From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2269C433F5 for ; Mon, 27 Aug 2018 11:46:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89F3120658 for ; Mon, 27 Aug 2018 11:46:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89F3120658 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727408AbeH0Pc0 (ORCPT ); Mon, 27 Aug 2018 11:32:26 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:46050 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726931AbeH0PcZ (ORCPT ); Mon, 27 Aug 2018 11:32:25 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DE2CF804B9F1; Mon, 27 Aug 2018 11:46:05 +0000 (UTC) Received: from localhost (unknown [10.43.134.11]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2784F2026D6B; Mon, 27 Aug 2018 11:46:01 +0000 (UTC) Date: Mon, 27 Aug 2018 13:45:57 +0200 From: Miroslav Lichvar To: Ondrej Mosnacek Cc: Richard Guy Briggs , Linux-Audit Mailing List , Linux kernel mailing list , Stephen Boyd , John Stultz , Thomas Gleixner Subject: Re: [PATCH ghak10 v5 2/2] timekeeping/ntp: Audit clock/NTP params adjustments Message-ID: <20180827114557.GN27091@localhost> References: <20180824120001.20771-1-omosnace@redhat.com> <20180824120001.20771-3-omosnace@redhat.com> <20180824194703.h3mbuhrxzixmna4e@madcap2.tricolour.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.0 (2018-05-17) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 27 Aug 2018 11:46:05 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 27 Aug 2018 11:46:05 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mlichvar@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 time. -- Miroslav Lichvar