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Linux kernel mirror (for testing)
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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
50raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
51{
52 return copy_user_generic(dst, (__force void *)src, size);
53}
54
55static __always_inline __must_check unsigned long
56raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
57{
58 return copy_user_generic((__force void *)dst, src, size);
59}
60
61extern long __copy_user_nocache(void *dst, const void __user *src,
62 unsigned size, int zerorest);
63
64extern long __copy_user_flushcache(void *dst, const void __user *src, unsigned size);
65extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
66 size_t len);
67
68static inline int
69__copy_from_user_inatomic_nocache(void *dst, const void __user *src,
70 unsigned size)
71{
72 kasan_check_write(dst, size);
73 return __copy_user_nocache(dst, src, size, 0);
74}
75
76static inline int
77__copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
78{
79 kasan_check_write(dst, size);
80 return __copy_user_flushcache(dst, src, size);
81}
82#endif /* _ASM_X86_UACCESS_64_H */