Kernel panic within dummynet-code(?)

Sebastian Inacker inacker at
Thu Feb 23 02:07:07 PST 2006

Hello Networkers.

I got a kernel panic on FreeBSD 6.0-RELEASE, which is probably caused
by a not initialised pointer "p = (void *) 0x0" within the

I analysed the crash dump and got

  (kgdb) f 9
  #9  0xc06d3670 in dummynet (unused=0x0) at ../../../netinet/ip_dummynet.c:785

  (kgdb) i loc
  p = (void *) 0x0
  h = (struct dn_heap *) 0x4
  heaps = {0xc093cf40, 0xc093cf60, 0xc093cf50}
  i = 22
  pe = (struct dn_pipe *) 0x4

(see backtrack[1] of the crash dump).

Some frames before I do have problems with subr_turnstile.c and
kern_mutex.c, which could be caused by a problem in dummynet - but I'm
not sure.

The machine does use dummynet (with DUMMYNET and HZ=1000) for
bandwidth management, but the problem - if it is within dummynet -
have to be a special case, because it crashes not as regulary as it
would do in other cases.

I'd be glad, if someone can help me.
I would be glad also if I could help to fix a maybe existing bug.

[1] To save bandwidth: The complete backtrack of that kernel panic is on
<URL:>, if that's
helpfull. Just ask for more informations if needed.

More information about the freebsd-net mailing list