Hi Alan, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: a90af8f15bdc9449ee2d24e1d73fa3f7e8633f81 commit: 31d0bc81637d8d974a6dad9827b765b4b70c89d7 bpf: Move to generic BTF show support, apply it to seq files/strings date: 1 year, 2 months ago config: nds32-buildonly-randconfig-r002-20210927 (attached as .config) compiler: nds32le-linux-gcc (GCC) 11.2.0 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 31d0bc81637d8d974a6dad9827b765b4b70c89d7 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=nds32 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 >>): kernel/bpf/btf.c: In function 'btf_seq_show': 5346 | seq_vprintf((struct seq_file *)show->target, fmt, args); | ^~~~~~~~ kernel/bpf/btf.c: In function 'btf_snprintf_show': 5383 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); | ^~~ vim +5346 kernel/bpf/btf.c 5342 5343 static void btf_seq_show(struct btf_show *show, const char *fmt, 5344 va_list args) 5345 { 5347 } 5348 5349 static int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, 5350 void *obj, struct seq_file *m, u64 flags) 5351 { 5352 struct btf_show sseq; 5353 5354 sseq.target = m; 5355 sseq.showfn = btf_seq_show; 5356 sseq.flags = flags; 5357 5358 btf_type_show(btf, type_id, obj, &sseq); 5359 5360 return sseq.state.status; 5361 } 5362 5363 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, 5364 struct seq_file *m) 5365 { 5366 (void) btf_type_seq_show_flags(btf, type_id, obj, m, 5367 BTF_SHOW_NONAME | BTF_SHOW_COMPACT | 5368 BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); 5369 } 5370 5371 struct btf_show_snprintf { 5372 struct btf_show show; 5373 int len_left; /* space left in string */ 5374 int len; /* length we would have written */ 5375 }; 5376 5377 static void btf_snprintf_show(struct btf_show *show, const char *fmt, 5378 va_list args) 5379 { 5380 struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; 5381 int len; 5382 5384 5385 if (len < 0) { 5386 ssnprintf->len_left = 0; 5387 ssnprintf->len = len; 5388 } else if (len > ssnprintf->len_left) { 5389 /* no space, drive on to get length we would have written */ 5390 ssnprintf->len_left = 0; 5391 ssnprintf->len += len; 5392 } else { 5393 ssnprintf->len_left -= len; 5394 ssnprintf->len += len; 5395 show->target += len; 5396 } 5397 } 5398 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org