Re: kern/60457 (Hang during shutdown/reboot with lagg(4) interface)

The following reply was made to PR kern/60457; it has been noted by GNATS.

From: Jeff Rizzo <[email protected]>
To: [email protected]
Cc: 
Subject: Re: kern/60457 (Hang during shutdown/reboot with lagg(4) interface)
Date: Sat, 18 Jul 2026 18:03:24 -0700

 I managed to get into DDB with a LOCKDEBUG kernel:
 
 db{9}> ps /l
 PID     LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
 2982   2982 3   1         0   ffff81230a576400             reboot lagg0.lacp
 1         1 3   9   8020180   ffff812324b78400               init wait
 0      2106 3   6       200   ffff812309b63400         poolthread pooljob
 0      1658 3   6       200   ffff8123082b6400       bridge_rtage 
 bridge_rtage
 0      1643 3   6       200   ffff8123082b6800         lagg0.lacp mutex
 0      1110 3   0       200   ffff81230b289c00              ipmi0 ipmi0
 0      1561 3   9       200   ffff812309176000     poolthread@127 pooljob
 0      1560 3   4       200   ffff812308702c00     poolthread@127 pooljob
 0      1558 3   1       200   ffff812308702400     poolthread@127 pooljob
 0      1551 3   1       200   ffff812308e8a800     poolthread@127 pooljob
 0      1549 3  11       200   ffff812308e8a000     poolthread@126 pooljob
 0      1548 3   1       200   ffff81230922ec00     poolthread@126 pooljob
 0      1547 3   8       200   ffff81230922e800     poolthread@126 pooljob
 0      1546 3   5       200   ffff81230922e400     poolthread@126 pooljob
 0      1545 3  11       200   ffff81230922e000     poolthread@126 pooljob
 0      1544 3   1       200   ffff812308ecac00     poolthread@126 pooljob
 0      1543 3   2       200   ffff812308eca800     poolthread@126 pooljob
 0      1542 3   3       200   ffff812308eca400     poolthread@126 pooljob
 0      1541 3   4       200   ffff812308eca000     poolthread@126 pooljob
 0      1540 3  11       200   ffff812324fa6c00     poolthread@126 pooljob
 0      1539 3   5       200   ffff812324fa6800     poolthread@126 pooljob
 db{9}> bt /a ffff81230a576400
 trace: pid 2982 lid 2982 at 0xffff8614bd43ba90
 sleepq_block() at netbsd:sleepq_block+0xea
 cv_wait() at netbsd:cv_wait+0xca
 workqueue_q_wait() at netbsd:workqueue_q_wait+0x90
 workqueue_wait() at netbsd:workqueue_wait+0xa9
 lacp_freeport() at netbsd:lacp_freeport+0x61
 lagg_proto_portctrl() at netbsd:lagg_proto_portctrl+0x120
 lagg_port_teardown() at netbsd:lagg_port_teardown+0x18c
 lagg_ifdetach() at netbsd:lagg_ifdetach+0x97
 simplehook_dohooks() at netbsd:simplehook_dohooks+0xa3
 ether_ifdetach() at netbsd:ether_ifdetach+0x23
 wm_detach() at netbsd:wm_detach+0x401
 config_detach_release() at netbsd:config_detach_release+0x1be
 config_detach_all() at netbsd:config_detach_all+0xc4
 cpu_reboot() at netbsd:cpu_reboot+0x1bd
 kern_reboot() at netbsd:kern_reboot+0x5f
 sys_reboot() at netbsd:sys_reboot+0x65
 syscall() at netbsd:syscall+0x9d
 --- syscall (number 208) ---
 netbsd:syscall+0x9d:
 db{9}> bt /a ffff8123082b6800
 trace: pid 0 lid 1643 at 0xffff8614bcdbde80
 sleepq_block() at netbsd:sleepq_block+0xea
 turnstile_block() at netbsd:turnstile_block+0x2d0
 mutex_enter() at netbsd:mutex_enter+0x142
 lacp_linkspeed_work() at netbsd:lacp_linkspeed_work+0x84
 workqueue_worker() at netbsd:workqueue_worker+0xf3
 db{9}> show all locks
 [Locks tracked through LWPs]
 
 ****** LWP 2982.2982 (reboot) @ 0xffff81230a576400, l_stat=3
 
 *** Locks held:
 
 * Lock 0 (initialized at netbsd:if_initialize+0x10e)
 lock address : ffff8123093ef7c0
 type         : sleep/adaptive
 initialized  : netbsd:if_initialize+0x10e
 shared holds :                  0 exclusive:                  1
 shares wanted:                  0 exclusive:                  0
 relevant cpu :                  1 last held:                  1
 relevant lwp : 0xffff81230a576400 last held: 0xffff81230a576400
 last locked* : netbsd:lagg_ifdetach+0x75
 unlocked     : netbsd:if_link_state_change_work+0x139
 owner field  : 0xffff81230a576400 wait/spin:                0/0
 Turnstile: no active turnstile for this lock.
 
 * Lock 1 (initialized at netbsd:lagg_clone_create+0x45)
 lock address : ffff8123057eb000
 type         : sleep/adaptive
 initialized  : netbsd:lagg_clone_create+0x45
 shared holds :                  0 exclusive:                  1
 shares wanted:                  0 exclusive:                  1
 relevant cpu :                  1 last held:                  1
 relevant lwp : 0xffff81230a576400 last held: 0xffff81230a576400
 last locked* : netbsd:lagg_ifdetach+0x7d
 unlocked     : netbsd:lagg_ifdetach+0x69
 owner field  : 0xffff81230a576400 wait/spin:                1/0
 Turnstile:
 => 0 waiting readers:
 => 1 waiting writers: 0xffff8123082b6800
 
 * Lock 2 (initialized at netbsd:if_initialize+0x10e)
 lock address : ffff812186a45c40
 type         : sleep/adaptive
 initialized  : netbsd:if_initialize+0x10e
 shared holds :                  0 exclusive:                  1
 shares wanted:                  0 exclusive:                  0
 relevant cpu :                  1 last held:                  1
 relevant lwp : 0xffff81230a576400 last held: 0xffff81230a576400
 last locked* : netbsd:lagg_port_teardown+0xe5
 unlocked     : netbsd:ether_del_vlantag+0x10d
 owner field  : 0xffff81230a576400 wait/spin:                0/0
 Turnstile: no active turnstile for this lock.
 
 *** Locks wanted: none
 
 ****** LWP 0.1643 (lagg0.lacp) @ 0xffff8123082b6800, l_stat=3
 
 *** Locks held: none
 
 *** Locks wanted:
 
 * Lock 0 (initialized at netbsd:lagg_clone_create+0x45)
 lock address : ffff8123057eb000
 type         : sleep/adaptive
 initialized  : netbsd:lagg_clone_create+0x45
 shared holds :                  0 exclusive:                  1
 shares wanted:                  0 exclusive:                  1
 relevant cpu :                  6 last held:                  1
 relevant lwp : 0xffff8123082b6800 last held: 0xffff81230a576400
 last locked* : netbsd:lagg_ifdetach+0x7d
 unlocked     : netbsd:lagg_ifdetach+0x69
 owner field  : 0xffff81230a576400 wait/spin:                1/0
 Turnstile:
 => 0 waiting readers:
 => 1 waiting writers: 0xffff8123082b6800
 
 [Locks tracked through CPUs]
 
 db{9}>