1 /*
2 * Copyright (c) 1997, 2025, 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 "asm/macroAssembler.hpp"
26 #include "classfile/vmClasses.hpp"
27 #include "compiler/disassembler.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "interpreter/interpreter.hpp"
30 #include "interpreter/interpreterRuntime.hpp"
31 #include "jvm.h"
32 #include "logging/log.hpp"
33 #include "logging/logStream.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "prims/jvmtiExport.hpp"
37 #include "prims/methodHandles.hpp"
38 #include "runtime/flags/flagSetting.hpp"
39 #include "runtime/frame.inline.hpp"
40 #include "runtime/stubRoutines.hpp"
41 #include "utilities/formatBuffer.hpp"
42 #include "utilities/preserveException.hpp"
43
44 #define __ Disassembler::hook<MacroAssembler>(__FILE__, __LINE__, _masm)->
45
46 #ifdef PRODUCT
47 #define BLOCK_COMMENT(str) /* nothing */
48 #define STOP(error) stop(error)
49 #else
50 #define BLOCK_COMMENT(str) __ block_comment(str)
51 #define STOP(error) block_comment(error); __ stop(error)
52 #endif
53
54 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
55
56 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {
57 if (VerifyMethodHandles)
58 verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class),
59 "MH argument is a Class");
60 __ movptr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset()));
61 }
62
63 #ifdef ASSERT
64 static int check_nonzero(const char* xname, int x) {
65 assert(x != 0, "%s should be nonzero", xname);
66 return x;
67 }
68 #define NONZERO(x) check_nonzero(#x, x)
69 #else //ASSERT
70 #define NONZERO(x) (x)
71 #endif //ASSERT
72
73 #ifdef ASSERT
74 void MethodHandles::verify_klass(MacroAssembler* _masm,
75 Register obj, vmClassID klass_id,
76 const char* error_message) {
77 InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id);
78 Klass* klass = vmClasses::klass_at(klass_id);
79 Register temp = rdi;
80 Label L_ok, L_bad;
81 BLOCK_COMMENT("verify_klass {");
82 __ verify_oop(obj);
83 __ testptr(obj, obj);
84 __ jcc(Assembler::zero, L_bad);
85 #define PUSH { __ push(temp); LP64_ONLY( __ push(rscratch1); ) }
86 #define POP { LP64_ONLY( __ pop(rscratch1); ) __ pop(temp); }
87 PUSH;
88 __ load_klass(temp, obj, rscratch1);
89 __ cmpptr(temp, ExternalAddress((address) klass_addr), rscratch1);
90 __ jcc(Assembler::equal, L_ok);
91 intptr_t super_check_offset = klass->super_check_offset();
92 __ movptr(temp, Address(temp, super_check_offset));
93 __ cmpptr(temp, ExternalAddress((address) klass_addr), rscratch1);
94 __ jcc(Assembler::equal, L_ok);
95 POP;
96 __ bind(L_bad);
97 __ STOP(error_message);
98 __ BIND(L_ok);
99 POP;
100 BLOCK_COMMENT("} verify_klass");
101 #undef POP
102 #undef PUSH
103 }
104
105 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
106 Label L;
107 BLOCK_COMMENT("verify_ref_kind {");
108 __ movl(temp, Address(member_reg, NONZERO(java_lang_invoke_MemberName::flags_offset())));
109 __ shrl(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
110 __ andl(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
111 __ cmpl(temp, ref_kind);
112 __ jcc(Assembler::equal, L);
113 { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
114 jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
115 if (ref_kind == JVM_REF_invokeVirtual ||
116 ref_kind == JVM_REF_invokeSpecial)
117 // could do this for all ref_kinds, but would explode assembly code size
118 trace_method_handle(_masm, buf);
119 __ STOP(buf);
120 }
121 BLOCK_COMMENT("} verify_ref_kind");
122 __ bind(L);
123 }
124
125 #endif //ASSERT
126
127 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
128 bool for_compiler_entry) {
129 assert(method == rbx, "interpreter calling convention");
130
131 Label L_no_such_method;
132 __ testptr(rbx, rbx);
133 __ jcc(Assembler::zero, L_no_such_method);
134
135 __ verify_method_ptr(method);
136
137 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
138 Label run_compiled_code;
139 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
140 // compiled code in threads for which the event is enabled. Check here for
141 // interp_only_mode if these events CAN be enabled.
142 #ifdef _LP64
143 Register rthread = r15_thread;
144 #else
145 Register rthread = temp;
146 __ get_thread(rthread);
147 #endif
148 // interp_only is an int, on little endian it is sufficient to test the byte only
149 // Is a cmpl faster?
150 __ cmpb(Address(rthread, JavaThread::interp_only_mode_offset()), 0);
151 __ jccb(Assembler::zero, run_compiled_code);
152 __ jmp(Address(method, Method::interpreter_entry_offset()));
153 __ BIND(run_compiled_code);
154 }
155
156 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
157 Method::from_interpreted_offset();
158 __ jmp(Address(method, entry_offset));
159
160 __ bind(L_no_such_method);
161 __ jump(RuntimeAddress(SharedRuntime::throw_AbstractMethodError_entry()));
162 }
163
164 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
165 Register recv, Register method_temp,
166 Register temp2,
167 bool for_compiler_entry) {
168 BLOCK_COMMENT("jump_to_lambda_form {");
169 // This is the initial entry point of a lazy method handle.
170 // After type checking, it picks up the invoker from the LambdaForm.
171 assert_different_registers(recv, method_temp, temp2);
172 assert(recv != noreg, "required register");
173 assert(method_temp == rbx, "required register for loading method");
174
175 // Load the invoker, as MH -> MH.form -> LF.vmentry
176 __ verify_oop(recv);
177 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2);
178 __ verify_oop(method_temp);
179 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2);
180 __ verify_oop(method_temp);
181 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2);
182 __ verify_oop(method_temp);
183 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp,
184 Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())),
185 noreg, noreg);
186
187 if (VerifyMethodHandles && !for_compiler_entry) {
188 // make sure recv is already on stack
189 __ movptr(temp2, Address(method_temp, Method::const_offset()));
190 __ load_sized_value(temp2,
191 Address(temp2, ConstMethod::size_of_parameters_offset()),
192 sizeof(u2), /*is_signed*/ false);
193 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
194 Label L;
195 __ cmpoop(recv, __ argument_address(temp2, -1));
196 __ jcc(Assembler::equal, L);
197 __ movptr(rax, __ argument_address(temp2, -1));
198 __ STOP("receiver not on stack");
199 __ BIND(L);
200 }
201
202 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
203 BLOCK_COMMENT("} jump_to_lambda_form");
204 }
205
206 void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) {
207 BLOCK_COMMENT("jump_to_native_invoker {");
208 assert_different_registers(nep_reg, temp_target);
209 assert(nep_reg != noreg, "required register");
210
211 // Load the invoker, as NEP -> .invoker
212 __ verify_oop(nep_reg);
213 __ access_load_at(T_ADDRESS, IN_HEAP, temp_target,
214 Address(nep_reg, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes())),
215 noreg, noreg);
216
217 __ jmp(temp_target);
218 BLOCK_COMMENT("} jump_to_native_invoker");
219 }
220
221
222 // Code generation
223 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
224 vmIntrinsics::ID iid) {
225 const bool not_for_compiler_entry = false; // this is the interpreter entry
226 assert(is_signature_polymorphic(iid), "expected invoke iid");
227 if (iid == vmIntrinsics::_invokeGeneric ||
228 iid == vmIntrinsics::_compiledLambdaForm) {
229 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
230 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
231 // They all allow an appendix argument.
232 __ hlt(); // empty stubs make SG sick
233 return nullptr;
234 }
235
236 // No need in interpreter entry for linkToNative for now.
237 // Interpreter calls compiled entry through i2c.
238 if (iid == vmIntrinsics::_linkToNative) {
239 __ hlt();
240 return nullptr;
241 }
242
243 // rsi/r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)
244 // rbx: Method*
245 // rdx: argument locator (parameter slot count, added to rsp)
246 // rcx: used as temp to hold mh or receiver
247 // rax, rdi: garbage temps, blown away
248 Register rdx_argp = rdx; // argument list ptr, live on error paths
249 Register rax_temp = rax;
250 Register rcx_mh = rcx; // MH receiver; dies quickly and is recycled
251 Register rbx_method = rbx; // eventual target of this invocation
252
253 // here's where control starts out:
254 __ align(CodeEntryAlignment);
255 address entry_point = __ pc();
256
257 if (VerifyMethodHandles) {
258 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
259
260 Label L;
261 BLOCK_COMMENT("verify_intrinsic_id {");
262 __ cmpw(Address(rbx_method, Method::intrinsic_id_offset()), (int) iid);
263 __ jcc(Assembler::equal, L);
264 if (iid == vmIntrinsics::_linkToVirtual ||
265 iid == vmIntrinsics::_linkToSpecial) {
266 // could do this for all kinds, but would explode assembly code size
267 trace_method_handle(_masm, "bad Method*::intrinsic_id");
268 }
269 __ STOP("bad Method*::intrinsic_id");
270 __ bind(L);
271 BLOCK_COMMENT("} verify_intrinsic_id");
272 }
273
274 // First task: Find out how big the argument list is.
275 Address rdx_first_arg_addr;
276 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
277 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
278 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
279 __ movptr(rdx_argp, Address(rbx_method, Method::const_offset()));
280 __ load_sized_value(rdx_argp,
281 Address(rdx_argp, ConstMethod::size_of_parameters_offset()),
282 sizeof(u2), /*is_signed*/ false);
283 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
284 rdx_first_arg_addr = __ argument_address(rdx_argp, -1);
285 } else {
286 DEBUG_ONLY(rdx_argp = noreg);
287 }
288
289 if (!is_signature_polymorphic_static(iid)) {
290 __ movptr(rcx_mh, rdx_first_arg_addr);
291 DEBUG_ONLY(rdx_argp = noreg);
292 }
293
294 // rdx_first_arg_addr is live!
295
296 trace_method_handle_interpreter_entry(_masm, iid);
297
298 if (iid == vmIntrinsics::_invokeBasic) {
299 generate_method_handle_dispatch(_masm, iid, rcx_mh, noreg, not_for_compiler_entry);
300
301 } else {
302 // Adjust argument list by popping the trailing MemberName argument.
303 Register rcx_recv = noreg;
304 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
305 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
306 __ movptr(rcx_recv = rcx, rdx_first_arg_addr);
307 }
308 DEBUG_ONLY(rdx_argp = noreg);
309 Register rbx_member = rbx_method; // MemberName ptr; incoming method ptr is dead now
310 __ pop(rax_temp); // return address
311 __ pop(rbx_member); // extract last argument
312 __ push(rax_temp); // re-push return address
313 generate_method_handle_dispatch(_masm, iid, rcx_recv, rbx_member, not_for_compiler_entry);
314 }
315
316 return entry_point;
317 }
318
319 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
320 vmIntrinsics::ID iid,
321 Register receiver_reg,
322 Register member_reg,
323 bool for_compiler_entry) {
324 assert(is_signature_polymorphic(iid), "expected invoke iid");
325 Register rbx_method = rbx; // eventual target of this invocation
326 // temps used in this code are not used in *either* compiled or interpreted calling sequences
327 #ifdef _LP64
328 Register temp1 = rscratch1;
329 Register temp2 = rscratch2;
330 Register temp3 = rax;
331 if (for_compiler_entry) {
332 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment");
333 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
334 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
335 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
336 }
337 #else
338 Register temp1 = (for_compiler_entry ? rsi : rdx);
339 Register temp2 = rdi;
340 Register temp3 = rax;
341 if (for_compiler_entry) {
342 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : rcx), "only valid assignment");
343 assert_different_registers(temp1, rcx, rdx);
344 assert_different_registers(temp2, rcx, rdx);
345 assert_different_registers(temp3, rcx, rdx);
346 }
347 #endif
348 else {
349 assert_different_registers(temp1, temp2, temp3, saved_last_sp_register()); // don't trash lastSP
350 }
351 assert_different_registers(temp1, temp2, temp3, receiver_reg);
352 assert_different_registers(temp1, temp2, temp3, member_reg);
353
354 if (iid == vmIntrinsics::_invokeBasic) {
355 // indirect through MH.form.vmentry.vmtarget
356 jump_to_lambda_form(_masm, receiver_reg, rbx_method, temp1, for_compiler_entry);
357 } else if (iid == vmIntrinsics::_linkToNative) {
358 assert(for_compiler_entry, "only compiler entry is supported");
359 jump_to_native_invoker(_masm, member_reg, temp1);
360 } else {
361 // The method is a member invoker used by direct method handles.
