runtime: enable runtime_mmap_test.go on AIX

AIX doesn't allow to mmap an address range which is already mmap.
Therefore, once the region has been allocated, it must munmap before
being able to play with it.

Change-Id: I1547782f0379024f57869f1dda8c1c9bb12d831f
Reviewed-on: https://go-review.googlesource.com/c/go/+/174059Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/runtime/defs_aix.go

@@ -65,7 +65,7 @@ const (
 	_PROT_WRITE = C.PROT_WRITE
 	_PROT_EXEC  = C.PROT_EXEC
 
-	_MAP_ANONYMOUS = C.MAP_ANONYMOUS
+	_MAP_ANON      = C.MAP_ANONYMOUS
 	_MAP_PRIVATE   = C.MAP_PRIVATE
 	_MAP_FIXED     = C.MAP_FIXED
 	_MADV_DONTNEED = C.MADV_DONTNEED

src/runtime/defs_aix_ppc64.go

@@ -22,7 +22,7 @@ const (
 	_PROT_WRITE = 0x2
 	_PROT_EXEC  = 0x4
 
-	_MAP_ANONYMOUS = 0x10
+	_MAP_ANON      = 0x10
 	_MAP_PRIVATE   = 0x2
 	_MAP_FIXED     = 0x100
 	_MADV_DONTNEED = 0x4

src/runtime/export_mmap_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.
 
-// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd linux nacl netbsd openbsd solaris
 
 // Export guts for testing.
 

src/runtime/mem_aix.go

@@ -12,7 +12,7 @@ import (
 // prevents us from allocating more stack.
 //go:nosplit
 func sysAlloc(n uintptr, sysStat *uint64) unsafe.Pointer {
-	p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANONYMOUS|_MAP_PRIVATE, -1, 0)
+	p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
 	if err != 0 {
 		if err == _EACCES {
 			print("runtime: mmap: access denied\n")
@@ -46,11 +46,11 @@ func sysFree(v unsafe.Pointer, n uintptr, sysStat *uint64) {
 }
 
 func sysFault(v unsafe.Pointer, n uintptr) {
-	mmap(v, n, _PROT_NONE, _MAP_ANONYMOUS|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
+	mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
 }
 
 func sysReserve(v unsafe.Pointer, n uintptr) unsafe.Pointer {
-	p, err := mmap(v, n, _PROT_NONE, _MAP_ANONYMOUS|_MAP_PRIVATE, -1, 0)
+	p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
 	if err != 0 {
 		return nil
 	}
@@ -63,7 +63,7 @@ func sysMap(v unsafe.Pointer, n uintptr, sysStat *uint64) {
 	// AIX does not allow mapping a range that is already mapped.
 	// So always unmap first even if it is already unmapped.
 	munmap(v, n)
-	p, err := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANONYMOUS|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
+	p, err := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
 
 	if err == _ENOMEM {
 		throw("runtime: out of memory")

src/runtime/runtime_mmap_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.
 
-// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd linux nacl netbsd openbsd solaris
 
 package runtime_test
 
@@ -34,6 +34,11 @@ func TestPhysPageSize(t *testing.T) {
 		t.Fatalf("Mmap: %v", err)
 	}
 
+	if runtime.GOOS == "aix" {
+		// AIX does not allow mapping a range that is already mapped.
+		runtime.Munmap(unsafe.Pointer(uintptr(b)), 2*ps)
+	}
+
 	// Mmap should fail at a half page into the buffer.
 	_, err = runtime.Mmap(unsafe.Pointer(uintptr(b)+ps/2), ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE|runtime.MAP_FIXED, -1, 0)
 	if err == 0 {