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 37namespace libunwind { 38 39#if _LIBUNWIND_SUPPORT_DWARF_UNWIND 40/// Cache of recently found FDEs. 41template <typename A> 42class _LIBUNWIND_HIDDEN DwarfFDECache { 43 typedef typename A::pint_t pint_t; 44public: 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 52private: 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 75template <typename A> 76typename DwarfFDECache<A>::entry * 77DwarfFDECache<A>::_buffer = _initialBuffer; 78 79template <typename A> 80typename DwarfFDECache<A>::entry * 81DwarfFDECache<A>::_bufferUsed = _initialBuffer; 82 83template <typename A> 84typename DwarfFDECache<A>::entry * 85DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64]; 86 87template <typename A> 88typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64]; 89 90template <typename A> 91pthread_rwlock_t DwarfFDECache<A>::_lock = PTHREAD_RWLOCK_INITIALIZER; 92 93#ifdef __APPLE__ 94template <typename A> 95bool DwarfFDECache<A>::_registeredForDyldUnloads = false; 96#endif 97 98template <typename A> 99typename 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 114template <typename A> 115void 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 144template <typename A> 145void 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__ 160template <typename A> 161void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) { 162 removeAllIn((pint_t) mh); 163} 164#endif 165 166template <typename A> 167void 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 181template <typename A> class UnwindSectionHeader { 182public: 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 216private: 217 A &_addressSpace; 218 typename A::pint_t _addr; 219}; 220 221template <typename A> class UnwindSectionIndexArray { 222public: 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 242private: 243 A &_addressSpace; 244 typename A::pint_t _addr; 245}; 246 247template <typename A> class UnwindSectionRegularPageHeader { 248public: 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 267private: 268 A &_addressSpace; 269 typename A::pint_t _addr; 270}; 271 272template <typename A> class UnwindSectionRegularArray { 273public: 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 288private: 289 A &_addressSpace; 290 typename A::pint_t _addr; 291}; 292 293template <typename A> class UnwindSectionCompressedPageHeader { 294public: 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 324private: 325 A &_addressSpace; 326 typename A::pint_t _addr; 327}; 328 329template <typename A> class UnwindSectionCompressedArray { 330public: 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 343private: 344 A &_addressSpace; 345 typename A::pint_t _addr; 346}; 347 348template <typename A> class UnwindSectionLsdaArray { 349public: 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 364private: 365 A &_addressSpace; 366 typename A::pint_t _addr; 367}; 368#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 369 370class _LIBUNWIND_HIDDEN AbstractUnwindCursor { 371public: 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. 415template <typename A, typename R> 416class UnwindCursor : public AbstractUnwindCursor{ 417 typedef typename A::pint_t pint_t; 418public: 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 439private: 440 441#if _LIBUNWIND_ARM_EHABI 442 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s); 443 444 int stepWithEHABI() { 445 size_t len = 0; 446 size_t off = 0; 447 // FIXME: Calling decode_eht_entry() here is violating the libunwind 448 // abstraction layer. 449 const uint32_t *ehtp = 450 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info), 451 &off, &len); 452 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) != 453 _URC_CONTINUE_UNWIND) 454 return UNW_STEP_END; 455 return UNW_STEP_SUCCESS; 456 } 457#endif 458 459#if _LIBUNWIND_SUPPORT_DWARF_UNWIND 460 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s, 461 uint32_t fdeSectionOffsetHint=0); 462 int stepWithDwarfFDE() { 463 return DwarfInstructions<A, R>::stepWithDwarf(_addressSpace, 464 (pint_t)this->getReg(UNW_REG_IP), 465 (pint_t)_info.unwind_info, 466 _registers); 467 } 468#endif 469 470#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 471 bool getInfoFromCompactEncodingSection(pint_t pc, 472 const UnwindInfoSections §s); 473 int stepWithCompactEncoding() { 474 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 475 if ( compactSaysUseDwarf() ) 476 return stepWithDwarfFDE(); 477 #endif 478 R dummy; 479 return stepWithCompactEncoding(dummy); 480 } 481 482 int stepWithCompactEncoding(Registers_x86_64 &) { 483 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding( 484 _info.format, _info.start_ip, _addressSpace, _registers); 485 } 486 487 int stepWithCompactEncoding(Registers_x86 &) { 488 return CompactUnwinder_x86<A>::stepWithCompactEncoding( 489 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers); 490 } 491 492 int stepWithCompactEncoding(Registers_ppc &) { 493 return UNW_EINVAL; 494 } 495 496 int stepWithCompactEncoding(Registers_arm64 &) { 497 return CompactUnwinder_arm64<A>::stepWithCompactEncoding( 498 _info.format, _info.start_ip, _addressSpace, _registers); 499 } 500 501 bool compactSaysUseDwarf(uint32_t *offset=NULL) const { 502 R dummy; 503 return compactSaysUseDwarf(dummy, offset); 504 } 505 506 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const { 507 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) { 508 if (offset) 509 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET); 510 return true; 511 } 512 return false; 513 } 514 515 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const { 516 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) { 517 if (offset) 518 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET); 519 return true; 520 } 521 return false; 522 } 523 524 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const { 525 return true; 526 } 527 528 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const { 529 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) { 530 if (offset) 531 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET); 532 return true; 533 } 534 return false; 535 } 536#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 537 538#if _LIBUNWIND_SUPPORT_DWARF_UNWIND 539 compact_unwind_encoding_t dwarfEncoding() const { 540 R dummy; 541 return dwarfEncoding(dummy); 542 } 543 544 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const { 545 return UNWIND_X86_64_MODE_DWARF; 546 } 547 548 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const { 549 return UNWIND_X86_MODE_DWARF; 550 } 551 552 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const { 553 return 0; 554 } 555 556 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const { 557 return UNWIND_ARM64_MODE_DWARF; 558 } 559#endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 560 561 562 A &_addressSpace; 563 R _registers; 564 unw_proc_info_t _info; 565 bool _unwindInfoMissing; 566 bool _isSignalFrame; 567}; 568 569 570template <typename A, typename R> 571UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as) 572 : _addressSpace(as), _registers(context), _unwindInfoMissing(false), 573 _isSignalFrame(false) { 574 static_assert(sizeof(UnwindCursor<A, R>) < sizeof(unw_cursor_t), 575 "UnwindCursor<> does not fit in unw_cursor_t"); 576 memset(&_info, 0, sizeof(_info)); 577} 578 579template <typename A, typename R> 580UnwindCursor<A, R>::UnwindCursor(A &as, void *) 581 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) { 582 memset(&_info, 0, sizeof(_info)); 583 // FIXME 584 // fill in _registers from thread arg 585} 586 587 588template <typename A, typename R> 589bool UnwindCursor<A, R>::validReg(int regNum) { 590 return _registers.validRegister(regNum); 591} 592 593template <typename A, typename R> 594unw_word_t UnwindCursor<A, R>::getReg(int regNum) { 595 return _registers.getRegister(regNum); 596} 597 598template <typename A, typename R> 599void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) { 600 _registers.setRegister(regNum, (typename A::pint_t)value); 601} 602 603template <typename A, typename R> 604bool UnwindCursor<A, R>::validFloatReg(int regNum) { 605 return _registers.validFloatRegister(regNum); 606} 607 608template <typename A, typename R> 609unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) { 610 return _registers.getFloatRegister(regNum); 611} 612 613template <typename A, typename R> 614void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) { 615 _registers.setFloatRegister(regNum, value); 616} 617 618template <typename A, typename R> void UnwindCursor<A, R>::jumpto() { 619 _registers.jumpto(); 620} 621 622#ifdef __arm__ 623template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() { 624 _registers.saveVFPAsX(); 625} 626#endif 627 628template <typename A, typename R> 629const char *UnwindCursor<A, R>::getRegisterName(int regNum) { 630 return _registers.getRegisterName(regNum); 631} 632 633template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() { 634 return _isSignalFrame; 635} 636 637#if _LIBUNWIND_ARM_EHABI 638struct EHABIIndexEntry { 639 uint32_t functionOffset; 640 uint32_t data; 641}; 642 643template<typename A> 644struct EHABISectionIterator { 645 typedef EHABISectionIterator _Self; 646 647 typedef std::random_access_iterator_tag iterator_category; 648 typedef typename A::pint_t value_type; 649 typedef typename A::pint_t* pointer; 650 typedef typename A::pint_t& reference; 651 typedef size_t size_type; 652 typedef size_t difference_type; 653 654 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) { 655 return _Self(addressSpace, sects, 0); 656 } 657 static _Self end(A& addressSpace, const UnwindInfoSections& sects) { 658 return _Self(addressSpace, sects, sects.arm_section_length); 659 } 660 661 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i) 662 : _i(i), _addressSpace(&addressSpace), _sects(§s) {} 663 664 _Self& operator++() { ++_i; return *this; } 665 _Self& operator+=(size_t a) { _i += a; return *this; } 666 _Self& operator--() { assert(_i > 0); --_i; return *this; } 667 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; } 668 669 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; } 670 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; } 671 672 size_t operator-(const _Self& other) { return _i - other._i; } 673 674 bool operator==(const _Self& other) const { 675 assert(_addressSpace == other._addressSpace); 676 assert(_sects == other._sects); 677 return _i == other._i; 678 } 679 680 typename A::pint_t operator*() const { return functionAddress(); } 681 682 typename A::pint_t functionAddress() const { 683 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 684 EHABIIndexEntry, _i, functionOffset); 685 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr)); 686 } 687 688 typename A::pint_t dataAddress() { 689 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 690 EHABIIndexEntry, _i, data); 691 return indexAddr; 692 } 693 694 private: 695 size_t _i; 696 A* _addressSpace; 697 const UnwindInfoSections* _sects; 698}; 699 700template <typename A, typename R> 701bool UnwindCursor<A, R>::getInfoFromEHABISection( 702 pint_t pc, 703 const UnwindInfoSections §s) { 704 EHABISectionIterator<A> begin = 705 EHABISectionIterator<A>::begin(_addressSpace, sects); 706 EHABISectionIterator<A> end = 707 EHABISectionIterator<A>::end(_addressSpace, sects); 708 709 EHABISectionIterator<A> itNextPC = std::upper_bound(begin, end, pc); 710 if (itNextPC == begin || itNextPC == end) 711 return false; 712 EHABISectionIterator<A> itThisPC = itNextPC - 1; 713 714 pint_t thisPC = itThisPC.functionAddress(); 715 pint_t nextPC = itNextPC.functionAddress(); 716 pint_t indexDataAddr = itThisPC.dataAddress(); 717 718 if (indexDataAddr == 0) 719 return false; 720 721 uint32_t indexData = _addressSpace.get32(indexDataAddr); 722 if (indexData == UNW_EXIDX_CANTUNWIND) 723 return false; 724 725 // If the high bit is set, the exception handling table entry is inline inside 726 // the index table entry on the second word (aka |indexDataAddr|). Otherwise, 727 // the table points at an offset in the exception handling table (section 5 EHABI). 728 pint_t exceptionTableAddr; 729 uint32_t exceptionTableData; 730 bool isSingleWordEHT; 731 if (indexData & 0x80000000) { 732 exceptionTableAddr = indexDataAddr; 733 // TODO(ajwong): Should this data be 0? 734 exceptionTableData = indexData; 735 isSingleWordEHT = true; 736 } else { 737 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData); 738 exceptionTableData = _addressSpace.get32(exceptionTableAddr); 739 isSingleWordEHT = false; 740 } 741 742 // Now we know the 3 things: 743 // exceptionTableAddr -- exception handler table entry. 