rem: int					rc;
add: status_t 			rc;
context: int	user_get_port_info(port_id id, struct port_info *uinfo){	int 				res;	struct port_info	info;	int					rc;	if (uinfo == NULL)		return EINVAL;	if((addr)uinfo >= KERNEL_BASE && (addr)uinfo <= KERNEL_TOP)		return ERR_VM_BAD_USER_MEMORY;	res = get_port_info(id, &info);	// copy to userspace	rc = user_memcpy(uinfo, &info, sizeof(struct port_info));	if(rc < 0)		return rc;	return res;}