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// 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 <signal.h>
#include <unistd.h>
#include "gtest/gtest.h"
#include "absl/time/clock.h"
#include "absl/time/time.h"
#include "test/util/file_descriptor.h"
#include "test/util/logging.h"
#include "test/util/signal_util.h"
#include "test/util/test_util.h"
#include "test/util/thread_util.h"
namespace gvisor {
namespace testing {
namespace {
// N.B. Below, main blocks SIGALRM. Test cases must unblock it if they want
// delivery.
void do_nothing_handler(int sig, siginfo_t* siginfo, void* arg) {}
// No random save as the test relies on alarm timing. Cooperative save tests
// already cover the save between alarm and read.
TEST(AlarmTest, Interrupt_NoRandomSave) {
int pipe_fds[2];
ASSERT_THAT(pipe(pipe_fds), SyscallSucceeds());
FileDescriptor read_fd(pipe_fds[0]);
FileDescriptor write_fd(pipe_fds[1]);
// Use a signal handler that interrupts but does nothing rather than using the
// default terminate action.
struct sigaction sa;
sa.sa_sigaction = do_nothing_handler;
sigfillset(&sa.sa_mask);
sa.sa_flags = 0;
auto sa_cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGALRM, sa));
// Actually allow SIGALRM delivery.
auto mask_cleanup =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGALRM));
// Alarm in 20 second, which should be well after read blocks below.
ASSERT_THAT(alarm(20), SyscallSucceeds());
char buf;
ASSERT_THAT(read(read_fd.get(), &buf, 1), SyscallFailsWithErrno(EINTR));
}
/* Count of the number of SIGALARMS handled. */
static volatile int alarms_received = 0;
void inc_alarms_handler(int sig, siginfo_t* siginfo, void* arg) {
alarms_received++;
}
// No random save as the test relies on alarm timing. Cooperative save tests
// already cover the save between alarm and read.
TEST(AlarmTest, Restart_NoRandomSave) {
alarms_received = 0;
int pipe_fds[2];
ASSERT_THAT(pipe(pipe_fds), SyscallSucceeds());
FileDescriptor read_fd(pipe_fds[0]);
// Write end closed by thread below.
struct sigaction sa;
sa.sa_sigaction = inc_alarms_handler;
sigfillset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
auto sa_cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGALRM, sa));
// Spawn a thread to eventually unblock the read below.
ScopedThread t([pipe_fds] {
absl::SleepFor(absl::Seconds(30));
EXPECT_THAT(close(pipe_fds[1]), SyscallSucceeds());
});
// Actually allow SIGALRM delivery.
auto mask_cleanup =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGALRM));
// Alarm in 20 second, which should be well after read blocks below, but
// before it returns.
ASSERT_THAT(alarm(20), SyscallSucceeds());
// Read and eventually get an EOF from the writer closing. If SA_RESTART
// didn't work, then the alarm would not have fired and we wouldn't increment
// our alarms_received count in our signal handler, or we would have not
// restarted the syscall gracefully, which we expect below in order to be
// able to get the final EOF on the pipe.
char buf;
ASSERT_THAT(read(read_fd.get(), &buf, 1), SyscallSucceeds());
EXPECT_EQ(alarms_received, 1);
t.Join();
}
// No random save as the test relies on alarm timing. Cooperative save tests
// already cover the save between alarm and pause.
TEST(AlarmTest, SaSiginfo_NoRandomSave) {
// Use a signal handler that interrupts but does nothing rather than using the
// default terminate action.
struct sigaction sa;
sa.sa_sigaction = do_nothing_handler;
sigfillset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
auto sa_cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGALRM, sa));
// Actually allow SIGALRM delivery.
auto mask_cleanup =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGALRM));
// Alarm in 20 second, which should be well after pause blocks below.
ASSERT_THAT(alarm(20), SyscallSucceeds());
ASSERT_THAT(pause(), SyscallFailsWithErrno(EINTR));
}
// No random save as the test relies on alarm timing. Cooperative save tests
// already cover the save between alarm and pause.
TEST(AlarmTest, SaInterrupt_NoRandomSave) {
// Use a signal handler that interrupts but does nothing rather than using the
// default terminate action.
struct sigaction sa;
sa.sa_sigaction = do_nothing_handler;
sigfillset(&sa.sa_mask);
sa.sa_flags = SA_INTERRUPT;
auto sa_cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGALRM, sa));
// Actually allow SIGALRM delivery.
auto mask_cleanup =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGALRM));
// Alarm in 20 second, which should be well after pause blocks below.
ASSERT_THAT(alarm(20), SyscallSucceeds());
ASSERT_THAT(pause(), SyscallFailsWithErrno(EINTR));
}
TEST(AlarmTest, UserModeSpinning) {
alarms_received = 0;
struct sigaction sa = {};
sa.sa_sigaction = inc_alarms_handler;
sigfillset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
auto sa_cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGALRM, sa));
// Actually allow SIGALRM delivery.
auto mask_cleanup =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGALRM));
// Alarm in 20 second, which should be well into the loop below.
ASSERT_THAT(alarm(20), SyscallSucceeds());
// Make sure that the signal gets delivered even if we are spinning in user
// mode when it arrives.
while (!alarms_received) {
}
}
} // namespace
} // namespace testing
} // namespace gvisor
int main(int argc, char** argv) {
// These tests depend on delivering SIGALRM to the main thread. Block SIGALRM
// so that any other threads created by TestInit will also have SIGALRM
// blocked.
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGALRM);
TEST_PCHECK(sigprocmask(SIG_BLOCK, &set, nullptr) == 0);
gvisor::testing::TestInit(&argc, &argv);
return gvisor::testing::RunAllTests();
}
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