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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_GENERIC_UACCESS_H
3 #define __ASM_GENERIC_UACCESS_H
6 * User space memory access functions, these should work
7 * on any machine that has kernel and user data in the same
8 * address space, e.g. all NOMMU machines.
10 #include <linux/string.h>
12 #ifdef CONFIG_UACCESS_MEMCPY
13 #include <asm/unaligned.h>
15 static __always_inline
int
16 __get_user_fn(size_t size
, const void __user
*from
, void *to
)
18 BUILD_BUG_ON(!__builtin_constant_p(size
));
22 *(u8
*)to
= *((u8 __force
*)from
);
25 *(u16
*)to
= get_unaligned((u16 __force
*)from
);
28 *(u32
*)to
= get_unaligned((u32 __force
*)from
);
31 *(u64
*)to
= get_unaligned((u64 __force
*)from
);
39 #define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
41 static __always_inline
int
42 __put_user_fn(size_t size
, void __user
*to
, void *from
)
44 BUILD_BUG_ON(!__builtin_constant_p(size
));
48 *(u8 __force
*)to
= *(u8
*)from
;
51 put_unaligned(*(u16
*)from
, (u16 __force
*)to
);
54 put_unaligned(*(u32
*)from
, (u32 __force
*)to
);
57 put_unaligned(*(u64
*)from
, (u64 __force
*)to
);
64 #define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
66 #define __get_kernel_nofault(dst, src, type, err_label) \
68 *((type *)dst) = get_unaligned((type *)(src)); \
69 if (0) /* make sure the label looks used to the compiler */ \
73 #define __put_kernel_nofault(dst, src, type, err_label) \
75 put_unaligned(*((type *)src), (type *)(dst)); \
76 if (0) /* make sure the label looks used to the compiler */ \
80 #define HAVE_GET_KERNEL_NOFAULT 1
82 static inline __must_check
unsigned long
83 raw_copy_from_user(void *to
, const void __user
* from
, unsigned long n
)
85 memcpy(to
, (const void __force
*)from
, n
);
89 static inline __must_check
unsigned long
90 raw_copy_to_user(void __user
*to
, const void *from
, unsigned long n
)
92 memcpy((void __force
*)to
, from
, n
);
95 #define INLINE_COPY_FROM_USER
96 #define INLINE_COPY_TO_USER
97 #endif /* CONFIG_UACCESS_MEMCPY */
100 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
103 #define KERNEL_DS MAKE_MM_SEG(~0UL)
107 #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
111 #define get_fs() (current_thread_info()->addr_limit)
113 static inline void set_fs(mm_segment_t fs
)
115 current_thread_info()->addr_limit
= fs
;
119 #ifndef uaccess_kernel
120 #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
123 #ifndef user_addr_max
124 #define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)
127 #endif /* CONFIG_SET_FS */
129 #define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))
132 * The architecture should really override this if possible, at least
133 * doing a check on the get_fs()
136 static inline int __access_ok(unsigned long addr
, unsigned long size
)
143 * These are the main single-value transfer routines. They automatically
144 * use the right size if we just have the right pointer type.
145 * This version just falls back to copy_{from,to}_user, which should
146 * provide a fast-path for small values.
148 #define __put_user(x, ptr) \
150 __typeof__(*(ptr)) __x = (x); \
151 int __pu_err = -EFAULT; \
152 __chk_user_ptr(ptr); \
153 switch (sizeof (*(ptr))) { \
158 __pu_err = __put_user_fn(sizeof (*(ptr)), \
168 #define put_user(x, ptr) \
170 void __user *__p = (ptr); \
172 access_ok(__p, sizeof(*ptr)) ? \
173 __put_user((x), ((__typeof__(*(ptr)) __user *)__p)) : \
177 #ifndef __put_user_fn
179 static inline int __put_user_fn(size_t size
, void __user
*ptr
, void *x
)
181 return unlikely(raw_copy_to_user(ptr
, x
, size
)) ? -EFAULT
: 0;
184 #define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
188 extern int __put_user_bad(void) __attribute__((noreturn
));
190 #define __get_user(x, ptr) \
192 int __gu_err = -EFAULT; \
193 __chk_user_ptr(ptr); \
194 switch (sizeof(*(ptr))) { \
196 unsigned char __x = 0; \
197 __gu_err = __get_user_fn(sizeof (*(ptr)), \
199 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
203 unsigned short __x = 0; \
204 __gu_err = __get_user_fn(sizeof (*(ptr)), \
206 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
210 unsigned int __x = 0; \
211 __gu_err = __get_user_fn(sizeof (*(ptr)), \
213 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
217 unsigned long long __x = 0; \
218 __gu_err = __get_user_fn(sizeof (*(ptr)), \
220 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
230 #define get_user(x, ptr) \
232 const void __user *__p = (ptr); \
234 access_ok(__p, sizeof(*ptr)) ? \
235 __get_user((x), (__typeof__(*(ptr)) __user *)__p) :\
236 ((x) = (__typeof__(*(ptr)))0,-EFAULT); \
239 #ifndef __get_user_fn
240 static inline int __get_user_fn(size_t size
, const void __user
*ptr
, void *x
)
242 return unlikely(raw_copy_from_user(x
, ptr
, size
)) ? -EFAULT
: 0;
245 #define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
249 extern int __get_user_bad(void) __attribute__((noreturn
));
255 static inline __must_check
unsigned long
256 __clear_user(void __user
*to
, unsigned long n
)
258 memset((void __force
*)to
, 0, n
);
263 static inline __must_check
unsigned long
264 clear_user(void __user
*to
, unsigned long n
)
267 if (!access_ok(to
, n
))
270 return __clear_user(to
, n
);
273 #include <asm/extable.h>
275 __must_check
long strncpy_from_user(char *dst
, const char __user
*src
,
277 __must_check
long strnlen_user(const char __user
*src
, long n
);
279 #endif /* __ASM_GENERIC_UACCESS_H */