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 /* rtld can not access TLS too early, thus rtld_errno.
  21
  22    Instead of making __open/__close pass errno from TLS to rtld_errno, simply
  23    use a weak __errno_location using rtld_errno, which will be overriden by the
  24    libc definition.  */
  25 static int rtld_errno;
  26 int * weak_function
  27 __errno_location (void)
  28 {
  29   return &rtld_errno;
  30 }
  31 libc_hidden_weak (__errno_location)
  32 #else
  33 #include "../../../csu/errno-loc.c"
  34 #endif