From 00d7ea11ff0783e24fe70778f3141270b561aaa1 Mon Sep 17 00:00:00 2001 From: Amitkumar Karwar 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: # 3.8 Reported-by: Daniel Drake Tested-by: Daniel Drake Tested-by: Marco Cesarano Signed-off-by: Amitkumar Karwar Signed-off-by: Bing Zhao Signed-off-by: John W. Linville --- drivers/net/wireless/mwifiex/sta_ioctl.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'drivers/net/wireless/mwifiex/sta_ioctl.c') diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c index 9f33c92c90f5..13100f8de3db 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); -- cgit v1.2.1