[settings] Avoid memory leak when unregistering autovivified settings blocks

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/core/settings.c b/src/core/settings.c
index b9df5a7a7835382dcecf7441efaf0e4d633ed5a3..9b924bc8d79aca3d4e2d27473dc945a14263a4fd 100644 (file)
--- a/src/core/settings.c
+++ b/src/core/settings.c
@@ -230,6 +230,27 @@ struct generic_settings generic_settings_root = {
 /** Root settings block */
 #define settings_root generic_settings_root.settings
 
+/** Autovivified settings block */
+struct autovivified_settings {
+       /** Reference count */
+       struct refcnt refcnt;
+       /** Generic settings block */
+       struct generic_settings generic;
+};
+
+/**
+ * Free autovivified settings block
+ *
+ * @v refcnt           Reference count
+ */
+static void autovivified_settings_free ( struct refcnt *refcnt ) {
+       struct autovivified_settings *autovivified =
+               container_of ( refcnt, struct autovivified_settings, refcnt );
+
+       generic_settings_clear ( &autovivified->generic.settings );
+       free ( autovivified );
+}
+
 /**
  * Find child named settings block
  *
@@ -264,7 +285,7 @@ static struct settings * find_child_settings ( struct settings *parent,
 static struct settings * autovivify_child_settings ( struct settings *parent,
                                                     const char *name ) {
        struct {
-               struct generic_settings generic;
+               struct autovivified_settings autovivified;
                char name[ strlen ( name ) + 1 /* NUL */ ];
        } *new_child;
        struct settings *settings;
@@ -281,8 +302,11 @@ static struct settings * autovivify_child_settings ( struct settings *parent,
                return NULL;
        }
        memcpy ( new_child->name, name, sizeof ( new_child->name ) );
-       generic_settings_init ( &new_child->generic, NULL );
-       settings = &new_child->generic.settings;
+       ref_init ( &new_child->autovivified.refcnt,
+                  autovivified_settings_free );
+       generic_settings_init ( &new_child->autovivified.generic,
+                               &new_child->autovivified.refcnt );
+       settings = &new_child->autovivified.generic.settings;
        register_settings ( settings, parent, new_child->name );
        return settings;
 }