Re: kern/38732: proplib locking error

[Christoph Egger <Christoph_Egger%gmx.de@localhost>]

oster%netbsd.org@localhost wrote:
> > Number:         38732
> > Category:       kern
> > Synopsis:       proplib has locking issues
> > Confidential:   no
> > Severity:       critical
> > Priority:       high
> > Responsible:    kern-bug-people
> > State:          open
> > Class:          sw-bug
> > Submitter-Id:   net
> > Arrival-Date:   Fri May 23 18:40:00 +0000 2008
> > Originator:     oster%netbsd.org@localhost
> > Release:        NetBSD 4.99.63
> > Organization:
> > Environment:
> System: NetBSD hapi 4.99.63 NetBSD 4.99.63 (GENERICLD) #0: Thu May 22 15:58:15 
> CST 2008  root@hapi:/u1/builds/build203/src/sys/arch/amd64/compile/GENERICLD 
> amd64
> Architecture: amd64
> Machine: amd64
> > Description:
> 	proplib seems to have some locking issues... 
>
> Reader / writer lock error: lockdebug_wantlock: locking against myself
>  
> lock address : 0xffff800064a11fa0 type     :     sleep/adaptive
> shared holds :                  1 exclusive:                  0
> shares wanted:                  1 exclusive:                  0
> current cpu  :                  3 last held:                  3
> current lwp  : 0xffff80007568b800 last held: 0xffff80007568b800
> last locked  : 0xffffffff8071c607 unlocked : 0xffffffff8071c645
> initialized  : 0xffffffff8071d0af
> owner/count  : 0x0000000000000010 flags    : 0x0000000000000008
>  
> Turnstile chain at 0xffffffff80c6ee00.
> => No active turnstile for this lock.
>  
> panic: LOCKDEBUG
> Stopped in pid 2085.1 (envstat) at      netbsd:breakpoint+0x5:  leave
> db{3}> tr
> breakpoint() at netbsd:breakpoint+0x5
> panic() at netbsd:panic+0x260
> lockdebug_abort1() at netbsd:lockdebug_abort1+0xd3
> rw_vector_enter() at netbsd:rw_vector_enter+0x2f1
> prop_dictionary_iterator() at netbsd:prop_dictionary_iterator+0x77
> _prop_dictionary_externalize() at netbsd:_prop_dictionary_externalize+0xba
> prop_dictionary_externalize() at netbsd:prop_dictionary_externalize+0x40
> _prop_object_copyout_ioctl() at netbsd:_prop_object_copyout_ioctl+0x12e
> sysmonioctl_envsys() at netbsd:sysmonioctl_envsys+0x4da
> VOP_IOCTL() at netbsd:VOP_IOCTL+0x6b
> vn_ioctl() at netbsd:vn_ioctl+0x6d
> sys_ioctl() at netbsd:sys_ioctl+0x134
> syscall() at netbsd:syscall+0x9a
> db{3}> 
>
>
>
> > How-To-Repeat:
>         run GENERIC+LOCKDEBUG/DEBUG/DIAGNOSTIC kernel on amd64
>         do something like 'envstat -d mfi0'
>         *boom*
>
>         Additional details available upon request.
>
> > Fix:

See http://mail-index.netbsd.org/port-amd64/2008/05/19/msg000275.html
and follow ups for the solution.

Christoph