Re: [PATCH v2] vfio: Use WARN_ON for low-probability allocation failure issue in vfio_pci_bus_notifier

[Alex Williamson]

On Mon, 15 Jan 2024 14:34:34 +0800
Kunwu Chan <chentao@xxxxxxxxxx> wrote:

> kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.
> 
> This is a blocking notifier callback, so errno isn't a proper return
> value. Use WARN_ON to small allocation failures.
> 
> Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
> ---
> v2: Use WARN_ON instead of return errno
> ---
>  drivers/vfio/pci/vfio_pci_core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index 1cbc990d42e0..61aa19666050 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -2047,6 +2047,7 @@ static int vfio_pci_bus_notifier(struct notifier_block *nb,
>  			 pci_name(pdev));
>  		pdev->driver_override = kasprintf(GFP_KERNEL, "%s",
>  						  vdev->vdev.ops->name);
> +		WARN_ON(!pdev->driver_override);
>  	} else if (action == BUS_NOTIFY_BOUND_DRIVER &&
>  		   pdev->is_virtfn && physfn == vdev->pdev) {
>  		struct pci_driver *drv = pci_dev_driver(pdev);

Applied to vfio next branch for v6.9.  Thanks,

Alex