Re: [Y2038][time namespaces] Question regarding CLOCK_REALTIME support plans in Linux time namespaces

From: Cyril Hrubis
Date: Fri Oct 30 2020 - 09:57:44 EST


Hi!
> I do have a question regarding the Linux time namespaces in respect of
> adding support for virtualizing the CLOCK_REALTIME.
>
> According to patch description [1] and time_namespaces documentation
> [2] the CLOCK_REALTIME is not supported (for now?) to avoid complexity
> and overhead in the kernel.
>
> Is there any plan to add support for it in a near future?
>
> Why I'm asking?
>
> It looks like this kernel feature (with CLOCK_REALTIME support
> available) would be very helpful for testing Y2038 compliance for e.g.
> glibc 32 bit ports.
>
> To be more specific - it would be possible to modify time after time_t
> 32 bit overflow (i.e. Y2038 bug) on the process running Y2038
> regression tests on the host system (64 bit one). By using Linux time
> namespaces the system time will not be affected in any way.

And what's exactly wrong with moving the system time forward for a
duration of the test?

--
Cyril Hrubis
chrubis@xxxxxxx