[PATCH AUTOSEL 4.9 09/10] staging: octeon: Fix return type of cvm_oct_xmit and cvm_oct_xmit_pow

[PATCH AUTOSEL 4.9 09/10] staging: octeon: Fix return type of cvm_oct_xmit and cvm_oct_xmit_pow

[Sasha Levin]

From: Nathan Huckleberry <nhuck@google.com>

[ Upstream commit b77599043f00fce9253d0f22522c5d5b521555ce ]

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.

Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@lists.linux.dev
Reported-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Link: https://lore.kernel.org/r/20220914211057.423617-1-nhuck@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 6b4c20872323..e773353ee579 100644
--- a/drivers/staging/octeon/ethernet-tx.c
+++ b/drivers/staging/octeon/ethernet-tx.c
@@ -137,7 +137,7 @@ 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)
 {
 	cvmx_pko_command_word0_t pko_command;
 	union cvmx_buf_ptr hw_buffer;
@@ -523,7 +523,7 @@ int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
 
  * 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 84848e4c1664..65faefc87081 100644
--- a/drivers/staging/octeon/ethernet-tx.h
+++ b/drivers/staging/octeon/ethernet-tx.h
@@ -8,8 +8,8 @@
  * published by the Free Software Foundation.
  */
 
-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);
-- 
2.35.1

Re: [PATCH AUTOSEL 4.9 09/10] staging: octeon: Fix return type of cvm_oct_xmit and cvm_oct_xmit_pow

[Greg Kroah-Hartman]

On Wed, Oct 12, 2022 at 08:27:56PM -0400, Sasha Levin wrote:
> From: Nathan Huckleberry <nhuck@google.com>
> 
> [ Upstream commit b77599043f00fce9253d0f22522c5d5b521555ce ]
> 
> 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.

kCFI showed up in 6.1, so this is not needed in any stable branches,
please drop it from all.

thanks,

greg k-h