From a1938435d6361dcbc93a15ce0ace28748a45b85d Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Mon, 6 Sep 2021 19:02:34 +0200 Subject: [PATCH] syscall: use dup3 in forkAndExecInChild1 on all Linux platforms The minimum required Linux kernel version for Go 1.18 will be changed to 2.6.32, see #45964. The dup3 syscall was added in 2.6.27, so the fallback to use the dup2 syscall in forkAndExecInChild1 on some platforms can be removed. For #45964 Change-Id: I8e04d7b5b2488990a061a080ed64ea303ad048b8 Reviewed-on: https://go-review.googlesource.com/c/go/+/347350 Trust: Tobias Klauser Run-TryBot: Tobias Klauser Reviewed-by: Ian Lance Taylor TryBot-Result: Go Bot --- src/syscall/exec_linux.go | 18 +++--------------- src/syscall/syscall_dup2_linux.go | 11 ----------- src/syscall/syscall_dup3_linux.go | 10 ---------- 3 files changed, 3 insertions(+), 36 deletions(-) delete mode 100644 src/syscall/syscall_dup2_linux.go delete mode 100644 src/syscall/syscall_dup3_linux.go diff --git a/src/syscall/exec_linux.go b/src/syscall/exec_linux.go index 68bce7559b9..dfc52285456 100644 --- a/src/syscall/exec_linux.go +++ b/src/syscall/exec_linux.go @@ -448,13 +448,7 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att // so that pass 2 won't stomp on an fd it needs later. if pipe < nextfd { _, _, err1 = RawSyscall(SYS_DUP3, uintptr(pipe), uintptr(nextfd), O_CLOEXEC) - if _SYS_dup != SYS_DUP3 && err1 == ENOSYS { - _, _, err1 = RawSyscall(_SYS_dup, uintptr(pipe), uintptr(nextfd), 0) - if err1 != 0 { - goto childerror - } - RawSyscall(fcntl64Syscall, uintptr(nextfd), F_SETFD, FD_CLOEXEC) - } else if err1 != 0 { + if err1 != 0 { goto childerror } pipe = nextfd @@ -466,13 +460,7 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att nextfd++ } _, _, err1 = RawSyscall(SYS_DUP3, uintptr(fd[i]), uintptr(nextfd), O_CLOEXEC) - if _SYS_dup != SYS_DUP3 && err1 == ENOSYS { - _, _, err1 = RawSyscall(_SYS_dup, uintptr(fd[i]), uintptr(nextfd), 0) - if err1 != 0 { - goto childerror - } - RawSyscall(fcntl64Syscall, uintptr(nextfd), F_SETFD, FD_CLOEXEC) - } else if err1 != 0 { + if err1 != 0 { goto childerror } fd[i] = nextfd @@ -497,7 +485,7 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att } // The new fd is created NOT close-on-exec, // which is exactly what we want. - _, _, err1 = RawSyscall(_SYS_dup, uintptr(fd[i]), uintptr(i), 0) + _, _, err1 = RawSyscall(SYS_DUP3, uintptr(fd[i]), uintptr(i), 0) if err1 != 0 { goto childerror } diff --git a/src/syscall/syscall_dup2_linux.go b/src/syscall/syscall_dup2_linux.go deleted file mode 100644 index 351a96edc18..00000000000 --- a/src/syscall/syscall_dup2_linux.go +++ /dev/null @@ -1,11 +0,0 @@ -// Copyright 2020 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. - -//go:build !android && (386 || amd64 || arm || mips || mipsle || mips64 || mips64le || ppc64 || ppc64le || s390x) -// +build !android -// +build 386 amd64 arm mips mipsle mips64 mips64le ppc64 ppc64le s390x - -package syscall - -const _SYS_dup = SYS_DUP2 diff --git a/src/syscall/syscall_dup3_linux.go b/src/syscall/syscall_dup3_linux.go deleted file mode 100644 index 66ec67b0ab4..00000000000 --- a/src/syscall/syscall_dup3_linux.go +++ /dev/null @@ -1,10 +0,0 @@ -// Copyright 2020 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. - -//go:build android || arm64 || riscv64 -// +build android arm64 riscv64 - -package syscall - -const _SYS_dup = SYS_DUP3