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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 CA2A7C433DF for ; Thu, 2 Jul 2020 07:17:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A518320874 for ; Thu, 2 Jul 2020 07:17:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uOIvURjI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727059AbgGBHRH (ORCPT ); Thu, 2 Jul 2020 03:17:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726092AbgGBHRG (ORCPT ); Thu, 2 Jul 2020 03:17:06 -0400 Received: from mail-qt1-x832.google.com (mail-qt1-x832.google.com [IPv6:2607:f8b0:4864:20::832]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91D07C08C5C1 for ; Thu, 2 Jul 2020 00:17:06 -0700 (PDT) Received: by mail-qt1-x832.google.com with SMTP id e12so20465994qtr.9 for ; Thu, 02 Jul 2020 00:17:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YGNoN9gtKrPMd4VU+QtOqyOlxcTtDvTp63S5slWM6mM=; b=uOIvURjIalAjnHSsgHyuCTb8qLuF6jKARWgTAOlSiLQWd6533oNYC2lBSsNtWc5mOi P944b9rSSrwLKTlZ7v7ZZ3lGT3eLo/jKaFE9PQl66X5JQDATnqYPVAUsk7/0H8Eu9zoS /kJ+UEkhVqr1QtpyXe9Ilh3FxlYuyzDLDEcm19H1Ay4B/IbFc0o45LKThc0ZmUau8V80 RmXoymIzYsMQ10n9yq4uUwo/RjPmGnTzc/JI4SyBo4KCOG8ENitfQ+bO6B2IR29yimIp 6IJLJ+EXFV4q6Ozg4VgjzOgk/rPKEmewVBYPxwOjHpDgfqjyprvtQB8f1j3Bb6k6mLxg K/cA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YGNoN9gtKrPMd4VU+QtOqyOlxcTtDvTp63S5slWM6mM=; b=CThuSQ+3OIIDbqZoni3kRnplNvS3RffnOIwhLKryVp6w0VYvd4+tMYC6L90EpO/0PH jMCpVoZw9fu9zTZ7OZ9DQuVqUkaSE91c3MgcdQOyznkanq/UHapr6eo7qoI6WHgC2a0S iy0/Y2J0uSEljDuVdh6mgrG1AsUroPAkJcgZWW8PRLCGgcPUKylWSVo6dqzrOTaQXzAD mRT5fyYrgC1U01Vxr+aubbLIOg118Ea8XNBFSDyfHFOOcWvvD0l/wEE6BFlJc1CcdDhO rsUHF0vZO1mYIYA7l4JyZO9cEXUqNmMMBbUJlS7ep7NSaSq1jaB7JjNZho0JQx2detCb WtoA== X-Gm-Message-State: AOAM533JLMoAZMJL/n6ILXmZku+O+TxineCXPHZcyD8/mpBpku0Vw5P8 9Py2Gj36bSzcJMwM6m6a77+wVA7U+alB/Y+gC6xg+fAn X-Google-Smtp-Source: ABdhPJx7+EYYrzfggg1q8gmEqmhYgQYjXmrfHZwNIXfEUIyn79Dny6FStGxiTd1BwrjKnotUnpcmIp22KMtQNNiJEBk= X-Received: by 2002:ac8:5188:: with SMTP id c8mr30441163qtn.1.1593674225151; Thu, 02 Jul 2020 00:17:05 -0700 (PDT) MIME-Version: 1.0 References: <20200701132309.GA2362785@kroah.com> In-Reply-To: <20200701132309.GA2362785@kroah.com> From: Egmont Koblinger Date: Thu, 2 Jul 2020 09:16:28 +0200 Message-ID: Subject: Re: PROBLEM: tty devices with future timestamps To: Greg KH Cc: linux-serial@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Hi Greg, > What is this "problem" causing today? This is probably only a cosmetic issue, rather than a strictly-speaking bug. I mean, the tty line works fine, and the 8 second resolution is a nice prevention against security/privacy issues. I'm not aware of any misbehavior in any application (which, of course, does not guarantee that there isn't any). That being said, the device regularly having a future timestamp (and in turn, "ls -l" using a different formatting) is totally unexpected, and made me (and perhaps will make others) think that there must be something wrong with the system. Is this a bug in coreutils's "ls"? (That was my first suspect.) ... Or am I experiencing clock skews? Due to a hardware flaw? Due to an ntp problem? Is there a chance it'll affect some apps too? ... Or what else could it be? ... -- I was wondering. If the code cares enough to update the timestamp at all -- which I would be fine without, I personally wouldn't mind if it stayed at the creation time of that tty line, or was always the Epoch --, and cares enough to reduce the precision -- which I find a good thing --, then I guess it should also take care of not setting it to a future timestamp, in order not to cause unexpected end-user results in "ls -l" and who knows what other tools. thanks for your consideration, egmont