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}