744 // exceptionTableData -- the data inside the first word of the eht entry. 745 // isSingleWordEHT -- whether the entry is in the index. 746 unw_word_t personalityRoutine = 0xbadf00d; 747 bool scope32 = false; 748 uintptr_t lsda; 749 750 // If the high bit in the exception handling table entry is set, the entry is 751 // in compact form (section 6.3 EHABI). 752 if (exceptionTableData & 0x80000000) { 753 // Grab the index of the personality routine from the compact form. 754 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24; 755 uint32_t extraWords = 0; 756 switch (choice) { 757 case 0: 758 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0; 759 extraWords = 0; 760 scope32 = false; 761 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4); 762 break; 763 case 1: 764 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1; 765 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 766 scope32 = false; 767 lsda = exceptionTableAddr + (extraWords + 1) * 4; 768 break; 769 case 2: 770 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2; 771 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 772 scope32 = true; 773 lsda = exceptionTableAddr + (extraWords + 1) * 4; 774 break; 775 default: 776 _LIBUNWIND_ABORT("unknown personality routine"); 777 return false; 778 } 779 780 if (isSingleWordEHT) { 781 if (extraWords != 0) { 782 _LIBUNWIND_ABORT("index inlined table detected but pr function " 783 "requires extra words"); 784 return false; 785 } 786 } 787 } else { 788 pint_t personalityAddr = 789 exceptionTableAddr + signExtendPrel31(exceptionTableData); 790 personalityRoutine = personalityAddr; 791 792 // ARM EHABI # 6.2, # 9.2 793 // 794 // +---- ehtp 795 // v 796 // +--------------------------------------+ 797 // | +--------+--------+--------+-------+ | 798 // | |0| prel31 to personalityRoutine | | 799 // | +--------+--------+--------+-------+ | 800 // | | N | unwind opcodes | | <-- UnwindData 801 // | +--------+--------+--------+-------+ | 802 // | | Word 2 unwind opcodes | | 803 // | +--------+--------+--------+-------+ | 804 // | ... | 805 // | +--------+--------+--------+-------+ | 806 // | | Word N unwind opcodes | | 807 // | +--------+--------+--------+-------+ | 808 // | | LSDA | | <-- lsda 809 // | | ... | | 810 // | +--------+--------+--------+-------+ | 811 // +--------------------------------------+ 812 813 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1; 814 uint32_t FirstDataWord = *UnwindData; 815 size_t N = ((FirstDataWord >> 24) & 0xff); 816 size_t NDataWords = N + 1; 817 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords); 818 } 819 820 _info.start_ip = thisPC; 821 _info.end_ip = nextPC; 822 _info.handler = personalityRoutine; 823 _info.unwind_info = exceptionTableAddr; 824 _info.lsda = lsda; 825 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0. 826 _info.flags = isSingleWordEHT ? 1 : 0 | scope32 ? 0x2 : 0; // Use enum? 827 828 return true; 829} 830#endif 831 832#if _LIBUNWIND_SUPPORT_DWARF_UNWIND 833template <typename A, typename R> 834bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc, 835 const UnwindInfoSections §s, 836 uint32_t fdeSectionOffsetHint) { 837 typename CFI_Parser<A>::FDE_Info fdeInfo; 838 typename CFI_Parser<A>::CIE_Info cieInfo; 839 bool foundFDE = false; 840 bool foundInCache = false; 841 // If compact encoding table gave offset into dwarf section, go directly there 842 if (fdeSectionOffsetHint != 0) { 843 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 844 (uint32_t)sects.dwarf_section_length, 845 sects.dwarf_section + fdeSectionOffsetHint, 846 &fdeInfo, &cieInfo); 847 } 848#if _LIBUNWIND_SUPPORT_DWARF_INDEX 849 if (!foundFDE && (sects.dwarf_index_section != 0)) { 850 foundFDE = EHHeaderParser<A>::findFDE( 851 _addressSpace, pc, sects.dwarf_index_section, 852 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo); 853 } 854#endif 855 if (!foundFDE) { 856 // otherwise, search cache of previously found FDEs. 857 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc); 858 if (cachedFDE != 0) { 859 foundFDE = 860 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 861 (uint32_t)sects.dwarf_section_length, 862 cachedFDE, &fdeInfo, &cieInfo); 863 foundInCache = foundFDE; 864 } 865 } 866 if (!foundFDE) { 867 // Still not found, do full scan of __eh_frame section. 868 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 869 (uint32_t)sects.dwarf_section_length, 0, 870 &fdeInfo, &cieInfo); 871 } 872 if (foundFDE) { 873 typename CFI_Parser<A>::PrologInfo prolog; 874 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc, 875 &prolog)) { 876 // Save off parsed FDE info 877 _info.start_ip = fdeInfo.pcStart; 878 _info.end_ip = fdeInfo.pcEnd; 879 _info.lsda = fdeInfo.lsda; 880 _info.handler = cieInfo.personality; 881 _info.gp = prolog.spExtraArgSize; 882 _info.flags = 0; 883 _info.format = dwarfEncoding(); 884 _info.unwind_info = fdeInfo.fdeStart; 885 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 886 _info.extra = (unw_word_t) sects.dso_base; 887 888 // Add to cache (to make next lookup faster) if we had no hint 889 // and there was no index. 890 if (!foundInCache && (fdeSectionOffsetHint == 0)) { 891 #if _LIBUNWIND_SUPPORT_DWARF_INDEX 892 if (sects.dwarf_index_section == 0) 893 #endif 894 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd, 895 fdeInfo.fdeStart); 896 } 897 return true; 898 } 899 } 900 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX\n", (uint64_t)pc); 901 return false; 902} 903#endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND 904 905 906#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 907template <typename A, typename R> 908bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc, 909 const UnwindInfoSections §s) { 910 const bool log = false; 911 if (log) 912 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n", 913 (uint64_t)pc, (uint64_t)sects.dso_base); 914 915 const UnwindSectionHeader<A> sectionHeader(_addressSpace, 916 sects.compact_unwind_section); 917 if (sectionHeader.version() != UNWIND_SECTION_VERSION) 918 return false; 919 920 // do a binary search of top level index to find page with unwind info 921 pint_t targetFunctionOffset = pc - sects.dso_base; 922 const UnwindSectionIndexArray<A> topIndex(_addressSpace, 923 sects.compact_unwind_section 924 + sectionHeader.indexSectionOffset()); 925 uint32_t low = 0; 926 uint32_t high = sectionHeader.indexCount(); 927 uint32_t last = high - 1; 928 while (low < high) { 929 uint32_t mid = (low + high) / 2; 930 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n", 931 //mid, low, high, topIndex.functionOffset(mid)); 932 if (topIndex.functionOffset(mid) <= targetFunctionOffset) { 933 if ((mid == last) || 934 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) { 935 low = mid; 936 break; 937 } else { 938 low = mid + 1; 939 } 940 } else { 941 high = mid; 942 } 943 } 944 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low); 945 const uint32_t firstLevelNextPageFunctionOffset = 946 topIndex.functionOffset(low + 1); 947 const pint_t secondLevelAddr = 948 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low); 949 const pint_t lsdaArrayStartAddr = 950 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low); 951 const pint_t lsdaArrayEndAddr = 952 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1); 953 if (log) 954 fprintf(stderr, "\tfirst level search for result index=%d " 955 "to secondLevelAddr=0x%llX\n", 956 low, (uint64_t) secondLevelAddr); 957 // do a binary search of second level page index 958 uint32_t encoding = 0; 959 pint_t funcStart = 0; 960 pint_t funcEnd = 0; 961 pint_t lsda = 0; 962 pint_t personality = 0; 963 uint32_t pageKind = _addressSpace.get32(secondLevelAddr); 964 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) { 965 // regular page 966 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace, 967 secondLevelAddr); 968 UnwindSectionRegularArray<A> pageIndex( 969 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 970 // binary search looks for entry with e where index[e].offset <= pc < 971 // index[e+1].offset 972 if (log) 973 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in " 974 "regular page starting at secondLevelAddr=0x%llX\n", 975 