From:   Jonathan Corbet <corbet@lwn.net>
To:     Daniel Borkmann <daniel@iogearbox.net>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        David Vernet <void@manifault.com>
Cc:     bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org,
        martin.lau@linux.dev, song@kernel.org, yhs@meta.com,
        john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
        haoluo@google.com, jolsa@kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@meta.com, memxor@gmail.com
Subject: Re: [PATCH bpf-next v2 3/3] bpf: Use BPF_KFUNC macro at all kfunc
 definitions
In-Reply-To: <ebff2166-8a70-af62-b859-6b5c6b008b36@iogearbox.net>
References: <20230123171506.71995-1-void@manifault.com>
 <20230123171506.71995-4-void@manifault.com>
 <20230123183305.2mgoxgw4ca3sfk24@macbook-pro-6.dhcp.thefacebook.com>
 <Y87We/92xiv5/+g+@maniforge.lan>
 <20230123185434.ybfhrmbootcnjuoj@macbook-pro-6.dhcp.thefacebook.com>
 <ebff2166-8a70-af62-b859-6b5c6b008b36@iogearbox.net>
Date:   Mon, 23 Jan 2023 14:00:17 -0700
Message-ID: <87o7qphspq.fsf@meer.lwn.net>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Daniel Borkmann <daniel@iogearbox.net> writes:

> Did you look into making this similar to the EXPORT_SYMBOL() infra? If possible
> that would look much more natural to developers, e.g. :
>
> struct nf_conn *
> bpf_skb_ct_lookup(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
>   		  u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz)
> {
> 	[...]
> }
>
> EXPORT_BPF_KFUNC(bpf_skb_ct_lookup);

That was my question too; it's a similar functionality that would be
nice to express in a similar way.  Even better, if possible, might be to
fold it into BTF_ID_FLAGS, which I might then rename to EXPORT_KFUNC()
or some such ... :)

Thanks,

jon