os, syscall: remove fallback to pipe syscall on Linux

The minimum required Linux kernel version for Go 1.18 will be changed to
2.6.32, see #45964. The pipe2 syscall was added in 2.6.27, so the
fallback to use the pipe syscall in os.Pipe and syscall.forkExecPipe on
Linux can be removed.

For #45964

Change-Id: I033a534f2b39e9bafc9980c9ce980e92f1e3a136
Reviewed-on: https://go-review.googlesource.com/c/go/+/346789
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit is contained in:
Tobias Klauser 2021-09-01 14:57:18 +02:00 committed by Tobias Klauser
parent 840b4292c9
commit d13d62c49a
2 changed files with 2 additions and 27 deletions

View file

@ -12,20 +12,7 @@ func Pipe() (r *File, w *File, err error) {
var p [2]int
e := syscall.Pipe2(p[0:], syscall.O_CLOEXEC)
// pipe2 was added in 2.6.27 and our minimum requirement is 2.6.23, so it
// might not be implemented.
if e == syscall.ENOSYS {
// See ../syscall/exec.go for description of lock.
syscall.ForkLock.RLock()
e = syscall.Pipe(p[0:])
if e != nil {
syscall.ForkLock.RUnlock()
return nil, nil, NewSyscallError("pipe", e)
}
syscall.CloseOnExec(p[0])
syscall.CloseOnExec(p[1])
syscall.ForkLock.RUnlock()
} else if e != nil {
if e != nil {
return nil, nil, NewSyscallError("pipe2", e)
}

View file

@ -553,19 +553,7 @@ childerror:
// Try to open a pipe with O_CLOEXEC set on both file descriptors.
func forkExecPipe(p []int) (err error) {
err = Pipe2(p, O_CLOEXEC)
// pipe2 was added in 2.6.27 and our minimum requirement is 2.6.23, so it
// might not be implemented.
if err == ENOSYS {
if err = Pipe(p); err != nil {
return
}
if _, err = fcntl(p[0], F_SETFD, FD_CLOEXEC); err != nil {
return
}
_, err = fcntl(p[1], F_SETFD, FD_CLOEXEC)
}
return
return Pipe2(p, O_CLOEXEC)
}
func formatIDMappings(idMap []SysProcIDMap) []byte {