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=unavailable 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 0F997C43387 for ; Tue, 8 Jan 2019 18:19:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD14620685 for ; Tue, 8 Jan 2019 18:19:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729153AbfAHSTN (ORCPT ); Tue, 8 Jan 2019 13:19:13 -0500 Received: from gateway23.websitewelcome.com ([192.185.50.119]:31603 "EHLO gateway23.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727484AbfAHSTN (ORCPT ); Tue, 8 Jan 2019 13:19:13 -0500 X-Greylist: delayed 1427 seconds by postgrey-1.27 at vger.kernel.org; Tue, 08 Jan 2019 13:19:12 EST Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway23.websitewelcome.com (Postfix) with ESMTP id E82DE10116 for ; Tue, 8 Jan 2019 11:55:24 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id gvb2ghUF6iQergvb2gj5st; Tue, 08 Jan 2019 11:55:24 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=54522 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ggvb1-002g4c-LH; Tue, 08 Jan 2019 11:55:24 -0600 Date: Tue, 8 Jan 2019 11:55:19 -0600 From: "Gustavo A. R. Silva" To: Johannes Berg , Emmanuel Grumbach , Luca Coelho , Intel Linux Wireless , Kalle Valo , "David S. Miller" Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] iwlwifi: nvm-parse: use struct_size() in kzalloc() Message-ID: <20190108175519.GA8878@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: 1ggvb1-002g4c-LH X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:54522 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 24 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@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 --- .../net/wireless/intel/iwlwifi/iwl-nvm-parse.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c index d9afedc3d1d9..8c720b42dc36 100644 --- a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c +++ b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c @@ -947,15 +947,13 @@ iwl_parse_nvm_data(struct iwl_trans *trans, const struct iwl_cfg *cfg, const __le16 *ch_section; if (cfg->nvm_type != IWL_NVM_EXT) - data = kzalloc(sizeof(*data) + - sizeof(struct ieee80211_channel) * - IWL_NVM_NUM_CHANNELS, - GFP_KERNEL); + data = kzalloc(struct_size(data, channels, + IWL_NVM_NUM_CHANNELS), + GFP_KERNEL); else - data = kzalloc(sizeof(*data) + - sizeof(struct ieee80211_channel) * - IWL_NVM_NUM_CHANNELS_EXT, - GFP_KERNEL); + data = kzalloc(struct_size(data, channels, + IWL_NVM_NUM_CHANNELS_EXT), + GFP_KERNEL); if (!data) return NULL; @@ -1444,9 +1442,7 @@ struct iwl_nvm_data *iwl_get_nvm(struct iwl_trans *trans, if (empty_otp) IWL_INFO(trans, "OTP is empty\n"); - nvm = kzalloc(sizeof(*nvm) + - sizeof(struct ieee80211_channel) * IWL_NUM_CHANNELS, - GFP_KERNEL); + nvm = kzalloc(struct_size(nvm, channels, IWL_NUM_CHANNELS), GFP_KERNEL); if (!nvm) { ret = -ENOMEM; goto out; -- 2.20.1