Line data Source code
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 it is not possible to acquire a lock within a structure
80 : * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference
81 : * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages
82 : * are not zeroed before being given to the slab, which means that any
83 : * locks must be initialized after each and every kmem_struct_alloc().
84 : * Alternatively, make the ctor passed to kmem_cache_create() initialize
85 : * the locks at page-allocation time, as is done in __i915_request_ctor(),
86 : * sighand_ctor(), and anon_vma_ctor(). Such a ctor permits readers
87 : * to safely acquire those ctor-initialized locks under rcu_read_lock()
88 : * protection.
89 : *
90 : * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
91 : */
92 : /* Defer freeing slabs to RCU */
93 : #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U)
94 : /* Spread some memory over cpuset */
95 : #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U)
96 : /* Trace allocations and frees */
97 : #define SLAB_TRACE ((slab_flags_t __force)0x00200000U)
98 :
99 : /* Flag to prevent checks on free */
100 : #ifdef CONFIG_DEBUG_OBJECTS
101 : # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U)
102 : #else
103 : # define SLAB_DEBUG_OBJECTS 0
104 : #endif
105 :
106 : /* Avoid kmemleak tracing */
107 : #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U)
108 :
109 : /* Fault injection mark */
110 : #ifdef CONFIG_FAILSLAB
111 : # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U)
112 : #else
113 : # define SLAB_FAILSLAB 0
114 : #endif
115 : /* Account to memcg */
116 : #ifdef CONFIG_MEMCG_KMEM
117 : # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U)
118 : #else
119 : # define SLAB_ACCOUNT 0
120 : #endif
121 :
122 : #ifdef CONFIG_KASAN_GENERIC
123 : #define SLAB_KASAN ((slab_flags_t __force)0x08000000U)
124 : #else
125 : #define SLAB_KASAN 0
126 : #endif
127 :
128 : /*
129 : * Ignore user specified debugging flags.
130 : * Intended for caches created for self-tests so they have only flags
131 : * specified in the code and other flags are ignored.
132 : */
133 : #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U)
134 :
135 : #ifdef CONFIG_KFENCE
136 : #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U)
137 : #else
138 : #define SLAB_SKIP_KFENCE 0
139 : #endif
140 :
141 : /* The following flags affect the page allocator grouping pages by mobility */
142 : /* Objects are reclaimable */
143 : #ifndef CONFIG_SLUB_TINY
144 : #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U)
145 : #else
146 : #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0)
147 : #endif
148 : #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
149 :
150 : /*
151 : * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
152 : *
153 : * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
154 : *
155 : * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
156 : * Both make kfree a no-op.
157 : */
158 : #define ZERO_SIZE_PTR ((void *)16)
159 :
160 : #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
161 : (unsigned long)ZERO_SIZE_PTR)
162 :
163 : #include <linux/kasan.h>
164 :
165 : struct list_lru;
166 : struct mem_cgroup;
167 : /*
168 : * struct kmem_cache related prototypes
169 : */
170 : bool slab_is_available(void);
171 :
172 : struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
173 : unsigned int align, slab_flags_t flags,
174 : void (*ctor)(void *));
175 : struct kmem_cache *kmem_cache_create_usercopy(const char *name,
176 : unsigned int size, unsigned int align,
177 : slab_flags_t flags,
178 : unsigned int useroffset, unsigned int usersize,
179 : void (*ctor)(void *));
180 : void kmem_cache_destroy(struct kmem_cache *s);
181 : int kmem_cache_shrink(struct kmem_cache *s);
182 :
183 : /*
184 : * Please use this macro to create slab caches. Simply specify the
185 : * name of the structure and maybe some flags that are listed above.
186 : *
187 : * The alignment of the struct determines object alignment. If you
188 : * f.e. add ____cacheline_aligned_in_smp to the struct declaration
189 : * then the objects will be properly aligned in SMP configurations.
190 : */
191 : #define KMEM_CACHE(__struct, __flags) \
192 : kmem_cache_create(#__struct, sizeof(struct __struct), \
193 : __alignof__(struct __struct), (__flags), NULL)
194 :
195 : /*
196 : * To whitelist a single field for copying to/from usercopy, use this
197 : * macro instead for KMEM_CACHE() above.
198 : */
199 : #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
200 : kmem_cache_create_usercopy(#__struct, \
201 : sizeof(struct __struct), \
202 : __alignof__(struct __struct), (__flags), \
203 : offsetof(struct __struct, __field), \
204 : sizeof_field(struct __struct, __field), NULL)
205 :
206 : /*
207 : * Common kmalloc functions provided by all allocators
208 : */
209 : void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2);
210 : void kfree(const void *objp);
211 : void kfree_sensitive(const void *objp);
212 : size_t __ksize(const void *objp);
213 :
214 : /**
215 : * ksize - Report actual allocation size of associated object
216 : *
217 : * @objp: Pointer returned from a prior kmalloc()-family allocation.
218 : *
219 : * This should not be used for writing beyond the originally requested
220 : * allocation size. Either use krealloc() or round up the allocation size
221 : * with kmalloc_size_roundup() prior to allocation. If this is used to
222 : * access beyond the originally requested allocation size, UBSAN_BOUNDS
223 : * and/or FORTIFY_SOURCE may trip, since they only know about the
224 : * originally allocated size via the __alloc_size attribute.
225 : */
226 : size_t ksize(const void *objp);
227 :
228 : #ifdef CONFIG_PRINTK
229 : bool kmem_valid_obj(void *object);
230 : void kmem_dump_obj(void *object);
231 : #endif
232 :
233 : /*
234 : * Some archs want to perform DMA into kmalloc caches and need a guaranteed
235 : * alignment larger than the alignment of a 64-bit integer.
236 : * Setting ARCH_DMA_MINALIGN in arch headers allows that.
237 : */
238 : #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
239 : #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
240 : #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
241 : #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
242 : #else
243 : #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
244 : #endif
245 :
246 : /*
247 : * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
248 : * Intended for arches that get misalignment faults even for 64 bit integer
249 : * aligned buffers.
250 : */
251 : #ifndef ARCH_SLAB_MINALIGN
252 : #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
253 : #endif
254 :
255 : /*
256 : * Arches can define this function if they want to decide the minimum slab
257 : * alignment at runtime. The value returned by the function must be a power
258 : * of two and >= ARCH_SLAB_MINALIGN.
259 : */
260 : #ifndef arch_slab_minalign
261 : static inline unsigned int arch_slab_minalign(void)
262 : {
263 : return ARCH_SLAB_MINALIGN;
264 : }
265 : #endif
266 :
267 : /*
268 : * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN.
269 : * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN
270 : * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment.
271 : */
272 : #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
273 : #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
274 : #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
275 :
276 : /*
277 : * Kmalloc array related definitions
278 : */
279 :
280 : #ifdef CONFIG_SLAB
281 : /*
282 : * SLAB and SLUB directly allocates requests fitting in to an order-1 page
283 : * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
284 : */
285 : #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
286 : #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
287 : #ifndef KMALLOC_SHIFT_LOW
288 : #define KMALLOC_SHIFT_LOW 5
289 : #endif
290 : #endif
291 :
292 : #ifdef CONFIG_SLUB
293 : #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
294 : #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
295 : #ifndef KMALLOC_SHIFT_LOW
296 : #define KMALLOC_SHIFT_LOW 3
297 : #endif
298 : #endif
299 :
300 : /* Maximum allocatable size */
301 : #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
302 : /* Maximum size for which we actually use a slab cache */
303 : #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
304 : /* Maximum order allocatable via the slab allocator */
305 : #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
306 :
307 : /*
308 : * Kmalloc subsystem.
309 : */
310 : #ifndef KMALLOC_MIN_SIZE
311 : #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
312 : #endif
313 :
314 : /*
315 : * This restriction comes from byte sized index implementation.
316 : * Page size is normally 2^12 bytes and, in this case, if we want to use
317 : * byte sized index which can represent 2^8 entries, the size of the object
318 : * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
319 : * If minimum size of kmalloc is less than 16, we use it as minimum object
320 : * size and give up to use byte sized index.
321 : */
322 : #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
323 : (KMALLOC_MIN_SIZE) : 16)
324 :
325 : /*
326 : * Whenever changing this, take care of that kmalloc_type() and
327 : * create_kmalloc_caches() still work as intended.
328 : *
329 : * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP
330 : * is for accounted but unreclaimable and non-dma objects. All the other
331 : * kmem caches can have both accounted and unaccounted objects.
