From patchwork Wed Apr 3 15:37:44 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: 10884033 X-Patchwork-Delegate: johannes@sipsolutions.net 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 00960922 for ; Wed, 3 Apr 2019 15:37:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DB1C228795 for ; Wed, 3 Apr 2019 15:37:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CEBC128827; Wed, 3 Apr 2019 15:37:47 +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 5965A28795 for ; Wed, 3 Apr 2019 15:37:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726269AbfDCPhq (ORCPT ); Wed, 3 Apr 2019 11:37:46 -0400 Received: from gateway34.websitewelcome.com ([192.185.148.200]:40572 "EHLO gateway34.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725990AbfDCPhq (ORCPT ); Wed, 3 Apr 2019 11:37:46 -0400 X-Greylist: delayed 351 seconds by postgrey-1.27 at vger.kernel.org; Wed, 03 Apr 2019 11:37:46 EDT Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway34.websitewelcome.com (Postfix) with ESMTP id C709C12E1E4 for ; Wed, 3 Apr 2019 10:37:45 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id BhxRhL3ijdnCeBhxRhASMm; Wed, 03 Apr 2019 10:37:45 -0500 X-Authority-Reason: nr=8 Received: from [189.250.114.183] (port=41268 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1hBhxR-000tLH-2O; Wed, 03 Apr 2019 10:37:45 -0500 Date: Wed, 3 Apr 2019 10:37:44 -0500 From: "Gustavo A. R. Silva" To: Johannes Berg , "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] nl80211: Use struct_size() in kzalloc() Message-ID: <20190403153744.GA14333@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: 189.250.114.183 X-Source-L: No X-Exim-ID: 1hBhxR-000tLH-2O X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.114.183]:41268 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 8 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; struct boo entry[]; }; size = sizeof(struct foo) + count * sizeof(struct boo); instance = kzalloc(size, 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) Notice that, in this case, variable size_of_regd is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- net/wireless/nl80211.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index e7ee18ab6cb7..f8bca386c904 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3843,8 +3843,7 @@ static struct cfg80211_acl_data *parse_acl_data(struct wiphy *wiphy, if (n_entries > wiphy->max_acl_mac_addrs) return ERR_PTR(-ENOTSUPP); - acl = kzalloc(sizeof(*acl) + (sizeof(struct mac_address) * n_entries), - GFP_KERNEL); + acl = kzalloc(struct_size(acl, mac_addrs, n_entries), GFP_KERNEL); if (!acl) return ERR_PTR(-ENOMEM); @@ -6882,7 +6881,7 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info) struct nlattr *nl_reg_rule; char *alpha2; int rem_reg_rules, r; - u32 num_rules = 0, rule_idx = 0, size_of_regd; + u32 num_rules = 0, rule_idx = 0; enum nl80211_dfs_regions dfs_region = NL80211_DFS_UNSET; struct ieee80211_regdomain *rd; @@ -6907,10 +6906,7 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info) if (!reg_is_valid_request(alpha2)) return -EINVAL; - size_of_regd = sizeof(struct ieee80211_regdomain) + - num_rules * sizeof(struct ieee80211_reg_rule); - - rd = kzalloc(size_of_regd, GFP_KERNEL); + rd = kzalloc(struct_size(rd, reg_rules, num_rules), GFP_KERNEL); if (!rd) return -ENOMEM;