1 files changed, 88 insertions, 0 deletions
diff --git a/test/syscalls/linux/pause.cc b/test/syscalls/linux/pause.cc
new file mode 100644
index 000000000..4e1148c24
--- /dev/null
+++ b/test/syscalls/linux/pause.cc
@@ -0,0 +1,88 @@
+// 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 <errno.h>
+#include <signal.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <atomic>
+
+#include "gtest/gtest.h"
+#include "absl/synchronization/mutex.h"
+#include "absl/time/clock.h"
+#include "absl/time/time.h"
+#include "test/util/signal_util.h"
+#include "test/util/test_util.h"
+#include "test/util/thread_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+void NoopSignalHandler(int sig, siginfo_t* info, void* context) {}
+
+}  // namespace
+
+TEST(PauseTest, OnlyReturnsWhenSignalHandled) {
+  struct sigaction sa;
+  sigfillset(&sa.sa_mask);
+
+  // Ensure that SIGUSR1 is ignored.
+  sa.sa_handler = SIG_IGN;
+  ASSERT_THAT(sigaction(SIGUSR1, &sa, nullptr), SyscallSucceeds());
+
+  // Register a handler for SIGUSR2.
+  sa.sa_sigaction = NoopSignalHandler;
+  sa.sa_flags = SA_SIGINFO;
+  ASSERT_THAT(sigaction(SIGUSR2, &sa, nullptr), SyscallSucceeds());
+
+  // The child sets their own tid.
+  absl::Mutex mu;
+  pid_t child_tid = 0;
+  bool child_tid_available = false;
+  std::atomic<int> sent_signal{0};
+  std::atomic<int> waking_signal{0};
+  ScopedThread t([&] {
+    mu.Lock();
+    child_tid = gettid();
+    child_tid_available = true;
+    mu.Unlock();
+    EXPECT_THAT(pause(), SyscallFailsWithErrno(EINTR));
+    waking_signal.store(sent_signal.load());
+  });
+  mu.Lock();
+  mu.Await(absl::Condition(&child_tid_available));
+  mu.Unlock();
+
+  // Wait a bit to let the child enter pause().
+  absl::SleepFor(absl::Seconds(3));
+
+  // The child should not be woken by SIGUSR1.
+  sent_signal.store(SIGUSR1);
+  ASSERT_THAT(tgkill(getpid(), child_tid, SIGUSR1), SyscallSucceeds());
+  absl::SleepFor(absl::Seconds(3));
+
+  // The child should be woken by SIGUSR2.
+  sent_signal.store(SIGUSR2);
+  ASSERT_THAT(tgkill(getpid(), child_tid, SIGUSR2), SyscallSucceeds());
+  absl::SleepFor(absl::Seconds(3));
+
+  EXPECT_EQ(SIGUSR2, waking_signal.load());
+}
+
+}  // namespace testing
+}  // namespace gvisor