[PATCH NET-PREV 35/51] cfg80211: Use fallback_nd_lock for registered devices

[Kirill Tkhai <tkhai@ya.ru>]

For now we use fallback_nd_lock for all drivers registering
via cfg80211_register_netdevice().

One of the reasons is that they are used as a bunch
in cfg80211_switch_netns(), while we want to call
dev_change_net_namespace() under nd_lock in one of
next patches.

Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
---
 drivers/net/wireless/ath/ath6kl/core.c        |    2 ++
 drivers/net/wireless/ath/wil6210/netdev.c     |    2 ++
 drivers/net/wireless/marvell/mwifiex/main.c   |    5 +++++
 drivers/net/wireless/quantenna/qtnfmac/core.c |    2 ++
 net/mac80211/main.c                           |    2 ++
 net/wireless/core.c                           |   10 ++++++++--
 net/wireless/nl80211.c                        |   14 ++++++++++++++
 7 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath6kl/core.c b/drivers/net/wireless/ath/ath6kl/core.c
index 4f0a7a185fc9..8c28f5a476ef 100644
--- a/drivers/net/wireless/ath/ath6kl/core.c
+++ b/drivers/net/wireless/ath/ath6kl/core.c
@@ -212,6 +212,7 @@ int ath6kl_core_init(struct ath6kl *ar, enum ath6kl_htc_type htc_type)
 		ar->avail_idx_map |= BIT(i);
 
 	rtnl_lock();
+	mutex_lock(&fallback_nd_lock.mutex);
 	wiphy_lock(ar->wiphy);
 
 	/* Add an initial station interface */
@@ -219,6 +220,7 @@ int ath6kl_core_init(struct ath6kl *ar, enum ath6kl_htc_type htc_type)
 				    NL80211_IFTYPE_STATION, 0, INFRA_NETWORK);
 
 	wiphy_unlock(ar->wiphy);
+	mutex_unlock(&fallback_nd_lock.mutex);
 	rtnl_unlock();
 
 	if (!wdev) {
diff --git a/drivers/net/wireless/ath/wil6210/netdev.c b/drivers/net/wireless/ath/wil6210/netdev.c
index d5d364683c0e..57958b44717d 100644
--- a/drivers/net/wireless/ath/wil6210/netdev.c
+++ b/drivers/net/wireless/ath/wil6210/netdev.c
@@ -474,9 +474,11 @@ int wil_if_add(struct wil6210_priv *wil)
 	wil_update_net_queues_bh(wil, vif, NULL, true);
 
 	rtnl_lock();
+	mutex_lock(&fallback_nd_lock.mutex);
 	wiphy_lock(wiphy);
 	rc = wil_vif_add(wil, vif);
 	wiphy_unlock(wiphy);
+	mutex_unlock(&fallback_nd_lock.mutex);
 	rtnl_unlock();
 	if (rc < 0)
 		goto free_dummy;
diff --git a/drivers/net/wireless/marvell/mwifiex/main.c b/drivers/net/wireless/marvell/mwifiex/main.c
index 96d1f6039fbc..c4b112d2f0b2 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.c
+++ b/drivers/net/wireless/marvell/mwifiex/main.c
@@ -623,6 +623,7 @@ static int _mwifiex_fw_dpc(const struct firmware *firmware, void *context)
 	}
 
 	rtnl_lock();
+	mutex_lock(&fallback_nd_lock.mutex);
 	wiphy_lock(adapter->wiphy);
 	/* Create station interface by default */
 	wdev = mwifiex_add_virtual_intf(adapter->wiphy, "mlan%d", NET_NAME_ENUM,
@@ -631,6 +632,7 @@ static int _mwifiex_fw_dpc(const struct firmware *firmware, void *context)
 		mwifiex_dbg(adapter, ERROR,
 			    "cannot create default STA interface\n");
 		wiphy_unlock(adapter->wiphy);
+		mutex_unlock(&fallback_nd_lock.mutex);
 		rtnl_unlock();
 		goto err_add_intf;
 	}
@@ -642,6 +644,7 @@ static int _mwifiex_fw_dpc(const struct firmware *firmware, void *context)
 			mwifiex_dbg(adapter, ERROR,
 				    "cannot create AP interface\n");
 			wiphy_unlock(adapter->wiphy);
+			mutex_unlock(&fallback_nd_lock.mutex);
 			rtnl_unlock();
 			goto err_add_intf;
 		}
@@ -654,11 +657,13 @@ static int _mwifiex_fw_dpc(const struct firmware *firmware, void *context)
 			mwifiex_dbg(adapter, ERROR,
 				    "cannot create p2p client interface\n");
 			wiphy_unlock(adapter->wiphy);
+			mutex_unlock(&fallback_nd_lock.mutex);
 			rtnl_unlock();
 			goto err_add_intf;
 		}
 	}
 	wiphy_unlock(adapter->wiphy);
+	mutex_unlock(&fallback_nd_lock.mutex);
 	rtnl_unlock();
 
 	mwifiex_drv_get_driver_version(adapter, fmt, sizeof(fmt) - 1);
diff --git a/drivers/net/wireless/quantenna/qtnfmac/core.c b/drivers/net/wireless/quantenna/qtnfmac/core.c
index 825b05dd3271..7952e3314aca 100644
--- a/drivers/net/wireless/quantenna/qtnfmac/core.c
+++ b/drivers/net/wireless/quantenna/qtnfmac/core.c
@@ -597,9 +597,11 @@ static int qtnf_core_mac_attach(struct qtnf_bus *bus, unsigned int macid)
 	mac->wiphy_registered = 1;
 
 	rtnl_lock();
+	mutex_lock(&fallback_nd_lock.mutex);
 	wiphy_lock(priv_to_wiphy(mac));
 	ret = qtnf_core_net_attach(mac, vif, "wlan%d", NET_NAME_ENUM);
 	wiphy_unlock(priv_to_wiphy(mac));
+	mutex_unlock(&fallback_nd_lock.mutex);
 	rtnl_unlock();
 
 	if (ret) {
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index a3104b6ea6f0..bacea2473a21 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1582,6 +1582,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	ieee80211_check_wbrf_support(local);
 
 	rtnl_lock();
+	mutex_lock(&fallback_nd_lock.mutex);
 	wiphy_lock(hw->wiphy);
 
 	/* add one default STA interface if supported */
@@ -1597,6 +1598,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	}
 
 	wiphy_unlock(hw->wiphy);
+	mutex_unlock(&fallback_nd_lock.mutex);
 	rtnl_unlock();
 
 #ifdef CONFIG_INET
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 4d5d351bd0b5..8ba0ada86678 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -1439,7 +1439,11 @@ int cfg80211_register_netdevice(struct net_device *dev)
 	/* we'll take care of this */
 	wdev->registered = true;
 	wdev->registering = true;
-	ret = register_netdevice(dev);
+
+	if (!mutex_is_locked(&fallback_nd_lock.mutex))
+		return -EXDEV;
+	attach_nd_lock(dev, &fallback_nd_lock);
+	ret = __register_netdevice(dev);
 	if (ret)
 		goto out;
 
@@ -1447,8 +1451,10 @@ int cfg80211_register_netdevice(struct net_device *dev)
 	ret = 0;
 out:
 	wdev->registering = false;
-	if (ret)
+	if (ret) {
+		detach_nd_lock(dev);
 		wdev->registered = false;
+	}
 	return ret;
 }
 EXPORT_SYMBOL(cfg80211_register_netdevice);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7397a372c78e..0fd66f75eace 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -16455,6 +16455,7 @@ nl80211_set_ttlm(struct sk_buff *skb, struct genl_info *info)
 #define NL80211_FLAG_NO_WIPHY_MTX	0x40
 #define NL80211_FLAG_MLO_VALID_LINK_ID	0x80
 #define NL80211_FLAG_MLO_UNSUPPORTED	0x100
+#define NL80211_FLAG_NEED_FALLBACK_ND_LOCK	0x200
 
 #define INTERNAL_FLAG_SELECTORS(__sel)			\
 	SELECTOR(__sel, NONE, 0) /* must be first */	\
@@ -16477,6 +16478,11 @@ nl80211_set_ttlm(struct sk_buff *skb, struct genl_info *info)
 		 NL80211_FLAG_NEED_WIPHY |		\
 		 NL80211_FLAG_NEED_RTNL |		\
 		 NL80211_FLAG_NO_WIPHY_MTX)		\
+	SELECTOR(__sel, WIPHY_RTNL_ND_LOCK,		\
+		 NL80211_FLAG_NEED_WIPHY |		\
+		 NL80211_FLAG_NEED_FALLBACK_ND_LOCK |	\
+		 NL80211_FLAG_NEED_RTNL |		\
+		 NL80211_FLAG_NO_WIPHY_MTX)		\
 	SELECTOR(__sel, WDEV_RTNL,			\
 		 NL80211_FLAG_NEED_WDEV |		\
 		 NL80211_FLAG_NEED_RTNL)		\
@@ -16545,6 +16551,7 @@ static int nl80211_pre_doit(const struct genl_split_ops *ops,
 	internal_flags = nl80211_internal_flags[ops->internal_flags];
 
 	rtnl_lock();
+	mutex_lock(&fallback_nd_lock.mutex);
 	if (internal_flags & NL80211_FLAG_NEED_WIPHY) {
 		rdev = cfg80211_get_dev_from_info(genl_info_net(info), info);
 		if (IS_ERR(rdev)) {
@@ -16621,11 +16628,15 @@ static int nl80211_pre_doit(const struct genl_split_ops *ops,
 		/* we keep the mutex locked until post_doit */
 		__release(&rdev->wiphy.mtx);
 	}
+
+	if (!(internal_flags & NL80211_FLAG_NEED_FALLBACK_ND_LOCK))
+		mutex_unlock(&fallback_nd_lock.mutex);
 	if (!(internal_flags & NL80211_FLAG_NEED_RTNL))
 		rtnl_unlock();
 
 	return 0;
 out_unlock:
+	mutex_unlock(&fallback_nd_lock.mutex);
 	rtnl_unlock();
 	dev_put(dev);
 	return err;
@@ -16656,6 +16667,8 @@ static void nl80211_post_doit(const struct genl_split_ops *ops,
 		wiphy_unlock(&rdev->wiphy);
 	}
 
+	if (internal_flags & NL80211_FLAG_NEED_FALLBACK_ND_LOCK)
+		mutex_unlock(&fallback_nd_lock.mutex);
 	if (internal_flags & NL80211_FLAG_NEED_RTNL)
 		rtnl_unlock();
 
@@ -16821,6 +16834,7 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.flags = GENL_UNS_ADMIN_PERM,
 		.internal_flags =
 			IFLAGS(NL80211_FLAG_NEED_WIPHY |
+			       NL80211_FLAG_NEED_FALLBACK_ND_LOCK |
 			       NL80211_FLAG_NEED_RTNL |
 			       /* we take the wiphy mutex later ourselves */
 			       NL80211_FLAG_NO_WIPHY_MTX),