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543c37cb ER |
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 | ||
da7389ac | 24 | __visible int plugin_is_GPL_compatible; |
543c37cb ER |
25 | |
26 | tree sancov_fndecl; | |
27 | ||
28 | static struct plugin_info sancov_plugin_info = { | |
29 | .version = "20160402", | |
30 | .help = "sancov plugin\n", | |
31 | }; | |
32 | ||
33 | static 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 | ||
65 | static 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 | ||
da7389ac | 89 | __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version) |
543c37cb ER |
90 | { |
91 | int i; | |
92 | struct register_pass_info sancov_plugin_pass_info; | |
93 | const char * const plugin_name = plugin_info->base_name; | |
94 | const int argc = plugin_info->argc; | |
95 | const struct plugin_argument * const argv = plugin_info->argv; | |
96 | bool enable = true; | |
97 | ||
98 | static const struct ggc_root_tab gt_ggc_r_gt_sancov[] = { | |
99 | { | |
100 | .base = &sancov_fndecl, | |
101 | .nelt = 1, | |
102 | .stride = sizeof(sancov_fndecl), | |
103 | .cb = >_ggc_mx_tree_node, | |
104 | .pchw = >_pch_nx_tree_node | |
105 | }, | |
106 | LAST_GGC_ROOT_TAB | |
107 | }; | |
108 | ||
109 | /* BBs can be split afterwards?? */ | |
110 | sancov_plugin_pass_info.pass = make_sancov_pass(); | |
111 | #if BUILDING_GCC_VERSION >= 4009 | |
112 | sancov_plugin_pass_info.reference_pass_name = "asan"; | |
113 | #else | |
114 | sancov_plugin_pass_info.reference_pass_name = "nrv"; | |
115 | #endif | |
116 | sancov_plugin_pass_info.ref_pass_instance_number = 0; | |
117 | sancov_plugin_pass_info.pos_op = PASS_POS_INSERT_BEFORE; | |
118 | ||
119 | if (!plugin_default_version_check(version, &gcc_version)) { | |
120 | error(G_("incompatible gcc/plugin versions")); | |
121 | return 1; | |
122 | } | |
123 | ||
124 | for (i = 0; i < argc; ++i) { | |
125 | if (!strcmp(argv[i].key, "no-sancov")) { | |
126 | enable = false; | |
127 | continue; | |
128 | } | |
9165dabb | 129 | error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key); |
543c37cb ER |
130 | } |
131 | ||
132 | register_callback(plugin_name, PLUGIN_INFO, NULL, &sancov_plugin_info); | |
133 | ||
134 | if (!enable) | |
135 | return 0; | |
136 | ||
137 | #if BUILDING_GCC_VERSION < 6000 | |
138 | register_callback(plugin_name, PLUGIN_START_UNIT, &sancov_start_unit, NULL); | |
139 | register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL, (void *)>_ggc_r_gt_sancov); | |
140 | register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_plugin_pass_info); | |
141 | #endif | |
142 | ||
143 | return 0; | |
144 | } |