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1//===-- GDBRemoteRegisterContext.cpp --------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "GDBRemoteRegisterContext.h"10 11#include "ProcessGDBRemote.h"12#include "ProcessGDBRemoteLog.h"13#include "ThreadGDBRemote.h"14#include "Utility/ARM_DWARF_Registers.h"15#include "Utility/ARM_ehframe_Registers.h"16#include "lldb/Core/Architecture.h"17#include "lldb/Target/ExecutionContext.h"18#include "lldb/Target/Target.h"19#include "lldb/Utility/DataBufferHeap.h"20#include "lldb/Utility/DataExtractor.h"21#include "lldb/Utility/RegisterValue.h"22#include "lldb/Utility/Scalar.h"23#include "lldb/Utility/StreamString.h"24#include "lldb/Utility/StringExtractorGDBRemote.h"25 26#include <memory>27 28using namespace lldb;29using namespace lldb_private;30using namespace lldb_private::process_gdb_remote;31 32// GDBRemoteRegisterContext constructor33GDBRemoteRegisterContext::GDBRemoteRegisterContext(34    ThreadGDBRemote &thread, uint32_t concrete_frame_idx,35    GDBRemoteDynamicRegisterInfoSP reg_info_sp, bool read_all_at_once,36    bool write_all_at_once)37    : RegisterContext(thread, concrete_frame_idx),38      m_reg_info_sp(std::move(reg_info_sp)), m_reg_valid(), m_reg_data(),39      m_read_all_at_once(read_all_at_once),40      m_write_all_at_once(write_all_at_once), m_gpacket_cached(false) {41  // Resize our vector of bools to contain one bool for every register. We will42  // use these boolean values to know when a register value is valid in43  // m_reg_data.44  m_reg_valid.resize(m_reg_info_sp->GetNumRegisters());45 46  // Make a heap based buffer that is big enough to store all registers47  DataBufferSP reg_data_sp(48      new DataBufferHeap(m_reg_info_sp->GetRegisterDataByteSize(), 0));49  m_reg_data.SetData(reg_data_sp);50  m_reg_data.SetByteOrder(thread.GetProcess()->GetByteOrder());51}52 53// Destructor54GDBRemoteRegisterContext::~GDBRemoteRegisterContext() = default;55 56void GDBRemoteRegisterContext::InvalidateAllRegisters() {57  SetAllRegisterValid(false);58}59 60void GDBRemoteRegisterContext::SetAllRegisterValid(bool b) {61  m_gpacket_cached = b;62  std::vector<bool>::iterator pos, end = m_reg_valid.end();63  for (pos = m_reg_valid.begin(); pos != end; ++pos)64    *pos = b;65}66 67size_t GDBRemoteRegisterContext::GetRegisterCount() {68  return m_reg_info_sp->GetNumRegisters();69}70 71const RegisterInfo *72GDBRemoteRegisterContext::GetRegisterInfoAtIndex(size_t reg) {73  return m_reg_info_sp->GetRegisterInfoAtIndex(reg);74}75 76size_t GDBRemoteRegisterContext::GetRegisterSetCount() {77  return m_reg_info_sp->GetNumRegisterSets();78}79 80const RegisterSet *GDBRemoteRegisterContext::GetRegisterSet(size_t reg_set) {81  return m_reg_info_sp->GetRegisterSet(reg_set);82}83 84bool GDBRemoteRegisterContext::ReadRegister(const RegisterInfo *reg_info,85                                            RegisterValue &value) {86  // Read the register87  if (ReadRegisterBytes(reg_info)) {88    const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];89    if (m_reg_valid[reg] == false)90      return false;91    if (reg_info->value_regs &&92        reg_info->value_regs[0] != LLDB_INVALID_REGNUM &&93        reg_info->value_regs[1] != LLDB_INVALID_REGNUM) {94      std::vector<char> combined_data;95      uint32_t offset = 0;96      for (int i = 0; reg_info->value_regs[i] != LLDB_INVALID_REGNUM; i++) {97        const RegisterInfo *parent_reg = GetRegisterInfo(98            eRegisterKindLLDB, reg_info->value_regs[i]);99        if (!parent_reg)100          return false;101        combined_data.resize(offset + parent_reg->byte_size);102        if (m_reg_data.CopyData(parent_reg->byte_offset, parent_reg->byte_size,103                                combined_data.data() + offset) !=104            parent_reg->byte_size)105          return false;106        offset += parent_reg->byte_size;107      }108 109      Status error;110      return value.SetFromMemoryData(111                 *reg_info, combined_data.data(), combined_data.size(),112                 m_reg_data.GetByteOrder(), error) == combined_data.size();113    } else {114      const bool partial_data_ok = false;115      Status error(value.SetValueFromData(116          *reg_info, m_reg_data, reg_info->byte_offset, partial_data_ok));117      return error.Success();118    }119  }120  return false;121}122 123bool GDBRemoteRegisterContext::PrivateSetRegisterValue(124    uint32_t reg, llvm::ArrayRef<uint8_t> data) {125  const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg);126  if (reg_info == nullptr)127    return false;128 129  // Invalidate if needed130  InvalidateIfNeeded(false);131 132  const size_t reg_byte_size = reg_info->byte_size;133  memcpy(const_cast<uint8_t *>(134             m_reg_data.PeekData(reg_info->byte_offset, reg_byte_size)),135         data.data(), std::min(data.size(), reg_byte_size));136  bool success = data.size() >= reg_byte_size;137  if (success) {138    SetRegisterIsValid(reg, true);139  } else if (data.size() > 0) {140    // Only set register is valid to false if we copied some bytes, else leave141    // it as it was.142    SetRegisterIsValid(reg, false);143  }144  return success;145}146 147bool GDBRemoteRegisterContext::PrivateSetRegisterValue(uint32_t reg,148                                                       uint64_t new_reg_val) {149  const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg);150  if (reg_info == nullptr)151    return false;152 153  // Early in process startup, we can get a thread that has an invalid byte154  // order because the process hasn't been completely set up yet (see the ctor155  // where the byte order is setfrom the process).  If that's the case, we156  // can't set the value here.157  if (m_reg_data.GetByteOrder() == eByteOrderInvalid) {158    return false;159  }160 161  // Invalidate if needed162  InvalidateIfNeeded(false);163 164  DataBufferSP buffer_sp(new DataBufferHeap(&new_reg_val, sizeof(new_reg_val)));165  DataExtractor data(buffer_sp, endian::InlHostByteOrder(), sizeof(void *));166 167  // If our register context and our register info disagree, which should never168  // happen, don't overwrite past the end of the buffer.169  if (m_reg_data.GetByteSize() < reg_info->byte_offset + reg_info->byte_size)170    return false;171 172  // Grab a pointer to where we are going to put this register173  uint8_t *dst = const_cast<uint8_t *>(174      m_reg_data.PeekData(reg_info->byte_offset, reg_info->byte_size));175 176  if (dst == nullptr)177    return false;178 179  if (data.CopyByteOrderedData(0,                          // src offset180                               reg_info->byte_size,        // src length181                               dst,                        // dst182                               reg_info->byte_size,        // dst length183                               m_reg_data.GetByteOrder())) // dst byte order184  {185    SetRegisterIsValid(reg, true);186    return true;187  }188  return false;189}190 191// Helper function for GDBRemoteRegisterContext::ReadRegisterBytes().192bool GDBRemoteRegisterContext::GetPrimordialRegister(193    const RegisterInfo *reg_info, GDBRemoteCommunicationClient &gdb_comm) {194  const uint32_t lldb_reg = reg_info->kinds[eRegisterKindLLDB];195  const uint32_t remote_reg = reg_info->kinds[eRegisterKindProcessPlugin];196 197  if (DataBufferSP buffer_sp =198          gdb_comm.ReadRegister(m_thread.GetProtocolID(), remote_reg))199    return PrivateSetRegisterValue(200        lldb_reg, llvm::ArrayRef<uint8_t>(buffer_sp->GetBytes(),201                                          buffer_sp->GetByteSize()));202  return false;203}204 205bool GDBRemoteRegisterContext::ReadRegisterBytes(const RegisterInfo *reg_info) {206  ExecutionContext exe_ctx(CalculateThread());207 208  Process *process = exe_ctx.GetProcessPtr();209  Thread *thread = exe_ctx.GetThreadPtr();210  if (process == nullptr || thread == nullptr)211    return false;212 213  GDBRemoteCommunicationClient &gdb_comm(214      ((ProcessGDBRemote *)process)->GetGDBRemote());215 216  InvalidateIfNeeded(false);217 218  const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];219 220  if (!GetRegisterIsValid(reg)) {221    if (m_read_all_at_once && !m_gpacket_cached) {222      if (DataBufferSP buffer_sp =223              gdb_comm.ReadAllRegisters(m_thread.GetProtocolID())) {224        memcpy(const_cast<uint8_t *>(m_reg_data.GetDataStart()),225               buffer_sp->GetBytes(),226               std::min(buffer_sp->GetByteSize(), m_reg_data.GetByteSize()));227        if (buffer_sp->GetByteSize() >= m_reg_data.GetByteSize()) {228          SetAllRegisterValid(true);229          return true;230        } else if (buffer_sp->GetByteSize() > 0) {231          for (auto x : llvm::enumerate(232                   m_reg_info_sp->registers<233                       DynamicRegisterInfo::reg_collection_const_range>())) {234            const struct RegisterInfo &reginfo = x.value();235            m_reg_valid[x.index()] =236                (reginfo.byte_offset + reginfo.byte_size <=237                 buffer_sp->GetByteSize());238          }239 240          m_gpacket_cached = true;241          if (GetRegisterIsValid(reg))242            return true;243        } else {244          Log *log(GetLog(GDBRLog::Thread | GDBRLog::Packets));245          LLDB_LOGF(246              log,247              "error: GDBRemoteRegisterContext::ReadRegisterBytes tried "248              "to read the "249              "entire register context at once, expected at least %" PRId64250              " bytes "251              "but only got %" PRId64 " bytes.",252              m_reg_data.GetByteSize(), buffer_sp->GetByteSize());253          return false;254        }255      }256    }257    if (reg_info->value_regs) {258      // Process this composite register request by delegating to the259      // constituent primordial registers.260 261      // Index of the primordial register.262      bool success = true;263      for (uint32_t idx = 0; success; ++idx) {264        const uint32_t prim_reg = reg_info->value_regs[idx];265        if (prim_reg == LLDB_INVALID_REGNUM)266          break;267        // We have a valid primordial register as our constituent. Grab the268        // corresponding register info.269        const RegisterInfo *prim_reg_info =270            GetRegisterInfo(eRegisterKindLLDB, prim_reg);271        if (prim_reg_info == nullptr)272          success = false;273        else {274          // Read the containing register if it hasn't already been read275          if (!GetRegisterIsValid(prim_reg))276            success = GetPrimordialRegister(prim_reg_info, gdb_comm);277        }278      }279 280      if (success) {281        // If we reach this point, all primordial register requests have282        // succeeded. Validate this composite register.283        SetRegisterIsValid(reg_info, true);284      }285    } else {286      // Get each register individually287      GetPrimordialRegister(reg_info, gdb_comm);288    }289 290    // Make sure we got a valid register value after reading it291    if (!GetRegisterIsValid(reg))292      return false;293  }294 295  return true;296}297 298bool GDBRemoteRegisterContext::WriteRegister(const RegisterInfo *reg_info,299                                             const RegisterValue &value) {300  DataExtractor data;301  if (value.GetData(data)) {302    if (reg_info->value_regs &&303        reg_info->value_regs[0] != LLDB_INVALID_REGNUM &&304        reg_info->value_regs[1] != LLDB_INVALID_REGNUM) {305      uint32_t combined_size = 0;306      for (int i = 0; reg_info->value_regs[i] != LLDB_INVALID_REGNUM; i++) {307        const RegisterInfo *parent_reg = GetRegisterInfo(308            eRegisterKindLLDB, reg_info->value_regs[i]);309        if (!parent_reg)310          return false;311        combined_size += parent_reg->byte_size;312      }313 314      if (data.GetByteSize() < combined_size)315        return false;316 317      uint32_t offset = 0;318      for (int i = 0; reg_info->value_regs[i] != LLDB_INVALID_REGNUM; i++) {319        const RegisterInfo *parent_reg = GetRegisterInfo(320            eRegisterKindLLDB, reg_info->value_regs[i]);321        assert(parent_reg);322 323        DataExtractor parent_data{data, offset, parent_reg->byte_size};324        if (!WriteRegisterBytes(parent_reg, parent_data, 0))325          return false;326        offset += parent_reg->byte_size;327      }328      assert(offset == combined_size);329      return true;330    } else331      return WriteRegisterBytes(reg_info, data, 0);332  }333  return false;334}335 336// Helper function for GDBRemoteRegisterContext::WriteRegisterBytes().337bool GDBRemoteRegisterContext::SetPrimordialRegister(338    const RegisterInfo *reg_info, GDBRemoteCommunicationClient &gdb_comm) {339  StreamString packet;340  StringExtractorGDBRemote response;341  const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];342  // Invalidate just this register343  SetRegisterIsValid(reg, false);344 345  return gdb_comm.WriteRegister(346      m_thread.GetProtocolID(), reg_info->kinds[eRegisterKindProcessPlugin],347      {m_reg_data.PeekData(reg_info->byte_offset, reg_info->byte_size),348       reg_info->byte_size});349}350 351bool GDBRemoteRegisterContext::WriteRegisterBytes(const RegisterInfo *reg_info,352                                                  DataExtractor &data,353                                                  uint32_t data_offset) {354  ExecutionContext exe_ctx(CalculateThread());355 356  Process *process = exe_ctx.GetProcessPtr();357  Thread *thread = exe_ctx.GetThreadPtr();358  if (process == nullptr || thread == nullptr)359    return false;360 361  GDBRemoteCommunicationClient &gdb_comm(362      ((ProcessGDBRemote *)process)->GetGDBRemote());363 364  assert(m_reg_data.GetByteSize() >=365         reg_info->byte_offset + reg_info->byte_size);366 367  // If our register context and our register info disagree, which should never368  // happen, don't overwrite past the end of the buffer.369  if (m_reg_data.GetByteSize() < reg_info->byte_offset + reg_info->byte_size)370    return false;371 372  // Grab a pointer to where we are going to put this register373  uint8_t *dst = const_cast<uint8_t *>(374      m_reg_data.PeekData(reg_info->byte_offset, reg_info->byte_size));375 376  if (dst == nullptr)377    return false;378 379  const bool should_reconfigure_registers =380      RegisterWriteCausesReconfigure(reg_info->name);381 382  if (data.CopyByteOrderedData(data_offset,                // src offset383                               reg_info->byte_size,        // src length384                               dst,                        // dst385                               reg_info->byte_size,        // dst length386                               m_reg_data.GetByteOrder())) // dst byte order387  {388    GDBRemoteClientBase::Lock lock(gdb_comm);389    if (lock) {390      if (m_write_all_at_once) {391        // Invalidate all register values392        InvalidateIfNeeded(true);393 394        // Set all registers in one packet395        if (gdb_comm.WriteAllRegisters(396                m_thread.GetProtocolID(),397                {m_reg_data.GetDataStart(), size_t(m_reg_data.GetByteSize())}))398 399        {400          if (should_reconfigure_registers)401            ReconfigureRegisterInfo();402 403          InvalidateAllRegisters();404 405          return true;406        }407      } else {408        bool success = true;409 410        if (reg_info->value_regs) {411          // This register is part of another register. In this case we read412          // the actual register data for any "value_regs", and once all that413          // data is read, we will have enough data in our register context414          // bytes for the value of this register415 416          // Invalidate this composite register first.417 418          for (uint32_t idx = 0; success; ++idx) {419            const uint32_t reg = reg_info->value_regs[idx];420            if (reg == LLDB_INVALID_REGNUM)421              break;422            // We have a valid primordial register as our constituent. Grab the423            // corresponding register info.424            const RegisterInfo *value_reg_info =425                GetRegisterInfo(eRegisterKindLLDB, reg);426            if (value_reg_info == nullptr)427              success = false;428            else429              success = SetPrimordialRegister(value_reg_info, gdb_comm);430          }431        } else {432          // This is an actual register, write it433          success = SetPrimordialRegister(reg_info, gdb_comm);434        }435 436        // Check if writing this register will invalidate any other register437        // values? If so, invalidate them438        if (reg_info->invalidate_regs) {439          for (uint32_t idx = 0, reg = reg_info->invalidate_regs[0];440               reg != LLDB_INVALID_REGNUM;441               reg = reg_info->invalidate_regs[++idx])442            SetRegisterIsValid(ConvertRegisterKindToRegisterNumber(443                                   eRegisterKindLLDB, reg),444                               false);445        }446 447        if (success && should_reconfigure_registers &&448            ReconfigureRegisterInfo())449          