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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 C137AECE58F for ; Tue, 15 Oct 2019 22:17:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8534E214AE for ; Tue, 15 Oct 2019 22:17:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726856AbfJOWRu (ORCPT ); Tue, 15 Oct 2019 18:17:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51926 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726747AbfJOWRu (ORCPT ); Tue, 15 Oct 2019 18:17:50 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 513AA51EE6; Tue, 15 Oct 2019 22:17:49 +0000 (UTC) Received: from [10.10.120.184] (ovpn-120-184.rdu2.redhat.com [10.10.120.184]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F3C096064B; Tue, 15 Oct 2019 22:17:44 +0000 (UTC) Subject: Re: [PATCH v3 5/6] x86/ftrace: Use text_poke() To: Jessica Yu Cc: Miroslav Benes , Peter Zijlstra , Steven Rostedt , x86@kernel.org, linux-kernel@vger.kernel.org, mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com, torvalds@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org, namit@vmware.com, hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org, jpoimboe@redhat.com, live-patching@vger.kernel.org References: <20191010092054.GR2311@hirez.programming.kicks-ass.net> <20191010091956.48fbcf42@gandalf.local.home> <20191010140513.GT2311@hirez.programming.kicks-ass.net> <20191010115449.22044b53@gandalf.local.home> <20191010172819.GS2328@hirez.programming.kicks-ass.net> <20191011125903.GN2359@hirez.programming.kicks-ass.net> <20191015130739.GA23565@linux-8ccs> <20191015135634.GK2328@hirez.programming.kicks-ass.net> <88bab814-ea24-ece9-2bc0-7a1e10a62f12@redhat.com> <20191015153120.GA21580@linux-8ccs> From: Joe Lawrence Message-ID: <7e9c7dd1-809e-f130-26a3-3d3328477437@redhat.com> Date: Tue, 15 Oct 2019 18:17:43 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <20191015153120.GA21580@linux-8ccs> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 15 Oct 2019 22:17:49 +0000 (UTC) Sender: live-patching-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On 10/15/19 11:31 AM, Jessica Yu wrote: > +++ Joe Lawrence [15/10/19 11:06 -0400]: >> On 10/15/19 10:13 AM, Miroslav Benes wrote: >>> Yes, it does. klp_module_coming() calls module_disable_ro() on all >>> patching modules which patch the coming module in order to call >>> apply_relocate_add(). New (patching) code for a module can be relocated >>> only when the relevant module is loaded. >> >> FWIW, would the LPC blue-sky2 model (ie, Steve's suggestion @ >> plumber's where livepatches only patch a single object and updates are >> kept on disk to handle coming module updates as they are loaded) >> eliminate those outstanding relocations and the need to perform this >> late permission flipping? > > I wasn't at Plumbers sadly, was this idea documented/talked about in > detail somewhere? (recording, slides, etherpad, etc?). What do you > mean by updates are kept on disk? Maybe someone can explain it more > in detail? :) > Livepatching folks -- I don't have the LPC summary link (etherpad?) that Jiri put together. Does someone have that handy for Jessica? Thanks, -- Joe