datapath: Validate lock when handling flow actions.

When reading actions without rcu_read_lock we need to hold the
datapath lock.  This checks that using lockdep.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 796c40c..0205fd2 100644 (file)
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -872,7 +872,9 @@ static int do_put_flow(struct datapath *dp, struct odp_flow_put *uf,
                error = PTR_ERR(new_acts);
                if (IS_ERR(new_acts))
                        goto error;
-               old_acts = rcu_dereference(flow->sf_acts);
+
+               old_acts = rcu_dereference_protected(flow->sf_acts,
+                                                    lockdep_is_held(&dp->mutex));
                if (old_acts->actions_len != new_acts->actions_len ||
                    memcmp(old_acts->actions, new_acts->actions,
                           old_acts->actions_len)) {
@@ -921,7 +923,8 @@ static int put_flow(struct datapath *dp, struct odp_flow_put __user *ufp)
        return 0;
 }
 
-static int do_answer_query(struct sw_flow *flow, u32 query_flags,
+static int do_answer_query(struct datapath *dp, struct sw_flow *flow,
+                          u32 query_flags,
                           struct odp_flow_stats __user *ustats,
                           struct nlattr __user *actions,
                           u32 __user *actions_lenp)
@@ -944,7 +947,8 @@ static int do_answer_query(struct sw_flow *flow, u32 query_flags,
        if (!actions_len)
                return 0;
 
-       sf_acts = rcu_dereference(flow->sf_acts);
+       sf_acts = rcu_dereference_protected(flow->sf_acts,
+                                           lockdep_is_held(&dp->mutex));
        if (put_user(sf_acts->actions_len, actions_lenp) ||
            (actions && copy_to_user(actions, sf_acts->actions,
                                     min(sf_acts->actions_len, actions_len))))
@@ -953,15 +957,15 @@ static int do_answer_query(struct sw_flow *flow, u32 query_flags,
        return 0;
 }
 
-static int answer_query(struct sw_flow *flow, u32 query_flags,
-                       struct odp_flow __user *ufp)
+static int answer_query(struct datapath *dp, struct sw_flow *flow,
+                       u32 query_flags, struct odp_flow __user *ufp)
 {
        struct nlattr __user *actions;
 
        if (get_user(actions, (struct nlattr __user * __user *)&ufp->actions))
                return -EFAULT;
 
-       return do_answer_query(flow, query_flags, 
+       return do_answer_query(dp, flow, query_flags, 
                               &ufp->stats, actions, &ufp->actions_len);
 }
 
@@ -999,7 +1003,7 @@ static int del_flow(struct datapath *dp, struct odp_flow __user *ufp)
        if (IS_ERR(flow))
                return PTR_ERR(flow);
 
-       error = answer_query(flow, 0, ufp);
+       error = answer_query(dp, flow, 0, ufp);
        flow_deferred_free(flow);
        return error;
 }
@@ -1022,7 +1026,7 @@ static int do_query_flows(struct datapath *dp, const struct odp_flowvec *flowvec
                if (!flow_node)
                        error = put_user(ENOENT, &ufp->stats.error);
                else
-                       error = answer_query(flow_cast(flow_node), uf.flags, ufp);
+                       error = answer_query(dp, flow_cast(flow_node), uf.flags, ufp);
                if (error)
                        return -EFAULT;
        }
@@ -1030,6 +1034,7 @@ static int do_query_flows(struct datapath *dp, const struct odp_flowvec *flowvec
 }
 
 struct list_flows_cbdata {
+       struct datapath *dp;
        struct odp_flow __user *uflows;
        u32 n_flows;
        u32 listed_flows;
@@ -1044,7 +1049,7 @@ static int list_flow(struct tbl_node *node, void *cbdata_)
 
        if (copy_to_user(&ufp->key, &flow->key, sizeof flow->key))
                return -EFAULT;
-       error = answer_query(flow, 0, ufp);
+       error = answer_query(cbdata->dp, flow, 0, ufp);
        if (error)
                return error;
 
@@ -1061,6 +1066,7 @@ static int do_list_flows(struct datapath *dp, const struct odp_flowvec *flowvec)
        if (!flowvec->n_flows)
                return 0;
 
+       cbdata.dp = dp;
        cbdata.uflows = (struct odp_flow __user *)flowvec->flows;
        cbdata.n_flows = flowvec->n_flows;
        cbdata.listed_flows = 0;
@@ -1559,7 +1565,8 @@ static int compat_put_flow(struct datapath *dp, struct compat_odp_flow_put __use
        return 0;
 }
 
-static int compat_answer_query(struct sw_flow *flow, u32 query_flags,
+static int compat_answer_query(struct datapath *dp, struct sw_flow *flow,
+                              u32 query_flags,
                               struct compat_odp_flow __user *ufp)
 {
        compat_uptr_t actions;
@@ -1567,7 +1574,7 @@ static int compat_answer_query(struct sw_flow *flow, u32 query_flags,
        if (get_user(actions, &ufp->actions))
                return -EFAULT;
 
-       return do_answer_query(flow, query_flags, &ufp->stats,
+       return do_answer_query(dp, flow, query_flags, &ufp->stats,
                               compat_ptr(actions), &ufp->actions_len);
 }
 
@@ -1584,7 +1591,7 @@ static int compat_del_flow(struct datapath *dp, struct compat_odp_flow __user *u
        if (IS_ERR(flow))
                return PTR_ERR(flow);
 
-       error = compat_answer_query(flow, 0, ufp);
+       error = compat_answer_query(dp, flow, 0, ufp);
        flow_deferred_free(flow);
        return error;
 }
@@ -1609,7 +1616,8 @@ static int compat_query_flows(struct datapath *dp,
                if (!flow_node)
                        error = put_user(ENOENT, &ufp->stats.error);
                else
-                       error = compat_answer_query(flow_cast(flow_node), uf.flags, ufp);
+                       error = compat_answer_query(dp, flow_cast(flow_node),
+                                                   uf.flags, ufp);
                if (error)
                        return -EFAULT;
        }
@@ -1617,6 +1625,7 @@ static int compat_query_flows(struct datapath *dp,
 }
 
 struct compat_list_flows_cbdata {
+       struct datapath *dp;
        struct compat_odp_flow __user *uflows;
        u32 n_flows;
        u32 listed_flows;
@@ -1631,7 +1640,7 @@ static int compat_list_flow(struct tbl_node *node, void *cbdata_)
 
        if (copy_to_user(&ufp->key, &flow->key, sizeof flow->key))
                return -EFAULT;
-       error = compat_answer_query(flow, 0, ufp);
+       error = compat_answer_query(cbdata->dp, flow, 0, ufp);
        if (error)
                return error;
 
@@ -1649,6 +1658,7 @@ static int compat_list_flows(struct datapath *dp,
        if (!n_flows)
                return 0;
 
+       cbdata.dp = dp;
        cbdata.uflows = flows;
        cbdata.n_flows = n_flows;
        cbdata.listed_flows = 0;