From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Tue, 6 Apr 2021 10:45:51 -0700
Subject: Fix ptsname() for big-endian architectures (again)

Origin: backport, https://github.com/containerd/console/pull/51
---
 tc_linux.go | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tc_linux.go b/tc_linux.go
index 75f8694..1bdd68e 100644
--- a/tc_linux.go
+++ b/tc_linux.go
@@ -19,6 +19,7 @@ package console
 import (
 	"fmt"
 	"os"
+	"unsafe"
 
 	"golang.org/x/sys/unix"
 )
@@ -31,13 +32,17 @@ const (
 // unlockpt unlocks the slave pseudoterminal device corresponding to the master pseudoterminal referred to by f.
 // unlockpt should be called before opening the slave side of a pty.
 func unlockpt(f *os.File) error {
-	return unix.IoctlSetPointerInt(int(f.Fd()), unix.TIOCSPTLCK, 0)
+	var u int32
+	if _, _, err := unix.Syscall(unix.SYS_IOCTL, f.Fd(), unix.TIOCSPTLCK, uintptr(unsafe.Pointer(&u))); err != 0 {
+		return err
+	}
+	return nil
 }
 
 // ptsname retrieves the name of the first available pts for the given master.
 func ptsname(f *os.File) (string, error) {
-	u, err := unix.IoctlGetInt(int(f.Fd()), unix.TIOCGPTN)
-	if err != nil {
+	var u uint32
+	if _, _, err := unix.Syscall(unix.SYS_IOCTL, f.Fd(), unix.TIOCGPTN, uintptr(unsafe.Pointer(&u))); err != 0 {
 		return "", err
 	}
 	return fmt.Sprintf("/dev/pts/%d", u), nil