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Date: Thu, 13 Nov 1997 11:51:16 -0800 (PST)
From: Doug White <dwhite@gdi.uoregon.edu>
Reply-To: Doug White <dwhite@resnet.uoregon.edu>
To: Jason Wells <jcwells@u.washington.edu>
cc: freebsd-questions@FreeBSD.ORG
Subject: Re: more info regarding umount/panic
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On Wed, 12 Nov 1997, Jason Wells wrote:

> Upon trying to umount ANY filesystem I have been receiving a panic. Here is
> the output to the console. If it looks kinda funny it is because it is hand
> written.
> 
> Fatal trap 12:	page fault while in kernel mode
> 
> fault virtual address	=0x18
> fault code			=supervisor read, page not present
> instruction pointer	=0x8:0xf012e49c
> stack pointer		=0x10:0xefbffef8
> frame pointer		=0x10:0xefbfff58
> code segment		=base 0x0, limit 0xfffff, type 0x1b
> 				=DPL 0, pres 1, def32, gran 1
> processor flags		=interrupt enabled, resume, IOPL = 8
> current process		=150 (umount)
> interupt mask		=
> panic: page fault
> 
> There is an earlier related post with a savecore/dump subject heading.

Someone is scribbling all over the kernel stack.  Note the virtual address
is really low and 0xefb... is in the kernel stack area.

What devices do you have installed?  I could get a quickcam to do this
when I exited X.  Turned out my MB spits out random IRQ 7's and i
intelligently stuck the qcam on it, so when it kicked one out the driver
took a picture into space.

Doug White                              | University of Oregon  
Internet:  dwhite@resnet.uoregon.edu    | Residence Networking Assistant
http://gladstone.uoregon.edu/~dwhite    | Computer Science Major