1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * x86 decoder sanity test - based on test_get_insn.c 4 * 5 * Copyright (C) IBM Corporation, 2009 6 * Copyright (C) Hitachi, Ltd., 2011 7 */ 8 9 #include <stdlib.h> 10 #include <stdio.h> 11 #include <string.h> 12 #include <assert.h> 13 #include <unistd.h> 14 #include <sys/types.h> 15 #include <sys/stat.h> 16 #include <fcntl.h> 17 18 #define unlikely(cond) (cond) 19 #define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0])) 20 21 #include <asm/insn.h> 22 #include <inat.c> 23 #include <insn.c> 24 25 /* 26 * Test of instruction analysis against tampering. 27 * Feed random binary to instruction decoder and ensure not to 28 * access out-of-instruction-buffer. 29 */ 30 31 #define DEFAULT_MAX_ITER 10000 32 #define INSN_NOP 0x90 33 34 static const char *prog; /* Program name */ 35 static int verbose; /* Verbosity */ 36 static int x86_64; /* x86-64 bit mode flag */ 37 static unsigned int seed; /* Random seed */ 38 static unsigned long iter_start; /* Start of iteration number */ 39 static unsigned long iter_end = DEFAULT_MAX_ITER; /* End of iteration number */ 40 static FILE *input_file; /* Input file name */ 41 42 static void usage(const char *err) 43 { 44 if (err) 45 fprintf(stderr, "%s: Error: %s\n\n", prog, err); 46 fprintf(stderr, "Usage: %s [-y|-n|-v] [-s seed[,no]] [-m max] [-i input]\n", prog); 47 fprintf(stderr, "\t-y 64bit mode\n"); 48 fprintf(stderr, "\t-n 32bit mode\n"); 49 fprintf(stderr, "\t-v Verbosity(-vv dumps any decoded result)\n"); 50 fprintf(stderr, "\t-s Give a random seed (and iteration number)\n"); 51 fprintf(stderr, "\t-m Give a maximum iteration number\n"); 52 fprintf(stderr, "\t-i Give an input file with decoded binary\n"); 53 exit(1); 54 } 55 56 static void dump_field(FILE *fp, const char *name, const char *indent, 57 struct insn_field *field) 58 { 59 fprintf(fp, "%s.%s = {\n", indent, name); 60 fprintf(fp, "%s\t.value = %d, bytes[] = {%x, %x, %x, %x},\n", 61 indent, field->value, field->bytes[0], field->bytes[1], 62 field->bytes[2], field->bytes[3]); 63 fprintf(fp, "%s\t.got = %d, .nbytes = %d},\n", indent, 64 field->got, field->nbytes); 65 } 66 67 static void dump_insn(FILE *fp, struct insn *insn) 68 { 69 fprintf(fp, "Instruction = {\n"); 70 dump_field(fp, "prefixes", "\t", &insn->prefixes); 71 dump_field(fp, "rex_prefix", "\t", &insn->rex_prefix); 72 dump_field(fp, "vex_prefix", "\t", &insn->vex_prefix); 73 dump_field(fp, "opcode", "\t", &insn->opcode); 74 dump_field(fp, "modrm", "\t", &insn->modrm); 75 dump_field(fp, "sib", "\t", &insn->sib); 76 dump_field(fp, "displacement", "\t", &insn->displacement); 77 dump_field(fp, "immediate1", "\t", &insn->immediate1); 78 dump_field(fp, "immediate2", "\t", &insn->immediate2); 79 fprintf(fp, "\t.attr = %x, .opnd_bytes = %d, .addr_bytes = %d,\n", 80 insn->attr, insn->opnd_bytes, insn->addr_bytes); 81 fprintf(fp, "\t.length = %d, .x86_64 = %d, .kaddr = %p}\n", 82 insn->length, insn->x86_64, insn->kaddr); 83 } 84 85 static void dump_stream(FILE *fp, const char *msg, unsigned long nr_iter, 86 unsigned char *insn_buff, struct insn *insn) 87 { 88 int i; 89 90 fprintf(fp, "%s:\n", msg); 91 92 dump_insn(fp, insn); 93 94 fprintf(fp, "You can reproduce this with below command(s);\n"); 95 96 /* Input a decoded instruction sequence directly */ 97 fprintf(fp, " $ echo "); 98 for (i = 0; i < MAX_INSN_SIZE; i++) 99 fprintf(fp, " %02x", insn_buff[i]); 100 fprintf(fp, " | %s -i -\n", prog); 101 102 if (!input_file) { 103 fprintf(fp, "Or \n"); 104 /* Give a seed and iteration number */ 105 fprintf(fp, " $ %s -s 0x%x,%lu\n", prog, seed, nr_iter); 106 } 107 } 108 109 static void init_random_seed(void) 110 { 111 int fd; 112 113 fd = open("/dev/urandom", O_RDONLY); 114 if (fd < 0) 115 goto fail; 116 117 if (read(fd, &seed, sizeof(seed)) != sizeof(seed)) 118 goto fail; 119 120 close(fd); 121 return; 122 fail: 123 usage("Failed to open /dev/urandom"); 124 } 125 126 /* Read given instruction sequence from the input file */ 127 static int read_next_insn(unsigned char *insn_buff) 128 { 129 char buf[256] = "", *tmp; 130 int i; 131 132 tmp = fgets(buf, ARRAY_SIZE(buf), input_file); 133 if (tmp == NULL || feof(input_file)) 134 return 0; 135 136 for (i = 0; i < MAX_INSN_SIZE; i++) { 137 insn_buff[i] = (unsigned char)strtoul(tmp, &tmp, 16); 138 if (*tmp != ' ') 139 break; 140 } 141 142 return i; 143 } 144 145 static int generate_insn(unsigned char *insn_buff) 146 { 147 int i; 148 149 if (input_file) 150 return read_next_insn(insn_buff); 151 152 /* Fills buffer with random binary up to MAX_INSN_SIZE */ 153 for (i = 0; i < MAX_INSN_SIZE - 1; i += 2) 154 *(unsigned short *)(&insn_buff[i]) = random() & 0xffff; 155 156 while (i < MAX_INSN_SIZE) 157 insn_buff[i++] = random() & 0xff; 158 159 return i; 160 } 161 162 static void parse_args(int argc, char **argv) 163 { 164 int c; 165 char *tmp = NULL; 166 int set_seed = 0; 167 168 prog = argv[0]; 169 while ((c = getopt(argc, argv, "ynvs:m:i:")) != -1) { 170 switch (c) { 171 case 'y': 172 x86_64 = 1; 173 break; 174 case 'n': 175 x86_64 = 0; 176 break; 177 case 'v': 178 verbose++; 179 break; 180 case 'i': 181 if (strcmp("-", optarg) == 0) 182 input_file = stdin; 183 else 184 input_file = fopen(optarg, "r"); 185 if (!input_file) 186 usage("Failed to open input file"); 187 break; 188 case 's': 189 seed = (unsigned int)strtoul(optarg, &tmp, 0); 190 if (*tmp == ',') { 191 optarg = tmp + 1; 192 iter_start = strtoul(optarg, &tmp, 0); 193 } 194 if (*tmp != '\0' || tmp == optarg) 195 usage("Failed to parse seed"); 196 set_seed = 1; 197 break; 198 case 'm': 199 iter_end = strtoul(optarg, &tmp, 0); 200 if (*tmp != '\0' || tmp == optarg) 201 usage("Failed to parse max_iter"); 202 break; 203 default: 204 usage(NULL); 205 } 206 } 207 208 /* Check errors */ 209 if (iter_end < iter_start) 210 usage("Max iteration number must be bigger than iter-num"); 211 212 if (set_seed && input_file) 213 usage("Don't use input file (-i) with random seed (-s)"); 214 215 /* Initialize random seed */ 216 if (!input_file) { 217 if (!set_seed) /* No seed is given */ 218 init_random_seed(); 219 srand(seed); 220 } 221 } 222 223 int main(int argc, char **argv) 224 { 225 struct insn insn; 226 int insns = 0; 227 int errors = 0; 228 unsigned long i; 229 unsigned char insn_buff[MAX_INSN_SIZE * 2]; 230 231 parse_args(argc, argv); 232 233 /* Prepare stop bytes with NOPs */ 234 memset(insn_buff + MAX_INSN_SIZE, INSN_NOP, MAX_INSN_SIZE); 235 236 for (i = 0; i < iter_end; i++) { 237 if (generate_insn(insn_buff) <= 0) 238 break; 239 240 if (i < iter_start) /* Skip to given iteration number */ 241 continue; 242 243 /* Decode an instruction */ 244 insn_init(&insn, insn_buff, sizeof(insn_buff), x86_64); 245 insn_get_length(&insn); 246 247 if (insn.next_byte <= insn.kaddr || 248 insn.kaddr + MAX_INSN_SIZE < insn.next_byte) { 249 /* Access out-of-range memory */ 250 dump_stream(stderr, "Error: Found an access violation", i, insn_buff, &insn); 251 errors++; 252 } else if (verbose && !insn_complete(&insn)) 253 dump_stream(stdout, "Info: Found an undecodable input", i, insn_buff, &insn); 254 else if (verbose >= 2) 255 dump_insn(stdout, &insn); 256 insns++; 257 } 258 259 fprintf((errors) ? stderr : stdout, 260 "%s: %s: decoded and checked %d %s instructions with %d errors (seed:0x%x)\n", 261 prog, 262 (errors) ? "Failure" : "Success", 263 insns, 264 (input_file) ? "given" : "random", 265 errors, 266 seed); 267 268 return errors ? 1 : 0; 269 } 270