Re: [PATCH] mwifiex: avoid null-pointer-subtraction warning

From: Kalle Valo
Date: Tue Sep 28 2021 - 10:43:15 EST


Arnd Bergmann <arnd@xxxxxxxxxx> wrote:

> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> clang complains about some NULL pointer arithmetic in this driver:
>
> drivers/net/wireless/marvell/mwifiex/sta_tx.c:65:59: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
> pad = ((void *)skb->data - (sizeof(*local_tx_pd) + hroom)-
> ^
> drivers/net/wireless/marvell/mwifiex/uap_txrx.c:478:53: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
> pad = ((void *)skb->data - (sizeof(*txpd) + hroom) - NULL) &
>
> Rework that expression to do the same thing using a uintptr_t.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Patch applied to wireless-drivers.git, thanks.

603a1621caa0 mwifiex: avoid null-pointer-subtraction warning

--
https://patchwork.kernel.org/project/linux-wireless/patch/20210927121656.940304-1-arnd@xxxxxxxxxx/

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