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Date:   Mon, 10 Feb 2020 15:58:12 -0800
From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
To:     KP Singh <kpsingh@chromium.org>
Cc:     linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        Brendan Jackman <jackmanb@google.com>,
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Subject: Re: [PATCH bpf-next v3 03/10] bpf: lsm: Introduce types for eBPF
 based LSM
Message-ID: <20200210235811.pbzvlok6rin7lctd@ast-mbp>
References: <20200123152440.28956-1-kpsingh@chromium.org>
 <20200123152440.28956-4-kpsingh@chromium.org>
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On Thu, Jan 23, 2020 at 07:24:33AM -0800, KP Singh wrote:
> +
> +static const struct bpf_func_proto *get_bpf_func_proto(
> +	enum bpf_func_id func_id, const struct bpf_prog *prog)
> +{
> +	switch (func_id) {
> +	case BPF_FUNC_map_lookup_elem:
> +		return &bpf_map_lookup_elem_proto;
> +	case BPF_FUNC_get_current_pid_tgid:
> +		return &bpf_get_current_pid_tgid_proto;
> +	default:
> +		return NULL;
> +	}
> +}
> +
> +const struct bpf_verifier_ops lsm_verifier_ops = {
> +	.get_func_proto = get_bpf_func_proto,
> +};

Why artificially limit it like this?
It will cause a lot of churn in the future. Like allowing map update and
delete, in addition to lookup, will be an obvious next step.
I think allowing tracing_func_proto() from the start is cleaner.