elf/tst-tls-surplus.c

   1 /* Test size of the static TLS surplus reservation for backwards compatibility.
   2    Copyright (C) 2020-2021 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <support/check.h>
  21 #include <support/xdlfcn.h>
  22
  23 static int do_test (void);
  24 #include <support/test-driver.c>
  25
  26 /* This hack results in a definition of struct rtld_global_ro.  Do
  27    this after all the other header inclusions, to minimize the
  28    impact.  */
  29 #define SHARED
  30 #include <ldsodefs.h>
  31
  32 static
  33 int do_test (void)
  34 {
  35   /* Avoid introducing a copy relocation due to the hidden alias in
  36      ld.so.  */
  37   struct rtld_global_ro *glro = xdlsym (NULL, "_rtld_global_ro");
  38   printf ("info: _dl_tls_static_surplus: %zu\n", glro->_dl_tls_static_surplus);
  39   /* Hisoric value: 16 * 100 + 64.  */
  40   TEST_VERIFY (glro->_dl_tls_static_surplus >= 1664);
  41   return 0;
  42 }