From patchwork Fri Jan 4 17:32:15 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: 10748703 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 5027A6C2 for ; Fri, 4 Jan 2019 17:56:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 427A1286F2 for ; Fri, 4 Jan 2019 17:56:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 366EA28704; Fri, 4 Jan 2019 17:56:05 +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=unavailable 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 D53F0286F2 for ; Fri, 4 Jan 2019 17:56:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726511AbfADR4E (ORCPT ); Fri, 4 Jan 2019 12:56:04 -0500 Received: from gateway22.websitewelcome.com ([192.185.47.206]:16650 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726448AbfADR4E (ORCPT ); Fri, 4 Jan 2019 12:56:04 -0500 X-Greylist: delayed 1420 seconds by postgrey-1.27 at vger.kernel.org; Fri, 04 Jan 2019 12:56:04 EST Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway22.websitewelcome.com (Postfix) with ESMTP id DCF006578 for ; Fri, 4 Jan 2019 11:32:21 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id fTKXgqCX02PzOfTKXgVyzO; Fri, 04 Jan 2019 11:32:21 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=35258 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gfTKW-000Ohm-4r; Fri, 04 Jan 2019 11:32:21 -0600 Date: Fri, 4 Jan 2019 11:32:15 -0600 From: "Gustavo A. R. Silva" To: Andy Gross , David Brown , Dan Williams , Vinod Koul Cc: linux-arm-msm@vger.kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] dmaengine: qcom: bam_dma: use struct_size() in kzalloc() Message-ID: <20190104173215.GA29029@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: 1gfTKW-000Ohm-4r X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:35258 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 29 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@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/dma/qcom/bam_dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 1617715aa6e0..cb860cb53c27 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -636,8 +636,8 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan, num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE); /* allocate enough room to accomodate the number of entries */ - async_desc = kzalloc(sizeof(*async_desc) + - (num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT); + async_desc = kzalloc(struct_size(async_desc, desc, num_alloc), + GFP_NOWAIT); if (!async_desc) goto err_out;