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=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 BB07AC43387 for ; Wed, 9 Jan 2019 14:49:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89E202070B for ; Wed, 9 Jan 2019 14:49:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731916AbfAIOtS (ORCPT ); Wed, 9 Jan 2019 09:49:18 -0500 Received: from gateway34.websitewelcome.com ([192.185.148.231]:20710 "EHLO gateway34.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731723AbfAIOtS (ORCPT ); Wed, 9 Jan 2019 09:49:18 -0500 Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway34.websitewelcome.com (Postfix) with ESMTP id 3A69AB0449 for ; Wed, 9 Jan 2019 08:49:17 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id hFATgnNCV90onhFATgHPK5; Wed, 09 Jan 2019 08:49:17 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=41172 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ghFAS-002CM9-Il; Wed, 09 Jan 2019 08:49:16 -0600 Date: Wed, 9 Jan 2019 08:49:11 -0600 From: "Gustavo A. R. Silva" To: David Howells Cc: linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] afs: security: Use struct_size() in kzalloc() Message-ID: <20190109144911.GA11648@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: 1ghFAS-002CM9-Il X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:41172 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 8 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 --- fs/afs/security.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/afs/security.c b/fs/afs/security.c index 5f58a9a17e69..4e9a6c96b9e8 100644 --- a/fs/afs/security.c +++ b/fs/afs/security.c @@ -197,8 +197,7 @@ void afs_cache_permit(struct afs_vnode *vnode, struct key *key, * yet. */ size++; - new = kzalloc(sizeof(struct afs_permits) + - sizeof(struct afs_permit) * size, GFP_NOFS); + new = kzalloc(struct_size(new, permits, size), GFP_NOFS); if (!new) goto out_put; -- 2.20.1