From patchwork Mon Feb 18 18:59:37 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: 10818649 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 CD1226C2 for ; Mon, 18 Feb 2019 19:23:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AED5A2B8EB for ; Mon, 18 Feb 2019 19:23:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2B242B8FF; Mon, 18 Feb 2019 19:23:41 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 479D72B8EB for ; Mon, 18 Feb 2019 19:23:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725836AbfBRTXk (ORCPT ); Mon, 18 Feb 2019 14:23:40 -0500 Received: from gateway22.websitewelcome.com ([192.185.47.109]:36206 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725775AbfBRTXk (ORCPT ); Mon, 18 Feb 2019 14:23:40 -0500 X-Greylist: delayed 1440 seconds by postgrey-1.27 at vger.kernel.org; Mon, 18 Feb 2019 14:23:39 EST Received: from cm13.websitewelcome.com (cm13.websitewelcome.com [100.42.49.6]) by gateway22.websitewelcome.com (Postfix) with ESMTP id BB2B27414 for ; Mon, 18 Feb 2019 12:59:38 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id vo8ggNw7WYTGMvo8gggV3u; Mon, 18 Feb 2019 12:59:38 -0600 X-Authority-Reason: nr=8 Received: from [189.250.119.20] (port=44090 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gvo8f-000YWs-Qu; Mon, 18 Feb 2019 12:59:37 -0600 Date: Mon, 18 Feb 2019 12:59:37 -0600 From: "Gustavo A. R. Silva" To: Minas Harutyunyan , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] usb: dwc2: use struct_size() in kzalloc() Message-ID: <20190218185937.GA16947@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: 189.250.119.20 X-Source-L: No X-Exim-ID: 1gvo8f-000YWs-Qu X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.119.20]:44090 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 15 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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; struct boo entry[]; }; size = sizeof(struct foo) + count * sizeof(struct boo); instance = kzalloc(size, 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); Notice that, in this case, variable size is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/usb/dwc2/hcd.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index dd82fa516f3f..3f087962f498 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -3981,10 +3981,8 @@ static struct dwc2_hcd_urb *dwc2_hcd_urb_alloc(struct dwc2_hsotg *hsotg, gfp_t mem_flags) { struct dwc2_hcd_urb *urb; - u32 size = sizeof(*urb) + iso_desc_count * - sizeof(struct dwc2_hcd_iso_packet_desc); - urb = kzalloc(size, mem_flags); + urb = kzalloc(struct_size(urb, iso_descs, iso_desc_count), mem_flags); if (urb) urb->packet_count = iso_desc_count; return urb;