nptl_db/td_thr_tsd.c

   1 /* Get a thread-specific data pointer for a thread.
   2    Copyright (C) 1999-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <stdint.h>
  21 #include "thread_dbP.h"
  22
  23
  24 td_err_e
  25 td_thr_tsd (const td_thrhandle_t *th, const thread_key_t tk, void **data)
  26 {
  27   td_err_e err;
  28   psaddr_t tk_seq, level1, level2, seq, value;
  29   void *copy;
  30   uint32_t pthread_key_2ndlevel_size, idx1st, idx2nd;
  31
  32   LOG ("td_thr_tsd");
  33
  34   /* Get the key entry.  */
  35   err = DB_GET_VALUE (tk_seq, th->th_ta_p, __pthread_keys, tk);
  36   if (err == TD_NOAPLIC)
  37     return TD_BADKEY;
  38   if (err != TD_OK)
  39     return err;
  40
  41   /* Fail if this key is not at all used.  */
  42   if (((uintptr_t) tk_seq & 1) == 0)
  43     return TD_BADKEY;
  44
  45   /* This makes sure we have the size information on hand.  */
  46   err = DB_GET_FIELD_ADDRESS (level2, th->th_ta_p, 0, pthread_key_data_level2,
  47                               data, 1);
  48   if (err != TD_OK)
  49     return err;
  50
  51   /* Compute the indeces.  */
  52   pthread_key_2ndlevel_size
  53     = DB_DESC_NELEM (th->th_ta_p->ta_field_pthread_key_data_level2_data);
  54   idx1st = tk / pthread_key_2ndlevel_size;
  55   idx2nd = tk % pthread_key_2ndlevel_size;
  56
  57   /* Now fetch the first level pointer.  */
  58   err = DB_GET_FIELD (level1, th->th_ta_p, th->th_unique, pthread,
  59                       specific, idx1st);
  60   if (err == TD_NOAPLIC)
  61     return TD_DBERR;
  62   if (err != TD_OK)
  63     return err;
  64
  65   /* Check the pointer to the second level array.  */
  66   if (level1 == 0)
  67     return TD_NOTSD;
  68
  69   /* Locate the element within the second level array.  */
  70   err = DB_GET_FIELD_ADDRESS (level2, th->th_ta_p,
  71                               level1, pthread_key_data_level2, data, idx2nd);
  72   if (err == TD_NOAPLIC)
  73     return TD_DBERR;
  74   if (err != TD_OK)
  75     return err;
  76
  77   /* Now copy in that whole structure.  */
  78   err = DB_GET_STRUCT (copy, th->th_ta_p, level2, pthread_key_data);
  79   if (err != TD_OK)
  80     return err;
  81
  82   /* Check whether the data is valid.  */
  83   err = DB_GET_FIELD_LOCAL (seq, th->th_ta_p, copy, pthread_key_data, seq, 0);
  84   if (err != TD_OK)
  85     return err;
  86   if (seq != tk_seq)
  87     return TD_NOTSD;
  88
  89   /* Finally, fetch the value.  */
  90   err = DB_GET_FIELD_LOCAL (value, th->th_ta_p, copy, pthread_key_data,
  91                             data, 0);
  92   if (err == TD_OK)
  93     *data = value;
  94
  95   return err;
  96 }