int
linux_mntns_open_cloexec (pid_t pid, const char *filename,
			  int flags, mode_t mode)
{
  enum mnsh_fs_code access = linux_mntns_access_fs (pid);
  struct linux_mnsh *helper;
  int fd, error;
  ssize_t size;

  if (access == MNSH_FS_ERROR)
    return -1;

  if (access == MNSH_FS_DIRECT)
    return gdb_open_cloexec (filename, flags, mode);

  gdb_assert (access == MNSH_FS_HELPER);

  helper = linux_mntns_get_helper ();

  size = mnsh_send_open (helper, filename, flags, mode);
  if (size < 0)
    return -1;

  if (mnsh_recv_fd (helper, &fd, &error) != 0)
    return -1;

  if (fd < 0)
    errno = error;

  return fd;
}
Beispiel #2
0
static enum target_xfer_status
procfs_xfer_auxv (gdb_byte *readbuf,
		  const gdb_byte *writebuf,
		  ULONGEST offset,
		  ULONGEST len,
		  ULONGEST *xfered_len)
{
  int fd;
  ssize_t l;

  std::string pathname = string_printf ("/proc/%d/auxv", inferior_ptid.pid ());
  fd = gdb_open_cloexec (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY, 0);
  if (fd < 0)
    return TARGET_XFER_E_IO;

  if (offset != (ULONGEST) 0
      && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
    l = -1;
  else if (readbuf != NULL)
    l = read (fd, readbuf, (size_t) len);
  else
    l = write (fd, writebuf, (size_t) len);

  (void) close (fd);

  if (l < 0)
    return TARGET_XFER_E_IO;
  else if (l == 0)
    return TARGET_XFER_EOF;
  else
    {
      *xfered_len = (ULONGEST) l;
      return TARGET_XFER_OK;
    }
}
static ssize_t
mnsh_handle_open (int sock, const char *filename,
		  int flags, mode_t mode)
{
  int fd = gdb_open_cloexec (filename, flags, mode);
  ssize_t result = mnsh_return_fd (sock, fd, errno);

  if (fd >= 0)
    close (fd);

  return result;
}
Beispiel #4
0
/* Open FILENAME on the target, using FLAGS and MODE.  Return a
   target file descriptor, or -1 if an error occurs (and set
   *TARGET_ERRNO).  */
static int
inf_child_fileio_open (const char *filename, int flags, int mode,
		       int *target_errno)
{
  int nat_flags;
  int fd;

  if (inf_child_fileio_open_flags_to_host (flags, &nat_flags) == -1)
    {
      *target_errno = FILEIO_EINVAL;
      return -1;
    }

  /* We do not need to convert MODE, since the fileio protocol uses
     the standard values.  */
  fd = gdb_open_cloexec (filename, nat_flags, mode);
  if (fd == -1)
    *target_errno = inf_child_errno_to_fileio_error (errno);

  return fd;
}
Beispiel #5
0
static int
inf_child_fileio_open (struct target_ops *self,
		       struct inferior *inf, const char *filename,
		       int flags, int mode, int warn_if_slow,
		       int *target_errno)
{
  int nat_flags;
  mode_t nat_mode;
  int fd;

  if (fileio_to_host_openflags (flags, &nat_flags) == -1
      || fileio_to_host_mode (mode, &nat_mode) == -1)
    {
      *target_errno = FILEIO_EINVAL;
      return -1;
    }

  fd = gdb_open_cloexec (filename, nat_flags, nat_mode);
  if (fd == -1)
    *target_errno = host_to_fileio_error (errno);

  return fd;
}
static void
tfile_open (const char *arg, int from_tty)
{
  char *temp;
  struct cleanup *old_chain;
  int flags;
  int scratch_chan;
  char header[TRACE_HEADER_SIZE];
  char linebuf[1000]; /* Should be max remote packet size or so.  */
  gdb_byte byte;
  int bytes, i;
  struct trace_status *ts;
  struct uploaded_tp *uploaded_tps = NULL;
  struct uploaded_tsv *uploaded_tsvs = NULL;
  char *filename;

  target_preopen (from_tty);
  if (!arg)
    error (_("No trace file specified."));

  filename = tilde_expand (arg);
  if (!IS_ABSOLUTE_PATH(filename))
    {
      temp = concat (current_directory, "/", filename, (char *) NULL);
      xfree (filename);
      filename = temp;
    }

  old_chain = make_cleanup (xfree, filename);

  flags = O_BINARY | O_LARGEFILE;
  flags |= O_RDONLY;
  scratch_chan = gdb_open_cloexec (filename, flags, 0);
  if (scratch_chan < 0)
    perror_with_name (filename);

  /* Looks semi-reasonable.  Toss the old trace file and work on the new.  */

  discard_cleanups (old_chain);	/* Don't free filename any more.  */
  unpush_target (&tfile_ops);

  trace_filename = xstrdup (filename);
  trace_fd = scratch_chan;

  /* Make sure this is clear.  */
  buffer_free (&trace_tdesc);

  bytes = 0;
  /* Read the file header and test for validity.  */
  tfile_read ((gdb_byte *) &header, TRACE_HEADER_SIZE);

  bytes += TRACE_HEADER_SIZE;
  if (!(header[0] == 0x7f
	&& (startswith (header + 1, "TRACE0\n"))))
    error (_("File is not a valid trace file."));

  push_target (&tfile_ops);

  trace_regblock_size = 0;
  ts = current_trace_status ();
  /* We know we're working with a file.  Record its name.  */
  ts->filename = trace_filename;
  /* Set defaults in case there is no status line.  */
  ts->running_known = 0;
  ts->stop_reason = trace_stop_reason_unknown;
  ts->traceframe_count = -1;
  ts->buffer_free = 0;
  ts->disconnected_tracing = 0;
  ts->circular_buffer = 0;

  TRY
    {
      /* Read through a section of newline-terminated lines that
	 define things like tracepoints.  */
      i = 0;
      while (1)
	{
	  tfile_read (&byte, 1);

	  ++bytes;
	  if (byte == '\n')
	    {
	      /* Empty line marks end of the definition section.  */
	      if (i == 0)
		break;
	      linebuf[i] = '\0';
	      i = 0;
	      tfile_interp_line (linebuf, &uploaded_tps, &uploaded_tsvs);
	    }
	  else
	    linebuf[i++] = byte;
	  if (i >= 1000)
	    error (_("Excessively long lines in trace file"));
	}

      /* By now, tdesc lines have been read from tfile - let's parse them.  */
      target_find_description ();

      /* Record the starting offset of the binary trace data.  */
      trace_frames_offset = bytes;

      /* If we don't have a blocksize, we can't interpret the
	 traceframes.  */
      if (trace_regblock_size == 0)
	error (_("No register block size recorded in trace file"));
    }
  CATCH (ex, RETURN_MASK_ALL)
    {
      /* Remove the partially set up target.  */
      unpush_target (&tfile_ops);
      throw_exception (ex);
    }
static enum mnsh_fs_code
linux_mntns_access_fs (pid_t pid)
{
  struct cleanup *old_chain;
  struct linux_ns *ns;
  struct stat sb;
  struct linux_mnsh *helper;
  ssize_t size;
  int fd, saved_errno;

  if (pid == getpid ())
    return MNSH_FS_DIRECT;

  ns = linux_ns_get_namespace (LINUX_NS_MNT);
  if (ns == NULL)
    return MNSH_FS_DIRECT;

  old_chain = make_cleanup (null_cleanup, NULL);

  fd = gdb_open_cloexec (linux_ns_filename (ns, pid), O_RDONLY, 0);
  if (fd < 0)
    goto error;

  old_chain = make_cleanup_close (fd);

  if (fstat (fd, &sb) != 0)
    goto error;

  if (sb.st_ino == ns->id)
    {
      do_cleanups (old_chain);

      return MNSH_FS_DIRECT;
    }

  helper = linux_mntns_get_helper ();
  if (helper == NULL)
    goto error;

  if (sb.st_ino != helper->nsid)
    {
      int result, error;

