summaryrefslogtreecommitdiff
path: root/tools/objtool/builtin-check.c
blob: 24fbe803a0d3206246863bdb59f10bd38704b145 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>
 */

#include <subcmd/parse-options.h>
#include <string.h>
#include <stdlib.h>
#include <objtool/builtin.h>
#include <objtool/objtool.h>

#define ERROR(format, ...)				\
	fprintf(stderr,					\
		"error: objtool: " format "\n",		\
		##__VA_ARGS__)

struct opts opts;

static const char * const check_usage[] = {
	"objtool <actions> [<options>] file.o",
	NULL,
};

static const char * const env_usage[] = {
	"OBJTOOL_ARGS=\"<options>\"",
	NULL,
};

static int parse_dump(const struct option *opt, const char *str, int unset)
{
	if (!str || !strcmp(str, "orc")) {
		opts.dump_orc = true;
		return 0;
	}

	return -1;
}

static int parse_hacks(const struct option *opt, const char *str, int unset)
{
	bool found = false;

	/*
	 * Use strstr() as a lazy method of checking for comma-separated
	 * options.
	 *
	 * No string provided == enable all options.
	 */

	if (!str || strstr(str, "jump_label")) {
		opts.hack_jump_label = true;
		found = true;
	}

	if (!str || strstr(str, "noinstr")) {
		opts.hack_noinstr = true;
		found = true;
	}

	return found ? 0 : -1;
}

const struct option check_options[] = {
	OPT_GROUP("Actions:"),
	OPT_CALLBACK_OPTARG('h', "hacks", NULL, NULL, "jump_label,noinstr", "patch toolchain bugs/limitations", parse_hacks),
	OPT_BOOLEAN('i', "ibt", &opts.ibt, "validate and annotate IBT"),
	OPT_BOOLEAN('m', "mcount", &opts.mcount, "annotate mcount/fentry calls for ftrace"),
	OPT_BOOLEAN('n', "noinstr", &opts.noinstr, "validate noinstr rules"),
	OPT_BOOLEAN('o', "orc", &opts.orc, "generate ORC metadata"),
	OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"),
	OPT_BOOLEAN(0,   "rethunk", &opts.rethunk, "validate and annotate rethunk usage"),
	OPT_BOOLEAN(0,   "unret", &opts.unret, "validate entry unret placement"),
	OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"),
	OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"),
	OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"),
	OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"),
	OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump),

	OPT_GROUP("Options:"),
	OPT_BOOLEAN(0, "backtrace", &opts.backtrace, "unwind on error"),
	OPT_BOOLEAN(0, "backup", &opts.backup, "create .orig files before modification"),
	OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
	OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"),
	OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"),
	OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"),
	OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
	OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),

	OPT_END(),
};

int cmd_parse_options(int argc, const char **argv, const char * const usage[])
{
	const char *envv[16] = { };
	char *env;
	int envc;

	env = getenv("OBJTOOL_ARGS");
	if (env) {
		envv[0] = "OBJTOOL_ARGS";
		for (envc = 1; envc < ARRAY_SIZE(envv); ) {
			envv[envc++] = env;
			env = strchr(env, ' ');
			if (!env)
				break;
			*env = '\0';
			env++;
		}

		parse_options(envc, envv, check_options, env_usage, 0);
	}

	argc = parse_options(argc, argv, check_options, usage, 0);
	if (argc != 1)
		usage_with_options(usage, check_options);
	return argc;
}

static bool opts_valid(void)
{
	if (opts.hack_jump_label	||
	    opts.hack_noinstr		||
	    opts.ibt			||
	    opts.mcount			||
	    opts.noinstr		||
	    opts.orc			||
	    opts.retpoline		||
	    opts.rethunk		||
	    opts.sls			||
	    opts.stackval		||
	    opts.static_call		||
	    opts.uaccess) {
		if (opts.dump_orc) {
			ERROR("--dump can't be combined with other options");
			return false;
		}

		return true;
	}

	if (opts.unret && !opts.rethunk) {
		ERROR("--unret requires --rethunk");
		return false;
	}

	if (opts.dump_orc)
		return true;

	ERROR("At least one command required");
	return false;
}

static bool link_opts_valid(struct objtool_file *file)
{
	if (opts.link)
		return true;

	if (has_multiple_files(file->elf)) {
		ERROR("Linked object detected, forcing --link");
		opts.link = true;
		return true;
	}

	if (opts.noinstr) {
		ERROR("--noinstr requires --link");
		return false;
	}

	if (opts.ibt) {
		ERROR("--ibt requires --link");
		return false;
	}

	if (opts.unret) {
		ERROR("--unret requires --link");
		return false;
	}

	return true;
}

int objtool_run(int argc, const char **argv)
{
	const char *objname;
	struct objtool_file *file;
	int ret;

	argc = cmd_parse_options(argc, argv, check_usage);
	objname = argv[0];

	if (!opts_valid())
		return 1;

	if (opts.dump_orc)
		return orc_dump(objname);

	file = objtool_open_read(objname);
	if (!file)
		return 1;

	if (!link_opts_valid(file))
		return 1;

	ret = check(file);
	if (ret)
		return ret;

	if (file->elf->changed)
		return elf_write(file->elf);

	return 0;
}