/* Pointer obfuscation implenentation. i386 version. Copyright (C) 2005-2022 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 . */ #ifndef POINTER_GUARD_H #define POINTER_GUARD_H #include #if IS_IN (rtld) /* We cannot use the thread descriptor because in ld.so we use setjmp earlier than the descriptor is initialized. Using a global variable is too complicated here since we have no PC-relative addressing mode. */ # include #else # ifdef __ASSEMBLER__ # define PTR_MANGLE(reg) xorl %gs:POINTER_GUARD, reg; \ roll $9, reg # define PTR_DEMANGLE(reg) rorl $9, reg; \ xorl %gs:POINTER_GUARD, reg # else # define PTR_MANGLE(var) asm ("xorl %%gs:%c2, %0\n" \ "roll $9, %0" \ : "=r" (var) \ : "0" (var), \ "i" (POINTER_GUARD)) # define PTR_DEMANGLE(var) asm ("rorl $9, %0\n" \ "xorl %%gs:%c2, %0" \ : "=r" (var) \ : "0" (var), \ "i" (POINTER_GUARD)) # endif #endif #endif /* POINTER_GUARD_H */