1 /* 2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "asm/macroAssembler.hpp" 27 #include "classfile/vmClasses.hpp" 28 #include "compiler/disassembler.hpp" 29 #include "classfile/javaClasses.inline.hpp" 30 #include "interpreter/interpreter.hpp" 31 #include "interpreter/interpreterRuntime.hpp" 32 #include "jvm.h" 33 #include "logging/log.hpp" 34 #include "logging/logStream.hpp" 35 #include "memory/allocation.inline.hpp" 36 #include "memory/resourceArea.hpp" 37 #include "prims/jvmtiExport.hpp" 38 #include "prims/methodHandles.hpp" 39 #include "runtime/flags/flagSetting.hpp" 40 #include "runtime/frame.inline.hpp" 41 #include "runtime/stubRoutines.hpp" 42 #include "utilities/formatBuffer.hpp" 43 #include "utilities/preserveException.hpp" 44 45 #define __ Disassembler::hook<MacroAssembler>(__FILE__, __LINE__, _masm)-> 46 47 #ifdef PRODUCT 48 #define BLOCK_COMMENT(str) /* nothing */ 49 #define STOP(error) stop(error) 50 #else 51 #define BLOCK_COMMENT(str) __ block_comment(str) 52 #define STOP(error) block_comment(error); __ stop(error) 53 #endif 54 55 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":") 56 57 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg) { 58 if (VerifyMethodHandles) 59 verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class), 60 "MH argument is a Class"); 61 __ movptr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset())); 62 } 63 64 #ifdef ASSERT 65 static int check_nonzero(const char* xname, int x) { 66 assert(x != 0, "%s should be nonzero", xname); 67 return x; 68 } 69 #define NONZERO(x) check_nonzero(#x, x) 70 #else //ASSERT 71 #define NONZERO(x) (x) 72 #endif //ASSERT 73 74 #ifdef ASSERT 75 void MethodHandles::verify_klass(MacroAssembler* _masm, 76 Register obj, vmClassID klass_id, 77 const char* error_message) { 78 InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id); 79 Klass* klass = vmClasses::klass_at(klass_id); 80 Register temp = rdi; 81 Label L_ok, L_bad; 82 BLOCK_COMMENT("verify_klass {"); 83 __ verify_oop(obj); 84 __ testptr(obj, obj); 85 __ jcc(Assembler::zero, L_bad); 86 #define PUSH { __ push(temp); LP64_ONLY( __ push(rscratch1); ) } 87 #define POP { LP64_ONLY( __ pop(rscratch1); ) __ pop(temp); } 88 PUSH; 89 __ load_klass(temp, obj, rscratch1); 90 __ cmpptr(temp, ExternalAddress((address) klass_addr), rscratch1); 91 __ jcc(Assembler::equal, L_ok); 92 intptr_t super_check_offset = klass->super_check_offset(); 93 __ movptr(temp, Address(temp, super_check_offset)); 94 __ cmpptr(temp, ExternalAddress((address) klass_addr), rscratch1); 95 __ jcc(Assembler::equal, L_ok); 96 POP; 97 __ bind(L_bad); 98 __ STOP(error_message); 99 __ BIND(L_ok); 100 POP; 101 BLOCK_COMMENT("} verify_klass"); 102 #undef POP 103 #undef PUSH 104 } 105 106 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) { 107 Label L; 108 BLOCK_COMMENT("verify_ref_kind {"); 109 __ movl(temp, Address(member_reg, NONZERO(java_lang_invoke_MemberName::flags_offset()))); 110 __ shrl(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT); 111 __ andl(temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK); 112 __ cmpl(temp, ref_kind); 113 __ jcc(Assembler::equal, L); 114 { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal); 115 jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind); 116 if (ref_kind == JVM_REF_invokeVirtual || 117 ref_kind == JVM_REF_invokeSpecial) 118 // could do this for all ref_kinds, but would explode assembly code size 119 trace_method_handle(_masm, buf); 120 __ STOP(buf); 121 } 122 BLOCK_COMMENT("} verify_ref_kind"); 123 __ bind(L); 124 } 125 126 #endif //ASSERT 127 128 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp, 129 bool for_compiler_entry) { 130 assert(method == rbx, "interpreter calling convention"); 131 132 Label L_no_such_method; 133 __ testptr(rbx, rbx); 134 __ jcc(Assembler::zero, L_no_such_method); 135 136 __ verify_method_ptr(method); 137 138 if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) { 139 Label run_compiled_code; 140 // JVMTI events, such as single-stepping, are implemented partly by avoiding running 141 // compiled code in threads for which the event is enabled. Check here for 142 // interp_only_mode if these events CAN be enabled. 143 #ifdef _LP64 144 Register rthread = r15_thread; 145 #else 146 Register rthread = temp; 147 __ get_thread(rthread); 148 #endif 149 // interp_only is an int, on little endian it is sufficient to test the byte only 150 // Is a cmpl faster? 151 __ cmpb(Address(rthread, JavaThread::interp_only_mode_offset()), 0); 152 __ jccb(Assembler::zero, run_compiled_code); 153 __ jmp(Address(method, Method::interpreter_entry_offset())); 154 __ BIND(run_compiled_code); 155 } 156 157 const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() : 158 Method::from_interpreted_offset(); 159 __ jmp(Address(method, entry_offset)); 160 161 __ bind(L_no_such_method); 162 __ jump(RuntimeAddress(SharedRuntime::throw_AbstractMethodError_entry())); 163 } 164 165 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm, 166 Register recv, Register method_temp, 167 Register temp2, 168 bool for_compiler_entry) { 169 BLOCK_COMMENT("jump_to_lambda_form {"); 170 // This is the initial entry point of a lazy method handle. 171 // After type checking, it picks up the invoker from the LambdaForm. 172 assert_different_registers(recv, method_temp, temp2); 173 assert(recv != noreg, "required register"); 174 assert(method_temp == rbx, "required register for loading method"); 175 176 // Load the invoker, as MH -> MH.form -> LF.vmentry 177 __ verify_oop(recv); 178 __ load_heap_oop(method_temp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset())), temp2); 179 __ verify_oop(method_temp); 180 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset())), temp2); 181 __ verify_oop(method_temp); 182 __ load_heap_oop(method_temp, Address(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset())), temp2); 183 __ verify_oop(method_temp); 184 __ access_load_at(T_ADDRESS, IN_HEAP, method_temp, 185 Address(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())), 186 noreg, noreg); 187 188 if (VerifyMethodHandles && !for_compiler_entry) { 189 // make sure recv is already on stack 190 __ movptr(temp2, Address(method_temp, Method::const_offset())); 191 __ load_sized_value(temp2, 192 Address(temp2, ConstMethod::size_of_parameters_offset()), 193 sizeof(u2), /*is_signed*/ false); 194 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), ""); 195 Label L; 196 __ cmpoop(recv, __ argument_address(temp2, -1)); 197 __ jcc(Assembler::equal, L); 198 __ movptr(rax, __ argument_address(temp2, -1)); 199 __ STOP("receiver not on stack"); 200 __ BIND(L); 201 } 202 203 jump_from_method_handle(_masm, method_temp, temp2, for_compiler_entry); 204 BLOCK_COMMENT("} jump_to_lambda_form"); 205 } 206 207 void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) { 208 BLOCK_COMMENT("jump_to_native_invoker {"); 209 assert_different_registers(nep_reg, temp_target); 210 assert(nep_reg != noreg, "required register"); 211 212 // Load the invoker, as NEP -> .invoker 213 __ verify_oop(nep_reg); 214 __ access_load_at(T_ADDRESS, IN_HEAP, temp_target, 215 Address(nep_reg, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes())), 216 noreg, noreg); 217 218 __ jmp(temp_target); 219 BLOCK_COMMENT("} jump_to_native_invoker"); 220 } 221 222 223 // Code generation 224 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm, 225 vmIntrinsics::ID iid) { 226 const bool not_for_compiler_entry = false; // this is the interpreter entry 227 assert(is_signature_polymorphic(iid), "expected invoke iid"); 228 if (iid == vmIntrinsics::_invokeGeneric || 229 iid == vmIntrinsics::_compiledLambdaForm) { 230 // Perhaps surprisingly, the symbolic references visible to Java are not directly used. 231 // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod. 232 // They all allow an appendix argument. 233 __ hlt(); // empty stubs make SG sick 234 return nullptr; 235 } 236 237 // No need in interpreter entry for linkToNative for now. 238 // Interpreter calls compiled entry through i2c. 239 if (iid == vmIntrinsics::_linkToNative) { 240 __ hlt(); 241 return nullptr; 242 } 243 244 // rsi/r13: sender SP (must preserve; see prepare_to_jump_from_interpreted) 245 // rbx: Method* 246 // rdx: argument locator (parameter slot count, added to rsp) 247 // rcx: used as temp to hold mh or receiver 248 // rax, rdi: garbage temps, blown away 249 Register rdx_argp = rdx; // argument list ptr, live on error paths 250 Register rax_temp = rax; 251 Register rcx_mh = rcx; // MH receiver; dies quickly and is recycled 252 Register rbx_method = rbx; // eventual target of this invocation 253 254 // here's where control starts out: 255 __ align(CodeEntryAlignment); 256 address entry_point = __ pc(); 257 258 if (VerifyMethodHandles) { 259 assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2"); 260 261 Label L; 262 BLOCK_COMMENT("verify_intrinsic_id {"); 263 __ cmpw(Address(rbx_method, Method::intrinsic_id_offset()), (int) iid); 264 __ jcc(Assembler::equal, L); 265 if (iid == vmIntrinsics::_linkToVirtual || 266 iid == vmIntrinsics::_linkToSpecial) { 267 // could do this for all kinds, but would explode assembly code size 268 trace_method_handle(_masm, "bad Method*::intrinsic_id"); 269 } 270 __ STOP("bad Method*::intrinsic_id"); 271 __ bind(L); 272 BLOCK_COMMENT("} verify_intrinsic_id"); 273 } 274 275 // First task: Find out how big the argument list is. 276 Address rdx_first_arg_addr; 277 int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid); 278 assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic"); 279 if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) { 280 __ movptr(rdx_argp, Address(rbx_method, Method::const_offset())); 281 __ load_sized_value(rdx_argp, 282 Address(rdx_argp, ConstMethod::size_of_parameters_offset()), 283 sizeof(u2), /*is_signed*/ false); 284 // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), ""); 285 rdx_first_arg_addr = __ argument_address(rdx_argp, -1); 286 } else { 287 DEBUG_ONLY(rdx_argp = noreg); 288 } 289 290 if (!is_signature_polymorphic_static(iid)) { 291 __ movptr(rcx_mh, rdx_first_arg_addr); 292 DEBUG_ONLY(rdx_argp = noreg); 293 } 294 295 // rdx_first_arg_addr is live! 296 297 trace_method_handle_interpreter_entry(_masm, iid); 298 299 if (iid == vmIntrinsics::_invokeBasic) { 300 generate_method_handle_dispatch(_masm, iid, rcx_mh, noreg, not_for_compiler_entry); 301 302 } else { 303 // Adjust argument list by popping the trailing MemberName argument. 304 Register rcx_recv = noreg; 305 if (MethodHandles::ref_kind_has_receiver(ref_kind)) { 306 // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack. 307 __ movptr(rcx_recv = rcx, rdx_first_arg_addr); 308 } 309 DEBUG_ONLY(rdx_argp = noreg); 310 Register rbx_member = rbx_method; // MemberName ptr; incoming method ptr is dead now 311 __ pop(rax_temp); // return address 312 __ pop(rbx_member); // extract last argument 313 __ push(rax_temp); // re-push return address 314 generate_method_handle_dispatch(_masm, iid, rcx_recv, rbx_member, not_for_compiler_entry); 315 } 316 317 return entry_point; 318 } 319 320 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm, 321 vmIntrinsics::ID iid, 322 Register receiver_reg, 323 Register member_reg, 324 bool for_compiler_entry) { 325 assert(is_signature_polymorphic(iid), "expected invoke iid"); 326 Register rbx_method = rbx; // eventual target of this invocation 327 // temps used in this code are not used in *either* compiled or interpreted calling sequences 328 #ifdef _LP64 329 Register temp1 = rscratch1; 330 Register temp2 = rscratch2; 331 Register temp3 = rax; 332 if (for_compiler_entry) { 333 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : j_rarg0), "only valid assignment"); 334 assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5); 335 assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5); 336 assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5); 337 } 338 #else 339 Register temp1 = (for_compiler_entry ? rsi : rdx); 340 Register temp2 = rdi; 341 Register temp3 = rax; 342 if (for_compiler_entry) { 343 assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic || iid == vmIntrinsics::_linkToNative ? noreg : rcx), "only valid assignment"); 344 assert_different_registers(temp1, rcx, rdx); 345 assert_different_registers(temp2, rcx, rdx); 346 assert_different_registers(temp3, rcx, rdx); 347 } 348 #endif 349 else { 350 assert_different_registers(temp1, temp2, temp3, saved_last_sp_register()); // don't trash lastSP 351 } 352 assert_different_registers(temp1, temp2, temp3, receiver_reg); 353 assert_different_registers(temp1, temp2, temp3, member_reg); 354 355 if (iid == vmIntrinsics::_invokeBasic) { 356 // indirect through MH.form.vmentry.vmtarget 357 jump_to_lambda_form(_masm, receiver_reg, rbx_method, temp1, for_compiler_entry); 358 } else if (iid == vmIntrinsics::_linkToNative) { 359 assert(for_compiler_entry, "only compiler entry is supported"); 360 jump_to_native_invoker(_masm, member_reg, temp1); 361 } else { 362 // The method is a member invoker used by direct method handles. 363 if (VerifyMethodHandles) { 364 // make sure the trailing argument really is a MemberName (caller responsibility) 365 verify_klass(_masm, member_reg, VM_CLASS_ID(java_lang_invoke_MemberName), 366 "MemberName required for invokeVirtual etc."); 367 } 368 369 Address member_clazz( member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset())); 370 Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset())); 371 Address member_vmtarget( member_reg, NONZERO(java_lang_invoke_MemberName::method_offset())); 372 Address vmtarget_method( rbx_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset())); 373 374 Register temp1_recv_klass = temp1; 375 if (iid != vmIntrinsics::_linkToStatic) { 376 __ verify_oop(receiver_reg); 377 if (iid == vmIntrinsics::_linkToSpecial) { 378 // Don't actually load the klass; just null-check the receiver. 379 __ null_check(receiver_reg); 380 } else { 381 // load receiver klass itself 382 __ load_klass(temp1_recv_klass, receiver_reg, temp2); 383 __ verify_klass_ptr(temp1_recv_klass); 384 } 385 BLOCK_COMMENT("check_receiver {"); 386 // The receiver for the MemberName must be in receiver_reg. 387 // Check the receiver against the MemberName.clazz 388 if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) { 389 // Did not load it above... 390 __ load_klass(temp1_recv_klass, receiver_reg, temp2); 391 __ verify_klass_ptr(temp1_recv_klass); 392 } 393 if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) { 394 Label L_ok; 395 Register temp2_defc = temp2; 396 __ load_heap_oop(temp2_defc, member_clazz, temp3); 397 load_klass_from_Class(_masm, temp2_defc); 398 __ verify_klass_ptr(temp2_defc); 399 __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, L_ok); 400 // If we get here, the type check failed! 401 __ STOP("receiver class disagrees with MemberName.clazz"); 402 __ bind(L_ok); 403 } 404 BLOCK_COMMENT("} check_receiver"); 405 } 406 if (iid == vmIntrinsics::_linkToSpecial || 407 iid == vmIntrinsics::_linkToStatic) { 408 DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass 409 } 410 411 // Live registers at this point: 412 // member_reg - MemberName that was the trailing argument 413 // temp1_recv_klass - klass of stacked receiver, if needed 414 // rsi/r13 - interpreter linkage (if interpreted) 415 // rcx, rdx, rsi, rdi, r8 - compiler arguments (if compiled) 416 417 Label L_incompatible_class_change_error; 418 switch (iid) { 419 case vmIntrinsics::_linkToSpecial: 420 if (VerifyMethodHandles) { 421 verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3); 422 } 423 __ load_heap_oop(rbx_method, member_vmtarget); 424 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_method, vmtarget_method, noreg, noreg); 425 break; 426 427 case vmIntrinsics::_linkToStatic: 428 if (VerifyMethodHandles) { 429 verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3); 430 } 431 __ load_heap_oop(rbx_method, member_vmtarget); 432 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_method, vmtarget_method, noreg, noreg); 433 break; 434 435 case vmIntrinsics::_linkToVirtual: 436 { 437 // same as TemplateTable::invokevirtual, 438 // minus the CP setup and profiling: 439 440 if (VerifyMethodHandles) { 441 verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3); 442 } 443 444 // pick out the vtable index from the MemberName, and then we can discard it: 445 Register temp2_index = temp2; 446 __ access_load_at(T_ADDRESS, IN_HEAP, temp2_index, member_vmindex, noreg, noreg); 447 448 if (VerifyMethodHandles) { 449 Label L_index_ok; 450 __ cmpl(temp2_index, 0); 451 __ jcc(Assembler::greaterEqual, L_index_ok); 452 __ STOP("no virtual index"); 453 __ BIND(L_index_ok); 454 } 455 456 // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget 457 // at this point. And VerifyMethodHandles has already checked clazz, if needed. 458 459 // get target Method* & entry point 460 __ lookup_virtual_method(temp1_recv_klass, temp2_index, rbx_method); 461 break; 462 } 463 464 case vmIntrinsics::_linkToInterface: 465 { 466 // same as TemplateTable::invokeinterface 467 // (minus the CP setup and profiling, with different argument motion) 468 if (VerifyMethodHandles) { 469 verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3); 470 } 471 472 Register temp3_intf = temp3; 473 __ load_heap_oop(temp3_intf, member_clazz); 474 load_klass_from_Class(_masm, temp3_intf); 475 __ verify_klass_ptr(temp3_intf); 476 477 Register rbx_index = rbx_method; 478 __ access_load_at(T_ADDRESS, IN_HEAP, rbx_index, member_vmindex, noreg, noreg); 479 if (VerifyMethodHandles) { 480 Label L; 481 __ cmpl(rbx_index, 0); 482 __ jcc(Assembler::greaterEqual, L); 483 __ STOP("invalid vtable index for MH.invokeInterface"); 484 __ bind(L); 485 } 486 487 // given intf, index, and recv klass, dispatch to the implementation method 488 __ lookup_interface_method(temp1_recv_klass, temp3_intf, 489 // note: next two args must be the same: 490 rbx_index, rbx_method, 491 temp2, 492 L_incompatible_class_change_error); 493 break; 494 } 495 496 default: 497 fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid)); 498 break; 499 } 500 501 // Live at this point: 502 // rbx_method 503 // rsi/r13 (if interpreted) 504 505 // After figuring out which concrete method to call, jump into it. 506 // Note that this works in the interpreter with no data motion. 507 // But the compiled version will require that rcx_recv be shifted out. 508 __ verify_method_ptr(rbx_method); 509 jump_from_method_handle(_masm, rbx_method, temp1, for_compiler_entry); 510 511 if (iid == vmIntrinsics::_linkToInterface) { 512 __ bind(L_incompatible_class_change_error); 513 __ jump(RuntimeAddress(SharedRuntime::throw_IncompatibleClassChangeError_entry())); 514 } 515 } 516 } 517 518 #ifndef PRODUCT 519 void trace_method_handle_stub(const char* adaptername, 520 oopDesc* mh, 521 intptr_t* saved_regs, 522 intptr_t* entry_sp) { 523 // called as a leaf from native code: do not block the JVM! 524 bool has_mh = (strstr(adaptername, "/static") == nullptr && 525 strstr(adaptername, "linkTo") == nullptr); // static linkers don't have MH 526 const char* mh_reg_name = has_mh ? "rcx_mh" : "rcx"; 527 log_info(methodhandles)("MH %s %s=" PTR_FORMAT " sp=" PTR_FORMAT, adaptername, mh_reg_name, p2i(mh), p2i(entry_sp)); 528 529 LogTarget(Trace, methodhandles) lt; 530 if (lt.is_enabled()) { 531 ResourceMark rm; 532 LogStream ls(lt); 533 ls.print_cr("Registers:"); 534 const int saved_regs_count = Register::number_of_registers; 535 for (int i = 0; i < saved_regs_count; i++) { 536 Register r = as_Register(i); 537 // The registers are stored in reverse order on the stack (by pusha). 538 #ifdef AMD64 539 int num_regs = UseAPX ? 32 : 16; 540 assert(Register::available_gp_registers() == num_regs, "sanity"); 541 if (r == rsp) { 542 // rsp is actually not stored by pusha(), compute the old rsp from saved_regs (rsp after pusha): saved_regs + 16 = old rsp 543 ls.print("%3s=" PTR_FORMAT, r->name(), (intptr_t)(&saved_regs[num_regs])); 544 } else { 545 ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[((saved_regs_count - 1) - i)]); 546 } 547 #else 548 ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[((saved_regs_count - 1) - i)]); 549 #endif 550 if ((i + 1) % 4 == 0) { 551 ls.cr(); 552 } else { 553 ls.print(", "); 554 } 555 } 556 ls.cr(); 557 558 // Note: We want to allow trace_method_handle from any call site. 559 // While trace_method_handle creates a frame, it may be entered 560 // without a PC on the stack top (e.g. not just after a call). 561 // Walking that frame could lead to failures due to that invalid PC. 562 // => carefully detect that frame when doing the stack walking 563 564 { 565 // dumping last frame with frame::describe 566 567 JavaThread* p = JavaThread::active(); 568 569 // may not be needed by safer and unexpensive here 570 PreserveExceptionMark pem(Thread::current()); 571 FrameValues values; 572 573 frame cur_frame = os::current_frame(); 574 575 if (cur_frame.fp() != nullptr) { // not walkable 576 577 // Robust search of trace_calling_frame (independent of inlining). 578 // Assumes saved_regs comes from a pusha in the trace_calling_frame. 579 // 580 // We have to start the search from cur_frame, because trace_calling_frame may be it. 581 // It is guaranteed that trace_calling_frame is different from the top frame. 582 // But os::current_frame() does NOT return the top frame: it returns the next frame under it (caller's frame). 583 // (Due to inlining and tail call optimizations, caller's frame doesn't necessarily correspond to the immediate 584 // caller in the source code.) 585 assert(cur_frame.sp() < saved_regs, "registers not saved on stack ?"); 586 frame trace_calling_frame = cur_frame; 587 while (trace_calling_frame.fp() < saved_regs) { 588 assert(trace_calling_frame.cb() == nullptr, "not a C frame"); 589 trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame); 590 } 591 assert(trace_calling_frame.sp() < saved_regs, "wrong frame"); 592 593 // safely create a frame and call frame::describe 594 intptr_t *dump_sp = trace_calling_frame.sender_sp(); 595 intptr_t *dump_fp = trace_calling_frame.link(); 596 597 if (has_mh) { 598 // The previous definition of walkable may have to be refined 599 // if new call sites cause the next frame constructor to start 600 // failing. Alternatively, frame constructors could be 601 // modified to support the current or future non walkable 602 // frames (but this is more intrusive and is not considered as 603 // part of this RFE, which will instead use a simpler output). 604 frame dump_frame = frame(dump_sp, dump_fp); 605 dump_frame.describe(values, 1); 606 } else { 607 // Stack may not be walkable (invalid PC above FP): 608 // Add descriptions without building a Java frame to avoid issues 609 values.describe(-1, dump_fp, "fp for #1 <not parsed, cannot trust pc>"); 610 values.describe(-1, dump_sp, "sp for #1"); 611 } 612 } 613 values.describe(-1, entry_sp, "raw top of stack"); 614 615 ls.print_cr("Stack layout:"); 616 values.print_on(p, &ls); 617 } 618 if (has_mh && oopDesc::is_oop(mh)) { 619 mh->print_on(&ls); 620 if (java_lang_invoke_MethodHandle::is_instance(mh)) { 621 java_lang_invoke_MethodHandle::form(mh)->print_on(&ls); 622 } 623 } 624 } 625 } 626 627 // The stub wraps the arguments in a struct on the stack to avoid 628 // dealing with the different calling conventions for passing 6 629 // arguments. 630 struct MethodHandleStubArguments { 631 const char* adaptername; 632 oopDesc* mh; 633 intptr_t* saved_regs; 634 intptr_t* entry_sp; 635 }; 636 void trace_method_handle_stub_wrapper(MethodHandleStubArguments* args) { 637 trace_method_handle_stub(args->adaptername, 638 args->mh, 639 args->saved_regs, 640 args->entry_sp); 641 } 642 643 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { 644 if (!log_is_enabled(Info, methodhandles)) return; 645 BLOCK_COMMENT(err_msg("trace_method_handle %s {", adaptername)); 646 __ enter(); 647 __ andptr(rsp, -16); // align stack if needed for FPU state 648 __ pusha(); 649 __ mov(rbx, rsp); // for retrieving saved_regs 650 // Note: saved_regs must be in the entered frame for the 651 // robust stack walking implemented in trace_method_handle_stub. 652 653 // save FP result, valid at some call sites (adapter_opt_return_float, ...) 654 __ decrement(rsp, 2 * wordSize); 655 #ifdef _LP64 656 __ movdbl(Address(rsp, 0), xmm0); 657 #else 658 if (UseSSE >= 2) { 659 __ movdbl(Address(rsp, 0), xmm0); 660 } else if (UseSSE == 1) { 661 __ movflt(Address(rsp, 0), xmm0); 662 } else { 663 __ fst_d(Address(rsp, 0)); 664 } 665 #endif // LP64 666 667 // Incoming state: 668 // rcx: method handle 669 // 670 // To avoid calling convention issues, build a record on the stack 671 // and pass the pointer to that instead. 672 __ push(rbp); // entry_sp (with extra align space) 673 __ push(rbx); // pusha saved_regs 674 __ push(rcx); // mh 675 __ push(rcx); // slot for adaptername 676 __ movptr(Address(rsp, 0), (intptr_t) adaptername, rscratch1); 677 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub_wrapper), rsp); 678 __ increment(rsp, sizeof(MethodHandleStubArguments)); 679 680 #ifdef _LP64 681 __ movdbl(xmm0, Address(rsp, 0)); 682 #else 683 if (UseSSE >= 2) { 684 __ movdbl(xmm0, Address(rsp, 0)); 685 } else if (UseSSE == 1) { 686 __ movflt(xmm0, Address(rsp, 0)); 687 } else { 688 __ fld_d(Address(rsp, 0)); 689 } 690 #endif // LP64 691 __ increment(rsp, 2 * wordSize); 692 693 __ popa(); 694 __ leave(); 695 BLOCK_COMMENT("} trace_method_handle"); 696 } 697 #endif //PRODUCT