From: Chenguang Zhao <[email protected]>
When AF_XDP ZC receives a multi-buffer frame and the XDP program
returns XDP_PASS, i40e_construct_skb_zc() copies frags into a new
skb. The copy used skb_frag_page() as the memcpy source (page
metadata instead of packet data) and passed a virtual address to
__skb_fill_page_desc_noacc(), which expects a struct page *.
Use skb_frag_address() for the copy, attach frags with
skb_add_rx_frag() so len/data_len/truesize are updated, and on
dev_alloc_page() failure free the skb via the shared out path so
xsk_buff_free() still runs and previously attached pages are
released by kfree_skb.
Fixes: 1c9ba9c14658 ("i40e: xsk: add RX multi-buffer support")
Signed-off-by: Chenguang Zhao <[email protected]>
---
- Fix memcpy source: use skb_frag_address() instead of skb_frag_page(),
which was copying page metadata rather than packet data.
- Fix frag attachment: pass the allocated struct page * to the skb frag
helper instead of the page virtual address.
- Use skb_add_rx_frag() so skb->len, data_len and truesize are updated
when attaching copied frags.
- On mid-loop dev_alloc_page() failure, go through the shared out path
so previously attached pages are released via kfree_skb and
xsk_buff_free() is still called.
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 9f47388eaba5..a4247710c85b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -318,22 +318,19 @@ static struct sk_buff *i40e_construct_skb_zc(struct
i40e_ring *rx_ring,
goto out;
for (int i = 0; i < nr_frags; i++) {
- struct skb_shared_info *skinfo = skb_shinfo(skb);
skb_frag_t *frag = &sinfo->frags[i];
+ unsigned int frag_size = skb_frag_size(frag);
struct page *page;
- void *addr;
page = dev_alloc_page();
if (!page) {
dev_kfree_skb(skb);
- return NULL;
+ skb = NULL;
+ goto out;
}
- addr = page_to_virt(page);
- memcpy(addr, skb_frag_page(frag), skb_frag_size(frag));
-
- __skb_fill_page_desc_noacc(skinfo, skinfo->nr_frags++,
- addr, 0, skb_frag_size(frag));
+ memcpy(page_to_virt(page), skb_frag_address(frag), frag_size);
+ skb_add_rx_frag(skb, i, page, 0, frag_size, PAGE_SIZE);
}
out:
--
2.25.1
