8242263: Diagnose synchronization on primitive wrappers

Added diagnostic flag DiagnoseSyncOnPrimitiveWrappers

Reviewed-by: dholmes, mdoerr, dcubed, coleenp, egahlin, mgronlun

Author: pchilano

src/hotspot/cpu/aarch64/aarch64.ad

@@ -3511,6 +3511,13 @@ encode %{
     // Load markWord from object into displaced_header.
     __ ldr(disp_hdr, Address(oop, oopDesc::mark_offset_in_bytes()));
 
+    if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+      __ load_klass(tmp, oop);
+      __ ldrw(tmp, Address(tmp, Klass::access_flags_offset()));
+      __ tstw(tmp, JVM_ACC_IS_BOX_CLASS);
+      __ br(Assembler::NE, cont);
+    }
+
     if (UseBiasedLocking && !UseOptoBiasInlining) {
       __ biased_locking_enter(box, oop, disp_hdr, tmp, true, cont);
     }

src/hotspot/cpu/aarch64/c1_MacroAssembler_aarch64.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -73,11 +73,18 @@ int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr
   // save object being locked into the BasicObjectLock
   str(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
 
+  null_check_offset = offset();
+
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(hdr, obj);
+    ldrw(hdr, Address(hdr, Klass::access_flags_offset()));
+    tstw(hdr, JVM_ACC_IS_BOX_CLASS);
+    br(Assembler::NE, slow_case);
+  }
+
   if (UseBiasedLocking) {
     assert(scratch != noreg, "should have scratch register at this point");
-    null_check_offset = biased_locking_enter(disp_hdr, obj, hdr, scratch, false, done, &slow_case);
-  } else {
-    null_check_offset = offset();
+    biased_locking_enter(disp_hdr, obj, hdr, scratch, false, done, &slow_case);
   }
 
   // Load object header

src/hotspot/cpu/aarch64/interp_masm_aarch64.cpp

@@ -725,6 +725,13 @@ void InterpreterMacroAssembler::lock_object(Register lock_reg)
     // Load object pointer into obj_reg %c_rarg3
     ldr(obj_reg, Address(lock_reg, obj_offset));
 
+    if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+      load_klass(tmp, obj_reg);
+      ldrw(tmp, Address(tmp, Klass::access_flags_offset()));
+      tstw(tmp, JVM_ACC_IS_BOX_CLASS);
+      br(Assembler::NE, slow_case);
+    }
+
     if (UseBiasedLocking) {
       biased_locking_enter(lock_reg, obj_reg, swap_reg, tmp, false, done, &slow_case);
     }

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -444,14 +444,14 @@ void MacroAssembler::reserved_stack_check() {
     bind(no_reserved_zone_enabling);
 }
 
-int MacroAssembler::biased_locking_enter(Register lock_reg,
-                                         Register obj_reg,
-                                         Register swap_reg,
-                                         Register tmp_reg,
-                                         bool swap_reg_contains_mark,
-                                         Label& done,
-                                         Label* slow_case,
-                                         BiasedLockingCounters* counters) {
+void MacroAssembler::biased_locking_enter(Register lock_reg,
+                                          Register obj_reg,
+                                          Register swap_reg,
+                                          Register tmp_reg,
+                                          bool swap_reg_contains_mark,
+                                          Label& done,
+                                          Label* slow_case,
+                                          BiasedLockingCounters* counters) {
   assert(UseBiasedLocking, "why call this otherwise?");
   assert_different_registers(lock_reg, obj_reg, swap_reg);
 
@@ -471,9 +471,7 @@ int MacroAssembler::biased_locking_enter(Register lock_reg,
   // pointers to allow age to be placed into low bits
   // First check to see whether biasing is even enabled for this object
   Label cas_label;
-  int null_check_offset = -1;
   if (!swap_reg_contains_mark) {
-    null_check_offset = offset();
     ldr(swap_reg, mark_addr);
   }
   andr(tmp_reg, swap_reg, markWord::biased_lock_mask_in_place);
@@ -601,8 +599,6 @@ int MacroAssembler::biased_locking_enter(Register lock_reg,
   }
 
   bind(cas_label);
-
-  return null_check_offset;
 }
 
 void MacroAssembler::biased_locking_exit(Register obj_reg, Register temp_reg, Label& done) {

src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp

@@ -111,15 +111,11 @@ class MacroAssembler: public Assembler {
   // tmp_reg must be supplied and must not be rscratch1 or rscratch2
   // Optional slow case is for implementations (interpreter and C1) which branch to
   // slow case directly. Leaves condition codes set for C2's Fast_Lock node.
-  // Returns offset of first potentially-faulting instruction for null
-  // check info (currently consumed only by C1). If
-  // swap_reg_contains_mark is true then returns -1 as it is assumed
-  // the calling code has already passed any potential faults.
-  int biased_locking_enter(Register lock_reg, Register obj_reg,
-                           Register swap_reg, Register tmp_reg,
-                           bool swap_reg_contains_mark,
-                           Label& done, Label* slow_case = NULL,
-                           BiasedLockingCounters* counters = NULL);
+  void biased_locking_enter(Register lock_reg, Register obj_reg,
+                            Register swap_reg, Register tmp_reg,
+                            bool swap_reg_contains_mark,
+                            Label& done, Label* slow_case = NULL,
+                            BiasedLockingCounters* counters = NULL);
   void biased_locking_exit (Register obj_reg, Register temp_reg, Label& done);
 
 

src/hotspot/cpu/arm/c1_MacroAssembler_arm.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2020, 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
@@ -200,26 +200,29 @@ int C1_MacroAssembler::lock_object(Register hdr, Register obj,
   const int obj_offset = BasicObjectLock::obj_offset_in_bytes();
   const int mark_offset = BasicLock::displaced_header_offset_in_bytes();
 
-  if (UseBiasedLocking) {
-    // load object
-    str(obj, Address(disp_hdr, obj_offset));
-    null_check_offset = biased_locking_enter(obj, hdr/*scratched*/, tmp1, false, tmp2, done, slow_case);
-  }
+  str(obj, Address(disp_hdr, obj_offset));
 
-  assert(oopDesc::mark_offset_in_bytes() == 0, "Required by atomic instructions");
+  null_check_offset = offset();
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(tmp1, obj);
+    ldr_u32(tmp1, Address(tmp1, Klass::access_flags_offset()));
+    tst(tmp1, JVM_ACC_IS_BOX_CLASS);
+    b(slow_case, ne);
+  }
 
-  if (!UseBiasedLocking) {
-    null_check_offset = offset();
+  if (UseBiasedLocking) {
+    biased_locking_enter(obj, hdr/*scratched*/, tmp1, false, tmp2, done, slow_case);
   }
 
+  assert(oopDesc::mark_offset_in_bytes() == 0, "Required by atomic instructions");
+
   // On MP platforms the next load could return a 'stale' value if the memory location has been modified by another thread.
   // That would be acceptable as ether CAS or slow case path is taken in that case.
 
   // Must be the first instruction here, because implicit null check relies on it
   ldr(hdr, Address(obj, oopDesc::mark_offset_in_bytes()));
 
-  str(obj, Address(disp_hdr, obj_offset));
   tst(hdr, markWord::unlocked_value);
   b(fast_lock, ne);
 

src/hotspot/cpu/arm/c2_MacroAssembler_arm.cpp

@@ -90,6 +90,13 @@ void C2_MacroAssembler::fast_lock(Register Roop, Register Rbox, Register Rscratc
 
   Label fast_lock, done;
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(Rscratch, Roop);
+    ldr_u32(Rscratch, Address(Rscratch, Klass::access_flags_offset()));
+    tst(Rscratch, JVM_ACC_IS_BOX_CLASS);
+    b(done, ne);
+  }
+
   if (UseBiasedLocking && !UseOptoBiasInlining) {
     assert(scratch3 != noreg, "need extra temporary for -XX:-UseOptoBiasInlining");
     biased_locking_enter(Roop, Rmark, Rscratch, false, scratch3, done, done);

src/hotspot/cpu/arm/interp_masm_arm.cpp

@@ -883,6 +883,13 @@ void InterpreterMacroAssembler::lock_object(Register Rlock) {
     // Load object pointer
     ldr(Robj, Address(Rlock, obj_offset));
 
+    if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+      load_klass(R0, Robj);
+      ldr_u32(R0, Address(R0, Klass::access_flags_offset()));
+      tst(R0, JVM_ACC_IS_BOX_CLASS);
+      b(slow_case, ne);
+    }
+
     if (UseBiasedLocking) {
       biased_locking_enter(Robj, Rmark/*scratched*/, R0, false, Rtemp, done, slow_case);
     }

src/hotspot/cpu/arm/macroAssembler_arm.cpp

@@ -1322,11 +1322,11 @@ void MacroAssembler::biased_locking_enter_with_cas(Register obj_reg, Register ol
 #endif // !PRODUCT
 }
 
-int MacroAssembler::biased_locking_enter(Register obj_reg, Register swap_reg, Register tmp_reg,
-                                         bool swap_reg_contains_mark,
-                                         Register tmp2,
-                                         Label& done, Label& slow_case,
-                                         BiasedLockingCounters* counters) {
+void MacroAssembler::biased_locking_enter(Register obj_reg, Register swap_reg, Register tmp_reg,
+                                          bool swap_reg_contains_mark,
+                                          Register tmp2,
+                                          Label& done, Label& slow_case,
+                                          BiasedLockingCounters* counters) {
   // obj_reg must be preserved (at least) if the bias locking fails
   // tmp_reg is a temporary register
   // swap_reg was used as a temporary but contained a value
@@ -1357,10 +1357,6 @@ int MacroAssembler::biased_locking_enter(Register obj_reg, Register swap_reg, Re
   // First check to see whether biasing is even enabled for this object
   Label cas_label;
 
-  // The null check applies to the mark loading, if we need to load it.
-  // If the mark has already been loaded in swap_reg then it has already
-  // been performed and the offset is irrelevant.
-  int null_check_offset = offset();
   if (!swap_reg_contains_mark) {
     ldr(swap_reg, mark_addr);
   }
@@ -1504,8 +1500,6 @@ int MacroAssembler::biased_locking_enter(Register obj_reg, Register swap_reg, Re
   // removing the bias bit from the object's header.
 
   bind(cas_label);
-
-  return null_check_offset;
 }
 
 

src/hotspot/cpu/arm/macroAssembler_arm.hpp

@@ -375,18 +375,14 @@ class MacroAssembler: public Assembler {
   // biased and we acquired it. Slow case label is branched to with
   // condition code NE set if the lock is biased but we failed to acquire
   // it. Otherwise fall through.
-  // Returns offset of first potentially-faulting instruction for null
-  // check info (currently consumed only by C1). If
-  // swap_reg_contains_mark is true then returns -1 as it is assumed
-  // the calling code has already passed any potential faults.
   // Notes:
   // - swap_reg and tmp_reg are scratched
   // - Rtemp was (implicitly) scratched and can now be specified as the tmp2
-  int biased_locking_enter(Register obj_reg, Register swap_reg, Register tmp_reg,
-                           bool swap_reg_contains_mark,
-                           Register tmp2,
-                           Label& done, Label& slow_case,
-                           BiasedLockingCounters* counters = NULL);
+  void biased_locking_enter(Register obj_reg, Register swap_reg, Register tmp_reg,
+                            bool swap_reg_contains_mark,
+                            Register tmp2,
+                            Label& done, Label& slow_case,
+                            BiasedLockingCounters* counters = NULL);
   void biased_locking_exit(Register obj_reg, Register temp_reg, Label& done);
 
   // Building block for CAS cases of biased locking: makes CAS and records statistics.

src/hotspot/cpu/ppc/c1_MacroAssembler_ppc.cpp

@@ -105,6 +105,13 @@ void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox
   // Save object being locked into the BasicObjectLock...
   std(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(Rscratch, Roop);
+    lwz(Rscratch, in_bytes(Klass::access_flags_offset()), Rscratch);
+    testbitdi(CCR0, R0, Rscratch, exact_log2(JVM_ACC_IS_BOX_CLASS));
+    bne(CCR0, slow_int);
+  }
+
   if (UseBiasedLocking) {
     biased_locking_enter(CCR0, Roop, Rmark, Rscratch, R0, done, &slow_int);
   }

src/hotspot/cpu/ppc/interp_masm_ppc_64.cpp

@@ -910,6 +910,13 @@ void InterpreterMacroAssembler::lock_object(Register monitor, Register object) {
     // Load markWord from object into displaced_header.
     ld(displaced_header, oopDesc::mark_offset_in_bytes(), object);
 
+    if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+      load_klass(tmp, object);
+      lwz(tmp, in_bytes(Klass::access_flags_offset()), tmp);
+      testbitdi(CCR0, R0, tmp, exact_log2(JVM_ACC_IS_BOX_CLASS));
+      bne(CCR0, slow_case);
+    }
+
     if (UseBiasedLocking) {
       biased_locking_enter(CCR0, object, displaced_header, tmp, current_header, done, &slow_case);
     }

src/hotspot/cpu/ppc/macroAssembler_ppc.cpp

@@ -2836,6 +2836,12 @@ void MacroAssembler::compiler_fast_lock_object(ConditionRegister flag, Register
   // Load markWord from object into displaced_header.
   ld(displaced_header, oopDesc::mark_offset_in_bytes(), oop);
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(temp, oop);
+    lwz(temp, in_bytes(Klass::access_flags_offset()), temp);
+    testbitdi(flag, R0, temp, exact_log2(JVM_ACC_IS_BOX_CLASS));
+    bne(flag, cont);
+  }
 
   if (try_bias) {
     biased_locking_enter(flag, oop, displaced_header, temp, current_header, cont);

src/hotspot/cpu/s390/c1_MacroAssembler_s390.cpp

@@ -91,6 +91,12 @@ void C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hd
   // Save object being locked into the BasicObjectLock...
   z_stg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(Z_R1_scratch, obj);
+    testbit(Address(Z_R1_scratch, Klass::access_flags_offset()), exact_log2(JVM_ACC_IS_BOX_CLASS));
+    z_btrue(slow_case);
+  }
+
   if (UseBiasedLocking) {
     biased_locking_enter(obj, hdr, Z_R1_scratch, Z_R0_scratch, done, &slow_case);
   }

src/hotspot/cpu/s390/interp_masm_s390.cpp

@@ -1000,6 +1000,12 @@ void InterpreterMacroAssembler::lock_object(Register monitor, Register object) {
   // Load markWord from object into displaced_header.
   z_lg(displaced_header, oopDesc::mark_offset_in_bytes(), object);
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(Z_R1_scratch, object);
+    testbit(Address(Z_R1_scratch, Klass::access_flags_offset()), exact_log2(JVM_ACC_IS_BOX_CLASS));
+    z_btrue(slow_case);
+  }
+
   if (UseBiasedLocking) {
     biased_locking_enter(object, displaced_header, Z_R1, Z_R0, done, &slow_case);
   }

src/hotspot/cpu/s390/macroAssembler_s390.cpp

@@ -3358,6 +3358,14 @@ void MacroAssembler::compiler_fast_lock_object(Register oop, Register box, Regis
   // Load markWord from oop into mark.
   z_lg(displacedHeader, 0, oop);
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(Z_R1_scratch, oop);
+    z_l(Z_R1_scratch, Address(Z_R1_scratch, Klass::access_flags_offset()));
+    assert((JVM_ACC_IS_BOX_CLASS & 0xFFFF) == 0, "or change following instruction");
+    z_nilh(Z_R1_scratch, JVM_ACC_IS_BOX_CLASS >> 16);
+    z_brne(done);
+  }
+
   if (try_bias) {
     biased_locking_enter(oop, displacedHeader, temp, Z_R0, done);
   }

src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2020, 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
@@ -39,6 +39,7 @@
 #include "runtime/stubRoutines.hpp"
 
 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register scratch, Label& slow_case) {
+  const Register rklass_decode_tmp = LP64_ONLY(rscratch1) NOT_LP64(noreg);
   const int aligned_mask = BytesPerWord -1;
   const int hdr_offset = oopDesc::mark_offset_in_bytes();
   assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
@@ -51,12 +52,18 @@ int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr
   // save object being locked into the BasicObjectLock
   movptr(Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()), obj);
 
+  null_check_offset = offset();
+
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(hdr, obj, rklass_decode_tmp);
+    movl(hdr, Address(hdr, Klass::access_flags_offset()));
+    testl(hdr, JVM_ACC_IS_BOX_CLASS);
+    jcc(Assembler::notZero, slow_case);
+  }
+
   if (UseBiasedLocking) {
     assert(scratch != noreg, "should have scratch register at this point");
-    Register rklass_decode_tmp = LP64_ONLY(rscratch1) NOT_LP64(noreg);
-    null_check_offset = biased_locking_enter(disp_hdr, obj, hdr, scratch, rklass_decode_tmp, false, done, &slow_case);
-  } else {
-    null_check_offset = offset();
+    biased_locking_enter(disp_hdr, obj, hdr, scratch, rklass_decode_tmp, false, done, &slow_case);
   }
 
   // Load object header

src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp

@@ -470,6 +470,13 @@ void C2_MacroAssembler::fast_lock(Register objReg, Register boxReg, Register tmp
 
   Label IsInflated, DONE_LABEL;
 
+  if (DiagnoseSyncOnPrimitiveWrappers != 0) {
+    load_klass(tmpReg, objReg, cx1Reg);
+    movl(tmpReg, Address(tmpReg, Klass::access_flags_offset()));
+    testl(tmpReg, JVM_ACC_IS_BOX_CLASS);
+    jcc(Assembler::notZero, DONE_LABEL);
+  }
+
   // it's stack-locked, biased or neutral
   // TODO: optimize away redundant LDs of obj->mark and improve the markword triage
   // order to reduce the number of conditional branches in the most common cases.