crash in cpuidle_enter_state with 5.7-rc1

[Michal Suchánek]

On Tue, Apr 21, 2020 at 10:21:52PM +1000, Michael Ellerman wrote:
> Michal Suchánek <msuchanek at suse.de> writes:
> > On Mon, Apr 20, 2020 at 08:50:30AM +0200, Michal Suchánek wrote:
> >> On Mon, Apr 20, 2020 at 04:15:39PM +1000, Michael Ellerman wrote:
> >> > Michal Suchánek <msuchanek at suse.de> writes:
> > ...
> >> > 
> >> > 
> >> > And I've just hit it with your config on a machine here, but the crash
> >> > is different:
> >> That does not look like it.
> >> You don't have this part in the stack trace:
> >> > [    1.234899] [c000000007597420] [0000000000000000] 0x0
> >> > [    1.234908] [c000000007597720] [0000000000000a6d] 0xa6d
> >> > [    1.234919] [c000000007597a20] [0000000000000000] 0x0
> >> > [    1.234931] [c000000007597d20] [0000000000000004] 0x4
> >> which is somewhat random but at least on such line is always present in
> >> the traces I get. Also I always get crash in cpuidle_enter_state
> > ..
> >> > I'm going to guess it's STRICT_KERNEL_RWX that's at fault.
> >> I can try without that as well.
> >
> > Can't reproduce without STRICT_KERNEL_RWX either.
> 
> I've reproduced something similar all the way back to v5.5, though it
> seems harder to hit - sometimes 5 boots will succeed before one fails.
I only tried 3 times because I do not have automation in place to
capture these early crashes. I suppose I could tell the kernel to not
reboot on panic and try rebooting several times.
> 
> Are you testing on top of PowerVM or KVM?
PowerVM.

Thanks

Michal