557 lines
22 KiB
Python
557 lines
22 KiB
Python
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#-------------------------------------------------------------------------------
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# elftools: elf/structs.py
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#
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# Encapsulation of Construct structs for parsing an ELF file, adjusted for
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# correct endianness and word-size.
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#
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# Eli Bendersky (eliben@gmail.com)
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# This code is in the public domain
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#-------------------------------------------------------------------------------
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from ..construct import (
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UBInt8, UBInt16, UBInt32, UBInt64,
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ULInt8, ULInt16, ULInt32, ULInt64,
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SBInt32, SLInt32, SBInt64, SLInt64,
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Struct, Array, Enum, Padding, BitStruct, BitField, Value, String, CString,
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Switch, Field
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)
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from ..common.construct_utils import ULEB128
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from ..common.utils import roundup
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from .enums import *
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class ELFStructs(object):
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""" Accessible attributes:
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Elf_{byte|half|word|word64|addr|offset|sword|xword|xsword}:
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Data chunks, as specified by the ELF standard, adjusted for
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correct endianness and word-size.
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Elf_Ehdr:
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ELF file header
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Elf_Phdr:
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Program header
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Elf_Shdr:
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Section header
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Elf_Sym:
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Symbol table entry
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Elf_Rel, Elf_Rela:
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Entries in relocation sections
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"""
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def __init__(self, little_endian=True, elfclass=32):
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assert elfclass == 32 or elfclass == 64
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self.little_endian = little_endian
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self.elfclass = elfclass
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self.e_type = None
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self.e_machine = None
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self.e_ident_osabi = None
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def __getstate__(self):
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return self.little_endian, self.elfclass, self.e_type, self.e_machine, self.e_ident_osabi
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def __setstate__(self, state):
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self.little_endian, self.elfclass, e_type, e_machine, e_osabi = state
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self.create_basic_structs()
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self.create_advanced_structs(e_type, e_machine, e_osabi)
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def create_basic_structs(self):
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""" Create word-size related structs and ehdr struct needed for
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initial determining of ELF type.
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"""
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if self.little_endian:
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self.Elf_byte = ULInt8
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self.Elf_half = ULInt16
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self.Elf_word = ULInt32
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self.Elf_word64 = ULInt64
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self.Elf_addr = ULInt32 if self.elfclass == 32 else ULInt64
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self.Elf_offset = self.Elf_addr
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self.Elf_sword = SLInt32
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self.Elf_xword = ULInt32 if self.elfclass == 32 else ULInt64
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self.Elf_sxword = SLInt32 if self.elfclass == 32 else SLInt64
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else:
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self.Elf_byte = UBInt8
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self.Elf_half = UBInt16
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self.Elf_word = UBInt32
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self.Elf_word64 = UBInt64
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self.Elf_addr = UBInt32 if self.elfclass == 32 else UBInt64
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self.Elf_offset = self.Elf_addr
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self.Elf_sword = SBInt32
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self.Elf_xword = UBInt32 if self.elfclass == 32 else UBInt64
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self.Elf_sxword = SBInt32 if self.elfclass == 32 else SBInt64
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self._create_ehdr()
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self._create_leb128()
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self._create_ntbs()
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def create_advanced_structs(self, e_type=None, e_machine=None, e_ident_osabi=None):
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""" Create all ELF structs except the ehdr. They may possibly depend
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on provided e_type and/or e_machine parsed from ehdr.
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"""
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self.e_type = e_type
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self.e_machine = e_machine
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self.e_ident_osabi = e_ident_osabi
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self._create_phdr()
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self._create_shdr()
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self._create_chdr()
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self._create_sym()
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self._create_rel()
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self._create_dyn()
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self._create_sunw_syminfo()
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self._create_gnu_verneed()
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self._create_gnu_verdef()
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self._create_gnu_versym()
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self._create_gnu_abi()
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self._create_gnu_property()
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self._create_note(e_type)
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self._create_stabs()
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self._create_attributes_subsection()
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self._create_arm_attributes()
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self._create_riscv_attributes()
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self._create_elf_hash()
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self._create_gnu_hash()
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#-------------------------------- PRIVATE --------------------------------#
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def _create_ehdr(self):
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self.Elf_Ehdr = Struct('Elf_Ehdr',
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Struct('e_ident',
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Array(4, self.Elf_byte('EI_MAG')),
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Enum(self.Elf_byte('EI_CLASS'), **ENUM_EI_CLASS),
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Enum(self.Elf_byte('EI_DATA'), **ENUM_EI_DATA),
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Enum(self.Elf_byte('EI_VERSION'), **ENUM_E_VERSION),
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Enum(self.Elf_byte('EI_OSABI'), **ENUM_EI_OSABI),
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self.Elf_byte('EI_ABIVERSION'),
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Padding(7)
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),
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Enum(self.Elf_half('e_type'), **ENUM_E_TYPE),
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Enum(self.Elf_half('e_machine'), **ENUM_E_MACHINE),
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Enum(self.Elf_word('e_version'), **ENUM_E_VERSION),
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self.Elf_addr('e_entry'),
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self.Elf_offset('e_phoff'),
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self.Elf_offset('e_shoff'),
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self.Elf_word('e_flags'),
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self.Elf_half('e_ehsize'),
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self.Elf_half('e_phentsize'),
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self.Elf_half('e_phnum'),
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self.Elf_half('e_shentsize'),
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self.Elf_half('e_shnum'),
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self.Elf_half('e_shstrndx'),
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)
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def _create_leb128(self):
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self.Elf_uleb128 = ULEB128
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def _create_ntbs(self):
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self.Elf_ntbs = CString
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def _create_phdr(self):
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p_type_dict = ENUM_P_TYPE_BASE
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if self.e_machine == 'EM_ARM':
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p_type_dict = ENUM_P_TYPE_ARM
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elif self.e_machine == 'EM_AARCH64':
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p_type_dict = ENUM_P_TYPE_AARCH64
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elif self.e_machine == 'EM_MIPS':
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p_type_dict = ENUM_P_TYPE_MIPS
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elif self.e_machine == 'EM_RISCV':
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p_type_dict = ENUM_P_TYPE_RISCV
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if self.elfclass == 32:
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self.Elf_Phdr = Struct('Elf_Phdr',
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Enum(self.Elf_word('p_type'), **p_type_dict),
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self.Elf_offset('p_offset'),
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self.Elf_addr('p_vaddr'),
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self.Elf_addr('p_paddr'),
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self.Elf_word('p_filesz'),
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self.Elf_word('p_memsz'),
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self.Elf_word('p_flags'),
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self.Elf_word('p_align'),
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)
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else: # 64
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self.Elf_Phdr = Struct('Elf_Phdr',
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Enum(self.Elf_word('p_type'), **p_type_dict),
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self.Elf_word('p_flags'),
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self.Elf_offset('p_offset'),
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self.Elf_addr('p_vaddr'),
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self.Elf_addr('p_paddr'),
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self.Elf_xword('p_filesz'),
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self.Elf_xword('p_memsz'),
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self.Elf_xword('p_align'),
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)
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def _create_shdr(self):
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"""Section header parsing.
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Depends on e_machine because of machine-specific values in sh_type.
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"""
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sh_type_dict = ENUM_SH_TYPE_BASE
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if self.e_machine == 'EM_ARM':
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sh_type_dict = ENUM_SH_TYPE_ARM
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elif self.e_machine == 'EM_X86_64':
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sh_type_dict = ENUM_SH_TYPE_AMD64
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elif self.e_machine == 'EM_MIPS':
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sh_type_dict = ENUM_SH_TYPE_MIPS
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if self.e_machine == 'EM_RISCV':
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sh_type_dict = ENUM_SH_TYPE_RISCV
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self.Elf_Shdr = Struct('Elf_Shdr',
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self.Elf_word('sh_name'),
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Enum(self.Elf_word('sh_type'), **sh_type_dict),
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self.Elf_xword('sh_flags'),
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self.Elf_addr('sh_addr'),
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self.Elf_offset('sh_offset'),
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self.Elf_xword('sh_size'),
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self.Elf_word('sh_link'),
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self.Elf_word('sh_info'),
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self.Elf_xword('sh_addralign'),
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self.Elf_xword('sh_entsize'),
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)
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def _create_chdr(self):
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# Structure of compressed sections header. It is documented in Oracle
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# "Linker and Libraries Guide", Part IV ELF Application Binary
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# Interface, Chapter 13 Object File Format, Section Compression:
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# https://docs.oracle.com/cd/E53394_01/html/E54813/section_compression.html
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fields = [
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Enum(self.Elf_word('ch_type'), **ENUM_ELFCOMPRESS_TYPE),
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self.Elf_xword('ch_size'),
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self.Elf_xword('ch_addralign'),
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]
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if self.elfclass == 64:
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fields.insert(1, self.Elf_word('ch_reserved'))
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self.Elf_Chdr = Struct('Elf_Chdr', *fields)
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def _create_rel(self):
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# r_info is also taken apart into r_info_sym and r_info_type. This is
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# done in Value to avoid endianity issues while parsing.
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if self.elfclass == 32:
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fields = [self.Elf_xword('r_info'),
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Value('r_info_sym',
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lambda ctx: (ctx['r_info'] >> 8) & 0xFFFFFF),
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Value('r_info_type',
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lambda ctx: ctx['r_info'] & 0xFF)]
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elif self.e_machine == 'EM_MIPS': # ELF64 MIPS
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fields = [
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# The MIPS ELF64 specification
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# (https://www.linux-mips.org/pub/linux/mips/doc/ABI/elf64-2.4.pdf)
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# provides a non-standard relocation structure definition.
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self.Elf_word('r_sym'),
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self.Elf_byte('r_ssym'),
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self.Elf_byte('r_type3'),
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self.Elf_byte('r_type2'),
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self.Elf_byte('r_type'),
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# Synthetize usual fields for compatibility with other
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# architectures. This allows relocation consumers (including
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# our readelf tests) to work without worrying about MIPS64
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# oddities.
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Value('r_info_sym', lambda ctx: ctx['r_sym']),
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Value('r_info_ssym', lambda ctx: ctx['r_ssym']),
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Value('r_info_type', lambda ctx: ctx['r_type']),
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Value('r_info_type2', lambda ctx: ctx['r_type2']),
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Value('r_info_type3', lambda ctx: ctx['r_type3']),
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Value('r_info',
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lambda ctx: (ctx['r_sym'] << 32)
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| (ctx['r_ssym'] << 24)
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| (ctx['r_type3'] << 16)
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| (ctx['r_type2'] << 8)
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| ctx['r_type']),
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]
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else: # Other 64 ELFs
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fields = [self.Elf_xword('r_info'),
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Value('r_info_sym',
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lambda ctx: (ctx['r_info'] >> 32) & 0xFFFFFFFF),
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Value('r_info_type',
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lambda ctx: ctx['r_info'] & 0xFFFFFFFF)]
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self.Elf_Rel = Struct('Elf_Rel',
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self.Elf_addr('r_offset'),
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*fields)
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fields_and_addend = fields + [self.Elf_sxword('r_addend')]
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self.Elf_Rela = Struct('Elf_Rela',
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self.Elf_addr('r_offset'),
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*fields_and_addend
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)
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# Elf32_Relr is typedef'd as Elf32_Word, Elf64_Relr as Elf64_Xword
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# (see the glibc patch, for example:
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# https://sourceware.org/pipermail/libc-alpha/2021-October/132029.html)
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# For us, this is the same as self.Elf_addr (or self.Elf_xword).
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self.Elf_Relr = Struct('Elf_Relr', self.Elf_addr('r_offset'))
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def _create_dyn(self):
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d_tag_dict = dict(ENUM_D_TAG_COMMON)
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if self.e_machine in ENUMMAP_EXTRA_D_TAG_MACHINE:
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d_tag_dict.update(ENUMMAP_EXTRA_D_TAG_MACHINE[self.e_machine])
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elif self.e_ident_osabi == 'ELFOSABI_SOLARIS':
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d_tag_dict.update(ENUM_D_TAG_SOLARIS)
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self.Elf_Dyn = Struct('Elf_Dyn',
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Enum(self.Elf_sxword('d_tag'), **d_tag_dict),
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self.Elf_xword('d_val'),
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Value('d_ptr', lambda ctx: ctx['d_val']),
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)
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def _create_sym(self):
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# st_info is hierarchical. To access the type, use
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# container['st_info']['type']
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st_info_struct = BitStruct('st_info',
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Enum(BitField('bind', 4), **ENUM_ST_INFO_BIND),
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Enum(BitField('type', 4), **ENUM_ST_INFO_TYPE))
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# st_other is hierarchical. To access the visibility,
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# use container['st_other']['visibility']
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st_other_struct = BitStruct('st_other',
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# https://openpowerfoundation.org/wp-content/uploads/2016/03/ABI64BitOpenPOWERv1.1_16July2015_pub4.pdf
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# See 3.4.1 Symbol Values.
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Enum(BitField('local', 3), **ENUM_ST_LOCAL),
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Padding(2),
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Enum(BitField('visibility', 3), **ENUM_ST_VISIBILITY))
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if self.elfclass == 32:
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self.Elf_Sym = Struct('Elf_Sym',
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self.Elf_word('st_name'),
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self.Elf_addr('st_value'),
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self.Elf_word('st_size'),
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st_info_struct,
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st_other_struct,
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Enum(self.Elf_half('st_shndx'), **ENUM_ST_SHNDX),
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)
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else:
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self.Elf_Sym = Struct('Elf_Sym',
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self.Elf_word('st_name'),
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st_info_struct,
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st_other_struct,
