[LOCKDEP SPLAT 5.17-rc8] WARNING: possible circular locking dependency detected (at: rtw_ops_config+0x27/0xd0 | at: ieee80211_mgd_probe_ap+0x114/0x150)

[LOCKDEP SPLAT 5.17-rc8] WARNING: possible circular locking dependency detected (at: rtw_ops_config+0x27/0xd0 | at: ieee80211_mgd_probe_ap+0x114/0x150)

[Ammar Faizi]

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