commit: 00d7ea11ff0783e24fe70778f3141270b561aaa1
From: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
Date: Fri, 15 Mar 2013 18:47:05 -0700
Subject: mwifiex: fix race when queuing commands
Running the following script repeatedly on XO-4 with SD8787
produces command timeout and system lockup.
insmod mwifiex_sdio.ko
sleep 1
ifconfig eth0 up
iwlist eth0 scan &
sleep 0.5
rmmod mwifiex_sdio
mwifiex_send_cmd_async() is called for sync as well as async
commands. (mwifiex_send_cmd_sync() internally calls it for
sync command.)
"adapter->cmd_queued" gets filled inside mwifiex_send_cmd_async()
routine for both types of commands. But it is used only for sync
commands in mwifiex_wait_queue_complete(). This could lead to a
race when two threads try to queue a sync command with another
sync/async command simultaneously.
Get rid of global variable and pass command node as a parameter
to mwifiex_wait_queue_complete() to fix the problem.
Cc: <stable@xxxxxxxxxxxxxxx> # 3.8
Reported-by: Daniel Drake <dsd@xxxxxxxxxx>
Tested-by: Daniel Drake <dsd@xxxxxxxxxx>
Tested-by: Marco Cesarano <marco@xxxxxxxxxxx>
Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
Signed-off-by: Bing Zhao <bzhao@xxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
---
drivers/net/wireless/mwifiex/cmdevt.c | 5 ++---
drivers/net/wireless/mwifiex/main.h | 4 ++--
drivers/net/wireless/mwifiex/scan.c | 8 ++++----
drivers/net/wireless/mwifiex/sta_ioctl.c | 10 ++--------
4 files changed, 10 insertions(+), 17 deletions(-)
diff --git a/drivers/net/wireless/mwifiex/cmdevt.c b/drivers/net/wireless/mwifiex/cmdevt.c
index 20a6c55..2ffabdd 100644
--- a/drivers/net/wireless/mwifiex/cmdevt.c
+++ b/drivers/net/wireless/mwifiex/cmdevt.c
@@ -484,8 +484,6 @@ int mwifiex_send_cmd_sync(struct mwifiex_private *priv, uint16_t cmd_no,
ret = mwifiex_send_cmd_async(priv, cmd_no, cmd_action, cmd_oid,
data_buf);
- if (!ret)
- ret = mwifiex_wait_queue_complete(adapter);
return ret;
}
@@ -588,9 +586,10 @@ int mwifiex_send_cmd_async(struct mwifiex_private *priv, uint16_t cmd_no,
if (cmd_no == HostCmd_CMD_802_11_SCAN) {
mwifiex_queue_scan_cmd(priv, cmd_node);
} else {
- adapter->cmd_queued = cmd_node;
mwifiex_insert_cmd_to_pending_q(adapter, cmd_node, true);
queue_work(adapter->workqueue, &adapter->main_work);
+ if (cmd_node->wait_q_enabled)
+ ret = mwifiex_wait_queue_complete(adapter, cmd_node);
}
return ret;
diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
index 553adfb..7035ade 100644
--- a/drivers/net/wireless/mwifiex/main.h
+++ b/drivers/net/wireless/mwifiex/main.h
@@ -723,7 +723,6 @@ struct mwifiex_adapter {
u16 cmd_wait_q_required;
struct mwifiex_wait_queue cmd_wait_q;
u8 scan_wait_q_woken;
- struct cmd_ctrl_node *cmd_queued;
spinlock_t queue_lock; /* lock for tx queues */
struct completion fw_load;
u8 country_code[IEEE80211_COUNTRY_STRING_LEN];
@@ -1018,7 +1017,8 @@ int mwifiex_request_set_multicast_list(struct mwifiex_private *priv,
struct mwifiex_multicast_list *mcast_list);
int mwifiex_copy_mcast_addr(struct mwifiex_multicast_list *mlist,
struct net_device *dev);
-int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter);
+int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter,
+ struct cmd_ctrl_node *cmd_queued);
int mwifiex_bss_start(struct mwifiex_private *priv, struct cfg80211_bss *bss,
struct cfg80211_ssid *req_ssid);
int mwifiex_cancel_hs(struct mwifiex_private *priv, int cmd_type);
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index bb60c27..d215b4d 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -1388,10 +1388,13 @@ int mwifiex_scan_networks(struct mwifiex_private *priv,
list_del(&cmd_node->list);
spin_unlock_irqrestore(&adapter->scan_pending_q_lock,
flags);
- adapter->cmd_queued = cmd_node;
mwifiex_insert_cmd_to_pending_q(adapter, cmd_node,
true);
queue_work(adapter->workqueue, &adapter->main_work);
+
+ /* Perform internal scan synchronously */
+ if (!priv->scan_request)
+ mwifiex_wait_queue_complete(adapter, cmd_node);
} else {
spin_unlock_irqrestore(&adapter->scan_pending_q_lock,
flags);
@@ -1946,9 +1949,6 @@ int mwifiex_request_scan(struct mwifiex_private *priv,
/* Normal scan */
ret = mwifiex_scan_networks(priv, NULL);
- if (!ret)
- ret = mwifiex_wait_queue_complete(priv->adapter);
-
up(&priv->async_sem);
return ret;
diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c
index 9f33c92..13100f8 100644
--- a/drivers/net/wireless/mwifiex/sta_ioctl.c
+++ b/drivers/net/wireless/mwifiex/sta_ioctl.c
@@ -54,16 +54,10 @@ int mwifiex_copy_mcast_addr(struct mwifiex_multicast_list *mlist,
* This function waits on a cmd wait queue. It also cancels the pending
* request after waking up, in case of errors.
*/
-int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter)
+int mwifiex_wait_queue_complete(struct mwifiex_adapter *adapter,
+ struct cmd_ctrl_node *cmd_queued)
{
int status;
- struct cmd_ctrl_node *cmd_queued;
-
- if (!adapter->cmd_queued)
- return 0;
-
- cmd_queued = adapter->cmd_queued;
- adapter->cmd_queued = NULL;
dev_dbg(adapter->dev, "cmd pending\n");
atomic_inc(&adapter->cmd_pending);
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html