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>

diff --git a/drivers/net/ethernet/netronome/nfp/flower/cmsg.c b/drivers/net/ethernet/netronome/nfp/flower/cmsg.c
index f21cf1f..153533c 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/flower/cmsg.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/cmsg.c
@@ -210,6 +210,7 @@ nfp_flower_cmsg_merge_hint_rx(struct nfp_app *app, struct sk_buff *skb)
        unsigned int msg_len = nfp_flower_cmsg_get_data_len(skb);
        struct nfp_flower_cmsg_merge_hint *msg;
        struct nfp_fl_payload *sub_flows[2];
+       struct nfp_flower_priv *priv;
        int err, i, flow_cnt;
 
        msg = nfp_flower_cmsg_get_data(skb);
@@ -228,14 +229,15 @@ nfp_flower_cmsg_merge_hint_rx(struct nfp_app *app, struct sk_buff *skb)
                return;
        }
 
-       rtnl_lock();
+       priv = app->priv;
+       mutex_lock(&priv->nfp_fl_lock);
        for (i = 0; i < flow_cnt; i++) {
                u32 ctx = be32_to_cpu(msg->flow[i].host_ctx);
 
                sub_flows[i] = nfp_flower_get_fl_payload_from_ctx(app, ctx);
                if (!sub_flows[i]) {
                        nfp_flower_cmsg_warn(app, "Invalid flow in merge hint\n");
-                       goto err_rtnl_unlock;
+                       goto err_mutex_unlock;
                }
        }
 
@@ -244,8 +246,8 @@ nfp_flower_cmsg_merge_hint_rx(struct nfp_app *app, struct sk_buff *skb)
        if (err == -ENOMEM)
                nfp_flower_cmsg_warn(app, "Flow merge memory fail.\n");
 
-err_rtnl_unlock:
-       rtnl_unlock();
+err_mutex_unlock:
+       mutex_unlock(&priv->nfp_fl_lock);
 }
 
 static void

diff --git a/drivers/net/ethernet/netronome/nfp/flower/conntrack.c b/drivers/net/ethernet/netronome/nfp/flower/conntrack.c
index 2643c4b..2967bab 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/flower/conntrack.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/conntrack.c
@@ -2131,8 +2131,6 @@ nfp_fl_ct_offload_nft_flow(struct nfp_fl_ct_zone_entry *zt, struct flow_cls_offl
        struct nfp_fl_ct_flow_entry *ct_entry;
        struct netlink_ext_ack *extack = NULL;
 
-       ASSERT_RTNL();
-
        extack = flow->common.extack;
        switch (flow->command) {
        case FLOW_CLS_REPLACE:
@@ -2178,9 +2176,13 @@ int nfp_fl_ct_handle_nft_flow(enum tc_setup_type type, void *type_data, void *cb
 
        switch (type) {
        case TC_SETUP_CLSFLOWER:
-               rtnl_lock();
+               while (!mutex_trylock(&zt->priv->nfp_fl_lock)) {
+                       if (!zt->nft) /* avoid deadlock */
+                               return err;
+                       msleep(20);
+               }
                err = nfp_fl_ct_offload_nft_flow(zt, flow);
-               rtnl_unlock();
+               mutex_unlock(&zt->priv->nfp_fl_lock);
                break;
        default:
                return -EOPNOTSUPP;
@@ -2208,6 +2210,7 @@ int nfp_fl_ct_del_flow(struct nfp_fl_ct_map_entry *ct_map_ent)
        struct nfp_fl_ct_flow_entry *ct_entry;
        struct nfp_fl_ct_zone_entry *zt;
        struct rhashtable *m_table;
+       struct nf_flowtable *nft;
 
        if (!ct_map_ent)
                return -ENOENT;
@@ -2226,8 +2229,12 @@ int nfp_fl_ct_del_flow(struct nfp_fl_ct_map_entry *ct_map_ent)
                if (ct_map_ent->cookie > 0)
                        kfree(ct_map_ent);
 
