Re: [PATCH v2 4/4] slub: Force on no_hash_pointers when slub_debug is enabled

[kernel test robot <lkp@intel.com>]

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Hi Stephen,

I love your patch! Perhaps something to improve:

[auto build test WARNING on d07f6ca923ea0927a1024dfccafc5b53b61cfecc]

url:    https://github.com/0day-ci/linux/commits/Stephen-Boyd/slub-Print-non-hashed-pointers-in-slub-debugging/20210526-105816
base:   d07f6ca923ea0927a1024dfccafc5b53b61cfecc
config: i386-tinyconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/1e3e0117436276faacd0217d89715df61021b4d2
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Stephen-Boyd/slub-Print-non-hashed-pointers-in-slub-debugging/20210526-105816
        git checkout 1e3e0117436276faacd0217d89715df61021b4d2
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

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 >>):

   lib/vsprintf.c: In function 'va_format':
   lib/vsprintf.c:1663:2: warning: function 'va_format' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
    1663 |  buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
         |  ^~~
   lib/vsprintf.c: At top level:
>> lib/vsprintf.c:2189:12: warning: no previous prototype for 'no_hash_pointers_enable' [-Wmissing-prototypes]
    2189 | int __init no_hash_pointers_enable(char *str)
         |            ^~~~~~~~~~~~~~~~~~~~~~~


vim +/no_hash_pointers_enable +2189 lib/vsprintf.c

  2188	
> 2189	int __init no_hash_pointers_enable(char *str)
  2190	{
  2191		if (no_hash_pointers)
  2192			return 0;
  2193	
  2194		no_hash_pointers = true;
  2195	
  2196		pr_warn("**********************************************************\n");
  2197		pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
  2198		pr_warn("**                                                      **\n");
  2199		pr_warn("** This system shows unhashed kernel memory addresses   **\n");
  2200		pr_warn("** via the console, logs, and other interfaces. This    **\n");
  2201		pr_warn("** might reduce the security of your system.            **\n");
  2202		pr_warn("**                                                      **\n");
  2203		pr_warn("** If you see this message and you are not debugging    **\n");
  2204		pr_warn("** the kernel, report this immediately to your system   **\n");
  2205		pr_warn("** administrator!                                       **\n");
  2206		pr_warn("**                                                      **\n");
  2207		pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
  2208		pr_warn("**********************************************************\n");
  2209	
  2210		return 0;
  2211	}
  2212	early_param("no_hash_pointers", no_hash_pointers_enable);
  2213	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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