Re: Fatal trap 12: page fault while in kernel mode - current process: flowcleaner

Lawrence Stewart <lstewart_at_freebsd.org> wrote:

> Fabian Keil wrote:
> > Using:
> > 
> > FreeBSD TP51.local 8.0-BETA2 FreeBSD 8.0-BETA2 #36: Sat Aug  1 00:07:09 CEST 2009
> > fk_at_TP51.local:/usr/obj/usr/src/sys/THINKPAD  i386
> > 
> > I got the following panic:
> > 
> > fk_at_TP51 /usr/crash $kgdb /boot/kernel/kernel.symbols vmcore.6
> > GNU gdb 6.1.1 [FreeBSD]
> > Copyright 2004 Free Software Foundation, Inc.
> > GDB is free software, covered by the GNU General Public License, and you are
> > welcome to change it and/or distribute copies of it under certain conditions.
> > Type "show copying" to see the conditions.
> > There is absolutely no warranty for GDB.  Type "show warranty" for details.
> > This GDB was configured as "i386-marcel-freebsd"...
> > 
> > Unread portion of the kernel message buffer:
> > 
> > 
> > Fatal trap 12: page fault while in kernel mode
> > cpuid = 0; apic id = 00
> > fault virtual address   = 0x0
> > fault code              = supervisor read, page not present
> > instruction pointer     = 0x20:0x0
> > stack pointer           = 0x28:0xf1a2fc94
> > frame pointer           = 0x28:0xf1a2fcd8
> > 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         = 40 (flowcleaner)
> > panic: from debugger
> > cpuid = 0
> > Uptime: 2m1s
> > Physical memory: 998 MB
> > Dumping 144 MB: 129 113 97 81 65 49 33 17 1
> > 
> > Reading symbols from /boot/kernel/unionfs.ko...Reading symbols from /boot/kernel/unionfs.ko.symbols...done.
> > done.
> > [...]
> > Loaded symbols for /boot/kernel/fdescfs.ko
> > #0  doadump () at pcpu.h:246
> > 246     pcpu.h: No such file or directory.
> >         in pcpu.h
> > (kgdb) where
> > #0  doadump () at pcpu.h:246
> > #1  0xc0678e66 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:419
> > #2  0xc06790a2 in panic (fmt=Variable "fmt" is not available.
> > ) at /usr/src/sys/kern/kern_shutdown.c:575
> > #3  0xc04f2e57 in db_panic (addr=Could not find the frame base for "db_panic".
> > ) at /usr/src/sys/ddb/db_command.c:478
> > #4  0xc04f33e1 in db_command (last_cmdp=0xc0a1f31c, cmd_table=0x0, dopager=1) at /usr/src/sys/ddb/db_command.c:445
> > #5  0xc04f353a in db_command_loop () at /usr/src/sys/ddb/db_command.c:498
> > #6  0xc04f532d in db_trap (type=12, code=0) at /usr/src/sys/ddb/db_main.c:229
> > #7  0xc06a33c6 in kdb_trap (type=12, code=0, tf=0xf1a2fc54) at /usr/src/sys/kern/subr_kdb.c:534
> > #8  0xc0913a8f in trap_fatal (frame=0xf1a2fc54, eva=0) at /usr/src/sys/i386/i386/trap.c:924
> > #9  0xc0913cc3 in trap_pfault (frame=0xf1a2fc54, usermode=0, eva=0) at /usr/src/sys/i386/i386/trap.c:846
> > #10 0xc091469a in trap (frame=0xf1a2fc54) at /usr/src/sys/i386/i386/trap.c:528
> > #11 0xc08f83bb in calltrap () at /usr/src/sys/i386/i386/exception.s:165
> > #12 0x00000000 in ?? ()
> > Previous frame inner to this frame (corrupt stack?)
> > 
> > The backtrace in ddb mentioned several flow* functions,
> > but unfortunately it doesn't seem to have survived the
> > dump.
> > 
> > The problem occurred after booting the system with the rc.conf line:
> >   ifconfig_wlan0="inet 192.168.178.49 -wme"
> > changing it to:
> >   ifconfig_wlan0="inet 192.168.178.49 ssid [...] wepkey 1:[0x...] deftxkey 1 wepmode on chanlist 7 -wme"
> > running:
> >   /etc/rc.d/netif restart
> > followed by:
> >   ifconfig wlan0
> > which showed that wlan0 got associated.
> > The panic happened less than a second later.
> > 
> > The system is an IBM ThinkPad R51 with iwi0 as wlandev.
> > em0 was configured and up but unconnected.

> I can reliably trigger a flowcleaner panic as well on my Toshiba R600 
> laptop with a rum based WIFI dongle (D-Link DWA-110). I only get it on 
> teardown/detach though. Kip is aware of the issue and will hopefully 
> have a patch for us at some point.

Thanks for the information.

Did you try disabling options FLOWTABLE already? It doesn't
strike me as particularly useful on a laptop anyway.

Fabian