[PATCH] tcp: Add skb addr and sock addr to arguments of tracepoint tcp_probe.

[fuyuanli]

It is useful to expose skb addr and sock addr to user in tracepoint
tcp_probe, so that we can get more information while monitoring
receiving of tcp data, by ebpf or other ways.

For example, we need to identify a packet by seq and end_seq when
calculate transmit latency between lay 2 and lay 4 by ebpf, but which is
not available in tcp_probe, so we can only use kprobe hooking
tcp_rcv_esatblised to get them. But we can use tcp_probe directly if skb
addr and sock addr are available, which is more efficient.

Signed-off-by: fuyuanli <fuyuanli@xxxxxxxxxxxxxx>
---
 include/trace/events/tcp.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index 7b1ddffa3dfc..096c15f64b92 100644
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h
@@ -258,6 +258,8 @@ TRACE_EVENT(tcp_probe,
 		__field(__u32, srtt)
 		__field(__u32, rcv_wnd)
 		__field(__u64, sock_cookie)
+		__field(const void *, skbaddr)
+		__field(const void *, skaddr)
 	),
 
 	TP_fast_assign(
@@ -285,6 +287,9 @@ TRACE_EVENT(tcp_probe,
 		__entry->ssthresh = tcp_current_ssthresh(sk);
 		__entry->srtt = tp->srtt_us >> 3;
 		__entry->sock_cookie = sock_gen_cookie(sk);
+
+		__entry->skbaddr = skb;
+		__entry->skaddr = sk;
 	),
 
 	TP_printk("family=%s src=%pISpc dest=%pISpc mark=%#x data_len=%d snd_nxt=%#x snd_una=%#x snd_cwnd=%u ssthresh=%u snd_wnd=%u srtt=%u rcv_wnd=%u sock_cookie=%llx",
-- 
2.17.1