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1//===-- NativeProcessProtocol.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 "lldb/Host/common/NativeProcessProtocol.h"10#include "lldb/Host/Host.h"11#include "lldb/Host/common/NativeBreakpointList.h"12#include "lldb/Host/common/NativeRegisterContext.h"13#include "lldb/Host/common/NativeThreadProtocol.h"14#include "lldb/Utility/LLDBAssert.h"15#include "lldb/Utility/LLDBLog.h"16#include "lldb/Utility/Log.h"17#include "lldb/Utility/State.h"18#include "lldb/lldb-enumerations.h"19 20#include "llvm/Support/Process.h"21#include <optional>22 23using namespace lldb;24using namespace lldb_private;25 26// NativeProcessProtocol Members27 28NativeProcessProtocol::NativeProcessProtocol(lldb::pid_t pid, int terminal_fd,29                                             NativeDelegate &delegate)30    : m_pid(pid), m_delegate(delegate), m_terminal_fd(terminal_fd) {31  delegate.InitializeDelegate(this);32}33 34lldb_private::Status NativeProcessProtocol::Interrupt() {35  Status error;36#if !defined(SIGSTOP)37  error = Status::FromErrorString("local host does not support signaling");38  return error;39#else40  return Signal(SIGSTOP);41#endif42}43 44Status NativeProcessProtocol::IgnoreSignals(llvm::ArrayRef<int> signals) {45  m_signals_to_ignore.clear();46  m_signals_to_ignore.insert_range(signals);47  return Status();48}49 50lldb_private::Status51NativeProcessProtocol::GetMemoryRegionInfo(lldb::addr_t load_addr,52                                           MemoryRegionInfo &range_info) {53  // Default: not implemented.54  return Status::FromErrorString("not implemented");55}56 57lldb_private::Status58NativeProcessProtocol::ReadMemoryTags(int32_t type, lldb::addr_t addr,59                                      size_t len, std::vector<uint8_t> &tags) {60  return Status::FromErrorString("not implemented");61}62 63lldb_private::Status64NativeProcessProtocol::WriteMemoryTags(int32_t type, lldb::addr_t addr,65                                       size_t len,66                                       const std::vector<uint8_t> &tags) {67  return Status::FromErrorString("not implemented");68}69 70std::optional<WaitStatus> NativeProcessProtocol::GetExitStatus() {71  if (m_state == lldb::eStateExited)72    return m_exit_status;73 74  return std::nullopt;75}76 77bool NativeProcessProtocol::SetExitStatus(WaitStatus status,78                                          bool bNotifyStateChange) {79  Log *log = GetLog(LLDBLog::Process);80  LLDB_LOG(log, "status = {0}, notify = {1}", status, bNotifyStateChange);81 82  // Exit status already set83  if (m_state == lldb::eStateExited) {84    if (m_exit_status)85      LLDB_LOG(log, "exit status already set to {0}", *m_exit_status);86    else87      LLDB_LOG(log, "state is exited, but status not set");88    return false;89  }90 91  m_state = lldb::eStateExited;92  m_exit_status = status;93 94  if (bNotifyStateChange)95    SynchronouslyNotifyProcessStateChanged(lldb::eStateExited);96 97  return true;98}99 100NativeThreadProtocol *NativeProcessProtocol::GetThreadAtIndex(uint32_t idx) {101  std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);102  if (idx < m_threads.size())103    return m_threads[idx].get();104  return nullptr;105}106 107NativeThreadProtocol *108NativeProcessProtocol::GetThreadByIDUnlocked(lldb::tid_t tid) {109  for (const auto &thread : m_threads) {110    if (thread->GetID() == tid)111      return thread.get();112  }113  return nullptr;114}115 116NativeThreadProtocol *NativeProcessProtocol::GetThreadByID(lldb::tid_t tid) {117  std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);118  return GetThreadByIDUnlocked(tid);119}120 121bool NativeProcessProtocol::IsAlive() const {122  return m_state != eStateDetached && m_state != eStateExited &&123         m_state != eStateInvalid && m_state != eStateUnloaded;124}125 126const NativeWatchpointList::WatchpointMap &127NativeProcessProtocol::GetWatchpointMap() const {128  return m_watchpoint_list.GetWatchpointMap();129}130 131std::optional<std::pair<uint32_t, uint32_t>>132NativeProcessProtocol::GetHardwareDebugSupportInfo() const {133  Log *log = GetLog(LLDBLog::Process);134 135  // get any thread136  NativeThreadProtocol *thread(137      const_cast<NativeProcessProtocol *>(this)->GetThreadAtIndex(0));138  if (!thread) {139    LLDB_LOG(log, "failed to find a thread to grab a NativeRegisterContext!");140    return std::nullopt;141  }142 143  NativeRegisterContext &reg_ctx = thread->GetRegisterContext();144  return std::make_pair(reg_ctx.NumSupportedHardwareBreakpoints(),145                        reg_ctx.NumSupportedHardwareWatchpoints());146}147 148Status NativeProcessProtocol::SetWatchpoint(lldb::addr_t addr, size_t size,149                                            uint32_t watch_flags,150                                            bool hardware) {151  // This default implementation assumes setting the watchpoint for the process152  // will require setting the watchpoint for each of the threads.  Furthermore,153  // it will track watchpoints set for the process and will add them to each154  // thread that is attached to via the (FIXME implement) OnThreadAttached ()155  // method.156 157  Log *log = GetLog(LLDBLog::Process);158 159  // Update the thread list160  UpdateThreads();161 162  // Keep track of the threads we successfully set the watchpoint for.  If one163  // of the thread watchpoint setting operations fails, back off and remove the164  // watchpoint for all the threads that were successfully set so we get back165  // to a consistent state.166  std::vector<NativeThreadProtocol *> watchpoint_established_threads;167 168  // Tell each thread to set a watchpoint.  In the event that hardware169  // watchpoints are requested but the SetWatchpoint fails, try to set a170  // software watchpoint as a fallback.  It's conceivable that if there are171  // more threads than hardware watchpoints available, some of the threads will172  // fail to set hardware watchpoints while software ones may be available.173  std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);174  for (const auto &thread : m_threads) {175    assert(thread && "thread list should not have a NULL thread!");176 177    Status thread_error =178        thread->SetWatchpoint(addr, size, watch_flags, hardware);179    if (thread_error.Fail() && hardware) {180      // Try software watchpoints since we failed on hardware watchpoint181      // setting and we may have just run out of hardware watchpoints.182      thread_error = thread->SetWatchpoint(addr, size, watch_flags, false);183      if (thread_error.Success())184        LLDB_LOG(log,185                 "hardware watchpoint requested but software watchpoint set");186    }187 188    if (thread_error.Success()) {189      // Remember that we set this watchpoint successfully in case we need to190      // clear it later.191      watchpoint_established_threads.push_back(thread.get());192    } else {193      // Unset the watchpoint for each thread we successfully set so that we194      // get back to a consistent state of "not set" for the watchpoint.195      for (auto unwatch_thread_sp : watchpoint_established_threads) {196        Status remove_error = unwatch_thread_sp->RemoveWatchpoint(addr);197        if (remove_error.Fail())198          LLDB_LOG(log, "RemoveWatchpoint failed for pid={0}, tid={1}: {2}",199                   GetID(), unwatch_thread_sp->GetID(), remove_error);200      }201 202      return thread_error;203    }204  }205  return m_watchpoint_list.Add(addr, size, watch_flags, hardware);206}207 208Status NativeProcessProtocol::RemoveWatchpoint(lldb::addr_t addr) {209  // Update the thread list210  UpdateThreads();211 212  Status overall_error;213 214  std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);215  for (const auto &thread : m_threads) {216    assert(thread && "thread list should not have a NULL thread!");217 218    Status thread_error = thread->RemoveWatchpoint(addr);219    if (thread_error.Fail()) {220      // Keep track of the first thread error if any threads fail. We want to221      // try to remove the watchpoint from every thread, though, even if one or222      // more have errors.223      if (!overall_error.Fail())224        overall_error = std::move(thread_error);225    }226  }227  Status error = m_watchpoint_list.Remove(addr);228  return overall_error.Fail() ? std::move(overall_error) : std::move(error);229}230 231const HardwareBreakpointMap &232NativeProcessProtocol::GetHardwareBreakpointMap() const {233  return m_hw_breakpoints_map;234}235 236Status NativeProcessProtocol::SetHardwareBreakpoint(lldb::addr_t addr,237                                                    size_t size) {238  // This default implementation assumes setting a hardware breakpoint for this239  // process will require setting same hardware breakpoint for each of its240  // existing threads. New thread will do the same once created.241  Log *log = GetLog(LLDBLog::Process);242 243  // Update the thread list244  UpdateThreads();245 246  // Exit here if target does not have required hardware breakpoint capability.247  auto hw_debug_cap = GetHardwareDebugSupportInfo();248 249  if (hw_debug_cap == std::nullopt || hw_debug_cap->first == 0 ||250      hw_debug_cap->first <= m_hw_breakpoints_map.size())251    return Status::FromErrorString(252        "Target does not have required no of hardware breakpoints");253 254  // Vector below stores all thread pointer for which we have we successfully255  // set this hardware breakpoint. If any of the current process threads fails256  // to set this hardware breakpoint then roll back and remove this breakpoint257  // for all the threads that had already set it successfully.258  std::vector<NativeThreadProtocol *> breakpoint_established_threads;259 260  // Request to set a hardware breakpoint for each of current process threads.261  std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);262  for (const auto &thread : m_threads) {263    assert(thread && "thread list should not have a NULL thread!");264 265    Status thread_error = thread->SetHardwareBreakpoint(addr, size);266    if (thread_error.Success()) {267      // Remember that we set this breakpoint successfully in case we need to268      // clear it later.269      breakpoint_established_threads.push_back(thread.get());270    } else {271      // Unset the breakpoint for each thread we successfully set so that we272      // get back to a consistent state of "not set" for this hardware273      // breakpoint.274      for (auto rollback_thread_sp : breakpoint_established_threads) {275        Status remove_error =276            rollback_thread_sp->RemoveHardwareBreakpoint(addr);277        if (remove_error.Fail())278          LLDB_LOG(log,279                   "RemoveHardwareBreakpoint failed for pid={0}, tid={1}: {2}",280                   GetID(), rollback_thread_sp->GetID(), remove_error);281      }282 283      return thread_error;284    }285  }286 287  // Register new hardware breakpoint into hardware breakpoints map of current288  // process.289  m_hw_breakpoints_map[addr] = {addr, size};290 291  return Status();292}293 294Status NativeProcessProtocol::RemoveHardwareBreakpoint(lldb::addr_t addr) {295  // Update the thread list296  UpdateThreads();297 298  Status error;299 300  std::lock_guard<std::recursive_mutex> guard(m_threads_mutex);301  for (const auto &thread : m_threads) {302    assert(thread && "thread list should not have a NULL thread!");303    error = thread->RemoveHardwareBreakpoint(addr);304  }305 306  // Also remove from hardware breakpoint map of current process.307  m_hw_breakpoints_map.erase(addr);308 309  return error;310}311 312void NativeProcessProtocol::SynchronouslyNotifyProcessStateChanged(313    lldb::StateType state) {314  Log *log = GetLog(LLDBLog::Process);315 316  m_delegate.ProcessStateChanged(this, state);317 318  switch (state) {319  case eStateStopped:320  case eStateExited:321  case eStateCrashed:322    NotifyTracersProcessDidStop();323    break;324  default:325    break;326  }327 328  LLDB_LOG(log, "sent state notification [{0}] from process {1}", state,329           GetID());330}331 332void NativeProcessProtocol::NotifyDidExec() {333  Log *log = GetLog(LLDBLog::Process);334  LLDB_LOG(log, "process {0} exec()ed", GetID());335 336  m_software_breakpoints.clear();337 338  m_delegate.DidExec(this);339}340 341Status NativeProcessProtocol::SetSoftwareBreakpoint(lldb::addr_t addr,342                                                    uint32_t size_hint) {343  Log *log = GetLog(LLDBLog::Breakpoints);344  LLDB_LOG(log, "addr = {0:x}, size_hint = {1}", addr, size_hint);345 346  auto it = m_software_breakpoints.find(addr);347  if (it != m_software_breakpoints.end()) {348    ++it->second.ref_count;349    return Status();350  }351  auto expected_bkpt = EnableSoftwareBreakpoint(addr, size_hint);352  if (!expected_bkpt)353    return Status::FromError(expected_bkpt.takeError());354 355  m_software_breakpoints.emplace(addr, std::move(*expected_bkpt));356  return Status();357}358 359Status NativeProcessProtocol::RemoveSoftwareBreakpoint(lldb::addr_t addr) {360  Log *log = GetLog(LLDBLog::Breakpoints);361  LLDB_LOG(log, "addr = {0:x}", addr);362  auto it = m_software_breakpoints.find(addr);363  if (it == m_software_breakpoints.end())364    return Status::FromErrorString("Breakpoint not found.");365  assert(it->second.ref_count > 0);366  if (--it->second.ref_count > 0)367    return Status();368 369  // Remove the entry from m_software_breakpoints rightaway, so that we don't370  // leave behind an entry with ref_count == 0 in case one of the following371  // conditions returns an error. The breakpoint is moved so that it can be372  // accessed below.373  SoftwareBreakpoint bkpt = std::move(it->second);374  m_software_breakpoints.erase(it);375 376  // This is the last reference. Let's remove the breakpoint.377  Status error;378 379  // Clear a software breakpoint instruction380  llvm::SmallVector<uint8_t, 4> curr_break_op(bkpt.breakpoint_opcodes.size(),381                                              0);382 383  // Read the breakpoint opcode384  size_t bytes_read = 0;385  error =386      ReadMemory(addr, curr_break_op.data(), curr_break_op.size(), bytes_read);387  if (error.Fail() || bytes_read < curr_break_op.size()) {388    return Status::FromErrorStringWithFormat(389        "addr=0x%" PRIx64 ": tried to read %zu bytes but only read %zu", addr,390        curr_break_op.size(), bytes_read);391  }392  const auto &saved = bkpt.saved_opcodes;393  // Make sure the breakpoint opcode exists at this address394  if (llvm::ArrayRef(curr_break_op) != bkpt.breakpoint_opcodes) {395    if (curr_break_op != bkpt.saved_opcodes)396      return Status::FromErrorString(397          "Original breakpoint trap is no longer in memory.");398    LLDB_LOG(log,399             "Saved opcodes ({0:@[x]}) have already been restored at {1:x}.",400             llvm::make_range(saved.begin(), saved.end()), addr);401  } else {402    // We found a valid breakpoint opcode at this address, now restore the403    // saved opcode.404    size_t bytes_written = 0;405    error = WriteMemory(addr, saved.data(), saved.size(), bytes_written);406    if (error.Fail() || bytes_written < saved.size()) {407      return Status::FromErrorStringWithFormat(408          "addr=0x%" PRIx64 ": tried to write %zu bytes but only wrote %zu",409          addr, saved.size(), bytes_written);410    }411 412    // Verify that our original opcode made it back to the inferior413    llvm::SmallVector<uint8_t, 4> verify_opcode(saved.size(), 0);414    size_t verify_bytes_read = 0;415    error = ReadMemory(addr, verify_opcode.data(), verify_opcode.size(),416                       verify_bytes_read);417    if (error.Fail() || verify_bytes_read < verify_opcode.size()) {418      return Status::FromErrorStringWithFormat(419          "addr=0x%" PRIx64420          ": tried to read %zu verification bytes but only read %zu",421          addr, verify_opcode.size(), verify_bytes_read);422    }423    if (verify_opcode != saved)424      LLDB_LOG(log, "Restoring bytes at {0:x}: {1:@[x]}", addr,425               llvm::make_range(saved.begin(), saved.end()));426  }427 428  return Status();429}430 431llvm::Expected<NativeProcessProtocol::SoftwareBreakpoint>432NativeProcessProtocol::EnableSoftwareBreakpoint(lldb::addr_t addr,433                                                uint32_t size_hint) {434  Log *log = GetLog(LLDBLog::Breakpoints);435 436  auto expected_trap = GetSoftwareBreakpointTrapOpcode(size_hint);437  if (!expected_trap)438    return expected_trap.takeError();439 440  llvm::SmallVector<uint8_t, 4> saved_opcode_bytes(expected_trap->size(), 0);441  // Save the original opcodes by reading them so we can restore later.442  size_t bytes_read = 0;443  Status error = ReadMemory(addr, saved_opcode_bytes.data(),444                            saved_opcode_bytes.size(), bytes_read);445  if (error.Fail())446    return error.ToError();447 448  // Ensure we read as many bytes as we expected.449  if (bytes_read != saved_opcode_bytes.size()) {450    return llvm::createStringError(451        llvm::inconvertibleErrorCode(),452        "Failed to read memory while attempting to set breakpoint: attempted "453        "to read {0} bytes but only read {1}.",454        saved_opcode_bytes.size(), bytes_read);455  }456 457  LLDB_LOG(458      log, "Overwriting bytes at {0:x}: {1:@[x]}", addr,459      llvm::make_range(saved_opcode_bytes.begin(), saved_opcode_bytes.end()));460 461  // Write a software breakpoint in place of the original opcode.462  size_t bytes_written = 0;463  error = WriteMemory(addr, expected_trap->data(), expected_trap->size(),464                      bytes_written);465  if (error.Fail())466    return error.ToError();467 468  // Ensure we wrote as many bytes as we expected.469  if (bytes_written != expected_trap->size()) {470    return llvm::createStringError(471        llvm::inconvertibleErrorCode(),472        "Failed write memory while attempting to set "473        "breakpoint: attempted to write {0} bytes but only wrote {1}",474        expected_trap->size(), bytes_written);475  }476 477  llvm::SmallVector<uint8_t, 4> verify_bp_opcode_bytes(expected_trap->size(),478                                                       0);479  size_t verify_bytes_read = 0;480  error = ReadMemory(addr, verify_bp_opcode_bytes.data(),481                     verify_bp_opcode_bytes.size(), verify_bytes_read);482  if (error.Fail())483    return error.ToError();484 485  // Ensure we read as many verification bytes as we expected.486  if (verify_bytes_read != verify_bp_opcode_bytes.size()) {487    return llvm::createStringError(488        llvm::inconvertibleErrorCode(),489        "Failed to read memory while "490        "attempting to verify breakpoint: attempted to read {0} bytes "491        "but only read {1}",492        verify_bp_opcode_bytes.size(), verify_bytes_read);493  }494 495  if (llvm::ArrayRef(verify_bp_opcode_bytes.data(), verify_bytes_read) !=496      *expected_trap) {497    return llvm::createStringError(498        llvm::inconvertibleErrorCode(),499        "Verification of software breakpoint "500        "writing failed - trap opcodes not successfully read back "501        "after writing when setting breakpoint at {0:x}",502        addr);503  }504 505  LLDB_LOG(log, "addr = {0:x}: SUCCESS", addr);506  return SoftwareBreakpoint{1, saved_opcode_bytes, *expected_trap};507}508 509llvm::Expected<llvm::ArrayRef<uint8_t>>510NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode(size_t size_hint) {511  static const uint8_t g_aarch64_opcode[] = {0x00, 0x00, 0x20, 0xd4};512  static const uint8_t g_i386_opcode[] = {0xCC};513  static const uint8_t g_mips64_opcode[] = {0x00, 0x00, 0x00, 0x0d};514  static const uint8_t g_mips64el_opcode[] = {0x0d, 0x00, 0x00, 0x00};515  static const uint8_t g_msp430_opcode[] = {0x43, 0x43};516  static const uint8_t g_s390x_opcode[] = {0x00, 0x01};517  static const uint8_t g_ppc_opcode[] = {0x7f, 0xe0, 0x00, 0x08};   // trap518  static const uint8_t g_ppcle_opcode[] = {0x08, 0x00, 0xe0, 0x7f}; // trap519  static const uint8_t g_riscv_opcode[] = {0x73, 0x00, 0x10, 0x00}; // ebreak520  static const uint8_t g_riscv_opcode_c[] = {0x02, 0x90};           // c.ebreak521  static const uint8_t g_loongarch_opcode[] = {0x05, 0x00, 0x2a,522                                               0x00}; // break 0x5523 524  switch (GetArchitecture().GetMachine()) {525  case llvm::Triple::aarch64:526  case llvm::Triple::aarch64_32:527    return llvm::ArrayRef(g_aarch64_opcode);528 529  case llvm::Triple::x86:530  case llvm::Triple::x86_64:531    return llvm::ArrayRef(g_i386_opcode);532 533  case llvm::Triple::mips:534  case llvm::Triple::mips64:535    return llvm::ArrayRef(g_mips64_opcode);536 537  case llvm::Triple::mipsel:538  case llvm::Triple::mips64el:539    return llvm::ArrayRef(g_mips64el_opcode);540 541  case llvm::Triple::msp430:542    return llvm::ArrayRef(g_msp430_opcode);543 544  case llvm::Triple::systemz:545    return llvm::ArrayRef(g_s390x_opcode);546 547  case llvm::Triple::ppc:548  case llvm::Triple::ppc64:549    return llvm::ArrayRef(g_ppc_opcode);550 551  case llvm::Triple::ppc64le:552    return llvm::ArrayRef(g_ppcle_opcode);553 554  case llvm::Triple::riscv32:555  case llvm::Triple::riscv64: {556    return size_hint == 2 ? llvm::ArrayRef(g_riscv_opcode_c)557                          : llvm::ArrayRef(g_riscv_opcode);558  }559 560  case llvm::Triple::loongarch32:561  case llvm::Triple::loongarch64:562    return llvm::ArrayRef(g_loongarch_opcode);563 564  default:565    return llvm::createStringError(llvm::inconvertibleErrorCode(),566                                   "CPU type not supported!");567  }568}569 570size_t NativeProcessProtocol::GetSoftwareBreakpointPCOffset() {571  switch (GetArchitecture().GetMachine()) {572  case llvm::Triple::x86:573  case llvm::Triple::x86_64:574  case llvm::Triple::systemz:575    // These architectures report increment the PC after breakpoint is hit.576    return cantFail(GetSoftwareBreakpointTrapOpcode(0)).size();577 578  case llvm::Triple::arm:579  case llvm::Triple::aarch64:580  case llvm::Triple::aarch64_32:581  case llvm::Triple::mips64:582  case llvm::Triple::mips64el:583  case llvm::Triple::mips:584  case llvm::Triple::mipsel:585  case llvm::Triple::ppc:586  case llvm::Triple::ppc64:587  case llvm::Triple::ppc64le:588  case llvm::Triple::riscv32:589  case llvm::Triple::riscv64:590  case llvm::Triple::loongarch32:591  case llvm::Triple::loongarch64:592    // On these architectures the PC doesn't get updated for breakpoint hits.593    return 0;594 595  default:596    llvm_unreachable("CPU type not supported!");597  }598}599 600void NativeProcessProtocol::FixupBreakpointPCAsNeeded(601    NativeThreadProtocol &thread) {602  Log *log = GetLog(LLDBLog::Breakpoints);603 604  Status error;605 606  // Find out the size of a breakpoint (might depend on where we are in the607  // code).608  NativeRegisterContext &context = thread.GetRegisterContext();609 610  uint32_t breakpoint_size = GetSoftwareBreakpointPCOffset();611  LLDB_LOG(log, "breakpoint size: {0}", breakpoint_size);612  if (breakpoint_size == 0)613    return;614 615  // First try probing for a breakpoint at a software breakpoint location: PC -616  // breakpoint size.617  const lldb::addr_t initial_pc_addr = context.GetPCfromBreakpointLocation();618  lldb::addr_t breakpoint_addr = initial_pc_addr;619  // Do not allow breakpoint probe to wrap around.620  if (breakpoint_addr >= breakpoint_size)621    breakpoint_addr -= breakpoint_size;622 623  if (m_software_breakpoints.count(breakpoint_addr) == 0) {624    // We didn't find one at a software probe location.  Nothing to do.625    LLDB_LOG(log,626             "pid {0} no lldb software breakpoint found at current pc with "627             "adjustment: {1}",628             GetID(), breakpoint_addr);629    return;630  }631 632  //633  // We have a software breakpoint and need to adjust the PC.634  //635 636  // Change the program counter.637  LLDB_LOG(log, "pid {0} tid {1}: changing PC from {2:x} to {3:x}", GetID(),638           thread.GetID(), initial_pc_addr, breakpoint_addr);639 640  error = context.SetPC(breakpoint_addr);641  if (error.Fail()) {642    // This can happen in case the process was killed between the time we read643    // the PC and when we are updating it. There's nothing better to do than to644    // swallow the error.645    LLDB_LOG(log, "pid {0} tid {1}: failed to set PC: {2}", GetID(),646             thread.GetID(), error);647  }648}649 650Status NativeProcessProtocol::RemoveBreakpoint(lldb::addr_t addr,651                                               bool hardware) {652  if (hardware)653    return