From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from omta40.uswest2.a.cloudfilter.net (omta40.uswest2.a.cloudfilter.net [35.89.44.39]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6E6C1353F4 for ; Wed, 6 Mar 2024 15:42:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=35.89.44.39 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709739774; cv=none; b=gKGpeXIZtXIJ0pcO3QsLAXE6ko51VGZFgLiQRgM9EwXhXYdBHyJ+EN7ItIfJsI2Wdjnm4wU8UEbLfOh5aj2yFig0Y7y8tYc/0pGO+IoloPdw6wemTJ7a3BLpqfIw03YbzHNFo6Uj22zURRE0QL6wNCsaaON/Jq+rJW8zX6xOerY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709739774; c=relaxed/simple; bh=L6NtDTi6IxuJr2HEz9+NlQdI/czBfiDG2fLUsEkz3Ws=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=VhCBrQr6xW9dXMz2fes482byFT+yoO1QuWuCNlJImLI1JKTrBYTllB8FhGfiiA/nb8IUiY2OE8Iu0Q313vdW3n1J/7DnK/ptd/JXZXLL7wOSIR97JABflI/99tQ3gPs/BqiM2pzKowXuyZVjBhjCxFaob6Tj/S4iyrEQfqzPYOk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=embeddedor.com; spf=pass smtp.mailfrom=embeddedor.com; dkim=pass (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b=po9PMpUb; arc=none smtp.client-ip=35.89.44.39 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=embeddedor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="po9PMpUb" Received: from eig-obgw-5007a.ext.cloudfilter.net ([10.0.29.141]) by cmsmtp with ESMTPS id hsGJrdNMMPM1hhtPwrQVlW; Wed, 06 Mar 2024 15:42:52 +0000 Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with ESMTPS id htPvrsQdWwM25htPwr7Vsj; Wed, 06 Mar 2024 15:42:52 +0000 X-Authority-Analysis: v=2.4 cv=ZP7Rm27b c=1 sm=1 tr=0 ts=65e88efc a=1YbLdUo/zbTtOZ3uB5T3HA==:117 a=VhncohosazJxI00KdYJ/5A==:17 a=IkcTkHD0fZMA:10 a=K6JAEmCyrfEA:10 a=wYkD_t78qR0A:10 a=cm27Pg_UAAAA:8 a=VwQbUJbxAAAA:8 a=6VED1VvVYjxIH-aiRFQA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=xmb-EsYY8bH0VWELuYED:22 a=AjGcO6oz07-iQ99wixmX:22 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=lmpKyOPFUzJ+LEJ4c5jaCXB0zx3UWJMtP0zgRHJSV20=; b=po9PMpUbR2G7GPleV01kCDx0FG 4KF3gs0ABvVJ7iyALWRBsG0EncGjNCUrVEvX5FdPlWlGFktr5FO3ylw206TI6DwTlml15J8xfb6ei 5f/9XzMPQnre/GH874iMFN+/OTBe7toLCN04YHRHotRE7RNZOuyZFTKGaCRel9CQrdwMg8KGKrPMf cQ0Sy/HcmGLDFNx+zZQ1rD+lStj7Ezecvdmg4ytztNR1v5rR9Ub8ewLVxYr7J8uL4YuFHG7n2z9gQ lvLWxCb01Vu87+N6MjBTJOYlHecKC2Lc5NBrP601G1NA2WgpdGID5bu1W30My5F/loENuEi6L4Asw id3pXPzA==; Received: from [201.172.172.225] (port=37704 helo=[192.168.15.10]) by gator4166.hostgator.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96.2) (envelope-from ) id 1rhtPv-000nwp-0p; Wed, 06 Mar 2024 09:42:51 -0600 Message-ID: <34889a1a-4c8f-4c4d-865a-f947569f8d9c@embeddedor.com> Date: Wed, 6 Mar 2024 09:42:50 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH][next] fsnotify: Avoid -Wflex-array-member-not-at-end warning Content-Language: en-US To: Amir Goldstein , Kees Cook Cc: "Gustavo A. R. Silva" , Jan Kara , Alexander Viro , Christian Brauner , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org References: <202403051548.045B16BF@keescook> From: "Gustavo A. R. Silva" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 201.172.172.225 X-Source-L: No X-Exim-ID: 1rhtPv-000nwp-0p X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: ([192.168.15.10]) [201.172.172.225]:37704 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 11 X-Org: HG=hgshared;ORG=hostgator; X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-CMAE-Envelope: MS4xfFtxVcf9kTbbstU7V2B4omcDsrF2sFJ2rMc9OC/8fMaFg4lQBrsVFsRDDngeu2hPfFNmagMajYrSA3f1MhQCBowG3a8+2TTTiWTVcpZ8UKXOqvYJTfBn zI9IDV0TEl3CU1arB2YfrlE5Dj0YZN2F0IdZNjZ9+H7EgKXeHYdLEid6rD6QQeLtlNWbIlqKblzhYTXUbFSOQSdV5RckOU8O/Z7gvvwFfVEX+DceGs3XYozQ On 3/6/24 01:36, Amir Goldstein wrote: > On Wed, Mar 6, 2024 at 1:52 AM Kees Cook wrote: >> >> On Tue, Mar 05, 2024 at 04:18:46PM -0600, Gustavo A. R. Silva wrote: >>> -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting >>> ready to enable it globally. >>> >>> There is currently a local structure `f` that is using a flexible >>> `struct file_handle` as header for an on-stack place-holder for the >>> flexible-array member `unsigned char f_handle[];`. >>> >>> struct { >>> struct file_handle handle; >>> u8 pad[MAX_HANDLE_SZ]; >>> } f; >> >> This code pattern is "put a flex array struct on the stack", but we have >> a macro for this now: >> >> DEFINE_FLEX(struct file_handle, handle, f_handle, MAX_HANDLE_SZ); >> >> And you can even include the initializer: >> >> _DEFINE_FLEX(struct file_handle, handle, f_handle, MAX_HANDLE_SZ, >> = { .handle_bytes = MAX_HANDLE_SZ }); >> > > Indeed that looks much nicer. Yeah, I'll probably wait for this to land before I send a v2: https://lore.kernel.org/linux-hardening/20240306010746.work.678-kees@kernel.org/ Thanks -- Gustavo