/* * Copyright 2011-2016 by Emese Revfy <re.emese@gmail.com> * Licensed under the GPL v2, or (at your option) v3 * * Homepage: * https://github.com/ephox-gcc-plugins/sancov * * This plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks. * It supports all gcc versions with plugin support (from gcc-4.5 on). * It is based on the commit "Add fuzzing coverage support" by Dmitry Vyukov <dvyukov@google.com>. * * You can read about it more here: *  https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296 *  http://lwn.net/Articles/674854/ *  https://github.com/google/syzkaller *  https://lwn.net/Articles/677764/ * * Usage: * make run */ #include "gcc-common.h" __visible int plugin_is_GPL_compatible; tree sancov_fndecl; static struct plugin_info sancov_plugin_info = {	.version	= "20160402",	.help		= "sancov plugin\n",}; static unsigned int sancov_execute(void){	basic_block bb; 	/* Remove this line when this plugin and kcov will be in the kernel.	if (!strcmp(DECL_NAME_POINTER(current_function_decl), DECL_NAME_POINTER(sancov_fndecl)))		return 0;	*/ 	FOR_EACH_BB_FN(bb, cfun) {		const_gimple stmt;		gcall *gcall;		gimple_stmt_iterator gsi = gsi_after_labels(bb); 		if (gsi_end_p(gsi))			continue; 		stmt = gsi_stmt(gsi);		gcall = as_a_gcall(gimple_build_call(sancov_fndecl, 0));		gimple_set_location(gcall, gimple_location(stmt));		gsi_insert_before(&gsi, gcall, GSI_SAME_STMT);	}	return 0;} #define PASS_NAME sancov #define NO_GATE#define TODO_FLAGS_FINISH TODO_dump_func | TODO_verify_stmts | TODO_update_ssa_no_phi | TODO_verify_flow #include "gcc-generate-gimple-pass.h" static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data){	tree leaf_attr, nothrow_attr;	tree BT_FN_VOID = build_function_type_list(void_type_node, NULL_TREE); 	sancov_fndecl = build_fn_decl("__sanitizer_cov_trace_pc", BT_FN_VOID); 	DECL_ASSEMBLER_NAME(sancov_fndecl);	TREE_PUBLIC(sancov_fndecl) = 1;	DECL_EXTERNAL(sancov_fndecl) = 1;	DECL_ARTIFICIAL(sancov_fndecl) = 1;	DECL_PRESERVE_P(sancov_fndecl) = 1;	DECL_UNINLINABLE(sancov_fndecl) = 1;	TREE_USED(sancov_fndecl) = 1; 	nothrow_attr = tree_cons(get_identifier("nothrow"), NULL, NULL);	decl_attributes(&sancov_fndecl, nothrow_attr, 0);	gcc_assert(TREE_NOTHROW(sancov_fndecl));#if BUILDING_GCC_VERSION > 4005	leaf_attr = tree_cons(get_identifier("leaf"), NULL, NULL);	decl_attributes(&sancov_fndecl, leaf_attr, 0);#endif} __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version){	int i;	const char * const plugin_name = plugin_info->base_name;	const int argc = plugin_info->argc;	const struct plugin_argument * const argv = plugin_info->argv;	bool enable = true; 	static const struct ggc_root_tab gt_ggc_r_gt_sancov[] = {		{			.base = &sancov_fndecl,			.nelt = 1,			.stride = sizeof(sancov_fndecl),			.cb = &gt_ggc_mx_tree_node,			.pchw = &gt_pch_nx_tree_node		},		LAST_GGC_ROOT_TAB	}; 	/* BBs can be split afterwards?? */#if BUILDING_GCC_VERSION >= 4009	PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE);#else	PASS_INFO(sancov, "nrv", 1, PASS_POS_INSERT_BEFORE);#endif 	if (!plugin_default_version_check(version, &gcc_version)) {		error(G_("incompatible gcc/plugin versions"));		return 1;	} 	for (i = 0; i < argc; ++i) {		if (!strcmp(argv[i].key, "no-sancov")) {			enable = false;			continue;		}		error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);	} 	register_callback(plugin_name, PLUGIN_INFO, NULL, &sancov_plugin_info); 	if (!enable)		return 0; #if BUILDING_GCC_VERSION < 6000	register_callback(plugin_name, PLUGIN_START_UNIT, &sancov_start_unit, NULL);	register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL, (void *)&gt_ggc_r_gt_sancov);	register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_pass_info);#endif 	return 0;}