Diagnosing kernel panic on ck-sources-5.4.2-ck-r1

davydm · n00b Joined: 06 Jan 2017 Posts: 73

I've used the ck-sources kernel for quite a while (still have a bootable 5.2.3-ck image), but the recent update to 5.4.2-r1 panics immediately at boot. Unfortunately, I'm running with an NVIDIA card, so the default text mode has rather large fonts, meaning that the start of the panic scrolls past before I can read it.

I'm looking for any hints as to
- how to get the most information about the issue (considering the scroll-past)
- what would be interesting in an issue report
- is there some other place I should be looking for info?

I can compile and run gentoo-sources-5.4.3 currently, so I'm quite sure it's not that I have a broken build toolchain (though I'm open to suggestions there too). I'd like to report upstream if, indeed, the problem is not at my machine, but I first need to ascertain that the problem isn't my machine (I don't _think_ it is considering the older ck kernel and the current ~amd64 gentoo-sources kernel work fine) and then I need to get useful information for the maintainer. I don't really know where to begin with this one.

Any assistance appreciated.

Juippisi · Developer Joined: 30 Sep 2005 Posts: 761 Location: /home

Can you scroll up with shift+page up in TTY?
If you have system logging on, and even if you don't, there should be something in /var/log that helps you investigate it. Ie you can boot a live USB then go check /var/log/dmesg which should hold latest dmesg info, or just /var/log/messages, syslog, lastlog etc what you might find depending on system logger you use.

Glad that you can still boot an older kernel. What if you compile your ck-sources using config file from working gentoo-sources? Will it make it bootable?

davydm · n00b Joined: 06 Jan 2017 Posts: 73

NeddySeagoon · Posted: Sun Dec 15, 2019 3:35 pm Post subject:

davydm,

davydm · n00b Joined: 06 Jan 2017 Posts: 73

NeddySeagoon

(first, I really loved the goon show, though I haven't listened in ages)

interesting about the diagnosis -- side-note: I'd love to learn more: do you have any recommendations?

on to the information you've requested:

1. kernel .config (created via

NeddySeagoon · Posted: Sun Dec 15, 2019 9:13 pm Post subject:

davydm,

I've been playing with computers for about 55 years. Its getting difficult to remember where individual bits of knowledge came from now.
Spending most of my working life designing computer systems has helped too. :)

Everything looks OK, it just doesn't work.

From your filesystem settings, almost everything is built as a loadable module, you use an initrd containing kernel modules.
How do you build your kernel and initrd?

You kernel contains a lot of watchdog settings.
If for some reason, you don't 'pat the watchdog' in time it will either halt the system or reboot.
Watchdogs can make startup difficult because that process that tells the watchdog the system is still alive may not get run, or may not start fast enough.
This can vary from kernel to kernel too.

It would be good to test with

davydm · n00b Joined: 06 Jan 2017 Posts: 73

NeddySeagoon

I've only been playing with computers for money for about 20 years. I have much to learn!

I build the kernel and initrd with genkernel. Like most things, when there's a lot of moving parts, I tend to wrap them up in a script so I don't have to remember all of them, so here's my `rebuild-kernel` script: