[PATCH 5.1 008/122] nfp: flower: add rcu locks when accessing netdev for tunnels

Greg Kroah-Hartman
2019-05-23T19:26:46Z

From: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>

[ Upstream commit cb07d915bf278a7a3938b983bbcb4921366b5eff ]

Add rcu locks when accessing netdev when processing route request
and tunnel keep alive messages received from hardware.

Fixes: 8e6a9046b66a ("nfp: flower vxlan neighbour offload")
Fixes: 856f5b135758 ("nfp: flower vxlan neighbour keep-alive")
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c | 17 ++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

--- a/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
@@ -168,6 +168,7 @@ void nfp_tunnel_keep_alive(struct nfp_ap
return;
}

+ rcu_read_lock();
for (i = 0; i < count; i++) {
ipv4_addr = payload->tun_info[i].ipv4;
port = be32_to_cpu(payload->tun_info[i].egress_port);
@@ -183,6 +184,7 @@ void nfp_tunnel_keep_alive(struct nfp_ap
neigh_event_send(n, NULL);
neigh_release(n);
}
+ rcu_read_unlock();
}

static int
@@ -366,9 +368,10 @@ void nfp_tunnel_request_route(struct nfp

payload = nfp_flower_cmsg_get_data(skb);

+ rcu_read_lock();
netdev = nfp_app_repr_get(app, be32_to_cpu(payload->ingress_port));
if (!netdev)
- goto route_fail_warning;
+ goto fail_rcu_unlock;

flow.daddr = payload->ipv4_addr;
flow.flowi4_proto = IPPROTO_UDP;
@@ -378,21 +381,23 @@ void nfp_tunnel_request_route(struct nfp
rt = ip_route_output_key(dev_net(netdev), &flow);
err = PTR_ERR_OR_ZERO(rt);
if (err)
- goto route_fail_warning;
+ goto fail_rcu_unlock;
#else
- goto route_fail_warning;
+ goto fail_rcu_unlock;
#endif

/* Get the neighbour entry for the lookup */
n = dst_neigh_lookup(&rt->dst, &flow.daddr);
ip_rt_put(rt);
if (!n)
- goto route_fail_warning;
- nfp_tun_write_neigh(n->dev, app, &flow, n, GFP_KERNEL);
+ goto fail_rcu_unlock;
+ nfp_tun_write_neigh(n->dev, app, &flow, n, GFP_ATOMIC);
neigh_release(n);
+ rcu_read_unlock();
return;

-route_fail_warning:
+fail_rcu_unlock:
+ rcu_read_unlock();
nfp_flower_cmsg_warn(app, "Requested route not found.\n");
}