kernel/cgroup/dmem.c:466:9: sparse: sparse: incompatible types in comparison expression (different address spaces):

kernel/cgroup/dmem.c:466:9: sparse: sparse: incompatible types in comparison expression (different address spaces):

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   d358e5254674b70f34c847715ca509e46eb81e6f
commit: b168ed458ddecc176f3b9a1f4bcd83d7a4541c14 kernel/cgroup: Add "dmem" memory accounting cgroup
date:   11 months ago
config: i386-randconfig-062-20251211 (https://download.01.org/0day-ci/archive/20251211/202512111220.cuUZGIQi-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251211/202512111220.cuUZGIQi-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/202512111220.cuUZGIQi-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> kernel/cgroup/dmem.c:466:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/cgroup/dmem.c:466:9: sparse:    struct list_head [noderef] __rcu *
   kernel/cgroup/dmem.c:466:9: sparse:    struct list_head *
>> kernel/cgroup/dmem.c:466:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/cgroup/dmem.c:466:9: sparse:    struct list_head [noderef] __rcu *
   kernel/cgroup/dmem.c:466:9: sparse:    struct list_head *

vim +466 kernel/cgroup/dmem.c

   447	
   448	/**
   449	 * dmem_cgroup_unregister_region() - Unregister a previously registered region.
   450	 * @region: The region to unregister.
   451	 *
   452	 * This function undoes dmem_cgroup_register_region.
   453	 */
   454	void dmem_cgroup_unregister_region(struct dmem_cgroup_region *region)
   455	{
   456		struct list_head *entry;
   457	
   458		if (!region)
   459			return;
   460	
   461		spin_lock(&dmemcg_lock);
   462	
   463		/* Remove from global region list */
   464		list_del_rcu(&region->region_node);
   465	
 > 466		list_for_each_rcu(entry, &region->pools) {
   467			struct dmem_cgroup_pool_state *pool =
   468				container_of(entry, typeof(*pool), region_node);
   469	
   470			list_del_rcu(&pool->css_node);
   471		}
   472	
   473		/*
   474		 * Ensure any RCU based lookups fail. Additionally,
   475		 * no new pools should be added to the dead region
   476		 * by get_cg_pool_unlocked.
   477		 */
   478		region->unregistered = true;
   479		spin_unlock(&dmemcg_lock);
   480	
   481		kref_put(&region->ref, dmemcg_free_region);
   482	}
   483	EXPORT_SYMBOL_GPL(dmem_cgroup_unregister_region);
   484	

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