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 enum _slab_flag_bits {
25 _SLAB_CONSISTENCY_CHECKS,
26 _SLAB_RED_ZONE,
27 _SLAB_POISON,
28 _SLAB_KMALLOC,
29 _SLAB_HWCACHE_ALIGN,
30 _SLAB_CACHE_DMA,
31 _SLAB_CACHE_DMA32,
32 _SLAB_STORE_USER,
33 _SLAB_PANIC,
34 _SLAB_TYPESAFE_BY_RCU,
35 _SLAB_TRACE,
36 #ifdef CONFIG_DEBUG_OBJECTS
37 _SLAB_DEBUG_OBJECTS,
38 #endif
39 _SLAB_NOLEAKTRACE,
40 _SLAB_NO_MERGE,
41 #ifdef CONFIG_FAILSLAB
42 _SLAB_FAILSLAB,
43 #endif
44 #ifdef CONFIG_MEMCG
45 _SLAB_ACCOUNT,
46 #endif
47 #ifdef CONFIG_KASAN_GENERIC
48 _SLAB_KASAN,
49 #endif
50 _SLAB_NO_USER_FLAGS,
51 #ifdef CONFIG_KFENCE
52 _SLAB_SKIP_KFENCE,
53 #endif
54 #ifndef CONFIG_SLUB_TINY
55 _SLAB_RECLAIM_ACCOUNT,
56 #endif
57 _SLAB_OBJECT_POISON,
58 _SLAB_CMPXCHG_DOUBLE,
59 #ifdef CONFIG_SLAB_OBJ_EXT
60 _SLAB_NO_OBJ_EXT,
61 #endif
62 _SLAB_FLAGS_LAST_BIT
63 };
64
65 #define __SLAB_FLAG_BIT(nr) ((slab_flags_t __force)(1U << (nr)))
66 #define __SLAB_FLAG_UNUSED ((slab_flags_t __force)(0U))
67
68 /*
69 * Flags to pass to kmem_cache_create().
70 * The ones marked DEBUG need CONFIG_SLUB_DEBUG enabled, otherwise are no-op
71 */
72 /* DEBUG: Perform (expensive) checks on alloc/free */
73 #define SLAB_CONSISTENCY_CHECKS __SLAB_FLAG_BIT(_SLAB_CONSISTENCY_CHECKS)
74 /* DEBUG: Red zone objs in a cache */
75 #define SLAB_RED_ZONE __SLAB_FLAG_BIT(_SLAB_RED_ZONE)
76 /* DEBUG: Poison objects */
77 #define SLAB_POISON __SLAB_FLAG_BIT(_SLAB_POISON)
78 /* Indicate a kmalloc slab */
79 #define SLAB_KMALLOC __SLAB_FLAG_BIT(_SLAB_KMALLOC)
80 /* Align objs on cache lines */
81 #define SLAB_HWCACHE_ALIGN __SLAB_FLAG_BIT(_SLAB_HWCACHE_ALIGN)
82 /* Use GFP_DMA memory */
83 #define SLAB_CACHE_DMA __SLAB_FLAG_BIT(_SLAB_CACHE_DMA)
84 /* Use GFP_DMA32 memory */
85 #define SLAB_CACHE_DMA32 __SLAB_FLAG_BIT(_SLAB_CACHE_DMA32)
86 /* DEBUG: Store the last owner for bug hunting */
87 #define SLAB_STORE_USER __SLAB_FLAG_BIT(_SLAB_STORE_USER)
88 /* Panic if kmem_cache_create() fails */
89 #define SLAB_PANIC __SLAB_FLAG_BIT(_SLAB_PANIC)
90 /*
91 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
92 *
93 * This delays freeing the SLAB page by a grace period, it does _NOT_
94 * delay object freeing. This means that if you do kmem_cache_free()
95 * that memory location is free to be reused at any time. Thus it may
96 * be possible to see another object there in the same RCU grace period.
97 *
98 * This feature only ensures the memory location backing the object
99 * stays valid, the trick to using this is relying on an independent
100 * object validation pass. Something like:
101 *
102 * begin:
103 * rcu_read_lock();
104 * obj = lockless_lookup(key);
105 * if (obj) {
106 * if (!try_get_ref(obj)) // might fail for free objects
107 * rcu_read_unlock();
108 * goto begin;
109 *
110 * if (obj->key != key) { // not the object we expected
111 * put_ref(obj);
112 * rcu_read_unlock();
113 * goto begin;
114 * }
115 * }
116 * rcu_read_unlock();
117 *
118 * This is useful if we need to approach a kernel structure obliquely,
119 * from its address obtained without the usual locking. We can lock
120 * the structure to stabilize it and check it's still at the given address,
121 * only if we can be sure that the memory has not been meanwhile reused
122 * for some other kind of object (which our subsystem's lock might corrupt).
