arch/x86/tools/insn_decoder_test.c

   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
  28 const char *prog;
  29 static int verbose;
  30 static int x86_64;
  31
  32 static 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
  42 static 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
  49 static 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
  59 static 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
  70 static 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
  88 static 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
 111 int 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;
 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                 /* Decode an instruction */
 152                 insn_init(&insn, insn_buff, sizeof(insn_buff), x86_64);
 153                 insn_get_length(&insn);
 154                 if (insn.length != nb) {
 155                         warnings++;
 156                         pr_warn("Found an x86 instruction decoder bug, "
 157                                 "please report this.\n", sym);
 158                         pr_warn("%s", line);
 159                         pr_warn("objdump says %d bytes, but insn_get_length() "
 160                                 "says %d\n", nb, insn.length);
 161                         if (verbose)
 162                                 dump_insn(stderr, &insn);
 163                 }
 164         }
 165         if (warnings)
 166                 pr_warn("Decoded and checked %d instructions with %d "
 167                         "failures\n", insns, warnings);
 168         else
 169                 fprintf(stdout, "%s: success: Decoded and checked %d"
 170                         " instructions\n", prog, insns);
 171         return 0;
 172 }