File indexing completed on 2024-05-12 05:43:30

 /*
     Copyright (C) 2015 Volker Krause <vkrause@kde.org>
 
     This program is free software; you can redistribute it and/or modify it
     under the terms of the GNU Library General Public License as published by
     the Free Software Foundation; either version 2 of the License, or (at your
     option) any later version.
 
     This program is distributed in the hope that it will be useful, but WITHOUT
     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
     License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
 #include "elfrelocationentry.h"
 #include "elfrelocationsection.h"
 #include "elffile.h"
 #include "elfsymboltablesection.h"
 
 #include <elf.h>
 
 ElfRelocationEntry::ElfRelocationEntry() :
     m_section(nullptr),
     m_index(0),
     m_withAddend(0)
 {
 }
 
 ElfRelocationEntry::ElfRelocationEntry(const ElfRelocationEntry&) = default;
 
 ElfRelocationEntry::ElfRelocationEntry(const ElfRelocationSection* section, uint64_t index, bool withAddend) :
     m_section(section),
     m_index(index),
     m_withAddend(withAddend)
 {
 }
 
 ElfRelocationEntry::~ElfRelocationEntry() = default;
 
 ElfRelocationEntry& ElfRelocationEntry::operator=(const ElfRelocationEntry&) = default;
 
 const ElfRelocationSection* ElfRelocationEntry::relocationTable() const
 {
     return m_section;
 }
 
 uint64_t ElfRelocationEntry::offset() const
 {
     if (is64()) {
         if (m_withAddend)
             return entry<Elf64_Rela>()->r_offset;
         else
             return entry<Elf64_Rel>()->r_offset;
     } else {
         if (m_withAddend)
             return entry<Elf32_Rela>()->r_offset;
         else
             return entry<Elf32_Rel>()->r_offset;
     }
     Q_UNREACHABLE();
 }
 
 uint32_t ElfRelocationEntry::symbolIndex() const
 {
     if (is64()) {
         if (m_withAddend)
             return ELF64_R_SYM(entry<Elf64_Rela>()->r_info);
         else
             return ELF64_R_SYM(entry<Elf64_Rel>()->r_info);
     } else {
         if (m_withAddend)
             return ELF32_R_SYM(entry<Elf32_Rela>()->r_info);
         else
             return ELF32_R_SYM(entry<Elf32_Rel>()->r_info);
     }
     Q_UNREACHABLE();
 }
 
 uint32_t ElfRelocationEntry::type() const
 {
     if (is64()) {
         if (m_withAddend)
             return ELF64_R_TYPE(entry<Elf64_Rela>()->r_info);
         else
             return ELF64_R_TYPE(entry<Elf64_Rel>()->r_info);
     } else {
         if (m_withAddend)
             return ELF32_R_TYPE(entry<Elf32_Rela>()->r_info);
         else
             return ELF32_R_TYPE(entry<Elf32_Rel>()->r_info);
     }
     Q_UNREACHABLE();
 }
 
 uint64_t ElfRelocationEntry::addend() const
 {
     if (m_withAddend) {
         if (is64()) {
             return entry<Elf64_Rela>()->r_addend;
         } else {
             return entry<Elf32_Rela>()->r_addend;
         }
     } else {
         // TODO
         Q_ASSERT_X(false, "", "not yet implemented!");
         return 0;
     }
     Q_UNREACHABLE();
 }
 
 template <typename T>
 const T* ElfRelocationEntry::entry() const
 {
     return reinterpret_cast<const T*>(m_section->rawData() + m_index * m_section->header()->entrySize());
 }
 
 bool ElfRelocationEntry::is64() const
 {
     return m_section->file()->type() == ELFCLASS64;
 }
 
 ElfSymbolTableEntry* ElfRelocationEntry::symbol() const
 {
     const auto symIdx = symbolIndex();
     if (symIdx > 0)
         return m_section->linkedSection<ElfSymbolTableSection>()->entry(symIdx);
     return nullptr;
 }
 
 uint64_t ElfRelocationEntry::relocationTarget() const
 {
     // ### TODO ### this is utterly incomplete and largely incorrect!!
     // this would need to implement the platform-specific relocation logic for all types
     // the below approximation just barely covers the current uses of this function
 
     if (symbolIndex() && addend()) {
         Q_ASSERT_X(false, "", "not yet implemented!");
         return 0;
     }
 
     if (symbolIndex()) {
         return symbol()->value();
     }
     return addend();
 }