graph: fix crash on alias in prio tree

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/graph.c b/graph.c
index 84bc9f9b3e83bd75c195340870aac008af4d57fe..0dae510afe8186b5e2b1cf76a1ad89573dc61643 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -707,6 +707,7 @@ static void graph_label_add_value(struct graph_label *i, void *value,
                double yval = gety(x);
                double miny = yval / TOOLTIP_DELTA;
                double maxy = yval * TOOLTIP_DELTA;
+               struct prio_tree_node *ret;
 
                INIT_PRIO_TREE_NODE(&x->node);
                x->node.start = miny;
@@ -714,8 +715,16 @@ static void graph_label_add_value(struct graph_label *i, void *value,
                if (x->node.last == x->node.start)
                        x->node.last++;
 
-               prio_tree_insert(&i->prio_tree, &x->node);
-               i->tooltip_count++;
+               /*
+                * If ret != &x->node, we have an alias. Since the values
+                * should be identical, we can drop it
+                */
+               ret = prio_tree_insert(&i->prio_tree, &x->node);
+               if (ret != &x->node) {
+                       free(x->tooltip);
+                       x->tooltip = NULL;
+               } else
+                       i->tooltip_count++;
        }
 
        if (i->parent->per_label_limit != -1 &&