trap leads to lockdebug panic

[Sverre Froyen <sverre%viewmark.com@localhost>]

Hi,

This is just an FYI.

While investigating the (now fixed) tun deadlock, I ran into the following 
panic with a LOCKDEBUG kernel while rebooting a crashed system:

Mutex error: lockdebug_barrier: spin lock held

with the backtrace:

panic
lockdebug_abort1
rw_enter
vm_map_lock_read
uvm_fault_internal
trap
free
wapbl_replay_start
ffs_wapbl_replay_start
ffs_mountfs
ffs_mount

The trap was the result of bad call to free, which has since been fixed.  What 
strikes me as strange, however, is the trace after the trap -- eventually 
leading to a lockdebug panic.  Since the trap itself presumably is fatal, the 
rest may be irrelevant.  On the other hand, if anyone finds it interesting, 
here it is.

Regards,
Sverre