123 *
124 * rcu_read_lock before reading the address, then rcu_read_unlock after
125 * taking the spinlock within the structure expected at that address.
126 *
127 * Note that it is not possible to acquire a lock within a structure
128 * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference
129 * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages
130 * are not zeroed before being given to the slab, which means that any
131 * locks must be initialized after each and every kmem_struct_alloc().
132 * Alternatively, make the ctor passed to kmem_cache_create() initialize
133 * the locks at page-allocation time, as is done in __i915_request_ctor(),
134 * sighand_ctor(), and anon_vma_ctor(). Such a ctor permits readers
135 * to safely acquire those ctor-initialized locks under rcu_read_lock()
136 * protection.
137 *
138 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
139 */
140 /* Defer freeing slabs to RCU */
141 #define SLAB_TYPESAFE_BY_RCU __SLAB_FLAG_BIT(_SLAB_TYPESAFE_BY_RCU)
142 /* Trace allocations and frees */
143 #define SLAB_TRACE __SLAB_FLAG_BIT(_SLAB_TRACE)
144
145 /* Flag to prevent checks on free */
146 #ifdef CONFIG_DEBUG_OBJECTS
147 # define SLAB_DEBUG_OBJECTS __SLAB_FLAG_BIT(_SLAB_DEBUG_OBJECTS)
148 #else
149 # define SLAB_DEBUG_OBJECTS __SLAB_FLAG_UNUSED
150 #endif
151
152 /* Avoid kmemleak tracing */
153 #define SLAB_NOLEAKTRACE __SLAB_FLAG_BIT(_SLAB_NOLEAKTRACE)
154
155 /*
156 * Prevent merging with compatible kmem caches. This flag should be used
157 * cautiously. Valid use cases:
158 *
159 * - caches created for self-tests (e.g. kunit)
160 * - general caches created and used by a subsystem, only when a
161 * (subsystem-specific) debug option is enabled
162 * - performance critical caches, should be very rare and consulted with slab
163 * maintainers, and not used together with CONFIG_SLUB_TINY
164 */
165 #define SLAB_NO_MERGE __SLAB_FLAG_BIT(_SLAB_NO_MERGE)
166
167 /* Fault injection mark */
168 #ifdef CONFIG_FAILSLAB
169 # define SLAB_FAILSLAB __SLAB_FLAG_BIT(_SLAB_FAILSLAB)
170 #else
171 # define SLAB_FAILSLAB __SLAB_FLAG_UNUSED
172 #endif
173 /* Account to memcg */
174 #ifdef CONFIG_MEMCG
175 # define SLAB_ACCOUNT __SLAB_FLAG_BIT(_SLAB_ACCOUNT)
176 #else
177 # define SLAB_ACCOUNT __SLAB_FLAG_UNUSED
178 #endif
179
180 #ifdef CONFIG_KASAN_GENERIC
181 #define SLAB_KASAN __SLAB_FLAG_BIT(_SLAB_KASAN)
182 #else
183 #define SLAB_KASAN __SLAB_FLAG_UNUSED
184 #endif
185
186 /*
187 * Ignore user specified debugging flags.
188 * Intended for caches created for self-tests so they have only flags
189 * specified in the code and other flags are ignored.
190 */
191 #define SLAB_NO_USER_FLAGS __SLAB_FLAG_BIT(_SLAB_NO_USER_FLAGS)
192
193 #ifdef CONFIG_KFENCE
194 #define SLAB_SKIP_KFENCE __SLAB_FLAG_BIT(_SLAB_SKIP_KFENCE)
195 #else
196 #define SLAB_SKIP_KFENCE __SLAB_FLAG_UNUSED
197 #endif
198
199 /* The following flags affect the page allocator grouping pages by mobility */
200 /* Objects are reclaimable */
201 #ifndef CONFIG_SLUB_TINY
202 #define SLAB_RECLAIM_ACCOUNT __SLAB_FLAG_BIT(_SLAB_RECLAIM_ACCOUNT)
203 #else
204 #define SLAB_RECLAIM_ACCOUNT __SLAB_FLAG_UNUSED
205 #endif
206 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
207
208 /* Slab created using create_boot_cache */
209 #ifdef CONFIG_SLAB_OBJ_EXT
210 #define SLAB_NO_OBJ_EXT __SLAB_FLAG_BIT(_SLAB_NO_OBJ_EXT)
211 #else
212 #define SLAB_NO_OBJ_EXT __SLAB_FLAG_UNUSED
213 #endif
214
215 /*
216 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
217 *
218 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
219 *
220 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
221 * Both make kfree a no-op.
222 */
223 #define ZERO_SIZE_PTR ((void *)16)
224
225 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
226 (unsigned long)ZERO_SIZE_PTR)
227
228 #include <linux/kasan.h>
229
230 struct list_lru;
231 struct mem_cgroup;
232 /*
233 * struct kmem_cache related prototypes
234 */
235 bool slab_is_available(void);
236
237 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
238 unsigned int align, slab_flags_t flags,
239 void (*ctor)(void *));
240 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
241 unsigned int size, unsigned int align,
242 slab_flags_t flags,
243 unsigned int useroffset, unsigned int usersize,
244 void (*ctor)(void *));
245 void kmem_cache_destroy(struct kmem_cache *s);
246 int kmem_cache_shrink(struct kmem_cache *s);
247
248 /*
249 * Please use this macro to create slab caches. Simply specify the
250 * name of the structure and maybe some flags that are listed above.
251 *
252 * The alignment of the struct determines object alignment. If you
253 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
254 * then the objects will be properly aligned in SMP configurations.
255 */
256 #define KMEM_CACHE(__struct, __flags) \
257 kmem_cache_create(#__struct, sizeof(struct __struct), \
258 __alignof__(struct __struct), (__flags), NULL)
259
260 /*
261 * To whitelist a single field for copying to/from usercopy, use this
262 * macro instead for KMEM_CACHE() above.
263 */
264 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
265 kmem_cache_create_usercopy(#__struct, \
266 sizeof(struct __struct), \
267 __alignof__(struct __struct), (__flags), \
268 offsetof(struct __struct, __field), \
269 sizeof_field(struct __struct, __field), NULL)
270
271 /*
272 * Common kmalloc functions provided by all allocators
273 */
274 void * __must_check krealloc_noprof(const void *objp, size_t new_size,
275 gfp_t flags) __realloc_size(2);
276 #define krealloc(...) alloc_hooks(krealloc_noprof(__VA_ARGS__))
277
278 void kfree(const void *objp);
279 void kfree_sensitive(const void *objp);
280 size_t __ksize(const void *objp);
281
282 DEFINE_FREE(kfree, void *, if (!IS_ERR_OR_NULL(_T)) kfree(_T))
283
284 /**
285 * ksize - Report actual allocation size of associated object
286 *
287 * @objp: Pointer returned from a prior kmalloc()-family allocation.
288 *
289 * This should not be used for writing beyond the originally requested
290 * allocation size. Either use krealloc() or round up the allocation size
291 * with kmalloc_size_roundup() prior to allocation. If this is used to
292 * access beyond the originally requested allocation size, UBSAN_BOUNDS
293 * and/or FORTIFY_SOURCE may trip, since they only know about the
294 * originally allocated size via the __alloc_size attribute.
295 */
296 size_t ksize(const void *objp);
297
298 #ifdef CONFIG_PRINTK
299 bool kmem_dump_obj(void *object);
300 #else
301 static inline bool kmem_dump_obj(void *object) { return false; }
302 #endif
303
304 /*
305 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
306 * alignment larger than the alignment of a 64-bit integer.
307 * Setting ARCH_DMA_MINALIGN in arch headers allows that.
308 */
309 #ifdef ARCH_HAS_DMA_MINALIGN
310 #if ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN)
311 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
312 #endif
313 #endif
314
315 #ifndef ARCH_KMALLOC_MINALIGN
316 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
317 #elif ARCH_KMALLOC_MINALIGN > 8
318 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
319 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
320 #endif
321
322 /*
323 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
324 * Intended for arches that get misalignment faults even for 64 bit integer
325 * aligned buffers.
326 */
327 #ifndef ARCH_SLAB_MINALIGN
328 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
329 #endif
330
331 /*
332 * Arches can define this function if they want to decide the minimum slab
333 * alignment at runtime. The value returned by the function must be a power
334 * of two and >= ARCH_SLAB_MINALIGN.
335 */
336 #ifndef arch_slab_minalign
337 static inline unsigned int arch_slab_minalign(void)
338 {
339 return ARCH_SLAB_MINALIGN;
340 }
341 #endif
342
343 /*
344 * kmem_cache_alloc and friends return pointers aligned to ARCH_SLAB_MINALIGN.
