Update from chromium 62675d9fb31fb8cedc40f68e78e8445a74f362e7

sandbox/linux/tests/unit_tests.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <fcntl.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "base/debug/leak_annotations.h"
+#include "base/files/file_util.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/third_party/valgrind/valgrind.h"
+#include "build/build_config.h"
+#include "sandbox/linux/tests/unit_tests.h"
+
+namespace {
+std::string TestFailedMessage(const std::string& msg) {
+  return msg.empty() ? std::string() : "Actual test failure: " + msg;
+}
+
+int GetSubProcessTimeoutTimeInSeconds() {
+  // 10s ought to be enough for anybody.
+  return 10;
+}
+
+// Returns the number of threads of the current process or -1.
+int CountThreads() {
+  struct stat task_stat;
+  int task_d = stat("/proc/self/task", &task_stat);
+  // task_stat.st_nlink should be the number of tasks + 2 (accounting for
+  // "." and "..".
+  if (task_d != 0 || task_stat.st_nlink < 3)
+    return -1;
+  const int num_threads = task_stat.st_nlink - 2;
+  return num_threads;
+}
+
+}  // namespace
+
+namespace sandbox {
+
+bool IsAndroid() {
+#if defined(OS_ANDROID)
+  return true;
+#else
+  return false;
+#endif
+}
+
+bool IsArchitectureArm() {
+#if defined(ARCH_CPU_ARM_FAMILY)
+  return true;
+#else
+  return false;
+#endif
+}
+
+// TODO(jln): figure out why base/.../dynamic_annotations.h's
+// RunningOnValgrind() cannot link.
+bool IsRunningOnValgrind() { return RUNNING_ON_VALGRIND; }
+
+static const int kExpectedValue = 42;
+static const int kIgnoreThisTest = 43;
+static const int kExitWithAssertionFailure = 1;
+static const int kExitForTimeout = 2;
+
+#if !defined(OS_ANDROID)
+// This is due to StackDumpSignalHandler() performing _exit(1).
+// TODO(jln): get rid of the collision with kExitWithAssertionFailure.
+const int kExitAfterSIGSEGV = 1;
+#endif
+
+static void SigAlrmHandler(int) {
+  const char failure_message[] = "Timeout reached!\n";
+  // Make sure that we never block here.
+  if (!fcntl(2, F_SETFL, O_NONBLOCK)) {
+    ignore_result(write(2, failure_message, sizeof(failure_message) - 1));
+  }
+  _exit(kExitForTimeout);
+}
+
+// Set a timeout with a handler that will automatically fail the
+// test.
+static void SetProcessTimeout(int time_in_seconds) {
+  struct sigaction act = {};
+  act.sa_handler = SigAlrmHandler;
+  SANDBOX_ASSERT(sigemptyset(&act.sa_mask) == 0);
+  act.sa_flags = 0;
+
+  struct sigaction old_act;
+  SANDBOX_ASSERT(sigaction(SIGALRM, &act, &old_act) == 0);
+
+  // We don't implemenet signal chaining, so make sure that nothing else
+  // is expecting to handle SIGALRM.
+  SANDBOX_ASSERT((old_act.sa_flags & SA_SIGINFO) == 0);
+  SANDBOX_ASSERT(old_act.sa_handler == SIG_DFL);
+  sigset_t sigalrm_set;
+  SANDBOX_ASSERT(sigemptyset(&sigalrm_set) == 0);
+  SANDBOX_ASSERT(sigaddset(&sigalrm_set, SIGALRM) == 0);
+  SANDBOX_ASSERT(sigprocmask(SIG_UNBLOCK, &sigalrm_set, NULL) == 0);
+  SANDBOX_ASSERT(alarm(time_in_seconds) == 0);  // There should be no previous
+                                                // alarm.
+}
+
+// Runs a test in a sub-process. This is necessary for most of the code
+// in the BPF sandbox, as it potentially makes global state changes and as
+// it also tends to raise fatal errors, if the code has been used in an
+// insecure manner.
+void UnitTests::RunTestInProcess(SandboxTestRunner* test_runner,
+                                 DeathCheck death,
+                                 const void* death_aux) {
+  CHECK(test_runner);
+  // We need to fork(), so we can't be multi-threaded, as threads could hold
+  // locks.
+  int num_threads = CountThreads();
+#if !defined(THREAD_SANITIZER)
+  const int kNumExpectedThreads = 1;
+#else
+  // Under TSAN, there is a special helper thread. It should be completely
+  // invisible to our testing, so we ignore it. It should be ok to fork()
+  // with this thread. It's currently buggy, but it's the best we can do until
+  // there is a way to delay the start of the thread
+  // (https://code.google.com/p/thread-sanitizer/issues/detail?id=19).
