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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 C9BF2C169C4 for ; Thu, 31 Jan 2019 17:11:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A74ED2087F for ; Thu, 31 Jan 2019 17:11:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730004AbfAaRLS (ORCPT ); Thu, 31 Jan 2019 12:11:18 -0500 Received: from smtprelay0104.hostedemail.com ([216.40.44.104]:33996 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726481AbfAaRLR (ORCPT ); Thu, 31 Jan 2019 12:11:17 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay05.hostedemail.com (Postfix) with ESMTP id 0EF431802EC2A; Thu, 31 Jan 2019 17:11:16 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: wind88_623057b075b3a X-Filterd-Recvd-Size: 2456 Received: from XPS-9350 (unknown [149.142.244.94]) (Authenticated sender: joe@perches.com) by omf18.hostedemail.com (Postfix) with ESMTPA; Thu, 31 Jan 2019 17:11:14 +0000 (UTC) Message-ID: Subject: Re: [PATCH net-next] nfp: use struct_size() in kzalloc() From: Joe Perches To: "Gustavo A. R. Silva" , Jakub Kicinski , "David S. Miller" Cc: oss-drivers@netronome.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 31 Jan 2019 09:11:12 -0800 In-Reply-To: <20190131003859.GA28539@embeddedor> References: <20190131003859.GA28539@embeddedor> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.30.1-1build1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-01-30 at 18:38 -0600, 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; > struct boo entry[]; > }; > > instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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. Might be useful to augment the script to include cases where the computed size is saved to a temporary and that temporary is used ala: https://patchwork.kernel.org/patch/10782453/ On Sat, 2019-01-26 at 20:42 +0800, YueHaibing wrote: > Use kmemdup rather than duplicating its implementation [] > diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c [] > @@ -1196,13 +1196,9 @@ iwl_parse_nvm_mcc_info(struct device *dev, const struct iwl_cfg *cfg, > regd_to_copy = sizeof(struct ieee80211_regdomain) + > valid_rules * sizeof(struct ieee80211_reg_rule); > - copy_rd = kzalloc(regd_to_copy, GFP_KERNEL); > - if (!copy_rd) { > + copy_rd = kmemdup(regd, regd_to_copy, GFP_KERNEL); This should probably be copy_rd = kmemdup(regd, struct_size(regd, reg_rules, valid_rules), GFP_KERNEL);