On Tue, Jul 15, 2014 at 9:05 AM, Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> wrote: > On 07/15/2014 11:54 AM, Andy Lutomirski wrote: >> >> On Tue, Jul 15, 2014 at 8:45 AM, Boris Ostrovsky >> <boris.ostrovsky@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx >>>>> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> >>>>> --- >>>>> >>>>> 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@xxxxxxxxxxxxxx >> >> 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. I updated the sigreturn test again -- the new version exercises the double-fault case, too. It passes on a non-Xen kernel with the krpobes fix. --Andy > > Thanks. > > -boris > -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html