From patchwork Tue Jul 25 15:09:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?THVrw6HFoSBEb2t0b3I=?= X-Patchwork-Id: 793478 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xH1wD6vpLz9rxm for ; Wed, 26 Jul 2017 01:13:32 +1000 (AEST) Received: from localhost ([::1]:33133 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da1Wc-0002AJ-Aw for incoming@patchwork.ozlabs.org; Tue, 25 Jul 2017 11:13:30 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45842) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da1TT-0008Sa-MX for qemu-devel@nongnu.org; Tue, 25 Jul 2017 11:10:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1da1TS-0006kz-PE for qemu-devel@nongnu.org; Tue, 25 Jul 2017 11:10:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42824) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1da1TS-0006kW-Iv for qemu-devel@nongnu.org; Tue, 25 Jul 2017 11:10:14 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AC706C058EDD; Tue, 25 Jul 2017 15:10:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com AC706C058EDD Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=ldoktor@redhat.com Received: from localhost.localdomain.com (ovpn-204-88.brq.redhat.com [10.40.204.88]) by smtp.corp.redhat.com (Postfix) with ESMTP id 292D56061D; Tue, 25 Jul 2017 15:10:09 +0000 (UTC) From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Doktor?= To: qemu-devel@nongnu.org Date: Tue, 25 Jul 2017 17:09:43 +0200 Message-Id: <20170725150951.16038-3-ldoktor@redhat.com> In-Reply-To: <20170725150951.16038-1-ldoktor@redhat.com> References: <20170725150951.16038-1-ldoktor@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 25 Jul 2017 15:10:13 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 02/10] qemu|qtest: Avoid dangerous arguments X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ldoktor@redhat.com, famz@redhat.com, ehabkost@redhat.com, armbru@redhat.com, apahim@redhat.com, f4bug@amsat.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The list object is mutable in python and potentially might modify other object's arguments when used as default argument. Reproducer: >>> vm1 = QEMUMachine("qemu") >>> vm2 = QEMUMachine("qemu") >>> vm1._wrapper.append("foo") >>> print vm2._wrapper ['foo'] In this case the `args` is actually copied so it would be safe to keep it, but it's not a good practice to keep it. The same issue applies in inherited qtest module. Signed-off-by: Lukáš Doktor Reviewed-by: Eduardo Habkost Reviewed-by: John Snow --- scripts/qemu.py | 6 +++++- scripts/qtest.py | 2 +- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/scripts/qemu.py b/scripts/qemu.py index 191c916..66fd863 100644 --- a/scripts/qemu.py +++ b/scripts/qemu.py @@ -23,7 +23,7 @@ import qmp.qmp class QEMUMachine(object): '''A QEMU VM''' - def __init__(self, binary, args=[], wrapper=[], name=None, + def __init__(self, binary, args=None, wrapper=None, name=None, test_dir="/var/tmp", monitor_address=None, socket_scm_helper=None, debug=False): ''' @@ -39,6 +39,10 @@ class QEMUMachine(object): @param debug: enable debug mode (forwarded to QMP helper and such) @note: Qemu process is not started until launch() is used. ''' + if args is None: + args = [] + if wrapper is None: + wrapper = [] if name is None: name = "qemu-%d" % os.getpid() if monitor_address is None: diff --git a/scripts/qtest.py b/scripts/qtest.py index d5aecb5..ab183c0 100644 --- a/scripts/qtest.py +++ b/scripts/qtest.py @@ -79,7 +79,7 @@ class QEMUQtestProtocol(object): class QEMUQtestMachine(qemu.QEMUMachine): '''A QEMU VM''' - def __init__(self, binary, args=[], name=None, test_dir="/var/tmp", + def __init__(self, binary, args=None, name=None, test_dir="/var/tmp", socket_scm_helper=None): if name is None: name = "qemu-%d" % os.getpid()