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 /* Indicate a kmalloc slab */
33 #define SLAB_KMALLOC ((slab_flags_t __force)0x00001000U)
34 /* Align objs on cache lines */
35 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U)
36 /* Use GFP_DMA memory */
37 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U)
38 /* Use GFP_DMA32 memory */
39 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U)
40 /* DEBUG: Store the last owner for bug hunting */
41 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U)
42 /* Panic if kmem_cache_create() fails */
43 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U)
44 /*
45 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
46 *
47 * This delays freeing the SLAB page by a grace period, it does _NOT_
48 * delay object freeing. This means that if you do kmem_cache_free()
49 * that memory location is free to be reused at any time. Thus it may
50 * be possible to see another object there in the same RCU grace period.
51 *
52 * This feature only ensures the memory location backing the object
53 * stays valid, the trick to using this is relying on an independent
54 * object validation pass. Something like:
55 *
56 * rcu_read_lock()
57 * again:
58 * obj = lockless_lookup(key);
59 * if (obj) {
60 * if (!try_get_ref(obj)) // might fail for free objects
61 * goto again;
62 *
63 * if (obj->key != key) { // not the object we expected
64 * put_ref(obj);
65 * goto again;
66 * }
67 * }
68 * rcu_read_unlock();
69 *
70 * This is useful if we need to approach a kernel structure obliquely,
71 * from its address obtained without the usual locking. We can lock
72 * the structure to stabilize it and check it's still at the given address,
73 * only if we can be sure that the memory has not been meanwhile reused
74 * for some other kind of object (which our subsystem's lock might corrupt).
75 *
76 * rcu_read_lock before reading the address, then rcu_read_unlock after
77 * taking the spinlock within the structure expected at that address.
78 *
79 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
80 */
81 /* Defer freeing slabs to RCU */
82 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U)
83 /* Spread some memory over cpuset */
84 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U)
85 /* Trace allocations and frees */
86 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U)
87
88 /* Flag to prevent checks on free */
89 #ifdef CONFIG_DEBUG_OBJECTS
90 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U)
91 #else
92 # define SLAB_DEBUG_OBJECTS 0
93 #endif
94
95 /* Avoid kmemleak tracing */
96 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U)
97
98 /* Fault injection mark */
99 #ifdef CONFIG_FAILSLAB
100 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U)
101 #else
102 # define SLAB_FAILSLAB 0
103 #endif
104 /* Account to memcg */
105 #ifdef CONFIG_MEMCG_KMEM
106 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U)
107 #else
108 # define SLAB_ACCOUNT 0
109 #endif
110
111 #ifdef CONFIG_KASAN_GENERIC
112 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U)
113 #else
114 #define SLAB_KASAN 0
115 #endif
116
117 /*
118 * Ignore user specified debugging flags.
119 * Intended for caches created for self-tests so they have only flags
120 * specified in the code and other flags are ignored.
121 */
122 #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U)
123
124 #ifdef CONFIG_KFENCE
125 #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U)
126 #else
127 #define SLAB_SKIP_KFENCE 0
128 #endif
129
130 /* The following flags affect the page allocator grouping pages by mobility */
131 /* Objects are reclaimable */
132 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U)
133 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
134
135 /*
136 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
137 *
138 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
139 *
140 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
141 * Both make kfree a no-op.
142 */
143 #define ZERO_SIZE_PTR ((void *)16)
144
145 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
146 (unsigned long)ZERO_SIZE_PTR)
147
148 #include <linux/kasan.h>
149
150 struct list_lru;
151 struct mem_cgroup;
152 /*
153 * struct kmem_cache related prototypes
154 */
155 void __init kmem_cache_init(void);
156 bool slab_is_available(void);
157
158 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
159 unsigned int align, slab_flags_t flags,
160 void (*ctor)(void *));
161 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
162 unsigned int size, unsigned int align,
163 slab_flags_t flags,
164 unsigned int useroffset, unsigned int usersize,
165 void (*ctor)(void *));
166 void kmem_cache_destroy(struct kmem_cache *s);
167 int kmem_cache_shrink(struct kmem_cache *s);
168
169 /*
170 * Please use this macro to create slab caches. Simply specify the
171 * name of the structure and maybe some flags that are listed above.
172 *
173 * The alignment of the struct determines object alignment. If you
174 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
175 * then the objects will be properly aligned in SMP configurations.
176 */
177 #define KMEM_CACHE(__struct, __flags) \
178 kmem_cache_create(#__struct, sizeof(struct __struct), \
179 __alignof__(struct __struct), (__flags), NULL)
180
181 /*
182 * To whitelist a single field for copying to/from usercopy, use this
183 * macro instead for KMEM_CACHE() above.
184 */
185 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
186 kmem_cache_create_usercopy(#__struct, \
187 sizeof(struct __struct), \
188 __alignof__(struct __struct), (__flags), \
189 offsetof(struct __struct, __field), \
190 sizeof_field(struct __struct, __field), NULL)
191
192 /*
193 * Common kmalloc functions provided by all allocators
194 */
195 void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2);
196 void kfree(const void *objp);
197 void kfree_sensitive(const void *objp);
198 size_t __ksize(const void *objp);
199
200 /**
201 * ksize - Report actual allocation size of associated object
202 *
203 * @objp: Pointer returned from a prior kmalloc()-family allocation.
204 *
205 * This should not be used for writing beyond the originally requested
206 * allocation size. Either use krealloc() or round up the allocation size
207 * with kmalloc_size_roundup() prior to allocation. If this is used to
208 * access beyond the originally requested allocation size, UBSAN_BOUNDS
209 * and/or FORTIFY_SOURCE may trip, since they only know about the
210 * originally allocated size via the __alloc_size attribute.
211 */
212 size_t ksize(const void *objp);
213
214 #ifdef CONFIG_PRINTK
215 bool kmem_valid_obj(void *object);
216 void kmem_dump_obj(void *object);
217 #endif
218
219 /*
220 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
221 * alignment larger than the alignment of a 64-bit integer.
222 * Setting ARCH_DMA_MINALIGN in arch headers allows that.
223 */
224 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
225 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
226 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
227 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
228 #else
229 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
230 #endif
231
232 /*
233 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
234 * Intended for arches that get misalignment faults even for 64 bit integer
235 * aligned buffers.
236 */
237 #ifndef ARCH_SLAB_MINALIGN
238 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
239 #endif
240
241 /*
242 * Arches can define this function if they want to decide the minimum slab
243 * alignment at runtime. The value returned by the function must be a power
244 * of two and >= ARCH_SLAB_MINALIGN.
245 */
246 #ifndef arch_slab_minalign
arch_slab_minalign(void)247 static inline unsigned int arch_slab_minalign(void)
248 {
249 return ARCH_SLAB_MINALIGN;
250 }
251 #endif
252
253 /*
254 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN.
255 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN
256 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment.
257 */
258 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
259 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
260 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
261
262 /*
263 * Kmalloc array related definitions
264 */
265
266 #ifdef CONFIG_SLAB
267 /*
268 * SLAB and SLUB directly allocates requests fitting in to an order-1 page
269 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
270 */
271 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
272 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
273 #ifndef KMALLOC_SHIFT_LOW
274 #define KMALLOC_SHIFT_LOW 5
275 #endif
276 #endif
277
278 #ifdef CONFIG_SLUB
279 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
280 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
281 #ifndef KMALLOC_SHIFT_LOW
282 #define KMALLOC_SHIFT_LOW 3
283 #endif
284 #endif
285
286 #ifdef CONFIG_SLOB
287 /*
288 * SLOB passes all requests larger than one page to the page allocator.
289 * No kmalloc array is necessary since objects of different sizes can
290 * be allocated from the same page.
291 */
292 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
293 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
294 #ifndef KMALLOC_SHIFT_LOW
295 #define KMALLOC_SHIFT_LOW 3
296 #endif
297 #endif
298
299 /* Maximum allocatable size */
300 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
301 /* Maximum size for which we actually use a slab cache */
302 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
303 /* Maximum order allocatable via the slab allocator */
304 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
305
306 /*
307 * Kmalloc subsystem.
308 */
309 #ifndef KMALLOC_MIN_SIZE
310 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
311 #endif
312
313 /*
314 * This restriction comes from byte sized index implementation.
315 * Page size is normally 2^12 bytes and, in this case, if we want to use
316 * byte sized index which can represent 2^8 entries, the size of the object
317 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
318 * If minimum size of kmalloc is less than 16, we use it as minimum object
319 * size and give up to use byte sized index.
320 */
321 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
322 (KMALLOC_MIN_SIZE) : 16)
323
324 /*
325 * Whenever changing this, take care of that kmalloc_type() and
326 * create_kmalloc_caches() still work as intended.
327 *
328 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP
329 * is for accounted but unreclaimable and non-dma objects. All the other
330 * kmem caches can have both accounted and unaccounted objects.
331 */
332 enum kmalloc_cache_type {
333 KMALLOC_NORMAL = 0,
334 #ifndef CONFIG_ZONE_DMA
335 KMALLOC_DMA = KMALLOC_NORMAL,
336 #endif
337 #ifndef CONFIG_MEMCG_KMEM
338 KMALLOC_CGROUP = KMALLOC_NORMAL,
339 #else
340 KMALLOC_CGROUP,
341 #endif
342 KMALLOC_RECLAIM,
343 #ifdef CONFIG_ZONE_DMA
344 KMALLOC_DMA,
345 #endif
346 NR_KMALLOC_TYPES
347 };
348
349 #ifndef CONFIG_SLOB
350 extern struct kmem_cache *
351 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
352
353 /*
354 * Define gfp bits that should not be set for KMALLOC_NORMAL.
355 */
356 #define KMALLOC_NOT_NORMAL_BITS \
357 (__GFP_RECLAIMABLE | \
358 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \
359 (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0))
360
kmalloc_type(gfp_t flags)361 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
362 {
363 /*
364 * The most common case is KMALLOC_NORMAL, so test for it
365 * with a single branch for all the relevant flags.
366 */
367 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0))
368 return KMALLOC_NORMAL;
369
370 /*
371 * At least one of the flags has to be set. Their priorities in
372 * decreasing order are:
373 * 1) __GFP_DMA
374 * 2) __GFP_RECLAIMABLE
375 * 3) __GFP_ACCOUNT
376 */
377 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
378 return KMALLOC_DMA;
379 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE))
380 return KMALLOC_RECLAIM;
381 else
382 return KMALLOC_CGROUP;
383 }
384
385 /*
386 * Figure out which kmalloc slab an allocation of a certain size
387 * belongs to.
388 * 0 = zero alloc
389 * 1 = 65 .. 96 bytes
390 * 2 = 129 .. 192 bytes
391 * n = 2^(n-1)+1 .. 2^n
392 *
393 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
394 * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
395 * Callers where !size_is_constant should only be test modules, where runtime
396 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab().
