1 /*
2 * Copyright (c) 1997, 2021, 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/vmClasses.hpp"
29 #include "compiler/disassembler.hpp"
30 #include "classfile/javaClasses.inline.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "interpreter/interpreterRuntime.hpp"
33 #include "logging/log.hpp"
34 #include "logging/logStream.hpp"
35 #include "memory/allocation.inline.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "prims/jvmtiExport.hpp"
38 #include "prims/methodHandles.hpp"
39 #include "runtime/flags/flagSetting.hpp"
40 #include "runtime/frame.inline.hpp"
41 #include "runtime/stubRoutines.hpp"
42 #include "utilities/formatBuffer.hpp"
43 #include "utilities/preserveException.hpp"
44
45 #define __ Disassembler::hook<MacroAssembler>(__FILE__, __LINE__, _masm)->
46
47 #ifdef PRODUCT
48 #define BLOCK_COMMENT(str) /* nothing */
49 #define STOP(error) stop(error)
50 #else
51 #define BLOCK_COMMENT(str) __ block_comment(str)
52 #define STOP(error) block_comment(error); __ stop(error)
53 #endif
54
55 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
56
57 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {
58 if (VerifyMethodHandles)
59 verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class),
60 "MH argument is a Class");
61 __ movptr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset()));
62 }
63
64 #ifdef ASSERT
65 static int check_nonzero(const char* xname, int x) {
66 assert(x != 0, "%s should be nonzero", xname);
67 return x;
68 }
69 #define NONZERO(x) check_nonzero(#x, x)
70 #else //ASSERT
71 #define NONZERO(x) (x)
72 #endif //ASSERT
73
74 #ifdef ASSERT
75 void MethodHandles::verify_klass(MacroAssembler* _masm,
76 Register obj, vmClassID klass_id,
77 const char* error_message) {
78 InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id);
79 Klass* klass = vmClasses::klass_at(klass_id);
80 Register temp = rdi;
81 Register temp2 = noreg;
82 LP64_ONLY(temp2 = rscratch1); // used by MacroAssembler::cmpptr and load_klass
83 Label L_ok, L_bad;
84 BLOCK_COMMENT("verify_klass {");
85 __ verify_oop(obj);
86 __ testptr(obj, obj);
87 __ jcc(Assembler::zero, L_bad);
88 __ push(temp); if (temp2 != noreg) __ push(temp2);
89 #define UNPUSH { if (temp2 != noreg) __ pop(temp2); __ pop(temp); }
90 __ load_klass(temp, obj, temp2);
91 __ cmpptr(temp, ExternalAddress((address) klass_addr));
92 __ jcc(Assembler::equal, L_ok);
93 intptr_t super_check_offset = klass->super_check_offset();
94 __ movptr(temp, Address(temp, super_check_offset));
95 __ cmpptr(temp, ExternalAddress((address) klass_addr));
96 __ jcc(Assembler::equal, L_ok);
97 UNPUSH;
98 __ bind(L_bad);
99 __ STOP(error_message);
100 __ BIND(L_ok);
101 UNPUSH;
102 BLOCK_COMMENT("} verify_klass");
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(StubRoutines::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
207 // Code generation
208 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
209 vmIntrinsics::ID iid) {
210 const bool not_for_compiler_entry = false; // this is the interpreter entry
211 assert(is_signature_polymorphic(iid), "expected invoke iid");
212 if (iid == vmIntrinsics::_invokeGeneric ||
213 iid == vmIntrinsics::_compiledLambdaForm) {
214 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
215 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
216 // They all allow an appendix argument.
217 __ hlt(); // empty stubs make SG sick
218 return NULL;
219 }
220
221 // No need in interpreter entry for linkToNative for now.
222 // Interpreter calls compiled entry through i2c.
