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
138struct mem_cgroup;
139/*
140 * struct kmem_cache related prototypes
141 */
142void __init kmem_cache_init(void);
143bool slab_is_available(void);
144
145struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
146			unsigned int align, slab_flags_t flags,
147			void (*ctor)(void *));
148struct kmem_cache *kmem_cache_create_usercopy(const char *name,
149			unsigned int size, unsigned int align,
150			slab_flags_t flags,
151			unsigned int useroffset, unsigned int usersize,
152			void (*ctor)(void *));
153void kmem_cache_destroy(struct kmem_cache *s);
154int kmem_cache_shrink(struct kmem_cache *s);
155
156/*
157 * Please use this macro to create slab caches. Simply specify the
158 * name of the structure and maybe some flags that are listed above.
159 *
160 * The alignment of the struct determines object alignment. If you
161 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
162 * then the objects will be properly aligned in SMP configurations.
163 */
164#define KMEM_CACHE(__struct, __flags)					\
165		kmem_cache_create(#__struct, sizeof(struct __struct),	\
166			__alignof__(struct __struct), (__flags), NULL)
167
168/*
169 * To whitelist a single field for copying to/from usercopy, use this
170 * macro instead for KMEM_CACHE() above.
171 */
172#define KMEM_CACHE_USERCOPY(__struct, __flags, __field)			\
173		kmem_cache_create_usercopy(#__struct,			\
174			sizeof(struct __struct),			\
175			__alignof__(struct __struct), (__flags),	\
176			offsetof(struct __struct, __field),		\
177			sizeof_field(struct __struct, __field), NULL)
178
179/*
180 * Common kmalloc functions provided by all allocators
181 */
182void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __alloc_size(2);
183void kfree(const void *objp);
184void kfree_sensitive(const void *objp);
185size_t __ksize(const void *objp);
186size_t ksize(const void *objp);
187#ifdef CONFIG_PRINTK
188bool kmem_valid_obj(void *object);
189void kmem_dump_obj(void *object);
190#endif
191
192/*
193 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
194 * alignment larger than the alignment of a 64-bit integer.
195 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
196 */
197#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
198#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
199#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
200#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
201#else
202#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
203#endif
204
205/*
206 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
207 * Intended for arches that get misalignment faults even for 64 bit integer
208 * aligned buffers.
209 */
210#ifndef ARCH_SLAB_MINALIGN
211#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
212#endif
213
214/*
215 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
216 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
217 * aligned pointers.
218 */
219#define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
220#define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
221#define __assume_page_alignment __assume_aligned(PAGE_SIZE)
222
223/*
224 * Kmalloc array related definitions
225 */
226
227#ifdef CONFIG_SLAB
228/*
229 * The largest kmalloc size supported by the SLAB allocators is
230 * 32 megabyte (2^25) or the maximum allocatable page order if that is
231 * less than 32 MB.
232 *
233 * WARNING: Its not easy to increase this value since the allocators have
234 * to do various tricks to work around compiler limitations in order to
235 * ensure proper constant folding.
236 */
237#define KMALLOC_SHIFT_HIGH	((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
238				(MAX_ORDER + PAGE_SHIFT - 1) : 25)
239#define KMALLOC_SHIFT_MAX	KMALLOC_SHIFT_HIGH
240#ifndef KMALLOC_SHIFT_LOW
241#define KMALLOC_SHIFT_LOW	5
242#endif
243#endif
244
245#ifdef CONFIG_SLUB
246/*
247 * SLUB directly allocates requests fitting in to an order-1 page
248 * (PAGE_SIZE*2).  Larger requests are passed to the page allocator.
249 */
250#define KMALLOC_SHIFT_HIGH	(PAGE_SHIFT + 1)
251#define KMALLOC_SHIFT_MAX	(MAX_ORDER + PAGE_SHIFT - 1)
252#ifndef KMALLOC_SHIFT_LOW
253#define KMALLOC_SHIFT_LOW	3
254#endif
255#endif
256
257#ifdef CONFIG_SLOB
258/*
259 * SLOB passes all requests larger than one page to the page allocator.
