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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT 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 6F2DEC43143 for ; Tue, 2 Oct 2018 10:21:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4098720878 for ; Tue, 2 Oct 2018 10:21:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4098720878 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=vivier.eu 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 S1727362AbeJBREG (ORCPT ); Tue, 2 Oct 2018 13:04:06 -0400 Received: from mout.kundenserver.de ([212.227.126.131]:51621 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726244AbeJBREF (ORCPT ); Tue, 2 Oct 2018 13:04:05 -0400 Received: from localhost.localdomain ([78.238.229.36]) by mrelayeu.kundenserver.de (mreue011 [212.227.15.167]) with ESMTPSA (Nemesis) id 1M1q8m-1g9Uij13X6-002KQI; Tue, 02 Oct 2018 12:21:01 +0200 Received: from localhost.localdomain ([78.238.229.36]) by mrelayeu.kundenserver.de (mreue011 [212.227.15.167]) with ESMTPSA (Nemesis) id 1M1q8m-1g9Uij13X6-002KQI; Tue, 02 Oct 2018 12:21:01 +0200 From: Laurent Vivier To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov , Andrei Vagin , Eric Biederman , Alexander Viro , James Bottomley , containers@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, Laurent Vivier Subject: [RFC v2 v2 0/1] ns: introduce binfmt_misc namespace Date: Tue, 2 Oct 2018 12:20:53 +0200 Message-Id: <20181002102054.13245-1-laurent@vivier.eu> X-Mailer: git-send-email 2.17.1 X-Provags-ID: V03:K1:jMg8MAk4HUS6vowL+GJRyitwnPutqRANjO1x3UzgEWhtiNjLct8 76imB0V5h+HnKFG3nMDCO3Ud0D061hRsOoY3TLKEF+dHQhaa6ykAgPWrhy+bv1raiKqCY23 7sCSGF2y3KnOpLlR0PYsB7WWPqy/gN8/jNhTTcyfzn8wlmcRgUiUn7TAhbhEw7Rk9QNXRgA tz2YWaWo81vumWz+/Qxqw== X-UI-Out-Filterresults: notjunk:1;V01:K0:1EplV7zUx9Y=:LXcJxvoKvIkzZSd9cN5jBB KxsFqRkp+HGJqajPQJkyuJFBXlPuuAvwuSW4NqS8WrSUisYC2EAg9oRdQZFg3k3RKwG5pURzZ K6Y9dmfbDrvXpUHg93jqn86QJJm8HpLM96WHoYzd78p/yf2tKVZsSPT4GuQcTRkrhzBY6ZS7B ID4n0XW5hR+lMByDgJwzP/BrElJ6sNLrUwGzchF6Wh7kCGeqcPdRDukbZjwwPzogLBmGB/2dx jdYbwRtZFKOUorVOOMapIVL5qV5HPDSlbCE5uuzTpKXJYXxun/lPWL3wN+NB1Qletfmw6eGGF ejPn3E4QzHyccXLRZsO3BxCEqJpOGSp4CkgL5Ma0u4B0kuPB79vSZ4IuG+FqN/+ESInmnTZzj v5/9zjPvJ/XOqXjySvjOzMfHj9Nc/U3F2gSLYuVEr93RdqvoNZbEuWqLBGl6N9ta7hK7ZsEOy rit6pNgiAepEQMbsJzoljXhHsLZL9zakWArWP3ru5w3I/ER6BN2Y8QOQeMBqpEuWKBQyctNgJ QMEmoU3EalseZvcT+7qta2YSK700bpqyXOQm+eudO+ku0vbrxBlJfZRvNfu3PmnQh+DtDqsPA bumyRYq1JpbAxERmoNA9GHtm0N38GxwaaZGGGYQplMDVwEWuYNtWZjPw7KBwccp975Z28x5Y3 p5paWhbBygoCpWaeodPkLGLC06h59pawGl8qKgb0xN26Ft00EJ8kxXPVsntfJygG6NZU= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v2: no new namespace, binfmt_misc data are now part of the mount namespace I put this in mount namespace instead of user namespace because the mount namespace is already needed and I don't want to force to have the user namespace for that. As this is a filesystem, it seems logic to have it here. This allows to define a new interpreter for each new container. But the main goal is to be able to chroot to a directory using a binfmt_misc interpreter without being root. I have a modified version of unshare at: git@github.com:vivier/util-linux.git branch unshare-chroot with some new options to unshare binfmt_misc namespace and to chroot to a directory. If you have a directory /chroot/powerpc/jessie containing debian for powerpc binaries and a qemu-ppc interpreter, you can do for instance: $ uname -a Linux fedora28-wor-2 4.19.0-rc5+ #18 SMP Mon Oct 1 00:32:34 CEST 2018 x86_64 x86_64 x86_64 GNU/Linux $ ./unshare --map-root-user --fork --pid \ --load-interp ":qemu-ppc:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x14:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/qemu-ppc:OC" \ --root=/chroot/powerpc/jessie /bin/bash -l # uname -a Linux fedora28-wor-2 4.19.0-rc5+ #18 SMP Mon Oct 1 00:32:34 CEST 2018 ppc GNU/Linux # id uid=0(root) gid=0(root) groups=0(root),65534(nogroup) # ls -l total 5940 drwxr-xr-x. 2 nobody nogroup 4096 Aug 12 00:58 bin drwxr-xr-x. 2 nobody nogroup 4096 Jun 17 20:26 boot drwxr-xr-x. 4 nobody nogroup 4096 Aug 12 00:08 dev drwxr-xr-x. 42 nobody nogroup 4096 Sep 28 07:25 etc drwxr-xr-x. 3 nobody nogroup 4096 Sep 28 07:25 home drwxr-xr-x. 9 nobody nogroup 4096 Aug 12 00:58 lib drwxr-xr-x. 2 nobody nogroup 4096 Aug 12 00:08 media drwxr-xr-x. 2 nobody nogroup 4096 Aug 12 00:08 mnt drwxr-xr-x. 3 nobody nogroup 4096 Aug 12 13:09 opt dr-xr-xr-x. 143 nobody nogroup 0 Sep 30 23:02 proc -rwxr-xr-x. 1 nobody nogroup 6009712 Sep 28 07:22 qemu-ppc drwx------. 3 nobody nogroup 4096 Aug 12 12:54 root drwxr-xr-x. 3 nobody nogroup 4096 Aug 12 00:08 run drwxr-xr-x. 2 nobody nogroup 4096 Aug 12 00:58 sbin drwxr-xr-x. 2 nobody nogroup 4096 Aug 12 00:08 srv drwxr-xr-x. 2 nobody nogroup 4096 Apr 6 2015 sys drwxrwxrwt. 2 nobody nogroup 4096 Sep 28 10:31 tmp drwxr-xr-x. 10 nobody nogroup 4096 Aug 12 00:08 usr drwxr-xr-x. 11 nobody nogroup 4096 Aug 12 00:08 var If you want to use the qemu binary provided by your distro, you can use --load-interp ":qemu-ppc:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x14:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/bin/qemu-ppc-static:OCF" With the 'F' flag, qemu-ppc-static will be then loaded from the main root filesystem before switching to the chroot. Laurent Vivier (1): ns: add binfmt_misc to the mount namespace fs/binfmt_misc.c | 50 +++++++++++++++++++++++++----------------------- fs/mount.h | 8 ++++++++ fs/namespace.c | 6 ++++++ 3 files changed, 40 insertions(+), 24 deletions(-) -- 2.17.1