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 3178AC43387 for ; Wed, 9 Jan 2019 17:45:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 065EE20656 for ; Wed, 9 Jan 2019 17:45:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727112AbfAIRpB (ORCPT ); Wed, 9 Jan 2019 12:45:01 -0500 Received: from gateway20.websitewelcome.com ([192.185.65.13]:29661 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726792AbfAIRpA (ORCPT ); Wed, 9 Jan 2019 12:45:00 -0500 X-Greylist: delayed 1212 seconds by postgrey-1.27 at vger.kernel.org; Wed, 09 Jan 2019 12:45:00 EST Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway20.websitewelcome.com (Postfix) with ESMTP id 3F1A840126EE2 for ; Wed, 9 Jan 2019 11:24:47 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id hHaxg8yikdnCehHaxgEmrB; Wed, 09 Jan 2019 11:24:47 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=44100 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ghHaw-003lK6-Kn; Wed, 09 Jan 2019 11:24:46 -0600 Date: Wed, 9 Jan 2019 11:24:45 -0600 From: "Gustavo A. R. Silva" To: Peter Oberparleiter Cc: linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] gcov: use struct_size() in kzalloc() Message-ID: <20190109172445.GA15908@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: 1ghHaw-003lK6-Kn X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:44100 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 2 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 --- kernel/gcov/gcc_3_4.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/gcov/gcc_3_4.c b/kernel/gcov/gcc_3_4.c index 1e32e66c9563..2dddecbdbe6e 100644 --- a/kernel/gcov/gcc_3_4.c +++ b/kernel/gcov/gcc_3_4.c @@ -245,8 +245,7 @@ struct gcov_info *gcov_info_dup(struct gcov_info *info) /* Duplicate gcov_info. */ active = num_counter_active(info); - dup = kzalloc(sizeof(struct gcov_info) + - sizeof(struct gcov_ctr_info) * active, GFP_KERNEL); + dup = kzalloc(struct_size(dup, counts, active), GFP_KERNEL); if (!dup) return NULL; dup->version = info->version; @@ -364,8 +363,7 @@ struct gcov_iterator *gcov_iter_new(struct gcov_info *info) { struct gcov_iterator *iter; - iter = kzalloc(sizeof(struct gcov_iterator) + - num_counter_active(info) * sizeof(struct type_info), + iter = kzalloc(struct_size(iter, type_info, num_counter_active(info)), GFP_KERNEL); if (iter) iter->info = info; -- 2.20.1