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 #endif //ASSERT
97
98 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
99 bool for_compiler_entry) {
100 assert(method == rmethod, "interpreter calling convention");
101 Label L_no_such_method;
102 __ cbz(rmethod, L_no_such_method);
103 __ verify_method_ptr(method);
104
105 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
106 Label run_compiled_code;
107 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
108 // compiled code in threads for which the event is enabled. Check here for
109 // interp_only_mode if these events CAN be enabled.
110
111 __ ldrw(rscratch1, Address(rthread, JavaThread::interp_only_mode_offset()));
112 __ cbzw(rscratch1, run_compiled_code);
113 __ ldr(rscratch1, Address(method, Method::interpreter_entry_offset()));
114 __ br(rscratch1);
115 __ BIND(run_compiled_code);
116 }
117
118 // The following jump might pass an inline type argument that was erased to Object as oop to a
119 // callee that expects inline type arguments to be passed as fields. We need to call the compiled
120 // value entry (_code->inline_entry_point() or _adapter->c2i_inline_entry()) which will take care
121 // of translating between the calling conventions.
122 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_inline_offset() :
123 Method::from_interpreted_offset();
124 __ ldr(rscratch1,Address(method, entry_offset));
125 __ br(rscratch1);
126 __ bind(L_no_such_method);
127 __ far_jump(RuntimeAddress(SharedRuntime::throw_AbstractMethodError_entry()));
128 }
129
130 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
131 Register recv, Register method_temp,
132 Register temp2,
133 bool for_compiler_entry) {
134 BLOCK_COMMENT("jump_to_lambda_form {");
135 // This is the initial entry point of a lazy method handle.
136 // After type checking, it picks up the invoker from the LambdaForm.
137 assert_different_registers(recv, method_temp, temp2);
138 assert(recv != noreg, "required register");
139 assert(method_temp == rmethod, "required register for loading method");
140
141 // Load the invoker, as MH -> MH.form -> LF.vmentry
142 __ verify_oop(recv);
143 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2, rscratch2);
144 __ verify_oop(method_temp);
145 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2, rscratch2);
146 __ verify_oop(method_temp);
147 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2, rscratch2);
148 __ verify_oop(method_temp);
149 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), noreg, noreg);
150
151 if (VerifyMethodHandles && !for_compiler_entry) {
152 // make sure recv is already on stack
153 __ ldr(temp2, Address(method_temp, Method::const_offset()));
154 __ load_sized_value(temp2,
155 Address(temp2, ConstMethod::size_of_parameters_offset()),
156 sizeof(u2), /*is_signed*/ false);
157 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
158 Label L;
159 __ ldr(rscratch1, __ argument_address(temp2, -1));
160 __ cmpoop(recv, rscratch1);
161 __ br(Assembler::EQ, L);
162 __ ldr(r0, __ argument_address(temp2, -1));
163 __ hlt(0);
164 __ BIND(L);
165 }
166
167 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
168 BLOCK_COMMENT("} jump_to_lambda_form");
169 }
170
171 // Code generation
172 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
173 vmIntrinsics::ID iid) {
174 const bool not_for_compiler_entry = false; // this is the interpreter entry
175 assert(is_signature_polymorphic(iid), "expected invoke iid");
176 if (iid == vmIntrinsics::_invokeGeneric ||
177 iid == vmIntrinsics::_compiledLambdaForm) {
178 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
179 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
180 // They all allow an appendix argument.
181 __ hlt(0); // empty stubs make SG sick
182 return nullptr;
183 }
184
185 // No need in interpreter entry for linkToNative for now.
186 // Interpreter calls compiled entry through i2c.
187 if (iid == vmIntrinsics::_linkToNative) {
188 __ hlt(0);
189 return nullptr;
190 }
191
192 // r19_sender_sp: sender SP (must preserve; see prepare_to_jump_from_interpreted)
193 // rmethod: Method*
194 // r3: argument locator (parameter slot count, added to rsp)
195 // r1: used as temp to hold mh or receiver
196 // r0, r11: garbage temps, blown away
197 Register argp = r3; // argument list ptr, live on error paths
198 Register temp = r0;
199 Register mh = r1; // MH receiver; dies quickly and is recycled
200
201 // here's where control starts out:
202 __ align(CodeEntryAlignment);
203 address entry_point = __ pc();
204
205 if (VerifyMethodHandles) {
206 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
207
208 Label L;
209 BLOCK_COMMENT("verify_intrinsic_id {");
210 __ ldrh(rscratch1, Address(rmethod, Method::intrinsic_id_offset()));
211 __ subs(zr, rscratch1, (int) iid);
212 __ br(Assembler::EQ, L);
213 if (iid == vmIntrinsics::_linkToVirtual ||
214 iid == vmIntrinsics::_linkToSpecial) {
215 // could do this for all kinds, but would explode assembly code size
216 trace_method_handle(_masm, "bad Method*::intrinsic_id");
217 }
218 __ hlt(0);
219 __ bind(L);
220 BLOCK_COMMENT("} verify_intrinsic_id");
221 }
222
223 // First task: Find out how big the argument list is.
224 Address r3_first_arg_addr;
225 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
226 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
227 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
228 __ ldr(argp, Address(rmethod, Method::const_offset()));
229 __ load_sized_value(argp,
230 Address(argp, ConstMethod::size_of_parameters_offset()),
231 sizeof(u2), /*is_signed*/ false);
232 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
233 r3_first_arg_addr = __ argument_address(argp, -1);
234 } else {
235 DEBUG_ONLY(argp = noreg);
236 }
237
238 if (!is_signature_polymorphic_static(iid)) {
239 __ ldr(mh, r3_first_arg_addr);
240 DEBUG_ONLY(argp = noreg);
241 }
242
243 // r3_first_arg_addr is live!
244
245 trace_method_handle_interpreter_entry(_masm, iid);
246 if (iid == vmIntrinsics::_invokeBasic) {
247 generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
248
249 } else {
250 // Adjust argument list by popping the trailing MemberName argument.
251 Register recv = noreg;
252 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
253 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
254 __ ldr(recv = r2, r3_first_arg_addr);
255 }
256 DEBUG_ONLY(argp = noreg);
257 Register rmember = rmethod; // MemberName ptr; incoming method ptr is dead now
258 __ pop(rmember); // extract last argument
259 generate_method_handle_dispatch(_masm, iid, recv, rmember, not_for_compiler_entry);
260 }
261
262 return entry_point;
263 }
264
265 void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) {
266 BLOCK_COMMENT("jump_to_native_invoker {");
267 assert_different_registers(nep_reg, temp_target);
268 assert(nep_reg != noreg, "required register");
269
270 // Load the invoker, as NEP -> .invoker
271 __ verify_oop(nep_reg);
272 __ access_load_at(T_ADDRESS, IN_HEAP, temp_target,
273 Address(nep_reg, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes())),
274 noreg, noreg);
275
276 __ br(temp_target);
277 BLOCK_COMMENT("} jump_to_native_invoker");
278 }
279
280
281 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
282 vmIntrinsics::ID iid,
283 Register receiver_reg,
284 Register member_reg,
285 bool for_compiler_entry) {
286 assert(is_signature_polymorphic(iid), "expected invoke iid");
287 // temps used in this code are not used in *either* compiled or interpreted calling sequences
288 Register temp1 = r10;
289 Register temp2 = r11;
290 Register temp3 = r14;
291 if (for_compiler_entry) {
292 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment");
293 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
294 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
295 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
296 }
297
298 assert_different_registers(temp1, temp2, temp3, receiver_reg);
299 assert_different_registers(temp1, temp2, temp3, member_reg);
300
301 if (iid == vmIntrinsics::_invokeBasic) {
302 // indirect through MH.form.vmentry.vmtarget
303 jump_to_lambda_form(_masm, receiver_reg, rmethod, temp1, for_compiler_entry);
304
305 } else if (iid == vmIntrinsics::_linkToNative) {
306 assert(for_compiler_entry, "only compiler entry is supported");
307 jump_to_native_invoker(_masm, member_reg, temp1);
308 } else {
309 // The method is a member invoker used by direct method handles.
310 if (VerifyMethodHandles) {
311 // make sure the trailing argument really is a MemberName (caller responsibility)
312 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
313 "MemberName required for invokeVirtual etc.");
314 }
315
316 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
317 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
318 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
319 Address vmtarget_method( rmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
320
321 Register temp1_recv_klass = temp1;
322 if (iid != vmIntrinsics::_linkToStatic) {
323 __ verify_oop(receiver_reg);
324 if (iid == vmIntrinsics::_linkToSpecial) {
325 // Don't actually load the klass; just null-check the receiver.
326 __ null_check(receiver_reg);
327 } else {
328 // load receiver klass itself
329 __ load_klass(temp1_recv_klass, receiver_reg);
330 __ verify_klass_ptr(temp1_recv_klass);
331 }
332 BLOCK_COMMENT("check_receiver {");
333 // The receiver for the MemberName must be in receiver_reg.
334 // Check the receiver against the MemberName.clazz
335 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
336 // Did not load it above...
337 __ load_klass(temp1_recv_klass, receiver_reg);
338 __ verify_klass_ptr(temp1_recv_klass);
339 }
340 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
341 Label L_ok;
342 Register temp2_defc = temp2;
343 __ load_heap_oop(temp2_defc, member_clazz, temp3, rscratch2);
344 load_klass_from_Class(_masm, temp2_defc);
345 __ verify_klass_ptr(temp2_defc);
346 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
347 // If we get here, the type check failed!
348 __ hlt(0);
349 // __ STOP("receiver class disagrees with MemberName.clazz");
350 __ bind(L_ok);
351 }
352 BLOCK_COMMENT("} check_receiver");
353 }
354 if (iid == vmIntrinsics::_linkToSpecial ||
355 iid == vmIntrinsics::_linkToStatic) {
356 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
357 }
358
359 // Live registers at this point:
360 // member_reg - MemberName that was the trailing argument
361 // temp1_recv_klass - klass of stacked receiver, if needed
362 // r19 - interpreter linkage (if interpreted)
363 // r1 ... r0 - compiler arguments (if compiled)
364
365 Label L_incompatible_class_change_error;
366 switch (iid) {
367 case vmIntrinsics::_linkToSpecial:
368 if (VerifyMethodHandles) {
369 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
370 }
371 __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
372 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
373 break;
374
375 case vmIntrinsics::_linkToStatic:
376 if (VerifyMethodHandles) {
377 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
378 }
379 __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
380 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
381 break;
382
383 case vmIntrinsics::_linkToVirtual:
384 {
385 // same as TemplateTable::invokevirtual,
386 // minus the CP setup and profiling:
387
388 if (VerifyMethodHandles) {
389 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
390 }
391
392 // pick out the vtable index from the MemberName, and then we can discard it:
393 Register temp2_index = temp2;
394 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
395
396 if (VerifyMethodHandles) {
397 Label L_index_ok;
398 __ cmpw(temp2_index, 0U);
399 __ br(Assembler::GE, L_index_ok);
400 __ hlt(0);
401 __ BIND(L_index_ok);
402 }
403
404 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
405 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
406
407 // get target Method* & entry point
408 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rmethod);
409 break;
410 }
411
412 case vmIntrinsics::_linkToInterface:
413 {
414 // same as TemplateTable::invokeinterface
415 // (minus the CP setup and profiling, with different argument motion)
416 if (VerifyMethodHandles) {
417 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
418 }
419
420 Register temp3_intf = temp3;
421 __ load_heap_oop(temp3_intf, member_clazz, temp2, rscratch2);
422 load_klass_from_Class(_masm, temp3_intf);
423 __ verify_klass_ptr(temp3_intf);
424
425 Register rindex = rmethod;
426 __ access_load_at(T_ADDRESS, IN_HEAP, rindex, member_vmindex, noreg, noreg);
427 if (VerifyMethodHandles) {
428 Label L;
429 __ cmpw(rindex, 0U);
430 __ br(Assembler::GE, L);
431 __ hlt(0);
432 __ bind(L);
433 }
434
435 // given intf, index, and recv klass, dispatch to the implementation method
436 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
437 // note: next two args must be the same:
438 rindex, rmethod,
439 temp2,
440 L_incompatible_class_change_error);
441 break;
442 }
443
444 default:
445 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
446 break;
447 }
448
449 // live at this point: rmethod, r19_sender_sp (if interpreted)
450
451 // After figuring out which concrete method to call, jump into it.
452 // Note that this works in the interpreter with no data motion.
453 // But the compiled version will require that r2_recv be shifted out.
454 __ verify_method_ptr(rmethod);
455 jump_from_method_handle(_masm, rmethod, temp1, for_compiler_entry);
456 if (iid == vmIntrinsics::_linkToInterface) {
457 __ bind(L_incompatible_class_change_error);
458 __ far_jump(RuntimeAddress(SharedRuntime::throw_IncompatibleClassChangeError_entry()));
459 }
460 }
461 }
462
463 #ifndef PRODUCT
464 void trace_method_handle_stub(const char* adaptername,
465 oopDesc* mh,
466 intptr_t* saved_regs,
467 intptr_t* entry_sp) { }
468
469 // The stub wraps the arguments in a struct on the stack to avoid
470 // dealing with the different calling conventions for passing 6
471 // arguments.
472 struct MethodHandleStubArguments {
473 const char* adaptername;
474 oopDesc* mh;
475 intptr_t* saved_regs;
476 intptr_t* entry_sp;
477 };
478 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { }
479
480 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { }
481 #endif //PRODUCT