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1 // Copyright 2017 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 COMPONENTS_ZUCCHINI_DISASSEMBLER_WIN32_H_
6 #define COMPONENTS_ZUCCHINI_DISASSEMBLER_WIN32_H_
7 
8 #include <stddef.h>
9 #include <stdint.h>
10 
11 #include <deque>
12 #include <memory>
13 #include <string>
14 #include <utility>
15 #include <vector>
16 
17 #include "components/zucchini/address_translator.h"
18 #include "components/zucchini/buffer_view.h"
19 #include "components/zucchini/disassembler.h"
20 #include "components/zucchini/image_utils.h"
21 #include "components/zucchini/type_win_pe.h"
22 
23 namespace zucchini {
24 
25 class Rel32FinderX86;
26 class Rel32FinderX64;
27 
28 struct Win32X86Traits {
29   static constexpr uint16_t kVersion = 1;
30   static constexpr Bitness kBitness = kBit32;
31   static constexpr ExecutableType kExeType = kExeTypeWin32X86;
32   enum : uint16_t { kMagic = 0x10B };
33   enum : uint16_t { kRelocType = 3 };
34   enum : uint32_t { kVAWidth = 4 };
35   static const char kExeTypeString[];
36 
37   using ImageOptionalHeader = pe::ImageOptionalHeader;
38   using RelFinder = Rel32FinderX86;
39   using Address = uint32_t;
40 };
41 
42 struct Win32X64Traits {
43   static constexpr uint16_t kVersion = 1;
44   static constexpr Bitness kBitness = kBit64;
45   static constexpr ExecutableType kExeType = kExeTypeWin32X64;
46   enum : uint16_t { kMagic = 0x20B };
47   enum : uint16_t { kRelocType = 10 };
48   enum : uint32_t { kVAWidth = 8 };
49   static const char kExeTypeString[];
50 
51   using ImageOptionalHeader = pe::ImageOptionalHeader64;
52   using RelFinder = Rel32FinderX64;
53   using Address = uint64_t;
54 };
55 
56 template <class TRAITS>
57 class DisassemblerWin32 : public Disassembler {
58  public:
59   using Traits = TRAITS;
60   static constexpr uint16_t kVersion = Traits::kVersion;
61   enum ReferenceType : uint8_t { kReloc, kAbs32, kRel32, kTypeCount };
62 
63   // Applies quick checks to determine whether |image| *may* point to the start
64   // of an executable. Returns true iff the check passes.
65   static bool QuickDetect(ConstBufferView image);
66 
67   DisassemblerWin32();
68   DisassemblerWin32(const DisassemblerWin32&) = delete;
69   const DisassemblerWin32& operator=(const DisassemblerWin32&) = delete;
70   ~DisassemblerWin32() override;
71 
72   // Disassembler:
73   ExecutableType GetExeType() const override;
74   std::string GetExeTypeString() const override;
75   std::vector<ReferenceGroup> MakeReferenceGroups() const override;
76 
77   // Functions that return reader / writer for references.
78   std::unique_ptr<ReferenceReader> MakeReadRelocs(offset_t lo, offset_t hi);
79   std::unique_ptr<ReferenceReader> MakeReadAbs32(offset_t lo, offset_t hi);
80   std::unique_ptr<ReferenceReader> MakeReadRel32(offset_t lo, offset_t hi);
81   std::unique_ptr<ReferenceWriter> MakeWriteRelocs(MutableBufferView image);
82   std::unique_ptr<ReferenceWriter> MakeWriteAbs32(MutableBufferView image);
83   std::unique_ptr<ReferenceWriter> MakeWriteRel32(MutableBufferView image);
84 
85  private:
86   friend Disassembler;
87 
88   // Disassembler:
89   bool Parse(ConstBufferView image) override;
90 
91   // Parses the file header. Returns true iff successful.
92   bool ParseHeader();
93 
94   // Parsers to extract references. These are lazily called, and return whether
95   // parsing was successful (failures are non-fatal).
96   bool ParseAndStoreRelocBlocks();
97   bool ParseAndStoreAbs32();
98   bool ParseAndStoreRel32();
99 
100   // In-memory copy of sections.
101   std::vector<pe::ImageSectionHeader> sections_;
102 
103   // Image base address to translate between RVA and VA.
104   typename Traits::Address image_base_ = 0;
105 
106   // Pointer to data Directory entry of the relocation table.
107   const pe::ImageDataDirectory* base_relocation_table_ = nullptr;
108 
109   // Translator between offsets and RVAs.
110   AddressTranslator translator_;
111 
112   // Reference storage.
113   BufferRegion reloc_region_ = {kInvalidOffset, 0U};
114   std::vector<offset_t> reloc_block_offsets_;
115   offset_t reloc_end_ = 0;
116   std::vector<offset_t> abs32_locations_;
117   // Using std::deque to reduce peak memory footprint.
118   std::deque<offset_t> rel32_locations_;
119 
120   // Initialization states of reference storage, used for lazy initialization.
121   // TODO(huangs): Investigate whether lazy initialization is useful for memory
122   // reduction. This is a carryover from Courgette. To be sure we should run
123   // experiment after Zucchini is able to do ensemble patching.
124   bool has_parsed_relocs_ = false;
125   bool has_parsed_abs32_ = false;
126   bool has_parsed_rel32_ = false;
127 };
128 
129 using DisassemblerWin32X86 = DisassemblerWin32<Win32X86Traits>;
130 using DisassemblerWin32X64 = DisassemblerWin32<Win32X64Traits>;
131 
132 }  // namespace zucchini
133 
134 #endif  // COMPONENTS_ZUCCHINI_DISASSEMBLER_WIN32_H_
135