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