1 /*
2 * Copyright (c) 1997, 2021, 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 "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 __ _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 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
119 Method::from_interpreted_offset();
120 __ ldr(rscratch1,Address(method, entry_offset));
121 __ br(rscratch1);
122 __ bind(L_no_such_method);
123 __ far_jump(RuntimeAddress(StubRoutines::throw_AbstractMethodError_entry()));
124 }
125
126 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
127 Register recv, Register method_temp,
128 Register temp2,
129 bool for_compiler_entry) {
130 BLOCK_COMMENT("jump_to_lambda_form {");
131 // This is the initial entry point of a lazy method handle.
132 // After type checking, it picks up the invoker from the LambdaForm.
133 assert_different_registers(recv, method_temp, temp2);
134 assert(recv != noreg, "required register");
135 assert(method_temp == rmethod, "required register for loading method");
136
137 // Load the invoker, as MH -> MH.form -> LF.vmentry
138 __ verify_oop(recv);
139 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2);
140 __ verify_oop(method_temp);
141 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2);
142 __ verify_oop(method_temp);
143 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2);
144 __ verify_oop(method_temp);
145 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), noreg, noreg);
146
147 if (VerifyMethodHandles && !for_compiler_entry) {
148 // make sure recv is already on stack
149 __ ldr(temp2, Address(method_temp, Method::const_offset()));
150 __ load_sized_value(temp2,
151 Address(temp2, ConstMethod::size_of_parameters_offset()),
152 sizeof(u2), /*is_signed*/ false);
153 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
154 Label L;
155 __ ldr(rscratch1, __ argument_address(temp2, -1));
156 __ cmpoop(recv, rscratch1);
157 __ br(Assembler::EQ, L);
158 __ ldr(r0, __ argument_address(temp2, -1));
159 __ hlt(0);
160 __ BIND(L);
161 }
162
163 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry);
164 BLOCK_COMMENT("} jump_to_lambda_form");
165 }
166
167 // Code generation
168 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
169 vmIntrinsics::ID iid) {
170 const bool not_for_compiler_entry = false; // this is the interpreter entry
171 assert(is_signature_polymorphic(iid), "expected invoke iid");
172 if (iid == vmIntrinsics::_invokeGeneric ||
173 iid == vmIntrinsics::_compiledLambdaForm) {
174 // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
175 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
176 // They all allow an appendix argument.
177 __ hlt(0); // empty stubs make SG sick
178 return NULL;
179 }
180
181 // No need in interpreter entry for linkToNative for now.
182 // Interpreter calls compiled entry through i2c.
183 if (iid == vmIntrinsics::_linkToNative) {
184 __ hlt(0);
185 return NULL;
186 }
187
188 // r13: sender SP (must preserve; see prepare_to_jump_from_interpreted)
189 // rmethod: Method*
190 // r3: argument locator (parameter slot count, added to rsp)
191 // r1: used as temp to hold mh or receiver
192 // r0, r11: garbage temps, blown away
193 Register argp = r3; // argument list ptr, live on error paths
194 Register temp = r0;
195 Register mh = r1; // MH receiver; dies quickly and is recycled
196
197 // here's where control starts out:
198 __ align(CodeEntryAlignment);
199 address entry_point = __ pc();
200
201 if (VerifyMethodHandles) {
202 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2");
203
204 Label L;
205 BLOCK_COMMENT("verify_intrinsic_id {");
206 __ ldrh(rscratch1, Address(rmethod, Method::intrinsic_id_offset_in_bytes()));
207 __ subs(zr, rscratch1, (int) iid);
208 __ br(Assembler::EQ, L);
209 if (iid == vmIntrinsics::_linkToVirtual ||
210 iid == vmIntrinsics::_linkToSpecial) {
211 // could do this for all kinds, but would explode assembly code size
212 trace_method_handle(_masm, "bad Method*::intrinsic_id");
213 }
214 __ hlt(0);
215 __ bind(L);
216 BLOCK_COMMENT("} verify_intrinsic_id");
217 }
218
219 // First task: Find out how big the argument list is.
220 Address r3_first_arg_addr;
221 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
222 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
223 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
224 __ ldr(argp, Address(rmethod, Method::const_offset()));
225 __ load_sized_value(argp,
226 Address(argp, ConstMethod::size_of_parameters_offset()),
227 sizeof(u2), /*is_signed*/ false);
228 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
229 r3_first_arg_addr = __ argument_address(argp, -1);
230 } else {
231 DEBUG_ONLY(argp = noreg);
232 }
233
234 if (!is_signature_polymorphic_static(iid)) {
235 __ ldr(mh, r3_first_arg_addr);
236 DEBUG_ONLY(argp = noreg);
237 }
238
239 // r3_first_arg_addr is live!
240
241 trace_method_handle_interpreter_entry(_masm, iid);
242 if (iid == vmIntrinsics::_invokeBasic) {
243 generate_method_handle_dispatch(_masm, iid, mh, noreg, not_for_compiler_entry);
244
245 } else {
246 // Adjust argument list by popping the trailing MemberName argument.
247 Register recv = noreg;
248 if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
249 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
250 __ ldr(recv = r2, r3_first_arg_addr);
251 }
252 DEBUG_ONLY(argp = noreg);
253 Register rmember = rmethod; // MemberName ptr; incoming method ptr is dead now
254 __ pop(rmember); // extract last argument
255 generate_method_handle_dispatch(_masm, iid, recv, rmember, not_for_compiler_entry);
256 }
257
258 return entry_point;
259 }
260
261
262 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
263 vmIntrinsics::ID iid,
264 Register receiver_reg,
265 Register member_reg,
266 bool for_compiler_entry) {
267 assert(is_signature_polymorphic(iid), "expected invoke iid");
268 // temps used in this code are not used in *either* compiled or interpreted calling sequences
269 Register temp1 = r10;
270 Register temp2 = r11;
271 Register temp3 = r14; // r13 is live by this point: it contains the sender SP
272 if (for_compiler_entry) {
273 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : j_rarg0), "only valid assignment");
274 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
275 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
276 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
277 }
278
279 assert_different_registers(temp1, temp2, temp3, receiver_reg);
280 assert_different_registers(temp1, temp2, temp3, member_reg);
281
282 if (iid == vmIntrinsics::_invokeBasic || iid == vmIntrinsics::_linkToNative) {
283 if (iid == vmIntrinsics::_linkToNative) {
284 assert(for_compiler_entry, "only compiler entry is supported");
285 }
286 // indirect through MH.form.vmentry.vmtarget
287 jump_to_lambda_form(_masm, receiver_reg, rmethod, temp1, for_compiler_entry);
288
289 } else {
290 // The method is a member invoker used by direct method handles.
291 if (VerifyMethodHandles) {
292 // make sure the trailing argument really is a MemberName (caller responsibility)
293 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName),
294 "MemberName required for invokeVirtual etc.");
295 }
296
297 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset()));
298 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset()));
299 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset()));
300 Address vmtarget_method( rmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()));
301
302 Register temp1_recv_klass = temp1;
303 if (iid != vmIntrinsics::_linkToStatic) {
304 __ verify_oop(receiver_reg);
305 if (iid == vmIntrinsics::_linkToSpecial) {
306 // Don't actually load the klass; just null-check the receiver.
307 __ null_check(receiver_reg);
308 } else {
309 // load receiver klass itself
310 __ load_klass(temp1_recv_klass, receiver_reg, true);
311 __ verify_klass_ptr(temp1_recv_klass);
312 }
313 BLOCK_COMMENT("check_receiver {");
314 // The receiver for the MemberName must be in receiver_reg.
315 // Check the receiver against the MemberName.clazz
316 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
317 // Did not load it above...
318 __ load_klass(temp1_recv_klass, receiver_reg);
319 __ verify_klass_ptr(temp1_recv_klass);
320 }
321 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
322 Label L_ok;
323 Register temp2_defc = temp2;
324 __ load_heap_oop(temp2_defc, member_clazz, temp3);
325 load_klass_from_Class(_masm, temp2_defc);
326 __ verify_klass_ptr(temp2_defc);
327 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok);
328 // If we get here, the type check failed!
