Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757575AbdLVKcE (ORCPT ); Fri, 22 Dec 2017 05:32:04 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:34624 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757464AbdLVIxN (ORCPT ); Fri, 22 Dec 2017 03:53:13 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vaibhav Jain , Andrew Donnellan , Frederic Barrat , Michael Ellerman Subject: [PATCH 4.9 001/104] cxl: Check if vphb exists before iterating over AFU devices Date: Fri, 22 Dec 2017 09:45:27 +0100 Message-Id: <20171222084609.374346392@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171222084609.262099650@linuxfoundation.org> References: <20171222084609.262099650@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2360 Lines: 72 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vaibhav Jain commit 12841f87b7a8ceb3d54f171660f72a86941bfcb3 upstream. During an eeh a kernel-oops is reported if no vPHB is allocated to the AFU. This happens as during AFU init, an error in creation of vPHB is a non-fatal error. Hence afu->phb should always be checked for NULL before iterating over it for the virtual AFU pci devices. This patch fixes the kenel-oops by adding a NULL pointer check for afu->phb before it is dereferenced. Fixes: 9e8df8a21963 ("cxl: EEH support") Signed-off-by: Vaibhav Jain Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- drivers/misc/cxl/pci.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -1758,6 +1758,9 @@ static pci_ers_result_t cxl_vphb_error_d /* There should only be one entry, but go through the list * anyway */ + if (afu->phb == NULL) + return result; + list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { if (!afu_dev->driver) continue; @@ -1801,6 +1804,11 @@ static pci_ers_result_t cxl_pci_error_de /* Only participate in EEH if we are on a virtual PHB */ if (afu->phb == NULL) return PCI_ERS_RESULT_NONE; + + /* + * Tell the AFU drivers; but we don't care what they + * say, we're going away. + */ cxl_vphb_error_detected(afu, state); } return PCI_ERS_RESULT_DISCONNECT; @@ -1941,6 +1949,9 @@ static pci_ers_result_t cxl_pci_slot_res if (cxl_afu_select_best_mode(afu)) goto err; + if (afu->phb == NULL) + continue; + list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { /* Reset the device context. * TODO: make this less disruptive @@ -2003,6 +2014,9 @@ static void cxl_pci_resume(struct pci_de for (i = 0; i < adapter->slices; i++) { afu = adapter->afu[i]; + if (afu->phb == NULL) + continue; + list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) { if (afu_dev->driver && afu_dev->driver->err_handler && afu_dev->driver->err_handler->resume)