Hi Florian, I love your patch! Perhaps something to improve: [auto build test WARNING on nf-next/master] url: https://github.com/0day-ci/linux/commits/Florian-Westphal/netfilter-ctnet... base: https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git master reproduce: # apt-get install sparse # sparse version: v0.6.1-rc1-43-g0ccb3b4-dirty make ARCH=x86_64 allmodconfig make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) net/netfilter/nf_conntrack_netlink.c:521:45: sparse: sparse: incorrect type in argument 2 (different modifiers) @@ expected struct nf_conn *ct @@ got structstruct nf_conn *ct @@ net/netfilter/nf_conntrack_netlink.c:521:45: sparse: expected struct nf_conn *ct net/netfilter/nf_conntrack_netlink.c:521:45: sparse: got struct nf_conn const *ct net/netfilter/nf_conntrack_netlink.c:1694:34: sparse: sparse: incompatible types in comparison expression (different address spaces): net/netfilter/nf_conntrack_netlink.c:1694:34: sparse: struct nf_conntrack_helper [noderef] <asn:4> * net/netfilter/nf_conntrack_netlink.c:1694:34: sparse: struct nf_conntrack_helper * net/netfilter/nf_conntrack_netlink.c:3146:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const * @@ got char [noderechar const * @@ net/netfilter/nf_conntrack_netlink.c:3146:29: sparse: expected char const * net/netfilter/nf_conntrack_netlink.c:3146:29: sparse: got char [noderef] <asn:4> * net/netfilter/nf_conntrack_netlink.c:951:36: sparse: sparse: context imbalance in 'ctnetlink_dump_table' - unexpected unlock include/linux/rcupdate.h:651:9: sparse: sparse: context imbalance in 'ctnetlink_parse_nat_setup' - unexpected unlock vim +520 net/netfilter/nf_conntrack_netlink.c 508 509 /* all these functions access ct->ext. Caller must either hold a reference 510 * on ct or prevent its deletion by holding either the bucket spinlock or 511 * pcpu dying list lock. 512 */ 513 static int ctnetlink_dump_extinfo(struct sk_buff *skb, 514 const struct nf_conn *ct, u32 type) 515 { 516 if (ctnetlink_dump_acct(skb, ct, type) < 0 || 517 ctnetlink_dump_timestamp(skb, ct) < 0 || 518 ctnetlink_dump_helpinfo(skb, ct) < 0 || 519 ctnetlink_dump_labels(skb, ct) < 0 || 521 ctnetlink_dump_ct_synproxy(skb, ct) < 0) 522 return -1; 523 524 return 0; 525 } 526 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation