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/types.h>
17 #include <linux/workqueue.h>
18
19
20 /*
21 * Flags to pass to kmem_cache_create().
22 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
23 */
24 #define SLAB_CONSISTENCY_CHECKS 0x00000100UL /* DEBUG: Perform (expensive) checks on alloc/free */
25 #define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */
26 #define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */
27 #define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */
28 #define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */
29 #define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
30 #define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
31 /*
32 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
33 *
34 * This delays freeing the SLAB page by a grace period, it does _NOT_
35 * delay object freeing. This means that if you do kmem_cache_free()
36 * that memory location is free to be reused at any time. Thus it may
37 * be possible to see another object there in the same RCU grace period.
38 *
39 * This feature only ensures the memory location backing the object
40 * stays valid, the trick to using this is relying on an independent
41 * object validation pass. Something like:
42 *
43 * rcu_read_lock()
44 * again:
45 * obj = lockless_lookup(key);
46 * if (obj) {
47 * if (!try_get_ref(obj)) // might fail for free objects
48 * goto again;
49 *
50 * if (obj->key != key) { // not the object we expected
51 * put_ref(obj);
52 * goto again;
53 * }
54 * }
55 * rcu_read_unlock();
56 *
57 * This is useful if we need to approach a kernel structure obliquely,
58 * from its address obtained without the usual locking. We can lock
59 * the structure to stabilize it and check it's still at the given address,
60 * only if we can be sure that the memory has not been meanwhile reused
61 * for some other kind of object (which our subsystem's lock might corrupt).
62 *
63 * rcu_read_lock before reading the address, then rcu_read_unlock after
64 * taking the spinlock within the structure expected at that address.
65 *
66 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
67 */
68 #define SLAB_TYPESAFE_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
69 #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
70 #define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */
71
72 /* Flag to prevent checks on free */
73 #ifdef CONFIG_DEBUG_OBJECTS
74 # define SLAB_DEBUG_OBJECTS 0x00400000UL
75 #else
76 # define SLAB_DEBUG_OBJECTS 0x00000000UL
77 #endif
78
79 #define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */
80
81 #ifdef CONFIG_FAILSLAB
82 # define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */
83 #else
84 # define SLAB_FAILSLAB 0x00000000UL
85 #endif
86 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
87 # define SLAB_ACCOUNT 0x04000000UL /* Account to memcg */
88 #else
89 # define SLAB_ACCOUNT 0x00000000UL
90 #endif
91
92 #ifdef CONFIG_KASAN
93 #define SLAB_KASAN 0x08000000UL
94 #else
95 #define SLAB_KASAN 0x00000000UL
96 #endif
97
98 /* The following flags affect the page allocator grouping pages by mobility */
99 #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
100 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
101 /*
102 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
103 *
104 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
105 *
106 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
107 * Both make kfree a no-op.
108 */
109 #define ZERO_SIZE_PTR ((void *)16)
110
111 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
112 (unsigned long)ZERO_SIZE_PTR)
113
114 #include <linux/kmemleak.h>
115 #include <linux/kasan.h>
116
117 struct mem_cgroup;
118 /*
119 * struct kmem_cache related prototypes
120 */
121 void __init kmem_cache_init(void);
122 bool slab_is_available(void);
123
124 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
125 unsigned long,
126 void (*)(void *));
127 void kmem_cache_destroy(struct kmem_cache *);
128 int kmem_cache_shrink(struct kmem_cache *);
129
130 void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
131 void memcg_deactivate_kmem_caches(struct mem_cgroup *);
132 void memcg_destroy_kmem_caches(struct mem_cgroup *);
133
134 /*
135 * Please use this macro to create slab caches. Simply specify the
136 * name of the structure and maybe some flags that are listed above.
137 *
138 * The alignment of the struct determines object alignment. If you
139 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
140 * then the objects will be properly aligned in SMP configurations.
