[PULL,14/55] qom: Assert that objects being destroyed have no parent

Commit Message

Paolo Bonzini Dec. 21, 2020, 2:44 p.m. UTC

From: Eduardo Habkost <[e-mail]>

QOM reference counting bugs are often hard to detect, but there's
one kind of bug that's easier: if we are freeing an object but is
still attached to a parent, it means the reference count is wrong
(because the parent always hold a reference to their children).

Add an assertion to make sure we detect those cases.

Signed-off-by: Eduardo Habkost <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>
---
 qom/object.c | 1 +
 1 file changed, 1 insertion(+)

Patch

diff --git a/qom/object.c b/qom/object.c
index f2ae6e6b2a..5cfed6d7c6 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -685,6 +685,7 @@  static void object_finalize(void *data)
     object_deinit(obj, ti);
 
     g_assert(obj->ref == 0);
+    g_assert(obj->parent == NULL);
     if (obj->free) {
         obj->free(obj);
     }