From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754572Ab2I0PFs (ORCPT ); Thu, 27 Sep 2012 11:05:48 -0400 Received: from terminus.zytor.com ([198.137.202.10]:59071 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752552Ab2I0PFq (ORCPT ); Thu, 27 Sep 2012 11:05:46 -0400 Message-ID: <50646B3C.8000509@zytor.com> Date: Thu, 27 Sep 2012 08:05:32 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Cyrill Gorcunov CC: Alan Cox , Greg Kroah-Hartman , LKML , Pavel Emelyanov , Jiri Slaby Subject: Re: [RFC] tty: Add get- ioctls to fetch tty status References: <20120923010953.GA17663@kroah.com> <20120923064007.GA2994@moon> <34f6ba7b-2c50-492e-9267-52d328a8d37f@email.android.com> <20120924141441.GD16532@moon> <20120927140502.GB12552@moon> <20120927151447.2460ce44@pyramind.ukuu.org.uk> <20120927141425.GG6618@moon> <5064600D.1090506@zytor.com> <20120927142149.GH6618@moon> <50646620.4090708@zytor.com> <20120927144842.GI6618@moon> In-Reply-To: <20120927144842.GI6618@moon> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/27/2012 07:48 AM, Cyrill Gorcunov wrote: > On Thu, Sep 27, 2012 at 07:43:44AM -0700, H. Peter Anvin wrote: >>>> If you can't guarantee that ALL those processes are stopped and >>>> checkpointed/restarted, you have a huge problem. >>> >>> Well, sure inside our tool before doing checkpoint we stop all >>> tasks which are part of dumpee process tree. This unfortunatly >>> doesn't apply to these ioctl calls. Peter, any idea how to deal >>> with that? >> >> Sorry, no. I suspect you might be trying to do something that is >> impossible to do in a general fashion without application changes. > > I see. What if I wrap all this entries with CONFIG_CHECKPOINT_RESTORE > and say add some sysctl which would enable/disbale this ioctls. Then > it'll be up to user-space callers to make sure that data received is > valid and can be used? The problem is that I need to fetch this bits > somehow with minimal changes in kernel. > I don't see how that solves anything. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.