Commit 88eb0ee1 authored May 14, 2020 by Jesper Dangaard Brouer Committed by Alexei Starovoitov May 14, 2020

ixgbe: Fix XDP redirect on archs with PAGE_SIZE above 4K

The ixgbe driver have another memory model when compiled on archs with
PAGE_SIZE above 4096 bytes. In this mode it doesn't split the page in
two halves, but instead increment rx_buffer->page_offset by truesize of
packet (which include headroom and tailroom for skb_shared_info).

This is done correctly in ixgbe_build_skb(), but in ixgbe_rx_buffer_flip
which is currently only called on XDP_TX and XDP_REDIRECT, it forgets
to add the tailroom for skb_shared_info. This breaks XDP_REDIRECT, for
veth and cpumap. Fix by adding size of skb_shared_info tailroom.

Maintainers notice: This fix have been queued to Jeff.

Fixes: 64530739 ("ixgbe: add initial support for xdp redirect")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Link: https://lore.kernel.org/bpf/158945344946.97035.17031588499266605743.stgit@firesoul

parent 9ce6146e

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2254,7 +2254,8 @@ static void ixgbe_rx_buffer_flip(struct ixgbe_ring *rx_ring,
		rx_buffer->page_offset ^= truesize;
		#else
		unsigned int truesize = ring_uses_build_skb(rx_ring) ?
		SKB_DATA_ALIGN(IXGBE_SKB_PAD + size) :
		SKB_DATA_ALIGN(IXGBE_SKB_PAD + size) +
		SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
		SKB_DATA_ALIGN(size);

		rx_buffer->page_offset += truesize;

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