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7
8#ifdef __KERNEL__
9#include <linux/string.h>
10#else
11#include <string.h>
12#endif
13#include "../include/asm/inat.h"
14#include "../include/asm/insn.h"
15
16#include "../include/asm/emulate_prefix.h"
17
18
19#define validate_next(t, insn, n) \
20 ((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
21
22#define __get_next(t, insn) \
23 ({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
24
25#define __peek_nbyte_next(t, insn, n) \
26 ({ t r = *(t*)((insn)->next_byte + n); r; })
27
28#define get_next(t, insn) \
29 ({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); })
30
31#define peek_nbyte_next(t, insn, n) \
32 ({ if (unlikely(!validate_next(t, insn, n))) goto err_out; __peek_nbyte_next(t, insn, n); })
33
34#define peek_next(t, insn) peek_nbyte_next(t, insn, 0)
35
36
37
38
39
40
41
42void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
43{
44
45
46
47
48 if (buf_len > MAX_INSN_SIZE)
49 buf_len = MAX_INSN_SIZE;
50
51 memset(insn, 0, sizeof(*insn));
52 insn->kaddr = kaddr;
53 insn->end_kaddr = kaddr + buf_len;
54 insn->next_byte = kaddr;
55 insn->x86_64 = x86_64 ? 1 : 0;
56 insn->opnd_bytes = 4;
57 if (x86_64)
58 insn->addr_bytes = 8;
59 else
60 insn->addr_bytes = 4;
61}
62
63static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
64static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
65
66static int __insn_get_emulate_prefix(struct insn *insn,
67 const insn_byte_t *prefix, size_t len)
68{
69 size_t i;
70
71 for (i = 0; i < len; i++) {
72 if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
73 goto err_out;
74 }
75
76 insn->emulate_prefix_size = len;
77 insn->next_byte += len;
78
79 return 1;
80
81err_out:
82 return 0;
83}
84
85static void insn_get_emulate_prefix(struct insn *insn)
86{
87 if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
88 return;
89
90 __insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
91}
92
93
94
95
96
97
98
99
100
101void insn_get_prefixes(struct insn *insn)
102{
103 struct insn_field *prefixes = &insn->prefixes;
104 insn_attr_t attr;
105 insn_byte_t b, lb;
106 int i, nb;
107
108 if (prefixes->got)
109 return;
110
111 insn_get_emulate_prefix(insn);
112
113 nb = 0;
114 lb = 0;
115 b = peek_next(insn_byte_t, insn);
116 attr = inat_get_opcode_attribute(b);
117 while (inat_is_legacy_prefix(attr)) {
118
119 for (i = 0; i < nb; i++)
120 if (prefixes->bytes[i] == b)
121 goto found;
122 if (nb == 4)
123
124 break;
125 prefixes->bytes[nb++] = b;
126 if (inat_is_address_size_prefix(attr)) {
127
128 if (insn->x86_64)
129 insn->addr_bytes ^= 12;
130 else
131 insn->addr_bytes ^= 6;
132 } else if (inat_is_operand_size_prefix(attr)) {
133
134 insn->opnd_bytes ^= 6;
135 }
136found:
137 prefixes->nbytes++;
138 insn->next_byte++;
139 lb = b;
140 b = peek_next(insn_byte_t, insn);
141 attr = inat_get_opcode_attribute(b);
142 }
143
144 if (lb && lb != insn->prefixes.bytes[3]) {
145 if (unlikely(insn->prefixes.bytes[3])) {
146
147 b = insn->prefixes.bytes[3];
148 for (i = 0; i < nb; i++)
149 if (prefixes->bytes[i] == lb)
150 prefixes->bytes[i] = b;
151 }
152 insn->prefixes.bytes[3] = lb;
153 }
154
