From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 785AEC11D3D for ; Thu, 27 Feb 2020 18:35:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40DB9246B4 for ; Thu, 27 Feb 2020 18:35:01 +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="RddKp6yX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729718AbgB0SfA (ORCPT ); Thu, 27 Feb 2020 13:35:00 -0500 Received: from gateway34.websitewelcome.com ([192.185.148.196]:44933 "EHLO gateway34.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729280AbgB0Se7 (ORCPT ); Thu, 27 Feb 2020 13:34:59 -0500 Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway34.websitewelcome.com (Postfix) with ESMTP id A9D7F3E5A7 for ; Thu, 27 Feb 2020 12:34:58 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 7NzujZGuoSl8q7NzujDUn3; Thu, 27 Feb 2020 12:34:58 -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=bhPHK/N4A61h2syo2X1zezBye6MjYEOpxj4W5r7wBqY=; b=RddKp6yXbkYhCmwlzNx0Qcs63N XgKcp0ytO5RIJ8YbLV6LYBaQ989L68llzybq70zyj+kBG0Tv2IGAKL0d+0oY7nwAiu2c3Bl8XMtTC 82FjXN4/dgGQwoFgxBI9/sXlwm3Hv0UE40tTENGqxMfGIuOaAs3yWffnVN2F7v5O+gVnJSoR95FQz oiVF/4tlzzMWCtoY/+kAmPVQj9h1efYbcCTRYVqGReOOCjNmI+SQ8b5u89Ge/93MZTG6JKVdt+RZJ 9KgHCnGbMsWs1DwxG6I51EvexKUuXkam14x9YKlYPC+qtIQuBcF5vtXimZto/ICv+9gXCmIrYgOLl yPioBx3A==; Received: from [201.162.168.186] (port=21630 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j7Nzs-003vAP-Gq; Thu, 27 Feb 2020 12:34:56 -0600 Date: Thu, 27 Feb 2020 12:37:48 -0600 From: "Gustavo A. R. Silva" To: Geert Uytterhoeven Cc: linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] zorro: Replace zero-length array with flexible-array member Message-ID: <20200227183748.GA31018@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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: 201.162.168.186 X-Source-L: No X-Exim-ID: 1j7Nzs-003vAP-Gq X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.162.168.186]:21630 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 3 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] 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/zorro/zorro.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/zorro/zorro.c b/drivers/zorro/zorro.c index 8eeb84c239db..47c733817903 100644 --- a/drivers/zorro/zorro.c +++ b/drivers/zorro/zorro.c @@ -41,7 +41,7 @@ struct zorro_dev *zorro_autocon; struct zorro_bus { struct device dev; - struct zorro_dev devices[0]; + struct zorro_dev devices[]; }; -- 2.25.0