      size = mnsh_send_setns (helper, fd, 0);
      if (size < 0)
	goto error;

      if (mnsh_recv_int (helper, &result, &error) != 0)
	goto error;

      if (result != 0)
	{
	  /* ENOSYS indicates that an entire function is unsupported
	     (it's not appropriate for our versions of open/unlink/
	     readlink to sometimes return with ENOSYS depending on how
	     they're called) so we convert ENOSYS to ENOTSUP if setns
	     fails.  */
	  if (error == ENOSYS)
	    error = ENOTSUP;

	  errno = error;
	  goto error;
	}

      helper->nsid = sb.st_ino;
    }

  do_cleanups (old_chain);

  return MNSH_FS_HELPER;

error:
  saved_errno = errno;

  do_cleanups (old_chain);

  errno = saved_errno;
  return MNSH_FS_ERROR;
}
Beispiel #8
0
static void
remote_fileio_func_open (char *buf)
{
  CORE_ADDR ptrval;
  int length;
  long num;
  int flags, fd;
  mode_t mode;
  char *pathname;
  struct stat st;

  /* 1. Parameter: Ptr to pathname / length incl. trailing zero.  */
  if (remote_fileio_extract_ptr_w_len (&buf, &ptrval, &length))
    {
      remote_fileio_ioerror ();
      return;
    }
  /* 2. Parameter: open flags */
  if (remote_fileio_extract_int (&buf, &num))
    {
      remote_fileio_ioerror ();
      return;
    }
  flags = remote_fileio_oflags_to_host (num);
  /* 3. Parameter: open mode */
  if (remote_fileio_extract_int (&buf, &num))
    {
      remote_fileio_ioerror ();
      return;
    }
  mode = remote_fileio_mode_to_host (num, 1);

  /* Request pathname.  */
  pathname = alloca (length);
  if (target_read_memory (ptrval, (gdb_byte *) pathname, length) != 0)
    {
      remote_fileio_ioerror ();
      return;
    }

  /* Check if pathname exists and is not a regular file or directory.  If so,
     return an appropriate error code.  Same for trying to open directories
     for writing.  */
  if (!stat (pathname, &st))
    {
      if (!S_ISREG (st.st_mode) && !S_ISDIR (st.st_mode))
	{
	  remote_fileio_reply (-1, FILEIO_ENODEV);
	  return;
	}
      if (S_ISDIR (st.st_mode)
	  && ((flags & O_WRONLY) == O_WRONLY || (flags & O_RDWR) == O_RDWR))
	{
	  remote_fileio_reply (-1, FILEIO_EISDIR);
	  return;
	}
    }

  remote_fio_no_longjmp = 1;
  fd = gdb_open_cloexec (pathname, flags, mode);
  if (fd < 0)
    {
      remote_fileio_return_errno (-1);
      return;
    }

  fd = remote_fileio_fd_to_targetfd (fd);
  remote_fileio_return_success (fd);
}
Beispiel #9
0
static void
core_open (const char *arg, int from_tty)
{
  const char *p;
  int siggy;
  struct cleanup *old_chain;
  char *temp;
  int scratch_chan;
  int flags;
  char *filename;

  target_preopen (from_tty);
  if (!arg)
    {
      if (core_bfd)
	error (_("No core file specified.  (Use `detach' "
		 "to stop debugging a core file.)"));
      else
	error (_("No core file specified."));
    }

  filename = tilde_expand (arg);
  if (!IS_ABSOLUTE_PATH (filename))
    {
      temp = concat (current_directory, "/",
		     filename, (char *) NULL);
      xfree (filename);
      filename = temp;
    }

  old_chain = make_cleanup (xfree, filename);

  flags = O_BINARY | O_LARGEFILE;
  if (write_files)
    flags |= O_RDWR;
  else
    flags |= O_RDONLY;
  scratch_chan = gdb_open_cloexec (filename, flags, 0);
  if (scratch_chan < 0)
    perror_with_name (filename);

  gdb_bfd_ref_ptr temp_bfd (gdb_bfd_fopen (filename, gnutarget,
					   write_files ? FOPEN_RUB : FOPEN_RB,
					   scratch_chan));
  if (temp_bfd == NULL)
    perror_with_name (filename);

  if (!bfd_check_format (temp_bfd.get (), bfd_core)
      && !gdb_check_format (temp_bfd.get ()))
    {
      /* Do it after the err msg */
      /* FIXME: should be checking for errors from bfd_close (for one
         thing, on error it does not free all the storage associated
         with the bfd).  */
      error (_("\"%s\" is not a core dump: %s"),
	     filename, bfd_errmsg (bfd_get_error ()));
    }

  /* Looks semi-reasonable.  Toss the old core file and work on the
     new.  */

  do_cleanups (old_chain);
  unpush_target (&core_ops);
  core_bfd = temp_bfd.release ();
  old_chain = make_cleanup (core_close_cleanup, 0 /*ignore*/);

  core_gdbarch = gdbarch_from_bfd (core_bfd);

  /* Find a suitable core file handler to munch on core_bfd */
  core_vec = sniff_core_bfd (core_bfd);

  validate_files ();

  core_data = XCNEW (struct target_section_table);

  /* Find the data section */
  if (build_section_table (core_bfd,
			   &core_data->sections,
			   &core_data->sections_end))
    error (_("\"%s\": Can't find sections: %s"),
	   bfd_get_filename (core_bfd), bfd_errmsg (bfd_get_error ()));

  /* If we have no exec file, try to set the architecture from the
     core file.  We don't do this unconditionally since an exec file
     typically contains more information that helps us determine the
     architecture than a core file.  */
  if (!exec_bfd)
    set_gdbarch_from_file (core_bfd);

  push_target (&core_ops);
  discard_cleanups (old_chain);

  /* Do this before acknowledging the inferior, so if
     post_create_inferior throws (can happen easilly if you're loading
     a core file with the wrong exec), we aren't left with threads
     from the previous inferior.  */
  init_thread_list ();

  inferior_ptid = null_ptid;

  /* Need to flush the register cache (and the frame cache) from a
     previous debug session.  If inferior_ptid ends up the same as the
     last debug session --- e.g., b foo; run; gcore core1; step; gcore
     core2; core core1; core core2 --- then there's potential for
     get_current_regcache to return the cached regcache of the
     previous session, and the frame cache being stale.  */
  registers_changed ();

  /* Build up thread list from BFD sections, and possibly set the
     current thread to the .reg/NN section matching the .reg
     section.  */
  bfd_map_over_sections (core_bfd, add_to_thread_list,
			 bfd_get_section_by_name (core_bfd, ".reg"));

  if (ptid_equal (inferior_ptid, null_ptid))
    {
      /* Either we found no .reg/NN section, and hence we have a
	 non-threaded core (single-threaded, from gdb's perspective),
	 or for some reason add_to_thread_list couldn't determine
	 which was the "main" thread.  The latter case shouldn't
	 usually happen, but we're dealing with input here, which can
	 always be broken in different ways.  */
      struct thread_info *thread = first_thread_of_process (-1);

      if (thread == NULL)
	{
	  inferior_appeared (current_inferior (), CORELOW_PID);
	  inferior_ptid = pid_to_ptid (CORELOW_PID);
	  add_thread_silent (inferior_ptid);
	}
      else
	switch_to_thread (thread->ptid);
    }

  post_create_inferior (&core_ops, from_tty);

  /* Now go through the target stack looking for threads since there
     may be a thread_stratum target loaded on top of target core by
     now.  The layer above should claim threads found in the BFD
     sections.  */
  TRY
    {
      target_update_thread_list ();
    }

  CATCH (except, RETURN_MASK_ERROR)
    {
      exception_print (gdb_stderr, except);
    }
Beispiel #10
0
static void
core_open (char *filename, int from_tty)
{
  const char *p;
  int siggy;
  struct cleanup *old_chain;
  char *temp;
  bfd *temp_bfd;
  int scratch_chan;
  int flags;
  volatile struct gdb_exception except;

  target_preopen (from_tty);
  if (!filename)
    {
      if (core_bfd)
	error (_("No core file specified.  (Use `detach' "
		 "to stop debugging a core file.)"));
      else
	error (_("No core file specified."));
    }

  filename = tilde_expand (filename);
  if (!IS_ABSOLUTE_PATH (filename))
    {
      temp = concat (current_directory, "/",
		     filename, (char *) NULL);
      xfree (filename);
      filename = temp;
    }

  old_chain = make_cleanup (xfree, filename);

  flags = O_BINARY | O_LARGEFILE;
  if (write_files)
    flags |= O_RDWR;
  else
    flags |= O_RDONLY;
  scratch_chan = gdb_open_cloexec (filename, flags, 0);
  if (scratch_chan < 0)
    perror_with_name (filename);

  temp_bfd = gdb_bfd_fopen (filename, gnutarget, 
			    write_files ? FOPEN_RUB : FOPEN_RB,
			    scratch_chan);
  if (temp_bfd == NULL)
    perror_with_name (filename);

  if (!bfd_check_format (temp_bfd, bfd_core)
      && !gdb_check_format (temp_bfd))
    {
      /* Do it after the err msg */
      /* FIXME: should be checking for errors from bfd_close (for one
         thing, on error it does not free all the storage associated
         with the bfd).  */
      make_cleanup_bfd_unref (temp_bfd);
      error (_("\"%s\" is not a core dump: %s"),
	     filename, bfd_errmsg (bfd_get_error ()));
    }

  /* Looks semi-reasonable.  Toss the old core file and work on the
     new.  */

  do_cleanups (old_chain);
  unpush_target (&core_ops);
  core_bfd = temp_bfd;
  old_chain = make_cleanup (core_close_cleanup, 0 /*ignore*/);

  core_gdbarch = gdbarch_from_bfd (core_bfd);

  /* Find a suitable core file handler to munch on core_bfd */
  core_vec = sniff_core_bfd (core_bfd);

  validate_files ();

  core_data = XZALLOC (struct target_section_table);

  /* Find the data section */
  if (build_section_table (core_bfd,
			   &core_data->sections,
			   &core_data->sections_end))
    error (_("\"%s\": Can't find sections: %s"),
	   bfd_get_filename (core_bfd), bfd_errmsg (bfd_get_error ()));

  /* If we have no exec file, try to set the architecture from the
     core file.  We don't do this unconditionally since an exec file
     typically contains more information that helps us determine the
     architecture than a core file.  */
  if (!exec_bfd)
    set_gdbarch_from_file (core_bfd);

  push_target (&core_ops);
  discard_cleanups (old_chain);

  /* Do this before acknowledging the inferior, so if
     post_create_inferior throws (can happen easilly if you're loading
     a core file with the wrong exec), we aren't left with threads
     from the previous inferior.  */
  init_thread_list ();

  inferior_ptid = null_ptid;

  /* Need to flush the register cache (and the frame cache) from a
     previous debug session.  If inferior_ptid ends up the same as the
     last debug session --- e.g., b foo; run; gcore core1; step; gcore
     core2; core core1; core core2 --- then there's potential for
     get_current_regcache to return the cached regcache of the
     previous session, and the frame cache being stale.  */
  registers_changed ();

  /* Build up thread list from BFD sections, and possibly set the
     current thread to the .reg/NN section matching the .reg
     section.  */
  bfd_map_over_sections (core_bfd, add_to_thread_list,
			 bfd_get_section_by_name (core_bfd, ".reg"));

  if (ptid_equal (inferior_ptid, null_ptid))
    {
      /* Either we found no .reg/NN section, and hence we have a
	 non-threaded core (single-threaded, from gdb's perspective),
	 or for some reason add_to_thread_list couldn't determine
	 which was the "main" thread.  The latter case shouldn't
	 usually happen, but we're dealing with input here, which can
	 always be broken in different ways.  */
      struct thread_info *thread = first_thread_of_process (-1);

      if (thread == NULL)
	{
	  inferior_appeared (current_inferior (), CORELOW_PID);
	  inferior_ptid = pid_to_ptid (CORELOW_PID);
	  add_thread_silent (inferior_ptid);
	}
      else
	switch_to_thread (thread->ptid);
    }

  post_create_inferior (&core_ops, from_tty);

