From c0c730da28938b4ca920da67c5e143c007c505a7 Mon Sep 17 00:00:00 2001

From: Ian Lance Taylor <[email protected]>

Date: Sat, 31 Oct 2015 14:44:48 -0700

Subject: [PATCH 39/63] [release-branch.go1.5] cmd/link: support new 386/amd64

 relocations

The GNU binutils recently picked up support for new 386/amd64

relocations.  Add support for them in the Go linker when doing an

internal link.

The 386 relocation R_386_GOT32X was proposed in

https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I .  It can

be treated as identical to the R_386_GOT32 relocation.

The amd64 relocations R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX were

proposed in

https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0 .  They

can both be treated as identical to the R_X86_64_GOTPCREL relocation.

The purpose of the new relocations is to permit additional linker

relaxations in some cases.  We do not attempt to support those cases.

While we're at it, remove the unused and in some cases out of date

_COUNT names from ld/elf.go.

Fixes #13114.

Change-Id: I34ef07f6fcd00cdd2996038ecf46bb77a49e968b

Reviewed-on: https://go-review.googlesource.com/16529

Reviewed-by: Minux Ma <[email protected]>

Reviewed-on: https://go-review.googlesource.com/16982

Run-TryBot: Austin Clements <[email protected]>

Reviewed-by: Ian Lance Taylor <[email protected]>

Reviewed-by: Russ Cox <[email protected]>

---

 src/cmd/link/internal/amd64/asm.go |  2 +-

 src/cmd/link/internal/ld/elf.go    | 28 ++++++++++++++++++++++------

 src/cmd/link/internal/ld/ldelf.go  |  3 +++

 src/cmd/link/internal/x86/asm.go   |  2 +-

 4 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/cmd/link/internal/amd64/asm.go b/src/cmd/link/internal/amd64/asm.go

index 74ec9dd..4eb2092 100644

--- a/src/cmd/link/internal/amd64/asm.go

+++ b/src/cmd/link/internal/amd64/asm.go

@@ -141,7 +141,7 @@ func adddynrel(s *ld.LSym, r *ld.Reloc) {

 		return

-	case 256 + ld.R_X86_64_GOTPCREL:

+	case 256 + ld.R_X86_64_GOTPCREL, 256 + ld.R_X86_64_GOTPCRELX, 256 + ld.R_X86_64_REX_GOTPCRELX:

 		if targ.Type != obj.SDYNIMPORT {

 			// have symbol

 			if r.Off >= 2 && s.P[r.Off-2] == 0x8b {

diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go

index 508f055..c9a5c99 100644

--- a/src/cmd/link/internal/ld/elf.go

+++ b/src/cmd/link/internal/ld/elf.go

@@ -348,7 +348,23 @@ const (

 	R_X86_64_DTPOFF32          = 21

 	R_X86_64_GOTTPOFF          = 22

 	R_X86_64_TPOFF32           = 23

-	R_X86_64_COUNT             = 24

+	R_X86_64_PC64              = 24

+	R_X86_64_GOTOFF64          = 25

+	R_X86_64_GOTPC32           = 26

+	R_X86_64_GOT64             = 27

+	R_X86_64_GOTPCREL64        = 28

+	R_X86_64_GOTPC64           = 29

+	R_X86_64_GOTPLT64          = 30

+	R_X86_64_PLTOFF64          = 31

+	R_X86_64_SIZE32            = 32

+	R_X86_64_SIZE64            = 33

+	R_X86_64_GOTPC32_TLSDEC    = 34

+	R_X86_64_TLSDESC_CALL      = 35

+	R_X86_64_TLSDESC           = 36

+	R_X86_64_IRELATIVE         = 37

+	R_X86_64_PC32_BND          = 40

+	R_X86_64_GOTPCRELX         = 41

+	R_X86_64_REX_GOTPCRELX     = 42

 	R_AARCH64_ABS64            = 257

 	R_AARCH64_ABS32            = 258

 	R_AARCH64_CALL26           = 283

@@ -382,7 +398,6 @@ const (

 	R_ALPHA_GLOB_DAT           = 25

 	R_ALPHA_JMP_SLOT           = 26

 	R_ALPHA_RELATIVE           = 27

-	R_ALPHA_COUNT              = 28

 	R_ARM_NONE                 = 0

 	R_ARM_PC24                 = 1

 	R_ARM_ABS32                = 2

@@ -422,7 +437,6 @@ const (

 	R_ARM_RABS32               = 253

 	R_ARM_RPC24                = 254

 	R_ARM_RBASE                = 255

-	R_ARM_COUNT                = 38

 	R_386_NONE                 = 0

 	R_386_32                   = 1

 	R_386_PC32                 = 2

@@ -454,7 +468,11 @@ const (

 	R_386_TLS_DTPMOD32         = 35

 	R_386_TLS_DTPOFF32         = 36

 	R_386_TLS_TPOFF32          = 37

-	R_386_COUNT                = 38

+	R_386_TLS_GOTDESC          = 39

+	R_386_TLS_DESC_CALL        = 40

+	R_386_TLS_DESC             = 41

+	R_386_IRELATIVE            = 42

+	R_386_GOT32X               = 43

 	R_PPC_NONE                 = 0

 	R_PPC_ADDR32               = 1

 	R_PPC_ADDR24               = 2

@@ -492,7 +510,6 @@ const (

 	R_PPC_SECTOFF_LO           = 34

 	R_PPC_SECTOFF_HI           = 35

 	R_PPC_SECTOFF_HA           = 36

-	R_PPC_COUNT                = 37

 	R_PPC_TLS                  = 67

 	R_PPC_DTPMOD32             = 68

 	R_PPC_TPREL16              = 69

@@ -533,7 +550,6 @@ const (

 	R_PPC_EMB_RELST_HA         = 114

 	R_PPC_EMB_BIT_FLD          = 115

 	R_PPC_EMB_RELSDA           = 116

-	R_PPC_EMB_COUNT            = R_PPC_EMB_RELSDA - R_PPC_EMB_NADDR32 + 1

 	R_PPC64_REL24              = R_PPC_REL24

 	R_PPC64_JMP_SLOT           = R_PPC_JMP_SLOT

 	R_PPC64_ADDR64             = 38

diff --git a/src/cmd/link/internal/ld/ldelf.go b/src/cmd/link/internal/ld/ldelf.go

index 3efdb75..7ff37ad 100644

--- a/src/cmd/link/internal/ld/ldelf.go

+++ b/src/cmd/link/internal/ld/ldelf.go

@@ -1001,12 +1001,15 @@ func reltype(pn string, elftype int, siz *uint8) int {

 		'6' | R_X86_64_PC32<<24,

 		'6' | R_X86_64_PLT32<<24,

 		'6' | R_X86_64_GOTPCREL<<24,

+		'6' | R_X86_64_GOTPCRELX<<24,

+		'6' | R_X86_64_REX_GOTPCRELX<<24,

 		'8' | R_386_32<<24,

 		'8' | R_386_PC32<<24,

 		'8' | R_386_GOT32<<24,

 		'8' | R_386_PLT32<<24,

 		'8' | R_386_GOTOFF<<24,

 		'8' | R_386_GOTPC<<24,

+		'8' | R_386_GOT32X<<24,

 		'9' | R_PPC64_REL24<<24:

 		*siz = 4

diff --git a/src/cmd/link/internal/x86/asm.go b/src/cmd/link/internal/x86/asm.go

index d30bd48..6495385 100644

--- a/src/cmd/link/internal/x86/asm.go

+++ b/src/cmd/link/internal/x86/asm.go

@@ -78,7 +78,7 @@ func adddynrel(s *ld.LSym, r *ld.Reloc) {

 		return

-	case 256 + ld.R_386_GOT32:

+	case 256 + ld.R_386_GOT32, 256 + ld.R_386_GOT32X:

 		if targ.Type != obj.SDYNIMPORT {

 			// have symbol

 			if r.Off >= 2 && s.P[r.Off-2] == 0x8b {

-- 

2.6.1