1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright (C) IBM Corporation, 2009
5 */
6
7#include <stdlib.h>
8#include <stdio.h>
9#include <string.h>
10#include <assert.h>
11#include <unistd.h>
12#include <stdarg.h>
13#include <linux/kallsyms.h>
14
15#include <asm/insn.h>
16#include <inat.c>
17#include <insn.c>
18
19/*
20 * Test of instruction analysis in general and insn_get_length() in
21 * particular. See if insn_get_length() and the disassembler agree
22 * on the length of each instruction in an elf disassembly.
23 *
24 * Usage: objdump -d a.out | awk -f objdump_reformat.awk | ./insn_decoder_test
25 */
26
27const char *prog;
28static int verbose;
29static int x86_64;
30
31static void usage(void)
32{
33 fprintf(stderr, format: "Usage: objdump -d a.out | awk -f objdump_reformat.awk"
34 " | %s [-y|-n] [-v]\n", prog);
35 fprintf(stderr, format: "\t-y 64bit mode\n");
36 fprintf(stderr, format: "\t-n 32bit mode\n");
37 fprintf(stderr, format: "\t-v verbose mode\n");
38 exit(status: 1);
39}
40
41static void malformed_line(const char *line, int line_nr)
42{
43 fprintf(stderr, format: "%s: error: malformed line %d:\n%s",
44 prog, line_nr, line);
45 exit(status: 3);
46}
47
48static void pr_warn(const char *fmt, ...)
49{
50 va_list ap;
51
52 fprintf(stderr, format: "%s: warning: ", prog);
53 va_start(ap, fmt);
54 vfprintf(stderr, format: fmt, arg: ap);
55 va_end(ap);
56}
57
58static void dump_field(FILE *fp, const char *name, const char *indent,
59 struct insn_field *field)
60{
61 fprintf(stream: fp, format: "%s.%s = {\n", indent, name);
62 fprintf(stream: fp, format: "%s\t.value = %d, bytes[] = {%x, %x, %x, %x},\n",
63 indent, field->value, field->bytes[0], field->bytes[1],
64 field->bytes[2], field->bytes[3]);
65 fprintf(stream: fp, format: "%s\t.got = %d, .nbytes = %d},\n", indent,
66 field->got, field->nbytes);
67}
68
69static void dump_insn(FILE *fp, struct insn *insn)
70{
71 fprintf(stream: fp, format: "Instruction = {\n");
72 dump_field(fp, name: "prefixes", indent: "\t", field: &insn->prefixes);
73 dump_field(fp, name: "rex_prefix", indent: "\t", field: &insn->rex_prefix);
74 dump_field(fp, name: "vex_prefix", indent: "\t", field: &insn->vex_prefix);
75 dump_field(fp, name: "opcode", indent: "\t", field: &insn->opcode);
76 dump_field(fp, name: "modrm", indent: "\t", field: &insn->modrm);
77 dump_field(fp, name: "sib", indent: "\t", field: &insn->sib);
78 dump_field(fp, name: "displacement", indent: "\t", field: &insn->displacement);
79 dump_field(fp, name: "immediate1", indent: "\t", field: &insn->immediate1);
80 dump_field(fp, name: "immediate2", indent: "\t", field: &insn->immediate2);
81 fprintf(stream: fp, format: "\t.attr = %x, .opnd_bytes = %d, .addr_bytes = %d,\n",
82 insn->attr, insn->opnd_bytes, insn->addr_bytes);
83 fprintf(stream: fp, format: "\t.length = %d, .x86_64 = %d, .kaddr = %p}\n",
84 insn->length, insn->x86_64, insn->kaddr);
85}
86
87static void parse_args(int argc, char **argv)
88{
89 int c;
90 prog = argv[0];
91 while ((c = getopt(argc: argc, argv: argv, shortopts: "ynv")) != -1) {
92 switch (c) {
93 case 'y':
94 x86_64 = 1;
95 break;
96 case 'n':
97 x86_64 = 0;
98 break;
99 case 'v':
100 verbose = 1;
101 break;
102 default:
103 usage();
104 }
105 }
106}
107
108#define BUFSIZE (256 + KSYM_NAME_LEN)
109
110int main(int argc, char **argv)
111{
112 char line[BUFSIZE], sym[BUFSIZE] = "<unknown>";
113 unsigned char insn_buff[16];
114 struct insn insn;
115 int insns = 0;
116 int warnings = 0;
117
118 parse_args(argc, argv);
119
120 while (fgets(s: line, BUFSIZE, stdin)) {
121 char copy[BUFSIZE], *s, *tab1, *tab2;
122 int nb = 0, ret;
123 unsigned int b;
124
125 if (line[0] == '<') {
126 /* Symbol line */
127 strcpy(dest: sym, src: line);
128 continue;
129 }
130
131 insns++;
132 memset(s: insn_buff, c: 0, n: 16);
133 strcpy(dest: copy, src: line);
134 tab1 = strchr(s: copy, c: '\t');
135 if (!tab1)
136 malformed_line(line, line_nr: insns);
137 s = tab1 + 1;
138 s += strspn(s: s, accept: " ");
139 tab2 = strchr(s: s, c: '\t');
140 if (!tab2)
141 malformed_line(line, line_nr: insns);
142 *tab2 = '\0'; /* Characters beyond tab2 aren't examined */
143 while (s < tab2) {
144 if (sscanf(s: s, format: "%x", &b) == 1) {
145 insn_buff[nb++] = (unsigned char) b;
146 s += 3;
147 } else
148 break;
149 }
150
151 /* Decode an instruction */
152 ret = insn_decode(&insn, insn_buff, sizeof(insn_buff),
153 x86_64 ? INSN_MODE_64 : INSN_MODE_32);
154
155 if (ret < 0 || insn.length != nb) {
156 warnings++;
157 pr_warn(fmt: "Found an x86 instruction decoder bug, "
158 "please report this.\n", sym);
159 pr_warn(fmt: "%s", line);
160 pr_warn(fmt: "objdump says %d bytes, but insn_get_length() "
161 "says %d\n", nb, insn.length);
162 if (verbose)
163 dump_insn(stderr, insn: &insn);
164 }
165 }
166 if (warnings)
167 pr_warn(fmt: "Decoded and checked %d instructions with %d "
168 "failures\n", insns, warnings);
169 else
170 fprintf(stdout, format: " %s: success: Decoded and checked %d"
171 " instructions\n", prog, insns);
172 return 0;
173}
174

source code of linux/arch/x86/tools/insn_decoder_test.c