From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1CxBjw-0004Vt-C8 for user-mode-linux-devel@lists.sourceforge.net; Fri, 04 Feb 2005 14:15:48 -0800 Received: from smtp204.mail.sc5.yahoo.com ([216.136.130.127]) by sc8-sf-mx1.sourceforge.net with smtp (Exim 4.41) id 1CxBju-0007fR-Ki for user-mode-linux-devel@lists.sourceforge.net; Fri, 04 Feb 2005 14:15:48 -0800 Message-ID: <4203F40C.8040707@yahoo.com.au> From: Nick Piggin MIME-Version: 1.0 References: <42021E35.8050601@fujitsu-siemens.com> <4202C18F.5010605@yahoo.com.au> <42036C2C.5040503@fujitsu-siemens.com> In-Reply-To: <42036C2C.5040503@fujitsu-siemens.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: [uml-devel] Re: Race condition in ptrace Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sat, 05 Feb 2005 09:15:40 +1100 To: Bodo Stroesser Cc: Roland Mc Grath , Jeff Dike , BlaisorBlade , user-mode-linux devel , linux-kernel@vger.kernel.org, Andrew Morton Bodo Stroesser wrote: > Nick Piggin wrote: > >> Bodo Stroesser wrote: >> I don't see how this could help because AFAIKS, child->saving is only >> set and cleared while the runqueue is locked. And the same runqueue lock >> is taken by wait_task_inactive. >> > > Sorry, that not right. There are some routines called by sched(), that > release > and reacquire the runqueue lock. > Oh yeah, it is the wake_sleeping_dependent / dependent_sleeper crap. Sorry, you are right. And that's definitely a bug in sched.c, because it breaks wait_task_inactive, as you've rightly observed. Andrew, IMO this is another bug to hold 2.6.11 for. ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261559AbVBEAe1 (ORCPT ); Fri, 4 Feb 2005 19:34:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265039AbVBDWtv (ORCPT ); Fri, 4 Feb 2005 17:49:51 -0500 Received: from smtp204.mail.sc5.yahoo.com ([216.136.130.127]:25021 "HELO smtp204.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S263197AbVBDWPw (ORCPT ); Fri, 4 Feb 2005 17:15:52 -0500 Message-ID: <4203F40C.8040707@yahoo.com.au> Date: Sat, 05 Feb 2005 09:15:40 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20050105 Debian/1.7.5-1 X-Accept-Language: en MIME-Version: 1.0 To: Bodo Stroesser CC: Roland Mc Grath , Jeff Dike , BlaisorBlade , user-mode-linux devel , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: Race condition in ptrace References: <42021E35.8050601@fujitsu-siemens.com> <4202C18F.5010605@yahoo.com.au> <42036C2C.5040503@fujitsu-siemens.com> In-Reply-To: <42036C2C.5040503@fujitsu-siemens.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bodo Stroesser wrote: > Nick Piggin wrote: > >> Bodo Stroesser wrote: >> I don't see how this could help because AFAIKS, child->saving is only >> set and cleared while the runqueue is locked. And the same runqueue lock >> is taken by wait_task_inactive. >> > > Sorry, that not right. There are some routines called by sched(), that > release > and reacquire the runqueue lock. > Oh yeah, it is the wake_sleeping_dependent / dependent_sleeper crap. Sorry, you are right. And that's definitely a bug in sched.c, because it breaks wait_task_inactive, as you've rightly observed. Andrew, IMO this is another bug to hold 2.6.11 for.