xref: /openbmc/linux/tools/objtool/objtool.c (revision 07d9a767)
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 
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.static_call_list);
65 	file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
66 	file.ignore_unreachables = no_unreachable;
67 	file.hints = false;
68 
69 	return &file;
70 }
71 
72 static void cmd_usage(void)
73 {
74 	unsigned int i, longest = 0;
75 
76 	printf("\n usage: %s\n\n", objtool_usage_string);
77 
78 	for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
79 		if (longest < strlen(objtool_cmds[i].name))
80 			longest = strlen(objtool_cmds[i].name);
81 	}
82 
83 	puts(" Commands:");
84 	for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
85 		printf("   %-*s   ", longest, objtool_cmds[i].name);
86 		puts(objtool_cmds[i].help);
87 	}
88 
89 	printf("\n");
90 
91 	if (!help)
92 		exit(129);
93 	exit(0);
94 }
95 
96 static void handle_options(int *argc, const char ***argv)
97 {
98 	while (*argc > 0) {
99 		const char *cmd = (*argv)[0];
100 
101 		if (cmd[0] != '-')
102 			break;
103 
104 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h")) {
105 			help = true;
106 			break;
107 		} else {
108 			fprintf(stderr, "Unknown option: %s\n", cmd);
109 			cmd_usage();
110 		}
111 
112 		(*argv)++;
113 		(*argc)--;
114 	}
115 }
116 
117 static void handle_internal_command(int argc, const char **argv)
118 {
119 	const char *cmd = argv[0];
120 	unsigned int i, ret;
121 
122 	for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
123 		struct cmd_struct *p = objtool_cmds+i;
124 
125 		if (strcmp(p->name, cmd))
126 			continue;
127 
128 		ret = p->fn(argc, argv);
129 
130 		exit(ret);
131 	}
132 
133 	cmd_usage();
134 }
135 
136 int main(int argc, const char **argv)
137 {
138 	static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
139 
140 	/* libsubcmd init */
141 	exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
142 	pager_init(UNUSED);
143 
144 	argv++;
145 	argc--;
146 	handle_options(&argc, &argv);
147 
148 	if (!argc || help)
149 		cmd_usage();
150 
151 	handle_internal_command(argc, argv);
152 
153 	return 0;
154 }
155