1 /*
2 * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/codeBuffer.hpp"
27 #include "c1/c1_CodeStubs.hpp"
28 #include "c1/c1_Defs.hpp"
29 #include "c1/c1_FrameMap.hpp"
30 #include "c1/c1_LIRAssembler.hpp"
31 #include "c1/c1_MacroAssembler.hpp"
32 #include "c1/c1_Runtime1.hpp"
33 #include "classfile/javaClasses.inline.hpp"
34 #include "classfile/vmClasses.hpp"
35 #include "classfile/vmSymbols.hpp"
36 #include "code/codeBlob.hpp"
37 #include "code/compiledIC.hpp"
38 #include "code/pcDesc.hpp"
39 #include "code/scopeDesc.hpp"
40 #include "code/vtableStubs.hpp"
41 #include "compiler/compilationPolicy.hpp"
42 #include "compiler/disassembler.hpp"
43 #include "compiler/oopMap.hpp"
44 #include "gc/shared/barrierSet.hpp"
45 #include "gc/shared/c1/barrierSetC1.hpp"
46 #include "gc/shared/collectedHeap.hpp"
47 #include "interpreter/bytecode.hpp"
48 #include "interpreter/interpreter.hpp"
49 #include "jfr/support/jfrIntrinsics.hpp"
50 #include "logging/log.hpp"
51 #include "memory/allocation.inline.hpp"
52 #include "memory/oopFactory.hpp"
53 #include "memory/resourceArea.hpp"
54 #include "memory/universe.hpp"
55 #include "oops/access.inline.hpp"
56 #include "oops/klass.inline.hpp"
57 #include "oops/objArrayOop.inline.hpp"
58 #include "oops/objArrayKlass.hpp"
59 #include "oops/oop.inline.hpp"
60 #include "prims/jvmtiExport.hpp"
61 #include "runtime/atomic.hpp"
62 #include "runtime/fieldDescriptor.inline.hpp"
63 #include "runtime/frame.inline.hpp"
64 #include "runtime/handles.inline.hpp"
65 #include "runtime/interfaceSupport.inline.hpp"
66 #include "runtime/javaCalls.hpp"
67 #include "runtime/sharedRuntime.hpp"
68 #include "runtime/stackWatermarkSet.hpp"
69 #include "runtime/stubRoutines.hpp"
70 #include "runtime/threadCritical.hpp"
71 #include "runtime/vframe.inline.hpp"
72 #include "runtime/vframeArray.hpp"
73 #include "runtime/vm_version.hpp"
74 #include "utilities/copy.hpp"
75 #include "utilities/events.hpp"
76
77
78 // Implementation of StubAssembler
79
80 StubAssembler::StubAssembler(CodeBuffer* code, const char * name, int stub_id) : C1_MacroAssembler(code) {
81 _name = name;
82 _must_gc_arguments = false;
83 _frame_size = no_frame_size;
84 _num_rt_args = 0;
85 _stub_id = stub_id;
86 }
87
88
89 void StubAssembler::set_info(const char* name, bool must_gc_arguments) {
90 _name = name;
91 _must_gc_arguments = must_gc_arguments;
92 }
93
94
95 void StubAssembler::set_frame_size(int size) {
96 if (_frame_size == no_frame_size) {
97 _frame_size = size;
98 }
99 assert(_frame_size == size, "can't change the frame size");
100 }
101
102
103 void StubAssembler::set_num_rt_args(int args) {
104 if (_num_rt_args == 0) {
105 _num_rt_args = args;
106 }
107 assert(_num_rt_args == args, "can't change the number of args");
108 }
109
110 // Implementation of Runtime1
111
112 CodeBlob* Runtime1::_blobs[Runtime1::number_of_ids];
113 const char *Runtime1::_blob_names[] = {
114 RUNTIME1_STUBS(STUB_NAME, LAST_STUB_NAME)
115 };
116
117 #ifndef PRODUCT
118 // statistics
119 uint Runtime1::_generic_arraycopystub_cnt = 0;
120 uint Runtime1::_arraycopy_slowcase_cnt = 0;
121 uint Runtime1::_arraycopy_checkcast_cnt = 0;
122 uint Runtime1::_arraycopy_checkcast_attempt_cnt = 0;
123 uint Runtime1::_new_type_array_slowcase_cnt = 0;
124 uint Runtime1::_new_object_array_slowcase_cnt = 0;
125 uint Runtime1::_new_instance_slowcase_cnt = 0;
126 uint Runtime1::_new_multi_array_slowcase_cnt = 0;
127 uint Runtime1::_monitorenter_slowcase_cnt = 0;
128 uint Runtime1::_monitorexit_slowcase_cnt = 0;
129 uint Runtime1::_patch_code_slowcase_cnt = 0;
130 uint Runtime1::_throw_range_check_exception_count = 0;
131 uint Runtime1::_throw_index_exception_count = 0;
132 uint Runtime1::_throw_div0_exception_count = 0;
133 uint Runtime1::_throw_null_pointer_exception_count = 0;
134 uint Runtime1::_throw_class_cast_exception_count = 0;
135 uint Runtime1::_throw_incompatible_class_change_error_count = 0;
136 uint Runtime1::_throw_count = 0;
137
138 static uint _byte_arraycopy_stub_cnt = 0;
139 static uint _short_arraycopy_stub_cnt = 0;
140 static uint _int_arraycopy_stub_cnt = 0;
141 static uint _long_arraycopy_stub_cnt = 0;
142 static uint _oop_arraycopy_stub_cnt = 0;
143
144 address Runtime1::arraycopy_count_address(BasicType type) {
145 switch (type) {
146 case T_BOOLEAN:
147 case T_BYTE: return (address)&_byte_arraycopy_stub_cnt;
148 case T_CHAR:
149 case T_SHORT: return (address)&_short_arraycopy_stub_cnt;
150 case T_FLOAT:
151 case T_INT: return (address)&_int_arraycopy_stub_cnt;
152 case T_DOUBLE:
153 case T_LONG: return (address)&_long_arraycopy_stub_cnt;
154 case T_ARRAY:
155 case T_OBJECT: return (address)&_oop_arraycopy_stub_cnt;
156 default:
157 ShouldNotReachHere();
158 return nullptr;
159 }
160 }
161
162
163 #endif
164
165 // Simple helper to see if the caller of a runtime stub which
166 // entered the VM has been deoptimized
167
168 static bool caller_is_deopted(JavaThread* current) {
169 RegisterMap reg_map(current,
170 RegisterMap::UpdateMap::skip,
171 RegisterMap::ProcessFrames::include,
172 RegisterMap::WalkContinuation::skip);
173 frame runtime_frame = current->last_frame();
174 frame caller_frame = runtime_frame.sender(®_map);
175 assert(caller_frame.is_compiled_frame(), "must be compiled");
176 return caller_frame.is_deoptimized_frame();
177 }
178
179 // Stress deoptimization
180 static void deopt_caller(JavaThread* current) {
181 if (!caller_is_deopted(current)) {
182 RegisterMap reg_map(current,
183 RegisterMap::UpdateMap::skip,
184 RegisterMap::ProcessFrames::include,
185 RegisterMap::WalkContinuation::skip);
186 frame runtime_frame = current->last_frame();
187 frame caller_frame = runtime_frame.sender(®_map);
188 Deoptimization::deoptimize_frame(current, caller_frame.id());
189 assert(caller_is_deopted(current), "Must be deoptimized");
190 }
191 }
192
193 class StubIDStubAssemblerCodeGenClosure: public StubAssemblerCodeGenClosure {
194 private:
195 Runtime1::StubID _id;
196 public:
197 StubIDStubAssemblerCodeGenClosure(Runtime1::StubID id) : _id(id) {}
198 virtual OopMapSet* generate_code(StubAssembler* sasm) {
199 return Runtime1::generate_code_for(_id, sasm);
200 }
201 };
202
203 CodeBlob* Runtime1::generate_blob(BufferBlob* buffer_blob, int stub_id, const char* name, bool expect_oop_map, StubAssemblerCodeGenClosure* cl) {
204 ResourceMark rm;
205 // create code buffer for code storage
206 CodeBuffer code(buffer_blob);
207
208 OopMapSet* oop_maps;
209 int frame_size;
210 bool must_gc_arguments;
211
212 Compilation::setup_code_buffer(&code, 0);
213
214 // create assembler for code generation
215 StubAssembler* sasm = new StubAssembler(&code, name, stub_id);
216 // generate code for runtime stub
217 oop_maps = cl->generate_code(sasm);
218 assert(oop_maps == nullptr || sasm->frame_size() != no_frame_size,
219 "if stub has an oop map it must have a valid frame size");
220 assert(!expect_oop_map || oop_maps != nullptr, "must have an oopmap");
221
222 // align so printing shows nop's instead of random code at the end (SimpleStubs are aligned)
223 sasm->align(BytesPerWord);
224 // make sure all code is in code buffer
225 sasm->flush();
226
227 frame_size = sasm->frame_size();
228 must_gc_arguments = sasm->must_gc_arguments();
229 // create blob - distinguish a few special cases
230 CodeBlob* blob = RuntimeStub::new_runtime_stub(name,
231 &code,
232 CodeOffsets::frame_never_safe,
233 frame_size,
234 oop_maps,
235 must_gc_arguments);
236 assert(blob != nullptr, "blob must exist");
237 return blob;
238 }
239
240 void Runtime1::generate_blob_for(BufferBlob* buffer_blob, StubID id) {
241 assert(0 <= id && id < number_of_ids, "illegal stub id");
242 bool expect_oop_map = true;
243 #ifdef ASSERT
244 // Make sure that stubs that need oopmaps have them
245 switch (id) {
246 // These stubs don't need to have an oopmap
247 case dtrace_object_alloc_id:
248 case slow_subtype_check_id:
249 case fpu2long_stub_id:
250 case unwind_exception_id:
251 case counter_overflow_id:
252 expect_oop_map = false;
253 break;
254 default:
255 break;
256 }
257 #endif
258 StubIDStubAssemblerCodeGenClosure cl(id);
259 CodeBlob* blob = generate_blob(buffer_blob, id, name_for(id), expect_oop_map, &cl);
260 // install blob
261 _blobs[id] = blob;
262 }
263
264 void Runtime1::initialize(BufferBlob* blob) {
265 // platform-dependent initialization
266 initialize_pd();
267 // generate stubs
268 for (int id = 0; id < number_of_ids; id++) generate_blob_for(blob, (StubID)id);
269 // printing
270 #ifndef PRODUCT
271 if (PrintSimpleStubs) {
272 ResourceMark rm;
273 for (int id = 0; id < number_of_ids; id++) {
274 _blobs[id]->print();
275 if (_blobs[id]->oop_maps() != nullptr) {
276 _blobs[id]->oop_maps()->print();
277 }
278 }
279 }
280 #endif
281 BarrierSetC1* bs = BarrierSet::barrier_set()->barrier_set_c1();
282 bs->generate_c1_runtime_stubs(blob);
283 }
284
285 CodeBlob* Runtime1::blob_for(StubID id) {
286 assert(0 <= id && id < number_of_ids, "illegal stub id");
287 return _blobs[id];
288 }
289
290
291 const char* Runtime1::name_for(StubID id) {
292 assert(0 <= id && id < number_of_ids, "illegal stub id");
293 return _blob_names[id];
294 }
295
296 const char* Runtime1::name_for_address(address entry) {
297 for (int id = 0; id < number_of_ids; id++) {
298 if (entry == entry_for((StubID)id)) return name_for((StubID)id);
299 }
300
301 #define FUNCTION_CASE(a, f) \
302 if ((intptr_t)a == CAST_FROM_FN_PTR(intptr_t, f)) return #f
303
304 FUNCTION_CASE(entry, os::javaTimeMillis);
305 FUNCTION_CASE(entry, os::javaTimeNanos);
306 FUNCTION_CASE(entry, SharedRuntime::OSR_migration_end);
307 FUNCTION_CASE(entry, SharedRuntime::d2f);
308 FUNCTION_CASE(entry, SharedRuntime::d2i);
309 FUNCTION_CASE(entry, SharedRuntime::d2l);
310 FUNCTION_CASE(entry, SharedRuntime::dcos);
311 FUNCTION_CASE(entry, SharedRuntime::dexp);
312 FUNCTION_CASE(entry, SharedRuntime::dlog);
313 FUNCTION_CASE(entry, SharedRuntime::dlog10);
314 FUNCTION_CASE(entry, SharedRuntime::dpow);
315 FUNCTION_CASE(entry, SharedRuntime::drem);
316 FUNCTION_CASE(entry, SharedRuntime::dsin);
317 FUNCTION_CASE(entry, SharedRuntime::dtan);
318 FUNCTION_CASE(entry, SharedRuntime::f2i);
319 FUNCTION_CASE(entry, SharedRuntime::f2l);
320 FUNCTION_CASE(entry, SharedRuntime::frem);
321 FUNCTION_CASE(entry, SharedRuntime::l2d);
322 FUNCTION_CASE(entry, SharedRuntime::l2f);
323 FUNCTION_CASE(entry, SharedRuntime::ldiv);
324 FUNCTION_CASE(entry, SharedRuntime::lmul);
325 FUNCTION_CASE(entry, SharedRuntime::lrem);
326 FUNCTION_CASE(entry, SharedRuntime::lrem);
327 FUNCTION_CASE(entry, SharedRuntime::dtrace_method_entry);
328 FUNCTION_CASE(entry, SharedRuntime::dtrace_method_exit);
329 FUNCTION_CASE(entry, is_instance_of);
330 FUNCTION_CASE(entry, trace_block_entry);
331 #ifdef JFR_HAVE_INTRINSICS
332 FUNCTION_CASE(entry, JfrTime::time_function());
333 #endif
334 FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32());
335 FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32C());
336 FUNCTION_CASE(entry, StubRoutines::vectorizedMismatch());
337 FUNCTION_CASE(entry, StubRoutines::dexp());
338 FUNCTION_CASE(entry, StubRoutines::dlog());
339 FUNCTION_CASE(entry, StubRoutines::dlog10());
340 FUNCTION_CASE(entry, StubRoutines::dpow());
341 FUNCTION_CASE(entry, StubRoutines::dsin());
342 FUNCTION_CASE(entry, StubRoutines::dcos());
343 FUNCTION_CASE(entry, StubRoutines::dtan());
344
345 #undef FUNCTION_CASE
346
347 // Soft float adds more runtime names.
348 return pd_name_for_address(entry);
349 }
350
351
352 JRT_ENTRY(void, Runtime1::new_instance(JavaThread* current, Klass* klass))
353 #ifndef PRODUCT
354 if (PrintC1Statistics) {
355 _new_instance_slowcase_cnt++;
356 }
357 #endif
358 assert(klass->is_klass(), "not a class");
359 Handle holder(current, klass->klass_holder()); // keep the klass alive
360 InstanceKlass* h = InstanceKlass::cast(klass);
361 h->check_valid_for_instantiation(true, CHECK);
362 // make sure klass is initialized
363 h->initialize(CHECK);
364 // allocate instance and return via TLS
365 oop obj = h->allocate_instance(CHECK);
366 current->set_vm_result(obj);
367 JRT_END
368
369
370 JRT_ENTRY(void, Runtime1::new_type_array(JavaThread* current, Klass* klass, jint length))
371 #ifndef PRODUCT
372 if (PrintC1Statistics) {
373 _new_type_array_slowcase_cnt++;
374 }
375 #endif
376 // Note: no handle for klass needed since they are not used
377 // anymore after new_typeArray() and no GC can happen before.
378 // (This may have to change if this code changes!)
379 assert(klass->is_klass(), "not a class");
380 BasicType elt_type = TypeArrayKlass::cast(klass)->element_type();
381 oop obj = oopFactory::new_typeArray(elt_type, length, CHECK);
382 current->set_vm_result(obj);
383 // This is pretty rare but this runtime patch is stressful to deoptimization
384 // if we deoptimize here so force a deopt to stress the path.
385 if (DeoptimizeALot) {
386 deopt_caller(current);
387 }
388
389 JRT_END
390
391
392 JRT_ENTRY(void, Runtime1::new_object_array(JavaThread* current, Klass* array_klass, jint length))
393 #ifndef PRODUCT
394 if (PrintC1Statistics) {
395 _new_object_array_slowcase_cnt++;
396 }
397 #endif
398 // Note: no handle for klass needed since they are not used
399 // anymore after new_objArray() and no GC can happen before.
400 // (This may have to change if this code changes!)
401 assert(array_klass->is_klass(), "not a class");
402 Handle holder(current, array_klass->klass_holder()); // keep the klass alive
403 Klass* elem_klass = ObjArrayKlass::cast(array_klass)->element_klass();
404 objArrayOop obj = oopFactory::new_objArray(elem_klass, length, CHECK);
405 current->set_vm_result(obj);
406 // This is pretty rare but this runtime patch is stressful to deoptimization
407 // if we deoptimize here so force a deopt to stress the path.
