Re: [PATCH] bnx2x: fix page fault following EEH recovery

["Samudrala, Sridhar" <sridhar.samudrala@intel.com>]

On 6/8/2023 1:01 PM, David Christensen wrote:
> In the last step of the EEH recovery process, the EEH driver calls into
> bnx2x_io_resume() to re-initialize the NIC hardware via the function
> bnx2x_nic_load().  If an error occurs during bnx2x_nic_load(), OS and
> hardware resources are released and an error code is returned to the
> caller.  When called from bnx2x_io_resume(), the return code is ignored
> and the network interface is brought up unconditionally.  Later attempts
> to send a packet via this interface result in a page fault due to a null
> pointer reference.
> 
> This patch checks the return code of bnx2x_nic_load(), prints an error
> message if necessary, and does not enable the interface.
> 
> Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>

Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>

> ---
>   drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
> index 637d162bbcfa..1e7a6f1d4223 100644
> --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
> +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
> @@ -14294,11 +14294,16 @@ static void bnx2x_io_resume(struct pci_dev *pdev)
>   	bp->fw_seq = SHMEM_RD(bp, func_mb[BP_FW_MB_IDX(bp)].drv_mb_header) &
>   							DRV_MSG_SEQ_NUMBER_MASK;
>   
> -	if (netif_running(dev))
> -		bnx2x_nic_load(bp, LOAD_NORMAL);
> +	if (netif_running(dev)) {
> +		if (bnx2x_nic_load(bp, LOAD_NORMAL)) {
> +			netdev_err(bp->dev, "Error during driver initialization, try unloading/reloading the driver\n");
> +			goto done;
> +		}
> +	}
>   
>   	netif_device_attach(dev);
>   
> +done:
>   	rtnl_unlock();
>   }
>