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