glibc/sysdeps/unix/sysv/linux/clock_settime.c
Lukasz Majewski 7ce198e123 y2038: linux: Provide __clock_settime64 implementation
This patch provides new __clock_settime64 explicit 64 bit function for
setting the time. Moreover, a 32 bit version - __clock_settime - has been
refactored to internally use __clock_settime64.

The __clock_settime is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit
struct timespec.

The new clock_settime64 syscall available from Linux 5.1+ has been used,
when applicable.

In this patch the internal padding (tv_pad) of struct __timespec64 is
left untouched (on systems with __WORDSIZE == 32) as Linux kernel ignores
upper 32 bits of tv_nsec.

Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8"

- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7

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

- Use of cross-test-ssh.sh for ARM (armv7):
  make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck

Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with clock_settime64) and glibc build with v5.1 as minimal
  kernel version (--enable-kernel="5.1.0")
  The __ASSUME_TIME64_SYSCALLS flag defined.

- Linux v5.1 and default minimal kernel version
  The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
  __clock_settime64 syscalls.

- Linux v4.19 (no clock_settime64 support) with default minimal kernel
  version for contemporary glibc

  This kernel doesn't support __clock_settime64 syscalls, so the fallback
  to clock_settime is tested.

The above tests were performed with Y2038 redirection applied as well as
without (so the __TIMESIZE != 64 execution path is checked as well).

No regressions were observed.

* include/time.h (__clock_settime64):
  Add __clock_settime alias according to __TIMESIZE define
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime):
  Refactor this function to be used only on 32 bit machines as a wrapper
  on __clock_settime64.
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64): Add
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64):
  Use clock_settime64 kernel syscall (available from 5.1+ Linux)
2019-10-10 00:17:46 +02:00

75 lines
2.3 KiB
C

/* Copyright (C) 2003-2019 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 <sysdep.h>
#include <time.h>
#include <shlib-compat.h>
/* Set CLOCK to value TP. */
int
__clock_settime64 (clockid_t clock_id, const struct __timespec64 *tp)
{
/* Make sure the time cvalue is OK. */
if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000)
{
__set_errno (EINVAL);
return -1;
}
#ifdef __ASSUME_TIME64_SYSCALLS
# ifndef __NR_clock_settime64
# define __NR_clock_settime64 __NR_clock_settime
# endif
return INLINE_SYSCALL_CALL (clock_settime64, clock_id, tp);
#else
# ifdef __NR_clock_settime64
int ret = INLINE_SYSCALL_CALL (clock_settime64, clock_id, tp);
if (ret == 0 || errno != ENOSYS)
return ret;
# endif
if (! in_time_t_range (tp->tv_sec))
{
__set_errno (EOVERFLOW);
return -1;
}
struct timespec ts32 = valid_timespec64_to_timespec (*tp);
return INLINE_SYSCALL_CALL (clock_settime, clock_id, &ts32);
#endif
}
#if __TIMESIZE != 64
int
__clock_settime (clockid_t clock_id, const struct timespec *tp)
{
struct __timespec64 ts64 = valid_timespec_to_timespec64 (*tp);
return __clock_settime64 (clock_id, &ts64);
}
#endif
libc_hidden_def (__clock_settime)
versioned_symbol (libc, __clock_settime, clock_settime, GLIBC_2_17);
/* clock_settime 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_settime, __clock_settime_2);
compat_symbol (libc, __clock_settime_2, clock_settime, GLIBC_2_2);
#endif