332 : */
333 : enum kmalloc_cache_type {
334 : KMALLOC_NORMAL = 0,
335 : #ifndef CONFIG_ZONE_DMA
336 : KMALLOC_DMA = KMALLOC_NORMAL,
337 : #endif
338 : #ifndef CONFIG_MEMCG_KMEM
339 : KMALLOC_CGROUP = KMALLOC_NORMAL,
340 : #endif
341 : #ifdef CONFIG_SLUB_TINY
342 : KMALLOC_RECLAIM = KMALLOC_NORMAL,
343 : #else
344 : KMALLOC_RECLAIM,
345 : #endif
346 : #ifdef CONFIG_ZONE_DMA
347 : KMALLOC_DMA,
348 : #endif
349 : #ifdef CONFIG_MEMCG_KMEM
350 : KMALLOC_CGROUP,
351 : #endif
352 : NR_KMALLOC_TYPES
353 : };
354 :
355 : extern struct kmem_cache *
356 : kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
357 :
358 : /*
359 : * Define gfp bits that should not be set for KMALLOC_NORMAL.
360 : */
361 : #define KMALLOC_NOT_NORMAL_BITS \
362 : (__GFP_RECLAIMABLE | \
363 : (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \
364 : (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0))
365 :
366 : static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
367 : {
368 : /*
369 : * The most common case is KMALLOC_NORMAL, so test for it
370 : * with a single branch for all the relevant flags.
371 : */
372 7406 : if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0))
373 : return KMALLOC_NORMAL;
374 :
375 : /*
376 : * At least one of the flags has to be set. Their priorities in
377 : * decreasing order are:
378 : * 1) __GFP_DMA
379 : * 2) __GFP_RECLAIMABLE
380 : * 3) __GFP_ACCOUNT
381 : */
382 : if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
383 : return KMALLOC_DMA;
384 : if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE))
385 : return KMALLOC_RECLAIM;
386 : else
387 : return KMALLOC_CGROUP;
388 : }
389 :
390 : /*
391 : * Figure out which kmalloc slab an allocation of a certain size
392 : * belongs to.
393 : * 0 = zero alloc
394 : * 1 = 65 .. 96 bytes
395 : * 2 = 129 .. 192 bytes
396 : * n = 2^(n-1)+1 .. 2^n
397 : *
398 : * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
399 : * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
400 : * Callers where !size_is_constant should only be test modules, where runtime
401 : * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab().
402 : */
403 : static __always_inline unsigned int __kmalloc_index(size_t size,
404 : bool size_is_constant)
405 : {
406 : if (!size)
407 : return 0;
408 :
409 2084 : if (size <= KMALLOC_MIN_SIZE)
410 : return KMALLOC_SHIFT_LOW;
411 :
412 2051 : if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
413 : return 1;
414 2051 : if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
415 : return 2;
416 : if (size <= 8) return 3;
417 2050 : if (size <= 16) return 4;
418 2049 : if (size <= 32) return 5;
419 1984 : if (size <= 64) return 6;
420 1361 : if (size <= 128) return 7;
421 1361 : if (size <= 256) return 8;
422 1361 : if (size <= 512) return 9;
423 1338 : if (size <= 1024) return 10;
424 783 : if (size <= 2 * 1024) return 11;
425 751 : if (size <= 4 * 1024) return 12;
426 : if (size <= 8 * 1024) return 13;
427 : if (size <= 16 * 1024) return 14;
428 : if (size <= 32 * 1024) return 15;
429 : if (size <= 64 * 1024) return 16;
430 : if (size <= 128 * 1024) return 17;
431 : if (size <= 256 * 1024) return 18;
432 : if (size <= 512 * 1024) return 19;
433 : if (size <= 1024 * 1024) return 20;
434 : if (size <= 2 * 1024 * 1024) return 21;
435 :
436 : if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
437 : BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
438 : else
439 : BUG();
440 :
441 : /* Will never be reached. Needed because the compiler may complain */
442 : return -1;
443 : }
444 : static_assert(PAGE_SHIFT <= 20);
445 : #define kmalloc_index(s) __kmalloc_index(s, true)
446 :
447 : void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
448 :
449 : /**
450 : * kmem_cache_alloc - Allocate an object
451 : * @cachep: The cache to allocate from.
452 : * @flags: See kmalloc().
453 : *
454 : * Allocate an object from this cache.
455 : * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags.
456 : *
457 : * Return: pointer to the new object or %NULL in case of error
458 : */
459 : void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) __assume_slab_alignment __malloc;
460 : void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
461 : gfp_t gfpflags) __assume_slab_alignment __malloc;
462 : void kmem_cache_free(struct kmem_cache *s, void *objp);
463 :
464 : /*
465 : * Bulk allocation and freeing operations. These are accelerated in an
466 : * allocator specific way to avoid taking locks repeatedly or building
467 : * metadata structures unnecessarily.
468 : *
469 : * Note that interrupts must be enabled when calling these functions.
470 : */
471 : void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
472 : int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p);
473 :
474 : static __always_inline void kfree_bulk(size_t size, void **p)
475 : {
476 : kmem_cache_free_bulk(NULL, size, p);
477 : }
478 :
479 : void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
480 : __alloc_size(1);
481 : void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment
482 : __malloc;
483 :
484 : void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size)
485 : __assume_kmalloc_alignment __alloc_size(3);
486 :
487 : void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags,
488 : int node, size_t size) __assume_kmalloc_alignment
489 : __alloc_size(4);
490 : void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment
491 : __alloc_size(1);
492 :
493 : void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment
494 : __alloc_size(1);
495 :
496 : /**
497 : * kmalloc - allocate kernel memory
498 : * @size: how many bytes of memory are required.
499 : * @flags: describe the allocation context
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_types.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 : * Also it is possible to set different flags by OR'ing
527 : * in one or more of the following additional @flags:
528 : *
529 : * %__GFP_ZERO
530 : * Zero the allocated memory before returning. Also see kzalloc().
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 : */
550 : static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
551 : {
552 2735 : if (__builtin_constant_p(size) && size) {
553 : unsigned int index;
554 :
555 1809 : if (size > KMALLOC_MAX_CACHE_SIZE)
556 0 : return kmalloc_large(size, flags);
557 :
558 41669 : index = kmalloc_index(size);
559 41669 : return kmalloc_trace(
560 41669 : kmalloc_caches[kmalloc_type(flags)][index],
561 : flags, size);
562 : }
563 926 : return __kmalloc(size, flags);
564 : }
565 :
566 : static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
567 : {
568 548 : if (__builtin_constant_p(size) && size) {
569 : unsigned int index;
570 :
571 275 : if (size > KMALLOC_MAX_CACHE_SIZE)
572 0 : return kmalloc_large_node(size, flags, node);
573 :
574 285 : index = kmalloc_index(size);
575 285 : return kmalloc_node_trace(
576 285 : kmalloc_caches[kmalloc_type(flags)][index],
577 : flags, node, size);
578 : }
579 273 : return __kmalloc_node(size, flags, node);
580 : }
581 :
582 : /**
583 : * kmalloc_array - allocate memory for an array.
584 : * @n: number of elements.
585 : * @size: element size.
586 : * @flags: the type of memory to allocate (see kmalloc).
587 : */
588 1143 : static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags)
589 : {
590 : size_t bytes;
591 :
592 2286 : if (unlikely(check_mul_overflow(n, size, &bytes)))
593 : return NULL;
594 1143 : if (__builtin_constant_p(n) && __builtin_constant_p(size))
595 66 : return kmalloc(bytes, flags);
596 1077 : return __kmalloc(bytes, flags);
597 : }
598 :
599 : /**
600 : * krealloc_array - reallocate memory for an array.
601 : * @p: pointer to the memory chunk to reallocate
602 : * @new_n: new number of elements to alloc
603 : * @new_size: new size of a single member of the array
604 : * @flags: the type of memory to allocate (see kmalloc)
605 : */
606 : static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p,
607 : size_t new_n,
608 : size_t new_size,
609 : gfp_t flags)
610 : {
611 : size_t bytes;
612 :
613 0 : if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
614 : return NULL;
615 :
616 0 : return krealloc(p, bytes, flags);
617 : }
618 :
619 : /**
620 : * kcalloc - allocate memory for an array. The memory is set to zero.
621 : * @n: number of elements.
622 : * @size: element size.
623 : * @flags: the type of memory to allocate (see kmalloc).
