sysdeps/i386/dl-tls.h

   1 /* Thread-local storage handling in the ELF dynamic linker.  i386 version.
   2    Copyright (C) 2002, 2004 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20
  21 /* Type used for the representation of TLS information in the GOT.  */
  22 typedef struct
  23 {
  24   unsigned long int ti_module;
  25   unsigned long int ti_offset;
  26 } tls_index;
  27
  28
  29 #ifdef SHARED
  30 /* This is the prototype for the GNU version.  */
  31 extern void *___tls_get_addr (tls_index *ti)
  32      __attribute__ ((__regparm__ (1)));
  33 extern void *___tls_get_addr_internal (tls_index *ti)
  34      __attribute__ ((__regparm__ (1))) attribute_hidden;
  35
  36 # ifdef IS_IN_rtld
  37 /* The special thing about the x86 TLS ABI is that we have two
  38    variants of the __tls_get_addr function with different calling
  39    conventions.  The GNU version, which we are mostly concerned here,
  40    takes the parameter in a register.  The name is changed by adding
  41    an additional underscore at the beginning.  The Sun version uses
  42    the normal calling convention.  */
  43 void *
  44 __tls_get_addr (tls_index *ti)
  45 {
  46   return ___tls_get_addr_internal (ti);
  47 }
  48
  49
  50 /* Prepare using the definition of __tls_get_addr in the generic
  51    version of this file.  */
  52 # define __tls_get_addr __attribute__ ((__regparm__ (1))) ___tls_get_addr
  53 strong_alias (___tls_get_addr, ___tls_get_addr_internal)
  54 #else
  55
  56 /* Users should get the better interface.  */
  57 # define __tls_get_addr ___tls_get_addr
  58
  59 # endif
  60 #endif