From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753741AbbAVIkr (ORCPT ); Thu, 22 Jan 2015 03:40:47 -0500 Received: from szxga01-in.huawei.com ([119.145.14.64]:31283 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753436AbbAVIkj (ORCPT ); Thu, 22 Jan 2015 03:40:39 -0500 Message-ID: <54C0B735.7070106@huawei.com> Date: Thu, 22 Jan 2015 16:39:17 +0800 From: Li Bin User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Josh Poimboeuf CC: Jiri Kosina , Seth Jennings , Vojtech Pavlik , Jiri Slaby , Miroslav Benes , , , , , , Subject: Re: [PATCH 2/2] livepatch: disable/enable_patch manners for interdependent patches References: <1421831262-27869-1-git-send-email-huawei.libin@huawei.com> <1421831262-27869-3-git-send-email-huawei.libin@huawei.com> <54C04775.1070908@huawei.com> <20150122035126.GB12927@treble.redhat.com> In-Reply-To: <20150122035126.GB12927@treble.redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.181] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/1/22 11:51, Josh Poimboeuf wrote: > On Thu, Jan 22, 2015 at 08:42:29AM +0800, Li Bin wrote: >> On 2015/1/21 22:08, Jiri Kosina wrote: >>> On Wed, 21 Jan 2015, Li Bin wrote: >>> By this you limit the definition of the patch inter-dependency to just >>> symbols. But that's not the only way how patches can depend on it other -- >>> the dependency can be semantical. >> >> Yes, I agree with you. But I think the other dependencies such as semantical >> dependency should be judged by the user, like reverting a patch from git repository. >> Right? > > But with live patching, there are two users: the patch creator (who > creates the patch module) and the end user (who loads it on their > system). > > We can assume the patch creator knows what he's doing, but the end user > doesn't always know or care about low level details like patch > dependencies. The easiest and safest way to protect the end user is the > current approach, which assumes that each patch depends on all > previously applied patches. But then, the feature that disable patch dynamically is useless. For example, if user find a bug be introduced by the last patch and disable it directly, the new patch is no longer allowed from now unless enable the old patch firstly but there is a risk window by this way. >