From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932749AbeBVOEV (ORCPT ); Thu, 22 Feb 2018 09:04:21 -0500 Received: from foss.arm.com ([217.140.101.70]:41796 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932573AbeBVOEU (ORCPT ); Thu, 22 Feb 2018 09:04:20 -0500 Subject: Re: [PATCH] lib/dma-debug.c: fix memory leakage To: miles.chen@mediatek.com, Christoph Hellwig , Marek Szyprowski Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com References: <1519298540-3071-1-git-send-email-miles.chen@mediatek.com> From: Robin Murphy Message-ID: <6df7e9bd-2203-0692-97e4-8c6434304b0f@arm.com> Date: Thu, 22 Feb 2018 14:04:17 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1519298540-3071-1-git-send-email-miles.chen@mediatek.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/02/18 11:22, miles.chen@mediatek.com wrote: > From: Miles Chen > > Marty reported a memory leakage introduced by commit 3aaabbf1c39e > ("lib/dma-debug.c: fix incorrect pfn calculation"). Fix it > by checking the virtual address before allocating the entry. Oops, seems I failed to look closely enough at the surrounding diff context when I reviewed the original patch... :( > This patch also use virt_addr_valid() instead of virt_to_page() > to check if a virtual address is linear. That's an area I happen to have been looking at lately and now understand a lot better, so fully agreed there as well. Acked-by: Robin Murphy Maybe also worth having a proper Fixes: tag instead of just naming the commit in prose? Thanks, Robin. > Reported-by: Marty Faltesek > Signed-off-by: Miles Chen > --- > lib/dma-debug.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/lib/dma-debug.c b/lib/dma-debug.c > index 1b34d210452c..7f5cdc1e6b29 100644 > --- a/lib/dma-debug.c > +++ b/lib/dma-debug.c > @@ -1491,12 +1491,12 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size, > if (unlikely(virt == NULL)) > return; > > - entry = dma_entry_alloc(); > - if (!entry) > + /* handle vmalloc and linear addresses */ > + if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt)) > return; > > - /* handle vmalloc and linear addresses */ > - if (!is_vmalloc_addr(virt) && !virt_to_page(virt)) > + entry = dma_entry_alloc(); > + if (!entry) > return; > > entry->type = dma_debug_coherent; > @@ -1528,7 +1528,7 @@ void debug_dma_free_coherent(struct device *dev, size_t size, > }; > > /* handle vmalloc and linear addresses */ > - if (!is_vmalloc_addr(virt) && !virt_to_page(virt)) > + if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt)) > return; > > if (is_vmalloc_addr(virt)) >