From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030183AbVKPFzh (ORCPT ); Wed, 16 Nov 2005 00:55:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030184AbVKPFzh (ORCPT ); Wed, 16 Nov 2005 00:55:37 -0500 Received: from mx2.suse.de ([195.135.220.15]:8333 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1030183AbVKPFzg (ORCPT ); Wed, 16 Nov 2005 00:55:36 -0500 To: Steven Rostedt Cc: pavel@suse.cz, LKML , Ingo Molnar , Thomas Gleixner Subject: Re: [PATCH -rt] race condition in fs/compat.c with compat_sys_ioctl References: <1131821278.5047.8.camel@localhost.localdomain> <5bdc1c8b0511121725u6df7ad9csb9cb56777fa6fe64@mail.gmail.com> <5bdc1c8b0511121914v12dc4402u424fbaf416bf3710@mail.gmail.com> <1131853456.5047.14.camel@localhost.localdomain> <5bdc1c8b0511130634h501fb565v58906bdfae788814@mail.gmail.com> <1131994030.5047.17.camel@localhost.localdomain> <5bdc1c8b0511141057l60a2e778x89155cd5484d532f@mail.gmail.com> <1132115386.5047.61.camel@localhost.localdomain> From: Andi Kleen Date: 16 Nov 2005 06:55:28 +0100 In-Reply-To: <1132115386.5047.61.camel@localhost.localdomain> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Steven Rostedt writes: > > That's the problem. I found out that one ioctl might sleep holding the > sem and won't be woken up until another process calls another ioctl to > wake it up. But unfortunately, the one waking up the sleeper will block > on the sem. (the killer was tty_wait_until_sent) You should have looked into mainline first. The semaphore is already gone because it wasn't even needed anymore. -Andi