1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 // 8 // C++ interface to lower levels of libunwind 9 //===----------------------------------------------------------------------===// 10 11 #ifndef __UNWINDCURSOR_HPP__ 12 #define __UNWINDCURSOR_HPP__ 13 14 #include "cet_unwind.h" 15 #include <stdint.h> 16 #include <stdio.h> 17 #include <stdlib.h> 18 #include <unwind.h> 19 20 #ifdef _WIN32 21 #include <windows.h> 22 #include <ntverp.h> 23 #endif 24 #ifdef __APPLE__ 25 #include <mach-o/dyld.h> 26 #endif 27 #ifdef _AIX 28 #include <dlfcn.h> 29 #include <sys/debug.h> 30 #include <sys/pseg.h> 31 #endif 32 33 #if defined(_LIBUNWIND_TARGET_LINUX) && \ 34 (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_RISCV) || \ 35 defined(_LIBUNWIND_TARGET_S390X)) 36 #include <errno.h> 37 #include <signal.h> 38 #include <sys/syscall.h> 39 #include <unistd.h> 40 #define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1 41 #endif 42 43 #include "AddressSpace.hpp" 44 #include "CompactUnwinder.hpp" 45 #include "config.h" 46 #include "DwarfInstructions.hpp" 47 #include "EHHeaderParser.hpp" 48 #include "libunwind.h" 49 #include "libunwind_ext.h" 50 #include "Registers.hpp" 51 #include "RWMutex.hpp" 52 #include "Unwind-EHABI.h" 53 54 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 55 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and 56 // earlier) SDKs. 57 // MinGW-w64 has always provided this struct. 58 #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \ 59 !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000 60 struct _DISPATCHER_CONTEXT { 61 ULONG64 ControlPc; 62 ULONG64 ImageBase; 63 PRUNTIME_FUNCTION FunctionEntry; 64 ULONG64 EstablisherFrame; 65 ULONG64 TargetIp; 66 PCONTEXT ContextRecord; 67 PEXCEPTION_ROUTINE LanguageHandler; 68 PVOID HandlerData; 69 PUNWIND_HISTORY_TABLE HistoryTable; 70 ULONG ScopeIndex; 71 ULONG Fill0; 72 }; 73 #endif 74 75 struct UNWIND_INFO { 76 uint8_t Version : 3; 77 uint8_t Flags : 5; 78 uint8_t SizeOfProlog; 79 uint8_t CountOfCodes; 80 uint8_t FrameRegister : 4; 81 uint8_t FrameOffset : 4; 82 uint16_t UnwindCodes[2]; 83 }; 84 85 extern "C" _Unwind_Reason_Code __libunwind_seh_personality( 86 int, _Unwind_Action, uint64_t, _Unwind_Exception *, 87 struct _Unwind_Context *); 88 89 #endif 90 91 namespace libunwind { 92 93 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 94 /// Cache of recently found FDEs. 95 template <typename A> 96 class _LIBUNWIND_HIDDEN DwarfFDECache { 97 typedef typename A::pint_t pint_t; 98 public: 99 static constexpr pint_t kSearchAll = static_cast<pint_t>(-1); 100 static pint_t findFDE(pint_t mh, pint_t pc); 101 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde); 102 static void removeAllIn(pint_t mh); 103 static void iterateCacheEntries(void (*func)(unw_word_t ip_start, 104 unw_word_t ip_end, 105 unw_word_t fde, unw_word_t mh)); 106 107 private: 108 109 struct entry { 110 pint_t mh; 111 pint_t ip_start; 112 pint_t ip_end; 113 pint_t fde; 114 }; 115 116 // These fields are all static to avoid needing an initializer. 117 // There is only one instance of this class per process. 118 static RWMutex _lock; 119 #ifdef __APPLE__ 120 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide); 121 static bool _registeredForDyldUnloads; 122 #endif 123 static entry *_buffer; 124 static entry *_bufferUsed; 125 static entry *_bufferEnd; 126 static entry _initialBuffer[64]; 127 }; 128 129 template <typename A> 130 typename DwarfFDECache<A>::entry * 131 DwarfFDECache<A>::_buffer = _initialBuffer; 132 133 template <typename A> 134 typename DwarfFDECache<A>::entry * 135 DwarfFDECache<A>::_bufferUsed = _initialBuffer; 136 137 template <typename A> 138 typename DwarfFDECache<A>::entry * 139 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64]; 140 141 template <typename A> 142 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64]; 143 144 template <typename A> 145 RWMutex DwarfFDECache<A>::_lock; 146 147 #ifdef __APPLE__ 148 template <typename A> 149 bool DwarfFDECache<A>::_registeredForDyldUnloads = false; 150 #endif 151 152 template <typename A> 153 typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) { 154 pint_t result = 0; 155 _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared()); 156 for (entry *p = _buffer; p < _bufferUsed; ++p) { 157 if ((mh == p->mh) || (mh == kSearchAll)) { 158 if ((p->ip_start <= pc) && (pc < p->ip_end)) { 159 result = p->fde; 160 break; 161 } 162 } 163 } 164 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared()); 165 return result; 166 } 167 168 template <typename A> 169 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end, 170 pint_t fde) { 171 #if !defined(_LIBUNWIND_NO_HEAP) 172 _LIBUNWIND_LOG_IF_FALSE(_lock.lock()); 173 if (_bufferUsed >= _bufferEnd) { 174 size_t oldSize = (size_t)(_bufferEnd - _buffer); 175 size_t newSize = oldSize * 4; 176 // Can't use operator new (we are below it). 177 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry)); 178 memcpy(newBuffer, _buffer, oldSize * sizeof(entry)); 179 if (_buffer != _initialBuffer) 180 free(_buffer); 181 _buffer = newBuffer; 182 _bufferUsed = &newBuffer[oldSize]; 183 _bufferEnd = &newBuffer[newSize]; 184 } 185 _bufferUsed->mh = mh; 186 _bufferUsed->ip_start = ip_start; 187 _bufferUsed->ip_end = ip_end; 188 _bufferUsed->fde = fde; 189 ++_bufferUsed; 190 #ifdef __APPLE__ 191 if (!_registeredForDyldUnloads) { 192 _dyld_register_func_for_remove_image(&dyldUnloadHook); 193 _registeredForDyldUnloads = true; 194 } 195 #endif 196 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock()); 197 #endif 198 } 199 200 template <typename A> 201 void DwarfFDECache<A>::removeAllIn(pint_t mh) { 202 _LIBUNWIND_LOG_IF_FALSE(_lock.lock()); 203 entry *d = _buffer; 204 for (const entry *s = _buffer; s < _bufferUsed; ++s) { 205 if (s->mh != mh) { 206 if (d != s) 207 *d = *s; 208 ++d; 209 } 210 } 211 _bufferUsed = d; 212 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock()); 213 } 214 215 #ifdef __APPLE__ 216 template <typename A> 217 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) { 218 removeAllIn((pint_t) mh); 219 } 220 #endif 221 222 template <typename A> 223 void DwarfFDECache<A>::iterateCacheEntries(void (*func)( 224 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) { 225 _LIBUNWIND_LOG_IF_FALSE(_lock.lock()); 226 for (entry *p = _buffer; p < _bufferUsed; ++p) { 227 (*func)(p->ip_start, p->ip_end, p->fde, p->mh); 228 } 229 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock()); 230 } 231 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 232 233 #define arrayoffsetof(type, index, field) \ 234 (sizeof(type) * (index) + offsetof(type, field)) 235 236 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 237 template <typename A> class UnwindSectionHeader { 238 public: 239 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr) 240 : _addressSpace(addressSpace), _addr(addr) {} 241 242 uint32_t version() const { 243 return _addressSpace.get32(_addr + 244 offsetof(unwind_info_section_header, version)); 245 } 246 uint32_t commonEncodingsArraySectionOffset() const { 247 return _addressSpace.get32(_addr + 248 offsetof(unwind_info_section_header, 249 commonEncodingsArraySectionOffset)); 250 } 251 uint32_t commonEncodingsArrayCount() const { 252 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 253 commonEncodingsArrayCount)); 254 } 255 uint32_t personalityArraySectionOffset() const { 256 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header, 257 personalityArraySectionOffset)); 258 } 259 uint32_t personalityArrayCount() const { 260 return _addressSpace.get32( 261 _addr + offsetof(unwind_info_section_header, personalityArrayCount)); 262 } 263 uint32_t indexSectionOffset() const { 264 return _addressSpace.get32( 265 _addr + offsetof(unwind_info_section_header, indexSectionOffset)); 266 } 267 uint32_t indexCount() const { 268 return _addressSpace.get32( 269 _addr + offsetof(unwind_info_section_header, indexCount)); 270 } 271 272 private: 273 A &_addressSpace; 274 typename A::pint_t _addr; 275 }; 276 277 template <typename A> class UnwindSectionIndexArray { 278 public: 279 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr) 280 : _addressSpace(addressSpace), _addr(addr) {} 281 282 uint32_t functionOffset(uint32_t index) const { 283 return _addressSpace.get32( 284 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 285 functionOffset)); 286 } 287 uint32_t secondLevelPagesSectionOffset(uint32_t index) const { 288 return _addressSpace.get32( 289 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 290 secondLevelPagesSectionOffset)); 291 } 292 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const { 293 return _addressSpace.get32( 294 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index, 295 lsdaIndexArraySectionOffset)); 296 } 297 298 private: 299 A &_addressSpace; 300 typename A::pint_t _addr; 301 }; 302 303 template <typename A> class UnwindSectionRegularPageHeader { 304 public: 305 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr) 306 : _addressSpace(addressSpace), _addr(addr) {} 307 308 uint32_t kind() const { 309 return _addressSpace.get32( 310 _addr + offsetof(unwind_info_regular_second_level_page_header, kind)); 311 } 312 uint16_t entryPageOffset() const { 313 return _addressSpace.get16( 314 _addr + offsetof(unwind_info_regular_second_level_page_header, 315 entryPageOffset)); 316 } 317 uint16_t entryCount() const { 318 return _addressSpace.get16( 319 _addr + 320 offsetof(unwind_info_regular_second_level_page_header, entryCount)); 321 } 322 323 private: 324 A &_addressSpace; 325 typename A::pint_t _addr; 326 }; 327 328 template <typename A> class UnwindSectionRegularArray { 329 public: 330 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr) 331 : _addressSpace(addressSpace), _addr(addr) {} 332 333 uint32_t functionOffset(uint32_t index) const { 334 return _addressSpace.get32( 335 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index, 336 functionOffset)); 337 } 338 uint32_t encoding(uint32_t index) const { 339 return _addressSpace.get32( 340 _addr + 341 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding)); 342 } 343 344 private: 345 A &_addressSpace; 346 typename A::pint_t _addr; 347 }; 348 349 template <typename A> class UnwindSectionCompressedPageHeader { 350 public: 351 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr) 352 : _addressSpace(addressSpace), _addr(addr) {} 353 354 uint32_t kind() const { 355 return _addressSpace.get32( 356 _addr + 357 offsetof(unwind_info_compressed_second_level_page_header, kind)); 358 } 359 uint16_t entryPageOffset() const { 360 return _addressSpace.get16( 361 _addr + offsetof(unwind_info_compressed_second_level_page_header, 362 entryPageOffset)); 363 } 364 uint16_t entryCount() const { 365 return _addressSpace.get16( 366 _addr + 367 offsetof(unwind_info_compressed_second_level_page_header, entryCount)); 368 } 369 uint16_t encodingsPageOffset() const { 370 return _addressSpace.get16( 371 _addr + offsetof(unwind_info_compressed_second_level_page_header, 372 encodingsPageOffset)); 373 } 374 uint16_t encodingsCount() const { 375 return _addressSpace.get16( 376 _addr + offsetof(unwind_info_compressed_second_level_page_header, 377 encodingsCount)); 378 } 379 380 private: 381 A &_addressSpace; 382 typename A::pint_t _addr; 383 }; 384 385 template <typename A> class UnwindSectionCompressedArray { 386 public: 387 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr) 388 : _addressSpace(addressSpace), _addr(addr) {} 389 390 uint32_t functionOffset(uint32_t index) const { 391 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET( 392 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 393 } 394 uint16_t encodingIndex(uint32_t index) const { 395 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX( 396 _addressSpace.get32(_addr + index * sizeof(uint32_t))); 397 } 398 399 private: 400 A &_addressSpace; 401 typename A::pint_t _addr; 402 }; 403 404 template <typename A> class UnwindSectionLsdaArray { 405 public: 406 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr) 407 : _addressSpace(addressSpace), _addr(addr) {} 408 409 uint32_t functionOffset(uint32_t index) const { 410 return _addressSpace.get32( 411 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 412 index, functionOffset)); 413 } 414 uint32_t lsdaOffset(uint32_t index) const { 415 return _addressSpace.get32( 416 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry, 417 index, lsdaOffset)); 418 } 419 420 private: 421 A &_addressSpace; 422 typename A::pint_t _addr; 423 }; 424 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 425 426 class _LIBUNWIND_HIDDEN AbstractUnwindCursor { 427 public: 428 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20) 429 // This avoids an unnecessary dependency to libc++abi. 430 void operator delete(void *, size_t) {} 431 432 virtual ~AbstractUnwindCursor() {} 433 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); } 434 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); } 435 virtual void setReg(int, unw_word_t) { 436 _LIBUNWIND_ABORT("setReg not implemented"); 437 } 438 virtual bool validFloatReg(int) { 439 _LIBUNWIND_ABORT("validFloatReg not implemented"); 440 } 441 virtual unw_fpreg_t getFloatReg(int) { 442 _LIBUNWIND_ABORT("getFloatReg not implemented"); 443 } 444 virtual void setFloatReg(int, unw_fpreg_t) { 445 _LIBUNWIND_ABORT("setFloatReg not implemented"); 446 } 447 virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); } 448 virtual void getInfo(unw_proc_info_t *) { 449 _LIBUNWIND_ABORT("getInfo not implemented"); 450 } 451 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); } 452 virtual bool isSignalFrame() { 453 _LIBUNWIND_ABORT("isSignalFrame not implemented"); 454 } 455 virtual bool getFunctionName(char *, size_t, unw_word_t *) { 456 _LIBUNWIND_ABORT("getFunctionName not implemented"); 457 } 458 virtual void setInfoBasedOnIPRegister(bool = false) { 459 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented"); 460 } 461 virtual const char *getRegisterName(int) { 462 _LIBUNWIND_ABORT("getRegisterName not implemented"); 463 } 464 #ifdef __arm__ 465 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); } 466 #endif 467 468 #ifdef _AIX 469 virtual uintptr_t getDataRelBase() { 470 _LIBUNWIND_ABORT("getDataRelBase not implemented"); 471 } 472 #endif 473 474 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS) 475 virtual void *get_registers() { 476 _LIBUNWIND_ABORT("get_registers not implemented"); 477 } 478 #endif 479 }; 480 481 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32) 482 483 /// \c UnwindCursor contains all state (including all register values) during 484 /// an unwind. This is normally stack-allocated inside a unw_cursor_t. 485 template <typename A, typename R> 486 class UnwindCursor : public AbstractUnwindCursor { 487 typedef typename A::pint_t pint_t; 488 public: 489 UnwindCursor(unw_context_t *context, A &as); 490 UnwindCursor(CONTEXT *context, A &as); 491 UnwindCursor(A &as, void *threadArg); 492 virtual ~UnwindCursor() {} 493 virtual bool validReg(int); 494 virtual unw_word_t getReg(int); 495 virtual void setReg(int, unw_word_t); 496 virtual bool validFloatReg(int); 497 virtual unw_fpreg_t getFloatReg(int); 498 virtual void setFloatReg(int, unw_fpreg_t); 499 virtual int step(bool = false); 500 virtual void getInfo(unw_proc_info_t *); 501 virtual void jumpto(); 502 virtual bool isSignalFrame(); 503 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off); 504 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false); 505 virtual const char *getRegisterName(int num); 506 #ifdef __arm__ 507 virtual void saveVFPAsX(); 508 #endif 509 510 DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; } 511 void setDispatcherContext(DISPATCHER_CONTEXT *disp) { 512 _dispContext = *disp; 513 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData); 514 if (_dispContext.LanguageHandler) { 515 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality); 516 } else 517 _info.handler = 0; 518 } 519 520 // libunwind does not and should not depend on C++ library which means that we 521 // need our own definition of inline placement new. 522 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; } 523 524 private: 525 526 pint_t getLastPC() const { return _dispContext.ControlPc; } 527 void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; } 528 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) { 529 #ifdef __arm__ 530 // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit. 531 pc &= ~1U; 532 #endif 533 // If pc points exactly at the end of the range, we might resolve the 534 // next function instead. Decrement pc by 1 to fit inside the current 535 // function. 536 pc -= 1; 537 _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc, 538 &_dispContext.ImageBase, 539 _dispContext.HistoryTable); 540 *base = _dispContext.ImageBase; 541 return _dispContext.FunctionEntry; 542 } 543 bool getInfoFromSEH(pint_t pc); 544 int stepWithSEHData() { 545 _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER, 546 _dispContext.ImageBase, 547 _dispContext.ControlPc, 548 _dispContext.FunctionEntry, 549 _dispContext.ContextRecord, 550 &_dispContext.HandlerData, 551 &_dispContext.EstablisherFrame, 552 NULL); 553 // Update some fields of the unwind info now, since we have them. 554 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData); 555 if (_dispContext.LanguageHandler) { 556 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality); 557 } else 558 _info.handler = 0; 559 return UNW_STEP_SUCCESS; 560 } 561 562 A &_addressSpace; 563 unw_proc_info_t _info; 564 DISPATCHER_CONTEXT _dispContext; 565 CONTEXT _msContext; 566 UNWIND_HISTORY_TABLE _histTable; 567 bool _unwindInfoMissing; 568 }; 569 570 571 template <typename A, typename R> 572 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as) 573 : _addressSpace(as), _unwindInfoMissing(false) { 574 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit), 575 "UnwindCursor<> does not fit in unw_cursor_t"); 576 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)), 577 "UnwindCursor<> requires more alignment than unw_cursor_t"); 578 memset(&_info, 0, sizeof(_info)); 579 memset(&_histTable, 0, sizeof(_histTable)); 580 memset(&_dispContext, 0, sizeof(_dispContext)); 581 _dispContext.ContextRecord = &_msContext; 582 _dispContext.HistoryTable = &_histTable; 583 // Initialize MS context from ours. 584 R r(context); 585 RtlCaptureContext(&_msContext); 586 _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT; 587 #if defined(_LIBUNWIND_TARGET_X86_64) 588 _msContext.Rax = r.getRegister(UNW_X86_64_RAX); 589 _msContext.Rcx = r.getRegister(UNW_X86_64_RCX); 590 _msContext.Rdx = r.getRegister(UNW_X86_64_RDX); 591 _msContext.Rbx = r.getRegister(UNW_X86_64_RBX); 592 _msContext.Rsp = r.getRegister(UNW_X86_64_RSP); 593 _msContext.Rbp = r.getRegister(UNW_X86_64_RBP); 594 _msContext.Rsi = r.getRegister(UNW_X86_64_RSI); 595 _msContext.Rdi = r.getRegister(UNW_X86_64_RDI); 596 _msContext.R8 = r.getRegister(UNW_X86_64_R8); 597 _msContext.R9 = r.getRegister(UNW_X86_64_R9); 598 _msContext.R10 = r.getRegister(UNW_X86_64_R10); 599 _msContext.R11 = r.getRegister(UNW_X86_64_R11); 600 _msContext.R12 = r.getRegister(UNW_X86_64_R12); 601 _msContext.R13 = r.getRegister(UNW_X86_64_R13); 602 _msContext.R14 = r.getRegister(UNW_X86_64_R14); 603 _msContext.R15 = r.getRegister(UNW_X86_64_R15); 604 _msContext.Rip = r.getRegister(UNW_REG_IP); 605 union { 606 v128 v; 607 M128A m; 608 } t; 609 t.v = r.getVectorRegister(UNW_X86_64_XMM0); 610 _msContext.Xmm0 = t.m; 611 t.v = r.getVectorRegister(UNW_X86_64_XMM1); 612 _msContext.Xmm1 = t.m; 613 t.v = r.getVectorRegister(UNW_X86_64_XMM2); 614 _msContext.Xmm2 = t.m; 615 t.v = r.getVectorRegister(UNW_X86_64_XMM3); 616 _msContext.Xmm3 = t.m; 617 t.v = r.getVectorRegister(UNW_X86_64_XMM4); 618 _msContext.Xmm4 = t.m; 619 t.v = r.getVectorRegister(UNW_X86_64_XMM5); 620 _msContext.Xmm5 = t.m; 621 t.v = r.getVectorRegister(UNW_X86_64_XMM6); 622 _msContext.Xmm6 = t.m; 623 t.v = r.getVectorRegister(UNW_X86_64_XMM7); 624 _msContext.Xmm7 = t.m; 625 t.v = r.getVectorRegister(UNW_X86_64_XMM8); 626 _msContext.Xmm8 = t.m; 627 t.v = r.getVectorRegister(UNW_X86_64_XMM9); 628 _msContext.Xmm9 = t.m; 629 t.v = r.getVectorRegister(UNW_X86_64_XMM10); 630 _msContext.Xmm10 = t.m; 631 t.v = r.getVectorRegister(UNW_X86_64_XMM11); 632 _msContext.Xmm11 = t.m; 633 t.v = r.getVectorRegister(UNW_X86_64_XMM12); 634 _msContext.Xmm12 = t.m; 635 t.v = r.getVectorRegister(UNW_X86_64_XMM13); 636 _msContext.Xmm13 = t.m; 637 t.v = r.getVectorRegister(UNW_X86_64_XMM14); 638 _msContext.Xmm14 = t.m; 639 t.v = r.getVectorRegister(UNW_X86_64_XMM15); 640 _msContext.Xmm15 = t.m; 641 #elif defined(_LIBUNWIND_TARGET_ARM) 642 _msContext.R0 = r.getRegister(UNW_ARM_R0); 643 _msContext.R1 = r.getRegister(UNW_ARM_R1); 644 _msContext.R2 = r.getRegister(UNW_ARM_R2); 645 _msContext.R3 = r.getRegister(UNW_ARM_R3); 646 _msContext.R4 = r.getRegister(UNW_ARM_R4); 647 _msContext.R5 = r.getRegister(UNW_ARM_R5); 648 _msContext.R6 = r.getRegister(UNW_ARM_R6); 649 _msContext.R7 = r.getRegister(UNW_ARM_R7); 650 _msContext.R8 = r.getRegister(UNW_ARM_R8); 651 _msContext.R9 = r.getRegister(UNW_ARM_R9); 652 _msContext.R10 = r.getRegister(UNW_ARM_R10); 653 _msContext.R11 = r.getRegister(UNW_ARM_R11); 654 _msContext.R12 = r.getRegister(UNW_ARM_R12); 655 _msContext.Sp = r.getRegister(UNW_ARM_SP); 656 _msContext.Lr = r.getRegister(UNW_ARM_LR); 657 _msContext.Pc = r.getRegister(UNW_ARM_IP); 658 for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) { 659 union { 660 uint64_t w; 661 double d; 662 } d; 663 d.d = r.getFloatRegister(i); 664 _msContext.D[i - UNW_ARM_D0] = d.w; 665 } 666 #elif defined(_LIBUNWIND_TARGET_AARCH64) 667 for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i) 668 _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i); 669 _msContext.Sp = r.getRegister(UNW_REG_SP); 670 _msContext.Pc = r.getRegister(UNW_REG_IP); 671 for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i) 672 _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i); 673 #endif 674 } 675 676 template <typename A, typename R> 677 UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as) 678 : _addressSpace(as), _unwindInfoMissing(false) { 679 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit), 680 "UnwindCursor<> does not fit in unw_cursor_t"); 681 memset(&_info, 0, sizeof(_info)); 682 memset(&_histTable, 0, sizeof(_histTable)); 683 memset(&_dispContext, 0, sizeof(_dispContext)); 684 _dispContext.ContextRecord = &_msContext; 685 _dispContext.HistoryTable = &_histTable; 686 _msContext = *context; 687 } 688 689 690 template <typename A, typename R> 691 bool UnwindCursor<A, R>::validReg(int regNum) { 692 if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true; 693 #if defined(_LIBUNWIND_TARGET_X86_64) 694 if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_RIP) return true; 695 #elif defined(_LIBUNWIND_TARGET_ARM) 696 if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) || 697 regNum == UNW_ARM_RA_AUTH_CODE) 698 return true; 699 #elif defined(_LIBUNWIND_TARGET_AARCH64) 700 if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true; 701 #endif 702 return false; 703 } 704 705 template <typename A, typename R> 706 unw_word_t UnwindCursor<A, R>::getReg(int regNum) { 707 switch (regNum) { 708 #if defined(_LIBUNWIND_TARGET_X86_64) 709 case UNW_X86_64_RIP: 710 case UNW_REG_IP: return _msContext.Rip; 711 case UNW_X86_64_RAX: return _msContext.Rax; 712 case UNW_X86_64_RDX: return _msContext.Rdx; 713 case UNW_X86_64_RCX: return _msContext.Rcx; 714 case UNW_X86_64_RBX: return _msContext.Rbx; 715 case UNW_REG_SP: 716 case UNW_X86_64_RSP: return _msContext.Rsp; 717 case UNW_X86_64_RBP: return _msContext.Rbp; 718 case UNW_X86_64_RSI: return _msContext.Rsi; 719 case UNW_X86_64_RDI: return _msContext.Rdi; 720 case UNW_X86_64_R8: return _msContext.R8; 721 case UNW_X86_64_R9: return _msContext.R9; 722 case UNW_X86_64_R10: return _msContext.R10; 723 case UNW_X86_64_R11: return _msContext.R11; 724 case UNW_X86_64_R12: return _msContext.R12; 725 case UNW_X86_64_R13: return _msContext.R13; 726 case UNW_X86_64_R14: return _msContext.R14; 727 case UNW_X86_64_R15: return _msContext.R15; 728 #elif defined(_LIBUNWIND_TARGET_ARM) 729 case UNW_ARM_R0: return _msContext.R0; 730 case UNW_ARM_R1: return _msContext.R1; 731 case UNW_ARM_R2: return _msContext.R2; 732 case UNW_ARM_R3: return _msContext.R3; 733 case UNW_ARM_R4: return _msContext.R4; 734 case UNW_ARM_R5: return _msContext.R5; 735 case UNW_ARM_R6: return _msContext.R6; 736 case UNW_ARM_R7: return _msContext.R7; 737 case UNW_ARM_R8: return _msContext.R8; 738 case UNW_ARM_R9: return _msContext.R9; 739 case UNW_ARM_R10: return _msContext.R10; 740 case UNW_ARM_R11: return _msContext.R11; 741 case UNW_ARM_R12: return _msContext.R12; 742 case UNW_REG_SP: 743 case UNW_ARM_SP: return _msContext.Sp; 744 case UNW_ARM_LR: return _msContext.Lr; 745 case UNW_REG_IP: 746 case UNW_ARM_IP: return _msContext.Pc; 747 #elif defined(_LIBUNWIND_TARGET_AARCH64) 748 case UNW_REG_SP: return _msContext.Sp; 749 case UNW_REG_IP: return _msContext.Pc; 750 default: return _msContext.X[regNum - UNW_AARCH64_X0]; 751 #endif 752 } 753 _LIBUNWIND_ABORT("unsupported register"); 754 } 755 756 template <typename A, typename R> 757 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) { 758 switch (regNum) { 759 #if defined(_LIBUNWIND_TARGET_X86_64) 760 case UNW_X86_64_RIP: 761 case UNW_REG_IP: _msContext.Rip = value; break; 762 case UNW_X86_64_RAX: _msContext.Rax = value; break; 763 case UNW_X86_64_RDX: _msContext.Rdx = value; break; 764 case UNW_X86_64_RCX: _msContext.Rcx = value; break; 765 case UNW_X86_64_RBX: _msContext.Rbx = value; break; 766 case UNW_REG_SP: 767 case UNW_X86_64_RSP: _msContext.Rsp = value; break; 768 case UNW_X86_64_RBP: _msContext.Rbp = value; break; 769 case UNW_X86_64_RSI: _msContext.Rsi = value; break; 770 case UNW_X86_64_RDI: _msContext.Rdi = value; break; 771 case UNW_X86_64_R8: _msContext.R8 = value; break; 772 case UNW_X86_64_R9: _msContext.R9 = value; break; 773 case UNW_X86_64_R10: _msContext.R10 = value; break; 774 case UNW_X86_64_R11: _msContext.R11 = value; break; 775 case UNW_X86_64_R12: _msContext.R12 = value; break; 776 case UNW_X86_64_R13: _msContext.R13 = value; break; 777 case UNW_X86_64_R14: _msContext.R14 = value; break; 778 case UNW_X86_64_R15: _msContext.R15 = value; break; 779 #elif defined(_LIBUNWIND_TARGET_ARM) 780 case UNW_ARM_R0: _msContext.R0 = value; break; 781 case UNW_ARM_R1: _msContext.R1 = value; break; 782 case UNW_ARM_R2: _msContext.R2 = value; break; 783 case UNW_ARM_R3: _msContext.R3 = value; break; 784 case UNW_ARM_R4: _msContext.R4 = value; break; 785 case UNW_ARM_R5: _msContext.R5 = value; break; 786 case UNW_ARM_R6: _msContext.R6 = value; break; 787 case UNW_ARM_R7: _msContext.R7 = value; break; 788 case UNW_ARM_R8: _msContext.R8 = value; break; 789 case UNW_ARM_R9: _msContext.R9 = value; break; 790 case UNW_ARM_R10: _msContext.R10 = value; break; 791 case UNW_ARM_R11: _msContext.R11 = value; break; 792 case UNW_ARM_R12: _msContext.R12 = value; break; 793 case UNW_REG_SP: 794 case UNW_ARM_SP: _msContext.Sp = value; break; 795 case UNW_ARM_LR: _msContext.Lr = value; break; 796 case UNW_REG_IP: 797 case UNW_ARM_IP: _msContext.Pc = value; break; 798 #elif defined(_LIBUNWIND_TARGET_AARCH64) 799 case UNW_REG_SP: _msContext.Sp = value; break; 800 case UNW_REG_IP: _msContext.Pc = value; break; 801 case UNW_AARCH64_X0: 802 case UNW_AARCH64_X1: 803 case UNW_AARCH64_X2: 804 case UNW_AARCH64_X3: 805 case UNW_AARCH64_X4: 806 case UNW_AARCH64_X5: 807 case UNW_AARCH64_X6: 808 case UNW_AARCH64_X7: 809 case UNW_AARCH64_X8: 810 case UNW_AARCH64_X9: 811 case UNW_AARCH64_X10: 812 case UNW_AARCH64_X11: 813 case UNW_AARCH64_X12: 814 case UNW_AARCH64_X13: 815 case UNW_AARCH64_X14: 816 case UNW_AARCH64_X15: 817 case UNW_AARCH64_X16: 818 case UNW_AARCH64_X17: 819 case UNW_AARCH64_X18: 820 case UNW_AARCH64_X19: 821 case UNW_AARCH64_X20: 822 case UNW_AARCH64_X21: 823 case UNW_AARCH64_X22: 824 case UNW_AARCH64_X23: 825 case UNW_AARCH64_X24: 826 case UNW_AARCH64_X25: 827 case UNW_AARCH64_X26: 828 case UNW_AARCH64_X27: 829 case UNW_AARCH64_X28: 830 case UNW_AARCH64_FP: 831 case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break; 832 #endif 833 default: 834 _LIBUNWIND_ABORT("unsupported register"); 835 } 836 } 837 838 template <typename A, typename R> 839 bool UnwindCursor<A, R>::validFloatReg(int regNum) { 840 #if defined(_LIBUNWIND_TARGET_ARM) 841 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true; 842 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true; 843 #elif defined(_LIBUNWIND_TARGET_AARCH64) 844 if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true; 845 #else 846 (void)regNum; 847 #endif 848 return false; 849 } 850 851 template <typename A, typename R> 852 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) { 853 #if defined(_LIBUNWIND_TARGET_ARM) 854 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) { 855 union { 856 uint32_t w; 857 float f; 858 } d; 859 d.w = _msContext.S[regNum - UNW_ARM_S0]; 860 return d.f; 861 } 862 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) { 863 union { 864 uint64_t w; 865 double d; 866 } d; 867 d.w = _msContext.D[regNum - UNW_ARM_D0]; 868 return d.d; 869 } 870 _LIBUNWIND_ABORT("unsupported float register"); 871 #elif defined(_LIBUNWIND_TARGET_AARCH64) 872 return _msContext.V[regNum - UNW_AARCH64_V0].D[0]; 873 #else 874 (void)regNum; 875 _LIBUNWIND_ABORT("float registers unimplemented"); 876 #endif 877 } 878 879 template <typename A, typename R> 880 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) { 881 #if defined(_LIBUNWIND_TARGET_ARM) 882 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) { 883 union { 884 uint32_t w; 885 float f; 886 } d; 887 d.f = (float)value; 888 _msContext.S[regNum - UNW_ARM_S0] = d.w; 889 } 890 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) { 891 union { 892 uint64_t w; 893 double d; 894 } d; 895 d.d = value; 896 _msContext.D[regNum - UNW_ARM_D0] = d.w; 897 } 898 _LIBUNWIND_ABORT("unsupported float register"); 899 #elif defined(_LIBUNWIND_TARGET_AARCH64) 900 _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value; 901 #else 902 (void)regNum; 903 (void)value; 904 _LIBUNWIND_ABORT("float registers unimplemented"); 905 #endif 906 } 907 908 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() { 909 RtlRestoreContext(&_msContext, nullptr); 910 } 911 912 #ifdef __arm__ 913 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {} 914 #endif 915 916 template <typename A, typename R> 917 const char *UnwindCursor<A, R>::getRegisterName(int regNum) { 918 return R::getRegisterName(regNum); 919 } 920 921 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() { 922 return false; 923 } 924 925 #else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32) 926 927 /// UnwindCursor contains all state (including all register values) during 928 /// an unwind. This is normally stack allocated inside a unw_cursor_t. 929 template <typename A, typename R> 930 class UnwindCursor : public AbstractUnwindCursor{ 931 typedef typename A::pint_t pint_t; 932 public: 933 UnwindCursor(unw_context_t *context, A &as); 934 UnwindCursor(A &as, void *threadArg); 935 virtual ~UnwindCursor() {} 936 virtual bool validReg(int); 937 virtual unw_word_t getReg(int); 938 virtual void setReg(int, unw_word_t); 939 virtual bool validFloatReg(int); 940 virtual unw_fpreg_t getFloatReg(int); 941 virtual void setFloatReg(int, unw_fpreg_t); 942 virtual int step(bool stage2 = false); 943 virtual void getInfo(unw_proc_info_t *); 944 virtual void jumpto(); 945 virtual bool isSignalFrame(); 946 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off); 947 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false); 948 virtual const char *getRegisterName(int num); 949 #ifdef __arm__ 950 virtual void saveVFPAsX(); 951 #endif 952 953 #ifdef _AIX 954 virtual uintptr_t getDataRelBase(); 955 #endif 956 957 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS) 958 virtual void *get_registers() { return &_registers; } 959 #endif 960 961 // libunwind does not and should not depend on C++ library which means that we 962 // need our own definition of inline placement new. 963 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; } 964 965 private: 966 967 #if defined(_LIBUNWIND_ARM_EHABI) 968 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s); 969 970 int stepWithEHABI() { 971 size_t len = 0; 972 size_t off = 0; 973 // FIXME: Calling decode_eht_entry() here is violating the libunwind 974 // abstraction layer. 975 const uint32_t *ehtp = 976 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info), 977 &off, &len); 978 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) != 979 _URC_CONTINUE_UNWIND) 980 return UNW_STEP_END; 981 return UNW_STEP_SUCCESS; 982 } 983 #endif 984 985 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) 986 bool setInfoForSigReturn() { 987 R dummy; 988 return setInfoForSigReturn(dummy); 989 } 990 int stepThroughSigReturn() { 991 R dummy; 992 return stepThroughSigReturn(dummy); 993 } 994 bool isReadableAddr(const pint_t addr) const; 995 #if defined(_LIBUNWIND_TARGET_AARCH64) 996 bool setInfoForSigReturn(Registers_arm64 &); 997 int stepThroughSigReturn(Registers_arm64 &); 998 #endif 999 #if defined(_LIBUNWIND_TARGET_RISCV) 1000 bool setInfoForSigReturn(Registers_riscv &); 1001 int stepThroughSigReturn(Registers_riscv &); 1002 #endif 1003 #if defined(_LIBUNWIND_TARGET_S390X) 1004 bool setInfoForSigReturn(Registers_s390x &); 1005 int stepThroughSigReturn(Registers_s390x &); 1006 #endif 1007 template <typename Registers> bool setInfoForSigReturn(Registers &) { 1008 return false; 1009 } 1010 template <typename Registers> int stepThroughSigReturn(Registers &) { 1011 return UNW_STEP_END; 1012 } 1013 #elif defined(_LIBUNWIND_TARGET_HAIKU) 1014 bool setInfoForSigReturn(); 1015 int stepThroughSigReturn(); 1016 #endif 1017 1018 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1019 bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo, 1020 const typename CFI_Parser<A>::CIE_Info &cieInfo, 1021 pint_t pc, uintptr_t dso_base); 1022 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s, 1023 uint32_t fdeSectionOffsetHint=0); 1024 int stepWithDwarfFDE(bool stage2) { 1025 return DwarfInstructions<A, R>::stepWithDwarf( 1026 _addressSpace, (pint_t)this->getReg(UNW_REG_IP), 1027 (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2); 1028 } 1029 #endif 1030 1031 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1032 bool getInfoFromCompactEncodingSection(pint_t pc, 1033 const UnwindInfoSections §s); 1034 int stepWithCompactEncoding(bool stage2 = false) { 1035 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1036 if ( compactSaysUseDwarf() ) 1037 return stepWithDwarfFDE(stage2); 1038 #endif 1039 R dummy; 1040 return stepWithCompactEncoding(dummy); 1041 } 1042 1043 #if defined(_LIBUNWIND_TARGET_X86_64) 1044 int stepWithCompactEncoding(Registers_x86_64 &) { 1045 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding( 1046 _info.format, _info.start_ip, _addressSpace, _registers); 1047 } 1048 #endif 1049 1050 #if defined(_LIBUNWIND_TARGET_I386) 1051 int stepWithCompactEncoding(Registers_x86 &) { 1052 return CompactUnwinder_x86<A>::stepWithCompactEncoding( 1053 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers); 1054 } 1055 #endif 1056 1057 #if defined(_LIBUNWIND_TARGET_PPC) 1058 int stepWithCompactEncoding(Registers_ppc &) { 1059 return UNW_EINVAL; 1060 } 1061 #endif 1062 1063 #if defined(_LIBUNWIND_TARGET_PPC64) 1064 int stepWithCompactEncoding(Registers_ppc64 &) { 1065 return UNW_EINVAL; 1066 } 1067 #endif 1068 1069 1070 #if defined(_LIBUNWIND_TARGET_AARCH64) 1071 int stepWithCompactEncoding(Registers_arm64 &) { 1072 return CompactUnwinder_arm64<A>::stepWithCompactEncoding( 1073 _info.format, _info.start_ip, _addressSpace, _registers); 1074 } 1075 #endif 1076 1077 #if defined(_LIBUNWIND_TARGET_MIPS_O32) 1078 int stepWithCompactEncoding(Registers_mips_o32 &) { 1079 return UNW_EINVAL; 1080 } 1081 #endif 1082 1083 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI) 1084 int stepWithCompactEncoding(Registers_mips_newabi &) { 1085 return UNW_EINVAL; 1086 } 1087 #endif 1088 1089 #if defined(_LIBUNWIND_TARGET_LOONGARCH) 1090 int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; } 1091 #endif 1092 1093 #if defined(_LIBUNWIND_TARGET_SPARC) 1094 int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; } 1095 #endif 1096 1097 #if defined(_LIBUNWIND_TARGET_SPARC64) 1098 int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; } 1099 #endif 1100 1101 #if defined (_LIBUNWIND_TARGET_RISCV) 1102 int stepWithCompactEncoding(Registers_riscv &) { 1103 return UNW_EINVAL; 1104 } 1105 #endif 1106 1107 bool compactSaysUseDwarf(uint32_t *offset=NULL) const { 1108 R dummy; 1109 return compactSaysUseDwarf(dummy, offset); 1110 } 1111 1112 #if defined(_LIBUNWIND_TARGET_X86_64) 1113 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const { 1114 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) { 1115 if (offset) 1116 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET); 1117 return true; 1118 } 1119 return false; 1120 } 1121 #endif 1122 1123 #if defined(_LIBUNWIND_TARGET_I386) 1124 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const { 1125 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) { 1126 if (offset) 1127 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET); 1128 return true; 1129 } 1130 return false; 1131 } 1132 #endif 1133 1134 #if defined(_LIBUNWIND_TARGET_PPC) 1135 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const { 1136 return true; 1137 } 1138 #endif 1139 1140 #if defined(_LIBUNWIND_TARGET_PPC64) 1141 bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const { 1142 return true; 1143 } 1144 #endif 1145 1146 #if defined(_LIBUNWIND_TARGET_AARCH64) 1147 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const { 1148 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) { 1149 if (offset) 1150 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET); 1151 return true; 1152 } 1153 return false; 1154 } 1155 #endif 1156 1157 #if defined(_LIBUNWIND_TARGET_MIPS_O32) 1158 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const { 1159 return true; 1160 } 1161 #endif 1162 1163 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI) 1164 bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const { 1165 return true; 1166 } 1167 #endif 1168 1169 #if defined(_LIBUNWIND_TARGET_LOONGARCH) 1170 bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const { 1171 return true; 1172 } 1173 #endif 1174 1175 #if defined(_LIBUNWIND_TARGET_SPARC) 1176 bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; } 1177 #endif 1178 1179 #if defined(_LIBUNWIND_TARGET_SPARC64) 1180 bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const { 1181 return true; 1182 } 1183 #endif 1184 1185 #if defined (_LIBUNWIND_TARGET_RISCV) 1186 bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const { 1187 return true; 1188 } 1189 #endif 1190 1191 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1192 1193 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1194 compact_unwind_encoding_t dwarfEncoding() const { 1195 R dummy; 1196 return dwarfEncoding(dummy); 1197 } 1198 1199 #if defined(_LIBUNWIND_TARGET_X86_64) 1200 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const { 1201 return UNWIND_X86_64_MODE_DWARF; 1202 } 1203 #endif 1204 1205 #if defined(_LIBUNWIND_TARGET_I386) 1206 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const { 1207 return UNWIND_X86_MODE_DWARF; 1208 } 1209 #endif 1210 1211 #if defined(_LIBUNWIND_TARGET_PPC) 1212 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const { 1213 return 0; 1214 } 1215 #endif 1216 1217 #if defined(_LIBUNWIND_TARGET_PPC64) 1218 compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const { 1219 return 0; 1220 } 1221 #endif 1222 1223 #if defined(_LIBUNWIND_TARGET_AARCH64) 1224 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const { 1225 return UNWIND_ARM64_MODE_DWARF; 1226 } 1227 #endif 1228 1229 #if defined(_LIBUNWIND_TARGET_ARM) 1230 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const { 1231 return 0; 1232 } 1233 #endif 1234 1235 #if defined (_LIBUNWIND_TARGET_OR1K) 1236 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const { 1237 return 0; 1238 } 1239 #endif 1240 1241 #if defined (_LIBUNWIND_TARGET_HEXAGON) 1242 compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const { 1243 return 0; 1244 } 1245 #endif 1246 1247 #if defined (_LIBUNWIND_TARGET_MIPS_O32) 1248 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const { 1249 return 0; 1250 } 1251 #endif 1252 1253 #if defined (_LIBUNWIND_TARGET_MIPS_NEWABI) 1254 compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const { 1255 return 0; 1256 } 1257 #endif 1258 1259 #if defined(_LIBUNWIND_TARGET_LOONGARCH) 1260 compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const { 1261 return 0; 1262 } 1263 #endif 1264 1265 #if defined(_LIBUNWIND_TARGET_SPARC) 1266 compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; } 1267 #endif 1268 1269 #if defined(_LIBUNWIND_TARGET_SPARC64) 1270 compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const { 1271 return 0; 1272 } 1273 #endif 1274 1275 #if defined (_LIBUNWIND_TARGET_RISCV) 1276 compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const { 1277 return 0; 1278 } 1279 #endif 1280 1281 #if defined (_LIBUNWIND_TARGET_S390X) 1282 compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const { 1283 return 0; 1284 } 1285 #endif 1286 1287 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1288 1289 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 1290 // For runtime environments using SEH unwind data without Windows runtime 1291 // support. 