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 #include <linux/cleanup.h>
21
22
23 /*
24 * Flags to pass to kmem_cache_create().
25 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
26 */
27 /* DEBUG: Perform (expensive) checks on alloc/free */
28 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U)
29 /* DEBUG: Red zone objs in a cache */
30 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U)
31 /* DEBUG: Poison objects */
32 #define SLAB_POISON ((slab_flags_t __force)0x00000800U)
33 /* Indicate a kmalloc slab */
34 #define SLAB_KMALLOC ((slab_flags_t __force)0x00001000U)
35 /* Align objs on cache lines */
36 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U)
37 /* Use GFP_DMA memory */
38 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U)
39 /* Use GFP_DMA32 memory */
40 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U)
41 /* DEBUG: Store the last owner for bug hunting */
42 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U)
43 /* Panic if kmem_cache_create() fails */
44 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U)
45 /*
46 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
47 *
48 * This delays freeing the SLAB page by a grace period, it does _NOT_
49 * delay object freeing. This means that if you do kmem_cache_free()
50 * that memory location is free to be reused at any time. Thus it may
51 * be possible to see another object there in the same RCU grace period.
52 *
53 * This feature only ensures the memory location backing the object
54 * stays valid, the trick to using this is relying on an independent
55 * object validation pass. Something like:
56 *
57 * rcu_read_lock()
58 * again:
59 * obj = lockless_lookup(key);
60 * if (obj) {
61 * if (!try_get_ref(obj)) // might fail for free objects
62 * goto again;
63 *
64 * if (obj->key != key) { // not the object we expected
65 * put_ref(obj);
66 * goto again;
67 * }
68 * }
69 * rcu_read_unlock();
70 *
71 * This is useful if we need to approach a kernel structure obliquely,
72 * from its address obtained without the usual locking. We can lock
73 * the structure to stabilize it and check it's still at the given address,
74 * only if we can be sure that the memory has not been meanwhile reused
75 * for some other kind of object (which our subsystem's lock might corrupt).
76 *
77 * rcu_read_lock before reading the address, then rcu_read_unlock after
78 * taking the spinlock within the structure expected at that address.
79 *
80 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
81 */
82 /* Defer freeing slabs to RCU */
83 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U)
84 /* Spread some memory over cpuset */
85 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U)
86 /* Trace allocations and frees */
87 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U)
88
89 /* Flag to prevent checks on free */
90 #ifdef CONFIG_DEBUG_OBJECTS
91 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U)
92 #else
93 # define SLAB_DEBUG_OBJECTS 0
94 #endif
95
96 /* Avoid kmemleak tracing */
97 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U)
98
99 /* Fault injection mark */
100 #ifdef CONFIG_FAILSLAB
101 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U)
102 #else
103 # define SLAB_FAILSLAB 0
104 #endif
105 /* Account to memcg */
106 #ifdef CONFIG_MEMCG_KMEM
107 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U)
108 #else
109 # define SLAB_ACCOUNT 0
110 #endif
111
112 #ifdef CONFIG_KASAN_GENERIC
113 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U)
114 #else
115 #define SLAB_KASAN 0
116 #endif
117
118 /*
119 * Ignore user specified debugging flags.
120 * Intended for caches created for self-tests so they have only flags
121 * specified in the code and other flags are ignored.
122 */
123 #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U)
124
125 #ifdef CONFIG_KFENCE
126 #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U)
127 #else
128 #define SLAB_SKIP_KFENCE 0
129 #endif
130
131 /* The following flags affect the page allocator grouping pages by mobility */
132 /* Objects are reclaimable */
133 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U)
134 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
135
136 /*
137 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
138 *
139 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
140 *
141 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
142 * Both make kfree a no-op.