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Enum(self.Elf_half('st_shndx'), **ENUM_ST_SHNDX),
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self.Elf_addr('st_value'),
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self.Elf_xword('st_size'),
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)
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|
|
def _create_sunw_syminfo(self):
|
||
|
|
self.Elf_Sunw_Syminfo = Struct('Elf_Sunw_Syminfo',
|
||
|
|
Enum(self.Elf_half('si_boundto'), **ENUM_SUNW_SYMINFO_BOUNDTO),
|
||
|
|
self.Elf_half('si_flags'),
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_gnu_verneed(self):
|
||
|
|
# Structure of "version needed" entries is documented in
|
||
|
|
# Oracle "Linker and Libraries Guide", Chapter 13 Object File Format
|
||
|
|
self.Elf_Verneed = Struct('Elf_Verneed',
|
||
|
|
self.Elf_half('vn_version'),
|
||
|
|
self.Elf_half('vn_cnt'),
|
||
|
|
self.Elf_word('vn_file'),
|
||
|
|
self.Elf_word('vn_aux'),
|
||
|
|
self.Elf_word('vn_next'),
|
||
|
|
)
|
||
|
|
self.Elf_Vernaux = Struct('Elf_Vernaux',
|
||
|
|
self.Elf_word('vna_hash'),
|
||
|
|
self.Elf_half('vna_flags'),
|
||
|
|
self.Elf_half('vna_other'),
|
||
|
|
self.Elf_word('vna_name'),
|
||
|
|
self.Elf_word('vna_next'),
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_gnu_verdef(self):
|
||
|
|
# Structure of "version definition" entries are documented in
|
||
|
|
# Oracle "Linker and Libraries Guide", Chapter 13 Object File Format
|
||
|
|
self.Elf_Verdef = Struct('Elf_Verdef',
|
||
|
|
self.Elf_half('vd_version'),
|
||
|
|
self.Elf_half('vd_flags'),
|
||
|
|
self.Elf_half('vd_ndx'),
|
||
|
|
self.Elf_half('vd_cnt'),
|
||
|
|
self.Elf_word('vd_hash'),
|
||
|
|
self.Elf_word('vd_aux'),
|
||
|
|
self.Elf_word('vd_next'),
|
||
|
|
)
|
||
|
|
self.Elf_Verdaux = Struct('Elf_Verdaux',
|
||
|
|
self.Elf_word('vda_name'),
|
||
|
|
self.Elf_word('vda_next'),
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_gnu_versym(self):
|
||
|
|
# Structure of "version symbol" entries are documented in
|
||
|
|
# Oracle "Linker and Libraries Guide", Chapter 13 Object File Format
|
||
|
|
self.Elf_Versym = Struct('Elf_Versym',
|
||
|
|
Enum(self.Elf_half('ndx'), **ENUM_VERSYM),
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_gnu_abi(self):
|
||
|
|
# Structure of GNU ABI notes is documented in
|
||
|
|
# https://code.woboq.org/userspace/glibc/csu/abi-note.S.html
|
||
|
|
self.Elf_abi = Struct('Elf_abi',
|
||
|
|
Enum(self.Elf_word('abi_os'), **ENUM_NOTE_ABI_TAG_OS),
|
||
|
|
self.Elf_word('abi_major'),
|
||
|
|
self.Elf_word('abi_minor'),
|
||
|
|
self.Elf_word('abi_tiny'),
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_gnu_debugaltlink(self):
|
||
|
|
self.Elf_debugaltlink = Struct('Elf_debugaltlink',
|
||
|
|
CString("sup_filename"),
|
||
|
|
String("sup_checksum", length=20))
|
||
|
|
|
||
|
|
def _create_gnu_property(self):
|
||
|
|
# Structure of GNU property notes is documented in
|
||
|
|
# https://github.com/hjl-tools/linux-abi/wiki/linux-abi-draft.pdf
|
||
|
|
def roundup_padding(ctx):
|
||
|
|
if self.elfclass == 32:
|
||
|
|
return roundup(ctx.pr_datasz, 2) - ctx.pr_datasz
|
||
|
|
return roundup(ctx.pr_datasz, 3) - ctx.pr_datasz
|
||
|
|
|
||
|
|
def classify_pr_data(ctx):
|
||
|
|
if type(ctx.pr_type) is not str:
|
||
|
|
return None
|
||
|
|
if ctx.pr_type.startswith('GNU_PROPERTY_X86_'):
|
||
|
|
return ('GNU_PROPERTY_X86_*', 4, 0)
|
||
|
|
return (ctx.pr_type, ctx.pr_datasz, self.elfclass)
|
||
|
|
|
||
|
|
self.Elf_Prop = Struct('Elf_Prop',
|
||
|
|
