sysdeps/x86_64/dl-tlsdesc.h

   1 /* Thread-local storage descriptor handling in the ELF dynamic linker.
   2    x86_64 version.
   3    Copyright (C) 2005, 2008 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _X86_64_DL_TLSDESC_H
  21 # define _X86_64_DL_TLSDESC_H 1
  22
  23 /* Type used to represent a TLS descriptor in the GOT.  */
  24 struct tlsdesc
  25 {
  26   /* Anonymous union is used here to ensure that GOT entry slot is always
  27      8 bytes for both x32 and x86-64.  */
  28   union
  29     {
  30       ptrdiff_t (*entry) (struct tlsdesc *on_rax);
  31       uint64_t entry_slot;
  32     };
  33   union
  34     {
  35       void *arg;
  36       uint64_t arg_slot;
  37     };
  38 };
  39
  40 typedef struct dl_tls_index
  41 {
  42   uint64_t ti_module;
  43   uint64_t ti_offset;
  44 } tls_index;
  45
  46 /* Type used as the argument in a TLS descriptor for a symbol that
  47    needs dynamic TLS offsets.  */
  48 struct tlsdesc_dynamic_arg
  49 {
  50   tls_index tlsinfo;
  51   size_t gen_count;
  52 };
  53
  54 extern ptrdiff_t attribute_hidden
  55   _dl_tlsdesc_return(struct tlsdesc *on_rax),
  56   _dl_tlsdesc_undefweak(struct tlsdesc *on_rax),
  57   _dl_tlsdesc_resolve_rela(struct tlsdesc *on_rax),
  58   _dl_tlsdesc_resolve_hold(struct tlsdesc *on_rax);
  59
  60 # ifdef SHARED
  61 extern void *internal_function _dl_make_tlsdesc_dynamic (struct link_map *map,
  62                                                          size_t ti_offset);
  63
  64 extern ptrdiff_t attribute_hidden _dl_tlsdesc_dynamic(struct tlsdesc *);
  65 # endif
  66
  67 #endif