Merge branch 'for-next/gcc-plugin/structleak' into for-next/gcc-plugins

Author: kees

arch/Kconfig

@@ -458,6 +458,13 @@ config GCC_PLUGIN_STRUCTLEAK
 	   * https://grsecurity.net/
 	   * https://pax.grsecurity.net/
 
+config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
+	bool "Force initialize all struct type variables passed by reference"
+	depends on GCC_PLUGIN_STRUCTLEAK
+	help
+	  Zero initialize any struct type local variable that may be passed by
+	  reference without having been initialized.
+
 config GCC_PLUGIN_STRUCTLEAK_VERBOSE
 	bool "Report forcefully initialized variables"
 	depends on GCC_PLUGIN_STRUCTLEAK

scripts/Makefile.gcc-plugins

@@ -27,6 +27,7 @@ ifdef CONFIG_GCC_PLUGINS
 
   gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK)	+= structleak_plugin.so
   gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE)	+= -fplugin-arg-structleak_plugin-verbose
+  gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)	+= -fplugin-arg-structleak_plugin-byref-all
   gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK)	+= -DSTRUCTLEAK_PLUGIN
 
   gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT)	+= randomize_layout_plugin.so

scripts/gcc-plugins/structleak_plugin.c

@@ -16,6 +16,7 @@
  * Options:
  * -fplugin-arg-structleak_plugin-disable
  * -fplugin-arg-structleak_plugin-verbose
+ * -fplugin-arg-structleak_plugin-byref-all
  *
  * Usage:
  * $ # for 4.5/4.6/C based 4.7
@@ -42,6 +43,7 @@ static struct plugin_info structleak_plugin_info = {
 };
 
 static bool verbose;
+static bool byref_all;
 
 static tree handle_user_attribute(tree *node, tree name, tree args, int flags, bool *no_add_attrs)
 {
@@ -150,7 +152,9 @@ static void initialize(tree var)
 	/* these aren't the 0days you're looking for */
 	if (verbose)
 		inform(DECL_SOURCE_LOCATION(var),
-			"userspace variable will be forcibly initialized");
+			"%s variable will be forcibly initialized",
+			(byref_all && TREE_ADDRESSABLE(var)) ? "byref"
+							     : "userspace");
 
 	/* build the initializer expression */
 	initializer = build_constructor(TREE_TYPE(var), NULL);
@@ -190,7 +194,8 @@ static unsigned int structleak_execute(void)
 			continue;
 
 		/* if the type is of interest, examine the variable */
-		if (TYPE_USERSPACE(type))
+		if (TYPE_USERSPACE(type) ||
+		    (byref_all && TREE_ADDRESSABLE(var)))
 			initialize(var);
 	}
 
@@ -232,6 +237,10 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gc
 			verbose = true;
 			continue;
 		}
+		if (!strcmp(argv[i].key, "byref-all")) {
+			byref_all = true;
+			continue;
+		}
 		error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);
 	}