+  const int kNumExpectedThreads = 2;
+#endif
+
+  // The kernel is at liberty to wake a thread id futex before updating /proc.
+  // If another test running in the same process has stopped a thread, it may
+  // appear as still running in /proc.
+  // We poll /proc, with an exponential back-off. At most, we'll sleep around
+  // 2^iterations nanoseconds in nanosleep().
+  for (unsigned int iteration = 0; iteration < 30; iteration++) {
+    struct timespec ts = {0, 1L << iteration /* nanoseconds */};
+    PCHECK(0 == HANDLE_EINTR(nanosleep(&ts, &ts)));
+    num_threads = CountThreads();
+    if (kNumExpectedThreads == num_threads)
+      break;
+  }
+
+  ASSERT_EQ(kNumExpectedThreads, num_threads)
+      << "Running sandbox tests with multiple threads "
+      << "is not supported and will make the tests flaky.";
+  int fds[2];
+  ASSERT_EQ(0, pipe(fds));
+  // Check that our pipe is not on one of the standard file descriptor.
+  SANDBOX_ASSERT(fds[0] > 2 && fds[1] > 2);
+
+  pid_t pid;
+  ASSERT_LE(0, (pid = fork()));
+  if (!pid) {
+    // In child process
+    // Redirect stderr to our pipe. This way, we can capture all error
+    // messages, if we decide we want to do so in our tests.
+    SANDBOX_ASSERT(dup2(fds[1], 2) == 2);
+    SANDBOX_ASSERT(!close(fds[0]));
+    SANDBOX_ASSERT(!close(fds[1]));
+
+    // Don't set a timeout if running on Valgrind, since it's generally much
+    // slower.
+    if (!IsRunningOnValgrind()) {
+      SetProcessTimeout(GetSubProcessTimeoutTimeInSeconds());
+    }
+
+    // Disable core files. They are not very useful for our individual test
+    // cases.
+    struct rlimit no_core = {0};
+    setrlimit(RLIMIT_CORE, &no_core);
+
+    test_runner->Run();
+    if (test_runner->ShouldCheckForLeaks()) {
+#if defined(LEAK_SANITIZER)
+      __lsan_do_leak_check();
+#endif
+    }
+    _exit(kExpectedValue);
+  }
+
+  close(fds[1]);
+  std::vector<char> msg_buf;
+  ssize_t rc;
+
+  // Make sure read() will never block as we'll use poll() to
+  // block with a timeout instead.
+  const int fcntl_ret = fcntl(fds[0], F_SETFL, O_NONBLOCK);
+  ASSERT_EQ(0, fcntl_ret);
+  struct pollfd poll_fd = {fds[0], POLLIN | POLLRDHUP, 0};
+
+  int poll_ret;
+  // We prefer the SIGALRM timeout to trigger in the child than this timeout
+  // so we double the common value here.
+  int poll_timeout = GetSubProcessTimeoutTimeInSeconds() * 2 * 1000;
+  while ((poll_ret = poll(&poll_fd, 1, poll_timeout) > 0)) {
+    const size_t kCapacity = 256;
+    const size_t len = msg_buf.size();
+    msg_buf.resize(len + kCapacity);
+    rc = HANDLE_EINTR(read(fds[0], &msg_buf[len], kCapacity));
+    msg_buf.resize(len + std::max(rc, static_cast<ssize_t>(0)));
+    if (rc <= 0)
+      break;
+  }
+  ASSERT_NE(poll_ret, -1) << "poll() failed";
+  ASSERT_NE(poll_ret, 0) << "Timeout while reading child state";
+  close(fds[0]);
+  std::string msg(msg_buf.begin(), msg_buf.end());
+
+  int status = 0;
+  int waitpid_returned = HANDLE_EINTR(waitpid(pid, &status, 0));
+  ASSERT_EQ(pid, waitpid_returned) << TestFailedMessage(msg);
+
+  // At run-time, we sometimes decide that a test shouldn't actually
+  // run (e.g. when testing sandbox features on a kernel that doesn't
+  // have sandboxing support). When that happens, don't attempt to
+  // call the "death" function, as it might be looking for a
+  // death-test condition that would never have triggered.
+  if (!WIFEXITED(status) || WEXITSTATUS(status) != kIgnoreThisTest ||
+      !msg.empty()) {
+    // We use gtest's ASSERT_XXX() macros instead of the DeathCheck
+    // functions.  This means, on failure, "return" is called. This
+    // only works correctly, if the call of the "death" callback is
+    // the very last thing in our function.
+    death(status, msg, death_aux);
+  }
+}
+
+void UnitTests::DeathSuccess(int status, const std::string& msg, const void*) {
+  std::string details(TestFailedMessage(msg));
+
+  bool subprocess_terminated_normally = WIFEXITED(status);
+  ASSERT_TRUE(subprocess_terminated_normally) << details;
+  int subprocess_exit_status = WEXITSTATUS(status);
+  ASSERT_EQ(kExpectedValue, subprocess_exit_status) << details;
+  bool subprocess_exited_but_printed_messages = !msg.empty();
+  EXPECT_FALSE(subprocess_exited_but_printed_messages) << details;
+}
+
+void UnitTests::DeathSuccessAllowNoise(int status,
+                                       const std::string& msg,
+                                       const void*) {
+  std::string details(TestFailedMessage(msg));
+
+  bool subprocess_terminated_normally = WIFEXITED(status);
+  ASSERT_TRUE(subprocess_terminated_normally) << details;
+  int subprocess_exit_status = WEXITSTATUS(status);
+  ASSERT_EQ(kExpectedValue, subprocess_exit_status) << details;
+}
+
+void UnitTests::DeathMessage(int status,
+                             const std::string& msg,
+                             const void* aux) {
+  std::string details(TestFailedMessage(msg));
+  const char* expected_msg = static_cast<const char*>(aux);
+
+  bool subprocess_terminated_normally = WIFEXITED(status);
+  ASSERT_TRUE(subprocess_terminated_normally) << "Exit status: " << status
+                                              << " " << details;
+  int subprocess_exit_status = WEXITSTATUS(status);
+  ASSERT_EQ(1, subprocess_exit_status) << details;
+
+  bool subprocess_exited_without_matching_message =
+      msg.find(expected_msg) == std::string::npos;
+  EXPECT_FALSE(subprocess_exited_without_matching_message) << details;
+}
+
+void UnitTests::DeathSEGVMessage(int status,
+                                 const std::string& msg,
+                                 const void* aux) {
+  std::string details(TestFailedMessage(msg));
+  const char* expected_msg = static_cast<const char*>(aux);
+
+#if defined(OS_ANDROID)
+  const bool subprocess_got_sigsegv =
+      WIFSIGNALED(status) && (SIGSEGV == WTERMSIG(status));
+#else
+  const bool subprocess_got_sigsegv =
+      WIFEXITED(status) && (kExitAfterSIGSEGV == WEXITSTATUS(status));
+#endif
+
+  ASSERT_TRUE(subprocess_got_sigsegv) << "Exit status: " << status
+                                      << " " << details;
+
+  bool subprocess_exited_without_matching_message =
+      msg.find(expected_msg) == std::string::npos;
+  EXPECT_FALSE(subprocess_exited_without_matching_message) << details;
+}
+
+void UnitTests::DeathExitCode(int status,
+                              const std::string& msg,
+                              const void* aux) {
+  int expected_exit_code = static_cast<int>(reinterpret_cast<intptr_t>(aux));
+  std::string details(TestFailedMessage(msg));
+
+  bool subprocess_terminated_normally = WIFEXITED(status);
+  ASSERT_TRUE(subprocess_terminated_normally) << details;
+  int subprocess_exit_status = WEXITSTATUS(status);
+  ASSERT_EQ(expected_exit_code, subprocess_exit_status) << details;
+}
+
+void UnitTests::DeathBySignal(int status,
+                              const std::string& msg,
+                              const void* aux) {
+  int expected_signo = static_cast<int>(reinterpret_cast<intptr_t>(aux));
+  std::string details(TestFailedMessage(msg));
+
+  bool subprocess_terminated_by_signal = WIFSIGNALED(status);
+  ASSERT_TRUE(subprocess_terminated_by_signal) << details;
+  int subprocess_signal_number = WTERMSIG(status);
+  ASSERT_EQ(expected_signo, subprocess_signal_number) << details;
+}
+
+void UnitTests::AssertionFailure(const char* expr, const char* file, int line) {
+  fprintf(stderr, "%s:%d:%s", file, line, expr);
+  fflush(stderr);
+  _exit(kExitWithAssertionFailure);
+}
+
+void UnitTests::IgnoreThisTest() {
+  fflush(stderr);
+  _exit(kIgnoreThisTest);
+}
+
+}  // namespace