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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D3119C83012 for ; Tue, 24 Nov 2020 21:33:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B2CF20866 for ; Tue, 24 Nov 2020 21:33:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="lzAwh4po" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732583AbgKXVc5 (ORCPT ); Tue, 24 Nov 2020 16:32:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732577AbgKXVct (ORCPT ); Tue, 24 Nov 2020 16:32:49 -0500 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0DCEC09424B for ; Tue, 24 Nov 2020 13:32:47 -0800 (PST) Received: by mail-pf1-x442.google.com with SMTP id s21so266761pfu.13 for ; Tue, 24 Nov 2020 13:32:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=nUebvx46WK355IC8BSYKhA86maU/C5TyOra9y/oS07E=; b=lzAwh4po+9zegkg/2K9x7CHiUUthvj2PFJyxHwt1QdcZQIdrGCSiE3JgzWuDiv+VMN KwBJ/6n/jsAIvSMb6eOJqvl2BVv6D2OMXP8giSKXaaH9JwLNdR2oULKAXe3g8bDVfAub 65Ll+320/JpDsvMBOWCFVSOrRLSDK1WOgK6ns= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=nUebvx46WK355IC8BSYKhA86maU/C5TyOra9y/oS07E=; b=TI+UN556J44UKltSjK2qvfxSX8GrpD7O8T7hi/dPTlFSI9EST7knRgISeeP6qjknxf a9IXc9eB02vf9nV3wVgnBKoaeG7FG45MryVRY2rRNEFCR9zsYTVWb+id7X6q3yC90zMM ERdAJSULz+2vSDkhiyZBe1/0Af2zHFY1Y5RMNn+Ymo52NSNG4whn9jzJAyHGYxEFLWhU 2npCq3cC0TKSvrFeLTwah8dlERPES63Xhih76TYEbOzQwYDyTKgMZIFlNv8PUh2jSomh YSGOnOxL49GorX/em6bvcyooa6VMianarY/cz6ySo22REK4y1txch1RBCjpNmLyIzfGM wkAg== X-Gm-Message-State: AOAM530GzO8hV6Uh+UJjuTTw1uUt++HfGPzfHjhc6C2NI1M/+zXyBxqC 8BNco8dCHOxLckkRa8kocA8CDA== X-Google-Smtp-Source: ABdhPJyp86bHnh+pX/bbtyJvtymIhKFSWtRW4h5d/m2XI4eSElpEXSRnILd/bhh2ok8eYrLt5J5YAQ== X-Received: by 2002:a17:90a:e2d4:: with SMTP id fr20mr212344pjb.202.1606253566770; Tue, 24 Nov 2020 13:32:46 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id k6sm5489pfd.169.2020.11.24.13.32.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Nov 2020 13:32:45 -0800 (PST) Date: Tue, 24 Nov 2020 13:32:44 -0800 From: Kees Cook To: James Bottomley Cc: "Gustavo A. R. Silva" , Joe Perches , Jakub Kicinski , alsa-devel@alsa-project.org, linux-atm-general@lists.sourceforge.net, reiserfs-devel@vger.kernel.org, linux-iio@vger.kernel.org, linux-wireless@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Nathan Chancellor , linux-ide@vger.kernel.org, dm-devel@redhat.com, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, GR-everest-linux-l2@marvell.com, wcn36xx@lists.infradead.org, samba-technical@lists.samba.org, linux-i3c@lists.infradead.org, linux1394-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, usb-storage@lists.one-eyed-alien.net, drbd-dev@lists.linbit.com, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, rds-devel@oss.oracle.com, Nick Desaulniers , linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, oss-drivers@netronome.com, bridge@lists.linux-foundation.org, linux-security-module@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-stm32@st-md-mailman.stormreply.com, cluster-devel@redhat.com, linux-acpi@vger.kernel.org, coreteam@netfilter.org, intel-wired-lan@lists.osuosl.org, linux-input@vger.kernel.org, Miguel Ojeda , tipc-discussion@lists.sourceforge.net, linux-ext4@vger.kernel.org, linux-media@vger.kernel.org, linux-watchdog@vger.kernel.org, selinux@vger.kernel.org, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-geode@lists.infradead.org, linux-can@vger.kernel.org, linux-block@vger.kernel.org, linux-gpio@vger.kernel.org, op-tee@lists.trustedfirmware.org, linux-mediatek@lists.infradead.org, xen-devel@lists.xenproject.org, nouveau@lists.freedesktop.org, linux-hams@vger.kernel.org, ceph-devel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, x86@kernel.org, linux-nfs@vger.kernel.org, GR-Linux-NIC-Dev@marvell.com, linux-mm@kvack.org, netdev@vger.kernel.org, linux-decnet-user@lists.sourceforge.net, linux-mmc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-sctp@vger.kernel.org, linux-usb@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-crypto@vger.kernel.org, patches@opensource.cirrus.com, linux-integrity@vger.kernel.org, target-devel@vger.kernel.org, linux-hardening@vger.kernel.org, Jonathan Cameron , Greg KH Subject: Re: [Intel-wired-lan] [PATCH 000/141] Fix fall-through warnings for Clang Message-ID: <202011241327.BB28F12F6@keescook> References: <202011201129.B13FDB3C@keescook> <20201120115142.292999b2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011220816.8B6591A@keescook> <9b57fd4914b46f38d54087d75e072d6e947cb56d.camel@HansenPartnership.com> <0147972a72bc13f3629de8a32dee6f1f308994b5.camel@HansenPartnership.com> <20201123130348.GA3119@embeddedor> <8f5611bb015e044fa1c0a48147293923c2d904e4.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8f5611bb015e044fa1c0a48147293923c2d904e4.camel@HansenPartnership.com> Precedence: bulk List-ID: X-Mailing-List: target-devel@vger.kernel.org On Mon, Nov 23, 2020 at 08:31:30AM -0800, James Bottomley wrote: > Really, no ... something which produces no improvement has no value at > all ... we really shouldn't be wasting maintainer time with it because > it has a cost to merge. I'm not sure we understand where the balance > lies in value vs cost to merge but I am confident in the zero value > case. What? We can't measure how many future bugs aren't introduced because the kernel requires explicit case flow-control statements for all new code. We already enable -Wimplicit-fallthrough globally, so that's not the discussion. The issue is that Clang is (correctly) even more strict than GCC for this, so these are the remaining ones to fix for full Clang coverage too. People have spent more time debating this already than it would have taken to apply the patches. :) This is about robustness and language wrangling. It's a big code-base, and this is the price of our managing technical debt for permanent robustness improvements. (The numbers I ran from Gustavo's earlier patches were that about 10% of the places adjusted were identified as legitimate bugs being fixed. This final series may be lower, but there are still bugs being found from it -- we need to finish this and shut the door on it for good.) -- Kees Cook