Hi Olaf, Thank you for the patch! Yet something to improve: [auto build test ERROR on kbuild/for-next] [also build test ERROR on linux/master linus/master v5.12-rc3 next-20210319] [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/Olaf-Hering/kbuild-enforce-Werro... base: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next config: alpha-allyesconfig (attached as .config) compiler: alpha-linux-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://github.com/0day-ci/linux/commit/635ecb94f0f38a005c528c2cddb9fc6f9... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Olaf-Hering/kbuild-enforce-Werror-unused-result/20210319-223913 git checkout 635ecb94f0f38a005c528c2cddb9fc6f9cfab1dc # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha 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 >>): fs/binfmt_em86.c: In function 'load_em86': 66 | remove_arg_zero(bprm); | ^~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/remove_arg_zero +66 fs/binfmt_em86.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 25 71613c3b871c5a Al Viro 2012-10-20 26 static int load_em86(struct linux_binprm *bprm) ^1da177e4c3f41 Linus Torvalds 2005-04-16 27 { a310dcb7a43f97 Daniel Wagner 2016-08-02 28 const char *i_name, *i_arg; a310dcb7a43f97 Daniel Wagner 2016-08-02 29 char *interp; ^1da177e4c3f41 Linus Torvalds 2005-04-16 30 struct file * file; ^1da177e4c3f41 Linus Torvalds 2005-04-16 31 int retval; ^1da177e4c3f41 Linus Torvalds 2005-04-16 32 struct elfhdr elf_ex; ^1da177e4c3f41 Linus Torvalds 2005-04-16 33 ^1da177e4c3f41 Linus Torvalds 2005-04-16 34 /* Make sure this is a Linux/Intel ELF executable... */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 35 elf_ex = *((struct elfhdr *)bprm->buf); ^1da177e4c3f41 Linus Torvalds 2005-04-16 36 ^1da177e4c3f41 Linus Torvalds 2005-04-16 37 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) ^1da177e4c3f41 Linus Torvalds 2005-04-16 38 return -ENOEXEC; ^1da177e4c3f41 Linus Torvalds 2005-04-16 39 ^1da177e4c3f41 Linus Torvalds 2005-04-16 40 /* First of all, some simple consistency checks */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 41 if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) || ^1da177e4c3f41 Linus Torvalds 2005-04-16 42 (!((elf_ex.e_machine == EM_386) || (elf_ex.e_machine == EM_486))) || 72c2d531920048 Al Viro 2013-09-22 43 !bprm->file->f_op->mmap) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 44 return -ENOEXEC; ^1da177e4c3f41 Linus Torvalds 2005-04-16 45 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 46 51f39a1f0cea1c David Drysdale 2014-12-12 47 /* Need to be able to load the file after exec */ 51f39a1f0cea1c David Drysdale 2014-12-12 48 if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE) 51f39a1f0cea1c David Drysdale 2014-12-12 49 return -ENOENT; 51f39a1f0cea1c David Drysdale 2014-12-12 50 ^1da177e4c3f41 Linus Torvalds 2005-04-16 51 /* Unlike in the script case, we don't have to do any hairy ^1da177e4c3f41 Linus Torvalds 2005-04-16 52 * parsing to find our interpreter... it's hardcoded! ^1da177e4c3f41 Linus Torvalds 2005-04-16 53 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 54 interp = EM86_INTERP; ^1da177e4c3f41 Linus Torvalds 2005-04-16 55 i_name = EM86_I_NAME; ^1da177e4c3f41 Linus Torvalds 2005-04-16 56 i_arg = NULL; /* We reserve the right to add an arg later */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 57 ^1da177e4c3f41 Linus Torvalds 2005-04-16 58 /* ^1da177e4c3f41 Linus Torvalds 2005-04-16 59 * Splice in (1) the interpreter's name for argv[0] ^1da177e4c3f41 Linus Torvalds 2005-04-16 60 * (2) (optional) argument to interpreter ^1da177e4c3f41 Linus Torvalds 2005-04-16 61 * (3) filename of emulated file (replace argv[0]) ^1da177e4c3f41 Linus Torvalds 2005-04-16 62 * ^1da177e4c3f41 Linus Torvalds 2005-04-16 63 * This is done in reverse order, because of how the ^1da177e4c3f41 Linus Torvalds 2005-04-16 64 * user environment and arguments are stored. ^1da177e4c3f41 Linus Torvalds 2005-04-16 65 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 @66 remove_arg_zero(bprm); 986db2d14a6dca Christoph Hellwig 2020-06-04 67 retval = copy_string_kernel(bprm->filename, bprm); ^1da177e4c3f41 Linus Torvalds 2005-04-16 68 if (retval < 0) return retval; ^1da177e4c3f41 Linus Torvalds 2005-04-16 69 bprm->argc++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 70 if (i_arg) { 986db2d14a6dca Christoph Hellwig 2020-06-04 71 retval = copy_string_kernel(i_arg, bprm); ^1da177e4c3f41 Linus Torvalds 2005-04-16 72 if (retval < 0) return retval; ^1da177e4c3f41 Linus Torvalds 2005-04-16 73 bprm->argc++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 74 } 986db2d14a6dca Christoph Hellwig 2020-06-04 75 retval = copy_string_kernel(i_name, bprm); ^1da177e4c3f41 Linus Torvalds 2005-04-16 76 if (retval < 0) return retval; ^1da177e4c3f41 Linus Torvalds 2005-04-16 77 bprm->argc++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 78 ^1da177e4c3f41 Linus Torvalds 2005-04-16 79 /* ^1da177e4c3f41 Linus Torvalds 2005-04-16 80 * OK, now restart the process with the interpreter's inode. ^1da177e4c3f41 Linus Torvalds 2005-04-16 81 * Note that we use open_exec() as the name is now in kernel ^1da177e4c3f41 Linus Torvalds 2005-04-16 82 * space, and we don't need to copy it. ^1da177e4c3f41 Linus Torvalds 2005-04-16 83 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 84 file = open_exec(interp); ^1da177e4c3f41 Linus Torvalds 2005-04-16 85 if (IS_ERR(file)) ^1da177e4c3f41 Linus Torvalds 2005-04-16 86 return PTR_ERR(file); ^1da177e4c3f41 Linus Torvalds 2005-04-16 87 bc2bf338d54b7a Eric W. Biederman 2020-05-18 88 bprm->interpreter = file; bc2bf338d54b7a Eric W. Biederman 2020-05-18 89 return 0; ^1da177e4c3f41 Linus Torvalds 2005-04-16 90 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 91 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org