From: Eric Dumazet <edumazet@google.com>
Date: Fri, 19 Nov 2021 07:43:31 -0800
Subject: net: annotate accesses to dev->gso_max_size
Patch-mainline: v5.17-rc1
Git-commit: 4b66d2161b8125b6caa6971815e85631cf3cf36f
References: jsc#PED-1565
dev->gso_max_size is written under RTNL protection, or when the device is
not yet visible, but is read locklessly.
Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_size()
where we can to better document what is going on.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/netronome/nfp/nfp_net_repr.c | 2 +-
drivers/net/ethernet/realtek/r8169_main.c | 4 ++--
drivers/net/ethernet/sfc/ef100_nic.c | 2 +-
drivers/net/ipvlan/ipvlan_main.c | 4 ++--
drivers/net/macvlan.c | 4 ++--
drivers/net/veth.c | 2 +-
drivers/net/vxlan.c | 2 +-
include/linux/netdevice.h | 3 ++-
net/8021q/vlan.c | 2 +-
net/8021q/vlan_dev.c | 2 +-
net/bridge/br_if.c | 2 +-
net/core/sock.c | 3 ++-
net/sctp/output.c | 2 +-
13 files changed, 18 insertions(+), 16 deletions(-)
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
@@ -286,7 +286,7 @@ nfp_repr_transfer_features(struct net_de
if (repr->dst->u.port_info.lower_dev != lower)
return;
- netdev->gso_max_size = lower->gso_max_size;
+ netif_set_gso_max_size(netdev, lower->gso_max_size);
netdev->gso_max_segs = lower->gso_max_segs;
netdev_update_features(netdev);
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -5392,11 +5392,11 @@ static int rtl_init_one(struct pci_dev *
*/
if (rtl_chip_supports_csum_v2(tp)) {
dev->hw_features |= NETIF_F_SG | NETIF_F_TSO | NETIF_F_TSO6;
- dev->gso_max_size = RTL_GSO_MAX_SIZE_V2;
+ netif_set_gso_max_size(dev, RTL_GSO_MAX_SIZE_V2);
dev->gso_max_segs = RTL_GSO_MAX_SEGS_V2;
} else {
dev->hw_features |= NETIF_F_SG | NETIF_F_TSO;
- dev->gso_max_size = RTL_GSO_MAX_SIZE_V1;
+ netif_set_gso_max_size(dev, RTL_GSO_MAX_SIZE_V1);
dev->gso_max_segs = RTL_GSO_MAX_SEGS_V1;
}
--- a/drivers/net/ethernet/sfc/ef100_nic.c
+++ b/drivers/net/ethernet/sfc/ef100_nic.c
@@ -996,7 +996,7 @@ static int ef100_process_design_param(st
return 0;
case ESE_EF100_DP_GZ_TSO_MAX_PAYLOAD_LEN:
nic_data->tso_max_payload_len = min_t(u64, reader->value, GSO_MAX_SIZE);
- efx->net_dev->gso_max_size = nic_data->tso_max_payload_len;
+ netif_set_gso_max_size(efx->net_dev, nic_data->tso_max_payload_len);
return 0;
case ESE_EF100_DP_GZ_TSO_MAX_PAYLOAD_NUM_SEGS:
nic_data->tso_max_payload_num_segs = min_t(u64, reader->value, 0xffff);
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -140,7 +140,7 @@ static int ipvlan_init(struct net_device
dev->vlan_features = phy_dev->vlan_features & IPVLAN_FEATURES;
dev->vlan_features |= IPVLAN_ALWAYS_ON_OFLOADS;
dev->hw_enc_features |= dev->features;
- dev->gso_max_size = phy_dev->gso_max_size;
+ netif_set_gso_max_size(dev, phy_dev->gso_max_size);
dev->gso_max_segs = phy_dev->gso_max_segs;
dev->hard_header_len = phy_dev->hard_header_len;
@@ -762,7 +762,7 @@ static int ipvlan_device_event(struct no
case NETDEV_FEAT_CHANGE:
list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
- ipvlan->dev->gso_max_size = dev->gso_max_size;
+ netif_set_gso_max_size(ipvlan->dev, dev->gso_max_size);
ipvlan->dev->gso_max_segs = dev->gso_max_segs;
netdev_update_features(ipvlan->dev);
}
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -899,7 +899,7 @@ static int macvlan_init(struct net_devic
dev->vlan_features = lowerdev->vlan_features & MACVLAN_FEATURES;
dev->vlan_features |= ALWAYS_ON_OFFLOADS;
dev->hw_enc_features |= dev->features;
- dev->gso_max_size = lowerdev->gso_max_size;
+ netif_set_gso_max_size(dev, lowerdev->gso_max_size);
