syscall: introduce IoctlPtr for exec_unix tests

Avoid passing Go pointers as uintptr in exec_unix_test.go by introducing
syscall.IoctlPtr() which accepts arg as unsafe.Pointer.

For #44834
Fixes #58609

Change-Id: I6d0ded023e5f3c9989783aee7075bb88100d9ec2
Reviewed-on: https://go-review.googlesource.com/c/go/+/469675
Run-TryBot: Dmitri Goutnik <dgoutnik@gmail.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>

src/syscall/exec_aix_test.go

@@ -34,4 +34,4 @@ func Getpgrp() (pgrp int) {
 	return
 }
 
-var Ioctl = ioctl
+var IoctlPtr = ioctlPtr

src/syscall/exec_libc.go

@@ -305,3 +305,7 @@ childerror:
 		exit(253)
 	}
 }
+
+func ioctlPtr(fd, req uintptr, arg unsafe.Pointer) (err Errno) {
+	return ioctl(fd, req, uintptr(arg))
+}

src/syscall/exec_solaris_test.go

@@ -34,4 +34,4 @@ func Getpgrp() (pgrp int) {
 	return
 }
 
-var Ioctl = ioctl
+var IoctlPtr = ioctlPtr

src/syscall/exec_unix_test.go

@@ -177,7 +177,7 @@ func TestForeground(t *testing.T) {
 	// equivalent.
 	fpgrp := int32(0)
 
-	errno := syscall.Ioctl(tty.Fd(), syscall.TIOCGPGRP, uintptr(unsafe.Pointer(&fpgrp)))
+	errno := syscall.IoctlPtr(tty.Fd(), syscall.TIOCGPGRP, unsafe.Pointer(&fpgrp))
 	if errno != 0 {
 		t.Fatalf("TIOCGPGRP failed with error code: %s", errno)
 	}
@@ -214,7 +214,7 @@ func TestForeground(t *testing.T) {
 
 	// This call fails on darwin/arm64. The failure doesn't matter, though.
 	// This is just best effort.
-	syscall.Ioctl(tty.Fd(), syscall.TIOCSPGRP, uintptr(unsafe.Pointer(&fpgrp)))
+	syscall.IoctlPtr(tty.Fd(), syscall.TIOCSPGRP, unsafe.Pointer(&fpgrp))
 }
 
 func TestForegroundSignal(t *testing.T) {
@@ -228,7 +228,7 @@ func TestForegroundSignal(t *testing.T) {
 	// equivalent.
 	fpgrp := int32(0)
 
-	errno := syscall.Ioctl(tty.Fd(), syscall.TIOCGPGRP, uintptr(unsafe.Pointer(&fpgrp)))
+	errno := syscall.IoctlPtr(tty.Fd(), syscall.TIOCGPGRP, unsafe.Pointer(&fpgrp))
 	if errno != 0 {
 		t.Fatalf("TIOCGPGRP failed with error code: %s", errno)
 	}
@@ -239,7 +239,7 @@ func TestForegroundSignal(t *testing.T) {
 
 	defer func() {
 		signal.Ignore(syscall.SIGTTIN, syscall.SIGTTOU)
-		syscall.Ioctl(tty.Fd(), syscall.TIOCSPGRP, uintptr(unsafe.Pointer(&fpgrp)))
+		syscall.IoctlPtr(tty.Fd(), syscall.TIOCSPGRP, unsafe.Pointer(&fpgrp))
 		signal.Reset()
 	}()
 

src/syscall/export_darwin_test.go

@@ -4,8 +4,10 @@
 
 package syscall
 
-func Ioctl(fd, req, arg uintptr) Errno {
-	err := ioctl(int(fd), int(req), int(arg))
+import "unsafe"
+
+func IoctlPtr(fd, req uintptr, arg unsafe.Pointer) Errno {
+	err := ioctlPtr(int(fd), uint(req), arg)
 	if err != nil {
 		return err.(Errno)
 	}

src/syscall/export_unix_test.go

@@ -6,7 +6,9 @@
 
 package syscall
 
-func Ioctl(fd, req, arg uintptr) (err Errno) {
-	_, _, err = Syscall(SYS_IOCTL, fd, req, arg)
+import "unsafe"
+
+func IoctlPtr(fd, req uintptr, arg unsafe.Pointer) (err Errno) {
+	_, _, err = Syscall(SYS_IOCTL, fd, req, uintptr(arg))
 	return err
 }