https://github.com/akkartik/mu/blob/master/subx/031check_operands.cc
1
2
3
4 :(scenario check_missing_imm8_operand)
5 % Hide_errors = true;
6 == 0x1
7 cd
8 +error: 'cd' (software interrupt): missing imm8 operand
9
10 :(before "Pack Operands(segment code)")
11 check_operands(code);
12 if (trace_contains_errors()) return;
13
14 :(code)
15 void check_operands(const segment& code) {
16 trace(99, "transform") << "-- check operands" << end();
17 for (int i = 0; i < SIZE(code.lines); ++i) {
18 check_operands(code.lines.at(i));
19 if (trace_contains_errors()) return;
20 }
21 }
22
23 void check_operands(const line& inst) {
24 word op = preprocess_op(inst.words.at(0));
25 if (op.data == "0f") {
26 check_operands_0f(inst);
27 return;
28 }
29 if (op.data == "f3") {
30 check_operands_f3(inst);
31 return;
32 }
33 check_operands(inst, op);
34 }
35
36 word preprocess_op(word op) {
37 op.data = tolower(op.data.c_str());
38
39 if (starts_with(op.data, "0x"))
40 op.data = op.data.substr(2);
41 if (SIZE(op.data) == 1)
42 op.data = string("0")+op.data;
43 return op;
44 }
45
46 void test_preprocess_op() {
47 word w1; w1.data = "0xf";
48 word w2; w2.data = "0f";
49 CHECK_EQ(preprocess_op(w1).data, preprocess_op(w2).data);
50 }
51
52
53
54
55
56 :(before "End Types")
57 enum operand_type {
58
59 MODRM,
60 SUBOP,
61 DISP8,
62 DISP16,
63 DISP32,
64 IMM8,
65 IMM32,
66 NUM_OPERAND_TYPES
67 };
68 :(before "End Globals")
69 vector<string> Operand_type_name;
70 map<string, operand_type> Operand_type;
71 :(before "End One-time Setup")
72 init_op_types();
73 :(code)
74 void init_op_types() {
75 assert(NUM_OPERAND_TYPES <= 8);
76 Operand_type_name.resize(NUM_OPERAND_TYPES);
77
78 DEF(MODRM);
79 DEF(SUBOP);
80 DEF(DISP8);
81 DEF(DISP16);
82 DEF(DISP32);
83 DEF(IMM8);
84 DEF(IMM32);
85
86 }
87
88 :(before "End Globals")
89 map<string, uint8_t> Permitted_operands;
90 const uint8_t INVALID_OPERANDS = 0xff;
91 :(before "End One-time Setup")
92 init_permitted_operands();
93 :(code)
94 void init_permitted_operands() {
95
96
97 put(Permitted_operands, "f4", 0x00);
98
99 put(Permitted_operands, "40", 0x00);
100 put(Permitted_operands, "41", 0x00);
101 put(Permitted_operands, "42", 0x00);
102 put(Permitted_operands, "43", 0x00);
103 put(Permitted_operands, "44", 0x00);
104 put(Permitted_operands, "45", 0x00);
105 put(Permitted_operands, "46", 0x00);
106 put(Permitted_operands, "47", 0x00);
107
108 put(Permitted_operands, "48", 0x00);
109 put(Permitted_operands, "49", 0x00);
110 put(Permitted_operands, "4a", 0x00);
111 put(Permitted_operands, "4b", 0x00);
112 put(Permitted_operands, "4c", 0x00);
113 put(Permitted_operands, "4d", 0x00);
114 put(Permitted_operands, "4e", 0x00);
115 put(Permitted_operands, "4f", 0x00);
116
117 put(Permitted_operands, "50", 0x00);
118 put(Permitted_operands, "51", 0x00);
119 put(Permitted_operands, "52", 0x00);
120 put(Permitted_operands, "53", 0x00);
121 put(Permitted_operands, "54", 0x00);
122 put(Permitted_operands, "55", 0x00);
123 put(Permitted_operands, "56", 0x00);
124 put(Permitted_operands, "57", 0x00);
125
126 put(Permitted_operands, "58", 0x00);
127 put(Permitted_operands, "59", 0x00);
128 put(Permitted_operands, "5a", 0x00);
129 put(Permitted_operands, "5b", 0x00);
130 put(Permitted_operands, "5c", 0x00);
131 put(Permitted_operands, "5d", 0x00);
132 put(Permitted_operands, "5e", 0x00);
133 put(Permitted_operands, "5f", 0x00);
134
135 put(Permitted_operands, "c3", 0x00);
136
137
138
139
140
141
142 put(Permitted_operands, "eb", 0x04);
143 put(Permitted_operands, "74", 0x04);
144 put(Permitted_operands, "75", 0x04);
145 put(Permitted_operands, "7c", 0x04);
146 put(Permitted_operands, "7d", 0x04);
147 put(Permitted_operands, "7e", 0x04);
148 put(Permitted_operands, "7f", 0x04);
149
150
151
152
153 put(Permitted_operands, "e8", 0x10);
154 put(Permitted_operands, "e9", 0x10);
155
156
157
158
159 put(Permitted_operands, "cd", 0x20);
160
161
162
163
164 put(Permitted_operands, "05", 0x40);
165 put(Permitted_operands, "2d", 0x40);
166 put(Permitted_operands, "25", 0x40);
167 put(Permitted_operands, "0d", 0x40);
168 put(Permitted_operands, "35", 0x40);
169 put(Permitted_operands, "3d", 0x40);
170 put(Permitted_operands, "68", 0x40);
171
172 put(Permitted_operands, "b8", 0x40);
173 put(Permitted_operands, "b9", 0x40);
174 put(Permitted_operands, "ba", 0x40);
175 put(Permitted_operands, "bb", 0x40);
176 put(Permitted_operands, "bc", 0x40);
177 put(Permitted_operands, "bd", 0x40);
178 put(Permitted_operands, "be", 0x40);
179 put(Permitted_operands, "bf", 0x40);
180
181
182
183
184
185
186 put(Permitted_operands, "01", 0x01);
187 put(Permitted_operands, "03", 0x01);
188
189 put(Permitted_operands, "29", 0x01);
190 put(Permitted_operands, "2b", 0x01);
191
192 put(Permitted_operands, "21", 0x01);
193 put(Permitted_operands, "23", 0x01);
194
195 put(Permitted_operands, "09", 0x01);
196 put(Permitted_operands, "0b", 0x01);
197
198 put(Permitted_operands, "31", 0x01);
199 put(Permitted_operands, "33", 0x01);
200
201 put(Permitted_operands, "39", 0x01);
202 put(Permitted_operands, "3b", 0x01);
203
204 put(Permitted_operands, "88", 0x01);
205 put(Permitted_operands, "89", 0x01);
206 put(Permitted_operands, "8a", 0x01);
207 put(Permitted_operands, "8b", 0x01);
208
209 put(Permitted_operands, "87", 0x01);
210
211 put(Permitted_operands, "8d", 0x01);
212
213 put(Permitted_operands, "8f", 0x01);
214
215
216
217
218 put(Permitted_operands, "f7", 0x03);
219 put(Permitted_operands, "ff", 0x03);
220
221
222
223
224 put(Permitted_operands, "c7", 0x41);
225
226
227
228
229 put(Permitted_operands, "81", 0x43);
230
231
232 }
233
234 :(code)
235
236
237
238
239 void check_operands(const line& inst, const word& op) {
240 if (!is_hex_byte(op)) return;
241 uint8_t expected_bitvector = get(Permitted_operands, op.data);
242 if (HAS(expected_bitvector, MODRM)) {
243 check_operands_modrm(inst, op);
244 compare_bitvector_modrm(inst, expected_bitvector, op);
245 }
246 else {
247 compare_bitvector(inst, expected_bitvector, op);
248 }
249 }
250
251
252
253 void compare_bitvector(const line& inst, uint8_t expected, const word& op) {
254 if (all_hex_bytes(inst) && has_operands(inst)) return;
255 uint8_t bitvector = compute_operand_bitvector(inst);
256 if (trace_contains_errors()) return;
257 if (bitvector == expected) return;
258 for (int i = 0; i < NUM_OPERAND_TYPES; ++i, bitvector >>= 1, expected >>= 1) {
259
260 if ((bitvector & 0x1) == (expected & 0x1)) continue;
261 const string& optype = Operand_type_name.at(i);
262 if ((bitvector & 0x1) > (expected & 0x1))
263 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << optype << " operand\n" << end();
264 else
265 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": missing " << optype << " operand\n" << end();
266
267 }
268
269 }
270
271 string maybe_name(const word& op) {
272 if (!is_hex_byte(op)) return "";
273 if (!contains_key(Name, op.data)) return "";
274
275 const string& s = get(Name, op.data);
276 return " ("+s.substr(0, s.find(" ("))+')';
277 }
278
279 uint32_t compute_operand_bitvector(const line& inst) {
280 uint32_t bitvector = 0;
281 for (int i = 1; i < SIZE(inst.words); ++i) {
282 bitvector = bitvector | bitvector_for_operand(inst.words.at(i));
283 if (trace_contains_errors()) return INVALID_OPERANDS;
284 }
285 return bitvector;
286 }
287
288 bool has_operands(const line& inst) {
289 return SIZE(inst.words) > first_operand(inst);
290 }
291
292 int first_operand(const line& inst) {
293 if (inst.words.at(0).data == "0f") return 2;
294 if (inst.words.at(0).data == "f2" || inst.words.at(0).data == "f3") {
295 if (inst.words.at(1).data == "0f")
296 return 3;
297 else
298 return 2;
299 }
300 return 1;
301 }
302
303
304
305 uint32_t bitvector_for_operand(const word& w) {
306 uint32_t bv = 0;
307 bool found = false;
308 for (int i = 0; i < SIZE(w.metadata); ++i) {
309 const string& curr = w.metadata.at(i);
310 if (!contains_key(Operand_type, curr)) continue;
311 if (found) {
312 raise << "'" << w.original << "' has conflicting operand types; it should have only one\n" << end();
313 return INVALID_OPERANDS;
314 }
315 bv = (1 << get(Operand_type, curr));
316 found = true;
317 }
318 return bv;
319 }
320
321 :(scenario conflicting_operand_type)
322 % Hide_errors = true;
323 == 0x1
324 cd/software-interrupt 80/imm8/imm32
325 +error: '80/imm8/imm32' has conflicting operand types; it should have only one
326
327
328
329
330 :(scenario check_missing_mod_operand)
331 % Hide_errors = true;
332 == 0x1
333 81 0/add/subop 3/rm32/ebx 1/imm32
334 +error: '81 0/add/subop 3/rm32/ebx 1/imm32' (combine rm32 with imm32 based on subop): missing mod operand
335
336 :(code)
337 void check_operands_modrm(const line& inst, const word& op) {
338 if (all_hex_bytes(inst)) return;
339 check_operand_metadata_present(inst, "mod", op);
340 check_operand_metadata_present(inst, "rm32", op);
341
342 if (op.data == "81" || op.data == "8f" || op.data == "ff") {
343 check_operand_metadata_present(inst, "subop", op);
344 check_operand_metadata_absent(inst, "r32", op, "should be replaced by subop");
345 }
346 if (trace_contains_errors()) return;
347 if (metadata(inst, "rm32").data != "4") return;
348
349 uint8_t mod = hex_byte(metadata(inst, "mod").data);
350 if (mod != 3) {
351 check_operand_metadata_present(inst, "base", op);
352 check_operand_metadata_present(inst, "index", op);
353 }
354 else {
355 check_operand_metadata_absent(inst, "base", op, "direct mode");
356 check_operand_metadata_absent(inst, "index", op, "direct mode");
357 }
358
359 }
360
361
362
363
364 void compare_bitvector_modrm(const line& inst, uint8_t expected, const word& op) {
365 if (all_hex_bytes(inst) && has_operands(inst)) return;
366 uint8_t bitvector = compute_operand_bitvector(inst);
367 if (trace_contains_errors()) return;
368 expected = CLEAR(expected, MODRM);
369 if (bitvector == expected) return;
