glibc/sysdeps/unix/sysv/linux/clock_gettime.c
Adhemerval Zanella d9310f33fc linux: Simplify clock_gettime
With arch-syscall.h it can now assumes the existance of either
__NR_clock_gettime or __NR_clock_gettime_time64.  The 32-bit time_t
support is now only build for !__ASSUME_TIME64_SYSCALLS.

It also uses the time64-support functions to simplify it further.

Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).
2020-08-24 14:28:21 -03:00

101 lines
2.7 KiB
C

/* clock_gettime -- Get current time from a POSIX clockid_t. Linux version.
Copyright (C) 2003-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <kernel-features.h>
#include <errno.h>
#include <time.h>
#include "kernel-posix-cpu-timers.h"
#include <sysdep-vdso.h>
#include <time64-support.h>
#include <shlib-compat.h>
/* Get current value of CLOCK and store it in TP. */
int
__clock_gettime64 (clockid_t clock_id, struct __timespec64 *tp)
{
int r;
#ifndef __NR_clock_gettime64
# define __NR_clock_gettime64 __NR_clock_gettime
#endif
if (supports_time64 ())
{
#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
r = INLINE_VSYSCALL (clock_gettime64, 2, clock_id, tp);
#else
r = INLINE_SYSCALL_CALL (clock_gettime64, clock_id, tp);
#endif
if (r == 0 || errno != ENOSYS)
return r;
mark_time64_unsupported ();
}
#ifndef __ASSUME_TIME64_SYSCALLS
/* Fallback code that uses 32-bit support. */
struct timespec tp32;
# ifdef HAVE_CLOCK_GETTIME_VSYSCALL
r = INLINE_VSYSCALL (clock_gettime, 2, clock_id, &tp32);
# else
r = INLINE_SYSCALL_CALL (clock_gettime, clock_id, &tp32);
# endif
if (r == 0)
*tp = valid_timespec_to_timespec64 (tp32);
#endif
return r;
}
#if __TIMESIZE != 64
libc_hidden_def (__clock_gettime64)
int
__clock_gettime (clockid_t clock_id, struct timespec *tp)
{
int ret;
struct __timespec64 tp64;
ret = __clock_gettime64 (clock_id, &tp64);
if (ret == 0)
{
if (! in_time_t_range (tp64.tv_sec))
{
__set_errno (EOVERFLOW);
return -1;
}
*tp = valid_timespec64_to_timespec (tp64);
}
return ret;
}
#endif
libc_hidden_def (__clock_gettime)
versioned_symbol (libc, __clock_gettime, clock_gettime, GLIBC_2_17);
/* clock_gettime moved to libc in version 2.17;
old binaries may expect the symbol version it had in librt. */
#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
strong_alias (__clock_gettime, __clock_gettime_2);
compat_symbol (libc, __clock_gettime_2, clock_gettime, GLIBC_2_2);
#endif