8153892: Handle unsafe access error directly in signal handler instead of going through a stub
authormikael
Tue, 03 May 2016 08:12:25 -0700
changeset 38174 f611c50b8703
parent 38173 73d05e56ec86
child 38175 4e2bff1a5467
8153892: Handle unsafe access error directly in signal handler instead of going through a stub Reviewed-by: stuefe, dholmes
hotspot/src/cpu/ppc/vm/stubGenerator_ppc.cpp
hotspot/src/cpu/sparc/vm/stubGenerator_sparc.cpp
hotspot/src/cpu/x86/vm/stubGenerator_x86_32.cpp
hotspot/src/cpu/x86/vm/stubGenerator_x86_64.cpp
hotspot/src/cpu/zero/vm/stubGenerator_zero.cpp
hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp
hotspot/src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp
hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp
hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
hotspot/src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp
hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp
hotspot/src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp
hotspot/src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp
hotspot/src/share/vm/runtime/sharedRuntime.cpp
hotspot/src/share/vm/runtime/sharedRuntime.hpp
hotspot/src/share/vm/runtime/stubRoutines.cpp
hotspot/src/share/vm/runtime/stubRoutines.hpp
--- a/hotspot/src/cpu/ppc/vm/stubGenerator_ppc.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/cpu/ppc/vm/stubGenerator_ppc.cpp	Tue May 03 08:12:25 2016 -0700
@@ -825,17 +825,6 @@
     return start;
   }
 
-  // The following routine generates a subroutine to throw an asynchronous
-  // UnknownError when an unsafe access gets a fault that could not be
-  // reasonably prevented by the programmer.  (Example: SIGBUS/OBJERR.)
-  //
-  address generate_handler_for_unsafe_access() {
-    StubCodeMark mark(this, "StubRoutines", "handler_for_unsafe_access");
-    address start = __ function_entry();
-    __ unimplemented("StubRoutines::handler_for_unsafe_access", 93);
-    return start;
-  }
-
 #if !defined(PRODUCT)
   // Wrapper which calls oopDesc::is_oop_or_null()
   // Only called by MacroAssembler::verify_oop
@@ -3111,8 +3100,6 @@
     StubRoutines::_throw_IncompatibleClassChangeError_entry= generate_throw_exception("IncompatibleClassChangeError throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_IncompatibleClassChangeError),  false);
     StubRoutines::_throw_NullPointerException_at_call_entry= generate_throw_exception("NullPointerException at call throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_NullPointerException_at_call), false);
 
-    StubRoutines::_handler_for_unsafe_access_entry         = generate_handler_for_unsafe_access();
-
     // support for verify_oop (must happen after universe_init)
     StubRoutines::_verify_oop_subroutine_entry             = generate_verify_oop();
 
--- a/hotspot/src/cpu/sparc/vm/stubGenerator_sparc.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/cpu/sparc/vm/stubGenerator_sparc.cpp	Tue May 03 08:12:25 2016 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, 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
@@ -64,20 +64,6 @@
 // -------------------------------------------------------------------------------------------------------------------------
 // Stub Code definitions
 
-static address handle_unsafe_access() {
-  JavaThread* thread = JavaThread::current();
-  address pc  = thread->saved_exception_pc();
-  address npc = thread->saved_exception_npc();
-  // pc is the instruction which we must emulate
-  // doing a no-op is fine:  return garbage from the load
-
-  // request an async exception
-  thread->set_pending_unsafe_access_error();
-
-  // return address of next instruction to execute
-  return npc;
-}
-
 class StubGenerator: public StubCodeGenerator {
  private:
 
@@ -746,62 +732,6 @@
   Label _atomic_add_stub;  // called from other stubs
 
 
-  //------------------------------------------------------------------------------------------------------------------------
-  // The following routine generates a subroutine to throw an asynchronous
-  // UnknownError when an unsafe access gets a fault that could not be
-  // reasonably prevented by the programmer.  (Example: SIGBUS/OBJERR.)
-  //
-  // Arguments :
-  //
-  //      trapping PC:    O7
-  //
-  // Results:
-  //     posts an asynchronous exception, skips the trapping instruction
-  //
-
-  address generate_handler_for_unsafe_access() {
-    StubCodeMark mark(this, "StubRoutines", "handler_for_unsafe_access");
-    address start = __ pc();
-
-    const int preserve_register_words = (64 * 2);
-    Address preserve_addr(FP, (-preserve_register_words * wordSize) + STACK_BIAS);
-
-    Register Lthread = L7_thread_cache;
-    int i;
-
-    __ save_frame(0);
-    __ mov(G1, L1);
-    __ mov(G2, L2);
-    __ mov(G3, L3);
-    __ mov(G4, L4);
-    __ mov(G5, L5);
-    for (i = 0; i < 64; i += 2) {
-      __ stf(FloatRegisterImpl::D, as_FloatRegister(i), preserve_addr, i * wordSize);
-    }
-
-    address entry_point = CAST_FROM_FN_PTR(address, handle_unsafe_access);
-    BLOCK_COMMENT("call handle_unsafe_access");
-    __ call(entry_point, relocInfo::runtime_call_type);
-    __ delayed()->nop();
-
-    __ mov(L1, G1);
-    __ mov(L2, G2);
-    __ mov(L3, G3);
-    __ mov(L4, G4);
-    __ mov(L5, G5);
-    for (i = 0; i < 64; i += 2) {
-      __ ldf(FloatRegisterImpl::D, preserve_addr, as_FloatRegister(i), i * wordSize);
-    }
-
-    __ verify_thread();
-
-    __ jmp(O0, 0);
-    __ delayed()->restore();
-
-    return start;
-  }
-
-
   // Support for uint StubRoutine::Sparc::partial_subtype_check( Klass sub, Klass super );
   // Arguments :
   //
@@ -5380,9 +5310,6 @@
     StubRoutines::_throw_IncompatibleClassChangeError_entry= generate_throw_exception("IncompatibleClassChangeError throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_IncompatibleClassChangeError));
     StubRoutines::_throw_NullPointerException_at_call_entry= generate_throw_exception("NullPointerException at call throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_NullPointerException_at_call));
 
-    StubRoutines::_handler_for_unsafe_access_entry =
-      generate_handler_for_unsafe_access();
-
     // support for verify_oop (must happen after universe_init)
     StubRoutines::_verify_oop_subroutine_entry     = generate_verify_oop_subroutine();
 
--- a/hotspot/src/cpu/x86/vm/stubGenerator_x86_32.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/cpu/x86/vm/stubGenerator_x86_32.cpp	Tue May 03 08:12:25 2016 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2016, 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
@@ -63,21 +63,6 @@
 // -------------------------------------------------------------------------------------------------------------------------
 // Stub Code definitions
 
-static address handle_unsafe_access() {
-  JavaThread* thread = JavaThread::current();
-  address pc  = thread->saved_exception_pc();
-  // pc is the instruction which we must emulate
-  // doing a no-op is fine:  return garbage from the load
-  // therefore, compute npc
-  address npc = Assembler::locate_next_instruction(pc);
-
-  // request an async exception
-  thread->set_pending_unsafe_access_error();
-
-  // return address of next instruction to execute
-  return npc;
-}
-
 class StubGenerator: public StubCodeGenerator {
  private:
 
@@ -623,27 +608,6 @@
   }
 
 
-  //---------------------------------------------------------------------------
-  // The following routine generates a subroutine to throw an asynchronous
-  // UnknownError when an unsafe access gets a fault that could not be
-  // reasonably prevented by the programmer.  (Example: SIGBUS/OBJERR.)
-  address generate_handler_for_unsafe_access() {
-    StubCodeMark mark(this, "StubRoutines", "handler_for_unsafe_access");
-    address start = __ pc();
-
-    __ push(0);                       // hole for return address-to-be
-    __ pusha();                       // push registers
-    Address next_pc(rsp, RegisterImpl::number_of_registers * BytesPerWord);
-    BLOCK_COMMENT("call handle_unsafe_access");
-    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, handle_unsafe_access)));
-    __ movptr(next_pc, rax);          // stuff next address
-    __ popa();
-    __ ret(0);                        // jump to next address
-
-    return start;
-  }
-
-
   //----------------------------------------------------------------------------------------------------
   // Non-destructive plausibility checks for oops
 
@@ -3865,9 +3829,6 @@
     // These are currently used by Solaris/Intel
     StubRoutines::_atomic_xchg_entry            = generate_atomic_xchg();
 
-    StubRoutines::_handler_for_unsafe_access_entry =
-      generate_handler_for_unsafe_access();
-
     // platform dependent
     create_control_words();
 
--- a/hotspot/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Tue May 03 08:12:25 2016 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2016, 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
@@ -61,21 +61,6 @@
 
 // Stub Code definitions
 
-static address handle_unsafe_access() {
-  JavaThread* thread = JavaThread::current();
-  address pc = thread->saved_exception_pc();
-  // pc is the instruction which we must emulate
-  // doing a no-op is fine:  return garbage from the load
-  // therefore, compute npc
-  address npc = Assembler::locate_next_instruction(pc);
-
-  // request an async exception
-  thread->set_pending_unsafe_access_error();
-
-  // return address of next instruction to execute
-  return npc;
-}
-
 class StubGenerator: public StubCodeGenerator {
  private:
 
@@ -989,32 +974,6 @@
     return start;
   }
 
-  // The following routine generates a subroutine to throw an
-  // asynchronous UnknownError when an unsafe access gets a fault that
-  // could not be reasonably prevented by the programmer.  (Example:
-  // SIGBUS/OBJERR.)
-  address generate_handler_for_unsafe_access() {
-    StubCodeMark mark(this, "StubRoutines", "handler_for_unsafe_access");
-    address start = __ pc();
-
-    __ push(0);                       // hole for return address-to-be
-    __ pusha();                       // push registers
-    Address next_pc(rsp, RegisterImpl::number_of_registers * BytesPerWord);
-
-    // FIXME: this probably needs alignment logic
-
-    __ subptr(rsp, frame::arg_reg_save_area_bytes);
-    BLOCK_COMMENT("call handle_unsafe_access");
-    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, handle_unsafe_access)));
-    __ addptr(rsp, frame::arg_reg_save_area_bytes);
-
-    __ movptr(next_pc, rax);          // stuff next address
-    __ popa();
-    __ ret(0);                        // jump to next address
-
-    return start;
-  }
-
   // Non-destructive plausibility checks for oops
   //
   // Arguments:
@@ -5136,9 +5095,6 @@
     StubRoutines::_atomic_add_ptr_entry      = generate_atomic_add_ptr();
     StubRoutines::_fence_entry               = generate_orderaccess_fence();
 
-    StubRoutines::_handler_for_unsafe_access_entry =
-      generate_handler_for_unsafe_access();
-
     // platform dependent
     StubRoutines::x86::_get_previous_fp_entry = generate_get_previous_fp();
     StubRoutines::x86::_get_previous_sp_entry = generate_get_previous_sp();
--- a/hotspot/src/cpu/zero/vm/stubGenerator_zero.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/cpu/zero/vm/stubGenerator_zero.cpp	Tue May 03 08:12:25 2016 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2007, 2008, 2010, 2015 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -261,10 +261,6 @@
     StubRoutines::_atomic_add_entry          = ShouldNotCallThisStub();
     StubRoutines::_atomic_add_ptr_entry      = ShouldNotCallThisStub();
     StubRoutines::_fence_entry               = ShouldNotCallThisStub();
-
-    // amd64 does this here, sparc does it in generate_all()
-    StubRoutines::_handler_for_unsafe_access_entry =
-      ShouldNotCallThisStub();
   }
 