362 if (VerifyMethodHandles) {
363 // make sure the trailing argument really is a MemberName (caller responsibility)
364 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
365 "MemberName required for invokeVirtual etc.");
366 }
367
368 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
369 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
370 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
371 Address vmtarget_method( rbx_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
372
373 Register temp1_recv_klass = temp1;
374 if (iid != vmIntrinsics::_linkToStatic) {
375 __ verify_oop(receiver_reg);
376 if (iid == vmIntrinsics::_linkToSpecial) {
377 // Don't actually load the klass; just null-check the receiver.
378 __ null_check(receiver_reg);
379 } else {
380 // load receiver klass itself
381 __ load_klass(temp1_recv_klass, receiver_reg, temp2);
382 __ verify_klass_ptr(temp1_recv_klass);
383 }
384 BLOCK_COMMENT("check_receiver {");
385 // The receiver for the MemberName must be in receiver_reg.
386 // Check the receiver against the MemberName.clazz
387 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
388 // Did not load it above...
389 __ load_klass(temp1_recv_klass, receiver_reg, temp2);
390 __ verify_klass_ptr(temp1_recv_klass);
391 }
392 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
393 Label L_ok;
394 Register temp2_defc = temp2;
395 __ load_heap_oop(temp2_defc, member_clazz, temp3);
396 load_klass_from_Class(_masm, temp2_defc);
397 __ verify_klass_ptr(temp2_defc);
398 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
399 // If we get here, the type check failed!
400 __ STOP("receiver class disagrees with MemberName.clazz");
401 __ bind(L_ok);
402 }
403 BLOCK_COMMENT("} check_receiver");
404 }
405 if (iid == vmIntrinsics::_linkToSpecial ||
406 iid == vmIntrinsics::_linkToStatic) {
407 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
408 }
409
410 // Live registers at this point:
411 // member_reg - MemberName that was the trailing argument
412 // temp1_recv_klass - klass of stacked receiver, if needed
413 // rsi/r13 - interpreter linkage (if interpreted)
414 // rcx, rdx, rsi, rdi, r8 - compiler arguments (if compiled)
415
416 Label L_incompatible_class_change_error;
417 switch (iid) {
418 case vmIntrinsics::_linkToSpecial:
419 if (VerifyMethodHandles) {
420 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
421 }
422 __ load_heap_oop(rbx_method, member_vmtarget);
423 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_method, vmtarget_method, noreg, noreg);
424 break;
425
426 case vmIntrinsics::_linkToStatic:
427 if (VerifyMethodHandles) {
428 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
429 }
430 __ load_heap_oop(rbx_method, member_vmtarget);
431 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_method, vmtarget_method, noreg, noreg);
432 break;
433
434 case vmIntrinsics::_linkToVirtual:
435 {
436 // same as TemplateTable::invokevirtual,
437 // minus the CP setup and profiling:
438
439 if (VerifyMethodHandles) {
440 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
441 }
442
443 // pick out the vtable index from the MemberName, and then we can discard it:
444 Register temp2_index = temp2;
445 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
446
447 if (VerifyMethodHandles) {
448 Label L_index_ok;
449 __ cmpl(temp2_index, 0);
450 __ jcc(Assembler::greaterEqual, L_index_ok);
451 __ STOP("no virtual index");
452 __ BIND(L_index_ok);
453 }
454
455 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
456 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
457
458 // get target Method* & entry point
459 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rbx_method);
460 break;
461 }
462
463 case vmIntrinsics::_linkToInterface:
464 {
465 // same as TemplateTable::invokeinterface
466 // (minus the CP setup and profiling, with different argument motion)
467 if (VerifyMethodHandles) {
468 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
469 }
470
471 Register temp3_intf = temp3;
472 __ load_heap_oop(temp3_intf, member_clazz);
473 load_klass_from_Class(_masm, temp3_intf);
474 __ verify_klass_ptr(temp3_intf);
475
476 Register rbx_index = rbx_method;
477 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_index, member_vmindex, noreg, noreg);
478 if (VerifyMethodHandles) {
479 Label L;
480 __ cmpl(rbx_index, 0);
481 __ jcc(Assembler::greaterEqual, L);
482 __ STOP("invalid vtable index for MH.invokeInterface");
483 __ bind(L);
484 }
485
486 // given intf, index, and recv klass, dispatch to the implementation method
487 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
488 // note: next two args must be the same:
489 rbx_index, rbx_method,
490 temp2,
491 L_incompatible_class_change_error);
492 break;
493 }
494
495 default:
496 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
497 break;
498 }
499
500 // Live at this point:
501 // rbx_method
502 // rsi/r13 (if interpreted)
503
504 // After figuring out which concrete method to call, jump into it.
505 // Note that this works in the interpreter with no data motion.
506 // But the compiled version will require that rcx_recv be shifted out.
507 __ verify_method_ptr(rbx_method);
508 jump_from_method_handle(_masm, rbx_method, temp1, for_compiler_entry);
509
510 if (iid == vmIntrinsics::_linkToInterface) {
511 __ bind(L_incompatible_class_change_error);
512 __ jump(RuntimeAddress(SharedRuntime::throw_IncompatibleClassChangeError_entry()));
513 }
514 }
515 }
516
517 #ifndef PRODUCT
518 void trace_method_handle_stub(const char* adaptername,
519 oopDesc* mh,
520 intptr_t* saved_regs,
521 intptr_t* entry_sp) {
522 // called as a leaf from native code: do not block the JVM!
523 bool has_mh = (strstr(adaptername, "/static") == nullptr &&
524 strstr(adaptername, "linkTo") == nullptr); // static linkers don't have MH
525 const char* mh_reg_name = has_mh ? "rcx_mh" : "rcx";
526 log_info(methodhandles)("MH %s %s=" PTR_FORMAT " sp=" PTR_FORMAT, adaptername, mh_reg_name, p2i(mh), p2i(entry_sp));
527
528 LogTarget(Trace, methodhandles) lt;
529 if (lt.is_enabled()) {
530 ResourceMark rm;
531 LogStream ls(lt);
532 ls.print_cr("Registers:");
533 const int saved_regs_count = Register::number_of_registers;
534 for (int i = 0; i < saved_regs_count; i++) {
535 Register r = as_Register(i);
536 // The registers are stored in reverse order on the stack (by pusha).
537 #ifdef AMD64
538 int num_regs = UseAPX ? 32 : 16;
539 assert(Register::available_gp_registers() == num_regs, "sanity");
540 if (r == rsp) {
541 // rsp is actually not stored by pusha(), compute the old rsp from saved_regs (rsp after pusha): saved_regs + 16 = old rsp
542 ls.print("%3s=" PTR_FORMAT, r->name(), (intptr_t)(&saved_regs[num_regs]));
543 } else {
544 ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[((saved_regs_count - 1) - i)]);
545 }
546 #else
547 ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[((saved_regs_count - 1) - i)]);
548 #endif
549 if ((i + 1) % 4 == 0) {
550 ls.cr();
551 } else {
552 ls.print(", ");
553 }
554 }
555 ls.cr();
556
557 // Note: We want to allow trace_method_handle from any call site.
558 // While trace_method_handle creates a frame, it may be entered
559 // without a PC on the stack top (e.g. not just after a call).
560 // Walking that frame could lead to failures due to that invalid PC.
561 // => carefully detect that frame when doing the stack walking
562
563 {
564 // dumping last frame with frame::describe
565
566 JavaThread* p = JavaThread::active();
567
568 // may not be needed by safer and unexpensive here
569 PreserveExceptionMark pem(Thread::current());
570 FrameValues values;
571
572 frame cur_frame = os::current_frame();
573
574 if (cur_frame.fp() != nullptr) { // not walkable
575
576 // Robust search of trace_calling_frame (independent of inlining).
577 // Assumes saved_regs comes from a pusha in the trace_calling_frame.
578 //
579 // We have to start the search from cur_frame, because trace_calling_frame may be it.
580 // It is guaranteed that trace_calling_frame is different from the top frame.
581 // But os::current_frame() does NOT return the top frame: it returns the next frame under it (caller's frame).
582 // (Due to inlining and tail call optimizations, caller's frame doesn't necessarily correspond to the immediate
583 // caller in the source code.)
584 assert(cur_frame.sp() < saved_regs, "registers not saved on stack ?");
585 frame trace_calling_frame = cur_frame;
586 while (trace_calling_frame.fp() < saved_regs) {
587 assert(trace_calling_frame.cb() == nullptr, "not a C frame");
588 trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame);
589 }
590 assert(trace_calling_frame.sp() < saved_regs, "wrong frame");
591
592 // safely create a frame and call frame::describe
593 intptr_t *dump_sp = trace_calling_frame.sender_sp();
594 intptr_t *dump_fp = trace_calling_frame.link();
595
596 if (has_mh) {
597 // The previous definition of walkable may have to be refined
598 // if new call sites cause the next frame constructor to start
599 // failing. Alternatively, frame constructors could be
600 // modified to support the current or future non walkable
601 // frames (but this is more intrusive and is not considered as
602 // part of this RFE, which will instead use a simpler output).
603 frame dump_frame = frame(dump_sp, dump_fp);
604 dump_frame.describe(values, 1);
605 } else {
606 // Stack may not be walkable (invalid PC above FP):
607 // Add descriptions without building a Java frame to avoid issues
608 values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>");
609 values.describe(-1, dump_sp, "sp for #1");
610 }
611 }
612 values.describe(-1, entry_sp, "raw top of stack");
613
614 ls.print_cr("Stack layout:");
615 values.print_on(p, &ls);
616 }
617 if (has_mh && oopDesc::is_oop(mh)) {
618 mh->print_on(&ls);
619 if (java_lang_invoke_MethodHandle::is_instance(mh)) {
620 java_lang_invoke_MethodHandle::form(mh)->print_on(&ls);
621 }
622 }
623 }
624 }
625
626 // The stub wraps the arguments in a struct on the stack to avoid
627 // dealing with the different calling conventions for passing 6
628 // arguments.
629 struct MethodHandleStubArguments {
630 const char* adaptername;
631 oopDesc* mh;
632 intptr_t* saved_regs;
633 intptr_t* entry_sp;
634 };
635 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) {
636 trace_method_handle_stub(args->adaptername,
637 args->mh,
638 args->saved_regs,
639 args->entry_sp);
640 }
641
642 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
643 if (!log_is_enabled(Info, methodhandles)) return;
644 BLOCK_COMMENT(err_msg("trace_method_handle %s {", adaptername));
645 __ enter();
646 __ andptr(rsp, -16); // align stack if needed for FPU state
647 __ pusha();
648 __ mov(rbx, rsp); // for retrieving saved_regs
649 // Note: saved_regs must be in the entered frame for the
650 // robust stack walking implemented in trace_method_handle_stub.
651
652 // save FP result, valid at some call sites (adapter_opt_return_float, ...)
653 __ decrement(rsp, 2 * wordSize);
654 #ifdef _LP64
655 __ movdbl(Address(rsp, 0), xmm0);
656 #else
657 if (UseSSE >= 2) {
658 __ movdbl(Address(rsp, 0), xmm0);
659 } else if (UseSSE == 1) {
660 __ movflt(Address(rsp, 0), xmm0);
661 } else {
662 __ fst_d(Address(rsp, 0));
663 }
664 #endif // LP64
665
666 // Incoming state:
667 // rcx: method handle
668 //
669 // To avoid calling convention issues, build a record on the stack
670 // and pass the pointer to that instead.
671 __ push(rbp); // entry_sp (with extra align space)
672 __ push(rbx); // pusha saved_regs
673 __ push(rcx); // mh
674 __ push(rcx); // slot for adaptername
675 __ movptr(Address(rsp, 0), (intptr_t) adaptername, rscratch1);
676 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub_wrapper), rsp);
677 __ increment(rsp, sizeof(MethodHandleStubArguments));
678
679 #ifdef _LP64
680 __ movdbl(xmm0, Address(rsp, 0));
681 #else
682 if (UseSSE >= 2) {
683 __ movdbl(xmm0, Address(rsp, 0));
684 } else if (UseSSE == 1) {
685 __ movflt(xmm0, Address(rsp, 0));
686 } else {
687 __ fld_d(Address(rsp, 0));
688 }
689 #endif // LP64
690 __ increment(rsp, 2 * wordSize);
691
692 __ popa();
693 __ leave();
694 BLOCK_COMMENT("} trace_method_handle");
695 }
696 #endif //PRODUCT