624 : */
625 : static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags)
626 : {
627 608 : return kmalloc_array(n, size, flags | __GFP_ZERO);
628 : }
629 :
630 : void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node,
631 : unsigned long caller) __alloc_size(1);
632 : #define kmalloc_node_track_caller(size, flags, node) \
633 : __kmalloc_node_track_caller(size, flags, node, \
634 : _RET_IP_)
635 :
636 : /*
637 : * kmalloc_track_caller is a special version of kmalloc that records the
638 : * calling function of the routine calling it for slab leak tracking instead
639 : * of just the calling function (confusing, eh?).
640 : * It's useful when the call to kmalloc comes from a widely-used standard
641 : * allocator where we care about the real place the memory allocation
642 : * request comes from.
643 : */
644 : #define kmalloc_track_caller(size, flags) \
645 : __kmalloc_node_track_caller(size, flags, \
646 : NUMA_NO_NODE, _RET_IP_)
647 :
648 4 : static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
649 : int node)
650 : {
651 : size_t bytes;
652 :
653 8 : if (unlikely(check_mul_overflow(n, size, &bytes)))
654 : return NULL;
655 4 : if (__builtin_constant_p(n) && __builtin_constant_p(size))
656 0 : return kmalloc_node(bytes, flags, node);
657 4 : return __kmalloc_node(bytes, flags, node);
658 : }
659 :
660 : static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
661 : {
662 0 : return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
663 : }
664 :
665 : /*
666 : * Shortcuts
667 : */
668 : static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
669 : {
670 11548 : return kmem_cache_alloc(k, flags | __GFP_ZERO);
671 : }
672 :
673 : /**
674 : * kzalloc - allocate memory. The memory is set to zero.
675 : * @size: how many bytes of memory are required.
676 : * @flags: the type of memory to allocate (see kmalloc).
677 : */
678 2606 : static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags)
679 : {
680 83982 : return kmalloc(size, flags | __GFP_ZERO);
681 : }
682 :
683 : /**
684 : * kzalloc_node - allocate zeroed memory from a particular memory node.
685 : * @size: how many bytes of memory are required.
686 : * @flags: the type of memory to allocate (see kmalloc).
687 : * @node: memory node from which to allocate
688 : */
689 275 : static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node)
690 : {
691 570 : return kmalloc_node(size, flags | __GFP_ZERO, node);
692 : }
693 :
694 : extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
695 : static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
696 : {
697 0 : return kvmalloc_node(size, flags, NUMA_NO_NODE);
698 : }
699 : static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
700 : {
701 0 : return kvmalloc_node(size, flags | __GFP_ZERO, node);
702 : }
703 : static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
704 : {
705 0 : return kvmalloc(size, flags | __GFP_ZERO);
706 : }
707 :
708 : static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
709 : {
710 : size_t bytes;
711 :
712 0 : if (unlikely(check_mul_overflow(n, size, &bytes)))
713 : return NULL;
714 :
715 0 : return kvmalloc(bytes, flags);
716 : }
717 :
718 : static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
719 : {
720 0 : return kvmalloc_array(n, size, flags | __GFP_ZERO);
721 : }
722 :
723 : extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
724 : __realloc_size(3);
725 : extern void kvfree(const void *addr);
726 : extern void kvfree_sensitive(const void *addr, size_t len);
727 :
728 : unsigned int kmem_cache_size(struct kmem_cache *s);
729 :
730 : /**
731 : * kmalloc_size_roundup - Report allocation bucket size for the given size
732 : *
733 : * @size: Number of bytes to round up from.
734 : *
735 : * This returns the number of bytes that would be available in a kmalloc()
736 : * allocation of @size bytes. For example, a 126 byte request would be
737 : * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly
738 : * for the general-purpose kmalloc()-based allocations, and is not for the
739 : * pre-sized kmem_cache_alloc()-based allocations.)
740 : *
741 : * Use this to kmalloc() the full bucket size ahead of time instead of using
742 : * ksize() to query the size after an allocation.
743 : */
744 : size_t kmalloc_size_roundup(size_t size);
745 :
746 : void __init kmem_cache_init_late(void);
747 :
748 : #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
749 : int slab_prepare_cpu(unsigned int cpu);
750 : int slab_dead_cpu(unsigned int cpu);
751 : #else
752 : #define slab_prepare_cpu NULL
753 : #define slab_dead_cpu NULL
754 : #endif
755 :
756 : #endif /* _LINUX_SLAB_H */
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