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	 af2d22254e
			
		
	
	
		af2d22254e
		
	
	
	
	
		
			
			Documentation/process/changes.rst says the minimal GCC version is 4.9. Hence, BUILDING_GCC_VERSION is greater than or equal to 4009. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201202134929.99883-1-masahiroy@kernel.org
		
			
				
	
	
		
			134 lines
		
	
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			134 lines
		
	
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright 2011-2016 by Emese Revfy <re.emese@gmail.com>
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|  * Licensed under the GPL v2, or (at your option) v3
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|  *
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|  * Homepage:
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|  * https://github.com/ephox-gcc-plugins/sancov
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|  *
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|  * This plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks.
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|  * It supports all gcc versions with plugin support (from gcc-4.5 on).
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|  * It is based on the commit "Add fuzzing coverage support" by Dmitry Vyukov <dvyukov@google.com>.
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|  *
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|  * You can read about it more here:
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|  *  https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296
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|  *  https://lwn.net/Articles/674854/
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|  *  https://github.com/google/syzkaller
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|  *  https://lwn.net/Articles/677764/
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|  *
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|  * Usage:
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|  * make run
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|  */
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| 
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| #include "gcc-common.h"
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| 
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| __visible int plugin_is_GPL_compatible;
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| 
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| tree sancov_fndecl;
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| 
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| static struct plugin_info sancov_plugin_info = {
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| 	.version	= "20160402",
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| 	.help		= "sancov plugin\n",
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| };
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| 
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| static unsigned int sancov_execute(void)
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| {
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| 	basic_block bb;
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| 
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| 	/* Remove this line when this plugin and kcov will be in the kernel.
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| 	if (!strcmp(DECL_NAME_POINTER(current_function_decl), DECL_NAME_POINTER(sancov_fndecl)))
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| 		return 0;
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| 	*/
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| 
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| 	FOR_EACH_BB_FN(bb, cfun) {
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| 		const_gimple stmt;
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| 		gcall *gcall;
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| 		gimple_stmt_iterator gsi = gsi_after_labels(bb);
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| 
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| 		if (gsi_end_p(gsi))
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| 			continue;
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| 
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| 		stmt = gsi_stmt(gsi);
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| 		gcall = as_a_gcall(gimple_build_call(sancov_fndecl, 0));
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| 		gimple_set_location(gcall, gimple_location(stmt));
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| 		gsi_insert_before(&gsi, gcall, GSI_SAME_STMT);
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| 	}
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| 	return 0;
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| }
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| 
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| #define PASS_NAME sancov
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| 
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| #define NO_GATE
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| #define TODO_FLAGS_FINISH TODO_dump_func | TODO_verify_stmts | TODO_update_ssa_no_phi | TODO_verify_flow
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| 
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| #include "gcc-generate-gimple-pass.h"
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| 
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| static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data)
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| {
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| 	tree leaf_attr, nothrow_attr;
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| 	tree BT_FN_VOID = build_function_type_list(void_type_node, NULL_TREE);
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| 
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| 	sancov_fndecl = build_fn_decl("__sanitizer_cov_trace_pc", BT_FN_VOID);
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| 
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| 	DECL_ASSEMBLER_NAME(sancov_fndecl);
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| 	TREE_PUBLIC(sancov_fndecl) = 1;
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| 	DECL_EXTERNAL(sancov_fndecl) = 1;
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| 	DECL_ARTIFICIAL(sancov_fndecl) = 1;
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| 	DECL_PRESERVE_P(sancov_fndecl) = 1;
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| 	DECL_UNINLINABLE(sancov_fndecl) = 1;
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| 	TREE_USED(sancov_fndecl) = 1;
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| 
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| 	nothrow_attr = tree_cons(get_identifier("nothrow"), NULL, NULL);
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| 	decl_attributes(&sancov_fndecl, nothrow_attr, 0);
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| 	gcc_assert(TREE_NOTHROW(sancov_fndecl));
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| 	leaf_attr = tree_cons(get_identifier("leaf"), NULL, NULL);
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| 	decl_attributes(&sancov_fndecl, leaf_attr, 0);
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| }
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| 
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| __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
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| {
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| 	int i;
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| 	const char * const plugin_name = plugin_info->base_name;
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| 	const int argc = plugin_info->argc;
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| 	const struct plugin_argument * const argv = plugin_info->argv;
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| 	bool enable = true;
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| 
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| 	static const struct ggc_root_tab gt_ggc_r_gt_sancov[] = {
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| 		{
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| 			.base = &sancov_fndecl,
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| 			.nelt = 1,
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| 			.stride = sizeof(sancov_fndecl),
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| 			.cb = >_ggc_mx_tree_node,
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| 			.pchw = >_pch_nx_tree_node
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| 		},
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| 		LAST_GGC_ROOT_TAB
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| 	};
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| 
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| 	/* BBs can be split afterwards?? */
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| 	PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE);
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| 
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| 	if (!plugin_default_version_check(version, &gcc_version)) {
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| 		error(G_("incompatible gcc/plugin versions"));
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| 		return 1;
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| 	}
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| 
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| 	for (i = 0; i < argc; ++i) {
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| 		if (!strcmp(argv[i].key, "no-sancov")) {
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| 			enable = false;
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| 			continue;
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| 		}
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| 		error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);
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| 	}
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| 
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| 	register_callback(plugin_name, PLUGIN_INFO, NULL, &sancov_plugin_info);
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| 
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| 	if (!enable)
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| 		return 0;
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| 
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| #if BUILDING_GCC_VERSION < 6000
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| 	register_callback(plugin_name, PLUGIN_START_UNIT, &sancov_start_unit, NULL);
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| 	register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL, (void *)>_ggc_r_gt_sancov);
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| 	register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_pass_info);
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| #endif
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| 
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| 	return 0;
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| }
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