266 lines
6.6 KiB
C
266 lines
6.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* x86 decoder sanity test - based on test_get_insn.c
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*
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* Copyright (C) IBM Corporation, 2009
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* Copyright (C) Hitachi, Ltd., 2011
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <assert.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <asm/insn.h>
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#include <inat.c>
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#include <insn.c>
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/*
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* Test of instruction analysis against tampering.
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* Feed random binary to instruction decoder and ensure not to
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* access out-of-instruction-buffer.
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*/
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#define DEFAULT_MAX_ITER 10000
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#define INSN_NOP 0x90
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static const char *prog; /* Program name */
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static int verbose; /* Verbosity */
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static int x86_64; /* x86-64 bit mode flag */
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static unsigned int seed; /* Random seed */
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static unsigned long iter_start; /* Start of iteration number */
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static unsigned long iter_end = DEFAULT_MAX_ITER; /* End of iteration number */
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static FILE *input_file; /* Input file name */
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static void usage(const char *err)
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{
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if (err)
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fprintf(stderr, "%s: Error: %s\n\n", prog, err);
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fprintf(stderr, "Usage: %s [-y|-n|-v] [-s seed[,no]] [-m max] [-i input]\n", prog);
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fprintf(stderr, "\t-y 64bit mode\n");
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fprintf(stderr, "\t-n 32bit mode\n");
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fprintf(stderr, "\t-v Verbosity(-vv dumps any decoded result)\n");
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fprintf(stderr, "\t-s Give a random seed (and iteration number)\n");
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fprintf(stderr, "\t-m Give a maximum iteration number\n");
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fprintf(stderr, "\t-i Give an input file with decoded binary\n");
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exit(1);
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}
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static void dump_field(FILE *fp, const char *name, const char *indent,
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struct insn_field *field)
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{
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fprintf(fp, "%s.%s = {\n", indent, name);
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fprintf(fp, "%s\t.value = %d, bytes[] = {%x, %x, %x, %x},\n",
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indent, field->value, field->bytes[0], field->bytes[1],
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field->bytes[2], field->bytes[3]);
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fprintf(fp, "%s\t.got = %d, .nbytes = %d},\n", indent,
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field->got, field->nbytes);
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}
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static void dump_insn(FILE *fp, struct insn *insn)
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{
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fprintf(fp, "Instruction = {\n");
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dump_field(fp, "prefixes", "\t", &insn->prefixes);
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dump_field(fp, "rex_prefix", "\t", &insn->rex_prefix);
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dump_field(fp, "vex_prefix", "\t", &insn->vex_prefix);
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dump_field(fp, "opcode", "\t", &insn->opcode);
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dump_field(fp, "modrm", "\t", &insn->modrm);
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dump_field(fp, "sib", "\t", &insn->sib);
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dump_field(fp, "displacement", "\t", &insn->displacement);
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dump_field(fp, "immediate1", "\t", &insn->immediate1);
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dump_field(fp, "immediate2", "\t", &insn->immediate2);
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fprintf(fp, "\t.attr = %x, .opnd_bytes = %d, .addr_bytes = %d,\n",
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insn->attr, insn->opnd_bytes, insn->addr_bytes);
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fprintf(fp, "\t.length = %d, .x86_64 = %d, .kaddr = %p}\n",
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insn->length, insn->x86_64, insn->kaddr);
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}
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static void dump_stream(FILE *fp, const char *msg, unsigned long nr_iter,
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unsigned char *insn_buff, struct insn *insn)
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{
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int i;
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fprintf(fp, "%s:\n", msg);
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dump_insn(fp, insn);
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fprintf(fp, "You can reproduce this with below command(s);\n");
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/* Input a decoded instruction sequence directly */
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fprintf(fp, " $ echo ");
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for (i = 0; i < MAX_INSN_SIZE; i++)
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fprintf(fp, " %02x", insn_buff[i]);
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fprintf(fp, " | %s -i -\n", prog);
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if (!input_file) {
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fprintf(fp, "Or \n");
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/* Give a seed and iteration number */
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fprintf(fp, " $ %s -s 0x%x,%lu\n", prog, seed, nr_iter);
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}
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}
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static void init_random_seed(void)
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{
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int fd;
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fd = open("/dev/urandom", O_RDONLY);
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if (fd < 0)
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goto fail;
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if (read(fd, &seed, sizeof(seed)) != sizeof(seed))
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goto fail;
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close(fd);
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return;
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fail:
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usage("Failed to open /dev/urandom");
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}
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/* Read given instruction sequence from the input file */
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static int read_next_insn(unsigned char *insn_buff)
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{
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char buf[256] = "", *tmp;
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int i;
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tmp = fgets(buf, ARRAY_SIZE(buf), input_file);
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if (tmp == NULL || feof(input_file))
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return 0;
