* [PATCH net] iavf: initialize waitqueues before starting watchdog_task
@ 2023-10-19 7:13 Michal Schmidt
2023-10-19 8:14 ` [Intel-wired-lan] " Paul Menzel
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Michal Schmidt @ 2023-10-19 7:13 UTC (permalink / raw)
To: netdev
Cc: Sudheer Mogilappagari, Jeff Kirsher, Jesse Brandeburg,
Tony Nguyen, intel-wired-lan
It is not safe to initialize the waitqueues after queueing the
watchdog_task. It will be using them.
The chance of this causing a real problem is very small, because
there will be some sleeping before any of the waitqueues get used.
I got a crash only after inserting an artificial sleep in iavf_probe.
Queue the watchdog_task as the last step in iavf_probe. Add a comment to
prevent repeating the mistake.
Fixes: fe2647ab0c99 ("i40evf: prevent VF close returning before state transitions to DOWN")
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
---
drivers/net/ethernet/intel/iavf/iavf_main.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 6a2e6d64bc3a..5b5c0525aa13 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -4982,8 +4982,6 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
INIT_WORK(&adapter->finish_config, iavf_finish_config);
INIT_DELAYED_WORK(&adapter->watchdog_task, iavf_watchdog_task);
INIT_DELAYED_WORK(&adapter->client_task, iavf_client_task);
- queue_delayed_work(adapter->wq, &adapter->watchdog_task,
- msecs_to_jiffies(5 * (pdev->devfn & 0x07)));
/* Setup the wait queue for indicating transition to down status */
init_waitqueue_head(&adapter->down_waitqueue);
@@ -4994,6 +4992,9 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
/* Setup the wait queue for indicating virtchannel events */
init_waitqueue_head(&adapter->vc_waitqueue);
+ queue_delayed_work(adapter->wq, &adapter->watchdog_task,
+ msecs_to_jiffies(5 * (pdev->devfn & 0x07)));
+ /* Initialization goes on in the work. Do not add more of it below. */
return 0;
err_ioremap:
--
2.41.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Intel-wired-lan] [PATCH net] iavf: initialize waitqueues before starting watchdog_task
2023-10-19 7:13 [PATCH net] iavf: initialize waitqueues before starting watchdog_task Michal Schmidt
@ 2023-10-19 8:14 ` Paul Menzel
2023-10-19 9:15 ` Przemek Kitszel
2023-10-20 23:51 ` Jakub Kicinski
2 siblings, 0 replies; 4+ messages in thread
From: Paul Menzel @ 2023-10-19 8:14 UTC (permalink / raw)
To: Michal Schmidt
Cc: netdev, Sudheer Mogilappagari, intel-wired-lan, Tony Nguyen,
Jeff Kirsher, Jesse Brandeburg
Dear Michal,
Am 19.10.23 um 09:13 schrieb Michal Schmidt:
> It is not safe to initialize the waitqueues after queueing the
> watchdog_task. It will be using them.
>
> The chance of this causing a real problem is very small, because
> there will be some sleeping before any of the waitqueues get used.
> I got a crash only after inserting an artificial sleep in iavf_probe.
>
> Queue the watchdog_task as the last step in iavf_probe. Add a comment to
> prevent repeating the mistake.
