1 files changed, 48 insertions, 0 deletions
diff --git a/test/syscalls/linux/vdso.cc b/test/syscalls/linux/vdso.cc
new file mode 100644
index 000000000..0f6e1c7c6
--- /dev/null
+++ b/test/syscalls/linux/vdso.cc
@@ -0,0 +1,48 @@
+// Copyright 2018 Google LLC
+//
+// 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.
+
+#include <string.h>
+#include <sys/mman.h>
+
+#include <algorithm>
+
+#include "gtest/gtest.h"
+#include "test/util/fs_util.h"
+#include "test/util/posix_error.h"
+#include "test/util/proc_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+// Ensure that the vvar page cannot be made writable.
+TEST(VvarTest, WriteVvar) {
+  auto contents = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps"));
+  auto maps = ASSERT_NO_ERRNO_AND_VALUE(ParseProcMaps(contents));
+  auto it = std::find_if(maps.begin(), maps.end(), [](const ProcMapsEntry& e) {
+    return e.filename == "[vvar]";
+  });
+
+  SKIP_IF(it == maps.end());
+  EXPECT_THAT(mprotect(reinterpret_cast<void*>(it->start), kPageSize,
+                       PROT_READ | PROT_WRITE),
+              SyscallFailsWithErrno(EACCES));
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor