syscall: implement Pipe using pipe2 syscall on all linux platforms

Most architectures currently already implement Pipe using the pipe2
syscall. Only 386, amd64 and mips{,le} still use the pipe syscall.
However, some systems (e.g. Android seccomp policies) block that
syscall, see #40828 for an example.

The pipe2 syscall was added in Linux kernel version 2.6.27. The minimum
required Linux kernel version for Go 1.18 will be changed to 2.6.32
per #45964 so it is possible to unify the implementation of Pipe using
the pipe2 syscall.

For #45964

Change-Id: I8ed6a391300c95f3107b4ec6b27d320e42fb535b
Reviewed-on: https://go-review.googlesource.com/c/go/+/350530
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

1 files changed, 0 insertions, 24 deletions

diff --git a/src/syscall/syscall_linux_arm64.go b/src/syscall/syscall_linux_arm64.go
index 517723ae47..990e732f35 100644
--- a/src/syscall/syscall_linux_arm64.go
+++ b/src/syscall/syscall_linux_arm64.go
@@ -145,30 +145,6 @@ func utimes(path string, tv *[2]Timeval) (err error) {
 	return utimensat(_AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
 }
 
-func Pipe(p []int) (err error) {
-	if len(p) != 2 {
-		return EINVAL
-	}
-	var pp [2]_C_int
-	err = pipe2(&pp, 0)
-	p[0] = int(pp[0])
-	p[1] = int(pp[1])
-	return
-}
-
-//sysnb pipe2(p *[2]_C_int, flags int) (err error)
-
-func Pipe2(p []int, flags int) (err error) {
-	if len(p) != 2 {
-		return EINVAL
-	}
-	var pp [2]_C_int
-	err = pipe2(&pp, flags)
-	p[0] = int(pp[0])
-	p[1] = int(pp[1])
-	return
-}
-
 // Getrlimit prefers the prlimit64 system call. See issue 38604.
 func Getrlimit(resource int, rlim *Rlimit) error {
 	err := prlimit(0, resource, nil, rlim)