On Tuesday 26 June 2007 03:14, Johannes Berg wrote: > Got it. ieee80211_sta_config_auth is running off the workqueue and doing > rtnl_lock while ieee80211_if_shutdown is trying to flush the workqueue > with the rtnl lock held. Nice one, anybody have ideas how to fix? Why > does ieee80211_sta_config_auth need to take the rtnl anyway? > There is potential for racing with userspace without that lock, but it's not very likely or dangerous, and deadlocking is a whole lot worse. Patch attached to remove that locking for now until a better solution is found. Thanks, -Michael Wu
mac80211: remove rtnl locking in ieee80211_sta.c
From: Michael Wu <flamingice@xxxxxxxxxxxx>
The rtnl is held in ieee80211_sta.c to prevent some potential races with
userspace. Unfortunately, it also has the potential for deadlocks on
interface down. This patch removes the rtnl locking to eliminate the
deadlocks.
Signed-off-by: Michael Wu <flamingice@xxxxxxxxxxxx>
---
net/mac80211/ieee80211_sta.c | 6 ------
1 files changed, 0 insertions(+), 6 deletions(-)
diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
index 91b545c..4862797 100644
--- a/net/mac80211/ieee80211_sta.c
+++ b/net/mac80211/ieee80211_sta.c
@@ -25,7 +25,6 @@
#include <linux/wireless.h>
#include <linux/random.h>
#include <linux/etherdevice.h>
-#include <linux/rtnetlink.h>
#include <net/iw_handler.h>
#include <asm/types.h>
@@ -2073,12 +2072,9 @@ static int ieee80211_sta_config_auth(struct net_device *dev,
struct ieee80211_sta_bss *bss, *selected = NULL;
int top_rssi = 0, freq;
- rtnl_lock();
-
if (!ifsta->auto_channel_sel && !ifsta->auto_bssid_sel &&
!ifsta->auto_ssid_sel) {
ifsta->state = IEEE80211_AUTHENTICATE;
- rtnl_unlock();
ieee80211_sta_reset_auth(dev, ifsta);
return 0;
}
@@ -2121,7 +2117,6 @@ static int ieee80211_sta_config_auth(struct net_device *dev,
ieee80211_sta_set_bssid(dev, selected->bssid);
ieee80211_rx_bss_put(dev, selected);
ifsta->state = IEEE80211_AUTHENTICATE;
- rtnl_unlock();
ieee80211_sta_reset_auth(dev, ifsta);
return 0;
} else {
@@ -2132,7 +2127,6 @@ static int ieee80211_sta_config_auth(struct net_device *dev,
} else
ifsta->state = IEEE80211_DISABLED;
}
- rtnl_unlock();
return -1;
}
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