1 //===------------------------- UnwindCursor.hpp ---------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 // 9 // C++ interface to lower levels of libuwind 10 //===----------------------------------------------------------------------===// 11 12 #ifndef __UNWINDCURSOR_HPP__ 13 #define __UNWINDCURSOR_HPP__ 14 15 #include <algorithm> 16 #include <stdint.h> 17 #include <stdio.h> 18 #include <stdlib.h> 19 #include <pthread.h> 20 #include <unwind.h> 21 22 #ifdef __APPLE__ 23 #include <mach-o/dyld.h> 24 #endif 25 26 #include "config.h" 27 28 #include "AddressSpace.hpp" 29 #include "CompactUnwinder.hpp" 30 #include "config.h" 31 #include "DwarfInstructions.hpp" 32 #include "EHHeaderParser.hpp" 33 #include "libunwind.h" 34 #include "Registers.hpp" 35 #include "Unwind-EHABI.h" 36 37 namespace libunwind { 38 39 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 40 /// Cache of recently found FDEs. 41 template <typename A> 42 class _LIBUNWIND_HIDDEN DwarfFDECache { 43 typedef typename A::pint_t pint_t; 44 public: 45 static pint_t findFDE(pint_t mh, pint_t pc); 46 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde); 47 static void removeAllIn(pint_t mh); 48 static void iterateCacheEntries(void (*func)(unw_word_t ip_start, 49 unw_word_t ip_end, 50 unw_word_t fde, unw_word_t mh)); 51 52 private: 53 54 struct entry { 55 pint_t mh; 56 pint_t ip_start; 57 pint_t ip_end; 58 pint_t fde; 59 }; 60 61 // These fields are all static to avoid needing an initializer. 62 // There is only one instance of this class per process. 63 static pthread_rwlock_t _lock; 64 #ifdef __APPLE__ 65 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide); 66 static bool _registeredForDyldUnloads; 67 #endif 68 // Can't use std::vector<> here because this code is below libc++. 69 static entry *_buffer; 70 static entry *_bufferUsed; 71 static entry *_bufferEnd; 72 static entry _initialBuffer[64]; 73 }; 74 75 template <typename A> 76 typename DwarfFDECache<A>::entry * 77 DwarfFDECache<A>::_buffer = _initialBuffer; 78 79 template <typename A> 80 typename DwarfFDECache<A>::entry * 81 DwarfFDECache<A>::_bufferUsed = _initialBuffer; 82 83 template <typename A> 84 typename DwarfFDECache<A>::entry * 85 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64]; 86 87 template <typename A> 88 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64]; 89 90 template <typename A> 91 pthread_rwlock_t DwarfFDECache<A>::_lock = PTHREAD_RWLOCK_INITIALIZER; 92 93 #ifdef __APPLE__ 94 template <typename A> 95 bool DwarfFDECache<A>::_registeredForDyldUnloads = false; 96 #endif 97 98 template <typename A> 99 typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) { 100 pint_t result = 0; 101 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_rdlock(&_lock)); 102 for (entry *p = _buffer; p < _bufferUsed; ++p) { 103 if ((mh == p->mh) || (mh == 0)) { 104 if ((p->ip_start <= pc) && (pc < p->ip_end)) { 105 result = p->fde; 106 break; 107 } 108 } 109 } 110 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 111 return result; 112 } 113 114 template <typename A> 115 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end, 116 pint_t fde) { 117 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock)); 118 if (_bufferUsed >= _bufferEnd) { 119 size_t oldSize = (size_t)(_bufferEnd - _buffer); 120 size_t newSize = oldSize * 4; 121 // Can't use operator new (we are below it). 122 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry)); 123 memcpy(newBuffer, _buffer, oldSize * sizeof(entry)); 124 if (_buffer != _initialBuffer) 125 free(_buffer); 126 _buffer = newBuffer; 127 _bufferUsed = &newBuffer[oldSize]; 128 _bufferEnd = &newBuffer[newSize]; 129 } 130 _bufferUsed->mh = mh; 131 _bufferUsed->ip_start = ip_start; 132 _bufferUsed->ip_end = ip_end; 133 _bufferUsed->fde = fde; 134 ++_bufferUsed; 135 #ifdef __APPLE__ 136 if (!_registeredForDyldUnloads) { 137 _dyld_register_func_for_remove_image(&dyldUnloadHook); 138 _registeredForDyldUnloads = true; 139 } 140 #endif 141 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 142 } 143 144 template <typename A> 145 void DwarfFDECache<A>::removeAllIn(pint_t mh) { 146 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock)); 147 entry *d = _buffer; 148 for (const entry *s = _buffer; s < _bufferUsed; ++s) { 149 if (s->mh != mh) { 150 if (d != s) 151 *d = *s; 152 ++d; 153 } 154 } 155 _bufferUsed = d; 156 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 157 } 158 159 #ifdef __APPLE__ 160 template <typename A> 161 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) { 162 removeAllIn((pint_t) mh); 163 } 164 #endif 165 166 template <typename A> 167 void DwarfFDECache<A>::iterateCacheEntries(void (*func)( 168 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) { 169 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock)); 170 for (entry *p = _buffer; p < _bufferUsed; ++p) { 171 (*func)(p->ip_start, p->ip_end, p->fde, p->mh); 172 } 173 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 174 } 175 #endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 176 177 178 #define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field)) 179 180 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 181 template <typename A> class UnwindSectionHeader { 182 public: 183 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr) 184 : _addressSpace(addressSpace), _addr(addr) {} 185 186 uint32_t version() const { 187 return _addressSpace.get32(_addr + 188 offsetof(unwind_info_section_header, version)); 189 } 190 uint32_t commonEncodingsArraySectionOffset() const { 191 return _addressSpace.get32(_addr + 192 offsetof(unwind_info_section_header, 193 commonEncodingsArraySectionOffset)); 194 } 195 uint32_t commonEncodingsArrayCount() const { 196 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 197 commonEncodingsArrayCount)); 198 } 199 uint32_t personalityArraySectionOffset() const { 200 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 201 personalityArraySectionOffset)); 202 } 203 uint32_t personalityArrayCount() const { 204 return _addressSpace.get32( 205 _addr + offsetof(unwind_info_section_header, personalityArrayCount)); 206 } 207 uint32_t indexSectionOffset() const { 208 return _addressSpace.get32( 209 _addr + offsetof(unwind_info_section_header, indexSectionOffset)); 210 } 211 uint32_t indexCount() const { 212 return _addressSpace.get32( 213 _addr + offsetof(unwind_info_section_header, indexCount)); 214 } 215 216 private: 217 A &_addressSpace; 218 typename A::pint_t _addr; 219 }; 220 221 template <typename A> class UnwindSectionIndexArray { 222 public: 223 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr) 224 : _addressSpace(addressSpace), _addr(addr) {} 225 226 uint32_t functionOffset(uint32_t index) const { 227 return _addressSpace.get32( 228 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 229 functionOffset)); 230 } 231 uint32_t secondLevelPagesSectionOffset(uint32_t index) const { 232 return _addressSpace.get32( 233 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 234 secondLevelPagesSectionOffset)); 235 } 236 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const { 237 return _addressSpace.get32( 238 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 239 lsdaIndexArraySectionOffset)); 240 } 241 242 private: 243 A &_addressSpace; 244 typename A::pint_t _addr; 245 }; 246 247 template <typename A> class UnwindSectionRegularPageHeader { 248 public: 249 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr) 250 : _addressSpace(addressSpace), _addr(addr) {} 251 252 uint32_t kind() const { 253 return _addressSpace.get32( 254 _addr + offsetof(unwind_info_regular_second_level_page_header, kind)); 255 } 256 uint16_t entryPageOffset() const { 257 return _addressSpace.get16( 258 _addr + offsetof(unwind_info_regular_second_level_page_header, 259 entryPageOffset)); 260 } 261 uint16_t entryCount() const { 262 return _addressSpace.get16( 263 _addr + 264 offsetof(unwind_info_regular_second_level_page_header, entryCount)); 265 } 266 267 private: 268 A &_addressSpace; 269 typename A::pint_t _addr; 270 }; 271 272 template <typename A> class UnwindSectionRegularArray { 273 public: 274 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr) 275 : _addressSpace(addressSpace), _addr(addr) {} 276 277 uint32_t functionOffset(uint32_t index) const { 278 return _addressSpace.get32( 279 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index, 280 functionOffset)); 281 } 282 uint32_t encoding(uint32_t index) const { 283 return _addressSpace.get32( 284 _addr + 285 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding)); 286 } 287 288 private: 289 A &_addressSpace; 290 typename A::pint_t _addr; 291 }; 292 293 template <typename A> class UnwindSectionCompressedPageHeader { 294 public: 295 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr) 296 : _addressSpace(addressSpace), _addr(addr) {} 297 298 uint32_t kind() const { 299 return _addressSpace.get32( 300 _addr + 301 offsetof(unwind_info_compressed_second_level_page_header, kind)); 302 } 303 uint16_t entryPageOffset() const { 304 return _addressSpace.get16( 305 _addr + offsetof(unwind_info_compressed_second_level_page_header, 306 entryPageOffset)); 307 } 308 uint16_t entryCount() const { 309 return _addressSpace.get16( 310 _addr + 311 offsetof(unwind_info_compressed_second_level_page_header, entryCount)); 312 } 313 uint16_t encodingsPageOffset() const { 314 return _addressSpace.get16( 315 _addr + offsetof(unwind_info_compressed_second_level_page_header, 316 encodingsPageOffset)); 317 } 318 uint16_t encodingsCount() const { 319 return _addressSpace.get16( 320 _addr + offsetof(unwind_info_compressed_second_level_page_header, 321 encodingsCount)); 322 } 323 324 private: 325 A &_addressSpace; 326 typename A::pint_t _addr; 327 }; 328 329 template <typename A> class UnwindSectionCompressedArray { 330 public: 331 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr) 332 : _addressSpace(addressSpace), _addr(addr) {} 333 334 uint32_t functionOffset(uint32_t index) const { 335 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET( 336 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 337 } 338 uint16_t encodingIndex(uint32_t index) const { 339 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX( 340 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 341 } 342 343 private: 344 A &_addressSpace; 345 typename A::pint_t _addr; 346 }; 347 348 template <typename A> class UnwindSectionLsdaArray { 349 public: 350 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr) 351 : _addressSpace(addressSpace), _addr(addr) {} 352 353 uint32_t functionOffset(uint32_t index) const { 354 return _addressSpace.get32( 355 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 356 index, functionOffset)); 357 } 358 uint32_t lsdaOffset(uint32_t index) const { 359 return _addressSpace.get32( 360 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 361 index, lsdaOffset)); 362 } 363 364 private: 365 A &_addressSpace; 366 typename A::pint_t _addr; 367 }; 368 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 369 370 class _LIBUNWIND_HIDDEN AbstractUnwindCursor { 371 public: 372 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20) 373 // This avoids an unnecessary dependency to libc++abi. 374 void operator delete(void *, size_t) {} 375 376 virtual ~AbstractUnwindCursor() {} 377 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); } 378 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); } 379 virtual void setReg(int, unw_word_t) { 380 _LIBUNWIND_ABORT("setReg not implemented"); 381 } 382 virtual bool validFloatReg(int) { 383 _LIBUNWIND_ABORT("validFloatReg not implemented"); 384 } 385 virtual unw_fpreg_t getFloatReg(int) { 386 _LIBUNWIND_ABORT("getFloatReg not implemented"); 387 } 388 virtual void setFloatReg(int, unw_fpreg_t) { 389 _LIBUNWIND_ABORT("setFloatReg not implemented"); 390 } 391 virtual int step() { _LIBUNWIND_ABORT("step not implemented"); } 392 virtual void getInfo(unw_proc_info_t *) { 393 _LIBUNWIND_ABORT("getInfo not implemented"); 394 } 395 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); } 396 virtual bool isSignalFrame() { 397 _LIBUNWIND_ABORT("isSignalFrame not implemented"); 398 } 399 virtual bool getFunctionName(char *, size_t, unw_word_t *) { 400 _LIBUNWIND_ABORT("getFunctionName not implemented"); 401 } 402 virtual void setInfoBasedOnIPRegister(bool = false) { 403 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented"); 404 } 405 virtual const char *getRegisterName(int) { 406 _LIBUNWIND_ABORT("getRegisterName not implemented"); 407 } 408 #ifdef __arm__ 409 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); } 410 #endif 411 }; 412 413 /// UnwindCursor contains all state (including all register values) during 414 /// an unwind. This is normally stack allocated inside a unw_cursor_t. 415 template <typename A, typename R> 416 class UnwindCursor : public AbstractUnwindCursor{ 417 typedef typename A::pint_t pint_t; 418 public: 419 UnwindCursor(unw_context_t *context, A &as); 420 UnwindCursor(A &as, void *threadArg); 421 virtual ~UnwindCursor() {} 422 virtual bool validReg(int); 423 virtual unw_word_t getReg(int); 424 virtual void setReg(int, unw_word_t); 425 virtual bool validFloatReg(int); 426 virtual unw_fpreg_t getFloatReg(int); 427 virtual void setFloatReg(int, unw_fpreg_t); 428 virtual int step(); 429 virtual void getInfo(unw_proc_info_t *); 430 virtual void jumpto(); 431 virtual bool isSignalFrame(); 432 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off); 433 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false); 434 virtual const char *getRegisterName(int num); 435 #ifdef __arm__ 436 virtual void saveVFPAsX(); 437 #endif 438 439 private: 440 441 #if LIBCXXABI_ARM_EHABI 442 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s); 443 #endif 444 445 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 446 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s, 447 uint32_t fdeSectionOffsetHint=0); 448 int stepWithDwarfFDE() { 449 return DwarfInstructions<A, R>::stepWithDwarf(_addressSpace, 450 (pint_t)this->getReg(UNW_REG_IP), 451 (pint_t)_info.unwind_info, 452 _registers); 453 } 454 #endif 455 456 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 457 bool getInfoFromCompactEncodingSection(pint_t pc, 458 const UnwindInfoSections §s); 459 int stepWithCompactEncoding() { 460 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 461 if ( compactSaysUseDwarf() ) 462 return stepWithDwarfFDE(); 463 #endif 464 R dummy; 465 return stepWithCompactEncoding(dummy); 466 } 467 468 int stepWithCompactEncoding(Registers_x86_64 &) { 469 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding( 470 _info.format, _info.start_ip, _addressSpace, _registers); 471 } 472 473 int stepWithCompactEncoding(Registers_x86 &) { 474 return CompactUnwinder_x86<A>::stepWithCompactEncoding( 475 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers); 476 } 477 478 int stepWithCompactEncoding(Registers_ppc &) { 479 return UNW_EINVAL; 480 } 481 482 int stepWithCompactEncoding(Registers_arm64 &) { 483 return CompactUnwinder_arm64<A>::stepWithCompactEncoding( 484 _info.format, _info.start_ip, _addressSpace, _registers); 485 } 486 487 bool compactSaysUseDwarf(uint32_t *offset=NULL) const { 488 R dummy; 489 return compactSaysUseDwarf(dummy, offset); 490 } 491 492 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const { 493 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) { 494 if (offset) 495 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET); 496 return true; 497 } 498 return false; 499 } 500 501 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const { 502 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) { 503 if (offset) 504 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET); 505 return true; 506 } 507 return false; 508 } 509 510 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const { 511 return true; 512 } 513 514 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const { 515 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) { 516 if (offset) 517 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET); 518 return true; 519 } 520 return false; 521 } 522 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 523 524 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 525 compact_unwind_encoding_t dwarfEncoding() const { 526 R dummy; 527 return dwarfEncoding(dummy); 528 } 529 530 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const { 531 return UNWIND_X86_64_MODE_DWARF; 532 } 533 534 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const { 535 return UNWIND_X86_MODE_DWARF; 536 } 537 538 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const { 539 return 0; 540 } 541 542 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const { 543 return UNWIND_ARM64_MODE_DWARF; 544 } 545 #endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 546 547 548 A &_addressSpace; 549 R _registers; 550 unw_proc_info_t _info; 551 bool _unwindInfoMissing; 552 bool _isSignalFrame; 553 }; 554 555 556 template <typename A, typename R> 557 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as) 558 : _addressSpace(as), _registers(context), _unwindInfoMissing(false), 559 _isSignalFrame(false) { 560 static_assert(sizeof(UnwindCursor<A, R>) < sizeof(unw_cursor_t), 561 "UnwindCursor<> does not fit in unw_cursor_t"); 562 memset(&_info, 0, sizeof(_info)); 563 } 564 565 template <typename A, typename R> 566 UnwindCursor<A, R>::UnwindCursor(A &as, void *) 567 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) { 568 memset(&_info, 0, sizeof(_info)); 569 // FIXME 570 // fill in _registers from thread arg 571 } 572 573 574 template <typename A, typename R> 575 bool UnwindCursor<A, R>::validReg(int regNum) { 576 return _registers.validRegister(regNum); 577 } 578 579 template <typename A, typename R> 580 unw_word_t UnwindCursor<A, R>::getReg(int regNum) { 581 return _registers.getRegister(regNum); 582 } 583 584 template <typename A, typename R> 585 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) { 586 _registers.setRegister(regNum, (typename A::pint_t)value); 587 } 588 589 template <typename A, typename R> 590 bool UnwindCursor<A, R>::validFloatReg(int regNum) { 591 return _registers.validFloatRegister(regNum); 592 } 593 594 template <typename A, typename R> 595 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) { 596 return _registers.getFloatRegister(regNum); 597 } 598 599 template <typename A, typename R> 600 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) { 601 _registers.setFloatRegister(regNum, value); 602 } 603 604 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() { 605 _registers.jumpto(); 606 } 607 608 #ifdef __arm__ 609 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() { 610 _registers.saveVFPAsX(); 611 } 612 #endif 613 614 template <typename A, typename R> 615 const char *UnwindCursor<A, R>::getRegisterName(int regNum) { 616 return _registers.getRegisterName(regNum); 617 } 618 619 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() { 620 return _isSignalFrame; 621 } 622 623 #if LIBCXXABI_ARM_EHABI 624 struct EHABIIndexEntry { 625 uint32_t functionOffset; 626 uint32_t data; 627 }; 628 629 template<typename A> 630 struct EHABISectionIterator { 631 typedef EHABISectionIterator _Self; 632 633 typedef std::random_access_iterator_tag iterator_category; 634 typedef typename A::pint_t value_type; 635 typedef typename A::pint_t* pointer; 636 typedef typename A::pint_t& reference; 637 typedef size_t size_type; 638 typedef size_t difference_type; 639 640 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) { 641 return _Self(addressSpace, sects, 0); 642 } 643 static _Self end(A& addressSpace, const UnwindInfoSections& sects) { 644 return _Self(addressSpace, sects, sects.arm_section_length); 645 } 646 647 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i) 648 : _i(i), _addressSpace(&addressSpace), _sects(§s) {} 649 650 _Self& operator++() { ++_i; return *this; } 651 _Self& operator+=(size_t a) { _i += a; return *this; } 652 _Self& operator--() { assert(_i > 0); --_i; return *this; } 653 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; } 654 655 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; } 656 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; } 657 658 size_t operator-(const _Self& other) { return _i - other._i; } 659 660 bool operator==(const _Self& other) const { 661 assert(_addressSpace == other._addressSpace); 662 assert(_sects == other._sects); 663 return _i == other._i; 664 } 665 666 typename A::pint_t operator*() const { return functionAddress(); } 667 668 typename A::pint_t functionAddress() const { 669 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 670 EHABIIndexEntry, _i, functionOffset); 671 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr)); 672 } 673 674 typename A::pint_t dataAddress() { 675 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 676 EHABIIndexEntry, _i, data); 677 return indexAddr; 678 } 679 680 private: 681 size_t _i; 682 A* _addressSpace; 683 const UnwindInfoSections* _sects; 684 }; 685 686 template <typename A, typename R> 687 bool UnwindCursor<A, R>::getInfoFromEHABISection( 688 pint_t pc, 689 const UnwindInfoSections §s) { 690 EHABISectionIterator<A> begin = 691 EHABISectionIterator<A>::begin(_addressSpace, sects); 692 EHABISectionIterator<A> end = 693 EHABISectionIterator<A>::end(_addressSpace, sects); 694 695 EHABISectionIterator<A> itNextPC = std::upper_bound(begin, end, pc); 696 if (itNextPC == begin || itNextPC == end) 697 return false; 698 EHABISectionIterator<A> itThisPC = itNextPC - 1; 699 700 pint_t thisPC = itThisPC.functionAddress(); 701 pint_t nextPC = itNextPC.functionAddress(); 702 pint_t indexDataAddr = itThisPC.dataAddress(); 703 704 if (indexDataAddr == 0) 705 return false; 706 707 uint32_t indexData = _addressSpace.get32(indexDataAddr); 708 if (indexData == UNW_EXIDX_CANTUNWIND) 709 return false; 710 711 // If the high bit is set, the exception handling table entry is inline inside 712 // the index table entry on the second word (aka |indexDataAddr|). Otherwise, 713 // the table points at an offset in the exception handling table (section 5 EHABI). 714 pint_t exceptionTableAddr; 715 uint32_t exceptionTableData; 716 bool isSingleWordEHT; 717 if (indexData & 0x80000000) { 718 exceptionTableAddr = indexDataAddr; 719 // TODO(ajwong): Should this data be 0? 720 exceptionTableData = indexData; 721 isSingleWordEHT = true; 722 } else { 723 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData); 724 exceptionTableData = _addressSpace.get32(exceptionTableAddr); 725 isSingleWordEHT = false; 726 } 727 728 // Now we know the 3 things: 729 // exceptionTableAddr -- exception handler table entry. 730 // exceptionTableData -- the data inside the first word of the eht entry. 731 // isSingleWordEHT -- whether the entry is in the index. 732 unw_word_t personalityRoutine = 0xbadf00d; 733 bool scope32 = false; 734 uintptr_t lsda = 0xbadf00d; 735 736 // If the high bit in the exception handling table entry is set, the entry is 737 // in compact form (section 6.3 EHABI). 738 if (exceptionTableData & 0x80000000) { 739 // Grab the index of the personality routine from the compact form. 740 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24; 741 uint32_t extraWords = 0; 742 switch (choice) { 743 case 0: 744 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0; 745 extraWords = 0; 746 scope32 = false; 747 break; 748 case 1: 749 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1; 750 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 751 scope32 = false; 752 break; 753 case 2: 754 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2; 755 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 756 scope32 = true; 757 break; 758 default: 759 _LIBUNWIND_ABORT("unknown personality routine"); 760 return false; 761 } 762 763 if (isSingleWordEHT) { 764 if (extraWords != 0) { 765 _LIBUNWIND_ABORT("index inlined table detected but pr function " 766 "requires extra words"); 767 return false; 768 } 769 } 770 } else { 771 pint_t personalityAddr = 772 exceptionTableAddr + signExtendPrel31(exceptionTableData); 773 personalityRoutine = personalityAddr; 774 775 // ARM EHABI # 6.2, # 9.2 776 // 777 // +---- ehtp 778 // v 779 // +--------------------------------------+ 780 // | +--------+--------+--------+-------+ | 781 // | |0| prel31 to personalityRoutine | | 782 // | +--------+--------+--------+-------+ | 783 // | | N | unwind opcodes | | <-- UnwindData 784 // | +--------+--------+--------+-------+ | 785 // | | Word 2 unwind opcodes | | 786 // | +--------+--------+--------+-------+ | 787 // | ... | 788 // | +--------+--------+--------+-------+ | 789 // | | Word N unwind opcodes | | 790 // | +--------+--------+--------+-------+ | 791 // | | LSDA | | <-- lsda 792 // | | ... | | 793 // | +--------+--------+--------+-------+ | 794 // +--------------------------------------+ 795 796 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1; 797 uint32_t FirstDataWord = *UnwindData; 798 size_t N = ((FirstDataWord >> 24) & 0xff); 799 size_t NDataWords = N + 1; 800 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords); 801 } 802 803 _info.start_ip = thisPC; 804 _info.end_ip = nextPC; 805 _info.handler = personalityRoutine; 806 _info.unwind_info = exceptionTableAddr; 807 _info.lsda = lsda; 808 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0. 809 _info.flags = isSingleWordEHT ? 1 : 0 | scope32 ? 0x2 : 0; // Use enum? 810 811 return true; 812 } 813 #endif 814 815 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 816 template <typename A, typename R> 817 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc, 818 const UnwindInfoSections §s, 819 uint32_t fdeSectionOffsetHint) { 820 typename CFI_Parser<A>::FDE_Info fdeInfo; 821 typename CFI_Parser<A>::CIE_Info cieInfo; 822 bool foundFDE = false; 823 bool foundInCache = false; 824 // If compact encoding table gave offset into dwarf section, go directly there 825 if (fdeSectionOffsetHint != 0) { 826 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 827 (uint32_t)sects.dwarf_section_length, 828 sects.dwarf_section + fdeSectionOffsetHint, 829 &fdeInfo, &cieInfo); 830 } 831 #if _LIBUNWIND_SUPPORT_DWARF_INDEX 832 if (!foundFDE && (sects.dwarf_index_section != 0)) { 833 foundFDE = EHHeaderParser<A>::findFDE( 834 _addressSpace, pc, sects.dwarf_index_section, 835 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo); 836 } 837 #endif 838 if (!foundFDE) { 839 // otherwise, search cache of previously found FDEs. 840 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc); 841 if (cachedFDE != 0) { 842 foundFDE = 843 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 844 (uint32_t)sects.dwarf_section_length, 845 cachedFDE, &fdeInfo, &cieInfo); 846 foundInCache = foundFDE; 847 } 848 } 849 if (!foundFDE) { 850 // Still not found, do full scan of __eh_frame section. 851 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 852 (uint32_t)sects.dwarf_section_length, 0, 853 &fdeInfo, &cieInfo); 854 } 855 if (foundFDE) { 856 typename CFI_Parser<A>::PrologInfo prolog; 857 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc, 858 &prolog)) { 859 // Save off parsed FDE info 860 _info.start_ip = fdeInfo.pcStart; 861 _info.end_ip = fdeInfo.pcEnd; 862 _info.lsda = fdeInfo.lsda; 863 _info.handler = cieInfo.personality; 864 _info.gp = prolog.spExtraArgSize; 865 _info.flags = 0; 866 _info.format = dwarfEncoding(); 867 _info.unwind_info = fdeInfo.fdeStart; 868 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 869 _info.extra = (unw_word_t) sects.dso_base; 870 871 // Add to cache (to make next lookup faster) if we had no hint 872 // and there was no index. 873 if (!foundInCache && (fdeSectionOffsetHint == 0)) { 874 #if _LIBUNWIND_SUPPORT_DWARF_INDEX 875 if (sects.dwarf_index_section == 0) 876 #endif 877 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd, 878 fdeInfo.fdeStart); 879 } 880 return true; 881 } 882 } 883 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX\n", (uint64_t)pc); 884 return false; 885 } 886 #endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 887 888 889 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 890 template <typename A, typename R> 891 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc, 892 const UnwindInfoSections §s) { 893 const bool log = false; 894 if (log) 895 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n", 896 (uint64_t)pc, (uint64_t)sects.dso_base); 897 898 const UnwindSectionHeader<A> sectionHeader(_addressSpace, 899 sects.compact_unwind_section); 900 if (sectionHeader.version() != UNWIND_SECTION_VERSION) 901 return false; 902 903 // do a binary search of top level index to find page with unwind info 904 pint_t targetFunctionOffset = pc - sects.dso_base; 905 const UnwindSectionIndexArray<A> topIndex(_addressSpace, 906 sects.compact_unwind_section 907 + sectionHeader.indexSectionOffset()); 908 uint32_t low = 0; 909 uint32_t high = sectionHeader.indexCount(); 910 uint32_t last = high - 1; 911 while (low < high) { 912 uint32_t mid = (low + high) / 2; 913 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n", 914 //mid, low, high, topIndex.functionOffset(mid)); 915 if (topIndex.functionOffset(mid) <= targetFunctionOffset) { 916 if ((mid == last) || 917 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) { 918 low = mid; 919 break; 920 } else { 921 low = mid + 1; 922 } 923 } else { 924 high = mid; 925 } 926 } 927 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low); 928 const uint32_t firstLevelNextPageFunctionOffset = 929 topIndex.functionOffset(low + 1); 930 const pint_t secondLevelAddr = 931 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low); 932 const pint_t lsdaArrayStartAddr = 933 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low); 934 const pint_t lsdaArrayEndAddr = 935 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1); 936 if (log) 937 fprintf(stderr, "\tfirst level search for result index=%d " 938 "to secondLevelAddr=0x%llX\n", 939 low, (uint64_t) secondLevelAddr); 940 // do a binary search of second level page index 941 uint32_t encoding = 0; 942 pint_t funcStart = 0; 943 pint_t funcEnd = 0; 944 pint_t lsda = 0; 945 pint_t personality = 0; 946 uint32_t pageKind = _addressSpace.get32(secondLevelAddr); 947 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) { 948 // regular page 949 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace, 950 secondLevelAddr); 951 UnwindSectionRegularArray<A> pageIndex( 952 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 953 // binary search looks for entry with e where index[e].offset <= pc < 954 // index[e+1].offset 955 if (log) 956 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in " 957 "regular page starting at secondLevelAddr=0x%llX\n", 958 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr); 959 low = 0; 960 high = pageHeader.entryCount(); 961 while (low < high) { 962 uint32_t mid = (low + high) / 2; 963 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) { 964 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) { 965 // at end of table 966 low = mid; 967 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 968 break; 969 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) { 970 // next is too big, so we found it 971 low = mid; 972 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base; 973 break; 974 } else { 975 low = mid + 1; 976 } 977 } else { 978 high = mid; 979 } 980 } 981 encoding = pageIndex.encoding(low); 982 funcStart = pageIndex.functionOffset(low) + sects.dso_base; 983 if (pc < funcStart) { 984 if (log) 985 fprintf( 986 stderr, 987 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 988 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 989 return false; 990 } 991 if (pc > funcEnd) { 992 if (log) 993 fprintf( 994 stderr, 995 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 996 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 997 return false; 998 } 999 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) { 1000 // compressed page 1001 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace, 1002 secondLevelAddr); 1003 UnwindSectionCompressedArray<A> pageIndex( 1004 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 1005 const uint32_t targetFunctionPageOffset = 1006 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset); 1007 // binary search looks for entry with e where index[e].offset <= pc < 1008 // index[e+1].offset 1009 if (log) 1010 fprintf(stderr, "\tbinary search of compressed page starting at " 1011 "secondLevelAddr=0x%llX\n", 1012 (uint64_t) secondLevelAddr); 1013 low = 0; 1014 last = pageHeader.entryCount() - 1; 1015 high = pageHeader.entryCount(); 1016 while (low < high) { 1017 uint32_t mid = (low + high) / 2; 1018 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) { 1019 if ((mid == last) || 1020 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) { 1021 low = mid; 1022 break; 1023 } else { 1024 low = mid + 1; 1025 } 1026 } else { 1027 high = mid; 1028 } 1029 } 1030 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset 1031 + sects.dso_base; 1032 if (low < last) 1033 funcEnd = 1034 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset 1035 + sects.dso_base; 1036 else 1037 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 1038 if (pc < funcStart) { 1039 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1040 "level compressed unwind table. funcStart=0x%llX\n", 1041 (uint64_t) pc, (uint64_t) funcStart); 1042 return false; 1043 } 1044 if (pc > funcEnd) { 1045 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1046 "level compressed unwind table. funcEnd=0x%llX\n", 1047 (uint64_t) pc, (uint64_t) funcEnd); 1048 return false; 1049 } 1050 uint16_t encodingIndex = pageIndex.encodingIndex(low); 1051 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) { 1052 // encoding is in common table in section header 1053 encoding = _addressSpace.get32( 1054 sects.compact_unwind_section + 1055 sectionHeader.commonEncodingsArraySectionOffset() + 1056 encodingIndex * sizeof(uint32_t)); 1057 } else { 1058 // encoding is in page specific table 1059 uint16_t pageEncodingIndex = 1060 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount(); 1061 encoding = _addressSpace.get32(secondLevelAddr + 1062 pageHeader.encodingsPageOffset() + 1063 pageEncodingIndex * sizeof(uint32_t)); 1064 } 1065 } else { 1066 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info at 0x%0llX bad second " 1067 "level page\n", 1068 (uint64_t) sects.compact_unwind_section); 1069 return false; 1070 } 1071 1072 // look up LSDA, if encoding says function has one 1073 if (encoding & UNWIND_HAS_LSDA) { 1074 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr); 1075 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base); 1076 low = 0; 1077 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) / 1078 sizeof(unwind_info_section_header_lsda_index_entry); 1079 // binary search looks for entry with exact match for functionOffset 1080 if (log) 1081 fprintf(stderr, 1082 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n", 1083 funcStartOffset); 1084 while (low < high) { 1085 uint32_t mid = (low + high) / 2; 1086 if (lsdaIndex.functionOffset(mid) == funcStartOffset) { 1087 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base; 1088 break; 1089 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) { 1090 low = mid + 1; 1091 } else { 1092 high = mid; 1093 } 1094 } 1095 if (lsda == 0) { 1096 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for " 1097 "pc=0x%0llX, but lsda table has no entry\n", 1098 encoding, (uint64_t) pc); 1099 return false; 1100 } 1101 } 1102 1103 // extact personality routine, if encoding says function has one 1104 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >> 1105 (__builtin_ctz(UNWIND_PERSONALITY_MASK)); 1106 if (personalityIndex != 0) { 1107 --personalityIndex; // change 1-based to zero-based index 1108 if (personalityIndex > sectionHeader.personalityArrayCount()) { 1109 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, " 1110 "but personality table has only %d entires\n", 1111 encoding, personalityIndex, 1112 sectionHeader.personalityArrayCount()); 1113 return false; 1114 } 1115 int32_t personalityDelta = (int32_t)_addressSpace.get32( 1116 sects.compact_unwind_section + 1117 sectionHeader.personalityArraySectionOffset() + 1118 personalityIndex * sizeof(uint32_t)); 1119 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta; 1120 personality = _addressSpace.getP(personalityPointer); 1121 if (log) 1122 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1123 "personalityDelta=0x%08X, personality=0x%08llX\n", 1124 (uint64_t) pc, personalityDelta, (uint64_t) personality); 1125 } 1126 1127 if (log) 1128 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1129 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n", 1130 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart); 1131 _info.start_ip = funcStart; 1132 _info.end_ip = funcEnd; 1133 _info.lsda = lsda; 1134 _info.handler = personality; 1135 _info.gp = 0; 1136 _info.flags = 0; 1137 _info.format = encoding; 1138 _info.unwind_info = 0; 1139 _info.unwind_info_size = 0; 1140 _info.extra = sects.dso_base; 1141 return true; 1142 } 1143 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1144 1145 1146 template <typename A, typename R> 1147 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) { 1148 pint_t pc = (pint_t)this->getReg(UNW_REG_IP); 1149 #if LIBCXXABI_ARM_EHABI 1150 // Remove the thumb bit so the IP represents the actual instruction address. 1151 // This matches the behaviour of _Unwind_GetIP on arm. 1152 pc &= (pint_t)~0x1; 1153 #endif 1154 1155 // If the last line of a function is a "throw" the compiler sometimes 1156 // emits no instructions after the call to __cxa_throw. This means 1157 // the return address is actually the start of the next function. 