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Subject: Re: [PATCH][next] brcmfmac: Replace zero-length array with
 flexible-array member
To:     "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
        Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Chi-Hsien Lin <chi-hsien.lin@cypress.com>,
        Wright Feng <wright.feng@cypress.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        "David S. Miller" <davem@davemloft.net>
Cc:     linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com,
        brcm80211-dev-list@cypress.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20200225020804.GA9428@embeddedor>
From:   Arend Van Spriel <arend.vanspriel@broadcom.com>
Message-ID: <170f7087-1f70-941e-9e6c-749eaf3978fe@broadcom.com>
Date:   Fri, 6 Mar 2020 11:26:39 +0100
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On 2/25/2020 3:08 AM, Gustavo A. R. Silva wrote:
> The current codebase makes use of the zero-length array language
> extension to the C90 standard, but the preferred mechanism to declare
> variable-length types such as these ones is a flexible array member[1][2],
> introduced in C99:

[...]

> "Flexible array members have incomplete type, and so the sizeof operator
> may not be applied. As a quirk of the original implementation of
> zero-length arrays, sizeof evaluates to zero."[1]
> 
> This issue was found with the help of Coccinelle.
> 
> [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
> [2] https://github.com/KSPP/linux/issues/21
> [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>   drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.h | 2 +-
>   drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c     | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)