glibc/sysdeps/unix/sysv/linux/adjtime.c
Lukasz Majewski 0308077e3a y2038: linux: Provide __adjtime64 implementation
This patch provides new __adjtime64 explicit 64 bit function for adjusting
Linux kernel clock.

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 - __adjtime has been refactored to internally use
__adjtime64.

The __adjtime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
timeval and 64 bit struct __timeval64.

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 __adjtime64 and __adjtime.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-05-20 01:03:26 +02:00

89 lines
2.3 KiB
C

/* Copyright (C) 1995-2020 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 <errno.h>
#include <limits.h>
#include <sys/time.h>
#include <sys/timex.h>
#define MAX_SEC (INT_MAX / 1000000L - 2)
#define MIN_SEC (INT_MIN / 1000000L + 2)
int
__adjtime64 (const struct __timeval64 *itv, struct __timeval64 *otv)
{
struct __timex64 tntx;
if (itv)
{
struct __timeval64 tmp;
/* We will do some check here. */
tmp.tv_sec = itv->tv_sec + itv->tv_usec / 1000000L;
tmp.tv_usec = itv->tv_usec % 1000000L;
if (tmp.tv_sec > MAX_SEC || tmp.tv_sec < MIN_SEC)
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
tntx.offset = tmp.tv_usec + tmp.tv_sec * 1000000L;
tntx.modes = ADJ_OFFSET_SINGLESHOT;
}
else
tntx.modes = ADJ_OFFSET_SS_READ;
if (__glibc_unlikely (__clock_adjtime64 (CLOCK_REALTIME, &tntx) < 0))
return -1;
if (otv)
{
if (tntx.offset < 0)
{
otv->tv_usec = -(-tntx.offset % 1000000);
otv->tv_sec = -(-tntx.offset / 1000000);
}
else
{
otv->tv_usec = tntx.offset % 1000000;
otv->tv_sec = tntx.offset / 1000000;
}
}
return 0;
}
#if __TIMESIZE != 64
libc_hidden_def (__adjtime64)
int
__adjtime (const struct timeval *itv, struct timeval *otv)
{
struct __timeval64 itv64, otv64;
int retval;
itv64 = valid_timeval_to_timeval64 (*itv);
retval = __adjtime64 (&itv64, otv != NULL ? &otv64 : NULL);
if (otv != NULL)
*otv = valid_timeval64_to_timeval (otv64);
return retval;
}
#endif
#ifdef VERSION_adjtime
weak_alias (__adjtime, __wadjtime);
default_symbol_version (__wadjtime, adjtime, VERSION_adjtime);
#else
weak_alias (__adjtime, adjtime)
#endif