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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
24enum _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
230struct list_lru;
231struct mem_cgroup;
232/*
233 * struct kmem_cache related prototypes
234 */
235bool slab_is_available(void);
236
237struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
238 unsigned int align, slab_flags_t flags,
239 void (*ctor)(void *));
240struct 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 *));
245void kmem_cache_destroy(struct kmem_cache *s);
246int 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 */
274void * __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
278void kfree(const void *objp);
279void kfree_sensitive(const void *objp);
280size_t __ksize(const void *objp);
281
282DEFINE_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 */
296size_t ksize(const void *objp);
297
298#ifdef CONFIG_PRINTK
299bool kmem_dump_obj(void *object);
300#else
301static 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
337static 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 */
405enum 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
429typedef struct kmem_cache * kmem_buckets[KMALLOC_SHIFT_HIGH + 1];
430
431extern 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
441extern unsigned long random_kmalloc_seed;
442
443static __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 */
486static __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}
527static_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 */
542void *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
546void *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
550void kmem_cache_free(struct kmem_cache *s, void *objp);
551
552kmem_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 */
563void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p);
564
565int 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
568static __always_inline void kfree_bulk(size_t size, void **p)
569{
570 kmem_cache_free_bulk(NULL, size, p);
571}
572
573void *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
598void *__kmalloc_noprof(size_t size, gfp_t flags)
599 __assume_kmalloc_alignment __alloc_size(1);
600
601void *__kmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node)
602 __assume_kmalloc_alignment __alloc_size(1);
603
604void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
605 __assume_kmalloc_alignment __alloc_size(3);
606
607void *__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
611void *__kmalloc_large_noprof(size_t size, gfp_t flags)
612 __assume_page_alignment __alloc_size(1);
613
614void *__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 */
672static __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
695static __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 */
718static 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 */
737static 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
759void *__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
779static 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 */
805static 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
812void *__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
825static inline __alloc_size(1, 2) void *
826kvmalloc_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
844extern 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
848extern void kvfree(const void *addr);
849DEFINE_FREE(kvfree, void *, if (!IS_ERR_OR_NULL(_T)) kvfree(_T))
850
851extern void kvfree_sensitive(const void *addr, size_t len);
852
853unsigned 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 */
869size_t kmalloc_size_roundup(size_t size);
870
871void __init kmem_cache_init_late(void);
872
873#endif /* _LINUX_SLAB_H */