From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B6A3C76191 for ; Fri, 26 Jul 2019 06:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0EDE2217D4 for ; Fri, 26 Jul 2019 06:30:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726120AbfGZGa3 (ORCPT ); Fri, 26 Jul 2019 02:30:29 -0400 Received: from verein.lst.de ([213.95.11.211]:41842 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725925AbfGZGa3 (ORCPT ); Fri, 26 Jul 2019 02:30:29 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id CEB8F227A81; Fri, 26 Jul 2019 08:30:25 +0200 (CEST) Date: Fri, 26 Jul 2019 08:30:25 +0200 From: Christoph Hellwig To: Nicolin Chen Cc: dafna.hirschfeld@collabora.com, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] dma-contiguous: page-align the size in dma_free_contiguous() Message-ID: <20190726063025.GF22881@lst.de> References: <20190725233959.15129-1-nicoleotsuka@gmail.com> <20190725233959.15129-3-nicoleotsuka@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190725233959.15129-3-nicoleotsuka@gmail.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 25, 2019 at 04:39:59PM -0700, Nicolin Chen wrote: > According to the original dma_direct_alloc_pages() code: > { > unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; > > if (!dma_release_from_contiguous(dev, page, count)) > __free_pages(page, get_order(size)); > } > > The count parameter for dma_release_from_contiguous() was page > aligned before the right-shifting operation, while the new API > dma_free_contiguous() forgets to have PAGE_ALIGN() at the size. > > So this patch simply adds it to prevent any corner case. > > Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") > Signed-off-by: Nicolin Chen Looks good, Reviewed-by: Christoph Hellwig