tools/virtio/linux/uaccess.h

   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 */