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Andrew Scullb4b6d4a2019-01-02 15:54:55 +00001/* 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>
David Brazdil0f672f62019-12-10 10:32:29 +000019#include <linux/percpu-refcount.h>
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000020
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)
David Brazdil0f672f62019-12-10 10:32:29 +000036/* Use GFP_DMA32 memory */
37#define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U)
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000038/* 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 */
David Brazdil0f672f62019-12-10 10:32:29 +0000119
120/* Slab deactivation flag */
121#define SLAB_DEACTIVATED ((slab_flags_t __force)0x10000000U)
122
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000123/*
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
145extern bool usercopy_fallback;
146
147struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
148 unsigned int align, slab_flags_t flags,
149 void (*ctor)(void *));
150struct kmem_cache *kmem_cache_create_usercopy(const char *name,
151 unsigned int size, unsigned int align,
152 slab_flags_t flags,
153 unsigned int useroffset, unsigned int usersize,
154 void (*ctor)(void *));
155void kmem_cache_destroy(struct kmem_cache *);
156int kmem_cache_shrink(struct kmem_cache *);
157
158void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
David Brazdil0f672f62019-12-10 10:32:29 +0000159void memcg_deactivate_kmem_caches(struct mem_cgroup *, struct mem_cgroup *);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000160
161/*
162 * Please use this macro to create slab caches. Simply specify the
163 * name of the structure and maybe some flags that are listed above.
164 *
165 * The alignment of the struct determines object alignment. If you
166 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
167 * then the objects will be properly aligned in SMP configurations.
168 */
169#define KMEM_CACHE(__struct, __flags) \
170 kmem_cache_create(#__struct, sizeof(struct __struct), \
171 __alignof__(struct __struct), (__flags), NULL)
172
173/*
174 * To whitelist a single field for copying to/from usercopy, use this
175 * macro instead for KMEM_CACHE() above.
176 */
177#define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
178 kmem_cache_create_usercopy(#__struct, \
179 sizeof(struct __struct), \
180 __alignof__(struct __struct), (__flags), \
181 offsetof(struct __struct, __field), \
182 sizeof_field(struct __struct, __field), NULL)
183
184/*
185 * Common kmalloc functions provided by all allocators
186 */
187void * __must_check __krealloc(const void *, size_t, gfp_t);
188void * __must_check krealloc(const void *, size_t, gfp_t);
189void kfree(const void *);
190void kzfree(const void *);
David Brazdil0f672f62019-12-10 10:32:29 +0000191size_t __ksize(const void *);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000192size_t ksize(const void *);
193
194#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
195void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
196 bool to_user);
197#else
198static inline void __check_heap_object(const void *ptr, unsigned long n,
199 struct page *page, bool to_user) { }
200#endif
201
202/*
203 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
204 * alignment larger than the alignment of a 64-bit integer.
205 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
206 */
207#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
208#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
209#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
210#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
211#else
212#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
213#endif
214
215/*
216 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
217 * Intended for arches that get misalignment faults even for 64 bit integer
218 * aligned buffers.
219 */
220#ifndef ARCH_SLAB_MINALIGN
221#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
222#endif
223
224/*
225 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
226 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
227 * aligned pointers.
228 */
229#define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
230#define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
231#define __assume_page_alignment __assume_aligned(PAGE_SIZE)
232
233/*
234 * Kmalloc array related definitions
235 */
236
237#ifdef CONFIG_SLAB
238/*
239 * The largest kmalloc size supported by the SLAB allocators is
240 * 32 megabyte (2^25) or the maximum allocatable page order if that is
241 * less than 32 MB.
242 *
243 * WARNING: Its not easy to increase this value since the allocators have
244 * to do various tricks to work around compiler limitations in order to
245 * ensure proper constant folding.
