When an XDP program uses bpf_xdp_adjust_head() or bpf_xdp_adjust_tail() and then returns XDP_PASS, the driver ignores the updated xdp_buff pointers and builds the skb from hardcoded offsets derived from the original RX descriptor. This means any packet modifications made by the XDP program are silently discarded before the skb reaches the network stack. Fix this by saving the post-XDP data pointer offset and length back into rx_offset and rx_bytes when XDP_PASS is returned, so the subsequent skb_reserve()/skb_put() calls use the actual packet geometry as seen by the XDP program. When no XDP program is loaded the variables retain their original descriptor-derived values and the non-XDP fast path is unaffected. Fixes: 07dd0a7aae7f ("mvpp2: add basic XDP support") Signed-off-by: Til Kaiser --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index f442b874bb59..27d4feebcb59 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3920,7 +3920,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, unsigned int frag_size; dma_addr_t dma_addr; phys_addr_t phys_addr; - int pool, rx_bytes, err, ret; + int pool, rx_bytes, rx_offset, err, ret; struct page *page; void *data; @@ -3933,6 +3933,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, rx_status = mvpp2_rxdesc_status_get(port, rx_desc); rx_bytes = mvpp2_rxdesc_size_get(port, rx_desc); rx_bytes -= MVPP2_MH_SIZE; + rx_offset = MVPP2_MH_SIZE + MVPP2_SKB_HEADROOM; dma_addr = mvpp2_rxdesc_dma_addr_get(port, rx_desc); pool = (rx_status & MVPP2_RXD_BM_POOL_ID_MASK) >> @@ -3998,6 +3999,10 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, continue; } + /* Update offset and length to reflect any XDP adjustments. */ + rx_offset = xdp.data - data; + rx_bytes = xdp.data_end - xdp.data; + metasize = xdp.data - xdp.data_meta; } @@ -4036,7 +4041,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, ps.rx_packets++; ps.rx_bytes += rx_bytes; - skb_reserve(skb, MVPP2_MH_SIZE + MVPP2_SKB_HEADROOM); + skb_reserve(skb, rx_offset); skb_put(skb, rx_bytes); if (metasize) skb_metadata_set(skb, metasize); -- 2.54.0