net/netfilter/nf_conncount.c:259:9: sparse: sparse: context imbalance in 'nf_conncount_gc_list' - wrong count at exit

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   4f30a60aa78410496e5ffe632a371c00f0d83a8d
commit: 80591e61a0f7e88deaada69844e4a31280c4a38f kbuild: tell sparse about the $ARCH
date:   9 months ago
config: nios2-randconfig-s031-20200805 (attached as .config)
compiler: nios2-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.2-117-g8c7aee71-dirty
        git checkout 80591e61a0f7e88deaada69844e4a31280c4a38f
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=nios2 

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


sparse warnings: (new ones prefixed by >>)

>> net/netfilter/nf_conncount.c:259:9: sparse: sparse: context imbalance in 'nf_conncount_gc_list' - wrong count at exit
   net/netfilter/nf_conncount.c: note: in included file (through include/linux/mm_types.h, include/linux/mmzone.h, include/linux/gfp.h, ...):
   include/linux/rbtree.h:84:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   include/linux/rbtree.h:84:9: sparse:    struct rb_node [noderef] <asn:4> *
   include/linux/rbtree.h:84:9: sparse:    struct rb_node *

vim +/nf_conncount_gc_list +259 net/netfilter/nf_conncount.c

cb2b36f5a97df7 Yi-Hung Wei       2018-07-02  219  
2f971a8f425545 Pablo Neira Ayuso 2018-12-28  220  /* Return true if the list is empty. Must be called with BH disabled. */
5c789e131cbb99 Yi-Hung Wei       2018-07-02  221  bool nf_conncount_gc_list(struct net *net,
cb2b36f5a97df7 Yi-Hung Wei       2018-07-02  222  			  struct nf_conncount_list *list)
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  223  {
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  224  	const struct nf_conntrack_tuple_hash *found;
cb2b36f5a97df7 Yi-Hung Wei       2018-07-02  225  	struct nf_conncount_tuple *conn, *conn_n;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  226  	struct nf_conn *found_ct;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  227  	unsigned int collected = 0;
3c5cdb17c3be76 Taehee Yoo        2018-11-05  228  	bool ret = false;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  229  
2f971a8f425545 Pablo Neira Ayuso 2018-12-28  230  	/* don't bother if other cpu is already doing GC */
2f971a8f425545 Pablo Neira Ayuso 2018-12-28  231  	if (!spin_trylock(&list->list_lock))
2f971a8f425545 Pablo Neira Ayuso 2018-12-28  232  		return false;
2f971a8f425545 Pablo Neira Ayuso 2018-12-28  233  
cb2b36f5a97df7 Yi-Hung Wei       2018-07-02  234  	list_for_each_entry_safe(conn, conn_n, &list->head, node) {
c80f10bc973af2 Pablo Neira Ayuso 2018-12-28  235  		found = find_or_evict(net, list, conn);
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  236  		if (IS_ERR(found)) {
c80f10bc973af2 Pablo Neira Ayuso 2018-12-28  237  			if (PTR_ERR(found) == -ENOENT)
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  238  				collected++;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  239  			continue;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  240  		}
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  241  
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  242  		found_ct = nf_ct_tuplehash_to_ctrack(found);
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  243  		if (already_closed(found_ct)) {
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  244  			/*
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  245  			 * we do not care about connections which are
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  246  			 * closed already -> ditch it
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  247  			 */
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  248  			nf_ct_put(found_ct);
c80f10bc973af2 Pablo Neira Ayuso 2018-12-28  249  			conn_free(list, conn);
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  250  			collected++;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  251  			continue;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  252  		}
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  253  
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  254  		nf_ct_put(found_ct);
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  255  		if (collected > CONNCOUNT_GC_MAX_NODES)
2f971a8f425545 Pablo Neira Ayuso 2018-12-28  256  			break;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  257  	}
3c5cdb17c3be76 Taehee Yoo        2018-11-05  258  
c80f10bc973af2 Pablo Neira Ayuso 2018-12-28 @259  	if (!list->count)
3c5cdb17c3be76 Taehee Yoo        2018-11-05  260  		ret = true;
2f971a8f425545 Pablo Neira Ayuso 2018-12-28  261  	spin_unlock(&list->list_lock);
3c5cdb17c3be76 Taehee Yoo        2018-11-05  262  
3c5cdb17c3be76 Taehee Yoo        2018-11-05  263  	return ret;
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  264  }
976afca1ceba53 Yi-Hung Wei       2018-07-02  265  EXPORT_SYMBOL_GPL(nf_conncount_gc_list);
2a406e8ac7c3e7 Yi-Hung Wei       2018-07-02  266  

:::::: The code at line 259 was first introduced by commit
:::::: c80f10bc973af2ace6b1414724eeff61eaa71837 netfilter: nf_conncount: speculative garbage collection on empty lists

:::::: TO: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
:::::: CC: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

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