From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53289) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fe5v7-0003UA-E2 for qemu-devel@nongnu.org; Fri, 13 Jul 2018 17:48:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fe5v6-0006MG-HA for qemu-devel@nongnu.org; Fri, 13 Jul 2018 17:48:09 -0400 Date: Fri, 13 Jul 2018 18:48:01 -0300 From: Eduardo Habkost Message-ID: <20180713214801.GX31657@localhost.localdomain> References: <1531470464-21522-1-git-send-email-thuth@redhat.com> <1531470464-21522-6-git-send-email-thuth@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1531470464-21522-6-git-send-email-thuth@redhat.com> Subject: Re: [Qemu-devel] [PATCH v2 05/16] hw/cpu/a15mpcore: Fix introspection problem with the a15mpcore_priv device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: qemu-devel@nongnu.org, Peter Maydell , Paolo Bonzini , qemu-arm@nongnu.org, Markus Armbruster , Beniamino Galvani , Subbaraya Sundeep , Alistair Francis , "Edgar E. Iglesias" , Andreas =?iso-8859-1?Q?F=E4rber?= On Fri, Jul 13, 2018 at 10:27:33AM +0200, Thomas Huth wrote: > There is a memory management problem when introspecting the a15mpcore_priv > device. It can be seen with valgrind when running QEMU like this: > > echo "{'execute':'qmp_capabilities'} {'execute':'device-list-properties'," \ > "'arguments':{'typename':'a15mpcore_priv'}}"\ > "{'execute': 'human-monitor-command', " \ > "'arguments': {'command-line': 'info qtree'}}" | \ > valgrind -q aarch64-softmmu/qemu-system-aarch64 -M none,accel=qtest -qmp stdio > {"QMP": {"version": {"qemu": {"micro": 50, "minor": 12, "major": 2}, > "package": "build-all"}, "capabilities": []}} > {"return": {}} > {"return": [{"name": "num-cpu", "type": "uint32"}, {"name": "num-irq", > "type": "uint32"}, {"name": "a15mp-priv-container[0]", "type": > "child"}]} > ==24978== Invalid read of size 8 > ==24978== at 0x618EBA: qdev_print (qdev-monitor.c:686) > ==24978== by 0x618EBA: qbus_print (qdev-monitor.c:719) > [...] > > Use the new sysbus_init_child_obj() function to make sure that we get > the reference counting of the child objects right. > > Signed-off-by: Thomas Huth > --- > hw/cpu/a15mpcore.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/hw/cpu/a15mpcore.c b/hw/cpu/a15mpcore.c > index bc05152..43c1079 100644 > --- a/hw/cpu/a15mpcore.c > +++ b/hw/cpu/a15mpcore.c > @@ -35,15 +35,13 @@ static void a15mp_priv_initfn(Object *obj) > { > SysBusDevice *sbd = SYS_BUS_DEVICE(obj); > A15MPPrivState *s = A15MPCORE_PRIV(obj); > - DeviceState *gicdev; > > memory_region_init(&s->container, obj, "a15mp-priv-container", 0x8000); > sysbus_init_mmio(sbd, &s->container); > > - object_initialize(&s->gic, sizeof(s->gic), gic_class_name()); > - gicdev = DEVICE(&s->gic); > - qdev_set_parent_bus(gicdev, sysbus_get_default()); > - qdev_prop_set_uint32(gicdev, "revision", 2); > + sysbus_init_child_obj(obj, "gic", &s->gic, sizeof(s->gic), > + gic_class_name()); > + qdev_prop_set_uint32(DEVICE(&s->gic), "revision", 2); I assume qdev_set_parent_bus() won't trigger any code that looks at "revision", so the prop_set/set_parent_bus ordering change won't matter. Reviewed-by: Eduardo Habkost -- Eduardo