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-rw-r--r--test/syscalls/linux/sigstop.cc200
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diff --git a/test/syscalls/linux/sigstop.cc b/test/syscalls/linux/sigstop.cc
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--- a/test/syscalls/linux/sigstop.cc
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@@ -1,200 +0,0 @@
-// 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 <stdlib.h>
-#include <sys/select.h>
-
-#include "gtest/gtest.h"
-#include "absl/flags/flag.h"
-#include "absl/time/clock.h"
-#include "absl/time/time.h"
-#include "test/util/multiprocess_util.h"
-#include "test/util/posix_error.h"
-#include "test/util/test_util.h"
-#include "test/util/thread_util.h"
-
-ABSL_FLAG(bool, sigstop_test_child, false,
- "If true, run the SigstopTest child workload.");
-
-namespace gvisor {
-namespace testing {
-
-namespace {
-
-constexpr absl::Duration kChildStartupDelay = absl::Seconds(5);
-constexpr absl::Duration kChildMainThreadDelay = absl::Seconds(10);
-constexpr absl::Duration kChildExtraThreadDelay = absl::Seconds(15);
-constexpr absl::Duration kPostSIGSTOPDelay = absl::Seconds(20);
-
-// Comparisons on absl::Duration aren't yet constexpr (2017-07-14), so we
-// can't just use static_assert.
-TEST(SigstopTest, TimesAreRelativelyConsistent) {
- EXPECT_LT(kChildStartupDelay, kChildMainThreadDelay)
- << "Child process will exit before the parent process attempts to stop "
- "it";
- EXPECT_LT(kChildMainThreadDelay, kChildExtraThreadDelay)
- << "Secondary thread in child process will exit before main thread, "
- "causing it to exit with the wrong code";
- EXPECT_LT(kChildExtraThreadDelay, kPostSIGSTOPDelay)
- << "Parent process stops waiting before child process may exit if "
- "improperly stopped, rendering the test ineffective";
-}
-
-// Exit codes communicated from the child workload to the parent test process.
-constexpr int kChildMainThreadExitCode = 10;
-constexpr int kChildExtraThreadExitCode = 11;
-
-TEST(SigstopTest, Correctness) {
- pid_t child_pid = -1;
- int execve_errno = 0;
- auto cleanup = ASSERT_NO_ERRNO_AND_VALUE(
- ForkAndExec("/proc/self/exe", {"/proc/self/exe", "--sigstop_test_child"},
- {}, nullptr, &child_pid, &execve_errno));
-
- ASSERT_GT(child_pid, 0);
- ASSERT_EQ(execve_errno, 0);
-
- // Wait for the child subprocess to start the second thread before stopping
- // it.
- absl::SleepFor(kChildStartupDelay);
- ASSERT_THAT(kill(child_pid, SIGSTOP), SyscallSucceeds());
- int status;
- EXPECT_THAT(RetryEINTR(waitpid)(child_pid, &status, WUNTRACED),
- SyscallSucceedsWithValue(child_pid));
- EXPECT_TRUE(WIFSTOPPED(status));
- EXPECT_EQ(SIGSTOP, WSTOPSIG(status));
-
- // Sleep for longer than either of the sleeps in the child subprocess,
- // expecting the child to stay alive because it's stopped.
- absl::SleepFor(kPostSIGSTOPDelay);
- ASSERT_THAT(RetryEINTR(waitpid)(child_pid, &status, WNOHANG),
- SyscallSucceedsWithValue(0));
-
- // Resume the child.
- ASSERT_THAT(kill(child_pid, SIGCONT), SyscallSucceeds());
-
- EXPECT_THAT(RetryEINTR(waitpid)(child_pid, &status, WCONTINUED),
- SyscallSucceedsWithValue(child_pid));
- EXPECT_TRUE(WIFCONTINUED(status));
-
- // Expect it to die.
- ASSERT_THAT(RetryEINTR(waitpid)(child_pid, &status, 0), SyscallSucceeds());
- ASSERT_TRUE(WIFEXITED(status));
- ASSERT_EQ(WEXITSTATUS(status), kChildMainThreadExitCode);
-}
-
-// Like base:SleepFor, but tries to avoid counting time spent stopped due to a
-// stop signal toward the sleep.
-//
-// This is required due to an inconsistency in how nanosleep(2) and stop signals
-// interact on Linux. When nanosleep is interrupted, it writes the remaining
-// time back to its second timespec argument, so that if nanosleep is
-// interrupted by a signal handler then userspace can immediately call nanosleep
-// again with that timespec. However, if nanosleep is automatically restarted
-// (because it's interrupted by a signal that is not delivered to a handler,
-// such as a stop signal), it's restarted based on the timer's former *absolute*
-// expiration time (via ERESTART_RESTARTBLOCK => SYS_restart_syscall =>
-// hrtimer_nanosleep_restart). This means that time spent stopped is effectively
-// counted as time spent sleeping, resulting in less time spent sleeping than
-// expected.
-//
-// Dividing the sleep into multiple smaller sleeps limits the impact of this
-// effect to the length of each sleep during which a stop occurs; for example,
-// if a sleeping process is only stopped once, SleepIgnoreStopped can
-// under-sleep by at most 100ms.
-void SleepIgnoreStopped(absl::Duration d) {
- absl::Duration const max_sleep = absl::Milliseconds(100);
- while (d > absl::ZeroDuration()) {
- absl::Duration to_sleep = std::min(d, max_sleep);
- absl::SleepFor(to_sleep);
- d -= to_sleep;
- }
-}
-
-TEST(SigstopTest, RestartSyscall) {
- pid_t pid;
- constexpr absl::Duration kStopDelay = absl::Seconds(5);
- constexpr absl::Duration kSleepDelay = absl::Seconds(15);
- constexpr absl::Duration kStartupDelay = absl::Seconds(5);
- constexpr absl::Duration kErrorDelay = absl::Seconds(3);
-
- const DisableSave ds; // Timing-related.
-
- pid = fork();
- if (pid == 0) {
- struct timespec ts = {.tv_sec = kSleepDelay / absl::Seconds(1)};
- auto start = absl::Now();
- TEST_CHECK(nanosleep(&ts, nullptr) == 0);
- auto finish = absl::Now();
- // Check that time spent stopped is counted as time spent sleeping.
- TEST_CHECK(finish - start >= kSleepDelay);
- TEST_CHECK(finish - start < kSleepDelay + kErrorDelay);
- _exit(kChildMainThreadExitCode);
- }
- ASSERT_THAT(pid, SyscallSucceeds());
-
- // Wait for the child subprocess to start sleeping before stopping it.
- absl::SleepFor(kStartupDelay);
- ASSERT_THAT(kill(pid, SIGSTOP), SyscallSucceeds());
- int status;
- EXPECT_THAT(RetryEINTR(waitpid)(pid, &status, WUNTRACED),
- SyscallSucceedsWithValue(pid));
- EXPECT_TRUE(WIFSTOPPED(status));
- EXPECT_EQ(SIGSTOP, WSTOPSIG(status));
-
- // Sleep for shorter than the sleep in the child subprocess.
- absl::SleepFor(kStopDelay);
- ASSERT_THAT(RetryEINTR(waitpid)(pid, &status, WNOHANG),
- SyscallSucceedsWithValue(0));
-
- // Resume the child.
- ASSERT_THAT(kill(pid, SIGCONT), SyscallSucceeds());
-
- EXPECT_THAT(RetryEINTR(waitpid)(pid, &status, WCONTINUED),
- SyscallSucceedsWithValue(pid));
- EXPECT_TRUE(WIFCONTINUED(status));
-
- // Expect it to die.
- ASSERT_THAT(RetryEINTR(waitpid)(pid, &status, 0), SyscallSucceeds());
- ASSERT_TRUE(WIFEXITED(status));
- ASSERT_EQ(WEXITSTATUS(status), kChildMainThreadExitCode);
-}
-
-void RunChild() {
- // Start another thread that attempts to call exit_group with a different
- // error code, in order to verify that SIGSTOP stops this thread as well.
- ScopedThread t([] {
- SleepIgnoreStopped(kChildExtraThreadDelay);
- exit(kChildExtraThreadExitCode);
- });
- SleepIgnoreStopped(kChildMainThreadDelay);
- exit(kChildMainThreadExitCode);
-}
-
-} // namespace
-
-} // namespace testing
-} // namespace gvisor
-
-int main(int argc, char** argv) {
- gvisor::testing::TestInit(&argc, &argv);
-
- if (absl::GetFlag(FLAGS_sigstop_test_child)) {
- gvisor::testing::RunChild();
- return 1;
- }
-
- return gvisor::testing::RunAllTests();
-}