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Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_UACCESS_64_H
3#define _ASM_X86_UACCESS_64_H
4
5/*
6 * User space memory access functions
7 */
8#include <linux/compiler.h>
9#include <linux/lockdep.h>
10#include <linux/kasan-checks.h>
11#include <asm/alternative.h>
12#include <asm/cpufeatures.h>
13#include <asm/page.h>
14
15/*
16 * Copy To/From Userspace
17 */
18
19/* Handles exceptions in both to and from, but doesn't do access_ok */
20__must_check unsigned long
21copy_user_enhanced_fast_string(void *to, const void *from, unsigned len);
22__must_check unsigned long
23copy_user_generic_string(void *to, const void *from, unsigned len);
24__must_check unsigned long
25copy_user_generic_unrolled(void *to, const void *from, unsigned len);
26
27static __always_inline __must_check unsigned long
28copy_user_generic(void *to, const void *from, unsigned len)
29{
30 unsigned ret;
31
32 /*
33 * If CPU has ERMS feature, use copy_user_enhanced_fast_string.
34 * Otherwise, if CPU has rep_good feature, use copy_user_generic_string.
35 * Otherwise, use copy_user_generic_unrolled.
36 */
37 alternative_call_2(copy_user_generic_unrolled,
38 copy_user_generic_string,
39 X86_FEATURE_REP_GOOD,
40 copy_user_enhanced_fast_string,
41 X86_FEATURE_ERMS,
42 ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from),
43 "=d" (len)),
44 "1" (to), "2" (from), "3" (len)
45 : "memory", "rcx", "r8", "r9", "r10", "r11");
46 return ret;
47}
48
49static __always_inline __must_check unsigned long
50copy_to_user_mcsafe(void *to, const void *from, unsigned len)
51{
52 unsigned long ret;
53
54 __uaccess_begin();
55 /*
56 * Note, __memcpy_mcsafe() is explicitly used since it can
57 * handle exceptions / faults. memcpy_mcsafe() may fall back to
58 * memcpy() which lacks this handling.
59 */
60 ret = __memcpy_mcsafe(to, from, len);
61 __uaccess_end();
62 return ret;
63}
64
65static __always_inline __must_check unsigned long
66raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
67{
68 return copy_user_generic(dst, (__force void *)src, size);
69}
70
71static __always_inline __must_check unsigned long
72raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
73{
74 return copy_user_generic((__force void *)dst, src, size);
75}
76
77static __always_inline __must_check
78unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigned long size)
79{
80 return copy_user_generic((__force void *)dst,
81 (__force void *)src, size);
82}
83
84extern long __copy_user_nocache(void *dst, const void __user *src,
85 unsigned size, int zerorest);
86
87extern long __copy_user_flushcache(void *dst, const void __user *src, unsigned size);
88extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
89 size_t len);
90
91static inline int
92__copy_from_user_inatomic_nocache(void *dst, const void __user *src,
93 unsigned size)
94{
95 kasan_check_write(dst, size);
96 return __copy_user_nocache(dst, src, size, 0);
97}
98
99static inline int
100__copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
101{
102 kasan_check_write(dst, size);
103 return __copy_user_flushcache(dst, src, size);
104}
105
106unsigned long
107mcsafe_handle_tail(char *to, char *from, unsigned len);
108
109#endif /* _ASM_X86_UACCESS_64_H */