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

[Thierry Reding]

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 
> > 
> > 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 
> > ---
> >  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


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

[Mikko Perttunen]

On 23.02.2017 19:24, Thierry Reding wrote:

From: Thierry Reding 

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 
---
 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));