   void generate_all() {
--- a/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp	Tue May 03 08:12:25 2016 -0700
@@ -392,11 +392,9 @@
         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
         CompiledMethod* nm = cb->as_compiled_method_or_null();
         if (nm != NULL && nm->has_unsafe_access()) {
-          // We don't really need a stub here! Just set the pending exeption and
-          // continue at the next instruction after the faulting read. Returning
-          // garbage from this read is ok.
-          thread->set_pending_unsafe_access_error();
-          os::Aix::ucontext_set_pc(uc, pc + 4);
+          address next_pc = pc + 4;
+          next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
+          os::Aix::ucontext_set_pc(uc, next_pc);
           return 1;
         }
       }
@@ -415,11 +413,9 @@
       }
       else if (thread->thread_state() == _thread_in_vm &&
                sig == SIGBUS && thread->doing_unsafe_access()) {
-        // We don't really need a stub here! Just set the pending exeption and
-        // continue at the next instruction after the faulting read. Returning
-        // garbage from this read is ok.
-        thread->set_pending_unsafe_access_error();
-        os::Aix::ucontext_set_pc(uc, pc + 4);
+        address next_pc = pc + 4;
+        next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
+        os::Aix::ucontext_set_pc(uc, next_pc);
         return 1;
       }
     }
--- a/hotspot/src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp	Tue May 03 08:12:25 2016 -0700
@@ -584,7 +584,8 @@
         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
         CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
         if (nm != NULL && nm->has_unsafe_access()) {
-          stub = StubRoutines::handler_for_unsafe_access();
+          address next_pc = Assembler::locate_next_instruction(pc);
+          stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
         }
       }
       else
@@ -655,7 +656,8 @@
     } else if (thread->thread_state() == _thread_in_vm &&
                sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
                thread->doing_unsafe_access()) {
-        stub = StubRoutines::handler_for_unsafe_access();
+        address next_pc = Assembler::locate_next_instruction(pc);
+        stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
     }
 
     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
--- a/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/linux_aarch64/vm/os_linux_aarch64.cpp	Tue May 03 08:12:25 2016 -0700
@@ -226,23 +226,6 @@
 extern "C" void FetchNResume () ;
 #endif
 
-// An operation in Unsafe has faulted.  We're going to return to the
-// instruction after the faulting load or store.  We also set
-// pending_unsafe_access_error so that at some point in the future our
-// user will get a helpful message.
-static address handle_unsafe_access(JavaThread* thread, address pc) {
-  // pc is the instruction which we must emulate
-  // doing a no-op is fine:  return garbage from the load
-  // therefore, compute npc
-  address npc = pc + NativeCall::instruction_size;
-
-  // request an async exception
-  thread->set_pending_unsafe_access_error();
-
-  // return address of next instruction to execute
-  return npc;
-}
-
 extern "C" JNIEXPORT int
 JVM_handle_linux_signal(int sig,
                         siginfo_t* info,
@@ -387,7 +370,8 @@
         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
         CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
         if (nm != NULL && nm->has_unsafe_access()) {
-          stub = handle_unsafe_access(thread, pc);
+          address next_pc = pc + NativeCall::instruction_size;
+          stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
         }
       }
       else
@@ -408,7 +392,8 @@
     } else if (thread->thread_state() == _thread_in_vm &&
                sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
                thread->doing_unsafe_access()) {
-        stub = handle_unsafe_access(thread, pc);
+      address next_pc = pc + NativeCall::instruction_size;
+      stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
     }
 