1292 pint_t getLastPC() const { /* FIXME: Implement */ return 0; } 1293 void setLastPC(pint_t pc) { /* FIXME: Implement */ } 1294 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) { 1295 /* FIXME: Implement */ 1296 *base = 0; 1297 return nullptr; 1298 } 1299 bool getInfoFromSEH(pint_t pc); 1300 int stepWithSEHData() { /* FIXME: Implement */ return 0; } 1301 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 1302 1303 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND) 1304 bool getInfoFromTBTable(pint_t pc, R ®isters); 1305 int stepWithTBTable(pint_t pc, tbtable *TBTable, R ®isters, 1306 bool &isSignalFrame); 1307 int stepWithTBTableData() { 1308 return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)), 1309 reinterpret_cast<tbtable *>(_info.unwind_info), 1310 _registers, _isSignalFrame); 1311 } 1312 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND) 1313 1314 A &_addressSpace; 1315 R _registers; 1316 unw_proc_info_t _info; 1317 bool _unwindInfoMissing; 1318 bool _isSignalFrame; 1319 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \ 1320 defined(_LIBUNWIND_TARGET_HAIKU) 1321 bool _isSigReturn = false; 1322 #endif 1323 }; 1324 1325 1326 template <typename A, typename R> 1327 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as) 1328 : _addressSpace(as), _registers(context), _unwindInfoMissing(false), 1329 _isSignalFrame(false) { 1330 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit), 1331 "UnwindCursor<> does not fit in unw_cursor_t"); 1332 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)), 1333 "UnwindCursor<> requires more alignment than unw_cursor_t"); 1334 memset(&_info, 0, sizeof(_info)); 1335 } 1336 1337 template <typename A, typename R> 1338 UnwindCursor<A, R>::UnwindCursor(A &as, void *) 1339 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) { 1340 memset(&_info, 0, sizeof(_info)); 1341 // FIXME 1342 // fill in _registers from thread arg 1343 } 1344 1345 1346 template <typename A, typename R> 1347 bool UnwindCursor<A, R>::validReg(int regNum) { 1348 return _registers.validRegister(regNum); 1349 } 1350 1351 template <typename A, typename R> 1352 unw_word_t UnwindCursor<A, R>::getReg(int regNum) { 1353 return _registers.getRegister(regNum); 1354 } 1355 1356 template <typename A, typename R> 1357 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) { 1358 _registers.setRegister(regNum, (typename A::pint_t)value); 1359 } 1360 1361 template <typename A, typename R> 1362 bool UnwindCursor<A, R>::validFloatReg(int regNum) { 1363 return _registers.validFloatRegister(regNum); 1364 } 1365 1366 template <typename A, typename R> 1367 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) { 1368 return _registers.getFloatRegister(regNum); 1369 } 1370 1371 template <typename A, typename R> 1372 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) { 1373 _registers.setFloatRegister(regNum, value); 1374 } 1375 1376 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() { 1377 _registers.jumpto(); 1378 } 1379 1380 #ifdef __arm__ 1381 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() { 1382 _registers.saveVFPAsX(); 1383 } 1384 #endif 1385 1386 #ifdef _AIX 1387 template <typename A, typename R> 1388 uintptr_t UnwindCursor<A, R>::getDataRelBase() { 1389 return reinterpret_cast<uintptr_t>(_info.extra); 1390 } 1391 #endif 1392 1393 template <typename A, typename R> 1394 const char *UnwindCursor<A, R>::getRegisterName(int regNum) { 1395 return _registers.getRegisterName(regNum); 1396 } 1397 1398 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() { 1399 return _isSignalFrame; 1400 } 1401 1402 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 1403 1404 #if defined(_LIBUNWIND_ARM_EHABI) 1405 template<typename A> 1406 struct EHABISectionIterator { 1407 typedef EHABISectionIterator _Self; 1408 1409 typedef typename A::pint_t value_type; 1410 typedef typename A::pint_t* pointer; 1411 typedef typename A::pint_t& reference; 1412 typedef size_t size_type; 1413 typedef size_t difference_type; 1414 1415 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) { 1416 return _Self(addressSpace, sects, 0); 1417 } 1418 static _Self end(A& addressSpace, const UnwindInfoSections& sects) { 1419 return _Self(addressSpace, sects, 1420 sects.arm_section_length / sizeof(EHABIIndexEntry)); 1421 } 1422 1423 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i) 1424 : _i(i), _addressSpace(&addressSpace), _sects(§s) {} 1425 1426 _Self& operator++() { ++_i; return *this; } 1427 _Self& operator+=(size_t a) { _i += a; return *this; } 1428 _Self& operator--() { assert(_i > 0); --_i; return *this; } 1429 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; } 1430 1431 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; } 1432 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; } 1433 1434 size_t operator-(const _Self& other) const { return _i - other._i; } 1435 1436 bool operator==(const _Self& other) const { 1437 assert(_addressSpace == other._addressSpace); 1438 assert(_sects == other._sects); 1439 return _i == other._i; 1440 } 1441 1442 bool operator!=(const _Self& other) const { 1443 assert(_addressSpace == other._addressSpace); 1444 assert(_sects == other._sects); 1445 return _i != other._i; 1446 } 1447 1448 typename A::pint_t operator*() const { return functionAddress(); } 1449 1450 typename A::pint_t functionAddress() const { 1451 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 1452 EHABIIndexEntry, _i, functionOffset); 1453 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr)); 1454 } 1455 1456 typename A::pint_t dataAddress() { 1457 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof( 1458 EHABIIndexEntry, _i, data); 1459 return indexAddr; 1460 } 1461 1462 private: 1463 size_t _i; 1464 A* _addressSpace; 1465 const UnwindInfoSections* _sects; 1466 }; 1467 1468 namespace { 1469 1470 template <typename A> 1471 EHABISectionIterator<A> EHABISectionUpperBound( 1472 EHABISectionIterator<A> first, 1473 EHABISectionIterator<A> last, 1474 typename A::pint_t value) { 1475 size_t len = last - first; 1476 while (len > 0) { 1477 size_t l2 = len / 2; 1478 EHABISectionIterator<A> m = first + l2; 1479 if (value < *m) { 1480 len = l2; 1481 } else { 1482 first = ++m; 1483 len -= l2 + 1; 1484 } 1485 } 1486 return first; 1487 } 1488 1489 } 1490 1491 template <typename A, typename R> 1492 bool UnwindCursor<A, R>::getInfoFromEHABISection( 1493 pint_t pc, 1494 const UnwindInfoSections §s) { 1495 EHABISectionIterator<A> begin = 1496 EHABISectionIterator<A>::begin(_addressSpace, sects); 1497 EHABISectionIterator<A> end = 1498 EHABISectionIterator<A>::end(_addressSpace, sects); 1499 if (begin == end) 1500 return false; 1501 1502 EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc); 1503 if (itNextPC == begin) 1504 return false; 1505 EHABISectionIterator<A> itThisPC = itNextPC - 1; 1506 1507 pint_t thisPC = itThisPC.functionAddress(); 1508 // If an exception is thrown from a function, corresponding to the last entry 1509 // in the table, we don't really know the function extent and have to choose a 1510 // value for nextPC. Choosing max() will allow the range check during trace to 1511 // succeed. 1512 pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress(); 1513 pint_t indexDataAddr = itThisPC.dataAddress(); 1514 1515 if (indexDataAddr == 0) 1516 return false; 1517 1518 uint32_t indexData = _addressSpace.get32(indexDataAddr); 1519 if (indexData == UNW_EXIDX_CANTUNWIND) 1520 return false; 1521 1522 // If the high bit is set, the exception handling table entry is inline inside 1523 // the index table entry on the second word (aka |indexDataAddr|). Otherwise, 1524 // the table points at an offset in the exception handling table (section 5 1525 // EHABI). 1526 pint_t exceptionTableAddr; 1527 uint32_t exceptionTableData; 1528 bool isSingleWordEHT; 1529 if (indexData & 0x80000000) { 1530 exceptionTableAddr = indexDataAddr; 1531 // TODO(ajwong): Should this data be 0? 1532 exceptionTableData = indexData; 1533 isSingleWordEHT = true; 1534 } else { 1535 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData); 1536 exceptionTableData = _addressSpace.get32(exceptionTableAddr); 1537 isSingleWordEHT = false; 1538 } 1539 1540 // Now we know the 3 things: 1541 // exceptionTableAddr -- exception handler table entry. 1542 // exceptionTableData -- the data inside the first word of the eht entry. 1543 // isSingleWordEHT -- whether the entry is in the index. 1544 unw_word_t personalityRoutine = 0xbadf00d; 1545 bool scope32 = false; 1546 uintptr_t lsda; 1547 1548 // If the high bit in the exception handling table entry is set, the entry is 1549 // in compact form (section 6.3 EHABI). 1550 if (exceptionTableData & 0x80000000) { 1551 // Grab the index of the personality routine from the compact form. 1552 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24; 1553 uint32_t extraWords = 0; 1554 switch (choice) { 1555 case 0: 1556 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0; 1557 extraWords = 0; 1558 scope32 = false; 1559 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4); 1560 break; 1561 case 1: 1562 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1; 1563 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 1564 scope32 = false; 1565 lsda = exceptionTableAddr + (extraWords + 1) * 4; 1566 break; 1567 case 2: 1568 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2; 1569 extraWords = (exceptionTableData & 0x00ff0000) >> 16; 1570 scope32 = true; 1571 lsda = exceptionTableAddr + (extraWords + 1) * 4; 1572 break; 1573 default: 1574 _LIBUNWIND_ABORT("unknown personality routine"); 1575 return false; 1576 } 1577 1578 if (isSingleWordEHT) { 1579 if (extraWords != 0) { 1580 _LIBUNWIND_ABORT("index inlined table detected but pr function " 1581 "requires extra words"); 1582 return false; 1583 } 1584 } 1585 } else { 1586 pint_t personalityAddr = 1587 exceptionTableAddr + signExtendPrel31(exceptionTableData); 1588 personalityRoutine = personalityAddr; 1589 1590 // ARM EHABI # 6.2, # 9.2 1591 // 1592 // +---- ehtp 1593 // v 1594 // +--------------------------------------+ 1595 // | +--------+--------+--------+-------+ | 1596 // | |0| prel31 to personalityRoutine | | 1597 // | +--------+--------+--------+-------+ | 1598 // | | N | unwind opcodes | | <-- UnwindData 1599 // | +--------+--------+--------+-------+ | 1600 // | | Word 2 unwind opcodes | | 1601 // | +--------+--------+--------+-------+ | 1602 // | ... | 1603 // | +--------+--------+--------+-------+ | 1604 // | | Word N unwind opcodes | | 1605 // | +--------+--------+--------+-------+ | 1606 // | | LSDA | | <-- lsda 1607 // | | ... | | 1608 // | +--------+--------+--------+-------+ | 1609 // +--------------------------------------+ 1610 1611 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1; 1612 uint32_t FirstDataWord = *UnwindData; 1613 size_t N = ((FirstDataWord >> 24) & 0xff); 1614 size_t NDataWords = N + 1; 1615 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords); 1616 } 1617 1618 _info.start_ip = thisPC; 1619 _info.end_ip = nextPC; 1620 _info.handler = personalityRoutine; 1621 _info.unwind_info = exceptionTableAddr; 1622 _info.lsda = lsda; 1623 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0. 1624 _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum? 1625 1626 return true; 1627 } 1628 #endif 1629 1630 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1631 template <typename A, typename R> 1632 bool UnwindCursor<A, R>::getInfoFromFdeCie( 1633 const typename CFI_Parser<A>::FDE_Info &fdeInfo, 1634 const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc, 1635 uintptr_t dso_base) { 1636 typename CFI_Parser<A>::PrologInfo prolog; 1637 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc, 1638 R::getArch(), &prolog)) { 1639 // Save off parsed FDE info 1640 _info.start_ip = fdeInfo.pcStart; 1641 _info.end_ip = fdeInfo.pcEnd; 1642 _info.lsda = fdeInfo.lsda; 1643 _info.handler = cieInfo.personality; 1644 // Some frameless functions need SP altered when resuming in function, so 1645 // propagate spExtraArgSize. 1646 _info.gp = prolog.spExtraArgSize; 1647 _info.flags = 0; 1648 _info.format = dwarfEncoding(); 1649 _info.unwind_info = fdeInfo.fdeStart; 1650 _info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength); 1651 _info.extra = static_cast<unw_word_t>(dso_base); 1652 return true; 1653 } 1654 return false; 1655 } 1656 1657 template <typename A, typename R> 1658 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc, 1659 const UnwindInfoSections §s, 1660 uint32_t fdeSectionOffsetHint) { 1661 typename CFI_Parser<A>::FDE_Info fdeInfo; 1662 typename CFI_Parser<A>::CIE_Info cieInfo; 1663 bool foundFDE = false; 1664 bool foundInCache = false; 1665 // If compact encoding table gave offset into dwarf section, go directly there 1666 if (fdeSectionOffsetHint != 0) { 1667 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 1668 sects.dwarf_section_length, 1669 sects.dwarf_section + fdeSectionOffsetHint, 1670 &fdeInfo, &cieInfo); 1671 } 1672 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 1673 if (!foundFDE && (sects.dwarf_index_section != 0)) { 1674 foundFDE = EHHeaderParser<A>::findFDE( 1675 _addressSpace, pc, sects.dwarf_index_section, 1676 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo); 1677 } 1678 #endif 1679 if (!foundFDE) { 1680 // otherwise, search cache of previously found FDEs. 1681 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc); 1682 if (cachedFDE != 0) { 1683 foundFDE = 1684 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 1685 sects.dwarf_section_length, 1686 cachedFDE, &fdeInfo, &cieInfo); 1687 foundInCache = foundFDE; 1688 } 1689 } 1690 if (!foundFDE) { 1691 // Still not found, do full scan of __eh_frame section. 1692 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section, 1693 sects.dwarf_section_length, 0, 1694 &fdeInfo, &cieInfo); 1695 } 1696 if (foundFDE) { 1697 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) { 1698 // Add to cache (to make next lookup faster) if we had no hint 1699 // and there was no index. 1700 if (!foundInCache && (fdeSectionOffsetHint == 0)) { 1701 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) 1702 if (sects.dwarf_index_section == 0) 1703 #endif 1704 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd, 1705 fdeInfo.fdeStart); 1706 } 1707 return true; 1708 } 1709 } 1710 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc); 1711 return false; 1712 } 1713 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 1714 1715 1716 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1717 template <typename A, typename R> 1718 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc, 1719 const UnwindInfoSections §s) { 1720 const bool log = false; 1721 if (log) 1722 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n", 1723 (uint64_t)pc, (uint64_t)sects.dso_base); 1724 1725 const UnwindSectionHeader<A> sectionHeader(_addressSpace, 1726 sects.compact_unwind_section); 1727 if (sectionHeader.version() != UNWIND_SECTION_VERSION) 1728 return false; 1729 1730 // do a binary search of top level index to find page with unwind info 1731 pint_t targetFunctionOffset = pc - sects.dso_base; 1732 const UnwindSectionIndexArray<A> topIndex(_addressSpace, 1733 sects.compact_unwind_section 1734 + sectionHeader.indexSectionOffset()); 1735 uint32_t low = 0; 1736 uint32_t high = sectionHeader.indexCount(); 1737 uint32_t last = high - 1; 1738 while (low < high) { 1739 uint32_t mid = (low + high) / 2; 1740 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n", 1741 //mid, low, high, topIndex.functionOffset(mid)); 1742 if (topIndex.functionOffset(mid) <= targetFunctionOffset) { 1743 if ((mid == last) || 1744 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) { 1745 low = mid; 1746 break; 1747 } else { 1748 low = mid + 1; 1749 } 1750 } else { 1751 high = mid; 1752 } 1753 } 1754 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low); 1755 const uint32_t firstLevelNextPageFunctionOffset = 1756 topIndex.functionOffset(low + 1); 1757 const pint_t secondLevelAddr = 1758 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low); 1759 const pint_t lsdaArrayStartAddr = 1760 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low); 1761 const pint_t lsdaArrayEndAddr = 1762 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1); 1763 if (log) 1764 fprintf(stderr, "\tfirst level search for result index=%d " 1765 "to secondLevelAddr=0x%llX\n", 1766 low, (uint64_t) secondLevelAddr); 1767 // do a binary search of second level page index 1768 uint32_t encoding = 0; 1769 pint_t funcStart = 0; 1770 pint_t funcEnd = 0; 1771 pint_t lsda = 0; 1772 pint_t personality = 0; 1773 uint32_t pageKind = _addressSpace.get32(secondLevelAddr); 1774 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) { 1775 // regular page 1776 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace, 1777 secondLevelAddr); 1778 UnwindSectionRegularArray<A> pageIndex( 1779 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 1780 // binary search looks for entry with e where index[e].offset <= pc < 1781 // index[e+1].offset 1782 if (log) 1783 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in " 1784 "regular page starting at secondLevelAddr=0x%llX\n", 1785 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr); 1786 low = 0; 1787 high = pageHeader.entryCount(); 1788 while (low < high) { 1789 uint32_t mid = (low + high) / 2; 1790 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) { 1791 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) { 1792 // at end of table 1793 low = mid; 1794 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 1795 break; 1796 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) { 1797 // next is too big, so we found it 1798 low = mid; 1799 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base; 1800 break; 1801 } else { 1802 low = mid + 1; 1803 } 1804 } else { 1805 high = mid; 1806 } 1807 } 1808 encoding = pageIndex.encoding(low); 1809 funcStart = pageIndex.functionOffset(low) + sects.dso_base; 1810 if (pc < funcStart) { 1811 if (log) 1812 fprintf( 1813 stderr, 1814 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 1815 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 1816 return false; 1817 } 1818 if (pc > funcEnd) { 1819 if (log) 1820 fprintf( 1821 stderr, 1822 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n", 1823 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd); 1824 return false; 1825 } 1826 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) { 1827 // compressed page 1828 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace, 1829 secondLevelAddr); 1830 UnwindSectionCompressedArray<A> pageIndex( 1831 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset()); 1832 const uint32_t targetFunctionPageOffset = 1833 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset); 1834 // binary search looks for entry with e where index[e].offset <= pc < 1835 // index[e+1].offset 1836 if (log) 1837 fprintf(stderr, "\tbinary search of compressed page starting at " 1838 "secondLevelAddr=0x%llX\n", 1839 (uint64_t) secondLevelAddr); 1840 low = 0; 1841 last = pageHeader.entryCount() - 1; 1842 high = pageHeader.entryCount(); 1843 while (low < high) { 1844 uint32_t mid = (low + high) / 2; 1845 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) { 1846 if ((mid == last) || 1847 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) { 1848 low = mid; 1849 break; 1850 } else { 1851 low = mid + 1; 1852 } 1853 } else { 1854 high = mid; 1855 } 1856 } 1857 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset 1858 + sects.dso_base; 1859 if (low < last) 1860 funcEnd = 1861 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset 1862 + sects.dso_base; 1863 else 1864 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base; 1865 if (pc < funcStart) { 1866 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX " 1867 "not in second level compressed unwind table. " 1868 "funcStart=0x%llX", 1869 (uint64_t) pc, (uint64_t) funcStart); 1870 return false; 1871 } 1872 if (pc > funcEnd) { 1873 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX " 1874 "not in second level compressed unwind table. " 1875 "funcEnd=0x%llX", 1876 (uint64_t) pc, (uint64_t) funcEnd); 1877 return false; 1878 } 1879 uint16_t encodingIndex = pageIndex.encodingIndex(low); 1880 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) { 1881 // encoding is in common table in section header 1882 encoding = _addressSpace.get32( 1883 sects.compact_unwind_section + 1884 sectionHeader.commonEncodingsArraySectionOffset() + 1885 encodingIndex * sizeof(uint32_t)); 1886 } else { 1887 // encoding is in page specific table 1888 uint16_t pageEncodingIndex = 1889 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount(); 1890 encoding = _addressSpace.get32(secondLevelAddr + 1891 pageHeader.encodingsPageOffset() + 1892 pageEncodingIndex * sizeof(uint32_t)); 1893 } 1894 } else { 1895 _LIBUNWIND_DEBUG_LOG( 1896 "malformed __unwind_info at 0x%0llX bad second level page", 1897 (uint64_t)sects.compact_unwind_section); 1898 return false; 1899 } 1900 1901 // look up LSDA, if encoding says function has one 1902 if (encoding & UNWIND_HAS_LSDA) { 1903 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr); 1904 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base); 1905 low = 0; 1906 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) / 1907 sizeof(unwind_info_section_header_lsda_index_entry); 1908 // binary search looks for entry with exact match for functionOffset 1909 if (log) 1910 fprintf(stderr, 1911 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n", 1912 funcStartOffset); 1913 while (low < high) { 1914 uint32_t mid = (low + high) / 2; 1915 if (lsdaIndex.functionOffset(mid) == funcStartOffset) { 1916 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base; 1917 break; 1918 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) { 1919 low = mid + 1; 1920 } else { 1921 high = mid; 1922 } 1923 } 1924 if (lsda == 0) { 1925 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for " 1926 "pc=0x%0llX, but lsda table has no entry", 1927 encoding, (uint64_t) pc); 1928 return false; 1929 } 1930 } 1931 1932 // extract personality routine, if encoding says function has one 1933 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >> 1934 (__builtin_ctz(UNWIND_PERSONALITY_MASK)); 1935 if (personalityIndex != 0) { 1936 --personalityIndex; // change 1-based to zero-based index 1937 if (personalityIndex >= sectionHeader.personalityArrayCount()) { 1938 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, " 1939 "but personality table has only %d entries", 1940 encoding, personalityIndex, 1941 sectionHeader.personalityArrayCount()); 1942 return false; 1943 } 1944 int32_t personalityDelta = (int32_t)_addressSpace.get32( 1945 sects.compact_unwind_section + 1946 sectionHeader.personalityArraySectionOffset() + 1947 personalityIndex * sizeof(uint32_t)); 1948 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta; 1949 personality = _addressSpace.getP(personalityPointer); 1950 if (log) 1951 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1952 "personalityDelta=0x%08X, personality=0x%08llX\n", 1953 (uint64_t) pc, personalityDelta, (uint64_t) personality); 1954 } 1955 1956 if (log) 1957 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), " 1958 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n", 1959 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart); 1960 _info.start_ip = funcStart; 1961 _info.end_ip = funcEnd; 1962 _info.lsda = lsda; 1963 _info.handler = personality; 1964 _info.gp = 0; 1965 _info.flags = 0; 1966 _info.format = encoding; 1967 _info.unwind_info = 0; 1968 _info.unwind_info_size = 0; 1969 _info.extra = sects.dso_base; 1970 return true; 1971 } 1972 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 1973 1974 1975 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 1976 template <typename A, typename R> 1977 bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) { 1978 pint_t base; 1979 RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base); 1980 if (!unwindEntry) { 1981 _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc); 1982 return false; 1983 } 1984 _info.gp = 0; 1985 _info.flags = 0; 1986 _info.format = 0; 1987 _info.unwind_info_size = sizeof(RUNTIME_FUNCTION); 1988 _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry); 1989 _info.extra = base; 1990 _info.start_ip = base + unwindEntry->BeginAddress; 1991 #ifdef _LIBUNWIND_TARGET_X86_64 1992 _info.end_ip = base + unwindEntry->EndAddress; 1993 // Only fill in the handler and LSDA if they're stale. 1994 if (pc != getLastPC()) { 1995 UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData); 1996 if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) { 1997 // The personality is given in the UNWIND_INFO itself. The LSDA immediately 1998 // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit 1999 // these structures.) 2000 // N.B. UNWIND_INFO structs are DWORD-aligned. 2001 uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1; 2002 const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]); 2003 _info.lsda = reinterpret_cast<unw_word_t>(handler+1); 2004 _dispContext.HandlerData = reinterpret_cast<void *>(_info.lsda); 2005 _dispContext.LanguageHandler = 2006 reinterpret_cast<EXCEPTION_ROUTINE *>(base + *handler); 2007 if (*handler) { 2008 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality); 2009 } else 2010 _info.handler = 0; 2011 } else { 2012 _info.lsda = 0; 2013 _info.handler = 0; 2014 } 2015 } 2016 #endif 2017 setLastPC(pc); 2018 return true; 2019 } 2020 #endif 2021 2022 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND) 2023 // Masks for traceback table field xtbtable. 2024 enum xTBTableMask : uint8_t { 2025 reservedBit = 0x02, // The traceback table was incorrectly generated if set 2026 // (see comments in function getInfoFromTBTable(). 2027 ehInfoBit = 0x08 // Exception handling info is present if set 2028 }; 2029 2030 enum frameType : unw_word_t { 2031 frameWithXLEHStateTable = 0, 2032 frameWithEHInfo = 1 2033 }; 2034 2035 extern "C" { 2036 typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action, 2037 uint64_t, 2038 _Unwind_Exception *, 2039 struct _Unwind_Context *); 2040 } 2041 2042 static __xlcxx_personality_v0_t *xlcPersonalityV0; 2043 static RWMutex xlcPersonalityV0InitLock; 2044 2045 template <typename A, typename R> 2046 bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R ®isters) { 2047 uint32_t *p = reinterpret_cast<uint32_t *>(pc); 2048 2049 // Keep looking forward until a word of 0 is found. The traceback 2050 // table starts at the following word. 2051 while (*p) 2052 ++p; 2053 tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1); 2054 2055 if (_LIBUNWIND_TRACING_UNWINDING) { 2056 char functionBuf[512]; 2057 const char *functionName = functionBuf; 2058 unw_word_t offset; 2059 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) { 2060 functionName = ".anonymous."; 2061 } 2062 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p", 2063 __func__, functionName, 2064 reinterpret_cast<void *>(TBTable)); 2065 } 2066 2067 // If the traceback table does not contain necessary info, bypass this frame. 2068 if (!TBTable->tb.has_tboff) 2069 return false; 2070 2071 // Structure tbtable_ext contains important data we are looking for. 2072 p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext); 2073 2074 // Skip field parminfo if it exists. 2075 if (TBTable->tb.fixedparms || TBTable->tb.floatparms) 2076 ++p; 2077 2078 // p now points to tb_offset, the offset from start of function to TB table. 2079 unw_word_t start_ip = 2080 reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t); 2081 unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable); 2082 ++p; 2083 2084 _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n", 2085 reinterpret_cast<void *>(start_ip), 2086 reinterpret_cast<void *>(end_ip)); 2087 2088 // Skip field hand_mask if it exists. 2089 if (TBTable->tb.int_hndl) 2090 ++p; 2091 2092 unw_word_t lsda = 0; 2093 unw_word_t handler = 0; 2094 unw_word_t flags = frameType::frameWithXLEHStateTable; 2095 2096 if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) { 2097 // State table info is available. The ctl_info field indicates the 2098 // number of CTL anchors. There should be only one entry for the C++ 2099 // state table. 2100 assert(*p == 1 && "libunwind: there must be only one ctl_info entry"); 2101 ++p; 2102 // p points to the offset of the state table into the stack. 2103 pint_t stateTableOffset = *p++; 2104 2105 int framePointerReg; 2106 2107 // Skip fields name_len and name if exist. 2108 if (TBTable->tb.name_present) { 2109 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p)); 2110 p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len + 2111 sizeof(uint16_t)); 2112 } 2113 2114 if (TBTable->tb.uses_alloca) 2115 framePointerReg = *(reinterpret_cast<char *>(p)); 2116 else 2117 framePointerReg = 1; // default frame pointer == SP 2118 2119 _LIBUNWIND_TRACE_UNWINDING( 2120 "framePointerReg=%d, framePointer=%p, " 2121 "stateTableOffset=%#lx\n", 2122 framePointerReg, 2123 reinterpret_cast<void *>(_registers.getRegister(framePointerReg)), 2124 stateTableOffset); 2125 lsda = _registers.getRegister(framePointerReg) + stateTableOffset; 2126 2127 // Since the traceback table generated by the legacy XLC++ does not 2128 // provide the location of the personality for the state table, 2129 // function __xlcxx_personality_v0(), which is the personality for the state 2130 // table and is exported from libc++abi, is directly assigned as the 2131 // handler here. When a legacy XLC++ frame is encountered, the symbol 2132 // is resolved dynamically using dlopen() to avoid a hard dependency of 2133 // libunwind on libc++abi in cases such as non-C++ applications. 2134 2135 // Resolve the function pointer to the state table personality if it has 2136 // not already been done. 2137 if (xlcPersonalityV0 == NULL) { 2138 xlcPersonalityV0InitLock.lock(); 2139 if (xlcPersonalityV0 == NULL) { 2140 // Resolve __xlcxx_personality_v0 using dlopen(). 2141 const char *libcxxabi = "libc++abi.a(libc++abi.so.1)"; 2142 void *libHandle; 2143 // The AIX dlopen() sets errno to 0 when it is successful, which 2144 // clobbers the value of errno from the user code. This is an AIX 2145 // bug because according to POSIX it should not set errno to 0. To 2146 // workaround before AIX fixes the bug, errno is saved and restored. 2147 int saveErrno = errno; 2148 libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW); 2149 if (libHandle == NULL) { 2150 _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n", errno); 2151 assert(0 && "dlopen() failed"); 2152 } 2153 xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>( 2154 dlsym(libHandle, "__xlcxx_personality_v0")); 2155 if (xlcPersonalityV0 == NULL) { 2156 _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno); 2157 dlclose(libHandle); 2158 assert(0 && "dlsym() failed"); 2159 } 2160 errno = saveErrno; 2161 } 2162 xlcPersonalityV0InitLock.unlock(); 2163 } 2164 handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0); 2165 _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n", 2166 reinterpret_cast<void *>(lsda), 2167 reinterpret_cast<void *>(handler)); 2168 } else if (TBTable->tb.longtbtable) { 2169 // This frame has the traceback table extension. Possible cases are 2170 // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that 2171 // is not EH aware; or, 3) a frame of other languages. We need to figure out 2172 // if the traceback table extension contains the 'eh_info' structure. 2173 // 2174 // We also need to deal with the complexity arising from some XL compiler 2175 // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits 2176 // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice 2177 // versa. For frames of code generated by those compilers, the 'longtbtable' 2178 // bit may be set but there isn't really a traceback table extension. 2179 // 2180 // In </usr/include/sys/debug.h>, there is the following definition of 2181 // 'struct tbtable_ext'. It is not really a structure but a dummy to 2182 // collect the description of optional parts of the traceback table. 2183 // 2184 // struct tbtable_ext { 2185 // ... 2186 // char alloca_reg; /* Register for alloca automatic storage */ 2187 // struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */ 2188 // unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/ 2189 // }; 2190 // 2191 // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data 2192 // following 'alloca_reg' can be treated either as 'struct vec_ext' or 2193 // 'unsigned char xtbtable'. 'xtbtable' bits are defined in 2194 // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently 2195 // unused and should not be set. 'struct vec_ext' is defined in 2196 // </usr/include/sys/debug.h> as follows: 2197 // 2198 // struct vec_ext { 2199 // unsigned vr_saved:6; /* Number of non-volatile vector regs saved 2200 // */ 2201 // /* first register saved is assumed to be */ 2202 // /* 32 - vr_saved */ 2203 // unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */ 2204 // unsigned has_varargs:1; 2205 // ... 2206 // }; 2207 // 2208 // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it 2209 // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg', 2210 // we checks if the 7th bit is set or not because 'xtbtable' should 2211 // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved 2212 // in the future to make sure the mitigation works. This mitigation 2213 // is not 100% bullet proof because 'struct vec_ext' may not always have 2214 // 'saves_vrsave' bit set. 2215 // 2216 // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for 2217 // checking the 7th bit. 2218 2219 // p points to field name len. 2220 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p); 2221 2222 // Skip fields name_len and name if they exist. 2223 if (TBTable->tb.name_present) { 2224 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr)); 2225 charPtr = charPtr + name_len + sizeof(uint16_t); 2226 } 2227 2228 // Skip field alloc_reg if it exists. 2229 if (TBTable->tb.uses_alloca) 2230 ++charPtr; 2231 2232 // Check traceback table bit has_vec. Skip struct vec_ext if it exists. 2233 if (TBTable->tb.has_vec) 2234 // Note struct vec_ext does exist at this point because whether the 2235 // ordering of longtbtable and has_vec bits is correct or not, both 2236 // are set. 2237 charPtr += sizeof(struct vec_ext); 2238 2239 // charPtr points to field 'xtbtable'. Check if the EH info is available. 2240 // Also check if the reserved bit of the extended traceback table field 2241 // 'xtbtable' is set. If it is, the traceback table was incorrectly 2242 // generated by an XL compiler that uses the wrong ordering of 'longtbtable' 2243 // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the 2244 // frame. 2245 if ((*charPtr & xTBTableMask::ehInfoBit) && 2246 !(*charPtr & xTBTableMask::reservedBit)) { 2247 // Mark this frame has the new EH info. 2248 flags = frameType::frameWithEHInfo; 2249 2250 // eh_info is available. 2251 charPtr++; 2252 // The pointer is 4-byte aligned. 2253 if (reinterpret_cast<uintptr_t>(charPtr) % 4) 2254 charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4; 2255 uintptr_t *ehInfo = 2256 reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>( 2257 registers.getRegister(2) + 2258 *(reinterpret_cast<uintptr_t *>(charPtr))))); 2259 2260 // ehInfo points to structure en_info. The first member is version. 2261 // Only version 0 is currently supported. 2262 assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 && 2263 "libunwind: ehInfo version other than 0 is not supported"); 2264 2265 // Increment ehInfo to point to member lsda. 2266 ++ehInfo; 2267 lsda = *ehInfo++; 2268 2269 // enInfo now points to member personality. 2270 handler = *ehInfo; 2271 2272 _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n", 2273 lsda, handler); 2274 } 2275 } 2276 2277 _info.start_ip = start_ip; 2278 _info.end_ip = end_ip; 2279 _info.lsda = lsda; 2280 _info.handler = handler; 2281 _info.gp = 0; 2282 _info.flags = flags; 2283 _info.format = 0; 2284 _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable); 2285 _info.unwind_info_size = 0; 2286 _info.extra = registers.getRegister(2); 2287 2288 return true; 2289 } 2290 2291 // Step back up the stack following the frame back link. 2292 template <typename A, typename R> 2293 int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable, 2294 R ®isters, bool &isSignalFrame) { 2295 if (_LIBUNWIND_TRACING_UNWINDING) { 2296 char functionBuf[512]; 2297 const char *functionName = functionBuf; 2298 unw_word_t offset; 2299 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) { 2300 functionName = ".anonymous."; 2301 } 2302 _LIBUNWIND_TRACE_UNWINDING( 2303 "%s: Look up traceback table of func=%s at %p, pc=%p, " 2304 "SP=%p, saves_lr=%d, stores_bc=%d", 2305 __func__, functionName, reinterpret_cast<void *>(TBTable), 2306 reinterpret_cast<void *>(pc), 2307 reinterpret_cast<void *>(registers.getSP()), TBTable->tb.saves_lr, 2308 TBTable->tb.stores_bc); 2309 } 2310 2311 #if defined(__powerpc64__) 2312 // Instruction to reload TOC register "ld r2,40(r1)" 2313 const uint32_t loadTOCRegInst = 0xe8410028; 2314 const int32_t unwPPCF0Index = UNW_PPC64_F0; 2315 const int32_t unwPPCV0Index = UNW_PPC64_V0; 2316 #else 2317 // Instruction to reload TOC register "lwz r2,20(r1)" 2318 const uint32_t loadTOCRegInst = 0x80410014; 2319 const int32_t unwPPCF0Index = UNW_PPC_F0; 2320 const int32_t unwPPCV0Index = UNW_PPC_V0; 2321 #endif 2322 2323 // lastStack points to the stack frame of the next routine up. 2324 pint_t curStack = static_cast<pint_t>(registers.getSP()); 2325 pint_t lastStack = *reinterpret_cast<pint_t *>(curStack); 2326 2327 if (lastStack == 0) 2328 return UNW_STEP_END; 2329 2330 R newRegisters = registers; 2331 2332 // If backchain is not stored, use the current stack frame. 2333 if (!TBTable->tb.stores_bc) 2334 lastStack = curStack; 2335 2336 // Return address is the address after call site instruction. 2337 pint_t returnAddress; 2338 2339 if (isSignalFrame) { 2340 _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p", 2341 reinterpret_cast<void *>(lastStack)); 2342 2343 sigcontext *sigContext = reinterpret_cast<sigcontext *>( 2344 reinterpret_cast<char *>(lastStack) + STKMINALIGN); 2345 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar; 2346 2347 bool useSTKMIN = false; 2348 if (returnAddress < 0x10000000) { 2349 // Try again using STKMIN. 2350 sigContext = reinterpret_cast<sigcontext *>( 2351 reinterpret_cast<char *>(lastStack) + STKMIN); 2352 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar; 2353 if (returnAddress < 0x10000000) { 2354 _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p from sigcontext=%p", 2355 reinterpret_cast<void *>(returnAddress), 2356 reinterpret_cast<void *>(sigContext)); 2357 return UNW_EBADFRAME; 2358 } 2359 useSTKMIN = true; 2360 } 2361 _LIBUNWIND_TRACE_UNWINDING("Returning from a signal handler %s: " 2362 "sigContext=%p, returnAddress=%p. " 2363 "Seems to be a valid address", 2364 useSTKMIN ? "STKMIN" : "STKMINALIGN", 2365 reinterpret_cast<void *>(sigContext), 2366 reinterpret_cast<void *>(returnAddress)); 2367 2368 // Restore the condition register from sigcontext. 2369 newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr); 2370 2371 // Save the LR in sigcontext for stepping up when the function that 2372 // raised the signal is a leaf function. This LR has the return address 2373 // to the caller of the leaf function. 2374 newRegisters.setLR(sigContext->sc_jmpbuf.jmp_context.lr); 2375 _LIBUNWIND_TRACE_UNWINDING( 2376 "Save LR=%p from sigcontext", 2377 reinterpret_cast<void *>(sigContext->sc_jmpbuf.jmp_context.lr)); 2378 2379 // Restore GPRs from sigcontext. 2380 for (int i = 0; i < 32; ++i) 2381 newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]); 2382 2383 // Restore FPRs from sigcontext. 2384 for (int i = 0; i < 32; ++i) 2385 newRegisters.setFloatRegister(i + unwPPCF0Index, 2386 sigContext->sc_jmpbuf.jmp_context.fpr[i]); 2387 2388 // Restore vector registers if there is an associated extended context 2389 // structure. 2390 if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) { 2391 ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext); 2392 if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) { 2393 for (int i = 0; i < 32; ++i) 2394 newRegisters.setVectorRegister( 2395 i + unwPPCV0Index, *(reinterpret_cast<v128 *>( 2396 &(uContext->__extctx->__vmx.__vr[i])))); 2397 } 2398 } 2399 } else { 2400 // Step up a normal frame. 2401 2402 if (!TBTable->tb.saves_lr && registers.getLR()) { 2403 // This case should only occur if we were called from a signal handler 2404 // and the signal occurred in a function that doesn't save the LR. 2405 returnAddress = static_cast<pint_t>(registers.getLR()); 2406 _LIBUNWIND_TRACE_UNWINDING("Use saved LR=%p", 2407 reinterpret_cast<void *>(returnAddress)); 2408 } else { 2409 // Otherwise, use the LR value in the stack link area. 2410 returnAddress = reinterpret_cast<pint_t *>(lastStack)[2]; 2411 } 2412 2413 // Reset LR in the current context. 2414 newRegisters.setLR(static_cast<uintptr_t>(NULL)); 2415 2416 _LIBUNWIND_TRACE_UNWINDING( 2417 "Extract info from lastStack=%p, returnAddress=%p", 2418 reinterpret_cast<void *>(lastStack), 2419 reinterpret_cast<void *>(returnAddress)); 2420 _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d", 2421 TBTable->tb.fpr_saved, TBTable->tb.gpr_saved, 2422 TBTable->tb.saves_cr); 2423 2424 // Restore FP registers. 2425 char *ptrToRegs = reinterpret_cast<char *>(lastStack); 2426 double *FPRegs = reinterpret_cast<double *>( 2427 ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double))); 2428 for (int i = 0; i < TBTable->tb.fpr_saved; ++i) 2429 newRegisters.setFloatRegister( 2430 32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]); 2431 2432 // Restore GP registers. 2433 ptrToRegs = reinterpret_cast<char *>(FPRegs); 2434 uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>( 2435 ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t))); 2436 for (int i = 0; i < TBTable->tb.gpr_saved; ++i) 2437 newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]); 2438 2439 // Restore Vector registers. 2440 ptrToRegs = reinterpret_cast<char *>(GPRegs); 2441 2442 // Restore vector registers only if this is a Clang frame. Also 2443 // check if traceback table bit has_vec is set. If it is, structure 2444 // vec_ext is available. 2445 if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) { 2446 2447 // Get to the vec_ext structure to check if vector registers are saved. 2448 uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext); 2449 2450 // Skip field parminfo if exists. 2451 if (TBTable->tb.fixedparms || TBTable->tb.floatparms) 2452 ++p; 2453 2454 // Skip field tb_offset if exists. 2455 if (TBTable->tb.has_tboff) 2456 ++p; 2457 2458 // Skip field hand_mask if exists. 2459 if (TBTable->tb.int_hndl) 2460 ++p; 2461 2462 // Skip fields ctl_info and ctl_info_disp if exist. 2463 if (TBTable->tb.has_ctl) { 2464 // Skip field ctl_info. 2465 ++p; 2466 // Skip field ctl_info_disp. 2467 ++p; 2468 } 2469 2470 // Skip fields name_len and name if exist. 2471 // p is supposed to point to field name_len now. 2472 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p); 2473 if (TBTable->tb.name_present) { 2474 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr)); 2475 charPtr = charPtr + name_len + sizeof(uint16_t); 2476 } 2477 2478 // Skip field alloc_reg if it exists. 2479 if (TBTable->tb.uses_alloca) 2480 ++charPtr; 2481 2482 struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr); 2483 2484 _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d", vec_ext->vr_saved); 2485 2486 // Restore vector register(s) if saved on the stack. 2487 if (vec_ext->vr_saved) { 2488 // Saved vector registers are 16-byte aligned. 2489 if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16) 2490 ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16; 2491 v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved * 2492 sizeof(v128)); 2493 for (int i = 0; i < vec_ext->vr_saved; ++i) { 2494 newRegisters.setVectorRegister( 2495 32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]); 2496 } 2497 } 2498 } 2499 if (TBTable->tb.saves_cr) { 2500 // Get the saved condition register. The condition register is only 2501 // a single word. 2502 newRegisters.setCR( 2503 *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t)))); 2504 } 2505 2506 // Restore the SP. 2507 newRegisters.setSP(lastStack); 2508 2509 // The first instruction after return. 2510 uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress)); 2511 2512 // Do we need to set the TOC register? 2513 _LIBUNWIND_TRACE_UNWINDING( 2514 "Current gpr2=%p", 2515 reinterpret_cast<void *>(newRegisters.getRegister(2))); 2516 if (firstInstruction == loadTOCRegInst) { 2517 _LIBUNWIND_TRACE_UNWINDING( 2518 "Set gpr2=%p from frame", 2519 reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5])); 2520 newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]); 2521 } 2522 } 2523 _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n", 2524 reinterpret_cast<void *>(lastStack), 2525 reinterpret_cast<void *>(returnAddress), 2526 reinterpret_cast<void *>(pc)); 2527 2528 // The return address is the address after call site instruction, so 2529 // setting IP to that simulates a return. 2530 newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress)); 2531 2532 // Simulate the step by replacing the register set with the new ones. 2533 registers = newRegisters; 2534 2535 // Check if the next frame is a signal frame. 2536 pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP())); 2537 2538 // Return address is the address after call site instruction. 2539 pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2]; 2540 2541 if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) { 2542 _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: " 2543 "nextStack=%p, next return address=%p\n", 2544 reinterpret_cast<void *>(nextStack), 2545 reinterpret_cast<void *>(nextReturnAddress)); 2546 isSignalFrame = true; 2547 } else { 2548 isSignalFrame = false; 2549 } 2550 return UNW_STEP_SUCCESS; 2551 } 2552 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND) 2553 2554 template <typename A, typename R> 2555 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) { 2556 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \ 2557 defined(_LIBUNWIND_TARGET_HAIKU) 2558 _isSigReturn = false; 2559 #endif 2560 2561 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP)); 2562 #if defined(_LIBUNWIND_ARM_EHABI) 2563 // Remove the thumb bit so the IP represents the actual instruction address. 2564 // This matches the behaviour of _Unwind_GetIP on arm. 2565 pc &= (pint_t)~0x1; 2566 #endif 2567 2568 // Exit early if at the top of the stack. 2569 if (pc == 0) { 2570 _unwindInfoMissing = true; 2571 return; 2572 } 2573 2574 // If the last line of a function is a "throw" the compiler sometimes 2575 // emits no instructions after the call to __cxa_throw. This means 2576 // the return address is actually the start of the next function. 2577 // To disambiguate this, back up the pc when we know it is a return 2578 // address. 2579 if (isReturnAddress) 2580 #if defined(_AIX) 2581 // PC needs to be a 4-byte aligned address to be able to look for a 2582 // word of 0 that indicates the start of the traceback table at the end 2583 // of a function on AIX. 2584 pc -= 4; 2585 #else 2586 --pc; 2587 #endif 2588 2589 #if !(defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)) && \ 2590 !defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND) 2591 // In case of this is frame of signal handler, the IP saved in the signal 2592 // handler points to first non-executed instruction, while FDE/CIE expects IP 2593 // to be after the first non-executed instruction. 2594 if (_isSignalFrame) 2595 ++pc; 2596 #endif 2597 2598 // Ask address space object to find unwind sections for this pc. 2599 UnwindInfoSections sects; 2600 if (_addressSpace.findUnwindSections(pc, sects)) { 2601 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 2602 // If there is a compact unwind encoding table, look there first. 2603 if (sects.compact_unwind_section != 0) { 2604 if (this->getInfoFromCompactEncodingSection(pc, sects)) { 2605 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 2606 // Found info in table, done unless encoding says to use dwarf. 2607 uint32_t dwarfOffset; 2608 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) { 2609 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) { 2610 // found info in dwarf, done 2611 return; 2612 } 2613 } 2614 #endif 2615 // If unwind table has entry, but entry says there is no unwind info, 2616 // record that we have no unwind info. 2617 if (_info.format == 0) 2618 _unwindInfoMissing = true; 2619 return; 2620 } 2621 } 2622 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 2623 2624 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 2625 // If there is SEH unwind info, look there next. 2626 if (this->getInfoFromSEH(pc)) 2627 return; 2628 #endif 2629 2630 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND) 2631 // If there is unwind info in the traceback table, look there next. 2632 if (this->getInfoFromTBTable(pc, _registers)) 2633 return; 2634 #endif 2635 2636 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 2637 // If there is dwarf unwind info, look there next. 2638 if (sects.dwarf_section != 0) { 2639 if (this->getInfoFromDwarfSection(pc, sects)) { 2640 // found info in dwarf, done 2641 return; 2642 } 2643 } 2644 #endif 2645 2646 #if defined(_LIBUNWIND_ARM_EHABI) 2647 // If there is ARM EHABI unwind info, look there next. 2648 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects)) 2649 return; 2650 #endif 2651 } 2652 2653 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 2654 // There is no static unwind info for this pc. Look to see if an FDE was 2655 // dynamically registered for it. 2656 pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll, 2657 pc); 2658 if (cachedFDE != 0) { 2659 typename CFI_Parser<A>::FDE_Info fdeInfo; 2660 typename CFI_Parser<A>::CIE_Info cieInfo; 2661 if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo)) 2662 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0)) 2663 return; 2664 } 2665 2666 // Lastly, ask AddressSpace object about platform specific ways to locate 2667 // other FDEs. 2668 pint_t fde; 2669 if (_addressSpace.findOtherFDE(pc, fde)) { 2670 typename CFI_Parser<A>::FDE_Info fdeInfo; 2671 typename CFI_Parser<A>::CIE_Info cieInfo; 2672 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) { 2673 // Double check this FDE is for a function that includes the pc. 2674 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) 2675 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0)) 2676 return; 2677 } 2678 } 2679 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 2680 2681 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \ 2682 defined(_LIBUNWIND_TARGET_HAIKU) 2683 if (setInfoForSigReturn()) 2684 return; 2685 #endif 2686 2687 // no unwind info, flag that we can't reliably unwind 2688 _unwindInfoMissing = true; 2689 } 2690 2691 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \ 2692 defined(_LIBUNWIND_TARGET_AARCH64) 2693 template <typename A, typename R> 2694 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) { 2695 // Look for the sigreturn trampoline. The trampoline's body is two 2696 // specific instructions (see below). Typically the trampoline comes from the 2697 // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its 2698 // own restorer function, though, or user-mode QEMU might write a trampoline 2699 // onto the stack. 2700 // 2701 // This special code path is a fallback that is only used if the trampoline 2702 // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register 2703 // constant for the PC needs to be defined before DWARF can handle a signal 2704 // trampoline. This code may segfault if the target PC is unreadable, e.g.: 2705 // - The PC points at a function compiled without unwind info, and which is 2706 // part of an execute-only mapping (e.g. using -Wl,--execute-only). 2707 // - The PC is invalid and happens to point to unreadable or unmapped memory. 2708 // 2709 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S 2710 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP)); 2711 // The PC might contain an invalid address if the unwind info is bad, so 2712 // directly accessing it could cause a SIGSEGV. 