From 65fd846cb3f94ae63134fbd0f32564cf82539eaa Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 2 Sep 2022 16:12:52 +0200
Subject: wifi: mac80211: add vif/sta link RCU dereference macros

Add macros (and an exported function) to allow checking some
link RCU protected accesses that are happening in callbacks
from mac80211 and are thus under the correct lock.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/mac80211.h | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

(limited to 'include')

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index bfa6a1625c5c..d9e7f62cc972 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -18,6 +18,7 @@
 #include <linux/if_ether.h>
 #include <linux/skbuff.h>
 #include <linux/ieee80211.h>
+#include <linux/lockdep.h>
 #include <net/cfg80211.h>
 #include <net/codel.h>
 #include <net/ieee80211_radiotap.h>
@@ -1901,6 +1902,19 @@ struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev);
  */
 struct wireless_dev *ieee80211_vif_to_wdev(struct ieee80211_vif *vif);
 
+/**
+ * lockdep_vif_mutex_held - for lockdep checks on link poiners
+ * @vif: the interface to check
+ */
+static inline bool lockdep_vif_mutex_held(struct ieee80211_vif *vif)
+{
+	return lockdep_is_held(&ieee80211_vif_to_wdev(vif)->mtx);
+}
+
+#define link_conf_dereference_protected(vif, link_id)		\
+	rcu_dereference_protected((vif)->link_conf[link_id],	\
+				  lockdep_vif_mutex_held(vif))
+
 /**
  * enum ieee80211_key_flags - key flags
  *
@@ -2266,13 +2280,24 @@ struct ieee80211_sta {
 	u8 drv_priv[] __aligned(sizeof(void *));
 };
 
-/* FIXME: check the locking correctly */
+#ifdef CONFIG_LOCKDEP
+bool lockdep_sta_mutex_held(struct ieee80211_sta *pubsta);
+#else
+static inline bool lockdep_sta_mutex_held(struct ieee80211_sta *pubsta)
+{
+	return true;
+}
+#endif
+
+#define link_sta_dereference_protected(sta, link_id)		\
+	rcu_dereference_protected((sta)->link[link_id],		\
+				  lockdep_sta_mutex_held(sta))
+
 #define for_each_sta_active_link(vif, sta, link_sta, link_id)			\
 	for (link_id = 0; link_id < ARRAY_SIZE((sta)->link); link_id++)		\
 		if ((!(vif)->active_links ||					\
 		     (vif)->active_links & BIT(link_id)) &&			\
-		    ((link_sta) = rcu_dereference_protected((sta)->link[link_id],\
-							    1)))
+		    ((link_sta) = link_sta_dereference_protected(sta, link_id)))
 
 /**
  * enum sta_notify_cmd - sta notify command
-- 
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