CoCalc -- UnwindCursor.hpp

GitHub Repository: emscripten-core/emscripten
Path: blob/main/system/lib/libunwind/src/UnwindCursor.hpp
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//
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// C++ interface to lower levels of libunwind
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//===----------------------------------------------------------------------===//
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#ifndef __UNWINDCURSOR_HPP__
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#define __UNWINDCURSOR_HPP__
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#include "shadow_stack_unwind.h"
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unwind.h>
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#ifdef _WIN32
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  #include <windows.h>
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  #include <ntverp.h>
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#endif
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#ifdef __APPLE__
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  #include <mach-o/dyld.h>
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#endif
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#ifdef _AIX
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#include <dlfcn.h>
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#include <sys/debug.h>
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#include <sys/pseg.h>
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#endif
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#if defined(_LIBUNWIND_TARGET_LINUX) &&                                        \
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    (defined(_LIBUNWIND_TARGET_AARCH64) ||                                     \
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     defined(_LIBUNWIND_TARGET_LOONGARCH) ||                                   \
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     defined(_LIBUNWIND_TARGET_RISCV) || defined(_LIBUNWIND_TARGET_S390X))
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#include <errno.h>
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#include <signal.h>
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#include <sys/syscall.h>
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#include <unistd.h>
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#define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
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#endif
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#if defined(_LIBUNWIND_TARGET_HAIKU) && defined(_LIBUNWIND_TARGET_X86_64)
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#include <OS.h>
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#include <signal.h>
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#define _LIBUNWIND_CHECK_HAIKU_SIGRETURN 1
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#endif
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#include "AddressSpace.hpp"
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#include "CompactUnwinder.hpp"
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#include "config.h"
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#include "DwarfInstructions.hpp"
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#include "EHHeaderParser.hpp"
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#include "libunwind.h"
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#include "libunwind_ext.h"
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#include "Registers.hpp"
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#include "RWMutex.hpp"
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#include "Unwind-EHABI.h"
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#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
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// Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
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// earlier) SDKs.
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// MinGW-w64 has always provided this struct.
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  #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
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      !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
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struct _DISPATCHER_CONTEXT {
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  ULONG64 ControlPc;
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  ULONG64 ImageBase;
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  PRUNTIME_FUNCTION FunctionEntry;
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  ULONG64 EstablisherFrame;
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  ULONG64 TargetIp;
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  PCONTEXT ContextRecord;
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  PEXCEPTION_ROUTINE LanguageHandler;
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  PVOID HandlerData;
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  PUNWIND_HISTORY_TABLE HistoryTable;
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  ULONG ScopeIndex;
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  ULONG Fill0;
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};
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  #endif
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struct UNWIND_INFO {
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  uint8_t Version : 3;
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  uint8_t Flags : 5;
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  uint8_t SizeOfProlog;
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  uint8_t CountOfCodes;
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  uint8_t FrameRegister : 4;
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  uint8_t FrameOffset : 4;
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  uint16_t UnwindCodes[2];
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};
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#pragma clang diagnostic push
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#pragma clang diagnostic ignored "-Wgnu-anonymous-struct"
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union UNWIND_INFO_ARM {
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  DWORD HeaderData;
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  struct {
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    DWORD FunctionLength : 18;
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    DWORD Version : 2;
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    DWORD ExceptionDataPresent : 1;
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    DWORD EpilogInHeader : 1;
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    DWORD FunctionFragment : 1;
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    DWORD EpilogCount : 5;
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    DWORD CodeWords : 4;
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  };
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};
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#pragma clang diagnostic pop
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extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
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    int, _Unwind_Action, uint64_t, _Unwind_Exception *,
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    struct _Unwind_Context *);
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#endif
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namespace libunwind {
115

116
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
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/// Cache of recently found FDEs.
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template <typename A>
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class _LIBUNWIND_HIDDEN DwarfFDECache {
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  typedef typename A::pint_t pint_t;
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public:
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  static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
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  static pint_t findFDE(pint_t mh, pint_t pc);
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  static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
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  static void removeAllIn(pint_t mh);
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  static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
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                                               unw_word_t ip_end,
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                                               unw_word_t fde, unw_word_t mh));
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private:
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  struct entry {
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    pint_t mh;
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    pint_t ip_start;
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    pint_t ip_end;
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    pint_t fde;
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  };
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  // These fields are all static to avoid needing an initializer.
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  // There is only one instance of this class per process.
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  static RWMutex _lock;
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#ifdef __APPLE__
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  static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
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  static bool _registeredForDyldUnloads;
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#endif
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  static entry *_buffer;
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  static entry *_bufferUsed;
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  static entry *_bufferEnd;
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  static entry _initialBuffer[64];
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};
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template <typename A>
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typename DwarfFDECache<A>::entry *
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DwarfFDECache<A>::_buffer = _initialBuffer;
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template <typename A>
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typename DwarfFDECache<A>::entry *
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DwarfFDECache<A>::_bufferUsed = _initialBuffer;
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template <typename A>
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typename DwarfFDECache<A>::entry *
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DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
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template <typename A>
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typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
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template <typename A>
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RWMutex DwarfFDECache<A>::_lock;
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#ifdef __APPLE__
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template <typename A>
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bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
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#endif
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template <typename A>
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typename DwarfFDECache<A>::pint_t DwarfFDECache<A>::findFDE(pint_t mh,
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                                                            pint_t pc) {
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  pint_t result = 0;
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  _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
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  for (entry *p = _buffer; p < _bufferUsed; ++p) {
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    if ((mh == p->mh) || (mh == kSearchAll)) {
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      if ((p->ip_start <= pc) && (pc < p->ip_end)) {
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        result = p->fde;
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        break;
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      }
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    }
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  }
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  _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
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  return result;
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}
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template <typename A>
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void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
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                           pint_t fde) {
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#if !defined(_LIBUNWIND_NO_HEAP)
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  _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
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  if (_bufferUsed >= _bufferEnd) {
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    size_t oldSize = (size_t)(_bufferEnd - _buffer);
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    size_t newSize = oldSize * 4;
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    // Can't use operator new (we are below it).
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    entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
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    memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
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    if (_buffer != _initialBuffer)
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      free(_buffer);
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    _buffer = newBuffer;
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    _bufferUsed = &newBuffer[oldSize];
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    _bufferEnd = &newBuffer[newSize];
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  }
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  _bufferUsed->mh = mh;
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  _bufferUsed->ip_start = ip_start;
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  _bufferUsed->ip_end = ip_end;
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  _bufferUsed->fde = fde;
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  ++_bufferUsed;
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#ifdef __APPLE__
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  if (!_registeredForDyldUnloads) {
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    _dyld_register_func_for_remove_image(&dyldUnloadHook);
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    _registeredForDyldUnloads = true;
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  }
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#endif
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  _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
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#endif
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}
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template <typename A>
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void DwarfFDECache<A>::removeAllIn(pint_t mh) {
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  _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
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  entry *d = _buffer;
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  for (const entry *s = _buffer; s < _bufferUsed; ++s) {
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    if (s->mh != mh) {
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      if (d != s)
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        *d = *s;
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      ++d;
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    }
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  }
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  _bufferUsed = d;
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  _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
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}
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#ifdef __APPLE__
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template <typename A>
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void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
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  removeAllIn((pint_t) mh);
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}
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#endif
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template <typename A>
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void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
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    unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
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  _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
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  for (entry *p = _buffer; p < _bufferUsed; ++p) {
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    (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
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  }
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  _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
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}
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#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
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#define arrayoffsetof(type, index, field)                                      \
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  (sizeof(type) * (index) + offsetof(type, field))
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260
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
261
template <typename A> class UnwindSectionHeader {
262
public:
263
  UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
264
      : _addressSpace(addressSpace), _addr(addr) {}
265

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  uint32_t version() const {
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    return _addressSpace.get32(_addr +
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                               offsetof(unwind_info_section_header, version));
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  }
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  uint32_t commonEncodingsArraySectionOffset() const {
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    return _addressSpace.get32(_addr +
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                               offsetof(unwind_info_section_header,
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                                        commonEncodingsArraySectionOffset));
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  }
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  uint32_t commonEncodingsArrayCount() const {
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    return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
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                                                commonEncodingsArrayCount));
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  }
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  uint32_t personalityArraySectionOffset() const {
280
    return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
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                                                personalityArraySectionOffset));
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  }
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  uint32_t personalityArrayCount() const {
284
    return _addressSpace.get32(
285
        _addr + offsetof(unwind_info_section_header, personalityArrayCount));
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  }
287
  uint32_t indexSectionOffset() const {
288
    return _addressSpace.get32(
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        _addr + offsetof(unwind_info_section_header, indexSectionOffset));
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  }
291
  uint32_t indexCount() const {
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    return _addressSpace.get32(
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        _addr + offsetof(unwind_info_section_header, indexCount));
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  }
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296
private:
297
  A                     &_addressSpace;
298
  typename A::pint_t     _addr;
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};
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template <typename A> class UnwindSectionIndexArray {
302
public:
303
  UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
304
      : _addressSpace(addressSpace), _addr(addr) {}
305

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  uint32_t functionOffset(uint32_t index) const {
307
    return _addressSpace.get32(
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        _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
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                              functionOffset));
310
  }
311
  uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
312
    return _addressSpace.get32(
313
        _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
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                              secondLevelPagesSectionOffset));
315
  }
316
  uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
317
    return _addressSpace.get32(
318
        _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
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                              lsdaIndexArraySectionOffset));
320
  }
321

322
private:
323
  A                   &_addressSpace;
324
  typename A::pint_t   _addr;
325
};
326

327
template <typename A> class UnwindSectionRegularPageHeader {
328
public:
329
  UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
330
      : _addressSpace(addressSpace), _addr(addr) {}
331

332
  uint32_t kind() const {
333
    return _addressSpace.get32(
334
        _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
335
  }
336
  uint16_t entryPageOffset() const {
337
    return _addressSpace.get16(
338
        _addr + offsetof(unwind_info_regular_second_level_page_header,
339
                         entryPageOffset));
340
  }
341
  uint16_t entryCount() const {
342
    return _addressSpace.get16(
343
        _addr +
344
        offsetof(unwind_info_regular_second_level_page_header, entryCount));
345
  }
346

347
private:
348
  A &_addressSpace;
349
  typename A::pint_t _addr;
350
};
351

352
template <typename A> class UnwindSectionRegularArray {
353
public:
354
  UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
355
      : _addressSpace(addressSpace), _addr(addr) {}
356

357
  uint32_t functionOffset(uint32_t index) const {
358
    return _addressSpace.get32(
359
        _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
360
                              functionOffset));
361
  }
362
  uint32_t encoding(uint32_t index) const {
363
    return _addressSpace.get32(
364
        _addr +
365
        arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
366
  }
367

368
private:
369
  A &_addressSpace;
370
  typename A::pint_t _addr;
371
};
372

373
template <typename A> class UnwindSectionCompressedPageHeader {
374
public:
375
  UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
376
      : _addressSpace(addressSpace), _addr(addr) {}
377

378
  uint32_t kind() const {
379
    return _addressSpace.get32(
380
        _addr +
381
        offsetof(unwind_info_compressed_second_level_page_header, kind));
382
  }
383
  uint16_t entryPageOffset() const {
384
    return _addressSpace.get16(
385
        _addr + offsetof(unwind_info_compressed_second_level_page_header,
386
                         entryPageOffset));
387
  }
388
  uint16_t entryCount() const {
389
    return _addressSpace.get16(
390
        _addr +
391
        offsetof(unwind_info_compressed_second_level_page_header, entryCount));
392
  }
393
  uint16_t encodingsPageOffset() const {
394
    return _addressSpace.get16(
395
        _addr + offsetof(unwind_info_compressed_second_level_page_header,
396
                         encodingsPageOffset));
397
  }
398
  uint16_t encodingsCount() const {
399
    return _addressSpace.get16(
400
        _addr + offsetof(unwind_info_compressed_second_level_page_header,
401
                         encodingsCount));
402
  }
403

404
private:
405
  A &_addressSpace;
406
  typename A::pint_t _addr;
407
};
408

409
template <typename A> class UnwindSectionCompressedArray {
410
public:
411
  UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
412
      : _addressSpace(addressSpace), _addr(addr) {}
413

414
  uint32_t functionOffset(uint32_t index) const {
415
    return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
416
        _addressSpace.get32(_addr + index * sizeof(uint32_t)));
417
  }
418
  uint16_t encodingIndex(uint32_t index) const {
419
    return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
420
        _addressSpace.get32(_addr + index * sizeof(uint32_t)));
421
  }
422

423
private:
424
  A &_addressSpace;
425
  typename A::pint_t _addr;
426
};
427

428
template <typename A> class UnwindSectionLsdaArray {
429
public:
430
  UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
431
      : _addressSpace(addressSpace), _addr(addr) {}
432

433
  uint32_t functionOffset(uint32_t index) const {
434
    return _addressSpace.get32(
435
        _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
436
                              index, functionOffset));
437
  }
438
  uint32_t lsdaOffset(uint32_t index) const {
439
    return _addressSpace.get32(
440
        _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
441
                              index, lsdaOffset));
442
  }
443

444
private:
445
  A                   &_addressSpace;
446
  typename A::pint_t   _addr;
447
};
448
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
449

450
class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
451
public:
452
  // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
453
  // This avoids an unnecessary dependency to libc++abi.
454
  void operator delete(void *, size_t) {}
455

456
  virtual ~AbstractUnwindCursor() {}
457
  virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
458
  virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
459
  virtual void setReg(int, unw_word_t) {
460
    _LIBUNWIND_ABORT("setReg not implemented");
461
  }
462
  virtual bool validFloatReg(int) {
463
    _LIBUNWIND_ABORT("validFloatReg not implemented");
464
  }
465
  virtual unw_fpreg_t getFloatReg(int) {
466
    _LIBUNWIND_ABORT("getFloatReg not implemented");
467
  }
468
  virtual void setFloatReg(int, unw_fpreg_t) {
469
    _LIBUNWIND_ABORT("setFloatReg not implemented");
470
  }
471
  virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); }
472
  virtual void getInfo(unw_proc_info_t *) {
473
    _LIBUNWIND_ABORT("getInfo not implemented");
474
  }
475
  virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
476
  virtual bool isSignalFrame() {
477
    _LIBUNWIND_ABORT("isSignalFrame not implemented");
478
  }
479
  virtual bool getFunctionName(char *, size_t, unw_word_t *) {
480
    _LIBUNWIND_ABORT("getFunctionName not implemented");
481
  }
482
  virtual void setInfoBasedOnIPRegister(bool = false) {
483
    _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
484
  }
485
  virtual const char *getRegisterName(int) {
486
    _LIBUNWIND_ABORT("getRegisterName not implemented");
487
  }
488
#ifdef __arm__
489
  virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
490
#endif
491

