linux/arch/x86/tools/insn_decoder_test.c
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   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