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 libunwind 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 <unwind.h> 20 21 #ifdef __APPLE__ 22 #include <mach-o/dyld.h> 23 #endif 24 25 #include "config.h" 26 27 #include "AddressSpace.hpp" 28 #include "CompactUnwinder.hpp" 29 #include "config.h" 30 #include "DwarfInstructions.hpp" 31 #include "EHHeaderParser.hpp" 32 #include "libunwind.h" 33 #include "Registers.hpp" 34 #include "RWMutex.hpp" 35 #include "Unwind-EHABI.h" 36 37 namespace libunwind { 38 39 #if defined(_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 RWMutex _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 RWMutex DwarfFDECache<A>::_lock; 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_IF_FALSE(_lock.lock_shared()); 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_IF_FALSE(_lock.unlock_shared()); 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 #if !defined(_LIBUNWIND_NO_HEAP) 118 _LIBUNWIND_LOG_IF_FALSE(_lock.lock()); 119 if (_bufferUsed >= _bufferEnd) { 120 size_t oldSize = (size_t)(_bufferEnd - _buffer); 121 size_t newSize = oldSize * 4; 122 // Can't use operator new (we are below it). 123 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry)); 124 memcpy(newBuffer, _buffer, oldSize * sizeof(entry)); 125 if (_buffer != _initialBuffer) 126 free(_buffer); 127 _buffer = newBuffer; 128 _bufferUsed = &newBuffer[oldSize]; 129 _bufferEnd = &newBuffer[newSize]; 130 } 131 _bufferUsed->mh = mh; 132 _bufferUsed->ip_start = ip_start; 133 _bufferUsed->ip_end = ip_end; 134 _bufferUsed->fde = fde; 135 ++_bufferUsed; 136 #ifdef __APPLE__ 137 if (!_registeredForDyldUnloads) { 138 _dyld_register_func_for_remove_image(&dyldUnloadHook); 139 _registeredForDyldUnloads = true; 140 } 141 #endif 142 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock()); 143 #endif 144 } 145 146 template <typename A> 147 void DwarfFDECache<A>::removeAllIn(pint_t mh) { 148 _LIBUNWIND_LOG_IF_FALSE(_lock.lock()); 149 entry *d = _buffer; 150 for (const entry *s = _buffer; s < _bufferUsed; ++s) { 151 if (s->mh != mh) { 152 if (d != s) 153 *d = *s; 154 ++d; 155 } 156 } 157 _bufferUsed = d; 158 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock()); 159 } 160 161 #ifdef __APPLE__ 162 template <typename A> 163 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) { 164 removeAllIn((pint_t) mh); 165 } 166 #endif 167 168 template <typename A> 169 void DwarfFDECache<A>::iterateCacheEntries(void (*func)( 170 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) { 171 _LIBUNWIND_LOG_IF_FALSE(_lock.lock()); 172 for (entry *p = _buffer; p < _bufferUsed; ++p) { 173 (*func)(p->ip_start, p->ip_end, p->fde, p->mh); 174 } 175 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock()); 176 } 177 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 178 179 180 #define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field)) 181 182 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 183 template <typename A> class UnwindSectionHeader { 184 public: 185 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr) 186 : _addressSpace(addressSpace), _addr(addr) {} 187 188 uint32_t version() const { 189 return _addressSpace.get32(_addr + 190 offsetof(unwind_info_section_header, version)); 191 } 192 uint32_t commonEncodingsArraySectionOffset() const { 193 return _addressSpace.get32(_addr + 194 offsetof(unwind_info_section_header, 195 commonEncodingsArraySectionOffset)); 196 } 197 uint32_t commonEncodingsArrayCount() const { 198 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 199 commonEncodingsArrayCount)); 200 } 201 uint32_t personalityArraySectionOffset() const { 202 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 203 personalityArraySectionOffset)); 204 } 205 uint32_t personalityArrayCount() const { 206 return _addressSpace.get32( 207 _addr + offsetof(unwind_info_section_header, personalityArrayCount)); 208 } 209 uint32_t indexSectionOffset() const { 210 return _addressSpace.get32( 211 _addr + offsetof(unwind_info_section_header, indexSectionOffset)); 212 } 213 uint32_t indexCount() const { 214 return _addressSpace.get32( 215 _addr + offsetof(unwind_info_section_header, indexCount)); 216 } 217 218 private: 219 A &_addressSpace; 220 typename A::pint_t _addr; 221 }; 222 223 template <typename A> class UnwindSectionIndexArray { 224 public: 225 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr) 226 : _addressSpace(addressSpace), _addr(addr) {} 227 228 uint32_t functionOffset(uint32_t index) const { 229 return _addressSpace.get32( 230 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 231 functionOffset)); 232 } 233 uint32_t secondLevelPagesSectionOffset(uint32_t index) const { 234 return _addressSpace.get32( 235 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 236 secondLevelPagesSectionOffset)); 237 } 238 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const { 239 return _addressSpace.get32( 240 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 241 lsdaIndexArraySectionOffset)); 242 } 243 244 private: 245 A &_addressSpace; 246 typename A::pint_t _addr; 247 }; 248 249 template <typename A> class UnwindSectionRegularPageHeader { 250 public: 251 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr) 252 : _addressSpace(addressSpace), _addr(addr) {} 253 254 uint32_t kind() const { 255 return _addressSpace.get32( 256 _addr + offsetof(unwind_info_regular_second_level_page_header, kind)); 257 } 258 uint16_t entryPageOffset() const { 259 return _addressSpace.get16( 260 _addr + offsetof(unwind_info_regular_second_level_page_header, 261 entryPageOffset)); 262 } 263 uint16_t entryCount() const { 264 return _addressSpace.get16( 265 _addr + 266 offsetof(unwind_info_regular_second_level_page_header, entryCount)); 267 } 268 269 private: 270 A &_addressSpace; 271 typename A::pint_t _addr; 272 }; 273 274 template <typename A> class UnwindSectionRegularArray { 275 public: 276 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr) 277 : _addressSpace(addressSpace), _addr(addr) {} 278 279 uint32_t functionOffset(uint32_t index) const { 280 return _addressSpace.get32( 281 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index, 282 functionOffset)); 283 } 284 uint32_t encoding(uint32_t index) const { 285 return _addressSpace.get32( 286 _addr + 287 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding)); 288 } 289 290 private: 291 A &_addressSpace; 292 typename A::pint_t _addr; 293 }; 294 295 template <typename A> class UnwindSectionCompressedPageHeader { 296 public: 297 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr) 298 : _addressSpace(addressSpace), _addr(addr) {} 299 300 uint32_t kind() const { 301 return _addressSpace.get32( 302 _addr + 303 offsetof(unwind_info_compressed_second_level_page_header, kind)); 304 } 305 uint16_t entryPageOffset() const { 306 return _addressSpace.get16( 307 _addr + offsetof(unwind_info_compressed_second_level_page_header, 308 entryPageOffset)); 309 } 310 uint16_t entryCount() const { 311 return _addressSpace.get16( 312 _addr + 313 offsetof(unwind_info_compressed_second_level_page_header, entryCount)); 314 } 315 uint16_t encodingsPageOffset() const { 316 return _addressSpace.get16( 317 _addr + offsetof(unwind_info_compressed_second_level_page_header, 318 encodingsPageOffset)); 319 } 320 uint16_t encodingsCount() const { 321 return _addressSpace.get16( 322 _addr + offsetof(unwind_info_compressed_second_level_page_header, 323 encodingsCount)); 324 } 325 326 private: 327 A &_addressSpace; 328 typename A::pint_t _addr; 329 }; 330 331 template <typename A> class UnwindSectionCompressedArray { 332 public: 333 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr) 334 : _addressSpace(addressSpace), _addr(addr) {} 335 336 uint32_t functionOffset(uint32_t index) const { 337 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET( 338 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 339 } 340 uint16_t encodingIndex(uint32_t index) const { 341 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX( 342 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 343 } 344 345 private: 346 A &_addressSpace; 347 typename A::pint_t _addr; 348 }; 349 350 template <typename A> class UnwindSectionLsdaArray { 351 public: 352 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr) 353 : _addressSpace(addressSpace), _addr(addr) {} 354 355 uint32_t functionOffset(uint32_t index) const { 356 return _addressSpace.get32( 357 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 358 index, functionOffset)); 359 } 360 uint32_t lsdaOffset(uint32_t index) const { 361 return _addressSpace.get32( 362 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 363 index, lsdaOffset)); 364 } 365 366 private: 367 A &_addressSpace; 368 typename A::pint_t _addr; 369 }; 370 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 371 372 class _LIBUNWIND_HIDDEN AbstractUnwindCursor { 373 public: 374 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20) 375 // This avoids an unnecessary dependency to libc++abi. 376 void operator delete(void *, size_t) {} 377 378 virtual ~AbstractUnwindCursor() {} 379 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); } 380 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); } 381 virtual void setReg(int, unw_word_t) { 382 _LIBUNWIND_ABORT("setReg not implemented"); 383 } 384 virtual bool validFloatReg(int) { 385 _LIBUNWIND_ABORT("validFloatReg not implemented"); 386 } 387 virtual unw_fpreg_t getFloatReg(int) { 388 _LIBUNWIND_ABORT("getFloatReg not implemented"); 389 } 390 virtual void setFloatReg(int, unw_fpreg_t) { 391 _LIBUNWIND_ABORT("setFloatReg not implemented"); 392 } 393 virtual int step() { _LIBUNWIND_ABORT("step not implemented"); } 394 virtual void getInfo(unw_proc_info_t *) { 395 _LIBUNWIND_ABORT("getInfo not implemented"); 396 } 397 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); } 398 virtual bool isSignalFrame() { 399 _LIBUNWIND_ABORT("isSignalFrame not implemented"); 400 } 401 virtual bool getFunctionName(char *, size_t, unw_word_t *) { 402 _LIBUNWIND_ABORT("getFunctionName not implemented"); 403 } 404 virtual void setInfoBasedOnIPRegister(bool = false) { 405 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented"); 406 } 407 virtual const char *getRegisterName(int) { 408 _LIBUNWIND_ABORT("getRegisterName not implemented"); 409 } 410 #ifdef __arm__ 411 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); } 412 #endif 413 }; 414 415 /// UnwindCursor contains all state (including all register values) during 416 /// an unwind. This is normally stack allocated inside a unw_cursor_t. 417 template <typename A, typename R> 418 class UnwindCursor : public AbstractUnwindCursor{ 419 typedef typename A::pint_t pint_t; 420 public: 421 UnwindCursor(unw_context_t *context, A &as); 422 UnwindCursor(A &as, void *threadArg); 423 virtual ~UnwindCursor() {} 424 virtual bool validReg(int); 425 virtual unw_word_t getReg(int); 426 virtual void setReg(int, unw_word_t); 427 virtual bool validFloatReg(int); 428 virtual unw_fpreg_t getFloatReg(int); 429 virtual void setFloatReg(int, unw_fpreg_t); 430 virtual int step(); 431 virtual void getInfo(unw_proc_info_t *); 432 virtual void jumpto(); 433 virtual bool isSignalFrame(); 434 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off); 435 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false); 436 virtual const char *getRegisterName(int num); 437 #ifdef __arm__ 438 virtual void saveVFPAsX(); 439 #endif 440 441 private: 442 443 #if defined(_LIBUNWIND_ARM_EHABI) 444 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s); 445 446 int stepWithEHABI() { 447 size_t len = 0; 448 size_t off = 0; 449 // FIXME: Calling decode_eht_entry() here is violating the libunwind 450 // abstraction layer. 451 const uint32_t *ehtp = 452 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info), 453 &off, &len); 454 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) != 455 _URC_CONTINUE_UNWIND) 456 return UNW_STEP_END; 457 return UNW_STEP_SUCCESS; 458 } 459 #endif 460 461 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 462 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s, 463 uint32_t fdeSectionOffsetHint=0); 464 int stepWithDwarfFDE() { 465 return DwarfInstructions<A, R>::stepWithDwarf(_addressSpace, 466 (pint_t)this->getReg(UNW_REG_IP), 467 (pint_t)_info.unwind_info, 468 _registers); 469 } 470 #endif 471 472 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 473 bool getInfoFromCompactEncodingSection(pint_t pc, 474 const UnwindInfoSections §s); 475 int stepWithCompactEncoding() { 476 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 477 if ( compactSaysUseDwarf() ) 478 return stepWithDwarfFDE(); 479 #endif 480 R dummy; 481 return stepWithCompactEncoding(dummy); 482 } 483 484 #if defined(_LIBUNWIND_TARGET_X86_64) 485 int stepWithCompactEncoding(Registers_x86_64 &) { 486 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding( 487 _info.format, _info.start_ip, _addressSpace, _registers); 488 } 489 #endif 490 491 #if defined(_LIBUNWIND_TARGET_I386) 492 int stepWithCompactEncoding(Registers_x86 &) { 493 return CompactUnwinder_x86<A>::stepWithCompactEncoding( 494 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers); 495 } 496 #endif 497 498 #if defined(_LIBUNWIND_TARGET_PPC) 499 int stepWithCompactEncoding(Registers_ppc &) { 500 return UNW_EINVAL; 501 } 502 #endif 503 504 #if defined(_LIBUNWIND_TARGET_AARCH64) 505 int stepWithCompactEncoding(Registers_arm64 &) { 506 return CompactUnwinder_arm64<A>::stepWithCompactEncoding( 507 _info.format, _info.start_ip, _addressSpace, _registers); 508 } 509 #endif 510 511 #if defined(_LIBUNWIND_TARGET_MIPS_O32) 512 int stepWithCompactEncoding(Registers_mips_o32 &) { 513 return UNW_EINVAL; 514 } 515 #endif 516 517 #if defined(_LIBUNWIND_TARGET_MIPS_N64) 518 int stepWithCompactEncoding(Registers_mips_n64 &) { 519 return UNW_EINVAL; 520 } 521 #endif 522 523 bool compactSaysUseDwarf(uint32_t *offset=NULL) const { 524 R dummy; 525 return compactSaysUseDwarf(dummy, offset); 526 } 527 528 #if defined(_LIBUNWIND_TARGET_X86_64) 529 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const { 530 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) { 531 if (offset) 532 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET); 533 return true; 534 } 535 return false; 536 } 537 #endif 538 539 #if defined(_LIBUNWIND_TARGET_I386) 540 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const { 541 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) { 542 if (offset) 543 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET); 544 return true; 545 } 546 return false; 547 } 548 #endif 549 550 #if defined(_LIBUNWIND_TARGET_PPC) 551 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const { 552 return true; 553 } 554 #endif 555 556 #if defined(_LIBUNWIND_TARGET_AARCH64) 557 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const { 558 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) { 559 if (offset) 560 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET); 561 return true; 562 } 563 return false; 564 } 565 #endif 566 567 #if defined(_LIBUNWIND_TARGET_MIPS_O32) 568 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const { 569 return true; 570 } 571 #endif 572 573 #if defined(_LIBUNWIND_TARGET_MIPS_N64) 574 bool compactSaysUseDwarf(Registers_mips_n64 &, uint32_t *) const { 575 return true; 576 } 577 #endif 578 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 579 580 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 581 compact_unwind_encoding_t dwarfEncoding() const { 582 R dummy; 583 return dwarfEncoding(dummy); 584 } 585 586 #if defined(_LIBUNWIND_TARGET_X86_64) 587 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const { 588 return UNWIND_X86_64_MODE_DWARF; 589 } 590 #endif 591 592 #if defined(_LIBUNWIND_TARGET_I386) 593 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const { 594 return UNWIND_X86_MODE_DWARF; 595 } 596 #endif 597 598 #if defined(_LIBUNWIND_TARGET_PPC) 599 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const { 600 return 0; 601 } 602 #endif 603 604 #if defined(_LIBUNWIND_TARGET_AARCH64) 605 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const { 606 return UNWIND_ARM64_MODE_DWARF; 607 } 608 #endif 609 610 #if defined(_LIBUNWIND_TARGET_ARM) 611 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const { 612 return 0; 613 } 614 #endif 615 616 #if defined (_LIBUNWIND_TARGET_OR1K) 617 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const { 618 return 0; 619 } 620 #endif 621 622 #if defined (_LIBUNWIND_TARGET_MIPS_O32) 623 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const { 624 return 0; 625 } 626 #endif 627 628 #if defined (_LIBUNWIND_TARGET_MIPS_N64) 629 compact_unwind_encoding_t dwarfEncoding(Registers_mips_n64 &) const { 630 return 0; 631 } 632 #endif 633 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 634 635 636 A &_addressSpace; 637 R _registers; 638 unw_proc_info_t _info; 639 bool _unwindInfoMissing; 640 bool _isSignalFrame; 641 }; 642 643 644 template <typename A, typename R> 645 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as) 646 : _addressSpace(as), _registers(context), _unwindInfoMissing(false), 647 _isSignalFrame(false) { 648 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit), 649 "UnwindCursor<> does not fit in unw_cursor_t"); 650 memset(&_info, 0, sizeof(_info)); 651 } 652 653 template <typename A, typename R> 654 UnwindCursor<A, R>::UnwindCursor(A &as, void *) 655 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) { 656 memset(&_info, 0, sizeof(_info)); 657 // FIXME 658 // fill in _registers from thread arg 659 } 660 661 662 template <typename A, typename R> 663 bool UnwindCursor<A, R>::validReg(int regNum) { 664 return _registers.validRegister(regNum); 665 } 666 667 template <typename A, typename R> 668 unw_word_t UnwindCursor<A, R>::getReg(int regNum) { 669 return _registers.getRegister(regNum); 670 } 671 672 template <typename A, typename R> 673 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) { 674 _registers.setRegister(regNum, (typename A::pint_t)value); 675 } 676 677 template <typename A, typename R> 678 bool UnwindCursor<A, R>::validFloatReg(int regNum) { 679 return _registers.validFloatRegister(regNum); 680 } 681 682 template <typename A, typename R> 683 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) { 684 return _registers.getFloatRegister(regNum); 685 } 686 687 template <typename A, typename R> 688 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) { 689 _registers.setFloatRegister(regNum, value); 690 } 691 692 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() { 693 _registers.jumpto(); 694 } 695 696 #ifdef __arm__ 697 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() { 698 _registers.saveVFPAsX(); 699 } 700 #endif 701 702 template <typename A, typename R> 703 const char *UnwindCursor<A, R>::getRegisterName(int regNum) { 704 return _registers.getRegisterName(regNum); 705 } 706 707 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() { 708 return _isSignalFrame; 709 } 710 711 #if defined(_LIBUNWIND_ARM_EHABI) 712 struct EHABIIndexEntry { 713 uint32_t functionOffset; 714 uint32_t data; 715 }; 716 717 template<typename A> 718 struct EHABISectionIterator { 719 typedef EHABISectionIterator _Self; 720 721 typedef std::random_access_iterator_tag iterator_category; 722 typedef typename A::pint_t value_type; 723 typedef typename A::pint_t* pointer; 724 typedef typename A::pint_t& reference; 725 typedef size_t size_type; 726 typedef size_t difference_type; 727 728 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) { 729 return _Self(addressSpace, sects, 0); 730 } 731 static _Self end(A& addressSpace, const UnwindInfoSections& sects) { 732 return _Self(addressSpace, sects, 733 sects.arm_section_length / sizeof(EHABIIndexEntry)); 734 } 735 736 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i) 737 : _i(i), _addressSpace(&addressSpace), _sects(§s) {} 738 739 _Self& operator++() { ++_i; return *this; } 740 _Self& operator+=(size_t a) { _i += a; return *this; } 741 _Self& operator--() { assert(_i > 0); --_i; return *this; } 742 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; } 743 744 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; } 745 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; } 746 747 size_t operator-(const _Self& other) { return _i - other._i; } 748 749 bool operator==(const _Self& other) const { 750 assert(_addressSpace == other._addressSpace); 751 assert(_sects == other._sects); 752 return _i == other._i; 753 } 754 755 typename A::pint_t operator*() const { return functionAddress(); } 756 757 typename A::pint_t functionAddress() const { 758 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 759 EHABIIndexEntry, _i, functionOffset); 760 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr)); 761 } 762 763 typename A::pint_t dataAddress() { 764 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 765 EHABIIndexEntry, _i, data); 766 return indexAddr; 767 } 768 769 private: 770 size_t _i; 771 A* _addressSpace; 772 const UnwindInfoSections* _sects; 773 }; 774 775 template <typename A, typename R> 776 bool UnwindCursor<A, R>::getInfoFromEHABISection( 777 pint_t pc, 778 const UnwindInfoSections §s) { 779 EHABISectionIterator<A> begin = 780 EHABISectionIterator<A>::begin(_addressSpace, sects); 781 EHABISectionIterator<A> end = 782 EHABISectionIterator<A>::end(_addressSpace, sects); 783 if (begin == end) 784 return false; 785 786 EHABISectionIterator<A> itNextPC = std::upper_bound(begin, end, pc); 787 if (itNextPC == begin) 788 return false; 789 EHABISectionIterator<A> itThisPC = itNextPC - 1; 790 791 pint_t thisPC = itThisPC.functionAddress(); 792 // If an exception is thrown from a function, corresponding to the last entry 793 // in the table, we don't really know the function extent and have to choose a 794 // value for nextPC. Choosing max() will allow the range check during trace to 795 // succeed. 796 pint_t nextPC = (itNextPC == end) ? std::numeric_limits<pint_t>::max() 797 : itNextPC.functionAddress(); 798 pint_t indexDataAddr = itThisPC.dataAddress(); 799 800 if (indexDataAddr == 0) 801 return false; 802 803 uint32_t indexData = _addressSpace.get32(indexDataAddr); 804 if (indexData == UNW_EXIDX_CANTUNWIND) 805 return false; 806 807 // If the high bit is set, the exception handling table entry is inline inside 808 // the index table entry on the second word (aka |indexDataAddr|). Otherwise, 809 // the table points at an offset in the exception handling table (section 5 EHABI). 810 pint_t exceptionTableAddr; 811 uint32_t exceptionTableData; 812 bool isSingleWordEHT; 813 if (indexData & 0x80000000) { 814 exceptionTableAddr = indexDataAddr; 815 // TODO(ajwong): Should this data be 0? 816 exceptionTableData = indexData; 817 isSingleWordEHT = true; 818 } else { 819 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData); 820 exceptionTableData = _addressSpace.get32(exceptionTableAddr); 821 isSingleWordEHT = false; 822 } 823 824 // Now we know the 3 things: 825 // exceptionTableAddr -- exception handler table entry. 826 // exceptionTableData -- the data inside the first word of the eht entry. 827 // isSingleWordEHT -- whether the entry is in the index. 828 unw_word_t personalityRoutine = 0xbadf00d; 829 bool scope32 = false; 830 uintptr_t lsda; 831 832 // If the high bit in the exception handling table entry is set, the entry is 833 // in compact form (section 6.3 EHABI). 834 if (exceptionTableData & 0x80000000) { 835 // Grab the index of the personality routine from the compact form. 836 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24; 837 uint32_t extraWords = 0; 838 switch (choice) { 839 case 0: 840 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0; 841 extraWords = 0; 842 scope32 = false; 843 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4); 844 break; 845 case 1: 846 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1; 847 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 848 scope32 = false; 849 lsda = exceptionTableAddr + (extraWords + 1) * 4; 850 break; 851 case 2: 852 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2; 853 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 854 scope32 = true; 855 lsda = exceptionTableAddr + (extraWords + 1) * 4; 856 break; 857 default: 858 _LIBUNWIND_ABORT("unknown personality routine"); 859 return false; 860 } 861 862 if (isSingleWordEHT) { 863 if (extraWords != 0) { 864 _LIBUNWIND_ABORT("index inlined table detected but pr function " 865 "requires extra words"); 866 return false; 867 } 868 } 869 } else { 870 pint_t personalityAddr = 871 exceptionTableAddr + signExtendPrel31(exceptionTableData); 872 personalityRoutine = personalityAddr; 873 874 // ARM EHABI # 6.2, # 9.2 875 // 876 // +---- ehtp 877 // v 878 // +--------------------------------------+ 879 // | +--------+--------+--------+-------+ | 880 // | |0| prel31 to personalityRoutine | | 881 // | +--------+--------+--------+-------+ | 882 // | | N | unwind opcodes | | <-- UnwindData 883 // | +--------+--------+--------+-------+ | 884 // | | Word 2 unwind opcodes | | 885 // | +--------+--------+--------+-------+ | 886 // | ... | 887 // | +--------+--------+--------+-------+ | 888 // | | Word N unwind opcodes | | 889 // | +--------+--------+--------+-------+ | 890 // | | LSDA | | <-- lsda 891 // | | ... | | 892 // | +--------+--------+--------+-------+ | 893 // +--------------------------------------+ 894 895 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1; 896 uint32_t FirstDataWord = *UnwindData; 897 size_t N = ((FirstDataWord >> 24) & 0xff); 898 size_t NDataWords = N + 1; 899 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords); 900 } 901 902 _info.start_ip = thisPC; 903 _info.end_ip = nextPC; 904 _info.handler = personalityRoutine; 905 _info.unwind_info = exceptionTableAddr; 906 _info.lsda = lsda; 907 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0. 908 _info.flags = isSingleWordEHT ? 1 : 0 | scope32 ? 0x2 : 0; // Use enum? 909 910 return true; 911 } 912 #endif 913 914 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 915 template <typename A, typename R> 916 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc, 917 const UnwindInfoSections §s, 918 uint32_t fdeSectionOffsetHint) { 919 typename CFI_Parser<A>::FDE_Info fdeInfo; 920 typename CFI_Parser<A>::CIE_Info cieInfo; 921 bool foundFDE = false; 922 bool foundInCache = false; 923 // If compact encoding table gave offset into dwarf section, go directly there 924 if (fdeSectionOffsetHint != 0) { 925 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 926 (uint32_t)sects.dwarf_section_length, 927 sects.dwarf_section + fdeSectionOffsetHint, 928 &fdeInfo, &cieInfo); 929 } 930 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 931 if (!foundFDE && (sects.dwarf_index_section != 0)) { 932 foundFDE = EHHeaderParser<A>::findFDE( 933 _addressSpace, pc, sects.dwarf_index_section, 934 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo); 935 } 936 #endif 937 if (!foundFDE) { 938 // otherwise, search cache of previously found FDEs. 939 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc); 940 if (cachedFDE != 0) { 941 foundFDE = 942 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 943 (uint32_t)sects.dwarf_section_length, 944 cachedFDE, &fdeInfo, &cieInfo); 945 foundInCache = foundFDE; 946 } 947 } 948 if (!foundFDE) { 949 // Still not found, do full scan of __eh_frame section. 950 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 951 (uint32_t)sects.dwarf_section_length, 0, 952 &fdeInfo, &cieInfo); 953 } 954 if (foundFDE) { 955 typename CFI_Parser<A>::PrologInfo prolog; 956 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc, 957 &prolog)) { 958 // Save off parsed FDE info 959 _info.start_ip = fdeInfo.pcStart; 960 _info.end_ip = fdeInfo.pcEnd; 961 _info.lsda = fdeInfo.lsda; 962 _info.handler = cieInfo.personality; 963 _info.gp = prolog.spExtraArgSize; 964 _info.flags = 0; 965 _info.format = dwarfEncoding(); 966 _info.unwind_info = fdeInfo.fdeStart; 967 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 968 _info.extra = (unw_word_t) sects.dso_base; 969 970 // Add to cache (to make next lookup faster) if we had no hint 971 // and there was no index. 972 if (!foundInCache && (fdeSectionOffsetHint == 0)) { 973 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 974 if (sects.dwarf_index_section == 0) 975 #endif 976 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd, 977 fdeInfo.fdeStart); 978 } 979 return true; 980 } 981 } 982 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc); 983 return false; 984 } 985 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 986 987 988 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 989 template <typename A, typename R> 990 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc, 991 const UnwindInfoSections §s) { 992 const bool log = false; 993 if (log) 994 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n", 995 (uint64_t)pc, (uint64_t)sects.dso_base); 996 997 const UnwindSectionHeader<A> sectionHeader(_addressSpace, 998 sects.compact_unwind_section); 999 if (sectionHeader.version() != UNWIND_SECTION_VERSION) 1000 return false; 1001 1002 // do a binary search of top level index to find page with unwind info 1003 pint_t targetFunctionOffset = pc - sects.dso_base; 1004 const UnwindSectionIndexArray<A> topIndex(_addressSpace, 1005 sects.compact_unwind_section 1006 + sectionHeader.indexSectionOffset()); 1007 uint32_t low = 0; 1008 uint32_t high = sectionHeader.indexCount(); 1009 uint32_t last = high - 1; 1010 while (low < high) { 1011 uint32_t mid = (low + high) / 2; 1012 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n", 1013 //mid, low, high, topIndex.functionOffset(mid)); 1014 if (topIndex.functionOffset(mid) <= targetFunctionOffset) { 1015 if ((mid == last) || 1016 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) { 1017 low = mid; 1018 break; 1019 } else { 1020 low = mid + 1; 1021 } 1022 } else { 1023 high = mid; 1024 } 1025 } 1026 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low); 1027 const uint32_t firstLevelNextPageFunctionOffset = 1028 topIndex.functionOffset(low + 1); 1029 const pint_t secondLevelAddr = 1030 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low); 1031 const pint_t lsdaArrayStartAddr = 1032 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low); 1033 const pint_t lsdaArrayEndAddr = 1034 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1); 1035 if (log) 1036 fprintf(stderr, "\tfirst level search for result index=%d " 1037 "to secondLevelAddr=0x%llX\n", 1038 low, (uint64_t) secondLevelAddr); 1039 // do a binary search of second level page index 1040 uint32_t encoding = 0; 1041 pint_t funcStart = 0; 1042 pint_t funcEnd = 0; 1043 pint_t lsda = 0; 1044 pint_t personality = 0; 1045 uint32_t pageKind = _addressSpace.get32(secondLevelAddr); 1046 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) { 1047 // regular page 1048 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace, 1049 secondLevelAddr); 1050 UnwindSectionRegularArray<A> pageIndex( 1051 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 1052 // binary search looks for entry with e where index[e].offset <= pc < 1053 // index[e+1].offset 1054 if (log) 1055 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in " 1056 "regular page starting at secondLevelAddr=0x%llX\n", 1057 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr); 1058 low = 0; 1059 high = pageHeader.entryCount(); 1060 while (low < high) { 1061 uint32_t mid = (low + high) / 2; 1062 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) { 1063 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) { 1064 // at end of table 1065 low = mid; 1066 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 1067 break; 1068 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) { 1069 // next is too big, so we found it 1070 low = mid; 1071 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base; 1072 break; 1073 } else { 1074 low = mid + 1; 1075 } 1076 } else { 1077 high = mid; 1078 } 1079 } 1080 encoding = pageIndex.encoding(low); 1081 funcStart = pageIndex.functionOffset(low) + sects.dso_base; 1082 if (pc < funcStart) { 1083 if (log) 1084 fprintf( 1085 stderr, 1086 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 1087 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 1088 return false; 1089 } 1090 if (pc > funcEnd) { 1091 if (log) 1092 fprintf( 1093 stderr, 1094 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 1095 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 1096 return false; 1097 } 1098 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) { 1099 // compressed page 1100 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace, 1101 secondLevelAddr); 1102 UnwindSectionCompressedArray<A> pageIndex( 1103 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 1104 const uint32_t targetFunctionPageOffset = 1105 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset); 1106 // binary search looks for entry with e where index[e].offset <= pc < 1107 // index[e+1].offset 1108 if (log) 1109 fprintf(stderr, "\tbinary search of compressed page starting at " 1110 "secondLevelAddr=0x%llX\n", 1111 (uint64_t) secondLevelAddr); 1112 low = 0; 1113 last = pageHeader.entryCount() - 1; 1114 high = pageHeader.entryCount(); 1115 while (low < high) { 1116 uint32_t mid = (low + high) / 2; 1117 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) { 1118 if ((mid == last) || 1119 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) { 1120 low = mid; 1121 break; 1122 } else { 1123 low = mid + 1; 1124 } 1125 } else { 1126 high = mid; 1127 } 1128 } 1129 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset 1130 + sects.dso_base; 1131 if (low < last) 1132 funcEnd = 1133 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset 1134 + sects.dso_base; 1135 else 1136 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 1137 if (pc < funcStart) { 1138 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1139 "level compressed unwind table. funcStart=0x%llX", 1140 (uint64_t) pc, (uint64_t) funcStart); 1141 return false; 1142 } 1143 if (pc > funcEnd) { 1144 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second " 1145 "level compressed unwind table. funcEnd=0x%llX", 1146 (uint64_t) pc, (uint64_t) funcEnd); 1147 return false; 1148 } 1149 uint16_t encodingIndex = pageIndex.encodingIndex(low); 1150 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) { 1151 // encoding is in common table in section header 1152 encoding = _addressSpace.get32( 1153 sects.compact_unwind_section + 1154 sectionHeader.commonEncodingsArraySectionOffset() + 1155 encodingIndex * sizeof(uint32_t)); 1156 } else { 1157 // encoding is in page specific table 1158 uint16_t pageEncodingIndex = 1159 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount(); 1160 encoding = _addressSpace.get32(secondLevelAddr + 1161 pageHeader.encodingsPageOffset() + 1162 pageEncodingIndex * sizeof(uint32_t)); 1163 } 1164 } else { 1165 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info at 0x%0llX bad second " 1166 "level page", 1167 (uint64_t) sects.compact_unwind_section); 1168 return false; 1169 } 1170 1171 // look up LSDA, if encoding says function has one 1172 if (encoding & UNWIND_HAS_LSDA) { 1173 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr); 1174 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base); 1175 low = 0; 1176 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) / 1177 sizeof(unwind_info_section_header_lsda_index_entry); 1178 // binary search looks for entry with exact match for functionOffset 1179 if (log) 1180 fprintf(stderr, 1181 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n", 1182 funcStartOffset); 1183 while (low < high) { 1184 uint32_t mid = (low + high) / 2; 1185 if (lsdaIndex.functionOffset(mid) == funcStartOffset) { 1186 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base; 1187 break; 1188 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) { 1189 low = mid + 1; 1190 } else { 1191 high = mid; 1192 } 1193 } 1194 if (lsda == 0) { 1195 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for " 1196 "pc=0x%0llX, but lsda table has no entry", 1197 encoding, (uint64_t) pc); 1198 return false; 1199 } 1200 } 1201 1202 // extact personality routine, if encoding says function has one 1203 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >> 1204 (__builtin_ctz(UNWIND_PERSONALITY_MASK)); 1205 if (personalityIndex != 0) { 1206 --personalityIndex; // change 1-based to zero-based index 1207 if (personalityIndex > sectionHeader.personalityArrayCount()) { 1208 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, " 1209 "but personality table has only %d entires", 1210 encoding, personalityIndex, 1211 sectionHeader.personalityArrayCount()); 1212 return false; 1213 } 1214 int32_t personalityDelta = (int32_t)_addressSpace.get32( 1215 sects.compact_unwind_section + 1216 sectionHeader.personalityArraySectionOffset() + 1217 personalityIndex * sizeof(uint32_t)); 1218 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta; 1219 personality = _addressSpace.getP(personalityPointer); 1220 if (log) 1221 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1222 "personalityDelta=0x%08X, personality=0x%08llX\n", 1223 (uint64_t) pc, personalityDelta, (uint64_t) personality); 1224 } 1225 1226 if (log) 1227 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1228 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n", 1229 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart); 1230 _info.start_ip = funcStart; 1231 _info.end_ip = funcEnd; 1232 _info.lsda = lsda; 1233 _info.handler = personality; 1234 _info.gp = 0; 1235 _info.flags = 0; 1236 _info.format = encoding; 1237 _info.unwind_info = 0; 1238 _info.unwind_info_size = 0; 1239 _info.extra = sects.dso_base; 1240 return true; 1241 } 1242 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1243 1244 1245 template <typename A, typename R> 1246 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) { 1247 pint_t pc = (pint_t)this->getReg(UNW_REG_IP); 1248 #if defined(_LIBUNWIND_ARM_EHABI) 1249 // Remove the thumb bit so the IP represents the actual instruction address. 1250 // This matches the behaviour of _Unwind_GetIP on arm. 1251 pc &= (pint_t)~0x1; 1252 #endif 1253 1254 // If the last line of a function is a "throw" the compiler sometimes 1255 // emits no instructions after the call to __cxa_throw. This means 1256 // the return address is actually the start of the next function. 1257 // To disambiguate this, back up the pc when we know it is a return 1258 // address. 1259 if (isReturnAddress) 1260 --pc; 1261 1262 // Ask address space object to find unwind sections for this pc. 1263 UnwindInfoSections sects; 1264 if (_addressSpace.findUnwindSections(pc, sects)) { 1265 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1266 // If there is a compact unwind encoding table, look there first. 1267 if (sects.compact_unwind_section != 0) { 1268 if (this->getInfoFromCompactEncodingSection(pc, sects)) { 1269 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1270 // Found info in table, done unless encoding says to use dwarf. 1271 uint32_t dwarfOffset; 1272 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) { 1273 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) { 1274 // found info in dwarf, done 1275 return; 1276 } 1277 } 1278 #endif 1279 // If unwind table has entry, but entry says there is no unwind info, 1280 // record that we have no unwind info. 1281 if (_info.format == 0) 1282 _unwindInfoMissing = true; 1283 return; 1284 } 1285 } 1286 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1287 1288 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1289 // If there is dwarf unwind info, look there next. 1290 if (sects.dwarf_section != 0) { 1291 if (this->getInfoFromDwarfSection(pc, sects)) { 1292 // found info in dwarf, done 1293 return; 1294 } 1295 } 1296 #endif 1297 1298 #if defined(_LIBUNWIND_ARM_EHABI) 1299 // If there is ARM EHABI unwind info, look there next. 1300 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects)) 1301 return; 1302 #endif 1303 } 1304 1305 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1306 // There is no static unwind info for this pc. Look to see if an FDE was 1307 // dynamically registered for it. 1308 pint_t cachedFDE = DwarfFDECache<A>::findFDE(0, pc); 1309 if (cachedFDE != 0) { 1310 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1311 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1312 const char *msg = CFI_Parser<A>::decodeFDE(_addressSpace, 1313 cachedFDE, &fdeInfo, &cieInfo); 1314 if (msg == NULL) { 1315 typename CFI_Parser<A>::PrologInfo prolog; 1316 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, 1317 pc, &prolog)) { 1318 // save off parsed FDE info 1319 _info.start_ip = fdeInfo.pcStart; 1320 _info.end_ip = fdeInfo.pcEnd; 1321 _info.lsda = fdeInfo.lsda; 1322 _info.handler = cieInfo.personality; 1323 _info.gp = prolog.spExtraArgSize; 1324 // Some frameless functions need SP 1325 // altered when resuming in function. 1326 _info.flags = 0; 1327 _info.format = dwarfEncoding(); 1328 _info.unwind_info = fdeInfo.fdeStart; 1329 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1330 _info.extra = 0; 1331 return; 1332 } 1333 } 1334 } 1335 1336 // Lastly, ask AddressSpace object about platform specific ways to locate 1337 // other FDEs. 1338 pint_t fde; 1339 if (_addressSpace.findOtherFDE(pc, fde)) { 1340 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 1341 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 1342 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) { 1343 // Double check this FDE is for a function that includes the pc. 1344 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) { 1345 typename CFI_Parser<A>::PrologInfo prolog; 1346 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, 1347 cieInfo, pc, &prolog)) { 1348 // save off parsed FDE info 1349 _info.start_ip = fdeInfo.pcStart; 1350 _info.end_ip = fdeInfo.pcEnd; 1351 _info.lsda = fdeInfo.lsda; 1352 _info.handler = cieInfo.personality; 1353 _info.gp = prolog.spExtraArgSize; 1354 _info.flags = 0; 1355 _info.format = dwarfEncoding(); 1356 _info.unwind_info = fdeInfo.fdeStart; 1357 _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength; 1358 _info.extra = 0; 1359 return; 1360 } 1361 } 1362 } 1363 } 1364 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1365 1366 // no unwind info, flag that we can't reliably unwind 1367 _unwindInfoMissing = true; 1368 } 1369 1370 template <typename A, typename R> 1371 int UnwindCursor<A, R>::step() { 1372 // Bottom of stack is defined is when unwind info cannot be found. 1373 if (_unwindInfoMissing) 1374 return UNW_STEP_END; 1375 1376 // Use unwinding info to modify register set as if function returned. 1377 int result; 1378 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1379 result = this->stepWithCompactEncoding(); 1380 #elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1381 result = this->stepWithDwarfFDE(); 1382 #elif defined(_LIBUNWIND_ARM_EHABI) 1383 result = this->stepWithEHABI(); 1384 #else 1385 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \ 1386 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \ 1387 _LIBUNWIND_ARM_EHABI 1388 #endif 1389 1390 // update info based on new PC 1391 if (result == UNW_STEP_SUCCESS) { 1392 this->setInfoBasedOnIPRegister(true); 1393 if (_unwindInfoMissing) 1394 return UNW_STEP_END; 1395 if (_info.gp) 1396 setReg(UNW_REG_SP, getReg(UNW_REG_SP) + _info.gp); 1397 } 1398 1399 return result; 1400 } 1401 1402 template <typename A, typename R> 1403 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) { 1404 *info = _info; 1405 } 1406 1407 template <typename A, typename R> 1408 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen, 1409 unw_word_t *offset) { 1410 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP), 1411 buf, bufLen, offset); 1412 } 1413 1414 } // namespace libunwind 1415 1416 #endif // __UNWINDCURSOR_HPP__ 1417