unix: add support for zos/s390x

This adds sys/unix support for zos/s390x. These changes should not affect other platforms. Fixes golang/go#43230 Change-Id: If1c1d9df134fbc44f95ca1b214e836508696da93 Reviewed-on: https://go-review.googlesource.com/c/sys/+/275992 Trust: Emmanuel Odeke <emmanuel@orijtech.com> Trust: Tobias Klauser <tobias.klauser@gmail.com> Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com> Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2026-09-05 08:37:31 -04:00 · 2021-02-24 23:11:01 +00:00
parent eede4237b3
commit 5640770f5e
23 changed files with 8937 additions and 16 deletions
@@ -0,0 +1,87 @@
+// Copyright 2020 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 zos && s390x
+// +build zos,s390x
+
+// This test is based on mmap_unix_test, but tweaked for z/OS, which does not support memadvise
+// or anonymous mmapping.
+
+package unix_test
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"golang.org/x/sys/unix"
+)
+
+func TestMmap(t *testing.T) {
+	tmpdir := mktmpdir(t)
+	filename := filepath.Join(filepath.Join(tmpdir, "testdata"), "memmapped_file")
+	destination, err := os.Create(filename)
+	if err != nil {
+		t.Fatal("os.Create:", err)
+		return
+	}
+	defer os.RemoveAll(tmpdir)
+
+	fmt.Fprintf(destination, "%s\n", "0 <- Flipped between 0 and 1 when test runs successfully")
+	fmt.Fprintf(destination, "%s\n", "//Do not change contents - mmap test relies on this")
+	destination.Close()
+	fd, err := unix.Open(filename, unix.O_RDWR, 0o777)
+	if err != nil {
+		t.Fatalf("Open: %v", err)
+	}
+
+	b, err := unix.Mmap(fd, 0, 8, unix.PROT_READ, unix.MAP_SHARED)
+	if err != nil {
+		t.Fatalf("Mmap: %v", err)
+	}
+
+	if err := unix.Mprotect(b, unix.PROT_READ|unix.PROT_WRITE); err != nil {
+		t.Fatalf("Mprotect: %v", err)
+	}
+
+	// Flip flag in test file via mapped memory
+	flagWasZero := true
+	if b[0] == '0' {
+		b[0] = '1'
+	} else if b[0] == '1' {
+		b[0] = '0'
+		flagWasZero = false
+	}
+
+	if err := unix.Msync(b, unix.MS_SYNC); err != nil {
+		t.Fatalf("Msync: %v", err)
+	}
+
+	// Read file from FS to ensure flag flipped after msync
+	buf, err := ioutil.ReadFile(filename)
+	if err != nil {
+		t.Fatalf("Could not read mmapped file from disc for test: %v", err)
+	}
+	if flagWasZero && buf[0] != '1' || !flagWasZero && buf[0] != '0' {
+		t.Error("Flag flip in MAP_SHARED mmapped file not visible")
+	}
+
+	if err := unix.Munmap(b); err != nil {
+		t.Fatalf("Munmap: %v", err)
+	}
+}
+
+func mktmpdir(t *testing.T) string {
+	tmpdir, err := ioutil.TempDir("", "memmapped_file")
+	if err != nil {
+		t.Fatal("mktmpdir:", err)
+	}
+	if err := os.Mkdir(filepath.Join(tmpdir, "testdata"), 0700); err != nil {
+		os.RemoveAll(tmpdir)
+		t.Fatal("mktmpdir:", err)
+	}
+	return tmpdir
+}