From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH v4 3/6] iommu: add ARM short descriptor page table allocator. Date: Fri, 9 Oct 2015 16:57:50 +0100 Message-ID: <20151009155750.GS26278@arm.com> References: <1438597279-2937-1-git-send-email-yong.wu@mediatek.com> <1438597279-2937-4-git-send-email-yong.wu@mediatek.com> <20150916155824.GM28771@arm.com> <1442501662.8145.151.camel@mhfsdcap03> <1442931167.17514.39.camel@mhfsdcap03> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1442931167.17514.39.camel@mhfsdcap03> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Yong Wu Cc: Robin Murphy , Mark Rutland , Catalin Marinas , "youhua.li-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org" , Thierry Reding , "k.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "arnd-r2nGTMty4D4@public.gmane.org" , Tomasz Figa , Rob Herring , "linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Matthias Brugger , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "pebolle-IWqWACnzNjzz+pZb47iToQ@public.gmane.org" , "frederic.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org" , "srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" List-Id: iommu@lists.linux-foundation.org On Tue, Sep 22, 2015 at 03:12:47PM +0100, Yong Wu wrote: > I would like to show you a problem I met, The recursion here may > lead to stack overflow while we test FHD video decode. > > From the log, I get the internal variable in the error case: the > "size" is 0x100000, the "iova" is 0xfea00000, but at that time the > "blk_size" is 0x1000 as it was the map of small-page. so it enter the > recursion here. > > After check the unmap flow, there is only a iommu_unmap in > __iommu_dma_unmap, and it won't check the physical address align in > iommu_unmap. That sounds like a bug in __iommu_dma_unmap. Robin? Will -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Fri, 9 Oct 2015 16:57:50 +0100 Subject: [PATCH v4 3/6] iommu: add ARM short descriptor page table allocator. In-Reply-To: <1442931167.17514.39.camel@mhfsdcap03> References: <1438597279-2937-1-git-send-email-yong.wu@mediatek.com> <1438597279-2937-4-git-send-email-yong.wu@mediatek.com> <20150916155824.GM28771@arm.com> <1442501662.8145.151.camel@mhfsdcap03> <1442931167.17514.39.camel@mhfsdcap03> Message-ID: <20151009155750.GS26278@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Sep 22, 2015 at 03:12:47PM +0100, Yong Wu wrote: > I would like to show you a problem I met, The recursion here may > lead to stack overflow while we test FHD video decode. > > From the log, I get the internal variable in the error case: the > "size" is 0x100000, the "iova" is 0xfea00000, but at that time the > "blk_size" is 0x1000 as it was the map of small-page. so it enter the > recursion here. > > After check the unmap flow, there is only a iommu_unmap in > __iommu_dma_unmap, and it won't check the physical address align in > iommu_unmap. That sounds like a bug in __iommu_dma_unmap. Robin? Will From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932796AbbJIP54 (ORCPT ); Fri, 9 Oct 2015 11:57:56 -0400 Received: from foss.arm.com ([217.140.101.70]:40134 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932253AbbJIP5z (ORCPT ); Fri, 9 Oct 2015 11:57:55 -0400 Date: Fri, 9 Oct 2015 16:57:50 +0100 From: Will Deacon To: Yong Wu Cc: Robin Murphy , Mark Rutland , Catalin Marinas , "youhua.li@mediatek.com" , Thierry Reding , "k.zhang@mediatek.com" , "devicetree@vger.kernel.org" , "arnd@arndb.de" , Tomasz Figa , Rob Herring , "linux-mediatek@lists.infradead.org" , Matthias Brugger , "linux-arm-kernel@lists.infradead.org" , "pebolle@tiscali.nl" , "frederic.chen@mediatek.com" , "srv_heupstream@mediatek.com" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , Daniel Kurtz , Sasha Hauer , Lucas Stach Subject: Re: [PATCH v4 3/6] iommu: add ARM short descriptor page table allocator. Message-ID: <20151009155750.GS26278@arm.com> References: <1438597279-2937-1-git-send-email-yong.wu@mediatek.com> <1438597279-2937-4-git-send-email-yong.wu@mediatek.com> <20150916155824.GM28771@arm.com> <1442501662.8145.151.camel@mhfsdcap03> <1442931167.17514.39.camel@mhfsdcap03> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1442931167.17514.39.camel@mhfsdcap03> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 22, 2015 at 03:12:47PM +0100, Yong Wu wrote: > I would like to show you a problem I met, The recursion here may > lead to stack overflow while we test FHD video decode. > > From the log, I get the internal variable in the error case: the > "size" is 0x100000, the "iova" is 0xfea00000, but at that time the > "blk_size" is 0x1000 as it was the map of small-page. so it enter the > recursion here. > > After check the unmap flow, there is only a iommu_unmap in > __iommu_dma_unmap, and it won't check the physical address align in > iommu_unmap. That sounds like a bug in __iommu_dma_unmap. Robin? Will