JDWP: fix breakpoint for method in the image

When we set a breakpoint in a compiled method, we deoptimize it by
changing its entrypoint so it is executed with the interpreter.
However, methods in the image can be called with their direct code
pointer, ignoring the updated entrypoint. In that case, the method
is not executed with the interpreter and we miss the breakpoint.

This CL avoids that situation by forcing a full deoptimization so
everything runs with the interpreter. However, if the image has been
compiled in PIC mode, we keep using selective deoptimization because
direct code pointer is not used in this mode.

Bug: 17965285
Change-Id: Icaf8cbb7fe9ad01d36f7378c59d50d9ce42ae57f

1 files changed, 10 insertions, 2 deletions

diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index 49b132d..86d027b 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -3266,8 +3266,16 @@ static DeoptimizationRequest::Kind GetRequiredDeoptimizationKind(Thread* self,
       ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
       const bool is_compiled = class_linker->GetOatMethodQuickCodeFor(m) != nullptr;
       if (is_compiled) {
-        VLOG(jdwp) << "Need selective deoptimization for compiled method " << PrettyMethod(m);
-        return DeoptimizationRequest::kSelectiveDeoptimization;
+        // If the method may be called through its direct code pointer (without loading
+        // its updated entrypoint), we need full deoptimization to not miss the breakpoint.
+        if (class_linker->MayBeCalledWithDirectCodePointer(m)) {
+          VLOG(jdwp) << "Need full deoptimization because of possible direct code call "
+                     << "into image for compiled method " << PrettyMethod(m);
+          return DeoptimizationRequest::kFullDeoptimization;
+        } else {
+          VLOG(jdwp) << "Need selective deoptimization for compiled method " << PrettyMethod(m);
+          return DeoptimizationRequest::kSelectiveDeoptimization;
+        }
       } else {
         // Method is not compiled: we don't need to deoptimize.
         VLOG(jdwp) << "No need for deoptimization for non-compiled method " << PrettyMethod(m);