408 if (DeoptimizeALot) {
409 deopt_caller(current);
410 }
411 JRT_END
412
413
414 JRT_ENTRY(void, Runtime1::new_multi_array(JavaThread* current, Klass* klass, int rank, jint* dims))
415 #ifndef PRODUCT
416 if (PrintC1Statistics) {
417 _new_multi_array_slowcase_cnt++;
418 }
419 #endif
420 assert(klass->is_klass(), "not a class");
421 assert(rank >= 1, "rank must be nonzero");
422 Handle holder(current, klass->klass_holder()); // keep the klass alive
423 oop obj = ArrayKlass::cast(klass)->multi_allocate(rank, dims, CHECK);
424 current->set_vm_result(obj);
425 JRT_END
426
427
428 JRT_ENTRY(void, Runtime1::unimplemented_entry(JavaThread* current, StubID id))
429 tty->print_cr("Runtime1::entry_for(%d) returned unimplemented entry point", id);
430 JRT_END
431
432
433 JRT_ENTRY(void, Runtime1::throw_array_store_exception(JavaThread* current, oopDesc* obj))
434 ResourceMark rm(current);
435 const char* klass_name = obj->klass()->external_name();
436 SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayStoreException(), klass_name);
437 JRT_END
438
439
440 // counter_overflow() is called from within C1-compiled methods. The enclosing method is the method
441 // associated with the top activation record. The inlinee (that is possibly included in the enclosing
442 // method) method is passed as an argument. In order to do that it is embedded in the code as
443 // a constant.
444 static nmethod* counter_overflow_helper(JavaThread* current, int branch_bci, Method* m) {
445 nmethod* osr_nm = nullptr;
446 methodHandle method(current, m);
447
448 RegisterMap map(current,
449 RegisterMap::UpdateMap::skip,
450 RegisterMap::ProcessFrames::include,
451 RegisterMap::WalkContinuation::skip);
452 frame fr = current->last_frame().sender(&map);
453 nmethod* nm = (nmethod*) fr.cb();
454 assert(nm!= nullptr && nm->is_nmethod(), "Sanity check");
455 methodHandle enclosing_method(current, nm->method());
456
457 CompLevel level = (CompLevel)nm->comp_level();
458 int bci = InvocationEntryBci;
459 if (branch_bci != InvocationEntryBci) {
460 // Compute destination bci
461 address pc = method()->code_base() + branch_bci;
462 Bytecodes::Code branch = Bytecodes::code_at(method(), pc);
463 int offset = 0;
464 switch (branch) {
465 case Bytecodes::_if_icmplt: case Bytecodes::_iflt:
466 case Bytecodes::_if_icmpgt: case Bytecodes::_ifgt:
467 case Bytecodes::_if_icmple: case Bytecodes::_ifle:
468 case Bytecodes::_if_icmpge: case Bytecodes::_ifge:
469 case Bytecodes::_if_icmpeq: case Bytecodes::_if_acmpeq: case Bytecodes::_ifeq:
470 case Bytecodes::_if_icmpne: case Bytecodes::_if_acmpne: case Bytecodes::_ifne:
471 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull: case Bytecodes::_goto:
472 offset = (int16_t)Bytes::get_Java_u2(pc + 1);
473 break;
474 case Bytecodes::_goto_w:
475 offset = Bytes::get_Java_u4(pc + 1);
476 break;
477 default: ;
478 }
479 bci = branch_bci + offset;
480 }
481 osr_nm = CompilationPolicy::event(enclosing_method, method, branch_bci, bci, level, nm, current);
482 return osr_nm;
483 }
484
485 JRT_BLOCK_ENTRY(address, Runtime1::counter_overflow(JavaThread* current, int bci, Method* method))
486 nmethod* osr_nm;
487 JRT_BLOCK
488 osr_nm = counter_overflow_helper(current, bci, method);
489 if (osr_nm != nullptr) {
490 RegisterMap map(current,
491 RegisterMap::UpdateMap::skip,
492 RegisterMap::ProcessFrames::include,
493 RegisterMap::WalkContinuation::skip);
494 frame fr = current->last_frame().sender(&map);
495 Deoptimization::deoptimize_frame(current, fr.id());
496 }
497 JRT_BLOCK_END
498 return nullptr;
499 JRT_END
500
501 extern void vm_exit(int code);
502
503 // Enter this method from compiled code handler below. This is where we transition
504 // to VM mode. This is done as a helper routine so that the method called directly
505 // from compiled code does not have to transition to VM. This allows the entry
506 // method to see if the nmethod that we have just looked up a handler for has
507 // been deoptimized while we were in the vm. This simplifies the assembly code
508 // cpu directories.
509 //
510 // We are entering here from exception stub (via the entry method below)
511 // If there is a compiled exception handler in this method, we will continue there;
512 // otherwise we will unwind the stack and continue at the caller of top frame method
513 // Note: we enter in Java using a special JRT wrapper. This wrapper allows us to
514 // control the area where we can allow a safepoint. After we exit the safepoint area we can
515 // check to see if the handler we are going to return is now in a nmethod that has
516 // been deoptimized. If that is the case we return the deopt blob
517 // unpack_with_exception entry instead. This makes life for the exception blob easier
518 // because making that same check and diverting is painful from assembly language.
519 JRT_ENTRY_NO_ASYNC(static address, exception_handler_for_pc_helper(JavaThread* current, oopDesc* ex, address pc, nmethod*& nm))
520 // Reset method handle flag.
521 current->set_is_method_handle_return(false);
522
523 Handle exception(current, ex);
524
525 // This function is called when we are about to throw an exception. Therefore,
526 // we have to poll the stack watermark barrier to make sure that not yet safe
527 // stack frames are made safe before returning into them.
528 if (current->last_frame().cb() == Runtime1::blob_for(Runtime1::handle_exception_from_callee_id)) {
529 // The Runtime1::handle_exception_from_callee_id handler is invoked after the
530 // frame has been unwound. It instead builds its own stub frame, to call the
531 // runtime. But the throwing frame has already been unwound here.
532 StackWatermarkSet::after_unwind(current);
533 }
534
535 nm = CodeCache::find_nmethod(pc);
536 assert(nm != nullptr, "this is not an nmethod");
537 // Adjust the pc as needed/
538 if (nm->is_deopt_pc(pc)) {
539 RegisterMap map(current,
540 RegisterMap::UpdateMap::skip,
541 RegisterMap::ProcessFrames::include,
542 RegisterMap::WalkContinuation::skip);
543 frame exception_frame = current->last_frame().sender(&map);
544 // if the frame isn't deopted then pc must not correspond to the caller of last_frame
545 assert(exception_frame.is_deoptimized_frame(), "must be deopted");
546 pc = exception_frame.pc();
547 }
548 assert(exception.not_null(), "null exceptions should be handled by throw_exception");
549 // Check that exception is a subclass of Throwable
550 assert(exception->is_a(vmClasses::Throwable_klass()),
551 "Exception not subclass of Throwable");
552
553 // debugging support
554 // tracing
555 if (log_is_enabled(Info, exceptions)) {
556 ResourceMark rm; // print_value_string
557 stringStream tempst;
558 assert(nm->method() != nullptr, "Unexpected null method()");
559 tempst.print("C1 compiled method <%s>\n"
560 " at PC" INTPTR_FORMAT " for thread " INTPTR_FORMAT,
561 nm->method()->print_value_string(), p2i(pc), p2i(current));
562 Exceptions::log_exception(exception, tempst.freeze());
563 }
564 // for AbortVMOnException flag
565 Exceptions::debug_check_abort(exception);
566
567 // Check the stack guard pages and re-enable them if necessary and there is
568 // enough space on the stack to do so. Use fast exceptions only if the guard
569 // pages are enabled.
570 bool guard_pages_enabled = current->stack_overflow_state()->reguard_stack_if_needed();
571
572 if (JvmtiExport::can_post_on_exceptions()) {
573 // To ensure correct notification of exception catches and throws
574 // we have to deoptimize here. If we attempted to notify the
575 // catches and throws during this exception lookup it's possible
576 // we could deoptimize on the way out of the VM and end back in
577 // the interpreter at the throw site. This would result in double
578 // notifications since the interpreter would also notify about
579 // these same catches and throws as it unwound the frame.
