Subject: kern/14792: 'cat /dev/bktr' causes kernel fault & system halt
To: None <gnats-bugs@gnats.netbsd.org>
From: None <mike.blomgren@ccnox.com>
List: netbsd-bugs
Date: 11/30/2001 04:02:07
>Number:         14792
>Category:       kern
>Synopsis:       'cat /dev/bktr' causes kernel fault & system halt
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Nov 30 04:03:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     Mike Blomgren
>Release:        1.5.1 & 1.5.2
>Organization:
CCNOX
>Environment:
NetBSD mbbsd 1.5.2 NetBSD 1.5.2 (GENERIC) #3: Sat Aug 18 23:37:05 CEST 
2001     
he@hamster.urc.uninett.no:/usr/src/sys/arch/i386/compile/GENERIC i386

>Description:
When doing a 'cat /dev/bktr', the kernel complains on a page feult, and halts all operations on the machine. A db> prompt is displayed. The only option (to my knowledge) is to reboot the machine. The error mesage displayed is (may vary slightly between machines we tested it on):

uvm_fault(0xc4674814, 0x0, 0, 1) -> 1
kernel: page fault trap, code=0
Stopped in cat at       bktropen+0x18:   movl       0(%eax,%edx,4),%edx

We discovered the problem accidentally when doing a recursive grep for a string in files on all filesystems. We nover got passed the /dev directory. Apparently the problem occurs when a process wants to open the device.

The /dev/bktr apparently has something to do with a BrookTree video device. Somthing that has not been installed in any of the machines we could reproduce the problem on. All machines were 'vanilla' PC's: AMD or Intel processor, with no extraordinary peripherals. NIC, keyboard, mouse, IDE harddisk. Soundcard in one of them.


>How-To-Repeat:
Install NetBSD 1.5.1 or 1.5.2
Login as root, or any other user
'cat /dev/bktr'
>Fix:
If I knew how, I'd uninstall the /dev/bktr device & drivers...
>Release-Note:
>Audit-Trail:
>Unformatted: