Re: [PATCH v2] staging: octeon: Fix return type of cvm_oct_xmit and cvm_oct_xmit_pow

Nathan Chancellor
2022-09-13T23:22:25Z

On Tue, Sep 13, 2022 at 04:04:12PM -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 cvm_oct_xmit and cvm_oct_xmit_pow 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>

>
> Changes v1 -> v2:
> - Update function signatures in ethernet-tx.h.
>
> ---
> drivers/staging/octeon/ethernet-tx.c | 4 ++--
> drivers/staging/octeon/ethernet-tx.h | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/octeon/ethernet-tx.c b/drivers/staging/octeon/ethernet-tx.c
> index 1ad94c5060b5..a36e36701c74 100644
> --- a/drivers/staging/octeon/ethernet-tx.c
> +++ b/drivers/staging/octeon/ethernet-tx.c
> @@ -125,7 +125,7 @@ static void cvm_oct_free_tx_skbs(struct net_device *dev)
> *
> * Returns Always returns NETDEV_TX_OK
> */
> -int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
> +netdev_tx_t cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
> {
> union cvmx_pko_command_word0 pko_command;
> union cvmx_buf_ptr hw_buffer;
> @@ -506,7 +506,7 @@ int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
> * @dev: Device info structure
> * Returns Always returns zero
> */
> -int cvm_oct_xmit_pow(struct sk_buff *skb, struct net_device *dev)
> +netdev_tx_t cvm_oct_xmit_pow(struct sk_buff *skb, struct net_device *dev)
> {
> struct octeon_ethernet *priv = netdev_priv(dev);
> void *packet_buffer;
> diff --git a/drivers/staging/octeon/ethernet-tx.h b/drivers/staging/octeon/ethernet-tx.h
> index 78936e9b33b0..6c524668f65a 100644
> --- a/drivers/staging/octeon/ethernet-tx.h
> +++ b/drivers/staging/octeon/ethernet-tx.h
> @@ -5,8 +5,8 @@
> * Copyright (c) 2003-2007 Cavium Networks
> */
>
> -int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev);
> -int cvm_oct_xmit_pow(struct sk_buff *skb, struct net_device *dev);
> +netdev_tx_t cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev);
> +netdev_tx_t cvm_oct_xmit_pow(struct sk_buff *skb, struct net_device *dev);
> int cvm_oct_transmit_qos(struct net_device *dev, void *work_queue_entry,
> int do_free, int qos);
> void cvm_oct_tx_initialize(void);
> --
> 2.37.2.789.g6183377224-goog
>