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, sls, unret, rethunk;
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(0, "rethunk", &rethunk, "validate and annotate rethunk usage"),
40 OPT_BOOLEAN(0, "unret", &unret, "validate entry unret placement"),
41 OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
42 OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
43 OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
44 OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
45 OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"),
46 OPT_BOOLEAN('n', "noinstr", &noinstr, "noinstr validation for vmlinux.o"),
47 OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
48 OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"),
49 OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"),
50 OPT_BOOLEAN('S', "sls", &sls, "validate straight-line-speculation"),
51 OPT_END(),
52 };
53
cmd_parse_options(int argc,const char ** argv,const char * const usage[])54 int cmd_parse_options(int argc, const char **argv, const char * const usage[])
55 {
56 const char *envv[16] = { };
57 char *env;
58 int envc;
59
60 env = getenv("OBJTOOL_ARGS");
61 if (env) {
62 envv[0] = "OBJTOOL_ARGS";
63 for (envc = 1; envc < ARRAY_SIZE(envv); ) {
64 envv[envc++] = env;
65 env = strchr(env, ' ');
66 if (!env)
67 break;
68 *env = '\0';
69 env++;
70 }
71
72 parse_options(envc, envv, check_options, env_usage, 0);
73 }
74
75 argc = parse_options(argc, argv, check_options, usage, 0);
76 if (argc != 1)
77 usage_with_options(usage, check_options);
78 return argc;
79 }
80
cmd_check(int argc,const char ** argv)81 int cmd_check(int argc, const char **argv)
82 {
83 const char *objname;
84 struct objtool_file *file;
85 int ret;
86
87 argc = cmd_parse_options(argc, argv, check_usage);
88 objname = argv[0];
89
90 file = objtool_open_read(objname);
91 if (!file)
92 return 1;
93
94 ret = check(file);
95 if (ret)
96 return ret;
97
98 if (file->elf->changed)
99 return elf_write(file->elf);
100
101 return 0;
102 }
103