246 */
247#define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
248 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
249#define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
250#ifndef KMALLOC_SHIFT_LOW
251#define KMALLOC_SHIFT_LOW 5
252#endif
253#endif
254
255#ifdef CONFIG_SLUB
256/*
257 * SLUB directly allocates requests fitting in to an order-1 page
258 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
259 */
260#define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
261#define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
262#ifndef KMALLOC_SHIFT_LOW
263#define KMALLOC_SHIFT_LOW 3
264#endif
265#endif
266
267#ifdef CONFIG_SLOB
268/*
269 * SLOB passes all requests larger than one page to the page allocator.
270 * No kmalloc array is necessary since objects of different sizes can
271 * be allocated from the same page.
272 */
273#define KMALLOC_SHIFT_HIGH PAGE_SHIFT
274#define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
275#ifndef KMALLOC_SHIFT_LOW
276#define KMALLOC_SHIFT_LOW 3
277#endif
278#endif
279
280/* Maximum allocatable size */
281#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
282/* Maximum size for which we actually use a slab cache */
283#define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
284/* Maximum order allocatable via the slab allocagtor */
285#define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
286
287/*
288 * Kmalloc subsystem.
289 */
290#ifndef KMALLOC_MIN_SIZE
291#define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
292#endif
293
294/*
295 * This restriction comes from byte sized index implementation.
296 * Page size is normally 2^12 bytes and, in this case, if we want to use
297 * byte sized index which can represent 2^8 entries, the size of the object
298 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
299 * If minimum size of kmalloc is less than 16, we use it as minimum object
300 * size and give up to use byte sized index.
301 */
302#define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
303 (KMALLOC_MIN_SIZE) : 16)
304
David Brazdil0f672f62019-12-10 10:32:29 +0000305/*
306 * Whenever changing this, take care of that kmalloc_type() and
307 * create_kmalloc_caches() still work as intended.
308 */
309enum kmalloc_cache_type {
310 KMALLOC_NORMAL = 0,
311 KMALLOC_RECLAIM,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000312#ifdef CONFIG_ZONE_DMA
David Brazdil0f672f62019-12-10 10:32:29 +0000313 KMALLOC_DMA,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000314#endif
David Brazdil0f672f62019-12-10 10:32:29 +0000315 NR_KMALLOC_TYPES
316};
317
318#ifndef CONFIG_SLOB
319extern struct kmem_cache *
320kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
321
322static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
323{
324#ifdef CONFIG_ZONE_DMA
325 /*
326 * The most common case is KMALLOC_NORMAL, so test for it
327 * with a single branch for both flags.
328 */
329 if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0))
330 return KMALLOC_NORMAL;
331
332 /*
333 * At least one of the flags has to be set. If both are, __GFP_DMA
334 * is more important.
335 */
336 return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM;
337#else
338 return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL;
339#endif
340}
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000341
342/*
343 * Figure out which kmalloc slab an allocation of a certain size
344 * belongs to.
345 * 0 = zero alloc
346 * 1 = 65 .. 96 bytes
347 * 2 = 129 .. 192 bytes
348 * n = 2^(n-1)+1 .. 2^n
349 */
350static __always_inline unsigned int kmalloc_index(size_t size)
351{
352 if (!size)
353 return 0;
354
355 if (size <= KMALLOC_MIN_SIZE)
356 return KMALLOC_SHIFT_LOW;
357
358 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
359 return 1;
360 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
361 return 2;
362 if (size <= 8) return 3;
363 if (size <= 16) return 4;
364 if (size <= 32) return 5;
365 if (size <= 64) return 6;
366 if (size <= 128) return 7;
367 if (size <= 256) return 8;
368 if (size <= 512) return 9;
369 if (size <= 1024) return 10;
370 if (size <= 2 * 1024) return 11;
371 if (size <= 4 * 1024) return 12;
372 if (size <= 8 * 1024) return 13;
373 if (size <= 16 * 1024) return 14;
374 if (size <= 32 * 1024) return 15;
375 if (size <= 64 * 1024) return 16;
376 if (size <= 128 * 1024) return 17;
377 if (size <= 256 * 1024) return 18;
378 if (size <= 512 * 1024) return 19;
379 if (size <= 1024 * 1024) return 20;
380 if (size <= 2 * 1024 * 1024) return 21;
381 if (size <= 4 * 1024 * 1024) return 22;
382 if (size <= 8 * 1024 * 1024) return 23;
383 if (size <= 16 * 1024 * 1024) return 24;
384 if (size <= 32 * 1024 * 1024) return 25;
385 if (size <= 64 * 1024 * 1024) return 26;
386 BUG();
387
388 /* Will never be reached. Needed because the compiler may complain */
389 return -1;
390}
391#endif /* !CONFIG_SLOB */
392
393void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
394void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
395void kmem_cache_free(struct kmem_cache *, void *);
396
397/*
398 * Bulk allocation and freeing operations. These are accelerated in an
399 * allocator specific way to avoid taking locks repeatedly or building
400 * metadata structures unnecessarily.
401 *
402 * Note that interrupts must be enabled when calling these functions.
403 */
404void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
405int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
406
407/*
408 * Caller must not use kfree_bulk() on memory not originally allocated
409 * by kmalloc(), because the SLOB allocator cannot handle this.
410 */
411static __always_inline void kfree_bulk(size_t size, void **p)
412{
413 kmem_cache_free_bulk(NULL, size, p);
414}
415
416#ifdef CONFIG_NUMA
417void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
418void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;
419#else
420static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
421{
422 return __kmalloc(size, flags);
423}
424
425static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
426{
427 return kmem_cache_alloc(s, flags);
428}
429#endif
430
431#ifdef CONFIG_TRACING
432extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc;
433
434#ifdef CONFIG_NUMA
435extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
436 gfp_t gfpflags,
437 int node, size_t size) __assume_slab_alignment __malloc;
438#else
439static __always_inline void *
440kmem_cache_alloc_node_trace(struct kmem_cache *s,
441 gfp_t gfpflags,
442 int node, size_t size)
443{
444 return kmem_cache_alloc_trace(s, gfpflags, size);
445}
446#endif /* CONFIG_NUMA */
447
448#else /* CONFIG_TRACING */
449static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
450 gfp_t flags, size_t size)
451{
452 void *ret = kmem_cache_alloc(s, flags);
453
David Brazdil0f672f62019-12-10 10:32:29 +0000454 ret = kasan_kmalloc(s, ret, size, flags);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000455 return ret;
456}
457
458static __always_inline void *
459kmem_cache_alloc_node_trace(struct kmem_cache *s,
460 gfp_t gfpflags,
461 int node, size_t size)
462{
463 void *ret = kmem_cache_alloc_node(s, gfpflags, node);
464
David Brazdil0f672f62019-12-10 10:32:29 +0000465 ret = kasan_kmalloc(s, ret, size, gfpflags);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000466 return ret;
467}
468#endif /* CONFIG_TRACING */
469
470extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
471
472#ifdef CONFIG_TRACING
473extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
474#else
475static __always_inline void *
476kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
477{
478 return kmalloc_order(size, flags, order);
479}
480#endif
481
482static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
483{
484 unsigned int order = get_order(size);
485 return kmalloc_order_trace(size, flags, order);
486}
487
488/**
489 * kmalloc - allocate memory
490 * @size: how many bytes of memory are required.
491 * @flags: the type of memory to allocate.
492 *
493 * kmalloc is the normal method of allocating memory
494 * for objects smaller than page size in the kernel.
495 *
David Brazdil0f672f62019-12-10 10:32:29 +0000496 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN
497 * bytes. For @size of power of two bytes, the alignment is also guaranteed
498 * to be at least to the size.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000499 *
David Brazdil0f672f62019-12-10 10:32:29 +0000500 * The @flags argument may be one of the GFP flags defined at
501 * include/linux/gfp.h and described at
502 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000503 *
David Brazdil0f672f62019-12-10 10:32:29 +0000504 * The recommended usage of the @flags is described at
505 * :ref:`Documentation/core-api/memory-allocation.rst <memory-allocation>`
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000506 *
David Brazdil0f672f62019-12-10 10:32:29 +0000507 * Below is a brief outline of the most useful GFP flags
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000508 *
David Brazdil0f672f62019-12-10 10:32:29 +0000509 * %GFP_KERNEL
510 * Allocate normal kernel ram. May sleep.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000511 *
David Brazdil0f672f62019-12-10 10:32:29 +0000512 * %GFP_NOWAIT
513 * Allocation will not sleep.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000514 *
David Brazdil0f672f62019-12-10 10:32:29 +0000515 * %GFP_ATOMIC
516 * Allocation will not sleep. May use emergency pools.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000517 *
David Brazdil0f672f62019-12-10 10:32:29 +0000518 * %GFP_HIGHUSER
519 * Allocate memory from high memory on behalf of user.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000520 *
521 * Also it is possible to set different flags by OR'ing
522 * in one or more of the following additional @flags:
523 *
David Brazdil0f672f62019-12-10 10:32:29 +0000524 * %__GFP_HIGH
525 * This allocation has high priority and may use emergency pools.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000526 *
David Brazdil0f672f62019-12-10 10:32:29 +0000527 * %__GFP_NOFAIL
528 * Indicate that this allocation is in no way allowed to fail
529 * (think twice before using).
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000530 *
David Brazdil0f672f62019-12-10 10:32:29 +0000531 * %__GFP_NORETRY
532 * If memory is not immediately available,
533 * then give up at once.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000534 *
David Brazdil0f672f62019-12-10 10:32:29 +0000535 * %__GFP_NOWARN
536 * If allocation fails, don't issue any warnings.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000537 *
David Brazdil0f672f62019-12-10 10:32:29 +0000538 * %__GFP_RETRY_MAYFAIL
539 * Try really hard to succeed the allocation but fail
540 * eventually.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000541 */
542static __always_inline void *kmalloc(size_t size, gfp_t flags)
543{
544 if (__builtin_constant_p(size)) {
David Brazdil0f672f62019-12-10 10:32:29 +0000545#ifndef CONFIG_SLOB
546 unsigned int index;
547#endif
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000548 if (size > KMALLOC_MAX_CACHE_SIZE)
549 return kmalloc_large(size, flags);
550#ifndef CONFIG_SLOB
David Brazdil0f672f62019-12-10 10:32:29 +0000551 index = kmalloc_index(size);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000552
David Brazdil0f672f62019-12-10 10:32:29 +0000553 if (!index)
554 return ZERO_SIZE_PTR;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000555
David Brazdil0f672f62019-12-10 10:32:29 +0000556 return kmem_cache_alloc_trace(
557 kmalloc_caches[kmalloc_type(flags)][index],
558 flags, size);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000559#endif
560 }
561 return __kmalloc(size, flags);
562}
563
564/*
565 * Determine size used for the nth kmalloc cache.
566 * return size or 0 if a kmalloc cache for that
567 * size does not exist
568 */
569static __always_inline unsigned int kmalloc_size(unsigned int n)
570{
571#ifndef CONFIG_SLOB
572 if (n > 2)
573 return 1U << n;
574
575 if (n == 1 && KMALLOC_MIN_SIZE <= 32)
576 return 96;
577
578 if (n == 2 && KMALLOC_MIN_SIZE <= 64)
579 return 192;
580#endif
581 return 0;
582}
583
584static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
585{
586#ifndef CONFIG_SLOB
587 if (__builtin_constant_p(size) &&
David Brazdil0f672f62019-12-10 10:32:29 +0000588 size <= KMALLOC_MAX_CACHE_SIZE) {
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000589 unsigned int i = kmalloc_index(size);
590
591 if (!i)
592 return ZERO_SIZE_PTR;
593
David Brazdil0f672f62019-12-10 10:32:29 +0000594 return kmem_cache_alloc_node_trace(
595 kmalloc_caches[kmalloc_type(flags)][i],
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000596 flags, node, size);
597 }
598#endif
599 return __kmalloc_node(size, flags, node);
600}
601
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000602int memcg_update_all_caches(int num_memcgs);
603
604/**
605 * kmalloc_array - allocate memory for an array.
