[linux-next:master 6888/9480] kernel/rcu/../locking/rtmutex_common.h:231:35: error: static declaration of 'rt_mutex_owner' follows non-static declaration

[linux-next:master 6888/9480] kernel/rcu/../locking/rtmutex_common.h:231:35: error: static declaration of 'rt_mutex_owner' follows non-static declaration

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   3d7783543c2646af69ad65825e810060494bea21
commit: 1eccf02fb8d5359c4143cb50e6f52313b65fe7cd [6888/9480] rcu: Add running and boosted indications to RCU task stall dump
config: arm-randconfig-r1303-20260926 (https://download.01.org/0day-ci/archive/20260926/202609261005.GrnaXBXT-lkp@intel.com/config)
compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project 78ff5215e53a117851dc6e81e793a106f1a79df8)
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260926/202609261005.GrnaXBXT-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/202609261005.GrnaXBXT-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from kernel/rcu/tree.c:5001:
   kernel/rcu/tree_stall.h:333:8: error: call to undeclared function 'rt_mutex_owner'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     333 |                         if (rt_mutex_owner(&rnp->boost_mtx.rtmutex) == t)
         |                             ^
   kernel/rcu/tree_stall.h:333:48: warning: comparison between pointer and integer ('int' and 'struct task_struct *') [-Wpointer-integer-compare]
     333 |                         if (rt_mutex_owner(&rnp->boost_mtx.rtmutex) == t)
         |                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~
   In file included from kernel/rcu/tree.c:5004:
   In file included from kernel/rcu/tree_plugin.h:14:
>> kernel/rcu/../locking/rtmutex_common.h:231:35: error: static declaration of 'rt_mutex_owner' follows non-static declaration
     231 | static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock)
         |                                   ^
   kernel/rcu/tree_stall.h:333:8: note: previous implicit declaration is here
     333 |                         if (rt_mutex_owner(&rnp->boost_mtx.rtmutex) == t)
         |                             ^
   1 warning and 2 errors generated.


vim +/rt_mutex_owner +231 kernel/rcu/../locking/rtmutex_common.h

c014ef69b3acdb Thomas Gleixner 2021-08-15  228  
531ae4b06a737e Thomas Gleixner 2021-08-15  229  #else /* CONFIG_RT_MUTEXES */
531ae4b06a737e Thomas Gleixner 2021-08-15  230  /* Used in rcu/tree_plugin.h */
830e6acc8a1caf Peter Zijlstra  2021-08-15 @231  static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock)
531ae4b06a737e Thomas Gleixner 2021-08-15  232  {
531ae4b06a737e Thomas Gleixner 2021-08-15  233  	return NULL;
531ae4b06a737e Thomas Gleixner 2021-08-15  234  }
531ae4b06a737e Thomas Gleixner 2021-08-15  235  #endif  /* !CONFIG_RT_MUTEXES */
531ae4b06a737e Thomas Gleixner 2021-08-15  236  

:::::: The code at line 231 was first introduced by commit
:::::: 830e6acc8a1cafe153a0d88f9b2455965b396131 locking/rtmutex: Split out the inner parts of 'struct rtmutex'

:::::: TO: Peter Zijlstra <peterz@infradead.org>
:::::: CC: Ingo Molnar <mingo@kernel.org>

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