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

   1 /* System-specific settings for dynamic linker code.  IA-64 version.
   2    Copyright (C) 2003-2024 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 _LINUX_IA64_DL_SYSDEP_H
  20 #define _LINUX_IA64_DL_SYSDEP_H 1
  21
  22 #include_next <dl-sysdep.h>
  23
  24 /* Traditionally system calls have been made using break 0x100000.  A
  25    second method was introduced which, if possible, will use the EPC
  26    instruction.  To signal the presence and where to find the code the
  27    kernel passes an AT_SYSINFO_EHDR pointer in the auxiliary vector to
  28    the application.  */
  29 #define NEED_DL_SYSINFO 1
  30 #define USE_DL_SYSINFO  1
  31
  32 #ifndef __ASSEMBLER__
  33 /* Don't declare this as a function---we want it's entry-point, not
  34    it's function descriptor... */
  35 /* Use section ".text" to force far GPREL64 relocation instead of
  36    GPREL22. */
  37 extern int _dl_sysinfo_break attribute_hidden __attribute__((section(".text")));
  38 # define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
  39 # define DL_SYSINFO_IMPLEMENTATION              \
  40   asm (".text\n\t"                              \
  41        ".hidden _dl_sysinfo_break\n\t"          \
  42        ".proc _dl_sysinfo_break\n\t"            \
  43        "_dl_sysinfo_break:\n\t"                 \
  44        ".prologue\n\t"                          \
  45        ".altrp b6\n\t"                          \
  46        ".body\n\t"                              \
  47        "break 0x100000;\n\t"                    \
  48        "br.ret.sptk.many b6;\n\t"               \
  49        ".endp _dl_sysinfo_break\n\t"            \
  50        ".previous");
  51 #endif
  52
  53 #endif  /* dl-sysdep.h */