580
581 RegisterMap reg_map(current,
582 RegisterMap::UpdateMap::include,
583 RegisterMap::ProcessFrames::include,
584 RegisterMap::WalkContinuation::skip);
585 frame stub_frame = current->last_frame();
586 frame caller_frame = stub_frame.sender(®_map);
587
588 // We don't really want to deoptimize the nmethod itself since we
589 // can actually continue in the exception handler ourselves but I
590 // don't see an easy way to have the desired effect.
591 Deoptimization::deoptimize_frame(current, caller_frame.id());
592 assert(caller_is_deopted(current), "Must be deoptimized");
593
594 return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
595 }
596
597 // ExceptionCache is used only for exceptions at call sites and not for implicit exceptions
598 if (guard_pages_enabled) {
599 address fast_continuation = nm->handler_for_exception_and_pc(exception, pc);
600 if (fast_continuation != nullptr) {
601 // Set flag if return address is a method handle call site.
602 current->set_is_method_handle_return(nm->is_method_handle_return(pc));
603 return fast_continuation;
604 }
605 }
606
607 // If the stack guard pages are enabled, check whether there is a handler in
608 // the current method. Otherwise (guard pages disabled), force an unwind and
609 // skip the exception cache update (i.e., just leave continuation as null).
610 address continuation = nullptr;
611 if (guard_pages_enabled) {
612
613 // New exception handling mechanism can support inlined methods
614 // with exception handlers since the mappings are from PC to PC
615
616 // Clear out the exception oop and pc since looking up an
617 // exception handler can cause class loading, which might throw an
618 // exception and those fields are expected to be clear during
619 // normal bytecode execution.
620 current->clear_exception_oop_and_pc();
621
622 bool recursive_exception = false;
623 continuation = SharedRuntime::compute_compiled_exc_handler(nm, pc, exception, false, false, recursive_exception);
624 // If an exception was thrown during exception dispatch, the exception oop may have changed
625 current->set_exception_oop(exception());
626 current->set_exception_pc(pc);
627
628 // the exception cache is used only by non-implicit exceptions
629 // Update the exception cache only when there didn't happen
630 // another exception during the computation of the compiled
631 // exception handler. Checking for exception oop equality is not
632 // sufficient because some exceptions are pre-allocated and reused.
633 if (continuation != nullptr && !recursive_exception) {
634 nm->add_handler_for_exception_and_pc(exception, pc, continuation);
635 }
636 }
637
638 current->set_vm_result(exception());
639 // Set flag if return address is a method handle call site.
640 current->set_is_method_handle_return(nm->is_method_handle_return(pc));
641
642 if (log_is_enabled(Info, exceptions)) {
643 ResourceMark rm;
644 log_info(exceptions)("Thread " PTR_FORMAT " continuing at PC " PTR_FORMAT
645 " for exception thrown at PC " PTR_FORMAT,
646 p2i(current), p2i(continuation), p2i(pc));
647 }
648
649 return continuation;
650 JRT_END
651
652 // Enter this method from compiled code only if there is a Java exception handler
653 // in the method handling the exception.
654 // We are entering here from exception stub. We don't do a normal VM transition here.
655 // We do it in a helper. This is so we can check to see if the nmethod we have just
656 // searched for an exception handler has been deoptimized in the meantime.
657 address Runtime1::exception_handler_for_pc(JavaThread* current) {
658 oop exception = current->exception_oop();
659 address pc = current->exception_pc();
660 // Still in Java mode
661 DEBUG_ONLY(NoHandleMark nhm);
662 nmethod* nm = nullptr;
663 address continuation = nullptr;
664 {
665 // Enter VM mode by calling the helper
666 ResetNoHandleMark rnhm;
667 continuation = exception_handler_for_pc_helper(current, exception, pc, nm);
668 }
669 // Back in JAVA, use no oops DON'T safepoint
670
671 // Now check to see if the nmethod we were called from is now deoptimized.
672 // If so we must return to the deopt blob and deoptimize the nmethod
673 if (nm != nullptr && caller_is_deopted(current)) {
674 continuation = SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
675 }
676
677 assert(continuation != nullptr, "no handler found");
678 return continuation;
679 }
680
681
682 JRT_ENTRY(void, Runtime1::throw_range_check_exception(JavaThread* current, int index, arrayOopDesc* a))
683 #ifndef PRODUCT
684 if (PrintC1Statistics) {
685 _throw_range_check_exception_count++;
686 }
687 #endif
688 const int len = 35;
689 assert(len < strlen("Index %d out of bounds for length %d"), "Must allocate more space for message.");
690 char message[2 * jintAsStringSize + len];
691 os::snprintf_checked(message, sizeof(message), "Index %d out of bounds for length %d", index, a->length());
692 SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), message);
693 JRT_END
694
695
696 JRT_ENTRY(void, Runtime1::throw_index_exception(JavaThread* current, int index))
697 #ifndef PRODUCT
698 if (PrintC1Statistics) {
699 _throw_index_exception_count++;
700 }
701 #endif
702 char message[16];
703 os::snprintf_checked(message, sizeof(message), "%d", index);
704 SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IndexOutOfBoundsException(), message);
705 JRT_END
706
707
708 JRT_ENTRY(void, Runtime1::throw_div0_exception(JavaThread* current))
709 #ifndef PRODUCT
710 if (PrintC1Statistics) {
711 _throw_div0_exception_count++;
712 }
713 #endif
714 SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArithmeticException(), "/ by zero");
715 JRT_END
716
717
718 JRT_ENTRY(void, Runtime1::throw_null_pointer_exception(JavaThread* current))
719 #ifndef PRODUCT
720 if (PrintC1Statistics) {
721 _throw_null_pointer_exception_count++;
722 }
723 #endif
724 SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_NullPointerException());
725 JRT_END
726
727
728 JRT_ENTRY(void, Runtime1::throw_class_cast_exception(JavaThread* current, oopDesc* object))
729 #ifndef PRODUCT
730 if (PrintC1Statistics) {
731 _throw_class_cast_exception_count++;
732 }
733 #endif
734 ResourceMark rm(current);
735 char* message = SharedRuntime::generate_class_cast_message(current, object->klass());
736 SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ClassCastException(), message);
737 JRT_END
738
739
740 JRT_ENTRY(void, Runtime1::throw_incompatible_class_change_error(JavaThread* current))
741 #ifndef PRODUCT
742 if (PrintC1Statistics) {
743 _throw_incompatible_class_change_error_count++;
744 }
745 #endif
746 ResourceMark rm(current);
747 SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IncompatibleClassChangeError());
748 JRT_END
749
750
751 JRT_BLOCK_ENTRY(void, Runtime1::monitorenter(JavaThread* current, oopDesc* obj, BasicObjectLock* lock))
752 #ifndef PRODUCT
753 if (PrintC1Statistics) {
754 _monitorenter_slowcase_cnt++;
755 }
756 #endif
757 if (LockingMode == LM_MONITOR) {
758 lock->set_obj(obj);
759 }
760 assert(LockingMode == LM_LIGHTWEIGHT || obj == lock->obj(), "must match");
761 SharedRuntime::monitor_enter_helper(obj, LockingMode == LM_LIGHTWEIGHT ? nullptr : lock->lock(), current);
762 JRT_END
763
764
765 JRT_LEAF(void, Runtime1::monitorexit(JavaThread* current, BasicObjectLock* lock))
766 assert(current == JavaThread::current(), "pre-condition");
767 #ifndef PRODUCT
768 if (PrintC1Statistics) {
769 _monitorexit_slowcase_cnt++;
770 }
771 #endif
772 assert(current->last_Java_sp(), "last_Java_sp must be set");
773 oop obj = lock->obj();
774 assert(oopDesc::is_oop(obj), "must be null or an object");
775 SharedRuntime::monitor_exit_helper(obj, lock->lock(), current);
776 JRT_END
777
778 // Cf. OptoRuntime::deoptimize_caller_frame
779 JRT_ENTRY(void, Runtime1::deoptimize(JavaThread* current, jint trap_request))
780 // Called from within the owner thread, so no need for safepoint
781 RegisterMap reg_map(current,
782 RegisterMap::UpdateMap::skip,
783 RegisterMap::ProcessFrames::include,
784 RegisterMap::WalkContinuation::skip);
785 frame stub_frame = current->last_frame();
786 assert(stub_frame.is_runtime_frame(), "Sanity check");
787 frame caller_frame = stub_frame.sender(®_map);
788 nmethod* nm = caller_frame.cb()->as_nmethod_or_null();
789 assert(nm != nullptr, "Sanity check");
790 methodHandle method(current, nm->method());
791 assert(nm == CodeCache::find_nmethod(caller_frame.pc()), "Should be the same");
792 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
793 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
794
795 if (action == Deoptimization::Action_make_not_entrant) {
796 if (nm->make_not_entrant()) {
797 if (reason == Deoptimization::Reason_tenured) {
798 MethodData* trap_mdo = Deoptimization::get_method_data(current, method, true /*create_if_missing*/);
799 if (trap_mdo != nullptr) {
800 trap_mdo->inc_tenure_traps();
801 }
802 }
803 }
804 }
805
806 // Deoptimize the caller frame.
