Patch "wifi: mac80211: Add non-atomic station iterator" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: mac80211: Add non-atomic station iterator

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-mac80211-add-non-atomic-station-iterator.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 62c4d12f503c092263b527512217b4d11cdf357f
Author: Rory Little <rory@xxxxxxxxxxxxxxx>
Date:   Mon Aug 5 17:40:23 2024 -0700

    wifi: mac80211: Add non-atomic station iterator
    
    [ Upstream commit 7c3b69eadea9e57c28bf914b0fd70f268f3682e1 ]
    
    Drivers may at times want to iterate their stations with a function
    which requires some non-atomic operations.
    
    ieee80211_iterate_stations_mtx() introduces an API to iterate stations
    while holding that wiphy's mutex. This allows the iterating function to
    do non-atomic operations safely.
    
    Signed-off-by: Rory Little <rory@xxxxxxxxxxxxxxx>
    Link: https://patch.msgid.link/20240806004024.2014080-2-rory@xxxxxxxxxxxxxxx
    [unify internal list iteration functions]
    Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
    Stable-dep-of: 8fac3266c68a ("wifi: ath12k: fix atomic calls in ath12k_mac_op_set_bitrate_mask()")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 901fe3ac139e..835a58ce9ca5 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -6080,6 +6080,24 @@ void ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw,
 				       void (*iterator)(void *data,
 						struct ieee80211_sta *sta),
 				       void *data);
+
+/**
+ * ieee80211_iterate_stations_mtx - iterate stations
+ *
+ * This function iterates over all stations associated with a given
+ * hardware that are currently uploaded to the driver and calls the callback
+ * function for them. This version can only be used while holding the wiphy
+ * mutex.
+ *
+ * @hw: the hardware struct of which the interfaces should be iterated over
+ * @iterator: the iterator function to call
+ * @data: first argument of the iterator function
+ */
+void ieee80211_iterate_stations_mtx(struct ieee80211_hw *hw,
+				    void (*iterator)(void *data,
+						     struct ieee80211_sta *sta),
+				    void *data);
+
 /**
  * ieee80211_queue_work - add work onto the mac80211 workqueue
  *
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index d682c32821a1..cc3c46a82077 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -827,7 +827,8 @@ static void __iterate_stations(struct ieee80211_local *local,
 {
 	struct sta_info *sta;
 
-	list_for_each_entry_rcu(sta, &local->sta_list, list) {
+	list_for_each_entry_rcu(sta, &local->sta_list, list,
+				lockdep_is_held(&local->hw.wiphy->mtx)) {
 		if (!sta->uploaded)
 			continue;
 
@@ -848,6 +849,19 @@ void ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL_GPL(ieee80211_iterate_stations_atomic);
 
+void ieee80211_iterate_stations_mtx(struct ieee80211_hw *hw,
+				    void (*iterator)(void *data,
+						     struct ieee80211_sta *sta),
+				    void *data)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	lockdep_assert_wiphy(local->hw.wiphy);
+
+	__iterate_stations(local, iterator, data);
+}
+EXPORT_SYMBOL_GPL(ieee80211_iterate_stations_mtx);
+
 struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);