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,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 5E03AC43381 for ; Tue, 19 Feb 2019 22:11:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 32ACE21479 for ; Tue, 19 Feb 2019 22:11:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729650AbfBSWK6 (ORCPT ); Tue, 19 Feb 2019 17:10:58 -0500 Received: from gateway22.websitewelcome.com ([192.185.46.187]:46817 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726986AbfBSWK6 (ORCPT ); Tue, 19 Feb 2019 17:10:58 -0500 Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway22.websitewelcome.com (Postfix) with ESMTP id 1F5256748 for ; Tue, 19 Feb 2019 16:10:57 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id wDbNgmyGRdnCewDbNgkj9N; Tue, 19 Feb 2019 16:10:57 -0600 X-Authority-Reason: nr=8 Received: from [189.250.119.20] (port=46558 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gwDbM-002YaT-16; Tue, 19 Feb 2019 16:10:56 -0600 Date: Tue, 19 Feb 2019 16:10:54 -0600 From: "Gustavo A. R. Silva" To: Clemens Ladisch , Arnd Bergmann , Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] hpet: Use struct_size() in kzalloc() Message-ID: <20190219221054.GA5263@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: 189.250.119.20 X-Source-L: No X-Exim-ID: 1gwDbM-002YaT-16 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.119.20]:46558 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 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 siz is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/char/hpet.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 9bffcd37cc7b..d0ad85900b79 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -842,7 +842,6 @@ int hpet_alloc(struct hpet_data *hdp) struct hpet_dev *devp; u32 i, ntimer; struct hpets *hpetp; - size_t siz; struct hpet __iomem *hpet; static struct hpets *last; unsigned long period; @@ -860,10 +859,8 @@ int hpet_alloc(struct hpet_data *hdp) return 0; } - siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * - sizeof(struct hpet_dev)); - - hpetp = kzalloc(siz, GFP_KERNEL); + hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs - 1), + GFP_KERNEL); if (!hpetp) return -ENOMEM; -- 2.20.1