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From: Kalle Valo <kvalo@codeaurora.org>
To: Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
Cc: chunkeey@googlemail.com, davem@davemloft.net, kuba@kernel.org,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
Subject: Re: p54: avoid accessing the data mapped to streaming DMA
Date: Tue,  1 Sep 2020 09:34:04 +0000 (UTC)	[thread overview]
Message-ID: <20200901093404.47364C433CB@smtp.codeaurora.org> (raw)
In-Reply-To: <20200802132949.26788-1-baijiaju@tsinghua.edu.cn>

Jia-Ju Bai <baijiaju@tsinghua.edu.cn> 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.
> 
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
> Acked-by: Christian Lamparter <chunkeey@gmail.com>

Patch applied to wireless-drivers-next.git, thanks.

478762855b5a p54: avoid accessing the data mapped to streaming DMA

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

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


      parent reply	other threads:[~2020-09-01  9:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-02 13:29 [PATCH] " Jia-Ju Bai
2020-08-18 12:41 ` Kalle Valo
2020-09-01  9:34 ` Kalle Valo [this message]

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