--- a/hotspot/src/cpu/sparc/vm/frame_sparc.inline.hpp	Fri Jan 13 12:58:26 2012 -0800
+++ b/hotspot/src/cpu/sparc/vm/frame_sparc.inline.hpp	Wed Jan 18 16:18:31 2012 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -82,6 +82,8 @@
 
 inline intptr_t*    frame::sender_sp() const  { return fp(); }
 
+inline intptr_t* frame::real_fp() const { return fp(); }
+
 // Used only in frame::oopmapreg_to_location
 // This return a value in VMRegImpl::slot_size
 inline int frame::pd_oop_map_offset_adjustment() const {

--- a/hotspot/src/cpu/x86/vm/frame_x86.cpp	Fri Jan 13 12:58:26 2012 -0800
+++ b/hotspot/src/cpu/x86/vm/frame_x86.cpp	Wed Jan 18 16:18:31 2012 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -675,3 +675,21 @@
   // used to reset the saved FP
   return fp();
 }
+
+intptr_t* frame::real_fp() const {
+  if (_cb != NULL) {
+    // use the frame size if valid
+    int size = _cb->frame_size();
+    if ((size > 0) &&
+        (! is_ricochet_frame())) {
+      // Work-around: ricochet explicitly excluded because frame size is not
+      // constant for the ricochet blob but its frame_size could not, for
+      // some reasons, be declared as <= 0. This potentially confusing
+      // size declaration should be fixed as another CR.
+      return unextended_sp() + size;
+    }
+  }
+  // else rely on fp()
+  assert(! is_compiled_frame(), "unknown compiled frame size");
+  return fp();
+}

--- a/hotspot/src/cpu/x86/vm/frame_x86.hpp	Fri Jan 13 12:58:26 2012 -0800
+++ b/hotspot/src/cpu/x86/vm/frame_x86.hpp	Wed Jan 18 16:18:31 2012 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -188,6 +188,7 @@
   frame(intptr_t* sp, intptr_t* fp);
 
   // accessors for the instance variables
+  // Note: not necessarily the real 'frame pointer' (see real_fp)
   intptr_t*   fp() const { return _fp; }
 
   inline address* sender_pc_addr() const;

--- a/hotspot/src/cpu/zero/vm/frame_zero.inline.hpp	Fri Jan 13 12:58:26 2012 -0800
+++ b/hotspot/src/cpu/zero/vm/frame_zero.inline.hpp	Wed Jan 18 16:18:31 2012 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2007, 2008, 2009, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -72,6 +72,10 @@
   return fp() + 1;
 }
 
+inline intptr_t* frame::real_fp() const {
+  return fp();
+}
+
 inline intptr_t* frame::link() const {
   ShouldNotCallThis();
 }

--- a/hotspot/src/share/vm/runtime/frame.cpp	Fri Jan 13 12:58:26 2012 -0800
+++ b/hotspot/src/share/vm/runtime/frame.cpp	Wed Jan 18 16:18:31 2012 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1334,24 +1334,21 @@
 
 
 void frame::describe(FrameValues& values, int frame_no) {
+  intptr_t* frame_pointer = real_fp();
   if (is_entry_frame() || is_compiled_frame() || is_interpreted_frame() || is_native_frame()) {
     // Label values common to most frames
     values.describe(-1, unextended_sp(), err_msg("unextended_sp for #%d", frame_no));
     values.describe(-1, sp(), err_msg("sp for #%d", frame_no));
-    if (is_compiled_frame()) {
-      values.describe(-1, sp() + _cb->frame_size(), err_msg("computed fp for #%d", frame_no));
-    } else {
-      values.describe(-1, fp(), err_msg("fp for #%d", frame_no));
-    }
+    values.describe(-1, frame_pointer, err_msg("frame pointer for #%d", frame_no));
   }
   if (is_interpreted_frame()) {
     methodOop m = interpreter_frame_method();
     int bci = interpreter_frame_bci();
 
     // Label the method and current bci
-    values.describe(-1, MAX2(sp(), fp()),
+    values.describe(-1, MAX2(sp(), frame_pointer),
                     FormatBuffer<1024>("#%d method %s @ %d", frame_no, m->name_and_sig_as_C_string(), bci), 2);
-    values.describe(-1, MAX2(sp(), fp()),
+    values.describe(-1, MAX2(sp(), frame_pointer),
                     err_msg("- %d locals %d max stack", m->max_locals(), m->max_stack()), 1);
     if (m->max_locals() > 0) {
       intptr_t* l0 = interpreter_frame_local_at(0);
@@ -1383,18 +1380,18 @@
     }
   } else if (is_entry_frame()) {
     // For now just label the frame
-    values.describe(-1, MAX2(sp(), fp()), err_msg("#%d entry frame", frame_no), 2);
+    values.describe(-1, MAX2(sp(), frame_pointer), err_msg("#%d entry frame", frame_no), 2);
   } else if (is_compiled_frame()) {
     // For now just label the frame
     nmethod* nm = cb()->as_nmethod_or_null();
-    values.describe(-1, MAX2(sp(), fp()),
+    values.describe(-1, MAX2(sp(), frame_pointer),
                     FormatBuffer<1024>("#%d nmethod " INTPTR_FORMAT " for method %s%s", frame_no,
                                        nm, nm->method()->name_and_sig_as_C_string(),
                                        is_deoptimized_frame() ? " (deoptimized" : ""), 2);
   } else if (is_native_frame()) {
     // For now just label the frame
     nmethod* nm = cb()->as_nmethod_or_null();
-    values.describe(-1, MAX2(sp(), fp()),
+    values.describe(-1, MAX2(sp(), frame_pointer),
                     FormatBuffer<1024>("#%d nmethod " INTPTR_FORMAT " for native method %s", frame_no,
                                        nm, nm->method()->name_and_sig_as_C_string()), 2);
   }

--- a/hotspot/src/share/vm/runtime/frame.hpp	Fri Jan 13 12:58:26 2012 -0800
+++ b/hotspot/src/share/vm/runtime/frame.hpp	Wed Jan 18 16:18:31 2012 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -221,6 +221,15 @@
   // returns the stack pointer of the calling frame
   intptr_t* sender_sp() const;
 
+  // Returns the real 'frame pointer' for the current frame.
+  // This is the value expected by the platform ABI when it defines a
+  // frame pointer register. It may differ from the effective value of
+  // the FP register when that register is used in the JVM for other
+  // purposes (like compiled frames on some platforms).
+  // On other platforms, it is defined so that the stack area used by
+  // this frame goes from real_fp() to sp().
+  intptr_t* real_fp() const;
+
   // Deoptimization info, if needed (platform dependent).
   // Stored in the initial_info field of the unroll info, to be used by
   // the platform dependent deoptimization blobs.