[kbuild-all] arch/powerpc/boot/decompress.c:133: undefined reference to `__decompress'

Hi Masahiro, It's probably a bug fix that unveils the link errors. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 8b6ddd10d678bebec32381f71b6b420bafc43ad0 commit: 67bf47452ea00edd90e796054229b651e64b82c1 kbuild: update compile-test header list for v5.3-rc1 date: 11 months ago config: powerpc64-randconfig-c021-20200619 (attached as .config) compiler: powerpc-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): powerpc-linux-ld: arch/powerpc/boot/wrapper.a(decompress.o): in function `partial_decompress': vim +133 arch/powerpc/boot/decompress.c 1b7898ee276b39 Oliver O'Halloran 2016-09-22 98 1b7898ee276b39 Oliver O'Halloran 2016-09-22 99 /** 1b7898ee276b39 Oliver O'Halloran 2016-09-22 100 * partial_decompress - decompresses part or all of a compressed buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 101 * @inbuf: input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 102 * @input_size: length of the input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 103 * @outbuf: input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 104 * @output_size: length of the input buffer 1b7898ee276b39 Oliver O'Halloran 2016-09-22 105 * @skip number of output bytes to ignore 1b7898ee276b39 Oliver O'Halloran 2016-09-22 106 * 1b7898ee276b39 Oliver O'Halloran 2016-09-22 107 * This function takes compressed data from inbuf, decompresses and write it to 1b7898ee276b39 Oliver O'Halloran 2016-09-22 108 * outbuf. Once output_size bytes are written to the output buffer, or the 1b7898ee276b39 Oliver O'Halloran 2016-09-22 109 * stream is exhausted the function will return the number of bytes that were 1b7898ee276b39 Oliver O'Halloran 2016-09-22 110 * decompressed. Otherwise it will return whatever error code the decompressor 1b7898ee276b39 Oliver O'Halloran 2016-09-22 111 * reported (NB: This is specific to each decompressor type). 1b7898ee276b39 Oliver O'Halloran 2016-09-22 112 * 1b7898ee276b39 Oliver O'Halloran 2016-09-22 113 * The skip functionality is mainly there so the program and discover 1b7898ee276b39 Oliver O'Halloran 2016-09-22 114 * the size of the compressed image so that it can ask firmware (if present) 1b7898ee276b39 Oliver O'Halloran 2016-09-22 115 * for an appropriately sized buffer. 1b7898ee276b39 Oliver O'Halloran 2016-09-22 116 */ 1b7898ee276b39 Oliver O'Halloran 2016-09-22 117 long partial_decompress(void *inbuf, unsigned long input_size, 1b7898ee276b39 Oliver O'Halloran 2016-09-22 118 void *outbuf, unsigned long output_size, unsigned long _skip) 1b7898ee276b39 Oliver O'Halloran 2016-09-22 119 { 1b7898ee276b39 Oliver O'Halloran 2016-09-22 120 int ret; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 121 1b7898ee276b39 Oliver O'Halloran 2016-09-22 122 /* 1b7898ee276b39 Oliver O'Halloran 2016-09-22 123 * The skipped bytes needs to be included in the size of data we want 1b7898ee276b39 Oliver O'Halloran 2016-09-22 124 * to decompress. 1b7898ee276b39 Oliver O'Halloran 2016-09-22 125 */ 1b7898ee276b39 Oliver O'Halloran 2016-09-22 126 output_size += _skip; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 127 1b7898ee276b39 Oliver O'Halloran 2016-09-22 128 decompressed_bytes = 0; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 129 output_buffer = outbuf; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 130 limit = output_size; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 131 skip = _skip; 1b7898ee276b39 Oliver O'Halloran 2016-09-22 132 1b7898ee276b39 Oliver O'Halloran 2016-09-22 @133 ret = __decompress(inbuf, input_size, NULL, flush, outbuf, :::::: The code at line 133 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