1 /*
2 * Copyright (c) 1997, 2018, 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 "jvm.h"
27 #include "asm/macroAssembler.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "interpreter/interpreter.hpp"
30 #include "interpreter/interpreterRuntime.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 #define __ _masm->
38
39 #ifdef PRODUCT
40 #define BLOCK_COMMENT(str) /* nothing */
41 #define STOP(error) stop(error)
42 #else
43 #define BLOCK_COMMENT(str) __ block_comment(str)
44 #define STOP(error) block_comment(error); __ stop(error)
45 #endif
46
47 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
48
49 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {
50 if (VerifyMethodHandles)
51 verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class),
52 "MH argument is a Class");
53 __ movptr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset_in_bytes()));
54 }
55
56 #ifdef ASSERT
57 static int check_nonzero(const char* xname, int x) {
58 assert(x != 0, "%s should be nonzero", xname);
59 return x;
60 }
61 #define NONZERO(x) check_nonzero(#x, x)
62 #else //ASSERT
63 #define NONZERO(x) (x)
64 #endif //ASSERT
65
66 #ifdef ASSERT
67 void MethodHandles::verify_klass(MacroAssembler* _masm,
68 Register obj, SystemDictionary::WKID klass_id,
69 const char* error_message) {
70 InstanceKlass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
71 Klass* klass = SystemDictionary::well_known_klass(klass_id);
72 Register temp = rdi;
73 Register temp2 = noreg;
74 LP64_ONLY(temp2 = rscratch1); // used by MacroAssembler::cmpptr
75 Label L_ok, L_bad;
76 BLOCK_COMMENT("verify_klass {");
77 __ verify_oop(obj);
78 __ testptr(obj, obj);
79 __ jcc(Assembler::zero, L_bad);
80 __ push(temp); if (temp2 != noreg) __ push(temp2);
81 #define UNPUSH { if (temp2 != noreg) __ pop(temp2); __ pop(temp); }
82 __ load_klass(temp, obj);
83 __ cmpptr(temp, ExternalAddress((address) klass_addr));
84 __ jcc(Assembler::equal, L_ok);
85 intptr_t super_check_offset = klass->super_check_offset();
86 __ movptr(temp, Address(temp, super_check_offset));
87 __ cmpptr(temp, ExternalAddress((address) klass_addr));
88 __ jcc(Assembler::equal, L_ok);
89 UNPUSH;
90 __ bind(L_bad);
91 __ STOP(error_message);
92 __ BIND(L_ok);
93 UNPUSH;
94 BLOCK_COMMENT("} verify_klass");
95 }
96
97 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
98 Label L;
99 BLOCK_COMMENT("verify_ref_kind {");
100 __ movl(temp, Address(member_reg, NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes())));
101 __ shrl(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
102 __ andl(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
103 __ cmpl(temp, ref_kind);
104 __ jcc(Assembler::equal, L);
105 { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
106 jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
107 if (ref_kind == JVM_REF_invokeVirtual ||
108 ref_kind == JVM_REF_invokeSpecial)
109 // could do this for all ref_kinds, but would explode assembly code size
110 trace_method_handle(_masm, buf);
111 __ STOP(buf);
112 }
113 BLOCK_COMMENT("} verify_ref_kind");
114 __ bind(L);
115 }
116
117 #endif //ASSERT
118
119 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
120 bool for_compiler_entry) {
121 assert(method == rbx, "interpreter calling convention");
122
123 Label L_no_such_method;
124 __ testptr(rbx, rbx);
125 __ jcc(Assembler::zero, L_no_such_method);
126
127 __ verify_method_ptr(method);
128
129 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
130 Label run_compiled_code;
131 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
132 // compiled code in threads for which the event is enabled. Check here for
133 // interp_only_mode if these events CAN be enabled.
