From patchwork Tue Jan 8 15:28:16 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: 10752273 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 B653F13B4 for ; Tue, 8 Jan 2019 15:51:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A45B828D80 for ; Tue, 8 Jan 2019 15:51:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A27E628D9F; Tue, 8 Jan 2019 15:51:05 +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 2FA7028D80 for ; Tue, 8 Jan 2019 15:51:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728238AbfAHPvE (ORCPT ); Tue, 8 Jan 2019 10:51:04 -0500 Received: from gateway21.websitewelcome.com ([192.185.45.163]:17095 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727906AbfAHPvE (ORCPT ); Tue, 8 Jan 2019 10:51:04 -0500 X-Greylist: delayed 1364 seconds by postgrey-1.27 at vger.kernel.org; Tue, 08 Jan 2019 10:51:04 EST Received: from cm13.websitewelcome.com (cm13.websitewelcome.com [100.42.49.6]) by gateway21.websitewelcome.com (Postfix) with ESMTP id EF0AA400D1C7D for ; Tue, 8 Jan 2019 09:28:19 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id gtIhgP9i1YTGMgtIhgAcRp; Tue, 08 Jan 2019 09:28:19 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=52096 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ggtIh-001HdU-A6; Tue, 08 Jan 2019 09:28:19 -0600 Date: Tue, 8 Jan 2019 09:28:16 -0600 From: "Gustavo A. R. Silva" To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] Input: tca6416-keypad: use struct_size() in kzalloc() Message-ID: <20190108152816.GA7486@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: 189.250.130.205 X-Source-L: No X-Exim-ID: 1ggtIh-001HdU-A6 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:52096 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@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; 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 --- drivers/input/keyboard/tca6416-keypad.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c index dc983ab6c0ad..cdeef180aead 100644 --- a/drivers/input/keyboard/tca6416-keypad.c +++ b/drivers/input/keyboard/tca6416-keypad.c @@ -219,9 +219,7 @@ static int tca6416_keypad_probe(struct i2c_client *client, return -EINVAL; } - chip = kzalloc(sizeof(struct tca6416_keypad_chip) + - pdata->nbuttons * sizeof(struct tca6416_button), - GFP_KERNEL); + chip = kzalloc(struct_size(chip, buttons, pdata->nbuttons), GFP_KERNEL); input = input_allocate_device(); if (!chip || !input) { error = -ENOMEM;