1 #ifndef UACCESS_H 2 #define UACCESS_H 3 4 #include <linux/compiler.h> 5 6 extern void *__user_addr_min, *__user_addr_max; 7 8 static inline void __chk_user_ptr(const volatile void *p, size_t size) 9 { 10 assert(p >= __user_addr_min && p + size <= __user_addr_max); 11 } 12 13 #define put_user(x, ptr) \ 14 ({ \ 15 typeof(ptr) __pu_ptr = (ptr); \ 16 __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \ 17 WRITE_ONCE(*(__pu_ptr), x); \ 18 0; \ 19 }) 20 21 #define get_user(x, ptr) \ 22 ({ \ 23 typeof(ptr) __pu_ptr = (ptr); \ 24 __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \ 25 x = READ_ONCE(*(__pu_ptr)); \ 26 0; \ 27 }) 28 29 static void volatile_memcpy(volatile char *to, const volatile char *from, 30 unsigned long n) 31 { 32 while (n--) 33 *(to++) = *(from++); 34 } 35 36 static inline int copy_from_user(void *to, const void __user volatile *from, 37 unsigned long n) 38 { 39 __chk_user_ptr(from, n); 40 volatile_memcpy(to, from, n); 41 return 0; 42 } 43 44 static inline int copy_to_user(void __user volatile *to, const void *from, 45 unsigned long n) 46 { 47 __chk_user_ptr(to, n); 48 volatile_memcpy(to, from, n); 49 return 0; 50 } 51 #endif /* UACCESS_H */ 52