397 */
__kmalloc_index(size_t size,bool size_is_constant)398 static __always_inline unsigned int __kmalloc_index(size_t size,
399 bool size_is_constant)
400 {
401 if (!size)
402 return 0;
403
404 if (size <= KMALLOC_MIN_SIZE)
405 return KMALLOC_SHIFT_LOW;
406
407 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
408 return 1;
409 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
410 return 2;
411 if (size <= 8) return 3;
412 if (size <= 16) return 4;
413 if (size <= 32) return 5;
414 if (size <= 64) return 6;
415 if (size <= 128) return 7;
416 if (size <= 256) return 8;
417 if (size <= 512) return 9;
418 if (size <= 1024) return 10;
419 if (size <= 2 * 1024) return 11;
420 if (size <= 4 * 1024) return 12;
421 if (size <= 8 * 1024) return 13;
422 if (size <= 16 * 1024) return 14;
423 if (size <= 32 * 1024) return 15;
424 if (size <= 64 * 1024) return 16;
425 if (size <= 128 * 1024) return 17;
426 if (size <= 256 * 1024) return 18;
427 if (size <= 512 * 1024) return 19;
428 if (size <= 1024 * 1024) return 20;
429 if (size <= 2 * 1024 * 1024) return 21;
430
431 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
432 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
433 else
434 BUG();
435
436 /* Will never be reached. Needed because the compiler may complain */
437 return -1;
438 }
439 static_assert(PAGE_SHIFT <= 20);
440 #define kmalloc_index(s) __kmalloc_index(s, true)
441 #endif /* !CONFIG_SLOB */
442
443 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
444 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_slab_alignment __malloc;
445 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
446 gfp_t gfpflags) __assume_slab_alignment __malloc;
447 void kmem_cache_free(struct kmem_cache *s, void *objp);
448
449 /*
450 * Bulk allocation and freeing operations. These are accelerated in an
451 * allocator specific way to avoid taking locks repeatedly or building
452 * metadata structures unnecessarily.
453 *
454 * Note that interrupts must be enabled when calling these functions.
455 */
456 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
457 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p);
458
459 /*
460 * Caller must not use kfree_bulk() on memory not originally allocated
461 * by kmalloc(), because the SLOB allocator cannot handle this.
462 */
kfree_bulk(size_t size,void ** p)463 static __always_inline void kfree_bulk(size_t size, void **p)
464 {
465 kmem_cache_free_bulk(NULL, size, p);
466 }
467
468 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
469 __alloc_size(1);
470 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment
471 __malloc;
472
473 void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size)
474 __assume_kmalloc_alignment __alloc_size(3);
475
476 void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
477 int node, size_t size) __assume_kmalloc_alignment
478 __alloc_size(4);
479 void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment
480 __alloc_size(1);
481
482 void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment
483 __alloc_size(1);
484
485 /**
486 * kmalloc - allocate memory
487 * @size: how many bytes of memory are required.
488 * @flags: the type of memory to allocate.
489 *
490 * kmalloc is the normal method of allocating memory
491 * for objects smaller than page size in the kernel.
492 *
493 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN
494 * bytes. For @size of power of two bytes, the alignment is also guaranteed
495 * to be at least to the size.
496 *
497 * The @flags argument may be one of the GFP flags defined at
498 * include/linux/gfp.h and described at
499 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
500 *
501 * The recommended usage of the @flags is described at
502 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>`
503 *
504 * Below is a brief outline of the most useful GFP flags
505 *
506 * %GFP_KERNEL
507 * Allocate normal kernel ram. May sleep.
508 *
509 * %GFP_NOWAIT
510 * Allocation will not sleep.
511 *
512 * %GFP_ATOMIC
513 * Allocation will not sleep. May use emergency pools.
514 *
515 * %GFP_HIGHUSER
516 * Allocate memory from high memory on behalf of user.
517 *
518 * Also it is possible to set different flags by OR'ing
519 * in one or more of the following additional @flags:
520 *
521 * %__GFP_HIGH
522 * This allocation has high priority and may use emergency pools.
523 *
524 * %__GFP_NOFAIL
525 * Indicate that this allocation is in no way allowed to fail
526 * (think twice before using).
527 *
528 * %__GFP_NORETRY
529 * If memory is not immediately available,
530 * then give up at once.
531 *
532 * %__GFP_NOWARN
533 * If allocation fails, don't issue any warnings.
534 *
535 * %__GFP_RETRY_MAYFAIL
536 * Try really hard to succeed the allocation but fail
537 * eventually.