>
> Fixes: fe2647ab0c99 ("i40evf: prevent VF close returning before state transitions to DOWN")
> Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
> ---
> drivers/net/ethernet/intel/iavf/iavf_main.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
> index 6a2e6d64bc3a..5b5c0525aa13 100644
> --- a/drivers/net/ethernet/intel/iavf/iavf_main.c
> +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
> @@ -4982,8 +4982,6 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> INIT_WORK(&adapter->finish_config, iavf_finish_config);
> INIT_DELAYED_WORK(&adapter->watchdog_task, iavf_watchdog_task);
> INIT_DELAYED_WORK(&adapter->client_task, iavf_client_task);
> - queue_delayed_work(adapter->wq, &adapter->watchdog_task,
> - msecs_to_jiffies(5 * (pdev->devfn & 0x07)));
>
> /* Setup the wait queue for indicating transition to down status */
> init_waitqueue_head(&adapter->down_waitqueue);
> @@ -4994,6 +4992,9 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> /* Setup the wait queue for indicating virtchannel events */
> init_waitqueue_head(&adapter->vc_waitqueue);
>
> + queue_delayed_work(adapter->wq, &adapter->watchdog_task,
> + msecs_to_jiffies(5 * (pdev->devfn & 0x07)));
> + /* Initialization goes on in the work. Do not add more of it below. */
> return 0;
>
> err_ioremap:
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Kind regards,
Paul
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Intel-wired-lan] [PATCH net] iavf: initialize waitqueues before starting watchdog_task
2023-10-19 7:13 [PATCH net] iavf: initialize waitqueues before starting watchdog_task Michal Schmidt
2023-10-19 8:14 ` [Intel-wired-lan] " Paul Menzel
@ 2023-10-19 9:15 ` Przemek Kitszel
2023-10-20 23:51 ` Jakub Kicinski
2 siblings, 0 replies; 4+ messages in thread
From: Przemek Kitszel @ 2023-10-19 9:15 UTC (permalink / raw)
To: Michal Schmidt, netdev
Cc: Sudheer Mogilappagari, intel-wired-lan, Tony Nguyen, Jeff Kirsher,
Jesse Brandeburg
On 10/19/23 09:13, Michal Schmidt wrote:
> It is not safe to initialize the waitqueues after queueing the
> watchdog_task. It will be using them.
>
> The chance of this causing a real problem is very small, because
> there will be some sleeping before any of the waitqueues get used.
> I got a crash only after inserting an artificial sleep in iavf_probe.
>
> Queue the watchdog_task as the last step in iavf_probe. Add a comment to
> prevent repeating the mistake.
>
> Fixes: fe2647ab0c99 ("i40evf: prevent VF close returning before state transitions to DOWN")
> Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
> ---
> drivers/net/ethernet/intel/iavf/iavf_main.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
> index 6a2e6d64bc3a..5b5c0525aa13 100644
> --- a/drivers/net/ethernet/intel/iavf/iavf_main.c
> +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
> @@ -4982,8 +4982,6 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> INIT_WORK(&adapter->finish_config, iavf_finish_config);
> INIT_DELAYED_WORK(&adapter->watchdog_task, iavf_watchdog_task);
> INIT_DELAYED_WORK(&adapter->client_task, iavf_client_task);
> - queue_delayed_work(adapter->wq, &adapter->watchdog_task,
> - msecs_to_jiffies(5 * (pdev->devfn & 0x07)));
>
> /* Setup the wait queue for indicating transition to down status */
> init_waitqueue_head(&adapter->down_waitqueue);
> @@ -4994,6 +4992,9 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> /* Setup the wait queue for indicating virtchannel events */
> init_waitqueue_head(&adapter->vc_waitqueue);
>
> + queue_delayed_work(adapter->wq, &adapter->watchdog_task,
> + msecs_to_jiffies(5 * (pdev->devfn & 0x07)));
> + /* Initialization goes on in the work. Do not add more of it below. */
> return 0;
>
> err_ioremap:
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net] iavf: initialize waitqueues before starting watchdog_task
2023-10-19 7:13 [PATCH net] iavf: initialize waitqueues before starting watchdog_task Michal Schmidt
2023-10-19 8:14 ` [Intel-wired-lan] " Paul Menzel
2023-10-19 9:15 ` Przemek Kitszel
@ 2023-10-20 23:51 ` Jakub Kicinski
2 siblings, 0 replies; 4+ messages in thread
From: Jakub Kicinski @ 2023-10-20 23:51 UTC (permalink / raw)
To: Michal Schmidt
Cc: netdev, Sudheer Mogilappagari, Jeff Kirsher, Jesse Brandeburg,
Tony Nguyen, intel-wired-lan
On Thu, 19 Oct 2023 09:13:46 +0200 Michal Schmidt wrote:
> It is not safe to initialize the waitqueues after queueing the
> watchdog_task. It will be using them.
>
> The chance of this causing a real problem is very small, because
> there will be some sleeping before any of the waitqueues get used.
> I got a crash only after inserting an artificial sleep in iavf_probe.
>
> Queue the watchdog_task as the last step in iavf_probe. Add a comment to
> prevent repeating the mistake.
Applied as 7db31110438 in net, thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-10-19 7:13 [PATCH net] iavf: initialize waitqueues before starting watchdog_task Michal Schmidt
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2023-10-19 9:15 ` Przemek Kitszel
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