cxl: Check if vphb exists before iterating over AFU devices (12841f87) · Commits · 戴 / test

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: ("cxl: EEH support") Cc: stable@vger.kernel.org # v4.3+ 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>

drivers/misc/cxl/pci.c

+10 −2

Original line number	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
		* anyway
		*/
		if (afu->phb == NULL)
		return result;

		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
		if (!afu_dev->driver)
		continue;
		@@ -2124,7 +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
		* say, we're going away.
		*/
		if (afu->phb != NULL)
		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)

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