From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Ian Campbell <ijc@hellion.org.uk>,
Brian Gerst <brgerst@gmail.com>,
Christian Kujau <lists@nerdbynature.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Jeremy Fitzhardinge <jeremy@goop.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: 2.6.33-rc2: Xen/Guest switching to user mode with no user page tables
Date: Sun, 10 Jan 2010 16:49:51 +0300 [thread overview]
Message-ID: <20100110134951.GD5189@lenovo> (raw)
In-Reply-To: <20100110133628.GC5189@lenovo>
On Sun, Jan 10, 2010 at 04:36:28PM +0300, Cyrill Gorcunov wrote:
...
> >
> > With just the CS RPL fix below I see a GPF at kernel_thread_helper with
> > SS=3 (hence my hypothesis about NULL selectors and non-zero RPL above).
> > With both the SS and CS fixes things work fine.
>
> any of CS,SS loaded with NULL descriptor should lead to #GP
>
though SS with RPL=0 is allowed to be NULL descriptor in 64bit mode
> >
> > Ian.
> >
> > ---
> > Subject: xen: 64 bit kernel RPL should be 0.
> >
> ...
>
> Good catch Ian! I've noted that Xen use it's own get_kernel_rpl
> while discussing this problem in a chat. But I must admit *I simply don't know*
> what Xen does, or how it works internally (neither I have will to learn it at
> moment :)
>
> That said -- I'm happy if yor patch fixes problem (and it looks that
> get_kernel_rpl is guilty here indeed).
>
> -- Cyrill
-- Cyrill
next prev parent reply other threads:[~2010-01-10 13:49 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-06 1:03 2.6.33-rc2: Xen/Guest switching to user mode with no user page tables Christian Kujau
2010-01-06 3:38 ` Jeremy Fitzhardinge
2010-01-06 3:48 ` Christian Kujau
2010-01-06 5:14 ` Jeremy Fitzhardinge
2010-01-06 11:06 ` Christian Kujau
2010-01-06 11:21 ` Cyrill Gorcunov
2010-01-06 12:43 ` Christian Kujau
2010-01-07 19:06 ` Christian Kujau
2010-01-07 19:20 ` Cyrill Gorcunov
2010-01-07 19:31 ` Christian Kujau
2010-01-07 19:34 ` Cyrill Gorcunov
2010-01-07 19:19 ` H. Peter Anvin
2010-01-07 19:30 ` Christian Kujau
2010-01-08 21:50 ` Cyrill Gorcunov
2010-01-09 23:55 ` Christian Kujau
2010-01-10 1:50 ` Brian Gerst
2010-01-10 8:09 ` Cyrill Gorcunov
2010-01-10 12:59 ` Ian Campbell
2010-01-10 13:36 ` Cyrill Gorcunov
2010-01-10 13:49 ` Cyrill Gorcunov [this message]
2010-01-10 14:05 ` Ian Campbell
2010-01-15 8:36 ` Christian Kujau
2010-01-15 11:29 ` Ian Campbell
2010-01-15 12:03 ` Cyrill Gorcunov
2010-01-15 12:00 ` Cyrill Gorcunov
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