Re: [PATCH] timekeeping: Force upper bound for setting CLOCK_REALTIME

From: Thomas Gleixner
Date: Tue Mar 26 2019 - 08:31:23 EST

On Tue, 26 Mar 2019, Miroslav Lichvar wrote:
> On Sat, Mar 23, 2019 at 11:36:19AM +0100, Thomas Gleixner wrote:
> > It is reasonable to force an upper bound for the various methods of setting
> > CLOCK_REALTIME. Year 2262 is the absolute upper bound. Assume a maximum
> > uptime of 30 years which is plenty enough even for esoteric embedded
> > systems. That results in an upper bound of year 2232 for setting the time.
> The patch looks good to me.
> I like this approach better than using a larger value closer to the
> overflow (e.g. one week) and stepping the clock back automatically
> when the clock reaches that time, but I suspect it might possibly
> break more tests (or any unusual applications messing with time) as a
> much larger interval is now EINVAL.

I'm fine with breaking a few tests on the way rather than having undefined
behaviour and the constant flow of patches tackling the wrong end of the