1 /*
2 * Copyright (c) 1997, 2026, 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 // The following jump might pass an inline type argument that was erased to Object as oop to a
170 // callee that expects inline type arguments to be passed as fields. We need to call the compiled
171 // value entry (_code->inline_entry_point() or _adapter->c2i_inline_entry()) which will take care
172 // of translating between the calling conventions.
173 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_inline_offset() :
174 Method::from_interpreted_offset();
175 __ ld(t1, Address(method, entry_offset));
176 __ jr(t1);
177 __ bind(L_no_such_method);
178 __ far_jump(RuntimeAddress(SharedRuntime::throw_AbstractMethodError_entry()));
179 }
180
181 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
182 Register recv, Register method_temp,
183 Register temp2,
184 bool for_compiler_entry) {
185 BLOCK_COMMENT("jump_to_lambda_form {");
186 // This is the initial entry point of a lazy method handle.
187 // After type checking, it picks up the invoker from the LambdaForm.
188 assert_different_registers(recv, method_temp, temp2);
189 assert(recv != noreg, "required register");
190 assert(method_temp == xmethod, "required register for loading method");
191
192 // Load the invoker, as MH -> MH.form -> LF.vmentry
193 __ verify_oop(recv);
194 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2, t1);
195 __ verify_oop(method_temp);
196 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2, t1);
197 __ verify_oop(method_temp);
198 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2, t1);
199 __ verify_oop(method_temp);
200 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), noreg, noreg);
201
202 if (VerifyMethodHandles && !for_compiler_entry) {
203 // make sure recv is already on stack
204 __ ld(temp2, Address(method_temp, Method::const_offset()));
205 __ load_sized_value(temp2,
206 Address(temp2, ConstMethod::size_of_parameters_offset()),
207 sizeof(u2), /*is_signed*/ false);
208 Label L;
209 __ ld(t0, __ argument_address(temp2, -1));
210 __ beq(recv, t0, L);
211 __ ld(x10, __ argument_address(temp2, -1));
212 __ ebreak();
213 __ BIND(L);
214 }
215
216 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry, vmIntrinsics::_invokeBasic);
217 BLOCK_COMMENT("} jump_to_lambda_form");
218 }
219
220 // Code generation
221 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
222 vmIntrinsics::ID iid) {
223 const bool not_for_compiler_entry = false; // this is the interpreter entry
224 assert(is_signature_polymorphic(iid), "expected invoke iid");
225 if (iid == vmIntrinsics::_invokeGeneric ||
226 iid == vmIntrinsics::_compiledLambdaForm) {
227 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
228 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
229 // They all allow an appendix argument.
230 __ ebreak(); // empty stubs make SG sick
231 return nullptr;
232 }
233
234 // No need in interpreter entry for linkToNative for now.
235 // Interpreter calls compiled entry through i2c.
236 if (iid == vmIntrinsics::_linkToNative) {
237 __ ebreak();
238 return nullptr;
239 }
240
241 // x19_sender_sp: sender SP (must preserve; see prepare_to_jump_from_interpreted)
242 // xmethod: Method*
243 // x13: argument locator (parameter slot count, added to sp)
244 // x11: used as temp to hold mh or receiver
245 // x10, x29: garbage temps, blown away
246 Register argp = x13; // argument list ptr, live on error paths
247 Register mh = x11; // MH receiver; dies quickly and is recycled
248
249 // here's where control starts out:
250 __ align(CodeEntryAlignment);
251 address entry_point = __ pc();
252
253 if (VerifyMethodHandles) {
254 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
255
256 Label L;
257 BLOCK_COMMENT("verify_intrinsic_id {");
258 __ lhu(t0, Address(xmethod, Method::intrinsic_id_offset()));
259 __ mv(t1, (int) iid);
260 __ beq(t0, t1, L);
261 if (iid == vmIntrinsics::_linkToVirtual ||
262 iid == vmIntrinsics::_linkToSpecial) {
263 // could do this for all kinds, but would explode assembly code size
264 trace_method_handle(_masm, "bad Method*::intrinsic_id");
265 }
266 __ ebreak();
267 __ bind(L);
268 BLOCK_COMMENT("} verify_intrinsic_id");
269 }
270
271 // First task: Find out how big the argument list is.
