[kbuild-all] arch/powerpc/boot/decompress.c:137: undefined reference to `__decompress'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: b85051e755b0e9d6dd8f17ef1da083851b83287d commit: 1cc9a21b0bb36debdf96dbcc4b139d6639373018 powerpc/boot: Add lzma support for uImage config: powerpc-randconfig-r012-20200520 (attached as .config) compiler: powerpc-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 git checkout 1cc9a21b0bb36debdf96dbcc4b139d6639373018 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>, old ones prefixed by <<): powerpc-linux-ld: arch/powerpc/boot/wrapper.a(decompress.o): in function `partial_decompress': # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git remote update linus git checkout 1cc9a21b0bb36debdf96dbcc4b139d6639373018 vim +137 arch/powerpc/boot/decompress.c 1b7898ee276b39 Oliver O'Halloran 2016-09-22 102 1b7898ee276b39 Oliver O'Halloran 2016-09-22 103 /** 1b7898ee276b39 Oliver O'Halloran 2016-09-22 104 * partial_decompress - decompresses part or all of a compressed buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 105 * @inbuf: input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 106 * @input_size: length of the input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 107 * @outbuf: input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 108 * @output_size: length of the input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 109 * @skip number of output bytes to ignore 1b7898ee276b39 Oliver O'Halloran 2016-09-22 110 * 1b7898ee276b39 Oliver O'Halloran 2016-09-22 111 * This function takes compressed data from inbuf, decompresses and write it to 1b7898ee276b39 Oliver O'Halloran 2016-09-22 112 * outbuf. Once output_size bytes are written to the output buffer, or the 1b7898ee276b39 Oliver O'Halloran 2016-09-22 113 * stream is exhausted the function will return the number of bytes that were 1b7898ee276b39 Oliver O'Halloran 2016-09-22 114 * decompressed. Otherwise it will return whatever error code the decompressor 1b7898ee276b39 Oliver O'Halloran 2016-09-22 115 * reported (NB: This is specific to each decompressor type). 1b7898ee276b39 Oliver O'Halloran 2016-09-22 116 * 1b7898ee276b39 Oliver O'Halloran 2016-09-22 117 * The skip functionality is mainly there so the program and discover 1b7898ee276b39 Oliver O'Halloran 2016-09-22 118 * the size of the compressed image so that it can ask firmware (if present) 1b7898ee276b39 Oliver O'Halloran 2016-09-22 119 * for an appropriately sized buffer. 1b7898ee276b39 Oliver O'Halloran 2016-09-22 120 */ 1b7898ee276b39 Oliver O'Halloran 2016-09-22 121 long partial_decompress(void *inbuf, unsigned long input_size, 1b7898ee276b39 Oliver O'Halloran 2016-09-22 122 void *outbuf, unsigned long output_size, unsigned long _skip) 1b7898ee276b39 Oliver O'Halloran 2016-09-22 123 { 1b7898ee276b39 Oliver O'Halloran 2016-09-22 124 int ret; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 125 1b7898ee276b39 Oliver O'Halloran 2016-09-22 126 /* 1b7898ee276b39 Oliver O'Halloran 2016-09-22 127 * The skipped bytes needs to be included in the size of data we want 1b7898ee276b39 Oliver O'Halloran 2016-09-22 128 * to decompress. 1b7898ee276b39 Oliver O'Halloran 2016-09-22 129 */ 1b7898ee276b39 Oliver O'Halloran 2016-09-22 130 output_size += _skip; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 131 1b7898ee276b39 Oliver O'Halloran 2016-09-22 132 decompressed_bytes = 0; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 133 output_buffer = outbuf; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 134 limit = output_size; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 135 skip = _skip; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 136 1b7898ee276b39 Oliver O'Halloran 2016-09-22 @137 ret = __decompress(inbuf, input_size, NULL, flush, outbuf, :::::: The code at line 137 was first introduced by commit :::::: 1b7898ee276b39e54d870dc4ef3374f663d0b426 powerpc/boot: Use the pre-boot decompression API :::::: TO: Oliver O'Halloran <oohall(a)gmail.com&gt; :::::: CC: Michael Ellerman <mpe(a)ellerman.id.au&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org