tree: git://git.infradead.org/users/hch/misc.git alloc_vm_area head: d574728eedb41cee38600f7f2199852e9018a50a commit: 14e6831d7306306425df24459348bda79c30bb06 [5/7] xen/xenbus: open code alloc_vm_area in xenbus_map_ring_pv config: x86_64-randconfig-a006-20200917 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 1321160a26e7e489baf9b10d6de90a342f898960) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu git checkout 14e6831d7306306425df24459348bda79c30bb06 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): if (apply_to_page_range(&init_mm, (unsigned long)area->addr, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/xen/xenbus/xenbus_client.c:734:7: note: uninitialized use occurs here if (!leaked) ^~~~~~ drivers/xen/xenbus/xenbus_client.c:710:2: note: remove the 'if' if its condition is always false if (apply_to_page_range(&init_mm, (unsigned long)area->addr, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/xen/xenbus/xenbus_client.c:704:13: note: initialize the variable 'leaked' to silence this warning bool leaked; ^ = 0 1 warning generated. git remote add hch-misc git://git.infradead.org/users/hch/misc.git git fetch --no-tags hch-misc alloc_vm_area git checkout 14e6831d7306306425df24459348bda79c30bb06 vim +710 drivers/xen/xenbus/xenbus_client.c 694 695 static int xenbus_map_ring_pv(struct xenbus_device *dev, 696 struct map_ring_valloc *info, 697 grant_ref_t *gnt_refs, 698 unsigned int nr_grefs, 699 void **vaddr) 700 { 701 struct xenbus_map_node *node = info->node; 702 struct vm_struct *area; 703 int err = -ENOMEM; 704 bool leaked; 705 706 area = get_vm_area_caller(XEN_PAGE_SIZE * nr_grefs, VM_IOREMAP, 707 __builtin_return_address(0)); 708 if (!area) 709 return -ENOMEM; 711 XEN_PAGE_SIZE * nr_grefs, map_ring_apply, 712 &info->phys_addrs)) 713 goto failed; 714 715 err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles, 716 info, GNTMAP_host_map | GNTMAP_contains_pte, 717 &leaked); 718 if (err) 719 goto failed; 720 721 node->nr_handles = nr_grefs; 722 node->pv.area = area; 723 724 spin_lock(&xenbus_valloc_lock); 725 list_add(&node->next, &xenbus_valloc_pages); 726 spin_unlock(&xenbus_valloc_lock); 727 728 *vaddr = area->addr; 729 info->node = NULL; 730 731 return 0; 732 733 failed: 734 if (!leaked) 735 free_vm_area(area); 736 else 737 pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs); 738 739 return err; 740 } 741 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org