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

Nathan Chancellor
2022-09-13T22:35:41Z

On Tue, Sep 13, 2022 at 03:33:24PM -0700, Nathan Chancellor wrote:
> On Mon, Sep 12, 2022 at 02:45:20PM -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>

Sorry, forgot to point out that the prototypes in
drivers/staging/octeon/ethernet-tx.h should be updated as well.

> > ---
> > drivers/staging/octeon/ethernet-tx.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 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;
> > --
> > 2.37.2.789.g6183377224-goog
> >
>