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/cache.h> |
16 | #include <linux/gfp.h> |
17 | #include <linux/overflow.h> |
18 | #include <linux/types.h> |
19 | #include <linux/workqueue.h> |
20 | #include <linux/percpu-refcount.h> |
21 | #include <linux/cleanup.h> |
22 | #include <linux/hash.h> |
23 | |
24 | |
25 | /* |
26 | * Flags to pass to kmem_cache_create(). |
27 | * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set. |
28 | */ |
29 | /* DEBUG: Perform (expensive) checks on alloc/free */ |
30 | #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U) |
31 | /* DEBUG: Red zone objs in a cache */ |
32 | #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U) |
33 | /* DEBUG: Poison objects */ |
34 | #define SLAB_POISON ((slab_flags_t __force)0x00000800U) |
35 | /* Indicate a kmalloc slab */ |
36 | #define SLAB_KMALLOC ((slab_flags_t __force)0x00001000U) |
37 | /* Align objs on cache lines */ |
38 | #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U) |
39 | /* Use GFP_DMA memory */ |
40 | #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U) |
41 | /* Use GFP_DMA32 memory */ |
42 | #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U) |
43 | /* DEBUG: Store the last owner for bug hunting */ |
44 | #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U) |
45 | /* Panic if kmem_cache_create() fails */ |
46 | #define SLAB_PANIC ((slab_flags_t __force)0x00040000U) |
47 | /* |
48 | * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS! |
49 | * |
50 | * This delays freeing the SLAB page by a grace period, it does _NOT_ |
51 | * delay object freeing. This means that if you do kmem_cache_free() |
52 | * that memory location is free to be reused at any time. Thus it may |
53 | * be possible to see another object there in the same RCU grace period. |
54 | * |
55 | * This feature only ensures the memory location backing the object |
56 | * stays valid, the trick to using this is relying on an independent |
57 | * object validation pass. Something like: |
58 | * |
59 | * begin: |
60 | * rcu_read_lock(); |
61 | * obj = lockless_lookup(key); |
62 | * if (obj) { |
63 | * if (!try_get_ref(obj)) // might fail for free objects |
64 | * rcu_read_unlock(); |
65 | * goto begin; |
66 | * |
67 | * if (obj->key != key) { // not the object we expected |
68 | * put_ref(obj); |
69 | * rcu_read_unlock(); |
70 | * goto begin; |
71 | * } |
72 | * } |
73 | * rcu_read_unlock(); |
74 | * |
75 | * This is useful if we need to approach a kernel structure obliquely, |
76 | * from its address obtained without the usual locking. We can lock |
77 | * the structure to stabilize it and check it's still at the given address, |
78 | * only if we can be sure that the memory has not been meanwhile reused |
79 | * for some other kind of object (which our subsystem's lock might corrupt). |
80 | * |
81 | * rcu_read_lock before reading the address, then rcu_read_unlock after |
82 | * taking the spinlock within the structure expected at that address. |
83 | * |
84 | * Note that it is not possible to acquire a lock within a structure |
85 | * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference |
86 | * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages |
87 | * are not zeroed before being given to the slab, which means that any |
88 | * locks must be initialized after each and every kmem_struct_alloc(). |
89 | * Alternatively, make the ctor passed to kmem_cache_create() initialize |
90 | * the locks at page-allocation time, as is done in __i915_request_ctor(), |
91 | * sighand_ctor(), and anon_vma_ctor(). Such a ctor permits readers |
92 | * to safely acquire those ctor-initialized locks under rcu_read_lock() |
93 | * protection. |
94 | * |
95 | * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. |
