From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [PATCH bpf-next] flow_dissector: fix build failure without CONFIG_NET Date: Tue, 18 Sep 2018 14:33:49 -0700 Message-ID: <777de34b-72cd-8c5e-fa02-29a6be28555f@infradead.org> References: <20180918202018.204099-1-willemdebruijn.kernel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: ast@kernel.org, daniel@iogearbox.net, Willem de Bruijn To: Willem de Bruijn , netdev@vger.kernel.org Return-path: Received: from merlin.infradead.org ([205.233.59.134]:59320 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730168AbeISDI2 (ORCPT ); Tue, 18 Sep 2018 23:08:28 -0400 In-Reply-To: <20180918202018.204099-1-willemdebruijn.kernel@gmail.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 9/18/18 1:20 PM, Willem de Bruijn wrote: > From: Willem de Bruijn > > If boolean CONFIG_BPF_SYSCALL is enabled, kernel/bpf/syscall.c will > call flow_dissector functions from net/core/flow_dissector.c. > > This causes this build failure if CONFIG_NET is disabled: > > kernel/bpf/syscall.o: In function `__x64_sys_bpf': > syscall.c:(.text+0x3278): undefined reference to > `skb_flow_dissector_bpf_prog_attach' > syscall.c:(.text+0x3310): undefined reference to > `skb_flow_dissector_bpf_prog_detach' > kernel/bpf/syscall.o:(.rodata+0x3f0): undefined reference to > `flow_dissector_prog_ops' > kernel/bpf/verifier.o:(.rodata+0x250): undefined reference to > `flow_dissector_verifier_ops' > > Analogous to other optional BPF program types in syscall.c, add stubs > if the relevant functions are not compiled and move the BPF_PROG_TYPE > definition in the #ifdef CONFIG_NET block. > > Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") > Reported-by: Randy Dunlap > Signed-off-by: Willem de Bruijn Works for me. Thanks. Acked-by: Randy Dunlap # build-tested > --- > include/linux/bpf_types.h | 2 +- > include/linux/skbuff.h | 13 +++++++++++++ > 2 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h > index 22083712dd18..c9bd6fb765b0 100644 > --- a/include/linux/bpf_types.h > +++ b/include/linux/bpf_types.h > @@ -16,6 +16,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_SEG6LOCAL, lwt_seg6local) > BPF_PROG_TYPE(BPF_PROG_TYPE_SOCK_OPS, sock_ops) > BPF_PROG_TYPE(BPF_PROG_TYPE_SK_SKB, sk_skb) > BPF_PROG_TYPE(BPF_PROG_TYPE_SK_MSG, sk_msg) > +BPF_PROG_TYPE(BPF_PROG_TYPE_FLOW_DISSECTOR, flow_dissector) > #endif > #ifdef CONFIG_BPF_EVENTS > BPF_PROG_TYPE(BPF_PROG_TYPE_KPROBE, kprobe) > @@ -32,7 +33,6 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_LIRC_MODE2, lirc_mode2) > #ifdef CONFIG_INET > BPF_PROG_TYPE(BPF_PROG_TYPE_SK_REUSEPORT, sk_reuseport) > #endif > -BPF_PROG_TYPE(BPF_PROG_TYPE_FLOW_DISSECTOR, flow_dissector) > > BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops) > BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops) > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index ce0e863f02a2..76be85ea392a 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -1194,10 +1194,23 @@ void skb_flow_dissector_init(struct flow_dissector *flow_dissector, > const struct flow_dissector_key *key, > unsigned int key_count); > > +#ifdef CONFIG_NET > int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, > struct bpf_prog *prog); > > int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr); > +#else > +static inline int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, > + struct bpf_prog *prog) > +{ > + return -EOPNOTSUPP; > +} > + > +static inline int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr) > +{ > + return -EOPNOTSUPP; > +} > +#endif > > bool __skb_flow_dissect(const struct sk_buff *skb, > struct flow_dissector *flow_dissector, > -- ~Randy