Merge tag 'gcc-plugins-v4.11-rc1' of git://git.kernel.org/pub/scm/lin…

…ux/kernel/git/kees/linux

Pull gcc-plugins updates from Kees Cook:
 "This includes infrastructure updates and the structleak plugin, which
  performs forced initialization of certain structures to avoid possible
  information exposures to userspace.

  Summary:

   - infrastructure updates (gcc-common.h)

   - introduce structleak plugin for forced initialization of some
     structures"

* tag 'gcc-plugins-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  gcc-plugins: Add structleak for more stack initialization
  gcc-plugins: consolidate on PASS_INFO macro
  gcc-plugins: add PASS_INFO and build_const_char_string()

arch/Kconfig

@@ -410,6 +410,28 @@ config GCC_PLUGIN_LATENT_ENTROPY
 	   * https://grsecurity.net/
 	   * https://pax.grsecurity.net/
 
+config GCC_PLUGIN_STRUCTLEAK
+	bool "Force initialization of variables containing userspace addresses"
+	depends on GCC_PLUGINS
+	help
+	  This plugin zero-initializes any structures that containing a
+	  __user attribute. This can prevent some classes of information
+	  exposures.
+
+	  This plugin was ported from grsecurity/PaX. More information at:
+	   * https://grsecurity.net/
+	   * https://pax.grsecurity.net/
+
+config GCC_PLUGIN_STRUCTLEAK_VERBOSE
+	bool "Report forcefully initialized variables"
+	depends on GCC_PLUGIN_STRUCTLEAK
+	depends on !COMPILE_TEST
+	help
+	  This option will cause a warning to be printed each time the
+	  structleak plugin finds a variable it thinks needs to be
+	  initialized. Since not all existing initializers are detected
+	  by the plugin, this can produce false positive warnings.
+
 config HAVE_CC_STACKPROTECTOR
 	bool
 	help

include/linux/compiler.h

@@ -27,7 +27,11 @@ extern void __chk_user_ptr(const volatile void __user *);
 extern void __chk_io_ptr(const volatile void __iomem *);
 # define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
 #else /* __CHECKER__ */
-# define __user
+# ifdef STRUCTLEAK_PLUGIN
+#  define __user __attribute__((user))
+# else
+#  define __user
+# endif
 # define __kernel
 # define __safe
 # define __force

scripts/Makefile.gcc-plugins

@@ -25,6 +25,10 @@ ifdef CONFIG_GCC_PLUGINS
     endif
   endif
 
+  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)	+= -DSTRUCTLEAK_PLUGIN
+
   GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))
 
   export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR

scripts/gcc-plugins/cyc_complexity_plugin.c

@@ -52,12 +52,8 @@ static unsigned int cyc_complexity_execute(void)
 __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
 {
 	const char * const plugin_name = plugin_info->base_name;
-	struct register_pass_info cyc_complexity_pass_info;
 
-	cyc_complexity_pass_info.pass				= make_cyc_complexity_pass();
-	cyc_complexity_pass_info.reference_pass_name		= "ssa";
-	cyc_complexity_pass_info.ref_pass_instance_number	= 1;
-	cyc_complexity_pass_info.pos_op				= PASS_POS_INSERT_AFTER;
+	PASS_INFO(cyc_complexity, "ssa", 1, PASS_POS_INSERT_AFTER);
 
 	if (!plugin_default_version_check(version, &gcc_version)) {
 		error(G_("incompatible gcc/plugin versions"));

scripts/gcc-plugins/gcc-common.h

@@ -26,6 +26,9 @@
 #include "except.h"
 #include "function.h"
 #include "toplev.h"
+#if BUILDING_GCC_VERSION >= 5000
+#include "expr.h"
+#endif
 #include "basic-block.h"
 #include "intl.h"
 #include "ggc.h"
@@ -80,6 +83,9 @@
 #include "diagnostic.h"
 #include "tree-dump.h"
 #include "tree-pass.h"
+#if BUILDING_GCC_VERSION >= 4009
+#include "pass_manager.h"
+#endif
 #include "predict.h"
 #include "ipa-utils.h"
 
@@ -119,20 +125,17 @@
 #include "builtins.h"
 #endif
 
-/* #include "expr.h" where are you... */
-extern rtx emit_move_insn(rtx x, rtx y);
-
 /* missing from basic_block.h... */
-extern void debug_dominance_info(enum cdi_direction dir);
-extern void debug_dominance_tree(enum cdi_direction dir, basic_block root);
+void debug_dominance_info(enum cdi_direction dir);
+void debug_dominance_tree(enum cdi_direction dir, basic_block root);
 
 #if BUILDING_GCC_VERSION == 4006
-extern void debug_gimple_stmt(gimple);
-extern void debug_gimple_seq(gimple_seq);
-extern void print_gimple_seq(FILE *, gimple_seq, int, int);
-extern void print_gimple_stmt(FILE *, gimple, int, int);
-extern void print_gimple_expr(FILE *, gimple, int, int);
-extern void dump_gimple_stmt(pretty_printer *, gimple, int, int);
+void debug_gimple_stmt(gimple);
+void debug_gimple_seq(gimple_seq);
+void print_gimple_seq(FILE *, gimple_seq, int, int);
+void print_gimple_stmt(FILE *, gimple, int, int);
+void print_gimple_expr(FILE *, gimple, int, int);
+void dump_gimple_stmt(pretty_printer *, gimple, int, int);
 #endif
 