2713 if (!isReadableAddr(pc)) 2714 return false; 2715 auto *instructions = reinterpret_cast<const uint32_t *>(pc); 2716 // Look for instructions: mov x8, #0x8b; svc #0x0 2717 if (instructions[0] != 0xd2801168 || instructions[1] != 0xd4000001) 2718 return false; 2719 2720 _info = {}; 2721 _info.start_ip = pc; 2722 _info.end_ip = pc + 4; 2723 _isSigReturn = true; 2724 return true; 2725 } 2726 2727 template <typename A, typename R> 2728 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) { 2729 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is: 2730 // - 128-byte siginfo struct 2731 // - ucontext struct: 2732 // - 8-byte long (uc_flags) 2733 // - 8-byte pointer (uc_link) 2734 // - 24-byte stack_t 2735 // - 128-byte signal set 2736 // - 8 bytes of padding because sigcontext has 16-byte alignment 2737 // - sigcontext/mcontext_t 2738 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c 2739 const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304 2740 2741 // Offsets from sigcontext to each register. 2742 const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field 2743 const pint_t kOffsetSp = 256; // offset to "__u64 sp" field 2744 const pint_t kOffsetPc = 264; // offset to "__u64 pc" field 2745 2746 pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext; 2747 2748 for (int i = 0; i <= 30; ++i) { 2749 uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs + 2750 static_cast<pint_t>(i * 8)); 2751 _registers.setRegister(UNW_AARCH64_X0 + i, value); 2752 } 2753 _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp)); 2754 _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc)); 2755 _isSignalFrame = true; 2756 return UNW_STEP_SUCCESS; 2757 } 2758 2759 #elif defined(_LIBUNWIND_TARGET_HAIKU) && defined(_LIBUNWIND_TARGET_X86_64) 2760 #include <commpage_defs.h> 2761 #include <signal.h> 2762 2763 extern "C" { 2764 extern void *__gCommPageAddress; 2765 } 2766 2767 template <typename A, typename R> 2768 bool UnwindCursor<A, R>::setInfoForSigReturn() { 2769 #if defined(_LIBUNWIND_TARGET_X86_64) 2770 addr_t signal_handler = 2771 (((addr_t *)__gCommPageAddress)[COMMPAGE_ENTRY_X86_SIGNAL_HANDLER] + 2772 (addr_t)__gCommPageAddress); 2773 addr_t signal_handler_ret = signal_handler + 45; 2774 #endif 2775 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP)); 2776 if (pc == signal_handler_ret) { 2777 _info = {}; 2778 _info.start_ip = signal_handler; 2779 _info.end_ip = signal_handler_ret; 2780 _isSigReturn = true; 2781 return true; 2782 } 2783 return false; 2784 } 2785 2786 template <typename A, typename R> 2787 int UnwindCursor<A, R>::stepThroughSigReturn() { 2788 _isSignalFrame = true; 2789 pint_t sp = _registers.getSP(); 2790 #if defined(_LIBUNWIND_TARGET_X86_64) 2791 vregs *regs = (vregs *)(sp + 0x70); 2792 2793 _registers.setRegister(UNW_REG_IP, regs->rip); 2794 _registers.setRegister(UNW_REG_SP, regs->rsp); 2795 _registers.setRegister(UNW_X86_64_RAX, regs->rax); 2796 _registers.setRegister(UNW_X86_64_RDX, regs->rdx); 2797 _registers.setRegister(UNW_X86_64_RCX, regs->rcx); 2798 _registers.setRegister(UNW_X86_64_RBX, regs->rbx); 2799 _registers.setRegister(UNW_X86_64_RSI, regs->rsi); 2800 _registers.setRegister(UNW_X86_64_RDI, regs->rdi); 2801 _registers.setRegister(UNW_X86_64_RBP, regs->rbp); 2802 _registers.setRegister(UNW_X86_64_R8, regs->r8); 2803 _registers.setRegister(UNW_X86_64_R9, regs->r9); 2804 _registers.setRegister(UNW_X86_64_R10, regs->r10); 2805 _registers.setRegister(UNW_X86_64_R11, regs->r11); 2806 _registers.setRegister(UNW_X86_64_R12, regs->r12); 2807 _registers.setRegister(UNW_X86_64_R13, regs->r13); 2808 _registers.setRegister(UNW_X86_64_R14, regs->r14); 2809 _registers.setRegister(UNW_X86_64_R15, regs->r15); 2810 // TODO: XMM 2811 #endif 2812 2813 return UNW_STEP_SUCCESS; 2814 } 2815 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && 2816 // defined(_LIBUNWIND_TARGET_AARCH64) 2817 2818 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \ 2819 defined(_LIBUNWIND_TARGET_RISCV) 2820 template <typename A, typename R> 2821 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_riscv &) { 2822 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP)); 2823 // The PC might contain an invalid address if the unwind info is bad, so 2824 // directly accessing it could cause a SIGSEGV. 2825 if (!isReadableAddr(pc)) 2826 return false; 2827 const auto *instructions = reinterpret_cast<const uint32_t *>(pc); 2828 // Look for the two instructions used in the sigreturn trampoline 2829 // __vdso_rt_sigreturn: 2830 // 2831 // 0x08b00893 li a7,0x8b 2832 // 0x00000073 ecall 2833 if (instructions[0] != 0x08b00893 || instructions[1] != 0x00000073) 2834 return false; 2835 2836 _info = {}; 2837 _info.start_ip = pc; 2838 _info.end_ip = pc + 4; 2839 _isSigReturn = true; 2840 return true; 2841 } 2842 2843 template <typename A, typename R> 2844 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_riscv &) { 2845 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is: 2846 // - 128-byte siginfo struct 2847 // - ucontext_t struct: 2848 // - 8-byte long (__uc_flags) 2849 // - 8-byte pointer (*uc_link) 2850 // - 24-byte uc_stack 2851 // - 8-byte uc_sigmask 2852 // - 120-byte of padding to allow sigset_t to be expanded in the future 2853 // - 8 bytes of padding because sigcontext has 16-byte alignment 2854 // - struct sigcontext uc_mcontext 2855 // [1] 2856 // https://github.com/torvalds/linux/blob/master/arch/riscv/kernel/signal.c 2857 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128; 2858 2859 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext; 2860 _registers.setIP(_addressSpace.get64(sigctx)); 2861 for (int i = UNW_RISCV_X1; i <= UNW_RISCV_X31; ++i) { 2862 uint64_t value = _addressSpace.get64(sigctx + static_cast<pint_t>(i * 8)); 2863 _registers.setRegister(i, value); 2864 } 2865 _isSignalFrame = true; 2866 return UNW_STEP_SUCCESS; 2867 } 2868 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && 2869 // defined(_LIBUNWIND_TARGET_RISCV) 2870 2871 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \ 2872 defined(_LIBUNWIND_TARGET_S390X) 2873 template <typename A, typename R> 2874 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) { 2875 // Look for the sigreturn trampoline. The trampoline's body is a 2876 // specific instruction (see below). Typically the trampoline comes from the 2877 // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its 2878 // own restorer function, though, or user-mode QEMU might write a trampoline 2879 // onto the stack. 2880 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP)); 2881 // The PC might contain an invalid address if the unwind info is bad, so 2882 // directly accessing it could cause a SIGSEGV. 2883 if (!isReadableAddr(pc)) 2884 return false; 2885 const auto inst = *reinterpret_cast<const uint16_t *>(pc); 2886 if (inst == 0x0a77 || inst == 0x0aad) { 2887 _info = {}; 2888 _info.start_ip = pc; 2889 _info.end_ip = pc + 2; 2890 _isSigReturn = true; 2891 return true; 2892 } 2893 return false; 2894 } 2895 2896 template <typename A, typename R> 2897 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) { 2898 // Determine current SP. 2899 const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP)); 2900 // According to the s390x ABI, the CFA is at (incoming) SP + 160. 2901 const pint_t cfa = sp + 160; 2902 2903 // Determine current PC and instruction there (this must be either 2904 // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn"). 2905 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP)); 2906 const uint16_t inst = _addressSpace.get16(pc); 2907 2908 // Find the addresses of the signo and sigcontext in the frame. 2909 pint_t pSigctx = 0; 2910 pint_t pSigno = 0; 2911 2912 // "svc __NR_sigreturn" uses a non-RT signal trampoline frame. 2913 if (inst == 0x0a77) { 2914 // Layout of a non-RT signal trampoline frame, starting at the CFA: 2915 // - 8-byte signal mask 2916 // - 8-byte pointer to sigcontext, followed by signo 2917 // - 4-byte signo 2918 pSigctx = _addressSpace.get64(cfa + 8); 2919 pSigno = pSigctx + 344; 2920 } 2921 2922 // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame. 2923 if (inst == 0x0aad) { 2924 // Layout of a RT signal trampoline frame, starting at the CFA: 2925 // - 8-byte retcode (+ alignment) 2926 // - 128-byte siginfo struct (starts with signo) 2927 // - ucontext struct: 2928 // - 8-byte long (uc_flags) 2929 // - 8-byte pointer (uc_link) 2930 // - 24-byte stack_t 2931 // - 8 bytes of padding because sigcontext has 16-byte alignment 2932 // - sigcontext/mcontext_t 2933 pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8; 2934 pSigno = cfa + 8; 2935 } 2936 2937 assert(pSigctx != 0); 2938 assert(pSigno != 0); 2939 2940 // Offsets from sigcontext to each register. 2941 const pint_t kOffsetPc = 8; 2942 const pint_t kOffsetGprs = 16; 2943 const pint_t kOffsetFprs = 216; 2944 2945 // Restore all registers. 2946 for (int i = 0; i < 16; ++i) { 2947 uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs + 2948 static_cast<pint_t>(i * 8)); 2949 _registers.setRegister(UNW_S390X_R0 + i, value); 2950 } 2951 for (int i = 0; i < 16; ++i) { 2952 static const int fpr[16] = { 2953 UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3, 2954 UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7, 2955 UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11, 2956 UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15 2957 }; 2958 double value = _addressSpace.getDouble(pSigctx + kOffsetFprs + 2959 static_cast<pint_t>(i * 8)); 2960 _registers.setFloatRegister(fpr[i], value); 2961 } 2962 _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc)); 2963 2964 // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr 2965 // after the faulting instruction rather than before it. 2966 // Do not set _isSignalFrame in that case. 2967 uint32_t signo = _addressSpace.get32(pSigno); 2968 _isSignalFrame = (signo != 4 && signo != 5 && signo != 8); 2969 2970 return UNW_STEP_SUCCESS; 2971 } 2972 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && 2973 // defined(_LIBUNWIND_TARGET_S390X) 2974 2975 template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) { 2976 (void)stage2; 2977 // Bottom of stack is defined is when unwind info cannot be found. 2978 if (_unwindInfoMissing) 2979 return UNW_STEP_END; 2980 2981 // Use unwinding info to modify register set as if function returned. 2982 int result; 2983 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \ 2984 defined(_LIBUNWIND_TARGET_HAIKU) 2985 if (_isSigReturn) { 2986 result = this->stepThroughSigReturn(); 2987 } else 2988 #endif 2989 { 2990 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) 2991 result = this->stepWithCompactEncoding(stage2); 2992 #elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 2993 result = this->stepWithSEHData(); 2994 #elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND) 2995 result = this->stepWithTBTableData(); 2996 #elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 2997 result = this->stepWithDwarfFDE(stage2); 2998 #elif defined(_LIBUNWIND_ARM_EHABI) 2999 result = this->stepWithEHABI(); 3000 #else 3001 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \ 3002 _LIBUNWIND_SUPPORT_SEH_UNWIND or \ 3003 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \ 3004 _LIBUNWIND_ARM_EHABI 3005 #endif 3006 } 3007 3008 // update info based on new PC 3009 if (result == UNW_STEP_SUCCESS) { 3010 this->setInfoBasedOnIPRegister(true); 3011 if (_unwindInfoMissing) 3012 return UNW_STEP_END; 3013 } 3014 3015 return result; 3016 } 3017 3018 template <typename A, typename R> 3019 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) { 3020 if (_unwindInfoMissing) 3021 memset(info, 0, sizeof(*info)); 3022 else 3023 *info = _info; 3024 } 3025 3026 template <typename A, typename R> 3027 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen, 3028 unw_word_t *offset) { 3029 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP), 3030 buf, bufLen, offset); 3031 } 3032 3033 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) 3034 template <typename A, typename R> 3035 bool UnwindCursor<A, R>::isReadableAddr(const pint_t addr) const { 3036 // We use SYS_rt_sigprocmask, inspired by Abseil's AddressIsReadable. 3037 3038 const auto sigsetAddr = reinterpret_cast<sigset_t *>(addr); 3039 // We have to check that addr is nullptr because sigprocmask allows that 3040 // as an argument without failure. 3041 if (!sigsetAddr) 3042 return false; 3043 const auto saveErrno = errno; 3044 // We MUST use a raw syscall here, as wrappers may try to access 3045 // sigsetAddr which may cause a SIGSEGV. A raw syscall however is 3046 // safe. Additionally, we need to pass the kernel_sigset_size, which is 3047 // different from libc sizeof(sigset_t). For the majority of architectures, 3048 // it's 64 bits (_NSIG), and libc NSIG is _NSIG + 1. 3049 const auto kernelSigsetSize = NSIG / 8; 3050 [[maybe_unused]] const int Result = syscall( 3051 SYS_rt_sigprocmask, /*how=*/~0, sigsetAddr, nullptr, kernelSigsetSize); 3052 // Because our "how" is invalid, this syscall should always fail, and our 3053 // errno should always be EINVAL or an EFAULT. This relies on the Linux 3054 // kernel to check copy_from_user before checking if the "how" argument is 3055 // invalid. 3056 assert(Result == -1); 3057 assert(errno == EFAULT || errno == EINVAL); 3058 const auto readable = errno != EFAULT; 3059 errno = saveErrno; 3060 return readable; 3061 } 3062 #endif 3063 3064 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS) 3065 extern "C" void *__libunwind_cet_get_registers(unw_cursor_t *cursor) { 3066 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 3067 return co->get_registers(); 3068 } 3069 #endif 3070 } // namespace libunwind 3071 3072 #endif // __UNWINDCURSOR_HPP__ 3073