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From:   Florent Revest <revest@chromium.org>
Date:   Wed, 26 May 2021 18:37:09 +0200
Message-ID: <CABRcYmL3t=KkSai4RYPp7vH3tmS+FoVqxGYZ3rh=BReRwFouGg@mail.gmail.com>
Subject: Re: [PATCH bpf v2] libbpf: Move BPF_SEQ_PRINTF and BPF_SNPRINTF to bpf_helpers.h
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     Daniel Borkmann <daniel@iogearbox.net>, bpf <bpf@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Andrii Nakryiko <andrii@kernel.org>,
        KP Singh <kpsingh@kernel.org>,
        Brendan Jackman <jackmanb@google.com>,
        open list <linux-kernel@vger.kernel.org>
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On Wed, May 26, 2021 at 6:35 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Wed, May 26, 2021 at 8:01 AM Florent Revest <revest@chromium.org> wrote:
> >
> > On Wed, May 26, 2021 at 8:35 AM Daniel Borkmann <daniel@iogearbox.net> wrote:
> > >
> > > On 5/25/21 10:18 PM, Florent Revest wrote:
> > > > These macros are convenient wrappers around the bpf_seq_printf and
> > > > bpf_snprintf helpers. They are currently provided by bpf_tracing.h which
> > > > targets low level tracing primitives. bpf_helpers.h is a better fit.
> > > >
> > > > The __bpf_narg and __bpf_apply macros are needed in both files so
> > > > provided twice and guarded by ifndefs.
> > > >
> > > > Reported-by: Andrii Nakryiko <andrii@kernel.org>
> > > > Signed-off-by: Florent Revest <revest@chromium.org>
> > >
> > > Given v1/v2 both target bpf tree in the subject, do you really mean bpf or
> > > rather bpf-next?
> >
> > I don't have a preference, it's up to you :)
> >
> > On one hand, I see no urgency in fixing this: BPF_SEQ_PRINTF has been
> > in bpf_tracing.h for a while already so it can wait for another kernel
> > release. Applying this to bpf-next would do.
> > On the other hand, BPF_SNPRINTF hasn't made it to a kernel release yet
> > so we still have a chance to do it right before users start including
> > bpf_tracing.h and we'd break them in the next release. That's why I
> > tagged it as bpf.
> >
> > The patch applies cleanly on both trees so if you prefer landing it in
> > bpf-next it's fine by me.
>
> I think it should go through bpf-next. It's not really a bug fix. And
> we are not going to break anyone with this move. And libbpf 0.4 is
> officially released without this change anyway. So, bpf-next.

Sounds good, I'll send a v3 tagged with bpf-next ;)