Hi Alan,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   f88cd3fb9df228e5ce4e13ec3dbad671ddb2146e
commit: 31d0bc81637d8d974a6dad9827b765b4b70c89d7 bpf: Move to generic BTF show support, apply it to seq files/strings
date:   8 months ago
config: x86_64-rhel (attached as .config)
compiler: gcc-6 (Ubuntu 6.4.0-17ubuntu1) 6.4.0 20180424
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=31d0bc81637d8d974a6dad9827b765b4b70c89d7
        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
        make W=1 ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   kernel/bpf/btf.c: In function 'btf_seq_show':
>> kernel/bpf/btf.c:5346:22: warning: function might be possible candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
     seq_vprintf((struct seq_file *)show->target, fmt, args);
                         ^~~~~~~~
   kernel/bpf/btf.c: In function 'btf_snprintf_show':
   kernel/bpf/btf.c:5383:2: warning: function might be possible candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
     len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
     ^~~


vim +/gnu_printf +5346 kernel/bpf/btf.c

  5342	
  5343	static void btf_seq_show(struct btf_show *show, const char *fmt,
  5344				 va_list args)
  5345	{
> 5346		seq_vprintf((struct seq_file *)show->target, fmt, args);
  5347	}
  5348	

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