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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 F21EAC4363A for ; Mon, 26 Oct 2020 10:28:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76A3A2076D for ; Mon, 26 Oct 2020 10:28:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="a59eYWCj"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="7HGCcKJw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1769756AbgJZK2j (ORCPT ); Mon, 26 Oct 2020 06:28:39 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:38970 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1768430AbgJZK2j (ORCPT ); Mon, 26 Oct 2020 06:28:39 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603708117; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c5fTWk6slj+E7imkK9HrK7ftFSS9/gEK4mhZa60fVww=; b=a59eYWCjVaoI70IOQEnbNuzuWBVg+sv/beJmPWWVAZoa7wTcySRitCjwTg8UDoCOtLLljk 4LOVX1/a5bgJc0LAdJr8FwZrsnCJ1LF2EoyRl1pIaTBUTG2kcfLEOZ5nwr0BO6++sDnPFR JxFoC0CPIJ7dBZI/cTDiB7RH+xPYl5XoAKOauL6gs/USy2ZXPwnX0wn6H0dzk7MVPlqDrN P10oyZjMBUg0WPBxiYc2cyzNxSQbCPH0Vmx2A8lzbzG4A6G81R5qoqhOjkJrAPn1Q+cNxC acY+xgZF9A7PxwhUXC819G4r7vHduvm2GjMj3dZqLi6hxGd/t8IZZcxM8VH5gA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603708117; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c5fTWk6slj+E7imkK9HrK7ftFSS9/gEK4mhZa60fVww=; b=7HGCcKJw8egDLGjooY9uyvL/oAjzh0Cg+iV5QgyFo4Ggn9x20kUVnvK0CPmUtkpxcoZ49w C+sQtg7wAE42b3Bg== To: Michael =?utf-8?Q?Wei=C3=9F?= , Andrei Vagin , Christian Brauner Cc: Dmitry Safonov <0x7f454c46@gmail.com>, linux-kernel@vger.kernel.org, "J . Bruce Fields" , Chuck Lever , Trond Myklebust , Anna Schumaker , Michael =?utf-8?Q?Wei=C3=9F?= Subject: Re: [PATCH v4 2/3] fs/proc: apply the time namespace offset to /proc/stat btime In-Reply-To: <20201019195257.10728-3-michael.weiss@aisec.fraunhofer.de> References: <20201019195257.10728-1-michael.weiss@aisec.fraunhofer.de> <20201019195257.10728-3-michael.weiss@aisec.fraunhofer.de> Date: Mon, 26 Oct 2020 11:28:37 +0100 Message-ID: <87eell46y2.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 19 2020 at 21:52, Michael Wei=C3=9F wrote: > '/proc/stat' provides the field 'btime' which states the time stamp of > system boot in seconds. In case of time namespaces, the offset to the > boot time stamp was not applied earlier. However, in container > runtimes which utilize time namespaces to virtualize boottime of a > container, this leaks information about the host system boot time. Not sure if that qualifies as a leak. The point is that it confuses the tasks which are in a different time universe. Thanks, tglx