Since commit e38bad4766a110b61fa6038f10be16ced8c6cc38
mac80211: make ieee80211_iterate_active_interfaces not need rtnl
rt2500usb and rt73usb broke down due to attempting register access
in atomic context.
This patch adds a ieee80211_iterate_active_interfaces_rtnl()
function that behaves exactly the same as the original
ieee80211_iterate_active_interfaces() function before the above
mentioned patch.
The add_interface, remove_interface() and config_interface()
functions are already under the RTNL lock by mac80211 so simply
calling ieee80211_iterate_active_interfaces_rtnl() from within
a RTNL protected area would be sufficient to prevent race
conditions.
In rt2x00 only 1 callsite of ieee80211_iterate_active_interfaces()
needs to be changed, since only rt2x00lib_intf_scheduled() performs
hardware access per given interface.
Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
---
John please queue for 2.6.26, this bug impacts both rt2500usb and rt73usb
and effectively shuts both interfaces down from proper functioning.. :S
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 213adbb..7fdbb84 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -25,6 +25,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/rtnetlink.h>
#include "rt2x00.h"
#include "rt2x00lib.h"
@@ -474,11 +475,15 @@ static void rt2x00lib_intf_scheduled(struct work_struct *work)
/*
* Iterate over each interface and perform the
- * requested configurations.
- */
- ieee80211_iterate_active_interfaces(rt2x00dev->hw,
- rt2x00lib_intf_scheduled_iter,
- rt2x00dev);
+ * requested configurations, make sure to use
+ * the _rtnl version since the regular version
+ * requires atomic context.
+ */
+ rtnl_lock();
+ ieee80211_iterate_active_interfaces_rtnl(rt2x00dev->hw,
+ rt2x00lib_intf_scheduled_iter,
+ rt2x00dev);
+ rtnl_unlock();
}
/*
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 7e75516..741a3d6 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1601,6 +1601,24 @@ void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw,
void *data);
/**
+ * ieee80211_iterate_active_interfaces_rtnl - iterate active interfaces
+ *
+ * This function iterates over the interfaces associated with a given
+ * hardware that are currently active and calls the callback for them.
+ * This function allows the iterator function to sleep, the caller is
+ * responsible for proper locking mechanisms to prevent concurrency.
+ *
+ * @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_active_interfaces_rtnl(struct ieee80211_hw *hw,
+ void (*iterator)(void *data,
+ u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data);
+
+/**
* ieee80211_start_tx_ba_session - Start a tx Block Ack session.
* @hw: pointer as obtained from ieee80211_alloc_hw().
* @ra: receiver address of the BA session recipient
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 74c48ef..6980590 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -426,3 +426,36 @@ void ieee80211_iterate_active_interfaces(
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
+
+void ieee80211_iterate_active_interfaces_rtnl(
+ struct ieee80211_hw *hw,
+ void (*iterator)(void *data, u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+ struct ieee80211_sub_if_data *sdata;
+
+ ASSERT_RTNL();
+
+ list_for_each_entry(sdata, &local->interfaces, list) {
+ switch (sdata->vif.type) {
+ case IEEE80211_IF_TYPE_INVALID:
+ case IEEE80211_IF_TYPE_MNTR:
+ case IEEE80211_IF_TYPE_VLAN:
+ continue;
+ case IEEE80211_IF_TYPE_AP:
+ case IEEE80211_IF_TYPE_STA:
+ case IEEE80211_IF_TYPE_IBSS:
+ case IEEE80211_IF_TYPE_WDS:
+ case IEEE80211_IF_TYPE_MESH_POINT:
+ break;
+ }
+ if (sdata->dev == local->mdev)
+ continue;
+ if (netif_running(sdata->dev))
+ iterator(data, sdata->dev->dev_addr,
+ &sdata->vif);
+ }
+}
+EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_rtnl);
--
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