SPARC: Thread-Local Storage Relocation Types (Linker and Libraries Guide)

Linker and Libraries Guide

SPARC: Thread-Local Storage Relocation Types

The TLS relocations listed in the following table are defined for SPARC. Descriptions in the table use the following notation:

@dtlndx(x): Allocates two contiguous entries in the global offset table to hold a TLS_index structure. This information is passed to __tls_get_addr(). The instruction referencing this entry is bound to the address of the first of the two GOT entries.
@tmndx(x): Allocates two contiguous entries in the global offset table to hold a TLS_index structure. This information is passed to __tls_get_addr(). The ti_tlsoffset field of this structure is set to 0, and the ti_moduleid is filled in at runtime. The call to __tls_get_addr() returns the starting offset of the dynamic TLS block.
@dtpoff(x): Calculates the tlsoffset relative to the TLS block.
@tpoff(x): Calculates the negative tlsoffset relative to the static TLS block. This value is added to the thread-pointer to calculate the TLS address.
@dtpmod(x): Calculates the object identifier of the object containing symbol S.

Table 8–7 SPARC: Thread-Local Storage Relocation Types


Name	Value	Field	Calculation
`R_SPARC_TLS_GD_HI22`	`56`	`T-simm22`	`@dtlndx(S + A) >> 10`
`R_SPARC_TLS_GD_LO10`	`57`	`T-simm13`	`@dtlndx(S + A) & 0x3ff`
`R_SPARC_TLS_GD_ADD`	`58`	None	See `R_SPARC_R_SPARC_TLS_GD_ADD`
`R_SPARC_TLS_GD_CALL`	`59`	`V-disp30`	See `R_SPARC_R_SPARC_TLS_GD_CALL`
`R_SPARC_TLS_LDM_HI22`	60	`T-simm22`	`@tmndx(S + A) >> 10`
`R_SPARC_TLS_LDM_LO10`	`61`	`T-simm13`	`@tmndx(S + A) & 0x3ff`
`R_SPARC_TLS_LDM_ADD`	62	None	See `R_SPARC_R_SPARC_TLS_LDM_ADD`
`R_SPARC_TLS_LDM_CALL`	`63`	`V-disp30`	See `R_SPARC_R_SPARC_TLS_LDM_CALL`
`R_SPARC_TLS_LDO_HIX22`	`64`	`T-simm22`	`@dtpoff(S + A) >> 10`
`R_SPARC_TLS_LDO_LOX10`	`65`	`T-simm13`	`@dtpoff(S + A) & 0x3ff`
`R_SPARC_TLS_LDO_ADD`	`66`	None	See `R_SPARC_R_SPARC_TLS_LDO_ADD`
`R_SPARC_TLS_IE_HI22`	`67`	`T-simm22`	`@got(@tpoff(S + A)) >> 10`
`R_SPARC_TLS_IE_LO10`	`68`	`T-simm13`	`@got(@tpoff(S + A)) & 0x3ff`
`R_SPARC_TLS_IE_LD`	`69`	None	See `R_SPARC_R_SPARC_TLS_IE_LD`
`R_SPARC_TLS_IE_LDX`	`70`	None	See `R_SPARC_R_SPARC_TLS_IE_LDX`
`R_SPARC_TLS_IE_ADD`	`71`	None	See `R_SPARC_R_SPARC_TLS_IE_ADD`
`R_SPARC_TLS_LE_HIX22`	`72`	`T-imm22`	`(@tpoff(S + A) ^0xffffffffffffffff) >> 10`
`R_SPARC_TLS_LE_LOX10`	`73`	`T-simm13`	`(@tpoff(S + A) & 0x3ff) \| 0x1c00`
`R_SPARC_TLS_DTPMOD32`	`74`	`V-word32`	`@dtpmod(S + A)`
`R_SPARC_TLS_DTPMOD64`	`75`	`V-word64`	`@dtpmod(S + A)`
`R_SPARC_TLS_DTPOFF32`	`76`	`V-word32`	`@dtpoff(S + A)`
`R_SPARC_TLS_DTPOFF64`	`77`	`V-word64`	`@dtpoff(S + A)`
`R_SPARC_TLS_TPOFF32`	`78`	`V-word32`	`@tpoff(S + A)`
`R_SPARC_TLS_TPOFF64`	`79`	`V-word64`	`@tpoff(S + A)`

Some relocation types have semantics beyond simple calculations:

R_SPARC_TLS_GD_ADD: This relocation tags the add instruction of a GD code sequence. The register used for the GOT-pointer is the first register in the sequence. The instruction tagged by this relocation comes before the call instruction tagged by the R_SPARC_TLS_GD_CALL relocation. This is used to transition between TLS models at link-edit time.
R_SPARC_TLS_GD_CALL: This relocation is handled as if it were a R_SPARC_WPLT30 relocation referencing the __tls_get_addr() function. This relocation is part of a GD code sequence.
R_SPARC_LDM_ADD: This relocation tags the first add instruction of a LD code sequence. The register used for the GOT-pointer is the first register in the sequence. The instruction tagged by this relocation comes before the call instruction tagged by the R_SPARC_TLS_GD_CALL relocation. This is used to transition between TLS models at link-edit time.
R_SPARC_LDM_CALL: This relocation is handled as if it were a R_SPARC_WPLT30 relocation referencing the __tls_get_addr() function. This relocation is part of a LD code sequence.
R_SPARC_LDO_ADD: This relocation tags the final add instruction in a LD code sequence. The register which contains the object address computed in the initial part of the code sequence is the first register in this instruction. This permits the link-editor to identify this register for code transformations.
R_SPARC_TLS_IE_LD: This relocation tags the ld instruction in the 32–bit IE code sequence. This is used to transition between TLS models at link-edit time.
R_SPARC_TLS_IE_LDX: This relocation tags the ldx instruction in the 64–bit IE code sequence. This is used to transition between TLS models at link-edit time.
R_SPARC_TLS_IE_ADD: This relocation tags the add instruction in the IE code sequence. The register that is used for the GOT-pointer is the first register in the sequence.