143 */
144 #define ZERO_SIZE_PTR ((void *)16)
145
146 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
147 (unsigned long)ZERO_SIZE_PTR)
148
149 #include <linux/kasan.h>
150
151 struct list_lru;
152 struct mem_cgroup;
153 /*
154 * struct kmem_cache related prototypes
155 */
156 void __init kmem_cache_init(void);
157 bool slab_is_available(void);
158
159 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
160 unsigned int align, slab_flags_t flags,
161 void (*ctor)(void *));
162 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
163 unsigned int size, unsigned int align,
164 slab_flags_t flags,
165 unsigned int useroffset, unsigned int usersize,
166 void (*ctor)(void *));
167 void kmem_cache_destroy(struct kmem_cache *s);
168 int kmem_cache_shrink(struct kmem_cache *s);
169
170 /*
171 * Please use this macro to create slab caches. Simply specify the
172 * name of the structure and maybe some flags that are listed above.
173 *
174 * The alignment of the struct determines object alignment. If you
175 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
176 * then the objects will be properly aligned in SMP configurations.
177 */
178 #define KMEM_CACHE(__struct, __flags) \
179 kmem_cache_create(#__struct, sizeof(struct __struct), \
180 __alignof__(struct __struct), (__flags), NULL)
181
182 /*
183 * To whitelist a single field for copying to/from usercopy, use this
184 * macro instead for KMEM_CACHE() above.
185 */
186 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
187 kmem_cache_create_usercopy(#__struct, \
188 sizeof(struct __struct), \
189 __alignof__(struct __struct), (__flags), \
190 offsetof(struct __struct, __field), \
191 sizeof_field(struct __struct, __field), NULL)
192
193 /*
194 * Common kmalloc functions provided by all allocators
195 */
196 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2);
197 void kfree(const void *objp);
198 void kfree_sensitive(const void *objp);
199 size_t __ksize(const void *objp);
200
201 DEFINE_FREE(kfree, void *, if (_T) kfree(_T))
202
203 /**
204 * ksize - Report actual allocation size of associated object
205 *
206 * @objp: Pointer returned from a prior kmalloc()-family allocation.
207 *
208 * This should not be used for writing beyond the originally requested
209 * allocation size. Either use krealloc() or round up the allocation size
210 * with kmalloc_size_roundup() prior to allocation. If this is used to
211 * access beyond the originally requested allocation size, UBSAN_BOUNDS
212 * and/or FORTIFY_SOURCE may trip, since they only know about the
213 * originally allocated size via the __alloc_size attribute.
214 */
215 size_t ksize(const void *objp);
216
217 #ifdef CONFIG_PRINTK
218 bool kmem_valid_obj(void *object);
219 void kmem_dump_obj(void *object);
220 #endif
221
222 /*
223 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
224 * alignment larger than the alignment of a 64-bit integer.
225 * Setting ARCH_DMA_MINALIGN in arch headers allows that.
226 */
227 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
228 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
229 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
230 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
231 #else
232 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
233 #endif
234
235 /*
236 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
237 * Intended for arches that get misalignment faults even for 64 bit integer
238 * aligned buffers.
239 */
240 #ifndef ARCH_SLAB_MINALIGN
241 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
242 #endif
243
244 /*
245 * Arches can define this function if they want to decide the minimum slab
246 * alignment at runtime. The value returned by the function must be a power
247 * of two and >= ARCH_SLAB_MINALIGN.
248 */
249 #ifndef arch_slab_minalign
arch_slab_minalign(void)250 static inline unsigned int arch_slab_minalign(void)
251 {
252 return ARCH_SLAB_MINALIGN;
253 }
254 #endif
255
256 /*
257 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN.
258 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN
259 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment.
260 */
261 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
262 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
263 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
264
265 /*
266 * Kmalloc array related definitions
267 */
268
269 #ifdef CONFIG_SLAB
270 /*
271 * SLAB and SLUB directly allocates requests fitting in to an order-1 page
272 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
273 */
274 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
275 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
276 #ifndef KMALLOC_SHIFT_LOW
277 #define KMALLOC_SHIFT_LOW 5
278 #endif
279 #endif
280
281 #ifdef CONFIG_SLUB
282 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
283 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
284 #ifndef KMALLOC_SHIFT_LOW
285 #define KMALLOC_SHIFT_LOW 3
286 #endif
287 #endif
288
289 #ifdef CONFIG_SLOB
290 /*
291 * SLOB passes all requests larger than one page to the page allocator.
292 * No kmalloc array is necessary since objects of different sizes can
293 * be allocated from the same page.
294 */
295 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
296 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
297 #ifndef KMALLOC_SHIFT_LOW
298 #define KMALLOC_SHIFT_LOW 3
299 #endif
300 #endif
301
302 /* Maximum allocatable size */
303 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
304 /* Maximum size for which we actually use a slab cache */
305 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
306 /* Maximum order allocatable via the slab allocator */
307 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
308
309 /*
310 * Kmalloc subsystem.
311 */
312 #ifndef KMALLOC_MIN_SIZE
313 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
314 #endif
315
316 /*
317 * This restriction comes from byte sized index implementation.
318 * Page size is normally 2^12 bytes and, in this case, if we want to use
319 * byte sized index which can represent 2^8 entries, the size of the object
320 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
321 * If minimum size of kmalloc is less than 16, we use it as minimum object
322 * size and give up to use byte sized index.
323 */
324 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
325 (KMALLOC_MIN_SIZE) : 16)
326
327 /*
328 * Whenever changing this, take care of that kmalloc_type() and
329 * create_kmalloc_caches() still work as intended.
330 *
331 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP
332 * is for accounted but unreclaimable and non-dma objects. All the other
333 * kmem caches can have both accounted and unaccounted objects.
334 */
335 enum kmalloc_cache_type {
336 KMALLOC_NORMAL = 0,
337 #ifndef CONFIG_ZONE_DMA
338 KMALLOC_DMA = KMALLOC_NORMAL,
339 #endif
340 #ifndef CONFIG_MEMCG_KMEM
341 KMALLOC_CGROUP = KMALLOC_NORMAL,
342 #else
343 KMALLOC_CGROUP,
344 #endif
345 KMALLOC_RECLAIM,
346 #ifdef CONFIG_ZONE_DMA
347 KMALLOC_DMA,
348 #endif
349 NR_KMALLOC_TYPES
350 };
351
352 #ifndef CONFIG_SLOB
353 extern struct kmem_cache *
354 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
355
356 /*
357 * Define gfp bits that should not be set for KMALLOC_NORMAL.
358 */
359 #define KMALLOC_NOT_NORMAL_BITS \
360 (__GFP_RECLAIMABLE | \
361 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \
362 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0))
363
kmalloc_type(gfp_t flags)364 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
365 {
366 /*
367 * The most common case is KMALLOC_NORMAL, so test for it
368 * with a single branch for all the relevant flags.
369 */
370 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0))
371 return KMALLOC_NORMAL;
372
373 /*
374 * At least one of the flags has to be set. Their priorities in
375 * decreasing order are:
376 * 1) __GFP_DMA
377 * 2) __GFP_RECLAIMABLE
378 * 3) __GFP_ACCOUNT
379 */
380 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
381 return KMALLOC_DMA;
382 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE))
383 return KMALLOC_RECLAIM;
384 else
385 return KMALLOC_CGROUP;
386 }
387
388 /*
389 * Figure out which kmalloc slab an allocation of a certain size
390 * belongs to.
391 * 0 = zero alloc
392 * 1 = 65 .. 96 bytes
393 * 2 = 129 .. 192 bytes
394 * n = 2^(n-1)+1 .. 2^n
395 *
396 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
397 * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
398 * Callers where !size_is_constant should only be test modules, where runtime
399 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab().