223 if (iid == vmIntrinsics::_linkToNative) {
224 __ hlt();
225 return NULL;
226 }
227
228 // rsi/r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)
229 // rbx: Method*
230 // rdx: argument locator (parameter slot count, added to rsp)
231 // rcx: used as temp to hold mh or receiver
232 // rax, rdi: garbage temps, blown away
233 Register rdx_argp = rdx; // argument list ptr, live on error paths
234 Register rax_temp = rax;
235 Register rcx_mh = rcx; // MH receiver; dies quickly and is recycled
236 Register rbx_method = rbx; // eventual target of this invocation
237
238 // here's where control starts out:
239 __ align(CodeEntryAlignment);
240 address entry_point = __ pc();
241
242 if (VerifyMethodHandles) {
243 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
244
245 Label L;
246 BLOCK_COMMENT("verify_intrinsic_id {");
247 __ cmpw(Address(rbx_method, Method::intrinsic_id_offset_in_bytes()), (int) iid);
248 __ jcc(Assembler::equal, L);
249 if (iid == vmIntrinsics::_linkToVirtual ||
250 iid == vmIntrinsics::_linkToSpecial) {
251 // could do this for all kinds, but would explode assembly code size
252 trace_method_handle(_masm, "bad Method*::intrinsic_id");
253 }
254 __ STOP("bad Method*::intrinsic_id");
255 __ bind(L);
256 BLOCK_COMMENT("} verify_intrinsic_id");
257 }
258
259 // First task: Find out how big the argument list is.
260 Address rdx_first_arg_addr;
261 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
262 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
263 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
264 __ movptr(rdx_argp, Address(rbx_method, Method::const_offset()));
265 __ load_sized_value(rdx_argp,
266 Address(rdx_argp, ConstMethod::size_of_parameters_offset()),
267 sizeof(u2), /*is_signed*/ false);
268 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
269 rdx_first_arg_addr = __ argument_address(rdx_argp, -1);
270 } else {
271 DEBUG_ONLY(rdx_argp = noreg);
272 }
273
274 if (!is_signature_polymorphic_static(iid)) {
275 __ movptr(rcx_mh, rdx_first_arg_addr);
276 DEBUG_ONLY(rdx_argp = noreg);
277 }
278
279 // rdx_first_arg_addr is live!
280
281 trace_method_handle_interpreter_entry(_masm, iid);
282
283 if (iid == vmIntrinsics::_invokeBasic) {
284 generate_method_handle_dispatch(_masm, iid, rcx_mh, noreg, not_for_compiler_entry);
285
286 } else {
287 // Adjust argument list by popping the trailing MemberName argument.
288 Register rcx_recv = noreg;
289 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
290 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
291 __ movptr(rcx_recv = rcx, rdx_first_arg_addr);
292 }
293 DEBUG_ONLY(rdx_argp = noreg);
294 Register rbx_member = rbx_method; // MemberName ptr; incoming method ptr is dead now
295 __ pop(rax_temp); // return address
296 __ pop(rbx_member); // extract last argument
297 __ push(rax_temp); // re-push return address
298 generate_method_handle_dispatch(_masm, iid, rcx_recv, rbx_member, not_for_compiler_entry);
299 }
300
301 return entry_point;
302 }
303
304 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
305 vmIntrinsics::ID iid,
306 Register receiver_reg,
307 Register member_reg,
308 bool for_compiler_entry) {
309 assert(is_signature_polymorphic(iid), "expected invoke iid");
310 Register rbx_method = rbx; // eventual target of this invocation
311 // temps used in this code are not used in *either* compiled or interpreted calling sequences
312 #ifdef _LP64
313 Register temp1 = rscratch1;
314 Register temp2 = rscratch2;
315 Register temp3 = rax;
316 if (for_compiler_entry) {
317 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : j_rarg0), "only valid assignment");
318 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
319 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
320 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5);
321 }
322 #else
323 Register temp1 = (for_compiler_entry ? rsi : rdx);
324 Register temp2 = rdi;
325 Register temp3 = rax;
326 if (for_compiler_entry) {
327 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : rcx), "only valid assignment");
328 assert_different_registers(temp1, rcx, rdx);
329 assert_different_registers(temp2, rcx, rdx);
330 assert_different_registers(temp3, rcx, rdx);
331 }
332 #endif
333 else {
334 assert_different_registers(temp1, temp2, temp3, saved_last_sp_register()); // don't trash lastSP
335 }
336 assert_different_registers(temp1, temp2, temp3, receiver_reg);
337 assert_different_registers(temp1, temp2, temp3, member_reg);
338
339 if (iid == vmIntrinsics::_invokeBasic || iid == vmIntrinsics::_linkToNative) {
340 if (iid == vmIntrinsics::_linkToNative) {
341 assert(for_compiler_entry, "only compiler entry is supported");
342 }
343 // indirect through MH.form.vmentry.vmtarget
344 jump_to_lambda_form(_masm, receiver_reg, rbx_method, temp1, for_compiler_entry);
345
346 } else {
347 // The method is a member invoker used by direct method handles.
348 if (VerifyMethodHandles) {
349 // make sure the trailing argument really is a MemberName (caller responsibility)
350 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
351 "MemberName required for invokeVirtual etc.");
352 }
353
354 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
355 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
356 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
357 Address vmtarget_method( rbx_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
358
359 Register temp1_recv_klass = temp1;
360 if (iid != vmIntrinsics::_linkToStatic) {
361 __ verify_oop(receiver_reg);
362 if (iid == vmIntrinsics::_linkToSpecial) {
363 // Don't actually load the klass; just null-check the receiver.
364 __ null_check(receiver_reg);
365 } else {
366 // load receiver klass itself
367 __ null_check(receiver_reg, oopDesc::klass_offset_in_bytes());
368 __ load_klass(temp1_recv_klass, receiver_reg, temp2);
369 __ verify_klass_ptr(temp1_recv_klass);
370 }
371 BLOCK_COMMENT("check_receiver {");
372 // The receiver for the MemberName must be in receiver_reg.
373 // Check the receiver against the MemberName.clazz
374 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
375 // Did not load it above...
376 __ load_klass(temp1_recv_klass, receiver_reg, temp2);
377 __ verify_klass_ptr(temp1_recv_klass);
378 }
379 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
380 Label L_ok;
381 Register temp2_defc = temp2;
382 __ load_heap_oop(temp2_defc, member_clazz, temp3);
383 load_klass_from_Class(_masm, temp2_defc);
384 __ verify_klass_ptr(temp2_defc);
385 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
386 // If we get here, the type check failed!
387 __ STOP("receiver class disagrees with MemberName.clazz");
388 __ bind(L_ok);
389 }
390 BLOCK_COMMENT("} check_receiver");
391 }
392 if (iid == vmIntrinsics::_linkToSpecial ||
393 iid == vmIntrinsics::_linkToStatic) {
394 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
395 }
396
397 // Live registers at this point:
398 // member_reg - MemberName that was the trailing argument
399 // temp1_recv_klass - klass of stacked receiver, if needed
400 // rsi/r13 - interpreter linkage (if interpreted)
401 // rcx, rdx, rsi, rdi, r8 - compiler arguments (if compiled)
402
403 Label L_incompatible_class_change_error;
404 switch (iid) {
405 case vmIntrinsics::_linkToSpecial:
406 if (VerifyMethodHandles) {
407 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
408 }
409 __ load_heap_oop(rbx_method, member_vmtarget);
410 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_method, vmtarget_method, noreg, noreg);
411 break;
412
413 case vmIntrinsics::_linkToStatic:
414 if (VerifyMethodHandles) {
415 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
416 }
417 __ load_heap_oop(rbx_method, member_vmtarget);
418 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_method, vmtarget_method, noreg, noreg);
419 break;
420
421 case vmIntrinsics::_linkToVirtual:
422 {
423 // same as TemplateTable::invokevirtual,
424 // minus the CP setup and profiling:
425
426 if (VerifyMethodHandles) {
427 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
428 }
429
430 // pick out the vtable index from the MemberName, and then we can discard it:
431 Register temp2_index = temp2;
432 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
433
434 if (VerifyMethodHandles) {
435 Label L_index_ok;
436 __ cmpl(temp2_index, 0);
437 __ jcc(Assembler::greaterEqual, L_index_ok);
438 __ STOP("no virtual index");
439 __ BIND(L_index_ok);
440 }
441
442 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
443 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
444
445 // get target Method* & entry point
446 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rbx_method);
447 break;
448 }
449
450 case vmIntrinsics::_linkToInterface:
451 {
452 // same as TemplateTable::invokeinterface
453 // (minus the CP setup and profiling, with different argument motion)
454 if (VerifyMethodHandles) {
455 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
456 }
457
458 Register temp3_intf = temp3;
459 __ load_heap_oop(temp3_intf, member_clazz);
460 load_klass_from_Class(_masm, temp3_intf);
461 __ verify_klass_ptr(temp3_intf);
462
463 Register rbx_index = rbx_method;
464 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_index, member_vmindex, noreg, noreg);
465 if (VerifyMethodHandles) {
466 Label L;
467 __ cmpl(rbx_index, 0);
468 __ jcc(Assembler::greaterEqual, L);
469 __ STOP("invalid vtable index for MH.invokeInterface");
470 __ bind(L);
471 }
472
473 // given intf, index, and recv klass, dispatch to the implementation method
474 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
475 // note: next two args must be the same:
476 rbx_index, rbx_method,
477 temp2,
478 L_incompatible_class_change_error);
479 break;
480 }
481
482 default:
483 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
484 break;
485 }
486
487 // Live at this point:
488 // rbx_method
489 // rsi/r13 (if interpreted)
490
491 // After figuring out which concrete method to call, jump into it.
492 // Note that this works in the interpreter with no data motion.
493 // But the compiled version will require that rcx_recv be shifted out.
494 __ verify_method_ptr(rbx_method);
495 jump_from_method_handle(_masm, rbx_method, temp1, for_compiler_entry);
496
497 if (iid == vmIntrinsics::_linkToInterface) {
498 __ bind(L_incompatible_class_change_error);
499 __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
500 }
501 }
502 }
503
504 #ifndef PRODUCT
505 void trace_method_handle_stub(const char* adaptername,
506 oopDesc* mh,
507 intptr_t* saved_regs,
508 intptr_t* entry_sp) {
509 // called as a leaf from native code: do not block the JVM!
510 bool has_mh = (strstr(adaptername, "/static") == NULL &&
511 strstr(adaptername, "linkTo") == NULL); // static linkers don't have MH
512 const char* mh_reg_name = has_mh ? "rcx_mh" : "rcx";
513 log_info(methodhandles)("MH %s %s=" PTR_FORMAT " sp=" PTR_FORMAT, adaptername, mh_reg_name, p2i(mh), p2i(entry_sp));
514
515 LogTarget(Trace, methodhandles) lt;
516 if (lt.is_enabled()) {
517 ResourceMark rm;
518 LogStream ls(lt);
519 ls.print_cr("Registers:");
520 const int saved_regs_count = RegisterImpl::number_of_registers;
521 for (int i = 0; i < saved_regs_count; i++) {
522 Register r = as_Register(i);
523 // The registers are stored in reverse order on the stack (by pusha).
524 #ifdef AMD64
525 assert(RegisterImpl::number_of_registers == 16, "sanity");
526 if (r == rsp) {
527 // rsp is actually not stored by pusha(), compute the old rsp from saved_regs (rsp after pusha): saved_regs + 16 = old rsp
528 ls.print("%3s=" PTR_FORMAT, r->name(), (intptr_t)(&saved_regs[16]));
529 } else {
530 ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[((saved_regs_count - 1) - i)]);
531 }
532 #else
533 ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[((saved_regs_count - 1) - i)]);
534 #endif
535 if ((i + 1) % 4 == 0) {
536 ls.cr();
537 } else {
538 ls.print(", ");
539 }
540 }
541 ls.cr();
542
543 // Note: We want to allow trace_method_handle from any call site.
544 // While trace_method_handle creates a frame, it may be entered
545 // without a PC on the stack top (e.g. not just after a call).
546 // Walking that frame could lead to failures due to that invalid PC.
547 // => carefully detect that frame when doing the stack walking
548
549 {
550 // dumping last frame with frame::describe
551
552 JavaThread* p = JavaThread::active();
553
554 // may not be needed by safer and unexpensive here
555 PreserveExceptionMark pem(Thread::current());
556 FrameValues values;
557
558 frame cur_frame = os::current_frame();
559
560 if (cur_frame.fp() != 0) { // not walkable
561
562 // Robust search of trace_calling_frame (independent of inlining).
563 // Assumes saved_regs comes from a pusha in the trace_calling_frame.
564 //
565 // We have to start the search from cur_frame, because trace_calling_frame may be it.
566 // It is guaranteed that trace_calling_frame is different from the top frame.
567 // But os::current_frame() does NOT return the top frame: it returns the next frame under it (caller's frame).
568 // (Due to inlining and tail call optimizations, caller's frame doesn't necessarily correspond to the immediate
569 // caller in the source code.)
570 assert(cur_frame.sp() < saved_regs, "registers not saved on stack ?");
571 frame trace_calling_frame = cur_frame;
572 while (trace_calling_frame.fp() < saved_regs) {
573 assert(trace_calling_frame.cb() == NULL, "not a C frame");
574 trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame);
575 }
576 assert(trace_calling_frame.sp() < saved_regs, "wrong frame");
577
578 // safely create a frame and call frame::describe
579 intptr_t *dump_sp = trace_calling_frame.sender_sp();
580 intptr_t *dump_fp = trace_calling_frame.link();
581
582 if (has_mh) {
583 // The previous definition of walkable may have to be refined
584 // if new call sites cause the next frame constructor to start
585 // failing. Alternatively, frame constructors could be
586 // modified to support the current or future non walkable
587 // frames (but this is more intrusive and is not considered as
588 // part of this RFE, which will instead use a simpler output).
589 frame dump_frame = frame(dump_sp, dump_fp);
590 dump_frame.describe(values, 1);
591 } else {
592 // Stack may not be walkable (invalid PC above FP):
593 // Add descriptions without building a Java frame to avoid issues
594 values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>");
595 values.describe(-1, dump_sp, "sp for #1");
596 }
597 }
598 values.describe(-1, entry_sp, "raw top of stack");
599
600 ls.print_cr("Stack layout:");
601 values.print_on(p, &ls);
602 }
603 if (has_mh && oopDesc::is_oop(mh)) {
604 mh->print_on(&ls);
605 if (java_lang_invoke_MethodHandle::is_instance(mh)) {
606 java_lang_invoke_MethodHandle::form(mh)->print_on(&ls);
607 }
608 }
609 }
610 }
611
612 // The stub wraps the arguments in a struct on the stack to avoid
613 // dealing with the different calling conventions for passing 6
614 // arguments.
615 struct MethodHandleStubArguments {
616 const char* adaptername;
617 oopDesc* mh;
618 intptr_t* saved_regs;
619 intptr_t* entry_sp;
620 };
621 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) {
622 trace_method_handle_stub(args->adaptername,
623 args->mh,
624 args->saved_regs,
625 args->entry_sp);
626 }
627
628 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
629 if (!log_is_enabled(Info, methodhandles)) return;
630 BLOCK_COMMENT(err_msg("trace_method_handle %s {", adaptername));
631 __ enter();
632 __ andptr(rsp, -16); // align stack if needed for FPU state
633 __ pusha();
634 __ mov(rbx, rsp); // for retreiving saved_regs
635 // Note: saved_regs must be in the entered frame for the
636 // robust stack walking implemented in trace_method_handle_stub.
637
638 // save FP result, valid at some call sites (adapter_opt_return_float, ...)
639 __ decrement(rsp, 2 * wordSize);
640 #ifdef _LP64
641 __ movdbl(Address(rsp, 0), xmm0);
642 #else
643 if (UseSSE >= 2) {
644 __ movdbl(Address(rsp, 0), xmm0);
645 } else if (UseSSE == 1) {
646 __ movflt(Address(rsp, 0), xmm0);
647 } else {
648 __ fst_d(Address(rsp, 0));
649 }
650 #endif // LP64
651
652 // Incoming state:
653 // rcx: method handle
654 //
655 // To avoid calling convention issues, build a record on the stack
656 // and pass the pointer to that instead.
657 __ push(rbp); // entry_sp (with extra align space)
658 __ push(rbx); // pusha saved_regs
659 __ push(rcx); // mh
660 __ push(rcx); // slot for adaptername
661 __ movptr(Address(rsp, 0), (intptr_t) adaptername);
662 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub_wrapper), rsp);
663 __ increment(rsp, sizeof(MethodHandleStubArguments));
664
665 #ifdef _LP64
666 __ movdbl(xmm0, Address(rsp, 0));
667 #else
668 if (UseSSE >= 2) {
669 __ movdbl(xmm0, Address(rsp, 0));
670 } else if (UseSSE == 1) {
671 __ movflt(xmm0, Address(rsp, 0));
672 } else {
673 __ fld_d(Address(rsp, 0));
674 }
675 #endif // LP64
676 __ increment(rsp, 2 * wordSize);
677
678 __ popa();
679 __ leave();
680 BLOCK_COMMENT("} trace_method_handle");
681 }
682 #endif //PRODUCT