diff --git a/libc/kernel/uapi/linux/bits.h b/libc/kernel/uapi/linux/bits.h
new file mode 100644
index 0000000..d747e24
--- /dev/null
+++ b/libc/kernel/uapi/linux/bits.h
@@ -0,0 +1,11 @@
+/*
+ * This file is auto-generated. Modifications will be lost.
+ *
+ * See https://android.googlesource.com/platform/bionic/+/master/libc/kernel/
+ * for more information.
+ */
+#ifndef _UAPI_LINUX_BITS_H
+#define _UAPI_LINUX_BITS_H
+#define __GENMASK(h,l) (((~_UL(0)) - (_UL(1) << (l)) + 1) & (~_UL(0) >> (__BITS_PER_LONG - 1 - (h))))
+#define __GENMASK_ULL(h,l) (((~_ULL(0)) - (_ULL(1) << (l)) + 1) & (~_ULL(0) >> (__BITS_PER_LONG_LONG - 1 - (h))))
+#endif