1 /*
2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016, 2017, SAP SE. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "jvm.h"
28 #include "asm/macroAssembler.inline.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "interpreter/interpreter.hpp"
31 #include "memory/allocation.inline.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "prims/methodHandles.hpp"
34 #include "runtime/frame.inline.hpp"
35 #include "utilities/preserveException.hpp"
36
37 #ifdef PRODUCT
38 #define __ _masm->
39 #define BLOCK_COMMENT(str) /* nothing */
40 #else
41 #define __ (Verbose ? (_masm->block_comment(FILE_AND_LINE),_masm):_masm)->
42 #define BLOCK_COMMENT(str) __ block_comment(str)
43 #endif
44
45 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
46
47 // Workaround for C++ overloading nastiness on '0' for RegisterOrConstant.
48 static RegisterOrConstant constant(int value) {
49 return RegisterOrConstant(value);
50 }
51
52 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg,
53 Register temp_reg, Register temp2_reg) {
54 if (VerifyMethodHandles) {
55 verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class),
56 temp_reg, temp2_reg, "MH argument is a Class");
57 }
58 __ z_lg(klass_reg, Address(klass_reg, java_lang_Class::klass_offset_in_bytes()));
59 }
60
61
62 #ifdef ASSERT
63 static int check_nonzero(const char* xname, int x) {
64 assert(x != 0, "%s should be nonzero", xname);
65 return x;
66 }
67 #define NONZERO(x) check_nonzero(#x, x)
68 #else
69 #define NONZERO(x) (x)
70 #endif
71
72 #ifdef ASSERT
73 void MethodHandles::verify_klass(MacroAssembler* _masm,
74 Register obj_reg, SystemDictionary::WKID klass_id,
75 Register temp_reg, Register temp2_reg,
76 const char* error_message) {
77
78 InstanceKlass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
79 Klass* klass = SystemDictionary::well_known_klass(klass_id);
80
81 assert(temp_reg != Z_R0 && // Is used as base register!
82 temp_reg != noreg && temp2_reg != noreg, "need valid registers!");
83
84 NearLabel L_ok, L_bad;
85
86 BLOCK_COMMENT("verify_klass {");
87
88 __ verify_oop(obj_reg);
89 __ compareU64_and_branch(obj_reg, (intptr_t)0L, Assembler::bcondEqual, L_bad);
90 __ load_klass(temp_reg, obj_reg);
91 // klass_addr is a klass in allstatic SystemDictionaryHandles. Can't get GCed.
92 __ load_const_optimized(temp2_reg, (address)klass_addr);
93 __ z_lg(temp2_reg, Address(temp2_reg));
94 __ compareU64_and_branch(temp_reg, temp2_reg, Assembler::bcondEqual, L_ok);
95
96 intptr_t super_check_offset = klass->super_check_offset();
97 __ z_lg(temp_reg, Address(temp_reg, super_check_offset));
98 __ compareU64_and_branch(temp_reg, temp2_reg, Assembler::bcondEqual, L_ok);
99 __ BIND(L_bad);
100 __ stop(error_message);
101 __ BIND(L_ok);
102
103 BLOCK_COMMENT("} verify_klass");
104 }
105
106 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind,
107 Register member_reg, Register temp ) {
108 NearLabel L;
109 BLOCK_COMMENT("verify_ref_kind {");
110
111 __ z_llgf(temp,
112 Address(member_reg,
113 NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes())));
114 __ z_srl(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
115 __ z_nilf(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
116 __ compare32_and_branch(temp, constant(ref_kind), Assembler::bcondEqual, L);
117
118 {
119 char *buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
120
121 jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
122 if (ref_kind == JVM_REF_invokeVirtual || ref_kind == JVM_REF_invokeSpecial) {
123 // Could do this for all ref_kinds, but would explode assembly code size.
124 trace_method_handle(_masm, buf);
125 }
126 __ stop(buf);
127 }
128
129 BLOCK_COMMENT("} verify_ref_kind");
130
131 __ bind(L);
132 }
133 #endif // ASSERT
134
135 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register target,
136 Register temp, bool for_compiler_entry) {
137 assert(method == Z_method, "interpreter calling convention");
138 __ verify_method_ptr(method);
139
140 assert(target != method, "don 't you kill the method reg!");
141
142 Label L_no_such_method;
143
144 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
145 // JVMTI events, such as single-stepping, are implemented partly
146 // by avoiding running compiled code in threads for which the
147 // event is enabled. Check here for interp_only_mode if these
148 // events CAN be enabled.
149 __ verify_thread();
150
151 Label run_compiled_code;
152
153 __ load_and_test_int(temp, Address(Z_thread, JavaThread::interp_only_mode_offset()));
154 __ z_bre(run_compiled_code);
155
156 // Null method test is replicated below in compiled case,
157 // it might be able to address across the verify_thread().
158 __ z_ltgr(temp, method);
159 __ z_bre(L_no_such_method);
160
161 __ z_lg(target, Address(method, Method::interpreter_entry_offset()));
162 __ z_br(target);
163
164 __ bind(run_compiled_code);
165 }
166
167 // Compiled case, either static or fall-through from runtime conditional.
168 __ z_ltgr(temp, method);
169 __ z_bre(L_no_such_method);
170
171 ByteSize offset = for_compiler_entry ?
172 Method::from_compiled_offset() : Method::from_interpreted_offset();
173 Address method_from(method, offset);
174
175 __ z_lg(target, method_from);
176 __ z_br(target);
177
178 __ bind(L_no_such_method);
179 assert(StubRoutines::throw_AbstractMethodError_entry() != NULL, "not yet generated!");
180 __ load_const_optimized(target, StubRoutines::throw_AbstractMethodError_entry());
181 __ z_br(target);
182 }
183
184 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
185 Register recv, Register method_temp,
186 Register temp2, Register temp3,
187 bool for_compiler_entry) {
188
189 // This is the initial entry point of a lazy method handle.
190 // After type checking, it picks up the invoker from the LambdaForm.
191 assert_different_registers(recv, method_temp, temp2, temp3);
192 assert(method_temp == Z_method, "required register for loading method");
193
194 BLOCK_COMMENT("jump_to_lambda_form {");
195
196 // Load the invoker, as MH -> MH.form -> LF.vmentry
197 __ verify_oop(recv);
198 __ load_heap_oop(method_temp,
199 Address(recv,
200 NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())),
201 noreg, noreg, IS_NOT_NULL);
202 __ verify_oop(method_temp);
203 __ load_heap_oop(method_temp,
204 Address(method_temp,
205 NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())),
206 noreg, noreg, IS_NOT_NULL);
207 __ verify_oop(method_temp);
208 __ load_heap_oop(method_temp,
209 Address(method_temp,
210 NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes())),
211 noreg, noreg, IS_NOT_NULL);
212 __ verify_oop(method_temp);
213 __ z_lg(method_temp,
214 Address(method_temp,
215 NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes())));
216
217 if (VerifyMethodHandles && !for_compiler_entry) {
218 // Make sure recv is already on stack.
219 NearLabel L;
220 Address paramSize(temp2, ConstMethod::size_of_parameters_offset());
221
222 __ z_lg(temp2, Address(method_temp, Method::const_offset()));
223 __ load_sized_value(temp2, paramSize, sizeof(u2), /*is_signed*/ false);
224 // if (temp2 != recv) stop
225 __ z_lg(temp2, __ argument_address(temp2, temp2, 0));
226 __ compare64_and_branch(temp2, recv, Assembler::bcondEqual, L);
227 __ stop("receiver not on stack");
228 __ BIND(L);
229 }
230
231 jump_from_method_handle(_masm, method_temp, temp2, Z_R0, for_compiler_entry);
232
233 BLOCK_COMMENT("} jump_to_lambda_form");
234 }
235
236 // code generation
237 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
238 vmIntrinsics::ID iid) {
239 const bool not_for_compiler_entry = false; // This is the interpreter entry.
240 assert(is_signature_polymorphic(iid), "expected invoke iid");
241
242 if (iid == vmIntrinsics::_invokeGeneric || iid == vmIntrinsics::_compiledLambdaForm) {
243 // Perhaps surprisingly, the symbolic references visible to Java
244 // are not directly used. They are linked to Java-generated
245 // adapters via MethodHandleNatives.linkMethod. They all allow an
246 // appendix argument.
