sysdeps/unix/sysv/linux/x86_64/gettimeofday.c

   1 /* Copyright (C) 2002, 2003, 2007, 2011 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <dl-vdso.h>
  20
  21
  22 #define VSYSCALL_ADDR_vgettimeofday     0xffffffffff600000ul
  23
  24
  25 #ifdef SHARED
  26 void *gettimeofday_ifunc (void) __asm__ ("__gettimeofday");
  27
  28 void *
  29 gettimeofday_ifunc (void)
  30 {
  31   PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
  32
  33   /* If the vDSO is not available we fall back on the old vsyscall.  */
  34   return (_dl_vdso_vsym ("gettimeofday", &linux26)
  35           ?: (void *) VSYSCALL_ADDR_vgettimeofday);
  36 }
  37 __asm (".type __gettimeofday, %gnu_indirect_function");
  38 #else
  39 # include <sys/time.h>
  40 # include <sysdep.h>
  41 # include <errno.h>
  42
  43 int
  44 __gettimeofday (struct timeval *tv, struct timezone *tz)
  45 {
  46   return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
  47 }
  48 #endif
  49
  50 weak_alias (__gettimeofday, gettimeofday)
  51 strong_alias (__gettimeofday, __gettimeofday_internal)