ports/sysdeps/unix/sysv/linux/m68k/init-first.c

   1 /* Initialization code run first thing by the ELF startup code.  Linux/m68k.
   2    Copyright (C) 2010-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
   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 /* Note: linking in vDSO to a static binary requires changes to
  21    the main GLIBC proper.  Not yet implemented.  */
  22 #ifdef SHARED
  23
  24 #include <dl-vdso.h>
  25 #include <bits/m68k-vdso.h>
  26
  27 static inline void
  28 _libc_vdso_platform_setup (void)
  29 {
  30   void *p;
  31
  32   PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
  33
  34   /* It may happen that rtld didn't initialize the vDSO, so fallback
  35      to the syscall implementations if _dl_vdso_vsym returns NULL.
  36      This may happen when a static executable dlopen's a dynamic library.
  37      This really is nothing more than a workaround for rtld/csu
  38      deficiency.  Ideally, init code would setup the vDSO for static
  39      binaries too.  */
  40
  41   p = _dl_vdso_vsym ("__kernel_read_tp", &linux26);
  42   if (p != NULL)
  43     {
  44       __vdso_read_tp = p;
  45       __rtld___vdso_read_tp = p;
  46     }
  47   else
  48     assert (__vdso_read_tp == (void *) __vdso_read_tp_stub);
  49
  50   p = _dl_vdso_vsym ("__kernel_atomic_cmpxchg_32", &linux26);
  51   if (p != NULL)
  52     {
  53       __vdso_atomic_cmpxchg_32 = p;
  54       __rtld___vdso_atomic_cmpxchg_32 = p;
  55     }
  56   else
  57     assert (__vdso_atomic_cmpxchg_32
  58             == (void *) __vdso_atomic_cmpxchg_32_stub);
  59
  60   p = _dl_vdso_vsym ("__kernel_atomic_barrier", &linux26);
  61   if (p != NULL)
  62     {
  63       __vdso_atomic_barrier = p;
  64       __rtld___vdso_atomic_barrier = p;
  65     }
  66   else
  67     assert (__vdso_atomic_barrier == (void *) __vdso_atomic_barrier_stub);
  68 }
  69
  70 #define VDSO_SETUP _libc_vdso_platform_setup
  71
  72 #endif /* SHARED */
  73
  74 #include <csu/init-first.c>