sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h

   1 /* System-specific settings for dynamic linker code.  IA-64 version.
   2    Copyright (C) 2003, 2004, 2006, 2008 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _DL_SYSDEP_H
  20 #define _DL_SYSDEP_H    1
  21
  22 /* This macro must be defined to either 0 or 1.
  23
  24    If 1, then an errno global variable hidden in ld.so will work right with
  25    all the errno-using libc code compiled for ld.so, and there is never a
  26    need to share the errno location with libc.  This is appropriate only if
  27    all the libc functions that ld.so uses are called without PLT and always
  28    get the versions linked into ld.so rather than the libc ones.  */
  29
  30 #ifdef IS_IN_rtld
  31 # define RTLD_PRIVATE_ERRNO 1
  32 #else
  33 # define RTLD_PRIVATE_ERRNO 0
  34 #endif
  35
  36 /* Traditionally system calls have been made using break 0x100000.  A
  37    second method was introduced which, if possible, will use the EPC
  38    instruction.  To signal the presence and where to find the code the
  39    kernel passes an AT_SYSINFO_EHDR pointer in the auxiliary vector to
  40    the application.  */
  41 #define NEED_DL_SYSINFO 1
  42 #define USE_DL_SYSINFO  1
  43
  44 #if defined NEED_DL_SYSINFO && !defined __ASSEMBLER__
  45 /* Don't declare this as a function---we want it's entry-point, not
  46    it's function descriptor... */
  47 extern int _dl_sysinfo_break attribute_hidden;
  48 # define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
  49 # define DL_SYSINFO_IMPLEMENTATION              \
  50   asm (".text\n\t"                              \
  51        ".hidden _dl_sysinfo_break\n\t"          \
  52        ".proc _dl_sysinfo_break\n\t"            \
  53        "_dl_sysinfo_break:\n\t"                 \
  54        ".prologue\n\t"                          \
  55        ".altrp b6\n\t"                          \
  56        ".body\n\t"                              \
  57        "break 0x100000;\n\t"                    \
  58        "br.ret.sptk.many b6;\n\t"               \
  59        ".endp _dl_sysinfo_break\n\t"            \
  60        ".previous");
  61 #endif
  62
  63 /* _dl_argv cannot be attribute_relro, because _dl_start_user
  64    might write into it after _dl_start returns.  */
  65 #define DL_ARGV_NOT_RELRO 1
  66
  67
  68 /* The _dl_discover_osversion function is so far only needed in sysconf
  69    to check for kernels later than 2.6.23.  */
  70 #if !defined __ASSEMBLER__ && __LINUX_KERNEL_VERSION < 0x020617
  71 /* Get version of the OS.  */
  72 extern int _dl_discover_osversion (void) attribute_hidden;
  73 # define HAVE_DL_DISCOVER_OSVERSION     1
  74 #endif
  75
  76 #endif  /* dl-sysdep.h */