Re: Kernel Panic on FreeBSD 10.0-CURRENT #1 r253918

On Sun, Aug 4, 2013 at 12:33 PM, Sam Fourman Jr. <sfourman_at_gmail.com> wrote:

> hello list,
>
> could someone help me figure out why this machine kernel paniced?
> I have a full crashdump file if needed,
> this machine is configured as a Firewall and wifi hostap running pf in a
> small office
>
>
> here is a mailing list post to someone that had a similar problem a few
> years back
> http://lists.freebsd.org/pipermail/freebsd-bugs/2011-April/043985.html
>
> a backtrace, full dmesg, and kernel config are below
>
>
> kgdb /boot/kernel/kernel /var/crash/vmcore.0
> #4  0xffffffff80bd6027 in trap_pfault (frame=0x0, usermode=<value optimized
> out>) at /usr/src/sys/amd64/amd64/trap.c:699
> #5  0xffffffff80bd5876 in trap (frame=0xffffff80002787c0) at
> /usr/src/sys/amd64/amd64/trap.c:463
> #6  0xffffffff80bc06b2 in calltrap () at
> /usr/src/sys/amd64/amd64/exception.S:232
> #7  0xffffffff809937a8 in in6_tmpaddrtimer (arg=0xfffffe00170fc0b6) at
> /usr/src/sys/netinet6/in6_ifattach.c:935
> #8  0xffffffff8085140a in softclock_call_cc (c=0xffffffff81325210,
> cc=0xffffffff8131c700, direct=0) at /usr/src/sys/kern/kern_timeout.c:674
> #9  0xffffffff80851704 in softclock (arg=<value optimized out>) at
> /usr/src/sys/kern/kern_timeout.c:802
> #10 0xffffffff80815dc3 in intr_event_execute_handlers (p=<value optimized
> out>, ie=0xfffffe0014ab3400) at /usr/src/sys/kern/kern_intr.c:1263
> #11 0xffffffff80816716 in ithread_loop (arg=0xfffffe0014a896e0) at
> /usr/src/sys/kern/kern_intr.c:1276
> #12 0xffffffff80813b31 in fork_exit (callout=0xffffffff80816680
> <ithread_loop>, arg=0xfffffe0014a896e0, frame=0xffffff8000278a40) at
> /usr/src/sys/kern/kern_fork.c:991
> #13 0xffffffff80bc0bee in fork_trampoline () at
> /usr/src/sys/amd64/amd64/exception.S:606
> #14 0x0000000000000000 in ?? ()
> Current language:  auto; currently minimal
> (kgdb)
>
>
>

You have VIMAGE enabled in your kernel config.  I have debugged a few of
these VIMAGE problems
before.

Can you do the following for me:


(1)   Download John's gdb scripts from: http://people.freebsd.org/~jhb/gdb/
.  Put them
        in a directory such as $HOME/gdb/

(2)  Go to the kernel source directory.  You must be in this
       directory for the gdb macros to work:
          cd /usr/src

(3)  Start kgdb:
          kgdb /usr/obj/sys/conf/GENERIC/kernel.debug /var/crash/vmcore

               [ tune that line to where your kernel.debug is ]

(4)  Load the gdb scripts:
          source /home/mydir/gdb/gdb6

(5)  Go to the frame where the problem occurred.  For you it is in frame 7
in6_tmpaddrtimer.c
        (kgdb)  frame 7

(6)  Find the thread id of the active thread using this:
      (kgdb) i  thr

      There will be an asterisk besides the active thread such as:
      * 301 Thread 100515 (PID=551: at-spi-bus-launcher)
0xffffffff8094fdc6 in sched_switch (td=0xfffffe0009f43000, newtd=<value
optimized out>,

(7)  Using the thread id obtain in step 6, look up the value of curthread,
and assign it to the $td variable, for example:

      (kgdb)  lookup_thread 301 $td 0

(8)  Print out the value of $td and derference it just like any other gdb
variable

      (kgdb)  p $td

(9)  Print out the value of td->td_vnet

      (kgdb)  p $td->td_vnet


I suspect td_vnet is NULL, but please confirm.

--
Craig