glibc/sysdeps/unix/sysv/linux/loongarch/pointer_guard.h

/* Pointer obfuscation implenentation.  LoongArch version.
   Copyright (C) 2022-2023 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

/* Load a got-relative EXPR into G, using T.
   Note G and T are register names.  */
#define LD_GLOBAL(G, EXPR) \
  la.global G,  EXPR; \
  REG_L     G,  G,  0;

/* Load a pc-relative EXPR into G, using T.
   Note G and T are register names.  */
#define LD_PCREL(G, EXPR) \
  la.pcrel  G,  EXPR; \
  REG_L     G,  G,  0;

#if (IS_IN (rtld) \
     || (!defined SHARED && (IS_IN (libc) \
     || IS_IN (libpthread))))

#ifdef __ASSEMBLER__
#define PTR_MANGLE(dst, src, guard) \
  LD_PCREL (guard, __pointer_chk_guard_local); \
  PTR_MANGLE2 (dst, src, guard);
#define PTR_DEMANGLE(dst, src, guard) \
  LD_PCREL (guard, __pointer_chk_guard_local); \
  PTR_DEMANGLE2 (dst, src, guard);
/* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
#define PTR_MANGLE2(dst, src, guard) \
  xor  dst, src, guard;
#define PTR_DEMANGLE2(dst, src, guard) \
  PTR_MANGLE2 (dst, src, guard);
#else
# include <stdint.h>
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)
#define PTR_DEMANGLE(var) PTR_MANGLE (var)
#endif

#else

#ifdef __ASSEMBLER__
#define PTR_MANGLE(dst, src, guard) \
  LD_GLOBAL (guard, __pointer_chk_guard); \
  PTR_MANGLE2 (dst, src, guard);
#define PTR_DEMANGLE(dst, src, guard) \
  LD_GLOBAL (guard, __pointer_chk_guard); \
  PTR_DEMANGLE2 (dst, src, guard);
/* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
#define PTR_MANGLE2(dst, src, guard) \
  xor dst, src, guard;
#define PTR_DEMANGLE2(dst, src, guard) \
  PTR_MANGLE2 (dst, src, guard);
#else
# include <stdint.h>
extern uintptr_t __pointer_chk_guard attribute_relro;
#define PTR_MANGLE(var) \
  (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard)
#define PTR_DEMANGLE(var) PTR_MANGLE (var)
#endif

#endif

#endif /* POINTER_GUARD_H */