From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
netdev@vger.kernel.org, Ido Schimmel <idosch@nvidia.com>,
Nikolay Aleksandrov <razor@blackwall.org>,
eric.dumazet@gmail.com, Eric Dumazet <edumazet@google.com>
Subject: [PATCH net-next 11/11] bridge: read p->flags once in br_port_fill_attrs()
Date: Thu, 21 May 2026 13:19:16 +0000 [thread overview]
Message-ID: <20260521131916.3627204-12-edumazet@google.com> (raw)
In-Reply-To: <20260521131916.3627204-1-edumazet@google.com>
We might run br_port_fill_attrs() locklessly in the future.
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
net/bridge/br_netlink.c | 41 +++++++++++++++++++++--------------------
1 file changed, 21 insertions(+), 20 deletions(-)
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index cc485b929d983ee4faf2541b661cad88896d39ed..26d3adec2dcbe5d5492ddf961aa221382ded9125 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -234,7 +234,8 @@ static inline size_t br_nlmsg_size(struct net_device *dev, u32 filter_mask)
static int br_port_fill_attrs(struct sk_buff *skb,
const struct net_bridge_port *p)
{
- u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
+ unsigned long flags = READ_ONCE(p->flags);
+ u8 mode = !!(flags & BR_HAIRPIN_MODE);
struct net_bridge_port *backup_p;
u64 timerval;
@@ -242,23 +243,23 @@ static int br_port_fill_attrs(struct sk_buff *skb,
nla_put_u16(skb, IFLA_BRPORT_PRIORITY, READ_ONCE(p->priority)) ||
nla_put_u32(skb, IFLA_BRPORT_COST, READ_ONCE(p->path_cost)) ||
nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
- nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
+ nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(flags & BR_BPDU_GUARD)) ||
nla_put_u8(skb, IFLA_BRPORT_PROTECT,
- !!(p->flags & BR_ROOT_BLOCK)) ||
+ !!(flags & BR_ROOT_BLOCK)) ||
nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE,
- !!(p->flags & BR_MULTICAST_FAST_LEAVE)) ||
+ !!(flags & BR_MULTICAST_FAST_LEAVE)) ||
nla_put_u8(skb, IFLA_BRPORT_MCAST_TO_UCAST,
- !!(p->flags & BR_MULTICAST_TO_UNICAST)) ||
- nla_put_u8(skb, IFLA_BRPORT_LEARNING, !!(p->flags & BR_LEARNING)) ||
+ !!(flags & BR_MULTICAST_TO_UNICAST)) ||
+ nla_put_u8(skb, IFLA_BRPORT_LEARNING, !!(flags & BR_LEARNING)) ||
nla_put_u8(skb, IFLA_BRPORT_UNICAST_FLOOD,
- !!(p->flags & BR_FLOOD)) ||
+ !!(flags & BR_FLOOD)) ||
nla_put_u8(skb, IFLA_BRPORT_MCAST_FLOOD,
- !!(p->flags & BR_MCAST_FLOOD)) ||
+ !!(flags & BR_MCAST_FLOOD)) ||
nla_put_u8(skb, IFLA_BRPORT_BCAST_FLOOD,
- !!(p->flags & BR_BCAST_FLOOD)) ||
- nla_put_u8(skb, IFLA_BRPORT_PROXYARP, !!(p->flags & BR_PROXYARP)) ||
+ !!(flags & BR_BCAST_FLOOD)) ||
+ nla_put_u8(skb, IFLA_BRPORT_PROXYARP, !!(flags & BR_PROXYARP)) ||
nla_put_u8(skb, IFLA_BRPORT_PROXYARP_WIFI,
- !!(p->flags & BR_PROXYARP_WIFI)) ||
+ !!(flags & BR_PROXYARP_WIFI)) ||
nla_put(skb, IFLA_BRPORT_ROOT_ID, sizeof(struct ifla_bridge_id),
&p->designated_root) ||
nla_put(skb, IFLA_BRPORT_BRIDGE_ID, sizeof(struct ifla_bridge_id),
@@ -272,22 +273,22 @@ static int br_port_fill_attrs(struct sk_buff *skb,
nla_put_u8(skb, IFLA_BRPORT_TOPOLOGY_CHANGE_ACK,
p->topology_change_ack) ||
nla_put_u8(skb, IFLA_BRPORT_CONFIG_PENDING, READ_ONCE(p->config_pending)) ||
- nla_put_u8(skb, IFLA_BRPORT_VLAN_TUNNEL, !!(p->flags &
+ nla_put_u8(skb, IFLA_BRPORT_VLAN_TUNNEL, !!(flags &
BR_VLAN_TUNNEL)) ||
nla_put_u16(skb, IFLA_BRPORT_GROUP_FWD_MASK, p->group_fwd_mask) ||
nla_put_u8(skb, IFLA_BRPORT_NEIGH_SUPPRESS,
- !!(p->flags & BR_NEIGH_SUPPRESS)) ||
- nla_put_u8(skb, IFLA_BRPORT_MRP_RING_OPEN, !!(p->flags &
+ !!(flags & BR_NEIGH_SUPPRESS)) ||
+ nla_put_u8(skb, IFLA_BRPORT_MRP_RING_OPEN, !!(flags &
BR_MRP_LOST_CONT)) ||
nla_put_u8(skb, IFLA_BRPORT_MRP_IN_OPEN,
- !!(p->flags & BR_MRP_LOST_IN_CONT)) ||
- nla_put_u8(skb, IFLA_BRPORT_ISOLATED, !!(p->flags & BR_ISOLATED)) ||
- nla_put_u8(skb, IFLA_BRPORT_LOCKED, !!(p->flags & BR_PORT_LOCKED)) ||
- nla_put_u8(skb, IFLA_BRPORT_MAB, !!(p->flags & BR_PORT_MAB)) ||
+ !!(flags & BR_MRP_LOST_IN_CONT)) ||
+ nla_put_u8(skb, IFLA_BRPORT_ISOLATED, !!(flags & BR_ISOLATED)) ||
+ nla_put_u8(skb, IFLA_BRPORT_LOCKED, !!(flags & BR_PORT_LOCKED)) ||
+ nla_put_u8(skb, IFLA_BRPORT_MAB, !!(flags & BR_PORT_MAB)) ||
nla_put_u8(skb, IFLA_BRPORT_NEIGH_VLAN_SUPPRESS,
- !!(p->flags & BR_NEIGH_VLAN_SUPPRESS)) ||
+ !!(flags & BR_NEIGH_VLAN_SUPPRESS)) ||
nla_put_u8(skb, IFLA_BRPORT_NEIGH_FORWARD_GRAT,
- !!(p->flags & BR_NEIGH_FORWARD_GRAT)))
+ !!(flags & BR_NEIGH_FORWARD_GRAT)))
return -EMSGSIZE;
timerval = br_timer_value(&p->message_age_timer);
--
2.54.0.669.g59709faab0-goog
next prev parent reply other threads:[~2026-05-21 13:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-21 13:19 [PATCH net-next 00/11] bridge: prepare lockless br_port_fill_attrs() (I) Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 01/11] bridge: add a READ_ONCE() in br_timer_value() Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 02/11] bridge: add bridge_flags_bit enum Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 03/11] bridge: use BR_PROMISC_BIT Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 04/11] bridge: use BR_ADMIN_COST_BIT Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 05/11] bridge: provide lockless access to p->path_cost Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 06/11] bridge: provide lockless access to p->designated_cost Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 07/11] bridge: provide lockless access to p->designated_port Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 08/11] bridge: provide lockless access to p->priority Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 09/11] bridge: provide lockless access to p->port_id Eric Dumazet
2026-05-21 13:19 ` [PATCH net-next 10/11] bridge: provide lockless access to p->config_pending Eric Dumazet
2026-05-21 13:19 ` Eric Dumazet [this message]
2026-05-22 8:45 ` [PATCH net-next 00/11] bridge: prepare lockless br_port_fill_attrs() (I) Ido Schimmel
2026-05-22 9:31 ` Eric Dumazet
2026-05-22 9:32 ` Nikolay Aleksandrov
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