[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While we're at it, remove the unused and in some cases out of date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 <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/16982
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/src/cmd/link/internal/amd64/asm.go b/src/cmd/link/internal/amd64/asm.go
index 74ec9dd3ea6ef8dc5e98b91a8f25ae726f2ccc82..4eb2092ec730d6ed25402478784cafbf0f2beee6 100644 (file)
--- 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 508f0554c7b9e4429ecb7c478310692d9cb7b9f4..c9a5c99c344ebcd66d9b44ea378896c6fdb4ae69 100644 (file)
--- 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 3efdb75b89fb048367f636aba3245227ecf71560..7ff37add77005b59f07389d30321c0937016653c 100644 (file)
--- 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 d30bd48b4e61d60f3016a58a6b2269802a6000a5..64953859765ae6108f322805687987707015ca13 100644 (file)
--- 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 {