From patchwork Thu Feb 27 13:13:07 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: 11408595 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 375C8924 for ; Thu, 27 Feb 2020 13:10:29 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 143912469B for ; Thu, 27 Feb 2020 13:10:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="MVjff7IY"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="RyWYqttg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 143912469B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-i3c-bounces+linux-i3c=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Subject:To:From :Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=vdnWaD93fVFrouSTpYpvEOYBOgzrPlKvRsrIA5Tch4A=; b=MVjff7IYYYN59B AW0ORWj+FpQtYR9ZhbH0IFyl9JJJffoj1+2noTo+bxLfsByLvrZMxVz6EK2IISBDU7eznEBOr0xrG cHVWwhxJiB7Mm5L1eE/oLiyfus3nh825VpSfFSuFk4KXq8uuDfBHPEUpXCDlwOiKZEh5b5MGd2gDg 4GEUtwLLWdG8w9twTBnvCRyglnQjz4qXm/4FkkirBzMG/ezGNQjooDNZyvhYRkMCsEJ4Xhh28Lodx ZazGd9KNYwdR+iMxHGKFZrA9I06fn1Q1aLP1Vu1iI7dQQt6uoVstavQ8qTFJVipBuU2KXDrGcmLHz o4aK9zVs2I0ZUfJoOPcQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j7Ivn-00048M-0j; Thu, 27 Feb 2020 13:10:23 +0000 Received: from gateway34.websitewelcome.com ([192.185.149.72]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j7Ivj-00047i-KX for linux-i3c@lists.infradead.org; Thu, 27 Feb 2020 13:10:21 +0000 Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway34.websitewelcome.com (Postfix) with ESMTP id D4F576B2EEC for ; Thu, 27 Feb 2020 07:10:16 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 7IvgjRLBaSl8q7Ivgj5crS; Thu, 27 Feb 2020 07:10:16 -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=qzDnfPXQnwdKlHtoPz0jeIpy5o9H6yWTrMabKluFuZg=; b=RyWYqttgdcI7GrTHQ98ocNUFIL G8sByhHkV+6Bx16Q8Q+Mnnnkkfy4gC0h4yS8vMWLrhHfpZ5QfyradEaQlQvF7NG5orD2PcbTlDefY QjPyzb8zIFv0h3GKVYOq94Ru6eGzgpFGLyMDICkiWvXOm/6fz2ZZkfhrsYrnWaVMAQpR3dw+EfcoK 7QVD2EFoyNrY6dJvqgz6AiU6lCTWPbxqnjUumVicoGykBCuSKlpO07zvpWbFo6iXP92ojV2XilHBu 6PA9dK0CD/5QpQ5XT8QGpsdU1UiUAKkxsgfYVejIbdSl+bvJwwAsaOHCL80aqz8L0KLFVyXkv3byu nMw565cA==; Received: from [201.162.161.188] (port=40506 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j7Ive-000s4k-OE; Thu, 27 Feb 2020 07:10:15 -0600 Date: Thu, 27 Feb 2020 07:13:07 -0600 From: "Gustavo A. R. Silva" To: Vitor Soares , Boris Brezillon , =?utf-8?q?Przemys=C5=82aw?= Gaj Subject: [PATCH] i3c: master: Replace zero-length array with flexible-array member Message-ID: <20200227131307.GA24935@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 - lists.infradead.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 201.162.161.188 X-Source-L: No X-Exim-ID: 1j7Ive-000s4k-OE X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.162.161.188]:40506 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 4 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200227_051019_764998_8AF807F8 X-CRM114-Status: UNSURE ( 6.75 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [192.185.149.72 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux I3C List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=patchwork.kernel.org@lists.infradead.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/i3c/master/dw-i3c-master.c | 2 +- drivers/i3c/master/i3c-master-cdns.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c index bd26c3b9634e..5c5306cd50ec 100644 --- a/drivers/i3c/master/dw-i3c-master.c +++ b/drivers/i3c/master/dw-i3c-master.c @@ -221,7 +221,7 @@ struct dw_i3c_xfer { struct completion comp; int ret; unsigned int ncmds; - struct dw_i3c_cmd cmds[0]; + struct dw_i3c_cmd cmds[]; }; struct dw_i3c_master { diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c index 54712793709e..3fee8bd7fe20 100644 --- a/drivers/i3c/master/i3c-master-cdns.c +++ b/drivers/i3c/master/i3c-master-cdns.c @@ -388,7 +388,7 @@ struct cdns_i3c_xfer { struct completion comp; int ret; unsigned int ncmds; - struct cdns_i3c_cmd cmds[0]; + struct cdns_i3c_cmd cmds[]; }; struct cdns_i3c_data {