Re: [PATCH] net: lan966x: Fix return type of lan966x_port_xmit

Nathan Chancellor
2022-09-29T18:45:58Z

On Thu, Sep 29, 2022 at 11:27:03AM -0700, Nathan Huckleberry wrote:
> The ndo_start_xmit field in net_device_ops is expected to be of type
> netdev_tx_t (*ndo_start_xmit)(struct sk_buff *skb, struct net_device *dev).
>
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition.
>
> The return type of lan966x_port_xmit should be changed from int to
> netdev_tx_t.
>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Cc: llvm@lists.linux.dev
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> drivers/net/ethernet/microchip/lan966x/lan966x_main.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
> index b98d37c76edb..be2fd030cccb 100644
> --- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
> +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
> @@ -344,7 +344,8 @@ static void lan966x_ifh_set_timestamp(void *ifh, u64 timestamp)
> IFH_POS_TIMESTAMP, IFH_LEN * 4, PACK, 0);
> }
>
> -static int lan966x_port_xmit(struct sk_buff *skb, struct net_device *dev)
> +static netdev_tx_t lan966x_port_xmit(struct sk_buff *skb,
> + struct net_device *dev)
> {
> struct lan966x_port *port = netdev_priv(dev);
> struct lan966x *lan966x = port->lan966x;
> --
> 2.38.0.rc1.362.ged0d419d3c-goog
>