1158 // To disambiguate this, back up the pc when we know it is a return 1159 // address. 1160 if (isReturnAddress) 1161 --pc; 1162 1163 // Ask address space object to find unwind sections for this pc. 1164 UnwindInfoSections sects; 1165 if (_addressSpace.findUnwindSections(pc, sects)) { 1166 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1167 // If there is a compact unwind encoding table, look there first. 1168 if (sects.compact_unwind_section != 0) { 1169 if (this->getInfoFromCompactEncodingSection(pc, sects)) { 1170 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1171 // Found info in table, done unless encoding says to use dwarf. 1172 uint32_t dwarfOffset; 1173 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) { 1174 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) { 1175 // found info in dwarf, done 1176 return; 1177 } 1178 } 1179 #endif 1180 // If unwind table has entry, but entry says there is no unwind info, 1181 // record that we have no unwind info. 1182 if (_info.format == 0) 1183 _unwindInfoMissing = true; 1184 return; 1185 } 1186 } 1187 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1188 1189 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1190 // If there is dwarf unwind info, look there next. 1191 if (sects.dwarf_section != 0) { 1192 if (this->getInfoFromDwarfSection(pc, sects)) { 1193 // found info in dwarf, done 1194 return; 1195 } 1196 } 1197 #endif 1198 1199 #if LIBCXXABI_ARM_EHABI 1200 // If there is ARM EHABI unwind info, look there next. 1201 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects)) 1202 return; 1203 #endif 1204 } 1205 1206 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1207 // There is no static unwind info for this pc. Look to see if an FDE was 1208 // dynamically registered for it. 1209 pint_t cachedFDE = DwarfFDECache<A>::findFDE(0, pc); 1210 if (cachedFDE != 0) { 1211 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1212 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1213 const char *msg = CFI_Parser<A>::decodeFDE(_addressSpace, 1214 cachedFDE, &fdeInfo, &cieInfo); 1215 if (msg == NULL) { 1216 typename CFI_Parser<A>::PrologInfo prolog; 1217 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, 1218 pc, &prolog)) { 1219 // save off parsed FDE info 1220 _info.start_ip = fdeInfo.pcStart; 1221 _info.end_ip = fdeInfo.pcEnd; 1222 _info.lsda = fdeInfo.lsda; 1223 _info.handler = cieInfo.personality; 1224 _info.gp = prolog.spExtraArgSize; 1225 // Some frameless functions need SP 1226 // altered when resuming in function. 1227 _info.flags = 0; 1228 _info.format = dwarfEncoding(); 1229 _info.unwind_info = fdeInfo.fdeStart; 1230 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1231 _info.extra = 0; 1232 return; 1233 } 1234 } 1235 } 1236 1237 // Lastly, ask AddressSpace object about platform specific ways to locate 1238 // other FDEs. 1239 pint_t fde; 1240 if (_addressSpace.findOtherFDE(pc, fde)) { 1241 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1242 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1243 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) { 1244 // Double check this FDE is for a function that includes the pc. 1245 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) { 1246 typename CFI_Parser<A>::PrologInfo prolog; 1247 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, 1248 cieInfo, pc, &prolog)) { 1249 // save off parsed FDE info 1250 _info.start_ip = fdeInfo.pcStart; 1251 _info.end_ip = fdeInfo.pcEnd; 1252 _info.lsda = fdeInfo.lsda; 1253 _info.handler = cieInfo.personality; 1254 _info.gp = prolog.spExtraArgSize; 1255 _info.flags = 0; 1256 _info.format = dwarfEncoding(); 1257 _info.unwind_info = fdeInfo.fdeStart; 1258 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1259 _info.extra = 0; 1260 return; 1261 } 1262 } 1263 } 1264 } 1265 #endif // #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1266 1267 // no unwind info, flag that we can't reliably unwind 1268 _unwindInfoMissing = true; 1269 } 1270 1271 template <typename A, typename R> 1272 int UnwindCursor<A, R>::step() { 1273 // Bottom of stack is defined is when unwind info cannot be found. 1274 if (_unwindInfoMissing) 1275 return UNW_STEP_END; 1276 1277 // Use unwinding info to modify register set as if function returned. 1278 int result; 1279 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1280 result = this->stepWithCompactEncoding(); 1281 #elif _LIBUNWIND_SUPPORT_DWARF_UNWIND 1282 result = this->stepWithDwarfFDE(); 1283 #elif LIBCXXABI_ARM_EHABI 1284 result = UNW_STEP_SUCCESS; 1285 #else 1286 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \ 1287 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \ 1288 LIBCXXABI_ARM_EHABI 1289 #endif 1290 1291 // update info based on new PC 1292 if (result == UNW_STEP_SUCCESS) { 1293 this->setInfoBasedOnIPRegister(true); 1294 if (_unwindInfoMissing) 1295 return UNW_STEP_END; 1296 if (_info.gp) 1297 setReg(UNW_REG_SP, getReg(UNW_REG_SP) + _info.gp); 1298 } 1299 1300 return result; 1301 } 1302 1303 template <typename A, typename R> 1304 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) { 1305 *info = _info; 1306 } 1307 1308 template <typename A, typename R> 1309 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen, 1310 unw_word_t *offset) { 1311 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP), 1312 buf, bufLen, offset); 1313 } 1314 1315 } // namespace libunwind 1316 1317 #endif // __UNWINDCURSOR_HPP__ 1318