extern dev_t tty_devnum(struct tty_struct *tty);
extern void proc_clear_tty(struct task_struct *p);
-extern void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
extern void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
extern struct tty_struct *get_current_tty(void);