247 __ should_not_reach_here(); // Empty stubs make SG sick.
248 return NULL;
249 }
250
251 // Z_R10: sender SP (must preserve; see prepare_to_jump_from_interprted)
252 // Z_method: method
253 // Z_ARG1 (Gargs): incoming argument list (must preserve)
254 Register Z_R4_param_size = Z_R4; // size of parameters
255 address code_start = __ pc();
256
257 // Here is where control starts out:
258 __ align(CodeEntryAlignment);
259
260 address entry_point = __ pc();
261
262 if (VerifyMethodHandles) {
263 Label L;
264 BLOCK_COMMENT("verify_intrinsic_id {");
265
266 // Supplement to 8139891: _intrinsic_id exceeded 1-byte size limit.
267 if (Method::intrinsic_id_size_in_bytes() == 1) {
268 __ z_cli(Address(Z_method, Method::intrinsic_id_offset_in_bytes()), (int)iid);
269 } else {
270 assert(Method::intrinsic_id_size_in_bytes() == 2, "size error: check Method::_intrinsic_id");
271 __ z_lh(Z_R0_scratch, Address(Z_method, Method::intrinsic_id_offset_in_bytes()));
272 __ z_chi(Z_R0_scratch, (int)iid);
273 }
274 __ z_bre(L);
275
276 if (iid == vmIntrinsics::_linkToVirtual || iid == vmIntrinsics::_linkToSpecial) {
277 // Could do this for all kinds, but would explode assembly code size.
278 trace_method_handle(_masm, "bad Method::intrinsic_id");
279 }
280
281 __ stop("bad Method::intrinsic_id");
282 __ bind(L);
283
284 BLOCK_COMMENT("} verify_intrinsic_id");
285 }
286
287 // First task: Find out how big the argument list is.
288 Address Z_R4_first_arg_addr;
289 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
290
291 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic,
292 "must be _invokeBasic or a linkTo intrinsic");
293
294 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
295 Address paramSize(Z_R1_scratch, ConstMethod::size_of_parameters_offset());
296
297 __ z_lg(Z_R1_scratch, Address(Z_method, Method::const_offset()));
298 __ load_sized_value(Z_R4_param_size, paramSize, sizeof(u2), /*is_signed*/ false);
299 Z_R4_first_arg_addr = __ argument_address(Z_R4_param_size, Z_R4_param_size, 0);
300 } else {
301 DEBUG_ONLY(Z_R4_param_size = noreg);
302 }
303
304 Register Z_mh = noreg;
305 if (!is_signature_polymorphic_static(iid)) {
306 Z_mh = Z_ARG4;
307 __ z_lg(Z_mh, Z_R4_first_arg_addr);
308 DEBUG_ONLY(Z_R4_param_size = noreg);
309 }
310
311 // Z_R4_first_arg_addr is live!
312
313 trace_method_handle_interpreter_entry(_masm, iid);
314
315 if (iid == vmIntrinsics::_invokeBasic) {
316 __ pc(); // just for the block comment
317 generate_method_handle_dispatch(_masm, iid, Z_mh, noreg, not_for_compiler_entry);
318 } else {
319 // Adjust argument list by popping the trailing MemberName argument.
320 Register Z_recv = noreg;
321
322 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
323 // Load the receiver (not the MH; the actual MemberName's receiver)
324 // up from the interpreter stack.
