| Message ID | 20201112111150.34361-1-lev@openvpn.net |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
| Series | None | expand |
Am 12.11.2020 um 12:11 schrieb Lev Stipakov: > Commit d3fd65484c781 ("net: core: add dev_sw_netstats_tx_add") has added > function "dev_sw_netstats_tx_add()" to update net device per-cpu TX > stats. > > Use this function instead of own code. While on it, replace > "len" variable with "skb->len". > Using dev_sw_netstats_tx_add() is fine, however you have to keep variable len, see remark in the code. In addition you can replace internal_get_stats() with dev_get_tstats64(). > Signed-off-by: Lev Stipakov <lev@openvpn.net> > --- > net/openvswitch/vport-internal_dev.c | 16 +++++----------- > 1 file changed, 5 insertions(+), 11 deletions(-) > > diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c > index 1e30d8df3ba5..116738d36e02 100644 > --- a/net/openvswitch/vport-internal_dev.c > +++ b/net/openvswitch/vport-internal_dev.c > @@ -33,23 +33,17 @@ static struct internal_dev *internal_dev_priv(struct net_device *netdev) > static netdev_tx_t > internal_dev_xmit(struct sk_buff *skb, struct net_device *netdev) > { > - int len, err; > + int err; > > - len = skb->len; > rcu_read_lock(); > err = ovs_vport_receive(internal_dev_priv(netdev)->vport, skb, NULL); We would have a well-hidden problem here. ovs_vport_receive() calls function ovs_dp_process_packet() that frees the skb under certain circumstances. Note that the skb can be freed even if ovs_vport_receive() returns OK. Using skb->len after calling ovs_vport_receive() could result in a use-after-free therefore. So you have to keep variable len. > rcu_read_unlock(); > > - if (likely(!err)) { > - struct pcpu_sw_netstats *tstats = this_cpu_ptr(netdev->tstats); > - > - u64_stats_update_begin(&tstats->syncp); > - tstats->tx_bytes += len; > - tstats->tx_packets++; > - u64_stats_update_end(&tstats->syncp); > - } else { > + if (likely(!err)) > + dev_sw_netstats_tx_add(netdev, 1, skb->len); > + else > netdev->stats.tx_errors++; > - } > + > return NETDEV_TX_OK; > } > >
diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c index 1e30d8df3ba5..116738d36e02 100644 --- a/net/openvswitch/vport-internal_dev.c +++ b/net/openvswitch/vport-internal_dev.c @@ -33,23 +33,17 @@ static struct internal_dev *internal_dev_priv(struct net_device *netdev) static netdev_tx_t internal_dev_xmit(struct sk_buff *skb, struct net_device *netdev) { - int len, err; + int err; - len = skb->len; rcu_read_lock(); err = ovs_vport_receive(internal_dev_priv(netdev)->vport, skb, NULL); rcu_read_unlock(); - if (likely(!err)) { - struct pcpu_sw_netstats *tstats = this_cpu_ptr(netdev->tstats); - - u64_stats_update_begin(&tstats->syncp); - tstats->tx_bytes += len; - tstats->tx_packets++; - u64_stats_update_end(&tstats->syncp); - } else { + if (likely(!err)) + dev_sw_netstats_tx_add(netdev, 1, skb->len); + else netdev->stats.tx_errors++; - } + return NETDEV_TX_OK; }
Commit d3fd65484c781 ("net: core: add dev_sw_netstats_tx_add") has added function "dev_sw_netstats_tx_add()" to update net device per-cpu TX stats. Use this function instead of own code. While on it, replace "len" variable with "skb->len". Signed-off-by: Lev Stipakov <lev@openvpn.net> --- net/openvswitch/vport-internal_dev.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-)