96 | */ |
97 | /* Defer freeing slabs to RCU */ |
98 | #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U) |
99 | /* Spread some memory over cpuset */ |
100 | #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U) |
101 | /* Trace allocations and frees */ |
102 | #define SLAB_TRACE ((slab_flags_t __force)0x00200000U) |
103 | |
104 | /* Flag to prevent checks on free */ |
105 | #ifdef CONFIG_DEBUG_OBJECTS |
106 | # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U) |
107 | #else |
108 | # define SLAB_DEBUG_OBJECTS 0 |
109 | #endif |
110 | |
111 | /* Avoid kmemleak tracing */ |
112 | #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U) |
113 | |
114 | /* |
115 | * Prevent merging with compatible kmem caches. This flag should be used |
116 | * cautiously. Valid use cases: |
117 | * |
118 | * - caches created for self-tests (e.g. kunit) |
119 | * - general caches created and used by a subsystem, only when a |
120 | * (subsystem-specific) debug option is enabled |
121 | * - performance critical caches, should be very rare and consulted with slab |
122 | * maintainers, and not used together with CONFIG_SLUB_TINY |
123 | */ |
124 | #define SLAB_NO_MERGE ((slab_flags_t __force)0x01000000U) |
125 | |
126 | /* Fault injection mark */ |
127 | #ifdef CONFIG_FAILSLAB |
128 | # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U) |
129 | #else |
130 | # define SLAB_FAILSLAB 0 |
131 | #endif |
132 | /* Account to memcg */ |
133 | #ifdef CONFIG_MEMCG_KMEM |
134 | # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U) |
135 | #else |
136 | # define SLAB_ACCOUNT 0 |
137 | #endif |
138 | |
139 | #ifdef CONFIG_KASAN_GENERIC |
140 | #define SLAB_KASAN ((slab_flags_t __force)0x08000000U) |
141 | #else |
142 | #define SLAB_KASAN 0 |
143 | #endif |
144 | |
145 | /* |
146 | * Ignore user specified debugging flags. |
147 | * Intended for caches created for self-tests so they have only flags |
148 | * specified in the code and other flags are ignored. |
149 | */ |
150 | #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U) |
151 | |
152 | #ifdef CONFIG_KFENCE |
153 | #define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U) |
154 | #else |
155 | #define SLAB_SKIP_KFENCE 0 |
156 | #endif |
157 | |
158 | /* The following flags affect the page allocator grouping pages by mobility */ |
159 | /* Objects are reclaimable */ |
160 | #ifndef CONFIG_SLUB_TINY |
161 | #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) |
162 | #else |
163 | #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0) |
164 | #endif |
165 | #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ |
166 | |
167 | /* |
168 | * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. |
169 | * |
170 | * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. |
171 | * |
172 | * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. |
173 | * Both make kfree a no-op. |
174 | */ |
175 | #define ZERO_SIZE_PTR ((void *)16) |
176 | |
177 | #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ |
178 | (unsigned long)ZERO_SIZE_PTR) |
179 | |
180 | #include <linux/kasan.h> |
181 | |
182 | struct list_lru; |
183 | struct mem_cgroup; |
184 | /* |
185 | * struct kmem_cache related prototypes |
186 | */ |
187 | bool slab_is_available(void); |
188 | |
189 | struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, |
190 | unsigned int align, slab_flags_t flags, |
191 | void (*ctor)(void *)); |
192 | struct kmem_cache *kmem_cache_create_usercopy(const char *name, |
193 | unsigned int size, unsigned int align, |
194 | slab_flags_t flags, |
195 | unsigned int useroffset, unsigned int usersize, |
196 | void (*ctor)(void *)); |
197 | void kmem_cache_destroy(struct kmem_cache *s); |
198 | int kmem_cache_shrink(struct kmem_cache *s); |
199 | |
200 | /* |
201 | * Please use this macro to create slab caches. Simply specify the |
202 | * name of the structure and maybe some flags that are listed above. |
203 | * |
204 | * The alignment of the struct determines object alignment. If you |
205 | * f.e. add ____cacheline_aligned_in_smp to the struct declaration |
206 | * then the objects will be properly aligned in SMP configurations. |
207 | */ |
208 | #define KMEM_CACHE(__struct, __flags) \ |
209 | kmem_cache_create(#__struct, sizeof(struct __struct), \ |
210 | __alignof__(struct __struct), (__flags), NULL) |
211 | |
212 | /* |
213 | * To whitelist a single field for copying to/from usercopy, use this |
214 | * macro instead for KMEM_CACHE() above. |
215 | */ |
216 | #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ |
217 | kmem_cache_create_usercopy(#__struct, \ |
218 | sizeof(struct __struct), \ |
219 | __alignof__(struct __struct), (__flags), \ |
220 | offsetof(struct __struct, __field), \ |
221 | sizeof_field(struct __struct, __field), NULL) |
222 | |
223 | /* |
224 | * Common kmalloc functions provided by all allocators |
225 | */ |
226 | void * __must_check krealloc(const void *objp, size_t new_size, gfp_t flags) __realloc_size(2); |
227 | void kfree(const void *objp); |
228 | void kfree_sensitive(const void *objp); |
229 | size_t __ksize(const void *objp); |
230 | |
231 | DEFINE_FREE(kfree, void *, if (_T) kfree(_T)) |
232 | |
233 | /** |
234 | * ksize - Report actual allocation size of associated object |
235 | * |
236 | * @objp: Pointer returned from a prior kmalloc()-family allocation. |
237 | * |
238 | * This should not be used for writing beyond the originally requested |
239 | * allocation size. Either use krealloc() or round up the allocation size |
240 | * with kmalloc_size_roundup() prior to allocation. If this is used to |
241 | * access beyond the originally requested allocation size, UBSAN_BOUNDS |
242 | * and/or FORTIFY_SOURCE may trip, since they only know about the |
243 | * originally allocated size via the __alloc_size attribute. |
244 | */ |
245 | size_t ksize(const void *objp); |
246 | |
247 | #ifdef CONFIG_PRINTK |
248 | bool kmem_dump_obj(void *object); |
249 | #else |
250 | static inline bool kmem_dump_obj(void *object) { return false; } |
251 | #endif |
252 | |
253 | /* |
254 | * Some archs want to perform DMA into kmalloc caches and need a guaranteed |
255 | * alignment larger than the alignment of a 64-bit integer. |
256 | * Setting ARCH_DMA_MINALIGN in arch headers allows that. |
257 | */ |
258 | #ifdef ARCH_HAS_DMA_MINALIGN |
259 | #if ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN) |
260 | #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN |
261 | #endif |
262 | #endif |
263 | |
264 | #ifndef ARCH_KMALLOC_MINALIGN |
265 | #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) |
266 | #elif ARCH_KMALLOC_MINALIGN > 8 |
267 | #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN |
268 | #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) |
269 | #endif |
270 | |
271 | /* |
272 | * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. |
273 | * Intended for arches that get misalignment faults even for 64 bit integer |
274 | * aligned buffers. |
275 | */ |
276 | #ifndef ARCH_SLAB_MINALIGN |
277 | #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) |
278 | #endif |
279 | |
280 | /* |
281 | * Arches can define this function if they want to decide the minimum slab |
282 | * alignment at runtime. The value returned by the function must be a power |
283 | * of two and >= ARCH_SLAB_MINALIGN. |
284 | */ |
285 | #ifndef arch_slab_minalign |
286 | static inline unsigned int arch_slab_minalign(void) |
287 | { |
288 | return ARCH_SLAB_MINALIGN; |
289 | } |
290 | #endif |
291 | |
292 | /* |
