[PATCH net-next v3 1/7] net: team: Annotate reads and writes for mixed lock accessed values

Marc Harvey
2026-04-02T06:24:33Z

The team_port's "index" and the team's "en_port_count" are read in
the hot transmit path, but are only written to when holding the rtnl
lock.

Use READ_ONCE() for all lockless reads of these values, and use
WRITE_ONCE() for all writes.

Signed-off-by: Marc Harvey <marcharvey@google.com>
---
Changes in v3:
- None

Changes in v2:
- None
---
drivers/net/team/team_core.c | 11 ++++++-----
drivers/net/team/team_mode_random.c | 2 +-
include/linux/if_team.h | 4 ++--
3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/net/team/team_core.c b/drivers/net/team/team_core.c
index 566a5d102c23..becd066279a6 100644
--- a/drivers/net/team/team_core.c
+++ b/drivers/net/team/team_core.c
@@ -938,7 +938,8 @@ static void team_port_enable(struct team *team,
{
if (team_port_enabled(port))
return;
- port->index = team->en_port_count++;
+ WRITE_ONCE(port->index, team->en_port_count);
+ WRITE_ONCE(team->en_port_count, team->en_port_count + 1);
hlist_add_head_rcu(&port->hlist,
team_port_index_hash(team, port->index));
team_adjust_ops(team);
@@ -958,7 +959,7 @@ static void __reconstruct_port_hlist(struct team *team, int rm_index)
for (i = rm_index + 1; i < team->en_port_count; i++) {
port = team_get_port_by_index(team, i);
hlist_del_rcu(&port->hlist);
- port->index--;
+ WRITE_ONCE(port->index, port->index - 1);
hlist_add_head_rcu(&port->hlist,
team_port_index_hash(team, port->index));
}
@@ -973,8 +974,8 @@ static void team_port_disable(struct team *team,
team->ops.port_disabled(team, port);
hlist_del_rcu(&port->hlist);
__reconstruct_port_hlist(team, port->index);
- port->index = -1;
- team->en_port_count--;
+ WRITE_ONCE(port->index, -1);
+ WRITE_ONCE(team->en_port_count, team->en_port_count - 1);
team_queue_override_port_del(team, port);
team_adjust_ops(team);
team_lower_state_changed(port);
@@ -1245,7 +1246,7 @@ static int team_port_add(struct team *team, struct net_device *port_dev,
netif_addr_unlock_bh(dev);
}

- port->index = -1;
+ WRITE_ONCE(port->index, -1);
list_add_tail_rcu(&port->list, &team->port_list);
team_port_enable(team, port);
netdev_compute_master_upper_features(dev, true);
diff --git a/drivers/net/team/team_mode_random.c b/drivers/net/team/team_mode_random.c
index 53d0ce34b8ce..169a7bc865b2 100644
--- a/drivers/net/team/team_mode_random.c
+++ b/drivers/net/team/team_mode_random.c
@@ -16,7 +16,7 @@ static bool rnd_transmit(struct team *team, struct sk_buff *skb)
struct team_port *port;
int port_index;

- port_index = get_random_u32_below(team->en_port_count);
+ port_index = get_random_u32_below(READ_ONCE(team->en_port_count));
port = team_get_port_by_index_rcu(team, port_index);
if (unlikely(!port))
goto drop;
diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index ccb5327de26d..06f4d7400c1e 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -77,7 +77,7 @@ static inline struct team_port *team_port_get_rcu(const struct net_device *dev)

static inline bool team_port_enabled(struct team_port *port)
{
- return port->index != -1;
+ return READ_ONCE(port->index) != -1;
}

static inline bool team_port_txable(struct team_port *port)
@@ -272,7 +272,7 @@ static inline struct team_port *team_get_port_by_index_rcu(struct team *team,
struct hlist_head *head = team_port_index_hash(team, port_index);

hlist_for_each_entry_rcu(port, head, hlist)
- if (port->index == port_index)
+ if (READ_ONCE(port->index) == port_index)
return port;
return NULL;
}

--
2.53.0.1185.g05d4b7b318-goog