Re: [PATCH] ath10k: fix invalid dma_addr_t token assignment

[Kalle Valo]

Arnd Bergmann <arnd@xxxxxxxxxx> wrote:

> Using a kernel pointer in place of a dma_addr_t token can
> lead to undefined behavior if that makes it into cache
> management functions. The compiler caught one such attempt
> in a cast:
> 
> drivers/net/wireless/ath/ath10k/mac.c: In function 'ath10k_add_interface':
> drivers/net/wireless/ath/ath10k/mac.c:5586:47: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
>  5586 |                         arvif->beacon_paddr = (dma_addr_t)arvif->beacon_buf;
>       |                                               ^
> 
> Looking through how this gets used down the way, I'm fairly
> sure that beacon_paddr is never accessed again for ATH10K_DEV_TYPE_HL
> devices, and if it was accessed, that would be a bug.
> 
> Change the assignment to use a known-invalid address token
> instead, which avoids the warning and makes it easier to catch
> bugs if it does end up getting used.
> 
> Fixes: e263bdab9c0e ("ath10k: high latency fixes for beacon buffer")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>

Patch applied to ath-next branch of ath.git, thanks.

937e79c67740 ath10k: fix invalid dma_addr_t token assignment

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20211014075153.3655910-1-arnd@xxxxxxxxxx/

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