[rtsan] Add pipe, mkfifo interceptors (llvm#116915)

## Why we think this are unsafe

Again, these correspond directly to system calls on linux and OSX. They
are two ways to do interprocess communication so it would make sense
that they take some synchronization by the OS.

compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp

@@ -736,6 +736,26 @@ INTERCEPTOR(int, kevent64, int kq, const struct kevent64_s *changelist,
 #define RTSAN_MAYBE_INTERCEPT_KEVENT64
 #endif // SANITIZER_INTERCEPT_KQUEUE
 
+INTERCEPTOR(int, pipe, int pipefd[2]) {
+  __rtsan_notify_intercepted_call("pipe");
+  return REAL(pipe)(pipefd);
+}
+
+INTERCEPTOR(int, mkfifo, const char *pathname, mode_t mode) {
+  __rtsan_notify_intercepted_call("mkfifo");
+  return REAL(mkfifo)(pathname, mode);
+}
+
+// see comment above about -Wunguarded-availability-new
+// and why we disable it here
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+INTERCEPTOR(int, mkfifoat, int dirfd, const char *pathname, mode_t mode) {
+  __rtsan_notify_intercepted_call("mkfifoat");
+  return REAL(mkfifoat)(dirfd, pathname, mode);
+}
+#pragma clang diagnostic pop
+
 // Preinit
 void __rtsan::InitializeInterceptors() {
   INTERCEPT_FUNCTION(calloc);
@@ -836,6 +856,10 @@ void __rtsan::InitializeInterceptors() {
   RTSAN_MAYBE_INTERCEPT_KQUEUE;
   RTSAN_MAYBE_INTERCEPT_KEVENT;
   RTSAN_MAYBE_INTERCEPT_KEVENT64;
+
+  INTERCEPT_FUNCTION(pipe);
+  INTERCEPT_FUNCTION(mkfifo);
+  INTERCEPT_FUNCTION(mkfifoat);
 }
 
 #endif // SANITIZER_POSIX

compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp

@@ -965,4 +965,32 @@ TEST_F(KqueueTest, Kevent64DiesWhenRealtime) {
 }
 #endif // SANITIZER_INTERCEPT_KQUEUE
 
+TEST(TestRtsanInterceptors, MkfifoDiesWhenRealtime) {
+  auto Func = []() { mkfifo("/tmp/rtsan_test_fifo", 0); };
+  ExpectRealtimeDeath(Func, "mkfifo");
+  ExpectNonRealtimeSurvival(Func);
+}
+
+#if __has_builtin(__builtin_available) && SANITIZER_APPLE
+#define MKFIFOAT_AVAILABLE() (__builtin_available(macOS 10.13, *))
+#else
+// We are going to assume this is true until we hit systems where it isn't
+#define MKFIFOAT_AVAILABLE() (true)
+#endif
+
+TEST(TestRtsanInterceptors, MkfifoatDiesWhenRealtime) {
+  if (MKFIFOAT_AVAILABLE()) {
+    auto Func = []() { mkfifoat(0, "/tmp/rtsan_test_fifo", 0); };
+    ExpectRealtimeDeath(Func, "mkfifoat");
+    ExpectNonRealtimeSurvival(Func);
+  }
+}
+
+TEST(TestRtsanInterceptors, PipeDiesWhenRealtime) {
+  int fds[2];
+  auto Func = [&fds]() { pipe(fds); };
+  ExpectRealtimeDeath(Func, "pipe");
+  ExpectNonRealtimeSurvival(Func);
+}
+
 #endif // SANITIZER_POSIX