From 6d872df3e3b91532b142de9044e5b4984017a55f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 19 Nov 2021 07:43:32 -0800 Subject: net: annotate accesses to dev->gso_max_segs dev->gso_max_segs is written under RTNL protection, or when the device is not yet visible, but is read locklessly. Add netif_set_gso_max_segs() helper. Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_segs() where we can to better document what is going on. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/8021q/vlan.c | 2 +- net/8021q/vlan_dev.c | 2 +- net/bridge/br_if.c | 2 +- net/core/dev.c | 2 +- net/core/rtnetlink.c | 4 ++-- net/core/sock.c | 3 ++- 6 files changed, 8 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 34c0ffa81e5f..0c00200c9cb2 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -323,7 +323,7 @@ static void vlan_transfer_features(struct net_device *dev, struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev); netif_set_gso_max_size(vlandev, dev->gso_max_size); - vlandev->gso_max_segs = dev->gso_max_segs; + netif_set_gso_max_segs(vlandev, dev->gso_max_segs); if (vlan_hw_offload_capable(dev->features, vlan->vlan_proto)) vlandev->hard_header_len = dev->hard_header_len; diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 208f6845f6dd..e9499a7c19fe 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -574,7 +574,7 @@ static int vlan_dev_init(struct net_device *dev) dev->features |= dev->hw_features | NETIF_F_LLTX; netif_set_gso_max_size(dev, real_dev->gso_max_size); - dev->gso_max_segs = real_dev->gso_max_segs; + netif_set_gso_max_segs(dev, 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"); diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index d3e1c2276551..3915832a03c2 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -526,7 +526,7 @@ static void br_set_gso_limits(struct net_bridge *br) gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs); } netif_set_gso_max_size(br->dev, gso_max_size); - br->dev->gso_max_segs = gso_max_segs; + netif_set_gso_max_segs(br->dev, gso_max_segs); } /* diff --git a/net/core/dev.c b/net/core/dev.c index 9219e319e901..9c4fc8c3f981 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3396,7 +3396,7 @@ static netdev_features_t gso_features_check(const struct sk_buff *skb, { u16 gso_segs = skb_shinfo(skb)->gso_segs; - if (gso_segs > dev->gso_max_segs) + if (gso_segs > READ_ONCE(dev->gso_max_segs)) return features & ~NETIF_F_GSO_MASK; if (!skb_shinfo(skb)->gso_type) { diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 2af8aeeadadf..fd030e02f16d 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2768,7 +2768,7 @@ static int do_setlink(const struct sk_buff *skb, } if (dev->gso_max_segs ^ max_segs) { - dev->gso_max_segs = max_segs; + netif_set_gso_max_segs(dev, max_segs); status |= DO_SETLINK_MODIFIED; } } @@ -3222,7 +3222,7 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname, if (tb[IFLA_GSO_MAX_SIZE]) netif_set_gso_max_size(dev, nla_get_u32(tb[IFLA_GSO_MAX_SIZE])); if (tb[IFLA_GSO_MAX_SEGS]) - dev->gso_max_segs = nla_get_u32(tb[IFLA_GSO_MAX_SEGS]); + netif_set_gso_max_segs(dev, nla_get_u32(tb[IFLA_GSO_MAX_SEGS])); return dev; } diff --git a/net/core/sock.c b/net/core/sock.c index 4418e2a07c34..31a2b79c9b38 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2259,7 +2259,8 @@ void sk_setup_caps(struct sock *sk, struct dst_entry *dst) sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM; /* 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); + /* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */ + max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1); } } sk->sk_gso_max_segs = max_segs; -- cgit v1.2.3