492
#ifdef _AIX
493
  virtual uintptr_t getDataRelBase() {
494
    _LIBUNWIND_ABORT("getDataRelBase not implemented");
495
  }
496
#endif
497

498
#if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
499
  virtual void *get_registers() {
500
    _LIBUNWIND_ABORT("get_registers not implemented");
501
  }
502
#endif
503
};
504

505
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
506

507
/// \c UnwindCursor contains all state (including all register values) during
508
/// an unwind.  This is normally stack-allocated inside a unw_cursor_t.
509
template <typename A, typename R>
510
class UnwindCursor : public AbstractUnwindCursor {
511
  typedef typename A::pint_t pint_t;
512
public:
513
                      UnwindCursor(unw_context_t *context, A &as);
514
                      UnwindCursor(CONTEXT *context, A &as);
515
                      UnwindCursor(A &as, void *threadArg);
516
  virtual             ~UnwindCursor() {}
517
  virtual bool        validReg(int);
518
  virtual unw_word_t  getReg(int);
519
  virtual void        setReg(int, unw_word_t);
520
  virtual bool        validFloatReg(int);
521
  virtual unw_fpreg_t getFloatReg(int);
522
  virtual void        setFloatReg(int, unw_fpreg_t);
523
  virtual int         step(bool = false);
524
  virtual void        getInfo(unw_proc_info_t *);
525
  virtual void        jumpto();
526
  virtual bool        isSignalFrame();
527
  virtual bool        getFunctionName(char *buf, size_t len, unw_word_t *off);
528
  virtual void        setInfoBasedOnIPRegister(bool isReturnAddress = false);
529
  virtual const char *getRegisterName(int num);
530
#ifdef __arm__
531
  virtual void        saveVFPAsX();
532
#endif
533

534
  DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
535
  void setDispatcherContext(DISPATCHER_CONTEXT *disp) {
536
    _dispContext = *disp;
537
    _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
538
    if (_dispContext.LanguageHandler) {
539
      _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
540
    } else
541
      _info.handler = 0;
542
  }
543

544
  // libunwind does not and should not depend on C++ library which means that we
545
  // need our own definition of inline placement new.
546
  static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
547

548
private:
549

550
  pint_t getLastPC() const { return _dispContext.ControlPc; }
551
  void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
552
  RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
553
#ifdef __arm__
554
    // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit.
555
    pc &= ~1U;
556
#endif
557
    // If pc points exactly at the end of the range, we might resolve the
558
    // next function instead. Decrement pc by 1 to fit inside the current
559
    // function.
560
    pc -= 1;
561
    _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
562
                                                        &_dispContext.ImageBase,
563
                                                        _dispContext.HistoryTable);
564
    *base = _dispContext.ImageBase;
565
    return _dispContext.FunctionEntry;
566
  }
567
  bool getInfoFromSEH(pint_t pc);
568
  int stepWithSEHData() {
569
    _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
570
                                                    _dispContext.ImageBase,
571
                                                    _dispContext.ControlPc,
572
                                                    _dispContext.FunctionEntry,
573
                                                    _dispContext.ContextRecord,
574
                                                    &_dispContext.HandlerData,
575
                                                    &_dispContext.EstablisherFrame,
576
                                                    NULL);
577
    // Update some fields of the unwind info now, since we have them.
578
    _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
579
    if (_dispContext.LanguageHandler) {
580
      _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
581
    } else
582
      _info.handler = 0;
583
    return UNW_STEP_SUCCESS;
584
  }
585

586
  A                   &_addressSpace;
587
  unw_proc_info_t      _info;
588
  DISPATCHER_CONTEXT   _dispContext;
589
  CONTEXT              _msContext;
590
  UNWIND_HISTORY_TABLE _histTable;
591
  bool                 _unwindInfoMissing;
592
};
593

594

595
template <typename A, typename R>
596
UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
597
    : _addressSpace(as), _unwindInfoMissing(false) {
598
  static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
599
                "UnwindCursor<> does not fit in unw_cursor_t");
600
  static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
601
                "UnwindCursor<> requires more alignment than unw_cursor_t");
602
  memset(&_info, 0, sizeof(_info));
603
  memset(&_histTable, 0, sizeof(_histTable));
604
  memset(&_dispContext, 0, sizeof(_dispContext));
605
  _dispContext.ContextRecord = &_msContext;
606
  _dispContext.HistoryTable = &_histTable;
607
  // Initialize MS context from ours.
608
  R r(context);
609
  RtlCaptureContext(&_msContext);
610
  _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
611
#if defined(_LIBUNWIND_TARGET_X86_64)
612
  _msContext.Rax = r.getRegister(UNW_X86_64_RAX);
613
  _msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
614
  _msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
615
  _msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
616
  _msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
617
  _msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
618
  _msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
619
  _msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
620
  _msContext.R8 = r.getRegister(UNW_X86_64_R8);
621
  _msContext.R9 = r.getRegister(UNW_X86_64_R9);
622
  _msContext.R10 = r.getRegister(UNW_X86_64_R10);
623
  _msContext.R11 = r.getRegister(UNW_X86_64_R11);
624
  _msContext.R12 = r.getRegister(UNW_X86_64_R12);
625
  _msContext.R13 = r.getRegister(UNW_X86_64_R13);
626
  _msContext.R14 = r.getRegister(UNW_X86_64_R14);
627
  _msContext.R15 = r.getRegister(UNW_X86_64_R15);
628
  _msContext.Rip = r.getRegister(UNW_REG_IP);
629
  union {
630
    v128 v;
631
    M128A m;
632
  } t;
633
  t.v = r.getVectorRegister(UNW_X86_64_XMM0);
634
  _msContext.Xmm0 = t.m;
635
  t.v = r.getVectorRegister(UNW_X86_64_XMM1);
636
  _msContext.Xmm1 = t.m;
637
  t.v = r.getVectorRegister(UNW_X86_64_XMM2);
638
  _msContext.Xmm2 = t.m;
639
  t.v = r.getVectorRegister(UNW_X86_64_XMM3);
640
  _msContext.Xmm3 = t.m;
641
  t.v = r.getVectorRegister(UNW_X86_64_XMM4);
642
  _msContext.Xmm4 = t.m;
643
  t.v = r.getVectorRegister(UNW_X86_64_XMM5);
644
  _msContext.Xmm5 = t.m;
645
  t.v = r.getVectorRegister(UNW_X86_64_XMM6);
646
  _msContext.Xmm6 = t.m;
647
  t.v = r.getVectorRegister(UNW_X86_64_XMM7);
648
  _msContext.Xmm7 = t.m;
649
  t.v = r.getVectorRegister(UNW_X86_64_XMM8);
650
  _msContext.Xmm8 = t.m;
651
  t.v = r.getVectorRegister(UNW_X86_64_XMM9);
652
  _msContext.Xmm9 = t.m;
653
  t.v = r.getVectorRegister(UNW_X86_64_XMM10);
654
  _msContext.Xmm10 = t.m;
655
  t.v = r.getVectorRegister(UNW_X86_64_XMM11);
656
  _msContext.Xmm11 = t.m;
657
  t.v = r.getVectorRegister(UNW_X86_64_XMM12);
658
  _msContext.Xmm12 = t.m;
659
  t.v = r.getVectorRegister(UNW_X86_64_XMM13);
660
  _msContext.Xmm13 = t.m;
661
  t.v = r.getVectorRegister(UNW_X86_64_XMM14);
662
  _msContext.Xmm14 = t.m;
663
  t.v = r.getVectorRegister(UNW_X86_64_XMM15);
664
  _msContext.Xmm15 = t.m;
665
#elif defined(_LIBUNWIND_TARGET_ARM)
666
  _msContext.R0 = r.getRegister(UNW_ARM_R0);
667
  _msContext.R1 = r.getRegister(UNW_ARM_R1);
668
  _msContext.R2 = r.getRegister(UNW_ARM_R2);
669
  _msContext.R3 = r.getRegister(UNW_ARM_R3);
670
  _msContext.R4 = r.getRegister(UNW_ARM_R4);
671
  _msContext.R5 = r.getRegister(UNW_ARM_R5);
672
  _msContext.R6 = r.getRegister(UNW_ARM_R6);
673
  _msContext.R7 = r.getRegister(UNW_ARM_R7);
674
  _msContext.R8 = r.getRegister(UNW_ARM_R8);
675
  _msContext.R9 = r.getRegister(UNW_ARM_R9);
676
  _msContext.R10 = r.getRegister(UNW_ARM_R10);
677
  _msContext.R11 = r.getRegister(UNW_ARM_R11);
678
  _msContext.R12 = r.getRegister(UNW_ARM_R12);
679
  _msContext.Sp = r.getRegister(UNW_ARM_SP);
680
  _msContext.Lr = r.getRegister(UNW_ARM_LR);
681
  _msContext.Pc = r.getRegister(UNW_ARM_IP);
682
  for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
683
    union {
684
      uint64_t w;
685
      double d;
686
    } d;
687
    d.d = r.getFloatRegister(i);
688
    _msContext.D[i - UNW_ARM_D0] = d.w;
689
  }
690
#elif defined(_LIBUNWIND_TARGET_AARCH64)
691
  for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
692
    _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
693
  _msContext.Sp = r.getRegister(UNW_REG_SP);
694
  _msContext.Pc = r.getRegister(UNW_REG_IP);
695
  for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
696
    _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
697
#endif
698
}
699

700
template <typename A, typename R>
701
UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
702
    : _addressSpace(as), _unwindInfoMissing(false) {
703
  static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
704
                "UnwindCursor<> does not fit in unw_cursor_t");
705
  memset(&_info, 0, sizeof(_info));
706
  memset(&_histTable, 0, sizeof(_histTable));
707
  memset(&_dispContext, 0, sizeof(_dispContext));
708
  _dispContext.ContextRecord = &_msContext;
709
  _dispContext.HistoryTable = &_histTable;
710
  _msContext = *context;
711
}
712

713

714
template <typename A, typename R>
715
bool UnwindCursor<A, R>::validReg(int regNum) {
716
  if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
717
#if defined(_LIBUNWIND_TARGET_X86_64)
718
  if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_RIP) return true;
719
#elif defined(_LIBUNWIND_TARGET_ARM)
720
  if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
721
      regNum == UNW_ARM_RA_AUTH_CODE)
722
    return true;
723
#elif defined(_LIBUNWIND_TARGET_AARCH64)
724
  if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
725
#endif
726
  return false;
727
}
728

729
template <typename A, typename R>
730
unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
731
  switch (regNum) {
732
#if defined(_LIBUNWIND_TARGET_X86_64)
733
  case UNW_X86_64_RIP:
734
  case UNW_REG_IP: return _msContext.Rip;
735
  case UNW_X86_64_RAX: return _msContext.Rax;
736
  case UNW_X86_64_RDX: return _msContext.Rdx;
737
  case UNW_X86_64_RCX: return _msContext.Rcx;
738
  case UNW_X86_64_RBX: return _msContext.Rbx;
739
  case UNW_REG_SP:
740
  case UNW_X86_64_RSP: return _msContext.Rsp;
741
  case UNW_X86_64_RBP: return _msContext.Rbp;
742
  case UNW_X86_64_RSI: return _msContext.Rsi;
743
  case UNW_X86_64_RDI: return _msContext.Rdi;
744
  case UNW_X86_64_R8: return _msContext.R8;
745
  case UNW_X86_64_R9: return _msContext.R9;
746
  case UNW_X86_64_R10: return _msContext.R10;
747
  case UNW_X86_64_R11: return _msContext.R11;
748
  case UNW_X86_64_R12: return _msContext.R12;
749
  case UNW_X86_64_R13: return _msContext.R13;
750
  case UNW_X86_64_R14: return _msContext.R14;
751
  case UNW_X86_64_R15: return _msContext.R15;
752
#elif defined(_LIBUNWIND_TARGET_ARM)
753
  case UNW_ARM_R0: return _msContext.R0;
754
  case UNW_ARM_R1: return _msContext.R1;
755
  case UNW_ARM_R2: return _msContext.R2;
756
  case UNW_ARM_R3: return _msContext.R3;
757
  case UNW_ARM_R4: return _msContext.R4;
758
  case UNW_ARM_R5: return _msContext.R5;
759
  case UNW_ARM_R6: return _msContext.R6;
760
  case UNW_ARM_R7: return _msContext.R7;
761
  case UNW_ARM_R8: return _msContext.R8;
762
  case UNW_ARM_R9: return _msContext.R9;
763
  case UNW_ARM_R10: return _msContext.R10;
764
  case UNW_ARM_R11: return _msContext.R11;
765
  case UNW_ARM_R12: return _msContext.R12;
766
  case UNW_REG_SP:
767
  case UNW_ARM_SP: return _msContext.Sp;
768
  case UNW_ARM_LR: return _msContext.Lr;
769
  case UNW_REG_IP:
770
  case UNW_ARM_IP: return _msContext.Pc;
771
#elif defined(_LIBUNWIND_TARGET_AARCH64)
772
  case UNW_REG_SP: return _msContext.Sp;
773
  case UNW_REG_IP: return _msContext.Pc;
774
  default: return _msContext.X[regNum - UNW_AARCH64_X0];
775
#endif
776
  }
777
  _LIBUNWIND_ABORT("unsupported register");
778
}
779

