1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>
4 */
5
6 #include <subcmd/parse-options.h>
7 #include <string.h>
8 #include <stdlib.h>
9 #include <objtool/builtin.h>
10 #include <objtool/objtool.h>
11
12 #define ERROR(format, ...) \
13 fprintf(stderr, \
14 "error: objtool: " format "\n", \
15 ##__VA_ARGS__)
16
17 struct opts opts;
18
19 static const char * const check_usage[] = {
20 "objtool <actions> [<options>] file.o",
21 NULL,
22 };
23
24 static const char * const env_usage[] = {
25 "OBJTOOL_ARGS=\"<options>\"",
26 NULL,
27 };
28
parse_dump(const struct option * opt,const char * str,int unset)29 static int parse_dump(const struct option *opt, const char *str, int unset)
30 {
31 if (!str || !strcmp(str, "orc")) {
32 opts.dump_orc = true;
33 return 0;
34 }
35
36 return -1;
37 }
38
parse_hacks(const struct option * opt,const char * str,int unset)39 static int parse_hacks(const struct option *opt, const char *str, int unset)
40 {
41 bool found = false;
42
43 /*
44 * Use strstr() as a lazy method of checking for comma-separated
45 * options.
46 *
47 * No string provided == enable all options.
48 */
49
50 if (!str || strstr(str, "jump_label")) {
51 opts.hack_jump_label = true;
52 found = true;
53 }
54
55 if (!str || strstr(str, "noinstr")) {
56 opts.hack_noinstr = true;
57 found = true;
58 }
59
60 if (!str || strstr(str, "skylake")) {
61 opts.hack_skylake = true;
62 found = true;
63 }
64
65 return found ? 0 : -1;
66 }
67
68 static const struct option check_options[] = {
69 OPT_GROUP("Actions:"),
70 OPT_CALLBACK_OPTARG('h', "hacks", NULL, NULL, "jump_label,noinstr,skylake", "patch toolchain bugs/limitations", parse_hacks),
71 OPT_BOOLEAN('i', "ibt", &opts.ibt, "validate and annotate IBT"),
72 OPT_BOOLEAN('m', "mcount", &opts.mcount, "annotate mcount/fentry calls for ftrace"),
73 OPT_BOOLEAN('n', "noinstr", &opts.noinstr, "validate noinstr rules"),
74 OPT_BOOLEAN('o', "orc", &opts.orc, "generate ORC metadata"),
75 OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"),
76 OPT_BOOLEAN(0, "rethunk", &opts.rethunk, "validate and annotate rethunk usage"),
77 OPT_BOOLEAN(0, "unret", &opts.unret, "validate entry unret placement"),
78 OPT_INTEGER(0, "prefix", &opts.prefix, "generate prefix symbols"),
79 OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"),
80 OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"),
81 OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"),
82 OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"),
83 OPT_BOOLEAN(0 , "cfi", &opts.cfi, "annotate kernel control flow integrity (kCFI) function preambles"),
84 OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump),
85
86 OPT_GROUP("Options:"),
87 OPT_BOOLEAN(0, "backtrace", &opts.backtrace, "unwind on error"),
88 OPT_BOOLEAN(0, "backup", &opts.backup, "create .orig files before modification"),
89 OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
90 OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"),
91 OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"),
92 OPT_BOOLEAN(0, "mnop", &opts.mnop, "nop out mcount call sites"),
93 OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"),
94 OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
95 OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),
96
97 OPT_END(),
98 };
99
cmd_parse_options(int argc,const char ** argv,const char * const usage[])100 int cmd_parse_options(int argc, const char **argv, const char * const usage[])
101 {
102 const char *envv[16] = { };
103 char *env;
104 int envc;
105
106 env = getenv("OBJTOOL_ARGS");
107 if (env) {
108 envv[0] = "OBJTOOL_ARGS";
109 for (envc = 1; envc < ARRAY_SIZE(envv); ) {
110 envv[envc++] = env;
111 env = strchr(env, ' ');
112 if (!env)
113 break;
114 *env = '\0';
115 env++;
116 }
117
118 parse_options(envc, envv, check_options, env_usage, 0);
119 }
120
121 argc = parse_options(argc, argv, check_options, usage, 0);
122 if (argc != 1)
123 usage_with_options(usage, check_options);
124 return argc;
125 }
126
opts_valid(void)127 static bool opts_valid(void)
128 {
129 if (opts.hack_jump_label ||
130 opts.hack_noinstr ||
131 opts.ibt ||
132 opts.mcount ||
133 opts.noinstr ||
134 opts.orc ||
135 opts.retpoline ||
136 opts.rethunk ||
137 opts.sls ||
138 opts.stackval ||
139 opts.static_call ||
140 opts.uaccess) {
141 if (opts.dump_orc) {
142 ERROR("--dump can't be combined with other options");
143 return false;
144 }
145
146 return true;
147 }
148
149 if (opts.unret && !opts.rethunk) {
150 ERROR("--unret requires --rethunk");
151 return false;
152 }
153
154 if (opts.dump_orc)
155 return true;
156
157 ERROR("At least one command required");
158 return false;
159 }
160
mnop_opts_valid(void)161 static bool mnop_opts_valid(void)
162 {
163 if (opts.mnop && !opts.mcount) {
164 ERROR("--mnop requires --mcount");
165 return false;
166 }
167
168 return true;
169 }
170
link_opts_valid(struct objtool_file * file)171 static bool link_opts_valid(struct objtool_file *file)
172 {
173 if (opts.link)
174 return true;
175
176 if (has_multiple_files(file->elf)) {
177 ERROR("Linked object detected, forcing --link");
178 opts.link = true;
179 return true;
180 }
181
182 if (opts.noinstr) {
183 ERROR("--noinstr requires --link");
184 return false;
185 }
186
187 if (opts.ibt) {
188 ERROR("--ibt requires --link");
189 return false;
190 }
191
192 if (opts.unret) {
193 ERROR("--unret requires --link");
194 return false;
195 }
196
197 return true;
198 }
199
objtool_run(int argc,const char ** argv)200 int objtool_run(int argc, const char **argv)
201 {
202 const char *objname;
203 struct objtool_file *file;
204 int ret;
205
206 argc = cmd_parse_options(argc, argv, check_usage);
207 objname = argv[0];
208
209 if (!opts_valid())
210 return 1;
211
212 if (opts.dump_orc)
213 return orc_dump(objname);
214
215 file = objtool_open_read(objname);
216 if (!file)
217 return 1;
218
219 if (!mnop_opts_valid())
220 return 1;
221
222 if (!link_opts_valid(file))
223 return 1;
224
225 ret = check(file);
226 if (ret)
227 return ret;
228
229 if (file->elf->changed)
230 return elf_write(file->elf);
231
232 return 0;
233 }
234