tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2020.06.17a head: d3779e78b9848a707448dbb4a0cb6c4bb651fe9c commit: 59a5d883f2ccdce1700862b5983cfd3473630aea [35/38] EXP sched: Alleged fix for v5.8 merge-window scheduler issue config: x86_64-randconfig-m001-20200621 (attached as .config) compiler: gcc-9 (Debian 9.3.0-13) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; smatch warnings: kernel/sched/core.c:2650 try_to_wake_up() error: uninitialized symbol 'cpu'. # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/com... git remote add rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git git remote update rcu git checkout 59a5d883f2ccdce1700862b5983cfd3473630aea vim +/cpu +2650 kernel/sched/core.c ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 2644 b5179ac70de85e kernel/sched/core.c Peter Zijlstra 2016-05-11 2645 ttwu_queue(p, cpu, wake_flags); aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 2646 unlock: 013fdb8086acaa kernel/sched.c Peter Zijlstra 2011-04-05 2647 raw_spin_unlock_irqrestore(&p->pi_lock, flags); aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 2648 out: aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 2649 if (success) aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 @2650 ttwu_stat(p, cpu, wake_flags); ^^^ This can be uninitialized on a couple "goto unlock;" paths. Lines 2581 and 2622. The KASan tool will warn about this at run time as well. I'm not sure why the build bot doesn't include the whole function for this bug report... e3d85487fba422 kernel/sched/core.c Peter Zijlstra 2019-07-10 2651 preempt_enable(); ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 2652 ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 2653 return success; ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 2654 } --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org