293 | * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN. |
294 | * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN |
295 | * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment. |
296 | */ |
297 | #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN) |
298 | #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN) |
299 | #define __assume_page_alignment __assume_aligned(PAGE_SIZE) |
300 | |
301 | /* |
302 | * Kmalloc array related definitions |
303 | */ |
304 | |
305 | #ifdef CONFIG_SLAB |
306 | /* |
307 | * SLAB and SLUB directly allocates requests fitting in to an order-1 page |
308 | * (PAGE_SIZE*2). Larger requests are passed to the page allocator. |
309 | */ |
310 | #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) |
311 | #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT) |
312 | #ifndef KMALLOC_SHIFT_LOW |
313 | #define KMALLOC_SHIFT_LOW 5 |
314 | #endif |
315 | #endif |
316 | |
317 | #ifdef CONFIG_SLUB |
318 | #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) |
319 | #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT) |
320 | #ifndef KMALLOC_SHIFT_LOW |
321 | #define KMALLOC_SHIFT_LOW 3 |
322 | #endif |
323 | #endif |
324 | |
325 | /* Maximum allocatable size */ |
326 | #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX) |
327 | /* Maximum size for which we actually use a slab cache */ |
328 | #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH) |
329 | /* Maximum order allocatable via the slab allocator */ |
330 | #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT) |
331 | |
332 | /* |
333 | * Kmalloc subsystem. |
334 | */ |
335 | #ifndef KMALLOC_MIN_SIZE |
336 | #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW) |
337 | #endif |
338 | |
339 | /* |
340 | * This restriction comes from byte sized index implementation. |
341 | * Page size is normally 2^12 bytes and, in this case, if we want to use |
342 | * byte sized index which can represent 2^8 entries, the size of the object |
343 | * should be equal or greater to 2^12 / 2^8 = 2^4 = 16. |
344 | * If minimum size of kmalloc is less than 16, we use it as minimum object |
345 | * size and give up to use byte sized index. |
346 | */ |
347 | #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ |
348 | (KMALLOC_MIN_SIZE) : 16) |
349 | |
350 | #ifdef CONFIG_RANDOM_KMALLOC_CACHES |
351 | #define RANDOM_KMALLOC_CACHES_NR 15 // # of cache copies |
352 | #else |
353 | #define RANDOM_KMALLOC_CACHES_NR 0 |
354 | #endif |
355 | |
356 | /* |
357 | * Whenever changing this, take care of that kmalloc_type() and |
358 | * create_kmalloc_caches() still work as intended. |
359 | * |
360 | * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP |
361 | * is for accounted but unreclaimable and non-dma objects. All the other |
362 | * kmem caches can have both accounted and unaccounted objects. |
363 | */ |
364 | enum kmalloc_cache_type { |
365 | KMALLOC_NORMAL = 0, |
366 | #ifndef CONFIG_ZONE_DMA |
367 | KMALLOC_DMA = KMALLOC_NORMAL, |
368 | #endif |
369 | #ifndef CONFIG_MEMCG_KMEM |
370 | KMALLOC_CGROUP = KMALLOC_NORMAL, |
371 | #endif |
372 | KMALLOC_RANDOM_START = KMALLOC_NORMAL, |
373 | KMALLOC_RANDOM_END = KMALLOC_RANDOM_START + RANDOM_KMALLOC_CACHES_NR, |
374 | #ifdef CONFIG_SLUB_TINY |
375 | KMALLOC_RECLAIM = KMALLOC_NORMAL, |
376 | #else |
377 | KMALLOC_RECLAIM, |
378 | #endif |
379 | #ifdef CONFIG_ZONE_DMA |
380 | KMALLOC_DMA, |
381 | #endif |
382 | #ifdef CONFIG_MEMCG_KMEM |
383 | KMALLOC_CGROUP, |
384 | #endif |
385 | NR_KMALLOC_TYPES |
386 | }; |
387 | |
388 | extern struct kmem_cache * |
389 | kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; |
390 | |
391 | /* |
392 | * Define gfp bits that should not be set for KMALLOC_NORMAL. |
393 | */ |
394 | #define KMALLOC_NOT_NORMAL_BITS \ |
