Re: [Xen-devel] [PATCH v2 1/3] xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()

[Jan Beulich]

>>> On 29.05.19 at 11:04, <jgross@xxxxxxxx> 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>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>