Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 29 Sep 2022 11:44:56 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Nathan Huckleberry <nhuck@google.com>
Cc:     Dan Carpenter <error27@gmail.com>, llvm@lists.linux.dev,
        Horatiu Vultur <horatiu.vultur@microchip.com>,
        UNGLinuxDriver@microchip.com,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: lan966x: Fix return type of lan966x_port_xmit
Message-ID: <YzXnqJ+fdogA1GHs@dev-arch.thelio-3990X>
References: <20220929182704.64438-1-nhuck@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220929182704.64438-1-nhuck@google.com>
Precedence: bulk

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
>