rem: int rc;
add: status_t rc;
context: port_id	user_find_port(const char *port_name){	if(port_name != NULL) {		char name[SYS_MAX_OS_NAME_LEN];		int rc;		if((addr)port_name >= KERNEL_BASE && (addr)port_name <= KERNEL_TOP)			return ERR_VM_BAD_USER_MEMORY;		rc = user_strncpy(name, port_name, SYS_MAX_OS_NAME_LEN-1);		if(rc < 0)			return rc;		name[SYS_MAX_OS_NAME_LEN-1] = 0;		return find_port(name);	} else {		return EINVAL;	}}