glibc/sysdeps/unix/sysv/linux/features-time64.h
Adhemerval Zanella 47f24c21ee y2038: Add support for 64-bit time on legacy ABIs
A new build flag, _TIME_BITS, enables the usage of the newer 64-bit
time symbols for legacy ABI (where 32-bit time_t is default).  The 64
bit time support is only enabled if LFS (_FILE_OFFSET_BITS=64) is
also used.

Different than LFS support, the y2038 symbols are added only for the
required ABIs (armhf, csky, hppa, i386, m68k, microblaze, mips32,
mips64-n32, nios2, powerpc32, sparc32, s390-32, and sh).  The ABIs with
64-bit time support are unchanged, both for symbol and types
redirection.

On Linux the full 64-bit time support requires a minimum of kernel
version v5.1.  Otherwise, the 32-bit fallbacks are used and might
results in error with overflow return code (EOVERFLOW).

The i686-gnu does not yet support 64-bit time.

This patch exports following rediretions to support 64-bit time:

  * libc:
    adjtime
    adjtimex
    clock_adjtime
    clock_getres
    clock_gettime
    clock_nanosleep
    clock_settime
    cnd_timedwait
    ctime
    ctime_r
    difftime
    fstat
    fstatat
    futimens
    futimes
    futimesat
    getitimer
    getrusage
    gettimeofday
    gmtime
    gmtime_r
    localtime
    localtime_r
    lstat_time
    lutimes
    mktime
    msgctl
    mtx_timedlock
    nanosleep
    nanosleep
    ntp_gettime
    ntp_gettimex
    ppoll
    pselec
    pselect
    pthread_clockjoin_np
    pthread_cond_clockwait
    pthread_cond_timedwait
    pthread_mutex_clocklock
    pthread_mutex_timedlock
    pthread_rwlock_clockrdlock
    pthread_rwlock_clockwrlock
    pthread_rwlock_timedrdlock
    pthread_rwlock_timedwrlock
    pthread_timedjoin_np
    recvmmsg
    sched_rr_get_interval
    select
    sem_clockwait
    semctl
    semtimedop
    sem_timedwait
    setitimer
    settimeofday
    shmctl
    sigtimedwait
    stat
    thrd_sleep
    time
    timegm
    timerfd_gettime
    timerfd_settime
    timespec_get
    utime
    utimensat
    utimes
    utimes
    wait3
    wait4

  * librt:
    aio_suspend
    mq_timedreceive
    mq_timedsend
    timer_gettime
    timer_settime

  * libanl:
    gai_suspend

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-06-15 10:42:11 -03:00

38 lines
1.4 KiB
C

/* Features part to handle 64-bit time_t support.
Copyright (C) 2021 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/>. */
/* We need to know the word size in order to check the time size. */
#include <bits/wordsize.h>
#include <bits/timesize.h>
#if defined _TIME_BITS
# if _TIME_BITS == 64
# if ! defined (_FILE_OFFSET_BITS) || _FILE_OFFSET_BITS != 64
# error "_TIME_BITS=64 is allowed only with _FILE_OFFSET_BITS=64"
# elif __TIMESIZE == 32
# define __USE_TIME_BITS64 1
# endif
# elif _TIME_BITS == 32
# if __TIMESIZE > 32
# error "_TIME_BITS=32 is not compatible with __TIMESIZE > 32"
# endif
# else
# error Invalid _TIME_BITS value (can only be 32 or 64-bit)
# endif
#endif