[jolsa-perf:bpf/tracing_multi_1 25/27] kernel/trace/ftrace.c:5595:22: warning: variable 'err' set but not used

[jolsa-perf:bpf/tracing_multi_1 25/27] kernel/trace/ftrace.c:5595:22: warning: variable 'err' set but not used

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git bpf/tracing_multi_1
head:   747784185d106a06b429736196d8817cb2d12a6f
commit: 553555d3ff275b63f8edf8a7b20861d4a01c8918 [25/27] ftrace: Add add_direct_functions_hash function
config: x86_64-rhel-8.3-kselftests (https://download.01.org/0day-ci/archive/20230119/202301191214.ACiV9GxE-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git/commit/?id=553555d3ff275b63f8edf8a7b20861d4a01c8918
        git remote add jolsa-perf https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
        git fetch --no-tags jolsa-perf bpf/tracing_multi_1
        git checkout 553555d3ff275b63f8edf8a7b20861d4a01c8918
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

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

All warnings (new ones prefixed by >>):

   kernel/trace/ftrace.c:299:5: warning: no previous prototype for '__register_ftrace_function' [-Wmissing-prototypes]
     299 | int __register_ftrace_function(struct ftrace_ops *ops)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/ftrace.c:342:5: warning: no previous prototype for '__unregister_ftrace_function' [-Wmissing-prototypes]
     342 | int __unregister_ftrace_function(struct ftrace_ops *ops)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/ftrace.c:4009:15: warning: no previous prototype for 'arch_ftrace_match_adjust' [-Wmissing-prototypes]
    4009 | char * __weak arch_ftrace_match_adjust(char *str, const char *search)
         |               ^~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/ftrace.c: In function 'add_direct_functions_hash':
>> kernel/trace/ftrace.c:5595:22: warning: variable 'err' set but not used [-Wunused-but-set-variable]
    5595 |         int size, i, err;
         |                      ^~~


vim +/err +5595 kernel/trace/ftrace.c

  5590	
  5591	static int add_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr,
  5592					     struct ftrace_hash **free_hash)
  5593	{
  5594		struct ftrace_func_entry *entry, *new;
> 5595		int size, i, err;
  5596	
  5597		/* Make sure requested entries are not already registered.. */
  5598		size = 1 << hash->size_bits;
  5599		for (i = 0; i < size; i++) {
  5600			hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
  5601				if (ftrace_find_rec_direct(entry->ip))
  5602				return -EINVAL;
  5603			}
  5604		}
  5605	
  5606		/* ... and insert them to direct_functions hash. */
  5607		err = -ENOMEM;
  5608		for (i = 0; i < size; i++) {
  5609			hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
  5610				new = ftrace_add_rec_direct(entry->ip, addr, free_hash);
  5611				if (!new)
  5612					return -ENOMEM;
  5613				entry->direct = addr;
  5614			}
  5615		}
  5616		return 0;
  5617	}
  5618	

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