tjh.dev
Linux kernel mirror (for testing)
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linux
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
17struct opts opts;
18
19static const char * const check_usage[] = {
20 "objtool <actions> [<options>] file.o",
21 NULL,
22};
23
24static const char * const env_usage[] = {
25 "OBJTOOL_ARGS=\"<options>\"",
26 NULL,
27};
28
29static 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
39static 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 return found ? 0 : -1;
61}
62
63const struct option check_options[] = {
64 OPT_GROUP("Actions:"),
65 OPT_CALLBACK_OPTARG('h', "hacks", NULL, NULL, "jump_label,noinstr", "patch toolchain bugs/limitations", parse_hacks),
66 OPT_BOOLEAN('i', "ibt", &opts.ibt, "validate and annotate IBT"),
67 OPT_BOOLEAN('m', "mcount", &opts.mcount, "annotate mcount/fentry calls for ftrace"),
68 OPT_BOOLEAN('n', "noinstr", &opts.noinstr, "validate noinstr rules"),
69 OPT_BOOLEAN('o', "orc", &opts.orc, "generate ORC metadata"),
70 OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"),
71 OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"),
72 OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"),
73 OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"),
74 OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"),
75 OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump),
76
77 OPT_GROUP("Options:"),
78 OPT_BOOLEAN(0, "backtrace", &opts.backtrace, "unwind on error"),
79 OPT_BOOLEAN(0, "backup", &opts.backup, "create .orig files before modification"),
80 OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
81 OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"),
82 OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"),
83 OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"),
84 OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
85 OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),
86
87 OPT_END(),
88};
89
90int cmd_parse_options(int argc, const char **argv, const char * const usage[])
91{
92 const char *envv[16] = { };
93 char *env;
94 int envc;
95
96 env = getenv("OBJTOOL_ARGS");
97 if (env) {
98 envv[0] = "OBJTOOL_ARGS";
99 for (envc = 1; envc < ARRAY_SIZE(envv); ) {
100 envv[envc++] = env;
101 env = strchr(env, ' ');
102 if (!env)
103 break;
104 *env = '\0';
105 env++;
106 }
107
108 parse_options(envc, envv, check_options, env_usage, 0);
109 }
110
111 argc = parse_options(argc, argv, check_options, usage, 0);
112 if (argc != 1)
113 usage_with_options(usage, check_options);
114 return argc;
115}
116
117static bool opts_valid(void)
118{
119 if (opts.hack_jump_label ||
120 opts.hack_noinstr ||
121 opts.ibt ||
122 opts.mcount ||
123 opts.noinstr ||
124 opts.orc ||
125 opts.retpoline ||
126 opts.sls ||
127 opts.stackval ||
128 opts.static_call ||
129 opts.uaccess) {
130 if (opts.dump_orc) {
131 ERROR("--dump can't be combined with other options");
132 return false;
133 }
134
135 return true;
136 }
137
138 if (opts.dump_orc)
139 return true;
140
141 ERROR("At least one command required");
142 return false;
143}
144
145static bool link_opts_valid(struct objtool_file *file)
146{
147 if (opts.link)
148 return true;
149
150 if (has_multiple_files(file->elf)) {
151 ERROR("Linked object detected, forcing --link");
152 opts.link = true;
153 return true;
154 }
155
156 if (opts.noinstr) {
157 ERROR("--noinstr requires --link");
158 return false;
159 }
160
161 if (opts.ibt) {
162 ERROR("--ibt requires --link");
163 return false;
164 }
165
166 return true;
167}
168
169int objtool_run(int argc, const char **argv)
170{
171 const char *objname;
172 struct objtool_file *file;
173 int ret;
174
175 argc = cmd_parse_options(argc, argv, check_usage);
176 objname = argv[0];
177
178 if (!opts_valid())
179 return 1;
180
181 if (opts.dump_orc)
182 return orc_dump(objname);
183
184 file = objtool_open_read(objname);
185 if (!file)
186 return 1;
187
188 if (!link_opts_valid(file))
189 return 1;
190
191 ret = check(file);
192 if (ret)
193 return ret;
194
195 if (file->elf->changed)
196 return elf_write(file->elf);
197
198 return 0;
199}