From patchwork Tue Jan 8 17:55:19 2019 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: 10752737 X-Patchwork-Delegate: luca@coelho.fi Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 29C2E746 for ; Tue, 8 Jan 2019 18:19:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1869428E44 for ; Tue, 8 Jan 2019 18:19:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0B9C828E59; Tue, 8 Jan 2019 18:19:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 90E2628E44 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-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 X-Virus-Scanned: ClamAV using ClamSMTP 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;