sysdeps/mach/hurd/errno-loc.c

   1 /* __errno_location -- helper function for locating per-thread errno value
   2    Copyright (C) 2002-2018 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 #if IS_IN (rtld)
  20 /*
  21  * rtld can not access TLS too early, thus rtld_errno.
  22  *
  23  * Instead of making __open/__close pass errno from TLS to rtld_errno, simply
  24  * use a weak __errno_location using rtld_errno, which will be overriden by the
  25  * libc definition.
  26  */
  27 static int rtld_errno;
  28 int * weak_function
  29 __errno_location (void)
  30 {
  31   return &rtld_errno;
  32 }
  33 libc_hidden_weak (__errno_location)
  34 #else
  35 #include "../../../csu/errno-loc.c"
  36 #endif