nfp: flower: avoid taking mutex in atomic context

A mutex may sleep, which is not permitted in atomic context.
Avoid a case where this may arise by moving the to
nfp_flower_lag_get_info_from_netdev() in nfp_tun_write_neigh() spinlock.

Fixes: abc210952af7 ("nfp: flower: tunnel neigh support bond offload")
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Yanguo Li <yanguo.li@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230131080313.2076060-1-simon.horman@corigine.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c b/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
index a8678d5612eeaf80c2b75290330b11661f1256cd..060a77f2265d9a12e0c675a1a43e9f06ba95a1b2 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
@@ -460,6 +460,7 @@ nfp_tun_write_neigh(struct net_device *netdev, struct nfp_app *app,
                            sizeof(struct nfp_tun_neigh_v4);
        unsigned long cookie = (unsigned long)neigh;
        struct nfp_flower_priv *priv = app->priv;
+       struct nfp_tun_neigh_lag lag_info;
        struct nfp_neigh_entry *nn_entry;
        u32 port_id;
        u8 mtype;
@@ -468,6 +469,11 @@ nfp_tun_write_neigh(struct net_device *netdev, struct nfp_app *app,
        if (!port_id)
                return;
 
+       if ((port_id & NFP_FL_LAG_OUT) == NFP_FL_LAG_OUT) {
+               memset(&lag_info, 0, sizeof(struct nfp_tun_neigh_lag));
+               nfp_flower_lag_get_info_from_netdev(app, netdev, &lag_info);
+       }
+
        spin_lock_bh(&priv->predt_lock);
        nn_entry = rhashtable_lookup_fast(&priv->neigh_table, &cookie,
                                          neigh_table_params);
@@ -515,7 +521,7 @@ nfp_tun_write_neigh(struct net_device *netdev, struct nfp_app *app,
                neigh_ha_snapshot(common->dst_addr, neigh, netdev);
 
                if ((port_id & NFP_FL_LAG_OUT) == NFP_FL_LAG_OUT)
-                       nfp_flower_lag_get_info_from_netdev(app, netdev, lag);
+                       memcpy(lag, &lag_info, sizeof(struct nfp_tun_neigh_lag));
                common->port_id = cpu_to_be32(port_id);
 
                if (rhashtable_insert_fast(&priv->neigh_table,