807 Deoptimization::deoptimize_frame(current, caller_frame.id());
808 // Return to the now deoptimized frame.
809 JRT_END
810
811
812 #ifndef DEOPTIMIZE_WHEN_PATCHING
813
814 static Klass* resolve_field_return_klass(const methodHandle& caller, int bci, TRAPS) {
815 Bytecode_field field_access(caller, bci);
816 // This can be static or non-static field access
817 Bytecodes::Code code = field_access.code();
818
819 // We must load class, initialize class and resolve the field
820 fieldDescriptor result; // initialize class if needed
821 constantPoolHandle constants(THREAD, caller->constants());
822 LinkResolver::resolve_field_access(result, constants, field_access.index(), caller, Bytecodes::java_code(code), CHECK_NULL);
823 return result.field_holder();
824 }
825
826
827 //
828 // This routine patches sites where a class wasn't loaded or
829 // initialized at the time the code was generated. It handles
830 // references to classes, fields and forcing of initialization. Most
831 // of the cases are straightforward and involving simply forcing
832 // resolution of a class, rewriting the instruction stream with the
833 // needed constant and replacing the call in this function with the
834 // patched code. The case for static field is more complicated since
835 // the thread which is in the process of initializing a class can
836 // access it's static fields but other threads can't so the code
837 // either has to deoptimize when this case is detected or execute a
838 // check that the current thread is the initializing thread. The
839 // current
840 //
841 // Patches basically look like this:
842 //
843 //
844 // patch_site: jmp patch stub ;; will be patched
845 // continue: ...
846 // ...
847 // ...
848 // ...
849 //
850 // They have a stub which looks like this:
851 //
852 // ;; patch body
853 // movl <const>, reg (for class constants)
854 // <or> movl [reg1 + <const>], reg (for field offsets)
855 // <or> movl reg, [reg1 + <const>] (for field offsets)
856 // <being_init offset> <bytes to copy> <bytes to skip>
857 // patch_stub: call Runtime1::patch_code (through a runtime stub)
858 // jmp patch_site
859 //
860 //
861 // A normal patch is done by rewriting the patch body, usually a move,
862 // and then copying it into place over top of the jmp instruction
863 // being careful to flush caches and doing it in an MP-safe way. The
864 // constants following the patch body are used to find various pieces
865 // of the patch relative to the call site for Runtime1::patch_code.
866 // The case for getstatic and putstatic is more complicated because
867 // getstatic and putstatic have special semantics when executing while
868 // the class is being initialized. getstatic/putstatic on a class
869 // which is being_initialized may be executed by the initializing
870 // thread but other threads have to block when they execute it. This
871 // is accomplished in compiled code by executing a test of the current
872 // thread against the initializing thread of the class. It's emitted
873 // as boilerplate in their stub which allows the patched code to be
874 // executed before it's copied back into the main body of the nmethod.
875 //
876 // being_init: get_thread(<tmp reg>
877 // cmpl [reg1 + <init_thread_offset>], <tmp reg>
878 // jne patch_stub
879 // movl [reg1 + <const>], reg (for field offsets) <or>
880 // movl reg, [reg1 + <const>] (for field offsets)
881 // jmp continue
882 // <being_init offset> <bytes to copy> <bytes to skip>
883 // patch_stub: jmp Runtim1::patch_code (through a runtime stub)
884 // jmp patch_site
885 //
886 // If the class is being initialized the patch body is rewritten and
887 // the patch site is rewritten to jump to being_init, instead of
888 // patch_stub. Whenever this code is executed it checks the current
889 // thread against the initializing thread so other threads will enter
890 // the runtime and end up blocked waiting the class to finish
891 // initializing inside the calls to resolve_field below. The
892 // initializing class will continue on it's way. Once the class is
893 // fully_initialized, the intializing_thread of the class becomes
894 // null, so the next thread to execute this code will fail the test,
895 // call into patch_code and complete the patching process by copying
896 // the patch body back into the main part of the nmethod and resume
897 // executing.
898
899 // NB:
900 //
901 // Patchable instruction sequences inherently exhibit race conditions,
902 // where thread A is patching an instruction at the same time thread B
903 // is executing it. The algorithms we use ensure that any observation
904 // that B can make on any intermediate states during A's patching will
905 // always end up with a correct outcome. This is easiest if there are
906 // few or no intermediate states. (Some inline caches have two
907 // related instructions that must be patched in tandem. For those,
908 // intermediate states seem to be unavoidable, but we will get the
909 // right answer from all possible observation orders.)
910 //
911 // When patching the entry instruction at the head of a method, or a
912 // linkable call instruction inside of a method, we try very hard to
913 // use a patch sequence which executes as a single memory transaction.
914 // This means, in practice, that when thread A patches an instruction,
915 // it should patch a 32-bit or 64-bit word that somehow overlaps the
916 // instruction or is contained in it. We believe that memory hardware
917 // will never break up such a word write, if it is naturally aligned
918 // for the word being written. We also know that some CPUs work very
919 // hard to create atomic updates even of naturally unaligned words,
920 // but we don't want to bet the farm on this always working.
921 //
922 // Therefore, if there is any chance of a race condition, we try to
923 // patch only naturally aligned words, as single, full-word writes.
924
925 JRT_ENTRY(void, Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id ))
926 #ifndef PRODUCT
927 if (PrintC1Statistics) {
928 _patch_code_slowcase_cnt++;
929 }
930 #endif
931
932 ResourceMark rm(current);
933 RegisterMap reg_map(current,
934 RegisterMap::UpdateMap::skip,
935 RegisterMap::ProcessFrames::include,
936 RegisterMap::WalkContinuation::skip);
937 frame runtime_frame = current->last_frame();
938 frame caller_frame = runtime_frame.sender(®_map);
939
940 // last java frame on stack
941 vframeStream vfst(current, true);
942 assert(!vfst.at_end(), "Java frame must exist");
943
944 methodHandle caller_method(current, vfst.method());
945 // Note that caller_method->code() may not be same as caller_code because of OSR's
946 // Note also that in the presence of inlining it is not guaranteed
947 // that caller_method() == caller_code->method()
948
949 int bci = vfst.bci();
950 Bytecodes::Code code = caller_method()->java_code_at(bci);
951
952 // this is used by assertions in the access_field_patching_id
953 BasicType patch_field_type = T_ILLEGAL;
954 bool deoptimize_for_volatile = false;
955 bool deoptimize_for_atomic = false;
956 int patch_field_offset = -1;
957 Klass* init_klass = nullptr; // klass needed by load_klass_patching code
958 Klass* load_klass = nullptr; // klass needed by load_klass_patching code
959 Handle mirror(current, nullptr); // oop needed by load_mirror_patching code
960 Handle appendix(current, nullptr); // oop needed by appendix_patching code
961 bool load_klass_or_mirror_patch_id =
962 (stub_id == Runtime1::load_klass_patching_id || stub_id == Runtime1::load_mirror_patching_id);
963
964 if (stub_id == Runtime1::access_field_patching_id) {
965
966 Bytecode_field field_access(caller_method, bci);
967 fieldDescriptor result; // initialize class if needed
968 Bytecodes::Code code = field_access.code();
969 constantPoolHandle constants(current, caller_method->constants());
970 LinkResolver::resolve_field_access(result, constants, field_access.index(), caller_method, Bytecodes::java_code(code), CHECK);
971 patch_field_offset = result.offset();
972
973 // If we're patching a field which is volatile then at compile it
974 // must not have been know to be volatile, so the generated code
975 // isn't correct for a volatile reference. The nmethod has to be
976 // deoptimized so that the code can be regenerated correctly.
977 // This check is only needed for access_field_patching since this
978 // is the path for patching field offsets. load_klass is only
979 // used for patching references to oops which don't need special
980 // handling in the volatile case.
981
982 deoptimize_for_volatile = result.access_flags().is_volatile();
983
984 // If we are patching a field which should be atomic, then
985 // the generated code is not correct either, force deoptimizing.
986 // We need to only cover T_LONG and T_DOUBLE fields, as we can
987 // break access atomicity only for them.
988
989 // Strictly speaking, the deoptimization on 64-bit platforms
990 // is unnecessary, and T_LONG stores on 32-bit platforms need
991 // to be handled by special patching code when AlwaysAtomicAccesses
992 // becomes product feature. At this point, we are still going
993 // for the deoptimization for consistency against volatile
994 // accesses.
995
996 patch_field_type = result.field_type();
997 deoptimize_for_atomic = (AlwaysAtomicAccesses && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG));
998
999 } else if (load_klass_or_mirror_patch_id) {
1000 Klass* k = nullptr;
1001 switch (code) {
1002 case Bytecodes::_putstatic:
1003 case Bytecodes::_getstatic:
1004 { Klass* klass = resolve_field_return_klass(caller_method, bci, CHECK);
1005 init_klass = klass;
1006 mirror = Handle(current, klass->java_mirror());
1007 }
1008 break;
1009 case Bytecodes::_new:
1010 { Bytecode_new bnew(caller_method(), caller_method->bcp_from(bci));
1011 k = caller_method->constants()->klass_at(bnew.index(), CHECK);
1012 }
1013 break;
1014 case Bytecodes::_multianewarray:
1015 { Bytecode_multianewarray mna(caller_method(), caller_method->bcp_from(bci));
1016 k = caller_method->constants()->klass_at(mna.index(), CHECK);
1017 }
1018 break;
1019 case Bytecodes::_instanceof:
1020 { Bytecode_instanceof io(caller_method(), caller_method->bcp_from(bci));
1021 k = caller_method->constants()->klass_at(io.index(), CHECK);
1022 }
1023 break;
1024 case Bytecodes::_checkcast:
1025 { Bytecode_checkcast cc(caller_method(), caller_method->bcp_from(bci));
1026 k = caller_method->constants()->klass_at(cc.index(), CHECK);
1027 }
1028 break;
1029 case Bytecodes::_anewarray:
1030 { Bytecode_anewarray anew(caller_method(), caller_method->bcp_from(bci));
1031 Klass* ek = caller_method->constants()->klass_at(anew.index(), CHECK);
1032 k = ek->array_klass(CHECK);
1033 }
1034 break;
1035 case Bytecodes::_ldc:
1036 case Bytecodes::_ldc_w:
1037 case Bytecodes::_ldc2_w:
1038 {
1039 Bytecode_loadconstant cc(caller_method, bci);
1040 oop m = cc.resolve_constant(CHECK);
1041 mirror = Handle(current, m);
1042 }
1043 break;
1044 default: fatal("unexpected bytecode for load_klass_or_mirror_patch_id");
1045 }
1046 load_klass = k;
1047 } else if (stub_id == load_appendix_patching_id) {
1048 Bytecode_invoke bytecode(caller_method, bci);
1049 Bytecodes::Code bc = bytecode.invoke_code();
1050
1051 CallInfo info;
1052 constantPoolHandle pool(current, caller_method->constants());
1053 int index = bytecode.index();
1054 LinkResolver::resolve_invoke(info, Handle(), pool, index, bc, CHECK);
1055 switch (bc) {
1056 case Bytecodes::_invokehandle: {
1057 ResolvedMethodEntry* entry = pool->cache()->set_method_handle(index, info);
1058 appendix = Handle(current, pool->cache()->appendix_if_resolved(entry));
1059 break;
1060 }
1061 case Bytecodes::_invokedynamic: {
1062 int indy_index = pool->decode_invokedynamic_index(index);
1063 appendix = Handle(current, pool->cache()->set_dynamic_call(info, indy_index));
1064 break;
1065 }
1066 default: fatal("unexpected bytecode for load_appendix_patching_id");
1067 }
1068 } else {
1069 ShouldNotReachHere();
1070 }
1071
1072 if (deoptimize_for_volatile || deoptimize_for_atomic) {
1073 // At compile time we assumed the field wasn't volatile/atomic but after
1074 // loading it turns out it was volatile/atomic so we have to throw the
1075 // compiled code out and let it be regenerated.
1076 if (TracePatching) {
1077 if (deoptimize_for_volatile) {
1078 tty->print_cr("Deoptimizing for patching volatile field reference");
1079 }
1080 if (deoptimize_for_atomic) {
1081 tty->print_cr("Deoptimizing for patching atomic field reference");
1082 }
1083 }
1084
1085 // It's possible the nmethod was invalidated in the last
1086 // safepoint, but if it's still alive then make it not_entrant.
1087 nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1088 if (nm != nullptr) {
1089 nm->make_not_entrant();
1090 }
1091
1092 Deoptimization::deoptimize_frame(current, caller_frame.id());
1093
1094 // Return to the now deoptimized frame.
1095 }
1096
1097 // Now copy code back
1098
1099 {
1100 MutexLocker ml_patch (current, Patching_lock, Mutex::_no_safepoint_check_flag);
1101 //
1102 // Deoptimization may have happened while we waited for the lock.
1103 // In that case we don't bother to do any patching we just return
1104 // and let the deopt happen
1105 if (!caller_is_deopted(current)) {
1106 NativeGeneralJump* jump = nativeGeneralJump_at(caller_frame.pc());
1107 address instr_pc = jump->jump_destination();
1108 NativeInstruction* ni = nativeInstruction_at(instr_pc);
1109 if (ni->is_jump() ) {
1110 // the jump has not been patched yet
1111 // The jump destination is slow case and therefore not part of the stubs
1112 // (stubs are only for StaticCalls)
1113
1114 // format of buffer
1115 // ....
1116 // instr byte 0 <-- copy_buff
1117 // instr byte 1
1118 // ..
1119 // instr byte n-1
1120 // n
1121 // .... <-- call destination
1122
1123 address stub_location = caller_frame.pc() + PatchingStub::patch_info_offset();
1124 unsigned char* byte_count = (unsigned char*) (stub_location - 1);
1125 unsigned char* byte_skip = (unsigned char*) (stub_location - 2);
1126 unsigned char* being_initialized_entry_offset = (unsigned char*) (stub_location - 3);
1127 address copy_buff = stub_location - *byte_skip - *byte_count;
1128 address being_initialized_entry = stub_location - *being_initialized_entry_offset;
1129 if (TracePatching) {
1130 ttyLocker ttyl;
1131 tty->print_cr(" Patching %s at bci %d at address " INTPTR_FORMAT " (%s)", Bytecodes::name(code), bci,
1132 p2i(instr_pc), (stub_id == Runtime1::access_field_patching_id) ? "field" : "klass");
1133 nmethod* caller_code = CodeCache::find_nmethod(caller_frame.pc());
1134 assert(caller_code != nullptr, "nmethod not found");
1135
1136 // NOTE we use pc() not original_pc() because we already know they are
1137 // identical otherwise we'd have never entered this block of code
1138
1139 const ImmutableOopMap* map = caller_code->oop_map_for_return_address(caller_frame.pc());
1140 assert(map != nullptr, "null check");
1141 map->print();
1142 tty->cr();
1143
1144 Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1145 }
1146 // depending on the code below, do_patch says whether to copy the patch body back into the nmethod
1147 bool do_patch = true;
1148 if (stub_id == Runtime1::access_field_patching_id) {
1149 // The offset may not be correct if the class was not loaded at code generation time.
1150 // Set it now.
1151 NativeMovRegMem* n_move = nativeMovRegMem_at(copy_buff);
1152 assert(n_move->offset() == 0 || (n_move->offset() == 4 && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG)), "illegal offset for type");
1153 assert(patch_field_offset >= 0, "illegal offset");
1154 n_move->add_offset_in_bytes(patch_field_offset);
1155 } else if (load_klass_or_mirror_patch_id) {
1156 // If a getstatic or putstatic is referencing a klass which
1157 // isn't fully initialized, the patch body isn't copied into
1158 // place until initialization is complete. In this case the
1159 // patch site is setup so that any threads besides the
1160 // initializing thread are forced to come into the VM and
1161 // block.
1162 do_patch = (code != Bytecodes::_getstatic && code != Bytecodes::_putstatic) ||
1163 InstanceKlass::cast(init_klass)->is_initialized();
1164 NativeGeneralJump* jump = nativeGeneralJump_at(instr_pc);
1165 if (jump->jump_destination() == being_initialized_entry) {
1166 assert(do_patch == true, "initialization must be complete at this point");
1167 } else {
1168 // patch the instruction <move reg, klass>
1169 NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1170
1171 assert(n_copy->data() == 0 ||
1172 n_copy->data() == (intptr_t)Universe::non_oop_word(),
1173 "illegal init value");
1174 if (stub_id == Runtime1::load_klass_patching_id) {
1175 assert(load_klass != nullptr, "klass not set");
1176 n_copy->set_data((intx) (load_klass));
1177 } else {
1178 // Don't need a G1 pre-barrier here since we assert above that data isn't an oop.
1179 n_copy->set_data(cast_from_oop<intx>(mirror()));
1180 }
1181
1182 if (TracePatching) {
1183 Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1184 }
1185 }
1186 } else if (stub_id == Runtime1::load_appendix_patching_id) {
1187 NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1188 assert(n_copy->data() == 0 ||
1189 n_copy->data() == (intptr_t)Universe::non_oop_word(),
1190 "illegal init value");
1191 n_copy->set_data(cast_from_oop<intx>(appendix()));
1192
1193 if (TracePatching) {
1194 Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1195 }
1196 } else {
1197 ShouldNotReachHere();
1198 }
1199
1200 if (do_patch) {
1201 // replace instructions
1202 // first replace the tail, then the call
1203 #ifdef ARM
1204 if((load_klass_or_mirror_patch_id ||
1205 stub_id == Runtime1::load_appendix_patching_id) &&
1206 nativeMovConstReg_at(copy_buff)->is_pc_relative()) {
1207 nmethod* nm = CodeCache::find_nmethod(instr_pc);
1208 address addr = nullptr;
1209 assert(nm != nullptr, "invalid nmethod_pc");
1210 RelocIterator mds(nm, copy_buff, copy_buff + 1);
1211 while (mds.next()) {
1212 if (mds.type() == relocInfo::oop_type) {
1213 assert(stub_id == Runtime1::load_mirror_patching_id ||
1214 stub_id == Runtime1::load_appendix_patching_id, "wrong stub id");
1215 oop_Relocation* r = mds.oop_reloc();
1216 addr = (address)r->oop_addr();
1217 break;
1218 } else if (mds.type() == relocInfo::metadata_type) {
1219 assert(stub_id == Runtime1::load_klass_patching_id, "wrong stub id");
1220 metadata_Relocation* r = mds.metadata_reloc();
1221 addr = (address)r->metadata_addr();
1222 break;
1223 }
1224 }
1225 assert(addr != nullptr, "metadata relocation must exist");
1226 copy_buff -= *byte_count;
1227 NativeMovConstReg* n_copy2 = nativeMovConstReg_at(copy_buff);
1228 n_copy2->set_pc_relative_offset(addr, instr_pc);
1229 }
1230 #endif
1231
1232 for (int i = NativeGeneralJump::instruction_size; i < *byte_count; i++) {
1233 address ptr = copy_buff + i;
1234 int a_byte = (*ptr) & 0xFF;
1235 address dst = instr_pc + i;
1236 *(unsigned char*)dst = (unsigned char) a_byte;
1237 }
1238 ICache::invalidate_range(instr_pc, *byte_count);
1239 NativeGeneralJump::replace_mt_safe(instr_pc, copy_buff);
1240
1241 if (load_klass_or_mirror_patch_id ||
1242 stub_id == Runtime1::load_appendix_patching_id) {
1243 relocInfo::relocType rtype =
1244 (stub_id == Runtime1::load_klass_patching_id) ?
1245 relocInfo::metadata_type :
1246 relocInfo::oop_type;
1247 // update relocInfo to metadata
1248 nmethod* nm = CodeCache::find_nmethod(instr_pc);
1249 assert(nm != nullptr, "invalid nmethod_pc");
1250
1251 // The old patch site is now a move instruction so update
1252 // the reloc info so that it will get updated during
1253 // future GCs.
1254 RelocIterator iter(nm, (address)instr_pc, (address)(instr_pc + 1));
1255 relocInfo::change_reloc_info_for_address(&iter, (address) instr_pc,
1256 relocInfo::none, rtype);
1257 }
1258
1259 } else {
1260 ICache::invalidate_range(copy_buff, *byte_count);
1261 NativeGeneralJump::insert_unconditional(instr_pc, being_initialized_entry);
1262 }
1263 }
1264 }
1265 }
1266
1267 // If we are patching in a non-perm oop, make sure the nmethod
1268 // is on the right list.
1269 {
1270 MutexLocker ml_code (current, CodeCache_lock, Mutex::_no_safepoint_check_flag);
1271 nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1272 guarantee(nm != nullptr, "only nmethods can contain non-perm oops");
1273
1274 // Since we've patched some oops in the nmethod,
1275 // (re)register it with the heap.
1276 Universe::heap()->register_nmethod(nm);
1277 }
1278 JRT_END
1279
1280 #else // DEOPTIMIZE_WHEN_PATCHING
1281
1282 static bool is_patching_needed(JavaThread* current, Runtime1::StubID stub_id) {
1283 if (stub_id == Runtime1::load_klass_patching_id ||
1284 stub_id == Runtime1::load_mirror_patching_id) {
1285 // last java frame on stack
1286 vframeStream vfst(current, true);
1287 assert(!vfst.at_end(), "Java frame must exist");
1288
1289 methodHandle caller_method(current, vfst.method());
1290 int bci = vfst.bci();
1291 Bytecodes::Code code = caller_method()->java_code_at(bci);
1292
1293 switch (code) {
1294 case Bytecodes::_new:
1295 case Bytecodes::_anewarray:
1296 case Bytecodes::_multianewarray:
1297 case Bytecodes::_instanceof:
1298 case Bytecodes::_checkcast: {
1299 Bytecode bc(caller_method(), caller_method->bcp_from(bci));
1300 constantTag tag = caller_method->constants()->tag_at(bc.get_index_u2(code));
1301 if (tag.is_unresolved_klass_in_error()) {
1302 return false; // throws resolution error
1303 }
1304 break;
1305 }
1306
1307 default: break;
1308 }
1309 }
1310 return true;
1311 }
1312
1313 void Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id) {
1314 #ifndef PRODUCT
1315 if (PrintC1Statistics) {
1316 _patch_code_slowcase_cnt++;
1317 }
1318 #endif
1319
1320 // Enable WXWrite: the function is called by c1 stub as a runtime function
1321 // (see another implementation above).
1322 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
1323
1324 if (TracePatching) {
1325 tty->print_cr("Deoptimizing because patch is needed");
1326 }
1327
1328 RegisterMap reg_map(current,
1329 RegisterMap::UpdateMap::skip,
1330 RegisterMap::ProcessFrames::include,
1331 RegisterMap::WalkContinuation::skip);
1332
1333 frame runtime_frame = current->last_frame();
1334 frame caller_frame = runtime_frame.sender(®_map);
1335 assert(caller_frame.is_compiled_frame(), "Wrong frame type");
1336
1337 if (is_patching_needed(current, stub_id)) {
1338 // Make sure the nmethod is invalidated, i.e. made not entrant.
1339 nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1340 if (nm != nullptr) {
1341 nm->make_not_entrant();
1342 }
1343 }
1344
1345 Deoptimization::deoptimize_frame(current, caller_frame.id());
1346 // Return to the now deoptimized frame.
1347 postcond(caller_is_deopted(current));
1348 }
1349
1350 #endif // DEOPTIMIZE_WHEN_PATCHING
1351
1352 // Entry point for compiled code. We want to patch a nmethod.
1353 // We don't do a normal VM transition here because we want to
1354 // know after the patching is complete and any safepoint(s) are taken
1355 // if the calling nmethod was deoptimized. We do this by calling a
1356 // helper method which does the normal VM transition and when it
1357 // completes we can check for deoptimization. This simplifies the
1358 // assembly code in the cpu directories.
1359 //
1360 int Runtime1::move_klass_patching(JavaThread* current) {
1361 //
1362 // NOTE: we are still in Java
1363 //
1364 debug_only(NoHandleMark nhm;)
1365 {
1366 // Enter VM mode
1367 ResetNoHandleMark rnhm;
1368 patch_code(current, load_klass_patching_id);
1369 }
1370 // Back in JAVA, use no oops DON'T safepoint
1371
1372 // Return true if calling code is deoptimized
1373
1374 return caller_is_deopted(current);
1375 }
1376
1377 int Runtime1::move_mirror_patching(JavaThread* current) {
1378 //
1379 // NOTE: we are still in Java
1380 //
1381 debug_only(NoHandleMark nhm;)
1382 {
1383 // Enter VM mode
1384 ResetNoHandleMark rnhm;
1385 patch_code(current, load_mirror_patching_id);
1386 }
1387 // Back in JAVA, use no oops DON'T safepoint
1388
1389 // Return true if calling code is deoptimized
1390
1391 return caller_is_deopted(current);
1392 }
1393
1394 int Runtime1::move_appendix_patching(JavaThread* current) {
1395 //
1396 // NOTE: we are still in Java
1397 //
1398 debug_only(NoHandleMark nhm;)
1399 {
1400 // Enter VM mode
1401 ResetNoHandleMark rnhm;
1402 patch_code(current, load_appendix_patching_id);
1403 }
1404 // Back in JAVA, use no oops DON'T safepoint
1405
1406 // Return true if calling code is deoptimized
1407
1408 return caller_is_deopted(current);
1409 }
1410
1411 // Entry point for compiled code. We want to patch a nmethod.
