From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:36244)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1bn1mW-0005i6-BK
	for qemu-devel@nongnu.org; Thu, 22 Sep 2016 07:03:09 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1bn1mP-0006zG-E7
	for qemu-devel@nongnu.org; Thu, 22 Sep 2016 07:03:07 -0400
Received: from mx1.redhat.com ([209.132.183.28]:41008)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1bn1mP-0006z1-7c
	for qemu-devel@nongnu.org; Thu, 22 Sep 2016 07:03:01 -0400
From: Markus Armbruster <armbru@redhat.com>
References: <20160921103629.6410-1-marcandre.lureau@redhat.com>
	<20160921103629.6410-2-marcandre.lureau@redhat.com>
	<87bmzhz5jx.fsf@dusky.pond.sub.org>
	<1730633132.491556.1474474072544.JavaMail.zimbra@redhat.com>
Date: Thu, 22 Sep 2016 13:02:57 +0200
In-Reply-To: <1730633132.491556.1474474072544.JavaMail.zimbra@redhat.com>
	(=?utf-8?Q?=22Marc-Andr=C3=A9?= Lureau"'s message of "Wed, 21 Sep 2016
	12:07:52 -0400 (EDT)")
Message-ID: <87twd8mc2m.fsf@dusky.pond.sub.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Subject: Re: [Qemu-devel] [PATCH 1/3] qapi: return a 'missing parameter'
 error
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: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau <mlureau@redhat.com>
Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau <marcandre.lureau@redhat.com>, berto@igalia.com, qemu-devel@nongnu.org, Eric Blake <eblake@redhat.com>

Marc-Andr=C3=A9 Lureau <mlureau@redhat.com> writes:

> Hi
>
> ----- Original Message -----
>> Aha, we got a different bug fix!  The old code fails to fail when the
>> parameter doesn't exist.  Instead, it sets *obj =3D NULL, which seems ve=
ry
>> likely to crash QEMU.  Let me try... yup:
>>=20
>>     { "execute": "object-add",
>>       "arguments": { "qom-type": "memory-backend-file", "id": "foo" } }
>>=20
>> Kills QEMU with "qemu/qom/object_interfaces.c:115: user_creatable_add_ty=
pe:
>> Assertion `qdict' failed."
>>=20
>> Either fix this in a separate patch before this one, or cover it in this
>> one's commit message.  Your choice.
>>=20
>> A separate patch might be usable for qemu-stable.
>
> It looks to me that this is a different bug.=20
>
> visit_type_q_obj_object_add_arg_members() doesn't call visit_type_any() i=
f "props" is missing (it's optionnal).
>
> And arg is zero'ed in qmp-marshal, and the assert() was added in ad739706=
bbadee49. I am trying to fix that regression.

Okay, that's *also* a bug.

For the bug I spotted, try

  { "execute": "qom-set",
    "arguments": { "path": "/machine", "property": "rtc-time" } }

Trips assert(!err !=3D !*obj) in its caller visit_type_any().

[...]