400 */
__kmalloc_index(size_t size,bool size_is_constant)401 static __always_inline unsigned int __kmalloc_index(size_t size,
402 bool size_is_constant)
403 {
404 if (!size)
405 return 0;
406
407 if (size <= KMALLOC_MIN_SIZE)
408 return KMALLOC_SHIFT_LOW;
409
410 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
411 return 1;
412 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
413 return 2;
414 if (size <= 8) return 3;
415 if (size <= 16) return 4;
416 if (size <= 32) return 5;
417 if (size <= 64) return 6;
418 if (size <= 128) return 7;
419 if (size <= 256) return 8;
420 if (size <= 512) return 9;
421 if (size <= 1024) return 10;
422 if (size <= 2 * 1024) return 11;
423 if (size <= 4 * 1024) return 12;
424 if (size <= 8 * 1024) return 13;
425 if (size <= 16 * 1024) return 14;
426 if (size <= 32 * 1024) return 15;
427 if (size <= 64 * 1024) return 16;
428 if (size <= 128 * 1024) return 17;
429 if (size <= 256 * 1024) return 18;
430 if (size <= 512 * 1024) return 19;
431 if (size <= 1024 * 1024) return 20;
432 if (size <= 2 * 1024 * 1024) return 21;
433
434 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
435 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
436 else
437 BUG();
438
439 /* Will never be reached. Needed because the compiler may complain */
440 return -1;
441 }
442 static_assert(PAGE_SHIFT <= 20);
443 #define kmalloc_index(s) __kmalloc_index(s, true)
444 #endif /* !CONFIG_SLOB */
445
446 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
447 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc;
448 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
449 gfp_t gfpflags) __assume_slab_alignment __malloc;
450 void kmem_cache_free(struct kmem_cache *s, void *objp);
451
452 /*
453 * Bulk allocation and freeing operations. These are accelerated in an
454 * allocator specific way to avoid taking locks repeatedly or building
455 * metadata structures unnecessarily.
456 *
457 * Note that interrupts must be enabled when calling these functions.
458 */
459 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
460 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p);
461
462 /*
463 * Caller must not use kfree_bulk() on memory not originally allocated
464 * by kmalloc(), because the SLOB allocator cannot handle this.
465 */
kfree_bulk(size_t size,void ** p)466 static __always_inline void kfree_bulk(size_t size, void **p)
467 {
468 kmem_cache_free_bulk(NULL, size, p);
469 }
470
471 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
472 __alloc_size(1);
473 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment
474 __malloc;
475
476 void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size)
477 __assume_kmalloc_alignment __alloc_size(3);
478
479 void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
480 int node, size_t size) __assume_kmalloc_alignment
481 __alloc_size(4);
482 void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment
483 __alloc_size(1);
484
485 void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment
486 __alloc_size(1);
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 *
496 * 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.
499 *
500 * 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>`
503 *
504 * The recommended usage of the @flags is described at
505 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>`
506 *
507 * Below is a brief outline of the most useful GFP flags
508 *
509 * %GFP_KERNEL
510 * Allocate normal kernel ram. May sleep.
511 *
512 * %GFP_NOWAIT
513 * Allocation will not sleep.
514 *
515 * %GFP_ATOMIC
516 * Allocation will not sleep. May use emergency pools.
517 *
518 * %GFP_HIGHUSER
519 * Allocate memory from high memory on behalf of user.
520 *
521 * Also it is possible to set different flags by OR'ing
522 * in one or more of the following additional @flags:
523 *
524 * %__GFP_HIGH
525 * This allocation has high priority and may use emergency pools.
526 *
527 * %__GFP_NOFAIL
528 * Indicate that this allocation is in no way allowed to fail
529 * (think twice before using).
530 *
531 * %__GFP_NORETRY
532 * If memory is not immediately available,
533 * then give up at once.
534 *
535 * %__GFP_NOWARN
536 * If allocation fails, don't issue any warnings.
