Re: [PATCH v2 14/36] x86/entry/64/compat: Disable SYSENTER and SYSCALL32 entries

[Andy Lutomirski]

On Oct 8, 2015 8:40 AM, "Borislav Petkov" <bp@xxxxxxxxx> wrote:
>
> On Mon, Oct 05, 2015 at 05:48:02PM -0700, Andy Lutomirski wrote:
> > We've disabled the vDSO helpers to call them, so turn off the
> > entries entirely (temporarily) in preparation for cleaning them up.
> >
> > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> > ---
> >  arch/x86/entry/entry_64_compat.S | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
>
> What do we say for the case when someone bisects, lands at this patch
> and, as Murphy would generally do it, has a reproducer which is calling
> SYSENTER/SYSCALL32?
>
> Tough luck?

Probably.  I really hope that no one does that.  Given how problematic
those instructions are outside the vdso, it would have to be a rather
strange reproducer.

>
> --
> Regards/Gruss,
>     Boris.
>
> ECO tip #101: Trim your mails when you reply.
> --
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