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all: switch linux-ppc64 target to ELFv2 ABI

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Go is only capable of producing internally linked, static binaries
on linux-ppc64. As such, binaries should run in either ELFv1 or
ELFv2 ppc64 userspaces today.

This opens the door to enabling cgo and external linking which
will require ELFv2 support and userspace, eventually.

Fixes #76244

Change-Id: I5ca15037cbe546f352e8693dcf14da51a308b8ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/734540
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
This commit is contained in:
Paul Murphy 2026-01-07 13:48:53 -06:00
parent afae853072
commit 35c5deb1d4
5 changed files with 24 additions and 61 deletions
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15
src/cmd/link/internal/ld/elf.go
View file

@ -178,14 +178,7 @@ func Elfinit(ctxt *Link) {
switch ctxt.Arch.Family {
// 64-bit architectures
case sys.PPC64, sys.S390X:
if ctxt.Arch.ByteOrder == binary.BigEndian && ctxt.HeadType != objabi.Hopenbsd {
ehdr.Flags = 1 // Version 1 ABI
} else {
ehdr.Flags = 2 // Version 2 ABI
}
fallthrough
case sys.AMD64, sys.ARM64, sys.Loong64, sys.MIPS64, sys.RISCV64:
case sys.AMD64, sys.ARM64, sys.Loong64, sys.MIPS64, sys.PPC64, sys.RISCV64, sys.S390X:
if ctxt.Arch.Family == sys.MIPS64 {
ehdr.Flags = 0x20000004 // MIPS 3 CPIC
}
@ -195,6 +188,12 @@ func Elfinit(ctxt *Link) {
if ctxt.Arch.Family == sys.RISCV64 {
ehdr.Flags = 0x4 // RISCV Float ABI Double
}
if ctxt.Arch.Family == sys.S390X {
ehdr.Flags = 1 // Version 1 ABI
}
if ctxt.Arch.Family == sys.PPC64 {
ehdr.Flags = 2 // Version 2 ABI
}
elf64 = true
ehdr.Phoff = ELF64HDRSIZE // Must be ELF64HDRSIZE: first PHdr must follow ELF header

16
src/runtime/asm_ppc64x.h
View file

@ -37,19 +37,3 @@
GLOBL funcname(SB), NOPTR, $24
#endif
#endif
// linux/ppc64 uses ELFv1 which uses function descriptors.
// These must also look like ABI0 functions on linux/ppc64
// to work with abi.FuncPCABI0(sigtramp) in os_linux.go.
// Only static codegen is supported on linux/ppc64, so TOC
// is not needed.
#ifdef GOOS_linux
#ifdef GOARCH_ppc64
#define GO_PPC64X_HAS_FUNCDESC
#define DEFINE_PPC64X_FUNCDESC(funcname, localfuncname) \
TEXT funcname(SB),NOSPLIT|NOFRAME,$0 \
DWORD $localfuncname(SB) \
DWORD $0 \
DWORD $0
#endif
#endif

28
src/runtime/rt0_linux_ppc64.s
View file

@ -1,28 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "textflag.h"
#include "asm_ppc64x.h"
DEFINE_PPC64X_FUNCDESC(_rt0_ppc64_linux, _main<>)
DEFINE_PPC64X_FUNCDESC(main, _main<>)
TEXT _main<>(SB),NOSPLIT,$-8
// In a statically linked binary, the stack contains argc,
// argv as argc string pointers followed by a NULL, envv as a
// sequence of string pointers followed by a NULL, and auxv.
// There is no TLS base pointer.
//
// TODO(austin): Support ABI v1 dynamic linking entry point
XOR R0, R0 // Note, newer kernels may not always set R0 to 0.
MOVD $runtime·rt0_go(SB), R12
MOVD R12, CTR
MOVBZ runtime·iscgo(SB), R5
CMP R5, $0
BEQ nocgo
BR (CTR)
nocgo:
MOVD 0(R1), R3 // argc
ADD $8, R1, R4 // argv
BR (CTR)

14
src/runtime/rt0_linux_ppc64le.s → src/runtime/rt0_linux_ppc64x.s
View file

@ -2,15 +2,25 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (ppc64 || ppc64le) && linux
#include "go_asm.h"
#include "textflag.h"
#include "asm_ppc64x.h"
TEXT _rt0_ppc64le_linux(SB),NOSPLIT,$0
#ifdef GOARCH_ppc64
#define ENTRYPOINT _rt0_ppc64_linux
#define ENTRYPOINT_LIB _rt0_ppc64_linux_lib
#else
#define ENTRYPOINT _rt0_ppc64le_linux
#define ENTRYPOINT_LIB _rt0_ppc64le_linux_lib
#endif
TEXT ENTRYPOINT(SB),NOSPLIT,$0
XOR R0, R0 // Make sure R0 is zero before _main
BR _main<>(SB)
TEXT _rt0_ppc64le_linux_lib(SB),NOSPLIT|NOFRAME,$0
TEXT ENTRYPOINT_LIB(SB),NOSPLIT|NOFRAME,$0
JMP _rt0_ppc64x_lib(SB)
TEXT _main<>(SB),NOSPLIT,$-8

12
src/runtime/sys_linux_ppc64x.s
View file

@ -447,13 +447,12 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
MOVD 24(R1), R2
RET
#ifdef GO_PPC64X_HAS_FUNCDESC
DEFINE_PPC64X_FUNCDESC(runtime·sigtramp, sigtramp<>)
#ifdef GOARCH_ppc64
// cgo isn't supported on ppc64, but we need to supply a cgoSigTramp function.
DEFINE_PPC64X_FUNCDESC(runtime·cgoSigtramp, sigtramp<>)
TEXT sigtramp<>(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
#else
// ppc64le doesn't need function descriptors
TEXT runtime·cgoSigtramp(SB),NOSPLIT|NOFRAME,$0
BR runtime·sigtramp(SB)
#endif
// Save callee-save registers in the case of signal forwarding.
// Same as on ARM64 https://golang.org/issue/31827 .
//
@ -461,7 +460,6 @@ TEXT sigtramp<>(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
// a function pointer) as R2 may not be preserved when calling this
// function. In those cases, the caller preserves their R2.
TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0
#endif
// This is called with ELF calling conventions. Convert to Go.
// Allocate space for argument storage to call runtime.sigtrampgo.
STACK_AND_SAVE_HOST_TO_GO_ABI(32)