* [PATCH net] igb: re-assign hw address pointer on reset after PCI error
@ 2016-10-31 20:12 ` Guilherme G. Piccoli
0 siblings, 0 replies; 6+ messages in thread
From: Guilherme G. Piccoli @ 2016-10-31 20:12 UTC (permalink / raw)
To: intel-wired-lan; +Cc: jeffrey.t.kirsher, gpiccoli, netdev
Whenever the igb driver detects the result of a read operation returns
a value composed only by F's (like 0xFFFFFFFF), it will detach the
net_device, clear the hw_addr pointer and warn to the user that adapter's
link is lost - those steps happen on igb_rd32().
In case a PCI error happens on Power architecture, there's a recovery
mechanism called EEH, that will reset the PCI slot and call driver's
handlers to reset the adapter and network functionality as well.
We observed that once hw_addr is NULL after the error is detected on
igb_rd32(), it's never assigned back, so in the process of resetting
the network functionality we got a NULL pointer dereference in both
igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid
such bug, we re-assign the hw_addr value in the beginning of the
function igb_reset(), in case the hw_addr is NULL when we reach that
path.
Reported-by: Anthony H. Thai <ahthai@us.ibm.com>
Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
---
drivers/net/ethernet/intel/igb/igb_main.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index edc9a6a..c19119c 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -1873,6 +1873,13 @@ void igb_reset(struct igb_adapter *adapter)
struct e1000_fc_info *fc = &hw->fc;
u32 pba, hwm;
+ /* In case of PCI error, adapter might have lost its HW
+ * address; if we reached this point after an error scenario,
+ * we should re-assign the hw_addr based on the saved io_addr.
+ */
+ if (!hw->hw_addr)
+ hw->hw_addr = adapter->io_addr;
+
/* Repartition Pba for greater than 9k mtu
* To take effect CTRL.RST is required.
*/
--
2.1.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [Intel-wired-lan] [PATCH net] igb: re-assign hw address pointer on reset after PCI error
@ 2016-10-31 20:12 ` Guilherme G. Piccoli
0 siblings, 0 replies; 6+ messages in thread
From: Guilherme G. Piccoli @ 2016-10-31 20:12 UTC (permalink / raw)
To: intel-wired-lan
Whenever the igb driver detects the result of a read operation returns
a value composed only by F's (like 0xFFFFFFFF), it will detach the
net_device, clear the hw_addr pointer and warn to the user that adapter's
link is lost - those steps happen on igb_rd32().
In case a PCI error happens on Power architecture, there's a recovery
mechanism called EEH, that will reset the PCI slot and call driver's
handlers to reset the adapter and network functionality as well.
We observed that once hw_addr is NULL after the error is detected on
igb_rd32(), it's never assigned back, so in the process of resetting
the network functionality we got a NULL pointer dereference in both
igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid
such bug, we re-assign the hw_addr value in the beginning of the
function igb_reset(), in case the hw_addr is NULL when we reach that
path.
Reported-by: Anthony H. Thai <ahthai@us.ibm.com>
Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
---
drivers/net/ethernet/intel/igb/igb_main.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index edc9a6a..c19119c 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -1873,6 +1873,13 @@ void igb_reset(struct igb_adapter *adapter)
struct e1000_fc_info *fc = &hw->fc;
u32 pba, hwm;
+ /* In case of PCI error, adapter might have lost its HW
+ * address; if we reached this point after an error scenario,
+ * we should re-assign the hw_addr based on the saved io_addr.
+ */
+ if (!hw->hw_addr)
+ hw->hw_addr = adapter->io_addr;
+
/* Repartition Pba for greater than 9k mtu
* To take effect CTRL.RST is required.
*/
--
2.1.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Intel-wired-lan] [PATCH net] igb: re-assign hw address pointer on reset after PCI error
2016-10-31 20:12 ` [Intel-wired-lan] " Guilherme G. Piccoli
@ 2016-11-09 17:12 ` Alexander Duyck
-1 siblings, 0 replies; 6+ messages in thread
From: Alexander Duyck @ 2016-11-09 17:12 UTC (permalink / raw)
To: Guilherme G. Piccoli; +Cc: intel-wired-lan, Netdev, Fujinaka, Todd
On Mon, Oct 31, 2016 at 1:12 PM, Guilherme G. Piccoli
<gpiccoli@linux.vnet.ibm.com> wrote:
> Whenever the igb driver detects the result of a read operation returns
> a value composed only by F's (like 0xFFFFFFFF), it will detach the
> net_device, clear the hw_addr pointer and warn to the user that adapter's
> link is lost - those steps happen on igb_rd32().
>
> In case a PCI error happens on Power architecture, there's a recovery
> mechanism called EEH, that will reset the PCI slot and call driver's
> handlers to reset the adapter and network functionality as well.
>
> We observed that once hw_addr is NULL after the error is detected on
> igb_rd32(), it's never assigned back, so in the process of resetting
> the network functionality we got a NULL pointer dereference in both
> igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid
> such bug, we re-assign the hw_addr value in the beginning of the
> function igb_reset(), in case the hw_addr is NULL when we reach that
> path.
