From: Lawrence Brakmo <brakmo@fb.com>
Date: Sat, 11 Nov 2017 06:19:51 +0000 (-0800)
Subject: bpf: Fix tcp_rwnd_kern.c sample program
X-Git-Tag: v4.19~2168^2~76^2~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=016e661bb0610a98b1c9ac1250e3269236fabe19;p=platform%2Fkernel%2Flinux-rpi.git

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 3f2a228..09ff65b 100644
--- 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;