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, 11 insertions, 11 deletions

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 5b43f9b194fc..60fff9a6c53e 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -3569,7 +3569,7 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
 
 	netdev_dbg(netdev, "changing MTU from %d to %d\n",
 		   netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (netif_running(netdev))
 		e1000_up(adapter);
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index bef65ee4c549..220d62fca55d 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -6038,7 +6038,7 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
 	adapter->max_frame_size = max_frame;
 	netdev_dbg(netdev, "changing MTU from %d to %d\n",
 		   netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	pm_runtime_get_sync(netdev->dev.parent);
 
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 2cc7bec0557b..143e37ae88ef 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -2961,7 +2961,7 @@ static int i40e_change_mtu(struct net_device *netdev, int new_mtu)
 
 	netdev_dbg(netdev, "changing MTU from %d to %d\n",
 		   netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 	if (netif_running(netdev))
 		i40e_vsi_reinit_locked(vsi);
 	set_bit(__I40E_CLIENT_SERVICE_REQUESTED, pf->state);
diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index d4f4fd6a1001..d4699c4c535d 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -4296,7 +4296,7 @@ static int iavf_change_mtu(struct net_device *netdev, int new_mtu)
 
 	netdev_dbg(netdev, "changing MTU from %d to %d\n",
 		   netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (netif_running(netdev)) {
 		iavf_schedule_reset(adapter, IAVF_FLAG_RESET_NEEDED);
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 06549dae4cca..125c53c51898 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -7770,7 +7770,7 @@ static int ice_change_mtu(struct net_device *netdev, int new_mtu)
 		return -EBUSY;
 	}
 
-	netdev->mtu = (unsigned int)new_mtu;
+	WRITE_ONCE(netdev->mtu, (unsigned int)new_mtu);
 	err = ice_down_up(vsi);
 	if (err)
 		return err;
diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index 5d3532c27d57..52ceda6306a3 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -2234,7 +2234,7 @@ static int idpf_change_mtu(struct net_device *netdev, int new_mtu)
 	idpf_vport_ctrl_lock(netdev);
 	vport = idpf_netdev_to_vport(netdev);
 
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	err = idpf_initiate_soft_reset(vport, IDPF_SR_MTU_CHANGE);
 
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 74a998fcaa6f..7d9389040e40 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -6641,7 +6641,7 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
 
 	netdev_dbg(netdev, "changing MTU from %d to %d\n",
 		   netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (netif_running(netdev))
 		igb_up(adapter);
diff --git a/drivers/net/ethernet/intel/igbvf/netdev.c b/drivers/net/ethernet/intel/igbvf/netdev.c
index 40ccd24ffc53..7661edd7d0f2 100644
--- a/drivers/net/ethernet/intel/igbvf/netdev.c
+++ b/drivers/net/ethernet/intel/igbvf/netdev.c
@@ -2434,7 +2434,7 @@ static int igbvf_change_mtu(struct net_device *netdev, int new_mtu)
 
 	netdev_dbg(netdev, "changing MTU from %d to %d\n",
 		   netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (netif_running(netdev))
 		igbvf_up(adapter);
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 34c257a51ed1..c30f0f572600 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -5275,7 +5275,7 @@ static int igc_change_mtu(struct net_device *netdev, int new_mtu)
 		igc_down(adapter);
 
 	netdev_dbg(netdev, "changing MTU from %d to %d\n", netdev->mtu, new_mtu);
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (netif_running(netdev))
 		igc_up(adapter);
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 43e7e75ae18c..094653e81b97 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -6847,7 +6847,7 @@ static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu)
 		   netdev->mtu, new_mtu);
 
 	/* must set new MTU before calling down or up */
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (netif_running(netdev))
 		ixgbe_reinit_locked(adapter);
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 3161a13079fe..b938dc06045d 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -4292,7 +4292,7 @@ static int ixgbevf_change_mtu(struct net_device *netdev, int new_mtu)
 	       netdev->mtu, new_mtu);
 
 	/* must set new MTU before calling down or up */
-	netdev->mtu = new_mtu;
+	WRITE_ONCE(netdev->mtu, new_mtu);
 
 	if (netif_running(netdev))
 		ixgbevf_reinit_locked(adapter);