345 * kmalloc and friends return pointers aligned to both ARCH_KMALLOC_MINALIGN
346 * and ARCH_SLAB_MINALIGN, but here we only assume the former alignment.
347 */
348 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
349 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
350 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
351
352 /*
353 * Kmalloc array related definitions
354 */
355
356 /*
357 * SLUB directly allocates requests fitting in to an order-1 page
358 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
359 */
360 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
361 #define KMALLOC_SHIFT_MAX (MAX_PAGE_ORDER + PAGE_SHIFT)
362 #ifndef KMALLOC_SHIFT_LOW
363 #define KMALLOC_SHIFT_LOW 3
364 #endif
365
366 /* Maximum allocatable size */
367 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
368 /* Maximum size for which we actually use a slab cache */
369 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
370 /* Maximum order allocatable via the slab allocator */
371 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
372
373 /*
374 * Kmalloc subsystem.
375 */
376 #ifndef KMALLOC_MIN_SIZE
377 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
378 #endif
379
380 /*
381 * This restriction comes from byte sized index implementation.
382 * Page size is normally 2^12 bytes and, in this case, if we want to use
383 * byte sized index which can represent 2^8 entries, the size of the object
384 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
385 * If minimum size of kmalloc is less than 16, we use it as minimum object
386 * size and give up to use byte sized index.
387 */
388 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
389 (KMALLOC_MIN_SIZE) : 16)
390
391 #ifdef CONFIG_RANDOM_KMALLOC_CACHES
392 #define RANDOM_KMALLOC_CACHES_NR 15 // # of cache copies
393 #else
394 #define RANDOM_KMALLOC_CACHES_NR 0
395 #endif
396
397 /*
398 * Whenever changing this, take care of that kmalloc_type() and
399 * create_kmalloc_caches() still work as intended.
400 *
401 * KMALLOC_NORMAL can contain only unaccounted objects whereas KMALLOC_CGROUP
402 * is for accounted but unreclaimable and non-dma objects. All the other
403 * kmem caches can have both accounted and unaccounted objects.
404 */
405 enum kmalloc_cache_type {
406 KMALLOC_NORMAL = 0,
407 #ifndef CONFIG_ZONE_DMA
408 KMALLOC_DMA = KMALLOC_NORMAL,
409 #endif
410 #ifndef CONFIG_MEMCG
411 KMALLOC_CGROUP = KMALLOC_NORMAL,
412 #endif
413 KMALLOC_RANDOM_START = KMALLOC_NORMAL,
414 KMALLOC_RANDOM_END = KMALLOC_RANDOM_START + RANDOM_KMALLOC_CACHES_NR,
415 #ifdef CONFIG_SLUB_TINY
416 KMALLOC_RECLAIM = KMALLOC_NORMAL,
417 #else
418 KMALLOC_RECLAIM,
419 #endif
420 #ifdef CONFIG_ZONE_DMA
421 KMALLOC_DMA,
422 #endif
423 #ifdef CONFIG_MEMCG
424 KMALLOC_CGROUP,
425 #endif
426 NR_KMALLOC_TYPES
427 };
428
429 typedef struct kmem_cache * kmem_buckets[KMALLOC_SHIFT_HIGH + 1];
430
431 extern kmem_buckets kmalloc_caches[NR_KMALLOC_TYPES];
432
433 /*
434 * Define gfp bits that should not be set for KMALLOC_NORMAL.
435 */
436 #define KMALLOC_NOT_NORMAL_BITS \
437 (__GFP_RECLAIMABLE | \
438 (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \
439 (IS_ENABLED(CONFIG_MEMCG) ? __GFP_ACCOUNT : 0))
440
441 extern unsigned long random_kmalloc_seed;
442
443 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags, unsigned long caller)
444 {
445 /*
446 * The most common case is KMALLOC_NORMAL, so test for it
447 * with a single branch for all the relevant flags.
448 */
449 if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0))
450 #ifdef CONFIG_RANDOM_KMALLOC_CACHES
451 /* RANDOM_KMALLOC_CACHES_NR (=15) copies + the KMALLOC_NORMAL */
452 return KMALLOC_RANDOM_START + hash_64(caller ^ random_kmalloc_seed,
453 ilog2(RANDOM_KMALLOC_CACHES_NR + 1));
454 #else
455 return KMALLOC_NORMAL;
456 #endif
457
458 /*
459 * At least one of the flags has to be set. Their priorities in
460 * decreasing order are:
461 * 1) __GFP_DMA
462 * 2) __GFP_RECLAIMABLE
463 * 3) __GFP_ACCOUNT
464 */
465 if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
466 return KMALLOC_DMA;
467 if (!IS_ENABLED(CONFIG_MEMCG) || (flags & __GFP_RECLAIMABLE))
468 return KMALLOC_RECLAIM;
469 else
470 return KMALLOC_CGROUP;
471 }
472
473 /*
474 * Figure out which kmalloc slab an allocation of a certain size
475 * belongs to.
476 * 0 = zero alloc
477 * 1 = 65 .. 96 bytes
478 * 2 = 129 .. 192 bytes
479 * n = 2^(n-1)+1 .. 2^n
480 *
481 * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized;
482 * typical usage is via kmalloc_index() and therefore evaluated at compile-time.
483 * Callers where !size_is_constant should only be test modules, where runtime
484 * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab().
485 */
486 static __always_inline unsigned int __kmalloc_index(size_t size,
487 bool size_is_constant)
488 {
489 if (!size)
490 return 0;
491
492 if (size <= KMALLOC_MIN_SIZE)
493 return KMALLOC_SHIFT_LOW;
494
495 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
496 return 1;
497 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
498 return 2;
499 if (size <= 8) return 3;
500 if (size <= 16) return 4;
501 if (size <= 32) return 5;
502 if (size <= 64) return 6;
503 if (size <= 128) return 7;
504 if (size <= 256) return 8;
505 if (size <= 512) return 9;
506 if (size <= 1024) return 10;
507 if (size <= 2 * 1024) return 11;
508 if (size <= 4 * 1024) return 12;
509 if (size <= 8 * 1024) return 13;
510 if (size <= 16 * 1024) return 14;
511 if (size <= 32 * 1024) return 15;
512 if (size <= 64 * 1024) return 16;
513 if (size <= 128 * 1024) return 17;
514 if (size <= 256 * 1024) return 18;
515 if (size <= 512 * 1024) return 19;
516 if (size <= 1024 * 1024) return 20;
517 if (size <= 2 * 1024 * 1024) return 21;
518
519 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
520 BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
521 else
522 BUG();
523
524 /* Will never be reached. Needed because the compiler may complain */
525 return -1;
526 }
527 static_assert(PAGE_SHIFT <= 20);
528 #define kmalloc_index(s) __kmalloc_index(s, true)
529
530 #include <linux/alloc_tag.h>
531
532 /**
533 * kmem_cache_alloc - Allocate an object
534 * @cachep: The cache to allocate from.
535 * @flags: See kmalloc().
536 *
537 * Allocate an object from this cache.
538 * See kmem_cache_zalloc() for a shortcut of adding __GFP_ZERO to flags.
539 *
540 * Return: pointer to the new object or %NULL in case of error
541 */
542 void *kmem_cache_alloc_noprof(struct kmem_cache *cachep,
543 gfp_t flags) __assume_slab_alignment __malloc;
544 #define kmem_cache_alloc(...) alloc_hooks(kmem_cache_alloc_noprof(__VA_ARGS__))
545
546 void *kmem_cache_alloc_lru_noprof(struct kmem_cache *s, struct list_lru *lru,
547 gfp_t gfpflags) __assume_slab_alignment __malloc;
548 #define kmem_cache_alloc_lru(...) alloc_hooks(kmem_cache_alloc_lru_noprof(__VA_ARGS__))
549
550 void kmem_cache_free(struct kmem_cache *s, void *objp);
551
552 kmem_buckets *kmem_buckets_create(const char *name, slab_flags_t flags,
553 unsigned int useroffset, unsigned int usersize,
554 void (*ctor)(void *));
555
556 /*
557 * Bulk allocation and freeing operations. These are accelerated in an
558 * allocator specific way to avoid taking locks repeatedly or building
559 * metadata structures unnecessarily.
560 *
561 * Note that interrupts must be enabled when calling these functions.
562 */
563 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
564
565 int kmem_cache_alloc_bulk_noprof(struct kmem_cache *s, gfp_t flags, size_t size, void **p);
566 #define kmem_cache_alloc_bulk(...) alloc_hooks(kmem_cache_alloc_bulk_noprof(__VA_ARGS__))
567
568 static __always_inline void kfree_bulk(size_t size, void **p)
569 {
570 kmem_cache_free_bulk(NULL, size, p);
571 }
572
573 void *kmem_cache_alloc_node_noprof(struct kmem_cache *s, gfp_t flags,
574 int node) __assume_slab_alignment __malloc;
575 #define kmem_cache_alloc_node(...) alloc_hooks(kmem_cache_alloc_node_noprof(__VA_ARGS__))
576
577 /*
578 * These macros allow declaring a kmem_buckets * parameter alongside size, which
579 * can be compiled out with CONFIG_SLAB_BUCKETS=n so that a large number of call
580 * sites don't have to pass NULL.
