Re: [Xen-devel] [PATCH for-4.13] xen/arm: Don't use _end in is_xen_fixed_mfn()

[Jürgen Groß <jgross@xxxxxxxx>]

On 15.10.19 20:18, Julien Grall wrote:
> virt_to_maddr() is using the hardware page-table walk instructions to
> translate a virtual address to physical address. The function should
> only be called on virtual address mapped.
>
> _end points past the end of Xen binary and may not be mapped when the
> binary size is page-aligned. This means virt_to_maddr() will not be able
> to do the translation and therefore crash Xen.
>
> Note there is also an off-by-one issue in this code, but the panic will
> trump that.
>
> Both issues can be fixed by using _end - 1 in the check.
>
> Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
With or without the cast suggested by Stefano:

Release-acked-by: Juergen Gross <jgross@xxxxxxxx>


Juergen

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