net: annotate writes on dev->mtu from ndo_change_mtu()

Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c94510 ("inet: protect against too small
mtu values.")

We read dev->mtu without holding RTNL in many places,
with READ_ONCE() annotations.

It is time to take care of ndo_change_mtu() methods
to use corresponding WRITE_ONCE()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Simon Horman <horms@kernel.org>
Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

11 files changed, 13 insertions, 13 deletions

diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c
index f0bdc06d253d..f35ae2c88091 100644
--- a/drivers/net/ethernet/marvell/mv643xx_eth.c
+++ b/drivers/net/ethernet/marvell/mv643xx_eth.c
@@ -2562,7 +2562,7 @@ static int mv643xx_eth_change_mtu(struct net_device *dev, int new_mtu)
 {
 	struct mv643xx_eth_private *mp = netdev_priv(dev);
 
-	dev->mtu = new_mtu;
+	WRITE_ONCE(dev->mtu, new_mtu);
 	mv643xx_eth_recalc_skb_size(mp);
 	tx_set_rate(mp, 1000000000, 16777216);
 
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 26bf5d47ba02..41894834fb53 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3861,7 +3861,7 @@ static int mvneta_change_mtu(struct net_device *dev, int mtu)
 		return -EINVAL;
 	}
 
-	dev->mtu = mtu;
+	WRITE_ONCE(dev->mtu, mtu);
 
 	if (!netif_running(dev)) {
 		if (pp->bm_priv)
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 19253a0fb4fe..e91486c48de3 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -1375,7 +1375,7 @@ static int mvpp2_bm_update_mtu(struct net_device *dev, int mtu)
 	}
 
 out_set:
-	dev->mtu = mtu;
+	WRITE_ONCE(dev->mtu, mtu);
 	dev->wanted_features = dev->features;
 
 	netdev_update_features(dev);
diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
index 7c9faa714a10..549436efc204 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
@@ -1096,7 +1096,7 @@ static int octep_change_mtu(struct net_device *netdev, int new_mtu)
 				     true);
 	if (!err) {
 		oct->link_info.mtu = new_mtu;
-		netdev->mtu = new_mtu;
+		WRITE_ONCE(netdev->mtu, new_mtu);
 	}
 
 	return err;
diff --git a/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c
index dd49d0b8b494..7e6771c9cdbb 100644
--- a/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_main.c
@@ -881,7 +881,7 @@ static int octep_vf_change_mtu(struct net_device *netdev, int new_mtu)
 	err = octep_vf_mbox_set_mtu(oct, new_mtu);
 	if (!err) {
 		oct->link_info.mtu = new_mtu;
-		netdev->mtu = new_mtu;
+		WRITE_ONCE(netdev->mtu, new_mtu);
 	}
 	return err;
 }
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
index 14bccff0ee5c..f5bce3e326cc 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
@@ -67,7 +67,7 @@ static int otx2_change_mtu(struct net_device *netdev, int new_mtu)
 
 	netdev_info(netdev, "Changing MTU from %d to %d\n",
 		    netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (if_up)
 		err = otx2_open(netdev);
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_vf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_vf.c
index cf0aa16d7540..99fcc5661674 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_vf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_vf.c
@@ -456,7 +456,7 @@ static int otx2vf_change_mtu(struct net_device *netdev, int new_mtu)
 
 	netdev_info(netdev, "Changing MTU from %d to %d\n",
 		    netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (if_up)
 		err = otx2vf_open(netdev);
diff --git a/drivers/net/ethernet/marvell/prestera/prestera_main.c b/drivers/net/ethernet/marvell/prestera/prestera_main.c
index ba6d53ac7f55..63ae01954dfc 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_main.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_main.c
@@ -489,7 +489,7 @@ static int prestera_port_change_mtu(struct net_device *dev, int mtu)
 	if (err)
 		return err;
 
-	dev->mtu = mtu;
+	WRITE_ONCE(dev->mtu, mtu);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c
index dd6ca2e4fd51..1a59c952aa01 100644
--- a/drivers/net/ethernet/marvell/pxa168_eth.c
+++ b/drivers/net/ethernet/marvell/pxa168_eth.c
@@ -1188,7 +1188,7 @@ static int pxa168_eth_change_mtu(struct net_device *dev, int mtu)
 {
 	struct pxa168_eth_private *pep = netdev_priv(dev);
 
-	dev->mtu = mtu;
+	WRITE_ONCE(dev->mtu, mtu);
 	set_port_config_ext(pep);
 
 	if (!netif_running(dev))
diff --git a/drivers/net/ethernet/marvell/skge.c b/drivers/net/ethernet/marvell/skge.c
index 1b43704baceb..fcfb34561882 100644
--- a/drivers/net/ethernet/marvell/skge.c
+++ b/drivers/net/ethernet/marvell/skge.c
@@ -2905,13 +2905,13 @@ static int skge_change_mtu(struct net_device *dev, int new_mtu)
 	int err;
 
 	if (!netif_running(dev)) {
-		dev->mtu = new_mtu;
+		WRITE_ONCE(dev->mtu, new_mtu);
 		return 0;
 	}
 
 	skge_down(dev);
 
-	dev->mtu = new_mtu;
+	WRITE_ONCE(dev->mtu, new_mtu);
 
 	err = skge_up(dev);
 	if (err)
diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c
index f3f7f4cc27b3..a7a16eac1891 100644
--- a/drivers/net/ethernet/marvell/sky2.c
+++ b/drivers/net/ethernet/marvell/sky2.c
@@ -2384,7 +2384,7 @@ static int sky2_change_mtu(struct net_device *dev, int new_mtu)
 	u32 imask;
 
 	if (!netif_running(dev)) {
-		dev->mtu = new_mtu;
+		WRITE_ONCE(dev->mtu, new_mtu);
 		netdev_update_features(dev);
 		return 0;
 	}
@@ -2407,7 +2407,7 @@ static int sky2_change_mtu(struct net_device *dev, int new_mtu)
 	sky2_rx_stop(sky2);
 	sky2_rx_clean(sky2);
 
-	dev->mtu = new_mtu;
+	WRITE_ONCE(dev->mtu, new_mtu);
 	netdev_update_features(dev);
 
 	mode = DATA_BLIND_VAL(DATA_BLIND_DEF) |	GM_SMOD_VLAN_ENA;