Re: [PATCH 1/3] xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()

[Boris Ostrovsky]

On 4/23/19 6:54 AM, Juergen Gross wrote:
> The condition in xen_swiotlb_free_coherent() for deciding whether to
> call xen_destroy_contiguous_region() is wrong: in case the region to
> be freed is not contiguous calling xen_destroy_contiguous_region() is
> the wrong thing to do: it would result in inconsistent mappings of
> multiple PFNs to the same MFN. This will lead to various strange
> crashes or data corruption.
>
> Instead of calling xen_destroy_contiguous_region() in that case a
> warning should be issued as that situation should never occur.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>