glibc/sysdeps/unix/sysv/linux/ntp_gettime.c
Lukasz Majewski 5613afe9e3 y2038: linux: Provide __ntp_gettime64 implementation
This patch provides new __ntp_gettime64 explicit 64 bit function for getting
time parameters via NTP interface.

Internally, the __clock_adjtime64 syscall is used instead of __adjtimex. This
patch is necessary for having architectures with __WORDSIZE == 32 Y2038 safe.

Moreover, a 32 bit version - __ntp_gettime has been refactored to internally
use __ntp_gettime64.

The __ntp_gettime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
ntptimeval and 64 bit struct __ntptimeval64.

Build tests:
./src/scripts/build-many-glibcs.py glibcs

Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
  https://github.com/lmajewski/meta-y2038 and run tests:
  https://github.com/lmajewski/y2038-tests/commits/master

Above tests were performed with Y2038 redirection applied as well as without to
test the proper usage of both __ntp_gettime64 and __ntp_gettime.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-05-20 01:09:09 +02:00

62 lines
1.6 KiB
C

/* Copyright (C) 1999-2020 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/>. */
#define ntp_gettime ntp_gettime_redirect
#include <time.h>
#include <sys/timex.h>
#undef ntp_gettime
#ifndef MOD_OFFSET
# define modes mode
#endif
/* clock_adjtime64 with CLOCK_REALTIME does not trigger EINVAL,
ENODEV, or EOPNOTSUPP. It might still trigger EPERM. */
int
__ntp_gettime64 (struct __ntptimeval64 *ntv)
{
struct __timex64 tntx;
int result;
tntx.modes = 0;
result = __clock_adjtime64 (CLOCK_REALTIME, &tntx);
ntv->time = tntx.time;
ntv->maxerror = tntx.maxerror;
ntv->esterror = tntx.esterror;
return result;
}
#if __TIMESIZE != 64
libc_hidden_def (__ntp_gettime64)
int
__ntp_gettime (struct ntptimeval *ntv)
{
struct __ntptimeval64 ntv64;
int result;
result = __ntp_gettime64 (&ntv64);
*ntv = valid_ntptimeval64_to_ntptimeval (ntv64);
return result;
}
#endif
strong_alias (__ntp_gettime, ntp_gettime)