object: fix OBJ_PROP_LINK_UNREF_ON_RELEASE ambivalence

A link property can be set during creation, with
object_property_add_link() and later with object_property_set_link().

add_link() doesn't add a reference to the target object, while
set_link() does.

Furthemore, OBJ_PROP_LINK_UNREF_ON_RELEASE flags, set during add_link,
says whether a reference must be released when the property is destroyed.
This can lead to leaks if the property was later set_link(), as the
added reference is never released.

Instead, rename OBJ_PROP_LINK_UNREF_ON_RELEASE to OBJ_PROP_LINK_STRONG
and use that has an indication on how the link handle reference
management in set_link().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20180531195119.22021-3-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
index 9b48103574..401a328e27 100644
--- a/hw/dma/xilinx_axidma.c
+++ b/hw/dma/xilinx_axidma.c
@@ -525,12 +525,12 @@ static void xilinx_axidma_realize(DeviceState *dev, Error **errp)
     object_property_add_link(OBJECT(ds), "dma", TYPE_XILINX_AXI_DMA,
                              (Object **)&ds->dma,
                              object_property_allow_set_link,
-                             OBJ_PROP_LINK_UNREF_ON_RELEASE,
+                             OBJ_PROP_LINK_STRONG,
                              &local_err);
     object_property_add_link(OBJECT(cs), "dma", TYPE_XILINX_AXI_DMA,
                              (Object **)&cs->dma,
                              object_property_allow_set_link,
-                             OBJ_PROP_LINK_UNREF_ON_RELEASE,
+                             OBJ_PROP_LINK_STRONG,
                              &local_err);
     if (local_err) {
         goto xilinx_axidma_realize_fail;