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
 28const char *prog;
 29static int verbose;
 30static int x86_64;
 31
 32static 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
 42static 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
 49static 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
 59static 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
 70static 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
 88static 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
111int 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, ret;
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
152		/* Decode an instruction */
153		ret = insn_decode(&insn, insn_buff, sizeof(insn_buff),
154				  x86_64 ? INSN_MODE_64 : INSN_MODE_32);
155
156		if (ret < 0 || insn.length != nb) {
157			warnings++;
158			pr_warn("Found an x86 instruction decoder bug, "
159				"please report this.\n", sym);
160			pr_warn("%s", line);
161			pr_warn("objdump says %d bytes, but insn_get_length() "
162				"says %d\n", nb, insn.length);
163			if (verbose)
164				dump_insn(stderr, &insn);
165		}
166	}
167	if (warnings)
168		pr_warn("Decoded and checked %d instructions with %d "
169			"failures\n", insns, warnings);
170	else
171		fprintf(stdout, "%s: success: Decoded and checked %d"
172			" instructions\n", prog, insns);
173	return 0;
174}