-               if (!zt->pre_ct_count) {
-                       zt->nft = NULL;
+               if (!zt->pre_ct_count && zt->nft) {
+                       nft = zt->nft;
+                       zt->nft = NULL; /* avoid deadlock */
+                       nf_flow_table_offload_del_cb(nft,
+                                                    nfp_fl_ct_handle_nft_flow,
+                                                    zt);
                        nfp_fl_ct_clean_nft_entries(zt);
                }
                break;

diff --git a/drivers/net/ethernet/netronome/nfp/flower/main.h b/drivers/net/ethernet/netronome/nfp/flower/main.h
index 4037254..2b7c947 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/flower/main.h
+++ b/drivers/net/ethernet/netronome/nfp/flower/main.h
@@ -297,6 +297,7 @@ struct nfp_fl_internal_ports {
  * @predt_list:                List to keep track of decap pretun flows
  * @neigh_table:       Table to keep track of neighbor entries
  * @predt_lock:                Lock to serialise predt/neigh table updates
+ * @nfp_fl_lock:       Lock to protect the flow offload operation
  */
 struct nfp_flower_priv {
        struct nfp_app *app;
@@ -339,6 +340,7 @@ struct nfp_flower_priv {
        struct list_head predt_list;
        struct rhashtable neigh_table;
        spinlock_t predt_lock; /* Lock to serialise predt/neigh table updates */
+       struct mutex nfp_fl_lock; /* Protect the flow operation */
 };
 
 /**

diff --git a/drivers/net/ethernet/netronome/nfp/flower/metadata.c b/drivers/net/ethernet/netronome/nfp/flower/metadata.c
index 0f06ef6..80e4675 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/flower/metadata.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/metadata.c
@@ -528,6 +528,8 @@ int nfp_flower_metadata_init(struct nfp_app *app, u64 host_ctx_count,
        if (err)
                goto err_free_stats_ctx_table;
 
+       mutex_init(&priv->nfp_fl_lock);
+
        err = rhashtable_init(&priv->ct_zone_table, &nfp_zone_table_params);
        if (err)
                goto err_free_merge_table;

diff --git a/drivers/net/ethernet/netronome/nfp/flower/offload.c b/drivers/net/ethernet/netronome/nfp/flower/offload.c
index c153f05..0aceef9 100644 (file)
--- 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);

diff --git a/drivers/net/ethernet/netronome/nfp/flower/qos_conf.c b/drivers/net/ethernet/netronome/nfp/flower/qos_conf.c
index 99052a9..e7180b4 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/flower/qos_conf.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/qos_conf.c
@@ -523,25 +523,31 @@ int nfp_flower_setup_qos_offload(struct nfp_app *app, struct net_device *netdev,
 {
        struct netlink_ext_ack *extack = flow->common.extack;
        struct nfp_flower_priv *fl_priv = app->priv;
+       int ret;
 
        if (!(fl_priv->flower_ext_feats & NFP_FL_FEATS_VF_RLIM)) {
                NL_SET_ERR_MSG_MOD(extack, "unsupported offload: loaded firmware does not support qos rate limit offload");
                return -EOPNOTSUPP;
        }
 
+       mutex_lock(&fl_priv->nfp_fl_lock);
        switch (flow->command) {
        case TC_CLSMATCHALL_REPLACE:
-               return nfp_flower_install_rate_limiter(app, netdev, flow,
-                                                      extack);
+               ret = nfp_flower_install_rate_limiter(app, netdev, flow, extack);
+               break;
        case TC_CLSMATCHALL_DESTROY:
-               return nfp_flower_remove_rate_limiter(app, netdev, flow,
-                                                     extack);
+               ret = nfp_flower_remove_rate_limiter(app, netdev, flow, extack);
+               break;
        case TC_CLSMATCHALL_STATS:
-               return nfp_flower_stats_rate_limiter(app, netdev, flow,
-                                                    extack);
+               ret = nfp_flower_stats_rate_limiter(app, netdev, flow, extack);
+               break;
        default:
-               return -EOPNOTSUPP;
+               ret = -EOPNOTSUPP;
+               break;
        }
+       mutex_unlock(&fl_priv->nfp_fl_lock);
+
+       return ret;
 }
 
 /* Offload tc action, currently only for tc police */