Hi Nathan,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   b7cbaf59f62f8ab8f157698f9e31642bff525bd0
commit: c39866f268f89868df17724cd2262d121552d8c9 arm/build: Always handle .ARM.exidx and .ARM.extab sections
date:   7 days ago
config: arm-randconfig-r016-20201102 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project cc91554ebb66e8c9a4b8c67ca2f1343eaac10cf6)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c39866f268f89868df17724cd2262d121552d8c9
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout c39866f268f89868df17724cd2262d121552d8c9
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "__aeabi_unwind_cpp_pr0" [kernel/trace/preemptirq_delay_test.ko] undefined!
>> ERROR: modpost: "__aeabi_unwind_cpp_pr0" [kernel/trace/ring_buffer_benchmark.ko] undefined!

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org