8209413: AArch64: NPE in clhsdb jstack command

Reviewed-by: aph

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

 /*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2014, 2015, Red Hat Inc. All rights reserved.
+ * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2019, Red Hat Inc. 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
@@ -372,15 +372,9 @@ void MacroAssembler::set_last_Java_frame(Register last_java_sp,
                                          Register last_java_fp,
                                          address  last_java_pc,
                                          Register scratch) {
-  if (last_java_pc != NULL) {
-    adr(scratch, last_java_pc);
-  } else {
-    // FIXME: This is almost never correct.  We should delete all
-    // cases of set_last_Java_frame with last_java_pc=NULL and use the
-    // correct return address instead.
-    adr(scratch, pc());
-  }
+  assert(last_java_pc != NULL, "must provide a valid PC");
 
+  adr(scratch, last_java_pc);
   str(scratch, Address(rthread,
                        JavaThread::frame_anchor_offset()
                        + JavaFrameAnchor::last_Java_pc_offset()));
@@ -397,7 +391,7 @@ void MacroAssembler::set_last_Java_frame(Register last_java_sp,
   } else {
     InstructionMark im(this);
     L.add_patch_at(code(), locator());
-    set_last_Java_frame(last_java_sp, last_java_fp, (address)NULL, scratch);
+    set_last_Java_frame(last_java_sp, last_java_fp, pc() /* Patched later */, scratch);
   }
 }
 

src/hotspot/cpu/aarch64/sharedRuntime_aarch64.cpp

 /*
- * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2014, 2018, Red Hat Inc. All rights reserved.
+ * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2019, Red Hat Inc. 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
@@ -1666,14 +1666,11 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
   }
 
   // Change state to native (we save the return address in the thread, since it might not
-  // be pushed on the stack when we do a a stack traversal). It is enough that the pc()
-  // points into the right code segment. It does not have to be the correct return pc.
+  // be pushed on the stack when we do a stack traversal).
   // We use the same pc/oopMap repeatedly when we call out
 
-  intptr_t the_pc = (intptr_t) __ pc();
-  oop_maps->add_gc_map(the_pc - start, map);
-
-  __ set_last_Java_frame(sp, noreg, (address)the_pc, rscratch1);
+  Label native_return;
+  __ set_last_Java_frame(sp, noreg, native_return, rscratch1);
 
   Label dtrace_method_entry, dtrace_method_entry_done;
   {
@@ -1804,6 +1801,11 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
             return_type);
   }
 
+  __ bind(native_return);
+
+  intptr_t return_pc = (intptr_t) __ pc();
+  oop_maps->add_gc_map(return_pc - start, map);
+
   // Unpack native results.
   switch (ret_type) {
   case T_BOOLEAN: __ c2bool(r0);                     break;

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp

 /*
- * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2014, 2015, Red Hat Inc. All rights reserved.
+ * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2019, Red Hat Inc. 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
@@ -4802,7 +4802,7 @@ class StubGenerator: public StubCodeGenerator {
 
     // Set up last_Java_sp and last_Java_fp
     address the_pc = __ pc();
-    __ set_last_Java_frame(sp, rfp, (address)NULL, rscratch1);
+    __ set_last_Java_frame(sp, rfp, the_pc, rscratch1);
 
     // Call runtime
     if (arg1 != noreg) {

src/hotspot/cpu/aarch64/templateInterpreterGenerator_aarch64.cpp

 /*
- * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2014, 2018, Red Hat Inc. All rights reserved.
+ * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2019, Red Hat Inc. 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
@@ -1328,9 +1328,11 @@ address TemplateInterpreterGenerator::generate_native_entry(bool synchronized) {
   // pass JNIEnv
   __ add(c_rarg0, rthread, in_bytes(JavaThread::jni_environment_offset()));
 
-  // It is enough that the pc() points into the right code
-  // segment. It does not have to be the correct return pc.
-  __ set_last_Java_frame(esp, rfp, (address)NULL, rscratch1);
+  // Set the last Java PC in the frame anchor to be the return address from
+  // the call to the native method: this will allow the debugger to
+  // generate an accurate stack trace.
+  Label native_return;
+  __ set_last_Java_frame(esp, rfp, native_return, rscratch1);
 
   // change thread state
 #ifdef ASSERT
@@ -1351,6 +1353,7 @@ address TemplateInterpreterGenerator::generate_native_entry(bool synchronized) {
 
   // Call the native method.
   __ blr(r10);
+  __ bind(native_return);
   __ maybe_isb();
   __ get_method(rmethod);
   // result potentially in r0 or v0

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/aarch64/AARCH64CurrentFrameGuess.java

 /*
- * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2015, Red Hat Inc.
+ * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2019, Red Hat Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -223,7 +223,13 @@ public class AARCH64CurrentFrameGuess {
         }
       }
 
-      setValues(sp, fp, null);
+      // We found a PC in the frame anchor. Check that it's plausible, and
+      // if it is, use it.
+      if (vm.isJavaPCDbg(pc)) {
+        setValues(sp, fp, pc);
+      } else {
+        setValues(sp, fp, null);
+      }
 
       return true;
     }

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/aarch64/AARCH64Frame.java

 /*
- * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2015, Red Hat Inc.
+ * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2019, Red Hat Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -136,7 +136,15 @@ public class AARCH64Frame extends Frame {
     this.raw_sp = raw_sp;
     this.raw_unextendedSP = raw_sp;
     this.raw_fp = raw_fp;
-    this.pc = raw_sp.getAddressAt(-1 * VM.getVM().getAddressSize());
+
+    // We cannot assume SP[-1] always contains a valid return PC (e.g. if
+    // the callee is a C/C++ compiled frame). If the PC is not known to
+    // Java then this.pc is null.
+    Address savedPC = raw_sp.getAddressAt(-1 * VM.getVM().getAddressSize());
+    if (VM.getVM().isJavaPCDbg(savedPC)) {
+      this.pc = savedPC;
+    }
+
     adjustUnextendedSP();
 
     // Frame must be fully constructed before this call