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1965aae3 PA |
1 | #ifndef _ASM_X86_UACCESS_32_H |
2 | #define _ASM_X86_UACCESS_32_H | |
1da177e4 LT |
3 | |
4 | /* | |
5 | * User space memory access functions | |
6 | */ | |
1da177e4 LT |
7 | #include <linux/errno.h> |
8 | #include <linux/thread_info.h> | |
1da177e4 | 9 | #include <linux/string.h> |
14e6d17d | 10 | #include <asm/asm.h> |
1da177e4 LT |
11 | #include <asm/page.h> |
12 | ||
b1fcec7f JP |
13 | unsigned long __must_check __copy_to_user_ll |
14 | (void __user *to, const void *from, unsigned long n); | |
15 | unsigned long __must_check __copy_from_user_ll | |
16 | (void *to, const void __user *from, unsigned long n); | |
17 | unsigned long __must_check __copy_from_user_ll_nozero | |
18 | (void *to, const void __user *from, unsigned long n); | |
19 | unsigned long __must_check __copy_from_user_ll_nocache | |
20 | (void *to, const void __user *from, unsigned long n); | |
21 | unsigned long __must_check __copy_from_user_ll_nocache_nozero | |
22 | (void *to, const void __user *from, unsigned long n); | |
1da177e4 | 23 | |
6d1c4261 AK |
24 | /** |
25 | * __copy_to_user_inatomic: - Copy a block of data into user space, with less checking. | |
26 | * @to: Destination address, in user space. | |
27 | * @from: Source address, in kernel space. | |
28 | * @n: Number of bytes to copy. | |
29 | * | |
30 | * Context: User context only. | |
31 | * | |
32 | * Copy data from kernel space to user space. Caller must check | |
33 | * the specified block with access_ok() before calling this function. | |
34 | * The caller should also make sure he pins the user space address | |
4fe48782 | 35 | * so that we don't result in page fault and sleep. |
6d1c4261 | 36 | * |
1da177e4 LT |
37 | * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault |
38 | * we return the initial request size (1, 2 or 4), as copy_*_user should do. | |
39 | * If a store crosses a page boundary and gets a fault, the x86 will not write | |
40 | * anything, so this is accurate. | |
41 | */ | |
42 | ||
652050ae | 43 | static __always_inline unsigned long __must_check |
1da177e4 LT |
44 | __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) |
45 | { | |
46 | if (__builtin_constant_p(n)) { | |
47 | unsigned long ret; | |
48 | ||
49 | switch (n) { | |
50 | case 1: | |
b1fcec7f JP |
51 | __put_user_size(*(u8 *)from, (u8 __user *)to, |
52 | 1, ret, 1); | |
1da177e4 LT |
53 | return ret; |
54 | case 2: | |
b1fcec7f JP |
55 | __put_user_size(*(u16 *)from, (u16 __user *)to, |
56 | 2, ret, 2); | |
1da177e4 LT |
57 | return ret; |
58 | case 4: | |
b1fcec7f JP |
59 | __put_user_size(*(u32 *)from, (u32 __user *)to, |
60 | 4, ret, 4); | |
1da177e4 | 61 | return ret; |
6a907738 CW |
62 | case 8: |
63 | __put_user_size(*(u64 *)from, (u64 __user *)to, | |
64 | 8, ret, 8); | |
65 | return ret; | |
1da177e4 LT |
66 | } |
67 | } | |
68 | return __copy_to_user_ll(to, from, n); | |
69 | } | |
70 | ||
1da177e4 | 71 | /** |
9c7fff6e RD |
72 | * __copy_to_user: - Copy a block of data into user space, with less checking. |
73 | * @to: Destination address, in user space. | |
74 | * @from: Source address, in kernel space. | |
1da177e4 LT |
75 | * @n: Number of bytes to copy. |
76 | * | |
b3c395ef DH |
77 | * Context: User context only. This function may sleep if pagefaults are |
78 | * enabled. | |
1da177e4 | 79 | * |
9c7fff6e | 80 | * Copy data from kernel space to user space. Caller must check |
1da177e4 LT |
81 | * the specified block with access_ok() before calling this function. |
82 | * | |
83 | * Returns number of bytes that could not be copied. | |
84 | * On success, this will be zero. | |
1da177e4 | 85 | */ |
9c7fff6e RD |
86 | static __always_inline unsigned long __must_check |
87 | __copy_to_user(void __user *to, const void *from, unsigned long n) | |
88 | { | |
3ee1afa3 | 89 | might_fault(); |
c10d38dd | 90 | return __copy_to_user_inatomic(to, from, n); |
9c7fff6e RD |
91 | } |
92 | ||
652050ae | 93 | static __always_inline unsigned long |
1da177e4 LT |
94 | __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) |
95 | { | |
7c12d811 N |
96 | /* Avoid zeroing the tail if the copy fails.. |
97 | * If 'n' is constant and 1, 2, or 4, we do still zero on a failure, | |
98 | * but as the zeroing behaviour is only significant when n is not | |
99 | * constant, that shouldn't be a problem. | |
100 | */ | |
101 | if (__builtin_constant_p(n)) { | |
102 | unsigned long ret; | |
103 | ||
104 | switch (n) { | |
105 | case 1: | |
106 | __get_user_size(*(u8 *)to, from, 1, ret, 1); | |
107 | return ret; | |
108 | case 2: | |
109 | __get_user_size(*(u16 *)to, from, 2, ret, 2); | |
110 | return ret; | |
111 | case 4: | |
112 | __get_user_size(*(u32 *)to, from, 4, ret, 4); | |
113 | return ret; | |
114 | } | |
115 | } | |
116 | return __copy_from_user_ll_nozero(to, from, n); | |
117 | } | |
9c7fff6e RD |
118 | |
119 | /** | |
120 | * __copy_from_user: - Copy a block of data from user space, with less checking. | |
121 | * @to: Destination address, in kernel space. | |
122 | * @from: Source address, in user space. | |
123 | * @n: Number of bytes to copy. | |
124 | * | |
b3c395ef DH |
125 | * Context: User context only. This function may sleep if pagefaults are |
126 | * enabled. | |
9c7fff6e RD |
127 | * |
128 | * Copy data from user space to kernel space. Caller must check | |
129 | * the specified block with access_ok() before calling this function. | |
130 | * | |
131 | * Returns number of bytes that could not be copied. | |
132 | * On success, this will be zero. | |
133 | * | |
134 | * If some data could not be copied, this function will pad the copied | |
135 | * data to the requested size using zero bytes. | |
136 | * | |
137 | * An alternate version - __copy_from_user_inatomic() - may be called from | |
138 | * atomic context and will fail rather than sleep. In this case the | |
139 | * uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h | |
140 | * for explanation of why this is needed. | |
141 | */ | |
7c12d811 N |
142 | static __always_inline unsigned long |
143 | __copy_from_user(void *to, const void __user *from, unsigned long n) | |
144 | { | |
3ee1afa3 | 145 | might_fault(); |
1da177e4 LT |
146 | if (__builtin_constant_p(n)) { |
147 | unsigned long ret; | |
148 | ||
149 | switch (n) { | |
150 | case 1: | |
151 | __get_user_size(*(u8 *)to, from, 1, ret, 1); | |
152 | return ret; | |
153 | case 2: | |
154 | __get_user_size(*(u16 *)to, from, 2, ret, 2); | |
155 | return ret; | |
156 | case 4: | |
157 | __get_user_size(*(u32 *)to, from, 4, ret, 4); | |
158 | return ret; | |
159 | } | |
160 | } | |
161 | return __copy_from_user_ll(to, from, n); | |
162 | } | |
163 | ||
7c12d811 | 164 | static __always_inline unsigned long __copy_from_user_nocache(void *to, |
c22ce143 HY |
165 | const void __user *from, unsigned long n) |
166 | { | |
3ee1afa3 | 167 | might_fault(); |
c22ce143 HY |
168 | if (__builtin_constant_p(n)) { |
169 | unsigned long ret; | |
170 | ||
171 | switch (n) { | |
172 | case 1: | |
173 | __get_user_size(*(u8 *)to, from, 1, ret, 1); | |
174 | return ret; | |
175 | case 2: | |
176 | __get_user_size(*(u16 *)to, from, 2, ret, 2); | |
177 | return ret; | |
178 | case 4: | |
179 | __get_user_size(*(u32 *)to, from, 4, ret, 4); | |
180 | return ret; | |
181 | } | |
182 | } | |
183 | return __copy_from_user_ll_nocache(to, from, n); | |
184 | } | |
185 | ||
652050ae | 186 | static __always_inline unsigned long |
b1fcec7f JP |
187 | __copy_from_user_inatomic_nocache(void *to, const void __user *from, |
188 | unsigned long n) | |
1da177e4 | 189 | { |
7c12d811 | 190 | return __copy_from_user_ll_nocache_nozero(to, from, n); |
c22ce143 HY |
191 | } |
192 | ||
1965aae3 | 193 | #endif /* _ASM_X86_UACCESS_32_H */ |