1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
4 */
5
6 /*
7 * objtool:
8 *
9 * The 'check' subcmd analyzes every .o file and ensures the validity of its
10 * stack 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 <stdio.h>
17 #include <stdbool.h>
18 #include <string.h>
19 #include <stdlib.h>
20 #include <subcmd/exec-cmd.h>
21 #include <subcmd/pager.h>
22 #include <linux/kernel.h>
23
24 #include "builtin.h"
25 #include "objtool.h"
26 #include "warn.h"
27
28 struct cmd_struct {
29 const char *name;
30 int (*fn)(int, const char **);
31 const char *help;
32 };
33
34 static const char objtool_usage_string[] =
35 "objtool COMMAND [ARGS]";
36
37 static struct cmd_struct objtool_cmds[] = {
38 {"check", cmd_check, "Perform stack metadata validation on an object file" },
39 {"orc", cmd_orc, "Generate in-place ORC unwind tables for an object file" },
40 };
41
42 bool help;
43
44 const char *objname;
45 static struct objtool_file file;
46
objtool_open_read(const char * _objname)47 struct objtool_file *objtool_open_read(const char *_objname)
48 {
49 if (objname) {
50 if (strcmp(objname, _objname)) {
51 WARN("won't handle more than one file at a time");
52 return NULL;
53 }
54 return &file;
55 }
56 objname = _objname;
57
58 file.elf = elf_open_read(objname, O_RDWR);
59 if (!file.elf)
60 return NULL;
61
62 INIT_LIST_HEAD(&file.insn_list);
63 hash_init(file.insn_hash);
64 INIT_LIST_HEAD(&file.retpoline_call_list);
65 INIT_LIST_HEAD(&file.return_thunk_list);
66 INIT_LIST_HEAD(&file.static_call_list);
67 file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
68 file.ignore_unreachables = no_unreachable;
69 file.hints = false;
70
71 return &file;
72 }
73
cmd_usage(void)74 static void cmd_usage(void)
75 {
76 unsigned int i, longest = 0;
77
78 printf("\n usage: %s\n\n", objtool_usage_string);
79
80 for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
81 if (longest < strlen(objtool_cmds[i].name))
82 longest = strlen(objtool_cmds[i].name);
83 }
84
85 puts(" Commands:");
86 for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
87 printf(" %-*s ", longest, objtool_cmds[i].name);
88 puts(objtool_cmds[i].help);
89 }
90
91 printf("\n");
92
93 if (!help)
94 exit(129);
95 exit(0);
96 }
97
handle_options(int * argc,const char *** argv)98 static void handle_options(int *argc, const char ***argv)
99 {
100 while (*argc > 0) {
101 const char *cmd = (*argv)[0];
102
103 if (cmd[0] != '-')
104 break;
105
106 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h")) {
107 help = true;
108 break;
109 } else {
110 fprintf(stderr, "Unknown option: %s\n", cmd);
111 cmd_usage();
112 }
113
114 (*argv)++;
115 (*argc)--;
116 }
117 }
118
handle_internal_command(int argc,const char ** argv)119 static void handle_internal_command(int argc, const char **argv)
120 {
121 const char *cmd = argv[0];
122 unsigned int i, ret;
123
124 for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
125 struct cmd_struct *p = objtool_cmds+i;
126
127 if (strcmp(p->name, cmd))
128 continue;
129
130 ret = p->fn(argc, argv);
131
132 exit(ret);
133 }
134
135 cmd_usage();
136 }
137
main(int argc,const char ** argv)138 int main(int argc, const char **argv)
139 {
140 static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
141
142 /* libsubcmd init */
143 exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
144 pager_init(UNUSED);
145
146 argv++;
147 argc--;
148 handle_options(&argc, &argv);
149
150 if (!argc || help)
151 cmd_usage();
152
153 handle_internal_command(argc, argv);
154
155 return 0;
156 }
157