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Date:   Thu, 29 Sep 2022 11:19:47 -0700
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Message-ID: <20220929181947.62909-1-nhuck@google.com>
Subject: [PATCH v2] net: sparx5: Fix return type of sparx5_port_xmit_impl
From:   Nathan Huckleberry <nhuck@google.com>
To:     kuba@kernel.org
Cc:     Steen.Hegelund@microchip.com, UNGLinuxDriver@microchip.com,
        casper.casan@gmail.com, davem@davemloft.net, edumazet@google.com,
        error27@gmail.com, horatiu.vultur@microchip.com,
        lars.povlsen@microchip.com, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        nathan@kernel.org, ndesaulniers@google.com, netdev@vger.kernel.org,
        nhuck@google.com, pabeni@redhat.com, trix@redhat.com
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Precedence: bulk

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 sparx5_port_xmit_impl 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>
---

Changes v1 -> v2
- Updated header file

 drivers/net/ethernet/microchip/sparx5/sparx5_main.h   | 2 +-
 drivers/net/ethernet/microchip/sparx5/sparx5_packet.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_main.h b/drivers/net/ethernet/microchip/sparx5/sparx5_main.h
index 8b42cad0e49c..7a83222caa73 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_main.h
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_main.h
@@ -305,7 +305,7 @@ struct frame_info {
 void sparx5_xtr_flush(struct sparx5 *sparx5, u8 grp);
 void sparx5_ifh_parse(u32 *ifh, struct frame_info *info);
 irqreturn_t sparx5_xtr_handler(int irq, void *_priv);
-int sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev);
+netdev_tx_t sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev);
 int sparx5_manual_injection_mode(struct sparx5 *sparx5);
 void sparx5_port_inj_timer_setup(struct sparx5_port *port);
 
diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
index 21844beba72d..83c16ca5b30f 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_packet.c
@@ -222,13 +222,13 @@ static int sparx5_inject(struct sparx5 *sparx5,
 	return NETDEV_TX_OK;
 }
 
-int sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev)
+netdev_tx_t sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev)
 {
 	struct net_device_stats *stats = &dev->stats;
 	struct sparx5_port *port = netdev_priv(dev);
 	struct sparx5 *sparx5 = port->sparx5;
 	u32 ifh[IFH_LEN];
-	int ret;
+	netdev_tx_t ret;
 
 	memset(ifh, 0, IFH_LEN * 4);
 	sparx5_set_port_ifh(ifh, port->portno);
-- 
2.38.0.rc1.362.ged0d419d3c-goog