1412 // We don't do a normal VM transition here because we want to
1413 // know after the patching is complete and any safepoint(s) are taken
1414 // if the calling nmethod was deoptimized. We do this by calling a
1415 // helper method which does the normal VM transition and when it
1416 // completes we can check for deoptimization. This simplifies the
1417 // assembly code in the cpu directories.
1418 //
1419 int Runtime1::access_field_patching(JavaThread* current) {
1420 //
1421 // NOTE: we are still in Java
1422 //
1423 // Handles created in this function will be deleted by the
1424 // HandleMarkCleaner in the transition to the VM.
1425 NoHandleMark nhm;
1426 {
1427 // Enter VM mode
1428 ResetNoHandleMark rnhm;
1429 patch_code(current, access_field_patching_id);
1430 }
1431 // Back in JAVA, use no oops DON'T safepoint
1432
1433 // Return true if calling code is deoptimized
1434
1435 return caller_is_deopted(current);
1436 }
1437
1438
1439 JRT_LEAF(void, Runtime1::trace_block_entry(jint block_id))
1440 // for now we just print out the block id
1441 tty->print("%d ", block_id);
1442 JRT_END
1443
1444
1445 JRT_LEAF(int, Runtime1::is_instance_of(oopDesc* mirror, oopDesc* obj))
1446 // had to return int instead of bool, otherwise there may be a mismatch
1447 // between the C calling convention and the Java one.
1448 // e.g., on x86, GCC may clear only %al when returning a bool false, but
1449 // JVM takes the whole %eax as the return value, which may misinterpret
1450 // the return value as a boolean true.
1451
1452 assert(mirror != nullptr, "should null-check on mirror before calling");
1453 Klass* k = java_lang_Class::as_Klass(mirror);
1454 return (k != nullptr && obj != nullptr && obj->is_a(k)) ? 1 : 0;
1455 JRT_END
1456
1457 JRT_ENTRY(void, Runtime1::predicate_failed_trap(JavaThread* current))
1458 ResourceMark rm;
1459
1460 RegisterMap reg_map(current,
1461 RegisterMap::UpdateMap::skip,
1462 RegisterMap::ProcessFrames::include,
1463 RegisterMap::WalkContinuation::skip);
1464 frame runtime_frame = current->last_frame();
1465 frame caller_frame = runtime_frame.sender(®_map);
1466
1467 nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1468 assert (nm != nullptr, "no more nmethod?");
1469 nm->make_not_entrant();
1470
1471 methodHandle m(current, nm->method());
1472 MethodData* mdo = m->method_data();
1473
1474 if (mdo == nullptr && !HAS_PENDING_EXCEPTION) {
1475 // Build an MDO. Ignore errors like OutOfMemory;
1476 // that simply means we won't have an MDO to update.
1477 Method::build_profiling_method_data(m, THREAD);
1478 if (HAS_PENDING_EXCEPTION) {
1479 // Only metaspace OOM is expected. No Java code executed.
1480 assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1481 CLEAR_PENDING_EXCEPTION;
1482 }
1483 mdo = m->method_data();
1484 }
1485
1486 if (mdo != nullptr) {
1487 mdo->inc_trap_count(Deoptimization::Reason_none);
1488 }
1489
1490 if (TracePredicateFailedTraps) {
1491 stringStream ss1, ss2;
1492 vframeStream vfst(current);
1493 Method* inlinee = vfst.method();
1494 inlinee->print_short_name(&ss1);
1495 m->print_short_name(&ss2);
1496 tty->print_cr("Predicate failed trap in method %s at bci %d inlined in %s at pc " INTPTR_FORMAT, ss1.freeze(), vfst.bci(), ss2.freeze(), p2i(caller_frame.pc()));
1497 }
1498
1499
1500 Deoptimization::deoptimize_frame(current, caller_frame.id());
1501
1502 JRT_END
1503
1504 // Check exception if AbortVMOnException flag set
1505 JRT_LEAF(void, Runtime1::check_abort_on_vm_exception(oopDesc* ex))
1506 ResourceMark rm;
1507 const char* message = nullptr;
1508 if (ex->is_a(vmClasses::Throwable_klass())) {
1509 oop msg = java_lang_Throwable::message(ex);
1510 if (msg != nullptr) {
1511 message = java_lang_String::as_utf8_string(msg);
1512 }
1513 }
1514 Exceptions::debug_check_abort(ex->klass()->external_name(), message);
1515 JRT_END
1516
1517 #ifndef PRODUCT
1518 void Runtime1::print_statistics() {
1519 tty->print_cr("C1 Runtime statistics:");
1520 tty->print_cr(" _resolve_invoke_virtual_cnt: %u", SharedRuntime::_resolve_virtual_ctr);
1521 tty->print_cr(" _resolve_invoke_opt_virtual_cnt: %u", SharedRuntime::_resolve_opt_virtual_ctr);
1522 tty->print_cr(" _resolve_invoke_static_cnt: %u", SharedRuntime::_resolve_static_ctr);
1523 tty->print_cr(" _handle_wrong_method_cnt: %u", SharedRuntime::_wrong_method_ctr);
1524 tty->print_cr(" _ic_miss_cnt: %u", SharedRuntime::_ic_miss_ctr);
1525 tty->print_cr(" _generic_arraycopystub_cnt: %u", _generic_arraycopystub_cnt);
1526 tty->print_cr(" _byte_arraycopy_cnt: %u", _byte_arraycopy_stub_cnt);
1527 tty->print_cr(" _short_arraycopy_cnt: %u", _short_arraycopy_stub_cnt);
1528 tty->print_cr(" _int_arraycopy_cnt: %u", _int_arraycopy_stub_cnt);
1529 tty->print_cr(" _long_arraycopy_cnt: %u", _long_arraycopy_stub_cnt);
1530 tty->print_cr(" _oop_arraycopy_cnt: %u", _oop_arraycopy_stub_cnt);
1531 tty->print_cr(" _arraycopy_slowcase_cnt: %u", _arraycopy_slowcase_cnt);
1532 tty->print_cr(" _arraycopy_checkcast_cnt: %u", _arraycopy_checkcast_cnt);
1533 tty->print_cr(" _arraycopy_checkcast_attempt_cnt:%u", _arraycopy_checkcast_attempt_cnt);
1534
1535 tty->print_cr(" _new_type_array_slowcase_cnt: %u", _new_type_array_slowcase_cnt);
1536 tty->print_cr(" _new_object_array_slowcase_cnt: %u", _new_object_array_slowcase_cnt);
1537 tty->print_cr(" _new_instance_slowcase_cnt: %u", _new_instance_slowcase_cnt);
1538 tty->print_cr(" _new_multi_array_slowcase_cnt: %u", _new_multi_array_slowcase_cnt);
1539 tty->print_cr(" _monitorenter_slowcase_cnt: %u", _monitorenter_slowcase_cnt);
1540 tty->print_cr(" _monitorexit_slowcase_cnt: %u", _monitorexit_slowcase_cnt);
1541 tty->print_cr(" _patch_code_slowcase_cnt: %u", _patch_code_slowcase_cnt);
1542
1543 tty->print_cr(" _throw_range_check_exception_count: %u:", _throw_range_check_exception_count);
1544 tty->print_cr(" _throw_index_exception_count: %u:", _throw_index_exception_count);
1545 tty->print_cr(" _throw_div0_exception_count: %u:", _throw_div0_exception_count);
1546 tty->print_cr(" _throw_null_pointer_exception_count: %u:", _throw_null_pointer_exception_count);
1547 tty->print_cr(" _throw_class_cast_exception_count: %u:", _throw_class_cast_exception_count);
1548 tty->print_cr(" _throw_incompatible_class_change_error_count: %u:", _throw_incompatible_class_change_error_count);
1549 tty->print_cr(" _throw_count: %u:", _throw_count);
1550
1551 SharedRuntime::print_ic_miss_histogram();
1552 tty->cr();
1553 }
1554 #endif // PRODUCT