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
138 struct mem_cgroup;
139 /*
140 * struct kmem_cache related prototypes
141 */
142 void __init kmem_cache_init(void);
143 bool slab_is_available(void);
144
145 extern bool usercopy_fallback;
146
147 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
148 unsigned int align, slab_flags_t flags,
149 void (*ctor)(void *));
150 struct 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 *));
155 void kmem_cache_destroy(struct kmem_cache *);
156 int kmem_cache_shrink(struct kmem_cache *);
157
158 /*
159 * Please use this macro to create slab caches. Simply specify the
160 * name of the structure and maybe some flags that are listed above.
161 *
162 * The alignment of the struct determines object alignment. If you
163 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
164 * then the objects will be properly aligned in SMP configurations.
165 */
166 #define KMEM_CACHE(__struct, __flags) \
167 kmem_cache_create(#__struct, sizeof(struct __struct), \
168 __alignof__(struct __struct), (__flags), NULL)
169
170 /*
171 * To whitelist a single field for copying to/from usercopy, use this
172 * macro instead for KMEM_CACHE() above.
173 */
174 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
175 kmem_cache_create_usercopy(#__struct, \
176 sizeof(struct __struct), \
177 __alignof__(struct __struct), (__flags), \
178 offsetof(struct __struct, __field), \
179 sizeof_field(struct __struct, __field), NULL)
180
181 /*
182 * Common kmalloc functions provided by all allocators
183 */
184 void * __must_check krealloc(const void *, size_t, gfp_t);
185 void kfree(const void *);
186 void kfree_sensitive(const void *);
187 size_t __ksize(const void *);
188 size_t ksize(const void *);
189
190 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
191 void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
192 bool to_user);
193 #else
__check_heap_object(const void * ptr,unsigned long n,struct page * page,bool to_user)194 static inline void __check_heap_object(const void *ptr, unsigned long n,
195 struct page *page, bool to_user) { }
196 #endif
197
198 /*
199 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
200 * alignment larger than the alignment of a 64-bit integer.
201 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
202 */
203 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
204 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
205 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
206 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
207 #else
208 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
209 #endif
210
211 /*
212 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
213 * Intended for arches that get misalignment faults even for 64 bit integer
214 * aligned buffers.
215 */
216 #ifndef ARCH_SLAB_MINALIGN
217 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
218 #endif
219
220 /*
221 * Arches can define this function if they want to decide the minimum slab
222 * alignment at runtime. The value returned by the function must be a power
223 * of two and >= ARCH_SLAB_MINALIGN.
224 */
225 #ifndef arch_slab_minalign
arch_slab_minalign(void)226 static inline unsigned int arch_slab_minalign(void)
227 {
228 return ARCH_SLAB_MINALIGN;
229 }
230 #endif
231
232 /*
233 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
234 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
235 * aligned pointers.
236 */
237 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
238 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
239 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
240
241 /*
242 * Kmalloc array related definitions
243 */
244
245 #ifdef CONFIG_SLAB
246 /*
247 * The largest kmalloc size supported by the SLAB allocators is
248 * 32 megabyte (2^25) or the maximum allocatable page order if that is
249 * less than 32 MB.
250 *
251 * WARNING: Its not easy to increase this value since the allocators have
252 * to do various tricks to work around compiler limitations in order to
253 * ensure proper constant folding.
254 */
255 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
256 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
257 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
258 #ifndef KMALLOC_SHIFT_LOW
259 #define KMALLOC_SHIFT_LOW 5
260 #endif
261 #endif
262
263 #ifdef CONFIG_SLUB
264 /*
265 * SLUB directly allocates requests fitting in to an order-1 page
266 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
267 */
268 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
269 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
270 #ifndef KMALLOC_SHIFT_LOW
271 #define KMALLOC_SHIFT_LOW 3
272 #endif
273 #endif
274
275 #ifdef CONFIG_SLOB
276 /*
277 * SLOB passes all requests larger than one page to the page allocator.
278 * No kmalloc array is necessary since objects of different sizes can
279 * be allocated from the same page.
280 */
281 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
282 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
283 #ifndef KMALLOC_SHIFT_LOW
284 #define KMALLOC_SHIFT_LOW 3
285 #endif
286 #endif
287
288 /* Maximum allocatable size */
289 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
290 /* Maximum size for which we actually use a slab cache */
291 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
292 /* Maximum order allocatable via the slab allocator */
293 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
294
295 /*
296 * Kmalloc subsystem.
297 */
298 #ifndef KMALLOC_MIN_SIZE
299 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
300 #endif
301
302 /*
303 * This restriction comes from byte sized index implementation.
304 * Page size is normally 2^12 bytes and, in this case, if we want to use
305 * byte sized index which can represent 2^8 entries, the size of the object
306 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
307 * If minimum size of kmalloc is less than 16, we use it as minimum object
308 * size and give up to use byte sized index.
309 */
310 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
311 (KMALLOC_MIN_SIZE) : 16)
312
313 /*
314 * Whenever changing this, take care of that kmalloc_type() and
315 * create_kmalloc_caches() still work as intended.
316 */
317 enum kmalloc_cache_type {
318 KMALLOC_NORMAL = 0,
319 KMALLOC_RECLAIM,
320 #ifdef CONFIG_ZONE_DMA
321 KMALLOC_DMA,
322 #endif
323 NR_KMALLOC_TYPES
324 };
325
326 #ifndef CONFIG_SLOB
327 extern struct kmem_cache *
328 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
329
kmalloc_type(gfp_t flags)330 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
331 {
332 #ifdef CONFIG_ZONE_DMA
333 /*
334 * The most common case is KMALLOC_NORMAL, so test for it
335 * with a single branch for both flags.
336 */
337 if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0))
338 return KMALLOC_NORMAL;
339
340 /*
341 * At least one of the flags has to be set. If both are, __GFP_DMA
342 * is more important.
343 */
344 return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM;
345 #else
346 return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL;
347 #endif
348 }
349
350 /*
351 * Figure out which kmalloc slab an allocation of a certain size
352 * belongs to.
353 * 0 = zero alloc
354 * 1 = 65 .. 96 bytes
355 * 2 = 129 .. 192 bytes
356 * n = 2^(n-1)+1 .. 2^n
357 */
kmalloc_index(size_t size)358 static __always_inline unsigned int kmalloc_index(size_t size)
359 {
360 if (!size)
361 return 0;
362
363 if (size <= KMALLOC_MIN_SIZE)
364 return KMALLOC_SHIFT_LOW;
365
366 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
367 return 1;
368 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
369 return 2;
370 if (size <= 8) return 3;
371 if (size <= 16) return 4;
372 if (size <= 32) return 5;
373 if (size <= 64) return 6;
374 if (size <= 128) return 7;
375 if (size <= 256) return 8;
376 if (size <= 512) return 9;
377 if (size <= 1024) return 10;
378 if (size <= 2 * 1024) return 11;
379 if (size <= 4 * 1024) return 12;
380 if (size <= 8 * 1024) return 13;
381 if (size <= 16 * 1024) return 14;
382 if (size <= 32 * 1024) return 15;
383 if (size <= 64 * 1024) return 16;
384 if (size <= 128 * 1024) return 17;
385 if (size <= 256 * 1024) return 18;
386 if (size <= 512 * 1024) return 19;
387 if (size <= 1024 * 1024) return 20;
388 if (size <= 2 * 1024 * 1024) return 21;
389 if (size <= 4 * 1024 * 1024) return 22;
390 if (size <= 8 * 1024 * 1024) return 23;
391 if (size <= 16 * 1024 * 1024) return 24;
392 if (size <= 32 * 1024 * 1024) return 25;
393 if (size <= 64 * 1024 * 1024) return 26;
394 BUG();
395
396 /* Will never be reached. Needed because the compiler may complain */
397 return -1;
398 }
399 #endif /* !CONFIG_SLOB */
400
401 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
402 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
403 void kmem_cache_free(struct kmem_cache *, void *);
404
405 /*
406 * Bulk allocation and freeing operations. These are accelerated in an
407 * allocator specific way to avoid taking locks repeatedly or building
408 * metadata structures unnecessarily.
409 *
410 * Note that interrupts must be enabled when calling these functions.
411 */
412 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
413 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
414
415 /*
416 * Caller must not use kfree_bulk() on memory not originally allocated
417 * by kmalloc(), because the SLOB allocator cannot handle this.
418 */
kfree_bulk(size_t size,void ** p)419 static __always_inline void kfree_bulk(size_t size, void **p)
420 {
421 kmem_cache_free_bulk(NULL, size, p);
422 }
423
424 #ifdef CONFIG_NUMA
425 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
426 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;
427 #else
__kmalloc_node(size_t size,gfp_t flags,int node)428 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
429 {
430 return __kmalloc(size, flags);
431 }
432
kmem_cache_alloc_node(struct kmem_cache * s,gfp_t flags,int node)433 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
434 {
435 return kmem_cache_alloc(s, flags);
436 }
437 #endif
438
439 #ifdef CONFIG_TRACING
440 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc;
441
442 #ifdef CONFIG_NUMA
443 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
444 gfp_t gfpflags,
445 int node, size_t size) __assume_slab_alignment __malloc;
446 #else
447 static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache * s,gfp_t gfpflags,int node,size_t size)448 kmem_cache_alloc_node_trace(struct kmem_cache *s,
449 gfp_t gfpflags,
450 int node, size_t size)
451 {
452 return kmem_cache_alloc_trace(s, gfpflags, size);
453 }
454 #endif /* CONFIG_NUMA */
455
456 #else /* CONFIG_TRACING */
kmem_cache_alloc_trace(struct kmem_cache * s,gfp_t flags,size_t size)457 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
458 gfp_t flags, size_t size)
459 {
460 void *ret = kmem_cache_alloc(s, flags);
461
462 ret = kasan_kmalloc(s, ret, size, flags);
463 return ret;
464 }
465
466 static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache * s,gfp_t gfpflags,int node,size_t size)467 kmem_cache_alloc_node_trace(struct kmem_cache *s,
468 gfp_t gfpflags,
469 int node, size_t size)
470 {
471 void *ret = kmem_cache_alloc_node(s, gfpflags, node);
472
473 ret = kasan_kmalloc(s, ret, size, gfpflags);
474 return ret;
475 }
476 #endif /* CONFIG_TRACING */
477
478 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
479
480 #ifdef CONFIG_TRACING
481 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
482 #else
483 static __always_inline void *
kmalloc_order_trace(size_t size,gfp_t flags,unsigned int order)484 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
485 {
486 return kmalloc_order(size, flags, order);
487 }
488 #endif
489
kmalloc_large(size_t size,gfp_t flags)490 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
491 {
492 unsigned int order = get_order(size);
493 return kmalloc_order_trace(size, flags, order);
494 }
495
496 /**
497 * kmalloc - allocate memory
498 * @size: how many bytes of memory are required.
499 * @flags: the type of memory to allocate.
500 *
501 * kmalloc is the normal method of allocating memory
502 * for objects smaller than page size in the kernel.
503 *
504 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN
505 * bytes. For @size of power of two bytes, the alignment is also guaranteed
506 * to be at least to the size.
507 *
508 * The @flags argument may be one of the GFP flags defined at
509 * include/linux/gfp.h and described at
510 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
511 *
512 * The recommended usage of the @flags is described at
513 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>`
514 *
515 * Below is a brief outline of the most useful GFP flags
516 *
517 * %GFP_KERNEL
518 * Allocate normal kernel ram. May sleep.
519 *
520 * %GFP_NOWAIT
521 * Allocation will not sleep.
522 *
523 * %GFP_ATOMIC
524 * Allocation will not sleep. May use emergency pools.
525 *
526 * %GFP_HIGHUSER
527 * Allocate memory from high memory on behalf of user.
528 *
529 * Also it is possible to set different flags by OR'ing
530 * in one or more of the following additional @flags:
531 *
532 * %__GFP_HIGH
533 * This allocation has high priority and may use emergency pools.
534 *
535 * %__GFP_NOFAIL
536 * Indicate that this allocation is in no way allowed to fail
537 * (think twice before using).
538 *
539 * %__GFP_NORETRY
540 * If memory is not immediately available,
541 * then give up at once.
542 *
543 * %__GFP_NOWARN
544 * If allocation fails, don't issue any warnings.
545 *
546 * %__GFP_RETRY_MAYFAIL
547 * Try really hard to succeed the allocation but fail
548 * eventually.
549 */
kmalloc(size_t size,gfp_t flags)550 static __always_inline void *kmalloc(size_t size, gfp_t flags)
551 {
552 if (__builtin_constant_p(size)) {
553 #ifndef CONFIG_SLOB
554 unsigned int index;
555 #endif
556 if (size > KMALLOC_MAX_CACHE_SIZE)
557 return kmalloc_large(size, flags);
558 #ifndef CONFIG_SLOB
559 index = kmalloc_index(size);
560
561 if (!index)
562 return ZERO_SIZE_PTR;
563
564 return kmem_cache_alloc_trace(
565 kmalloc_caches[kmalloc_type(flags)][index],
566 flags, size);
567 #endif
568 }
569 return __kmalloc(size, flags);
570 }
571
kmalloc_node(size_t size,gfp_t flags,int node)572 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
573 {
574 #ifndef CONFIG_SLOB
575 if (__builtin_constant_p(size) &&
576 size <= KMALLOC_MAX_CACHE_SIZE) {
577 unsigned int i = kmalloc_index(size);
578
579 if (!i)
580 return ZERO_SIZE_PTR;
581
582 return kmem_cache_alloc_node_trace(
583 kmalloc_caches[kmalloc_type(flags)][i],
584 flags, node, size);
585 }
586 #endif
587 return __kmalloc_node(size, flags, node);
588 }
589
590 /**
591 * kmalloc_array - allocate memory for an array.
592 * @n: number of elements.
593 * @size: element size.
594 * @flags: the type of memory to allocate (see kmalloc).
595 */
kmalloc_array(size_t n,size_t size,gfp_t flags)596 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
597 {
598 size_t bytes;
599
600 if (unlikely(check_mul_overflow(n, size, &bytes)))
601 return NULL;
602 if (__builtin_constant_p(n) && __builtin_constant_p(size))
603 return kmalloc(bytes, flags);
604 return __kmalloc(bytes, flags);
605 }
606
607 /**
608 * kcalloc - allocate memory for an array. The memory is set to zero.
609 * @n: number of elements.
610 * @size: element size.
611 * @flags: the type of memory to allocate (see kmalloc).
612 */
kcalloc(size_t n,size_t size,gfp_t flags)613 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
614 {
615 return kmalloc_array(n, size, flags | __GFP_ZERO);
616 }
617
618 /*
619 * kmalloc_track_caller is a special version of kmalloc that records the
620 * calling function of the routine calling it for slab leak tracking instead
621 * of just the calling function (confusing, eh?).
622 * It's useful when the call to kmalloc comes from a widely-used standard
623 * allocator where we care about the real place the memory allocation
624 * request comes from.
625 */
626 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
627 #define kmalloc_track_caller(size, flags) \
628 __kmalloc_track_caller(size, flags, _RET_IP_)
629
kmalloc_array_node(size_t n,size_t size,gfp_t flags,int node)630 static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
631 int node)
632 {
633 size_t bytes;
634
635 if (unlikely(check_mul_overflow(n, size, &bytes)))
636 return NULL;
637 if (__builtin_constant_p(n) && __builtin_constant_p(size))
638 return kmalloc_node(bytes, flags, node);
639 return __kmalloc_node(bytes, flags, node);
640 }
641
kcalloc_node(size_t n,size_t size,gfp_t flags,int node)642 static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
643 {
644 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
645 }
646
647
648 #ifdef CONFIG_NUMA
649 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
650 #define kmalloc_node_track_caller(size, flags, node) \
651 __kmalloc_node_track_caller(size, flags, node, \
652 _RET_IP_)
653
654 #else /* CONFIG_NUMA */
655
656 #define kmalloc_node_track_caller(size, flags, node) \
657 kmalloc_track_caller(size, flags)
658
659 #endif /* CONFIG_NUMA */
660
661 /*
662 * Shortcuts
663 */
kmem_cache_zalloc(struct kmem_cache * k,gfp_t flags)664 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
665 {
666 return kmem_cache_alloc(k, flags | __GFP_ZERO);
667 }
668
669 /**
670 * kzalloc - allocate memory. The memory is set to zero.
671 * @size: how many bytes of memory are required.
672 * @flags: the type of memory to allocate (see kmalloc).
673 */
kzalloc(size_t size,gfp_t flags)674 static inline void *kzalloc(size_t size, gfp_t flags)
675 {
676 return kmalloc(size, flags | __GFP_ZERO);
677 }
678
679 /**
680 * kzalloc_node - allocate zeroed memory from a particular memory node.
681 * @size: how many bytes of memory are required.
682 * @flags: the type of memory to allocate (see kmalloc).
683 * @node: memory node from which to allocate
684 */
kzalloc_node(size_t size,gfp_t flags,int node)685 static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
686 {
687 return kmalloc_node(size, flags | __GFP_ZERO, node);
688 }
689
690 unsigned int kmem_cache_size(struct kmem_cache *s);
691 void __init kmem_cache_init_late(void);
692
693 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
694 int slab_prepare_cpu(unsigned int cpu);
695 int slab_dead_cpu(unsigned int cpu);
696 #else
697 #define slab_prepare_cpu NULL
698 #define slab_dead_cpu NULL
699 #endif
700
701 #endif /* _LINUX_SLAB_H */
702