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Date: Wed, 3 May 1995 12:40:01 -0700
Message-Id: <199505031940.MAA12000@freefall.cdrom.com>
From: System Operator <operator@alano.diatel.upm.es>
Reply-To: System Operator <operator@alano.diatel.upm.es>
To: freebsd-bugs
Subject: kern/380: kernel panic related to DC21040 network card
In-Reply-To: Your message of Wed, 3 May 1995 21:36:21 +0200
	<199505031936.VAA00555@alano.diatel.upm.es>
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>Number:         380
>Category:       kern
>Synopsis:       kernel panic related to DC21040 network card
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs (FreeBSD bugs mailing list)
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed May  3 12:40:00 1995
>Originator:     Javier Martin Rueda
>Organization:
>Release:        FreeBSD 2.1.0-Development i386
>Environment:
950412-SNAP

	

>Description:

I have a SMC 8432BT ethernet card. The card seems to work ok with telnet, ftp,
etc. At the moment it doesn't have too much of a load, as usually there is only
one or two users connected through telnet, no NFS, no FTP, etc.

Today, I executed "ls -lR /" from a telnet session (without redirecting the output,
or anything like that) and after a bunch of files were listed, the following
message appeared (I copied it by hand) on the console and there was a panic:

de0: tulip_txsegment: extremely fragmented packed encountered (30 segments)
panic: m_copydata
Fatal trap 12: page fault while in kernel mode
fault virtual address = 0x18
fault code = supervisor read, page not present
instruction pointer = 0x8:0xf011efcb
code segment = base 0x0, limit 0xfffff, type = 0x1b
             = DPL 0, pres 1, def32 1, gran 1
processor eflags = interrupt enabled, resume, IOPL=0
current process = Idle
interrupt mask = net bio
panic: page fault
dumping to dev 401, offset 98304
dump 16

I must say that there is a machine in our network that from time to time puts
giant packets into the ethernet (around 7.5 Kb). FreeBSD doesn't seem to be
affected by them, but I don't know if thay may have any influence in the
above panic. The panic did not occurr when one of those was received, though.

After executing "nm /kernel | sort", the area surrounding the fault address is:

f011ece4 T _bread
f011ed94 T _breadn
f011ef50 T _bwrite
f011f034 T _vn_bwrite
f011f060 T _bdwrite

So, it seems the function that was executing was bwrite, if I'm right.

By the way, as you may notice in the panic message above, the kernel was not
able to dump a memory image. I have 16 Mb of RAM and 64 Mb in a single swap
partition. The controller is a Buslogic 946C. The SCSI light stayed on.

	

>How-To-Repeat:

I couldn't repeat it.

	

>Fix:
	Not known, sorry.

	

>Audit-Trail:
>Unformatted: