Re: [PATCH v2] staging: r8188eu: Fix return type of rtw_xmit_entry

Nathan Chancellor
2022-09-13T23:17:07Z

On Tue, Sep 13, 2022 at 12:33:22PM -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 rtw_xmit_entry 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>

The prototype in drivers/staging/r8188eu/include/xmit_osdep.h should be
updated as well. With that:

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

> Changes v1 -> v2:
> - Rebased onto linux-next/master
>
> ---
> drivers/staging/r8188eu/core/rtw_xmit.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
> index 98864fc55b25..ea13f11b231b 100644
> --- a/drivers/staging/r8188eu/core/rtw_xmit.c
> +++ b/drivers/staging/r8188eu/core/rtw_xmit.c
> @@ -2289,7 +2289,7 @@ static int rtw_mlcst2unicst(struct adapter *padapter, struct sk_buff *skb)
> return true;
> }
>
> -int rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev)
> +netdev_tx_t rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev)
> {
> struct adapter *padapter = (struct adapter *)rtw_netdev_priv(pnetdev);
> struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
> @@ -2323,5 +2323,5 @@ int rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev)
> dev_kfree_skb_any(pkt);
>
> exit:
> - return 0;
> + return NETDEV_TX_OK;
> }
> --
> 2.37.2.789.g6183377224-goog
>