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 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* vim: set ts=8 sts=2 et sw=2 tw=80: */

 // Copyright (c) 2006, 2012, Google Inc.

 // All rights reserved.

 //

 // Redistribution and use in source and binary forms, with or without

 // modification, are permitted provided that the following conditions are

 // met:

 //

 //     * Redistributions of source code must retain the above copyright

 // notice, this list of conditions and the following disclaimer.

 //     * Redistributions in binary form must reproduce the above

 // copyright notice, this list of conditions and the following disclaimer

 // in the documentation and/or other materials provided with the

 // distribution.

 //     * Neither the name of Google Inc. nor the names of its

 // contributors may be used to endorse or promote products derived from

 // this software without specific prior written permission.

 //

 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 // This file is derived from the following files in

 // toolkit/crashreporter/google-breakpad:

 //   src/common/android/include/elf.h

 //   src/common/linux/elfutils.h

 //   src/common/linux/file_id.h

 //   src/common/linux/elfutils-inl.h

 #ifndef LulElfInt_h

 #define LulElfInt_h

 // This header defines functions etc internal to the ELF reader.  It

 // should not be included outside of LulElf.cpp.

 #include <elf.h>

 #include <stdlib.h>

 #include "mozilla/Assertions.h"

 #include "LulPlatformMacros.h"

 // (derived from)

 // elfutils.h: Utilities for dealing with ELF files.

 //

 #if defined(LUL_OS_android)

 // From toolkit/crashreporter/google-breakpad/src/common/android/include/elf.h

 // The Android headers don't always define this constant.

 #ifndef EM_X86_64

 #define EM_X86_64  62

 #endif

 #ifndef EM_PPC64

 #define EM_PPC64   21

 #endif

 #ifndef EM_S390

 #define EM_S390    22

 #endif

 #ifndef NT_GNU_BUILD_ID

 #define NT_GNU_BUILD_ID 3

 #endif

 #define ElfW(type)      _ElfW (Elf, ELFSIZE, type)

 #define _ElfW(e,w,t)    _ElfW_1 (e, w, _##t)

 #define _ElfW_1(e,w,t)  e##w##t

 //FIXME

 extern "C" {

   extern char*  basename(const char*  path);

 };

 #else

 # include <link.h>

 #endif

 namespace lul {

 // Traits classes so consumers can write templatized code to deal

 // with specific ELF bits.

 struct ElfClass32 {

   typedef Elf32_Addr Addr;

   typedef Elf32_Ehdr Ehdr;

   typedef Elf32_Nhdr Nhdr;

   typedef Elf32_Phdr Phdr;

   typedef Elf32_Shdr Shdr;

   typedef Elf32_Half Half;

   typedef Elf32_Off Off;

   typedef Elf32_Word Word;

   static const int kClass = ELFCLASS32;

   static const size_t kAddrSize = sizeof(Elf32_Addr);

 };

 struct ElfClass64 {

   typedef Elf64_Addr Addr;

   typedef Elf64_Ehdr Ehdr;

   typedef Elf64_Nhdr Nhdr;

   typedef Elf64_Phdr Phdr;

   typedef Elf64_Shdr Shdr;

   typedef Elf64_Half Half;

   typedef Elf64_Off Off;

   typedef Elf64_Word Word;

   static const int kClass = ELFCLASS64;

   static const size_t kAddrSize = sizeof(Elf64_Addr);

 };

 bool IsValidElf(const void* elf_header);

 int ElfClass(const void* elf_base);

 // Attempt to find a section named |section_name| of type |section_type|

 // in the ELF binary data at |elf_mapped_base|. On success, returns true

 // and sets |*section_start| to point to the start of the section data,

 // and |*section_size| to the size of the section's data. If |elfclass|

 // is not NULL, set |*elfclass| to the ELF file class.

 bool FindElfSection(const void *elf_mapped_base,

                     const char *section_name,

                     uint32_t section_type,

                     const void **section_start,

                     int *section_size,

                     int *elfclass);

 // Internal helper method, exposed for convenience for callers

 // that already have more info.

 template<typename ElfClass>

 const typename ElfClass::Shdr*

 FindElfSectionByName(const char* name,

                      typename ElfClass::Word section_type,

                      const typename ElfClass::Shdr* sections,

                      const char* section_names,

                      const char* names_end,

                      int nsection);

 // Attempt to find the first segment of type |segment_type| in the ELF

 // binary data at |elf_mapped_base|. On success, returns true and sets

 // |*segment_start| to point to the start of the segment data, and

 // and |*segment_size| to the size of the segment's data. If |elfclass|

 // is not NULL, set |*elfclass| to the ELF file class.

 bool FindElfSegment(const void *elf_mapped_base,

                     uint32_t segment_type,

                     const void **segment_start,

                     int *segment_size,

                     int *elfclass);

 // Convert an offset from an Elf header into a pointer to the mapped

 // address in the current process. Takes an extra template parameter

 // to specify the return type to avoid having to dynamic_cast the

 // result.

 template<typename ElfClass, typename T>

 const T*

 GetOffset(const typename ElfClass::Ehdr* elf_header,

           typename ElfClass::Off offset);

 // (derived from)

 // file_id.h: Return a unique identifier for a file

 //

 static const size_t kMDGUIDSize = sizeof(MDGUID);

 class FileID {

  public:

   // Load the identifier for the elf file mapped into memory at |base| into

   // |identifier|.  Return false if the identifier could not be created for the

   // file.

   static bool ElfFileIdentifierFromMappedFile(const void* base,

                                               uint8_t identifier[kMDGUIDSize]);

   // Convert the |identifier| data to a NULL terminated string.  The string will

   // be formatted as a UUID (e.g., 22F065BB-FC9C-49F7-80FE-26A7CEBD7BCE).

   // The |buffer| should be at least 37 bytes long to receive all of the data

   // and termination.  Shorter buffers will contain truncated data.

   static void ConvertIdentifierToString(const uint8_t identifier[kMDGUIDSize],

                                         char* buffer, int buffer_length);

 };

 template<typename ElfClass, typename T>

 const T* GetOffset(const typename ElfClass::Ehdr* elf_header,

                    typename ElfClass::Off offset) {

   return reinterpret_cast<const T*>(reinterpret_cast<uintptr_t>(elf_header) +

                                     offset);

 }

 template<typename ElfClass>

 const typename ElfClass::Shdr* FindElfSectionByName(

     const char* name,

     typename ElfClass::Word section_type,

     const typename ElfClass::Shdr* sections,

     const char* section_names,

     const char* names_end,

     int nsection) {

   MOZ_ASSERT(name != NULL);

   MOZ_ASSERT(sections != NULL);

   MOZ_ASSERT(nsection > 0);

   int name_len = strlen(name);

   if (name_len == 0)

     return NULL;

   for (int i = 0; i < nsection; ++i) {

     const char* section_name = section_names + sections[i].sh_name;

     if (sections[i].sh_type == section_type &&

         names_end - section_name >= name_len + 1 &&

         strcmp(name, section_name) == 0) {

       return sections + i;

     }

   }

   return NULL;

 }

 } // namespace lul

 // And finally, the external interface, offered to LulMain.cpp

 #include "LulElfExt.h"

 #endif // LulElfInt_h