2010-06-14 18:24:40

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH 0/2] iwlwifi fixes for 2.6.35

We include two fixes targeting 2.6.35. The station management code received
some rework in 2.6.35 and we since discovered a few race conditions due to
the station management actions not being serialized. This fix is included.
The second fix addresses a potential system hang issue when unexpected
information is received from device.

These patches are also available from wireless-2.6 branch on
git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-2.6.git

Reinette Chatre (1):
iwlwifi: serialize station management actions

Shanyu Zhao (1):
iwlagn: verify flow id in compressed BA packet

drivers/net/wireless/iwlwifi/iwl-agn-tx.c | 5 +++++
drivers/net/wireless/iwlwifi/iwl-agn.c | 8 ++++++--
drivers/net/wireless/iwlwifi/iwl-sta.c | 4 ++++
drivers/net/wireless/iwlwifi/iwl3945-base.c | 9 +++++++--
4 files changed, 22 insertions(+), 4 deletions(-)



2010-06-14 18:24:41

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH 2/2] iwlagn: verify flow id in compressed BA packet

From: Shanyu Zhao <[email protected]>

The flow id (scd_flow) in a compressed BA packet should match the txq_id
of the queue from which the aggregated packets were sent. However, in
some hardware like the 1000 series, sometimes the flow id is 0 for the
txq_id (10 to 19). This can cause the annoying message:
[ 2213.306191] iwlagn 0000:01:00.0: Received BA when not expected
[ 2213.310178] iwlagn 0000:01:00.0: Read index for DMA queue txq id (0),
index 5, is out of range [0-256] 7 7.

And even worse, if agg->wait_for_ba is true when the bad BA is arriving,
this can cause system hang due to NULL pointer dereference because the
code is operating in a wrong tx queue!

Signed-off-by: Shanyu Zhao <[email protected]>
Signed-off-by: Pradeep Kulkarni <[email protected]>
Signed-off-by: Reinette Chatre <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-agn-tx.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
index a732f10..7d614c4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
@@ -1299,6 +1299,11 @@ void iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
sta_id = ba_resp->sta_id;
tid = ba_resp->tid;
agg = &priv->stations[sta_id].tid[tid].agg;
+ if (unlikely(agg->txq_id != scd_flow)) {
+ IWL_ERR(priv, "BA scd_flow %d does not match txq_id %d\n",
+ scd_flow, agg->txq_id);
+ return;
+ }

/* Find index just before block-ack window */
index = iwl_queue_dec_wrap(ba_resp_scd_ssn & 0xff, txq->q.n_bd);
--
1.7.0.4


2010-06-14 18:24:41

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH 1/2] iwlwifi: serialize station management actions

From: Reinette Chatre <[email protected]>

We are seeing some race conditions between incoming station management
requests (station add/remove) and the internal unassoc RXON command that
modifies station table. Modify these flows to require the mutex to be held
and thus serializing them.

This fixes http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2207

Signed-off-by: Reinette Chatre <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-agn.c | 8 ++++++--
drivers/net/wireless/iwlwifi/iwl-sta.c | 4 ++++
drivers/net/wireless/iwlwifi/iwl3945-base.c | 9 +++++++--
3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 7726e67..24aff65 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -3391,10 +3391,12 @@ static int iwlagn_mac_sta_add(struct ieee80211_hw *hw,
int ret;
u8 sta_id;

- sta_priv->common.sta_id = IWL_INVALID_STATION;
-
IWL_DEBUG_INFO(priv, "received request to add station %pM\n",
sta->addr);
+ mutex_lock(&priv->mutex);
+ IWL_DEBUG_INFO(priv, "proceeding to add station %pM\n",
+ sta->addr);
+ sta_priv->common.sta_id = IWL_INVALID_STATION;

atomic_set(&sta_priv->pending_frames, 0);
if (vif->type == NL80211_IFTYPE_AP)
@@ -3406,6 +3408,7 @@ static int iwlagn_mac_sta_add(struct ieee80211_hw *hw,
IWL_ERR(priv, "Unable to add station %pM (%d)\n",
sta->addr, ret);
/* Should we return success if return code is EEXIST ? */
+ mutex_unlock(&priv->mutex);
return ret;
}

@@ -3415,6 +3418,7 @@ static int iwlagn_mac_sta_add(struct ieee80211_hw *hw,
IWL_DEBUG_INFO(priv, "Initializing rate scaling for station %pM\n",
sta->addr);
iwl_rs_rate_init(priv, sta, sta_id);
+ mutex_unlock(&priv->mutex);

return 0;
}
diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c
index 83a2636..c27c13f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sta.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sta.c
@@ -1373,10 +1373,14 @@ int iwl_mac_sta_remove(struct ieee80211_hw *hw,

IWL_DEBUG_INFO(priv, "received request to remove station %pM\n",
sta->addr);
+ mutex_lock(&priv->mutex);
+ IWL_DEBUG_INFO(priv, "proceeding to remove station %pM\n",
+ sta->addr);
ret = iwl_remove_station(priv, sta_common->sta_id, sta->addr);
if (ret)
IWL_ERR(priv, "Error removing station %pM\n",
sta->addr);
+ mutex_unlock(&priv->mutex);
return ret;
}
EXPORT_SYMBOL(iwl_mac_sta_remove);
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 6c353ca..a27872d 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -3437,10 +3437,13 @@ static int iwl3945_mac_sta_add(struct ieee80211_hw *hw,
bool is_ap = vif->type == NL80211_IFTYPE_STATION;
u8 sta_id;

- sta_priv->common.sta_id = IWL_INVALID_STATION;
-
IWL_DEBUG_INFO(priv, "received request to add station %pM\n",
sta->addr);
+ mutex_lock(&priv->mutex);
+ IWL_DEBUG_INFO(priv, "proceeding to add station %pM\n",
+ sta->addr);
+ sta_priv->common.sta_id = IWL_INVALID_STATION;
+

ret = iwl_add_station_common(priv, sta->addr, is_ap, &sta->ht_cap,
&sta_id);
@@ -3448,6 +3451,7 @@ static int iwl3945_mac_sta_add(struct ieee80211_hw *hw,
IWL_ERR(priv, "Unable to add station %pM (%d)\n",
sta->addr, ret);
/* Should we return success if return code is EEXIST ? */
+ mutex_unlock(&priv->mutex);
return ret;
}

@@ -3457,6 +3461,7 @@ static int iwl3945_mac_sta_add(struct ieee80211_hw *hw,
IWL_DEBUG_INFO(priv, "Initializing rate scaling for station %pM\n",
sta->addr);
iwl3945_rs_rate_init(priv, sta, sta_id);
+ mutex_unlock(&priv->mutex);

return 0;
}
--
1.7.0.4