linux-sg2042/drivers/net/ethernet/mellanox
Saeed Mahameed 432e629e56 net/mlx4_en: Don't reuse RX page when XDP is set
When a new rx packet arrives, the rx path will decide whether to reuse
the remainder of the page or not according to one of the below conditions:
1. frag_info->frag_stride == PAGE_SIZE / 2
2. frags->page_offset + frag_info->frag_size > PAGE_SIZE;

The first condition is no met for when XDP is set.
For XDP, page_offset is always set to priv->rx_headroom which is
XDP_PACKET_HEADROOM and frag_info->frag_size is around mtu size + some
padding, still the 2nd release condition will hold since
XDP_PACKET_HEADROOM + 1536 < PAGE_SIZE, as a result the page will not
be released and will be _wrongly_ reused for next free rx descriptor.

In XDP there is an assumption to have a page per packet and reuse can
break such assumption and might cause packet data corruptions.

Fix this by adding an extra condition (!priv->rx_headroom) to the 2nd
case to avoid page reuse when XDP is set, since rx_headroom is set to 0
for non XDP setup and set to XDP_PACKET_HEADROOM for XDP setup.

No additional cache line is required for the new condition.

Fixes: 34db548bfb ("mlx4: add page recycling in receive path")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Suggested-by: Martin KaFai Lau <kafai@fb.com>
CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16 14:05:25 -07:00
..
mlx4 net/mlx4_en: Don't reuse RX page when XDP is set 2018-07-16 14:05:25 -07:00
mlx5/core net/mlx5: Fix command interface race in polling mode 2018-06-26 15:26:34 -07:00
mlxfw net/mlxfw: Properly handle dependancy with non-loadable mlx5 2017-07-03 02:32:25 -07:00
mlxsw net/ipv6: Revert attempt to simplify route replace and append 2018-07-04 15:22:13 +09:00
Kconfig Change Kconfig description 2017-08-14 11:18:16 -07:00
Makefile Add the mlxfw module for Mellanox firmware flash process 2017-05-25 17:46:17 -04:00