| From 12841f87b7a8ceb3d54f171660f72a86941bfcb3 Mon Sep 17 00:00:00 2001 |
| From: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> |
| Date: Thu, 23 Nov 2017 09:08:57 +0530 |
| Subject: cxl: Check if vphb exists before iterating over AFU devices |
| |
| From: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> |
| |
| 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 <vaibhav@linux.vnet.ibm.com> |
| Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> |
| Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> |
| Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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) |