From: Eric Dumazet <edumazet@google.com>
Date: Mon, 4 Nov 2019 21:38:43 -0800
Subject: net: prevent load/store tearing on sk->sk_stamp
Git-commit: f75359f3ac855940c5718af10ba089b8977bf339
Patch-mainline: 5.4-rc7
References: bnc#1151927 5.3.11

Add a couple of READ_ONCE() and WRITE_ONCE() to prevent
load-tearing and store-tearing in sock_read_timestamp()
and sock_write_timestamp()

This might prevent another KCSAN report.

Fixes: 3a0ed3e96197 ("sock: Make sock->sk_stamp thread-safe")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 include/net/sock.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2342,7 +2342,7 @@ static inline ktime_t sock_read_timestam
 
 	return kt;
 #else
-	return sk->sk_stamp;
+	return READ_ONCE(sk->sk_stamp);
 #endif
 }
 
@@ -2353,7 +2353,7 @@ static inline void sock_write_timestamp(
 	sk->sk_stamp = kt;
 	write_sequnlock(&sk->sk_stamp_seq);
 #else
-	sk->sk_stamp = kt;
+	WRITE_ONCE(sk->sk_stamp, kt);
 #endif
 }