[Xenomai] Winter^W y2038 is coming

Jan Kiszka jan.kiszka at siemens.com
Wed Feb 21 19:33:20 CET 2018


Hi,

likely due to some platform oddities (still has to be analyzed in more
details), we are running into the situation that xntimer_grab_hardware
on a x86-64 host tunes nkclock.wallclock_offset to a value that is not
compatible with the 32-bit time_t ABI of compat applications. If you do
a pattern like

    abs_timeout = clock_gettime(CLOCK_REALTIME) + rel_timeout
    some_abs_wait(abs_timeout)

that abs_wait will practically wait forever. The same bug can also be
triggered by doing a

    clock_settime(CLOCK_REALTIME, -negative_date)

I'm now wondering if we should take measures that detect or even prevent
the setting of invalid dates in the presence of 32-bit ABIs. Or if we
should suggest/demand the setting of -D_TIME_BITS=64 already. The clock
is ticking... Thoughts?

Jan

-- 
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux



More information about the Xenomai mailing list