[PATCH] net/failsafe: Fix crash due to in-valid sub-device port id

[Ferruh Yigit]

On 11/16/2022 12:11 PM, madhuker.mythri at oracle.com wrote:
> From: Madhuker Mythri <madhuker.mythri at oracle.com>
> 
> Crash occurring while the DPDK secondary processes trying to probe the
> tap-device, where tap-device is a sub-device of Fail-safe device.
> Some-times we get in-valid sub-devices(with the in-valid port-id's),
> due to which the IPC communication does not get response and causes the
> communication failures b/w primary/secondary process.
> So, need to validate the sub-device(tap) while secondary process probe in
> the Fail-safe PMD, to avoid such issues.
> 
> Bugzilla Id: 1116
> 
> Signed-off-by: Madhuker Mythri <madhuker.mythri at oracle.com>
> ---
>  drivers/net/failsafe/failsafe.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/failsafe/failsafe.c b/drivers/net/failsafe/failsafe.c
> index 32811403b4..51d4440ac7 100644
> --- a/drivers/net/failsafe/failsafe.c
> +++ b/drivers/net/failsafe/failsafe.c
> @@ -361,6 +361,9 @@ rte_pmd_failsafe_probe(struct rte_vdev_device *vdev)
>  			if (sdev->devargs.name[0] == '\0')
>  				continue;
>  
> +			if (!rte_eth_dev_is_valid_port(PORT_ID(sdev)))
> +				continue;
> +


This is in the 'FOREACH_SUBDEV()' block, why an invalid subdevice
provided by the macro?

Instead of invalid port check, should we fix the macro?

Overall I am not clear why this defect occurs, bugzilla report also
don't have much detail.
Can you please provide more details why this defect happens?