There is a circular locking dependency when configuring the
hardware ARP filters on association, occurring when flushing the mac80211
workqueue. This is what happens:
[ 92.026800] =======================================================
[ 92.030507] [ INFO: possible circular locking dependency detected ]
[ 92.030507] 2.6.34-04781-g2b2c009 #85
[ 92.030507] -------------------------------------------------------
[ 92.030507] modprobe/5225 is trying to acquire lock:
[ 92.030507] ((wiphy_name(local->hw.wiphy))){+.+.+.}, at: [<ffffffff8105b5c0>] flush_workq
ueue+0x0/0xb0
[ 92.030507]
[ 92.030507] but task is already holding lock:
[ 92.030507] (rtnl_mutex){+.+.+.}, at: [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507]
[ 92.030507] which lock already depends on the new lock.
[ 92.030507]
[ 92.030507]
[ 92.030507] the existing dependency chain (in reverse order) is:
[ 92.030507]
[ 92.030507] -> #2 (rtnl_mutex){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff81341754>] mutex_lock_nested+0x44/0x300
[ 92.030507] [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507] [<ffffffffa022d47c>] ieee80211_assoc_done+0x6c/0xe0 [mac80211]
[ 92.030507] [<ffffffffa022f2ad>] ieee80211_work_work+0x31d/0x1280 [mac80211]
[ 92.030507] -> #1 ((&local->work_work)){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105a51a>] worker_thread+0x22a/0x370
[ 92.030507] [<ffffffff8105ecc6>] kthread+0x96/0xb0
[ 92.030507] [<ffffffff81003a94>] kernel_thread_helper+0x4/0x10
[ 92.030507]
[ 92.030507] -> #0 ((wiphy_name(local->hw.wiphy))){+.+.+.}:
[ 92.030507] [<ffffffff81075fdc>] __lock_acquire+0x1c0c/0x1d50
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105b60e>] flush_workqueue+0x4e/0xb0
[ 92.030507] [<ffffffffa023ff7b>] ieee80211_stop_device+0x2b/0xb0 [mac80211]
[ 92.030507] [<ffffffffa0231635>] ieee80211_stop+0x3e5/0x680 [mac80211]
Fix the problem by moving the hardware ARP filter configuration to a
workqueue function.
Reported-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@xxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 3 +++
net/mac80211/iface.c | 3 +++
net/mac80211/main.c | 3 ++-
net/mac80211/mlme.c | 41 +++++++++++++++++++++++++++++------------
4 files changed, 37 insertions(+), 13 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4d3883e..893a5cc 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -329,6 +329,9 @@ struct ieee80211_if_managed {
struct work_struct monitor_work;
struct work_struct chswitch_work;
struct work_struct beacon_connection_loss_work;
+#ifdef CONFIG_INET
+ struct work_struct arp_config_work;
+#endif
unsigned long probe_timeout;
int probe_send_count;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1afa9ec..44bf800 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -477,6 +477,9 @@ static int ieee80211_stop(struct net_device *dev)
cancel_work_sync(&sdata->u.mgd.chswitch_work);
cancel_work_sync(&sdata->u.mgd.monitor_work);
cancel_work_sync(&sdata->u.mgd.beacon_connection_loss_work);
+#ifdef CONFIG_INET
+ cancel_work_sync(&sdata->u.mgd.arp_config_work);
+#endif
/*
* When we get here, the interface is marked down.
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 88b671a..5583980 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -379,7 +379,8 @@ static int ieee80211_ifa_changed(struct notifier_block *nb,
ifmgd = &sdata->u.mgd;
mutex_lock(&ifmgd->mtx);
if (ifmgd->associated)
- ieee80211_set_arp_filter(sdata);
+ ieee80211_queue_work(&sdata->local->hw,
+ &sdata->u.mgd.arp_config_work);
mutex_unlock(&ifmgd->mtx);
return NOTIFY_DONE;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ac68c41..c3bf0a2 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -853,6 +853,11 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
ieee80211_bss_info_change_notify(sdata, bss_info_changed);
+#ifdef CONFIG_INET
+ /* Configure hardware ARP filter with current IPv4 config */
+ ieee80211_queue_work(&sdata->local->hw, &sdata->u.mgd.arp_config_work);
+#endif
+
mutex_lock(&local->iflist_mtx);
ieee80211_recalc_ps(local, -1);
ieee80211_recalc_smps(local, sdata);
@@ -1767,6 +1772,26 @@ static void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
kfree_skb(skb);
}
+#ifdef CONFIG_INET
+void ieee80211_arp_config_work(struct work_struct *work)
+{
+ struct ieee80211_sub_if_data *sdata =
+ container_of(work, struct ieee80211_sub_if_data,
+ u.mgd.arp_config_work);
+ struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+
+ if (!ieee80211_sdata_running(sdata))
+ return;
+
+ rtnl_lock();
+ mutex_lock(&ifmgd->mtx);
+ if (ifmgd->associated)
+ ieee80211_set_arp_filter(sdata);
+ mutex_unlock(&ifmgd->mtx);
+ rtnl_unlock();
+}
+#endif
+
static void ieee80211_sta_timer(unsigned long data)
{
struct ieee80211_sub_if_data *sdata =
@@ -1959,6 +1984,9 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
INIT_WORK(&ifmgd->beacon_connection_loss_work,
ieee80211_beacon_connection_loss_work);
+#ifdef CONFIG_INET
+ INIT_WORK(&ifmgd->arp_config_work, ieee80211_arp_config_work);
+#endif
setup_timer(&ifmgd->timer, ieee80211_sta_timer,
(unsigned long) sdata);
setup_timer(&ifmgd->bcn_mon_timer, ieee80211_sta_bcn_mon_timer,
@@ -2116,19 +2144,8 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
cfg80211_send_assoc_timeout(wk->sdata->dev,
wk->filter_ta);
return WORK_DONE_DESTROY;
-#ifdef CONFIG_INET
- } else {
- mutex_unlock(&wk->sdata->u.mgd.mtx);
-
- /*
- * configure ARP filter IP addresses to the driver,
- * intentionally outside the mgd mutex.
- */
- rtnl_lock();
- ieee80211_set_arp_filter(wk->sdata);
- rtnl_unlock();
-#endif
}
+ mutex_unlock(&wk->sdata->u.mgd.mtx);
}
cfg80211_send_rx_assoc(wk->sdata->dev, skb->data, skb->len);
--
1.6.3.3
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
