bpf: Fix tcp_rwnd_kern.c sample program

The program was returning -1 in some cases which is not allowed
by the verifier any longer.

Fixes: 390ee7e29fc8 ("bpf: enforce return code for cgroup-bpf programs")
Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/samples/bpf/tcp_rwnd_kern.c b/samples/bpf/tcp_rwnd_kern.c
index 3f2a228f81ceb21d4cb48ee9d7fd2075eb4360ff..09ff65b40b31e9ebb23ea0549e24c326bf943900 100644 (file)
--- a/samples/bpf/tcp_rwnd_kern.c
+++ b/samples/bpf/tcp_rwnd_kern.c
@@ -38,8 +38,10 @@ int bpf_rwnd(struct bpf_sock_ops *skops)
         * if neither port numberis 55601
         */
        if (bpf_ntohl(skops->remote_port) !=
-           55601 && skops->local_port != 55601)
-               return -1;
+           55601 && skops->local_port != 55601) {
+               skops->reply = -1;
+               return 1;
+       }
 
        op = (int) skops->op;