1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
4 */
5
6 #include <stdio.h>
7 #include <stdbool.h>
8 #include <string.h>
9 #include <stdlib.h>
10 #include <unistd.h>
11 #include <subcmd/exec-cmd.h>
12 #include <subcmd/pager.h>
13 #include <linux/kernel.h>
14
15 #include <objtool/builtin.h>
16 #include <objtool/objtool.h>
17 #include <objtool/warn.h>
18
19 bool help;
20
21 const char *objname;
22 static struct objtool_file file;
23
24 static bool objtool_create_backup(const char *_objname)
25 {
26 int len = strlen(_objname);
27 char *buf, *base, *name = malloc(len+6);
28 int s, d, l, t;
29
30 if (!name) {
31 perror("failed backup name malloc");
32 return false;
33 }
34
35 strcpy(name, _objname);
36 strcpy(name + len, ".orig");
37
38 d = open(name, O_CREAT|O_WRONLY|O_TRUNC, 0644);
39 if (d < 0) {
40 perror("failed to create backup file");
41 return false;
42 }
43
44 s = open(_objname, O_RDONLY);
45 if (s < 0) {
46 perror("failed to open orig file");
47 return false;
48 }
49
50 buf = malloc(4096);
51 if (!buf) {
52 perror("failed backup data malloc");
53 return false;
54 }
55
56 while ((l = read(s, buf, 4096)) > 0) {
57 base = buf;
58 do {
59 t = write(d, base, l);
60 if (t < 0) {
61 perror("failed backup write");
62 return false;
63 }
64 base += t;
65 l -= t;
66 } while (l);
67 }
68
69 if (l < 0) {
70 perror("failed backup read");
71 return false;
72 }
73
74 free(name);
75 free(buf);
76 close(d);
77 close(s);
78
79 return true;
80 }
81
82 struct objtool_file *objtool_open_read(const char *_objname)
83 {
84 if (objname) {
85 if (strcmp(objname, _objname)) {
86 WARN("won't handle more than one file at a time");
87 return NULL;
88 }
89 return &file;
90 }
91 objname = _objname;
92
93 file.elf = elf_open_read(objname, O_RDWR);
94 if (!file.elf)
95 return NULL;
96
97 if (opts.backup && !objtool_create_backup(objname)) {
98 WARN("can't create backup file");
99 return NULL;
100 }
101
102 hash_init(file.insn_hash);
103 INIT_LIST_HEAD(&file.retpoline_call_list);
104 INIT_LIST_HEAD(&file.return_thunk_list);
105 INIT_LIST_HEAD(&file.static_call_list);
106 INIT_LIST_HEAD(&file.mcount_loc_list);
107 INIT_LIST_HEAD(&file.endbr_list);
108 INIT_LIST_HEAD(&file.call_list);
109 file.ignore_unreachables = opts.no_unreachable;
110 file.hints = false;
111
112 return &file;
113 }
114
115 void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func)
116 {
117 if (!opts.noinstr)
118 return;
119
120 if (!f->pv_ops) {
121 WARN("paravirt confusion");
122 return;
123 }
124
125 /*
126 * These functions will be patched into native code,
127 * see paravirt_patch().
128 */
129 if (!strcmp(func->name, "_paravirt_nop") ||
130 !strcmp(func->name, "_paravirt_ident_64"))
131 return;
132
133 /* already added this function */
134 if (!list_empty(&func->pv_target))
135 return;
136
137 list_add(&func->pv_target, &f->pv_ops[idx].targets);
138 f->pv_ops[idx].clean = false;
139 }
140
141 int main(int argc, const char **argv)
142 {
143 static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
144
145 /* libsubcmd init */
146 exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
147 pager_init(UNUSED);
148
149 return objtool_run(argc, argv);
150 }
151
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