internal/poll, internal/syscall/unix, net, runtime: convert openbsd (except mips64) to direct libc calls

Call libc wrappers directly rather than calling using syscall(2).

Updates golang/go#36435

Change-Id: I40be410c7472f7d89cbec2ebdc7c841c7726ca4a
Reviewed-on: https://go-review.googlesource.com/c/go/+/425637
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Joel Sing <joel@sing.id.au>

src/internal/poll/fcntl_libc.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build aix || darwin || solaris
+//go:build aix || darwin || (openbsd && !mips64) || solaris
 
 package poll
 

src/internal/poll/fcntl_syscall.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build dragonfly || freebsd || linux || netbsd || openbsd
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
 
 package poll
 

src/internal/syscall/unix/at.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux || openbsd || netbsd || dragonfly
+//go:build dragonfly || linux || netbsd || (openbsd && mips64)
 
 package unix
 

src/internal/syscall/unix/at_fstatat.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && !loong64) || openbsd || netbsd || dragonfly
+//go:build dragonfly || (linux && !loong64) || netbsd || (openbsd && mips64)
 
 package unix
 

src/internal/syscall/unix/at_libc2.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin || (openbsd && !mips64)
+
 package unix
 
 import (

src/internal/syscall/unix/getentropy_openbsd.go

@@ -1,25 +1,17 @@
-// Copyright 2016 The Go Authors. All rights reserved.
+// Copyright 2022 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build openbsd && !mips64
+
 package unix
 
-import (
-	"syscall"
-	"unsafe"
-)
-
-// getentropy(2)'s syscall number, from /usr/src/sys/kern/syscalls.master
-const entropyTrap uintptr = 7
+import _ "unsafe" // for linkname
 
 // GetEntropy calls the OpenBSD getentropy system call.
 func GetEntropy(p []byte) error {
-	_, _, errno := syscall.Syscall(entropyTrap,
-		uintptr(unsafe.Pointer(&p[0])),
-		uintptr(len(p)),
-		0)
-	if errno != 0 {
-		return errno
-	}
-	return nil
+	return getentropy(p)
 }
+
+//go:linkname getentropy syscall.getentropy
+func getentropy(p []byte) error

src/internal/syscall/unix/getentropy_openbsd_mips64.go

@@ -0,0 +1,25 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// getentropy(2)'s syscall number, from /usr/src/sys/kern/syscalls.master
+const entropyTrap uintptr = 7
+
+// GetEntropy calls the OpenBSD getentropy system call.
+func GetEntropy(p []byte) error {
+	_, _, errno := syscall.Syscall(entropyTrap,
+		uintptr(unsafe.Pointer(&p[0])),
+		uintptr(len(p)),
+		0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}

src/internal/syscall/unix/nonblocking.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build dragonfly || freebsd || linux || netbsd || openbsd
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
 
 package unix
 

src/internal/syscall/unix/nonblocking_libc.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build aix || darwin || solaris
+//go:build aix || darwin || (openbsd && !mips64) || solaris
 
 package unix
 

src/net/fcntl_libc_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build aix || darwin || solaris
+//go:build aix || darwin || (openbsd && !mips64) || solaris
 
 package net
 

src/net/fcntl_syscall_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build dragonfly || freebsd || linux || netbsd || openbsd
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
 
 package net
 

src/runtime/export_openbsd_test.go

@@ -0,0 +1,15 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build openbsd && !mips64
+
+package runtime
+
+func Fcntl(fd, cmd, arg uintptr) (uintptr, uintptr) {
+	r := fcntl(int32(fd), int32(cmd), int32(arg))
+	if r < 0 {
+		return ^uintptr(0), uintptr(-r)
+	}
+	return uintptr(r), 0
+}

src/runtime/nbpipe_fcntl_libc_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build aix || darwin || solaris
+//go:build aix || darwin || (openbsd && !mips64) || solaris
 
 package runtime_test
 

src/runtime/nbpipe_fcntl_unix_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build dragonfly || freebsd || linux || netbsd || openbsd
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
 
 package runtime_test