/* Validate a thread handle.

   Copyright (C) 1999-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include "thread_dbP.h"

#include <stdbool.h>

static td_err_e

check_thread_list (const td_thrhandle_t *th, psaddr_t head, bool *uninit)

{

  td_err_e err;

  psaddr_t next, ofs;

  err = DB_GET_FIELD (next, th->th_ta_p, head, list_t, next, 0);

  if (err == TD_OK)

    {

      if (next == 0)

	{

	  *uninit = true;

	  return TD_NOTHR;

	}

      err = DB_GET_FIELD_ADDRESS (ofs, th->th_ta_p, 0, pthread, list, 0);

    }

  while (err == TD_OK)

    {

      if (next == head)

	return TD_NOTHR;

      if (next - (ofs - (psaddr_t) 0) == th->th_unique)

	return TD_OK;

      err = DB_GET_FIELD (next, th->th_ta_p, next, list_t, next, 0);

    }

  return err;

}

td_err_e

td_thr_validate (const td_thrhandle_t *th)

{

  td_err_e err;

  psaddr_t list;

  LOG ("td_thr_validate");

  /* First check the list with threads using user allocated stacks.  */

  bool uninit = false;

  err = DB_GET_SYMBOL (list, th->th_ta_p, __stack_user);

  if (err == TD_OK)

    err = check_thread_list (th, list, &uninit);

  /* If our thread is not on this list search the list with stack

     using implementation allocated stacks.  */

  if (err == TD_NOTHR)

    {

      err = DB_GET_SYMBOL (list, th->th_ta_p, stack_used);

      if (err == TD_OK)

	err = check_thread_list (th, list, &uninit);

      if (err == TD_NOTHR && uninit && th->th_unique == 0)

	/* __pthread_initialize_minimal has not run yet.

	   There is only the special case thread handle.  */

	err = TD_OK;

    }

  return err;

}