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Date: Fri, 30 Jan 2015 13:29:19 +0100
From: Joerg Roedel <joro@8bytes.org>
To: Will Deacon <will.deacon@arm.com>
Cc: "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>,
        Kukjin Kim <kgene@kernel.org>, David Woodhouse <dwmw2@infradead.org>,
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        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        "jroedel@suse.de" <jroedel@suse.de>
Subject: Re: [PATCH 4/5] iommu: Make sure a device is always attached to a
 domain
Message-ID: <20150130122919.GD3702@8bytes.org>
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 <20150128143852.GS1569@arm.com>
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On Wed, Jan 28, 2015 at 02:38:52PM +0000, Will Deacon wrote:
> On Tue, Jan 27, 2015 at 12:08:58AM +0000, Joerg Roedel wrote:
> > -	return iommu_group_for_each_dev(group, domain,
> > -					iommu_group_do_attach_device);
> > +	int ret;
> > +
> > +	if (group->default_domain && group->domain != group->default_domain)
> > +		return -EBUSY;
> 
> I think this is now racy with itself and detach, whereas before we always
> held the group->mutex by virtue of iommu_group_for_each_dev.

You are right, thanks. I will update the code with correct locking.


	Joerg