141 */
142 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
143 sizeof(struct __struct), __alignof__(struct __struct),\
144 (__flags), NULL)
145
146 /*
147 * Common kmalloc functions provided by all allocators
148 */
149 void * __must_check __krealloc(const void *, size_t, gfp_t);
150 void * __must_check krealloc(const void *, size_t, gfp_t);
151 void kfree(const void *);
152 void kzfree(const void *);
153 size_t ksize(const void *);
154
155 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
156 const char *__check_heap_object(const void *ptr, unsigned long n,
157 struct page *page);
158 #else
__check_heap_object(const void * ptr,unsigned long n,struct page * page)159 static inline const char *__check_heap_object(const void *ptr,
160 unsigned long n,
161 struct page *page)
162 {
163 return NULL;
164 }
165 #endif
166
167 /*
168 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
169 * alignment larger than the alignment of a 64-bit integer.
170 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
171 */
172 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
173 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
174 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
175 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
176 #else
177 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
178 #endif
179
180 /*
181 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
182 * Intended for arches that get misalignment faults even for 64 bit integer
183 * aligned buffers.
184 */
185 #ifndef ARCH_SLAB_MINALIGN
186 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
187 #endif
188
189 /*
190 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
191 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
192 * aligned pointers.
193 */
194 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
195 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
196 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
197
198 /*
199 * Kmalloc array related definitions
200 */
201
202 #ifdef CONFIG_SLAB
203 /*
204 * The largest kmalloc size supported by the SLAB allocators is
205 * 32 megabyte (2^25) or the maximum allocatable page order if that is
206 * less than 32 MB.
207 *
208 * WARNING: Its not easy to increase this value since the allocators have
209 * to do various tricks to work around compiler limitations in order to
210 * ensure proper constant folding.
211 */
212 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
213 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
214 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
215 #ifndef KMALLOC_SHIFT_LOW
216 #define KMALLOC_SHIFT_LOW 5
217 #endif
218 #endif
219
220 #ifdef CONFIG_SLUB
221 /*
222 * SLUB directly allocates requests fitting in to an order-1 page
223 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
224 */
225 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
226 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
227 #ifndef KMALLOC_SHIFT_LOW
228 #define KMALLOC_SHIFT_LOW 3
229 #endif
230 #endif
231
232 #ifdef CONFIG_SLOB
233 /*
234 * SLOB passes all requests larger than one page to the page allocator.
235 * No kmalloc array is necessary since objects of different sizes can
236 * be allocated from the same page.
237 */
238 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
239 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
240 #ifndef KMALLOC_SHIFT_LOW
241 #define KMALLOC_SHIFT_LOW 3
242 #endif
243 #endif
244
245 /* Maximum allocatable size */
246 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
247 /* Maximum size for which we actually use a slab cache */
248 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
249 /* Maximum order allocatable via the slab allocagtor */
250 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
251
252 /*
253 * Kmalloc subsystem.
254 */
255 #ifndef KMALLOC_MIN_SIZE
256 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
257 #endif
258
259 /*
260 * This restriction comes from byte sized index implementation.
261 * Page size is normally 2^12 bytes and, in this case, if we want to use
262 * byte sized index which can represent 2^8 entries, the size of the object
263 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
264 * If minimum size of kmalloc is less than 16, we use it as minimum object
265 * size and give up to use byte sized index.
266 */
267 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
268 (KMALLOC_MIN_SIZE) : 16)
269
270 #ifndef CONFIG_SLOB
271 extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
272 #ifdef CONFIG_ZONE_DMA
273 extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
274 #endif
275
276 /*
277 * Figure out which kmalloc slab an allocation of a certain size
278 * belongs to.
279 * 0 = zero alloc
280 * 1 = 65 .. 96 bytes
281 * 2 = 129 .. 192 bytes
282 * n = 2^(n-1)+1 .. 2^n
283 */
kmalloc_index(size_t size)284 static __always_inline int kmalloc_index(size_t size)
285 {
286 if (!size)
287 return 0;
288
289 if (size <= KMALLOC_MIN_SIZE)
290 return KMALLOC_SHIFT_LOW;
291
292 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
293 return 1;
294 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
295 return 2;
296 if (size <= 8) return 3;
297 if (size <= 16) return 4;
298 if (size <= 32) return 5;
299 if (size <= 64) return 6;
300 if (size <= 128) return 7;
301 if (size <= 256) return 8;
302 if (size <= 512) return 9;
303 if (size <= 1024) return 10;
304 if (size <= 2 * 1024) return 11;
305 if (size <= 4 * 1024) return 12;
306 if (size <= 8 * 1024) return 13;
307 if (size <= 16 * 1024) return 14;
308 if (size <= 32 * 1024) return 15;
309 if (size <= 64 * 1024) return 16;
310 if (size <= 128 * 1024) return 17;
311 if (size <= 256 * 1024) return 18;
312 if (size <= 512 * 1024) return 19;
313 if (size <= 1024 * 1024) return 20;
314 if (size <= 2 * 1024 * 1024) return 21;
315 if (size <= 4 * 1024 * 1024) return 22;
316 if (size <= 8 * 1024 * 1024) return 23;
317 if (size <= 16 * 1024 * 1024) return 24;
318 if (size <= 32 * 1024 * 1024) return 25;
319 if (size <= 64 * 1024 * 1024) return 26;
320 BUG();
321
322 /* Will never be reached. Needed because the compiler may complain */
323 return -1;
324 }
325 #endif /* !CONFIG_SLOB */
326
327 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
328 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
329 void kmem_cache_free(struct kmem_cache *, void *);
330
331 /*
332 * Bulk allocation and freeing operations. These are accelerated in an
333 * allocator specific way to avoid taking locks repeatedly or building
334 * metadata structures unnecessarily.
335 *
336 * Note that interrupts must be enabled when calling these functions.
337 */
338 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
339 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
340
341 /*
342 * Caller must not use kfree_bulk() on memory not originally allocated
343 * by kmalloc(), because the SLOB allocator cannot handle this.
344 */
kfree_bulk(size_t size,void ** p)345 static __always_inline void kfree_bulk(size_t size, void **p)
346 {
347 kmem_cache_free_bulk(NULL, size, p);
348 }
349
350 #ifdef CONFIG_NUMA
351 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
352 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;
353 #else
__kmalloc_node(size_t size,gfp_t flags,int node)354 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
355 {
356 return __kmalloc(size, flags);
357 }
358
kmem_cache_alloc_node(struct kmem_cache * s,gfp_t flags,int node)359 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
360 {
361 return kmem_cache_alloc(s, flags);
362 }
363 #endif
364
365 #ifdef CONFIG_TRACING
366 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc;
367
368 #ifdef CONFIG_NUMA
369 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
370 gfp_t gfpflags,
371 int node, size_t size) __assume_slab_alignment __malloc;
372 #else
373 static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache * s,gfp_t gfpflags,int node,size_t size)374 kmem_cache_alloc_node_trace(struct kmem_cache *s,
375 gfp_t gfpflags,
376 int node, size_t size)
377 {
378 return kmem_cache_alloc_trace(s, gfpflags, size);
379 }
380 #endif /* CONFIG_NUMA */
381
382 #else /* CONFIG_TRACING */
kmem_cache_alloc_trace(struct kmem_cache * s,gfp_t flags,size_t size)383 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
384 gfp_t flags, size_t size)
385 {
386 void *ret = kmem_cache_alloc(s, flags);
387
388 kasan_kmalloc(s, ret, size, flags);
389 return ret;
390 }
391
392 static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache * s,gfp_t gfpflags,int node,size_t size)393 kmem_cache_alloc_node_trace(struct kmem_cache *s,
394 gfp_t gfpflags,
395 int node, size_t size)
396 {
397 void *ret = kmem_cache_alloc_node(s, gfpflags, node);
398
399 kasan_kmalloc(s, ret, size, gfpflags);
400 return ret;
401 }
402 #endif /* CONFIG_TRACING */
403
404 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
405
406 #ifdef CONFIG_TRACING
407 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
408 #else
409 static __always_inline void *
kmalloc_order_trace(size_t size,gfp_t flags,unsigned int order)410 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
411 {
412 return kmalloc_order(size, flags, order);
413 }
414 #endif
415
kmalloc_large(size_t size,gfp_t flags)416 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
417 {
418 unsigned int order = get_order(size);
419 return kmalloc_order_trace(size, flags, order);
420 }
421
422 /**
423 * kmalloc - allocate memory
424 * @size: how many bytes of memory are required.
425 * @flags: the type of memory to allocate.
426 *
427 * kmalloc is the normal method of allocating memory
428 * for objects smaller than page size in the kernel.
429 *
430 * The @flags argument may be one of:
431 *
432 * %GFP_USER - Allocate memory on behalf of user. May sleep.
