */ | 
 | #define SLAB_RECLAIM_ACCOUNT	((slab_flags_t __force)0x00020000U) | 
 | #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */ | 
 |  | 
 | /* Slab deactivation flag */ | 
 | #define SLAB_DEACTIVATED	((slab_flags_t __force)0x10000000U) | 
 |  | 
 | /* | 
 |  * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. | 
 |  * | 
 |  * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. | 
 |  * | 
 |  * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. | 
 |  * Both make kfree a no-op. | 
 |  */ | 
 | #define ZERO_SIZE_PTR ((void *)16) | 
 |  | 
 | #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ | 
 | 				(unsigned long)ZERO_SIZE_PTR) | 
 |  | 
 | #include <linux/kasan.h> | 
 |  | 
 | struct mem_cgroup; | 
 | /* | 
 |  * struct kmem_cache related prototypes | 
 |  */ | 
 | void __init kmem_cache_init(void); | 
 | bool slab_is_available(void); | 
 |  | 
 | extern bool usercopy_fallback; | 
 |  | 
 | struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, | 
 | 			unsigned int align, slab_flags_t flags, | 
 | 			void (*ctor)(void *)); | 
 | struct kmem_cache *kmem_cache_create_usercopy(const char *name, | 
 | 			unsigned int size, unsigned int align, | 
 | 			slab_flags_t flags, | 
 | 			unsigned int useroffset, unsigned int usersize, | 
 | 			void (*ctor)(void *)); | 
 | void kmem_cache_destroy(struct kmem_cache *); | 
 | int kmem_cache_shrink(struct kmem_cache *); | 
 |  | 
 | void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *); | 
 | void memcg_deactivate_kmem_caches(struct mem_cgroup *, struct mem_cgroup *); | 
 |  | 
 | /* | 
 |  * Please use this macro to create slab caches. Simply specify the | 
 |  * name of the structure and maybe some flags that are listed above. | 
 |  * | 
 |  * The alignment of the struct determines object alignment. If you | 
 |  * f.e. add ____cacheline_aligned_in_smp to the struct declaration | 
 |  * then the objects will be properly aligned in SMP configurations. | 
 |  */ | 
 | #define KMEM_CACHE(__struct, __flags)					\ | 
 | 		kmem_cache_create(#__struct, sizeof(struct __struct),	\ | 
 | 			__alignof__(struct __struct), (__flags), NULL) | 
 |  | 
 | /* | 
 |  * To whitelist a single field for copying to/from usercopy, use this | 
 |  * macro instead for KMEM_CACHE() above. | 
 |  */ | 
 | #define KMEM_CACHE_USERCOPY(__struct, __flags, __field)			\ | 
 | 		kmem_cache_create_usercopy(#__struct,			\ | 
 | 			sizeof(struct __struct),			\ | 
 | 			__alignof__(struct __struct), (__flags),	\ | 
 | 			offsetof(struct __struct, __field),		\ | 
 | 			sizeof_field(struct __struct, __field), NULL) | 
 |  | 
 | /* | 
 |  * Common kmalloc functions provided by all allocators | 
 |  */ | 
 | void * __must_check __krealloc(const void *, size_t, gfp_t); | 
 | void * __must_check krealloc(const void *, size_t, gfp_t); | 
 | void kfree(const void *); | 
 | void kzfree(const void *); | 
 | size_t __ksize(const void *); | 
 | size_t ksize(const void *); | 
 |  | 
 | #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR | 
 | void __check_heap_object(const void *ptr, unsigned long n, struct page *page, | 
 | 			bool to_user); | 
 | #else | 
 | static inline void __check_heap_object(const void *ptr, unsigned long n, | 
 | 				       struct page *page, bool to_user) { } | 
 | #endif | 
 |  | 
 | /* | 
 |  * Some archs want to perform DMA into kmalloc caches and need a guaranteed | 
 |  * alignment larger than the alignment of a 64-bit integer. | 
