1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //
8 // Parses DWARF CFIs (FDEs and CIEs).
9 //
10 //===----------------------------------------------------------------------===//
11
12 #ifndef __DWARF_PARSER_HPP__
13 #define __DWARF_PARSER_HPP__
14
15 #include <inttypes.h>
16 #include <stdint.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19
20 #include "libunwind.h"
21 #include "dwarf2.h"
22 #include "Registers.hpp"
23
24 #include "config.h"
25
26 namespace libunwind {
27
28 /// CFI_Parser does basic parsing of a CFI (Call Frame Information) records.
29 /// See DWARF Spec for details:
30 /// http://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
31 ///
32 template <typename A>
33 class CFI_Parser {
34 public:
35 typedef typename A::pint_t pint_t;
36
37 /// Information encoded in a CIE (Common Information Entry)
38 struct CIE_Info {
39 pint_t cieStart;
40 pint_t cieLength;
41 pint_t cieInstructions;
42 uint8_t pointerEncoding;
43 uint8_t lsdaEncoding;
44 uint8_t personalityEncoding;
45 uint8_t personalityOffsetInCIE;
46 pint_t personality;
47 uint32_t codeAlignFactor;
48 int dataAlignFactor;
49 bool isSignalFrame;
50 bool fdesHaveAugmentationData;
51 uint8_t returnAddressRegister;
52 #if defined(_LIBUNWIND_TARGET_AARCH64)
53 bool addressesSignedWithBKey;
54 bool mteTaggedFrame;
55 #endif
56 };
57
58 /// Information about an FDE (Frame Description Entry)
59 struct FDE_Info {
60 pint_t fdeStart;
61 pint_t fdeLength;
62 pint_t fdeInstructions;
63 pint_t pcStart;
64 pint_t pcEnd;
65 pint_t lsda;
66 };
67
68 enum {
69 kMaxRegisterNumber = _LIBUNWIND_HIGHEST_DWARF_REGISTER
70 };
71 enum RegisterSavedWhere {
72 kRegisterUnused,
73 kRegisterUndefined,
74 kRegisterInCFA,
75 kRegisterInCFADecrypt, // sparc64 specific
76 kRegisterOffsetFromCFA,
77 kRegisterInRegister,
78 kRegisterAtExpression,
79 kRegisterIsExpression
80 };
81 struct RegisterLocation {
82 RegisterSavedWhere location;
83 bool initialStateSaved;
84 int64_t value;
85 };
86 /// Information about a frame layout and registers saved determined
87 /// by "running" the DWARF FDE "instructions"
88 struct PrologInfo {
89 uint32_t cfaRegister;
90 int32_t cfaRegisterOffset; // CFA = (cfaRegister)+cfaRegisterOffset
91 int64_t cfaExpression; // CFA = expression
92 uint32_t spExtraArgSize;
93 RegisterLocation savedRegisters[kMaxRegisterNumber + 1];
94 enum class InitializeTime { kLazy, kNormal };
95
96 // When saving registers, this data structure is lazily initialized.
PrologInfolibunwind::CFI_Parser::PrologInfo97 PrologInfo(InitializeTime IT = InitializeTime::kNormal) {
98 if (IT == InitializeTime::kNormal)
99 memset(this, 0, sizeof(*this));
100 }
checkSaveRegisterlibunwind::CFI_Parser::PrologInfo101 void checkSaveRegister(uint64_t reg, PrologInfo &initialState) {
102 if (!savedRegisters[reg].initialStateSaved) {
103 initialState.savedRegisters[reg] = savedRegisters[reg];
104 savedRegisters[reg].initialStateSaved = true;
105 }
106 }
setRegisterlibunwind::CFI_Parser::PrologInfo107 void setRegister(uint64_t reg, RegisterSavedWhere newLocation,
108 int64_t newValue, PrologInfo &initialState) {
109 checkSaveRegister(reg, initialState);
110 savedRegisters[reg].location = newLocation;
111 savedRegisters[reg].value = newValue;
112 }
setRegisterLocationlibunwind::CFI_Parser::PrologInfo113 void setRegisterLocation(uint64_t reg, RegisterSavedWhere newLocation,
114 PrologInfo &initialState) {
115 checkSaveRegister(reg, initialState);
116 savedRegisters[reg].location = newLocation;
117 }
setRegisterValuelibunwind::CFI_Parser::PrologInfo118 void setRegisterValue(uint64_t reg, int64_t newValue,
119 PrologInfo &initialState) {
120 checkSaveRegister(reg, initialState);
121 savedRegisters[reg].value = newValue;
122 }
restoreRegisterToInitialStatelibunwind::CFI_Parser::PrologInfo123 void restoreRegisterToInitialState(uint64_t reg, PrologInfo &initialState) {
124 if (savedRegisters[reg].initialStateSaved)
125 savedRegisters[reg] = initialState.savedRegisters[reg];
126 // else the register still holds its initial state
127 }
128 };
129
130 struct PrologInfoStackEntry {
PrologInfoStackEntrylibunwind::CFI_Parser::PrologInfoStackEntry131 PrologInfoStackEntry(PrologInfoStackEntry *n, const PrologInfo &i)
132 : next(n), info(i) {}
133 PrologInfoStackEntry *next;
134 PrologInfo info;
135 };
136
137 struct RememberStack {
138 PrologInfoStackEntry *entry;
RememberStacklibunwind::CFI_Parser::RememberStack139 RememberStack() : entry(nullptr) {}
~RememberStacklibunwind::CFI_Parser::RememberStack140 ~RememberStack() {
141 #if defined(_LIBUNWIND_REMEMBER_CLEANUP_NEEDED)
142 // Clean up rememberStack. Even in the case where every
143 // DW_CFA_remember_state is paired with a DW_CFA_restore_state,
144 // parseInstructions can skip restore opcodes if it reaches the target PC
145 // and stops interpreting, so we have to make sure we don't leak memory.