433 *
434 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
435 *
436 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
437 * For example, use this inside interrupt handlers.
438 *
439 * %GFP_HIGHUSER - Allocate pages from high memory.
440 *
441 * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
442 *
443 * %GFP_NOFS - Do not make any fs calls while trying to get memory.
444 *
445 * %GFP_NOWAIT - Allocation will not sleep.
446 *
447 * %__GFP_THISNODE - Allocate node-local memory only.
448 *
449 * %GFP_DMA - Allocation suitable for DMA.
450 * Should only be used for kmalloc() caches. Otherwise, use a
451 * slab created with SLAB_DMA.
452 *
453 * Also it is possible to set different flags by OR'ing
454 * in one or more of the following additional @flags:
455 *
456 * %__GFP_COLD - Request cache-cold pages instead of
457 * trying to return cache-warm pages.
458 *
459 * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
460 *
461 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
462 * (think twice before using).
463 *
464 * %__GFP_NORETRY - If memory is not immediately available,
465 * then give up at once.
466 *
467 * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
468 *
469 * %__GFP_RETRY_MAYFAIL - Try really hard to succeed the allocation but fail
470 * eventually.
471 *
472 * There are other flags available as well, but these are not intended
473 * for general use, and so are not documented here. For a full list of
474 * potential flags, always refer to linux/gfp.h.
475 */
kmalloc(size_t size,gfp_t flags)476 static __always_inline void *kmalloc(size_t size, gfp_t flags)
477 {
478 if (__builtin_constant_p(size)) {
479 if (size > KMALLOC_MAX_CACHE_SIZE)
480 return kmalloc_large(size, flags);
481 #ifndef CONFIG_SLOB
482 if (!(flags & GFP_DMA)) {
483 int index = kmalloc_index(size);
484
485 if (!index)
486 return ZERO_SIZE_PTR;
487
488 return kmem_cache_alloc_trace(kmalloc_caches[index],
489 flags, size);
490 }
491 #endif
492 }
493 return __kmalloc(size, flags);
494 }
495
496 /*
497 * Determine size used for the nth kmalloc cache.
498 * return size or 0 if a kmalloc cache for that
499 * size does not exist
500 */
kmalloc_size(int n)501 static __always_inline int kmalloc_size(int n)
502 {
503 #ifndef CONFIG_SLOB
504 if (n > 2)
505 return 1 << n;
506
507 if (n == 1 && KMALLOC_MIN_SIZE <= 32)
508 return 96;
509
510 if (n == 2 && KMALLOC_MIN_SIZE <= 64)
511 return 192;
512 #endif
513 return 0;
514 }
515
kmalloc_node(size_t size,gfp_t flags,int node)516 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
517 {
518 #ifndef CONFIG_SLOB
519 if (__builtin_constant_p(size) &&
520 size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
521 int i = kmalloc_index(size);
522
523 if (!i)
524 return ZERO_SIZE_PTR;
525
526 return kmem_cache_alloc_node_trace(kmalloc_caches[i],
527 flags, node, size);
528 }
529 #endif
530 return __kmalloc_node(size, flags, node);
531 }
532
533 struct memcg_cache_array {
534 struct rcu_head rcu;
535 struct kmem_cache *entries[0];
536 };
537
538 /*
539 * This is the main placeholder for memcg-related information in kmem caches.
540 * Both the root cache and the child caches will have it. For the root cache,
541 * this will hold a dynamically allocated array large enough to hold
542 * information about the currently limited memcgs in the system. To allow the
543 * array to be accessed without taking any locks, on relocation we free the old
544 * version only after a grace period.
545 *
546 * Root and child caches hold different metadata.
547 *
548 * @root_cache: Common to root and child caches. NULL for root, pointer to
549 * the root cache for children.
550 *
551 * The following fields are specific to root caches.
552 *
553 * @memcg_caches: kmemcg ID indexed table of child caches. This table is
554 * used to index child cachces during allocation and cleared
555 * early during shutdown.
556 *
557 * @root_caches_node: List node for slab_root_caches list.
558 *
559 * @children: List of all child caches. While the child caches are also
560 * reachable through @memcg_caches, a child cache remains on
561 * this list until it is actually destroyed.
