xref: /linux/tools/objtool/objtool.c (revision be709d48329a500621d2a05835283150ae137b45)
1 /*
2  * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 /*
19  * objtool:
20  *
21  * The 'check' subcmd analyzes every .o file and ensures the validity of its
22  * stack trace metadata.  It enforces a set of rules on asm code and C inline
23  * assembly code so that stack traces can be reliable.
24  *
25  * For more information, see tools/objtool/Documentation/stack-validation.txt.
26  */
27 
28 #include <stdio.h>
29 #include <stdbool.h>
30 #include <string.h>
31 #include <stdlib.h>
32 #include <subcmd/exec-cmd.h>
33 #include <subcmd/pager.h>
34 #include <linux/kernel.h>
35 
36 #include "builtin.h"
37 
38 struct cmd_struct {
39 	const char *name;
40 	int (*fn)(int, const char **);
41 	const char *help;
42 };
43 
44 static const char objtool_usage_string[] =
45 	"objtool COMMAND [ARGS]";
46 
47 static struct cmd_struct objtool_cmds[] = {
48 	{"check",	cmd_check,	"Perform stack metadata validation on an object file" },
49 	{"orc",		cmd_orc,	"Generate in-place ORC unwind tables for an object file" },
50 };
51 
52 bool help;
53 
54 static void cmd_usage(void)
55 {
56 	unsigned int i, longest = 0;
57 
58 	printf("\n usage: %s\n\n", objtool_usage_string);
59 
60 	for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
61 		if (longest < strlen(objtool_cmds[i].name))
62 			longest = strlen(objtool_cmds[i].name);
63 	}
64 
65 	puts(" Commands:");
66 	for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
67 		printf("   %-*s   ", longest, objtool_cmds[i].name);
68 		puts(objtool_cmds[i].help);
69 	}
70 
71 	printf("\n");
72 
73 	exit(129);
74 }
75 
76 static void handle_options(int *argc, const char ***argv)
77 {
78 	while (*argc > 0) {
79 		const char *cmd = (*argv)[0];
80 
81 		if (cmd[0] != '-')
82 			break;
83 
84 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h")) {
85 			help = true;
86 			break;
87 		} else {
88 			fprintf(stderr, "Unknown option: %s\n", cmd);
89 			cmd_usage();
90 		}
91 
92 		(*argv)++;
93 		(*argc)--;
94 	}
95 }
96 
97 static void handle_internal_command(int argc, const char **argv)
98 {
99 	const char *cmd = argv[0];
100 	unsigned int i, ret;
101 
102 	for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
103 		struct cmd_struct *p = objtool_cmds+i;
104 
105 		if (strcmp(p->name, cmd))
106 			continue;
107 
108 		ret = p->fn(argc, argv);
109 
110 		exit(ret);
111 	}
112 
113 	cmd_usage();
114 }
115 
116 int main(int argc, const char **argv)
117 {
118 	static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
119 
120 	/* libsubcmd init */
121 	exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
122 	pager_init(UNUSED);
123 
124 	argv++;
125 	argc--;
126 	handle_options(&argc, &argv);
127 
128 	if (!argc || help)
129 		cmd_usage();
130 
131 	handle_internal_command(argc, argv);
132 
133 	return 0;
134 }
135