1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef COURGETTE_ENCODED_PROGRAM_H_ 6 #define COURGETTE_ENCODED_PROGRAM_H_ 7 8 #include <vector> 9 10 #include "base/basictypes.h" 11 #include "courgette/disassembler.h" 12 #include "courgette/memory_allocator.h" 13 #include "courgette/types_elf.h" 14 15 namespace courgette { 16 17 class SinkStream; 18 class SinkStreamSet; 19 class SourceStreamSet; 20 21 // An EncodedProgram is a set of tables that contain a simple 'binary assembly 22 // language' that can be assembled to produce a sequence of bytes, for example, 23 // a Windows 32-bit executable. 24 // 25 class EncodedProgram { 26 public: 27 EncodedProgram(); 28 ~EncodedProgram(); 29 30 // Generating an EncodedProgram: 31 // 32 // (1) The image base can be specified at any time. set_image_base(uint64 base)33 void set_image_base(uint64 base) { image_base_ = base; } 34 35 // (2) Address tables and indexes defined first. 36 CheckBool DefineRel32Label(int index, RVA address) WARN_UNUSED_RESULT; 37 CheckBool DefineAbs32Label(int index, RVA address) WARN_UNUSED_RESULT; 38 void EndLabels(); 39 40 // (3) Add instructions in the order needed to generate bytes of file. 41 // NOTE: If any of these methods ever fail, the EncodedProgram instance 42 // has failed and should be discarded. 43 CheckBool AddOrigin(RVA rva) WARN_UNUSED_RESULT; 44 CheckBool AddCopy(uint32 count, const void* bytes) WARN_UNUSED_RESULT; 45 CheckBool AddRel32(int label_index) WARN_UNUSED_RESULT; 46 CheckBool AddRel32ARM(uint16 op, int label_index) WARN_UNUSED_RESULT; 47 CheckBool AddAbs32(int label_index) WARN_UNUSED_RESULT; 48 CheckBool AddPeMakeRelocs(ExecutableType kind) WARN_UNUSED_RESULT; 49 CheckBool AddElfMakeRelocs() WARN_UNUSED_RESULT; 50 CheckBool AddElfARMMakeRelocs() WARN_UNUSED_RESULT; 51 52 // (3) Serialize binary assembly language tables to a set of streams. 53 CheckBool WriteTo(SinkStreamSet* streams) WARN_UNUSED_RESULT; 54 55 // Using an EncodedProgram to generate a byte stream: 56 // 57 // (4) Deserializes a fresh EncodedProgram from a set of streams. 58 bool ReadFrom(SourceStreamSet* streams); 59 60 // (5) Assembles the 'binary assembly language' into final file. 61 CheckBool AssembleTo(SinkStream* buffer) WARN_UNUSED_RESULT; 62 63 private: 64 // Binary assembly language operations. 65 // These are part of the patch format. Reusing an existing value will 66 // break backwards compatibility. 67 enum OP { 68 ORIGIN = 0, // ORIGIN <rva> - set address for subsequent assembly. 69 COPY = 1, // COPY <count> <bytes> - copy bytes to output. 70 COPY1 = 2, // COPY1 <byte> - same as COPY 1 <byte>. 71 REL32 = 3, // REL32 <index> - emit rel32 encoded reference to address at 72 // address table offset <index> 73 ABS32 = 4, // ABS32 <index> - emit abs32 encoded reference to address at 74 // address table offset <index> 75 MAKE_PE_RELOCATION_TABLE = 5, // Emit PE base relocation table blocks. 76 MAKE_ELF_RELOCATION_TABLE = 6, // Emit Elf relocation table for X86 77 MAKE_ELF_ARM_RELOCATION_TABLE = 7, // Emit Elf relocation table for ARM 78 MAKE_PE64_RELOCATION_TABLE = 8, // Emit PE64 base relocation table blocks. 79 // ARM reserves 0x1000-LAST_ARM, bits 13-16 define the opcode 80 // subset, and 1-12 are the compressed ARM op. 81 REL32ARM8 = 0x1000, 82 REL32ARM11 = 0x2000, 83 REL32ARM24 = 0x3000, 84 REL32ARM25 = 0x4000, 85 REL32ARM21 = 0x5000, 86 LAST_ARM = 0x5FFF, 87 }; 88 89 typedef NoThrowBuffer<RVA> RvaVector; 90 typedef NoThrowBuffer<uint32> UInt32Vector; 91 typedef NoThrowBuffer<uint8> UInt8Vector; 92 typedef NoThrowBuffer<OP> OPVector; 93 94 void DebuggingSummary(); 95 CheckBool GeneratePeRelocations(SinkStream *buffer, 96 uint8 type) WARN_UNUSED_RESULT; 97 CheckBool GenerateElfRelocations(Elf32_Word pending_elf_relocation_table, 98 SinkStream *buffer) WARN_UNUSED_RESULT; 99 CheckBool DefineLabelCommon(RvaVector*, int, RVA) WARN_UNUSED_RESULT; 100 void FinishLabelsCommon(RvaVector* addresses); 101 102 // Decodes and evaluates courgette ops for ARM rel32 addresses. 103 CheckBool EvaluateRel32ARM(OP op, size_t& ix_rel32_ix, RVA& current_rva, 104 SinkStream* output); 105 106 // Binary assembly language tables. 107 uint64 image_base_; 108 RvaVector rel32_rva_; 109 RvaVector abs32_rva_; 110 OPVector ops_; 111 RvaVector origins_; 112 UInt32Vector copy_counts_; 113 UInt8Vector copy_bytes_; 114 UInt32Vector rel32_ix_; 115 UInt32Vector abs32_ix_; 116 117 // Table of the addresses containing abs32 relocations; computed during 118 // assembly, used to generate base relocation table. 119 UInt32Vector abs32_relocs_; 120 121 DISALLOW_COPY_AND_ASSIGN(EncodedProgram); 122 }; 123 124 } // namespace courgette 125 #endif // COURGETTE_ENCODED_PROGRAM_H_ 126