260 * No kmalloc array is necessary since objects of different sizes can
261 * be allocated from the same page.
262 */
263#define KMALLOC_SHIFT_HIGH	PAGE_SHIFT
264#define KMALLOC_SHIFT_MAX	(MAX_ORDER + PAGE_SHIFT - 1)
265#ifndef KMALLOC_SHIFT_LOW
266#define KMALLOC_SHIFT_LOW	3
267#endif
268#endif
269
270/* Maximum allocatable size */
271#define KMALLOC_MAX_SIZE	(1UL << KMALLOC_SHIFT_MAX)
272/* Maximum size for which we actually use a slab cache */
273#define KMALLOC_MAX_CACHE_SIZE	(1UL << KMALLOC_SHIFT_HIGH)
274/* Maximum order allocatable via the slab allocator */
275#define KMALLOC_MAX_ORDER	(KMALLOC_SHIFT_MAX - PAGE_SHIFT)
276
277/*
278 * Kmalloc subsystem.
279 */
280#ifndef KMALLOC_MIN_SIZE
281#define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
282#endif
283
284/*
285 * This restriction comes from byte sized index implementation.
286 * Page size is normally 2^12 bytes and, in this case, if we want to use
287 * byte sized index which can represent 2^8 entries, the size of the object
288 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
289 * If minimum size of kmalloc is less than 16, we use it as minimum object
290 * size and give up to use byte sized index.
291 */
292#define SLAB_OBJ_MIN_SIZE      (KMALLOC_MIN_SIZE < 16 ? \
293                               (KMALLOC_MIN_SIZE) : 16)
294
295/*
296 * Whenever changing this, take care of that kmalloc_type() and
297 * create_kmalloc_caches() still work as intended.
298 *
299 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP
300 * is for accounted but unreclaimable and non-dma objects. All the other
301 * kmem caches can have both accounted and unaccounted objects.
302 */
303enum kmalloc_cache_type {
304	KMALLOC_NORMAL = 0,
305#ifndef CONFIG_ZONE_DMA
306	KMALLOC_DMA = KMALLOC_NORMAL,
307#endif
308#ifndef CONFIG_MEMCG_KMEM
309	KMALLOC_CGROUP = KMALLOC_NORMAL,
310#else
311	KMALLOC_CGROUP,
312#endif
313	KMALLOC_RECLAIM,
314#ifdef CONFIG_ZONE_DMA
315	KMALLOC_DMA,
316#endif
317	NR_KMALLOC_TYPES
318};
319
320#ifndef CONFIG_SLOB
321extern struct kmem_cache *
322kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
323
324/*
325 * Define gfp bits that should not be set for KMALLOC_NORMAL.
326 */
327#define KMALLOC_NOT_NORMAL_BITS					\
328	(__GFP_RECLAIMABLE |					\
329	(IS_ENABLED(CONFIG_ZONE_DMA)   ? __GFP_DMA : 0) |	\
330	(IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0))
331
332static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
333{
334	/*
335	 * The most common case is KMALLOC_NORMAL, so test for it
336	 * with a single branch for all the relevant flags.
337	 */
338	if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0))
339		return KMALLOC_NORMAL;
340
341	/*
342	 * At least one of the flags has to be set. Their priorities in
343	 * decreasing order are:
344	 *  1) __GFP_DMA
345	 *  2) __GFP_RECLAIMABLE
346	 *  3) __GFP_ACCOUNT
347	 */
348	if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
349		return KMALLOC_DMA;
350	if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE))
351		return KMALLOC_RECLAIM;
352	else
353		return KMALLOC_CGROUP;
354}
355
356/*
357 * Figure out which kmalloc slab an allocation of a certain size
358 * belongs to.
359 * 0 = zero alloc
360 * 1 =  65 .. 96 bytes
361 * 2 = 129 .. 192 bytes
362 * n = 2^(n-1)+1 .. 2^n
363 *
364 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
365 * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
366 * Callers where !size_is_constant should only be test modules, where runtime
367 * overheads of __kmalloc_index() can be tolerated.  Also see kmalloc_slab().
368 */
369static __always_inline unsigned int __kmalloc_index(size_t size,
370						    bool size_is_constant)
371{
372	if (!size)
373		return 0;
374
375	if (size <= KMALLOC_MIN_SIZE)
376		return KMALLOC_SHIFT_LOW;
377
378	if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
379		return 1;
380	if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
381		return 2;
382	if (size <=          8) return 3;
383	if (size <=         16) return 4;
384	if (size <=         32) return 5;
385	if (size <=         64) return 6;
386	if (size <=        128) return 7;
387	if (size <=        256) return 8;
388	if (size <=        512) return 9;
389	if (size <=       1024) return 10;
390	if (size <=   2 * 1024) return 11;
391	if (size <=   4 * 1024) return 12;
392	if (size <=   8 * 1024) return 13;
393	if (size <=  16 * 1024) return 14;
394	if (size <=  32 * 1024) return 15;
395	if (size <=  64 * 1024) return 16;
396	if (size <= 128 * 1024) return 17;
397	if (size <= 256 * 1024) return 18;
398	if (size <= 512 * 1024) return 19;
399	if (size <= 1024 * 1024) return 20;
400	if (size <=  2 * 1024 * 1024) return 21;
401	if (size <=  4 * 1024 * 1024) return 22;
402	if (size <=  8 * 1024 * 1024) return 23;
403	if (size <=  16 * 1024 * 1024) return 24;
404	if (size <=  32 * 1024 * 1024) return 25;
405
406	if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
407		BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
408	else
409		BUG();
410
411	/* Will never be reached. Needed because the compiler may complain */
412	return -1;
413}
414#define kmalloc_index(s) __kmalloc_index(s, true)
415#endif /* !CONFIG_SLOB */
416
417void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
418void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc;
419void kmem_cache_free(struct kmem_cache *s, void *objp);
420
421/*
422 * Bulk allocation and freeing operations. These are accelerated in an
423 * allocator specific way to avoid taking locks repeatedly or building
424 * metadata structures unnecessarily.
425 *
426 * Note that interrupts must be enabled when calling these functions.
427 */
428void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
429int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p);
430
431/*
432 * Caller must not use kfree_bulk() on memory not originally allocated
433 * by kmalloc(), because the SLOB allocator cannot handle this.
434 */
435static __always_inline void kfree_bulk(size_t size, void **p)
436{
437	kmem_cache_free_bulk(NULL, size, p);
438}
439
440#ifdef CONFIG_NUMA
441void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
442							 __alloc_size(1);
443void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment
444									 __malloc;
445#else
446static __always_inline __alloc_size(1) void *__kmalloc_node(size_t size, gfp_t flags, int node)
447{
448	return __kmalloc(size, flags);
449}
450
451static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
452{
453	return kmem_cache_alloc(s, flags);
454}
455#endif
456
457#ifdef CONFIG_TRACING
458extern void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t flags, size_t size)
459				   __assume_slab_alignment __alloc_size(3);
460
461#ifdef CONFIG_NUMA
462extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
463					 int node, size_t size) __assume_slab_alignment
464								__alloc_size(4);
465#else
466static __always_inline __alloc_size(4) void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
467						 gfp_t gfpflags, int node, size_t size)
468{
469	return kmem_cache_alloc_trace(s, gfpflags, size);
470}
471#endif /* CONFIG_NUMA */
472
473#else /* CONFIG_TRACING */
474static __always_inline __alloc_size(3) void *kmem_cache_alloc_trace(struct kmem_cache *s,
475								    gfp_t flags, size_t size)
476{
477	void *ret = kmem_cache_alloc(s, flags);
478
479	ret = kasan_kmalloc(s, ret, size, flags);
480	return ret;
481}
482
483static __always_inline void *kmem_cache_alloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
484							 int node, size_t size)
485{
486	void *ret = kmem_cache_alloc_node(s, gfpflags, node);
487
488	ret = kasan_kmalloc(s, ret, size, gfpflags);
489	return ret;
490}
491#endif /* CONFIG_TRACING */
492
493extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment
494									 __alloc_size(1);
495
496#ifdef CONFIG_TRACING
497extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
498				__assume_page_alignment __alloc_size(1);
499#else
500static __always_inline __alloc_size(1) void *kmalloc_order_trace(size_t size, gfp_t flags,
501								 unsigned int order)
502{
503	return kmalloc_order(size, flags, order);
504}
505#endif
506
507static __always_inline __alloc_size(1) void *kmalloc_large(size_t size, gfp_t flags)
508{
509	unsigned int order = get_order(size);
510	return kmalloc_order_trace(size, flags, order);
511}
512
513/**
514 * kmalloc - allocate memory
515 * @size: how many bytes of memory are required.
