1 #ifndef _ASM_X86_UACCESS_32_H
2 #define _ASM_X86_UACCESS_32_H
5 * User space memory access functions
7 #include <linux/errno.h>
8 #include <linux/thread_info.h>
9 #include <linux/string.h>
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
);
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.
30 * Context: User context only.
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
35 * so that we don't result in page fault and sleep.
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.
43 static __always_inline
unsigned long __must_check
44 __copy_to_user_inatomic(void __user
*to
, const void *from
, unsigned long n
)
46 if (__builtin_constant_p(n
)) {
52 __put_user_size(*(u8
*)from
, (u8 __user
*)to
,
58 __put_user_size(*(u16
*)from
, (u16 __user
*)to
,
64 __put_user_size(*(u32
*)from
, (u32 __user
*)to
,
70 __put_user_size(*(u64
*)from
, (u64 __user
*)to
,
76 return __copy_to_user_ll(to
, from
, n
);
80 * __copy_to_user: - Copy a block of data into user space, with less checking.
81 * @to: Destination address, in user space.
82 * @from: Source address, in kernel space.
83 * @n: Number of bytes to copy.
85 * Context: User context only. This function may sleep if pagefaults are
88 * Copy data from kernel space to user space. Caller must check
89 * the specified block with access_ok() before calling this function.
91 * Returns number of bytes that could not be copied.
92 * On success, this will be zero.
94 static __always_inline
unsigned long __must_check
95 __copy_to_user(void __user
*to
, const void *from
, unsigned long n
)
98 return __copy_to_user_inatomic(to
, from
, n
);
101 static __always_inline
unsigned long
102 __copy_from_user_inatomic(void *to
, const void __user
*from
, unsigned long n
)
104 /* Avoid zeroing the tail if the copy fails..
105 * If 'n' is constant and 1, 2, or 4, we do still zero on a failure,
106 * but as the zeroing behaviour is only significant when n is not
107 * constant, that shouldn't be a problem.
109 if (__builtin_constant_p(n
)) {
115 __get_user_size(*(u8
*)to
, from
, 1, ret
, 1);
120 __get_user_size(*(u16
*)to
, from
, 2, ret
, 2);
125 __get_user_size(*(u32
*)to
, from
, 4, ret
, 4);
130 return __copy_from_user_ll_nozero(to
, from
, n
);
134 * __copy_from_user: - Copy a block of data from user space, with less checking.
135 * @to: Destination address, in kernel space.
136 * @from: Source address, in user space.
137 * @n: Number of bytes to copy.
139 * Context: User context only. This function may sleep if pagefaults are
142 * Copy data from user space to kernel space. Caller must check
143 * the specified block with access_ok() before calling this function.
145 * Returns number of bytes that could not be copied.
146 * On success, this will be zero.
148 * If some data could not be copied, this function will pad the copied
149 * data to the requested size using zero bytes.
151 * An alternate version - __copy_from_user_inatomic() - may be called from
152 * atomic context and will fail rather than sleep. In this case the
153 * uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h
154 * for explanation of why this is needed.
156 static __always_inline
unsigned long
157 __copy_from_user(void *to
, const void __user
*from
, unsigned long n
)
160 if (__builtin_constant_p(n
)) {
166 __get_user_size(*(u8
*)to
, from
, 1, ret
, 1);
171 __get_user_size(*(u16
*)to
, from
, 2, ret
, 2);
176 __get_user_size(*(u32
*)to
, from
, 4, ret
, 4);
181 return __copy_from_user_ll(to
, from
, n
);
184 static __always_inline
unsigned long __copy_from_user_nocache(void *to
,
185 const void __user
*from
, unsigned long n
)
188 if (__builtin_constant_p(n
)) {
194 __get_user_size(*(u8
*)to
, from
, 1, ret
, 1);
199 __get_user_size(*(u16
*)to
, from
, 2, ret
, 2);
204 __get_user_size(*(u32
*)to
, from
, 4, ret
, 4);
209 return __copy_from_user_ll_nocache(to
, from
, n
);
212 static __always_inline
unsigned long
213 __copy_from_user_inatomic_nocache(void *to
, const void __user
*from
,
216 return __copy_from_user_ll_nocache_nozero(to
, from
, n
);
219 #endif /* _ASM_X86_UACCESS_32_H */