#define USER_ADDR_NULL ((user_addr_t) 0)
#define CAST_USER_ADDR_T(a_ptr) ((user_addr_t)((uintptr_t)(a_ptr)))
+/* This defines the size of syscall arguments after copying into the kernel: */
+typedef u_int64_t syscall_arg_t;
+
#ifndef __offsetof
#define __offsetof(type, field) ((size_t)(&((type *)0)->field))
#endif