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

From: Zack Weinberg
Date: Fri Oct 30 2020 - 10:18:11 EST


On Fri, Oct 30, 2020 at 9:57 AM Cyril Hrubis <chrubis@xxxxxxx> wrote:
> > 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.
...
> > To be more specific - [if this were supported] 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?

Interference with other processes on the same computer? Some of us
*do* like to run the glibc test suite on computers not entirely
devoted to glibc CI.

zw