Re: [PATCH] net: ethernet: ti: davinci_emac: Fix return type of emac_dev_xmit

From: Nathan Chancellor
Date: Tue Sep 13 2022 - 18:30:30 EST


On Mon, Sep 12, 2022 at 12:50:19PM -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 emac_dev_xmit should be changed from int to
> netdev_tx_t.
>
> Reported-by: Dan Carpenter <error27@xxxxxxxxx>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Cc: llvm@xxxxxxxxxxxxxxx
> Signed-off-by: Nathan Huckleberry <nhuck@xxxxxxxxxx>

Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>

> ---
> drivers/net/ethernet/ti/davinci_emac.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
> index 2a3e4e842fa5..e203a5984f03 100644
> --- a/drivers/net/ethernet/ti/davinci_emac.c
> +++ b/drivers/net/ethernet/ti/davinci_emac.c
> @@ -949,7 +949,7 @@ static void emac_tx_handler(void *token, int len, int status)
> *
> * Returns success(NETDEV_TX_OK) or error code (typically out of desc's)
> */
> -static int emac_dev_xmit(struct sk_buff *skb, struct net_device *ndev)
> +static netdev_tx_t emac_dev_xmit(struct sk_buff *skb, struct net_device *ndev)
> {
> struct device *emac_dev = &ndev->dev;
> int ret_code;
> --
> 2.37.2.789.g6183377224-goog
>