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Date:   Wed, 14 Mar 2018 01:28:57 +0100 (CET)
From:   Jiri Kosina <jikos@kernel.org>
To:     Andy Lutomirski <luto@kernel.org>
cc:     Steve Grubb <sgrubb@redhat.com>, Paul Moore <paul@paul-moore.com>,
        linux-audit@redhat.com, Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@suse.com>,
        Oleg Nesterov <oleg@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] audit: set TIF_AUDIT_SYSCALL only if audit filter has
 been populated
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On Wed, 14 Mar 2018, Andy Lutomirski wrote:

> > Yes...I wished I was in on the beginning of this discussion. Here's the
> > problem. We need all tasks auditable unless specifically dismissed as
> > uninteresting. This would be a task,never rule.
> >
> > The way we look at it, is if it boots with audit=1, then we know auditd
> > is expected to run at some point. So, we need all tasks to stay
> > auditable. If they weren't and auditd enabled auditing, then we'd need
> > to walk the whole proctable and stab TIF_AUDIT_SYSCALL into every
> > process in the system. It was decided that this is too ugly.
> 
> When was that decided?  That's what this patch does.

I'd like to see some more justification as well.

Namely, if I compare "setting TIF_AUDIT_SYSCALL for every process on a 
need-to-be-so basis" to "we always go through the slow path and 
pessimistically assume that audit is enabled and has reasonable ruleset 
loaded", I have my own (different) opinion of what is too ugly.

Thanks,

-- 
Jiri Kosina
SUSE Labs