From: Eric Dumazet <edumazet@google.com>
Date: Tue, 5 Nov 2019 05:38:43 +0000 (-0800)
Subject: net: prevent load/store tearing on sk->sk_stamp
X-Git-Tag: v4.9.201~28
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4e8e9fd6a3a1c733ee9f0879fa4a3b2589406205;p=platform%2Fkernel%2Flinux-amlogic.git

net: prevent load/store tearing on sk->sk_stamp

[ Upstream commit f75359f3ac855940c5718af10ba089b8977bf339 ]

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: Sasha Levin <sashal@kernel.org>
---

diff --git a/include/net/sock.h b/include/net/sock.h
index 469c012a6d01..d8d14ae8892a 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2142,7 +2142,7 @@ static inline ktime_t sock_read_timestamp(struct sock *sk)
 
 	return kt;
 #else
-	return sk->sk_stamp;
+	return READ_ONCE(sk->sk_stamp);
 #endif
 }
 
@@ -2153,7 +2153,7 @@ static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
 	sk->sk_stamp = kt;
 	write_sequnlock(&sk->sk_stamp_seq);
 #else
-	sk->sk_stamp = kt;
+	WRITE_ONCE(sk->sk_stamp, kt);
 #endif
 }