Re: kern/49065: ifconfig tun0 ... sequence locks up system

[Frank Kardel <kardel%netbsd.org@localhost>]

The following reply was made to PR kern/49065; it has been noted by GNATS.

From: Frank Kardel <kardel%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/49065: ifconfig tun0 ... sequence locks up system
Date: Sun, 03 Aug 2014 17:14:32 +0200

 Hmmm, LOCKDEBUG gives me:
 
 Starting named.
 panic: lockdebug_lookup: uninitialized lock (lock=0xc057e204, from=e8c9e670)
 cpu0: Begin traceback...
 0xdb3e3ba4: netbsd:db_panic+0xc
 0xdb3e3bd4: netbsd:vpanic+0x144
 0xdb3e3bec: netbsd:snprintf
 0xdb3e3c34: netbsd:lockdebug_wantlock+0x1e8
 0xdb3e3c7c: netbsd:mutex_enter+0x2b4
 0xdb3e3cb4: crypto:cryptoopen+0x84
 0xdb3e3ce4: netbsd:cdev_open+0xac
 0xdb3e3d3c: netbsd:spec_open+0x1e8
 0xdb3e3d5c: netbsd:VOP_OPEN+0x60
 0xdb3e3e34: netbsd:vn_open+0x1f8
 0xdb3e3eb4: netbsd:do_open+0xb0
 0xdb3e3ee4: netbsd:do_sys_openat+0x7c
 0xdb3e3f0c: netbsd:sys_open+0x34
 0xdb3e3f7c: netbsd:syscall+0x8c
 0xdb3e3fac: netbsd:swi_handler+0x98
 cpu0: End traceback...
 
 That's strange.
 
 disabling named gets me past that. Strangely on an sysinst upgraded RPI 
 I cannot reproduce the issue, I thought...
 
 But I bisected through the services running (namely named, mdnsd).
 
 Collected reproduceable facts:
      - It turns out that *running mdnsd*  will trigger the locking issue.
      - named triggers only a LOCKDEBUG (uninitialized lock) panic (see 
 above).
 
 So it looks like mdnsd's handling of the interfaces will leave a lock on 
 the socket structure AFAICS.
 
 Best regards
    Frank
 
 On 08/03/14 14:55, Nick Hudson wrote:
 > The following reply was made to PR kern/49065; it has been noted by GNATS.
 >
 > From: Nick Hudson <skrll%netbsd.org@localhost>
 > To: gnats-bugs%NetBSD.org@localhost
 > Cc: kardel%netbsd.org@localhost, kern-bug-people%netbsd.org@localhost,
 >   gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
 > Subject: Re: kern/49065: ifconfig tun0 ... sequence locks up system
 > Date: Sun, 03 Aug 2014 12:04:13 +0100
 >
 >   What's you full kernel config? Have you tried with LOCKDEBUG?
 >   
 >   Thanks,
 >   Nick
 >