From 69b97cf6dbce7403845a28bbc75d57f5be7b12ac Mon Sep 17 00:00:00 2001 From: Guilherme G Piccoli Date: Thu, 10 Nov 2016 16:46:43 -0200 Subject: [PATCH] igb: re-assign hw address pointer on reset after PCI error Whenever the igb driver detects the result of a read operation returns a value composed only by F's (like 0xFFFFFFFF), it will detach the net_device, clear the hw_addr pointer and warn to the user that adapter's link is lost - those steps happen on igb_rd32(). In case a PCI error happens on Power architecture, there's a recovery mechanism called EEH, that will reset the PCI slot and call driver's handlers to reset the adapter and network functionality as well. We observed that once hw_addr is NULL after the error is detected on igb_rd32(), it's never assigned back, so in the process of resetting the network functionality we got a NULL pointer dereference in both igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid such bug, this patch re-assigns the hw_addr value in the slot_reset handler. Reported-by: Anthony H Thai Reported-by: Harsha Thyagaraja Signed-off-by: Guilherme G Piccoli Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/igb/igb_main.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 1e4bd84724b2..82069bcabb9f 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -7898,6 +7898,11 @@ static pci_ers_result_t igb_io_slot_reset(struct pci_dev *pdev) pci_enable_wake(pdev, PCI_D3hot, 0); pci_enable_wake(pdev, PCI_D3cold, 0); + /* In case of PCI error, adapter lose its HW address + * so we should re-assign it here. + */ + hw->hw_addr = adapter->io_addr; + igb_reset(adapter); wr32(E1000_WUS, ~0); result = PCI_ERS_RESULT_RECOVERED; -- 2.20.1