From patchwork Mon Jan 7 17:26:16 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: 10750941 X-Patchwork-Delegate: jgg@ziepe.ca 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 6C30A13B5 for ; Mon, 7 Jan 2019 17:51:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5BE3D28968 for ; Mon, 7 Jan 2019 17:51:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4EFAB2896F; Mon, 7 Jan 2019 17:51:15 +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 CC91928968 for ; Mon, 7 Jan 2019 17:51:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728494AbfAGRvO (ORCPT ); Mon, 7 Jan 2019 12:51:14 -0500 Received: from gateway32.websitewelcome.com ([192.185.145.123]:16278 "EHLO gateway32.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728413AbfAGRvO (ORCPT ); Mon, 7 Jan 2019 12:51:14 -0500 X-Greylist: delayed 1496 seconds by postgrey-1.27 at vger.kernel.org; Mon, 07 Jan 2019 12:51:14 EST Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway32.websitewelcome.com (Postfix) with ESMTP id 51A6D23B96 for ; Mon, 7 Jan 2019 11:26:18 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id gYfKguVQn4FKpgYfKgMDOe; Mon, 07 Jan 2019 11:26:18 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=60228 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ggYfJ-002NsF-MX; Mon, 07 Jan 2019 11:26:17 -0600 Date: Mon, 7 Jan 2019 11:26:16 -0600 From: "Gustavo A. R. Silva" To: Doug Ledford , Jason Gunthorpe Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] IB/cm: Use struct_size() in kmalloc() Message-ID: <20190107172616.GA3099@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: 1ggYfJ-002NsF-MX X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:60228 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 11 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@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 --- drivers/infiniband/core/cm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index edb2cb758be7..af7f74faa448 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -4052,8 +4052,7 @@ static void cm_recv_handler(struct ib_mad_agent *mad_agent, atomic_long_inc(&port->counter_group[CM_RECV]. counter[attr_id - CM_ATTR_ID_OFFSET]); - work = kmalloc(sizeof(*work) + sizeof(struct sa_path_rec) * paths, - GFP_KERNEL); + work = kmalloc(struct_size(work, path, paths), GFP_KERNEL); if (!work) { ib_free_recv_mad(mad_recv_wc); return;