* [PATCH] cxl: Check if vphb exists before iterating over AFU devices
@ 2017-11-22 5:46 Vaibhav Jain
2017-11-22 6:47 ` Andrew Donnellan
0 siblings, 1 reply; 8+ messages in thread
From: Vaibhav Jain @ 2017-11-22 5:46 UTC (permalink / raw)
To: linuxppc-dev, Frederic Barrat
Cc: Vaibhav Jain, Andrew Donnellan, Christophe Lombard,
Philippe Bergheaud, Alastair D'Silva
During an eeh a kernel-oops is reported if no vPHB to 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.
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
---
drivers/misc/cxl/pci.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index bb7fd3f4edab..80ac40cdc31b 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -2265,6 +2265,9 @@ 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 +2330,9 @@ 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)
--
2.14.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] cxl: Check if vphb exists before iterating over AFU devices
2017-11-22 5:46 [PATCH] cxl: Check if vphb exists before iterating over AFU devices Vaibhav Jain
@ 2017-11-22 6:47 ` Andrew Donnellan
2017-11-22 7:27 ` Vaibhav Jain
0 siblings, 1 reply; 8+ messages in thread
From: Andrew Donnellan @ 2017-11-22 6:47 UTC (permalink / raw)
To: Vaibhav Jain, linuxppc-dev, Frederic Barrat
Cc: Christophe Lombard, Philippe Bergheaud, Alastair D'Silva
On 22/11/17 16:46, Vaibhav Jain wrote:
> During an eeh a kernel-oops is reported if no vPHB to 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.
>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Looks to me like we might need the same fix in
cxl_vphb_error_detected()? It's called twice in
cxl_pci_error_detected(), and in only one of those cases is it
surrounded by an afu->phb NULL check.
> ---
> drivers/misc/cxl/pci.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
> index bb7fd3f4edab..80ac40cdc31b 100644
> --- a/drivers/misc/cxl/pci.c
> +++ b/drivers/misc/cxl/pci.c
> @@ -2265,6 +2265,9 @@ 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 +2330,9 @@ 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
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cxl: Check if vphb exists before iterating over AFU devices
2017-11-22 6:47 ` Andrew Donnellan
@ 2017-11-22 7:27 ` Vaibhav Jain
0 siblings, 0 replies; 8+ messages in thread
From: Vaibhav Jain @ 2017-11-22 7:27 UTC (permalink / raw)
To: Andrew Donnellan, linuxppc-dev, Frederic Barrat
Cc: Christophe Lombard, Philippe Bergheaud, Alastair D'Silva
Andrew Donnellan <andrew.donnellan@au1.ibm.com> writes:
> Looks to me like we might need the same fix in
> cxl_vphb_error_detected()? It's called twice in
> cxl_pci_error_detected(), and in only one of those cases is it
> surrounded by an afu->phb NULL check.
Thanks for catching this. Will send a v2 with update.
--
Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Linux Technology Center, IBM India Pvt. Ltd.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cxl: Check if vphb exists before iterating over AFU devices
2017-12-21 4:06 Vaibhav Jain
@ 2017-12-21 8:03 ` Greg KH
0 siblings, 0 replies; 8+ messages in thread
From: Greg KH @ 2017-12-21 8:03 UTC (permalink / raw)
To: Vaibhav Jain
Cc: stable, Andrew Donnellan, Frederic Barrat, Michael Ellerman,
linuxppc-dev
On Thu, Dec 21, 2017 at 09:36:19AM +0530, Vaibhav Jain wrote:
> commit 12841f87b7a8ceb3d54f171660f72a86941bfcb3 upstream, for 4.3.
Thanks, now applied to 4.4.
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH] cxl: Check if vphb exists before iterating over AFU devices
@ 2017-12-21 4:06 Vaibhav Jain
2017-12-21 8:03 ` Greg KH
0 siblings, 1 reply; 8+ messages in thread
From: Vaibhav Jain @ 2017-12-21 4:06 UTC (permalink / raw)
To: stable
Cc: Vaibhav Jain, Andrew Donnellan, Frederic Barrat,
Michael Ellerman, linuxppc-dev
commit 12841f87b7a8ceb3d54f171660f72a86941bfcb3 upstream, for 4.3.
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")
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>
---
Changelog:
- Rebased the patch on 4.3 stable tree
---
drivers/misc/cxl/pci.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 85761d7eb333..b982329f3837 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1328,6 +1328,9 @@ 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;
@@ -1368,6 +1371,10 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
*/
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;
@@ -1491,6 +1498,9 @@ 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;
+
cxl_pci_vphb_reconfigure(afu);
list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
@@ -1555,6 +1565,9 @@ 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)
--
2.14.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] cxl: Check if vphb exists before iterating over AFU devices
2017-12-20 17:03 ` Greg KH
@ 2017-12-21 4:05 ` Vaibhav Jain
0 siblings, 0 replies; 8+ messages in thread
From: Vaibhav Jain @ 2017-12-21 4:05 UTC (permalink / raw)
To: Greg KH
Cc: stable, Andrew Donnellan, Frederic Barrat, linuxppc-dev,
Michael Ellerman
Greg KH <greg@kroah.com> writes:
> On Wed, Dec 20, 2017 at 03:07:06PM +0530, Vaibhav Jain wrote:
>> commit 12841f87b7a8ceb3d54f171660f72a86941bfcb3 upstream, for 4.9.
>
> Thanks, do we also need this for 4.4? If so, can you provide a
> backport?
>
Thanks Greg for applying this patch on 4.9 stable tree. I have done a
back-port for 4.3+ and will send the back-ported-patch across.
Cheers,
--
Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Linux Technology Center, IBM India Pvt. Ltd.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cxl: Check if vphb exists before iterating over AFU devices
2017-12-20 9:37 Vaibhav Jain
@ 2017-12-20 17:03 ` Greg KH
2017-12-21 4:05 ` Vaibhav Jain
0 siblings, 1 reply; 8+ messages in thread
From: Greg KH @ 2017-12-20 17:03 UTC (permalink / raw)
To: Vaibhav Jain
Cc: stable, Andrew Donnellan, Frederic Barrat, linuxppc-dev,
Michael Ellerman
On Wed, Dec 20, 2017 at 03:07:06PM +0530, Vaibhav Jain wrote:
> commit 12841f87b7a8ceb3d54f171660f72a86941bfcb3 upstream, for 4.9.
Thanks, do we also need this for 4.4? If so, can you provide a
backport?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH] cxl: Check if vphb exists before iterating over AFU devices
@ 2017-12-20 9:37 Vaibhav Jain
2017-12-20 17:03 ` Greg KH
0 siblings, 1 reply; 8+ messages in thread
From: Vaibhav Jain @ 2017-12-20 9:37 UTC (permalink / raw)
To: stable
Cc: Vaibhav Jain, Andrew Donnellan, Frederic Barrat, linuxppc-dev,
Michael Ellerman
commit 12841f87b7a8ceb3d54f171660f72a86941bfcb3 upstream, for 4.9.
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")
Cc: stable@vger.kernel.org
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>
---
Changelog:
Rebased the upstream patch over stable 4.9 tree
---
drivers/misc/cxl/pci.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index eef202d4399b..a5422f483ad5 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1758,6 +1758,9 @@ 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;
@@ -1801,6 +1804,11 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
/* 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_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
@@ -2003,6 +2014,9 @@ 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)
--
2.14.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2017-12-21 8:03 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2017-11-22 5:46 [PATCH] cxl: Check if vphb exists before iterating over AFU devices Vaibhav Jain
2017-11-22 6:47 ` Andrew Donnellan
2017-11-22 7:27 ` Vaibhav Jain
2017-12-20 9:37 Vaibhav Jain
2017-12-20 17:03 ` Greg KH
2017-12-21 4:05 ` Vaibhav Jain
2017-12-21 4:06 Vaibhav Jain
2017-12-21 8:03 ` Greg KH
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