1 files changed, 151 insertions, 0 deletions
diff --git a/test/syscalls/linux/msync.cc b/test/syscalls/linux/msync.cc
new file mode 100644
index 000000000..2b2b6aef9
--- /dev/null
+++ b/test/syscalls/linux/msync.cc
@@ -0,0 +1,151 @@
+// Copyright 2018 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.
+
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <functional>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "test/util/file_descriptor.h"
+#include "test/util/memory_util.h"
+#include "test/util/posix_error.h"
+#include "test/util/temp_path.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+// Parameters for msync tests. Use a std::tuple so we can use
+// ::testing::Combine.
+using MsyncTestParam =
+    std::tuple<int,                                    // msync flags
+               std::function<PosixErrorOr<Mapping>()>  // returns mapping to
+                                                       // msync
+               >;
+
+class MsyncParameterizedTest : public ::testing::TestWithParam<MsyncTestParam> {
+ protected:
+  int msync_flags() const { return std::get<0>(GetParam()); }
+
+  PosixErrorOr<Mapping> GetMapping() const { return std::get<1>(GetParam())(); }
+};
+
+// All valid msync(2) flag combinations, not including MS_INVALIDATE. ("Linux
+// permits a call to msync() that specifies neither [MS_SYNC or MS_ASYNC], with
+// semantics that are (currently) equivalent to specifying MS_ASYNC." -
+// msync(2))
+constexpr std::initializer_list<int> kMsyncFlags = {MS_SYNC, MS_ASYNC, 0};
+
+// Returns functions that return mappings that should be successfully
+// msync()able.
+std::vector<std::function<PosixErrorOr<Mapping>()>> SyncableMappings() {
+  std::vector<std::function<PosixErrorOr<Mapping>()>> funcs;
+  for (bool const writable : {false, true}) {
+    for (int const mflags : {MAP_PRIVATE, MAP_SHARED}) {
+      int const prot = PROT_READ | (writable ? PROT_WRITE : 0);
+      int const oflags = O_CREAT | (writable ? O_RDWR : O_RDONLY);
+      funcs.push_back([=] { return MmapAnon(kPageSize, prot, mflags); });
+      funcs.push_back([=]() -> PosixErrorOr<Mapping> {
+        std::string const path = NewTempAbsPath();
+        ASSIGN_OR_RETURN_ERRNO(auto fd, Open(path, oflags, 0644));
+        // Don't unlink the file since that breaks save/restore. Just let the
+        // test infrastructure clean up all of our temporary files when we're
+        // done.
+        return Mmap(nullptr, kPageSize, prot, mflags, fd.get(), 0);
+      });
+    }
+  }
+  return funcs;
+}
+
+PosixErrorOr<Mapping> NoMappings() {
+  return PosixError(EINVAL, "unexpected attempt to create a mapping");
+}
+
+// "Fixture" for msync tests that hold for all valid flags, but do not create
+// mappings.
+using MsyncNoMappingTest = MsyncParameterizedTest;
+
+TEST_P(MsyncNoMappingTest, UnmappedAddressWithZeroLengthSucceeds) {
+  EXPECT_THAT(msync(nullptr, 0, msync_flags()), SyscallSucceeds());
+}
+
+TEST_P(MsyncNoMappingTest, UnmappedAddressWithNonzeroLengthFails) {
+  EXPECT_THAT(msync(nullptr, kPageSize, msync_flags()),
+              SyscallFailsWithErrno(ENOMEM));
+}
+
+INSTANTIATE_TEST_SUITE_P(All, MsyncNoMappingTest,
+                         ::testing::Combine(::testing::ValuesIn(kMsyncFlags),
+                                            ::testing::Values(NoMappings)));
+
+// "Fixture" for msync tests that are not parameterized by msync flags, but do
+// create mappings.
+using MsyncNoFlagsTest = MsyncParameterizedTest;
+
+TEST_P(MsyncNoFlagsTest, BothSyncAndAsyncFails) {
+  auto m = ASSERT_NO_ERRNO_AND_VALUE(GetMapping());
+  EXPECT_THAT(msync(m.ptr(), m.len(), MS_SYNC | MS_ASYNC),
+              SyscallFailsWithErrno(EINVAL));
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    All, MsyncNoFlagsTest,
+    ::testing::Combine(::testing::Values(0),  // ignored
+                       ::testing::ValuesIn(SyncableMappings())));
+
+// "Fixture" for msync tests parameterized by both msync flags and sources of
+// mappings.
+using MsyncFullParamTest = MsyncParameterizedTest;
+
+TEST_P(MsyncFullParamTest, NormallySucceeds) {
+  auto m = ASSERT_NO_ERRNO_AND_VALUE(GetMapping());
+  EXPECT_THAT(msync(m.ptr(), m.len(), msync_flags()), SyscallSucceeds());
+}
+
+TEST_P(MsyncFullParamTest, UnalignedLengthSucceeds) {
+  auto m = ASSERT_NO_ERRNO_AND_VALUE(GetMapping());
+  EXPECT_THAT(msync(m.ptr(), m.len() - 1, msync_flags()), SyscallSucceeds());
+}
+
+TEST_P(MsyncFullParamTest, UnalignedAddressFails) {
+  auto m = ASSERT_NO_ERRNO_AND_VALUE(GetMapping());
+  EXPECT_THAT(
+      msync(reinterpret_cast<void*>(m.addr() + 1), m.len() - 1, msync_flags()),
+      SyscallFailsWithErrno(EINVAL));
+}
+
+TEST_P(MsyncFullParamTest, InvalidateUnlockedSucceeds) {
+  auto m = ASSERT_NO_ERRNO_AND_VALUE(GetMapping());
+  EXPECT_THAT(msync(m.ptr(), m.len(), msync_flags() | MS_INVALIDATE),
+              SyscallSucceeds());
+}
+
+// The test for MS_INVALIDATE on mlocked pages is in mlock.cc since it requires
+// probing for mlock support.
+
+INSTANTIATE_TEST_SUITE_P(
+    All, MsyncFullParamTest,
+    ::testing::Combine(::testing::ValuesIn(kMsyncFlags),
+                       ::testing::ValuesIn(SyncableMappings())));
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor