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
14#define unlikely(cond) (cond)
15
16#include <asm/insn.h>
17#include <inat.c>
18#include <insn.c>
19
20/*
21 * Test of instruction analysis in general and insn_get_length() in
22 * particular. See if insn_get_length() and the disassembler agree
23 * on the length of each instruction in an elf disassembly.
24 *
25 * Usage: objdump -d a.out | awk -f objdump_reformat.awk | ./insn_decoder_test
26 */
27
28const char *prog;
29static int verbose;
30static int x86_64;
31
32static void usage(void)
33{
34 fprintf(stderr, "Usage: objdump -d a.out | awk -f objdump_reformat.awk"
35 " | %s [-y|-n] [-v]\n", prog);
36 fprintf(stderr, "\t-y 64bit mode\n");
37 fprintf(stderr, "\t-n 32bit mode\n");
38 fprintf(stderr, "\t-v verbose mode\n");
39 exit(1);
40}
41
42static void malformed_line(const char *line, int line_nr)
43{
44 fprintf(stderr, "%s: error: malformed line %d:\n%s",
45 prog, line_nr, line);
46 exit(3);
47}
48
49static void pr_warn(const char *fmt, ...)
50{
51 va_list ap;
52
53 fprintf(stderr, "%s: warning: ", prog);
54 va_start(ap, fmt);
55 vfprintf(stderr, fmt, ap);
56 va_end(ap);
57}
58
59static void dump_field(FILE *fp, const char *name, const char *indent,
60 struct insn_field *field)
61{
62 fprintf(fp, "%s.%s = {\n", indent, name);
63 fprintf(fp, "%s\t.value = %d, bytes[] = {%x, %x, %x, %x},\n",
64 indent, field->value, field->bytes[0], field->bytes[1],
65 field->bytes[2], field->bytes[3]);
66 fprintf(fp, "%s\t.got = %d, .nbytes = %d},\n", indent,
67 field->got, field->nbytes);
68}
69
70static void dump_insn(FILE *fp, struct insn *insn)
71{
72 fprintf(fp, "Instruction = {\n");
73 dump_field(fp, "prefixes", "\t", &insn->prefixes);
74 dump_field(fp, "rex_prefix", "\t", &insn->rex_prefix);
75 dump_field(fp, "vex_prefix", "\t", &insn->vex_prefix);
76 dump_field(fp, "opcode", "\t", &insn->opcode);
77 dump_field(fp, "modrm", "\t", &insn->modrm);
78 dump_field(fp, "sib", "\t", &insn->sib);
79 dump_field(fp, "displacement", "\t", &insn->displacement);
80 dump_field(fp, "immediate1", "\t", &insn->immediate1);
81 dump_field(fp, "immediate2", "\t", &insn->immediate2);
82 fprintf(fp, "\t.attr = %x, .opnd_bytes = %d, .addr_bytes = %d,\n",
83 insn->attr, insn->opnd_bytes, insn->addr_bytes);
84 fprintf(fp, "\t.length = %d, .x86_64 = %d, .kaddr = %p}\n",
85 insn->length, insn->x86_64, insn->kaddr);
86}
87
88static void parse_args(int argc, char **argv)
89{
90 int c;
91 prog = argv[0];
92 while ((c = getopt(argc, argv, "ynv")) != -1) {
93 switch (c) {
94 case 'y':
95 x86_64 = 1;
96 break;
97 case 'n':
98 x86_64 = 0;
99 break;
100 case 'v':
101 verbose = 1;
102 break;
103 default:
104 usage();
105 }
106 }
107}
108
109#define BUFSIZE 256
110
111int main(int argc, char **argv)
112{
113 char line[BUFSIZE], sym[BUFSIZE] = "<unknown>";
114 unsigned char insn_buff[16];
115 struct insn insn;
116 int insns = 0;
117 int warnings = 0;
118
119 parse_args(argc, argv);
120
121 while (fgets(line, BUFSIZE, stdin)) {
122 char copy[BUFSIZE], *s, *tab1, *tab2;
123 int nb = 0, ret;
124 unsigned int b;
125
126 if (line[0] == '<') {
127 /* Symbol line */
128 strcpy(sym, line);
129 continue;
130 }
131
132 insns++;
133 memset(insn_buff, 0, 16);
134 strcpy(copy, line);
135 tab1 = strchr(copy, '\t');
136 if (!tab1)
137 malformed_line(line, insns);
138 s = tab1 + 1;
139 s += strspn(s, " ");
140 tab2 = strchr(s, '\t');
141 if (!tab2)
142 malformed_line(line, insns);
143 *tab2 = '\0'; /* Characters beyond tab2 aren't examined */
144 while (s < tab2) {
145 if (sscanf(s, "%x", &b) == 1) {
146 insn_buff[nb++] = (unsigned char) b;
147 s += 3;
148 } else
149 break;
150 }
151
152 /* Decode an instruction */
153 ret = insn_decode(&insn, insn_buff, sizeof(insn_buff),
154 x86_64 ? INSN_MODE_64 : INSN_MODE_32);
155
156 if (ret < 0 || insn.length != nb) {
157 warnings++;
158 pr_warn("Found an x86 instruction decoder bug, "
159 "please report this.\n", sym);
160 pr_warn("%s", line);
161 pr_warn("objdump says %d bytes, but insn_get_length() "
162 "says %d\n", nb, insn.length);
163 if (verbose)
164 dump_insn(stderr, &insn);
165 }
166 }
167 if (warnings)
168 pr_warn("Decoded and checked %d instructions with %d "
169 "failures\n", insns, warnings);
170 else
171 fprintf(stdout, "%s: success: Decoded and checked %d"
172 " instructions\n", prog, insns);
173 return 0;
174}
175

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