Hello,
I got the following lockdep splat in 5.17-rc8. I don't have the reproducer
for this. I will send a follow up if I can find something useful.
<4>[ 93.549746][ T8]
<4>[ 93.551216][ T8] ======================================================
<4>[ 93.552707][ T8] WARNING: possible circular locking dependency detected
<4>[ 93.554195][ T8] 5.17.0-rc8-superb-owl-00001-g09688c0166e7 #2 Not tainted
<4>[ 93.555878][ T8] ------------------------------------------------------
<4>[ 93.557667][ T8] kworker/u16:0/8 is trying to acquire lock:
<4>[ 93.559459][ T8] ffff888167aa8170 (&rtwdev->mutex){+.+.}-{3:3}, at: rtw_ops_config+0x27/0xd0 [rtw88_core]
<4>[ 93.561248][ T8]
<4>[ 93.561248][ T8] but task is already holding lock:
<4>[ 93.564694][ T8] ffff888167aa2988 (&local->iflist_mtx){+.+.}-{3:3}, at: ieee80211_mgd_probe_ap+0x114/0x150 [mac80211]
<4>[ 93.566425][ T8]
<4>[ 93.566425][ T8] which lock already depends on the new lock.
<4>[ 93.566425][ T8]
<4>[ 93.571410][ T8]
<4>[ 93.571410][ T8] the existing dependency chain (in reverse order) is:
<4>[ 93.574576][ T8]
<4>[ 93.574576][ T8] -> #1 (&local->iflist_mtx){+.+.}-{3:3}:
<4>[ 93.577669][ T8] lock_acquire+0xc0/0x190
<4>[ 93.579207][ T8] __mutex_lock_common+0xab/0xe20
<4>[ 93.580726][ T8] mutex_lock_nested+0x1c/0x30
<4>[ 93.582196][ T8] ieee80211_iterate_interfaces+0x2a/0x50 [mac80211]
<4>[ 93.583681][ T8] rtw_fw_c2h_cmd_handle+0x16e/0x1b0 [rtw88_core]
<4>[ 93.585152][ T8] rtw_c2h_work+0x49/0x70 [rtw88_core]
<4>[ 93.586601][ T8] process_one_work+0x299/0x410
<4>[ 93.588012][ T8] worker_thread+0x240/0x440
<4>[ 93.589413][ T8] kthread+0xef/0x110
<4>[ 93.590817][ T8] ret_from_fork+0x1f/0x30
<4>[ 93.592222][ T8]
<4>[ 93.592222][ T8] -> #0 (&rtwdev->mutex){+.+.}-{3:3}:
<4>[ 93.594901][ T8] validate_chain+0x16d8/0x2800
<4>[ 93.596202][ T8] __lock_acquire+0x910/0xbf0
<4>[ 93.597473][ T8] lock_acquire+0xc0/0x190
<4>[ 93.598716][ T8] __mutex_lock_common+0xab/0xe20
<4>[ 93.599952][ T8] mutex_lock_nested+0x1c/0x30
<4>[ 93.601187][ T8] rtw_ops_config+0x27/0xd0 [rtw88_core]
<4>[ 93.602429][ T8] ieee80211_hw_config+0x32b/0x3a0 [mac80211]
<4>[ 93.603691][ T8] ieee80211_recalc_ps+0x128/0x1f0 [mac80211]
<4>[ 93.604942][ T8] ieee80211_mgd_probe_ap+0x120/0x150 [mac80211]
<4>[ 93.606196][ T8] process_one_work+0x299/0x410
<4>[ 93.607470][ T8] worker_thread+0x240/0x440
<4>[ 93.608732][ T8] kthread+0xef/0x110
<4>[ 93.610008][ T8] ret_from_fork+0x1f/0x30
<4>[ 93.611309][ T8]
<4>[ 93.611309][ T8] other info that might help us debug this:
<4>[ 93.611309][ T8]
<4>[ 93.615150][ T8] Possible unsafe locking scenario:
<4>[ 93.615150][ T8]
<4>[ 93.617743][ T8] CPU0 CPU1
<4>[ 93.619014][ T8] ---- ----
<4>[ 93.620289][ T8] lock(&local->iflist_mtx);
<4>[ 93.621556][ T8] lock(&rtwdev->mutex);
<4>[ 93.622855][ T8] lock(&local->iflist_mtx);
<4>[ 93.624149][ T8] lock(&rtwdev->mutex);
<4>[ 93.625423][ T8]
<4>[ 93.625423][ T8] *** DEADLOCK ***
<4>[ 93.625423][ T8]
<4>[ 93.629231][ T8] 4 locks held by kworker/u16:0/8:
<4>[ 93.630516][ T8] #0: ffff888165fb3938 ((wq_completion)phy0){+.+.}-{0:0}, at: process_one_work+0x241/0x410
<4>[ 93.631845][ T8] #1: ffffc9000016fe70 ((work_completion)(&ifmgd->monitor_work)){+.+.}-{0:0}, at: process_one_work+0x267/0x410
<4>[ 93.633174][ T8] #2: ffff888168b0cd00 (&wdev->mtx){+.+.}-{3:3}, at: ieee80211_mgd_probe_ap+0x2e/0x150 [mac80211]
<4>[ 93.634550][ T8] #3: ffff888167aa2988 (&local->iflist_mtx){+.+.}-{3:3}, at: ieee80211_mgd_probe_ap+0x114/0x150 [mac80211]
<4>[ 93.635943][ T8]
<4>[ 93.635943][ T8] stack backtrace:
<4>[ 93.638685][ T8] CPU: 5 PID: 8 Comm: kworker/u16:0 Not tainted 5.17.0-rc8-superb-owl-00001-g09688c0166e7 #2 c0022b89d38a680ae1699c58d0b58d598bc94d78
<4>[ 93.640140][ T8] Hardware name: HP HP Laptop 14s-dq2xxx/87FD, BIOS F.15 09/15/2021
<4>[ 93.640141][ T8] Workqueue: phy0 ieee80211_sta_monitor_work [mac80211]
<4>[ 93.640156][ T8] Call Trace:
<4>[ 93.640157][ T8] <TASK>
<4>[ 93.640159][ T8] dump_stack_lvl+0x5d/0x78
<4>[ 93.640161][ T8] print_circular_bug+0x5cb/0x5d0
<4>[ 93.640163][ T8] ? ret_from_fork+0x1f/0x30
<4>[ 93.640164][ T8] ? stack_trace_save+0x3a/0x50
<4>[ 93.640166][ T8] ? save_trace+0x3d/0x2c0
<4>[ 93.640168][ T8] ? __bfs+0x115/0x200
<4>[ 93.640169][ T8] check_noncircular+0xd5/0xe0
<4>[ 93.640170][ T8] ? rcu_read_lock_sched_held+0x34/0x70
<4>[ 93.640173][ T8] ? trace_pelt_cfs_tp+0x28/0xc0
<4>[ 93.640175][ T8] validate_chain+0x16d8/0x2800
<4>[ 93.640176][ T8] ? rcu_read_lock_sched_held+0x34/0x70
<4>[ 93.640179][ T8] ? lockdep_unlock+0x60/0xd0
<4>[ 93.662452][ T8] ? validate_chain+0x7f2/0x2800
<4>[ 93.663783][ T8] __lock_acquire+0x910/0xbf0
<4>[ 93.665091][ T8] lock_acquire+0xc0/0x190
<4>[ 93.666402][ T8] ? rtw_ops_config+0x27/0xd0 [rtw88_core a449d5db60ca04d68f4e53b03937ed71ebf1d2c4]
<4>[ 93.667734][ T8] ? rtw_ops_config+0x27/0xd0 [rtw88_core a449d5db60ca04d68f4e53b03937ed71ebf1d2c4]
<4>[ 93.669088][ T8] __mutex_lock_common+0xab/0xe20
<4>[ 93.670423][ T8] ? rtw_ops_config+0x27/0xd0 [rtw88_core a449d5db60ca04d68f4e53b03937ed71ebf1d2c4]
<4>[ 93.671779][ T8] ? lock_is_held_type+0xe2/0x140
<4>[ 93.673118][ T8] ? rtw_ops_config+0x27/0xd0 [rtw88_core a449d5db60ca04d68f4e53b03937ed71ebf1d2c4]
<4>[ 93.674480][ T8] mutex_lock_nested+0x1c/0x30
<4>[ 93.675854][ T8] rtw_ops_config+0x27/0xd0 [rtw88_core a449d5db60ca04d68f4e53b03937ed71ebf1d2c4]
<4>[ 93.677260][ T8] ieee80211_hw_config+0x32b/0x3a0 [mac80211 43fac5b3b5afe755bbfeab9090be9cf8c1dc014f]
<4>[ 93.678708][ T8] ieee80211_recalc_ps+0x128/0x1f0 [mac80211 43fac5b3b5afe755bbfeab9090be9cf8c1dc014f]
<4>[ 93.680147][ T8] ieee80211_mgd_probe_ap+0x120/0x150 [mac80211 43fac5b3b5afe755bbfeab9090be9cf8c1dc014f]
<4>[ 93.681607][ T8] process_one_work+0x299/0x410
<4>[ 93.683051][ T8] worker_thread+0x240/0x440
<4>[ 93.684512][ T8] ? worker_clr_flags+0x40/0x40
<4>[ 93.685957][ T8] kthread+0xef/0x110
<4>[ 93.687400][ T8] ? kthread_blkcg+0x30/0x30
<4>[ 93.688827][ T8] ret_from_fork+0x1f/0x30
<4>[ 93.690272][ T8] </TASK>
--
Ammar Faizi
