server.c

xen虚拟机源代码安装包

extern control_c_pressed_flag;
#include <signal.h>

void ctrl_c_handler(int signo)
{
    printf("Ctrl-C pressed: Quit from the attached gdb first\n");
    control_c_pressed_flag = 1;
}

struct sigaction ctrl_c_sigaction = { .sa_handler = ctrl_c_handler };
struct sigaction old_sigaction;

int
main (int argc, char *argv[])
{
  char ch, status, *own_buf, mem_buf[2000];
  int i = 0;
  unsigned char signal;
  unsigned int len;
  CORE_ADDR mem_addr;
  int bad_attach;
  int pid;
  char *arg_end;

  if (setjmp (toplevel))
    {
      fprintf (stderr, "Exiting\n");
      exit (1);
    }

  bad_attach = 0;
  pid = 0;
  attached = 0;
  if (argc >= 3 && strcmp (argv[2], "--attach") == 0)
    {
      if (argc == 4
	  && argv[3] != '\0'
	  && (pid = strtoul (argv[3], &arg_end, 10)) != 0
	  && *arg_end == '\0')
	{
	  ;
	}
      else
	bad_attach = 1;
    }
  else if (argc >= 3 && strcmp (argv[2], "--file") == 0)
    {
      if (argc == 4
	  && argv[3] != '\0')
	{
	  if ((pid = open(argv[3], O_RDONLY)) <= 0) 
	    bad_attach = 1;
	  else 
	    isfile = 1;
	}
      else
	bad_attach = 1;
    }

  if (argc < 3 || bad_attach)
    gdbserver_usage();

  initialize_low ();

  own_buf = malloc (PBUFSIZ);

  if (pid == 0)
    {
      /* Wait till we are at first instruction in program.  */
      signal = start_inferior (&argv[2], &status);

      /* We are now stopped at the first instruction of the target process */
    }
  else
    {
      switch (attach_inferior (pid, &status, &signal))
	{
	case -1:
	  error ("Attaching not supported on this target");
	  break;
	default:
	  attached = 1;
	  break;
	}
    }


  while (1)
    {
      remote_open (argv[1]);
      sigaction(SIGINT, &ctrl_c_sigaction, &old_sigaction);

    restart:
      setjmp (toplevel);
      while (getpkt (own_buf) > 0)
	{
	  unsigned char sig;
	  i = 0;
	  ch = own_buf[i++];
	  switch (ch)
	    {
	    case 'q':
	      handle_query (own_buf);
	      break;
	    case 'd':
	      remote_debug = !remote_debug;
	      break;
	    case 'D':
	      fprintf (stderr, "Detaching from inferior\n");
	      detach_inferior ();
	      write_ok (own_buf);
	      putpkt (own_buf);
	      remote_close ();

	      /* If we are attached, then we can exit.  Otherwise, we need to
		 hang around doing nothing, until the child is gone.  */
	      if (!attached)
		{
		  int status, ret;

		  do {
		    ret = waitpid (signal_pid, &status, 0);
		    if (WIFEXITED (status) || WIFSIGNALED (status))
		      break;
		  } while (ret != -1 || errno != ECHILD);
		}

	      exit (0);

