nptl_db/td_thr_tls_get_addr.c

   1 /* Get address of thread local variable.
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21
  22 #include "link.h"
  23 #include "thread_dbP.h"
  24
  25 /* Value used for dtv entries for which the allocation is delayed.  */
  26 # define TLS_DTV_UNALLOCATED    ((void *) -1l)
  27
  28
  29 td_err_e
  30 td_thr_tls_get_addr (const td_thrhandle_t *th __attribute__ ((unused)),
  31                      void *map_address __attribute__ ((unused)),
  32                      size_t offset __attribute__ ((unused)),
  33                      void **address __attribute__ ((unused)))
  34 {
  35 #if USE_TLS
  36   size_t modid;
  37   union dtv pdtv, *dtvp;
  38
  39   LOG ("td_thr_tls_get_addr");
  40
  41   /* Get the DTV pointer from the thread descriptor.  */
  42   if (ps_pdread (th->th_ta_p->ph,
  43                  &((struct pthread *) th->th_unique)->header.data.dtvp,
  44                  &dtvp, sizeof dtvp) != PS_OK)
  45     return TD_ERR;      /* XXX Other error value?  */
  46
  47   /* Read the module ID from the link_map.  */
  48   if (ps_pdread (th->th_ta_p->ph,
  49                  &((struct link_map *) map_address)->l_tls_modid,
  50                  &modid, sizeof modid) != PS_OK)
  51     return TD_ERR;      /* XXX Other error value?  */
  52
  53   /* Get the corresponding entry in the DTV.  */
  54   if (ps_pdread (th->th_ta_p->ph, dtvp + modid,
  55                  &pdtv, sizeof (union dtv)) != PS_OK)
  56     return TD_ERR;      /* XXX Other error value?  */
  57
  58   /* It could be that the memory for this module is not allocated for
  59      the given thread.  */
  60   if (pdtv.pointer == TLS_DTV_UNALLOCATED)
  61     /* There is not much we can do.  */
  62     return TD_NOTALLOC;
  63
  64   *address = (char *) pdtv.pointer + offset;
  65
  66   return TD_OK;
  67 #else
  68   return TD_ERR;
  69 #endif
  70 }