While working on a simplified test for [0] it occurred to me that the following looks fishy: data = xsk_umem__get_data(xsk->umem_area, rx_desc->addr); data_meta = data - sizeof(my metadata); Since the data points to umem frame at addr X, data_mem points to the end of umem frame X-1. I don't think it's by design? 0: https://lore.kernel.org/bpf/20221028181431.05173968@xxxxxxxxxx/T/#t Cc: Björn Töpel <bjorn@xxxxxxxxxx> Cc: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> Cc: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx> Cc: Jonathan Lemon <jonathan.lemon@xxxxxxxxx> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx> --- net/xdp/xsk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 9f0561b67c12..0547fe37ba7e 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -163,7 +163,7 @@ static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len) } else { from_buf = from->data_meta; metalen = from->data - from->data_meta; - to_buf = to->data - metalen; + to_buf = to->data; } memcpy(to_buf, from_buf, len + metalen); -- 2.38.1.431.g37b22c650d-goog
