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From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@kernel.org>
To:     Zhengchao Shao <shaozhengchao@huawei.com>, bpf@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net,
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        andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
        kpsingh@kernel.org
Cc:     weiyongjun1@huawei.com, shaozhengchao@huawei.com,
        yuehaibing@huawei.com
Subject: Re: [PATCH bpf-next] samples/bpf: check detach prog exist or not in
 xdp_fwd
In-Reply-To: <20220509005105.271089-1-shaozhengchao@huawei.com>
References: <20220509005105.271089-1-shaozhengchao@huawei.com>
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Date:   Mon, 09 May 2022 11:46:20 +0200
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Zhengchao Shao <shaozhengchao@huawei.com> writes:

> Before detach the prog, we should check detach prog exist or not.

If we're adding such a check we should also check that it's the *right*
program. I.e., query the ID for the program name and check that it
matches what the program attached, then obtain an fd and pass that as
XDP_EXPECTED_FD on detach to make sure it wasn't swapped out in the
meantime...

-Toke