From patchwork Thu Feb 27 18:58:37 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: 207235 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 BC6B9C11D3D for ; Thu, 27 Feb 2020 18:55:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 948A0206E2 for ; Thu, 27 Feb 2020 18:55:50 +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="ge/31r8d" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729816AbgB0Szu (ORCPT ); Thu, 27 Feb 2020 13:55:50 -0500 Received: from gateway21.websitewelcome.com ([192.185.45.38]:32337 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729638AbgB0Szu (ORCPT ); Thu, 27 Feb 2020 13:55:50 -0500 Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway21.websitewelcome.com (Postfix) with ESMTP id 171C7400D73FF for ; Thu, 27 Feb 2020 12:55:49 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 7OK5jykRPvBMd7OK5juKNg; Thu, 27 Feb 2020 12:55:49 -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=oeJVRwr6+tzB7aIFz/Q1mFYLhzDIrqt7xOL5F5f6fNs=; b=ge/31r8dACB/Cl0FWauYBUzZ5m oc90GhNkdOQpJok8BkT5W0DXcA/RkRKPm0duOu833VwvCQrCrnR5FHSviGXMOGY3WNQHvAFnDGLiR Xvdof36uPbBsLQZIc3wfirz+avUAVe8QrPtK+KsV7qN5YQQA4ztkgzET3w8LSsoEJh/6J5aabJ+1Q pHMweR1dj7k/Oc9nfuX0MYvZhD9fw/htSuburtz/0m/6XlAQ3nRvPQJz2j+5j5dUnmbMbTpB6zsLX RaYNVsycnWn3sIHOtnboPzRPz/gg8kmw3XddeBa+pCK/feeKrIdUD9hJSWbMgQTE9KKnpqWsGOiCr dooFu8QQ==; Received: from [201.162.168.186] (port=4092 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j7OK1-0046LF-GX; Thu, 27 Feb 2020 12:55:46 -0600 Date: Thu, 27 Feb 2020 12:58:37 -0600 From: "Gustavo A. R. Silva" To: Linus Walleij , Barry Song Cc: linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] pinctrl: sirf/atlas7: Replace zero-length array with flexible-array member Message-ID: <20200227185837.GA4469@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: 201.162.168.186 X-Source-L: No X-Exim-ID: 1j7OK1-0046LF-GX X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.162.168.186]:4092 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 9 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@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/pinctrl/sirf/pinctrl-atlas7.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pinctrl/sirf/pinctrl-atlas7.c b/drivers/pinctrl/sirf/pinctrl-atlas7.c index b1a9611f46b3..50df9e084414 100644 --- a/drivers/pinctrl/sirf/pinctrl-atlas7.c +++ b/drivers/pinctrl/sirf/pinctrl-atlas7.c @@ -352,7 +352,7 @@ struct atlas7_gpio_chip { int nbank; raw_spinlock_t lock; struct gpio_chip chip; - struct atlas7_gpio_bank banks[0]; + struct atlas7_gpio_bank banks[]; }; /**