From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:55916)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <ehabkost@redhat.com>) id 1Zgepr-0002Di-Rq
	for qemu-devel@nongnu.org; Mon, 28 Sep 2015 16:15:44 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <ehabkost@redhat.com>) id 1Zgepn-0007Jx-Hq
	for qemu-devel@nongnu.org; Mon, 28 Sep 2015 16:15:43 -0400
Date: Mon, 28 Sep 2015 17:15:33 -0300
From: Eduardo Habkost <ehabkost@redhat.com>
Message-ID: <20150928201533.GJ4130@thinpad.lan.raisama.net>
References: <1443470907-32335-1-git-send-email-armbru@redhat.com>
	<1443470907-32335-7-git-send-email-armbru@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1443470907-32335-7-git-send-email-armbru@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v4 6/7] qdev: Protect
 device-list-properties against broken devices
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Markus Armbruster <armbru@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>, Anthony Green <green@moxielogic.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, qemu-devel@nongnu.org, Blue Swirl <blauwirbel@gmail.com>, Max Filippov <jcmvbkbc@gmail.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Guan Xuetao <gxt@mprc.pku.edu.cn>, Jia Liu <proljc@gmail.com>, Alexander Graf <agraf@suse.de>, Christian Borntraeger <borntraeger@de.ibm.com>, Leon Alrae <leon.alrae@imgtec.com>, thuth@redhat.com, qemu-stable@nongnu.org, stefanha@redhat.com, Cornelia Huck <cornelia.huck@de.ibm.com>, Richard Henderson <rth@twiddle.net>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Michael Walle <michael@walle.cc>, qemu-ppc@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>, afaerber@suse.de, Aurelien Jarno <aurelien@aurel32.net>

On Mon, Sep 28, 2015 at 10:08:26PM +0200, Markus Armbruster wrote:
> Several devices don't survive object_unref(object_new(T)): they crash
> or hang during cleanup, or they leave dangling pointers behind.
> 
> This breaks at least device-list-properties, because
> qmp_device_list_properties() needs to create a device to find its
> properties.  Broken in commit f4eb32b "qmp: show QOM properties in
> device-list-properties", v2.1.  Example reproducer:
> 
>     $ qemu-system-aarch64 -nodefaults -display none -machine none -S -qmp stdio
>     {"QMP": {"version": {"qemu": {"micro": 50, "minor": 4, "major": 2}, "package": ""}, "capabilities": []}}
>     { "execute": "qmp_capabilities" }
>     {"return": {}}
>     { "execute": "device-list-properties", "arguments": { "typename": "pxa2xx-pcmcia" } }
>     qemu-system-aarch64: /home/armbru/work/qemu/memory.c:1307: memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed.
>     Aborted (core dumped)
>     [Exit 134 (SIGABRT)]
> 
> Unfortunately, I can't fix the problems in these devices right now.
> Instead, add DeviceClass member cannot_even_create_with_object_new_yet
> to mark them:
[...]
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

-- 
Eduardo