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1/*
2 * x86 decoder sanity test - based on test_get_insn.c
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright (C) IBM Corporation, 2009
19 * Copyright (C) Hitachi, Ltd., 2011
20 */
21
22#include <stdlib.h>
23#include <stdio.h>
24#include <string.h>
25#include <assert.h>
26#include <unistd.h>
27#include <sys/types.h>
28#include <sys/stat.h>
29#include <fcntl.h>
30
31#define unlikely(cond) (cond)
32#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
33
34#include <asm/insn.h>
35#include <inat.c>
36#include <insn.c>
37
38/*
39 * Test of instruction analysis against tampering.
40 * Feed random binary to instruction decoder and ensure not to
41 * access out-of-instruction-buffer.
42 */
43
44#define DEFAULT_MAX_ITER 10000
45#define INSN_NOP 0x90
46
47static const char *prog; /* Program name */
48static int verbose; /* Verbosity */
49static int x86_64; /* x86-64 bit mode flag */
50static unsigned int seed; /* Random seed */
51static unsigned long iter_start; /* Start of iteration number */
52static unsigned long iter_end = DEFAULT_MAX_ITER; /* End of iteration number */
53static FILE *input_file; /* Input file name */
54
55static void usage(const char *err)
56{
57 if (err)
58 fprintf(stderr, "Error: %s\n\n", err);
59 fprintf(stderr, "Usage: %s [-y|-n|-v] [-s seed[,no]] [-m max] [-i input]\n", prog);
60 fprintf(stderr, "\t-y 64bit mode\n");
61 fprintf(stderr, "\t-n 32bit mode\n");
62 fprintf(stderr, "\t-v Verbosity(-vv dumps any decoded result)\n");
63 fprintf(stderr, "\t-s Give a random seed (and iteration number)\n");
64 fprintf(stderr, "\t-m Give a maximum iteration number\n");
65 fprintf(stderr, "\t-i Give an input file with decoded binary\n");
66 exit(1);
67}
68
69static void dump_field(FILE *fp, const char *name, const char *indent,
70 struct insn_field *field)
71{
72 fprintf(fp, "%s.%s = {\n", indent, name);
73 fprintf(fp, "%s\t.value = %d, bytes[] = {%x, %x, %x, %x},\n",
74 indent, field->value, field->bytes[0], field->bytes[1],
75 field->bytes[2], field->bytes[3]);
76 fprintf(fp, "%s\t.got = %d, .nbytes = %d},\n", indent,
77 field->got, field->nbytes);
78}
79
80static void dump_insn(FILE *fp, struct insn *insn)
81{
82 fprintf(fp, "Instruction = {\n");
83 dump_field(fp, "prefixes", "\t", &insn->prefixes);
84 dump_field(fp, "rex_prefix", "\t", &insn->rex_prefix);
85 dump_field(fp, "vex_prefix", "\t", &insn->vex_prefix);
86 dump_field(fp, "opcode", "\t", &insn->opcode);
87 dump_field(fp, "modrm", "\t", &insn->modrm);
88 dump_field(fp, "sib", "\t", &insn->sib);
89 dump_field(fp, "displacement", "\t", &insn->displacement);
90 dump_field(fp, "immediate1", "\t", &insn->immediate1);
91 dump_field(fp, "immediate2", "\t", &insn->immediate2);
92 fprintf(fp, "\t.attr = %x, .opnd_bytes = %d, .addr_bytes = %d,\n",
93 insn->attr, insn->opnd_bytes, insn->addr_bytes);
94 fprintf(fp, "\t.length = %d, .x86_64 = %d, .kaddr = %p}\n",
95 insn->length, insn->x86_64, insn->kaddr);
96}
97
98static void dump_stream(FILE *fp, const char *msg, unsigned long nr_iter,
99 unsigned char *insn_buf, struct insn *insn)
100{
101 int i;
102
103 fprintf(fp, "%s:\n", msg);
104
105 dump_insn(fp, insn);
106
107 fprintf(fp, "You can reproduce this with below command(s);\n");
108
109 /* Input a decoded instruction sequence directly */
110 fprintf(fp, " $ echo ");
111 for (i = 0; i < MAX_INSN_SIZE; i++)
112 fprintf(fp, " %02x", insn_buf[i]);
113 fprintf(fp, " | %s -i -\n", prog);
114
115 if (!input_file) {
116 fprintf(fp, "Or \n");
117 /* Give a seed and iteration number */
118 fprintf(fp, " $ %s -s 0x%x,%lu\n", prog, seed, nr_iter);
119 }
120}
121
122static void init_random_seed(void)
123{
