iommu: Handle default domain attach failure

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commit 797a8b4d76 upstream.

We wouldn't normally expect ops->attach_dev() to fail, but on IOMMUs
with limited hardware resources, or generally misconfigured systems,
it is certainly possible. We report failure correctly from the external
iommu_attach_device() interface, but do not do so in iommu_group_add()
when attaching to the default domain. The result of failure there is
that the device, group and domain all get left in a broken,
part-configured state which leads to weird errors and misbehaviour down
the line when IOMMU API calls sort-of-but-don't-quite work.

Check the return value of __iommu_attach_device() on the default domain,
and refactor the error handling paths to cope with its failure and clean
up correctly in such cases.

Fixes: e39cb8a3aa ("iommu: Make sure a device is always attached to a domain")
Reported-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Robin Murphy 2017-01-16 12:58:07 +00:00 • committed by Greg Kroah-Hartman

parent c19bfc6765

commit d7fcb303d1

1 changed files with 24 additions and 13 deletions

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drivers/iommu/iommu.c

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