mac80211: add interface list lock (c771c9d8) · Commits · 戴 / test

include/net/mac80211.h

+2 −3

Original line number	Diff line number	Diff line
		@@ -928,9 +928,8 @@ enum ieee80211_hw_flags {
		* @workqueue: single threaded workqueue available for driver use,
		* allocated by mac80211 on registration and flushed when an
		* interface is removed.
		* NOTICE: All work performed on this workqueue should NEVER
		* acquire the RTNL lock (i.e. Don't use the function
		* ieee80211_iterate_active_interfaces())
		* NOTICE: All work performed on this workqueue must not
		* acquire the RTNL lock.
		*
		* @priv: pointer to private area that was allocated for driver use
		* along with this structure.

net/mac80211/ieee80211_i.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -643,7 +643,9 @@ struct ieee80211_local {
		struct crypto_blkcipher *wep_rx_tfm;
		u32 wep_iv;

		/* see iface.c */
		struct list_head interfaces;
		struct mutex iflist_mtx;

		/*
		* Key lock, protects sdata's key_list and sta_info's

net/mac80211/iface.c

+31 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,23 @@
		#include "mesh.h"
		#include "led.h"

		/**
		* DOC: Interface list locking
		*
		* The interface list in each struct ieee80211_local is protected
		* three-fold:
		*
		* (1) modifications may only be done under the RTNL
		* (2) modifications and readers are protected against each other by
		* the iflist_mtx.
		* (3) modifications are done in an RCU manner so atomic readers
		* can traverse the list in RCU-safe blocks.
		*
		* As a consequence, reads (traversals) of the list can be protected
		* by either the RTNL, the iflist_mtx or RCU.
		*/


		static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
		{
		int meshhdrlen;
		@@ -800,7 +817,9 @@ int ieee80211_if_add(struct ieee80211_local local, const char name,
		params->mesh_id_len,
		params->mesh_id);

		mutex_lock(&local->iflist_mtx);
		list_add_tail_rcu(&sdata->list, &local->interfaces);
		mutex_unlock(&local->iflist_mtx);

		if (new_dev)
		*new_dev = ndev;
		@@ -816,7 +835,10 @@ void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
		{
		ASSERT_RTNL();

		mutex_lock(&sdata->local->iflist_mtx);
		list_del_rcu(&sdata->list);
		mutex_unlock(&sdata->local->iflist_mtx);

		synchronize_rcu();
		unregister_netdevice(sdata->dev);
		}
		@@ -832,7 +854,16 @@ void ieee80211_remove_interfaces(struct ieee80211_local *local)
		ASSERT_RTNL();

		list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
		/*
		* we cannot hold the iflist_mtx across unregister_netdevice,
		* but we only need to hold it for list modifications to lock
		* out readers since we're under the RTNL here as all other
		* writers.
		*/
		mutex_lock(&local->iflist_mtx);
		list_del(&sdata->list);
		mutex_unlock(&local->iflist_mtx);

		unregister_netdevice(sdata->dev);
		}
		}

net/mac80211/main.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -758,6 +758,7 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
		local->hw.conf.radio_enabled = true;

		INIT_LIST_HEAD(&local->interfaces);
		mutex_init(&local->iflist_mtx);

		spin_lock_init(&local->key_lock);

		@@ -1008,6 +1009,8 @@ void ieee80211_free_hw(struct ieee80211_hw *hw)
		{
		struct ieee80211_local *local = hw_to_local(hw);

		mutex_destroy(&local->iflist_mtx);

		wiphy_free(local->hw.wiphy);
		}
		EXPORT_SYMBOL(ieee80211_free_hw);

net/mac80211/util.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -468,7 +468,7 @@ void ieee80211_iterate_active_interfaces(
		struct ieee80211_local *local = hw_to_local(hw);
		struct ieee80211_sub_if_data *sdata;

		rtnl_lock();
		mutex_lock(&local->iflist_mtx);

		list_for_each_entry(sdata, &local->interfaces, list) {
		switch (sdata->vif.type) {
		@@ -489,7 +489,7 @@ void ieee80211_iterate_active_interfaces(
		&sdata->vif);
		}

		rtnl_unlock();
		mutex_unlock(&local->iflist_mtx);
		}
		EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);

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