606 * @n: number of elements.
607 * @size: element size.
608 * @flags: the type of memory to allocate (see kmalloc).
609 */
610static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
611{
612 size_t bytes;
613
614 if (unlikely(check_mul_overflow(n, size, &bytes)))
615 return NULL;
616 if (__builtin_constant_p(n) && __builtin_constant_p(size))
617 return kmalloc(bytes, flags);
618 return __kmalloc(bytes, flags);
619}
620
621/**
622 * kcalloc - allocate memory for an array. The memory is set to zero.
623 * @n: number of elements.
624 * @size: element size.
625 * @flags: the type of memory to allocate (see kmalloc).
626 */
627static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
628{
629 return kmalloc_array(n, size, flags | __GFP_ZERO);
630}
631
632/*
633 * kmalloc_track_caller is a special version of kmalloc that records the
634 * calling function of the routine calling it for slab leak tracking instead
635 * of just the calling function (confusing, eh?).
636 * It's useful when the call to kmalloc comes from a widely-used standard
637 * allocator where we care about the real place the memory allocation
638 * request comes from.
639 */
640extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
641#define kmalloc_track_caller(size, flags) \
642 __kmalloc_track_caller(size, flags, _RET_IP_)
643
644static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
645 int node)
646{
647 size_t bytes;
648
649 if (unlikely(check_mul_overflow(n, size, &bytes)))
650 return NULL;
651 if (__builtin_constant_p(n) && __builtin_constant_p(size))
652 return kmalloc_node(bytes, flags, node);
653 return __kmalloc_node(bytes, flags, node);
654}
655
656static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
657{
658 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
659}
660
661
662#ifdef CONFIG_NUMA
663extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
664#define kmalloc_node_track_caller(size, flags, node) \
665 __kmalloc_node_track_caller(size, flags, node, \
666 _RET_IP_)
667
668#else /* CONFIG_NUMA */
669
670#define kmalloc_node_track_caller(size, flags, node) \
671 kmalloc_track_caller(size, flags)
672
673#endif /* CONFIG_NUMA */
674
675/*
676 * Shortcuts
677 */
678static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
679{
680 return kmem_cache_alloc(k, flags | __GFP_ZERO);
681}
682
683/**
684 * kzalloc - allocate memory. The memory is set to zero.
685 * @size: how many bytes of memory are required.
686 * @flags: the type of memory to allocate (see kmalloc).
687 */
688static inline void *kzalloc(size_t size, gfp_t flags)
689{
690 return kmalloc(size, flags | __GFP_ZERO);
691}
692
693/**
694 * kzalloc_node - allocate zeroed memory from a particular memory node.
695 * @size: how many bytes of memory are required.
696 * @flags: the type of memory to allocate (see kmalloc).
697 * @node: memory node from which to allocate
698 */
699static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
700{
701 return kmalloc_node(size, flags | __GFP_ZERO, node);
702}
703
704unsigned int kmem_cache_size(struct kmem_cache *s);
705void __init kmem_cache_init_late(void);
706
707#if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
708int slab_prepare_cpu(unsigned int cpu);
709int slab_dead_cpu(unsigned int cpu);
710#else
711#define slab_prepare_cpu NULL
712#define slab_dead_cpu NULL
713#endif
714
715#endif /* _LINUX_SLAB_H */