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

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