From patchwork Tue Feb 11 23:42:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 11377241 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CBB1D139A for ; Wed, 12 Feb 2020 00:03:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA43F20724 for ; Wed, 12 Feb 2020 00:03:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="J8DOEd5+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727979AbgBLADY (ORCPT ); Tue, 11 Feb 2020 19:03:24 -0500 Received: from gateway32.websitewelcome.com ([192.185.145.102]:24747 "EHLO gateway32.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727956AbgBLADX (ORCPT ); Tue, 11 Feb 2020 19:03:23 -0500 X-Greylist: delayed 1397 seconds by postgrey-1.27 at vger.kernel.org; Tue, 11 Feb 2020 19:03:23 EST Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway32.websitewelcome.com (Postfix) with ESMTP id E5EBE645B9 for ; Tue, 11 Feb 2020 17:40:05 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 1f8PjKfx9vBMd1f8PjeGTV; Tue, 11 Feb 2020 17:40:05 -0600 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Type:MIME-Version:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=826huAG5ON0O/lfMhDpKUhNKj75IXOzCCcEnxbYam4I=; b=J8DOEd5+Zj56yKjv9GxEr/9liR UxDb0yEozNCQtzTvTsjQ/6Nzv7jY4PMpcocRI1RLtNWUcZdEfadqZcNsYKNTtGPlWbh64mO46Z5fc HSmPuT+YqB+oY4cyV7ADajR1EKG1xmts+TOzRBPHNuirE+T2pnefl+SZTFNOL+SpV38VFZwrD4Cq3 VjGWpDTya1CN0iqllnWMJvE5g8YzTR4zl27fE40CPAQkpP23qk7tJJeHxOyNnENQVBp9r55FJHO+v xzmsjHdTZIcGqgGm7cCr6eCyBBuFzxLr5fYeImmEC0zCP1VQv4S/dLs/x56PEYF1/HqKLtx7U3A+3 4nZJpRdA==; Received: from [200.68.140.36] (port=31131 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j1f8O-003iJb-Fb; Tue, 11 Feb 2020 17:40:04 -0600 Date: Tue, 11 Feb 2020 17:42:37 -0600 From: "Gustavo A. R. Silva" To: Jean Delvare , Guenter Roeck Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] hwmon: (ibmaem) Replace zero-length array with flexible-array member Message-ID: <20200211234237.GA26971@embeddedor> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) 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: 200.68.140.36 X-Source-L: No X-Exim-ID: 1j1f8O-003iJb-Fb X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [200.68.140.36]:31131 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 51 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva --- drivers/hwmon/ibmaem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/ibmaem.c b/drivers/hwmon/ibmaem.c index db63c1295cb2..fb052c2d9c34 100644 --- a/drivers/hwmon/ibmaem.c +++ b/drivers/hwmon/ibmaem.c @@ -232,7 +232,7 @@ struct aem_read_sensor_req { struct aem_read_sensor_resp { struct aem_iana_id id; - u8 bytes[0]; + u8 bytes[]; } __packed; /* Data structures to talk to the IPMI layer */