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>
23 lines
923 B
C
23 lines
923 B
C
/* time system call for Linux/PowerPC.
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Copyright (C) 2013-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#ifdef __powerpc64__
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# define USE_IFUNC_TIME
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#endif
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#include <sysdeps/unix/sysv/linux/time.c>
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