Merge tag 'gcc-plugins-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc-plugins updates from Kees Cook:
 "This adds additional type coverage to the existing structleak plugin
  and adds a large set of selftests to help evaluate stack variable
  zero-initialization coverage.

  That can be used to test whatever instrumentation might be performing
  zero-initialization: either with the structleak plugin or with Clang's
  coming "-ftrivial-auto-var-init=zero" option.

  Summary:

   - Add scalar and array initialization coverage

   - Refactor Kconfig to make options more clear

   - Add self-test module for testing automatic initialization"

* tag 'gcc-plugins-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lib: Introduce test_stackinit module
  gcc-plugins: structleak: Generalize to all variable types

1 files changed, 25 insertions, 11 deletions

diff --git a/scripts/gcc-plugins/structleak_plugin.c b/scripts/gcc-plugins/structleak_plugin.c
index 10292f791e99..e89be8f5c859 100644
--- a/scripts/gcc-plugins/structleak_plugin.c
+++ b/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
  * -fplugin-arg-structleak_plugin-byref-all
  *
  * Usage:
@@ -26,7 +27,6 @@
  * $ gcc -fplugin=./structleak_plugin.so test.c -O2
  *
  * TODO: eliminate redundant initializers
- *       increase type coverage
  */
 
 #include "gcc-common.h"
@@ -37,13 +37,18 @@
 __visible int plugin_is_GPL_compatible;
 
 static struct plugin_info structleak_plugin_info = {
-        .version        = "201607271510vanilla",
+        .version        = "20190125vanilla",
         .help           = "disable\tdo not activate plugin\n"
-                           "verbose\tprint all initialized variables\n",
+                          "byref\tinit structs passed by reference\n"
+                          "byref-all\tinit anything passed by reference\n"
+                          "verbose\tprint all initialized variables\n",
 };
 
+#define BYREF_STRUCT    1
+#define BYREF_ALL       2
+
 static bool verbose;
-static bool byref_all;
+static int byref;
 
 static tree handle_user_attribute(tree *node, tree name, tree args, int flags, bool *no_add_attrs)
 {
@@ -118,6 +123,7 @@ static void initialize(tree var)
         gimple_stmt_iterator gsi;
         tree initializer;
         gimple init_stmt;
+        tree type;
 
         /* this is the original entry bb before the forced split */
         bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun));
@@ -148,11 +154,15 @@ static void initialize(tree var)
         if (verbose)
                 inform(DECL_SOURCE_LOCATION(var),
                         "%s variable will be forcibly initialized",
-                        (byref_all && TREE_ADDRESSABLE(var)) ? "byref"
-                                                             : "userspace");
+                        (byref && TREE_ADDRESSABLE(var)) ? "byref"
+                                                         : "userspace");
 
         /* build the initializer expression */
-        initializer = build_constructor(TREE_TYPE(var), NULL);
+        type = TREE_TYPE(var);
+        if (AGGREGATE_TYPE_P(type))
+                initializer = build_constructor(type, NULL);
+        else
+                initializer = fold_convert(type, integer_zero_node);
 
         /* build the initializer stmt */
         init_stmt = gimple_build_assign(var, initializer);
@@ -184,13 +194,13 @@ static unsigned int structleak_execute(void)
                 if (!auto_var_in_fn_p(var, current_function_decl))
                         continue;
 
-                /* only care about structure types */
-                if (TREE_CODE(type) != RECORD_TYPE && TREE_CODE(type) != UNION_TYPE)
+                /* only care about structure types unless byref-all */
+                if (byref != BYREF_ALL && TREE_CODE(type) != RECORD_TYPE && TREE_CODE(type) != UNION_TYPE)
                         continue;
 
                 /* if the type is of interest, examine the variable */
                 if (TYPE_USERSPACE(type) ||
-                    (byref_all && TREE_ADDRESSABLE(var)))
+                    (byref && TREE_ADDRESSABLE(var)))
                         initialize(var);
         }
 
@@ -232,8 +242,12 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gc
                         verbose = true;
                         continue;
                 }
+                if (!strcmp(argv[i].key, "byref")) {
+                        byref = BYREF_STRUCT;
+                        continue;
+                }
                 if (!strcmp(argv[i].key, "byref-all")) {
-                        byref_all = true;
+                        byref = BYREF_ALL;
                         continue;
                 }
                 error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);