538 */
kmalloc(size_t size,gfp_t flags)539 static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
540 {
541 if (__builtin_constant_p(size)) {
542 #ifndef CONFIG_SLOB
543 unsigned int index;
544 #endif
545 if (size > KMALLOC_MAX_CACHE_SIZE)
546 return kmalloc_large(size, flags);
547 #ifndef CONFIG_SLOB
548 index = kmalloc_index(size);
549
550 if (!index)
551 return ZERO_SIZE_PTR;
552
553 return kmalloc_trace(
554 kmalloc_caches[kmalloc_type(flags)][index],
555 flags, size);
556 #endif
557 }
558 return __kmalloc(size, flags);
559 }
560
561 #ifndef CONFIG_SLOB
kmalloc_node(size_t size,gfp_t flags,int node)562 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
563 {
564 if (__builtin_constant_p(size)) {
565 unsigned int index;
566
567 if (size > KMALLOC_MAX_CACHE_SIZE)
568 return kmalloc_large_node(size, flags, node);
569
570 index = kmalloc_index(size);
571
572 if (!index)
573 return ZERO_SIZE_PTR;
574
575 return kmalloc_node_trace(
576 kmalloc_caches[kmalloc_type(flags)][index],
577 flags, node, size);
578 }
579 return __kmalloc_node(size, flags, node);
580 }
581 #else
kmalloc_node(size_t size,gfp_t flags,int node)582 static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
583 {
584 if (__builtin_constant_p(size) && size > KMALLOC_MAX_CACHE_SIZE)
585 return kmalloc_large_node(size, flags, node);
586
587 return __kmalloc_node(size, flags, node);
588 }
589 #endif
590
591 /**
592 * kmalloc_array - allocate memory for an array.
593 * @n: number of elements.
594 * @size: element size.
595 * @flags: the type of memory to allocate (see kmalloc).
596 */
kmalloc_array(size_t n,size_t size,gfp_t flags)597 static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags)
598 {
599 size_t bytes;
600
601 if (unlikely(check_mul_overflow(n, size, &bytes)))
602 return NULL;
603 if (__builtin_constant_p(n) && __builtin_constant_p(size))
604 return kmalloc(bytes, flags);
605 return __kmalloc(bytes, flags);
606 }
607
608 /**
609 * krealloc_array - reallocate memory for an array.
610 * @p: pointer to the memory chunk to reallocate
611 * @new_n: new number of elements to alloc
612 * @new_size: new size of a single member of the array
613 * @flags: the type of memory to allocate (see kmalloc)
614 */
krealloc_array(void * p,size_t new_n,size_t new_size,gfp_t flags)615 static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p,
616 size_t new_n,
617 size_t new_size,
618 gfp_t flags)
619 {
620 size_t bytes;
621
622 if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
623 return NULL;
624
625 return krealloc(p, bytes, flags);
626 }
627
628 /**
629 * kcalloc - allocate memory for an array. The memory is set to zero.
630 * @n: number of elements.
631 * @size: element size.
632 * @flags: the type of memory to allocate (see kmalloc).
633 */
kcalloc(size_t n,size_t size,gfp_t flags)634 static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags)
635 {
636 return kmalloc_array(n, size, flags | __GFP_ZERO);
637 }
638
639 void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node,
640 unsigned long caller) __alloc_size(1);
641 #define kmalloc_node_track_caller(size, flags, node) \
642 __kmalloc_node_track_caller(size, flags, node, \
643 _RET_IP_)
644
645 /*
646 * kmalloc_track_caller is a special version of kmalloc that records the
647 * calling function of the routine calling it for slab leak tracking instead
648 * of just the calling function (confusing, eh?).
649 * It's useful when the call to kmalloc comes from a widely-used standard
650 * allocator where we care about the real place the memory allocation
651 * request comes from.
652 */
653 #define kmalloc_track_caller(size, flags) \
654 __kmalloc_node_track_caller(size, flags, \
655 NUMA_NO_NODE, _RET_IP_)
656
kmalloc_array_node(size_t n,size_t size,gfp_t flags,int node)657 static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
658 int node)
659 {
660 size_t bytes;
661
662 if (unlikely(check_mul_overflow(n, size, &bytes)))
663 return NULL;
664 if (__builtin_constant_p(n) && __builtin_constant_p(size))
665 return kmalloc_node(bytes, flags, node);
666 return __kmalloc_node(bytes, flags, node);
667 }
668
kcalloc_node(size_t n,size_t size,gfp_t flags,int node)669 static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
670 {
671 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
672 }
673
674 /*
675 * Shortcuts
676 */
kmem_cache_zalloc(struct kmem_cache * k,gfp_t flags)677 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
678 {
679 return kmem_cache_alloc(k, flags | __GFP_ZERO);
680 }
681
682 /**
683 * kzalloc - allocate memory. The memory is set to zero.
684 * @size: how many bytes of memory are required.
685 * @flags: the type of memory to allocate (see kmalloc).
686 */
kzalloc(size_t size,gfp_t flags)687 static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags)
688 {
689 return kmalloc(size, flags | __GFP_ZERO);
690 }
691
692 /**
693 * kzalloc_node - allocate zeroed memory from a particular memory node.
694 * @size: how many bytes of memory are required.
695 * @flags: the type of memory to allocate (see kmalloc).
696 * @node: memory node from which to allocate
697 */
kzalloc_node(size_t size,gfp_t flags,int node)698 static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node)
699 {
700 return kmalloc_node(size, flags | __GFP_ZERO, node);
701 }
702
703 extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
kvmalloc(size_t size,gfp_t flags)704 static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
705 {
706 return kvmalloc_node(size, flags, NUMA_NO_NODE);
707 }
kvzalloc_node(size_t size,gfp_t flags,int node)708 static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
709 {
710 return kvmalloc_node(size, flags | __GFP_ZERO, node);
711 }
kvzalloc(size_t size,gfp_t flags)712 static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
713 {
714 return kvmalloc(size, flags | __GFP_ZERO);
715 }
716
kvmalloc_array(size_t n,size_t size,gfp_t flags)717 static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
718 {
719 size_t bytes;
720
721 if (unlikely(check_mul_overflow(n, size, &bytes)))
722 return NULL;
723
724 return kvmalloc(bytes, flags);
725 }
726
kvcalloc(size_t n,size_t size,gfp_t flags)727 static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
728 {
729 return kvmalloc_array(n, size, flags | __GFP_ZERO);
730 }
731
732 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
733 __realloc_size(3);
734 extern void kvfree(const void *addr);
735 extern void kvfree_sensitive(const void *addr, size_t len);
736
737 unsigned int kmem_cache_size(struct kmem_cache *s);
738
739 /**
740 * kmalloc_size_roundup - Report allocation bucket size for the given size
741 *
742 * @size: Number of bytes to round up from.
743 *
744 * This returns the number of bytes that would be available in a kmalloc()
745 * allocation of @size bytes. For example, a 126 byte request would be
746 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly
747 * for the general-purpose kmalloc()-based allocations, and is not for the
748 * pre-sized kmem_cache_alloc()-based allocations.)
749 *
750 * Use this to kmalloc() the full bucket size ahead of time instead of using
751 * ksize() to query the size after an allocation.
752 */
753 size_t kmalloc_size_roundup(size_t size);
754
755 void __init kmem_cache_init_late(void);
756
757 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
758 int slab_prepare_cpu(unsigned int cpu);
759 int slab_dead_cpu(unsigned int cpu);
760 #else
761 #define slab_prepare_cpu NULL
762 #define slab_dead_cpu NULL
763 #endif
764
765 #endif /* _LINUX_SLAB_H */
766