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 */