Index: lib/tsan/CMakeLists.txt
===================================================================
--- lib/tsan/CMakeLists.txt
+++ lib/tsan/CMakeLists.txt
@@ -25,24 +25,25 @@
 set(TSAN_SOURCES
   rtl/tsan_clock.cc
   rtl/tsan_debugging.cc
-  rtl/tsan_flags.cc
   rtl/tsan_fd.cc
+  rtl/tsan_flags.cc
   rtl/tsan_ignoreset.cc
   rtl/tsan_interceptors.cc
+  rtl/tsan_interface.cc
   rtl/tsan_interface_ann.cc
   rtl/tsan_interface_atomic.cc
-  rtl/tsan_interface.cc
   rtl/tsan_interface_java.cc
   rtl/tsan_malloc_mac.cc
   rtl/tsan_md5.cc
   rtl/tsan_mman.cc
   rtl/tsan_mutex.cc
   rtl/tsan_mutexset.cc
+  rtl/tsan_preinit.cc
   rtl/tsan_report.cc
   rtl/tsan_rtl.cc
   rtl/tsan_rtl_mutex.cc
-  rtl/tsan_rtl_report.cc
   rtl/tsan_rtl_proc.cc
+  rtl/tsan_rtl_report.cc
   rtl/tsan_rtl_thread.cc
   rtl/tsan_stack_trace.cc
   rtl/tsan_stat.cc
@@ -117,7 +118,7 @@
                 RTUbsan
     CFLAGS ${TSAN_RTL_CFLAGS}
     PARENT_TARGET tsan)
-  add_compiler_rt_object_libraries(RTTsan_dynamic 
+  add_compiler_rt_object_libraries(RTTsan_dynamic
     OS ${TSAN_SUPPORTED_OS}
     ARCHS ${TSAN_SUPPORTED_ARCH}
     SOURCES ${TSAN_SOURCES} ${TSAN_CXX_SOURCES} ${TSAN_ASM_SOURCES}
@@ -197,7 +198,7 @@
 # FreeBSD does not install a number of Clang-provided headers for the compiler
 # in the base system due to incompatibilities between FreeBSD's and Clang's
 # versions. As a workaround do not use --sysroot=. on FreeBSD until this is
-# addressed.                                                        
+# addressed.
 if(COMPILER_RT_HAS_SYSROOT_FLAG AND NOT CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
   file(GLOB _tsan_generic_sources rtl/tsan*)
   file(GLOB _tsan_platform_sources rtl/tsan*posix* rtl/tsan*mac*
Index: lib/tsan/rtl/tsan_preinit.cc
===================================================================
--- /dev/null
+++ lib/tsan/rtl/tsan_preinit.cc
@@ -0,0 +1,25 @@
+//===-- tsan_preinit.cc ---------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer.
+//
+// Call __tsan_init at the very early stage of process startup.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_internal_defs.h"
+#include "tsan_interface.h"
+
+#if SANITIZER_CAN_USE_PREINIT_ARRAY
+  // The symbol is called __local_tsan_preinit, because it's not intended to be
+  // exported.
+  // This code linked into the main executable when -fsanitize=thread is in
+  // the link flags. It can only use exported interface functions.
+  __attribute__((section(".preinit_array"), used))
+  void (*__local_tsan_preinit)(void) = __tsan_init;
+#endif