/* * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2012, 2025 SAP SE. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "asm/macroAssembler.inline.hpp" #include "classfile/javaClasses.inline.hpp" #include "classfile/vmClasses.hpp" #include "interpreter/interpreter.hpp" #include "jvm.h" #include "logging/log.hpp" #include "logging/logStream.hpp" #include "memory/allocation.inline.hpp" #include "memory/resourceArea.hpp" #include "prims/jvmtiExport.hpp" #include "prims/methodHandles.hpp" #include "runtime/frame.inline.hpp" #include "runtime/stubRoutines.hpp" #include "utilities/macros.hpp" #include "utilities/preserveException.hpp" #define __ _masm-> #ifdef PRODUCT #define BLOCK_COMMENT(str) // nothing #else #define BLOCK_COMMENT(str) __ block_comment(str) #endif #define BIND(label) bind(label); BLOCK_COMMENT(#label ":") // Workaround for C++ overloading nastiness on '0' for RegisterOrConstant. inline static RegisterOrConstant constant(int value) { return RegisterOrConstant(value); } void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg, Register temp_reg, Register temp2_reg) { if (VerifyMethodHandles) { verify_klass(_masm, klass_reg, VM_CLASS_ID(java_lang_Class), temp_reg, temp2_reg, "MH argument is a Class"); } __ ld(klass_reg, java_lang_Class::klass_offset(), klass_reg); } #ifdef ASSERT static int check_nonzero(const char* xname, int x) { assert(x != 0, "%s should be nonzero", xname); return x; } #define NONZERO(x) check_nonzero(#x, x) #else //ASSERT #define NONZERO(x) (x) #endif //ASSERT #ifdef ASSERT void MethodHandles::verify_klass(MacroAssembler* _masm, Register obj_reg, vmClassID klass_id, Register temp_reg, Register temp2_reg, const char* error_message) { InstanceKlass** klass_addr = vmClasses::klass_addr_at(klass_id); Klass* klass = vmClasses::klass_at(klass_id); Label L_ok, L_bad; BLOCK_COMMENT("verify_klass {"); __ verify_oop(obj_reg, FILE_AND_LINE); __ cmpdi(CR0, obj_reg, 0); __ beq(CR0, L_bad); __ load_klass(temp_reg, obj_reg); __ load_const_optimized(temp2_reg, (address) klass_addr); __ ld(temp2_reg, 0, temp2_reg); __ cmpd(CR0, temp_reg, temp2_reg); __ beq(CR0, L_ok); __ ld(temp_reg, klass->super_check_offset(), temp_reg); __ cmpd(CR0, temp_reg, temp2_reg); __ beq(CR0, L_ok); __ BIND(L_bad); __ stop(error_message); __ BIND(L_ok); BLOCK_COMMENT("} verify_klass"); } void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) { Label L; BLOCK_COMMENT("verify_ref_kind {"); __ load_sized_value(temp, NONZERO(java_lang_invoke_MemberName::flags_offset()), member_reg, sizeof(u4), /*is_signed*/ false); // assert(sizeof(u4) == sizeof(java.lang.invoke.MemberName.flags), ""); __ srwi( temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT); __ andi(temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK); __ cmpwi(CR1, temp, ref_kind); __ beq(CR1, L); { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal); jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind); if (ref_kind == JVM_REF_invokeVirtual || ref_kind == JVM_REF_invokeSpecial) // could do this for all ref_kinds, but would explode assembly code size trace_method_handle(_masm, buf); __ stop(buf); } BLOCK_COMMENT("} verify_ref_kind"); __ BIND(L); } #endif // ASSERT void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, Register method, Register target, Register temp, bool for_compiler_entry) { Label L_no_such_method; assert(method == R19_method, "interpreter calling convention"); assert_different_registers(method, target, temp); if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) { Label run_compiled_code; // JVMTI events, such as single-stepping, are implemented partly by avoiding running // compiled code in threads for which the event is enabled. Check here for // interp_only_mode if these events CAN be enabled. __ lwz(temp, in_bytes(JavaThread::interp_only_mode_offset()), R16_thread); __ cmplwi(CR0, temp, 0); __ beq(CR0, run_compiled_code); // Null method test is replicated below in compiled case. __ cmplwi(CR0, R19_method, 0); __ beq(CR0, L_no_such_method); __ ld(target, in_bytes(Method::interpreter_entry_offset()), R19_method); __ mtctr(target); __ bctr(); __ BIND(run_compiled_code); } // Compiled case, either static or fall-through from runtime conditional __ cmplwi(CR0, R19_method, 0); __ beq(CR0, L_no_such_method); const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() : Method::from_interpreted_offset(); __ ld(target, in_bytes(entry_offset), R19_method); __ mtctr(target); __ bctr(); __ bind(L_no_such_method); assert(SharedRuntime::throw_AbstractMethodError_entry() != nullptr, "not yet generated!"); __ load_const_optimized(target, SharedRuntime::throw_AbstractMethodError_entry()); __ mtctr(target); __ bctr(); } void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm, Register recv, Register method_temp, Register temp2, Register temp3, bool for_compiler_entry) { BLOCK_COMMENT("jump_to_lambda_form {"); // This is the initial entry point of a lazy method handle. // After type checking, it picks up the invoker from the LambdaForm. assert_different_registers(recv, method_temp, temp2, temp3); assert(method_temp == R19_method, "required register for loading method"); // Load the invoker, as MH -> MH.form -> LF.vmentry __ verify_oop(recv, FILE_AND_LINE); const MacroAssembler::PreservationLevel preservation_level = for_compiler_entry ? MacroAssembler::PRESERVATION_FRAME_LR_GP_FP_REGS : MacroAssembler::PRESERVATION_FRAME_LR; __ load_heap_oop(method_temp, NONZERO(java_lang_invoke_MethodHandle::form_offset()), recv, temp2, temp3, preservation_level, IS_NOT_NULL); __ verify_oop(method_temp, FILE_AND_LINE); __ load_heap_oop(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset()), method_temp, temp2, temp3, preservation_level, IS_NOT_NULL); __ verify_oop(method_temp, FILE_AND_LINE); __ load_heap_oop(method_temp, NONZERO(java_lang_invoke_MemberName::method_offset()), method_temp, temp2, temp3, preservation_level, IS_NOT_NULL); __ verify_oop(method_temp, FILE_AND_LINE); __ ld(method_temp, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()), method_temp); if (VerifyMethodHandles && !for_compiler_entry) { // Make sure recv is already on stack. __ ld(temp2, in_bytes(Method::const_offset()), method_temp); __ load_sized_value(temp2, in_bytes(ConstMethod::size_of_parameters_offset()), temp2, sizeof(u2), /*is_signed*/ false); // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), ""); Label L; __ ld(temp2, __ argument_offset(temp2, temp2, 0), R15_esp); __ cmpd(CR1, temp2, recv); __ beq(CR1, L); __ stop("receiver not on stack"); __ BIND(L); } jump_from_method_handle(_masm, method_temp, temp2, temp3, for_compiler_entry); BLOCK_COMMENT("} jump_to_lambda_form"); } // Code generation address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid) { const bool not_for_compiler_entry = false; // this is the interpreter entry assert(is_signature_polymorphic(iid), "expected invoke iid"); if (iid == vmIntrinsics::_invokeGeneric || iid == vmIntrinsics::_compiledLambdaForm) { // Perhaps surprisingly, the symbolic references visible to Java are not directly used. // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod. // They all allow an appendix argument. __ stop("Should not reach here"); // empty stubs make SG sick return nullptr; } // No need in interpreter entry for linkToNative for now. // Interpreter calls compiled entry through i2c. if (iid == vmIntrinsics::_linkToNative) { __ stop("Should not reach here"); // empty stubs make SG sick return nullptr; } Register R15_argbase = R15_esp; // parameter (preserved) Register R30_tmp1 = R30; Register R7_param_size = R7; // here's where control starts out: __ align(CodeEntryAlignment); address entry_point = __ pc(); if (VerifyMethodHandles) { assert(Method::intrinsic_id_size_in_bytes() == 2, "assuming Method::_intrinsic_id is u2"); Label L; BLOCK_COMMENT("verify_intrinsic_id {"); __ load_sized_value(R30_tmp1, in_bytes(Method::intrinsic_id_offset()), R19_method, sizeof(u2), /*is_signed*/ false); __ cmpwi(CR1, R30_tmp1, (int) iid); __ beq(CR1, L); if (iid == vmIntrinsics::_linkToVirtual || iid == vmIntrinsics::_linkToSpecial) { // could do this for all kinds, but would explode assembly code size trace_method_handle(_masm, "bad Method*:intrinsic_id"); } __ stop("bad Method*::intrinsic_id"); __ BIND(L); BLOCK_COMMENT("} verify_intrinsic_id"); } // First task: Find out how big the argument list is. int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid); assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic"); if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) { __ ld(R7_param_size, in_bytes(Method::const_offset()), R19_method); __ load_sized_value(R7_param_size, in_bytes(ConstMethod::size_of_parameters_offset()), R7_param_size, sizeof(u2), /*is_signed*/ false); // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), ""); } else { DEBUG_ONLY(R7_param_size = noreg); } Register tmp_mh = noreg; if (!is_signature_polymorphic_static(iid)) { __ ld(tmp_mh = R30_tmp1, __ argument_offset(R7_param_size, R7_param_size, 0), R15_argbase); DEBUG_ONLY(R7_param_size = noreg); } if (log_is_enabled(Info, methodhandles)) { if (tmp_mh != noreg) { __ mr(R23_method_handle, tmp_mh); // make stub happy } trace_method_handle_interpreter_entry(_masm, iid); } if (iid == vmIntrinsics::_invokeBasic) { generate_method_handle_dispatch(_masm, iid, tmp_mh, noreg, not_for_compiler_entry); } else { // Adjust argument list by popping the trailing MemberName argument. Register tmp_recv = noreg; if (MethodHandles::ref_kind_has_receiver(ref_kind)) { // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack. __ ld(tmp_recv = R30_tmp1, __ argument_offset(R7_param_size, R7_param_size, 0), R15_argbase); DEBUG_ONLY(R7_param_size = noreg); } Register R19_member = R19_method; // MemberName ptr; incoming method ptr is dead now __ ld(R19_member, RegisterOrConstant((intptr_t)8), R15_argbase); __ addi(R15_argbase, R15_argbase, Interpreter::stackElementSize); generate_method_handle_dispatch(_masm, iid, tmp_recv, R19_member, not_for_compiler_entry); } return entry_point; } void MethodHandles::jump_to_native_invoker(MacroAssembler* _masm, Register nep_reg, Register temp_target) { BLOCK_COMMENT("jump_to_native_invoker {"); assert_different_registers(nep_reg, temp_target); assert(nep_reg != noreg, "required register"); // Load the invoker, as NEP -> .invoker __ verify_oop(nep_reg); __ ld(temp_target, NONZERO(jdk_internal_foreign_abi_NativeEntryPoint::downcall_stub_address_offset_in_bytes()), nep_reg); __ mtctr(temp_target); __ bctr(); BLOCK_COMMENT("} jump_to_native_invoker"); } void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm, vmIntrinsics::ID iid, Register receiver_reg, Register member_reg, bool for_compiler_entry) { assert(is_signature_polymorphic(iid), "expected invoke iid"); Register temp1 = (for_compiler_entry ? R25_tmp5 : R31); // must be non-volatile due to runtime calls Register temp2 = (for_compiler_entry ? R22_tmp2 : R8); Register temp3 = (for_compiler_entry ? R23_tmp3 : R9); Register temp4 = (for_compiler_entry ? R24_tmp4 : R10); if (receiver_reg != noreg) assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg); if (member_reg != noreg) assert_different_registers(temp1, temp2, temp3, temp4, member_reg); const MacroAssembler::PreservationLevel preservation_level = for_compiler_entry ? MacroAssembler::PRESERVATION_FRAME_LR_GP_FP_REGS : MacroAssembler::PRESERVATION_FRAME_LR; if (iid == vmIntrinsics::_invokeBasic) { // indirect through MH.form.vmentry.vmtarget jump_to_lambda_form(_masm, receiver_reg, R19_method, temp1, temp2, for_compiler_entry); } else if (iid == vmIntrinsics::_linkToNative) { assert(for_compiler_entry, "only compiler entry is supported"); jump_to_native_invoker(_masm, member_reg, temp1); } else { // The method is a member invoker used by direct method handles. if (VerifyMethodHandles) { // make sure the trailing argument really is a MemberName (caller responsibility) verify_klass(_masm, member_reg, VM_CLASS_ID(MemberName_klass), temp1, temp2, "MemberName required for invokeVirtual etc."); } Register temp1_recv_klass = temp1; if (iid != vmIntrinsics::_linkToStatic) { BLOCK_COMMENT("check_receiver {"); __ verify_oop(receiver_reg, FILE_AND_LINE); const int klass_offset = iid == vmIntrinsics::_linkToSpecial ? -1 // enforce receiver null check : oopDesc::klass_offset_in_bytes(); // regular null-checking behavior address NullPointerException_entry = for_compiler_entry ? SharedRuntime::throw_NullPointerException_at_call_entry() : Interpreter::throw_NullPointerException_entry(); __ null_check_throw(receiver_reg, klass_offset, temp1, NullPointerException_entry); if (iid != vmIntrinsics::_linkToSpecial || VerifyMethodHandles) { __ load_klass(temp1_recv_klass, receiver_reg); __ verify_klass_ptr(temp1_recv_klass); } if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) { Label L_ok; Register temp2_defc = temp2; __ load_heap_oop(temp2_defc, NONZERO(java_lang_invoke_MemberName::clazz_offset()), member_reg, temp3, temp4, preservation_level, IS_NOT_NULL); load_klass_from_Class(_masm, temp2_defc, temp3, temp4); __ verify_klass_ptr(temp2_defc); __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok); // If we get here, the type check failed! __ stop("receiver class disagrees with MemberName.clazz"); __ BIND(L_ok); } BLOCK_COMMENT("} check_receiver"); } if (iid == vmIntrinsics::_linkToSpecial || iid == vmIntrinsics::_linkToStatic) { DEBUG_ONLY(temp1_recv_klass = noreg); // these guys didn't load the recv_klass } // Live registers at this point: // member_reg - MemberName that was the trailing argument // temp1_recv_klass - klass of stacked receiver, if needed Label L_incompatible_class_change_error; switch (iid) { case vmIntrinsics::_linkToSpecial: if (VerifyMethodHandles) { verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp2); } __ load_heap_oop(R19_method, NONZERO(java_lang_invoke_MemberName::method_offset()), member_reg, temp3, temp4, preservation_level, IS_NOT_NULL); __ ld(R19_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()), R19_method); break; case vmIntrinsics::_linkToStatic: if (VerifyMethodHandles) { verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp2); } __ load_heap_oop(R19_method, NONZERO(java_lang_invoke_MemberName::method_offset()), member_reg, temp3, temp4, preservation_level, IS_NOT_NULL); __ ld(R19_method, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset()), R19_method); break; case vmIntrinsics::_linkToVirtual: { // same as TemplateTable::invokevirtual, // minus the CP setup and profiling: if (VerifyMethodHandles) { verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp2); } // pick out the vtable index from the MemberName, and then we can discard it: Register temp2_index = temp2; __ ld(temp2_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset()), member_reg); if (VerifyMethodHandles) { Label L_index_ok; __ cmpdi(CR1, temp2_index, 0); __ bge(CR1, L_index_ok); __ stop("no virtual index"); __ BIND(L_index_ok); } // Note: The verifier invariants allow us to ignore MemberName.clazz and vmtarget // at this point. And VerifyMethodHandles has already checked clazz, if needed. // get target Method* & entry point __ lookup_virtual_method(temp1_recv_klass, temp2_index, R19_method); break; } case vmIntrinsics::_linkToInterface: { // same as TemplateTable::invokeinterface // (minus the CP setup and profiling, with different argument motion) if (VerifyMethodHandles) { verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp2); } Register temp2_intf = temp2; __ load_heap_oop(temp2_intf, NONZERO(java_lang_invoke_MemberName::clazz_offset()), member_reg, temp3, temp4, preservation_level, IS_NOT_NULL); load_klass_from_Class(_masm, temp2_intf, temp3, temp4); __ verify_klass_ptr(temp2_intf); Register vtable_index = R19_method; __ ld(vtable_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset()), member_reg); if (VerifyMethodHandles) { Label L_index_ok; __ cmpdi(CR1, vtable_index, 0); __ bge(CR1, L_index_ok); __ stop("invalid vtable index for MH.invokeInterface"); __ BIND(L_index_ok); } // given intf, index, and recv klass, dispatch to the implementation method __ lookup_interface_method(temp1_recv_klass, temp2_intf, // note: next two args must be the same: vtable_index, R19_method, temp3, temp4, L_incompatible_class_change_error); break; } default: fatal("unexpected intrinsic %d: %s", vmIntrinsics::as_int(iid), vmIntrinsics::name_at(iid)); break; } // Live at this point: // R19_method // After figuring out which concrete method to call, jump into it. // Note that this works in the interpreter with no data motion. // But the compiled version will require that rcx_recv be shifted out. __ verify_method_ptr(R19_method); jump_from_method_handle(_masm, R19_method, temp1, temp2, for_compiler_entry); if (iid == vmIntrinsics::_linkToInterface) { __ BIND(L_incompatible_class_change_error); __ load_const_optimized(temp1, SharedRuntime::throw_IncompatibleClassChangeError_entry()); __ mtctr(temp1); __ bctr(); } } } #ifndef PRODUCT void trace_method_handle_stub(const char* adaptername, oopDesc* mh, intptr_t* entry_sp, intptr_t* saved_regs) { bool has_mh = (strstr(adaptername, "/static") == nullptr && strstr(adaptername, "linkTo") == nullptr); // static linkers don't have MH const char* mh_reg_name = has_mh ? "R23_method_handle" : "G23"; log_info(methodhandles)("MH %s %s=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, adaptername, mh_reg_name, p2i(mh), p2i(entry_sp)); LogTarget(Trace, methodhandles) lt; if (lt.is_enabled()) { ResourceMark rm; LogStream ls(lt); ls.print_cr("Registers:"); const int abi_offset = frame::native_abi_reg_args_size / 8; for (int i = R3->encoding(); i <= R12->encoding(); i++) { Register r = as_Register(i); int count = i - R3->encoding(); // The registers are stored in reverse order on the stack (by save_volatile_gprs(R1_SP, native_abi_reg_args_size)). ls.print("%3s=" PTR_FORMAT, r->name(), saved_regs[abi_offset + count]); if ((count + 1) % 4 == 0) { ls.cr(); } else { ls.print(", "); } } ls.cr(); { // dumping last frame with frame::describe JavaThread* p = JavaThread::active(); // may not be needed by safer and unexpensive here PreserveExceptionMark pem(Thread::current()); FrameValues values; // Note: We want to allow trace_method_handle from any call site. // While trace_method_handle creates a frame, it may be entered // without a PC on the stack top (e.g. not just after a call). // Walking that frame could lead to failures due to that invalid PC. // => carefully detect that frame when doing the stack walking // Current C frame frame cur_frame = os::current_frame(); // Robust search of trace_calling_frame (independent of inlining). assert(cur_frame.sp() <= saved_regs, "registers not saved on stack ?"); frame trace_calling_frame = os::get_sender_for_C_frame(&cur_frame); while (trace_calling_frame.fp() < saved_regs) { trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame); } // Safely create a frame and call frame::describe. intptr_t *dump_sp = trace_calling_frame.sender_sp(); frame dump_frame = frame(dump_sp); dump_frame.describe(values, 1); values.describe(-1, saved_regs, "raw top of stack"); ls.print_cr("Stack layout:"); values.print_on(p, &ls); } if (has_mh && oopDesc::is_oop(mh)) { mh->print_on(&ls); if (java_lang_invoke_MethodHandle::is_instance(mh)) { java_lang_invoke_MethodHandle::form(mh)->print_on(&ls); } } } } void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) { if (!log_is_enabled(Info, methodhandles)) return; BLOCK_COMMENT("trace_method_handle {"); const Register tmp = R11; // Will be preserved. const int nbytes_save = MacroAssembler::num_volatile_regs * 8; __ save_volatile_gprs(R1_SP, -nbytes_save); // except R0 __ save_LR(tmp); // save in old frame __ mr(R5_ARG3, R1_SP); // saved_sp __ push_frame_reg_args(nbytes_save, tmp); __ load_const_optimized(R3_ARG1, (address)adaptername, tmp); __ mr(R4_ARG2, R23_method_handle); __ mr(R6_ARG4, R1_SP); __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub)); __ pop_frame(); __ restore_LR(tmp); __ restore_volatile_gprs(R1_SP, -nbytes_save); // except R0 BLOCK_COMMENT("} trace_method_handle"); } #endif // PRODUCT