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, 23 deletions

diff --git a/src/syscall/syscall_linux_mipsx.go b/src/syscall/syscall_linux_mipsx.go
index 39104d71d8..568523eb27 100644
--- a/src/syscall/syscall_linux_mipsx.go
+++ b/src/syscall/syscall_linux_mipsx.go
@@ -112,29 +112,6 @@ func setTimeval(sec, usec int64) Timeval {
 	return Timeval{Sec: int32(sec), Usec: int32(usec)}
 }
 
-//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
-}
-
-//sysnb pipe() (p1 int, p2 int, err error)
-
-func Pipe(p []int) (err error) {
-	if len(p) != 2 {
-		return EINVAL
-	}
-	p[0], p[1], err = pipe()
-	return
-}
-
 //sys	mmap2(addr uintptr, length uintptr, prot int, flags int, fd int, pageOffset uintptr) (xaddr uintptr, err error)
 
 func mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error) {