537 *
538 * %__GFP_RETRY_MAYFAIL
539 * Try really hard to succeed the allocation but fail
540 * eventually.
541 */
kmalloc(size_t size,gfp_t flags)542 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
543 {
544 if (__builtin_constant_p(size)) {
545 #ifndef CONFIG_SLOB
546 unsigned int index;
547 #endif
548 if (size > KMALLOC_MAX_CACHE_SIZE)
549 return kmalloc_large(size, flags);
550 #ifndef CONFIG_SLOB
551 index = kmalloc_index(size);
552
553 if (!index)
554 return ZERO_SIZE_PTR;
555
556 return kmalloc_trace(
557 kmalloc_caches[kmalloc_type(flags)][index],
558 flags, size);
559 #endif
560 }
561 return __kmalloc(size, flags);
562 }
563
564 #ifndef CONFIG_SLOB
kmalloc_node(size_t size,gfp_t flags,int node)565 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
566 {
567 if (__builtin_constant_p(size)) {
568 unsigned int index;
569
570 if (size > KMALLOC_MAX_CACHE_SIZE)
571 return kmalloc_large_node(size, flags, node);
572
573 index = kmalloc_index(size);
574
575 if (!index)
576 return ZERO_SIZE_PTR;
577
578 return kmalloc_node_trace(
579 kmalloc_caches[kmalloc_type(flags)][index],
580 flags, node, size);
581 }
582 return __kmalloc_node(size, flags, node);
583 }
584 #else
kmalloc_node(size_t size,gfp_t flags,int node)585 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
586 {
587 if (__builtin_constant_p(size) && size > KMALLOC_MAX_CACHE_SIZE)
588 return kmalloc_large_node(size, flags, node);
589
590 return __kmalloc_node(size, flags, node);
591 }
592 #endif
593
594 /**
595 * kmalloc_array - allocate memory for an array.
596 * @n: number of elements.
597 * @size: element size.
598 * @flags: the type of memory to allocate (see kmalloc).
599 */
kmalloc_array(size_t n,size_t size,gfp_t flags)600 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags)
601 {
602 size_t bytes;
603
604 if (unlikely(check_mul_overflow(n, size, &bytes)))
605 return NULL;
606 if (__builtin_constant_p(n) && __builtin_constant_p(size))
607 return kmalloc(bytes, flags);
608 return __kmalloc(bytes, flags);
609 }
610
611 /**
612 * krealloc_array - reallocate memory for an array.
613 * @p: pointer to the memory chunk to reallocate
614 * @new_n: new number of elements to alloc
615 * @new_size: new size of a single member of the array
616 * @flags: the type of memory to allocate (see kmalloc)
617 */
krealloc_array(void * p,size_t new_n,size_t new_size,gfp_t flags)618 static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p,
619 size_t new_n,
620 size_t new_size,
621 gfp_t flags)
622 {
623 size_t bytes;
624
625 if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
626 return NULL;
627
628 return krealloc(p, bytes, flags);
629 }
630
631 /**
632 * kcalloc - allocate memory for an array. The memory is set to zero.
633 * @n: number of elements.
634 * @size: element size.
635 * @flags: the type of memory to allocate (see kmalloc).
636 */
kcalloc(size_t n,size_t size,gfp_t flags)637 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags)
638 {
639 return kmalloc_array(n, size, flags | __GFP_ZERO);
640 }
641
642 void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node,
643 unsigned long caller);
644 #define kmalloc_node_track_caller(size, flags, node) \
645 __kmalloc_node_track_caller(size, flags, node, \
646 _RET_IP_)
647
648 /*
649 * kmalloc_track_caller is a special version of kmalloc that records the
650 * calling function of the routine calling it for slab leak tracking instead
651 * of just the calling function (confusing, eh?).
652 * It's useful when the call to kmalloc comes from a widely-used standard
653 * allocator where we care about the real place the memory allocation
654 * request comes from.
