[kbuild-all] arch/arm/boot/compressed/../../../../lib/lz4/lz4_decompress.c:480:5: warning: no previous prototype for 'LZ4_decompress_safe_withPrefix64k'

Hi Arnd, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: d434405aaab7d0ebc516b68a8fc4100922d7f5ef commit: 45fe7befe0db5e61cd3c846315f0ac48541e8445 coresight: remove broken __exit annotations date: 4 months ago config: arm-randconfig-r001-20210412 (attached as .config) compiler: arm-linux-gnueabi-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://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 45fe7befe0db5e61cd3c846315f0ac48541e8445 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm 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 >>): In file included from arch/arm/boot/compressed/../../../../lib/decompress_unlz4.c:10, from arch/arm/boot/compressed/decompress.c:56: 480 | int LZ4_decompress_safe_withPrefix64k(const char *source, char *dest, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 502 | int LZ4_decompress_safe_forceExtDict(const char *source, char *dest, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/arm/boot/compressed/decompress.c:59:5: warning: no previous prototype for 'do_decompress' [-Wmissing-prototypes] 59 | int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x)) | ^~~~~~~~~~~~~ vim +/LZ4_decompress_safe_withPrefix64k +480 arch/arm/boot/compressed/../../../../lib/lz4/lz4_decompress.c 2209fda323e2fd Gao Xiang 2018-10-30 479 2209fda323e2fd Gao Xiang 2018-10-30 @480 int LZ4_decompress_safe_withPrefix64k(const char *source, char *dest, 2209fda323e2fd Gao Xiang 2018-10-30 481 int compressedSize, int maxOutputSize) 2209fda323e2fd Gao Xiang 2018-10-30 482 { 2209fda323e2fd Gao Xiang 2018-10-30 483 return LZ4_decompress_generic(source, dest, 2209fda323e2fd Gao Xiang 2018-10-30 484 compressedSize, maxOutputSize, 2209fda323e2fd Gao Xiang 2018-10-30 485 endOnInputSize, decode_full_block, 2209fda323e2fd Gao Xiang 2018-10-30 486 withPrefix64k, 2209fda323e2fd Gao Xiang 2018-10-30 487 (BYTE *)dest - 64 * KB, NULL, 0); 2209fda323e2fd Gao Xiang 2018-10-30 488 } 2209fda323e2fd Gao Xiang 2018-10-30 489 2209fda323e2fd Gao Xiang 2018-10-30 490 static int LZ4_decompress_safe_withSmallPrefix(const char *source, char *dest, 2209fda323e2fd Gao Xiang 2018-10-30 491 int compressedSize, 2209fda323e2fd Gao Xiang 2018-10-30 492 int maxOutputSize, 2209fda323e2fd Gao Xiang 2018-10-30 493 size_t prefixSize) 2209fda323e2fd Gao Xiang 2018-10-30 494 { 2209fda323e2fd Gao Xiang 2018-10-30 495 return LZ4_decompress_generic(source, dest, 2209fda323e2fd Gao Xiang 2018-10-30 496 compressedSize, maxOutputSize, 2209fda323e2fd Gao Xiang 2018-10-30 497 endOnInputSize, decode_full_block, 2209fda323e2fd Gao Xiang 2018-10-30 498 noDict, 2209fda323e2fd Gao Xiang 2018-10-30 499 (BYTE *)dest - prefixSize, NULL, 0); 4e1a33b105ddf2 Sven Schmidt 2017-02-24 500 } cffb78b0e0b3a3 Kyungsik Lee 2013-07-08 501 2209fda323e2fd Gao Xiang 2018-10-30 @502 int LZ4_decompress_safe_forceExtDict(const char *source, char *dest, 2209fda323e2fd Gao Xiang 2018-10-30 503 int compressedSize, int maxOutputSize, 2209fda323e2fd Gao Xiang 2018-10-30 504 const void *dictStart, size_t dictSize) 2209fda323e2fd Gao Xiang 2018-10-30 505 { 2209fda323e2fd Gao Xiang 2018-10-30 506 return LZ4_decompress_generic(source, dest, 2209fda323e2fd Gao Xiang 2018-10-30 507 compressedSize, maxOutputSize, 2209fda323e2fd Gao Xiang 2018-10-30 508 endOnInputSize, decode_full_block, 2209fda323e2fd Gao Xiang 2018-10-30 509 usingExtDict, (BYTE *)dest, 2209fda323e2fd Gao Xiang 2018-10-30 510 (const BYTE *)dictStart, dictSize); 2209fda323e2fd Gao Xiang 2018-10-30 511 } 2209fda323e2fd Gao Xiang 2018-10-30 512 :::::: The code at line 480 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