kern/38415: sysctl panic: locking against myself

[ws%tools.de@localhost]

>Number:         38415
>Category:       kern
>Synopsis:       sysctl panic: locking against myself
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Apr 12 14:10:00 +0000 2008
>Originator:     Wolfgang Solfrank
>Release:        NetBSD 4.99.58
>Organization:
        Tools GmbH
>Environment:
System: NetBSD sdsl1.tools.de 4.99.58 NetBSD 4.99.58 (sdsl1) #0: Thu Apr 10 
18:40:23 MEST 2008 
ws%sdsl1.tools.de@localhost:/src/obj/sys/arch/i386/compile/sdsl1 i386
Architecture: i386
Machine: i386
>Description:

This box crashes repeatedly with the "locking against myself" panic.
The backtrace is always the same:

(gdb) where
#0  cpu_reboot (howto=256, bootstr=0x0)
    at /src/src/sys/arch/i386/i386/machdep.c:884
#1  0xc05796f8 in panic (fmt=0xc0a07860 "LOCKDEBUG")
    at /src/src/sys/kern/subr_prf.c:260
#2  0xc0572f46 in lockdebug_abort1 (ld=0xc0d2cb60, lk=0xc0d35a40, 
    func=0xc0a0757f "lockdebug_wantlock", 
    msg=0xc0a075c0 "locking against myself", dopanic=true)
    at /src/src/sys/kern/subr_lockdebug.c:794
#3  0xc05725b1 in lockdebug_wantlock (lock=0xc0d0dae4, where=3226301243, 
    shared=0) at /src/src/sys/kern/subr_lockdebug.c:509
#4  0xc054f980 in rw_vector_enter (rw=0xc0d0dae4, op=RW_WRITER)
    at /src/src/sys/kern/kern_rwlock.c:266
#5  0xc04d733b in vm_map_lock (map=0xc0d0dae0)
    at /src/src/sys/uvm/uvm_map.c:531
#6  0xc04dd6f2 in uvm_kmapent_free (entry=0xcf28c06c)
    at /src/src/sys/uvm/uvm_map.c:4597
#7  0xc04d796f in uvm_mapent_free (me=0xcf28c06c)
    at /src/src/sys/uvm/uvm_map.c:733
#8  0xc04da5b7 in uvm_map_replace (map=0xc0d0dae0, start=3475865600, 
    end=3475869696, newents=0xdd853644, nnewents=1)
    at /src/src/sys/uvm/uvm_map.c:2540
#9  0xc04dae28 in uvm_map_extract (srcmap=0xcdadb55c, start=3217027072, 
    len=4096, dstmap=0xc0d0dae0, dstaddrp=0xcf94ab18, flags=14)
    at /src/src/sys/uvm/uvm_map.c:2854
#10 0xc04d2bc3 in uvm_io (map=0xcdadb55c, uio=0xcf94ab8c)
    at /src/src/sys/uvm/uvm_io.c:108
#11 0xc0524fe2 in sysctl_kern_proc_args (name=0xcf94ac9c, namelen=2, 
    oldp=0xbb915080, oldlenp=0xcf94ac90, newp=0x0, newlen=0, oname=0xcf94ac94, 
    l=0xcf9232e0, rnode=0xc4097f60) at /src/src/sys/kern/init_sysctl.c:2486
#12 0xc055aff7 in sysctl_dispatch (name=0xcf94ac94, namelen=4, 
    oldp=0xbb915080, oldlenp=0xcf94ac90, newp=0x0, newlen=0, oname=0xcf94ac94, 
    l=0xcf9232e0, rnode=0xc4097f60) at /src/src/sys/kern/kern_sysctl.c:446
#13 0xc055ac4a in sys___sysctl (l=0xcf9232e0, uap=0xcf94ad04, 
    retval=0xcf94acfc) at /src/src/sys/kern/kern_sysctl.c:302
#14 0xc065d7b1 in syscall (frame=0xcf94ad48)
    at /src/src/sys/arch/i386/i386/syscall.c:112
#15 0xc0100574 in syscall1 ()
(gdb) 

The process panicing is always ps.

The machine in question is dual core, and the kernel is generated
with LOCKDEBUG and DIAGNOSTIC.

Let me know if you need additional information, as I've got some crash
dump(s) that I can analyze.

>How-To-Repeat:
        Repeated calls to "ps"?

>Fix:
        unknown