[PATCH 5.9 220/757] samples/bpf: Fix to xdpsock to avoid recycling frames

From: Weqaar Janjua weqaar.a.janjua@intel.com

[ Upstream commit b69e56cf765155dcac0037d7d0f162a2afab76c2 ]

The txpush program in the xdpsock sample application is supposed to send out all packets in the umem in a round-robin fashion. The problem is that it only cycled through the first BATCH_SIZE worth of packets. Fixed this so that it cycles through all buffers in the umem as intended.

Fixes: 248c7f9c0e21 ("samples/bpf: convert xdpsock to use libbpf for AF_XDP access") Signed-off-by: Weqaar Janjua weqaar.a.janjua@intel.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Björn Töpel bjorn.topel@intel.com Link: https://lore.kernel.org/bpf/20200828161717.42705-1-weqaar.a.janjua@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- samples/bpf/xdpsock_user.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 19c679456a0e2..c821e98671393 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -1004,7 +1004,7 @@ static void rx_drop_all(void) } }

-static void tx_only(struct xsk_socket_info *xsk, u32 frame_nb, int batch_size) +static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size) { u32 idx; unsigned int i; @@ -1017,14 +1017,14 @@ static void tx_only(struct xsk_socket_info *xsk, u32 frame_nb, int batch_size) for (i = 0; i < batch_size; i++) { struct xdp_desc *tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx + i); - tx_desc->addr = (frame_nb + i) << XSK_UMEM__DEFAULT_FRAME_SHIFT; + tx_desc->addr = (*frame_nb + i) << XSK_UMEM__DEFAULT_FRAME_SHIFT; tx_desc->len = PKT_SIZE; }

xsk_ring_prod__submit(&xsk->tx, batch_size); xsk->outstanding_tx += batch_size; - frame_nb += batch_size; - frame_nb %= NUM_FRAMES; + *frame_nb += batch_size; + *frame_nb %= NUM_FRAMES; complete_tx_only(xsk, batch_size); }

@@ -1080,7 +1080,7 @@ static void tx_only_all(void) }

for (i = 0; i < num_socks; i++) - tx_only(xsks[i], frame_nb[i], batch_size); + tx_only(xsks[i], &frame_nb[i], batch_size);

pkt_cnt += batch_size;