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
__chk_user_ptr(const volatile void * p,size_t size)9 static inline void __chk_user_ptr(const volatile void *p, size_t size)
10 {
11 assert(p >= __user_addr_min && p + size <= __user_addr_max);
12 }
13
14 #define put_user(x, ptr) \
15 ({ \
16 typeof(ptr) __pu_ptr = (ptr); \
17 __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \
18 WRITE_ONCE(*(__pu_ptr), x); \
19 0; \
20 })
21
22 #define get_user(x, ptr) \
23 ({ \
24 typeof(ptr) __pu_ptr = (ptr); \
25 __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \
26 x = READ_ONCE(*(__pu_ptr)); \
27 0; \
28 })
29
volatile_memcpy(volatile char * to,const volatile char * from,unsigned long n)30 static void volatile_memcpy(volatile char *to, const volatile char *from,
31 unsigned long n)
32 {
33 while (n--)
34 *(to++) = *(from++);
35 }
36
copy_from_user(void * to,const void __user volatile * from,unsigned long n)37 static inline int copy_from_user(void *to, const void __user volatile *from,
38 unsigned long n)
39 {
40 __chk_user_ptr(from, n);
41 volatile_memcpy(to, from, n);
42 return 0;
43 }
44
copy_to_user(void __user volatile * to,const void * from,unsigned long n)45 static inline int copy_to_user(void __user volatile *to, const void *from,
46 unsigned long n)
47 {
48 __chk_user_ptr(to, n);
49 volatile_memcpy(to, from, n);
50 return 0;
51 }
52 #endif /* UACCESS_H */
53
