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, 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 }
175