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

   1 /* Pointer obfuscation implenentation.  LoongArch version.
   2    Copyright (C) 2022-2024 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 /* Load a got-relative EXPR into register G.  */
  23 #define LD_GLOBAL(G, EXPR) \
  24   la.global G,  EXPR; \
  25   REG_L     G,  G,  0;
  26
  27 /* Load a pc-relative EXPR into register G.  */
  28 #define LD_PCREL(G, EXPR) \
  29   pcalau12i G, %pc_hi20(EXPR); \
  30   REG_L     G, G, %pc_lo12(EXPR);
  31
  32 #if (IS_IN (rtld) \
  33      || (!defined SHARED && (IS_IN (libc) \
  34      || IS_IN (libpthread))))
  35
  36 #ifdef __ASSEMBLER__
  37 #define PTR_MANGLE(dst, src, guard) \
  38   LD_PCREL (guard, __pointer_chk_guard_local); \
  39   PTR_MANGLE2 (dst, src, guard);
  40 #define PTR_DEMANGLE(dst, src, guard) \
  41   LD_PCREL (guard, __pointer_chk_guard_local); \
  42   PTR_DEMANGLE2 (dst, src, guard);
  43 /* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
  44 #define PTR_MANGLE2(dst, src, guard) \
  45   xor  dst, src, guard;
  46 #define PTR_DEMANGLE2(dst, src, guard) \
  47   PTR_MANGLE2 (dst, src, guard);
  48 #else
  49 # include <stdint.h>
  50 extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
  51 #define PTR_MANGLE(var) \
  52   (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard_local)
  53 #define PTR_DEMANGLE(var) PTR_MANGLE (var)
  54 #endif
  55
  56 #else
  57
  58 #ifdef __ASSEMBLER__
  59 #define PTR_MANGLE(dst, src, guard) \
  60   LD_GLOBAL (guard, __pointer_chk_guard); \
  61   PTR_MANGLE2 (dst, src, guard);
  62 #define PTR_DEMANGLE(dst, src, guard) \
  63   LD_GLOBAL (guard, __pointer_chk_guard); \
  64   PTR_DEMANGLE2 (dst, src, guard);
  65 /* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
  66 #define PTR_MANGLE2(dst, src, guard) \
  67   xor dst, src, guard;
  68 #define PTR_DEMANGLE2(dst, src, guard) \
  69   PTR_MANGLE2 (dst, src, guard);
  70 #else
  71 # include <stdint.h>
  72 extern uintptr_t __pointer_chk_guard attribute_relro;
  73 #define PTR_MANGLE(var) \
  74   (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard)
  75 #define PTR_DEMANGLE(var) PTR_MANGLE (var)
  76 #endif
  77
  78 #endif
  79
  80 #endif /* POINTER_GUARD_H */