1 /* 2 * Copyright (c) 1998, 2011, 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 #ifdef COMPILER2 27 #include "asm/macroAssembler.hpp" 28 #include "asm/macroAssembler.inline.hpp" 29 #include "classfile/systemDictionary.hpp" 30 #include "code/vmreg.hpp" 31 #include "interpreter/interpreter.hpp" 32 #include "opto/runtime.hpp" 33 #include "runtime/interfaceSupport.hpp" 34 #include "runtime/sharedRuntime.hpp" 35 #include "runtime/stubRoutines.hpp" 36 #include "runtime/vframeArray.hpp" 37 #include "utilities/globalDefinitions.hpp" 38 #include "vmreg_x86.inline.hpp" 39 #endif 40 41 42 #define __ masm-> 43 44 //------------------------------generate_exception_blob--------------------------- 45 // creates exception blob at the end 46 // Using exception blob, this code is jumped from a compiled method. 47 // 48 // Given an exception pc at a call we call into the runtime for the 49 // handler in this method. This handler might merely restore state 50 // (i.e. callee save registers) unwind the frame and jump to the 51 // exception handler for the nmethod if there is no Java level handler 52 // for the nmethod. 53 // 54 // This code is entered with a jmp. 55 // 56 // Arguments: 57 // rax: exception oop 58 // rdx: exception pc 59 // 60 // Results: 61 // rax: exception oop 62 // rdx: exception pc in caller or ??? 63 // destination: exception handler of caller 64 // 65 // Note: the exception pc MUST be at a call (precise debug information) 66 // Only register rax, rdx, rcx are not callee saved. 67 // 68 69 void OptoRuntime::generate_exception_blob() { 70 71 // Capture info about frame layout 72 enum layout { 73 thread_off, // last_java_sp 74 // The frame sender code expects that rbp will be in the "natural" place and 75 // will override any oopMap setting for it. We must therefore force the layout 76 // so that it agrees with the frame sender code. 77 rbp_off, 78 return_off, // slot for return address 79 framesize 80 }; 81 82 // allocate space for the code 83 ResourceMark rm; 84 // setup code generation tools 85 CodeBuffer buffer("exception_blob", 512, 512); 86 MacroAssembler* masm = new MacroAssembler(&buffer); 87 88 OopMapSet *oop_maps = new OopMapSet(); 89 90 address start = __ pc(); 91 92 __ push(rdx); 93 __ subptr(rsp, return_off * wordSize); // Prolog! 94 95 // rbp, location is implicitly known 96 __ movptr(Address(rsp,rbp_off *wordSize), rbp); 97 98 // Store exception in Thread object. We cannot pass any arguments to the 99 // handle_exception call, since we do not want to make any assumption 100 // about the size of the frame where the exception happened in. 101 __ get_thread(rcx); 102 __ movptr(Address(rcx, JavaThread::exception_oop_offset()), rax); 103 __ movptr(Address(rcx, JavaThread::exception_pc_offset()), rdx); 104 105 // This call does all the hard work. It checks if an exception handler 106 // exists in the method. 107 // If so, it returns the handler address. 108 // If not, it prepares for stack-unwinding, restoring the callee-save 109 // registers of the frame being removed. 110 // 111 __ movptr(Address(rsp, thread_off * wordSize), rcx); // Thread is first argument 112 __ set_last_Java_frame(rcx, noreg, noreg, NULL); 113 114 __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C))); 115 116 // No registers to map, rbp is known implicitly 117 oop_maps->add_gc_map( __ pc() - start, new OopMap( framesize, 0 )); 118 __ get_thread(rcx); 119 __ reset_last_Java_frame(rcx, false, false); 120 121 // Restore callee-saved registers 122 __ movptr(rbp, Address(rsp, rbp_off * wordSize)); 123 124 __ addptr(rsp, return_off * wordSize); // Epilog! 125 __ pop(rdx); // Exception pc 126 127 // rax: exception handler for given <exception oop/exception pc> 128 129 // We have a handler in rax, (could be deopt blob) 130 // rdx - throwing pc, deopt blob will need it. 131 132 __ push(rax); 133 134 // Get the exception 135 __ movptr(rax, Address(rcx, JavaThread::exception_oop_offset())); 136 // Get the exception pc in case we are deoptimized 137 __ movptr(rdx, Address(rcx, JavaThread::exception_pc_offset())); 138 #ifdef ASSERT 139 __ movptr(Address(rcx, JavaThread::exception_handler_pc_offset()), NULL_WORD); 140 __ movptr(Address(rcx, JavaThread::exception_pc_offset()), NULL_WORD); 141 #endif 142 // Clear the exception oop so GC no longer processes it as a root. 143 __ movptr(Address(rcx, JavaThread::exception_oop_offset()), NULL_WORD); 144 145 __ pop(rcx); 146 147 // rax: exception oop 148 // rcx: exception handler 149 // rdx: exception pc 150 __ jmp (rcx); 151 152 // ------------- 153 // make sure all code is generated 154 masm->flush(); 155 156 _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize); 157 }