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| author | Saeed Mahameed <saeedm@mellanox.com> | 2018-07-15 12:54:39 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-07-16 23:05:25 +0200 |
| commit | 432e629e56432064761be63bcd5e263c0920430d (patch) | |
| tree | 240179174a971852df78f7c74080ab9233b4b1e2 /drivers/net | |
| parent | net/ethernet/freescale/fman: fix cross-build error (diff) | |
| download | linux-432e629e56432064761be63bcd5e263c0920430d.tar.xz linux-432e629e56432064761be63bcd5e263c0920430d.zip | |
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: 34db548bfb95 ("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>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_rx.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 9f54ccbddea7..3360f7b9ee73 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -474,10 +474,10 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv, { const struct mlx4_en_frag_info *frag_info = priv->frag_info; unsigned int truesize = 0; + bool release = true; int nr, frag_size; struct page *page; dma_addr_t dma; - bool release; /* Collect used fragments while replacing them in the HW descriptors */ for (nr = 0;; frags++) { @@ -500,7 +500,11 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv, release = page_count(page) != 1 || page_is_pfmemalloc(page) || page_to_nid(page) != numa_mem_id(); - } else { + } else if (!priv->rx_headroom) { + /* rx_headroom for non XDP setup is always 0. + * When XDP is set, the above condition will + * guarantee page is always released. + */ u32 sz_align = ALIGN(frag_size, SMP_CACHE_BYTES); frags->page_offset += sz_align; |