[linux-next:master 6492/7272] kernel/watchdog.c:111:12: warning: 'hardlockup_all_cpu_backtrace_proc_handler' defined but not used

[linux-next:master 6492/7272] kernel/watchdog.c:111:12: warning: 'hardlockup_all_cpu_backtrace_proc_handler' defined but not used

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   bdffb18b5dd8071cd25685b966f380a30b1fadaa
commit: 838b3b76220d5b1bc53e4186d8936c5ec6810bf0 [6492/7272] watchdog/hardlockup: avoid large stack frames in watchdog_hardlockup_check()
config: x86_64-randconfig-x012-20230731 (https://download.01.org/0day-ci/archive/20230804/202308041501.2T8kM1gb-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230804/202308041501.2T8kM1gb-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308041501.2T8kM1gb-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/watchdog.c:111:12: warning: 'hardlockup_all_cpu_backtrace_proc_handler' defined but not used [-Wunused-function]
     111 | static int hardlockup_all_cpu_backtrace_proc_handler(struct ctl_table *table, int write,
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/hardlockup_all_cpu_backtrace_proc_handler +111 kernel/watchdog.c

   110	
 > 111	static int hardlockup_all_cpu_backtrace_proc_handler(struct ctl_table *table, int write,
   112			  void *buffer, size_t *lenp, loff_t *ppos)
   113	{
   114		int ret;
   115	
   116		ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
   117	
   118		/*
   119		 * Only allocate memory for the backtrace mask if userspace actually
   120		 * wants to trace all CPUs since this can take up 1K of space on a
   121		 * system with CONFIG_NR_CPUS=8192.
   122		 */
   123		if (sysctl_hardlockup_all_cpu_backtrace && !hardlockup_backtrace_mask) {
   124			hardlockup_backtrace_mask =
   125				   kzalloc(sizeof(*hardlockup_backtrace_mask), GFP_KERNEL);
   126		} else if (!sysctl_hardlockup_all_cpu_backtrace && hardlockup_backtrace_mask) {
   127			kfree(hardlockup_backtrace_mask);
   128			hardlockup_backtrace_mask = NULL;
   129		}
   130	
   131		return ret;
   132	}
   133	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [linux-next:master 6492/7272] kernel/watchdog.c:111:12: warning: 'hardlockup_all_cpu_backtrace_proc_handler' defined but not used

[Doug Anderson]

Hi,

On Fri, Aug 4, 2023 at 12:19 AM kernel test robot <lkp@intel.com> wrote:
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   bdffb18b5dd8071cd25685b966f380a30b1fadaa
> commit: 838b3b76220d5b1bc53e4186d8936c5ec6810bf0 [6492/7272] watchdog/hardlockup: avoid large stack frames in watchdog_hardlockup_check()
> config: x86_64-randconfig-x012-20230731 (https://download.01.org/0day-ci/archive/20230804/202308041501.2T8kM1gb-lkp@intel.com/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce: (https://download.01.org/0day-ci/archive/20230804/202308041501.2T8kM1gb-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202308041501.2T8kM1gb-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> >> kernel/watchdog.c:111:12: warning: 'hardlockup_all_cpu_backtrace_proc_handler' defined but not used [-Wunused-function]
>      111 | static int hardlockup_all_cpu_backtrace_proc_handler(struct ctl_table *table, int write,
>          |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
> vim +/hardlockup_all_cpu_backtrace_proc_handler +111 kernel/watchdog.c
>
>    110
>  > 111  static int hardlockup_all_cpu_backtrace_proc_handler(struct ctl_table *table, int write,

Leaving breadcrumbs here. The expected plan to fix this is to replace
the v2 patch with v4:

https://lore.kernel.org/r/20230804065935.v4.2.I501ab68cb926ee33a7c87e063d207abf09b9943c@changeid/

-Doug