 #define __unused __attribute__((__unused__))
@@ -146,6 +149,29 @@ extern void dump_gimple_stmt(pretty_printer *, gimple, int, int);
 /* should come from c-tree.h if only it were installed for gcc 4.5... */
 #define C_TYPE_FIELDS_READONLY(TYPE) TREE_LANG_FLAG_1(TYPE)
 
+static inline tree build_const_char_string(int len, const char *str)
+{
+	tree cstr, elem, index, type;
+
+	cstr = build_string(len, str);
+	elem = build_type_variant(char_type_node, 1, 0);
+	index = build_index_type(size_int(len - 1));
+	type = build_array_type(elem, index);
+	TREE_TYPE(cstr) = type;
+	TREE_CONSTANT(cstr) = 1;
+	TREE_READONLY(cstr) = 1;
+	TREE_STATIC(cstr) = 1;
+	return cstr;
+}
+
+#define PASS_INFO(NAME, REF, ID, POS)		\
+struct register_pass_info NAME##_pass_info = {	\
+	.pass = make_##NAME##_pass(),		\
+	.reference_pass_name = REF,		\
+	.ref_pass_instance_number = ID,		\
+	.pos_op = POS,				\
+}
+
 #if BUILDING_GCC_VERSION == 4005
 #define FOR_EACH_LOCAL_DECL(FUN, I, D)			\
 	for (tree vars = (FUN)->local_decls, (I) = 0;	\
@@ -527,6 +553,8 @@ static inline const greturn *as_a_const_greturn(const_gimple stmt)
 #define section_name_prefix LTO_SECTION_NAME_PREFIX
 #define fatal_error(loc, gmsgid, ...) fatal_error((gmsgid), __VA_ARGS__)
 
+rtx emit_move_insn(rtx x, rtx y);
+
 typedef struct rtx_def rtx_insn;
 
 static inline const char *get_decl_section_name(const_tree decl)
@@ -643,6 +671,11 @@ static inline const greturn *as_a_const_greturn(const_gimple stmt)
 #define NODE_DECL(node) (node)->decl
 #define cgraph_node_name(node) (node)->name()
 #define NODE_IMPLICIT_ALIAS(node) (node)->cpp_implicit_alias
+
+static inline opt_pass *get_pass_for_id(int id)
+{
+	return g->get_passes()->get_pass_for_id(id);
+}
 #endif
 
 #if BUILDING_GCC_VERSION >= 5000 && BUILDING_GCC_VERSION < 6000

scripts/gcc-plugins/latent_entropy_plugin.c

@@ -592,12 +592,6 @@ __visible int plugin_init(struct plugin_name_args *plugin_info,
 	const struct plugin_argument * const argv = plugin_info->argv;
 	int i;
 
-	struct register_pass_info latent_entropy_pass_info;
-
-	latent_entropy_pass_info.pass		= make_latent_entropy_pass();
-	latent_entropy_pass_info.reference_pass_name		= "optimized";
-	latent_entropy_pass_info.ref_pass_instance_number	= 1;
-	latent_entropy_pass_info.pos_op		= PASS_POS_INSERT_BEFORE;
 	static const struct ggc_root_tab gt_ggc_r_gt_latent_entropy[] = {
 		{
 			.base = &latent_entropy_decl,
@@ -609,6 +603,8 @@ __visible int plugin_init(struct plugin_name_args *plugin_info,
 		LAST_GGC_ROOT_TAB
 	};
 
+	PASS_INFO(latent_entropy, "optimized", 1, PASS_POS_INSERT_BEFORE);
+
 	if (!plugin_default_version_check(version, &gcc_version)) {
 		error(G_("incompatible gcc/plugin versions"));
 		return 1;

scripts/gcc-plugins/sancov_plugin.c

@@ -89,7 +89,6 @@ static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data)
 __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
 {
 	int i;
-	struct register_pass_info sancov_plugin_pass_info;
 	const char * const plugin_name = plugin_info->base_name;
 	const int argc = plugin_info->argc;
 	const struct plugin_argument * const argv = plugin_info->argv;
@@ -107,14 +106,11 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gc
 	};
 
 	/* BBs can be split afterwards?? */
-	sancov_plugin_pass_info.pass				= make_sancov_pass();
 #if BUILDING_GCC_VERSION >= 4009
-	sancov_plugin_pass_info.reference_pass_name		= "asan";
+	PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE);
 #else
-	sancov_plugin_pass_info.reference_pass_name		= "nrv";
+	PASS_INFO(sancov, "nrv", 1, PASS_POS_INSERT_BEFORE);
 #endif
-	sancov_plugin_pass_info.ref_pass_instance_number	= 0;
-	sancov_plugin_pass_info.pos_op				= PASS_POS_INSERT_BEFORE;
 
 	if (!plugin_default_version_check(version, &gcc_version)) {
 		error(G_("incompatible gcc/plugin versions"));