562 *
563 * The following fields are specific to child caches.
564 *
565 * @memcg: Pointer to the memcg this cache belongs to.
566 *
567 * @children_node: List node for @root_cache->children list.
568 *
569 * @kmem_caches_node: List node for @memcg->kmem_caches list.
570 */
571 struct memcg_cache_params {
572 struct kmem_cache *root_cache;
573 union {
574 struct {
575 struct memcg_cache_array __rcu *memcg_caches;
576 struct list_head __root_caches_node;
577 struct list_head children;
578 };
579 struct {
580 struct mem_cgroup *memcg;
581 struct list_head children_node;
582 struct list_head kmem_caches_node;
583
584 void (*deact_fn)(struct kmem_cache *);
585 union {
586 struct rcu_head deact_rcu_head;
587 struct work_struct deact_work;
588 };
589 };
590 };
591 };
592
593 int memcg_update_all_caches(int num_memcgs);
594
595 /**
596 * kmalloc_array - allocate memory for an array.
597 * @n: number of elements.
598 * @size: element size.
599 * @flags: the type of memory to allocate (see kmalloc).
600 */
kmalloc_array(size_t n,size_t size,gfp_t flags)601 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
602 {
603 if (size != 0 && n > SIZE_MAX / size)
604 return NULL;
605 if (__builtin_constant_p(n) && __builtin_constant_p(size))
606 return kmalloc(n * size, flags);
607 return __kmalloc(n * size, flags);
608 }
609
610 /**
611 * kcalloc - allocate memory for an array. The memory is set to zero.
612 * @n: number of elements.
613 * @size: element size.
614 * @flags: the type of memory to allocate (see kmalloc).
615 */
kcalloc(size_t n,size_t size,gfp_t flags)616 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
617 {
618 return kmalloc_array(n, size, flags | __GFP_ZERO);
619 }
620
621 /*
622 * kmalloc_track_caller is a special version of kmalloc that records the
623 * calling function of the routine calling it for slab leak tracking instead
624 * of just the calling function (confusing, eh?).
625 * It's useful when the call to kmalloc comes from a widely-used standard
626 * allocator where we care about the real place the memory allocation
627 * request comes from.
628 */
629 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
630 #define kmalloc_track_caller(size, flags) \
631 __kmalloc_track_caller(size, flags, _RET_IP_)
632
633 #ifdef CONFIG_NUMA
634 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
635 #define kmalloc_node_track_caller(size, flags, node) \
636 __kmalloc_node_track_caller(size, flags, node, \
637 _RET_IP_)
638
639 #else /* CONFIG_NUMA */
640
641 #define kmalloc_node_track_caller(size, flags, node) \
642 kmalloc_track_caller(size, flags)
643
644 #endif /* CONFIG_NUMA */
645
646 /*
647 * Shortcuts
648 */
kmem_cache_zalloc(struct kmem_cache * k,gfp_t flags)649 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
650 {
651 return kmem_cache_alloc(k, flags | __GFP_ZERO);
652 }
653
654 /**
655 * kzalloc - allocate memory. The memory is set to zero.
656 * @size: how many bytes of memory are required.
657 * @flags: the type of memory to allocate (see kmalloc).
658 */
kzalloc(size_t size,gfp_t flags)659 static inline void *kzalloc(size_t size, gfp_t flags)
660 {
661 return kmalloc(size, flags | __GFP_ZERO);
662 }
663
664 /**
665 * kzalloc_node - allocate zeroed memory from a particular memory node.
666 * @size: how many bytes of memory are required.
667 * @flags: the type of memory to allocate (see kmalloc).
668 * @node: memory node from which to allocate
669 */
kzalloc_node(size_t size,gfp_t flags,int node)670 static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
671 {
672 return kmalloc_node(size, flags | __GFP_ZERO, node);
673 }
674
675 unsigned int kmem_cache_size(struct kmem_cache *s);
676 void __init kmem_cache_init_late(void);
677
678 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
679 int slab_prepare_cpu(unsigned int cpu);
680 int slab_dead_cpu(unsigned int cpu);
681 #else
682 #define slab_prepare_cpu NULL
683 #define slab_dead_cpu NULL
684 #endif
685
686 #endif /* _LINUX_SLAB_H */
687