	    case '!':
	      if (attached == 0)
		{
		  extended_protocol = 1;
		  prepare_resume_reply (own_buf, status, signal);
		}
	      else
		{
		  /* We can not use the extended protocol if we are
		     attached, because we can not restart the running
		     program.  So return unrecognized.  */
		  own_buf[0] = '\0';
		}
	      break;
	    case '?':
	      prepare_resume_reply (own_buf, status, signal);
	      break;
	    case 'H':
	      switch (own_buf[1])
		{
		case 'g':
		  general_thread = strtol (&own_buf[2], NULL, 16);
		  write_ok (own_buf);
		  set_desired_inferior (1);
		  break;
		case 'c':
		  cont_thread = strtol (&own_buf[2], NULL, 16);
		  write_ok (own_buf);
		  break;
		case 's':
		  step_thread = strtol (&own_buf[2], NULL, 16);
		  write_ok (own_buf);
		  break;
		default:
		  /* Silently ignore it so that gdb can extend the protocol
		     without compatibility headaches.  */
		  own_buf[0] = '\0';
		  break;
		}
	      break;
	    case 'g':
	      set_desired_inferior (1);
	      registers_to_string (own_buf);
	      break;
	    case 'G':
	      set_desired_inferior (1);
	      registers_from_string (&own_buf[1]);
	      write_ok (own_buf);
	      break;
	    case 'm':
	      decode_m_packet (&own_buf[1], &mem_addr, &len);
	      if (read_inferior_memory (mem_addr, mem_buf, len) == 0)
		convert_int_to_ascii (mem_buf, own_buf, len);
	      else
		write_enn (own_buf);
	      break;
	    case 'M':
	      decode_M_packet (&own_buf[1], &mem_addr, &len, mem_buf);
	      if (write_inferior_memory (mem_addr, mem_buf, len) == 0)
		write_ok (own_buf);
	      else
		write_enn (own_buf);
	      break;
	    case 'C':
	      convert_ascii_to_int (own_buf + 1, &sig, 1);
	      if (target_signal_to_host_p (sig))
		signal = target_signal_to_host (sig);
	      else
		signal = 0;
	      set_desired_inferior (0);
	      myresume (0, signal);
	      signal = mywait (&status, 1);
	      prepare_resume_reply (own_buf, status, signal);
	      break;
	    case 'S':
	      convert_ascii_to_int (own_buf + 1, &sig, 1);
	      if (target_signal_to_host_p (sig))
		signal = target_signal_to_host (sig);
	      else
		signal = 0;
	      set_desired_inferior (0);
	      myresume (1, signal);
	      signal = mywait (&status, 1);
	      prepare_resume_reply (own_buf, status, signal);
	      break;
	    case 'c':
	      set_desired_inferior (0);
	      myresume (0, 0);
	      signal = mywait (&status, 1);
	      prepare_resume_reply (own_buf, status, signal);
	      break;
	    case 's':
	      set_desired_inferior (0);
	      myresume (1, 0);
	      signal = mywait (&status, 1);
	      prepare_resume_reply (own_buf, status, signal);
	      break;
	    case 'k':
	      fprintf (stderr, "Killing inferior\n");
	      kill_inferior ();
	      /* When using the extended protocol, we start up a new
	         debugging session.   The traditional protocol will
	         exit instead.  */
	      if (extended_protocol)
		{
		  write_ok (own_buf);
		  fprintf (stderr, "GDBserver restarting\n");

		  /* Wait till we are at 1st instruction in prog.  */
		  signal = start_inferior (&argv[2], &status);
		  goto restart;
		  break;
		}
	      else
		{
		  exit (0);
		  break;
		}
	    case 'T':
	      if (mythread_alive (strtol (&own_buf[1], NULL, 16)))
		write_ok (own_buf);
	      else
		write_enn (own_buf);
	      break;
	    case 'R':
	      /* Restarting the inferior is only supported in the
	         extended protocol.  */
	      if (extended_protocol)
		{
		  kill_inferior ();
		  write_ok (own_buf);
		  fprintf (stderr, "GDBserver restarting\n");

		  /* Wait till we are at 1st instruction in prog.  */
		  signal = start_inferior (&argv[2], &status);
		  goto restart;
		  break;
		}
	      else
		{
		  /* It is a request we don't understand.  Respond with an
		     empty packet so that gdb knows that we don't support this
		     request.  */
		  own_buf[0] = '\0';
		  break;
		}
	    case 'v':
	      /* Extended (long) request.  */
	      handle_v_requests (own_buf, &status, &signal);
	      break;
	    case 'Z':
	      handle_breakpoint_requests (own_buf, &status, &signal);
	      break;
	    default:
	      /* It is a request we don't understand.  Respond with an
	         empty packet so that gdb knows that we don't support this
	         request.  */
	      own_buf[0] = '\0';
	      break;
	    }

	  putpkt (own_buf);

	  if (status == 'W')
	    fprintf (stderr,
		     "\nChild exited with status %d\n", signal);
	  if (status == 'X')
	    fprintf (stderr, "\nChild terminated with signal = 0x%x\n",
		     signal);
	  if (status == 'W' || status == 'X')
	    {
	      if (extended_protocol)
		{
		  fprintf (stderr, "Killing inferior\n");
		  kill_inferior ();
		  write_ok (own_buf);
		  fprintf (stderr, "GDBserver restarting\n");

		  /* Wait till we are at 1st instruction in prog.  */
		  signal = start_inferior (&argv[2], &status);
		  goto restart;
		  break;
		}
	      else
		{
		  fprintf (stderr, "GDBserver exiting\n");
		  exit (0);
		}
	    }
	}

      /* We come here when getpkt fails.

         For the extended remote protocol we exit (and this is the only
         way we gracefully exit!).

         For the traditional remote protocol close the connection,
         and re-open it at the top of the loop.  */
    detach_inferior ();
    remote_close ();
    if (extended_protocol)
	  exit (0);
    else
	  fprintf (stderr, "Remote side has terminated connection.  "
			   "GDBserver will reopen the connection.\n");
    sigaction(SIGINT, &old_sigaction, NULL);
    }
}