Re: [PATCH] p54: avoid accessing the data mapped to streaming DMA

[Kalle Valo]

Jia-Ju Bai <baijiaju@xxxxxxxxxxxxxxx> wrote:

> In p54p_tx(), skb->data is mapped to streaming DMA on line 337:
>   mapping = pci_map_single(..., skb->data, ...);
> 
> Then skb->data is accessed on line 349:
>   desc->device_addr = ((struct p54_hdr *)skb->data)->req_id;
> 
> This access may cause data inconsistency between CPU cache and hardware.
> 
> To fix this problem, ((struct p54_hdr *)skb->data)->req_id is stored in
> a local variable before DMA mapping, and then the driver accesses this
> local variable instead of skb->data.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju@xxxxxxxxxxxxxxx>

Can someone review this?

-- 
https://patchwork.kernel.org/patch/11696391/

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