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Date: Sat, 15 Oct 2011 18:57:57 +0200
From: Ingo Molnar <mingo@elte.hu>
To: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Andrew Lutomirski <luto@mit.edu>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Adrian Bunk <bunk@stusta.de>, "H. Peter Anvin" <hpa@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
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Subject: Re: [RFC] fixing the UML failure root cause
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* richard -rw- weinberger <richard.weinberger@gmail.com> wrote:

> On Fri, Oct 14, 2011 at 10:17 PM, Andrew Lutomirski <luto@mit.edu> wrote:
> > On Fri, Oct 14, 2011 at 12:53 PM, richard -rw- weinberger
> > <richard.weinberger@gmail.com> wrote:
> >> On Tue, Oct 11, 2011 at 7:24 PM, Andrew Lutomirski <luto@mit.edu> wrote:
> >>> What do you think of this approach?  If it seems good, I'll finish the
> >>> patch and submit it.
> >>>
> >>> With this patch applied, UML appears to work, but it fills the log with
> >>> exploit attempt warnings.  Any ideas on what to do about that?
> >>>
> >>
> >> I can confirm that this patch works.
> >> And I really like vsyscall=emulate because with that UML can trap vsyscalls. :-)
> >
> > Are you sure you don't mean vsyscall=native?  I suspect that UML can't
> > actually trap vsyscalls in emulate mode right now, although that ought
> > to be fixable.
> >
> 
> §/%)"&!, you are so right!
> I missed that vsyscall=native is the default setting now.
> Sorry for the confusion.

Switch back to vsyscall=native was just a temporary ABI fix for v3.1 
- we'd like to switch to vsyscall=emulate again ASAP (possibly in 
v3.2), once Andrew is done with the patch and everyone is happy with 
it.

Thanks,

	Ingo