Hi Nick, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 5be860bfc73408bc1a8af9167955e480ecebba84 commit: 2aa14b1ab2c41a4fe41efae80d58bb77da91f19f [2415/12617] zstd: import usptream v1.5.2 config: arc-randconfig-r006-20221128 compiler: arc-elf-gcc (GCC) 12.1.0 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 # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=2aa14b1ab2c41a4fe41efae80d58bb77da91f19f git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 2aa14b1ab2c41a4fe41efae80d58bb77da91f19f # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All errors (new ones prefixed by >>, old ones prefixed by <<): ERROR: modpost: "__st_r13_to_r22" [lib/zstd/zstd_decompress.ko] undefined! ERROR: modpost: "__st_r13_to_r17" [lib/zstd/zstd_decompress.ko] undefined! >> ERROR: modpost: "__ld_r13_to_r21_ret" [lib/zstd/zstd_decompress.ko] undefined! ERROR: modpost: "__ld_r13_to_r19_ret" [lib/zstd/zstd_decompress.ko] undefined! ERROR: modpost: "__ld_r13_to_r22_ret" [lib/zstd/zstd_decompress.ko] undefined! ERROR: modpost: "__st_r13_to_r25" [lib/zstd/zstd_decompress.ko] undefined! ERROR: modpost: "__st_r13_to_r24" [lib/zstd/zstd_decompress.ko] undefined! ERROR: modpost: "__ld_r13_to_r17_ret" [lib/zstd/zstd_decompress.ko] undefined! >> ERROR: modpost: "__st_r13_to_r21" [lib/zstd/zstd_decompress.ko] undefined! ERROR: modpost: "__st_r13_to_r19" [lib/zstd/zstd_decompress.ko] undefined! WARNING: modpost: suppressed 5 unresolved symbol warnings because there were too many) -- 0-DAY CI Kernel Test Service https://01.org/lkp