lock order reversal:
 1st 0xfffffe00010fa068 em0:tx(0):callo (em0:tx(0):callo) @ /usr/home/sbruno/networking/sys/kern/kern_mutex.c:182
 2nd 0xfffff8000534ed48 em0 (iflib ctx lock) @ /usr/home/sbruno/networking/sys/net/iflib.c:2118
stack backtrace:
#0 0xffffffff80a7aff0 at witness_debugger+0x70
#1 0xffffffff80a7aee3 at witness_checkorder+0xe23
#2 0xffffffff809f98f3 at __mtx_lock_flags+0x93
#3 0xffffffff80b233e9 at iflib_timer+0x149
#4 0xffffffff80a31368 at softclock_call_cc+0x158
#5 0xffffffff80a3174c at softclock+0x7c
#6 0xffffffff809de9e9 at intr_event_execute_handlers+0x99
#7 0xffffffff809df086 at ithread_loop+0xb6
#8 0xffffffff809dc0d4 at fork_exit+0x84
#9 0xffffffff80e7db5e at fork_trampoline+0xe
em0: TX(0) desc avail = 41, pidx = 630