extern int tty_standard_install(struct tty_driver *driver,
struct tty_struct *tty);
-extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
-extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
-
extern struct mutex tty_mutex;
extern spinlock_t tty_files_lock;