655 */
656 #define kmalloc_track_caller(size, flags) \
657 __kmalloc_node_track_caller(size, flags, \
658 NUMA_NO_NODE, _RET_IP_)
659
kmalloc_array_node(size_t n,size_t size,gfp_t flags,int node)660 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
661 int node)
662 {
663 size_t bytes;
664
665 if (unlikely(check_mul_overflow(n, size, &bytes)))
666 return NULL;
667 if (__builtin_constant_p(n) && __builtin_constant_p(size))
668 return kmalloc_node(bytes, flags, node);
669 return __kmalloc_node(bytes, flags, node);
670 }
671
kcalloc_node(size_t n,size_t size,gfp_t flags,int node)672 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
673 {
674 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
675 }
676
677 /*
678 * Shortcuts
679 */
kmem_cache_zalloc(struct kmem_cache * k,gfp_t flags)680 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
681 {
682 return kmem_cache_alloc(k, flags | __GFP_ZERO);
683 }
684
685 /**
686 * kzalloc - allocate memory. The memory is set to zero.
687 * @size: how many bytes of memory are required.
688 * @flags: the type of memory to allocate (see kmalloc).
689 */
kzalloc(size_t size,gfp_t flags)690 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags)
691 {
692 return kmalloc(size, flags | __GFP_ZERO);
693 }
694
695 /**
696 * kzalloc_node - allocate zeroed memory from a particular memory node.
697 * @size: how many bytes of memory are required.
698 * @flags: the type of memory to allocate (see kmalloc).
699 * @node: memory node from which to allocate
700 */
kzalloc_node(size_t size,gfp_t flags,int node)701 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node)
702 {
703 return kmalloc_node(size, flags | __GFP_ZERO, node);
704 }
705
706 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
kvmalloc(size_t size,gfp_t flags)707 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
708 {
709 return kvmalloc_node(size, flags, NUMA_NO_NODE);
710 }
kvzalloc_node(size_t size,gfp_t flags,int node)711 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
712 {
713 return kvmalloc_node(size, flags | __GFP_ZERO, node);
714 }
kvzalloc(size_t size,gfp_t flags)715 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
716 {
717 return kvmalloc(size, flags | __GFP_ZERO);
718 }
719
kvmalloc_array(size_t n,size_t size,gfp_t flags)720 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
721 {
722 size_t bytes;
723
724 if (unlikely(check_mul_overflow(n, size, &bytes)))
725 return NULL;
726
727 return kvmalloc(bytes, flags);
728 }
729
kvcalloc(size_t n,size_t size,gfp_t flags)730 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
731 {
732 return kvmalloc_array(n, size, flags | __GFP_ZERO);
733 }
734
735 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
736 __realloc_size(3);
737 extern void kvfree(const void *addr);
738 extern void kvfree_sensitive(const void *addr, size_t len);
739
740 unsigned int kmem_cache_size(struct kmem_cache *s);
741
742 /**
743 * kmalloc_size_roundup - Report allocation bucket size for the given size
744 *
745 * @size: Number of bytes to round up from.
746 *
747 * This returns the number of bytes that would be available in a kmalloc()
748 * allocation of @size bytes. For example, a 126 byte request would be
749 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly
750 * for the general-purpose kmalloc()-based allocations, and is not for the
751 * pre-sized kmem_cache_alloc()-based allocations.)
752 *
753 * Use this to kmalloc() the full bucket size ahead of time instead of using
754 * ksize() to query the size after an allocation.
755 */
756 size_t kmalloc_size_roundup(size_t size);
757
758 void __init kmem_cache_init_late(void);
759
760 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
761 int slab_prepare_cpu(unsigned int cpu);
762 int slab_dead_cpu(unsigned int cpu);
763 #else
764 #define slab_prepare_cpu NULL
765 #define slab_dead_cpu NULL
766 #endif
767
768 #endif /* _LINUX_SLAB_H */
769