blob: 0a578fe18653b8b282af9ee101da0a558da222ba [file] [log] [blame]
Rusty Russell61d0b5a42013-03-18 13:22:19 +10301#ifndef UACCESS_H
2#define UACCESS_H
3extern void *__user_addr_min, *__user_addr_max;
4
5#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
6
7static 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
28static void volatile_memcpy(volatile char *to, const volatile char *from,
29 unsigned long n)
30{
31 while (n--)
32 *(to++) = *(from++);
33}
34
35static 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
43static 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 */