From 13f61dfc5235cfa82b1efbcdf4b4f14d9be233da Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Mon, 11 Mar 2019 14:24:35 +0100 Subject: [PATCH] mt76: fix schedule while atomic in mt76x02_reset_state Fix following schedule while atomic in mt76x02_reset_state since synchronize_rcu is run inside a RCU section [44036.944222] mt76x2e 0000:06:00.0: MCU message 31 (seq 3) timed out [44036.944281] BUG: sleeping function called from invalid context at kernel/rcu/tree_exp.h:818 [44036.944284] in_atomic(): 1, irqs_disabled(): 0, pid: 28066, name: kworker/u4:1 [44036.944287] INFO: lockdep is turned off. [44036.944292] CPU: 1 PID: 28066 Comm: kworker/u4:1 Tainted: G W 5.0.0-rc7-wdn-t1+ #7 [44036.944294] Hardware name: Dell Inc. Studio XPS 1340/0K183D, BIOS A11 09/08/2009 [44036.944305] Workqueue: phy1 mt76x02_wdt_work [mt76x02_lib] [44036.944308] Call Trace: [44036.944317] dump_stack+0x67/0x90 [44036.944322] ___might_sleep.cold.88+0x9f/0xaf [44036.944327] rcu_blocking_is_gp+0x13/0x50 [44036.944330] synchronize_rcu+0x17/0x80 [44036.944337] mt76_sta_state+0x138/0x1d0 [mt76] [44036.944349] mt76x02_wdt_work+0x1c9/0x610 [mt76x02_lib] [44036.944355] process_one_work+0x2a5/0x620 [44036.944361] worker_thread+0x35/0x3e0 [44036.944368] kthread+0x11c/0x140 [44036.944376] ret_from_fork+0x3a/0x50 [44036.944384] BUG: scheduling while atomic: kworker/u4:1/28066/0x00000002 [44036.944387] INFO: lockdep is turned off. [44036.944389] Modules linked in: cmac ctr ccm af_packet snd_hda_codec_hdmi Introduce __mt76_sta_remove in order to run sta_remove without holding dev->mutex. Move __mt76_sta_remove outside of RCU section in mt76x02_reset_state Fixes: e4ebb8b403d1 ("mt76: mt76x2: implement full device restart on watchdog reset") Signed-off-by: Lorenzo Bianconi Signed-off-by: Kalle Valo --- drivers/net/wireless/mediatek/mt76/mac80211.c | 18 +++++++++++------- drivers/net/wireless/mediatek/mt76/mt76.h | 2 ++ .../net/wireless/mediatek/mt76/mt76x02_mmio.c | 19 ++++++++++--------- 3 files changed, 23 insertions(+), 16 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c index a033745adb2f..316167404729 100644 --- a/drivers/net/wireless/mediatek/mt76/mac80211.c +++ b/drivers/net/wireless/mediatek/mt76/mac80211.c @@ -679,19 +679,15 @@ out: return ret; } -static void -mt76_sta_remove(struct mt76_dev *dev, struct ieee80211_vif *vif, - struct ieee80211_sta *sta) +void __mt76_sta_remove(struct mt76_dev *dev, struct ieee80211_vif *vif, + struct ieee80211_sta *sta) { struct mt76_wcid *wcid = (struct mt76_wcid *)sta->drv_priv; - int idx = wcid->idx; - int i; + int i, idx = wcid->idx; rcu_assign_pointer(dev->wcid[idx], NULL); synchronize_rcu(); - mutex_lock(&dev->mutex); - if (dev->drv->sta_remove) dev->drv->sta_remove(dev, vif, sta); @@ -699,7 +695,15 @@ mt76_sta_remove(struct mt76_dev *dev, struct ieee80211_vif *vif, for (i = 0; i < ARRAY_SIZE(sta->txq); i++) mt76_txq_remove(dev, sta->txq[i]); mt76_wcid_free(dev->wcid_mask, idx); +} +EXPORT_SYMBOL_GPL(__mt76_sta_remove); +static void +mt76_sta_remove(struct mt76_dev *dev, struct ieee80211_vif *vif, + struct ieee80211_sta *sta) +{ + mutex_lock(&dev->mutex); + __mt76_sta_remove(dev, vif, sta); mutex_unlock(&dev->mutex); } diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h index cb50e96e736b..bcbfd3c4a44b 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76.h +++ b/drivers/net/wireless/mediatek/mt76/mt76.h @@ -695,6 +695,8 @@ int mt76_sta_state(struct ieee80211_hw *hw, struct ieee80211_vif *vif, struct ieee80211_sta *sta, enum ieee80211_sta_state old_state, enum ieee80211_sta_state new_state); +void __mt76_sta_remove(struct mt76_dev *dev, struct ieee80211_vif *vif, + struct ieee80211_sta *sta); struct ieee80211_sta *mt76_rx_convert(struct sk_buff *skb); diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c index 9de015bcd4f9..daaed1220147 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c +++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c @@ -441,19 +441,23 @@ static void mt76x02_reset_state(struct mt76x02_dev *dev) { int i; + lockdep_assert_held(&dev->mt76.mutex); + clear_bit(MT76_STATE_RUNNING, &dev->mt76.state); rcu_read_lock(); - ieee80211_iter_keys_rcu(dev->mt76.hw, NULL, mt76x02_key_sync, NULL); + rcu_read_unlock(); for (i = 0; i < ARRAY_SIZE(dev->mt76.wcid); i++) { - struct mt76_wcid *wcid = rcu_dereference(dev->mt76.wcid[i]); - struct mt76x02_sta *msta; struct ieee80211_sta *sta; struct ieee80211_vif *vif; + struct mt76x02_sta *msta; + struct mt76_wcid *wcid; void *priv; + wcid = rcu_dereference_protected(dev->mt76.wcid[i], + lockdep_is_held(&dev->mt76.mutex)); if (!wcid) continue; @@ -463,13 +467,10 @@ static void mt76x02_reset_state(struct mt76x02_dev *dev) priv = msta->vif; vif = container_of(priv, struct ieee80211_vif, drv_priv); - mt76_sta_state(dev->mt76.hw, vif, sta, - IEEE80211_STA_NONE, IEEE80211_STA_NOTEXIST); + __mt76_sta_remove(&dev->mt76, vif, sta); memset(msta, 0, sizeof(*msta)); } - rcu_read_unlock(); - dev->vif_mask = 0; dev->beacon_mask = 0; } @@ -489,11 +490,11 @@ static void mt76x02_watchdog_reset(struct mt76x02_dev *dev) for (i = 0; i < ARRAY_SIZE(dev->mt76.napi); i++) napi_disable(&dev->mt76.napi[i]); + mutex_lock(&dev->mt76.mutex); + if (restart) mt76x02_reset_state(dev); - mutex_lock(&dev->mt76.mutex); - if (dev->beacon_mask) mt76_clear(dev, MT_BEACON_TIME_CFG, MT_BEACON_TIME_CFG_BEACON_TX | -- 2.20.1