Fix issue where CREAT flag was not properly passing mode

compiler-rt/lib/radsan/radsan_interceptors.cpp

@@ -51,21 +51,27 @@ INTERCEPTOR(int, open, const char *path, int oflag, ...) {
   // TODO Establish whether we should intercept here if the flag contains
   // O_NONBLOCK
   radsan::expectNotRealtime("open");
+
   va_list args;
   va_start(args, oflag);
-  auto result = REAL(open)(path, oflag, args);
+  const mode_t mode = va_arg(args, int);
   va_end(args);
+
+  const int result = REAL(open)(path, oflag, mode);
   return result;
 }
 
 INTERCEPTOR(int, openat, int fd, const char *path, int oflag, ...) {
   // TODO Establish whether we should intercept here if the flag contains
   // O_NONBLOCK
   radsan::expectNotRealtime("openat");
+
   va_list args;
   va_start(args, oflag);
-  auto result = REAL(openat)(fd, path, oflag, args);
+  mode_t mode = va_arg(args, int);
   va_end(args);
+
+  const int result = REAL(openat)(fd, path, oflag, mode);
   return result;
 }
 
@@ -79,11 +85,13 @@ INTERCEPTOR(int, creat, const char *path, mode_t mode) {
 
 INTERCEPTOR(int, fcntl, int filedes, int cmd, ...) {
   radsan::expectNotRealtime("fcntl");
+
   va_list args;
   va_start(args, cmd);
-  auto result = REAL(fcntl)(filedes, cmd, args);
+  void *arg = va_arg(args, void *);
   va_end(args);
-  return result;
+
+  return fcntl(filedes, cmd, arg);
 }
 
 INTERCEPTOR(int, close, int filedes) {

compiler-rt/lib/radsan/tests/radsan_test_interceptors.cpp

@@ -179,6 +179,22 @@ TEST(TestRadsanInterceptors, openatDiesWhenRealtime) {
   std::remove(temporary_file_path());
 }
 
+TEST(TestRadsanInterceptors, openCreatesFileWithProperMode) {
+  const int mode = S_IRGRP | S_IROTH | S_IRUSR | S_IWUSR;
+
+  const int fd = open(temporary_file_path(), O_CREAT | O_WRONLY, mode);
+  ASSERT_THAT(fd, Ne(-1));
+  close(fd);
+
+  struct stat st;
+  ASSERT_THAT(stat(temporary_file_path(), &st), Eq(0));
+
+  // Mask st_mode to get permission bits only
+  ASSERT_THAT(st.st_mode & 0777, Eq(mode));
+
+  std::remove(temporary_file_path());
+}
+
 TEST(TestRadsanInterceptors, creatDiesWhenRealtime) {
   auto func = []() { creat(temporary_file_path(), S_IWOTH | S_IROTH); };
   expectRealtimeDeath(func, "creat");
@@ -192,6 +208,28 @@ TEST(TestRadsanInterceptors, fcntlDiesWhenRealtime) {
   expectNonrealtimeSurvival(func);
 }
 
+TEST(TestRadsanInterceptors, fcntlFlockDiesWhenRealtime) {
+  int fd = creat(temporary_file_path(), S_IRUSR | S_IWUSR);
+  ASSERT_THAT(fd, Ne(-1));
+
+  auto func = [fd]() {
+    struct flock lock{};
+    lock.l_type = F_RDLCK;
+    lock.l_whence = SEEK_SET;
+    lock.l_start = 0;
+    lock.l_len = 0; 
+    lock.l_pid = ::getpid();
+
+    ASSERT_THAT(fcntl(fd, F_GETLK, &lock), Eq(0));
+    ASSERT_THAT(lock.l_type, F_UNLCK);
+  };
+  expectRealtimeDeath(func, "fcntl");
+  expectNonrealtimeSurvival(func);
+
+  close(fd);
+  std::remove(temporary_file_path());
+}
+
 TEST(TestRadsanInterceptors, closeDiesWhenRealtime) {
   auto func = []() { close(0); };
   expectRealtimeDeath(func, "close");