target/linux/layerscape/patches-5.4/701-net-0046-sdk_dpaa-update-buffer-recycling-conditions.patch

   1 From b95f457bb7ba38f03a71b474e35f53670322f0db Mon Sep 17 00:00:00 2001
   2 From: Camelia Groza <camelia.groza@nxp.com>
   3 Date: Mon, 15 Jan 2018 17:41:01 +0200
   4 Subject: [PATCH] sdk_dpaa: update buffer recycling conditions
   5
   6 Guarantee there is enough space inside the skb's headroom to store the
   7 skb back-pointer before recycling the buffer. The back-pointer is stored
   8 right before the buffer's start.
   9
  10 Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
  11 ---
  12  drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 8 +++++++-
  13  1 file changed, 7 insertions(+), 1 deletion(-)
  14
  15 --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  16 +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  17 @@ -350,7 +350,13 @@ bool dpa_buf_is_recyclable(struct sk_buf
  18         /* left align to the nearest cacheline */
  19         new = (unsigned char *)((unsigned long)new & ~(SMP_CACHE_BYTES - 1));
  20
  21 -       if (likely(new >= skb->head &&
  22 +       /* Make sure there is enough space to store the skb back-pointer in
  23 +        * the headroom, right before the start of the buffer.
  24 +        *
  25 +        * Guarantee that both maximum size and maximum data offsets aren't
  26 +        * crossed.
  27 +        */
  28 +       if (likely(new >= (skb->head + sizeof(void *)) &&
  29                    new >= (skb->data - DPA_MAX_FD_OFFSET) &&
  30                    skb_end_pointer(skb) - new <= DPA_RECYCLE_MAX_SIZE)) {
  31                 *new_buf_start = new;