Messages in this thread | | | Date | Mon, 16 Nov 2015 20:59:06 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH] xen/x86: Adjust stack pointer in xen_sysexit |
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On Mon, Nov 16, 2015 at 11:03:22AM -0800, Andy Lutomirski wrote:
> ... > The reader surely doesn't remember that this isn't guaranteed to be a > swapgs instruction on native. Using: > > ALTERNATIVE "swapgs" "" X86_FEATURE_XENPV > > would be safer (it would get rid of the SWAPGS_UNSAFE_STACK mess) and > much clearer. We could hide *that* behind a macro and no one would be > confused. (Well, they'd be confused by the fact that Xen PV handles > gsbase very differently from native, but that has nothing to do with > the macro.) > > I think we could convert piecemeal, and I wonder if this new patch for > 32-bit native on 4.4 (this is needed for 4.4, right?) would be a good > starting point. Borislav, what do you think? Would you be okay with > adding a Xen PV pseudofeature?
AFAICT, I'd prefer this becomes rather a jump label which gets enabled on xen. Especially if a single pseudofeature might not be enough, apprently...
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply.
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