 |  * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. | 
 |  */ | 
 | #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 | 
 | #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN | 
 | #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN | 
 | #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) | 
 | #else | 
 | #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) | 
 | #endif | 
 |  | 
 | /* | 
 |  * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. | 
 |  * Intended for arches that get misalignment faults even for 64 bit integer | 
 |  * aligned buffers. | 
 |  */ | 
 | #ifndef ARCH_SLAB_MINALIGN | 
 | #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) | 
 | #endif | 
 |  | 
 | /* | 
 |  * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned | 
 |  * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN | 
 |  * aligned pointers. | 
 |  */ | 
 | #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) | 
 | #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) | 
 | #define __assume_page_alignment __assume_aligned(PAGE_SIZE) | 
 |  | 
 | /* | 
 |  * Kmalloc array related definitions | 
 |  */ | 
 |  | 
 | #ifdef CONFIG_SLAB | 
 | /* | 
 |  * The largest kmalloc size supported by the SLAB allocators is | 
 |  * 32 megabyte (2^25) or the maximum allocatable page order if that is | 
 |  * less than 32 MB. | 
 |  * | 
 |  * WARNING: Its not easy to increase this value since the allocators have | 
 |  * to do various tricks to work around compiler limitations in order to | 
 |  * ensure proper constant folding. | 
 |  */ | 
 | #define KMALLOC_SHIFT_HIGH	((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ | 
 | 				(MAX_ORDER + PAGE_SHIFT - 1) : 25) | 
 | #define KMALLOC_SHIFT_MAX	KMALLOC_SHIFT_HIGH | 
 | #ifndef KMALLOC_SHIFT_LOW | 
 | #define KMALLOC_SHIFT_LOW	5 | 
 | #endif | 
 | #endif | 
 |  | 
 | #ifdef CONFIG_SLUB | 
 | /* | 
 |  * SLUB directly allocates requests fitting in to an order-1 page | 
 |  * (PAGE_SIZE*2).  Larger requests are passed to the page allocator. | 
 |  */ | 
 | #define KMALLOC_SHIFT_HIGH	(PAGE_SHIFT + 1) | 
 | #define KMALLOC_SHIFT_MAX	(MAX_ORDER + PAGE_SHIFT - 1) | 
 | #ifndef KMALLOC_SHIFT_LOW | 
 | #define KMALLOC_SHIFT_LOW	3 | 
 | #endif | 
 | #endif | 
 |  | 
 | #ifdef CONFIG_SLOB | 
 | /* | 
 |  * SLOB passes all requests larger than one page to the page allocator. | 
 |  * No kmalloc array is necessary since objects of different sizes can | 
 |  * be allocated from the same page. | 
 |  */ | 
 | #define KMALLOC_SHIFT_HIGH	PAGE_SHIFT | 
 | #define KMALLOC_SHIFT_MAX	(MAX_ORDER + PAGE_SHIFT - 1) | 
 | #ifndef KMALLOC_SHIFT_LOW | 
 | #define KMALLOC_SHIFT_LOW	3 | 
 | #endif | 
 | #endif | 
 |  | 
 | /* Maximum allocatable size */ | 
 | #define KMALLOC_MAX_SIZE	(1UL << KMALLOC_SHIFT_MAX) | 
 | /* Maximum size for which we actually use a slab cache */ | 
 | #define KMALLOC_MAX_CACHE_SIZE	(1UL << KMALLOC_SHIFT_HIGH) | 
 | /* Maximum order allocatable via the slab allocagtor */ | 
 | #define KMALLOC_MAX_ORDER	(KMALLOC_SHIFT_MAX - PAGE_SHIFT) | 
 |  | 
 | /* | 
 |  * Kmalloc subsystem. | 
 |  */ | 
 | #ifndef KMALLOC_MIN_SIZE | 
 | #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) | 
 | #endif | 
 |  | 
 | /* | 
 |  * This restriction comes from byte sized index implementation. | 
 |  * Page size is normally 2^12 bytes and, in this case, if we want to use | 
 |  * byte sized index which can represent 2^8 entries, the size of the object | 
