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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 E4EECC56202 for ; Mon, 23 Nov 2020 13:03:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 74FE420782 for ; Mon, 23 Nov 2020 13:03:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="huMDpxd3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 74FE420782 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CAD436B0072; Mon, 23 Nov 2020 08:03:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C35C16B0073; Mon, 23 Nov 2020 08:03:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD6A56B0074; Mon, 23 Nov 2020 08:03:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0138.hostedemail.com [216.40.44.138]) by kanga.kvack.org (Postfix) with ESMTP id 7AED26B0072 for ; Mon, 23 Nov 2020 08:03:44 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 127101EF1 for ; Mon, 23 Nov 2020 13:03:44 +0000 (UTC) X-FDA: 77515699968.23.cat48_1d0ad6227365 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id D395337609 for ; Mon, 23 Nov 2020 13:03:43 +0000 (UTC) X-HE-Tag: cat48_1d0ad6227365 X-Filterd-Recvd-Size: 6217 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Mon, 23 Nov 2020 13:03:42 +0000 (UTC) Received: from embeddedor (187-162-31-110.static.axtel.net [187.162.31.110]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 191D120758; Mon, 23 Nov 2020 13:03:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606136621; bh=J/TET3MqSRKQBkZDLmw3offBuTNq8xblR6VPj5c7KTQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=huMDpxd34lY8zl81VJt6WrkzA8VbZ3WZKfCc+01YUsnQkEm+dvBfrNL343ZTscxgS 4cn7RRAIuR/6lyK6TO0qxACy3TNrSBuTodAx+s4Q2YpvApK9inZpqsbsSdtJmbV9Zx YwwBYqtSxUH9kHvWkiEz2t98c4vnYVnAJ6qqQTEg= Date: Mon, 23 Nov 2020 07:03:48 -0600 From: "Gustavo A. R. Silva" To: James Bottomley Cc: Joe Perches , Kees Cook , 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: <20201123130348.GA3119@embeddedor> References: <20201120105344.4345c14e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011201129.B13FDB3C@keescook> <20201120115142.292999b2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011220816.8B6591A@keescook> <9b57fd4914b46f38d54087d75e072d6e947cb56d.camel@HansenPartnership.com> <0147972a72bc13f3629de8a32dee6f1f308994b5.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Nov 22, 2020 at 11:53:55AM -0800, James Bottomley wrote: > On Sun, 2020-11-22 at 11:22 -0800, Joe Perches wrote: > > On Sun, 2020-11-22 at 11:12 -0800, James Bottomley wrote: > > > On Sun, 2020-11-22 at 10:25 -0800, Joe Perches wrote: > > > > On Sun, 2020-11-22 at 10:21 -0800, James Bottomley wrote: > > > > > Please tell me our reward for all this effort isn't a single > > > > > missing error print. > > > > > > > > There were quite literally dozens of logical defects found > > > > by the fallthrough additions. Very few were logging only. > > > > > > So can you give us the best examples (or indeed all of them if > > > someone is keeping score)? hopefully this isn't a US election > > > situation ... > > > > Gustavo? Are you running for congress now? > > > > https://lwn.net/Articles/794944/ > > That's 21 reported fixes of which about 50% seem to produce no change > in code behaviour at all, a quarter seem to have no user visible effect > with the remaining quarter producing unexpected errors on obscure > configuration parameters, which is why no-one really noticed them > before. The really important point here is the number of bugs this has prevented and will prevent in the future. See an example of this, below: https://lore.kernel.org/linux-iio/20190813135802.GB27392@kroah.com/ This work is still relevant, even if the total number of issues/bugs we find in the process is zero (which is not the case). "The sucky thing about doing hard work to deploy hardening is that the result is totally invisible by definition (things not happening) [..]" - Dmitry Vyukov Thanks -- Gustavo