From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH 4/5] iommu: Make sure a device is always attached to a
	domain
Date: Fri, 30 Jan 2015 13:29:19 +0100
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To: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Cc: "jroedel-l3A5Bk7waGM@public.gmane.org" <jroedel-l3A5Bk7waGM@public.gmane.org>, Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>, Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>, Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>, "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" <iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>, Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Kukjin Kim <kgene-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
List-Id: iommu@lists.linux-foundation.org

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