From: Jiri Olsa <jolsa@redhat.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: "Toke Høiland-Jørgensen" <toke@redhat.com>,
"Jiri Olsa" <jolsa@kernel.org>,
"Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Andrii Nakryiko" <andriin@fb.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
"Martin KaFai Lau" <kafai@fb.com>,
"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
"John Fastabend" <john.fastabend@gmail.com>,
"KP Singh" <kpsingh@chromium.org>
Subject: Re: [RFC PATCH bpf-next 1/4] bpf: Allow trampoline re-attach
Date: Mon, 5 Apr 2021 16:08:17 +0200 [thread overview]
Message-ID: <YGsZ0VGMk/hBfr2y@krava> (raw)
In-Reply-To: <20210403182155.upi6267fh3gsdvrq@ast-mbp>
On Sat, Apr 03, 2021 at 11:21:55AM -0700, Alexei Starovoitov wrote:
> On Sat, Apr 03, 2021 at 01:24:12PM +0200, Toke Høiland-Jørgensen wrote:
> > > if (!prog->aux->dst_trampoline && !tgt_prog) {
> > > - err = -ENOENT;
> > > - goto out_unlock;
> > > + /*
> > > + * Allow re-attach for tracing programs, if it's currently
> > > + * linked, bpf_trampoline_link_prog will fail.
> > > + */
> > > + if (prog->type != BPF_PROG_TYPE_TRACING) {
> > > + err = -ENOENT;
> > > + goto out_unlock;
> > > + }
> > > + if (!prog->aux->attach_btf) {
> > > + err = -EINVAL;
> > > + goto out_unlock;
> > > + }
> >
> > I'm wondering about the two different return codes here. Under what
> > circumstances will aux->attach_btf be NULL, and why is that not an
> > ENOENT error? :)
>
> The feature makes sense to me as well.
> I don't quite see how it would get here with attach_btf == NULL.
> Maybe WARN_ON then?
right, that should be always there
> Also if we're allowing re-attach this way why exclude PROG_EXT and LSM?
>
I was enabling just what I needed for the test, which is so far
the only use case.. I'll see if I can enable that for all of them
jirka
next prev parent reply other threads:[~2021-04-05 14:08 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-28 11:26 [RFC PATCH bpf-next 0/4] bpf: Tracing programs re-attach Jiri Olsa
2021-03-28 11:26 ` [RFC PATCH bpf-next 1/4] bpf: Allow trampoline re-attach Jiri Olsa
2021-03-30 1:18 ` Song Liu
2021-04-03 11:24 ` Toke Høiland-Jørgensen
2021-04-03 18:21 ` Alexei Starovoitov
2021-04-05 14:08 ` Jiri Olsa [this message]
2021-04-05 14:15 ` Toke Høiland-Jørgensen
2021-04-05 21:58 ` Jiri Olsa
2021-04-05 14:06 ` Jiri Olsa
2021-03-28 11:26 ` [RFC PATCH bpf-next 2/4] selftests/bpf: Add re-attach test to fentry_test Jiri Olsa
2021-03-30 1:23 ` Song Liu
2021-03-30 20:02 ` Jiri Olsa
2021-03-28 11:26 ` [RFC PATCH bpf-next 3/4] selftests/bpf: Add re-attach test to fexit_test Jiri Olsa
2021-03-28 11:26 ` [RFC PATCH bpf-next 4/4] selftests/bpf: Test that module can't be unloaded with attached trampoline Jiri Olsa
2021-03-30 6:12 ` Song Liu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YGsZ0VGMk/hBfr2y@krava \
--to=jolsa@redhat.com \
--cc=alexei.starovoitov@gmail.com \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kafai@fb.com \
--cc=kpsingh@chromium.org \
--cc=netdev@vger.kernel.org \
--cc=songliubraving@fb.com \
--cc=toke@redhat.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).