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 config: i386-randconfig-g004-201941 (attached as .config) compiler: gcc-7 (Debian 7.4.0-13) 7.4.0 reproduce: # save the attached .config to linux build tree make ARCH=i386 If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from include/linux/init.h:5:0, from net/netfilter/nf_conntrack_netlink.c:18: net/netfilter/nf_conntrack_netlink.c: In function 'ctnetlink_dump_extinfo': net/netfilter/nf_conntrack_netlink.c:520:37: warning: passing argument 2 of 'ctnetlink_dump_ct_seq_adj' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] ctnetlink_dump_ct_seq_adj(skb, ct) < 0 || ^ include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~ if (ctnetlink_dump_acct(skb, ct, type) < 0 || ^~ net/netfilter/nf_conntrack_netlink.c:438:12: note: expected 'struct nf_conn *' but argument is of type 'const struct nf_conn *' static int ctnetlink_dump_ct_seq_adj(struct sk_buff *skb, struct nf_conn *ct) ^~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/init.h:5:0, from net/netfilter/nf_conntrack_netlink.c:18: net/netfilter/nf_conntrack_netlink.c:521:38: warning: passing argument 2 of 'ctnetlink_dump_ct_synproxy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] ctnetlink_dump_ct_synproxy(skb, ct) < 0) ^ include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~ if (ctnetlink_dump_acct(skb, ct, type) < 0 || ^~ net/netfilter/nf_conntrack_netlink.c:462:12: note: expected 'struct nf_conn *' but argument is of type 'const struct nf_conn *' static int ctnetlink_dump_ct_synproxy(struct sk_buff *skb, struct nf_conn *ct) ^~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/init.h:5:0, from net/netfilter/nf_conntrack_netlink.c:18: net/netfilter/nf_conntrack_netlink.c:520:37: warning: passing argument 2 of 'ctnetlink_dump_ct_seq_adj' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] ctnetlink_dump_ct_seq_adj(skb, ct) < 0 || ^ include/linux/compiler.h:58:61: note: in definition of macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~ if (ctnetlink_dump_acct(skb, ct, type) < 0 || ^~ net/netfilter/nf_conntrack_netlink.c:438:12: note: expected 'struct nf_conn *' but argument is of type 'const struct nf_conn *' static int ctnetlink_dump_ct_seq_adj(struct sk_buff *skb, struct nf_conn *ct) ^~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/init.h:5:0, from net/netfilter/nf_conntrack_netlink.c:18: net/netfilter/nf_conntrack_netlink.c:521:38: warning: passing argument 2 of 'ctnetlink_dump_ct_synproxy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] ctnetlink_dump_ct_synproxy(skb, ct) < 0) ^ include/linux/compiler.h:58:61: note: in definition of macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~ if (ctnetlink_dump_acct(skb, ct, type) < 0 || ^~ net/netfilter/nf_conntrack_netlink.c:462:12: note: expected 'struct nf_conn *' but argument is of type 'const struct nf_conn *' static int ctnetlink_dump_ct_synproxy(struct sk_buff *skb, struct nf_conn *ct) ^~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/init.h:5:0, from net/netfilter/nf_conntrack_netlink.c:18: net/netfilter/nf_conntrack_netlink.c:520:37: warning: passing argument 2 of 'ctnetlink_dump_ct_seq_adj' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] ctnetlink_dump_ct_seq_adj(skb, ct) < 0 || ^ include/linux/compiler.h:69:3: note: in definition of macro '__trace_if_value' (cond) ? \ ^~~~ include/linux/compiler.h:56:28: note: in expansion of macro '__trace_if_var' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~ if (ctnetlink_dump_acct(skb, ct, type) < 0 || ^~ net/netfilter/nf_conntrack_netlink.c:438:12: note: expected 'struct nf_conn *' but argument is of type 'const struct nf_conn *' static int ctnetlink_dump_ct_seq_adj(struct sk_buff *skb, struct nf_conn *ct) ^~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/init.h:5:0, from net/netfilter/nf_conntrack_netlink.c:18: net/netfilter/nf_conntrack_netlink.c:521:38: warning: passing argument 2 of 'ctnetlink_dump_ct_synproxy' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] ctnetlink_dump_ct_synproxy(skb, ct) < 0) ^ include/linux/compiler.h:69:3: note: in definition of macro '__trace_if_value' (cond) ? \ ^~~~ include/linux/compiler.h:56:28: note: in expansion of macro '__trace_if_var' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~ if (ctnetlink_dump_acct(skb, ct, type) < 0 || ^~ net/netfilter/nf_conntrack_netlink.c:462:12: note: expected 'struct nf_conn *' but argument is of type 'const struct nf_conn *' static int ctnetlink_dump_ct_synproxy(struct sk_buff *skb, struct nf_conn *ct) ^~~~~~~~~~~~~~~~~~~~~~~~~~ net/netfilter/nf_conntrack_netlink.c: In function 'ctnetlink_dump_info': net/netfilter/nf_conntrack_netlink.c:542:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ Cyclomatic Complexity 5 include/linux/compiler.h:__read_once_size Cyclomatic Complexity 5 include/linux/compiler.h:__write_once_size Cyclomatic Complexity 1 include/linux/kasan-checks.h:kasan_check_read Cyclomatic Complexity 1 include/linux/kasan-checks.h:kasan_check_write Cyclomatic Complexity 4 arch/x86/include/asm/bitops.h:arch_set_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:arch___set_bit Cyclomatic Complexity 4 arch/x86/include/asm/bitops.h:arch_clear_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:constant_test_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:variable_test_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:fls Cyclomatic Complexity 1 include/asm-generic/bitops-instrumented.h:set_bit Cyclomatic Complexity 1 include/asm-generic/bitops-instrumented.h:__set_bit Cyclomatic Complexity 1 include/asm-generic/bitops-instrumented.h:clear_bit Cyclomatic Complexity 1 include/uapi/linux/byteorder/little_endian.h:__le32_to_cpup Cyclomatic Complexity 1 include/linux/log2.h:__ilog2_u32 Cyclomatic Complexity 2 arch/x86/include/asm/jump_label.h:arch_static_branch_jump Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:arch_atomic_read Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:arch_atomic_inc Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:arch_atomic_dec_and_test Cyclomatic Complexity 3 arch/x86/include/asm/atomic.h:arch_atomic_try_cmpxchg Cyclomatic Complexity 1 arch/x86/include/asm/atomic64_32.h:arch_atomic64_xchg Cyclomatic Complexity 1 arch/x86/include/asm/atomic64_32.h:arch_atomic64_read Cyclomatic Complexity 1 include/asm-generic/atomic-instrumented.h:atomic_read Cyclomatic Complexity 1 include/asm-generic/atomic-instrumented.h:atomic_inc Cyclomatic Complexity 1 include/asm-generic/atomic-instrumented.h:atomic_try_cmpxchg Cyclomatic Complexity 1 include/asm-generic/atomic-instrumented.h:atomic_dec_and_test Cyclomatic Complexity 1 include/asm-generic/atomic-instrumented.h:atomic64_read Cyclomatic Complexity 1 include/asm-generic/atomic-instrumented.h:atomic64_xchg Cyclomatic Complexity 1 include/linux/err.h:ERR_PTR Cyclomatic Complexity 1 include/linux/err.h:PTR_ERR Cyclomatic Complexity 9 arch/x86/include/asm/preempt.h:__preempt_count_add Cyclomatic Complexity 9 arch/x86/include/asm/preempt.h:__preempt_count_sub Cyclomatic Complexity 1 include/linux/spinlock.h:spin_lock_bh Cyclomatic Complexity 1 include/linux/spinlock.h:spin_unlock Cyclomatic Complexity 1 include/linux/spinlock.h:spin_unlock_bh Cyclomatic Complexity 1 include/linux/rcupdate.h:__rcu_read_lock Cyclomatic Complexity 1 include/linux/rcupdate.h:__rcu_read_unlock Cyclomatic Complexity 5 include/linux/rcupdate.h:rcu_read_lock Cyclomatic Complexity 1 include/linux/ktime.h:ktime_to_ns Cyclomatic Complexity 1 include/linux/list_nulls.h:is_a_nulls Cyclomatic Complexity 4 include/linux/slab.h:kmalloc_type Cyclomatic Complexity 84 include/linux/slab.h:kmalloc_index Cyclomatic Complexity 1 include/linux/slab.h:kmalloc_large Cyclomatic Complexity 10 include/linux/slab.h:kmalloc Cyclomatic Complexity 1 include/linux/slab.h:kzalloc Cyclomatic Complexity 1 include/linux/skbuff.h:skb_is_nonlinear Cyclomatic Complexity 1 include/linux/skbuff.h:skb_tail_pointer Cyclomatic Complexity 2 include/linux/skbuff.h:skb_tailroom Cyclomatic Complexity 1 include/net/net_namespace.h:net_eq Cyclomatic Complexity 1 include/net/net_namespace.h:read_pnet Cyclomatic Complexity 5 include/linux/netfilter.h:nf_inet_addr_cmp Cyclomatic Complexity 1 include/net/netlink.h:nlmsg_msg_size Cyclomatic Complexity 1 include/net/netlink.h:nlmsg_total_size Cyclomatic Complexity 1 include/net/netlink.h:nlmsg_data Cyclomatic Complexity 1 include/net/netlink.h:nlmsg_report Cyclomatic Complexity 1 include/net/netlink.h:nlmsg_end Cyclomatic Complexity 1 include/net/netlink.h:nla_data Cyclomatic Complexity 1 include/net/netlink.h:nla_len Cyclomatic Complexity 1 include/net/netlink.h:nla_get_be32 Cyclomatic Complexity 1 include/net/netlink.h:nla_get_u8 Cyclomatic Complexity 1 include/net/netlink.h:nla_get_in_addr Cyclomatic Complexity 1 include/net/netlink.h:nla_nest_end Cyclomatic Complexity 1 include/net/sock.h:sock_net Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack.h:nf_ct_tuplehash_to_ctrack Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack.h:nf_ct_l3num Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack.h:nf_ct_protonum Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack.h:nf_ct_net Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack.h:nf_ct_expires Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack.h:nf_ct_is_expired Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_zones.h:nf_ct_zone Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_zones.h:nf_ct_zone_init Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_extend.h:__nf_ct_ext_exist Cyclomatic Complexity 3 include/net/netfilter/nf_conntrack_extend.h:nf_ct_ext_exist Cyclomatic Complexity 3 include/net/netfilter/nf_conntrack_extend.h:__nf_ct_ext_find Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_ecache.h:nf_ct_ecache_ext_add Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_ecache.h:nf_conntrack_eventmask_report Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_helper.h:nfct_help Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_seqadj.h:nfct_seqadj Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_acct.h:nf_conn_acct_find Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_timestamp.h:nf_conn_tstamp_find Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_timestamp.h:nf_ct_tstamp_ext_add Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_labels.h:nf_ct_labels_ext_add Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_synproxy.h:nfct_synproxy Cyclomatic Complexity 1 include/net/netfilter/nf_conntrack_synproxy.h:nfct_synproxy_ext_add Cyclomatic Complexity 1 include/linux/netfilter/nfnetlink.h:nfnl_msg_type Cyclomatic Complexity 1 net/netfilter/nf_conntrack_netlink.c:ctnetlink_attach_labels Cyclomatic Complexity 1 net/netfilter/nf_conntrack_netlink.c:expect_iter_all Cyclomatic Complexity 1 net/netfilter/nf_conntrack_netlink.c:ctnetlink_net_init Cyclomatic Complexity 1 net/netfilter/nf_conntrack_netlink.c:ctnetlink_net_exit Cyclomatic Complexity 2 net/netfilter/nf_conntrack_netlink.c:ctnetlink_net_exit_batch Cyclomatic Complexity 2 include/asm-generic/bitops-instrumented.h:test_bit vim +/if +516 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 { 517 ctnetlink_dump_timestamp(skb, ct) < 0 || 518 ctnetlink_dump_helpinfo(skb, ct) < 0 || 519 ctnetlink_dump_labels(skb, ct) < 0 || 520 ctnetlink_dump_ct_seq_adj(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