[ardb:x86-efistub-cleanup 6/6] drivers/firmware/efi/libstub/x86-stub.c:721:35: sparse: sparse: cast truncates bits from constant value (fffff becomes ffff)

[ardb:x86-efistub-cleanup 6/6] drivers/firmware/efi/libstub/x86-stub.c:721:35: sparse: sparse: cast truncates bits from constant value (fffff becomes ffff)

[kernel test robot]

Hi Ard,

First bad commit (maybe != root cause):

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git x86-efistub-cleanup
head:   31f2f213bc1b8f5975bdc5c56fcd72cd6a8faf8a
commit: ee9e4c5ff43781c5490c88f74767d37b34fe9806 [6/6] x86: efistub: Avoid legacy decompressor when doing EFI boot
config: x86_64-randconfig-s022 (https://download.01.org/0day-ci/archive/20230425/202304251112.lAwJVRGf-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/commit/?id=ee9e4c5ff43781c5490c88f74767d37b34fe9806
        git remote add ardb git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git
        git fetch --no-tags ardb x86-efistub-cleanup
        git checkout ee9e4c5ff43781c5490c88f74767d37b34fe9806
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/firmware/efi/libstub/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304251112.lAwJVRGf-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/firmware/efi/libstub/x86-stub.c:721:35: sparse: sparse: cast truncates bits from constant value (fffff becomes ffff)
   drivers/firmware/efi/libstub/x86-stub.c:722:35: sparse: sparse: cast truncates bits from constant value (fffff becomes ffff)
   drivers/firmware/efi/libstub/x86-stub.c:723:35: sparse: sparse: cast truncates bits from constant value (fffff becomes ffff)

vim +721 drivers/firmware/efi/libstub/x86-stub.c

cb112503d30143 Ard Biesheuvel 2023-04-24  719  
cb112503d30143 Ard Biesheuvel 2023-04-24  720  static const struct desc_struct gdt[] = {
cb112503d30143 Ard Biesheuvel 2023-04-24 @721  	[GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
cb112503d30143 Ard Biesheuvel 2023-04-24  722  	[GDT_ENTRY_KERNEL_CS]   = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
cb112503d30143 Ard Biesheuvel 2023-04-24  723  	[GDT_ENTRY_KERNEL_DS]   = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
cb112503d30143 Ard Biesheuvel 2023-04-24  724  };
cb112503d30143 Ard Biesheuvel 2023-04-24  725  

:::::: The code at line 721 was first introduced by commit
:::::: cb112503d301433d95343a7a2081c5d617f63973 x86: efistub: Perform 4/5 level paging switch from the stub

:::::: TO: Ard Biesheuvel <ardb@kernel.org>
:::::: CC: Ard Biesheuvel <ardb@kernel.org>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests