elf/dl-tsd.c

   1 /* Thread-local data used by error handling for runtime dynamic linker.
   2    Copyright (C) 2002-2015 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifdef _LIBC_REENTRANT
  20
  21 # include <ldsodefs.h>
  22 # include <tls.h>
  23
  24 # ifndef SHARED
  25
  26 /* _dl_error_catch_tsd points to this for the single-threaded case.
  27    It's reset by the thread library for multithreaded programs
  28    if we're not using __thread.  */
  29 void ** __attribute__ ((const))
  30 _dl_initial_error_catch_tsd (void)
  31 {
  32   static __thread void *data;
  33   return &data;
  34 }
  35 void **(*_dl_error_catch_tsd) (void) __attribute__ ((const))
  36      = &_dl_initial_error_catch_tsd;
  37
  38 # else
  39
  40 /* libpthread sets _dl_error_catch_tsd to point to this function.
  41    We define it here instead of in libpthread so that it doesn't
  42    need to have a TLS segment of its own just for this one pointer.  */
  43
  44 void ** __attribute__ ((const))
  45 __libc_dl_error_tsd (void)
  46 {
  47   static __thread void *data attribute_tls_model_ie;
  48   return &data;
  49 }
  50
  51 # endif /* SHARED */
  52
  53 #endif /* _LIBC_REENTRANT */