kern/52198: rw_exit panic

[martin%NetBSD.org@localhost]

>Number:         52198
>Category:       kern
>Synopsis:       rw_exit panic
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Apr 27 18:00:00 +0000 2017
>Originator:     Martin Husemann
>Release:        NetBSD 7.99.70
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD whoever-brings-the-night.aprisoft.de 7.99.70 NetBSD 7.99.70 (WHOEVER) #119: Mon Apr 24 09:23:46 CEST 2017 martin%martins.aprisoft.de@localhost:/ssd/src/sys/arch/sparc64/compile/WHOEVER sparc64
Architecture: sparc64
Machine: sparc64
>Description:

When starting X with a -current kernel, I get a reader/writer lock error
in the Xorg process:

Starting xdm.
Reader / writer lock error: rw_vector_exit,444: no shared locks held by LWP

lock address : 0x0000000109cb5b40 type     :     sleep/adaptive
initialized  : 0x000000000153553c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
current cpu  :                  1 last held:                  1
current lwp  : 0x0000000109d6adc0 last held: 000000000000000000
last locked  : 0x00000000015d87ac unlocked*: 0x00000000015d8850
owner/count  : 000000000000000000 flags    : 000000000000000000

Turnstile chain at 0x1c9a540.
=> No active turnstile for this lock.

panic: LOCKDEBUG: Reader / writer lock error: rw_vector_exit,444: no shared locks held by LWP

Backtrace is:

netbsd:rw_exit+0xf0
netbsd:genfs_unlock+0x10
netbsd:VOP_UNLOCK+0x4c
netbsd:vput+0x4
netbsd:do_sys_unlinkat+0x1f0
netbsd:syscall+0x520

>How-To-Repeat:
s/a

>Fix:
n/a