mirror of
https://github.com/serge1/ELFIO.git
synced 2025-03-16 19:21:07 +00:00
597 lines
22 KiB
C++
597 lines
22 KiB
C++
/*
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Copyright (C) 2001-present by Serge Lamikhov-Center
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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#ifndef ELFIO_RELOCATION_HPP
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#define ELFIO_RELOCATION_HPP
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namespace ELFIO {
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template <typename T> struct get_sym_and_type;
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template <> struct get_sym_and_type<Elf32_Rel>
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{
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//------------------------------------------------------------------------------
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//! \brief Get the symbol from the relocation info
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//! \param info Relocation info
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//! \return Symbol
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static int get_r_sym( Elf_Xword info )
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{
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return ELF32_R_SYM( (Elf_Word)info );
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}
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//------------------------------------------------------------------------------
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//! \brief Get the type from the relocation info
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//! \param info Relocation info
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//! \return Type
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static int get_r_type( Elf_Xword info )
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{
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return ELF32_R_TYPE( (Elf_Word)info );
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}
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};
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template <> struct get_sym_and_type<Elf32_Rela>
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{
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//------------------------------------------------------------------------------
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//! \brief Get the symbol from the relocation info
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//! \param info Relocation info
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//! \return Symbol
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static int get_r_sym( Elf_Xword info )
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{
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return ELF32_R_SYM( (Elf_Word)info );
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}
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//------------------------------------------------------------------------------
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//! \brief Get the type from the relocation info
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//! \param info Relocation info
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//! \return Type
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static int get_r_type( Elf_Xword info )
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{
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return ELF32_R_TYPE( (Elf_Word)info );
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}
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};
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template <> struct get_sym_and_type<Elf64_Rel>
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{
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//------------------------------------------------------------------------------
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//! \brief Get the symbol from the relocation info
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//! \param info Relocation info
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//! \return Symbol
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static int get_r_sym( Elf_Xword info ) { return ELF64_R_SYM( info ); }
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//------------------------------------------------------------------------------
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//! \brief Get the type from the relocation info
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//! \param info Relocation info
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//! \return Type
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static int get_r_type( Elf_Xword info ) { return ELF64_R_TYPE( info ); }
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};
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template <> struct get_sym_and_type<Elf64_Rela>
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{
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//------------------------------------------------------------------------------
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//! \brief Get the symbol from the relocation info
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//! \param info Relocation info
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//! \return Symbol
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static int get_r_sym( Elf_Xword info ) { return ELF64_R_SYM( info ); }
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//------------------------------------------------------------------------------
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//! \brief Get the type from the relocation info
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//! \param info Relocation info
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//! \return Type
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static int get_r_type( Elf_Xword info ) { return ELF64_R_TYPE( info ); }
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};
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//------------------------------------------------------------------------------
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//! \class relocation_section_accessor_template
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//! \brief Class for accessing relocation section data
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template <class S> class relocation_section_accessor_template
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{
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public:
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//------------------------------------------------------------------------------
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//! \brief Constructor
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//! \param elf_file Reference to the ELF file
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//! \param section Pointer to the section
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explicit relocation_section_accessor_template( const elfio& elf_file,
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S* section )
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: elf_file( elf_file ), relocation_section( section )
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{
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}
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//------------------------------------------------------------------------------
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//! \brief Get the number of entries
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//! \return Number of entries
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Elf_Xword get_entries_num() const
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{
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Elf_Xword nRet = 0;
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if ( 0 != relocation_section->get_entry_size() ) {
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nRet = relocation_section->get_size() /
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relocation_section->get_entry_size();
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}
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return nRet;
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}
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//------------------------------------------------------------------------------
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//! \brief Get an entry
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//! \param index Index of the entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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//! \return True if successful, false otherwise
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bool get_entry( Elf_Xword index,
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Elf64_Addr& offset,
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Elf_Word& symbol,
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unsigned& type,
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Elf_Sxword& addend ) const
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{
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if ( index >= get_entries_num() ) { // Is index valid
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return false;
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}
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if ( elf_file.get_class() == ELFCLASS32 ) {
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if ( SHT_REL == relocation_section->get_type() ) {
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return generic_get_entry_rel<Elf32_Rel>( index, offset, symbol,
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type, addend );
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}
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else if ( SHT_RELA == relocation_section->get_type() ) {
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return generic_get_entry_rela<Elf32_Rela>(
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index, offset, symbol, type, addend );
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}
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}
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else {
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if ( SHT_REL == relocation_section->get_type() ) {
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return generic_get_entry_rel<Elf64_Rel>( index, offset, symbol,
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type, addend );
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}
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else if ( SHT_RELA == relocation_section->get_type() ) {
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return generic_get_entry_rela<Elf64_Rela>(
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index, offset, symbol, type, addend );
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}
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}
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// Unknown relocation section type.
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return false;
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}
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//------------------------------------------------------------------------------
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//! \brief Get an entry with additional information
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//! \param index Index of the entry
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//! \param offset Offset of the entry
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//! \param symbolValue Value of the symbol
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//! \param symbolName Name of the symbol
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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//! \param calcValue Calculated value
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//! \return True if successful, false otherwise
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bool get_entry( Elf_Xword index,
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Elf64_Addr& offset,
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Elf64_Addr& symbolValue,
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std::string& symbolName,
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unsigned& type,
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Elf_Sxword& addend,
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Elf_Sxword& calcValue ) const
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{
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// Do regular job
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Elf_Word symbol = 0;
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bool ret = get_entry( index, offset, symbol, type, addend );
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// Find the symbol
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Elf_Xword size;
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unsigned char bind;
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unsigned char symbolType;
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Elf_Half section;
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unsigned char other;
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symbol_section_accessor symbols(
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elf_file, elf_file.sections[get_symbol_table_index()] );
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ret = ret && symbols.get_symbol( symbol, symbolName, symbolValue, size,
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bind, symbolType, section, other );
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if ( ret ) { // Was it successful?
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switch ( type ) {
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case R_386_NONE: // none
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calcValue = 0;
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break;
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case R_386_32: // S + A
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calcValue = symbolValue + addend;
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break;
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case R_386_PC32: // S + A - P
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calcValue = symbolValue + addend - offset;
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break;
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case R_386_GOT32: // G + A - P
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calcValue = 0;
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break;
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case R_386_PLT32: // L + A - P
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calcValue = 0;
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break;
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case R_386_COPY: // none
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calcValue = 0;
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break;
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case R_386_GLOB_DAT: // S
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case R_386_JMP_SLOT: // S
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calcValue = symbolValue;
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break;
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case R_386_RELATIVE: // B + A
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calcValue = addend;
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break;
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case R_386_GOTOFF: // S + A - GOT
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calcValue = 0;
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break;
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case R_386_GOTPC: // GOT + A - P
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calcValue = 0;
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break;
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default: // Not recognized symbol!
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calcValue = 0;
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break;
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}
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}
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return ret;
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}
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//------------------------------------------------------------------------------
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//! \brief Set an entry
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//! \param index Index of the entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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//! \return True if successful, false otherwise
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bool set_entry( Elf_Xword index,
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Elf64_Addr offset,
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Elf_Word symbol,
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unsigned type,
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Elf_Sxword addend )
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{
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if ( index >= get_entries_num() ) { // Is index valid
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return false;
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}
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if ( elf_file.get_class() == ELFCLASS32 ) {
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if ( SHT_REL == relocation_section->get_type() ) {
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generic_set_entry_rel<Elf32_Rel>( index, offset, symbol, type,
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addend );
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}
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else if ( SHT_RELA == relocation_section->get_type() ) {
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generic_set_entry_rela<Elf32_Rela>( index, offset, symbol, type,
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addend );
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}
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}
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else {
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if ( SHT_REL == relocation_section->get_type() ) {
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generic_set_entry_rel<Elf64_Rel>( index, offset, symbol, type,
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addend );
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}
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else if ( SHT_RELA == relocation_section->get_type() ) {
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generic_set_entry_rela<Elf64_Rela>( index, offset, symbol, type,
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addend );
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}
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}
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return true;
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}
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//------------------------------------------------------------------------------
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//! \brief Add an entry
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//! \param offset Offset of the entry
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//! \param info Information of the entry
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void add_entry( Elf64_Addr offset, Elf_Xword info )
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{
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if ( elf_file.get_class() == ELFCLASS32 ) {
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generic_add_entry<Elf32_Rel>( offset, info );
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}
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else {
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generic_add_entry<Elf64_Rel>( offset, info );
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}
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}
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//------------------------------------------------------------------------------
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//! \brief Add an entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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void add_entry( Elf64_Addr offset, Elf_Word symbol, unsigned type )
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{
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Elf_Xword info;
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if ( elf_file.get_class() == ELFCLASS32 ) {
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info = ELF32_R_INFO( (Elf_Xword)symbol, type );
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}
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else {
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info = ELF64_R_INFO( (Elf_Xword)symbol, type );
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}
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add_entry( offset, info );
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}
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//------------------------------------------------------------------------------
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//! \brief Add an entry
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//! \param offset Offset of the entry
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//! \param info Information of the entry
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//! \param addend Addend of the entry
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void add_entry( Elf64_Addr offset, Elf_Xword info, Elf_Sxword addend )
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{
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if ( elf_file.get_class() == ELFCLASS32 ) {
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generic_add_entry<Elf32_Rela>( offset, info, addend );
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}
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else {
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generic_add_entry<Elf64_Rela>( offset, info, addend );
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}
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}
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//------------------------------------------------------------------------------
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//! \brief Add an entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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void add_entry( Elf64_Addr offset,
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Elf_Word symbol,
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unsigned type,
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Elf_Sxword addend )
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{
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Elf_Xword info;
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if ( elf_file.get_class() == ELFCLASS32 ) {
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info = ELF32_R_INFO( (Elf_Xword)symbol, type );
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}
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else {
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info = ELF64_R_INFO( (Elf_Xword)symbol, type );
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}
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add_entry( offset, info, addend );
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}
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//------------------------------------------------------------------------------
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//! \brief Add an entry with additional information
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//! \param str_writer String section accessor
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//! \param str String
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//! \param sym_writer Symbol section accessor
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//! \param value Value of the symbol
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//! \param size Size of the symbol
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//! \param sym_info Symbol information
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//! \param other Other information
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//! \param shndx Section index
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//! \param offset Offset of the entry
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//! \param type Type of the entry
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void add_entry( string_section_accessor str_writer,
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const char* str,
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symbol_section_accessor sym_writer,
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Elf64_Addr value,
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Elf_Word size,
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unsigned char sym_info,
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unsigned char other,
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Elf_Half shndx,
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Elf64_Addr offset,
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unsigned type )
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{
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Elf_Word str_index = str_writer.add_string( str );
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Elf_Word sym_index = sym_writer.add_symbol( str_index, value, size,
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sym_info, other, shndx );
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add_entry( offset, sym_index, type );
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}
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//------------------------------------------------------------------------------
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//! \brief Swap symbols
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//! \param first First symbol
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//! \param second Second symbol
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void swap_symbols( Elf_Xword first, Elf_Xword second )
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{
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Elf64_Addr offset = 0;
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Elf_Word symbol = 0;
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unsigned rtype = 0;
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Elf_Sxword addend = 0;
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for ( Elf_Word i = 0; i < get_entries_num(); i++ ) {
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get_entry( i, offset, symbol, rtype, addend );
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if ( symbol == first ) {
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set_entry( i, offset, (Elf_Word)second, rtype, addend );
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}
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if ( symbol == second ) {
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set_entry( i, offset, (Elf_Word)first, rtype, addend );
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}
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}
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}
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//------------------------------------------------------------------------------
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private:
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//------------------------------------------------------------------------------
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//! \brief Get the symbol table index
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//! \return Symbol table index
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Elf_Half get_symbol_table_index() const
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{
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return (Elf_Half)relocation_section->get_link();
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}
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//------------------------------------------------------------------------------
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//! \brief Get a generic entry for REL type
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//! \param index Index of the entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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//! \return True if successful, false otherwise
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template <class T>
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bool generic_get_entry_rel( Elf_Xword index,
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Elf64_Addr& offset,
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Elf_Word& symbol,
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unsigned& type,
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Elf_Sxword& addend ) const
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{
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const endianness_convertor& convertor = elf_file.get_convertor();
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if ( relocation_section->get_entry_size() < sizeof( T ) ) {
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return false;
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}
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const T* pEntry = reinterpret_cast<const T*>(
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relocation_section->get_data() +
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index * relocation_section->get_entry_size() );
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offset = convertor( pEntry->r_offset );
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Elf_Xword tmp = convertor( pEntry->r_info );
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symbol = get_sym_and_type<T>::get_r_sym( tmp );
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type = get_sym_and_type<T>::get_r_type( tmp );
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addend = 0;
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return true;
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}
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//------------------------------------------------------------------------------
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//! \brief Get a generic entry for RELA type
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//! \param index Index of the entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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//! \return True if successful, false otherwise
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template <class T>
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bool generic_get_entry_rela( Elf_Xword index,
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Elf64_Addr& offset,
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Elf_Word& symbol,
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unsigned& type,
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Elf_Sxword& addend ) const
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{
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const endianness_convertor& convertor = elf_file.get_convertor();
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if ( relocation_section->get_entry_size() < sizeof( T ) ) {
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return false;
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}
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const T* pEntry = reinterpret_cast<const T*>(
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relocation_section->get_data() +
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index * relocation_section->get_entry_size() );
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offset = convertor( pEntry->r_offset );
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Elf_Xword tmp = convertor( pEntry->r_info );
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symbol = get_sym_and_type<T>::get_r_sym( tmp );
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type = get_sym_and_type<T>::get_r_type( tmp );
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addend = convertor( pEntry->r_addend );
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return true;
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}
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//------------------------------------------------------------------------------
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//! \brief Set a generic entry for REL type
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//! \param index Index of the entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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template <class T>
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void generic_set_entry_rel( Elf_Xword index,
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Elf64_Addr offset,
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Elf_Word symbol,
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unsigned type,
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Elf_Sxword )
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{
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const endianness_convertor& convertor = elf_file.get_convertor();
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T* pEntry = const_cast<T*>( reinterpret_cast<const T*>(
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relocation_section->get_data() +
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index * relocation_section->get_entry_size() ) );
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if ( elf_file.get_class() == ELFCLASS32 ) {
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pEntry->r_info = ELF32_R_INFO( (Elf_Xword)symbol, type );
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}
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else {
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pEntry->r_info = ELF64_R_INFO( (Elf_Xword)symbol, type );
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}
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pEntry->r_offset = decltype( pEntry->r_offset )( offset );
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pEntry->r_offset = convertor( pEntry->r_offset );
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pEntry->r_info = convertor( pEntry->r_info );
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}
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//------------------------------------------------------------------------------
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//! \brief Set a generic entry for RELA type
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//! \param index Index of the entry
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//! \param offset Offset of the entry
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//! \param symbol Symbol of the entry
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//! \param type Type of the entry
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//! \param addend Addend of the entry
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template <class T>
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void generic_set_entry_rela( Elf_Xword index,
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Elf64_Addr offset,
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Elf_Word symbol,
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unsigned type,
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|
Elf_Sxword addend )
|
|
{
|
|
const endianness_convertor& convertor = elf_file.get_convertor();
|
|
|
|
T* pEntry = const_cast<T*>( reinterpret_cast<const T*>(
|
|
relocation_section->get_data() +
|
|
index * relocation_section->get_entry_size() ) );
|
|
|
|
if ( elf_file.get_class() == ELFCLASS32 ) {
|
|
pEntry->r_info = ELF32_R_INFO( (Elf_Xword)symbol, type );
|
|
}
|
|
else {
|
|
pEntry->r_info = ELF64_R_INFO( (Elf_Xword)symbol, type );
|
|
}
|
|
pEntry->r_offset = decltype( pEntry->r_offset )( offset );
|
|
pEntry->r_addend = decltype( pEntry->r_addend )( addend );
|
|
pEntry->r_offset = convertor( pEntry->r_offset );
|
|
pEntry->r_info = convertor( pEntry->r_info );
|
|
pEntry->r_addend = convertor( pEntry->r_addend );
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
//! \brief Add a generic entry for REL type
|
|
//! \param offset Offset of the entry
|
|
//! \param info Information of the entry
|
|
template <class T>
|
|
void generic_add_entry( Elf64_Addr offset, Elf_Xword info )
|
|
{
|
|
const endianness_convertor& convertor = elf_file.get_convertor();
|
|
|
|
T entry;
|
|
entry.r_offset = decltype( entry.r_offset )( offset );
|
|
entry.r_info = decltype( entry.r_info )( info );
|
|
entry.r_offset = convertor( entry.r_offset );
|
|
entry.r_info = convertor( entry.r_info );
|
|
|
|
relocation_section->append_data( reinterpret_cast<char*>( &entry ),
|
|
sizeof( entry ) );
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
//! \brief Add a generic entry for RELA type
|
|
//! \param offset Offset of the entry
|
|
//! \param info Information of the entry
|
|
//! \param addend Addend of the entry
|
|
template <class T>
|
|
void
|
|
generic_add_entry( Elf64_Addr offset, Elf_Xword info, Elf_Sxword addend )
|
|
{
|
|
const endianness_convertor& convertor = elf_file.get_convertor();
|
|
|
|
T entry;
|
|
entry.r_offset = offset;
|
|
entry.r_info = info;
|
|
entry.r_addend = addend;
|
|
entry.r_offset = convertor( entry.r_offset );
|
|
entry.r_info = convertor( entry.r_info );
|
|
entry.r_addend = convertor( entry.r_addend );
|
|
|
|
relocation_section->append_data( reinterpret_cast<char*>( &entry ),
|
|
sizeof( entry ) );
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
private:
|
|
const elfio& elf_file;
|
|
S* relocation_section = nullptr;
|
|
};
|
|
|
|
using relocation_section_accessor =
|
|
relocation_section_accessor_template<section>;
|
|
using const_relocation_section_accessor =
|
|
relocation_section_accessor_template<const section>;
|
|
|
|
} // namespace ELFIO
|
|
|
|
#endif // ELFIO_RELOCATION_HPP
|