[intel-lts:6.12/linux 20/20] include/uapi/linux/const.h:20:25: warning: conversion from 'long long unsigned int' to 'size_t' {aka 'const unsigned int'} changes value from '4294967296' to '0'

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/intel/linux-intel-lts.git 6.12/linux
head:   c4c69642b7fda4d0c69a9fe66728ac8b398aca5f
commit: d0c16cc743c4bb02f70ff97b1dcb5f3d6e77f7ad [20/20] Revert "drm/i915: Depend on !PREEMPT_RT."
config: i386-allmodconfig (https://download.01.org/0day-ci/archive/20250412/202504122252.A6R8qTwj-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250412/202504122252.A6R8qTwj-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202504122252.A6R8qTwj-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/vdso/const.h:5,
                    from include/linux/const.h:4,
                    from include/uapi/linux/kernel.h:6,
                    from include/linux/cache.h:5,
                    from include/linux/slab.h:15,
                    from include/linux/io-mapping.h:10,
                    from drivers/gpu/drm/i915/gt/intel_gtt.h:19,
                    from drivers/gpu/drm/i915/gt/iov/intel_iov_ggtt.h:9,
                    from drivers/gpu/drm/i915/gt/iov/intel_iov_ggtt.c:7:
   drivers/gpu/drm/i915/gt/iov/selftests/selftest_mock_iov_ggtt.c: In function 'mock_ggtt_shadow_restore_new_vfid':
>> include/uapi/linux/const.h:20:25: warning: conversion from 'long long unsigned int' to 'size_t' {aka 'const unsigned int'} changes value from '4294967296' to '0' [-Woverflow]
      20 | #define __AC(X,Y)       (X##Y)
         |                         ^
   include/uapi/linux/const.h:21:25: note: in expansion of macro '__AC'
      21 | #define _AC(X,Y)        __AC(X,Y)
         |                         ^~~~
   include/linux/sizes.h:46:41: note: in expansion of macro '_AC'
      46 | #define SZ_4G                           _AC(0x100000000, ULL)
         |                                         ^~~
   drivers/gpu/drm/i915/gt/iov/selftests/selftest_mock_iov_ggtt.c:318:34: note: in expansion of macro 'SZ_4G'
     318 |         const size_t ggtt_size = SZ_4G;
         |                                  ^~~~~


vim +20 include/uapi/linux/const.h

9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02   6  
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02   7  /* Some constant macros are used in both assembler and
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02   8   * C code.  Therefore we cannot annotate them always with
6df95fd7ad9a84 include/linux/const.h      Randy Dunlap        2007-05-08   9   * 'UL' and other type specifiers unilaterally.  We
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  10   * use the following macros to deal with this.
74ef649fe847fd include/linux/const.h      Jeremy Fitzhardinge 2008-01-30  11   *
74ef649fe847fd include/linux/const.h      Jeremy Fitzhardinge 2008-01-30  12   * Similarly, _AT() will cast an expression with a type in C, but
74ef649fe847fd include/linux/const.h      Jeremy Fitzhardinge 2008-01-30  13   * leave it unchanged in asm.
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  14   */
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  15  
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  16  #ifdef __ASSEMBLY__
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  17  #define _AC(X,Y)	X
74ef649fe847fd include/linux/const.h      Jeremy Fitzhardinge 2008-01-30  18  #define _AT(T,X)	X
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  19  #else
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02 @20  #define __AC(X,Y)	(X##Y)
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  21  #define _AC(X,Y)	__AC(X,Y)
74ef649fe847fd include/linux/const.h      Jeremy Fitzhardinge 2008-01-30  22  #define _AT(T,X)	((T)(X))
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  23  #endif
9d291e787b2b71 include/asm-x86_64/const.h Vivek Goyal         2007-05-02  24  

:::::: The code at line 20 was first introduced by commit
:::::: 9d291e787b2b71d1b57e5fbb24ba9c70e748ed84 [PATCH] x86-64: Assembly safe page.h and pgtable.h

:::::: TO: Vivek Goyal <vgoyal@in.ibm.com>
:::::: CC: Andi Kleen <andi@basil.nowhere.org>

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