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[3/7] net: stmmac: Check for DMA mapping errors

Message ID 20170223172438.14770-4-thierry.reding@gmail.com
State Superseded
Headers show

Commit Message

Thierry Reding Feb. 23, 2017, 5:24 p.m. UTC
From: Thierry Reding <treding@nvidia.com>

When DMA mapping an SKB fragment, the mapping must be checked for
errors, otherwise the DMA debug code will complain upon unmap.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Mikko Perttunen Feb. 27, 2017, 9:37 a.m. UTC | #1
On 23.02.2017 19:24, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> When DMA mapping an SKB fragment, the mapping must be checked for
> errors, otherwise the DMA debug code will complain upon unmap.
>
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 6b7a5ce19589..d7387919bdb6 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -2072,6 +2072,8 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
>  		des = skb_frag_dma_map(priv->device, frag, 0,
>  				       skb_frag_size(frag),
>  				       DMA_TO_DEVICE);
> +		if (dma_mapping_error(priv->device, des))
> +			goto dma_map_err;

If this map fails, we should also unmap the previously mapped fragments 
and the separate mapping made using dma_map_single.

>
>  		stmmac_tso_allocator(priv, des, skb_frag_size(frag),
>  				     (i == nfrags - 1));
>
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Thierry Reding March 9, 2017, 7:29 p.m. UTC | #2
On Mon, Feb 27, 2017 at 11:37:24AM +0200, Mikko Perttunen wrote:
> On 23.02.2017 19:24, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > When DMA mapping an SKB fragment, the mapping must be checked for
> > errors, otherwise the DMA debug code will complain upon unmap.
> > 
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> >  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > index 6b7a5ce19589..d7387919bdb6 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > @@ -2072,6 +2072,8 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
> >  		des = skb_frag_dma_map(priv->device, frag, 0,
> >  				       skb_frag_size(frag),
> >  				       DMA_TO_DEVICE);
> > +		if (dma_mapping_error(priv->device, des))
> > +			goto dma_map_err;
> 
> If this map fails, we should also unmap the previously mapped fragments and
> the separate mapping made using dma_map_single.

That's already taken care of via the dma_map_err label:

	dev_kfree_skb()
	  consume_skb()
	    __kfree_skb()
	      skb_release_all()
	        skb_release_data()

Thierry
diff mbox

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 6b7a5ce19589..d7387919bdb6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2072,6 +2072,8 @@  static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 		des = skb_frag_dma_map(priv->device, frag, 0,
 				       skb_frag_size(frag),
 				       DMA_TO_DEVICE);
+		if (dma_mapping_error(priv->device, des))
+			goto dma_map_err;
 
 		stmmac_tso_allocator(priv, des, skb_frag_size(frag),
 				     (i == nfrags - 1));