gcc7 编译 linux内核提示 undefined reference to `____ilog2_NaN'

1. 问题

 gcc7.3 编译linux内核linux-4.10.4时，出现如下错误：

 

  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  LD      init/built-in.o
  LD      vmlinux.o
  MODPOST vmlinux.o
kernel/built-in.o: In function `update_wall_time':
/home/ubuntu/linux-4.10.4/kernel/time/timekeeping.c:2088: undefined reference to `____ilog2_NaN'
Makefile:969: recipe for target 'vmlinux' failed
make: *** [vmlinux] Error 1

2. 网上搜了下， 需要打patch

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/diff/?id=474c90156c8dcc2fa815e6716cc9394d7930cb9c

diff --git a/include/linux/log2.h b/include/linux/log2.h
index ef3d4f67118c..c373295f359f 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2