Bug 98154

Summary:	6-STABLE crashes when being online via modem (Fujitsu Siemens Amilo A notebook)
Product:	Base System	Reporter:	Hans-Michael Gerhards <hm-gerhards>
Component:	i386	Assignee:	freebsd-i386 (Nobody) <i386>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	6.1-STABLE
Hardware:	Any
OS:	Any

Description Hans-Michael Gerhards 2006-05-30 15:50:19 UTC

Sometimes when being connected to the internet via serial modem and kppp
dial-up connection the system completly locks up (and reboots after some
seconds to minutes).

"kgdb kernel.debug /var/crash/vmcore.2" on my system gives the following
output:

[GDB will not be able to debug user-mode threads:
/usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
GNU gdb 6.1.1 [FreeBSD]
(...)
Unread portion of the kernel message buffer:


Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x29
fault code              = supervisor write, page not present
instruction pointer     = 0x20:0xc06ad6a6
stack pointer           = 0x28:0xd992f9d0
frame pointer           = 0x28:0xd992fa00
code segment            = base rx0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 793 (opera)
trap number             = 12
panic: page fault
Uptime: 19m31s
Dumping 478 MB (2 chunks)
  chunk 0: 1MB (159 pages) ... ok
  chunk 1: 478MB (122352 pages) 462 446 430 414 398 382 366 350 334 318
302 286 270 254 238 222 206 190 174 158 142 126 110 94 (CTRL-C to abort)
(CTRL-C to abort)  78 (CTRL-C to abort)  (CTRL-C to abort)  (CTRL-C to
abort)  62 46 30 14

#0  doadump () at pcpu.h:165
165             __asm __volatile("movl %%fs:0,%0" : "=r" (td));
(kgdb) quit

How-To-Repeat: 
Establishing an dial-up internet access via modem and kppp and browsing
around some internet pages. After some time (the exact time is
unpredictable, sometimes only minutes, sometimes even not within some
hours) the system completly locks up and reboots.

Comment 1 jvender 2007-02-06 22:05:31 UTC

I appear to be experiencing the same problem as reported in this bug report. 
I've posted what I could starting at:

http://lists.freebsd.org/pipermail/freebsd-questions/2007-January/140919.html

Comment 2 Hajimu UMEMOTO freebsd_committer

2007-02-08 19:27:31 UTC

Hi,

Put debug.mpsafenet=0 into your /boot/loader.conf.
I believe it is for workaround.

-- 
Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume@mahoroba.org  ume@{,jp.}FreeBSD.org
http://www.imasy.org/~ume/

Comment 3 jvender 2007-02-10 20:05:05 UTC

Well, I've set the tunable as suggested, configured KPPP and am using it now. 
So far, no problem, but I haven't been online for long either, so time will 
tell if thats the problem. I came across this which states that if you are 
using pppd, then you need to set the tunable to 0, if I read it correctly.

http://unix.derkeiler.com/Mailing-Lists/FreeBSD/current/2004-08/2745.html

This all makes me wonder, what is the advantage to having the debug.mpsafenet 
set to 1 as default, anyway, if the computer only has a single processor? 
Shouldn't the installer be smart enough to detect if the computer is single 
or multiprocessor, and set the tunable accordingly, at least until ALL of the 
network features are made MPSAFE so that it is no longer an issue? And, when 
installing FreeBSD 6.2, the kernel that booted from the install CD was 
GENERIC, but after the installation, the bootup showed that the kernel being 
used was SMP. Being that my computer is a single processor, shouldn't it 
default to the GENERIC kernel after installation, unless I request otherwise?

Thanks,
Joe

Comment 4 jvender 2007-02-12 00:05:37 UTC

Well, I'm sorry to say that this suggested workaround didn't fix the 
spontaneous reboot issue for me, although I was able to spend several hours 
connected while using KPPP before problems. In the dialup session in which 
the problem had occurred, I'd been online for about an hour which was spent 
downloading latest ports snapshot via portsnap. I left the computer after 
about an hour of downloading, and when I returned a while later, there it sat 
staring at me with a login prompt. It had spontaneously rebooted! I was using 
KPPP when this happened, so also using pppd.

Joe

Comment 5 Remko Lodder freebsd_committer

2010-07-14 07:03:39 UTC

State Changed
From-To: open->feedback

Hello is this still a problem on recent versions of FreeBSD?

Comment 6 Remko Lodder freebsd_committer

2011-10-12 07:15:57 UTC

State Changed
From-To: feedback->closed

Feedback timeout