diff options
| author | Jakub Kicinski | 2016-04-16 11:25:53 +0100 |
|---|---|---|
| committer | David S. Miller | 2016-04-16 22:34:40 -0400 |
| commit | 180012dc05e565260a25696767c8f5b2df5fc50e (patch) | |
| tree | 89bbc49d2998219b78575cb17f818705b89bacd2 /drivers | |
| parent | 2db221cd444bf356243c57b653b6bf84c3491806 (diff) | |
nfp: remove buggy RX buffer length validation
Meaning of data_len and meta_len RX WB descriptor fields is
slightly confusing. Add a comment with a diagram clarifying
the layout. Also remove the buffer length validation:
(a) it's imprecise for static rx-offsets; (b) if firmware
is buggy enough to DMA past the end of the buffer
WARN_ON_ONCE() doesn't seem like a strong enough response.
skb_put() will do the checking for us anyway.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index 0bdff390c958..5235e86eb684 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -1298,23 +1298,25 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) nfp_net_rx_give_one(rx_ring, new_skb, new_dma_addr); + /* < meta_len > + * <-- [rx_offset] --> + * --------------------------------------------------------- + * | [XX] | metadata | packet | XXXX | + * --------------------------------------------------------- + * <---------------- data_len ---------------> + * + * The rx_offset is fixed for all packets, the meta_len can vary + * on a packet by packet basis. If rx_offset is set to zero + * (_RX_OFFSET_DYNAMIC) metadata starts at the beginning of the + * buffer and is immediately followed by the packet (no [XX]). + */ meta_len = rxd->rxd.meta_len_dd & PCIE_DESC_RX_META_LEN_MASK; data_len = le16_to_cpu(rxd->rxd.data_len); - if (WARN_ON_ONCE(data_len > nn->fl_bufsz)) { - dev_kfree_skb_any(skb); - continue; - } - - if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC) { - /* The packet data starts after the metadata */ + if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC) skb_reserve(skb, meta_len); - } else { - /* The packet data starts at a fixed offset */ + else skb_reserve(skb, nn->rx_offset); - } - - /* Adjust the SKB for the dynamic meta data pre-pended */ skb_put(skb, data_len - meta_len); nfp_net_set_hash(nn->netdev, skb, rxd); |