extern int tty_check_change(struct tty_struct *tty);
extern void __stop_tty(struct tty_struct *tty);
extern void stop_tty(struct tty_struct *tty);
extern int tty_check_change(struct tty_struct *tty);
extern void __stop_tty(struct tty_struct *tty);
extern void stop_tty(struct tty_struct *tty);