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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 F4029C433F5 for ; Mon, 27 Aug 2018 21:42:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 992AA208B8 for ; Mon, 27 Aug 2018 21:42:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 992AA208B8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de 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 S1727545AbeH1BbL (ORCPT ); Mon, 27 Aug 2018 21:31:11 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:43533 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726994AbeH1BbL (ORCPT ); Mon, 27 Aug 2018 21:31:11 -0400 Received: from p4fea45ac.dip0.t-ipconnect.de ([79.234.69.172] helo=[192.168.0.145]) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1fuPHW-0001vq-1i; Mon, 27 Aug 2018 23:42:42 +0200 Date: Mon, 27 Aug 2018 23:42:38 +0200 (CEST) From: Thomas Gleixner To: Miroslav Lichvar cc: Ondrej Mosnacek , Richard Guy Briggs , Linux-Audit Mailing List , Linux kernel mailing list , Stephen Boyd , John Stultz Subject: Re: [PATCH ghak10 v5 2/2] timekeeping/ntp: Audit clock/NTP params adjustments In-Reply-To: <20180827114557.GN27091@localhost> Message-ID: References: <20180824120001.20771-1-omosnace@redhat.com> <20180824120001.20771-3-omosnace@redhat.com> <20180824194703.h3mbuhrxzixmna4e@madcap2.tricolour.ca> <20180827114557.GN27091@localhost> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 27 Aug 2018, Miroslav Lichvar wrote: > 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. Rarely used today, but with TSN it's going to get more usage in not so distant future. Thanks, tglx