when the going gets panic, the tough goes kdump

NOTE: kdump is a service that can use kexec tool to create a log-and-core dump into some place in case of kernel panic by pre-loading an additional (rescue) kernel somewhere in memory

I discovered that last year because Red Hat Linux was doing it automatically when a crash occurred (and well, being developing drivers rather than embedded device, it is bound to happen again), but if I remember correctly, one can also --install  and ./configure it on Ubuntu.

When the kernel isn't entering PANIC, though, it could raise a WARN, where you still see a registers and stack dump, but things keep rolling. It might be telling you that something is unsafe and might have triggered a deadlock if we weren't so lucky, though. Better listen to them.