Re: [PATCH v3] cxl: Check if vphb exists before iterating over AFU devices
From: Andrew Donnellan <hidden>
Date: 2017-11-23 03:42:09
Also in:
stable
On 23/11/17 14:38, Vaibhav Jain wrote:
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: 9e8df8a2196("cxl: EEH support")
Cc: stable@vger.kernel.org
Signed-off-by: Vaibhav Jain <redacted>Thanks for fixing it! Acked-by: Andrew Donnellan <redacted>
quoted hunk ↗ jump to hunk
--- Changelog: v3 -> Fixed a reverse NULL check [Fred] Resend -> Added the 'Fixes' info and marking the patch to stable tree [Mpe] v2 -> Added the vphb NULL check to cxl_vphb_error_detected() [Andrew] --- drivers/misc/cxl/pci.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index bb7fd3f4edab..19969ee86d6f 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c@@ -2083,6 +2083,9 @@ static pci_ers_result_t cxl_vphb_error_detected(struct cxl_afu *afu, /* 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;@@ -2124,8 +2127,7 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev, * Tell the AFU drivers; but we don't care what they * say, we're going away. */ - if (afu->phb != NULL) - cxl_vphb_error_detected(afu, state); + cxl_vphb_error_detected(afu, state); } return PCI_ERS_RESULT_DISCONNECT; }@@ -2265,6 +2267,9 @@ static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev) 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@@ -2327,6 +2332,9 @@ static void cxl_pci_resume(struct pci_dev *pdev) 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)
-- Andrew Donnellan OzLabs, ADL Canberra andrew.donnellan@au1.ibm.com IBM Australia Limited