1 /* 2 * Copyright (c) 2008, 2016, 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/assembler.hpp" 28 #include "assembler_arm.inline.hpp" 29 #include "classfile/systemDictionary.hpp" 30 #include "code/vmreg.hpp" 31 #include "interpreter/interpreter.hpp" 32 #include "memory/resourceArea.hpp" 33 #include "nativeInst_arm.hpp" 34 #include "opto/runtime.hpp" 35 #include "runtime/interfaceSupport.inline.hpp" 36 #include "runtime/sharedRuntime.hpp" 37 #include "runtime/stubRoutines.hpp" 38 #include "runtime/vframeArray.hpp" 39 #include "utilities/globalDefinitions.hpp" 40 #include "vmreg_arm.inline.hpp" 41 #endif 42 43 #define __ masm-> 44 45 //------------------------------ generate_exception_blob --------------------------- 46 // creates exception blob at the end 47 // Using exception blob, this code is jumped from a compiled method. 48 // (see emit_exception_handler in sparc.ad file) 49 // 50 // Given an exception pc at a call we call into the runtime for the 51 // handler in this method. This handler might merely restore state 52 // (i.e. callee save registers) unwind the frame and jump to the 53 // exception handler for the nmethod if there is no Java level handler 54 // for the nmethod. 55 // 56 // This code is entered with a jmp. 57 // 58 // Arguments: 59 // Rexception_obj (R4/R19): exception oop 60 // Rexception_pc (R5/R20): exception pc 61 // 62 // Results: 63 // Rexception_obj (R4/R19): exception oop 64 // O1: exception pc in caller or ??? 65 // destination: exception handler of caller 66 // 67 // Note: the exception pc MUST be at a call (precise debug information) 68 // 69 void OptoRuntime::generate_exception_blob() { 70 // allocate space for code 71 ResourceMark rm; 72 int pad = VerifyThread ? 256 : 0;// Extra slop space for more verify code 73 74 // setup code generation tools 75 // Measured 8/7/03 at 256 in 32bit debug build (no VerifyThread) 76 // Measured 8/7/03 at 528 in 32bit debug build (VerifyThread) 77 CodeBuffer buffer("exception_blob", 600+pad, 512); 78 MacroAssembler* masm = new MacroAssembler(&buffer); 79 80 int framesize_in_words = 2; // FP + LR 81 int framesize_in_bytes = framesize_in_words * wordSize; 82 int framesize_in_slots = framesize_in_bytes / sizeof(jint); 83 84 int start = __ offset(); 85 86 __ str(Rexception_obj, Address(Rthread, JavaThread::exception_oop_offset())); 87 __ str(Rexception_pc, Address(Rthread, JavaThread::exception_pc_offset())); 88 89 // This call does all the hard work. It checks if an exception catch 90 // exists in the method. 91 // If so, it returns the handler address. 92 // If the nmethod has been deoptimized and it had a handler the handler 93 // address is the deopt blob unpack_with_exception entry. 94 // 95 // If no handler exists it prepares for stack-unwinding, restoring the callee-save 96 // registers of the frame being removed. 97 // 98 __ mov(LR, Rexception_pc); 99 __ raw_push(FP, LR); 100 int pc_offset = __ set_last_Java_frame(SP, FP, false, Rtemp); 101 102 __ mov(R0, Rthread); 103 104 // This call can block at exit and nmethod can be deoptimized at that 105 // point. If the nmethod had a catch point we would jump to the 106 // now deoptimized catch point and fall thru the vanilla deopt 107 // path and lose the exception 108 // Sure would be simpler if this call didn't block! 109 __ call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C)); 110 if (pc_offset == -1) { 111 pc_offset = __ offset(); 112 } 113 114 // Set an oopmap for the call site. This oopmap will only be used if we 115 // are unwinding the stack. Hence, all locations will be dead. 116 // Callee-saved registers will be the same as the frame above (i.e., 117 // handle_exception_stub), since they were restored when we got the 118 // exception. 119 120 OopMapSet *oop_maps = new OopMapSet(); 121 oop_maps->add_gc_map(pc_offset - start, new OopMap(framesize_in_slots, 0)); 122 123 __ reset_last_Java_frame(Rtemp); 124 125 __ raw_pop(FP, LR); 126 127 // Restore SP from its saved reg (FP) if the exception PC is a MethodHandle call site. 128 __ ldr(Rtemp, Address(Rthread, JavaThread::is_method_handle_return_offset())); 129 #ifdef AARCH64 130 Label skip; 131 __ cbz(Rtemp, skip); 132 __ mov(SP, Rmh_SP_save); 133 __ bind(skip); 134 #else 135 __ cmp(Rtemp, 0); 136 __ mov(SP, Rmh_SP_save, ne); 137 #endif 138 139 // R0 contains handler address 140 // Since this may be the deopt blob we must set R5 to look like we returned 141 // from the original pc that threw the exception 142 143 __ ldr(Rexception_pc, Address(Rthread, JavaThread::exception_pc_offset())); // R5/R20 144 145 __ ldr(Rexception_obj, Address(Rthread, JavaThread::exception_oop_offset())); // R4/R19 146 __ mov(Rtemp, 0); 147 #ifdef ASSERT 148 __ str(Rtemp, Address(Rthread, JavaThread::exception_handler_pc_offset())); 149 __ str(Rtemp, Address(Rthread, JavaThread::exception_pc_offset())); 150 #endif 151 // Clear the exception oop so GC no longer processes it as a root. 152 __ str(Rtemp, Address(Rthread, JavaThread::exception_oop_offset())); 153 __ jump(R0); 154 155 // ------------- 156 // make sure all code is generated 157 masm->flush(); 158 159 _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words); 160 }