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

   1 /* time system call for Linux/PowerPC.
   2    Copyright (C) 2013-2019 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 #ifdef SHARED
  20 # ifndef __powerpc64__
  21 #  define time __redirect_time
  22 # else
  23 #  define __redirect_time time
  24 # endif
  25
  26 # include <time.h>
  27 # include <sysdep.h>
  28 # include <dl-vdso.h>
  29 # include <libc-vdso.h>
  30 # include <dl-machine.h>
  31
  32 # ifndef __powerpc64__
  33 #  undef time
  34
  35 time_t
  36 __time_vsyscall (time_t *t)
  37 {
  38   return INLINE_VSYSCALL (time, 1, t);
  39 }
  40
  41 /* __GI_time is defined as hidden and for ppc32 it enables the
  42    compiler make a local call (symbol@local) for internal GLIBC usage. It
  43    means the PLT won't be used and the ifunc resolver will be called directly.
  44    For ppc64 a call to a function in another translation unit might use a
  45    different toc pointer thus disallowing direct branchess and making internal
  46    ifuncs calls safe.  */
  47 #  undef libc_hidden_def
  48 #  define libc_hidden_def(name)                                 \
  49   __hidden_ver1 (__time_vsyscall, __GI_time, __time_vsyscall);
  50
  51 # endif /* !__powerpc64__  */
  52
  53 static time_t
  54 time_syscall (time_t *t)
  55 {
  56   struct timeval tv;
  57   time_t result;
  58
  59   if (INLINE_VSYSCALL (gettimeofday, 2, &tv, NULL) < 0)
  60     result = (time_t) -1;
  61   else
  62     result = (time_t) tv.tv_sec;
  63
  64   if (t != NULL)
  65     *t = result;
  66   return result;
  67 }
  68
  69 # define INIT_ARCH() \
  70   void *vdso_time = get_vdso_symbol ("__kernel_time");
  71
  72 /* If the vDSO is not available we fall back to the syscall.  */
  73 libc_ifunc_hidden (__redirect_time, time,
  74                    vdso_time
  75                    ? VDSO_IFUNC_RET (vdso_time)
  76                    : (void *) time_syscall);
  77 libc_hidden_def (time)
  78
  79 #else
  80
  81 #include <sysdeps/posix/time.c>
  82
  83 #endif /* !SHARED */