Mercurial > jdk8-mips64-public > hotspot / changeset

     1.1 --- a/src/cpu/x86/vm/c1_Runtime1_x86.cpp	Mon Jun 19 22:49:52 2017 +0000
     1.2 +++ b/src/cpu/x86/vm/c1_Runtime1_x86.cpp	Mon Jun 26 02:04:40 2017 -0700
     1.3 @@ -98,7 +98,7 @@
     1.4    }
     1.5    pop(rax);
     1.6  #endif
     1.7 -  reset_last_Java_frame(thread, true, align_stack);
     1.8 +  reset_last_Java_frame(thread, true);
     1.9  
    1.10    // discard thread and arguments
    1.11    NOT_LP64(addptr(rsp, num_rt_args()*BytesPerWord));
    1.12 @@ -882,7 +882,7 @@
    1.13    }
    1.14    __ pop(rax);
    1.15  #endif
    1.16 -  __ reset_last_Java_frame(thread, true, false);
    1.17 +  __ reset_last_Java_frame(thread, true);
    1.18  #ifndef _LP64
    1.19    __ pop(rcx); // discard thread arg
    1.20    __ pop(rcx); // discard dummy

     2.1 --- a/src/cpu/x86/vm/frame_x86.cpp	Mon Jun 19 22:49:52 2017 +0000
     2.2 +++ b/src/cpu/x86/vm/frame_x86.cpp	Mon Jun 26 02:04:40 2017 -0700
     2.3 @@ -370,13 +370,16 @@
     2.4    JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
     2.5    assert(!entry_frame_is_first(), "next Java fp must be non zero");
     2.6    assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
     2.7 +  // Since we are walking the stack now this nested anchor is obviously walkable
     2.8 +  // even if it wasn't when it was stacked.
     2.9 +  if (!jfa->walkable()) {
    2.10 +    // Capture _last_Java_pc (if needed) and mark anchor walkable.
    2.11 +    jfa->capture_last_Java_pc();
    2.12 +  }
    2.13    map->clear();
    2.14    assert(map->include_argument_oops(), "should be set by clear");
    2.15 -  if (jfa->last_Java_pc() != NULL ) {
    2.16 -    frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
    2.17 -    return fr;
    2.18 -  }
    2.19 -  frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());
    2.20 +  assert(jfa->last_Java_pc() != NULL, "not walkable");
    2.21 +  frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
    2.22    return fr;
    2.23  }
    2.24  
    2.25 @@ -714,3 +717,21 @@
    2.26    init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
    2.27  }
    2.28  #endif
    2.29 +
    2.30 +void JavaFrameAnchor::make_walkable(JavaThread* thread) {
    2.31 +  // last frame set?
    2.32 +  if (last_Java_sp() == NULL) return;
    2.33 +  // already walkable?
    2.34 +  if (walkable()) return;
    2.35 +  assert(Thread::current() == (Thread*)thread, "not current thread");
    2.36 +  assert(last_Java_sp() != NULL, "not called from Java code?");
    2.37 +  assert(last_Java_pc() == NULL, "already walkable");
    2.38 +  capture_last_Java_pc();
    2.39 +  assert(walkable(), "something went wrong");
    2.40 +}
    2.41 +
    2.42 +void JavaFrameAnchor::capture_last_Java_pc() {
    2.43 +  assert(_last_Java_sp != NULL, "no last frame set");
    2.44 +  assert(_last_Java_pc == NULL, "already walkable");
    2.45 +  _last_Java_pc = (address)_last_Java_sp[-1];
    2.46 +}

     3.1 --- a/src/cpu/x86/vm/frame_x86.inline.hpp	Mon Jun 19 22:49:52 2017 +0000
     3.2 +++ b/src/cpu/x86/vm/frame_x86.inline.hpp	Mon Jun 26 02:04:40 2017 -0700
     3.3 @@ -96,6 +96,7 @@
     3.4    // call a specialized frame constructor instead of this one.
     3.5    // Then we could use the assert below. However this assert is of somewhat dubious
     3.6    // value.
     3.7 +  // UPDATE: this constructor is only used by trace_method_handle_stub() now.
     3.8    // assert(_pc != NULL, "no pc?");
     3.9  
    3.10    _cb = CodeCache::find_blob(_pc);

     4.1 --- a/src/cpu/x86/vm/javaFrameAnchor_x86.hpp	Mon Jun 19 22:49:52 2017 +0000
     4.2 +++ b/src/cpu/x86/vm/javaFrameAnchor_x86.hpp	Mon Jun 26 02:04:40 2017 -0700
     4.3 @@ -62,10 +62,9 @@
     4.4      _last_Java_sp = src->_last_Java_sp;
     4.5    }
     4.6  
     4.7 -  // Always walkable
     4.8 -  bool walkable(void) { return true; }
     4.9 -  // Never any thing to do since we are always walkable and can find address of return addresses
    4.10 -  void make_walkable(JavaThread* thread) { }
    4.11 +  bool walkable(void)                            { return _last_Java_sp != NULL && _last_Java_pc != NULL; }
    4.12 +  void make_walkable(JavaThread* thread);
    4.13 +  void capture_last_Java_pc(void);
    4.14  
    4.15    intptr_t* last_Java_sp(void) const             { return _last_Java_sp; }
    4.16  

     5.1 --- a/src/cpu/x86/vm/macroAssembler_x86.cpp	Mon Jun 19 22:49:52 2017 +0000
     5.2 +++ b/src/cpu/x86/vm/macroAssembler_x86.cpp	Mon Jun 26 02:04:40 2017 -0700
     5.3 @@ -748,8 +748,7 @@
     5.4    }
     5.5  }
     5.6  
     5.7 -void MacroAssembler::reset_last_Java_frame(bool clear_fp,
     5.8 -                                           bool clear_pc) {
     5.9 +void MacroAssembler::reset_last_Java_frame(bool clear_fp) {
    5.10    // we must set sp to zero to clear frame
    5.11    movptr(Address(r15_thread, JavaThread::last_Java_sp_offset()), NULL_WORD);
    5.12    // must clear fp, so that compiled frames are not confused; it is
    5.13 @@ -758,9 +757,8 @@
    5.14      movptr(Address(r15_thread, JavaThread::last_Java_fp_offset()), NULL_WORD);
    5.15    }
    5.16  
    5.17 -  if (clear_pc) {
    5.18 -    movptr(Address(r15_thread, JavaThread::last_Java_pc_offset()), NULL_WORD);
    5.19 -  }
    5.20 +  // Always clear the pc because it could have been set by make_walkable()
    5.21 +  movptr(Address(r15_thread, JavaThread::last_Java_pc_offset()), NULL_WORD);
    5.22  }
    5.23  
    5.24  void MacroAssembler::set_last_Java_frame(Register last_java_sp,
    5.25 @@ -2561,7 +2559,7 @@
    5.26    }
    5.27    // reset last Java frame
    5.28    // Only interpreter should have to clear fp
    5.29 -  reset_last_Java_frame(java_thread, true, false);
    5.30 +  reset_last_Java_frame(java_thread, true);
    5.31  
    5.32  #ifndef CC_INTERP
    5.33     // C++ interp handles this in the interpreter
    5.34 @@ -3808,7 +3806,7 @@
    5.35    pusha();
    5.36  }
    5.37  
    5.38 -void MacroAssembler::reset_last_Java_frame(Register java_thread, bool clear_fp, bool clear_pc) {
    5.39 +void MacroAssembler::reset_last_Java_frame(Register java_thread, bool clear_fp) {
    5.40    // determine java_thread register
    5.41    if (!java_thread->is_valid()) {
    5.42      java_thread = rdi;
    5.43 @@ -3820,8 +3818,8 @@
    5.44      movptr(Address(java_thread, JavaThread::last_Java_fp_offset()), NULL_WORD);
    5.45    }
    5.46  
    5.47 -  if (clear_pc)
    5.48 -    movptr(Address(java_thread, JavaThread::last_Java_pc_offset()), NULL_WORD);
    5.49 +  // Always clear the pc because it could have been set by make_walkable()
    5.50 +  movptr(Address(java_thread, JavaThread::last_Java_pc_offset()), NULL_WORD);
    5.51  
    5.52  }
    5.53  

     6.1 --- a/src/cpu/x86/vm/macroAssembler_x86.hpp	Mon Jun 19 22:49:52 2017 +0000
     6.2 +++ b/src/cpu/x86/vm/macroAssembler_x86.hpp	Mon Jun 26 02:04:40 2017 -0700
     6.3 @@ -289,10 +289,10 @@
     6.4                             Register last_java_fp,
     6.5                             address last_java_pc);
     6.6  
     6.7 -  void reset_last_Java_frame(Register thread, bool clear_fp, bool clear_pc);
     6.8 +  void reset_last_Java_frame(Register thread, bool clear_fp);
     6.9  
    6.10    // thread in the default location (r15_thread on 64bit)
    6.11 -  void reset_last_Java_frame(bool clear_fp, bool clear_pc);
    6.12 +  void reset_last_Java_frame(bool clear_fp);
    6.13  
    6.14    // Stores
    6.15    void store_check(Register obj);                // store check for obj - register is destroyed afterwards

     7.1 --- a/src/cpu/x86/vm/runtime_x86_32.cpp	Mon Jun 19 22:49:52 2017 +0000
     7.2 +++ b/src/cpu/x86/vm/runtime_x86_32.cpp	Mon Jun 26 02:04:40 2017 -0700
     7.3 @@ -116,7 +116,7 @@
     7.4    // No registers to map, rbp is known implicitly
     7.5    oop_maps->add_gc_map( __ pc() - start,  new OopMap( framesize, 0 ));
     7.6    __ get_thread(rcx);
     7.7 -  __ reset_last_Java_frame(rcx, false, false);
     7.8 +  __ reset_last_Java_frame(rcx, false);
     7.9  
    7.10    // Restore callee-saved registers
    7.11    __ movptr(rbp, Address(rsp, rbp_off * wordSize));

     8.1 --- a/src/cpu/x86/vm/sharedRuntime_x86_32.cpp	Mon Jun 19 22:49:52 2017 +0000
     8.2 +++ b/src/cpu/x86/vm/sharedRuntime_x86_32.cpp	Mon Jun 26 02:04:40 2017 -0700
     8.3 @@ -1333,7 +1333,7 @@
     8.4    __ increment(rsp, wordSize);
     8.5  
     8.6    __ get_thread(thread);
     8.7 -  __ reset_last_Java_frame(thread, false, true);
     8.8 +  __ reset_last_Java_frame(thread, false);
     8.9  
    8.10    save_or_restore_arguments(masm, stack_slots, total_in_args,
    8.11                              arg_save_area, NULL, in_regs, in_sig_bt);
    8.12 @@ -2251,7 +2251,7 @@
    8.13  
    8.14    // We can finally stop using that last_Java_frame we setup ages ago
    8.15  
    8.16 -  __ reset_last_Java_frame(thread, false, true);
    8.17 +  __ reset_last_Java_frame(thread, false);
    8.18  
    8.19    // Unpack oop result
    8.20    if (ret_type == T_OBJECT || ret_type == T_ARRAY) {
    8.21 @@ -2951,7 +2951,7 @@
    8.22    __ pop(rcx);
    8.23  
    8.24    __ get_thread(rcx);
    8.25 -  __ reset_last_Java_frame(rcx, false, false);
    8.26 +  __ reset_last_Java_frame(rcx, false);
    8.27  
    8.28    // Load UnrollBlock into EDI
    8.29    __ mov(rdi, rax);
    8.30 @@ -3117,7 +3117,7 @@
    8.31    __ push(rax);
    8.32  
    8.33    __ get_thread(rcx);
    8.34 -  __ reset_last_Java_frame(rcx, false, false);
    8.35 +  __ reset_last_Java_frame(rcx, false);
    8.36  
    8.37    // Collect return values
    8.38    __ movptr(rax,Address(rsp, (RegisterSaver::raxOffset() + additional_words + 1)*wordSize));
    8.39 @@ -3219,7 +3219,7 @@
    8.40  
    8.41    __ get_thread(rcx);
    8.42  
    8.43 -  __ reset_last_Java_frame(rcx, false, false);
    8.44 +  __ reset_last_Java_frame(rcx, false);
    8.45  
    8.46    // Load UnrollBlock into EDI
    8.47    __ movptr(rdi, rax);
    8.48 @@ -3331,7 +3331,7 @@
    8.49    oop_maps->add_gc_map( __ pc()-start, new OopMap( framesize, 0 ) );
    8.50  
    8.51    __ get_thread(rdi);
    8.52 -  __ reset_last_Java_frame(rdi, true, false);
    8.53 +  __ reset_last_Java_frame(rdi, true);
    8.54  
    8.55    // Pop self-frame.
    8.56    __ leave();     // Epilog!
    8.57 @@ -3426,7 +3426,7 @@
    8.58  
    8.59    // Clear last_Java_sp again
    8.60    __ get_thread(java_thread);
    8.61 -  __ reset_last_Java_frame(java_thread, false, false);
    8.62 +  __ reset_last_Java_frame(java_thread, false);
    8.63  
    8.64    __ cmpptr(Address(java_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
    8.65    __ jcc(Assembler::equal, noException);
    8.66 @@ -3501,7 +3501,7 @@
    8.67    __ addptr(rsp, wordSize);
    8.68  
    8.69    // clear last_Java_sp
    8.70 -  __ reset_last_Java_frame(thread, true, false);
    8.71 +  __ reset_last_Java_frame(thread, true);
    8.72    // check for pending exceptions
    8.73    Label pending;
    8.74    __ cmpptr(Address(thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);

     9.1 --- a/src/cpu/x86/vm/sharedRuntime_x86_64.cpp	Mon Jun 19 22:49:52 2017 +0000
     9.2 +++ b/src/cpu/x86/vm/sharedRuntime_x86_64.cpp	Mon Jun 26 02:04:40 2017 -0700
     9.3 @@ -1388,7 +1388,7 @@
     9.4    __ mov(rsp, r12); // restore sp
     9.5    __ reinit_heapbase();
     9.6  
     9.7 -  __ reset_last_Java_frame(false, true);
     9.8 +  __ reset_last_Java_frame(false);
     9.9  
    9.10    save_or_restore_arguments(masm, stack_slots, total_in_args,
    9.11                              arg_save_area, NULL, in_regs, in_sig_bt);
    9.12 @@ -2497,7 +2497,7 @@
    9.13      restore_native_result(masm, ret_type, stack_slots);
    9.14    }
    9.15  
    9.16 -  __ reset_last_Java_frame(false, true);
    9.17 +  __ reset_last_Java_frame(false);
    9.18  
    9.19    // Unpack oop result
    9.20    if (ret_type == T_OBJECT || ret_type == T_ARRAY) {
    9.21 @@ -3435,7 +3435,7 @@
    9.22    // find any register it might need.
    9.23    oop_maps->add_gc_map(__ pc() - start, map);
    9.24  
    9.25 -  __ reset_last_Java_frame(false, false);
    9.26 +  __ reset_last_Java_frame(false);
    9.27  
    9.28    // Load UnrollBlock* into rdi
    9.29    __ mov(rdi, rax);
    9.30 @@ -3592,7 +3592,7 @@
    9.31                         new OopMap( frame_size_in_words, 0 ));
    9.32  
    9.33    // Clear fp AND pc
    9.34 -  __ reset_last_Java_frame(true, true);
    9.35 +  __ reset_last_Java_frame(true);
    9.36  
    9.37    // Collect return values
    9.38    __ movdbl(xmm0, Address(rsp, RegisterSaver::xmm0_offset_in_bytes()));
    9.39 @@ -3662,7 +3662,7 @@
    9.40  
    9.41    oop_maps->add_gc_map(__ pc() - start, map);
    9.42  
    9.43 -  __ reset_last_Java_frame(false, false);
    9.44 +  __ reset_last_Java_frame(false);
    9.45  
    9.46    // Load UnrollBlock* into rdi
    9.47    __ mov(rdi, rax);
    9.48 @@ -3775,7 +3775,7 @@
    9.49    oop_maps->add_gc_map(the_pc - start, new OopMap(SimpleRuntimeFrame::framesize, 0));
    9.50  
    9.51    // Clear fp AND pc
    9.52 -  __ reset_last_Java_frame(true, true);
    9.53 +  __ reset_last_Java_frame(true);
    9.54  
    9.55    // Pop self-frame.
    9.56    __ leave();                 // Epilog
    9.57 @@ -3858,7 +3858,7 @@
    9.58  
    9.59    Label noException;
    9.60  
    9.61 -  __ reset_last_Java_frame(false, false);
    9.62 +  __ reset_last_Java_frame(false);
    9.63  
    9.64    __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
    9.65    __ jcc(Assembler::equal, noException);
    9.66 @@ -3928,7 +3928,7 @@
    9.67    // rax contains the address we are going to jump to assuming no exception got installed
    9.68  
    9.69    // clear last_Java_sp
    9.70 -  __ reset_last_Java_frame(false, false);
    9.71 +  __ reset_last_Java_frame(false);
    9.72    // check for pending exceptions
    9.73    Label pending;
    9.74    __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
    9.75 @@ -4309,7 +4309,7 @@
    9.76  
    9.77    oop_maps->add_gc_map(the_pc - start, new OopMap(SimpleRuntimeFrame::framesize, 0));
    9.78  
    9.79 -  __ reset_last_Java_frame(false, true);
    9.80 +  __ reset_last_Java_frame(false);
    9.81  
    9.82    // Restore callee-saved registers
    9.83  

    10.1 --- a/src/cpu/x86/vm/stubGenerator_x86_32.cpp	Mon Jun 19 22:49:52 2017 +0000
    10.2 +++ b/src/cpu/x86/vm/stubGenerator_x86_32.cpp	Mon Jun 26 02:04:40 2017 -0700
    10.3 @@ -2901,7 +2901,7 @@
    10.4      // however can use the register value directly if it is callee saved.
    10.5      __ get_thread(java_thread);
    10.6  
    10.7 -    __ reset_last_Java_frame(java_thread, true, false);
    10.8 +    __ reset_last_Java_frame(java_thread, true);
    10.9  
   10.10      __ leave(); // required for proper stackwalking of RuntimeStub frame
   10.11  

    11.1 --- a/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Mon Jun 19 22:49:52 2017 +0000
    11.2 +++ b/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Mon Jun 26 02:04:40 2017 -0700
    11.3 @@ -3923,7 +3923,7 @@
    11.4  
    11.5      oop_maps->add_gc_map(the_pc - start, map);
    11.6  
    11.7 -    __ reset_last_Java_frame(true, true);
    11.8 +    __ reset_last_Java_frame(true);
    11.9  
   11.10      __ leave(); // required for proper stackwalking of RuntimeStub frame
   11.11  

    12.1 --- a/src/cpu/x86/vm/templateInterpreter_x86_32.cpp	Mon Jun 19 22:49:52 2017 +0000
    12.2 +++ b/src/cpu/x86/vm/templateInterpreter_x86_32.cpp	Mon Jun 26 02:04:40 2017 -0700
    12.3 @@ -1289,7 +1289,7 @@
    12.4    // change thread state
    12.5    __ movl(Address(thread, JavaThread::thread_state_offset()), _thread_in_Java);
    12.6  
    12.7 -  __ reset_last_Java_frame(thread, true, true);
    12.8 +  __ reset_last_Java_frame(thread, true);
    12.9  
   12.10    // reset handle block
   12.11    __ movptr(t, Address(thread, JavaThread::active_handles_offset()));
   12.12 @@ -1819,7 +1819,7 @@
   12.13    __ set_last_Java_frame(thread, noreg, rbp, __ pc());
   12.14    __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::popframe_move_outgoing_args), thread, rax, rbx);
   12.15    __ get_thread(thread);
   12.16 -  __ reset_last_Java_frame(thread, true, true);
   12.17 +  __ reset_last_Java_frame(thread, true);
   12.18    // Restore the last_sp and null it out
   12.19    __ movptr(rsp, Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize));
   12.20    __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), NULL_WORD);

    13.1 --- a/src/cpu/x86/vm/templateInterpreter_x86_64.cpp	Mon Jun 19 22:49:52 2017 +0000
    13.2 +++ b/src/cpu/x86/vm/templateInterpreter_x86_64.cpp	Mon Jun 26 02:04:40 2017 -0700
    13.3 @@ -1262,7 +1262,7 @@
    13.4    __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_Java);
    13.5  
    13.6    // reset_last_Java_frame
    13.7 -  __ reset_last_Java_frame(true, true);
    13.8 +  __ reset_last_Java_frame(r15_thread, true);
    13.9  
   13.10    // reset handle block
   13.11    __ movptr(t, Address(r15_thread, JavaThread::active_handles_offset()));
   13.12 @@ -1837,7 +1837,7 @@
   13.13    // PC must point into interpreter here
   13.14    __ set_last_Java_frame(noreg, rbp, __ pc());
   13.15    __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::popframe_move_outgoing_args), r15_thread, c_rarg1, c_rarg2);
   13.16 -  __ reset_last_Java_frame(true, true);
   13.17 +  __ reset_last_Java_frame(r15_thread, true);
   13.18    // Restore the last_sp and null it out
   13.19    __ movptr(rsp, Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize));
   13.20    __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD);

    14.1 --- a/src/os_cpu/bsd_x86/vm/thread_bsd_x86.cpp	Mon Jun 19 22:49:52 2017 +0000
    14.2 +++ b/src/os_cpu/bsd_x86/vm/thread_bsd_x86.cpp	Mon Jun 26 02:04:40 2017 -0700
    14.3 @@ -44,7 +44,7 @@
    14.4  
    14.5    // If we have a last_Java_frame, then we should use it even if
    14.6    // isInJava == true.  It should be more reliable than ucontext info.
    14.7 -  if (jt->has_last_Java_frame()) {
    14.8 +  if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
    14.9      *fr_addr = jt->pd_last_frame();
   14.10      return true;
   14.11    }

    15.1 --- a/src/os_cpu/bsd_x86/vm/thread_bsd_x86.hpp	Mon Jun 19 22:49:52 2017 +0000
    15.2 +++ b/src/os_cpu/bsd_x86/vm/thread_bsd_x86.hpp	Mon Jun 26 02:04:40 2017 -0700
    15.3 @@ -32,12 +32,8 @@
    15.4  
    15.5    frame pd_last_frame() {
    15.6      assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
    15.7 -    if (_anchor.last_Java_pc() != NULL) {
    15.8 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
    15.9 -    } else {
   15.10 -      // This will pick up pc from sp
   15.11 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp());
   15.12 -    }
   15.13 +    assert(_anchor.last_Java_pc() != NULL, "not walkable");
   15.14 +    return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
   15.15    }
   15.16  
   15.17   public:

    16.1 --- a/src/os_cpu/linux_x86/vm/thread_linux_x86.cpp	Mon Jun 19 22:49:52 2017 +0000
    16.2 +++ b/src/os_cpu/linux_x86/vm/thread_linux_x86.cpp	Mon Jun 26 02:04:40 2017 -0700
    16.3 @@ -45,7 +45,7 @@
    16.4  
    16.5    // If we have a last_Java_frame, then we should use it even if
    16.6    // isInJava == true.  It should be more reliable than ucontext info.
    16.7 -  if (jt->has_last_Java_frame()) {
    16.8 +  if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
    16.9      *fr_addr = jt->pd_last_frame();
   16.10      return true;
   16.11    }

    17.1 --- a/src/os_cpu/linux_x86/vm/thread_linux_x86.hpp	Mon Jun 19 22:49:52 2017 +0000
    17.2 +++ b/src/os_cpu/linux_x86/vm/thread_linux_x86.hpp	Mon Jun 26 02:04:40 2017 -0700
    17.3 @@ -32,12 +32,8 @@
    17.4  
    17.5    frame pd_last_frame() {
    17.6      assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
    17.7 -    if (_anchor.last_Java_pc() != NULL) {
    17.8 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
    17.9 -    } else {
   17.10 -      // This will pick up pc from sp
   17.11 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp());
   17.12 -    }
   17.13 +    assert(_anchor.last_Java_pc() != NULL, "not walkable");
   17.14 +    return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
   17.15    }
   17.16  
   17.17   public:

    18.1 --- a/src/os_cpu/solaris_x86/vm/thread_solaris_x86.cpp	Mon Jun 19 22:49:52 2017 +0000
    18.2 +++ b/src/os_cpu/solaris_x86/vm/thread_solaris_x86.cpp	Mon Jun 26 02:04:40 2017 -0700
    18.3 @@ -44,9 +44,8 @@
    18.4    assert(this->is_Java_thread(), "must be JavaThread");
    18.5    JavaThread* jt = (JavaThread *)this;
    18.6  
    18.7 -  // last_Java_frame is always walkable and safe use it if we have it
    18.8 -
    18.9 -  if (jt->has_last_Java_frame()) {
   18.10 +  // There is small window where last_Java_frame is not walkable or safe
   18.11 +  if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
   18.12      *fr_addr = jt->pd_last_frame();
   18.13      return true;
   18.14    }

    19.1 --- a/src/os_cpu/solaris_x86/vm/thread_solaris_x86.hpp	Mon Jun 19 22:49:52 2017 +0000
    19.2 +++ b/src/os_cpu/solaris_x86/vm/thread_solaris_x86.hpp	Mon Jun 26 02:04:40 2017 -0700
    19.3 @@ -30,12 +30,8 @@
    19.4  
    19.5    frame pd_last_frame() {
    19.6      assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
    19.7 -    if (_anchor.last_Java_pc() != NULL) {
    19.8 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
    19.9 -    } else {
   19.10 -      // This will pick up pc from sp
   19.11 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp());
   19.12 -    }
   19.13 +    assert(_anchor.last_Java_pc() != NULL, "not walkable");
   19.14 +    return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
   19.15    }
   19.16  
   19.17   public:

    20.1 --- a/src/os_cpu/windows_x86/vm/thread_windows_x86.cpp	Mon Jun 19 22:49:52 2017 +0000
    20.2 +++ b/src/os_cpu/windows_x86/vm/thread_windows_x86.cpp	Mon Jun 26 02:04:40 2017 -0700
    20.3 @@ -47,7 +47,7 @@
    20.4  
    20.5    // If we have a last_Java_frame, then we should use it even if
    20.6    // isInJava == true.  It should be more reliable than CONTEXT info.
    20.7 -  if (jt->has_last_Java_frame()) {
    20.8 +  if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
    20.9      *fr_addr = jt->pd_last_frame();
   20.10      return true;
   20.11    }

    21.1 --- a/src/os_cpu/windows_x86/vm/thread_windows_x86.hpp	Mon Jun 19 22:49:52 2017 +0000
    21.2 +++ b/src/os_cpu/windows_x86/vm/thread_windows_x86.hpp	Mon Jun 26 02:04:40 2017 -0700
    21.3 @@ -32,12 +32,8 @@
    21.4  
    21.5    frame pd_last_frame() {
    21.6      assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
    21.7 -    if (_anchor.last_Java_pc() != NULL) {
    21.8 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
    21.9 -    } else {
   21.10 -      // This will pick up pc from sp
   21.11 -      return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp());
   21.12 -    }
   21.13 +    assert(_anchor.last_Java_pc() != NULL, "not walkable");
   21.14 +    return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
   21.15    }
   21.16  
   21.17   public: