From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90863C04EB8 for ; Thu, 6 Dec 2018 14:36:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5ABCD20672 for ; Thu, 6 Dec 2018 14:36:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5ABCD20672 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729245AbeLFOgR (ORCPT ); Thu, 6 Dec 2018 09:36:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47944 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728448AbeLFOgR (ORCPT ); Thu, 6 Dec 2018 09:36:17 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 313D7300250A; Thu, 6 Dec 2018 14:36:17 +0000 (UTC) Received: from jlaw-desktop.bos.csb (dhcp-17-208.bos.redhat.com [10.18.17.208]) by smtp.corp.redhat.com (Postfix) with ESMTP id 45E5F2E053; Thu, 6 Dec 2018 14:36:07 +0000 (UTC) Subject: Re: [PATCH v14 05/11] livepatch: Simplify API by removing registration step To: Petr Mladek , Miroslav Benes Cc: Jiri Kosina , Josh Poimboeuf , Jason Baron , Evgenii Shatokhin , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org References: <20181129094431.7801-1-pmladek@suse.com> <20181129094431.7801-6-pmladek@suse.com> <20181205193253.mhlqj37r4o6ukkhp@redhat.com> <20181206082814.uyzjw2q4avknhswd@pathway.suse.cz> <20181206101423.3nps4tgyg45jwofj@pathway.suse.cz> From: Joe Lawrence Organization: Red Hat Message-ID: <22937554-9c7c-ed9a-0f8d-70aa6e81b25d@redhat.com> Date: Thu, 6 Dec 2018 09:36:06 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20181206101423.3nps4tgyg45jwofj@pathway.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Thu, 06 Dec 2018 14:36:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/06/2018 05:14 AM, Petr Mladek wrote: > On Thu 2018-12-06 10:23:40, Miroslav Benes wrote: >> On Thu, 6 Dec 2018, Petr Mladek wrote: >> >>> On Wed 2018-12-05 14:32:53, Joe Lawrence wrote: >>>>> diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c >>>>> index 972520144713..e01dfa3b58d2 100644 >>>>> --- a/kernel/livepatch/core.c >>>>> +++ b/kernel/livepatch/core.c >>>>> @@ -45,7 +45,7 @@ >>>>> */ >>>>> DEFINE_MUTEX(klp_mutex); >>>>> >>>>> -/* Registered patches */ >>>>> +/* Actively used patches. */ >>>>> LIST_HEAD(klp_patches); >>>> >>>> By itself, this comment makes me wonder if there are un-active and/or >>>> un-used patches that I need to worry about. After this patchset, >>>> klp_patches will include patches that have been enabled and those that >>>> have been replaced, but the replacement transition is still in progress. >>>> >>>> If that sounds accurate, how about adding to the comment: >>>> >>>> /* Actively used patches: enabled or replaced and awaiting transition */ >>> >>> The replaced patches are not in the list. This is why I used the word >>> "actively". >> After writing out my suggestion I realized that's why you chose "actively" and almost erased my comment. I think the extra text would help a fresh reader of the code, so ... >> The replaced patches are removed in klp_discard_replaced_patches(), which >> is called from klp_complete_transition(). Joe is right. The patches are in >> the list if a transition is still in progress. > > These are patches that are being replaced. The replaced (after the > transition finishes) are not in the list. > > By other word, Joe's text could be understand that replaced patches > will never get removed from the list. > > So, is the text below acceptable? > > /* > * Actively used patches: enabled or in transition. Note that replaced > * or disabled patches are not listed even though the related kernel > * module still can be loaded. > */ Yes this works and is more accurate than my original suggestion. Thanks, -- Joe