Hi Josh, I love your patch! Yet something to improve: [auto build test ERROR on tip/master] [also build test ERROR on linus/master v5.11-rc3 next-20210115] [cannot apply to xen-tip/linux-next tip/x86/core] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Josh-Poimboeuf/objtool-vmlinux-o... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 2c2adbc40b7276518921864053f3c02034b2290f config: x86_64-rhel (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/f06729b24980b0cdff19419510b17f5b4... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Josh-Poimboeuf/objtool-vmlinux-o-and-CLANG-LTO-support/20210115-125439 git checkout f06729b24980b0cdff19419510b17f5b493dc756 # save the attached .config to linux build tree make W=1 ARCH=x86_64 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 >>): elf.c: In function 'read_symbols': 409 | char *coldstr; | ^~~~~~~ cc1: all warnings being treated as errors make[4]: *** [tools/build/Makefile.build:96: tools/objtool/elf.o] Error 1 make[3]: *** [Makefile:59: tools/objtool/objtool-in.o] Error 2 -- elf.c: In function 'read_symbols': 409 | char *coldstr; | ^~~~~~~ cc1: all warnings being treated as errors make[4]: *** [tools/build/Makefile.build:96: tools/objtool/elf.o] Error 1 make[3]: *** [Makefile:59: tools/objtool/objtool-in.o] Error 2 make[2]: *** [Makefile:68: objtool] Error 2 make[1]: *** [Makefile:1931: tools/objtool] Error 2 make[1]: Target 'modules_prepare' not remade because of errors. make: *** [Makefile:185: __sub-make] Error 2 make: Target 'modules_prepare' not remade because of errors. -- elf.c: In function 'read_symbols': 409 | char *coldstr; | ^~~~~~~ cc1: all warnings being treated as errors make[4]: *** [tools/build/Makefile.build:96: tools/objtool/elf.o] Error 1 make[4]: *** Waiting for unfinished jobs.... make[3]: *** [Makefile:59: tools/objtool/objtool-in.o] Error 2 make[2]: *** [Makefile:68: objtool] Error 2 make[1]: *** [Makefile:1931: tools/objtool] Error 2 make[1]: Target 'prepare' not remade because of errors. make: *** [Makefile:185: __sub-make] Error 2 make: Target 'prepare' not remade because of errors. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org