Changeset e6fc486 in mainline

Timestamp:

2018-11-22T16:55:28Z (5 years ago)

Author:

Jakub Jermar <jakub@…>

Parents:

21d3201

Message:

Fix devman function reference counting

After commit 498ced18a4, create_fun_node() returns a fun pointer with an
implicit reference. Adding an extra reference for creation thus adds a
reference that will never be dropped and the function object will be
leaked.

This commit fixes the reference counting issue and also adds the missing
check to the call to insert_fun_node().

Location:

uspace/srv/devman

Files:

• devtree.c (modified) (1 diff)
• drv_conn.c (modified) (2 diffs)

uspace/srv/devman/devtree.c

@@ -144 +144 @@
         }
 
-        fun_add_ref(fun);
-        insert_fun_node(tree, fun, str_dup(""), NULL);
+        if (!insert_fun_node(tree, fun, str_dup(""), NULL)) {
+                fun_del_ref(fun);       /* fun is destroyed */
+                fibril_rwlock_write_unlock(&tree->rwlock);
+                return false;
+        }
 
         match_id_t *id = create_match_id();

uspace/srv/devman/drv_conn.c

@@ -284 +284 @@
 
         fun_node_t *fun = create_fun_node();
-        /* One reference for creation, one for us */
-        fun_add_ref(fun);
+        /*
+         * Hold a temporary reference while we work with fun. The reference from
+         * create_fun_node() moves to the device tree.
+         */
         fun_add_ref(fun);
         fun->ftype = ftype;
@@ -300 +302 @@
                 fun_busy_unlock(fun);
                 fun_del_ref(fun);
-                delete_fun_node(fun);
+                fun_del_ref(fun);       /* fun is destroyed */
                 async_answer_0(call, ENOMEM);
                 return;