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References: <20220914123423.24368-1-liuxin350@huawei.com>
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From:   Hao Luo <haoluo@google.com>
Date:   Wed, 14 Sep 2022 11:15:39 -0700
Message-ID: <CA+khW7hS=c4PSo4coBmw+6VReWNhj+4Bnsr+r+mGsG4tCZ8KnQ@mail.gmail.com>
Subject: Re: [PATCH] libbpf: adjust OPTS_VALID logic, so that it can be used correctly
To:     Xin Liu <liuxin350@huawei.com>
Cc:     ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
        martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
        john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
        jolsa@kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org, yanan@huawei.com,
        wuchangye@huawei.com, xiesongyang@huawei.com, zhudi2@huawei.com,
        kongweibin2@huawei.com
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Hi Xin,

On Wed, Sep 14, 2022 at 5:35 AM Xin Liu <liuxin350@huawei.com> wrote:
>
> We found that function btf_dump__dump_type_data can be called by the user
> as an api, but in this function, the `opts` parameter may be used as a
> null pointer, because OPTS_VALID can't properly prevent opts used as null
> pointers during verification. Therefore, we fix this problem through this
> modification.
>
> This modification has no impact on other places where OPTS_VALID has been
> used.

I think this is a bug of btf_dump__dump_type_data(), not OPTS_VALID.
It seems allowing OPTS_VALID to accept NULL is the intended behavior.

>
[...]
>