Messages in this thread | | | Date | Tue, 15 Jul 2014 12:05:19 -0400 | From | Boris Ostrovsky <> | Subject | Re: [PATCH] x86_64,xen,espfix: Initialize espfix on secondary CPUs |
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On 07/15/2014 11:54 AM, Andy Lutomirski wrote: > On Tue, Jul 15, 2014 at 8:45 AM, Boris Ostrovsky > <boris.ostrovsky@oracle.com> wrote: >> On 07/15/2014 11:38 AM, Konrad Rzeszutek Wilk wrote: >>> On Tue, Jul 15, 2014 at 08:26:41AM -0700, Andy Lutomirski wrote: >>>> Xen doesn't call start_secondary. >>> Duh! >>>> Cc: stable@vger.kernel.org >>>> Signed-off-by: Andy Lutomirski <luto@amacapital.net> >>>> --- >>>> >>>> espfix still doesn't seem to work on Xen (it goes boom in some way that >>>> I don't understand right now), but initializing all CPUs instead of just >>>> one of them seems like a good start. >>>> >>>> ISTM the right fix is probably to shove the espfix logic into >>>> native_iret and to tweak the paravirt logic so that native_iret always >>>> gets invoked. I suspect that Xen will need its own implementation of >>>> espfix64 in the hypervisor and that, ultimately, someone may want to >>>> stop initializing espfix64 at all on Xen guests. >>> I think just disallowing would be preferrable. >> >> I've been looking at sigreturn_64 and it seems to be crashing dom0 (with >> both mine and your patches). In kprobe_int3_handler(). > You need: > > http://lkml.kernel.org/g/c4e339882c121aa76254f2adde3fcbdf502faec2.1405099506.git.luto@amacapital.net > > The newer version of sigreturn_32 that I pushed is a much better test > -- it tests the 64-bit cases (yay thunks!) and works on kernels > without my SS sigcontext fix.
Yes, that does it. At least we don't have yet another failure mode with this, which was the biggest concern.
Thanks.
-boris
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