mpd5/Netgraph issues after upgrading to 7.4

[Gleb Smirnoff]

On Sat, Jul 07, 2012 at 10:26:46AM +0200, Przemyslaw Frasunek wrote:
P> > After reenabling IPv6, the crash occurred within 6 hours. This time, crashdump
P> > was properly saved (thanks to patch suggested by Eugene).
P> 
P> My PPPoE BRAS was stable for 17 days. This morning, it crashed in another way:
P> 
P> current process         = 2762 (mpd5)
P> trap number             = 9
P> panic: general protection fault
P> cpuid = 5
P> KDB: stack backtrace:
P> #0 0xffffffff803a04a6 at kdb_backtrace+0x66
P> #1 0xffffffff8036dfde at panic+0x1ce
P> #2 0xffffffff80503300 at trap_fatal+0x290
P> #3 0xffffffff80503851 at trap+0x111
P> #4 0xffffffff804ea5d4 at calltrap+0x8
P> #5 0xffffffff8041d314 at lltable_prefix_free+0x74
P> #6 0xffffffff8044c014 at in_ifscrub+0x2c4
P> #7 0xffffffff8044d3f3 at in_control+0x793
P> #8 0xffffffff80418d2d at ifioctl+0xccd
P> #9 0xffffffff803b6842 at kern_ioctl+0x92
P> #10 0xffffffff803b6aa0 at ioctl+0xf0
P> #11 0xffffffff80502ab2 at amd64_syscall+0x302
P> #12 0xffffffff804ea8cc at Xfast_syscall+0xfc
P> Uptime: 17d7h18m38s

This looks very much related to a known race in ARP code.

See this email and related thread:

http://lists.freebsd.org/pipermail/freebsd-net/2012-March/031865.html

Ryan didn't check in any patches since, and I failed to follow on this
problem due to ENOTIME.

I've added Ryan to Cc. Ryan, what's the status of the problem at your
side? Did you come to any solution?

-- 
Totus tuus, Glebius.