debugserver process launch, attach, stop, and resume

bool MachProcess::Resume(const DNBThreadResumeActions &thread_actions) {
  DNBLogThreadedIf(LOG_PROCESS, "MachProcess::Resume ()");
  nub_state_t state = GetState();

  if (CanResume(state)) {
    m_thread_actions = thread_actions;
    PrivateResume();
    return true;
  } else if (state == eStateRunning) {
    DNBLog("Resume() - task 0x%x is already running, ignoring...",
           m_task.TaskPort());
    return true;
  }
  DNBLog("Resume() - task 0x%x has state %s, can't continue...",
         m_task.TaskPort(), DNBStateAsString(state));
  return false;
}

void MachProcess::ReplyToAllExceptions() {
  std::lock_guard<std::recursive_mutex> guard(m_exception_and_signal_mutex);
  if (!m_exception_messages.empty()) {
    MachException::Message::iterator pos;
    MachException::Message::iterator begin = m_exception_messages.begin();
    MachException::Message::iterator end = m_exception_messages.end();
    for (pos = begin; pos != end; ++pos) {
      DNBLogThreadedIf(LOG_EXCEPTIONS, "Replying to exception %u...",
                       (uint32_t)std::distance(begin, pos));
      int thread_reply_signal = 0;

      nub_thread_t tid =
          m_thread_list.GetThreadIDByMachPortNumber(pos->state.thread_port);
      const DNBThreadResumeAction *action = NULL;
      if (tid != INVALID_NUB_THREAD) {
        action = m_thread_actions.GetActionForThread(tid, false);
      }

      if (action) {
        thread_reply_signal = action->signal;
        if (thread_reply_signal)
          m_thread_actions.SetSignalHandledForThread(tid);
      }

      DNBError err(pos->Reply(this, thread_reply_signal));
      if (DNBLogCheckLogBit(LOG_EXCEPTIONS))
        err.LogThreadedIfError("Error replying to exception");
    }

    // Erase all exception message as we should have used and replied
… more in source

void MachProcess::PrivateResume() {
  std::lock_guard<std::recursive_mutex> guard(m_exception_and_signal_mutex);

  m_auto_resume_signo = m_sent_interrupt_signo;
  if (m_auto_resume_signo)
    DNBLogThreadedIf(LOG_PROCESS, "MachProcess::PrivateResume() - task 0x%x "
                                  "resuming (with unhandled interrupt signal "
                                  "%i)...",
                     m_task.TaskPort(), m_auto_resume_signo);
  else
    DNBLogThreadedIf(LOG_PROCESS,
                     "MachProcess::PrivateResume() - task 0x%x resuming...",
                     m_task.TaskPort());

  ReplyToAllExceptions();
  //    bool stepOverBreakInstruction = step;

  // Let the thread prepare to resume and see if any threads want us to
  // step over a breakpoint instruction (ProcessWillResume will modify
  // the value of stepOverBreakInstruction).
  m_thread_list.ProcessWillResume(this, m_thread_actions);

  // Set our state accordingly
  if (m_thread_actions.NumActionsWithState(eStateStepping))
    SetState(eStateStepping);
  else
    SetState(eStateRunning);

  // Now resume our task.
  m_task.Resume();
… more in source

void MachProcess::ExceptionMessageReceived(
    const MachException::Message &exceptionMessage) {
  std::lock_guard<std::recursive_mutex> guard(m_exception_and_signal_mutex);

  if (m_exception_messages.empty())
    m_task.Suspend();

  DNBLogThreadedIf(LOG_EXCEPTIONS, "MachProcess::ExceptionMessageReceived ( )");

  // Use a locker to automatically unlock our mutex in case of exceptions
  // Add the exception to our internal exception stack
  m_exception_messages.push_back(exceptionMessage);
}

task_t MachProcess::ExceptionMessageBundleComplete() {
  // We have a complete bundle of exceptions for our child process.
  std::lock_guard<std::recursive_mutex> guard(m_exception_and_signal_mutex);
  DNBLogThreadedIf(LOG_EXCEPTIONS, "%s: %llu exception messages.",
                   __PRETTY_FUNCTION__, (uint64_t)m_exception_messages.size());
  bool auto_resume = false;
  if (!m_exception_messages.empty()) {
    m_did_exec = false;
    // First check for any SIGTRAP and make sure we didn't exec
    const task_t task = m_task.TaskPort();
    size_t i;
    if (m_pid != 0) {
      bool received_interrupt = false;
      uint32_t num_task_exceptions = 0;
      for (i = 0; i < m_exception_messages.size(); ++i) {
        if (m_exception_messages[i].state.task_port == task) {
          ++num_task_exceptions;
          const int signo = m_exception_messages[i].state.SoftSignal();
          if (signo == SIGTRAP) {
            // SIGTRAP could mean that we exec'ed. We need to check the
            // dyld all_image_infos.infoArray to see if it is NULL and if
            // so, say that we exec'ed.
            const nub_addr_t aii_addr = GetDYLDAllImageInfosAddress();
            if (aii_addr != INVALID_NUB_ADDRESS) {
              const nub_addr_t info_array_count_addr = aii_addr + 4;
              uint32_t info_array_count = 0;
              if (m_task.ReadMemory(info_array_count_addr, 4,
                                    &info_array_count) == 4) {
                if (info_array_count == 0) {
                  m_did_exec = true;
… more in source

pid_t MachProcess::AttachForDebug(
    pid_t pid, const RNBContext::IgnoredExceptions &ignored_exceptions,
    char *err_str, size_t err_len) {
  // Clear out and clean up from any current state
  Clear();
  if (pid != 0) {
    DNBError err;
    // Make sure the process exists...
    if (::getpgid(pid) < 0) {
      err.SetErrorToErrno();
      const char *err_cstr = err.AsString();
      ::snprintf(err_str, err_len, "%s",
                 err_cstr ? err_cstr : "No such process");
      DNBLogError ("MachProcess::AttachForDebug pid %d does not exist", pid);
      return INVALID_NUB_PROCESS;
    }

    SetState(eStateAttaching);
    m_pid = pid;
    if (!m_task.StartExceptionThread(ignored_exceptions, err)) {
      const char *err_cstr = err.AsString();
      ::snprintf(err_str, err_len, "%s",
                 err_cstr ? err_cstr : "unable to start the exception thread");
      DNBLogThreadedIf(LOG_PROCESS, "error: failed to attach to pid %d", pid);
      DNBLogError(
          "[LaunchAttach] END (%d) MachProcess::AttachForDebug failed to start "
          "exception thread attaching to pid %i: %s",
          getpid(), pid, err_str);
      m_pid = INVALID_NUB_PROCESS;
      return INVALID_NUB_PROCESS;
… more in source

pid_t MachProcess::PosixSpawnChildForPTraceDebugging(
    const char *path, cpu_type_t cpu_type, cpu_subtype_t cpu_subtype,
    char const *argv[], char const *envp[], const char *working_directory,
    const char *stdin_path, const char *stdout_path, const char *stderr_path,
    bool no_stdio, MachProcess *process, int disable_aslr, DNBError &err) {
  posix_spawnattr_t attr;
  short flags;
  DNBLogThreadedIf(LOG_PROCESS,
                   "%s ( path='%s', argv=%p, envp=%p, "
                   "working_dir=%s, stdin=%s, stdout=%s "
                   "stderr=%s, no-stdio=%i)",
                   __FUNCTION__, path, static_cast<const void *>(argv),
                   static_cast<const void *>(envp), working_directory,
                   stdin_path, stdout_path, stderr_path, no_stdio);

  err.SetError(::posix_spawnattr_init(&attr), DNBError::POSIX);
  if (err.Fail() || DNBLogCheckLogBit(LOG_PROCESS))
    err.LogThreaded("::posix_spawnattr_init ( &attr )");
  if (err.Fail())
    return INVALID_NUB_PROCESS;

  flags = POSIX_SPAWN_START_SUSPENDED | POSIX_SPAWN_SETSIGDEF |
          POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETPGROUP;
  if (disable_aslr)
    flags |= _POSIX_SPAWN_DISABLE_ASLR;

  sigset_t no_signals;
  sigset_t all_signals;
  sigemptyset(&no_signals);
  sigfillset(&all_signals);
… more in source