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 #if __APPLE__ 23 #include <mach-o/dyld.h> 24 #endif 25 26 #include "libunwind.h" 27 28 #include "AddressSpace.hpp" 29 #include "Registers.hpp" 30 #include "DwarfInstructions.hpp" 31 #include "CompactUnwinder.hpp" 32 #include "config.h" 33 34 namespace libunwind { 35 36 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 37 /// Cache of recently found FDEs. 38 template <typename A> 39 class _LIBUNWIND_HIDDEN DwarfFDECache { 40 typedef typename A::pint_t pint_t; 41 public: 42 static pint_t findFDE(pint_t mh, pint_t pc); 43 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde); 44 static void removeAllIn(pint_t mh); 45 static void iterateCacheEntries(void (*func)(unw_word_t ip_start, 46 unw_word_t ip_end, 47 unw_word_t fde, unw_word_t mh)); 48 49 private: 50 51 struct entry { 52 pint_t mh; 53 pint_t ip_start; 54 pint_t ip_end; 55 pint_t fde; 56 }; 57 58 // These fields are all static to avoid needing an initializer. 59 // There is only one instance of this class per process. 60 static pthread_rwlock_t _lock; 61 #if __APPLE__ 62 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide); 63 static bool _registeredForDyldUnloads; 64 #endif 65 // Can't use std::vector<> here because this code is below libc++. 66 static entry *_buffer; 67 static entry *_bufferUsed; 68 static entry *_bufferEnd; 69 static entry _initialBuffer[64]; 70 }; 71 72 template <typename A> 73 typename DwarfFDECache<A>::entry * 74 DwarfFDECache<A>::_buffer = _initialBuffer; 75 76 template <typename A> 77 typename DwarfFDECache<A>::entry * 78 DwarfFDECache<A>::_bufferUsed = _initialBuffer; 79 80 template <typename A> 81 typename DwarfFDECache<A>::entry * 82 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64]; 83 84 template <typename A> 85 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64]; 86 87 template <typename A> 88 pthread_rwlock_t DwarfFDECache<A>::_lock = PTHREAD_RWLOCK_INITIALIZER; 89 90 #if __APPLE__ 91 template <typename A> 92 bool DwarfFDECache<A>::_registeredForDyldUnloads = false; 93 #endif 94 95 template <typename A> 96 typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) { 97 pint_t result = 0; 98 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_rdlock(&_lock)); 99 for (entry *p = _buffer; p < _bufferUsed; ++p) { 100 if ((mh == p->mh) || (mh == 0)) { 101 if ((p->ip_start <= pc) && (pc < p->ip_end)) { 102 result = p->fde; 103 break; 104 } 105 } 106 } 107 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 108 return result; 109 } 110 111 template <typename A> 112 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end, 113 pint_t fde) { 114 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock)); 115 if (_bufferUsed >= _bufferEnd) { 116 size_t oldSize = (size_t)(_bufferEnd - _buffer); 117 size_t newSize = oldSize * 4; 118 // Can't use operator new (we are below it). 119 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry)); 120 memcpy(newBuffer, _buffer, oldSize * sizeof(entry)); 121 if (_buffer != _initialBuffer) 122 free(_buffer); 123 _buffer = newBuffer; 124 _bufferUsed = &newBuffer[oldSize]; 125 _bufferEnd = &newBuffer[newSize]; 126 } 127 _bufferUsed->mh = mh; 128 _bufferUsed->ip_start = ip_start; 129 _bufferUsed->ip_end = ip_end; 130 _bufferUsed->fde = fde; 131 ++_bufferUsed; 132 #if __APPLE__ 133 if (!_registeredForDyldUnloads) { 134 _dyld_register_func_for_remove_image(&dyldUnloadHook); 135 _registeredForDyldUnloads = true; 136 } 137 #endif 138 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 139 } 140 141 template <typename A> 142 void DwarfFDECache<A>::removeAllIn(pint_t mh) { 143 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock)); 144 entry *d = _buffer; 145 for (const entry *s = _buffer; s < _bufferUsed; ++s) { 146 if (s->mh != mh) { 147 if (d != s) 148 *d = *s; 149 ++d; 150 } 151 } 152 _bufferUsed = d; 153 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 154 } 155 156 #if __APPLE__ 157 template <typename A> 158 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) { 159 removeAllIn((pint_t) mh); 160 } 161 #endif 162 163 template <typename A> 164 void DwarfFDECache<A>::iterateCacheEntries(void (*func)( 165 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) { 166 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock)); 167 for (entry *p = _buffer; p < _bufferUsed; ++p) { 168 (*func)(p->ip_start, p->ip_end, p->fde, p->mh); 169 } 170 _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock)); 171 } 172 #endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 173 174 175 #define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field)) 176 177 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 178 template <typename A> class UnwindSectionHeader { 179 public: 180 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr) 181 : _addressSpace(addressSpace), _addr(addr) {} 182 183 uint32_t version() const { 184 return _addressSpace.get32(_addr + 185 offsetof(unwind_info_section_header, version)); 186 } 187 uint32_t commonEncodingsArraySectionOffset() const { 188 return _addressSpace.get32(_addr + 189 offsetof(unwind_info_section_header, 190 commonEncodingsArraySectionOffset)); 191 } 192 uint32_t commonEncodingsArrayCount() const { 193 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 194 commonEncodingsArrayCount)); 195 } 196 uint32_t personalityArraySectionOffset() const { 197 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 198 personalityArraySectionOffset)); 199 } 200 uint32_t personalityArrayCount() const { 201 return _addressSpace.get32( 202 _addr + offsetof(unwind_info_section_header, personalityArrayCount)); 203 } 204 uint32_t indexSectionOffset() const { 205 return _addressSpace.get32( 206 _addr + offsetof(unwind_info_section_header, indexSectionOffset)); 207 } 208 uint32_t indexCount() const { 209 return _addressSpace.get32( 210 _addr + offsetof(unwind_info_section_header, indexCount)); 211 } 212 213 private: 214 A &_addressSpace; 215 typename A::pint_t _addr; 216 }; 217 218 template <typename A> class UnwindSectionIndexArray { 219 public: 220 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr) 221 : _addressSpace(addressSpace), _addr(addr) {} 222 223 uint32_t functionOffset(uint32_t index) const { 224 return _addressSpace.get32( 225 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 226 functionOffset)); 227 } 228 uint32_t secondLevelPagesSectionOffset(uint32_t index) const { 229 return _addressSpace.get32( 230 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 231 secondLevelPagesSectionOffset)); 232 } 233 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const { 234 return _addressSpace.get32( 235 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 236 lsdaIndexArraySectionOffset)); 237 } 238 239 private: 240 A &_addressSpace; 241 typename A::pint_t _addr; 242 }; 243 244 template <typename A> class UnwindSectionRegularPageHeader { 245 public: 246 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr) 247 : _addressSpace(addressSpace), _addr(addr) {} 248 249 uint32_t kind() const { 250 return _addressSpace.get32( 251 _addr + offsetof(unwind_info_regular_second_level_page_header, kind)); 252 } 253 uint16_t entryPageOffset() const { 254 return _addressSpace.get16( 255 _addr + offsetof(unwind_info_regular_second_level_page_header, 256 entryPageOffset)); 257 } 258 uint16_t entryCount() const { 259 return _addressSpace.get16( 260 _addr + 261 offsetof(unwind_info_regular_second_level_page_header, entryCount)); 262 } 263 264 private: 265 A &_addressSpace; 266 typename A::pint_t _addr; 267 }; 268 269 template <typename A> class UnwindSectionRegularArray { 270 public: 271 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr) 272 : _addressSpace(addressSpace), _addr(addr) {} 273 274 uint32_t functionOffset(uint32_t index) const { 275 return _addressSpace.get32( 276 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index, 277 functionOffset)); 278 } 279 uint32_t encoding(uint32_t index) const { 280 return _addressSpace.get32( 281 _addr + 282 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding)); 283 } 284 285 private: 286 A &_addressSpace; 287 typename A::pint_t _addr; 288 }; 289 290 template <typename A> class UnwindSectionCompressedPageHeader { 291 public: 292 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr) 293 : _addressSpace(addressSpace), _addr(addr) {} 294 295 uint32_t kind() const { 296 return _addressSpace.get32( 297 _addr + 298 offsetof(unwind_info_compressed_second_level_page_header, kind)); 299 } 300 uint16_t entryPageOffset() const { 301 return _addressSpace.get16( 302 _addr + offsetof(unwind_info_compressed_second_level_page_header, 303 entryPageOffset)); 304 } 305 uint16_t entryCount() const { 306 return _addressSpace.get16( 307 _addr + 308 offsetof(unwind_info_compressed_second_level_page_header, entryCount)); 309 } 310 uint16_t encodingsPageOffset() const { 311 return _addressSpace.get16( 312 _addr + offsetof(unwind_info_compressed_second_level_page_header, 313 encodingsPageOffset)); 314 } 315 uint16_t encodingsCount() const { 316 return _addressSpace.get16( 317 _addr + offsetof(unwind_info_compressed_second_level_page_header, 318 encodingsCount)); 319 } 320 321 private: 322 A &_addressSpace; 323 typename A::pint_t _addr; 324 }; 325 326 template <typename A> class UnwindSectionCompressedArray { 327 public: 328 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr) 329 : _addressSpace(addressSpace), _addr(addr) {} 330 331 uint32_t functionOffset(uint32_t index) const { 332 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET( 333 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 334 } 335 uint16_t encodingIndex(uint32_t index) const { 336 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX( 337 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 338 } 339 340 private: 341 A &_addressSpace; 342 typename A::pint_t _addr; 343 }; 344 345 template <typename A> class UnwindSectionLsdaArray { 346 public: 347 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr) 348 : _addressSpace(addressSpace), _addr(addr) {} 349 350 uint32_t functionOffset(uint32_t index) const { 351 return _addressSpace.get32( 352 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 353 index, functionOffset)); 354 } 355 uint32_t lsdaOffset(uint32_t index) const { 356 return _addressSpace.get32( 357 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 358 index, lsdaOffset)); 359 } 360 361 private: 362 A &_addressSpace; 363 typename A::pint_t _addr; 364 }; 365 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 366 367 368 class _LIBUNWIND_HIDDEN AbstractUnwindCursor { 369 public: 370 virtual ~AbstractUnwindCursor() {} 371 virtual bool validReg(int) = 0; 372 virtual unw_word_t getReg(int) = 0; 373 virtual void setReg(int, unw_word_t) = 0; 374 virtual bool validFloatReg(int) = 0; 375 virtual unw_fpreg_t getFloatReg(int) = 0; 376 virtual void setFloatReg(int, unw_fpreg_t) = 0; 377 virtual int step() = 0; 378 virtual void getInfo(unw_proc_info_t *) = 0; 379 virtual void jumpto() = 0; 380 virtual bool isSignalFrame() = 0; 381 virtual bool getFunctionName(char *bf, size_t ln, unw_word_t *off) = 0; 382 virtual void setInfoBasedOnIPRegister(bool isReturnAddr = false) = 0; 383 virtual const char *getRegisterName(int num) = 0; 384 #if __arm__ 385 virtual void saveVFPAsX() = 0; 386 #endif 387 }; 388 389 390 /// UnwindCursor contains all state (including all register values) during 391 /// an unwind. This is normally stack allocated inside a unw_cursor_t. 392 template <typename A, typename R> 393 class UnwindCursor : public AbstractUnwindCursor{ 394 typedef typename A::pint_t pint_t; 395 public: 396 UnwindCursor(unw_context_t *context, A &as); 397 UnwindCursor(A &as, void *threadArg); 398 virtual ~UnwindCursor() {} 399 virtual bool validReg(int); 400 virtual unw_word_t getReg(int); 401 virtual void setReg(int, unw_word_t); 402 virtual bool validFloatReg(int); 403 virtual unw_fpreg_t getFloatReg(int); 404 virtual void setFloatReg(int, unw_fpreg_t); 405 virtual int step(); 406 virtual void getInfo(unw_proc_info_t *); 407 virtual void jumpto(); 408 virtual bool isSignalFrame(); 409 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off); 410 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false); 411 virtual const char *getRegisterName(int num); 412 #if __arm__ 413 virtual void saveVFPAsX(); 414 #endif 415 416 void operator delete(void *, size_t) {} 417 418 private: 419 420 #if LIBCXXABI_ARM_EHABI 421 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s); 422 #endif 423 424 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 425 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s, 426 uint32_t fdeSectionOffsetHint=0); 427 int stepWithDwarfFDE() { 428 return DwarfInstructions<A, R>::stepWithDwarf(_addressSpace, 429 (pint_t)this->getReg(UNW_REG_IP), 430 (pint_t)_info.unwind_info, 431 _registers); 432 } 433 #endif 434 435 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 436 bool getInfoFromCompactEncodingSection(pint_t pc, 437 const UnwindInfoSections §s); 438 int stepWithCompactEncoding() { 439 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 440 if ( compactSaysUseDwarf() ) 441 return stepWithDwarfFDE(); 442 #endif 443 R dummy; 444 return stepWithCompactEncoding(dummy); 445 } 446 447 int stepWithCompactEncoding(Registers_x86_64 &) { 448 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding( 449 _info.format, _info.start_ip, _addressSpace, _registers); 450 } 451 452 int stepWithCompactEncoding(Registers_x86 &) { 453 return CompactUnwinder_x86<A>::stepWithCompactEncoding( 454 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers); 455 } 456 457 int stepWithCompactEncoding(Registers_ppc &) { 458 return UNW_EINVAL; 459 } 460 461 int stepWithCompactEncoding(Registers_arm64 &) { 462 return CompactUnwinder_arm64<A>::stepWithCompactEncoding( 463 _info.format, _info.start_ip, _addressSpace, _registers); 464 } 465 466 bool compactSaysUseDwarf(uint32_t *offset=NULL) const { 467 R dummy; 468 return compactSaysUseDwarf(dummy, offset); 469 } 470 471 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const { 472 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) { 473 if (offset) 474 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET); 475 return true; 476 } 477 return false; 478 } 479 480 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const { 481 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) { 482 if (offset) 483 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET); 484 return true; 485 } 486 return false; 487 } 488 489 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const { 490 return true; 491 } 492 493 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const { 494 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) { 495 if (offset) 496 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET); 497 return true; 498 } 499 return false; 500 } 501 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 502 503 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 504 compact_unwind_encoding_t dwarfEncoding() const { 505 R dummy; 506 return dwarfEncoding(dummy); 507 } 508 509 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const { 510 return UNWIND_X86_64_MODE_DWARF; 511 } 512 513 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const { 514 return UNWIND_X86_MODE_DWARF; 515 } 516 517 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const { 518 return 0; 519 } 520 521 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const { 522 return UNWIND_ARM64_MODE_DWARF; 523 } 524 #endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 525 526 527 A &_addressSpace; 528 R _registers; 529 unw_proc_info_t _info; 530 bool _unwindInfoMissing; 531 bool _isSignalFrame; 532 }; 533 534 535 template <typename A, typename R> 536 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as) 537 : _addressSpace(as), _registers(context), _unwindInfoMissing(false), 538 _isSignalFrame(false) { 539 static_assert(sizeof(UnwindCursor<A, R>) < sizeof(unw_cursor_t), 540 "UnwindCursor<> does not fit in unw_cursor_t"); 541 memset(&_info, 0, sizeof(_info)); 542 } 543 544 template <typename A, typename R> 545 UnwindCursor<A, R>::UnwindCursor(A &as, void *) 546 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) { 547 memset(&_info, 0, sizeof(_info)); 548 // FIXME 549 // fill in _registers from thread arg 550 } 551 552 553 template <typename A, typename R> 554 bool UnwindCursor<A, R>::validReg(int regNum) { 555 return _registers.validRegister(regNum); 556 } 557 558 template <typename A, typename R> 559 unw_word_t UnwindCursor<A, R>::getReg(int regNum) { 560 return _registers.getRegister(regNum); 561 } 562 563 template <typename A, typename R> 564 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) { 565 _registers.setRegister(regNum, (typename A::pint_t)value); 566 } 567 568 template <typename A, typename R> 569 bool UnwindCursor<A, R>::validFloatReg(int regNum) { 570 return _registers.validFloatRegister(regNum); 571 } 572 573 template <typename A, typename R> 574 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) { 575 return _registers.getFloatRegister(regNum); 576 } 577 578 template <typename A, typename R> 579 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) { 580 _registers.setFloatRegister(regNum, value); 581 } 582 583 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() { 584 _registers.jumpto(); 585 } 586 587 #if __arm__ 588 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() { 589 _registers.saveVFPAsX(); 590 } 591 #endif 592 593 template <typename A, typename R> 594 const char *UnwindCursor<A, R>::getRegisterName(int regNum) { 595 return _registers.getRegisterName(regNum); 596 } 597 598 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() { 599 return _isSignalFrame; 600 } 601 602 #if LIBCXXABI_ARM_EHABI 603 struct EHABIIndexEntry { 604 uint32_t functionOffset; 605 uint32_t data; 606 }; 607 608 // Unable to unwind in the ARM index table (section 5 EHABI). 609 #define UNW_EXIDX_CANTUNWIND 0x1 610 611 static inline uint32_t signExtendPrel31(uint32_t data) { 612 return data | ((data & 0x40000000u) << 1); 613 } 614 615 extern "C" _Unwind_Reason_Code __aeabi_unwind_cpp_pr0( 616 _Unwind_State state, _Unwind_Control_Block *ucbp, _Unwind_Context *context); 617 extern "C" _Unwind_Reason_Code __aeabi_unwind_cpp_pr1( 618 _Unwind_State state, _Unwind_Control_Block *ucbp, _Unwind_Context *context); 619 extern "C" _Unwind_Reason_Code __aeabi_unwind_cpp_pr2( 620 _Unwind_State state, _Unwind_Control_Block *ucbp, _Unwind_Context *context); 621 622 template<typename A> 623 struct EHABISectionIterator { 624 typedef EHABISectionIterator _Self; 625 626 typedef std::random_access_iterator_tag iterator_category; 627 typedef typename A::pint_t value_type; 628 typedef typename A::pint_t* pointer; 629 typedef typename A::pint_t& reference; 630 typedef size_t size_type; 631 typedef size_t difference_type; 632 633 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) { 634 return _Self(addressSpace, sects, 0); 635 } 636 static _Self end(A& addressSpace, const UnwindInfoSections& sects) { 637 return _Self(addressSpace, sects, sects.arm_section_length); 638 } 639 640 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i) 641 : _addressSpace(&addressSpace), _sects(§s), _i(i) {} 642 643 _Self& operator++() { ++_i; return *this; } 644 _Self& operator+=(size_t a) { _i += a; return *this; } 645 _Self& operator--() { assert(_i > 0); --_i; return *this; } 646 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; } 647 648 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; } 649 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; } 650 651 size_t operator-(const _Self& other) { return _i - other._i; } 652 653 bool operator==(const _Self& other) const { 654 assert(_addressSpace == other._addressSpace); 655 assert(_sects == other._sects); 656 return _i == other._i; 657 } 658 659 typename A::pint_t operator*() const { return functionAddress(); } 660 661 typename A::pint_t functionAddress() const { 662 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 663 EHABIIndexEntry, _i, functionOffset); 664 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr)); 665 } 666 667 typename A::pint_t dataAddress() { 668 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 669 EHABIIndexEntry, _i, data); 670 return indexAddr; 671 } 672 673 private: 674 size_t _i; 675 A* _addressSpace; 676 const UnwindInfoSections* _sects; 677 }; 678 679 template <typename A, typename R> 680 bool UnwindCursor<A, R>::getInfoFromEHABISection( 681 pint_t pc, 682 const UnwindInfoSections §s) { 683 EHABISectionIterator<A> begin = 684 EHABISectionIterator<A>::begin(_addressSpace, sects); 685 EHABISectionIterator<A> end = 686 EHABISectionIterator<A>::end(_addressSpace, sects); 687 688 EHABISectionIterator<A> itNextPC = std::upper_bound(begin, end, pc); 689 if (itNextPC == begin || itNextPC == end) 690 return false; 691 EHABISectionIterator<A> itThisPC = itNextPC - 1; 692 693 pint_t thisPC = itThisPC.functionAddress(); 694 pint_t nextPC = itNextPC.functionAddress(); 695 pint_t indexDataAddr = itThisPC.dataAddress(); 696 697 if (indexDataAddr == 0) 698 return false; 699 700 uint32_t indexData = _addressSpace.get32(indexDataAddr); 701 if (indexData == UNW_EXIDX_CANTUNWIND) 702 return false; 703 704 // If the high bit is set, the exception handling table entry is inline inside 705 // the index table entry on the second word (aka |indexDataAddr|). Otherwise, 706 // the table points at an offset in the exception handling table (section 5 EHABI). 707 pint_t exceptionTableAddr; 708 uint32_t exceptionTableData; 709 bool isSingleWordEHT; 710 if (indexData & 0x80000000) { 711 exceptionTableAddr = indexDataAddr; 712 // TODO(ajwong): Should this data be 0? 713 exceptionTableData = indexData; 714 isSingleWordEHT = true; 715 } else { 716 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData); 717 exceptionTableData = _addressSpace.get32(exceptionTableAddr); 718 isSingleWordEHT = false; 719 } 720 721 // Now we know the 3 things: 722 // exceptionTableAddr -- exception handler table entry. 723 // exceptionTableData -- the data inside the first word of the eht entry. 724 // isSingleWordEHT -- whether the entry is in the index. 725 unw_word_t personalityRoutine = 0xbadf00d; 726 bool scope32 = false; 727 uintptr_t lsda = 0xbadf00d; 728 729 // If the high bit in the exception handling table entry is set, the entry is 730 // in compact form (section 6.3 EHABI). 731 if (exceptionTableData & 0x80000000) { 732 // Grab the index of the personality routine from the compact form. 733 int choice = (exceptionTableData & 0x0f000000) >> 24; 734 int extraWords = 0; 735 switch (choice) { 736 case 0: 737 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0; 738 extraWords = 0; 739 scope32 = false; 740 break; 741 case 1: 742 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1; 743 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 744 scope32 = false; 745 break; 746 case 2: 747 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2; 748 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 749 scope32 = true; 750 break; 751 default: 752 _LIBUNWIND_ABORT("unknown personality routine"); 753 return false; 754 } 755 756 if (isSingleWordEHT) { 757 if (extraWords != 0) { 758 _LIBUNWIND_ABORT("index inlined table detected but pr function " 759 "requires extra words"); 760 return false; 761 } 762 } 763 } else { 764 pint_t personalityAddr = 765 exceptionTableAddr + signExtendPrel31(exceptionTableData); 766 personalityRoutine = personalityAddr; 767 768 // ARM EHABI # 6.2, # 9.2 769 // 770 // +---- ehtp 771 // v 772 // +--------------------------------------+ 773 // | +--------+--------+--------+-------+ | 774 // | |0| prel31 to personalityRoutine | | 775 // | +--------+--------+--------+-------+ | 776 // | | N | unwind opcodes | | <-- UnwindData 777 // | +--------+--------+--------+-------+ | 778 // | | Word 2 unwind opcodes | | 779 // | +--------+--------+--------+-------+ | 780 // | ... | 781 // | +--------+--------+--------+-------+ | 782 // | | Word N unwind opcodes | | 783 // | +--------+--------+--------+-------+ | 784 // | | LSDA | | <-- lsda 785 // | | ... | | 786 // | +--------+--------+--------+-------+ | 787 // +--------------------------------------+ 788 789 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1; 790 uint32_t FirstDataWord = *UnwindData; 791 size_t N = ((FirstDataWord >> 24) & 0xff); 792 size_t NDataWords = N + 1; 793 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords); 794 } 795 796 _info.start_ip = thisPC; 797 _info.end_ip = nextPC; 798 _info.handler = personalityRoutine; 799 _info.unwind_info = exceptionTableAddr; 800 _info.lsda = lsda; 801 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0. 802 _info.flags = isSingleWordEHT ? 1 : 0 | scope32 ? 0x2 : 0; // Use enum? 803 804 return true; 805 } 806 #endif 807 808 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 809 template <typename A, typename R> 810 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc, 811 const UnwindInfoSections §s, 812 uint32_t fdeSectionOffsetHint) { 813 typename CFI_Parser<A>::FDE_Info fdeInfo; 814 typename CFI_Parser<A>::CIE_Info cieInfo; 815 bool foundFDE = false; 816 bool foundInCache = false; 817 // If compact encoding table gave offset into dwarf section, go directly there 818 if (fdeSectionOffsetHint != 0) { 819 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 820 (uint32_t)sects.dwarf_section_length, 821 sects.dwarf_section + fdeSectionOffsetHint, 822 &fdeInfo, &cieInfo); 823 } 824 #if _LIBUNWIND_SUPPORT_DWARF_INDEX 825 if (!foundFDE && (sects.dwarf_index_section != 0)) { 826 // Have eh_frame_hdr section which is index into dwarf section. 827 // TO DO: implement index search 828 } 829 #endif 830 if (!foundFDE) { 831 // otherwise, search cache of previously found FDEs. 832 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc); 833 if (cachedFDE != 0) { 834 foundFDE = 835 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 836 (uint32_t)sects.dwarf_section_length, 837 cachedFDE, &fdeInfo, &cieInfo); 838 foundInCache = foundFDE; 839 } 840 } 841 if (!foundFDE) { 842 // Still not found, do full scan of __eh_frame section. 843 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 844 (uint32_t)sects.dwarf_section_length, 0, 845 &fdeInfo, &cieInfo); 846 } 847 if (foundFDE) { 848 typename CFI_Parser<A>::PrologInfo prolog; 849 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc, 850 &prolog)) { 851 // Save off parsed FDE info 852 _info.start_ip = fdeInfo.pcStart; 853 _info.end_ip = fdeInfo.pcEnd; 854 _info.lsda = fdeInfo.lsda; 855 _info.handler = cieInfo.personality; 856 _info.gp = prolog.spExtraArgSize; 857 _info.flags = 0; 858 _info.format = dwarfEncoding(); 859 _info.unwind_info = fdeInfo.fdeStart; 860 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 861 _info.extra = (unw_word_t) sects.dso_base; 862 863 // Add to cache (to make next lookup faster) if we had no hint 864 // and there was no index. 865 if (!foundInCache && (fdeSectionOffsetHint == 0)) { 866 #if _LIBUNWIND_SUPPORT_DWARF_INDEX 867 if (sects.dwarf_index_section == 0) 868 #endif 869 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd, 870 fdeInfo.fdeStart); 871 } 872 return true; 873 } 874 } 875 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX\n", (uint64_t)pc); 876 return false; 877 } 878 #endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 879 880 881 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 882 template <typename A, typename R> 883 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc, 884 const UnwindInfoSections §s) { 885 const bool log = false; 886 if (log) 887 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n", 888 (uint64_t)pc, (uint64_t)sects.dso_base); 889 890 const UnwindSectionHeader<A> sectionHeader(_addressSpace, 891 sects.compact_unwind_section); 892 if (sectionHeader.version() != UNWIND_SECTION_VERSION) 893 return false; 894 895 // do a binary search of top level index to find page with unwind info 896 pint_t targetFunctionOffset = pc - sects.dso_base; 897 const UnwindSectionIndexArray<A> topIndex(_addressSpace, 898 sects.compact_unwind_section 899 + sectionHeader.indexSectionOffset()); 900 uint32_t low = 0; 901 uint32_t high = sectionHeader.indexCount(); 902 uint32_t last = high - 1; 903 while (low < high) { 904 uint32_t mid = (low + high) / 2; 905 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n", 906 //mid, low, high, topIndex.functionOffset(mid)); 907 if (topIndex.functionOffset(mid) <= targetFunctionOffset) { 908 if ((mid == last) || 909 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) { 910 low = mid; 911 break; 912 } else { 913 low = mid + 1; 914 } 915 } else { 916 high = mid; 917 } 918 } 919 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low); 920 const uint32_t firstLevelNextPageFunctionOffset = 921 topIndex.functionOffset(low + 1); 922 const pint_t secondLevelAddr = 923 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low); 924 const pint_t lsdaArrayStartAddr = 925 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low); 926 const pint_t lsdaArrayEndAddr = 927 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1); 928 if (log) 929 fprintf(stderr, "\tfirst level search for result index=%d " 930 "to secondLevelAddr=0x%llX\n", 931 low, (uint64_t) secondLevelAddr); 932 // do a binary search of second level page index 933 uint32_t encoding = 0; 934 pint_t funcStart = 0; 935 pint_t funcEnd = 0; 936 pint_t lsda = 0; 937 pint_t personality = 0; 938 uint32_t pageKind = _addressSpace.get32(secondLevelAddr); 939 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) { 940 // regular page 941 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace, 942 secondLevelAddr); 943 UnwindSectionRegularArray<A> pageIndex( 944 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 945 // binary search looks for entry with e where index[e].offset <= pc < 946 // index[e+1].offset 947 if (log) 948 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in " 949 "regular page starting at secondLevelAddr=0x%llX\n", 950 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr); 951 low = 0; 952 high = pageHeader.entryCount(); 953 while (low < high) { 954 uint32_t mid = (low + high) / 2; 955 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) { 956 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) { 957 // at end of table 958 low = mid; 959 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 960 break; 961 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) { 962 // next is too big, so we found it 963 low = mid; 964 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base; 965 break; 966 } else { 967 low = mid + 1; 968 } 969 } else { 970 high = mid; 971 } 972 } 973 encoding = pageIndex.encoding(low); 974 funcStart = pageIndex.functionOffset(low) + sects.dso_base; 975 if (pc < funcStart) { 976 if (log) 977 fprintf( 978 stderr, 979 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 980 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 981 return false; 982 } 983 if (pc > funcEnd) { 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 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) { 992 // compressed page 993 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace, 994 secondLevelAddr); 995 UnwindSectionCompressedArray<A> pageIndex( 996 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 997 const uint32_t targetFunctionPageOffset = 998 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset); 999 // binary search looks for entry with e where index[e].offset <= pc < 1000 // index[e+1].offset 1001 if (log) 1002 fprintf(stderr, "\tbinary search of compressed page starting at " 1003 "secondLevelAddr=0x%llX\n", 1004 (uint64_t) secondLevelAddr); 1005 low = 0; 1006 last = pageHeader.entryCount() - 1; 1007 high = pageHeader.entryCount(); 1008 while (low < high) { 1009 uint32_t mid = (low + high) / 2; 1010 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) { 1011 if ((mid == last) || 1012 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) { 1013 low = mid; 1014 break; 1015 } else { 1016 low = mid + 1; 1017 } 1018 } else { 1019 high = mid; 1020 } 1021 } 1022 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset 1023 + sects.dso_base; 1024 if (low < last) 1025 funcEnd = 1026 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset 1027 + sects.dso_base; 1028 else 1029 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 1030 if (pc < funcStart) { 1031 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1032 "level compressed unwind table. funcStart=0x%llX\n", 1033 (uint64_t) pc, (uint64_t) funcStart); 1034 return false; 1035 } 1036 if (pc > funcEnd) { 1037 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1038 "level compressed unwind table. funcEnd=0x%llX\n", 1039 (uint64_t) pc, (uint64_t) funcEnd); 1040 return false; 1041 } 1042 uint16_t encodingIndex = pageIndex.encodingIndex(low); 1043 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) { 1044 // encoding is in common table in section header 1045 encoding = _addressSpace.get32( 1046 sects.compact_unwind_section + 1047 sectionHeader.commonEncodingsArraySectionOffset() + 1048 encodingIndex * sizeof(uint32_t)); 1049 } else { 1050 // encoding is in page specific table 1051 uint16_t pageEncodingIndex = 1052 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount(); 1053 encoding = _addressSpace.get32(secondLevelAddr + 1054 pageHeader.encodingsPageOffset() + 1055 pageEncodingIndex * sizeof(uint32_t)); 1056 } 1057 } else { 1058 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info at 0x%0llX bad second " 1059 "level page\n", 1060 (uint64_t) sects.compact_unwind_section); 1061 return false; 1062 } 1063 1064 // look up LSDA, if encoding says function has one 1065 if (encoding & UNWIND_HAS_LSDA) { 1066 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr); 1067 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base); 1068 low = 0; 1069 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) / 1070 sizeof(unwind_info_section_header_lsda_index_entry); 1071 // binary search looks for entry with exact match for functionOffset 1072 if (log) 1073 fprintf(stderr, 1074 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n", 1075 funcStartOffset); 1076 while (low < high) { 1077 uint32_t mid = (low + high) / 2; 1078 if (lsdaIndex.functionOffset(mid) == funcStartOffset) { 1079 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base; 1080 break; 1081 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) { 1082 low = mid + 1; 1083 } else { 1084 high = mid; 1085 } 1086 } 1087 if (lsda == 0) { 1088 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for " 1089 "pc=0x%0llX, but lsda table has no entry\n", 1090 encoding, (uint64_t) pc); 1091 return false; 1092 } 1093 } 1094 1095 // extact personality routine, if encoding says function has one 1096 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >> 1097 (__builtin_ctz(UNWIND_PERSONALITY_MASK)); 1098 if (personalityIndex != 0) { 1099 --personalityIndex; // change 1-based to zero-based index 1100 if (personalityIndex > sectionHeader.personalityArrayCount()) { 1101 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, " 1102 "but personality table has only %d entires\n", 1103 encoding, personalityIndex, 1104 sectionHeader.personalityArrayCount()); 1105 return false; 1106 } 1107 int32_t personalityDelta = (int32_t)_addressSpace.get32( 1108 sects.compact_unwind_section + 1109 sectionHeader.personalityArraySectionOffset() + 1110 personalityIndex * sizeof(uint32_t)); 1111 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta; 1112 personality = _addressSpace.getP(personalityPointer); 1113 if (log) 1114 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1115 "personalityDelta=0x%08X, personality=0x%08llX\n", 1116 (uint64_t) pc, personalityDelta, (uint64_t) personality); 1117 } 1118 1119 if (log) 1120 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1121 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n", 1122 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart); 1123 _info.start_ip = funcStart; 1124 _info.end_ip = funcEnd; 1125 _info.lsda = lsda; 1126 _info.handler = personality; 1127 _info.gp = 0; 1128 _info.flags = 0; 1129 _info.format = encoding; 1130 _info.unwind_info = 0; 1131 _info.unwind_info_size = 0; 1132 _info.extra = sects.dso_base; 1133 return true; 1134 } 1135 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1136 1137 1138 template <typename A, typename R> 1139 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) { 1140 pint_t pc = (pint_t)this->getReg(UNW_REG_IP); 1141 #if LIBCXXABI_ARM_EHABI 1142 // Remove the thumb bit so the IP represents the actual instruction address. 1143 // This matches the behaviour of _Unwind_GetIP on arm. 1144 pc &= (pint_t)~0x1; 1145 #endif 1146 1147 // If the last line of a function is a "throw" the compiler sometimes 1148 // emits no instructions after the call to __cxa_throw. This means 1149 // the return address is actually the start of the next function. 1150 // To disambiguate this, back up the pc when we know it is a return 1151 // address. 1152 if (isReturnAddress) 1153 --pc; 1154 1155 // Ask address space object to find unwind sections for this pc. 1156 UnwindInfoSections sects; 1157 if (_addressSpace.findUnwindSections(pc, sects)) { 1158 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1159 // If there is a compact unwind encoding table, look there first. 1160 if (sects.compact_unwind_section != 0) { 1161 if (this->getInfoFromCompactEncodingSection(pc, sects)) { 1162 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1163 // Found info in table, done unless encoding says to use dwarf. 1164 uint32_t dwarfOffset; 1165 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) { 1166 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) { 1167 // found info in dwarf, done 1168 return; 1169 } 1170 } 1171 #endif 1172 // If unwind table has entry, but entry says there is no unwind info, 1173 // record that we have no unwind info. 1174 if (_info.format == 0) 1175 _unwindInfoMissing = true; 1176 return; 1177 } 1178 } 1179 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1180 1181 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1182 // If there is dwarf unwind info, look there next. 1183 if (sects.dwarf_section != 0) { 1184 if (this->getInfoFromDwarfSection(pc, sects)) { 1185 // found info in dwarf, done 1186 return; 1187 } 1188 } 1189 #endif 1190 1191 #if LIBCXXABI_ARM_EHABI 1192 // If there is ARM EHABI unwind info, look there next. 1193 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects)) 1194 return; 1195 #endif 1196 } 1197 1198 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1199 // There is no static unwind info for this pc. Look to see if an FDE was 1200 // dynamically registered for it. 1201 pint_t cachedFDE = DwarfFDECache<A>::findFDE(0, pc); 1202 if (cachedFDE != 0) { 1203 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1204 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1205 const char *msg = CFI_Parser<A>::decodeFDE(_addressSpace, 1206 cachedFDE, &fdeInfo, &cieInfo); 1207 if (msg == NULL) { 1208 typename CFI_Parser<A>::PrologInfo prolog; 1209 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, 1210 pc, &prolog)) { 1211 // save off parsed FDE info 1212 _info.start_ip = fdeInfo.pcStart; 1213 _info.end_ip = fdeInfo.pcEnd; 1214 _info.lsda = fdeInfo.lsda; 1215 _info.handler = cieInfo.personality; 1216 _info.gp = prolog.spExtraArgSize; 1217 // Some frameless functions need SP 1218 // altered when resuming in function. 1219 _info.flags = 0; 1220 _info.format = dwarfEncoding(); 1221 _info.unwind_info = fdeInfo.fdeStart; 1222 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1223 _info.extra = 0; 1224 return; 1225 } 1226 } 1227 } 1228 1229 // Lastly, ask AddressSpace object about platform specific ways to locate 1230 // other FDEs. 1231 pint_t fde; 1232 if (_addressSpace.findOtherFDE(pc, fde)) { 1233 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1234 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1235 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) { 1236 // Double check this FDE is for a function that includes the pc. 1237 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) { 1238 typename CFI_Parser<A>::PrologInfo prolog; 1239 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, 1240 cieInfo, pc, &prolog)) { 1241 // save off parsed FDE info 1242 _info.start_ip = fdeInfo.pcStart; 1243 _info.end_ip = fdeInfo.pcEnd; 1244 _info.lsda = fdeInfo.lsda; 1245 _info.handler = cieInfo.personality; 1246 _info.gp = prolog.spExtraArgSize; 1247 _info.flags = 0; 1248 _info.format = dwarfEncoding(); 1249 _info.unwind_info = fdeInfo.fdeStart; 1250 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1251 _info.extra = 0; 1252 return; 1253 } 1254 } 1255 } 1256 } 1257 #endif // #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1258 1259 // no unwind info, flag that we can't reliably unwind 1260 _unwindInfoMissing = true; 1261 } 1262 1263 template <typename A, typename R> 1264 int UnwindCursor<A, R>::step() { 1265 // Bottom of stack is defined is when unwind info cannot be found. 1266 if (_unwindInfoMissing) 1267 return UNW_STEP_END; 1268 1269 // Use unwinding info to modify register set as if function returned. 1270 int result; 1271 #if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1272 result = this->stepWithCompactEncoding(); 1273 #elif _LIBUNWIND_SUPPORT_DWARF_UNWIND 1274 result = this->stepWithDwarfFDE(); 1275 #elif LIBCXXABI_ARM_EHABI 1276 result = UNW_STEP_SUCCESS; 1277 #else 1278 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \ 1279 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \ 1280 LIBCXXABI_ARM_EHABI 1281 #endif 1282 1283 // update info based on new PC 1284 if (result == UNW_STEP_SUCCESS) { 1285 this->setInfoBasedOnIPRegister(true); 1286 if (_unwindInfoMissing) 1287 return UNW_STEP_END; 1288 if (_info.gp) 1289 setReg(UNW_REG_SP, getReg(UNW_REG_SP) + _info.gp); 1290 } 1291 1292 return result; 1293 } 1294 1295 template <typename A, typename R> 1296 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) { 1297 *info = _info; 1298 } 1299 1300 template <typename A, typename R> 1301 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen, 1302 unw_word_t *offset) { 1303 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP), 1304 buf, bufLen, offset); 1305 } 1306 1307 }; // namespace libunwind 1308 1309 #endif // __UNWINDCURSOR_HPP__ 1310