unix: fix MmapPtr test failing on OpenBSD

OpenBSD apparently doesn't allow unmapping address space if part of the region is already unmapped. This tweaks the test so that munmapping twice no longer happens. Fixes golang/go#68181 Change-Id: I588255f5e10ec015dbb7188eac79cee6be570680 GitHub-Last-Rev: 2535abd GitHub-Pull-Request: #199 Cq-Include-Trybots: luci.golang.try:go1.22-openbsd-amd64 Reviewed-on: https://go-review.googlesource.com/c/sys/+/595095 TryBot-Bypass: Ian Lance Taylor <[email protected]> Reviewed-by: Dmitri Shuralyov <[email protected]> Reviewed-by: Ian Lance Taylor <[email protected]> Auto-Submit: Ian Lance Taylor <[email protected]>
golang · Jun 26, 2024 · c892bb7 · c892bb7
1 parent a0ef40a
commit c892bb7
Showing 1 changed file with 8 additions and 12 deletions.
diff --git a/unix/mmap_unix_test.go b/unix/mmap_unix_test.go
@@ -9,7 +9,6 @@ package unix_test
 import (
 	"runtime"
 	"testing"
-	"unsafe"
 
 	"golang.org/x/sys/unix"
 )
@@ -52,23 +51,20 @@ func TestMmap(t *testing.T) {
 }
 
 func TestMmapPtr(t *testing.T) {
-	mmapProt := unix.PROT_NONE
-	mmapPtrProt := unix.PROT_READ | unix.PROT_WRITE
-	b, err := unix.Mmap(-1, 0, 2*unix.Getpagesize(), mmapProt, unix.MAP_ANON|unix.MAP_PRIVATE)
+	p, err := unix.MmapPtr(-1, 0, nil, uintptr(2*unix.Getpagesize()),
+		unix.PROT_NONE, unix.MAP_ANON|unix.MAP_PRIVATE)
 	if err != nil {
-		t.Fatalf("Mmap: %v", err)
+		t.Fatalf("MmapPtr: %v", err)
 	}
-	if _, err := unix.MmapPtr(-1, 0, unsafe.Pointer(&b[0]), uintptr(unix.Getpagesize()),
-		mmapPtrProt, unix.MAP_ANON|unix.MAP_PRIVATE|unix.MAP_FIXED); err != nil {
+
+	if _, err := unix.MmapPtr(-1, 0, p, uintptr(unix.Getpagesize()),
+		unix.PROT_READ|unix.PROT_WRITE, unix.MAP_ANON|unix.MAP_PRIVATE|unix.MAP_FIXED); err != nil {
 		t.Fatalf("MmapPtr: %v", err)
 	}
 
-	b[0] = 42
+	*(*byte)(p) = 42
 
-	if err := unix.MunmapPtr(unsafe.Pointer(&b[0]), uintptr(unix.Getpagesize())); err != nil {
+	if err := unix.MunmapPtr(p, uintptr(2*unix.Getpagesize())); err != nil {
 		t.Fatalf("MunmapPtr: %v", err)
 	}
-	if err := unix.Munmap(b); err != nil {
-		t.Fatalf("Munmap: %v", err)
-	}
 }