/* Pointer guard implementation.  sw_64 version.
   Copyright (C) 2006-2023 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library.  If not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef POINTER_GUARD_H
#define POINTER_GUARD_H

/* Pointer mangling support.  Note that tls access is slow enough that
   we don't deoptimize things by placing the pointer check value there.  */
#ifdef __ASSEMBLER__
#  if IS_IN(rtld)
#    define PTR_MANGLE(dst, src, tmp)                                         \
      ldih tmp, __pointer_chk_guard_local ($29) !gprelhigh;                   \
      ldl tmp, __pointer_chk_guard_local (tmp) !gprellow;                     \
      xor src, tmp, dst
#    define PTR_MANGLE2(dst, src, tmp) xor src, tmp, dst
#  elif defined SHARED
#    define PTR_MANGLE(dst, src, tmp)                                         \
      ldl tmp, __pointer_chk_guard;                                           \
      xor src, tmp, dst
#  else
#    define PTR_MANGLE(dst, src, tmp)                                         \
      ldl tmp, __pointer_chk_guard_local;                                     \
      xor src, tmp, dst
#  endif
#  define PTR_MANGLE2(dst, src, tmp) xor src, tmp, dst
#  define PTR_DEMANGLE(dst, tmp) PTR_MANGLE (dst, dst, tmp)
#  define PTR_DEMANGLE2(dst, tmp) PTR_MANGLE2 (dst, dst, tmp)
#else
#  include <stdint.h>
#  if (IS_IN(rtld) || (!defined SHARED && (IS_IN(libc) || IS_IN(libpthread))))
extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
#    define PTR_MANGLE(var)                                                   \
      (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard_local)
#  else
extern uintptr_t __pointer_chk_guard attribute_relro;
#    define PTR_MANGLE(var)                                                   \
      (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard)
#  endif
#  define PTR_DEMANGLE(var) PTR_MANGLE (var)
#endif /* ASSEMBLER */

#endif /* POINTER_GUARD_H */
