Linux Standard Base Specification 1.2
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Version Requirements

Symbol definitions are contained in the special section .gnu.version_r which has a section type of SHT_GNU_verneed. The number of entries in this section is contained in the DT_VERNEEDNUM entry of the Dynamic Section. The sh_link member of the section header points to the section that contains the strings referenced by this section.

Figure 6-3. Version Needed Entries

typedef struct {
	Elfxx_Half    vn_version;
	Elfxx_Half    vn_cnt;
	Elfxx_Word    vn_file;
	Elfxx_Word    vn_aux;
	Elfxx_Word    vn_next;
} Elfxx_Verneed;

vn_version

Version of structure. This value is currently set to 1, and will be reset if the versioning implementation is incompatibly altered.

vn_cnt

Number of associated verneed array entries.

vn_file

Offset to the file name string in the section header, in bytes.

vn_aux

Offset to a corresponding entry in the vernaux array, in bytes.

vn_next

Offset to the next verneed entry, in bytes.

Figure 6-4. Version Needed Auxiliary Entries

typedef struct {
	Elfxx_Word    vna_hash;
	Elfxx_Half    vna_flags;
	Elfxx_Half    vna_other;
	Elfxx_Word    vna_name;
	Elfxx_Word    vna_next;
} Elfxx_Vernaux;

vna_hash

Dependency name hash value (ELF hash function).

vna_flags

Dependency information flag bitmask.

vna_other

Object file version identifier used in the .gnu.version symbol version array. Bit number 15 controls whether or not the object is hidden; if this bit is set, the object cannot be used and the static linker will ignore the symbol's presence in the object.

vna_name

Offset to the dependency name string in the section header, in bytes.

vna_next

Offset to the next vernaux entry, in bytes.

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