sysdeps/unix/sysv/linux/s390/s390-32/pointer_guard.h

   1 /* Pointer obfuscation implenentation.  s390 version.
   2    Copyright (C) 2005-2023 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 #ifndef POINTER_GUARD_H
  20 #define POINTER_GUARD_H
  21
  22 #if IS_IN (rtld)
  23 /* We cannot use the thread descriptor because in ld.so we use setjmp
  24    earlier than the descriptor is initialized.  */
  25 # include <sysdeps/generic/pointer_guard.h>
  26 #else
  27 /* For the time being just use stack_guard rather than a separate
  28    pointer_guard.  */
  29 # ifdef __ASSEMBLER__
  30 #  define PTR_MANGLE(reg, tmpreg) \
  31   ear     tmpreg,%a0;                   \
  32   x       reg,STACK_GUARD(tmpreg)
  33 #  define PTR_MANGLE2(reg, tmpreg) \
  34   x       reg,STACK_GUARD(tmpreg)
  35 #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
  36 # else
  37 #  include <stdint.h>
  38 #  include <tls.h>
  39 #  define PTR_MANGLE(var) \
  40   (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
  41 #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
  42 # endif
  43 #endif
  44
  45 #endif /* POINTER_GUARD_H */