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Date: Wed, 15 Dec 2010 13:47:23 +0200
From: Andriy Gapon <avg@freebsd.org>
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Cc: freebsd-stable@freebsd.org
Subject: Re: How to debug a double fault? (Re: Could MSGBUF_SIZE be made a
 loader tunable?)
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on 15/12/2010 12:37 perryh@pluto.rain.com said the following:
> Fatal double fault:
> eip = 0xc07feb98
> esp = 0xc101e000
> ebp = 0xc101e004
> cpuid = 0; apic id = 00
> panic: double fault
> cpuid = 0
> 
> How do I go about tracking this down?

Do you have the standard debugging options in your kernel?
http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html

BTW, are you sure that you correctly placed initialization of msgbufsize ?
I am not saying that you haven't, just make sure that it is set before its first
use.

-- 
Andriy Gapon