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Date:   Thu, 29 Sep 2022 11:14:11 -0700
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Message-ID: <20220929181411.61331-1-nhuck@google.com>
Subject: [PATCH v2] net: mana: Fix return type of mana_start_xmit
From:   Nathan Huckleberry <nhuck@google.com>
To:     kuba@kernel.org
Cc:     davem@davemloft.net, decui@microsoft.com, edumazet@google.com,
        error27@gmail.com, haiyangz@microsoft.com, kys@microsoft.com,
        linux-hyperv@vger.kernel.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,
        sthemmin@microsoft.com, trix@redhat.com, wei.liu@kernel.org
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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 mana_start_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: Dexuan Cui <decui@microsoft.com>
---

Changes v1 -> v2
- Update header file

 drivers/net/ethernet/microsoft/mana/mana_en.c | 2 +-
 include/net/mana/mana.h                       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 7ca313c7b7b3..a3df5678bb4f 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -141,7 +141,7 @@ static int mana_map_skb(struct sk_buff *skb, struct mana_port_context *apc,
 	return -ENOMEM;
 }
 
-int mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
 	enum mana_tx_pkt_format pkt_fmt = MANA_SHORT_PKT_FMT;
 	struct mana_port_context *apc = netdev_priv(ndev);
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 20212ffeefb9..3bb579962a14 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -390,7 +390,7 @@ struct mana_port_context {
 	struct mana_ethtool_stats eth_stats;
 };
 
-int mana_start_xmit(struct sk_buff *skb, struct net_device *ndev);
+netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev);
 int mana_config_rss(struct mana_port_context *ac, enum TRI_STATE rx,
 		    bool update_hash, bool update_tab);
 
-- 
2.38.0.rc1.362.ged0d419d3c-goog