[Patch net-next 04/13] udp: introduce tracepoint trace_udp_send_skb()

[Cong Wang <xiyou.wangcong@gmail.com>]

From: Qitao Xu <qitao.xu@bytedance.com>

Tracepoint trace_udp_send_skb() is introduced to trace skb
at the exit of UDP layer on TX side.

Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Qitao Xu <qitao.xu@bytedance.com>
---
 include/trace/events/udp.h | 19 +++++++++++++++++++
 net/ipv4/udp.c             |  4 +++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/include/trace/events/udp.h b/include/trace/events/udp.h
index 336fe272889f..7babc1a11693 100644
--- a/include/trace/events/udp.h
+++ b/include/trace/events/udp.h
@@ -27,6 +27,25 @@ TRACE_EVENT(udp_fail_queue_rcv_skb,
 	TP_printk("rc=%d port=%hu", __entry->rc, __entry->lport)
 );
 
+TRACE_EVENT(udp_send_skb,
+
+	TP_PROTO(const struct sock *sk, const struct sk_buff *skb),
+
+	TP_ARGS(sk, skb),
+
+	TP_STRUCT__entry(
+		__field(const void *, skaddr)
+		__field(const void *, skbaddr)
+	),
+
+	TP_fast_assign(
+		__entry->skaddr = sk;
+		__entry->skbaddr = skb;
+	),
+
+	TP_printk("skaddr=%px, skbaddr=%px", __entry->skaddr, __entry->skbaddr)
+);
+
 #endif /* _TRACE_UDP_H */
 
 /* This part must be outside protection */
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 1a742b710e54..daa618465a1d 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -970,9 +970,11 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
 				      UDP_MIB_SNDBUFERRORS, is_udplite);
 			err = 0;
 		}
-	} else
+	} else {
 		UDP_INC_STATS(sock_net(sk),
 			      UDP_MIB_OUTDATAGRAMS, is_udplite);
+		trace_udp_send_skb(sk, skb);
+	}
 	return err;
 }
 
-- 
2.27.0