From: Vladimir Davydov <VDavydov@xxxxxxxxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
commit 74a1b1ea8a30b035aaad833bbd6b9263e72acfac upstream.
On e1000_down(), we should ensure every asynchronous work is canceled
before proceeding. Since the watchdog_task can schedule other works
apart from itself, it should be stopped first, but currently it is
stopped after the reset_task. This can result in the following race
leading to the reset_task running after the module unload:
e1000_down_and_stop(): e1000_watchdog():
---------------------- -----------------
cancel_work_sync(reset_task)
schedule_work(reset_task)
cancel_delayed_work_sync(watchdog_task)
The patch moves cancel_delayed_work_sync(watchdog_task) at the beginning
of e1000_down_and_stop() thus ensuring the race is impossible.
Cc: Tushar Dave <tushar.n.dave@xxxxxxxxx>
Cc: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/net/ethernet/intel/e1000/e1000_main.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 4ca676cb7f04..15c85d4f3774 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -494,13 +494,20 @@ static void e1000_down_and_stop(struct e1000_adapter *adapter)
{
set_bit(__E1000_DOWN, &adapter->flags);
- /* Only kill reset task if adapter is not resetting */
- if (!test_bit(__E1000_RESETTING, &adapter->flags))
- cancel_work_sync(&adapter->reset_task);
-
cancel_delayed_work_sync(&adapter->watchdog_task);
+
+ /*
+ * Since the watchdog task can reschedule other tasks, we should cancel
+ * it first, otherwise we can run into the situation when a work is
+ * still running after the adapter has been turned down.
+ */
+
cancel_delayed_work_sync(&adapter->phy_info_task);
cancel_delayed_work_sync(&adapter->fifo_stall_task);
+
+ /* Only kill reset task if adapter is not resetting */
+ if (!test_bit(__E1000_RESETTING, &adapter->flags))
+ cancel_work_sync(&adapter->reset_task);
}
void e1000_down(struct e1000_adapter *adapter)
--
2.0.4
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