2008-03-05 19:31:03

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH] iwlwifi: fix locking unbalance in 4965 rate scale

From: Tomas Winkler <[email protected]>

This patch fixes locking unbalance after adding rcu locking
for sta

Signed-off-by: Tomas Winkler <[email protected]>
Signed-off-by: Reinette Chatre <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-4965-rs.c | 25 ++++++++++++-------------
1 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-4965-rs.c b/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
index 306fbdc..25e7386 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
@@ -852,19 +852,18 @@ static void rs_tx_status(void *priv_rate, struct net_device *dev,

sta = sta_info_get(local, hdr->addr1);

- if (!sta || !sta->rate_ctrl_priv) {
- rcu_read_unlock();
- return;
- }
+ if (!sta || !sta->rate_ctrl_priv)
+ goto out;
+

lq_sta = (struct iwl4965_lq_sta *)sta->rate_ctrl_priv;

if (!priv->lq_mngr.lq_ready)
- return;
+ goto out;

if ((priv->iw_mode == IEEE80211_IF_TYPE_IBSS) &&
!lq_sta->ibss_sta_added)
- return;
+ goto out;

table = &lq_sta->lq;
active_index = lq_sta->active_tbl;
@@ -915,8 +914,7 @@ static void rs_tx_status(void *priv_rate, struct net_device *dev,
tx_resp->control.tx_rate->bitrate)) {
IWL_DEBUG_RATE("initial rate does not match 0x%x\n",
tx_mcs.rate_n_flags);
- rcu_read_unlock();
- return;
+ goto out;
}

/* Update frame history window with "failure" for each Tx retry. */
@@ -1025,6 +1023,7 @@ static void rs_tx_status(void *priv_rate, struct net_device *dev,

/* See if there's a better rate or modulation mode to try. */
rs_rate_scale_perform(priv, dev, hdr, sta);
+out:
rcu_read_unlock();
return;
}
@@ -2229,8 +2228,7 @@ static void rs_get_rate(void *priv_rate, struct net_device *dev,
if (!ieee80211_is_data(fc) || is_multicast_ether_addr(hdr->addr1) ||
!sta || !sta->rate_ctrl_priv) {
sel->rate = rate_lowest(local, sband, sta);
- rcu_read_unlock();
- return;
+ goto out;
}

lq_sta = (struct iwl4965_lq_sta *)sta->rate_ctrl_priv;
@@ -2257,14 +2255,15 @@ static void rs_get_rate(void *priv_rate, struct net_device *dev,
goto done;
}

- done:
+done:
if ((i < 0) || (i > IWL_RATE_COUNT)) {
sel->rate = rate_lowest(local, sband, sta);
- return;
+ goto out;
}
- rcu_read_unlock();

sel->rate = &priv->ieee_rates[i];
+out:
+ rcu_read_unlock();
}

static void *rs_alloc_sta(void *priv, gfp_t gfp)
--
1.5.3.4