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for (i = 0; i < MAX_INSN_SIZE; i++) {
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insn_buff[i] = (unsigned char)strtoul(tmp, &tmp, 16);
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if (*tmp != ' ')
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break;
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}
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return i;
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}
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static int generate_insn(unsigned char *insn_buff)
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{
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int i;
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if (input_file)
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return read_next_insn(insn_buff);
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/* Fills buffer with random binary up to MAX_INSN_SIZE */
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for (i = 0; i < MAX_INSN_SIZE - 1; i += 2)
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*(unsigned short *)(&insn_buff[i]) = random() & 0xffff;
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while (i < MAX_INSN_SIZE)
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insn_buff[i++] = random() & 0xff;
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return i;
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}
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static void parse_args(int argc, char **argv)
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{
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int c;
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char *tmp = NULL;
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int set_seed = 0;
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prog = argv[0];
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while ((c = getopt(argc, argv, "ynvs:m:i:")) != -1) {
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switch (c) {
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case 'y':
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x86_64 = 1;
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break;
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case 'n':
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x86_64 = 0;
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break;
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case 'v':
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verbose++;
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break;
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case 'i':
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if (strcmp("-", optarg) == 0)
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input_file = stdin;
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else
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input_file = fopen(optarg, "r");
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if (!input_file)
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usage("Failed to open input file");
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break;
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case 's':
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seed = (unsigned int)strtoul(optarg, &tmp, 0);
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if (*tmp == ',') {
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optarg = tmp + 1;
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iter_start = strtoul(optarg, &tmp, 0);
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}
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if (*tmp != '\0' || tmp == optarg)
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usage("Failed to parse seed");
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set_seed = 1;
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break;
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case 'm':
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iter_end = strtoul(optarg, &tmp, 0);
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if (*tmp != '\0' || tmp == optarg)
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usage("Failed to parse max_iter");
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break;
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default:
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usage(NULL);
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}
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}
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/* Check errors */
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if (iter_end < iter_start)
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usage("Max iteration number must be bigger than iter-num");
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if (set_seed && input_file)
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usage("Don't use input file (-i) with random seed (-s)");
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/* Initialize random seed */
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if (!input_file) {
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if (!set_seed) /* No seed is given */
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init_random_seed();
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srand(seed);
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}
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}
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int main(int argc, char **argv)
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{
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int insns = 0, ret;
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struct insn insn;
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int errors = 0;
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unsigned long i;
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unsigned char insn_buff[MAX_INSN_SIZE * 2];
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parse_args(argc, argv);
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/* Prepare stop bytes with NOPs */
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memset(insn_buff + MAX_INSN_SIZE, INSN_NOP, MAX_INSN_SIZE);
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for (i = 0; i < iter_end; i++) {
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if (generate_insn(insn_buff) <= 0)
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break;
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if (i < iter_start) /* Skip to given iteration number */
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continue;
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/* Decode an instruction */
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ret = insn_decode(&insn, insn_buff, sizeof(insn_buff),
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x86_64 ? INSN_MODE_64 : INSN_MODE_32);
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if (insn.next_byte <= insn.kaddr ||
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insn.kaddr + MAX_INSN_SIZE < insn.next_byte) {
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/* Access out-of-range memory */
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dump_stream(stderr, "Error: Found an access violation", i, insn_buff, &insn);
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errors++;
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} else if (verbose && ret < 0)
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dump_stream(stdout, "Info: Found an undecodable input", i, insn_buff, &insn);
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else if (verbose >= 2)
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dump_insn(stdout, &insn);
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insns++;
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}
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fprintf((errors) ? stderr : stdout,
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"%s: %s: decoded and checked %d %s instructions with %d errors (seed:0x%x)\n",
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prog,
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(errors) ? "Failure" : "Success",
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insns,
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(input_file) ? "given" : "random",
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errors,
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seed);
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return errors ? 1 : 0;
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}
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