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 <stdlib.h>
19 #include <objtool/builtin.h>
20 #include <objtool/objtool.h>
21
22 bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
23 validate_dup, vmlinux, mcount, noinstr, backup;
24
25 static const char * const check_usage[] = {
26 "objtool check [<options>] file.o",
27 NULL,
28 };
29
30 static const char * const env_usage[] = {
31 "OBJTOOL_ARGS=\"<options>\"",
32 NULL,
33 };
34
35 const struct option check_options[] = {
36 OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"),
37 OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"),
38 OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"),
39 OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
40 OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
41 OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
42 OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
43 OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"),
44 OPT_BOOLEAN('n', "noinstr", &noinstr, "noinstr validation for vmlinux.o"),
45 OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
46 OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"),
47 OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"),
48 OPT_END(),
49 };
50
cmd_parse_options(int argc,const char ** argv,const char * const usage[])51 int cmd_parse_options(int argc, const char **argv, const char * const usage[])
52 {
53 const char *envv[16] = { };
54 char *env;
55 int envc;
56
57 env = getenv("OBJTOOL_ARGS");
58 if (env) {
59 envv[0] = "OBJTOOL_ARGS";
60 for (envc = 1; envc < ARRAY_SIZE(envv); ) {
61 envv[envc++] = env;
62 env = strchr(env, ' ');
63 if (!env)
64 break;
65 *env = '\0';
66 env++;
67 }
68
69 parse_options(envc, envv, check_options, env_usage, 0);
70 }
71
72 argc = parse_options(argc, argv, check_options, usage, 0);
73 if (argc != 1)
74 usage_with_options(usage, check_options);
75 return argc;
76 }
77
cmd_check(int argc,const char ** argv)78 int cmd_check(int argc, const char **argv)
79 {
80 const char *objname;
81 struct objtool_file *file;
82 int ret;
83
84 argc = cmd_parse_options(argc, argv, check_usage);
85 objname = argv[0];
86
87 file = objtool_open_read(objname);
88 if (!file)
89 return 1;
90
91 ret = check(file);
92 if (ret)
93 return ret;
94
95 if (file->elf->changed)
96 return elf_write(file->elf);
97
98 return 0;
99 }
100