linux/arch/x86/tools/insn_decoder_test.c
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   1/*
   2 * This program is free software; you can redistribute it and/or modify
   3 * it under the terms of the GNU General Public License as published by
   4 * the Free Software Foundation; either version 2 of the License, or
   5 * (at your option) any later version.
   6 *
   7 * This program is distributed in the hope that it will be useful,
   8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10 * GNU General Public License for more details.
  11 *
  12 * Copyright (C) IBM Corporation, 2009
  13 */
  14
  15#include <stdlib.h>
  16#include <stdio.h>
  17#include <string.h>
  18#include <assert.h>
  19#include <unistd.h>
  20#include <stdarg.h>
  21
  22#define unlikely(cond) (cond)
  23
  24#include <asm/insn.h>
  25#include <inat.c>
  26#include <insn.c>
  27
  28/*
  29 * Test of instruction analysis in general and insn_get_length() in
  30 * particular.  See if insn_get_length() and the disassembler agree
  31 * on the length of each instruction in an elf disassembly.
  32 *
  33 * Usage: objdump -d a.out | awk -f objdump_reformat.awk | ./insn_decoder_test
  34 */
  35
  36const char *prog;
  37static int verbose;
  38static int x86_64;
  39
  40static void usage(void)
  41{
  42        fprintf(stderr, "Usage: objdump -d a.out | awk -f objdump_reformat.awk"
  43                " | %s [-y|-n] [-v]\n", prog);
  44        fprintf(stderr, "\t-y   64bit mode\n");
  45        fprintf(stderr, "\t-n   32bit mode\n");
  46        fprintf(stderr, "\t-v   verbose mode\n");
  47        exit(1);
  48}
  49
  50static void malformed_line(const char *line, int line_nr)
  51{
  52        fprintf(stderr, "%s: error: malformed line %d:\n%s",
  53                prog, line_nr, line);
  54        exit(3);
  55}
  56
  57static void pr_warn(const char *fmt, ...)
  58{
  59        va_list ap;
  60
  61        fprintf(stderr, "%s: warning: ", prog);
  62        va_start(ap, fmt);
  63        vfprintf(stderr, fmt, ap);
  64        va_end(ap);
  65}
  66
  67static void dump_field(FILE *fp, const char *name, const char *indent,
  68                       struct insn_field *field)
  69{
  70        fprintf(fp, "%s.%s = {\n", indent, name);
  71        fprintf(fp, "%s\t.value = %d, bytes[] = {%x, %x, %x, %x},\n",
  72                indent, field->value, field->bytes[0], field->bytes[1],
  73                field->bytes[2], field->bytes[3]);
  74        fprintf(fp, "%s\t.got = %d, .nbytes = %d},\n", indent,
  75                field->got, field->nbytes);
  76}
  77
  78static void dump_insn(FILE *fp, struct insn *insn)
  79{
  80        fprintf(fp, "Instruction = {\n");
  81        dump_field(fp, "prefixes", "\t",        &insn->prefixes);
  82        dump_field(fp, "rex_prefix", "\t",      &insn->rex_prefix);
  83        dump_field(fp, "vex_prefix", "\t",      &insn->vex_prefix);
  84        dump_field(fp, "opcode", "\t",          &insn->opcode);
  85        dump_field(fp, "modrm", "\t",           &insn->modrm);
  86        dump_field(fp, "sib", "\t",             &insn->sib);
  87        dump_field(fp, "displacement", "\t",    &insn->displacement);
  88        dump_field(fp, "immediate1", "\t",      &insn->immediate1);
  89        dump_field(fp, "immediate2", "\t",      &insn->immediate2);
  90        fprintf(fp, "\t.attr = %x, .opnd_bytes = %d, .addr_bytes = %d,\n",
  91                insn->attr, insn->opnd_bytes, insn->addr_bytes);
  92        fprintf(fp, "\t.length = %d, .x86_64 = %d, .kaddr = %p}\n",
  93                insn->length, insn->x86_64, insn->kaddr);
  94}
  95
  96static void parse_args(int argc, char **argv)
  97{
  98        int c;
  99        prog = argv[0];
 100        while ((c = getopt(argc, argv, "ynv")) != -1) {
 101                switch (c) {
 102                case 'y':
 103                        x86_64 = 1;
 104                        break;
 105                case 'n':
 106                        x86_64 = 0;
 107                        break;
 108                case 'v':
 109                        verbose = 1;
 110                        break;
 111                default:
 112                        usage();
 113                }
 114        }
 115}
 116
 117#define BUFSIZE 256
 118
 119int main(int argc, char **argv)
 120{
 121        char line[BUFSIZE], sym[BUFSIZE] = "<unknown>";
 122        unsigned char insn_buf[16];
 123        struct insn insn;
 124        int insns = 0;
 125        int warnings = 0;
 126
 127        parse_args(argc, argv);
 128
 129        while (fgets(line, BUFSIZE, stdin)) {
 130                char copy[BUFSIZE], *s, *tab1, *tab2;
 131                int nb = 0;
 132                unsigned int b;
 133
 134                if (line[0] == '<') {
 135                        /* Symbol line */
 136                        strcpy(sym, line);
 137                        continue;
 138                }
 139
 140                insns++;
 141                memset(insn_buf, 0, 16);
 142                strcpy(copy, line);
 143                tab1 = strchr(copy, '\t');
 144                if (!tab1)
 145                        malformed_line(line, insns);
 146                s = tab1 + 1;
 147                s += strspn(s, " ");
 148                tab2 = strchr(s, '\t');
 149                if (!tab2)
 150                        malformed_line(line, insns);
 151                *tab2 = '\0';   /* Characters beyond tab2 aren't examined */
 152                while (s < tab2) {
 153                        if (sscanf(s, "%x", &b) == 1) {
 154                                insn_buf[nb++] = (unsigned char) b;
 155                                s += 3;
 156                        } else
 157                                break;
 158                }
 159                /* Decode an instruction */
 160                insn_init(&insn, insn_buf, sizeof(insn_buf), x86_64);
 161                insn_get_length(&insn);
 162                if (insn.length != nb) {
 163                        warnings++;
 164                        pr_warn("Found an x86 instruction decoder bug, "
 165                                "please report this.\n", sym);
 166                        pr_warn("%s", line);
 167                        pr_warn("objdump says %d bytes, but insn_get_length() "
 168                                "says %d\n", nb, insn.length);
 169                        if (verbose)
 170                                dump_insn(stderr, &insn);
 171                }
 172        }
 173        if (warnings)
 174                pr_warn("Decoded and checked %d instructions with %d "
 175                        "failures\n", insns, warnings);
 176        else
 177                fprintf(stdout, "%s: success: Decoded and checked %d"
 178                        " instructions\n", prog, insns);
 179        return 0;
 180}
 181