From: Kalle Valo <kvalo@codeaurora.org>
To: Arnd Bergmann <arnd@kernel.org>
Cc: QCA ath9k Development <ath9k-devel@qca.qualcomm.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 08/11] ath9k: work around false-positive gcc warning
Date: Mon, 02 Nov 2020 18:26:51 +0200 [thread overview]
Message-ID: <87tuu7ohbo.fsf@codeaurora.org> (raw)
In-Reply-To: <20201026213040.3889546-8-arnd@kernel.org> (Arnd Bergmann's message of "Mon, 26 Oct 2020 22:29:55 +0100")
Arnd Bergmann <arnd@kernel.org> writes:
> From: Arnd Bergmann <arnd@arndb.de>
>
> gcc-10 shows a false-positive warning with CONFIG_KASAN:
>
> drivers/net/wireless/ath/ath9k/dynack.c: In function 'ath_dynack_sample_tx_ts':
> include/linux/etherdevice.h:290:14: warning: writing 4 bytes into a region of size 0 [-Wstringop-overflow=]
> 290 | *(u32 *)dst = *(const u32 *)src;
> | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
>
> Until gcc is fixed, work around this by using memcpy() in place
> of ether_addr_copy(). Hopefully gcc-11 will not have this problem.
>
> Link: https://godbolt.org/z/sab1MK
> Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97490
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/net/wireless/ath/ath9k/dynack.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c
> index fbeb4a739d32..e4eb96b26ca4 100644
> --- a/drivers/net/wireless/ath/ath9k/dynack.c
> +++ b/drivers/net/wireless/ath/ath9k/dynack.c
> @@ -247,8 +247,14 @@ void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
> ridx = ts->ts_rateindex;
>
> da->st_rbf.ts[da->st_rbf.t_rb].tstamp = ts->ts_tstamp;
> +#if defined(CONFIG_KASAN) && (CONFIG_GCC_VERSION >= 100000) && (CONFIG_GCC_VERSION < 110000)
> + /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97490 */
> + memcpy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1, ETH_ALEN);
> + memcpy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2, ETH_ALEN);
> +#else
> ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1);
> ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2);
> +#endif
Isn't there a better way to handle this? I really would not want
checking for GCC versions become a common approach in drivers.
I even think that using memcpy() always is better than the ugly ifdef.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
next prev parent reply other threads:[~2020-11-02 16:27 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 21:29 [PATCH net-next 01/11] atm: horizon: shut up clang null pointer arithmetic warning Arnd Bergmann
2020-10-26 21:29 ` [PATCH net-next 02/11] net: hostap: fix function cast warning Arnd Bergmann
2020-11-07 11:37 ` Kalle Valo
2020-10-26 21:29 ` [PATCH net-next 04/11] wimax: fix duplicate initializer warning Arnd Bergmann
2020-10-27 7:22 ` Johannes Berg
2020-10-27 11:51 ` Arnd Bergmann
2020-10-27 14:51 ` Perez-Gonzalez, Inaky
2020-10-26 21:29 ` [PATCH net-next 05/11] wimax/i2400m/control: fix enum warning Arnd Bergmann
2020-10-26 21:29 ` [PATCH net-next 06/11] rtlwifi: fix -Wpointer-sign warning Arnd Bergmann
2020-10-27 1:29 ` Pkshih
2020-10-26 21:29 ` [PATCH net-next 07/11] rtw88: remove extraneous 'const' qualifier Arnd Bergmann
2020-10-27 1:49 ` Nathan Chancellor
2020-10-26 21:29 ` [PATCH net-next 08/11] ath9k: work around false-positive gcc warning Arnd Bergmann
2020-11-02 16:26 ` Kalle Valo [this message]
2020-11-02 17:59 ` Johannes Berg
2020-11-02 22:29 ` Arnd Bergmann
2020-11-07 11:18 ` Kalle Valo
2020-11-07 11:36 ` Arnd Bergmann
2020-11-10 18:13 ` Kalle Valo
2020-10-26 21:29 ` [PATCH net-next 09/11] ath6kl: fix enum-conversion warning Arnd Bergmann
2020-10-27 6:15 ` Kalle Valo
2020-11-07 8:08 ` Kalle Valo
2020-10-26 21:29 ` [PATCH net-next 10/11] ch_ktls: " Arnd Bergmann
2020-10-26 21:42 ` Andrew Lunn
2020-10-26 21:29 ` [PATCH net-next 11/11] ipv6: fix type mismatch warning Arnd Bergmann
2020-10-27 3:55 ` [PATCH net-next 01/11] atm: horizon: shut up clang null pointer arithmetic warning Xie He
2020-10-27 4:02 ` Xie He
2020-10-27 13:23 ` Arnd Bergmann
2020-10-27 21:46 ` Xie He
2020-10-28 0:42 ` Jakub Kicinski
2020-10-28 8:35 ` Arnd Bergmann
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