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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 A1B55C282C3 for ; Thu, 24 Jan 2019 17:33:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B48121872 for ; Thu, 24 Jan 2019 17:33:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729108AbfAXRd5 (ORCPT ); Thu, 24 Jan 2019 12:33:57 -0500 Received: from gateway30.websitewelcome.com ([192.185.145.3]:44319 "EHLO gateway30.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727573AbfAXRd4 (ORCPT ); Thu, 24 Jan 2019 12:33:56 -0500 Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway30.websitewelcome.com (Postfix) with ESMTP id 4544C46784 for ; Thu, 24 Jan 2019 11:33:53 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id miszg14bx2PzOmiszgbH2j; Thu, 24 Jan 2019 11:33:53 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=42518 helo=[192.168.1.76]) by gator4166.hostgator.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.91) (envelope-from ) id 1gmisy-0004nO-V3; Thu, 24 Jan 2019 11:33:53 -0600 Subject: Re: [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc() To: "Rafael J. Wysocki" , Viresh Kumar Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190107173343.GA4258@embeddedor> <20190108050056.quckhd2d5ah4ywax@vireshk-i7> <1645829.9I2fkU6ktd@aspire.rjw.lan> From: "Gustavo A. R. Silva" Openpgp: preference=signencrypt Message-ID: Date: Thu, 24 Jan 2019 11:33:52 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <1645829.9I2fkU6ktd@aspire.rjw.lan> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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: 1gmisy-0004nO-V3 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: ([192.168.1.76]) [189.250.130.205]:42518 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 7 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 On 1/24/19 4:34 AM, Rafael J. Wysocki wrote: > On Tuesday, January 8, 2019 6:00:56 AM CET Viresh Kumar wrote: >> On 07-01-19, 11:33, Gustavo A. R. Silva wrote: >>> 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/cpufreq/e_powersaver.c | 5 ++--- >>> 1 file changed, 2 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c >>> index 60bea302abbe..2d3ef208dd70 100644 >>> --- a/drivers/cpufreq/e_powersaver.c >>> +++ b/drivers/cpufreq/e_powersaver.c >>> @@ -323,9 +323,8 @@ static int eps_cpu_init(struct cpufreq_policy *policy) >>> states = 2; >>> >>> /* Allocate private data and frequency table for current cpu */ >>> - centaur = kzalloc(sizeof(*centaur) >>> - + (states + 1) * sizeof(struct cpufreq_frequency_table), >>> - GFP_KERNEL); >>> + centaur = kzalloc(struct_size(centaur, freq_table, states + 1), >>> + GFP_KERNEL); >>> if (!centaur) >>> return -ENOMEM; >>> eps_cpu[0] = centaur; >> >> Acked-by: Viresh Kumar > > Patch applied, thanks! > Thank you both, Viresh and Rafael. -- Gustavo