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Commit 12841f87 authored by Vaibhav Jain's avatar Vaibhav Jain Committed by Michael Ellerman
Browse files

cxl: Check if vphb exists before iterating over AFU devices 



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: 9e8df8a2 ("cxl: EEH support")
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: default avatarVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: default avatarAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 4d6c51b1

drivers/misc/cxl/pci.c

+10 −2
Original line number Original line Diff line number Diff line
@@ -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

	/* There should only be one entry, but go through the list

	 * anyway

	 * anyway

	 */

	 */

	if (afu->phb == NULL)

		return result;



	list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

	list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

		if (!afu_dev->driver)

		if (!afu_dev->driver)

			continue;

			continue;
@@ -2124,7 +2127,6 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev, 
			 * Tell the AFU drivers; but we don't care what they

			 * Tell the AFU drivers; but we don't care what they

			 * say, we're going away.

			 * 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;

		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))

		if (cxl_afu_select_best_mode(afu))

			goto err;

			goto err;





		if (afu->phb == NULL)

			continue;



		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

			/* Reset the device context.

			/* Reset the device context.

			 * TODO: make this less disruptive

			 * 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++) {

	for (i = 0; i < adapter->slices; i++) {

		afu = adapter->afu[i];

		afu = adapter->afu[i];





		if (afu->phb == NULL)

			continue;



		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

			if (afu_dev->driver && afu_dev->driver->err_handler &&

			if (afu_dev->driver && afu_dev->driver->err_handler &&

			    afu_dev->driver->err_handler->resume)

			    afu_dev->driver->err_handler->resume)