155
156 if (insn->x86_64) {
157 b = peek_next(insn_byte_t, insn);
158 attr = inat_get_opcode_attribute(b);
159 if (inat_is_rex_prefix(attr)) {
160 insn->rex_prefix.value = b;
161 insn->rex_prefix.nbytes = 1;
162 insn->next_byte++;
163 if (X86_REX_W(b))
164
165 insn->opnd_bytes = 8;
166 }
167 }
168 insn->rex_prefix.got = 1;
169
170
171 b = peek_next(insn_byte_t, insn);
172 attr = inat_get_opcode_attribute(b);
173 if (inat_is_vex_prefix(attr)) {
174 insn_byte_t b2 = peek_nbyte_next(insn_byte_t, insn, 1);
175 if (!insn->x86_64) {
176
177
178
179
180
181 if (X86_MODRM_MOD(b2) != 3)
182 goto vex_end;
183 }
184 insn->vex_prefix.bytes[0] = b;
185 insn->vex_prefix.bytes[1] = b2;
186 if (inat_is_evex_prefix(attr)) {
187 b2 = peek_nbyte_next(insn_byte_t, insn, 2);
188 insn->vex_prefix.bytes[2] = b2;
189 b2 = peek_nbyte_next(insn_byte_t, insn, 3);
190 insn->vex_prefix.bytes[3] = b2;
191 insn->vex_prefix.nbytes = 4;
192 insn->next_byte += 4;
193 if (insn->x86_64 && X86_VEX_W(b2))
194
195 insn->opnd_bytes = 8;
196 } else if (inat_is_vex3_prefix(attr)) {
197 b2 = peek_nbyte_next(insn_byte_t, insn, 2);
198 insn->vex_prefix.bytes[2] = b2;
199 insn->vex_prefix.nbytes = 3;
200 insn->next_byte += 3;
201 if (insn->x86_64 && X86_VEX_W(b2))
202
203 insn->opnd_bytes = 8;
204 } else {
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206
207
208
209
210 insn->vex_prefix.bytes[2] = b2 & 0x7f;
211 insn->vex_prefix.nbytes = 2;
212 insn->next_byte += 2;
213 }
214 }
215vex_end:
216 insn->vex_prefix.got = 1;
217
218 prefixes->got = 1;
219
220err_out:
221 return;
222}
223
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227
228
229
230
231
232
233
234void insn_get_opcode(struct insn *insn)
235{
236 struct insn_field *opcode = &insn->opcode;
237 insn_byte_t op;
238 int pfx_id;
239 if (opcode->got)
240 return;
241 if (!insn->prefixes.got)
242 insn_get_prefixes(insn);
243
244
245 op = get_next(insn_byte_t, insn);
246 opcode->bytes[0] = op;
247 opcode->nbytes = 1;
248
249
250 if (insn_is_avx(insn)) {
251 insn_byte_t m, p;
252 m = insn_vex_m_bits(insn);
253 p = insn_vex_p_bits(insn);
254 insn->attr = inat_get_avx_attribute(op, m, p);
255 if ((inat_must_evex(insn->attr) && !insn_is_evex(insn)) ||
256 (!inat_accept_vex(insn->attr) &&
257 !inat_is_group(insn->attr)))
258 insn->attr = 0;
259 goto end;
260 }
261
262 insn->attr = inat_get_opcode_attribute(op);
263 while (inat_is_escape(insn->attr)) {
264
265 op = get_next(insn_byte_t, insn);
266 opcode->bytes[opcode->nbytes++] = op;
267 pfx_id = insn_last_prefix_id(insn);
268 insn->attr = inat_get_escape_attribute(op, pfx_id, insn->attr);
269 }
270 if (inat_must_vex(insn->attr))
271 insn->attr = 0;
272end:
273 opcode->got = 1;
274
275err_out:
276 return;
277}
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284
285
286
287void insn_get_modrm(struct insn *insn)
288{
289 struct insn_field *modrm = &insn->modrm;
290 insn_byte_t pfx_id, mod;
291 if (modrm->got)
292 return;
293 if (!insn->opcode.got)
294 insn_get_opcode(insn);
295
296 if (inat_has_modrm(insn->attr)) {
297 mod = get_next(insn_byte_t, insn);
298 modrm->value = mod;
299 modrm->nbytes = 1;
300 if (inat_is_group(insn->attr)) {
301 pfx_id = insn_last_prefix_id(insn);
302 insn->attr = inat_get_group_attribute(mod, pfx_id,
303 insn->attr);
304 if (insn_is_avx(insn) && !inat_accept_vex(insn->attr))
305 insn->attr = 0;
306 }
307 }
308
309 if (insn->x86_64 && inat_is_force64(insn->attr))
310 insn->opnd_bytes = 8;
311 modrm->got = 1;
312
313err_out:
314 return;
315}
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322
323
324
325int insn_rip_relative(struct insn *insn)
326{
327 struct insn_field *modrm = &insn->modrm;
328
329 if (!insn->x86_64)
330 return 0;
331 if (!modrm->got)
332 insn_get_modrm(insn);
333
334
335
336
337 return (modrm->nbytes && (modrm->value & 0xc7) == 0x5);
338}
339
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344
345
346
347void insn_get_sib(struct insn *insn)
348{
349 insn_byte_t modrm;
350
351 if (insn->sib.got)
352 return;
353 if (!insn->modrm.got)
354 insn_get_modrm(insn);
355 if (insn->modrm.nbytes) {
356 modrm = (insn_byte_t)insn->modrm.value;
357 if (insn->addr_bytes != 2 &&
358 X86_MODRM_MOD(modrm) != 3 && X86_MODRM_RM(modrm) == 4) {
359 insn->sib.value = get_next(insn_byte_t, insn);
360 insn->sib.nbytes = 1;
361 }
362 }
363 insn->sib.got = 1;
364
365err_out:
366 return;
367}
368
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375
376
377
378void insn_get_displacement(struct insn *insn)
379{
380 insn_byte_t mod, rm, base;
381
382 if (insn->displacement.got)
383 return;
384 if (!insn->sib.got)
385 insn_get_sib(insn);
386 if (insn->modrm.nbytes) {
387
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403
404 mod = X86_MODRM_MOD(insn->modrm.value);
405 rm = X86_MODRM_RM(insn->modrm.value);
406 base = X86_SIB_BASE(insn->sib.value);
407 if (mod == 3)
408 goto out;
409 if (mod == 1) {
410 insn->displacement.value = get_next(signed char, insn);
411 insn->displacement.nbytes = 1;
412 } else if (insn->addr_bytes == 2) {
413 if ((mod == 0 && rm == 6) || mod == 2) {
414 insn->displacement.value =
415 get_next(short, insn);
416 insn->displacement.nbytes = 2;
417 }
418 } else {
419 if ((mod == 0 && rm == 5) || mod == 2 ||
420 (mod == 0 && base == 5)) {
421 insn->displacement.value = get_next(int, insn);
422 insn->displacement.nbytes = 4;
423 }
424 }
425 }
426out:
427 insn->displacement.got = 1;
428
429err_out:
430 return;
431}
432
433
434static int __get_moffset(struct insn *insn)
435{
436 switch (insn->addr_bytes) {
437 case 2:
438 insn->moffset1.value = get_next(short, insn);
439 insn->moffset1.nbytes = 2;
440 break;
441 case 4:
442 insn->moffset1.value = get_next(int, insn);
443 insn->moffset1.nbytes = 4;
444 break;
445 case 8:
446 insn->moffset1.value = get_next(int, insn);
447 insn->moffset1.nbytes = 4;
448 insn->moffset2.value = get_next(int, insn);
449 insn->moffset2.nbytes = 4;
450 break;
451 default:
452 goto err_out;
453 }
454 insn->moffset1.got = insn->moffset2.got = 1;
455
456 return 1;
457
458err_out:
459 return 0;
460}
461
462
463static int __get_immv32(struct insn *insn)
464{
465 switch (insn->opnd_bytes) {
466 case 2:
467 insn->immediate.value = get_next(short, insn);
468 insn->immediate.nbytes = 2;
469 break;
470 case 4:
471 case 8:
472 insn->immediate.value = get_next(int, insn);
473 insn->immediate.nbytes = 4;
474 break;
475 default:
476 goto err_out;
477 }
478
479 return 1;
480
481err_out:
482 return 0;
483}
484
485
486static int __get_immv(struct insn *insn)
487{
488 switch (insn->opnd_bytes) {
489 case 2:
490 insn->immediate1.value = get_next(short, insn);
491 insn->immediate1.nbytes = 2;
492 break;
493 case 4:
494 insn->immediate1.value = get_next(int, insn);
495 insn->immediate1.nbytes = 4;
496 break;
497 case 8:
498 insn->immediate1.value = get_next(int, insn);
499 insn->immediate1.nbytes = 4;
500 insn->immediate2.value = get_next(int, insn);
501 insn->immediate2.nbytes = 4;
502 break;
503 default:
504 goto err_out;
505 }
506 insn->immediate1.got = insn->immediate2.got = 1;
507
508 return 1;
509err_out:
510 return 0;
511}
512
513
514static int __get_immptr(struct insn *insn)
515{
516 switch (insn->opnd_bytes) {
517 case 2:
518 insn->immediate1.value = get_next(short, insn);
519 insn->immediate1.nbytes = 2;
520 break;
521 case 4:
522 insn->immediate1.value = get_next(int, insn);
523 insn->immediate1.nbytes = 4;
524 break;
525 case 8:
526
527 return 0;
528 default:
529 goto err_out;
530 }
531 insn->immediate2.value = get_next(unsigned short, insn);
532 insn->immediate2.nbytes = 2;
533 insn->immediate1.got = insn->immediate2.got = 1;
534
535 return 1;
536err_out:
537 return 0;
538}
539
540
541
542
543
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546
547
548
549void insn_get_immediate(struct insn *insn)
550{
551 if (insn->immediate.got)
552 return;
553 if (!insn->displacement.got)
554 insn_get_displacement(insn);
555
556 if (inat_has_moffset(insn->attr)) {
557 if (!__get_moffset(insn))
558 goto err_out;
559 goto done;
560 }
561
562 if (!inat_has_immediate(insn->attr))
563
564 goto done;
565
566 switch (inat_immediate_size(insn->attr)) {
567 case INAT_IMM_BYTE:
568 insn->immediate.value = get_next(signed char, insn);
569 insn->immediate.nbytes = 1;
570 break;
571 case INAT_IMM_WORD:
572 insn->immediate.value = get_next(short, insn);
573 insn->immediate.nbytes = 2;
574 break;
575 case INAT_IMM_DWORD:
576 insn->immediate.value = get_next(int, insn);
577 insn->immediate.nbytes = 4;
578 break;
579 case INAT_IMM_QWORD:
580 insn->immediate1.value = get_next(int, insn);
581 insn->immediate1.nbytes = 4;
582 insn->immediate2.value = get_next(int, insn);
583 insn->immediate2.nbytes = 4;
584 break;
585 case INAT_IMM_PTR:
586 if (!__get_immptr(insn))
587 goto err_out;
588 break;
589 case INAT_IMM_VWORD32:
590 if (!__get_immv32(insn))
591 goto err_out;
592 break;
593 case INAT_IMM_VWORD:
594 if (!__get_immv(insn))
595 goto err_out;
596 break;
597 default:
598
599 goto err_out;
600 }
601 if (inat_has_second_immediate(insn->attr)) {
602 insn->immediate2.value = get_next(signed char, insn);
603 insn->immediate2.nbytes = 1;
604 }
605done:
606 insn->immediate.got = 1;
607
608err_out:
609 return;
610}
611
612
613
614
615
616
617
618
619void insn_get_length(struct insn *insn)
620{
621 if (insn->length)
622 return;
623 if (!insn->immediate.got)
624 insn_get_immediate(insn);
625 insn->length = (unsigned char)((unsigned long)insn->next_byte
626 - (unsigned long)insn->kaddr);
627}
628