diff --git a/sys/kern/tty.c b/sys/kern/tty.c index 2468e8859381..804635ebb540 100644 --- a/sys/kern/tty.c +++ b/sys/kern/tty.c @@ -206,6 +206,7 @@ ttydev_leave(struct tty *tp) ttydevsw_close(tp); tp->t_flags &= ~TF_OPENCLOSE; + cv_broadcast(&tp->t_dcdwait); tty_rel_free(tp); } @@ -231,13 +232,17 @@ ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td) tty_unlock(tp); return (ENXIO); } + /* - * Prevent the TTY from being opened when being torn down or - * built up by unrelated processes. + * Block when other processes are currently opening or closing + * the TTY. */ - if (tp->t_flags & TF_OPENCLOSE) { - tty_unlock(tp); - return (EBUSY); + while (tp->t_flags & TF_OPENCLOSE) { + error = tty_wait(tp, &tp->t_dcdwait); + if (error != 0) { + tty_unlock(tp); + return (error); + } } tp->t_flags |= TF_OPENCLOSE; @@ -299,6 +304,7 @@ ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td) tp->t_flags |= TF_OPENED_IN; done: tp->t_flags &= ~TF_OPENCLOSE; + cv_broadcast(&tp->t_dcdwait); ttydev_leave(tp); return (error);