Index: llvm-toolchain-snapshot_9~svn353038/libcxx/include/__config
===================================================================
--- llvm-toolchain-snapshot_9~svn353038.orig/libcxx/include/__config
+++ llvm-toolchain-snapshot_9~svn353038/libcxx/include/__config
@@ -1157,6 +1157,7 @@ _LIBCPP_FUNC_VIS extern "C" void __sanit
     !defined(_LIBCPP_HAS_THREAD_API_WIN32) && \
     !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
 #  if defined(__FreeBSD__) || \
+      defined(__FreeBSD_kernel__) || \
       defined(__Fuchsia__) || \
       defined(__NetBSD__) || \
       defined(__linux__) || \