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_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 36B3CC73C46 for ; Tue, 9 Jul 2019 14:03:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0C7B420861 for ; Tue, 9 Jul 2019 14:03:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C7B420861 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=vivier.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50280 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hkqhw-0005PU-4Z for qemu-devel@archiver.kernel.org; Tue, 09 Jul 2019 10:03:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52698) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hkqgN-0004s9-4D for qemu-devel@nongnu.org; Tue, 09 Jul 2019 10:01:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hkqgI-0004m1-0m for qemu-devel@nongnu.org; Tue, 09 Jul 2019 10:01:23 -0400 Received: from indium.canonical.com ([91.189.90.7]:57698) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hkqgC-0004e7-8Q for qemu-devel@nongnu.org; Tue, 09 Jul 2019 10:01:15 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1hkqfu-0008BC-IM for ; Tue, 09 Jul 2019 14:00:54 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 6BD182E80CC for ; Tue, 9 Jul 2019 14:00:54 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Tue, 09 Jul 2019 13:47:08 -0000 From: Laurent Vivier To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: glaubitz laurent-vivier pmaydell X-Launchpad-Bug-Reporter: John Paul Adrian Glaubitz (glaubitz) X-Launchpad-Bug-Modifier: Laurent Vivier (laurent-vivier) References: <156262578461.2222.11301272429426949561.malonedeb@wampee.canonical.com> <156267456566.20622.9324953237843875366.malone@gac.canonical.com> Message-Id: X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="19007"; Instance="launchpad-lazr.conf" X-Launchpad-Hash: 46e39278709aa53100174fd2c1a8bd865b9c0e40 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 91.189.90.7 Subject: Re: [Qemu-devel] [Bug 1835839] Re: qemu-user: $0 incorrectly always reports absolute path X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1835839 <1835839@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Le 09/07/2019 =C3=A0 14:16, Peter Maydell a =C3=A9crit=C2=A0: > Is the proposed patch backwards compatible (ie "old QEMU binary works > with newer binfmt-misc registration" and "new QEMU binary works with > older binfmt-misc registration") ? Because binfmt-misc stuff is whole- > system but QEMU binaries are per-chroot, this kind of thing is awkward > to change if we don't have back-compat (and typically the kernel > semantics for these things often don't allow back-compat or any kind of > migration-path to the new better setup :-( ) > = If you don't enable the preserve-arg[0] flag, old and new QEMU will work. If you enable the flag, only new QEMU with -0/QEMU_ARGV0 will work. The best solution would be to force preserve-arg[0] with open-binary flag and rely on AT_FDEXEC to detect the binfmt-misc environment, but this breaks compatibility with existing environment and old QEMU. Regarding the "binfmt-misc stuff is whole-system" problem, I've proposed months ago a kernel based solution [1] to have a configuration per namespace (chroot), but no one seems really interested (I think maintainer is afraid by potential security issues). [1] ns: introduce binfmt_misc namespace https://patchwork.kernel.org/cover/10634807/ -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1835839 Title: qemu-user: $0 incorrectly always reports absolute path Status in QEMU: New Bug description: We just ran into an issue with the Perl package on Debian/m68k when being built with qemu-user [1]. The problem can be boiled down to qemu-user always reporting absolute paths for the shell variable $0 no matter on how the command was invoked. A simple reproducer is this: On normal system (no emulation): root@nofan:~> sh -c 'echo $0' sh root@nofan:~> On qemu-user: (sid-m68k-sbuild)root@nofan:/# sh -c 'echo $0' /bin/sh (sid-m68k-sbuild)root@nofan:/# > [1] https://lists.debian.org/debian-68k/2019/07/msg00007.html To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1835839/+subscriptions