Prepare for supporting cross compilation.

PiperOrigin-RevId: 346496532

3 files changed, 29 insertions, 1 deletions

diff --git a/pkg/flipcall/BUILD b/pkg/flipcall/BUILD
index aa8e4e1f3..cc31d0175 100644
--- a/pkg/flipcall/BUILD
+++ b/pkg/flipcall/BUILD
@@ -11,7 +11,8 @@ go_library(
         "futex_linux.go",
         "io.go",
         "packet_window_allocator.go",
-        "packet_window_mmap.go",
+        "packet_window_mmap_amd64.go",
+        "packet_window_mmap_arm64.go",
     ],
     visibility = ["//visibility:public"],
     deps = [
diff --git a/pkg/flipcall/packet_window_mmap.go b/pkg/flipcall/packet_window_mmap_amd64.go
index 869183b11..869183b11 100644
--- a/pkg/flipcall/packet_window_mmap.go
+++ b/pkg/flipcall/packet_window_mmap_amd64.go
diff --git a/pkg/flipcall/packet_window_mmap_arm64.go b/pkg/flipcall/packet_window_mmap_arm64.go
new file mode 100644
index 000000000..b9c9c44f6
--- /dev/null
+++ b/pkg/flipcall/packet_window_mmap_arm64.go
@@ -0,0 +1,27 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build arm64
+
+package flipcall
+
+import (
+	"syscall"
+)
+
+// Return a memory mapping of the pwd in memory that can be shared outside the sandbox.
+func packetWindowMmap(pwd PacketWindowDescriptor) (uintptr, syscall.Errno) {
+	m, _, err := syscall.RawSyscall6(syscall.SYS_MMAP, 0, uintptr(pwd.Length), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED, uintptr(pwd.FD), uintptr(pwd.Offset))
+	return m, err
+}