Lukasz Majewski 75c4044b9a y2038: linux: Provide __time64 implementation ... 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>		2020-10-19 16:01:37 +02:00
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linux	y2038: linux: Provide __time64 implementation	2020-10-19 16:01:37 +02:00