581 */
582 #ifdef CONFIG_SLAB_BUCKETS
583 #define DECL_BUCKET_PARAMS(_size, _b) size_t (_size), kmem_buckets *(_b)
584 #define PASS_BUCKET_PARAMS(_size, _b) (_size), (_b)
585 #define PASS_BUCKET_PARAM(_b) (_b)
586 #else
587 #define DECL_BUCKET_PARAMS(_size, _b) size_t (_size)
588 #define PASS_BUCKET_PARAMS(_size, _b) (_size)
589 #define PASS_BUCKET_PARAM(_b) NULL
590 #endif
591
592 /*
593 * The following functions are not to be used directly and are intended only
594 * for internal use from kmalloc() and kmalloc_node()
595 * with the exception of kunit tests
596 */
597
598 void *__kmalloc_noprof(size_t size, gfp_t flags)
599 __assume_kmalloc_alignment __alloc_size(1);
600
601 void *__kmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node)
602 __assume_kmalloc_alignment __alloc_size(1);
603
604 void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
605 __assume_kmalloc_alignment __alloc_size(3);
606
607 void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
608 int node, size_t size)
609 __assume_kmalloc_alignment __alloc_size(4);
610
611 void *__kmalloc_large_noprof(size_t size, gfp_t flags)
612 __assume_page_alignment __alloc_size(1);
613
614 void *__kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
615 __assume_page_alignment __alloc_size(1);
616
617 /**
618 * kmalloc - allocate kernel memory
619 * @size: how many bytes of memory are required.
620 * @flags: describe the allocation context
621 *
622 * kmalloc is the normal method of allocating memory
623 * for objects smaller than page size in the kernel.
624 *
625 * The allocated object address is aligned to at least ARCH_KMALLOC_MINALIGN
626 * bytes. For @size of power of two bytes, the alignment is also guaranteed
627 * to be at least to the size. For other sizes, the alignment is guaranteed to
628 * be at least the largest power-of-two divisor of @size.
629 *
630 * The @flags argument may be one of the GFP flags defined at
631 * include/linux/gfp_types.h and described at
632 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
633 *
634 * The recommended usage of the @flags is described at
635 * :ref:`Documentation/core-api/memory-allocation.rst <memory_allocation>`
636 *
637 * Below is a brief outline of the most useful GFP flags
638 *
639 * %GFP_KERNEL
640 * Allocate normal kernel ram. May sleep.
641 *
642 * %GFP_NOWAIT
643 * Allocation will not sleep.
644 *
645 * %GFP_ATOMIC
646 * Allocation will not sleep. May use emergency pools.
647 *
648 * Also it is possible to set different flags by OR'ing
649 * in one or more of the following additional @flags:
650 *
651 * %__GFP_ZERO
652 * Zero the allocated memory before returning. Also see kzalloc().
653 *
654 * %__GFP_HIGH
655 * This allocation has high priority and may use emergency pools.
656 *
657 * %__GFP_NOFAIL
658 * Indicate that this allocation is in no way allowed to fail
659 * (think twice before using).
660 *
661 * %__GFP_NORETRY
662 * If memory is not immediately available,
663 * then give up at once.
664 *
665 * %__GFP_NOWARN
666 * If allocation fails, don't issue any warnings.
667 *
668 * %__GFP_RETRY_MAYFAIL
669 * Try really hard to succeed the allocation but fail
670 * eventually.