  /* Now go through the target stack looking for threads since there
     may be a thread_stratum target loaded on top of target core by
     now.  The layer above should claim threads found in the BFD
     sections.  */
  TRY_CATCH (except, RETURN_MASK_ERROR)
    {
      target_find_new_threads ();
    }

  if (except.reason < 0)
    exception_print (gdb_stderr, except);

  p = bfd_core_file_failing_command (core_bfd);
  if (p)
    printf_filtered (_("Core was generated by `%s'.\n"), p);

  /* Clearing any previous state of convenience variables.  */
  clear_exit_convenience_vars ();

  siggy = bfd_core_file_failing_signal (core_bfd);
  if (siggy > 0)
    {
      /* If we don't have a CORE_GDBARCH to work with, assume a native
	 core (map gdb_signal from host signals).  If we do have
	 CORE_GDBARCH to work with, but no gdb_signal_from_target
	 implementation for that gdbarch, as a fallback measure,
	 assume the host signal mapping.  It'll be correct for native
	 cores, but most likely incorrect for cross-cores.  */
      enum gdb_signal sig = (core_gdbarch != NULL
			     && gdbarch_gdb_signal_from_target_p (core_gdbarch)
			     ? gdbarch_gdb_signal_from_target (core_gdbarch,
							       siggy)
			     : gdb_signal_from_host (siggy));

      printf_filtered (_("Program terminated with signal %s, %s.\n"),
		       gdb_signal_to_name (sig), gdb_signal_to_string (sig));

      /* Set the value of the internal variable $_exitsignal,
	 which holds the signal uncaught by the inferior.  */
      set_internalvar_integer (lookup_internalvar ("_exitsignal"),
			       siggy);
    }

  /* Fetch all registers from core file.  */
  target_fetch_registers (get_current_regcache (), -1);

  /* Now, set up the frame cache, and print the top of stack.  */
  reinit_frame_cache ();
  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
}
Beispiel #11
0
void
core_target_open (const char *arg, int from_tty)
{
  const char *p;
  int siggy;
  int scratch_chan;
  int flags;

  target_preopen (from_tty);
  if (!arg)
    {
      if (core_bfd)
	error (_("No core file specified.  (Use `detach' "
		 "to stop debugging a core file.)"));
      else
	error (_("No core file specified."));
    }

  gdb::unique_xmalloc_ptr<char> filename (tilde_expand (arg));
  if (!IS_ABSOLUTE_PATH (filename.get ()))
    filename.reset (concat (current_directory, "/",
			    filename.get (), (char *) NULL));

  flags = O_BINARY | O_LARGEFILE;
  if (write_files)
    flags |= O_RDWR;
  else
    flags |= O_RDONLY;
  scratch_chan = gdb_open_cloexec (filename.get (), flags, 0);
  if (scratch_chan < 0)
    perror_with_name (filename.get ());

  gdb_bfd_ref_ptr temp_bfd (gdb_bfd_fopen (filename.get (), gnutarget,
					   write_files ? FOPEN_RUB : FOPEN_RB,
					   scratch_chan));
  if (temp_bfd == NULL)
    perror_with_name (filename.get ());

  if (!bfd_check_format (temp_bfd.get (), bfd_core)
      && !gdb_check_format (temp_bfd.get ()))
    {
      /* Do it after the err msg */
      /* FIXME: should be checking for errors from bfd_close (for one
         thing, on error it does not free all the storage associated
         with the bfd).  */
      error (_("\"%s\" is not a core dump: %s"),
	     filename.get (), bfd_errmsg (bfd_get_error ()));
    }

  current_program_space->cbfd = std::move (temp_bfd);

  core_target *target = new core_target ();

  /* Own the target until it is successfully pushed.  */
  target_ops_up target_holder (target);

  validate_files ();

  /* If we have no exec file, try to set the architecture from the
     core file.  We don't do this unconditionally since an exec file
     typically contains more information that helps us determine the
     architecture than a core file.  */
  if (!exec_bfd)
    set_gdbarch_from_file (core_bfd);

  push_target (std::move (target_holder));

  inferior_ptid = null_ptid;

  /* Need to flush the register cache (and the frame cache) from a
     previous debug session.  If inferior_ptid ends up the same as the
     last debug session --- e.g., b foo; run; gcore core1; step; gcore
     core2; core core1; core core2 --- then there's potential for
     get_current_regcache to return the cached regcache of the
     previous session, and the frame cache being stale.  */
  registers_changed ();

  /* Build up thread list from BFD sections, and possibly set the
     current thread to the .reg/NN section matching the .reg
     section.  */
  bfd_map_over_sections (core_bfd, add_to_thread_list,
			 bfd_get_section_by_name (core_bfd, ".reg"));

  if (inferior_ptid == null_ptid)
    {
      /* Either we found no .reg/NN section, and hence we have a
	 non-threaded core (single-threaded, from gdb's perspective),
	 or for some reason add_to_thread_list couldn't determine
	 which was the "main" thread.  The latter case shouldn't
	 usually happen, but we're dealing with input here, which can
	 always be broken in different ways.  */
      thread_info *thread = first_thread_of_inferior (current_inferior ());

      if (thread == NULL)
	{
	  inferior_appeared (current_inferior (), CORELOW_PID);
	  inferior_ptid = ptid_t (CORELOW_PID);
	  add_thread_silent (inferior_ptid);
	}
      else
	switch_to_thread (thread);
    }

  post_create_inferior (target, from_tty);

  /* Now go through the target stack looking for threads since there
     may be a thread_stratum target loaded on top of target core by
     now.  The layer above should claim threads found in the BFD
     sections.  */
  try
    {
      target_update_thread_list ();
    }

  catch (const gdb_exception_error &except)
    {
      exception_print (gdb_stderr, except);
    }

  p = bfd_core_file_failing_command (core_bfd);
  if (p)
    printf_filtered (_("Core was generated by `%s'.\n"), p);

  /* Clearing any previous state of convenience variables.  */
  clear_exit_convenience_vars ();

  siggy = bfd_core_file_failing_signal (core_bfd);
  if (siggy > 0)
    {
      gdbarch *core_gdbarch = target->core_gdbarch ();

      /* If we don't have a CORE_GDBARCH to work with, assume a native
	 core (map gdb_signal from host signals).  If we do have
	 CORE_GDBARCH to work with, but no gdb_signal_from_target
	 implementation for that gdbarch, as a fallback measure,
	 assume the host signal mapping.  It'll be correct for native
	 cores, but most likely incorrect for cross-cores.  */
      enum gdb_signal sig = (core_gdbarch != NULL
			     && gdbarch_gdb_signal_from_target_p (core_gdbarch)
			     ? gdbarch_gdb_signal_from_target (core_gdbarch,
							       siggy)
			     : gdb_signal_from_host (siggy));

      printf_filtered (_("Program terminated with signal %s, %s.\n"),
		       gdb_signal_to_name (sig), gdb_signal_to_string (sig));

      /* Set the value of the internal variable $_exitsignal,
	 which holds the signal uncaught by the inferior.  */
      set_internalvar_integer (lookup_internalvar ("_exitsignal"),
			       siggy);
    }

  /* Fetch all registers from core file.  */
  target_fetch_registers (get_current_regcache (), -1);

  /* Now, set up the frame cache, and print the top of stack.  */
  reinit_frame_cache ();
  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);

  /* Current thread should be NUM 1 but the user does not know that.
     If a program is single threaded gdb in general does not mention
     anything about threads.  That is why the test is >= 2.  */
  if (thread_count () >= 2)
    {
      try
	{
	  thread_command (NULL, from_tty);
	}
      catch (const gdb_exception_error &except)
	{
	  exception_print (gdb_stderr, except);
	}
    }
}