From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754711Ab1KGLrA (ORCPT ); Mon, 7 Nov 2011 06:47:00 -0500 Received: from mga11.intel.com ([192.55.52.93]:6010 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752418Ab1KGLq7 (ORCPT ); Mon, 7 Nov 2011 06:46:59 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.69,469,1315206000"; d="scan'208";a="81955062" Date: Mon, 7 Nov 2011 11:58:02 +0000 From: Alan Cox To: Ilya Zykov Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: Re: PROBLEM: Race condition in tty buffer's function flush_to_ldisc(). Message-ID: <20111107115802.23201d45@bob.linux.org.uk> In-Reply-To: <4EB7BD9A.7070600@ilyx.ru> References: <4EB7BD9A.7070600@ilyx.ru> Organization: Intel X-Mailer: Claws Mail 3.7.9 (GTK+ 2.22.0; x86_64-redhat-linux-gnu) Organisation: Intel Corporation UK Ltd, registered no. 1134945 (England), Registered office Pipers Way, Swindon, SN3 1RJ Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 07 Nov 2011 15:14:34 +0400 Ilya Zykov wrote: > Function flush_to_ldisc() call disc->ops->receive_buf(), > without tty->buf.lock and with TTY_FLUSHING bit set. flush_to_ldisc is single threaded for a given tty. If you fail to ensure that is the case everything breaks. What cases does this occur ? Also for the other patches do you have benchmarks yet ? Alan