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authorAlexey Khoroshilov <khoroshilov@ispras.ru>2013-07-02 00:43:42 +0400
committerJohn W. Linville <linville@tuxdriver.com>2013-07-17 14:34:49 -0400
commit9494849e53e74048ee14d512feade01db402eef7 (patch)
treea7385029e763f93f3dc5d33c3ded13e3ac583470
parenta4943ccbc316fd74d3612d7a5984a91ab7e5dc8c (diff)
ath9k_htc: fix data race between request_firmware_nowait() callback and suspend()
ath9k_hif_usb_probe() requests firmware asynchronically and there is some initialization postponed till firmware is ready. In particular, ath9k_hif_usb_firmware_cb() callback initializes hif_dev->tx.tx_buf and hif_dev->tx.tx_pending lists. At the same time, ath9k_hif_usb_suspend() iterates that lists through ath9k_hif_usb_dealloc_urbs(). If suspend happens before request_firmware_nowait() callback is called, it can lead to oops. Similar issue could be in ath9k_hif_usb_disconnect(), but it is prevented using hif_dev->fw_done completion and HIF_USB_READY flag. The patch extends this approach to suspend() as well. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--drivers/net/wireless/ath/ath9k/hif_usb.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 9e582e1..2469db5 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -1082,7 +1082,7 @@ static void ath9k_hif_usb_firmware_fail(struct hif_device_usb *hif_dev)
struct device *dev = &hif_dev->udev->dev;
struct device *parent = dev->parent;
- complete(&hif_dev->fw_done);
+ complete_all(&hif_dev->fw_done);
if (parent)
device_lock(parent);
@@ -1131,7 +1131,7 @@ static void ath9k_hif_usb_firmware_cb(const struct firmware *fw, void *context)
release_firmware(fw);
hif_dev->flags |= HIF_USB_READY;
- complete(&hif_dev->fw_done);
+ complete_all(&hif_dev->fw_done);
return;
@@ -1316,7 +1316,10 @@ static int ath9k_hif_usb_suspend(struct usb_interface *interface,
if (!(hif_dev->flags & HIF_USB_START))
ath9k_htc_suspend(hif_dev->htc_handle);
- ath9k_hif_usb_dealloc_urbs(hif_dev);
+ wait_for_completion(&hif_dev->fw_done);
+
+ if (hif_dev->flags & HIF_USB_READY)
+ ath9k_hif_usb_dealloc_urbs(hif_dev);
return 0;
}