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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "asm/macroAssembler.hpp"
27 #include "classfile/javaClasses.inline.hpp"
28 #include "classfile/vmClasses.hpp"
29 #include "compiler/disassembler.hpp"
30 #include "interpreter/interpreter.hpp"
31 #include "interpreter/interpreterRuntime.hpp"
32 #include "memory/allocation.inline.hpp"
33 #include "prims/jvmtiExport.hpp"
34 #include "prims/methodHandles.hpp"
35 #include "runtime/flags/flagSetting.hpp"
36 #include "runtime/frame.inline.hpp"
37 #include "runtime/stubRoutines.hpp"
38
39 #define __ Disassembler::hook<MacroAssembler>(__FILE__, __LINE__, _masm)->
40
41 #ifdef PRODUCT
42 #define BLOCK_COMMENT(str) /* nothing */
43 #else
44 #define BLOCK_COMMENT(str) __ block_comment(str)
45 #endif
46
47 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
48
49 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) {
50 if (VerifyMethodHandles)
51 verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class),
52 "MH argument is a Class");
53 __ ldr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset()));
54 }
55
56 #ifdef ASSERT
57 static int check_nonzero(const char* xname, int x) {
58 assert(x != 0, "%s should be nonzero", xname);
59 return x;
60 }
61 #define NONZERO(x) check_nonzero(#x, x)
62 #else //ASSERT
63 #define NONZERO(x) (x)
64 #endif //PRODUCT
65
66 #ifdef ASSERT
67 void MethodHandles::verify_klass(MacroAssembler* _masm,
68 Register obj, vmClassID klass_id,
69 const char* error_message) {
70 InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id);
71 Klass* klass = vmClasses::klass_at(klass_id);
72 Register temp = rscratch2;
73 Register temp2 = rscratch1; // used by MacroAssembler::cmpptr
74 Label L_ok, L_bad;
75 BLOCK_COMMENT("verify_klass {");
76 __ verify_oop(obj);
77 __ cbz(obj, L_bad);
78 __ push(RegSet::of(temp, temp2), sp);
79 __ load_klass(temp, obj);
80 __ cmpptr(temp, ExternalAddress((address) klass_addr));
81 __ br(Assembler::EQ, L_ok);
82 intptr_t super_check_offset = klass->super_check_offset();
83 __ ldr(temp, Address(temp, super_check_offset));
84 __ cmpptr(temp, ExternalAddress((address) klass_addr));
85 __ br(Assembler::EQ, L_ok);
86 __ pop(RegSet::of(temp, temp2), sp);
87 __ bind(L_bad);
88 __ stop(error_message);
89 __ BIND(L_ok);
90 __ pop(RegSet::of(temp, temp2), sp);
91 BLOCK_COMMENT("} verify_klass");
92 }
93
94 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) { }
95
96 void MethodHandles::verify_method(MacroAssembler* _masm, Register method, vmIntrinsics::ID iid) {
97 BLOCK_COMMENT("verify_method {");
98 __ verify_method_ptr(method);
99 if (VerifyMethodHandles) {
100 Label L_ok;
101 assert_different_registers(method, rscratch1, rscratch2);
102 const Register method_holder = rscratch1;
103 __ load_method_holder(method_holder, method);
104
105 switch (iid) {
106 case vmIntrinsicID::_invokeBasic:
107 // Require compiled LambdaForm class to be fully initialized.
108 __ lea(rscratch2, Address(method_holder, InstanceKlass::init_state_offset()));
109 __ ldarb(rscratch2, rscratch2);
110 __ cmp(rscratch2, InstanceKlass::fully_initialized);
111 __ br(Assembler::EQ, L_ok);
112 break;
113
114 case vmIntrinsicID::_linkToStatic:
115 __ clinit_barrier(method_holder, rscratch2, &L_ok);
116 break;
117
118 case vmIntrinsicID::_linkToVirtual:
119 case vmIntrinsicID::_linkToSpecial:
120 case vmIntrinsicID::_linkToInterface:
121 // Class initialization check is too strong here. Just ensure that class initialization has been initiated.
122 __ lea(rscratch2, Address(method_holder, InstanceKlass::init_state_offset()));
123 __ ldarb(rscratch2, rscratch2);
124 __ cmp(rscratch2, InstanceKlass::being_initialized);
125 __ br(Assembler::GE, L_ok);
126
127 // init_state check failed, but it may be an abstract interface method
128 __ ldrh(rscratch2, Address(method, Method::access_flags_offset()));
129 __ tbnz(rscratch2, exact_log2(JVM_ACC_ABSTRACT), L_ok);
130 break;
131
132 default:
133 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
134 }
135
136 // Method holder init state check failed for a concrete method.
137 __ stop("Method holder klass is not initialized");
138 __ bind(L_ok);
139 }
140 BLOCK_COMMENT("} verify_method");
141 }
142 #endif //ASSERT
143
144 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
145 bool for_compiler_entry, vmIntrinsics::ID iid) {
146 assert(method == rmethod, "interpreter calling convention");
147 Label L_no_such_method;
148 __ cbz(rmethod, L_no_such_method);
149 verify_method(_masm, method, iid);
150
151 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
152 Label run_compiled_code;
153 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
154 // compiled code in threads for which the event is enabled. Check here for
155 // interp_only_mode if these events CAN be enabled.
156
157 __ ldrw(rscratch1, Address(rthread, JavaThread::interp_only_mode_offset()));
158 __ cbzw(rscratch1, run_compiled_code);
159 __ ldr(rscratch1, Address(method, Method::interpreter_entry_offset()));
160 __ br(rscratch1);
161 __ BIND(run_compiled_code);
162 }
163
164 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
165 Method::from_interpreted_offset();
166 __ ldr(rscratch1,Address(method, entry_offset));
167 __ br(rscratch1);
168 __ bind(L_no_such_method);
169 __ far_jump(RuntimeAddress(SharedRuntime::throw_AbstractMethodError_entry()));
170 }
171
172 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
173 Register recv, Register method_temp,
174 Register temp2,
175 bool for_compiler_entry) {
176 BLOCK_COMMENT("jump_to_lambda_form {");
177 // This is the initial entry point of a lazy method handle.
178 // After type checking, it picks up the invoker from the LambdaForm.
179 assert_different_registers(recv, method_temp, temp2);
180 assert(recv != noreg, "required register");
181 assert(method_temp == rmethod, "required register for loading method");
182
183 // Load the invoker, as MH -> MH.form -> LF.vmentry
184 __ verify_oop(recv);
185 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2, rscratch2);
186 __ verify_oop(method_temp);
187 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2, rscratch2);
188 __ verify_oop(method_temp);
189 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2, rscratch2);
190 __ verify_oop(method_temp);
191 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), noreg, noreg);
192
193 if (VerifyMethodHandles && !for_compiler_entry) {
194 // make sure recv is already on stack
195 __ ldr(temp2, Address(method_temp, Method::const_offset()));
196 __ load_sized_value(temp2,
197 Address(temp2, ConstMethod::size_of_parameters_offset()),
198 sizeof(u2), /*is_signed*/ false);
199 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
200 Label L;
201 __ ldr(rscratch1, __ argument_address(temp2, -1));
202 __ cmpoop(recv, rscratch1);
203 __ br(Assembler::EQ, L);
204 __ ldr(r0, __ argument_address(temp2, -1));
205 __ hlt(0);
206 __ BIND(L);
207 }
208
209 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry, vmIntrinsics::_invokeBasic);
210 BLOCK_COMMENT("} jump_to_lambda_form");
211 }
212
213 // Code generation
214 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
215 vmIntrinsics::ID iid) {
216 const bool not_for_compiler_entry = false; // this is the interpreter entry
217 assert(is_signature_polymorphic(iid), "expected invoke iid");
218 if (iid == vmIntrinsics::_invokeGeneric ||
219 iid == vmIntrinsics::_compiledLambdaForm) {
220 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
221 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
222 // They all allow an appendix argument.
223 __ hlt(0); // empty stubs make SG sick
224 return nullptr;
225 }
226
227 // No need in interpreter entry for linkToNative for now.
228 // Interpreter calls compiled entry through i2c.
229 if (iid == vmIntrinsics::_linkToNative) {
230 __ hlt(0);
231 return nullptr;
232 }
233
234 // r19_sender_sp: sender SP (must preserve; see prepare_to_jump_from_interpreted)
235 // rmethod: Method*
236 // r3: argument locator (parameter slot count, added to rsp)
237 // r1: used as temp to hold mh or receiver
238 // r0, r11: garbage temps, blown away
239 Register argp = r3; // argument list ptr, live on error paths
240 Register temp = r0;
241 Register mh = r1; // MH receiver; dies quickly and is recycled
242
243 // here's where control starts out:
244 __ align(CodeEntryAlignment);
245 address entry_point = __ pc();
246
247 if (VerifyMethodHandles) {
248 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
249
250 Label L;
251 BLOCK_COMMENT("verify_intrinsic_id {");
252 __ ldrh(rscratch1, Address(rmethod, Method::intrinsic_id_offset()));
253 __ subs(zr, rscratch1, (int) iid);
254 __ br(Assembler::EQ, L);
255 if (iid == vmIntrinsics::_linkToVirtual ||
256 iid == vmIntrinsics::_linkToSpecial) {
257 // could do this for all kinds, but would explode assembly code size
258 trace_method_handle(_masm, "bad Method*::intrinsic_id");
259 }
260 __ hlt(0);
261 __ bind(L);
262 BLOCK_COMMENT("} verify_intrinsic_id");
263 }
264
265 // First task: Find out how big the argument list is.
266 Address r3_first_arg_addr;
267 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
268 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
269 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
270 __ ldr(argp, Address(rmethod, Method::const_offset()));
271 __ load_sized_value(argp,
272 Address(argp, ConstMethod::size_of_parameters_offset()),
273 sizeof(u2), /*is_signed*/ false);
274 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
275 r3_first_arg_addr = __ argument_address(argp, -1);
276 } else {
277 DEBUG_ONLY(argp = noreg);
278 }
279
280 if (!is_signature_polymorphic_static(iid)) {
281 __ ldr(mh, r3_first_arg_addr);
282 DEBUG_ONLY(argp = noreg);
283 }
284
285 // r3_first_arg_addr is live!
286
287 trace_method_handle_interpreter_entry(_masm, iid);
288 if (iid == vmIntrinsics::_invokeBasic) {
289 generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
290
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 __ ldr(recv = r2, r3_first_arg_addr);
297 }
298 DEBUG_ONLY(argp = noreg);
299 Register rmember = rmethod; // MemberName ptr; incoming method ptr is dead now
300 __ pop(rmember); // extract last argument
301 generate_method_handle_dispatch(_masm, iid, recv, rmember, 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 __ br(temp_target);
319 BLOCK_COMMENT("} jump_to_native_invoker");
320 }
321
322
323 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
324 vmIntrinsics::ID iid,
325 Register receiver_reg,
326 Register member_reg,
327 bool for_compiler_entry) {
328 assert(is_signature_polymorphic(iid), "expected invoke iid");
329 // temps used in this code are not used in *either* compiled or interpreted calling sequences
330 Register temp1 = r10;
331 Register temp2 = r11;
332 Register temp3 = r14;
333 if (for_compiler_entry) {
334 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment");
335 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
336 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
337 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
338 }
339
340 assert_different_registers(temp1, temp2, temp3, receiver_reg);
341 assert_different_registers(temp1, temp2, temp3, member_reg);
342
343 if (iid == vmIntrinsics::_invokeBasic) {
344 // indirect through MH.form.vmentry.vmtarget
345 jump_to_lambda_form(_masm, receiver_reg, rmethod, temp1, for_compiler_entry);
346
347 } else if (iid == vmIntrinsics::_linkToNative) {
348 assert(for_compiler_entry, "only compiler entry is supported");
349 jump_to_native_invoker(_masm, member_reg, temp1);
350 } else {
351 // The method is a member invoker used by direct method handles.
352 if (VerifyMethodHandles) {
353 // make sure the trailing argument really is a MemberName (caller responsibility)
354 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
355 "MemberName required for invokeVirtual etc.");
356 }
357
358 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
359 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
360 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
361 Address vmtarget_method( rmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
362
363 Register temp1_recv_klass = temp1;
364 if (iid != vmIntrinsics::_linkToStatic) {
365 __ verify_oop(receiver_reg);
366 if (iid == vmIntrinsics::_linkToSpecial) {
367 // Don't actually load the klass; just null-check the receiver.
368 __ null_check(receiver_reg);
369 } else {
370 // load receiver klass itself
371 __ load_klass(temp1_recv_klass, receiver_reg);
372 __ verify_klass_ptr(temp1_recv_klass);
373 }
374 BLOCK_COMMENT("check_receiver {");
375 // The receiver for the MemberName must be in receiver_reg.
376 // Check the receiver against the MemberName.clazz
377 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
378 // Did not load it above...
379 __ load_klass(temp1_recv_klass, receiver_reg);
380 __ verify_klass_ptr(temp1_recv_klass);
381 }
382 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
383 Label L_ok;
384 Register temp2_defc = temp2;
385 __ load_heap_oop(temp2_defc, member_clazz, temp3, rscratch2);
386 load_klass_from_Class(_masm, temp2_defc);
387 __ verify_klass_ptr(temp2_defc);
388 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
389 // If we get here, the type check failed!
390 __ hlt(0);
391 // __ STOP("receiver class disagrees with MemberName.clazz");
392 __ bind(L_ok);
393 }
394 BLOCK_COMMENT("} check_receiver");
395 }
396 if (iid == vmIntrinsics::_linkToSpecial ||
397 iid == vmIntrinsics::_linkToStatic) {
398 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
399 }
400
401 // Live registers at this point:
402 // member_reg - MemberName that was the trailing argument
403 // temp1_recv_klass - klass of stacked receiver, if needed
404 // r19 - interpreter linkage (if interpreted)
405 // r1 ... r0 - compiler arguments (if compiled)
406
407 Label L_incompatible_class_change_error;
408 switch (iid) {
409 case vmIntrinsics::_linkToSpecial:
410 if (VerifyMethodHandles) {
411 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
412 }
413 __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
414 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
415 break;
416
417 case vmIntrinsics::_linkToStatic:
418 if (VerifyMethodHandles) {
419 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
420 }
421 __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
422 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
423 break;
424
425 case vmIntrinsics::_linkToVirtual:
426 {
427 // same as TemplateTable::invokevirtual,
428 // minus the CP setup and profiling:
429
430 if (VerifyMethodHandles) {
431 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
432 }
433
434 // pick out the vtable index from the MemberName, and then we can discard it:
435 Register temp2_index = temp2;
436 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
437
438 if (VerifyMethodHandles) {
439 Label L_index_ok;
440 __ cmpw(temp2_index, 0U);
441 __ br(Assembler::GE, L_index_ok);
442 __ hlt(0);
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, rmethod);
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, rscratch2);
464 load_klass_from_Class(_masm, temp3_intf);
465 __ verify_klass_ptr(temp3_intf);
466
467 Register rindex = rmethod;
468 __ access_load_at(T_ADDRESS, IN_HEAP, rindex, member_vmindex, noreg, noreg);
469 if (VerifyMethodHandles) {
470 Label L;
471 __ cmpw(rindex, 0U);
472 __ br(Assembler::GE, L);
473 __ hlt(0);
474 __ bind(L);
475 }
476
477 // given intf, index, and recv klass, dispatch to the implementation method
478 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
479 // note: next two args must be the same:
480 rindex, rmethod,
481 temp2,
482 L_incompatible_class_change_error);
483 break;
484 }
485
486 default:
487 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
488 break;
489 }
490
491 // live at this point: rmethod, r19_sender_sp (if interpreted)
492
493 // After figuring out which concrete method to call, jump into it.
494 // Note that this works in the interpreter with no data motion.
495 // But the compiled version will require that r2_recv be shifted out.
496 jump_from_method_handle(_masm, rmethod, temp1, for_compiler_entry, iid);
497 if (iid == vmIntrinsics::_linkToInterface) {
498 __ bind(L_incompatible_class_change_error);
499 __ far_jump(RuntimeAddress(SharedRuntime::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
510 // The stub wraps the arguments in a struct on the stack to avoid
511 // dealing with the different calling conventions for passing 6
512 // arguments.
513 struct MethodHandleStubArguments {
514 const char* adaptername;
515 oopDesc* mh;
516 intptr_t* saved_regs;
517 intptr_t* entry_sp;
518 };
519 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { }
520
521 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { }
522 #endif //PRODUCT