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 <[email protected]> --- 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; } -- 2.53.0.1018.g2bb0e51243-goog
