netdev - Re: [PATCH RFC bpf-next 1/2] bpf: Move the PTR_TO_BTF_ID check to check_reg

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Message-ID: <CACAyw99zWUfZnDsr3bFPatBOdEg75cWh7rSp_M4OQ1tM7mTTyA@mail.gmail.com>
Date:   Mon, 14 Sep 2020 10:29:22 +0100
From:   Lorenz Bauer <lmb@...udflare.com>
To:     Martin KaFai Lau <kafai@...com>
Cc:     bpf <bpf@...r.kernel.org>, Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Kernel Team <kernel-team@...com>,
        Networking <netdev@...r.kernel.org>
Subject: Re: [PATCH RFC bpf-next 1/2] bpf: Move the PTR_TO_BTF_ID check to check_reg_type()

On Sat, 12 Sep 2020 at 05:59, Martin KaFai Lau <kafai@...com> wrote:
>
> check_reg_type() checks whether a reg can be used as an arg of a
> func_proto.  For PTR_TO_BTF_ID, the check is actually not
> completely done until the reg->btf_id is pointing to a
> kernel struct that is acceptable by the func_proto.
>
> Thus, this patch moves the btf_id check into check_reg_type().
> The compatible_reg_types[] usage is localized in check_reg_type()
> now which I found it easier to reason in the next patch.
>
> The "if (!btf_id) verbose(...); " is removed for now since it won't
> happen.  It will be added back in the next patch with new error log
> specific to mis-configured compatible_reg_types[].

This is a nice idea, thanks.

-- 
Lorenz Bauer  |  Systems Engineer
6th Floor, County Hall/The Riverside Building, SE1 7PB, UK

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