From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net 5/8] e1000: fix possible reset_task running after adapter down Date: Wed, 27 Nov 2013 23:35:59 -0800 Message-ID: <1385624162-10116-6-git-send-email-jeffrey.t.kirsher@intel.com> References: <1385624162-10116-1-git-send-email-jeffrey.t.kirsher@intel.com> Cc: Vladimir Davydov , netdev@vger.kernel.org, gospo@redhat.com, sassmann@redhat.com, Tushar Dave , Patrick McHardy , Vladimir Davydov , Jeff Kirsher To: davem@davemloft.net Return-path: Received: from mga02.intel.com ([134.134.136.20]:62417 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753122Ab3K1Hge (ORCPT ); Thu, 28 Nov 2013 02:36:34 -0500 In-Reply-To: <1385624162-10116-1-git-send-email-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Vladimir Davydov 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 Cc: Patrick McHardy Signed-off-by: Vladimir Davydov Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- 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 619b0cb..46e6544 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) -- 1.8.3.1