124 int fd;
125
126 fd = open("/dev/urandom", O_RDONLY);
127 if (fd < 0)
128 goto fail;
129
130 if (read(fd, &seed, sizeof(seed)) != sizeof(seed))
131 goto fail;
132
133 close(fd);
134 return;
135fail:
136 usage("Failed to open /dev/urandom");
137}
138
139/* Read given instruction sequence from the input file */
140static int read_next_insn(unsigned char *insn_buf)
141{
142 char buf[256] = "", *tmp;
143 int i;
144
145 tmp = fgets(buf, ARRAY_SIZE(buf), input_file);
146 if (tmp == NULL || feof(input_file))
147 return 0;
148
149 for (i = 0; i < MAX_INSN_SIZE; i++) {
150 insn_buf[i] = (unsigned char)strtoul(tmp, &tmp, 16);
151 if (*tmp != ' ')
152 break;
153 }
154
155 return i;
156}
157
158static int generate_insn(unsigned char *insn_buf)
159{
160 int i;
161
162 if (input_file)
163 return read_next_insn(insn_buf);
164
165 /* Fills buffer with random binary up to MAX_INSN_SIZE */
166 for (i = 0; i < MAX_INSN_SIZE - 1; i += 2)
167 *(unsigned short *)(&insn_buf[i]) = random() & 0xffff;
168
169 while (i < MAX_INSN_SIZE)
170 insn_buf[i++] = random() & 0xff;
171
172 return i;
173}
174
175static void parse_args(int argc, char **argv)
176{
177 int c;
178 char *tmp = NULL;
179 int set_seed = 0;
180
181 prog = argv[0];
182 while ((c = getopt(argc, argv, "ynvs:m:i:")) != -1) {
183 switch (c) {
184 case 'y':
185 x86_64 = 1;
186 break;
187 case 'n':
188 x86_64 = 0;
189 break;
190 case 'v':
191 verbose++;
192 break;
193 case 'i':
194 if (strcmp("-", optarg) == 0)
195 input_file = stdin;
196 else
197 input_file = fopen(optarg, "r");
198 if (!input_file)
199 usage("Failed to open input file");
200 break;
201 case 's':
202 seed = (unsigned int)strtoul(optarg, &tmp, 0);
203 if (*tmp == ',') {
204 optarg = tmp + 1;
205 iter_start = strtoul(optarg, &tmp, 0);
206 }
207 if (*tmp != '\0' || tmp == optarg)
208 usage("Failed to parse seed");
209 set_seed = 1;
210 break;
211 case 'm':
212 iter_end = strtoul(optarg, &tmp, 0);
213 if (*tmp != '\0' || tmp == optarg)
214 usage("Failed to parse max_iter");
215 break;
216 default:
217 usage(NULL);
218 }
219 }
220
221 /* Check errors */
222 if (iter_end < iter_start)
223 usage("Max iteration number must be bigger than iter-num");
224
225 if (set_seed && input_file)
226 usage("Don't use input file (-i) with random seed (-s)");
227
228 /* Initialize random seed */
229 if (!input_file) {
230 if (!set_seed) /* No seed is given */
231 init_random_seed();
232 srand(seed);
233 }
234}
235
236int main(int argc, char **argv)
237{
238 struct insn insn;
239 int insns = 0;
240 int errors = 0;
241 unsigned long i;
242 unsigned char insn_buf[MAX_INSN_SIZE * 2];
243
244 parse_args(argc, argv);
245
246 /* Prepare stop bytes with NOPs */
247 memset(insn_buf + MAX_INSN_SIZE, INSN_NOP, MAX_INSN_SIZE);
248
249 for (i = 0; i < iter_end; i++) {
250 if (generate_insn(insn_buf) <= 0)
251 break;
252
253 if (i < iter_start) /* Skip to given iteration number */
254 continue;
255
256 /* Decode an instruction */
257 insn_init(&insn, insn_buf, x86_64);
258 insn_get_length(&insn);
259
260 if (insn.next_byte <= insn.kaddr ||
261 insn.kaddr + MAX_INSN_SIZE < insn.next_byte) {
262 /* Access out-of-range memory */
263 dump_stream(stderr, "Error: Found an access violation", i, insn_buf, &insn);
264 errors++;
265 } else if (verbose && !insn_complete(&insn))
266 dump_stream(stdout, "Info: Found an undecodable input", i, insn_buf, &insn);
267 else if (verbose >= 2)
268 dump_insn(stdout, &insn);
269 insns++;
270 }
271
272 fprintf(stdout, "%s: decoded and checked %d %s instructions with %d errors (seed:0x%x)\n", (errors) ? "Failure" : "Success", insns, (input_file) ? "given" : "random", errors, seed);
273
274 return errors ? 1 : 0;
275}