InvalidateAllRegisters();450 451        return success;452      }453    } else {454      Log *log(GetLog(GDBRLog::Thread | GDBRLog::Packets));455      if (log) {456        if (log->GetVerbose()) {457          StreamString strm;458          process->DumpPluginHistory(strm);459          LLDB_LOGF(log,460                    "error: failed to get packet sequence mutex, not sending "461                    "write register for \"%s\":\n%s",462                    reg_info->name, strm.GetData());463        } else464          LLDB_LOGF(log,465                    "error: failed to get packet sequence mutex, not sending "466                    "write register for \"%s\"",467                    reg_info->name);468      }469    }470  }471  return false;472}473 474bool GDBRemoteRegisterContext::ReadAllRegisterValues(475    RegisterCheckpoint &reg_checkpoint) {476  ExecutionContext exe_ctx(CalculateThread());477 478  Process *process = exe_ctx.GetProcessPtr();479  Thread *thread = exe_ctx.GetThreadPtr();480  if (process == nullptr || thread == nullptr)481    return false;482 483  GDBRemoteCommunicationClient &gdb_comm(484      ((ProcessGDBRemote *)process)->GetGDBRemote());485 486  uint32_t save_id = 0;487  if (gdb_comm.SaveRegisterState(thread->GetProtocolID(), save_id)) {488    reg_checkpoint.SetID(save_id);489    reg_checkpoint.GetData().reset();490    return true;491  } else {492    reg_checkpoint.SetID(0); // Invalid save ID is zero493    return ReadAllRegisterValues(reg_checkpoint.GetData());494  }495}496 497bool GDBRemoteRegisterContext::WriteAllRegisterValues(498    const RegisterCheckpoint &reg_checkpoint) {499  uint32_t save_id = reg_checkpoint.GetID();500  if (save_id != 0) {501    ExecutionContext exe_ctx(CalculateThread());502 503    Process *process = exe_ctx.GetProcessPtr();504    Thread *thread = exe_ctx.GetThreadPtr();505    if (process == nullptr || thread == nullptr)506      return false;507 508    GDBRemoteCommunicationClient &gdb_comm(509        ((ProcessGDBRemote *)process)->GetGDBRemote());510 511    return gdb_comm.RestoreRegisterState(m_thread.GetProtocolID(), save_id);512  } else {513    return WriteAllRegisterValues(reg_checkpoint.GetData());514  }515}516 517bool GDBRemoteRegisterContext::ReadAllRegisterValues(518    lldb::WritableDataBufferSP &data_sp) {519  ExecutionContext exe_ctx(CalculateThread());520 521  Process *process = exe_ctx.GetProcessPtr();522  Thread *thread = exe_ctx.GetThreadPtr();523  if (process == nullptr || thread == nullptr)524    return false;525 526  GDBRemoteCommunicationClient &gdb_comm(527      ((ProcessGDBRemote *)process)->GetGDBRemote());528 529  const bool use_g_packet =530      !gdb_comm.AvoidGPackets((ProcessGDBRemote *)process);531 532  GDBRemoteClientBase::Lock lock(gdb_comm);533  if (lock) {534    if (gdb_comm.SyncThreadState(m_thread.GetProtocolID()))535      InvalidateAllRegisters();536 537    if (use_g_packet) {538      if (DataBufferSP data_buffer =539              gdb_comm.ReadAllRegisters(m_thread.GetProtocolID())) {540        data_sp = std::make_shared<DataBufferHeap>(*data_buffer);541        return true;542      }543    }544 545    // We're going to read each register546    // individually and store them as binary data in a buffer.547    const RegisterInfo *reg_info;548 549    for (uint32_t i = 0; (reg_info = GetRegisterInfoAtIndex(i)) != nullptr;550         i++) {551      if (reg_info552              ->value_regs) // skip registers that are slices of real registers553        continue;554      ReadRegisterBytes(reg_info);555      // ReadRegisterBytes saves the contents of the register in to the556      // m_reg_data buffer557    }558    data_sp = std::make_shared<DataBufferHeap>(559        m_reg_data.GetDataStart(), m_reg_info_sp->GetRegisterDataByteSize());560    return true;561  } else {562 563    Log *log(GetLog(GDBRLog::Thread | GDBRLog::Packets));564    if (log) {565      if (log->GetVerbose()) {566        StreamString strm;567        process->DumpPluginHistory(strm);568        LLDB_LOGF(log,569                  "error: failed to get packet sequence mutex, not sending "570                  "read all registers:\n%s",571                  strm.GetData());572      } else573        LLDB_LOGF(log,574                  "error: failed to get packet sequence mutex, not sending "575                  "read all registers");576    }577  }578 579  data_sp.reset();580  return false;581}582 583bool GDBRemoteRegisterContext::WriteAllRegisterValues(584    const lldb::DataBufferSP &data_sp) {585  if (!data_sp || data_sp->GetBytes() == nullptr || data_sp->GetByteSize() == 0)586    return false;587 588  ExecutionContext exe_ctx(CalculateThread());589 590  Process *process = exe_ctx.GetProcessPtr();591  Thread *thread = exe_ctx.GetThreadPtr();592  if (process == nullptr || thread == nullptr)593    return false;594 595  GDBRemoteCommunicationClient &gdb_comm(596      ((ProcessGDBRemote *)process)->GetGDBRemote());597 598  const bool use_g_packet =599      !gdb_comm.AvoidGPackets((ProcessGDBRemote *)process);600 601  GDBRemoteClientBase::Lock lock(gdb_comm);602  if (lock) {603    // The data_sp contains the G response packet.604    if (use_g_packet) {605      if (gdb_comm.WriteAllRegisters(606              m_thread.GetProtocolID(),607              {data_sp->GetBytes(), size_t(data_sp->GetByteSize())}))608        return true;609 610      uint32_t num_restored = 0;611      // We need to manually go through all of the registers and restore them612      // manually613      DataExtractor restore_data(data_sp, m_reg_data.GetByteOrder(),614                                 m_reg_data.GetAddressByteSize());615 616      const RegisterInfo *reg_info;617 618      // The g packet contents may either include the slice registers619      // (registers defined in terms of other registers, e.g. eax is a subset620      // of rax) or not.  The slice registers should NOT be in the g packet,621      // but some implementations may incorrectly include them.622      //623      // If the slice registers are included in the packet, we must step over624      // the slice registers when parsing the packet -- relying on the625      // RegisterInfo byte_offset field would be incorrect. If the slice626      // registers are not included, then using the byte_offset values into the627      // data buffer is the best way to find individual register values.628 629      uint64_t size_including_slice_registers = 0;630      uint64_t size_not_including_slice_registers = 0;631      uint64_t size_by_highest_offset = 0;632 633      for (uint32_t reg_idx = 0;634           (reg_info = GetRegisterInfoAtIndex(reg_idx)) != nullptr; ++reg_idx) {635        size_including_slice_registers += reg_info->byte_size;636        if (reg_info->value_regs == nullptr)637          size_not_including_slice_registers += reg_info->byte_size;638        if (reg_info->byte_offset >= size_by_highest_offset)639          size_by_highest_offset = reg_info->byte_offset + reg_info->byte_size;640      }641 642      bool use_byte_offset_into_buffer;643      if (size_by_highest_offset == restore_data.GetByteSize()) {644        // The size of the packet agrees with the highest offset: + size in the645        // register file646        use_byte_offset_into_buffer = true;647      } else if (size_not_including_slice_registers ==648                 restore_data.GetByteSize()) {649        // The size of the packet is the same as concatenating all of the650        // registers sequentially, skipping the slice registers651        use_byte_offset_into_buffer = true;652      } else if (size_including_slice_registers == restore_data.GetByteSize()) {653        // The slice registers are present in the packet (when they shouldn't654        // be). Don't try to use the RegisterInfo byte_offset into the655        // restore_data, it will point to the wrong place.656        use_byte_offset_into_buffer = false;657      } else {658        // None of our expected sizes match the actual g packet data we're659        // looking at. The most conservative approach here is to use the660        // running total byte offset.661        use_byte_offset_into_buffer = false;662      }663 664      // In case our register definitions don't include the correct offsets,665      // keep track of the size of each reg & compute offset based on that.666      uint32_t running_byte_offset = 0;667      for (uint32_t reg_idx = 0;668           (reg_info = GetRegisterInfoAtIndex(reg_idx)) != nullptr;669           ++reg_idx, running_byte_offset += reg_info->byte_size) {670        // Skip composite aka slice registers (e.g. eax is a slice of rax).671        if (reg_info->value_regs)672          continue;673 674        const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];675 676        uint32_t register_offset;677        if (use_byte_offset_into_buffer) {678          register_offset = reg_info->byte_offset;679        } else {680          register_offset = running_byte_offset;681        }682 683        const uint32_t reg_byte_size = reg_info->byte_size;684 685        const uint8_t *restore_src =686            restore_data.PeekData(register_offset, reg_byte_size);687        if (restore_src) {688          SetRegisterIsValid(reg, false);689          if (gdb_comm.WriteRegister(690                  m_thread.GetProtocolID(),691                  reg_info->kinds[eRegisterKindProcessPlugin],692                  {restore_src, reg_byte_size}))693            ++num_restored;694        }695      }696      return num_restored > 0;697    } else {698      // For the use_g_packet == false case, we're going to write each register699      // individually.  The data buffer is binary data in this case, instead of700      // ascii characters.701 702      bool arm64_debugserver = false;703      if (m_thread.GetProcess().get()) {704        const ArchSpec &arch =705            m_thread.GetProcess()->GetTarget().GetArchitecture();706        if (arch.IsValid() && (arch.GetMachine() == llvm::Triple::aarch64 ||707                               arch.GetMachine() == llvm::Triple::aarch64_32) &&708            arch.GetTriple().getVendor() == llvm::Triple::Apple &&709            arch.GetTriple().getOS() == llvm::Triple::IOS) {710          arm64_debugserver = true;711        }712      }713      uint32_t num_restored = 0;714      const RegisterInfo *reg_info;715      for (uint32_t i = 0; (reg_info = GetRegisterInfoAtIndex(i)) != nullptr;716           i++) {717        if (reg_info->value_regs) // skip registers that are slices of real718                                  // registers719          continue;720        // Skip the fpsr and fpcr floating point status/control register721        // writing to work around a bug in an older version of debugserver that722        // would lead to register context corruption when writing fpsr/fpcr.723        if (arm64_debugserver && (strcmp(reg_info->name, "fpsr") == 0 ||724                                  strcmp(reg_info->name, "fpcr") == 0)) {725          continue;726        }727 728        SetRegisterIsValid(reg_info, false);729        if (gdb_comm.WriteRegister(m_thread.GetProtocolID(),730                                   reg_info->kinds[eRegisterKindProcessPlugin],731                                   {data_sp->GetBytes() + reg_info->byte_offset,732                                    reg_info->byte_size}))733          ++num_restored;734      }735      return num_restored > 0;736    }737  } else {738    Log *log(GetLog(GDBRLog::Thread | GDBRLog::Packets));739    if (log) {740      if (log->GetVerbose()) {741        StreamString strm;742        process->DumpPluginHistory(strm);743        LLDB_LOGF(log,744                  "error: failed to get packet sequence mutex, not sending "745                  "write all registers:\n%s",746                  strm.GetData());747      } else748        LLDB_LOGF(log,749                  "error: failed to get packet sequence mutex, not sending "750                  "write all registers");751    }752  }753  return false;754}755 756uint32_t GDBRemoteRegisterContext::ConvertRegisterKindToRegisterNumber(757    lldb::RegisterKind kind, uint32_t num) {758  return m_reg_info_sp->ConvertRegisterKindToRegisterNumber(kind, num);759}760 761bool GDBRemoteRegisterContext::RegisterWriteCausesReconfigure(762    const llvm::StringRef name) {763  ExecutionContext exe_ctx(CalculateThread());764  const Architecture *architecture =765      exe_ctx.GetProcessRef().GetTarget().GetArchitecturePlugin();766  return architecture && architecture->RegisterWriteCausesReconfigure(name);767}768 769bool GDBRemoteRegisterContext::ReconfigureRegisterInfo() {770  ExecutionContext exe_ctx(CalculateThread());771  const Architecture *architecture =772      exe_ctx.GetProcessRef().GetTarget().GetArchitecturePlugin();773  if (architecture)774    return architecture->ReconfigureRegisterInfo(*(m_reg_info_sp.get()),775                                                 m_reg_data, *this);776  return false;777}778