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr); 976 low = 0; 977 high = pageHeader.entryCount(); 978 while (low < high) { 979 uint32_t mid = (low + high) / 2; 980 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) { 981 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) { 982 // at end of table 983 low = mid; 984 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 985 break; 986 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) { 987 // next is too big, so we found it 988 low = mid; 989 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base; 990 break; 991 } else { 992 low = mid + 1; 993 } 994 } else { 995 high = mid; 996 } 997 } 998 encoding = pageIndex.encoding(low); 999 funcStart = pageIndex.functionOffset(low) + sects.dso_base; 1000 if (pc < funcStart) { 1001 if (log) 1002 fprintf( 1003 stderr, 1004 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 1005 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 1006 return false; 1007 } 1008 if (pc > funcEnd) { 1009 if (log) 1010 fprintf( 1011 stderr, 1012 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 1013 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 1014 return false; 1015 } 1016 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) { 1017 // compressed page 1018 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace, 1019 secondLevelAddr); 1020 UnwindSectionCompressedArray<A> pageIndex( 1021 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 1022 const uint32_t targetFunctionPageOffset = 1023 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset); 1024 // binary search looks for entry with e where index[e].offset <= pc < 1025 // index[e+1].offset 1026 if (log) 1027 fprintf(stderr, "\tbinary search of compressed page starting at " 1028 "secondLevelAddr=0x%llX\n", 1029 (uint64_t) secondLevelAddr); 1030 low = 0; 1031 last = pageHeader.entryCount() - 1; 1032 high = pageHeader.entryCount(); 1033 while (low < high) { 1034 uint32_t mid = (low + high) / 2; 1035 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) { 1036 if ((mid == last) || 1037 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) { 1038 low = mid; 1039 break; 1040 } else { 1041 low = mid + 1; 1042 } 1043 } else { 1044 high = mid; 1045 } 1046 } 1047 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset 1048 + sects.dso_base; 1049 if (low < last) 1050 funcEnd = 1051 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset 1052 + sects.dso_base; 1053 else 1054 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 1055 if (pc < funcStart) { 1056 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1057 "level compressed unwind table. funcStart=0x%llX\n", 1058 (uint64_t) pc, (uint64_t) funcStart); 1059 return false; 1060 } 1061 if (pc > funcEnd) { 1062 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1063 "level compressed unwind table. funcEnd=0x%llX\n", 1064 (uint64_t) pc, (uint64_t) funcEnd); 1065 return false; 1066 } 1067 uint16_t encodingIndex = pageIndex.encodingIndex(low); 1068 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) { 1069 // encoding is in common table in section header 1070 encoding = _addressSpace.get32( 1071 sects.compact_unwind_section + 1072 sectionHeader.commonEncodingsArraySectionOffset() + 1073 encodingIndex * sizeof(uint32_t)); 1074 } else { 1075 // encoding is in page specific table 1076 uint16_t pageEncodingIndex = 1077 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount(); 1078 encoding = _addressSpace.get32(secondLevelAddr + 1079 pageHeader.encodingsPageOffset() + 1080 pageEncodingIndex * sizeof(uint32_t)); 1081 } 1082 } else { 1083 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info at 0x%0llX bad second " 1084 "level page\n", 1085 (uint64_t) sects.compact_unwind_section); 1086 return false; 1087 } 1088 1089 // look up LSDA, if encoding says function has one 1090 if (encoding & UNWIND_HAS_LSDA) { 1091 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr); 1092 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base); 1093 low = 0; 1094 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) / 1095 sizeof(unwind_info_section_header_lsda_index_entry); 1096 // binary search looks for entry with exact match for functionOffset 1097 if (log) 1098 fprintf(stderr, 1099 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n", 1100 funcStartOffset); 1101 while (low < high) { 1102 uint32_t mid = (low + high) / 2; 1103 if (lsdaIndex.functionOffset(mid) == funcStartOffset) { 1104 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base; 1105 break; 1106 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) { 1107 low = mid + 1; 1108 } else { 1109 high = mid; 1110 } 1111 } 1112 if (lsda == 0) { 1113 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for " 1114 "pc=0x%0llX, but lsda table has no entry\n", 1115 encoding, (uint64_t) pc); 1116 return false; 1117 } 1118 } 1119 1120 // extact personality routine, if encoding says function has one 1121 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >> 1122 (__builtin_ctz(UNWIND_PERSONALITY_MASK)); 1123 if (personalityIndex != 0) { 1124 --personalityIndex; // change 1-based to zero-based index 1125 if (personalityIndex > sectionHeader.personalityArrayCount()) { 1126 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, " 1127 "but personality table has only %d entires\n", 1128 encoding, personalityIndex, 1129 sectionHeader.personalityArrayCount()); 1130 return false; 1131 } 1132 int32_t personalityDelta = (int32_t)_addressSpace.get32( 1133 sects.compact_unwind_section + 1134 sectionHeader.personalityArraySectionOffset() + 1135 personalityIndex * sizeof(uint32_t)); 1136 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta; 1137 personality = _addressSpace.getP(personalityPointer); 1138 if (log) 1139 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1140 "personalityDelta=0x%08X, personality=0x%08llX\n", 1141 (uint64_t) pc, personalityDelta, (uint64_t) personality); 1142 } 1143 1144 if (log) 1145 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1146 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n", 1147 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart); 1148 _info.start_ip = funcStart; 1149 _info.end_ip = funcEnd; 1150 _info.lsda = lsda; 1151 _info.handler = personality; 1152 _info.gp = 0; 1153 _info.flags = 0; 1154 _info.format = encoding; 1155 _info.unwind_info = 0; 1156 _info.unwind_info_size = 0; 1157 _info.extra = sects.dso_base; 1158 return true; 1159} 1160#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1161 1162 1163template <typename A, typename R> 1164void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) { 1165 pint_t pc = (pint_t)this->getReg(UNW_REG_IP); 1166#if _LIBUNWIND_ARM_EHABI 1167 // Remove the thumb bit so the IP represents the actual instruction address. 1168 // This matches the behaviour of _Unwind_GetIP on arm. 1169 pc &= (pint_t)~0x1; 1170#endif 1171 1172 // If the last line of a function is a "throw" the compiler sometimes 1173 // emits no instructions after the call to __cxa_throw. This means 1174 // the return address is actually the start of the next function. 1175 // To disambiguate this, back up the pc when we know it is a return 1176 // address. 1177 if (isReturnAddress) 1178 --pc; 1179 1180 // Ask address space object to find unwind sections for this pc. 1181 UnwindInfoSections sects; 1182 if (_addressSpace.findUnwindSections(pc, sects)) { 1183#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1184 // If there is a compact unwind encoding table, look there first. 1185 if (sects.compact_unwind_section != 0) { 1186 if (this->getInfoFromCompactEncodingSection(pc, sects)) { 1187 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1188 // Found info in table, done unless encoding says to use dwarf. 1189 uint32_t dwarfOffset; 1190 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) { 1191 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) { 1192 // found info in dwarf, done 1193 return; 1194 } 1195 } 1196 #endif 1197 // If unwind table has entry, but entry says there is no unwind info, 1198 // record that we have no unwind info. 1199 if (_info.format == 0) 1200 _unwindInfoMissing = true; 1201 return; 1202 } 1203 } 1204#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1205 1206#if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1207 // If there is dwarf unwind info, look there next. 1208 if (sects.dwarf_section != 0) { 1209 if (this->getInfoFromDwarfSection(pc, sects)) { 1210 // found info in dwarf, done 1211 return; 1212 } 1213 } 1214#endif 1215 1216#if _LIBUNWIND_ARM_EHABI 1217 // If there is ARM EHABI unwind info, look there next. 1218 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects)) 1219 return; 1220#endif 1221 } 1222 1223#if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1224 // There is no static unwind info for this pc. Look to see if an FDE was 1225 // dynamically registered for it. 1226 pint_t cachedFDE = DwarfFDECache<A>::findFDE(0, pc); 1227 if (cachedFDE != 0) { 1228 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1229 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1230 const char *msg = CFI_Parser<A>::decodeFDE(_addressSpace, 1231 cachedFDE, &fdeInfo, &cieInfo); 1232 if (msg == NULL) { 1233 typename CFI_Parser<A>::PrologInfo prolog; 1234 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, 1235 pc, &prolog)) { 1236 // save off parsed FDE info 1237 _info.start_ip = fdeInfo.pcStart; 1238 _info.end_ip = fdeInfo.pcEnd; 1239 _info.lsda = fdeInfo.lsda; 1240 _info.handler = cieInfo.personality; 1241 _info.gp = prolog.spExtraArgSize; 1242 // Some frameless functions need SP 1243 // altered when resuming in function. 1244 _info.flags = 0; 1245 _info.format = dwarfEncoding(); 1246 _info.unwind_info = fdeInfo.fdeStart; 1247 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1248 _info.extra = 0; 1249 return; 1250 } 1251 } 1252 } 1253 1254 // Lastly, ask AddressSpace object about platform specific ways to locate 1255 // other FDEs. 1256 pint_t fde; 1257 if (_addressSpace.findOtherFDE(pc, fde)) { 1258 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1259 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1260 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) { 1261 // Double check this FDE is for a function that includes the pc. 1262 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) { 1263 typename CFI_Parser<A>::PrologInfo prolog; 1264 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, 1265 cieInfo, pc, &prolog)) { 1266 // save off parsed FDE info 1267 _info.start_ip = fdeInfo.pcStart; 1268 _info.end_ip = fdeInfo.pcEnd; 1269 _info.lsda = fdeInfo.lsda; 1270 _info.handler = cieInfo.personality; 1271 _info.gp = prolog.spExtraArgSize; 1272 _info.flags = 0; 1273 _info.format = dwarfEncoding(); 1274 _info.unwind_info = fdeInfo.fdeStart; 1275 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1276 _info.extra = 0; 1277 return; 1278 } 1279 } 1280 } 1281 } 1282#endif // #if _LIBUNWIND_SUPPORT_DWARF_UNWIND 1283 1284 // no unwind info, flag that we can't reliably unwind 1285 _unwindInfoMissing = true; 1286} 1287 1288template <typename A, typename R> 1289int UnwindCursor<A, R>::step() { 1290 // Bottom of stack is defined is when unwind info cannot be found. 1291 if (_unwindInfoMissing) 1292 return UNW_STEP_END; 1293 1294 // Use unwinding info to modify register set as if function returned. 1295 int result; 1296#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1297 result = this->stepWithCompactEncoding(); 1298#elif _LIBUNWIND_SUPPORT_DWARF_UNWIND 1299 result = this->stepWithDwarfFDE(); 1300#elif _LIBUNWIND_ARM_EHABI 1301 result = this->stepWithEHABI(); 1302#else 1303 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \ 1304 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \ 1305 _LIBUNWIND_ARM_EHABI 1306#endif 1307 1308 // update info based on new PC 1309 if (result == UNW_STEP_SUCCESS) { 1310 this->setInfoBasedOnIPRegister(true); 1311 if (_unwindInfoMissing) 1312 return UNW_STEP_END; 1313 if (_info.gp) 1314 setReg(UNW_REG_SP, getReg(UNW_REG_SP) + _info.gp); 1315 } 1316 1317 return result; 1318} 1319 1320template <typename A, typename R> 1321void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) { 1322 *info = _info; 1323} 1324 1325template <typename A, typename R> 1326bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen, 1327 unw_word_t *offset) { 1328 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP), 1329 buf, bufLen, offset); 1330} 1331 1332} // namespace libunwind 1333 1334#endif // __UNWINDCURSOR_HPP__ 1335