tree: https://github.com/norov/linux find_bit_smallconst head: 40c01d855243e956a0cb6a6174cd733c44fbd898 commit: 5af10bf6a355096faec4d126617e87090edf1fff [5/7] lib: add fast path for find_next_*_bit() config: m68k-randconfig-r005-20210120 (attached as .config) compiler: m68k-linux-gcc (GCC) 9.3.0 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://github.com/norov/linux/commit/5af10bf6a355096faec4d126617e87090ed... git remote add norov https://github.com/norov/linux git fetch --no-tags norov find_bit_smallconst git checkout 5af10bf6a355096faec4d126617e87090edf1fff # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All error/warnings (new ones prefixed by >>): In file included from arch/m68k/include/asm/bitops.h:526, from include/linux/bitops.h:47, from include/linux/kernel.h:11, from include/asm-generic/bug.h:20, from arch/m68k/include/asm/bug.h:32, from include/linux/bug.h:5, from include/linux/page-flags.h:10, from kernel/bounds.c:10: include/asm-generic/bitops/le.h: In function 'find_next_zero_bit_le': 45 | val = swab(*addr) | ~BITMAP_FIRST_WORD_MASK(offset); | ^~~~~ include/asm-generic/bitops/le.h: In function 'find_next_bit_le': include/asm-generic/bitops/le.h:69:14: warning: dereferencing 'void *' pointer 69 | val = swab(*addr) & BITMAP_FIRST_WORD_MASK(offset) | ^~~~~ include/asm-generic/bitops/le.h:69:14: error: invalid use of void expression -- In file included from arch/m68k/include/asm/bitops.h:526, from include/linux/bitops.h:47, from include/linux/kernel.h:11, from kernel//locking/locktorture.c:14: include/asm-generic/bitops/le.h: In function 'find_next_zero_bit_le': 45 | val = swab(*addr) | ~BITMAP_FIRST_WORD_MASK(offset); | ^~~~~ include/asm-generic/bitops/le.h: In function 'find_next_bit_le': include/asm-generic/bitops/le.h:69:14: warning: dereferencing 'void *' pointer 69 | val = swab(*addr) & BITMAP_FIRST_WORD_MASK(offset) | ^~~~~ include/asm-generic/bitops/le.h:69:14: error: invalid use of void expression In file included from include/linux/mmzone.h:19, from include/linux/gfp.h:6, from include/linux/umh.h:4, from include/linux/kmod.h:9, from include/linux/module.h:16, from kernel//locking/locktorture.c:15: include/linux/page-flags-layout.h: At top level: include/linux/page-flags-layout.h:6:10: fatal error: generated/bounds.h: No such file or directory 6 | #include <generated/bounds.h> | ^~~~~~~~~~~~~~~~~~~~ compilation terminated. -- In file included from arch/m68k/include/asm/bitops.h:526, from include/linux/bitops.h:47, from include/linux/kernel.h:11, from include/asm-generic/bug.h:20, from arch/m68k/include/asm/bug.h:32, from include/linux/bug.h:5, from include/linux/page-flags.h:10, from kernel/bounds.c:10: include/asm-generic/bitops/le.h: In function 'find_next_zero_bit_le': 45 | val = swab(*addr) | ~BITMAP_FIRST_WORD_MASK(offset); | ^~~~~ include/asm-generic/bitops/le.h: In function 'find_next_bit_le': include/asm-generic/bitops/le.h:69:14: warning: dereferencing 'void *' pointer 69 | val = swab(*addr) & BITMAP_FIRST_WORD_MASK(offset) | ^~~~~ include/asm-generic/bitops/le.h:69:14: error: invalid use of void expression make[2]: *** [scripts/Makefile.build:117: kernel/bounds.s] Error 1 make[2]: Target '__build' not remade because of errors. make[1]: *** [Makefile:1220: prepare0] Error 2 make[1]: Target 'modules_prepare' not remade because of errors. make: *** [Makefile:185: __sub-make] Error 2 make: Target 'modules_prepare' not remade because of errors. -- In file included from arch/m68k/include/asm/bitops.h:526, from include/linux/bitops.h:47, from include/linux/kernel.h:11, from include/asm-generic/bug.h:20, from arch/m68k/include/asm/bug.h:32, from include/linux/bug.h:5, from include/linux/page-flags.h:10, from kernel/bounds.c:10: include/asm-generic/bitops/le.h: In function 'find_next_zero_bit_le': 45 | val = swab(*addr) | ~BITMAP_FIRST_WORD_MASK(offset); | ^~~~~ include/asm-generic/bitops/le.h: In function 'find_next_bit_le': include/asm-generic/bitops/le.h:69:14: warning: dereferencing 'void *' pointer 69 | val = swab(*addr) & BITMAP_FIRST_WORD_MASK(offset) | ^~~~~ include/asm-generic/bitops/le.h:69:14: error: invalid use of void expression make[2]: *** [scripts/Makefile.build:117: kernel/bounds.s] Error 1 make[2]: Target '__build' not remade because of errors. make[1]: *** [Makefile:1220: prepare0] Error 2 make[1]: Target 'prepare' not remade because of errors. make: *** [Makefile:185: __sub-make] Error 2 make: Target 'prepare' not remade because of errors. vim +45 include/asm-generic/bitops/le.h 33 34 #ifndef find_next_zero_bit_le 35 static inline 36 unsigned long find_next_zero_bit_le(const void *addr, unsigned 37 long size, unsigned long offset) 38 { 39 if (small_const_nbits(size)) { 40 unsigned long val, idx; 41 42 if (unlikely(offset >= size)) 43 return size; 44 46 if (val == ~0UL) 47 return size; 48 49 idx = ffz(val); 50 51 return idx < size ? idx : size; 52 } 53 54 return _find_next_bit(addr, NULL, size, offset, ~0UL, 1); 55 } 56 #endif 57 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org