From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH][next] iwlwifi: mvm: use struct_size() in kzalloc() Date: Tue, 15 Jan 2019 16:02:46 -0600 Message-ID: <20190115220246.GA23339@embeddedor> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" To: Johannes Berg , Emmanuel Grumbach , Luca Coelho , Intel Linux Wireless , Kalle Valo , "David S. Miller" Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.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; 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. Signed-off-by: Gustavo A. R. Silva --- drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 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..a2b2bdc5cd09 100644 --- a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c +++ b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c @@ -947,14 +947,12 @@ 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, + 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, + 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 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 D9332C43387 for ; Tue, 15 Jan 2019 22:51:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B070220883 for ; Tue, 15 Jan 2019 22:51:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391228AbfAOWv4 (ORCPT ); Tue, 15 Jan 2019 17:51:56 -0500 Received: from gateway30.websitewelcome.com ([192.185.197.25]:40541 "EHLO gateway30.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387714AbfAOWv4 (ORCPT ); Tue, 15 Jan 2019 17:51:56 -0500 X-Greylist: delayed 1501 seconds by postgrey-1.27 at vger.kernel.org; Tue, 15 Jan 2019 17:51:55 EST Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway30.websitewelcome.com (Postfix) with ESMTP id 2E976780C for ; Tue, 15 Jan 2019 16:02:53 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id jWnNguNDbiQerjWnNgFHpn; Tue, 15 Jan 2019 16:02:53 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=53938 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gjWnK-002507-VI; Tue, 15 Jan 2019 16:02:52 -0600 Date: Tue, 15 Jan 2019 16:02:46 -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][next] iwlwifi: mvm: use struct_size() in kzalloc() Message-ID: <20190115220246.GA23339@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: 1gjWnK-002507-VI X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:53938 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 8 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Message-ID: <20190115220246.nepMeEA3UtPVLRXk7UzRnRDV3Mj2ICte1cXFtqIyMB4@z> 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. Signed-off-by: Gustavo A. R. Silva --- drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 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..a2b2bdc5cd09 100644 --- a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c +++ b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c @@ -947,14 +947,12 @@ 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, + 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, + 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