Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_STRING_64_H
3#define _ASM_X86_STRING_64_H
4
5#ifdef __KERNEL__
6#include <linux/jump_label.h>
7
8/* Written 2002 by Andi Kleen */
9
10/* Only used for special circumstances. Stolen from i386/string.h */
11static __always_inline void *__inline_memcpy(void *to, const void *from, size_t n)
12{
13 unsigned long d0, d1, d2;
14 asm volatile("rep ; movsl\n\t"
15 "testb $2,%b4\n\t"
16 "je 1f\n\t"
17 "movsw\n"
18 "1:\ttestb $1,%b4\n\t"
19 "je 2f\n\t"
20 "movsb\n"
21 "2:"
22 : "=&c" (d0), "=&D" (d1), "=&S" (d2)
23 : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
24 : "memory");
25 return to;
26}
27
28/* Even with __builtin_ the compiler may decide to use the out of line
29 function. */
30
31#define __HAVE_ARCH_MEMCPY 1
32extern void *memcpy(void *to, const void *from, size_t len);
33extern void *__memcpy(void *to, const void *from, size_t len);
34
35#ifndef CONFIG_FORTIFY_SOURCE
36#ifndef CONFIG_KMEMCHECK
37#if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4
38#define memcpy(dst, src, len) \
39({ \
40 size_t __len = (len); \
41 void *__ret; \
42 if (__builtin_constant_p(len) && __len >= 64) \
43 __ret = __memcpy((dst), (src), __len); \
44 else \
45 __ret = __builtin_memcpy((dst), (src), __len); \
46 __ret; \
47})
48#endif
49#else
50/*
51 * kmemcheck becomes very happy if we use the REP instructions unconditionally,
52 * because it means that we know both memory operands in advance.
53 */
54#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
55#endif
56#endif /* !CONFIG_FORTIFY_SOURCE */
57
58#define __HAVE_ARCH_MEMSET
59void *memset(void *s, int c, size_t n);
60void *__memset(void *s, int c, size_t n);
61
62#define __HAVE_ARCH_MEMSET16
63static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
64{
65 long d0, d1;
66 asm volatile("rep\n\t"
67 "stosw"
68 : "=&c" (d0), "=&D" (d1)
69 : "a" (v), "1" (s), "0" (n)
70 : "memory");
71 return s;
72}
73
74#define __HAVE_ARCH_MEMSET32
75static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
76{
77 long d0, d1;
78 asm volatile("rep\n\t"
79 "stosl"
80 : "=&c" (d0), "=&D" (d1)
81 : "a" (v), "1" (s), "0" (n)
82 : "memory");
83 return s;
84}
85
86#define __HAVE_ARCH_MEMSET64
87static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
88{
89 long d0, d1;
90 asm volatile("rep\n\t"
91 "stosq"
92 : "=&c" (d0), "=&D" (d1)
93 : "a" (v), "1" (s), "0" (n)
94 : "memory");
95 return s;
96}
97
98#define __HAVE_ARCH_MEMMOVE
99void *memmove(void *dest, const void *src, size_t count);
100void *__memmove(void *dest, const void *src, size_t count);
101
102int memcmp(const void *cs, const void *ct, size_t count);
103size_t strlen(const char *s);
104char *strcpy(char *dest, const char *src);
105char *strcat(char *dest, const char *src);
106int strcmp(const char *cs, const char *ct);
107
108#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
109
110/*
111 * For files that not instrumented (e.g. mm/slub.c) we
112 * should use not instrumented version of mem* functions.
113 */
114
115#undef memcpy
116#define memcpy(dst, src, len) __memcpy(dst, src, len)
117#define memmove(dst, src, len) __memmove(dst, src, len)
118#define memset(s, c, n) __memset(s, c, n)
119
120#ifndef __NO_FORTIFY
121#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
122#endif
123
124#endif
125
126#define __HAVE_ARCH_MEMCPY_MCSAFE 1
127__must_check int memcpy_mcsafe_unrolled(void *dst, const void *src, size_t cnt);
128DECLARE_STATIC_KEY_FALSE(mcsafe_key);
129
130/**
131 * memcpy_mcsafe - copy memory with indication if a machine check happened
132 *
133 * @dst: destination address
134 * @src: source address
135 * @cnt: number of bytes to copy
136 *
137 * Low level memory copy function that catches machine checks
138 * We only call into the "safe" function on systems that can
139 * actually do machine check recovery. Everyone else can just
140 * use memcpy().
141 *
142 * Return 0 for success, -EFAULT for fail
143 */
144static __always_inline __must_check int
145memcpy_mcsafe(void *dst, const void *src, size_t cnt)
146{
147#ifdef CONFIG_X86_MCE
148 if (static_branch_unlikely(&mcsafe_key))
149 return memcpy_mcsafe_unrolled(dst, src, cnt);
150 else
151#endif
152 memcpy(dst, src, cnt);
153 return 0;
154}
155
156#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
157#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
158void memcpy_flushcache(void *dst, const void *src, size_t cnt);
159#endif
160
161#endif /* __KERNEL__ */
162
163#endif /* _ASM_X86_STRING_64_H */