780
template <typename A, typename R>
781
void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
782
  switch (regNum) {
783
#if defined(_LIBUNWIND_TARGET_X86_64)
784
  case UNW_X86_64_RIP:
785
  case UNW_REG_IP: _msContext.Rip = value; break;
786
  case UNW_X86_64_RAX: _msContext.Rax = value; break;
787
  case UNW_X86_64_RDX: _msContext.Rdx = value; break;
788
  case UNW_X86_64_RCX: _msContext.Rcx = value; break;
789
  case UNW_X86_64_RBX: _msContext.Rbx = value; break;
790
  case UNW_REG_SP:
791
  case UNW_X86_64_RSP: _msContext.Rsp = value; break;
792
  case UNW_X86_64_RBP: _msContext.Rbp = value; break;
793
  case UNW_X86_64_RSI: _msContext.Rsi = value; break;
794
  case UNW_X86_64_RDI: _msContext.Rdi = value; break;
795
  case UNW_X86_64_R8: _msContext.R8 = value; break;
796
  case UNW_X86_64_R9: _msContext.R9 = value; break;
797
  case UNW_X86_64_R10: _msContext.R10 = value; break;
798
  case UNW_X86_64_R11: _msContext.R11 = value; break;
799
  case UNW_X86_64_R12: _msContext.R12 = value; break;
800
  case UNW_X86_64_R13: _msContext.R13 = value; break;
801
  case UNW_X86_64_R14: _msContext.R14 = value; break;
802
  case UNW_X86_64_R15: _msContext.R15 = value; break;
803
#elif defined(_LIBUNWIND_TARGET_ARM)
804
  case UNW_ARM_R0: _msContext.R0 = value; break;
805
  case UNW_ARM_R1: _msContext.R1 = value; break;
806
  case UNW_ARM_R2: _msContext.R2 = value; break;
807
  case UNW_ARM_R3: _msContext.R3 = value; break;
808
  case UNW_ARM_R4: _msContext.R4 = value; break;
809
  case UNW_ARM_R5: _msContext.R5 = value; break;
810
  case UNW_ARM_R6: _msContext.R6 = value; break;
811
  case UNW_ARM_R7: _msContext.R7 = value; break;
812
  case UNW_ARM_R8: _msContext.R8 = value; break;
813
  case UNW_ARM_R9: _msContext.R9 = value; break;
814
  case UNW_ARM_R10: _msContext.R10 = value; break;
815
  case UNW_ARM_R11: _msContext.R11 = value; break;
816
  case UNW_ARM_R12: _msContext.R12 = value; break;
817
  case UNW_REG_SP:
818
  case UNW_ARM_SP: _msContext.Sp = value; break;
819
  case UNW_ARM_LR: _msContext.Lr = value; break;
820
  case UNW_REG_IP:
821
  case UNW_ARM_IP: _msContext.Pc = value; break;
822
#elif defined(_LIBUNWIND_TARGET_AARCH64)
823
  case UNW_REG_SP: _msContext.Sp = value; break;
824
  case UNW_REG_IP: _msContext.Pc = value; break;
825
  case UNW_AARCH64_X0:
826
  case UNW_AARCH64_X1:
827
  case UNW_AARCH64_X2:
828
  case UNW_AARCH64_X3:
829
  case UNW_AARCH64_X4:
830
  case UNW_AARCH64_X5:
831
  case UNW_AARCH64_X6:
832
  case UNW_AARCH64_X7:
833
  case UNW_AARCH64_X8:
834
  case UNW_AARCH64_X9:
835
  case UNW_AARCH64_X10:
836
  case UNW_AARCH64_X11:
837
  case UNW_AARCH64_X12:
838
  case UNW_AARCH64_X13:
839
  case UNW_AARCH64_X14:
840
  case UNW_AARCH64_X15:
841
  case UNW_AARCH64_X16:
842
  case UNW_AARCH64_X17:
843
  case UNW_AARCH64_X18:
844
  case UNW_AARCH64_X19:
845
  case UNW_AARCH64_X20:
846
  case UNW_AARCH64_X21:
847
  case UNW_AARCH64_X22:
848
  case UNW_AARCH64_X23:
849
  case UNW_AARCH64_X24:
850
  case UNW_AARCH64_X25:
851
  case UNW_AARCH64_X26:
852
  case UNW_AARCH64_X27:
853
  case UNW_AARCH64_X28:
854
  case UNW_AARCH64_FP:
855
  case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
856
#endif
857
  default:
858
    _LIBUNWIND_ABORT("unsupported register");
859
  }
860
}
861

862
template <typename A, typename R>
863
bool UnwindCursor<A, R>::validFloatReg(int regNum) {
864
#if defined(_LIBUNWIND_TARGET_ARM)
865
  if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
866
  if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
867
#elif defined(_LIBUNWIND_TARGET_AARCH64)
868
  if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
869
#else
870
  (void)regNum;
871
#endif
872
  return false;
873
}
874

875
template <typename A, typename R>
876
unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
877
#if defined(_LIBUNWIND_TARGET_ARM)
878
  if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
879
    union {
880
      uint32_t w;
881
      float f;
882
    } d;
883
    d.w = _msContext.S[regNum - UNW_ARM_S0];
884
    return d.f;
885
  }
886
  if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
887
    union {
888
      uint64_t w;
889
      double d;
890
    } d;
891
    d.w = _msContext.D[regNum - UNW_ARM_D0];
892
    return d.d;
893
  }
894
  _LIBUNWIND_ABORT("unsupported float register");
895
#elif defined(_LIBUNWIND_TARGET_AARCH64)
896
  return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
897
#else
898
  (void)regNum;
899
  _LIBUNWIND_ABORT("float registers unimplemented");
900
#endif
901
}
902

903
template <typename A, typename R>
904
void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
905
#if defined(_LIBUNWIND_TARGET_ARM)
906
  if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
907
    union {
908
      uint32_t w;
909
      float f;
910
    } d;
911
    d.f = (float)value;
912
    _msContext.S[regNum - UNW_ARM_S0] = d.w;
913
  }
914
  if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
915
    union {
916
      uint64_t w;
917
      double d;
918
    } d;
919
    d.d = value;
920
    _msContext.D[regNum - UNW_ARM_D0] = d.w;
921
  }
922
  _LIBUNWIND_ABORT("unsupported float register");
923
#elif defined(_LIBUNWIND_TARGET_AARCH64)
924
  _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
925
#else
926
  (void)regNum;
927
  (void)value;
928
  _LIBUNWIND_ABORT("float registers unimplemented");
929
#endif
930
}
931

932
template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
933
  RtlRestoreContext(&_msContext, nullptr);
934
}
935

936
#ifdef __arm__
937
template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
938
#endif
939

940
template <typename A, typename R>
941
const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
942
  return R::getRegisterName(regNum);
943
}
944

945
template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
946
  return false;
947
}
948

949
#else  // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
950

951
/// UnwindCursor contains all state (including all register values) during
952
/// an unwind.  This is normally stack allocated inside a unw_cursor_t.
953
template <typename A, typename R>
954
class UnwindCursor : public AbstractUnwindCursor{
955
  typedef typename A::pint_t pint_t;
956
public:
957
                      UnwindCursor(unw_context_t *context, A &as);
958
                      UnwindCursor(A &as, void *threadArg);
959
  virtual             ~UnwindCursor() {}
960
  virtual bool        validReg(int);
961
  virtual unw_word_t  getReg(int);
962
  virtual void        setReg(int, unw_word_t);
963
  virtual bool        validFloatReg(int);
964
  virtual unw_fpreg_t getFloatReg(int);
965
  virtual void        setFloatReg(int, unw_fpreg_t);
966
  virtual int         step(bool stage2 = false);
967
  virtual void        getInfo(unw_proc_info_t *);
968
  virtual void        jumpto();
969
  virtual bool        isSignalFrame();
970
  virtual bool        getFunctionName(char *buf, size_t len, unw_word_t *off);
971
  virtual void        setInfoBasedOnIPRegister(bool isReturnAddress = false);
972
  virtual const char *getRegisterName(int num);
973
#ifdef __arm__
974
  virtual void        saveVFPAsX();
975
#endif
976

977
#ifdef _AIX
978
  virtual uintptr_t getDataRelBase();
979
#endif
980

981
#if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
982
  virtual void *get_registers() { return &_registers; }
983
#endif
984

985
  // libunwind does not and should not depend on C++ library which means that we
986
  // need our own definition of inline placement new.
987
  static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
988

989
private:
990

991
#if defined(_LIBUNWIND_ARM_EHABI)
992
  bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections &sects);
993

994
  int stepWithEHABI() {
995
    size_t len = 0;
996
    size_t off = 0;
997
    // FIXME: Calling decode_eht_entry() here is violating the libunwind
998
    // abstraction layer.
999
    const uint32_t *ehtp =
1000
        decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
1001
                         &off, &len);
1002
    if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
1003
            _URC_CONTINUE_UNWIND)
1004
      return UNW_STEP_END;
1005
    return UNW_STEP_SUCCESS;
1006
  }
1007
#endif
1008

1009
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
1010
  bool setInfoForSigReturn() {
1011
    R dummy;
1012
    return setInfoForSigReturn(dummy);
1013
  }
1014
  int stepThroughSigReturn() {
1015
    R dummy;
1016
    return stepThroughSigReturn(dummy);
1017
  }
1018
  bool isReadableAddr(const pint_t addr) const;
1019
#if defined(_LIBUNWIND_TARGET_AARCH64)
1020
  bool setInfoForSigReturn(Registers_arm64 &);
1021
  int stepThroughSigReturn(Registers_arm64 &);
1022
#endif
1023
#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1024
  bool setInfoForSigReturn(Registers_loongarch &);
1025
  int stepThroughSigReturn(Registers_loongarch &);
1026
#endif
1027
#if defined(_LIBUNWIND_TARGET_RISCV)
1028
  bool setInfoForSigReturn(Registers_riscv &);
1029
  int stepThroughSigReturn(Registers_riscv &);
1030
#endif
1031
#if defined(_LIBUNWIND_TARGET_S390X)
1032
  bool setInfoForSigReturn(Registers_s390x &);
1033
  int stepThroughSigReturn(Registers_s390x &);
1034
#endif
1035
  template <typename Registers> bool setInfoForSigReturn(Registers &) {
1036
    return false;
1037
  }
1038
  template <typename Registers> int stepThroughSigReturn(Registers &) {
1039
    return UNW_STEP_END;
1040
  }
1041
#elif defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
1042
  bool setInfoForSigReturn();
1043
  int stepThroughSigReturn();
1044
#endif
1045

1046
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1047
  bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1048
                         const typename CFI_Parser<A>::CIE_Info &cieInfo,
1049
                         pint_t pc, uintptr_t dso_base);
1050
  bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections &sects,
1051
                                            uint32_t fdeSectionOffsetHint=0);
1052
  int stepWithDwarfFDE(bool stage2) {
1053
    return DwarfInstructions<A, R>::stepWithDwarf(
1054
        _addressSpace, (pint_t)this->getReg(UNW_REG_IP),
1055
        (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2);
1056
  }
1057
#endif
1058

1059
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1060
  bool getInfoFromCompactEncodingSection(pint_t pc,
1061
                                            const UnwindInfoSections &sects);
1062
  int stepWithCompactEncoding(bool stage2 = false) {
1063
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1064
    if ( compactSaysUseDwarf() )
1065
      return stepWithDwarfFDE(stage2);
1066
#endif
1067
    R dummy;
1068
    return stepWithCompactEncoding(dummy);
1069
  }
1070

1071
#if defined(_LIBUNWIND_TARGET_X86_64)
1072
  int stepWithCompactEncoding(Registers_x86_64 &) {
1073
    return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
1074
        _info.format, _info.start_ip, _addressSpace, _registers);
1075
  }
1076
#endif
1077

1078
#if defined(_LIBUNWIND_TARGET_I386)
1079
  int stepWithCompactEncoding(Registers_x86 &) {
1080
    return CompactUnwinder_x86<A>::stepWithCompactEncoding(
1081
        _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
1082
  }
1083
#endif
1084

1085
#if defined(_LIBUNWIND_TARGET_PPC)
1086
  int stepWithCompactEncoding(Registers_ppc &) {
1087
    return UNW_EINVAL;
1088
  }
1089
#endif
1090

1091
#if defined(_LIBUNWIND_TARGET_PPC64)
1092
  int stepWithCompactEncoding(Registers_ppc64 &) {
1093
    return UNW_EINVAL;
1094
  }
1095
#endif
1096

1097

1098
#if defined(_LIBUNWIND_TARGET_AARCH64)
1099
  int stepWithCompactEncoding(Registers_arm64 &) {
1100
    return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
1101
        _info.format, _info.start_ip, _addressSpace, _registers);
1102
  }
1103
#endif
1104

1105
#if defined(_LIBUNWIND_TARGET_MIPS_O32)
1106
  int stepWithCompactEncoding(Registers_mips_o32 &) {
1107
    return UNW_EINVAL;
1108
  }
1109
#endif
1110

1111
#if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
1112
  int stepWithCompactEncoding(Registers_mips_newabi &) {
1113
    return UNW_EINVAL;
1114
  }
1115
#endif
1116

1117
#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1118
  int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; }
1119
#endif
1120

1121
#if defined(_LIBUNWIND_TARGET_SPARC)
1122
  int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
1123
#endif
1124

1125
#if defined(_LIBUNWIND_TARGET_SPARC64)
1126
  int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
1127
#endif
1128

1129
#if defined (_LIBUNWIND_TARGET_RISCV)
1130
  int stepWithCompactEncoding(Registers_riscv &) {
1131
    return UNW_EINVAL;
1132
  }
1133
#endif
1134

1135
  bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
1136
    R dummy;
1137
    return compactSaysUseDwarf(dummy, offset);
1138
  }
1139

1140
#if defined(_LIBUNWIND_TARGET_X86_64)
1141
  bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
1142
    if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
1143
      if (offset)
1144
        *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
1145
      return true;
1146
    }
1147
    return false;
1148
  }
1149
#endif
1150

1151
#if defined(_LIBUNWIND_TARGET_I386)
1152
  bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
1153
    if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
1154
      if (offset)
1155
        *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
1156
      return true;
1157
    }
1158
    return false;
1159
  }
1160
#endif
1161

1162
#if defined(_LIBUNWIND_TARGET_PPC)
1163
  bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
1164
    return true;
1165
  }
1166
#endif
1167

1168
#if defined(_LIBUNWIND_TARGET_PPC64)
1169
  bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
1170
    return true;
1171
  }
1172
#endif
1173

1174
#if defined(_LIBUNWIND_TARGET_AARCH64)
1175
  bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
1176
    if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
1177
      if (offset)
1178
        *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
1179
      return true;
1180
    }
1181
    return false;
1182
  }
1183
#endif
1184

1185
#if defined(_LIBUNWIND_TARGET_MIPS_O32)
1186
  bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
1187
    return true;
1188
  }
1189
#endif
1190

1191
#if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
1192
  bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
1193
    return true;
1194
  }
1195
#endif
1196

1197
#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1198
  bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const {
1199
    return true;
1200
  }
1201
#endif
1202

1203
#if defined(_LIBUNWIND_TARGET_SPARC)
1204
  bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
1205
#endif
1206

1207
#if defined(_LIBUNWIND_TARGET_SPARC64)
1208
  bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
1209
    return true;
1210
  }
1211
#endif
1212

1213
#if defined (_LIBUNWIND_TARGET_RISCV)
1214
  bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
1215
    return true;
1216
  }
1217
#endif
1218

1219
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1220

1221
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1222
  compact_unwind_encoding_t dwarfEncoding() const {
1223
    R dummy;
1224
    return dwarfEncoding(dummy);
1225
  }
1226

1227
#if defined(_LIBUNWIND_TARGET_X86_64)
1228
  compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
1229
    return UNWIND_X86_64_MODE_DWARF;
1230
  }
1231
#endif
1232

1233
#if defined(_LIBUNWIND_TARGET_I386)
1234
  compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
1235
    return UNWIND_X86_MODE_DWARF;
1236
  }
1237
#endif
1238

1239
#if defined(_LIBUNWIND_TARGET_PPC)
1240
  compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
1241
    return 0;
1242
  }
1243
#endif
1244

1245
#if defined(_LIBUNWIND_TARGET_PPC64)
1246
  compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
1247
    return 0;
1248
  }
1249
#endif
1250

1251
#if defined(_LIBUNWIND_TARGET_AARCH64)
1252
  compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
1253
    return UNWIND_ARM64_MODE_DWARF;
1254
  }
1255
#endif
1256

1257
#if defined(_LIBUNWIND_TARGET_ARM)
1258
  compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
1259
    return 0;
1260
  }
1261
#endif
1262

1263
#if defined (_LIBUNWIND_TARGET_OR1K)
1264
  compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
1265
    return 0;
1266
  }
1267
#endif
1268

1269
#if defined (_LIBUNWIND_TARGET_HEXAGON)
1270
  compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
1271
    return 0;
1272
  }
1273
#endif
1274

1275
#if defined (_LIBUNWIND_TARGET_MIPS_O32)
1276
  compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
1277
    return 0;
1278
  }
1279
#endif
1280

1281
#if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
1282
  compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
1283
    return 0;
1284
  }
1285
#endif
1286

1287
#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1288
  compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const {
1289
    return 0;
1290
  }
1291
#endif
1292

1293
#if defined(_LIBUNWIND_TARGET_SPARC)
1294
  compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
1295
#endif
1296

1297
#if defined(_LIBUNWIND_TARGET_SPARC64)
1298
  compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
1299
    return 0;
1300
  }
1301
#endif
1302

1303
#if defined (_LIBUNWIND_TARGET_RISCV)
1304
  compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
1305
    return 0;
1306
  }
1307
#endif
1308

1309
#if defined (_LIBUNWIND_TARGET_S390X)
1310
  compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const {
1311
    return 0;
1312
  }
1313
#endif
1314

1315
#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1316

1317
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1318
  // For runtime environments using SEH unwind data without Windows runtime
1319
  // support.
1320
  pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
1321
  void setLastPC(pint_t pc) { /* FIXME: Implement */ }
1322
  RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
1323
    /* FIXME: Implement */
1324
    *base = 0;
1325
    return nullptr;
1326
  }
1327
  bool getInfoFromSEH(pint_t pc);
1328
  int stepWithSEHData() { /* FIXME: Implement */ return 0; }
1329
#endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1330

1331
#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1332
  bool getInfoFromTBTable(pint_t pc, R &registers);
1333
  int stepWithTBTable(pint_t pc, tbtable *TBTable, R &registers,
1334
                      bool &isSignalFrame);
1335
  int stepWithTBTableData() {
1336
    return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
1337
                           reinterpret_cast<tbtable *>(_info.unwind_info),
1338
                           _registers, _isSignalFrame);
1339
  }
1340
#endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1341

1342
  A               &_addressSpace;
1343
  R                _registers;
1344
  unw_proc_info_t  _info;
1345
  bool             _unwindInfoMissing;
1346
  bool             _isSignalFrame;
1347
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) ||                               \
1348
    defined(_LIBUNWIND_TARGET_HAIKU)
1349
  bool             _isSigReturn = false;
1350
#endif
1351
};
1352

1353

1354
template <typename A, typename R>
1355
UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
1356
    : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
1357
      _isSignalFrame(false) {
1358
  static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
1359
                "UnwindCursor<> does not fit in unw_cursor_t");
1360
  static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
1361
                "UnwindCursor<> requires more alignment than unw_cursor_t");
1362
  memset(&_info, 0, sizeof(_info));
1363
}
1364

1365
template <typename A, typename R>
1366
UnwindCursor<A, R>::UnwindCursor(A &as, void *)
1367
    : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
1368
  memset(&_info, 0, sizeof(_info));
1369
  // FIXME
1370
  // fill in _registers from thread arg
1371
}
1372

1373

1374
template <typename A, typename R>
1375
bool UnwindCursor<A, R>::validReg(int regNum) {
1376
  return _registers.validRegister(regNum);
1377
}
1378

1379
template <typename A, typename R>
1380
unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
1381
  return _registers.getRegister(regNum);
1382
}
1383

1384
template <typename A, typename R>
1385
void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
1386
  _registers.setRegister(regNum, (typename A::pint_t)value);
1387
}
1388

1389
template <typename A, typename R>
1390
bool UnwindCursor<A, R>::validFloatReg(int regNum) {
1391
  return _registers.validFloatRegister(regNum);
1392
}
1393

1394
template <typename A, typename R>
1395
unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
1396
  return _registers.getFloatRegister(regNum);
1397
}
1398

1399
template <typename A, typename R>
1400
void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
1401
  _registers.setFloatRegister(regNum, value);
1402
}
1403

1404
template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
1405
  _registers.jumpto();
1406
}
1407

1408
#ifdef __arm__
1409
template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
1410
  _registers.saveVFPAsX();
1411
}
1412
#endif
1413

1414
#ifdef _AIX
1415
template <typename A, typename R>
1416
uintptr_t UnwindCursor<A, R>::getDataRelBase() {
1417
  return reinterpret_cast<uintptr_t>(_info.extra);
1418
}
1419
#endif
1420

1421
template <typename A, typename R>
1422
const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
1423
  return _registers.getRegisterName(regNum);
1424
}
1425

1426
template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
1427
  return _isSignalFrame;
1428
}
1429

1430
#endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1431

1432
#if defined(_LIBUNWIND_ARM_EHABI)
1433
template<typename A>
1434
struct EHABISectionIterator {
1435
  typedef EHABISectionIterator _Self;
1436

1437
  typedef typename A::pint_t value_type;
1438
  typedef typename A::pint_t* pointer;
1439
  typedef typename A::pint_t& reference;
1440
  typedef size_t size_type;
1441
  typedef size_t difference_type;
1442

1443
  static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
1444
    return _Self(addressSpace, sects, 0);
1445
  }
1446
  static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
1447
    return _Self(addressSpace, sects,
1448
                 sects.arm_section_length / sizeof(EHABIIndexEntry));
1449
  }
1450

1451
  EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
1452
      : _i(i), _addressSpace(&addressSpace), _sects(&sects) {}
1453

1454
  _Self& operator++() { ++_i; return *this; }
1455
  _Self& operator+=(size_t a) { _i += a; return *this; }
1456
  _Self& operator--() { assert(_i > 0); --_i; return *this; }
1457
  _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
1458

1459
  _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
1460
  _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
1461

1462
  size_t operator-(const _Self& other) const { return _i - other._i; }
1463

1464
  bool operator==(const _Self& other) const {
1465
    assert(_addressSpace == other._addressSpace);
1466
    assert(_sects == other._sects);
1467
    return _i == other._i;
1468
  }
1469

1470
  bool operator!=(const _Self& other) const {
1471
    assert(_addressSpace == other._addressSpace);
1472
    assert(_sects == other._sects);
1473
    return _i != other._i;
1474
  }
1475

1476
  typename A::pint_t operator*() const { return functionAddress(); }
1477

1478
  typename A::pint_t functionAddress() const {
1479
    typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1480
        EHABIIndexEntry, _i, functionOffset);
1481
    return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
1482
  }
1483

1484
  typename A::pint_t dataAddress() {
1485
    typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1486
        EHABIIndexEntry, _i, data);
1487
    return indexAddr;
1488
  }
1489

1490
 private:
1491
  size_t _i;
1492
  A* _addressSpace;
1493
  const UnwindInfoSections* _sects;
1494
};
1495

1496
namespace {
1497

1498
template <typename A>
1499
EHABISectionIterator<A> EHABISectionUpperBound(
1500
    EHABISectionIterator<A> first,
1501
    EHABISectionIterator<A> last,
1502
    typename A::pint_t value) {
1503
  size_t len = last - first;
1504
  while (len > 0) {
1505
    size_t l2 = len / 2;
1506
    EHABISectionIterator<A> m = first + l2;
1507
    if (value < *m) {
1508
        len = l2;
1509
    } else {
1510
        first = ++m;
1511
        len -= l2 + 1;
1512
    }
1513
  }
1514
  return first;
1515
}
1516

1517
}
1518

1519
template <typename A, typename R>
1520
bool UnwindCursor<A, R>::getInfoFromEHABISection(
1521
    pint_t pc,
1522
    const UnwindInfoSections &sects) {
1523
  EHABISectionIterator<A> begin =
1524
      EHABISectionIterator<A>::begin(_addressSpace, sects);
1525
  EHABISectionIterator<A> end =
1526
      EHABISectionIterator<A>::end(_addressSpace, sects);
1527
  if (begin == end)
1528
    return false;
1529

1530
  EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
1531
  if (itNextPC == begin)
1532
    return false;
1533
  EHABISectionIterator<A> itThisPC = itNextPC - 1;
1534

1535
  pint_t thisPC = itThisPC.functionAddress();
1536
  // If an exception is thrown from a function, corresponding to the last entry
1537
  // in the table, we don't really know the function extent and have to choose a
1538
  // value for nextPC. Choosing max() will allow the range check during trace to
1539
  // succeed.
1540
  pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
1541
  pint_t indexDataAddr = itThisPC.dataAddress();
1542

1543
  if (indexDataAddr == 0)
1544
    return false;
1545

1546
  uint32_t indexData = _addressSpace.get32(indexDataAddr);
1547
  if (indexData == UNW_EXIDX_CANTUNWIND)
1548
    return false;
1549

1550
  // If the high bit is set, the exception handling table entry is inline inside
1551
  // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
1552
  // the table points at an offset in the exception handling table (section 5
1553
  // EHABI).
1554
  pint_t exceptionTableAddr;
1555
  uint32_t exceptionTableData;
1556
  bool isSingleWordEHT;
1557
  if (indexData & 0x80000000) {
1558
    exceptionTableAddr = indexDataAddr;
1559
    // TODO(ajwong): Should this data be 0?
1560
    exceptionTableData = indexData;
1561
    isSingleWordEHT = true;
1562
  } else {
1563
    exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
1564
    exceptionTableData = _addressSpace.get32(exceptionTableAddr);
1565
    isSingleWordEHT = false;
1566
  }
1567

1568
  // Now we know the 3 things:
1569
  //   exceptionTableAddr -- exception handler table entry.
1570
  //   exceptionTableData -- the data inside the first word of the eht entry.
1571
  //   isSingleWordEHT -- whether the entry is in the index.
1572
  unw_word_t personalityRoutine = 0xbadf00d;
1573
  bool scope32 = false;
1574
  uintptr_t lsda;
1575

1576
  // If the high bit in the exception handling table entry is set, the entry is
1577
  // in compact form (section 6.3 EHABI).
1578
  if (exceptionTableData & 0x80000000) {
1579
    // Grab the index of the personality routine from the compact form.
1580
    uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
1581
    uint32_t extraWords = 0;
1582
    switch (choice) {
1583
      case 0:
1584
        personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
1585
        extraWords = 0;
1586
        scope32 = false;
1587
        lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
1588
        break;
1589
      case 1:
1590
        personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
1591
        extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1592
        scope32 = false;
1593
        lsda = exceptionTableAddr + (extraWords + 1) * 4;
1594
        break;
1595
      case 2:
1596
        personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
1597
        extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1598
        scope32 = true;
1599
        lsda = exceptionTableAddr + (extraWords + 1) * 4;
1600
        break;
1601
      default:
1602
        _LIBUNWIND_ABORT("unknown personality routine");
1603
        return false;
1604
    }
1605

1606
    if (isSingleWordEHT) {
1607
      if (extraWords != 0) {
1608
        _LIBUNWIND_ABORT("index inlined table detected but pr function "
1609
                         "requires extra words");
1610
        return false;
1611
      }
1612
    }
1613
  } else {
1614
    pint_t personalityAddr =
1615
        exceptionTableAddr + signExtendPrel31(exceptionTableData);
1616
    personalityRoutine = personalityAddr;
1617

1618
    // ARM EHABI # 6.2, # 9.2
1619
    //
1620
    //  +---- ehtp
1621
    //  v
1622
    // +--------------------------------------+
1623
    // | +--------+--------+--------+-------+ |
1624
    // | |0| prel31 to personalityRoutine   | |
1625
    // | +--------+--------+--------+-------+ |
1626
    // | |      N |      unwind opcodes     | |  <-- UnwindData
1627
    // | +--------+--------+--------+-------+ |
1628
    // | | Word 2        unwind opcodes     | |
1629
    // | +--------+--------+--------+-------+ |
1630
    // | ...                                  |
1631
    // | +--------+--------+--------+-------+ |
1632
    // | | Word N        unwind opcodes     | |
1633
    // | +--------+--------+--------+-------+ |
1634
    // | | LSDA                             | |  <-- lsda
1635
    // | | ...                              | |
1636
    // | +--------+--------+--------+-------+ |
1637
    // +--------------------------------------+
1638

1639
    uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
1640
    uint32_t FirstDataWord = *UnwindData;
1641
    size_t N = ((FirstDataWord >> 24) & 0xff);
1642
    size_t NDataWords = N + 1;
1643
    lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
1644
  }
1645

1646
  _info.start_ip = thisPC;
1647
  _info.end_ip = nextPC;
1648
  _info.handler = personalityRoutine;
1649
  _info.unwind_info = exceptionTableAddr;
1650
  _info.lsda = lsda;
1651
  // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
1652
  _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0);  // Use enum?
1653

1654
  return true;
1655
}
1656
#endif
1657

1658
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1659
template <typename A, typename R>
1660
bool UnwindCursor<A, R>::getInfoFromFdeCie(
1661
    const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1662
    const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc,
1663
    uintptr_t dso_base) {
1664
  typename CFI_Parser<A>::PrologInfo prolog;
1665
  if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
1666
                                          R::getArch(), &prolog)) {
1667
    // Save off parsed FDE info
1668
    _info.start_ip          = fdeInfo.pcStart;
1669
    _info.end_ip            = fdeInfo.pcEnd;
1670
    _info.lsda              = fdeInfo.lsda;
1671
    _info.handler           = cieInfo.personality;
1672
    // Some frameless functions need SP altered when resuming in function, so
1673
    // propagate spExtraArgSize.
1674
    _info.gp                = prolog.spExtraArgSize;
1675
    _info.flags             = 0;
1676
    _info.format            = dwarfEncoding();
1677
    _info.unwind_info       = fdeInfo.fdeStart;
1678
    _info.unwind_info_size  = static_cast<uint32_t>(fdeInfo.fdeLength);
1679
    _info.extra             = static_cast<unw_word_t>(dso_base);
1680
    return true;
1681
  }
1682
  return false;
1683
}
1684

1685
template <typename A, typename R>
1686
bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
1687
                                                const UnwindInfoSections &sects,
1688
                                                uint32_t fdeSectionOffsetHint) {
1689
  typename CFI_Parser<A>::FDE_Info fdeInfo;
1690
  typename CFI_Parser<A>::CIE_Info cieInfo;
1691
  bool foundFDE = false;
1692
  bool foundInCache = false;
1693
  // If compact encoding table gave offset into dwarf section, go directly there
1694
  if (fdeSectionOffsetHint != 0) {
1695
    foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1696
                                    sects.dwarf_section_length,
1697
                                    sects.dwarf_section + fdeSectionOffsetHint,
1698
                                    &fdeInfo, &cieInfo);
1699
  }
1700
#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1701
  if (!foundFDE && (sects.dwarf_index_section != 0)) {
1702
    foundFDE = EHHeaderParser<A>::findFDE(
1703
        _addressSpace, pc, sects.dwarf_index_section,
1704
        (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
1705
  }
1706
#endif
1707
  if (!foundFDE) {
1708
    // otherwise, search cache of previously found FDEs.
1709
    pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
1710
    if (cachedFDE != 0) {
1711
      foundFDE =
1712
          CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1713
                                 sects.dwarf_section_length,
1714
                                 cachedFDE, &fdeInfo, &cieInfo);
1715
      foundInCache = foundFDE;
1716
    }
1717
  }
1718
  if (!foundFDE) {
1719
    // Still not found, do full scan of __eh_frame section.
1720
    foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1721
                                      sects.dwarf_section_length, 0,
1722
                                      &fdeInfo, &cieInfo);
1723
  }
1724
  if (foundFDE) {
1725
    if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) {
1726
      // Add to cache (to make next lookup faster) if we had no hint
1727
      // and there was no index.
1728
      if (!foundInCache && (fdeSectionOffsetHint == 0)) {
1729
  #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1730
        if (sects.dwarf_index_section == 0)
1731
  #endif
1732
        DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
1733
                              fdeInfo.fdeStart);
1734
      }
1735
      return true;
1736
    }
1737
  }
1738
  //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
1739
  return false;
1740
}
1741
#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1742

1743

1744
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1745
template <typename A, typename R>
1746
bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
1747
                                              const UnwindInfoSections &sects) {
1748
  const bool log = false;
1749
  if (log)
1750
    fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
1751
            (uint64_t)pc, (uint64_t)sects.dso_base);
1752

1753
  const UnwindSectionHeader<A> sectionHeader(_addressSpace,
1754
                                                sects.compact_unwind_section);
1755
  if (sectionHeader.version() != UNWIND_SECTION_VERSION)
1756
    return false;
1757

1758
  // do a binary search of top level index to find page with unwind info
1759
  pint_t targetFunctionOffset = pc - sects.dso_base;
1760
  const UnwindSectionIndexArray<A> topIndex(_addressSpace,
1761
                                           sects.compact_unwind_section
1762
                                         + sectionHeader.indexSectionOffset());
1763
  uint32_t low = 0;
1764
  uint32_t high = sectionHeader.indexCount();
1765
  uint32_t last = high - 1;
1766
  while (low < high) {
1767
    uint32_t mid = (low + high) / 2;
1768
    //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
1769
    //mid, low, high, topIndex.functionOffset(mid));
1770
    if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
1771
      if ((mid == last) ||
1772
          (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
1773
        low = mid;
1774
        break;
1775
      } else {
1776
        low = mid + 1;
1777
      }
1778
    } else {
1779
      high = mid;
1780
    }
1781
  }
1782
  const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
1783
  const uint32_t firstLevelNextPageFunctionOffset =
1784
      topIndex.functionOffset(low + 1);
1785
  const pint_t secondLevelAddr =
1786
      sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
1787
  const pint_t lsdaArrayStartAddr =
1788
      sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
1789
  const pint_t lsdaArrayEndAddr =
1790
      sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
1791
  if (log)
1792
    fprintf(stderr, "\tfirst level search for result index=%d "
1793
                    "to secondLevelAddr=0x%llX\n",
1794
                    low, (uint64_t) secondLevelAddr);
1795
  // do a binary search of second level page index
1796
  uint32_t encoding = 0;
1797
  pint_t funcStart = 0;
1798
  pint_t funcEnd = 0;
1799
  pint_t lsda = 0;
1800
  pint_t personality = 0;
1801
  uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
1802
  if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
1803
    // regular page
1804
    UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
1805
                                                 secondLevelAddr);
1806
    UnwindSectionRegularArray<A> pageIndex(
1807
        _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1808
    // binary search looks for entry with e where index[e].offset <= pc <
1809
    // index[e+1].offset
1810
    if (log)
1811
      fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
1812
                      "regular page starting at secondLevelAddr=0x%llX\n",
1813
              (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
1814
    low = 0;
1815
    high = pageHeader.entryCount();
1816
    while (low < high) {
1817
      uint32_t mid = (low + high) / 2;
1818
      if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
1819
        if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
1820
          // at end of table
1821
          low = mid;
1822
          funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1823
          break;
1824
        } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
1825
          // next is too big, so we found it
1826
          low = mid;
1827
          funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
1828
          break;
1829
        } else {
1830
          low = mid + 1;
1831
        }
1832
      } else {
1833
        high = mid;
1834
      }
1835
    }
1836
    encoding = pageIndex.encoding(low);
1837
    funcStart = pageIndex.functionOffset(low) + sects.dso_base;
1838
    if (pc < funcStart) {
1839
      if (log)
1840
        fprintf(
1841
            stderr,
1842
            "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1843
            (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1844
      return false;
1845
    }
1846
    if (pc > funcEnd) {
1847
      if (log)
1848
        fprintf(
1849
            stderr,
1850
            "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1851
            (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1852
      return false;
1853
    }
1854
  } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
1855
    // compressed page
1856
    UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
1857
                                                    secondLevelAddr);
1858
    UnwindSectionCompressedArray<A> pageIndex(
1859
        _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1860
    const uint32_t targetFunctionPageOffset =
1861
        (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
1862
    // binary search looks for entry with e where index[e].offset <= pc <
1863
    // index[e+1].offset
1864
    if (log)
1865
      fprintf(stderr, "\tbinary search of compressed page starting at "
1866
                      "secondLevelAddr=0x%llX\n",
1867
              (uint64_t) secondLevelAddr);
1868
    low = 0;
1869
    last = pageHeader.entryCount() - 1;
1870
    high = pageHeader.entryCount();
1871
    while (low < high) {
1872
      uint32_t mid = (low + high) / 2;
1873
      if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
1874
        if ((mid == last) ||
1875
            (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
1876
          low = mid;
1877
          break;
1878
        } else {
1879
          low = mid + 1;
1880
        }
1881
      } else {
1882
        high = mid;
1883
      }
1884
    }
1885
    funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
1886
                                                              + sects.dso_base;
1887
    if (low < last)
1888
      funcEnd =
1889
          pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
1890
                                                              + sects.dso_base;
1891
    else
1892
      funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1893
    if (pc < funcStart) {
1894
      _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1895
                           "not in second level compressed unwind table. "
1896
                           "funcStart=0x%llX",
1897
                            (uint64_t) pc, (uint64_t) funcStart);
1898
      return false;
1899
    }
1900
    if (pc > funcEnd) {
1901
      _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1902
                           "not in second level compressed unwind table. "
1903
                           "funcEnd=0x%llX",
1904
                           (uint64_t) pc, (uint64_t) funcEnd);
1905
      return false;
1906
    }
1907
    uint16_t encodingIndex = pageIndex.encodingIndex(low);
1908
    if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
1909
      // encoding is in common table in section header
1910
      encoding = _addressSpace.get32(
1911
          sects.compact_unwind_section +
1912
          sectionHeader.commonEncodingsArraySectionOffset() +
1913
          encodingIndex * sizeof(uint32_t));
1914
    } else {
1915
      // encoding is in page specific table
1916
      uint16_t pageEncodingIndex =
1917
          encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
1918
      encoding = _addressSpace.get32(secondLevelAddr +
1919
                                     pageHeader.encodingsPageOffset() +
1920
                                     pageEncodingIndex * sizeof(uint32_t));
1921
    }
1922
  } else {
1923
    _LIBUNWIND_DEBUG_LOG(
1924
        "malformed __unwind_info at 0x%0llX bad second level page",
1925
        (uint64_t)sects.compact_unwind_section);
1926
    return false;
1927
  }
1928

1929
  // look up LSDA, if encoding says function has one
1930
  if (encoding & UNWIND_HAS_LSDA) {
1931
    UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
1932
    uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
1933
    low = 0;
1934
    high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
1935
                    sizeof(unwind_info_section_header_lsda_index_entry);
1936
    // binary search looks for entry with exact match for functionOffset
1937
    if (log)
1938
      fprintf(stderr,
1939
              "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
1940
              funcStartOffset);
1941
    while (low < high) {
1942
      uint32_t mid = (low + high) / 2;
1943
      if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
1944
        lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
1945
        break;
1946
      } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
1947
        low = mid + 1;
1948
      } else {
1949
        high = mid;
1950
      }
1951
    }
1952
    if (lsda == 0) {
1953
      _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
1954
                    "pc=0x%0llX, but lsda table has no entry",
1955
                    encoding, (uint64_t) pc);
1956
      return false;
1957
    }
1958
  }
1959

1960
  // extract personality routine, if encoding says function has one
1961
  uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
1962
                              (__builtin_ctz(UNWIND_PERSONALITY_MASK));
1963
  if (personalityIndex != 0) {
1964
    --personalityIndex; // change 1-based to zero-based index
1965
    if (personalityIndex >= sectionHeader.personalityArrayCount()) {
1966
      _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d,  "
1967
                            "but personality table has only %d entries",
1968
                            encoding, personalityIndex,
1969
                            sectionHeader.personalityArrayCount());
1970
      return false;
1971
    }
1972
    int32_t personalityDelta = (int32_t)_addressSpace.get32(
1973
        sects.compact_unwind_section +
1974
        sectionHeader.personalityArraySectionOffset() +
1975
        personalityIndex * sizeof(uint32_t));
1976
    pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
1977
    personality = _addressSpace.getP(personalityPointer);
1978
    if (log)
1979
      fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1980
                      "personalityDelta=0x%08X, personality=0x%08llX\n",
1981
              (uint64_t) pc, personalityDelta, (uint64_t) personality);
1982
  }
1983

1984
  if (log)
1985
    fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1986
                    "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
1987
            (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
1988
  _info.start_ip = funcStart;
1989
  _info.end_ip = funcEnd;
1990
  _info.lsda = lsda;
1991
  _info.handler = personality;
1992
  _info.gp = 0;
1993
  _info.flags = 0;
1994
  _info.format = encoding;
1995
  _info.unwind_info = 0;
1996
  _info.unwind_info_size = 0;
1997
  _info.extra = sects.dso_base;
1998
  return true;
1999
}
2000
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2001

2002

2003
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2004
template <typename A, typename R>
2005
bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
2006
  pint_t base;
2007
  RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
2008
  if (!unwindEntry) {
2009
    _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
2010
    return false;
2011
  }
2012
  _info.gp = 0;
2013
  _info.flags = 0;
2014
  _info.format = 0;
2015
  _info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
2016
  _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
2017
  _info.extra = base;
2018
  _info.start_ip = base + unwindEntry->BeginAddress;
2019
#ifdef _LIBUNWIND_TARGET_X86_64
2020
  _info.end_ip = base + unwindEntry->EndAddress;
2021
  // Only fill in the handler and LSDA if they're stale.
2022
  if (pc != getLastPC()) {
2023
    UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
2024
    if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
2025
      // The personality is given in the UNWIND_INFO itself. The LSDA immediately
2026
      // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
2027
      // these structures.)
2028
      // N.B. UNWIND_INFO structs are DWORD-aligned.
2029
      uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
2030
      const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
2031
      _info.lsda = reinterpret_cast<unw_word_t>(handler+1);
2032
      _dispContext.HandlerData = reinterpret_cast<void *>(_info.lsda);
2033
      _dispContext.LanguageHandler =
2034
          reinterpret_cast<EXCEPTION_ROUTINE *>(base + *handler);
2035
      if (*handler) {
2036
        _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2037
      } else
2038
        _info.handler = 0;
2039
    } else {
2040
      _info.lsda = 0;
2041
      _info.handler = 0;
2042
    }
2043
  }
2044
#elif defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_ARM)
2045

2046
#if defined(_LIBUNWIND_TARGET_AARCH64)
2047
#define FUNC_LENGTH_UNIT 4
2048
#define XDATA_TYPE IMAGE_ARM64_RUNTIME_FUNCTION_ENTRY_XDATA
2049
#else
2050
#define FUNC_LENGTH_UNIT 2
2051
#define XDATA_TYPE UNWIND_INFO_ARM
2052
#endif
2053
  if (unwindEntry->Flag != 0) { // Packed unwind info
2054
    _info.end_ip =
2055
        _info.start_ip + unwindEntry->FunctionLength * FUNC_LENGTH_UNIT;
2056
    // Only fill in the handler and LSDA if they're stale.
2057
    if (pc != getLastPC()) {
2058
      // Packed unwind info doesn't have an exception handler.
2059
      _info.lsda = 0;
2060
      _info.handler = 0;
2061
    }
2062
  } else {
2063
    XDATA_TYPE *xdata =
2064
        reinterpret_cast<XDATA_TYPE *>(base + unwindEntry->UnwindData);
2065
    _info.end_ip = _info.start_ip + xdata->FunctionLength * FUNC_LENGTH_UNIT;
2066
    // Only fill in the handler and LSDA if they're stale.
2067
    if (pc != getLastPC()) {
2068
      if (xdata->ExceptionDataPresent) {
2069
        uint32_t offset = 1; // The main xdata
2070
        uint32_t codeWords = xdata->CodeWords;
2071
        uint32_t epilogScopes = xdata->EpilogCount;
2072
        if (xdata->EpilogCount == 0 && xdata->CodeWords == 0) {
2073
          // The extension word has got the same layout for both ARM and ARM64
2074
          uint32_t extensionWord = reinterpret_cast<uint32_t *>(xdata)[1];
2075
          codeWords = (extensionWord >> 16) & 0xff;
2076
          epilogScopes = extensionWord & 0xffff;
2077
          offset++;
2078
        }
2079
        if (!xdata->EpilogInHeader)
2080
          offset += epilogScopes;
2081
        offset += codeWords;
2082
        uint32_t *exceptionHandlerInfo =
2083
            reinterpret_cast<uint32_t *>(xdata) + offset;
2084
        _dispContext.HandlerData = &exceptionHandlerInfo[1];
2085
        _dispContext.LanguageHandler = reinterpret_cast<EXCEPTION_ROUTINE *>(
2086
            base + exceptionHandlerInfo[0]);
2087
        _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
2088
        if (exceptionHandlerInfo[0])
2089
          _info.handler =
2090
              reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2091
        else
2092
          _info.handler = 0;
2093
      } else {
2094
        _info.lsda = 0;
2095
        _info.handler = 0;
2096
      }
2097
    }
2098
  }
2099
#endif
2100
  setLastPC(pc);
2101
  return true;
2102
}
2103
#endif
2104

2105
#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2106
// Masks for traceback table field xtbtable.
2107
enum xTBTableMask : uint8_t {
2108
  reservedBit = 0x02, // The traceback table was incorrectly generated if set
2109
                      // (see comments in function getInfoFromTBTable().
2110
  ehInfoBit = 0x08    // Exception handling info is present if set
2111
};
2112

2113
enum frameType : unw_word_t {
2114
  frameWithXLEHStateTable = 0,
2115
  frameWithEHInfo = 1
2116
};
2117

2118
extern "C" {
2119
typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
2120
                                                     uint64_t,
2121
                                                     _Unwind_Exception *,
2122
                                                     struct _Unwind_Context *);
2123
}
2124

2125
static __xlcxx_personality_v0_t *xlcPersonalityV0;
2126
static RWMutex xlcPersonalityV0InitLock;
2127

2128
template <typename A, typename R>
2129
bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R &registers) {
2130
  uint32_t *p = reinterpret_cast<uint32_t *>(pc);
2131

2132
  // Keep looking forward until a word of 0 is found. The traceback
2133
  // table starts at the following word.
2134
  while (*p)
2135
    ++p;
2136
  tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
2137

2138
  if (_LIBUNWIND_TRACING_UNWINDING) {
2139
    char functionBuf[512];
2140
    const char *functionName = functionBuf;
2141
    unw_word_t offset;
2142
    if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2143
      functionName = ".anonymous.";
2144
    }
2145
    _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2146
                               __func__, functionName,
2147
                               reinterpret_cast<void *>(TBTable));
2148
  }
2149

2150
  // If the traceback table does not contain necessary info, bypass this frame.
2151
  if (!TBTable->tb.has_tboff)
2152
    return false;
2153

2154
  // Structure tbtable_ext contains important data we are looking for.
2155
  p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2156

2157
  // Skip field parminfo if it exists.
2158
  if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2159
    ++p;
2160

2161
  // p now points to tb_offset, the offset from start of function to TB table.
2162
  unw_word_t start_ip =
2163
      reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
2164
  unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
2165
  ++p;
2166

2167
  _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
2168
                             reinterpret_cast<void *>(start_ip),
2169
                             reinterpret_cast<void *>(end_ip));
2170

2171
  // Skip field hand_mask if it exists.
2172
  if (TBTable->tb.int_hndl)
2173
    ++p;
2174

2175
  unw_word_t lsda = 0;
2176
  unw_word_t handler = 0;
2177
  unw_word_t flags = frameType::frameWithXLEHStateTable;
2178

2179
  if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
2180
    // State table info is available. The ctl_info field indicates the
2181
    // number of CTL anchors. There should be only one entry for the C++
2182
    // state table.
2183
    assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
2184
    ++p;
2185
    // p points to the offset of the state table into the stack.
2186
    pint_t stateTableOffset = *p++;
2187

2188
    int framePointerReg;
2189

2190
    // Skip fields name_len and name if exist.
2191
    if (TBTable->tb.name_present) {
2192
      const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
2193
      p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
2194
                                       sizeof(uint16_t));
2195
    }
2196

2197
    if (TBTable->tb.uses_alloca)
2198
      framePointerReg = *(reinterpret_cast<char *>(p));
2199
    else
2200
      framePointerReg = 1; // default frame pointer == SP
2201

2202
    _LIBUNWIND_TRACE_UNWINDING(
2203
        "framePointerReg=%d, framePointer=%p, "
2204
        "stateTableOffset=%#lx\n",
2205
        framePointerReg,
2206
        reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
2207
        stateTableOffset);
2208
    lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
2209

2210
    // Since the traceback table generated by the legacy XLC++ does not
2211
    // provide the location of the personality for the state table,
2212
    // function __xlcxx_personality_v0(), which is the personality for the state
2213
    // table and is exported from libc++abi, is directly assigned as the
2214
    // handler here. When a legacy XLC++ frame is encountered, the symbol
2215
    // is resolved dynamically using dlopen() to avoid a hard dependency of
2216
    // libunwind on libc++abi in cases such as non-C++ applications.
2217

2218
    // Resolve the function pointer to the state table personality if it has
2219
    // not already been done.
2220
    if (xlcPersonalityV0 == NULL) {
2221
      xlcPersonalityV0InitLock.lock();
2222
      if (xlcPersonalityV0 == NULL) {
2223
        // Resolve __xlcxx_personality_v0 using dlopen().
2224
        const char *libcxxabi = "libc++abi.a(libc++abi.so.1)";
2225
        void *libHandle;
2226
        // The AIX dlopen() sets errno to 0 when it is successful, which
2227
        // clobbers the value of errno from the user code. This is an AIX
2228
        // bug because according to POSIX it should not set errno to 0. To
2229
        // workaround before AIX fixes the bug, errno is saved and restored.
2230
        int saveErrno = errno;
2231
        libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
2232
        if (libHandle == NULL) {
2233
          _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n", errno);
2234
          assert(0 && "dlopen() failed");
2235
        }
2236
        xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
2237
            dlsym(libHandle, "__xlcxx_personality_v0"));
2238
        if (xlcPersonalityV0 == NULL) {
2239
          _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
2240
          dlclose(libHandle);
2241
          assert(0 && "dlsym() failed");
2242
        }
2243
        errno = saveErrno;
2244
      }
2245
      xlcPersonalityV0InitLock.unlock();
2246
    }
2247
    handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
2248
    _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
2249
                               reinterpret_cast<void *>(lsda),
2250
                               reinterpret_cast<void *>(handler));
2251
  } else if (TBTable->tb.longtbtable) {
2252
    // This frame has the traceback table extension. Possible cases are
2253
    // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
2254
    // is not EH aware; or, 3) a frame of other languages. We need to figure out
2255
    // if the traceback table extension contains the 'eh_info' structure.
2256
    //
2257
    // We also need to deal with the complexity arising from some XL compiler
2258
    // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
2259
    // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
2260
    // versa. For frames of code generated by those compilers, the 'longtbtable'
2261
    // bit may be set but there isn't really a traceback table extension.
2262
    //
2263
    // In </usr/include/sys/debug.h>, there is the following definition of
2264
    // 'struct tbtable_ext'. It is not really a structure but a dummy to
2265
    // collect the description of optional parts of the traceback table.
2266
    //
2267
    // struct tbtable_ext {
2268
    //   ...
2269
    //   char alloca_reg;        /* Register for alloca automatic storage */
2270
    //   struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
2271
    //   unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
2272
    // };
2273
    //
2274
    // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
2275
    // following 'alloca_reg' can be treated either as 'struct vec_ext' or
2276
    // 'unsigned char xtbtable'. 'xtbtable' bits are defined in
2277
    // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
2278
    // unused and should not be set. 'struct vec_ext' is defined in
2279
    // </usr/include/sys/debug.h> as follows:
2280
    //
2281
    // struct vec_ext {
2282
    //   unsigned vr_saved:6;      /* Number of non-volatile vector regs saved
2283
    //   */
2284
    //                             /* first register saved is assumed to be */
2285
    //                             /* 32 - vr_saved                         */
2286
    //   unsigned saves_vrsave:1;  /* Set if vrsave is saved on the stack */
2287
    //   unsigned has_varargs:1;
2288
    //   ...
2289
    // };
2290
    //
2291
    // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
2292
    // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
2293
    // we checks if the 7th bit is set or not because 'xtbtable' should
2294
    // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
2295
    // in the future to make sure the mitigation works. This mitigation
2296
    // is not 100% bullet proof because 'struct vec_ext' may not always have
2297
    // 'saves_vrsave' bit set.
2298
    //
2299
    // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
2300
    // checking the 7th bit.
2301

2302
    // p points to field name len.
2303
    uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2304

2305
    // Skip fields name_len and name if they exist.
2306
    if (TBTable->tb.name_present) {
2307
      const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2308
      charPtr = charPtr + name_len + sizeof(uint16_t);
2309
    }
2310

2311
    // Skip field alloc_reg if it exists.
2312
    if (TBTable->tb.uses_alloca)
2313
      ++charPtr;
2314

2315
    // Check traceback table bit has_vec. Skip struct vec_ext if it exists.
2316
    if (TBTable->tb.has_vec)
2317
      // Note struct vec_ext does exist at this point because whether the
2318
      // ordering of longtbtable and has_vec bits is correct or not, both
2319
      // are set.
2320
      charPtr += sizeof(struct vec_ext);
2321

2322
    // charPtr points to field 'xtbtable'. Check if the EH info is available.
2323
    // Also check if the reserved bit of the extended traceback table field
2324
    // 'xtbtable' is set. If it is, the traceback table was incorrectly
2325
    // generated by an XL compiler that uses the wrong ordering of 'longtbtable'
2326
    // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
2327
    // frame.
2328
    if ((*charPtr & xTBTableMask::ehInfoBit) &&
2329
        !(*charPtr & xTBTableMask::reservedBit)) {
2330
      // Mark this frame has the new EH info.
2331
      flags = frameType::frameWithEHInfo;
2332

2333
      // eh_info is available.
2334
      charPtr++;
2335
      // The pointer is 4-byte aligned.
2336
      if (reinterpret_cast<uintptr_t>(charPtr) % 4)
2337
        charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
2338
      uintptr_t *ehInfo =
2339
          reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
2340
              registers.getRegister(2) +
2341
              *(reinterpret_cast<uintptr_t *>(charPtr)))));
2342

2343
      // ehInfo points to structure en_info. The first member is version.
2344
      // Only version 0 is currently supported.
2345
      assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
2346
             "libunwind: ehInfo version other than 0 is not supported");
2347

2348
      // Increment ehInfo to point to member lsda.
2349
      ++ehInfo;
2350
      lsda = *ehInfo++;
2351

2352
      // enInfo now points to member personality.
2353
      handler = *ehInfo;
2354

2355
      _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
2356
                                 lsda, handler);
2357
    }
2358
  }
2359

2360
  _info.start_ip = start_ip;
2361
  _info.end_ip = end_ip;
2362
  _info.lsda = lsda;
2363
  _info.handler = handler;
2364
  _info.gp = 0;
2365
  _info.flags = flags;
2366
  _info.format = 0;
2367
  _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
2368
  _info.unwind_info_size = 0;
2369
  _info.extra = registers.getRegister(2);
2370

2371
  return true;
2372
}
2373

2374
// Step back up the stack following the frame back link.
2375
template <typename A, typename R>
2376
int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
2377
                                        R &registers, bool &isSignalFrame) {
2378
  if (_LIBUNWIND_TRACING_UNWINDING) {
2379
    char functionBuf[512];
2380
    const char *functionName = functionBuf;
2381
    unw_word_t offset;
2382
    if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2383
      functionName = ".anonymous.";
2384
    }
2385
    _LIBUNWIND_TRACE_UNWINDING(
2386
        "%s: Look up traceback table of func=%s at %p, pc=%p, "
2387
        "SP=%p, saves_lr=%d, stores_bc=%d",
2388
        __func__, functionName, reinterpret_cast<void *>(TBTable),
2389
        reinterpret_cast<void *>(pc),
2390
        reinterpret_cast<void *>(registers.getSP()), TBTable->tb.saves_lr,
2391
        TBTable->tb.stores_bc);
2392
  }
2393

2394
#if defined(__powerpc64__)
2395
  // Instruction to reload TOC register "ld r2,40(r1)"
2396
  const uint32_t loadTOCRegInst = 0xe8410028;
2397
  const int32_t unwPPCF0Index = UNW_PPC64_F0;
2398
  const int32_t unwPPCV0Index = UNW_PPC64_V0;
2399
#else
2400
  // Instruction to reload TOC register "lwz r2,20(r1)"
2401
  const uint32_t loadTOCRegInst = 0x80410014;
2402
  const int32_t unwPPCF0Index = UNW_PPC_F0;
2403
  const int32_t unwPPCV0Index = UNW_PPC_V0;
2404
#endif
2405

2406
  // lastStack points to the stack frame of the next routine up.
2407
  pint_t curStack = static_cast<pint_t>(registers.getSP());
2408
  pint_t lastStack = *reinterpret_cast<pint_t *>(curStack);
2409

2410
  if (lastStack == 0)
2411
    return UNW_STEP_END;
2412

2413
  R newRegisters = registers;
2414

2415
  // If backchain is not stored, use the current stack frame.
2416
  if (!TBTable->tb.stores_bc)
2417
    lastStack = curStack;
2418

2419
  // Return address is the address after call site instruction.
2420
  pint_t returnAddress;
2421

2422
  if (isSignalFrame) {
2423
    _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
2424
                               reinterpret_cast<void *>(lastStack));
2425

2426
    sigcontext *sigContext = reinterpret_cast<sigcontext *>(
2427
        reinterpret_cast<char *>(lastStack) + STKMINALIGN);
2428
    returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2429

2430
    bool useSTKMIN = false;
2431
    if (returnAddress < 0x10000000) {
2432
      // Try again using STKMIN.
2433
      sigContext = reinterpret_cast<sigcontext *>(
2434
          reinterpret_cast<char *>(lastStack) + STKMIN);
2435
      returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2436
      if (returnAddress < 0x10000000) {
2437
        _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p from sigcontext=%p",
2438
                                   reinterpret_cast<void *>(returnAddress),
2439
                                   reinterpret_cast<void *>(sigContext));
2440
        return UNW_EBADFRAME;
2441
      }
2442
      useSTKMIN = true;
2443
    }
2444
    _LIBUNWIND_TRACE_UNWINDING("Returning from a signal handler %s: "
2445
                               "sigContext=%p, returnAddress=%p. "
2446
                               "Seems to be a valid address",
2447
                               useSTKMIN ? "STKMIN" : "STKMINALIGN",
2448
                               reinterpret_cast<void *>(sigContext),
2449
                               reinterpret_cast<void *>(returnAddress));
2450

2451
    // Restore the condition register from sigcontext.
2452
    newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
2453

2454
    // Save the LR in sigcontext for stepping up when the function that
2455
    // raised the signal is a leaf function. This LR has the return address
2456
    // to the caller of the leaf function.
2457
    newRegisters.setLR(sigContext->sc_jmpbuf.jmp_context.lr);
2458
    _LIBUNWIND_TRACE_UNWINDING(
2459
        "Save LR=%p from sigcontext",
2460
        reinterpret_cast<void *>(sigContext->sc_jmpbuf.jmp_context.lr));
2461

2462
    // Restore GPRs from sigcontext.
2463
    for (int i = 0; i < 32; ++i)
2464
      newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
2465

2466
    // Restore FPRs from sigcontext.
2467
    for (int i = 0; i < 32; ++i)
2468
      newRegisters.setFloatRegister(i + unwPPCF0Index,
2469
                                    sigContext->sc_jmpbuf.jmp_context.fpr[i]);
2470

2471
    // Restore vector registers if there is an associated extended context
2472
    // structure.
2473
    if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
2474
      ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
2475
      if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
2476
        for (int i = 0; i < 32; ++i)
2477
          newRegisters.setVectorRegister(
2478
              i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
2479
                                     &(uContext->__extctx->__vmx.__vr[i]))));
2480
      }
2481
    }
2482
  } else {
2483
    // Step up a normal frame.
2484

2485
    if (!TBTable->tb.saves_lr && registers.getLR()) {
2486
      // This case should only occur if we were called from a signal handler
2487
      // and the signal occurred in a function that doesn't save the LR.
2488
      returnAddress = static_cast<pint_t>(registers.getLR());
2489
      _LIBUNWIND_TRACE_UNWINDING("Use saved LR=%p",
2490
                                 reinterpret_cast<void *>(returnAddress));
2491
    } else {
2492
      // Otherwise, use the LR value in the stack link area.
2493
      returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
2494
    }
2495

2496
    // Reset LR in the current context.
2497
    newRegisters.setLR(static_cast<uintptr_t>(NULL));
2498

2499
    _LIBUNWIND_TRACE_UNWINDING(
2500
        "Extract info from lastStack=%p, returnAddress=%p",
2501
        reinterpret_cast<void *>(lastStack),
2502
        reinterpret_cast<void *>(returnAddress));
2503
    _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d",
2504
                               TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
2505
                               TBTable->tb.saves_cr);
2506

2507
    // Restore FP registers.
2508
    char *ptrToRegs = reinterpret_cast<char *>(lastStack);
2509
    double *FPRegs = reinterpret_cast<double *>(
2510
        ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
2511
    for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
2512
      newRegisters.setFloatRegister(
2513
          32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
2514

2515
    // Restore GP registers.
2516
    ptrToRegs = reinterpret_cast<char *>(FPRegs);
2517
    uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
2518
        ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
2519
    for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
2520
      newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
2521

2522
    // Restore Vector registers.
2523
    ptrToRegs = reinterpret_cast<char *>(GPRegs);
2524

2525
    // Restore vector registers only if this is a Clang frame. Also
2526
    // check if traceback table bit has_vec is set. If it is, structure
2527
    // vec_ext is available.
2528
    if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
2529

2530
      // Get to the vec_ext structure to check if vector registers are saved.
2531
      uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2532

2533
      // Skip field parminfo if exists.
2534
      if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2535
        ++p;
2536

2537
      // Skip field tb_offset if exists.
2538
      if (TBTable->tb.has_tboff)
2539
        ++p;
2540

2541
      // Skip field hand_mask if exists.
2542
      if (TBTable->tb.int_hndl)
2543
        ++p;
2544

2545
      // Skip fields ctl_info and ctl_info_disp if exist.
2546
      if (TBTable->tb.has_ctl) {
2547
        // Skip field ctl_info.
2548
        ++p;
2549
        // Skip field ctl_info_disp.
2550
        ++p;
2551
      }
2552

2553
      // Skip fields name_len and name if exist.
2554
      // p is supposed to point to field name_len now.
2555
      uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2556
      if (TBTable->tb.name_present) {
2557
        const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2558
        charPtr = charPtr + name_len + sizeof(uint16_t);
2559
      }
2560

2561
      // Skip field alloc_reg if it exists.
2562
      if (TBTable->tb.uses_alloca)
2563
        ++charPtr;
2564

2565
      struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
2566

2567
      _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d", vec_ext->vr_saved);
2568

2569
      // Restore vector register(s) if saved on the stack.
2570
      if (vec_ext->vr_saved) {
2571
        // Saved vector registers are 16-byte aligned.
2572
        if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
2573
          ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
2574
        v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
2575
                                                                 sizeof(v128));
2576
        for (int i = 0; i < vec_ext->vr_saved; ++i) {
2577
          newRegisters.setVectorRegister(
2578
              32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
2579
        }
2580
      }
2581
    }
2582
    if (TBTable->tb.saves_cr) {
2583
      // Get the saved condition register. The condition register is only
2584
      // a single word.
2585
      newRegisters.setCR(
2586
          *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
2587
    }
2588

2589
    // Restore the SP.
2590
    newRegisters.setSP(lastStack);
2591

2592
    // The first instruction after return.
2593
    uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
2594

2595
    // Do we need to set the TOC register?
2596
    _LIBUNWIND_TRACE_UNWINDING(
2597
        "Current gpr2=%p",
2598
        reinterpret_cast<void *>(newRegisters.getRegister(2)));
2599
    if (firstInstruction == loadTOCRegInst) {
2600
      _LIBUNWIND_TRACE_UNWINDING(
2601
          "Set gpr2=%p from frame",
2602
          reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
2603
      newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
2604
    }
2605
  }
2606
  _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
2607
                             reinterpret_cast<void *>(lastStack),
2608
                             reinterpret_cast<void *>(returnAddress),
2609
                             reinterpret_cast<void *>(pc));
2610

2611
  // The return address is the address after call site instruction, so
2612
  // setting IP to that simulates a return.
2613
  newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
2614

2615
  // Simulate the step by replacing the register set with the new ones.
2616
  registers = newRegisters;
2617

2618
  // Check if the next frame is a signal frame.
2619
  pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2620

2621
  // Return address is the address after call site instruction.
2622
  pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
2623

2624
  if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
2625
    _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
2626
                               "nextStack=%p, next return address=%p\n",
2627
                               reinterpret_cast<void *>(nextStack),
2628
                               reinterpret_cast<void *>(nextReturnAddress));
2629
    isSignalFrame = true;
2630
  } else {
2631
    isSignalFrame = false;
2632
  }
2633
  return UNW_STEP_SUCCESS;
2634
}
2635
#endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2636

2637
template <typename A, typename R>
2638
void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
2639
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) ||                               \
2640
    defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
2641
  _isSigReturn = false;
2642
#endif
2643

2644
  pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2645
#if defined(_LIBUNWIND_ARM_EHABI)
2646
  // Remove the thumb bit so the IP represents the actual instruction address.
2647
  // This matches the behaviour of _Unwind_GetIP on arm.
2648
  pc &= (pint_t)~0x1;
2649
#endif
2650

2651
  // Exit early if at the top of the stack.
2652
  if (pc == 0) {
2653
    _unwindInfoMissing = true;
2654
    return;
2655
  }
2656

2657
  // If the last line of a function is a "throw" the compiler sometimes
2658
  // emits no instructions after the call to __cxa_throw.  This means
2659
  // the return address is actually the start of the next function.
2660
  // To disambiguate this, back up the pc when we know it is a return
2661
  // address.
2662
  if (isReturnAddress)
2663
#if defined(_AIX)
2664
    // PC needs to be a 4-byte aligned address to be able to look for a
2665
    // word of 0 that indicates the start of the traceback table at the end
2666
    // of a function on AIX.
2667
    pc -= 4;
2668
#else
2669
    --pc;
2670
#endif
2671

2672
#if !(defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)) &&            \
2673
    !defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2674
  // In case of this is frame of signal handler, the IP saved in the signal
2675
  // handler points to first non-executed instruction, while FDE/CIE expects IP
2676
  // to be after the first non-executed instruction.
2677
  if (_isSignalFrame)
2678
    ++pc;
2679
#endif
2680

2681
  // Ask address space object to find unwind sections for this pc.
2682
  UnwindInfoSections sects;
2683
  if (_addressSpace.findUnwindSections(pc, sects)) {
2684
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2685
    // If there is a compact unwind encoding table, look there first.
2686
    if (sects.compact_unwind_section != 0) {
2687
      if (this->getInfoFromCompactEncodingSection(pc, sects)) {
2688
  #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2689
        // Found info in table, done unless encoding says to use dwarf.
2690
        uint32_t dwarfOffset;
2691
        if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
2692
          if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
2693
            // found info in dwarf, done
2694
            return;
2695
          }
2696
        }
2697
  #endif
2698
        // If unwind table has entry, but entry says there is no unwind info,
2699
        // record that we have no unwind info.
2700
        if (_info.format == 0)
2701
          _unwindInfoMissing = true;
2702
        return;
2703
      }
2704
    }
2705
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2706

2707
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2708
    // If there is SEH unwind info, look there next.
2709
    if (this->getInfoFromSEH(pc))
2710
      return;
2711
#endif
2712

2713
#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2714
    // If there is unwind info in the traceback table, look there next.
2715
    if (this->getInfoFromTBTable(pc, _registers))
2716
      return;
2717
#endif
2718

2719
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2720
    // If there is dwarf unwind info, look there next.
2721
    if (sects.dwarf_section != 0) {
2722
      if (this->getInfoFromDwarfSection(pc, sects)) {
2723
        // found info in dwarf, done
2724
        return;
2725
      }
2726
    }
2727
#endif
2728

2729
#if defined(_LIBUNWIND_ARM_EHABI)
2730
    // If there is ARM EHABI unwind info, look there next.
2731
    if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
2732
      return;
2733
#endif
2734
  }
2735

2736
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2737
  // There is no static unwind info for this pc. Look to see if an FDE was
2738
  // dynamically registered for it.
2739
  pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
2740
                                               pc);
2741
  if (cachedFDE != 0) {
2742
    typename CFI_Parser<A>::FDE_Info fdeInfo;
2743
    typename CFI_Parser<A>::CIE_Info cieInfo;
2744
    if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
2745
      if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2746
        return;
2747
  }
2748

2749
  // Lastly, ask AddressSpace object about platform specific ways to locate
2750
  // other FDEs.
2751
  pint_t fde;
2752
  if (_addressSpace.findOtherFDE(pc, fde)) {
2753
    typename CFI_Parser<A>::FDE_Info fdeInfo;
2754
    typename CFI_Parser<A>::CIE_Info cieInfo;
2755
    if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
2756
      // Double check this FDE is for a function that includes the pc.
2757
      if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
2758
        if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2759
          return;
2760
    }
2761
  }
2762
#endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2763

2764
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) ||                               \
2765
    defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
2766
  if (setInfoForSigReturn())
2767
    return;
2768
#endif
2769

2770
  // no unwind info, flag that we can't reliably unwind
2771
  _unwindInfoMissing = true;
2772
}
2773

2774
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&                               \
2775
    defined(_LIBUNWIND_TARGET_AARCH64)
2776
template <typename A, typename R>
2777
bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
2778
  // Look for the sigreturn trampoline. The trampoline's body is two
2779
  // specific instructions (see below). Typically the trampoline comes from the
2780
  // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
2781
  // own restorer function, though, or user-mode QEMU might write a trampoline
2782
  // onto the stack.
2783
  //
2784
  // This special code path is a fallback that is only used if the trampoline
2785
  // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
2786
  // constant for the PC needs to be defined before DWARF can handle a signal
2787
  // trampoline. This code may segfault if the target PC is unreadable, e.g.:
2788
  //  - The PC points at a function compiled without unwind info, and which is
2789
  //    part of an execute-only mapping (e.g. using -Wl,--execute-only).
2790
  //  - The PC is invalid and happens to point to unreadable or unmapped memory.
2791
  //
2792
  // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
2793
  const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2794
  // The PC might contain an invalid address if the unwind info is bad, so
2795
  // directly accessing it could cause a SIGSEGV.
2796
  if (!isReadableAddr(pc))
2797
    return false;
2798
  auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2799
  // Look for instructions: mov x8, #0x8b; svc #0x0
2800
  if (instructions[0] != 0xd2801168 || instructions[1] != 0xd4000001)
2801
    return false;
2802

2803
  _info = {};
2804
  _info.start_ip = pc;
2805
  _info.end_ip = pc + 4;
2806
  _isSigReturn = true;
2807
  return true;
2808
}
2809

2810
template <typename A, typename R>
2811
int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
2812
  // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2813
  //  - 128-byte siginfo struct
2814
  //  - ucontext struct:
2815
  //     - 8-byte long (uc_flags)
2816
  //     - 8-byte pointer (uc_link)
2817
  //     - 24-byte stack_t
2818
  //     - 128-byte signal set
2819
  //     - 8 bytes of padding because sigcontext has 16-byte alignment
2820
  //     - sigcontext/mcontext_t
2821
  // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
2822
  const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
2823

2824
  // Offsets from sigcontext to each register.
2825
  const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
2826
  const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
2827
  const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
2828

2829
  pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2830

2831
  for (int i = 0; i <= 30; ++i) {
2832
    uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
2833
                                         static_cast<pint_t>(i * 8));
2834
    _registers.setRegister(UNW_AARCH64_X0 + i, value);
2835
  }
2836
  _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
2837
  _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
2838
  _isSignalFrame = true;
2839
  return UNW_STEP_SUCCESS;
2840
}
2841
#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2842
       // defined(_LIBUNWIND_TARGET_AARCH64)
2843

2844
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&                               \
2845
    defined(_LIBUNWIND_TARGET_LOONGARCH)
2846
template <typename A, typename R>
2847
bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_loongarch &) {
2848
  const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2849
  // The PC might contain an invalid address if the unwind info is bad, so
2850
  // directly accessing it could cause a SIGSEGV.
2851
  if (!isReadableAddr(pc))
2852
    return false;
2853
  const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2854
  // Look for the two instructions used in the sigreturn trampoline
2855
  // __vdso_rt_sigreturn:
2856
  //
2857
  // 0x03822c0b li a7,0x8b
2858
  // 0x002b0000 syscall 0
2859
  if (instructions[0] != 0x03822c0b || instructions[1] != 0x002b0000)
2860
    return false;
2861

2862
  _info = {};
2863
  _info.start_ip = pc;
2864
  _info.end_ip = pc + 4;
2865
  _isSigReturn = true;
2866
  return true;
2867
}
2868

2869
template <typename A, typename R>
2870
int UnwindCursor<A, R>::stepThroughSigReturn(Registers_loongarch &) {
2871
  // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2872
  //  - 128-byte siginfo struct
2873
  //  - ucontext_t struct:
2874
  //     - 8-byte long (__uc_flags)
2875
  //     - 8-byte pointer (*uc_link)
2876
  //     - 24-byte uc_stack
2877
  //     - 8-byte uc_sigmask
2878
  //     - 120-byte of padding to allow sigset_t to be expanded in the future
2879
  //     - 8 bytes of padding because sigcontext has 16-byte alignment
2880
  //     - struct sigcontext uc_mcontext
2881
  // [1]
2882
  // https://github.com/torvalds/linux/blob/master/arch/loongarch/kernel/signal.c
2883
  const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2884

