Re: NMI hardlock stacktrace deadlock [was Re: Linux 5.2-rc5]

From: Steven Rostedt
Date: Wed Jun 26 2019 - 08:26:14 EST

On Mon, 24 Jun 2019 22:03:45 -0500
Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:

> Looking at the dmesg, panic_on_oops doesn't seem to be enabled: it went
> through the rewind_stack_do_exit() path instead of the panic() path. So
> the system is apparently not configured to reboot on oops.

"Command line: BOOT_IMAGE=/boot/drm_intel root=/dev/sda1 rootwait intel_iommu=igfx_off nmi_watchdog=panic,auto panic=5 softdog.soft_panic=5 drm.debug=0xe log_buf_len=1M 3 ro"

> So I'd say the hang was presumably caused by a lock held by the oopsing
> code. So it looks normal to me, other than the original oops.

Looks like its missing "oops=panic", as the documentation says:

oops=panic Always panic on oopses. Default is to just kill the
process, but there is a small probability of
deadlocking the machine.
This will also cause panics on machine check exceptions.
Useful together with panic=30 to trigger a reboot.

-- Steve