From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754724Ab2LSTij (ORCPT ); Wed, 19 Dec 2012 14:38:39 -0500 Received: from 95-31-19-74.broadband.corbina.ru ([95.31.19.74]:60482 "EHLO 95-31-19-74.broadband.corbina.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751614Ab2LSTib (ORCPT ); Wed, 19 Dec 2012 14:38:31 -0500 Message-ID: <50D217B4.6000104@ilyx.ru> Date: Wed, 19 Dec 2012 23:38:28 +0400 From: Ilya Zykov User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Alan Cox CC: Greg Kroah-Hartman , Alan Cox , Jiri Slaby , Peter Hurley , Sasha Levin , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tty: Fix unreasonable write toward closed pty. References: <50D20E87.9060403@ilyx.ru> <20121219191030.4ee20a1c@pyramind.ukuu.org.uk> In-Reply-To: <20121219191030.4ee20a1c@pyramind.ukuu.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19.12.2012 23:10, Alan Cox wrote: >> diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c >> index a82b399..1ce1362 100644 >> --- a/drivers/tty/pty.c >> +++ b/drivers/tty/pty.c >> @@ -116,6 +116,8 @@ static int pty_space(struct tty_struct *to) >> >> static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) >> { >> + if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) >> + return -EIO; > > The flag can change between the test and ny further code being executed ? > > Alan > Yes, if I understand you correctly, but this is no matter here, because ldisc's layer will wait, flush this data later. Here, only beginning stage of tty_close. This is safe later stage from unnecessary data. Ilya