JDWP: more GC safety

Ensures GC safety when keeping references that may be moved by GC:
- SingleStepControl: stores ArtMethod* in a GcRoot
- ModBasket: stores references in a StackHandleScope

Bug: 18166750

(cherry picked from commit 261bc044a3575512869586593e99e97cd8b1c321)

Change-Id: I35971a901537956739d1f089d61cb4ea9dc6c93d

1 files changed, 3 insertions, 3 deletions

diff --git a/runtime/debugger.h b/runtime/debugger.h
index 789a0a4dca..811d345262 100644
--- a/runtime/debugger.h
+++ b/runtime/debugger.h
@@ -109,8 +109,8 @@ class SingleStepControl {
     return stack_depth_;
   }
 
-  mirror::ArtMethod* GetMethod() const {
-    return method_;
+  mirror::ArtMethod* GetMethod() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return method_.Read();
   }
 
   const std::set<uint32_t>& GetDexPcs() const {
@@ -138,7 +138,7 @@ class SingleStepControl {
   // set of DEX pcs associated to the source line number where the suspension occurred.
   // This is used to support SD_INTO and SD_OVER single-step depths so we detect when a single-step
   // causes the execution of an instruction in a different method or at a different line number.
-  mirror::ArtMethod* method_;
+  GcRoot<mirror::ArtMethod> method_;
   std::set<uint32_t> dex_pcs_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleStepControl);