Recent 6.0_BETA crash

[Aleksey Cheusov <cheusov%tut.by@localhost>]

I few minutes ago I updated the kernel and modules on my 6.0_BETA
to the latest netbsd-6 sources and enabled debugging kernel options.

   options        DEBUG           # expensive debugging checks/support
   makeoptions    DEBUG="-g"      # compile full symbol table

Userlevel was not updated.
After login in xdm the system crashed.
    at /srv/src_netbsd_current/sys/arch/x86/x86/pmap.c:3326

    3326            KASSERT(uvm_page_locked_p(pg));

Stacktrace is below. Any clue?

#0  0xc05c4a73 in maybe_dump (howto=260) at 
/srv/src_netbsd_current/sys/arch/i386/i386/machdep.c:878
878                     dumpsys();
#0  0xc05c4a73 in maybe_dump (howto=260) at 
/srv/src_netbsd_current/sys/arch/i386/i386/machdep.c:878
#1  cpu_reboot (howto=260, bootstr=0x0) at 
/srv/src_netbsd_current/sys/arch/i386/i386/machdep.c:903
#2  0xc07c1c8a in vpanic (fmt=0xc0c2096b "trap", ap=0xdbdcc864 
"\004\311ÜÛ\004\311ÜÛ`T\214À\b") at 
/srv/src_netbsd_current/sys/kern/subr_prf.c:308
#3  0xc07c1d2f in panic (fmt=0xc0c2096b "trap") at 
/srv/src_netbsd_current/sys/kern/subr_prf.c:205
#4  0xc081e8d0 in trap (frame=0xdbdcc904) at 
/srv/src_netbsd_current/sys/arch/i386/i386/trap.c:396
#5  0xc010d08f in ?? ()
#6  0xc0698651 in pmap_remove_pte (pmap=<optimized out>, ptp=0xc2fab258, 
pte=<optimized out>, va=3141660672, pv_tofree=0xdbdcc9f4) at 
/srv/src_netbsd_current/sys/arch/x86/x86/pmap.c:3326
#7  0xc069c20a in pmap_remove_ptes (pv_tofree=0xdbdcc9f4, endva=<optimized 
out>, startva=3141660672, ptpva=<optimized out>, ptp=<optimized out>, 
pmap=<optimized out>) at /srv/src_netbsd_current/sys/arch/x86/x86/pmap.c:3252
#8  pmap_remove (pmap=0xc381eac8, sva=3141660672, eva=3141668864) at 
/srv/src_netbsd_current/sys/arch/x86/x86/pmap.c:3444
#9  0xc08be529 in uvm_unmap_remove (map=0xc381d6c0, start=<optimized out>, 
end=3217031168, entry_list=0xdbdccac0, flags=0) at 
/srv/src_netbsd_current/sys/uvm/uvm_map.c:2262
#10 0xc08be8af in uvmspace_free (vm=0xc381d6c0) at 
/srv/src_netbsd_current/sys/uvm/uvm_map.c:4183
#11 0xc0542647 in exit1 (l=0xc48a9d40, rv=134) at 
/srv/src_netbsd_current/sys/kern/kern_exit.c:327
#12 0xc05615d8 in sigexit (l=0xc48a9d40, signo=6) at 
/srv/src_netbsd_current/sys/kern/kern_sig.c:2235
#13 0xc0561938 in postsig (signo=6) at 
/srv/src_netbsd_current/sys/kern/kern_sig.c:2032
#14 0xc054accd in lwp_userret (l=0xc48a9d40) at 
/srv/src_netbsd_current/sys/kern/kern_lwp.c:1403
#15 0xc07e65d3 in mi_userret (l=0xc48a9d40) at 
/srv/src_netbsd_current/sys/sys/userret.h:96
#16 userret (l=0xc48a9d40) at ./machine/userret.h:78
#17 syscall (frame=0xdbdccd48) at 
/srv/src_netbsd_current/sys/arch/x86/x86/syscall.c:208
#18 0xc01005d6 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)