mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-04 19:00:09 +00:00
75c4044b9a
In the glibc the time function can use vDSO (on power and x86 the USE_IFUNC_TIME is defined), time syscall or 'default' time() from ./time/time.c (as a fallback). In this patch the last function (time) has been refactored and moved to ./sysdeps/unix/sysv/linux/time.c to be Linux specific. The new __time64 explicit 64 bit function for providing 64 bit value of seconds after epoch (by internally calling __clock_gettime64) has been introduced. Moreover, a 32 bit version - __time has been refactored to internally use __time64. The __time is now supposed to be used on systems still supporting 32 bit time (__TIMESIZE != 64) - hence the necessary check for time_t potential overflow. The iFUNC vDSO direct call optimization has been removed from both i686 and powerpc32 (USE_IFUNC_TIME is not defined for those architectures anymore). The Linux kernel does not provide a y2038 safe implementation of time neither it plans to provide it in the future, __clock_gettime64 should be used instead. Keeping support for this optimization would require to handle another build permutation (!__ASSUME_TIME64_SYSCALLS && USE_IFUNC_TIME which adds more complexity and has limited use (since the idea is to eventually have a y2038 safe glibc build). 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 proper usage of both __time64 and __time. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
88 lines
2.0 KiB
C
88 lines
2.0 KiB
C
/* time -- Get number of seconds since Epoch. Linux version.
|
|
Copyright (C) 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/>. */
|
|
|
|
/* Optimize the function call by setting the PLT directly to vDSO symbol. */
|
|
#ifdef USE_IFUNC_TIME
|
|
# include <time.h>
|
|
# include <sysdep.h>
|
|
# include <sysdep-vdso.h>
|
|
|
|
#ifdef SHARED
|
|
# include <dl-vdso.h>
|
|
# include <libc-vdso.h>
|
|
|
|
static time_t
|
|
time_syscall (time_t *t)
|
|
{
|
|
return INLINE_SYSCALL_CALL (time, t);
|
|
}
|
|
|
|
# undef INIT_ARCH
|
|
# define INIT_ARCH() \
|
|
void *vdso_time = dl_vdso_vsym (HAVE_TIME_VSYSCALL);
|
|
libc_ifunc (time,
|
|
vdso_time ? VDSO_IFUNC_RET (vdso_time)
|
|
: (void *) time_syscall);
|
|
|
|
# else
|
|
time_t
|
|
time (time_t *t)
|
|
{
|
|
return INLINE_VSYSCALL (time, 1, t);
|
|
}
|
|
# endif /* !SHARED */
|
|
#else /* USE_IFUNC_TIME */
|
|
# include <time.h>
|
|
# include <time-clockid.h>
|
|
# include <errno.h>
|
|
|
|
/* Return the time now, and store it in *TIMER if not NULL. */
|
|
|
|
__time64_t
|
|
__time64 (__time64_t *timer)
|
|
{
|
|
struct __timespec64 ts;
|
|
__clock_gettime64 (TIME_CLOCK_GETTIME_CLOCKID, &ts);
|
|
|
|
if (timer != NULL)
|
|
*timer = ts.tv_sec;
|
|
return ts.tv_sec;
|
|
}
|
|
|
|
# if __TIMESIZE != 64
|
|
libc_hidden_def (__time64)
|
|
|
|
time_t
|
|
__time (time_t *timer)
|
|
{
|
|
__time64_t t = __time64 (NULL);
|
|
|
|
if (! in_time_t_range (t))
|
|
{
|
|
__set_errno (EOVERFLOW);
|
|
return -1;
|
|
}
|
|
|
|
if (timer != NULL)
|
|
*timer = t;
|
|
return t;
|
|
}
|
|
# endif
|
|
weak_alias (__time, time)
|
|
#endif
|