From patchwork Tue Jan 8 16:21:52 2019 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: 10753565 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 208A56C2 for ; Wed, 9 Jan 2019 08:16:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 109C528D33 for ; Wed, 9 Jan 2019 08:16:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0483F28DE0; Wed, 9 Jan 2019 08:16:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 36CC728D33 for ; Wed, 9 Jan 2019 08:16:01 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7C06D6E5F6; Wed, 9 Jan 2019 08:15:58 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from gateway24.websitewelcome.com (gateway24.websitewelcome.com [192.185.50.73]) by gabe.freedesktop.org (Postfix) with ESMTPS id C43206E11C for ; Tue, 8 Jan 2019 16:21:56 +0000 (UTC) Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway24.websitewelcome.com (Postfix) with ESMTP id F263A9D10FF for ; Tue, 8 Jan 2019 10:21:55 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id gu8ZgfmxqiQergu8ZghPNo; Tue, 08 Jan 2019 10:21:55 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=53138 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ggu8Z-001mhZ-3Z; Tue, 08 Jan 2019 10:21:55 -0600 Date: Tue, 8 Jan 2019 10:21:52 -0600 From: "Gustavo A. R. Silva" To: Dave Airlie , Gerd Hoffmann , David Airlie , Daniel Vetter Subject: [PATCH] qxl: Use struct_size() in kzalloc() Message-ID: <20190108162152.GA25361@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.freedesktop.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.130.205 X-Source-L: No X-Exim-ID: 1ggu8Z-001mhZ-3Z X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:53138 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 18 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-Mailman-Approved-At: Wed, 09 Jan 2019 08:15:57 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; void *entry[]; }; instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/qxl/qxl_display.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c index ce0b9c40fc21..c8642712412e 100644 --- a/drivers/gpu/drm/qxl/qxl_display.c +++ b/drivers/gpu/drm/qxl/qxl_display.c @@ -48,8 +48,8 @@ static int qxl_alloc_client_monitors_config(struct qxl_device *qdev, } if (!qdev->client_monitors_config) { qdev->client_monitors_config = kzalloc( - sizeof(struct qxl_monitors_config) + - sizeof(struct qxl_head) * count, GFP_KERNEL); + struct_size(qdev->client_monitors_config, + heads, count), GFP_KERNEL); if (!qdev->client_monitors_config) return -ENOMEM; }