From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f49.google.com (mail-pj1-f49.google.com [209.85.216.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C1A11842 for ; Tue, 15 Feb 2022 18:17:42 +0000 (UTC) Received: by mail-pj1-f49.google.com with SMTP id n19-20020a17090ade9300b001b9892a7bf9so3832916pjv.5 for ; Tue, 15 Feb 2022 10:17:42 -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:content-transfer-encoding:in-reply-to; bh=rU/cr+2YS83r8ZzfG0ihHyfke5lY7dzNO33vRqwTRo0=; b=BbY3zUMbpsKVLuD6QiFaFpnxej58wpxQPVVGisDcf+K+2coTsFmZNXGoWqBeKoLb1x 3ZptFg7el6LpqeSuHR1QjwuSCHfpkEX/T+XcjAHpaQzkvx2kHT7d0+kYGoaayuMfQhPV CAs5kcpK7DDzn/NDlTFukbq1xe316LjUYcWLM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=rU/cr+2YS83r8ZzfG0ihHyfke5lY7dzNO33vRqwTRo0=; b=IWXgQ9BBP5QiGnPFgP4zVkXqHUXx7uMVNt6qxkXjgmdx3pIgiGpz3iE53AvT3JbwQ1 tCpoaNPexZ7YbhRqkvVHAV/wR9HfQrwEOeB69EOg1pzICGwqD8307sKBnE25Z29kVhfX u12nooRZGvxrIQ64oMVQDNpfGoJcJHviM3YbL0BtMBd8Mk3CcLHcp043v13E1QXwbb1O nQcUYajFKk68NdRRwpbFcimyYlO23zJBI4CGz4mx3EKlvE4XLLL9J9Flnv14GiS/bQoU zgYptwGiZn2Sl/fzs7F4JThpFIgGcw+igudFcMOWahpEibzdLXOk12qy3CoYtzbAVrKe sMoQ== X-Gm-Message-State: AOAM532saq4qoFgpd8Kdh8mgH0zWTtPoEYLaXHnX2GKOfSBNJ115pIxD eoKyVnpyHDnUKKTM/ThDTyptZw== X-Google-Smtp-Source: ABdhPJwjJJkj0fC2gO+FdGjnaisWCk9FKkCf0qazg7PUuY4rrjoW+egyeLOWB+yCEr/MI5qa+9+dbA== X-Received: by 2002:a17:902:eb8f:: with SMTP id q15mr235036plg.67.1644949062021; Tue, 15 Feb 2022 10:17:42 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [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> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220215174743.GA878920@embeddedor> 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 “flexible array members”[1] for these > cases. The older style of one-element or zero-length arrays should > no longer be used[2]. > > This code was transformed with the help of Coccinelle: > (next-20220214$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch) > > @@ > identifier S, member, array; > type T1, T2; > @@ > > 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 -- Kees Cook