Re: [PATCH 1/2] PCI: endpoint: Clean up error handling in vpci_scan_bus()

[Ilpo Järvinen]

On Mon, 10 Jun 2024, Dan Carpenter wrote:

> Smatch complains about inconsistent NULL checking in vpci_scan_bus():
> 
>     drivers/pci/endpoint/functions/pci-epf-vntb.c:1024 vpci_scan_bus()
>     error: we previously assumed 'vpci_bus' could be null (see line 1021)
> 
> Instead of printing an error message and then crashing we should return
> an error code and clean up.  Also the NULL check is reversed so it
> prints an error for success instead of failure.
> 
> Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
>  drivers/pci/endpoint/functions/pci-epf-vntb.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index 8e779eecd62d..7f05a44e9a9f 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -1018,8 +1018,10 @@ static int vpci_scan_bus(void *sysdata)
>  	struct epf_ntb *ndev = sysdata;
>  
>  	vpci_bus = pci_scan_bus(ndev->vbus_number, &vpci_ops, sysdata);
> -	if (vpci_bus)
> -		pr_err("create pci bus\n");
> +	if (!vpci_bus) {
> +		pr_err("create pci bus failed\n");
> +		return -EINVAL;
> +	}
>  
>  	pci_bus_add_devices(vpci_bus);
>  
> @@ -1338,10 +1340,14 @@ static int epf_ntb_bind(struct pci_epf *epf)
>  		goto err_bar_alloc;
>  	}
>  
> -	vpci_scan_bus(ntb);
> +	ret = vpci_scan_bus(ntb);
> +	if (ret)
> +		goto err_unregister;
>  
>  	return 0;
>  
> +err_unregister:
> +	pci_unregister_driver(&vntb_pci_driver);
>  err_bar_alloc:
>  	epf_ntb_config_spad_bar_free(ntb);

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>


-- 
 i.