Merge branch 'bpf-af-xdp-unaligned-fixes'

Ciara Loftus says:

====================
This patch set contains some fixes for AF_XDP zero copy in the i40e and
ixgbe drivers as well as a fix for the 'xdpsock' sample application when
running in unaligned mode.

Patches 1 and 2 fix a regression for the i40e and ixgbe drivers which
caused the umem headroom to be added to the xdp handle twice, resulting in
an incorrect value being received by the user for the case where the umem
headroom is non-zero.

Patch 3 fixes an issue with the xdpsock sample application whereby the
start of the tx packet data (offset) was not being set correctly when the
application was being run in unaligned mode.

This patch set has been applied against commit a2c11b03 ("kcm: use
BPF_PROG_RUN")
====================
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

drivers/net/ethernet/intel/i40e/i40e_xsk.c

@@ -192,9 +192,9 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
 {
 	struct xdp_umem *umem = rx_ring->xsk_umem;
 	int err, result = I40E_XDP_PASS;
-	u64 offset = umem->headroom;
 	struct i40e_ring *xdp_ring;
 	struct bpf_prog *xdp_prog;
+	u64 offset;
 	u32 act;
 
 	rcu_read_lock();
@@ -203,7 +203,7 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
 	 */
 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
-	offset += xdp->data - xdp->data_hard_start;
+	offset = xdp->data - xdp->data_hard_start;
 
 	xdp->handle = xsk_umem_adjust_offset(umem, xdp->handle, offset);
 

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

@@ -145,15 +145,15 @@ static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
 {
 	struct xdp_umem *umem = rx_ring->xsk_umem;
 	int err, result = IXGBE_XDP_PASS;
-	u64 offset = umem->headroom;
 	struct bpf_prog *xdp_prog;
 	struct xdp_frame *xdpf;
+	u64 offset;
 	u32 act;
 
 	rcu_read_lock();
 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
-	offset += xdp->data - xdp->data_hard_start;
+	offset = xdp->data - xdp->data_hard_start;
 
 	xdp->handle = xsk_umem_adjust_offset(umem, xdp->handle, offset);
 

samples/bpf/xdpsock_user.c

@@ -685,7 +685,7 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
 	for (i = 0; i < rcvd; i++) {
 		u64 addr = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx)->addr;
 		u32 len = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx++)->len;
-		u64 orig = xsk_umem__extract_addr(addr);
+		u64 orig = addr;
 
 		addr = xsk_umem__add_offset_to_addr(addr);
 		char *pkt = xsk_umem__get_data(xsk->umem->buffer, addr);