From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753144Ab3FYSzi (ORCPT ); Tue, 25 Jun 2013 14:55:38 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41117 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752742Ab3FYSeS (ORCPT ); Tue, 25 Jun 2013 14:34:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Markus Trippelsdorf , Peter Hurley , Mikael Pettersson Subject: [ 88/95] tty: Fix transient pty write() EIO Date: Tue, 25 Jun 2013 11:33:15 -0700 Message-Id: <20130625182203.590304094@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130625182153.605455184@linuxfoundation.org> References: <20130625182153.605455184@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Hurley commit 7c61c3d8f44d5d822f758754287af644307b4af9 upstream. Commit 699390354da6c258b65bf8fa79cfd5feaede50b6 ('pty: Ignore slave pty close() if never successfully opened') introduced a bug with ptys whereby a write() in parallel with an open() on an existing pty could mistakenly indicate an I/O error. Only indicate an I/O error if the condition on open() actually exists. Reported-by: Markus Trippelsdorf Signed-off-by: Peter Hurley Tested-by: Mikael Pettersson Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -244,14 +244,9 @@ static void pty_flush_buffer(struct tty_ static int pty_open(struct tty_struct *tty, struct file *filp) { - int retval = -ENODEV; - if (!tty || !tty->link) - goto out; - - set_bit(TTY_IO_ERROR, &tty->flags); + return -ENODEV; - retval = -EIO; if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) goto out; if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) @@ -262,9 +257,11 @@ static int pty_open(struct tty_struct *t clear_bit(TTY_IO_ERROR, &tty->flags); clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); set_bit(TTY_THROTTLED, &tty->flags); - retval = 0; + return 0; + out: - return retval; + set_bit(TTY_IO_ERROR, &tty->flags); + return -EIO; } static void pty_set_termios(struct tty_struct *tty,