[ammarfaizi2-block:paulmck/linux-rcu/dev 18/18] mm/slab_common.c:336:23: sparse: sparse: restricted slab_flags_t degrades to integer

[kernel test robot]

tree:   https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/dev
head:   e6e0d15aa1c5117dda15eb266e8b862627af7608
commit: e6e0d15aa1c5117dda15eb266e8b862627af7608 [18/18] mm: Check for SLAB_TYPESAFE_BY_RCU and __GFP_ZERO slab creation
config: m68k-randconfig-s032-20220206 (https://download.01.org/0day-ci/archive/20220207/202202070951.I9Vhb0aQ-lkp@xxxxxxxxx/config)
compiler: m68k-linux-gcc (GCC) 11.2.0
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: v0.6.4-dirty
        # https://github.com/ammarfaizi2/linux-block/commit/e6e0d15aa1c5117dda15eb266e8b862627af7608
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/dev
        git checkout e6e0d15aa1c5117dda15eb266e8b862627af7608
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=m68k SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>


sparse warnings: (new ones prefixed by >>)
>> mm/slab_common.c:336:23: sparse: sparse: restricted slab_flags_t degrades to integer
>> mm/slab_common.c:336:46: sparse: sparse: restricted gfp_t degrades to integer
   mm/slab_common.c:336:14: sparse: sparse: restricted slab_flags_t degrades to integer
   mm/slab_common.c:336:63: sparse: sparse: restricted slab_flags_t degrades to integer
   mm/slab_common.c:336:86: sparse: sparse: restricted gfp_t degrades to integer

vim +336 mm/slab_common.c

   321	
   322		mutex_lock(&slab_mutex);
   323	
   324		err = kmem_cache_sanity_check(name, size);
   325		if (err) {
   326			goto out_unlock;
   327		}
   328	
   329		/* Refuse requests with allocator specific flags */
   330		if (flags & ~SLAB_FLAGS_PERMITTED) {
   331			err = -EINVAL;
   332			goto out_unlock;
   333		}
   334	
   335		/* References to typesafe memory survives free/alloc. */
 > 336		if ((flags & (SLAB_TYPESAFE_BY_RCU | __GFP_ZERO)) == (SLAB_TYPESAFE_BY_RCU | __GFP_ZERO)) {
   337			err = -EINVAL;
   338			goto out_unlock;
   339		}
   340	
   341		/*
   342		 * Some allocators will constraint the set of valid flags to a subset
   343		 * of all flags. We expect them to define CACHE_CREATE_MASK in this
   344		 * case, and we'll just provide them with a sanitized version of the
   345		 * passed flags.
   346		 */
   347		flags &= CACHE_CREATE_MASK;
   348	
   349		/* Fail closed on bad usersize of useroffset values. */
   350		if (WARN_ON(!usersize && useroffset) ||
   351		    WARN_ON(size < usersize || size - usersize < useroffset))
   352			usersize = useroffset = 0;
   353	
   354		if (!usersize)
   355			s = __kmem_cache_alias(name, size, align, flags, ctor);
   356		if (s)
   357			goto out_unlock;
   358	
   359		cache_name = kstrdup_const(name, GFP_KERNEL);
   360		if (!cache_name) {
   361			err = -ENOMEM;
   362			goto out_unlock;
   363		}
   364	
   365		s = create_cache(cache_name, size,
   366				 calculate_alignment(flags, align, size),
   367				 flags, useroffset, usersize, ctor, NULL);
   368		if (IS_ERR(s)) {
   369			err = PTR_ERR(s);
   370			kfree_const(cache_name);
   371		}
   372	
   373	out_unlock:
   374		mutex_unlock(&slab_mutex);
   375	
   376		if (err) {
   377			if (flags & SLAB_PANIC)
   378				panic("%s: Failed to create slab '%s'. Error %d\n",
   379					__func__, name, err);
   380			else {
   381				pr_warn("%s(%s) failed with error %d\n",
   382					__func__, name, err);
   383				dump_stack();
   384			}
   385			return NULL;
   386		}
   387		return s;
   388	}
   389	EXPORT_SYMBOL(kmem_cache_create_usercopy);
   390	

---
0-DAY CI Kernel Test Service, Intel Corporation
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