325 __ z_lg(Z_recv = Z_R5, Z_R4_first_arg_addr);
326 DEBUG_ONLY(Z_R4_param_size = noreg);
327 }
328
329 Register Z_member = Z_method; // MemberName ptr; incoming method ptr is dead now
330
331 __ z_lg(Z_member, __ argument_address(constant(1)));
332 __ add2reg(Z_esp, Interpreter::stackElementSize);
333 generate_method_handle_dispatch(_masm, iid, Z_recv, Z_member, not_for_compiler_entry);
334 }
335
336 return entry_point;
337 }
338
339 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
340 vmIntrinsics::ID iid,
341 Register receiver_reg,
342 Register member_reg,
343 bool for_compiler_entry) {
344 assert(is_signature_polymorphic(iid), "expected invoke iid");
345
346 Register temp1 = for_compiler_entry ? Z_R10 : Z_R6;
347 Register temp2 = Z_R12;
348 Register temp3 = Z_R11;
349 Register temp4 = Z_R13;
350
351 if (for_compiler_entry) {
352 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : Z_ARG1),
353 "only valid assignment");
354 }
355 if (receiver_reg != noreg) {
356 assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg);
357 }
358 if (member_reg != noreg) {
359 assert_different_registers(temp1, temp2, temp3, temp4, member_reg);
360 }
361 if (!for_compiler_entry) { // Don't trash last SP.
362 assert_different_registers(temp1, temp2, temp3, temp4, Z_R10);
363 }
364
365 if (iid == vmIntrinsics::_invokeBasic) {
366 __ pc(); // Just for the block comment.
367 // Indirect through MH.form.vmentry.vmtarget.
368 jump_to_lambda_form(_masm, receiver_reg, Z_method, Z_R1, temp3, for_compiler_entry);
369 return;
370 }
371
372 // The method is a member invoker used by direct method handles.
373 if (VerifyMethodHandles) {
374 // Make sure the trailing argument really is a MemberName (caller responsibility).
375 verify_klass(_masm, member_reg,
376 SystemDictionary::WK_KLASS_ENUM_NAME(MemberName_klass),
377 temp1, temp2,
378 "MemberName required for invokeVirtual etc.");
379 }
380
381 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));
382 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));
383 Address member_vmtarget(member_reg, NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes()));
384 Address vmtarget_method(Z_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes()));
385 Register temp1_recv_klass = temp1;
386
387 if (iid != vmIntrinsics::_linkToStatic) {
388 __ verify_oop(receiver_reg);
389 if (iid == vmIntrinsics::_linkToSpecial) {
390 // Don't actually load the klass; just null-check the receiver.
391 __ null_check(receiver_reg);
392 } else {
393 // Load receiver klass itself.
394 __ null_check(receiver_reg, Z_R0, oopDesc::klass_offset_in_bytes());
395 __ load_klass(temp1_recv_klass, receiver_reg);
396 __ verify_klass_ptr(temp1_recv_klass);
397 }
398 BLOCK_COMMENT("check_receiver {");
399 // The receiver for the MemberName must be in receiver_reg.
400 // Check the receiver against the MemberName.clazz.
401 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
402 // Did not load it above...
403 __ load_klass(temp1_recv_klass, receiver_reg);
404 __ verify_klass_ptr(temp1_recv_klass);
405 }
406
407 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
408 NearLabel L_ok;
409 Register temp2_defc = temp2;
410
411 __ load_heap_oop(temp2_defc, member_clazz,
412 noreg, noreg, IS_NOT_NULL);
413 load_klass_from_Class(_masm, temp2_defc, temp3, temp4);
414 __ verify_klass_ptr(temp2_defc);
415 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok);
416 // If we get here, the type check failed!
417 __ stop("receiver class disagrees with MemberName.clazz");
418 __ bind(L_ok);
419 }
420 BLOCK_COMMENT("} check_receiver");
421 }
422 if (iid == vmIntrinsics::_linkToSpecial || iid == vmIntrinsics::_linkToStatic) {
423 DEBUG_ONLY(temp1_recv_klass = noreg); // These guys didn't load the recv_klass.
424 }
425
426 // Live registers at this point:
427 // member_reg - MemberName that was the trailing argument.
428 // temp1_recv_klass - Klass of stacked receiver, if needed.
429 // Z_R10 - Interpreter linkage if interpreted.
