glibc/sysdeps/unix/sysv/linux/adjtimex.c
Lukasz Majewski 8f8a6cae48 y2038: linux: Provide ___adjtimex64 implementation
This patch provides new ___adjtimex64 explicit 64 bit function for adjusting
Linux kernel clock.

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

Moreover, a 32 bit version - ___adjtimex has been refactored to internally
use ___adjtimex64.

The ___adjtimex is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
timex and 64 bit struct __timex64.

Last but not least, in ___adjtimex64 function the __clock_adjtime syscall has
been replaced with __clock_adjtime64 to support 64 bit time on architectures
with __WORDSIZE == 32 and __TIMESIZE != 64.

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 ___adjtimex64 and ___adjtimex.

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

58 lines
1.7 KiB
C

/* Tune kernel clock. Linux specific syscall.
Copyright (C) 2019-2020 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
<http://www.gnu.org/licenses/>. */
#include <sys/timex.h>
#include <sysdep.h>
int
___adjtimex64 (struct __timex64 *tx64)
{
return __clock_adjtime64 (CLOCK_REALTIME, tx64);
}
#if __TIMESIZE != 64
libc_hidden_def (___adjtimex64)
int
___adjtimex (struct timex *tx)
{
struct __timex64 tx64;
int retval;
tx64 = valid_timex_to_timex64 (*tx);
retval = ___adjtimex64 (&tx64);
*tx = valid_timex64_to_timex (tx64);
return retval;
}
#endif
#ifdef VERSION_adjtimex
weak_alias (___adjtimex, __wadjtimex);
weak_alias (___adjtimex, __wnadjtime);
default_symbol_version (___adjtimex, __adjtimex, VERSION_adjtimex);
default_symbol_version (__wadjtimex, adjtimex, VERSION_adjtimex);
default_symbol_version (__wnadjtime, ntp_adjtime, VERSION_adjtimex);
libc_hidden_ver (___adjtimex, __adjtimex);
#else
strong_alias (___adjtimex, __adjtimex)
weak_alias (___adjtimex, adjtimex)
weak_alias (___adjtimex, ntp_adjtime)
libc_hidden_def (__adjtimex)
#endif