395 | (__GFP_RECLAIMABLE | \ |
396 | (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ |
397 | (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) |
398 | |
399 | extern unsigned long random_kmalloc_seed; |
400 | |
401 | static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags, unsigned long caller) |
402 | { |
403 | /* |
404 | * The most common case is KMALLOC_NORMAL, so test for it |
405 | * with a single branch for all the relevant flags. |
406 | */ |
407 | if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) |
408 | #ifdef CONFIG_RANDOM_KMALLOC_CACHES |
409 | /* RANDOM_KMALLOC_CACHES_NR (=15) copies + the KMALLOC_NORMAL */ |
410 | return KMALLOC_RANDOM_START + hash_64(caller ^ random_kmalloc_seed, |
411 | ilog2(RANDOM_KMALLOC_CACHES_NR + 1)); |
412 | #else |
413 | return KMALLOC_NORMAL; |
414 | #endif |
415 | |
416 | /* |
417 | * At least one of the flags has to be set. Their priorities in |
418 | * decreasing order are: |
419 | * 1) __GFP_DMA |
420 | * 2) __GFP_RECLAIMABLE |
421 | * 3) __GFP_ACCOUNT |
422 | */ |
423 | if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) |
424 | return KMALLOC_DMA; |
425 | if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE)) |
426 | return KMALLOC_RECLAIM; |
427 | else |
428 | return KMALLOC_CGROUP; |
429 | } |
430 | |
431 | /* |
432 | * Figure out which kmalloc slab an allocation of a certain size |
433 | * belongs to. |
434 | * 0 = zero alloc |
435 | * 1 = 65 .. 96 bytes |
436 | * 2 = 129 .. 192 bytes |
437 | * n = 2^(n-1)+1 .. 2^n |
438 | * |
439 | * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; |
440 | * typical usage is via kmalloc_index() and therefore evaluated at compile-time. |
441 | * Callers where !size_is_constant should only be test modules, where runtime |
442 | * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). |
443 | */ |
444 | static __always_inline unsigned int __kmalloc_index(size_t size, |
445 | bool size_is_constant) |
446 | { |
447 | if (!size) |
448 | return 0; |
449 | |
450 | if (size <= KMALLOC_MIN_SIZE) |
451 | return KMALLOC_SHIFT_LOW; |
452 | |
453 | if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96) |
454 | return 1; |
455 | if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192) |
456 | return 2; |
457 | if (size <= 8) return 3; |
458 | if (size <= 16) return 4; |
459 | if (size <= 32) return 5; |
460 | if (size <= 64) return 6; |
461 | if (size <= 128) return 7; |
462 | if (size <= 256) return 8; |
463 | if (size <= 512) return 9; |
464 | if (size <= 1024) return 10; |
465 | if (size <= 2 * 1024) return 11; |
466 | if (size <= 4 * 1024) return 12; |
467 | if (size <= 8 * 1024) return 13; |
468 | if (size <= 16 * 1024) return 14; |
469 | if (size <= 32 * 1024) return 15; |
470 | if (size <= 64 * 1024) return 16; |
471 | if (size <= 128 * 1024) return 17; |
472 | if (size <= 256 * 1024) return 18; |
473 | if (size <= 512 * 1024) return 19; |
474 | if (size <= 1024 * 1024) return 20; |
475 | if (size <= 2 * 1024 * 1024) return 21; |
476 | |
477 | if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) |
478 | BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()" ); |
479 | else |
480 | BUG(); |
481 | |
482 | /* Will never be reached. Needed because the compiler may complain */ |
483 | return -1; |
484 | } |
485 | static_assert(PAGE_SHIFT <= 20); |
486 | #define kmalloc_index(s) __kmalloc_index(s, true) |
487 | |
488 | void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); |
489 | |
490 | /** |
491 | * kmem_cache_alloc - Allocate an object |
492 | * @cachep: The cache to allocate from. |
493 | * @flags: See kmalloc(). |
494 | * |
495 | * Allocate an object from this cache. |
496 | * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags. |
497 | * |
498 | * Return: pointer to the new object or %NULL in case of error |
499 | */ |
500 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) __assume_slab_alignment __malloc; |
501 | void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, |
502 | gfp_t gfpflags) __assume_slab_alignment __malloc; |
503 | void kmem_cache_free(struct kmem_cache *s, void *objp); |
504 | |
505 | /* |
506 | * Bulk allocation and freeing operations. These are accelerated in an |
507 | * allocator specific way to avoid taking locks repeatedly or building |
508 | * metadata structures unnecessarily. |
509 | * |
510 | * Note that interrupts must be enabled when calling these functions. |
511 | */ |
512 | void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p); |
513 | int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, void **p); |
514 | |
515 | static __always_inline void kfree_bulk(size_t size, void **p) |
516 | { |
517 | kmem_cache_free_bulk(NULL, size, p); |
518 | } |
519 | |
520 | void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment |
521 | __alloc_size(1); |
522 | void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node) __assume_slab_alignment |
523 | __malloc; |
524 | |
525 | void *kmalloc_trace(struct kmem_cache *s, gfp_t flags, size_t size) |
526 | __assume_kmalloc_alignment __alloc_size(3); |
527 | |
528 | void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, |
529 | int node, size_t size) __assume_kmalloc_alignment |
530 | __alloc_size(4); |
531 | void *kmalloc_large(size_t size, gfp_t flags) __assume_page_alignment |
532 | __alloc_size(1); |
533 | |
534 | void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_alignment |
535 | __alloc_size(1); |
536 | |
537 | /** |
538 | * kmalloc - allocate kernel memory |
539 | * @size: how many bytes of memory are required. |
540 | * @flags: describe the allocation context |
541 | * |
542 | * kmalloc is the normal method of allocating memory |
543 | * for objects smaller than page size in the kernel. |
544 | * |
545 | * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN |
546 | * bytes. For @size of power of two bytes, the alignment is also guaranteed |
547 | * to be at least to the size. |
548 | * |
549 | * The @flags argument may be one of the GFP flags defined at |
550 | * include/linux/gfp_types.h and described at |
551 | * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>` |
552 | * |
553 | * The recommended usage of the @flags is described at |
554 | * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>` |
555 | * |
556 | * Below is a brief outline of the most useful GFP flags |
557 | * |
558 | * %GFP_KERNEL |
559 | * Allocate normal kernel ram. May sleep. |
560 | * |
561 | * %GFP_NOWAIT |
562 | * Allocation will not sleep. |
563 | * |
564 | * %GFP_ATOMIC |
565 | * Allocation will not sleep. May use emergency pools. |
566 | * |
567 | * Also it is possible to set different flags by OR'ing |
568 | * in one or more of the following additional @flags: |
569 | * |
570 | * %__GFP_ZERO |
571 | * Zero the allocated memory before returning. Also see kzalloc(). |
572 | * |
573 | * %__GFP_HIGH |
574 | * This allocation has high priority and may use emergency pools. |
575 | * |
576 | * %__GFP_NOFAIL |
577 | * Indicate that this allocation is in no way allowed to fail |
578 | * (think twice before using). |
579 | * |
580 | * %__GFP_NORETRY |
581 | * If memory is not immediately available, |
582 | * then give up at once. |
583 | * |
584 | * %__GFP_NOWARN |
585 | * If allocation fails, don't issue any warnings. |
586 | * |
587 | * %__GFP_RETRY_MAYFAIL |
588 | * Try really hard to succeed the allocation but fail |
589 | * eventually. |
590 | */ |
591 | static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) |
592 | { |
593 | if (__builtin_constant_p(size) && size) { |
