ERROR: modpost: "__st_r13_to_r15" [lib/zstd/zstd_decompress.ko] undefined!

[kernel test robot]

Hi Nick,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   dfd4b508c8c6106083698a0dd5e35aecc7c48725
commit: 65d1f5507ed2c78c64fce40e44e5574a9419eb09 zstd: Import upstream v1.5.7
date:   5 months ago
config: arc-randconfig-2006-20250816 (https://download.01.org/0day-ci/archive/20250816/202508160533.gJesbe9d-lkp@xxxxxxxxx/config)
compiler: arc-linux-gcc (GCC) 12.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250816/202508160533.gJesbe9d-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508160533.gJesbe9d-lkp@xxxxxxxxx/

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

ERROR: modpost: "__ld_r13_to_r23_ret" [lib/zstd/zstd_decompress.ko] undefined!
ERROR: modpost: "__st_r13_to_r22" [lib/zstd/zstd_decompress.ko] undefined!
ERROR: modpost: "__ld_r13_to_r16_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_r15" [lib/zstd/zstd_decompress.ko] undefined!
ERROR: modpost: "__st_r13_to_r16" [lib/zstd/zstd_decompress.ko] undefined!
ERROR: modpost: "__st_r13_to_r24" [lib/zstd/zstd_decompress.ko] undefined!
ERROR: modpost: "__st_r13_to_r19" [lib/zstd/zstd_decompress.ko] undefined!
>> ERROR: modpost: "__st_r13_to_r23" [lib/zstd/zstd_decompress.ko] undefined!
WARNING: modpost: suppressed 7 unresolved symbol warnings because there were too many)

-- 
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https://github.com/intel/lkp-tests/wiki