134 #ifdef _LP64
135 Register rthread = r15_thread;
136 #else
137 Register rthread = temp;
138 __ get_thread(rthread);
139 #endif
140 // interp_only is an int, on little endian it is sufficient to test the byte only
141 // Is a cmpl faster?
142 __ cmpb(Address(rthread, JavaThread::interp_only_mode_offset()), 0);
143 __ jccb(Assembler::zero, run_compiled_code);
144 __ jmp(Address(method, Method::interpreter_entry_offset()));
145 __ BIND(run_compiled_code);
146 }
147
148 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
149 Method::from_interpreted_offset();
150 __ jmp(Address(method, entry_offset));
151
152 __ bind(L_no_such_method);
153 __ jump(RuntimeAddress(StubRoutines::throw_AbstractMethodError_entry()));
154 }
155
156 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
157 Register recv, Register method_temp,
158 Register temp2,
159 bool for_compiler_entry) {
160 BLOCK_COMMENT("jump_to_lambda_form {");
161 // This is the initial entry point of a lazy method handle.
162 // After type checking, it picks up the invoker from the LambdaForm.
163 assert_different_registers(recv, method_temp, temp2);
164 assert(recv != noreg, "required register");
165 assert(method_temp == rbx, "required register for loading method");
166
167 //NOT_PRODUCT({ FlagSetting fs(TraceMethodHandles, true); trace_method_handle(_masm, "LZMH"); });
168
169 // Load the invoker, as MH -> MH.form -> LF.vmentry
170 __ resolve_for_read(0, recv);
171 __ verify_oop(recv);
172 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())), temp2);
173 __ resolve_for_read(0, method_temp);
174 __ verify_oop(method_temp);
175 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())), temp2);
176 __ resolve_for_read(0, method_temp);
177 __ verify_oop(method_temp);
178 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes())), temp2);
179 __ resolve_for_read(OOP_NOT_NULL, method_temp);
180 __ verify_oop(method_temp);
181 __ movptr(method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes())));
182
183 if (VerifyMethodHandles && !for_compiler_entry) {
184 // make sure recv is already on stack
185 __ movptr(temp2, Address(method_temp, Method::const_offset()));
186 __ load_sized_value(temp2,
187 Address(temp2, ConstMethod::size_of_parameters_offset()),
188 sizeof(u2), /*is_signed*/ false);
189 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
190 __ movptr(temp2, __ argument_address(temp2, -1));
191 Label L;
192 __ cmpoop(recv, temp2);
193 __ jcc(Assembler::equal, L);
194 __ movptr(rax, temp2);
195 __ STOP("receiver not on stack");
196 __ BIND(L);
197 }
198
199 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
200 BLOCK_COMMENT("} jump_to_lambda_form");
201 }
202
203
204 // Code generation
205 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
206 vmIntrinsics::ID iid) {
207 const bool not_for_compiler_entry = false; // this is the interpreter entry
208 assert(is_signature_polymorphic(iid), "expected invoke iid");
209 if (iid == vmIntrinsics::_invokeGeneric ||
210 iid == vmIntrinsics::_compiledLambdaForm) {
211 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
212 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
213 // They all allow an appendix argument.
214 __ hlt(); // empty stubs make SG sick
215 return NULL;
216 }
217
218 // rsi/r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)
219 // rbx: Method*
220 // rdx: argument locator (parameter slot count, added to rsp)
221 // rcx: used as temp to hold mh or receiver
222 // rax, rdi: garbage temps, blown away
223 Register rdx_argp = rdx; // argument list ptr, live on error paths
224 Register rax_temp = rax;
225 Register rcx_mh = rcx; // MH receiver; dies quickly and is recycled
226 Register rbx_method = rbx; // eventual target of this invocation
227
228 // here's where control starts out:
229 __ align(CodeEntryAlignment);
230 address entry_point = __ pc();
231
232 if (VerifyMethodHandles) {
233 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
234
235 Label L;
236 BLOCK_COMMENT("verify_intrinsic_id {");
237 __ cmpw(Address(rbx_method, Method::intrinsic_id_offset_in_bytes()), (int) iid);
238 __ jcc(Assembler::equal, L);
239 if (iid == vmIntrinsics::_linkToVirtual ||
240 iid == vmIntrinsics::_linkToSpecial) {
241 // could do this for all kinds, but would explode assembly code size
242 trace_method_handle(_masm, "bad Method*::intrinsic_id");
243 }
244 __ STOP("bad Method*::intrinsic_id");
245 __ bind(L);
246 BLOCK_COMMENT("} verify_intrinsic_id");
247 }
248
249 // First task: Find out how big the argument list is.
250 Address rdx_first_arg_addr;
251 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
252 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
253 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
254 __ movptr(rdx_argp, Address(rbx_method, Method::const_offset()));
255 __ load_sized_value(rdx_argp,
256 Address(rdx_argp, ConstMethod::size_of_parameters_offset()),
257 sizeof(u2), /*is_signed*/ false);
258 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
259 rdx_first_arg_addr = __ argument_address(rdx_argp, -1);
260 } else {
261 DEBUG_ONLY(rdx_argp = noreg);
262 }
263
264 if (!is_signature_polymorphic_static(iid)) {
265 __ movptr(rcx_mh, rdx_first_arg_addr);
266 DEBUG_ONLY(rdx_argp = noreg);
267 }
268
269 // rdx_first_arg_addr is live!
270
271 trace_method_handle_interpreter_entry(_masm, iid);
272
273 if (iid == vmIntrinsics::_invokeBasic) {
274 generate_method_handle_dispatch(_masm, iid, rcx_mh, noreg, not_for_compiler_entry);
275
276 } else {
277 // Adjust argument list by popping the trailing MemberName argument.
278 Register rcx_recv = noreg;
279 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
280 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
281 __ movptr(rcx_recv = rcx, rdx_first_arg_addr);
282 }
283 DEBUG_ONLY(rdx_argp = noreg);
284 Register rbx_member = rbx_method; // MemberName ptr; incoming method ptr is dead now
285 __ pop(rax_temp); // return address
286 __ pop(rbx_member); // extract last argument
287 __ push(rax_temp); // re-push return address
288 generate_method_handle_dispatch(_masm, iid, rcx_recv, rbx_member, not_for_compiler_entry);
289 }
290
291 return entry_point;
292 }
293
294 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
295 vmIntrinsics::ID iid,
296 Register receiver_reg,
297 Register member_reg,
298 bool for_compiler_entry) {
299 assert(is_signature_polymorphic(iid), "expected invoke iid");
300 Register rbx_method = rbx; // eventual target of this invocation
301 // temps used in this code are not used in *either* compiled or interpreted calling sequences
302 #ifdef _LP64
303 Register temp1 = rscratch1;
304 Register temp2 = rscratch2;
305 Register temp3 = rax;
306 if (for_compiler_entry) {
307 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : j_rarg0), "only valid assignment");
308 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
309 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
310 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
311 }
312 #else
313 Register temp1 = (for_compiler_entry ? rsi : rdx);
314 Register temp2 = rdi;
315 Register temp3 = rax;
316 if (for_compiler_entry) {
317 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : rcx), "only valid assignment");
318 assert_different_registers(temp1, rcx, rdx);
319 assert_different_registers(temp2, rcx, rdx);
320 assert_different_registers(temp3, rcx, rdx);
321 }
322 #endif
323 else {
324 assert_different_registers(temp1, temp2, temp3, saved_last_sp_register()); // don't trash lastSP
325 }
326 assert_different_registers(temp1, temp2, temp3, receiver_reg);
327 assert_different_registers(temp1, temp2, temp3, member_reg);
328
329 if (iid == vmIntrinsics::_invokeBasic) {
330 // indirect through MH.form.vmentry.vmtarget
331 jump_to_lambda_form(_masm, receiver_reg, rbx_method, temp1, for_compiler_entry);
332
333 } else {
334 // The method is a member invoker used by direct method handles.
335 if (VerifyMethodHandles) {
336 // make sure the trailing argument really is a MemberName (caller responsibility)
337 verify_klass(_masm, member_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_invoke_MemberName),
338 "MemberName required for invokeVirtual etc.");
339 }
340
341 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));
342 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));
343 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes()));
344 Address vmtarget_method( rbx_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes()));
345
346 Register temp1_recv_klass = temp1;
347 if (iid != vmIntrinsics::_linkToStatic) {
348 __ verify_oop(receiver_reg);
349 if (iid == vmIntrinsics::_linkToSpecial) {
350 // Don't actually load the klass; just null-check the receiver.
351 __ null_check(receiver_reg);
352 } else {
353 // load receiver klass itself
354 __ null_check(receiver_reg, oopDesc::klass_offset_in_bytes());
355 __ load_klass(temp1_recv_klass, receiver_reg);
356 __ verify_klass_ptr(temp1_recv_klass);
357 }
358 BLOCK_COMMENT("check_receiver {");
359 // The receiver for the MemberName must be in receiver_reg.
360 // Check the receiver against the MemberName.clazz
361 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
362 // Did not load it above...
363 __ load_klass(temp1_recv_klass, receiver_reg);
364 __ verify_klass_ptr(temp1_recv_klass);
365 }
366 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
367 Label L_ok;
368 Register temp2_defc = temp2;
369 __ load_heap_oop(temp2_defc, member_clazz, temp3);
370 load_klass_from_Class(_masm, temp2_defc);
371 __ verify_klass_ptr(temp2_defc);
372 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
373 // If we get here, the type check failed!
374 __ STOP("receiver class disagrees with MemberName.clazz");
375 __ bind(L_ok);
376 }
377 BLOCK_COMMENT("} check_receiver");
378 }
379 if (iid == vmIntrinsics::_linkToSpecial ||
380 iid == vmIntrinsics::_linkToStatic) {
381 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
382 }
383
384 // Live registers at this point:
385 // member_reg - MemberName that was the trailing argument
386 // temp1_recv_klass - klass of stacked receiver, if needed
387 // rsi/r13 - interpreter linkage (if interpreted)
388 // rcx, rdx, rsi, rdi, r8 - compiler arguments (if compiled)
389
390 __ resolve_for_read(0, member_reg);
391 Label L_incompatible_class_change_error;
392 switch (iid) {
393 case vmIntrinsics::_linkToSpecial:
394 if (VerifyMethodHandles) {
395 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
396 }
397 __ load_heap_oop(rbx_method, member_vmtarget);
398 __ resolve_for_read(0, rbx_method);
399 __ movptr(rbx_method, vmtarget_method);
400 break;
401
402 case vmIntrinsics::_linkToStatic:
403 if (VerifyMethodHandles) {
404 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
405 }
406 __ load_heap_oop(rbx_method, member_vmtarget);
407 __ resolve_for_read(0, rbx_method);
408 __ movptr(rbx_method, vmtarget_method);
409 break;
410
411 case vmIntrinsics::_linkToVirtual:
412 {
413 // same as TemplateTable::invokevirtual,
414 // minus the CP setup and profiling:
415
416 if (VerifyMethodHandles) {
417 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
418 }
419
420 // pick out the vtable index from the MemberName, and then we can discard it:
421 Register temp2_index = temp2;
422 __ movptr(temp2_index, member_vmindex);
423
424 if (VerifyMethodHandles) {
425 Label L_index_ok;
426 __ cmpl(temp2_index, 0);
427 __ jcc(Assembler::greaterEqual, L_index_ok);
428 __ STOP("no virtual index");
429 __ BIND(L_index_ok);
430 }
431
432 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
433 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
434
435 // get target Method* & entry point
436 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rbx_method);
437 break;
438 }
439
440 case vmIntrinsics::_linkToInterface:
441 {
442 // same as TemplateTable::invokeinterface
443 // (minus the CP setup and profiling, with different argument motion)
444 if (VerifyMethodHandles) {
445 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
446 }
447
448 Register temp3_intf = temp3;
449 __ load_heap_oop(temp3_intf, member_clazz);
450 load_klass_from_Class(_masm, temp3_intf);
451 __ verify_klass_ptr(temp3_intf);
452
453 Register rbx_index = rbx_method;
454 __ movptr(rbx_index, member_vmindex);
455 if (VerifyMethodHandles) {
456 Label L;
457 __ cmpl(rbx_index, 0);
458 __ jcc(Assembler::greaterEqual, L);
459 __ STOP("invalid vtable index for MH.invokeInterface");
460 __ bind(L);
461 }
462
463 // given intf, index, and recv klass, dispatch to the implementation method
464 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
465 // note: next two args must be the same:
466 rbx_index, rbx_method,
467 temp2,
468 L_incompatible_class_change_error);
469 break;
470 }
471
472 default:
473 fatal("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid));
474 break;
475 }
476
477 // Live at this point:
478 // rbx_method
479 // rsi/r13 (if interpreted)
480
481 // After figuring out which concrete method to call, jump into it.
482 // Note that this works in the interpreter with no data motion.
483 // But the compiled version will require that rcx_recv be shifted out.
484 __ verify_method_ptr(rbx_method);
485 jump_from_method_handle(_masm, rbx_method, temp1, for_compiler_entry);
486
487 if (iid == vmIntrinsics::_linkToInterface) {
488 __ bind(L_incompatible_class_change_error);
489 __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
490 }
491 }
492 }
493
494 #ifndef PRODUCT
495 void trace_method_handle_stub(const char* adaptername,
496 oop mh,
497 intptr_t* saved_regs,
498 intptr_t* entry_sp) {
499 // called as a leaf from native code: do not block the JVM!
500 bool has_mh = (strstr(adaptername, "/static") == NULL &&
501 strstr(adaptername, "linkTo") == NULL); // static linkers don't have MH
502 const char* mh_reg_name = has_mh ? "rcx_mh" : "rcx";
503 tty->print_cr("MH %s %s=" PTR_FORMAT " sp=" PTR_FORMAT,
504 adaptername, mh_reg_name,
505 p2i(mh), p2i(entry_sp));
506
507 if (Verbose) {
508 tty->print_cr("Registers:");
509 const int saved_regs_count = RegisterImpl::number_of_registers;
510 for (int i = 0; i < saved_regs_count; i++) {
511 Register r = as_Register(i);
512 // The registers are stored in reverse order on the stack (by pusha).
513 tty->print("%3s=" PTR_FORMAT, r->name(), saved_regs[((saved_regs_count - 1) - i)]);
514 if ((i + 1) % 4 == 0) {
515 tty->cr();
516 } else {
517 tty->print(", ");
518 }
519 }
520 tty->cr();
521
522 {
523 // dumping last frame with frame::describe
524
525 JavaThread* p = JavaThread::active();
526
527 ResourceMark rm;
528 PRESERVE_EXCEPTION_MARK; // may not be needed by safer and unexpensive here
529 FrameValues values;
530
531 // Note: We want to allow trace_method_handle from any call site.
532 // While trace_method_handle creates a frame, it may be entered
533 // without a PC on the stack top (e.g. not just after a call).
534 // Walking that frame could lead to failures due to that invalid PC.
535 // => carefully detect that frame when doing the stack walking
536
537 // Current C frame
538 frame cur_frame = os::current_frame();
539
540 // Robust search of trace_calling_frame (independant of inlining).
541 // Assumes saved_regs comes from a pusha in the trace_calling_frame.
542 assert(cur_frame.sp() < saved_regs, "registers not saved on stack ?");
543 frame trace_calling_frame = os::get_sender_for_C_frame(&cur_frame);
544 while (trace_calling_frame.fp() < saved_regs) {
545 trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame);
546 }
547
548 // safely create a frame and call frame::describe
549 intptr_t *dump_sp = trace_calling_frame.sender_sp();
550 intptr_t *dump_fp = trace_calling_frame.link();
551
552 bool walkable = has_mh; // whether the traced frame shoud be walkable
553
554 if (walkable) {
555 // The previous definition of walkable may have to be refined
556 // if new call sites cause the next frame constructor to start
557 // failing. Alternatively, frame constructors could be
558 // modified to support the current or future non walkable
559 // frames (but this is more intrusive and is not considered as
560 // part of this RFE, which will instead use a simpler output).
561 frame dump_frame = frame(dump_sp, dump_fp);
562 dump_frame.describe(values, 1);
563 } else {
564 // Stack may not be walkable (invalid PC above FP):
565 // Add descriptions without building a Java frame to avoid issues
566 values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>");
567 values.describe(-1, dump_sp, "sp for #1");
568 }
569 values.describe(-1, entry_sp, "raw top of stack");
570
571 tty->print_cr("Stack layout:");
572 values.print(p);
573 }
574 if (has_mh && oopDesc::is_oop(mh)) {
575 mh->print();
576 if (java_lang_invoke_MethodHandle::is_instance(mh)) {
577 if (java_lang_invoke_MethodHandle::form_offset_in_bytes() != 0)
578 java_lang_invoke_MethodHandle::form(mh)->print();
579 }
580 }
581 }
582 }
583
584 // The stub wraps the arguments in a struct on the stack to avoid
585 // dealing with the different calling conventions for passing 6
586 // arguments.
587 struct MethodHandleStubArguments {
588 const char* adaptername;
589 oopDesc* mh;
590 intptr_t* saved_regs;
591 intptr_t* entry_sp;
592 };
593 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) {
594 trace_method_handle_stub(args->adaptername,
595 args->mh,
596 args->saved_regs,
597 args->entry_sp);
598 }
599
600 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
601 if (!TraceMethodHandles) return;
602 BLOCK_COMMENT(err_msg("trace_method_handle %s {", adaptername));
603 __ enter();
604 __ andptr(rsp, -16); // align stack if needed for FPU state
605 __ pusha();
606 __ mov(rbx, rsp); // for retreiving saved_regs
607 // Note: saved_regs must be in the entered frame for the
608 // robust stack walking implemented in trace_method_handle_stub.
609
610 // save FP result, valid at some call sites (adapter_opt_return_float, ...)
611 __ increment(rsp, -2 * wordSize);
612 if (UseSSE >= 2) {
613 __ movdbl(Address(rsp, 0), xmm0);
614 } else if (UseSSE == 1) {
615 __ movflt(Address(rsp, 0), xmm0);
616 } else {
617 __ fst_d(Address(rsp, 0));
618 }
619
620 // Incoming state:
621 // rcx: method handle
622 //
623 // To avoid calling convention issues, build a record on the stack
624 // and pass the pointer to that instead.
625 __ push(rbp); // entry_sp (with extra align space)
626 __ push(rbx); // pusha saved_regs
627 __ push(rcx); // mh
628 __ push(rcx); // slot for adaptername
629 __ movptr(Address(rsp, 0), (intptr_t) adaptername);
630 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub_wrapper), rsp);
631 __ increment(rsp, sizeof(MethodHandleStubArguments));
632
633 if (UseSSE >= 2) {
634 __ movdbl(xmm0, Address(rsp, 0));
635 } else if (UseSSE == 1) {
636 __ movflt(xmm0, Address(rsp, 0));
637 } else {
638 __ fld_d(Address(rsp, 0));
639 }
640 __ increment(rsp, 2 * wordSize);
641
642 __ popa();
643 __ leave();
644 BLOCK_COMMENT("} trace_method_handle");
645 }
646 #endif //PRODUCT