Messages in this thread Patch in this message | | | From | Vladimir Davydov <> | Subject | [PATCH 2/2] e1000: fix possible reset_task running after adapter down | Date | Fri, 22 Nov 2013 12:20:29 +0400 |
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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.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Tushar Dave <tushar.n.dave@intel.com> Cc: Patrick McHardy <kaber@trash.net> Cc: David S. Miller <davem@davemloft.net> --- 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 ca0723f..2d914de 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) -- 1.7.10.4
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