Messages in this thread |  | | | Date | Sun, 10 Jan 2010 16:49:51 +0300 | | From | Cyrill Gorcunov <> | | Subject | Re: 2.6.33-rc2: Xen/Guest switching to user mode with no user page tables |
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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
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