     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
--- a/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp	Tue May 03 08:12:25 2016 -0700
@@ -366,11 +366,9 @@
         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
         CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
         if (nm != NULL && nm->has_unsafe_access()) {
-          // We don't really need a stub here! Just set the pending exeption and
-          // continue at the next instruction after the faulting read. Returning
-          // garbage from this read is ok.
-          thread->set_pending_unsafe_access_error();
-          os::Linux::ucontext_set_pc(uc, pc + 4);
+          address next_pc = pc + 4;
+          next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
+          os::Linux::ucontext_set_pc(uc, next_pc);
           return true;
         }
       }
@@ -385,10 +383,8 @@
       }
       else if (thread->thread_state() == _thread_in_vm &&
                sig == SIGBUS && thread->doing_unsafe_access()) {
-        // We don't really need a stub here! Just set the pending exeption and
-        // continue at the next instruction after the faulting read. Returning
-        // garbage from this read is ok.
-        thread->set_pending_unsafe_access_error();
+        address next_pc = pc + 4;
+        next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
         os::Linux::ucontext_set_pc(uc, pc + 4);
         return true;
       }
--- a/hotspot/src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp	Tue May 03 08:12:25 2016 -0700
@@ -433,14 +433,14 @@
   return false;
 }
 
-inline static bool checkByteBuffer(address pc, address* stub) {
+inline static bool checkByteBuffer(address pc, address npc, address* stub) {
   // BugId 4454115: A read from a MappedByteBuffer can fault
   // here if the underlying file has been truncated.
   // Do not crash the VM in such a case.
   CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
   CompiledMethod* nm = cb->as_compiled_method_or_null();
   if (nm != NULL && nm->has_unsafe_access()) {
-    *stub = StubRoutines::handler_for_unsafe_access();
+    *stub = SharedRuntime::handle_unsafe_access(thread, npc);
     return true;
   }
   return false;
@@ -613,7 +613,7 @@
     if (sig == SIGBUS &&
         thread->thread_state() == _thread_in_vm &&
         thread->doing_unsafe_access()) {
-      stub = StubRoutines::handler_for_unsafe_access();
+      stub = SharedRuntime::handle_unsafe_access(thread, npc);
     }
 
     if (thread->thread_state() == _thread_in_Java) {
@@ -625,7 +625,7 @@
           break;
         }
 
-        if ((sig == SIGBUS) && checkByteBuffer(pc, &stub)) {
+        if ((sig == SIGBUS) && checkByteBuffer(pc, npc, &stub)) {
           break;
         }
 
--- a/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Tue May 03 08:12:25 2016 -0700
@@ -420,7 +420,8 @@
         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
         CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
         if (nm != NULL && nm->has_unsafe_access()) {
-          stub = StubRoutines::handler_for_unsafe_access();
+          address next_pc = Assembler::locate_next_instruction(pc);
+          stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
         }
       }
       else
@@ -469,7 +470,8 @@
     } else if (thread->thread_state() == _thread_in_vm &&
                sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
                thread->doing_unsafe_access()) {
-        stub = StubRoutines::handler_for_unsafe_access();
+        address next_pc = Assembler::locate_next_instruction(pc);
+        stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
     }
 
     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
--- a/hotspot/src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp	Tue May 03 08:12:25 2016 -0700
@@ -441,7 +441,7 @@
 
     if (thread->thread_state() == _thread_in_vm) {
       if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
-        stub = StubRoutines::handler_for_unsafe_access();
+        stub = SharedRuntime::handle_unsafe_access(thread, npc);
       }
     }
 
@@ -480,7 +480,7 @@
         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
         CompiledMethod* nm = cb->as_compiled_method_or_null();
         if (nm != NULL && nm->has_unsafe_access()) {
-          stub = StubRoutines::handler_for_unsafe_access();
+          stub = SharedRuntime::handle_unsafe_access(thread, npc);
         }
       }
 
--- a/hotspot/src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp	Tue May 03 08:12:25 2016 -0700
@@ -503,7 +503,8 @@
 
     if (thread->thread_state() == _thread_in_vm) {
       if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
-        stub = StubRoutines::handler_for_unsafe_access();
+        address next_pc = Assembler::locate_next_instruction(pc);
+        stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
       }
     }
 
@@ -520,7 +521,8 @@
         if (cb != NULL) {
           CompiledMethod* nm = cb->as_compiled_method_or_null();
           if (nm != NULL && nm->has_unsafe_access()) {
-            stub = StubRoutines::handler_for_unsafe_access();
+            address next_pc = Assembler::locate_next_instruction(pc);
+            stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
           }
         }
       }
--- a/hotspot/src/share/vm/runtime/sharedRuntime.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/share/vm/runtime/sharedRuntime.cpp	Tue May 03 08:12:25 2016 -0700
@@ -1762,6 +1762,21 @@
   return callee_method;
 }
 
+address SharedRuntime::handle_unsafe_access(JavaThread* thread, address next_pc) {
+  // The faulting unsafe accesses should be changed to throw the error
+  // synchronously instead. Meanwhile the faulting instruction will be
+  // skipped over (effectively turning it into a no-op) and an
+  // asynchronous exception will be raised which the thread will
+  // handle at a later point. If the instruction is a load it will
+  // return garbage.
+
+  // Request an async exception.
+  thread->set_pending_unsafe_access_error();
+
+  // Return address of next instruction to execute.
+  return next_pc;
+}
+
 #ifdef ASSERT
 void SharedRuntime::check_member_name_argument_is_last_argument(const methodHandle& method,
                                                                 const BasicType* sig_bt,
--- a/hotspot/src/share/vm/runtime/sharedRuntime.hpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/share/vm/runtime/sharedRuntime.hpp	Tue May 03 08:12:25 2016 -0700
@@ -522,6 +522,8 @@
   static address handle_wrong_method_abstract(JavaThread* thread);
   static address handle_wrong_method_ic_miss(JavaThread* thread);
 
+  static address handle_unsafe_access(JavaThread* thread, address next_pc);
+
 #ifndef PRODUCT
 
   // Collect and print inline cache miss statistics
--- a/hotspot/src/share/vm/runtime/stubRoutines.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/share/vm/runtime/stubRoutines.cpp	Tue May 03 08:12:25 2016 -0700
@@ -55,7 +55,6 @@
 address StubRoutines::_throw_NullPointerException_at_call_entry = NULL;
 address StubRoutines::_throw_StackOverflowError_entry           = NULL;
 address StubRoutines::_throw_delayed_StackOverflowError_entry   = NULL;
-address StubRoutines::_handler_for_unsafe_access_entry          = NULL;
 jint    StubRoutines::_verify_oop_count                         = 0;
 address StubRoutines::_verify_oop_subroutine_entry              = NULL;
 address StubRoutines::_atomic_xchg_entry                        = NULL;
--- a/hotspot/src/share/vm/runtime/stubRoutines.hpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/share/vm/runtime/stubRoutines.hpp	Tue May 03 08:12:25 2016 -0700
@@ -111,7 +111,6 @@
   static address _throw_NullPointerException_at_call_entry;
   static address _throw_StackOverflowError_entry;
   static address _throw_delayed_StackOverflowError_entry;
-  static address _handler_for_unsafe_access_entry;
 
   static address _atomic_xchg_entry;
   static address _atomic_xchg_ptr_entry;
@@ -288,10 +287,6 @@
   static address throw_StackOverflowError_entry()          { return _throw_StackOverflowError_entry; }
   static address throw_delayed_StackOverflowError_entry()  { return _throw_delayed_StackOverflowError_entry; }
 
-  // Exceptions during unsafe access - should throw Java exception rather
-  // than crash.
-  static address handler_for_unsafe_access()               { return _handler_for_unsafe_access_entry; }
-
   static address atomic_xchg_entry()                       { return _atomic_xchg_entry; }
   static address atomic_xchg_ptr_entry()                   { return _atomic_xchg_ptr_entry; }
   static address atomic_store_entry()                      { return _atomic_store_entry; }