1  /* Pointer obfuscation implenentation.  PowerpC 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  # ifdef __ASSEMBLER__
      28  #  if defined(__PPC64__) || defined(__powerpc64__)
      29  #   define LOAD  ld
      30  #   define TPREG r13
      31  #  else
      32  #   define LOAD  lwz
      33  #   define TPREG r2
      34  #  endif
      35  #  define PTR_MANGLE(reg, tmpreg) \
      36          LOAD    tmpreg,POINTER_GUARD(TPREG); \
      37          xor     reg,tmpreg,reg
      38  #  define PTR_MANGLE2(reg, tmpreg) \
      39          xor     reg,tmpreg,reg
      40  #  define PTR_MANGLE3(destreg, reg, tmpreg) \
      41          LOAD    tmpreg,POINTER_GUARD(TPREG); \
      42          xor     destreg,tmpreg,reg
      43  #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
      44  #  define PTR_DEMANGLE2(reg, tmpreg) PTR_MANGLE2 (reg, tmpreg)
      45  #  define PTR_DEMANGLE3(destreg, reg, tmpreg) PTR_MANGLE3 (destreg, reg, tmpreg)
      46  # else
      47  #  include <stdint.h>
      48  #  include <tls.h>
      49  #  define PTR_MANGLE(var) \
      50    (var) = (__typeof (var)) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
      51  #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
      52  # endif
      53  #endif
      54  
      55  #endif /* POINTER_GUARD_H */