kern/46050: Reader/writer lock error: rw_vector_enter: locking against myself

[netbsd%eq.cz@localhost]

>Number:         46050
>Category:       kern
>Synopsis:       Reader/writer lock error:  rw_vector_enter: locking against 
>myself
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Feb 19 03:45:00 +0000 2012
>Originator:     rudolf
>Release:        netbsd-6
>Organization:
>Environment:
NetBSD 6.0 i386 MONOLITHIC with PAE from 2012/02/16 3:26 UTC, on netbsd-5 
userland
>Description:
Dual-core CPU, 8 GB RAM, i386, PAE.
mount:
/dev/wd0a on / type ffs (local)
mfs:198 on /tmp type mfs (synchronous, local)
kernfs on /kern type kernfs (local)
ptyfs on /dev/pts type ptyfs (local)
procfs on /usr/pkg/emul/linux/proc type procfs (local)

The panic occured when the daily cron script was running and I did some 
standard desktop work.

Reader/writer lock error:  rw_vector_enter: locking against myself
lock address: 0xcbe11e6c
current cpu: 0
lwp: 0xcbdec800
owner/count: 0xcbdec800 flags: 0x4
panic: lock error
trap type 1 code 0 eip c02d21a4 cs8 eflags 286 cr2 3fdc ilevel 0
stopped in pid 3592.1 (sh) at netbsd: breakpoint+0x4: popl %ebp

> bt
breakpoint +0x4
cpu_Debugger +0xb
vpanic +0x1cc
vpanic
lockdebug_abort +0x87
rw_abort +0x30
rw_vector_enter +0x19c
vm_map_lock_read +0x5d
uvmfault_lookup
uvm_fault_check +0x20
uvm_fault_internal +0x16c
trap() +0x852
pmap_create +0x17c
uvmspace_init +0x5a
uvmspace_alloc +0x46
uvmspace_fork 0x30
uvm_proc_fork +0x3e
fork1
sys_fork
>How-To-Repeat:

>Fix: