From patchwork Thu Aug 23 18:51:40 2018 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: 961580 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-rtc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41xDdY4WJhz9s0n for ; Fri, 24 Aug 2018 05:15:29 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726083AbeHWWqe (ORCPT ); Thu, 23 Aug 2018 18:46:34 -0400 Received: from gateway24.websitewelcome.com ([192.185.51.253]:18199 "EHLO gateway24.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726081AbeHWWqd (ORCPT ); Thu, 23 Aug 2018 18:46:33 -0400 X-Greylist: delayed 1384 seconds by postgrey-1.27 at vger.kernel.org; Thu, 23 Aug 2018 18:46:33 EDT Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway24.websitewelcome.com (Postfix) with ESMTP id 5AF61DB055 for ; Thu, 23 Aug 2018 13:52:28 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id sui9fgJzjPvAdsuiPfek62; Thu, 23 Aug 2018 13:52:27 -0500 X-Authority-Reason: nr=8 Received: from [189.250.40.214] (port=37630 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1fsuhq-003zwt-FF; Thu, 23 Aug 2018 13:51:42 -0500 Date: Thu, 23 Aug 2018 13:51:40 -0500 From: "Gustavo A. R. Silva" To: Alessandro Zummo , Alexandre Belloni , Maxime Ripard , Chen-Yu Tsai Cc: linux-rtc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Kees Cook , "Gustavo A. R. Silva" Subject: [PATCH] rtc: sun6i: Use struct_size() in kzalloc() Message-ID: <20180823185140.GA29028@embeddedor.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) 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: 189.250.40.214 X-Source-L: No X-Exim-ID: 1fsuhq-003zwt-FF X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.40.214]:37630 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 10 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@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); Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook --- drivers/rtc/rtc-sun6i.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index 2cd5a7b..fe07310 100644 --- a/drivers/rtc/rtc-sun6i.c +++ b/drivers/rtc/rtc-sun6i.c @@ -199,8 +199,7 @@ static void __init sun6i_rtc_clk_init(struct device_node *node) if (!rtc) return; - clk_data = kzalloc(sizeof(*clk_data) + (sizeof(*clk_data->hws) * 2), - GFP_KERNEL); + clk_data = kzalloc(struct_size(clk_data, hws, 2), GFP_KERNEL); if (!clk_data) { kfree(rtc); return;