671 */
672 static __always_inline __alloc_size(1) void *kmalloc_noprof(size_t size, gfp_t flags)
673 {
674 if (__builtin_constant_p(size) && size) {
675 unsigned int index;
676
677 if (size > KMALLOC_MAX_CACHE_SIZE)
678 return __kmalloc_large_noprof(size, flags);
679
680 index = kmalloc_index(size);
681 return __kmalloc_cache_noprof(
682 kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index],
683 flags, size);
684 }
685 return __kmalloc_noprof(size, flags);
686 }
687 #define kmalloc(...) alloc_hooks(kmalloc_noprof(__VA_ARGS__))
688
689 #define kmem_buckets_alloc(_b, _size, _flags) \
690 alloc_hooks(__kmalloc_node_noprof(PASS_BUCKET_PARAMS(_size, _b), _flags, NUMA_NO_NODE))
691
692 #define kmem_buckets_alloc_track_caller(_b, _size, _flags) \
693 alloc_hooks(__kmalloc_node_track_caller_noprof(PASS_BUCKET_PARAMS(_size, _b), _flags, NUMA_NO_NODE, _RET_IP_))
694
695 static __always_inline __alloc_size(1) void *kmalloc_node_noprof(size_t size, gfp_t flags, int node)
696 {
697 if (__builtin_constant_p(size) && size) {
698 unsigned int index;
699
700 if (size > KMALLOC_MAX_CACHE_SIZE)
701 return __kmalloc_large_node_noprof(size, flags, node);
702
703 index = kmalloc_index(size);
704 return __kmalloc_cache_node_noprof(
705 kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index],
706 flags, node, size);
707 }
708 return __kmalloc_node_noprof(PASS_BUCKET_PARAMS(size, NULL), flags, node);
709 }
710 #define kmalloc_node(...) alloc_hooks(kmalloc_node_noprof(__VA_ARGS__))
711
712 /**
713 * kmalloc_array - allocate memory for an array.
714 * @n: number of elements.
715 * @size: element size.
716 * @flags: the type of memory to allocate (see kmalloc).
717 */
718 static inline __alloc_size(1, 2) void *kmalloc_array_noprof(size_t n, size_t size, gfp_t flags)
719 {
720 size_t bytes;
721
722 if (unlikely(check_mul_overflow(n, size, &bytes)))
723 return NULL;
724 if (__builtin_constant_p(n) && __builtin_constant_p(size))
725 return kmalloc_noprof(bytes, flags);
726 return kmalloc_noprof(bytes, flags);
727 }
728 #define kmalloc_array(...) alloc_hooks(kmalloc_array_noprof(__VA_ARGS__))
729
730 /**
731 * krealloc_array - reallocate memory for an array.
732 * @p: pointer to the memory chunk to reallocate
733 * @new_n: new number of elements to alloc
734 * @new_size: new size of a single member of the array
735 * @flags: the type of memory to allocate (see kmalloc)
736 */
737 static inline __realloc_size(2, 3) void * __must_check krealloc_array_noprof(void *p,
738 size_t new_n,
739 size_t new_size,
740 gfp_t flags)
741 {
742 size_t bytes;
743
744 if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
745 return NULL;
746
747 return krealloc_noprof(p, bytes, flags);
748 }
749 #define krealloc_array(...) alloc_hooks(krealloc_array_noprof(__VA_ARGS__))
750
751 /**
752 * kcalloc - allocate memory for an array. The memory is set to zero.
753 * @n: number of elements.
754 * @size: element size.
755 * @flags: the type of memory to allocate (see kmalloc).
756 */
757 #define kcalloc(n, size, flags) kmalloc_array(n, size, (flags) | __GFP_ZERO)
758
759 void *__kmalloc_node_track_caller_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node,
760 unsigned long caller) __alloc_size(1);
761 #define kmalloc_node_track_caller_noprof(size, flags, node, caller) \
762 __kmalloc_node_track_caller_noprof(PASS_BUCKET_PARAMS(size, NULL), flags, node, caller)
763 #define kmalloc_node_track_caller(...) \
764 alloc_hooks(kmalloc_node_track_caller_noprof(__VA_ARGS__, _RET_IP_))
765
766 /*
767 * kmalloc_track_caller is a special version of kmalloc that records the
768 * calling function of the routine calling it for slab leak tracking instead
769 * of just the calling function (confusing, eh?).
770 * It's useful when the call to kmalloc comes from a widely-used standard
771 * allocator where we care about the real place the memory allocation
772 * request comes from.
773 */
774 #define kmalloc_track_caller(...) kmalloc_node_track_caller(__VA_ARGS__, NUMA_NO_NODE)
775
776 #define kmalloc_track_caller_noprof(...) \
777 kmalloc_node_track_caller_noprof(__VA_ARGS__, NUMA_NO_NODE, _RET_IP_)
778
779 static inline __alloc_size(1, 2) void *kmalloc_array_node_noprof(size_t n, size_t size, gfp_t flags,
780 int node)
781 {
782 size_t bytes;
783
784 if (unlikely(check_mul_overflow(n, size, &bytes)))
785 return NULL;
786 if (__builtin_constant_p(n) && __builtin_constant_p(size))
787 return kmalloc_node_noprof(bytes, flags, node);
788 return __kmalloc_node_noprof(PASS_BUCKET_PARAMS(bytes, NULL), flags, node);
789 }
790 #define kmalloc_array_node(...) alloc_hooks(kmalloc_array_node_noprof(__VA_ARGS__))
791
792 #define kcalloc_node(_n, _size, _flags, _node) \
793 kmalloc_array_node(_n, _size, (_flags) | __GFP_ZERO, _node)
794
795 /*
796 * Shortcuts
797 */
798 #define kmem_cache_zalloc(_k, _flags) kmem_cache_alloc(_k, (_flags)|__GFP_ZERO)
799
800 /**
801 * kzalloc - allocate memory. The memory is set to zero.
