From patchwork Tue Jan 8 19:37:14 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: 10752833 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 17E9F91E for ; Tue, 8 Jan 2019 20:24:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F2B6F28C96 for ; Tue, 8 Jan 2019 20:24:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E6C9A28D37; Tue, 8 Jan 2019 20:24:40 +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 7A54A28C96 for ; Tue, 8 Jan 2019 20:24:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728987AbfAHUYj (ORCPT ); Tue, 8 Jan 2019 15:24:39 -0500 Received: from gateway36.websitewelcome.com ([50.116.125.2]:14460 "EHLO gateway36.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728469AbfAHUYj (ORCPT ); Tue, 8 Jan 2019 15:24:39 -0500 X-Greylist: delayed 1501 seconds by postgrey-1.27 at vger.kernel.org; Tue, 08 Jan 2019 15:24:39 EST Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway36.websitewelcome.com (Postfix) with ESMTP id D56AE40164968 for ; Tue, 8 Jan 2019 12:49:20 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id gxBegwCYi2PzOgxBegaqts; Tue, 08 Jan 2019 13:37:18 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=57412 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ggxBd-003gLX-F1; Tue, 08 Jan 2019 13:37:17 -0600 Date: Tue, 8 Jan 2019 13:37:14 -0600 From: "Gustavo A. R. Silva" To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] bio-integrity: use struct_size() in kmalloc() Message-ID: <20190108193714.GA24832@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: 1ggxBd-003gLX-F1 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:57412 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 6 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@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 = kmalloc(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 = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- block/bio-integrity.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/bio-integrity.c b/block/bio-integrity.c index 1b633a3526d4..ae8c68ecc0ca 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -57,8 +57,8 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, unsigned inline_vecs; if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) { - bip = kmalloc(sizeof(struct bio_integrity_payload) + - sizeof(struct bio_vec) * nr_vecs, gfp_mask); + bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), + gfp_mask); inline_vecs = nr_vecs; } else { bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);