Enum(self.Elf_word('pr_type'), **ENUM_NOTE_GNU_PROPERTY_TYPE),
|
||
|
|
self.Elf_word('pr_datasz'),
|
||
|
|
Switch('pr_data', classify_pr_data, {
|
||
|
|
('GNU_PROPERTY_STACK_SIZE', 4, 32): self.Elf_word('pr_data'),
|
||
|
|
('GNU_PROPERTY_STACK_SIZE', 8, 64): self.Elf_word64('pr_data'),
|
||
|
|
('GNU_PROPERTY_X86_*', 4, 0): self.Elf_word('pr_data'),
|
||
|
|
},
|
||
|
|
default=Field('pr_data', lambda ctx: ctx.pr_datasz)
|
||
|
|
),
|
||
|
|
Padding(roundup_padding)
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_note(self, e_type=None):
|
||
|
|
# Structure of "PT_NOTE" section
|
||
|
|
|
||
|
|
self.Elf_ugid = self.Elf_half if self.elfclass == 32 and self.e_machine in {
|
||
|
|
'EM_MN10300',
|
||
|
|
'EM_ARM',
|
||
|
|
'EM_CRIS',
|
||
|
|
'EM_CYGNUS_FRV',
|
||
|
|
'EM_386',
|
||
|
|
'EM_M32R',
|
||
|
|
'EM_68K',
|
||
|
|
'EM_S390',
|
||
|
|
'EM_SH',
|
||
|
|
'EM_SPARC',
|
||
|
|
} else self.Elf_word
|
||
|
|
|
||
|
|
self.Elf_Nhdr = Struct('Elf_Nhdr',
|
||
|
|
self.Elf_word('n_namesz'),
|
||
|
|
self.Elf_word('n_descsz'),
|
||
|
|
Enum(self.Elf_word('n_type'),
|
||
|
|
**(ENUM_NOTE_N_TYPE if e_type != "ET_CORE"
|
||
|
|
else ENUM_CORE_NOTE_N_TYPE)),
|
||
|
|
)
|
||
|
|
|
||
|
|
# A process psinfo structure according to
|
||
|
|
# http://elixir.free-electrons.com/linux/v2.6.35/source/include/linux/elfcore.h#L84
|
||
|
|
if self.elfclass == 32:
|
||
|
|
self.Elf_Prpsinfo = Struct('Elf_Prpsinfo',
|
||
|
|
self.Elf_byte('pr_state'),
|
||
|
|
String('pr_sname', 1),
|
||
|
|
self.Elf_byte('pr_zomb'),
|
||
|
|
self.Elf_byte('pr_nice'),
|
||
|
|
self.Elf_xword('pr_flag'),
|
||
|
|
self.Elf_ugid('pr_uid'),
|
||
|
|
self.Elf_ugid('pr_gid'),
|
||
|
|
self.Elf_word('pr_pid'),
|
||
|
|
self.Elf_word('pr_ppid'),
|
||
|
|
self.Elf_word('pr_pgrp'),
|
||
|
|
self.Elf_word('pr_sid'),
|
||
|
|
String('pr_fname', 16),
|
||
|
|
String('pr_psargs', 80),
|
||
|
|
)
|
||
|
|
else: # 64
|
||
|
|
self.Elf_Prpsinfo = Struct('Elf_Prpsinfo',
|
||
|
|
self.Elf_byte('pr_state'),
|
||
|
|
String('pr_sname', 1),
|
||
|
|
self.Elf_byte('pr_zomb'),
|
||
|
|
self.Elf_byte('pr_nice'),
|
||
|
|
Padding(4),
|
||
|
|
self.Elf_xword('pr_flag'),
|
||
|
|
self.Elf_ugid('pr_uid'),
|
||
|
|
self.Elf_ugid('pr_gid'),
|
||
|
|
self.Elf_word('pr_pid'),
|
||
|
|
self.Elf_word('pr_ppid'),
|
||
|
|
self.Elf_word('pr_pgrp'),
|
||
|
|
self.Elf_word('pr_sid'),
|
||
|
|
String('pr_fname', 16),
|
||
|
|
String('pr_psargs', 80),
|
||
|
|
)
|
||
|
|
|
||
|
|
# A PT_NOTE of type NT_FILE matching the definition in
|
||
|
|
# https://chromium.googlesource.com/
|
||
|
|
# native_client/nacl-binutils/+/upstream/master/binutils/readelf.c
|
||
|
|
# Line 15121
|
||
|
|
self.Elf_Nt_File = Struct('Elf_Nt_File',
|
||
|
|
self.Elf_xword("num_map_entries"),
|
||
|
|
self.Elf_xword("page_size"),
|
||
|
|
Array(lambda ctx: ctx.num_map_entries,
|
||
|
|
Struct('Elf_Nt_File_Entry',
|
||
|
|
self.Elf_addr('vm_start'),
|
||
|
|
self.Elf_addr('vm_end'),
|
||
|
|
self.Elf_offset('page_offset'))),
|
||
|
|
Array(lambda ctx: ctx.num_map_entries,
|
||
|
|
CString('filename')))
|
||
|
|
|
||
|
|
def _create_stabs(self):
|
||
|
|
# Structure of one stabs entry, see binutils/bfd/stabs.c
|
||
|
|
# Names taken from https://sourceware.org/gdb/current/onlinedocs/stabs.html#Overview
|
||
|
|
self.Elf_Stabs = Struct('Elf_Stabs',
|
||
|
|
self.Elf_word('n_strx'),
|
||
|
|
self.Elf_byte('n_type'),
|
||
|
|
self.Elf_byte('n_other'),
|
||
|
|
self.Elf_half('n_desc'),
|
||
|
|
self.Elf_word('n_value'),
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_attributes_subsection(self):
