1 /*
2 * Copyright (c) 1997, 2024, 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 "precompiled.hpp"
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 __ ldr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset()));
55 }
56
57 #ifdef ASSERT
58 static int check_nonzero(const char* xname, int x) {
59 assert(x != 0, "%s should be nonzero", xname);
60 return x;
61 }
62 #define NONZERO(x) check_nonzero(#x, x)
63 #else //ASSERT
64 #define NONZERO(x) (x)
65 #endif //PRODUCT
66
67 #ifdef ASSERT
68 void MethodHandles::verify_klass(MacroAssembler* _masm,
69 Register obj, vmClassID klass_id,
70 const char* error_message) {
71 InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id);
72 Klass* klass = vmClasses::klass_at(klass_id);
73 Register temp = rscratch2;
74 Register temp2 = rscratch1; // used by MacroAssembler::cmpptr
75 Label L_ok, L_bad;
76 BLOCK_COMMENT("verify_klass {");
77 __ verify_oop(obj);
78 __ cbz(obj, L_bad);
79 __ push(RegSet::of(temp, temp2), sp);
80 __ load_klass(temp, obj);
81 __ cmpptr(temp, ExternalAddress((address) klass_addr));
82 __ br(Assembler::EQ, L_ok);
83 intptr_t super_check_offset = klass->super_check_offset();
84 __ ldr(temp, Address(temp, super_check_offset));
85 __ cmpptr(temp, ExternalAddress((address) klass_addr));
86 __ br(Assembler::EQ, L_ok);
87 __ pop(RegSet::of(temp, temp2), sp);
88 __ bind(L_bad);
89 __ stop(error_message);
90 __ BIND(L_ok);
91 __ pop(RegSet::of(temp, temp2), sp);
92 BLOCK_COMMENT("} verify_klass");
93 }
94
95 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) { }
96
97 #endif //ASSERT
98
99 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp,
100 bool for_compiler_entry) {
101 assert(method == rmethod, "interpreter calling convention");
102 Label L_no_such_method;
103 __ cbz(rmethod, L_no_such_method);
104 __ verify_method_ptr(method);
105
106 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
107 Label run_compiled_code;
108 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
109 // compiled code in threads for which the event is enabled. Check here for
110 // interp_only_mode if these events CAN be enabled.
111
112 __ ldrw(rscratch1, Address(rthread, JavaThread::interp_only_mode_offset()));
113 __ cbzw(rscratch1, run_compiled_code);
114 __ ldr(rscratch1, Address(method, Method::interpreter_entry_offset()));
115 __ br(rscratch1);
116 __ BIND(run_compiled_code);
117 }
118
119 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
120 Method::from_interpreted_offset();
121 __ ldr(rscratch1,Address(method, entry_offset));
122 __ br(rscratch1);
123 __ bind(L_no_such_method);
124 __ far_jump(RuntimeAddress(SharedRuntime::throw_AbstractMethodError_entry()));
125 }
126
127 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
128 Register recv, Register method_temp,
129 Register temp2,
130 bool for_compiler_entry) {
131 BLOCK_COMMENT("jump_to_lambda_form {");
132 // This is the initial entry point of a lazy method handle.
133 // After type checking, it picks up the invoker from the LambdaForm.
134 assert_different_registers(recv, method_temp, temp2);
135 assert(recv != noreg, "required register");
136 assert(method_temp == rmethod, "required register for loading method");
137
138 // Load the invoker, as MH -> MH.form -> LF.vmentry
139 __ verify_oop(recv);
140 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2, rscratch2);
141 __ verify_oop(method_temp);
142 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2, rscratch2);
143 __ verify_oop(method_temp);
144 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2, rscratch2);
145 __ verify_oop(method_temp);
146 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), noreg, noreg);
147
148 if (VerifyMethodHandles && !for_compiler_entry) {
149 // make sure recv is already on stack
150 __ ldr(temp2, Address(method_temp, Method::const_offset()));
151 __ load_sized_value(temp2,
152 Address(temp2, ConstMethod::size_of_parameters_offset()),
153 sizeof(u2), /*is_signed*/ false);
154 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
155 Label L;
156 __ ldr(rscratch1, __ argument_address(temp2, -1));
157 __ cmpoop(recv, rscratch1);
158 __ br(Assembler::EQ, L);
159 __ ldr(r0, __ argument_address(temp2, -1));
160 __ hlt(0);
161 __ BIND(L);
162 }
163
164 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
165 BLOCK_COMMENT("} jump_to_lambda_form");
166 }
167
168 // Code generation
169 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
170 vmIntrinsics::ID iid) {
171 const bool not_for_compiler_entry = false; // this is the interpreter entry
172 assert(is_signature_polymorphic(iid), "expected invoke iid");
173 if (iid == vmIntrinsics::_invokeGeneric ||
174 iid == vmIntrinsics::_compiledLambdaForm) {
175 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
176 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
177 // They all allow an appendix argument.
178 __ hlt(0); // empty stubs make SG sick
179 return nullptr;
180 }
181
182 // No need in interpreter entry for linkToNative for now.
183 // Interpreter calls compiled entry through i2c.
184 if (iid == vmIntrinsics::_linkToNative) {
185 __ hlt(0);
186 return nullptr;
187 }
188
189 // r19_sender_sp: sender SP (must preserve; see prepare_to_jump_from_interpreted)
190 // rmethod: Method*
191 // r3: argument locator (parameter slot count, added to rsp)
192 // r1: used as temp to hold mh or receiver
193 // r0, r11: garbage temps, blown away
194 Register argp = r3; // argument list ptr, live on error paths
195 Register temp = r0;
196 Register mh = r1; // MH receiver; dies quickly and is recycled
197
198 // here's where control starts out:
199 __ align(CodeEntryAlignment);
200 address entry_point = __ pc();
201
202 if (VerifyMethodHandles) {
203 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
204
205 Label L;
206 BLOCK_COMMENT("verify_intrinsic_id {");
207 __ ldrh(rscratch1, Address(rmethod, Method::intrinsic_id_offset()));
208 __ subs(zr, rscratch1, (int) iid);
209 __ br(Assembler::EQ, L);
210 if (iid == vmIntrinsics::_linkToVirtual ||
211 iid == vmIntrinsics::_linkToSpecial) {
212 // could do this for all kinds, but would explode assembly code size
213 trace_method_handle(_masm, "bad Method*::intrinsic_id");
214 }
215 __ hlt(0);
216 __ bind(L);
217 BLOCK_COMMENT("} verify_intrinsic_id");
218 }
219
220 // First task: Find out how big the argument list is.
221 Address r3_first_arg_addr;
222 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
223 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
224 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
225 __ ldr(argp, Address(rmethod, Method::const_offset()));
226 __ load_sized_value(argp,
227 Address(argp, ConstMethod::size_of_parameters_offset()),
228 sizeof(u2), /*is_signed*/ false);
229 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
230 r3_first_arg_addr = __ argument_address(argp, -1);
231 } else {
232 DEBUG_ONLY(argp = noreg);
233 }
234
235 if (!is_signature_polymorphic_static(iid)) {
236 __ ldr(mh, r3_first_arg_addr);
237 DEBUG_ONLY(argp = noreg);
238 }
239
240 // r3_first_arg_addr is live!
241
242 trace_method_handle_interpreter_entry(_masm, iid);
243 if (iid == vmIntrinsics::_invokeBasic) {
244 generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
245
246 } else {
247 // Adjust argument list by popping the trailing MemberName argument.
248 Register recv = noreg;
249 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
250 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
251 __ ldr(recv = r2, r3_first_arg_addr);
252 }
253 DEBUG_ONLY(argp = noreg);
254 Register rmember = rmethod; // MemberName ptr; incoming method ptr is dead now
255 __ pop(rmember); // extract last argument
256 generate_method_handle_dispatch(_masm, iid, recv, rmember, not_for_compiler_entry);
257 }
258
259 return entry_point;
260 }
261
262 void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) {
263 BLOCK_COMMENT("jump_to_native_invoker {");
264 assert_different_registers(nep_reg, temp_target);
265 assert(nep_reg != noreg, "required register");
266
267 // Load the invoker, as NEP -> .invoker
268 __ verify_oop(nep_reg);
269 __ access_load_at(T_ADDRESS, IN_HEAP, temp_target,
270 Address(nep_reg, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes())),
271 noreg, noreg);
272
273 __ br(temp_target);
274 BLOCK_COMMENT("} jump_to_native_invoker");
275 }
276
277
278 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
279 vmIntrinsics::ID iid,
280 Register receiver_reg,
281 Register member_reg,
282 bool for_compiler_entry) {
283 assert(is_signature_polymorphic(iid), "expected invoke iid");
284 // temps used in this code are not used in *either* compiled or interpreted calling sequences
285 Register temp1 = r10;
286 Register temp2 = r11;
287 Register temp3 = r14;
288 if (for_compiler_entry) {
289 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment");
290 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
291 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
292 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
293 }
294
295 assert_different_registers(temp1, temp2, temp3, receiver_reg);
296 assert_different_registers(temp1, temp2, temp3, member_reg);
297
298 if (iid == vmIntrinsics::_invokeBasic) {
299 // indirect through MH.form.vmentry.vmtarget
300 jump_to_lambda_form(_masm, receiver_reg, rmethod, temp1, for_compiler_entry);
301
302 } else if (iid == vmIntrinsics::_linkToNative) {
303 assert(for_compiler_entry, "only compiler entry is supported");
304 jump_to_native_invoker(_masm, member_reg, temp1);
305 } else {
306 // The method is a member invoker used by direct method handles.
307 if (VerifyMethodHandles) {
308 // make sure the trailing argument really is a MemberName (caller responsibility)
309 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
310 "MemberName required for invokeVirtual etc.");
311 }
312
313 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
314 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
315 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
316 Address vmtarget_method( rmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
317
318 Register temp1_recv_klass = temp1;
319 if (iid != vmIntrinsics::_linkToStatic) {
320 __ verify_oop(receiver_reg);
321 if (iid == vmIntrinsics::_linkToSpecial) {
322 // Don't actually load the klass; just null-check the receiver.
323 __ null_check(receiver_reg);
324 } else {
325 // load receiver klass itself
326 __ load_klass(temp1_recv_klass, receiver_reg);
327 __ verify_klass_ptr(temp1_recv_klass);
328 }
329 BLOCK_COMMENT("check_receiver {");
330 // The receiver for the MemberName must be in receiver_reg.
331 // Check the receiver against the MemberName.clazz
332 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
333 // Did not load it above...
334 __ load_klass(temp1_recv_klass, receiver_reg);
335 __ verify_klass_ptr(temp1_recv_klass);
336 }
337 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
338 Label L_ok;
339 Register temp2_defc = temp2;
340 __ load_heap_oop(temp2_defc, member_clazz, temp3, rscratch2);
341 load_klass_from_Class(_masm, temp2_defc);
342 __ verify_klass_ptr(temp2_defc);
343 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
344 // If we get here, the type check failed!
345 __ hlt(0);
346 // __ STOP("receiver class disagrees with MemberName.clazz");
347 __ bind(L_ok);
348 }
349 BLOCK_COMMENT("} check_receiver");
350 }
351 if (iid == vmIntrinsics::_linkToSpecial ||
352 iid == vmIntrinsics::_linkToStatic) {
353 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
354 }
355
356 // Live registers at this point:
357 // member_reg - MemberName that was the trailing argument
358 // temp1_recv_klass - klass of stacked receiver, if needed
359 // r19 - interpreter linkage (if interpreted)
360 // r1 ... r0 - compiler arguments (if compiled)
361
362 Label L_incompatible_class_change_error;
363 switch (iid) {
364 case vmIntrinsics::_linkToSpecial:
365 if (VerifyMethodHandles) {
366 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
367 }
368 __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
369 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
370 break;
371
372 case vmIntrinsics::_linkToStatic:
373 if (VerifyMethodHandles) {
374 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
375 }
376 __ load_heap_oop(rmethod, member_vmtarget, temp3, rscratch2);
377 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
378 break;
379
380 case vmIntrinsics::_linkToVirtual:
381 {
382 // same as TemplateTable::invokevirtual,
383 // minus the CP setup and profiling:
384
385 if (VerifyMethodHandles) {
386 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
387 }
388
389 // pick out the vtable index from the MemberName, and then we can discard it:
390 Register temp2_index = temp2;
391 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
392
393 if (VerifyMethodHandles) {
394 Label L_index_ok;
395 __ cmpw(temp2_index, 0U);
396 __ br(Assembler::GE, L_index_ok);
397 __ hlt(0);
398 __ BIND(L_index_ok);
399 }
400
401 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
402 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
403
404 // get target Method* & entry point
405 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rmethod);
406 break;
407 }
408
409 case vmIntrinsics::_linkToInterface:
410 {
411 // same as TemplateTable::invokeinterface
412 // (minus the CP setup and profiling, with different argument motion)
413 if (VerifyMethodHandles) {
414 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
415 }
416
417 Register temp3_intf = temp3;
418 __ load_heap_oop(temp3_intf, member_clazz, temp2, rscratch2);
419 load_klass_from_Class(_masm, temp3_intf);
420 __ verify_klass_ptr(temp3_intf);
421
422 Register rindex = rmethod;
423 __ access_load_at(T_ADDRESS, IN_HEAP, rindex, member_vmindex, noreg, noreg);
424 if (VerifyMethodHandles) {
425 Label L;
426 __ cmpw(rindex, 0U);
427 __ br(Assembler::GE, L);
428 __ hlt(0);
429 __ bind(L);
430 }
431
432 // given intf, index, and recv klass, dispatch to the implementation method
433 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
434 // note: next two args must be the same:
435 rindex, rmethod,
436 temp2,
437 L_incompatible_class_change_error);
438 break;
439 }
440
441 default:
442 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
443 break;
444 }
445
446 // live at this point: rmethod, r19_sender_sp (if interpreted)
447
448 // After figuring out which concrete method to call, jump into it.
449 // Note that this works in the interpreter with no data motion.
450 // But the compiled version will require that r2_recv be shifted out.
451 __ verify_method_ptr(rmethod);
452 jump_from_method_handle(_masm, rmethod, temp1, for_compiler_entry);
453 if (iid == vmIntrinsics::_linkToInterface) {
454 __ bind(L_incompatible_class_change_error);
455 __ far_jump(RuntimeAddress(SharedRuntime::throw_IncompatibleClassChangeError_entry()));
456 }
457 }
458 }
459
460 #ifndef PRODUCT
461 void trace_method_handle_stub(const char* adaptername,
462 oopDesc* mh,
463 intptr_t* saved_regs,
464 intptr_t* entry_sp) { }
465
466 // The stub wraps the arguments in a struct on the stack to avoid
467 // dealing with the different calling conventions for passing 6
468 // arguments.
469 struct MethodHandleStubArguments {
470 const char* adaptername;
471 oopDesc* mh;
472 intptr_t* saved_regs;
473 intptr_t* entry_sp;
474 };
475 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { }
476
477 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { }
478 #endif //PRODUCT