Special Sections

Various sections hold program and control information. Sections in the following table are used by the system and have the indicated types and attributes.

Table 7-17 ELF Special Sections

Name	Type	Attribute
.bss	SHT_NOBITS	SHF_ALLOC + SHF_WRITE
.comment	SHT_PROGBITS	None
.data	SHT_PROGBITS	SHF_ALLOC + SHF_WRITE
.data1	SHT_PROGBITS	SHF_ALLOC + SHF_WRITE
.dynamic	SHT_DYNAMIC	SHF_ALLOC + SHF_WRITE
.dynstr	SHT_STRTAB	SHF_ALLOC
.dynsym	SHT_DYNSYM	SHF_ALLOC
.fini	SHT_PROGBITS	SHF_ALLOC + SHF_EXECINSTR
.fini_array	SHT_FINI_ARRAY	SHF_ALLOC + SHF_WRITE
.got	SHT_PROGBITS	See “Global Offset Table (Processor-Specific)”
.hash	SHT_HASH	SHF_ALLOC
.init	SHT_PROGBITS	SHF_ALLOC + SHF_EXECINSTR
.init_array	SHT_INIT_ARRAY	SHF_ALLOC + SHF_WRITE
.interp	SHT_PROGBITS	See “Program Interpreter”
.note	SHT_NOTE	None
.plt	SHT_PROGBITS	See “Procedure Linkage Table (Processor-Specific)”
.preinit_array	SHT_PREINIT_ARRAY	SHF_ALLOC + SHF_WRITE
.rela	SHT_RELA	None
.relname	SHT_REL	See “Relocation”
.relaname	SHT_RELA	See “Relocation”
.rodata	SHT_PROGBITS	SHF_ALLOC
.rodata1	SHT_PROGBITS	SHF_ALLOC
.shstrtab	SHT_STRTAB	None
.strtab	SHT_STRTAB	See description below
.symtab	SHT_SYMTAB	See “Symbol Table”
.tbss	SHT_NOBITS	SHF_ALLOC + SHF_WRITE + SHF_TLS
.tdata	SHT_PROGBITS	SHF_ALLOC + SHF_WRITE + SHF_TLS
.tdata1	SHT_PROGBITS	SHF_ALLOC + SHF_WRITE + SHF_TLS
.text	SHT_PROGBITS	SHF_ALLOC + SHF_EXECINSTR
.SUNW_bss	SHT_NOBITS	SHF_ALLOC + SHF_WRITE
.SUNW_heap	SHT_PROGBITS	SHF_ALLOC + SHF_WRITE
.SUNW_move	SHT_SUNW_move	SHF_ALLOC
.SUNW_reloc	SHT_REL SHT_RELA	SHF_ALLOC
.SUNW_syminfo	SHT_SUNW_syminfo	SHF_ALLOC
.SUNW_version	SHT_SUNW_verdef SHT_SUNW_verneed SHT_SUNW_versym	SHF_ALLOC

.bss

Uninitialized data that contribute to the program's memory image. By definition, the system initializes the data with zeros when the program begins to run. The section occupies no file space, as indicated by the section type SHT_NOBITS.

.comment

Comment information, typically contributed by the components of the compilation system. This section can be manipulated by mcs(1).

.data, .data1

Initialized data that contribute to the program's memory image.

.dynamic

Dynamic linking information. See “Dynamic Section” for details.

.dynstr

Strings needed for dynamic linking, most commonly the strings that represent the names associated with symbol table entries.

.dynsym

Dynamic linking symbol table. See “Symbol Table” for details.

.fini

Executable instructions that contribute to a single termination function for the executable or shared object containing the section. See “Initialization and Termination Routines” for details.

.fini_array

An array of function pointers that contribute to a single termination array for the executable or shared object containing the section. See “Initialization and Termination Routines” for details.

.got

The global offset table. See “Global Offset Table (Processor-Specific)”.

.hash

Symbol hash table. See “Hash Table”.

.init

Executable instructions that contribute to a single initialization function for the executable or shared object containing the section. See “Initialization and Termination Routines” for details.

.init_array

An array of function pointers that contributes to a single initialization array for the executable or shared object containing the section. See “Initialization and Termination Routines” for details.

.interp

The path name of a program interpreter. See “Program Interpreter”.

.note

Information in the format described in “Note Section”.

.plt

The procedure linkage table. See “Procedure Linkage Table (Processor-Specific)”.

.preinit_array

An array of function pointers that contribute to a single pre-initialization array for the executable or shared object containing the section. See “Initialization and Termination Routines” for details.

.rela

Relocations that do not apply to a particular section. One use of this section is for register relocations. See “Register Symbols”.

.relname, .relaname

Relocation information, as “Relocation” describes. If the file has a loadable segment that includes relocation, the sections' attributes include the SHF_ALLOC bit. Otherwise, that bit is off. Conventionally, name is supplied by the section to which the relocations apply. Thus a relocation section for .text normally will have the name .rel.text or .rela.text.

.rodata, .rodata1

Read-only data that typically contribute to a non-writable segment in the process image. See “Program Header”.

.shstrtab

Section names.

.strtab

Strings, most commonly the strings that represent the names associated with symbol table entries. If the file has a loadable segment that includes the symbol string table, the section's attributes include the SHF_ALLOC bit. Otherwise, that bit is turned off.

.symtab

Symbol table, as “Symbol Table” describes. If the file has a loadable segment that includes the symbol table, the section's attributes include the SHF_ALLOC bit. Otherwise, that bit is turned off.

.tbss

This section holds uninitialized thread-local data that contribute to the program's memory image. By definition, the system initializes the data with zeros when the data is instantiated for each new execution flow. The section occupies no file space, as indicated by the section type, SHT_NOBITS. See “Thread-Local Storage” for more information.

.tdata, .tdata1

These sections hold initialized thread-local data that contribute to the program's memory image. A copy of its contents is instantiated by the system for each new execution flow. See “Thread-Local Storage” for more information.

.text

The text or executable instructions of a program.

.SUNW_bss

Partially initialized data for shared objects that contribute to the program's memory image. The data is initialized at runtime. The section occupies no file space, as indicated by the section type SHT_NOBITS.

.SUNW_heap

The heap of a dynamic executable created from dldump(3DL).

.SUNW_move

Additional information for partially initialized data. See “Move Section”.

.SUNW_reloc

Relocation information, as “Relocation” describes. This section is a concatenation of relocation sections that provides better locality of reference of the individual relocation records. Only the offset of the relocation record itself is meaningful, thus the section sh_info value is zero.

.SUNW_syminfo

Additional symbol table information. See “Syminfo Table”.

.SUNW_version

Versioning information. See “Versioning Information”.

Section names with a dot (.) prefix are reserved for the system, although applications can use these sections if their existing meanings are satisfactory. Applications can use names without the prefix to avoid conflicts with system sections. The object file format enables you to define sections not in the list above. An object file can have more than one section with the same name.

Section names reserved for a processor architecture are formed by placing an abbreviation of the architecture name ahead of the section name. The name should be taken from the architecture names used for e_machine. For example, .Foo.psect is the psect section defined by the FOO architecture.

Existing extensions use their historical names.