hw/ppc/pnv: Use object_initialize_child for correct reference counting

As explained in commit aff39be0ed97:

  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 will not be properly
  cleaned up when the parent gets destroyed.
  Thus let's use now object_initialize_child() instead to get the
  reference counting here right.

This patch was generated using the following Coccinelle script
(with a bit of manual fix-up for overly long lines):

 @use_object_initialize_child@
 expression parent_obj;
 expression child_ptr;
 expression child_name;
 expression child_type;
 expression child_size;
 expression errp;
 @@
 (
 -   object_initialize(child_ptr, child_size, child_type);
 +   object_initialize_child(parent_obj, child_name,  child_ptr, child_size,
 +                           child_type, &error_abort, NULL);
     ... when != parent_obj
 -   object_property_add_child(parent_obj, child_name, OBJECT(child_ptr), NULL);
     ...
?-   object_unref(OBJECT(child_ptr));
 |
 -   object_initialize(child_ptr, child_size, child_type);
 +   object_initialize_child(parent_obj, child_name,  child_ptr, child_size,
 +                            child_type, errp, NULL);
     ... when != parent_obj
 -   object_property_add_child(parent_obj, child_name, OBJECT(child_ptr), errp);
     ...
?-   object_unref(OBJECT(child_ptr));
 )

While the object_initialize() function doesn't take an
'Error *errp' argument, the object_initialize_child() does.
Since this code is used when a machine is created (and is not
yet running), we deliberately choose to use the &error_abort
argument instead of ignoring errors if an object creation failed.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Inspired-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190507163416.24647-2-philmd@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index dfb4ea5742c1dd37abbc53809cec56d8bcaff239..31aa20ee25d0f2d205e8879d953514fbdbe1d0f7 100644 (file)
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -994,14 +994,12 @@ static void pnv_chip_quad_realize(Pnv9Chip *chip9, Error **errp)
         PnvCore *pnv_core = PNV_CORE(chip->cores + (i * 4) * typesize);
         int core_id = CPU_CORE(pnv_core)->core_id;
 
-        object_initialize(eq, sizeof(*eq), TYPE_PNV_QUAD);
         snprintf(eq_name, sizeof(eq_name), "eq[%d]", core_id);
+        object_initialize_child(OBJECT(chip), eq_name, eq, sizeof(*eq),
+                                TYPE_PNV_QUAD, &error_fatal, NULL);
 
-        object_property_add_child(OBJECT(chip), eq_name, OBJECT(eq),
-                                  &error_fatal);
         object_property_set_int(OBJECT(eq), core_id, "id", &error_fatal);
         object_property_set_bool(OBJECT(eq), true, "realized", &error_fatal);
-        object_unref(OBJECT(eq));
 
         pnv_xscom_add_subregion(chip, PNV9_XSCOM_EQ_BASE(eq->id),
                                 &eq->xscom_regs);
@@ -1165,10 +1163,9 @@ static void pnv_chip_core_realize(PnvChip *chip, Error **errp)
             continue;
         }
 
-        object_initialize(pnv_core, typesize, typename);
         snprintf(core_name, sizeof(core_name), "core[%d]", core_hwid);
-        object_property_add_child(OBJECT(chip), core_name, OBJECT(pnv_core),
-                                  &error_fatal);
+        object_initialize_child(OBJECT(chip), core_name, pnv_core, typesize,
+                                typename, &error_fatal, NULL);
         object_property_set_int(OBJECT(pnv_core), smp_threads, "nr-threads",
                                 &error_fatal);
         object_property_set_int(OBJECT(pnv_core), core_hwid,
@@ -1180,7 +1177,6 @@ static void pnv_chip_core_realize(PnvChip *chip, Error **errp)
                                        OBJECT(chip), &error_fatal);
         object_property_set_bool(OBJECT(pnv_core), true, "realized",
                                  &error_fatal);
-        object_unref(OBJECT(pnv_core));
 
         /* Each core has an XSCOM MMIO region */
         if (!pnv_chip_is_power9(chip)) {