>
> Reported-by: Anthony H. Thai <ahthai@us.ibm.com>
> Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
> ---
> drivers/net/ethernet/intel/igb/igb_main.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> index edc9a6a..c19119c 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -1873,6 +1873,13 @@ void igb_reset(struct igb_adapter *adapter)
> struct e1000_fc_info *fc = &hw->fc;
> u32 pba, hwm;
>
> + /* In case of PCI error, adapter might have lost its HW
> + * address; if we reached this point after an error scenario,
> + * we should re-assign the hw_addr based on the saved io_addr.
> + */
> + if (!hw->hw_addr)
> + hw->hw_addr = adapter->io_addr;
> +
> /* Repartition Pba for greater than 9k mtu
> * To take effect CTRL.RST is required.
> */
It seems like this would have the potential to get noisy pretty
quickly since every reset would retrigger this.
It might make more sense to move this line into igb_io_slot_reset and
igb_resume where the device would have gone through a reset of some
sort and then had the state of the device restored and the device
memory access was re-enabled via pci_enable_device_mem. Also there is
no point in really doing the "if" since you should always be okay to
overwrite hw->hw_addr with adapter->io_addr.
Thanks.
- Alex
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Intel-wired-lan] [PATCH net] igb: re-assign hw address pointer on reset after PCI error
@ 2016-11-09 17:12 ` Alexander Duyck
0 siblings, 0 replies; 6+ messages in thread
From: Alexander Duyck @ 2016-11-09 17:12 UTC (permalink / raw)
To: intel-wired-lan
On Mon, Oct 31, 2016 at 1:12 PM, Guilherme G. Piccoli
<gpiccoli@linux.vnet.ibm.com> wrote:
> Whenever the igb driver detects the result of a read operation returns
> a value composed only by F's (like 0xFFFFFFFF), it will detach the
> net_device, clear the hw_addr pointer and warn to the user that adapter's
> link is lost - those steps happen on igb_rd32().
>
> In case a PCI error happens on Power architecture, there's a recovery
> mechanism called EEH, that will reset the PCI slot and call driver's
> handlers to reset the adapter and network functionality as well.
>
> We observed that once hw_addr is NULL after the error is detected on
> igb_rd32(), it's never assigned back, so in the process of resetting
> the network functionality we got a NULL pointer dereference in both
> igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid
> such bug, we re-assign the hw_addr value in the beginning of the
> function igb_reset(), in case the hw_addr is NULL when we reach that
> path.
>
> Reported-by: Anthony H. Thai <ahthai@us.ibm.com>
> Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
> ---
> drivers/net/ethernet/intel/igb/igb_main.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> index edc9a6a..c19119c 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -1873,6 +1873,13 @@ void igb_reset(struct igb_adapter *adapter)
> struct e1000_fc_info *fc = &hw->fc;
> u32 pba, hwm;
>
> + /* In case of PCI error, adapter might have lost its HW
> + * address; if we reached this point after an error scenario,
> + * we should re-assign the hw_addr based on the saved io_addr.
> + */
> + if (!hw->hw_addr)
> + hw->hw_addr = adapter->io_addr;
> +
> /* Repartition Pba for greater than 9k mtu
> * To take effect CTRL.RST is required.
> */
It seems like this would have the potential to get noisy pretty
quickly since every reset would retrigger this.
It might make more sense to move this line into igb_io_slot_reset and
igb_resume where the device would have gone through a reset of some
sort and then had the state of the device restored and the device
memory access was re-enabled via pci_enable_device_mem. Also there is
no point in really doing the "if" since you should always be okay to
overwrite hw->hw_addr with adapter->io_addr.
Thanks.
- Alex
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Intel-wired-lan] [PATCH net] igb: re-assign hw address pointer on reset after PCI error
2016-11-09 17:12 ` Alexander Duyck
@ 2016-11-10 16:48 ` Guilherme G. Piccoli
-1 siblings, 0 replies; 6+ messages in thread
From: Guilherme G. Piccoli @ 2016-11-10 16:48 UTC (permalink / raw)
To: Alexander Duyck; +Cc: intel-wired-lan, Netdev, Fujinaka, Todd
On 11/09/2016 03:12 PM, Alexander Duyck wrote:
> On Mon, Oct 31, 2016 at 1:12 PM, Guilherme G. Piccoli
> <gpiccoli@linux.vnet.ibm.com> wrote:
>> Whenever the igb driver detects the result of a read operation returns
>> a value composed only by F's (like 0xFFFFFFFF), it will detach the
>> net_device, clear the hw_addr pointer and warn to the user that adapter's
>> link is lost - those steps happen on igb_rd32().
>>
>> In case a PCI error happens on Power architecture, there's a recovery
>> mechanism called EEH, that will reset the PCI slot and call driver's
>> handlers to reset the adapter and network functionality as well.
>>
>> We observed that once hw_addr is NULL after the error is detected on
>> igb_rd32(), it's never assigned back, so in the process of resetting
>> the network functionality we got a NULL pointer dereference in both
>> igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid
>> such bug, we re-assign the hw_addr value in the beginning of the
>> function igb_reset(), in case the hw_addr is NULL when we reach that
>> path.
>>
>> Reported-by: Anthony H. Thai <ahthai@us.ibm.com>
>> Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com>
>> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
>> ---
>> drivers/net/ethernet/intel/igb/igb_main.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
>> index edc9a6a..c19119c 100644
>> --- a/drivers/net/ethernet/intel/igb/igb_main.c
>> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
>> @@ -1873,6 +1873,13 @@ void igb_reset(struct igb_adapter *adapter)
>> struct e1000_fc_info *fc = &hw->fc;
>> u32 pba, hwm;
>>
>> + /* In case of PCI error, adapter might have lost its HW
>> + * address; if we reached this point after an error scenario,
>> + * we should re-assign the hw_addr based on the saved io_addr.
>> + */
>> + if (!hw->hw_addr)
>> + hw->hw_addr = adapter->io_addr;
>> +
>> /* Repartition Pba for greater than 9k mtu
>> * To take effect CTRL.RST is required.
>> */
>
> It seems like this would have the potential to get noisy pretty
> quickly since every reset would retrigger this.
>
> It might make more sense to move this line into igb_io_slot_reset and
> igb_resume where the device would have gone through a reset of some
> sort and then had the state of the device restored and the device
> memory access was re-enabled via pci_enable_device_mem. Also there is
> no point in really doing the "if" since you should always be okay to
> overwrite hw->hw_addr with adapter->io_addr.
Thanks for the good suggestion Alexander, will send a V2.
Cheers,
Guilherme
>
> Thanks.
>
> - Alex
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Intel-wired-lan] [PATCH net] igb: re-assign hw address pointer on reset after PCI error
@ 2016-11-10 16:48 ` Guilherme G. Piccoli
0 siblings, 0 replies; 6+ messages in thread
From: Guilherme G. Piccoli @ 2016-11-10 16:48 UTC (permalink / raw)
To: intel-wired-lan
On 11/09/2016 03:12 PM, Alexander Duyck wrote:
> On Mon, Oct 31, 2016 at 1:12 PM, Guilherme G. Piccoli
> <gpiccoli@linux.vnet.ibm.com> wrote:
>> Whenever the igb driver detects the result of a read operation returns
>> a value composed only by F's (like 0xFFFFFFFF), it will detach the
>> net_device, clear the hw_addr pointer and warn to the user that adapter's
>> link is lost - those steps happen on igb_rd32().
>>
>> In case a PCI error happens on Power architecture, there's a recovery
>> mechanism called EEH, that will reset the PCI slot and call driver's
>> handlers to reset the adapter and network functionality as well.
>>
>> We observed that once hw_addr is NULL after the error is detected on
>> igb_rd32(), it's never assigned back, so in the process of resetting
>> the network functionality we got a NULL pointer dereference in both
>> igb_configure_tx_ring() and igb_configure_rx_ring(). In order to avoid
>> such bug, we re-assign the hw_addr value in the beginning of the
>> function igb_reset(), in case the hw_addr is NULL when we reach that
>> path.
>>
>> Reported-by: Anthony H. Thai <ahthai@us.ibm.com>
>> Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com>
>> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
>> ---
>> drivers/net/ethernet/intel/igb/igb_main.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
>> index edc9a6a..c19119c 100644
>> --- a/drivers/net/ethernet/intel/igb/igb_main.c
>> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
>> @@ -1873,6 +1873,13 @@ void igb_reset(struct igb_adapter *adapter)
>> struct e1000_fc_info *fc = &hw->fc;
>> u32 pba, hwm;
>>
>> + /* In case of PCI error, adapter might have lost its HW
>> + * address; if we reached this point after an error scenario,
>> + * we should re-assign the hw_addr based on the saved io_addr.
>> + */
>> + if (!hw->hw_addr)
>> + hw->hw_addr = adapter->io_addr;
>> +
>> /* Repartition Pba for greater than 9k mtu
>> * To take effect CTRL.RST is required.
>> */
>
> It seems like this would have the potential to get noisy pretty
> quickly since every reset would retrigger this.
>
> It might make more sense to move this line into igb_io_slot_reset and
> igb_resume where the device would have gone through a reset of some
> sort and then had the state of the device restored and the device
> memory access was re-enabled via pci_enable_device_mem. Also there is
> no point in really doing the "if" since you should always be okay to
> overwrite hw->hw_addr with adapter->io_addr.
Thanks for the good suggestion Alexander, will send a V2.
Cheers,
Guilherme
>
> Thanks.
>
> - Alex
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-11-10 16:48 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-10-31 20:12 [PATCH net] igb: re-assign hw address pointer on reset after PCI error Guilherme G. Piccoli
2016-10-31 20:12 ` [Intel-wired-lan] " Guilherme G. Piccoli
2016-11-09 17:12 ` Alexander Duyck
2016-11-09 17:12 ` Alexander Duyck
2016-11-10 16:48 ` Guilherme G. Piccoli
2016-11-10 16:48 ` Guilherme G. Piccoli
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.