fs/seq_file.c:938:9: sparse: struct list_head [noderef] __rcu *

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

:::::: 
:::::: Manual check reason: "low confidence static check warning: fs/seq_file.c:938:9: sparse:    struct list_head [noderef] __rcu *"
:::::: 

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
CC: linux-kernel@vger.kernel.org
TO: David Howells <dhowells@redhat.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   4df7c5fde316820286dfa6d203a1005d7fbe007d
commit: ad25f5cb39872ca14bcbe00816ae65c22fe04b89 rxrpc: Fix locking issue
date:   1 year, 7 months ago
:::::: branch date: 3 hours ago
:::::: commit date: 1 year, 7 months ago
config: x86_64-alldefconfig (https://download.01.org/0day-ci/archive/20231209/202312090332.zHaDRvAI-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/20231209/202312090332.zHaDRvAI-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/r/202312090332.zHaDRvAI-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
   fs/seq_file.c:938:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
>> fs/seq_file.c:938:9: sparse:    struct list_head [noderef] __rcu *
>> fs/seq_file.c:938:9: sparse:    struct list_head *
   fs/seq_file.c:938:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
>> fs/seq_file.c:938:9: sparse:    struct list_head [noderef] __rcu *
>> fs/seq_file.c:938:9: sparse:    struct list_head *
>> fs/seq_file.c:960:12: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct list_head *lh @@     got struct list_head [noderef] __rcu * @@
   fs/seq_file.c:960:12: sparse:     expected struct list_head *lh
   fs/seq_file.c:960:12: sparse:     got struct list_head [noderef] __rcu *
   fs/seq_file.c:1087:24: sparse: sparse: incompatible types in comparison expression (different address spaces):
   fs/seq_file.c:1087:24: sparse:    struct hlist_node [noderef] __rcu *
   fs/seq_file.c:1087:24: sparse:    struct hlist_node *
   fs/seq_file.c:1089:24: sparse: sparse: incompatible types in comparison expression (different address spaces):
   fs/seq_file.c:1089:24: sparse:    struct hlist_node [noderef] __rcu *
   fs/seq_file.c:1089:24: sparse:    struct hlist_node *

vim +938 fs/seq_file.c

66655de6d132b7 Li Zefan      2010-02-08  933  
ad25f5cb39872c David Howells 2022-05-21  934  struct list_head *seq_list_start_rcu(struct list_head *head, loff_t pos)
ad25f5cb39872c David Howells 2022-05-21  935  {
ad25f5cb39872c David Howells 2022-05-21  936  	struct list_head *lh;
ad25f5cb39872c David Howells 2022-05-21  937  
ad25f5cb39872c David Howells 2022-05-21 @938  	list_for_each_rcu(lh, head)
ad25f5cb39872c David Howells 2022-05-21  939  		if (pos-- == 0)
ad25f5cb39872c David Howells 2022-05-21  940  			return lh;
ad25f5cb39872c David Howells 2022-05-21  941  
ad25f5cb39872c David Howells 2022-05-21  942  	return NULL;
ad25f5cb39872c David Howells 2022-05-21  943  }
ad25f5cb39872c David Howells 2022-05-21  944  EXPORT_SYMBOL(seq_list_start_rcu);
ad25f5cb39872c David Howells 2022-05-21  945  
ad25f5cb39872c David Howells 2022-05-21  946  struct list_head *seq_list_start_head_rcu(struct list_head *head, loff_t pos)
ad25f5cb39872c David Howells 2022-05-21  947  {
ad25f5cb39872c David Howells 2022-05-21  948  	if (!pos)
ad25f5cb39872c David Howells 2022-05-21  949  		return head;
ad25f5cb39872c David Howells 2022-05-21  950  
ad25f5cb39872c David Howells 2022-05-21  951  	return seq_list_start_rcu(head, pos - 1);
ad25f5cb39872c David Howells 2022-05-21  952  }
ad25f5cb39872c David Howells 2022-05-21  953  EXPORT_SYMBOL(seq_list_start_head_rcu);
ad25f5cb39872c David Howells 2022-05-21  954  
ad25f5cb39872c David Howells 2022-05-21  955  struct list_head *seq_list_next_rcu(void *v, struct list_head *head,
ad25f5cb39872c David Howells 2022-05-21  956  				    loff_t *ppos)
ad25f5cb39872c David Howells 2022-05-21  957  {
ad25f5cb39872c David Howells 2022-05-21  958  	struct list_head *lh;
ad25f5cb39872c David Howells 2022-05-21  959  
ad25f5cb39872c David Howells 2022-05-21 @960  	lh = list_next_rcu((struct list_head *)v);
ad25f5cb39872c David Howells 2022-05-21  961  	++*ppos;
ad25f5cb39872c David Howells 2022-05-21  962  	return lh == head ? NULL : lh;
ad25f5cb39872c David Howells 2022-05-21  963  }
ad25f5cb39872c David Howells 2022-05-21  964  EXPORT_SYMBOL(seq_list_next_rcu);
ad25f5cb39872c David Howells 2022-05-21  965  

-- 
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