commit 95916abcf428fb03644468c7fbce64356c6483c0
author Peter Crosthwaite <peter.crosthwaite@xilinx.com> Wed May 22 11:19:16 2013 +1000
committer Anthony Liguori <aliguori@us.ibm.com> Wed May 22 07:40:09 2013 -0500
tree c255077ef80570c05d0b2186f5c595addfecf962
parent 3d1bba20913356ff4f8ff2c38519f10c5f4b77e6

qom/object: Don't poll cast cache for NULL objects

object_dynamic_cast_assert used to be tolerant of NULL objects and not
assert. It's clear from the implementation that this is the expected
behavior.

The preceding check of the cast cache dereferences obj however causing
a segfault. Fix by conditionalizing the cast cache logic on obj being
non-null.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Message-id: 8e2bef6a55753869c50bfa32226f7fcf0439ca62.1369183592.git.peter.crosthwaite@xilinx.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

qom/object.c

diff --git a/qom/object.c b/qom/object.c
index ec88231..803b94b 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -442,7 +442,7 @@
     int i;
     Object *inst;
 
-    for (i = 0; i < OBJECT_CLASS_CAST_CACHE; i++) {
+    for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
         if (obj->class->cast_cache[i] == typename) {
             goto out;
         }
@@ -458,7 +458,7 @@
 
     assert(obj == inst);
 
-    if (obj == inst) {
+    if (obj && obj == inst) {
         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
             obj->class->cast_cache[i - 1] = obj->class->cast_cache[i];
         }