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Subject: Re: wifi: rtw89: avoid stringop-overflow warning
From: Kalle Valo <kvalo@kernel.org>
In-Reply-To: <20231204073020.1105416-1-arnd@kernel.org>
References: <20231204073020.1105416-1-arnd@kernel.org>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Ping-Ke Shih <pkshih@realtek.com>,
 "Gustavo A. R. Silva" <gustavoars@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
 Ching-Te Ku <ku920601@realtek.com>, linux-wireless@vger.kernel.org,
 linux-kernel@vger.kernel.org
User-Agent: pwcli/0.1.1-git (https://github.com/kvalo/pwcli/) Python/3.11.2
Message-ID: <170239387004.306086.15470071247075562655.kvalo@kernel.org>
Date: Tue, 12 Dec 2023 15:11:11 +0000 (UTC)

Arnd Bergmann <arnd@kernel.org> wrote:

> From: Arnd Bergmann <arnd@arndb.de>
> 
> After -Wstringop-overflow got enabled, the rtw89 driver produced
> two odd warnings with gcc-13:
> 
> drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_scan_start':
> drivers/net/wireless/realtek/rtw89/coex.c:5362:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
>  5362 |                 wl->dbcc_info.scan_band[phy_idx] = band;
>       |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
> In file included from drivers/net/wireless/realtek/rtw89/coex.h:8,
>                  from drivers/net/wireless/realtek/rtw89/coex.c:5:
> drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
>  1441 |         u8 scan_band[RTW89_PHY_MAX]; /* scan band in  each phy */
>       |            ^~~~~~~~~
> drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_switch_band':
> drivers/net/wireless/realtek/rtw89/coex.c:5406:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
>  5406 |                 wl->dbcc_info.scan_band[phy_idx] = band;
>       |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
> drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
>  1441 |         u8 scan_band[RTW89_PHY_MAX]; /* scan band in  each phy */
>       |            ^~~~~~~~~
> 
> I don't know what happened here, but adding an explicit range check
> shuts up the output.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Patch applied to wireless-next.git, thanks.

595b1280e2c9 wifi: rtw89: avoid stringop-overflow warning

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20231204073020.1105416-1-arnd@kernel.org/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches