Don't use WellKnownClasses in ReferenceProcessor's GetSlowPathFlagOffset.

It may not be initialized at the point the reference processor is
running.

Test: test.py
Change-Id: I21adb9aea1d99b2512d424a6a9982546fef08f06

1 files changed, 4 insertions, 1 deletions

diff --git a/runtime/gc/reference_processor.cc b/runtime/gc/reference_processor.cc
index 2621629bb8..6420fbbff6 100644
--- a/runtime/gc/reference_processor.cc
+++ b/runtime/gc/reference_processor.cc
@@ -54,8 +54,11 @@ ReferenceProcessor::ReferenceProcessor()
 static inline MemberOffset GetSlowPathFlagOffset(ObjPtr<mirror::Class> reference_class)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   DCHECK(reference_class == GetClassRoot<mirror::Reference>());
-  ArtField* field = WellKnownClasses::java_lang_ref_Reference_slowPathEnabled;
+  // Don't use WellKnownClasses here as it may not be initialized at the point
+  // we're being called.
+  ArtField* field = reference_class->GetField(reference_class->NumFields() - 1);
   DCHECK(field->IsStatic());
+  DCHECK_STREQ(field->GetName(), "slowPathEnabled");
   return field->GetOffset();
 }