[Qemu-devel] [PATCH] hw/pci-host: Use object_initialize_child for correct reference counting

[Thomas Huth <thuth@redhat.com>]

Both functions, object_initialize() and object_property_add_child() increase
the reference counter of the new object, so one of the references has to be
dropped afterwards to get the reference counting right. Otherwise the child
object might not be properly cleaned up when the parent gets destroyed.
Some functions of the pci-host devices miss to drop one of the references.
Fix it by using object_initialize_child() instead, which takes care of
calling object_initialize(), object_property_add_child() and object_unref()
in the right order.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 hw/pci-host/designware.c  | 4 ++--
 hw/pci-host/gpex.c        | 5 +++--
 hw/pci-host/q35.c         | 4 ++--
 hw/pci-host/xilinx-pcie.c | 4 ++--
 4 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/hw/pci-host/designware.c b/hw/pci-host/designware.c
index 29ea313..64ad21d 100644
--- a/hw/pci-host/designware.c
+++ b/hw/pci-host/designware.c
@@ -721,8 +721,8 @@ static void designware_pcie_host_init(Object *obj)
     DesignwarePCIEHost *s = DESIGNWARE_PCIE_HOST(obj);
     DesignwarePCIERoot *root = &s->root;
 
-    object_initialize(root, sizeof(*root), TYPE_DESIGNWARE_PCIE_ROOT);
-    object_property_add_child(obj, "root", OBJECT(root), NULL);
+    object_initialize_child(obj, "root",  root, sizeof(*root),
+                            TYPE_DESIGNWARE_PCIE_ROOT, &error_abort, NULL);
     qdev_prop_set_int32(DEVICE(root), "addr", PCI_DEVFN(0, 0));
     qdev_prop_set_bit(DEVICE(root), "multifunction", false);
 }
diff --git a/hw/pci-host/gpex.c b/hw/pci-host/gpex.c
index 2583b15..1bafffc 100644
--- a/hw/pci-host/gpex.c
+++ b/hw/pci-host/gpex.c
@@ -29,6 +29,7 @@
  * http://www.firmware.org/1275/practice/imap/imap0_9d.pdf
  */
 #include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "hw/hw.h"
 #include "hw/pci-host/gpex.h"
 
@@ -120,8 +121,8 @@ static void gpex_host_initfn(Object *obj)
     GPEXHost *s = GPEX_HOST(obj);
     GPEXRootState *root = &s->gpex_root;
 
-    object_initialize(root, sizeof(*root), TYPE_GPEX_ROOT_DEVICE);
-    object_property_add_child(obj, "gpex_root", OBJECT(root), NULL);
+    object_initialize_child(obj, "gpex_root",  root, sizeof(*root),
+                            TYPE_GPEX_ROOT_DEVICE, &error_abort, NULL);
     qdev_prop_set_int32(DEVICE(root), "addr", PCI_DEVFN(0, 0));
     qdev_prop_set_bit(DEVICE(root), "multifunction", false);
 }
diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index 7b871b5..960939f 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -216,8 +216,8 @@ static void q35_host_initfn(Object *obj)
     memory_region_init_io(&phb->data_mem, obj, &pci_host_data_le_ops, phb,
                           "pci-conf-data", 4);
 
-    object_initialize(&s->mch, sizeof(s->mch), TYPE_MCH_PCI_DEVICE);
-    object_property_add_child(OBJECT(s), "mch", OBJECT(&s->mch), NULL);
+    object_initialize_child(OBJECT(s), "mch",  &s->mch, sizeof(s->mch),
+                            TYPE_MCH_PCI_DEVICE, &error_abort, NULL);
     qdev_prop_set_int32(DEVICE(&s->mch), "addr", PCI_DEVFN(0, 0));
     qdev_prop_set_bit(DEVICE(&s->mch), "multifunction", false);
     /* mch's object_initialize resets the default value, set it again */
diff --git a/hw/pci-host/xilinx-pcie.c b/hw/pci-host/xilinx-pcie.c
index 60309af..f82d3f3 100644
--- a/hw/pci-host/xilinx-pcie.c
+++ b/hw/pci-host/xilinx-pcie.c
@@ -149,8 +149,8 @@ static void xilinx_pcie_host_init(Object *obj)
     XilinxPCIEHost *s = XILINX_PCIE_HOST(obj);
     XilinxPCIERoot *root = &s->root;
 
-    object_initialize(root, sizeof(*root), TYPE_XILINX_PCIE_ROOT);
-    object_property_add_child(obj, "root", OBJECT(root), NULL);
+    object_initialize_child(obj, "root",  root, sizeof(*root),
+                            TYPE_XILINX_PCIE_ROOT, NULL);
     qdev_prop_set_int32(DEVICE(root), "addr", PCI_DEVFN(0, 0));
     qdev_prop_set_bit(DEVICE(root), "multifunction", false);
 }
-- 
1.8.3.1