1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>
4 */
5
6/*
7 * objtool check:
8 *
9 * This command analyzes every .o file and ensures the validity of its stack
10 * trace metadata.  It enforces a set of rules on asm code and C inline
11 * assembly code so that stack traces can be reliable.
12 *
13 * For more information, see tools/objtool/Documentation/stack-validation.txt.
14 */
15
16#include <subcmd/parse-options.h>
17#include <string.h>
18#include "builtin.h"
19#include "objtool.h"
20
21bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
22     validate_dup, vmlinux, sls, unret, rethunk;
23
24static const char * const check_usage[] = {
25	"objtool check [<options>] file.o",
26	NULL,
27};
28
29const struct option check_options[] = {
30	OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"),
31	OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"),
32	OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"),
33	OPT_BOOLEAN(0,   "rethunk", &rethunk, "validate and annotate rethunk usage"),
34	OPT_BOOLEAN(0,   "unret", &unret, "validate entry unret placement"),
35	OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
36	OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
37	OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
38	OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
39	OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"),
40	OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
41	OPT_BOOLEAN('S', "sls", &sls, "validate straight-line-speculation"),
42	OPT_END(),
43};
44
45int cmd_check(int argc, const char **argv)
46{
47	const char *objname, *s;
48	struct objtool_file *file;
49	int ret;
50
51	argc = parse_options(argc, argv, check_options, check_usage, 0);
52
53	if (argc != 1)
54		usage_with_options(check_usage, check_options);
55
56	objname = argv[0];
57
58	s = strstr(objname, "vmlinux.o");
59	if (s && !s[9])
60		vmlinux = true;
61
62	file = objtool_open_read(objname);
63	if (!file)
64		return 1;
65
66	ret = check(file);
67	if (ret)
68		return ret;
69
70	if (file->elf->changed)
71		return elf_write(file->elf);
72
73	return 0;
74}
75