430
431 bool method_is_live = false;
432
433 switch (iid) {
434 case vmIntrinsics::_linkToSpecial:
435 if (VerifyMethodHandles) {
436 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
437 }
438 __ load_heap_oop(Z_method, member_vmtarget,
439 noreg, noreg, IS_NOT_NULL);
440 __ z_lg(Z_method, vmtarget_method);
441 method_is_live = true;
442 break;
443
444 case vmIntrinsics::_linkToStatic:
445 if (VerifyMethodHandles) {
446 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
447 }
448 __ load_heap_oop(Z_method, member_vmtarget,
449 noreg, noreg, IS_NOT_NULL);
450 __ z_lg(Z_method, vmtarget_method);
451 method_is_live = true;
452 break;
453
454 case vmIntrinsics::_linkToVirtual: {
455 // Same as TemplateTable::invokevirtual, minus the CP setup and profiling.
456 if (VerifyMethodHandles) {
457 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
458 }
459
460 // Pick out the vtable index from the MemberName, and then we can discard it.
461 Register temp2_index = temp2;
462 __ z_lg(temp2_index, member_vmindex);
463
464 if (VerifyMethodHandles) {
465 // if (member_vmindex < 0) stop
466 NearLabel L_index_ok;
467 __ compare32_and_branch(temp2_index, constant(0), Assembler::bcondNotLow, L_index_ok);
468 __ stop("no virtual index");
469 __ BIND(L_index_ok);
470 }
471
472 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
473 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
474
475 // Get target method and entry point.
476 __ lookup_virtual_method(temp1_recv_klass, temp2_index, Z_method);
477 method_is_live = true;
478 break;
479 }
480
481 case vmIntrinsics::_linkToInterface: {
482 // Same as TemplateTable::invokeinterface, minus the CP setup
483 // and profiling, with different argument motion.
484 if (VerifyMethodHandles) {
485 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
486 }
487
488 Register temp3_intf = temp3;
489
490 __ load_heap_oop(temp3_intf, member_clazz,
491 noreg, noreg, IS_NOT_NULL);
492 load_klass_from_Class(_masm, temp3_intf, temp2, temp4);
493
494 Register Z_index = Z_method;
495
496 __ z_lg(Z_index, member_vmindex);
497
498 if (VerifyMethodHandles) {
499 NearLabel L;
500 // if (member_vmindex < 0) stop
501 __ compare32_and_branch(Z_index, constant(0), Assembler::bcondNotLow, L);
502 __ stop("invalid vtable index for MH.invokeInterface");
503 __ bind(L);
504 }
505
506 // Given interface, index, and recv klass, dispatch to the implementation method.
507 Label L_no_such_interface;
508 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
509 // Note: next two args must be the same:
510 Z_index, Z_method, temp2,
511 L_no_such_interface);
512 jump_from_method_handle(_masm, Z_method, temp2, Z_R0, for_compiler_entry);
513
514 __ bind(L_no_such_interface);
515
516 // Throw exception.
517 __ load_const_optimized(Z_R1, StubRoutines::throw_IncompatibleClassChangeError_entry());
518 __ z_br(Z_R1);
519 break;
520 }
521
522 default:
523 fatal("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid));
524 break;
525 }
526
527 if (method_is_live) {
528 // Live at this point: Z_method, O5_savedSP (if interpreted).
529
530 // After figuring out which concrete method to call, jump into it.
531 // Note that this works in the interpreter with no data motion.
532 // But the compiled version will require that rcx_recv be shifted out.
533 jump_from_method_handle(_masm, Z_method, temp1, Z_R0, for_compiler_entry);
534 }
535 }
536
537 #ifndef PRODUCT
538 void trace_method_handle_stub(const char* adaptername,
539 oopDesc* mh,
540 intptr_t* sender_sp,
541 intptr_t* args,
542 intptr_t* tracing_fp) {
543 bool has_mh = (strstr(adaptername, "/static") == NULL &&
544 strstr(adaptername, "linkTo") == NULL); // Static linkers don't have MH.
545 const char* mh_reg_name = has_mh ? "Z_R4_mh" : "Z_R4";
546 tty->print_cr("MH %s %s=" INTPTR_FORMAT " sender_sp=" INTPTR_FORMAT " args=" INTPTR_FORMAT,
547 adaptername, mh_reg_name,
548 p2i(mh), p2i(sender_sp), p2i(args));
549
550 if (Verbose) {
551 // Dumping last frame with frame::describe.
552
553 JavaThread* p = JavaThread::active();
554
555 ResourceMark rm;
556 PRESERVE_EXCEPTION_MARK; // May not be needed by safer and unexpensive here.
557 FrameValues values;
558
559 // Note: We want to allow trace_method_handle from any call site.
560 // While trace_method_handle creates a frame, it may be entered
561 // without a valid return PC in Z_R14 (e.g. not just after a call).
562 // Walking that frame could lead to failures due to that invalid PC.
563 // => carefully detect that frame when doing the stack walking.
564
565 // Walk up to the right frame using the "tracing_fp" argument.
566 frame cur_frame = os::current_frame(); // Current C frame.
567
568 while (cur_frame.fp() != tracing_fp) {
569 cur_frame = os::get_sender_for_C_frame(&cur_frame);
570 }
571
572 // Safely create a frame and call frame::describe.
573 intptr_t *dump_sp = cur_frame.sender_sp();
574 intptr_t *dump_fp = cur_frame.link();
575
576 bool walkable = has_mh; // Whether the traced frame shoud be walkable.
577
578 // The sender for cur_frame is the caller of trace_method_handle.
579 if (walkable) {
580 // The previous definition of walkable may have to be refined
581 // if new call sites cause the next frame constructor to start
582 // failing. Alternatively, frame constructors could be
583 // modified to support the current or future non walkable
584 // frames (but this is more intrusive and is not considered as
585 // part of this RFE, which will instead use a simpler output).
586 frame dump_frame = frame(dump_sp);
587 dump_frame.describe(values, 1);
588 } else {
589 // Robust dump for frames which cannot be constructed from sp/younger_sp
590 // Add descriptions without building a Java frame to avoid issues.
591 values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>");
592 values.describe(-1, dump_sp, "sp");
593 }
594
595 bool has_args = has_mh; // Whether Z_esp is meaningful.
596
597 // Mark args, if seems valid (may not be valid for some adapters).
598 if (has_args) {
599 if ((args >= dump_sp) && (args < dump_fp)) {
600 values.describe(-1, args, "*Z_esp");
601 }
602 }
603
604 // Note: the unextended_sp may not be correct.
605 tty->print_cr(" stack layout:");
606 values.print(p);
607 if (has_mh && oopDesc::is_oop(mh)) {
608 mh->print();
609 if (java_lang_invoke_MethodHandle::is_instance(mh)) {
610 if (java_lang_invoke_MethodHandle::form_offset_in_bytes() != 0) {
611 java_lang_invoke_MethodHandle::form(mh)->print();
612 }
613 }
614 }
615 }
616 }
617
618 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
619 if (!TraceMethodHandles) { return; }
620
621 // If arg registers are contiguous, we can use STMG/LMG.
622 assert((Z_ARG5->encoding() - Z_ARG1->encoding() + 1) == RegisterImpl::number_of_arg_registers, "Oops");
623
624 BLOCK_COMMENT("trace_method_handle {");
625
626 // Save argument registers (they are used in raise exception stub).
627 // Argument registers have contiguous register numbers -> we can use stmg/lmg.
628 __ z_stmg(Z_ARG1, Z_ARG5, 16, Z_SP);
629
630 // Setup arguments.
631 __ z_lgr(Z_ARG2, Z_ARG4); // mh, see generate_method_handle_interpreter_entry()
632 __ z_lgr(Z_ARG3, Z_R10); // sender_sp
633 __ z_lgr(Z_ARG4, Z_esp);
634 __ load_const_optimized(Z_ARG1, (void *)adaptername);
635 __ z_lgr(Z_ARG5, Z_SP); // tracing_fp
636 __ save_return_pc(); // saves Z_R14
637 __ push_frame_abi160(0);
638 __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub));
639 __ pop_frame();
640 __ restore_return_pc(); // restores to Z_R14
641
642 // Restore argument registers
643 __ z_lmg(Z_ARG1, Z_ARG5, 16, Z_SP);
644 __ zap_from_to(Z_SP, Z_SP, Z_R0, Z_R1, 50, -1);
645 __ zap_from_to(Z_SP, Z_SP, Z_R0, Z_R1, -1, 5);
646
647 BLOCK_COMMENT("} trace_method_handle");
648 }
649 #endif // !PRODUCT