[kbuild-all] [dm:for-next 16/21] drivers/md/dm-dust.c:307:10: warning: zero-length gnu_printf format string

tree: https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git for-next head: d88c192d8c466e0d004f451091c409aa87c5ca89 commit: 20f93ea74f9c3274879328b9e1a2a85bc0cca5fd [16/21] dm dust: add interface to list all badblocks config: riscv-allyesconfig (attached as .config) compiler: riscv64-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 git checkout 20f93ea74f9c3274879328b9e1a2a85bc0cca5fd # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=riscv 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 drivers/md/dm-dust.c:11: drivers/md/dm-dust.c: In function 'dust_list_badblocks': 307 | DMEMIT(""); | ^~ include/linux/device-mapper.h:566:46: note: in definition of macro 'DMEMIT' 566 | 0 : scnprintf(result + sz, maxlen - sz, x)) | ^ vim +307 drivers/md/dm-dust.c 286 287 static int dust_list_badblocks(struct dust_device *dd, char *result, unsigned int maxlen, 288 unsigned int *sz_ptr) 289 { 290 unsigned long flags; 291 struct rb_root badblocklist; 292 struct rb_node *node; 293 struct badblock *bblk; 294 unsigned int sz = *sz_ptr; 295 unsigned long long num = 0; 296 297 spin_lock_irqsave(&dd->dust_lock, flags); 298 badblocklist = dd->badblocklist; 299 for (node = rb_first(&badblocklist); node; node = rb_next(node)) { 300 bblk = rb_entry(node, struct badblock, node); 301 DMEMIT("%llu\n", bblk->bb); 302 num++; 303 } 304 305 spin_unlock_irqrestore(&dd->dust_lock, flags); 306 if (!num) 308 309 return 1; 310 } 311 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org