1  /* Validate a thread handle.
       2     Copyright (C) 1999-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include "thread_dbP.h"
      20  #include <stdbool.h>
      21  
      22  td_err_e
      23  __td_ta_stack_user (td_thragent_t *ta, psaddr_t *plist)
      24  {
      25    if (__td_ta_rtld_global (ta))
      26      return DB_GET_FIELD_ADDRESS (*plist, ta, ta->ta_addr__rtld_global,
      27  				 rtld_global, _dl_stack_user, 0);
      28    else
      29      {
      30        if (ta->ta_addr__dl_stack_user == 0
      31  	  && td_mod_lookup (ta->ph, NULL, SYM__dl_stack_user,
      32  			    &ta->ta_addr__dl_stack_user) != PS_OK)
      33  	return TD_ERR;
      34        *plist = ta->ta_addr__dl_stack_user;
      35        return TD_OK;
      36      }
      37  }
      38  
      39  td_err_e
      40  __td_ta_stack_used (td_thragent_t *ta, psaddr_t *plist)
      41  {
      42  
      43    if (__td_ta_rtld_global (ta))
      44      return DB_GET_FIELD_ADDRESS (*plist, ta, ta->ta_addr__rtld_global,
      45  				 rtld_global, _dl_stack_used, 0);
      46    else
      47      {
      48        if (ta->ta_addr__dl_stack_used == 0
      49  	  && td_mod_lookup (ta->ph, NULL, SYM__dl_stack_used,
      50  			    &ta->ta_addr__dl_stack_used) != PS_OK)
      51  	return TD_ERR;
      52        *plist = ta->ta_addr__dl_stack_used;
      53        return TD_OK;
      54      }
      55  }
      56  
      57  static td_err_e
      58  check_thread_list (const td_thrhandle_t *th, psaddr_t head, bool *uninit)
      59  {
      60    td_err_e err;
      61    psaddr_t next, ofs;
      62  
      63    err = DB_GET_FIELD (next, th->th_ta_p, head, list_t, next, 0);
      64    if (err == TD_OK)
      65      {
      66        if (next == 0)
      67  	{
      68  	  *uninit = true;
      69  	  return TD_NOTHR;
      70  	}
      71        err = DB_GET_FIELD_ADDRESS (ofs, th->th_ta_p, 0, pthread, list, 0);
      72      }
      73  
      74    while (err == TD_OK)
      75      {
      76        if (next == head)
      77  	return TD_NOTHR;
      78  
      79        if (next - (ofs - (psaddr_t) 0) == th->th_unique)
      80  	return TD_OK;
      81  
      82        err = DB_GET_FIELD (next, th->th_ta_p, next, list_t, next, 0);
      83      }
      84  
      85    return err;
      86  }
      87  
      88  
      89  td_err_e
      90  td_thr_validate (const td_thrhandle_t *th)
      91  {
      92    td_err_e err;
      93    psaddr_t list;
      94  
      95    LOG ("td_thr_validate");
      96  
      97    /* First check the list with threads using user allocated stacks.  */
      98    bool uninit = false;
      99    err = __td_ta_stack_user (th->th_ta_p, &list);
     100    if (err == TD_OK)
     101      err = check_thread_list (th, list, &uninit);
     102  
     103    /* If our thread is not on this list search the list with stack
     104       using implementation allocated stacks.  */
     105    if (err == TD_NOTHR)
     106      {
     107        err = __td_ta_stack_used (th->th_ta_p, &list);
     108        if (err == TD_OK)
     109  	err = check_thread_list (th, list, &uninit);
     110  
     111        if (err == TD_NOTHR && uninit && th->th_unique == 0)
     112  	/* __pthread_initialize_minimal has not run yet.
     113  	   There is only the special case thread handle.  */
     114  	err = TD_OK;
     115      }
     116  
     117    return err;
     118  }