courgette/disassembler_win32_x86.h

   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_DISASSEMBLER_WIN32_X86_H_
   6 #define COURGETTE_DISASSEMBLER_WIN32_X86_H_
   7
   8 #include "base/basictypes.h"
   9 #include "courgette/disassembler.h"
  10 #include "courgette/memory_allocator.h"
  11 #include "courgette/types_win_pe.h"
  12
  13 #ifdef COURGETTE_HISTOGRAM_TARGETS
  14 #include <map>
  15 #endif
  16
  17 namespace courgette {
  18
  19 class AssemblyProgram;
  20
  21 class DisassemblerWin32X86 : public Disassembler {
  22  public:
  23   explicit DisassemblerWin32X86(const void* start, size_t length);
  24
  25   virtual ExecutableType kind() { return EXE_WIN_32_X86; }
  26
  27   // Returns 'true' if the buffer appears to point to a Windows 32 bit
  28   // executable, 'false' otherwise.  If ParseHeader() succeeds, other member
  29   // functions may be called.
  30   virtual bool ParseHeader();
  31
  32   virtual bool Disassemble(AssemblyProgram* target);
  33
  34   //
  35   // Exposed for test purposes
  36   //
  37
  38   bool has_text_section() const { return has_text_section_; }
  39   uint32 size_of_code() const { return size_of_code_; }
  40   bool is_32bit() const { return !is_PE32_plus_; }
  41
  42   // Returns 'true' if the base relocation table can be parsed.
  43   // Output is a vector of the RVAs corresponding to locations within executable
  44   // that are listed in the base relocation table.
  45   bool ParseRelocs(std::vector<RVA> *addresses);
  46
  47   // Returns Section containing the relative virtual address, or NULL if none.
  48   const Section* RVAToSection(RVA rva) const;
  49
  50   static const int kNoOffset = -1;
  51   // Returns kNoOffset if there is no file offset corresponding to 'rva'.
  52   int RVAToFileOffset(RVA rva) const;
  53
  54   // Returns same as FileOffsetToPointer(RVAToFileOffset(rva)) except that NULL
  55   // is returned if there is no file offset corresponding to 'rva'.
  56   const uint8* RVAToPointer(RVA rva) const;
  57
  58   static std::string SectionName(const Section* section);
  59
  60  protected:
  61   CheckBool ParseFile(AssemblyProgram* target) WARN_UNUSED_RESULT;
  62   bool ParseAbs32Relocs();
  63   void ParseRel32RelocsFromSections();
  64   void ParseRel32RelocsFromSection(const Section* section);
  65
  66   CheckBool ParseNonSectionFileRegion(uint32 start_file_offset,
  67       uint32 end_file_offset, AssemblyProgram* program) WARN_UNUSED_RESULT;
  68   CheckBool ParseFileRegion(const Section* section,
  69       uint32 start_file_offset, uint32 end_file_offset,
  70       AssemblyProgram* program) WARN_UNUSED_RESULT;
  71
  72 #if COURGETTE_HISTOGRAM_TARGETS
  73   void HistogramTargets(const char* kind, const std::map<RVA, int>& map);
  74 #endif
  75
  76   // Most addresses are represented as 32-bit RVAs.  The one address we can't
  77   // do this with is the image base address.  'image_base' is valid only for
  78   // 32-bit executables. 'image_base_64' is valid for 32- and 64-bit executable.
  79   uint32 image_base() const { return static_cast<uint32>(image_base_); }
  80
  81   const ImageDataDirectory& base_relocation_table() const {
  82     return base_relocation_table_;
  83   }
  84
  85   bool IsValidRVA(RVA rva) const { return rva < size_of_image_; }
  86
  87   // Returns description of the RVA, e.g. ".text+0x1243".  For debugging only.
  88   std::string DescribeRVA(RVA rva) const;
  89
  90   // Finds the first section at file_offset or above.  Does not return sections
  91   // that have no raw bytes in the file.
  92   const Section* FindNextSection(uint32 file_offset) const;
  93
  94   // There are 2 'coordinate systems' for reasoning about executables.
  95   //   FileOffset - the the offset within a single .EXE or .DLL *file*.
  96   //   RVA - relative virtual address (offset within *loaded image*)
  97   // FileOffsetToRVA and RVAToFileOffset convert between these representations.
  98
  99   RVA FileOffsetToRVA(uint32 offset) const;
 100
 101
 102  private:
 103
 104   bool ReadDataDirectory(int index, ImageDataDirectory* dir);
 105
 106   bool incomplete_disassembly_;  // 'true' if can leave out 'uninteresting' bits
 107
 108   std::vector<RVA> abs32_locations_;
 109   std::vector<RVA> rel32_locations_;
 110
 111   //
 112   // Fields that are always valid.
 113   //
 114
 115   //
 116   // Information that is valid after successful ParseHeader.
 117   //
 118   bool is_PE32_plus_;   // PE32_plus is for 64 bit executables.
 119
 120   // Location and size of IMAGE_OPTIONAL_HEADER in the buffer.
 121   const uint8 *optional_header_;
 122   uint16 size_of_optional_header_;
 123   uint16 offset_of_data_directories_;
 124
 125   uint16 machine_type_;
 126   uint16 number_of_sections_;
 127   const Section *sections_;
 128   bool has_text_section_;
 129
 130   uint32 size_of_code_;
 131   uint32 size_of_initialized_data_;
 132   uint32 size_of_uninitialized_data_;
 133   RVA base_of_code_;
 134   RVA base_of_data_;
 135
 136   uint64 image_base_;  // range limited to 32 bits for 32 bit executable
 137   uint32 size_of_image_;
 138   int number_of_data_directories_;
 139
 140   ImageDataDirectory export_table_;
 141   ImageDataDirectory import_table_;
 142   ImageDataDirectory resource_table_;
 143   ImageDataDirectory exception_table_;
 144   ImageDataDirectory base_relocation_table_;
 145   ImageDataDirectory bound_import_table_;
 146   ImageDataDirectory import_address_table_;
 147   ImageDataDirectory delay_import_descriptor_;
 148   ImageDataDirectory clr_runtime_header_;
 149
 150 #if COURGETTE_HISTOGRAM_TARGETS
 151   std::map<RVA, int> abs32_target_rvas_;
 152   std::map<RVA, int> rel32_target_rvas_;
 153 #endif
 154
 155
 156   DISALLOW_COPY_AND_ASSIGN(DisassemblerWin32X86);
 157 };
 158
 159 }  // namespace courgette
 160 #endif  // COURGETTE_DISASSEMBLER_WIN32_X86_H_