| Message ID | 1470134960-87851-1-git-send-email-imammedo@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 02/08/2016 12:49, Igor Mammedov wrote: > Since 69382d8b (qdev: Fix object reference leak in case device.realize() > fails), object_property_set_bool releases the device object > in case realize's failed and device hasn't explicitly assigned > parent. It happens due to object_unparent() on error handling > path releases not only implicitly set parent but also calls > device_unparent() which releases the remaining reference hold > buy parent bus. > > qdev_try_create() created device has only 1 reference hold by > parent bus which makes impossible to unparent/re-parent object > without destroying it. > > Fix it by making caller of qdev_try_create()/qdev_init_nofail() > own a reference from object_new() until qdev_init_nofail() is > successfully executed so that uparenting won't destroy device > until caller owns pointer returned by qdev_try_create(). Your patch is indeed nicer in theory, but in practice I'm not sure that there are no occurrences of object_new + qdev_init_nofail, or qdev_try_create + object_property_set_bool. These would be broken, so I'm going with Fam's. Paolo > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > --- > hw/core/qdev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c > index ee4a083..0139d67 100644 > --- a/hw/core/qdev.c > +++ b/hw/core/qdev.c > @@ -151,7 +151,6 @@ DeviceState *qdev_try_create(BusState *bus, const char *type) > } > > qdev_set_parent_bus(dev, bus); > - object_unref(OBJECT(dev)); > return dev; > } > > @@ -360,6 +359,7 @@ void qdev_init_nofail(DeviceState *dev) > object_get_typename(OBJECT(dev))); > exit(1); > } > + object_unref(OBJECT(dev)); > } > > void qdev_machine_creation_done(void) >
diff --git a/hw/core/qdev.c b/hw/core/qdev.c index ee4a083..0139d67 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -151,7 +151,6 @@ DeviceState *qdev_try_create(BusState *bus, const char *type) } qdev_set_parent_bus(dev, bus); - object_unref(OBJECT(dev)); return dev; } @@ -360,6 +359,7 @@ void qdev_init_nofail(DeviceState *dev) object_get_typename(OBJECT(dev))); exit(1); } + object_unref(OBJECT(dev)); } void qdev_machine_creation_done(void)
Since 69382d8b (qdev: Fix object reference leak in case device.realize() fails), object_property_set_bool releases the device object in case realize's failed and device hasn't explicitly assigned parent. It happens due to object_unparent() on error handling path releases not only implicitly set parent but also calls device_unparent() which releases the remaining reference hold buy parent bus. qdev_try_create() created device has only 1 reference hold by parent bus which makes impossible to unparent/re-parent object without destroying it. Fix it by making caller of qdev_try_create()/qdev_init_nofail() own a reference from object_new() until qdev_init_nofail() is successfully executed so that uparenting won't destroy device until caller owns pointer returned by qdev_try_create(). Signed-off-by: Igor Mammedov <imammedo@redhat.com> --- hw/core/qdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)