tree: https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git sev-es-client-v5.8-rc4 head: 7ee5e0ddab7fa6efbf0937f175a5688a375d55b8 commit: 0aaca116c3bfa95d26f0e7ad738cd92927eb899e [30/75] x86/head/64: Install boot GDT config: x86_64-randconfig-s021-20200709 (attached as .config) compiler: gcc-9 (Debian 9.3.0-14) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.2-37-gc9676a3b-dirty git checkout 0aaca116c3bfa95d26f0e7ad738cd92927eb899e # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64 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 >>) arch/x86/kernel/head64.c:70:43: sparse: sparse: cast truncates bits from constant value (fffff becomes ffff) arch/x86/kernel/head64.c:71:43: sparse: sparse: cast truncates bits from constant value (fffff becomes ffff) vim +69 arch/x86/kernel/head64.c 63 64 /* 65 * GDT used before %gs is set up and the kernel can use gdt_page. Needed for 66 * early exception handling. 67 */ 68 struct desc_struct boot_gdt[GDT_ENTRIES] = { 70 [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff), 71 [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff), 72 }; 73 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org