From 81ad054a96bae16e96f600ad74f0a6bee79a83e7 Mon Sep 17 00:00:00 2001
From: Benjamin Poirier <benjamin.poirier@gmail.com>
Date: Fri, 28 Jul 2017 13:25:14 -0700
Subject: [PATCH] tcptop: Filter out negative values in receive probe

When tcp_cleanup_rbuf() is called from tcp_recvmsg(), "copied" may be an
error code, especially -EAGAIN for non-blocking receives.
---
 tools/tcptop.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/tcptop.py b/tools/tcptop.py
index 0f9ead6e..9ca10f62 100755
--- a/tools/tcptop.py
+++ b/tools/tcptop.py
@@ -148,6 +148,9 @@ int kprobe__tcp_cleanup_rbuf(struct pt_regs *ctx, struct sock *sk, int copied)
     u16 dport = 0, family = sk->__sk_common.skc_family;
     u64 *val, zero = 0;
 
+    if (copied <= 0)
+	    return 0;
+
     if (family == AF_INET) {
         struct ipv4_key_t ipv4_key = {.pid = pid};
         ipv4_key.saddr = sk->__sk_common.skc_rcv_saddr;
-- 
2.34.1