1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, Red Hat Inc. All rights reserved.
4 * Copyright (c) 2020, 2023, Huawei Technologies Co., Ltd. All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #include "asm/macroAssembler.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "classfile/vmClasses.hpp"
30 #include "compiler/disassembler.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "interpreter/interpreterRuntime.hpp"
33 #include "memory/allocation.inline.hpp"
34 #include "prims/jvmtiExport.hpp"
35 #include "prims/methodHandles.hpp"
36 #include "runtime/flags/flagSetting.hpp"
37 #include "runtime/frame.inline.hpp"
38 #include "runtime/stubRoutines.hpp"
39
40 #define __ Disassembler::hook<MacroAssembler>(__FILE__, __LINE__, _masm)->
41
42 #ifdef PRODUCT
43 #define BLOCK_COMMENT(str) /* nothing */
44 #else
45 #define BLOCK_COMMENT(str) __ block_comment(str)
46 #endif
47
48 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
49
50 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {
51 if (VerifyMethodHandles) {
52 verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class),
53 "MH argument is a Class");
54 }
55 __ ld(klass_reg, Address(klass_reg, java_lang_Class::klass_offset()));
56 }
57
58 #ifdef ASSERT
59 static int check_nonzero(const char* xname, int x) {
60 assert(x != 0, "%s should be nonzero", xname);
61 return x;
62 }
63 #define NONZERO(x) check_nonzero(#x, x)
64 #else //ASSERT
65 #define NONZERO(x) (x)
66 #endif //PRODUCT
67
68 #ifdef ASSERT
69 void MethodHandles::verify_klass(MacroAssembler* _masm,
70 Register obj, vmClassID klass_id,
71 const char* error_message) {
72 InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id);
73 Klass* klass = vmClasses::klass_at(klass_id);
74 Register temp1 = t1;
75 Register temp2 = t0;
76 Label L_ok, L_bad;
77 BLOCK_COMMENT("verify_klass {");
78 __ verify_oop(obj);
79 __ beqz(obj, L_bad);
80
81 __ push_reg(RegSet::of(temp1, temp2), sp);
82 __ load_klass(temp1, obj, temp2);
83 __ ld(temp2, ExternalAddress((address)klass_addr));
84 __ beq(temp1, temp2, L_ok);
85
86 intptr_t super_check_offset = klass->super_check_offset();
87 __ ld(temp1, Address(temp1, super_check_offset));
88 __ ld(temp2, ExternalAddress((address)klass_addr));
89 __ beq(temp1, temp2, L_ok);
90
91 __ pop_reg(RegSet::of(temp1, temp2), sp);
92 __ bind(L_bad);
93 __ stop(error_message);
94 __ BIND(L_ok);
95 __ pop_reg(RegSet::of(temp1, temp2), sp);
96 BLOCK_COMMENT("} verify_klass");
97 }
98
99 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {}
100
101 void MethodHandles::verify_method(MacroAssembler* _masm, Register method, vmIntrinsics::ID iid) {
102 BLOCK_COMMENT("verify_method {");
103 __ verify_method_ptr(method);
104 if (VerifyMethodHandles) {
105 Label L_ok;
106 assert_different_registers(method, t0, t1);
107 const Register method_holder = t1;
108 __ load_method_holder(method_holder, method);
109
110 switch (iid) {
111 case vmIntrinsicID::_invokeBasic:
112 // Require compiled LambdaForm class to be fully initialized.
113 __ lbu(t0, Address(method_holder, InstanceKlass::init_state_offset()));
114 __ membar(MacroAssembler::LoadLoad | MacroAssembler::LoadStore);
115 __ mv(t1, InstanceKlass::fully_initialized);
116 __ beq(t0, t1, L_ok);
117 break;
118 case vmIntrinsicID::_linkToStatic:
119 __ clinit_barrier(method_holder, t0, &L_ok);
120 break;
121
122 case vmIntrinsicID::_linkToVirtual:
123 case vmIntrinsicID::_linkToSpecial:
124 case vmIntrinsicID::_linkToInterface:
125 // Class initialization check is too strong here. Just ensure that class initialization has been initiated.
126 __ lbu(t0, Address(method_holder, InstanceKlass::init_state_offset()));
127 __ membar(MacroAssembler::LoadLoad | MacroAssembler::LoadStore);
128 __ mv(t1, InstanceKlass::being_initialized);
129 __ bge(t0, t1, L_ok);
130
131 // init_state check failed, but it may be an abstract interface method
132 __ lhu(t0, Address(method, Method::access_flags_offset()));
133 __ test_bit(t1, t0, exact_log2(JVM_ACC_ABSTRACT));
134 __ bnez(t1, L_ok);
135 break;
136
137 default:
138 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
139 }
140
141 // Method holder init state check failed for a concrete method.
142 __ stop("Method holder klass is not initialized");
143 __ BIND(L_ok);
144 }
145 BLOCK_COMMENT("} verify_method");
146 }
147 #endif //ASSERT
148
149 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
150 bool for_compiler_entry, vmIntrinsics::ID iid) {
151 assert(method == xmethod, "interpreter calling convention");
152 Label L_no_such_method;
153 __ beqz(xmethod, L_no_such_method);
154 verify_method(_masm, method, iid);
155
156 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
157 Label run_compiled_code;
158 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
159 // compiled code in threads for which the event is enabled. Check here for
160 // interp_only_mode if these events CAN be enabled.
161
162 __ lwu(t1, Address(xthread, JavaThread::interp_only_mode_offset()));
163 __ beqz(t1, run_compiled_code);
164 __ ld(t1, Address(method, Method::interpreter_entry_offset()));
165 __ jr(t1);
166 __ BIND(run_compiled_code);
167 }
168
169 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
170 Method::from_interpreted_offset();
171 __ ld(t1, Address(method, entry_offset));
172 __ jr(t1);
173 __ bind(L_no_such_method);
174 __ far_jump(RuntimeAddress(SharedRuntime::throw_AbstractMethodError_entry()));
175 }
176
177 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
178 Register recv, Register method_temp,
179 Register temp2,
180 bool for_compiler_entry) {
181 BLOCK_COMMENT("jump_to_lambda_form {");
182 // This is the initial entry point of a lazy method handle.
183 // After type checking, it picks up the invoker from the LambdaForm.
184 assert_different_registers(recv, method_temp, temp2);
185 assert(recv != noreg, "required register");
186 assert(method_temp == xmethod, "required register for loading method");
187
188 // Load the invoker, as MH -> MH.form -> LF.vmentry
189 __ verify_oop(recv);
190 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2, t1);
191 __ verify_oop(method_temp);
192 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2, t1);
193 __ verify_oop(method_temp);
194 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2, t1);
195 __ verify_oop(method_temp);
196 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), noreg, noreg);
197
198 if (VerifyMethodHandles && !for_compiler_entry) {
199 // make sure recv is already on stack
200 __ ld(temp2, Address(method_temp, Method::const_offset()));
201 __ load_sized_value(temp2,
202 Address(temp2, ConstMethod::size_of_parameters_offset()),
203 sizeof(u2), /*is_signed*/ false);
204 Label L;
205 __ ld(t0, __ argument_address(temp2, -1));
206 __ beq(recv, t0, L);
207 __ ld(x10, __ argument_address(temp2, -1));
208 __ ebreak();
209 __ BIND(L);
210 }
211
212 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry, vmIntrinsics::_invokeBasic);
213 BLOCK_COMMENT("} jump_to_lambda_form");
214 }
215
216 // Code generation
217 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
218 vmIntrinsics::ID iid) {
219 const bool not_for_compiler_entry = false; // this is the interpreter entry
220 assert(is_signature_polymorphic(iid), "expected invoke iid");
221 if (iid == vmIntrinsics::_invokeGeneric ||
222 iid == vmIntrinsics::_compiledLambdaForm) {
223 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
224 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
225 // They all allow an appendix argument.
226 __ ebreak(); // empty stubs make SG sick
227 return nullptr;
228 }
229
230 // No need in interpreter entry for linkToNative for now.
231 // Interpreter calls compiled entry through i2c.
232 if (iid == vmIntrinsics::_linkToNative) {
233 __ ebreak();
234 return nullptr;
235 }
236
237 // x19_sender_sp: sender SP (must preserve; see prepare_to_jump_from_interpreted)
238 // xmethod: Method*
239 // x13: argument locator (parameter slot count, added to sp)
240 // x11: used as temp to hold mh or receiver
241 // x10, x29: garbage temps, blown away
242 Register argp = x13; // argument list ptr, live on error paths
243 Register mh = x11; // MH receiver; dies quickly and is recycled
244
245 // here's where control starts out:
246 __ align(CodeEntryAlignment);
247 address entry_point = __ pc();
248
249 if (VerifyMethodHandles) {
250 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
251
252 Label L;
253 BLOCK_COMMENT("verify_intrinsic_id {");
254 __ lhu(t0, Address(xmethod, Method::intrinsic_id_offset()));
255 __ mv(t1, (int) iid);
256 __ beq(t0, t1, L);
257 if (iid == vmIntrinsics::_linkToVirtual ||
258 iid == vmIntrinsics::_linkToSpecial) {
259 // could do this for all kinds, but would explode assembly code size
260 trace_method_handle(_masm, "bad Method*::intrinsic_id");
261 }
262 __ ebreak();
263 __ bind(L);
264 BLOCK_COMMENT("} verify_intrinsic_id");
265 }
266
267 // First task: Find out how big the argument list is.
268 Address x13_first_arg_addr;
269 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
270 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
271 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
272 __ ld(argp, Address(xmethod, Method::const_offset()));
273 __ load_sized_value(argp,
274 Address(argp, ConstMethod::size_of_parameters_offset()),
275 sizeof(u2), /*is_signed*/ false);
276 x13_first_arg_addr = __ argument_address(argp, -1);
277 } else {
278 DEBUG_ONLY(argp = noreg);
279 }
280
281 if (!is_signature_polymorphic_static(iid)) {
282 __ ld(mh, x13_first_arg_addr);
283 DEBUG_ONLY(argp = noreg);
284 }
285
286 // x13_first_arg_addr is live!
287
288 trace_method_handle_interpreter_entry(_masm, iid);
289 if (iid == vmIntrinsics::_invokeBasic) {
290 generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
291 } else {
292 // Adjust argument list by popping the trailing MemberName argument.
293 Register recv = noreg;
294 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
295 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
296 __ ld(recv = x12, x13_first_arg_addr);
297 }
298 DEBUG_ONLY(argp = noreg);
299 Register xmember = xmethod; // MemberName ptr; incoming method ptr is dead now
300 __ pop_reg(xmember); // extract last argument
301 generate_method_handle_dispatch(_masm, iid, recv, xmember, not_for_compiler_entry);
302 }
303
304 return entry_point;
305 }
306
307 void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) {
308 BLOCK_COMMENT("jump_to_native_invoker {");
309 assert_different_registers(nep_reg, temp_target);
310 assert(nep_reg != noreg, "required register");
311
312 // Load the invoker, as NEP -> .invoker
313 __ verify_oop(nep_reg);
314 __ access_load_at(T_ADDRESS, IN_HEAP, temp_target,
315 Address(nep_reg, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes())),
316 noreg, noreg);
317
318 __ jr(temp_target);
319 BLOCK_COMMENT("} jump_to_native_invoker");
320 }
321
322 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
323 vmIntrinsics::ID iid,
324 Register receiver_reg,
325 Register member_reg,
326 bool for_compiler_entry) {
327 assert(is_signature_polymorphic(iid), "expected invoke iid");
328 // temps used in this code are not used in *either* compiled or interpreted calling sequences
329 Register temp1 = x7;
330 Register temp2 = x28;
331 Register temp3 = x29;
332 if (for_compiler_entry) {
333 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment");
334 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
335 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
336 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
337 }
338
339 assert_different_registers(temp1, temp2, temp3, receiver_reg);
340 assert_different_registers(temp1, temp2, temp3, member_reg);
341
342 if (iid == vmIntrinsics::_invokeBasic) {
343 // indirect through MH.form.vmentry.vmtarget
344 jump_to_lambda_form(_masm, receiver_reg, xmethod, temp1, for_compiler_entry);
345 } else if (iid == vmIntrinsics::_linkToNative) {
346 assert(for_compiler_entry, "only compiler entry is supported");
347 jump_to_native_invoker(_masm, member_reg, temp1);
348 } else {
349 // The method is a member invoker used by direct method handles.
350 if (VerifyMethodHandles) {
351 // make sure the trailing argument really is a MemberName (caller responsibility)
352 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
353 "MemberName required for invokeVirtual etc.");
354 }
355
356 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
357 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
358 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
359 Address vmtarget_method( xmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
360
361 Register temp1_recv_klass = temp1;
362 if (iid != vmIntrinsics::_linkToStatic) {
363 __ verify_oop(receiver_reg);
364 if (iid == vmIntrinsics::_linkToSpecial) {
365 // Don't actually load the klass; just null-check the receiver.
366 __ null_check(receiver_reg);
367 } else {
368 // load receiver klass itself
369 __ load_klass(temp1_recv_klass, receiver_reg);
370 __ verify_klass_ptr(temp1_recv_klass);
371 }
372 BLOCK_COMMENT("check_receiver {");
373 // The receiver for the MemberName must be in receiver_reg.
374 // Check the receiver against the MemberName.clazz
375 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
376 // Did not load it above...
377 __ load_klass(temp1_recv_klass, receiver_reg);
378 __ verify_klass_ptr(temp1_recv_klass);
379 }
380 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
381 Label L_ok;
382 Register temp2_defc = temp2;
383 __ load_heap_oop(temp2_defc, member_clazz, temp3, t1);
384 load_klass_from_Class(_masm, temp2_defc);
385 __ verify_klass_ptr(temp2_defc);
386 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
387 // If we get here, the type check failed!
388 __ ebreak();
389 __ bind(L_ok);
390 }
391 BLOCK_COMMENT("} check_receiver");
392 }
393 if (iid == vmIntrinsics::_linkToSpecial ||
394 iid == vmIntrinsics::_linkToStatic) {
395 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
396 }
397
398 // Live registers at this point:
399 // member_reg - MemberName that was the trailing argument
400 // temp1_recv_klass - klass of stacked receiver, if needed
401 // x19 - interpreter linkage (if interpreted)
402 // x11 ... x10 - compiler arguments (if compiled)
403
404 Label L_incompatible_class_change_error;
405 switch (iid) {
406 case vmIntrinsics::_linkToSpecial:
407 if (VerifyMethodHandles) {
408 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
409 }
410 __ load_heap_oop(xmethod, member_vmtarget, temp3, t1);
411 __ access_load_at(T_ADDRESS, IN_HEAP, xmethod, vmtarget_method, noreg, noreg);
412 break;
413
414 case vmIntrinsics::_linkToStatic:
415 if (VerifyMethodHandles) {
416 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
417 }
418 __ load_heap_oop(xmethod, member_vmtarget, temp3, t1);
419 __ access_load_at(T_ADDRESS, IN_HEAP, xmethod, vmtarget_method, noreg, noreg);
420 break;
421
422 case vmIntrinsics::_linkToVirtual:
423 {
424 // same as TemplateTable::invokevirtual,
425 // minus the CP setup and profiling:
426
427 if (VerifyMethodHandles) {
428 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
429 }
430
431 // pick out the vtable index from the MemberName, and then we can discard it:
432 Register temp2_index = temp2;
433 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
434
435 if (VerifyMethodHandles) {
436 Label L_index_ok;
437 __ bgez(temp2_index, L_index_ok);
438 __ ebreak();
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, xmethod);
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, temp2, t1);
460 load_klass_from_Class(_masm, temp3_intf);
461 __ verify_klass_ptr(temp3_intf);
462
463 Register rindex = xmethod;
464 __ access_load_at(T_ADDRESS, IN_HEAP, rindex, member_vmindex, noreg, noreg);
465 if (VerifyMethodHandles) {
466 Label L;
467 __ bgez(rindex, L);
468 __ ebreak();
469 __ bind(L);
470 }
471
472 // given intf, index, and recv klass, dispatch to the implementation method
473 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
474 // note: next two args must be the same:
475 rindex, xmethod,
476 temp2,
477 L_incompatible_class_change_error);
478 break;
479 }
480
481 default:
482 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
483 break;
484 }
485
486 // live at this point: xmethod, x19_sender_sp (if interpreted)
487
488 // After figuring out which concrete method to call, jump into it.
489 // Note that this works in the interpreter with no data motion.
490 // But the compiled version will require that r2_recv be shifted out.
491 jump_from_method_handle(_masm, xmethod, temp1, for_compiler_entry, iid);
492 if (iid == vmIntrinsics::_linkToInterface) {
493 __ bind(L_incompatible_class_change_error);
494 __ far_jump(RuntimeAddress(SharedRuntime::throw_IncompatibleClassChangeError_entry()));
495 }
496 }
497 }
498
499 #ifndef PRODUCT
500 void trace_method_handle_stub(const char* adaptername,
501 oopDesc* mh,
502 intptr_t* saved_regs,
503 intptr_t* entry_sp) { }
504
505 // The stub wraps the arguments in a struct on the stack to avoid
506 // dealing with the different calling conventions for passing 6
507 // arguments.
508 struct MethodHandleStubArguments {
509 const char* adaptername;
510 oopDesc* mh;
511 intptr_t* saved_regs;
512 intptr_t* entry_sp;
513 };
514 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { }
515
516 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { }
517 #endif //PRODUCT