From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Guilherme G. Piccoli" Subject: [PATCH net v2] igb: re-assign hw address pointer on reset after PCI error Date: Thu, 10 Nov 2016 16:46:43 -0200 Message-ID: <1478803603-30306-1-git-send-email-gpiccoli@linux.vnet.ibm.com> Cc: jeffrey.t.kirsher@intel.com, gpiccoli@linux.vnet.ibm.com, netdev@vger.kernel.org, alexander.duyck@gmail.com, todd.fujinaka@intel.com To: intel-wired-lan@lists.osuosl.org Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38387 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755817AbcKJSqt (ORCPT ); Thu, 10 Nov 2016 13:46:49 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uAAIdCXb001641 for ; Thu, 10 Nov 2016 13:46:48 -0500 Received: from e24smtp03.br.ibm.com (e24smtp03.br.ibm.com [32.104.18.24]) by mx0a-001b2d01.pphosted.com with ESMTP id 26msh70b7r-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 10 Nov 2016 13:46:48 -0500 Received: from localhost by e24smtp03.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 10 Nov 2016 16:46:46 -0200 Received: from d24relay04.br.ibm.com (d24relay04.br.ibm.com [9.18.232.146]) by d24dlp01.br.ibm.com (Postfix) with ESMTP id 2C1A13520074 for ; Thu, 10 Nov 2016 13:46:16 -0500 (EST) Received: from d24av03.br.ibm.com (d24av03.br.ibm.com [9.8.31.95]) by d24relay04.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id uAAIkiJj40042670 for ; Thu, 10 Nov 2016 16:46:44 -0200 Received: from d24av03.br.ibm.com (localhost [127.0.0.1]) by d24av03.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id uAAIkhfC007109 for ; Thu, 10 Nov 2016 16:46:44 -0200 Sender: netdev-owner@vger.kernel.org List-ID: 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 --- 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 edc9a6a..136ee9e 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -7878,6 +7878,11 @@ 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; -- 2.1.0