Editing Executable and Linkable Format (section)

=== Section header ===

{| class="wikitable"
! colspan="2" |Offset
! colspan="2" |Size (bytes)
! rowspan="2" |Field
! rowspan="2" |Purpose
|-
!32-bit
!64-bit
!32-bit
!64-bit
|-
| colspan="2" |0x00
| colspan="2" |4
| {{tt|sh_name}}
|An offset to a string in the '''.shstrtab''' section that represents the name of this section.
|-
| colspan="2" |0x04
| colspan="2" |4
| {{tt|sh_type}}
|Identifies the type of this header.
{| class="wikitable"
!Value
!Name
!Meaning
|-
| {{tt|0x0}}
| {{tt|SHT_NULL}}
|Section header table entry unused
|-
| {{tt|0x1}}
| {{tt|SHT_PROGBITS}}
|Program data
|-
| {{tt|0x2}}
| {{tt|SHT_SYMTAB}}
|Symbol table
|-
| {{tt|0x3}}
| {{tt|SHT_STRTAB}}
|String table
|-
| {{tt|0x4}}
| {{tt|SHT_RELA}}
|Relocation entries with addends
|-
| {{tt|0x5}}
| {{tt|SHT_HASH}}
|Symbol hash table
|-
| {{tt|0x6}}
| {{tt|SHT_DYNAMIC}}
|Dynamic linking information
|-
| {{tt|0x7}}
| {{tt|SHT_NOTE}}
|Notes
|-
| {{tt|0x8}}
| {{tt|SHT_NOBITS}}
|Program space with no data (bss)
|-
| {{tt|0x9}}
| {{tt|SHT_REL}}
|Relocation entries, no addends
|-
| {{tt|0x0A}}
| {{tt|SHT_SHLIB}}
|Reserved
|-
| {{tt|0x0B}}
| {{tt|SHT_DYNSYM}}
|Dynamic linker symbol table
|-
| {{tt|0x0E}}
| {{tt|SHT_INIT_ARRAY}}
|Array of constructors
|-
| {{tt|0x0F}}
| {{tt|SHT_FINI_ARRAY}}
|Array of destructors
|-
| {{tt|0x10}}
| {{tt|SHT_PREINIT_ARRAY}}
|Array of pre-constructors
|-
| {{tt|0x11}}
| {{tt|SHT_GROUP}}
|Section group
|-
| {{tt|0x12}}
| {{tt|SHT_SYMTAB_SHNDX}}
|Extended section indices
|-
| {{tt|0x13}}
| {{tt|SHT_NUM}}
|Number of defined types.
|-
| {{tt|0x60000000}}
| {{tt|SHT_LOOS}}
|Start OS-specific.
|-
|...
|...
|...
|}
|-
| colspan="2" |0x08
|4
|8
| {{tt|sh_flags}}
|Identifies the attributes of the section.
{| class="wikitable"
!Value
!Name
!Meaning
|-
| {{tt|0x1}}
| {{tt|SHF_WRITE}}
|Writable
|-
| {{tt|0x2}}
| {{tt|SHF_ALLOC}}
|Occupies memory during execution
|-
| {{tt|0x4}}
| {{tt|SHF_EXECINSTR}}
|Executable
|-
| {{tt|0x10}}
| {{tt|SHF_MERGE}}
|Might be merged
|-
| {{tt|0x20}}
| {{tt|SHF_STRINGS}}
|Contains null-terminated strings
|-
| {{tt|0x40}}
| {{tt|SHF_INFO_LINK}}
|'sh_info' contains SHT index
|-
| {{tt|0x80}}
| {{tt|SHF_LINK_ORDER}}
|Preserve order after combining
|-
| {{tt|0x100}}
| {{tt|SHF_OS_NONCONFORMING}}
|Non-standard OS specific handling required
|-
| {{tt|0x200}}
| {{tt|SHF_GROUP}}
|Section is member of a group
|-
| {{tt|0x400}}
| {{tt|SHF_TLS}}
|Section hold thread-local data
|-
| {{tt|0x0FF00000}}
| {{tt|SHF_MASKOS}}
|OS-specific
|-
| {{tt|0xF0000000}}
| {{tt|SHF_MASKPROC}}
|Processor-specific
|-
| {{tt|0x4000000}}
| {{tt|SHF_ORDERED}}
|Special ordering requirement (Solaris)
|-
| {{tt|0x8000000}}
| {{tt|SHF_EXCLUDE}}
|Section is excluded unless referenced or allocated (Solaris)
|}
|-
| {{tt|0x0C}}
| {{tt|0x10}}
|4
|8
| {{tt|sh_addr}}
|Virtual address of the section in memory, for sections that are loaded.
|-
| {{tt|0x10}}
| {{tt|0x18}}
|4
|8
| {{tt|sh_offset}}
|Offset of the section in the file image.
|-
| {{tt|0x14}}
| {{tt|0x20}}
|4
|8
| {{tt|sh_size}}
|Size in bytes of the section. May be 0.
|-
| {{tt|0x18}}
| {{tt|0x28}}
| colspan="2" |4
| {{tt|sh_link}}
|Contains the section index of an associated section. This field is used for several purposes, depending on the type of section.
|-
| {{tt|0x1C}}
| {{tt|0x2C}}
| colspan="2" |4
| {{tt|sh_info}}
|Contains extra information about the section. This field is used for several purposes, depending on the type of section.
|-
| {{tt|0x20}}
| {{tt|0x30}}
|4
|8
| {{tt|sh_addralign}}
|Contains the required alignment of the section. This field must be a power of two.
|-
| {{tt|0x24}}
| {{tt|0x38}}
|4
|8
| {{tt|sh_entsize}}
|Contains the size, in bytes, of each entry, for sections that contain fixed-size entries. Otherwise, this field contains zero.
|-
| {{tt|0x28}}
| {{tt|0x40}}
| colspan="3" |
|End of Section Header (size).
|}