RemoveHardwareBreakpoint(addr);654  else655    return RemoveSoftwareBreakpoint(addr);656}657 658Status NativeProcessProtocol::ReadMemoryWithoutTrap(lldb::addr_t addr,659                                                    void *buf, size_t size,660                                                    size_t &bytes_read) {661  Status error = ReadMemory(addr, buf, size, bytes_read);662  if (error.Fail())663    return error;664 665  llvm::MutableArrayRef data(static_cast<uint8_t *>(buf), bytes_read);666  for (const auto &pair : m_software_breakpoints) {667    lldb::addr_t bp_addr = pair.first;668    auto saved_opcodes = llvm::ArrayRef(pair.second.saved_opcodes);669 670    if (bp_addr + saved_opcodes.size() < addr || addr + bytes_read <= bp_addr)671      continue; // Breakpoint not in range, ignore672 673    if (bp_addr < addr) {674      saved_opcodes = saved_opcodes.drop_front(addr - bp_addr);675      bp_addr = addr;676    }677    auto bp_data = data.drop_front(bp_addr - addr);678    std::copy_n(saved_opcodes.begin(),679                std::min(saved_opcodes.size(), bp_data.size()),680                bp_data.begin());681  }682  return Status();683}684 685llvm::Expected<llvm::StringRef>686NativeProcessProtocol::ReadCStringFromMemory(lldb::addr_t addr, char *buffer,687                                             size_t max_size,688                                             size_t &total_bytes_read) {689  static const size_t cache_line_size =690      llvm::sys::Process::getPageSizeEstimate();691  size_t bytes_read = 0;692  size_t bytes_left = max_size;693  addr_t curr_addr = addr;694  size_t string_size;695  char *curr_buffer = buffer;696  total_bytes_read = 0;697  Status status;698 699  while (bytes_left > 0 && status.Success()) {700    addr_t cache_line_bytes_left =701        cache_line_size - (curr_addr % cache_line_size);702    addr_t bytes_to_read = std::min<addr_t>(bytes_left, cache_line_bytes_left);703    status = ReadMemory(curr_addr, static_cast<void *>(curr_buffer),704                        bytes_to_read, bytes_read);705 706    if (bytes_read == 0)707      break;708 709    void *str_end = std::memchr(curr_buffer, '\0', bytes_read);710    if (str_end != nullptr) {711      total_bytes_read =712          static_cast<size_t>((static_cast<char *>(str_end) - buffer + 1));713      status.Clear();714      break;715    }716 717    total_bytes_read += bytes_read;718    curr_buffer += bytes_read;719    curr_addr += bytes_read;720    bytes_left -= bytes_read;721  }722 723  string_size = total_bytes_read - 1;724 725  // Make sure we return a null terminated string.726  if (bytes_left == 0 && max_size > 0 && buffer[max_size - 1] != '\0') {727    buffer[max_size - 1] = '\0';728    total_bytes_read--;729  }730 731  if (!status.Success())732    return status.ToError();733 734  return llvm::StringRef(buffer, string_size);735}736 737lldb::StateType NativeProcessProtocol::GetState() const {738  std::lock_guard<std::recursive_mutex> guard(m_state_mutex);739  return m_state;740}741 742void NativeProcessProtocol::SetState(lldb::StateType state,743                                     bool notify_delegates) {744  std::lock_guard<std::recursive_mutex> guard(m_state_mutex);745 746  if (state == m_state)747    return;748 749  m_state = state;750 751  if (StateIsStoppedState(state, false)) {752    ++m_stop_id;753 754    // Give process a chance to do any stop id bump processing, such as755    // clearing cached data that is invalidated each time the process runs.756    // Note if/when we support some threads running, we'll end up needing to757    // manage this per thread and per process.758    DoStopIDBumped(m_stop_id);759  }760 761  // Optionally notify delegates of the state change.762  if (notify_delegates)763    SynchronouslyNotifyProcessStateChanged(state);764}765 766uint32_t NativeProcessProtocol::GetStopID() const {767  std::lock_guard<std::recursive_mutex> guard(m_state_mutex);768  return m_stop_id;769}770 771void NativeProcessProtocol::DoStopIDBumped(uint32_t /* newBumpId */) {772  // Default implementation does nothing.773}774 775NativeProcessProtocol::Manager::~Manager() = default;776