* [PATCH] net: ethernet: mtk-star-emac: fix wrong unmap in RX handling
@ 2021-03-02 3:33 Biao Huang
2021-03-02 8:42 ` Bartosz Golaszewski
0 siblings, 1 reply; 2+ messages in thread
From: Biao Huang @ 2021-03-02 3:33 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Felix Fietkau, John Crispin, Sean Wang, Mark Lee,
David S . Miller, Jakub Kicinski, Matthias Brugger, netdev,
linux-arm-kernel, linux-mediatek, linux-kernel, biao.huang,
srv_heupstream
mtk_star_dma_unmap_rx() should unmap the dma_addr of old skb rather than
that of new skb.
Assign new_dma_addr to desc_data.dma_addr after all handling of old skb
ends to avoid unexpected receive side error.
Fixes: f96e9641e92b ("net: ethernet: mtk-star-emac: fix error path in RX handling")
Signed-off-by: Biao Huang <biao.huang@mediatek.com>
---
drivers/net/ethernet/mediatek/mtk_star_emac.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/mediatek/mtk_star_emac.c b/drivers/net/ethernet/mediatek/mtk_star_emac.c
index a8641a407c06..96d2891f1675 100644
--- a/drivers/net/ethernet/mediatek/mtk_star_emac.c
+++ b/drivers/net/ethernet/mediatek/mtk_star_emac.c
@@ -1225,8 +1225,6 @@ static int mtk_star_receive_packet(struct mtk_star_priv *priv)
goto push_new_skb;
}
- desc_data.dma_addr = new_dma_addr;
-
/* We can't fail anymore at this point: it's safe to unmap the skb. */
mtk_star_dma_unmap_rx(priv, &desc_data);
@@ -1236,6 +1234,9 @@ static int mtk_star_receive_packet(struct mtk_star_priv *priv)
desc_data.skb->dev = ndev;
netif_receive_skb(desc_data.skb);
+ /* update dma_addr for new skb */
+ desc_data.dma_addr = new_dma_addr;
+
push_new_skb:
desc_data.len = skb_tailroom(new_skb);
desc_data.skb = new_skb;
--
2.18.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] net: ethernet: mtk-star-emac: fix wrong unmap in RX handling
2021-03-02 3:33 [PATCH] net: ethernet: mtk-star-emac: fix wrong unmap in RX handling Biao Huang
@ 2021-03-02 8:42 ` Bartosz Golaszewski
0 siblings, 0 replies; 2+ messages in thread
From: Bartosz Golaszewski @ 2021-03-02 8:42 UTC (permalink / raw)
To: Biao Huang
Cc: Felix Fietkau, John Crispin, Sean Wang, Mark Lee,
David S . Miller, Jakub Kicinski, Matthias Brugger, netdev,
arm-soc, moderated list:ARM/Mediatek SoC...,
LKML, srv_heupstream
On Tue, Mar 2, 2021 at 4:33 AM Biao Huang <biao.huang@mediatek.com> wrote:
>
> mtk_star_dma_unmap_rx() should unmap the dma_addr of old skb rather than
> that of new skb.
> Assign new_dma_addr to desc_data.dma_addr after all handling of old skb
> ends to avoid unexpected receive side error.
>
> Fixes: f96e9641e92b ("net: ethernet: mtk-star-emac: fix error path in RX handling")
> Signed-off-by: Biao Huang <biao.huang@mediatek.com>
> ---
> drivers/net/ethernet/mediatek/mtk_star_emac.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_star_emac.c b/drivers/net/ethernet/mediatek/mtk_star_emac.c
> index a8641a407c06..96d2891f1675 100644
> --- a/drivers/net/ethernet/mediatek/mtk_star_emac.c
> +++ b/drivers/net/ethernet/mediatek/mtk_star_emac.c
> @@ -1225,8 +1225,6 @@ static int mtk_star_receive_packet(struct mtk_star_priv *priv)
> goto push_new_skb;
> }
>
> - desc_data.dma_addr = new_dma_addr;
> -
> /* We can't fail anymore at this point: it's safe to unmap the skb. */
> mtk_star_dma_unmap_rx(priv, &desc_data);
>
> @@ -1236,6 +1234,9 @@ static int mtk_star_receive_packet(struct mtk_star_priv *priv)
> desc_data.skb->dev = ndev;
> netif_receive_skb(desc_data.skb);
>
> + /* update dma_addr for new skb */
> + desc_data.dma_addr = new_dma_addr;
> +
> push_new_skb:
> desc_data.len = skb_tailroom(new_skb);
> desc_data.skb = new_skb;
> --
> 2.18.0
>
Thanks for spotting that. Maybe also update the commit so that it
says: "it's safe to unmap the old skb"? Would make the thing clearer
IMO.
In any case:
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Bartosz
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