146 while (entry) {
147 PrologInfoStackEntry *next = entry->next;
148 _LIBUNWIND_REMEMBER_FREE(entry);
149 entry = next;
150 }
151 #endif
152 }
153 };
154
155 static bool findFDE(A &addressSpace, pint_t pc, pint_t ehSectionStart,
156 size_t sectionLength, pint_t fdeHint, FDE_Info *fdeInfo,
157 CIE_Info *cieInfo);
158 static const char *decodeFDE(A &addressSpace, pint_t fdeStart,
159 FDE_Info *fdeInfo, CIE_Info *cieInfo,
160 bool useCIEInfo = false);
161 static bool parseFDEInstructions(A &addressSpace, const FDE_Info &fdeInfo,
162 const CIE_Info &cieInfo, pint_t upToPC,
163 int arch, PrologInfo *results);
164
165 static const char *parseCIE(A &addressSpace, pint_t cie, CIE_Info *cieInfo);
166 };
167
168 /// Parse a FDE into a CIE_Info and an FDE_Info. If useCIEInfo is
169 /// true, treat cieInfo as already-parsed CIE_Info (whose start offset
170 /// must match the one specified by the FDE) rather than parsing the
171 /// one indicated within the FDE.
172 template <typename A>
decodeFDE(A & addressSpace,pint_t fdeStart,FDE_Info * fdeInfo,CIE_Info * cieInfo,bool useCIEInfo)173 const char *CFI_Parser<A>::decodeFDE(A &addressSpace, pint_t fdeStart,
174 FDE_Info *fdeInfo, CIE_Info *cieInfo,
175 bool useCIEInfo) {
176 pint_t p = fdeStart;
177 pint_t cfiLength = (pint_t)addressSpace.get32(p);
178 p += 4;
179 if (cfiLength == 0xffffffff) {
180 // 0xffffffff means length is really next 8 bytes
181 cfiLength = (pint_t)addressSpace.get64(p);
182 p += 8;
183 }
184 if (cfiLength == 0)
185 return "FDE has zero length"; // zero terminator
186 uint32_t ciePointer = addressSpace.get32(p);
187 if (ciePointer == 0)
188 return "FDE is really a CIE"; // this is a CIE not an FDE
189 pint_t nextCFI = p + cfiLength;
190 pint_t cieStart = p - ciePointer;
191 if (useCIEInfo) {
192 if (cieInfo->cieStart != cieStart)
193 return "CIE start does not match";
194 } else {
195 const char *err = parseCIE(addressSpace, cieStart, cieInfo);
196 if (err != NULL)
197 return err;
198 }
199 p += 4;
200 // Parse pc begin and range.
201 pint_t pcStart =
202 addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding);
203 pint_t pcRange =
204 addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding & 0x0F);
205 // Parse rest of info.
206 fdeInfo->lsda = 0;
207 // Check for augmentation length.
208 if (cieInfo->fdesHaveAugmentationData) {
209 pint_t augLen = (pint_t)addressSpace.getULEB128(p, nextCFI);
210 pint_t endOfAug = p + augLen;
211 if (cieInfo->lsdaEncoding != DW_EH_PE_omit) {
212 // Peek at value (without indirection). Zero means no LSDA.
213 pint_t lsdaStart = p;
214 if (addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding & 0x0F) !=
215 0) {
216 // Reset pointer and re-parse LSDA address.
217 p = lsdaStart;
218 fdeInfo->lsda =
219 addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding);
220 }
221 }
222 p = endOfAug;
223 }
224 fdeInfo->fdeStart = fdeStart;
225 fdeInfo->fdeLength = nextCFI - fdeStart;
226 fdeInfo->fdeInstructions = p;
227 fdeInfo->pcStart = pcStart;
228 fdeInfo->pcEnd = pcStart + pcRange;
229 return NULL; // success
230 }
231
232 /// Scan an eh_frame section to find an FDE for a pc
233 template <typename A>
findFDE(A & addressSpace,pint_t pc,pint_t ehSectionStart,size_t sectionLength,pint_t fdeHint,FDE_Info * fdeInfo,CIE_Info * cieInfo)234 bool CFI_Parser<A>::findFDE(A &addressSpace, pint_t pc, pint_t ehSectionStart,
235 size_t sectionLength, pint_t fdeHint,
236 FDE_Info *fdeInfo, CIE_Info *cieInfo) {
237 //fprintf(stderr, "findFDE(0x%llX)\n", (long long)pc);
238 pint_t p = (fdeHint != 0) ? fdeHint : ehSectionStart;
239 const pint_t ehSectionEnd = (sectionLength == SIZE_MAX)
240 ? static_cast<pint_t>(-1)
241 : (ehSectionStart + sectionLength);
242 while (p < ehSectionEnd) {
243 pint_t currentCFI = p;
244 //fprintf(stderr, "findFDE() CFI at 0x%llX\n", (long long)p);
245 pint_t cfiLength = addressSpace.get32(p);
246 p += 4;
247 if (cfiLength == 0xffffffff) {
248 // 0xffffffff means length is really next 8 bytes
249 cfiLength = (pint_t)addressSpace.get64(p);
250 p += 8;
251 }
252 if (cfiLength == 0)
253 return false; // zero terminator
254 uint32_t id = addressSpace.get32(p);
255 if (id == 0) {
256 // Skip over CIEs.
257 p += cfiLength;
258 } else {
259 // Process FDE to see if it covers pc.
260 pint_t nextCFI = p + cfiLength;
261 uint32_t ciePointer = addressSpace.get32(p);
262 pint_t cieStart = p - ciePointer;
263 // Validate pointer to CIE is within section.
264 if ((ehSectionStart <= cieStart) && (cieStart < ehSectionEnd)) {
265 if (parseCIE(addressSpace, cieStart, cieInfo) == NULL) {
266 p += 4;
267 // Parse pc begin and range.
268 pint_t pcStart =
269 addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding);
270 pint_t pcRange = addressSpace.getEncodedP(
271 p, nextCFI, cieInfo->pointerEncoding & 0x0F);
272 // Test if pc is within the function this FDE covers.
273 if ((pcStart < pc) && (pc <= pcStart + pcRange)) {
274 // parse rest of info
275 fdeInfo->lsda = 0;
276 // check for augmentation length
277 if (cieInfo->fdesHaveAugmentationData) {
278 pint_t augLen = (pint_t)addressSpace.getULEB128(p, nextCFI);
279 pint_t endOfAug = p + augLen;
280 if (cieInfo->lsdaEncoding != DW_EH_PE_omit) {
281 // Peek at value (without indirection). Zero means no LSDA.
282 pint_t lsdaStart = p;
283 if (addressSpace.getEncodedP(
284 p, nextCFI, cieInfo->lsdaEncoding & 0x0F) != 0) {
285 // Reset pointer and re-parse LSDA address.
286 p = lsdaStart;
287 fdeInfo->lsda = addressSpace
288 .getEncodedP(p, nextCFI, cieInfo->lsdaEncoding);
289 }
290 }
291 p = endOfAug;
292 }
293 fdeInfo->fdeStart = currentCFI;
294 fdeInfo->fdeLength = nextCFI - currentCFI;
295 fdeInfo->fdeInstructions = p;
296 fdeInfo->pcStart = pcStart;
297 fdeInfo->pcEnd = pcStart + pcRange;
298 return true;
299 } else {
300 // pc is not in begin/range, skip this FDE
301 }
302 } else {
303 // Malformed CIE, now augmentation describing pc range encoding.
304 }
305 } else {
306 // malformed FDE. CIE is bad
307 }
308 p = nextCFI;
309 }
310 }
311 return false;
312 }
313
314 /// Extract info from a CIE
315 template <typename A>
parseCIE(A & addressSpace,pint_t cie,CIE_Info * cieInfo)316 const char *CFI_Parser<A>::parseCIE(A &addressSpace, pint_t cie,
317 CIE_Info *cieInfo) {
318 cieInfo->pointerEncoding = 0;
319 cieInfo->lsdaEncoding = DW_EH_PE_omit;
320 cieInfo->personalityEncoding = 0;
321 cieInfo->personalityOffsetInCIE = 0;
322 cieInfo->personality = 0;
323 cieInfo->codeAlignFactor = 0;
324 cieInfo->dataAlignFactor = 0;
325 cieInfo->isSignalFrame = false;
326 cieInfo->fdesHaveAugmentationData = false;
327 #if defined(_LIBUNWIND_TARGET_AARCH64)
328 cieInfo->addressesSignedWithBKey = false;
329 cieInfo->mteTaggedFrame = false;
330 #endif
331 cieInfo->cieStart = cie;
332 pint_t p = cie;
333 pint_t cieLength = (pint_t)addressSpace.get32(p);
334 p += 4;
335 pint_t cieContentEnd = p + cieLength;
336 if (cieLength == 0xffffffff) {
337 // 0xffffffff means length is really next 8 bytes
338 cieLength = (pint_t)addressSpace.get64(p);
339 p += 8;
340 cieContentEnd = p + cieLength;
341 }
342 if (cieLength == 0)
343 return NULL;
344 // CIE ID is always 0
345 if (addressSpace.get32(p) != 0)
346 return "CIE ID is not zero";
347 p += 4;
348 // Version is always 1 or 3
349 uint8_t version = addressSpace.get8(p);
350 if ((version != 1) && (version != 3))
351 return "CIE version is not 1 or 3";
352 ++p;
353 // save start of augmentation string and find end
354 pint_t strStart = p;
355 while (addressSpace.get8(p) != 0)
356 ++p;
357 ++p;
358 // parse code alignment factor
359 cieInfo->codeAlignFactor = (uint32_t)addressSpace.getULEB128(p, cieContentEnd);
360 // parse data alignment factor
361 cieInfo->dataAlignFactor = (int)addressSpace.getSLEB128(p, cieContentEnd);
362 // parse return address register
363 uint64_t raReg = (version == 1) ? addressSpace.get8(p++)
364 : addressSpace.getULEB128(p, cieContentEnd);
365 assert(raReg < 255 && "return address register too large");
366 cieInfo->returnAddressRegister = (uint8_t)raReg;
367 // parse augmentation data based on augmentation string
368 const char *result = NULL;
369 if (addressSpace.get8(strStart) == 'z') {
370 // parse augmentation data length
371 addressSpace.getULEB128(p, cieContentEnd);
372 for (pint_t s = strStart; addressSpace.get8(s) != '\0'; ++s) {
373 switch (addressSpace.get8(s)) {
374 case 'z':
375 cieInfo->fdesHaveAugmentationData = true;
376 break;
377 case 'P':
378 cieInfo->personalityEncoding = addressSpace.get8(p);
379 ++p;
380 cieInfo->personalityOffsetInCIE = (uint8_t)(p - cie);
381 cieInfo->personality = addressSpace
382 .getEncodedP(p, cieContentEnd, cieInfo->personalityEncoding);
383 break;
384 case 'L':
385 cieInfo->lsdaEncoding = addressSpace.get8(p);
386 ++p;
387 break;
388 case 'R':
389 cieInfo->pointerEncoding = addressSpace.get8(p);
390 ++p;
391 break;
392 case 'S':
393 cieInfo->isSignalFrame = true;
394 break;
395 #if defined(_LIBUNWIND_TARGET_AARCH64)
396 case 'B':
397 cieInfo->addressesSignedWithBKey = true;
398 break;
399 case 'G':
400 cieInfo->mteTaggedFrame = true;
401 break;
402 #endif
403 default:
404 // ignore unknown letters
405 break;
406 }
407 }
408 }
409 cieInfo->cieLength = cieContentEnd - cieInfo->cieStart;
410 cieInfo->cieInstructions = p;
411 return result;
412 }
413
414
415 /// "run" the DWARF instructions and create the abstract PrologInfo for an FDE
416 template <typename A>
parseFDEInstructions(A & addressSpace,const FDE_Info & fdeInfo,const CIE_Info & cieInfo,pint_t upToPC,int arch,PrologInfo * results)417 bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
418 const FDE_Info &fdeInfo,
419 const CIE_Info &cieInfo, pint_t upToPC,
420 int arch, PrologInfo *results) {
421 // Alloca is used for the allocation of the rememberStack entries. It removes
422 // the dependency on new/malloc but the below for loop can not be refactored
423 // into functions. Entry could be saved during the processing of a CIE and
424 // restored by an FDE.
425 RememberStack rememberStack;
426
427 struct ParseInfo {
428 pint_t instructions;
429 pint_t instructionsEnd;
430 pint_t pcoffset;
431 };
432
433 ParseInfo parseInfoArray[] = {
434 {cieInfo.cieInstructions, cieInfo.cieStart + cieInfo.cieLength,
435 (pint_t)(-1)},
436 {fdeInfo.fdeInstructions, fdeInfo.fdeStart + fdeInfo.fdeLength,
437 upToPC - fdeInfo.pcStart}};
438
439 for (const auto &info : parseInfoArray) {
440 pint_t p = info.instructions;
441 pint_t instructionsEnd = info.instructionsEnd;
442 pint_t pcoffset = info.pcoffset;
443 pint_t codeOffset = 0;
444
445 // initialState initialized as registers in results are modified. Use
446 // PrologInfo accessor functions to avoid reading uninitialized data.
447 PrologInfo initialState(PrologInfo::InitializeTime::kLazy);
448
449 _LIBUNWIND_TRACE_DWARF("parseFDEInstructions(instructions=0x%0" PRIx64
450 ")\n",
451 static_cast<uint64_t>(instructionsEnd));
452
453 // see DWARF Spec, section 6.4.2 for details on unwind opcodes
454 while ((p < instructionsEnd) && (codeOffset < pcoffset)) {
455 uint64_t reg;
456 uint64_t reg2;
457 int64_t offset;
458 uint64_t length;
459 uint8_t opcode = addressSpace.get8(p);
460 uint8_t operand;
461
462 ++p;
463 switch (opcode) {
464 case DW_CFA_nop:
465 _LIBUNWIND_TRACE_DWARF("DW_CFA_nop\n");
466 break;
467 case DW_CFA_set_loc:
468 codeOffset = addressSpace.getEncodedP(p, instructionsEnd,
469 cieInfo.pointerEncoding);
470 _LIBUNWIND_TRACE_DWARF("DW_CFA_set_loc\n");
471 break;
472 case DW_CFA_advance_loc1:
473 codeOffset += (addressSpace.get8(p) * cieInfo.codeAlignFactor);
474 p += 1;
475 _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc1: new offset=%" PRIu64 "\n",
476 static_cast<uint64_t>(codeOffset));
477 break;
478 case DW_CFA_advance_loc2:
479 codeOffset += (addressSpace.get16(p) * cieInfo.codeAlignFactor);
480 p += 2;
481 _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc2: new offset=%" PRIu64 "\n",
482 static_cast<uint64_t>(codeOffset));
483 break;
484 case DW_CFA_advance_loc4:
485 codeOffset += (addressSpace.get32(p) * cieInfo.codeAlignFactor);
486 p += 4;
487 _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc4: new offset=%" PRIu64 "\n",
488 static_cast<uint64_t>(codeOffset));
489 break;
490 case DW_CFA_offset_extended:
491 reg = addressSpace.getULEB128(p, instructionsEnd);
492 offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) *
493 cieInfo.dataAlignFactor;
494 if (reg > kMaxRegisterNumber) {
495 _LIBUNWIND_LOG0(
496 "malformed DW_CFA_offset_extended DWARF unwind, reg too big");
497 return false;
498 }
499 results->setRegister(reg, kRegisterInCFA, offset, initialState);
500 _LIBUNWIND_TRACE_DWARF("DW_CFA_offset_extended(reg=%" PRIu64 ", "
501 "offset=%" PRId64 ")\n",
502 reg, offset);
503 break;
504 case DW_CFA_restore_extended:
505 reg = addressSpace.getULEB128(p, instructionsEnd);
506 if (reg > kMaxRegisterNumber) {
507 _LIBUNWIND_LOG0(
508 "malformed DW_CFA_restore_extended DWARF unwind, reg too big");
509 return false;
510 }
511 results->restoreRegisterToInitialState(reg, initialState);
512 _LIBUNWIND_TRACE_DWARF("DW_CFA_restore_extended(reg=%" PRIu64 ")\n",
513 reg);
514 break;
515 case DW_CFA_undefined:
516 reg = addressSpace.getULEB128(p, instructionsEnd);
517 if (reg > kMaxRegisterNumber) {
518 _LIBUNWIND_LOG0(
519 "malformed DW_CFA_undefined DWARF unwind, reg too big");
520 return false;
521 }
522 results->setRegisterLocation(reg, kRegisterUndefined, initialState);
523 _LIBUNWIND_TRACE_DWARF("DW_CFA_undefined(reg=%" PRIu64 ")\n", reg);
524 break;
525 case DW_CFA_same_value:
526 reg = addressSpace.getULEB128(p, instructionsEnd);
527 if (reg > kMaxRegisterNumber) {
528 _LIBUNWIND_LOG0(
529 "malformed DW_CFA_same_value DWARF unwind, reg too big");
530 return false;
531 }
532 // <rdar://problem/8456377> DW_CFA_same_value unsupported
533 // "same value" means register was stored in frame, but its current
534 // value has not changed, so no need to restore from frame.
535 // We model this as if the register was never saved.
536 results->setRegisterLocation(reg, kRegisterUnused, initialState);
537 _LIBUNWIND_TRACE_DWARF("DW_CFA_same_value(reg=%" PRIu64 ")\n", reg);
538 break;
539 case DW_CFA_register:
540 reg = addressSpace.getULEB128(p, instructionsEnd);
541 reg2 = addressSpace.getULEB128(p, instructionsEnd);
542 if (reg > kMaxRegisterNumber) {
543 _LIBUNWIND_LOG0(
544 "malformed DW_CFA_register DWARF unwind, reg too big");
545 return false;
546 }
547 if (reg2 > kMaxRegisterNumber) {
548 _LIBUNWIND_LOG0(
549 "malformed DW_CFA_register DWARF unwind, reg2 too big");
550 return false;
551 }
552 results->setRegister(reg, kRegisterInRegister, (int64_t)reg2,
553 initialState);
554 _LIBUNWIND_TRACE_DWARF(
555 "DW_CFA_register(reg=%" PRIu64 ", reg2=%" PRIu64 ")\n", reg, reg2);
556 break;
557 case DW_CFA_remember_state: {
558 // Avoid operator new because that would be an upward dependency.
559 // Avoid malloc because it needs heap allocation.
560 PrologInfoStackEntry *entry =
561 (PrologInfoStackEntry *)_LIBUNWIND_REMEMBER_ALLOC(
562 sizeof(PrologInfoStackEntry));
563 if (entry != NULL) {
564 entry->next = rememberStack.entry;
565 entry->info = *results;
566 rememberStack.entry = entry;
567 } else {
568 return false;
569 }
570 _LIBUNWIND_TRACE_DWARF("DW_CFA_remember_state\n");
571 break;
572 }
573 case DW_CFA_restore_state:
574 if (rememberStack.entry != NULL) {
575 PrologInfoStackEntry *top = rememberStack.entry;
576 *results = top->info;
577 rememberStack.entry = top->next;
578 _LIBUNWIND_REMEMBER_FREE(top);
579 } else {
580 return false;
581 }
582 _LIBUNWIND_TRACE_DWARF("DW_CFA_restore_state\n");
583 break;
584 case DW_CFA_def_cfa:
585 reg = addressSpace.getULEB128(p, instructionsEnd);
586 offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd);
587 if (reg > kMaxRegisterNumber) {
588 _LIBUNWIND_LOG0("malformed DW_CFA_def_cfa DWARF unwind, reg too big");
589 return false;
590 }
591 results->cfaRegister = (uint32_t)reg;
592 results->cfaRegisterOffset = (int32_t)offset;
593 _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa(reg=%" PRIu64 ", offset=%" PRIu64
594 ")\n",
595 reg, offset);
596 break;
597 case DW_CFA_def_cfa_register:
598 reg = addressSpace.getULEB128(p, instructionsEnd);
599 if (reg > kMaxRegisterNumber) {
600 _LIBUNWIND_LOG0(
601 "malformed DW_CFA_def_cfa_register DWARF unwind, reg too big");
602 return false;
603 }
604 results->cfaRegister = (uint32_t)reg;
605 _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_register(%" PRIu64 ")\n", reg);
606 break;
607 case DW_CFA_def_cfa_offset:
608 results->cfaRegisterOffset =
609 (int32_t)addressSpace.getULEB128(p, instructionsEnd);
610 _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_offset(%d)\n",
611 results->cfaRegisterOffset);
612 break;
613 case DW_CFA_def_cfa_expression:
614 results->cfaRegister = 0;
615 results->cfaExpression = (int64_t)p;
616 length = addressSpace.getULEB128(p, instructionsEnd);
617 assert(length < static_cast<pint_t>(~0) && "pointer overflow");
618 p += static_cast<pint_t>(length);
619 _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_expression(expression=0x%" PRIx64
620 ", length=%" PRIu64 ")\n",
621 results->cfaExpression, length);
622 break;
623 case DW_CFA_expression:
624 reg = addressSpace.getULEB128(p, instructionsEnd);
625 if (reg > kMaxRegisterNumber) {
626 _LIBUNWIND_LOG0(
627 "malformed DW_CFA_expression DWARF unwind, reg too big");
628 return false;
629 }
630 results->setRegister(reg, kRegisterAtExpression, (int64_t)p,
631 initialState);
632 length = addressSpace.getULEB128(p, instructionsEnd);
633 assert(length < static_cast<pint_t>(~0) && "pointer overflow");
634 p += static_cast<pint_t>(length);
635 _LIBUNWIND_TRACE_DWARF("DW_CFA_expression(reg=%" PRIu64 ", "
636 "expression=0x%" PRIx64 ", "
637 "length=%" PRIu64 ")\n",
638 reg, results->savedRegisters[reg].value, length);
639 break;
640 case DW_CFA_offset_extended_sf:
641 reg = addressSpace.getULEB128(p, instructionsEnd);
642 if (reg > kMaxRegisterNumber) {
643 _LIBUNWIND_LOG0(
644 "malformed DW_CFA_offset_extended_sf DWARF unwind, reg too big");
645 return false;
646 }
647 offset = addressSpace.getSLEB128(p, instructionsEnd) *
648 cieInfo.dataAlignFactor;
649 results->setRegister(reg, kRegisterInCFA, offset, initialState);
650 _LIBUNWIND_TRACE_DWARF("DW_CFA_offset_extended_sf(reg=%" PRIu64 ", "
651 "offset=%" PRId64 ")\n",
652 reg, offset);
653 break;
654 case DW_CFA_def_cfa_sf:
655 reg = addressSpace.getULEB128(p, instructionsEnd);
656 offset = addressSpace.getSLEB128(p, instructionsEnd) *
657 cieInfo.dataAlignFactor;
658 if (reg > kMaxRegisterNumber) {
659 _LIBUNWIND_LOG0(
660 "malformed DW_CFA_def_cfa_sf DWARF unwind, reg too big");
661 return false;
662 }
663 results->cfaRegister = (uint32_t)reg;
664 results->cfaRegisterOffset = (int32_t)offset;
665 _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_sf(reg=%" PRIu64 ", "
666 "offset=%" PRId64 ")\n",
667 reg, offset);
668 break;
669 case DW_CFA_def_cfa_offset_sf:
670 results->cfaRegisterOffset =
671 (int32_t)(addressSpace.getSLEB128(p, instructionsEnd) *
672 cieInfo.dataAlignFactor);
673 _LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_offset_sf(%d)\n",
674 results->cfaRegisterOffset);
675 break;
676 case DW_CFA_val_offset:
677 reg = addressSpace.getULEB128(p, instructionsEnd);
678 if (reg > kMaxRegisterNumber) {
679 _LIBUNWIND_LOG(
680 "malformed DW_CFA_val_offset DWARF unwind, reg (%" PRIu64
681 ") out of range\n",
682 reg);
683 return false;
684 }
685 offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) *
686 cieInfo.dataAlignFactor;
687 results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState);
688 _LIBUNWIND_TRACE_DWARF("DW_CFA_val_offset(reg=%" PRIu64 ", "
689 "offset=%" PRId64 "\n",
690 reg, offset);
691 break;
692 case DW_CFA_val_offset_sf:
693 reg = addressSpace.getULEB128(p, instructionsEnd);
694 if (reg > kMaxRegisterNumber) {
695 _LIBUNWIND_LOG0(
696 "malformed DW_CFA_val_offset_sf DWARF unwind, reg too big");
697 return false;
698 }
699 offset = addressSpace.getSLEB128(p, instructionsEnd) *
700 cieInfo.dataAlignFactor;
701 results->setRegister(reg, kRegisterOffsetFromCFA, offset, initialState);
702 _LIBUNWIND_TRACE_DWARF("DW_CFA_val_offset_sf(reg=%" PRIu64 ", "
703 "offset=%" PRId64 "\n",
704 reg, offset);
705 break;
706 case DW_CFA_val_expression:
707 reg = addressSpace.getULEB128(p, instructionsEnd);
708 if (reg > kMaxRegisterNumber) {
709 _LIBUNWIND_LOG0(
710 "malformed DW_CFA_val_expression DWARF unwind, reg too big");
711 return false;
712 }
713 results->setRegister(reg, kRegisterIsExpression, (int64_t)p,
714 initialState);
715 length = addressSpace.getULEB128(p, instructionsEnd);
716 assert(length < static_cast<pint_t>(~0) && "pointer overflow");
717 p += static_cast<pint_t>(length);
718 _LIBUNWIND_TRACE_DWARF("DW_CFA_val_expression(reg=%" PRIu64 ", "
719 "expression=0x%" PRIx64 ", length=%" PRIu64
720 ")\n",
721 reg, results->savedRegisters[reg].value, length);
722 break;
723 case DW_CFA_GNU_args_size:
724 length = addressSpace.getULEB128(p, instructionsEnd);
725 results->spExtraArgSize = (uint32_t)length;
726 _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_args_size(%" PRIu64 ")\n", length);
727 break;
728 case DW_CFA_GNU_negative_offset_extended:
729 reg = addressSpace.getULEB128(p, instructionsEnd);
730 if (reg > kMaxRegisterNumber) {
731 _LIBUNWIND_LOG0("malformed DW_CFA_GNU_negative_offset_extended DWARF "
732 "unwind, reg too big");
733 return false;
734 }
735 offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) *
736 cieInfo.dataAlignFactor;
737 results->setRegister(reg, kRegisterInCFA, -offset, initialState);
738 _LIBUNWIND_TRACE_DWARF(
739 "DW_CFA_GNU_negative_offset_extended(%" PRId64 ")\n", offset);
740 break;
741
742 #if defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_SPARC) || \
743 defined(_LIBUNWIND_TARGET_SPARC64)
744 // The same constant is used to represent different instructions on
745 // AArch64 (negate_ra_state) and SPARC (window_save).
746 static_assert(DW_CFA_AARCH64_negate_ra_state == DW_CFA_GNU_window_save,
747 "uses the same constant");
748 case DW_CFA_AARCH64_negate_ra_state:
749 switch (arch) {
750 #if defined(_LIBUNWIND_TARGET_AARCH64)
751 case REGISTERS_ARM64: {
752 int64_t value =
753 results->savedRegisters[UNW_AARCH64_RA_SIGN_STATE].value ^ 0x1;
754 results->setRegisterValue(UNW_AARCH64_RA_SIGN_STATE, value,
755 initialState);
756 _LIBUNWIND_TRACE_DWARF("DW_CFA_AARCH64_negate_ra_state\n");
757 } break;
758 #endif
759
760 #if defined(_LIBUNWIND_TARGET_SPARC)
761 // case DW_CFA_GNU_window_save:
762 case REGISTERS_SPARC:
763 _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_window_save()\n");
764 for (reg = UNW_SPARC_O0; reg <= UNW_SPARC_O7; reg++) {
765 results->setRegister(reg, kRegisterInRegister,
766 ((int64_t)reg - UNW_SPARC_O0) + UNW_SPARC_I0,
767 initialState);
768 }
769
770 for (reg = UNW_SPARC_L0; reg <= UNW_SPARC_I7; reg++) {
771 results->setRegister(reg, kRegisterInCFA,
772 ((int64_t)reg - UNW_SPARC_L0) * 4,
773 initialState);
774 }
775 break;
776 #endif
777
778 #if defined(_LIBUNWIND_TARGET_SPARC64)
779 // case DW_CFA_GNU_window_save:
780 case REGISTERS_SPARC64:
781 // Don't save %o0-%o7 on sparc64.
782 // https://reviews.llvm.org/D32450#736405
783
784 for (reg = UNW_SPARC_L0; reg <= UNW_SPARC_I7; reg++) {
785 if (reg == UNW_SPARC_I7)
786 results->setRegister(
787 reg, kRegisterInCFADecrypt,
788 static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)),
789 initialState);
790 else
791 results->setRegister(
792 reg, kRegisterInCFA,
793 static_cast<int64_t>((reg - UNW_SPARC_L0) * sizeof(pint_t)),
794 initialState);
795 }
796 _LIBUNWIND_TRACE_DWARF("DW_CFA_GNU_window_save\n");
797 break;
798 #endif
799 }
800 break;
801
802 #else
803 (void)arch;
804 #endif
805
806 default:
807 operand = opcode & 0x3F;
808 switch (opcode & 0xC0) {
809 case DW_CFA_offset:
810 reg = operand;
811 if (reg > kMaxRegisterNumber) {
812 _LIBUNWIND_LOG("malformed DW_CFA_offset DWARF unwind, reg (%" PRIu64
813 ") out of range",
814 reg);
815 return false;
816 }
817 offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) *
818 cieInfo.dataAlignFactor;
819 results->setRegister(reg, kRegisterInCFA, offset, initialState);
820 _LIBUNWIND_TRACE_DWARF("DW_CFA_offset(reg=%d, offset=%" PRId64 ")\n",
821 operand, offset);
822 break;
823 case DW_CFA_advance_loc:
824 codeOffset += operand * cieInfo.codeAlignFactor;
825 _LIBUNWIND_TRACE_DWARF("DW_CFA_advance_loc: new offset=%" PRIu64 "\n",
826 static_cast<uint64_t>(codeOffset));
827 break;
828 case DW_CFA_restore:
829 reg = operand;
830 if (reg > kMaxRegisterNumber) {
831 _LIBUNWIND_LOG(
832 "malformed DW_CFA_restore DWARF unwind, reg (%" PRIu64
833 ") out of range",
834 reg);
835 return false;
836 }
837 results->restoreRegisterToInitialState(reg, initialState);
838 _LIBUNWIND_TRACE_DWARF("DW_CFA_restore(reg=%" PRIu64 ")\n",
839 static_cast<uint64_t>(operand));
840 break;
841 default:
842 _LIBUNWIND_TRACE_DWARF("unknown CFA opcode 0x%02X\n", opcode);
843 return false;
844 }
845 }
846 }
847 }
848 return true;
849 }
850
851 } // namespace libunwind
852
853 #endif // __DWARF_PARSER_HPP__
854