netdev - Re: [PATCH] bpf: use flexible array members, not zero-length

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Message-ID: <20190930085004.GA1698@pc-66.home>
Date:   Mon, 30 Sep 2019 10:50:04 +0200
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Stephen Kitt <steve@....org>
Cc:     Alexei Starovoitov <ast@...nel.org>,
        Martin KaFai Lau <kafai@...com>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        linux-doc@...r.kernel.org, netdev@...r.kernel.org,
        bpf@...r.kernel.org,
        "Gustavo A . R . Silva" <gustavo@...eddedor.com>
Subject: Re: [PATCH] bpf: use flexible array members, not zero-length

On Sat, Sep 28, 2019 at 04:48:14PM +0200, Stephen Kitt wrote:
> This switches zero-length arrays in variable-length structs to C99
> flexible array members. GCC will then ensure that the arrays are
> always the last element in the struct.
> 
> Coccinelle:
> @@
> identifier S, fld;
> type T;
> @@
> 
> struct S {
>   ...
> - T fld[0];
> + T fld[];
>   ...
> };

You did not explain the "why is it needed" part, only what your
change is doing. What [compilation?] issue are you seeing that
you're trying to fix? This sort of information must be present
in a changelog.

> Signed-off-by: Stephen Kitt <steve@....org>

Thanks,
Daniel