FreeBSD 6.1 Tor issues (Once More, with Feeling)

[Robert Watson]

On Sun, 2 Jul 2006, Fabian Keil wrote:

>> I'm very interested in tracking down this problem, but have had a lot of 
>> trouble getting reliable reports of problems -- i.e., ones where I could 
>> get any debugging information.  I had a similar conversation on these lines 
>> yeterday with Roger (Tor author) here at the WEIS conference.  If this is 
>> easily reproduceable, I would like you to do the following:
>
>> - Does the hang occur?  If so, use a serial break to get into DDB, see the 
>> above.
>
> I previously had the serial console misconfigured and I'm still not sure if 
> the settings are correct now.
>
> So far I put "BOOT_COMCONSOLE_SPEED=57600" in /etc/make.conf, "options 
> CONSPEED=57600" in the kernel and "console=comconsole" in /boot/loader.conf. 
> Kernel and bootblock were recompiled and reinstalled. /boot.config contains 
> the line: "-D -h -S57600" (speed setting through make.conf didn't work).

I don't use alternative console speeds, so can't comment on the specifics of 
the above, but the output below looks right.

> The boot process now starts with:
>
> PXELINUX 3.11 2005-09-02  Copyright (C) 1994-2005 H. Peter Anvin
> Booting from local disk...
>
> 1   Linux
> 2   FreeBSD
> 3   FreeBSD
>
> Default: 2
>
> /boot.config: -DConsoles: internal video/keyboard  serial port
> BIOS drive C: is disk0
> BIOS 639kB/523200kB available memory
>
> FreeBSD/i386 bootstrap loader, Revision 1.1
> [...]
>
> After manually triggering a test panic through debug.kdb.enter I could enter 
> ddb and everything seemed to be working.
>
> However today I got another hang and couldn't enter the debugger by sending 
> BREAK. It is the same BREAK ssh sends with ~B, right?
>
> Even after rebooting, sending break didn't trigger a panic, so either I'm 
> sending the wrong BREAK, or my console settings are still messed up. Any 
> ideas?

What serial software are you using to reach the console?  Do you have options 
BREAK_TO_DEBUGGER compiled into your kernel?  The delivery mechanism for the 
break will depend on the software you're using...

Robert N M Watson
Computer Laboratory
University of Cambridge