* [RESEND][PATCH v2] cxl: Check if vphb exists before iterating over AFU devices
@ 2017-11-22 12:17 Vaibhav Jain
2017-11-22 17:26 ` Frederic Barrat
0 siblings, 1 reply; 3+ messages in thread
From: Vaibhav Jain @ 2017-11-22 12:17 UTC (permalink / raw)
To: linuxppc-dev, Frederic Barrat
Cc: Vaibhav Jain, Andrew Donnellan, Christophe Lombard,
Philippe Bergheaud, Alastair D'Silva, Michael Ellerman,
stable
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.
Fixes: 9e8df8a2196("cxl: EEH support")
Cc: stable@vger.kernel.org
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
---
Changelog:
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..18773343ab3e 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)
--
2.14.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RESEND][PATCH v2] cxl: Check if vphb exists before iterating over AFU devices
2017-11-22 12:17 [RESEND][PATCH v2] cxl: Check if vphb exists before iterating over AFU devices Vaibhav Jain
@ 2017-11-22 17:26 ` Frederic Barrat
2017-11-23 3:40 ` Vaibhav Jain
0 siblings, 1 reply; 3+ messages in thread
From: Frederic Barrat @ 2017-11-22 17:26 UTC (permalink / raw)
To: Vaibhav Jain, linuxppc-dev
Cc: Philippe Bergheaud, stable, Alastair D'Silva,
Andrew Donnellan, Christophe Lombard
Le 22/11/2017 à 13:17, Vaibhav Jain a écrit :
> During an eeh a kernel-oops is reported if no vPHB to allocated to the
typo, "to allocated". Not important, but....
> 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 <vaibhav@linux.vnet.ibm.com>
> ---
> Changelog:
>
> 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..18773343ab3e 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;
> +
.. that one is more annoying.
afu->phb == NULL?
Fred
> 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)
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RESEND][PATCH v2] cxl: Check if vphb exists before iterating over AFU devices
2017-11-22 17:26 ` Frederic Barrat
@ 2017-11-23 3:40 ` Vaibhav Jain
0 siblings, 0 replies; 3+ messages in thread
From: Vaibhav Jain @ 2017-11-23 3:40 UTC (permalink / raw)
To: Frederic Barrat, linuxppc-dev
Cc: Philippe Bergheaud, stable, Alastair D'Silva,
Andrew Donnellan, Christophe Lombard
Frederic Barrat <fbarrat@linux.vnet.ibm.com> writes:
>
> .. that one is more annoying.
> afu->phb == NULL?
Not sure how I missed that. Thanks for catching this Fred. I have sent a
v3 with the fix.
--
Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Linux Technology Center, IBM India Pvt. Ltd.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-11-23 3:40 UTC | newest]
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2017-11-22 12:17 [RESEND][PATCH v2] cxl: Check if vphb exists before iterating over AFU devices Vaibhav Jain
2017-11-22 17:26 ` Frederic Barrat
2017-11-23 3:40 ` Vaibhav Jain
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