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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22853CDB47E for ; Wed, 11 Oct 2023 22:42:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376534AbjJKWmu (ORCPT ); Wed, 11 Oct 2023 18:42:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235211AbjJKWms (ORCPT ); Wed, 11 Oct 2023 18:42:48 -0400 Received: from mail-ed1-x52b.google.com (mail-ed1-x52b.google.com [IPv6:2a00:1450:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E92389D for ; Wed, 11 Oct 2023 15:42:46 -0700 (PDT) Received: by mail-ed1-x52b.google.com with SMTP id 4fb4d7f45d1cf-5333fb34be3so695862a12.1 for ; Wed, 11 Oct 2023 15:42:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697064165; x=1697668965; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=/yrWMHnU++xrRqYHbtcx/jI9yDnw9HSAqWIYV1wwM4s=; b=fvGP5m6I5GUDE+yqS0XZnaI6tq4FdXF/rNbu6F5SPfatZPGZ8KUlzEaSv94bs0LAoR EyfOeWDB8RVQj4OfdlLJMqJtzoe+/VWiMwS5/gEixZi8ne0yoRiaphpRooDbfqwljxuq euObnl7lxJeZxU2eZptWieE9zLv24wmyzx2qOyqrSZyAsWGyyD3TPsIK5tFkJ/C/JBtr mRpCa7oLh4KQKXdvMd8sTfeoLD7asDzG9NUD/fK8zh31rsmo9g3NRl1JHry29Y+IzfzP xJ42YCRrIK9ksGoUSK++hu8pFrQVA6ZYaoBRS/a5fGVeGSuLV2VVmPgWHjUmuTG4LJIC Gt2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697064165; x=1697668965; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/yrWMHnU++xrRqYHbtcx/jI9yDnw9HSAqWIYV1wwM4s=; b=FDb9rJgztv+SR8aOdKGylBi/F+tDLMaNQyz9OM+TsVcBSWWn7HGRxdNe8NtD7Q1/Lm qLhV6xhYJrinZiyYjQ93/8ezKIz6sNx3ipW+kczEfiDMRECpywU3YnAlPDlwY7DAmhSr oAzhxuPtRJ9mZf7B3XUb/Mpoja8OBTWho9bZuTNoTPX7oSWS0w8wenQ8PFywNKsDk1XA SeZuy3BTlr0K2sgj2S9cc2AWSpFJKtbq8zDumiztsVGJCf9Y82abPCovVWUkvsfo9WXn Q2HerJcN+8aIbcsUksR2CeVw/mAsZ8GtSm5V7jLcniyb9LQlQ8zYVaGib0yKWzblHrVk Akhw== X-Gm-Message-State: AOJu0YyGZMZUvyMC1Zif2qsEtapS7tV9/oXyebZCN5BP6Uu2vpZGOt1j QvqsLjuUNYWzvLk8gCKUz38= X-Google-Smtp-Source: AGHT+IE+wKu7paim2Fer5C0M2i7Oxkg46ZEcFshD9/tGoguQTUrempImFlqZeALERKQproe4B5Zw/A== X-Received: by 2002:aa7:c549:0:b0:525:6e47:10f6 with SMTP id s9-20020aa7c549000000b005256e4710f6mr20151639edr.22.1697064165123; Wed, 11 Oct 2023 15:42:45 -0700 (PDT) Received: from gmail.com (1F2EF405.nat.pool.telekom.hu. [31.46.244.5]) by smtp.gmail.com with ESMTPSA id ba10-20020a0564021aca00b005346bebc2a5sm9336498edb.86.2023.10.11.15.42.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Oct 2023 15:42:44 -0700 (PDT) Sender: Ingo Molnar Date: Thu, 12 Oct 2023 00:42:42 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Josh Poimboeuf , Borislav Petkov , David Kaplan , x86@kernel.org, luto@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] Revert "x86/retpoline: Remove .text..__x86.return_thunk section" Message-ID: References: <20231010171020.462211-1-david.kaplan@amd.com> <20231010171020.462211-2-david.kaplan@amd.com> <20231010174833.GG14330@noisy.programming.kicks-ass.net> <20231010195721.p5pb273kevg7ydxz@treble> <20231010200429.GIZSWuTWSUM9aId7a6@fat_crate.local> <20231010201912.7pjksbparssqu34k@treble> <20231010212254.ypk2wdogno55shit@treble> <20231011074142.GK14330@noisy.programming.kicks-ass.net> <20231011162843.grv6kixw4ides6uw@treble> <20231011223513.GH6307@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231011223513.GH6307@noisy.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > I don't care too deeply, I can't make up my mind either way. But perhaps > keeping the section is easier on all the backports, it's easy to forget a > tiny objtool patch like this. If the objtool fix has a Fixes tag that points to one of the major mitigation commits, then it won't be forgotten. Arguably the new objtool is more robust against what could happen, so that patch is not going away - and with that patch mainline doesn't have to keep the (now ...) pointless section. Maybe change the commit order around: first add the objtool fix, then remove the section, pointing back to the objtool SHA1 in the very next commit, explaining that the objtool fix enables this change. That makes it all backporting-proof as well. Thanks, Ingo