From patchwork Mon Jan 7 17:39:54 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: 10750957 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 826A36C5 for ; Mon, 7 Jan 2019 18:01:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 758A728988 for ; Mon, 7 Jan 2019 18:01:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 69CB3289A0; Mon, 7 Jan 2019 18:01:44 +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 132552899F for ; Mon, 7 Jan 2019 18:01:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727052AbfAGSBn (ORCPT ); Mon, 7 Jan 2019 13:01:43 -0500 Received: from gateway31.websitewelcome.com ([192.185.143.51]:29616 "EHLO gateway31.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727049AbfAGSBn (ORCPT ); Mon, 7 Jan 2019 13:01:43 -0500 X-Greylist: delayed 1308 seconds by postgrey-1.27 at vger.kernel.org; Mon, 07 Jan 2019 13:01:43 EST Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway31.websitewelcome.com (Postfix) with ESMTP id 1D837358F5 for ; Mon, 7 Jan 2019 11:39:55 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id gYsVgCgu690ongYsVgh4m5; Mon, 07 Jan 2019 11:39:55 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=60460 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ggYsU-002UwS-FG; Mon, 07 Jan 2019 11:39:54 -0600 Date: Mon, 7 Jan 2019 11:39:54 -0600 From: "Gustavo A. R. Silva" To: Christian Benvenuti , Doug Ledford , Jason Gunthorpe Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] IB/usnic: Use struct_size() in kmalloc() Message-ID: <20190107173953.GA6154@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: 1ggYsU-002UwS-FG X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:60460 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 20 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/hw/usnic/usnic_uiom.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 49275a548751..ce01a59fccc4 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -157,9 +157,8 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, off = 0; while (ret) { - chunk = kmalloc(sizeof(*chunk) + - sizeof(struct scatterlist) * - min_t(int, ret, USNIC_UIOM_PAGE_CHUNK), + chunk = kmalloc(struct_size(chunk, page_list, + min_t(int, ret, USNIC_UIOM_PAGE_CHUNK)), GFP_KERNEL); if (!chunk) { ret = -ENOMEM;