594 | unsigned int index; |
595 | |
596 | if (size > KMALLOC_MAX_CACHE_SIZE) |
597 | return kmalloc_large(size, flags); |
598 | |
599 | index = kmalloc_index(size); |
600 | return kmalloc_trace( |
601 | s: kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index], |
602 | flags, size); |
603 | } |
604 | return __kmalloc(size, flags); |
605 | } |
606 | |
607 | static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node) |
608 | { |
609 | if (__builtin_constant_p(size) && size) { |
610 | unsigned int index; |
611 | |
612 | if (size > KMALLOC_MAX_CACHE_SIZE) |
613 | return kmalloc_large_node(size, flags, node); |
614 | |
615 | index = kmalloc_index(size); |
616 | return kmalloc_node_trace( |
617 | s: kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index], |
618 | gfpflags: flags, node, size); |
619 | } |
620 | return __kmalloc_node(size, flags, node); |
621 | } |
622 | |
623 | /** |
624 | * kmalloc_array - allocate memory for an array. |
625 | * @n: number of elements. |
626 | * @size: element size. |
627 | * @flags: the type of memory to allocate (see kmalloc). |
628 | */ |
629 | static inline __alloc_size(1, 2) void *kmalloc_array(size_t n, size_t size, gfp_t flags) |
630 | { |
631 | size_t bytes; |
632 | |
633 | if (unlikely(check_mul_overflow(n, size, &bytes))) |
634 | return NULL; |
635 | if (__builtin_constant_p(n) && __builtin_constant_p(size)) |
636 | return kmalloc(size: bytes, flags); |
637 | return __kmalloc(size: bytes, flags); |
638 | } |
639 | |
640 | /** |
641 | * krealloc_array - reallocate memory for an array. |
642 | * @p: pointer to the memory chunk to reallocate |
643 | * @new_n: new number of elements to alloc |
644 | * @new_size: new size of a single member of the array |
645 | * @flags: the type of memory to allocate (see kmalloc) |
646 | */ |
647 | static inline __realloc_size(2, 3) void * __must_check krealloc_array(void *p, |
648 | size_t new_n, |
649 | size_t new_size, |
650 | gfp_t flags) |
651 | { |
652 | size_t bytes; |
653 | |
654 | if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) |
655 | return NULL; |
656 | |
657 | return krealloc(objp: p, new_size: bytes, flags); |
658 | } |
659 | |
660 | /** |
661 | * kcalloc - allocate memory for an array. The memory is set to zero. |
662 | * @n: number of elements. |
663 | * @size: element size. |
664 | * @flags: the type of memory to allocate (see kmalloc). |
665 | */ |
666 | static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags) |
667 | { |
668 | return kmalloc_array(n, size, flags: flags | __GFP_ZERO); |
669 | } |
670 | |
671 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, |
672 | unsigned long caller) __alloc_size(1); |
673 | #define kmalloc_node_track_caller(size, flags, node) \ |
674 | __kmalloc_node_track_caller(size, flags, node, \ |
675 | _RET_IP_) |
676 | |
677 | /* |
678 | * kmalloc_track_caller is a special version of kmalloc that records the |
679 | * calling function of the routine calling it for slab leak tracking instead |
680 | * of just the calling function (confusing, eh?). |
681 | * It's useful when the call to kmalloc comes from a widely-used standard |
682 | * allocator where we care about the real place the memory allocation |
683 | * request comes from. |
684 | */ |
685 | #define kmalloc_track_caller(size, flags) \ |
686 | __kmalloc_node_track_caller(size, flags, \ |
687 | NUMA_NO_NODE, _RET_IP_) |
688 | |
689 | static inline __alloc_size(1, 2) void *kmalloc_array_node(size_t n, size_t size, gfp_t flags, |
690 | int node) |
691 | { |
692 | size_t bytes; |
693 | |
694 | if (unlikely(check_mul_overflow(n, size, &bytes))) |
695 | return NULL; |
696 | if (__builtin_constant_p(n) && __builtin_constant_p(size)) |
697 | return kmalloc_node(size: bytes, flags, node); |
698 | return __kmalloc_node(size: bytes, flags, node); |
699 | } |
700 | |
701 | static inline __alloc_size(1, 2) void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node) |
702 | { |
703 | return kmalloc_array_node(n, size, flags: flags | __GFP_ZERO, node); |
704 | } |
705 | |
706 | /* |
707 | * Shortcuts |
708 | */ |
709 | static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) |
710 | { |
711 | return kmem_cache_alloc(cachep: k, flags: flags | __GFP_ZERO); |
712 | } |
713 | |
714 | /** |
715 | * kzalloc - allocate memory. The memory is set to zero. |
716 | * @size: how many bytes of memory are required. |
717 | * @flags: the type of memory to allocate (see kmalloc). |
718 | */ |
719 | static inline __alloc_size(1) void *kzalloc(size_t size, gfp_t flags) |
720 | { |
721 | return kmalloc(size, flags: flags | __GFP_ZERO); |
722 | } |
723 | |
724 | /** |
725 | * kzalloc_node - allocate zeroed memory from a particular memory node. |
726 | * @size: how many bytes of memory are required. |
727 | * @flags: the type of memory to allocate (see kmalloc). |
728 | * @node: memory node from which to allocate |
729 | */ |
730 | static inline __alloc_size(1) void *kzalloc_node(size_t size, gfp_t flags, int node) |
731 | { |
732 | return kmalloc_node(size, flags: flags | __GFP_ZERO, node); |
733 | } |
734 | |
735 | extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1); |
736 | static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags) |
737 | { |
738 | return kvmalloc_node(size, flags, NUMA_NO_NODE); |
739 | } |
740 | static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node) |
741 | { |
742 | return kvmalloc_node(size, flags: flags | __GFP_ZERO, node); |
743 | } |
744 | static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags) |
745 | { |
746 | return kvmalloc(size, flags: flags | __GFP_ZERO); |
747 | } |
748 | |
749 | static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags) |
750 | { |
751 | size_t bytes; |
752 | |
753 | if (unlikely(check_mul_overflow(n, size, &bytes))) |
754 | return NULL; |
755 | |
756 | return kvmalloc(size: bytes, flags); |
757 | } |
758 | |
759 | static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags) |
760 | { |
761 | return kvmalloc_array(n, size, flags: flags | __GFP_ZERO); |
762 | } |
763 | |
764 | extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) |
765 | __realloc_size(3); |
766 | extern void kvfree(const void *addr); |
767 | DEFINE_FREE(kvfree, void *, if (_T) kvfree(_T)) |
768 | |
769 | extern void kvfree_sensitive(const void *addr, size_t len); |
770 | |
771 | unsigned int kmem_cache_size(struct kmem_cache *s); |
772 | |
773 | /** |
774 | * kmalloc_size_roundup - Report allocation bucket size for the given size |
775 | * |
776 | * @size: Number of bytes to round up from. |
777 | * |
778 | * This returns the number of bytes that would be available in a kmalloc() |
779 | * allocation of @size bytes. For example, a 126 byte request would be |
780 | * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly |
781 | * for the general-purpose kmalloc()-based allocations, and is not for the |
782 | * pre-sized kmem_cache_alloc()-based allocations.) |
783 | * |
784 | * Use this to kmalloc() the full bucket size ahead of time instead of using |
785 | * ksize() to query the size after an allocation. |
786 | */ |
787 | size_t kmalloc_size_roundup(size_t size); |
788 | |
789 | void __init kmem_cache_init_late(void); |
790 | |
791 | #if defined(CONFIG_SMP) && defined(CONFIG_SLAB) |
792 | int slab_prepare_cpu(unsigned int cpu); |
793 | int slab_dead_cpu(unsigned int cpu); |
794 | #else |
795 | #define slab_prepare_cpu NULL |
796 | #define slab_dead_cpu NULL |
797 | #endif |
798 | |
799 | #endif /* _LINUX_SLAB_H */ |
800 | |