From f0f7c2275fb925ea287e2da0585d17bde3d1fd2e Mon Sep 17 00:00:00 2001
From: Douglas Anderson <dianders@chromium.org>
Date: Tue, 3 Oct 2017 20:49:44 +0530
Subject: [PATCH] mwifiex: minor cleanups w/ sta_list_spinlock in cfg80211.c
Git-commit: f0f7c2275fb925ea287e2da0585d17bde3d1fd2e
Patch-mainline: v4.15-rc1
References: FATE#326294

The sta_list_spinlock looks to be used to control locking of the
list. Specifically when someone has the lock they may be allowed
to modify or delete elements of the list.

That implies that we shouldn't access the fields of the elements
returned by mwifiex_get_sta_entry() after we've released the
spinlock. Let's make some small changes so this is true.

It's unlikely that this matters since it looks to be just error
handling, but it's nice to be clean.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ganapathi Bhat <gbhat@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/marvell/mwifiex/cfg80211.c  | 14 +++++++++-----
 drivers/net/wireless/marvell/mwifiex/sta_event.c |  6 ++----
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
index cc7d777eb26c..3638b6130216 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
@@ -3794,9 +3794,8 @@ mwifiex_cfg80211_tdls_chan_switch(struct wiphy *wiphy, struct net_device *dev,
 
 	spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 	sta_ptr = mwifiex_get_sta_entry(priv, addr);
-	spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 	if (!sta_ptr) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "%s: Invalid TDLS peer %pM\n",
 			  __func__, addr);
 		return -ENOENT;
@@ -3804,15 +3803,18 @@ mwifiex_cfg80211_tdls_chan_switch(struct wiphy *wiphy, struct net_device *dev,
 
 	if (!(sta_ptr->tdls_cap.extcap.ext_capab[3] &
 	      WLAN_EXT_CAPA4_TDLS_CHAN_SWITCH)) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "%pM do not support tdls cs\n", addr);
 		return -ENOENT;
 	}
 
 	if (sta_ptr->tdls_status == TDLS_CHAN_SWITCHING ||
 	    sta_ptr->tdls_status == TDLS_IN_OFF_CHAN) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "channel switch is running, abort request\n");
 		return -EALREADY;
 	}
+	spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 
 	chan = chandef->chan->hw_value;
 	second_chan_offset = mwifiex_get_sec_chan_offset(chan);
@@ -3833,18 +3835,20 @@ mwifiex_cfg80211_tdls_cancel_chan_switch(struct wiphy *wiphy,
 
 	spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 	sta_ptr = mwifiex_get_sta_entry(priv, addr);
-	spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 	if (!sta_ptr) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "%s: Invalid TDLS peer %pM\n",
 			  __func__, addr);
 	} else if (!(sta_ptr->tdls_status == TDLS_CHAN_SWITCHING ||
 		     sta_ptr->tdls_status == TDLS_IN_BASE_CHAN ||
 		     sta_ptr->tdls_status == TDLS_IN_OFF_CHAN)) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "tdls chan switch not initialize by %pM\n",
 			  addr);
-	} else
+	} else {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		mwifiex_stop_tdls_cs(priv, addr);
+	}
 }
 
 static int
diff --git a/drivers/net/wireless/marvell/mwifiex/sta_event.c b/drivers/net/wireless/marvell/mwifiex/sta_event.c
index 839df8a9634e..d8db412b76c6 100644
--- a/drivers/net/wireless/marvell/mwifiex/sta_event.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_event.c
@@ -359,13 +359,12 @@ static void mwifiex_process_uap_tx_pause(struct mwifiex_private *priv,
 	} else {
 		spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 		sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac);
-		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 		if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) {
 			sta_ptr->tx_pause = tp->tx_pause;
 			mwifiex_update_ralist_tx_pause(priv, tp->peermac,
 						       tp->tx_pause);
 		}
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 	}
 }
 
@@ -396,14 +395,13 @@ static void mwifiex_process_sta_tx_pause(struct mwifiex_private *priv,
 		if (mwifiex_is_tdls_link_setup(status)) {
 			spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 			sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac);
-			spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 			if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) {
 				sta_ptr->tx_pause = tp->tx_pause;
 				mwifiex_update_ralist_tx_pause(priv,
 							       tp->peermac,
 							       tp->tx_pause);
 			}
+			spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		}
 	}
 }
-- 
2.19.2