8299089: Instrument global jni handles with tag to make them distingu…

…ishable

Co-authored-by: Stefan Karlsson <stefank@openjdk.org>
Co-authored-by: Martin Doerr <mdoerr@openjdk.org>
Co-authored-by: Leslie Zhai <lzhai@openjdk.org>
Reviewed-by: eosterlund, stefank, ayang

src/hotspot/cpu/aarch64/gc/shared/barrierSetAssembler_aarch64.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, 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
@@ -122,8 +122,8 @@ void BarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators
 void BarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,
                                                         Register obj, Register tmp, Label& slowpath) {
   // If mask changes we need to ensure that the inverse is still encodable as an immediate
-  STATIC_ASSERT(JNIHandles::weak_tag_mask == 1);
-  __ andr(obj, obj, ~JNIHandles::weak_tag_mask);
+  STATIC_ASSERT(JNIHandles::tag_mask == 0b11);
+  __ andr(obj, obj, ~JNIHandles::tag_mask);
   __ ldr(obj, Address(obj, 0));             // *obj
 }
 

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, 2021, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -2458,22 +2458,56 @@ void MacroAssembler::verify_heapbase(const char* msg) {
 #endif
 
 void MacroAssembler::resolve_jobject(Register value, Register tmp1, Register tmp2) {
-  Label done, not_weak;
+  assert_different_registers(value, tmp1, tmp2);
+  Label done, tagged, weak_tagged;
+
   cbz(value, done);           // Use NULL as-is.
+  tst(value, JNIHandles::tag_mask); // Test for tag.
+  br(Assembler::NE, tagged);
+
+  // Resolve local handle
+  access_load_at(T_OBJECT, IN_NATIVE | AS_RAW, value, Address(value, 0), tmp1, tmp2);
+  verify_oop(value);
+  b(done);
 
-  STATIC_ASSERT(JNIHandles::weak_tag_mask == 1u);
-  tbz(value, 0, not_weak);    // Test for jweak tag.
+  bind(tagged);
+  STATIC_ASSERT(JNIHandles::TypeTag::weak_global == 0b1);
+  tbnz(value, 0, weak_tagged);    // Test for weak tag.
 
-  // Resolve jweak.
-  access_load_at(T_OBJECT, IN_NATIVE | ON_PHANTOM_OOP_REF, value,
-                 Address(value, -JNIHandles::weak_tag_value), tmp1, tmp2);
+  // Resolve global handle
+  access_load_at(T_OBJECT, IN_NATIVE, value, Address(value, -JNIHandles::TypeTag::global), tmp1, tmp2);
   verify_oop(value);
   b(done);
 
-  bind(not_weak);
-  // Resolve (untagged) jobject.
-  access_load_at(T_OBJECT, IN_NATIVE, value, Address(value, 0), tmp1, tmp2);
+  bind(weak_tagged);
+  // Resolve jweak.
+  access_load_at(T_OBJECT, IN_NATIVE | ON_PHANTOM_OOP_REF,
+                 value, Address(value, -JNIHandles::TypeTag::weak_global), tmp1, tmp2);
+  verify_oop(value);
+
+  bind(done);
+}
+
+void MacroAssembler::resolve_global_jobject(Register value, Register tmp1, Register tmp2) {
+  assert_different_registers(value, tmp1, tmp2);
+  Label done;
+
+  cbz(value, done);           // Use NULL as-is.
+
+#ifdef ASSERT
+  {
+    STATIC_ASSERT(JNIHandles::TypeTag::global == 0b10);
+    Label valid_global_tag;
+    tbnz(value, 1, valid_global_tag); // Test for global tag
+    stop("non global jobject using resolve_global_jobject");
+    bind(valid_global_tag);
+  }
+#endif
+
+  // Resolve global handle
+  access_load_at(T_OBJECT, IN_NATIVE, value, Address(value, -JNIHandles::TypeTag::global), tmp1, tmp2);
   verify_oop(value);
+
   bind(done);
 }
 

src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp

@@ -823,6 +823,7 @@ class MacroAssembler: public Assembler {
   void store_check(Register obj, Address dst);   // same as above, dst is exact store location (reg. is destroyed)
 
   void resolve_jobject(Register value, Register tmp1, Register tmp2);
+  void resolve_global_jobject(Register value, Register tmp1, Register tmp2);
 
   // C 'boolean' to Java boolean: x == 0 ? 0 : 1
   void c2bool(Register x);

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp

@@ -6923,12 +6923,7 @@ class StubGenerator: public StubCodeGenerator {
   // The handle is dereferenced through a load barrier.
   static void jfr_epilogue(MacroAssembler* _masm) {
     __ reset_last_Java_frame(true);
-    Label null_jobject;
-    __ cbz(r0, null_jobject);
-    DecoratorSet decorators = ACCESS_READ | IN_NATIVE;
-    BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
-    bs->load_at(_masm, decorators, T_OBJECT, r0, Address(r0, 0), rscratch1, rscratch2);
-    __ bind(null_jobject);
+    __ resolve_global_jobject(r0, rscratch1, rscratch2);
   }
 
   // For c2: c_rarg0 is junk, call to runtime to write a checkpoint.
@@ -6943,7 +6938,7 @@ class StubGenerator: public StubCodeGenerator {
       framesize // inclusive of return address
     };
 
-    int insts_size = 512;
+    int insts_size = 1024;
     int locs_size = 64;
     CodeBuffer code("jfr_write_checkpoint", insts_size, locs_size);
     OopMapSet* oop_maps = new OopMapSet();

src/hotspot/cpu/arm/jniFastGetField_arm.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2023, 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
@@ -113,7 +113,7 @@ address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
   __ ldr_s32(Rsafept_cnt, Address(Rsafepoint_counter_addr));
   __ tbnz(Rsafept_cnt, 0, slow_case);
 
-  __ bic(R1, R1, JNIHandles::weak_tag_mask);
+  __ bic(R1, R1, JNIHandles::tag_mask);
 
   if (JvmtiExport::can_post_field_access()) {
     // Using barrier to order wrt. JVMTI check and load of result.

src/hotspot/cpu/arm/macroAssembler_arm.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2023, 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
@@ -1284,20 +1284,57 @@ void MacroAssembler::resolve_jobject(Register value,
                                      Register tmp1,
                                      Register tmp2) {
   assert_different_registers(value, tmp1, tmp2);
-  Label done, not_weak;
-  cbz(value, done);             // Use NULL as-is.
-  STATIC_ASSERT(JNIHandles::weak_tag_mask == 1u);
-  tbz(value, 0, not_weak);      // Test for jweak tag.
+  Label done, tagged, weak_tagged;
 
+  cbz(value, done);           // Use NULL as-is.
+  tst(value, JNIHandles::tag_mask); // Test for tag.
+  b(tagged, ne);
+
+  // Resolve local handle
+  access_load_at(T_OBJECT, IN_NATIVE | AS_RAW, Address(value, 0), value, tmp1, tmp2, noreg);
+  verify_oop(value);
+  b(done);
+
+  bind(tagged);
+  tst(value, JNIHandles::TypeTag::weak_global); // Test for weak tag.
+  b(weak_tagged, ne);
+
+  // Resolve global handle
+  access_load_at(T_OBJECT, IN_NATIVE, Address(value, -JNIHandles::TypeTag::global), value, tmp1, tmp2, noreg);
+  verify_oop(value);
+  b(done);
+
+  bind(weak_tagged);
   // Resolve jweak.
   access_load_at(T_OBJECT, IN_NATIVE | ON_PHANTOM_OOP_REF,
-                 Address(value, -JNIHandles::weak_tag_value), value, tmp1, tmp2, noreg);
-  b(done);
-  bind(not_weak);
-  // Resolve (untagged) jobject.
-  access_load_at(T_OBJECT, IN_NATIVE,
-                 Address(value, 0), value, tmp1, tmp2, noreg);
+                 Address(value, -JNIHandles::TypeTag::weak_global), value, tmp1, tmp2, noreg);
   verify_oop(value);
+
+  bind(done);
+}
+
+void MacroAssembler::resolve_global_jobject(Register value,
+                                     Register tmp1,
+                                     Register tmp2) {
+  assert_different_registers(value, tmp1, tmp2);
+  Label done;
+
+  cbz(value, done);           // Use NULL as-is.
+
+#ifdef ASSERT
+  {
+    Label valid_global_tag;
+    tst(value, JNIHandles::TypeTag::global); // Test for global tag.
+    b(valid_global_tag, ne);
+    stop("non global jobject using resolve_global_jobject");
+    bind(valid_global_tag);
+  }
+#endif
+
+  // Resolve global handle
+  access_load_at(T_OBJECT, IN_NATIVE, Address(value, -JNIHandles::TypeTag::global), value, tmp1, tmp2, noreg);
+  verify_oop(value);
+
   bind(done);
 }
 

src/hotspot/cpu/arm/macroAssembler_arm.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2023, 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
@@ -356,6 +356,7 @@ class MacroAssembler: public Assembler {
   }
 
   void resolve_jobject(Register value, Register tmp1, Register tmp2);
+  void resolve_global_jobject(Register value, Register tmp1, Register tmp2);
 
   void nop() {
     mov(R0, R0);

src/hotspot/cpu/arm/stubGenerator_arm.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2023, 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
@@ -3053,13 +3053,7 @@ class StubGenerator: public StubCodeGenerator {
     __ reset_last_Java_frame(Rtemp);
 
     // R0 is jobject handle result, unpack and process it through a barrier.
-    Label L_null_jobject;
-    __ cbz(R0, L_null_jobject);
-
-    BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
-    bs->load_at(masm, ACCESS_READ | IN_NATIVE, T_OBJECT, R0, Address(R0, 0), Rtemp, R1, R2);
-
-    __ bind(L_null_jobject);
+    __ resolve_global_jobject(R0, Rtemp, R1);
 
     __ raw_pop(R1, R2, LR);
     __ ret();

src/hotspot/cpu/ppc/gc/g1/g1BarrierSetAssembler_ppc.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2018, 2021 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -377,8 +377,8 @@ void G1BarrierSetAssembler::resolve_jobject(MacroAssembler* masm, Register value
   __ cmpdi(CCR0, value, 0);
   __ beq(CCR0, done);         // Use NULL as-is.
 
-  __ clrrdi(tmp1, value, JNIHandles::weak_tag_size);
-  __ andi_(tmp2, value, JNIHandles::weak_tag_mask);
+  __ clrrdi(tmp1, value, JNIHandles::tag_size);
+  __ andi_(tmp2, value, JNIHandles::TypeTag::weak_global);
   __ ld(value, 0, tmp1);      // Resolve (untagged) jobject.
 
   __ beq(CCR0, not_weak);     // Test for jweak tag.

src/hotspot/cpu/ppc/gc/shared/barrierSetAssembler_ppc.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2018, 2022 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -115,31 +115,65 @@ void BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators,
 void BarrierSetAssembler::resolve_jobject(MacroAssembler* masm, Register value,
                                           Register tmp1, Register tmp2,
                                           MacroAssembler::PreservationLevel preservation_level) {
-  Label done, not_weak, verify;
+  Label done, tagged, weak_tagged, verify;
   __ cmpdi(CCR0, value, 0);
   __ beq(CCR0, done);         // Use NULL as-is.
 
-  __ andi_(tmp1, value, JNIHandles::weak_tag_mask);
-  __ beq(CCR0, not_weak);     // Test for jweak tag.
+  __ andi_(tmp1, value, JNIHandles::tag_mask);
+  __ bne(CCR0, tagged);       // Test for tag.
 
-  // Resolve (untagged) jobject.
-  __ clrrdi(value, value, JNIHandles::weak_tag_size);
-  load_at(masm, IN_NATIVE | ON_PHANTOM_OOP_REF, T_OBJECT,
-          value, (intptr_t)0, value, tmp1, tmp2, preservation_level);
+  __ access_load_at(T_OBJECT, IN_NATIVE | AS_RAW, // no uncoloring
+                    value, (intptr_t)0, value, tmp1, tmp2, preservation_level);
   __ b(verify);
 
-  __ bind(not_weak);
-  load_at(masm, IN_NATIVE, T_OBJECT,
-          value, (intptr_t)0, value, tmp1, tmp2, preservation_level);
+  __ bind(tagged);
+  __ andi_(tmp1, value, JNIHandles::TypeTag::weak_global);
+  __ clrrdi(value, value, JNIHandles::tag_size); // Untag.
+  __ bne(CCR0, weak_tagged);   // Test for jweak tag.
+
+  __ access_load_at(T_OBJECT, IN_NATIVE,
+                    value, (intptr_t)0, value, tmp1, tmp2, preservation_level);
+  __ b(verify);
+
+  __ bind(weak_tagged);
+  __ access_load_at(T_OBJECT, IN_NATIVE | ON_PHANTOM_OOP_REF,
+                    value, (intptr_t)0, value, tmp1, tmp2, preservation_level);
 
   __ bind(verify);
   __ verify_oop(value, FILE_AND_LINE);
   __ bind(done);
 }
 
+// Generic implementation. GCs can provide an optimized one.
+void BarrierSetAssembler::resolve_global_jobject(MacroAssembler* masm, Register value,
+                                          Register tmp1, Register tmp2,
+                                          MacroAssembler::PreservationLevel preservation_level) {
+  Label done;
+
+  __ cmpdi(CCR0, value, 0);
+  __ beq(CCR0, done);         // Use NULL as-is.
+
+#ifdef ASSERT
+  {
+    Label valid_global_tag;
+    __ andi_(tmp1, value, JNIHandles::TypeTag::global);
+    __ bne(CCR0, valid_global_tag);       // Test for global tag.
+    __ stop("non global jobject using resolve_global_jobject");
+    __ bind(valid_global_tag);
+  }
+#endif
+
+  __ clrrdi(value, value, JNIHandles::tag_size); // Untag.
+  __ access_load_at(T_OBJECT, IN_NATIVE,
+                    value, (intptr_t)0, value, tmp1, tmp2, preservation_level);
+  __ verify_oop(value, FILE_AND_LINE);
+
+  __ bind(done);
+}
+
 void BarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register dst, Register jni_env,
                                                         Register obj, Register tmp, Label& slowpath) {
-  __ clrrdi(dst, obj, JNIHandles::weak_tag_size);
+  __ clrrdi(dst, obj, JNIHandles::tag_size);
   __ ld(dst, 0, dst);         // Resolve (untagged) jobject.
 }
 

src/hotspot/cpu/ppc/gc/shared/barrierSetAssembler_ppc.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2018, 2022 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -56,6 +56,9 @@ class BarrierSetAssembler: public CHeapObj<mtGC> {
   virtual void resolve_jobject(MacroAssembler* masm, Register value,
                                Register tmp1, Register tmp2,
                                MacroAssembler::PreservationLevel preservation_level);
+  virtual void resolve_global_jobject(MacroAssembler* masm, Register value,
+                                      Register tmp1, Register tmp2,
+                                      MacroAssembler::PreservationLevel preservation_level);
 
   virtual void try_resolve_jobject_in_native(MacroAssembler* masm, Register dst, Register jni_env,
                                              Register obj, Register tmp, Label& slowpath);

src/hotspot/cpu/ppc/gc/shared/modRefBarrierSetAssembler_ppc.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2018, 2021 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -84,7 +84,7 @@ void ModRefBarrierSetAssembler::resolve_jobject(MacroAssembler* masm, Register v
   __ cmpdi(CCR0, value, 0);
   __ beq(CCR0, done);         // Use NULL as-is.
 
-  __ clrrdi(tmp1, value, JNIHandles::weak_tag_size);
+  __ clrrdi(tmp1, value, JNIHandles::tag_size);
   __ ld(value, 0, tmp1);      // Resolve (untagged) jobject.
 
   __ verify_oop(value, FILE_AND_LINE);