1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef UACCESS_H 3 #define UACCESS_H 4 5 #include <linux/compiler.h> 6 7 extern void *__user_addr_min, *__user_addr_max; 8 9 #define put_user(x, ptr) \ 10 ({ \ 11 typeof(ptr) __pu_ptr = (ptr); \ 12 __chk_user_ptr(__pu_ptr); \ 13 WRITE_ONCE(*(__pu_ptr), x); \ 14 0; \ 15 }) 16 17 #define get_user(x, ptr) \ 18 ({ \ 19 typeof(ptr) __pu_ptr = (ptr); \ 20 __chk_user_ptr(__pu_ptr); \ 21 x = READ_ONCE(*(__pu_ptr)); \ 22 0; \ 23 }) 24 25 static void volatile_memcpy(volatile char *to, const volatile char *from, 26 unsigned long n) 27 { 28 while (n--) 29 *(to++) = *(from++); 30 } 31 32 static inline int copy_from_user(void *to, const void __user volatile *from, 33 unsigned long n) 34 { 35 volatile_memcpy(to, from, n); 36 return 0; 37 } 38 39 static inline int copy_to_user(void __user volatile *to, const void *from, 40 unsigned long n) 41 { 42 volatile_memcpy(to, from, n); 43 return 0; 44 } 45 #endif /* UACCESS_H */ 46