[Qemu-devel] [PATCH v4 2/8] qom: detect bad reentrance during object_class_foreach

[Alexey Kardashevskiy <aik@ozlabs.ru>]

From: Hervé Poussineau <hpoussin@reactos.org>

We should not modify the type hash table while it is being iterated on.
Assert that it does not happen.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v4:
* rename: @enumerating -> @enumerating_types
* @enumerating_types is static and does not require initialization to "false"
---
 qom/object.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/qom/object.c b/qom/object.c
index 3a43186..937af00 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -78,8 +78,10 @@ static GHashTable *type_table_get(void)
     return type_table;
 }
 
+static bool enumerating_types;
 static void type_table_add(TypeImpl *ti)
 {
+    assert(!enumerating_types);
     g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
 }
 
@@ -666,7 +668,9 @@ void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 {
     OCFData data = { fn, implements_type, include_abstract, opaque };
 
+    enumerating_types = true;
     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
+    enumerating_types = false;
 }
 
 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
-- 
1.8.4.rc4