802 * @size: how many bytes of memory are required.
803 * @flags: the type of memory to allocate (see kmalloc).
804 */
805 static inline __alloc_size(1) void *kzalloc_noprof(size_t size, gfp_t flags)
806 {
807 return kmalloc_noprof(size, flags | __GFP_ZERO);
808 }
809 #define kzalloc(...) alloc_hooks(kzalloc_noprof(__VA_ARGS__))
810 #define kzalloc_node(_size, _flags, _node) kmalloc_node(_size, (_flags)|__GFP_ZERO, _node)
811
812 void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node) __alloc_size(1);
813 #define kvmalloc_node_noprof(size, flags, node) \
814 __kvmalloc_node_noprof(PASS_BUCKET_PARAMS(size, NULL), flags, node)
815 #define kvmalloc_node(...) alloc_hooks(kvmalloc_node_noprof(__VA_ARGS__))
816
817 #define kvmalloc(_size, _flags) kvmalloc_node(_size, _flags, NUMA_NO_NODE)
818 #define kvmalloc_noprof(_size, _flags) kvmalloc_node_noprof(_size, _flags, NUMA_NO_NODE)
819 #define kvzalloc(_size, _flags) kvmalloc(_size, (_flags)|__GFP_ZERO)
820
821 #define kvzalloc_node(_size, _flags, _node) kvmalloc_node(_size, (_flags)|__GFP_ZERO, _node)
822 #define kmem_buckets_valloc(_b, _size, _flags) \
823 alloc_hooks(__kvmalloc_node_noprof(PASS_BUCKET_PARAMS(_size, _b), _flags, NUMA_NO_NODE))
824
825 static inline __alloc_size(1, 2) void *
826 kvmalloc_array_node_noprof(size_t n, size_t size, gfp_t flags, int node)
827 {
828 size_t bytes;
829
830 if (unlikely(check_mul_overflow(n, size, &bytes)))
831 return NULL;
832
833 return kvmalloc_node_noprof(bytes, flags, node);
834 }
835
836 #define kvmalloc_array_noprof(...) kvmalloc_array_node_noprof(__VA_ARGS__, NUMA_NO_NODE)
837 #define kvcalloc_node_noprof(_n,_s,_f,_node) kvmalloc_array_node_noprof(_n,_s,(_f)|__GFP_ZERO,_node)
838 #define kvcalloc_noprof(...) kvcalloc_node_noprof(__VA_ARGS__, NUMA_NO_NODE)
839
840 #define kvmalloc_array(...) alloc_hooks(kvmalloc_array_noprof(__VA_ARGS__))
841 #define kvcalloc_node(...) alloc_hooks(kvcalloc_node_noprof(__VA_ARGS__))
842 #define kvcalloc(...) alloc_hooks(kvcalloc_noprof(__VA_ARGS__))
843
844 extern void *kvrealloc_noprof(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
845 __realloc_size(3);
846 #define kvrealloc(...) alloc_hooks(kvrealloc_noprof(__VA_ARGS__))
847
848 extern void kvfree(const void *addr);
849 DEFINE_FREE(kvfree, void *, if (!IS_ERR_OR_NULL(_T)) kvfree(_T))
850
851 extern void kvfree_sensitive(const void *addr, size_t len);
852
853 unsigned int kmem_cache_size(struct kmem_cache *s);
854
855 /**
856 * kmalloc_size_roundup - Report allocation bucket size for the given size
857 *
858 * @size: Number of bytes to round up from.
859 *
860 * This returns the number of bytes that would be available in a kmalloc()
861 * allocation of @size bytes. For example, a 126 byte request would be
862 * rounded up to the next sized kmalloc bucket, 128 bytes. (This is strictly
863 * for the general-purpose kmalloc()-based allocations, and is not for the
864 * pre-sized kmem_cache_alloc()-based allocations.)
865 *
866 * Use this to kmalloc() the full bucket size ahead of time instead of using
867 * ksize() to query the size after an allocation.
868 */
869 size_t kmalloc_size_roundup(size_t size);
870
871 void __init kmem_cache_init_late(void);
872
873 #endif /* _LINUX_SLAB_H */
874
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