1/*
  2 * Copyright 2011-2016 by Emese Revfy <re.emese@gmail.com>
  3 * Licensed under the GPL v2, or (at your option) v3
  4 *
  5 * Homepage:
  6 * https://github.com/ephox-gcc-plugins/sancov
  7 *
  8 * This plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks.
  9 * It supports all gcc versions with plugin support (from gcc-4.5 on).
 10 * It is based on the commit "Add fuzzing coverage support" by Dmitry Vyukov <dvyukov@google.com>.
 11 *
 12 * You can read about it more here:
 13 *  https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296
 14 *  http://lwn.net/Articles/674854/
 15 *  https://github.com/google/syzkaller
 16 *  https://lwn.net/Articles/677764/
 17 *
 18 * Usage:
 19 * make run
 20 */
 21
 22#include "gcc-common.h"
 23
 24__visible int plugin_is_GPL_compatible;
 25
 26tree sancov_fndecl;
 27
 28static struct plugin_info sancov_plugin_info = {
 29	.version	= "20160402",
 30	.help		= "sancov plugin\n",
 31};
 32
 33static unsigned int sancov_execute(void)
 34{
 35	basic_block bb;
 36
 37	/* Remove this line when this plugin and kcov will be in the kernel.
 38	if (!strcmp(DECL_NAME_POINTER(current_function_decl), DECL_NAME_POINTER(sancov_fndecl)))
 39		return 0;
 40	*/
 41
 42	FOR_EACH_BB_FN(bb, cfun) {
 43		const_gimple stmt;
 44		gcall *gcall;
 45		gimple_stmt_iterator gsi = gsi_after_labels(bb);
 46
 47		if (gsi_end_p(gsi))
 48			continue;
 49
 50		stmt = gsi_stmt(gsi);
 51		gcall = as_a_gcall(gimple_build_call(sancov_fndecl, 0));
 52		gimple_set_location(gcall, gimple_location(stmt));
 53		gsi_insert_before(&gsi, gcall, GSI_SAME_STMT);
 54	}
 55	return 0;
 56}
 57
 58#define PASS_NAME sancov
 59
 60#define NO_GATE
 61#define TODO_FLAGS_FINISH TODO_dump_func | TODO_verify_stmts | TODO_update_ssa_no_phi | TODO_verify_flow
 62
 63#include "gcc-generate-gimple-pass.h"
 64
 65static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data)
 66{
 67	tree leaf_attr, nothrow_attr;
 68	tree BT_FN_VOID = build_function_type_list(void_type_node, NULL_TREE);
 69
 70	sancov_fndecl = build_fn_decl("__sanitizer_cov_trace_pc", BT_FN_VOID);
 71
 72	DECL_ASSEMBLER_NAME(sancov_fndecl);
 73	TREE_PUBLIC(sancov_fndecl) = 1;
 74	DECL_EXTERNAL(sancov_fndecl) = 1;
 75	DECL_ARTIFICIAL(sancov_fndecl) = 1;
 76	DECL_PRESERVE_P(sancov_fndecl) = 1;
 77	DECL_UNINLINABLE(sancov_fndecl) = 1;
 78	TREE_USED(sancov_fndecl) = 1;
 79
 80	nothrow_attr = tree_cons(get_identifier("nothrow"), NULL, NULL);
 81	decl_attributes(&sancov_fndecl, nothrow_attr, 0);
 82	gcc_assert(TREE_NOTHROW(sancov_fndecl));
 83#if BUILDING_GCC_VERSION > 4005
 84	leaf_attr = tree_cons(get_identifier("leaf"), NULL, NULL);
 85	decl_attributes(&sancov_fndecl, leaf_attr, 0);
 86#endif
 87}
 88
 89__visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
 90{
 91	int i;
 92	const char * const plugin_name = plugin_info->base_name;
 93	const int argc = plugin_info->argc;
 94	const struct plugin_argument * const argv = plugin_info->argv;
 95	bool enable = true;
 96
 97	static const struct ggc_root_tab gt_ggc_r_gt_sancov[] = {
 98		{
 99			.base = &sancov_fndecl,
100			.nelt = 1,
101			.stride = sizeof(sancov_fndecl),
102			.cb = &gt_ggc_mx_tree_node,
103			.pchw = &gt_pch_nx_tree_node
104		},
105		LAST_GGC_ROOT_TAB
106	};
107
108	/* BBs can be split afterwards?? */
109#if BUILDING_GCC_VERSION >= 4009
110	PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE);
111#else
112	PASS_INFO(sancov, "nrv", 1, PASS_POS_INSERT_BEFORE);
113#endif
114
115	if (!plugin_default_version_check(version, &gcc_version)) {
116		error(G_("incompatible gcc/plugin versions"));
117		return 1;
118	}
119
120	for (i = 0; i < argc; ++i) {
121		if (!strcmp(argv[i].key, "no-sancov")) {
122			enable = false;
123			continue;
124		}
125		error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);
126	}
127
128	register_callback(plugin_name, PLUGIN_INFO, NULL, &sancov_plugin_info);
129
130	if (!enable)
131		return 0;
132
133#if BUILDING_GCC_VERSION < 6000
134	register_callback(plugin_name, PLUGIN_START_UNIT, &sancov_start_unit, NULL);
135	register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL, (void *)&gt_ggc_r_gt_sancov);
136	register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_pass_info);
137#endif
138
139	return 0;
140}

  1/*
  2 * Copyright 2011-2016 by Emese Revfy <re.emese@gmail.com>
  3 * Licensed under the GPL v2, or (at your option) v3
  4 *
  5 * Homepage:
  6 * https://github.com/ephox-gcc-plugins/sancov
  7 *
  8 * This plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks.
  9 * It supports all gcc versions with plugin support (from gcc-4.5 on).
 10 * It is based on the commit "Add fuzzing coverage support" by Dmitry Vyukov <dvyukov@google.com>.
 11 *
 12 * You can read about it more here:
 13 *  https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296
 14 *  https://lwn.net/Articles/674854/
 15 *  https://github.com/google/syzkaller
 16 *  https://lwn.net/Articles/677764/
 17 *
 18 * Usage:
 19 * make run
 20 */
 21
 22#include "gcc-common.h"
 23
 24__visible int plugin_is_GPL_compatible;
 25
 26tree sancov_fndecl;
 27
 28static struct plugin_info sancov_plugin_info = {
 29	.version	= PLUGIN_VERSION,
 30	.help		= "sancov plugin\n",
 31};
 32
 33static unsigned int sancov_execute(void)
 34{
 35	basic_block bb;
 36
 37	/* Remove this line when this plugin and kcov will be in the kernel.
 38	if (!strcmp(DECL_NAME_POINTER(current_function_decl), DECL_NAME_POINTER(sancov_fndecl)))
 39		return 0;
 40	*/
 41
 42	FOR_EACH_BB_FN(bb, cfun) {
 43		const_gimple stmt;
 44		gcall *gcall;
 45		gimple_stmt_iterator gsi = gsi_after_labels(bb);
 46
 47		if (gsi_end_p(gsi))
 48			continue;
 49
 50		stmt = gsi_stmt(gsi);
 51		gcall = as_a_gcall(gimple_build_call(sancov_fndecl, 0));
 52		gimple_set_location(gcall, gimple_location(stmt));
 53		gsi_insert_before(&gsi, gcall, GSI_SAME_STMT);
 54	}
 55	return 0;
 56}
 57
 58#define PASS_NAME sancov
 59
 60#define NO_GATE
 61#define TODO_FLAGS_FINISH TODO_dump_func | TODO_verify_stmts | TODO_update_ssa_no_phi | TODO_verify_flow
 62
 63#include "gcc-generate-gimple-pass.h"
 64
 65static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data)
 66{
 67	tree leaf_attr, nothrow_attr;
 68	tree BT_FN_VOID = build_function_type_list(void_type_node, NULL_TREE);
 69
 70	sancov_fndecl = build_fn_decl("__sanitizer_cov_trace_pc", BT_FN_VOID);
 71
 72	DECL_ASSEMBLER_NAME(sancov_fndecl);
 73	TREE_PUBLIC(sancov_fndecl) = 1;
 74	DECL_EXTERNAL(sancov_fndecl) = 1;
 75	DECL_ARTIFICIAL(sancov_fndecl) = 1;
 76	DECL_PRESERVE_P(sancov_fndecl) = 1;
 77	DECL_UNINLINABLE(sancov_fndecl) = 1;
 78	TREE_USED(sancov_fndecl) = 1;
 79
 80	nothrow_attr = tree_cons(get_identifier("nothrow"), NULL, NULL);
 81	decl_attributes(&sancov_fndecl, nothrow_attr, 0);
 82	gcc_assert(TREE_NOTHROW(sancov_fndecl));
 
 83	leaf_attr = tree_cons(get_identifier("leaf"), NULL, NULL);
 84	decl_attributes(&sancov_fndecl, leaf_attr, 0);
 
 85}
 86
 87__visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
 88{
 89	int i;
 90	const char * const plugin_name = plugin_info->base_name;
 91	const int argc = plugin_info->argc;
 92	const struct plugin_argument * const argv = plugin_info->argv;
 93	bool enable = true;
 94
 95	static const struct ggc_root_tab gt_ggc_r_gt_sancov[] = {
 96		{
 97			.base = &sancov_fndecl,
 98			.nelt = 1,
 99			.stride = sizeof(sancov_fndecl),
100			.cb = &gt_ggc_mx_tree_node,
101			.pchw = &gt_pch_nx_tree_node
102		},
103		LAST_GGC_ROOT_TAB
104	};
105
106	/* BBs can be split afterwards?? */
 
107	PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE);
 
 
 
108
109	if (!plugin_default_version_check(version, &gcc_version)) {
110		error(G_("incompatible gcc/plugin versions"));
111		return 1;
112	}
113
114	for (i = 0; i < argc; ++i) {
115		if (!strcmp(argv[i].key, "no-sancov")) {
116			enable = false;
117			continue;
118		}
119		error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);
120	}
121
122	register_callback(plugin_name, PLUGIN_INFO, NULL, &sancov_plugin_info);
123
124	if (!enable)
125		return 0;
126
127#if BUILDING_GCC_VERSION < 6000
128	register_callback(plugin_name, PLUGIN_START_UNIT, &sancov_start_unit, NULL);
129	register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL, (void *)&gt_ggc_r_gt_sancov);
130	register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_pass_info);
131#endif
132
133	return 0;
134}