Re: [PATCH][next] rtlwifi: Replace fake flex-array with flex-array member

From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Ping-Ke Shih <pkshih@realtek.com>, Kalle Valo <kvalo@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH][next] rtlwifi: Replace fake flex-array with flex-array member
Date: Thu, 30 Mar 2023 14:04:42 -0600	[thread overview]
Message-ID: <a3bfa2dd-cb4c-876e-b16a-e9cec230108f@embeddedor.com> (raw)
In-Reply-To: <ZBz4x+MWoI/f65o1@work>

Hi all,

Friendly ping: who can take this, please? :)

Thanks
--
Gustavo

On 3/23/23 19:11, Gustavo A. R. Silva wrote:
> Zero-length arrays as fake flexible arrays are deprecated and we are
> moving towards adopting C99 flexible-array members instead.
> 
> Address the following warning found with GCC-13 and
> -fstrict-flex-arrays=3 enabled:
> In function ‘fortify_memset_chk’,
>      inlined from ‘rtl_usb_probe’ at drivers/net/wireless/realtek/rtlwifi/usb.c:1044:2:
> ./include/linux/fortify-string.h:430:25: warning: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
>    430 |                         __write_overflow_field(p_size_field, size);
>        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
> routines on memcpy() and help us make progress towards globally
> enabling -fstrict-flex-arrays=3 [1].
> 
> Link: https://github.com/KSPP/linux/issues/21
> Link: https://github.com/KSPP/linux/issues/277
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>   drivers/net/wireless/realtek/rtlwifi/wifi.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtlwifi/wifi.h b/drivers/net/wireless/realtek/rtlwifi/wifi.h
> index 31f9e9e5c680..082af216760f 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/wifi.h
> +++ b/drivers/net/wireless/realtek/rtlwifi/wifi.h
> @@ -2831,7 +2831,7 @@ struct rtl_priv {
>   	 * beyond  this structure like:
>   	 * rtl_pci_priv or rtl_usb_priv
>   	 */
> -	u8 priv[0] __aligned(sizeof(void *));
> +	u8 priv[] __aligned(sizeof(void *));
>   };
>   
>   #define rtl_priv(hw)		(((struct rtl_priv *)(hw)->priv))