[kbuild-all] Re: [linux-next:master 1888/2633] kernel/rcu/refscale.c:479:3: warning: variable 'x' is uninitialized when used here

tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: ec85c95b0c90a17413901b018e8ade7b9eae7cad commit: 4b46fcb7f1a6a202e3f77ce377079b4243d1be6f [1888/2633] refscale: Add measurement of clock readout config: riscv-randconfig-r022-20210512 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc) 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 # install riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 4b46fcb7f1a6a202e3f77ce377079b4243d1be6f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): >> kernel/rcu/refscale.c:479:3: warning: variable 'x' is uninitialized when used here [-Wuninitialized] x += ktime_get_real_fast_ns(); ^ kernel/rcu/refscale.c:474:7: note: initialize the variable 'x' to silence this warning u64 x; ^ = 0 kernel/rcu/refscale.c:492:3: warning: variable 'x' is uninitialized when used here [-Wuninitialized] x += ktime_get_real_fast_ns(); ^ kernel/rcu/refscale.c:487:7: note: initialize the variable 'x' to silence this warning u64 x; ^ = 0 2 warnings generated. Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for LOCKDEP Depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT && (FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86) Selected by - DEBUG_LOCK_ALLOC && DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT

vim +/x +479 kernel/rcu/refscale.c 471 472 static void ref_clock_section(const int nloops) 473 { 474 u64 x; 475 int i; 476 477 preempt_disable(); 478 for (i = nloops; i >= 0; i--) { > 479 x += ktime_get_real_fast_ns(); 480 } 481 preempt_enable(); 482 stopopts = x; 483 } 484 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org