arch/x86/tools/insn_decoder_test.c

   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
  36 const char *prog;
  37 static int verbose;
  38 static int x86_64;
  39
  40 static 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
  50 static 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
  57 static 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
  67 static 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
  78 static 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
  96 static 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
 119 int 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 }