[peterz-queue:locking/core 1/11] kernel/sched/core.o: warning: objtool: migrate_enable()+0x1b2: unreachable instruction

CC: linux-kernel@vger.kernel.org
TO: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
CC: Peter Zijlstra <peterz@infradead.org>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git locking/core
head:   4cf75fd4a2545ca4deea992f929602c9fdbe8058
commit: 9d0df37797453f168afdb2e6fd0353c73718ae9a [1/11] sched: Trigger warning if ->migration_disabled counter underflows.
config: x86_64-randconfig-a015-20211205 (https://download.01.org/0day-ci/archive/20211206/202112061752.t4VbQG3p-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 5f1d1854eb1450d352663ee732235893c5782237)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?id=9d0df37797453f168afdb2e6fd0353c73718ae9a
        git remote add peterz-queue https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git
        git fetch --no-tags peterz-queue locking/core
        git checkout 9d0df37797453f168afdb2e6fd0353c73718ae9a
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All warnings (new ones prefixed by >>):

   kernel/sched/core.c:3442:6: warning: no previous prototype for function 'sched_set_stop_task' [-Wmissing-prototypes]
   void sched_set_stop_task(int cpu, struct task_struct *stop)
        ^
   kernel/sched/core.c:3442:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void sched_set_stop_task(int cpu, struct task_struct *stop)
   ^
   static 
   kernel/sched/core.c:1660:1: warning: unused function 'uclamp_update_active' [-Wunused-function]
   uclamp_update_active(struct task_struct *p)
   ^
   2 warnings generated.

quoted

kernel/sched/core.o: warning: objtool: migrate_enable()+0x1b2: unreachable instruction

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