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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 5358DC43387 for ; Tue, 8 Jan 2019 15:40:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21D0521019 for ; Tue, 8 Jan 2019 15:40:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728972AbfAHPkz (ORCPT ); Tue, 8 Jan 2019 10:40:55 -0500 Received: from gateway22.websitewelcome.com ([192.185.46.126]:11234 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728238AbfAHPkz (ORCPT ); Tue, 8 Jan 2019 10:40:55 -0500 Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway22.websitewelcome.com (Postfix) with ESMTP id CA40327DAF for ; Tue, 8 Jan 2019 09:40:51 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id gtUpgrwII2PzOgtUpgWdQM; Tue, 08 Jan 2019 09:40:51 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=52186 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ggtUo-001OrQ-0j; Tue, 08 Jan 2019 09:40:50 -0600 Date: Tue, 8 Jan 2019 09:40:46 -0600 From: "Gustavo A. R. Silva" To: Mathias Nyman , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] xhci: Use struct_size() in kzalloc() Message-ID: <20190108154046.GA13254@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: 189.250.130.205 X-Source-L: No X-Exim-ID: 1ggtUo-001OrQ-0j X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:52186 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 20 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 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/usb/host/xhci.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 005e65922608..7fa58c99f126 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1455,8 +1455,7 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag else num_tds = 1; - urb_priv = kzalloc(sizeof(struct urb_priv) + - num_tds * sizeof(struct xhci_td), mem_flags); + urb_priv = kzalloc(struct_size(urb_priv, td, num_tds), mem_flags); if (!urb_priv) return -ENOMEM; -- 2.20.1