[kbuild-all] arch/mips/boot/compressed/../../../../lib/lz4/lz4_decompress.c:506:5: warning: no previous prototype for 'LZ4_decompress_safe_forceExtDict'

Hi Randy, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 89d714ab6043bca7356b5c823f5335f5dce1f930 commit: 5ba3747dbc9ade2d22a8f5bff3c928cb41d35030 regulator: bd71815: add select to fix build date: 6 months ago config: mips-randconfig-r015-20211012 (attached as .config) compiler: mipsel-linux-gcc (GCC) 11.2.0 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/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 5ba3747dbc9ade2d22a8f5bff3c928cb41d35030 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): arch/mips/boot/compressed/decompress.c:40:6: warning: no previous prototype for 'error' [-Wmissing-prototypes] 40 | void error(char *x) | ^~~~~ In file included from arch/mips/boot/compressed/../../../../lib/decompress_unlz4.c:10, from arch/mips/boot/compressed/decompress.c:62: arch/mips/boot/compressed/../../../../lib/lz4/lz4_decompress.c:484:5: warning: no previous prototype for 'LZ4_decompress_safe_withPrefix64k' [-Wmissing-prototypes] 484 | int LZ4_decompress_safe_withPrefix64k(const char *source, char *dest, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 506 | int LZ4_decompress_safe_forceExtDict(const char *source, char *dest, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/mips/boot/compressed/decompress.c:83:6: warning: no previous prototype for '__stack_chk_fail' [-Wmissing-prototypes] 83 | void __stack_chk_fail(void) | ^~~~~~~~~~~~~~~~ arch/mips/boot/compressed/decompress.c:88:6: warning: no previous prototype for 'decompress_kernel' [-Wmissing-prototypes] 88 | void decompress_kernel(unsigned long boot_heap_start) | ^~~~~~~~~~~~~~~~~ vim +/LZ4_decompress_safe_forceExtDict +506 arch/mips/boot/compressed/../../../../lib/lz4/lz4_decompress.c cffb78b0e0b3a30 Kyungsik Lee 2013-07-08 505 2209fda323e2fd2 Gao Xiang 2018-10-30 @506 int LZ4_decompress_safe_forceExtDict(const char *source, char *dest, 2209fda323e2fd2 Gao Xiang 2018-10-30 507 int compressedSize, int maxOutputSize, 2209fda323e2fd2 Gao Xiang 2018-10-30 508 const void *dictStart, size_t dictSize) 2209fda323e2fd2 Gao Xiang 2018-10-30 509 { 2209fda323e2fd2 Gao Xiang 2018-10-30 510 return LZ4_decompress_generic(source, dest, 2209fda323e2fd2 Gao Xiang 2018-10-30 511 compressedSize, maxOutputSize, 2209fda323e2fd2 Gao Xiang 2018-10-30 512 endOnInputSize, decode_full_block, 2209fda323e2fd2 Gao Xiang 2018-10-30 513 usingExtDict, (BYTE *)dest, 2209fda323e2fd2 Gao Xiang 2018-10-30 514 (const BYTE *)dictStart, dictSize); 2209fda323e2fd2 Gao Xiang 2018-10-30 515 } 2209fda323e2fd2 Gao Xiang 2018-10-30 516 :::::: The code at line 506 was first introduced by commit :::::: 2209fda323e2fd2a2d0885595fd5097717f8d2aa lib/lz4: update LZ4 decompressor module :::::: TO: Gao Xiang <gaoxiang25(a)huawei.com&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org