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Re: [Xen-devel] hvmemul_virtual_to_linear() doesn't care about direction-flag?

This affects hvmemul_linear_to_phys() too, and would for example mean that a
backwards I/O string instruction in userspace that crosses a page boundary
would very likely cause I/O to/from the wrong physical pages. I've confirmed
this with a small testing patch to hvmloader. I think we need to work out
how to maintain a test suite of this kind of thing to check for regressions
in these kinds of rarer corner cases.

Obviously I'll fix this for 3.3.0 and probably roll out another release

 -- Keir

On 19/8/08 09:20, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:

> Quite a nasty omission though, and quite easily fixed. Thanks for pointing
> it out.
>  -- Keir
> On 18/8/08 19:41, "Byrne, John (HP Labs)" <john.l.byrne@xxxxxx> wrote:
>> I was following the emulation code around in xen-unstable cs 18335 and I
>> noticed that the direction flag doesn't get taken into account for the
>> segment
>> bounds checking in the 32-bit case anywhere I could see. Does anyone know
>> better?
>> Maybe no one will care, but I thought I'd mention it.
>> John Byrne
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel

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