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_HELO_NONE,SPF_PASS, 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 0B630C28CC5 for ; Wed, 5 Jun 2019 14:45:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF78620693 for ; Wed, 5 Jun 2019 14:45:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728482AbfFEOpV (ORCPT ); Wed, 5 Jun 2019 10:45:21 -0400 Received: from gateway32.websitewelcome.com ([192.185.145.178]:28915 "EHLO gateway32.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727960AbfFEOpU (ORCPT ); Wed, 5 Jun 2019 10:45:20 -0400 Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway32.websitewelcome.com (Postfix) with ESMTP id 854432CE0CF for ; Wed, 5 Jun 2019 09:45:19 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id YXAFhfh8P4FKpYXAFhzcUD; Wed, 05 Jun 2019 09:45:19 -0500 X-Authority-Reason: nr=8 Received: from [189.250.127.120] (port=52510 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1hYXAE-000ldx-M1; Wed, 05 Jun 2019 09:45:18 -0500 Date: Wed, 5 Jun 2019 09:45:16 -0500 From: "Gustavo A. R. Silva" To: Jiri Pirko Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] lib: objagg: Use struct_size() in kzalloc() Message-ID: <20190605144516.GA3383@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: 189.250.127.120 X-Source-L: No X-Exim-ID: 1hYXAE-000ldx-M1 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.127.120]:52510 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 4 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 objagg_stats { ... struct objagg_obj_stats_info stats_info[]; }; size = sizeof(*objagg_stats) + sizeof(objagg_stats->stats_info[0]) * count; 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, stats_info, count), GFP_KERNEL); Notice that, in this case, variable alloc_size is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- lib/objagg.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/lib/objagg.c b/lib/objagg.c index 576be22e86de..55621fb82e0a 100644 --- a/lib/objagg.c +++ b/lib/objagg.c @@ -605,12 +605,10 @@ const struct objagg_stats *objagg_stats_get(struct objagg *objagg) { struct objagg_stats *objagg_stats; struct objagg_obj *objagg_obj; - size_t alloc_size; int i; - alloc_size = sizeof(*objagg_stats) + - sizeof(objagg_stats->stats_info[0]) * objagg->obj_count; - objagg_stats = kzalloc(alloc_size, GFP_KERNEL); + objagg_stats = kzalloc(struct_size(objagg_stats, stats_info, + objagg->obj_count), GFP_KERNEL); if (!objagg_stats) return ERR_PTR(-ENOMEM); -- 2.21.0