From: Yonghong Song <yhs@xxxxxx>
Date: Thu, 5 Aug 2021 09:53:40 -0700
> On 8/4/21 12:08 AM, Kuniyuki Iwashima wrote:
> > This patch implements the BPF iterator for the UNIX domain socket and
> > exports some functions under GPL for the CONFIG_UNIX=m case.
> >
> > Currently, the batch optimization introduced for the TCP iterator in the
> > commit 04c7820b776f ("bpf: tcp: Bpf iter batching and lock_sock") is not
> > applied. It will require replacing the big lock for the hash table with
> > small locks for each hash list not to block other processes.
> >
> > Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx>
> > ---
> > fs/proc/proc_net.c | 2 +
> > include/linux/btf_ids.h | 3 +-
> > kernel/bpf/bpf_iter.c | 3 ++
> > net/core/filter.c | 1 +
> > net/unix/af_unix.c | 93 +++++++++++++++++++++++++++++++++++++++++
> > 5 files changed, 101 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
> > index 15c2e55d2ed2..887a8102da9f 100644
> > --- a/fs/proc/proc_net.c
> > +++ b/fs/proc/proc_net.c
> > @@ -91,6 +91,7 @@ int bpf_iter_init_seq_net(void *priv_data, struct bpf_iter_aux_info *aux)
> > #endif
> > return 0;
> > }
> > +EXPORT_SYMBOL_GPL(bpf_iter_init_seq_net);
>
> bpf_iter does not support modules for now as it is implemented before
> module btf support. It needs some changes.
> For example, currently bpf_iter only caches/uses the vmlinux btf_id
> and module obj_id and module btf_id is not used.
> One example is ipv6 and bpf_iter is guarded with IS_BUILTIN(CONFIG_IPV6).
>
> So you could (1) add btf_iter support module btf in this patch set, or
> (2). check IS_BUILTIN(CONFIG_UNIX). (2) might be easier and you can have
> a subsequent patch set to add module support for bpf_iter. But it is
> up to you.
I'll add IS_BUILTIN() check in the next spin and give a try to (1).
Thanks for review!