 |  * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. | 
 |  * If minimum size of kmalloc is less than 16, we use it as minimum object | 
 |  * size and give up to use byte sized index. | 
 |  */ | 
 | #define SLAB_OBJ_MIN_SIZE      (KMALLOC_MIN_SIZE < 16 ? \ | 
 |                                (KMALLOC_MIN_SIZE) : 16) | 
 |  | 
 | /* | 
 |  * Whenever changing this, take care of that kmalloc_type() and | 
 |  * create_kmalloc_caches() still work as intended. | 
 |  */ | 
 | enum kmalloc_cache_type { | 
 | 	KMALLOC_NORMAL = 0, | 
 | 	KMALLOC_RECLAIM, | 
 | #ifdef CONFIG_ZONE_DMA | 
 | 	KMALLOC_DMA, | 
 | #endif | 
 | 	NR_KMALLOC_TYPES | 
 | }; | 
 |  | 
 | #ifndef CONFIG_SLOB | 
 | extern struct kmem_cache * | 
 | kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; | 
 |  | 
 | static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) | 
 | { | 
 | #ifdef CONFIG_ZONE_DMA | 
 | 	/* | 
 | 	 * The most common case is KMALLOC_NORMAL, so test for it | 
 | 	 * with a single branch for both flags. | 
 | 	 */ | 
 | 	if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0)) | 
 | 		return KMALLOC_NORMAL; | 
 |  | 
 | 	/* | 
 | 	 * At least one of the flags has to be set. If both are, __GFP_DMA | 
 | 	 * is more important. | 
 | 	 */ | 
 | 	return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM; | 
 | #else | 
 | 	return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL; | 
 | #endif | 
 | } | 
 |  | 
 | /* | 
 |  * Figure out which kmalloc slab an allocation of a certain size | 
 |  * belongs to. | 
 |  * 0 = zero alloc | 
 |  * 1 =  65 .. 96 bytes | 
 |  * 2 = 129 .. 192 bytes | 
 |  * n = 2^(n-1)+1 .. 2^n | 
 |  */ | 
 | static __always_inline unsigned int kmalloc_index(size_t size) | 
 | { | 
 | 	if (!size) | 
 | 		return 0; | 
 |  | 
 | 	if (size <= KMALLOC_MIN_SIZE) | 
 | 		return KMALLOC_SHIFT_LOW; | 
 |  | 
 | 	if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) | 
 | 		return 1; | 
 | 	if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) | 
 | 		return 2; | 
 | 	if (size <=          8) return 3; | 
 | 	if (size <=         16) return 4; | 
 | 	if (size <=         32) return 5; | 
 | 	if (size <=         64) return 6; | 
 | 	if (size <=        128) return 7; | 
 | 	if (size <=        256) return 8; | 
 | 	if (size <=        512) return 9; | 
 | 	if (size <=       1024) return 10; | 
 | 	if (size <=   2 * 1024) return 11; | 
 | 	if (size <=   4 * 1024) return 12; | 
 | 	if (size <=   8 * 1024) return 13; | 
 | 	if (size <=  16 * 1024) return 14; | 
 | 	if (size <=  32 * 1024) return 15; | 
 | 	if (size <=  64 * 1024) return 16; | 
 | 	if (size <= 128 * 1024) return 17; | 
 | 	if (size <= 256 * 1024) return 18; | 
 | 	if (size <= 512 * 1024) return 19; | 
 | 	if (size <= 1024 * 1024) return 20; | 
 | 	if (size <=  2 * 1024 * 1024) return 21; | 
 | 	if (size <=  4 * 1024 * 1024) return 22; | 
 | 	if (size <=  8 * 1024 * 1024) return 23; | 
 | 	if (size <=  16 * 1024 * 1024) return 24; | 
 | 	if (size <=  32 * 1024 * 1024) return 25; | 
 | 	if (size <=  64 * 1024 * 1024) return 26; | 
 | 	BUG(); | 
 |  | 
 | 	/* Will never be reached. Needed because the compiler may complain */ | 
 | 	return -1; | 
 | } | 
 | #endif /* !CONFIG_SLOB */ | 
 |  | 
 | void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc; | 
 | void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc; | 
 | void kmem_cache_free(struct kmem_cache *, void *); | 
 |  | 
 | /* | 
 |  * Bulk allocation and freeing operations. These are accelerated in an | 
 |  * allocator specific way to avoid taking locks repeatedly or building | 
 |  * metadata structures unnecessarily. | 
 |  * | 
 |  * Note that interrupts must be enabled when calling these functions. | 
 |  */ | 
 | void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); | 
 | int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); | 
 |  | 
 | /* | 
 |  * Caller must not use kfree_bulk() on memory not originally allocated | 
 |  * by kmalloc(), because the SLOB allocator cannot handle this. | 
 |  */ | 
 | static __always_inline void kfree_bulk(size_t size, void **p) | 
 | { | 
 | 	kmem_cache_free_bulk(NULL, size, p); | 
 | } | 
 |  | 
 | #ifdef CONFIG_NUMA | 
 | void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc; | 
 | void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc; | 
 | #else | 
 | static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node) | 
 | { | 
 | 	return __kmalloc(size, flags); | 
 | } | 
 |  | 
 | static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) | 
 | { | 
 | 	return kmem_cache_alloc(s, flags); | 
 | } | 
 | #endif | 
 |  | 
 | #ifdef CONFIG_TRACING | 
 | extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc; | 
 |  | 
 | #ifdef CONFIG_NUMA | 
 | extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, | 
 | 					   gfp_t gfpflags, | 
 | 					   int node, size_t size) __assume_slab_alignment __malloc; | 
 | #else | 
 | static __always_inline void * | 
 | kmem_cache_alloc_node_trace(struct kmem_cache *s, | 
 | 			      gfp_t gfpflags, | 
 | 			      int node, size_t size) | 
 | { | 
 | 	return kmem_cache_alloc_trace(s, gfpflags, size); | 
 | } | 
 | #endif /* CONFIG_NUMA */ | 
 |  | 
 | #else /* CONFIG_TRACING */ | 
 | static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s, | 
 | 		gfp_t flags, size_t size) | 
 | { | 
 | 	void *ret = kmem_cache_alloc(s, flags); | 
 |  | 
 | 	ret = kasan_kmalloc(s, ret, size, flags); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static __always_inline void * | 
 | kmem_cache_alloc_node_trace(struct kmem_cache *s, | 
 | 			      gfp_t gfpflags, | 
 | 			      int node, size_t size) | 
 | { | 
 | 	void *ret = kmem_cache_alloc_node(s, gfpflags, node); | 
 |  | 
 | 	ret = kasan_kmalloc(s, ret, size, gfpflags); | 
 | 	return ret; | 
 | } | 
 | #endif /* CONFIG_TRACING */ | 
 |  | 
 | extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; | 
 |  | 
 | #ifdef CONFIG_TRACING | 
 | extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc; | 
 | #else | 
 | static __always_inline void * | 
 | kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) | 
 | { | 
 | 	return kmalloc_order(size, flags, order); | 
 | } | 
 | #endif | 
 |  | 
 | static __always_inline void *kmalloc_large(size_t size, gfp_t flags) | 
 | { | 
 | 	unsigned int order = get_order(size); | 
 | 	return kmalloc_order_trace(size, flags, order); | 
 | } | 
 |  | 
 | /** | 
 |  * kmalloc - allocate memory | 
 |  * @size: how many bytes of memory are required. | 
 |  * @flags: the type of memory to allocate. | 
 |  * | 
 |  * kmalloc is the normal method of allocating memory | 
 |  * for objects smaller than page size in the kernel. | 
 |  * | 
 |  * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN | 
 |  * bytes. For @size of power of two bytes, the alignment is also guaranteed | 
 |  * to be at least to the size. | 
 |  * | 
 |  * The @flags argument may be one of the GFP flags defined at | 
 |  * include/linux/gfp.h and described at | 
 |  * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` | 
 |  * | 
 |  * The recommended usage of the @flags is described at | 
 |  * :ref:`Documentation/core-api/memory-allocation.rst <memory-allocation>` | 
 |  * | 
 |  * Below is a brief outline of the most useful GFP flags | 
 |  * | 
 |  * %GFP_KERNEL | 
 |  *	Allocate normal kernel ram. May sleep. | 
 |  * | 
 |  * %GFP_NOWAIT | 
 |  *	Allocation will not sleep. | 
 |  * | 
 |  * %GFP_ATOMIC | 
 |  *	Allocation will not sleep.  May use emergency pools. | 
 |  * | 
 |  * %GFP_HIGHUSER | 
 |  *	Allocate memory from high memory on behalf of user. | 
 |  * | 
 |  * Also it is possible to set different flags by OR'ing | 
 |  * in one or more of the following additional @flags: | 
 |  * | 
 |  * %__GFP_HIGH | 
 |  *	This allocation has high priority and may use emergency pools. | 
 |  * | 
 |  * %__GFP_NOFAIL | 
 |  *	Indicate that this allocation is in no way allowed to fail | 
 |  *	(think twice before using). | 
 |  * | 
 |  * %__GFP_NORETRY | 
 |  *	If memory is not immediately available, | 
 |  *	then give up at once. | 
 |  * | 
 |  * %__GFP_NOWARN | 
 |  *	If allocation fails, don't issue any warnings. | 
 |  * | 
 |  * %__GFP_RETRY_MAYFAIL | 
 |  *	Try really hard to succeed the allocation but fail | 
 |  *	eventually. | 
 |  */ | 
 | static __always_inline void *kmalloc(size_t size, gfp_t flags) | 
 | { | 
 | 	if (__builtin_constant_p(size)) { | 
 | #ifndef CONFIG_SLOB | 
 | 		unsigned int index; | 
 | #endif | 
 | 		if (size > KMALLOC_MAX_CACHE_SIZE) | 
 | 			return kmalloc_large(size, flags); | 
 | #ifndef CONFIG_SLOB | 
 | 		index = kmalloc_index(size); | 
 |  | 
 | 		if (!index) | 
 | 			return ZERO_SIZE_PTR; | 
 |  | 
 | 		return kmem_cache_alloc_trace( | 
 | 				kmalloc_caches[kmalloc_type(flags)][index], | 
 | 				flags, size); | 
 | #endif | 
 | 	} | 
 | 	return __kmalloc(size, flags); | 
 | } | 
 |  | 
 | /* | 
 |  * Determine size used for the nth kmalloc cache. | 
 |  * return size or 0 if a kmalloc cache for that | 
 |  * size does not exist | 
 |  */ | 
 | static __always_inline unsigned int kmalloc_size(unsigned int n) | 
 | { | 
 | #ifndef CONFIG_SLOB | 
 | 	if (n > 2) | 
 | 		return 1U << n; | 
 |  | 
 | 	if (n == 1 && KMALLOC_MIN_SIZE <= 32) | 
 | 		return 96; | 
 |  | 
 | 	if (n == 2 && KMALLOC_MIN_SIZE <= 64) | 
 | 		return 192; | 
 | #endif | 
 | 	return 0; | 
 | } | 
 |  | 
 | static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) | 
 | { | 
 | #ifndef CONFIG_SLOB | 
 | 	if (__builtin_constant_p(size) && | 
 | 		size <= KMALLOC_MAX_CACHE_SIZE) { | 
 | 		unsigned int i = kmalloc_index(size); | 
 |  | 
 | 		if (!i) | 
 | 			return ZERO_SIZE_PTR; | 
 |  | 
 | 		return kmem_cache_alloc_node_trace( | 
 | 				kmalloc_caches[kmalloc_type(flags)][i], | 
 | 						flags, node, size); | 
 | 	} | 
 | #endif | 
 | 	return __kmalloc_node(size, flags, node); | 
 | } | 
 |  | 
 | int memcg_update_all_caches(int num_memcgs); | 
 |  | 
 | /** | 
 |  * kmalloc_array - allocate memory for an array. | 
 |  * @n: number of elements. | 
 |  * @size: element size. | 
 |  * @flags: the type of memory to allocate (see kmalloc). | 
 |  */ | 
 | static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) | 
 | { | 
 | 	size_t bytes; | 
 |  | 
 | 	if (unlikely(check_mul_overflow(n, size, &bytes))) | 
 | 		return NULL; | 
 | 	if (__builtin_constant_p(n) && __builtin_constant_p(size)) | 
 | 		return kmalloc(bytes, flags); | 
 | 	return __kmalloc(bytes, flags); | 
 | } | 
 |  | 
 | /** | 
 |  * kcalloc - allocate memory for an array. The memory is set to zero. | 
 |  * @n: number of elements. | 
 |  * @size: element size. | 
 |  * @flags: the type of memory to allocate (see kmalloc). | 
 |  */ | 
 | static inline void *kcalloc(size_t n, size_t size, gfp_t flags) | 
 | { | 
 | 	return kmalloc_array(n, size, flags | __GFP_ZERO); | 
 | } | 
 |  | 
 | /* | 
 |  * kmalloc_track_caller is a special version of kmalloc that records the | 
 |  * calling function of the routine calling it for slab leak tracking instead | 
 |  * of just the calling function (confusing, eh?). | 
 |  * It's useful when the call to kmalloc comes from a widely-used standard | 
 |  * allocator where we care about the real place the memory allocation | 
 |  * request comes from. | 
 |  */ | 
 | extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long); | 
 | #define kmalloc_track_caller(size, flags) \ | 
 | 	__kmalloc_track_caller(size, flags, _RET_IP_) | 
 |  | 
 | static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, | 
 | 				       int node) | 
 | { | 
 | 	size_t bytes; | 
 |  | 
 | 	if (unlikely(check_mul_overflow(n, size, &bytes))) | 
 | 		return NULL; | 
 | 	if (__builtin_constant_p(n) && __builtin_constant_p(size)) | 
 | 		return kmalloc_node(bytes, flags, node); | 
 | 	return __kmalloc_node(bytes, flags, node); | 
 | } | 
 |  | 
 | static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) | 
 | { | 
 | 	return kmalloc_array_node(n, size, flags | __GFP_ZERO, node); | 
 | } | 
 |  | 
 |  | 
 | #ifdef CONFIG_NUMA | 
 | extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long); | 
 | #define kmalloc_node_track_caller(size, flags, node) \ | 
 | 	__kmalloc_node_track_caller(size, flags, node, \ | 
 | 			_RET_IP_) | 
 |  | 
 | #else /* CONFIG_NUMA */ | 
 |  | 
 | #define kmalloc_node_track_caller(size, flags, node) \ | 
 | 	kmalloc_track_caller(size, flags) | 
 |  | 
 | #endif /* CONFIG_NUMA */ | 
 |  | 
 | /* | 
 |  * Shortcuts | 
 |  */ | 
 | static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) | 
 | { | 
 | 	return kmem_cache_alloc(k, flags | __GFP_ZERO); | 
 | } | 
 |  | 
 | /** | 
 |  * kzalloc - allocate memory. The memory is set to zero. | 
 |  * @size: how many bytes of memory are required. | 
 |  * @flags: the type of memory to allocate (see kmalloc). | 
 |  */ | 
 | static inline void *kzalloc(size_t size, gfp_t flags) | 
 | { | 
 | 	return kmalloc(size, flags | __GFP_ZERO); | 
 | } | 
 |  | 
 | /** | 
 |  * kzalloc_node - allocate zeroed memory from a particular memory node. | 
 |  * @size: how many bytes of memory are required. | 
 |  * @flags: the type of memory to allocate (see kmalloc). | 
 |  * @node: memory node from which to allocate | 
 |  */ | 
 | static inline void *kzalloc_node(size_t size, gfp_t flags, int node) | 
 | { | 
 | 	return kmalloc_node(size, flags | __GFP_ZERO, node); | 
 | } | 
 |  | 
 | unsigned int kmem_cache_size(struct kmem_cache *s); | 
 | void __init kmem_cache_init_late(void); | 
 |  | 
 | #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) | 
 | int slab_prepare_cpu(unsigned int cpu); | 
 | int slab_dead_cpu(unsigned int cpu); | 
 | #else | 
 | #define slab_prepare_cpu	NULL | 
 | #define slab_dead_cpu		NULL | 
 | #endif | 
 |  | 
 | #endif	/* _LINUX_SLAB_H */ |