On Thu, Sep 13, 2018 at 9:59 AM Ondrej Mosnacek <omosnace(a)redhat.com> wrote:
 On Mon, Aug 27, 2018 at 6:38 PM Steve Grubb <sgrubb(a)redhat.com>
wrote:
 > On Monday, August 27, 2018 5:13:17 AM EDT Ondrej Mosnacek wrote:
 > > On Mon, Aug 27, 2018 at 9:50 AM Miroslav Lichvar <mlichvar(a)redhat.com>
 > wrote:
 > > > On Fri, Aug 24, 2018 at 02:00:00PM +0200, Ondrej Mosnacek wrote:
 > > > > This patch adds two auxiliary record types that will be used to
 > > > > annotate
 > > > > the adjtimex SYSCALL records with the NTP/timekeeping values that
have
 > > > > been changed.
 > > >
 > > > It seems the "adjust" function intentionally logs also
calls/modes
 > > > that don't actually change anything. Can you please explain it a bit
 > > > in the message?
 > > >
 > > > NTP/PTP daemons typically don't read the adjtimex values in a normal
 > > > operation and overwrite them on each update, even if they don't
 > > > change. If the audit function checked that oldval != newval, the
 > > > number of messages would be reduced and it might be easier to follow.
 > >
 > > We actually want to log any attempt to change a value, as even an
 > > intention to set/change something could be a hint that the process is
 > > trying to do something bad (see discussion at [1]).
 >
 > One of the problems is that these applications can flood the logs very
 > quickly. An attempt to change is not needed unless it fails for permissions
 > reasons. So, limiting to actual changes is probably a good thing.
 Well, Richard seemed to "violently" agree with the opposite, so now I
 don't know which way to go... Paul, you are the official tie-breaker
 here, which do you prefer? 
The general idea is that we only care about *changes* to the system
state, so if a process is setting a variable to with a value that
matches it's current value I see no reason why we need to generate a
change record.
Another thing to keep in mind, we can always change the behavior to be
more verbose (*always* generate a record, regardless of value) without
likely causing a regression, but limiting records is more difficult
and more likely to cause regressions.
-- 
paul moore
www.paul-moore.com