516 * @flags: the type of memory to allocate.
517 *
518 * kmalloc is the normal method of allocating memory
519 * for objects smaller than page size in the kernel.
520 *
521 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN
522 * bytes. For @size of power of two bytes, the alignment is also guaranteed
523 * to be at least to the size.
524 *
525 * The @flags argument may be one of the GFP flags defined at
526 * include/linux/gfp.h and described at
527 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
528 *
529 * The recommended usage of the @flags is described at
530 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>`
531 *
532 * Below is a brief outline of the most useful GFP flags
533 *
534 * %GFP_KERNEL
535 *	Allocate normal kernel ram. May sleep.
536 *
537 * %GFP_NOWAIT
538 *	Allocation will not sleep.
539 *
540 * %GFP_ATOMIC
541 *	Allocation will not sleep.  May use emergency pools.
542 *
543 * %GFP_HIGHUSER
544 *	Allocate memory from high memory on behalf of user.
545 *
546 * Also it is possible to set different flags by OR'ing
547 * in one or more of the following additional @flags:
548 *
549 * %__GFP_HIGH
550 *	This allocation has high priority and may use emergency pools.
551 *
552 * %__GFP_NOFAIL
553 *	Indicate that this allocation is in no way allowed to fail
554 *	(think twice before using).
555 *
556 * %__GFP_NORETRY
557 *	If memory is not immediately available,
558 *	then give up at once.
559 *
560 * %__GFP_NOWARN
561 *	If allocation fails, don't issue any warnings.
562 *
563 * %__GFP_RETRY_MAYFAIL
564 *	Try really hard to succeed the allocation but fail
565 *	eventually.
566 */
567static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
568{
569	if (__builtin_constant_p(size)) {
570#ifndef CONFIG_SLOB
571		unsigned int index;
572#endif
573		if (size > KMALLOC_MAX_CACHE_SIZE)
574			return kmalloc_large(size, flags);
575#ifndef CONFIG_SLOB
576		index = kmalloc_index(size);
577
578		if (!index)
579			return ZERO_SIZE_PTR;
580
581		return kmem_cache_alloc_trace(
582				kmalloc_caches[kmalloc_type(flags)][index],
583				flags, size);
584#endif
585	}
586	return __kmalloc(size, flags);
587}
588
589static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
590{
591#ifndef CONFIG_SLOB
592	if (__builtin_constant_p(size) &&
593		size <= KMALLOC_MAX_CACHE_SIZE) {
594		unsigned int i = kmalloc_index(size);
595
596		if (!i)
597			return ZERO_SIZE_PTR;
598
599		return kmem_cache_alloc_node_trace(
600				kmalloc_caches[kmalloc_type(flags)][i],
601						flags, node, size);
602	}
603#endif
604	return __kmalloc_node(size, flags, node);
605}
606
607/**
608 * kmalloc_array - allocate memory for an array.
609 * @n: number of elements.
610 * @size: element size.
611 * @flags: the type of memory to allocate (see kmalloc).
612 */
613static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags)
614{
615	size_t bytes;
616
617	if (unlikely(check_mul_overflow(n, size, &bytes)))
618		return NULL;
619	if (__builtin_constant_p(n) && __builtin_constant_p(size))
620		return kmalloc(bytes, flags);
621	return __kmalloc(bytes, flags);
622}
623
624/**
625 * krealloc_array - reallocate memory for an array.
626 * @p: pointer to the memory chunk to reallocate
627 * @new_n: new number of elements to alloc
628 * @new_size: new size of a single member of the array
629 * @flags: the type of memory to allocate (see kmalloc)
630 */
631static inline __alloc_size(2, 3) void * __must_check krealloc_array(void *p,
632								    size_t new_n,
633								    size_t new_size,
634								    gfp_t flags)
635{
636	size_t bytes;
637
638	if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
639		return NULL;
640
641	return krealloc(p, bytes, flags);
642}
643
644/**
645 * kcalloc - allocate memory for an array. The memory is set to zero.
646 * @n: number of elements.
647 * @size: element size.
648 * @flags: the type of memory to allocate (see kmalloc).
649 */
650static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags)
651{
652	return kmalloc_array(n, size, flags | __GFP_ZERO);
653}
654
655/*
656 * kmalloc_track_caller is a special version of kmalloc that records the
657 * calling function of the routine calling it for slab leak tracking instead
658 * of just the calling function (confusing, eh?).
659 * It's useful when the call to kmalloc comes from a widely-used standard
660 * allocator where we care about the real place the memory allocation
661 * request comes from.
662 */
663extern void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller)
664				   __alloc_size(1);
665#define kmalloc_track_caller(size, flags) \
666	__kmalloc_track_caller(size, flags, _RET_IP_)
667
668static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
669							  int node)
670{
671	size_t bytes;
672
673	if (unlikely(check_mul_overflow(n, size, &bytes)))
674		return NULL;
675	if (__builtin_constant_p(n) && __builtin_constant_p(size))
676		return kmalloc_node(bytes, flags, node);
677	return __kmalloc_node(bytes, flags, node);
678}
679
680static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
681{
682	return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
683}
684
685
686#ifdef CONFIG_NUMA
687extern void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node,
688					 unsigned long caller) __alloc_size(1);
689#define kmalloc_node_track_caller(size, flags, node) \
690	__kmalloc_node_track_caller(size, flags, node, \
691			_RET_IP_)
692
693#else /* CONFIG_NUMA */
694
695#define kmalloc_node_track_caller(size, flags, node) \
696	kmalloc_track_caller(size, flags)
697
698#endif /* CONFIG_NUMA */
699
700/*
701 * Shortcuts
702 */
703static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
704{
705	return kmem_cache_alloc(k, flags | __GFP_ZERO);
706}
707
708/**
709 * kzalloc - allocate memory. The memory is set to zero.
710 * @size: how many bytes of memory are required.
711 * @flags: the type of memory to allocate (see kmalloc).
712 */
713static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags)
714{
715	return kmalloc(size, flags | __GFP_ZERO);
716}
717
718/**
719 * kzalloc_node - allocate zeroed memory from a particular memory node.
720 * @size: how many bytes of memory are required.
721 * @flags: the type of memory to allocate (see kmalloc).
722 * @node: memory node from which to allocate
723 */
724static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node)
725{
726	return kmalloc_node(size, flags | __GFP_ZERO, node);
727}
728
729extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
730static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
731{
732	return kvmalloc_node(size, flags, NUMA_NO_NODE);
733}
734static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
735{
736	return kvmalloc_node(size, flags | __GFP_ZERO, node);
737}
738static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
739{
740	return kvmalloc(size, flags | __GFP_ZERO);
741}
742
743static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
744{
745	size_t bytes;
746
747	if (unlikely(check_mul_overflow(n, size, &bytes)))
748		return NULL;
749
750	return kvmalloc(bytes, flags);
751}
752
753static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
754{
755	return kvmalloc_array(n, size, flags | __GFP_ZERO);
756}
757
758extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
759		      __alloc_size(3);
760extern void kvfree(const void *addr);
761extern void kvfree_sensitive(const void *addr, size_t len);
762
763unsigned int kmem_cache_size(struct kmem_cache *s);
764void __init kmem_cache_init_late(void);
765
766#if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
767int slab_prepare_cpu(unsigned int cpu);
768int slab_dead_cpu(unsigned int cpu);
769#else
770#define slab_prepare_cpu	NULL
771#define slab_dead_cpu		NULL
772#endif
773
774#endif	/* _LINUX_SLAB_H */
775