Re: [PATCH V4 4/8] mm/slab: abstract slabobj_ext access via new slab_obj_ext() helper

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

Hi Harry,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Harry-Yoo/mm-slab-use-unsigned-long-for-orig_size-to-ensure-proper-metadata-align/20251222-191144
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251222110843.980347-5-harry.yoo%40oracle.com
patch subject: [PATCH V4 4/8] mm/slab: abstract slabobj_ext access via new slab_obj_ext() helper
config: parisc-randconfig-002-20251223 (https://download.01.org/0day-ci/archive/20251223/202512230727.ktAJv4eA-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251223/202512230727.ktAJv4eA-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/202512230727.ktAJv4eA-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from include/asm-generic/bug.h:5,
                    from arch/parisc/include/asm/bug.h:97,
                    from include/linux/bug.h:5,
                    from include/linux/mmdebug.h:5,
                    from include/linux/mm.h:6,
                    from mm/slub.c:13:
   mm/slub.c: In function 'mark_objexts_empty':
>> mm/slub.c:2056:36: error: incompatible type for argument 1 of 'is_codetag_empty'
      if (unlikely(is_codetag_empty(ext->ref)))
                                    ~~~^~~~~
   include/linux/compiler.h:77:42: note: in definition of macro 'unlikely'
    # define unlikely(x) __builtin_expect(!!(x), 0)
                                             ^
   In file included from include/linux/workqueue.h:9,
                    from include/linux/mm_types.h:19,
                    from include/linux/mmzone.h:22,
                    from include/linux/gfp.h:7,
                    from include/linux/mm.h:7,
                    from mm/slub.c:13:
   include/linux/alloc_tag.h:52:56: note: expected 'union codetag_ref *' but argument is of type 'union codetag_ref'
    static inline bool is_codetag_empty(union codetag_ref *ref)
                                        ~~~~~~~~~~~~~~~~~~~^~~

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for CAN_DEV
   Depends on [n]: NETDEVICES [=n] && CAN [=y]
   Selected by [y]:
   - CAN [=y] && NET [=y]


vim +/is_codetag_empty +2056 mm/slub.c

  2042	
  2043	static inline void mark_objexts_empty(struct slabobj_ext *obj_exts)
  2044	{
  2045		unsigned long slab_exts;
  2046		struct slab *obj_exts_slab;
  2047	
  2048		obj_exts_slab = virt_to_slab(obj_exts);
  2049		slab_exts = slab_obj_exts(obj_exts_slab);
  2050		if (slab_exts) {
  2051			unsigned int offs = obj_to_index(obj_exts_slab->slab_cache,
  2052							 obj_exts_slab, obj_exts);
  2053			struct slabobj_ext *ext = slab_obj_ext(obj_exts_slab,
  2054							       slab_exts, offs);
  2055	
> 2056			if (unlikely(is_codetag_empty(ext->ref)))
  2057				return;
  2058	
  2059			/* codetag should be NULL here */
  2060			WARN_ON(ext->ref.ct);
  2061			set_codetag_empty(&ext->ref);
  2062		}
  2063	}
  2064	

-- 
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https://github.com/intel/lkp-tests/wiki