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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id a186sm3157627pgc.70.2022.02.15.10.17.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Feb 2022 10:17:41 -0800 (PST) Date: Tue, 15 Feb 2022 10:17:40 -0800 From: Kees Cook To: "Gustavo A. R. Silva" Cc: GR-QLogic-Storage-Upstream@marvell.com, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, linux-crypto@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, netdev@vger.kernel.org, linux-omap@vger.kernel.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, mpi3mr-linuxdrv.pdl@broadcom.com, linux-staging@lists.linux.dev, linux-rpi-kernel@lists.infradead.org, sparmaintainer@unisys.com, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-ext4@vger.kernel.org, linux-acpi@vger.kernel.org, devel@acpica.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, greybus-dev@lists.linaro.org, linux-i3c@lists.infradead.org, linux-rdma@vger.kernel.org, linux-bluetooth@vger.kernel.org, alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] treewide: Replace zero-length arrays with flexible-array members Message-ID: <202202151016.C0471D6E@keescook> References: <20220215174743.GA878920@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220215174743.GA878920@embeddedor> X-Rspamd-Queue-Id: 28356100003 X-Rspam-User: Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=BbY3zUMb; spf=pass (imf05.hostedemail.com: domain of keescook@chromium.org designates 209.85.216.44 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (policy=none) header.from=chromium.org X-Stat-Signature: 67ub5f9kkezaj3chx4cx1gsdbwanj4pm X-Rspamd-Server: rspam03 X-HE-Tag: 1644949062-275272 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.009098, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Feb 15, 2022 at 11:47:43AM -0600, Gustavo A. R. Silva wrote: > There is a regular need in the kernel to provide a way to declare > having a dynamically sized set of trailing elements in a structure. > Kernel code should always use =E2=80=9Cflexible array members=E2=80=9D[= 1] for these > cases. The older style of one-element or zero-length arrays should > no longer be used[2]. >=20 > This code was transformed with the help of Coccinelle: > (next-20220214$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file sc= ript.cocci --include-headers --dir . > output.patch) >=20 > @@ > identifier S, member, array; > type T1, T2; > @@ >=20 > struct S { > ... > T1 member; > T2 array[ > - 0 > ]; > }; These all look trivially correct to me. Only two didn't have the end of the struct visible in the patch, and checking those showed them to be trailing members as well, so: Reviewed-by: Kees Cook --=20 Kees Cook