nfp: flower: avoid rmmod nfp crash issues

When there are CT table entries, and you rmmod nfp, the following
events can happen:

task1：
    nfp_net_pci_remove
          ↓
    nfp_flower_stop->(asynchronous)tcf_ct_flow_table_cleanup_work(3)
          ↓
    nfp_zone_table_entry_destroy(1)

task2：
    nfp_fl_ct_handle_nft_flow(2)

When the execution order is (1)->(2)->(3), it will crash. Therefore, in
the function nfp_fl_ct_del_flow, nf_flow_table_offload_del_cb needs to
be executed synchronously.

At the same time, in order to solve the deadlock problem and the problem
of rtnl_lock sometimes failing, replace rtnl_lock with the private
nfp_fl_lock.

Fixes: 7cc93d888df7 ("nfp: flower-ct: remove callback delete deadlock")
Cc: stable@vger.kernel.org
Signed-off-by: Yanguo Li <yanguo.li@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 6 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/flower/offload.c b/drivers/net/ethernet/netronome/nfp/flower/offload.c
index c153f0575b92..0aceef9fe582 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/offload.c
@@ -1009,8 +1009,6 @@ int nfp_flower_merge_offloaded_flows(struct nfp_app *app,
 	u64 parent_ctx = 0;
 	int err;
 
-	ASSERT_RTNL();
-
 	if (sub_flow1 == sub_flow2 ||
 	    nfp_flower_is_merge_flow(sub_flow1) ||
 	    nfp_flower_is_merge_flow(sub_flow2))
@@ -1727,19 +1725,30 @@ static int
 nfp_flower_repr_offload(struct nfp_app *app, struct net_device *netdev,
 			struct flow_cls_offload *flower)
 {
+	struct nfp_flower_priv *priv = app->priv;
+	int ret;
+
 	if (!eth_proto_is_802_3(flower->common.protocol))
 		return -EOPNOTSUPP;
 
+	mutex_lock(&priv->nfp_fl_lock);
 	switch (flower->command) {
 	case FLOW_CLS_REPLACE:
-		return nfp_flower_add_offload(app, netdev, flower);
+		ret = nfp_flower_add_offload(app, netdev, flower);
+		break;
 	case FLOW_CLS_DESTROY:
-		return nfp_flower_del_offload(app, netdev, flower);
+		ret = nfp_flower_del_offload(app, netdev, flower);
+		break;
 	case FLOW_CLS_STATS:
-		return nfp_flower_get_stats(app, netdev, flower);
+		ret = nfp_flower_get_stats(app, netdev, flower);
+		break;
 	default:
-		return -EOPNOTSUPP;
+		ret = -EOPNOTSUPP;
+		break;
 	}
+	mutex_unlock(&priv->nfp_fl_lock);
+
+	return ret;
 }
 
 static int nfp_flower_setup_tc_block_cb(enum tc_setup_type type,
@@ -1778,6 +1787,7 @@ static int nfp_flower_setup_tc_block(struct net_device *netdev,
 	repr_priv = repr->app_priv;
 	repr_priv->block_shared = f->block_shared;
 	f->driver_block_list = &nfp_block_cb_list;
+	f->unlocked_driver_cb = true;
 
 	switch (f->command) {
 	case FLOW_BLOCK_BIND:
@@ -1876,6 +1886,8 @@ nfp_flower_setup_indr_tc_block(struct net_device *netdev, struct Qdisc *sch, str
 	     nfp_flower_internal_port_can_offload(app, netdev)))
 		return -EOPNOTSUPP;
 
+	f->unlocked_driver_cb = true;
+
 	switch (f->command) {
 	case FLOW_BLOCK_BIND:
 		cb_priv = nfp_flower_indr_block_cb_priv_lookup(app, netdev);