[kbuild-all] arch/arm64/include/asm/cmpxchg.h:88:1: sparse: sparse: cast truncates bits from constant value (ffff becomes ff)

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 0da0a8a0a0e1845f495431c3d8d733d2bbf9e9e5 commit: 4beba9486abd2f86d125271d6946f7c38ed0fe77 mm: Add PG_arch_2 page flag date: 5 months ago config: arm64-randconfig-s031-20210117 (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.3-208-g46a52ca4-dirty # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 4beba9486abd2f86d125271d6946f7c38ed0fe77 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; "sparse warnings: (new ones prefixed by >>)" mm/migrate.c: note: in included file (through arch/arm64/include/asm/atomic.h, include/linux/atomic.h, include/asm-generic/bitops/atomic.h, ...): -- mm/memory.c:829:17: sparse: sparse: context imbalance in 'copy_pte_range' - different lock contexts for basic block mm/memory.c:1450:16: sparse: sparse: context imbalance in '__get_locked_pte' - different lock contexts for basic block mm/memory.c:1499:9: sparse: sparse: context imbalance in 'insert_page' - different lock contexts for basic block mm/memory.c:2001:17: sparse: sparse: context imbalance in 'remap_pte_range' - different lock contexts for basic block mm/memory.c:2242:17: sparse: sparse: context imbalance in 'apply_to_pte_range' - unexpected unlock mm/memory.c:2491:17: sparse: sparse: context imbalance in 'wp_page_copy' - unexpected unlock mm/memory.c: note: in included file (through arch/arm64/include/asm/atomic.h, include/linux/atomic.h, include/asm-generic/bitops/atomic.h, ...): mm/memory.c:2835:17: sparse: sparse: context imbalance in 'wp_pfn_shared' - unexpected unlock mm/memory.c:2898:19: sparse: sparse: context imbalance in 'do_wp_page' - different lock contexts for basic block mm/memory.c:3495:19: sparse: sparse: context imbalance in 'pte_alloc_one_map' - different lock contexts for basic block mm/memory.c:3721:17: sparse: sparse: context imbalance in 'finish_fault' - unexpected unlock mm/memory.c:3830:9: sparse: sparse: context imbalance in 'do_fault_around' - unexpected unlock mm/memory.c:4549:12: sparse: sparse: context imbalance in '__follow_pte_pmd' - different lock contexts for basic block mm/memory.c:4635:16: sparse: sparse: context imbalance in 'follow_pte_pmd' - different lock contexts for basic block vim +88 arch/arm64/include/asm/cmpxchg.h 10b663aef1c24794 Catalin Marinas 2012-03-05 84 305d454aaa292be3 Will Deacon 2015-10-08 85 __XCHG_GEN() 305d454aaa292be3 Will Deacon 2015-10-08 86 __XCHG_GEN(_acq) 305d454aaa292be3 Will Deacon 2015-10-08 87 __XCHG_GEN(_rel) 305d454aaa292be3 Will Deacon 2015-10-08 @88 __XCHG_GEN(_mb) 305d454aaa292be3 Will Deacon 2015-10-08 89 :::::: The code at line 88 was first introduced by commit :::::: 305d454aaa292be3a09a9d674e6c35f5b4249a13 arm64: atomics: implement native {relaxed, acquire, release} atomics :::::: TO: Will Deacon <will.deacon(a)arm.com&gt; :::::: CC: Catalin Marinas <catalin.marinas(a)arm.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org