linux-kernel - Re: [PATCH 03/22] iommu: Propagate error in add_iommu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20150629093703.GA16648@suse.de>
Date:	Mon, 29 Jun 2015 11:37:03 +0200
From:	Joerg Roedel <jroedel@...e.de>
To:	Heiko Stübner <heiko@...ech.de>
Cc:	Joerg Roedel <joro@...tes.org>, djkurtz@...omium.org,
	Tomasz Figa <tfiga@...omium.org>,
	iommu@...ts.linux-foundation.org,
	Will Deacon <will.deacon@....com>,
	Kukjin Kim <kgene@...nel.org>,
	David Woodhouse <dwmw2@...radead.org>,
	Hiroshi Doyu <hdoyu@...dia.com>,
	Thierry Reding <thierry.reding@...il.com>,
	Alex Williamson <alex.williamson@...hat.com>,
	Robin Murphy <robin.murphy@....com>,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Oded Gabbay <oded.gabbay@...il.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 03/22] iommu: Propagate error in add_iommu_group

Hello Heiko,

On Mon, Jun 29, 2015 at 11:28:40AM +0200, Heiko Stübner wrote:
> The Rockchip iommu uses bus_set_ops to set its iommu-ops for the platform
> bus and currently returns -ENODEV if it encounters a platform_devices that
> does not have an iommu. As add_iommu_group ignored these returns
> till now this worked, but of course starts to fail now.
> 
> All two invocations of the add_device callback ignored (or still ignore) the
> return value so I've come with the following small patch to fix the breakage
> that now exists in the 4.2 tree.
> 
> There is probably a better solution possible in the longer term, likely
> similar to what Samsung does, but I'm not sure yet how this would work
> with our drm device that needs an iommu mapping without having an
> iommu (the iommus being attached to the crtc-components).

Yes, this issue was already reported from the Exynos side. I have a fix
which just ignores -ENODEV as the return value for now. This fixes
Exynos, and should fix Rockchip (and some other IOMMU drivers) too.


	Joerg

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/