path: root/samples/bpf
diff options
authorMagnus Karlsson <magnus.karlsson@intel.com>2020-09-10 10:31:05 +0200
committerAlexei Starovoitov <ast@kernel.org>2020-09-14 18:38:11 -0700
commit5a2a0dd88f0f267ac5953acd81050ae43a82201f (patch)
treeb24ffa24309ba95a3e56b962a90d9fd17226a194 /samples/bpf
parent3131cf66d3033aa40db5b5d72a2673315b61c862 (diff)
samples/bpf: Fix possible deadlock in xdpsock
Fix a possible deadlock in the l2fwd application in xdpsock that can occur when there is no space in the Tx ring. There are two ways to get the kernel to consume entries in the Tx ring: calling sendto() to make it send packets and freeing entries from the completion ring, as the kernel will not send a packet if there is no space for it to add a completion entry in the completion ring. The Tx loop in l2fwd only used to call sendto(). This patches adds cleaning the completion ring in that loop. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1599726666-8431-3-git-send-email-magnus.karlsson@gmail.com
Diffstat (limited to 'samples/bpf')
1 files changed, 1 insertions, 0 deletions
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index b6175cb9a31d..b60bf4ef7cdb 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -1125,6 +1125,7 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
while (ret != rcvd) {
if (ret < 0)
+ complete_tx_l2fwd(xsk, fds);
if (xsk_ring_prod__needs_wakeup(&xsk->tx))
ret = xsk_ring_prod__reserve(&xsk->tx, rcvd, &idx_tx);