Subject: Re: Autosave of panic backtraces (was Re: Getting into the debugger)
To: Brian C. Grayson <>
From: Chris G. Demetriou <>
List: tech-kern
Date: 01/17/1999 00:31:40
"Brian C. Grayson" <> writes:
>   Maybe it's just me/pilot-error, but crashdumps just haven't
> gotten along with me:
>   1.  savecore sometimes says "/dev/wd0e busy" even when dumpdev
>       is wd0b and /var/crash is wd0f.

i've seen that when the kernel being booted wasn't /netbsd...

>   2.  savecore sometimes prints some message about a completely
>       bogus device number and gives up.

that too.

>   4.  When I invoke "gdb netbsd.gdb" and use "target kcore
>       netbsd.5.core", I couldn't get a backtrace (because it
>       thought the IP was 0???).  I tried using
>       "proc curproc", but that failed trying to access 0x0
>       (invalid PDE).  Is there some crucial step I'm missing?  This
>       happened on more than one crashdump, and I still have some
>       of them lying around in /var/crash, so hints could help
>       me send better info to Bill S.

i dunnot what the deal is with this, but, in my opinion:

if the way to get a trace of the thing that cause the kernel to die
isn't the default when you get a backtrace, or how to get it isn't
painfully obvious and way over-documented, that's a bug.  please file
a PR.  8-)

Chris Demetriou - -
Disclaimer: Not speaking for NetBSD, just expressing my own opinion.