From: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> [ Upstream commit 092fde0f863b72b67c4d6dc03844f5658fc00a35 ] Fix a possible hang in xdpsock that can occur when using multiple threads. In this case, one or more of the threads might get stuck in the while-loop in tx_only after the user has signaled the main thread to stop execution. In this case, no more Tx packets will be sent, so a thread might get stuck in the aforementioned while-loop. Fix this by introducing a test inside the while-loop to check if the benchmark has been terminated. If so, return from the function. Fixes: cd9e72b6f210 ("samples/bpf: xdpsock: Add option to specify batch size") Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Link: https://lore.kernel.org/bpf/20201210163407.22066-1-magnus.karlsson@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- samples/bpf/xdpsock_user.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 1149e94ca32fd..33c58de58626c 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -1250,6 +1250,8 @@ static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size) while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) < batch_size) { complete_tx_only(xsk, batch_size); + if (benchmark_done) + return; } for (i = 0; i < batch_size; i++) { -- 2.27.0