Commit 74a1b1ea authored Nov 23, 2013 by Vladimir Davydov Committed by Jeff Kirsher Nov 30, 2013

e1000: fix possible reset_task running after adapter down



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@intel.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

parent b2f963bf

drivers/net/ethernet/intel/e1000/e1000_main.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -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)