From mishka@victor.terabyte.com.ua  Tue Jan 29 13:43:15 2002
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Date: Tue, 29 Jan 2002 23:42:28 +0200 (EET)
From: Mishka <mishka@terabyte.com.ua>
To: FreeBSD-gnats-submit@freebsd.org
Cc: <mishka@batraq.anything3d.com>
Subject: crash system wnen kill pppd with reattached umodem
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>Number:         34422
>Category:       i386
>Synopsis:       crash system wnen kill pppd with reattached umodem
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          closed
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Jan 29 13:50:01 PST 2002
>Closed-Date:    Wed Aug 21 16:17:01 PDT 2002
>Last-Modified:  Wed Aug 21 16:17:01 PDT 2002
>Originator:     Mishka
>Release:        FreeBSD 4.5-RC i386
>Organization:
Terabyte ACS
>Environment:
System: FreeBSD victor.terabyte.com.ua 4.5-RC FreeBSD 4.5-RC #2: Sun Jan 27 18:28:25 EET 2002 mishka@victor.terabyte.com.ua:/usr/src/sys/compile/VMUNIX i386 (updated 27/01/2002, 18:00 EET)

Hardware: 3Com OfficeConnect 56K Business Modem attached to Intel USB
	onto Asus P2B-LS systemboard / ippII-350 /
	Kingston ValueRam KVR133X64C3/256 /
	Seagate SCSI-LVD
	(usbdevs output, usbd runned also):
	addr 1: UHCI root hub, Intel
	 addr 2: 3Com OfficeConnect Analog Modem, 3Com Inc.

>Description:

Dear Sirs!!!

Some situation have discouraged me last few days.

Our server have runned pppd, attached to /dev/umodem0.
When i switch modem power off and then turn it on or just detach then
attach USB cord, pppd loss /dev/umodem0 descriptor (i think).
Next when i try kill pppd process by "kill 179" (real process number) i got
followed trap messages and server ask me for shutdown:

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Fatal trap 12: page fault while in kernel mode
fault virtual address	= 0x4
fault code		= supervisor read, page not present
instructin pointer	= 0x8:0xc015411b
stack pointer		= 0x10:0xc8245d18
frame pointer		= 0x10:0xc8245d18
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		= 179 (pppd)
interrupt mask		= tty
trap number		= 12
panic: page fault

syncing disks... 33 1
done
Uptime: 10m11s
Automatic reboot in 15 seconds - press any key on the console to abort
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

However, when i do this expirement with always attached and turned on modem
all works perfectly - no any system panic appears.

Of course I can't run pppd with detached umodem0 port.

Unfortunately i can't test this situation on other hardware/OS machine.
Any ideas?


>How-To-Repeat:

-- 
BR, Mishka.
<mishka@terabyte.com.ua>
<mishka@batraq.anything3d.com>

>Fix:

>Release-Note:
>Audit-Trail:

From: David Malone <dwmalone@maths.tcd.ie>
To: Mishka <mishka@terabyte.com.ua>
Cc: FreeBSD-gnats-submit@freebsd.org, mishka@batraq.anything3d.com
Subject: Re: i386/34422: crash system wnen kill pppd with reattached umodem
Date: Tue, 29 Jan 2002 22:25:32 +0000

 On Tue, Jan 29, 2002 at 11:42:28PM +0200, Mishka wrote:
 > Our server have runned pppd, attached to /dev/umodem0.
 > When i switch modem power off and then turn it on or just detach then
 > attach USB cord, pppd loss /dev/umodem0 descriptor (i think).
 > Next when i try kill pppd process by "kill 179" (real process number) i got
 > followed trap messages and server ask me for shutdown:
 
 There have been a few bugs in the USB code like this and they are
 often quite easy to fix if we can get good debugging info. If you
 can get a kernel trace back as described at:
 
 http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/advanced.html#KERNEL-PANIC-TROUBLESHOOTING
 
 then there is a good chance this problem can be fixed.
 
 	David.
State-Changed-From-To: open->feedback 
State-Changed-By: sheldonh 
State-Changed-When: Wed Jan 30 01:23:28 PST 2002 
State-Changed-Why:  
Please copy your feedback to <bug-followup@freebsd.org>, using the 
subject line of this message. 

http://www.FreeBSD.org/cgi/query-pr.cgi?pr=34422 
State-Changed-From-To: feedback->closed 
State-Changed-By: keramida 
State-Changed-When: Wed Aug 21 16:16:40 PDT 2002 
State-Changed-Why:  
Feedback timeout. 

http://www.freebsd.org/cgi/query-pr.cgi?pr=34422 
>Unformatted:
