From: Francesco Ruggeri fruggeri@arista.com
[ Upstream commit 024a8168b749db7a4aa40a5fbdfa04bf7e77c1c0 ]
We observed two panics involving races with igb_reset_task. The first panic is caused by this race condition:
kworker reboot -f
igb_reset_task igb_reinit_locked igb_down napi_synchronize __igb_shutdown igb_clear_interrupt_scheme igb_free_q_vectors igb_free_q_vector adapter->q_vector[v_idx] = NULL; napi_disable Panics trying to access adapter->q_vector[v_idx].napi_state
The second panic (a divide error) is caused by this race:
kworker reboot -f tx packet
igb_reset_task __igb_shutdown rtnl_lock() ... igb_clear_interrupt_scheme igb_free_q_vectors adapter->num_tx_queues = 0 ... rtnl_unlock() rtnl_lock() igb_reinit_locked igb_down igb_up netif_tx_start_all_queues dev_hard_start_xmit igb_xmit_frame igb_tx_queue_mapping Panics on r_idx % adapter->num_tx_queues
This commit applies to igb_reset_task the same changes that were applied to ixgbe in commit 2f90b8657ec9 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver"), commit 8f4c5c9fb87a ("ixgbe: reinit_locked() should be called with rtnl_lock") and commit 88adce4ea8f9 ("ixgbe: fix possible race in reset subtask").
Signed-off-by: Francesco Ruggeri fruggeri@arista.com Tested-by: Aaron Brown aaron.f.brown@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/igb/igb_main.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 9c7e75b3b6c7a..50fa0401c7014 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -5487,9 +5487,18 @@ static void igb_reset_task(struct work_struct *work) struct igb_adapter *adapter; adapter = container_of(work, struct igb_adapter, reset_task);
+ rtnl_lock(); + /* If we're already down or resetting, just bail */ + if (test_bit(__IGB_DOWN, &adapter->state) || + test_bit(__IGB_RESETTING, &adapter->state)) { + rtnl_unlock(); + return; + } + igb_dump(adapter); netdev_err(adapter->netdev, "Reset adapter\n"); igb_reinit_locked(adapter); + rtnl_unlock(); }
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