xref: /openbmc/linux/tools/objtool/objtool.c (revision 4f6cce39)
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 
35 #include "builtin.h"
36 
37 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
38 
39 struct cmd_struct {
40 	const char *name;
41 	int (*fn)(int, const char **);
42 	const char *help;
43 };
44 
45 static const char objtool_usage_string[] =
46 	"objtool [OPTIONS] COMMAND [ARGS]";
47 
48 static struct cmd_struct objtool_cmds[] = {
49 	{"check",	cmd_check,	"Perform stack metadata validation on 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(1);
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 			fprintf(stderr, "\n Usage: %s\n",
90 				objtool_usage_string);
91 			exit(1);
92 		}
93 
94 		(*argv)++;
95 		(*argc)--;
96 	}
97 }
98 
99 static void handle_internal_command(int argc, const char **argv)
100 {
101 	const char *cmd = argv[0];
102 	unsigned int i, ret;
103 
104 	for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
105 		struct cmd_struct *p = objtool_cmds+i;
106 
107 		if (strcmp(p->name, cmd))
108 			continue;
109 
110 		ret = p->fn(argc, argv);
111 
112 		exit(ret);
113 	}
114 
115 	cmd_usage();
116 }
117 
118 int main(int argc, const char **argv)
119 {
120 	static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
121 
122 	/* libsubcmd init */
123 	exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
124 	pager_init(UNUSED);
125 
126 	argv++;
127 	argc--;
128 	handle_options(&argc, &argv);
129 
130 	if (!argc || help)
131 		cmd_usage();
132 
133 	handle_internal_command(argc, argv);
134 
135 	return 0;
136 }
137