329 __ hlt(0);
330 // __ STOP("receiver class disagrees with MemberName.clazz");
331 __ bind(L_ok);
332 }
333 BLOCK_COMMENT("} check_receiver");
334 }
335 if (iid == vmIntrinsics::_linkToSpecial ||
336 iid == vmIntrinsics::_linkToStatic) {
337 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass
338 }
339
340 // Live registers at this point:
341 // member_reg - MemberName that was the trailing argument
342 // temp1_recv_klass - klass of stacked receiver, if needed
343 // r13 - interpreter linkage (if interpreted) ??? FIXME
344 // r1 ... r0 - compiler arguments (if compiled)
345
346 Label L_incompatible_class_change_error;
347 switch (iid) {
348 case vmIntrinsics::_linkToSpecial:
349 if (VerifyMethodHandles) {
350 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
351 }
352 __ load_heap_oop(rmethod, member_vmtarget);
353 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
354 break;
355
356 case vmIntrinsics::_linkToStatic:
357 if (VerifyMethodHandles) {
358 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
359 }
360 __ load_heap_oop(rmethod, member_vmtarget);
361 __ access_load_at(T_ADDRESS, IN_HEAP, rmethod, vmtarget_method, noreg, noreg);
362 break;
363
364 case vmIntrinsics::_linkToVirtual:
365 {
366 // same as TemplateTable::invokevirtual,
367 // minus the CP setup and profiling:
368
369 if (VerifyMethodHandles) {
370 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
371 }
372
373 // pick out the vtable index from the MemberName, and then we can discard it:
374 Register temp2_index = temp2;
375 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg);
376
377 if (VerifyMethodHandles) {
378 Label L_index_ok;
379 __ cmpw(temp2_index, 0U);
380 __ br(Assembler::GE, L_index_ok);
381 __ hlt(0);
382 __ BIND(L_index_ok);
383 }
384
385 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget
386 // at this point. And VerifyMethodHandles has already checked clazz, if needed.
387
388 // get target Method* & entry point
389 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rmethod);
390 break;
391 }
392
393 case vmIntrinsics::_linkToInterface:
394 {
395 // same as TemplateTable::invokeinterface
396 // (minus the CP setup and profiling, with different argument motion)
397 if (VerifyMethodHandles) {
398 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
399 }
400
401 Register temp3_intf = temp3;
402 __ load_heap_oop(temp3_intf, member_clazz);
403 load_klass_from_Class(_masm, temp3_intf);
404 __ verify_klass_ptr(temp3_intf);
405
406 Register rindex = rmethod;
407 __ access_load_at(T_ADDRESS, IN_HEAP, rindex, member_vmindex, noreg, noreg);
408 if (VerifyMethodHandles) {
409 Label L;
410 __ cmpw(rindex, 0U);
411 __ br(Assembler::GE, L);
412 __ hlt(0);
413 __ bind(L);
414 }
415
416 // given intf, index, and recv klass, dispatch to the implementation method
417 __ lookup_interface_method(temp1_recv_klass, temp3_intf,
418 // note: next two args must be the same:
419 rindex, rmethod,
420 temp2,
421 L_incompatible_class_change_error);
422 break;
423 }
424
425 default:
426 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid));
427 break;
428 }
429
430 // live at this point: rmethod, r13 (if interpreted)
431
432 // After figuring out which concrete method to call, jump into it.
433 // Note that this works in the interpreter with no data motion.
434 // But the compiled version will require that r2_recv be shifted out.
435 __ verify_method_ptr(rmethod);
436 jump_from_method_handle(_masm, rmethod, temp1, for_compiler_entry);
437 if (iid == vmIntrinsics::_linkToInterface) {
438 __ bind(L_incompatible_class_change_error);
439 __ far_jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
440 }
441 }
442 }
443
444 #ifndef PRODUCT
445 void trace_method_handle_stub(const char* adaptername,
446 oopDesc* mh,
447 intptr_t* saved_regs,
448 intptr_t* entry_sp) { }
449
450 // The stub wraps the arguments in a struct on the stack to avoid
451 // dealing with the different calling conventions for passing 6
452 // arguments.
453 struct MethodHandleStubArguments {
454 const char* adaptername;
455 oopDesc* mh;
456 intptr_t* saved_regs;
457 intptr_t* entry_sp;
458 };
459 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { }
460
461 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { }
462 #endif //PRODUCT