debugserver Mach exception messages and saved ports

kern_return_t MachException::Message::Reply(MachProcess *process, int signal) {
  // Reply to the exception...
  DNBError err;

  // If we had a soft signal, we need to update the thread first so it can
  // continue without signaling
  int soft_signal = state.SoftSignal();
  if (soft_signal) {
    int state_pid = -1;
    if (process->Task().TaskPort() == state.task_port) {
      // This is our task, so we can update the signal to send to it
      state_pid = process->ProcessID();
      soft_signal = signal;
    } else {
      err = ::pid_for_task(state.task_port, &state_pid);
    }

    assert(state_pid != -1);
    if (state_pid != -1) {
      errno = 0;
      if (::ptrace(PT_THUPDATE, state_pid,
                   (caddr_t)((uintptr_t)state.thread_port), soft_signal) != 0)
        err.SetError(errno, DNBError::POSIX);
      else
        err.Clear();

      if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail())
        err.LogThreaded("::ptrace (request = PT_THUPDATE, pid = 0x%4.4x, tid = "
                        "0x%4.4x, signal = %i)",
                        state_pid, state.thread_port, soft_signal);
… more in source

kern_return_t MachException::PortInfo::Save(task_t task) {
  DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE,
                   "MachException::PortInfo::Save ( task = 0x%4.4x )", task);
  // Be careful to be able to have debugserver built on a newer OS than what
  // it is currently running on by being able to start with all exceptions
  // and back off to just what is supported on the current system
  DNBError err;

  mask = LLDB_EXC_MASK;

  count = (sizeof(ports) / sizeof(ports[0]));
  err = ::task_get_exception_ports(task, mask, masks, &count, ports, behaviors,
                                   flavors);
  if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail())
    err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = 0x%x, "
                    "maskCnt => %u, ports, behaviors, flavors )",
                    task, mask, count);

  if (err.Status() == KERN_INVALID_ARGUMENT && mask != PREV_EXC_MASK_ALL) {
    mask = PREV_EXC_MASK_ALL;
    count = (sizeof(ports) / sizeof(ports[0]));
    err = ::task_get_exception_ports(task, mask, masks, &count, ports,
                                     behaviors, flavors);
    if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail())
      err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = "
                      "0x%x, maskCnt => %u, ports, behaviors, flavors )",
                      task, mask, count);
  }
  if (err.Fail()) {
    mask = 0;
… more in source

kern_return_t MachException::PortInfo::Restore(task_t task) {
  DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE,
                   "MachException::PortInfo::Restore( task = 0x%4.4x )", task);
  uint32_t i = 0;
  DNBError err;
  if (count > 0) {
    for (i = 0; i < count; i++) {
      err = ::task_set_exception_ports(task, masks[i], ports[i], behaviors[i],
                                       flavors[i]);
      if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) {
        err.LogThreaded("::task_set_exception_ports ( task = 0x%4.4x, "
                        "exception_mask = 0x%8.8x, new_port = 0x%4.4x, "
                        "behavior = 0x%8.8x, new_flavor = 0x%8.8x )",
                        task, masks[i], ports[i], behaviors[i], flavors[i]);
        // Bail if we encounter any errors
      }

      if (err.Fail())
        break;
    }
  }
  count = 0;
  return err.Status();
}