|
||
|
|
# Structure of a build attributes subsection header. A subsection is
|
||
|
|
# either public to all tools that process the ELF file or private to
|
||
|
|
# the vendor's tools.
|
||
|
|
self.Elf_Attr_Subsection_Header = Struct('Elf_Attr_Subsection',
|
||
|
|
self.Elf_word('length'),
|
||
|
|
self.Elf_ntbs('vendor_name',
|
||
|
|
encoding='utf-8')
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_arm_attributes(self):
|
||
|
|
# Structure of an ARM build attribute tag.
|
||
|
|
self.Elf_Arm_Attribute_Tag = Struct('Elf_Arm_Attribute_Tag',
|
||
|
|
Enum(self.Elf_uleb128('tag'),
|
||
|
|
**ENUM_ATTR_TAG_ARM)
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_riscv_attributes(self):
|
||
|
|
# Structure of a RISC-V build attribute tag.
|
||
|
|
self.Elf_RiscV_Attribute_Tag = Struct('Elf_RiscV_Attribute_Tag',
|
||
|
|
Enum(self.Elf_uleb128('tag'),
|
||
|
|
**ENUM_ATTR_TAG_RISCV)
|
||
|
|
)
|
||
|
|
|
||
|
|
def _create_elf_hash(self):
|
||
|
|
# Structure of the old SYSV-style hash table header. It is documented
|
||
|
|
# in the Oracle "Linker and Libraries Guide", Part IV ELF Application
|
||
|
|
# Binary Interface, Chapter 14 Object File Format, Section Hash Table
|
||
|
|
# Section:
|
||
|
|
# https://docs.oracle.com/cd/E53394_01/html/E54813/chapter6-48031.html
|
||
|
|
|
||
|
|
self.Elf_Hash = Struct('Elf_Hash',
|
||
|
|
self.Elf_word('nbuckets'),
|
||
|
|
self.Elf_word('nchains'),
|
||
|
|
Array(lambda ctx: ctx['nbuckets'], self.Elf_word('buckets')),
|
||
|
|
Array(lambda ctx: ctx['nchains'], self.Elf_word('chains')))
|
||
|
|
|
||
|
|
def _create_gnu_hash(self):
|
||
|
|
# Structure of the GNU-style hash table header. Documentation for this
|
||
|
|
# table is mostly in the GLIBC source code, a good explanation of the
|
||
|
|
# format can be found in this blog post:
|
||
|
|
# https://flapenguin.me/2017/05/10/elf-lookup-dt-gnu-hash/
|
||
|
|
self.Gnu_Hash = Struct('Gnu_Hash',
|
||
|
|
self.Elf_word('nbuckets'),
|
||
|
|
self.Elf_word('symoffset'),
|
||
|
|
self.Elf_word('bloom_size'),
|
||
|
|
self.Elf_word('bloom_shift'),
|
||
|
|
Array(lambda ctx: ctx['bloom_size'], self.Elf_xword('bloom')),
|
||
|
|
Array(lambda ctx: ctx['nbuckets'], self.Elf_word('buckets')))
|