Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753235AbbDNASD (ORCPT ); Mon, 13 Apr 2015 20:18:03 -0400 Received: from blu004-omc4s32.hotmail.com ([65.55.111.171]:57244 "EHLO BLU004-OMC4S32.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752003AbbDNAR6 (ORCPT ); Mon, 13 Apr 2015 20:17:58 -0400 X-TMN: [tJe8/s7TQ03jET0UbYnYrVM/bdD4b5/7] X-Originating-Email: [minfei.huang@hotmail.com] Message-ID: Date: Tue, 14 Apr 2015 08:17:52 +0800 From: Minfei Huang To: Josh Poimboeuf CC: Petr Mladek , sjenning@redhat.com, jkosina@suse.cz, vojtech@suse.cz, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] livepatch: Add a new function to verify the address and name match for extra module References: <1428844554-4015-1-git-send-email-minfei.huang@hotmail.com> <20150413083725.GA16088@pathway.suse.cz> <20150413094121.GD16088@pathway.suse.cz> <20150413102240.GE16088@pathway.suse.cz> <20150413225849.GC4412@treble.hsd1.ky.comcast.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20150413225849.GC4412@treble.hsd1.ky.comcast.net> User-Agent: Mutt/1.5.23 (2014-03-12) X-OriginalArrivalTime: 14 Apr 2015 00:17:56.0333 (UTC) FILETIME=[74D121D0:01D07648] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1579 Lines: 45 On 04/13/15 at 05:58P, Josh Poimboeuf wrote: > On Mon, Apr 13, 2015 at 06:37:10PM +0800, Minfei Huang wrote: > > For my patches, I think it is used by the persion which will compose the > > patch individually, not for the manufactor. > > > > Yes, Verifying extra function address is more useless in general, due to > > the changable address on different system. > > > > IMO, we shall do our best to make livepatch more robust. > > IIUC, to use this, you'd have to load the module first, manually look up > the module function's address, and _then_ build the patch for the > running system. And the resulting patch wouldn't work on other systems. > > Do you have concrete plans to use it this way? > > Just trying to understand if this is needed for a real world usage > scenario. For some companies(like cloud computing company), they will compose their own module to improve the performance. Once there is some bug for the own module, they cannt restart to reload the fixed-module. So it seems that livepatch is the best way to fix this issue. Before livepatch being integrated in kernel, we usually use ksplice to patch the patch. What the above scenario I met is in my previous work. For now, livepatch cannt patch the patch for extra module, once the function name is larger than 127. Thanks Minfei > > -- > Josh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/