dev->gso_max_segs = lowerdev->gso_max_segs;
dev->hard_header_len = lowerdev->hard_header_len;
macvlan_set_lockdep_class(dev);
@@ -1747,7 +1747,7 @@ static int macvlan_device_event(struct n
break;
case NETDEV_FEAT_CHANGE:
list_for_each_entry(vlan, &port->vlans, list) {
- vlan->dev->gso_max_size = dev->gso_max_size;
+ netif_set_gso_max_size(vlan->dev, dev->gso_max_size);
vlan->dev->gso_max_segs = dev->gso_max_segs;
netdev_update_features(vlan->dev);
}
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1514,7 +1514,7 @@ static int veth_newlink(struct net *src_
if (ifmp && (dev->ifindex != 0))
peer->ifindex = ifmp->ifi_index;
- peer->gso_max_size = dev->gso_max_size;
+ netif_set_gso_max_size(peer, dev->gso_max_size);
peer->gso_max_segs = dev->gso_max_segs;
err = register_netdevice(peer);
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -3811,7 +3811,7 @@ static void vxlan_config_apply(struct ne
if (lowerdev) {
dst->remote_ifindex = conf->remote_ifindex;
- dev->gso_max_size = lowerdev->gso_max_size;
+ netif_set_gso_max_size(dev, lowerdev->gso_max_size);
dev->gso_max_segs = lowerdev->gso_max_segs;
needed_headroom = lowerdev->hard_header_len;
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4735,7 +4735,8 @@ static inline bool netif_needs_gso(struc
static inline void netif_set_gso_max_size(struct net_device *dev,
unsigned int size)
{
- dev->gso_max_size = size;
+ /* dev->gso_max_size is read locklessly from sk_setup_caps() */
+ WRITE_ONCE(dev->gso_max_size, size);
}
static inline void skb_gso_error_unwind(struct sk_buff *skb, __be16 protocol,
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -322,7 +322,7 @@ static void vlan_transfer_features(struc
{
struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);
- vlandev->gso_max_size = dev->gso_max_size;
+ netif_set_gso_max_size(vlandev, dev->gso_max_size);
vlandev->gso_max_segs = dev->gso_max_segs;
if (vlan_hw_offload_capable(dev->features, vlan->vlan_proto))
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -573,7 +573,7 @@ static int vlan_dev_init(struct net_devi
NETIF_F_ALL_FCOE;
dev->features |= dev->hw_features | NETIF_F_LLTX;
- dev->gso_max_size = real_dev->gso_max_size;
+ netif_set_gso_max_size(dev, real_dev->gso_max_size);
dev->gso_max_segs = real_dev->gso_max_segs;
if (dev->features & NETIF_F_VLAN_FEATURES)
netdev_warn(real_dev, "VLAN features are set incorrectly. Q-in-Q configurations may not work correctly.\n");
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -527,7 +527,7 @@ static void br_set_gso_limits(struct net
gso_max_size = min(gso_max_size, p->dev->gso_max_size);
gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs);
}
- br->dev->gso_max_size = gso_max_size;
+ netif_set_gso_max_size(br->dev, gso_max_size);
br->dev->gso_max_segs = gso_max_segs;
}
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2159,7 +2159,8 @@ void sk_setup_caps(struct sock *sk, stru
sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
} else {
sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
- sk->sk_gso_max_size = dst->dev->gso_max_size;
+ /* pairs with the WRITE_ONCE() in netif_set_gso_max_size() */
+ sk->sk_gso_max_size = READ_ONCE(dst->dev->gso_max_size);
max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
}
}
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -134,7 +134,7 @@ void sctp_packet_config(struct sctp_pack
dst_hold(tp->dst);
sk_setup_caps(sk, tp->dst);
}
- packet->max_size = sk_can_gso(sk) ? tp->dst->dev->gso_max_size
+ packet->max_size = sk_can_gso(sk) ? READ_ONCE(tp->dst->dev->gso_max_size)
: asoc->pathmtu;
rcu_read_unlock();
}