272 Address x13_first_arg_addr;
273 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
274 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
275 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
276 __ ld(argp, Address(xmethod, Method::const_offset()));
277 __ load_sized_value(argp,
278 Address(argp, ConstMethod::size_of_parameters_offset()),
279 sizeof(u2), /*is_signed*/ false);
280 x13_first_arg_addr = __ argument_address(argp, -1);
281 } else {
282 DEBUG_ONLY(argp = noreg);
283 }
284
285 if (!is_signature_polymorphic_static(iid)) {
286 __ ld(mh, x13_first_arg_addr);
287 DEBUG_ONLY(argp = noreg);
288 }
289
290 // x13_first_arg_addr is live!
291
292 trace_method_handle_interpreter_entry(_masm, iid);
293 if (iid == vmIntrinsics::_invokeBasic) {
294 generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
295 } else {
296 // Adjust argument list by popping the trailing MemberName argument.
297 Register recv = noreg;
298 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
299 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
300 __ ld(recv = x12, x13_first_arg_addr);
301 }
302 DEBUG_ONLY(argp = noreg);
303 Register xmember = xmethod; // MemberName ptr; incoming method ptr is dead now
304 __ pop_reg(xmember); // extract last argument
305 generate_method_handle_dispatch(_masm, iid, recv, xmember, not_for_compiler_entry);
306 }
307
308 return entry_point;
309 }
310
311 void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) {
312 BLOCK_COMMENT("jump_to_native_invoker {");
313 assert_different_registers(nep_reg, temp_target);
314 assert(nep_reg != noreg, "required register");
315
316 // Load the invoker, as NEP -> .invoker
317 __ verify_oop(nep_reg);
318 __ access_load_at(T_ADDRESS, IN_HEAP, temp_target,
319 Address(nep_reg, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes())),
320 noreg, noreg);
321
322 __ jr(temp_target);
323 BLOCK_COMMENT("} jump_to_native_invoker");
324 }
325
326 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
327 vmIntrinsics::ID iid,
328 Register receiver_reg,
329 Register member_reg,
330 bool for_compiler_entry) {
331 assert(is_signature_polymorphic(iid), "expected invoke iid");
332 // temps used in this code are not used in *either* compiled or interpreted calling sequences
333 Register temp1 = x7;
334 Register temp2 = x28;
335 Register temp3 = x29;
336 if (for_compiler_entry) {
337 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment");
338 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
339 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
340 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
341 }
342
343 assert_different_registers(temp1, temp2, temp3, receiver_reg);
344 assert_different_registers(temp1, temp2, temp3, member_reg);
345
346 if (iid == vmIntrinsics::_invokeBasic) {
347 // indirect through MH.form.vmentry.vmtarget
348 jump_to_lambda_form(_masm, receiver_reg, xmethod, temp1, for_compiler_entry);
349 } else if (iid == vmIntrinsics::_linkToNative) {
350 assert(for_compiler_entry, "only compiler entry is supported");
351 jump_to_native_invoker(_masm, member_reg, temp1);
352 } else {
353 // The method is a member invoker used by direct method handles.
354 if (VerifyMethodHandles) {
355 // make sure the trailing argument really is a MemberName (caller responsibility)
356 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
357 "MemberName required for invokeVirtual etc.");
358 }
359
360 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
361 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
362 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
363 Address vmtarget_method( xmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
364
365 Register temp1_recv_klass = temp1;
366 if (iid != vmIntrinsics::_linkToStatic) {
367 __ verify_oop(receiver_reg);
368 if (iid == vmIntrinsics::_linkToSpecial) {
369 // Don't actually load the klass; just null-check the receiver.
370 __ null_check(receiver_reg);
371 } else {
372 // load receiver klass itself
373 __ load_klass(temp1_recv_klass, receiver_reg);
374 __ verify_klass_ptr(temp1_recv_klass);
375 }
376 BLOCK_COMMENT("check_receiver {");
377 // The receiver for the MemberName must be in receiver_reg.
378 // Check the receiver against the MemberName.clazz
379 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
380 // Did not load it above...
381 __ load_klass(temp1_recv_klass, receiver_reg);
382 __ verify_klass_ptr(temp1_recv_klass);
383 }
384 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
385 Label L_ok;
386 Register temp2_defc = temp2;
387 __ load_heap_oop(temp2_defc, member_clazz, temp3, t1);
388 load_klass_from_Class(_masm, temp2_defc);
389 __ verify_klass_ptr(temp2_defc);
390 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
391 // If we get here, the type check failed!
392 __ ebreak();
393 __ bind(L_ok);
394 }
395 BLOCK_COMMENT("} check_receiver");
396 }
397 if (iid == vmIntrinsics::_linkToSpecial ||
398 iid == vmIntrinsics::_linkToStatic) {
399 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
400 }
401
402 // Live registers at this point:
403 // member_reg - MemberName that was the trailing argument
404 // temp1_recv_klass - klass of stacked receiver, if needed
405 // x19 - interpreter linkage (if interpreted)
406 // x11 ... x10 - compiler arguments (if compiled)
407
408 Label L_incompatible_class_change_error;
409 switch (iid) {
410 case vmIntrinsics::_linkToSpecial:
411 if (VerifyMethodHandles) {
412 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
413 }
414 __ load_heap_oop(xmethod, member_vmtarget, temp3, t1);
415 __ access_load_at(T_ADDRESS, IN_HEAP, xmethod, vmtarget_method, noreg, noreg);
416 break;
417
418 case vmIntrinsics::_linkToStatic:
419 if (VerifyMethodHandles) {
420 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
421 }
422 __ load_heap_oop(xmethod, member_vmtarget, temp3, t1);
423 __ access_load_at(T_ADDRESS, IN_HEAP, xmethod, vmtarget_method, noreg, noreg);
424 break;
425
426 case vmIntrinsics::_linkToVirtual:
427 {
428 // same as TemplateTable::invokevirtual,
429 // minus the CP setup and profiling:
430
431 if (VerifyMethodHandles) {
432 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
433 }
434
435 // pick out the vtable index from the MemberName, and then we can discard it:
436 Register temp2_index = temp2;
437 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
438
439 if (VerifyMethodHandles) {
440 Label L_index_ok;
441 __ bgez(temp2_index, L_index_ok);
442 __ ebreak();
443 __ BIND(L_index_ok);
444 }
445
446 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
447 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
448
449 // get target Method* & entry point
450 __ lookup_virtual_method(temp1_recv_klass, temp2_index, xmethod);
451 break;
452 }
453
454 case vmIntrinsics::_linkToInterface:
455 {
456 // same as TemplateTable::invokeinterface
457 // (minus the CP setup and profiling, with different argument motion)
458 if (VerifyMethodHandles) {
459 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
460 }
461
462 Register temp3_intf = temp3;
463 __ load_heap_oop(temp3_intf, member_clazz, temp2, t1);
464 load_klass_from_Class(_masm, temp3_intf);
465 __ verify_klass_ptr(temp3_intf);
466
467 Register rindex = xmethod;
468 __ access_load_at(T_ADDRESS, IN_HEAP, rindex, member_vmindex, noreg, noreg);
469 if (VerifyMethodHandles) {
470 Label L;
471 __ bgez(rindex, L);
472 __ ebreak();
473 __ bind(L);
474 }
475
476 // given intf, index, and recv klass, dispatch to the implementation method
477 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
478 // note: next two args must be the same:
479 rindex, xmethod,
480 temp2,
481 L_incompatible_class_change_error);
482 break;
483 }
484
485 default:
486 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
487 break;
488 }
489
490 // live at this point: xmethod, x19_sender_sp (if interpreted)
491
492 // After figuring out which concrete method to call, jump into it.
493 // Note that this works in the interpreter with no data motion.
494 // But the compiled version will require that r2_recv be shifted out.
495 jump_from_method_handle(_masm, xmethod, temp1, for_compiler_entry, iid);
496 if (iid == vmIntrinsics::_linkToInterface) {
497 __ bind(L_incompatible_class_change_error);
498 __ far_jump(RuntimeAddress(SharedRuntime::throw_IncompatibleClassChangeError_entry()));
499 }
500 }
501 }
502
503 #ifndef PRODUCT
504 void trace_method_handle_stub(const char* adaptername,
505 oopDesc* mh,
506 intptr_t* saved_regs,
507 intptr_t* entry_sp) { }
508
509 // The stub wraps the arguments in a struct on the stack to avoid
510 // dealing with the different calling conventions for passing 6
511 // arguments.
512 struct MethodHandleStubArguments {
513 const char* adaptername;
514 oopDesc* mh;
515 intptr_t* saved_regs;
516 intptr_t* entry_sp;
517 };
518 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { }
519
520 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { }
521 #endif //PRODUCT