2885
  const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2886
  _registers.setIP(_addressSpace.get64(sigctx));
2887
  for (int i = UNW_LOONGARCH_R1; i <= UNW_LOONGARCH_R31; ++i) {
2888
    // skip R0
2889
    uint64_t value =
2890
        _addressSpace.get64(sigctx + static_cast<pint_t>((i + 1) * 8));
2891
    _registers.setRegister(i, value);
2892
  }
2893
  _isSignalFrame = true;
2894
  return UNW_STEP_SUCCESS;
2895
}
2896
#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2897
       // defined(_LIBUNWIND_TARGET_LOONGARCH)
2898

2899
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&                               \
2900
    defined(_LIBUNWIND_TARGET_RISCV)
2901
template <typename A, typename R>
2902
bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_riscv &) {
2903
  const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2904
  // The PC might contain an invalid address if the unwind info is bad, so
2905
  // directly accessing it could cause a SIGSEGV.
2906
  if (!isReadableAddr(pc))
2907
    return false;
2908
  const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2909
  // Look for the two instructions used in the sigreturn trampoline
2910
  // __vdso_rt_sigreturn:
2911
  //
2912
  // 0x08b00893 li a7,0x8b
2913
  // 0x00000073 ecall
2914
  if (instructions[0] != 0x08b00893 || instructions[1] != 0x00000073)
2915
    return false;
2916

2917
  _info = {};
2918
  _info.start_ip = pc;
2919
  _info.end_ip = pc + 4;
2920
  _isSigReturn = true;
2921
  return true;
2922
}
2923

2924
template <typename A, typename R>
2925
int UnwindCursor<A, R>::stepThroughSigReturn(Registers_riscv &) {
2926
  // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2927
  //  - 128-byte siginfo struct
2928
  //  - ucontext_t struct:
2929
  //     - 8-byte long (__uc_flags)
2930
  //     - 8-byte pointer (*uc_link)
2931
  //     - 24-byte uc_stack
2932
  //     - 8-byte uc_sigmask
2933
  //     - 120-byte of padding to allow sigset_t to be expanded in the future
2934
  //     - 8 bytes of padding because sigcontext has 16-byte alignment
2935
  //     - struct sigcontext uc_mcontext
2936
  // [1]
2937
  // https://github.com/torvalds/linux/blob/master/arch/riscv/kernel/signal.c
2938
  const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2939

2940
  const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2941
  _registers.setIP(_addressSpace.get64(sigctx));
2942
  for (int i = UNW_RISCV_X1; i <= UNW_RISCV_X31; ++i) {
2943
    uint64_t value = _addressSpace.get64(sigctx + static_cast<pint_t>(i * 8));
2944
    _registers.setRegister(i, value);
2945
  }
2946
  _isSignalFrame = true;
2947
  return UNW_STEP_SUCCESS;
2948
}
2949
#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2950
       // defined(_LIBUNWIND_TARGET_RISCV)
2951

2952
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&                               \
2953
    defined(_LIBUNWIND_TARGET_S390X)
2954
template <typename A, typename R>
2955
bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
2956
  // Look for the sigreturn trampoline. The trampoline's body is a
2957
  // specific instruction (see below). Typically the trampoline comes from the
2958
  // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its
2959
  // own restorer function, though, or user-mode QEMU might write a trampoline
2960
  // onto the stack.
2961
  const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2962
  // The PC might contain an invalid address if the unwind info is bad, so
2963
  // directly accessing it could cause a SIGSEGV.
2964
  if (!isReadableAddr(pc))
2965
    return false;
2966
  const auto inst = *reinterpret_cast<const uint16_t *>(pc);
2967
  if (inst == 0x0a77 || inst == 0x0aad) {
2968
    _info = {};
2969
    _info.start_ip = pc;
2970
    _info.end_ip = pc + 2;
2971
    _isSigReturn = true;
2972
    return true;
2973
  }
2974
  return false;
2975
}
2976

2977
template <typename A, typename R>
2978
int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
2979
  // Determine current SP.
2980
  const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP));
2981
  // According to the s390x ABI, the CFA is at (incoming) SP + 160.
2982
  const pint_t cfa = sp + 160;
2983

2984
  // Determine current PC and instruction there (this must be either
2985
  // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn").
2986
  const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2987
  const uint16_t inst = _addressSpace.get16(pc);
2988

2989
  // Find the addresses of the signo and sigcontext in the frame.
2990
  pint_t pSigctx = 0;
2991
  pint_t pSigno = 0;
2992

2993
  // "svc __NR_sigreturn" uses a non-RT signal trampoline frame.
2994
  if (inst == 0x0a77) {
2995
    // Layout of a non-RT signal trampoline frame, starting at the CFA:
2996
    //  - 8-byte signal mask
2997
    //  - 8-byte pointer to sigcontext, followed by signo
2998
    //  - 4-byte signo
2999
    pSigctx = _addressSpace.get64(cfa + 8);
3000
    pSigno = pSigctx + 344;
3001
  }
3002

3003
  // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame.
3004
  if (inst == 0x0aad) {
3005
    // Layout of a RT signal trampoline frame, starting at the CFA:
3006
    //  - 8-byte retcode (+ alignment)
3007
    //  - 128-byte siginfo struct (starts with signo)
3008
    //  - ucontext struct:
3009
    //     - 8-byte long (uc_flags)
3010
    //     - 8-byte pointer (uc_link)
3011
    //     - 24-byte stack_t
3012
    //     - 8 bytes of padding because sigcontext has 16-byte alignment
3013
    //     - sigcontext/mcontext_t
3014
    pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8;
3015
    pSigno = cfa + 8;
3016
  }
3017

3018
  assert(pSigctx != 0);
3019
  assert(pSigno != 0);
3020

3021
  // Offsets from sigcontext to each register.
3022
  const pint_t kOffsetPc = 8;
3023
  const pint_t kOffsetGprs = 16;
3024
  const pint_t kOffsetFprs = 216;
3025

3026
  // Restore all registers.
3027
  for (int i = 0; i < 16; ++i) {
3028
    uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs +
3029
                                         static_cast<pint_t>(i * 8));
3030
    _registers.setRegister(UNW_S390X_R0 + i, value);
3031
  }
3032
  for (int i = 0; i < 16; ++i) {
3033
    static const int fpr[16] = {
3034
      UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3,
3035
      UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7,
3036
      UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11,
3037
      UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15
3038
    };
3039
    double value = _addressSpace.getDouble(pSigctx + kOffsetFprs +
3040
                                           static_cast<pint_t>(i * 8));
3041
    _registers.setFloatRegister(fpr[i], value);
3042
  }
3043
  _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc));
3044

3045
  // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
3046
  // after the faulting instruction rather than before it.
3047
  // Do not set _isSignalFrame in that case.
3048
  uint32_t signo = _addressSpace.get32(pSigno);
3049
  _isSignalFrame = (signo != 4 && signo != 5 && signo != 8);
3050

3051
  return UNW_STEP_SUCCESS;
3052
}
3053
#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
3054
       // defined(_LIBUNWIND_TARGET_S390X)
3055

3056
#if defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3057
template <typename A, typename R>
3058
bool UnwindCursor<A, R>::setInfoForSigReturn() {
3059
  Dl_info dlinfo;
3060
  const auto isSignalHandler = [&](pint_t addr) {
3061
    if (!dladdr(reinterpret_cast<void *>(addr), &dlinfo))
3062
      return false;
3063
    if (strcmp(dlinfo.dli_fname, "commpage"))
3064
      return false;
3065
    if (dlinfo.dli_sname == NULL ||
3066
        strcmp(dlinfo.dli_sname, "commpage_signal_handler"))
3067
      return false;
3068
    return true;
3069
  };
3070

3071
  pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
3072
  if (!isSignalHandler(pc))
3073
    return false;
3074

3075
  pint_t start = reinterpret_cast<pint_t>(dlinfo.dli_saddr);
3076

3077
  static size_t signalHandlerSize = 0;
3078
  if (signalHandlerSize == 0) {
3079
    size_t boundLow = 0;
3080
    size_t boundHigh = static_cast<size_t>(-1);
3081

3082
    area_info areaInfo;
3083
    if (get_area_info(area_for(dlinfo.dli_saddr), &areaInfo) == B_OK)
3084
      boundHigh = areaInfo.size;
3085

3086
    while (boundLow < boundHigh) {
3087
      size_t boundMid = boundLow + ((boundHigh - boundLow) / 2);
3088
      pint_t test = start + boundMid;
3089
      if (test >= start && isSignalHandler(test))
3090
        boundLow = boundMid + 1;
3091
      else
3092
        boundHigh = boundMid;
3093
    }
3094

3095
    signalHandlerSize = boundHigh;
3096
  }
3097

3098
  _info = {};
3099
  _info.start_ip = start;
3100
  _info.end_ip = start + signalHandlerSize;
3101
  _isSigReturn = true;
3102

3103
  return true;
3104
}
3105

3106
template <typename A, typename R>
3107
int UnwindCursor<A, R>::stepThroughSigReturn() {
3108
  _isSignalFrame = true;
3109

3110
#if defined(_LIBUNWIND_TARGET_X86_64)
3111
  // Layout of the stack before function call:
3112
  // - signal_frame_data
3113
  //   + siginfo_t    (public struct, fairly stable)
3114
  //   + ucontext_t   (public struct, fairly stable)
3115
  //     - mcontext_t -> Offset 0x70, this is what we want.
3116
  // - frame->ip (8 bytes)
3117
  // - frame->bp (8 bytes). Not written by the kernel,
3118
  //   but the signal handler has a "push %rbp" instruction.
3119
  pint_t bp = this->getReg(UNW_X86_64_RBP);
3120
  vregs *regs = (vregs *)(bp + 0x70);
3121

3122
  _registers.setRegister(UNW_REG_IP, regs->rip);
3123
  _registers.setRegister(UNW_REG_SP, regs->rsp);
3124
  _registers.setRegister(UNW_X86_64_RAX, regs->rax);
3125
  _registers.setRegister(UNW_X86_64_RDX, regs->rdx);
3126
  _registers.setRegister(UNW_X86_64_RCX, regs->rcx);
3127
  _registers.setRegister(UNW_X86_64_RBX, regs->rbx);
3128
  _registers.setRegister(UNW_X86_64_RSI, regs->rsi);
3129
  _registers.setRegister(UNW_X86_64_RDI, regs->rdi);
3130
  _registers.setRegister(UNW_X86_64_RBP, regs->rbp);
3131
  _registers.setRegister(UNW_X86_64_R8, regs->r8);
3132
  _registers.setRegister(UNW_X86_64_R9, regs->r9);
3133
  _registers.setRegister(UNW_X86_64_R10, regs->r10);
3134
  _registers.setRegister(UNW_X86_64_R11, regs->r11);
3135
  _registers.setRegister(UNW_X86_64_R12, regs->r12);
3136
  _registers.setRegister(UNW_X86_64_R13, regs->r13);
3137
  _registers.setRegister(UNW_X86_64_R14, regs->r14);
3138
  _registers.setRegister(UNW_X86_64_R15, regs->r15);
3139
  // TODO: XMM
3140
#endif // defined(_LIBUNWIND_TARGET_X86_64)
3141

3142
  return UNW_STEP_SUCCESS;
3143
}
3144
#endif // defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3145

3146
template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
3147
  (void)stage2;
3148
  // Bottom of stack is defined is when unwind info cannot be found.
3149
  if (_unwindInfoMissing)
3150
    return UNW_STEP_END;
3151

3152
  // Use unwinding info to modify register set as if function returned.
3153
  int result;
3154
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) ||                               \
3155
    defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3156
  if (_isSigReturn) {
3157
    result = this->stepThroughSigReturn();
3158
  } else
3159
#endif
3160
  {
3161
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
3162
    result = this->stepWithCompactEncoding(stage2);
3163
#elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
3164
    result = this->stepWithSEHData();
3165
#elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
3166
    result = this->stepWithTBTableData();
3167
#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
3168
    result = this->stepWithDwarfFDE(stage2);
3169
#elif defined(_LIBUNWIND_ARM_EHABI)
3170
    result = this->stepWithEHABI();
3171
#else
3172
  #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
3173
              _LIBUNWIND_SUPPORT_SEH_UNWIND or \
3174
              _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
3175
              _LIBUNWIND_ARM_EHABI
3176
#endif
3177
  }
3178

3179
  // update info based on new PC
3180
  if (result == UNW_STEP_SUCCESS) {
3181
    this->setInfoBasedOnIPRegister(true);
3182
    if (_unwindInfoMissing)
3183
      return UNW_STEP_END;
3184
  }
3185

3186
  return result;
3187
}
3188

3189
template <typename A, typename R>
3190
void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
3191
  if (_unwindInfoMissing)
3192
    memset(info, 0, sizeof(*info));
3193
  else
3194
    *info = _info;
3195
}
3196

3197
template <typename A, typename R>
3198
bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
3199
                                                           unw_word_t *offset) {
3200
  return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
3201
                                         buf, bufLen, offset);
3202
}
3203

3204
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
3205
template <typename A, typename R>
3206
bool UnwindCursor<A, R>::isReadableAddr(const pint_t addr) const {
3207
  // We use SYS_rt_sigprocmask, inspired by Abseil's AddressIsReadable.
3208

3209
  const auto sigsetAddr = reinterpret_cast<sigset_t *>(addr);
3210
  // We have to check that addr is nullptr because sigprocmask allows that
3211
  // as an argument without failure.
3212
  if (!sigsetAddr)
3213
    return false;
3214
  const auto saveErrno = errno;
3215
  // We MUST use a raw syscall here, as wrappers may try to access
3216
  // sigsetAddr which may cause a SIGSEGV. A raw syscall however is
3217
  // safe. Additionally, we need to pass the kernel_sigset_size, which is
3218
  // different from libc sizeof(sigset_t). For the majority of architectures,
3219
  // it's 64 bits (_NSIG), and libc NSIG is _NSIG + 1.
3220
  const auto kernelSigsetSize = NSIG / 8;
3221
  [[maybe_unused]] const int Result = syscall(
3222
      SYS_rt_sigprocmask, /*how=*/~0, sigsetAddr, nullptr, kernelSigsetSize);
3223
  // Because our "how" is invalid, this syscall should always fail, and our
3224
  // errno should always be EINVAL or an EFAULT. This relies on the Linux
3225
  // kernel to check copy_from_user before checking if the "how" argument is
3226
  // invalid.
3227
  assert(Result == -1);
3228
  assert(errno == EFAULT || errno == EINVAL);
3229
  const auto readable = errno != EFAULT;
3230
  errno = saveErrno;
3231
  return readable;
3232
}
3233
#endif
3234

3235
#if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
3236
extern "C" void *__libunwind_shstk_get_registers(unw_cursor_t *cursor) {
3237
  AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
3238
  return co->get_registers();
3239
}
3240
#endif
3241
} // namespace libunwind
3242

3243
#endif // __UNWINDCURSOR_HPP__
3244

3245
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