From: Peter Hurley Subject: [PATCH -next v2 05/26] tty: Check tty->count instead of TTY_CLOSING in tty_reopen() Date: Wed, 5 Nov 2014 12:12:48 -0500 Message-ID: <1415207589-15967-6-git-send-email-peter@hurleysoftware.com> References: <1413491125-20134-1-git-send-email-peter@hurleysoftware.com> <1415207589-15967-1-git-send-email-peter@hurleysoftware.com> Return-path: In-Reply-To: <1415207589-15967-1-git-send-email-peter@hurleysoftware.com> Sender: linux-kernel-owner@vger.kernel.org To: Greg Kroah-Hartman Cc: Jiri Slaby , One Thousand Gnomes , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Peter Hurley List-Id: linux-serial@vger.kernel.org Although perhaps not obvious, the TTY_CLOSING bit is set when the tty count has been decremented to 0 (which occurs while holding tty_lock). The only other case when tty count is 0 during a re-open is when a legacy BSD pty master has been opened in parallel but after the pty slave, which is unsupported and returns an error. Thus !tty->count contains the complete set of degenerate conditions under which a tty open fails. Reviewed-by: Alan Cox Signed-off-by: Peter Hurley --- drivers/tty/tty_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 6dc3fa0..97445c2 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1452,7 +1452,7 @@ static int tty_reopen(struct tty_struct *tty) { struct tty_driver *driver = tty->driver; - if (test_bit(TTY_CLOSING, &tty->flags)) + if (!tty->count) return -EIO; if (driver->type == TTY_DRIVER_TYPE_PTY && -- 2.1.3