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Date:   Mon, 28 Sep 2020 23:06:19 -0700
From:   Martin KaFai Lau <kafai@fb.com>
To:     Lorenz Bauer <lmb@cloudflare.com>
CC:     Shuah Khan <shuah@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        <kernel-team@cloudflare.com>, <linux-kselftest@vger.kernel.org>,
        <netdev@vger.kernel.org>, <bpf@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH bpf-next v2 4/4] selftest: bpf: Test copying a sockmap
 and sockhash
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On Mon, Sep 28, 2020 at 10:08:05AM +0100, Lorenz Bauer wrote:

[ ... ]

>  SEC("iter/sockmap")
> -int count_elems(struct bpf_iter__sockmap *ctx)
> +int copy(struct bpf_iter__sockmap *ctx)
>  {
>  	struct sock *sk = ctx->sk;
>  	__u32 tmp, *key = ctx->key;
>  	int ret;
>  
> -	if (key)
> -		elems++;
> +	if (!key)
> +		return 0;
>  
> -	if (sk)
> +	elems++;
> +
> +	/* We need a temporary buffer on the stack, since the verifier doesn't
> +	 * let us use the pointer from the context as an argument to the helper.
Is it something that can be improved later?

others LGTM.