Patch "cxl: Check if vphb exists before iterating over AFU devices" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Dec 21, 2017

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2017-12-21 08:03 UTC #0 lore raw

This is a note to let you know that I've just added the patch titled

cxl: Check if vphb exists before iterating over AFU devices

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
cxl-check-if-vphb-exists-before-iterating-over-afu-devices.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 12841f87b7a8ceb3d54f171660f72a86941bfcb3 Mon Sep 17 00:00:00 2001

From: Vaibhav Jain <[email protected]>
Date: Thu, 23 Nov 2017 09:08:57 +0530
Subject: cxl: Check if vphb exists before iterating over AFU devices

From: Vaibhav Jain <[email protected]>

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 <[email protected]>

Acked-by Andrew Donnellan <[email protected]>

Acked-by Frederic Barrat <[email protected]>

Signed-off-by Michael Ellerman <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/misc/cxl/pci.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

drivers/misc/cxl/pci.c +13 -0

@@ -1329,6 +1329,9 @@ 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;

@@ -1369,6 +1372,10 @@ static pci_ers_result_t cxl_pci_error_de
 		 */
 		for (i = 0; i < adapter->slices; i++) {
 			afu = adapter->afu[i];
+			/*
+			 * 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;

@@ -1492,6 +1499,9 @@ static pci_ers_result_t cxl_pci_slot_res
 		if (cxl_afu_select_best_mode(afu))
 			goto err;
 
+		if (afu->phb == NULL)
+			continue;
+
 		cxl_pci_vphb_reconfigure(afu);
 
 		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

@@ -1556,6 +1566,9 @@ 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)

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/cxl-check-if-vphb-exists-before-iterating-over-afu-devices.patch