Stanislaw Gruszka 5b0efb4d67 rtw88: avoid circular locking between local->iflist_mtx and rtwdev->mutex ... Remove circular lock dependency by using atomic version of interfaces iterate in watch_dog_work(), hence avoid taking local->iflist_mtx (rtw_vif_watch_dog_iter() only update some data, it can be called from atomic context). Fixes below LOCKDEP warning: [ 1157.219415] ====================================================== [ 1157.225772] [ INFO: possible circular locking dependency detected ] [ 1157.232150] 3.10.0-1043.el7.sgruszka1.x86_64.debug #1 Not tainted [ 1157.238346] ------------------------------------------------------- [ 1157.244635] kworker/u4:2/14490 is trying to acquire lock: [ 1157.250194] (&rtwdev->mutex){+.+.+.}, at: [<ffffffffc098322b>] rtw_ops_config+0x2b/0x90 [rtw88] [ 1157.259151] but task is already holding lock: [ 1157.265085] (&local->iflist_mtx){+.+...}, at: [<ffffffffc0b8ab7a>] ieee80211_mgd_probe_ap.part.28+0xca/0x160 [mac80211] [ 1157.276169] which lock already depends on the new lock. [ 1157.284488] the existing dependency chain (in reverse order) is: [ 1157.292101] -> #2 (&local->iflist_mtx){+.+...}: [ 1157.296919] [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0 [ 1157.302955] [<ffffffffbce72793>] mutex_lock_nested+0x93/0x410 [ 1157.309416] [<ffffffffc0b6038f>] ieee80211_iterate_interfaces+0x2f/0x60 [mac80211] [ 1157.317730] [<ffffffffc09811ab>] rtw_watch_dog_work+0xcb/0x130 [rtw88] [ 1157.325003] [<ffffffffbc6d77bc>] process_one_work+0x22c/0x720 [ 1157.331481] [<ffffffffbc6d7dd6>] worker_thread+0x126/0x3b0 [ 1157.337589] [<ffffffffbc6e107f>] kthread+0xef/0x100 [ 1157.343260] [<ffffffffbce848b7>] ret_from_fork_nospec_end+0x0/0x39 [ 1157.350091] -> #1 ((&(&rtwdev->watch_dog_work)->work)){+.+...}: [ 1157.356314] [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0 [ 1157.362427] [<ffffffffbc6d570b>] flush_work+0x5b/0x310 [ 1157.368287] [<ffffffffbc6d740e>] __cancel_work_timer+0xae/0x170 [ 1157.374940] [<ffffffffbc6d7583>] cancel_delayed_work_sync+0x13/0x20 [ 1157.381930] [<ffffffffc0982b49>] rtw_core_stop+0x29/0x50 [rtw88] [ 1157.388679] [<ffffffffc098bee6>] rtw_enter_ips+0x16/0x20 [rtw88] [ 1157.395428] [<ffffffffc0983242>] rtw_ops_config+0x42/0x90 [rtw88] [ 1157.402173] [<ffffffffc0b13343>] ieee80211_hw_config+0xc3/0x680 [mac80211] [ 1157.409854] [<ffffffffc0b3925b>] ieee80211_do_open+0x69b/0x9c0 [mac80211] [ 1157.417418] [<ffffffffc0b395e9>] ieee80211_open+0x69/0x70 [mac80211] [ 1157.424496] [<ffffffffbcd03442>] __dev_open+0xe2/0x160 [ 1157.430356] [<ffffffffbcd03773>] __dev_change_flags+0xa3/0x180 [ 1157.436922] [<ffffffffbcd03879>] dev_change_flags+0x29/0x60 [ 1157.443224] [<ffffffffbcda14c4>] devinet_ioctl+0x794/0x890 [ 1157.449331] [<ffffffffbcda27b5>] inet_ioctl+0x75/0xa0 [ 1157.455087] [<ffffffffbccd54eb>] sock_do_ioctl+0x2b/0x60 [ 1157.461178] [<ffffffffbccd5753>] sock_ioctl+0x233/0x310 [ 1157.467109] [<ffffffffbc8bd820>] do_vfs_ioctl+0x410/0x6c0 [ 1157.473233] [<ffffffffbc8bdb71>] SyS_ioctl+0xa1/0xc0 [ 1157.478914] [<ffffffffbce84a5e>] system_call_fastpath+0x25/0x2a [ 1157.485569] -> #0 (&rtwdev->mutex){+.+.+.}: [ 1157.490022] [<ffffffffbc7409d1>] __lock_acquire+0xec1/0x1630 [ 1157.496305] [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0 [ 1157.502413] [<ffffffffbce72793>] mutex_lock_nested+0x93/0x410 [ 1157.508890] [<ffffffffc098322b>] rtw_ops_config+0x2b/0x90 [rtw88] [ 1157.515724] [<ffffffffc0b13343>] ieee80211_hw_config+0xc3/0x680 [mac80211] [ 1157.523370] [<ffffffffc0b8a4ca>] ieee80211_recalc_ps.part.27+0x9a/0x180 [mac80211] [ 1157.531685] [<ffffffffc0b8abc5>] ieee80211_mgd_probe_ap.part.28+0x115/0x160 [mac80211] [ 1157.540353] [<ffffffffc0b8b40d>] ieee80211_beacon_connection_loss_work+0x4d/0x80 [mac80211] [ 1157.549513] [<ffffffffbc6d77bc>] process_one_work+0x22c/0x720 [ 1157.555886] [<ffffffffbc6d7dd6>] worker_thread+0x126/0x3b0 [ 1157.562170] [<ffffffffbc6e107f>] kthread+0xef/0x100 [ 1157.567765] [<ffffffffbce848b7>] ret_from_fork_nospec_end+0x0/0x39 [ 1157.574579] other info that might help us debug this: [ 1157.582788] Chain exists of: &rtwdev->mutex --> (&(&rtwdev->watch_dog_work)->work) --> &local->iflist_mtx [ 1157.593024] Possible unsafe locking scenario: [ 1157.599046] CPU0 CPU1 [ 1157.603653] ---- ---- [ 1157.608258] lock(&local->iflist_mtx); [ 1157.612180] lock((&(&rtwdev->watch_dog_work)->work)); [ 1157.620074] lock(&local->iflist_mtx); [ 1157.626555] lock(&rtwdev->mutex); [ 1157.630124] *** DEADLOCK *** [ 1157.636148] 4 locks held by kworker/u4:2/14490: [ 1157.640755] #0: (%s#6){.+.+.+}, at: [<ffffffffbc6d774a>] process_one_work+0x1ba/0x720 [ 1157.648965] #1: ((&ifmgd->beacon_connection_loss_work)){+.+.+.}, at: [<ffffffffbc6d774a>] process_one_work+0x1ba/0x720 [ 1157.659950] #2: (&wdev->mtx){+.+.+.}, at: [<ffffffffc0b8aad5>] ieee80211_mgd_probe_ap.part.28+0x25/0x160 [mac80211] [ 1157.670901] #3: (&local->iflist_mtx){+.+...}, at: [<ffffffffc0b8ab7a>] ieee80211_mgd_probe_ap.part.28+0xca/0x160 [mac80211] [ 1157.682466] Fixes: e3037485c6 ("rtw88: new Realtek 802.11ac driver") Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Yan-Hsuan Chuang <yhchuang@realtek.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>		2019-05-28 14:40:41 +03:00
..
rtl8xxxu	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
rtl818x	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
rtlwifi	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
rtw88	rtw88: avoid circular locking between local->iflist_mtx and rtwdev->mutex	2019-05-28 14:40:41 +03:00
Kconfig	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00