Re: [PATCH ghak10 v5 2/2] timekeeping/ntp: Audit clock/NTP params adjustments

From: Miroslav Lichvar
Date: Mon Aug 27 2018 - 07:46:09 EST

On Mon, Aug 27, 2018 at 01:35:09PM +0200, Ondrej Mosnacek wrote:
> On Fri, Aug 24, 2018 at 9:51 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> > It appears this time_tai use of "constant" is different than
> > time_constant, the former not mentioned by Miroslav Lichvar. What is it
> > and is it important to log for security? It sounds like it is
> > important.

> The TAI offset is the offset of the clock from the International
> Atomic Time, so basically the time zone offset. I suppose it can't
> influence the audit timestamps, but changing timezones can still cause
> all sorts of confusion throughout the system, so intuitively I would
> say we should log it.

It's not related to timezones. ADJ_TAI sets the offset of the system
TAI clock (CLOCK_TAI) relative to the standard UTC clock
(CLOCK_REALTIME). CLOCK_TAI is rarely used by applications. Setting
the TAI offset effectively injects a whole-second offset to the TAI

Miroslav Lichvar