| #------------------------------------------------------------------------------- |
| # elftools: dwarf/dwarfrelocationmanager.py |
| # |
| # DWARFRelocationManager - handles relocations of DWARF data |
| # |
| # Eli Bendersky (eliben@gmail.com) |
| # This code is in the public domain |
| #------------------------------------------------------------------------------- |
| from ..elf.sections import RelocationSection |
| |
| |
| class DWARFRelocationManager(object): |
| """ Manages relocations for some DWARF section |
| """ |
| def __init__(self, elffile, section_name): |
| """ |
| """ |
| self.elffile = elffile |
| self.section_name = section_name |
| self._section = self.elffile.get_section_by_name(section_name) |
| |
| # _relocs maps an offset in the section to an index in the relocation |
| # table. |
| # _reloc_section is the relocation section object |
| # ... both are loaded by _load_relocations |
| self._relocs = {} |
| self._reloc_section = None |
| self._load_relocations() |
| |
| def has_relocation(self, offset): |
| """ Does the given offset have a relocation registered for it? |
| The offset is relative to its section. |
| """ |
| return offset in self._relocs |
| |
| def apply_relocation(self, offset, value): |
| """ Apply the relocation registered for the given offset. value is |
| the original value at that offset. Return the relocated value. |
| """ |
| reloc_index = self._relocs[offset] |
| return self.elffile.apply_relocation( |
| reloc_section=self._reloc_section, |
| reloc_index=reloc_index, |
| offset=offset, |
| value=value) |
| |
| def _load_relocations(self): |
| # Currently assume that only a single relocation section will exist |
| # for our section, and that it's either a .rel or a .rela |
| reloc_section_names = ( |
| '.rel' + self.section_name, |
| '.rela' + self.section_name) |
| for section in self.elffile.iter_sections(): |
| if ( isinstance(section, RelocationSection) and |
| section.name in reloc_section_names): |
| self._reloc_section = section |
| for i, reloc in enumerate( |
| self._reloc_section.iter_relocations()): |
| self._relocs[reloc['r_offset']] = i |
| break |
| |
