sysdeps/unix/sysv/linux/gettimeofday.c

   1 /* gettimeofday - set time.  Linux version.
   2    Copyright (C) 2020-2024 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 License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    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 <string.h>
  21
  22 /* Optimize the function call by setting the PLT directly to vDSO symbol.  */
  23 #ifdef USE_IFUNC_GETTIMEOFDAY
  24 # include <sysdep.h>
  25 # include <sysdep-vdso.h>
  26
  27 # ifdef SHARED
  28 # include <dl-vdso.h>
  29 # include <libc-vdso.h>
  30
  31 static int
  32 __gettimeofday_syscall (struct timeval *restrict tv, void *restrict tz)
  33 {
  34   if (__glibc_unlikely (tz != 0))
  35     memset (tz, 0, sizeof *tz);
  36   return INLINE_SYSCALL_CALL (gettimeofday, tv, tz);
  37 }
  38
  39 # undef INIT_ARCH
  40 # define INIT_ARCH() \
  41   void *vdso_gettimeofday = dl_vdso_vsym (HAVE_GETTIMEOFDAY_VSYSCALL)
  42 libc_ifunc (__gettimeofday,
  43             vdso_gettimeofday ? VDSO_IFUNC_RET (vdso_gettimeofday)
  44                               : (void *) __gettimeofday_syscall)
  45
  46 # else
  47 int
  48 __gettimeofday (struct timeval *restrict tv, void *restrict tz)
  49 {
  50   if (__glibc_unlikely (tz != 0))
  51     memset (tz, 0, sizeof *tz);
  52
  53   return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
  54 }
  55 # endif
  56 weak_alias (__gettimeofday, gettimeofday)
  57 #else /* USE_IFUNC_GETTIMEOFDAY  */
  58 /* Conversion of gettimeofday function to support 64 bit time on archs
  59    with __WORDSIZE == 32 and __TIMESIZE == 32/64  */
  60 #include <errno.h>
  61
  62 int
  63 __gettimeofday64 (struct __timeval64 *restrict tv, void *restrict tz)
  64 {
  65   if (__glibc_unlikely (tz != 0))
  66     memset (tz, 0, sizeof (struct timezone));
  67
  68   struct __timespec64 ts64;
  69   if (__clock_gettime64 (CLOCK_REALTIME, &ts64))
  70           return -1;
  71
  72   *tv = timespec64_to_timeval64 (ts64);
  73   return 0;
  74 }
  75
  76 # if __TIMESIZE != 64
  77 libc_hidden_def (__gettimeofday64)
  78
  79 int
  80 __gettimeofday (struct timeval *restrict tv, void *restrict tz)
  81 {
  82   struct __timeval64 tv64;
  83   if (__gettimeofday64 (&tv64, tz))
  84           return -1;
  85
  86   if (! in_time_t_range (tv64.tv_sec))
  87     {
  88       __set_errno (EOVERFLOW);
  89       return -1;
  90     }
  91
  92   *tv = valid_timeval64_to_timeval (tv64);
  93   return 0;
  94 }
  95 # endif
  96 weak_alias (__gettimeofday, gettimeofday)
  97 #endif