[kbuild-all] arch/s390/kernel/perf_cpum_cf_diag.c:787 cf_diag_all_copy() warn: ignoring unreachable code.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: a74e6a014c9d4d4161061f770c9b4f98372ac778 commit: cf6acb8bdb1d829b85a4daa2944bf9e71c93f4b9 s390/cpumf: Add support for complete counter set extraction date: 2 weeks ago config: s390-randconfig-m031-20210311 (attached as .config) compiler: s390-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; smatch warnings: arch/s390/kernel/perf_cpum_cf_diag.c:787 cf_diag_all_copy() warn: ignoring unreachable code. vim +787 arch/s390/kernel/perf_cpum_cf_diag.c 770 771 static int cf_diag_all_copy(unsigned long arg, cpumask_t *mask) 772 { 773 struct s390_ctrset_read __user *ctrset_read; 774 unsigned int cpu, cpus, rc; 775 void __user *uptr; 776 777 ctrset_read = (struct s390_ctrset_read __user *)arg; 778 uptr = ctrset_read->data; 779 for_each_cpu(cpu, mask) { 780 struct cf_diag_csd *csd = per_cpu_ptr(&cf_diag_csd, cpu); 781 struct s390_ctrset_cpudata __user *ctrset_cpudata; 782 783 ctrset_cpudata = uptr; 784 debug_sprintf_event(cf_diag_dbg, 5, "%s cpu %d used %zd\n", 785 __func__, cpu, csd->used); 786 rc = put_user(cpu, &ctrset_cpudata->cpu_nr); 788 rc |= copy_to_user(ctrset_cpudata->data, csd->data, csd->used); 789 if (rc) 790 return -EFAULT; 791 uptr += sizeof(struct s390_ctrset_cpudata) + csd->used; 792 cond_resched(); 793 } 794 cpus = cpumask_weight(mask); 795 if (put_user(cpus, &ctrset_read->no_cpus)) 796 return -EFAULT; 797 debug_sprintf_event(cf_diag_dbg, 5, "%s copied %ld\n", 798 __func__, uptr - (void __user *)ctrset_read->data); 799 return 0; 800 } 801 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org