sysdeps/unix/sysv/linux/x86/time.c

   1 /* time -- Get number of seconds since Epoch.  Linux/x86 version.
   2    Copyright (C) 2015-2019 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <time.h>
  20 #include <sysdep.h>
  21
  22 #ifdef HAVE_TIME_VSYSCALL
  23 # define HAVE_VSYSCALL
  24 #endif
  25 #include <sysdep-vdso.h>
  26
  27 static time_t
  28 time_vsyscall (time_t *t)
  29 {
  30   return INLINE_VSYSCALL (time, 1, t);
  31 }
  32
  33 #ifdef SHARED
  34 # include <dl-vdso.h>
  35 # include <libc-vdso.h>
  36
  37 #undef INIT_ARCH
  38 #define INIT_ARCH()
  39 /* If the vDSO is not available we fall back on the syscall.  */
  40 libc_ifunc (time, (get_vdso_symbol ("__vdso_time") ?: time_vsyscall))
  41 #else
  42 time_t
  43 time (time_t *t)
  44 {
  45   return time_vsyscall (t);
  46 }
  47 #endif