1 /* 2 * Copyright (c) 2016, 2018, 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 26 package jdk.tools.jaotc.binformat.elf; 27 28 import jdk.tools.jaotc.binformat.BinaryContainer; 29 import jdk.tools.jaotc.binformat.Relocation; 30 import jdk.tools.jaotc.binformat.Relocation.RelocType; 31 import jdk.tools.jaotc.binformat.Symbol; 32 import jdk.tools.jaotc.binformat.elf.Elf.Elf64_Ehdr; 33 import jdk.tools.jaotc.binformat.elf.Elf.Elf64_Rela; 34 35 public class AMD64JELFRelocObject extends JELFRelocObject { 36 AMD64JELFRelocObject(BinaryContainer binContainer, String outputFileName)37 AMD64JELFRelocObject(BinaryContainer binContainer, String outputFileName) { 38 super(binContainer, outputFileName); 39 } 40 41 @Override createRelocation(Symbol symbol, Relocation reloc, ElfRelocTable elfRelocTable)42 protected void createRelocation(Symbol symbol, Relocation reloc, ElfRelocTable elfRelocTable) { 43 RelocType relocType = reloc.getType(); 44 45 int elfRelocType = getELFRelocationType(relocType); 46 ElfSymbol sym = (ElfSymbol) symbol.getNativeSymbol(); 47 int symno = sym.getIndex(); 48 int sectindex = reloc.getSection().getSectionId(); 49 int offset = reloc.getOffset(); 50 int addend = 0; 51 52 switch (relocType) { 53 case JAVA_CALL_DIRECT: 54 case STUB_CALL_DIRECT: 55 case FOREIGN_CALL_INDIRECT_GOT: { 56 // Create relocation entry 57 addend = -4; // Size in bytes of the patch location 58 // Relocation should be applied at the location after call operand 59 offset = offset + reloc.getSize() + addend; 60 break; 61 } 62 case JAVA_CALL_INDIRECT: 63 case METASPACE_GOT_REFERENCE: 64 case EXTERNAL_PLT_TO_GOT: { 65 addend = -4; // Size of 32-bit address of the GOT 66 /* 67 * Relocation should be applied before the test instruction to the move instruction. 68 * reloc.getOffset() points to the test instruction after the instruction that loads 69 * the address of polling page. So set the offset appropriately. 70 */ 71 offset = offset + addend; 72 break; 73 } 74 case EXTERNAL_GOT_TO_PLT: { 75 // this is load time relocations 76 break; 77 } 78 default: 79 throw new InternalError("Unhandled relocation type: " + relocType); 80 } 81 elfRelocTable.createRelocationEntry(sectindex, offset, symno, elfRelocType, addend); 82 } 83 getELFRelocationType(RelocType relocType)84 private static int getELFRelocationType(RelocType relocType) { 85 int elfRelocType = 0; // R_<ARCH>_NONE if #define'd to 0 for all values of ARCH 86 switch (ElfTargetInfo.getElfArch()) { 87 case Elf64_Ehdr.EM_X86_64: 88 // Return R_X86_64_* entries based on relocType 89 if (relocType == RelocType.JAVA_CALL_DIRECT || 90 relocType == RelocType.FOREIGN_CALL_INDIRECT_GOT) { 91 elfRelocType = Elf64_Rela.R_X86_64_PLT32; 92 } else if (relocType == RelocType.STUB_CALL_DIRECT) { 93 elfRelocType = Elf64_Rela.R_X86_64_PC32; 94 } else if (relocType == RelocType.JAVA_CALL_INDIRECT) { 95 elfRelocType = Elf64_Rela.R_X86_64_NONE; 96 } else if (relocType == RelocType.METASPACE_GOT_REFERENCE || 97 relocType == RelocType.EXTERNAL_PLT_TO_GOT) { 98 elfRelocType = Elf64_Rela.R_X86_64_PC32; 99 } else if (relocType == RelocType.EXTERNAL_GOT_TO_PLT) { 100 elfRelocType = Elf64_Rela.R_X86_64_64; 101 } else { 102 assert false : "Unhandled relocation type: " + relocType; 103 } 104 break; 105 106 default: 107 System.out.println("Relocation Type mapping: Unhandled architecture: " + ElfTargetInfo.getElfArch()); 108 } 109 return elfRelocType; 110 } 111 } 112