x64: Relocation Types

The relocations that are listed in the following table are defined for x64.

Table 14-19 x64: ELF Relocation Types

Name	Value	Field	Calculation
R_AMD64_NONE	0	None	None
R_AMD64_64	1	word64	S + A
R_AMD64_PC32	2	word32	S + A - P
R_AMD64_GOT32	3	word32	G + A
R_AMD64_PLT32	4	word32	L + A - P
R_AMD64_COPY	5	None	Refer to the explanation following this table.
R_AMD64_GLOB_DAT	6	word64	S
R_AMD64_JUMP_SLOT	7	word64	S
R_AMD64_RELATIVE	8	word64	B + A
R_AMD64_GOTPCREL	9	word32	G + GOT + A - P
R_AMD64_32	10	word32	S + A
R_AMD64_32S	11	word32	S + A
R_AMD64_16	12	word16	S + A
R_AMD64_PC16	13	word16	S + A - P
R_AMD64_8	14	word8	S + A
R_AMD64_PC8	15	word8	S + A - P
R_AMD64_PC64	24	word64	S + A - P
R_AMD64_GOTOFF64	25	word64	S + A - GOT
R_AMD64_GOTPC32	26	word32	GOT + A + P
R_AMD64_SIZE32	32	word32	Z + A
R_AMD64_SIZE64	33	word64	Z + A

Note:

Additional relocations are available for thread-local storage references. These relocations are covered in Thread-Local Storage.

The special semantics for most of these relocation types are identical to those used for x86. Some relocation types have semantics beyond simple calculation.

R_AMD64_GOTPCREL

This relocations has different semantics from the R_AMD64_GOT32 or equivalent R_386_GOTPC relocation. The x64 architecture provides an addressing mode that is relative to the instruction pointer. Therefore, an address can be loaded from the GOT using a single instruction.

The calculation for the R_AMD64_GOTPCREL relocation provides the difference between the location in the GOT where the symbol's address is given, and the location where the relocation is applied.

R_AMD64_32

The computed value is truncated to 32 bits. The link-editor verifies that the generated value for the relocation zero-extends to the original 64-bit value.

R_AMD64_32S

The computed value is truncated to 32 bits. The link-editor verifies that the generated value for the relocation sign-extends to the original 64-bit value.

R_AMD64_8, R_AMD64_16, R_AMD64_PC16, and R_AMD64_PC8

These relocations are not conformant to the x64 ABI, but are added here for documentation purposes. The R_AMD64_8 relocation truncates the computed value to 8-bits. The R_AMD64_16 relocation truncates the computed value to 16-bits.