tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 2052923327794192c5d884623b5ee5fec1867bda commit: d106ad47e292fde47fc09e16a2ddc13609ff2ad1 [5868/6773] mm-fix-phys_to_target_node-and-memory_add_physaddr_to_nid-exports-v4 config: powerpc64-randconfig-r026-20201118 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project b2613fb2f0f53691dd0211895afbb9413457fca7) 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 # install powerpc64 cross compiling tool for clang build # apt-get install binutils-powerpc64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout d106ad47e292fde47fc09e16a2ddc13609ff2ad1 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64

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/powerpc/mm/mem.c:91:12: warning: no previous prototype for function 'create_section_mapping' [-Wmissing-prototypes] int __weak create_section_mapping(unsigned long start, unsigned long end, ^ arch/powerpc/mm/mem.c:91:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int __weak create_section_mapping(unsigned long start, unsigned long end, ^ static 1 warning generated.

On Wed, Nov 18, 2020 at 11:22 AM Dan Williams <dan.j.williams(a)intel.com&gt; wrote: > > On Wed, Nov 18, 2020 at 4:27 AM kernel test robot <lkp(a)intel.com&gt; wrote: >> >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master >> head: 2052923327794192c5d884623b5ee5fec1867bda >> commit: d106ad47e292fde47fc09e16a2ddc13609ff2ad1 [5868/6773] mm-fix-phys_to_target_node-and-memory_add_physaddr_to_nid-exports-v4 >> config: powerpc64-randconfig-r026-20201118 (attached as .config) ^ randconfig >> compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project b2613fb2f0f53691dd0211895afbb9413457fca7) >> reproduce (this is a W=1 build): ^ W=1 >> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross >> chmod +x ~/bin/make.cross >> # install powerpc64 cross compiling tool for clang build >> # apt-get install binutils-powerpc64-linux-gnu >> # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... >> git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git >> git fetch --no-tags linux-next master >> git checkout d106ad47e292fde47fc09e16a2ddc13609ff2ad1 >> # save the attached .config to linux build tree >> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 > > I get: > > Makefile:597: arch/powerpc64/Makefile: No such file or directory > make[1]: *** No rule to make target 'arch/powerpc64/Makefile'. Stop. > make: *** [Makefile:712: include/config/auto.conf.cmd] Error 2 > > ...changing it to ARCH=powerpc I get: > > Assembler messages: > Fatal error: invalid listing option `3' > clang: error: assembler command failed with exit code 1 (use -v to see > invocation) > make[1]: *** [scripts/Makefile.build:283: scripts/mod/empty.o] Error 1 > make[1]: *** Waiting for unfinished jobs.... > make: *** [Makefile:1199: prepare0] Error 2 > > This is on a Fedora 31 host. > >> >> 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/powerpc/mm/mem.c:91:12: warning: no previous prototype for function 'create_section_mapping' [-Wmissing-prototypes] >> int __weak create_section_mapping(unsigned long start, unsigned long end, >> ^ >> arch/powerpc/mm/mem.c:91:1: note: declare 'static' if the function is not intended to be used outside of this translation unit >> int __weak create_section_mapping(unsigned long start, unsigned long end, >> ^ >> static >> 1 warning generated. > > I do not see these errors with gcc. > > I feel like clang errors should be flagged / de-emphasized when the > same error does not appear on gcc. Note this is a W=1 build. For this warning, you either need to mark functions as having static linkage, or provide a prototype in a header so that callers know the correct function signature.

On Wed, Nov 18, 2020 at 1:20 PM Randy Dunlap <rdunlap(a)infradead.org&gt; wrote: [..] > Yes, so with gcc, that gave me something like 109 missing prototype > warnings -- including one for 'create_section_mapping'. You see those with this [1] applied? I don't see those warnings anymore with gcc-10.2.0 and that patch. [1]: http://lore.kernel.org/r/160558386174.2948926.2740149041249041764.stgit@d...