Open source system call tests.

PiperOrigin-RevId: 224886231
Change-Id: I0fccb4d994601739d8b16b1d4e6b31f40297fb22

1 files changed, 172 insertions, 0 deletions

diff --git a/test/syscalls/linux/rtsignal.cc b/test/syscalls/linux/rtsignal.cc
new file mode 100644
index 000000000..1f2fed7cc
--- /dev/null
+++ b/test/syscalls/linux/rtsignal.cc
@@ -0,0 +1,172 @@
+// 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 <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <cerrno>
+#include <csignal>
+
+#include "gtest/gtest.h"
+#include "test/util/cleanup.h"
+#include "test/util/logging.h"
+#include "test/util/posix_error.h"
+#include "test/util/signal_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+// saved_info is set by the handler.
+siginfo_t saved_info;
+
+// has_saved_info is set to true by the handler.
+volatile bool has_saved_info;
+
+void SigHandler(int sig, siginfo_t* info, void* context) {
+  // Copy to the given info.
+  saved_info = *info;
+  has_saved_info = true;
+}
+
+void ClearSavedInfo() {
+  // Clear the cached info.
+  memset(&saved_info, 0, sizeof(saved_info));
+  has_saved_info = false;
+}
+
+PosixErrorOr<Cleanup> SetupSignalHandler(int sig) {
+  struct sigaction sa;
+  sa.sa_sigaction = SigHandler;
+  sigfillset(&sa.sa_mask);
+  sa.sa_flags = SA_SIGINFO;
+  return ScopedSigaction(sig, sa);
+}
+
+class RtSignalTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    action_cleanup_ = ASSERT_NO_ERRNO_AND_VALUE(SetupSignalHandler(SIGUSR1));
+    mask_cleanup_ =
+        ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGUSR1));
+  }
+
+  void TearDown() override { ClearSavedInfo(); }
+
+ private:
+  Cleanup action_cleanup_;
+  Cleanup mask_cleanup_;
+};
+
+static int rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t* uinfo) {
+  int ret;
+  do {
+    // NOTE: rt_sigqueueinfo(2) could return EAGAIN for RT signals.
+    ret = syscall(SYS_rt_sigqueueinfo, tgid, sig, uinfo);
+  } while (ret == -1 && errno == EAGAIN);
+  return ret;
+}
+
+TEST_F(RtSignalTest, InvalidTID) {
+  siginfo_t uinfo;
+  // Depending on the kernel version, these calls may fail with
+  // ESRCH (goobunutu machines) or EPERM (production machines). Thus,
+  // the test simply ensures that they do fail.
+  EXPECT_THAT(rt_sigqueueinfo(-1, SIGUSR1, &uinfo), SyscallFails());
+  EXPECT_FALSE(has_saved_info);
+  EXPECT_THAT(rt_sigqueueinfo(0, SIGUSR1, &uinfo), SyscallFails());
+  EXPECT_FALSE(has_saved_info);
+}
+
+TEST_F(RtSignalTest, InvalidCodes) {
+  siginfo_t uinfo;
+
+  // We need a child for the code checks to apply. If the process is delivering
+  // to itself, then it can use whatever codes it wants and they will go
+  // through.
+  pid_t child = fork();
+  if (child == 0) {
+    _exit(1);
+  }
+  ASSERT_THAT(child, SyscallSucceeds());
+
+  // These are not allowed for child processes.
+  uinfo.si_code = 0;  // SI_USER.
+  EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo),
+              SyscallFailsWithErrno(EPERM));
+  uinfo.si_code = 0x80;  // SI_KERNEL.
+  EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo),
+              SyscallFailsWithErrno(EPERM));
+  uinfo.si_code = -6;  // SI_TKILL.
+  EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo),
+              SyscallFailsWithErrno(EPERM));
+  uinfo.si_code = -1;  // SI_QUEUE (allowed).
+  EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo), SyscallSucceeds());
+
+  // Join the child process.
+  EXPECT_THAT(waitpid(child, nullptr, 0), SyscallSucceeds());
+}
+
+TEST_F(RtSignalTest, ValueDelivered) {
+  siginfo_t uinfo;
+  uinfo.si_code = -1;  // SI_QUEUE (allowed).
+  uinfo.si_errno = 0x1234;
+
+  EXPECT_EQ(saved_info.si_errno, 0x0);
+  EXPECT_THAT(rt_sigqueueinfo(getpid(), SIGUSR1, &uinfo), SyscallSucceeds());
+  EXPECT_TRUE(has_saved_info);
+  EXPECT_EQ(saved_info.si_errno, 0x1234);
+}
+
+TEST_F(RtSignalTest, SignoMatch) {
+  auto action2_cleanup = ASSERT_NO_ERRNO_AND_VALUE(SetupSignalHandler(SIGUSR2));
+  auto mask2_cleanup =
+      ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGUSR2));
+
+  siginfo_t uinfo;
+  uinfo.si_code = -1;  // SI_QUEUE (allowed).
+
+  EXPECT_THAT(rt_sigqueueinfo(getpid(), SIGUSR1, &uinfo), SyscallSucceeds());
+  EXPECT_TRUE(has_saved_info);
+  EXPECT_EQ(saved_info.si_signo, SIGUSR1);
+
+  ClearSavedInfo();
+
+  EXPECT_THAT(rt_sigqueueinfo(getpid(), SIGUSR2, &uinfo), SyscallSucceeds());
+  EXPECT_TRUE(has_saved_info);
+  EXPECT_EQ(saved_info.si_signo, SIGUSR2);
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
+
+int main(int argc, char** argv) {
+  // These tests depend on delivering SIGUSR1/2 to the main thread (so they can
+  // synchronously check has_saved_info). Block these so that any other threads
+  // created by TestInit will also have them blocked.
+  sigset_t set;
+  sigemptyset(&set);
+  sigaddset(&set, SIGUSR1);
+  sigaddset(&set, SIGUSR2);
+  TEST_PCHECK(sigprocmask(SIG_BLOCK, &set, nullptr) == 0);
+
+  gvisor::testing::TestInit(&argc, &argv);
+
+  return RUN_ALL_TESTS();
+}