370 for (int i = 0; i < NUM_OPERAND_TYPES; ++i, bitvector >>= 1, expected >>= 1) {
371
372 if ((bitvector & 0x1) == (expected & 0x1)) continue;
373 const string& optype = Operand_type_name.at(i);
374 if (i == DISP8) {
375 int32_t mod = parse_int(metadata(inst, "mod").data);
376 if (mod != 1)
377 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << optype << " operand\n" << end();
378 continue;
379 }
380 if (i == DISP32) {
381 int32_t mod = parse_int(metadata(inst, "mod").data);
382 int32_t rm32 = parse_int(metadata(inst, "rm32").data);
383 if (mod == 0 && rm32 == 5)
384 ;
385 else if (mod != 2)
386 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << optype << " operand\n" << end();
387 continue;
388 }
389 if ((bitvector & 0x1) > (expected & 0x1))
390 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << optype << " operand\n" << end();
391 else
392 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": missing " << optype << " operand\n" << end();
393
394 }
395
396 }
397
398 void check_operand_metadata_present(const line& inst, const string& type, const word& op) {
399 if (!has_operand_metadata(inst, type))
400 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": missing " << type << " operand\n" << end();
401 }
402
403 void check_operand_metadata_absent(const line& inst, const string& type, const word& op, const string& msg) {
404 if (has_operand_metadata(inst, type))
405 raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << type << " operand (" << msg << ")\n" << end();
406 }
407
408 :(scenarios transform)
409 :(scenario modrm_with_displacement)
410 % Reg[EAX].u = 0x1;
411 == 0x1
412
413 8b/copy 1/mod/lookup+disp8 0/rm32/EAX 2/r32/EDX 4/disp8
414 $error: 0
415 :(scenarios run)
416
417 :(scenario conflicting_operands_in_modrm_instruction)
418 % Hide_errors = true;
419 == 0x1
420 01/add 0/mod 3/mod
421 +error: '01/add 0/mod 3/mod' has conflicting mod operands
422
423 :(scenario conflicting_operand_type_modrm)
424 % Hide_errors = true;
425 == 0x1
426 01/add 0/mod 3/rm32/r32
427 +error: '3/rm32/r32' has conflicting operand types; it should have only one
428
429 :(scenario check_missing_rm32_operand)
430 % Hide_errors = true;
431 == 0x1
432 81 0/add/subop 0/mod 1/imm32
433 +error: '81 0/add/subop 0/mod 1/imm32' (combine rm32 with imm32 based on subop): missing rm32 operand
434
435 :(scenario check_missing_subop_operand)
436 % Hide_errors = true;
437 == 0x1
438 81 0/mod 3/rm32/ebx 1/imm32
439 +error: '81 0/mod 3/rm32/ebx 1/imm32' (combine rm32 with imm32 based on subop): missing subop operand
440
441 :(scenario check_missing_base_operand)
442 % Hide_errors = true;
443 == 0x1
444 81 0/add/subop 0/mod/indirect 4/rm32/use-sib 1/imm32
445 +error: '81 0/add/subop 0/mod/indirect 4/rm32/use-sib 1/imm32' (combine rm32 with imm32 based on subop): missing base operand
446
447 :(scenario check_missing_index_operand)
448 % Hide_errors = true;
449 == 0x1
450 81 0/add/subop 0/mod/indirect 4/rm32/use-sib 0/base 1/imm32
451 +error: '81 0/add/subop 0/mod/indirect 4/rm32/use-sib 0/base 1/imm32' (combine rm32 with imm32 based on subop): missing index operand
452
453 :(scenario check_missing_base_operand_2)
454 % Hide_errors = true;
455 == 0x1
456 81 0/add/subop 0/mod/indirect 4/rm32/use-sib 2/index 3/scale 1/imm32
457 +error: '81 0/add/subop 0/mod/indirect 4/rm32/use-sib 2/index 3/scale 1/imm32' (combine rm32 with imm32 based on subop): missing base operand
458
459 :(scenario check_extra_displacement)
460 % Hide_errors = true;
461 == 0x1
462 89/copy 0/mod/indirect 0/rm32/EAX 1/r32/ECX 4/disp8
463 +error: '89/copy 0/mod/indirect 0/rm32/EAX 1/r32/ECX 4/disp8' (copy r32 to rm32): unexpected disp8 operand
464
465 :(scenario check_base_operand_not_needed_in_direct_mode)
466 == 0x1
467 81 0/add/subop 3/mod/indirect 4/rm32/use-sib 1/imm32
468 $error: 0
469
470
471
472 :(code)
473 void check_operands_0f(const line& inst) {
474 assert(inst.words.at(0).data == "0f");
475 if (SIZE(inst.words) == 1) {
476 raise << "opcode '0f' requires a second opcode\n" << end();
477 return;
478 }
479 word op = preprocess_op(inst.words.at(1));
480 if (!contains_key(Name_0f, op.data)) {
481 raise << "unknown 2-byte opcode '0f " << op.data << "'\n" << end();
482 return;
483 }
484 check_operands_0f(inst, op);
485 }
486
487 void check_operands_f3(const line& ) {
488 raise << "no supported opcodes starting with f3\n" << end();
489 }
490
491 :(scenario check_missing_disp32_operand)
492 % Hide_errors = true;
493 == 0x1
494
495
496
497 0f 84
498 +error: '0f 84' (jump disp32 bytes away if equal, if ZF is set): missing disp32 operand
499
500 :(before "End Globals")
501 map<string, uint8_t> Permitted_operands_0f;
502 :(before "End Init Permitted Operands")
503
504
505
506 put_new(Permitted_operands_0f, "84", 0x10);
507 put_new(Permitted_operands_0f, "85", 0x10);
508 put_new(Permitted_operands_0f, "8c", 0x10);
509 put_new(Permitted_operands_0f, "8d", 0x10);
510 put_new(Permitted_operands_0f, "8e", 0x10);
511 put_new(Permitted_operands_0f, "8f", 0x10);
512
513
514
515
516 put_new(Permitted_operands_0f, "af", 0x01);
517
518 :(code)
519 void check_operands_0f(const line& inst, const word& op) {
520 uint8_t expected_bitvector = get(Permitted_operands_0f, op.data);
521 if (HAS(expected_bitvector, MODRM))
522 check_operands_modrm(inst, op);
523 compare_bitvector_0f(inst, CLEAR(expected_bitvector, MODRM), op);
524 }
525
526 void compare_bitvector_0f(const line& inst, uint8_t expected, const word& op) {
527 if (all_hex_bytes(inst) && has_operands(inst)) return;
528 uint8_t bitvector = compute_operand_bitvector(inst);
529 if (trace_contains_errors()) return;
530 if (bitvector == expected) return;
531 for (int i = 0; i < NUM_OPERAND_TYPES; ++i, bitvector >>= 1, expected >>= 1) {
532
533 if ((bitvector & 0x1) == (expected & 0x1)) continue;
534 const string& optype = Operand_type_name.at(i);
535 if ((bitvector & 0x1) > (expected & 0x1))
536 raise << "'" << to_string(inst) << "'" << maybe_name_0f(op) << ": unexpected " << optype << " operand\n" << end();
537 else
538 raise << "'" << to_string(inst) << "'" << maybe_name_0f(op) << ": missing " << optype << " operand\n" << end();
539
540 }
541
542 }
543
544 string maybe_name_0f(const word& op) {
545 if (!is_hex_byte(op)) return "";
546 if (!contains_key(Name_0f, op.data)) return "";
547
548 const string& s = get(Name_0f, op.data);
549 return " ("+s.substr(0, s.find(" ("))+')';
550 }
551
552 string tolower(const char* s) {
553 ostringstream out;
554 for (; *s; ++s)
555 out << static_cast<char>(tolower(*s));
556 return out.str();
557 }
558
559
560
561
562
563 :(before "End Includes")
564