__large_struct
#define __m(x) (*(struct __large_struct __user *)(x))
#define __m(x) (*(struct __large_struct __user *)(x))
#define __m(x) (*(struct __large_struct __user *)(x))
#define __m(x) (*(struct __large_struct *)(x))
#define __m(x) (*(struct __large_struct __user *)(x))
#define __m(x) ((struct __large_struct __user *)(x))
#define __m(x) ((struct __large_struct *)(x))
#define __m(x) (*(struct __large_struct __user *)(x))