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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id j74sm15845pfd.43.2020.11.24.13.32.45 (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 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 In-Reply-To: <8f5611bb015e044fa1c0a48147293923c2d904e4.camel@HansenPartnership.com> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-loop: dm-devel@redhat.com X-Mailman-Approved-At: Wed, 25 Nov 2020 02:15:21 -0500 Cc: alsa-devel@alsa-project.org, bridge@lists.linux-foundation.org, target-devel@vger.kernel.org, Greg KH , linux-iio@vger.kernel.org, samba-technical@lists.samba.org, linux-mmc@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , linux-mm@kvack.org, 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, linux-i3c@lists.infradead.org, linux1394-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, rds-devel@oss.oracle.com, linux-scsi@vger.kernel.org, linux-acpi@vger.kernel.org, linux-rdma@vger.kernel.org, oss-drivers@netronome.com, linux-atm-general@lists.sourceforge.net, ceph-devel@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-stm32@st-md-mailman.stormreply.com, cluster-devel@redhat.com, usb-storage@lists.one-eyed-alien.net, coreteam@netfilter.org, intel-wired-lan@lists.osuosl.org, linux-input@vger.kernel.org, Miguel Ojeda , Jakub Kicinski , linux-ext4@vger.kernel.org, virtualization@lists.linux-foundation.org, netfilter-devel@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-sctp@vger.kernel.org, reiserfs-devel@vger.kernel.org, linux-geode@lists.infradead.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, drbd-dev@tron.linbit.com, linux-hams@vger.kernel.org, Nathan Chancellor , linux-can@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, Nick Desaulniers , linux-nfs@vger.kernel.org, GR-Linux-NIC-Dev@marvell.com, nouveau@lists.freedesktop.org, netdev@vger.kernel.org, linux-decnet-user@lists.sourceforge.net, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-security-module@vger.kernel.org, linux-usb@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-crypto@vger.kernel.org, Jonathan Cameron , patches@opensource.cirrus.com, Joe Perches , linux-integrity@vger.kernel.org, x86@kernel.org, linux-hardening@vger.kernel.org Subject: Re: [dm-devel] [Intel-wired-lan] [PATCH 000/141] Fix fall-through warnings for Clang X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel